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Biomedical subjects

G Piédrola

Publications and source records attributed to G Piédrola.

At least 19 recordsLinked to original sources

Activity of tigecycline against clinical isolates of Staphylococcus aureus and extended-spectrum beta-lactamase-producing Escherichia coli in Granada, Spain.

We evaluated the in vitro activity of tigecycline using the Etest and disk diffusion method according to Clinical and Laboratory Standards Institute guidelines against clinical isolates of methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant S. aureus (MRSA) as well as for CTX-M-9 extended-spectrum beta-lactamase (ESBL)-producing Escherichia coli and SHV ESBL-producing E. coli. All isolates were susceptible to tigecycline according to US Food and Drug Administration cut-off points. There were no differences in the activity of tigecycline between MSSA and MRSA isolates or between the presence of either type of ESBL. For each type of microorganism studied, we established the equation relating the minimum inhibitory concentration to the diameter of the zone of inhibition.

Anti-Bacterial Agents↗

[A study of clinical response to antibiotic treatment in subjects with chronic bacterial prostatitis].

A study was carried out on the clinical response to antibiotics in 105 patients with chronic bacterial prostatitis. Two groups of patients were compared in a retrospective study. The results of rectal examination, ultrasound scan, microbiological analysis, and response to different antibiotic therapy regimens were compared. There was a high incidence of perineal-testicular pain and sexual potency reduction; prostate congestion and pain on rectal examination were frequently reported. All the patients had positive microbial cultures, with Gram-negative microorganisms being predominantly isolated. Following the administration of different antibiotic therapy regimens, symptoms either disappeared or diminished, irrespective of whether positive cultures remained. A poorer clinical response was observed in patients with positive prostate ultrasound and rectal examination, and with isolated Gram-negative bacilli. No differences were observed between either group in clinical response to different antimicrobial regimens.

Adult↗

Multiple sclerosis and human herpesvirus 6.

BACKGROUND: A possible but as yet unproven relationship has been proposed between the onset or persistence of multiple sclerosis (MS) symptoms and herpesviruses, including, most recently, human herpesvirus 6 (HHV-6). A study was conducted to investigate the presence of HHV-6 DNA and the synthesis of antibodies against HHV-6, cytomegalovirus (CMV) and Epstein-Barr virus (EBV) in serum and cerebrospinal fluid (CSF) of patients with MS. MATERIALS AND METHODS: PCR and ELISA were used to detect HHV-6 DNA and specific antibodies against HHV-6, CMV and EBV in 211 samples (139 sera and 72 CSF). There were three groups of samples: group I, paired samples of serum and CSF from 41 MS patients; group II, paired samples of serum and CSF from 31 patients with neurological diseases other than MS (OND); group III, 67 serum samples from 27 different MS patients undergoing serologic follow-up. RESULTS: No HHV-6 DNA was found in any sample. Group I sera showed elevated anti-HHV-6 IgG and IgA levels. In group II, anti-CMV IgG was detected in one CSF sample and anti-HHV-6 IgM in one serum sample. Group III sera showed high concentrations of anti-HHV-6 IgG, IgA and IgM. CONCLUSION: Given the clinical implications of the presence of antibodies against HHV-6 in MS patients, a viral reactivation cannot be excluded as an environmental factor.

Adult↗

Chlamydia pneumoniae DNA in the arterial wall of patients with peripheral vascular disease.

BACKGROUND: Chlamydia pneumoniae is a human respiratory pathogen that has recently been related to the genesis of symptomatic atherosclerosis. C. pneumoniae has been studied more widely in relation to coronary atherosclerosis than to peripheral arterial occlusive disease (PAOD). The present study aimed to retrospectively analyze the presence of C. pneumoniae DNA in patients with PAOD. MATERIALS AND METHODS: A seminested PCR method was applied on 85 samples from 71 patients with PAOD secondary to surgical treatment. The control group comprised 50 patients with chronic superficial venous insufficiency who required varicose resection surgery. RESULTS: The number of patients, number of samples studied and percentage of patients found to be positive in the PCR study were 17, 18 and 59%, respectively, for arteries of the lower extremities; 15, 16 and 60% for aneurysm of the abdominal aorta; 22, 23 and 73% for carotid stenosis and 17, 18 and 65% for aortic stenosis. C. pneumoniae DNA was found in six external pudendal arteries (12%) of the control group, significantly lower than the incidence in the patient group (p < 0.0001). CONCLUSION: A causal relationship between chronic C. pneumoniae infection and PAOD cannot be ruled out. On the contrary, the high incidence of C. pneumoniae DNA detected in our patients suggests that C. pneumoniae infection may play some role in the pathogenesis of peripheral vascular disease.

