Publications by authors named "Uma Nayak"

Background: Astroviral infections commonly cause acute nonbacterial gastroenteritis in children globally. However, these infections often go undiagnosed outside of research settings. There is no treatment available for astrovirus, and Astroviridae strain diversity presents a challenge to potential vaccine development.

View Article and Find Full Text PDF

Objectives: Clostridioides difficile infection (CDI) is characterized by neutrophilia in blood, with a high leukocyte count accompanying severe infection. In this study, we characterized peripheral blood neutrophil activation and maturity in CDI by (i) developing a method to phenotype stored neutrophils for disease-related developmental alterations and (ii) assessing neutrophil-associated biomarkers.

Methods: We stored fixed leukocytes from blood collected within 24 h of diagnosis from a cohort of hospitalized patients with acute CDI.

View Article and Find Full Text PDF
Article Synopsis
  • Type 2 diabetes (T2D) is a complex disease influenced by various genetic factors and molecular mechanisms that vary by cell type and ancestry.
  • In a large study involving over 2.5 million individuals, researchers identified 1,289 significant genetic associations linked to T2D, including 145 new loci not previously reported.
  • The study categorized T2D signals into eight distinct clusters based on their connections to cardiometabolic traits and showed that these genetic profiles are linked to vascular complications, emphasizing the role of obesity-related processes across different ancestry groups.
View Article and Find Full Text PDF

Background: We previously conducted a phase 2a randomized placebo-controlled trial of 40 subjects to assess the efficacy and safety of dupilumab use in people hospitalized with coronavirus disease 2019 (COVID-19) (NCT04920916). Based on our preclinical data suggesting that downstream pulmonary dysfunction with COVID-19 induced type 2 inflammation, we contacted patients from our phase 2a study at 1 year for assessment of post-COVID-19 conditions.

Methods: Subjects at 1 year after treatment underwent pulmonary function tests, high-resolution computed tomographic imaging, symptom questionnaires, neurocognitive assessments, and serum immune biomarker analysis, with subject survival also monitored.

View Article and Find Full Text PDF

The WHO pre-qualified rotavirus vaccine, ROTAVAC®, is derived naturally from the neonatal 116E rotavirus strain, and stored at -20°C. As refrigerator storage is preferable, immunogenicity and safety of liquid formulations kept at 2-8°C, having excipients to stabilize the rotavirus, with or without buffers, were compared with ROTAVAC® in different clinical studies. Study-1, the pivotal trial for this entire product development work, was a randomized, single-blind trial with two operationally seamless phases: (i) an exploratory phase involving 675 infants in which two formulations, ROTAVAC 5C (LnHRV-1.

View Article and Find Full Text PDF

Background: We previously conducted a Phase IIa randomized placebo-controlled trial of 40 subjects to assess the efficacy and safety of dupilumab use in those hospitalized with COVID-19 (NCT04920916). Based on our pre-clinical data suggesting downstream pulmonary dysfunction with COVID-19 induced type 2 inflammation, we contacted patients from our Phase IIa study at 1 year for assessment of Post Covid-19 Conditions (PCC).

Methods: Subjects at 1 year after treatment underwent pulmonary function testing (PFTs), high resolution computed tomography (HRCT) imaging, symptom questionnaires, neurocognitive assessments, and serum immune biomarker analysis, with subject survival also monitored.

View Article and Find Full Text PDF

To address the challenge of translating genetic discoveries for type 1 diabetes (T1D) into mechanistic insight, we have developed the T1D Knowledge Portal (T1DKP), an open-access resource for hypothesis development and target discovery in T1D.

View Article and Find Full Text PDF

Background: is one of the top causes of diarrhea in Bangladesh infants. infections lead to the production of antibody immune responses, which were associated with a decrease in parasite burden and decreased disease severity in subsequent infections.

Methods: We conducted a longitudinal study of cryptosporidiosis from birth to five years of age in an urban slum of Dhaka Bangladesh.

View Article and Find Full Text PDF

Type 2 diabetes (T2D) is a heterogeneous disease that develops through diverse pathophysiological processes. To characterise the genetic contribution to these processes across ancestry groups, we aggregate genome-wide association study (GWAS) data from 2,535,601 individuals (39.7% non-European ancestry), including 428,452 T2D cases.

View Article and Find Full Text PDF

Background: Diarrhea is the second leading cause of death in children under 5 years old worldwide. Known diarrhea risk factors include sanitation, water sources, and pathogens but do not fully explain the heterogeneity in frequency and duration of diarrhea in young children. We evaluated the role of host genetics in diarrhea.

View Article and Find Full Text PDF

Translating genetic discoveries for type 1 diabetes (T1D) into mechanistic insight can reveal novel biology and therapeutic targets but remains a major challenge. We developed the T1D Knowledge Portal (T1DKP), a disease-specific resource of genetic and functional annotation data that enables users to develop hypotheses for T1D-based research and target discovery. The T1DKP can be used to query genes and genomic regions for genetic associations, identify epigenomic features, access results of bioinformatic analyses, and obtain expert-curated resources.

View Article and Find Full Text PDF

Background: Based on studies implicating the type 2 cytokine interleukin 13 (IL-13) as a potential contributor to critical coronavirus disease 2019 (COVID-19), this trial was designed as an early phase 2 study to assess dupilumab, a monoclonal antibody that blocks IL-13 and interleukin 4 signaling, for treatment of inpatients with COVID-19.

