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Biomedical subjects

G Ramos

Publications and source records attributed to G Ramos.

At least 37 records · Page 2Linked to original sources
PubMed1997

Assay for erythrocyte superoxide dismutase activity in patients with lung cancer and effects on pollution and smoke trace elements.

The antioxidative effect of CuZnSOD, which catalyzes the dismutation of superoxide anion (O2-), provides a defense against the oxygen toxicity. The object of the study is to evaluate the erythrocytes superoxide dismutase (SOD) activity in two groups of persons (Group I, healthy blood donors; Group II, lung cancer patients), using the spectrophotometric assay of NADH oxidation and the indirect method. The effect of trace elements, such as Al3-, Cr3+, Fe3+, Hg2+, NI2+, and Pb2+ (producing free radicals oxygen and present in pollution and smoke) is also evaluated. The results show the decrease of SOD activity in lung cancer patients with respect to healthy individuals. Likewise, in those patients the enzymatic activity is bigger in early stage (I,II) with respect to advanced one (III) (p < 0.05). The lesser activity when the samples are incubated with Ni or Pb point out that these metals play a role in neoplasm development. In short, the oxidant-antioxidant balance is altered in lung cancer patients.

Adenocarcinoma↗
PubMed1997

Early complications in surgical treatment of lung cancer: a prospective, multicenter study. Grupo Cooperativo de Carcinoma Broncogénico de la Sociedad Española de Neumología y Cirugía Torácica.

BACKGROUND: We prospectively analyzed the postoperative morbidity, mortality rate, and risk factors in 605 patients who underwent thoracotomy for bronchogenic carcinoma. METHODS: Patients were categorized by postsurgical tumor stage: I, 287 patients (47.4%); II, 49 patients (8.1%); IIIA, 154 patients (25.5%); IIIB, 80 patients (13.2%); IV, 16 patients (2.7%); unavailable, 19 patients (3.1%). Two hundred ninety-four patients (48.6%) underwent lobectomy, 172 (28.4%) pneumonectomy, 20 (3.3%) bilobectomy, 29 (4.8%) segmentectomy, 27 (4.5%) wedge resection, and 63 (10.4%) exploratory thoracotomy. The importance of the factors that influence the morbidity and mortality rates was calculated from their relative risks. Univariate and multivariate methods for a logistic regression model were used for this analysis. RESULTS: Postoperative complications developed in 196 patients (32.4%); there were 165 (27.3%) cases of operation-related complications and 152 (25.1%) cases of respiratory and cardiovascular complications. The morbidity rate was highest in patients with preexisting vascular disease (50.9%; odds ratio [OR], 2.20) or insulin-dependent diabetes mellitus (52.4%; OR, 2.77) and in patients who underwent pneumonectomy (40.1%; OR, 1.82). Forty patients (6.6%) died postoperatively, most commonly of respiratory failure (67.5%). The mortality rate was highest in patients with postoperative morbidity (OR, 31.9) or vascular disease (15.8%; OR, 2.83) and in patients who underwent pneumonectomy (13.4%; OR, 4.9). CONCLUSIONS: Postoperative complications are more likely to develop in patients with peripheral vascular disease or insulin-dependent diabetes mellitus, or both. Postoperative mortality was found to be significantly higher in patients with vascular disease and those who underwent pneumonectomy.

Aged↗
PubMed1996

Protective effect of a platelet-activating factor antagonist (WEB-2086) in postischemic renal failure.

The purpose of this study was to evaluate the renoprotective effect of a specific platelet-activating factor antagonist (WEB-2086) in an experimental model of normothermic renal ischemia. Twenty New Zealand white rabbits were studied for 2 days before and 24 hours after a 60-minute period of renal ischemia induced by bilateral clamping of the renal arteries. The animals were divided into two groups: a control group (group A; n = 10) and a treated group (group B; n = 10). In group A the urinary flow rate decreased significantly (from 0.098 +/- 0.008 ml/min to 0.029 +/- 0.005 ml/min) (p < 0.001) and there was a significant reduction in creatinine clearance (from 11.4 +/- 1.2 ml/min to 3.4 +/- 1.1 ml/min) (p < 0.001). In group B no significant changes were observed, although the urinary flow rate increased even in the postischemic period (from 0.09 +/- 0.008 ml/min to 0.11 +/- 0.02 ml/min). Microcirculatory cortical flow showed a postischemic reduction in both groups, although it was most significant in the control group (group A = 43.7%, group B = 71.5%; p < 0.001). Histologic study showed mild damage with patchy tubular necrosis in both groups, although this injury was less severe in the treated group. The results suggest that the preoperative administration of WEB-2086 produces a potent diuretic effect with significant attenuation of postischemic acute renal failure.

Acute Kidney Injury↗
PubMed1996

Epidural regional hypothermia for prevention of paraplegia after aortic occlusion: experimental evaluation in a rabbit model.

