Fasting plasma carotenoids concentrations in Crohn's and pancreatic cancer patients compared to control subjects.

Carotenoids are colored molecules that are widespread in the plant kingdom, but animals cannot synthesize them. Carotenes are long, apolar molecules which require fully functioning digestive processes to be absorbed properly. Hence they could be interesting markers of intestinal absorption and digestion. Indeed, only few tests are available to assess these processes and only the D-xylose tolerance test is routinely used. However D-xylose is a sugar that tests only the absorption of water-soluble compounds and it only tests duodenal absorption. In this study, we have evaluated carotenoids as markers of digestion and absorption. We compared fasting plasma carotenoids concentrations in 21 control subjects, 20 patients with Crohn's disease, and 18 patients with pancreatic cancer. Crohn's disease alters intestinal absorption while pancreatic cancer decreases pancreatic enzyme secretion thus impairing digestion. Results show that all carotenoids are significantly lower in Crohn's and cancer patients as compared to control subjects and the multifactorial analysis shows that this decrease is mostly independent of dietary intake. Interestingly, maldigestion as seen in pancreatic cancer more strongly influences plasma lutein and lycopene concentrations while malabsorption in Crohn's disease acts on other carotenoids. Thus carotenoids could be interesting alternatives for testing and following patients that are suspected of having malabsorption or maldigestion syndromes.

Effect of baking process on postprandial metabolic consequences: randomized trials in normal and type 2 diabetic subjects.

OBJECTIVE: To determine the impact of the form, fibre content, baking and processing on the glycaemic, insulinaemic and lipidaemic responses of different French breads. DESIGN AND SUBJECTS: First study: Nine healthy subjects were randomized to consume in a crossover design one of six kinds of French bread (each containing 50 g available carbohydrate): classic baguette, traditional baguette, loaf of wholemeal bread (WM-B), loaf of bread fermented with yeast or with leaven, a sandwich and a glucose challenge as reference. RESULTS: The glycaemic index (GI) values ranged from 57+/-9% (mean+/-s.e.m.), for the traditional baguette, to 85+/-27% for the WM-B. No significant difference was found among the different tested bread. The insulinaemic index (II), however, of the traditional baguette and of the bread fermented with leaven were lower than the other breads (analysis of variance: P<0.01). Postprandial plasma triglycerides showed similar profiles. The traditional baguette tended to decrease postprandial free fatty acids compared to levels after the classic baguette. RESULTS: The GI of the traditional baguette was lower than that of the classic baguette (n=8, venous blood: 70+/-4 vs 75+/-4, P=0.002; capillary blood: 69+/-5 vs 83+/-6, P=0.028, respectively). CONCLUSIONS: Some varieties of French bread (the TB) have lower II, in healthy subjects, and lower GI, in type 2 diabetic subjects, than that of the other varieties. These results might be due to bread processing difference rather than fibre content. SPONSORSHIPS: Supported by grants from the National French Milling Association.

[Recent knowledge about intestinal absorption and cleavage of carotenoids]. / Données récentes sur l'absorption et le catabolisme des caroténoïdes.

Our knowledge about intestinal absorption and cleavage of carotenoids has rapidly grown during the last years. New facts about carotenoid absorption have emerged while some controversies about cleavage are close to end. The knowledge of the absorption and conversion processes is indispensable to understand and interpret the perturbations that can occur in the metabolism of carotenoids and vitamin A. Recently, it has been shown that the absorption of certain carotenoids is not passive - as believed for a long time - but is a facilitated process that requires, at least for lutein, the class B-type 1 scavenger receptor (SR-B1). Various epidemiological and clinical studies have shown wide variations in carotenoid absorption from one subject to another, such differences are now explained by the structure of the concerned carotenoid, by the nature of the food that is absorbed with the carotenoid, by diverse exogenous factors like the intake of medicines or interfering components, by diet factors, by genetic factors, and by the nutritional status of the subject. Recently, the precise mechanism of beta-carotene cleavage by betabeta-carotene 15,15' monooxygenase (EC 1.14.99.36) - formerly called beta-carotene 15,15' dioxygenase (ex EC 1.13.11.21) - has been discovered, and a second enzyme which cleaves asymmetrically the beta-carotene molecule has been found. beta-carotene 15,15' monooxygenase only acts on the 15,15' bond, thus forming two molecules of retinal from one molecule of beta-carotene by central cleavage. Even though the betabeta-carotene 15,15' monooxygenase is much more active on the beta-carotene molecule, a study has shown that it can act on all carotenoids. Searchers now agree that other enzymes that can catalyse an eccentric cleavage of carotenoids probably exist, but under physiological conditions the betabeta-carotene 15,15' monooxygenase is by far the most active, and it is mainly effective in the small bowel mucosa and in the liver. However the conversion of provitamin A carotenoids into vitamin A is only partial, and requires a satisfactory protein status.

Evaluation of a newly available biochemical analyzer: the Olympus AU 600.

