Search PubMed⌕ Search

Biomedical subjects

G Piédrola

Publications and source records attributed to G Piédrola.

At least 37 records · Page 2Linked to original sources
PubMed2000

Anti-hepatitic C virus antibodies hidden in circulating antibody/antigen aggregates in HCV-RNA positive patients.

The aim of this study was to determine whether antibodies to HCV can be hidden in immunocomplex aggregates in anti-hepatitis C virus (HCV) negative, HCV-RNA positive patients and whether their presence could be related to HCV viral load or HCV genotype. Sera (23 in toto) from patients with elevated alanine aminotransferase (ALT) levels and negative for anti-HCV but positive for HCV-RNA and the immunocomplex aggregates (precipitate with PEG 6000 and glycine 1 M) were studied. The sera were treated using a rapid, simple new ELISA which disrupted the immunocomplex aggregates. Sera from ten patients were tested anti-HCV positive after immunocomplex disruption. No correlation with age, sex, ALT level, viral load or HCV genotype was observed. In some patients anti-HCV antibodies were hidden in circulating antibody/antigen complexes which could be dissociated with a simple, inexpensive and rapid protocol; therefore it can provide a valuable addition to the diagnosis of HCV infection and it may prevent some cases of post-transfusion hepatitis.

Adult↗
PubMed1999

Lipoprotein(a) and other lipoproteins in hypothyroid patients before and after thyroid replacement therapy.

AIMS: To analyse the influence of thyroid hormones on serum lipoprotein(a) (Lp(a)) concentration and other lipid parameters, and hence potentially on coronary artery disease (CAD) risk. METHODS: Thirty-six patients with hypothyroidism and 165 age-matched control euthyroid subjects were evaluated in a cross- sectional study, determining thyroid function tests and fasting serum lipids and lipoproteins. In a follow-up study for those hypothyroid patients the same determinations were repeated after normalization of thyroid state by levothyroxine (L-T(4)) replacement therapy. Patients needing other treatments were excluded. At baseline, patients with hypothyroidism had significantly higher levels of Lp(a), total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), apolipoprotein (apo) A-I and apo B, and a higher TC/high-density lipoprotein cholesterol (HDL-C) ratio than control subjects. RESULTS: Severity of the hypothyroid state, expressed by serum thyroid-stimulating hormone, was correlated with serum levels of Lp(a), LDL-C, and TC (r= 0.64, 0.52, 0.49, P= 0.005, P= 0.033, P= 0. 048, respectively). The pretreatment Lp(a) levels were also correlated with those of posttreatment Lp(a)(r= 0.68, P= 0.002). All patients, who presented basal Lp(a) levels higher than 30 mg/dl, showed a decrease in Lp(a) concentrations by L-T(4)therapy, and these normalized in eight cases (22.2%). Euthyroid state gave rise to a significant reduction of serum Lp(a) by 32.3%, of LDL-C by 22. 8%, of TC by 17%, of apo A-I by 9.6%, and of apo B by 9.3%. After L-T(4)therapy, CAD risk, expressed as TC/HDL-C ratio, decreased by 19.9%. CONCLUSIONS: These results show that hypothyroidism is associated not only with elevated serum levels of LDL-C but also with elevated serum Lp(a) concentrations. Lp(a) levels may be at least partially modulated by thyroid hormone-dependent mechanisms, thus increasing the risk of developing premature atherosclerosis in hypothyroid state, that might be reduced by L-T(4)therapy.

Adult↗
PubMed1999

Evolution of insulin resistance in coronary artery disease patients on four different pharmacological therapies.

The objective of the study was to examine the evolution of insulin sensitivity in a group of patients with stable coronary artery disease receiving one of four different pharmacological therapies. Insulin sensitivity was evaluated using an insulin suppression test in 40 newly diagnosed patients with coronary artery disease and no previous history of metabolic disorders, who were not taking any medication which might affect insulin sensitivity. The insulin suppression test consisted of a constant infusion of glucose, insulin and somatostatin for 150 min; insulin resistance was estimated by determining the steady-state plasma glucose concentrations during the last 60 minutes of the test. The insulin sensitivity index was calculated by the formula: insulin sensitivity index = (glucose infusion rate/steady state plasma glucose concentrations) x 10(3). A second insulin suppression test was performed after 6 months' therapy with either isosorbide mononitrate, atenolol, diltiazem or captopril in 30 of the 40 patients. There were no differences between any of the groups before therapy was initiated. After 6 months, patients treated with captopril and, to a lesser extent, those treated with diltiazem showed statistically significantly decreased steady state plasma glucose concentrations and increased insulin sensitivity index compared to basal values. No statistically significant differences were found in the other two groups. We conclude that captopril and, to a lesser extent, diltiazem improve insulin sensitivity in patients with stable coronary artery disease.

