Islet Formation during the Neonatal Development in Mice

The islet of Langerhans is a unique micro-organ within the exocrine pancreas, which is composed of insulin-secreting beta-cells, glucagon-secreting alpha-cells, somatostatin-secreting delta-cells, pancreatic polypeptide-secreting PP cells and ghrelin-secreting epsilon-cells. Islets also contain non-endocrine cell types such as endothelial cells. However, the mechanism(s) of islet formation is poorly understood due to technical difficulties in capturing this dynamic event in situ. We have developed a method to monitor beta-cell proliferation and islet formation in the intact pancreas using transgenic mice in which the beta-cells are specifically tagged with a fluorescent protein. Endocrine cells proliferate contiguously, forming branched cord-like structures in both embryos and neonates. Our study has revealed long stretches of interconnected islets located along large blood vessels in the neonatal pancreas. Alpha-cells span the elongated islet-like structures, which we hypothesize represent sites of fission and facilitate the eventual formation of discrete islets. We propose that islet formation occurs by a process of fission following contiguous endocrine cell proliferation, rather than by local aggregation or fusion of isolated beta-cells and islets. Mathematical modeling of the fission process in the neonatal islet formation is also presented.     

Perception of donor breast milk and determinants of its acceptability among mothers in a developing community: a cross-sectional multi-center study in south-east Nigeria

Background

Due to the health and economic benefits of breast milk, the World Health Organization (WHO) recommends that for infants who cannot receive breast milk from their own mothers, the next preferred option is donated breast milk. This recommendation is however rarely practiced in most developing countries where donor milk is not widely accepted.

Methods

This cross-sectional multi-center study enrolled mothers attending antenatal or pediatric clinics in six tertiary institution in south-east Nigeria using purposive and convenient sampling method. Data collection was done using pretested questionnaires. The study aimed to assess the knowledge, acceptability and willingness to donate breast milk and/or use donated breast milk for their infants It also explored factors that determine this behavior.

Results

A total of 1235 mothers participated; 39% (480/1225) have heard about the concept of donor milk, while only 10% (79/759) and 7% (81/1179), respectively, had adequate knowledge of the concept and policy on donor milk. Sixty percent indicated willingness to use donor milk or donate breast milk if need arises. Respondents with lower age (p?=?0.049) and with higher occupational status (p?=?0.001) were more likely to have adequate knowledge of donor breast milk, while respondents with lower educational attainment (p?=?0.002) and those who are non-Christians (p?=?0.004) were more likely to request financial inducement for donating their breast milk. Adequate knowledge of the concept of donor milk (p?=?0.001), preference of donor milk to infant formula (p?=?0.001) and requirement of financial remuneration (p?=?0.001) were the only significant predictors of willingness to donate and/or receive donated breast milk.

Conclusion

The knowledge of the concept of donor breast milk and awareness of policies regulating its practice in Nigeria is low, but the prospect of its acceptability is high among mothers surveyed in south-east Nigeria. Targeted public education by relevant government agencies in collaboration with clinicians, community and religious leaders about the concept of donor breast milk to families may help increase the acceptance and practice of donating breast milk and/or use of donated breast milk among mothers in the region.

     

Phytochemical analysis and toxicological evaluation of the ethanolic Leaves extract of Hypoestes rosea on the morphology and biochemical indices of the Kidneys of albino Wistar Rats

