Search PubMed⌕ Search

Biomedical subjects

M Ramos

Publications and source records attributed to M Ramos.

At least 91 records · Page 5Linked to original sources

[The solitary pulmonary nodule. A retrospective study of 119 cases].

The authors review 119 cases of solitary pulmonary nodule submitted to surgery, analysing their aetiology and correlating them with their clinical and radiological aspects as well as with the patient's age, sex and smoking habits. An analysis of some pre-surgical diagnostic methods was also made. In half of the nodules (54%) the diagnosis made was of malignancy. Some of these (8%) were pulmonary metastases. There was no sex preference in the distribution of malignant or benign lesions. The average diameter of malignant nodules was 2.8 +/- 10.9 cm and benign nodules 2.1 +/- 10.9 cm. The large majority of malignant lesions was found in both upper lobes, whilst benign lesions did not have a preferential location. Adenocarcinomas were the most common primary lung tumours found, (59%), followed by squamous (27%) and neuroendocrine tumours (12.5%). Most benign nodules were benign neoplasias (43%--hamartomatous tumours) or of infectious aetiology (mostly granulomatous chronic disease--39%). The evaluation of the imagiological criteria of benignity or malignancy resulted in a sensitivity of 67% and specificity of 76%. In this study, negative respiratory cytology and bronchofibroscopic biopsies were not particularly helpful in excluding malignancy. This study confirms results published by other authors, in concluding that larger nodules have a greater probability of malignancy, that these are more frequent in males with smoking habits, and that they predominate in the upper lobes.

Adult↗

Typical and atypical lung carcinoids: clinical and morphological diagnosis.

Forty cases of carcinoid tumors of the lung were studied retrospectively from 1989-1993 in the Pathology Department of Hospital Pulido Valente in Lisbon. The mean age of patients was 44 years old, and the presenting symptoms included hemoptysis, cough, thoracic pain, fever, and dyspnea. An endobronchial mass was seen in 75% of the cases. The histopathological study was based on the following morphological criteria: disorganized architecture with increased cellularity (8 cases; 20%), nuclear pleomorphism (14 cases; 22%), the presence of coarse chromatin (19 cases; 30%), increased mitotic activity (13 cases; 21%), enlarged nucleoli (17 cases; 27%), necrosis (12 cases; 25%), vascular permeation (8 cases; 15%), distant metastasis (6 cases; 14%). Chromogranin was the most strongly reliable immunostaining for the diagnosis. In our series the initial routine diagnosis and the diagnosis after morphological criteria evaluation matched, and in 14 cases the final diagnosis was of atypical carcinoids.

Adolescent↗

[Primary Sjögren's syndrome: clinical and immunologic study of 80 patients].

BACKGROUND: To determine the clinical and immunologic characteristics of a large cohort of patients with primary Sjörgen's syndrome (SS) and to asses if the sex, the age at onset, the time of evolution and the immunologic pattern define different subsets with specific characteristics. PATIENTS AND METHODS: We included 80 patients (76 female and 4 male) that were prospectively studied at our Unit. All patients fulfilled the European Community criteria proposed in 1993 for the diagnosis of SS. RESULTS: Mean age of patients was 62 years with a mean disease duration of 8 years. The most frequently observed clinical manifestations were xerostomia (96%), xerophthalmia (94%) and parotidomegaly (46%). The main extraglandular manifestations were arthritis (45%), Raynaud's phenomenon (20%) and liver involvement (19%). The immunologic study showed antinuclear antibodies in 82% of patients, rheumatoid factor in 45%, anti-Ro/SS-A in 40% and anti-La/SS-B in 20%. In patients with an onset of disease before the age of 40 years, a higher prevalence of parotidomegaly, peripheral neuropathy, cutaneous vasculitis, rheumatoid factor, anti-Ro/SS-A and anti-La/SS-B antibodies was observed. A disease duration longer than 10 years was associated with a higher prevalence of pulmonary involvement and more focus of mononuclear cells in the minor salivary glands. Clinical manifestations associated to any one or more immunologic marker (rheumatoid factor, anti-Ro/SS-A and/or anti-La/SS-B) were Raynaud's phenomenon, arthritis, thyroid disease, cutaneous vasculitis and peripheral neuropathy. CONCLUSIONS: Primary SS is an autoimmune disease characterized by a marked heterogeneity in the clinical presentation and evolution, thus allowing the definition of several subsets of patients with their own clinical and immunological characteristics.

