Effect of Opuntia dejecta (Salm-Dyck) flowers in liver of fructose-fed rats: Biochemicals, enzymatic and histological studies.

Phytochemical composition and antioxidant activity of flowers decoction at post-flowering stage (F3D) of Opuntia dejecta were determined. The obtained findings demonstrate that F3D has a marked antioxidant activity in all tested assays. Furthermore, the present study was designed to test the protective activity of F3D against induced Diabetes type 2 (DT2) in male rats. Those metabolic syndromes were induced by a high-fructose diet (HFD) (10% fructose solution) for a period of 20 weeks. F3D was administered orally (100 and 300 mg/kg body weight) daily for the last 4 weeks. Metformin (150 mg/kg body weight) was used as a standard drug and administrated orally for the last 4 weeks. The results showed a significant increase in blood glucose, triglycerides and hepatic markers (ALAT, ASAT and ALK-P) in HFD group. A significant increase in hepatic TBARS and a significant decrease in SOD, CAT and GPX were observed in fructose fed rats compared to control group. Administration of F3D showed a protective effect in biochemical and oxidative stress parameters measured in this study. Also, oral administration of F3D restored the histological architecture of rat liver in comparison with rats fed HFD. In conclusion, F3D attenuated hepatic oxidative stress in fructose-fed rats.

GABAB receptor cell-surface export is controlled by an endoplasmic reticulum gatekeeper.

Endoplasmic reticulum (ER) release and cell-surface export of many G protein-coupled receptors (GPCRs) are tightly regulated. For gamma-aminobutyric acid (GABA)B receptors of GABA, the major mammalian inhibitory neurotransmitter, the ligand-binding GB1 subunit is maintained in the ER by unknown mechanisms in the absence of hetero-dimerization with the GB2 subunit. We report that GB1 retention is regulated by a specific gatekeeper, PRAF2. This ER resident transmembrane protein binds to GB1, preventing its progression in the biosynthetic pathway. GB1 release occurs upon competitive displacement from PRAF2 by GB2. PRAF2 concentration, relative to that of GB1 and GB2, tightly controls cell-surface receptor density and controls GABAB function in neurons. Experimental perturbation of PRAF2 levels in vivo caused marked hyperactivity disorders in mice. These data reveal an unanticipated major impact of specific ER gatekeepers on GPCR function and identify PRAF2 as a new molecular target with therapeutic potential for psychiatric and neurological diseases involving GABAB function.

Recurrence plots for dynamical analysis of non-invasive mechanical ventilation.

Quantifiers were introduced to convert recurrence plots into a statistical analysis of dynamical properties. It is shown that the Shannon entropy, if properly computed, increases as the chaotic regime is developed as expected. Recurrence plots and a new estimator for the Shannon entropy are then used to identify asynchronisms in non-invasive mechanical ventilation. It is thus shown that the phase coherence-easily identified using a Shannon entropy-is relevant in the quality of the mechanical ventilation. In particular, some patients with chronic respiratory diseases or healthy subjects can have a high rate of asynchronisms but a regular breathing rhythm.

Recurrence plots and Shannon entropy for a dynamical analysis of asynchronisms in noninvasive mechanical ventilation.

Recurrence plots were introduced to quantify the recurrence properties of chaotic dynamics. Hereafter, the recurrence quantification analysis was introduced to transform graphical interpretations into statistical analysis. In this spirit, a new definition for the Shannon entropy was recently introduced in order to have a measure correlated with the largest Lyapunov exponent. Recurrence plots and this Shannon entropy are thus used for the analysis of the dynamics underlying patient assisted with a mechanical noninvasive ventilation. The quality of the assistance strongly depends on the quality of the interactions between the patient and his ventilator which are crucial for tolerance and acceptability. Recurrence plots provide a global view of these interactions and the Shannon entropy is shown to be a measure of the rate of asynchronisms as well as the breathing rhythm.

Faecal bacterial mass and energetic losses in healthy humans and patients with a short bowel syndrome.

