Jean-Paul Thouvenot

Micronutrient levels in HIV-1-infected children.

DesignProspective study. SettingThe study was performed on HIV-1-infected children at the Paediatric Haematology, and Oncology Unit of Toulouse Hospital, France. PatientsTwenty-one children, suffering from HIV-1 infection, and 21 control subjects of similar age (2–9 years) were included in the study. In the HIV-1-infected children, two subgroups were considered according to stage (non-AIDS or AIDS), based on the Centers for Disease Control, and Prevention 1987 criteria. ResultsThe first statistically significant deficiencies occurred at non-AIDS stage, and were confirmed at AIDS stage: P<0.05 for lycopene, retinol, tocopherol, and P< 0.001 for transthyretin, and serum albumin. Levels of copper (40%), and long-chain polyunsaturated fatty acids (21%) were higher in the non-AIDS group than the controls. ConclusionBiological impairing of the micronutrient levels was observed in the non-AIDS stage without clinical sign. This information is useful in delineating eventual, and well considered nutritional intervention strategies that may improve the clinical status of HIV-1-infected children, and perhaps alter the course of their disease.

Adipose Tissue Proadipogenic Redox Changes in Obesity

The role of inflammation and oxidative stress in the development of obesity and associated metabolic disorders is under debate. We investigated the redox metabolism in a non-diabetic obesity model, i.e. 11-week-old obese Zucker rats. Antioxidant enzyme activities, lipophilic antioxidant (α-tocopherol, coenzymes Q) and hydrophilic antioxidant (glutathione, vitamin C) contents and their redox state (% oxidized form), were studied in inguinal white fat and compared with blood and liver. The adipose tissues of obese animals showed a specific higher content of hydrophilic molecules in a lower redox state than those of lean animals, which were associated with lower lipophilic molecule content and lipid peroxidation. Conversely and as expected, glutathione content decreased and its redox state increased in adipose tissues of rats subjected to lipopolysaccharide-induced systemic oxidative stress. In these in vivo models, oxidative stress and obesity thus had opposite effects on adipose tissue redox state. Moreover, the increase in glutathione content and the decrease of its redox state by antioxidant treatment promoted in vitro the accumulation of triglycerides in preadipocytes. Taken together and contrary to the emergent view, our results suggest that obesity is associated with an intracellular reduced redox state that promotes on its own the development of a deleterious proadipogenic process.

Relationship between the fatty acid composition of rat lymphocytes and immune functions.

The effects of dietary lipids on the fatty acid composition, activation and proliferation of lymphocytes were investigated. Weanling male Wistar rats were fed for 8 weeks on one of two low-fat diets which contained 50 g lipid/kg, or one of two high-fat diets containing 200 g lipid/kg, from either coconut oil or soyabean oil. The fatty acid composition of phospholipids from splenocyte membranes was affected by dietary lipid manipulation, and these differences influenced lymphocyte functions. Increased levels of linoleic acid in spleen lymphocytes correlated negatively with interleukin-2 receptor alpha-chain expression determined either by measuring the mean fluorescence or by the proportion of cells staining positive for CD25, and with the cell proliferation index. However, we found a positive correlation between interleukin-2 receptor alpha-chain expression determined by measuring the mean fluorescence and the cell proliferation index with the oleic acid concentration of spleen lymphocytes. Since phospholipid hydrolysis occurs early in lymphocyte activation, immunosuppressive effects induced by polyunsaturated fatty acids, described in the literature, could be due to an increase of linoleic acid or a decrease of oleic acid affecting many components of plasma-membrane-associated events involved in lymphocyte activation.

Total parenteral nutrition decreases liver oxidative metabolism and antioxidant defenses in healthy rats: comparative effect of dietary olive and soybean oil.

BACKGROUND Total parenteral nutrition (TPN) is used for critically ill patients undergoing surgery, after trauma, or during disease conditions that favor oxidative stress. We studied the effect of TPN on liver oxidative metabolism and antioxidant defenses in rats, and we compared the effect of soybean oil- and olive oil-based diets. METHODS Seven-week-old rats (n = 28) were divided into four groups. Two experimental groups received a TPN solution containing soybean oil (TPN-S) or a mixture of olive/soybean oil, 80/20 (TPN-O), IV for 6 days. Orally fed animals received a solid diet including soybean oil (Oral-S) or olive/soybean oil, 80/20 (Oral-O). The following parameters were measured: DL-alpha-tocopherol, vitamin A, malondialdehyde and thiobarbituric acid reactive substances (MDA-TBARS), and total radical-trapping antioxidant parameter (TRAP) in serum; DL-alpha-tocopherol, vitamin A, glutathione (GSH), and catalase (Cat) activity in liver homogenate; fatty acids from phospholipid, cytochrome P-450 content, NADPH-cytochrome c2 reductase activity in liver microsomes; superoxide dismutase (SOD), glutathione peroxidase (Gpx), glutathione reductase (GR), glutathione transferase (GST), and glucose-6-phosphate dehydrogenase (G6PD) in liver cytosol. RESULTS The soybean or olive oil diets modified the liver microsomal fatty acid phospholipid composition, but the unsaturation index remained unchanged. TPN specifically increased the saturation of the membrane. The cytochrome P-450 level and the NADPH-cytochrome c2 reductase, SOD, Gpx, Cat, and GST activities were unchanged by soybean oil or olive oil diet but decreased receiving TPN. CONCLUSIONS In rats, TPN decreased the liver oxidative metabolism and enzymatic antioxidant defenses. This may be related to saturation of the liver microsomal fatty acids.