Adult↗

A Streptomyces fradiae protease dissociates structurally preserved neurons and glial cells from the embryonic and adult central nervous system of vertebrates.

Nerve cell dissociation has become a key procedural tool in the implementation of a number of techniques in cellular and molecular neurobiology. We report that a protease preparation from Streptomyces fradiae (henceforth SF-protease) dissociates viable and morphologically identifiable embryonic and mature neurons and glial cells from the central nervous system of chick and rat, when used under strictly controlled conditions. Typical dendritic and axonal growth cones, with their lamellipodia and filopodia, are seen in many neuroblast types - growth cones in the case of embryonic glial cells and even the thinnest processes of some cells, such as the microvilli of adult chick retinal Müller (glial) cells, or the cilia of photoreceptors appear intact. Our results suggest that the SF-protease releases cells from tissue in a way that ensures the continuity of the plasma membrane and cuts through the transmembrane attachment systems (either cell-cell or cell-extracellular matrix) without compromising the cytoskeletal integrity underlying native cell shape.

Animals↗

Capillary electrophoretic analysis of genetic variants of milk proteins from different species.

Polymorphism of bovine, ovine and caprine milk proteins was studied by CE. Identification of some rare bovine variants was carried out by isoelectric focussing (IEF) using PhastSystem. Genetic variants A and D of bovine alpha s2-casein, beta-casein variants A1, A2, A3, B and C and alpha s1-casein variants B and C were determined by CE. In addition, the different casein fractions including some genetic variants of ovine and caprine milk were identified by CE. In order to carry out this identification, collected fractions from a cation-exchange FPLC separation were injected by CE.

Animals↗

Specific binding of [3H]GppNHp to extracellular membrane receptors in chick cerebellum: possible involvement of kainic acid receptors.

Guanine nucleotides (GNs), including GMP, displace [3H]kainic acid binding to chick cerebellar lysed and vesiculated membranes. Saturation studies of [3H]GppNHp binding, under conditions that prevent the occupation of the nucleotide binding sites in G-proteins, demonstrate the existence of extracellular membrane receptors specific for guanine nucleotides. Affinity-labeling of a vesicle preparation with [alpha-32P]GTP gives one single labeled band, upon electrophoresis, with an apparent molecular mass of 50 kDa. Additional experiments with partially purified kainate receptors suggest that the GN extracellular sites may overlap, at least partially, the kainic acid binding sites, being then responsible for the displacement of [3H]kainic acid by GNs. The physiological significance of these findings remains unclear.

Animals↗

Study of the polymorphism of caprine milk caseins by capillary electrophoresis.

Polymorphism of caprine milk proteins was studied by capillary electrophoresis. Identification of casein (CN) fractions was effected by using isolated fractions from cation-exchange fast protein liquid chromatography. Genetic polymorphisms in caprine alpha s2-CN, alpha s1-CN, beta-CN and kappa-CN have been determined. kappa-CN A and B, beta-CN A and null, alpha s2-CN A, B and C, alpha s1-CN A, B, C and null, and other forms with intermediate and low alpha s1-CN content have been identified. The capillary electrophoresis method made it possible to analyse whole caprine milk using simple sample preparation and was rapid, automated and suitable for phenotyping studies. This method may also permit the quantitative study of different protein fractions.

Animals↗

Study of the polymorphism of ovine alpha s1- and alpha s2-caseins by capillary electrophoresis.

Polymorphism of ovine alpha s-caseins was studied by capillary electrophoresis at pH 3.0 +/- 0.1. Individual caseins (CN) were selected according to their genetic variants, as determined by PAGE and isoelectric focusing. The ovine caseins, containing different genetic variants of alpha s1-CN and alpha s2-CN, were fractionated by cation-exchange FPLC. The alpha s1-CN variants A, B and C, and the fast moving alpha s2-CN variant were identified by a capillary electrophoresis method. The fast moving alpha s2-CN variant, so-called for its behaviour in PAGE, also had a faster electrophoretic mobility than the common alpha s2-CN when analysed by the present technique. The capillary electrophoresis method gave excellent, rapid, automated separation of alpha s1-CN and alpha s2-CN variants and was suitable for screening studies.

