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Y Minaire

Publications and source records attributed to Y Minaire.

At least 37 records · Page 2Linked to original sources
PubMed1994

[13C-urea breath test for the diagnosis of Helicobacter pylori infection. Comparison with histology].

OBJECTIVE: This study was to evaluate the 13C-urea breath test for the diagnosis of Helicobacter pylori infection compared with pathological data of gastric antrum and fundus endoscopic biopsies. METHODS: In 95 patients, the results of the 13C-urea breath test were retrospectivally compared with histology (standard and Giemsa staining). RESULTS: Using a ROC curve, the best cut-off value for the 13C-urea breath test was determined at + 3 delta 0/00 of breath isotopic enrichment. Compared with histology, the diagnostic values of the 13C-urea breath test were: sensibility 90.3%, specificity 97%, positive predictive value 98.2%, negative predictive value 84%. The false negative results of the breath test (6 out of 95) were obtained in patients with few H. pylori present in antral biopsies, or in patients under omeprazole therapy. The urea breath test was well correlated with the inflammation of the gastric mucosa (P < 0.0001). The isotopic enrichment in breath was well correlated to the number of H. pylori estimated by histological analysis (P < 0.05). CONCLUSIONS: The 13C-urea breath test is a non invasive and non radioactive diagnostic tool for H. pylori infection. Its excellent positive predictive value and its good negative predictive value guarantee its usefulness in clinical practice, especially for the control of eradication after anti-H. pylori therapy.

Biopsy↗
PubMed1994

[Effect of enprostil on the healing and the recurrence of duodenal ulcer. Comparison with ranitidine].

Enprostil, a synthetic prostaglandin E2, has been shown to exert both antisecretory and mucoprotective activity. It is effective in duodenal ulcer healing. OBJECTIVE--This study was performed to compare the frequency and the delay of spontaneous duodenal ulcer relapse during a two-year follow up period after initial healing by enprostil (35 micrograms, twice a day) or ranitidine (300 mg per day). METHODS--This multicentric, double-blind, randomized study included 642 patients (324 in the enprostil group and 318 in the ranitidine group). Patients included in the follow up period were evaluated by an endoscopy at 6 months, one and two years after healing. RESULTS--After a 6 weeks treatment period, healing rate was 85% for ranitidine and 70% for enprostil, respectively (P < 0.001). Adverse effects, especially digestive ones, occurred more often with enprostil than with ranitidine (P < 0.001). After initial healing, there was no significant difference between the 2 groups concerning the cumulative rate of relapse, despite a non significant trend for a milder rate of relapse in the enprostil group (P = 0.08). Twenty-seven % of the patients randomized to treatment (intend-to-treat analysis) in the enprostil group and 29% in the ranitidine group had no ulcer recurrence 6 months after ulcer healing, and respectively 12% and 13% at 2 years (difference not statistically significant). CONCLUSIONS--It is concluded that a) ranitidine is more effective and has less adverse effects than enprostil for duodenal ulcer healing, b) after duodenal ulcer healing by enprostil, there is a non significant trend for a lower rate of relapse than after healing with ranitidine, c) there is the same proportion of patients without ulcer in the 2 groups after 6 months and 2 years.

Adolescent↗
PubMed1994

[Variations of plasma gastrin (basal and postprandial) in ththtreatmentof duodenal ulcer with either enprostil or ranitidine. Correlations with rates of relapse].

Enprostil, a synthetic E2-prostaglandin efficacious for duodenal ulcer healing, presents both antisecretory and antigastrinic effects. This is at variance with the elevation of plasma gastrin observed with ranitidine. OBJECTIVE--This leads us to compare enprostil and ranitidine on the following points: a) variations of plasma gastrin (basal and postprandial) parameters over a 6-week conventional treatment; b) correlation studies between ulcer relapses (frequency and temporal evolution) after treatment discontinuation and various gastrinic criteria. METHODS--Among a group of 642 patients followed for ulcer relapse, 165 were considered for gastrin (78 of the "Enprostil" group and 87 of the "Ranitidine" group). RESULTS--Initially, both populations were comparable for clinical and plasma gastrin parameters. After 6 weeks of treatment, the increases in the various gastrin parameters (basal, postprandial, peak, integraded) were significantly greater and the absolute values higher (Wilcoxon, P < 0.001) with ranitidine than with enprostil. No correlation was found between relapse occurrence after drug discontinuation and these gastrin parameters. CONCLUSIONS--Ranitidine hypergastrinemia seems directly related to gastric hyposecretion whereas its absence with enprostil is likely more dependent upon a specific antigastrinic activity than on a reduced antisecretory activity. Those differences in mechanism of action have no consequence on the stability of ulcer obtained by either drug.

