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M D Torres

Publications and source records attributed to M D Torres.

34 records · Page 2Linked to original sources
PubMed1981

Immunogenetic studies of H-2 antigens of MCG 3 tumour cells.

MCG 3 is a B 10(H-2b) sarcoma induced as a solid tumour with 0.2 mg of methylcholantrene in our laboratory. The ascites form obtained was used to study the expression of H-2 antigeneic specificities in a postlabelling radioassay. H-2D.2, H-2K.33 (private specificities of H-2b) and H-2.28, H-2.35 (public specificities) were normally expressed for MCG 3 while H-2.5, H-2.29, H-2.36 (public specificities) were abnormally absent. These results were confirmed by quantitative absorption analysis using MCG 3 and positive-negative normal lymphoid cells for a particular specificity.

Animals↗
PubMed1980

Expression of foreign H-2-like antigens by a chemically-induced murine tumour (MCG4).

Alien H-2k-like antigens were found to be expressed by a methylcholanthrene induced tumour of BALB/c (H-2d) origin. H-2 specificities of the k haplotype were detected on this tumour by a variety of serological techniques, including 51Cr-release cytotoxicity, microradioassay and absorption. The antisera employed were conventional polyspecific alloantisera, typing sera with restricted specificty and monoclonal hybridoma-derived anti-H-2k antibodies. The tumour has a low expression of the private specificty 31, which characterizes Kd molecules, and does not seem to express the private specificities of Dd, Kk and Dk molecules. It appears to express predominantly alien H-2-like antigens which are very similar to but not identical with normal H-2k molecules.

Animals↗
PubMed1979

Effect of oleic acid on insulin secretion by the isolated perfused rat pancreas.

The isolated perfused rat pancreas was utilized to investigate the effect of oleic acid on insulin secretion. In the absence of glucose, a continuous infusion of oleic acid (1500 micromol/l) induced a biphasic insulin release. This effect was reduced at low extracellular calcium concentration. In the presence of oleic acid 1500 micromol/l, the insulin response to 10 mmol/l arginine occurred earlier, the total amount of insulin released in response to the amino acid being unchanged. Such an effect was not obtained when oleic acid in the medium was 750 micromol/l, but it was observed in the presence of oleic acid 1500 micromol/l when the concentration of albumin in the perfusate was increased from 2 g/100 ml to 4 g/100 ml. The insulin response to a continuous infusion of glucose (4.4 mmol/l and 16.7 mmol/l) was potentiated by the presence of oleic acid 1500 micromol/l in the perfusate. No modification of the biphasic pattern of insulin response to glucose 16.7 mmol/l was observed. These results demonstrate that high concentrations of oleic acid stimulate insulin release from the isolated perfused rat pancreas and modulate the insulin response to arginine or glucose.

Animals↗
PubMed1979

Absence of four H-2d antigenic specificites in an H-2d sarcoma.

MCG4 is a BALB/c sarcoma induced as a solid tumour with 0.2 mgs of methylcholantrene. The primary tumour was serially transplanted subcutaneously in syngeneic mice. The ascites form obtained was sued to study the expression of H-2 antigeneic specificities in a postlabelling radioassay. MCG4 did not express H-2D.4 (private specificity of H-2d haplotypes) as well as H-2.3, H-2.8 and H-2.13 (public specificities). In addition it expressed H-2.5 (a public specificity not present in H-2d cells). These results were confirmed by quantitative absorption analysis using MCG4 and positive-negative normal lymphoid cells for a particular specificity. Results are discussed with regard to the control of expression of H-2 antigens by regulatory genes.

Animals↗
PubMed1979

A syngeneic anti tumor serum recognizing a complex H-2 alloantigen.

A methylcholanthrene induced tumor of BALBc (H-2d) origin had a high rate of spontaneous regression when transplanted into syngeneic animals. The tumor induced in BALB/c mice iso-antibodies with high anti-tumor cytotoxic activity. A specificity analysis of such BALB/c anti MCG4 sera revealed that the antibodies were directed against a tumor antigen which is very similar to H-2- alloantigens (e.g. H-2.5) expressed on normal cells of certain foreign mouse strains. The sera also reacted with nine out of ten B10.W congenic strains bearing H-2wi haplotypes derived from wild mice. Whether the tumor antigen is identical with foreign H-2 antigens or only cross-reactive cannot be decided at present.

Animals↗
PubMed1978

Effect of various concentrations of calcium on arginine-induced insulin and glucagon release in vitro.

The effect of extracellular calcium concentration on the insulin and glucagon release in response to arginine from the isolated perfused rat pancreas, has been studied. All the experiments were carried out in the absence of glucose in the perfusate. Arginine 10 mM elicited a biphasic glucagon release, and a monophasic insulin response. In the presence of calcium 2.5 mM an increase of total insulin and glucagon in response to arginine were obtained. The increase in glucagon release was only detectable during the second phase, while first phase was not modified by the concentration of calcium present in the perfusate. The results of this study show that extracellular calcium concentration influences positively insulin and glucagon responses to arginine in vitro.

