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Biomedical subjects

D Vaira

Publications and source records attributed to D Vaira.

At least 127 records · Page 7Linked to original sources
PubMed1991

A 10 year single centre experience of percutaneous and endoscopic extraction of bile duct stones with T tube in situ.

A non-randomised single centre study of 226 consecutive patients referred over 10 years with retained common bile duct stones and a T tube in situ or a cholecystostomy tube are reported. Percutaneous extraction was attempted in 204 and endoscopic extraction in 68 patients. Percutaneous clearance was achieved in 158 (77.5%) patients and endoscopic clearance in 52 (76.5%) patients. Six of 153 (3.9%) patients followed after percutaneous treatment suffered major complications (pancreatitis, cholangitis, or tract perforation). Three of 67 (44%) patients followed after endoscopic treatment suffered major complications (pancreatitis, cholangitis, or bleeding). When the initial method of treatment failed, the alternative was used, resulting in an overall success rate of bile duct clearance of 94.3%. It is concluded that percutaneous and endoscopic methods of bile duct clearance in patients with a T tube in situ are equally effective, carrying similar complication rates. This study has helped to clarify the indications and efficacy of these alternative treatments.

Adult↗
PubMed1990

Mouse mammary tumor virus (MMTV) infection in SWISS and RIII mice. Correlation between resistance to exogenous infection and anti-MMTV serum response.

Host-virus relationships were examined in mice from the two mouse mammary tumor virus (MMTV)-infected strains SWISS MB+ and RIII, which harbour the same MMTV variant, and from the derived sublines Swiss MB- and RIIIf, which were freed of milk-borne MMTV by foster-nursing. These two strains are not phylogenetically related, the SWISS strain bearing the endogenous Mtv-3 locus in its DNA. In RIII and SWISS MB+ mice, the incidence of early mammary tumors, which was of 96% and 8%, respectively, was correlated to the level of MMTV expression in milk. In the SWISS MB-line, a non-coordinate expression of the provirus associated with the Mtv-3 locus was observed in the mammary glands, the salivary glands and the spleen. This expression was not tumorigenic and was characterized by the presence of the p28 gag antigen and the absence of the gp52 env antigen, except, however, in mammary glands of elder mice where traces of gp52 were found. In the mammary glands of SWISS MB+ mice, the expression of the Mtv-3 locus was masked by large amounts of antigens resulting from exogenous virus expression. RIIIf mice were MMTV-negative. Viral antigens coexisted with anti-MMTV antibodies in the serum of infected and tumor-bearing mice, but not in the form of immune complexes as verified by a method that allowed to detect specific antigen-containing-soluble immune complexes. An anti-MMTV serum reactivity was also detected in SWISS MB- and RIIIf mice. However, the serum response was higher in the two SWISS lines than in the two RIII lines. Except in tumor-bearing mice, the anti-MMTV response was not significantly modified by the presence of exogenous virus and thus resulted essentially from exposure to endogenous MMTV expression. In experimental infection studies, RIII mice were more susceptible to MMTV infection than SWISS mice. The correlation between resistance to MMTV infection and serum response to endogenous MMTV expression, suggests that the non-tumorigenic expression of an endogenous provirus can protect at least partially, against exogenous MMTV infection.

Animals↗
PubMed1990

The diagnosis of small bowel bacterial overgrowth. Reliability of jejunal culture and inadequacy of breath hydrogen testing.