Adrenergic beta-Antagonists↗
PubMed1999

Reliability of low-avidity IgG and of IgA in the diagnosis of primary infection by rubella virus with adaptation of a commercial test.

The detection of IgA and low-avidity IgG and antibodies in serum is a potentially useful marker of recent infection by a microorganism. We studied the reliability of IgG avidity and presence of IgA for the diagnosis of recent acute infection by rubella virus. Low-avidity IgG (Avy-EIA test) was determined with a modified commercial test using 8 molar urea (indirect ELISA, DiaSorin, Italy) and IgA was determined with a homemade indirect ELISA test. Twenty-five patients with recent primary infection by rubella virus (group I) and 50 healthy subjects (group II) were studied. In group I low-avidity IgG varied between 100 and 0% (67.3+/-21.8%); IgA was present in 24 patients (96%). In group II low-avidity IgG varied from 50.4 to 0% (19.8+/-16.9%). IgA was present in 2 subjects (4%). The sensitivity of the Avi-EIA and the IgA test was 92 and 96%, respectively; specificity was 100 and 96%, respectively. We conclude that both low-avidity IgG and IgA tests are helpful and reliable for the diagnosis of recent primary infection.

Adult↗
PubMed1999

Clinical reliability of IgG, IgA, and IgM antibodies in detecting Epstein-Barr virus at different stages of infection with a commercial nonrecombinant polyantigenic ELISA.

We studied the diagnostic reliability of a modification of the Enzygnost EBV test (Behringwerke, Germany) for the detection of IgG, IgA, and IgM antibodies (Abs) in the diagnosis of Epstein-Barr virus (EBV) disease. One hundred and twenty-three serum samples were studied: 14 asymptomatic subjects without EBV infection, 48 patients with primary infection, 46 subjects with past EBV infection (11 patients with other acute infections), 8 patients without EBV infection but with other viral infection, and 7 patients with probable acute clonal stimulation of B lymphocytes caused by different microorganisms. Enzygnost EBV is based on an ELISA test with a pool of viral antigens. In our series the reliability of IgM for the diagnosis of recent primary EBV infection was: sensitivity 100%, specificity 95%, positive predictive value 90.5%, and negative predictive value 100%. The IgG detection with Enzygnost was: sensitivity 98%, specificity 100%, positive predictive value 100%, and negative predictive value 91.7%. Only two subjects had positive IgA. The Enzygnost test is an efficient method for the diagnosis of EBV infection although a few IgM false positives can occur.

Antibodies, Viral↗
PubMed1998

GBV-C RNA presence in several high-risk groups of Spain.

GB virus C subtype (GBV-C) seems to share the same routes of transmission as other parenteral transmitted viruses. We have evaluated the prevalence of GBV-C in 247 patients with potential risk for GBV-C infection and in 91 healthy blood donors. The presence of GBV-C RNA was examined by polymerase chain reaction in serum samples. The 23.6% of parenteral drug users were GBV-C positive, 36.3% of them were also HIV infected. Moreover, 22.5 and 19% of sera from patients with HBV and HCV chronic hepatitis, respectively, but without apparent risk factors seemed GBV-C infected. Finally, the 6% of patients on hemodialysis were also positive. Therefore, these results suggest that GBV-C is transmitted by parenteral routes but other non-parenteral routes shared with HBV or HCV must be considered.

Adult↗
PubMed1998

A recombinant protein-based enzyme immunoassay for IgM antibody to human cytomegalovirus.

