Capsular contracture is a common adverse outcome following implant breast reconstruction, often associated with radiation treatment. The authors hypothesize that muscle fibrosis is the main contributor of breast reconstruction contracture after radiation. Retrospective chart review identified patients that underwent DTI reconstruction with pre-or post-operative breast irradiation. Signs of capsular contracture were assessed using clinic notes and independent graders reviewing two-dimensional images and anatomic landmarks. Capsular contracture rate was greater in the subpectoral vs. prepectoral group . When compared to prepectoral DTI reconstruction in irradiated patients, subpectoral implant placement was nearly 4 times as likely to result in capsular contracture (p < 0.01). Rates of explantation, infection, tissue necrosis, and hematoma were comparable between groups. We also found that when subpectoral patients present with breast contracture, chemoparalysis of the muscle alone can resolve breast asymmetry, corroborating that muscle is a key contributor to breast contracture. As prepectoral breast reconstruction is gaining popularity, there have been questions regarding outcome following radiation treatment. This study suggest that prepectoral breast reconstruction is safe in an irradiated patient population, and in fact compares favorably with regard to breast contracture. Immediate prosthesis placement remains the leading method of reconstruction following mastectomy3. Two-stage reconstruction with tissue expander (TE) placement is most commonly used to correct mastectomy defect and restore breast form4. There is an increasing trend towards direct-to-implant (DTI) reconstruction in many centers, where the permanent implant is placed at the time of mastectomy in a subpectoral position, with the breast soft tissue supported along the inferolateral pole with a biomaterial surgical mesh, such as acellular dermal matrix (ADM) or synthetic material5.Breast cancer is the most common malignancy to affect women, accounting for a significant proportion of cancer-related mortality in the general female population6. One chief factor driving prepectoral breast reconstruction is to minimize breast animation deformity that is commonly seen with subpectoral implant placement9. Placement of the tissue expander or implant within the prepectoral space reduces breast animation deformity and mitigates discomfort that may result from elevation of the pectoralis major muscle11. Early retrospective investigations have demonstrated objective cosmetic advantage following prepectoral breast reconstruction, as well as favorable patient reported outcomes when comparing prepectoral TE reconstruction to subpectoral TE placement14.With improvement in mastectomy skin flap viability, many surgeons have revisited implant placement in the prepectoral plane17. Breast irradiation is widely reported to be an independent risk factor for post-operative complications, including surgical site infection, mastectomy skin flap necrosis, and capsular contracture20. In fact, a number of studies reported that patients who underwent PMRT following TE reconstruction were more likely to experience reconstruction failure compared to their non-irradiated cohort22. With regard to prepectoral breast reconstruction, Elswick, et al. reported higher rates of overall complication, including capsular contracture, although these findings were not statistically significant23. In contrast, Sigalove, et al. recently demonstrated that PMRT following two-stage prepectoral breast reconstruction was not associated with increase risk of adverse outcomes in the short-term, with average follow up of 25.1 ± 6.4 months24. With these conflicting reports, the impact of PMRT on capsular contracture within patients undergoing prepectoral DTI reconstruction remains unclear, as available studies are limited by sample size, heterogeneity in reconstruction methods, and lack of matched control between prepectoral and subpectoral patient groups. Additionally, most of the available data are for two-stage TE breast reconstruction and not for single-stage DTI reconstruction.Importantly, there has been a rise in the rate of post-mastectomy radiation therapy (PMRT) in recent years27. Radiation causes soft tissue fibrosis. In patients with subpectoral breast implant breast reconstruction, the contracture affects skin, capsule and muscle. It has been suggested that fibrosis of contractile muscle tissue could predispose patients after subpectoral reconstruction to breast contracture and implant deformation29. Evidence supporting muscle fibrosis to be a main contributor to contracture can be found in a recent investigation reporting favorable breast contracture rates following prepectoral breast reconstruction when compared to submuscular placement, in two-stage reconstruction30. Implant placement in the prepectoral plane avoids surgical manipulation of the muscle and the implant is not subject to deformation from muscle fibrosis and contracture following PMRT. Therefore, this study aims to compare capsular contracture rates between prepectoral and subpectoral breast reconstruction cohorts. We hypothesize that the prepectoral DTI breast reconstruction will be associated with lower incidence of capsular contracture when compared to subpectoral implant placement in an irradiated patient population.Investigation of capsular contracture as a primary safety endpoint following prepectoral breast reconstruction in an irradiated patient population serves to address a current gap in knowledgeRetrospective chart review at the tertiary academic medical center, Massachusetts General Hospital, was conducted with the approval of and in accordance to the guidelines of the Partners Healthcare Institutional Review Board. Patients who underwent immediate DTI breast reconstruction with breast irradiation, performed by the senior authors between January 2015 and May 2018, were identified. The prepectoral reconstruction group included any patient who underwent prosthesis placement following ADM or Vicryl mesh–based attachment along the anterior margin of the pectoralis major. Patient demographic, oncologic, clinical data were analyzed and pre- and post-operative clinical photographs were collected. The subpectoral group was defined as any patient who underwent implant placement within a subpectoral pocket, with inferolateral reinforcement using surgical mesh. Those patients who underwent breast reconstruction with total or partial muscle coverage were excluded from the study. Those with partial muscle coverage underwent only pectoralis major muscle dissection and tacking onto the mastectomy skin flap. Therefore, lower pole of the implant was covered solely covered by the skin flap without muscle coverage.31. In brief, a pocket of Vicryl mesh was created to enclose and support the silicon implant. If ADM was not used, the implant was fashioned to the prepectoral pocket with interrupted Vicryl sutures. If ADM was used, a piece of 18 × 8 cm was fashioned exclusively on the anterior side of the Vicryl pocket. Implant position in the prepectoral plant was controlled by suturing along the inframammary fold. The use of Vicryl mesh alone or Vicryl mesh with ADM adjunct was based on surgeon experience and technique.Following mastectomy with inframammary incision, a sizer implant was used to assess mastectomy skin flap viability and identify optimal breast implant volume. The surgical techniques employed for Vicryl or ADM prepectoral breast reconstruction by the senior author have been described previously34. The pectoralis major muscle was elevated along the inferior and lateral margins. Vicryl mesh or ADM was sutured to the chest wall along the inframammary fold, and along the inferolateral border of the raised muscle. The implant was then placed within the subpectoral pocket. In this way, the superior pole of the implant was covered by pectoralis major muscle, whereas inferolateral surface of the implant was covered by surgical mesh.Mastectomy was performed using inframammary incision. Subpectoral implant reconstruction was performed as described previously1; axillary fold crease2, flattening of inferior pole projection3, superolateral displacement of nipple areolar complex4, dimpling or creasing of the soft tissue envelope at the level of the pectoralis major muscle. Superolateral displacement of the nipple was not recorded for patients with skin-sparing mastectomies. The data was then combined into a single data set, with two data points  per patient for each of the aforementioned criteria. Given the dichotomous nature of the endpoint variables, it stands to reason that blinded, independent review of a single group of patients generates two sets of unique data, which can be combined and subsequently analyzed. In addition, the following post-operative complications were recorded: surgical site infection, mastectomy skin flap necrosis, hematoma, revision, and explantation. Those complications that required reoperation were recorded, as surgeon management of post-operative complications varies even within a single institution. Reoperation can be objectively assessed during chart review and provides the most accurate representation of patient outcome following breast reconstruction. A Cohen’s kappa (κ) was calculated to determine inter-rater reliability among independent evaluators. BMI was calculated as mass/meters squared (kg/m2).Variables recorded for each patient were age at surgery, body mass index (BMI), obesity, history of smoking, laterality of cancer, cancer pathology, cancer grade, timing of breast irradiation, neoadjuvant chemotherapy, implant size, diabetes, mastectomy type (nipple-sparing v. skin-sparing), axillary management (axillary lymph node dissections and sentinel node biopsies), surgical adjunct (ADM v. Vicryl mesh), follow-up interval, and laterality. The primary endpoint of interest was rate of capsular contracture, defined as breast deformity resulting from either fibrous capsule formation or muscle contracture around the prosthetic device, which manifests as functional asymmetry, decreased upper extremity range of motion, and pain with activation of the pectoralis major muscle. Two blinded evaluators (LG and RE) assessed capsular contracture among a standardized set of patient photographs. Objective evaluation of the following landmarks was conducted to evaluate asymmetry30. We calculated an a priori sample size of 62 total breast evaluations at a significance of 0.05 and a power of 80%.Data were analyzed using SPSS 24 . Power analysis was conducted to determine the sample size necessary to detect an effect size of 36.1%, which represents the most recently reported variance in capsular contracture rate between prepectoral and subpectoral immediate implant-based breast reconstruction in an irradiated patient populationvia Student’s t-test and non-normally distributed variables were evaluated using the Mann-Whitney test. Fisher’s exact testing was used to compare categorical variables. Unadjusted logistic regression was used to analyze outcome data