226 research outputs found
A Protocol for NMR Analysis of the Enantiomeric Excess of Chiral Diols Using an Achiral Diboronic Acid Template
A practically simple derivatization
protocol for determining the
enantiopurity of chiral diols by <sup>1</sup>H NMR spectroscopic analysis
is described. Diols were treated with 0.5 equiv of 1,3-phenyldiboronic
acid to afford mixtures of diastereomeric boronate esters whose homochiral/heterochiral
ratios are an accurate reflection of the diol’s enantiopurity
Plasma proteomic signatures of enteric permeability among hospitalized and community children in Kenya and Pakistan
We aimed to establish if enteric permeability was associated with similar biological processes in children recovering from hospitalization and relatively healthy children in the community. Extreme gradient boosted models predicting the lactulose-rhamnose ratio (LRR), a biomarker of enteric permeability, using 7,500 plasma proteins and 34 fecal biomarkers of enteric infection among 89 hospitalized and 60 community children aged 2–23 months were built. The R2 values were calculated in test sets. The models performed better among community children (R2: 0.27 [min-max: 0.19, 0.53]) than hospitalized children (R2: 0.07 [min-max: 0.03, 0.11]). In the community, LRR was associated with biomarkers of humoral antimicrobial and cellular lipopolysaccharide responses and inversely associated with anti-inflammatory and innate immunological responses. Among hospitalized children, the selected biomarkers had few shared functions. This suggests enteric permeability among community children was associated with a host response to pathogens, but this association was not observed among hospitalized children
Plasma proteomic signatures associated with enteric permeability among hospitalized and community children under two years of age in Kenya and Pakistan
We aimed to establish if enteric permeability was associated with similar biological processes in children recovering from hospitalization and relatively healthy
children in the community. Extreme gradient boosted models predicting the lactulose-rhamnose ratio (LRR), a biomarker of enteric permeability, using 7,500
plasma proteins and 34 fecal biomarkers of enteric infection among 89 hospitalized and 60 community children aged 2–23 months were built. The R2 values were
calculated in test sets. The models performed better among community children
(R2
: 0.27 [min-max: 0.19, 0.53]) than hospitalized children (R2
: 0.07 [min-max:
0.03, 0.11]). In the community, LRR was associated with biomarkers of humoral
antimicrobial and cellular lipopolysaccharide responses and inversely associated
with anti-inflammatory and innate immunological responses. Among hospitalized
children, the selected biomarkers had few shared functions. This suggests enteric
permeability among community children was associated with a host response to
pathogens, but this association was not observed among hospitalized children
Enteric permeability, systemic inflammation, and post-discharge growth among a cohort of hospitalized children in Kenya and Pakistan
Objectives: To determine whether gut permeability is associated with post-discharge growth and systemic inflammation among hospitalized children in low- and middle-income countries.
Methods: Children aged 2–23 months being discharged from Civil Hospital Karachi (Pakistan) and Migori County Referral Hospital (Kenya) underwent lactulose-rhamnose ratio (LRR) permeability testing and were compared to age-matched children from their home communities. Linear mixed effect models estimated the associations between LRR among discharged children with change in length-for-age (LAZ) and weight-for-age z score (WAZ) at 45, 90, and 180 days after discharge. Linear regression tested if relationships between LRR, systemic inflammation [C-reative protein (CRP), Cluster of Differentiation 14 (CD14), Tumour Necrosis Factor Alpha (TNFα), Interleukin-6 (IL-6)], and enterocyte damage [Intestinal Fatty-Acid Binding protein (I-FABP)] differed between the hospitalized and community groups.
Results: One hundred thirty-seven hospitalized and 84 community participants were included. The hospitalized group had higher log-LRR [0.43, 95% confidence interval (CI): 0.15–0.71, P = 0.003] than the community children. Adjustment for weight-for-length z score at discharge attenuated this association (0.31, 95% CI: 0.00–0.62, P = 0.049). LRR was not associated with changes in WAZ or LAZ in the post-discharge period. Associations between LRR and CRP (interaction P = 0.036), TNFα (P = 0.017), CD14 (P = 0.078), and IL-6 (P = 0.243) differed between community and hospitalized groups. LRR was associated with TNFα (P = 0.004) and approached significance with CD14 (P = 0.078) and IL-6 (P = 0.062) in community children, but there was no evidence of these associations among hospitalized children.
Conclusions: Although increased enteric permeability is more prevalent among children being discharged from hospital compared to children in the community, it does not appear to be an important determinant of systemic inflammation or post-discharge growth among hospitalized children
Minimally invasive postmortem intestinal tissue sampling in malnourished and acutely ill children is feasible and informative
BACKGROUND: Intestinal disorders such as environmental enteric dysfunction (EED) are prevalent in low- and middle-income countries (LMICs) and important contributors to childhood undernutrition and mortality. Autopsies are rarely performed in LMICs but minimally invasive tissue sampling is increasingly deployed as a more feasible and acceptable procedure, although protocols have been devoid of intestinal sampling to date. We sought to determine (1) the feasibility of postmortem intestinal sampling, (2) whether autolysis precludes enteric biopsies\u27 utility, and (3) histopathologic features among children who died during hospitalization with acute illness or undernutrition.
