Search PubMed⌕ Search

Biomedical subjects

R Barrios

Publications and source records attributed to R Barrios.

At least 73 records · Page 4Linked to original sources
PubMedDate not supplied

[Colonic polyps: an analysis of the endoscopic and histopathological aspects].

The present study is a retrospective analysis of the endoscopic and histologic features of 728 polyps resected from 422 patients during the years 1980 to 1991. Mean age of the patients was 52 years (5 to 87), 63% male and 37% female. The histology of the lesions showed: adenoma: 60.3%, hyperplastic: 31.7; juvenile: 2.3% and miscellaneous: 5.7%. The 439 adenomas where found in 270 patients of which 151 (55.9%) were male and 119 (44.1%) female. The 231 hyperplastic polyps where found in 113 patients: 66 (58.4) male and 47 (41.6) female. All the hyperplastic polyps where less than 20 mm in diameter. Of the adenomas, 385 (87.7%) where less than 20 mm in diameter and had macroscopic appearance similar to the hyperplastic polyps. Of the 439 adenomas, 218 (49.6) where pediculated and 221 (50.4%) sessile. Of the hyperplastic polyps 53 (22.9%) where pediculated and 178 (77%) sessile. Of the adenomas, 351 (80%) where tubular and 88 (22%) had a villous component, most of the tubular adenomas where less than 15 mm in diameter and the villous component was more frequent as the polyps increased in size. Of the adenomas, 139 (30%) had dysplasia and of these 10% had cancer which represents a total of 3% of all the adenomas in this series. The grade of dysplasia was more severe as the adenomas was larger in size or had villous component. The polyps were located: 69.6 in the distal colon at the reach of the flexible sigmoidoscope and 30.4% in the proximal colon.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Analysis of rheumatic valvulopathy with scanning electron microscopy].

There is a high incidence of rheumatic endocarditis in our environment. Therefore it is important to know the structural characteristics of the valvular lesions in order to better understand the physiopathologic pathways of tissue injury. We have chosen a non-conventional method, the scanning electron microscopy. There were very few such reports in the current literature. We analyzed ten mitral valve with rheumatic scarring lesion and five normal, as a control group. We were able to establish three structural patterns. 1) Stone pavement like (endocardium with nuclear bulge cells and marginal folds at the cell boundaries, abundant number of microvillous projections and few areas of endothelial loosening). 2) Cerebroid (subendothelium with wrinkles caused by deformity of the valve with or without endothelial loosening) and 3) Smooth pattern (flattened endothelium with scanty microvillous projections and abundant areas of endothelial denundation and exposition of subendothelium). More damage was noted in the auricular surface of the rheumatic group, characterized by a predominance of the smooth pattern. We found Lambl's excrecences in two mitral leaflets, they were formed by collagen break fascicles of the subendothelium. This technique allowed us to analyze integrity of the endocardial selective barrier and the interactions between the damaged surface of the valve and elements of the peripheral blood and showed more endocardial injury in the rheumatic group. These alterations could play an important role in the pathogenesis of this disease.

Adult↗
PubMedDate not supplied

[Multi-technical management of biliary fistula].

Biliary fistula is an occasional complication of cholecystectomy and are usually associated to retained biliary stones, surgical trauma of the biliary ducts and local infection. They were mainly treated by surgical methods up to the acquisition of the new endoscopic and percutaneous techniques used together with parenteral and enteral nutrition and new antibiotics. A total of seven patients with diagnosis of biliary fistula were seen between 1984 and 1990 at the "Unidad de Gastroenterología y Cirugía Digestiva" of the Clínica Sanatrix en Caracas. Average age was 50 with ranged between 31 and 76, 4 were male and 3 female. The fistulas were in 1 due to necrotizing pancreatitis, in 3 to lost of the ligation of the cystic duct, 2 were due to accidental injury of the common duct and the last case was a partial dehiscence of a choledoco-jejunostomy after the resection of a common duct cyst. Four of the cases were choledoco-cutaneous fistula, one hepatocutaneous, two hepatoduodenal. All the seven patients had subhepatic collections, one had a retroperitoneal collection, two had subdiaphragmatic collections and one had multiple hepatic abscesses. The abdominal collections were treated by percutaneous drainage using mainly the Ring-McLean and Van Sonnenberg tubes. The fistula was occluded with biliary prosthesis in four cases, using either endoscopic, percutaneous or mixed technique to place the stent. Patency of the stents ranged between 2 weeks and 24 months. Control time was from 2 to 40 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Mast cells and idiopathic lung fibrosis.

