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Biomedical subjects

S Ramos

Publications and source records attributed to S Ramos.

123 records · Page 7Linked to original sources
PubMedDate not supplied

The oxidant/antioxidant network: role of melatonin.

Melatonin is now known to be a multifaceted free radical scavenger and antioxidant. It detoxifies a variety of free radicals and reactive oxygen intermediates including the hydroxyl radical, peroxynitrite anion, singlet oxygen and nitric oxide. Additionally, it reportedly stimulates several antioxidative enzymes including glutathione peroxidase, glutathione reductase, glucose-6-phosphate dehydrogenase and superoxide dismutase; conversely, it inhibits a prooxidative enzyme, nitric oxide synthase. Melatonin also crosses all morphophysiological barriers, e.g., the blood-brain barrier, placenta, and distributes throughout the cell; these features increase the efficacy of melatonin as an antioxidant. Melatonin has been shown to markedly protect both membrane lipids and nuclear DNA from oxidative damage. In every experimental model in which melatonin has been tested, it has been found to resist macromolecular damage and the associated dysfunction associated with free radicals.

Animals↗
PubMedDate not supplied

[The importance of chest radiograph in the diagnosis of Scimitar syndrome]

OBJECTIVE: To emphasize the importance of chest X-Rays in the diagnosis of Scimitar Syndrome. This anomaly is usually characterized by the presence of anomalous venous drainage of the right lung to the inferior vena cava, abnormal bronchial segmentation, and alterations of pulmonary artery and right lung vascularization.METHODS: The authors report a case of Scimitar Syndrome in an 8 year-old-child, discussing its diagnostic methods and surgical treatment.RESULTS: The child presented good outcome after surgical therapy, with an uneventful follow-up.CONCLUSION: The Scimitar Syndrome is a rare anomaly, which may present few clinical manifestations. The chest X-Ray is a very relevant tool in the screening of this disease, since it discloses a persisting right paracardiac image, as a result of abnormal right pulmonary venous drainage to inferior vena cava ("Scimitar sign").

Journal Article↗
PubMedDate not supplied

[Calcifications from cardiac etiology in chest radiography]

OBJECTIVE: Children s chest X-ray calcification images can be related to pulmonary, mediastinal and rarely cardiac parenchymatous pathology. This report describes cases of cardio thoracic calcifications. We emphasize the importance of chest X-ray to track thoracic calcifications. In spite of the fact that it is rare, the cardiac etiology must be considered due to the possibility of surgical treatment.METHODS: Regarding the period from 1988 to 1997 the authors reviewed the chest X-rays of 2108 patients. In 3 of them thoracic calcifications of cardiac etiology were observed.RESULTS: Of these three patients, two were 7 years old and the third was 3 years old. Case 1 presented a calcification in the right atrium topography caused by a heart tumor of Fibroma type. In case 2 the calcification was in the pulmonary trunk, presenting as a calcified aneurysm of the ductus arteriosus. In case 3 the child had pulmonary stenosis and the chest X-ray showed a calcified image on the left cardiac boards caused by a thrombo in the right ventricle wall.CONCLUSION: The authors emphasize the importance of chest X-ray in the diagnosis of thoracic calcifications, and comment that in spite of the being rare, the cardiac causes should be considered due to the possibility of surgical treatment.

Journal Article↗
PubMedDate not supplied

[Radiotherapy in glottic T1 carcinoma. Local control and survival].

Between January 1980 and April 1995, 57 treatment-naive patients diagnosed as glottic epidermoid T1 carcinoma were treated in the ear, nose and throat department of Juan Canalejo Hospital of La Coruña, Spain. Seventy-nine percent (79%) (45/57) had T1a lesions and 21% (12/57) had T1b. All patients were treated by the radiotherapy department of the Regional Oncological Center with Co60 at doses ranging from 50 Gy to 70 Gy. Local control was achieved in 74.5% (43/57). Cause-specific survival was 96% at 3, 5, and 10 years. The larynx was preserved in 96.5% (55/57). The local recurrence rate was significantly lower for T1a (16.8%) than for T1b (57.8%) (p < 0.05). No significant differences were found in local control or survival with different dosing regimens.

