I-Ag7 ß56/57 polymorphisms regulate non-cognate negative selection to CD4+ T cell orchestrators of type 1 diabetes.

Genetic susceptibility to type 1 diabetes is associated with homozygous expression of major histocompatibility complex class II alleles that carry specific beta chain polymorphisms. Why heterozygous expression of these major histocompatibility complex class II alleles does not confer a similar predisposition is unresolved. Using a nonobese diabetic mouse model, here we show that heterozygous expression of the type 1 diabetes-protective allele I-Ag7 ß56P/57D induces negative selection to the I-Ag7-restricted T cell repertoire, including beta-islet-specific CD4+ T cells. Surprisingly, negative selection occurs despite I-Ag7 ß56P/57D having a reduced ability to present beta-islet antigens to CD4+ T cells. Peripheral manifestations of non-cognate negative selection include a near complete loss of beta-islet-specific CXCR6+ CD4+ T cells, an inability to cross-prime islet-specific glucose-6-phosphatase catalytic subunit-related protein and insulin-specific CD8+ T cells and disease arrest at the insulitis stage. These data reveal that negative selection on non-cognate self-antigens in the thymus can promote T cell tolerance and protection from autoimmunity.

A temporal thymic selection switch and ligand binding kinetics constrain neonatal Foxp3+ Treg cell development.

The neonatal thymus generates Foxp3+ regulatory T (tTreg) cells that are critical in controlling immune homeostasis and preventing multiorgan autoimmunity. The role of antigen specificity on neonatal tTreg cell selection is unresolved. Here we identify 17 self-peptides recognized by neonatal tTreg cells, and reveal ligand specificity patterns that include self-antigens presented in an age- and inflammation-dependent manner. Fate-mapping studies of neonatal peptidyl arginine deiminase type IV (Padi4)-specific thymocytes reveal disparate fate choices. Neonatal thymocytes expressing T cell receptors that engage IAb-Padi4 with moderate dwell times within a conventional docking orientation are exported as tTreg cells. In contrast, Padi4-specific T cell receptors with short dwell times are expressed on CD4+ T cells, while long dwell times induce negative selection. Temporally, Padi4-specific thymocytes are subject to a developmental stage-specific change in negative selection, which precludes tTreg cell development. Thus, a temporal switch in negative selection and ligand binding kinetics constrains the neonatal tTreg selection window.

Development of a novel sensitive single-tube nested PCR assay for the detection of African swine fever virus.

African swine fever (ASF) is a highly fatal and contagious viral disease caused by African swine fever virus (ASFV). It has caused significant economic losses to the swine industry and poses a serious threat to food security worldwide. Diagnostic tests with high sensitivity are essential for the effective management of ASF. Here, we describe a single-tube nested PCR (STN-PCR) assay for the detection of ASFV in which two consecutive amplification steps are carried out within a single tube. Two pairs of primers (outer and inner) were designed to target the p72 gene of ASFV. The primer concentrations, annealing temperatures, and number of amplification cycles were optimized to ensure the consecutive utilization of outer and inner primer pairs during amplification while minimizing the likelihood of amplicon contamination. In comparison with two conventional endpoint PCR assays (one of which is recommended by the World Organization for Animal Health), the newly developed STN-PCR assay demonstrated a 100-fold improvement in the limit of detection (LOD), detecting 100 copies of ASFV genomic DNA, whereas the endpoint PCR assays could detect no fewer than 10,000 copies. The clinical performance of the STN-PCR assay was validated using 95 tissue samples suspected of being positive for ASFV, and the assay showed 100% specificity. A Cohen's kappa value of 0.91 indicated perfect agreement between the assays. This new STN-PCR assay is a potentially valuable tool that will facilitate the control of ASF.

Direct benefit transfer for nutritional support of patients with TB in India-analysis of national TB program data of 3.7 million patients, 2018-2022.

