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D Tome

Publications and source records attributed to D Tome.

At least 19 recordsLinked to original sources
PubMed2006

Commercial Phaseolus vulgaris extract (starch stopper) increases ileal endogenous amino acid and crude protein losses in the growing rat.

The effect of a commercial Phaseolus vulgaris extract (PVE, starch stopper) on ileal and fecal endogenous protein losses was studied. Growing rats were fed for 14 days a protein-free diet containing PVE at a nutritional concentration of 0% (PF1), 0.4% (PF2), or 1.1% PVE (PF3) or 1.1% autoclaved PVE (PF4). An indigestible marker (TiO(2)) was included in each diet. Ileal endogenous amino acid (AA) losses were significantly higher (P < 0.05) in PF3 (20% higher than in PF1), except for Pro, Gly, Ala, and His. Endogenous ileal N losses were 22% higher in PF3 than in PF1. Endogenous fecal AA and N losses were all significantly higher (P < 0.05) in PF3. Starch digestibility ( approximately 100%), food intake (single daily meal, d10-23), and body weight loss were not significantly different among the groups. PVE, at 1.1% of the diet, not only was ineffective in reducing starch digestibility but also led to increased ileal endogenous N losses, possibly due to the antinutritional factors (trypsin inhibitor, lectin) present in the PVE.

Amino Acids↗
PubMed2001

Transport of proanthocyanidin dimer, trimer, and polymer across monolayers of human intestinal epithelial Caco-2 cells.

The gut absorption of proanthocyanidins (PAs) and of the related (+)-catechin monomer was investigated with colonic carcinoma (Caco-2) cells of a human origin, grown in monolayers on permeable filters. Permeability of various radiolabeled PAs differing in their molecular weight was compared with that of the radiolabeled (+)-catechin. No toxicity was observed at PA concentrations up to the physiological concentration of 1 mM. (+)-Catechin and PA dimer and trimer had similar permeability coefficients (P(app) = 0.9-2.0 x 10(-6) cm s(-1)) close to that of mannitol, a marker of paracellular transport. Paracellular transport was also indicated by the increase of absorption after reduction of the transepithelial electric resistance through calcium ion removal. In contrast, permeability of a PA polymer with an average polymerization degree of 6 (molecular weight 1,740) was approximately 10 times lower (P(app) = 0.10 +/- 0.04 x 10(-6) cm s(-1)). PAs, particularly the most astringent PA polymer, were also adsorbed on the epithelial cells. These results suggest that PA dimers and trimers could be absorbed in vivo and that polymer bioavailability is limited to the gut lumen.

Anthocyanins↗
PubMed2000

The nutritional intake of a free-living healthy French population : a four-year follow-up.

OBJECTIVE: To contribute to a better definition of the nutritional requirements of the healthy elderly and to improved knowledge the effects of age on these requirements. METHODS: We studied the nutritional intake of 96 elderly persons who had met criteria of good health status in 1993 at a four-year interval. The nutritional intake of the elderly subjects who remained healthy during the four-year interval (18 men and 64 women), was considered to globally correspond to their nutritional needs. The nutritional intake was evaluated by a three-day food record. RESULTS: The mean baseline weight of the subjects who remained in good health during the four years was 72,6 +/- 9,5 kg for men and 60,1 +/- 9,3 kg for women. In four years, mean weight remained globally stable. But in cross-sectional analysis, weight tended to decrease with the age of the subjects. This decrease was significant for women in 1993. Mean baseline intake was nearly 29 kcal/kg. Longitudinal and cross-sectional analyses showed that it changed only slightly with age. Though global energy intake varied slighlty in four years, we have observed some changes in the composition of this caloric intake. For men and women, protein intake tended to decrease in four years (respectively -0,4% and -0,6%), carbohydrate intake to decrease (respectively -1,1% and -2,7%) and fat intake to increase (respectively +2,1% and +2,9%). These variations were not significant except for fat and carbohydrate intakes in women. In 1993, for a majority of subjects, the intakes of iron, and vitamins C and B12 were higher and the intakes of calcium, zinc, vitamins A, B1, B6 and B9 were lower than the French recommendations. In four years, mean intake did not change significantly, except for calcium intake in women (-8,8%). CONCLUSION: In this study, healthy aging was associated with a mean caloric intake close to 29 kcal/kg which is near the upper limits of recommendations (between 25 and 30 kcal/kg/d). These intakes, like those of macronutrients and micronutrients changed little with advancing age. These results suggest that the needs of the elderly remain quite stable with aging. Nevertheless a tendency to weight loss with aging is observed, especially in older subjects, suggesting that even if food intake contributes to the maintenance of healthy aging, aging processes are multidimensional and frailty that is often associated with weight loss is ineluctable for older subjects.

