Male-specific colon motility dysfunction in the TashT mouse line.

BACKGROUND: In Hirschsprung disease (HSCR), the absence of myenteric neural ganglia in the distal bowel prevents motility and thereby causes functional intestinal obstruction. Although surgical resection of the aganglionic segment allows HSCR children to survive this condition, a number of patients still suffer from impaired motility despite having myenteric ganglia in their postoperative distal bowel. Such phenomenon is also observed in patients suffering from other enteric neuropathies and, in both cases, colonic dysmotility is believed to result from abnormalities of myenteric ganglia and/or associated interstitial cells of Cajal (ICC). To better understand this, we used a recently described HSCR mouse model called TashT. METHODS: Intestinal motility parameters were assessed and correlated with extent of aganglionosis and with neuronal density in ganglionated regions. The neural composition of the myenteric plexus and the status of ICC networks was also evaluated using immunofluorescence. KEY RESULTS: TashT(Tg/Tg) mice display a strong male bias in the severity of both colonic aganglionosis and hypoganglionosis, which are associated with male-specific reduced colonic motility. TashT(Tg/Tg) male mice also exhibit a specific increase in nNos(+) neurons that is restricted to the most distal ganglionated regions. In contrast, Calretinin(+) myenteric neurons, Sox10(+) myenteric glial cells, and cKit(+) ICC are not affected in TashT(Tg/Tg) mice. CONCLUSIONS AND INFERENCES: Male-specific impairment of colonic motility in TashT(Tg/Tg) mice is associated with both severe hypoganglionosis and myenteric neuronal imbalance. Considering these parameters in the clinic might be important for the management of postoperative HSCR patients.

[Skin disease and HIV infection among inmates in Lomé, Togo: a study of 194 prisoners]. / Pathologie cutanée et infection à VIH chez les détenus à Lomé, Togo: étude de 194 cas.

OBJECTIVE: The aim of this work was to study the prevalence of skin diseases among inmates in Lomé (Togo) and its relation to their HIV status. PATIENTS AND METHODS: This cross-sectional descriptive study took place from November 14 to December 5, 2011, in the civil prison of Lomé and included prisoners who agreed to have an HIV screening test. RESULTS: In all, 194 prisoners, all men (median age: 29 years), were examined during the study period. The group aged younger than 30 years accounted for 51% of the population. Overall, 166 (85.6%) of the 194 prisoners examined had cutaneous lesions; 153 reported that these had developed after their imprisonment. HIV serology was positive in 21 (10.8%) of the 194 prisoners tested. The most common cutaneous diseases were pruritus (n = 62), fungal infections (n = 45), boils (n = 26), eczema (n = 21), and scabies (n = 20). The frequency of skin disorders did not differ significantly between HIV-infected prisoners and those who were not infected (p>0.05). CONCLUSION: This study shows a potential for high prevalence of HIV infection and an existing high prevalence of infectious dermatosis among these prisoners. It is essential to reduce the overpopulation and crowding in prisons to decrease the prevalence of these skin disorders.

Establishing an insect disease vector functional genomics training center in Africa.

The genome sequences for many insects vector of human diseases are now available and promise the development of a set of new, powerful tools that can be used to develop innovative approaches to control these diseases. The African continent, which is the most severely affected by vector borne diseases, lacks adequate infrastructures and personal resources required for rational use of genomic information. To fill this gap, the African Center for Training in Functional Genomics of Insect vectors of Human Disease (AFRO VECTGEN) was initiated by WHO/TDR and the Department of Medical Entomology and Vector Ecology (DMEVE) of the Malaria Research and Training Center (MRTC) in Mali. The aim of the AFRO VECTGEN program is to train young scientists in functional genomics who will ultimately use genome sequence data for research on insect vector of human disease. The program could trigger collaborative research and will benefit from an existing vector biology network in Mali, which was built around research grants funded by the National Institutes of Health, USA and WHO/TDR.

Reproductive output of female Anopheles gambiae (Diptera: Culicidae): comparison of molecular forms.