by patient. A penalized (Firth) logistic regression model was constructed to identify relationship between prepectoral breast reconstruction and post-operative complication by controlling for confounding variables , mastectomy type, surgical adjunct, implant size, and post-operative follow-up). Firth logistic regression restricts maximum likelihood estimations to prevent bias that may result from small event sizes. Covariate variables that are known predictors of complication or were unmatched between patient groups were included in the regression models35. For each outcome endpoint, an odds ratio, 95% confidence interval, and p value were calculated. Statistical significance was defined as p < 0.05.Univariate analysis was conducted to compare patient characteristics between prepectoral and subpectoral groups. Normality was determined using the Shapiro-Wilk test. Normally distributed factors were compared All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Ethical approval: This article does not contain any studies with animals performed by any of the authors.Informed consent was obtained from all individual participants included in the study.We identified 47 patients who underwent either bilateral (n = 34) or unilateral n = 13) mastectomy followed by immediate reconstruction, who also had either pre- or post-mastectomy radiation treatment, resulting in a total of 81 reconstructed breasts. Although far more patients were found in the database to have underwent implant breast reconstruction and radiation treatment, these 47 patients had complete photographic documentation pre-operatively, before radiation treatment and after radiation treatment over time. Patients that lacked photographic documentation at any of these clinical junctures were excluded. Subpectoral implant-based reconstruction was performed in 27 radiated patients, whereas the remaining 20 underwent prepectoral implant placement and radiation treatment. Nipple sparing mastectomy was performed in 32 (68.1%) patients, while skin-sparing mastectomy was performed in 15 patients. The mean age of the women at time of surgery was 50.8 ± 11.3 years. Table 3 mastectThe most common post-operative complication was hematoma [n = 2 (4.3%)], followed infection and explantation [n = 1 (2.1%)] , compared to those who underwent prepectoral implant-based reconstruction   is the dominant contributing pathogenic factor.In patients with subpectoral breast reconstruction that suffer from breast contracture and asymmetry after radiation, there is a consistent clinical observation that the muscle is the main contributor to the contracture and pain. When these patients present for revision procedure to address breast contracture, the contracted superior pole contour is marked (dotted line) pre-operatively. The desired superior pole contour is marked 2–4 cm below (solid line), to match the superior pole contour of the contralateral non-irradiated breast. As soon as the patient undergoes induction of general anesthesia, the contracted breast mound descends from the dotted line to the desired solid line, before an incision is even made. The descent of the contracted breast mound is due to the short-acting paralytic that has relaxed the fibrotic pectoralis major muscle that was contracted over the anterior contour of the breast implant. In these patients with radiation associated capsular contracture, the mitigation of breast asymmetry by muscle relaxation provides physiologic evidence that points to the muscle as the main contributor of the contracted breast pathology. In fact, we propose that in the breast reconstruction patient population after radiation, the clinical diagnosis of 36. In addition, recent studies demonstrate no significant difference in post-operative complication rates between prepectoral breast reconstruction and subpectoral prosthesis placement, which suggest comparable safety profiles between the two reconstruction methods23. However, the majority of studies evaluating post-operative complication rates between prepectoral and subpectoral breast reconstruction focus on two-staged, TE-based breast reconstruction. Given the rising trend toward DTI reconstruction, this study contributes a matched patient cohort study assessing safety clinical endpoints in the context of single-stage breast reconstruction to better guide clinical decision-making. It is reasonable to speculate that patient outcomes, such as capsular contracture, could vary with the extent of implant coverage by the pectoralis major muscle, especially within the irradiated field. Therefore, this study is unique in examining capsular contracture rates between prepectoral and subpectoral DTI reconstruction patient populations.Emerging studies suggest that implant placement in the prepectoral space confers aesthetic and functional benefit to patients following mastectomy, including mitigation of animation deformity and muscle spasm associated with dissection of the pectoralis major muscletiming of breast irradiation (pre- versus post-mastectomy), which suggests that prepectoral breast reconstruction is associated with a lower rate of capsular contracture regardless of the timing of breast irradiation. What is also reassuring, is that we found that the prepectoral breast reconstruction patients did not experience increased rates of capsular contracture in DTI reconstruction, corroborating findings from other studies reporting on primarily two-stage TE cohorts . Therefore, this study confirms a known predictor of capsular contracture. Furthermore, we demonstrated no significant difference in secondary endpoints of surgical site infection, mastectomy skin flap necrosis, hematoma, revision, and explantation, supporting emerging reports that prepectoral breast reconstruction shares a comparable safety profile as subpectoral implant placement in irradiated patients.The strength of this study is the comparison of capsular contracture rates between prepectoral and subpectoral DTI breast reconstruction groups in an irradiated patient population with over 18-month mean follow-up. Subpectoral breast reconstruction was associated with significantly greater rate of capsular contracture compared to prepectoral breast reconstruction by univariate analysis. This study and others debunk the notion that prepectoral breast reconstruction leads to greater capsular contracture as was the experience of the 1970s when soft tissue flaps were likely thinner and surgical mesh was not used to support the prosthetic device. Numerous studies have reported PMRT to be an independent risk factor for capsular contracturePrepectoral DTI breast reconstruction is associated with a lower rate of capsular contracture in an irradiated patient population when compared to subpectoral breast reconstruction. With continued refinement of prepectoral breast reconstruction methods, it is necessary to evaluate surgical outcomes in irradiated patient populations to improve patient outcomes in this higher risk group. We also propose that muscle fibrosis from radiation treatment is the main contributor to breast contracture and asymmetry, thus treatment of post-radiation breast contracture should address the muscle specifically.


Device-related infections in orthopaedic and trauma surgery are a devastating complication with substantial impact on morbidity and mortality. Systemic suppressive antibiotic treatment is regarded an integral part of any surgical protocol intended to eradicate the infection. The optimal duration of antimicrobial treatment, however, remains unclear. In a multicenter case-control study, we aimed at analyzing the influence of the duration of antibiotic exposure on reinfection rates 1 year after curative surgery.This investigation was part of a federally funded multidisciplinary network project aiming at reducing the spread of multi-resistant bacteria in the German Baltic region of Pomerania. We herein used hospital chart data from patients treated for infections of total joint arthroplasties or internal fracture fixation devices at three academic referral institutions. Subjects with recurrence of an implant-related infection within 1 year after the last surgical procedure were defined as case group, and patients without recurrence of an implant-related infection as control group. We placed a distinct focus on infection of open reduction and internal fixation (ORIF) constructs. Uni- and multivariate logistic regression analyses were employed for data modelling.p = 0.029) and facture fixation device infections  remained independent predictors of reinfection. In the subgroup of infected ORIF constructs, univariate point estimates suggested a nearly 60% reduced odds of reinfection with systemic fluoroquinolones  or rifampicin treatment  for up to 31 days, although the width of confidence intervals prohibited robust statistical and clinical inferences.Of 1279 potentially eligible patients, 269 were included in the overall analysis group, and 84 contributed to an extramedullary fracture-fixation-device sample. By multivariate analysis, male sex (odds ratio [OR] 2.06, 95% confidence interval [CI] 1.08 to 3.94, The optimal duration of systemic antibiotic treatment with surgical concepts of curing wound and device-related orthopaedic infections is still unclear. The risk of reinfection in case of infected extramedullary fracture-fxation devices may be reduced with up to 31 days of systemic fluoroquinolones and rifampicin, although scientific proof needs a randomized trial with about 1400 subjects per group. Concerted efforts are needed to determine which antibiotics must be applied for how long after radical surgical sanitation to guarantee sustainable treatment success. Surgical site infections (SSI), including deep, implant-associated infections, remain serious complications in orthopaedic surgery, with marked impact on morbidity and mortality. They often result in multiple revisions, poor functional and health-related outcomes, and significant financial burden to health care systems worldwide –6.Joint arthroplasty registries have greatly contributed to the knowledge about the risk of infection in high-income countries. Various definitions of SSI, follow-up intervals, and effect modifiers like age, co-morbidity, treatment indication, type of components etc. notwithstanding, national benchmarks typically range from 0.5 to 2.0% in primary, elective total hip and knee replacement –10. ReviIn contrast, SSI after fracture fixation are far less understood, and registry or other large-scale data are generally missing. Numerous, often combined approaches are used for surgical fracture stabilization  conditional on the individual anatomical site, joint and soft tissue compromise, individual patient profiles, and so on. Plate and screw constructs are obviously at the highest risk of infection, even if ORIF is performed in a minimally-invasive fashion. The reported average SSI incidence rate after surgical fixation of lower extremity fractures is about 5% –22. Yet,Key principles of preventing surgical site and implant-associated infections comprise proper skin disinfection , peri-opDeep