Aged↗
PubMed1999

Rapid fall in plasma threonine followed by increased intermeal interval in response to first ingestion of a threonine-devoid diet in rats.

In most animals, ingestion of a diet lacking an essential amino acid (EAA) gives rise to anorexia within a few hours. The first signal in this feeding response may be the fall in plasma levels of the limiting EAA. In the present study, we measured plasma amino acid levels and food intake after the first exposure to either a threonine-devoid (THR-DEV) or corrected (COR) diet in 16 rats bearing a chronic jugular catheter for blood sampling. Food intake was reduced 165 min (p<0.05) after presentation of the THR-DEV diet. Analysis of the feeding pattern showed that intake was reduced via a four-fold lengthening of the second inter-meal interval. Plasma threonine levels started to fall between 30 and 60 min after onset of the meal (p<0.05). These results, observed in the same rats, lend further support for an early modification of the plasma amino acid pattern in relation to the decrease in feeding of a diet that is EAA deficient.

Analysis of Variance↗
PubMed1996

Tribal-based cancer control activities. Services and perceptions.

BACKGROUND: Cancer is becoming a significant health problem for American Indians and Alaska Natives. Despite the precipitous increase in cancer rates in these populations, limited data are available regarding the extent of cancer control services available in these communities. METHODS: A cross-sectional survey of tribal health directors of all federally recognized tribes was undertaken to discover the breadth of cancer control activities offered and directors' perceptions of and priorities ascribed to cancer. RESULTS: Little more than half (53%) of respondents perceived cancer rates to be increasing. Cancer was found to rank fifth among seven health conditions when directors were asked to rank their tribe's commitment to confronting each. Lower relative levels of awareness of cancer patterns coupled with competing health problems relegated cancer control activities to low-priority issues. CONCLUSIONS: Findings from this study underscore the need to elevate the issue of cancer in Indian Country and to educate investigators to become more sensitive and responsive to other tribal health issues.

Alaska↗
PubMed1995

Exogenous and endogenous nitrogen flow rates and level of protein hydrolysis in the human jejunum after [15N]milk and [15N]yoghurt ingestion.

Milk and yoghurt proteins were 15N-labelled in order to measure the flow rate of exogenous N during digestion in the human intestine. After fasting overnight, sixteen healthy volunteers, each with a naso-jejunal tube, ingested either [15N]milk (n 7) or [15N]yoghurt (n 9). Jejunal samples were collected every 20 min for 4 h. A significant stimulation of endogenous N secretion was observed during the 20-60 min period after yoghurt ingestion and the 20-40 min period after milk ingestion. The endogenous N flows over a 4 h period did not differ between the groups (44.3(SEM 6.5) mmol for milk and 63.5(SEM 5.9) mmol for yoghurt). The flow rates of exogenous N indicated a delayed gastric emptying of the yoghurt N compared with N from milk. The jejunal non-protein N (NPN) flow rate increased significantly after milk and yoghurt ingestion due to an increase in the exogenous NPN flow rate. The NPN fraction of exogenous N ranged between 40 and 80%. The net gastro-jejunal absorption of exogenous N did not differ significantly between milk (56.7(SEM 8.5)%) and yoghurt (50.9(SEM 7)%). The high level of exogenous N hydrolysis is in accordance with the good digestibility of milk products. Fermentation modifies only the gastric emptying rate of N and does not affect the level of diet hydrolysis, the endogenous N stimulation or the digestibility rate.

Adult↗
PubMed1995

Evaluation of capnography in nonintubated emergency department patients with respiratory distress.

