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Biomedical subjects

J Ruiz

Publications and source records attributed to J Ruiz.

At least 109 records · Page 6Linked to original sources
PubMed2000

Resolution of high-molecular-weight components in lipopolysaccharides of Escherichia coli, Morganella morganii, Citrobacter freundii and Citrobacter diversus strains with sodium dodecyl sulfate polyacrylamide gels.

The use of 0.5% sodium dodecyl sulfate in polyacrylamide separation gels allowed the resolution in several bands of high-molecular-mass components in smooth lipopolysaccharide of bacterial outer membrane from Escherichia coli, Morganella morganii, Citrobacter freundii and Citrobacter diversus. With or without 0.1% SDS, however, such a result was not possible.

Citrobacter↗
PubMed2000

Screening for gestational diabetes: variation in guidelines.

OBJECTIVE: To compare published guidelines concerning screening for gestational diabetes. STUDY DESIGN: Systematic search and comparative analysis of published guidelines. Appraisal of guidelines quality. Simulation analysis. RESULTS: Ten published guidelines proposed either universal screening (5), selective screening (3) or screening when clinically indicated (2). Variations of testing schedules and blood glucose thresholds were observed. The quality of the published guidelines was low, on average 22 (8-51) percentage points on the assessment scale. These differences would have led to large variations in the number of patients to be screened. CONCLUSIONS: Large variations between guidelines have been observed which would translate in large practice variations, if the guidelines were systematically applied. These variations are partially explained by the absence of definite evidence that universal or selective screening for gestational diabetes do more good than harm on infant and maternal health. The methodology of developing guidelines should be more evidence based, systematic and explicit.

Adult↗
PubMed2000

Decreased permeability and enhanced proton-dependent active efflux in the development of resistance to quinolones in Morganella morganii.

Five quinolone-resistant strains were developed from a clinical Morganella morganii isolate (M1 strain) which was susceptible to nalidixic acid and fluoroquinolones. All five in vitro selected mutants showed diminished norfloxacin accumulation and two of them also decreased the expression of the AgO in the outer membrane lipopolysaccharide with respect to their parent strain and to the M. morganii NCTC-235 type strain. Likewise, the M1 strain did not express a 37-38 kDa protein and accumulated less norfloxacin than the M. morganii NCTC-235 strain. The decreased norfloxacin uptake in the five mutants compared with the M. morganii NCTC-235 strain was due to an enhanced proton-dependent active efflux plus a pre-existent decreased expression of a 37-38 kDa protein in the parent strain.

4-Quinolones↗
PubMed2000

17. Utility of Metabolic Imaging in Oral Squamous Cell Carcinoma (SCC) Staging. Experience in 30 Patients.

Purpose: SCC represents nearly 90% of all oral malignancies, with an increasing incidence. Accurate Tumour-Node-Metastasis staging (TNM) is mandatory for planning surgical options and chemotherapy-radiotherapy management. Positron Emission Tomography (PET) using 18F-Fluorodeoxyglucose (FDG) provides functional information about tumoral tissues that may improve preoperative staging obtained by conventional morphologic procedures (CT-MRI). The purpose of this study is to evaluate the accuracy of FDG-PET in oral SCC staging and to compare those data from conventional and PET studies according to the pathologic results obtained from surgical specimen.Methods: A prospective study of 30 patients was carried out, through a 26 months period. Inclusion criteria include positive biopsy for Oral SCC, no other malignancies during the past 5 year and surgery as preferred therapeutic option. All patients underwent CT, MRI, and FDG-PET studies consecutively. Results obtained from conventional and PET preoperative staging were compared with those from postoperative histopathological studiesResults: FDG-PET modified preoperative staging obtained by conventional morphologic studies in 21% cases, which was confirmed postoperatively by histological findings. Kappa test showed higher values for PET studies (0.89) than conventional studies (0.41), when compared with postoperative controlConclusion: FDG-PET may be helpful to improve the accuracy of conventional studies in oral SCC preoperative TNM staging, although no definitive conclusions can be withdrawn due to the limited size of the sample. Modifications of preoperative staging showed by PET are a matter of controversy and must be kept in mind for further studies.

