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Biomedical subjects

M Romero

Publications and source records attributed to M Romero.

At least 145 records · Page 8Linked to original sources
PubMed1992

[Follow-up study after percutaneous mitral valvuloplasty. The COR-PAL experience].

Mitral balloon valvulotomy has proven to be an effective method for the treatment of patients with mitral stenosis. Although several factors determining an optimal immediate result have been described, there is few information regarding the longterm follow-up as well as factors influencing late success after the procedure. In this article, we analyzed our series of 311 patients treated by mitral balloon valvulotomy who were clinically followed between 3 months and 5 years (mean 23 +/- 11 months). At least, one echo-Doppler follow-up study was obtained in 260 patients, 20 +/- 10 months after. Hemodynamic re-evaluations were performed in 63 patients after 20 +/- 11 months. Late success was defined as the patient being in functional class I-II and free of major events (death, restenosis or valve surgery). Restenosis was defined as the loss of 50% of initial gain in terms of valve area, confirmed always hemodynamically. Major events during follow-up period occurred in 19 patients (10 deaths, 8 restenosis and 11 mitral valve surgery). We performed a multivariate study using the Cox-regression model. In the analysis, all variables with or near statistic significance in the univariate analysis (Mantel-Haezel) were included. The only significant independent predictors of late success were the presence of sinus rhythm (p < 0.04) and the absence of calcium at the valve (p < 0.001). In conclusion, the best results 5 years after mitral balloon valvulotomy are observed in patients with non calcified valve and sinus rhythm.

Adult↗
PubMed1991

Immediate and follow-up results of transluminal balloon dilation for discrete subaortic stenosis.

This study presents the findings in 33 patients with discrete subaortic stenosis who were treated by percutaneous balloon dilation and were followed up for 2 months to 6.2 years (mean 34 +/- 21 months). The mean age was 13 +/- 11 years; 10 (30%) were female and 23 (70%) male. Associated malformations were observed in nine patients (27%). All patients underwent noninvasive studies and cardiac catheterization. The mean value to membrane distance was 4.5 +/- 2 mm/m2. After balloon dilation, the pressure gradient from the left ventricle to the aorta decreased from 68 +/- 30 to 20 +/- 13 mm Hg (p less than 0.00001); there were no significant changes in the degree of aortic regurgitation. A fluttering and widely mobile remaining membrane was clearly visualized after dilation. Better immediate results were obtained in patients with a smaller baseline gradient, a larger aortic anulus and a longer valve to membrane distance. Serial follow-up echographic studies were available in 30 patients, and 18 hemodynamic reevaluations were performed in 13 patients. However, seven patients who demonstrated restenosis underwent redilation at a mean of 29 +/- 17 months after the first dilation. Redilation in six of the seven patients obtained benefits similar to those observed at the first dilation. Only one patient with unsuccessful redilation required surgery. The mean value of the last explored residual gradient (on hemodynamic or Doppler study) in the remaining 32 patients was 21 +/- 10 mm Hg. No significant changes were observed in the angiographic evolution of aortic regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

Loss of heterozygosity of p53 gene and p53 protein expression in human colorectal carcinomas.

The p53 gene is a tumor suppressor gene located on chromosome 17p. Deletions of this chromosome and point mutations of p53 have been implicated in the development of colonic neoplasms. We have analyzed the loss of heterozygosity of the human p53 tumor suppressor gene in 40 cases of colorectal carcinoma using two restriction fragment length polymorphisms detected by BglII and AccII restriction enzymes. p53 gene product expression was studied immunohistochemically in 64 colorectal carcinomas, 18 adenomas, and 40 normal colonic mucosae using an anti-human p53 monoclonal antibody (Pab 1801) and the avidin-biotin-peroxidase complex technique. Twelve of the 40 patients (30%) were polymorphic for the p53 gene. In ten of these informative patients (83%), the tumor samples showed the loss of one allele when compared with normal colorectal samples of the same patient. One of the homozygous patients showed a loss of both p53 alleles. p53 immunostaining was observed in 43 of 64 carcinomas (67%) but only in two adenomas (11%). These two positive adenomas showed areas of carcinoma in situ. The normal mucosa was always negative. No relation could be found between p53 immunostaining and the degree of differentiation, the extension of the tumor, or the Ki-67 proliferative index. Mucinous carcinomas and right-side carcinomas were less p53 immunoreactive (25% and 52%, respectively) than the usual adenocarcinomas (73%) and distal tumors (72%). These findings suggest that p53 may be a target of chromosome 17 deletions and that this gene may play a role in the malignant transformation of adenomas. BglII and AccII restriction fragment length polymorphism analysis of the p53 gene may be a useful and direct technique to detect allelic loss of this gene in tumors.