SSI, specifically implant-related infections, demand aggressive surgical management. Decisive factors are the type of implant , early or late onset of infection, stability etc., conditionally prompting serial debridement, one- or two-stage revision, septic arthrodesis, or complex reconstruction including muscle flaps or other types of tissue transfer –45. RegaThe aim of the present multicenter case-control study was to investigate the influence of the duration of antibiotic treatment on the rate of recurrence  after surgical management of various orthopaedic device-related infections. Give the paucity of data and absence of clear-cut recommendations in this setting, we placed a focus on infected osteosynthesis constructs, namely extramedullary implant infections.http://www.hicare.de. All individual project modules, including this investigation, received ethical approval by the central and local Institutional Review Boards (IRB), and fully complied with national and European laws of data safety and protection.This was a multi-institutional case-control study conducted at three academic tertiary referral hospitals in Germany . This investigation was part of a larger network project aiming at preventing the spread of multi-resistant bacteria in the German Baltic region and Federal State of Mecklenburg-West-Pomerania, as funded by the German Ministry of Education and Research (BMBF). Details of the project can be assessed at “In patients with an infected total joint arthroplasty or fracture fixation device demanding surgical revision, does the duration of systemic antimicrobial treatment impact the risk of re-infection within one year after the final surgical procedure?”We posed the following primary research question in a PICOT  format:“In patients with an infected extramedullary fracture fixation device demanding surgical revision, does the duration of systemic antimicrobial treatment impact the risk of re-infection within one year after the final surgical procedure?”We decided to break down the overall dataset to answer the following, more specific secondary PICOT question:We defined cases as patients who sustained any reinfection demanding any surgical revision ≤1 year after the index procedure. Controls were defined as patients who did not sustain any infection demanding surgical revision  ≤1 year, being aware the control status is fragile and may change to a case status with longer follow-up intervals. Given the catchment area and healthcare mandate of recruiting centers we presumed that patients normally followed-up as outpatients who did no longer show up or were admitted for reinfection within 1 year represented controls.Hospital databases were searched for eligible patients with the diagnosis of infection of total joint replacements or fracture fixation devices between 1999 and 2014 using ICD-10 codes T84.5 to 84.7 (complications caused by orthopaedic arthroplasties or implants) and M86.0 to M86.9 (osteomyelitis). Individual electronic and paper hospital charts were thoroughly reviewed to identify patients with an infection of a total hip or knee joint replacement, or infection of an osteosynthesis construct of the humerus, forearm, femur, tibia, fibula, ankle, or calcaneus were included in the study. Apart from ≥1 documented surgical procedure intended to cure the initial and reinfection  , 48, diaThe primary endpoint of this study was reinfection within 1 year after the last surgical procedure intended to cure or control the primary infection. The primary exposition variable was duration of antibiotic treatment . Due to its variance, it was dichotomized into “administration of systemic antibiotics <14 days” and “administration of systemic antibiotics ≥14 days”. Secondary exposition variables were patient demographics, comorbidity , American Society of Anesthesiologists physical status (ASA) classification, type of implant, microbial spectrum, local antibiotic treatment, antibiotics used, doses and routes of administration.2 or Kruskal-Wallis test for bivariate, exploratory group comparisons.We provided raw numbers and percentages for categorical data. Continuous measures were expressed as means with standard deviations (SD) or medians with interquartile ranges (IQR), based on the underlying distribution and skewness. Where appropriate, we employed the chip-values < 0.2 and variables with a confounding effect were included in the model. To test possible confounding effects of secondary exposition variables, each of these variables were assessed by single logistic regression analyses. If unadjusted odds ratios (OR) differed from adjusted OR by 10%, the secondary exposition variable was included in the model. We also used exact logistic regression analysis as a computationally more intensive tool which is regarded to provide more robust estimates in case of small sample sizes and skewed distributions [Uni- and multivariate logistic regression analysis were used for modelling the association between primary and secondary exposition variables and endpoints. Exposure variables with univariate ibutions .For multivariate analysis in the infected fracture-fixation device scenario, age was categorized into quartiles. Days of systemic exposure to fluoroquinolones and rifampicin were clustered in clinically meaningful categories with comparable sample sizes. A first-order interaction term was introduced respecting combined fluoroquinolone-rifampicin antimicrobial therapy. Model fit and explained variance was assessed by the area under the receiver operating characteristics curve (AUC / ROC).p-values < 0.05 may be interpreted as incompatible with chance, although we did not go for inferential testing here. Statistical analysis employed SPSS  and STATA .OR were calculated and reported with 95% confidence intervals (CI). Results with In total, electronic hospital databases revealed 1279 patients potentially eligible for this study. The screening and selection process resulted in complete data sets from 269 patients  to be included in the statistical analysis. Of those, 84  had infections of extramedullary fracture fixation devices.Thus, we roughly had a an overall ratio of cases to controls of 1: 4, and a 1: 2 pairing with regard to infected ORIF constructs. The study profile according to STROBE recommendations is shown in Fig. Sociodemographic and clinical characteristics of the eligible sample at the time of first revision are presented in Table p = 0.049). Male gender , smoking , and infection of a fracture fixation device  were associated with an increased likelihood of developing relapse. In the multivariate model, male sex  and fracture fixation device infections  remained predictors of reinfection. The odds of recurrence of implant-related infections was 1.85 higher for patients with antibiotic treatment lasting ≥14 days than for those with treatment shorter than 14 days .Univariate analysis suggested an increased risk of recurrent infection with longer antibiotic treatment  is that doctors opted for prolonged suppressive antimicrobial treatment because of patient- and disease-related characteristics not accessible by hospital and administrative chart documentation. It must not be concluded from the present data that prolonged systemic antibiotic therapy increases the risk of recurrent infection. This leads to the major limitations of this study- it was retrospective, used hospital chart data, and, after applying predefined selection criteria, enrolled a rather small sample of patients.We did not account for single- and two-stage revision protocols in infected total joint arthroplasties, and patients with subsequent reinfections may have consulted another hospital, thereby introducing verification bias.We had deliberately chosen a case-control design as orthopaedic device-associated infections in the developed countries are serious but comparably rare events, and the incidence of reinfection after an index infection currently remains unpredictable. In this situation, a case-control strategy is generally more efficient than a cohort approach to estimate possible effect sizes but only allows for limited causal inference between exposure and outcome variables. A major lesion learned from this study is that it is almost impossible to derive scientifically precise and unequivocal information about process and outcome parameters in septic orthopaedic surgery from current hospital documentation systems. Detailed assessment of patients’ charts is necessary to obtain clinically relevant data, and to abstract the individual course from initial presentation over surgical procedures to discharge and follow-up.Regarding the subsample of patients with infected fracture-fxation devices, both the presence of staphylococci as well as systemic treatment with fluoroquinolones and rifampicin for about 30 days predicted the risk of reinfection, although the sample size and study design did not allow for robust conclusions. Because of the small sample size, the final model also may have been saturated.Answering the important question whether prolonged suppressive systemic antimicrobial treatment reduces the risk of reinfection clearly demands a multicenter RCT. This, however, needs to be conducted under EMA (European Medicines Agency), FDA (US Food and Drug Administration), and other international pharmaceutical regulations, with major requirements on trial logistics. Assuming a baseline risk of infection of 5% for any anatomical site, fracture severity, soft tissue compromise and so on, two-sided type I and II errors of 2% (accounting for multiple testing) and 15% (including a power reserve), respectively, a trial aiming at demonstrating a relative risk reduction of 50% by prolonged  over shorter systemic antimicrobial treatment must recruit about 2 × 1400 patients, depending on the preferred adaptive design, number of interim analyses, strata etc. One may also think of a non-inferiority trial demonstrating that shorter systemic antibiotic treatment  is not inferior to longer application with regard to infection relapse. This will, however, demand even higher sample sizes. We call for a European initiative to investigate the optimal duration of systemic antibiotic therapy for patients with fracture-fixation-device-associated infections undergoing revision surgery. This may, apart from standardizing diagnostic, peri-operative, surgical, and aftercare protocols, identify the most effective empiric systemic antibiotic regimen for patients suffering from deep SSI, namely device-related infections, adhering to the principles of antibiotic stewardship.In summary, up to 31 days of systemic exposure to fluoroquinolones and / or rifampicin appear to lower the risk of reinfection after surgical revision for infected extramedullary fracture-fixation constructs, although present results are compatible with chance. A large-scale confirmatory trial is needed to confirm that prolonged systemic suppressive antibiotic therapy is more effective than shorter administration in reducing reinfections, or that shorter treatment is not inferior to prolonged exposure in achieving this endpoint.


