The guidelines of the international hernia societies recommend posterior repair in laparo-endoscopic technique for recurrent inguinal hernia after open anterior mesh repair and, conversely, open anterior repair for recurrence after laparo-endoscopic primary repair. Even when these guidelines are followed, already 1 year after repair a re-recurrence rate of 1–2% must be expected, with that rate rising further in the subsequent years. Accordingly, increasingly more patients with re-recurrence after anterior and posterior mesh implantation must be treated, which constitutes a problem that to date has been investigated in only very few studies. Hence, there are no well-founded recommendations. This paper now presents a number of case reports aimed at identifying the role of explorative laparoscopy as decision tool for re-recurrent inguinal hernia treatment.Based on three case reports the role of explorative laparoscopy as decision tool for re-recurrent inguinal hernia treatment is presented below.In all the three cases described explorative laparoscopy played a key role as decision tool when deciding how best to treat re-recurrence after anterior and posterior inguinal hernia repair. In one case severe adhesions after robotic prostatectomy and in another case correct placement of the mesh in the posterior plane, adhesions from the cecum to the groin region and no definitive finding of a re-recurrence resulted in an open repair. In the third case, an insufficient laparoscopic posterior mesh placement made the re-recurrent TAPP procedure relatively easy.Explorative laparoscopy is an important decision tool for re-recurrent inguinal hernia treatment to minimize the risks of the procedure for the patients. Operation for a recurrent inguinal hernia is common 12%) (2% 1–4),,4), and After previous posterior laparo-endoscopic primary repair and open anterior recurrent operation, the re-recurrence rate on 1-year follow-up is 1.1% . SimilarIn such settings, the new “HerniaSurge Guidelines for groin hernia management” recommend that an expert surgeon should repair a re-recurrent inguinal hernia after failed anterior and posterior repair. The choice of technique depends on patient- and surgeon-specific factors . ClinicaLaparoscopy represents a further diagnostic modality. Diagnostic laparoscopy can not only confirm once again the re-recurrence diagnosis but will provide further valuable information for better management of the re-recurrence operation. For example, this will help decide between a repeat of open or laparoscopic repair in the interest of risk minimization for the patient.Based on three case reports, this paper now aims to demonstrate the advantages of diagnostic laparoscopy for management of re-recurrence after previous anterior and posterior inguinal hernia repair.A 50-year-old patient underwent TAPP operation in 2010 for primary unilateral inguinal hernia. This was followed in 2011 by Lichtenstein operation for recurrent repair. Then once again the patient experienced symptomatic recurrence. To confirm the diagnosis and assist in preoperative management we first carried out explorative laparoscopy, which revealed a medial re-recurrence with inadequate dissection and mesh placement at the time of primary repair in TAPP technique Figures . It was A 75-year-old patient underwent bilateral TAPP operation in 1998 for primary bilateral inguinal hernia. In March 2015, robotic radical prostatectomy had to be performed. In September 2016, the patient experienced symptomatic recurrent inguinal hernia, which was repaired in Lichtenstein technique. Around 1 year after Lichtenstein operation another recurrent inguinal hernia developed. We operated on that in January 2017 after first carrying out explorative laparoscopy. The latter revealed extensive adhesions in the region of the left groin (Figure A 54-year-old patient underwent TAPP operation in 2006 for right primary inguinal hernia. This was followed in 2012 by Shouldice operation because of a recurrence. Then in 2016 the patient developed a symptomatic re-recurrence, which was treated by us again in January 2017. Explorative laparoscopy showed widespread adhesions of the cecum to the TAPP repair region Figure . OtherwiAll guidelines of the international hernia societies recommend laparo-endoscopic repair for recurrence after primary open inguinal hernia repair and open repair for recurrence after laparo-endoscopic primary repair –11. WhilThe problem encountered when treating patients with re-recurrences following anterior and posterior mesh implantation is that a mesh has already been implanted into both anatomic tissue planes, which will hamper any further repair procedure. Diagnostic imaging modalities such as ultrasound, CT and MRI in general do not help decide which surgical technique should best be used, but can demonstrate findings like seroma, hematoma or lipoma. Based on our experience, explorative laparoscopy is a useful tool in this setting. As borne out by the cases described above, the explorative laparoscopy findings help decide which repair technique poses fewest risks to the patient and is likely to assure a better outcome Figure . Armed wIn summary, it can be stated that diagnostic explorative laparoscopy is a useful decision tool for treatment of re-recurrence after anterior and posterior inguinal hernia repair.All subjects gave written informed consent in accordance with the Declaration of Helsinki.FK: clinical cases, literature review, and manuscript writing. CS-P: literature review and manuscript writing.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Plasmodium knowlesistudies involving longitudinal infections of rhesus macaques (M.mulatta). The variant proteins, known as the P. knowlesiSchizont Infected Cell Agglutination (SICA) antigens and the P.falciparum Erythrocyte Membrane Protein 1 (PfEMP1) antigens, expressed by theSICAvar and var multigene families, respectively, havebeen studied for over 30 years. Expression of the SICA antigens in P.knowlesi requires a splenic component, and specific antibodies are necessary forvariant antigen switch events in vivo. Outstanding questions revolvearound the role of the spleen and the mechanisms by which the expression of these variantantigen families are regulated. Importantly, the longitudinal dynamics and molecularmechanisms that govern variant antigen expression can be studied with P.knowlesi infection of its mammalian and vector hosts. Synchronous infections canbe initiated with established clones and studied at multi-omic levels, with the benefit ofcomputational tools from systems biology that permit the integration of datasets and thedesign of explanatory, predictive mathematical models. Here we provide an historicalaccount of this topic, while highlighting the potential for maximizing the use ofP. knowlesi – macaque model systems and summarizing exciting newprogress in this area of research.Antigenic variation in malaria was discovered in  Plasmodium infected RBCs (iRBCs) is critical to parasite survival. Inturn, host immune responses against these proteins are important for host survival and theestablishment and maintenance of chronic asymptomatic malaria infections  variantantigens, which are encoded by the large var multigene family with about 60members dispersed throughout all 14 chromosomes, with the majority located near thetelomeres  variant antigens  SICA[+] and SICA[−]clones, which do or do not express the variant antigens, respectively  model allows for experimental passagethrough the mosquito host, thereby offering the opportunity to observe possible resetpatterns of SICAvar gene expression and to monitor the within-hostexpression dynamics for the first time during the course of longitudinal infections. Inaddition, the Anopheles dirus mosquito can be reared in the laboratory,providing an experimental model system for the study of regulatory mechanisms of antigenicvariation that may occur in the vector. This vector has been implicated in naturalP. knowlesi and P. falciparum transmission in the region. Arefined Macaca mulatta genome  by combining long-read sequences(PacBio) and genome-wide high-throughput chromosome conformation capture (Hi-C) data toproduce accurate, chromosome-level scaffolds, followed by automated and manual annotation,including for all SICAvar genes. This genome sequence has been named the‘MaHPIC Pk Genome Sequence’ and is being reported elsewhere in this Special Issue 1+ clonalparasites. This gene was reported with a 10-exon structure  to Pk1(B+)1+phenotypes 1+ parasites, with representation of variousgene family members in a cDNA library but without particular dominant transcripts noted.Yet, northern blots demonstrated a dominant 205 kDa protein-encoding stage-specificfull-length transcript in the ring stages of the Pk1(B+)1+ but not the Pk1(A+) parasites cells produce the repertoire ofSICAvar transcripts observed in different SICA[+] clones.The large .et al. suggesteSICAvar gene encoding the 205 kDa SICA protein contrasts withthe much simpler two-exon structure of var genes in P.falciparum   and Pk1(B+)1+ parasite clones, and demonstrated a completeswitch in SICA expression with dominant proteins and lesser proteins identified in eachclone  to the Pk1(B+)1+ phenotype resultedin the downregulation of one set of SICAvar genes and the upregulation ofanother set. The results, also reflected in northern blots, strongly suggested that bothtranscription and post-transcription processes were functioning to regulate the expressionof these genes and proteins ; this suggests that changes haveoccurred in this line over time upon in vitro propagation that nowprohibit its successful infection and growth in vivo.Comparisons of SICA[+] and SICA[−] parasites furthermore revealed that the.et al.  did not SICAvar gene expression may be regulated by non-coding RNAs that areantisense to those genes, supporting the possible involvement of post-transcriptionalregulatory processes  and other techniques of modernmolecular biology have indicated that multiple P. falciparum vartranscripts can be present at the same time in single cells . Most mechanistic studies on variant antigens have been performed on populations of cells,due to the historical limitations of single-cell technologies, and these populations wereoften derived with receptor binding/panning selection methods  strain and Saimiri sciureus monkeys  of these structures has yet to be defined, though they are of high interest,as they likely perform critical physiological functions, and could become targets ofintervention against P. knowlesi, as well as other species.Aside from having a clear role in parasite virulence, the biological function of SICAproteins and their precise localizations on the host cell membrane are still unknown. Asboth SICA[−] and SICA[+] expand rapidly in splenectomized hosts, the function of SICAproteins is not thought to be metabolic  type of model with aLotka-Volterra model of interspecies competition. The SIR formulation could be used todescribe how different variants infect susceptible RBCs and thus produce differentSICA-expressing iRBCs. The Lotka-Volterra formulation could add a variant-specific andcross-reactive  with Hi-Ctechnology  and 22‘SICAvar gene segments’ that mainly  contain the first two or last 3 exons  epigenetic mechanisms withinthe parasite can drive in vivo switching of variant antigen expression;(iii) host factors can drive epigenetic control of antigenic variation in the parasite;and (iv) variant antigen switches and the switching rate correlate with antibody responsepatterns. As the scientific community takes on these challenges, it may also become viableto effectively explore selected question using P. falciparum – NHPmodels. One day, interventions may come to light that can interrupt switching mechanismsand thus accelerate the elimination of parasites, which would otherwise remain disguisedand survive the host's immune response.Many hypotheses regarding the molecular and immunobiological basis of antigenic variationin malaria, can effectively be addressed with