Aged↗

Antibiotic susceptibility of bacterial strains isolated from patients with community-acquired urinary tract infections.

Isolates from urine samples obtained during 1999 were identified and their susceptibility to antimicrobial agents studied along with any production of extended-spectrum beta-lactamases (ESBL) by Escherichia coli and Klebsiella pneumoniae. A total of 13774 samples were analysed using an automatic system for the detection of bacterial ATP (Coral, USA). Of these samples, 49% were reported to be positive and uncontaminated; bacteria most frequently isolated were E. coli (47%), Proteus mirabilis (7%), Enterococcus faecalis (6%) and K. pneumoniae (5%). The susceptibility studies showed 37% E. coli strains resistant to amoxycillin+clavulanate 33% to cotrimoxazole and 22% to ciprofloxacin. Seven strains of E. coli produced ESBL. Thirteen per cent of strains were resistant to cefuroxime but only (1%) to fosfomycin. Resistance to nitrofurantoin in K. pneumoniae was 38%. P. mirabilis showed 52% resistance to cotrimoxazole and 13% Staphylococcus aureus, were methicillin-resistant. E. faecalis did not show any special resistance to normal medication. Fosfomycin continued to show high activity against Gram-negative bacilli. However, enterococci, some species of staphylococci and yeasts were difficult to treat empirically. ESBL were detected in the isolates of E. coli and there were some methicillin-resistant strains of S. aureus.

Anti-Bacterial Agents↗

HGV RNA sequences in liver and PBMC.

HGV has been identified in patients with chronic hepatitis of unknown aetiology and the possibility that HGV may be the cause has been raised. We have analysed liver biopsies and PBMC (peripheral blood mononuclear cells) from 80 patients with chronic hepatitis and HGV-RNA in serum by PCR. In ten patients HGV-RNA was detected in liver, in five patients it was detected in PBMC and seven were positive in both specimens by PCR. Whether this agent resides and replicates in hepatocytes remains controversial and needs more studies.

Base Sequence↗

White blood cell count and insulin resistance in patients with coronary artery disease.

White blood cell (WBC) count has been shown as a risk factor for cardiovascular disease. Decreased insulin sensitivity has been suggested as the link between these two entities. Our aim was to study the potential relation between insulin sensitivity and WBC count in patients with coronary artery disease. In order to assess insulin sensitivity, we performed 83 insulin suppression tests before and after therapy in 50 patients with coronary artery disease. Patients with glucose intolerance, arterial hypertension or obesity were excluded. Steady-state plasma glucose (SSPG) and insulin sensitivity index (ISI=1 000 x glucose infusion rate/SSPG) were considered as a measure of insulin sensitivity. WBC count, blood platelets, fibrinogen, microalbuminuria, creatinine, urea and HbA1c were also assessed. Simple and multiple correlation analysis were carried out between insulin sensitivity parameters and the other variables measured. There were significant correlation between SSPG and WBC count (r=0,32: p=0,003) and microalbuminuria (r=0,28: p=0,012). We also found statistically significant correlation between ISI and WBC count (r=0,27: p=0,015) and microalbuminuria (r=0,24: p=0,029). No correlation could be detected between either SSPG or ISI and the other variables measured. In multiple regression analysis, WBC count was found to be an independent predictor of both SSPG (p<0.01) and ISI (p<0.05). Our data show the existence of a significant relationship between decreased insulin sensitivity and WBC count in patients with coronary artery disease. The results of this study suggest that an elevated WBC count could be postulated as part of the insulin resistant syndrome.

Aged↗

An evaluation of a polyantigenic ELISA to detect Epstein-Barr virus reactivation.

