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Biomedical subjects

R Aznar

Publications and source records attributed to R Aznar.

At least 37 records · Page 2Linked to original sources
PubMed1991

Antibiotic prophylaxis in non-cardiac thoracic surgery: cefazolin versus placebo.

A total of 127 patients (57 given placebo and 70 given a single preoperative dose of 1 g cefazolin) undergoing thoracic surgery were included in a randomized double-blind trial. The two groups were similar in regard to mean age, sex ratio, in-hospital stay before surgery, underlying disease, risk factors, type of surgery, mean duration of surgical procedure, and mean duration of chest tube drainage. The relative risk of wound infection of the patients from the placebo group was 3.27 (range 1.5-11.5; 95% confidence interval). Cefazolin significantly reduced (p less than 0.01) the wound infection rate--1 case (1.5%) in the cefazolin group versus 8 cases (14%) in the placebo group--but not the incidence of postoperative pleural empyema--5 (7%) versus 8 cases (14%)--or nosocomial pneumonia--3 (4%) versus 5 cases (9%). Cultures were made from 3 out of 9 wound infections and Staphylococcus aureus or S. epidermidis was isolated in all 3. In addition, cultures were made from 6 out of 13 pleural cavity infections and S. aureus (1 case) or other microorganisms (5 cases) were isolated in all 6. Mortality was similar in both groups and all deaths unrelated to the infections. No adverse side effects of the drug were encountered. In conclusion, a single preoperative dose of 1 g cefazolin proved to be effective for reducing the wound infection rate in non-cardiac thoracic surgery.

Adult↗
PubMed1991

Physico-chemical and bacteriological parameters in a hypereutrophic lagoon (Albufera Lake, Valencia, Spain).

Several physico-chemical parameters related to water quality, as well as saprophytic and public health-related heterotrophic bacterial groups were studied in a hypereutrophic lake (Albufera, Valencia) at different seasons. Total microscopic and viable counts were compared, and, together with faecal indicators, were determined in water samples from different sites. Heterotrophic bacteria grown on nonselective medium were identified to genus level and a diversity index was calculated. Pseudomonas-Alcaligenes was the most frequently isolated group from all sampling sites along the study, following by Moraxella, Acinetobacter, Vibrio and Aeromonas. The relationships between all parameters were searched by Principal Components Analysis (PCA).

Bacteria↗
PubMed1990

Surface and virulence properties of environmental Vibrio cholerae non-O1 from Albufera Lake (Valencia, Spain).

A total of 140 environmental Vibrio cholerae non-O1 isolates, together with several culture collection strains from both environmental and clinical sources, were studied in relation to hemagglutination, surface hydrophobicity, and the enzymatic, hemolytic, cytotoxic, and enterotoxic activities of their extracellular products. A total of 78 and 62% of the strains produced hemagglutinins and exohemagglutinins, respectively. Four different hemagglutinating and two exohemagglutinating activities were found by using eight sugars in the inhibition assays. Cell-bound mannose-sensitive hemagglutination was detected mainly in chicken blood, whereas fucose-sensitive hemagglutination was recorded only in human blood. Cell-bound hemagglutinin resistant to all sugars tested was the only one related to surface hydrophobicity. The surface properties varied along the growth curves. The non-O1 strains displayed strong enzymatic and hemolytic activities, except for esculin hydrolysis. Of 26 non-O1 isolates selected for cytotoxin and enterotoxin production, 23 showed a wide spectrum of cytotoxic effects on cell lines of poikilothermic and homoiothermic species, but they were weakly enterotoxigenic in the infant mouse test. All extracellular products of cytotoxic strains were proteolytic, lipolytic, and hemolytic, and a high percentage produced hemagglutination of chicken blood. The cytotoxic factors in the non-O1 strains analyzed were not R plasmid mediated.

Antigens, Bacterial↗
PubMed1990

Iron-binding compounds and related outer membrane proteins in Vibrio cholerae non-O1 strains from aquatic environments.