Defects in regulatory T cells (Treg cells) aggravate multiple sclerosis (MS) after its onset and the absence of Treg cell functions can also exacerbate the course of disease in an animal model of MS. However, autoimmune neuroinflammation in many MS models can be acutely provoked in healthy animals leading to an activation of encephalitogenic T cells despite the induction of immune tolerance in the thymus including thymically produced (t)Treg cells. In contrast, neuroinflammation can be ameliorated or even completely prevented by the antigen-specific Treg cells formed extrathymically in the peripheral immune system (pTreg cells) during tolerogenic responses to relevant neuronal antigens. This review discusses the specific roles of Treg cells in blocking neuroinflammation, examines the impact of peripheral tolerance and dendritic cells on a relevant regulation of neuroinflammation, and explores some of the most recent advances in elucidation of specific mechanisms of the conversion and function of pTreg cells including the roles of CD5 and Hopx in these processes. The specific autoimmune mechanisms underlying MS involve unchecked activation of autoreactive T cells , 2. Neurimmunity , 9.+ regulatory T cells (Treg cells) play a pivotal role in protection and recovery from EAE and MS by suppressing autoreactive T cells and either the absence of tTreg cells or their abnormal functions can exacerbate the severity of EAE  . Furthereg cells –75. Thers of EAE , 68, 76.is issue , 78. Theeg cells , 78. Howantigens . In agre T cells , 78. Fur T cells . Similar T cells . Overall T cells –84.neg precursors through the mechanisms of peripheral tolerance. In the absence of this active de novo conversion of pTreg cells, animals remain fully susceptible to EAE similar to what is observed in mice that have a global genetic deficiency preventing either extrathymic generation of such pTreg cells or their functions and survival (ex vivo and then re-injected into animals could prevent EAE similar to soluble tolerogenic antigens that can also be picked up by DCs in vivo (in vivo using recombinant chimeric antibodies specific for DEC205 expressed on DCs (de novo induction of Foxp3 expression in extrathymic T cells converting them into pTreg cells and such pTreg cells were then also found to protect from EAE (hi T cells into pTreg cells by modulating their responsiveness to effector cell-differentiating cytokines through blocking the activation of the mechanistic target of rapamycin (hi DCs through engagement of HVEM, a receptor for BTLA (In contrast to pre-existing tTreg cells, antigen-specific pTreg cells first need to be converted extrathymically from the Foxp3survival , 78. Altsurvival , 63, DCssurvival –88. In tsurvival , 89–91.  in vivo –94. The d on DCs . Overalld on DCs , 78, 79.from EAE . Tolerogfrom EAE , 96–100.from EAE , 101–105from EAE , 107. Sufrom EAE –111. Recapamycin . In addifor BTLA .+ Treg cells in MS patients may contribute to a defective suppression in MS (+ signaling in effector T cells and this suppressor function appears to be defective in Treg cells in some MS patients as well (There are multiple molecular mechanisms of immune suppression by Treg cells as excellently described in Ref. , 112–114on in MS . Other son in MS –137. Hum as well , 139. In as well . Overallin vivo can also lead to a disappearance of Treg cell populations despite their initial expansion (−/− pTreg cells can be restored by genetically ablating IL-2 expression, suggesting that increased intrinsic IL-2 expression in the absence of Hopx may be detrimental in pTreg cells (It remains unclear if the crucial molecular mechanisms of suppression differ between tTreg cells and pTreg cells. Although Hopx is expressed in both tTreg cells and pTreg cells, only pTreg cell functions and survival rely on Hopx , 78. Thexpansion , 141–148eg cells .de novo-induced pTreg cells that are specific for various myelin antigens might be an attractive option to effectively treat MS in addition to efforts focused on enhancing the functions of already existing Treg cells during the course of disease.Studies using EAE have helped to define the pathology associated with the human disease MS and helped establish that Treg cells are vital to prevent CNS autoinflammation. Currently used therapies for MS are still not curative and often produce harmful side effects , 149–152Both authors wrote and approved the final version of the manuscript.The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.


Background. Lipomatous hypertrophy of the atrial septum (LHAS) is a rare entity characterized by mass-forming deposition of fatty tissue within the atrial septum. To date, <300 cases have been reported; many of them were autopsy findings. The clinical presentation of LHAS varies from incidental asymptomatic mass (most frequent form) to severe life-threatening cardiovascular complications necessitating emergency cardiac surgery. Case Presentation. Here, we present the successful surgical resection of such a massive LHAS which was found incidentally on preoperative investigation of a 71-year-old patient with progressive coronary heart disease. Histology confirmed the diagnosis of lipomatous hypertrophy of the atrial septum. Conclusions. The described case report illustrates an unusual example of LHAS in a patient undergoing a planned coronary artery bypass surgery. In this case, surgical intervention was justified to avoid later outflow obstructions.  Lipomatous hypertrophy of the atrial septum (LHAS) is a relatively uncommon benign abnormality characterized by accumulation of unencapsulated mass-forming mature fat within the atrial septum , 2. The The radiological evaluation of cardiac mass-forming lesions has been greatly facilitated by the development of high-resolution noninvasive cardiac imaging , 9. NeveThis article demonstrates the necessity to also include LHAS in the differential diagnosis of subtle and nonspecific cardiothoracic symptoms.A 70-year-old Caucasian male with coronary heart disease and symptoms of heart failure was referred to our hospital. He noted progressive dyspnea, arterial hypertension, and exhaustion. At admission, the patient presented a blood pressure of 150/90 mmHg and a heart rate of 80 beats per minute. Transthoracic echocardiography (TTE) revealed a dilated left atrium and ventricle with a highly impaired left ventricular ejection fraction of 30%. The heart valves appeared almost unremarkable with slight aortic and mitral valve regurgitation. Subsequent invasive coronary angiography showed significant stenosis of the ramus circumflex (RCX) and the right coronary artery (RCA); the left main and the anterior descending artery showed slight narrowing only.The patient was taken to the operating theatre, where a median sternotomy was performed and cardiopulmonary bypass was performed through aorto-right atrium cannulation. Intraoperative transesophageal echocardiography (TEE) demonstrated a large mass within the interatrial septum. After opening of the right atrium (RA), the large retractile sessile mass was successfully excised. The resulting defect in the RA was then closed with a pericardial patch. Afterwards, two single saphenous vein grafts were anastomosed to the RCX and the RCA. The patient was weaned from cardiopulmonary bypass without any signs of cardiac failure. He made an uneventful recovery, was extubated on postoperative day 2, and transferred to the intermediate care on day 4. Before leaving the hospital on day 9 after surgery, the TTE showed a moderate impaired ventricular function, well-functioning heart valves, and no pericardial effusions.The gross specimen measured 3,7 × 2,5 × 1,2 cm and was covered by glistening endocardium. On cut surface, it was entirely composed of yellowish smooth glistening fatty tissue occupying and expanding the atrial septum . HistoloBenign lipomatous tumors of the heart are exceptionally rare. They encompass mainly lipoma and LHAS. In a recent large series of 47 cases collected over a period of 19 years at the Mayo Clinic , only fi HGMA2 gene rearrangement in one case of LHAS suggesting a true neoplasm, but the limited number of cases examined does not allow for definitive conclusion regarding this point. There are no typical clinical symptoms of LHAS, but atrial arrhythmias, like atrial fibrillation and supraventricular tachycardia, are common [LHAS is rare , 15. Sine common . Usuallye common , 20. fossa ovalis [The diagnosis of LHAS is made either preoperatively with noninvasive imaging techniques or coincidentally at time of cardiac surgery like in the present case. The usual imaging to evaluate LHAS is transthoracic and transesophageal echocardiography, where the septum appears unusually thick sparing the membrane of thea ovalis , 21. Sura ovalis , 23. HisThe reported case illustrates an unusual example of LHAS in a patient undergoing a planned coronary artery bypass surgery. In these cases, surgical intervention is justified to avoid later outflow obstructions. The histological examination of such cardiac lesions is mandatory to exclude other fatty masses of the heart, in particular liposarcomas.


