PubMed Health⌕ Search

Biomedical subjects

S Romero

Publications and source records attributed to S Romero.

At least 19 recordsLinked to original sources
PubMed1997

Detection of sugar residues in rabbit embryo teeth with lectin-horseradish peroxidase conjugate: II. A light microscopal study.

The cellular distribution and changes of sugar residues during tooth development in embryos of the rabbit Oryctolagus cuniculus were investigated by using horseradish peroxidase-conjugated lectins (lectin-HRP). The lectins SBA, ECA, and LTA show no binding to any region of the dental cap and bell stages, whereas BS-1 and UEA-1 bind to dental cells at both stages. Appropriate control studies confirmed the specificity of the binding of the lectins. At cap stage, the lectins BS-1 and UEA-1 show moderate binding to the (pre)-ameloblast and (pre)-odontoblast cells. These results suggest that the acetylgalactosamine and alpha-L-fucose residues present in (pre)-ameloblasts and (pre)-odontoblasts, respectively, are common to determined but relatively undifferentiated cells capable of forming matrices of hard tissues. Since the odontoblast and ameloblast express dentin and enamel, respectively, it can be speculated that the abundance of these residues in these cells might be associated with the maintenance of the capacity of the cells to produce such matrices. At the bell stage, the odontoblasts display considerable amounts of alpha-L-fucose, whereas alpha-L-fucose is poorly localized in ameloblasts. However, ameloblasts contain significant quantities of N-acetylgalactosamine, whereas only a diffuse positivity for this carbohydrate is apparent in odontoblasts. The marked changes of the glycosylation pattern of these glycoconjugates might indicate that they play a role during the cell-to-cell interaction and might also be involved in the odontoblastic and ameloblastic functional activity. Such a possibility is entirely speculative until specific in vitro experiments are conducted.

Animals↗
PubMed1996

Inducible nitric oxide synthase and the regulation of central vessel caliber in the fetal rat.

BACKGROUND: The purpose of this study was to evaluate the possibility that inducible nitric oxide synthase (iNOS) regulates the fetal circulation. METHODS AND RESULTS: Positive evidence for iNOS gene expression was noted in heart central vessels and placenta of untreated rat fetuses. Rats in the last week of pregnancy were treated for 5 days with L-NG-(1-Iminoethyl)lysine (L-NIL), a selective inhibitor of iNOS, at 1, 10, and 100 micrograms/mL in the drinking water. To raise NO levels, lipopolysaccharide (LPS) 30 micrograms/kg was given by intraperitoneal injection, and sodium nitroprusside (SNP) was placed in mini-osmotic pumps to deliver 10 micrograms/kg per minute. Control animals were undisturbed. On day 21 of gestation, dams were anesthetized and fetuses were delivered by cesarean section and rapidly frozen in isopentane chilled in liquid nitrogen. Frozen sections (10 microns) were used to reconstruct a computer-generated three-dimensional image of the great vessels and ductus arteriosus. Significant constriction of the great vessels and ductus arteriosus was observed with L-NIL, whereas both LPS and SNP dilated these vessels. The vasorelaxant effect of LPS was blocked by L-NIL. NO release from placental explants was 633 +/- 41 nmol/L under basal conditions, increasing to 4.0 +/- 0.4 mumol/L with LPS administration, although placental iNOS message and protein levels were unchanged. CONCLUSIONS: We suggest that nitric oxide, generated by iNOS, plays a significant role in control of major vessel and ductus arteriosus caliber in the rat fetus. In regard to the nitrergic regulation of the circulation, the fetus is clearly different from the adult.

Animals↗
PubMed1996

Light microscopic detection of sugar residues in rabbit embryo teeth with lectin-horseradish peroxidase conjugates.

