Role of Artificial Intelligence (AI) in Patient Education and Communication in Dentistry.

Effective patient education and communication are integral components of quality dental care, contributing to informed decision-making, treatment compliance, and positive clinical outcomes. However, traditional methods face challenges such as language barriers, anxiety, and information retention issues. Artificial intelligence (AI) presents innovative solutions to enhance patient engagement and communication in dentistry. This review explores the transformative role of AI in redefining patient education and communication strategies, focusing on applications, benefits, challenges, and future directions. A literature search identified articles from 2018 to 2024, encompassing empirical evidence and conceptual frameworks related to AI in dental patient engagement and communication. Key findings reveal AI's potential to offer personalized educational materials, virtual consultations, language translation tools, and virtual reality simulations, improving patient understanding and experience. Despite advancements, concerns about overreliance, accuracy, implementation costs, patient acceptance, privacy, and regulatory compliance persist. Future implications suggest AI's ability to track patient progress, analyze feedback, streamline administrative processes, and provide ongoing support, enhancing oral health outcomes. However, ethical, regulatory, and equity considerations require attention for responsible AI deployment and widespread adoption. Overall, AI holds promise for revolutionizing dental patient education, communication, and care delivery, emphasizing the need for comprehensive strategies to address emerging challenges and maximize benefits.

Unraveling the genetics of heat tolerance in chickpea landraces (Cicer arietinum L.) using genome-wide association studies.

Chickpea, being an important grain legume crop, is often confronted with the adverse effects of high temperatures at the reproductive stage of crop growth, drastically affecting yield and overall productivity. The current study deals with an extensive evaluation of chickpea genotypes, focusing on the traits associated with yield and their response to heat stress. Notably, we observed significant variations for these traits under both normal and high-temperature conditions, forming a robust basis for genetic research and breeding initiatives. Furthermore, the study revealed that yield-related traits exhibited high heritability, suggesting their potential suitability for marker-assisted selection. We carried out single-nucleotide polymorphism (SNP) genotyping using the genotyping-by-sequencing (GBS) method for a genome-wide association study (GWAS). Overall, 27 marker-trait associations (MTAs) linked to yield-related traits, among which we identified five common MTAs displaying pleiotropic effects after applying a stringent Bonferroni-corrected p-value threshold of <0.05 [-log10(p) > 4.95] using the BLINK (Bayesian-information and linkage-disequilibrium iteratively nested keyway) model. Through an in-depth in silico analysis of these markers against the CDC Frontier v1 reference genome, we discovered that the majority of the SNPs were located at or in proximity to gene-coding regions. We further explored candidate genes situated near these MTAs, shedding light on the molecular mechanisms governing heat stress tolerance and yield enhancement in chickpeas such as indole-3-acetic acid-amido synthetase GH3.1 with GH3 auxin-responsive promoter and pentatricopeptide repeat-containing protein, etc. The harvest index (HI) trait was associated with marker Ca3:37444451 encoding aspartic proteinase ortholog sequence of Oryza sativa subsp. japonica and Medicago truncatula, which is known for contributing to heat stress tolerance. These identified MTAs and associated candidate genes may serve as valuable assets for breeding programs dedicated to tailoring chickpea varieties resilient to heat stress and climate change.

The Role of Chatbot GPT Technology in Undergraduate Dental Education.

This comprehensive article explores the transformative role of Chatbot GPT, based on the GPT-3 architecture, in revolutionizing dental education. The focus is on its impact across various facets, including personalized learning pathways, integration into virtual patient simulation scenarios, 24/7 accessibility, multilingual support, interactive dental dictionary functionality, evidence-based learning, and assessment and evaluation of dental students. The objective is to showcase how Chatbot GPT enhances educational experiences, promotes inclusivity, and aligns with contemporary pedagogical principles. Chatbot GPT emerges as a powerful ally in dental education, offering personalized learning experiences, risk-free clinical simulations, continuous accessibility, multilingual support, instant terminology assistance, evidence-based learning resources, and real-time assessment capabilities. Its adaptability caters to diverse learning needs, fostering a learner-centered approach and promoting lifelong learning for both dental students and practitioners. As a versatile tool, Chatbot GPT not only transforms the educational journey but also serves as a valuable asset for continuous professional development in the dynamic landscape of dentistry.