Specifically, 12 week-old C57BL/6J mice underwent OVX/SHM surgery; 9 weeks after we inserted special metal-ceramics implants into the 6th caudal vertebra and we measured bone response with in vivo micro-CT weekly for the following 6 weeks. Our results indicated that ovariectomized mice showed a reduced ability to increase the thickness of the cortical shell close to the implant because of impaired peri-implant bone formation, especially at the periosteal surface. Moreover, we observed that healthy mice had a significantly higher loss of trabecular bone far from the implant than estrogen depleted animals. Such behavior suggests that, in healthy mice, the substantial increase in peri-implant bone formation which rapidly thickened the cortex to secure the implant may raise bone resorption elsewhere and, specifically, in the trabecular network of the same bone but far from the implant. Considering the already deteriorated bone structure of estrogen depleted mice, further bone loss seemed to be hindered. The obtained knowledge on the dynamic response of diseased bone following implant insertion should provide useful guidelines to develop advanced treatments for osteoporotic fracture fixation based on local and selective manipulation of bone turnover in the peri-implant region.Although osteoporotic bone, with low bone mass and deteriorated bone architecture, provides a less favorable mechanical environment than healthy bone for implant fixation, there is no general agreement on the impact of osteoporosis on peri-implant bone (re)modeling, which is ultimately responsible for the long term stability of the bone-implant system. Here, we inserted an implant in a mouse model mimicking estrogen deficiency-induced bone loss and we monitored with longitudinal  The remarkable load-bearing ability of healthy bone is based on a constant renewal of bone tissue as well as on a continuous adaptation of bone architecture to changes in the mechanical demands. The biological process responsible for bone maintenance and adaptation comprises both the removal of aged or mechanically redundant bone and the formation of new bone. Resorption and formation can either be spatially coupled with formation following resorption at the same site  or occurring at different locations (even far apart) and therefore allowing for growth and changes in bone architecture (a process named bone modeling). The general term used to describe all processes involving bone formation and resorption with no distinction between spatially coupled or un-coupled events is bone (re)modeling .Impairments in the (re)modeling process such as increase in bone turnover together with an imbalance between formed and resorbed bone can lead to a rapid loss of bone mass  accompanin vivo micro-computed tomography (micro-CT) to monitor the spatio-temporal changes in peri-implant bone (re)modeling have demonstrated that bone responds to the presence of the implant essentially by increasing the rate of bone formation as well as of bone resorption in a time and location specific manner [Implant placement modifies bone (re)modeling: recent studies using longitudinal c manner , 21. Whec manner –24 whilec manner –28 or dic manner . In all c manner , but it c manner , 31.th caudal vertebra of mice. The animals at 12 weeks of age underwent OVX/SHM surgery; 9 weeks after ovaries removal we performed implantation and we monitored bone response for the following 6 weeks using longitudinal in vivo micro-CT imaging. We hypothesized that OVX animals would exhibit an impaired bone (re)modeling process with peri-implant bone formation and resorption being jeopardized by estrogen removal. We further hypothesized that such modifications would have a negative impact on peri-implant bone structure with a decreased ability to augment bone mass around the implant.In the present study, we investigated the time course of bone formation and resorption as well as the corresponding architectural modifications following the insertion of special metal-ceramics implants  into theFor the animal experiment, described according to the ARRIVE Guidelines , 12-weekin vivo imaging experiment is displayed in in vivo micro-CT . The first two scans were performed before OVX/SHM surgery and 9 weeks after surgery , respectively. The third scan was acquired right after implant insertion (week 0), and the remaining measurements were performed weekly for the following 6 weeks . The second and third scans were performed one day apart to measure structural parameters right before and after implant insertion, with the aim to monitor early structural changes due to implantation. The scanning procedure followed an optimized protocol for bone-implant systems [The timeline of the  systems : images  systems  distribu systems –37.in vivo micro-CT imaging of mouse vertebrae [3 , was used to separate the bone-implant system from the background , full vertebral length (VL) along the cranio-caudal axis of the entire CV6 (including growth plates), cortical thickness (Ct.Th), cortical area fraction (Ct.Ar/Tt.Ar), cortical porosity (Ct.Po), trabecular bone volume fraction (BV/TV), trabecular thickness (Tb.Th) and trabecular number (Tb.N). Those parameters were measured right before OVX/SHM surgery, 9 weeks after surgery and for the 6 consecutive weeks after implantation. Bone (re)modeling was characterized by bone formation rate (BFR), bone resorption rate (BRR) and net rate of bone (re)modeling . Formation and resorption rates were computed based on formed and resorbed voxels  within amicro-CT . At the micro-CT .Architectural and (re)modeling parameters were tested for significant differences between OVX and SHM using the Mann-Whitney Rank Sum Test as the two groups did not always follow a normal distribution indicated by the Kolmogorov-Smirnov normality test nor did they always have equal variance in each time point. The Mann-Whitney Rank Sum Test is considered a suitable alternative to ANOVA when the assumption for normality and equal variance of the data cannot be met. Since during the monitoring time, the two groups did not receive any specific repeated treatment  we were not concerned about possible interactions among multiple factors. The same test was used to investigate differences between periosteal and endocortical surface within OVX and SHM mice. To test the significance between the first and last time point within the same group a paired t-test was used after verifying normal distribution of the data; a Wilcoxon Signed Rank Test was applied otherwise. P-values smaller than 0.05 were considered significant and all data are shown as mean ± standard error.Ovary removal deteriorated the structure of both cortical and trabecular bone in the mouse caudal vertebra CV6 . Nine weA common feature of both periosteal and endocortical surfaces of peri-implant cortical bone is that bone formation rate (BFR) increased transiently after implant insertion as indicated by the peak-shaped curves of both SHM and OVX animals . In SHM,In the peri-implant trabecular bone, (re)modeling rates of OVX and SHM were not statistically different . Both grIn the region far from the implant, (re)modeling rates of SHM and OVX had substantially different time courses, especially considering bone formation . In the Post implantation, OVX and SHM had also substantially different behaviors in the rate of trabecular bone formation far from the implant. At early stages after implantation, BFR in OVX was up to a factor of three higher than in SHM modeling process following implant insertion caused substantial modification in bone architecture . Peri-imConsidering bone located far from the implant surface, the different (re)modeling behaviors at the periosteal and endocortical surfaces resulted in a virtual steady-state cortical bone architecture, as indicated by a marginal increase in cortical thickness for both OVX and SHM, with no significant differences in the relative increase over time between groups . Again, Considering whole bone changes, variations in vertebral length (VL) after implant placement were minor, with OVX and SHM showing similar trends . In partin vivo micro-CT, we investigated bone formation, bone resorption, and the consequent architectural modifications around the implant and in the whole implanted bone for 6 weeks following implantation. Specifically, we detailed the (re)modeling behavior on three different surfaces, which are known to respond differently to implant insertion [In this study, we followed the changes in bone (re)modeling and bone architecture after implant insertion in healthy and estrogen-depleted mice. Although it is fairly clear that osteoporotic bone, with low bone mass and deteriorated bone architecture, provides a less favorable mechanical environment than healthy bone for implant fixation, there is no general agreement on the impact of osteoporosis on peri-implant bone (re)modeling, which is ultimately responsible for the long term stability of the bone-implant system. Here, using a mouse model mimicking estrogen deficiency-induced bone loss combined with longitudinal nsertion , 28 as wnsertion , 44. In nsertion .in vivo micro-CT images, a generally higher BRR was measured at the endocortical surface compared to periosteal bone in both groups. In genetically similar adult mice, periosteal resorption has been shown to be practically absent [In our study, the main feature of peri-implant bone formation was a short—term acceleration of BFR in all the regions examined, with the relative increase in BFR being higher in healthy than estrogen depleted bone. Another study also reported a transient increase in formation rate post-implantation around the implant  but did y absent , therefoy absent , implanty absent . Far froy absent ) was alry absent .One factor that could potentially contribute to (re)modeling differences between SHM and OVX may be the susceptibility to inflammatory reaction following implant insertion. Inflammation is a key player in the sequence of biological events occurring after implantation, especially in the early stages of the bone response . AlthougDifferences in bone (re)modeling were directly responsible for dissimilar modifications in peri-implant architecture; among all the architectural parameters measured  we focusex vivo measurements (including repositioning between the scans) of vertebrae measured after animal sacrifice and registered on the in vivo dataset: the quantity of erroneously formed/resorbed voxels per bone volume was less than 5% [in vivo micro-CT of entire mice vertebrae as well as of specific regions of mice tibiae showed very high correlations with dynamic histomorphometry, which is considered gold standard to quantify bone remodeling [There were limitations in the presented study that need to be mentioned. The statistical tests performed when data was not normally distributed may be less stringent than traditional ANOVA and, as a consequence, small differences that were identified as statistically significant should be interpreted with some caution. However, the main conclusions of our work are based on parameters which show high variations  between SHM and OVX at least in one time interval, namely: Ct.Th and BV/TV  as well  than 5%  and, in  than 5% , 54, 55.modeling , 31. Themodeling : therefomodeling , 58, in modeling , 52, 59.modeling , 61. We In conclusion, our hypotheses that OVX animals would have a decreased ability to modify bone (re)modeling and that the corresponding structural changes in peri—implant bone would be less effective for implant stability were confirmed in cortical bone. There, due to disturbed bone formation, estrogen depleted animals had a reduced capability to thicken the cortical shell in response to implant placement, which in turn indicates decreased implant fixation strength . We alsoS1 File(PDF)Click here for additional data file.


