Malnutrition and maternal vaccination against typhoid toxin.

Children are particularly susceptible to typhoid fever caused by the bacterial pathogen Salmonella Typhi. Typhoid fever is prevalent in developing countries where diets can be less well-balanced. Here, using a murine model, we investigated the role of the macronutrient composition of the diet in maternal vaccination efficacies of two subunit vaccines targeting typhoid toxin: ToxoidVac and PltBVac. We found that maternal vaccinations protected all offspring against a lethal-dose typhoid toxin challenge in a balanced, normal diet (ND) condition, but the declined protection in a malnourished diet (MD) condition was observed in the PltBVac group. Despite the comparable antibody titers in both MD and ND mothers, MD offspring had a significantly lower level of typhoid toxin neutralizing antibodies than their ND counterparts. We observed a lower expression of the neonatal Fc receptor on the yolk sac of MD mothers than in ND mothers, agreeing with the observed lower antibody titers in MD offspring. Protein supplementation to MD diets, but not fat supplementation, increased FcRn expression and protected all MD offspring from the toxin challenge. Similarly, providing additional typhoid toxin-neutralizing antibodies to MD offspring was sufficient to protect all MD offspring from the toxin challenge. These results emphasize the significance of balanced/normal diets for a more effective maternal vaccination transfer to their offspring.

Understanding the Molecular Progression of Chronic Traumatic Encephalopathy in Traumatic Brain Injury, Aging and Neurodegenerative Disease.

Traumatic brain injury (TBI) is one of the leading causes of death and disability among children and adults in America. In addition, the acute morbidity caused by TBI is implicated in the development of devastating neuropsychiatric and neurodegenerative sequela. TBI is associated with the development of a neurodegenerative condition termed 'Punch Drunk syndrome' or 'dementia pugilistica', and the more recently renamed 'chronic traumatic encephalopathy'. Chronic traumatic encephalopathy (CTE) is a slowly progressive neurodegenerative condition caused by a single or repetitive blow to the head. CTE was first described in boxers and was later found to be associated with other contact sports and military combat. It is defined by a constellation of symptoms consisting of mood disorders, cognitive impairment, and memory loss with or without sensorimotor changes. It is also a Tauopathy characterized by the deposition of hyperphosphorylated Tau protein in the form of neurofibrillary tangles, astrocytoma tangles, and abnormal neurites found in clusters around small vessels, typically at the sulcal depths. Oxidative stress, neuroinflammation, and glutaminergic toxicity caused due to the insult play a role in developing this pathology. Additionally, the changes in the brain due to aging also plays an important role in the development of this condition. In this review, we discuss the molecular mechanisms behind the development of CTE, as well as genetic and environmental influences on its pathophysiology.

Neutralization of Typhoid Toxin by Alpaca-Derived, Single-Domain Antibodies Targeting the PltB and CdtB Subunits.

Typhoid toxin is secreted by the typhoid fever-causing bacterial pathogen Salmonella enterica serovar Typhi and has tropism for immune cells and brain endothelial cells. Here, we generated a camelid single-domain antibody (VHH) library from typhoid toxoid-immunized alpacas and identified 41 VHHs selected on the glycan receptor-binding PltB and nuclease CdtB. VHHs exhibiting potent in vitro neutralizing activities from each sequence-based family were epitope binned via competition enzyme-linked immunosorbent assays (ELISAs), leading to 6 distinct VHHs, 2 anti-PltBs (T2E7 and T2G9), and 4 anti-CdtB VHHs (T4C4, T4C12, T4E5, and T4E8), whose in vivo neutralizing activities and associated toxin-neutralizing mechanisms were investigated. We found that T2E7, T2G9, and T4E5 effectively neutralized typhoid toxin in vivo, as demonstrated by 100% survival of mice administered a lethal dose of typhoid toxin and with little to no typhoid toxin-mediated upper motor function defect. Cumulatively, these results highlight the potential of the compact antibodies to neutralize typhoid toxin by targeting the glycan-binding and/or nuclease subunits.

Differential and overlapping targets of the transcriptional regulators NRF1, NRF2, and NRF3 in human cells.

