Biomedical subjects
Publications and source records attributed to F Navarro.
The efficiencies of different tests for epidemiological markers--phage typing, ribotyping, IS200 typing, and pulsed-field gel electrophoresis (PFGE)--were evaluated for strains from sporadic cases of typhoid fever and a well-defined outbreak. Ribotyping and PFGE proved to be the most discriminating. Both detected two different patterns among outbreak-associated strains.
BACKGROUND: The aim of the study was to determine the frequency of third-generation cephalosporins and aztreonam resistance in gram-negative bacteria with inducible chromosomal beta-lactamase (beta Lac-ind) after beta-lactam therapy in the medical-surgical intensive care unit (ICU) at a university-affiliated hospital. PATIENTS AND METHODS: We studied 34 infections in 29 patients admitted to the ICU. All were infected by strains with beta Lac-ind and all were treated with beta-lactam antibiotics. Susceptibility was determined by disc-diffusion. The beta-lactamase activity of those strains showing constitutive beta-lactamase overproduction were characterized by isoelectrofocusing. When this derepression occurred during the therapy, the strains were compared by genomic macrorestriction (PGFE). RESULTS: In 29 out of 34 infections the initial strains was susceptible. In 11 cases, the culture were not negativized in spite of their susceptible pattern. In 4 cases there was derepression during therapy. In 5 cases the initial strains were derepressed. The microorganisms isolated more frequently were Pseudomonas aeruginosa (22 cases) and Enterobacter cloacae (5 cases). The beta-lactamase activity detected correspond well with a betaLac-ind. In those cases with derepression during therapy, the initial susceptible strain and the resistant strain were identical by PGFE.
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PURPOSE: To study the emergence of amoxicilline/clavulanate resistance in Salmonella and Shigella. MATERIAL AND METHODS: We have studied 118 strains of Salmonella enterica and 11 strains of Shigella flexneri isolated in our laboratory along 1993. The MICs values for amoxicilline/clavulanate were determined by the E-Test method and confirmed by the standard agar dilution method. RESULTS: We have observed that 6% (7 out of 118 strains) of Salmonella enterica and 42% (5 out of 11 strains) of Shigella flexneri isolates exhibited an intermediate susceptibility or were resistant to amoxicilline/clavulanate with MICs values ranging between 16 mg/l and 32 mg/l. CONCLUSIONS: Along 1993 we have detected the emergence of an amoxicilline/clavulanate resistance in salmonellae and shigellae strains. To our knowledge this fact has not been published up to now (Medline, 1990-October 1994). We don't know the clinical importance of this fact.
Colonic irrigation (CI) represents the procedure of choice for patients with a colostomy. Recent technical advances (irrigation kit) have provided patients with simple, safe and effective material, allowing a new expansion of this old concept. A total of 795 colostomates (from association's data base) were assessed by questionnaires 386 (49%) of them used CI: 43.5% of patients operated before 1980 and 50% after 1980 (p < 0.005). Two thirds of patients performed Cl every two days, in the morning, with one liter or less of water, for 45 to 60 minutes. No morbidity was reported. Some patients (18%) stopped the procedure deliberately, but none due to a complication. Total continence during 48 H was observed in 48.4% of patients. Wearing a classical stomabag after CI must be considered to be a precaution rather than a failure. However one half of patients wore a simplified material (minibag, obturator, sticking plaster). The vast majority of patients (86%) claimed to be entirely satisfied with CI and 96% wanted to continue the procedure as long as possible.
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The known risk of embolic events in patients with recurrent or chronic atrial fibrillation makes it mandatory to recommend oral anticoagulation in patients with rheumatic mitral valve disease, specially mitral stenosis to maintain an INR between 2.0 and 3.0. If despite this treatment recurrent embolism occurs, the dose of oral anticoagulants should be increased (INR between 2.5 and 3.5) or dipyridamole (200 to 400 mg/day) or aspirin (160 to 320 mg/day) should be added to dicoumarinic drugs. In patients that must be cardioverted either electrically or pharmacologically and who have been on atrial fibrillation for more than 2 days, oral anticoagulation should be maintained for 3-4 weeks before cardioversion and for 3-4 weeks after regaining sinus rhythm. Transesophageal echocardiography may enable us to identify the group of patients with low risk for an immediate cardioversion. In patients under 60 years of age with atrial fibrillation and no evidence of associated cardiovascular abnormality (lone atrial fibrillation) the embolic risk is very low and antithrombotic therapy is probably not needed. In subjects over 60 years of age with a low risk profile (absence of previous stroke, heart failure or systemic hypertension) aspirin (300-325 mg a day) seems to offer sufficient protection against embolic events. In patients at a higher embolic risk (history of previous cerebral ischemic attacks, heart failure of left ventricular dysfunction, systemic hypertension) oral anticoagulation unless contraindicated, should be recommended (INR 2.0-3.0). The role of other antithrombotic agents such as ticlopidine or triflusal to prevent embolic events in patients with atrial fibrillation is unknown.