PURPOSE: The efficacy of epidural regional hypothermia in the prevention of acute and delayed-onset paraplegia, as well as possible complications and limitations of this technique to a clinically acceptable form, were evaluated in 49 New Zealand white rabbits. METHODS: A modified rabbit spinal cord ischemia model of infrarenal aortic occlusion for 30 minutes was employed. The study was performed in two phases. In phase I (n=20), regional hypothermia induced by epidural perfusion of iced normal saline solution (4 degrees C) was tested versus control in 10 rabbits each (groups A and B). In phase II (n=29) the animals were subdivided into three groups to study the kinetics of absorbtion and distribution of methylene blue (group C; n=10), radiographic contrast material (group D; n=9), and measurement of cerebrospinal pressure while an epidural iced solution was or was not infused (group E; n=10). RESULTS: At 24 and 48 hours, all of the normothermic animals showed irreversible paraplegia (Tarlov score 0). In contrast, at 24 hours none of the rabbits undergoing epidural cold infusion were paraplegic, although at 48 hours one animal had weakness of a hindlimb (Tarlov score 3). Plasma concentration-time profiles of a continuous epidural perfusion with methylene blue showed that the spinal canal is a highly compliant space. Epidurographs showed that epidural perfusion tends to spread more in a cephalic than caudal direction and the main uptake is by the vascular compartment. Despite the large volumes infused (78.75 ml/hr; range, 50 to 100 ml), we observed only a modest transient increase in cerebrospinal fluid pressure (from 2.5 +/- 0.3 mm Hg to 5.4 +/- 0.1 mm Hg), although some animals had intracranial hypertension. CONCLUSIONS: Regional hypothermia induced by epidural cold perfusion has a highly protective effect against the ischemic spinal cord damage. However, this method probably does not avoid the risk of delayed-onset paraplegia. An important limitation of this technique is the difficulty of controlling the intrathecal pressures.

Animals↗
PubMed1995

[Anesthetic management of labor in a pregnant woman with myocardial infarction].

Given the rarity of acute myocardial infarction (AMI) in parturients, we report the case of a 29-years-old woman who suffered 2 AMIs related to her 2 pregnancies. In our patient, the anesthetic technique chosen for the second birth, which was vaginal, was epidural analgesia with invasive hemodynamic monitoring. No complications occurred during the birth or the perinatal period.

Adult↗
PubMed1995

[Cervical epidural anesthesia for carotid mycotic aneurysms].

Extracranial mycotic aneurysms of the carotid are unusual. We present such an aneurysm of the right primary carotid caused by enteritis due to Salmonella in a 75-year-old patient at high risk for surgery (myocardial ischemia evolving over 3 months) and with coexisting stenosis of 75% of the left internal carotid. Endarterectomy of the left internal carotid, with shunting, was performed, after which the right primary carotid was tied during the same operation. Epidural anesthesia to C6-C7 was provided through a catheter supplemented with an intravenous propofol infusion. Neurological and hemodynamic variables monitored during surgery were stable. No neurological deficits or myocardial ischemic changes were recorded. Three months after discharge the patient was asymptomatic.

Aged↗
PubMed1994

Lateness of diagnosis of oral and oropharyngeal carcinoma: factors related to the tumour, the patient and health professionals.

The risk of presenting with advanced stage vs. early stage disease was evaluated in a prospective study of 336 consecutive patients with oral and oropharyngeal carcinomas referred to three head and neck surgery services in Sao Paulo, Curitiba and Goiania during the period from February 1986 to December 1988. Income and educational levels were not associated with stage distribution. The risk of having advanced disease was dependent upon male gender. Another important determinant of advanced stage was tumour location on the less visible surfaces of the oral cavity and oropharynx. Although there was a clear increase in delay of referral among cases who were seen by more than one health professional, duration of symptoms and patient and professional delays were not associated with the risk of advanced disease in unifactorial analysis. The following factors were independently associated with the risk of advanced disease for lip carcinoma: a painful ulcer, alcoholism and delay caused by a non-specialist medical doctor. The risk factors associated to advanced oral carcinoma were: type of lesion, odynophagia/dysphagia, delay caused by a dentist and delay caused by a non-specialist medical doctor. Two of the most important immediate consequences of advanced stage were a conspicuous increase in treatment costs and a longer hospital stay.

Adolescent↗
PubMed1994

Malnutrition as a prognostic factor in lymphoblastic leukaemia: a multivariate analysis.

One hundred and twenty eight Brazilian children with lymphoblastic leukaemia were intensively treated with a Berlin-Frankfurt-Munich based protocol. More children had a white cell count above 50 x 10(9)/l (31%) then observed in developed countries. After a median follow up of 31 months (11-58 months), the estimated probability of relapse free survival was 41% (7%) for the whole group. After adjustment in the Cox's multivariate model, malnutrition was the most significant adverse factor affecting duration of complete remission. Age above 8 years and high peripheral white cell count were also significant adverse factors. Among the nutritional indices, the height for age and weight for age z scores were both significant, whether the cut off points of z-2 or z = -1.28 were chosen to define malnutrition. A strong statistical association between the two indices was found; the contribution of height for age z score to the prediction of relapse free survival was more significant. Children with height for age z score < -2 had a relapse risk of 8.2 (95% confidence interval 3.1 to 21.9) relative to children with z score > -2. The results of this study suggest that socioeconomic and nutritional factors should be considered in the prognostic evaluation of children with leukaemia in developing countries.