A total of 156 strains of Vibrio cholerae non-O1 from aquatic origins were examined for the presence of iron uptake mechanisms and compared with O1 strains and other Vibrio species. All non-O1 strains were able to grow in iron-limiting conditions, with MICs of ethylenediaminedi (O-hydroxyphenylacetic acid) ranging from 20 microM to 2 mM. The production of siderophores was demonstrated by growth in chrome azurol S agar and cross-feeding assays. All strains produced phenolate-type compounds, as assessed by the chemical tests and by bioassays with Salmonella typhimurium enb-7. Some of the strains also promoted the growth of S. typhimurium enb-1 (which can use only enterobactin as a siderophore) as well as some strains of Vibrio anguillarum deficient in the anguibactin-mediated system. The chromatographic analyses and absorption spectra of siderophores extracted from culture supernatants suggest that vibriobactin may be produced by the strains examined. Interestingly, some strains also produced hydroxamate-type compounds, as determined by chemical tests, and were able to promote the growth of an aerobactin-deficient strain of Escherichia coli. These results were confirmed by the absorption spectra and chromatographic analyses of the culture extracts. The synthesis of iron-regulated outer membrane proteins in representative strains was also examined. The molecular sizes of the main induced proteins ranged from 70 to 78 kilodaltons. These results indicate that several iron uptake mechanisms which could be involved in environmental survival and pathogenicity are present in environmental V. cholerae non-O1 strains.

Bacterial Outer Membrane Proteins↗
PubMed1990

Incidence, risk, and prognosis factors of nosocomial pneumonia in mechanically ventilated patients.

Seventy-eight (24%) episodes of nosocomial pneumonia (NP) were detected in 322 consecutive mechanically ventilated patients admitted to a 1,000-bed teaching hospital from April 1987 through May 1988 to assess the incidence, risk, and prognosis factors of NP acquired during mechanical ventilation (MV). The risk and prognosis factors for developing NP during MV were studied using both univariate and multivariate statistical techniques. Multivariate analysis selected the following variables significantly associated with a higher risk for developing ventilator-associated pneumonia: more than one intubation during MV (p = 0.000012), a prior episode of aspiration of gastric content (p = 0.00018), a MV period longer than 3 days (p = 0.015), the presence of chronic obstructive pulmonary disease (COPD) (p = 0.048), and the use of positive end-expiratory pressure (PEEP) during MV (p = 0.092). The presence of an ultimately or rapidly fatal underlying disease (p = 0.0018), worsening of acute respiratory failure caused by pneumonia (p = 0.0096), the presence of septic shock (p = 0.016), an inappropriate antibiotic treatment (p = 0.02), and the type of intensive care unit (ICU) hospitalization (noncardiac surgery and nonsurgical ICU compared with post-cardiac surgery ICU) (p = 0.08) were those factors selected by a stepwise logistic regression analysis as independently worsening the prognosis. The overall fatality rate was 23% (73 of 322). The mortality of patients with NP was higher (33%; 26 of 78; p less than 0.01) when compared with fatality rates of patients without NP (19%; 47 of 244).(ABSTRACT TRUNCATED AT 250 WORDS)

Cross Infection↗
PubMed1990

[The superior vena cava syndrome secondary to a benign intrathoracic goiter: a case report and review of the literature].

The clinical case of a female patient suffering a benign retrosternal goitre which first appeared as a superior vena cava syndrome, is presented. After confirming the diagnosis with an intrathoracic CT scan, a subtotal bilateral thyroidectomy was performed resulting in a complete remission of the clinical picture. A literature review is performed commenting on some clinical, diagnostic and therapeutical aspects.

Aged↗
PubMed1989

[Infective endocarditis caused by coagulase-negative staphylococci: a review of 19 cases].

The clinical, microbiological and echocardiographical features as well as the response to therapy of 19 cases of infective endocarditis (IE) caused by coagulase-negative staphylococci (CNS) are reported. Six patients had native valve IE, 11 had prosthetic valve endocarditis and 2 were associated with catheters in right cardiac chambers. In the group of native valve IE, 11 patients were heroin abusers and 4 had previous valvular disease. IE was left sided in 3 cases, mixed in 2 and right sided in 1. All CNS were methicillin-sensitive. The echocardiogram detected vegetations in 5 of the 6 cases. One patient required surgery and another died. In the group of prosthetic valve IE, 5 patients had early endocarditis and 6 had late endocarditis. A bioprosthesis was involved in 5 cases, a mechanical prosthesis in another 5, and an annuloplasty annulus in one. The involved prosthesis was aortic in 5 cases and mitral in 6. The echocardiogram detected vegetations in 3 cases (27%) and prosthetic dysfunction in 4. One patient had a relapse, 8 (73%) required valve replacement and 3 died. Although the greatest incidence of IE caused by CNS is found among patients with prosthetic valves, it can also be seen in patients with underlying valvular heart disease, drug abusers and patients with indwelling catheters in right cardiac chambers.

Adult↗
PubMed1989

Siderophore production by environmental strains of Salmonella species.