The severe fever with thrombocytopenia syndrome virus (SFTSV) is an emerging, highly pathogenic bunyavirus against which neither antivirals nor vaccines are available. The SFTSV glycoproteins, Gn and Gc, facilitate viral entry into host cells. Gn and Gc are generated from a precursor protein, Gn/Gc, but it is currently unknown how the precursor is converted into the single proteins and whether this process is required for viral infectivity. Employing a rhabdoviral pseudotyping system, we demonstrate that a predicted signal sequence at the N-terminus of Gc is required for Gn/Gc processing and viral infectivity while potential proprotein convertase cleavage sites in Gc are dispensable. Moreover, we show that expression of Gn or Gc alone is not sufficient for host cell entry while particles bearing both proteins are infectious, and we provide evidence that Gn facilitates Golgi transport and virion incorporation of Gc. Collectively, these results suggest that signal peptidase liberates mature Gc from the Gn/Gc precursor and that this process is essential for viral infectivity and thus constitutes a potential target for antiviral intervention. Bunyaviruses constitute the largest RNA virus family and infect a wide range of hosts, including humans, arthropods and plants. Several emerging bunyaviruses pose a considerable threat to human health as exemplified by Rift Valley fever virus (RVFV) , CrimeanBunyaviruses contain a tripartite RNA genome consisting of three single stranded RNA segments of negative polarity termed L, M and S. The M segment encodes for the viral envelope proteins Gn and Gc, which facilitate viral entry into target cells and are the major targets for neutralizing antibodies ,14. In aBunyavirus Gn and Gc are generated from a precursor polyprotein, frequently termed Gn/Gc, which is proteolytically processed into the single Gn and Gc proteins and, in case of CCHFV and several other bunyaviruses, into additional viral glycoproteins and a non-structural protein, NSm . For somHere, we show that processing of the Gn/Gc precursor into Gn and Gc is a prerequisite to infectious viral entry and we provide evidence that Gn promotes virion incorporation of Gc. Moreover, we demonstrate that potential proprotein convertase cleavage sites in Gc are dispensable for processing of the Gn/Gc precursor, while the integrity of a predicted signal sequence at the N-terminus of Gc is essential. These findings indicate that the cellular enzyme signal peptidase liberates Gc from the Gn/Gc precursor and that this process is required for viral infectivity.2. The cells were obtained from collaborators and their identity was confirmed by STR DNA typing employing a published protocol -N-[2-(2-methoxyphenyl)ethyl]-N-(3R)-3-pyrrolidinyl-benzamide dihydrochloride) . All inhibitors were diluted in solvent as recommended by the manufacturers and applied in the indicated concentrations. Target cells were treated with the inhibitors from 6 h post transfection until cells were harvested.For analysis of viral entry a previously described rhabdoviral pseudotyping system was used . In brie2O prior to mounting onto a microscope slide with mowiol. Fluorescence images were acquired with the confocal laser scanning microscope LSM 5 Pascal Axioskop 2 MOT plus  using a 63x, NA1.4 Zeiss Plan Apochromat objective and LSM Pascal 5 software version 3. Confocal images were colored and converted to JPEG using the software AxioVision Rel. 4.8 (Carl Zeiss Microimaging GmbH). All images were cropped to 70% of the original image for presentation purposes. No further image modifications were performed.COS-7 cells were seeded on glass coverslips in 24-well plates at 40,000 cells per well and incubated for 24 h at 37°C. Subsequently, the cells were calcium-phosphate cotransfected with 0.5 μg of plasmids encoding viral glycoproteins (SFTSV-Gn-myc and/or SFTSV-Gc-V5 or SFTSV-Gn/Gc-V5) and marker proteins localized to the endoplasmic reticulum  or GolgStatistical analysis was performed by Welch’s t-test .We first asked whether expression of the SFTSV-Gn/Gc precursor protein results in production of mature Gn and Gc proteins in 293T cells, a highly transfectable cell line previously used to generate infectious SFTSV-Gn/Gc-bearing vectors . For thiFor EBOV-GP and LASV-GPC, the expected C-terminal processing products of 20 kDa and 35 kDa were detected in addition to the precursor proteins , indicatWe next asked whether Gn and Gc proteins can be expressed separately and whether expression of both proteins is required for host cell entry. Mature Gn and Gc are predicted to exhibit almost identical molecular weights of 60 kDa and 58 kDa, respectively, and the corresponding bands were indeed detected in cells transfected with separate expression plasmids encoding these proteins . For at Based on our finding that separate expression of Gn and Gc is feasible, we next asked whether both proteins are required for infectious entry. For this, we employed a vesicular stomatitis virus (VSV)-based pseudotyping system previously shown to be suitable for analysis of SFTSV-Gn/Gc-driven entry . ParticlMature Gc was incorporated into particles upon expression of the Gn/Gc precursor protein but not upon expression of Gc alone, as discussed above. These findings posed the question whether Gn facilitates virion incorporation of Gc. To investigate this possibility, particle incorporation of the viral glycoproteins and infectivity were analyzed upon coexpression of vector with combinations of Gn and Gc proteins harboring either the V5 or the myc antigenic tag. These studies confirmed that expression of Gc alone is not compatible with particle incorporation and infectivity . In addiThe finding that Gn is required for virion incorporation of Gc raised the question whether Gn might facilitate the transport of Gc to the site of viral budding, the Golgi apparatus. To address this question, we analyzed the cellular localization of epitope tagged Gn, Gc and Gn/Gc via confocal laser scanning microscopy. Cellular proteins fused to GFP and known to localize to the endoplasmic reticulum  and the Golgi apparatus , respectively, were employed as organelle markers. We found that Gn and Gn/Gc were predominantly localized to the Golgi apparatus while Gc alone was mainly found in the ER . MoreoveWe next asked which protease is responsible for Gn/Gc processing into mature Gn and Gc. In silico analyses predicted signal peptides at the N-termini of Gn and Gc . MoreoveNone of the mutations tested interfered with processing of the Gn/Gc precursor protein , althougEvidence has been reported that the Gn/Gc proteins of certain bunyaviruses can be processed by signal peptidase during ER import –21 and iBunyavirus entry into cells is the first essential step in viral replication and the choice of entry factors can constitute a pathogenic molecular signature ,35. The phlebovirus and is most closely related to the Bhanja serogroup viruses [SFTSV is a member of the genus  viruses . The M s viruses . These fWe first considered the possibility that two RRxR motifs located at positions 5 and 113, respectively, in SFTSV-Gc might constitute target sites for proprotein convertases, which are known to recognize the following consensus motif, (R/K)-2nX-R2 (with n 0–3 amino acids) –39. SuchWe next asked whether signal peptidase might liberate Gc from Gn/Gc. This question was instigated by sequence analysis, which predicted the presence of a signal sequence at the N-terminus of Gc. Notably, the four amino acid residues preceding the predicted cleavage site in SFTSV-Gc (positions -4 to -1) as well as the amino acid residue at position +1 were found to be highly conserved among phleboviruses and residues -4 to -1 matched those most frequently found in signal peptides of cellular proteins. These findings are in line with previous reports documenting a role for signal peptidase in production of the Gc proteins of Uukuniemi virus, RVFV and Hantaan virus –21. The in silico analyses and the X-ray structure of the Rift valley fever virus Gc, bunyavirus Gc proteins were identified as class II membrane fusion proteins.[The availability of SFTSV-Gn/Gc mutants allowed us to investigate whether Gn/Gc processing is required for infectivity. Unprocessed Gn/Gc was incorporated into particles but failed to facilitate transduction of target cells, demonstrating that unprocessed SFTSV-Gn/Gc is inactive. This finding is in line with the observation that expression of Gn or Gc alone in particle producing cells was not sufficient for particle infectivity, while particles generated in the presence of both proteins were infectious. This finding raised the question how Gn and Gc contributed to particle infectivity. Based on proteins.. Therefoproteins.–43. One proteins.–46. Moreproteins.. It is tproteins.,48.In sum, the present study highlights similarities between the biogenesis and biological functions of the Gn and Gc proteins of SFTSV and other bunyaviruses and reports an experimental system which allows the convenient analysis of these proteins.


He remained without evidence of recurrence one year later, having never received treatment. This case emphasizes the potential for spontaneous remission in NHL and demonstrates that this phenomenon can be observed despite contemporary high-risk histopathologic features. Non-Hodgkin lymphomas (NHL) are a heterogeneous group of hematologic malignancies typically treated with multiagent chemotherapy. Rarely, spontaneous remissions can be observed, particularly in more indolent subtypes. The prognosis of aggressive NHL can be predicted using clinical and histopathologic factors. In aggressive B-cell NHL, the importance of MYC and BCL2 proto-oncogene coexpression (as assessed by immunohistochemistry) and high-grade histologic features are particularly noteworthy. We report a unique case of spontaneous remission in a patient with an aggressive B-cell NHL which harbored high-risk histopathologic features, including MYC protein expression at 70–80%, BCL2 protein expression, and morphologic features suggestive of high-grade B-cell lymphoma, NOS (formerly B-cell lymphoma unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt lymphoma [BCLU]). After undergoing a biopsy to confirm this diagnosis, he opted to forego curative-intent chemotherapy. The single, yet relatively large area of involvement noted on  Non-Hodgkin lymphomas (NHL) are a heterogeneous group of hematologic malignancies that typically require multiagent cytotoxic chemotherapy and demonstrate a broad range of outcomes. Treatment of B-cell NHL typically relies upon multiagent cytotoxic chemotherapy , tailored to the specific subtype of NHL and certain patient characteristics. With the addition of rituximab (R), a chimeric monoclonal antibody targeting the B-cell antigen CD20, outcomes have improved broadly for patients with B-cell NHL , 2. Desp myc oncogene has prognostic significance when its expression is altered by gene rearrangement, as these often involve the promoter regions of immunoglobulin heavy or light chain genes, leading to overexpression in and proliferation of malignant B-cells .We present, to the best of our knowledge, the first reported case of spontaneous remission in an aggressive NHL harboring the poor prognostic features of MYC and BCL2 protein coexpression. With the improvements in IHC and other molecular and genetic testing, it is certainly feasible that prior reported cases of spontaneous remission in HGBL and DLBCL may have also demonstrated MYC and BCL2 coexpression that went undiscovered. Additionally, since the standard approach to a newly diagnosed, high-grade lymphoma is immediate intervention with aggressive chemotherapy, this treatment paradigm may have precluded other cases with the potential for spontaneous remission.Complete remission in our patient is most remarkable, considering the expected poor prognosis associated with the protein overexpression (BCL2 and MYC) and cellular populations identified in his disease. Despite clinically favorable features , negative FISH for translocations in MYC, BCL2, or BCL6 , and a germinal center B-cell (GCB) subtype lymphoma as determined by the Hans algorithm CD10 positive) (felt to represent a more favorable prognostic feature), the immunohistochemical features predicted a much worse outcome , 14–16.  positiveThe physiology of spontaneous remission remains unknown, although several proposed mechanisms exist. One leading hypothesis involves stimulation of an antitumor response from the host immune system, particularly immune activation secondary to infection or injury. Activation of antitumor immunity subsequent to local tissue injury and inflammation from a biopsy has been suggested previously in the literature, although the temporal relationship between intervention and decreasing lymph node size (as in our patient) may simply be coincidental , 21. SpoThe potential processes behind immunologic stimuli inducing remission are many and varied, but a unifying thought involves the immune system gaining the ability to recognize and react to malignant cells which were otherwise able to evade recognition. Therefore, any insult that activates host immunity theoretically enhances the possibility of host recognition of malignant cells. One mechanism for evading T-cell mediated cytotoxicity receiving extensive attention is expression of inhibitory ligands of immune checkpoint receptors . Binding of these ligands on immune cells promotes T-cell receptor attenuation, which results in protection of the target tissue  . MonocloIn summary, spontaneous remission of an aggressive NHL is a rare phenomenon with limited documentation in the medical literature. Complete remission without any specific intervention has not previously been reported in a patient like ours with such poor prognostic histopathologic features. Due to the expected poor outcome generally for patients with these characteristics, it is inadvisable to defer treatment in hopes of observing spontaneous remission in similar patients, as this aggressive disease may progress rapidly. However, the fact that spontaneous remission occurs in an aggressive, high-grade disease that historically is expected to respond poorly to intense chemotherapy is encouraging for the development of novel immunotherapeutic agents. Hopefully the intricacies of biology behind spontaneous remission in cancer (including aggressive lymphoma) will be uncovered, which may shed light on new therapeutic tools to improve the outcomes for patients afflicted with this disease.