Adolescent↗
PubMed1994

Effects of vertebral axial decompression on intradiscal pressure.

The object of this study was to examine the effect of vertebral axial decompression on pressure in the nucleus pulposus of lumbar discs. Intradiscal pressure measurement was performed by connecting a cannula inserted into the patient's L4-5 disc space to a pressure transducer. The patient was placed in a prone position on a VAX-D therapeutic table and the tensionometer on the table was attached via a pelvic harness. Changes in intradiscal pressure were recorded at resting state and while controlled tension was applied by the equipment to the pelvic harness. Intradiscal pressure demonstrated an inverse relationship to the tension applied. Tension in the upper range was observed to decompress the nucleus pulposus significantly, to below -100 mm Hg.

Adult↗
PubMed1994

Hemodynamic and cerebral repercussions arising from surgical interruption of the superior vena cava. Experimental model.

This study was designed to analyze the hemodynamic and cerebral repercussions arising from the surgical interruption of the superior vena cava. The experiments were carried out in 12 mongrel dogs under two different conditions: with shunt (group A, n = 6) and without the installation of a shunt (group B, n = 6). The period of occlusion was 35 minutes. The right atrium pressure, pulmonary arterial pressure, and aortic pressure are not significantly modified in the two groups. The intracranial pressure had an important correlation with the central venous pressure (r2 = 0.8572). In group B, the intracranial pressure had a sharp increase between the basal period (6.9 +/- 1.47 mm Hg) and the clamping superior vena cava (17.2 +/- 1.05 mm Hg), accentuated with the interruption of the azygous vein (32.2 +/- 0.7 mm Hg). In group A, the use of a shunt avoided this alteration during clamping of the superior vena cava (6.8 +/- 2.0 mm Hg) and the azygous vein (8.0 +/- 2.24 mm Hg). However, after removal of the clamps in group B, an elevated residual intracranial pressure was observed (21.1 +/- 3.33 mm Hg) in contrast to the central venous pressure, which returned to the basal values (4.4 +/- 0.7 mm Hg). The biomechanic findings of the volume-pressure curves (with Miller and Marmarou-Shapiro tests) and the cerebral necropsy showed brain damage in group B, without the shunt. Three animals had areas of hemorrhagic infarction. Histologic study demonstrated signs the incipient vasogenic edema. In group A, all findings were compatible with the normal. In conclusion, these results suggest the importance of shunting the blood in those cases of a nonobstructed superior vena cava because the clamping and reconstruction produce hemodynamic compromise and brain damage.

Analysis of Variance↗
PubMed1994

[Myocardial infarct during pregnancy. Treatment of the acute phase and of labor. Apropos a case and a review of the literature].

An acute myocardial infarction, is an infrequent complication in pregnant women. We present the case of a 29-years-old patient who suffered 2 acute myocardial infarction in relation with her two pregnancies. The first acute myocardial infarction occurred the third day after delivery, and the second, during the seventh month of the second pregnancy. In the latter, delivery was vaginal, with epidural anaesthesia. A coronary angiogram showed coronary arteries without significant narrowings, as well as an aneurysm of the left ventricle. A review of the literature published so far is made in the discussion.

Acute Disease↗
PubMed1991

[Thoracopleuromyoplasty as definitive cure for chronic pleural empyemas, after preparation by open thoracostomy].

Between 1979 and 1986, 30 patients with chronic pleural empyema (19 with pyothorax secondary to tuberculosis and 11 with pleural empyema following pulmonary resection) underwent two-stage treatment. The first stage consisted of open thoracostomy and was followed, 2 to 7 months later, by thoracopleuromyoplasty with latissimus dorsi, serratus anterior and pectoralis major muscles either alone or in combination. There was no operative mortality in this series of 30 operated patients. Definitive obliteraion of the pleural cavity and closure of the bronchial fistulae were obtained in 26 of the 30 patients. Partial necrosis of the muscle graft in the other 4 patients required further open drainage and an additional myoplasty. The long-term functional results in the cases of post-resection empyema were compatible with the restriction created by the pulmonary resection and, in the cases of empyema with a residual lung, with the restriction of the volume and perfusion of pulmonary parenchyma.

Adolescent↗
PubMed1989

[Gamma-glutamyltranspeptidase activity and glutathione content in the mammary gland during the processes of pregnancy and lactation in chronically malnourished rats].

The influence of early and chronically dietary protein and energy restriction on gamma glutamyl transpeptidase (GGTP: E.C.2.3.2.2.) activity of the mammary gland of pregnant and lactating rats, was studied. Rats fed a restricted amount of a 25% casein diet throughout gestation and lactation decreased mammary gland weight, DNA, and protein content. The GGTP activity in the mammary gland of the malnourished group was significantly decreased during all of the experimental trial period, and a decrease of offspring weight gain was also observed in that group. The inhibition of GGTP activity in the mammary gland caused by effects of maternal protein and energy undernutrition, could have depressed mammary uptake of amino acids, suggesting a reduced milk protein content and/or milk output.

Animals↗