Methods: We conducted a phase 2a randomized, double-blind, placebo-controlled trial (NCT04920916) to assess the safety and efficacy of dupilumab plus standard of care vs placebo plus standard of care in mitigating respiratory failure and death in those hospitalized with COVID-19.

Results: Forty eligible subjects were enrolled from June to November of 2021.

View Article and Find Full Text PDF

We assembled an ancestrally diverse collection of genome-wide association studies (GWAS) of type 2 diabetes (T2D) in 180,834 affected individuals and 1,159,055 controls (48.9% non-European descent) through the Diabetes Meta-Analysis of Trans-Ethnic association studies (DIAMANTE) Consortium. Multi-ancestry GWAS meta-analysis identified 237 loci attaining stringent genome-wide significance (P < 5 × 10), which were delineated to 338 distinct association signals.

View Article and Find Full Text PDF
Article Synopsis
  • Diarrhea causes over 500,000 child deaths annually, particularly in low-to-middle-income countries (LMICs), and is associated with malnutrition and stunted growth in children.
  • A study in Bangladesh examined how host genetics might impact susceptibility to Campylobacter infections, involving 534 children monitored for diarrhea over two years.
  • The research identified a significant genetic variant on chromosome 8 that suggests individuals with the G allele are at a lower risk for Campylobacter-related diarrhea, potentially due to its influence on the expression of nearby genes related to bacterial toxin transport.
View Article and Find Full Text PDF

Background: A profound need remains to develop further therapeutics for treatment of those hospitalized with COVID-19. Based on data implicating the type 2 cytokine interleukin (IL)-13 as a significant factor leading to critical COVID-19, this trial was designed to assess dupilumab, a monoclonal antibody that blocks IL-13 and IL-4 signaling, for treatment of inpatients with COVID-19.

Methods: We conducted a phase IIa randomized double-blind placebo-controlled trial to assess the safety and efficacy of dupilumab plus standard of care versus placebo plus standard of care in mitigating respiratory failure and death in those hospitalized with COVID-19.

View Article and Find Full Text PDF

Group A rotaviruses (RVA) remain a leading cause of pediatric diarrhea worldwide, in part due to underperformance of currently approved live-attenuated, oral vaccines in low-and-middle income countries. Improved immune correlates of protection (CoP) for existing oral vaccines and novel strategies to evaluate the performance of next-generation vaccines are needed. Use of oral vaccines as challenge agents in controlled human infection models is a potential approach to CoP discovery that remains underexplored.

View Article and Find Full Text PDF

Introduction: Small intestine bacterial overgrowth (SIBO) is common in children from low-income countries and has been cross-sectionally associated with growth stunting. We sought to determine whether SIBO was associated with poor growth and neurodevelopmental in a longitudinal analysis.

Methods: We measured SIBO by glucose hydrogen breath test (GHBT) at 18, 52, 78, and 104 weeks of life in a prospective longitudinal birth cohort of Bangladeshi children.

View Article and Find Full Text PDF

We conducted a longitudinal study of cryptosporidiosis from birth to three years of age in an urban slum of Dhaka Bangladesh. Fecal DNA was extracted from monthly surveillance samples and diarrheal stool samples collected from 392 infants from birth to three years. A pan-Cryptosporidium qPCR assay was used to identify sub-clinical and symptomatic cryptosporidiosis.

View Article and Find Full Text PDF

Objectives: Gullah African Americans are descendants of formerly enslaved Africans living in the Sea Islands along the coast of the southeastern U.S., from North Carolina to Florida.

View Article and Find Full Text PDF

Although many loci have been associated with height in European ancestry populations, very few have been identified in African ancestry individuals. Furthermore, many of the known loci have yet to be generalized to and fine-mapped within a large-scale African ancestry sample. We performed sex-combined and sex-stratified meta-analyses in up to 52,764 individuals with height and genome-wide genotyping data from the African Ancestry Anthropometry Genetics Consortium (AAAGC).

View Article and Find Full Text PDF

Background: The protozoan parasites in the Cryptosporidium genus cause both acute diarrheal disease and subclinical (ie, nondiarrheal) disease. It is unclear if the microbiota can influence the manifestation of diarrhea during a Cryptosporidium infection.

Methods: To characterize the role of the gut microbiota in diarrheal cryptosporidiosis, the microbiome composition of both diarrheal and surveillance Cryptosporidium-positive fecal samples from 72 infants was evaluated using 16S ribosomal RNA gene sequencing.

View Article and Find Full Text PDF

is a leading cause of moderate-to-severe diarrhea globally and the causative agent of shigellosis and bacillary dysentery. Associated with 80 to 165 million cases of diarrhea and >13% of diarrheal deaths, in many regions, exposure is ubiquitous while infection is heterogenous. To characterize host-genetic susceptibility to -associated diarrhea, we performed two independent genome-wide association studies (GWAS) including Bangladeshi infants from the PROVIDE and CBC birth cohorts in Dhaka, Bangladesh.

View Article and Find Full Text PDF

Background: Diarrheal pathogens have been associated with linear growth deficits. The effect of diarrheal pathogens on growth is likely due to inflammation, which also adversely affects neurodevelopment. We hypothesized that diarrheagenic pathogens would be negatively associated with both growth and neurodevelopment.

View Article and Find Full Text PDF

In a cohort of infants, we found that lack of the Lewis histo-blood group antigen was associated with increased susceptibility to shigellosis. Broadly inhibiting fucosylation in epithelial cells in vitro decreased invasion by Shigella flexneri. These results support a role for fucosylated glycans in susceptibility to shigellosis.

View Article and Find Full Text PDF