There are inherent structural and functional differences in the central nervous systems (CNS) of females and males. It has been gradually established that these sex-specific differences are due to a spectrum of genetic, epigenetic, and hormonal factors which actively contribute to the differential incidences, disease courses, and even outcomes of CNS diseases between sexes. Microglia, as principle resident macrophages in the CNS, play a crucial role in both CNS physiology and pathology. However, sex differences of microglia have been relatively unexplored until recently. Emerging data has convincingly demonstrated the existence of sex-dependent structural and functional differences of rodent microglia, consequently changing our current understanding of these versatile cells. In this review, we attempt to comprehensively outline the current advances revealing microglial sex differences in rodent and their potential implications for specific CNS diseases with a stark sex difference. A detailed understanding of molecular processes underlying microglial sex differences is of major importance in design of translational sex- and microglia-specific therapeutic approaches. Every cell has a sex . NeuronsMicroglia can be reprogrammed during early life and thus exert crucial effects on behavior and disease in later life –13. We rIn this review manuscript, we first summarize recent novel evidence showing the sex differences of rodent microglia. We then discuss potential differences of microglial numbers and phenotypes between sexes. More importantly, microglial endogenous functionality and response to exogenous stimuli also differ between males and females. Epigenetic mechanisms including DNA methylation, histone modifications, and long non-coding RNAs that may partly explain these sex differences of rodent microglia are discussed.First described a century ago, microglia are specialized resident macrophages within the central nervous system (CNS) –22. The Reports that describe the substantial plasticity and complexity of microglia through a spatiotemporal manner are readily accumulating –33. TheyIt is gratifying that most of Hortega’s original postulates of microglial biology have now been proven quite correct, despite that this has required the most recent technical innovations to unequivocally prove his foresight. The most recent findings of spatiotemporal differences between resident microglia subpopulations open up a new era of scientific discovery in which the individual contributions of microglia subsets in both driving or protecting from disease will be possible to define.Sex should be considered as a biological variable when designing both preclinical experiments and clinical trials , 43. IndCSF1R)-related leukoencephalopathy, mainly caused by CSF1R gene mutations and regarded as the most common type of adult-onset leukoencephalopathy, currently without a cure, typically presents with progressive neuropsychiatric and motor symptoms [CSF1R-related leukoencephalopathy is considered as a primary CNS microgliopathy with dystrophic microglia playing a pivotal role in disease pathogenesis [CSF1R-related leukoencephalopathy in prevalence and disease duration, male patients develop disease significantly later than do females [Colony-stimulating factor 1 receptor  are significantly more numerous in female rats than in males [During normal neurodevelopment, microglia undergo sex-specific and distinct maturation processes over time . There ain males . In genein males . In resein males .+-stained microglia on P2 [Around the time of birth, a testosterone surge has been noted in male rodents that sensitively influences the number and function of microglia in the developing brain, since microglia expressed related receptors for steroid hormones , 59. In ia on P2 .The sex differences of microglia described above could be mediated by sex hormones, as evidenced by an increased number of amoeboid microglia in the POA in females treated neonatally with estradiol , 58. Fur+ microglial cell density is significantly higher in the hippocampus, cortex, and amygdala of adult male mice when compared with adult female mice [As measured using deep single-cell RNA sequencing across different developmental periods and brain regions, adult microglia do not seem as complex and heterogeneous as do postnatal microglia . Nonetheale mice . Microglale mice . In thisale mice . It is cale mice , 24, 61.We can conclude that microglial sex differences in both space and time are significant in developmental processes and that greater understanding of the underlying molecular mechanisms and environmental cues involved could be vital to the design of tailored therapies.Atg5 siRNA inhibited autophagy and aggravated proinflammatory polarization [Despite the presence of conflicting evidence, differences between rodent male and female comprehensive microglial functionality throughout the life span have also been recently discerned Table , indicatrization . In addirization . Sex difMale and female microglia have distinct fundamental endogenous behaviors such as antigen presentation. Some microglial sex differences are noted at both RNA and protein levels with few differentially expressed genes and proteins overlapping . Male miRadiotherapy is an effective tool in the treatment of high-grade brain tumors, but it is associated with adverse side-effects, where the long-term, so-called late effects are more pronounced in children , 74. One+ channel (Kcna3) and Kv current were also higher in male P21 microglia than in females following inflammatory stimulation, while unstimulated microglia had similar levels between males and females [Either acute or chronic behavioral stress has distinct direct effects on corticolimbic microglial morphology and immune factor transcriptional expression, such as of CD40, CX3CR1, and CD200R in a number of brain regions in a microglial sex-specific manner , 66. In  females . It has  females . OverallSex differences in brain innate immune responses to neonatal ischemia have been reported in P12 mice, with higher microglia immunoreactivity, greater proinflammatory gene expression, and increased myeloid cells being noted in male mice . In addiMale and female microglia may have distinct mechanisms to resolve an inflammatory insult. Specifically, female rat neonatal microglia had both less basal and stimulated microglial migration than did male microglia . During A series of factors such as different ages, species, brain regions, and methods in these studies may account for this discrepancy . In reseMicrochimerism is defined as the phenomenon of two genetically distinct cell populations in an individual, with male microchimerism occurring more frequently than in the female brain . Fetal mAll these observed functional differences may predispose as yet underestimated but marked sex-dependent microglial activation patterns and signaling cascades in the injured CNS , 92. EmeMost of the evidence presented is derived from preclinical studies, showing dynamic sex differences of microglia. Understanding how sex differences of microglia contribute to the occurrence and progression of human CNS disorders may explain sex differences in CNS disease susceptibility and provide new optimism for developing sex-specific treatments.Microglia can be pre-conditioned through epigenetic-driven innate immune memory that persists for several months , 96. EpiDNA methylation is an epigenetic mechanism that occurs by the addition of methyl groups to DNA, modifying genetic functions without changing the sequence . From a Cx3cr1CreHdac1fl/flHdac2fl/fl mice being harmful for microglial development by inducing apoptosis and reducing survival [Histone modifications are epigenetic regulators that control chromatin structure and gene expression . Histonesurvival , 104. Hosurvival , 104. Whsurvival , regionasurvival .MicroRNAs are small non-coding RNA molecules that act as post-transcriptional negative regulators of gene expression. Different expressions of isolated microglial microRNAs in the adult mice brain between male and female at baseline have also been uncovered using microRNA sequencing, which was also validated using qPCR . SelectiCollectively, these data imply that epigenetic mechanisms such as DNA methylation, histone modifications, and microRNAs impact an array of transcriptional responses and, at least in part, represent a potential mechanism that might explain microglial sex-related functional differences. We are optimistic that future research regarding epigenetic control of male and female microglia will bear exciting novel discoveries to better understand the sex differences of microglia.Sex differences of microglia exist among diverse regions with respect to both CNS physiology and pathology. Sexual microglial dimorphism may be in part responsible for sex differences in the incidence and pathology of a variety of neurological diseases. Males may be more vulnerable to neurological insults during early development in part as a result of having more highly activated microglia in the developing brain compared to females. In contrast, increased activation of microglia in females during adulthood may contribute to their increased susceptibility to several inflammatory brain diseases that occur late in life. Given our increasing understanding of these fascinating cells in some degree of both targets and drivers of sex differentiation , future


