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Biomedical subjects

G Silva

Publications and source records attributed to G Silva.

At least 37 records · Page 2Linked to original sources
PubMed1998

Caroli's disease: report of 10 cases in children and adolescents in southern Brazil.

PURPOSE: The aim of this study was to describe the authors' experience with Caroli's disease in children and adolescents. METHODS: The authors reviewed the hospital charts of 10 children and adolescents with Caroli's disease diagnosed between 1968 and 1996. RESULTS: The median age at the onset of symptoms was 5.5 months and the median age at diagnosis was 12 months, both much lower than those reported in the literature. Clinical symptoms were compatible with the classical findings of Caroli's disease, but jaundice and hepatosplenomegaly occurred more frequently. There was an association with congenital renal malformation in eight cases (80%), congenital hepatic fibrosis in five cases, and choledochal cyst in two cases. One case presented the pure form of the disease.

Adolescent↗
PubMed1998

[CHARGE association].

Posterior choanal atresia is a congenital malformation which can occur isolated or in combination to additional malformations. In CHARGE association the other anomalies are: coloboma, heart disease, retarded development/growth or central nervous system abnormalities, genital hypoplasia or hypogonadism and ear abnormalities or deafness. The authors present three cases of CHARGE association and they also review the clinical findings required for the diagnosis.

Abnormalities, Multiple↗
PubMed1997

Studies on the redox centers of the terminal oxidase from Desulfovibrio gigas and evidence for its interaction with rubredoxin.

Rubredoxin-oxygen oxidoreductase (ROO) is the final component of a soluble electron transfer chain that couples NADH oxidation to oxygen consumption in the anaerobic sulfate reducer Desulfovibrio gigas. It is an 86-kDa homodimeric flavohemeprotein containing two FAD molecules, one mesoheme IX, and one Fe-uroporphyrin I per monomer, capable of fully reducing oxygen to water. EPR studies on the native enzyme reveal two components with g values at approximately 2.46, 2.29, and 1.89, which are assigned to low spin hemes and are similar to the EPR features of P-450 hemes, suggesting that ROO hemes have a cysteinyl axial ligation. At pH 7.6, the flavin redox transitions occur at 0 +/- 15 mV for the quinone/semiquinone couple and at -130 +/- 15 mV for the semiquinone/hydroquinone couple; the hemes reduction potential is -350 +/- 15 mV. Spectroscopic studies provided unequivocal evidence that the flavins are the electron acceptor centers from rubredoxin, and that their reduction proceed through an anionic semiquinone radical. The reaction with oxygen occurs in the flavin moiety. These data are strongly corroborated by the finding that rubredoxin and ROO are located in the same polycistronic unit of D. gigas genome. For the first time, a clear role for a rubredoxin in a sulfate-reducing bacterium is presented.

Amino Acid Sequence↗
PubMed1997

Estrogenic effects of p-hydroxybenzoic acid in CD1 mice.

Xenobiotic estrogens in the environment or diet have received much attention as a possible source of certain hormonal disease states in human and wildlife. Therefore, the detection of estrogenic activity of any substance, especially those related to the food industry, is important. The estrogenic activity of p-hydroxybenzoic acid (PHBA), a compound related to a commonly used group of preservatives in food, cosmetic, and pharmaceutical preparations, was evaluated with immature and adult ovariectomized female mice (CD1) using two well-known bioassays. Subcutaneous administrations (s.c.) of different doses of PHBA were compared with estradiol (E2), and their effects on vaginal cornification and uterotrophic activities were evaluated. Different groups of animals were treated s.c. daily for 3 days with vehicle (corn oil, 0.3 ml/100 g), E2 (1 microgram/100 g), and PHBA (0.5, 5, 50, and 500 micrograms/100 g). Four days after treatment, PHBA produced a dose-dependent response on vaginal cornification and uterotrophic activity in both immature and adult ovariectomized mice. The relative uterotrophic potency of PHBA (500 micrograms/100 g) to E2 (1 microgram/100 g) was 0.0011 in immature mice and 0.0018 in ovariectomized animals.

Animals↗
PubMed1997

Analysis of the (CAG)n repeat causing Huntington's disease in a Mexican population.

We investigated the allele distribution of the polymorphic (CAG)n repeat in the IT15 gene in 96 normal subjects from the Mexican population and 83 unrelated patients with Huntington's disease. Our results show that the size distributions of normal and affected alleles do not overlap. Normal alleles range from 13 to 32 triplets, with 18 being the most frequent allele, while HD alleles contain 37 to 76 repeats with 42 being the most frequent. One allele in the range of intermediate alleles was found (32 repeats) in a normal subject. The juvenile onset cases in this study are associated with an expansion greater than 49 repeats. In the available parent-offspring pairs, paternal alleles show instability with an expansion of 28 repeats in one case.