Plasma Phospholipid Fatty Acids and Urinary Excretion of Prostaglandins PGE 1 and PGE2 in Infants during Total Parenteral Nutrition, with Continuous or Sequential Administration of Fat Emulsion

During total parenteral nutrition, using an identical supply of fat emulsion (350 mg/kg/24 hr) to correct essential fatty acid deficiency in children, the efficacy of two methods of administration was studied: continuous over 24 hr, or discontinuous 3 hr/day. At the beginning of the study, all the infants (1-4 months old) had proven essential fatty acid deficiency. After at least 1 month of one of the two nutritional protocols (continuous or discontinuous), plasma phospholipid fatty acid composition and PGE1 and PGE2 urinary excretion were measured. The results obtained indicate better utilization of the fat emulsion when it is administered almost every day, in continuous infusion over 24 hr (1 g/kg/24 hr of Intralipid 20%).

Retinol and retinyl ester concentrations in rat tissues during total parenteral nutrition

Abstract We have previously observed that continuous total parenteral nutrition (TPN) that supplies retinyl palmitate induces a strong decrease of the circulating retinol, which is associated with an impaired hepatic production of retinol-binding protein. We have investigated the effect of 7 days of TPN on the retinol and retinyl ester concentrations in rat tissues, relative to the vitamin A status [n = 30 for vitamin A-sufficient (A+) and n = 30 for deficient (A−)]. Rats were cannulated for intravenous feeding (n = 12 for TPN-A+, n = 12 for TPN-A−) and were compared with their per os pair-fed counterparts (n = 12 for O-A+ and n = 12 for O-A−). Retinol and retinoic acid in serum and retinol and retinyl ester concentrations in liver, kidney, lung, heart, and testis were measured by high performance liquid chromatography. TPN induced a dramatic decrease in circulating retinol of A+ rats, whereas retinoic acid concentration in serum was unchanged. When TPN was given to A− rats, retinol concentration in serum remained low. Lower retinol and retinyl ester concentrations were measured in the livers of TPN rats compared with orally pair-fed rats, no matter the initial vitamin A status (P

Retinol storage in the rat liver after daily intramuscular administration of physiological doses of a vitamin A oil emulsion.

We have recently shown the kinetic behavior of liver retinyl esters in rats with adequate vitamin A levels receiving oral vitamin supplementation. In the present work we have studied the effects of intramuscular administration of a vitamin A preparation on the metabolism of vitamin A in the rat. Retinol administered intramuscularly to rats in the form of an emulsion brought about a significant increase in the serum and liver concentration of vitamin A; this increase was slightly less than in orally treated rats. In each group, retinyl palmitate constituted 80-85% of the total retinyl esters, followed by stearate (9-13%), laurate, palmitoleate, myristate, linoleate and pentadecanoate making up 3-10%. The subcellular localization of all retinyl esters is similar and dependent on age but not on the route of administration. These results indicate that although the best hepatic storage is achieved with an orally administered vitamin A emulsion, the intramuscular administration of a physiological dose might provide an effective supplementation method if oral vitamin A is contraindicated.

Fatty acid composition of adipocyte membrane phospholipids and stored triglycerides in infants receiving total parenteral nutrition

Fatty acid (FA) composition of membrane phospholipids (PL) and stored triglycerides (TG) from adipose tissue was studied in eight infants aged 1 to 4 months receiving total parenteral nutrition (TPN) since birth. During this period, essential fatty acid (EFA) intake consisted exclusively of soybean oil emulsion administered by intravenous route (Intralipid 20%) representing 301 +/- 88 mg/kg/24 hr of linoleic acid and 58 +/- 18 mg/kg/24 hr of alpha-linolenic acid, or 2.3 +/- 0.6% and 0.4 +/- 0.1%, respectively, of total energy intake. The results were compared with those of eight control infants of the same age receiving orally a normal milk diet with an intake of 660 +/- 260 mg/kg/24 hr of linoleic acid and 101 +/- 35 mg/kg/24 hr of alpha-linolenic acid, or 4.5 +/- 0.7% and 0.7 +/- 0.3%, respectively, of total energy intake. Although their EFA intake was significantly lower (p less than 0.01) and administered only parenterally, after 1 to 4 months the infants receiving TPN still had a membrane phospholipid FA pattern of adipose tissue which was not significantly different from that of normal children of the same age. In stored adipocyte TG, the percentage of linoleic acid was significantly lower (p less than 0.01) in infants receiving TPN. This is probably of nutritional importance as at this stage of life the child builds up its stores of EFA. The proportion of the other fatty acids in adipocyte TG was not significantly modified.