OBJECTIVE: In addition to non-digested nutrients, human stools contain endogenous substrates, among which bacteria are a major component, whose growth may be stimulated when more dietary nutrients are available for bacterial fermentation, as in patients with malabsorption syndrome. We assessed the energy content and composition of both stools and faecal bacteria in healthy volunteers and patients with a short bowel and colon in continuity (SBC). Our goal was to clarify the magnitude of error introduced by the faecal bacteria in the measurement of the digestibility of ingested energy and nutrients. SUBJECTS AND METHODS: We studied six healthy volunteers and six patients with a SBC under free oral intake. The bacterial mass of stools was isolated. In the bacterial fractions and fresh stools, calorie, fat, nitrogen and short-chain fatty acid contents were determined. The Wilcoxon signed rank or the Mann-Whitney tests were used for comparison. RESULTS: In healthy volunteers and patients with SBC, faecal bacterial mass accounted for 44 and 35% of faecal dry weight, and contained 50 and 34% of total faecal energy. In healthy volunteers, the apparent digestibilities when corrected by bacterial constituents (88-97% according to nutrients) were significantly higher than the apparent non-corrected digestibilities (84-94%). In patients with SBC, the corrected apparent digestibilities (69-89% according to nutrients) were significantly higher than the apparent non-corrected digestibilities (54-83%). CONCLUSION: The error introduced by the faecal bacterial fraction when assessing the extent of nutrient digestibility is small in healthy volunteers; it is more pronounced in patients with SBC, reaching 18% for the digestibility of ingested fat.

Comparison of gastric emptying of a solid and a liquid nutritional rehabilitation food.

OBJECTIVE: To compare gastric emptying of a solid and a liquid nutritional rehabilitation food. DESIGN: Cross-over trial. Eight volunteers took, in random order at least 1 week apart, 2100 kJ of a solid and a liquid nutritional rehabilitation food with added labelled [13C] glycine. SETTING: Research ward for healthy volunteers. SUBJECTS: Eight healthy volunteers. METHODS: Appearance of 13CO2 was monitored in expired gas every 15 min for 240 min after meal intake and compared between solid and liquid meals. Parameters of gastric emptying were then calculated. RESULTS: Gastric half-emptying time was slightly longer for solid meal compared to liquid meal (101+/-6.0 vs 88+/-9.8 min, P=0.24). 13CO2 excretion peaked 138+/-5.3 min after the solid meal compared with 119+/-8.6 min with liquid meal (P=0.06). 13CO2 excretion was higher for the liquid food up to 110 min after the meal but then became higher for the solid food. Analysis of variance for repeated measures of 13CO2 excretion showed a significant interaction term between the type of food and time indicating a delayed elimination of 13CO2 for the solid food (P=0.018). CONCLUSIONS: Attempts to replace liquid nutritional rehabilitation foods by a solid food in malnourished patients should take into account a possible slower gastric emptying. SPONSORSHIP: Supported by a grant from Nutriset (Malaunay, France) and ANVAR (Agence Nationale de la Valorisation de la Recherche, contract no. A9703021P).

Large bilateral adrenal incidentalomas complicating untreated 11B hydroxylase deficiency in the third decade of life. A case report.

The occurrence of bilateral giant adrenal incidentalomas is reported in a 22-year-old man who was evaluated for urinary tract infection. The right gland measured 16 cm, the left one 6 cm at computed tomography. Height was 145 cm, blood pressure 190/100 mm Hg. Testes were not palpable. Laboratory investigations revealed elevated levels of 17 hydroxyprogesterone:>50 ng/ml (n<1,1); 11 desoxycortisol: 919 nmol/l (n<30); testosterone: 19 ng/ml (n<0.7) and ACTH: 1 402 ng/l (n<48). Karyotype was 46 XX. The patient was a female pseudohermaphrodite with congenital adrenal 11 B hydroxylase deficiency. Adrenal masses responded to glucocorticoid therapy with marked reduction of their size after six months. We confirm previous recommendations that patients with adrenal incidentaloma should be checked for congenital adrenal hyperplasia.

Comparison of starch digestibility of a blended food prepared with and without extrusion cooking.

OBJECTIVE: To compare starch digestibility from a maize-soy blended food with and without extrusion cooking. DESIGN: Resistant starch, soluble and insoluble dietary fibres were measured in vitro before and after extrusion. Starch digestibility was assessed in 8 volunteers who took, in a randomised order, a test meal with either 100 g extruded (EF) or non-extruded (NEF) blended flour cooked 15 min at 80 degrees C in 500 ml of water. SETTING: Research ward for healthy volunteers. SUBJECTS: Healthy volunteers. MAIN OUTCOME MEASURES: Starch digestibility was measured by 13C enrichment of breath samples for 8 h. Breath H2 concentration was measured during 12 h to assess bacterial fermentation in the colon. Volunteers reported hunger on a visual scale every hour for 8 h. RESULTS: In vitro resistant starch, soluble and insoluble dietary fibers were higher in NEF than in EF (5.4 vs 1.1, 0.7 vs 0.5, and 13.3 vs 10.4% dw respectively). In vivo, the area under curve (AUC) for 13CO2 excretion during 8 h was not significantly different for NEF and EF (10.3+/-1.3 vs 9.1+/-0.5 mmol/min, respectively). AUC for H2 excretion during 12 h was significantly higher for EF than for NEF (26.9+/-5.6 vs 14.1+/-4.7 mL, P<0.05). AUC for satiety was marginally higher with EF (12.6+/-1.6) than for NEF (10.0+/-2.1) (P=0.06). CONCLUSIONS: Extrusion cooking does not seem to substantially improve blended foods digestibility. Extrusion of high fibre flours may promote carbohydrate fermentation in the colon and increase satiety.

