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Biomedical subjects

J Ruiz

Publications and source records attributed to J Ruiz.

At least 253 records · Page 14Linked to original sources
PubMed1994

Insertion/deletion polymorphism of the angiotensin-converting enzyme gene is strongly associated with coronary heart disease in non-insulin-dependent diabetes mellitus.

Non-insulin-dependent diabetes mellitus (NIDDM) is considered a model of premature atherosclerosis with a strong genetic component. We have investigated the role of angiotensin-converting enzyme (ACE; EC 3.4.15.1) gene in 316 unrelated NIDDM individuals, 132 who had myocardial infarction or significant coronary stenoses and 184 with no history of coronary heart disease (CHD). A deletion-polymorphism in the ACE gene was recently reported to be associated with myocardial infarction especially in people classified as low risk. Here we report that the D allele of the ACE gene is a strong and independent risk factor for CHD in NIDDM patients. The D allele is associated with early-onset CHD in NIDDM, independently of hypertension and lipid values. A progressively increasing relative risk in individuals heterozygous and homozygous for the D allele was observed (odds ratios of 1.41 and 2.35, respectively; P < 0.007), suggesting a codominant effect on the cardiovascular risk. The percentage of CHD attributable to the ACE deletion allele was 24% in this NIDDM population. Identification of NIDDM patients carrying this putative CHD-susceptibility genotype would help early detection and treatment of CHD.

Alleles↗
PubMed1994

High prevalence of HHV-6 DNA in peripheral blood mononuclear cells of healthy individuals detected by nested-PCR.

The aim of the study was the evaluation of human herpesvirus-6 (HHV-6) infection rate and semiquantification of viremia in healthy people. Healthy blood donors were studied. Human herpesvirus-6 IgG and IgM antibody titers were measured by indirect immunofluorescence assay. Human herpesvirus-6 DNA amplification (nested-PCR) was performed in peripheral blood mononuclear cells (PBMC) and in serum. Seventeen of 50 (34 percent) individuals were positive for IgG anti-HHV-6 and the titers ranged from 1:40 to 1:160. None of 30 individuals was positive for IgM anti-HHV-6, suggesting no recent infection nor reactivation. Human herpesvirus-6 DNA was detected by nested-PCR amplification in peripheral blood mononuclear cells but not in sera. When 1 microgram DNA was amplified, HHV-6 DNA was detected in 8 of 20 individual (40%), but in 18 of 20 (90%) when 5 micrograms DNA were amplified. It is concluded that HHV-6 is present in a high proportion of the healthy population but in minimal amounts, and although it can be detected in 1.4 x 10(5) PBMC, 7 x 10(5) cells are necessary to detect most cases. No reactivation was observed in healthy people.

Adult↗
PubMed1994

Association of elevated lipoprotein(a) levels and coronary heart disease in NIDDM patients. Relationship with apolipoprotein(a) phenotypes.

Non-insulin-dependent diabetes mellitus (NIDDM) is a strong and independent risk factor for coronary heart disease. We assessed the potential relationship between plasma Lp(a) levels, apo(a) phenotypes and coronary heart disease in a population of NIDDM patients. Seventy-one patients with coronary heart disease, who previously have had transmural myocardial infarction, or significant stenosis on coronary angiography, or positive myocardial thallium scintigraphy, or in combination, were compared with 67 patients without coronary heart disease, who tested negatively upon either coronary angiography, myocardial thallium scintigraphy or a maximal exercise test. The prevalence of plasma Lp(a) levels elevated above the threshold for increased cardiovascular risk (> 0.30 g/l) was significantly higher (p = 0.005) in patients with coronary heart disease (33.8%) compared to the control group (13.4%). The relative risk (odds ratio) of coronary heart disease among patients with high Lp(a) concentrations was 3.1 (95% confidence interval, 1.31-7.34; p = 0.01). The overall frequency distribution of apo(a) phenotypes differed significantly between the two groups (p = 0.043). However, the frequency of apo(a) isoforms of low apparent molecular mass (< or = 700 kDa) was of borderline significance (p = 0.067) between patients with or without coronary heart disease (29.6% and 16.4%, respectively). In this Caucasian population of NIDDM patients, elevated Lp(a) levels were associated with coronary heart disease, an association which was partially accounted for by the higher frequency of apo(a) isoforms of small size. In multivariate analyses, elevated levels of Lp(a) were independently associated with coronary heart disease (odds ratio 3.48, p = 0.0233).

Apolipoproteins A↗
PubMed1994

[Minimal intervention in smoking in the outpatient pneumonology consultation].

