PubMed Health⌕ Search

Biomedical subjects

Carlos Ramos

Publications and source records attributed to Carlos Ramos.

10 recordsLinked to original sources
PubMed2006

Acidic fibroblast growth factor decreases alpha-smooth muscle actin expression and induces apoptosis in human normal lung fibroblasts.

Fibroblast/myofibroblast expansion is critical in the pathogenesis of pulmonary fibrosis. To date, most research has focused on profibrotic mediators, whereas studies on antifibrotic factors are scanty. In this study, we explored the effects of acidic fibroblast growth factor (FGF-1) and FGF-1 plus heparin (FGF-1+H) on fibroblast growth rate, apoptosis, and myofibroblast differentiation. Heparin was used because it participates in FGF-1 signaling. Growth rate was evaluated by WST-1 colorimetric assay, DNA synthesis by [(3)H]thymidine incorporation, and apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) and cleaved caspase 3. Expression of alpha-smooth muscle actin (alpha-SMA) was examined by immunocytochemistry, flow cytometry, real-time PCR, and immunoblotting. Despite the induction of DNA synthesis, FGF-1+H significantly reduced fibroblast growth rate. This correlated with a significant increase in apoptosis, evaluated by TUNEL (41.6 +/- 1.4% vs. 12.5 +/- 0.6% from controls; P < 0.01) and cleaved caspase 3 (295 +/- 32 vs. 200 +/- 19 ng/10(6) cells from controls; P < 0.05). Double immunostaining (alpha-SMA-TUNEL) revealed that the levels of induced apoptosis were similar in fibroblasts and myofibroblasts. FGF-1+H inhibited the effect of TGF-beta1 on myofibroblast differentiation. alpha-SMA-positive cells were reduced by immunocytochemistry from 44.5 +/- 6.5% to 10.9 +/- 1.9% and by flow cytometry from 30.6 +/- 2.5% to 7.7 +/- 0.6% (P < 0.01). Also, FGF-1+H significantly inhibited the TGF-beta1 induction of alpha-SMA quantified by real-time PCR and Western blot. This decrease was associated with a 35% reduction in TGF-beta1-induced collagen gel contraction. The effect of FGF-1+H was mediated by a significant decrease of TGF-beta1-induced Smad2 phosphorylation. FGF-1 alone exhibited similar but lower effects. These findings suggest that FGF-1 can have an antifibrogenic role, inducing apoptosis of fibroblasts and inhibiting myofibroblast differentiation.

Actins↗
PubMed2005

Safety and efficacy of colistin in Acinetobacter and Pseudomonas infections: a prospective cohort study.

OBJECTIVE: To assess renal dysfunction and outcome in patients treated exclusively with colistin vs. other antibiotics. DESIGN AND SETTING: Prospective cohort study in a mixed ICU in a university-affiliated hospital. PATIENTS: 185 patients infected with Acinetobacter baumannii and Pseudomonas aeruginosa after an ICU stay longer than 48 h: 55 in the colistin group and 130 in the noncolistin group, similar in age, APACHE II, medical status, and SOFA score. MEASUREMENTS AND RESULTS: We recorded data on epidemiology and severity of illness, site of infection, renal function before and after treatment, clinical cure, and mortality. Clinical cure was defined as simultaneous normalization of central temperature (< or = 38 degrees), leukocyte count (< or = 10,000/mm3), and PaO2/FIO2 ratio (>187). Before treatment creatinine was 0.9+/-0.2 in the colistin group and 0.9+/-0.1 in the noncolistin group; after treatment the value was 1.0+/-0.3 in both groups. The most frequent infection was ventilator-associated pneumonia: 53% vs. 66% in colistin and noncolistin groups, respectively, Acinetobacter was the cause in 65% and 60% and Pseudomonas in 35% and 53%. In the noncolistin group 81% of patients were treated with carbapenems. Inadequate empirical antimicrobial treatment was more frequent in the colistin group (100% vs. 8%), but there were no differences in the frequency of clinical cure on day 6 of treatment (15% and 17%) or in mortality (29% and 24%). CONCLUSIONS: Colistin appears to be as safe and as effective as other antimicrobials for treatment of sepsis caused by Acinetobacter and Pseudomonas in critically ill patients.

APACHE↗
PubMed2004

Matrix metalloproteinases activity in COPD associated with wood smoke.

