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Biomedical subjects

V Vargas

Publications and source records attributed to V Vargas.

At least 73 records · Page 4Linked to original sources
PubMed1992

Evaluation of anti-HCV positive blood donors identified during routine screening.

Of 30,231 donors tested, 368 (1.2%) were anti-HCV positive. Of these, 254 have been evaluated, with the following results: only 25% have a history of parenteral risk, seroprevalence increases with age and approximately 80% of those that are anti-HCV positive in our population are probably infected with HCV. In addition, an unexpectedly large number of these persons have chronic and/or severe liver disease and will require combined diagnostic approaches for accurate evaluation.

Age Factors↗
PubMed1992

[Treatment of acute secretory diarrhea with casein: an effect of beta-casomorphins?].

A patient with acute secretory diarrhea refractory to conventional therapy received calcium caseinate as sole nutrient, based on the recognized development of constipation and fecaloma in patients receiving this agent. Complete remission of diarrhea followed within 10 days. An inhibition of intestinal motility mediated by B-casomorphins released after hydrolysis of casein in the intestinal tract may be the mechanism involved in this effect. These exorphins have varying effects upon the opioid receptors of the intestinal tract.

Acute Disease↗
PubMed1991

[Primary solid hepatic sarcoma. Diagnosis by cytological puncture].

The clinical case of a 56 year old patient who developed a grafted hepatic tumoration on a year after diagnosis of liver cirrhosis of alcoholic etiology is reported. Diagnosis of the mass was made by fine needle aspiration punction ecographically guided obtaining a cellular block which, upon anatomopathological study, revealed the presence of a malignant mesenchymal tumor; a leiomyosarcoma. Not only is this type of primary hepatic tumor rare but its appearance on a liver of alcoholic cirrhosis is also of interest. It is much more common to find primary hepatic tumors of epithelial origin, concretely hepatocarcinomas. The value of this finding is discussed with the importance of the ecographically guided punction enabling the establishment of a precise histological diagnosis being underlined. The prognosis of malignant hepatic mesenchymal tumors is commented upon as well as the long survival associated to the same, which, in this case, was longer than 18 months.

Biopsy, Needle↗
PubMed1991

Paracentesis with intravenous infusion of albumin as compared with peritoneovenous shunting in cirrhosis with refractory ascites.

BACKGROUND: There is no satisfactory treatment for refractory ascites in patients with cirrhosis. Both peritoneovenous shunts and paracentesis have been used, but there is uncertainty about their relative merits. METHODS: We studied 89 patients with cirrhosis and refractory ascites who were randomly assigned to receive either repeated large-volume paracentesis plus intravenous albumin or a LeVeen peritoneovenous shunt. Patients in the paracentesis group in whom recurrent tense ascites developed during follow-up were treated with paracentesis, and those in the peritoneovenous-shunt group with diuretic agents or by the insertion of a new shunt if there was shunt obstruction. RESULTS: During the first hospitalization, ascites was removed in all 41 patients in the paracentesis group and in 44 of the 48 patients in the peritoneovenous-shunt group. The mean (+/- SD) duration of hospitalization in the two groups was 11 +/- 5 and 19 +/- 9 days, respectively (P less than 0.01). There were no significant differences in the number of patients who had complications or died. During follow-up, 37 patients in each group were hospitalized again. In the paracentesis group, the number of rehospitalizations for any reason (174 vs. 97 in the peritoneovenous-shunt group) or for ascites (125 vs. 38) was significantly higher, and the median time to a first readmission for any reason (1 +/- 1 vs. 2 +/- 2 months) or for ascites (2 +/- 2 vs. 8 +/- 17 months) was significantly shorter than in the peritoneovenous-shunt group. The total times in the hospital during follow-up, however, were similar in the two groups (48 +/- 49 and 44 +/- 39 days, respectively). Three patients had obstructions of their peritoneovenous shunts during their first hospitalizations, and 15 patients had a total of 20 obstructions during follow-up. Survival was similar in both groups. CONCLUSIONS: The LeVeen shunt and paracentesis are equally effective in relieving refractory ascites. The former may provide better long-term control of ascites, but shunt occlusion is common and survival is not improved.

Albumins↗
PubMed1991

Oxygen diffusion near the heme binding site of horseradish peroxidase.