A 74-year-old man presented with chest pain and dyspnoea at the cardiology outpatient clinic. His past medical history included an anterior myocardial infarction in 2008. In the coronary angiogram, a ‘halo image’ was seen right after the injection of the contrast agent, and it corresponded with the location of the left ventricular aneurysm. A calcified left ventricular aneurysm with mural thrombus was confirmed with cardiac MRI and a CT scan. A 74-year-old man presented with chest pain and dyspnoea at the cardiology outpatient clinic. His past medical history included an anterior myocardial infarction in 2008.His ECG revealed normal sinus rhythm with poor R-wave progression in the precordial leads. A transthoracic echocardiogram demonstrated a left ventricular aneurysm with a mural thrombus and ejection fraction of 25%. The chest X-ray showed a peculiar oval calcified image related to a left ventricle aneurysm . A nucleLeft ventriculography was not performed because of the possibility of elevated left ventricular end-diastolic pressure, which might have caused the development of acute pulmonary oedema. A calcified left ventricular aneurysm with a mural thrombus was confirmed with cardiac MRI and a CT scan , 4. The Left ventricular aneurysm (LVA) is a serious complication after acute myocardial infarction, and can lead to heart failure. Despite recent progress in revascularisation techniques, a large transmural myocardial infarction often results in the formation of a dyskinetic or akinetic LVA. This is followed by an enlarged ventricular cavity and abnormal ventricular shape that permits maximal conversion of tension generated by the myocardium into cavity pressure, and then congestive heart failure, arrhythmia and thrombogenesis.1Curvilinear calcification at the left ventricular apex strongly suggested the presence of an aneurysm. The distribution of this calcification coincided with the typical location of left ventricular aneurysms, which are usually located at the apex and often involve the anterior and lateral walls. Trauma, cardioversion, infection and endocardial fibrosis are rare causes of coarse, amorphous myocardial calcifications, which are distinct from the fine, curvilinear calcifications of a left ventricular aneurysm.2Similar previous case reports also demonstrated a calcified LVA using left ventriculography, chest X-ray, cardiac magnetic resonance imaging and computerised tomography.


Pancreatic islet transplantation has been validated as a treatment for type 1 diabetes since it maintains consistent and sustained type 1 diabetes reversal. However, one of the major challenges in pancreatic islet transplantation is the body’s natural immune response to the implanted islets. Immunosuppressive drug treatment is the most popular immunomodulatory approach for islet graft survival. However, administration of immunosuppressive drugs gives rise to negative side effects, and long-term effects are not clearly understood. A bioartificial pancreas is a therapeutic approach to enable pancreatic islet transplantation without or with minimal immune suppression. The bioartificial pancreas encapsulates the pancreatic islets in a semi-permeable environment which protects islets from the body’s immune responses, while allowing the permeation of insulin, oxygen, nutrients, and waste. Many groups have developed various types of the bioartificial pancreas and tested their efficacy in animal models. However, the clinical application of the bioartificial pancreas still requires further investigation. In this review, we discuss several types of bioartificial pancreases and address their advantages and limitations. We also discuss recent advances in bioartificial pancreas applications with microfluidic or micropatterning technology. Diabetes mellitus type 1, or type 1 diabetes, is a widespread disease where individuals are unable to produce the insulin necessary to process blood glucose because of an autoimmune response which destroys the body’s insulin-producing beta cells . As an aImmunoisolation of pancreatic islets is generally divided into three different methods of encapsulation: macro-, micro-, and nanoencapsulation  Fig.  10]. Ma. Ma10]. Extravascular approaches of macroencapsulation began with the diffusion chamber. The diffusion chamber provided an artificial barrier against larger lymphocytes and macrophages, while allowing passage of smaller nutrients, gases, and insulin. One of the well-studied diffusion chamber designs is the TheraCyte bio-artificial pancreas Fig.  11]. Th. Th11]. A study was done in which rat islets were encapsulated in the TheraCyte device and implanted within non-obese diabetic (NOD) mice . The impAnother study was conducted using a diffusion chamber with a bi-laminar encapsulation device implanted within streptozotocin (STZ)-induced diabetic rats . These rA possible remedy to the hypoxic environment seen in clumping of islet cells is immobilization of islets in layered alginate sheets. Alginate is a hydrogel consisting of anionic polysaccharides extracted from seaweed, which confers excellent biocompatibility . This laThe vascular approach to macroencapsulation offers a whole new set of advantages and disadvantages. With the incorporation of the vascular system into the macrocapsule device, nutrients, oxygen, and insulin become more readily available, resulting in better blood glucose control . HoweverIn one study, fifteen diabetic pancreatomized dogs received a hollow fiber tube device with endogenous canine islets  and titanium/titanium oxide (Ti/TiO2) . ThPancreatic islets have also been enclosed in microcapsules via interfacial photopolymerization of PEG-based macromeres. Microcapsules are formed when a dye in the cells is laser-excited, producing free radicals which trigger crosslinking. This crosslinking forms a PEG capsule around the islets. By using different dyes and concentrations and changing the irradiation parameters, the thickness of the capsule can be idealized, typically to around 50 µm. This type of microcapsule is smaller than the others mentioned previously, thus reducing the injection volume. The very thin coatings created in interfacial photopolymerization are not very biodurable due to polymer instability and insufficient crosslinking. Recently, studies have been done researching the effects of crosslinking density and its effects on protein diffusion; increased density delayed protein diffusion through the polymer membrane . The lac6 cells/mL) [In order to enhance the bioactive properties of the PEG, other peptides such as GLP-1 and ephrinA5-Fc have been immobilized along with PEG, improving the islet viability and functionality , 47. Theells/mL) , 47. Antells/mL) . Howeverells/mL) . HoweverPancreatic islets can be microencapsulated within a nanomatrix gel composed of peptide amphiphiles (PAs). PAs form an extracellular matrix (ECM)-mimicking environment to enhance islet viability without inhibiting functionality while providing an immunoisolation environment. The PA consists of a hydrophilic peptide attached to a hydrophobic C16-carbon chain , 51. TheSurface modification is a form of immunoisolation that does not rely on microencapsulating islets, but rather on altering the surface of the islets themselves to form an immune barrier. A PEG complex may be covalently bound to the surface of the islets to provide a thin barrier to macrophages and reduce the release of cytokines. For example, a succinimidyl ester-functionalized PEG can react with amine groups present upon the cell surface of pancreatic islets to conceal host immunogenic surface antigens . PEG wasl-lysine)-graft-poly(ethylene glycol) (PLL-g-PEG) copolymers were physically coated onto islet interfaces [l-lysine)-g-poly(ethylene glycol)(biotin) and streptavidin (SA), and showed comparable functionality of the LbL-modified islets compared to non-coated controls in a murine model of allogeneic intraportal islet transplantation [As an alternative approach, an electrostatic adsorption has been proposed, in which poly(terfaces . Althougantation .According to the previous summary about immune protection for implanted islets, several types of biomaterials and devices were fabricated using microfluidic or micropatterning technology. On the basis of the technical support, both microfluidic devices and micropatterned surfaces have been introduced to generate precise micro-scaled encapsulation in order to transfer islets and to protect islets against the body’s immune responses. For example, particles  and fibe2+ [2+ influx, and apoptotic factors based on the chemical gradient or dynamic culture conditions. Although technical improvement has been supported for real-time, accurate, and multifunctional investigational methods using even a single islet, there is still a great need for an intensive microfluidic device to assess the immune response from bare or encapsulated islets and to assist in pretreatment of islets before transplantation. Although many groups have attempted to encapsulate islets for protection against inflammatory responses, producing the outer structure as a carrier, the inner structure of the islets has been overlooked. For instance, flow-induced culture conditions were applied to islets by Sankar et al. [The development of microfluidic devices has largely switched to the multifunctional monitoring system for isolated islets –78. The 2+ , 75, ami2+ , or insu2+ , 76 under et al.  and demoA bioartificial pancreas is a therapeutic approach to enable immunoisolation of transplanted islets, which allows allo- and xenotransplantation of islets without or with minimal immune suppression. In this review, we have discussed various types of bioartificial pancreases including macro- and microencapsulation and islet surface modification; each strategy has some advantages and limitations. Macroencapsulation approach is useful for enclosing islets with relative ease of retrieval if necessary. However, there is a concern for clumping of the islets, which could potentially reduce oxygen and nutrient flow to the cells on the interior of the cluster. Microencapsulation approach is recently the most widely utilized strategy to encapsulate single or several islets, because it is favorable for substance exchange due to its large surface area. However, microencapsulated islets are hardly retrievable once implanted into the body, and the size or thickness of the gel and the permeability should be optimized for this application. Surface modification approach enables the generation of a very thin and finely-controlled immune barrier coating against the host immune system, but it may alter the physiology of the islets during the modification process and the coating stability should also be improved for long-term islet transplantation. From a technical point of view, microfluidic or micropatterning technology enables the development of various tools in bioartificial pancreas application, such as rapid, precise, multiplexed fabrication of nano- and micro-sized encapsulation of transplantable islets using various materials and compositions. Although previous technical development of microfluidic devices has been more focused on in vitro monitoring systems, they may also have great technical potential for encapsulating and transferring islets in the bioartificial pancreas.In interest of future applications of pancreatic islet transplantation, recent advances in the developmental biology of pancreatic organogenesis have enabled researchers to attempt the generation of fully differentiated pancreatic beta cells from embryonic stem cells or iPSCs; a bioartificial pancreas may also provide great potential for the transplantation of stem cell-derived beta cells. Despite much progress in the development of the bioartificial pancreas, its clinical applications are few and the clinical outcomes are not clear. Therefore, much effort is still needed to overcome the limitations of bioartificial pancreas applications.


Brachial cleft cysts are rare congenital malformations of the lateral neck and typically present in the second and third decades of life. Many theories have been proposed to explain the aetiology of these cysts including incomplete obliteration of branchial mucosa, persistence of vestiges of the precervical sinus and cystic lymph node origin. Preoperative imaging investigations show a fluid-filled cyst and evaluate anatomic relationships. Differential diagnosis includes metastatic squamous cell carcinoma, lymphadenitis, lymphoma, cervical dermoid cyst, cystic hygroma and parotid pathology. Surgical excision is the treatment of choice and results in a good prognosis. We present the case of a 37-year-old woman referred to our department for assessment of a neck swelling that had gradually increased in size during the previous nine months. The clinical examination found a 6 cm non-tender mass of the upper-left neck. The MRI revealed a cystic lesion measuring 4×5×6 cm, displacing the sternocleidomastoid muscle posterolaterally, and the carotid and internal jugular vein medially. The mass was completely resected through a lateral cervicotomy. The histological examination revealed a cystic wall lined with stratified squamous epithelium consistent with the diagnosis of a branchial cleft cyst. The postoperative course was uneventful. Long-term follow-up has shown no evidence of recurrence.