Adolescent↗
PubMed1993

Effect of growth hormone deficiency on hormonal control of hepatic glycogenolysis in hypophysectomized rat.

The present study was designed to investigate the hormonal regulation of rat liver glycogenolysis in growth hormone (GH) deficiency. To this end, hepatocytes were isolated from control, GH-deprived (hypophysectomized and treated with triiodothyronine [T3] and corticotropin), and 7-day GH-supplemented fed rats and incubated with glucagon and alpha 1-adrenergic agonist (phenylephrine) to measure the hormonal activation of both glycogen phosphorylase and glucose production from glycogen stores. GH deficiency induces a combined decrease of 50% of the glycogen content, the activity of glucose-6-phosphatase, and the maximal hormone-induced glycogen phosphorylase activity. Daily GH injections restore the levels of both glycogen phosphorylase and glucose-6-phosphatase. These enzymatic inductions occur without normalization of insulinemia. Despite the reduced levels of key enzymes of glycogenolysis, the stimulation of glucose production from glycogen in response to glucagon and phenylephrine is not modified in GH-deprived rats. An increase in the intrinsic activity of one or both of the enzymatic steps is postulated to compensate for the lower levels of enzymes, as indicated by the slopes of the correlation between glucose production and phosphorylase a activity (107 and 216 nmol glucose produced/min/U phosphorylase a [P < .001] in control and GH-deprived rats, respectively). GH replacement enhances maximal phosphorylase activity and brings the correlation toward the control value (slope, 128 nmol glucose produced/min/U phosphorylase a). Our findings demonstrate that glycogenolysis in hepatocytes isolated from GH-deprived rats is normal, despite a reduction of glycogen phosphorylase and glucose-6-phosphatase activities.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Morphometric-stereologic analysis of brown adipocyte differentiation in adult mice.

Brown adipocyte differentiation from interstitial stem cells was analyzed by morphometric-stereologic methods in adult mice. Confirming previous studies, four different stages of development were identified: 1) interstitial cells----2) protoadipocytes (interstitial cells with tiny lipid droplets)----3) preadipocytes----4) mature brown adipocytes. Brown adipocyte precursor cells (interstitial cells and protoadipocytes) occupied only a small fraction of total brown adipose tissue (BAT) volume (1.7 and 1.8%, respectively). Most of the BAT volume was occupied by fully differentiated multilocular cells (65% vol/vol), preadipocytes (12%), and blood capillaries (10%). The differentiation of protoadipocytes into preadipocytes was characterized by a doubling in the cellular volume (from 800 to 1,500 microns 3) that was associated with a fivefold increase in the number of mitochondria (221 to 1,464), an eightfold augmentation in mitochondrial size (from 0.042 to 0.37 microns 3), a fourfold increase in the surface density of the inner mitochondrial membrane (from 8 to 35 microns 2/microns 3), resulting in a 14-fold enlargement in the relative volume of the mitochondrial compartment (from 2 to 29%). This remarkable mitochondrial proliferation was accompanied by an increase in the number and volume of cytosolic lipid droplets. In contrast, the differentiation of preadipocytes into brown adipocytes was mainly characterized by a doubling in the size of the lipid compartment; the mean volume of single droplets increased 35 times but their number decreased 6-7 times. The mitochondrial modifications were minor; there was only a slight increase in the surface density of the inner membrane. In conclusion, the major step of brown adipocyte differentiation consists in the transformation of protoadipocytes into preadipocytes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adipose Tissue, Brown↗
PubMed1991

Fasting-induced rise in locomotor activity in rats coincides with increased protein utilization.

The aim of this study was to investigate the possible relation between the modifications in locomotor activity (on running wheel) which occur during prolonged fasting and changes in the utilization of energy reserves. In 18-week-old rats, we found that the rate of body mass loss reflects the changes in nitrogen excretion that occur over three phases of fasting: (I) initially decreasing, (II) maintained at a low level and (III) increasing. Locomotor activity started to increase during phase II without a change in its nycthemeral pattern. By contrast, the 10-fold higher daily locomotor activity that occurred in phase III was marked by a higher proportion of diurnal activity. Using 9-, 18-, and 33-week-old rats, in order to obtain a different timing in the metabolic changes during fasting, we could confirm the coincidence between the later rise in locomotor activity and the occurrence of phase III. Refeeding of rats of either age in phase III rapidly suppressed fasting-induced changes in locomotor activity. These data accord with the idea that behavioral changes reflecting the search for food are triggered by a later and reversible change in the utilization of body protein vs. lipid stores during prolonged fasting.