The performance of the Olympus AU 600, a newly available open multiparametric analyzer, available for routine biochemical analysis of biological samples, was evaluated. The analytical and technical performance of the apparatus and the quality of the Olympus reagents were both examined in a single site study. Electrolyte concentrations were determined with patented ion-selective electrodes; substrate concentrations and enzyme activities were determined by spectrophotometric measurement after coloured reaction or UV detection-based-reactions. The protocol of the evaluation and the acceptability criteria were those recommended by the French Society for Clinical Biology. For the parameters studied, the upper limits of linearity were equal to or higher than those claimed by the manufacturer. The CV values for within-run and between-run precision were lower than the target values with few exceptions. The comparison study gave satisfactory results for most of the parameters. Only expected interferences occurred. In summary, the results obtained for the 25 parameters studied and the characteristics of the apparatus were satisfactory. The analyzer is rapid (800 to 1200 tests per hour) and easy to use. In addition, the analyzer complies with good analytical practice and its flexibility enables users to plan work according to local laboratory constraints.

Negative regulation of leptin by chronic high-glycemic index starch diet.

The response of plasma leptin to a high-glycemic index (high-GI) starch diet after a short (3 weeks) and prolonged (12 weeks) period was determined in Sprague-Dawley rats. Age-matched rats were fed an identical isocaloric diet except that the carbohydrates were from either mung bean starch (low-GI) or waxy cornstarch (high-GI). After a single test meal of the high-GI starch diet, postprandial plasma glucose (P < .05) and insulin (P < .01) peaks and plasma glucose (P < .014) and insulin (P < .05) areas were higher versus the low-GI starch diet (n = 8 per group). Other age-matched control rats were fed the same diets for a longer period. After 3 weeks, ob mRNA levels were decreased by 50% (P < .005) in the epididymal adipose tissue of high-GI-fed rats versus low-GI-fed rats, without a significant decrease in plasma leptin. After 12 weeks of the high-GI starch diet, both plasma leptin and ob mRNA were decreased by 34% (P < .005) and 41% (P < .05), respectively, compared with the low-GI diet. Both relative epididymal adipose tissue weight (adjusted per 100 g body weight) and total fat mass, as measured by dual-energy x-ray absorptiometry (DEXA), were unchanged by the high-GI starch diet. Basal nonfasting plasma insulin, glucose, and triglycerides were not altered by the high-GI starch diet, whereas free fatty acids were significantly elevated and associated with a trend (P < .13) for increased plasma free glycerol. Plasma leptin levels were negatively correlated with free fatty acid levels (r = .56, P < .05). Despite low leptin, rats fed on the high-GI diet did not increase their food intake, suggesting increased leptin sensitivity. These findings might precede weight gain and the increase in fat mass. Chronic nutritional factors might alter plasma leptin via several overlapping factors independently of energy intake.

Epithelial tumors of the ovary: CT findings and correlation with US.

One hundred thirty patients with 170 epithelial ovarian tumors were prospectively studied with computed tomography (CT) before surgery. Ultrasound (US) was performed in 108 patients with 138 tumors. At pathologic examination, 78 tumors (46%) were benign, 14 (8%) borderline, and 78 (46%) malignant. CT results were compared with surgical and pathologic findings in all patients. CT enabled detection of 148 of 170 tumors (87%), and US enabled detection of 118 of 138 tumors (86%). Benign serous cystadenomas (n = 42) were correctly characterized with a sensitivity of 69% at CT and 70% at US. Benign mucinous cystadenomas (n = 21) were correctly characterized with a sensitivity of 62% at CT and 50% at US. Malignancy was suggested in nine of 14 patients (64%) with borderline tumors at CT and in five of 14 (36%) at US. The overall accuracy of characterization of benign versus malignant tumors (including borderline tumors) was 94% with CT and 80% with US. In the 108 patients studied with both CT and US, the sensitivity of CT was significantly superior to that of US (P less than .03), whereas there was no significant difference in specificity (P = .125).

Hypophosphatemia induced by mechanical ventilation in patients with chronic obstructive pulmonary disease.

The aim of this study was to assess prospectively the variations of serum phosphorus concentration (P) after onset of mechanical ventilation (MV) in patients with chronic obstructive pulmonary disease (COPD) and acute respiratory acidosis. In 14 COPD patients, we measured P, PaCO2, and pH, immediately before MV (H0), then one hour (H1), 4 (H4), 7 (H7), 12 (H12), and 24 h (H24) after starting MV. P at H0 was in or above the normal range in ten patients and below normal range in four patients. P decreased significantly (p less than .001) after MV at H1, H4, H7, H12, and H24. Hypophosphatemia was present in all patients after MV, but was severe (p less than .3 mmol/L) in only two patients. There was a significant correlation (r = .56 p less than .01) between the decrease of P and the increase of pH after MV. Hypophosphatemia was a constant and early finding after institution of MV in COPD patients and was presumably related to an intracellular shift of P secondary to the correction of respiratory acidosis.

[Vitamin D3 sulfoconjugate distribution and evolution in pregnant or lactating rats]. / Répartition et évolution de la vitamine D3, sulfoconjuguée chez la ratte gestante ou allaitante.

24 hrs after intravenous injection of vitamin D3 35S sulfoconjugate the radioactivity in kidney is about twice as much in pregnant Rats as in lactating Rats. It decreases from 24 to 48 hrs in pregnant but increases in lactating Rats kidneys. Hydrolysis of vitamin 3H D3 sulfate is detected in kidney and liver extracts, the ratio of free vitamin D3 on vitamin D3 sulfate is higher in pregnant than in lactating animals. Mammary glands of lactating Rats contain mainly the unchanged vitamin D3 sulfate which can be hydrolysed by new born suckling pups.