Mast cells are usually related with allergic reactions in the lung. This cells has a biochemical repertoire capable of modulate inflammatory reactions in this organ. The relation of this cell with idiopathic pulmonary fibrosis (IPF), has not been studied in depth. There is no agreement in which is the best technique for counting mast cells and what are the normal counts of these cells in the lung. We analyse some of the reported "normal values" and the differences within IPF and patients with nonfibrotic lung diseases. The results of the present study demonstrate that the largest population of mast cells in IPF patients were the interstitium (342 +/- 83 cells) compared with the nonfibrotic patients (31 +/- 8 cells), and almost equal in both groups of patients in the subpleural, peribronchiolar and perivascular areas. However, it is necessary to unify criteria, in order to define what the normal values for mast cells in the lung are.

Adolescent↗
PubMedDate not supplied

[The effect of gelfoam embolism in vascular conduction and critical pressure in the isolated canine lobe].

Pulmonary pressure-flow curves, hemodynamic and blood gas parameters in West's zone II condition were obtained in nine isolated in situ left lower lobes (LLL) before (condition A), and after 15, 30 and 60 minutes of lobar gelfoam embolization (GE) (condition B) in order to know the natural history of this model. After GE a decrease in PaO2 and lobar O2 were noticed (p less than 0.05). Vascular conductance (p less than 0.001) and lobar blood flow decreased (p less than 0.05), accompanied by a significant increase in the inflow (p less than 0.01) and in the mean closing pressures (p less than 0.01). These parameters did not change during the time of observation at condition B. Nor the cardiac output or the minimal closing pressure changed in relation to condition A. LLL angiographic findings showed evidence of arterial occlusion and the pattern of obstruction was not homogeneous. Lobes histology showed occluded arteries of more than 300 micrometers of diameter. We concluded that in this canine model of increased pulmonary vascular resistance, pulmonary vascular conductance and mean closing pressure change, remain stable during 60 minutes after GE allowing us to know the natural history of the preparation. Condition than allow to perform and evaluate other interventions on lung vascular mechanics in the experimental setting of pulmonary embolization.

Animals↗
PubMedDate not supplied

[Routine preoperative cholangiopancreatography?].

Since the early 50s, the routine use of operative cholangiography in biliary surgery has decreased the rate of negative choledochotomy and retained stones. In the last twenty years no further progress has occurred and negative choledochotomy rate remains at 30% and for retained stones at 1.3%. Modern endoscopic technology has improved the diagnosis and treatment of biliary diseases so we think that the routine use of endoscopic retrograde cholangiopancreatography (ERCP) as a preoperative study for patients to be surgically treated of biliary disease can reduce the incidence of negative choledochotomies, retained stones and duodenostomies that are the most important sources of biliary surgery complications. The results of ERCP as routine preoperative study in patients with diagnosis of symptomatic gallstones selected for surgical treatment are discussed. From June 1988 to June 1989 56 patients who filled the requirements were included. Ultrasound scan, laboratory test. EKG and complete digestive studies were performed at admission. ERCP was done immediately before surgery. Abnormalities on biliary tract were seen in 10 cases (17.9%). Six (10.7%) had stones in the common duct, in 4 of these patients (7.1%) the lithiasis was unsuspected, Four cases (7.1%) had dilated ducts, three of them with narrowing of the distal end of the choledochus. In 5 cases with duct stones and 3 with dilated ducts an endoscopic sphincterotomy was performed at the same time of the study, stones were withdrawn and biliary system cleared before laparotomy. Only one choledochotomy was done in a patient with a carcinoma of the gallbladder and a big stone impacted in cystic duct that produced compression of the common bile duct (Mirizzi Syndrome).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

[Cardiovascular abnormalities in Ehlers-Danlos syndrome. Report of a case].

This is the case of a 34-year-old woman with Ehlers-Danlos syndrome whose cardiopulmonary manifestations are the following: Prolapse of mitral and tricuspid valves. Aneurysmal dilatation of main arteries without aortic or pulmonary insufficiency. Disturbances in pulmonary function tests and pulmonary arterial hypertension. The diagnosis was verified by skin biopsy and an electron microscopic study. Due to the clinical and histopathological characteristics, we have considered this case to be a non-specified type of the 10 varieties described up to now, and have decided to report it also because of the interesting findings in the hemodynamic and pulmonary function tests.

Adult↗
PubMedDate not supplied

[A change in glomerular permeability in renovascular hypertension. Participation of angiotensin and structural lesions].

