Synergistic induction of apoptosis in human endothelial cells by tumour necrosis factor-alpha and transforming growth factor-beta

Serum deprivation stimulates endothelial apoptosis while albumin inhibits this and has been proposed as important in confining apoptotic remodelling to poorly perfused vessels. Tumour necrosis factor (TNF)-alpha and transforming growth factor (TGF)-beta are also reported to induce endothelial apoptosis. To investigate the comparative roles of these stimuli, the effect of TNF-alpha and TGF-beta, alone or in combination, in the presence or absence of serum or albumin was studied. There was strong synergy between the cytokines in inducing human umbilical vein endothelial cell apoptosis, but only in the absence of serum. Synergy was destroyed by boiling cytokines and was not affected by polymyxin B. Dose response experiments revealed greater activity of TGF-beta(1) than TGF-beta(2). The synergy was protein synthesis dependent and apoptosis was confirmed by DNA gel electrophoresis, transmission electron microscopy and FACS analysis. Data suggests a role for synergistic activation of endothelial cell apoptosis by TNF-alpha and TGF-beta(1) but perhaps only in poorly perfused vessels deprived of serum factors.     

Phylogenetic classification of transporters and other membrane proteins from Saccharomyces cerevisiae

On the basis of functional and phylogenetic criteria, we have identified a total of 229 subfamilies and 111 singletons predicted to carry out transport or other membrane functions in Saccharomyces cerevisiae. We have extended the Transporter Classification (TC) and created a Membrane Classification (MC) for non-transporter membrane proteins. Using the preliminary phylogenetic digits X, Y, Z (for new families, subfamilies, and clusters, respectively), we allocated a five-digit number to 850 proteins predicted to contain more than two transmembrane domains. Compared with a previous TC of the yeast genome, we classified an additional set of 538 membrane proteins (transporters and non-transporters) and identified 111 novel phylogenetic subfamilies. Electronic Publication     

Evaluation of adolescent statural growth in health and disease: reliability of assessment from height measurement series and development of an automated algorithm

OBJECTIVES: The precise evaluation of adolescent growth spurt is necessary for numerous clinical research studies of growth disorders and treatments. The objectives of our study were: (1) to evaluate the reliability of clinicians' 'manual' evaluation of the adolescent growth spurt from a collected series of height data, and (2) to construct an automated algorithm to determine the duration of the two phases of growth in health and disease (spurt and final slow growth) independent of clinical pubertal stages. METHODS: One hundred and seventy-four growth curves of normally growing, GH-deficient and Turner's syndrome subjects were presented twice to 2 experienced clinicians. Disagreement between evaluations and clinicians were settled to obtain a 'consensual gold standard' evaluation versus which the algorithm was assessed. Kappa statistics and Bland-Altman analyses were used to evaluate the reliability and agreement of the evaluations. RESULTS: The reliability of 'manual' evaluation of adolescent growth spurt from collected series of height data appeared to be poor. Conversely, the developed algorithm is perfectly reliable and satisfactorily valid. Discrepancies with the clinical consensual gold standard were always fewer than the discrepancies between the expert clinicians, and were observed in similarly difficult curves. CONCLUSION: The developed algorithm may be useful for diverse clinical and biological research applications in children with growth disorders. This study also confirms the value of a comprehensive investigation of growth during adolescence independent of clinical staging.     

Structural analysis of the oligosaccharide alditols released from the jelly coat of Rana dalmatina eggs by reductive beta-elimination

A combination of ion-exchange chromatography and high performance liquid chromatography (HPLC) has been used to separate the reduced oligosaccharides produced by alkaline borohydride degradation of oviducal mucins obtained from the jelly coat of Rana dalmatina. The primary structures of 26 O-glycans were determined by one-dimensional and two-dimensional 1H and 1H13C NMR spectroscopy. As observed for 20 other amphibian species, these carbohydrate chains are highly species-specific. The main typical feature of the species R. dalmatina consists in the presence of the backbone Gal(beta1-3)[Gal(beta1-4)]Gal(beta1-3)GalNAc-ol, previously observed among Ranidae, such as R. temporaria and R. ridibunda. Nevertheless, the nature of carbohydrates present at the periphery of the glycans perfectly differentiates the three species.     

A single enzyme catalyses formation of Trypanothione from glutathione and spermidine in Trypanosoma cruzi

Protozoa of the order Kinetoplastida differ from other organisms in their ability to conjugate glutathione (l-gamma-glutamyl-cysteinyl-glycine) and spermidine to form trypanothione [N(1),N(8)-bis(glutathionyl)spermidine], a metabolite involved in defense against chemical and oxidant stress and other biosynthetic functions. In Crithidia fasciculata, trypanothione is synthesized from GSH and spermidine via the intermediate glutathionylspermidine in two distinct ATP-dependent reactions catalyzed by glutathionylspermidine synthetase (GspS; EC ) and trypanothione synthetase (TryS; EC ), respectively. Here we have cloned a single copy gene (TcTryS) from Trypanosoma cruzi encoding a protein with 61% sequence identity with CfTryS but only 31% with CfGspS. Saccharomyces cerevisiae transformed with TcTryS were able to synthesize glutathionylspermidine and trypanothione, suggesting that this enzyme is able to catalyze both biosynthetic steps, unlike CfTryS. When cultures were supplemented with aminopropylcadaverine, yeast transformants contained glutathionylaminopropylcadaverine and homotrypanothione [N(1),N(9)-bis(glutathionyl)aminopropylcadaverine], metabolites that have been previously identified in T. cruzi, but not in C. fasciculata. Kinetic studies on recombinant TcTryS purified from Escherichia coli revealed that the enzyme displays high-substrate inhibition with glutathione (K(m) and K(i) of 0.57 and 1.2 mm, respectively, and k(cat) of 3.4 s(-1)), but obeys Michaelis-Menten kinetics with spermidine, aminopropylcadaverine, glutathionylspermidine, and MgATP as variable substrate. The recombinant enzyme possesses weak amidase activity and can hydrolyze trypanothione, homotrypanothione, or glutathionylspermidine to glutathione and the corresponding polyamine.     

Preliminary examination on lapillus utility for otolith increment analysis in Malawian cyprinid <Emphasis Type="Italic">Engraulicypris sardella</Emphasis>

Features and increments of otoliths in Engraulicypris sardella were observed. The sagitta was arrowhead shaped with an obvious core and rostra, the latter being fragile and easily destroyed by extracting and grinding processes. Increments around the core were readable but not in rostra. The lapillus was round fan-shaped with an obvious core. Increments in the lapillus were clearly deposited from the core to the margin. The asteriscus had an ambiguous core that led to difficulty in discerning the first increment and had fewer increments than the lapilli. Thus, the lapillus is the most appropriate for reading otolith increments.     

HIV-AIDS: ethics in healthcare,research, and access to treatments

Violence and gravity cannot be ignored when considering HIV and AIDS challenges. However, coping with this pandemic disease caused us to build up and experience new ways of solidarity that have transformed our views of medical care and public health. The few achievements of these years throw a new light on the figure of the ill person. They brought new references allowing a different understanding of the political stakes of public health. Partnership or even therapeutic alliance are now a framework to the understanding of respect, solidarity and equity. New viewpoints exist on the health care relationship. Our achievements show at first injustice in the access of treatments at the international level. They make clear our moral responsibilities toward every person that require a treatment. This idea should be emphasized when applied on the most vulnerable communities. The most urgent challenges that remain today are extreme precariousness situations, treatment access conditions, information, and quality of life.