Brief intervention (BI) in smoking has been shown to be an effective way of stopping smoking in the general population. BI involves medical advice given to each smoking patient, with complementary information on the effects of smoking on the body and methods of giving up the habit. Patients who come to the clinic with respiratory disease may be especially receptive to BI since the strong link between their symptoms and smoking may increase their motivation for cessation. A BI protocol on smoking was applied in 285 smokers seen in an outpatient pneumological clinic. Two hundred eight smokers (group A) received medical advice and health care education with the offer of follow up. Seventy-seven smokers (group B) received the same BI protocol, with the offer of support treatment with nicotine gum (2 mg) and an explanation as to its use. One year after BI the patients were contacted by telephone to determine the number of non-smokers, with the result adjusted according to the truth index (71.4%) known for telephone response in this context. A total of 71 (24.9%) smokers were not located by telephone due to change of address, wrong number, exitus or lack of telephone. The estimated number of non-smokers in group A was 31.5/160 (19.7%) and 8.6/54 (15.9%) (non significant difference, chi square test). Group B's use of nicotine gum was therapeutically significant in 11.0% of the cases. We conclude that the efficacy of BI in the outpatient pneumological clinic is high.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Recurrent pulmonary embolism in patients treated because of acute venous thromboembolism: a prospective study.

OBJECTIVE: To evaluate the risk of pulmonary embolism (PE) despite adequate heparin therapy in a large series of patients with acute deep venous thrombosis and/or pulmonary embolism. DESIGN: Prospective study. SETTING: University Hospital Germans Trias i Pujol, Badalona, Spain. MATERIALS: 348 patients admitted because of deep venous thrombosis in the lower limbs and/or pulmonary embolism. A baseline lung scan was obtained initially in every patient, whether the original diagnosis was PE or deep vein thrombosis (DVT). Repeat chest X-ray and lung scans were obtained routinely at 8 days of heparin onset. OUTCOME MEASURES: The primary trial endpoint was a finding of confirmed, clinically apparent recurrent PE; in addition, laboratory evidence of subclinical PE at the repeat scan was also considered. RESULTS: PE recurrences were found in 23/348 patients (7%). No significant differences were found in age and sex distribution, or in the degree of DVT proximity between patients who developed and those who did not develop recurrences. Recurrent PE was more commonly found in patients with scintigraphic evidence of PE on admission, irrespectively of the original diagnosis being DVT or PE (18/151 vs. 3/155; p = 0.0005, Fisher's exact test). Recurrences were also more common in patients in whom thrombosis developed in the absence of any known risk factor (10/70 vs. 13/278; p = 0.007). The logistic regression analysis confirmed the statistical significance of these two clinical variables. CONCLUSIONS: Pulmonary embolism despite adequate heparin therapy is not an uncommon event. It appears possible to identify a subgroup of patients at a higher risk, and, modify treatment accordingly.

Adolescent↗
PubMed1994

Association between double mutation in gyrA gene of ciprofloxacin-resistant clinical isolates of Escherichia coli and MICs.

The mutations in the quinolone resistance-determining region of the gyrA and gyrB genes from 27 clinical isolates of Escherichia coli with a range of MICs of ciprofloxacin from 0.007 to 128 micrograms/ml and of nalidixic acid from 2 to > 2,000 micrograms/ml were determined by DNA sequencing. All 15 isolates with ciprofloxacin MICs of > or = 1 micrograms/ml showed a change in Ser-83 to Leu of GyrA protein, whereas in clinical isolates with a MIC of > or = 8 micrograms/ml (11 strains), a double change in Ser-83 and Asp-87 was found. All isolates with a MIC of nalidixic acid of > or = 128 micrograms/ml showed a mutation at amino acid codon Ser-83. Only 1 of the 27 clinical isolates of E. coli analyzed showed a change in Lys-447 of the B subunit of DNA gyrase. A change in Ser-83 is sufficient to generate a high level of resistance to nalidixic acid, whereas a second mutation at Asp-87 in the A subunit of DNA gyrase may play a complementary role in developing the strain's high levels of ciprofloxacin resistance.

Amino Acid Sequence↗
PubMed1994

Mechanisms of fatty acid-induced inhibition of glucose uptake.