We investigated the binding of five HRP-conjugated lectins to rabbit tooth germs at the cap and late bell stages of development. The results revealed some changes in the glycosylation patterns of the glycoconjugates. Sugar residues, such as alpha-D-mannose, methyl-D-glucose, N-acetylglucosamine, beta-D-galactosamine, D-galactose, and sialic acid, were detectable in some components of the tooth germs. The most conspicuous developmental change was increased binding of Con A and WGA. These lectins showed, at the cap stage, moderate binding to the (pre)-ameloblasts and (pre)-odontoblasts. With further development to the late bell stage, but prior to the achievement of well-defined morphological-functional characteristics, the odontoblasts and ameloblasts displayed considerable amounts of alpha-D-mannose, alpha-D-glucose as well as beta-D-acetylglucosamine and sialic acid. Appropriate control studies confirmed the specificity of the binding of the lectins. Two lectins (DBA and PNA) with known specificity for N-acetylgalactosamine groups were bound by the basement membranes in tooth germs at the cap stage. A third lectin (RCA) with the same specificity did not produce any detectable staining in the same material. Further studies must be planned to determine the specific functions and significance of lectin-HRP-binding glycoconjugates in odontogenesis.

Animals↗
PubMed1996

CEA, CA 15-3 and CYFRA 21-1 in serum and pleural fluid of patients with pleural effusions.

The role of tumour marker assays in differentiating malignant from benign pleural effusions is not yet clear. This study was designed to prospectively assess the individual and combined diagnostic utility of three tumour markers in patients with pleural effusion. Pleural and serum levels of carcinoembryonic antigen (CEA), carbohydrate antigen 15-3 (CA 15-3) and cytokeratin 19 fragment (CYFRA 21-1) were determined in 115 patients with pleural effusions (42 malignant and 73 benign). The diagnostic utility of each tumour marker was assessed using accuracy to determine the optimal cut-off point, whilst a logistic regression model was used to obtain the optimal combined test. In serum, every marker showed an individual high specificity (over 97%) for malignancy. The sensitivity of CEA, CA 15-3 and CYFRA 21-1 was 36, 48 and 31%, respectively. In patients without renal failure, the sensitivity of CYFRA 21-1 rose to 53%, while those of CEA and CA 15-3 remained almost unchanged. In pleural fluid, CYFRA 21-1 showed low sensitivity (32%) and specificity (82%), while CEA showed the highest sensitivity (57%). Excluding patients with renal failure, the combined determination in serum of CEA, CA 15-3 and CYFRA 21-1 has a high accuracy (88%), similar to that for CEA plus CA 15-3 in pleural fluid (87%). We conclude that CYFRA 21-1 is useless in pleural fluid and should not be used in serum for patients with renal failure. The combined determination of CEA, CA 15-3 and CYFRA 21-1 in serum may obviate its determination in pleural fluid.

Adolescent↗
PubMed1995

Effect of body position on gas exchange in patients with unilateral pleural effusion: influence of effusion volume.

The objective of this study was to evaluate the effect of lateral body position on gas exchange in patients with unilateral pleural effusion, with special reference to the influence of effusion volume. Thirty consecutive patients with unilateral pleural effusion, without evidence of parenchymal pulmonary involvement, were entered into the study. Arterial blood gas tensions (PaO2, PaCO2) were randomly measured in both right and left lateral decubitus body positions, while breathing room air. To assess the influence of the effusion volume, roentgenographic and functional parameters were used. Among the latter, FVC, FEV1, TLC and RV were determined. The influence of the presence or absence of pleuritic pain on gas exchange was also assessed. There was no significant difference in PaCO2 between right and left lateral decubitus body positions (31.1 +/- 4.2 vs. 31.0 +/- 4.5 mmHg). The differences in PaO2 between the two body positions ranged from 0.5-25 mmHg (mean 9.3 +/- 6.6 mmHg). Mean PaO2 with the normal-side (control) down (PaO2-N) (81.4 +/- 8.5 mmHg) was higher, but without significant statistical difference, than mean PaO2 with the effusion-side down (PaO2-E) (78.0 +/- 12.5 mmHg). PaO2-N was higher than PaO2-E in 22 of 30 patients (conventional), and lower in eight patients (paradoxical). No consistent relationship was found for alterations in PaO2 in different positions with the volume of effusion, either when estimated by a roentgenographic method or when using spirometric or plethysmographic values.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

[Hematological serological valves, and organ weight in adult Sprague-Dawley rats].

