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Biomedical subjects

S Gil

Publications and source records attributed to S Gil.

At least 73 records · Page 4Linked to original sources
PubMed1991

Nerve growth factor mediates monosialoganglioside-induced release of fibronectin and J1/tenascin from C6 glioma cells.

C6 rat glioma cells incubated in serum-free medium with D-[14C]glucosamine secrete, on stimulation with nerve growth factor (NGF) or monosialogangliosides (MSGs), several glycoproteins (Gps), the most prominent of which are a 270-, 220-, and 69-kDa Gp. Several growth factors, hormones, phorbol ester, and disialo- and trisialogangliosides did not stimulate secretion. Western blot analysis of the conditioned medium from C6 cells stimulated with NGF or MSG identified one distinct band of approximately 220 kDa for fibronectin and J1/tenascin, which comigrated. Antiserum to NGF prevented NGF-stimulated release and also blocked MSG-evoked release. The 220-kDa band was labeled after pulse labeling with [35S]methionine in the presence of NGF, and by a 15-min chase period radioactively labeled J1/tenascin could be immunoprecipitated. Tunicamycin drastically inhibited almost completely release of the 220-kDa Gp labeled by D-[14C]glucosamine or [35S]methionine. These results extend the range of neurotrophic properties attributed to NGF to cells of glial origin and suggest that NGF regulates secretion of extracellular matrix proteins. MSG stimulation of fibronectin and J1/tenascin secretion may be mediated by NGF or an NGF-like molecule also secreted by the C6 glioma cells.

Animals↗
PubMed1990

[Measurement of the posterior wall of the intermediate bronchus. Diagnostic value].

The posterior wall of the intermediate bronchial trunk (PWIB) is visible in most cases on profile thoracic radiographs. A retrospective study showed that it is thickened (over 3 mm) in cases of cardiac failure, right pneumonitis, adenopathy, right bronchopulmonary neoplasias and pulmonary fibrosis, either acute or chronic. The latter etiology had not yet been described in the literature. In our experience, assessment of the thickness of the intermediate bronchus provides a reliable criterium of response to treatment. The pathological mechanisms of intermediate bronchus thickening due to an increase of bronchial wall thickness or of peribronchial interstitial tissue are discussed.

Bronchi↗
PubMed1987

Selective enhancement of tubulin gene expression and increase in oligo(dT)-bound RNA in the rat brain after nigrostriatal pathway unilateral lesion and treatment with ganglioside.

Partial hemitransection of the rat nigrostriatal pathway has been applied to study changes in the expression of tubulin and actin cytoskeletal genes. RNA was isolated from ipsilateral and contralateral structures of substantia nigra and striatum tissues of lesioned or sham-operated animals by a combined proteinase K and oligo(dT)-cellulose affinity purification procedure. A significant increase in the oligo(dT)-cellulose-eluted RNA was observed in the lesioned substantia nigra and striatal tissues compared to naive controls. By 5 days, the RNA content of the lesioned nigra reached a value of 96-114.5 micrograms/mg DNA compared to 45.7-52.9 micrograms/mg DNA. Administration of GM1 gangliosides at daily intervals resulted by day 5 in a further increase (131.8-141.5 micrograms/mg DNA) in the RNA content of the lesioned but also of the sham-operated (81.9-97.8 micrograms/mg DNA) animals. By 18 hr, the lesioned nigra exhibited a four-fold increase in tubulin messenger RNA (mRNAtub) gene expression in comparison to the sham-operated animals. The substantia nigra tissue of GM1-treated animals exhibited a hybridization value for mRNAtub twice as high compared to GM1-untreated, lesioned animals. The effect of GM1 appeared selective for alpha-tubulin and beta-tubulin compared to actin transcript. The latter was also elevated in the lesioned nigra tissue above the naive or sham-operated animals. The data suggest that, after injury, cytoskeletal RNA transcripts are elevated and that GM1 may play a role in the regulation of their steady-state levels.

Animals↗
PubMed1987

Lactitol, a second-generation disaccharide for treatment of chronic portal-systemic encephalopathy. A double-blind, crossover, randomized clinical trial.