Adenocarcinoma↗
PubMed1991

IL-4 inhibits IL-2 synthesis and IL-2-induced up-regulation of IL-2R alpha but not IL-2R beta chain in CD4+ human T cells.

There is growing evidence to suggest a regulatory role of IL-4 in the immune system affecting both proliferation and lymphokine production. In the present work we have analyzed the effect of IL-4 on IL-2 and IFN-gamma synthesis by stimulating CD4+ human T cells (+10% accessory cells) with Con A in the presence of several doses (1 to 100 U/ml) of human rIL-4. The results showed an impaired IL-2 and IFN-gamma synthesis in the presence of IL-4. This inhibition was dose dependent and was evident only when IL-4 was added in the first 2 h of culture. Moreover, the external addition of IL-2 did not revert the inhibitory effect of IL-4 on IL-2 and IFN-gamma synthesis induced by Con A. We have also analyzed the effect of IL-4 on the expression of both alpha- and beta-chains of the IL-2R. Although the expression of IL-2R alpha mRNA was not modified after 6 h in culture in the presence of IL-4, a decrease was observed at 24 and 48 h. The addition of rIL-2 showed that the inhibition in IL-2R alpha expression could be explained by an impairment in the up-regulatory signal transmitted through the IL-2R. In addition to this, IL-4 did not modify the IL-2R beta mRNA expression at 6 and 24 h although a decreased expression was observed at 48 h which could be explained by the defective IL-2 production. The differential effect of IL-4 on the up-regulatory effect of IL-2 in the expression of IL-2R alpha and IL-2R beta suggest the existence of different regulatory mechanisms acting on the expression of both chains.

CD4-Positive T-Lymphocytes↗
PubMed1991

Stimulation through the TCR/CD3 complex up-regulates the CD2 surface expression on human T lymphocytes.

Despite the well known interrelationship between the CD2- and CD3-mediated signal transduction pathways, it is not well established whether the CD2 surface expression can be regulated by triggering of TCR/CD3 complex. In this study we show that the stimulation of human PBMC with the Cris-7 (CD3) mAb, both in soluble and particulate form, results in hyperexpression of the CD2 surface Ag, as assessed by immunofluorescence and semi-quantitative immunoprecipitation assays. Similar effects on CD2 surface expression were obtained when different CD3 mAb (OKT3, RW2-8C8 and Leu-4) were tested. The CD3-mediated CD2 up-regulation was suppressed by cycloheximide and actinomycin D, indicating that it requires de novo protein and RNA synthesis. In agreement with this, increased CD2 RNA levels were observed after 3 h of stimulation, reaching a plateau at 24 h that was maintained for 72 h. The CD2 up-regulation was concomitant to other CD3-induced activation-related events such as induction of surface CD25 and CD71 and high RNA levels for c-myc, IL-2R alpha- and beta-chains, CD71, and IFN-gamma. CD2 up-regulation appeared to be elicited by a protein kinase C-dependent mechanism because it was abrogated by staurosporine, a potent protein kinase C inhibitor. Moreover, IL-2-dependent events may also help in enhancing CD2 hyper-expression because it was only partially inhibitable by cyclosporine, dexamethasone, or Mar-108 (CD25) mAb. In conclusion, our data suggest that CD2 up-regulation can be a relevant event in T cell activation triggered by the physiologic engagement of the TCR/CD3 complex.

Antibodies, Monoclonal↗
PubMed1991

Balloon valvuloplasty for mild mitral stenosis.

Of a total number of 288 patients with mitral stenosis treated by percutaneous balloon valvuloplasty, 21 patients had a basal mitral area equal to or greater than 1.5 cm2, as measured hemodynamically. The immediate hemodynamic results of this particular group of patients with mild mitral stenosis are described, as well as the clinical and echo doppler findings at follow-up (22 +/- 12 mo). Patients with mild mitral stenosis (group I) had more pliable valves (p less than 0.01), as assessed by echo, and higher incidence of sinus rhythm (p less than 0.02) than that observed in the remaining 267 patients (group II). After valvuloplasty the valve area increased in group I from 1.7 +/- 0.2 to 3.1 +/- 0.7 cm2 (p less than 0.0001). This mean final area was significantly different (p less than 0.0001) than that observed in group II (1.98 +/- 0.6 cm2). No patients with mild mitral stenosis developed progression of mitral regurgitation, and none had any other major complications. Most of them reached a grade I final functional status. At echo doppler follow-up studies we did not observe significant changes in the mean mitral gradient as compared with the immediate hemodynamic results. These findings suggest that early mitral balloon valvuloplasty could be an alternative in trying to favorably influence the natural course of the rheumatic mitral disease in selected patients.

