PubMed Health⌕ Search

Biomedical subjects

L Terán

Publications and source records attributed to L Terán.

13 recordsLinked to original sources
PubMed1998

72-kD (MMP-2) and 92-kD (MMP-9) type IV collagenase production and activity in different histologic types of lung cancer cells.

In this study we examined the production of gelatinases A and B (MMP-2 and MMP-9), and their natural inhibitors TIMP-1 and TIMP-2 in cell lines derived from different histologic types of lung cancer. Gelatinolytic activity was measured by zymography and radiolabeled gelatin degradation. Immunocytochemistry and Western blot analysis were performed to corroborate the presence of immunoreactive MMP-2, MMP-9, TIMP-1 and TIMP-2 proteins. The highest gelatinolytic activity was identified in the cell extracts from a small-cell carcinoma cell line. MMP-9 was observed in all samples as a proenzyme, while MMP-2 was present as zymogen in the squamous-cell and in the small-cell carcinomas, and in its active form in one squamous-cell carcinoma cell line. TIMPs were also present in the neoplastic lung cell lines. TIMP-1 was observed in the media of all cells as a 21-kD band, and as TIMP-1 polymers with the exception of the small-cell carcinoma samples. TIMP-2 was found as higher-order molecular immunoreactive complexes that may correspond to proMMP-2/TIMP-2 complexes. These results demonstrate that lung neoplastic cells produce both MMP-2 and MMP-9 and their inhibitors, with the small-cell carcinoma cell extracts showing the highest enzymatic activity. This gelatinolytic activity fits well with the clinical metastatic behavior of this type of lung cancer.

Blotting, Western↗
PubMed1995

Collagen metabolism in human aqueous humor from primary open-angle glaucoma. Decreased degradation and increased biosynthesis play a role in its pathogenesis.

OBJECTIVE: To explore the influence of aqueous humor from patients with glaucoma on collagen turnover. METHODS: The aqueous humor of patients with primary open-angle glaucoma (POAG), chronic angle-closure glaucoma, congenital glaucoma, neovascular glaucoma, and senile cataract (control group) was analyzed for its capacity to induce fibroblast proliferation, collagen synthesis, collagenolytic activity, and production of tissue inhibitor of metalloproteinase-1. All data were analyzed using the Mann-Whitney U test. RESULTS: Aqueous humor derived from patients with POAG induced a significant decrease of functional collagenase activity (mean +/- SE, 9.12 +/- 1.33 microgram of degraded collagen per milligram of incubated protein vs 20.94 +/- 4.14 micrograms from the control group, P < .05). The enzymatic activity in the other types of glaucoma was similar to that of controls. The POAG samples had a significantly higher concentration of tissue inhibitor of metalloproteinase-1 (mean +/- SE, 3.11 +/- 0.58 vs 0.91 +/- 0.13 micrograms/mL from controls; P < .05). The amount of immunoreactive tissue inhibitor of metalloproteinase-1 found in the other three groups was not significantly different from the control. Aqueous humor stimulated fibroblast proliferation in all cases, but significant differences were not observed between the POAG samples (mean +/- SE, 20,285 +/- 4642 cpm/mg of incubated protein) and the control group samples (26,550 +/- 3688 cpm/mg of incubated protein). Primary open-angle glaucoma fluids increased collagen synthesis significantly compared with the control group (mean +/- SD, 3352 +/- 630 vs 985 +/- 285, P < .05), and the other groups. CONCLUSIONS: An increase of collagen synthesis and a decrease of collagen degradation may contribute to an excessive deposit of collagen with loss of the trabecular cells during the development of POAG, and aqueous humor must be considered as a microenvironment that affects the metabolism or function of the trabecular meshwork or both.

Adult↗
PubMed1995

Influence on collagen metabolism of vitreous from eyes with proliferative vitreoretinopathy.

PURPOSE: Proliferative vitreoretinopathy (PVR) is characterized by cell proliferation and membrane formation on the vitreoretinal cavity of the eye. The membranes are composed of extracellular matrix, mainly collagen type I. To explore the possible mechanisms involved in PVR membrane formation, the authors analyzed the role of vitreous humor on collagen turnover. METHODS: The authors studied vitreous samples from ten patients with PVR and from five donor eyes (keratoplasty) as the control group. Human lung fibroblasts were used to study the influence of vitreous on collagen synthesis and cell proliferation. Neutralizing antibodies against transforming growth factor-beta 2 (TGF-beta 2) were used to inhibit the fibroblast collagen synthesis induced by the vitreous samples. Collagenolytic activity was analyzed in vitreous fluid using 3H-labeled collagen. RESULTS: The authors found that samples obtained from patients with PVR significantly increased collagen synthesis (2979 +/- 963.26 versus 800 +/- 232 dpm of 3H-proline incorporated per milligram of vitreous-incubated protein; P < 0.00043), without affecting fibroblast replication. The collagen synthesis induced by the vitreous samples was inhibited by anti-TGF-beta 2 antibodies in both groups (0 and 481 +/- 59 dpm of 3H-proline incorporated per milligram of vitreous-incubated protein for control and PVR samples, respectively). Collagenolytic activity was considerably lower in vitreous derived from PVR samples compared with the control group (19.9 +/- 20.3 versus 234.1 +/- 19.1 micrograms of degraded collagen per milligram of vitreous-incubated protein; P < 0.0032). CONCLUSION: These results suggest that a combined mechanism, including an increase of collagen synthesis mediated at least in part by TGF-beta 2 and a decrease of collagen degradation, may contribute to the exaggerated deposition of collagen observed in PVR membranes, and that vitreous should be considered as a part of the microenvironment that is participating actively in the pathogenesis of this vitreoretinal disorder.