Sprague-Dawley rats are frequently used in experiments and their normal hematological, serologic and anatomical parameters are not easily available. The aim of this study was to measure these parameters in adult Sprague-Dawley rats. Twenty-four rats (12 males) whose weight ranged between 200 and 300 g, raised at the Instituto de Salud Pública in controlled environmental conditions and fed with pellets were studied. After a 24 h fast, animals were anesthetized with Droperidol and Ketamine, and after obtaining a cardiac blood sample, sacrificed by exsanguination. Most organs were withdrawn and weighed. Mean values for blood glucose, calcium, amylase, total proteins, cholesterol, AST, ALT, bilirubin, alkaline phosphatases, electrolytes and complete blood count were determined. Heart, lung, pancreas, kidney and testicle mean weight was also calculated. Male and female rats had significant differences in packed red cell volume, white blood cell count and hemoglobin.

Animals↗
PubMed1994

Lung metastases from prostatic carcinoma: orchidectomy-induced remission in two patients.

Two patients with pulmonary metastases from a prostatic carcinoma are described. When first seen by the pulmonary physician, respiratory symptoms were predominant and diagnosis of the primary site was not yet made. Orchidectomy achieved an impressive response with regression of symptoms and radiological lesions within weeks. Since metastatic deposits from prostatic origin may respond promptly to endocrine manipulation, this possibility must be taken into account in the evaluation of any patient with pulmonary metastases of unknown origin.

Adenocarcinoma↗
PubMed1994

[Evaluation of the fibrinolytic system in myocardial infarction].

PURPOSE: To evaluate the main components of the fibrinolytic system in patients suffering of acute myocardial infarction (AMI), both in the acute phase and once this has been overcome. PATIENTS AND METHODS: Components of the fibrinolytic system (i.e., PAI-1, t-PA, fibrinogen, plasminogen, and alpha 2-antiplasmin) were determined in 100 patients with AMI. The studies were performed at AMI and 6 months later, and the findings were compared with those of a control group of 30 people matched with regard to age and sex with the patient group. The statistical analysis of the results was made with the BMPD pack, using Student's t test for comparing quantitative variables and the matched test for paired samples. RESULTS: At the acute phase the patients showed significant increase of PAI-1 (p < 0.001) and fibrinogen (p < 0.05) concentrations. Plasminogen and alpha 2-antiplasmin rates were lower than in the control group (p < 0.01 and p < 0.005, respectively). In the 6-month study after AMI, significant increase of PAI-1 was found with respect to the control group (p < 0.001). There were also significant differences in the initial PAI-1 rates and the 6-month test (p < 0.05), whereas the increased fibrinogen rates persisted (p < 0.01). Increased antigenic t-PA was found in the patient group before venous occlusion (p < 0.001). Thus, 54 patients (54%) had hypofibrinolysis, due to increased PAI-1 in 41 cases (41%), impaired t-PA release in 13 cases (13%) and both causes in 12 cases (12%). CONCLUSIONS: Fibrinolytic hypofunction was found in this study during the acute phase of myocardial infarction, which was still present six months later, and was due to increased PAI-1 rates in the majority of the cases.

Aged↗
PubMed1993

Evaluation of different criteria for the separation of pleural transudates from exudates.

OBJECTIVES: To determine the relative usefulness of different criteria for the separation of pleural transudates from exudates. DESIGN: Prospective evaluation of patients referred for thoracentesis. SETTING: Community teaching hospital. PATIENTS: Three hundred fifty-one consecutive patients with pleural effusions referred for thoracentesis. Fifty-four of these patients were excluded from the analysis. MEASUREMENTS: We recorded clinical characteristics and final diagnosis and measured pleural fluid and serum levels of total protein, lactate dehydrogenase, and cholesterol. All patients included were followed up until final diagnosis. MEAN RESULTS: Forty-four (15 percent) pleural effusions were transudates and 253 (85 percent) were exudates. The criteria of Light et al, with a sensitivity of 98 percent and a specificity of 77 percent for exudates, showed the best accuracy (95.2 percent). Moreover, when the cutoff used for the criteria of Light et al was modified according to our own laboratory results, specificity rose to 93 percent with almost a similar accuracy (94 percent). Protein pleural fluid/serum ratio > 0.5 and pleural fluid cholesterol > 60 mg/dl showed equal specificity (91 percent), but the former had better sensitivity for exudates (88 percent vs 81 percent). CONCLUSIONS: When the proportion of exudates included is 85 percent or more, as in the present series, the criteria of Light et al remain the method that offers the highest accuracy for segregating transudates from exudates.

