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Biomedical subjects

D Perrin

Publications and source records attributed to D Perrin.

At least 19 recordsLinked to original sources
PubMed1992

No evidence for calpain I involvement in fodrin rearrangements linked to regulated secretion.

Stimulation of secretion in chromaffin and parotid acinar cells is associated with dramatic rearrangements of the subplasmalemmal cytoskeleton, notably of fodrin and F-actin. It has been proposed that a proteolytic cleavage of fodrin resulting from an activation of the neutral calcium activated protease (calpain) could be responsible for these changes. Using an affinity-purified anti-alpha-fodrin antibody, several cleavage products of fodrin could clearly be detected following incubation of total cell homogenates from chromaffin and parotid acinar cells with purified calpain I. On the other hand, maximum stimulation of secretion of chromaffin cells by nicotine, and of parotid acinar cells by carbachol plus isoproterenol, was not associated with an increased appearance of cleavage products of fodrin. This result is not compatible with the 'proteolytic cleavage' hypothesis.

Adrenal Medulla↗
PubMed1992

Does elective sclerotherapy improve the efficacy of long-term propranolol for prevention of recurrent bleeding in patients with severe cirrhosis? A prospective multicenter, randomized trial.

We conducted a prospective, multicenter, randomized trial to compare the efficacy of sclerotherapy plus propranolol with that of propranolol alone in the prevention of recurrent gastroesophageal bleeding in severely cirrhotic patients. For 2 yr (1987 to 1988) 131 patients (96% of whom were alcoholic) with Child-Pugh class B or C cirrhosis (56% were class B and 44% were class C) were randomly assigned to one of our two treatment groups after cessation of variceal bleeding, without hemostatic sclerosis, and were observed for at least 2 yr. Treatment observance was good in 89% of cases; alcohol withdrawal was observed in 62% of cases. Sclerotherapy was performed weekly with 1% polidocanol, and variceal obliteration was obtained in 83% of cases, in a mean number of four sessions. The cumulative percentages (expressed as mean +/- S.D.) of recurrent bleeding at 2 yr were 42% +/- 6% for propranolol plus sclerotherapy and 59% +/- 6% for propranolol alone (a nonsignificant difference). Twenty-eight patients from the propranolol group but only 12 patients from the propranolol-plus-sclerotherapy group had recurrent bleeding from esophageal variceal rupture (p less than 0.01). The total number of blood units per patient with recurrent bleeding was slightly but not significantly more important in the propranolol group (8 +/- 7) than in the propranolol-plus-sclerotherapy group (5 +/- 5; p = 0.09).(ABSTRACT TRUNCATED AT 250 WORDS)

Esophageal Diseases↗
PubMed1992

cAMP and Ca(2+)-mediated secretion in parotid acinar cells is associated with reversible changes in the organization of the cytoskeleton.

The potential involvement of actin and fodrin (brain spectrin) in secretory events has been assessed in primary cultured guinea pig parotid acinar cells, using as a tool affinity purified anti-alpha-fodrin antibody, phalloidin, and immunofluorescence techniques. In resting parotid acinar cells fodrin and actin appeared as a continuous ring under the plasma membrane of most of the cells. Upon stimulation with secretagogues fodrin and actin labeling at the level of the plasma membrane disappeared almost completely. To establish a correlation between secretion and cytoskeletal changes at the individual cell level, anti-alpha-amylase-antibodies were used to label secreted amylase exposed at the surface of secreting cells. The number of cells expressing alpha-amylase on their surface followed bulk secretion of alpha-amylase. A strict correlation between secretion and alteration of the actin-fodrin labeling was observed at the individual cell level. The cytoskeletal changes occurred in parallel with secretion independently of the secretagogue used (carbamoylcholine in the presence of Ca2+, isoproterenol in presence or absence of Ca2+, forskolin, or dibutyryl-cyclic-AMP). The changes were reversible upon removal of the secretagogue. Since Ca2+, as well as cAMP-mediated secretion, was associated with the same kind of cytoskeletal changes, a reorganization of the cytoskeleton may play an essential part in regulated secretion.

1-Methyl-3-isobutylxanthine↗
PubMed1991

[Prevention of recurrent hemorrhage in patients with cirrhosis. Results of a controlled trial of propranolol versus endoscopic sclerotherapy].