Cell Division↗
PubMed1987

Increase of HLA-DR7 in pigeon breeder's lung in a Mexican population.

The phenotypes of the major histocompatibility complex, loci A, B, C, and DR, were studied in 48 patients with hypersensitivity pneumonitis induced by avian antigen (pigeon breeder's lung) and the results were compared to those obtained from 200 normal subjects of similar ethnic background. Furthermore, we analyzed the delta values of the observed and expected frequencies in the deduced haplotypes of the affected population. Our results showed a significant increase of the antigen HLA-DR7 (corrected P less than 0.001) in patients with pigeon breeder's lung and an equally important difference in the delta values of the haplotypes A1-B8, A25-B14, B35-DR4, and B4-DR5. In addition, the phenotypes of locus DQ were analyzed in 21 patients and 20 controls and no apparent differences were observed. These results suggest that a multifactorial genetic susceptibility associated at least in part with the major histocompatibility complex plays in important role in the development of this disease.

Adult↗
PubMed1979

HLA frequencies in a Mexican Mestizo population.

The aim of the present study was to reevaluate the distribution of HLA antigens in Mexican Mestizos since, in our previous report, very few specificities were explored for this population. The Mestizos are primarly a mixture of Caucasians (Spaniards) and Mexican Indians and account at the present time for about 95% of the total Mexican population. A and B antigens were typed on isolated cells using a microlymphocytotoxicity technique. Antigen, gene and haplotype frequencies were calculated including the significance for delta values. The results clearly showed that the HLA distribution differs from other ethnic groups and the predominant antigens are A2, A9, B5, Bw35 and B40, but the general pattern clearly shows the participation in genetical composition of Spanish and Mexican Indian backgrounds. The most frequent haplotypes were A2-B5, A9-Bw35, A9-B40 and A2-B40, which are also the most common in some Mongoloid populations.

Alleles↗
PubMedDate not supplied

Circulating autoantibodies in patients with pigeon breeder's disease.

Sera from 19 patients with hypersensitivity pneumonitis induced by avian antigens were studied in order to determine the presence of circulating autoantibodies. IgM and IgG rheumatoid factors were positive in 68% and 100% of the cases respectively. IgM-rheumatoid factor was detected with at least two methods, showing titers between 1:20 and 1:1280 by the latex agglutination test and between 140 and 579 IU/ml by nephelometry test. The IgG rheumatoid factor was studied by the indirect immunofluorescence technique, showing positive determinations in all of our hypersensitivity pneumonitis patients. Titers of these autoantibodies ranged from 1:80 to 1:640. In addition, we studied the presence of antinuclear, anti-nDNA, anti-mitochondrial, and anti-smooth muscle antibodies by the immunofluorescence test using HEp-2 cells, mouse kidney, and Crithidia luciliae targets. Sera from all of our hypersensitivity pneumonitis patients have negative results of autoantibodies to these antigens. Negative results of autoantibodies to the nRNP, Sm, SS-A(Ro) and SS-B(La) nuclear antigens by counterimmuno-electrophoresis and double immunodiffusion techniques were also obtained. As controls we studied 14 healthy individuals and 8 subjects exposed to avian antigens but without hypersensitivity pneumonitis symptoms and no positive determinations for rheumatoid factor, antinuclear antibodies, as well as to anti-mitochondrial and anti-smooth muscle antibodies, were found. These findings support that different immune abnormalities are present in patients with hypersensitivity pneumonitis induced by avian antigens. One of these immune alterations or a combination of them may promote or facilitate the acute interstitial lung injury and/or perpetuate a chronic inflammatory process.

Adult↗
PubMedDate not supplied

[Effect of pregnancy and the puerperium on the development of extrinsic allergic alveolitis].

Extrinsic Allergic Alveolitis (EAA) is a disease characterized by an exaggerated immune response to inhaled organic dusts that can result in alveolar, and occasionally bronchiolar, damage. This damage can disappear completely with the elimination of the antigen and/or treatment with anti-inflammatory agents. Nonetheless, an important group of these patients do not improve; the inflammatory reaction persists. With time, this results in the deposit of abnormal connective, tissue with respect to its quantity and quality, in the pulmonary interstitium destroying the normal parenchymal architecture and making gas exchange impossible. The most common cause of this disease is inhalation of pigeon antigen with a 5:1 predominance in women. Pregnancy has been considered as a case of allotransplantation that produces in the mother a relative hyporeactive condition. In modifying the immune response to the fetus, it is also modified to other foreign antigens. In this work, we studied 80 cases of EAA, 67 females and 13 males. Of the 67 women, 11 (17.1%) presented with the disease after delivery. Symptoms began from 5 days to 7 months after delivery. Eight of the 11 women had been in contact with the antigen before the beginning of the pregnancy without showing symptoms until after delivery. In 4 cases, there had been contact with the antigen in other pregnancies, without symptoms. EAA is a disease involving the immune system in which changes can be seen in its development during pregnancy, as is also seen in other immune diseases, such as Lupus Erythematosus, Rheumatoid Arthritis and other connective tissue diseases. During pregnancy, the mother becomes tolerant. There is a decrease in non-self recognition.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