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T Alvarez

Publications and source records attributed to T Alvarez.

33 records · Page 2Linked to original sources
PubMed1994

Evaluation of the mutagenicity of 1-hydrazino-4-(3,5-dimethyl-1-pyrazolyl) pyridazino[4,5-b]indole.

The mutagenic potential of 1-hydrazino-4-(3,5-dimethyl-1-pyrazolyl) pyridazino [4,5-b]indole(A80a, CAS 135561-93-2), a new antihypertensive agent, was investigated in 3 test systems, according to the current EC Guidelines: Ames test with strains TA1535, TA1537, TA98 and TA100, SCE (sister chromatid exchange) test in V79 cells and micronucleus test in Swiss mice. No indications for a mutagenic potential were detected in bacteria and mice; positive results were obtained in eukaryotic cells. The potential for inducing chromosome aberrations in eukaryotic cells will be studied.

Animals↗
PubMed1994

[Adenocarcinoma of the nasal cavities and paranasal sinuses. On low-grade adenocarcinoma].

The AA. having had the opportunity to diagnose and treat one of those cases, of low degree, sitting in the nasal cavity, discuss about its classification either in the nose or in the sinuses. Their opinion is coincidental with that of other reporters regarding to the complexity and varieties of a grouping system. They propose an other one, not original at all, but having perhaps the advantage that could make easier the comprehension and the clinical orientation when dealing with these growths.

Adenocarcinoma↗
PubMed1993

Pharmacological characterization of the vasodilator effect of DF-100, a new pyridazino[4,5-b]indole, in vascular smooth muscle.

DF-100, i.e., 1-hydrazino-4-(3,5-dimethyl-1-pyrazolyl)-5H-pyridazino[4,5-b ]indole is a new pyridazino[4,5-b]indole derivative related to dihydralazine. The inhibitory effects of DF-100 were investigated on the contractions in isolated aorta and portal vein. In rat aorta, DF-100 inhibited both K(+)-induced as well as norepinephrine-induced contractions. DF-100 also caused dose-dependent relaxation of contractions produced by 80 mM K+. Moreover, DF-100 significantly inhibited the CaCl2 dose response in high-K+ depolarizing medium. DF-100 inhibited the phasic contractile response to norepinephrine and the caffeine-induced response, suggesting that this molecule affects the mobilization of Ca2+ from a membrane-bound pool. In rat portal vein, DF-100 inhibited the spontaneous rhythmic contractions. The results obtained in this study in isolated rat aorta and portal vein suggest that DF-100 has a direct vasodilating effect that could be attributed to inhibition of cellular Ca2+ influx and release from intracellular stores.

Animals↗
PubMed1992

Antihypertensive and vasodilator effect of A-80b, a new pyridazino indole derivative.

The hypotensive and antihypertensive activities of a A-80b, a newly synthesized pyridazino[4,5-b]indole derivate were investigated in anaesthetized rats. In vitro studies were also done to examine the possible mechanism of its vasodilator action. A 80b (3-15 mg/kg i.p.) showed potent and long-lasting antihypertensive activity in spontaneous hypertensive rats. In normotensive rats, A-80b (7.5-30 mg/kg i.p.) also lowered blood pressure but less than in hypertensive rats. The decrease in diastolic pressure was greater than the decrease in systolic pressure and cardiac frequency was not modified significantly. Contractile responses induced in isolated rat thoracic aorta by K+ and noradrenaline were inhibited by A-80b. In K(+)-depolarized rat aorta, A-80b showed dose-dependent inhibition of the Ca(2+)-induced contraction. Also, A-80b inhibited spontaneous contractions of rat portal vein. The vasodilator action seemed to be endothelium-independent. These results suggest that A-80b is a new chemical entity which exerts a hypotensive and antihypertensive effect, possibly attributable to vasodilator activity via interference with Ca2+ influx and probably Ca2+ mobilization from intracellular stores.

Animals↗
PubMed1991

New 5H-pyridazino[4,5-b]indole derivatives. Synthesis and studies as inhibitors of blood platelet aggregation and inotropics.

