[Comparison of annual risk for tuberculosis infection (1994-2001) in school children in Djibouti: methodological limitations and epidemiological value in a hyperendemic context]. / Comparaison du risque annuel d'infection tuberculeuse (1994-2001) auprès d'enfants scolarisés à Djibouti: limites méthodologiques et intérêt épidémiologique dans un contexte hyperendémique.

The purpose of this report was to describe a tuberculin survey conducted in 2001 to assess the trend in the annual risk for tuberculosis infection in Djibouti and compare resulting data with those obtained in a previous survey conducted in 1994. In 2001 cluster sampling allowed selection of 5599 school children between the ages of 6 and 10 years including 31.2% (1747/5599) without BCG vaccination scar. In this sample the annual risk of infection (ARI) estimated using cutoff points of 6 mm, 10 mm, and 14 mm corrected by a factor of 1/0.82 and a mode value (18 mm) determined according to the "mirror" method were 4.67%, 3.64%, 3.19% and 2.66% respectively. The distribution of positive tuberculin skin reaction size was significantly different from the normal law. In 1994 a total of 5257 children were selected using the same method. The distribution of positive reactions was not significantly different from the gaussian distribution and 28.6% (1505/5257) did not have a BCG scar. The ARI estimated using cutoff points of 6 mm, 10 mm, and 14 mm corrected by a factor of 1/0.82 and a mode value (17 mm) determined according to the "mirror" method were 2.68%, 2.52%, 2.75% and 3.32 respectively. Tuberculin skin reaction size among positive skin test reactors was correlated with the presence of a BCG scar, and its mean was significantly higher among children with BCG scar. The proportion of positive skin test reactors was also higher in the BCG scar group regardless of the cutoff point selected. Comparison of prevalence rates and ARI values did not allow any clear conclusion to be drawn, mainly because of a drastic difference in the positive reaction distribution profiles between the two studies. The distribution of the skin test reaction's size 1994 study could be modelized by a gaussian distribution while it could not in 2001. A partial explanation for the positive reaction distribution observed in the 2001 study might be the existence of cross-reactions with environmental mycobacteria.

Modulation of carbohydrate metabolism and peptide hormones by soybean isoflavones and probiotics in obesity and diabetes.

Soybean and its isoflavones have been shown to have beneficial effects on carbohydrate and lipid metabolism and on renal function. Probiotics may potentiate the beneficial effects of isoflavones by converting the inactive isoflavone glycoside to aglycones, which are biologically active, thereby producing a synergistic effect. We therefore studied the effects of soybean isoflavones in the presence and absence of probiotics on glucose and triglyceride metabolism and the peptide hormones involved in their metabolism. Lean and obese SHR/N-cp rats were fed AIN-93 diets containing 0.1% soybean isoflavone mixture, 0.1% probiotics mixture or both. Plasma was analyzed for glucose, triglycerides, parameters of renal function and peptide hormones -- insulin, leptin, glucagon and ACTH -- that are involved in glucose and lipid metabolism. Isoflavones given alone lowered plasma glucose in both phenotypes while triglyceride was decreased only in lean animals. Isoflavones also lowered aspartate amino transferase and alanine amino transferase in both phenotypes. Isoflavones had significant effect on plasma insulin, leptin and glucagon in lean rats but not in obese rats. Thus, our data show that in lean animals, isoflavones have hypoglycemic and hypolipidemic effect, and the effect is mediated by changes in peptide hormones. When lipid levels are very high as in obese rats, isoflavones fail to lower plasma triglyceride levels. Probiotics do not appear to enhance the effect of isoflavones.

Proinflammatory cytokines and the hypermetabolism of children with sickle cell disease.