A Multi-Model Based Stability Analysis Employing Multi-Environmental Trials (METs) Data for Discerning Heat Tolerance in Chickpea (Cicer arietinum L.) Landraces.

Identifying a congenially targeted production environment and understanding the effects of genotype by environmental interactions on the adaption of chickpea genotypes is essential for achieving an optimal yield stability. Different models like additive main effect and multiplicative interactions (AMMI 1, AMM2), weighted average absolute scores of BLUPs (WAASB), and genotype plus genotype-environment (GGE) interactions were used to understand their suitability in the precise estimation of variance and their interaction. Our experiment used genotypes that represent the West Asia-North Africa (WANA) region. This trial involved two different sowing dates, two distinct seasons, and three different locations, resulting in a total of 12 environments. Genotype IG 5871(G1) showed a lower heat susceptibility index (HSI) across environments under study. The first four interactions principal component axis (IPCA) explain 93.2% of variations with significant genotype-environment interactions. Considering the AMMI stability value (ASV), the genotypes IG5862(G7), IG5861(G6), ILC239(G40), IG6002(G26), and ILC1932(G39), showing ASV scores of 1.66, 1.80, 2.20, 2.60, and 2.84, respectively, were ranked as the most stable and are comparable to the weighted average absolute scores of BLUPs (WAASB) ranking of genotypes. The which-won-where pattern of genotype plus genotype-environment (GGE) interactions suggested that the target environment consists of one mega environment. IG5866(G10), IG5865(G9), IG5884(G14), and IG5862(G7) displayed higher stability, as they were nearer to the origin. The genotypes that exhibited a superior performance in the tested environments can serve as ideal parental lines for heat-stress tolerance breeding programs. The weighted average absolute scores of BLUPs (WAASB) serve as an ideal tool to discern the variations and identify the stable genotype among all methods.

A Comparison of the Outcomes Between Suprapatellar and Infrapatellar Approaches of Intramedullary Interlock Nailing in Patients With Extra-Articular Tibial Fractures.

Background and objective Intramedullary nailing can be considered the current gold standard for the treatment of diaphyseal tibial fractures. Nailing ensures good fracture stability, protection against malalignment, and quick mobilization. The suprapatellar (SP) approach of tibial nailing in the semi-extended position has recently been recommended as a safe and effective surgical technique; it has been gaining significant attention in the orthopedic literature, with fewer complications and reoperations. The approach has been shown to facilitate a reduction in fractures around the knee joint in the semi-extended position, and the extended position of the lower leg allows for easier fluoroscopic imaging. In this study, we aimed to compare the outcomes between SP and infrapatellar (IP) approaches of intramedullary nailing in patients with extra-articular tibial fractures. Method A randomized control trial was conducted over a period of 1.5 years at our tertiary care hospital after obtaining approval from its institutional ethics committee. A total of 60 patients with extra-articular tibial fractures were included in the study, with 30 patients each in the SP nailing group and the IP nailing group, based on randomized sampling and with the help of radiological exposure in SP and IP nailing as per a previous study. The groups were then compared in terms of KUJALA patellofemoral knee score, operative time, radiation exposure, and time of union. Results When comparing both groups, those treated with the SP approach had better outcomes, including reduced radiation exposure, less pain, decreased operative time, better KUJALA patellofemoral knee score, and faster union.  Conclusion Based on our findings of the comparison between SP and IP nailing approaches of extra-articular tibial fractures, the former leads to better and safer outcomes than the latter.

Outcomes of Osteosynthesis Versus Hemiarthroplasty in Elderly Patients With Arbeitsgemeinschaft Fur Osteosynthesefragen-Orthopedic Trauma Association (AO-OTA) 31A2 Hip Fractures.

