Evidence of two genetic entities inBothriocephalus funiculus (Cestoda) detected by arbitrary-primer polymerase chain reaction random amplified polymorphic DNA fingerprinting

The genetic diversity of two samples of Cestoda (Bothriocephalus funiculus, Renaud and Gabrion, 1984) parasitizing two sympatric teleostean species was assessed using random amplified polymorphic DNA (RAPD). A total of 72Bothriocephalus were analyzed individually, and electrophoretic analysis of the amplification products of 65 primers among the 68 tested revealed monomorphic patterns, reflecting the close genetic relatedness within and between the parasites of the two samples. However, 3 primers showed polymorphic patterns at 6 RAPD sites. Analysis of the distribution of these genomic fragments, assuming random mating, showed strong linkage disequilibria (only 8 genetic combinations were observed among the 32 expected). Two genetic entities displaying a high degree of host specificity were evidence within our two samples ofB. funiculus. This powerful molecular technique can be used as a diagnostic tool in studies concerning the biodiversity of related genetic entities and could have broad applications in parasitology.     

The pleiotropic functions of peroxisome proliferator-activated receptor γ

Peroxisome proliferator-activated receptors (PPARs) are nuclear hormone receptors, initially described as molecular targets for synthetic compounds that induce peroxisome proliferation. PPARgamma is the best characterized of the PPARs. The heterodimer of PPARgamma with the retinoid X receptor (RXR) plays a crucial role in adipogenesis and insulin sensitization. The RXR/PPARgamma heterodimer furthermore has been reported to have important immunomodulatory activities and to affect cell proliferation/differentiation pathways in various malignancies. PPARgamma is activated by a number of naturally occurring fatty acid derivatives and by several synthetic compounds, including the thiazolidinediones and L-tyrosine-based insulin sensitizers. This review gives an overview of the pleiotropic functions of PPARgamma and discusses the wide-ranging medical implications that modulation of PPARgamma activity might have for various diseases, ranging from obesity and type 2 diabetes to cancer and inflammation.     

Increased chloride permeability of amphibian epithelia treated with aldosterone

The transepithelial flux of chloride was increased by aldosterone treatment of amphibian skin and bladder and this was reflected by increased shunt conductance. The hormonal effect depended on the presence of chloride on the epithelial side of the preparation. These changes in tissue conductance and chloride permeability appear to be a direct effect of aldosterone as they did not occur when sodium transport was stimulated with vasopressin or hypotonicity.Chloride efflux was reduced in magnitude by indacrinone and DIDS, as well as after removal of chloride from the solution on the epithelial side of the preparations. These results suggest that, rather than merely diffusing along (a) paracellular pathway(s), chloride flows through (a) cellular structure(s), notably mitochondria-rich cells. These cells can therefore be considered as targets for aldosterone.Presented in part before the Belgian Physiological Society (Beauwens et al. 1985)     

Immune status and uptake of antiretroviral interventions to prevent mother-to-child transmission of HIV-1 in Africa

The aim of this study performed in Abidjan, C?te d'Ivoire, was to describe the distribution of CD4+ T-cell lymphocytes (CD4) in HIV-1-infected (HIV+) pregnant women diagnosed during prenatal voluntary counseling and testing and to assess whether HIV-related immunodeficiency influenced the acceptance of an antiretroviral (ARV) package (zidovudine beginning at 36 weeks of amenorrhea plus intrapartum nevirapine) to prevent mother-to-child transmission. Between April and June 2002, a CD4 count was systematically performed in all HIV+ women (n=221) in 5 antenatal clinics carrying out voluntary counseling and testing. No difference in CD4 count was found in HIV+ women who did not return for their test result (n=50) and those who were informed of their positive serostatus (n=171) (median CD4 count: 389/mm3 vs. 420/mm3; P=0.19). We also found a lack of difference in CD4 count in those who accepted ARV (n=72) and those who did not but knew their HIV status (n=99) (median CD4 count: 405/mm3 vs. 425/mm3; P=0.47). The overall uptake of the intervention (31.9%) appeared to be independent of the maternal immune status.     