Background. Wear resistance of pit and fissure sealant materials can influence their retention. Wear characteristics of sealant materials may determine scheduling of check-up visits. The aim of this study was to compare wear resistance of two flowable composite resins with that of posterior composite resin materials.Methods. Thirty-five disk-shaped specimens were prepared in 5 groups, including two flowable composite resins (Estelite Flow Quick and Estelite Flow Quick High Flow), Filtek P90 and Filtek P60 and Tetric N-Ceram. The disk-shaped samples were prepared in 25-mm diameter by packing them into a two-piece aluminum mold and then light-cured. All the specimens were polished for 1minute using 600-grit sand paper. The samples were stored in distilled water at room temperature for 1 week and then worn by two-body abrasion test using "pin-on-disk" method . A Profilometer was used for evaluating the surface wear. Data were analyzed with the one-way ANOVA.Results. Estelite Flow Quick exhibited 2708.9 ± 578.1 μm2 and Estelite Flow Quick High Flow exhibited 3206 ± 2445.1 μm2of wear but there were no significant differences between the groups. They demonstrated similar wear properties.Conclusion. Estelite flowable composite resins have wear resistance similar to nano- and micro-filled and micro-hybrid composite resins. Therefore, they can be recommended as pit and fissure sealant materials in the posterior region with appropriate mechanical characteristics. Although fluoride can be effective in caries control for smooth surfaces, it is not very effective in preventing pit and fissures lesions. Therefore, pit and fissure sealant therapy is an effective method in preventing dental caries, especially during childhood and adolescent period. Although the occlusal surfaces of children’s teeth constitute almost 12.5% of total dental surfaces, 85% of total caries incidence is seen in these areas.6During the past decades, a lot of materials have been suggested for this purpose like glass- ionomers, resin-modified glass-ionomers and resin-based composites such as compomer or flowable composite resins. The critical characteristics of these materials are good fluidity and low viscosity. Also, fissure sealant materials should have good bond strength and sealing ability to remain intact during the servicing period. Some of the disadvantages of sealants are microleakage, fracture toughness and wear.7Wear resistance is an important necessity for sealant materials because it can help determine scheduling of check-up visits for evaluating sealant integrity and intactness.8Low wear resistance for sealants may lead to restoration loss or fracture and also increased roughness and more plaque accumulation, which may result in caries development.9Composite resin filler characteristics can influence composite resin wear. As the filler content of composite resin increases, we can expect more wear resistance in it in comparison to unfilled resins like pit and fissure sealant materials.10 while they can have better mechanical properties.12 Also it was shown that wear resistance of flowable composite resins improved compared with universal composite resins in recent years.13In recent years, many studies have revealed that flowable composite resins can have bond strength and sealing ability similar to fissure sealant materialsTo determine the wear resistance of Estelite flowable composite resin as a fissure sealant material in the posterior region, we conducted an experimental study to compare the wear of these flowable composite resins with that of universal and packable ones. These flowable composite resins were utilized with mono-dispersing supra-nano spherical fillers and RAP technology  for better resin polymerization. This can be useful in determining sealant servicing time and in planning checkup appointments.14Minitab software program was used by considering α = 0.05, β = 0.2, a standard deviation of 0.06 and 0.1 as the significance level. Therefore, 7 specimens were included in each group. The commercial composite resins used in this study are presented in 15Disk-shaped specimens were prepared, measuring 25 mm in diameter; therefore, they were placed by a plastic carrier instrument or injected into customized two-piece aluminum molds with a gyrate space removed from the middle part. In order to pack and smooth the surface of composite resins, two thin glass blocks were used and the composite resins were curedfor 40 seconds from each side with a hand-held LED light-curing unit  in an overlapping manner for initial curing. The laboratory light-curing device, GC Labolight LV III , was used for 60 seconds on each side of the specimens for making sure of the same conversion effect. Surface roughness was standardized by polishing specimens with 600-grit sandpapers for 1 minute. This size of sandpapers has been used in some related articles;14 therefore, 600-grit size was used manually in all the groups. Soluble ingredients were removed by storing the specimens in distilled water for one week at room temperature. The specimens were worn by pin-on-disk device in Tribology Laboratory of Metallurgy School in Tehran University.Ethics approval was not required because this was an in vitro study on dental materials. We conducted this in vitro study to compare wear resistance of two flowable composite resins: posterior universal and packable composite resins. A total of 35 specimens were prepared in 5 groups. The sample size was calculated based on the study of Yesil et al.16 They measured 5 mm in diameter. The specimens were worn under a 15-N force and at 0.05 m/s for a 100-meter distance. In order to evaluate the wear of specimens, a Profilometer  was use. The Profilometer measured surface roughness in the direction of a radius of the disk randomly and indirectly constructed a surface structure graph in micrometer scale. We could able calculate the area of wear groove in each section by scanning one of the disk’s radii randomly. We found the wear area of each specimen as a groove in its cross-section based on surface graph which was constructed by the Profilometer .ilometer . By multWear of each specimen was calculated by multiplying the wear area of the specimens from the Profilometer analysis by the perimeter of the experimental circle with a 22-mm diameter created by wear test device. 18 Also, flowable composite resins were more efficient and exhibited more penetration into shallow or wide fissures, although unfilled resins penetrates more into deep or narrow fissures.19 A meta-analysis in this field,20 and other clinical studies,22showed that flowable composite resins can have a retention rate similar to conventional pit and fissure sealants. Flowable composite resins were as effective as resin fissure sealants in caries prevention.12also In addition, it was shown that using flowable composites with total-etch technique resulted in better retention than conventional fissure sealants during a 24-months period and also better wear resistance and lesser surface porosity because of higher filler content.12 Therefore, it can be logical to use flowable composites as fissure sealant materials because of their more beneficial characteristics.It was shown that the flowable composite resin (Tetric Flow) can have no microleakage and can be more efficient than resin sealant  in sealing deep fissures.One-way ANOVA was used for inter-group comparisons. It did not show any significant differences between the experimental groups (P = 0.175). Estelite Flow Quick and High Flow composite resins exhibited wear patterns similar to those of posterior composite resins like P60 as packable and Tetric N-Ceram as universal nano-composite resins. Tukey multiple comparisons did not show any significant differences between each group pair . Consequ17Literature showed that permanent molars are susceptible to dental caries, especially during the 4-years period after eruption. Fissure sealant materials have not shown any significant differences in caries development or marginal discoloration from resin sealants but their major problems are higher wear and less retention; therefore, there has been a tendency to resin-based materials in order to increase wear resistance.23Wear resistance is an important factor in clinical dental material selection because it can influence restoration service period. Composite resin wear can be influenced by several factors such as material characteristics, including filler content, silanization or degree of polymerization and other factors such as wear period, lubricating media, surface structure, temperature and contact stress.The more the composite resin is polymerized the more resistant it becomes against wear. In order to eliminate degree of conversion as a confounding factor in our study, we provided similar curing conditions for all the experimental groups.24 Therefore, 0.1‒0.2 µm was considered as critical inter-filler space for dental composite resins.25Filler size, volume and hardness can influence wear characteristics of dental materials. By reducing the filler size, there is not a large organic matrix available between filler particles; consequently, it cannot be removed during wear procedure.13 showed in a similar study that flowable composite resins with smaller filler size can have higher wear resistance than universal nanohybrid composite resins with larger prepolymerized fillers. They explained that prepolymerized filler particles, which are used to reduce polymerization shrinkage, cannot bond chemically to resin matrix with silanization; therefore, they can be exfoliated easily and resin matrix may be displaced rather than being really lost under stress. Finally, increased wear depth may be the final result of these composite resin types. They also reported that flowable composite resins have higher fracture toughness than packable composites and similar or higher than universal composite resins; therefore, this makes them capable of mounting greater resistance against crack propagation, which reduces wear susceptibility of flowable composite resins because of resistance to material break-down under mechanical stresses.Our study results showed no significant differences between posterior packable composite resins and Estelite’s flowable composite resin. Sumino et al26 compared wear resistance of one nanohybrid flowable composite resin  with microfilled, micro-hybrid, hybrid, nanofilled and nano-hybrid composite resins in two- or three-body abrasion design. This flowable composite resin showed higher wear resistance in two-body abrasion test than other composite resins except for the microfilled one. This can be attributed to uniform and small filler particles (0.7 μm) in this flowable composite resin.Another studyEstelite flowable composite resins utilize RAP technology and supra-nano mono-dispersing silica-zirconia fillers. The fillers are spherical and 0.4 and 0.07 µm in size with fine distribution. Their organic matrix in Flow Quick type (FQ) consists of BISGMA -phenyl]-propane), TEGDMA (Triethylene glycol dimethacrylate) and UDMA (urethane dimethacrylate) but UDMA is not used in the type with high flow (HF).The filler weight and volume percentage are 71% and 53%, respectively, in FQ composite resin; however, these measures are 68% and 49% in HF composite resin.As shown in 27The first generation of flowable composite resins was created by reducing the filler content of hybrid composite resins in order to decrease material viscosity.28There are three ways for increasing composite viscosity: increasing filler content, using irregular filler shapes, and incorporating glass fibers. Although no strong correlation has been shown between filler particle morphology and rheological properties, viscosity can be increased in the order of spheres, grains, plates and rods. Therefore, use of spherical filler shape, as they used in Estelite flowable composite resins, can increase filler content and also fracture resistance. In addition, round filler shape results in less friction because of interactions between filler particles or filler and matrix compared to irregular filler shapes used in most flowable composite resins. Adding nano-fillers to flowable composite resins increases composite resin viscosity because of increased filler surface area and also matrix- filler interaction or between filler particles; in addition, it improves the mechanical and flow characteristics.13 used wear resistance and flexural strength as two critical measurements for comparing flowable composite resins with universal composite resins as posterior restoration materials. Although wear resistance is one of the factors affecting the restoration durability, it will be better to consider other mechanical characteristics in future studies, which can influence the final decision on material selection. According to the results of this study and other similar studies,22, and among high flow ability and optimum mechanical properties like wear resistance, flowable composite resins can be suggested for use as a durable preventive restoration in permanent molars.Sumino et alOne of the limitations of this study was unavailability of three-body abrasion device in famous Iranian metallurgy schools, like Tehran, Elmosanat and Amirkabir Universities or their devices could not tolerate long period of wear tests which are proper for high wear cycles of dental restoration materials in the oral cavity. The high cost of wear test and the profilometer led to the withdrawal of SEM analysis. The profilometer analysis is reliable only for wear measurement; therefore, SEM analysis was not carried out because of financial limitations. It is suggested that proper three-body abrasive devices be designed for dental research. In addition, more financial support should be considered for research purposes so that researchers can carry out investigations with the use of more reliable and up-to-date devices with better financial support.It is logical to use some kind of flowable composite resins as pit and fissures sealant materials in preventive dentistry; these composite resins have better mechanical properties like higher wear resistance which lead to longer durability and reduce office and patient expenditure.We appreciate the Tribology Laboratory staff at Metallurgy School of Tehran University for their assistance in wear test and profilometer analysis.SA contributed to the study concept, study design, literature review, experiments, data analysis and manuscript preparation. SE contributed to the study concept, literature review and manuscript preparation. SH contributed to the literature review, study experiments, data analysis and manuscript preparation. All the authors have read and approved the final manuscript.The study was self-funded.The authors declare no competing interests with regards to the authorship and/or publication of this article.Not applicable.