Animals↗
PubMed1991

Resistance of hepatic glycogen to depletion in obese Zucker rats.

Glycogen stores (liver and carcass) have been studied in lean and obese Zucker rats. The animals were submitted to one of three feeding conditions: ad libitum, a 48-h fast, or a 48-h fast and food ad libitum for 24 h, and to two environmental conditions, either thermoneutrality or an acute cold exposure (2 days at 4-7 degrees C). After a 2-day fast at 25 degrees C, the liver glycogen store was reduced by 45 times in the lean rats, while it was decreased by only 3 times in the obese rats. Under these conditions, the liver glycogen store was 45 times higher in the obese than in the lean rats. After 2 days in the cold, liver glycogen store was 4.4 times higher in obese rats than in lean rats. After a 2-day fast in the cold, the liver glycogen store in the obese rats was 30 times higher than in the lean rats. In comparison to fasting at thermoneutrality, fasting in the cold did not lead to a further reduction in hepatic glycogen in obese Zucker rats. The differences observed in the mobilization of the hepatic glycogen store between obese and lean rats have not been found in the mobilization of the carcass glycogen store. Drastic conditions, such as a 2-day fast in the cold, did not exhaust the glycogen store in obese Zucker rats. The present observations point out that obese Zucker rats cannot mobilize the entire hepatic glycogen store, as seen in lean control rats. The role of this abnormality in the high hyperlipogenesis that maintains the obese state is still to be evaluated.

Analysis of Variance↗
PubMed1990

Increase in cytochrome oxidase capacity of BAT and other tissues in cold-acclimated gerbils.

To determine the effects of cold acclimation on the oxidative capacity of different tissues and their possible role in nonshivering thermogenesis (NST) in a desert rodent, the gerbil (Gerbillus campestris), measurements of cytochrome oxidase activity (COX) were performed on homogenates of liver, brown adipose tissue (BAT), and subsarcolemmal (SS) and intermyofibrillar (IMF) fractions of skeletal muscle. Total organ mass was also measured. Gerbils were maintained either at thermoneutrality (TN) or cold [4 degrees C, ambient temperature (Ta)] for 4 (CA4) or 8 (CA8) wk. A comparative study was made with mice (Mus musculus). Total and relative masses of BAT increased significantly in both gerbils and mice during cold acclimation, whereas muscle mass decreased in CA4 gerbils. Specific and total COX (TCOX) increased in the three tissues. A considerable increase (+170%, P less than 0.05) of TCOX and protein content in liver of CA4 gerbils compared with controls was observed, whereas no significant changes occurred in liver of CA4 mice. In muscle, an increase of TCOX in SS and a reduction in IMF cell compartments were noted. The increase in BAT oxidative capacity in CA4 gerbils represented only a small portion of that in liver (36%) and in SS fraction of muscle (41%) at the same stage of acclimation. The ability of the three tissues to contribute to components of thermogenesis in vivo was evaluated. The sum of oxidative capacity of the three tissues was largely above the peak metabolic rate (PMR), whereas that of muscle exceeded maximum shivering thermogenesis, which developed both in TN and CA4 gerbils.(ABSTRACT TRUNCATED AT 250 WORDS)

Acclimatization↗
PubMed1990

Comparison between lactulose-mannitol test and 51Cr-labelled ethylene diamine tetra-acetate test in inflammatory bowel diseases.

A direct comparison was made between mannitol-lactulose and EDTA tests in 10 control subjects and in 9 and 19 patients suffering, respectively, from ulcerative colitis or Crohn's disease. The markers were orally administered in a random order and urinary recoveries were measured. At group level, significant differences were only observed in EDTA test results between control subjects and Crohn's disease patients. At the individual level, these tests exhibited poor sensitivity in ulcerative colitis, both in the inactive and active forms of the disease. In contrast, in patients suffering from Crohn's disease, the lactulose and EDTA recoveries and lactulose/mannitol ratios reached interesting figures, particularly in the EDTA 24-hr-test where 63% of the results were abnormal. This percentage climbed to 75% when active forms of the disease were selected. More interestingly, addition of abnormal results obtained with sugar and/or EDTA tests provided a significant increase in sensitivity with figures up to 90% in the entire group and 92% in patients with active forms of the disease. It is suggested that a) Neither the lactulose-mannitol test nor the EDTA test is useful in ulcerative colitis even in the active forms, b) in Crohn's disease, the sensitivity of the EDTA test is greater than that of the sugar test, c) a combination, in the same patient, of the EDTA and sugar tests is able to provide an interesting percentage of sensitivity.