Short-chain fructo-oligosaccharide administration dose-dependently increases fecal bifidobacteria in healthy humans.

Short-chain fructo-oligosaccharides (SC-FOS) are a mixture of oligosaccharides consisting of glucose linked to fructose units (Gfn; n =

Metabolic effects of digestible and partially indigestible cornstarch: a study in the absorptive and postabsorptive periods in healthy humans.

To compare the effects of digestible (pregelatinized) and partially indigestible (retrograded) cornstarches on some metabolic indexes, we studied eight healthy volunteers during two periods separated by 1 wk. In each period, fasting volunteers consumed at 0800 the test meal containing either the digestible or partially indigestible cornstarch; blood and breath were sampled in the absorptive period for 8 h. To study its late effects, the same test meal as that served at 0800 was given again at 2200, and blood and breath were sampled for 3 h in the postabsorptive period the next morning, i.e., 10 h after ingestion of the test meal. In the absorptive period, blood glucose and insulin were significantly higher after ingestion of digestible cornstarch than after partially indigestible cornstarch. In the postabsorptive period concentrations of blood glucose, insulin, and fatty acids were not significantly different, whereas concentrations of blood acetate, breath hydrogen, methane, and 13CO2, and the respiratory quotient and satiety were significantly higher (P < 0.05) and concentrations of blood glycerol significantly lower (P < 0.05) after ingestion of partially indigestible cornstarch than after digestible cornstarch. We conclude that in healthy humans, digestion of partially indigestible cornstarch is slow in the small intestine and its colonic fermentation continues 10-13 h after its ingestion. Compared with pregelatinized cornstarch, the shift in starch digestion induced by retrogradation leads to a reduction in glycemic and insulinemic responses in the absorptive period and in lipolysis in the postabsorptive.

Glucose does not facilitate the absorption of sorbitol perfused in situ in the human small intestine.

Sorbitol is better absorbed in the small intestine when ingested concomitantly with glucose. The aim of this study was to test in situ the effect of glucose on the absorption of sorbitol in the human small intestine, using the perfusion technique. The sorbitol absorption of three test solutions, perfused in a random order, was measured in a 30-cm segment of jejunum in six healthy volunteers (4 males and 2 females). The solutions contained the same concentration of sorbitol (55 mmol/L) and increasing concentrations of D-glucose (0, 55 and 110 mmol/L). Net absorption of water increased as the glucose concentration of the solution increased and differed significantly among the three solutions. Net absorption of glucose was significantly greater for the 110 mmol/L glucose solution than for the 55 mmol/L glucose solution [23.6 +/- 1.8 vs. 11.0 +/- 1.2 mmol/(h x 30 cm), P < 0.01]. Sorbitol absorption in the jejunal segment was 5.2 +/- 1.3, 6.2 +/- 0.5 and 5.8 +/- 0.4 mmol/(h x 30 cm) for the glucose-free solution, the 55 mmol/L glucose solution, and the 110 mmol/L glucose solution, respectively. These values did not differ significantly. These results do not support the hypothesis of a facilitating effect of glucose on sorbitol absorption in the human small intestine.

Effect of colonic fermentation on respiratory gas exchanges measured in the postabsorptive state.

To assess the effect of colonic fermentation on respiratory gas exchanges, six methane-nonproducing healthy volunteers ingested in the postabsorptive state 1 wk apart either 90 mL lactulose syrup containing 60 g lactulose, 4 g lactose, and 7 g galactose or the same solution but without lactulose (control solution). Six patients with short bowel and remnant colon (SBS) also ingested 90 mL lactulose syrup. Carbon dioxide production (VCO2), oxygen consumption (VO2), respiratory quotient (RQ), and hydrogen excreted in breath were measured basally and for 4 h after the ingestion of solutions. In healthy volunteers within 4 h after ingestion of the control solution, VCO2 and the RQ decreased whereas VO2 remained unchanged. In contrast, in healthy volunteers and patients with SBS, VCO2 and the RQ increased after lactulose ingestion, whereas VO2 did not change. The increase in VCO2 appeared to be accounted for mainly by bacterial production of carbon dioxide and was significantly related to breath-hydrogen concentration (r = 0.56, P < 0.02 for healthy subjects; r = 0.59, P < 0.01 for SBS subjects). A breath-hydrogen test should be performed in conjunction with indirect calorimetry to determine whether colonic fermentation is taking place and, if so, to correct appropriately the VCO2 value in calorimetric equations.

