Probing the Role of Protein Surface Charge in the Activation of PrfA, the Central Regulator of Listeria monocytogenes Pathogenesis

Listeria monocytogenes is a food-borne intracellular bacterial pathogen capable of causing serious human disease. L. monocytogenes survival within mammalian cells depends upon the synthesis of a number of secreted virulence factors whose expression is regulated by the transcriptional activator PrfA. PrfA becomes activated following bacterial entry into host cells where it induces the expression of gene products required for bacterial spread to adjacent cells. Activation of PrfA appears to occur via the binding of a small molecule cofactor whose identity remains unknown. Electrostatic modeling of the predicted PrfA cofactor binding pocket revealed a highly positively charged region with two lysine residues, K64 and K122, located at the edge of the pocket and another (K130) located deep within the interior. Mutational analysis of these residues indicated that K64 and K122 contribute to intracellular activation of PrfA, whereas a K130 substitution abolished protein activity. The requirement of K64 and K122 for intracellular PrfA activation could be bypassed via the introduction of the prfA G145S mutation that constitutively activates PrfA in the absence of cofactor binding. Our data indicate that the positive charge of the PrfA binding pocket contributes to intracellular activation of PrfA, presumably by facilitating binding of an anionic cofactor

Why Is Aging a Risk Factor for Cognitive Impairment in Parkinson's Disease?—A Resting State fMRI Study

Using resting-state functional MRI (rsfMRI) data of younger and older healthy volunteers and patients with Parkinson's disease (PD) with and without mild cognitive impairment (MCI) and applying two different analytic approaches, we investigated the effects of age, pathology, and cognition on brain connectivity. When comparing rsfMRI connectivity strength of PD patients and older healthy volunteers, reduction between multiple brain regions in PD patients with MCI (PD-MCI) compared with PD patients without MCI (PD-non-MCI) was observed. This group difference was not affected by the number and location of clusters but was reduced when age was included as a covariate. Next, we applied a graph-theory method with a cost-threshold approach to the rsfMRI data from patients with PD with and without MCI as well as groups of younger and older healthy volunteers. We observed decreased hub function (measured by degree and betweenness centrality) mainly in the medial prefrontal cortex (mPFC) in older healthy volunteers compared with younger healthy volunteers. We also found increased hub function in the posterior medial structure (precuneus and the cingulate cortex) in PD-non-MCI patients compared with older healthy volunteers and PD-MCI patients. Hub function in these posterior medial structures was positively correlated with cognitive function in all PD patients. Together these data suggest that overlapping patterns of hub modifications could mediate the effect of age as a risk factor for cognitive decline in PD, including age-related reduction of hub function in the mPFC, and recruitment availability of the posterior medial structure, possibly to compensate for impaired basal ganglia function

Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Interaction Testing and Polygenic Risk Scoring to Estimate the Association of Common Genetic Variants with Treatment Resistance in Schizophrenia