Cardiac resynchronization therapy (CRT) is an established treatment in patients with heart failure and prolonged QRS duration where a biventricular pacemaker is implanted to achieve faster activation and more synchronous contraction of the left ventricle (LV). Despite the convincing effect of CRT, 30–40% of patients do not respond. Among the most important correctable causes of non-response to CRT is non-optimal LV lead position.We will enroll 122 patients in this patient-blinded and assessor-blinded, randomized, clinical trial aiming to investigate if implanting the LV lead guided by electrical mapping towards the latest LV activation as compared with imaging-guided implantation, causes an excess increase in left ventricular (LV) ejection fraction (LVEF). The patients are randomly assigned to either the intervention group: preceded by cardiac computed tomography of the cardiac venous anatomy, the LV lead is placed according to the latest LV activation in the coronary sinus (CS) branches identified by systematic electrical mapping of the CS at implantation and post-implant optimization of the interventricular pacing delay; or patients are assigned to the control group: placement of the LV lead guided by cardiac imaging. The LV lead is targeted towards the latest mechanical LV activation as identified by echocardiography and outside myocardial scar as identified by myocardial perfusion (MP) imaging. The primary endpoint is change in LVEF at 6-month follow up (6MFU) as compared with baseline measured by two-dimensional echocardiography. Secondary endpoints include relative percentage reduction in LV end-systolic volume, all-cause mortality, hospitalization for heart failure, and a clinical combined endpoint of response to CRT at 6MFU defined as the patient being alive, not hospitalized for heart failure, and experiencing improvement in NYHA functional class or/and > 10% increase in 6-minute walk test.We assume an absolute increase in LVEF of 12% in the intervention group versus 8% in the control group. If an excess increase in LVEF can be achieved by LV lead implantation guided by electrical mapping, this study supports the conduct of larger trials investigating the impact of this strategy for LV-lead implantation on clinical outcomes in patients treated with CRT.NCT02346097. Registered on 12 January 2015.ClinicalTrials.gov, Patients were enrolled between 16 February 2015 and 13 December 2017.The online version of this article (10.1186/s13063-018-2930-y) contains supplementary material, which is available to authorized users. Cardiac resynchronization therapy (CRT) improves survival, symptoms, and left ventricular (LV) function in patients with medical refractory heart failure and prolonged QRS duration –4. NeverPotentially correctable causes of non-response to CRT are LV lead positioning and device programming , 8. GuidAn alternative approach for individualized LV lead placement is to target the myocardial region with the latest electrical activation; a strategy with the advantage of electrical measurements being immediately available during the implant procedure. Retrospective studies have documented an association between pacing the LV in a region with late electrical activation and improved outcome after CRT , 13. HowRecently, electrical resynchronization with narrowing of the QRS width during CRT has been associated with better outcome . FurtherTo clarify the potential value of an electrically guided strategy for optimizing CRT response, we designed a prospective, double-blinded, randomized trial comparing an electrically guided CRT strategy with an imaging-guided approach. We hypothesize that an electrically guided CRT strategy improves CRT response by optimal electrical resynchronization targeting LV lead placement towards the region with the latest electrical activation combined with VVd optimization to achieve the narrowest biventricular paced QRS. The aim of the present study is to investigate if this strategy of optimal electrical resynchronization causes an excess improvement in LV ejection fraction (LVEF) as compared with an imaging-guided strategy positioning the LV lead according to the latest mechanically activated non-scarred myocardial segment.Intervention group  including pre-implant cardiac computed tomography (CT) to visualize cardiac venous anatomy, procedural electrical activation mapping of all available coronary sinus (CS) branches, placement of the LV lead to pace the site of latest electrical activation, and procedural VVd optimization to achieve the shortest possible QRS duration.82Rubidium positron emission tomography (Rb-PET)) to localize the LV myocardial scar. The LV lead is targeted towards the CS branch closest to the latest mechanically activated non-scarred segment and simultaneous biventricular stimulation is applied . Se. Se24]. After baseline clinical evaluation and pre-implant imaging, patients are allocated either to the intervention or the control group. Study data are recorded in a web-based case record form (CRF) with logging of all data entries. The CRF is also used for randomization using computerized permuted blocks of different sizes. Randomization is stratified according to ischemic or non-ischemic heart failure etiology. An external data manager is responsible for the CRF and has programmed a computerized random-number generator.Patients and physicians responsible for enrollment, baseline and follow-up clinical evaluation, including imaging acquisition, are blinded to the allocated treatment. Information about randomization is available only to the physician performing the implant. Data related to the device implantation, post-implant device-tests, and optimization are collected and entered into the CRF by the physicians performing the implantation and the dedicated research nurses, to ensure blinding of the investigator collecting clinical and imaging data. Information on the randomization code will be available when all patients have completed the 6MFU and all statistical analyses have been performed.Intervention group: prior to implantation fluoroscopic venography is co-registered to the CT venography to ensure visualization of all available CS branches. During the implantation procedure, systematic electrical activation mapping of all available epicardial veins is performed using the LV electrode and/or a specialized mapping guidewire . Simultaneous local LV electrograms (EGM) and 12-lead surface ECGs are acquired . The local electrical activation delay is measured as the time interval from QRS onset in the surface ECG to the maximum voltage change over time recorded in the EGM, reflecting the near-field activation of the myocardium according to the LV lead  [Immediately after the implantation, the VVd settings are programmed by the physician performing the implantation, to obtain the narrowest QRS width. This is performed by measuring QRS width as the maximal QRS duration in any lead in the 12-lead ECG recorded at five different VVd settings: (1) right ventricle (RV) stimulation 20 ms prior to LV stimulation, (2) simultaneous biventricular pacing, (3) LV stimulation 20 ms prior to RV stimulation, (4) LV stimulation 40 ms prior to RV stimulation, and (5) LV stimulation 60 ms prior to RV stimulation.Control group: prior to implantation the fluoroscopic venography is co-registered to the CT venography to visualize available CS branches. After combining information from echocardiography, Rb-PET, and cardiac CT, the LV electrode is targeted towards the CS branch closest to the latest mechanically activated non-scarred myocardial segment. Basal and mid-LV segments of the CS tributaries are prioritized separately according to the relation with basal and mid-LV segmental mechanical activation delay. CT images of cardiac venous anatomy are available to the physician performing the implantation in a 2D short-axis view and in 3D volume-rendered reconstructions. The CS tributary closest to the optimal LV pacing site is labeled as first priority for LV lead placement. Tributaries closest to the second, third, or fourth latest activated segment with viable myocardium are chosen as the second, third, or fourth priority .In the imaging group, the VVd is programmed to simultaneous biventricular stimulation. In both treatment groups, atrioventricular (AV) optimization is performed the day after implantation using the iterative method ensuring maximal separation of the E-wave and A-wave without termination of the A-wave .All-cause mortality.Hospitalization for heart failure.Implantation procedure time.Procedural radiation exposure.Device-related complications.Indices of dyssynchrony and association between dyssynchrony, LV lead placement, and response to CRT.Changes in QoL, NYHA functional class, 6MWT, N-terminal prohormone of brain natriuretic peptide (Nt Pro-BNP), QRS duration, LV end-diastolic volume (LVEDV), LVESV, LVEF, mechanical dyssynchrony, and LV lead parameters .The primary endpoint is absolute change in left ventricular ejection fraction (LVEF) from baseline to 6MFU measured by 2D echocardiography. Secondary outcomes include relative percentage reduction in LV end-systolic volume (LVESV) and a combined clinical outcome measure of response to CRT at 6MFU defined as the patient being alive, not hospitalized for heart failure, and experiencing an improvement in NYHA functional class or/and > 10% increase in 6MWT . HospitaWe hypothesize that the intervention group strategy will result in an excess increase in LVEF of 4% compared with the strategy used in the control group, where an 8% increase in LVEF is expected . To idenP value < 0.05 is considered significant.All analyses will be conducted according to the intention-to-treat principle and will be performed before breaking the randomization code. Baseline characteristics are presented and compared clinically. Primary and secondary endpoints will be analyzed using linear regression for continuous variables and logistic regression for binary outcome measures, including heart failure etiology as a variable in the model. Multivariate regression analysis will be reported for absolute change in LVEF including baseline LVEF, heart failure etiology, sex, and baseline QRS width as covariates. Predictors of missing outcome values will be identified by comparing baseline characteristics and will be included in a multivariate regression model for sensitivity analysis. Intraclass correlation coefficients are computed to assess intraobserver and interobserver agreement for the echocardiographic parameters included in the primary endpoint: LVEF, LVEDV, LVESV assessed for 20 echocardiograms. A two-sided Positioning of the LV lead according to the latest activated myocardial segment has been shown to be an important determinant of response to CRT. In this current study, the strategy is to target the myocardial region with the latest electrical activation. The advantage of this approach is that the electrical data obtained from mapping are readily available during the implant procedure without the need for alignment of imaging modalities to target a specific myocardial segment. Several observational studies indicate that a LV lead location in regions with late electrical activation is associated with improved clinical outcome and reverse remodeling , 13, 28.Randomized studies have demonstrated that targeting LV lead placement towards the latest mechanically activated non-scarred myocardial area as assessed by speckle-tracking echocardiography strain analysis improves clinical outcome and LV reverse remodeling compared with a routine anatomical approach targeting the non-apical posterolateral region , 11. SimDue to the superior outcome associated with the imaging-guided approach as compared with conventional LV lead placement –11, we aThe extent of myocardial scar tissue is inversely related to the response to CRT  and placPre-implant cardiac CT is applied to assess CS anatomy as potentially available CS tributaries may be missed during fluoroscopic balloon occlusive angiography and to ease planning implantation of the LV lead. Post-implant cardiac CT is performed to determine the final LV pacing site because fluoroscopy has been shown to be inaccurate and poorly reproducible for this purpose .Considering the complex design, this trial would be difficult to conduct as a multi-center study, and therefore it does not have statistical power to investigate differences between groups in “harder” endpoints such as survival or hospitalization due to heart failure. We chose LVEF as the primary endpoint, because it is a commonly used and universally understood echocardiographic measure of LV systolic function, which furthermore is a good predictor of survival in patients with CRT . AccordiWe acknowledge the inherent limitations of a single-center study design. Nevertheless, the double-blinded, randomized, controlled trial design for comparing two advanced strategies for CRT optimization is the strongest research instrument to investigate a difference in outcome caused by these interventions.We do not merge the applied imaging modalities and the procedural fluoroscopy in the control group. However, we use the standard myocardial segmentation  to ease The introduction of cardiac CT and Rb-PET prior to CRT will increase the patient’s cumulative radiation exposure. Several approaches to minimize radiation dose are applied in this study, including the use of iterative reconstruction algorithms, application of prospectively triggered high-pitch CT scans, individual settings of tube voltage and current, and the use of Rb-PET for MP imaging, respectively. Furthermore, the utility and potential benefits of participating in this study are expected to equalize the risks of exposure to ionizing radiation, possible adverse effects, and inconvenience to the patients.No randomized trial has investigated the effect of a CRT implant-strategy targeting optimal electrical resynchronization achieved by guiding LV lead placement to the myocardial region with the latest electrical activation combined with post-implant VVd optimization for narrowing the paced QRS width. If an excess increase in LVEF is achieved by LV lead implantation guided by systematic electrical mapping followed by VVd optimization for narrowing paced QRS, this study supports the conduct of larger, multicenter, randomized clinical trials investigating the impact of electrically guided LV lead implantation on clinical outcomes in patients treated with CRT.Trials before all patients were enrolled and before analyzing any data and breaking the randomization code.Patients were enrolled between 16 February 2015 and 13 December 2017. The current protocol article was submitted to Additional file 1:SPIRIT checklist of the ElectroCRT study protocol. (PDF 174 kb)