The nuclear factor (erythroid 2)-like (NRF) transcription factors are a subset of cap'n'collar transcriptional regulators. They consist of three members, NRF1, NRF2, and NRF3, that regulate the expression of genes containing antioxidant-response elements (AREs) in their promoter regions. Although all NRF members regulate ARE-containing genes, each is associated with distinct roles. A comprehensive study of differential and overlapping DNA-binding and transcriptional activities of the NRFs has not yet been conducted. Here, we performed chromatin immunoprecipitation (ChIP)-exo sequencing, an approach that combines ChIP with exonuclease treatment to pinpoint regulatory elements in DNA with high precision, in conjunction with RNA-sequencing to define the transcriptional targets of each NRF member. Our approach, done in three U2OS cell lines, identified 31 genes that were regulated by all three NRF members, 27 that were regulated similarly by all three, and four genes that were differentially regulated by at least one NRF member. We also found genes that were up- or down-regulated by only one NRF member, with 84, 84, and 22 genes that were regulated by NRF1, NRF2, and NRF3, respectively. Analysis of the ARE motifs identified in ChIP peaks revealed that NRF2 prefers binding to AREs flanked by GC-rich regions and that NRF1 prefers AT-rich flanking regions. Thus, sequence preference, likely in combination with upstream signaling events, determines NRF member activation under specific cellular contexts. Our analysis provides a comprehensive description of differential and overlapping gene regulation by the transcriptional regulators NRF1, NRF2, and NRF3.

Two ABC Transporters and a Periplasmic Metallochaperone Participate in Zinc Acquisition in Paracoccus denitrificans.

Bacteria must acquire the essential element zinc from extremely limited environments, and this function is performed largely by ATP binding cassette (ABC) transporters. These systems rely on a periplasmic or extracellular solute binding protein (SBP) to bind zinc specifically with a high affinity and deliver it to the membrane permease for import into the cytoplasm. However, zinc acquisition systems in bacteria may be more complex, involving multiple transporters and other periplasmic or extracellular zinc binding proteins. Here we describe the zinc acquisition functions of two zinc SBPs (ZnuA and AztC) and a novel periplasmic metallochaperone (AztD) in Paracoccus denitrificans. ZnuA was characterized in vitro and demonstrated to bind as many as 5 zinc ions with a high affinity. It does not interact with AztD, in contrast to what has been demonstrated for AztC, which is able to acquire a single zinc ion through associative transfer from AztD. Deletions of the corresponding genes singly and in combination show that either AztC or ZnuA is sufficient and essential for robust growth in zinc-limited media. Although AztD cannot support transport of zinc into the cytoplasm, it likely functions to store zinc in the periplasm for transfer through the AztABCD system.

Mechanisms of zinc binding to the solute-binding protein AztC and transfer from the metallochaperone AztD.

Bacteria can acquire the essential metal zinc from extremely zinc-limited environments by using ATP-binding cassette (ABC) transporters. These transporters are critical virulence factors, relying on specific and high-affinity binding of zinc by a periplasmic solute-binding protein (SBP). As such, the mechanisms of zinc binding and release among bacterial SBPs are of considerable interest as antibacterial drug targets. Zinc SBPs are characterized by a flexible loop near the high-affinity zinc-binding site. The function of this structure is not always clear, and its flexibility has thus far prevented structural characterization by X-ray crystallography. Here, we present intact structures for the zinc-specific SBP AztC from the bacterium Paracoccus denitrificans in the zinc-bound and apo-states. A comparison of these structures revealed that zinc loss prompts significant structural rearrangements, mediated by the formation of a sodium-binding site in the apo-structure. We further show that the AztC flexible loop has no impact on zinc-binding affinity, stoichiometry, or protein structure, yet is essential for zinc transfer from the metallochaperone AztD. We also found that 3 His residues in the loop appear to temporarily coordinate zinc and then convey it to the high-affinity binding site. Thus, mutation of any of these residues to Ala abrogated zinc transfer from AztD. Our structural and mechanistic findings conclusively identify a role for the AztC flexible loop in zinc acquisition from the metallochaperone AztD, yielding critical insights into metal binding by AztC from both solution and AztD. These proteins are highly conserved in human pathogens, making this work potentially useful for the development of novel antibiotics.