A double-blind crossover trial was performed to test the therapeutic usefulness and safety of lactitol, a beta-galactoside sorbitol, against lactose in 18 patients with chronic portal-systemic encephalopathy (PSE). The study included four periods: two for washout and two for lactitol and lactose administration. During washout periods, which lasted two weeks each, patients were stabilized with neomycin plus milk of magnesia. Lactitol and lactose were administered during four weeks each. Ten patients were randomly assigned to receive lactose (group A) and eight patients to receive lactitol (group B) first. PSE parameters, ie, mental state, number connection test performance, asterixis and blood ammonia levels were assessed fortnightly. Electroencephalographic tracings and stool pHs were evaluated at the end of each study period. After the first administration of lactose and lactitol, no statistically significant differences in PSE parameters were found. At the same stage, a significant stool acidification (P less than 0.05) was detected. It is concluded that lactitol seems to be safe and efficacious in treating patients with chronic PSE.

Clinical Trials as Topic↗
PubMed1986

Nerve growth factor and gangliosides stimulate the release of glycoproteins from PC12 pheochromocytoma cells.

PC12 pheochromocytoma cells in monolayer cultures secrete increased amounts of glycoproteins into the medium following the addition of nerve growth factor (NGF) or of brain gangliosides. After a 48-h incubation with 50 ng/ml NGF there is approximately a twofold increase in the total [14C]glucosamine-labeled, ethanol-precipitable cellular material released into the medium. Between 30 and 50% of the radioactivity is associated with a glycoprotein (Gpl) of molecular weight of 52,000; the remaining radioactivity is distributed between five and six major bands. Only a small amount (10%) is associated with a glycoprotein of Mr greater than 200,000 which might correspond to the NGF-induced large external glycoprotein. A substantial increase in the release of the glycoproteins is also seen on the addition of a variety of gangliosides including asialo GMl. This increase is independent of the presence of NGF. GMl and GDlb/GTlb but not GDla stimulate release above the levels seen in the presence of NGF. Addition of GDla (2 micrograms/ml) enhances selectively the release of various glycoproteins between 2.6- and 8-fold. The pattern of glycoprotein secretion is similar to that seen with NGF, although Gp2 (Mr 78,000) is more abundant. Stimulation of release by GDla is not accompanied by neurite outgrowth, suggesting that the glycoproteins are not directly associated with neuritogenesis. The release of these glycoproteins following the addition of NGF or gangliosides may relate to the neurotrophic properties that these two entirely different ligands exert on PC12 cells.

Adrenal Gland Neoplasms↗
PubMed1977

Gonadotrophin release in ovariectomized patients. I. Suppression by clomiphene or low doses of ethinyl oestradiol.

Administration of clomiphene citrate (150 mg/day) for 5 days to twenty-four ovariectomized patients and seven normal female patients evoked a significant release of FSH and LH in the normal control group and suppressed the gonadotrophin secretion in the castrated patients. A similar suppressive effect on gonadotrophin secretion was noted in eight ovariectomized patients treated for 10 days with low doses (50 microgram/day) of ethinyl oestradiol. It is suggested that in the ovariectomized hypoestrogenic patients, clomiphene acted as an oestrogen, suppressing by a negative feedback action gonadotrophin release in a way similar to ethinyl oestradiol. In the normal control group with an adequate steroid environment, clomiphene acted (probably at the hypothalamic level) as an oestrogen antagonist and stimulated gonadotrophin secretion. In view of our findings, it seems as if the ability of anovulatory patients to respond to clomiphene treatment by increased gonadotrophin secretion depends upon the absolute concentration of the compound in the different organs and by the quantitative relation of clomiphene to the endogenous oestrogens.

Adult↗
PubMedDate not supplied

Acidifying enemas (lactitol and lactose) vs. nonacidifying enemas (tap water) to treat acute portal-systemic encephalopathy: a double-blind, randomized clinical trial.

A double-blind, controlled trial to study the efficacy of acidifying enemas of lactitol, a new galactoside-sorbitol disaccharide, and lactose vs. nonacidifying tap-water enemas was performed in 45 episodes of acute portal-systemic encephalopathy. At the time of randomization, all patients had encephalopathy of at least Grade 2+ severity, delay in the performance of number connection tests and hyperammonemia. A sequential analysis was performed which revealed after the inclusion of the first 20 patients, a significant failure of the nonacidifying enemas as compared to the lactitol enemas (p less than 0.004). The tap-water enema group was, therefore, suspended but the rest of the study continued after rerandomization for lactose and lactitol groups. A favorable response to treatment was obtained in 19 (86%) of the patients receiving lactitol enemas and in 14 (78%) of those receiving lactose enemas. A similar significant improvement in portal-systemic encephalopathy parameters and index was observed after both treatments. Both types of acidifying enemas induced a significant pH decrease in stool (p less than 0.05). These data suggest that acidifying agents like lactose and lactitol are effective and superior to tap-water enemas for the treatment of acute nitrogenous portal-systemic encephalopathy.

Ammonia↗