Visualization of Insulin-Loaded Nanocapsules: In Vitro and in Vivo Studies After Oral Administration to Rats

Purpose. Biodegradable poly(isobutylcyanoacrylate) nanocapsules have been recognized as a promising carrier for oral administration of peptides and proteins. In the present study, we investigate the fate of insulin-loaded nanocapsules by fluorescence and transmission electron microscopy (TEM) after intragastric force-feeding to rats. Methods. Insulin-, Texas-red^®-labeled insulin, or gold-labeled insulin-loaded nanocapsules were first characterized. Rats received a single dose of nanocapsules (diameter 60-300 nm, 57 IU insulin/kg) by intragastric force-feeding. After 90 min, ileum was isolated and prepared for fluorescence and transmission electron microscopy. Results. Nanocapsules were observed on both sides of the gut epithelium and in blood capillaries. In M-cell-free epithelium, apparently intact nanocapsules could be seen in the underlying tissue, suggesting they could cross the epithelium and carry the encapsulated peptide. In M-cell-containing epithelium, nanocapsules appeared degraded in the vicinity of macrophages. It is noteworthy that intestinal absorption of nanocapsules was observed without artifacts forcing the nanocapsules to stay in the gut. Conclusions. Based on TEM observations, this study shows the intestinal absorption of biodegradable nanocapsules leading to the transport of insulin across the epithelium mucosa. The fate of the nanocapsules appeared different depending on the presence or the absence of M cells in the intestinal epithelium.     

Microbial quality assessment of some street food widely consumed in Ouagadougou,Burkina Faso

The major part of the population of Ouagadougou, Burkina Faso, have their breakfast, dinner and lunch in street food shops. The characteristics of street food vendors are indicated. It appeared clearly that women play a major part (75%) in street food sale. Vendors have only a slight knowledge of food processing and of hygienic practices. There is a high proportion (about 50%) of people among them. This dietary habit has some negative aspects on the consumers' health. Ours studies clearly showed that hygienic practices during sales operations are not respected by all categories of vendors of food products. Also, it was observed that street food vendors sometimes sit close to the waste water drainage system and solid wastes. Sometimes, the food is not covered and it is manipulated by consumers in areas infested by flies and others insects. The water used to wash the materials is of poor quality. The second aspects of our studies showed that, in most cases, when the safety and hygienic practices were not respected, the food became a true microorganism culture medium under tropical climatic conditions. A table reports microbial analysis and contamination rates of some important street foods consumed in Ouagadougou. In general these results showed the failure of microbial quality of some food which is not preheated (milk product, fruit juice, vegetable, fruit) and in the case of food which is not reheated after a long time of exposition (dry meat and meat on sticks). The presence of Salmonella and Shigella species in some food represents a serious danger for consumers. These aspects were observed with most street food vendors. It probably makes street food the source of most diseases caused by bacteria and other microorganisms.     

Optimization of risk stratification for anticoagulation-associated intracerebral hemorrhage: net risk estimation

Journal of Neurology - Every anticoagulation decision has in inherent risk of hemorrhage; intracerebral hemorrhage (ICH) is the most devastating hemorrhagic complication. We examined whether...     

Occurrence of Vibrio cholerae in water reservoirs of Burkina Faso

Africa is currently an important region in which cholera epidemics occur. Little is known about the presence of Vibrio cholerae in freshwater bodies in Africa. There are ca. 1700 lakes and reservoirs in Burkina Faso, most of which have been built within recent decades to secure water resources. The purpose of this study was to investigate the presence of V. cholerae in the water of reservoirs, using the most-probable-number polymerase chain reaction. Results showed that V. cholerae could be detected in water samples collected from 14 of 39 sampled reservoirs. The concentrations varied from 0 MPN/l to more than 1100 MPN/l. Fifty strains of V. cholerae isolated on CHROMagar? vibrio were identified as V. cholerae non-O1/non-O139, none of which carried the ctxA gene.A significant positive correlation was found between the presence of V. cholerae in the reservoirs and both alkaline pH and phytoplankton biomass. V. cholerae was present in significantly higher numbers in reservoirs of urban areas than in rural areas. Since V. cholerae non-O1/non-O139 has been shown to be a causative agent of endemic diarrheal outbreaks, their presence in Burkina Faso reservoirs suggests they may play a role in gastroenteritis in that country.     

Mineral constituents and toxicological profile of Jateorhiza macrantha (Menispermaceae) aqueous extract

Ethnopharmacological relevance

Jateorhiza macrantha is a medicinal plant used in popular medicine to treat several diseases, including cardiovascular disorders. To date, there is no documented report available on the toxicological profile of this medicinal plant.

The aim of the study

The present study was carried out to investigate the mineral content and the safety of the oral administration of the leaf aqueous extract of Jateorhiza macrantha in mice.

Materials and methods

The presence of Ca, Mg, K, Na, Cu, Mn, Fe and Zn in the extract was analyzed using Atomic Absorption Spectrophotometer. In the acute toxicity study, Male and female Balb-C mice were administered single doses of 2.5 and 5 g/kg of body weight by gavage, and were monitored for 7 days. In the subacute toxicity study, the extract was administered by gavage at doses of 150, 300 and 600 mg/kg body weight daily for 6 weeks to mice (8 mice/dose/sex). After this period of treatment, 5 mice per sex and per group were sacrificed. The rest of animals per group were observed without any treatment for 2 weeks. After the treatments, some biochemical and hematological parameters were analyzed.

Results

Our findings indicate the presence of all mineral elements tested. Acute study indicates no signs of toxicity at the doses used. The LD₅₀ value is >5.00 g/kg body weight, since there was no death registered at that dose. In subacute study, hematological and biochemical parameters showed a significant decrease in platelet and significant increases in ALT and AST in both sexes and creatinin levels only in male suggesting that some compounds of the plant extract were responsible of disturbances of hematopoiesis, liver and kidney functions.

Conclusions

Our results show that Jateorhiza macrantha acute toxicity towards animals is very low. However, in subacute administration, this extract induces slight injuries on hematopoiesis, liver and kidney functions, suggesting its use with caution.     

Seasonal patterns of Plasmodium falciparum gametocyte prevalence and density in a rural population of Burkina Faso

Gametocytes are the malaria parasite stages that secure the transmission from the human host to the mosquito. The identification of natural parameters that influence gametocyte carriage can contribute to a better understanding of the dynamics of the sexual stage parasites for transmission reducing strategies. A total of 3400 blood slide readings were done during four cross-sectional surveys (2002-2003) including all age groups to determine the effect of season on Plasmodium falciparum gametocytes in a seasonal malaria transmission area of Burkina Faso. Entomological data were collected to determine the malaria transmission intensity in relation to seasons. Transmission intensity was estimated by monthly EIRs, averaging 28 and 32 infective bites/person/month in the wet seasons of 2002 and 2003, respectively. The EIR in the dry seasons was below one infective bite/person/month. The gametocyte prevalence was significantly higher at the start and peak of the wet season compared to the dry season when corrected for asexual parasite density and age. Gametocyte density significantly increased during the wet season after correction for asexual parasite density and age. In this study, season appears to be an independent parameter that determines gametocyte prevalence and density and should be considered to be included in epidemiological studies on malaria transmission.