BACKGROUND: Wood smoke (WS) exposure causes COPD with respiratory alterations that are similar to those described for COPD associated with tobacco smoke (TS). The aim of the present study was to analyze the effects of WS on matrix metalloproteinase (MMP) activity and expression. DESIGN: BAL fluid and macrophages were obtained from patients exposed to WS and TS, and from control subjects. Macrophage elastolytic activity was assayed by radiolabeled elastin degradation. Gelatinolytic activity was measured by zymography in BAL fluid samples. MMP-2, MMP-9, and MMP-12 expression were analyzed by reverse transcription polymerase chain reaction in macrophages from each group. RESULTS: Macrophage elastolytic activity was increased significantly in WS and TS cells in comparison to control subjects with no differences between WS and TS samples. MMP-2 was identified in all groups as a 72-Kd band (proMMP-2), with the highest activity in the WS samples. MMP-9 was present in its latent and active forms with the highest gelatinolytic activity in the WS group. MMP-2 expression was increased in both groups as well as MMP-12 compared with the control. Two of three subjects studied in each COPD group had a significant increase in MMP-9 expression. CONCLUSION: These findings demonstrate that WS increases MMP activity and expression that might produce lung damage similar to that observed in COPD associated with TS.

Biomarkers↗
PubMed2003

Cigarette smoke exposure potentiates bleomycin-induced lung fibrosis in guinea pigs.

The role of tobacco smoking in the development and outcome of pulmonary fibrosis is uncertain. To approach the effects of cigarette smoke on bleomycin-induced lung fibrosis, we studied five groups of guinea pigs: 1) controls, 2) instilled with bleomycin (B), 3) exposed to tobacco smoke for 6 wk (TS), 4) bleomycin instillation plus tobacco smoke exposure for 6 wk (B+TS), and 5) tobacco smoke exposure for 6 wk and bleomycin after smoking (TS/B). Guinea pigs receiving bleomycin and tobacco smoke exposure exhibited higher fibrotic lesions including a significant increase in the number of positive alpha-smooth muscle actin cells compared with bleomycin alone (B+TS, 3.4 +/- 1.2%; TS/B, 3.7 +/- 1.5%; B, 2.3 +/- 1.5%; P < 0.01). However, only the TS/B group reached a significant increase in lung collagen compared with the bleomycin group (TS/B, 3.5 +/- 0.7; B +/- TS, 2.9 +/- 0.4; B, 2.4 +/- 0.2 mg hydroxyproline/lung; P < 0.01). Bronchoalveolar lavage (BAL) from TS/B showed an increased number of eosinophils and higher levels of IL-4 and tissue inhibitor of metalloproteinase-2 (P < 0.01 for all comparisons) and induced a significant increase in fibroblast proliferation (P < 0.05). Importantly, smoke exposure alone induced an increase in BAL neutrophils, matrix metalloproteinase-9, and fibroblast proliferation compared with controls, suggesting that tobacco smoke creates a profibrotic milieu that may contribute to the increased bleomycin-induced fibrosis.

Actins↗
PubMed2002

Linkage of a geographical information system with the gleams model to assess nitrate leaching in agricultural areas.

The GLEAMS (Groundwater Loading Effects of Agricultural Management Systems, Version 2.10) model was linked with a Geographical Information System (GIS) to evaluate the risk of nitrate pollution in an area of 230 km2 near Valencia (Spain). Under Mediterranean conditions, GLEAMS was calibrated and validated using results from field experiments on citrus orchards and vegetables grown in that area. A graphical user interface (GUI) was implemented in the GIS-model system to allow a non-specialist to run the model, and to represent simulation results as a thematic map. In order to execute the GLEAMS model, data must be grouped in five basic layers: four layers correspond to the base maps (soils, climate, land use, NO3 content in irrigation water), and the fifth layer corresponds to agricultural management practices, introduced in the system interacting to the GUI. To illustrate system capabilities. two rotations with crops in the vegetable area (potato/lettuce/onion/cauliflower, and artichoke/artichoke in 2 years rotation each), and orange trees in the citrus area, were simulated to determine the N leached in the study area. Pollution risk maps show that vegetable crops and areas irrigated with groundwater have the highest potential risk of groundwater nitrate pollution. Further analysis identified potato and artichoke (in the first year) to be the crops with the higher risk.

Agriculture↗
PubMedDate not supplied

Role of retinal detachment subretinal fluid on extracellular matrix metabolism.

PURPOSE: To examine the in vitro effects of subretinal fluid (SRF) from patients with retinal detachment on extracellular matrix turnover. METHODS: Matrix metalloproteinase (MMP) activity was explored by radiolabeled substrate degradation and zymography. Human lung fibroblasts were used to analyze SRF effects on collagen synthesis and cell proliferation. Transforming growth factor-beta(2) (TGF-beta(2)) concentration was determined in SRF samples by a quantitative sandwich enzyme immunoassay. RESULTS: MMP-2 and MMP-9 gelatinolytic activity was observed in all SRF samples. Collagenase activity was not detected in SRF from patients with holes and recurrent retinal detachment. All SRF samples stimulated fibroblast proliferation and collagen synthesis but SRF samples from recurrent retinal detachment patients with previous retinal tears had the largest effect with the largest TGF-beta(2) concentration. CONCLUSIONS: The gelatinolytic activity found in all SRF samples might be associated with the retinal detachment process. Low collagenase activity with an increase in collagen synthesis could indicate a risk factor to the development of proliferative vitreoretinopathy.

Adolescent↗