The quenching by molecular oxygen of the fluorescence of several probes complexed to apohorseradish peroxidase has been studied by intensity and time-resolved fluorescence methods. The probes utilized include 1-anilino-8-naphthalene sulfonic acid, 4,4'-bis (1-anilino-8-naphthalene sulfonic acid), and 2-p-toluidinylnaphthalene-6-sulfonic acid. These results are contrasted to those obtained using apohorseradish peroxidase complexed with protoporphyrin IX. The resistance of these complexes to denaturation by guanidine hydrochloride was determined. The results demonstrate a dramatic increase in oxygen accessibility to the naphthalene probes compared to protoporphyrin IX, which can be correlated to the increased stability of the protein-protoporphyrin IX complex.

Apoenzymes↗
PubMed1991

[Resection of hepatocarcinomas in liver cirrhosis: the value of intraoperative echography].

In the last 3 years 21 cirrhotic patients with hepatocellular carcinoma were operated. All patients fulfilled the criteria of localized tumor and good liver function and underwent a laparotomy with the aim of resecting the tumor. Intraoperative ultrasound examination was essential to localize a non visible and non palpable tumor in 2 cases and it was useful to detect other nodules in 3 of the 16 patients who underwent a hepatic resection of the tumor. In 5 patients resection was considered not indicated. Therefore, the initial therapeutic approach of tumoral resection was changed in 23.8% of patients. Also, intraoperative ultrasonography was essential for performing a guided resection of hepatocellular carcinomas in cirrhotic liver with the aim of preserving as much liver parenchyma as possible.

Aged↗
PubMed1991

[Long term follow-up of non-symptomatic HBsAg carriers].

232 asymptomatic HBsAg carriers were controlled between May/1986 and May/1990. The were detected in our blood bank between 1974 and 1976 or during pregnancy or delivery period after 1981. 23 of 232 (10%) became negative during the follow-up, this happening more frequently in carriers after 5 years of follow-up. Only 2 of 209 carriers with HBsAg were HBeAg positive and 1 of these was also DNA-VHB positive. None of the HBeAg negative carriers showed DNA-VHB; only 5 had increased transaminases. 7 were anti-VHC positive, these individuals experiencing more frequent increases in transaminases. The results of this study suggests that the determination of transaminases, viral activity markers, anti-HD, anti-VHC in HBsAg carriers are enough to identify those with hepatic disease.

Adolescent↗
PubMed1990

Norfloxacin prevents spontaneous bacterial peritonitis recurrence in cirrhosis: results of a double-blind, placebo-controlled trial.

Eighty cirrhotic patients who had recovered from an episode of spontaneous bacterial peritonitis were included in a multicenter, double-blind trial aimed at comparing long-term norfloxacin administration (400 mg/day; 40 patients) vs. placebo (40 patients) in the prevention of spontaneous bacterial peritonitis recurrence. At entry, both groups were similar with respect to clinical and laboratory data, ascitic fluid protein and polymorphonuclear concentrations, number of previous episodes of spontaneous bacterial peritonitis and causative organisms of the index spontaneous bacterial peritonitis. Norfloxacin administration produced a selective intestinal decontamination (elimination of aerobic gram-negative bacilli from the fecal flora without significant changes in other microorganisms) throughout the study in six patients in whom the effect of norfloxacin on the fecal flora was periodically assessed. Fourteen patients from the placebo group (35%) and five from the norfloxacin group (12%) developed spontaneous bacterial peritonitis recurrence during follow-up (chi 2 = 5.97; p = 0.014) (mean follow-up period = 6.4 +/- 0.6 mo; range = 1 to 19 mo). Ten of the 14 spontaneous bacterial peritonitis recurrences in the placebo group and only one of the five spontaneous bacterial peritonitis recurrences in the norfloxacin group were caused by aerobic gram-negative bacilli (chi 2 = 8.87; p = 0.0029). The overall probability of spontaneous bacterial peritonitis recurrence at 1 yr of follow-up was 20% in the norfloxacin group and 68% in the placebo group (p = 0.0063) and the probability of spontaneous bacterial peritonitis recurrence caused by aerobic gram-negative bacilli at 1 yr of follow-up was 3% and 60%, respectively (p = 0.0013).(ABSTRACT TRUNCATED AT 250 WORDS)

Bacterial Infections↗
PubMed1990

Dextran-70 versus albumin as plasma expanders in cirrhotic patients with tense ascites treated with total paracentesis. Results of a randomized study.

