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F Senegas-Balas

Publications and source records attributed to F Senegas-Balas.

At least 19 recordsLinked to original sources
PubMed2001

Changes in cell proliferation and differentiation of adult rat small intestine epithelium after adrenalectomy: kinetic, biochemical, and morphological studies.

The effects of 10-day bilateral adrenalectomy on morphometry, proliferation, and apoptosis were determined in the small intestine of 3-month-old Sprague-Dawley rats. The activities of sucrase, lactase, and its respective mRNA, aminopeptidase N, and intestinal alkaline phosphatase were also evaluated. Adrenalectomy lead to partial atrophy and disorganization of the epithelium, with an increased number of goblet and Paneth cells and a reduction of crypt cell proliferation paralleled by a marked increase in villus apoptosis. Biochemical assays revealed that aminopeptidase N and intestinal alkaline phosphatase activities were significantly decreased, whereas disaccharidases were increased by adrenalectomy. The corresponding induction of lactase mRNA suggests an active response of the epithelium. In conclusion, adrenalectomy modified maturation and the differentiation processes of the small intestinal mucosa, especially in the proximal part of the small intestine. This result points to an important role of adrenals and glucocorticoids in the trophic status of the adult small intestinal mucosa.

Adrenalectomy↗
PubMed1998

Pancreatic trypsinogen I expression during cell growth and differentiation of two human colon carcinoma cells.

Pancreatic trypsin has been found to induce tight junction or dome formation in some colon cancer cell lines (HT-29, Caco-2), and a tumor-associated trypsinogen, trypsinogen type II, has been isolated from another colon cancer cell line (COLO 205). We have tried to determine if trypsinogen is present and how its expression varies during cell culture in HT-29 Glc+/- and Caco-2 cells, which exhibit enterocytic differentiation, and in HT-29 Glc+ cells, which never differentiate. Trypsinogen mRNA presence and expression were demonstrated in these cells by mRNA hybridization, RT-PCR, cytoimmunofluorescence, Western immunoblot analysis, and gel filtration. Trypsinogen was found to be trypsinogen type I and was mainly in zymogen form in culture media. Differentiating cells exhibited variations in trypsinogen I expression, but cells that remained undifferentiated did not. In the differentiated cells, a high and transient peak in trypsinogen I expression was observed during the first steps of differentiation.

Adenocarcinoma↗
PubMed1996

Immunohistological localization of regenerating protein in ocular structures.

PURPOSE: To investigate the presence of pancreatic stone protein (PSP)/reg (regenerating) protein in eyes and extraocular structures of rabbits, monkeys and man, according to species and age. METHODS: Rabbit eyes, with normal or de-epithelialized corneas, were taken from albino and pigmented animals. Monkey eyes were taken from cynomolgus monkeys, 2 years old. Stillborn and adult human eyes were obtained after autopsy. They were studied by immunohistochemistry methods, using a monoclonal antibody raised against human PSP. RESULTS: On rabbit ocular structures, the anti-PSP monoclonal antibody showed a strong reactivity at the level of basement membranes and basal poles of the cells of corneal and conjunctival epithelia and on basement membranes of skin and palpebral conjunctiva in eyelids. On de-epithelialized rabbit eyes, the remaining basement membrane was labeled while, along the re-epithelialization, the anti-PSP reactivity appeared with the migrating cells which cover the denuded cornea. On young monkeys, the whole corneal epithelium was reactive. Similar results were obtained from stillborn eyes, whereas no reactivity was detected on autopsy specimens from aged persons. CONCLUSIONS: As in other tissues and organs, the reg protein, in the eye, is found in structures known for their continuous and rapid renewal. This protein seems not to exist (or persist) in eyes from aged donors while it is strongly expressed in young donor eyes (monkey, stillborn baby) as well as in regenerating corneal epithelium. These findings enforce the hypothesis about the involvement of reg protein in cell proliferation and differentiation phenomena and its probable correlation with aging.

Aged↗
PubMed1996

Modulation of proliferation, second messenger levels, and morphotype expression of the rat intestinal epithelial cell line IEC-6 by fermented milk.

