[Dietary intake in the urban and rural populations of the Cap-Bon]. / Apports alimentaires dans la population urbaine et rurale du Cap-Bon.

BACKGROUND: An assessment of nutriment intake (protein, carbohydrates, fat) was collected from a baseline survey of risk factors for cardiovascular diseases from the urban and rural population of the North East of Tunisia (Cap-Bon). METHODS: 692 men and women, 35-50-year-old, were examined. The sample was randomly selected on the basis of the 1984 census from the population of Cap-Bon. A standardized 24-hour recall and a semi-quantitative food frequency questionnaire were used. RESULTS: The amount of food consumed differed between men and women (expressed in absolute value), but no significant difference was shown between men and women when food intake was expressed in relative value (contribution to total energy intake). The living area (urban, rural) appears to be an important factor influencing nutritional intake. CONCLUSION: In the urban population, the increase of protein and fat intake (saturated fat and dietary cholesterol) and the decrease of carbohydrates and fiber intake schematize the trend of dietary habits in Tunisia.

The role of sodium in the in vivo absorption of glycine by the intestine of the amphibian discoglossus pictus.

This work showed that sodium deficit in the incubation medium causes a decrease in oxygen consumption of the isolated intestine. Replacement of 33% and 66% sodium by equivalent quantities of potassium provoked respective inhibitions of 43.5% and 44%. Total replacement of sodium induced an inhibition of 51.7%. Under in vivo conditions, sodium deficit in the luminal fluid led to lower glycine absorption. This inhibition was 7.9% in 5/1000 NaCl, from 16.8% in 2.5/1000 NaCl and 27.4% when sodium was totally replaced by potassium. The quantity of glycine retained by the intestinal wall in vivo was inversely proportional to sodium concentration in the intestine. We conclude from the latter result that the presence of sodium in the lumen appears to stimulate glycine transport across the basolateral membrane of the intestine.

Regional variations in electrical and ion transport properties along the isolated intestine of the frog Rana esculenta.

Anterior, posterior and colon regions of isolated intestines of the frog Rana esculenta were studied in Ussing chambers under short-circuit conditions. Each region presented a serosa-positive potential which decreased upon longer incubation with no significant change in resistance. The colon displayed higher transepithelial potential (initial mean: 11.4 mV) and resistance (165.cm 2) than the proximal parts (initial mean: ca. 2 mV and 120-80 .cm 2). Bilateral substitution of Na+ by NMDG (N-methyl-D-glutamine) or of Cl- by gluconate induced large and sustained decreases in potential and current, which were reversed in the anterior and posterior intestine and abolished in colon, indicating strict dependence upon the presence of both Na+ and Cl-. The mucosal membranes showed the presence of amiloride-sensitive Na+ sites (with drug efficiency higher in colon). Na+/K+/2Cl- cotransport (current decreased by about 50% by bumetanide in anterior and posterior regions only), Cl- permeability or channels inhibited by diphenylamine-2-carboxylate, DPC (similar decreases as by bumetanide). In either chamber 5 mM BaCl2 induced 20-42% inhibition of current, indicating the occurrence of barium-sensitive K+ channels in both apical and basolateral membranes (more markedly on serosal side) in all three intestinal regions. Finally, current increase by IBMX and theophylline designate the colon as a target for adenylate cyclase stimulating hormones.

Effect of tea decoction given to rats ad libitum for a relatively long time on body weight gains and iron, copper, zinc, magnesium concentrations in blood, liver, duodenum and spleen.

The aim of our study was to examine the influence of tea decoction given ad libitum for 15 days on body weight gains and on nonheme iron, copper, zinc and magnesium concentrations in the blood from a semisynthetic diet provided to healthy rats. We have also evaluated the reserves of these essential minerals in the liver, duodenum and spleen. Our findings indicate that the tea decoction significantly reduced the total body weight growth in the tea group as compared to the control group (p < 0.0001). The total body weight gains for the control and tea groups were 13.2 and 2.4%, respectively. On the other hand, our data show that the tea decoction significantly reduced nonheme iron concentration in the total blood by 31.8% (p < 0.001). Similarly, the reserve of iron stored in the liver and the duodenum declined more significantly by 57% (p < 1.10(-7) and 50.5% (p < 1.10(-6)). respectively. In contrast to the inhibitory effect on iron concentration and its stored reserve, tea decoction significantly increased zinc, copper and magnesium concentrations in the total blood. Zinc, copper and magnesium concentrations increased by 29.4 (p < 0.05), 69.0 (p < 0.001) and 48.7% (p < 0.001), respectively. Moreover, tea decoction treatment did not raise the reserve of zinc or copper significantly but it increased the reserve of magnesium stored in the liver (p < 0.05).