Nitrospira challenged not only the paradigm of labor division in nitrification, it also raises fundamental questions regarding the environmental distribution, diversity, and ecological significance of complete nitrifiers compared to canonical nitrifying microorganisms. Recent genomic and physiological surveys identified factors controlling their ecology and niche specialization, which thus potentially regulate abundances and population dynamics of the different nitrifying guilds. This review summarizes the recently obtained insights into metabolic differences of the known nitrifiers and discusses these in light of potential functional adaptation and niche differentiation between canonical and complete nitrifiers.Nitrification, the oxidation of ammonia via nitrite to nitrate, has been considered to be a stepwise process mediated by two distinct functional groups of microorganisms. The identification of complete nitrifying The online version of this article (10.1007/s00253-018-9486-3) contains supplementary material, which is available to authorized users. Additionally, nitrite and nitrate can be easily washed out from the soil matrix, and thus leach into the groundwater and aquatic ecosystems. The increased N availability in these systems causes a boost of productivity with tremendous consequences, including eutrophication of rivers and lakes, algal blooms, and formation of dead zones in coastal regions. In contrast, nitrification represents the initial N cycling step in biological wastewater treatment, where well-orchestrated microbial activities result in the removal of excess N compounds.Nitrification, the sequential aerobic oxidation of ammonia to nitrate via nitrite, is a central nitrogen (N) cycling process. On the one hand, nitrification depletes the pool of accessible ammonium, the best accessible N source for biomass production. On the other hand, the products of nitrification nitrite and nitrate are widely used electron acceptors. From an anthropogenic perspective, nitrification has starkly contrasting roles. It contributes to N loss from fertilized agricultural soils by producing nitrite and nitrate, two compounds that are rapidly reduced to N-containing gases, including the potent greenhouse gas nitrous oxide  the ecological significance of the comammox process, (ii) driving factors for niche separation between the different ammonia-oxidizing guilds, and (iii) the physiology of comammox compared to strict nitrite-oxidizing  II Fig. , comammoil Table . For PCRNitrospira rarely is the only nitrifying guild present in a habitat. This co-occurrence of comammox and canonical ammonia oxidizers indicates a potential functional differentiation between these microbial groups  initiates nitrification by oxidizing ammonia to hydroxylamine, a reaction that requires molecular oxygen for the activation of ammonia. In AOB, the intermediate hydroxylamine (NH2OH) is further oxidized by HAO, while AOA apparently lack a HAO homolog. Intriguingly, recent biochemical investigations of the purified HAO of Nitrosomonas europaea suggested that the product of hydroxylamine oxidation might be nitric oxide (NO) and not nitrite as assumed previously  cycle  that convert NO derived from nitrite reduction  to cytochrome P460 of N. europaea, a homologous gene is absent in most comammox genomes. Future physiological studies focusing on potential N2O production of complete nitrifiers are needed to determine their potential contribution to N2O emissions.Taken together, genomic surveys of complete nitrifiers suggest several metabolic differences between the nitrifying guilds that potentially shape microbial community composition in the environment. In addition, the observed high ammonia affinity and growth yield of the first comammox pure culture CO2 IPCC . CanonicNitrospira are similar, indicated by the low amount of comammox-specific genes detected by comparative genomics , the enzyme catalyzing nitrite oxidation, is conserved and highly similar in all Nitrospira genomes, the nitrite affinity of N. inopinata is around 50-fold lower than for canonical Nitrospira  the assimilatory ferredoxin-dependent nitrite reductase NirA and (ii) an octaheme cytochrome c (OCC) that potentially reduces nitrite to ammonia for assimilation  harbors a genomic region syntenic to this N metabolism gene cluster of canonical Nitrospira  and have been intensively studied in ies Fig.  as well ies Fig. . The twoses Fig.  and wherNitrospira can intracellularly generate ammonia from cyanate and/or urea degradation. While the known canonical Nitrospira possess a cyanase for decomposing cyanate into ammonia and CO2, all known complete nitrifiers seem to have lost this enzyme. Similarly, most canonical ammonia oxidizers lack the genetic repertoire for cyanate degradation except for the freshwater AOA Nitrososphaera gargensis  encoded upstream of the urease structural genes -hydrogenase maturation enzymes HypA and HypB compensate the lack of UreE  and anaerobic reduction of nitrate to nitrite in the presence of suitable electron donors H to maintain the cellular redox balance during fermentation  H2 evolution for maintaining the redox balance during anaerobic degradation of simple organic matter  and Nitrosomonas mobilis  might additionally catalyze nitrate reduction in the presence of suitable electron donors , including N. inopinata and Nitrospira sp. ND1


This article provides additional data on the application of early coagulation support protocol in the management of major trauma patients. Data come from a retrospective analysis reported in the article “Early coagulation support protocol: a valid approach in real-life management of major trauma patients. Results from two Italian centres” [1]. Data contain information about the relationship between differences in resource use and mortality outcomes, and patient demographic and clinical features at presentation. Furthermore, a comparison between resource consumption, the probability of multiple transfusions and the mortality outcomes among propensity-score matched patients is reported. Stratified analyses were performed including a study period patients' feature interaction in separated Poisson models and by formally testing the null hypothesis of equal efficacy of the ECS protocol among categories of patients through an F test.We defined “multiple transfused patients” as those experiencing four or more pRBC units during the first 24-h. The cut-off of four pRBC units represented the sample 75th percentile. We estimated the mean difference in transfused units and length of stay between ECS and pre-ECS from unadjusted Poisson models, using the delta methods to estimate the 95% CI for the mean difference. Findings were reinforced by replacing the Poisson model with a negative binomial distribution. In addition, we investigated the association between clinical features and the probability of multiple transfusion by means of univariate and multivariate logistic regression models.To further control for any residual difference in clinical features between pre-ECS and ECS, we compared resource consumption, the probability of multiple transfusions and the mortality outcomes among propensity-score matched patients. The propensity score included the following variables: age, sex, ISS, AIS head, abnormal systolic blood pressure, blood base excess, lactate, haemoglobin, and platelets at hospital admission. The propensity score matching was performed using a standard macro.All statistical analyses were performed using SAS 9.4 .


Optogenetic manipulation is uniquely useful in unraveling the functional organization of neuronal circuits in the central nervous system by enabling reversible gain- or loss-of-function of discrete populations of neurons within restricted brain regions. This state-of-the-art technology can produce circuit-specific neuromodulation by overexpressing light-sensitive proteins (opsins) in particular cell types of interest. Here, we discuss the principle of optogenetic manipulation and its application in pain research using animal models, and we also discuss how to potentially use optogenetic stimulation in the treatment of migraine headache in the future. Migraine headache is a common neurovascular disorder . DespiteOptogenetic manipulation can produce gain- or loss-of-function in specific type of cells following light application . The maiViral vectors have been shown to be very powerful in mediating widespread gene expression in the brain . Both le+) to flow into intracellular space to induce neuronal excitation when stimulated by blue light and conversely, the hyperpolarizing opsin eNpHR3.0, a chloride pump activated by yellow light, allows Cl- to flow into neurons to produce neuronal inhibition, it is possible to study the behavioral consequences of activating or inhibiting the same ensembles of neurons by expressing the two light-sensitive proteins on the same neurons [Optogenetic manipulation can produce circuit-specific neuromodulation by overexpressing light-sensitive proteins (opsins) in particular cell types of interest. This is accomplished either by the use of viral vectors that infect only certain types of neurons through cell type-specific promoters, such as calcium/calmodulin-dependent protein kinase IIα (CaMKIIα), which will localize opsins to excitatory neurons , or by t neurons . Stimulation frequency and duration are critical factors in optogenetic neuromodulation. A previous study reported that while low frequency of optogenetic stimulation increases the release of amino acid neurotransmitters, higher frequency of optogenetic stimulation increases the release of both amino acid neurotransmitters and neuropeptides . AnotherOptogenetic manipulation can be used to specifically regulate neuronal activity in neural circuits . CombineCurrently there are different types of devices for optogenetic stimulation, including classic and portable devices. The classic device needs to be implanted into stimulation sites, which could cause potential inflammation and nerve injury. The portable microdevice can be used for wireless light stimulation, which enables neuronal activity to be modulated noninvasively. The effect of optogenetic stimulation usually lasts for a short time period, thus repeated optical stimulation is likely necessary to produce analgesic-like effects. Optogenetic stimulation can be used to modulate nociceptive signaling remotely ,28. For Recently, optogenetic manipulation has also been used to modulate nociceptive signaling in freely behaving mice ,33. SeleAlthough electrical and magnetic neuromodulation techniques produce inhibitory effects on migraine headache, non-specific neuronal activation could compromise their effectiveness and may induce unnecessary side effects. Optogenetic manipulation can specifically modulate neuronal activity with spatial and temporal precision, thereby providing new insights into neural circuitry mechanisms underlying the analgesic effects produced by electrical and magnetic stimulation in the CNS. Furthermore, through either hyperpolarizing opsin-mediated neuronal inhibition of trigeminovascular sensory signaling or depolarizing opsin-mediated neuronal activation of endogenous analgesic system, optogenetic manipulation might be developed as a more efficient tool to treat migraine headache. The medial prefrontal cortex (mPFC) has been implicated in top-down control of sensory signaling and affective pain processing. Lee et al. reported that optogenetic activation of the mPFC produces strong anti-nociceptive effects in a rat model of persistent neuropathic pain ; that stCortical spreading depression (CSD) has been demonstrated to be an important mechanism by which migraine headache occurs with an aura . PreventOptogenetic stimulation is a powerful tool in unraveling neuronal circuits in the CNS. Combining this revolutionary technology with electrophysiological recording will enable us to investigate the central mechanisms underlying pain processing in animal models, which will provide significant insights for novel pain therapy development. Optogenetic manipulation-based circuit-specific neuromodulation approach could be developed into a new neuromodulation approach for the treatment of chronic pain including migraine headache. In the future, the stimulation parameters including frequency, duration and current intensity need to be optimized to obtain the maximal efficacy. Thus, more evaluations will be needed to fine-tune these parameters before we use optogenetic stimulation to treat patients with chronic pain including migraine headache in the clinic.