Clinical Psychological Reviews, 42, 72–82) might indicate heterogeneity of underlying neurobiological mechanisms among patients, presumably leading to high variation in treatment benefit. Transforming insights from cognitive neuroscience into applicable clinical heuristics to categorise patients based on their underlying biomarker may support individualised treatment selection in psychiatry. We review literature on the three anxiety-related mechanisms and present a mechanistic model that may serve as a rational for pathology-based diagnostic and biomarker-guided treatment selection in psychiatry.Increased amygdala responsiveness is the hallmark of fear and a characteristic across patients with anxiety disorders. The amygdala is embedded in a complex regulatory circuit. Multiple different mechanisms may elevate amygdala responsiveness and lead to the occurrence of an anxiety disorder. While top-down control by the prefrontal cortex (PFC) downregulates amygdala responses, the locus coeruleus (LC) drives up amygdala activation via noradrenergic projections. This indicates that the same fearful phenotype may result from different neural mechanisms. We propose a mechanistic model that defines three different neural biomarkers causing amygdala hyper-responsiveness in patients with anxiety disorders: (a) inherent amygdala hypersensitivity, (b) low prefrontal control and (c) high LC drive. First-line treatment for anxiety disorders is exposure-based cognitive behavioural therapy, which strengthens PFC recruitment during emotion regulation and thus targets low-prefrontal control. A treatment response rate around 50% (Loerinc et al., 2015,  Anxiety disorders are among the most common mental health problems. In the United States for instance, the lifetime prevalence to suffer from any anxiety disorder is 33.7%   revealed successful symptom reduction after regulating noradrenaline imbalances with α1-receptor antagonists or α2A-receptor agonists  suggested two distinct systems, a ventral and a dorsal one. Ventral regions of the anterior cingulate cortex (ACC) and PFC are involved in identification, evaluation of significance and production of affective states, while dorsal regions support effortful conscious emotion regulation  that might upregulate amygdala responsiveness. The amygdala-biomarker is defined by disruption of GABA-based inhibitory processes within the amygdala. The PFC-biomarker is characterised by reduced recruitment of inhibitory top-down projections. The LC-biomarker is based on increased noradrenaline release from the LC, which drives up amygdala activation by disrupting GABAergic inhibition and intensifies emotion processing by amplifying attentional processes. Yet, those three biomarkers form an amygdala-centred network and manifestations in one biomarker might affect the other mechanisms driving the network .Fig. 1.We propose inherent amygdala hypersensitivity or alterations in amygdala-centred regulatory circuits  all lead to the same fearful phenotype. Although the three mechanisms might be interconnected, and targeting one mechanism would affect amygdala responsiveness either way, we propose that individualised treatment selection that specifically targets the causative neural biomarker in a given patient would increase treatment efficiency. Targeting the causative biomarker would treat an anxiety disorder at its core mechanism and would allow patients to be allocated to a treatment according to the biological origin of their anxiety. This might reduce expensive and time-consuming detours in treatment procedures. Importantly, this section aims to give an outlook on the potential impact of biomarker characterisation on clinical practise. Deriving treatment guidelines from biomarkers is still a matter of research and this work intends to stimulate future studies on biomarkers with a focus on treatment implications.In this model, we assume that patients with amygdala hypersensitivity experience symptoms of anxiety despite being capable of appropriate cognitive emotion regulation strategies. This might indicate that CBT does not target amygdala hypersensitivity. As discussed above, disruption of GABAergic inhibition might be the underlying neurobiological mechanism of amygdala hypersensitivity. To specifically target disruption of GABAergic inhibition, treatment with benzodiazepines might be indicated. Benzodiazepines enhance GABAergic inhibition and have been demonstrated as effective treatment, preferably as short-term treatment for patients with anxiety symptoms that have not responded to other treatments  amygdala sensitivity, (b) low PFC control and (c) high LC drive. An emotion regulation task could be applied to monitor activation in the PFC during regulatory attempts  the model rather supports an intervention that downregulates LC drive. However, it is unknown if decreased PFC activation causes increased noradrenaline levels. The existence of a potential association between decreased PFC control and increased noradrenaline levels would need to be clarified in order to establish a reliable noradrenaline-based predictor for the CBT outcome. Furthermore, the LC might not be a homogenous modulator of PFC activation but might have a stronger effect on medial as compared to other frontal areas (Chandler et al., The proposed model is highly simplified and only considers three biomarkers as the origin of increased amygdala response. Animal studies attribute a crucial role to dopamine and serotonin regarding extinction learning, which potentially might have predictive value as well (Singewald, Schmuckermair, Whittle, Holmes, & Ressler,


Significance: It has been reported that children with attention-deficit hyperactivity disorder (ADHD) have impairment in the recognition of angry but not of happy facial expressions, and they show atypical cortical activation patterns in response to facial expressions. However, little is known about neural mechanisms underlying the impaired recognition of facial expressions in school-aged children with ADHD and the effects of acute medication on their processing of facial expressions.Aim: We aimed to investigate the possibility that acute administration of methylphenidate (MPH) affects processing of facial expressions in ADHD children.Approach: We measured the hemodynamic changes in the bilateral temporo-occipital areas of ADHD children observing the happy and angry facial expressions before and 1.5 h after MPH or placebo administration in a randomized, double-blind, placebo-controlled, crossover design study.Results: We found that, regardless of medication, happy expressions induced increased oxyhemoglobin (oxy-Hb) responses in the right inferior occipital region but not in the superior temporal region. For angry expressions, oxy-Hb responses increased after MPH administration, but not after placebo administration, in the left inferior occipital area, whereas there was no significant activation before MPH administration.Conclusions: Our results suggest that (1) ADHD children consistently recruit the right inferior occipital regions to process happy expressions and (2) MPH administration to ADHD children enhances cortical activation in the left inferior occipital regions when they process angry expressions. Faces convey a wealth of information about a person’s emotional state,,,It has been reported that the behavioral and cognitive characteristics of ADHD are partly related to dopamine (DA) and noradrenaline (NA) dysfunctionsGiven that MPH improves neurocognitive processing during go/no-go tasks  to measure cortical hemodynamic responses while ADHD children observed facial expressions in a randomized, double-blind, placebo-controlled, crossover design study. We compared hemodynamic responses in ADHD children’s temporal and occipital areas during the presentation of angry and happy facial expressions both before and after MPH or a placebo administration. Considering previous evidence that MPH administration improves recognition of angry expressions,22.1The final sample of participants for this study consisted of 19 clinically referred right-handed Japanese children , who were diagnosed as ADHD based on the DSM-5All participants and their parents gave oral consent to participate in the study and written informed consent was obtained from the parents of all participants. The study was approved by the Ethics Committees of Jichi Medical University Hospital. The experiments were conducted in accordance with the latest version of the Declaration of Helsinki.2.2,The same stimuli were used as in previous fNIRS studies.There were two test conditions: the happy expression condition and the angry expression condition. For both the happy and angry conditions, one of the five females was chosen randomly for each trial. The sequence of stimulus presentation was identical to that in the previous study.2.3Each participant was tested while sitting in a chair and looking at a computer screen 2.4The effects of MPH were examined in a randomized, double-blind, placebo-controlled, crossover study while participants observed happy and angry facial expressions . We inveOn each day, ADHD participants underwent two sessions, one before administration of MPH or placebo and the other at 1.5 h after administration. Before each premedication session, all participants underwent an MPH washout period of 4 days. According to the previous study,After measurement of the first session, either MPH (OROS-MPH or Concerta) or a placebo was administered orally. Specific acute doses were the same as the participants’ daily doses, as shown in 2.5,We used the multichannel fNIRS system ETG-4000  with two wavelengths of near-infrared light (695 and 830 nm) and two sets of fNIRS probes  for each probe.We set the fNIRS probes at the bilateral temporal areas because these regions have been reported as important regions for face processing  in real-world space using a 3D digitizer . To identify the spatial positions of measurement channels, we adopted the probabilistic registration method2.6Before analyzing the data, we evaluated the validity of each trial. We excluded a trial from analysis if (a) participants did not look at the face stimuli or (b) body movements were detected based on the experimenter’s visual examination during measurements. In the current study, no channels were rejected for either happy expression or angry expression conditions.We analyzed oxy-Hb and deoxy-Hb concentrations for further analysis. Individual time-course data for the oxy-Hb and deoxy-Hb changes of each channel were preprocessed with a first-degree polynomial fitting and bandpass filter using cut-off frequencies of 0.01 to 0.8 Hz to remove baseline drift or noise from heartbeat pulsations. Based on the preprocessed time series data, channel-wise and participant-wise contrasts were obtained for each channel by calculating the intertrial mean of differences between the oxy-Hb or deoxy-Hb changes for tests (from 5 to 15 s after face stimulus onset) and baseline (3 s before face stimulus onset). We removed the trials if sudden, obvious, and sharp changes were detected in the time courses of oxy-Hb changes based on independent visual examination.2.7We performed statistical analyses for the oxy-Hb and deoxy-Hb signals of each channel. We calculated the following contrasts: (1) averaged premedication contrast: averaged activation between preplacebo and pre-MPH versus baseline, (2) postmedication contrasts: face stimuli versus baseline activations for postplacebo and post-MPH, (3) intramedication contrast: difference between post- and premedication activations for each medication , and (4) intermedication contrast: difference between intra-MPH and intraplacebo contrasts . For all contrasts, we performed two-tailed