BackgroundHypoestes rosea (family: Acanthacea), has been harnessed and utilized for treatment of several ailments. However, there is the paucity of available data on nephrotoxicity associated with this herb. Here, we investigated the phytochemical profile and toxicological effect of H. rosea on Wistar Rats.MethodsTwenty rats (weight range: 75–100 g) were assigned into five study groups, viz; (a) control (without treatment) (b) treatment group 1, orally administered with 50 mg/kg (c) treatment group 2, orally administered with 100 mg/kg (d) treatment group 3, orally administered with 250 mg/kg, and (e) treatment group 4, orally administered with 300 mg/kg of H. rosea, respectively for 28 days of four rats per group. The rats were made unconscious by using oral administration of chloroform. Cardiac punctures were made, and blood samples collected into 10 ml labeled plain container, allowed to clot and spun to harvest serum for determination of sodium, potassium, chloride, bicarbonate, urea and creatinine using colorimetric, back-titrimetric, Urease-Berthelot and Jaffe’s reaction methods respectively. Kidneys of rats were harvested, weighed and immediately fixed in 10% neutral buffered formalin for histological analysis.ResultMean serum sodium (p = 0.049), potassium (p = 0.007), and urea (p < 0.001) levels were significantly higher among the treatment groups compared to controls. Histopathological findings of kidney sections revealed mild glomerular infiltration in treatment groups 2–4. Additionally, sclerosis was observed in groups 3–4. Phytochemical analysis of H. rosea revealed presence of alkaloids, flavonoids, saponins, tannins, terpenoids, steroids and reducing sugars.ConclusionFrom the findings in this study, H. rosea leaf extract causes significant damage to the kidneys of Wistar rats at higher doses. Of which, the damages were dose-dependent in direct proportionality manner. To better determine the safe dosage and ideal duration of consumption, there is the need for further studies on H. rosea.     

Staphylococcal infections and infertility: mechanisms and management

Molecular and Cellular Biochemistry - Membrane lipids regulate the structure and function of G protein-coupled receptors (GPCRs). Previously we have shown that membrane cholesterol regulates the...     

Effects of Extreme Climate Events on Tea (Camellia sinensis) Functional Quality Validate Indigenous Farmer Knowledge and Sensory Preferences in Tropical China

Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world''s most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in a major tea producing area of China during an extreme drought through the onset of the East Asian Monsoon in order to capture effects of extreme climate events that are likely to become more frequent with climate change. Compared to the spring drought, tea growth during the monsoon period was up to 50% higher. Concurrently, concentrations of catechin and methylxanthine secondary metabolites, major compounds that determine tea functional quality, were up to 50% lower during the monsoon while total phenolic concentrations and antioxidant activity increased. The inverse relationship between tea growth and concentrations of individual secondary metabolites suggests a dilution effect of precipitation on tea quality. The decrease in concentrations of tea secondary metabolites was accompanied by reduced farmer preference on the basis of sensory characteristics as well as a decline of up to 50% in household income from tea sales. Farmer surveys indicate a high degree of agreement regarding climate patterns and the effects of precipitation on tea yields and quality. Extrapolating findings from this seasonal study to long-term climate scenario projections suggests that farmers and consumers face variable implications with forecasted precipitation scenarios and calls for research on management practices to facilitate climate adaptation for sustainable crop production.     

In vitro formation of neuroclusters in microfluidic devices and cell migration as a function of stromal-derived growth factor 1 gradients

Central nervous system (CNS) cells cultured in vitro as neuroclusters are useful models of tissue regeneration and disease progression. However, the role of cluster formation and collective migration of these neuroclusters to external stimuli has been largely unstudied in vitro. Here, 3 distinct CNS cell types, medulloblastoma (MB), medulloblastoma-derived glial progenitor cells (MGPC), and retinal progenitor cells (RPC), were examined with respect to cluster formation and migration in response to Stromal-Derived Growth Factor (SDF-1). A microfluidic platform was used to distinguish collective migration of neuroclusters from that of individual cells in response to controlled concentration profiles of SDF-1. Cell lines were also compared with respect to expression of CXCR4, the receptor for SDF-1, and the gap junction protein Connexin 43 (Cx43). All cell types spontaneously formed clusters and expressed both CXCR4 and Cx43. RPC clusters exhibited collective chemotactic migration (i.e. movement as clusters) along SDF-1 concentration gradients. MGPCs clusters did not exhibit adhesion-based migration, and migration of MB clusters was inconsistent. This study demonstrates how controlled microenvironments can be used to examine the formation and collective migration of CNS-derived neuroclusters in varied cell populations.     