Neophron percnopterus majorensis). We focussed specifically on the role of individual characteristics and spatial constraints in shaping patterns of resource use. Using high-resolution GPS data obtained from 45 vultures tracked for 1 year, we show that individual vultures were repeatable in both their monthly use of predictable and semi-predicable resources (feeding station vs. farms) and monthly levels of mobility (home range size and flight activity). However, individual foraging activities were simultaneously characterized by a high degree of  plasticity in the use of the feeding station in specific months. Individual rank within dominance hierarchy revealed sex-dependent effects of social status on resource preference in breeding adults, illustrating the potential complex social mechanisms underpinning status-dependent resource use patterns. Our results show that predictable food at feeding stations may lead to broad-scale patterns of resource partitioning and affect both the foraging and social dynamics within local vulture populations.Despite increasing work detailing the presence of foraging specializations across a range of taxa, limited attention so far has been given to the role of spatiotemporal variation in food predictability in shaping individual resource selection. Here, we studied the exploitation of human-provided carrion resources differing in predictability by Canarian Egyptian vultures ( Such individual divergence in resource use may arise from phenotypic differences  and environmental constraints affecting foraging trade-offs1. As such, foraging specialisations are generally thought of as different foraging optimization strategies3. However, the extent to which the interplay between ecological conditions and individual resource preferences affects (or determine) population spatial dynamics remain poorly understood4.Foraging tactics are often highly plastic, allowing individuals to adaptively respond to spatial and temporal fluctuations in resource availability and environmental changes. Yet, despite plasticity in foraging, individuals of the same species typically tend to use only a subset of the resources available in the environment, often displaying distinct foraging specializations and/or dietary preferences3. Although temporal predictable food patches (pulsed resources) characterize most natural systems , the presence of anthropogenic food resource pulses  are increasingly impacting the natural dynamics of food supply, creating new ecological conditions upon which many animals base their foraging decisions6. Predictable food patches can greatly alter the costs and benefits of foraging, either by reducing the time and energy needed for food searching7 or by increasing levels of competition among individuals attracted to the same resource and hence, the costs associated with food acquisition9.A major determinant of individual foraging strategies is the spatial clumping and temporal predictability of resources, affecting decisions on patch choice, patch departure times and inter-patch movements10. While dominant individuals may be able to monopolize a large share of the food, there will always be some food available to lower-ranked individuals. For example, predictable food patches are often visited by individuals for which the costs of food searching may be high, such as young, inexperienced individuals or immigrants from other populations with limited knowledge of their environment11. Second, for territorial birds, central place foraging constraints during breeding may importantly affect the ability of making use of predictable food12. Such constraints may in turn differ among individuals depending on social rank if, for instance, the location of predictable food influences local territory quality14. Although there is increasing evidence that predictable anthropogenic resources are used by only a subset of the population, including seabirds17 and storks11, studies examining the potential trade-offs responsible for the asymmetric use of anthropogenic food are still scarce (but see11).While high levels of competition and interference at predictable food may lead to the exclusion of subordinate individuals from these resources, the mechanisms underlying the usage of locally superabundant food are likely more complex. First, the ‘economic defendability’ of this resource is typically low18) and, to a lower extent, on the surroundings of cattle farms . Despite concerns about the potential impact of such large feeding stations on the natural foraging habits and social structure of local vulture populations22, a mechanistic understanding of how the use of surplus food varies within and among individuals is still lacking. The extent to which changes in the spatial distribution and predictability of resources may influence behavioural processes key to understand spatial population dynamics therefore still remain poorly understood.European vultures currently rely on feeding stations (where abundant food is supplied on a regular basisNeophron percnopterus majorensis). Continuous monitoring has resulted in 90% of the birds  being ringed in 2016, 16% of them carrying GPS-transmitters (n = 45). Firstly, we described seasonal variation in the monthly use of food resources varying in their spatiotemporal predictability  and how vultures allocated their time into flight and non-flight behaviour. Next, we tested our main hypothesis that individual vultures differ in resource preferences as a result of trait-specific foraging optimization strategies. In a first step, we assessed whether individual vultures were repeatable in their preferences for food resources differing in predictability (farms vs. feeding stations) and levels of mobility (home range size and flight activity). Second, we specifically test whether birds preferring predictable food reduce their overall food searching activities  by analysing both within- and among-individual correlations between resource use and mobility. Finally, we examine whether predictable food is of higher value to dominant birds, owing to their superior competitive skills, by analysing the effects of individual rank within a dominance hierarchy, as well as sex, age, and territorial status. In addition, in territorial birds, we examine the role of spatial constraints in shaping individual resource use and patterns of mobility, by analysing how territory location (i.e. distance to predictable feeding sites) may affect resource use and ranging behaviour, again, in relation to individual traits.Here, we assessed individual plasticity and repeatability in the exploitation of food resources varying in predictability by a territorial, but highly social avian scavenger. We took advantage of a twenty-year research program on a closed island population of the endangered Canarian Egyptian vulture , farms  and the ratio feeding station: farms . Both measures of mobility were also individually repeatable: logKDE95 , and flight activity .There was significant among-individual variance in the intercepts  of the time spent at the central feeding station . Resource preference also varied according to age, with young birds spending more time at the central feeding station than farms compared to older birds , showing a positive and negative correlation respectively  and the pre-egg laying phase (Jan-Mar) compared to dominant individuals, but these differences disappeared during the remaining part of the year . In males, there was no relationship between dominance rank and distance between territory and the central feeding station  made consistent use of the feeding station throughout the year. By contrast, subdominant individuals  favoured farms as their main source of food, most likely because of reduced competition at these sites due to the unpredictable nature of food supply. These results demonstrate for the first time the asymmetric use of this widely used conservation tool in vultures, and point towards a major role of feeding stations in driving patterns of resource partitioning within populations.While feeding stations may have a profound impact on the foraging dynamics of local vulture populations24). Patterns of within-individual plasticity between resource use and ranging behaviour were most pronounced in birds breeding far away from the feeding station (mostly foraging at farms) making large-scale flights to the central feeding station. Thus, instead of searching for unpredictable carcasses at farms , these vultures may frequently leave their habitually exploited home range to visit the central feeding station (i.e. sometimes even including birds breeding on Lanzarote12). The temporal nature of these movements may be explained by birds facing various trade-offs: they may choose to forage at predictable feeding site in order to reduce food searching efforts, but face potentially higher levels of competition for food at this site compared to farms, while the energetic costs associated with large-scale movements to this site may be substantial. Indeed, the movement behaviour of vultures on Fuerteventura may be importantly shaped by “alisios” winds, the dominant northeast trade winds (with an average speed of 20 km/h) that are particularly strong during spring and summer25. In addition, time-displacement constraints may be particularly important for single-prey loaders such as Egyptian vultures, notably during chick rearing (May–July). Overall, these patterns point towards differences in foraging costs associated with territory distance to the feeding station, which at least in females seems associated with social status (see below).Importantly, vultures preferring farms did not necessarily have larger home-ranges compared to birds feeding mostly at the central feeding station, despite both traits being individually repeatable. By contrast, ranging behaviour and flight activity varied plastically within individuals as a function of the use of the central feeding station. This shows that all individuals may temporally increase their use of predictable food, indicating that the feeding station may serve an important function as a food insurance . Outside the breeding season, the absence of central place foraging tasks, as well as the probable lower availability of food, may drive low-ranked males to exploit predictable food at the central feeding stations, despite a high cost-benefit ratio of resource acquisition due to their low social position. As opposed to females, the despotic distribution of territories in males may be determined by the presence of high quality food dumps near farms  instead of distance to the feeding station. However, future studies should unravel the differential cost associated with foraging for natural vs. semi-unpredicatble resources and the role of farms in determing territory quality to fully understand rank-specific foraging trade-offs in males.In territorial females, resource preferences depended on the distance of the territory to the feeding station, with dominant birds breeding at closer distances and spending more time at this resource, and low-ranked birds breeding further away and, consequently, relying more on farms. This suggests that the location of territories with respect to predictable food may be the main mechanism shaping status-dependent resource use in this sex. More specifically, securing a territory close to the feeding station may be beneficial in terms of knowledge on the occurrence of food dumps, and reduced time-displacement costs during chick rearing, while at the same time, dominant birds have instant access to food provided at this site since they are able to push most other birds away from food. In contrast, high-ranked territorial males spent consistently more time at farms throughout the year, while low-ranked territorial males spent little time at both farms and feeding station while breeding, suggesting they may generally rely more on natural food resources . In fact, after breeding, large gatherings at the feeding station sometimes reaching up to 100 individuals, suggests that this site may also serve a function as a social meeting place .A complementary scenario may be that subdominant territorial males can specifically visit the feeding station to improve their social rank