Some fused 5H-pyridazino[4,5-b]indoles (7-10), substituted in positions 1 and 4 by hydrazine and/or amino groups, have been synthesized. These new compounds present a planar topography, a dipole with an adjacent acidic proton, and a basic hydrogen-acceptor site opposite the dipole. These compounds have some resemblance to carbazeram and other pyridazino agents with cardiotonic activity. Some of the new compounds here described possess inotropic activity (Table I and II), with a complementary effect as inhibitors of platelet aggregation (Table III and IV). 1-Hydrazino-4-(3,5-dimethyl)-1-pyrazolyl-5H-pyridazino[4,5-b ]indole hydrochloride (7a.HCl) is the first compound described in the literature with activities as inhibitor of PDE-IV and as selective inhibitor of TXA2 synthetase (Table V).

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1983

Plexiform structures in malignant schwannomas after prenatal exposure to ethylnitrosourea.

75 Schwann cell tumors were induced in the offspring of Wistar rats which had been treated intraperitoneally with 15 mg/kg b.w. ethylnitrosourea on the 15th day of pregnancy. Plexiform structures characterized by poorly-developed, distorted and bizarre bundles of nerves were seen in 2 of 33 benign tumors, and in 17 of 42 malignant schwannomas. Since when seen in man similar findings are distinctive of neurofibromatosis, it is suggested that this experiment may offer a model for studying non-inherited forms of neurofibromatosis and, more particularly, the malignant changes often associated with this disease.

Animals↗
PubMed1979

Mixed Brenner and adenomatoid tumor of the testis: an ultrastructural study and histogenetic considerations.

A previously unreported association of Brenner and adenomatoid tumor found in the tunica vaginalis testis is presented. Many ultrastructural features found in mesothelial cells such as intercellular spaces, deeply indented nuclei, tonofilaments and tight desmosomes, were also shared by cells present in both neoplastic patterns. The previous histogenetic origins ascribed to testicular Brenner tumors are discussed and the evidence for their origin in the mesothelium considered.

Adult↗
PubMedDate not supplied

Comparison of different ligand densities for the manufacture of CB Hep-1 immunosorbents.

Different ligand densities of monoclonal antibody (Mab) CB.Hep-1 were studied during covalent coupling on Sepharose CL-4B for recombinant hepatitis B surface antigen (rHBsAg) immunoaffinity purification. Ligand densities of 2.2, 3.2, 4.2 and 5.2 mg Mab/ml immunosorbents, respectively, were assayed during five cycles of immunoaffinity chromatography (IAC). Adsorption capacities averaged either 3.2 mg/ml (0.57 mg rHBsAg/ml immunosorbent/5.42 mg of total purified protein) or 5.2 mg/ml (0.56 mg rHBsAg/ml immunosorbent/5.05 mg total purified protein). Immunosorbents showed ligand leakage levels below 3 ng Mab/microg rHBsAg. Antigen purity was higher than 95% in all cases. The results suggest that a ligand density (LD) of 3.2 mg Mab/ml immunosorbent should be used for immunoaffinity chromatography because no significant differences were found in the ligand densities studied (P-value=0.012), which saves 40% of CB.Hep-1 immunosorbent manufacturing cost in comparison with 5 mg Mab/ml immunosorbent, which is currently used in large-scale production.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Laminar ichthyosis].

Explore the source record for details and available documents.

Child, Preschool↗
PubMedDate not supplied

[Hydatidosis/echinococcosis in General Acha, La Pampa Province, Argentina].

Hydatidosis situation in the General Acha area (La Pampa Province) is described herein. The work comprises a retrospective compilacion of new hydatidosis human cases, the findings in seroepidemiological surveys with enzyme immuno assay (EIA) for hydatidosis in human population, and investigation on dog Echinococcus granulosus infection prevalence carried out on the basis of arecoline bromhydrate application. Sixteen human cases were detected during 1994 (incidence rate: 26.7/100,000), founding a serological prevalence of 1.3%. Studies on dog echinococosis have shown a prevalence rate of 2.3%. The epidemiological situation of hydatidosis is analyzed by comparison with values from other endemic areas. These results suggest the necessity of completing surveys in the whole provincial territory, and the implementation of educational and sanitary measures aimed to controlling this zoonosis.

Adolescent↗