Journal Article↗
PubMed2000

Gemcitabine for relapsed or resistant lymphoma.

BACKGROUND: Gemcitabine therapy has not been widely assessed in the treatment of hematological malignancies. We have examined the efficacy and safety of gemcitabine in patients with relapsed or resistant lymphoma. PATIENTS AND METHODS: Gemcitabine (1 g/m2) was given weekly for 7 consecutive weeks, followed by a week off treatment. The drug was then given for 3 consecutive weeks, followed by a week off treatment; this regimen was continued until disease progression or drug intolerance. Fifteen patients have enrolled. Most have been extensively pre-treated for advanced diffuse large-cell or mantle-cell lymphoma. RESULTS: The drug was well tolerated; no patient suffered treatment-related sepsis, hemorrhage or death. Non-hematopoietic toxicity led to discontinuation of gemcitabine therapy in two patients. Dose reductions or delays were required for about two-thirds of treatments. Of 13 evaluable patients, one had a complete response, 3 a partial response, 3 stable disease, and 6 disease progression. After 6 infusions of gemcitabine, a patient with advanced Hodgkin's disease has had a complete remission lasting 21 months. CONCLUSIONS: Gemcitabine has substantial activity and acceptable toxicity in heavily pre-treated patients with advanced lymphoma. Further study is warranted.

Aged↗
PubMed2000

Ultrastructural analysis of the eggshell: contribution of the individual calcified layers and the cuticle to hatchability and egg viability in broiler breeders.

1. Scanning electron microscopy was used to assess the relationship between the layers of the eggshell and egg viability. The relative thickness (absolute and %) of the mammillary, palisade, vertical crystal and cuticle layers relative to the total eggshell were measured over a 30-week laying period in 2 broiler breeder lines having different hatchability rates. 2. A significant difference in hatchability of 5.5% between the breeder lines was observed. However, there was no significant difference in either egg viability or fertility between lines. 3. The relative thickness of the individual calcified layers and the cuticle did not differ between lines. Therefore, variations in the thickness of the individual eggshell layers are unlikely to explain the 5.5% difference in hatchability rate between lines. 4. The thickness of the calcified region did not alter as the broiler hen aged. However, the percent contribution of each calcified layer significantly differed over the egg production period. 5. The cuticle was significantly thinner at the beginning and at the end of the laying period compared to 38 weeks of age. 6. No significant correlation was observed between egg viability and the relative thicknesses of the mamillary, palisade or cuticle layers. In contrast, there was a positive relationship between egg viability and the thickness of the vertical crystal layer. 7. The percent contribution of the mammillary and palisade layers was similar in the thinnest and thickest eggshells, suggesting conservation of the proportions of these layers independent of eggshell thickness.

Animals↗
PubMed2000

Meningitis caused by Pseudallescheria boydii treated with voriconazole.

Meningitis caused by Pseudallescheria boydii is an uncommon infection of the CNS that usually has a poor prognosis and a difficult treatment. We describe a case of chronic meningitis caused by P. boydii in an immunocompetent host that was successfully treated with voriconazole, a new antifungal agent.

Adult↗
PubMed2000

In vitro selected fluoroquinolone-resistant mutants of Citrobacter freundii: analysis of the quinolone resistance acquisition.

Ten quinolone-resistant mutants of Citrobacter freundii, which were selected in vitro with fluoroquinolones from two clinical isolates, were studied. The parent isolates were susceptible to quinolones in spite of showing a single substitution in the GyrB (His-417 --> Leu). No change was observed in the outer membrane proteins or in the lipopolysaccharide in any of the ten mutants studied with respect to their parent isolates. The development of quinolone resistance in selected mutants was associated with the appearance of a substitution in the GyrA (Thr-83 --> Ile) in nine of the ten mutants plus enhanced active efflux in all of them.

