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Biomedical subjects

A Durand

Publications and source records attributed to A Durand.

At least 145 records · Page 8Linked to original sources
PubMed1986

[Morphologic and functional study of a human insulin-secreting cell line].

Monolayer cell cultures were obtained from a human insulinoma (HIN) after collagenase digestion. HIN cells were initially plated on extracellular matrix (ECM) secreted by bovine corneal endothelial cells. Capsular integrity from cell clusters quickly interrupted and cell began to migrate as adhesive sheets onto ECM. After 2 months on ECM cell attachment and proliferation occurred on plastic allowing cloning of cells by limiting dilution. 9 clones were successfully cultured for 7 months with 20 subsequent passages. Immunoreactivity for insulin by indirect immunofluorescence typical secretory granules by electron microscopy and stable amounts of immunoreactive insulin in culture media suggest that HIN cells are beta cell related. One clone HIN D8 when challenged for half an hour with either 30 mM glucose, 1 mM isobutyl Methylxanthine 4 mM Tolbutamide, 10(-6) M glucagon responded respectively with a 1.5, 2, 3 and 1.5 fold increase in insulin output. Population doubling time of HIN D8 was 42 hrs. Establishment of such insulin secreting cell lines provides a valuable tool for diabetes research.

Adenoma, Islet Cell↗
PubMed1986

Protein enrichment of sugar beet residue with the inoculation of conidia of Trichoderma album by solid state fermentation.

Cellulosic material was inoculated with Trichoderma album by solid state fermentation and the change of protein, total nitrogen, mineral nitrogen, cellulose and total fiber contents of raw material were measured. It was found that the water holding capacity and bulk density of substrate increased as the fermentation progressed. The optimum C/N ratio for the conidia production was between 4 and 7, and the optimum pH was around 5. The protein enrichment of sugar beet residue were the best at the initial moisture content 76%, initial pH 4.5 and supplement with 1% nitrogen. After 4 days fermentation, the final product contained 22% of protein. From the present state of technological development, the protein enrichment of cellulosic materials by solid state fermentation proved to be valuable.

Fermentation↗
PubMed1985

Determination of citalopram, amitriptyline and clomipramine in plasma by reversed-phase high-performance liquid chromatography.

The determination of citalopram, amitriptyline, clomipramine and their desmethyl metabolites after alkaline diethyl either extraction from plasma is achieved by high-performance liquid chromatography using two internal standards and mu Bondapak C18 as stationary phase. Elution is carried out isocratically at 0.5 or 1 ml/min with a mixture of acetonitrile-potassium dihydrogen phosphate-distilled water (45:50:5). Detection is monitored by absorption at 254 nm. The detection limit is less than 5 ng/ml for each compound. The coefficients of variation are between 1.3% and 9.4% for 8-360 ng/ml. Interference from 22 possible co-medications is discussed. The technique can be used for therapeutic monitoring of these antidepressants as well as in analytical toxicology.

Amitriptyline↗
PubMed1985

Morphological and functional effects of extracellular matrix on pancreatic islet cell cultures.

Extracellular matrix (ECM) has been reported to enhance epithelial cell attachment and proliferation as well as to induce differentiation in vitro. In an attempt to determine the benefits of culturing pancreatic islet cells on ECM, we studied the morphological and functional patterns of rat islet cells and an insulin-secreting tumor cell line. ECM enhanced islet cell attachment and proliferation when compared to plastic, as suggested by a higher specific activity of DNA synthesis and a higher mitotic index. Cells on ECM were heterogeneous in size and insulin content. They showed extended areas of confluence. Cultures on plastic demonstrated an organisation in clusters and low mitotic activity. However, ECM did not allow for reconstitution of an islet-like structure. When compared to plastic, an initial decrease in basal and stimulated insulin secretion per million cells was observed on ECM, but B-cell activity was restored after 6 days of culture. Glucagon and somatostatin secretion were similar on both substrates. These data suggest that ECM enhances markedly islet cells attachment and proliferation, as well as long-term culture maintenance.