A comparative study of gut microbiomes in captive nocturnal strepsirrhines

Feeding strategy and diet are increasingly recognized for their roles in governing primate gut microbiome (GMB) composition. Whereas feeding strategy reflects evolutionary adaptations to a host's environment, diet is a more proximate measure of food intake. Host phylogeny, which is intertwined with feeding strategy, is an additional, and often confounding factor that shapes GMBs across host lineages. Nocturnal strepsirrhines are an intriguing and underutilized group in which to examine the links between these three factors and GMB composition. Here, we compare GMB composition in four species of captive, nocturnal strepsirrhines with varying feeding strategies and phylogenetic relationships, but nearly identical diets. We use 16S rRNA sequences to determine gut bacterial composition. Despite similar husbandry conditions, including diet, we find that GMB composition varies significantly across host species and is linked to host feeding strategy and phylogeny. The GMBs of the omnivorous and the frugivorous species were significantly more diverse than were those of the insectivorous and exudativorous species. Across all hosts, GMBs were enriched for bacterial taxa associated with the macronutrient resources linked to the host's respective feeding strategy. Ultimately, the reported variation in microbiome composition suggests that the impacts of captivity and concurrent diet do not overshadow patterns of feeding strategy and phylogeny. As our understanding of primate GMBs progresses, populations of captive primates can provide insight into the evolution of host‐microbe relationships, as well as inform future captive management protocols that enhance primate health and conservation.     

Asymptomatic Malaria in Refugees Living in a Non-Endemic South African City

Background

Asymptomatic malaria infection in refugees is both a threat to the lives of the individuals and the public in the host country. Although South Africa has been experiencing an unprecedented influx of refugees since 1994, data on malaria infection among refugees is lacking. Such information is critical since South Africa is among the countries that have planned to eliminate malaria. The objective of this study was to determine prevalence of asymptomatic malaria infection among a refugee population living in a city of KwaZulu-Natal province, South Africa.

Methods and Findings

A survey was conducted on adult refugee participants who attended a faith-based facility offering social services in a city of KwaZulu-Natal province, South Africa. The participants were screened for the presence of malaria using rapid diagnostic tests and microscopy. Demographic data for the participants were obtained using a closed ended questionnaire. Data was obtained for 303 participants consisting of 51.5% females and 47.5% males, ranging from 19 to 64 years old. More than 95% of them originated from sub-Saharan African countries. Two hundred and ninety participants provided a blood sample for screening of malaria. Of these, 3.8% tested positive for rapid diagnostic test and 5.9% for microscopy. The majority of malaria infections were due to Plasmodium falciparum.

Conclusions

The study confirms the presence of asymptomatic malaria infections among a refugee population residing in a city of KwaZulu-Natal province that is not endemic for malaria. The results have important implications for both public health and malaria control in South Africa, particularly since the country has decided to eliminate malaria by 2018. To achieve this goal, South Africa needs to expand research, surveillance and elimination activities to include non-endemic areas, particularly with high refugee populations. We further recommend use of powerful diagnostic tests such as PCR for these interventions.     

Circadian rhythms in myocardial metabolism and contractile function: influence of workload and oleate

Multiple extracardiac stimuli, such as workload and circulating nutrients (e.g., fatty acids), known to influence myocardial metabolism and contractile function exhibit marked circadian rhythms. The aim of the present study was to investigate whether the rat heart exhibits circadian rhythms in its responsiveness to changes in workload and/or fatty acid (oleate) availability. Thus, hearts were isolated from male Wistar rats (housed during a 12:12-h light-dark cycle: lights on at 9 AM) at 9 AM, 3 PM, 9 PM, and 3 AM and perfused in the working mode ex vivo with 5 mM glucose plus either 0.4 or 0.8 mM oleate. Following 20-min perfusion at normal workload (i.e., 100 cm H(2)O afterload), hearts were challenged with increased workload (140 cm H(2)O afterload plus 1 microM epinephrine). In the presence of 0.4 mM oleate, myocardial metabolism exhibited a marked circadian rhythm, with decreased rates of glucose oxidation, increased rates of lactate release, decreased glycogenolysis capacity, and increased channeling of oleate into nonoxidative pathways during the light phase. Rat hearts also exhibited a modest circadian rhythm in responsiveness to the workload challenge when perfused in the presence of 0.4 mM oleate, with increased myocardial oxygen consumption at the dark-to-light phase transition. However, rat hearts perfused in the presence of 0.8 mM oleate exhibited a markedly blunted contractile function response to the workload challenge during the light phase. In conclusion, these studies expose marked circadian rhythmicities in myocardial oxidative and nonoxidative metabolism as well as responsiveness of the rat heart to changes in workload and fatty acid availability.