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Biomedical subjects

J Vidal

Publications and source records attributed to J Vidal.

At least 109 records · Page 6Linked to original sources
PubMed1996

Differences of nu/+ and nu/nu mice in some behaviors reflecting temperament traits.

The goal of this paper is to discover a pattern of consistent behavioral differences between athymic CD1 nu/nu mice and euthymic CD1 nu/+ ones. The following behaviors, thought to be correlates of temperament traits, were measured along 3 trials: ambulation, rear, and defecation in two open fields of varying light intensity, interaction time with a conspecific, and variables in the light-darkness test (time in the lit compartment, latency to leave the dark compartment, and number of crossings between compartments). Besides, weight and (IgM and IgG) antibodies to rat erythrocytes were measured. Relative to nu/nu mice, nu/+ mice were heavier, yielded much higher antibody responses, interacted more with a conspecific (the males, but not the females), and ambulated slightly more in the open fields, although the proportion of variance in the behaviors accounted for by the nude mutation was small (< 20%). Therefore, the nude mutation participated in the expression of the activity or extraversion traits.

Animals↗
PubMed1996

FAD-glycerophosphate dehydrogenase activity in lymphocytes of type-2 diabetic patients and their relatives.

The activities of FAD-linked glycerophosphate dehydrogenase (m-GDH), glutamate dehydrogenase (GlDH), glutamate-pyruvate transaminase (GPT) and glutamate-oxalacetate transaminase (GOT) were measured in purified populations of CD3+ lymphocytes from 55 control subjects, 62 type-2 diabetics and 50 non-diabetic relatives of the latter patients. The activity of m-GDH was measured by both a radioisotopic procedure and colourimetric technique. As judged from these measurements and relative to the paired value for GlDH, the incidence of abnormally low m-GDH activity was significantly higher in type-2 diabetics than in control subjects. Moreover, the paired ratio in reaction velocity between the colourimetric and radioisotopic assay of m-GDH was abnormally high in patients with low m-GDH activity. Low m-GDH activity often coincided with increased GPT activity in plasma or high GPT/GOT ratio in lymphocytes. No obvious clustering of these anomalies was found in relatives of diabetic patients. These findings suggest that an inherited or acquired genomic defect of m-GDH in lymphocytes, and possibly in pancreatic B-cells, may participate to the pathogenesis of non-insulin-dependent diabetes mellitus.

Adult↗
PubMed1996

Effects of insulin administration on beta-cell function in subjects at high risk for type I diabetes mellitus.

The aim of the study was to determine the appropriate dose of subcutaneous insulin to induce "beta-cell rest" without any hypoglycemic risk, as the first stop in the investigation of its potential effect in preventing or delaying clinical diabetes mellitus onset in high-risk subjects. Four subjects at high risk for type I diabetes mellitus (first-degree relatives, islet cell antibodies (ICA)-positive, and with diminished first-phase insulin secretion) were compared with four healthy individuals. After hospitalization, urinary C-peptide excretion (UCP) and 24-hour serum profiles for glucose were measured before and after administration of NPH insulin 0.1, 0.2, and 0.3 U x kg body weight per day subcutaneously in a single dose on 4 consecutive days. After insulin 0.1 U x kg body weight, a significant inhibition of endogenous insulin secretion was observed in high-risk subjects, but not in control subjects. There was no further inhibition when a higher insulin dose (0.2 and 0.3) was administered. A sustained beta-cell rest was obtained after 3, 6, and 12 months of treatment with 0.1 U x kg body weight per day as outpatient therapy in high-risk subjects. With this dose, no subject developed hypoglycemia (plasma glucose <50 mg/dL), whereas this adverse effect was detected after 0.2 and 0.3 U x kg body weight in both groups. In conclusion, our results indicate that administration of NPH insulin 0.1 U x kg bodyweight per day induces beta-cell rest without the undesirable effect of hypoglycemic episodes. This is a preliminary study to investigate the potential beneficial effect of insulin in preventing or delaying type I diabetes mellitus in subjects at high risk for the disease.