To characterize the decrease in glomerular permeability that occurs in contralateral kidney of renovascular hypertension, glomerular hemodynamics were studied in Goldblatt hypertensive and normotensive control rats. The effects of converting enzyme inhibition (captopril) and renal vasodilatation induced with hyperoncotic plasma were evaluated: in addition, glomerular morphometry was performed. In hypertension, glomerular capillary pressure was increased, ultrafiltration coefficient was decreased, single-nephron filtration rate was normal and afferent resistance was elevated. Captopril rose glomerular filtration rate only in normotensive rats, but ultrafiltration coefficient increased in both groups. Hyperoncotic plasma induced a 98% increment in filtration rate and ultrafiltration coefficient rose by 48% in normotensive group. In hypertensive rats, filtration rate increased only 15% and ultrafiltration coefficient diminished 6%, morphometric studies showed dilatation of capillary loops and a larger glomerular volume. Similar response to captopril in both groups of rats suggest that the reduction in ultrafiltration coefficient in hypertension is not dependent of angiotensin; lack of response to hyperoncotic plasma suggests that it could be produced by structural changes in capillary wall that diminish hydraulic permeability since the larger glomerular volume indicates a greater area for filtration.

Angiotensin II↗
PubMedDate not supplied

[Pulmonary blood volume in patients with interstitial pneumopathy and pulmonary heart disease. Its study at rest and during exercise].

Pulmonary blood volume (PBV) measurements have been reported in chronic lung disease that do not include diffuse interstitial lung disease (ILD) and cor pulmonale (CP). In this study, PBV was measured using the double injection single sampling method, at rest and at exercise in ten patients with ILD due to extrinsic allergic alveolitis (n = 6) or usual interstitial pneumonia (n = 4). Lung biopsies were obtained in 8 patients, and in none of them the stage of fibrosis was predominant over inflammation. The degree of vascular lesions was in four patients grade I and in four grade II (Heath-Edwards classification). At rest, most of the patients had elevated mean pulmonary artery pressure (PAP) and vascular resistance (PVR), (mean PAP 30 +/- 4 mmHg and 336 +/- 171 d.s. cm.-5, respectively), hypoxemia (paO2 = 48 +/- 2 mmHg) and a severely reduced PBV (53.6 +/- 11 ml.s.qm.). At exercise, pulmonary arterial hypertension worsened and, although PBV value increased significantly (rest = 53.6 +/- 11.6 ml.m2, s.qm. exercise 132 +/- 28 ml.s.qm.p less than 0.01) it remained abnormally low with respect to normal value. Comparison of the mean intravascular pressure-PBV measurements relationship in different lung diseases showed that ILD patients with CP have the greatest abnormality. Possible explanations for the severe reduction in PBV include restriction of extra-alveolar vessels as a consequence of lung volume loss, restriction of intra-alveolar vessels due to structural and functional changes imposed by the inflammation-fibrosis process and vascular restriction due to vasoactive factors (alveolar hipoxia).

Adult↗
PubMedDate not supplied

[Classical interstitial pneumonitis and mixed cryoglobulinemia in a male with Turner phenotype. Report of a case and review of the literature].

We report a male patient, chromosomal complement 44 XY with Turner's phenotype, who has multiple skeletal, genitourinary and mild cardiac abnormalities, without hypogonadism. This patient developed a diffuse infiltrative pulmonary disease which result in pulmonary fibrosis, respiratory insufficiency and cardiac failure. He has also mixed cryoglobulinemia (Type III) with antigammaglobulin antibodies. The relationship among these problems and his phenotype is discussed. Apparently there is only a coincidental association.

Adult↗
PubMedDate not supplied

[Pulmonary eosinophilia and pulmonary arterial hypertension].

Pulmonary artery hypertension is a rare feature in the eosinophilic pulmonary syndrome, it had been observed only in some cases of tropical pulmonary eosinophilia. A case of prolonged pulmonary eosinophilia with reversible pulmonary hypertension is presented.

Humans↗
PubMedDate not supplied

[Ultrastructural observations on experimental shock lung].

Intercellular junctions in the alveolar epithelium and in the capillary endothelium in the dogs after hemorrhagic shock (mean BP 40 mm Hg for 3 hours) and from control dogs were observed in the electron microscope using the freeze-fracture and etch technique. Following shock, tight junctions (zonulae occludentes) in the alveolar epithelium which were well developed with may strands in control animals showed alterations in substructure. Some desintegration and disappearance of junctional strands in "focal" regions were occasionally observed in the endothelium as well. The increased pulmonary capillary permeability observed physiologically after hemorrhagic shock may be explained by such alterations of endothelial zonulae occludentes.

Animals↗