Ischemic stroke is an uncommon cause of death among teenagers and young adults; however, the etiologies differ when compared to ischemic strokes in older individuals. Large-vessel atherosclerosis and small-vessel disease causing ischemic stroke are rare for the teenage population, while cervicocerebral arterial dissections account for up to 20% of ischemic strokes. Here, we present the case of a 16-year-old male who developed internal carotid artery dissection (ICAD) after a head injury and subsequently developed ischemic stroke and seizures. Ischemic stroke is a relatively uncommon cause of morbidity and mortality in teenagers and young adults, with an annual occurrence rate of 10.8 per 100,000 people aged 15-49 years and exponential risk dependent on age . ExtracrA 16-year-old male with no previous medical history experienced a transient loss of consciousness after two simultaneous head-to-head collisions during a high school football game. Upon regaining consciousness, the patient initially answered questions appropriately; however, he became combative and was intubated due to severe agitation and suspected seizure activity. The patient was transferred to an outside hospital and received computed tomography (CT) scans of the head and cervical spine, both of which reported no acute pathology. An attempt was made to extubate the patient; however, a neurological examination revealed 3/5 left-sided strength with spasticity. Sensation was intact bilaterally, and no carotid bruits were heard. Brain and cervical spine magnetic resonance imaging (MRI) revealed a right MCA infarct on the diffusion-weighted image and questionable right internal carotid artery (ICA) dissection  was performed and the presence of a mild encephalopathy with superimposed right temporal slowing was noted. No epileptiform activity was seen. The patient was started on hypertonic saline due to cerebral edema, valproic acid, and aspirin 325 mg. He was extubated one day after arrival at our facility. Serial head CT scans were performed and revealed progressive ischemic changes involving territories of the right MCA, anterior cerebral artery (ACA), anterior choroidal artery, and medial ventriculostriate perforator arteries and a stable 6 mm midline shift  showed significantly elevated velocity in the right MCA. However, hypertonic saline was appropriately tapered and significant improvement was noted on repeat TCD. The patient was transitioned from valproic acid to levetiracetam and discharged to inpatient rehab for continued care. At the time of discharge, a neurological examination revealed 0/5 strength in the left upper and lower extremities, with left pronator drift and upgoing left plantar reflex.A follow-up cerebral angiogram was performed four months after the initial injury, which revealed progressive segmental luminal irregularity of the right supraclinoid internal carotid artery extending into the right M1 segment, as well as globally diminished caliber of the right MCA territory branches. These findings were unchanged from a CT angiogram performed one month earlier Figure . At the This case involves a young patient with ischemic injury due to possible right ICA dissection involving the right cavernous and supraclinoid segments versus vasospasm. The involvement of multiple anterior circulation branches from the ICA, particularly the involvement of the anterior choroidal artery and the medial lenticulostriate perforator arteries, is suggestive of traumatic ICA dissection. Ischemic injury secondary to ICAD results from stenotic flow through a dissected vessel or embolic arterial occlusion secondary to thrombus formation. The majority of infarcts after ICAD occur at the site of the vascular injury . SeveralTranscranial Doppler has been used to demonstrate that hemodynamically significant vasospasm frequently occurs after traumatic brain injury (TBI), as shown by increased flow rates through the constricted vessels. In patients with severe blunt head injury, up to 40% experience MCA spasms, as demonstrated on TCD; flow rates reach a maximum at five to seven days after injury and usually resolve within 14 days . This reIn our case, the patient displayed transiently elevated velocity in the right MCA without signs of intracranial hemorrhage on imaging, consistent with post-traumatic vasospasm. However, it is unlikely that non-SAH-related vasospasm alone could account for the degree of MCA infarct and subsequent neurological impairment. Instead, post-traumatic vasospasm is likely a compounding secondary insult seen in traumatic ICAD resulting from the underlying brain injury.Traumatic brain injury in high school athletes is an increasingly prevalent and devastating cause of morbidity and mortality. Head injuries can lead to ischemic stroke secondary to internal carotid artery dissection. Further studies and evidence-based guidelines are needed to best prevent these potentially fatal injuries in high school sporting events.


In this case report, we present a unique case of idiopathic peroneal tenosynovitis in an otherwise healthy patient, presenting with a three-month history of pain over the lateral aspect of the right foot. Imaging revealed that fluid distention and synovial thickening distend the common peroneal tendon sheath and peroneus longus and brevis tendon sheaths. The patient was managed operatively with excision of the peroneus longus tendon, a side-to-side tenodesis, and Bröstrom-Gould lateral ankle ligament repair. Histologic examination was suggestive of a chronic inflammatory process possibly due to underlying autoimmune etiology. At three-month follow-up, the patient reported complete resolution of pain and is resuming normal activities without difficulty. The etiology of peroneal tenosynovitis stems from chronic or acute mechanical irritation, infections, and prior rheumatologic disorders. Histology often shows evidence of chronic inflammation -4. We prA 53-year-old female presented to clinic with pain over the lateral aspect of the right foot which began after ‘rolling’ her right ankle three months prior. She reported that two previous attempts of conservative management with a fracture boot for six weeks, which was subsequently repeated for three weeks, did not improve her pain. Multi-planar, multi-weighted, 3 Tesla (3T) magnetic resonance imaging (MRI) of the right ankle revealed the following conditions: 1) chondral thinning over the medial margin of the tibial-talar joint, with underlying bone marrow edema at the level of the medial talar dome, 2) marked fluid distension and synovial thickening with distension of the common peroneal tendon sheath into the peroneus brevis and peroneus longus sheaths, and 3) reactive subcortical bone marrow edema along the lateral wall of the calcaneus. The peroneal tendons demonstrated tearing and degenerative flattening  area as well as the retrofibular space to evaluate the peroneal tendons. Careful dissection was performed after elevating skin flaps to avoid damage to neurovascular structures. The superior peroneal retinaculum was incised, and a copious amount of yellow fluid egressed from the distended peroneal tendon sheath. Upon entering the peroneal tendon sheaths, a significant amount of brownish-gray synovial proliferation was noted throughout the retrofibular space. Several samples were taken from the peroneal tendon sheath synovium, peroneus brevis, and peroneus longus, and sent to pathology to determine the cause of this proliferation. The peroneus longus tendon was noted to be torn, with >80% of its length disrupted and degenerated. At that time, a decision was made to excise the peroneus longus tendon and perform a side-to-side tenodesis. A Broström-Gould lateral ankle ligament repair was also performed.At first follow-up, nine days postoperatively, the patient’s lateral ankle wound was healed and her pain was improving. She was referred for physical therapy but was unable to make the appointment due to personal issues. At three months postoperatively, the patient was called as she had missed her second follow-up due to continued personal issues. She declared that her pain prior to surgery had resolved completely and she was back to all of her activities without difficulty.Specimens from the peroneus brevis, peroneus longus, and peroneal tendon sheath synovium were evaluated by pathology. Tissue from all tendons demonstrated marked lymphocytic inflammation with chronic and acute inflammation and development of germinal centers observed within the synovium Figures -5.Peroneal tendonitis often stems from traumatic etiology or in the presence of predisposing anatomy, such as in patients with a large peroneal tubercle or low-lying muscle belly. In these situations, typical histology of uncomplicated tenosynovitis is progressive and involves three distinct grades. Grades I–III correspond to isolated synovial fibrous hypertrophy of the synovium, with later development of localized necrotic areas, and progressive development of empty spaces reminiscent to serous bursae, respectively -3.When history and physical examination do not point to a mechanical etiology for a patient’s pain, infectious or rheumatologic etiologies should be considered. Even then, the etiology of the tenosynovitis may be difficult to ascertain. Our case demonstrates the potential value of sending the excised portions of tenosynovium for histology during operative treatment of idiopathic peroneal tenosynovitis. In this case, the dense lymphocytic infiltrate found was suggestive of possible underlying rheumatologic disease . AlthougHistology of this patient’s idiopathic peroneal tenosynovitis was suggestive of undiagnosed autoimmune disease. Peroneal tenosynovitis has not been documented as an initial finding in undiagnosed immune disease, but similar histologic changes observed in some cases of carpal tunnel syndrome have been noted as initial signs of autoimmune disease. Surgical treatment of idiopathic tenosynovitis is an appropriate treatment choice due to the risk of rupture and progressive deterioration if left untreated.