Adolescent↗
PubMed1996

Immunogenicity and reactogenicity of a combined hepatitis A and B vaccine in young adults.

The aim of this study was to assess the immunogenicity and reactogenicity of a combined vaccine against hepatitis A virus (HAV) and hepatitis B virus (HBV) in young healthy adults. A total of 150 subjects (20 +/- 1.4 years; 111 females and 39 males) negative for anti-HAV, anti-HBs, anti-HBc and HBsAg markers, were enrolled and randomized to received the study vaccine from one of the three lots under double blind conditions. Three doses of the combined vaccine were administered by intramuscular route (deltoid) following a 0-, 1- and 6 months schedule. Each dose of 1 ml contained at least 720 ELISA Units of HAV antigen (Strain HM175) and 20 micrograms of recombinant HBsAg. Blood samples for anti-HAV (ELISA), anti-HBs (RIA) and transaminases determinations were obtained 1 month after the administration of each dose and before to the administration of the third dose (month 6). Local and general reactions were recorded by the vaccinee on the day of each vaccination and for the three following days on symptom sheets. A total of 147 subjects completed the study. There were not statistically significant differences between groups regarding to immunogenicity. All subjects had seroconverted [geometric mean titres (GMT): 1311 mIU ml-1] for hepatitis A component following the second dose; GMT increased to 8895 mIU ml-1 after the third dose. Seroconversion rates for hepatitis B component were 98% (GMT, 104 mIU ml-1) after the second dose and 100% after the third dose (GMT, 7097 mIU ml-1). There were not statistically significant differences between groups regarding to incidence of local and general symptoms. Soreness at the injection site and headache were the most commonly local and general symptoms reported, following 42% and 11% of the doses, respectively. This vaccine when given to young adults was well tolerated and induced high immunogenic response, similar to that obtained by hepatitis A and hepatitis B vaccines administered separately in previously reported trials.

Adult↗
PubMed1996

[Lichen planus associated with liver disease caused by hepatitis C virus].

The association between lichen planus (LP) and liver disease by the hepatitis C virus (HCV) has recently been described although its significance is controversial. The charts of 10 patients (8 women, 2 men) clinically and/or histologically diagnosed of LP and with positive HCV serology were retrospectively reviewed. Nine of the patients presented mucosal involvement, four of which were of the erosive form. In 7 patients liver disease preceded the appearance of LP. In the remaining 3 patients HCV infection was detected after the diagnosis of LP despite no alterations being observed in the liver function tests in 2 cases. Alpha-interferon 2b treatment triggered the lesions in 3 cases while leading to resolution of LP in another case. These data confirm the findings referred in the references and support the direct or indirect participation of HCV in LP.

Aged↗
PubMed1995

[The efficacy of the prevaccination detection of anti-HAV in hepatitis A vaccination programs].

BACKGROUND: The convenience of carrying out prevaccination detection studies of hepatitis A virus (HAV) markers depends on the relative costs of the detection and vaccination, as well as the prevalence of susceptible subjects in each population group to be vaccinated. The aim of this study was to analyze the efficacy of the systematic prevaccination detection of anti-HAV antibodies in Catalonia, Spain. METHODS: The following formula was applied: Unit cost of detection + (1-X) x Unit cost of vaccination of anti-HAV negative subjects = group vaccination cost, with X being the threshold of prevalence of marker under which detection no longer remains efficient. This prevalence was compared with the findings of a seroepidemiologic survey carried out in international travellers and food handlers. RESULTS: The unit cost of the detection of anti-HAV was calculated as 2,733 pesetas, and the unit cost of the vaccination as 9,963 pesetas obtaining a prevalence anti-HAV threshold of 27%. This prevalence corresponds to travellers under the age of 30 years and food handlers under the age of 25 years. CONCLUSIONS: The systematic detection of anti-HAV is only recommended in population groups in which prevalences higher than 27% may be expected. The vaccination is more efficient without a previous marker study under this threshold. According to this study, direct vaccination of food handlers under the age of 25 years (born after 1969) is recommended as is that of international travellers under the age of 30 years (born after 1964). In those over the age of these collectives, the prevaccination study is more efficient.