one-sample 3We obtained hemodynamic responses from 19 ADHD children who observed face stimuli for more than three trials for both happy and angry expression conditions. The mean number of trials was 5.05 (3.1Comparison of averaged oxy-Hb concentrations between preplacebo/pre-MPH and a baseline of zero (averaged premedication contrast) revealed that happy expressions induced significant increases of oxy-Hb concentration in the right channel 4  responses compared with baseline in the right inferior occipital area before and after administration of either a placebo or MPH. On the other hand, angry facial expressions induced no significant increases before MPH administration, whereas increased oxy-Hb responses occurred in the left inferior occipital area after MPH administration. This pattern of brain activation was not found for placebo administration. Importantly, we found that the MPH-induced activation was significantly higher than the placebo-induced activation in the left inferior occipital area in response to angry facial expressions but not to happy facial expressions.We used the same stimuli and compatible procedures as a previous study that investigated the perception of angry and happy facial expressions in ADHD children,,,–The results showing a significant activation for happy expressions regardless of medication are consistent with previous behavioral findings that ADHD children show comparable recognition performance for happy expressions relative to TD children.,,–,,The results we obtained from the activation levels of each channel may provide new insights into the neural processing of facial expressions in ADHD children. In the current study, ADHD children showed significant increases of oxy-Hb signal for happy facial expressions at the channels located in the inferior occipital region of the right hemisphere (Brodmann area (BA) 19: right IOG rather than the superior temporal region. Considering a former study showing that the face area at the IOG [occipital face area (OFA)] is located in BA 18 or 19,A previous finding showing a strong functional connectivity between the bilateral OFAs and the right STS,The significant increase in oxy-Hb signals with angry expressions induced by MPH administration is probably related to acute modulation of the DA system. Previous studies have shown that the DA system is important for recognition of angry expressions.,,In the present study, we found increased oxy-Hb responses in the region around the dorsolateral prefrontal cortex (DLPFC) and premotor cortex only for angry expressions before medication. This pattern of activation is consistent with previous findings that ADHD children exhibit greater activation in the DLPFC for angry expressions compared with TD children,,We found that, during passive observation of happy expressions, a slightly broader area of the right inferior occipital region activated after placebo administration  compared with before placebo administration (right channels 4 and 8) in oxy-Hb signals. This pattern was also found in deoxy-Hb signals: no channel activated before placebo administration, while the left channel 18 activated after placebo administration. Previous EEG studies with psychostimulants,As opposed to oxy-Hb signals, we did not find significant changes in deoxy-Hb signals even for happy expressions in occipital temporal areas across sessions after multiplicity correction (some channels showed significant decreases before multiple correction). These results suggest that changes in deoxy-Hb signals would be a less sensitive indicator of cortical processing of facial expressions than changes in oxy-Hb signals. Our results are consistent with previous findings that the signal amplitude of oxy-Hb is higher than that of deoxy-Hb–With the exception of the right channel 19 for the angry expressions in a comparison between pre-MPH and post-MPH administration, most channels showing significant increases in oxy-Hb signals did not show significant decreases in deoxy-Hb signals. Although increases in oxy-Hb signals are considered to be accompanied by decreases in deoxy-Hb signals with regional brain activation, deoxy-Hb signals do not necessarily show this pattern of changes.We will also discuss a few limitations of the current study. First, we could not provide evidence for how different regions of bilateral temporal areas contribute to the processing of facial expressions in TD children because we did not measure the brain activity of TD children for comparison. Second, we included ADHD children with and without comorbid autism spectrum disorders (ASD). In this study, participants included 13 ADHD children without comorbid ASD and 6 ADHD children with it. A recent fNIRS study implies that ADHD with ASD is characterized by a different neurofunctional pathology than that without ASD.To investigate the possible effect of ASD comorbidity, supplemental analyses were performed on the oxy-Hb data of ADHD children without comorbid ASD (5In conclusion, the current fNIRS study investigating the possibility that acute administration of MPH affects the cortical processing of facial expressions in ADHD children revealed different modulations in cortical activation patterns in response to the presentation of angry and happy expressions before and after MPH administration. We revealed that ADHD children show increased activation in the right inferior occipital region for happy expressions regardless of MPH or a placebo administration. In contrast, for angry expressions, significant activation was found in the left inferior occipital area after MPH administration but not before MPH administration. Importantly, we found significant MPH-induced, but not placebo-induced, increases in hemodynamic response for angry expressions in the left inferior occipital region, suggesting that MPH promotes the processing of physical forms or facial parts, but not valence information, of angry facial expressions.


Coronary subclavian steal syndrome (CSSS) is one of the rare complications of coronary artery bypass graft surgery (CABG). This phenomenon is a potential complication after left internal mammary artery (LIMA) to left anterior descending artery (LAD) CABG. A proximal stenosis of the left subclavian artery (SA) could cause retrograde flow from LIMA to left SA, which characterizes the mechanism of CSSS. We describe a unique case of recurrent CSSS in a 64-year-old female who presented with one month of exertional dyspnea and acute onset chest pain. She had an extensive coronary artery disease history with CABG 15 years prior to presentation and CSSS treated with left SA stent placement nine years later. She also underwent percutaneous intervention with stents placed in the saphenous vein graft. Although electrocardiogram, cardiac enzymes, and stress test did not show any evidence of acute ischemic changes, perfusion scan detected large areas of partially reversible ischemia. Cardiac catheterization was performed, which showed in-stent restenosis of the left SA and retrograde flow from the LIMA to the left SA indicative of recurrence of CSSS. Left SA arteriogram confirmed in-stent restenosis of the left SA, which was treated with balloon angioplasty and stent placement. Left internal mammary artery (LIMA) to left anterior descending artery (LAD) coronary artery bypass graft surgery (CABG) is a well-established procedure and has been proven to be beneficial. One rare complication of this procedure is an underdiagnosed phenomenon known as coronary subclavian steal syndrome (CSSS). This happens when there is a substantial occlusion of the left subclavian artery (SA) proximal to the ostia of the LIMA, causing blood to backflow from the LIMA to the left SA to maintain left upper extremity perfusion, especially at times of exertion . If leftA 64-year-old female with a past medical history of coronary artery disease, CABG, heart failure with reduced ejection fraction, diabetes mellitus, peripheral arterial disease, and hyperlipidemia, and a significant smoking history presented to the emergency department with exertional dyspnea worsening over the past one month and substernal chest pressure developing acutely on the day of presentation.The patient had an extensive coronary artery disease history, which included quadruple coronary artery bypass graft surgery with saphenous vein graft (SVG) to right coronary artery (RCA), SVG to the first diagonal artery (SVG-D1), and LIMA-to-LAD T-graft  to the posterior lateral/left circumflex artery 15 years ago.. The SVG was previously stented twice due to stenosis. She also had a history of CSSS with retrograde flow from LIMA to left SA nine years after CABG, which was treated with placement of a bare metal stent.On arrival to the ED, electrocardiogram (EKG) showed atypical right bundle branch block (RBBB) and nonspecific T-wave abnormalities in the anterior leads with normal troponin T <0.01 ng/mL) and mildly elevated proBNP ([pro B-type natriuretic peptide] 531 pg/mL)  and peripheral stenting, which are considered firstline treatments compared to the more invasive surgical bypass approach. Despite carrying a shorter hospital stay and less morbidity, PTA has been associated with increased incidence of restenosis and the need for repeat procedure in as many as 28.5% of the cases within a five-year follow-up period . RestenoSurgical bypass approach is generally reserved for patients with a totally occluded SA, when the complete occlusion is near the ostium of the vertebral artery, the length of the lesion is >5 cm, and concomitant brachiocephalic and coronary artery disease is present ,10. DespThe patient presented in this case had a recurrence of CSSS after in-stent restenosis of a previously placed subclavian stent. The patient’s risk factors, including history of peripheral arterial disease, smoking history, and diabetes mellitus, are among the contributing factors resulting in the recurrence of this phenomenon. Reduction of risk factors, better control of comorbid conditions, and routine follow-up can help prevent further episodes and prolong survival of such patients.CSSS is a rare complication of CABG, which is mostly seen in patients with significant coronary artery disease, peripheral vascular disease, and multiple risk factors contributing to these conditions. It can recur especially in instances of poor medical follow-up and inadequate risk factor control. Routine follow-up of these patients, elimination of modifiable risk factors, and counselling on lifestyle modification and medical adherence are important in improving morbidity and mortality.