Sickle cell anemia (HbSS) includes chronic inflammation, but the origin is unclear. We hypothesized that in stable HbSS patients the inflammation was associated with hypermetabolism. We compared selected hypermetabolic and key immunomodulator indicators in HbSS versus control children and examined associations between measures of hypermetabolism and inflammation. Twelve fasting asymptomatic HbSS children 6-12 years and 9 controls matched for age, gender and fat mass (FM) were studied. Proportional reticulocyte count (retic%) and resting energy expenditure (REE) represented hypermetabolism, and C-reactive protein (CRP) indicated inflammation. Proinflammatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6), chemokine monocyte chemoattractant protein-1 (MCP-1), and energy balance cytokine leptin were measured. Methods were indirect calorimetry, enzyme-linked immunosorbent assay, and radioimmunoassay. Statistical analysis included simple correlation and regression analysis. REE (51 +/- 6 vs. 43 +/- 12 kcal/kg per fat-free mass (FFM), mean +/- SD), retic% (12 +/- 4 vs. 0.7 +/- 0.3%), CRP (5 +/- 3 vs. 0.3 +/- 0.4 mg/liter), and IL-6 (71 +/- 40 vs. 20 +/- 7 pg/ml) were significantly higher for HbSS than controls (P < 0.05). Conversely, leptin (0.1 +/- 0.1 vs. 2 +/- 1 microg/liter per kgFM) and MCP-1 (34 +/- 5 vs. 41 +/- 4 pg/ml) were significantly lower for the HbSS subjects (P < 0.01). TNF-alpha was not significantly different. There were no significant associations between REE or retic% and any cytokine measured. However, CRP was significantly associated with REE in HbSS (r = 0.8, P = 0.003) and an important predictor of REE/FFM. We provide new evidence for low circulating levels of inflammatory chemokine MCP-1 in stable HbSS children, confirm mostly low cytokine levels, inflammation, and hypermetabolism and demonstrate association of hypermetabolism with inflammation via CRP but not via cytokines.

Effects of soybean isoflavones, probiotics, and their interactions on lipid metabolism and endocrine system in an animal model of obesity and diabetes.

The effects of soybean isoflavones with or without probiotics on tissue fat deposition, plasma cholesterol, and steroid and thyroid hormones were studied in SHR/N-cp rats, an animal model of obesity, and were compared to lean phenotype. We tested the hypothesis that probiotics by promoting the conversion of isoflavone glycosides to their metabolically active aglycone form will have a synergistic effect on body fat, cholesterol metabolism, and the endocrine system. Obese and lean SHR/N-cp rats were fed AIN-93 diets containing 0.1% soy isoflavone mixture, 0.1% probiotic mixture, or both together. Different fat tissues were teased and weighed. Plasma was analyzed for cholesterol and steroid and thyroid hormones. In both phenotypes, isoflavones lowered fat deposition in several fat depots. Probiotics alone had no significant effect on fat depots. Isoflavones lowered total, LDL, and HDL cholesterol in lean rats, but in obese rats isoflavones lowered only total and LDL cholesterol. Isoflavones also lowered many of the steroid hormones involved in lipid metabolism but had no significant effect on thyroid hormones. Probiotics had no significant effect on cholesterol or hormones. Thus, our data show that soy isoflavones also lower plasma cholesterol and that this hypocholesterolemic effect appears to be due in part to the modulation of steroid hormones. Probiotics do not seem to enhance the effect of isoflavones.

Dietary flaxseed meal is more protective than soy protein concentrate against hypertriglyceridemia and steatosis of the liver in an animal model of obesity.

OBJECTIVE: Soy protein and flaxseed meal have been reported to have beneficial effects on many chronic diseases in humans and animals. The primary objective of the study was to evaluate the beneficial effects of soy protein and flaxseed meal on hypertriglyceridemia and liver steatosis associated with obesity and diabetes. We compared the effects of dietary soy protein and flaxseed meal with that of casein on plasma and liver lipids in a genetic model of obesity, type II diabetes and insulin resistance, namely the SHR/N-cp rat. METHODS: Lean and obese phenotypes of SHR/-cp rats were fed AIN 93 diets containing 20% of energy from casein (control), soy protein concentrate or flaxseed meal for six months. Plasma was analyzed for total cholesterol, LDL cholesterol, triglyceride and total protein. Liver was analyzed for steatosis by light microscopy after staining samples with Hematoxylin-Eosin and Oil-Red-O. RESULTS: In lean rats soy protein and flaxseed meal significantly decreased plasma total cholesterol (26.0% and 20.3% respectively) compared to casein. In obese rats flaxseed meal had significant cholesterol lowering effect compared to control rats (41%). Soy protein significantly lowered both plasma LDL-cholesterol and HDL-cholesterol in lean phenotypes while in obese phenotypes flaxseed meal significantly lowered LDL-cholesterol and HDL-cholesterol compared to casein-fed rats. Flaxseed meal also significantly lowered plasma triglyceride in both lean and obese rats compared to casein fed rats (33.7% and 37% respectively). There was significantly greater fat accumulation in livers of obese rats than lean rats (200%) regardless of dietary protein type. Flaxseed meal significantly lowered fat deposition in livers of both lean and obese rats compared to rats fed casein or soy protein. Dietary component(s) present in flaxseed meal or soy protein responsible for hypolipidemic effects is not clear. CONCLUSIONS: The marked hypotriglyceridemic and hypocholesterolemic effects of flaxseed meal may have important therapeutic implications in patients with hypertriglyceridemia and hypercholesterolemia and deserve further study in humans with these disorders. Flaxseed meal supplementation may provide a new therapeutic strategy to reduce hypertriglyceridemia and fatty liver.