Trophic effects of milk fermented with Lactobacillus helveticus, Lactobacillus paracasei ssp. paracasei, Bifidobacterium sp., or the combination of Lactobacillus bulgaricus and Streptococcus thermophilus (yogurt) were studied on the IEC-6 intestinal epithelial cell line. Incorporation of [methyl-3H]thymidine, mitochondrial dehydrogenase activities, cyclic AMP production, and differentiation of levels of the IEC-6 strain were evaluated between the 15th and 30th passage in culture. All fermented and unfermented milks enhanced trophic responses of IEC-6 cells in a dose-dependent manner. Compared with the corresponding milks, supernatant fractions were more effective in stimulating mitochondrial dehydrogenase response. Fermented milk supernatants were also more effective than the corresponding unfermented fractions. Increases in DNA synthesis and cyclic AMP confirmed the activation observed with mitochondrial dehydrogenase. Yogurt induced the more trophic response with an increased number of the more differentiated cell morphotype. Fermentation with L. casei also demonstrated an important trophic adaptation of IEC-6 cells. Milk processing by lactic acid bacteria enhanced trophic and proliferation responses of intestinal epithelial cell line IEC-6. These results suggested that IEC-6 cells could represent an accurate and easy in vitro model for testing the trophic quality of various nutrients and for an optimization of physiological digestive functions.

Animals↗
PubMed1992

Immunohistochemical study of secretory proteins in the developing human exocrine pancreas.

We have studied, by immunohistochemical methods using specific antisera, the development of three glycoproteins of human pancreatic secretion: lipase, carboxyl ester hydrolase (CEH) and the P19 protein (precursor of the non glycosylated protein X or "pancreatic thread/stone protein"). We have compared their development to that of trypsinogens (Tgs) and chymotrypsinogen A (ChTgA), as well as to that of FAP (feto acinar pancreatic protein), a glycoprotein associated with the differentiation of human pancreas. Our studies show the characteristic appearance and development of lipase, the immunoreactivity of which appears later (at the 21st week of pregnancy) than it does for Tgs and ChTg (at the 16th week of pregnancy). Moreover, the lipase labelling is first observed in a few acini dispersed in the pancreas and then spreads out progressively to be present in all the acini after the age of 15 days. By contrast, as soon as they appear, Tgs and ChTg are observed uniformly in all acinar cells. The intensities of the lipase, Tgs and ChTg labellings increase greatly at birth. The ontogenesis of CEH does not follow that of lipase but that of Tgs and ChTg. The ontogenesis of P19 is parallel to that of Tgs. As previously observed, FAP presents a maximal immunoreactivity at the 24th-27th weeks of pregnancy, which decreases slowly up until birth.

Aging↗
PubMed1989

Effect of long-term intraluminal perfusion of pentagastrin on rat small-intestinal mucosa.

Mucosal changes occurring during long-term intraluminal perfusion of pentagastrin in the duodenum of conscious adult rats (100 micrograms/24 h/kg, 6 days) were studied. Significant increases of labelling and of mitotic indices were noted in the whole small intestine, with an enlargement of the crypt epithelial proliferative compartment. Differential kinetic variations were observed between upper and lower parts of the small intestine when labelling indices were measured in accordance with the cell position in the crypts. Kinetic variations were correlated to the increases of villous and microvillous area. Alkaline phosphatase and leucine-aminopeptidase-specific activities were significantly increased, suggesting modifications of synthesis and/or maturation of these enzymes. The ileal Paneth cell number was also significantly increased in the ileum. Pharmacologic doses of pentagastrin intraluminally perfused have a trophic effect at all levels of the small-intestinal mucosa.

Alkaline Phosphatase↗
PubMed1988

Exocrine pancreatic secretion in the elderly.

In order to evaluate impairment of exocrine pancreatic function during aging, 27 subjects (mean age: 36 years +/- 7.8) and 28 subjects (mean age: 72 years +/- 3.2), with no clinical or radiological evidence of digestive disease, were selected. Duodenal aspirates over a 60 min period were obtained during continuous IV infusion of secretin (0.5 U/kg/h) and caerulein (75 ng/kg/h). Bicarbonate, lipase, chymotrypsin amylase concentrations and output were measured. Bicarbonate, lipase, chymotrypsin concentrations in the aged group were significantly reduced by 17%, 15% and 23% respectively (P less than 0.05) as compared with those in the young group. In addition, a significant reduction of approximately 45% in bicarbonate and enzyme output levels was observed. This study provides strong evidence for a marked functional involution of the exocrine pancreatic secretion during aging. The potential consequences of this phenomenon on the nutritional status in the elderly are discussed.