Adult↗
PubMed1989

[Nervous control of intestinal motility].

Leaving aside hormonal factors which should not be underestimated, it is now clear that digestive motility is a unitary phenomenon mainly under control of the nervous system. This system includes three discrete and somewhat redundant integrative levels: the enteric nervous system located in the digestive wall; the prevertebral ganglia and finally the central nervous system operating through more classical parasympathetic (cholinergic or not) or sympathetic (adrenergic) pathways. Nowadays, interest is concentrated upon the enteric nervous system because of its ubiquity, its potentiality, (it is able to operate highly integrative motor functions), its complexity and its neurochemical diversity. This last feature will provide, in the future, numerous opportunities for pharmacology and therapeutics.

Central Nervous System↗
PubMed1989

Sham feeding for testing gastric secretory capacities before and after parietal cell vagotomy.

The usefulness of acid secretory data collected during a modified sham-feeding (MSF) test was examined in 50 patients suffering from duodenal ulcer before and after parietal cell vagotomy. In these patients basal acid output pentagastrin-stimulated acid output and MSF-stimulated acid output were measured. Preoperative MSF-stimulated acid output was found to be correlated with preoperative basal acid output, and postoperative MSF-stimulated acid output was correlated with both preoperative basal acid output and postoperative basal and pentagastrin-stimulated acid outputs. The addition of preoperative MSF-stimulated acid output to preoperative pentagastrin-stimulated acid output did not noticeably increase the close relationship between the latter and postoperative pentagastrin-stimulated acid output. It is concluded that basal and MSF-stimulated secretory rates overlap. Therefore, it is suggested that in both preoperative and postoperative conditions the addition of the sham-feeding test to the more simple basal and pentagastrin-stimulated studies could be discarded.

Adolescent↗
PubMed1989

Sleep changes in fasting rats.

The proportion and the distribution of wakefulness (W) slow-wave sleep (SWS) and paradoxical sleep (PS) were studied in 27-week-old rats over 24 hr periods, both in the fed state and after having been deprived of food for 2 to 3 weeks. In these rodents, prolonged fasting has been characterized by 3 successive metabolic phases which have been found to correspond to changes in protein metabolism. Sleep-waking changes were not studied during the first phase which was often of short duration (24 hr). During the second phase, i.e., when proteins were spared, the 24 hr proportions of W and sleep states remained unchanged. There were, however, profound changes in the daily mean episodic characteristics of each vigilance state (duration and frequency) except in the case of PS. During the phase II, the differences in the day/night proportions observed in each vigilance state were less than in the fed state. This reflected a lowering in the amplitude of their daily rhythms. In contrast, when protein use rose (phase III), W was increased sharply at the expense of SWS and PS, the latter being almost completely suppressed. During this last phase, which was also of short duration (by mean 3 days) alertness was greatly enhanced and the rats, which were typically nocturnal when fed, became diurnal. The changes in sleep and wakefulness were examined in relation to their effects on the homeostatic and cyclic components of sleep mechanisms and adaptive strategy to food deprivation in rat.

Animals↗
PubMed1989

Nonshivering thermogenesis and adaptation to fasting in king penguin chicks.

The ability to develop nonshivering thermogenesis (NST) and the effect of fasting on thermogenic response to cold were studied in winter-acclimatized king penguin chicks. Metabolic rate (MR) and integrated electrical muscle activity were measured at different ambient temperatures. In cold-acclimatized (5 degrees C) fed chicks, shivering threshold temperature (STT) was 9.4 degrees C lower than lower critical temperature (LCT), indicating that NST (0.7 W/kg) occurs at moderate cold, whereas in control chicks fed and reared at 25 degrees C for 3 wk, LCT and STT were similar. Chicks reared in the cold and fasting for 3 wk or 4-5 mo (natural winter fast) developed an NST of 0.8 and 2.4 W/kg, respectively, despite the fast. In fasting chicks, the intercept of the metabolic curve with the abscissa at zero MR was far below body temperature, contrasting with the classic model for heat loss. Their low LCT indicates the capacity of a large reduction in convective conductance characteristic of diving animals and allows energy sparing in moderate cold. Below LCT, conductance reincreases progressively, leading to a steeper than expected slope of the metabolic curve and allowing preservation of a threshold temperature in the shell. These results show for the first time in a wild young bird the development of NST after cold acclimatization. Further, at the temperature of cold acclimatization, an energy-sparing mechanism is shown in response to long-term fast adaptation.