Animals↗

Renin, prorenin, and renin gene expression in rats with acute nephrotic syndrome.

1. The concentration of total, active and inactive renin was analysed in plasma, urine and kidney from control (C), pair-fed (PF) and nephrotic (NS) rats, as well as renin mRNA levels in kidney, liver and brain. 2. Nephrotic syndrome were induced by a single subcutaneous injection of puromycin aminonucleoside (PAN) and determinations were made 6 days after PAN injection. 3. Plasma total renin did not change, active renin increased in NS rats with respect to PF and C groups and in PF rats with respect to C. In contrast, the inactive renin percentage decreased in NS rats with respect to PF and C groups and in PF animals with respect to C. Total, active and inactive renal renin content did not change and active and inactive renin were significantly excreted by urine with no changes in the prorenin percentage with respect to C and PF groups. 4. In both NS and PF groups, renin mRNA levels did not change in any of the tissues studied. In another group of rats, kidney renin mRNA levels were measured on days 1, 3, 5 and 7 after PAN injection and no time-course changes in its expression were found. 5. These results suggest that renin gene expression is not altered in acute nephrotic syndrome and that plasma renin concentration is regulated at the translational or post-translational level in this experimental model.

Acute Disease↗

Hepatitis C virus infection in 'primary' Sjögren's syndrome: prevalence and clinical significance in a series of 90 patients.

OBJECTIVES: To determine the prevalence and clinical significance of hepatitis C virus (HCV) infection in a large cohort of patients with "primary' Sjögren's syndrome (SS). METHODS: 90 consecutive patients (83 female and seven male) were included, with a mean age of 62 years (range 31-80) who prospectively visited our unit. All patients fulfilled the European Community criteria for SS and underwent a complete history, physical examination, as well as biochemical and immunological evaluation for liver disease. Serum from all patients was tested for antibodies to HCV by third generation enzyme linked immunoassay and positivity was confirmed by polymerase chain reaction. RESULTS: Antibodies to HCV were present in 13 (14%) patients with 'primary' SS. When compared with patients without HCV infection, patients with HCV infection presented a higher prevalence of hepatic involvement, (100% v 8%, p < 0.05). Transcutaneous liver biopsy was performed in five patients with HCV infection, and specimens obtained showed in all cases a chronic active hepatitis with varying degrees of portal inflammation. CONCLUSION: HCV infection is frequent in patients with "primary' SS and liver involvement is presented in all these patients. The possible pathogenic role of HCV infection in these patients is still unclear.

Adult↗

Hepatic and extrahepatic angiotensinogen gene expression in rats with acute nephrotic syndrome.

Plasma concentration and urine excretion of the renin-angiotensin system proteins are altered in rats with nephrotic syndrome (NS). In this work the messenger ribonucleic acid (mRNA) levels of angiotensinogen (Ao) were analyzed with the slot-blot hybridization technique in liver and other extrahepatic tissues: kidney, heart, brain, and adrenal gland from control, nephrotic, and pair-fed (PF) rats. NS was induced by a single injection of puromycin amino-nucleoside (PAN). Although a great urinary excretion and half-normal plasma levels of Ao were observed on day 6 after PAN injection, when NS was clearly established, hepatic Ao mRNA levels did not change. Furthermore, the Ao mRNA levels did not change in any of the extrahepatic tissues studied on day 6, nor did its hepatic levels at days 1, 3, 5, or 7 after PAN injection. These data suggest that the hepatic and extrahepatic Ao mRNA levels are unaltered during the development of the acute NS induced by PAN.

Acute Disease↗

Fanconi's anaemia: case history of six Spanish families.

We report on the results obtained in 6 Fanconi's anaemia families (FA) (parents, brothers and sisters) affected by at least one of the symptoms usually observed in FA. The 6 FA families were studied from 1974 to 1990, all having located in Madrid (Spain) but with different ethnic origin: 3 families are of Spanish descent and the other 3 are gipsy families. All showed characteristics of the disease, including malformations, stunted growth, microcephaly, skin hyperpigmentation, high incidence of chromosomal breaks in lymphocyte cultures, and hematological and biochemical abnormalities: pancytopeny, increased fetal hemoglobin levels and significantly decreased superoxide dismutase (SOD) activity. (Ref. 17.)