Anti-Infective Agents↗
PubMed2000

Quinolone resistance in enterotoxigenic Escherichia coli causing diarrhea in travelers to India in comparison with other geographical areas.

Enterotoxigenic Escherichia coli isolates were identified as a cause of traveler's diarrhea in 82 of 520 (16%) patients and tested for resistance to seven antimicrobial agents. Thirty patients (36%) needed antimicrobial therapy: 17 (56%) for persistence of symptoms and 13 (44%) for severity of symptoms. Ampicillin, tetracycline, and trimethoprim-sulfamethoxazole resistance was high. Chloramphenicol showed moderate activity, and amoxicillin plus clavulanic acid, nalidixic acid, and ciprofloxacin showed very good activity. Five nalidixic acid-resistant strains were isolated, four from patients visiting India.

Diarrhea↗
PubMed2000

Salmonella enterica serovar virchow with CTX-M-like beta-lactamase in Spain.

Four Salmonella enterica serovar Virchow strains resistant to broad-spectrum cephalosporins were isolated from patients with gastroenteritis in 1997 and 1998 in Murcia and Barcelona, Spain. The isolates expressed a beta-lactamase with a pI of about 8 and a positive PCR when specific primers for CTX-M-9 were used. These results suggest the presence of a CTX-M-9 beta-lactamase in these strains.

Drug Resistance, Microbial↗
PubMed2000

Pathological and virological findings in patients with persistent hypertransaminasaemia of unknown aetiology.

BACKGROUND: The histopathological spectrum and role of hepatitis viruses in cases of hypertransaminasaemia of unknown aetiology have not been correctly analysed in a sufficiently large number of patients. METHODS: We studied 1075 consecutive patients referred for liver biopsy because of elevation of alanine aminotransferase (ALT) levels for more than six months. From this population we selected those cases in whom the aetiology could not be defined from clinical, biochemical, and serological data obtained before biopsy. In these patients liver biopsies were reviewed, and hepatitis B virus (HBV)-DNA and hepatitis C virus (HCV)-RNA were assayed in serum by polymerase chain reaction (PCR). Serum hepatitis G virus (HGV)-RNA was determined by PCR in 74 patients. RESULTS: Of 1075 patients studied, the cause of the increased serum ALT levels remained elusive after appropriate testing in 109 patients (10.1%). Liver biopsies from these patients showed non-specific changes in 32.7% of cases, non-alcoholic steatohepatitis (NASH) in 15.8%, and chronic hepatitis or cirrhosis in 51.5%. HBV-DNA and/or HCV-RNA was detected more frequently in cryptogenic liver disease than in healthy blood donors (26.7% v 3.4%; p<0.001). HGV-RNA was found in only one patient. The proportion of cases with detectable HBV-DNA or HCV-RNA was 14.3% in patients with non-specific changes or NASH, 30.7% in patients with chronic hepatitis, and 61.5% in patients with cirrhosis. Cirrhosis was found more frequently in patients with positive HBV-DNA and/or HCV-RNA in serum than in those who tested negatively (p=0.005). CONCLUSIONS: In our series, patients in whom biochemical and serological data did not determine the aetiology of the disease represented 10% of all cases referred for liver biopsy for persistent elevation of serum transaminases. Approximately 50% of patients had chronic hepatitis or cirrhosis and the remainder had NASH or non-specific changes. Occult viral infections were found in a high proportion of cases in the first group and in a low percentage of patients in the second.

Alanine Transaminase↗
PubMed2000

Promoter polymorphism T(-107)C of the paraoxonase PON1 gene is a risk factor for coronary heart disease in type 2 diabetic patients.