Adolescent↗
PubMed1997

Orthotopic liver transplantation improves small bowel motility disorders in cirrhotic patients.

Altered small intestinal motility has been observed in patients with liver cirrhosis. Its pathophysiology remains to be defined. Our aim was to investigate the effect of orthotopic liver transplantation on small intestinal dysmotility in patients with liver disease. Two patients were studied both before and after orthotopic liver transplantation. Abnormal migrating motor complex activity and prominent clustered contractions present preoperatively normalized within 6 months after the surgical procedure. This finding might represent an additional benefit of liver transplantation considering that altered motility may be involved in bacterial overgrowth and infections observed in these patients.

Adult↗
PubMed1997

[Effects of pectin and cellulose on somatomedin C levels and proteoglycan synthesis rate in rat muscle and cartilage].

The inclusion of 15% pectin in a diet causes growth retardation in rats, but the mechanism for the impaired growth has not been established. Serum concentration of IGF-I and proteoglycan synthesis rate on muscle and the tibial epiphysis, an estimate of biological response to IGF-I in a target tissue, were compared in weaning rat fed with 8.5% protein and levels of 7.5 and 15% of pectin and cellulose, respectively. In experiment 1 (G1-G6) was used cellulose as source of fiber and in experiment 2 (G7-G11) pectin. A marked reduction in weight, muscle and bone growth was observed for the groups fed on 15% pectin. Plasma IGF-I concentration correlated with both protein and tibial proteoglycan synthesis rate in the group with 15% pectin diet. However, in the group fed with cellulose the most of the parameters were well maintained, with exception the group fed with beans and rice (G5 e G6). Our study suggest that the inclusion of pectin in a experimental diet impairs growth by a combination of reduced food intake, a reduced anabolic response to food due to a reduced protein and proteoglycan synthesis possibly reflecting impaired IGF-I action and secretion.

Animals↗
PubMed1996

[Experience of a single center in liver transplantation in adults and children].

Orthotopic liver transplantation (THO) is the treatment of choice for a variety of liver diseases. The national experience before 1993 has been scarce. In November 1993 we started our experience in THO at Clínica Las Condes, as part of a multiorgan transplant program (liver, kidney, pancreas). Until January 1995 we have performed 14 THO in 13 recipients (one retransplantation), of which 5 were in pediatric cases. The recipients range of age fluctuated between 1 and 61 years. In two pediatric cases a liver allograft reduction was performed. Six recipients (46%) required treatment for acute cellular rejection. One recipient had an hepatic artery thrombosis and had to be retransplanted. There was no operative mortality up to 30 days in cases of primary liver transplants. The retransplanted adult recipient, and another pediatric recipient that died from a late recurrence of a hepatoblastoma, accounted for the mortality of this experience. After an average follow up of 10 months, the actual patient survival in 85%. Of the 11 surviving recipients, 9 are in excellent conditions with a very good quality of life. This experience shows that an active liver transplant program in our country can be successful in obtaining results comparable to those published by very experienced foreign transplant centers.

Adolescent↗
PubMed1994

Splanchnic and systemic hemodynamics in early abstinence and after ethanol administration in non-cirrhotic alcoholic patients.

Thirteen asymptomatic chronic alcoholic patients were studied to investigate the early stages of portal hypertension in alcoholic liver disease and the effects of withdrawal and ethanol on hepatic function and hemodynamic variables. None of the patients presented clinical signs of decompensated liver disease, and their liver biopsies showed normal liver or moderate alterations only. In basal conditions and after an intravenous ethanol infusion (1 g/kg body weight), hepatic venous pressure gradient and hepatic blood flow using indocyanine green were measured through hepatic vein catheterization. Hepatic sinusoidal vascular resistance and indocyanine green intrinsic clearance were also calculated. Portal blood flow measurements were obtained by Doppler ultrasound. No correlation was observed between hepatic venous pressure gradient and histologic features, (steatosis, necrosis, fibrosis, inflammation and hepatocyte surface area). In basal conditions, portal hypertension was not found in any case. After ethanol, portal pressure increased significantly (p < 0.001); in four cases it rose to or above 5 mmHg. Portal blood flow, hepatic blood flow and hepatic vascular resistance also increased significantly. Intrinsic indocyanine green clearance decreased slightly but significantly. No significant correlations were found between portal pressure, hepatic resistance and the histologic parameters. It was concluded that alcoholic patients, without clinical or laboratory evidence of liver failure and with minimal or moderate histologic alterations, have normal portal pressures. After an intravenous ethanol load, however, four out of 13 patients (31%) reached levels of 5 mmHg or more, irrespective of their liver histology.