Background Intertrochanteric femur fractures account for more than half of the cases of hip fractures. These injuries are among the most common fractures in elderly individuals. Elderly patients suffer from other comorbidities such as diabetes mellitus or hypertension and are prone to low surgical tolerance with increased postoperative morbidity and mortality. Although the ideal choice of treatment for intertrochanteric femur fractures in the elderly remains debatable, the use of hemiarthroplasty in elderly patients provides an early mobilization and decreased postoperative morbidity. In this study, we aimed to assess the functional outcomes of bipolar hemiarthroplasty and osteosynthesis in Arbeitsgemeinschaft Fur Osteosynthesefragen-Orthopedic Trauma Association (AO-OTA) 31A2 hip fractures using the Harris Hip Score. Methodology A total of 60 elderly patients with AO/OTA 31A2 hip fractures were divided into two groups and treated with bipolar hemiarthroplasty and osteosynthesis using proximal femoral nail (PFN). Functional scores were assessed at two months, four months, and six months postoperatively using the Harris Hip Score. Results The mean age of the patients was 73.03 ± 7.57 years in the study. The majority of the patients were females, 38 (63.33%), with 18 females in the osteosynthesis group and 20 females in the hemiarthroplasty group. The average operative time was 144.93 ± 9.76 minutes in the hemiarthroplasty group and 86.07 ± 11 minutes in the osteosynthesis group. Blood loss was 263.67 ± 42.95 mL in the hemiarthroplasty group and 84.5 ± 15.05 mL in the osteosynthesis group. The average Harris Hip Score at two months, four months, and six months was 64.77 ± 4.33, 72.67 ± 3.54, and 79.72 ± 2.53, respectively, for the hemiarthroplasty group and 57.83 ± 2.83, 64.13 ± 3.89, and 72.83± 3.89, respectively, for the osteosynthesis group (p < 0.001 for all follow-up scores). One death was encountered in the hemiarthroplasty group. Other complications included superficial infection noted in two (6.67%) patients in both groups. There was one episode of hip dislocation in the hemiarthroplasty group. Conclusions The use of bipolar hemiarthroplasty in intertrochanteric femur fractures in elderly patients can prove to be better in comparison to osteosynthesis, but the use of osteosynthesis can be effective for patients who cannot tolerate major blood loss and longer surgical times.

ISP Good Clinical Practice Recommendations for the management of Dentin Hypersensitivity.

Dentin hypersensitivity (DH) is a rising concern in clinical dentistry that causes pain and discomfort and negatively affects the quality of life of patients. Indian Society of Periodontology conducted a nationwide survey, involving 3000 dentists in December 2020, which revealed significant knowledge gaps regarding DH, viz., under-diagnosis, incorrect differential diagnosis, and treatment strategies/recommendations for the management of DH patients in daily clinical practice. The current paper has been envisioned and conceptualized to update the practicing Indian dentists regarding the so-called enigma of dentistry "Dentin Hypersensitivity," based on the best available contemporary evidence. An expert panel was constituted comprising 30 subject experts from across the country, which after extensive literature review and group discussions formulated these recommendations. The panel advocated routine screening of all dentate patients for exposed dentin areas and DH to avoid under-diagnosis of the condition and suggested an early preventive management. Consensus guidelines/recommendations for the use of desensitizing agents (DAs) at home, including the use of herbal agents, are also provided within the backdrop of the Indian context. The guidelines recommend that active management of DH shall be accomplished by a combination of at home and in-office therapies, starting with the simplest and cost-effective home use of desensitizing toothpastes. A diagnostic decision tree and a flowchart for application in daily practice are designed to manage the patients suffering from DH or presenting with exposed dentin areas in dentition. Various treatment methods to manage DH have been discussed in the paper, including the insights from previously published treatment guidelines. Further, a novel system of classification of DH patients based on specific case definitions has been developed for the first time. Explicit charts regarding the available treatment options and the chronology of institution of the agent, for the management in different case categories of DH, have been provided for quick reference. The management strategy takes into account a decision algorithm based on hierarchy of complexity of treatment options and intends to improve the quality of life of the patient by long-term maintenance with an innovatively defined triple C's or 3Cs approach.

In vitro Analysis of Surface Roughness Produced by an Air Polishing Device and Conventional Root Planing on Cementum: A Profilometric Study.