Bacterial adaptation in patients with short bowel and colon in continuity.

BACKGROUND & AIMS: Long-term carbohydrate malabsorption in patients with short bowel and colon in continuity (SBC) could result in a more efficient fermentation. The bacterial fermentation capacity in patients with SBC was assessed. METHODS: Eleven fasting patients with SBC ingested 60 g lactulose with 10 g polyethylene glycol. Stool specimens were analyzed. Patients were compared with 8 normal subjects who ingested 60 g lactulose on two occasions, separated by 8 days during which 20 g lactulose was taken twice daily. Moreover, the daily amount of bacteria excreted in stools was measured in 6 patients with SBC and 6 normal subjects. RESULTS: Despite fast transit time, patients fermented more lactulose and hexoses and had a higher activity of beta-galactosidase in stools than nonadapted normal subjects (P < 0.01); these parameters were roughly similar in patients and adapted normal subjects. The fecal output of short-chain fatty acids was significantly lower in patients than in nonadapted normal subjects (P < 0.03). Patients excreted a significantly greater amount of bacteria in stools than normal subjects (P < 0.05). CONCLUSIONS: In patients with SBC, the capacity of bacterial flora to ferment lactulose and fecal bacterial mass is spontaneously increased, suggesting that hyperfermentation may affect other carbohydrates. Moreover, hyperfermentation is associated with efficient removal of extra short-chain fatty acids from fecal water.

Symptomatic response to varying levels of fructo-oligosaccharides consumed occasionally or regularly.

OBJECTIVE: To evaluate in 14 healthy volunteers the gastrointestinal tolerance to an indigestible bulking sweetener containing fructo-oligosaccharides (FOS). DESIGN: In order to mimic their usual pattern of consumption, FOS were ingested throughout the day either occasionally (once a week, first period) or regularly (every day, second period). In the two patterns of consumption, daily sugar doses were increased until diarrhoea and/or a symptom graded 3 (i.e. severe) occurred, or when subjects did not want to ingest more candies. SETTING: Clinical Nutrition Unit, Hôpital Saint-Lazare, Paris. RESULTS: In both periods, the first symptom which occurred was excessive flatus (> 30 g FOS/day): borborygmi and bloating appeared at a higher level (> 40 g/day); lastly, abdominal cramps and diarrhoea occurred at a very much higher level (50 g/day). The volumes of hydrogen excreted in breath in response to the same load of FOS were not different between the two periods. CONCLUSIONS: Chronic consumption of FOS initiated cautiously with subsequent gradual increase did not improve tolerance, nor reduce breath excretion of hydrogen.

Sorbitol absorption in the healthy human small intestine is increased by the concomitant ingestion of glucose or lipids.

OBJECTIVE: To test the effect of the concomitant ingestion of glucose or lipids on sorbitol absorption in the human small intestine using the hydrogen breath test. METHOD: After an overnight fast, on four occasions separated by at least 1 week 14 healthy volunteers randomly ingested 20 g sorbitol alone, 20 g sorbitol and 20 g glucose, 20 g sorbitol and 9 g lipids, and 10 g lactulose. Hydrogen concentration was measured in end-expiratory samples every 10 min for 3 h, and then every 30 min for 5 h. Sorbitol malabsorption was calculated from the ratio of the areas under the curve. RESULTS: The estimated rate of sorbitol malabsorption was 98 +/- 14% (mean +/- SEM) when sorbitol was ingested alone, and was significantly lower when ingested with glucose or lipids (68 +/- 10 and 70 +/- 7%, respectively; P < 0.05). Orocaecal transit times did not differ significantly between the different time periods. CONCLUSION: Sorbitol absorption in the human small intestine is increased by the concomitant ingestion of glucose or lipids.

Gastrointestinal effects and energy value of polydextrose in healthy nonobese men.