Acclimatization↗
PubMed1988

Great adaptability of brown adipose tissue mitochondria to extreme ambient temperatures in control and cold-acclimated gerbils as compared with mice.

1. The gerbil (Gerbillus campestris) is a desert rodent able to tolerate high (38 degrees C) and low (-20 degrees C) ambient temperatures, probably due to both its low resting metabolic rate in hot environment and its high peak metabolic rate in cold. 2. Measurement of mitochondrial state IV respiration and cytochrome-oxidase activity (COX) were made in interscapular brown adipose tissue (IBAT), liver and hind limb muscles of gerbils and mice of nearly equal body mass, acclimated for 4 weeks at cold ambient temperature (CA) or reared at thermoneutrality (TN). 3. The most striking difference between these two animal species appears to be in IBAT mitochondria: in TN animals, the level of state IV respiration and COX activity was lower in gerbils than in mice, but the cold acclimation-induced increase in these parameters was greater in gerbils than in mice. 4. Alternatively, in gerbils as in mice, cold acclimation induced a reduction in muscle mitochondrial COX activity. No important change due to cold acclimation was observed in liver mitochondria, either in gerbils or in mice. 5. As compared with mice, the lower state IV respiration in IBAT mitochondria from TN gerbils may explain their low RMR, whereas the higher COX activity of IBAT mitochondria from CA gerbils may explain their higher PMR. 6. As a result of this great adaptability of BAT mitochondria, the gerbil seemed to be able to live in a wide range of ambient temperatures in its natural habitat.

Acclimatization↗
PubMed1988

Assessment of the lactulose-mannitol test in Crohn's disease.

The mannitol-lactulose intestinal permeability test was evaluated in 100 healthy controls and 47 patients with Crohn's disease. These patients were further separated into three subgroups of increased activity (Harvey-Bradshaw index) and in two subgroups, with elective colonic lesions and associated ileal and colonic lesions. Results were given as percentages of urinary recoveries for mannitol (M), lactulose (L), and L/M ratio. As a whole, patients with Crohn's disease have lower mean M and higher mean L and mean L/M ratios than controls. The magnitude of alterations in M, L, and L/M increased with activity. The sensitivity of the test, however, reached interesting figures (67%:L and 86%:L/M) only in subgroup III which was composed of relapsing patients. Mean M was lower in patients with associated ileal lesion but, whatever the criterion (M, L, or L/M), the test does not provide any clue for the detection of a possible infraclinical associated ileal localisation.

Adolescent↗
PubMed1988

[Congenital intrinsic factor deficiency. Apropos of 3 cases in a sibship].

Three familial cases of congenital intrinsic factor deficiency are reported: the stress is put on the interest of gastric investigations and especially of the quantity of intrinsic factor in the gastric juice when investigating megaloblastic anemia due to vitamin B12 deficiency. The study of the level of intrinsic factor in the gastric juice is proposed as a test for identifying carriers.

Anemia, Macrocytic↗
PubMed1987

Effect of 40749 RP on basal and sham feeding stimulated gastric secretion in man.

40749 RP, a pyridyl-2-tetrahydrothiophene derivative, is known to be a potent inhibitor of the gastric acid response to pentagastrin, betazole and a meal. In 6 healthy young volunteers, a single oral dose of 2 mg.kg-1 greatly reduced the gastric acid secretory response to sham-feeding. By contrast, neither gastric pepsin nor the plasma PP response were altered by the drug. No change was observed in plasma gastrin, motilin, VIP or somatostatin concentrations. The results show that 40749 RP is also active on the pure vagus-stimulated gastric acid secretion. The lack of effect upon gastric pepsin and plasma PP suggests that 40749 RP is not likely to act on the basolateral cholinergic receptor and that it affects further cellular steps involved in hydrogen ion secretion.

Adult↗