BACKGROUND: Patients with TB have additional nutritional requirements and thus additional costs to the household. Ni-kshay Poshan Yojana(NPY) is a Direct Benefit Transfer (DBT) scheme under the National Tuberculosis Elimination Programme(NTEP) in India which offers INR 500 monthly to all notified patients with TB for nutritional support during the period of anti-TB treatment. Five years after its implementation, we conducted the first nationwide evaluation of NPY. METHODS: In our retrospective cohort study using programmatic data of patients notified with TB in nine randomly selected Indian states between 2018 and 2022, we estimated the proportion of patients who received at least one NPY instalment and the median time to receive the first instalment. We determined the factors associated (i) with non-receipt of NPY using a generalised linear model with Poisson family and log link and (ii) with time taken to receive first NPY benefit in 2022 using quantile regression at 50th percentile. RESULTS: Overall, 3,712,551 patients were notified between 2018 and 2022. During this period, the proportion who received at least one NPY instalment had increased from 56.9% to 76.1%. Non-receipt was significantly higher among patients notified by private sector (aRR 2.10;2.08,2.12), reactive for HIV (aRR 1.69;1.64,1.74) and with missing/undetermined diabetic status (aRR 2.02;1.98,2.05). The median(IQR) time to receive the first instalment had reduced from 200(109,331) days in 2018 to 91(51,149) days in 2022. Patients from private sector(106.9;106.3,107.4days), those with HIV-reactive (103.7;101.8,105.7days), DRTB(104.6;102.6,106.7days) and missing/undetermined diabetic status (115.3;114,116.6days) experienced longer delays. CONCLUSIONS: The coverage of NPY among patients with TB had increased and the time to receipt of benefit had halved in the past five years. Three-fourths of the patients received at least one NPY instalment, more than half of whom had waited over three months to receive the first instalment. NTEP has to focus on timely transfer of benefits to enable patients to meet their additional nutritional demands, experience treatment success and avoid catastrophic expenditure.

Radiology resident competency in detecting basilar artery occlusion: a simulation-based assessment.

PURPOSE: Basilar artery strokes are rare but can have characteristic imaging findings that can often be overlooked. This retrospective study aims to assess radiology residents' ability to identify CT imaging findings of basilar artery occlusion in a simulated call environment. METHODS: The Wisdom in Diagnostic Imaging Emergent/Critical Care Radiology Simulation (WIDI SIM)-a tested and reliable computer-aided emergency imaging simulation-was employed to assess resident readiness for independent radiology call. The simulations include 65 cases of varying complexity, including normal studies, with one case specifically assessing basilar artery stroke. Residents were presented with a single, unique case of basilar artery occlusion in two separate years of testing and were only provided with non-contrast CT images. Residents' free text responses were manually scored by faculty members using a standardized grading rubric, with errors subsequently classified by type. RESULTS: A total of 454 radiology residents were tested in two separate years on the imaging findings of basilar artery occlusion using the Wisdom in Diagnostic Imaging simulation web-based testing platform. Basilar artery occlusion was consistently underdiagnosed by radiology residents being tested for call readiness irrespective of the numbers of years in training. On average, only 14% of radiology residents were able to correctly identify basilar artery occlusion on non-contrast CT. CONCLUSIONS: Our findings underscore a potential gap in radiology residency training related to the detection of basilar artery occlusion, highlighting the potential need for increased educational efforts in this area.

An assessment of radiology resident competency in identifying suppurative retropharyngeal lymphadenitis: an examination using the WIDI SIM platform.

BACKGROUND AND PURPOSE: Suppurative retropharyngeal lymphadenitis is a retropharyngeal space infection almost exclusively seen in the young (4-8 years old) pediatric population. It can be misdiagnosed as a retropharyngeal abscess, leading to unnecessary invasive treatment procedures. This retrospective study aims to assess radiology residents' ability to independently identify CT imaging findings and make a definitive diagnosis of suppurative retropharyngeal lymphadenitis in a simulated call environment. MATERIALS AND METHODS: The Wisdom in Diagnostic Imaging Emergent/Critical Care Radiology Simulation (WIDI SIM) is a computer-aided emergency imaging simulation proven to be a reliable method for assessing resident preparedness for independent radiology call. The simulation included 65 cases across various imaging modalities of varying complexity, including normal studies, with one case specifically targeting suppurative retropharyngeal adenitis identification. Residents' free text responses were manually scored by faculty members using a standardized grading rubric, with errors subsequently classified by type. RESULTS: A total of 543 radiology residents were tested in three separate years on the imaging findings of suppurative retropharyngeal lymphadenitis using the Wisdom in Diagnostic Imaging simulation web-based testing platform. Suppurative retropharyngeal lymphadenitis was consistently underdiagnosed by radiology residents being tested for call readiness irrespective of the numbers of years in training. On average, only 3.5% of radiology residents were able to correctly identify suppurative retropharyngeal lymphadenitis on a contrast-enhanced computed tomography (CT). CONCLUSIONS: Our findings underscore a potential gap in radiology residency training related to the accurate identification of suppurative retropharyngeal lymphadenitis, highlighting the potential need for enhanced educational efforts in this area.