Animals↗
PubMed1985

Effect of indolamines on beta-endorphin release by rat anterior pituitary cells.

The effect of indolamine derivatives on beta-endorphin (beta-end) release has been studied in vitro using rat anterior pituitary cells. Incubation of primary cultures for 2 h with 100 nmol/l of melatonin, serotonin or 5-methoxytryptamine significantly increased the beta-end release in response to 20 nmol/l of ovine corticotropin-releasing factor (oCRF). Incubation of the cultures with 100 nmol/l of L-tryptophan, 5-hydroxy-L-tryptophan, 5-hydroxytryptophol or 5-methoxytryptophol had no effect on basal or CRF-induced beta-end release. The effect of serotonin and melatonin was further tested in a superfusion system of dispersed rat anterior pituitary cells. Superfusion with oCRF (200 nmol/l) for 4 min elicited an immediate rapid increase in beta-end release which lasted 30-40 min. Simultaneous superfusion with melatonin (1 mumol/l) or serotonin (1 mumol/l) significantly increased the effect of oCRF pulses on beta-end release. We conclude that melatonin and serotonin are able to act directly on anterior pituitary cells to potentiate the effect of oCRF on beta-end release.

5-Hydroxytryptophan↗
PubMed1985

[Human monoclonal antibodies against surface antigens of Langerhans cells from lymphocytes of diabetics transformed by Epstein-Barr virus].

Human monoclonal antibody against islet cell surface antigens was generated from a pre-diabetic patient's peripheral blood lymphocytes transformed with Epstein-Barr virus. Reactivity of these transformed lymphocytes was evaluated using indirect immunofluorescence on rat islet cell suspensions and frozen sections of human pancreas. Several lymphoblastoid cell lines that react with islet cell surface were obtained. Preliminary immunoblots with enriched rat islet cell membrane antigens suggest a reactivity toward a 64 kdalton antigen.

Animals↗
PubMed1985

[GRF and human somatotropic adenoma. In vivo and in vitro correlations between GH release and morphological and immunocytochemical aspects].

Nine somatotropic adenomas identified by histological and immunocytochemical methods were studied in vitro during 40 days. The spontaneous release of GH decreased at various rates according to adenomas. A decrease in the size, number of secretory granules and in immunoreactivity with anti-hGH serum were also noted. When cortisol was added (350 nM), the GH secretion sustained for a longer time or even increased at its initial level. The effect of GRF (hpGRF1-44NH2, 10(-8)M) on GH release was tested by 3 hours incubation at 6-9 days of culture. The increase in GH varied from 106 to 420% compared to the basal release. It was similar to in vivo release in 3 out of 6 cases. The highest responses were found in densely granulated and strongly immunoreactive adenomas. The effect of GRF on the GH synthesis was studied by continuous incubation of GRF (10(-8)M) from the 10th the 40th day of culture. The quantity of GH in the culture medium was never higher than in culture mediums without GRF. No change in GH concentrations in mediums with or without cortisol was found when TRH (2.5, 10(-6)M) or TRH + GRF was added. No change in morphological and immunocytochemical cell characteristics were noted either with or without GRF. Thus, the variability of GH response to GRF in somatotropic adenomas in culture seems to be related to their morphofunctional heterogeneity. Under our experimental conditions, GRF stimulates the release of stored GH in tumoral cells but does not seem to stimulate its synthesis.

Acromegaly↗
PubMed1985

[Exclusion prenatal diagnosis of chronic familial septic granulomatosis].

We report the prenatal diagnosis in a 20 week male fetus at risk of chronic granulomatous disease (CGD). A previous affected brother was known in the family and the mother was detected as heterozygote. Three different assays were performed on fetal blood obtained under fetoscopy: cytochemical reduction of nitroblue tetrazolium (NBT), chemiluminescence after activation by opsonized zymosan or phorbol myristate acetate (PMA) and production of superoxide anion (O2-.). Results were comparable to those obtained in 6 fetuses investigated for other inherited diseases. Absence of functional polymorphonuclear defects was confirmed at birth. The use of 3 different techniques performed on whole blood for prenatal diagnosis of CGD has to be recommended instead of an isolated technique adapted to whole blood tests.