We studied seven healthy volunteers before and during acute (PD1) and chronic (PD2) ingestion of 30 g polydextrose (PD)/d. The energy value of PD was assessed after [U-14C]PD was added to the 10-g morning dose of PD during PD1 and at the end of PD2. Thirty-one +/- five percent (mean +/- SD) (PD1) and 29 +/- 4% (PD2) of the dose appeared in breath within 48 h. A small fraction of the ingested radioactivity was recovered in urine (4 +/- 1%) and excreted in flatus (< or = 1%) and in feces as volatile fatty acids (VFAs) (< 1%) and bacteria (3-4%); the remaining radioactivity in stools, 33 +/- 3% (PD1) and 32 +/- 4% (PD2), was assumed to be intact PD. Breath excretion of the label was 49 +/- 5% after intracolonic infusion of [U-14C] acetate. The energy value of PD, calculated by means of Miller and Wolin's stoichiometric equation of colonic fermentation, was similar during PD1 and PD2: 4.0 and 6.1 kJ/g, respectively, when breath 14CO2 and VFA production from PD were used for calculation.

Fate of beta-cyclodextrin in the human intestine.

We assessed the fate of beta-cyclodextrin, which is composed of seven alpha(1-->4)-linked glucose units in ring structure, in the human gastrointestinal tract. In four healthy ileostomists, ileal effluent was collected after oral administration of beta-cyclodextrin during fasting (10 g of beta-cyclodextrin) and postprandially (10 g of beta-cyclodextrin three times daily with meals). In 10 healthy volunteers, the amount of beta-cyclodextrin passing into the colon was determined by means of the breath hydrogen technique using lactulose as a standard, and stools were collected after oral administration of beta-cyclodextrin during fasting (10 g of beta-cyclodextrin) and postprandially (10 g of beta-cyclodextrin three times daily with meals). In ileostomists, we recovered from the small intestine 91 +/- 5% and 97 +/- 10% (mean +/- SD) of beta-cyclodextrin ingested during fasting and with meals, respectively. In healthy volunteers, H2 excretion in breath after beta-cyclodextrin ingestion was low compared with excretion after lactulose, but only traces of beta-cyclodextrin were recovered in stools. We conclude that beta-cyclodextrin is poorly hydrolyzed in the human small intestine but that it is fermented by the colonic flora with apparent minimal H2 production.

[Clinical tolerance, intestinal absorption, and energy value of four sugar alcohols taken on an empty stomach]. / Tolérance clinique, absorption intestinale et valeur énergétique de quatre polyols pris à jeun.

Sugar alcohols are incompletely digested in the human small intestine. The residual amounts reaching the colon are digested by colonic bacteria or excreted in stools. Clinical tolerance and energy value of sugar alcohols are related to their respective rates of digestion in the small intestine and the colon. Six healthy volunteers were tested in 5 periods during which they ingested 10 g lactulose, and then, in a random order, an iso-osmotic solution of 20 g isomalt, sorbitol, maltitol, and lactitol. The fraction of sugar alcohols absorbed in the small intestine was evaluated by comparing the amounts of hydrogen excreted in breath for 8 h after the ingestion of lactulose and of sugar alcohols. Energy value of sugar alcohols was determined knowing the amounts absorbed in the small intestine and digested in the colon. Tolerance to the sugar alcohols was good in all volunteers, and not different between sugar alcohols. The mean percentage of malabsorption in the small intestine was significantly higher for lactitol (84 +/- 14 percent, m +/- SEM) than for maltitol and isomalt (44 +/- 7 and 40 +/- 7 percent), its energy value (2.3 +/- 0.3 kcal/g) was significantly lower than the energy value of maltitol (3.1 +/- 0.1 kcal/g, P less than 0.05); whereas those of sorbitol and isomalt were close (2.7 +/- 0.2 and 2.8 +/- 0.1 kcal/g, respectively). In spite of these differences, our results suggest that in our experimental conditions, bacterial digestion of the sugar alcohols reaching the colon was complete, and did not affect their clinical tolerance.

[Hemolytic-uremic syndrome in adults]. / Le syndrome hémolytique et urémique de l'adulte.

Haemolytic uraemic syndrome is a rare condition easily diagnosed from biochemical data. Numerous forms consecutive to pregnancy, systemic diseases, carcinomas (notably mucin-secreting gastric adenocarcinoma), infections and medications have been described. The physiopathology of the syndrome, although more elaborate, is not entirely clear. The fundamental anatomical lesions (fibrin-platelet microthrombi) develop from vascular endothelial injuries. They persist and extend due to the non-functioning of physiological regulatory systems, in particular the coagulation-fibrinolysis system. In spite of frequently heavy and expensive treatments empirically applied, the course of the disease is generally unfavourable, with a mortality of about 50%.