Adolescent↗
PubMed1995

[Insulin treatment in diabetes mellitus type II: the usefulness of the breakfast test].

BACKGROUND: Insulin treatment in patients with type-II diabetes mellitus (DMII) is normally undertaken by clinical criteria. The aim of the present was to study the efficacy of a standard mixed meal (breakfast test) to predict the need for insulin therapy to thereby evaluate whether it is possible to obtain more objective criteria for the indication of insulin treatment. METHODS: Fifty-six patients with DMII were studied to evaluate the need for insulin therapy over a one-year period. Serum glucose and basal C peptide and their maximum values were determined in all the patients following stimulation with the breakfast test. Insulin treatment was initiated according to exclusively clinical criteria during admission. The patients were followed as out patients for a minimum of 3 months. Treatment at the end of follow up (insulin or no insulin) was evaluated and the results of the test were retrospectively analyzed. RESULTS: The basal C peptide (BCP) values were significantly lower in the individuals requiring insulin in comparison to those who did not require insulin (mean +/- SD 0.64 +/- 0.28 versus 1.18 +/- 0.41 nmol/l, p < 0.0001) similar to what was found with the stimulated maximum C peptide values (MCP) (1.48 +/- 0.77 versus 2.49 +/- 0.63 nmol/l, p < 0.0001). On considering a BCP of less than 0.9 nmol/l for the patients with insulin treatment the sensitivity of BCP was 83.6% and the specificity 78.9%. For a BCP value of less than 1.9 nmol/l sensitivity was 77.7% and specificity 78.9%. Using the values together, sensitivity was 66.6% and specificity 84.4%. CONCLUSIONS: The breakfast test is useful to indicate the need for insulin therapy in patients with type II diabetes mellitus but is not more useful than a determination of isolated basal C peptide.

Adult↗
PubMed1995

Hormone-dependent transactivation by the human androgen receptor is regulated by a dnaJ protein.

Genetic studies were performed to examine the role of eukaryotic dnaJ protein, Ydj1p, in the regulated activation of human androgen receptor (hAR) after heterologous expression in Saccharomyces cerevisiae. Hormone-dependent activation of hAR was measured as a function of lacZ reporter gene expression, which was defective in ydj1-151 and ydj1-2 delta null mutant strains compared to the wild type. This defect was not due to receptor misfolding, since hAR in both wild type and mutant strains had a similar capacity to bind hormone. The target for Ydj1p action was determined to be the hAR hormone binding domain since an N-terminal fragment lacking this region was constitutively active in both wild type and ydj1-151 mutant strains. These data correlate hormone dependence of hAR activation with a requirement for Ydj1p function and are consistent with a role for dnaJ proteins in signal transduction by steroid hormone receptors.

Bacterial Proteins↗
PubMed1995

Kinetic analysis of the non-phosphorylated, in vitro phosphorylated, and phosphorylation-site-mutant (Asp8) forms of intact recombinant C4 phosphoenolpyruvate carboxylase from sorghum.