The serum enzyme paraoxonase (PON) protects LDLs from oxidative stress. We recently identified promoter polymorphisms of the PON gene that strongly affect gene expression and serum levels of the enzyme. The present study tested the hypothesis that promoter polymorphism T(-107)C could be a risk factor for vascular disease in type 2 diabetic patients by virtue of its ability to modulate serum concentrations of the antioxidant enzyme. The low-expressor genotype (TT) was associated with significantly lower serum PON concentrations, and it was over-represented in type 2 diabetic patients with coronary heart disease (CHD) (TT vs. TC+CC: odds ratio [OR] 1.64 [95% CI 1.03-2.61], P < 0.05). The association of the low-expressor genotype with an increased risk of disease was independent of other risk factors, including the coding region Q191R polymorphism (OR 2.12 [95% CI 1.19-3.70], P = 0.01). However, an interaction of the promoter polymorphism with the Q191R polymorphism, which was previously identified as an independent risk factor, was observed. The low-expressor promoter allele (-107T) associated with the high-risk 191R allele showed a lower-than-expected level of risk (OR 2.21 vs. the expected 4.76). The data are consistent with the hypothesis that low expression of the antioxidant enzyme PON increases the risk of CHD. Moreover, the promoter polymorphism appears to have a modulating effect on risk that is associated with the coding region polymorphism Q191R. This study indicates a strong genetic component to the antioxidant capacity of HDLs.

Aryldialkylphosphatase↗
PubMed2000

Case complexity and clinical outcome in diabetes mellitus. A prospective study using the INTERMED.

The aim of this study was to assess a population of patients with diabetes mellitus by means of the INTERMED, a classification system for case complexity integrating biological, psychosocial and health care related aspects of disease. The main hypothesis was that the INTERMED would identify distinct clusters of patients with different degrees of case complexity and different clinical outcomes. Patients (n=61) referred to a tertiary reference care centre were evaluated with the INTERMED and followed 9 months for HbA1c values and 6 months for health care utilisation. Cluster analysis revealed two clusters: cluster 1 (62%) consisting of complex patients with high INTERMED scores and cluster 2 (38%) consisting of less complex patients with lower INTERMED. Cluster 1 patients showed significantly higher HbA1c values and a tendency for increased health care utilisation. Total INTERMED scores were significantly related to HbA1c and explained 21% of its variance. In conclusion, different clusters of patients with different degrees of case complexity were identified by the INTERMED, allowing the detection of highly complex patients at risk for poor diabetes control. The INTERMED therefore provides an objective basis for clinical and scientific progress in diabetes mellitus. Ongoing intervention studies will have to confirm these preliminary data and to evaluate if management strategies based on the INTERMED profiles will improve outcomes.

Adult↗
PubMed2000

Mutation screening of the PPARalpha gene in type 2 diabetes associated with coronary heart disease.

The peroxisome proliferator-activated receptor alpha (PPARalpha) is a ligand-activated transcription factor belonging to the nuclear hormone receptor superfamily. PPARalpha plays a key role in lipid and glucose metabolism, inflammatory response and energy homeostasis. The aim of our study was to screen the PPARalpha gene for mutations, and to test the genetic contribution of PPARalpha in diabetes and its vascular complications. The first two non coding exons and the coding region of the PPARalpha gene were screened by single strand conformation polymorphism (SSCP) and sequencing in 74 unrelated Type 2 diabetic patients with history of coronary heart disease (CHD) (18 Caucasian and 56 Indian subjects). A total of 7 nucleotide variants were detected: two single amino acid substitutions, a silent mutation, four intron base changes. Association studies were undertaken in two populations of Type 2 diabetic patients from Pondichery and from France, to test the distribution of allelic frequencies for L162V (exon 5) and A268V (exon 7) polymorphisms. No association was found between these PPARalpha variants and diabetes or CHD. However, in the Caucasian diabetic male population with CHD, the Val162 allele carriers showed higher concentrations of total cholesterol and Apo B when compared to non-carriers (p =0.01 and p =0.005, respectively). A trend toward elevated concentrations of total cholesterol and Apo B was also observed in the Caucasian diabetic male patients without CHD carrying Val162 allele. In conclusion, it is likely that PPARalpha gene does not have a major role in diabetes and CHD in our populations, although we can not exclude a minor contribution of the PPARalpha gene to the risk of CHD associated with Type 2 diabetes through a modulation of atherogenic plasma lipids.

Amino Acid Substitution↗