Importance: About 20% to 30% of people with schizophrenia have psychotic symptoms that do not respond adequately to first-line antipsychotic treatment. This clinical presentation, chronic and highly disabling, is known as treatment-resistant schizophrenia (TRS). The causes of treatment resistance and their relationships with causes underlying schizophrenia are largely unknown. Adequately powered genetic studies of TRS are scarce because of the difficulty in collecting data from well-characterized TRS cohorts. Objective: To examine the genetic architecture of TRS through the reassessment of genetic data from schizophrenia studies and its validation in carefully ascertained clinical samples. Design, Setting, and Participants: Two case-control genome-wide association studies (GWASs) of schizophrenia were performed in which the case samples were defined as individuals with TRS (n = 10501) and individuals with non-TRS (n = 20325). The differences in effect sizes for allelic associations were then determined between both studies, the reasoning being such differences reflect treatment resistance instead of schizophrenia. Genotype data were retrieved from the CLOZUK and Psychiatric Genomics Consortium (PGC) schizophrenia studies. The output was validated using polygenic risk score (PRS) profiling of 2 independent schizophrenia cohorts with TRS and non-TRS: a prevalence sample with 817 individuals (Cardiff Cognition in Schizophrenia [CardiffCOGS]) and an incidence sample with 563 individuals (Genetics Workstream of the Schizophrenia Treatment Resistance and Therapeutic Advances [STRATA-G]). Main Outcomes and Measures: GWAS of treatment resistance in schizophrenia. The results of the GWAS were compared with complex polygenic traits through a genetic correlation approach and were used for PRS analysis on the independent validation cohorts using the same TRS definition. Results: The study included a total of 85490 participants (48635 [56.9%] male) in its GWAS stage and 1380 participants (859 [62.2%] male) in its PRS validation stage. Treatment resistance in schizophrenia emerged as a polygenic trait with detectable heritability (1% to 4%), and several traits related to intelligence and cognition were found to be genetically correlated with it (genetic correlation, 0.41-0.69). PRS analysis in the CardiffCOGS prevalence sample showed a positive association between TRS and a history of taking clozapine (r2 = 2.03%; P =.001), which was replicated in the STRATA-G incidence sample (r2 = 1.09%; P =.04). Conclusions and Relevance: In this GWAS, common genetic variants were differentially associated with TRS, and these associations may have been obscured through the amalgamation of large GWAS samples in previous studies of broadly defined schizophrenia. Findings of this study suggest the validity of meta-analytic approaches for studies on patient outcomes, including treatment resistance

Global health training among U.S. residency specialties: a systematic literature review

Background: Interest in global health training during residency is increasing. Global health knowledge is also becoming essential for health-care delivery today. Many U.S. residency programs have been incorporating global health training opportunities for their residents. We performed a systematic literature review to evaluate global health training opportunities and challenges among U.S. residency specialties. Methods: We searched PubMed from its earliest dates until October 2015. Articles included were survey results of U.S. program directors on global health training opportunities, and web-based searches of U.S. residency program websites on global health training opportunities. Data extracted included percentage of residency programs offering global health training within a specialty and challenges encountered. Results: Studies were found for twelve U.S. residency specialties. Of the survey based studies, the specialties with the highest percentage of their residency programs offering global health training were preventive medicine (83%), emergency medicine (74%), and surgery (71%); and the lowest were orthopaedic surgery (26%), obstetrics and gynecology (28%), and plastic surgery (41%). Of the web-based studies, the specialties with the highest percentage of their residency programs offering global health training were emergency medicine (41%), pediatrics (33%), and family medicine (22%); and the lowest were psychiatry (9%), obstetrics and gynecology (17%), and surgery (18%). The most common challenges were lack of funding, lack of international partnerships, lack of supervision, and scheduling. Conclusion: Among U.S. residency specialties, there are wide disparities for global health training. In general, there are few opportunities in psychiatry and surgical residency specialties, and greater opportunities among medical residency specialties. Further emphasis should be made to scale-up opportunities for psychiatry and surgical residency specialties

Assessment of Minimum Inhibitory Concentrations of Telavancin by Revised Broth Microdilution Method in Phase 3 Hospital-Acquired Pneumonia/Ventilator-Associated Pneumonia Clinical Isolates

<p>Article full text</p> <p>The full text of this article can be found <b><a href="https://link.springer.com/article/10.1007/s40121-016-0133-y">here.</a></b></p> <p>Provide enhanced content for this article</p> <p>If you are an author of this publication and would like to provide additional enhanced content for your article then please contact <a href="http://www.medengine.com/Redeem/”mailto:[email protected]”"><b>[email protected]</b></a>.</p> <p>The journal offers a range of additional features designed to increase visibility and readership. All features will be thoroughly peer reviewed to ensure the content is of the highest scientific standard and all features are marked as ‘peer reviewed’ to ensure readers are aware that the content has been reviewed to the same level as the articles they are being presented alongside. Moreover, all sponsorship and disclosure information is included to provide complete transparency and adherence to good publication practices. This ensures that however the content is reached the reader has a full understanding of its origin. No fees are charged for hosting additional open access content.</p> <p>Other enhanced features include, but are not limited to:</p> <ul> <li>Slide decks</li> <li>Videos and animations</li> <li>Audio abstracts</li> <li>Audio slides</li> </ul