Animals↗
PubMedDate not supplied

Pharmacokinetics, hepatic biotransformation and biliary and urinary excretion of bromosulfophthalein (BSP) in an experimental liver disease mimicking biliary cirrhosis.

We studied the hepatic handling of bromosulfophthalein in healthy rabbits with hepatic coccidiosis 28 days after an experimental infection with sporulated oocysts of Eimeria stiedai, an experimental model of liver disease histopathologically resembling primary biliary cirrhosis in man. A pharmacokinetic study of the results was performed following a multicompartmental model with 7 transfer constants to describe the physiological disposition of the dye. The study showed that the plasma disappearance, distribution volume (Vi), hepatic biotransformation and the biliary and urinary elimination of conjugated (BSPc) and unconjugated (BSPu) bromosulfophthalein were markedly altered. Whereas Vi and urinary excretion of the dye were significantly increased, the hepatic clearance, biotransformation and biliary excretion of BSPc and BSPu were drastically reduced in infected rabbits. Satisfactory agreement was obtained between the experimental and estimated data, particularly those relating to biotransformation clearance and biliary and urinary excretion of the dye. These results demonstrate that severe liver disease in rabbits with histopathological liver alterations resembling several hepatic dysfunctions in man markedly reduce hepatic uptake, metabolism and biliary excretion of a xenobiotic such as BSP.

Animals↗
PubMedDate not supplied

[Use of thermoplasticized gutta-percha in retrograde obturation].

In 29 teeth, apicoectomies with retrograde instrumentation and retrofilling with low temperature thermoplasticized gutta-percha were performed. Nineteen of them were clinically an radiographically evaluated, showing the following average rate: successes 84.2% (16 cases), failures 10.5% (2 cases) and incomplete healing 5.2% (1 case). The observation period varied from 12 to 41 months. The use of retrograde instrumentation an retrofilling with thermoplasticized gutta-percha is suggested as a useful method in surgical procedures.

Apicoectomy↗
PubMedDate not supplied

Subcutaneous cyclosporin prevents the development of complete Freund's adjuvant-streptozotocin-induced diabetes in the rat.

The effect of subcutaneous cyclosporin administration (20 mg/kg) on the development of complete Freund's adjuvant (CFA)-streptozotocin-induced diabetes and on the induction of the so called cyclosporine diabetes like syndrome, were examined in Wistar rats. During and 5 weeks after the cyclosporin A treatment (21 days) the rats remained normoglycaemic. Three injections of 30 mg/kg streptozotocin given at weekly intervals, 24 hr after the administration of CFA, produced a persistent hyperglycaemia, an impairment of glucose tolerance and a drastic reduction in the pancreatic insulin content. The development of the diabetic state was prevented by cyclosporin treatment. The present results suggest that the cyclosporin diabetes like syndrome could not appear when cyclosporin was administered subcutaneously at the recommended doses for immunosuppression and that at such therapeutic doses, cyclosporin inhibits the development of CFA-Streptozotocin-induced diabetes in the Wistar rat.

Animals↗
PubMedDate not supplied

[Mouth diseases and acquired immunodeficiency syndrome].

The purpose of this article is to describe oral manifestations of AIDS, specially opportunistic infections, hairy leukoplakia and Kaposi's sarcoma. Fungal infections, viral infections, salivary glands disturbances and neoplasms are related. Treatment and epidemiology in Argentine are included.

Acquired Immunodeficiency Syndrome↗
PubMedDate not supplied

Prognostic value of TPS in patients with head and neck malignancies: comparison with SCC.

TPS and SCC serum levels were evaluated in 113 patients with primary tumors, 19 with relapse and 59 with no evidence of disease after radical treatment. Abnormal serum levels were found in 37% and 33% of patients with primary untreated tumors and in 53% and 59% of patients with relapse, respectively, using 100 U/L and 2.5 ng/ml as the upper limit of normality for TPS and SCC, respectively. Either tumor marker was abnormal in 57.5% of primary tumors and in 74% of patients with relapse. TPS and SCC serum levels were related to nodal involvement, with significantly higher levels in patients with nodal invasion (p < 0.02 and p 0.001, respectively). No relationship was found between tumor size, age or histological grade and SCC or TPS values. Pretreatment TPS and SCC serum levels had prognostic interest in patients with locoregional tumors, with a significantly shorter disease-free interval (DFI) in patients with abnormal values (p < 0.01 and p < 0.02, respectively). When tumor marker levels and nodes were simultaneously evaluated, a trend toward shorter DFI in patients with abnormal serum concentrations was found, with no statistical significance. By contrast, TPS and SCC were useful in prognosis in node-negative patients (p < 0.02 and p < 0.001, respectively). Likewise, using both TAAs simultaneously, it is possible to increase prognostic information. Patients with TPS and/or SCC abnormal levels had a significantly lower DFI than those patients with normal values, in both node positive and negative patients (P < 0.01). In summary, TPS and SCC are useful TAAs in patients with head and neck malignancies. Likewise, with the simultaneous use of SCC and TPS, the TAA utility in this malignancy increases in the prognosis as well as disease follow-up.

Antigens, Neoplasm↗