Steady-state kinetic analyses were performed on the non-phosphorylated, in vitro phosphorylated and phosphorylation-site mutant (Ser8-->Asp) forms of purified recombinant sorghum C4 phosphoenolpyruvate (P-pyruvate) carboxylase (EC 4.1.1.31) containing an intact N-terminus. Significant differences in certain kinetic parameters were observed between these three enzyme forms when activity was assayed at a suboptimal but near-physiological pH (7.3), but not at optimal pH (8.0). Most notably, at pH 7.3 the apparent Ki for the negative allosteric effector L-malate was 0.17 mM, 1.2 mM and 0.45 mM while the apparent Ka for the positive allosteric effector glucose 6-phosphate (Glc6P) at 1 mM P-pyruvate was 1.3 mM, 0.28 mM and 0.45 mM for the dephosphorylated, phosphorylated and mutant forms of the enzyme, respectively. These and related kinetic analyses at pH 7.3 show that phosphorylation of C4 P-pyruvate carboxylase near its N-terminus has a relatively minor effect on V and Km (total P-pyruvate) but has a dramatic effect on the extent of activation by Glc6P, type of inhibition by L-malate and, most especially, Ka (Glc6P) and Ki (L-malate). Thus, regulatory phosphorylation profoundly influences the interactive allosteric properties of this cytosolic C4-photosynthesis enzyme.

Edible Grain↗
PubMed1995

[Arthropathy associated with infection by parvovirus B19. Description of 4 cases].

Four cases of human parvovirus infection in which the main clinical manifestation was a polyarthritis are described. Four females with ages ranging from 30 to 32 years presented with acute symmetrical polyarthralgias involving hands and knees. In addition, evidence of synovitis in the ankles and tenosynovitis of the fingers was found in two and three cases respectively. Half of the patients noticed an erythematous rash in the preceding days. Laboratory studies were normal in all cases. Antinuclear antibodies and rheumatoid factor were not detected in any case. All patients had significant levels of IgG and IgM antibodies to parvovirus B19 at the time of presentation and a rise in IgG and a fall in IgM levels were seen at two months. All cases cleared up within two weeks without treatment.

Adult↗
PubMed1995

Large-scale study suggests no direct link between human herpesvirus-6 and primary Sjögren's syndrome.

The aim of this study was to evaluate the role of human herpesvirus-6 (HHV-6) in the development of primary Sjögren's syndrome (PSS). Serum HHV-6 antibody levels, as measured by immunofluorescence assay (IFA) and the prevalence of HHV-6 DNA in peripheral blood mononuclear cells (PBMCs) determined by polymerase chain reaction (PCR), were studied in 49 PSS patients and 50 control subjects, all in-patients in the University Hospital Internal Medicine ward, Limoges, France. In addition, portions of labial salivary gland were obtained from 34 patients and 15 controls, the presence of viral DNA being detected by the same PCR technique. The results were then compared with clinical observations of systemic disease manifestations in patients and a histological study of salivary gland involvement. No significant difference in HHV-6 seroprevalence was found between control subjects (50.0%) and patients (63.3%) nor was there any statistically significant difference between patient and control groups for total viral DNA in PBMCs (22.4%, 12.0%) and salivary glands (8.8%, 6.6%). Analysis of clinical and histological data revealed no detectable correlation between disease severity and viral involvement. Tests for HHV-6A and HHV-6B proved positive in patient and control groups, HHV-6B being the most frequently encountered type in both groups. In conclusion, the results of this large-scale trial does not confirm the suspected direct role of HHV-6 in the etiology of PSS.

Antibodies, Viral↗
PubMed1995

Prevalence and clinical significance of anticardiolipin antibodies in pregnancies complicated by parvovirus B19 infection.

Anticardiolipin antibodies were measured in 60 pregnant women with acute parvovirus B19 infection. Test results for eight (13.3 per cent) women were positive for anticardiolipin antibody. Six of these eight women became negative later, yielding a prevalence of anticardiolipin antibodies of 3.3 per cent (2/60) 6 months after acute parvovirus B19 infection. Anticardiolipin antibody positivity was not associated with an increased risk of abortion, fetal death, or maternal complications. This study suggests that there is an elevated frequency of anticardiolipin antibodies in pregnant women with acute parvovirus B19, probably representing an epiphenomenon. However, this is not associated with an adverse maternal or perinatal outcome.

Antibodies, Anticardiolipin↗
PubMed1995

Effects of an individual intensive educational control program for insulin-dependent diabetic subjects with poor metabolic control.