Between July 1984 and March 1986, we conducted a prospective randomized trial comparing propranolol and endoscopic sclerotherapy in the prevention of recurrent variceal hemorrhage in a group of non selected alcoholic cirrhotics. Seventy-six patients with variceal hemorrhage were randomized to receive propranolol (P) (34 patients), or sclerotherapy (S) (42 patients) approximately 12 days after initial bleeding. The 2 groups were similar as concern age, sex, etiology of cirrhosis, severity of liver failure, the number of previous hemorrhages, and the severity of initial hemorrhage. No side effects were observed in the P group; 20 patients (48 percent) in the group S had at least one side effect although minor. After an average follow-up of 36 months, 18 patients in group P (53 percent) and 23 in group S (55 percent) had hemorrhagic recurrence. Rebleeding occurred from other sources than esophageal varices in 5 patients, in the group S only. Five patients in group P and 8 patients in group S died of rebleeding. During the follow-up period, 8 patients in group P (23 percent) and 13 patients in group S (31 percent) died. No significant difference could be demonstrated between the 2 groups as regards the percentages of patients without variceal rebleeding or survival, calculated according to the Kaplan Meier method. In conclusion, in this trial, no significant difference could be demonstrated between propranolol and endoscopic sclerosis in the prevention of recurrent variceal hemorrhage in alcoholic cirrhotic patients.

Actuarial Analysis↗
PubMed1991

[Cranio-maxillo-facial fibrous dysplasia].

The fibrous dysplasia of the bones is a big disease, but it has to be considered as an expansive process with local malignancy in the cranio-maxillo-facial localizations. After a review of the literature, 7 cases of fibrous dysplasia are presented. The only curative treatment is surgical, generally mutilating, it has to be completed by a restoring intervention in same time. The abstention and the modeling surgery can be indicated exceptionally, it requires a regular X ray examination, and a clinical follow-up.

Adolescent↗
PubMed1979

Bacteriophage lambda-E. coli K12 vector-host system for gene cloning and expression under lactose promoter control. II. DNA fragment insertion at the vicinity of the lac UV5 promoter.

Bacteriophage vectors derived from lambda plac5 have been constructed. Their genomes have one EcoRI restriction site which is located at the very beginning of the lac Z gene. The major part of this gene was deleted by an in vivo intramolecular recombination. These vectors allow the fusion of a gene or an operon with the beginning of the lac Z gene, placing them under the control of the lac promoter, which carries the UV5 mutation. Some of these vectors (lambda Y) also include the lac Y gene and it too is under the control of the lac promoter. The lambda YEQS, which carries the Qam73 and Sam7 mutations, as safety mutations, has been certified as a B2 (EK2) vector by the French control commission "recombinaison génétique in vitro".

Coliphages↗
PubMed1979

[A vector system designed to allow excretion of a protein encoded by a cloned gene].

We describe a method which should allow construction of bacterial strains able to export a given protein through the cytoplasmic membrane. The principle is to fuse the structural gene of the protein to the proximal part of gene lamB, the structural gene of the lambda receptor, an outer membrane protein of E. coli K-12.

Bacterial Proteins↗
PubMed1979

Preservation of the effects of pregnancy on rat islets of Langerhans in tissue culture.

Islets of Langerhans, isolated from normal or 19-day pregnant rats, were cultured for 20 h at 37 degrees C in tissue culture medium 199. When islets were cultured in medium containing low glucose (5.5 mM), the higher adenylate cyclase activity and insulin secretory responses characteristic of islets from pregnant rats were maintained during the test period of 29 h. Islets from normal and pregnant rats were also cultured for 20 h in medium containing a very high glucose concentration (83.3 mM) in order to load the B cells with glycogen. It was found, after glycogen loading, that, while adenylate cyclase activity increased to a greater extent in islets from pregnant rats than controls, this activity was not increased in proportion to the striking changes in insulin release rate observed in pregnant rat islets. The results show that the difference in insulin secretory response between islets from normal and pregnant rats may be preserved when the islets are cultured for 20 h, and that these differences are enhanced for a variety of reasons after culture of islets in 83.3 mM glucose.

Adenylyl Cyclases↗