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Biomedical subjects

C A Martínez

Publications and source records attributed to C A Martínez.

10 recordsLinked to original sources

Photoprotective activity of Buddleja scordioides.

The purpose of this study was to determine the photoprotective properties of the methanolic extract of Buddleja scordioides, as well as verbascoside and linarin which were isolated from this extract, and linarin acetate prepared in the laboratory. The photoprotective effect of substances against UV-B induced cellular death was evaluated by challenge experiments using Escherichia coli. Verbascoside and linarin acetate showed the highest protection. The sun protection factor (SPF) of the methanolic extract, linarin, linarin acetate, and verbascoside was evaluated by guinea pig bioassays. Verbascoside showed the largest SPF measurement.

Animals↗

The association of Aiolos transcription factor and Bcl-xL is involved in the control of apoptosis.

We have analyzed the mechanism implicated in the control of the anti-apoptotic role of Bcl-xL. We show that IL-4 deprivation induces apoptosis, but does not modulate Bcl-xL expression. Because Bcl-xL does not promote cell survival in the absence of IL-4, we investigate the mechanism by which Bcl-xL was unable to inhibit apoptosis. Using yeast two-hybrid system, coimmunoprecipitation, and indirect immunofluorescence techniques, we found that Bcl-xL interacts with the transcription factor Aiolos in IL-4-stimulated cells, increasing upon IL-4 deprivation. IL-4 does not promote translocation of Aiolos or Bcl-xL, but induces tyrosine phosphorylation of Aiolos, which is required for dissociation from Bcl-xL. Transfection experiments confirm that cells overexpressing Bcl-xL are able to prevent apoptosis in the absence of IL-4. On the contrary, cells that overexpress Bcl-xL and Aiolos are unable to block apoptosis in the absence of IL-4. We propose a model for the regulation of the Bcl-xL anti-apoptotic role via Aiolos.

Animals↗

Apaf-1 localization is modulated indirectly by Bcl-2 expression.

Apoptotic protease activating factor-1 (Apaf-1) is an adaptor molecule essential for caspase-9 activation. Subcellular analysis of Apaf-1 in NIH-3T3 fibroblasts and the immature murine B cell lymphoma WEHI-231 indicates that Apaf-1 is localized in the Golgi apparatus and cytoplasm. Bcl-2 overexpression in WEHI-231 cells disrupts Apaf-1 localization in Golgi, causing a perinuclear Apaf-1 redistribution. Bcl-2 overexpression in NIH-3T3 fibroblasts however does not cause similar Apaf-1 redistribution, suggesting that cell type factors are involved in the redistribution process. The ability of Bcl-2 to modify Apaf-1 subcellular localization is not explained by direct interaction between Apaf-1 and Bcl-2. These data may help to clarify the anti-apoptotic Bcl-2 function.

3T3 Cells↗

[Overweight and obesity in children and adolescents of Corrients city. Relationship with cardiovascular risk factors ].

UNLABELLED: The prevalence of children's obesity is increasing all over the world. It has been related to an increment of all morbimortality causes in the mature age. To determine the prevalence of obesity and other cardiovascular risk factors in adolescence, and correlate them with each other, we designed a cross-sectional study. A survey was applied to 2115 secondary school students, 1212 (57.3%) females and 903 (42.7%) males; blood pressure (BP) and cholesterol level were measured. Mean age: 14.8 +/- 1.6.: Body Mass Index (BMI): 20.6 +/- 3.1, 1838 (86.9%) normal, 230 (10.9%) where overweight and 47 (2.2%) obese, higher in males (OR = 1.46; IC = 1.12-1.91; p = 0.03). Weekly physical activity: 3.9 +/- 2.9 hs. higher in males (p < 0.001). Sedentarism daily hours: 3.2 +/- 1.9. ANTECEDENTS: maternal obesity 282 (13.3%), paternal 311 (14.7%) and in both 116 (6.6%). Regular consumption of fatty foods: 1711 (80.9%). SBP: 107.8 +/- 13.6; DBP: 66.9 +/- 11.5; MBP: 80.5 +/- 10.1. We found hypertension in 64 (3%) prevalent in males (p = 0.002). Cholesterol: 161.9 +/- 29.2; desirable 1283 (60.7%); normal high 628 (29.5%) and high 208 (9.8%). BMI and MBP correlation was: r = 0.25; r2 = 0.06; CI 95%: 0.02-0.11; b coefficient 0.83. We found a positive correlation of BMI with MBP (0.83 mm Hg increment for each point of BMI increment). We found significant association between parental obesity and alcohol consumption and BMI increment. We did not find any association with dietary habits, physical activity or sedentarism.

