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J Ruiz

Publications and source records attributed to J Ruiz.

At least 145 records · Page 8Linked to original sources
PubMed1999

Analysis of the mechanisms of quinolone resistance in clinical isolates of Citrobacter freundii.

The presence of gyrA, gyrB and/or parC mutations, quinolone uptake, outer membrane protein profiles and epidemiological relationship were studied in 12 clinical isolates of Citrobacter freundii. No alterations were observed in the gyrB gene of any of the strains, or gyrA or parC of the four quinolone-susceptible strains (nalidixic acid MIC of 2-4 mg/L, and a ciprofloxacin MIC of 0.006-0.06 mg/L). The quinolone-resistant strains were classified into two groups: one group (group A) composed of strains resistant to nalidixic acid but not to ciprofloxacin and another (group B) including those resistant to both antibiotics with a mutation at codon 83 of the gyrA gene (Thr-->Ile), but no alteration in either parC or gyrB genes. In group B, three of the four resistant isolates, with a nalidixic acid MIC > 1024 mg/L and ciprofloxacin MIC of 8-32 mg/L, showed concomitant mutations at codons 83 and 87 of the gyrA gene (Thr-->Ile and Asp-->Tyr, respectively) as well as a single mutation in codon 80 of the parC gene (Ser-->Ile). The fourth isolate did not possess the mutation at codon 87 of gyrA. Two strains belong to the same clone and, although they had the same type of mutations in the gyrA and parC genes, showed different MICs of ciprofloxacin. This difference was related to an efflux pump mechanism. Mutations in the gyrA and parC genes play the main role in quinolone resistance development in Citrobacter freundii, although other factors such as overexpression of efflux pumps can play a complementary role and thus modulate the final quinolone MIC.

Amino Acid Sequence↗
PubMed1999

Increase in incidence of resistance to ampicillin, chloramphenicol and trimethoprim in clinical isolates of Salmonella serotype Typhimurium with investigation of molecular epidemiology and mechanisms of resistance.

Antimicrobial resistance patterns of Salmonella serotype Typhimurium isolates obtained during the period 1987-1994 were examined and the molecular epidemiology and the mechanisms of resistance to ampicillin, chloramphenicol and trimethoprim were investigated in 24 strains isolated during 1994. Resistance to ampicillin increased from 18% to 78%, to chloramphenicol from 15% to 78%, to tetracycline from 53% to 89% and to co-trimoxazole from 3% to 37%, whereas resistance to norfloxacin remained at 0%. Of Salmonella serotype Typhimurium strains isolated during 1994, all ampicillin-resistant strains had an MIC > 256 mg/L, except one strain in which the MIC was 64 mg/L. Twelve strains (52%) had a TEM-type beta-lactamase, nine (39%) a CARB-type beta-lactamase and two strains (8%) had an OXA-type beta-lactamase. Chloramphenicol acetyl-transferase activity was detected in only nine (47%) of 19 chloramphenicol resistant strains, whereas all eight trimethoprim-resistant strains produced a dihydrofolate reductase type Ia enzyme. Three different epidemiological groups were defined by either low-frequency restriction analysis of chromosomal DNA and pulsed-field gel electrophoresis or repetitive extragenic palindromic-PCR. The latter technique provided an alternative, rapid and powerful genotyping method for S. Typhimurium. Although quinolones provide a good therapeutic alternative, the multiresistance of S. Typhimurium is of public health concern and it is important to continue surveillance of resistance levels and their mechanisms.

Ampicillin Resistance↗
PubMed1999

Increase in quinolone resistance in a Haemophilus influenzae strain isolated from a patient with recurrent respiratory infections treated with ofloxacin.

The increase in the level of quinolone resistance of Haemophilus influenzae clinical isolates during ofloxacin therapy of a patient with recurrent respiratory infections was investigated. The first isolate (MIC of ciprofloxacin of 2 microg/ml) and the second isolate (MIC of 32 microg/ml) belonged to the same clone, as shown by pulsed-field gel electrophoresis, and the increase in the resistance level was associated with a substitution in Ser-84 to Arg in the ParC protein. These results emphasize the potential risk of development of quinolone-resistant H. influenzae during fluoroquinolone therapy in patients with recurrent respiratory infection.

Amino Acid Substitution↗
PubMed1999

Typing and characterization of mechanisms of resistance of Shigella spp. isolated from feces of children under 5 years of age from Ifakara, Tanzania.