Knowledge of ecological differences between the molecular forms of Anopheles gambiae Giles (Diptera: Culicidae) might lead to understanding of their unique contribution to disease transmission, to better vector control, and to identification of the forces that have separated them. We compared female fecundity measured as egg batch size in relation to body size between the molecular forms in Mali and contrasted them with their sibling species, Anopheles arabiensis Patton. To determine whether eggs of different egg batches are of similar "quality," we compared the total protein content of first-stage larvae (L1s), collected < 2 h after hatching in deionized water. Egg batch size significantly varied between An. gambiae and An. arabiensis and between the molecular forms of An. gambiae (mean batch size was 186.3, 182.5, and 162.0 eggs in An. arabiensis and the M and the S molecular form of An. gambiae, respectively). After accommodating female body size, however, the difference in batch size was not significant. In the S molecular form, egg protein content was not correlated with egg batch size (r = -0.08, P > 0.7) nor with female body size (r = -0.18, P > 0.4), suggesting that females with more resources invest in more eggs rather than in higher quality eggs. The mean total protein in eggs of the M form (0.407 microg per L1) was 6% higher than that of the S form (0.384 microg per L1), indicating that the M form invests a greater portion of her resources into current (rather than future) reproduction. A greater investment per offspring coupled with larger egg batch size may reflect an adaptation of the M form to low productivity larval sites as independent evidence suggests.

Impact of land use in catchment and human activities on water, sediment and vegetation of Mediterranean temporary pools.

The vegetation and physical and chemical characteristics of the water and sediment in ten temporary pools submitted to various anthropogenic disturbance were studied in Morocco over two hydrological cycles (1997-1998 and 1998-1999). Results of multivariate and parametric analyses show that disturbance has a significant impact on water and sediment. Agriculture in the catchment resulted in higher levels of N and the use of detergent to higher levels of phosphorus in both water and sediment. Mineral extraction resulted in higher depth and longer duration of flooding. Vegetation characteristics were better correlated to hydrology (water depth, duration of flooding) than to nutrient variables. These results suggest that although agriculture in the catchment contribute in modifying the sediment characteristics, the impact on vegetation and its conservation value is limited. However, care should be taken of the long-term effects of agriculture through cumulative effects and of the possible consequences of changing the agricultural practices.

Bactericidal effects of sugar-fed antibiotics on resident midgut bacteria of newly emerged anopheline mosquitoes (Diptera: Culicidae).

A protocol was developed for significantly reducing resident midgut bacteria in newly emerged anopheline mosquitoes using a combination of antibiotics. Pupa harvested from colony-reared Anopheles gambiae s.l. Giles and Anopheles stephensi (Liston) were placed in cages wiped previously with 70% alcohol and kept under UV light for 24 h. Emerging adult mosquitoes were fed for 3 consecutive days on antibiotic solution, consisting of 0.4% gentamicin sulfate and 1% penicillin-streptomycin solution in a 10% sterile sucrose solution. Bacterial suspensions of Escherichia coli, Klebsiella pneumoniae (Schroeter, 1886), and Pseudomonas stutzeri (Lehmann & Neumann, 1896) isolated from wild-caught anophelines were fed to antibiotic-treated mosquitoes starved for 24 h via either sugar or membrane-feeding. Mosquitoes dissected 1 and 24 h after blood-feeding or sugar-feeding, and plated on trypticase soy agar plates, yielded the same type of bacteria fed originally without evidence of contaminants. There was no residual effect of the antibiotics on introduced single bacteria strains as judged by the presence of bacteria in antibiotic-treated mosquitoes. This experimental reduction of resident midgut bacteria and their replacement with single strains in newly emerged anopheline mosquitoes should facilitate further investigations of the interactions between malaria parasites and bacteria found in the midguts of mosquitoes.

Midgut bacteria in Anopheles gambiae and An. funestus (Diptera: Culicidae) from Kenya and Mali.

Field studies in Kenya and Mali investigated the prevalence of bacteria in the midguts of malaria vectors, and the potential relationship between gram-negative bacteria species and Plasmodium falciparum sporozoites. Midguts were dissected from 2,430 mosquitoes: 863 Anopheles funestus Giles and 1,037 An. gambiae s.l. Giles from Kenya, and 530 An. gambiae s.l. from Mali. An. funestus had a higher prevalence of gram-negative bacteria (28.5%) compared with An. gambiae collected in Kenya and Mali (15.4 and 12.5%, respectively). Twenty different genera of bacteria were identified by gas chromatography from 73 bacterial isolates from mosquito midguts. Pantoea agglomerans (Enterobacter agglomerans) was the most common species identified. There was no association between gram-negative bacteria in the midgut and P. falciparum sporozoites in field-collected An. gambiae s.l. and An. funestus. However, An. funestus females that harbored gram positive bacteria were more likely to be infected with sporozoites compared with those with no cultivable bacteria or gram negative bacteria in their midguts. Habitat-related variation in the prevalence of diverse types of bacteria in mosquitoes could influence malaria parasite development in mosquitoes and corresponding sporozoite prevalence.