The reliability of an enzyme-linked immunosorbent assay (ELISA) which used recombinant antigen to detect human cytomegalovirus IgM was studied. Serum samples from each of 283 children aged 5 +/- 2 years were studied. In all samples the anti-IgM antibodies were investigated with the ELISA techniques Enzygnost (Behring) and ETI-Cito (Sorin) which were both based on whole viral particles, and OPUS (Behring) based on recombinant antigen. Of the samples, 254 (89.4%) were negative with all three tests. The 29 remaining samples were positive with one or two of the three techniques. The diagnostic efficacy of Enzygnost, ETI-Cito and OPUS, respectively, was for sensitivity of 50%, 66.7% and 50%, and for specificity of 100%, 95.6% and 96%, respectively. The results with each of the three ELISAs did not differ widely and their diagnostic efficacy was similar. The method based on recombinant antigen was not found to be more effective than tests based on whole viral particles.

Antibodies, Viral↗
PubMed1998

[Correlation between the presence of cytomegalovirus antibodies and antigen in blood leukocytes for the diagnosis of primary active infection].

BACKGROUND: The diagnosis of cytomegalovirus infections measuring IgG or IgM antibodies has a high rate of false positive or negative results, specially in immunocompromised patients. AIM: To compare the diagnostic yield of antibodies against cytomegalovirus with the measurement of the antigen in peripheral leukocytes. MATERIAL AND METHODS: Forty three blood samples coming from pediatric patients with suspected cytomegalovirus infections were analyzed. Low affinity IgG and IgM antibodies against Epstein Barr virus and cytomegalovirus, using indirect ELISA assays, and the virus antigen in peripheral leukocytes, using a commercial immunoperoxidase assay, were measured. RESULTS: Seven patients had positive IgM antibodies against cytomegalovirus. In five of these the viral antigen was detected in peripheral leukocytes. Twenty patients had positive antibodies against Epstein Barr virus, and in 16 patients all serologic tests were negative. CONCLUSIONS: There is not a good correlation between antibodies against cytomegalovirus and the detection of its antigen in patients with acute infections.

Adolescent↗
PubMed1998

[Efficacy of two gene species in the serological diagnosis of Borrelia burgdorferi infections].

BACKGROUND: There is phenotypic and genetic variability among the species Borrelia burgdorferi that produces Lyme disease. Three gene species and seven serotypes have been defined. AIM: To study the efficacy of two gene species in the serological diagnosis of Borrelia burgdorferi infections in Granada, Spain. MATERIAL AND METHODS: One thousand sixty nine sera coming from 1,251 subjects without Lyme borreliosis were analyzed. These subjects were studied for health or pregnancy controls, differential diagnosis of viral disease, diagnosis of syphilis, neurological or rheumatic diseases. In all samples, antibodies against Borrelia burgdorferi (B31 and Pko strains) and against Treponema pallidum were investigated. Screening tests (ELISA and hemagglutination) were followed by confirmations tests for positive samples (Western Blot IgG strain B31 and FTA-abs respectively). A clinical and laboratory follow up was done for subjects with positive serological tests. RESULTS: The global rate of positive antibodies against Borrelia burgdorferi B31 was 8.31% and against the strain Pko was 0.64%. Western blot was negative in 36% of subjects with positive ELISA B31. The distribution of antibodies against the strain B31 was acute herpes virus infection in 16%, gestation in 3%, HIV infection in 6.4%, T pallidum infection in 36%, rheumatic diseases in 25%, neurological diseases in 17.5% and health controls in 7.4%. The percentage of positive Western Blot analyzes were 0.8, 2.1 and 0.4% respectively. A reversion of positive ELISA tests was observed in 6 subjects. CONCLUSIONS: The disparity in rates of antibodies against Borrelia burgdorferi in different geographic regions may be due to differences in the serological tests used. The high rate of false positive ELISA tests underscores the need to use other serological tests.

Antibodies, Bacterial↗
PubMed1998

GBV-RNA detection by polymerase chain reaction with several primer pairs.

The identification of specific genomic sequences of GB viruses (GBV) has made it possible to utilize the polymerase chain reaction (PCR) for evaluation of the viraemia. Several studies have demonstrated the RNA-GBV presence in sera from different patients amplifying several portions of the virus. In this investigation the PCR results when different regions of GBV (NS3, UTR and putative CORE and E1) were amplified in the same sample. In 245 samples studied there were two (0.8%) discordant results and the NS3 primer showed the greatest sensitivity. The lowest percentage of positivity was obtained with CORE-E1 primers. These results could be because the nucleocapside/E1 region was extremely variable in length and sequences, although degenerated primers and probes were used. Discordances were attributable to laboratory errors, variability in the viral genome, the presence of primer inhibitors in samples or a low viral load.