Increased plasma FFA reduce insulin-stimulated glucose uptake. The mechanisms responsible for this inhibition, however, remain uncertain. It was the aim of this study to determine whether the FFA effect was dose dependent and to investigate its mechanism. We have examined in healthy volunteers (13 male/1 female) the effects of three steady state plasma FFA levels (approximately 50, approximately 550, approximately 750 microM) on rates of glucose uptake, glycolysis (both with 3-3H-glucose), glycogen synthesis (determined with two independent methods), carbohydrate (CHO) oxidation (by indirect calorimetry), hepatic glucose output, and nonoxidative glycolysis (glycolysis minus CHO oxidation) during euglycemic-hyperinsulinemic clamping. Increasing FFA concentration (from approximately 50 to approximately 750 microM) decreased glucose uptake in a dose-dependent fashion (from approximately 9 to approximately 4 mg/kg per min). The decrease was caused mainly (approximately 2/3) by a reduction in glycogen synthesis and to a lesser extent (approximately 1/3) by a reduction in CHO oxidation. We have identified two independent defects in glycogen synthesis. The first consisted of an impairment of muscle glycogen synthase activity. It required high FFA concentration (approximately 750 microM), was associated with an increase in glucose-6-phosphate, and developed after 4-6 h of fat infusion. The second defect, which preceded the glycogen synthase defect, was seen at medium (approximately 550 microM) FFA concentration, was associated with a decrease in muscle glucose-6-phosphate concentration, and was probably due to a reduction in glucose transport/phosphorylation. In addition, FFA and/or glycerol increased insulin-suppressed hepatic glucose output by approximately 50%. We concluded that fatty acids caused a dose-dependent inhibition of insulin-stimulated glucose uptake (by decreasing glycogen synthesis and CHO oxidation) and that FFA and/or glycerol increased insulin-suppressed hepatic glucose output and thus caused insulin resistance at the peripheral and the hepatic level.

Adult↗
PubMed1994

Insulin receptor down-regulation and impaired antilipolytic action of insulin in diabetic patients after pancreas/kidney transplantation.

Patients with insulin-dependent diabetes who receive pancreas/kidney transplants lose their need for insulin injections, but they become hyperinsulinemic and insulin resistant, and sometimes develop noninsulin-dependent diabetes mellitus. The reason for the insulin resistance is not well understood. Specifically, it is not known whether they become resistant to the action of insulin on lipid metabolism. Euglycemic-hyperinsulinemic clamps were performed in six pancreas/kidney (P/K) recipients, six kidney (K) recipients (to control for immunosuppressive therapy), and eight healthy controls. Measured were leg blood flow (by plethysmography), rates of lipolysis (with [2H5] glycerol), fatty acid oxidation (by indirect calorimetry), fatty acid reesterification (with [2H5]glycerol and [1-13C]palmitate), monocyte membrane insulin binding (with [125I]Tyr-A14 insulin), and insulin receptor mass (by RIA). Fasting plasma insulin concentrations were 2 times higher in P/K and K recipients (108 pmol/L) than in controls (54 pmol/L). Insulin receptor mass in solubilized monocyte membranes from P/K and K recipients was reduced by 61% and 63%, respectively, whereas insulin binding was reduced by 73% and 70%, respectively. P/K and K recipients were resistant to the inhibitory action of insulin on lipolysis (P/K vs. controls, P < 0.01; K vs. controls, P < 0.02) and on fatty acid reesterification (P/K vs. controls, P < 0.02; K vs. controls, P < 0.03). P/K recipients appeared to be more resistant than K recipients, but the differences between the two groups were not statistically significant. We conclude that P/K recipients were hyperinsulinemic, had down-regulated the number of their monocyte insulin receptors, and were resistant to the antilipolytic action of insulin.

Adult↗
PubMed1994

[Evaluation of the speed of 3 hemoculture systems to detect bacteria in the blood].

BACKGROUND: The speed of three culture blood systems to detect microbial growth was evaluated with 138 strains isolated from blood which belonged to nine species (N. meningitidis, S. aureus, S. pneumoniae, E. coli, E. faecalis, P. aeruginosa, H. influenzae, A. anitratus and Candida spp.). METHODS: An inoculum of 5-50 UFC were added to each bottle: vials 26 plus with Bactec NR-860 (Becton-Dickinson), aerobial vials with Bact/Alert (Organon) and Hemóline biphasic (bioMérieux). Besides, 10 ml of whole human blood from storage were added to each bottle, too. RESULTS: Bact/Alert was faster in detecting bacterial growth than Bactec with differences statistically significants for all of them, except for H. influenzae. On the other hand, Bactec was faster than Hemóline with differences statistically significant for all bacterial species except S. pneumoniae, which was first detected with manual biphasic method. The median time for detecting growth ranged between 10 h for E. faecalis and A. anitratus in Bact/Alert and 36 h for S. pneumoniae with Bactec. CONCLUSIONS: Bact/Alert detected growth earlier than Bactec, and was quicker than Hemóline. However, other factors have to be in account to choose a method. For instance, biphasic method has the advantage of showing growth in solid medium, whereas automatic systems, at the moment, only use liquid media.