Analysis of decarbonization measures for the Indian Cement Sector.

Cement is one of the widely used materials in construction, and its production is both energy- and emission-intensive, contributing significantly to industrial emissions. This study investigates multiple methods for reducing emissions in the Indian cement sector based on the mass and energy balances of a representative cement plant. A novel methodology for calculating the overall emissions reduction per tonne of cement with multiple emission reduction measures and their interdependencies is proposed. The effect of captive power plants in the cement industry on emissions reduction is also considered. The results are depicted using an emission abatement curve, which gives the CO2 abatement cost against cumulative emission reduction per tonne of cement, and a cost premium curve, which shows the cumulative abatement cost against percentage abatement. The analysis shows that up to 30% emissions reduction is possible using existing emission reduction measures in all the cases considered with no additional cost, and near-zero emission reduction is only possible with the adoption of emerging technologies such as carbon capture and storage. The proposed methodology is the first to explore the impact of multiple measures for emission reduction on a given cement plant, allowing for a realistic estimate of emission reduction from the measures implemented.

Novel helix loop-mediated isothermal amplification (HAMP) assay for colorimetric detection of Staphylococcus aureus in milk.

Staphylococcus aureus is an important and leading cause of foodborne diseases worldwide. Prompt detection and recall of contaminated foods are crucial to prevent untoward health consequences caused by S. aureus. Helix loop-mediated isothermal amplification (HAMP) is an exciting recent addition to the array of available isothermal-based nucleic acid amplification techniques. This study aimed to develop and evaluate a HAMP assay for detecting S. aureus in milk and milk products. The assay is completed in 75 minutes of isothermal temperature incubation (64 ˚C) and dye-based visual interpretation of results based on colour change. The specificity of the developed assay was ascertained using 27 S. aureus and 17 non S. aureus bacterial strains. The analytical sensitivity of the developed HAMP assay was 9.7 fg/µL of pure S. aureus DNA. The detection limit of the HAMP assay in milk (86 CFU/mL) was 1000x greater than the routinely used endpoint PCR (86 × 103 CFU/mL). The practicality of applying the HAMP assay was also assessed by analysing milk and milk product samples (n = 95) obtained from different dairy farms and retail outlets. The developed test is a more rapid, sensitive, and user-friendly method for the high-throughput screening of S. aureus in food samples and may therefore be suitable for field laboratories. To our knowledge, this is the first study to develop and evaluate the HAMP platform for detecting S. aureus.

Development and evaluation of a novel polymerase spiral reaction based testing technique for same-day visual detection of Campylobacter coli in pork.

The developed polymerase spiral reaction-based technique specifically amplified the ceuE gene of C. coli and involved a three-step centrifugation method for DNA extraction. PSR, real-time and end-point PCR were able to detect 62 fg, 620 fg and 6.2 pg C. coli DNA/tube, respectively. PSR detection limits for artificially contaminated pork samples without enrichment, with 12 h enrichment and after 24 h enrichment were 1000 CFU/g, 100 CFU/g, and 10 CFU/g samples, respectively which were ten times better than real-time PCR. The detection performance of PSR (with 12 h enrichment) was also compared to culture (ISO10272-1:2017) method using 75 naturally-contaminated samples, which revealed the sensitivity, specificity, PPV, NPV and accuracy of 100% (95%CI, 73.2%-100%), 98.4% (95%CI, 90%-99.9%), 93.3% (95%CI, 66%-99.6%), 100% (95%CI, 92.5%-100%) and 98.7% (95%CI, 92.8%-99.9%), respectively. The advantage and novelty of this assay are its equipment-free nature, dye-based interpretation by the naked eye, and the requirement of one enzyme and one primer pair. This assay could be a better alternative to other molecular methods and may help in reducing the possible troubles (e.g., gastroenteritis, hospitalization, or death) of belated detection of C. coli in food products. This is the primary report applying the PSR for C. coli detection.

Prevalence, toxinotyping, antimicrobial susceptibility and biofilm-forming ability of Clostridium perfringens isolated from free-living rodents and shrews.