Transcriptional Regulation, Metal Binding Properties and Structure of Pden1597, an Unusual Zinc Transport Protein from Paracoccus denitrificans.

ATP-binding cassette (ABC) transporters of the cluster 9 family are ubiquitous among bacteria and essential for acquiring Zn(2+) and Mn(2+) from the environment or, in the case of pathogens, from the host. These rely on a substrate-binding protein (SBP) to coordinate the relevant metal with high affinity and specificity and subsequently release it to a membrane permease for translocation into the cytoplasm. Although a number of cluster 9 SBP structures have been determined, the structural attributes conferring Zn(2+) or Mn(2+) specificity remain ambiguous. Here we describe the gene expression profile, in vitro metal binding properties, and crystal structure of a new cluster 9 SBP from Paracoccus denitrificans we have called AztC. Although all of our results strongly indicate Zn(2+) over Mn(2+) specificity, the Zn(2+) ion is coordinated by a conserved Asp residue only observed to date as a metal ligand in Mn(2+)-specific SBPs. The unusual sequence properties of this protein are shared among close homologues, including members from the human pathogens Klebsiella pneumonia and Enterobacter aerogenes, and would seem to suggest a subclass of Zn(2+)-specific transporters among the cluster 9 family. In any case, the unusual coordination environment of AztC expands the already considerable range of those available to Zn(2+)-specific SBPs and highlights the presence of a His-rich loop as the most reliable indicator of Zn(2+) specificity.

AztD, a Periplasmic Zinc Metallochaperone to an ATP-binding Cassette (ABC) Transporter System in Paracoccus denitrificans.

Bacterial ATP-binding cassette (ABC) transporters of transition metals are essential for acquisition of necessary elements from the environment. A large number of Gram-negative bacteria, including human pathogens, have a fourth conserved gene of unknown function adjacent to the canonical permease, ATPase, and solute-binding protein (SBP) genes of the AztABC zinc transporter system. To assess the function of this putative accessory factor (AztD) from Paracoccus denitrificans, we have analyzed its transcriptional regulation, metal binding properties, and interaction with the SBP (AztC). Transcription of the aztD gene is significantly up-regulated under conditions of zinc starvation. Recombinantly expressed AztD purifies with slightly substoichiometric zinc from the periplasm of Escherichia coli and is capable of binding up to three zinc ions with high affinity. Size exclusion chromatography and a simple intrinsic fluorescence assay were used to determine that AztD as isolated is able to transfer bound zinc nearly quantitatively to apo-AztC. Transfer occurs through a direct, associative mechanism that prevents loss of metal to the solvent. These results indicate that AztD is a zinc chaperone to AztC and likely functions to maintain zinc homeostasis through interaction with the AztABC system. This work extends our understanding of periplasmic zinc trafficking and the function of chaperones in this process.

Nicotine exposure, blood pressure, and inflammation in tobacco smokers and chewers in a rural community in Nepal.

Tobacco consumption is high amongst the people of Xxx. This study was carried out in 2011 in a rural community of Xxx, to compare pathological parameters associated with tobacco use in relation to nicotine metabolism between smokers, chewers, and a control group. A total of 216 volunteers provided blood and urine samples for testing nicotine metabolites, C-reactive protein, and cell counts. Data were analyzed using ANOVA, correlation, and t-tests using STATA. Differences in blood pressure amongst the groups indicate a role of smoking in preventing a rise in BP with age, likely attributable to a different mechanism of metabolism of tobacco constituents.

Peutz-Jeghers syndrome: A case series.