Context: Tooth surface polishing is an integral part of periodontal therapy. Enamel and cementum show a smooth surface clinically after debridement with the naked eye, but numerous surface irregularities can be detected microscopically. Air polishing is safe and effective when used by trained professionals. Aims: The aim of the study is to evaluate and compare the surface roughness of cementum by using an air polishing device and conventional root planing with hand instruments. Materials and Methods: A total of 45 extracted teeth stored in saline were divided into three groups randomly - Group A (conventional root planing), Group B (hand instrumentation and air polishing), and Group C (air polishing alone) - with 15 samples each. Samples were evaluated for surface roughness by using profilometer. Six parameters were checked for surface roughness. Statistical Analysis Used: The data were collected, charted, and analyzed using one-way ANOVA with post hoc LSD method for pairwise comparisons. Results: Least amount of surface roughness was achieved with Group C when compared with Group A and Group B. These differences were statistical significant (P < 0.0001). Conclusions: Air polishing can effectively smoothen the root surface by removing surface irregularities which are produced hand/ultrasonic instruments. Profilometer can be effectively used to measure the surface roughness.

Molecular Level Dissection of Critical Spike Mutations in SARS-CoV-2 Variants of Concern (VOCs): A Simplified Review.

SARS-CoV-2 virus during its spread in the last one and half year has picked up critical changes in its genetic code i.e. mutations, which have leads to deleterious epidemiological characteristics. Due to critical role of spike protein in cell entry and pathogenesis, mutations in spike regions have been reported to enhance transmissibility, disease severity, possible escape from vaccine-induced immune response and reduced diagnostic sensitivity/specificity. Considering the structure-function impact of mutations, understanding the molecular details of these key mutations of newly emerged variants/lineages is of urgent concern. In this review, we have explored the literature on key spike mutations harbored by alpha, beta, gamma and delta 'variants of concern' (VOCs) and discussed their molecular consequences in the context of resultant virus biology. Commonly all these VOCs i.e. B.1.1.7, B.1.351, P.1 and B.1.617.2 lineages have decisive mutation in Receptor Binding Motif (RBM) region and/or region around Furin cleavage site (FCS) of spike protein. In general, mutation induced disruption of intra-molecular interaction enhances molecular flexibility leading to exposure of spike protein surface in these lineages to make it accessible for inter-molecular interaction with hACE2. A disruption of spike antigen-antibody inter-molecular interactions in epitope region due to the chemical nature of substituting amino acid hampers the neutralization efficacy. Simplified surveillance of mutation induced changes and their consequences at molecular level can contribute in rationalizing mutation's impact on virus biology. It is believed that molecular level dissection of these key spike mutation will assist the future investigations for a more resilient outcome against severity of COVID-19.

Occupational exposures to bloodborne pathogens and its underreporting in dental teaching environment in an Indian dental school.

INTRODUCTION: The aims of this study were 1) to find out the prevalence of occupational exposures to contaminated biological material among undergraduate students and interns; 2) to find out how many cases of occupational exposures to bloodborne pathogens are reported; and 3) to know the reasons for non-reporting of occupational exposures. MATERIALS AND METHODS: The study was conducted in a Dental School in Navi-Mumbai, India. An anonymous self-administered questionnaire was formulated. 210 dental students were given a questionnaire out of which 150 students attending clinical postings in their third year, final year, and internship responded. Approval was obtained from the Institutional Ethical Committee. RESULTS: The study revealed a very high prevalence (66.7%) of exposures among the students. Only 12% of the students reported the exposures to the staff. Students from III year and final year BDS (Bachelor of Dental Surgery) had mean exposure of 2.40 as compared to 1.94 among interns. 46% of the students stated that they did not report about the exposure because they thought that injury was of minor nature. CONCLUSION: There is a very high prevalence of occupational exposures among students which are not reported. There is a need for the development of a post exposure protocol which has to be strictly implemented. The principle of infection control has to be emphasised to the students periodically and they should be encouraged to report incidences of exposures to biological material.

Evaluation of an Antimicrobial Stewardship Program for Wound and Burn Care in Three Hospitals in Nepal.