BACKGROUND AND OBJECTIVES: Clostridium perfringens (C. perfringens), is a spore-forming and toxin-producing pathogenic Gram-positive rod-shaped bacterium with immense public health/zoonotic concern. Rodents are well-known reservoirs and vectors for a large number of zoonoses and strong links have been recognized between synanthropic rodents and foodborne disease outbreaks throughout the world. To date, no study has been conducted for studying the prevalence of C. perfringens in rodents and shrews. In this study, we investigated faecal samples from free-living rodents and shrews trapped in Meghalaya, a North-eastern hill state of India for the presence of virulent and antimicrobial-resistant C. perfringens. METHODS: A total of 122 animals comprising six species of rodents and one species of shrews were trapped: Mus musculus (n = 15), Mus booduga (n = 7), Rattus rattus (n = 9), Rattus norvegicus (n = 3), Bandicota indica (n = 30), Bandicota bengalensis (n = 32) and Suncus murinus (n = 26). The faecal swabs were collected and processed for the isolation of C. perfringens. Toxinotyping was done using PCR. Antimicrobial susceptibility testing and biofilm forming ability testing were done using Kirby Bauer disc diffusion method and crystal violet assay. RESULTS: C. perfringens was isolated from 27 of the 122 faecal swabs (22.1%), from six species of rodents and shrews. Five of the host species were rodents, Bandicota bengalensis (25%), Bandicota indica (16.7%), Rattus norvegicus (33.3%), Mus musculus (13.3%), Mus booduga (42.8%) and Suncus murinus (shrew) (29.6%). The common toxinotype was type A (59.2%) followed by Type A with beta2 toxin (33.3%), Type C (3.7%) and Type C with beta2 toxin (3.7%). None of the isolates harboured cpe, etx, iap, and NetB genes and therefore none was typed as either B, D, E, F, or G. Nine isolates (33.3%) turned out to be multi-drug resistant (MDR), displaying resistance to three or more categories of antibiotics tested. Twenty-three out of twenty-seven isolates (85.2%) were forming biofilms. CONCLUSION: Globally, this is the first study to report the prevalence of C. perfringens and its virulence profile and antimicrobial resistance in free-living rodents and shrews. The rodents and shrews can potentially contaminate the food and environment and can infect humans and livestock with multi-drug resistant/virulent Type A and Type C C. perfringens.

Development of novel visual detection methodology for Salmonella in meat using saltatory rolling circle amplification.

AIM: The aim of this study was to develop a saltatory rolling circle amplification (SRCA) assay for rapid, simple and visual detection of Salmonella in meat. METHODS AND RESULTS: Saltatory rolling circle amplification assay was established using simple PCR primers targeting the invA gene of Salmonella enterica. The specificity of the SRCA assay was determined using 28 Salmonella and 15 non-Salmonella strains. The analytical sensitivity of the developed SRCA, conventional and real-time PCR assays were 70 fg, 7 pg and 700 fg S. enterica DNA per tube, respectively. The limit of detection (LoD) of the SRCA assay was 40 CFU per gram of meat without enrichment and 4 CFU per gram after including 6 h brief enrichment step. The detection limits of 40 CFU per gram and 4 CFU per gram of meat were achieved within 165 min and 9 h, respectively (including DNA extraction). To assess the real-world relevance of the SRCA assay, it was used to screen Salmonella from the field pork samples (n = 82). The same samples were also tested with culture (ISO 6579: 2002) method, conventional and real-time PCR assays. Using the developed assay with 6-h enrichment step, it could give accurate results as that of the culture method. CONCLUSIONS: The results of this study showed that the SRCA assay is a rapid, simple, sophisticated equipment-free and user-friendly method for accurate detection of Salmonella in meat foods. To our information, this is the first study to deploy SRCA assay for screening foods for Salmonella. SIGNIFICANCE AND IMPACT OF THE STUDY: The developed SRCA assay is cost-effective, easy-to-perform and equipment-free; therefore, it has the potential to replace other molecular detection methods for regular screening of Salmonella in foods in field laboratories.

Tobacco use among college students in Kerala, India.