INTRODUCTION: Peutz-Jeghers syndrome (PJS) is a rare hereditary disorder characterized by gastrointestinal hamartomatous polyps, due to mutation of the STK11/LKB1 gene located on chromosome 19p. The polyps are most commonly found in the small bowel followed by colon. CASE PRESENTATION: Our case series includes 4 patients, three being male and one female. Each of them either presented with abdominal pain and other associated symptoms. Oral cavity and lip melanin pigmentation were common. CT abdomen revealed multiple large jejunal, ileal, gastric and colon polyps. Cancer was found in one patient. Different surgical approaches were adopted. All recovered well. DISCUSSION: PJS is an autosomal dominant disorder with an estimated incidence of 1:50,000 to 1:200,000 cases with a significant family history. Mostly found in small bowel followed by colon, it can also occur in a rare organ like gall bladder as evident in our case. PJS carries a substantial risk for gastrointestinal cancer. The treatment modality depends on the site of polyp, mode of presentation and availability of the expertise. CONCLUSION: PJS is a common disease in our part which is usually observed in teen age groups male. They have a varied presentation, from intestinal obstruction (due to intussusception) to GI bleeding. Colonic malignancy at young age may be the first presentation of the disease. Observation of melanin pigmentations on lips helps diagnose the disease; and one should always look at this findings in a young patient with pain abdomen or in intestinal obstruction to confirm/exclude the disease.

Outcomes of stereotactic thalamotomy in patients of essential tremor: A systematic review.

BACKGROUND: Essential tremor is a neurological condition associated with movement disorder with more prevalence among adult group of population. The burden of essential tremor is peaking globally but with the advancement in the area of functional neurosurgery such as stereotactic thalamotomy, the quality of life of such patients can be improved drastically. METHODS: This systemic review was conducted in accordance to the guidance of preferred Reporting items for Systematic Review and Meta-Analysis(PRISMA). Databases of "PubMed", "Embase", "Web of Science", "Cinhal Plus", and "Scopus" from inception till 2023 was undertaken. A combination of keywords, Medical Subject Headings (MeSH), and search terms such as Search strategy for PubMed search was as follows: "stereotactic thalamotomy" AND "essential tremor". RESULTS: This systematic review analyzed 9 studies with a total of 274 patients of essential tremor patients. Unilateral thalamotomy was carried out among 268 patients and bilateral thalamotomy in rest of the patients. Vim and Vom nucleus were the site of thalamotmy with ventral intermedius nucleus being the major one. Ten different types of clinical tremor rating scales were used to assess pre operative and post operative improvement in the tremor scales of the individual patients. Dysarthria and limb weakness was noted post operative complication in majority of the cases. CONCLUSION: Our study revealed that stereotactic thalamotomy provided good functional outcome in patients of essential tremor who underwent unilateral thalamotomy compared to bilateral thalamotomy. The positive outcome outweighs the complications in such functional surgery.

Subclavian steal syndrome.

Early recognition and diagnosis of subclavian steal syndrome are vital to avoid unnecessary investigations and ensure appropriate management. This case highlights the significance of comprehensive evaluation, including bilateral blood pressure measurement, in patients with unilateral symptoms.

Continuous versus interrupted anastomotic technique for the hepaticojejunostomy: a prospective cohort study.

Background: Interrupted sutures is the gold standard technique of hepaticojejunostomy (HJ) for bilioenteric anastomosis. This study compares the safety and early complications of continuous and interrupted suture HJ. Methods: A prospective study involving all elective HJ between September 2019 and June 2021 was conducted. Patients with type IV or V biliary strictures, duct diameter less than 8 mm and/or associated vascular injury, and bilateral HJ were excluded. The study patients were divided into two random groups; interrupted and continuous anastomotic technique. Patient demographics, preoperative parameters including pathology (benign vs. malignant), HJ leak, suture time, and postoperative morbidity were recorded. Results: Total 34 patients were enroled. Eighteen (52.9%) were into interrupted and 16 (47.1%) patients into the continuous group. Both the groups were comparable with regards to demographics, haemoglobin, serum albumin, preoperative cholangitis and biliary stenting. Total three (8.8%) patients in the entire study developed bile leak; interrupted-2 and continuous-1, which was not significant statistically (P=1.0). Similarly, total number of sutures used and the mean operating time to complete anastomosis in the continuous group was significantly lesser than the interrupted group (2.3±0.5 versus 9.6±1.6, P<0.001) and (16.2±3.1 versus 38.6±9.2 min, P<0.001), respectively. There were three (18.8%) re-exploration in the continuous anastomotic technique. Among them, only one re-operation was due to HJ anastomosis failure without mortality, remaining had re-exploration for bleeding (non-HJ). Conclusions: Both the techniques is safe with comparable morbidity. Further, continuous has an added advantage of decreased anastomotic time and cost.

