Is there a suburban sleeping sickness in Libreville?

Background

The transmission of sleeping sickness occurs primarily in rural areas, and exposed populations are those living from rural activities such as agriculture, fishing, animal husbandry or hunting. However, urban and suburban foci are more and more reported in T. b. gambiense areas. In Libreville town, sleeping sickness cases are regularly diagnosed. In order to investigate about the establishment of a transmission cycle of that disease, we have carried out an entomological survey in two quarters in the vicinity of the town.

Methods

Vavoua traps were set out in all suitable biotopes for tsetse flies during four days and examined twice a day. Flies were collected, identified and dissected.

Results

Two species of Glossina were caught: G. palpalis palpalis (90.58%) and G. caliginea (9.42%). A total infection rate of 9.37% was observed after dissection of all non-teneral flies captured.

Conclusion

These results suggest the establishment of a trypanosomiasis transmission cycle in the area. No salivary gland was found infected. Given that infected persons are regularly detected, we can think about the existence of a suburban sleeping sickness focus in Libreville. More analysis is needed concerning the identification of human trypanosomes and the origin of Glossina blood meals that may confirm the existence of that focus.     

Lipomatous tumors and tumors with fatty component: MR imaging potential and comparison of MR and CT results

This retrospective study was performed to assess the potential of magnetic resonance (MR) imaging for demonstrating various types of lipomatous tumors and tumors with fatty component and to compare the results of MR with those of computed tomography (CT). MR examinations of 17 patients with 18 lipomatous tumors (16, benign; two, liposarcoma) and two patients with fibrosarcomas were reviewed; CT scans were available for comparison in all patients. In the 16 benign lesions (12 benign lipomas, two ovarian dermoid cysts, and two renal angiomyolipomas), the fatty component of the tumors was readily demonstrated by both MR and CT. The T1 and T2 relaxation times and spin density of benign lipomatous tumors were in a range similar to those of normal subcutaneous fat. Differentiation between lipomas and liposarcomas was achieved with both MR and CT. On MR images using a short repetition time (TR = .5 sec), liposarcomas (long T1) were imaged with a lower MR intensity than lipomas (short T1).     

Apoptosis and resolution of experimental renal infective tubulointerstitial nephritis

Summary: Resolution of tubulointerstitial nephritis represents an important step in limiting renal fibrogenesis. However, the mechanism of this resolution remains poorly understood. to determine if apoptosis has a role in this process, we studied its incidence in an experimental model of renal infection and scarring, induced by direct inoculation of Escherichia coli into the renal cortex of Sprague-Dawley rats. the focal lesion produced was studied in animals killed at various time points up to 100 days post inoculation. Apoptosis was identified by electron microscopy (EM) and in-situ labelling of fragmented DNA using terminal transferasemediated deoxy-uridine-5'-triphospate (UTP) nick end labelling (TUNEL). Results were compared with morphological assessment of tubulointerstitial cellularity and macrophage localization. Terminal transferasemediated UTP nick end labelling localized apoptosis to interstitial cells, tubular casts and occasional tubular epithelia and double labelling demonstrated apoptotic body incorporation in macrophages. Interstitial cellularity was maximum at day 3, decreasing significantly by 100 days ( P < 0.01). the incidence of interstitial apoptosis was increased by 3 days and remained significantly higher than day 0 controls throughout ( P < 0.05). Tubular cellularity was significantly less than in control animals throughout the experimental time period. Although the rate of tubular apoptosis was increased, this difference was not statistically significant. In conclusion, apoptosis may represent an important mechanism in the reduction of tubulointerstitial cellularity after experimental renal infection. This in turn, may be important in limiting subsequent interstitial scarring.     

Increased hepatocyte CYP2E1 expression in a rat nutritional model of hepatic steatosis with inflammation

BACKGROUND & AIMS: Nonalcoholic steatohepatitis is morphologically identical to alcoholic hepatitis and has multiple etiologic associations and an unknown pathogenesis. The present study used a rat nutritional model of hepatic steatosis with inflammation to test the hypothesis that induction of the alcohol-inducible hepatic cytochrome P450 (CYP) 2E1 is associated with production of steatohepatitis. METHODS: Rats received a diet devoid of methionine-choline. CYP2E1 protein was detected in liver sections by immunohistochemistry and in hepatic microsomal fractions by immunoblotting; CYP2E1 activity was detected by N-demethylation of N,N-dimethylnltrosamine (NDMA). CYP2E1 messenger RNA was analyzed by Northern blotting and slot blot hybridization. RESULTS: After 4 weeks of methionine-choline devoid diet, macrovesicular steatosis and an inflammatory infiltrate were prominent in hepatic acinar zone 3. CYP2E1 immunostaining was increased and had a more extensive acinar distribution corresponding to that of the steatosis. Microsomal CYP2E1 protein, NDMA activity, and hepatic CYP2E1 messenger RNA levels were all correspondingly increased. CONCLUSIONS: CYP2E1 is induced, partly at a pretranslational level, in this experimental form of steatohepatitis. The finding of biochemical and histological similarities between this nutritional model of hepatic steatosis with inflammation and alcoholic hepatitis indicates possible clues to common pathogenetic mechanisms. The relevance of this finding to human nonalcoholic steatohepatitis remains uncertain and requires further investigation of human liver specimens. (Gastroenterology 1996 Dec;111(6):1645-53)