Antimicrobial stewardship (AMS) programs can decrease non-optimal use of antibiotics in hospital settings. There are limited data on AMS programs in burn and chronic wound centers in low- and middle-income countries (LMIC). A post-prescription review and feedback (PPRF) program was implemented in three hospitals in Nepal with a focus on wound and burn care. A total of 241 baseline and 236 post-intervention patient chart data were collected from three hospitals. There was a significant decrease in utilizing days of therapy per 1000 patient days (DOT/1000 PD) of penicillin (p = 0.02), aminoglycoside (p < 0.001), and cephalosporin (p = 0.04). Increases in DOT/1000 PD at post-intervention were significant for metronidazole (p < 0.001), quinolone (p = 0.01), and other antibiotics (p < 0.001). Changes in use of antibiotics varied across hospitals, e.g., cephalosporin use decreased significantly at Kirtipur Hospital (p < 0.001) and Pokhara Academy of Health Sciences (p = 0.02), but not at Kathmandu Model Hospital (p = 0.59). An independent review conducted by infectious disease specialists at the Henry Ford Health System revealed significant changes in antibiotic prescribing practices both overall and by hospital. There was a decrease in mean number of intravenous antibiotic days between baseline (10.1 (SD 8.8)) and post-intervention (8.8 (SD 6.5)) (t = 3.56; p < 0.001), but no difference for oral antibiotics. Compared to baseline, over the 6-month post-intervention period, we found an increase in justified use of antibiotics (p < 0.001), de-escalation (p < 0.001), accurate documentation (p < 0.001), and adherence to the study antibiotic prescribing guidelines at 72 h (p < 0.001) and after diagnoses (p < 0.001). The evaluation data presented provide evidence that PPRF training and program implementation can contribute to hospital-based antibiotic stewardship for wound and burn care in Nepal.

Evaluation of a Hospital-Based Post-Prescription Review and Feedback Pilot in Kathmandu, Nepal.

Capacity building is needed in low- and middle-income countries (LMICs) to combat antimicrobial resistance (AMR). Stewardship programs such as post-prescription review and feedback (PPRF) are important components in addressing AMR. Little data are available regarding effectiveness of PPRF programs in LMIC settings. An adapted PPRF program was implemented in the medicine, surgery, and obstetrics/gynecology wards in a 125-bed hospital in Kathmandu. Seven "physician champions" were trained. Baseline and post-intervention patient chart data were analyzed for changes in days of therapy (DOT) and mean number of course days for intravenous and oral antibiotics, and for specific study antibiotics. Charts were independently reviewed to determine justification for prescribed antibiotics. Physician champions documented recommendations. Days of therapy per 1,000 patient-days for courses of aminoglycoside (P < 0.001) and cephalosporin (P < 0.001) decreased. In the medicine ward, data indicate increased justified use of antibiotics (P = 0.02), de-escalation (P < 0.001), rational use of antibiotics (P < 0.01), and conforming to guidelines in the first 72 hours (P = 0.02), and for definitive therapy (P < 0.001). Physician champions documented 437 patient chart reviews and made 138 recommendations; 78.3% of recommendations were followed by the attending physician. Post-prescription review and feedback can be successfully implemented in LMIC hospitals, which often lack infectious disease specialists. Future program adaptation and training will focus on identifying additional stewardship programming and support mechanisms to optimize antibiotic use in LMICs.

Extra-articular distal tibial fractures, is interlocking nailing an option? A prospective study of 147 cases.

PURPOSE: Distal tibia fractures comprise about 7%-10% of lower extremity trauma. Because of the peculiarity of the soft tissue and subcutaneous location of the bone there are many controversies in the ideal treatment of distal tibia fractures especially extra articular pilon fractures. Plating is fraught with complications of wound dehiscence and infection. There are limited studies which document outcomes in such cases using intramedullary interlocking nail. We intend to study the outcome and complications of extra articular distal tibial fractures treated with interlocking nailing. METHODS: This is a prospective study conducted in a tertiary care orthopaedic hospital in southern India. There are 147 patients of distal tibia extra-articular fractures managed by IM nailing with follow up of more than one year were included in this study. Only cases with fresh injury (less than 1 week), fracture below the isthmus, closed and open Gustilo Anderson type 1 and 2 fractures were included in the study. Patients were reviewed at 3, 6, 12 and 24 weeks after surgery and thereafter at one year and were assessed for clinical and radiological signs of healing, any complications, time to union and functional outcome. RESULTS: There were 102 males and 45 females (male/female ratio is 2.3:1) with a mean age of 38.96 (range 23-65) years. According to AO classification, there were 78 cases (53.06%) of 43-A1, 39 cases (26.53%) of 43-A2 and 30 cases of 43-A3 constituting 20.40%. The fracture united in all the patients at an average of 18 weeks (range 16-22 weeks), none of the patient in our series had a delayed or non-union. Two patients (1.47%) had the fracture united in mild valgus but it was well within the acceptable limits (<5°). The functional outcome was assessed in all the patients at final follow up using Olerud and Molander score all the patients fared an excellent to good score, there were no cases with poor score. CONCLUSION: Intramedullary nailing is a viable option to treat distal tibial fractures with excellent outcome. Wound complications related to plating can be avoided but meticulous surgical technique is key to avoid malunion.