OBJECTIVE: To evaluate the ability of noninvasive capnographic measurement of end-tidal CO2 tension (PetCO2) to predict arterial CO2 tension (PaCO2) in nonintubated ED patients with respiratory distress. METHODS: A prospective, nonblind study was performed in a level I trauma center/community teaching hospital ED. Participants included all nonintubated adult patients with respiratory distress requiring measurement of arterial blood gases (ABGs); 29 patients were enrolled. PetCO2 was measured with a capnography monitor, using both baseline tidal volumes and forced expiratory volumes. The bias between PetCO2 values and simultaneous measurements of PaCO2 by ABG was assessed. RESULTS: PetCO2, measured with forced expiration, and PaCO2 agreed well, with bias (i.e., average difference) = 0.44 +/- 0.52 kPa (3.3 +/- 3.9 torr). PetCO2 measured with the tidal volume breath produced an unacceptably high bias of 0.82 +/- 0.70 kPa (6.1 +/- 5.2 torr). Levels of agreement between PaCO2 were similar for smokers and nonsmokers and for men and women. The arterial-end-tidal CO2 tension (Pa-etCO2) difference was not related to PaCO2. Pa-etCO2 correlated with age (r = 0.473; p = 0.01), and was significantly higher in patients with pulmonary disease (1.32 +/- 0.56 kPa; 9.9 +/- 4.2 torr) than it was in those without pulmonary disease (0.46 +/- 0.55 kPa; 3.5 +/- 4.1 torr; p < 0.001). CONCLUSIONS: Noninvasive PetCO2 monitoring may adequately predict PaCO2 in nonintubated ED patients with respiratory distress who are able to produce a forced expiration. PetCO2 is less accurate for PaCO2 with tidal volume breathing and in patients with pulmonary disease.

Adult↗
PubMed1994

Gastro-jejunal digestion of soya-bean-milk protein in humans.

In order to determine how soya-bean proteins are digested and metabolized in the human intestine before colonic bacterial fermentation and to estimate their true digestibility, the gastro-jejunal behaviour of soya-bean proteins in water and in two other forms (a concentrated soya-bean-protein solution (isolate) and a drink composed of crude soya-bean proteins (soymilk)) was studied in humans. Experiments were carried out in eight healthy volunteers using a double-lumen steady-state intestinal perfusion method with polyethyleneglycol (PEG) as a non-absorbable volume marker. Gastric emptying and N and electrolyte contents of the jejunal digesta were analysed. Gastric half-emptying time (min) of the liquid phase after water ingestion (12.59 (SE 0.12)) was shorter (P < 0.05) than those for soymilk (37.74 (SE 11.57)) and isolate (36.52 (SE 11.23)). Electrolytic balances showed that for all meals, Na+, Cl- and K+ were secreted when Ca2+ was efficiently absorbed from the jejunal lumen. Gastro-jejunal N absorption for isolate and soymilk were 63 and 49% respectively, and were not significantly different from one another; after water ingestion, endogenous N was estimated to be 21 mmol. An estimate of the exogenous:endogenous values for the effluents was obtained from the amino acid compositions of soymilk and effluents after water or soymilk ingestion, indicating that 70% of the total N was exogenous and 30% endogenous. Under these conditions the endogenous fraction represented 31 mmol after soymilk ingestion and the gastro-jejunal N balance indicated that 54% of the soymilk was absorbed. This finding indicates that the true gastrojejunal digestibility of soya-bean proteins is similar to that of milk proteins.

Adult↗
PubMed1992

Transport of putrescine in the isolated rabbit intestine.