The reliability of a single jejunal culture in the diagnosis of small bowel bacterial overgrowth has recently been questioned. Seventy-seven patients thought to have bacterial overgrowth, defined as a jejunal culture yielding at least 10(6) organisms per milliliter of aspirate, took part in the study. Bacterial overgrowth was found in 74% of the patients with predisposing conditions and in 32% of those with no clear causes of bacterial colonization. The intestinal juice of some patients was taken at two different levels of the proximal jejunum, using both the closed- and open-tube systems. Highly significant correlations (rs = 0.90, p less than 0.001) were found between the numbers of bacteria per milliliter at the 2 jejunal levels and between the numbers of bacteria per milliliter of jejunal aspirate obtained from the closed and open tubes (rs = 0.84, p less than 0.001). Compared with the jejunal culture, the gas chromatography of volatile fatty acids in jejunal aspirate and the glucose- and lactulose-hydrogen breath tests showed sensitivities of 56%, 62%, and 68% and specificities of 100%, 83%, and 44%, respectively. This work demonstrates the reliability of jejunal cultures and the inadequacy of breath hydrogen testing in the prediction of positive jejunal cultures. When results of testing for volatile fatty acids in jejunal aspirates are positive, this always indicates the presence of bacterial overgrowth; thus, this procedure would avoid the more complicated, time-consuming, and costly bacteriological analysis of jejunal samples.

Bacterial Infections↗
PubMed1990

Activation of human immunodeficiency virus type 1 by oxidative stress.

An important aspect of the infection by the human immunodeficiency virus (HIV-1) type 1 is its clinical latency, suggesting that the virus itself or the provirus may remain latent for extended periods of time after primary infection. Certain heterologous viral proteins or chemical and physical agents are able to reactivate latent virus. Since a common denominator shared by these agents is the ability to cause stress response in cells, we have examined the effects of oxidative stress mediated by hydrogen peroxide (H2O2) on HIV-1 latently infected promonocytic cell line termed U1. After exposure to H2O2 in concentrations ranging from 0.1 to 2 mM, the viability of the U1 cells decreased during 24 h before recovery. At 24 h post stress, the U1 cells began to express virus as assessed by elevated reverse transcriptase activities in culture supernatants. Immunofluorescence carried out on stressed U1 cells using anti-HIV-1 polyclonal antibodies showed that H2O2 leads to HIV-1 gene expression activation, but not to a release of viral particles from damaged cells. Additionally, using a HeLa cell line containing integrated the bacterial chloramphenicol acetyl transferase (CAT) gene under the control of the HIV-1 long terminal repeat (LTR), we have shown that oxidative stress mediated by H2O2 allows transactivation of the viral LTR revealed by intracellular CAT activity. A stimulation factor of around 4 of CAT activity can be reached when these cells are treated with 0.5 mM H2O2.(ABSTRACT TRUNCATED AT 250 WORDS)

Cell Division↗
PubMed1990

Needle knife papillotomy: how safe and how effective?

Between January 1986 and July 1988 needle knife papillotomy was attempted in 103 patients after failure of conventional access for endoscopic sphincterotomy (96 cases) or diagnostic cholangiography (seven cases). Access was obtained at the same session in 36 cases and at a subsequent attempt within 2 to 5 days in a further 43, an overall success rate of 77%. The procedure related morbidity and mortality in the therapeutic group were 5.2% and 2.0% respectively. There were no deaths or complications in the diagnostic group. Needle knife papillotomy is a valuable adjunct to conventional techniques of biliary access.

Aged↗
PubMed1990

Serum pepsinogen I and gastrin concentrations in children positive for Helicobacter pylori.

Serum pepsinogen I, serum gastrin concentration, and inflammatory scores were measured in a population of 71 children undergoing upper gastrointestinal endoscopy for investigation of upper abdominal pain. Forty four were initially colonised with Helicobacter pylori. The indices were measured before treatment (in 71 children), one month (in 41 children), and six months (in 21 children) after stopping treatment. Before treatment there was a significant correlation between serum pepsinogen concentration, total inflammatory score, and H pylori state, but no correlation between serum gastrin concentrations and H pylori state. Similarly, the total inflammatory score and serum pepsinogen concentrations were significantly correlated. There was no such correlation in children negative for H pylori. After treatment the inflammatory score improved in those patients in whom H pylori had been eradicated. There was also a significant fall in serum pepsinogen I and serum gastrin concentration in those patients in whom H pylori had been eradicated. These results were similar to those found six months after treatment had been stopped. These findings suggest that the serum pepsinogen I concentration could be considered a useful marker for gastritis and can be used as an index of severity of gastritis in H pylori positive subjects. The measurement of serum gastrin concentrations does not give useful information.