Separation and quantitation of eight isomers in a molecule with three stereogenic centers by normal phase liquid chromatography.

A normal phase liquid chromatography method was developed for the separation and detection of eight stereoisomers of the key intermediate, CORE + OMe, having three chiral centers. The stereochemistry of this intermediate dictates the stereochemistry of the active pharmaceutical ingredient generated by an additional six synthetic steps. Multiple columns and mobile phases were screened during the development based on a platform approach. The use of dichloromethane as mobile phase additive and adjustment of flow rate and column temperature contributed in achieving resolution of these eight stereoisomers. The separation and detection of these stereoisomers was achieved using a Chiralcel OD-H, 4.6 × 250 mm, 5 µm dp column with heptane: ethanol: dichloromethane in a ratio of 95:3:2 (v:v:v) as mobile phase at a flow rate of 0.7 mL/min. UV detection was carried out at 245 nm and the column temperature was maintained at 15 °C. The analytical method was phase appropriately validated. The limit of detection and limit of quantification were found to be 0.035 and 0.07 µg, respectively. The newly developed method has been implemented for routine utilization to monitor the chiral control during process development and used as the quality control method for chiral purity of the desired compound.

Typhoid vaccine introduction: An evidence-based pilot implementation project in Nepal and Pakistan.

The World Health Organization (WHO) in 2008 recommended the use of currently licensed typhoid vaccines using a high risk or targeted approach. The epidemiology of disease and the vaccine characteristics make school-based vaccination most feasible in reducing typhoid disease burden in many settings. To assess feasibility of school-based typhoid vaccination, two districts in Kathmandu, Nepal and two towns in Karachi, Pakistan were selected for pilot program. Vaccination campaigns were conducted through the departments of health and in partnerships with not-for-profit organizations. In total 257,015 doses of Vi polysaccharide vaccine were given to students in grades 1-10 of participating schools. The vaccination coverage ranged from 39 percent (38,389/99,503) in Gulshan town in Karachi, to 81 percent (62,615/77,341) in Bhaktapur in Kathmandu valley. No serious adverse event was reported post vaccination. The coverage increased for vaccination of the second district in Pakistan as well as in Nepal. There was an initial concern of vaccine safety. However, as the campaign progressed, parents were more comfortable with vaccinating their children in schools. Supported and conducted by departments of health in Pakistan and Nepal, a school-based typhoid vaccination was found to be safe and feasible.

Periodontal status following treatment of impacted maxillary canines by closed eruption technique: an overview and case report.

UNLABELLED: Delayed tooth eruption is a common problem in many orthodontic patients. This delay may lead to other problems, such as injury to the adjacent tooth, non-vitalization, mucogingival and esthetic problems, etc. Multidisciplinary management is essential when the canines of orthodontic patients have failed to erupt on time. This involves combined surgical and orthodontic intervention. This overview and case report presents special considerations required in treating such cases. METHODS: A combined surgical and orthodontic treatment approach is essential in dealing with such cases. The type of surgery depends on correct localization of the canine along with evaluation of certain criteria to determine the correct method for uncovering the tooth. RESULTS: Success of the treatment in such cases should be defined as long-term desirable esthetics and sound periodontal condition. Thorough treatment planning based on specific criteria would ensure this. CONCLUSION: A multidisciplinary approach, atraumatic surgery, and judicious use of orthodontic forces can ensure an excellent result in form, function, and esthetics in cases with delayed canine eruption.

25 years after Vi typhoid vaccine efficacy study, typhoid affects significant number of population in Nepal.