Background & objectives: Despite tobacco use among college students being a major health concern, data remain sparse from India. It is in this background that this study aimed to report the prevalence of tobacco use and its psychosocial correlates among college students in the State of Kerala, India. Methods: A total of 5784 students from 58 colleges from Ernakulam district, Kerala, selected by cluster random sampling and were provided with self-administered questionnaire. In addition to socio-demographic profile, the questionnaire incorporated alcohol, smoking, and substance involvement screening test (ASSIST, for assessing tobacco use and its severity, lifetime use of other substances); Kessler's scale (psychological distress) and Barkeley's scale (attention deficit hyperactivity disorder symptoms). Screening questions were used for assessing lifetime suicidality and sexual abuse. Results: The lifetime prevalence of tobacco use was 8.6 per cent (21.5% males and 1.4% female). Among users, hazardous and dependent use defined using ASSIST scores was 63.3 and 2.9 per cent, respectively. Tobacco use was associated with older age, being male, urban residence, having a part-time job, use of alcohol and illicit drugs and academic failures. Interpretation & conclusions: Although the prevalence of tobacco use in our study was relatively low, the proportionately higher rates of hazardous use and its association with the negative correlates suggest that more needs to be done to prevent its deleterious consequences.

Rate of resident recognition of nonaccidental trauma: how well do residents perform?

BACKGROUND: A resident working under the entrustable professional activity of a graduated independent coverage model must identify nonaccidental trauma and notify clinicians of this concern to facilitate potential removal of the child from harm. The resident's role in identifying child abuse has not previously been studied. OBJECTIVE: The purpose of this study was to assess radiology residents' ability to identify radiographic imaging findings of nonaccidental trauma in a simulated call environment. MATERIALS AND METHODS: The Wisdom in Diagnostic Imaging Emergent/Critical Care Radiology Simulation (WIDI SIM) is a strategically designed computer-aided simulation of an emergency imaging experience that has been rigorously tested and proven to be a reliable means for assessing resident preparedness to competently and independently cover radiology call. The residents are provided with 65 cases of varying difficulty, including normal studies. Those cases include ones that require the resident to accurately identify skeletal findings of nonaccidental trauma. The residents respond using free text that is then scored manually by faculty members utilizing a robust grading rubric. Missed cases are then categorized by observation error and/or interpretative errors. RESULTS: A total of 675 radiology residents were given a case of nonaccidental trauma using the WIDI simulation web-based test platform between 2014 and 2017. Child abuse was consistently underdiagnosed by radiology residents being tested for call readiness irrespective of the numbers of years in training. Correct diagnostic score averages per year ranged from 10% to 79%. In year 1, 71% of residents correctly diagnosed nonaccidental trauma with a total of 101 participants. In year 2, 130 residents participated with only 20% answering correctly. In year 3, there were 201 participants with 79% correctly diagnosing nonaccidental trauma. In year 4, only 10% of 243 residents accurately diagnosed nonaccidental trauma. Residents from various stages of training were tested. Cases used with leading histories provided, accounted for a higher correct call rate. CONCLUSION: Radiology residency programs may be deficient in teaching residents to accurately recognize and report child abuse. This deficiency has potential implications for programs where a radiology attending is not present after hours as it raises the concern that child abuse may be missed by residents taking independent call. These data further question whether graduating radiologists are competent to recognize nonaccidental trauma and demonstrates the need for additional mandatory training during radiology residency.

A role for differential variable gene pairing in creating T cell receptors specific for unique major histocompatibility ligands.

A limited set of T cell receptor (TCR) variable (V) gene segments are used to create a repertoire of TCRs that recognize all major histocompatibility complex (MHC) ligands within a species. How individual αßTCRs are constructed to specifically recognize a limited set of MHC ligands is unclear. Here we have identified a role for the differential pairing of particular V gene segments in creating TCRs that recognized MHC class II ligands exclusively, or cross-reacted with classical and nonclassical MHC class I ligands. Biophysical and structural experiments indicated that TCR specificity for MHC ligands is not driven by germline-encoded pairwise interactions.Rather, identical TCRß chains can have altered peptide-MHC (pMHC) binding modes when paired with different TCRα chains. The ability of TCR chain pairing to modify how V region residues interact with pMHC helps to explain how the same V genes are used to create TCRs specific for unique MHC ligands.

Impact of oxygen therapy algorithm on oxygen usage in the emergency department.