Adolescent↗
PubMed1990

Endoscopy in dyspeptic patients: is gastric mucosal biopsy useful?

Should dyspeptic patients coming to endoscopy with "normal" findings also be biopsied? To assess this, we studied the sensitivity and specificity of endoscopic examination compared with histology, microscopic evidence of Helicobacter pylori, CP-TEST, culture, and serum IgG and IgA antibody titers to H. pylori to determine whether endoscopy and antral biopsies really are useful. One hundred seven consecutive dyspeptic patients (mean age 43 yr) were entered. Four antral biopsies were taken routinely for evaluation by histology, microscopy, CP-TEST, and culture. Serum IgG and IgA antibody levels were measured in all patients. Of symptoms, postprandial bloating was statistically more common in H. pylori-positive than in negative patients. Endoscopy had the poorest sensitivity (37.1%) and specificity (53.3%). Patients with normal endoscopic appearances but histologically confirmed gastritis had significantly higher IgG and IgA titers than the patients normal by both endoscopy and histology and without evidence of H. pylori. This study has shown that endoscopy is unhelpful in dyspeptic patients if endoscopic biopsies are not routinely taken.

Adult↗
PubMed1989

Endoscopic sphincterotomy in 1000 consecutive patients.

Between 1983 and 1988, endoscopic sphincterotomy was attempted on 1000 consecutive patients with a clinical diagnosis of bileduct stones in a centre with a policy to establish immediate bileduct drainage for retained stones. Endoscopic cholangiography was successful in 985 patients, of whom 782 had visible stones and 203 had a dilated bileduct but no visible stones. Endoscopic sphincterotomy was successful in 975 of these patients, with eventual bileduct clearance in 674 of 772 patients (87.3%) with visible stones; immediate bileduct drainage was achieved in 160 of the 161 patients (99%) in whom bileduct clearance failed at the first attempt. Overall, 771 of 797 patients (96.7%) with visible bileduct stones had successful bileduct clearance or drainage. Complications occurred in 6.9%, with a 30-day mortality rate of 1.2%, but procedure-related mortality was only 0.6%.

Adult↗
PubMed1989

Amoxycillin plus tinidazole for Campylobacter pylori gastritis in children: assessment by serum IgG antibody, pepsinogen I, and gastrin levels.

32 children (mean age 12 years, range 6-18) with non-specific abdominal pain and Campylobacter pylori positive gastritis received a six week course of daily oral amoxycillin (50 mg/kg) and tinidazole (20 mg/kg). Before treatment and one month after stopping treatment, endoscopic biopsy samples were taken from the antral mucosa and serum C pylori IgG antibody, pepsinogen I, and gastrin levels were measured in fasting blood samples. One month after treatment 30 children (94%) were cleared of C pylori and gastritis had resolved in 27 (84%) and was improved in the remaining 5. Serum IgG, pepsinogen I, and gastrin levels were significantly decreased after treatment. Of 12 children assessed at six months, 9 remained free of C pylori. Increases or decreases in IgG level indicated clearance or recurrence, respectively, of C pylori.

Administration, Oral↗
PubMed1989

Endoscopic endoprosthesis insertion following failure of cholecystojejunostomy in pancreatic carcinoma.

Sixteen patients in whom malignant biliary obstruction recurred after failure of cholecystojejunostomy had attempted relief of obstruction by endoscopic insertion of an endoprosthesis. This treatment was successful in 13 patients, although one required percutaneous insertion because of duodenal distortion and one required a combined percutaneous-endoscopic approach. Median survival after stenting was 3.5 months (range from 2 weeks to 16 months). Of the three treatment failures, two patients had external drainage only and one succumbed before further treatment could be attempted. There were two complications associated with the procedure (one small bile leak and one episode of cholangitis) but the 30-day mortality rate of 12.5 per cent was related to disease progression rather than the procedure. Endoscopic stent insertion may achieve further worthwhile palliation of jaundice after the failure of surgery to relieve malignant biliary obstruction.

Adenocarcinoma↗