Bacteria↗
PubMed1994

Pulmonary embolism in patients with upper extremity DVT associated to venous central lines--a prospective study.

We performed a prospective study in 86 consecutive patients with central vein catheter-related deep venous thrombosis (DVT) of the upper extremity, to evaluate the prevalence of pulmonary embolism (PE), and to identify clinical variables that would increase the likelihood of developing PE in an individual patient. Since upper-extremity DVT was established, all patients received intravenous heparin therapy. Then, a ventilation-perfusion lung scan was obtained within 24 h of DVT diagnosis, whether respiratory symptoms were present or not. Six points of clinical information were recorded on entering in the study, and then compared with the scintigraphic findings: age, sex, the underlying disease, the catheter material, the character of the infusate, and the duration of cannulation. Thirteen patients were considered to have PE. Sixty-six patients were finally classified as having a normal lung scan, and 7 patients were excluded from the study (because of indeterminate lung scan 6; because of femoropopliteal thrombosis simultaneously present 1). Two out of the 13 patients with PE subsequently died because of recurrent, massive embolism, despite adequate heparin therapy. PE was more commonly present in patients with polyvinyle chloride or polyethylene catheters (10/38, 26%) as compared to patients with either polyurethane or siliconized catheters (3/41, 7%; p < 0.05, Chi-Square test; Odds Ratio = 4.52, 95% CI 1.01-23.07). We conclude that PE is not a rare event in these patients, and it may be life-threatening even despite adequate heparin therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Multicentre evaluation of the Boehringer Mannheim Hitachi 911 system for homogeneous immunoassays.

A multicentre evaluation of the new analyser, Hitachi 911, is reported for three different classes of homogeneous immunoassays (latex assays, immunoprecipitation assays, and CEDIA assays). The evaluation protocol follows ECCLS, IFCC and NCCLS guidelines. Using patient samples and commercial controls, within run and between run coefficients of variation were less than 3% in most cases, but as high as 9.7% for some CEDIA and latex assays. All the assays were linear, either in the reference or the therapeutic range of the analytes. No interference by haemolysis, lipaemia or icterus was observed. The methods were compared with other commercial methods. Coefficients of correlation were higher than 0.94 for all the methods. However, there were differences of slope and intercept for rheumatoid factor, apolipoprotein A-I and apolipoprotein B. On the Hitachi 911, all of the eight methods give precise and accurate results, and compare well with other established methods on immunoassay dedicated analysers. The discrepancies observed could be ascribed to current problems of immunoassay standardization.

Chemistry, Clinical↗
PubMed1994

[Autoimmune hemolytic anemia associated with ulcerative colitis arising after colectomy].

Autoimmune hemolytic anemia is a rare, although not exceptional, complication of ulcerative colitis. This report presents a case of this association, which is noteworthy in that the hematologic picture appeared immediately after colectomy was performed due to colonic perforation. The features of the only three reported cases in which anemia developed after colectomy are reviewed, and the role of this surgical technique in the treatment of hemolytic anemia associated with ulcerative colitis is discussed. Although colectomy does not protect patients with ulcerative colitis from the onset of hemolytic anemia, we consider that proctocolectomy should be included among the therapeutic alternatives when this association is present, especially in the case of refractory colitis.

Adult↗
PubMed1994

Immunoradiometric assay of human intact proinsulin applied to patients with type 2 diabetes, impaired glucose tolerance, and hyperandrogenism.

We describe an immunoradiometric assay for human intact proinsulin in serum. In this method, one monoclonal antibody, coated onto polyacrylamide beads, cross-reacts with proinsulins and insulin. A sandwich is formed with intact proinsulin, split (65-66) proinsulin, and des (64-65) proinsulin binding with an 125I-labeled monoclonal antibody specific for an epitope at the intact B-C junction of proinsulin. Because split (65-66) and des (64-65) proinsulin concentrations are very low in serum, this assay essentially measures intact proinsulin. When we used 1-mL serum samples, the mean detection limit was 0.4 pmol/L. Mean proinsulin concentrations (pmol/L) were 3.4 (range 1-9.1) in healthy fasting subjects, 28.5 (9.7-101) in patients with type 2 diabetes (treated with metformin and sulfonylureas), 5.0 (1.6-9.3) in women with hyperandrogenism and normal insulinemia, 10.3 (2.6-36) in women with hyperandrogenism and hyperinsulinemia, and 8.5 (4.8-21.3) in patients with impaired glucose tolerance.

Adult↗