The transepithelial fluxes of putrescine were studied in sections of the three segments of rabbit intestine mounted in an Ussing chamber. The ileum exhibited the highest mucosal-to-serosal (Jms) and serosal-to-mucosal (Jsm) unidirectional fluxes of 1 mumol/l [3H]putrescine. Putrescine net flux (Jnet = Jms - Jsm) was deduced to be positive through the duodenum (Jnet = 53.40 +/- 14.30 pmol h-1 cm-2), not significantly different from zero through the jejunum (Jnet = 8.90 +/- 19.20 pmol h-1 cm-2) and negative through the ileum (Jnet = -34.30 +/- 13.80 pmol h-1 cm-2). Increasing putrescine concentration up to 10 mmol/l led to an increase in Jms, Jsm and Jnet without affecting the transport polarity in the ileum. The tissue retention of putrescine after 100 min was higher by the serosal side than by the mucosal side of the ileum. In parallel experiments, isolated pieces of ileum accumulated putrescine to a five- to sixfold concentration gradient by a ouabain-inhibitable mechanism. In contrast with arginine and in order of decreasing potency, putrescine, cystamine (a transglutaminase inhibitor), spermidine and spermine (1 mmol/l) reduced both unidirectional fluxes of putrescine across the ileum in the Ussing chamber. The latter effectors, except spermine, and N,N-dimethylcasein (1 mg/ml) led to an important, if not complete, suppression of putrescine secretion by the ileum, while the calmodulin antagonist melittin (0.3 micrograms/ml) reversed the polarity of polyamine transport, suggesting the involvement of transglutaminase in putrescine transport. We conclude that the heterogeneous pattern of putrescine transport along the small-intestinal epithelium constitutes an important feature of the regulation of polyamine concentrations in this tissue.

Animals↗
PubMed1991

In vitro effects of tetrodotoxin and hexamethonium on electrolyte transport in rabbit ileum treated with cholera toxin.

To determine if there was a role for the submucosal nerves in cholera toxin (CT)-induced secretion, we studied the effects of serosal addition of two neurotoxins, the nerve conduction blocking agent, tetrodotoxin (TTX), and the nicotinic ganglionic blocking agent, hexamethonium (HXM), on electrolyte secretion in control isolated rabbit ileum and in that stimulated by CT. 1). In the absence of CT, the short circuit current (Isc) decreased after TTX (10(-7) M) (P less than 0.01) and was unaltered by HXM (10(-5) M). In the presence of CT, Isc increased but was not modified by 10(-7) M TTX or 10(-5) M HXM. 2) In control tissues the mean isotopic Na+ and Cl- fluxes were not significantly altered by TTX addition. Cl- absorption alone was significantly reduced by HXM (delta JCl- = 1.95 +/- 0.81 microEq.hr-1.cm-2; P less than 0.02). After stimulation with CT, TTX significantly inhibited Na+ and Cl- secretion (delta JNa+ = 2.15 +/- 0.61 and delta JCl- = 2.15 +/- 0.76 microEq.hr-1.cm-2; P less than 0.01). Similarly, HXM significantly inhibited CT-stimulated Na+ and Cl- secretion (delta JNa+ = 1.73 +/- 0.70 and delta JCl- = 1.46 +/- 0.62 microEq.hr-1.cm-2; P less than 0.02). 3) In TTX and HXM treated tissues there was no difference in the increase in Isc caused by cAMP (2 x 10(-3) M), calcium ionophore A 23187 (4 x 10(-6) M) and glucose (10(-3) M) compared to the untreated tissues in the presence or absence of CT.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Transmucosal transport of phytohemagglutinin, concanavalin A and alpha-lactalbumin across rabbit ileum in vitro.

The transmucosal passage of alpha-lactalbumin (alpha-La), phytohemagglutinin (PHA), and concanavalin A (Con A) (1 mg/ml) was measured in the rabbit ileum mounted in the Ussing chamber, with and without 10(-2) M glucose or galactose. The transport of the radiolabelled proteins was assessed by radioisotopic determination, high pressure liquid chromatography (HPLC) and enzyme linked immunosorbent assay (ELISA). In the absence of galactose, the transmucosal transport was significantly higher for PHA (4.1 +/- 1.8 micrograms/h.cm2 mean +/- SE) than for alpha-La (2.9 +/- 1.2) and very low for Con A (0.6 +/- 0.5). HPLC analysis of the transported material revealed differential processing of the proteins. ELISA indicated that 3 percent of radiolabelled alpha-La that crossed the epithelium was in an immunoreactive form, whereas no immunoreactive forms of PHA and Con A were detected. The uptake or binding by the tissue was identical for PHA and Con A (7.8 +/- 2.9 and 5.8 +/- 2.8 micrograms/cm2, respectively), and significantly lower for alpha-La (1.5 +/- 0.31). 10(-2) M galactose did not modify the uptake or binding of alpha-La and Con A, but significantly decreased that of PHA to a level that was not significantly different from that of alpha-La. The present results indicate that the initial uptake of the proteins is most likely dependent upon their interactions with the luminal side of the epithelium. After uptake, the proteins are subjected to intracellular processing which also appeared differential. Thus, protein transport depends on the properties both of the compartment crossed (Glycocalyx, brush-border membrane, cytoplasm, basolateral membrane), and of the protein.

