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A Gutierrez

Publications and source records attributed to A Gutierrez.

At least 127 records · Page 7Linked to original sources

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Argentina↗

Microevolutionary analysis of the nematode genus Pristionchus suggests a recent evolution of redundant developmental mechanisms during vulva formation.

To identify the mechanisms by which molecular variation is introduced into developmental systems, microevolutionary approaches to evolutionary developmental biology have to be taken. Here, we describe the molecular and developmental characterization of laboratory strains of the nematode genus Pristionchus, which lays a foundation for a microevolutionary analysis of vulva development. We describe 13 laboratory strains of the Pristionchus genus that are derived from natural isolates from around the world. Mating experiments and ITS sequence analysis indicated that these 13 strains represent four different species: the gonochoristic species P. Iheritieriand three hermaphroditic species, P. pacificus, P. maupasi, and an as yet undescribed species Pristionchus sp., respectively. P. pacificus is represented by five different strains isolated from California, Washington, Hawaii, Ontario, and Poland. Developmental differences during vulva formation are observed between strains from different species but also between strains of P. pacificus, like the strains from California and Poland. In particular, redundant developmental mechanisms present during vulva formation in P. pacificus var. California are absent in other strains. Amplified restriction fragment length polymorphism (AFLP) analyses of the P. pacificus strains revealed that the American strains are highly polymorphic. In contrast, the developmentally distinct strain from Poland is identical to the Californian strain, suggesting that the developmental differences rely on a small number of changes in developmental control genes rather than the accumulation of changes at multiple loci.

Animals↗

Estrogen receptor profiles: changes in mouse and rat mammary tumors by treatment with selective estrogen receptor modifiers.

OBJECTIVE: The aim of this work was to analyze the effect of estradiol (E(2)), medroxyprogesterone and the two selective estrogen receptor modulators (SERMs) (tamoxifen (Tam) and raloxifene (Ral)) on the estrogen receptor (ER) conformers profile performed by size exclusion HPLC in relation to hormone dependence of mammary tumors. MATERIALS AND METHODS: Two types of mammary tumors were studied: tumors transplanted in BALB/c mice that are medroxyprogesterone acetate (MPA)-dependent for growth, and tumors induced in Sprague-Dawley rats by intraperitoneal injection of N-nitroso-N-methylurea (NMU). Tumors from mice treated with MPA, E(2), Tam or Ral and NMU-treated rats were analyzed and compared to that of control. RESULTS: The tumor conformer profiles were as follows: control and MPA-treated mice showed only one peak (oligomeric form); E(2)-treated mice also showed only one peak (dimer); Tam-treated mice showed one peak corresponding to a possible proteolytic fragment, and Ral-treated mice showed two peaks (oligomeric and a possible proteolytic fragment). On the other hand, NMU-induced mammary tumors from rats showed three peaks (oligomeric, monomeric and proteolytic). CONCLUSION: Our findings may indicate that SERMs affect the aggregation state of ER and thereby its ability to modulate genomic transcription mechanisms related to growth rate.

Animals↗

Serum CEA, CA125, and SCC antigens and tumor recurrence in resectable non-small cell lung cancer.

Carcinoembryonic antigen (CEA), squamous cell carcinoma antigen (SCC), and CA125 were determined pre- and postoperatively in non-small cell lung cancer patients (NSCLC) to assess the relationship between serum levels and postoperative recurrent disease. Ninety-five patients who underwent curative surgical resection were included (TNM stages I, II, IIIa). CEA and CA125 were determined by solid-phase enzyme-immunoassay, SCC by radio-immunoassay. Tumor relapse was detected in 41 patients (43%): 16 (39%) with locoregional disease and 25 (61%) with disseminated disease. The overall 36-month disease-free survival rate was 42%. The sensitivity for recurrence was 58% for CEA, 53.6% for CA125, and 51.2% for SCC; 87.8% of patients showed at least one elevated marker. The sensitivity of CEA and CA125 increased significantly in patients with preoperative serum concentrations above the cut-off: 86.6% versus 42.3% (p < 0.01), and 93% versus 18% (p < 0.01), respectively. Preoperative CA125 above 15 U/ml identified a high-risk group of patients: a lower 36-month disease-free survival rate (0% versus 56%) (p < 0.001), a 3.02-fold higher risk of recurrence (p < 0.05), and a 6.22-fold higher risk of disseminated failure (p < 0.001). The identification of CEA and CA125 producer-tumors, based on preoperative serum values, enhances the clinical performance of a postoperative surveillance program in surgically treated NSCLC. Preoperative serum CA125 is a prognostic factor to identify patients at high risk of postoperative tumor recurrence.

Aged↗

[Hepatic hemorrhagic infarction in eclampsia and HELLP Syndrome associated with the antiphospholipid syndrome].

A 33 year-old woman developed eclampsia with HELLP syndrome. Laboratory results revealed lupus anticoagulant and anticardiolipin antibodies. Imaging tests showed liver and spleen infarctions. The patients was given enoxaparin and supportive care and there was a good evolution. We discuss some aspects about liver infarction and its association with toxemia of pregnancy and the antiphospholipid syndrome.

Adult↗