and/or to search for new partners , this difference may have resulted from the large-scale explorative movements made by these males during the breeding season. These movements, peaking around the egg-laying phase, seem to be aimed at collecting information about potential future recruitment sites37 more than being the result of social competition. Finally, younger birds preferred the feeding station over farms which, given the overall low social position of young birds, suggests that this preference for a more competitive environment seems better explained by their poor explorative skills and limited environmental knowledge11. Probably, this age-effect also accounts for the high variance observed in resource preference in non-territorial males.Furthermore, competitive asymmetries among individuals may not be the only individual factor explaining differences in resource use. First, the observed sex-specific resource preferences may also be linked to asymmetries in foraging-roles between males and females, which is common in sex-dimorphic birds of prey18. Future work, preferably by using food manipulation experiments, should unravel the exact influence of predictable food on sex-specific settlement patterns.Predictable feeding sites may attract a large number of birds typically consisting of a mixture of individuals facing different foraging trade-offs, including permanent , and temporal visitors . Apart from individual traits explaining resource use patterns, our findings point towards a major role of spatial constraints in shaping the use of predictable food resources. Sex-differences in competitive abilities and/or foraging roles may create scenarios whereby males and females may perceive the value of territories differently regarding the location of predictable food, leading to complex patterns of resource partitioning and specialization. Overall, these results show that feeding stations may have a substantial impact on the social dynamics of local vulture populations, an issue that has so far received limited attention38 or conversely, when feeding stations are situated in highly poisoned areas and are intended to serve as a poison-free place. For animals with a strong male- or female-based social structure, as is the case in many vulture species, feeding stations have the potential for driving asymmetric patterns of individual and/or sex-specific mortality within populations .Future analyses should reveal the extent to which the differential use of predictable food may influence survival rates and reproductive output, and may change the selective pressures operating within populations. Strong negative effects on fitness may potentially arise if feeding stations are supplied with carcasses from intensive livestock farms rich in veterinary drugs23. More detailed studies are needed to deepen out the effectiveness of surplus food in relation to the dietary breath of different vulture species, which may help to further fine-tune conservation efforts.Lastly, the strong decrease in the use of the central feeding station during the breeding season  suggest that vultures may switch to alternative carrion resource to feed their young and/or may generally include more natural carrion resources in their diet in periods of high abundance of such prey itemsTo summarize, our results show that the food predictability and distribution may be an important driver underlying resource specialisation in vultures, whereby competition for predictable surplus food may drive individual resource preferences. In this way, predictable food may importantly affect both the foraging and social dynamics of local vulture populations. However, our results also evidence that other poorly known sex-specific mechanisms are at play, opening new research avenues. Overall, our study highlights the need to take into account social rank differences when studying patterns of individual resource specialization in highly social species.40, but is currently classified as ‘critically endangered’ owing to severe population declines since the 20th century. Fuerteventura Island (1662 km²) is the stronghold of the population, which is home to 60 breeding pairs and has an estimated population size of about 300 individuals in 2016 (authors unpublished). Extensive fieldwork (ringing of nestling and trapping of adults) has resulted in over 90% of the individuals being individually marked in 2016.The Canarian Egyptian vulture is a sedentary and endemic long-lived scavenger occupying the eastern part of the Canarian Archipelago . The species was once abundant throughout the archipelago41. On Fuerteventura, the species heavily relies on human-provided carcases available at goat and sheep farms throughout the island  and feral pigeons (Columba livia)42.Egyptian vultures are facultative scavengers that forage solitary (or sometimes in couples). The species leads a vagrant but very social lifestyle prior to recruitment, but afterwards adults are much more solitary and territorial. Throughout the year, they may form large aggregations at places with an abundance of food and roosting often occurs communallywww.uva-bits.nl, University of Amsterdam, n = 26; e-obs, e-obs Digital Telemetry, Grünwald, Germany, n = 19) were attached to the bird using backpack harnesses. The total weight of the system varied between 31 g (UvABiTS) and 54 g (e-obs) (1.4–2.4% of the weight of the bird) which is assumed to be harmless to the individual43. In total, we used GPS-tracking data from 45 birds  and 21 males  collected over a 12-month period (October 2015– September 2016). GPS loggers were programmed to record locations every 1 to 5 minutes, but data were re-sampled to an interval of 10 minutes  to allow direct comparisons between individuals. Because of low-battery levels and/or poor satellite reception, intervals exceeding15 minutes were removed from the dataset. We only used GPS-fixes between sunrise and sunset. We included all months with continuous recording of GPS-locations, independent of downloading error . However, we excluded months for which we had incomplete logging data . We also excluded all movements made to the neighbouring Lanzarote island . In total, we had data available for 486 individual-month (994.179 fixes), comprising 12 months for 35 individuals and between 3 to 11 months for 10 individuals. The median percentage of time explained per month by GPS fixes was 94.8% .Vultures were captured with cannon-nets about 3 km away from the main feeding station in the centre of the island. GPS trackers . In total, we were able to retrieve the coordinates of 319 out of 437 farms (73%). Farms differed greatly in size . Our data included all farms with more than 500 animals (N = 67). Annual mortality rate of sheep and goats (including lambs) at farms is estimated at about 10% (see44). We described monthly variation in average time-budgets of all individuals (flight vs. non-flight behaviour), specifically detailing the time spent at resources differing in predictability in the non-flight category . See Fig. To construct monthly activity budgets we distinguished between time allocated to flight vs. non-flight behaviour (including resting and foraging) using a threshold ground speed 3 m.s see Fig . Non-fli45. Since we were interested in food searching behaviour and/or explorative movements, ranging behaviour was defined using the 95% kernel density estimate . We excluded all non-flight GPS fixes at the feeding stations, garbage dump and farms to improve the independence of our home range estimate. Since the use of a reference smoothing factor (href) led to unrealistic estimates of home ranges  using the fixed kernel contour method adehabitHR package, R version 3.0.348, corrected for chance of encounter and thus independent of group size or visiting rate, see Suppl. Mat. Text 49. Scores obtained from the total dataset were used  and August-September 2016 (post-breeding season). We noted all agonistic displacements between colour-ringed individuals around baits at the central feeding station (from a hide) between sunset and sunrise. In total, we observed 4593 displacements between 141 individuals that were involved in more than 20 displacements , including 40 birds fitted with GPS loggers . Rank scores for each individual were determined using David’s score . To test the significance of repeatability, we compared models with and without the random effect of bird ID using a likelihood ratio test LRT52.We conducted all statistical analyses using SAS 9.4 software . We used a three-step approach to analyse our data. First, to quantify individual differences in the use of predictable and semi-predictable resources and movement behaviour we tested for repeatable individual differences in resource use , resource preference  and mobility  and time spent flying ). All transformed response variables were scaled by the standard deviation and mean-centred. Repeatability (R) was calculated based on a null model without main effects , as the among-individual variance divided by the sum of the among-individual and the residual within-individual variance50. Significance of within-individual correlations was tested by comparing unconstrained models with models where the within-individual covariance was constrained to zero, again by applying an LRT test .Second, links between individual preferences for resources differing in predictability and mobility patterns were tested by analysing within- and between-individual correlations in monthly resource use, ranging behaviour and flight activity (based on average daily measurements) using bivariate mixed-effects modelsIn the last part of our analyses, we tested the effects of individual attributes and territory location on resource preferences and mobility (dependent variables). First, we fitted LMMs with bird ID as random effect and included month, sex , dominance rank, age (in years) and territorial status (yes or no) as fixed effects. Since exploratory analyses showed that resource use and patterns of mobility varied strongly across the year in a non-linear manner Fig. , we inclCapture, banding and monitoring of Egyptian vultures were conducted under permits and following the protocols approved by the Cabildo Insular de Fuerteventura and the Dirección General de Protección de la Naturaleza  and following the protocols approved by the Ethic Committee of CSIC (CEBA-EBD-12-56), in accordance with the approved guidelines.Supplementary information


We report the case of a 56-year-old man who presented with locally advanced giant condyloma acuminatum (Buschke-Löwenstein tumor) after approximately 15 years of neglect due to hospital phobia. Clinical examination showed an extensive, erosive, exophytic and cauliflower-like growth involving his suprapubic, external genitalia and perianal region. No inguinal or supraclavicular lymphadenopathy was detected clinically. Histological study revealed a papillomatous and acanthotic epithelium with ortho and parakeratosis and koilocyte cells suggestive of HPV infection. No signs of malignant transformation were noted. Radiological investigations consisted of a thoracic-abdominal-pelvic computed tomography scan which showed the localization of this tumor in the external genitalia, perineal and suprapubic region without any lymph nodes or distant metastases. The results of biochemical and serological investigations including HIV test were normal. After discussion among the oncologist, radiotherapist, pathologist and surgeon, the patient initially received chemoradiotherapy, followed by extensive local excision with average outcome. Buschke-Lowenstein tumor is a relatively rare sexually transmitted disease. It is a neoplasm of the anogenital region which has benign appearance on histopathology. It often grows over years in immunocompetent patients and can be highly destructive to local tissue. It carries a high recurrence rate and a significant potential for malignant transformation. Human papilloma virus (types 6 and 11) has been implicated as an etiologic agent for this tumor. Since this disease is rare and no controlled studies exist, radical excision of this anogenital lesion is generally recommended as the first line therapy and close vigilance and follow up are essential.


