Background In African settings with poor access to health care, surveillance and surveys of disease burden are often done through home visits. The optimal recall period to capture data on symptoms ...and health utilization is unknown. Methods We collected illness data among 53 000 people during fortnightly home visits in rural and urban Kenya. Dates of cough, fever and diarrhoea in the past 2 weeks and health-seeking behaviour were recorded. Incidence rates were modelled using Poisson regression for data collected from 1 July 2006 to 30 June 2007. Results Incidence rates were higher in days 0–6 before the home visit than in days 7–13 before the home visit for all three symptoms, for the rural and urban sites, for children and adults, for self- and proxy-reported symptoms and for severe and non-severe illness in children. Recall decay was steeper in the rural than the urban sites, and for proxy- than self-reported symptoms. The daily prevalence of symptoms fell <80% of the maximum prevalence when asking about symptoms >3 days before the home visit for children and >4 days for persons ≥5 years of age. Recall of previously documented clinic visits, and prescriptions of antimalarials and antibiotics also declined by ∼7, 15 and 23% per week, respectively, in children aged <5 years, and 6, 20 and 16%, respectively, in older persons (P < 0.0001 for each decline). Conclusions A 2-week recall period underestimates true disease rates and health-care utilization. Shorter recall periods of 3 days in children and 4 days in adults would likely yield more accurate data.
We describe an automated method for the isolation of human pancreatic islets. The procedure meets the following requirements: 1) minimal traumatic action on the islets, 2) continuous digestion in ...which the islets that are progressively liberated can be saved from further enzymatic action, 3) minimal human intervention in the digestion process, and 4) high yield and purity of the isolated islets. After purification on Ficoll gradients, an average of 164,600 islets/pancreas was obtained (2279 islets/g), with an average purity of 78.5% islets. The average volume and average insulin content of the final islet preparation were 348 mm3 and 93.4 U, respectively. The islets were morphologically intact with a normal degree of beta-granulation and responded to glucose stimulation with a fivefold increase of insulin secretion over basal levels. The procedure is now being used for the initiation of the second phase of clinical trials on human islet transplants.
Islet transplantation is a treatment option for type I diabetic patients. Preservation of human pancreata prior to islet isolation using two‐layer method with perfluorocarbon (PFC) and University of ...Wisconsin solution (UW) results in twofold increase in islet yields. The objective of this study was to determine the mechanism by which islets undergo apoptosis and determine PFC's effects on this process. Gene array analysis was used to analyze the expression of pro‐ and anti‐apoptotic genes in islets isolated from pancreata preserved under varying conditions. A 12‐fold increase in the expression of inhibitor of apoptosis (IAP) and survivin was observed in islets isolated from pancreata preserved in PFC. This was accompanied by decreased expression of BAD (3.7‐fold), BAX (2.7‐fold) and caspases (5.2‐fold). Levels of activated caspase‐9 (77.98%), caspase‐2 (61.5%), caspase‐3 (68.3%) and caspase‐8 (37.2%) were also reduced. ‘Rescue’ of pancreata after storage (12 h) in UW by preservation using PFC also resulted in a down‐regulation of pro‐apoptotic genes and inhibition of caspase activation. Apoptosis observed in islets from all groups was mainly mitochondria‐dependent, mediated by change in redox potential initiated by hypoxia. We demonstrate that reduction in hypoxia of pancreata preserved using PFC leads to significant up‐regulation of anti‐apoptotic and inhibition of pro‐apoptotic genes.
This study of human islets isolated from pancreata preserved in perfluorocarbon showed decreased expression of proapoptotic genes bad, bax and caspases, and decreased apoptosis via the mitochondrial pathway, as well as increased expression of inhibitor of anti‐apoptotic genes IAP and survivin.
This commentary describes how diabetes research using human pancreatic islets has been drastically altered over the past six months, due to COVID is based on the IIDP experience and on interviews ...conducted with IIC staff members and IIDP recipient investigators.
Background. The epidemiology and burden of influenza remain poorly defined in sub-Saharan Africa. Since 2005, the Kenya Medical Research Institute and Centers for Disease Control and Prevention–Kenya ...have conducted population-based infectious disease surveillance in Kibera, an urban informal settlement in Nairobi, and in Lwak, a rural community in western Kenya. Methods. Nasopharyngeal and oropharyngeal swab specimens were obtained from patients who attended the study clinic and had acute lower respiratory tract (LRT) illness. Specimens were tested for influenza virus by realtime reverse-transcription polymerase chain reaction. We adjusted the incidence of influenza-associated acute LRT illness to account for patients with acute LRT illness who attended the clinic but were not sampled. Results. From March 2007 through February 2010, 4140 cases of acute LRT illness were evaluated in Kibera, and specimens were collected from 1197 (27%); 319 (27%) were positive for influenza virus. In Lwak, there were 6733 cases of acute LRT illness, and specimens were collected from 1641 (24%); 359 (22%) were positive for influenza virus. The crude and adjusted rates of medically attended influenza-associated acute LRT illness were 6.9 and 13.6 cases per 1000 person-years, respectively, in Kibera, and 5.6 and 23.0 cases per 1000 person-years, respectively, in Lwak. In both sites, rates of influenza-associated acute LRT illness were highest among children < 2 years old and lowest among adults > 50 years old. Conclusion. In Kenya, the incidence of influenza-associated acute LRT illness was high in both rural and urban settings, particularly among the most vulnerable age groups.
To determine the effects of procedural modifications, 23 human islet isolations were analyzed. Isolations were divided into two groups based on the enzyme used. The influence of Liberase™, with an ...improved method of mechanical disassociation of pancreas, was compared to an automated method using Sevac collagenase. Pancreases were processed within 10 h of cross clamping. Following ductal injection of the enzyme, tissue was placed in the digestion chamber for disassociation. Purification was accomplished using a COBE 2991 cell processor and continuous gradients of Hypaque EuroFicoll.
Isolations in Group I (Sevac) had an average yield of 138,602 ± 128,364 islet equivalents (IE) (2083 ± 1679 IE/g) with a purity of 85 ± 11%. Group II (Liberase) showed an average yield of 389,586 ± 191,161 IE (5,958 ± 3,083 IE/g) with a purity of 90 ± 6.8%. Viability was confirmed by fluorescein diacetate and propidium iodide staining, static incubations, and perifusions. In conclusion, the combination of the enzyme blend, Liberase, and a more gentle system of disassociation has proven to be a more productive method of islet isolation with higher purity than the previously published methods.
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