Iron uptake mechanisms were investigated in different species of Salmonella isolated from environmental waters. All strains examined were able to grow in the presence of high concentrations (10 mM) of the iron chelator EDDA. All strains excreted phenolate and hydroxamate siderophores, as assessed by bioassays and chemical tests. Bioassays with different indicator strains showed that all Salmonella strains can cross-feed other Enterobacteria, as well as mutants of Salmonella typhimurium deficient in the Enterobactin system, suggesting that this siderophore may be produced by the environmental Salmonella strains. The siderophore aerobactin may also be produced by one of the strains, according to the bioassays results. The same pattern of outer membrane proteins are synthesized under iron-limiting conditions in all species tested, which suggests a similarity of iron uptake systems in many species of Salmonella. This system could be also of great importance in the survival of these bacteria in natural waters, as well as in possible pathogenic mechanisms.

Bacterial Outer Membrane Proteins↗
PubMed1989

Incidence and etiology of pneumonia acquired during mechanical ventilation.

A total of 77 consecutive patients submitted to mechanical ventilation (MV) for greater than 48 h in a respiratory ICU (RICU) were studied to investigate the incidence, etiology, and consequences of ventilator-associated pneumonia. Eighteen (23%) patients developed a bacterial pneumonia after 5.6 +/- 1.0 days (mean +/- SEM; range 2 to 17) of MV. Three additional cases were demonstrated at autopsy, raising the incidence to 27%. Overall, the mean duration of MV increased from 9.7 +/- 0.9 to 32.2 +/- 5.1 days (p less than .0001) when pneumonia developed. A longer period of hospital stay before RICU admission and the presence of chronic obstructive pulmonary disease were significant characteristics of patients with pneumonia when compared to patients without nosocomial pulmonary infection. One or more etiological agents were identified in 14 patients from the pneumonia group by means of a highly specific technique (protected brush catheter, transthoracic needle aspiration, pleural fluid, and/or blood cultures). The predominant pathogens isolated were Gram-negative bacilli (Acinetobacter sp. and Pseudomonas sp.). Half of the cases were polymicrobial. Compared to other series, our results may reflect with more accuracy the actual incidence of nosocomial pneumonia in mechanically ventilated patients, since we used highly accurate techniques along with autopsy findings which allowed us to confirm or discard the diagnosis of bacterial pneumonia.

Cross Infection↗
PubMed1989

[Application of intrauterine device through the incision of the cesarean section].

Intrauterine devices (IUDs) were applied in 554 women during cesarean sections and the results were compared with the event rates presented in 804 women who received the IUD vaginally immediately postpartum. The expulsion rates at one month were 4.1 for the IUD inserted during the cesarean section and 7.5 for the post partum IUD. The expulsion rates at three months were 10.9 and 16.4 respectively. In a third group of 240 women who had cesarean sections but did not accept the IUD for contraception, the rate of endometritis at one month resulted in 0.8 compared with 1.1 for the group of cesarean section with IUD. Almost two thirds of the cesarean sections in both groups were performed on emergency bases. The application of the transcesarean IUD is considered to be safe procedure for fertility control.

Adult↗
PubMed1989

[Trichinosis: new epidemic outbreak caused by the ingestion of wild-boar sausage].

After the evaluation of 129 serum samples of persons who had ingested boar sausage infested by Trichinella spiralis, 48 individuals (40 adults and 8 children) with a mean age of 38.8 years were diagnosed of trichinosis. The incubation time was 17 days (range 2 to 44 days). The following clinical features were outstanding: facial and eyelid edema (50%), diffuse limb myalgia (43%), fever (37%), conjunctivitis (25%), headache (16%), and abdominal pain (16%). Remarkably, 33% of the diagnosed patients were asymptomatic. The diagnosis was made by an indirect immunofluorescence technique (IIF), which was considered as positive when the titer was higher than 1/20 after considering seroconversion at the beginning of the disease and after 4-6 weeks. Among laboratory abnormalities there was leukocytosis in 15 patients and eosinophilia in 37. The GOT, GPT and CPK enzymes were only slightly increased in a small proportion of patients (8, 10, and 31%, respectively). Forty patients were treated with thiabendazole, associated or not to corticosteroids, which was well tolerated. Eight patients were not treated. One year after the diagnosis a new laboratory control was undertaken in 43 patients (all asymptomatic). Eosinophilia was still present in 12, and the titers against Trichinella were high in all. However, the percentage of the titer was smaller than at the beginning of the outbreak.

Adrenal Cortex Hormones↗