Eighty-six strains of Shigella spp. were isolated during the dry season from stool samples of children under 5 years of age in Ifakara, Tanzania. The epidemiological relationship as well as the antimicrobial susceptibility and mechanisms of resistance to ampicillin, chloramphenicol, and co-trimoxazole were investigated. Four different epidemiological tools, pulsed-field gel electrophoresis (PFGE), repetitive extragenic palindromic (REP)-PCR, plasmid analysis, and antibiogram, were compared for typing Shigella strains. Seventy-eight (90%) strains were Shigella flexneri and were distributed into four groups, by either PFGE or REP-PCR, with 51, 17, 7, and 3 strains. The four strains of Shigella dysenteriae belonged to the same group, and the four strains of Shigella sonnei were distributed in two groups with three and one strain each. Plasmid analysis showed a high level of heterogeneity among strains belonging to the same PFGE group, while the antibiogram was less discriminative. REP-PCR provided an alternative, rapid, powerful genotyping method for Shigella spp. Overall, antimicrobial susceptibility testing showed a high level of resistance to ampicillin (81.8%), chloramphenicol (72.7%), tetracycline (96.9%), and co-trimoxazole (87.9%). Ampicillin resistance was related to an integron-borne OXA-1-type beta-lactamase in 85.1% of the cases and to a TEM-1-type beta-lactamase in the remaining 14.8%. Resistance to co-trimoxazole was due to the presence of a dhfr Ia gene in all groups except one of S. flexneri, where a dhfr VII gene was found within an integron. Chloramphenicol resistance was associated in every case with positive chloramphenicol acetyltransferase activity. All strains were susceptible to nalidixic acid, ciprofloxacin, ceftazidime, cefotaxime, and cefoxitin. Therefore, these antimicrobial agents may be good alternatives for the treatment of diarrhea caused by Shigella in Tanzania.

Bacterial Typing Techniques↗
PubMed1999

Spread of amikacin resistance in Acinetobacter baumannii strains isolated in Spain due to an epidemic strain.

Sixteen amikacin-resistant clinical Acinetobacter baumannii isolates from nine different hospitals in Spain were investigated to determine whether the high incidence of amikacin-resistant A. baumannii was due to the dissemination of an amikacin-resistant strain or to the spread of an amikacin resistance gene. The epidemiological relationship studied by repetitive extragenic palindromic PCR and low-frequency restriction analysis of chromosomal DNA showed that the same clone was isolated in eight of nine hospitals, although other clones were also found. The strains were studied for the presence of the aph(3')-VIa and aac(6')-I genes, which encode enzymes which inactivate amikacin, by PCR. All 16 clinical isolates had positive PCRs with primers specific for the amplification of the aph(3')-VIa gene, whereas none had a positive reaction for the amplification of the aac(6')-I gene. Therefore, the high incidence of amikacin resistance among clinical A. baumannii isolates in Spain was mainly due to an epidemic strain, although the spread of the aph(3')-VI gene cannot be ruled out.

Acinetobacter↗
PubMed1999

Report of an image quality and dose audit according to directive 97/43/Euratom at Spanish private radiodiagnostics facilities.

An audit of Spanish private medicine radiodiagnostics facilities has been carried out, based partly on Spanish legislation relating to European Directives on health protection against ionizing radiation risks in medical exposure. The study included an appraisal of infrastructure and equipment, and aspects of quality assurance and radiation protection, by means of data collected through surveys. Of the 51 centres audited, a sample of 24 X-ray rooms was chosen, then an external evaluation with regard to image quality and patient dose was performed, by an advisory board of radiologists and medical physicists. The methodology used was similar to that of the group of European Union experts in European dose evaluation and image quality trials. Chest, abdomen, lumbar spine and breast examinations were monitored. Doses were measured with thermoluminescent dosimeters. A third of the X-ray rooms evaluated reached or exceeded dose reference values, and in a third of the cases the image quality left considerable room for improvement. Breast and chest examinations showed themselves to be the hardest to perform, not only as a result of exceeding the reference doses, but also due to failure to meet good image quality standards.

European Union↗
PubMed1999

[Partial Currarino syndrome in a non-pediatric patient. A rare cause of bacterial meningitis].

Enterogenic meningitis is an infrequent cause of central nervous system infection. Among these causes the Currarino syndrome may be found presenting sacral agenesis, presacral mass and anorectal stenosis. This syndrome normally causes enterogenic meningitis in the early years of life. The case reported corresponds to a 24-year-old male presenting polymicrobial meningitis with fecal flora germs (anerobic enterococci, Bacteroides fragilis and Escherichia coli). These clinical findings led to radiologic lumbar study with the diagnosis of Currarino syndrome. The existence of neuroenteric fistulas justifies the development of fecal flora meningitis. The nosology of the syndrome as well as the therapeutic strategy are reviewed.

Adult↗
PubMed1998

[The impact of bronchial colonization in the quality of life of patients with chronic, stable bronchitis].