The diagnostic reliability of the Enzygnost EBV test (DadeBehring, Germany) for the detection of IgG and IgA antibodies in the diagnosis of Epstein-Barr virus (EBV) recurrent disease was investigated. Of 81 serum samples examined there were fourteen asymptomatic patients without EBV infection, 46 with past EBV infection, and 21 patients with EBV reactivation. The Enzygnost EBV test was based on an enzyme-linked immunosorbent assay with a pool of viral antigens. The reliability of IgG at >650 IU/ml, and IgA for the diagnosis of reactivation or chronic persistent EBV infection gave 100% sensitivity, 83.3% and 98.3% specificity, respectively. The data indicated that the appearance of EBV IgA was associated with EBV reactivation together with clinical manifestations.

Antibodies, Viral↗

Antibodies to Borrelia burgdorferi in European populations.

We compared the antibodies to B. burgdorferi in three different populations in order to evaluate the diagnostic reliability of Lyme borreliosis serologic analysis. The subjects included 25 patients with Lyme borreliosis (Group 1); 50 patients with diseases of unknown cause, B. burgdorferi ELISA-positive in serum and without B. burgdorferi infection (Group 2); and 1,251 individuals without Lyme borreliosis (Group 3). All samples were tested for B. burgdorferi B31 and B. afzelii antigens using ELISA. The positive results of the ELISA B. burgdorferi B31 assay were confirmed with Western blot for the same strain. In Group 3, 162 (12.9%) patients were ELISA positive for B. burgdorferi B31, while only 6 (0.6%) patients had IgG ELISA antibodies to B afzelii. Bands in WB were detected in 104 (8.4%) of the Group 3 subjects. The bands found to be most reliable for the identification of strain B. burgdorferi B31 by IgG WB were those representing the 93, 39, 34, and 23-kDa proteins. Our results show that serologic diagnosis of Lyme borreliosis is far from clearly established. To date, the only reliable criteria are clinical ones correlated with laboratory evidence.

Adolescent↗

Detection of mycobacterial DNA in papulonecrotic tuberculid lesions by polymerase chain reaction.

Tuberculids are a heterogeneous group of cutaneous lesions. Recent discoveries of M. Tuberculosis DNA in these lesions by PCR suggest that M. tuberculosis could play a role in their pathogenesis. The aim of this study was to demonstrate the presence of M. tuberculosis DNA by polymerase chain reaction in papulonecrotic tuberculid lesions. Skin biopsy specimens from ten patients with papulonecrotic tuberculid lesions (histopathologic features) were studied. All of them tested solidly positive in a tuberculin intradermal test. A gene-amplification PCR, using primers capable of amplifying DNA in the M. tuberculosis complex, was performed to detect M. tuberculosis DNA in the lesions. A 285-bp sequence specific of M. tuberculosis complex was amplified and confirmed by Southern-blot hybridation with a 32 p 5'-labelled internal probe. No inhibitors were detected in the negative PCR samples. The PCR technique makes the detection of mycobacterial DNA in tuberculids a possibility, and therefore provides a rational basis for antituberculous therapy and for the clinical management of these disorders.

Biopsy↗

Prevalence and viral persistence of TT virus in patients on hemodialysis.

The aim of this study was toevaluate the prevalence of TT virus (TTV) in 107 hemodialysis patients and 100 healthy individuals. Sixteen percent of hemodialysis patients and 2% of the control population were TTV positive (P<0.001). Sex, time on dialysis, transfusions, and alanine aminotransferase levels were not related to the presence of TTV DNA. TTV was more frequent in patients 50 to 70 (12/51) years of age and persisted in the serum of six of nine patients 8 months later. TTV was found in peripheral blood mononuclear cells of all patients with chronic infection, and sequence variation was noted in the peripheral blood mononuclear cells of two patients. No relationship between TTV infection and hepatitis was observed. Viral persistence and nonparenteral transmission may be possible in patients on hemodialysis.

Aged↗

GB virus C in patients with liver disease of unknown etiology.