Adolescent↗

[Epidemiologic evaluation of the diagnosis and treatment of extrauterine pregnancy at the ABC Hospital].

The objective of this study was to determine the frequency, risk factors, treatment and morbility of the ectopic pregnancy (EP) at the ABC Hospital. EP cases occurring between January 1992 and May 1995 were studied retrospectively analyzing the next variables: Number of live births and EP's, the patients age, obstetric history, previous EP, sterility, previous pelvic surgeries, gestational age at diagnosis, treatment and complications. The results showed that the frequency of EP was 2.06% There was a positive correlation between EP and infertility, nuliparity, and previous tubal surgery secondary to EP. We concluded that even though EP tends to be diagnosed and treated in early stages, the majority of the surgical procedures lower patients fertility.

Female↗

Paclitaxel in platinum-resistant ovarian cancer patients. Argentine Multicenter Taxol Group.

Paclitaxel (Taxol; Bristol-Myers Squibb Company; Princeton, NJ) is an antineoplastic agent that inhibits microtubular function and has shown efficacy in several solid tumors, mainly ovarian tumors, in which 20% to 40% response rates in previously treated patients were observed. We conducted a study to assess survival, response rate, and toxicity associated with paclitaxel treatment in patients with advanced ovarian cancer resistant to platinum therapy. Between September 1994 and November 1996, 38 patients were admitted for study and 37 were evaluable. All had disease progression or relapse within 1 year of receiving platinum-containing first-line chemotherapy. Mean age was 59 years (range, 30 to 75 years), all had bulky disease, and 18 showed increased carbohydrate antigen-125 at admission. They were treated every 3 weeks with paclitaxel 175 mg/m2 as a 3-hour infusion, preceded by standard premedication. Response rate was 51.3%, with a median response duration of 10.0 months and a median survival rate of 16.8 months. Mild to moderate hematologic toxicity was observed with only one episode of grade 4 neutropenia, without fever. Gastrointestinal toxicity was moderate and peripheral neuropathy was mild, except for two patients who had concomitant pathologies or previous treatment, which might have caused some neuropathy. We concluded that paclitaxel given as a 3-hour infusion was easily administered for ambulatory treatment, with mild to moderate toxicity and promising results based on rate and duration of response as well as survival.

Adult↗

Differential expression of ras protooncogenes during in vitro differentiation of human erythroleukemia cells.

We have compared the expression of the ras protooncogene family (H-, K-, and N-ras) in leukemia cell differentiation utilizing as a model K562 and HEL erythroleukemia cells treated either with 1-beta-arabinofuranosylcytosine or 12-O-tetradecanoylphorbol-13-acetate (TPA). 1-beta-D-Arabinofuranosylcytosine induced terminal erythroid differentiation of K562 cells, while TPA induced myeloid differentiation of K562 and HEL cells, resulting in myelomonocytic-like cells expressing macrophagic and megakaryocytic markers. H-ras mRNA levels showed a dramatic decrease in K562 cells subjected to erythroid and myelomonocytic differentiation. The same result was found at the protein level for p21H-ras. Expression of K-ras and N-ras in K562 cells also decreased with differentiation, although significant mRNA levels remained despite cessation of cell proliferation. The decrease in K-ras expression was greater for TPA-treated cells than for 1-beta-arabinofuranosylcytosine-treated cells. TPA-induced myelomonocytic differentiation in HEL cells also resulted in a dramatic down-regulation of H-ras mRNA levels. Thus, by using a leukemia cell line able to differentiate along two different lineages, our results reveal a lineage-specific modulation of ras gene family expression.

Cell Differentiation↗

[Primary lymphoma of the small bowel and malabsorption].

Between 1974 and 1984 we saw 69 patients with lymphoma that involved the gastrointestinal tract. In ten patients the lymphoma compromised the small bowel and were associated to malabsorption. Seven patients fulfilled the criteria to be considered as primary small bowel lymphoma. We presumed the intestinal origin in the other 3 patients, but it was impossible to confirm it. The peroral small bowel biopsy showed histological findings compatible with celiac disease in 7 patients. Other particular histological signs were patchy alterations, inconstant epithelial pseudo-stratification and ulcerations. In 2 cases we found findings that suggested the diagnosis of lymphoma. In 50% of patients we found unspecific malabsorption signs in the small bowel radiology. We found giant ulcers and stenosis too. The gluten-free diet or the steroid therapies resulted in temporary or inconstant improvement. The laparotomy was the most effective diagnostic approach. It was performed electively in 6 patients and in 1 because of a small bowel perforation. The primary small bowel lymphoma is an entity of difficult diagnosis. The most important trouble is to differentiate it with celiac disease.

Adult↗