IVIA - Ibero-American VLBI Initiative -Progress on the Brazilian side.

IVIA is a joint initiative of at least 8 Latin-American countries plus Portugal and Spain to make good use of large telecommunications antennas that are out of service in these countries, because most international communications are now using submarine cables. The first step will be to refurbish the antennas and then to start doing single dish observations of radiosources. In a second step the antennas will be equipped with VLBI (Very Long Base Interferometry) equipment, to establish a VLBI network.

Development in lipid drugs.

Lipopeptide lipid moieties induce dendritic cell (DC) internalization and epitopes are recognized by MHC, the major histocompatibility complex. HIV-1 (human immunodeficiency virus type 1) lipopeptide vaccine candidate elicits immune responses, and sustains HIV control after highly active antiretroviral therapy (HAART). Mp- and Dp-MART (anti-melanoma lipopeptides) induce strong CTL (cytolytic T lymphocyte) response.

Human immunodeficiency virus and host cell lipids. Interesting pathways in research for a new HIV therapy.

It has been reported in the literature that biological membranes arising from HIV-induced cell fusion, as well as syncytium formation between infected and non-infected cells and those involved in transduction, viral DNA nuclear import and virion budding from the host cell, are all made of proteins, a phospholipid (P) bilayer and cholesterol (C). However, the P/C molar ratio is higher in the retroviral envelope than in the plasma membrane where they originate, and higher than in the nuclear envelope. Mechanisms are described which elucidate this puzzling fact, as well as cholesterol-dependent leakage and pore formation during cell fusion.

Lipids and retroviruses.

The role that lipids may play in enveloped viruses is reviewed. Small lipid molecules can influence retrovirus binding to cell receptors, plasma membrane fusion, and transcription. Palmitoylation following myristoylation of viral glycoproteins is required at the transmembrane level for signal transduction as well as for virion budding and maturation.

Fructose-induced enhanced mitogenicity of diploid human cells: possible relationship with cell differentiation.

Fructose strongly stimulates the growth of normal diploid human skin fibroblasts (SFs) and induces marked changes in their morphology and lipid accumulation. This mitogenic effect occurs despite very low fructose consumption and depends on the presence of glutamine. The cell kinetics of cultured fructose-fed human skin fibroblasts were different from those fed on glucose: in the presence of fructose a high proliferative index persisted at Day 14 of culture and the duration of the total cell cycle and of the G1 + 1/2 M and S phases was slightly shorter.

Delta 5-3 beta-hydroxysteroid acyl transferase activity in the rat brain.

Pregnenolone and dehydroepiandrosterone accumulate in brain as sulfate and fatty acid esters and unconjugated steroids. The steroid fatty acid ester-synthesizing activity was investigated in rat brain microsomes. Endogenous fatty acids in the microsomal fraction were used for the esterification of steroids.

Effects of polyunsaturated fatty acids on human and rat cells. In vitro versus in vivo experiments.

Human infant skin fibroblasts and liver cells were subcultured with 250 microM PUFA (polyunsaturated fatty acid), and primary cultures of glial brain cells from new-born rats with 100 microM; oleic acid was added to controls. Minimum essential medium (MEM) supplemented with bovine serum was used as a reference. During the short-term experiment (18-24 h), control liver cells showed a regular increase in protein level, while protein increment was more rapid in linoleic and especially in arachidonic acid-treated cells, but only for the first 3 hours.

Cholesterol and prostaglandin synthesis by cultured human skin fibroblasts in the Alagille syndrome involving paucity of interlobular bile ducts.

Children with Alagille syndrome show high serum cholesterol (15-20 mmol/L). To establish correlation of this unusual level of cholesterol with the regulation of cholesterol metabolism, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGR) activity and synthesis of cholesterol, fatty acids and acidic steroids from [14C]acetate were determined in cultured skin fibroblasts from 2-3 year old children. Prostaglandin E2 (PGE2) synthesis and nucleic acid synthesis were determined in cells when they were growing in medium containing normal, Alagille or fetal bovine serum.

Permissive role of n-6 polyunsaturated fatty acids on carbohydrate oxidation in human infant skin fibroblasts: one possible mechanism of their intervention on coronary heart disease and diabetes.

Unlabelled: Many publications indicate the beneficial effect of n-6 polyunsaturated fatty acids (n-6 PUFAs) in the control of coronary heart disease and diabetes, although the mechanism is not clear. Some of our previous results suggest that, in contrast to other lipids, n-6 PUFAs could have a permissive effect on carbohydrate oxidation. To check this hypothesis, we determined pyruvate dehydrogenase (PDH, decarboxylase: EC 1.