DNA Primers↗
PubMed1998

Subtype distribution among intravenous drug users with chronic type C hepatitis in southern Spain.

The hepatitis C virus (HCV) subtype distribution among intravenous drug users (IVDU), and patients without this risk of acquiring HCV infection, was evaluated. The patients included in the study were 51 with chronic type C hepatitis (36 IVDU and 25 coinfected by HIV-1), and 31 on haemodialysis. Genotyping was performed on 71 viraemic patients, with the following distribution: 25.4%, 1a; 54.9%, 1b; 8.5%, 3a; 7%, mixed (1a, 1b; 3a, 1a; 3a, 1b; 2 x 3a, 2a); 1.4%, 4; and 2.8%, non-typeable. When subtypes were related to IVDU practice, the statistical significance was p < 0.01 for subtypes 1a (48.5% vs 7.5%, for IVDU and non-IVDU, respectively) and 1b (16.1% vs 85.1%). No relation between HIV-1 coinfection and subtype distribution was observed among IVDU patients. The results suggest that among young IVDU of Southern Spain the emerging HCV subtype is 1a.

Antibodies, Viral↗
PubMed1997

Behaviour of IgG antibody avidity for the antigen and of IgA antibody in active cytomegalovirus, Epstein-Barr virus, herpes simplex virus and human herpes virus 6 infections. Adaptation of a commercial test.

The clinical value of specific IgA and IgG antibody avidity to herpes simplex virus, cytomegalovirus, Epstein-Barr virus and human herpes virus 6 for the detection of active disease and primary infection, respectively, was evaluated. The IgG avidity test, with a break point of 55%, for the detection of primary infection, and of the IgA test for the detection of disease, were associated with a sensitivity of 97% and 64%, respectively; specificity of 100% and 82%; a positive predictive value of 100% and 76%; and a negative predictive value of 96% and 72%, respectively.

Adult↗
PubMed1997

Relationship between insulin sensitivity and dehydroepiandrosterone sulfate in patients with ischemic heart disease.

Insulin resistance has been related to the pathogenesis and development of ischemic heart disease (IHD). Dehydroepiandrosterone sulfate (DHEA-S) has been suggested as the possible link between these two entities. The aim of this study was to clarify the relationship between insulin resistance and DHEA-S in patients with IHD. Thirty-two male patients with newly-diagnosed IHD and without known metabolic disorders and 11 healthy matched controls were included in this study. Insulin sensitivity was assessed by an insulin suppression test, and DHEA-S levels were measured before the test (basal) and at the end of the test (during hyperinsulinemia). Insulin resistance, defined as an insulin sensitivity index (ISI) below the normal range derived from the control group, was present in 78% of IHD patients; they also displayed, as a group, lower ISI (P < 0.0001) than controls. DHEA-S levels were lower in IHD than in controls, both basal and during hyperinsulinemia (P < 0.05). DHEA-S levels decreased when hyperinsulinemia was achieved, both in IHD patients and controls (P < 0.0005). The magnitude of the decrease was the same in both groups. No correlation between ISI and DHEA-S levels was found. In conclusion, insulin sensitivity is lower in patients with IHD, even when major metabolic abnormalities associated with insulin resistance are excluded. These patients also show decreased DHEA-S levels, which are further reduced when acute induced hyperinsulinemia is achieved, although, as the decline was similar to that of controls, there does not seem to be resistance to this particular action of insulin.

Acute Disease↗
PubMed1997

Malignant pheochromocytoma of the bladder: current controversies.

Urinary bladder pheochromocytoma is an uncommon tumor that produces hypertensive crises coinciding with micturition. It is usually benign, with less than 20 cases with evidence of metastasis described to date. We present a rare case of a malignant bladder pheochromocytoma with regional metastasis, where the pathological and scintigraphic findings are described. The controversy about pathology diagnosis, treatment and prognosis of this unusual tumor is discussed.

3-Iodobenzylguanidine↗