To assess the prevalence of GBV-C in patients suffering unknown liver disease we have investigated the GBV-C-RNA in serum of 54 patients: 10 with acute and 32 with chronic non-A-E hepatitis (16 active and 16 persistent), 10 with hepatocellular carcinoma, 2 diagnosed with hepatic fulminant failure, and 91 healthy blood donors (control). PCR with primers from NS3 helicase region was performed and the product was identified by a double strand DNA enzyme immunoassay. GBV appears to infect 40 and 31% of acute or chronic non-A-E hepatitis respectively. Also the GBV genome was found in 1 in 10 samples of hepatocarcinoma, in 2 cases of fulminant hepatitis, and in 1 in 91 of the control group. In spite of these results the role of GBV in the etiology of liver diseases has to be analyzed in more comprehensive studies.

Adult↗

Clinical utility of a competitive ELISA to detect antibodies against Treponema pallidum.

Screening for Treponema pallidum infection is carried out on a large human population. To reduce costs, fewer tests which still offer adequate sensitivity and specificity could be performed. We studied the reliability of a novel indirect ELISA method to test for this infection. Several panels of sera were used that corresponded to 40 primary infections (group 1), 13 recurrences (group 2), 348 latent infections (group 3), 5 samples with anticardiolipin antibodies (group 4), 15 samples from patients with Lyme borreliosis (group 5), and 400 samples from blood donors and healthy pregnant women (group 6). The ELISA showed a global sensitivity and specificity of 100 and 99.5%, respectively. Our evaluation shows that Enzygnost Syphilis is a sensitive, specific, and simple test to screen for this infection.

Adult↗

Evaluation of two reverse transcription polymerase reaction assays (GEN ETI-K HGV RNA and LCx GBV-C assay) for the detection of GB virus C/hepatitis G virus RNA in clinical samples.

Our study evaluates the analytical performance of two amplification methods in the detection of GB Virus C/Hepatitis G Virus, GEN ETI-K HGV RNA (GEN) and the LCx GBV-C Assay (LCx). GB Virus C RNA was detected by at least one test in 58/315 samples (18.41%). Fifty-five samples (17.46%) were positive by the GEN method and 51 samples (16.19%) by the LCx method. The same rate of detection was found for 71 haemodialysis patients and 18 non-A non-E hepatitis. Method based differences in prevalence were observed for patient samples from the general population, 8/106 (7.55%) positive by GEN vs 7/106 (6.60%) by LCx; and HIV infected patients, 26/98 (26.53%) vs 23/98 (23.46%). For chronic type C hepatitis 10/22 (45.5%) were positive by both methods, with two samples discordant. Overall, discordance was observed for ten samples, with seven positive only by the GEN ETI-K HGV RNA, and three positive only by the LCx GBV-C Assay. An additional evaluation of serial samples, from chronic type C hepatitis patients under interferon treatment, revealed three samples which were positive only by the GEN method. Results were 100% concordant for patients under haemodialysis and for non-A non-E hepatitis, 95.9% in the HIV positive group, 90.9% in the chronic type C hepatitis group, and 97.1% in the general population group. Overall, a 97.2% of concordance was found between methods. Both tests have a similar diagnostic performance, though in our opinion, LCx GBV-C Assay better suits the requirements of a clinical microbiology diagnostic laboratory.

Flaviviridae↗

Genomic variability of hepatitis G virus/GBV-C at the NS3 region: clinical implications.

A new hepatitis virus, named GBV-C or hepatitis G virus (HGV), closely related to the hepatitis C virus (HCV), was identified in 1994. The existence of quasispecies in HCV is very important. In this work polymerase chain reaction amplification of the NS3 region of the genome of GBV-C/HGV and heteroduplex mobility assay (HMA) were combined to investigate the presence of quasispecies in patients with chronic infection by GBV-C/HGV. Patients with chronic infection by HCV were used to validate the method. The HMA was also used to investigate the similarity between the cited genomic region of GBV-C/HGV in different infected patients. A high degree of heterogeneity was found for HGV existing as quasispecies and as differences between samples. This is of extreme importance because of the intrinsic clinical and pathogenic implications of quasispecies of a virus capable of producing disease, and is in accord with other studies which report on the genomic variability of the NS3 region.

Antiviral Agents↗