BACKGROUND: The aim of this study was to determine the impact of respiratory function and bacterial colonization of the lower airway on the quality of life of patients with chronic, stable bronchitis (CB). MATERIALS AND METHODS: A series of 41 patients with stable CB was studied (age: 63.8; standard deviation (SD) 9.1 years; FVC% 91.0 (18.9); FEV1% 74.6 (23.7); FEV1/FEC 62.8 (11.2) with normal thoracic radiography. Patients with previous diagnosis of bronchiectasia, bronchial asthma and/or positive bronchodilatory tests (> 15%) were not included in the study. Bacterial growth in a sputum sample of grade 4-5 of the Murray-Washington scale was considered diagnostic of bronchial colonization. Measurement of the quality of life was performed with the Nottingham Health Profile (NHP) and the St. George Respiratory Questionnaire (SGRQ). RESULTS: The patients presented a moderate alteration in their quality of life with scores over 25 in most of the dimensions of the NHP and the SGRQ. In 9 out of 41 cases (22%), the sputum cultures demonstrated bronchial colonization with the most frequently isolated bacterias being Haemophilus influenzae and Moraxella catarrhalis. Multivariate analysis performed with the quality of life as the dependent variable showed an association between FEV1/FEC1 and the SGRQ score (R2 = 0.18), and energy (R2 = 0.09) and physical mobility (R2 = 0.05) of NHP. CONCLUSIONS: Bronchial obstruction is the main determinant in the quality of life in patients with stable CB. Colonization of the lower airway is observed in 22% of the patients and also influences the quality of life of the patients but to a much lesser extent.

Aged↗
PubMed1998

[Secondary prevention of ischemic heart disease after coronary revascularization].

This study was aimed to assess the compliance with policies for secondary prevention of coronary heart disease (CHD) one year after coronary artery revascularization with special attention to the management of hyperlipidemia. One year after coronary revascularization during the year 1994, patients were contacted by letter to determine the modification of their risk factors, the treatment patterns for hypercholesterolemia and to have their plasma lipid level and blood pressure measured. Of the 245 consecutive patients contacted (110 after coronary artery bypass grafting, and 135 after percutaneous transluminal coronary angioplasty), 186 (76%) provided the information required for further analysis. Excluding the patients older than 65 years, only 29 out of 97 patients (30%) with a total cholesterol of more than 5.2 mmol/l, and only 20 out of 52 patients (38%) with a total cholesterol of more than 6.2 mmol/l were receiving lipid lowering therapy 1 year after coronary artery revascularization. In contrast, 97% (n = 180) of the entire population studied were taking antiplatelet drugs and/or coumadine. Participation in an in-house rehabilitation program yielded a positive influence on smoking, but not on treatment of hypercholesterolemia. In conclusion, only a small proportion of patients with documented CHD and hypercholesterolemia were being treated for their lipid disorder 1 year after coronary artery revascularization. In contrast, the great majority of patients received antiplatelet and/or coumadine therapy: These results indicate that the compliance with published treatment guidelines for hyperlipidemia in patients with CHD is still highly inadequate, irrespective of the participation in a rehabilitation program.

Aged↗
PubMed1998

Rapidly deteriorating polyneuropathy associated with osteosclerotic myeloma responsive to intravenous immunoglobulin and radiotherapy.

Osteosclerotic myeloma is a plasma-cell dyscrasia characterized by osteosclerotic bone lesions, which may be associated with progressive demyelinating polyneuropathy. We describe a 49-year-old patient with rapidly deteriorating polyneuropathy associated with osteosclerotic myeloma, who responded favorably to a combination of intravenous immunoglobulin and radiotherapy.

Combined Modality Therapy↗
PubMed1998

Early complete recanalization in internal carotid artery embolism treated with high-dose t-PA: a sequential angiographic study in a novel model of embolism in rats.

Complete early recanalization rate of human internal carotid artery embolic occlusion treated with thrombolytic drugs is low. To study factors related with this difficulty to recanalize we have developed a novel model of rat ica embolism using a fragment of human embolus. In 50 male Wistar rats the ica was embolized through the external carotid artery with a fragment of an embolus obtained from a human embolectomy passed through a catheter of 0.8 mm diameter. Recanalization was assessed by sequential angiograms from 15 to 120 min after embolization. Reperfusion was classified according to TIMI grades. Emboli of either 1 (group 1) or 2 mm (group 2) in length were cut. In group 1, four groups of nine animals each were treated, 15 min after embolization, with i.v. t-PA at doses of 1 mg/kg, 10 mg/kg and 20 mg/kg or saline. In group 2 there was one control group of seven animals treated with saline and another of seven animals treated with 10 mg/kg t-PA. Complete recanalization (TIMI grade 3) within the first 30 min was present in two animals treated with 10 and 20 mg/kg. Complete recanalization within the first 60 min was present in 0% of controls and animals treated with 1 mg/kg and in 44% of the 10 and 20 mg/kg groups (P<0.05 in chi-square test). Incomplete recanalization (TIMI grades 0, 1 and 2) occurred in 33%. In group 2 total recanalization occurred in 1/7 controls and in 3/7 animals receiving 10 mg/kg of t-PA. Early (60 min) complete i.v. t-PA induced internal carotid artery embolic recanalization is low with standard doses and increases moderately when high doses are used. Further increases in the dose do not improve recanalization rate, which is not clearly influenced by embolus size. Complete recanalization within 30 min, the period after which infarction develops in the rat, is uncommon in our model.