Fanconi Anemia↗

[Greater sensitivity of the PCR-SSCP technique compared with immunohistochemistry for the detection of exon 5 and 6 mutations of gene 53 in breast cancer].

BACKGROUND: p53 mutations constitute the most frequent genetic abnormality observed in breast cancer. The molecular study of p53 mutations not only provides prognostic information but also allows a better understanding of tumor biology. Most of the studies on p53 have been done by immunohistochemistry procedures. In this study we compare the sensitivity of immunohistochemistry and molecular genetics methods for the detection of p53 mutations. PATIENTS AND METHODS: Forty tumors obtained from breast cancer patients that underwent modified radical mastectomy were analyzed for p53 mutations at exons 5 to 6 through PCR-single stranted conformational polymorphism (SSCP)-sequencing. Moreover, the tumor expression of p53 protein was analyzed by means of immunohistochemistry. RESULTS: All tumors could be amplified by PCR and analyzed by the SSCP technique. Six tumors (15%) showed and altered electrophoretic mobility. In these cases a mutation was confirmed by gene sequencing. On the other hand, only two of these six tumors were positive in the immunohistochemical analysis. CONCLUSIONS: The results confirm the utility of the PCR-SSCP technique for detection of p53 mutations and suggest to be more sensitive than immunohistochemistry.

Base Sequence↗

Simultaneous administration of 99Tcm-HMPAO-labelled autologous leukocytes and 111In-labelled non-specific polyclonal human immunoglobulin G in bone and joint infections.

The aim of this study was to investigate the ability of 111In-labelled human polyclonal immunoglobulin G (111In-IgG) to localize bone and joint infections compared with 99Tcm-HMAPO-labelled leukocytes (99Tcm-WBC). Thirty-four patients routinely referred for investigation of bone and joint infections were studied. In all patients, a bone scan using 99Tcm-MDP was initially obtained. Subsequently, 99Tcm-WBC and 111In-IgG were simultaneously injected and images obtained at 30 min, 4 h and 24 h post-injection. Diagnostic accuracy was established by bacteriology of specimens obtained by needle aspiration and/or surgery, other imaging methods and clinical follow-up. The images were read by three experienced observers blinded to any other information; the clinical suspicion of infection and the diagnosis were established when two observers agreed. Infection was confirmed in 11 patients. The 99Tcm-WBC scans gave 8 true-positive, 5 false-positive, 18 true-negative and 3 false-negative results. With 111In-IgG, the figures were 7, 6, 17 and 4, respectively. The sensitivity, specificity and accuracy were 72.7%, 78.2% and 76.4% respectively for the labelled leukocytes and 63.6%, 73.9% and 70.6% respectively for 111In-IgG. There was greater agreement between the observers with 99Tcm-WBC than 111In-IgG. In this study, 111In-IgG was less sensitive and less specific than 99Tcm-WBC scintigraphy for the diagnosis of chronic infections, but these differences were not significant. Both tracers appear to be useful in the diagnosis of bone and joint infections. However, our results were less reliable for the diagnosis of an infected prosthesis.

Adult↗

[Frequency of anti-Cysticercus cellulosae antibodies in individuals from five counties in the Northern region of Brazil].

An epidemiological and serological study was carried out on a sample of 2,180 individuals, in five counties in the north of Paraná State-Brazil, using the indirect immunofluorescence test to detect anti-Cysticercus cellulosae antibodies. These individuals, 69 (3.2%) showed significant titers of antibodies. No single significant difference between the proportion of reactivity in Sarandi (6.6%) and in Marialva (4.7%) was observed (Z = 1,319, P = 0.0936), but it was significantly higher than that observed in Mandaguaçu, Paiçandu and Maringá (P < 0.01). Of these individuals, 47.9% were within 21-49 years old and 79.4% were of female sex. "Headache" (70.6%), "faintness" (57.4%), and "convulsions" (7.4%) were among the most frequent by reported, moreover, cases of Taenia infections (22.1%) and the custom of eating uncooked beef (41.2%) or pork (27.9%) and meat containing cysticerci (25.0%) were also related.

Adolescent↗