Adult↗
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[Cluster headache in a 3 year old child].

INTRODUCTION: Cluster headache is a rare disorder in childhood. We identified, in the literature, 64 cases of cluster headache starting at or before 18 years (only 17 of them began before 10 years old). All patients met the criteria of the International Headache Society. Russell et al demonstrated recently that the cluster headache is an inherited disorder in some families. They conclude that the gene is present in 3 to 4% of males and 7 to 10% of females with cluster headache and that it has an autossomal dominant transmission. CLINICAL CASE: The authors report the clinical case of a five year old child with cluster headache starting at three years. This paper reviews the differential diagnosis and the treatment of cluster headache.

Acetaminophen↗
PubMedDate not supplied

[Opsoclonus myoclonus syndrome: how long are we going to go on researching?].

INTRODUCTION: Opsoclonus myoclonus is a rare neurological syndrome affecting children and adults, and which is characterised by a sudden onset of chaotic eye movements and myoclonias. In children it generally appears before the age of three as a parainfectious or paraneoplasic process; the type of tumour most frequently associated with this syndrome is the neuroblastoma. CASE REPORT: We report the case of a 22 month old girl who, after a febrile syndrome probably caused by a virus, began to present myoclonias in the upper and lower limbs, opsoclonus, a marked ataxic gait and extreme irritability. After ruling out neoplasia, oral corticotherapy was started and the neurological picture gradually improved. CONCLUSION: By reporting this clinical picture, our intention is to make the particular aspects of this neurological condition known, and highlight the need for neoplasias to be detected in time and for early treatment in order to prevent sequelae, especially when it appears as a paraneoplasic syndrome.

Female↗
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[Characterization of cocoa fiber and its effect on the antioxidant capacity of serum in rats].

OBJECTIVES: The aim of this study was to characterize the physico-chemical properties of cocoa fibre (CF), to analyze its polyphenolic content and antioxidant capacity in vitro, and to investigate the effect of the administration of a polyphenolic extract of this cocoa fiber on the antioxidant capacity of the serum in rats. METHODS AND MATERIALS: Dietary fiber (DF) composition and polyphenolic (PP) content of the cocoa fiber were analyzed. The antioxidant capacity of the CF was determined by means of its reduction power (FRAP) and the capacity to scavenge free radicals (ABTS). To evaluate the bioavailability and the antioxidant capacity in vivo of the phenolic compounds of CF, an extract of these compounds was administred in the stomach of the rats with a gastric probe (100 mg PP/kg), taking blood samples at different time intervals. Sera were analyzed by HPLC to determine the presence/absence of PP or PP-metabolites. In orther to evaluate the antioxidant capacity of the serum FRAP and ABTS methods were used. RESULTS: Cocoa fiber was an excellent source of DF, with a high content of total dietary fiber (TDF), over 60% of the dry matter, made up mainly of insoluble dietary fiber (IDF; 83% of TDF). This fiber had just 1.15% of polyphenols, with low antioxidant activity. After intragastric administration of the PP-rich fraction a fast and measurable absorption of the CF polyphenols was observed, being epicatechin the main PP in blood. The absorption of this PP confers a significant, although transitory increase of the serum antioxidant capacity 10-45 minutes post-gavage; after this time, the antioxidant capacity progressively decreased reaching basal levels after 6 h. CONCLUSIONS: Cocoa fiber can be considered as an excellent source of DF, mainly insoluble dietary fiber; therefore, it could be used as an ingredient in fiber-rich functional foods. Besides the benefits derived from its high fiber content, the CF would provide protection against oxidative damage by means of its content in phenolic compounds (epicatechin) wich are absorbed maintaining the antioxidant properties in vivo.

Animals↗
PubMedDate not supplied

[Structural changes in pulmonary vessels and coronary arteries in hypoplastic left heart syndrome].