However, the regenerated bone volume can vary and generally has a tendency to decrease after sinus operation. This article describes nongrafted maxillary sinus lift using a bioresorbable unsintered hydroxyapatite combined with poly A 60-year-old healthy female was referred to our department for dental implant therapy in the right posterior maxilla. Clinical examination revealed that the maxilla was edentulous from the right first premolar to the second molar region. Radiographically, atrophy of the maxillary alveolar ridge in the same tooth site was observed. Sinus membrane elevation and simultaneous implant placement were performed through the lateral approach. HA/PLLA mesh was utilized to maintain space under the elevated sinus membrane and as a fixation device to replace the bone window. Six months later, new bone was generated in the secluded space maintained under the elevated sinus membrane. When observed 42 months after the implant insertion, bone volume around the implant apex had increased in vertical direction under the HA/PLLA mesh plate device, and there was continuous bone formation in the sinus over time.This nongrafted sinus lift procedure using an HA/PLLA mesh device attained predictable bone formation. Stable membrane elevation by an HA/PLLA device might induce long-term, continuous bone formation in the sinus. Maxillary sinus lift is a bone augmentation procedure in the sinus that improves the alveolar crest height in atrophic posterior maxilla by forming new bone in the space created under the elevated sinus membrane. To date, numerous grafting materials have been used as a scaffold for new bone regeneration, including autogenous bone, bone graft substitutes, or their combination , 2. AutoRecent studies have shown that sinus lift by elevating the sinus membrane without grafting materials induces bone formation in the maxillary sinus –8. Nongrl-lactide (HA/PLLA) materials and dental implant placement in an atrophic posterior maxilla. In this case, continuous bone formation in the sinus was observed during the postoperative follow-up period of 3 years, and we show the sequential radiographic outcome of this procedure.This article describes a case of nongrafted maxillary sinus lift using a mesh plate device consisting of bioresorbable unsintered hydroxyapatite combined with poly A 60-year-old healthy female, who desired dental implant therapy in the right molar region of the maxilla, was referred to the Department of Oral and Maxillofacial Surgery. Clinical examination revealed an edentulous maxilla from the right first premolar to the second molar region. Panoramic radiography showed atrophy of the maxillary alveolar ridge in the same site Fig. , and theMaxillary sinus lift and simultaneous implant placement were implemented by sinus membrane elevation using an HA/PLLA mesh device without grafting materials. Using a piezoelectric device , osteotomy was performed in the lateral sinus wall of the right posterior maxilla Fig. . After tIn nongrafted sinus-lifting procedure, several devices such as titanium –14, hollIn conventional sinus lift with grafting materials, the materials are usually transplanted to the secluded space under the lifted sinus membrane covering the entire length of the implants , and in This nongrafted sinus-lifting procedure using an HA/PLLA mesh plate device helps to attain predictable bone formation. Stable membrane elevation by the HA/PLLA device for the long term could contribute to predictable bone formation in the sinus. The source of cell supply could possibly be the Schneiderian membrane, reflecting its osteogenic potential.Written informed consent was obtained from the patient for publication of this report and all accompanying images.


In this article, we briefly review molecular aspects of each component  of ADCs, and then mainly discuss traditional and new technologies of the conjugation and linker chemistries for successful construction of clinically effective ADCs. Current efforts in the conjugation and linker chemistries will provide greater insights into molecular design and strategies for clinically effective ADCs from medicinal chemistry and pharmacology standpoints. The development of site-specific conjugation methodologies for constructing homogeneous ADCs is an especially promising path to improving ADC design, which will open the way for novel cancer therapeutics.The antibody-drug conjugate (ADC), a humanized or human monoclonal antibody conjugated with highly cytotoxic small molecules (payloads) through chemical linkers, is a novel therapeutic format and has great potential to make a paradigm shift in cancer chemotherapy. This new antibody-based molecular platform enables selective delivery of a potent cytotoxic payload to target cancer cells, resulting in improved efficacy, reduced systemic toxicity, and preferable pharmacokinetics (PK)/pharmacodynamics (PD) and biodistribution compared to traditional chemotherapy. Boosted by the successes of FDA-approved Adcetris Over the past half century, cancer management has improved significantly along with the advancement of chemotherapy  in 2000 for CD33-positive acute myelogenous leukemia  in 2011 for CD30-positive relapsed or refractory Hodgkin’s lymphoma and systemic anaplastic large cell lymphoma  in 2013 for HER2-positive breast cancer  covalently conjugated through chemical linkers Fig. A. In modGiven the mechanism of action, the ideal antibody needs to have sufficient antigen affinity and specificity. However, antibodies with extremely high antigen affinity are known to lead to reduced efficiency of solid tumor penetration , auristatins (used in Adcetris®), and maytansinoids (used in Kadcyla®), new classes of highly potent antimitotic compounds have also been explored for ADC payloads: duocarmycins, pyrrolobenzodiazepine dimers (PBDs), amanitins, and tubulysin analogs are such examples   The linker needs to possess sufficient stability in plasma so that ADC molecules can circulate in the bloodstream and localize to the tumor site without premature cleavage. Instability of the linker causes premature liberation of the toxic payload and undesired damage to non-target healthy cells, which can lead to systemic toxicity and adverse effects. However, a clinical study revealed reverse correlation between linker stability of maytansinoid-based ADCs and adverse toxicity /pharmacodynamics (PD) and therapeutic window. To maximize these parameters, various types of linkers have been developed and evaluated Based on the above-mentioned criteria, tremendous effort has been put toward developing conjugation methods and ADC linker structures. Chemical conjugation and enzymatic conjugation are two methods for tethering the antibody and payload components that are currently in use. Linker structure is categorized into two major classes based on the payload release mechanism: cleavable or non-cleavable linker. Herein, we review modern conjugation methods and ADC linker technologies in detail.In ADC chemical conjugation, accessible amino acid residues on the surface of the antibody undergo a controlled reaction with a reaction handle installed on the linker. Depending on the chemical conjugation method selected, this process affords a mixture of ADC species with variable Drug-Antibody Ratios (DARs) and tethering sites. In general, a broad distribution of DAR can lead to reduced efficacy, and thus the distribution needs to be tightly controlled. High DAR can increase not only potency but also the risk of aggregation, clearance rate, and premature release of the toxic payload during circulation. This risk can be reduced by employing hydrophilic, sufficiently stable linkers. Overall, it is crucial to identify an optimal DAR value with a controlled distribution for each ADC that can maximize the balance of efficacy, tolerability, and cytotoxicity profiles.® and clinically tested ADCs, the lysine-based conjugation requires effort to develop reproducible manufacturing processes ensuring controlled DAR and distribution within a target range .Amide coupling is a major ADC conjugation method connecting a payload and solvent accessible lysine residues on the antibody using linkers containing activated carboxylic acid esters Fig. . Amide c® and many other ADCs in clinical trials. However, this modality still has room for improvement to achieve better DAR and heterogeneity control: the above-mentioned simple cysteine conjugation can give a DAR distribution raging from 0 and 8. Junutula and co-workers introduced two new cysteine residues (one per heavy chain) for selective antibody attachment propane-based core  comparable to that of the parent trastuzumab. Another advantage of this method is that the resulting aryl-cysteine conjugates are stable towards acids, bases, oxidants, and externally added thiols. While unique and intriguing, this method needs substantial modification or improvement of several critical factors for the future clinical application . Despite current limitations, further work will provide researchers with profound insights into cysteine-based conjugation chemistry and rational design of reagents for preparing ADCs that could have not been constructed with traditional methods.Recently, Buchwald and co-workers developed a rapid, highly selective cysteine conjugation using aryl palladium complexes carbonyl)-L-lysine  where Several enzymes have been used for conjugating the native or genetically engineered antibody with the payload or for installing unique reaction handles on the antibody scaffold for the following chemical conjugation. These enzymes modify the antibody in a site- or amino acid sequence-specific manner. Furthermore, the reaction sites in native mAbs or handles that are genetically introduced are designed to specifically react with counterpart functional groups. Thus, (chemo)enzymatic approaches generally allow for site-specific conjugation leading to tightly controlled DARs.Staphylococcus aureus recognizes the LPXTG (X: any amino acid) motif, cleaves the threonine-glycine (T-G) bond, and attaches an oligoglycine (oligo-G)-containing molecule. Various cargo can be fused to the oligo-G for sortase A-mediated conjugation: peptides, proteins, nucleic acids, and so on  derived from mAbs  within deglycosylated antibodies, resulting in ADCs with a defined DAR of 2 (one conjugation site per heavy chain)  and α-2,6-sialyltransferase  . The azide handles were used for a strain-promoted click reaction with payloads, resulting in stable and homogeneous ADCs with tightly controlled DARs (predominant at 2 in most cases). The biggest advantage of this technology is that it gives consistent results regardless of the heterogeneity of the N-Glycan forms, meaning that it can be used for any IgG isotypes with various N-glycosylation profiles.Asn297 (N297) within the Fc domain and the lT) Fig. . These tA major class of ADC linkers is the cleavable linker Fig. . Cleavab® , resulting in a slow release of the toxic payload  and lysosomes (pH about 4.8) Fig. A. The chp-aminobenzyloxycarbonyl  are the most successful cleavable linkers for ADCs   and fast linker cleavage and release of free payload molecules in lysosomes. Interestingly, each conjugate released a free payload at different rates, depending on the substituent group proximal to the pyrophosphate moiety. This result suggests that the rate of release could be fine-tuned by further structural modifications. In addition, one of the ADCs containing fluticasone propionate exerted remarkable potency (EC50: 0.37 nmol/L) in CD70-positive 786-O cells, comparable to free fluticasone propionate (EC50: 0.25 nmol/L). These results demonstrate the potential of the pyrophosphate diester linker for the future development of therapeutically practical ADCs.Recently, Garbaccio and co-workers developed a novel cleavable linker with a pyrophosphate diester structure Fig. D Kern e. This an®)  often negatively impacts ADC efficacy and therapeutic window, which often leads to difficulty or limitation in the optimization for clinical application and eventual failure in clinical trials. To overcome these problems, current efforts are directed toward developing novel stable linkers (with or without a payload release mechanism) and site-specific conjugation methods enabling construction of homogeneous ADCs. Further investigations along this line will provide greater insights and sophisticated strategies from medicinal chemistry and pharmacology standpoints, leading to innovative cancer therapeutics in the future.In this article, we have reviewed the concept and clinical potential of ADCs and various conjugation/linker strategies for constructing this new class of molecules Table . Compare