Adult↗
PubMed1993

Anticoagulant and estrogenic effects of two new 17 beta-aminoestrogens, butolame [17 beta-(4-hydroxy-1-butylamino)-1,3,5(10)-estratrien-3-ol] and pentolame [17 beta-(5-hydroxy-1-pentylamino)-1,3,5(10)-estratrien-3-ol].

The syntheses and characterizations of two new 17 beta-aminoestrogens, butolame [17 beta-(4-hydroxy-1-butylamino)-1,3,5(10)-estratrien-3-ol] and pentolame [17 beta-(5-hydroxy-1-pentylamino)-1,3,5(10)-estratrien-3-ol], are presented. Both compounds, when administered in single subcutaneous injections to male mice and rats, produce dose-dependent increases in blood clotting times that may last several days. The estrogenic effects assessed by the vaginal cornification test are of relatively short duration.

Amino Alcohols↗
PubMed1993

[Prediction of histological liver damage in asymptomatic alcoholic patients by means of clinical and laboratory data].

Looking for a noninvasive method to predict liver histologic alterations in alcoholic patients without clinical signs of liver failure, we studied 187 chronic alcoholics recently abstinent, divided in 2 series. In the model series (n = 94) several clinical variables and results of common laboratory tests were confronted to the findings of liver biopsies. These were classified in 3 groups: 1. Normal liver; 2. Moderate alterations; 3. Marked alterations, including alcoholic hepatitis and cirrhosis. Multivariate methods used were logistic regression analysis and a classification and regression tree (CART). Both methods entered gamma-glutamyltransferase (GGT), aspartate-aminotransferase (AST), weight and age as significant and independent variables. Univariate analysis with GGT and AST at different cutoffs were also performed. To predict the presence of any kind of damage (Groups 2 and 3), CART and AST > 30 IU showed the higher sensitivity, specificity and correct prediction, both in the model and validation series. For prediction of marked liver damage, a score based on logistic regression and GGT > 110 IU had the higher efficiencies. It is concluded that GGT and AST are good markers of alcoholic liver damage and that, using sample cutoffs, histologic diagnosis can be correctly predicted in 80% of recently abstinent asymptomatic alcoholics.

Adult↗
PubMed1993

[Hemodynamic and functional hepatic effects of isosorbide-5-monitrate in cirrhotic patients with portal hypertension].

Isosorbide 5-mononitrate reduces portal pressure in acute conditions. The aim of this work was to assess its effects and tolerance development after 30 days of use in alcoholic cirrhotic patients without history of variceal bleeding. Nine patients with portal hypertension (7 with esophageal varices) were studied. Hepatic and systemic hemodynamic parameters were measured in basal conditions, after one hour and after 30 days of treatment (40 mg b i d). One patient was lost from control at 2 weeks. In the total group, portal pressure decreased from 15.1 +/- 3.7 mm Hg to 12.1 +/- 5 at one hour and 11.3 +/- 5.5 mm Hg at 30 days (p < 0.002). In two patients, portal pressure was not modified. Portal blood flow increased significantly at one hour in the 7 responder patients. Hepatic blood flow (indocyanine green clearance) was not modified; thus, estimated hepatic resistance decreases in both periods. Intrinsic indocyanine green clearance (a measure of hepatic function) did not change in any period. Systemic blood pressure decreased and cardiac rate increased only after one hour. The fall in portal pressure did not correlate with changes in portal or hepatic blood flow. It is concluded that isosorbide 5-mononitrate decreased portal pressure in 7 out of nine patients, even after 30 days of treatment, without untoward effects over hepatic function or perfusion.

Adult↗
PubMed1992

[Controlled study of the effect of silymarin on alcoholic liver disease].

A controlled trial on the use of Silymarin in patients with alcoholic liver disease was performed. Seventy two patients were admitted to the trial and randomly assigned to an experimental or controls group. Experimentals received 280 mg/day of Silymarin and controls an equal number of placebo tablets. Three patients on placebo and nine on Silymarin were lost from control (p = 0.035), remaining in control 34 patients receiving placebo and 25 patients receiving the drug. Both groups did not differ in their initial laboratory assessment and were followed up for an average of 15 months. Ten patients died during the follow up (5 in placebo and 5 in Silymarin); life table analysis did not show significant differences in mortality. Patients who died had lower serum albumin and prothrombin time and higher total bilirubin, alkaline phosphatases and CCLI on the initial clinical and laboratory assessment. Final laboratory values and their changes in those who survived did not differ between Silymarin and placebo. Twenty two patients on placebo (65%) and 14 on Silymarin (58%) recognized alcohol ingestion or had a positive urine sample analysis for alcohol during follow up. Those who abstained from alcohol had a significant fall in gamma glutamyl transferase during follow up. No other significant differences were observed between these two groups. It is concluded that in this trial, Silymarin did not change the evolution or mortality of alcoholic liver disease.

Double-Blind Method↗