Physiological role of the putative ammonium transporter RhCG in the mouse.

Ammonium excretion into urine is a major process essential to the regulation of acid-base homeostasis. We have shown that Rh-type proteins, including renal RhCG, belong to the Mep/Amt family of ammonium transporters and promote bi-directional ammonium transport upon heterologous expression in yeast. To study the physiological role of RhCG and to test a potential function in ammonium excretion, we have generated mice bearing an invalidation of the corresponding gene.     

What is the place of electroneuromyographic studies in the diagnosis and management of pudendal neuralgia related to entrapment syndrome?

Entrapment of the pudendal nerve may be at the origin of chronic perineal pain. This syndrome must be diagnosed because this can result in the indication of surgical decompression of the entrapped nerve for pain relief. Electroneuromyographic (ENMG) investigation is often performed in this context, based on needle electromyography and the study of sacral reflex and pudendal nerve motor latencies. The limits of ENMG investigation, owing to various pathophysiological and technical considerations, should be known. The employed techniques do not assess directly the pathophysiological mechanisms of pain but rather correlate to structural alterations of the pudendal nerve (demyelination or axonal loss). In addition, only direct or reflex motor innervation is investigated, whereas sensory nerve conduction studies should be more sensitive to detect nerve compression. Finally, ENMG cannot differentiate entrapment from other causes of pudendal nerve lesion (stretch induced by surgical procedures, obstetrical damage, chronic constipation...). Thus, perineal ENMG has a limited sensitivity and specificity in the diagnosis of pudendal nerve entrapment syndrome and does not give direct information about pain mechanisms. Pudendal neuralgia related to nerve entrapment is mainly suspected on specific clinical features and perineal ENMG examination provides additional, but no definitive clues, for the diagnosis or the localization of the site of compression. In fact, the main value of ENMG is to assess objectively pudendal motor innervation when a surgical decompression is considered. Perineal ENMG might predict the outcome of surgery but is of no value for intraoperative monitoring.     

Cholecystectomy by celioscopy. Experience in two Upper Normandy hospital units. Apropos of 178 procedures]

Laparoscopic cholecystectomy (LC) emerges as an effective alternative to classical cholecystectomy, but its safety, benefits and indications still need to be clarified. From September 1989 to March 1991, 178 LC were performed by 8 surgeons in 2 hospitals, on 142 women and 36 men with a mean age of 48.2 years. The gall bladder wall was thin in 160 cases and thick in 18 cases (with 6 cases acute cholecystitis). We observed no deaths, 147 simple procedures with a hospital stay and drug requirement lower than with the usual cholecystectomy via laparotomy. But in 21 cases, the procedure needed a laparotomy, and in 10 cases complications occurred, requiring laparotomy in 6 cases. Our results suggest: a) LC is an improvement in the treatment of uncomplicated gallstones; b) a trained surgeon and extreme caution are required in complicated cholelithiasis; c) classical cholecystectomy is still useful in many circumstances.     

Human African trypanosomiasis: MRI

We report a case of human African trypanosomiasis caused by Trypanosoma brucei rhodesiense. After the febrile period of parasite dissemination, the patient had meningeal involvement but normal CT. MRI showed the appearances of meningitis. After two periods of arsenical treatment, a severe encephalopathy occurred suggesting post-therapeutic reactive encephalitis (PTRE). Nevertheless, T2-weighted MRI showed no oedema, but focal bilateral high signal areas in the white matter. PTRE was excluded and a third course of treatment was undertaken. The lesions progressively disappeared. Received: 3 September 1996 Accepted: 30 January 1997     

The effect of hypoxia on acquired drug resistance and response to epidermal growth factor in chinese hamster lung fibroblasts and human breast-cancer cells in vitro

Prolonged hypoxia induced transient drug resistance in Chinese hamster lung fibroblasts. Previously hypoxic cells were resistant to adriamycin and resistant to etoposide. Complete recovery of etoposide sensitivity was observed following re-aeration for 24 hr. A change in P-glycoprotein expression was unlikely to contribute to the resistance caused by hypoxia, since adriamycin resistance was not reversed by verapamil. However, alteration in the plasma membrane structure may be involved, since previously hypoxic cells were resistant to extracellular superoxide radical generated by the addition of xanthine/ xanthine oxidase. In contrast, adriamycin sensitivity was not altered by hypoxia in 3 human breast-cancer cell lines. MDA-468 and MCF-7/Adr differed in their response to EGF, independent of the presence of hypoxia. These results suggest that hypoxic-stress-induced drug resistance is not generalized.     

Is there an association between periodontal condition and HIV infection?

Abstract Individuals in Tanzania who have limited access to medical and dental treatment provide an opportunity to study the natural association between periodontal condition and HIV infection and the stage of infection. 119 HIV infected adult individuals and 73 individuals with AIDS from the AIDS Clinical Trial Clinic at Muhimbili Medical Centre (MMC) in DaresSalaam participated as cases. Mean age was 35.3 and 35.1 years, respectively. 156 individuals with a mean age of 28.3 years, confirmed as HIV seronegative, served as controls. There were no significant differences in bleeding on probing, pocket formation or attachment loss among the HIV seronegative individuals. HIV seropositive and AIDS patients. We applied multiple logistic regression to calculate odds ratios for presence of periodontal conditions adjusting for age, gender and DMFT. Our odds ratios did not reveal any significant associations between bleeding on probing, pocket formation or attachment loss with regard to lymphocyte and CD4+ T cell counts among the HIV infected individuals and AIDS patients. When associations were investigated with regard to HIV serostatus (HIV seronegative. HIV seropositive or AIDS), our adjusted odds ratios were insignificant, too. In fact, most odds ratios were close to 1. Thus, our study supports recent views that the presence, extent and severity of periodontal disease among HIV infected individuals, may be less that hitherto thought.