Angiography↗
PubMed1998

[Evolution of the prevalence of hepatitis A antibody in Seville].

OBJECTIVE: To find the evolution of the prevalence of the Hepatitis-A antibody in Sevilla. DESIGN: Observational study of a crossover type. Comparison of results in 1995 with those from a similar study in 1981. SETTING: Health Area covered by Sevilla's University Hospital Virgen del Rocío. PATIENTS AND OTHER PARTICIPANTS: Aliquots of serum from patients without Hepatitis were obtained from the hospital's clinical analysis laboratories. MEASUREMENTS AND MAIN RESULTS: The sera were analysed in the Nuclear Medicine laboratory of the HUVR. 37.96% (62.74% in 1981) of the individuals surveyed were HA-positive. Prevalence increased with age: in the over-24s it was over 75% (90% in 1981). The differences between the two sets of results was significant (p < 0.001). CONCLUSIONS: Hepatitis-A infection is becoming less common in Andalusia, which can now be considered a low-incidence area.

Adolescent↗
PubMed1998

Relation of smoking to breast cancer by estrogen receptor status.

It has been suggested that smoking is associated with estrogen-negative breast cancer but not with estrogen-positive breast cancer. A population-based case-control study was conducted in Geneva, Switzerland, to determine the relation of passive and active smoking to breast cancer when the referent unexposed category consisted of women unexposed to active and passive smoke. The 242 patients with breast cancer (cases), in whom estrogen receptor (ER) status was determined on biopsy material, were compared with 1,059 women free of breast cancer (controls). Lifetime history of active and passive smoking was recorded year by year, between age 10 and the date of interview. Prevalence rates of ER+ tumors were 74.7% in pre-menopausal women and 74.2% in post-menopausal women. Post-menopausal active smokers had a lower prevalence of ER+ tumors (70.0%, p = ns). Among pre-menopausal women, the age-adjusted ORs of breast cancer with having smoked an average of > or = 20 cigarettes per day (cpd) during lifetime were 2.7 for ER- tumors and 2.6 for ER+ tumors. Among post-menopausal women, corresponding ORs were 5.7 for ER- tumors and 2.4 for ER+ tumors. Smoking was related to both ER- and ER+ breast cancer in pre- and post-menopausal women, but the strength of the association appeared to be greater for ER- tumors among post-menopausal women.

Aged↗
PubMed1998

Prototype Internet consultation system for radiologists.

The overall purpose of this study is to develop a prototype radiological consultation system. We concentrate our work on prototype software environment for the system. The system provides a second diagnostic opinion based on similar cases, incorporating the experience of radiologists, their diagnostic rules and a database of previous cases. The system allows a radiologist to enter the description of a particular case using the lexicon such as BI-RADS of American College of Radiology and retrieve the second diagnostic opinion (probable diagnosis) for a given case. The system also allows a radiologist to get other important information too. These advances are based on a new computational intelligence technique and first-order logic. We implemented a rule-based prototype diagnostic system. Two experimental Internet versions are currently available on the web and are under testing and evaluation of design. The diagnosis is based on the opinions of radiologists in combination with the statistically significant diagnostic rules extracted from the available database.

Breast Diseases↗
PubMed1998

Diabetes mellitus and vascular lesions.

Cardiovascular complications represent by far the most severe manifestations of diabetes mellitus. Treatment aimed at stopping progression of vascular lesions may fall short if initiated when the disease becomes clinically evident. Therefore, identification of the earliest vascular disfunctions may offer the best opportunity to interfere with pathogenic mechanisms and avoid progression of diabetic vasculopathy. In this report, we present a few mechanisms that alter hemodynamic and metabolic homeostasis in the course of diabetes mellitus. Endothelial function with special emphasis on nitric oxide and oxidative stress, advanced glycation end products, and the renin angiotensin system are briefly discussed. New pharmacological agents that may favorably influence these parameters are presently undergoing clinical trials. However, tight control of plasma glucose and cardiovascular risk factors represent the cornerstone of the treatment in diabetes to slow progression of vascular disease.

Animals↗