Campylobacter fetus bloodstream infection: risk factors and clinical features

In this paper, we report 21 cases of Campylobacter fetus bloodstream infection observed in our institution over a 9-year period. The median age of the patients was 78 years. Most of them (62%) had a significant underlying disease, such as diabetes, immunodeficiency or cardiovascular disease. The main clinical features were fever with (62% of cases) or without (38%) extra-intestinal symptoms. These included mycotic aneurysm of the abdominal aorta (24%) and cellulitis (19%). Antibiotic treatment was mainly based on amoxicilline-clavulanate (57%) or imipenem (21%), for a median duration of 28 days. A favourable outcome was observed in 72% of cases. Death directly attributable to infection was observed for three patients, due to the rupture of an infected aneurysm or relapsing bloodstream infection with septic shock. All patients initially treated with imipenem had a favourable outcome. This report adds evidence that C. fetus bloodstream infection should be suspected in elderly patients with fever, immunodeficiency and cardiovascular damages. Imipenem seems to be the most active drug, especially in severe cases.     

Oxytocin localization and function in the A1 noradrenergic cell group: ultrastructural and electrophysiological studies

Antibodies to oxytocin and noradrenalin were utilized in an immunocytochemical study of the caudal ventrolateral medulla of the rat brainstem. Noradrenalin was visualized by using antibodies to noradrenalin and by means of a silver-gold intensification of diaminobenzidine, whereas oxytocin could be demonstrated in the same section by using the diaminobenzidine precipitate as a marker. At the light microscopic level, oxytocin fibers were densely distributed around the A1 cell bodies. At the ultrastructural level, oxytocin-containing fibers were seen to terminate synaptically onto noradrenalin-containing neurons. Previous studies have shown that electrical stimulation of A1 neurons selectively activates vasopressin-secreting neurons in the supraoptic nucleus. Therefore, separate electrophysiological studies were set up, in which we observed that oxytocin infusions (100-200 pg) into the A1 area enhanced the activity of 16 out of 19 putative vasopressin-secreting neurons and elicited no response from any of 10 oxytocin-secreting neurons. This finding suggests that some of the parvicellular neurons in the paraventricular nucleus of the hypothalamus, from which the A1 neurons derive their oxytocin innervation, can activate the A1 cell group via this peptidergic neurotransmitter. One of the consequences of A1 neuronal activation is enhanced firing of hypothalamic supraoptic (and paraventricular) vasopressin-secreting neurons, and a consequent rise in plasma vasopressin.     

Saethre‐Chotzen syndrome: Notable intrafamilial phenotypic variability in a large family with Q28X TWIST mutation

Saethre‐Chotzen syndrome is an autosomal dominant disease characterized by craniosynostosis, ptosis, and limb and external ear abnormalities. Variable expressivity is a well‐known phenomenon in this disorder. A large Indian family has been recently identified as carrying a nonsense TWIST mutation (Q28 X) in 17 members, of whom 16 were examined in detail. Only 4 (25%) of the patients showed patent craniostenosis, namely, oxycephaly. The penetrance of craniosynostosis in this family is lower than previously reported in the literature. Fifteen patients (93%) had moderate to severe ptosis. Minor limb and external ear abnormalities were present in most patients. Eyelid features were the hallmark of the disease for 12 members of the family, suggesting that mutations in TWIST may lead to a phenotype with mainly palpebral features and no craniostenosis. The clinical analysis of this large family clearly illustrates the significant variable expressivity, probably related to haploinsufficiency because of the TWIST mutation. This phenotypic variability remains unclear but could be the result of modifier genes and/or genetic background effect, as noticed previously in the transgenic twist‐null heterozygous mice. © 2002 Wiley‐Liss, Inc.