[Level of cardiovascular risk factors in the urban and rural populations of Cap-Bon: Tunisia]. / Niveau des facteurs de risque cardio-vasculaire dans la population urbaine et rurale du Cap-Bon: Tunisie.

Cardiovascular risk factors were studied in a random sample from the urban and rural population of the Cap-Bon, including 692 men and women, aged 35-50 years. In this sample, including 56 % urban dwellers, the mean total cholesterol was higher in urban areas (4.64 mmol/l) than in rural areas (4.16 mmol/l). In urban areas 10.2 % of the subjects had values above 6.2 mmol/l compared with 6.6 % in rural areas. Obesity was much more frequent among women (35.2 % versus 26.3 %) but less frequent among men (16.0 % versus 5.4 %) in urban and rural areas. Diabetes was found in 8.8 % of men and 10.4 % of women in urban areas, and only 0.8 % and 3.9 % in rural areas. Hypertension was found in 13.8 % of women and 11.6 % of men in urban areas, 13.3 % and 4.0 % in rural areas (13.3 %). Cigarette smoking was found in 60.7 % of men in urban areas and 75.8 % in rural areas (p < 0.05).

Effect of different levels of an ascorbic acid and tea mixture on nonheme iron absorption from a typical Tunisian meal fed to healthy rats.

The aim of our study was to evaluate the bioavailability of iron from a typical Tunisian meal 'couscous' provided to healthy rats with or without appropriate mixtures of tea plus ascorbic acid and to search for the optimal amount of ascorbic acid able to overcome the inhibitory effect of tea prepared under realistic Tunisian circumstances. Our findings show that a tea decoction (100 mg/ml) reduced nonheme iron absorption from couscous by 50% (16.5 vs. 33.1%; p < 0.01). In contrast, administration of 20 mg ascorbic acid increased nonheme iron absorption from couscous by more than 100% (66.8 vs. 33.1%; p < 0.001). Administration of ascorbic acid (20 mg) in a tea decoction (100 mg/ml) completely counteracted the inhibiting effect of tea and significantly improved the nonheme iron absorption from couscous (34 vs. 33% in the control group; NS). The same effect was shown when 10 mg ascorbic acid was added to the tea decoction; however, 5 mg ascorbic acid was not able to overcome the inhibitory effect of tea on nonheme iron absorption from couscous (33.1 vs. 19.4%; p < 0.01). Our findings demonstrate that a molar ratio of ascorbic acid and tea equal or superior to 0.25 or 0.50 is necessary to overcome the inhibitory effect in rats of tea prepared under Tunisian circumstances. In relation to human nutrition, for Tunisians who regularly drink tea, we suggest a much greater amount of ascorbic acid than that normally recommended for normal subjects.

Relationship between semen characteristics, alpha-glucosidase and the capacity of spermatozoa to bind to the human zona pellucida.

Unfertilized oocytes from an in-vitro fertilization programme were stored in different saline solutions and then utilized in a zona binding assay (ZBA). The four saline solutions tested were identical with regard to the capacity of the zona to bind spermatozoa provided by healthy donors. Spermatozoa from 150 infertile patients were tested in the ZBA. The number of spermatozoa bound to the zona correlated positively with sperm concentration, the percentage sperm motility and the percentage of morphologically normal spermatozoa. The population was then divided into two groups according to the level of alpha-glucosidase activity, an epididymal marker. The average number of spermatozoa bound to the zona was diminished in the group with low alpha-glucosidase activity, even when considering strictly equivalent classes of sperm concentration, motility and morphology, respectively.

Effect of tea on iron absorption from the typical Tunisian meal 'couscous' fed to healthy rats.

Black and green tea decoctions are popular beverages in Tunisia, especially after eating. Our study was performed to examine the effect of graded amounts of black and green tea decoction prepared under realistic Tunisian conditions on nonheme iron absorption from a typical Tunisian meal, 'couscous', by extrinsic radioiron labeling in rats. Concentrations of 300, 200 and 100 micrograms/ml of black tea decreased dramatically nonheme iron bioavailability from couscous, but 50 micrograms/ml did not influence iron absorption. The inhibition of nonheme iron from couscous varied from 36 to 61% with black tea and 30.5% with green tea. Taken together, our findings show that the tea decoction in Tunisia has a great inhibitory power and may constitute an important factor for the development of iron deficiency anemia throughout Tunisia.