METHODS: Transabdominal needle and endoscopic forceps upper and lower intestinal sampling were conducted among children aged 1 week to 59 months who died while hospitalized in Blantyre, Malawi. Autolysis ratings were determined for each hematoxylin and eosin slide, and upper and lower intestinal scoring systems were adapted to assess histopathologic features and their severity.
RESULTS: Endoscopic and transabdominal sampling procedures were attempted in 28 and 14 cases, respectively, with \u3e90% success obtaining targeted tissue. Varying degrees of autolysis were present in all samples and precluded histopathologic scoring of 6% of 122 biopsies. Greater autolysis in duodenal samples was seen with longer postmortem interval (Beta = 0.06, 95% confidence interval, 0.02-0.11). Histopathologic features identified included duodenal Paneth and goblet cell depletion. Acute inflammation was absent but chronic inflammation was prevalent in both upper and lower enteric samples. Severe chronic rectal inflammation was identified in children as young as 5.5 weeks.
CONCLUSIONS: Minimally invasive postmortem intestinal sampling is feasible and identifies histopathology that can inform mortality contributors
Minimally invasive postmortem intestinal tissue sampling in malnourished and acutely ill children is feasible and informative
BACKGROUND: Intestinal disorders such as environmental enteric dysfunction (EED) are prevalent in low- and middle-income countries (LMICs) and important contributors to childhood undernutrition and mortality. Autopsies are rarely performed in LMICs but minimally invasive tissue sampling is increasingly deployed as a more feasible and acceptable procedure, although protocols have been devoid of intestinal sampling to date. We sought to determine (1) the feasibility of postmortem intestinal sampling, (2) whether autolysis precludes enteric biopsies\u27 utility, and (3) histopathologic features among children who died during hospitalization with acute illness or undernutrition.
METHODS: Transabdominal needle and endoscopic forceps upper and lower intestinal sampling were conducted among children aged 1 week to 59 months who died while hospitalized in Blantyre, Malawi. Autolysis ratings were determined for each hematoxylin and eosin slide, and upper and lower intestinal scoring systems were adapted to assess histopathologic features and their severity.
RESULTS: Endoscopic and transabdominal sampling procedures were attempted in 28 and 14 cases, respectively, with \u3e90% success obtaining targeted tissue. Varying degrees of autolysis were present in all samples and precluded histopathologic scoring of 6% of 122 biopsies. Greater autolysis in duodenal samples was seen with longer postmortem interval (Beta = 0.06, 95% confidence interval, 0.02-0.11). Histopathologic features identified included duodenal Paneth and goblet cell depletion. Acute inflammation was absent but chronic inflammation was prevalent in both upper and lower enteric samples. Severe chronic rectal inflammation was identified in children as young as 5.5 weeks.
CONCLUSIONS: Minimally invasive postmortem intestinal sampling is feasible and identifies histopathology that can inform mortality contributors
Clinical epidemiology of COVID-19 among hospitalized children in rural western Kenya
The epidemiology of pediatric COVID-19 in sub-Saharan Africa and the role of fecal-oral transmission in SARS-CoV-2 are poorly understood. Among children and adolescents in Kenya, we identify correlates of COVID-19 infection, document the clinical outcomes of infection, and evaluate the prevalence and viability of SARS-CoV-2 in stool. We recruited a prospective cohort of hospitalized children aged two months to 15 years in western Kenya between March 1 and June 30 2021. Children with SARS-CoV-2 were followed monthly for 180-days after hospital discharge. Bivariable logistic regression analysis was used to identify the clinical and sociodemographics correlates of SARS-CoV-2 infection. We also calculated the prevalence of SARS-CoV-2 detection in stool of confirmed cases. Of 355 systematically tested children, 55 (15.5%) were positive and were included in the cohort. The commonest clinical features among COVID-19 cases were fever (42/55, 76%), cough (19/55, 35%), nausea and vomiting (19/55, 35%), and lethargy (19/55, 35%). There were no statistically significant difference in baseline sociodemographic and clinical characteristics between SARS-CoV-2 positive and negative participants. Among positive participants, 8/55 (14.5%, 95%CI: 5.3%-23.9%) died; seven during the inpatient period. Forty-nine children with COVID-19 had stool samples or rectal swabs available at baseline, 9 (17%) had PCR-positive stool or rectal swabs, but none had SARS-CoV-2 detected by culture. Syndromic identification of COVID-19 is particularly challenging among children as the presenting symptoms and signs mirror other common pediatric diseases. Mortality among children hospitalized with COVID-19 was high in this cohort but was comparable to mortality seen with other common illnesses in this setting. Among this small set of children with COVID-19 we detected SARS-CoV-2 DNA, but were not able to culture viable SARs-CoV-2 virus, in stool. This suggests that fecal transmission may not be a substantial risk in children recently diagnosed and hospitalized with COVID-19 infection
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Student Engagement Guidelines: Learning from innovative practices introduced in response to COVID-19
This guidance document was produced as part of the Student Experience and Student Expectations in a post-pandemic teaching and learning environment Collaborative Enhancement Project. The team collected data from ten participating universities through a student survey and focus groups. As a result of the survey, they gathered important quantitative data on students’ perspectives on engagement. For example, participating students ranked the importance of 31 engagement criteria from ‘not at all’ to ‘extremely’ important, indicating their priorities for what they view as student engagement
High-throughput assay for determining enantiomeric excess of chiral diols, amino alcohols, and amines and for direct asymmetric reaction screening
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