To investigate whether albumin can be substituted by less expensive plasma expanders in cirrhotic patients with tense ascites treated with total paracentesis, 88 patients (16 with renal failure) submitted to this therapeutic procedure were randomly assigned to receive IV albumin (43 patients) or dextran-70. Both substances were given at a dose of 8 g/L of ascitic fluid removed. Patients were discharged from the hospital with diuretics, and cases developing tense ascites during follow-up were treated according to their initial schedule. Total paracentesis was effective in eliminating the ascites in all but two cases in each group. Neither paracentesis plus IV albumin infusion nor paracentesis plus IV dextran-70 infusion was associated with significant changes in renal and hepatic function or serum electrolytes. The incidence of renal impairment (one case in each group), hyponatremia (three and four cases, respectively), and other complications (hepatic encephalopathy, gastrointestinal hemorrhage, bacterial infections) after paracentesis, and the clinical course of the disease as estimated by the probability of readmission to hospital during follow-up, causes of readmission, probability of survival, and causes of death were similar in the two groups of patients. The effect of paracentesis on effective intravascular volume was indirectly assessed by measuring plasma renin activity and aldosterone concentration before and 2 and 6 days after treatment, the patients being without diuretics. In patients treated with albumin, no significant changes in renin and aldosterone were observed during the entire period of observation. In contrast, both parameters increased significantly on the 6th day of treatment in patients receiving dextran-70. A significant increase in plasma renin activity and aldosterone concentration (30% over baseline values) was observed in 51% of patients treated with dextran-70 and in only 15% of those treated with albumin (x2 = 10.4; P = 0.0012). These results indicate that although dextran-70 is less efficacious than albumin in protecting cirrhotic patients treated with total paracentesis from the decrease in effective intravascular volume, it appears to be capable of preventing the renal and electrolyte complications induced by this therapeutic procedure.

Adult↗
PubMed1990

[The admission and discharge criteria of a unit for critical patients].

Admission and discharge criteria for patients in an intensive care unit are controversial, especially in view of the fact that some patients derive no benefit from intensive care therapy while depriving others from a potential benefit. The general characteristics of patients in need of intensive care are discussed. Irreversibility of the underlying condition, the quality of "terminal patient" and other factors that may contraindicate admission to an intensive care unit are analyzed. Discharge criteria for patients not expected to derive further benefit from a prolonged stay in the unit are outlined.

Humans↗
PubMed1989

Hepatitis C virus antibodies among risk groups in Spain.

The frequency of hepatitis C virus (HCV) infection in Spain was assessed by means of a recombinant-based immunoassay for serum anti-HCV antibodies. 836 serum samples were tested from 676 patients selected according to their risk of blood-borne viral infections and presence of liver disease. Among patients at high risk of infection (with or without liver disease) anti-HCV antibodies were found in 85% of prospectively followed patients with post-transfusion non-A, non-B hepatitis, 62% of patients with chronic hepatitis or cirrhosis and a history of blood transfusion, 70% of haemophiliacs receiving replacement therapy, 70% of intravenous drug abusers, and 20% of haemodialysis patients. Only 8% of homosexual men infected with human immunodeficiency virus and 6% of female contacts of drug abusers were positive. Among patients with liver disease and no history of parenteral exposure to blood, anti-HCV antibodies were detected in 38% with cryptogenic, alcoholic, or primary biliary cirrhosis and in 44% with chronic active hepatitis. Among healthy subjects without risk factors for hepatitis the overall prevalence of anti-HCV was 1.2%.

Adolescent↗
PubMed1988

The relationship between the structures of four beta-lactamases obtained from Bacillus cereus.

Bacillus cereus has proved to be one of the most interesting microorganisms in the study of beta-lactamases. It secrets these enzymes very efficiently and, frequently, in multiple forms. Three different forms are produced by strain 569/H; mutant 5/B of the same microorganism is constitutive for the secretion of beta-lactamases I and II. The present study, based on secondary structure prediction by two independent methods, states the relationship among the structures of beta-lactamases I, II and III produced by B. cereus 569/H and beta-lactamase I from the strain 5/B of this microorganism. A strong similarity is also established for the enzyme type III of B. cereus and the enzyme type I produced by B. licheniformis which could have an evolutionary explanation. A structural analysis of the leader peptide regions of these enzymes by the method of Mohana and Argos is also reported.

Bacillus cereus↗