BACKGROUND: Although oxygen is one of the oldest drugs available, it is still one of the most inappropriately administered drugs leading to over utilization of this very expensive resource. MATERIALS AND METHODS: This prospective observational study was done in a large emergency department (ED) in India. The pattern of oxygen usage was studied before and after the strict implementation of an oxygen treatment algorithm. The algorithm was taught to all doctors and nurses and its implementation was monitored regularly. The main outcome measures were proportion of patients receiving oxygen therapy, inappropriate usage, and avoidable direct medical cost to the patient. RESULTS: The 3-week pre-protocol observation phase in April 2016 included 3769 patients and the 3-week post-protocol observation phase in April 2017 included 4608 patients. The baseline demographic pattern was similar in both the pre-protocol and post-protocol groups. After the strict implementation of the algorithm, the number of patients receiving oxygen therapy decreased from 9.63% to 4.82%, a relative decrease of 51.4%. The average amount of total oxygen used decreased from 55.4 liters per person in pre-protocol group to 42.1 liters per person in the post-protocol group with a mean difference of 13.28 (95% CI 5.30-21.26; P = 0.001). Inappropriate oxygen usage decreased from 37.2% to 8.6%. There was a significant decrease in inappropriate oxygen use for indications like low sensorium (60.8% vs 21.7%) and trauma (88.5% vs 15.8%). The mortality rate in the pre-protocol phase was 2.7% as compared with 3.2% in the post-protocol phase. The total duration of inappropriate oxygen usage significantly decreased from 987 h to 89 h over the 21-day study period. CONCLUSION: The implementation of an oxygen therapy algorithm significantly reduces inappropriate oxygen use and decreases treatment cost to the patient with no additional mortality risk.

A synaptic basis for paracrine interleukin-2 signaling during homotypic T cell interaction.

T cells slow their motility, increase adherence, and arrest after encounters with antigen-presenting cells (APCs) bearing peptide-MHC complexes. Here, we analyzed the cell-cell communication among activating T cells. In vivo and in vitro, activating T cells associated in large clusters that collectively persisted for >30 min, but they also engaged in more transient interactions, apparently distal to APCs. Homotypic aggregation was driven by LFA-1 integrin interactions. Ultrastructural analysis revealed that cell-cell contacts between activating T cells were organized as multifocal synapses, and T cells oriented both the microtubule-organizing complex and interleukin-2 (IL-2) secretion toward this synapse. T cells engaged in homotypic interactions more effectively captured IL-2 relative to free cells. T cells receiving paracrine synaptic IL-2 polarized their IL-2 signaling subunits into the synaptic region and more efficiently phosphorylated the transcription factor STAT5, likely through a synapse-associated signaling complex. Thus, synapse-mediated cytokine delivery accelerates responses in activating T cells.

What is the value of reactive case detection in malaria control? A case-study in India and a systematic review.

BACKGROUND: Reactive case detection (RCD) for malaria is a strategy to identify additional malaria infections in areas of low malaria transmission and can complement passive surveillance. This study describes experiences with RCD in two Indian sites, and aimed to synthesize experiences with RCD across endemic countries. METHODS: RCD programmes were piloted in two urban areas of India with a low prevalence of mainly Plasmodium vivax malaria in 2014. Cases were identified in a clinic by microscopy and contacts were screened within 2 weeks; PCR, in addition to microscopy, was used to detect Plasmodium parasites. A systematic review was conducted to identify RCD experiences in the literature. RESULTS: In Chennai, 868 contacts were enrolled for 18 index cases of clinical malaria; in Nadiad, 131 contacts were enrolled for 20 index cases. No new malaria infections were detected in Nadiad among contacts, and four new infections were detected in Chennai (three P. vivax and one Plasmodium falciparum), of which two were among household members of index cases. An additional five studies describing results from an RCD strategy were identified in the literature: four in Africa and one in Thailand. Including the results from India, the average number of contacts screened per index case in a total of seven studies ranged from four to 50, and 126 in a case study in Thailand with one index case. Malaria was detected in 0-45 % of the contacted persons. The average number of index cases needed to be traced to find one new case of malaria ranged from one to five, and could not be assessed in one study in India (no contacts positive for 20 cases). Sharing the household with an index case was associated with a five-fold increased risk of malaria compared to contacts from households without an index case (pooled risk ratio 5.29, 95 % CI 3.31-8.47, I(2) 0 %, four studies). CONCLUSIONS: RCD in areas of low malaria transmission is a labour-intensive strategy, and its benefit is not clear. Studies are needed to assess how RCD can be optimized or into alternatives where interventions are targeted to family members or hotspots.

Effect of CDR3 sequences and distal V gene residues in regulating TCR-MHC contacts and ligand specificity.