The aim of our study was to evaluate the efficiency of an individual intensive educational control program on improving the metabolic control of insulin-dependent diabetic patients at short- and long-term follow-up. Fifteen insulin-dependent diabetic subjects with poor metabolic control (hemoglobin A1c > 9%) were included. At entry, their knowledge of diabetes (DKQ2 test), total energy intake and its distribution, insulin schedule, technical skill for insulin administration and self monitoring of blood glucose were evaluated. According to the initial evaluation, individual goals were stipulated and monitored in weekly visits. Individual life-style was particularly kept in mind. Thereafter, patients were switched to our ambulatory clinic for outpatients. At 1, 6, 12 and 24 months of follow-up, the items analyzed at the beginning were reevaluated. After 1 month, the program produced a significant decrease in hemoglobin A1c and an increase in knowledge of diabetes. The same beneficial effects were present at 6, 12 and 24 months evaluation compared to those values recorded at entry. There were neither major changes in dietary intake nor insulin schedule nor any increase in the frequency of hypoglycemic episodes. In conclusion, our program (5.2 +/- 0.8 weekly visits) significantly reduced and sustained hemoglobin A1c values close to those levels recommended by multicenter controlled trials. We consider that our program produced two major changes: a long-lasting improvement in knowledge of diabetes and an increase in self-monitoring blood glucose which provided the key for optimal self-regulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Microwave treatment of serum facilitates detection of hepatitis B virus DNA by the polymerase chain reaction. Results of a study in anti-HBe positive chronic hepatitis B.

Investigation by polymerase chain reaction of HBV-DNA in serum from chronic hepatitis B virus carriers is not widely used for routine diagnosis because polymerase chain reaction assays are complex and may be too sensitive. We investigated the sensitivity, the specificity and the possible value for clinical use of a simplified polymerase chain reaction method in which a single, 30 cycles round of polymerase chain reaction is performed using only 10 microliters of serum treated with microwaves. The efficiency of the polymerase chain reaction in amplifying HBV-DNA was greater after microwave irradiation of serum than after alkaline extraction, but lower than after protein digestion and phenol chloroform precipitation. Despite its simplicity and high sensitivity, the assay was very specific. Studies in anti-HBe positive chronic hepatitis B virus carriers demonstrated HBV-DNA sequences in 1/15 (7%) healthy carriers, in 4/20 (20%) patients with slight alanine aminotransferase elevation, in 16/18 (89%) with marked alanine aminotransferase elevation and in all 20 with fluctuating alanine aminotransferase levels. In the latter, HBV-DNA was detected either at exacerbation (two cases), during remission (one case) or both (17 cases). HBV-DNA was detected by classical dot-blot hybridization in only 24/58 (41%) samples that were positive by the simplified polymerase chain reaction method. Although extremely high sensitivity is not achieved, microwave irradiation of serum simplifies considerably the detection of small amounts of HBV-DNA and makes polymerase chain reaction suitable for monitoring patients in whom weak hepatitis B virus replication is associated with ongoing liver disease.

Adult↗
PubMed1995

The incidence of human parvovirus B19 infection during pregnancy and its impact on perinatal outcome.

A prospective study of parvovirus B19 infection during pregnancy was conducted at a large teaching hospital in Barcelona, Spain. Women (1610) who were < 28 weeks pregnant at enrollment were screened for parvovirus infection. The prevalence of IgG positivity was 35.03% (564/1610). The incidence of acute infection during pregnancy was 3.7% (60/1610). There were five abortions among the B19-infected women but only one was caused by parvovirus, as assessed by histologic examination and polymerase chain reaction assay. The incidence of fetal loss caused by parvovirus was, therefore, 1.66% (1/60). The remaining 55 pregnancies were uneventful, and at 1 year of age, none of the infants had serious abnormalities. The incidence of vertical transmission of infection was estimated at 25%. This study provides evidence that although acute parvovirus infection may occur relatively commonly during pregnancy, an adverse fetal outcome is a rare complication.

Adult↗