[Tuberculosis and HIV infection: experience of the national tuberculosis prevention program in Djibouti: 1990-1996]. / Tuberculose et infection VIH l'experience du programme national de lutte antituberculeuse de Djibouti: 1990-1996.

Based on analysis of data collected from the national tuberculosis prevention program in Djibouti between 1990 and 1996, the authors analyzed the relationship between HIV infection and tuberculosis. The study cohort comprised a total of 22,000 patients including 14,000 with documented HIV infection. Although HIV infection probably worsened the situation, it was neither the only nor the main factor involved in the resurgence of tuberculosis. Demographic growth, higher population density, and increasing poverty as well as the quality of the national tuberculosis prevention program must be taken into account. The incidence of smear-negative tuberculosis was not significantly higher in HIV-infected patients (incidence of smear positive cases, > 92%). Extrapulmonary tuberculosis especially of pleural involvement was more common (15% versus 9.4%). Treatment was effective in HIV-infected patients. If directly observed (DOT) therapy was used, there was no risk of emergence of multidrug-resistant tuberculosis strains. Drug side-effects associated with the protocols used in Djibouti were not greater in HIV-infected patients. Most additional mortality observed in HIV-infected tuberculosis patients (10.5% versus 2%) was due to progression of HIV infection.

The effect of dietary menhaden, olive, and coconut oil fed with three levels of vitamin E on plasma and liver lipids and plasma fatty acid composition in rats.

The effect of dietary fats with varying degrees of unsaturation in the presence of different concentrations of vitamin E on tissue lipid levels was studied in rats. Rats were fed either menhaden oil, olive oil or coconut oil at 15% levels with either 0.1, 0.3 or 0.6 mg/g of vitamin E as alpha-tocopherol for four weeks. Rat serum and liver were analyzed for total cholesterol, HDL-cholesterol, triacylglycerol and phospholipids. In addition, fatty acid composition of serum lipids was also analyzed. Serum total cholesterol and triacylglycerol were significantly lower in rats fed menhaden oil than in those fed olive or coconut oil, while the HDL-cholesterol was significantly higher in serum of rats fed menhaden and olive oil than in those fed coconut oil. Levels of vitamin E in the diet had only a significant effect on serum cholesterol and liver phospholipids. The Pearson correlation coefficient showed a significant positive relationship between serum triacylglycerol and total cholesterol, and a negative correlation between triacylglycerol and HDL-cholesterol, and between total and HDL-cholesterol.In the liver, total cholesterol was significantly higher in rats fed coconut oil than in rats fed menhaden oil. Total liver phospholipids were lower in rats fed either coconut oil or olive oil compared to those fed menhaden oil, especially with higher levels of vitamin E intake. Higher levels of vitamin E in the diet appear to increase triacylglycerol and phospholipids in livers of rats fed menhaden oil. In the liver a significant negative correlation was observed between phospholipids and cholesterol. The type and degree of unsaturation (polyunsaturated fatty acids in menhaden oil, monounsaturated fatty acids in olive oil and saturated fatty acids in coconut oil) significantly affected plasma and tissue lipids.

Differential effects of dietary flaxseed protein and soy protein on plasma triglyceride and uric acid levels in animal models.

The effect of dietary soy protein and flaxseed meal on metabolic parameters was studied in two animal models, F344 rats with normal lipid levels and obese SHR/N-cp rats with elevated levels of cholesterol and triglyceride. The rats were fed AIN 93 diet differing only in the source of protein. The rats were fed either 20% casein, 20% soy protein or 20% flaxseed meal. Plasma was analyzed for cholesterol, triglyceride, uric acid, blood urea nitrogen (BUN), creatinine and total protein. In both strains of rats, flaxseed meal significantly decreased plasma cholesterol and triglyceride concentrations. The effect of soy protein on lipids was not as striking as that of flaxseed meal. Flaxseed meal also lowered uric acid in F344 rats and BUN in SHR/N-cp rats. Since cholesterol, triglyceride and uric acid are independent risk factors for cardiovascular disorders, our data show that both flaxseed meal and soy protein may have beneficial effects. Which chemical constituent(s) of flaxseed meal or soybean is (are) responsible for the beneficial effects need to be identified.