Ceftobiprole Medocaril Is an Effective Post-Exposure Treatment in the Fischer 344 Rat Model of Pneumonic Tularemia

Francisella tularensis subspecies tularensis is a category-A biothreat agent that can cause lethal tularemia. Ceftobiprole medocaril is being explored as a medical countermeasure for the treatment of pneumonic tularemia. The efficacy of ceftobiprole medocaril against inhalational tularemia was evaluated in the Fischer 344 rat model of infection. The dose was expected to be effective against F. tularensis isolates with ceftobiprole minimum inhibitory concentrations ≤0.5 µg/mL. Animals treated with ceftobiprole medocaril exhibited a 92% survival rate 31 days post-challenge, identical to the survival of levofloxacin-treated rats. By comparison, rats receiving placebo experienced 100% mortality. Terminally collected blood, liver, lung, and spleen samples confirmed disseminated F. tularensis infections in most animals that died prior to completing treatments (placebo animals and a rat treated with ceftobiprole medocaril), although levels of bacteria detected in the placebo samples were significantly elevated compared to the ceftobiprole-medocaril-treated group geometric mean. Furthermore, no evidence of infection was detected in any rat that completed ceftobiprole medocaril or levofloxacin treatment and survived to the end of the post-treatment observation period. Overall, survival rates, body weights, and bacterial burdens consistently demonstrated that treatment with ceftobiprole medocaril is efficacious against otherwise fatal cases of pneumonic tularemia in the rat model

Integrating traditional practices and social network visualization to prevent substance use: study protocol for a randomized controlled trial among urban Native American emerging adults

BackgroundNonmedical use of prescription opioids (defined as taking opioid medications for hedonic effects or in a manner other than prescribed) and the use of heroin have emerged in recent years as major public health concerns in the United States. Of particular concern is the prevalence of opioid use among emerging adults (ages 18-25), as this is a developmental period of heightened vulnerability and critical social, neurological, and psychological development. Data from 2015 show that American Indian/Alaska Native (AI/AN) people have the highest rates of diagnosis for opioid use disorders (OUDs). One recent study found that the overdose death rate among urban-dwelling AI/AN individuals was 1.4 times higher compared to those living in rural areas. To date, there are no evidence-based prevention programs addressing opioid use among urban AI/AN emerging adults that integrate culturally-appropriate strategies with evidence-based treatment. Traditions and Connections for Urban Native Americans (TACUNA) builds on our prior work with AI/AN communities across California to develop and evaluate culturally appropriate programming to address opioid, alcohol, and cannabis use among urban AI/AN emerging adults.Methods/designIn a randomized controlled trial, 18-25&nbsp;year old urban AI/AN emerging adults will receive either TACUNA (n = 185), which comprises three virtual workshops utilizing motivational interviewing, social network visualization, and integrating traditional practices and a wellness circle, or one virtual culturally sensitive opioid education workshop (n = 185). We will evaluate intervention effects on primary outcomes of frequency of opioid, alcohol, and cannabis use, as well as secondary outcomes of social network characteristics and cultural connectedness, over a 12-month period.DiscussionThis project has the potential to expand the range and effectiveness of opioid, alcohol, and cannabis services for urban AI/AN emerging adults by addressing the opioid epidemic and use of other substances at both the community and individual level. In addition, it provides important culturally grounded conceptual and practical information to advance the field of substance use interventions and enhance resiliency among this population.Trial registrationClinicalTrials.gov Identifier: NCT04617938. Registered October 26, 2020 https://clinicaltrials.gov/ct2/show/record/NCT04617938