The relevance of clinical data included in blunt trauma referrals for abdominal computed tomography (CT) is not known.To analyse the clinical details provided on free-text request forms for abdominal CT following blunt trauma and assess their association with imaging evidence of intra-abdominal injury.A single-institution, retrospective study of abdominal CT scans was performed for blunt trauma between 01 January and 31 March 2018. Computed tomography request forms were reviewed with their corresponding CT images. Clinical details provided and scan findings were captured systematically. The relationship between individual clinical features and CT evidence of abdominal injury was tested using one-way cross tabulation and Fisher’s exact test.p = 0.05), macroscopic haematuria (p < 0.01), pelvic fracture or hip dislocation (p = 0.04) and positive focused assessment with sonography in trauma (p < 0.01) demonstrated an associated trend with abdominal injury.One hundred thirty-nine studies met inclusion criteria. A wide range of clinical details was communicated. Only clinical abdominal examination findings (Key abdominal examination and basic imaging findings remain essential clinical details for the appropriate evaluation of CT abdomen requests in the setting of blunt trauma. Methods to improve consistent communication of relevant clinical details are likely to be of value. In neurologically intact, blunt trauma patients, trauma surgeons miss almost half of all abdominal injuries prior to imaging.4 Furthermore, missed injuries are more frequent in severe trauma, whilst in patients with decreased level of consciousness, injuries may be occult.5 Computed tomography (CT) has thus emerged as a definitive investigation for blunt abdominal injuries. However, there are concerns about its overutilisation, thereby exposing patients to unnecessary ionising radiation and inflating healthcare costs.7Approximately 15% of patients admitted in level-1 trauma centres have abdominal injuries.11 Nonetheless, most guidelines recommend whole-body CT for major blunt trauma in adult patients Injury Severity Score > 15.15 However, the National Institute for Health and Care Excellence (NICE) in the UK acknowledges low-quality observational studies that inform such guidelines. Additionally, although various clinical decision tools have been developed in an attempt to identify patients at a very low risk of abdominal injury, and thus not warranting further investigation, uptake of such guidelines has been very limited.18South Africa has no local guidelines informing patient selection for CT abdomen in the setting of blunt trauma. International studies in this domain so far have been confounded by wide disparity in study design and terminology.19 To this end, referring clinicians are obliged to provide radiologists with sufficient clinical information to assess the merits of each investigation.Justification is the decision-making process whereby the perceived benefits and potential risks of an examination are considered. Radiologists are responsible for the justification of medical exposure to ionising radiation, including trauma-related CT scans.Many radiology departments utilise free-text referrals to convey information from clinician to radiologist. This communication is integral for optimising patient care and healthcare resources by ensuring that every scan is warranted, appropriately performed and reported.20 The Royal College of Radiologists suggests that clinical information might include medical symptoms or signs pointing to a particular diagnosis or range of diagnoses. The radiologist reporting the examination should understand the ‘explicit and implied information’ contained in the clinical details, appreciating their relevance and diagnostic importance when interpreting the imaging study.21 The quality of clinical detail on the referral should thus enhance both patient selection and the reporting of studies.22 However, a key challenge confronting the radiologist contemplating CT requests for trauma patients is that the value of any specific clinical detail provided in predicting abdominal injury is unknown to both referring clinician and radiologist.The American College of Radiology stipulates that referrals should include relevant clinical information, a working diagnosis, pertinent signs and symptoms, as well as a specific clinical question.Without insights into the association between request content and CT findings, the free text request is potentially arbitrary. Establishing a link between clinical request and CT findings would enhance the justification process.We, therefore, aimed to describe the specific clinical details that clinicians elect to communicate and assess whether there is any association with imaging evidence of abdominal injury.This was a retrospective analysis of the free-text request forms and corresponding images of all abdominal CT scans performed for blunt trauma from 01 January 2018 through 31 March 2018 at Tygerberg Hospital (TBH). Tygerberg Hospital is a 1386-bed tertiary-level, public sector facility in Cape Town, South Africa. It is the main teaching hospital of the Faculty of Medicine and Health Sciences of Stellenbosch University and has a level-1 equivalent trauma unit, which manages approximately 24 000 cases annually. Tygerberg Hospital has a digital, filmless and paperless imaging environment, in which all examinations are requested electronically. The electronic workflow requires formal approval of the radiologist for all imaging investigations except plain radiographs, and precludes scheduling of special examinations prior to the radiologist’s justification.A systematic search of institutional radiology information system (RIS) was undertaken for initial abdominal CT scans of all adult patients (aged > 18 years) investigated for blunt trauma during the review period. Studies were excluded if CT scans were performed following laparotomy, as repeat scans, or without intravenous contrast.All clinical data included on the free-text electronic CT requests were systematically captured on a customised Microsoft Excel spreadsheet and stratified by patient demographics, clinical history, vital signs and haemodynamic status, abdominal and extra-abdominal examination findings, side-room investigations, laboratory test results, and baseline imaging features.23 A positive abdominal examination included any specification of abdominal bruising or abrasions, abdominal pain, tenderness or distension, low back pain, macroscopic haematuria or bruised chest. A positive extra-abdominal examination included specification of suspected injury to the head, cervical spine, thorax, thoracolumbar spine, pelvic fracture or hip dislocation, or long bone fractures.Definitions for positive abdominal and extra-abdominal examination findings were adapted from previous studies evaluating abdominal examination in blunt trauma.24 Extra-abdominal injuries were also captured (All CT scans were re-reported by the lead investigator (K.B.C.), a radiology registrar with 4 years of experience. Any discrepancies with the final radiology report were resolved by consensus in consultation with the same consultant radiologist who authorised the report. Computed tomography findings were stratified by abdominal organ, utilising the respective American Association for the Surgery of Trauma (AAST) classifications for solid organ injury.captured .Relationships between variables on electronic request and CT diagnosis of abdominal injury were tested using cross tabulation and Fisher’s exact test. Age differences were tested using one-way analysis of variance.This was a retrospective study. Confidentiality was maintained at all times. The study was approved by the Stellenbosch Research Ethics Committee (Reference No. S18/07/142).n = 139), with a mean age of 37 years  were included in the analysis. In most patients , the abdominal study was performed in conjunction with CT of other anatomical regions; in 28 patients (20%) it was a part of whole-body CT and in 25 (18%), CT was limited to the abdomen.One hundred thirty-nine patients  provided at least one abdominal  or extra-abdominal  clinical examination finding; 134 (96%) included a detail on clinical history; 70 (50%) reported side-room investigations; 45 (32%) reported baseline imaging results and 14 (10%) gave laboratory findings. No referral reflected detail in all categories.Request form information is presented in n = 132; 95%) was specified in the majority of cases, the Glasgow Coma Scale or mental status  was reported in just over two-thirds of patients, and microscopic haematuria  in approximately half the referrals. Of note, abdominal examination was deemed ‘unreliable’ in almost one-fifth of cases  because of the patient’s decreased level of consciousness. Almost one-quarter  recorded vital signs or haemodynamic status, and less than one-fifth referred to focused assessment with sonography in trauma .Mechanism of injury , most of whom had solid organ injury . There was no AAST grade 5 injury. There were six grade 4 (4%) and 35 (25%) grade 3 or less AAST injuries documented. Grade 4 injuries involved the liver (n = 3), spleen (n = 2) and kidney (n = 1), all having positive abdominal examinations. The five non-solid organ injuries involved the bladder (n = 2), abdominal vasculature (n = 2) and bowel (n = 1) – all were associated with solid organ injury and had positive abdominal examination, X-ray or FAST findings , macroscopic haematuria (p < 0.01), pelvic fracture or hip dislocation (p = 0.04) and positive FAST (p < 0.01). Negative abdominal examination, absence of macroscopic haematuria and negative FAST were negatively associated with abdominal injury.Referral details trending towards association with abdominal injury were positive abdominal examination  of all clinical details on request forms were associated with abdominal injury.5 concluded that bedside ultrasonography had the highest accuracy, that a combination of clinical findings were likely to be most useful to select patients who were unlikely to benefit from further evaluation, but that the ideal combination was yet to be determined. To our knowledge, this is the first study to investigate whether these are reliably reflected in the free-text request form.There is a wealth of literature investigating the value of various signs and symptoms, side-room tests and imaging investigations in predicting the probability of abdominal injury. In a systematic review, Nishijima et al.Our study had a number of key findings. Firstly, only 19% of clinical details reflected on free-text referrals at our institution were associated with imaging evidence of abdominal injury. This calls into question the role of such referrals and suggests there is room for substantial improvement in this domain.Secondly, we reaffirmed the pivotal role of meticulous clinical abdominal examination in the setting of blunt trauma. Of note, only 54% of patients undergoing abdominal CT had mention of abdominal examination findings interpretable as positive or negative. A potential explanation for this less than comprehensive documentation of abdominal findings is that guideline-driven imaging protocols frequently recommend abdominal CT to rule out occult abdominal injuries in patients with head injuries, citing that clinical abdominal examination is likely to be unreliable in this setting. This could lead less experienced clinicians to assume that abdominal examination findings are of limited value. Our study suggests that abdominal examination findings form a relevant component of referral and should be provided, whether positive or negative. A normal abdominal examination is predictive of the absence of abdominal injury.25 Efforts should be made to expand the use of FAST. This would involve developing appropriate skills amongst clinicians. Focused assessment with sonography in trauma training programmes are increasingly available, and ultrasound machines are becoming more affordable and portable. Any unit with a CT scanner should be equipped with basic ultrasound equipment.Thirdly, our study suggests that FAST could play a role in the reduction of abdominal CT utilisation in the blunt trauma setting, in line with findings of Sheng et al.27 The relatively high frequency (50%) of documentation on electronic requests could be because of the speed and ease of the test during the trauma admission procedure. Clinicians equivocating about the need of CT could include microscopic haematuria as a further motivation for requesting CT, particularly in the absence of other compelling indications. Our findings suggest that CT abdomen for isolated microscopic haematuria, in the absence of any other finding, is not justified.We found no evidence to support the provision of qualitative or quantitative information about microscopic haematuria, consistent with studies demonstrating its low value.Although free text electronic requests permit clinical information to be communicated without constraint, a major limitation is that provision of relevant content remains voluntary. Methods of improving the consistent provision of relevant clinical content on imaging requests are likely to strengthen the evidence base of this information and facilitate an optimal justification process. There may be a role of a drop-down menu-style electronic request, thus obliging referring clinicians to provide relevant information and restricting the communication of irrelevant information.There are limitations in the statistical analysis of free text referrals. The retrospective design meant that parameters were not specified in every case, thereby preventing determination of their diagnostic sensitivities and specificities. Prospective studies are needed to analyse systematically the diagnostic value of various contents on electronic request. Furthermore, we only conducted a univariate analysis. Given the complex clinical variables in trauma, a multivariate analysis controlling for confounding variables would represent a superior analysis. The capture of data pertaining to imaging tests performed prior to CT was limited in that it was occasionally impossible to determine whether findings had been diagnosed on examination or on imaging tests.The strengths of the study included the availability of comprehensive RIS data and ability to enrol consecutive patients with little exclusion.Key abdominal examination and basic imaging findings remain essential clinical details for the appropriate evaluation of CT abdomen requests in the setting of blunt trauma. Requests specifying a positive abdominal examination, macroscopic haematuria, pelvic fracture or hip dislocation, or positive FAST are associated with CT evidence of abdominal injury. Methods to improve consistent communication of relevant clinical details are likely to be of value.