The mature T cell repertoire has the ability to orchestrate immunity to a wide range of potential pathogen challenges. This ability stems from thymic development producing individual T cell clonotypes that express TCRs with unique patterns of Ag reactivity. The Ag specificity of TCRs is created from the combinatorial pairing of one of a set of germline encoded TCR Vα and Vß gene segments with randomly created CDR3 sequences. How the amalgamation of germline encoded and randomly created TCR sequences results in Ag receptors with unique patterns of ligand specificity is not fully understood. Using cellular, biophysical, and structural analyses, we show that CDR3α residues can modulate the geometry in which TCRs bind peptide-MHC (pMHC), governing whether and how germline encoded TCR Vα and Vß residues interact with MHC. In addition, a CDR1α residue that is positioned distal to the TCR-pMHC binding interface is shown to contribute to the peptide specificity of T cells. These findings demonstrate that the specificity of individual T cell clonotypes arises not only from TCR residues that create direct contacts with the pMHC, but also from a collection of indirect effects that modulate how TCR residues are used to bind pMHC.

Relapsing-remitting central nervous system autoimmunity mediated by GFAP-specific CD8 T cells.

Multiple sclerosis (MS) is an inflammatory disease of the CNS that causes the demyelination of nerve cells and destroys oligodendrocytes, neurons, and axons. Historically, MS has been thought to be a CD4 T cell-mediated autoimmune disease of CNS white matter. However, recent studies identified CD8 T cell infiltrates and gray matter lesions in MS patients. These findings suggest that CD8 T cells and CNS Ags other than myelin proteins may be involved during the MS disease process. In this article, we show that CD8 T cells reactive to glial fibrillary acidic protein (GFAP), a protein expressed in astrocytes, can avoid tolerance mechanisms and, depending upon the T cell-triggering event, drive unique aspects of inflammatory CNS autoimmunity. In GFAP-specific CD8 TCR-transgenic (BG1) mice, tissue resident memory-like CD8 T cells spontaneously infiltrate the gray matter and white matter of the CNS, resulting in a relapsing-remitting CNS autoimmunity. The frequency, severity, and remissions from spontaneous disease are controlled by the presence of polyclonal B cells. In contrast, a viral trigger induces GFAP-specific CD8 T effector cells to exclusively target the meninges and vascular/perivascular space of the gray and white matter of the brain, causing a rapid, acute CNS disease. These findings demonstrate that the type of CD8 T cell-triggering event can determine the presentation of distinct CNS autoimmune disease pathologies.

Breast Cancer Disparities: A Multicenter Comparison of Tumor Diagnosis, Characteristics, and Surgical Treatment in China and the U.S.

BACKGROUND AND OBJECTIVE: Incidence of and mortality rates for breast cancer continue to rise in the People's Republic of China. The purpose of this study was to analyze differences in characteristics of breast malignancies between China and the U.S. METHODS: Data from 384,262 breast cancer patients registered in the U.S. Surveillance, Epidemiology, and End Results (SEER) program from 2000 to 2010 were compared with 4,211 Chinese breast cancer patients registered in a Chinese database from 1999 to 2008. Outcomes included age, race, histology, tumor and node staging, laterality, surgical treatment method, and reconstruction. The Pearson chi-square and Fisher's exact tests were used to compare rates. RESULTS: Infiltrating ductal carcinoma was the most common type of malignancy in the U.S. and China. The mean number of positive lymph nodes was higher in China (2.59 vs. 1.31, p < .001). Stage at diagnosis was higher in China (stage IIA vs. I, p < .001). Mean size of tumor at diagnosis was higher in China (32.63 vs. 21.57 mm). Mean age at diagnosis was lower in China (48.28 vs. 61.29 years, p < .001). Moreover, 2.0% of U.S. women underwent radical mastectomy compared with 12.5% in China, and 0.02% in China underwent reconstructive surgery. CONCLUSION: Chinese women were diagnosed at younger ages with higher stage and larger tumors and underwent more aggressive surgical treatment. Prospective trials should be conducted to address screening, surgical, and tumor discrepancies between China and the U.S. IMPLICATIONS FOR PRACTICE: Breast cancer patients in China are diagnosed at later stages than those in America, which might contribute to different clinical management and lower 5-year survival rate. This phenomenon suggests that an earlier detection and treatment program should be widely implemented in China. By comparing the characteristics of Chinese and Chinese-American patients, we found significant differences in tumor size, lymph nodes metastasis, and age at diagnosis. These consequences indicated that patients with similar genetic backgrounds may have different prognoses due to the influence of environment and social economic determinates.