Tophaceous gout.

Hyperuricemic patients (≥7.8 mg/dL) can develop polyarticular tophaceous gout from intermittent arthritis if untreated. Acute flares and tophi development can be avoided by lowering blood urate levels with xanthine oxidase inhibitors.

Malignant rectal GIST managed with chemotherapy (Imatinib Mesylate): A case report and a comprehensive review.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal tumors involving the gastrointestinal tract, arising from the interstitial cells of Cajal. GIST comprises about 1% of all GI tumors. Rectal GISTs are rare and comprise of approximately 5% of all GISTs and only 0.1% of rectal tumors are found to be GISTs. Rectal GISTs may be diagnosed incidentally or present with symptoms, including defecation problems, bleeding, and/or pain. We report a case of a 46-year-old male with rectal GIST metastasized to the liver and bilateral lung parenchyma managed by Imatinib Mesylate (IM) regimen. Rectal GIST although being rare, must be considered as a differential diagnosis in a patient presenting with defecatory problems with bleeding.

Antibiotics use among residents in Eastern Nepal: a community-based mixed method study.

Introduction: According to the WHO, more than two-thirds of all antibiotics are used in the community, of which about 30% are used inappropriately. The antimicrobial resistance (AMR) problem is a growing threat to Nepal because of indiscriminate and inappropriate use. However, exact data on the extent of inappropriate use of antibiotics in the community is scarce in Nepal. Objectives: To know the extent of inappropriate use of antibiotics among the community and their knowledge and practice towards the usage of antibiotics. Methods: A community-based cross-sectional study was conducted from 20 December 2017 to 20 March 2018 using a purposive sampling technique. A semi-structured questionnaire was used while conducting face-to-face interviews with 336 respondents to find out the knowledge and practice regarding antibiotic use. Investigators took different antibiotics (in all dosage forms) with them to show participants whether they knew and/or used the antibiotics in the last year. Results: The mean age of respondents with standard deviation was 39.87±13.67 years ranging from 18 to 84 years. Around 35.42% of respondents were farmers and 34.52% were homemakers. 28.87% of respondents were illiterate, 32.44% had primary education and 33.33% had secondary education. Almost half of them (48.51%) think that antibiotics are safe and can be commonly used. So, 43.15% of them preferred taking antibiotics when they had a common cold. The majority of the participants (81.84%) did not have any idea about antibiotic resistance. 94.6% of the respondents used antibiotics inappropriately. Conclusion: The results of the present study revealed that inappropriate use of antibiotics is high and associated with low earning wages in both males and females in the age group 18-39 years.

Left segmental hypoplasia of liver with concomitant gallbladder agenesis.

Key Clinical Message Congenital liver anomalies are rarely reported. To the best of our knowledge and literature review, associated gallbladder agenesis with left hepatic lobe agenesis is extremely rare. The rarity of this condition and its uncertain radiological features often leads to misdiagnosis and unwarranted surgical treatments.

Recurrent pyogenic cholangitis.

The incidence of hepatolithiasis is variable. Globalization has additionally altered disease dynamics globally. A multi-disciplinary team approach is deemed necessary for the timely diagnosis, safe, affordable treatment, and good prognosis.

Spontaneous idiopathic omental bleeding: a case report of rare cause of acute abdomen.

Idiopathic omental hemorrhage is a rare cause of an acute abdomen, which is potentially life threatening. Here, we report a case of a 34-year-old male who presented to the emergency department with sudden, severe pain abdomen and abdominal distension for 1 day. There was no history of trauma, abdominal surgeries or any significant past medical history. The diagnosis was suspected on contrast computed tomography, which revealed hyperdense areas of blood in the peritoneal cavity with contrast extravasation from the omentum. The patient underwent successful emergency laparotomy, peritoneal lavage and greater omentectomy to achieve hemostasis.