Accordingly, neural plasticity and activity patterns related to recovery are also occurring at the same regions. Recovery relies on plasticity in the periinfarct and homotopic contralesional regions and involves relearning to perform movements. Seeking evidence for a relearning mechanism following stroke, we found that rodents display many features that resemble classical learning and memory mechanisms. Compensatory relearning is likely to be accompanied by gradual shaping of these regions and pathways, with participating neurons progressively adapting cortico-striato-thalamic activity and synaptic strengths at different cortico-thalamic loops – adapting function relayed by the striatum. Motor cortex functional maps are progressively reinforced and shaped by these loops as the striatum searches for different functional actions. Several cortical and striatal cellular mechanisms that influence motor learning may also influence post-stroke compensatory relearning. Future research should focus on  Recovery following stroke requires locating reorganization processes in the brain where the necessary motor and sensory signals converge. Once located, descriptions of mechanisms for optimization can provide neural substrates for recovery. In the cortex and striatum, waves of growth inhibiting and promoting factors related to cellular and plastic changes are triggered by the lesion. Cellular death leads to homeostatic destabilization and to a subsequent process of repair leading to partial recovery of cellular function . CellulaStroke induces a permissive environment for axonal sprouting through growth-promoting proteins in the boundary zone to the ischemic core . The perwhere and how compensatory relearning occurs.To enhance stroke recovery, the interaction of fundamental interconnected areas of research - such as motor learning and endogenous plasticity mechanisms, urgently requires new and innovative approaches . It has how compensatory relearning occurs is the fluid nature of memories, with participating brain regions dynamically shifting over time  , 2002. TSuperficial cortical layers I/II also receive thalamo-cortical inputs and can control the activity of any neuron with apical dendrite ascending to layer I . InteresIn other words, in the rodent agranular motor cortex, asymmetrical thalamic projections target layers I, II/III and V  and layers II/III and V (from cerebellum)  . Indeed,In brief, at the output stage pyramidal cells integrate a complex cortical network to produce movement. Including abundant connections with the contralateral hemisphere. Plastic changes of callosal connections is thought as a mechanism underlying the physiological reorganization in the contralesional hemisphere following stroke . In manyARs  . As aforhow these cortico-thalamo-cortical loops act on neuroplasticity mechanisms, a better understanding of the in vivo interactions during compensatory relearning is necessary. Previous evidence of where these changes occur are abundant, for example skilled training increase: dendritic length and arborization in layer II/III and V motor neurons , where mGlu5R has the strongest expression  are expressed throughout the cortex  receptor subtypes , m2 (21.4%), m3 (7.7%), m4 (44.2%), and m5 (<1%) , which can exert multiple effects on cortical neurons depending on type of target cell, pre- or post-synaptic receptor localization and receptor subtype ; resultim5 (<1%) ; in addim5 (<1%)  and are m5 (<1%)   . Althougm5 (<1%) . Later, m5 (<1%) ; and tham5 (<1%) . Interesm5 (<1%) .1 receptors are expressed at superficial  and deep  layers  receptors are selectively expressed in different cortical layers. Motor cortex D) layers   layers . D2-recepression   are most present in cortical layers IV and V and the subtypes αl tissue   protein displays elevated expression in striosomes relative to the surrounding matrix +, reduced locomotion , which are ≈95% of all neurons in the rat striatum . The remrneurons .Cholinergic interneurons are only ≈1% of striatal cells, but their influence is significant due to large cell bodies and widespread axonal connections with MSNs. They receive scattered excitatory innervation mainly from thalamus and to a lesser extent from cortex, and inhibitory synapses from MSNs .Motor cortex cortico-striatal afferents to patch and matrix compartments are mostly from layer V and to a lesser extent from layers II/III and VI . DiffereActivation of MSNs results in GABA release to the principal MSNs projections: external/internal globus pallidus and substantia nigra  Figure . The strThe direct-pathway circuit is formed by striatonigral MSNs (dMSNs) that provides mainly inhibitory inputs to both GABAergic and dopaminergic cells in substantia nigra, which in turn send axons to motor nuclei of the thalamus . Direct-where these structural changes occur. For example, cortical lesions induce axonal sprouting in the denervated striatum . This implies that the precise relative timing and interval between presynaptic and postsynaptic action potentials determine the strength of striatal synaptic potentiation or depression . Albeit,2+ blockade of NMDARs. But, in pathological conditions, such as stroke, a single excitatory input can lead to the activation of striatal NMDARs due to the “pathological” removal of the magnesium block  and thalamo-striatal (low [CB1Rs]) afferents  and eCBs  dopamine neurotransmission acts in concert with several neurotransmitters to regulate cortical, thalamic and limbic excitatory inputs ; (2) areCortical and striatal circuits work together during the development of motor skills characterized in two phases. A ‘fast’ improvement of motor performance with rapid behavioral outcomes, which can be observed both within a single training session and across the first few sessions. And a ‘slow’ improvement that develops across sessions, with more moderate gains in performance that progress across multiple training sessions . During In the same line of thoughts, cortical motor representation changes do not contribute to the initial acquisition of motor skills – but represent the consolidation of motor skills that occur during the later ‘slow’ phase of learning . This suIn other words, if during this striatal ‘search’ task the rewiring does not elicit functional movements, the reward-related reinforcement is poor. Hence, this dysfunctional motor map should not consolidate and the striatal ‘search’ should continue. Recovery would rely on this parallel cortico-striatal processing until permanent and relevant changes are reinforced and stored intra-cortically. In search for spared/functional movements the striatal network attempts to integrate the remaining pieces of cortico-thalamic network. Callosal cortico-cortical connections from the contralesional homotopic motor cortex and crossed cortico-striatal connections help to direct and guide this changing network - in search for functional movements. In addition, thalamo-cortical loops relayed by the striatum have the flexibility needed for adaptation to imposed behavioral demands following motor skill training . StriataInterestingly, post-stroke, a relatively ‘fast’ behavioral motor recovery is followed by a plateau of ‘slow’ or absent recovery  results in loss of movement representations . A possiGiven the aforementioned positive role of rehabilitation during this early period of changed function, it is possible that learning mechanisms can tailor this neuronal reorganization and reconnection process. In the light of the motor learning school, this process of neuronal reorganization and reconnection could be described as a process of ‘rebuilding’ the motor engram/map to regain function - such as during consolidation/reconsolidation of motor memories.Indeed, previously consolidated motor memories can undergo a labile state upon reactivation. The reactivated motor memory can be modified through reconsolidation , 2016. IAbundant evidence of learning-like plasticity at both, close and remote regions, have been reported following stroke. For example, axonal sprouting within local projections, intra-cortical projections, long distance interhemispheric projections and cortico-striatal projections . These cRehabilitative experience may slowly shape these new connections in a constant process of consolidation-reconsolidation of motor memories. Given the complex and continuous nature of the rehabilitation stimulus, these processes would evolve and change continuously. In other words, the consolidation-reconsolidation process of motor memories would change throughout multiple trials. This is more challenging to understand compared to declarative or fear memories that often are treated as a single trial event. Despite these differences, the understanding that recovery/relearning of movements may share the same classic mechanisms involved in learning and memory opens a new venue of timed and focused interventions during rehabilitation. For example, the timed use of learning enhancing drugs before, during or after rehabilitation sections. Or, use of protein synthesis inhibitors upon reactivation of maladaptive motor programs, such as dysfunctional compensation or learned bad-use.upstream cortical commands (how to improve relearning.Optimization of stroke recovery focused on learning mechanisms should follow the same logic of previous learning and memory studies. The fact that the motor skill redevelops slower, across multiple trials, presents a challenge for preclinical studies on the mechanisms of post-stroke compensatory relearning . Recovercommands . The deecommands  and a pucommands . Rehabil5Rs agonists (Several cortical and striatal cellular mechanisms that influence motor learning may also influence post-stroke compensatory relearning, such as: mGluagonists , 5-HT reagonists , cholineagonists  and impragonists , dopaminagonists , selectiagonists , NMDARs agonists  and moduagonists .downstream must be secondary to this relearning process. For example, the importance of spinal cord (in site and downstream to the lesion. Despite the importance of the striatum to learning, evidence of striatal participation on stroke recovery is lacking. In addition, the majority of basic stroke research studies does not fully address the role of striatal lesions and mechanisms (If the motor recovery process is directly shaped by cortical-striatal-thalamic interactions, whatever changes nal cord  and red nal cord  plasticichanisms .In vivo recordings have changed the way we think about motor learning (where recovery occurs, to how it occurs. We suggest that unveiling how the recovery/relearning process occurs is like to take a walk on a well know path of motor learning. This path should remind us that neural activity and synaptic plasticity are constantly interacting, both at individual synapses and within neural circuits. Our challenge is to understand how they operate in a behaving brain to support post-stroke compensatory relearning.learning , motor rlearning  and senslearning . The mosGB wrote the manuscript and drawn the figures. CS reviewed 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.