In this review, we report the role of mTOR signaling in reparative regenerations in different tissues and body parts , and highlight how the mTOR kinase can be viewed as a therapeutic target to boost organ repair. Studies in this area have focused on modulating the mTOR pathway in various animal models to elucidate its contribution to regeneration. The diversity of metazoan species used to identify the implication of this pathway might then serve applied medicine (in better understanding what is required for efficient treatments in human diseases) but also evolutionary biology. Indeed, species-specific differences in mTOR modulation can contain the keys to appreciate why certain regeneration processes have been lost or conserved in the animal kingdom.A major challenge in medical research resides in controlling the molecular processes of tissue regeneration, as organ and structure damage are central to several human diseases. A survey of the literature reveals that mTOR  is involved in a wide range of regeneration mechanisms in the animal kingdom. More particularly, cellular processes such as growth, proliferation, and differentiation are controlled by mTOR. In addition, autophagy, stem cell maintenance or the newly described intermediate quiescence state, G Streptomyces hygroscopicus in 1972 from Rapa Nui (Easter Island). mTORC2 is insensitive to acute rapamycin treatment but chronic exposure can disrupt its structure. Raptor and Rictor protein scaffolds participate in assembling the different constituents of the complexes and binding substrates.The mTOR signaling pathway is highly conserved in eukaryotic organisms including unicellular photosynthetic eukaryotes , while tDetailed data about the structure, components and regulation of both TORC1 and TORC2 complexes are available in several recent reviews ,4,5. S6KRegeneration ability is an endogenous tissue or organ-specific characteristic. In metazoans, a large diversity of mechanisms is involved to repair or regrow the missing structure, organ or body part : For exaMany vertebrate species are capable of impressive feats of regeneration such as limb, tail or fin regeneration. Adult salamanders and teleosts have a higher regenerative potential as they are able to regenerate whole limbs and fins, which host a series of specialized tissues such as epidermis, nerves, bone, endothelium, soft mesenchymal cells, and fibroblast-like cells. For limbs, amputation is followed by the migration of epidermal cells to cover the wound and a blastema is formed, reminiscent of the embryonic limb bud. Caudal fin regeneration in zebrafish also implies wound covering by skin cells and blastema setup. Within this blastema, mesenchymal cells and osteoblasts proliferate a few hours after the onset of amputation. In mammals, regeneration in which the structure of lost tissue is recapitulated appears to be limited to the distal tip of the digit . In mousA study using the suppression subtraction hybridization (SSH) technique combined with bioinformatics analyses was performed on a freshwater teleost following fin amputation. Genes involved in TOR signaling were identified as differentially expressed during the caudal fin regenerative process . It, theFollowing caudal fin amputation in zebrafish, TOR signaling, reflected by the levels of the phosphorylated form of S6K (S6 Kinase), is active in wound epidermal cells, osteoblasts and proliferative proximal region of the blastema  Figure a. DuringIn the regeneration examples detailed above, growth factors are efficient mTOR activity-promoting agents. mTOR activity is necessary for cell proliferation, survival, differentiation, and growth during appendage regeneration. Molecular crosstalk such as exists between the Wnt/β catenin and mTOR pathways is an important element to consider in designing drugs that enhance regeneration. These examples of appendage regeneration are on the more spectacular end of the regenerative spectrum of the animal kingdom. Studies with tissue-specific regeneration in animal models after injury have an easier framework for which to extract data useful for treating human diseases. mTOR roles in specific cell types will be investigated separately in the next paragraphs along with how mTOR modulations can alter the microenvironment in a pro-regenerative fashion.Parhyale hawaiensis suggesting that this stem population was present in the bilaterian common ancestor . T. T−/−) d0 quiescence phase newly termed Galert [alert)  see c. mTORC1response .Interestingly, similar contralateral activation of mTOR was observed in the axolotl limb amputation model . The phoalert cell state, which is under the control of mTOR activity, serves as an illustration for improved competency. Any diseases displaying chronic muscle degradation might, therefore, consider inducible activators of TORC1 as suitable therapeutic molecules such as growth factors, amino acids or modulators of the regulatory elements of mTOR.Altogether, these data demonstrate that TORC1 activity is necessary to achieve the correct process of muscle regeneration for cell growth and cell proliferation. The regeneration-competency of satellite cells is also a factor that will influence the degree of recovery. The previously described GN-methyl-d-aspartate) is followed by the activation of TOR signaling in Müller glia and this activation is necessary for Müller glia-derived progenitor cells’ proliferation [In general, axons after injury do not spontaneously regenerate in the adult mammalian central nervous system. Interestingly, the mTOR pathway is involved in the differentiation of human retinal ganglion cells from induced pluripotent stem cells (iPS cells) . This moferation . This suPTEN deletion, Akt is strongly activated and the kinase GSK3β appears to be a core component of the Akt-induced axon regeneration [PTEN and TSC1/2 are two important molecular actors regulating the mTOR pathway. PTEN is a phosphate and tensin homolog, which acts upstream of mTOR as an inhibitor. TSC1/TSC2 or Tuberous sclerosis proteins 1 and 2 form a protein complex that inhibits mTOR activity. Retinal ganglion cells (RGCs) in the adult mouse normally degenerate after section of the optic nerve. Hypothesizing that manipulation of the intrinsic properties of retinal neurons can change their ability to regrow after axotomy, mice carrying the deletion of the lipid phosphatase PTEN in adult retinal ganglion cells were generated . These mneration   greatly favor axon regeneration of retinal ganglion cells . Indeed pe mouse a. SurpriPTEN deleted neurons when they are treated with rapamycin suggesting the implication of mTORC1-independent pathways [Studies that focus on the mechanistic explanations behind optic nerve axon regeneration have revealed which mTOR components are most likely involved. In the mouse optic nerve crush model, mTORC1 downstream effectors (S6K1 and 4E-BP) are differentially involved. S6K1 activation after crush clearly induced axon elongation and survival of optic neurons. In contrast, the deletion of 4E-BP (4E-BP1/2 double KO mice), which is normally phosphorylated and inhibited upon TOR activity, had no effect on regrowth  suggestipathways . Since Ppathways ,24.Finally, when considering retinal neuron axon regeneration, outgrowth following injury cannot be the only investigated parameter in a human disease-context. Juvenile and adult mice with either PTEN and SOCS3  co-deletion, or co-overexpression of osteopontin (OPN)/insulin-like growth factor 1 (IGF1)/ciliary neurotrophic factor (CNTF), showed regrowth of retinal axons and formation of functional synapses in the superior colliculus (SC), but not significant recovery of visual function . PTEN anThe medical challenge resides in finding the exact ways to stimulate mTOR activity to maximize the optic nerve’s regenerative properties. As exposed in this review, current leads include inhibitors of mTOR inhibitors , mTOR activators and growth factors. Conditions like glaucoma where the optic nerve is damaged and which is the leading cause of blindness in people over 60 could benefit from such treatments.Drosophila. During metamorphosis, neurons from the mushroom body are reshaped. This consists in parceling exiting axons followed by the re-extension of new ones from the cellular body. This phenomenon mimics cellular events occurring after axotomy in neuron and is different from initial axon growth from a newborn neuron. During mushroom body remodeling, axon regrowth is mediated via the TSC-Rheb-TOR pathway, which is activated by the nuclear receptor UNF [The TOR pathway is also involved in axon regrowth in ptor UNF . In thisptor UNF .Spinal cord injuries (SCI) have been connected to mTOR signaling in different ways. The spinal cord connects the brain to the peripheral nervous system. The mTOR pathway has been shown to promote or inhibit axon regeneration in SCI animal models. Most frequently, two types of SCI animal models are used; spinal cord injury and spinal cord