Animals↗
PubMed1989

Histamine content, diamine oxydase and histidine decarboxylase activities along the intestinal tract of the rat.

Histamine is widely distributed in the intestine where it is involved in many pathological reactions. The relations between histamine content, diamine oxidase and histidine decarboxylase activity have been investigated along rat's intestine. Results showed significant variations along the intestine. A correlation was observed between histamine and histidine decarboxylase (p less than 0.01), both of them being even in the small intestine (11.8 +/- 2.3 ng/mg ww and 112.5 +/- 21.2 fmoles/hr/mg ww respectively), significantly higher in the caecum (16.3 +/- 1.9 and 178 +/- 20.1) and significantly smaller in the colon (7.3 +/- 1.1 and 65.3 +/- 11.5) than in other intestinal segments. Diamine oxydase activity was higher in ileum (30.7 +/- 7.2 pmoles/min/mg ww) than in jejunum (17.1 +/- 2.8), caecum (4.3 +/- 0.8) and colon (2.6 +/- 2.7), and could not be linked to histamine content. The results fitted in the hypothesis that histamine in rat intestine is mainly located in mast cells where HDC is probably the main enzyme involved in its modulation.

Amine Oxidase (Copper-Containing)↗
PubMed1989

Transport of beta-lactoglobulin across rabbit ileum in vitro.

Intestinal transepithelial transport constitutes a major limiting step in the transfer of food protein antigens to the blood. This transport was studied in isolated rabbit ileum in Ussing chamber in vitro for the milk protein antigen beta-lactoglobulin (beta-Lg). The transepithelial passage of beta-Lg was measured by enzyme-linked immunosorbent assay (ELISA) and radiolabeled protein transfer and compared with that of the nonmetabolizable marker polyethylene glycol (PEG)-4000. When 1 mg/ml of beta-[14C]Lg or [3H]PEG was added to the mucosal side of the tissue, the total uptake, measured as the transfer of radiolabeled material across the ileum, was significantly higher for beta-Lg than for PEG (5.46 +/- 1.75 vs. 1.43 +/- 0.26 micrograms.h-1.cm-2). Measured by ELISA, 6-9% of the total amount of beta-Lg transported was absorbed in an intact antigenic form. This transport of intact beta-Lg was inhibited by the metabolic inhibitors 50 mM 2-deoxyglucose and 1 mM azide added simultaneously, was reduced by the microtubule assembly inhibitor 0.05 mM colchicine, and was enhanced by 20 mM ammonia, which inhibits lysosomal proteolytic activity. These results indicate that beta-Lg is efficiently absorbed by the intestinal mucosa of adult animals, partly in intact antigenic form and that beta-Lg transport is probably transcellular, as observed for other proteins. The finding that beta-Lg is absorbed in intact antigenic form agrees with other reports implying that beta-Lg is the main factor responsible for milk protein immunoreactivity and intolerance.

Ammonia↗
PubMed1989

Antigen absorption in bacterial diarrhea: in vivo intestinal transport of beta-lactoglobulin in rabbits infected with the entero-adherent Escherichia coli strain RDEC-1.

We studied the absorption of both antigenic and degraded beta-lactoglobulin (beta-LG) from the ileum to the portal blood, in rabbits infected at weaning with the entero-adherent Escherichia coli strain RDEC-1. The infection was characterized by high bacterial excretion from days 7 to 18 postinfection (pi), acute diarrhea for 10 days, and considerable growth retardation. Intestinal absorption of beta-LG was measured at four stages of the infection: early (day 3 pi), peak (day 10 pi), late (day 18 pi), and recovery (day 30 pi). During the 30-day period of infection, age-matched control rabbits exhibited a significant decrease in antigenic and degraded beta-LG absorption. In both control and infected animals, more than 90% of the beta-LG was absorbed by a degrading pathway and the remainder in antigenic form by a minor pathway. RDEC-1 infection significantly raised antigenic beta-LG absorption from days 10 to 30 pi, which delayed the decrease that normally occurs with age. Degraded beta-LG absorption was not modified by the infection, except for a slight increase observed at the recovery stage (day 30 pi). These results suggest that RDEC-1 diarrhea increases absorption of food antigens. The subsequent local or systemic immune responses are not known, but pathologic consequences are possible in susceptible individuals.