Adult↗
PubMed1988

Silent human pancreatic glucagonoma and "A" nesidioblastosis.

Surgical fragments of healthy and tumor-bearing pancreas from a patient with pancreatic tumor were studied by electron or light microscopy, histochemistry, and immunocytochemistry (human insulin, glucagon, somatostatin, gastrin, and bovine pancreatic polypeptide). Histological results were compared to those obtained by radioimmunoassay, both in tumor and serum. The tumor was identified as a glucagonoma because reactions for Grimelius' silver impregnation and immunoreaction with an antiserum against glucagon were positive and because a very high level of glucagon in the tumor was observed. Insulin, somatostatin, and gastrin levels remained normal, both in tumor and serum, but the glucagon level was normal in serum. Associated with this silent glucagonoma, an uncommon nesidioblastosis was also diagnosed with many A cells irregularly mixed with acinar cells, isolated or clustered in small groups. Acinar "intermediate" cells of "A" type were also observed. Such associative histopathological processes evoked possible development of an endocrine tumor from nesidioblastic-like tissue. Its embryogenic origin remained uncertain.

Adenoma, Islet Cell↗
PubMed1985

Long-term comparative effect of cholecystokinin and gastrin on mouse stomach, antrum, intestine, and exocrine pancreas.

Mice were injected three times a day for 12 days with 300 micrograms/kg body weight of gastrin G17 or 37.5 Ivy dog U/kg body weight of CCK or saline. Other mice were also injected four times an hr for 1 hr with 7.5 micrograms/kg of gastrin, nine Ivy dog U/kg of CCK or saline; 1 hr before killing, they were injected with tritiated thymidine to evaluate the labelling indices in peptic, antral, duodenal, jejunal, and ileal mucosae. Four hours after the first injection of the two peptides, the peptic labelling indices increased while those of intestinal mucosa increased 8 hr after these injections. Long-term injections of CCK had a trophic effect on secretory cells of the digestive tract: the number of gastric zymogenic cells, Paneth cells, and the mucous cells of Brünner glands were hypertrophied. The pepsin, amylase, chymotrypsin, and lysozyme activities increased in stomach, exocrine pancreas, and intestine, respectively. Neither parietal cells nor intestinal enterocytes and hydrolase activities were affected. The trophic effect of long-term injections of gastrin is confirmed on parietal cells and exocrine pancreatic parenchyma and is demonstrated in Paneth cells. Confirming cytological results, pancreatic lipase and amylase activities and intestinal lysozyme activity were increased after gastrin. Although CCK and gastrin have a structural analogy, these two peptides did not affect the same cellular types. A specific action of CCK on the main secretory cells of the digestive mucosa is demonstrated.

Amylases↗
PubMed1985

Long-term effect of somatostatin 14 on mouse stomach, antrum, intestine and exocrine pancreas.

Mice were injected 3 times a day for 12 days with 8 micrograms/kg of somatostatin 14 which caused a hypoplasia of parietal and goblet cells, a hypotrophy and hypofunctionality of pancreatic acinar cells with a decrease in lipase and chymotrypsin activities, a decrease in the secretory fuction of the Brunner gland and in the number of dark granules of G cells. Neither villous and microvillous areas nor brush border hydrolase activities were affected. The number of peptic cells and Paneth cells increase as the level of pepsin and lysozyme. Mice were injected 4 times per hour with 2 micrograms/kg of somatostatin. 2 h after the first injection of somatostatin and 90 min after a single injection of tritiated thymidine, fundic, antral, jejunal and ileal labelling indexes strongly decrease (maximal effect in ileum). The inhibitory effect of somatostatin on the digestive epithelial cell proliferation compared to its long-term action only directed on specific cell types evokes probable compensatory mechanisms induced to maintain the equilibrium of the digestive epithelia.

Animals↗
PubMed1984

Immunohistochemical localization of intestinal phospholipase A2 in rat paneth cells.