hemisection with the former aiming for complete anatomical and functional damage of the spinal cord while the latter is an incomplete injury with a certain remaining nerve connectivity. Glial scars, formed by the activation of inactive astrocytes, involve the proliferation or hypertrophy of astrocytes, which create a physical and chemical barrier that hinders neuronal recovery . The conDrosophila monolayered epidermis is also a good system to study tissue repair after injury. One of the first events after injury is the formation of an actomyosin cable that will tighten around the wound. Then, the wound closure is ensured by the association of crawling cells to lamellipodia-carrying cells surrounding the wound. In the next experiments, Drosophila larvae were subjected to a laser beam that ablated cells of the epidermis. Wound closure clearly involves Insulin/IGF signaling (IIS) as shown in flies carrying the deletion of three insulin ligands or the expression of a dominant-negative version of the insulin receptor [Drosophila is also delayed in the presence of rapamycin [The receptor ,45,46. Wapamycin  . Intestinal stem cells of the gut proliferate to form an enteroblast (EB) population in which cells are able to differentiate into enterocytes (EC) or enteroendocrine cells. As they differentiate, EC undergo endoreplication which contributes to an increase in cell size. The endocycle is different from the mitotic cycle as DNA replication occurs without nuclear division resulting in polyploid cells with increased cell size. Analyzing how endocycling-induced EC growth is used during fly gut epithelium repair following stress, EC endoreplication was shown to be controlled by EGFR/MAPK  but not by TOR signaling [Barrier epithelia such as the posterior midgut epithelium of ignaling . The EGFignaling . These d2 exposure-induced injury: TOR is transiently activated upon chemical-induced damage but chronic activation of TOR induced a decline of basal cells population [The fruit fly intestine hosts intestinal stem cells (ISCs) that proliferate in response to regenerative stimuli. Using enteropathogen infection to mimic regenerative stimuli, fly guts were then dissected and labeled with anti-phospho-4E-BP antibodies. TOR activation was found to be necessary for the quick activation of the proliferation of ISCs . Howeverpulation   and rapamycin intraperitoneal injection to abrogate TOR activity in a 70% partial hepatectomy (PH) mouse model demonstrated the importance of the TOR pathway in the initial proliferation phase after resection [−/−, S6K2−/− hepatocytes accounting for the cell cycle progression delay reported in these genetically modified hepatocytes. In addition, rescue experiments using Cyclin D1 overexpression in S6K1−/−, S6K2−/− hepatocytes showed that cell cycle entry timing can be rectified after PH [Upon partial hepatectomy, the remaining and quiescent mammalian hepatocytes are able to reenter the cell cycle synchronously and proliferate to restore liver volume. The liver does not rely on a resident stem cell population but on the aptitude of its hepatocytes to reactivate proliferation after local signals such as tissue resection. The use of mice mutants  is a chronic degenerative joint disease characterized by gradual loss of articular cartilage, synovial inflammation, and subchondral bone remodeling. The mTOR pathway has been shown to be overexpressed in human OA chondrocytes . Drugs iOsteoporosis (OP) is a disease in which the density and quality of bone are reduced. A study in rats showed that rapamycin treatment reduced senile osteoporosis by activating osteocyte autophagy and preserving osteocytes and by a decrease in apoptosis of osteocytes and a decrease in number of osteoclasts . AnotherBone and dentin derive from stem cells from the apical papilla (SCAP) which are a subpopulation of mesenchymal stem cells (MSCs). SCAP are identified as a population of postnatal mesenchymal stem cells with the capacity for self-renewal and multipotent differentiation into osteoblasts/odontoblasts, adipocytes, and neural cells. Looking specifically at the Phosphoinositide 3 kinase (PI3K)-Akt-mTOR pathway, it was found that its suppression played a role in enhancing the in vivo and in vitro osteogenic/dentinogenic differentiation of stem cells from the apical papilla . A novelThe functional unit of the kidney is the nephron and adult neonephrogenesis is unequally distributed in the animal kingdom. The nephron is composed of a glomerulus and a tubule. The glomerulus contains podocytes, which help carry out the initial blood filtration. The tubule is where diverse molecules are secreted and reabsorbed. Adult mammals cannot form new nephrons contrary to cartilaginous fish, bony fish or certain amphibians ,71,72,73Medical approaches for treating kidney diseases have been focusing on the stimulation of endogenous reparative mechanisms or on stem cell therapies  and the de novo has been reported in the adult little skate, Leucoraja erinacea, an elasmobranch cartilaginous fish, after partial nephrectomy [During embryogenesis, nephrons are derived from a pool of self-renewing progenitors. Mammalian nephron progenitors stop propagation and are terminally differentiated within a few days after birth  indicatihrectomy . Similarhrectomy ,73. In threctomy . This sthrectomy   but few studies have investigated the role of TOR in this process. This last part of the review will explore mTOR signaling in whole-body regeneration (cnidarian and planarian) and asexual reproduction (tunicate). The freshwater cnidarian tion see . With thHydra, a kinetics of TOR mRNA by semi-quantitative RT-PCR at several time points was performed after amputation [Hydra and also in Drosophila [Hydra, TOR mRNA levels are maintained stable during the first 4 h post-amputation (hpa) then decrease until 32 hpa which might indicate that autophagy is activated during the first phase of regeneration. TOR mRNA synthesis restarts from 32 to 48 hpa probably reflecting a need for cell growth at this regeneration step [Initially described as a means of protein degradation , autophaputation . Indeed,osophila ,87. In tion step . It seemion step . In geneSchmidtea mediterranea, TOR and raptor are expressed in neoblasts and their knock-down by RNAi affect the initial mitotic response and blastema formation but not the differentiation that is taking place in existing tissues [Dugesia japonica) head regeneration (2 h and 6 h after injury) and uncovers a set of 162 proteins whose expression is modified. During the initial phase of regeneration, these proteins include several molecules related to protein synthesis and mTOR signaling [alert), only those residing locally within the stump of the amputated limb ultimately participate in the regrowth of the new limb. During planarian regeneration, neoblasts throughout the body are initially activated, but eventually, this activation becomes refined to the site of injury and blastema growth like in the axolotl or mice models [Active mTOR signaling has additionally been shown to be required during tissue regeneration by regulating stem cell activation and blastema outgrowth in the planarian regeneration model ,90,91. P tissues ,90,92. Ie models . Whole-bHydra, autophagy is activated during the process of regeneration in planarians. Cells that undergo autophagy express Dap-1 (death-associated protein). Loss-of-function experiments of the planarian ortholog of DAP-1 using RNAi were designed to investigate the role of autophagy for regeneration in Girardia tigrina. The experiments demonstrated that regeneration is affected in Dap-1 (RNAi) animals [Like in  animals . Interes animals . During  animals   stimulation. Retinoic acid is a morphogen derived from retinol (vitamin A) that plays important role in cell growth, differentiation, and organogenesis. RA stimulation in tunicates induces transdifferentiation-related genes [Budding (also called asexual reproduction, see modeling . It has modeling . The acted genes  and secoed genes . The mTOed genes . Once agmTOR signaling has emerged as a pivotal pathway in regulating cell proliferation and differentiation in a wide variety of cell types. From the evolutionary point of view, it is clear that some species are provided with extreme regenerative capacity while others display a more limited aptitude to regrow tissues and structures after amputation or surgical resection. This difference might be explained by the cooption of certain inhibitors of mTOR such as the one hidden in the long non-coding RNA, LINC00961, in damaged mammalian muscles. In contrast, a gradual accumulation of TOR activators by the renal stem cells around birth can explain why the maintenance of this population in the adult mammalian kidney is impaired. The diversity of regeneration processes displayed in the animal kingdom might conclusively constitute a tank for the identification of new TOR modulators that can be next adapted to medical treatments for human diseases.