Adult↗
PubMed1991

Induction of interleukin 2 (IL 2) and interferon-gamma and enhancement of IL 2 receptor expression by a CD26 monoclonal antibody.

The ability of the 134-2C2 monoclonal antibody (mAb; CD26) to transmit an activation signal and to affect T cell proliferation has been studied. The 134-2C2 mAb, although not being mitogenic by itself, is able to increase the proliferation of purified T cells in the presence of exogenous interleukin 2 (IL2) or phorbol 12-myristate 13-acetate (PMA). No effect of our mAb was observed on the proliferation of T cells induced by other stimuli such as Sepharose-bound CD3 mAb, phytohemagglutinin or calcium ionophore. Since the co-stimulatory effect of 134-2C2 mAb on PMA-induced T cell proliferation was strongly inhibited by an anti-Tac antibody, its involvement on the IL2/IL2 receptor pathway was investigated. An increased IL2 secretion in T cells cultured with PMA plus 134-2C2 mAb was observed and Northern blot analysis showed that the mAb 134-2C2 acts synergistically with PMA favoring the induction of both IL2 and interferon-gamma mRNA synthesis, as well as the enhancement of IL2 receptor and transferrin receptor mRNA expression. Studies on mechanisms implicated in signal transduction showed that 134-2C2 mAb modifies neither intracellular calcium levels nor phosphoinositide breakdown. Additionally, no effect was exerted on protein kinase C translocation. These data suggest that the CD26 antigen is involved in T cell activation in an IL2/IL2 receptor-dependent pathway.

Antibodies, Monoclonal↗
PubMed1991

Immunophenotypic heterogeneity of multiple myeloma: influence on the biology and clinical course of the disease. Castellano-Leones (Spain) Cooperative Group for the Study of Monoclonal Gammopathies.

In 112 untreated myeloma patients we have analysed the immunophenotype of plasma cells both by immunofluorescence (IF) and immunocytochemistry (APAAP). Both techniques yielded similar results pointing to an important degree of heterogeneity in antigenic expression not only between different patients but also within the same patient. The expression of CD38 and Han-PC1 antigens (Ags) was almost constant (greater than 90% positive cases), while CD9 was detected in 66% of the cases. On the other hand, less than one third of patients were positive for CD10, CD20 and HLA-DR and generally with a weak expression (less than 30% positive plasma cells). In occasional cases plasma cells were weakly positive for the myelomonocytic markers CD13 (9%), CD15 (25%) and CD14 (6%). The possibility that this heterogeneity might be the result of different stages of differentiation of the neoplastic clone is suggested both by the positive correlation in the expression of some of these antigens (CD10, CD9, CD20, HLA-DR) and by the relationship between CD10 and myeloid antigens with immature plasma cell morphology. Finally, the cALLA antigen does not seem to be of significant value in predicting survival. Moreover, none of the other markers explored showed a clear influence in the course of the disease, although the tendency towards a lower survival found for the CD20+ cases as well as the association of the expression of some antigens and advanced clinical stage, may warrant further studies in a larger series of patients.

Aged↗
PubMed1991

Evidence for involvement of catecholamines in the effect of morphine on ventricular automaticity in the rat.

1. The present study examined the effects of morphine on ectopic automaticity induced by local injury in the isolated right ventricle of the rat. 2. Morphine (10(-7)-5 x 10(-5) M) induced a significant increase of ventricular rate similar to that produced by noradrenaline. The excitatory effect of morphine was not modified by the presence of naloxone (5 x 10(-5) M). The maximal effect obtained with morphine in the presence of naloxone was 60 +/- 7%, similar to that obtained with morphine alone (67 +/- 15%). The EC50 values for morphine in the absence (0.89 x 10(-7) M) and presence of naloxone (0.87 x 10(-7) M) were also similar. Apparently this effect is not mediated by postsynaptic opioid receptors. 3. The ventricular automaticity induced in isolated right ventricle of the rat was significantly decreased by the highest concentrations of naloxone (5 x 10(-5) and 10(-7) M). 4. Morphine (10(-9)-5 x 10(-5) M) did not significantly change ventricular automaticity in the presence of propranolol (5 x 10(-8) M) or in reserpinized rats (5 mg kg-1 i.p. 24 h before the experiments). The maximal increases induced by morphine in the presence of propranolol or in reserpinized rats were 5 +/- 0.8% and 16 +/- 14.7% respectively. These results were significantly different from the maximal increase obtained without propranolol or with non-reserpinized animals. It is possible that the effects of morphine on ventricular automaticity could be mediated by an indirect effect located presynaptically at the adrenergic nerve terminals through the release of catecholamines.

Animals↗
PubMed1991

[Incidence of infective diseases at an internal medicine service].