Using the peroxidase-anti-peroxidase (PAP) technique with a specific rabbit anti-swine intestinal-phospholipase-A2 serum, the immunoreactivity of this phospholipase A2 was localized in rat-intestinal Paneth cells. The specific rabbit anti-swine intestinal-phospholipase-A2 serum did not stain the rat-pancreatic acinar cells which were stained by a specific rabbit anti-swine pancreatic-phospholipase-A2 serum. Specific rabbit anti-swine pancreatic-phospholipase-A2 serum did not stain rat-intestinal Paneth cells. Therefore, there is no cross-immunoreactivity between pancreatic and intestinal phospholipases.

Animals↗
PubMed1982

Histological variations of the duodenal mucosa in chronic human pancreatitis.

From 16 volunteers with chronic pancreatitis and 36 healthy subjects duodenal biopsies were taken 15--20 cm beyond the papilla of Vater. Several morphometric parameters were calculated. The main results show: a significant decrease of villous area and height but not of the number of intestinal villi; a significant increase of Paneth cells; and a slight decrease in the number of glandular mitoses. This study suggests in man, a possible relationship between exocrine pancreatic secretion and the intestinal mucosa and a trophic action of pancreatic juice on the proliferation and the differentiation of the intestinal mucosa.

Biopsy↗
PubMed1981

Effect of pancreatic duct ligation on the hamster intestinal mucosa. Variation of several hydrolases.

Hamster intestinal hydrolase activities were studied after pancreatic duct ligation for periods of 5, 7, 10, 15 and 30 days. From the 7th to the 10th day, maltase and sucrase were significantly increased in the jejunoileum. Higher levels were observed on day 7 in the duodenum for all the brush-border enzyme activities (maltase, sucrase, aminopeptidase, alkaline phosphatase). Intestinal lysozyme significantly increased from the 5th to the 15th day with a maximal level at the 7th day. The increased levels of brush-border enzymes observed here are not in accordance with our description of villous atrophy after pancreatic duct ligation in the hamster. On the other hand, the important increase in lysozyme activity is in good agreement with hypertrophy and hyperplasia of the Paneth cells which we observed during our morphological study. The morphological and biochemical findings on hamster small intestine confirm the effects of exocrine pancreatic secretion both on differentiation and on enzymatic levels of the mucosa. Besides, this experiment agrees with the direct desorbing action of the pancreatic juice on the brush border and suggests another hypothetical mechanism, still worth being investigated, to explain increased brush-border activities in the duodenum and increased levels of lysozyme in the jejunoileum.

Alkaline Phosphatase↗
PubMed1981

Long term effects of H2-receptor antagonists (cimetidine and ranitidine) on the human gastric and duodenal mucosa.

Cytological effects of two H2-receptor antagonists on the gastric and duodenal mucosa were studied during therapy of active duodenal ulcer (D.U.) in man. After endoscopic diagnosis (day 0), subjects were treated with cimetidine or ranitidine and re-examined on day 30. Only subjects with healed D.U. on day 30 were retained in this study. Gastric, pyloric and duodenal endoscopic biopsies were taken and treated for further morphometrical analysis both by light and electron microscopy. The use of the immunoperoxidase technique allowed evaluation of G and D cell populations. Kinetic parameters in proliferative zones were measured after in vitro incubation of biopsies with 3H-thymidine. No differences could be seen between the two H2-receptor antagonists. Increase of tubulovesicles and decrease of canaliculi in parietal cells are closely related to the inhibitory effect of these drugs on acid secretion. However secretory capacities of parietal cells are preserved since the whole membrane (tubulovesicle + canaliculi surface) remained constant. The collapsed aspect of the tubulovesicles on day 30 and the presence of connections between the tubulovesicle membrane, with both vesicle and canaliculi membrane, could support the theory of osmotic membrane expansion during parietal cell acid secretion. H2-receptor antagonists have been shown to be trophic in duodenal mucosa: both villi and microvilli area are increased. Confirming these findings, the proliferative compartment in the intestinal crypts was shown to be enlarged. No variation of G cell number could be seen in the antral mucosa; clear intracytoplasmic granules were increased in D.U. on day 0 but were not further modified on day 30. Somatostatin labelling index decreased. These last findings associated with the lack of G cell variations, suggest the presence of a possible paracrine modulation in the gastric and duodenal mucosa.

Biopsy↗