The coronavirus disease 2019 (COVID-19) pandemic has had an enormous impact on healthcare systems globally. Infection prevention resources at the local level, especially in areas of high SARS-CoV-2 activity, have now been diverted to outbreak management. Although these efforts have understandably taken immediate priority, the impacts on traditional healthcare-associated infection (HAI) surveillance and prevention efforts remain concerning.A PubMed search utilizing the search terms “Impact of COVID-19 on healthcare associated infections” was performed on April 5, 2020, and yielded no directly applicable results. An informal Twitter poll was initiated on April 4, 2020, asking the infection prevention and hospital epidemiology community what percentage of their traditional infection prevention time had been diverted to COVID-19 response efforts. This query yielded 220 responses: 79.1% indicated spending >75% of their time on COVID-19 response efforts and another 13.2% indicated spending >50%–75% of their time on these efforts. Although these data are limited, they provide a snapshot of the potential resource diversion affecting the infection prevention community, and these percentages are consistent with our local experience.The potential impacts of the diversion of traditional infection prevention resources to focus on the COVID-19 response are numerous , vancomycin-resistant Enterococci (VRE), and extended-spectrum β-lactamase (ESBL)–producing gram-negative rods. The CDC also noted that gown use could be suspended in nonendemic settings for lower-risk patient encounters.1 Such strategies may lead, especially if the local healthcare personnel infrastructure is also compromised, to more cross transmission and HAIs.Another concern is the diversion of traditional personal protective equipment (PPE) resources given significant supply-chain shortages. These shortages resulted in the United States Centers for Disease Control and Prevention (CDC) recommending that hospitals experiencing gown shortages stop using isolation gowns for endemic pathogens such as methicillin-resistant 2 ASP efforts may be diverted to assist with COVID-19 response efforts, with a negative subsequent impact on activities such as post-antibiotic order review with provider feedback. An influx of critically ill patients may drive suboptimal antibiotic use with subsequent concern for the development of antibiotic resistance and C. difficile infection as well.The impacts on antimicrobial stewardship programs (ASPs), many of which are integrated with infection prevention programs, may also be significant.3 Fortunately, the CMS announced that reporting to the hospital-acquired condition (HAC) program is optional for the fourth quarter of 2019. Furthermore, data for the first 2 quarters of 2020 will not be counted for performance or repayment, and the related data do not need to be submitted to the CMS.4 Other non-CMS quality programs that utilize publicly reported HAI data to determine penalties should also consider adopting similar nonpenalty measures in the face of the current global health crisis.Another major concern is the potential impact of increased HAI rates on health systems in terms of public reporting and quality programs associated with reimbursement. Predictably, health systems will be negatively impacted by the global pandemic, and further penalties related to an increase in HAIs will further stress these systems. Although these measures are well-intentioned, consideration for relaxing penalties during the pandemic (and for a period afterward) should be considered. The Centers for Medicare and Medicaid Services (CMS) penalized ~800 hospitals for their HAI performance between October 2018 and September 2019, resulting in a 1% loss of reimbursement for Medicare patients.Health systems should consider creative ways to support and bolster their infection prevention programs during the COVID-19 pandemic. These efforts should include investment in information technology and personnel. Although health systems may be willing to invest resources and money in these programs, few trained infection preventionists and hospital epidemiologists are available in the United States. Beyond the current pandemic, significant resources should be invested to improve and sustain infection prevention infrastructure at the local, regional and national levels. Additionally, new investment in training and expanding the infection prevention workforce will be critical.The full impact of the COVID-19 pandemic on health systems and traditional HAIs remains to be determined. Significant infection prevention resource diversion is occurring to help manage the outbreak at the health-system level, which will predictably impact HAI surveillance and prevention efforts. The CMS has recognized the challenges facing the infection prevention community and have suspended penalties associated with the HAC program temporarily. Other quality programs should consider similar measures. Now more than ever, health systems should continue investing in their infection prevention programs (both infrastructure and personnel) beyond the current pandemic.


Furthermore, epihet can implement a biological network analysis workflow for transforming cancer-specific differential epigenetic heterogeneity loci into cancer-related biological function and clinical biomarkers. Finally, we demonstrated epihet utility on acute myeloid leukemia. We found statistically significant differential epigenetic heterogeneity (DEH) loci compared to normal controls and constructed co-epigenetic heterogeneity network and modules. epihet is available at https://bioconductor.org/packages/release/bioc/html/epihet.html.Intra-tumoral epigenetic heterogeneity is an indicator of tumor population fitness and is linked to the deregulation of transcription. However, there is no published computational tool to automate the measurement of intra-tumoral epigenetic allelic heterogeneity. We developed an R/Bioconductor package,  Recently, the availability of bisulfite sequencing including whole-genome bisulfite sequencing (WGBS) and reduced-representation bisulfite sequencing (RRBS), enables the quantification of DNA methylation at a single base-pair resolution6. Bisulfite sequencing reads covering multiple CpGs can profile the phased methylation states  for all CpGs in that read. Therefore, bisulfite sequencing provides a powerful tool to assess intra-tumoral cell-to-cell epigenetic variability. Many primary cancers feature with high levels of intra-tumor epigenetic heterogeneity, such as acute myeloid leukemia (AML)7, chronic lymphocytic leukemias (CLL)8, large diffuse B-cell lymphoma9, and Ewing sarcoma tumors10. These studies have shown that epigenetic diversification emerges in cancer cell populations and changes during disease progression9. Epigenetic variation causes neoplastic transformation and fitness11. Although some cancers (such as AML) have fewer genetic mutations than most other cancers12, higher tumor epigenetic heterogeneity burden is linked with worse clinical outcome in cancer patients9. In addition, epigenetic allelic heterogeneity is associated with higher levels of transcriptional heterogeneity7. Lastly, epigenetic heterogeneity broadly affects the cancer genome. The epigenetic heterogeneity is lower in gene regulatory region  than intergenic regions, CGI shelves and shores8.DNA methylation is a critical epigenetic modification. Aberrant DNA methylation is a hallmark of cancers and plays an important role in the initiation, progression, and manifestation of many cancersmethclone that we developed13, local disordered reads measured by proportion of discordant reads8, epiallele diversity measured by Epipolymorphism14 and Shannon entropy15. All these metrics consider the phased DNA methylation pattern spanning multiple adjacent CpGs when covered by a single sequencing read as one unit, which is called one locus. Heterogeneous methylation patterns at the given locus range from a complete of un-methylation to full methylation. DNA methylation state at a given locus in a cell population can form a mixture of epigenetic patterns  with different frequencies. Using these DNA methylation patterns, all of the metrics evaluate intra-tumoral epigenetic heterogeneity through examining epialleles that change their frequencies. To the best of our knowledge, there is no publicly available computational tool to automate the measurement of intra-tumoral epigenetic allelic heterogeneity, differential heterogeneity, functional evaluation, and visualization. To fill this gap, we developed an R/Bioconductor package epihet that can automatically calculate and characterize epigenetic heterogeneity based on methylation pattern information from the tool methclone. Further, epihet can perform differential epigenetic heterogeneity analysis, co-epigenetic heterogeneity (co-epihet) network construction, and visualization of results , and introduced epihet, an R package to compute intra-tumoral epigenetic heterogeneity and to perform further downstream analysis, which has been accepted by Bioconductor (https://bioconductor.org/packages/release/bioc/html/epihet.html). Firstly, the input of methclone v.02 is the Bam files of bisulfite sequencing data from cancer or normal samples , Epipolymorphism and Shannon entropy  visualizing the mean epigenetic heterogeneity of samples by different groups using boxplot; (2) performing Principal Component Analysis (PCA); (3) performing hierarchical clustering analysis; (4) performing t-Distributed Stochastic Neighbor Embedding (t-SNE) analysis to understand the relative similarity of epigenetic allele variations among different groups. To demonstrate the package, we applied epihet to 6 primary AML patients with silenced CEBPA gene expression (CEBPA-sil) from Glass et al.16 and 14 normal bone marrow (NBM) CD34+ cell samples from Li et al.7. Methylation profiles of these samples were measured using eRRBS. Here, mean Epipolymorphism of CEBPA-silenced patients is higher than normal samples. Multiple clustering analyses show that cancer and normal samples can form distinct clusters based on epiallele heterogeneity  loci in one cancer by comparing cancer with normal samples. Statistically significant DEH loci were selected using the absolute value of mean difference of epigenetic heterogeneity and multiple testing adjusted p-values calculated using t-test or permutation test. MA plot is employed to visualize DEH loci  network and performing network analysis to understand epigenetic mechanisms of cancers. The users can construct locus-level or gene-level co-epihet network. Here, epihet provides promoter, intron, extron, CpG shores and CpG island annotation files for gene annotation. The users can also download customized genome region in BED format from UCSC table browser which they are interested to associate genomic loci with genes, and create the GRanges objects epihet required by GemomicRanges Package17. Next, epihet identifies epigenetic modules for co-epihet network. Modules are labeled by different colors, here