Salmonella Typhi, first isolated in 1884, results in infection of the intestines and can end in death and disability. Due to serious adverse events post vaccination, whole cell killed vaccines have been replaced with new generation vaccines. The efficacy of Vi polysaccharide (ViPS) vaccine, a new generation, single-dose intramuscular typhoid vaccine was assessed in Nepal in 1987. However, despite the availability of ViPS vaccine for more than 25 years, Nepal has one of the highest incidence of typhoid fever. Therefore we collected information from hospitals in the Kathmandu Valley from over the past five years. There were 9901 enteric fever cases between January 2008 and July 2012. 1,881 of these were confirmed typhoid cases from five hospitals in the Kathmandu district. Approximately 70% of the cases involved children under 15 years old. 1281 cases were confirmed as S. Paratyphi. Vaccines should be prioritized for control of typhoid in conjunction with improved water and sanitation conditions in Nepal and in endemic countries of Asia and Africa.

A tRNA-independent mechanism for transamidosome assembly promotes aminoacyl-tRNA transamidation.

Many bacteria lack genes encoding asparaginyl- and/or glutaminyl-tRNA synthetase and consequently rely on an indirect path for the synthesis of both Asn-tRNA(Asn) and Gln-tRNA(Gln). In some bacteria such as Thermus thermophilus, efficient delivery of misacylated tRNA to the downstream amidotransferase (AdT) is ensured by formation of a stable, tRNA-dependent macromolecular complex called the Asn-transamidosome. This complex enables direct delivery of Asp-tRNA(Asn) from the non-discriminating aspartyl-tRNA synthetase to AdT, where it is converted into Asn-tRNA(Asn). Previous characterization of the analogous Helicobacter pylori Asn-transamidosome revealed that it is dynamic and cannot be stably isolated, suggesting the possibility of an alternative mechanism to facilitate assembly of a stable complex. We have identified a novel protein partner called Hp0100 as a component of a stable, tRNA-independent H. pylori Asn-transamidosome; this complex contains a non-discriminating aspartyl-tRNA synthetase, AdT, and Hp0100 but does not require tRNA(Asn) for assembly. Hp0100 also enhances the capacity of AdT to convert Asp-tRNA(Asn) into Asn-tRNA(Asn) by ∼35-fold. Our results demonstrate that bacteria have adopted multiple divergent methods for transamidosome assembly and function.

The kinase activity of the Helicobacter pylori Asp-tRNA(Asn)/Glu-tRNA(Gln) amidotransferase is sensitive to distal mutations in its putative ammonia tunnel.

The Helicobacter pylori (Hp) Asp-tRNA(Asn)/Glu-tRNA(Gln) amidotransferase (AdT) plays important roles in indirect aminoacylation and translational fidelity. AdT has two active sites, in two separate subunits. Kinetic studies have suggested that interdomain communication occurs between these subunits; however, this mechanism is not well understood. To explore domain-domain communication in AdT, we adapted an assay and optimized it to kinetically characterize the kinase activity of Hp AdT. This assay was applied to the analysis of a series of point mutations at conserved positions throughout the putative AdT ammonia tunnel that connects the two active sites. Several mutations that caused significant decreases in AdT's kinase activity (reduced by 55-75%) were identified. Mutations at Thr149 (37 Å distal to the GatB kinase active site) and Lys89 (located at the interface of GatA and GatB) were detrimental to AdT's kinase activity, suggesting that these mutations have disrupted interdomain communication between the two active sites. Models of wild-type AdT, a valine mutation at Thr149, and an arginine mutation at Lys89 were subjected to molecular dynamics simulations. A comparison of wild-type, T149V, and K89R AdT simulation results unmasks 59 common residues that are likely involved in connecting the two active sites.

Papillon-Lefevre syndrome: A report of two cases.

Papillon-Lefevre syndrome is a rare (1-4 cases per million) autosomal recessive disorder showing predominantly oral and dermatological manifestations in the form of aggressive periodontitis affecting both primary and permanent dentition and palmoplantar hyperkeratosis. Genetic studies have shown that mutations in the major gene locus of chromosome 11q14 with loss of function of cathepsin C gene are responsible for Papillon-Lefevre syndrome. This report presents two siblings with classic signs and symptoms of Papillon-Lefevre syndrome. The exact cause for periodontal destruction in patients with Papillon-Lefevre syndrome is not known but it is thought to be due to defect in neutrophil function, immune suppression and mutations in cathepsin C gene.