Adolescent↗
PubMed1992

[Analysis of data from a database of patients submitted to cardiac catheterization].

77 variables with data from clinical, non invasive and invasive findings in 591 adult patients submitted to cardiac catheterization and/or coronary arteriography from 1988 to 1991 were analyzed. 51% had coronary arteriography for suspected coronary artery disease: 15% had no or insignificant disease and 8% had main left disease. Among 92 patients with valvular heart disease, coronary angiography ruled out coronary disease in 80%. In this group, 3 vessel disease was found only in patients older than 62 years of age and main left disease was rare. The etiology of valve disease was rheumatic in 72%. Congenital heart disease was the indication for invasive study in 8% of patients, atrial septal defect being the most common entity.

Adult↗
PubMed1992

[Value of the determination of CA 15-3 in the diagnosis of malignant pleural effusion].

In 160 consecutive patients with pleural shedding, antigen CA 15-3 values in pleural fluid were determined, in a prospective way using monoclonal antibodies (115D8 and DF3). In 49 patients with malignant pleural shedding, the mean value of CA 15-3 (47.6 U/ml) was significantly higher (p less than 0.01) to the values in the 111 benign ones (12.9 U/ml). Its sensibility for malignity, with a trough level of 27 U/ml, was of 37% with an specificity of 96%. When a specificity of 100% was required its sensibility (18%) was significantly lower to the carcinoembryonic antigen (CEA) (33%), measured simultaneously with comparative purposes. The simultaneous determination of both markers raised sensibility to 39%, without reaching statistical signification. In the ten patients whose pleural sheddings was secondary to breast carcinoma, both minimum (15 U/ml) as medium (110 U/ml) values, as well as CA 15-3 sensibility (80%), were higher to the ones found in the rest of patients with shedding of malignant origin, but without a clear superiority over the values obtained with CEA. Based on these results, we conclude that the usefulness of the determination, as a tumoral marker, in pleural fluid, of CA 15-3 is lower than CEA and that its simultaneous determination seems not justified. We think that its specific usefulness in pleural sheddings secondaries to breast carcinomas deserves a study with a bigger sample.

Adolescent↗
PubMed1991

Unilateral absence of a pulmonary artery: congenital disease or embolic occlusion?

A young man with congenital absence of the left pulmonary artery is reported. A right aortic arch and normal pulmonary pressures essentially rule out an alternate diagnosis of occlusive chronic thrombus in the central pulmonary arteries. Recurrent or massive haemoptysis makes an exact knowledge of the pulmonary circulation advisable.

Adolescent↗
PubMed1990

[Diagnostic usefulness of the determination of serum neuron-specific enolase in small cell bronchial carcinoma].

The plasma level of neuron-specific enolase (NSE) was measured in 55 patients with small cell bronchial carcinoma (SCC) with cytohistological confirmation to evaluate its diagnostic usefulness. As a control group, 132 patients with non-small cell bronchial carcinoma, 81 with non-neoplastic disease and 37 healthy individuals were used. The sensitivity of the test was 84% with a specificity of 79% when values below 13 ng/mg were considered as normal. To achieve a specificity of 95% and 99% cutoff values had to be increased to 25 and 50 ng/ml, respectively, and then the sensitivity was reduced to 51% and 38%. There were false positive findings in the three control groups, although they were more common (28%) and had higher values in patients with widespread disease the sensitivity was significantly higher (p less than 0.005) than in those with limited disease. Carcinoembryonic antigen, which was measured with comparative purposes, had a lower sensitivity. In our area, a NSE level over 50 ng/ml is closely correlated with the diagnosis of SCC, whereas values over 13 ng/ml select a wider group of individuals where most patients with this type of carcinoma are included.

Adenocarcinoma↗