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With the decreasing mortality and morbidity of liver resection in the last 10 years, a more aggressive approach has emerged against liver metastases of colorectal cancer. Repeat liver resection is being performed for patients with isolated liver recurrence following a first hepatectomy. Based on a 2-year experience of 55 repeat hepatic resections performed in 44 patients, the authors observed no operative mortality and a postoperative morbidity of 15% similar to that of first hepatectomies. Five-year survival rate is 44% following second hepatectomy. These results combined with the review of the literature demonstrate that rehapectomy may be performed safely and may provide the only chance of long-term remission in patients presenting with technically resectable liver recurrence in the absence of widespread extrahepatic disease.
The purpose of this study was to assess the accuracy of guided hepatic biopsy (GHB) and imaging techniques for presumed benign liver tumours and to determine their impact on surgical treatment. The study was carried out retrospectively in a surgical series of 15 consecutive patients with presumed benign liver tumours. The final diagnosis was 8 cases of focal nodular hyperplasia (FNH), 6 hepatic adenomas (HA) and one association FNH-HA. No morbidity was related to guided hepatic biopsy. All FNH detected on radiologic imaging or pathological examination of the biopsy specimen were true positive diagnoses. This study demonstrates that combined results of imaging techniques and percutaneous GHB could correctly diagnose three quarters of FNH before surgery. GHB is also useful when MRI imaging is indeterminate allowing a conservative approach for undiagnosed FNH.
BACKGROUND: The aim of the study was to evaluate the chromogenic agar plate CPS ID2 (bioMérieux) and determine its cost-benefit ratio. METHODS: A total of 2,193 urinary sediments were processed. The urine culture was carried out in CPS ID2 agar and in cystine-lactose electrolyte deficient (CLED) agar, when needed. Identification of the microorganisms was performed following standard microbiologic procedures through biochemical tests prepared in our laboratory. The identification, from CPS ID2 agar, by direct detection in medium of four metabolic activities: beta-glucuronidase, beta-glucosidase, deaminase, and indol production, was performed following to manufacturer's instructions. RESULTS: A total of 289 urine cultures were positive, 18 were negative and 34 were contaminated samples. The identification, directly performed from the colonies detected in CPS ID2 agar, was correct in 96% of 166 Escherichia coli, in 92% of 24 Proteus mirabilis and in 97% of 38 enterococci. CPS ID2 agar exhibited 94% and 100% sensitivity and specificity, respectively in E. coli identification, 92% and 100% in P. mirabilis and 97% and 99% in Enterococcus. The use of this new media, CPS ID2, in our laboratory, implies a budgetary increment. However, if commercial galleries are used for routine identification, the cost will be reduced using this new media. CONCLUSIONS: The CPS ID2 agar allows the isolation and direct identification of the most frequent urinary tract pathogens: E. coli, P. mirabilis and Enterococcus in primary isolation medium. Using this medium, bacteriologists will be able to save time and reagents when identifying the most common uropathogens. Furthermore, the use of this medium would reduce costs in some laboratories.
INTRODUCTION AND OBJECTIVES: Refractory angina, specially when accompanied by electrocardiographic (ECGs) changes, has been associated with a high morbidity and mortality if urgent revascularization is not performed. Percutaneous Transluminal Coronary Angioplasty (PTCA) could be a useful therapeutic alternative in such cases. The aim of this study was to compare the immediate and midterm outcomes of a cohort of high risk patients with refractory angina with or without ECG changes revascularized by PTCA. METHODS: Of 801 consecutive patients who underwent PTCA, we selected 48 patients (49 procedures, 61 lesions), with unstable angina in spite of treatment with nitroglycerin, calcium channel blockers, beta blockers, heparin and aspirin (refractory angina). Twenty-six patients (27 procedures, 37 lesions) had ECG changes (group A), and 22 patients (22 PTCAs, 24 lesions) did not have changes (group B). RESULTS: Mean age of patients was 65 +/- 11 years. The most frequent ECG changes found in group A were T wave inversion (38%) and ST segment depression (34%). The left anterior descending coronary artery was the most frequent dilated vessel (41%). Some new devices (Stent, Rotablator, etc.) were used in 22% vs 25% of lesions in group A and B respectively. Successful dilatation was achieved in 59 (96%) of attempted lesion without statistical differences between group A and B. One patient in each group developed an acute myocardial infarction. Death occurred in 2 patients from group A (one of non-cardiovascular cause). Follow-up was obtained in 33 (94%) of the 35 patients (minimum follow-up > or = 6 months or less if a major event occurred). Mean follow-up time was 16.7 +/- 6 vs 13.4 +/- 6 months in group A and B. During this time, death occurred in 2 patients (6%) both from group B (one non-cardiac); in 9 (27%) patients a repeat PTCA was performed (26% of patients from group A and 28% from B); CABG was performed in 2 (6%) patients (both from group B), and an AMI occurred in 1 patient in each group. Angiographic follow-up was obtained in 73% of patients in group A vs 91% in group B. The restenosis rate was 47% in group A vs 54% in group B. At the end of the first year of follow-up, 93% of patients were alive and 9/10 patients successfully revascularized were asymptomatic or had less severe angina. CONCLUSIONS: At present, PTCA is a safe revascularization method in patients with refractory angina providing a high initial success (95% of cases) and a good mid-term outcome (one year): > 90% survival rate, with improvement in the quality of life in 9/10 patients successfully revascularized, regardless of the presence or absence of ECG changes at the time of PTCA.