Bioavailability of iron from a traditional Tunisian meal with chickpeas fed to healthy rats.

The influence of a diet of couscous with chickpeas, a traditional Tunisian meal, or one providing iron as ferrous sulfate, on the utilization of 59Fe was evaluated in studies with rats. The iron content of the couscous and chickpea preparation was 30 mg/kg dry weight. There was no difference in the relative absorption of iron from ferrous sulfate or couscous with chickpeas, suggesting that iron from this preparation may be a good dietary source of nonheme iron for rats. Couscous and chickpeas consumption in Tunisia are estimated at 13.3 and 3.2 kg per capita/year, respectively. Our results in rats indicate that these foods could contribute a large proportion of an individual's iron requirement. We conclude that the plant foods, especially the chickpeas, can be excellent sources of dietary-available iron.

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)

Glycine transport by intestinal brush border vesicles of the amphibian Discoglossus pictus.

1. In order to determine the different components of glycine uptake by the intestine of the frog, Discoglossus pictus, we have used brush border membrane vesicles isolated by a classical precipitation technique. 2. Enzymatic tests showed that a good purification was obtained. The concentration ratio of alkaline phosphatase was 14.8. 3. Glycine entry in vesicles as a function of time, in presence or absence of sodium, indicated an overshoot which decreased when incubation time was prolonged. The overshoot was dependent on the presence of sodium. 4. The nature of the anion associated to sodium had little effect on glycine uptake. Nevertheless, chloride and thiocyanate appeared more efficient than glutarate. 5. The effect of transmembrane potential was studied by using valinomycin associated with a potassium gradient. The addition of this substance stimulated glycine transport by 43%. 6. The transport at different glycine concentrations showed two components: one non-saturable with weak affinity and the other saturable with strong affinity (Kt = 0.338 mM). 7. In conclusion, glycine transport by the brush border of D. pictus intestine presents a saturable component depending on sodium and on transmembrane electrical potential.

[Effect of variations of temperature on intestinal respiration and absorption of glycine in Discoglossus (Discoglossus pictus (Ott, 1837)]. / Effets des variations de la température sur la respiration intestinale et l'absorption du glycocolle chez le Discoglosse, Discoglossus pictus (Ott, 1837).

The study of intestinal respiration in vitro showed that thermal rise up to 30 degrees C increases oxygen consumption and decreases it at the beginning of 35 degrees C. The Q10, equal to 1,80 and 1,51 between 15-25 degrees C and 20-30 degrees C, suggests a stimulation, by the temperature, of enzymatic reactions rate in the respiratory chain. The measures of oxygen consumption have been conducted every 10 minutes during 120 minutes. The study of glycine absorption at the concentration 0,5 mM have been effected with in vitro technic in presence of 14C glycine. The absorption time have been fixed at 30 minutes. The glycine absorption studied at 15-20 and 25 degrees C increase with the rise of temperature. The Q10, equal to 1,76 between 15 and 25 degrees C, suggests the mechanisms existence of metabolic complexions. The water movements, at different temperatures, are always directed from physiologic liquid to intestinal tissue.

[Effects of adrenaline and acetylcholine on respiratory exchanges of the cuttlefish, Sepia officinalis L., 1958, in a non-confined environment]. / Effets de l'adrénaline et de l'acétylcholine sur les échanges respiratoires de la seiche, Sepia officinalis L., 1758 en milieu confiné.

Sepia officinalis L, a cephalopod species, is used to study the influence of adrenalin and acetylcholin on respiratory exchanges in confined environment. The results show that in constant salinity and temperature conditions, an injection of 250 micrograms of adrenalin or acetylcholin increases its oxygen need and the rate of oxygen consumption. Adrenalin and acetylcholin have synergic effects on the respiratory exchanges in confined environment.

[Absorption of D(+)glucose by the intestine of the eledone (Eledone moschata Lamarch): effect of phloridzoside]. / L'absorption du D(+)glucose par l'intestin de l'élédone (Eledone moschata Lamarck): effet du phloridzoside

"The in vivo intestinal absorption of D(+)glucose by Eledone (Eledone moschata Lamarck), a cephalopod mollusc, is decreased by 2.10(-4)M phlorizin and increased by 2.10(-2)M phlorizin. It is noted that phlorizin is dissolved in the glucose solution before its introduction into the intestinal tube. The first result is similar to that known in vertebrates; the second differs."