Extent of 14C incorporation into cholesterol of infant skin fibroblasts incubated with carboxyl-labeled oleic, -linoleic or -arachidonic acid.

In order to determine the incorporation of C1-14C derived from mono- and poly-unsaturated fatty acids into cholesterol of human cells cultured in exponential phase, infant skin fibroblasts (SF) were used at the 5th passage. On Day 6, the SF were preincubated 36 h in a medium containing 5 per cent lipoprotein-deficient serum, and thereafter [1-14C] oleic, -linoleic or -arachidonic acid-without (OL1, LI1 and AR1 group SF), or with the addition of 0.25 mM cold fatty acids (OL2), LI2 and AR2 group SF).

Effects of methyl mercury and triethyllead on Na+K+ATPase and pyruvate dehydrogenase activities in glioma C6 cells.

The effect of methyl mercury (MeHg) and triethyllead (Et3Pb) on the membrane bound SH-enzymes Na+K+ATPase and pyruvate dehydrogenase (PDH) was studied in relation to the effect on the galactosyl ceramide sulfotransferase (CST) and to morphological changes in glioma C6 cells. Two-day-old cultures were incubated for 1 or 20 hrs with 5-30 microgram MeHgC1 and 2-8 microgram Et3PbC1/mg cell protein. The results show that both compounds induced morphological changes and a reduction of CST activity at growth inhibitory concentrations.

Pyruvate dehydrogenase activity in the liver, brain and adipose-tissue of lipid-deprived developing rats. Effect of minute amounts of polyunsaturated fatty acids.

Unlabelled: The present experiment was carried out using the following diets: FF, fat-free, and LP in same diet with 0.7% sunflower oil - given to the progeny of females kept on the FF diet since the mating. after 10 mM Mg2+ activation of the PDH phosphatase, and rate of [1-14C[ pyruvate decarboxylation into acetyl-CoA ester units was determined in the liver, brain and adipose-tissue of the pair-fed developing rats.

Cholesterol synthesis in the liver, kidneys and brain after injection of uniformly 14C-labeled oleic or linoleic acid to developing rats.

6-day-old suckling rats, born to females kept on a fat-free diet, were used to determine cholesterol and fatty acid specific radioactivity (SRA) in the liver, kidneys and brain, after injection of 3 microCi uniformly 14C-labeled linoleic acid (ULI) or oleic acid (UOL). 1 h after injection, cholesterol SRA was highest in the liver and kidneys, and then decreased when UOL was injected. Cholesterol SRA peaked 3 h after injection of ULI in liver and kidneys.

[Cholesterol ester storage disease in children. Comparative biochemistry of hepatocyte and fibroblast cultures].

The results of biochemical studies in three children with cholesterol ester storage disease are reported. This rare disease (13 published cases) and the related Wolman's disease are characterised by a deficiency of acid lipase. Affected children mostly present with isolated hepatomegaly.

Children sea-blue histiocytosis (2 cases) compared with phospholipidosis induced by 4-4' DET (4-4' p (diethylamino-2-ethoxy phenyl) 3-4 hexane) in rat.

Two cases of children with liver and spleen enlargement are reported. Sea-blue histiocytes and Pick cells were found in both cases in liver, spleen, bone marrow and blood. Further more, lysobisphodphatidic acids were identified in phospholipid analysis of liver biopsies and cultived liver cells.

[Fetal and neo-natal development of brown adipose tissue in guinea pigs and rats. Feto-maternal or milk transfer of essential fatty acids : lipogenesis and morphology (author's transl)].

Brown adipose tissue (BAT) lipogenesis (fatty acid, glycerol and CO2 synthesis) and its morphology determined by optical microscopy, were studied in guinea pigs and rats during intra-uterine life and during the suckling period. Following the receptor induction and after the commencement of the hormone sensitive adenylate-cyclase/lipase system (i.e.

[Adenylate cyclase/Lipase. Hormone receptor induction].

An adenylate cyclase activity (AC) was found in guinea pig brown adipose tissue (BAT), since the tissue's apparition. This enzymatic activity increased during the development and showed high values at the end of gestation. An increase of AC units per cell was observed, in addition to the cell multiplication.

[A possible essential metabolite of linoleic acid: lipoic acid, the universal coenzyme of alpha-keto acid oxidation].

The metabolism of [14C-U] linoleci acid (LI) and [14C-U] oleic acid were compared by injecting these fatty acids into growing rats and then homogenizing livers into a three phase system (chloroform/methanol/water). The radioactivities of these phases were equilibrated by extracting them X times with the same solvents. The lipid lower phase was discarded and the analysis was carried out on the evaporated hydroalcoholic upper phase.