Animals↗
PubMed1987

Opiate activity and transepithelial passage of intact beta-casomorphins in rabbit ileum.

The functional significance of the presence of opioid peptides in enzymatic digestion of food proteins remains uncertain. The effect of natural beta-casomorphins (beta-CMs), beta-CM-5 and beta-CM-4-NH2 (morphiceptine), and the analogue beta-[D-Ala2,4,Tyr5]CM-5-NH2 were studied in isolated rabbit ileum mounted in Ussing chambers. All three peptides caused a naloxone-reversible reduction in short-circuit current (Isc) after addition at a concentration of 10(-4) M to the serosal side of the tissue. After addition to the mucosal side, only the analogue beta-[D-Ala2,4,Tyr5]CM-5-NH2 reduced Isc. Natural beta-CMs were degraded by the intestinal mucosa, and no intact transepithelial passage was detected for these peptides, whereas beta-[D-Ala2,4,Tyr5]CM-5-NH2 was demonstrated to cross the epithelium intact when added at a concentration of 10(-3) M in the mucosal reservoir (mucosal-to-serosal flux = 3.5 +/- 1.2 nmol.h-1.cm-2). These results show that both natural beta-CMs and the protected analogue have an opiate activity on intestinal electrolyte transport. Their action from the luminal side of the intestine seems to depend on the transfer of the intact peptides from the luminal to the blood side of the tissue where opiate receptors are located. This action is prevented by luminal hydrolysis of the natural peptides.

Animals↗
PubMed1984

Anticholeraic effect of methylated casein in rat jejunum.

To explore the antisecretory effect of methylated casein (MC) cholera toxin was placed in isolated jejunal loops, and in vivo water fluxes were measured 3 h later in the presence or absence of MC. Secretion was observed in the loops filled with Ringer's solution only, but net absorption was observed in all 10 loops to which MC was added. Its actions was evident within 20 min, and was exerted directly on the luminal side of the epithelium. This response was dose-dependent and the antisecretory effect vanished after boiling MC and after ultrafiltration. In vitro, the antisecretory effect of MC consisted of reversing net Na and Cl fluxes from secretion to absorption (delta JNanet = 6.18 +/- 1.25 and delta JClnet = 5.10 +/- 1.66 microEq . h-1 . cm-2). This change was due to the enhancement of mucosal to serosal flux. Transepithelial potential difference and tissue conductance did not alter. Interestingly, MC did not interfere with intestinal function in the absence of stimulation by cholera toxin. In the presence of cholera toxin, MC and glucose both stimulated ionic absorption by different mechanisms, MC stimulating neutral NaCl absorption, and glucose stimulating electrogenic Na absorption. MC did not alter basal adenylate cyclase activity but it inhibited the cholera toxin-stimulated increase in activity. The present results indicate that methylated casein inhibits water and electrolyte secretion induced by cholera toxin in rat jejunum. Its availability, low cost, and curative effect from the luminal side constitute compelling indications for further investigation.

Adenylyl Cyclases↗
PubMed1981

Carbon 13 nuclear magnetic resonance studies on formaldehyde reactions with polyfunctional amino-acids.

Addition and condensation reactions of formaldehyde with polyfunctional amino-acids and their N alpha-acetyl derivatives have been studied in neutral or mildly acid solutions using 13 C n.m.r. The first addition reaction, giving hydroxymethyls, is fast and incomplete with the amine, guanidyl, hydroxyl, indole and imidazole groups of the side chains, fast and complete with the sulfhydryl group, slow and complete with the amide group. For asparagine, threonine, histidine and tryptophan, the N alpha-hydroxymethyl condenses with the basic group of the side chain to give a cyclic compound. In the case of cysteine, it is the S-hydroxymethyl which condenses with the alpha-amino group. The value of the chemical shifts of the hydroxymethyls and of the methylene bondings will be of help in the study of the reactions of formaldehyde with proteins.

Amides↗