In the clinical records between 1980-1989, there are 3,386 diagnosis of diseases, 34 percent of them were infections, the first great cause of diseases in ten years; the second cause was cardiovascular 16.3%. Infectious disease were localized in urinary tract 19%, Typhoid Fever 15%, pneumonia 11%, tuberculosis 8.5%, cellulitis 8.5%, Viral Hepatitis 8%, Brucellosis 5%, gastrointestinal Tract infections 5% and others 20%. It is necessary improve the epidemiological criteria in the practice of internal medicine, because the elevated numbers of infectious diseases that we are seeing in the Internal Medicina Section.

Communicable Diseases↗
PubMed1991

[Valvulopathies (XIV). The role of percutaneous valvuloplasty in congenital valvular diseases].

The present article describes the cooperative experience Córdoba-Las Palmas since 1983 in 123 patients with congenital right or left ventricular outflow obstructions who were treated by percutaneous balloon dilatation. Seventy of them had pulmonary stenosis (63 valvular and seven supravalvular types); two had pulmonary atresia, 25 valvular aortic stenosis and 27 discrete subaortic stenosis. In patients with valvular pulmonic stenosis the gradient and the right ventricular pressure decreased significantly. No significant changes were observed in the degree of pulmonary regurgitation. One neonate died. No other major complications occurred. After a mean follow up of 3 +/- 2 years, we did not observe significant changes in the degree of pressure relief. The mean residual gradient is 26 +/- 19 mmHg. In our 21 patients out of the neonatal period with valvular aortic stenosis the gradient and the left ventricular pressure dropped significantly. Progression of aortic regurgitation in more than I grade was observed in 4 patients (19%), although only one (5%) progressed to grade III. There were no major complications in this group. After a mean follow up period of 24 +/- 17 months they persist with the obtained pressure relief and same degree of valvular competence. All 4 neonates with critical aortic stenosis had unsuccessful dilations and they died, wether after ulterior surgery or without it. In 27 patients with discrete subaortic stenosis the gradient and the left ventricular pressure decreased markedly, without significant changes in valve competence. There were no related major complications. After dilation, a broken and mobile membrane was frequently seen. At follow up (24 +/- 18 months), 6 patients (22%) had restenosis; five of them were successfully redilated. The remaining 21 patients persist with a reduced residual gradient (24 +/- 7 mmHg) and without significant changes in valve competence.

Adolescent↗
PubMed1991

[Coronary permeability and left ventricular function following thrombolytic therapy].

We study 40 patients, 55 +/- 7 years old with acute myocardial infarction treated early by thrombolytic therapy (20 STK and 20 rt-PA). All patients were angiographically studied in the following conditions: 1) baseline, before initiating therapy. 2) Three hours after treatment. 3) Twenty four hours later. 4) Before discharge. The infarct related artery was patent 24 hours after treatment in 31 patients (78%); five of them were patent before treatment, and we observed an early reperfusion in 20 patients (57%) and late reperfusion in 6 patients (17%). The number of patients with angiographic evidence of intraluminal thrombus decreased progressively through conditions while the grade TIMI of coronary perfusion increased in the absence of reocclusion. Final regional wall motion of infarct related myocardial zones and their degree of recovery were significantly higher in recanalized patients, as compared with non-reperfused patients. Similarly, left ventricular functional recovery was higher in patients with antegrade of collateral flow to the infarct area, as compared with totally occluded patients.

Coronary Angiography↗
PubMed1990

Factors influencing progression of mitral regurgitation after transarterial balloon valvuloplasty for mitral stenosis.

This study analyzes the clinical, echocardiographic and hemodynamic factors affecting progression of mitral regurgitation (MR) after transarterial balloon valvuloplasty in 200 consecutive patients with rheumatic mitral stenosis. After valvuloplasty, the mitral valve area increased in all patients, from 1.03 +/- 0.36 to 2.06 +/- 0.71 cm2 (p less than 0.0001). With regard to the basal stage, the mitral valve was competent in 139 patients and there was mild MR in 61 (grade I in 53, and grade II in 8). Three patients had progression of MR induced by a technical deficiency and they were excluded from analysis. Patients were classified into 2 groups on the basis of the degree of MR before and after valvuloplasty: group A--no progression of MR (n = 167; 85%) when the degree of MR did not change, disappeared after valvuloplasty, or increased from grade 0 to I; group B--progression of MR (n = 30; 15%) when the degree of MR increased to greater than or equal to grade II. Progression of MR was observed more frequently in older patients with presence of chronic atrial fibrillation, larger left atrial size and left ventricular volumes, baseline MR, more severe stenosis and a lower ejection fraction. Multivariate analysis selected age, left ventricular volumes and ejection fraction as independent predictors of progression of MR. All these factors suggest that progression of MR after balloon valvuloplasty could be related to a more advanced degree of disease.

Age Factors↗