In order to correlate gross morphological features with pulmonary and coronary vasculature changes in hypoplastic left heart syndrome (HLHS) 15 heart-lung necropsy specimens from neonates were analysed. Histology of left atrium wall, lung vessels with pulmonary arteriolar disease morphometric grading, study of intra and extra pulmonary wall veins and coronary arteries were recorded. Classic HLHS was observed in 11, and DORV with mitral atresia in 4, the foramen ovale (FO) being the only left atrium outflow tract in all. All specimens had increased % of thickness and muscular extension of arterioles and increased wall thickness of pulmonary veins, but severer arteriolar and venous changes with left atrium fibrosis were noticed in 8 specimens with either closed FO (3 cases) or mean FO diameter (d) of 5 mm when compared with specimens with mean FOd of 9 mm. Coronary arteries histology disclosed in 4 of 8 specimens with opened but hypoplastic mitral valve, intima proliferative changes with lumen narrowing, not observed in 7 specimens with mitral valve atresia. We concluded that in HLHS closed or restrictive FO and permeable mitral valve may predispose neonates to respiratory complications, right ventricle abnormal function and arrhythmias, specially after cardiac surgery.

Aorta↗
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[Analysis of rearrangements in the first exon of c-myc oncogene in squamous cell carcinoma of the head and neck].

Activation of c-myc has been implicated in the origin of different human tumors, and can be produced by diverse mechanisms as amplifications or rearrangements. We examined 55 squamous cell carcinomas of the upper aerodigestive tract for rearrangements involving the first exon of c-myc, which plays a regulatory role in the c-myc expressión. Polymerase chain reaction (PCR) amplification of different fragments of c-myc exon 1 was performed using four oligonucleotide primers that correspond to consecutive sequences from the 5' end of the c-myc exon 1, combined with one oligonucleotide that corresponds to the 3' end. Amplified c-myc PCR products appear as single bands of 580, 495, 417 and 333 base pairs on the electrophoretic analysis. Only in one case a rearrangement involving the first exon of c-myc was found. We concluded that gene rearrangement is not a common mechanism of activation of c-myc in squamous cell carcinomas of the head and neck.

Adult↗
PubMedDate not supplied

[Amplification of oncogene c-erb-B1 and cellular DNA content in squamous cell carcinoma of the head and neck].

Tumoral DNA content was studied by flow cytometry and PCR amplification of c-erbB1 in tissue samples from 31 patients with squamous cell carcinoma of the head and neck. Eighteen cases (58%) were aneuploid and 13 (42%) were diploid. Aneuploidy correlated with pharyngeal site and poorly differentiated tumors, but not with clinical stage or metastases. Six (19.3%) cases had c-erbB1 amplification, which correlated with tumor size, nodal metastasis, poor differentiation, and hypopharyngeal site. Only 20% of patients with amplification survived 30 months, compared with 64% of patients without amplification. None of the patients with aneuploidy and c-erbB1 amplification survived more than 15 months. To conclude, the measurement of cellular DNA content and c-erbB1 amplification seem to have prognostic value in squamous cell carcinoma of the head and neck.

Adult↗
PubMedDate not supplied

[The relation between human papilloma virus and cellular DNA content in epidermoid carcinoma of the head and neck].

The relation between the presence of gene sequences of human papilloma virus (HPV) and the development of abnormalities in cellular DNA content was analyzed in 31 squamous-cell carcinomas of the head and neck. The integration of HPV types 16 and 6b by PCR and DNA content was studied by flow cytometry in 31 specimens from patients with squamous-cell carcinoma of the head and neck. Eighteen (58%) cases were aneuploid. HPV DNA was present in seven tumors (22.5%), five of then HPV-6b and two of them HPV-16. Aneuploidy correlated with poorly differentiated tumors. No correlation was found between HPV integration and either cellular DNA content or the degree of histological tumor differentiation. Therefore, the presence of HPV gene sequences did not seem to be associated with a higher incidence of aneuploidy in squamous-cell carcinoma of the head and neck.

Adult↗