grey color is reserved to loci/genes which are not part of an epigenetic module  of each module, which was calculated using epigenetic heterogeneity levels of all loci/genes within a module and represented the average epigenetic heterogeneity level of a module. When the users supply the clinical traits of patients, such as age, gender, survival time, epihet can identify clinically significant modules through evaluating the correlation between the PC1 of each module and clinical traits  to determine modules significantly enriched by DEGs through hypergeometric test. In Fig. epihet can also return the degree, centrality, betweenness and closeness of nodes in the module to help the users to understand the network topology property. Finally, epihet investigates the function of each module by performing pathway enrichment analysis using hypergeometric test. The users can specify cutoff for p-value to select significantly enriched pathways  based on DEH loci or genes annotated by DEH loci. Finally, the users can perform all the analyses involved in epihet based on the customized epigenetic heterogeneity metrics. In summary, epihet fills a need of intra-tumoral epigenetic heterogeneity calculation tool and is valuable tool for intra-tumoral epigenetic heterogeneity study in cancers.The new version 4/16 different epialleles. Our tools can implement the four main methods for measuring epigenetic heterogeneity: proportion of discordant reads (PDR), Epipolymorphism, Shannon entropy and Delta entropy. The first three measures local epigenetic heterogeneity at a given locus, which can be calculated by our R package epihet. The difference of three methods is how variance of these patterns is calculated. Each method is built on slightly different assumptions and uses different equations. Additionally, each method has distinct advantages. The advantage of the PDR approach is its simplicity—it divides reads from the same locus into two categories: discordant vs concordant. Thus, it is straightforward to integrate PDR with other biological or genomic features. On the other hand, Epipolymorphism and Shannon entropy capture the information on all 16 possible epiallele patterns that can display at individual locus. Specifically, Epipolymorphism is a statistical measurement of variance. Epipolymorphism measures the probability of selecting two distinct patterns by randomly sampling. Whereas in information theory, Shannon entropy examines chaos in organized systems. Shannon entropy is designed to consider the proportion of all sixteen possible patterns together. Finally, Delta entropy evaluated the clonal dynamics of epialleles between different individuals or different stages within the same individual, which can be calculated by our tool methclone v.02.Epigenetic heterogeneity is calculated by considering the methylation state of a given locus (a group of adjacent four CpG sites). An epiallele is one of a number of alternative DNA methylation patterns of the same genetic locus. 4 CpGs on one locus can create 28. A bisulfite sequencing read at a given locus was classified as a concordant read or a discordant read. Here, a concordant read is one that shows unmethylated or methylated state at all CpG sites of a given locus. A discordant read is one that shows varying methylated and unmethylated states at a given locus, such as one methylated cytosine followed by three unmethylated cytosines. PDR at each locus is defined as The proportion of discordant reads (PDR) is a measure of locally discordant DNA methylation14. Epipolymorphism is calculated as pi is the fraction of each DNA methylation pattern i in the cell population.Epipolymorphism of a given locus in the cell population is defined as the probability that two epialleles randomly sampled from the locus differ from each other15. Shannon entropy of a given locus is calculated as pi is the fraction of each DNA methylation pattern Shannon entropy is defined as the chance that two randomly chosen epialleles (reads) have different methylated states of a given locus13. Briefly, the epiallele patterns of compositional changes between cancer patients and normal control samples were examined to calculate the combinatorial entropy change  considers the clonal dynamics of epialleles between different individuals, or within the same individual at different stagesepihet employed three methods to examine whether samples from one group form a biological meaningful cluster. First, epihet is used to cluster samples using hierarchical clustering analysis. The tool enables the users to select the distance metric between samples  and cluster method used in the hierarchical clustering algorithm . epihet returns results as a heatmap with column annotation based on user-defined groups of the samples. Second, epihet can also perform Principal Component Analysis (PCA) on epigenetic heterogeneity matrix of samples. A scatter plot of the first two principal components could be created to show the highest variation through the data. Third, epihet allows the users to perform t-Distributed Stochastic Neighbor Embedding (t-SNE) analysis to map high-dimensional epigenetic heterogeneity matrix onto two dimensions while conserving the high-dimensional structure of the data. The users can also visualize the samples in a scatter plot based on the pairwise distances in high dimension. The plots can be colored based on user-defined groups of samples. Before the cluster analysis is performed, an epigenetic heterogeneity matrix has been formed, containing the samples and only those loci shared by at least a certain percentage of the samples. The users can specify epigenetic heterogeneity measure  through the argument ‘value’. In hierarchical clustering analysis, epihet has the argument to set the top of percentage of loci based on standard deviation to be used for analysis.epihet identifies differential epigenetic heterogeneity (DEH) loci in the one cancer based on epigenetic heterogeneity mean difference of a locus between patients in cancer type and normal samples. To increase the statistical power, a two-stage approach was used that first filtered loci by a criterion independent of the statistical test18. epihet has the argument to set the absolute value of mean difference of epigenetic heterogeneity values of a given locus between two groups, such as cancer and normal control samples to filter some loci for further analysis. For PDR and Epipolymorphism, we designed epihet to implement t-test for determining significance of differential epigenetic heterogeneity across all the loci. Significantly differential Shannon entropy was assessed using permutation test19. The default number of permutation tests to be implemented is set to 1000. Specifically, given a locus, there are two lists of Shannon entropy for n1 cancer samples and n2 normal samples. First, we calculated the difference of Shannon entropy between cancer and normal samples. Then, we generated a new list A containing all n1 + n2 Shannon entropy from the two lists. Next we randomly permute the elements of A, then recalculate differential Shannon entropy, where the first n1 elements of A as Shannon entropy of cancer samples, the last n2 elements of A as Shannon entropy of normal samples. Finally, p-value was defined as the proportion of the random differential Shannon entropy that are larger than or equal to the original differential Shannon entropy. Additionally, the users can select one of t-test and permutation test to identify DEH loci for the customized metrics through the argument ‘permutationtest’. Statistically significant DEH loci were selected based on multiple testing adjusted p-values and the absolute value of mean difference of epigenetic heterogeneity. The users can define increased/decreased DEH loci based on the sign of the difference of mean epigenetic heterogeneity between cancer patients and normal control samples.21. epihet enables the users to construct co-epigenetic heterogeneity (co-epihet) network based on the DEH loci using the WGCNA R package22. We have two options to be employed to construct co-epihet network. The first option is to measure the correlation of epigenetic heterogeneity between any two DEH loci and construct locus-level co-epihet network. The second option is to measure the correlation of mean epigenetic heterogeneity between any two genes containing DEH loci within genomic region and construct gene-level co-epihet network. Allowed correlation methods are Pearson and biweight midcorrelation. Then, epihet identified co-epihet modules using hierarchical clustering, in which loci/genes were highly correlated in their epigenetic heterogeneity levels.Biological network has been widely used to describe interactions between biological entities of interest. Co-methylation network and epigenetic modules play important roles in understanding epigenetic mechanisms of cancers23. Then, epihet annotated co-epihet modules by the differentially expressed genes (DEGs), which the users can provide. epihet uses a hypergeometric test to identify the significantly enriched modules by DEGs. If no module is significantly enriched by DEGs, epihet returns the modules which contain DEGs. epihet draws scatter plot that visualizes the distribution of adjusted p-values for modules significantly enriched by DEGs or the distribution of percentage of DEGs for modules annotated by DEGs.Firstly, Reactome pathway enrichment analysis were performed through a hypergeometric test. The enrichment analyses were performed using the ‘ReactomePA’ R packageSupplementary Figures.


Spouses of cancer survivors are 33% less likely to receive guideline-concordant depression treatment than other married adults. However, depression is only one of many manifestations of psychological distress for caregivers. This exploratory study sought to assess the paths by which caregivers access mental health-related treatment. Using nationally representative data from the Medical Expenditures Panel Survey, we assessed the proportion of caregivers who received a mental health-related prescription or psychotherapy visit across care settings , provider type , and visit purpose . In addition, we assessed the health condition(s) associated with the treatment. The findings indicate that a plurality of caregivers accessed mental health-related treatment through an office-based visit (90%) with a primary care provider (47%). A minority accessed this care through a psychologist or psychiatrist (11%) or a physician with another specialty (12%) or other provider types. Nearly a third accessed treatment as part of a regular check-up (32%). These patterns did not differ from the general population after controlling for sociodemographic characteristics. Interestingly, mental health-related treatments were associated with a mental health diagnosis in only a minority of caregivers. The findings confirm the importance of regular primary care as a door way to mental healthcare, and highlight the range of potential paths to care. Future research will examine the correlates of accessing care across path types.