A 34 kDa coenzyme Q reductase has been solubilized and purified from pig liver plasma membranes. The solubilized enzyme reduced coenzyme Q0 with NADH. Ubiquinones with longer isoprenoid side chain such as Q2 and Q10 were also reduced when the quinones and the enzyme were reconstituted into phospholipid liposomes. N-terminal sequencing of an internal peptide showed identity to bovine NADH-cytochrome b5 reductase. Biochemical characterization of the purified enzyme indicated that the coenzyme Q reductase corresponds to an unusual form of NADH-cytochrome b5 reductase.
A specific requirement for coenzyme Q in the maintenance of trans-plasma-membrane redox activity is demonstrated. Extraction of coenzyme Q from membranes resulted in inhibition of NADH-ascorbate free radical reductase (trans electron transport), and addition of coenzyme Q10 restored the activity. NADH-cytochrome c oxidoreductase (cis electron transport) did not respond to the coenzyme Q status. Quinone analogs inhibited trans-plasma-membrane redox activity, and the inhibition was reversed by coenzyme Q. A 34-kDa coenzyme Q reductase (p34) has been purified from pig-liver plasma membranes. The isolated enzyme was sensitive to quinone-site inhibitors. p34 catalyzed the NADH-dependent reduction of coenzyme Q10 after reconstitution in phospholipid liposomes. When plasma membranes were supplemented with extra p34, NADH-ascorbate free radical reductase was activated but NADH-cytochrome c oxidoreductase was not. These results support the involvement of p34 as a source of electrons for the trans-plasma-membrane redox system oxidizing NADH and support coenzyme Q as an intermediate electron carrier between NADH and the external acceptor ascorbate free radical.
The first two genes of ferredoxin-dependent glutamate synthase (Fd-GOGAT) from a prokaryotic organism, the cyanobacterium Synechocystis sp. PCC 6803, were cloned in Escherichia coli. Partial sequencing of the cloned genomic DNA, of the 6.3 kb Hind III and 9.3 kb Cla I fragments, confirmed the existence of two different genes coding for glutamate synthases, named gltB and gltS. The gltB gene was completely sequenced and encodes for a polypeptide of 1550 amino acid residues (M(r) 168,964). Comparative analysis of the gltB deduced amino acid sequence against other glutamate synthases shows a higher identity with the alfalfa NADH-GOGAT (55.2%) than with the corresponding Fd-GOGAT from the higher plants maize and spinach (about 43%), the red alga Antithamnion sp. (42%) or with the NADPH-GOGAT of bacterial source, such as Escherichia coli (41%) and Azospirillum brasilense (45%). The detailed analysis of Synechocystis gltB deduced amino acid sequence shows strongly conserved regions that have been assigned to the 3Fe-4S cluster (CX5CHX3C), the FMN-binding domain and the glutamine-amide transferase domain. Insertional inactivation of gltB and gltS genes revealed that both genes code for ferredoxin-dependent glutamate synthases which were nonessential for Synechocystis growth, as shown by the ferredoxin-dependent glutamate synthase activity and western-blot analysis of the mutant strains.
Quantification and localization of the main lymphocyte populations were studied in the livers of normal (n = 8) and brain dead (n = 8) subjects. Cytometric analysis performed on mononuclear cell suspensions obtained from liver biopsies was compared to an automatic image analysis of immunostained sections. The overall number of liver associated lymphocytes was in the usual range of peripheral blood content (2 to 9x10(9) cells). Phenotypic analysis showed predominant NK and CD8+ cells that highly expressed class II antigen and CD25 and CD69 activation markers. Quantitative mapping of these activated lymphocytes revealed their preferential localization in the portal tract and the perisinusoidal area as compared to the pericentrolobular zone, especially in donor livers. This strategic localization could suggest a possible early cooperation between donor lymphocytes and initial infiltrating cells from the recipient and could explain the special immunological status of allografted livers.
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