Female↗
PubMed1984

Blood and plasma kinetics of cis(Z)-clopenthixol and fluphenazine in psychiatric patients after intramuscular injection of their decanoic esters.

Whole blood and plasma concentrations of active neuroleptic drugs were measured in eight schizophrenic outpatients who had received cis(Z)-clopenthixol decanoate in Viscoleo or fluphenazine decanoate in sesame oil by intramuscular injection. Whole blood and plasma concentrations were very similar, though there was a slight tendency for blood concentrations to be higher than plasma concentrations. Maximum concentrations appeared at 1 week after administration of cis(Z)-clopenthixol decanoate, whereas the highest concentrations after fluphenazine decanoate were seen at the end of the 3-week dosage interval. Some between-individual variation and a limited within-individual variation was seen.

Adult↗
PubMed1984

[A rarely recognized metastatic localization. Secondary involvement of the occipito-cervical joint].

280 patients presenting osteophilic tumors were evaluated by conventional tomography of the cervical spine. Metastasis were found in 120 cases among which 70% had no symptoms. Axis was first concerned and sometimes lesions could not be detected on plain radiographs. Authors insist on the need of a systematic cervical spine tomographic study in patients with osteophilic tumors.

Cervical Vertebrae↗
PubMed1983

[Acute human and experimental poisoning with diethylene glycol].

Although acute poisoning with ethylene glycol (EG) used in antifreeze mixtures is well known in man, only a few reports have described acute intoxication with diethylene glycol (DEG) and only one has mentioned oxaluria. Furthermore, there is no experimental evidence that DEG is metabolized into oxalate. The ability of ethanol infusions to prevent hepatic oxidation of DEG has not been proved. Moreover, failure of this treatment has been reported by some authors. In order to resolve such questions, Wistar male adult rats possessing a hepatic alcohol deshydrogenase were given a single oral dose of 15 ml/kg-1 DEG. Rats were either untreated or treated with hydration alone or associated with bicarbonate or ethanol. Urinary output, urinary oxalate excretion, acid-base balance in peripheral blood and renal histology were studied. Acute poisoning induced metabolic acidosis, polyuria, hyperoxaluria with renal tubular necrosis and a 66% mortality. Massive hydration improved acidosis and prognosis, but mortality and renal lesions were avoided only when bicarbonate or ethanol were added. Only ethanol significantly decreased oxaluria. In acute DEG poisoning, both the mechanism and the treatment appear to be the same as in acute EG intoxication.

Acidosis↗
PubMed1983

Time dependency of adriamycin and adriamycinol kinetics.

Adriamycin was administered by IV injection to seven patients with various solid tumors at a dose of 30 mg/m2 during successive courses. Extraction was carried out by the SEP-PAK method for plasma and by solvents for urine. Plasma and urinary levels of adriamycin and adriamycinol were determined by high-performance liquid chromatography over 72-h period after injection. Pharmacokinetic parameters for adriamycin and adriamycinol were calculated for each course of treatment. The results show significant inter- and intra-individual variations in the kinetics and elimination of both compounds. The analysis of pharmacokinetic data reveals a wide variability in the fluctuations observed during the successive courses in different patients. This study confirms the time-dependency of ADR kinetics.

Adult↗
PubMed1983

Quantitation of adriamycin in plasma and urine: comparative study of radioimmunoassay and high-performance liquid chromatography methods.

The response of tumours to adriamycin, and the cardiotoxicity of the drug, may be related to its pharmacokinetics and plasma levels. Rapid and sensitive methods of adriamycin determination in plasma and urine samples are thus needed. A comparative study shows that high-performance liquid chromatography with fluorimetric detection is a reliable and specific method, but it is relatively slow and sometimes lacks sensitivity. A commercially-available radioimmunoassay kit is convenient, but there is a cross reaction with the major metabolise adriamycinol and unless the assay is combined with an extraction step, it gives erroneously high results.

Journal Article↗