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Biomedical subjects

J Vila

Publications and source records attributed to J Vila.

At least 19 recordsLinked to original sources
PubMed1998

Enteroaggregative Escherichia coli strains as a cause of traveler's diarrhea: a case-control study.

To elucidate the importance of enteroaggregative Escherichia coli (EAggEC) strains as a cause of traveler's diarrhea in Spanish travelers, a prospective case-control 1:1 study was done in a university hospital clinic for travelers. EAggEC strains were isolated from 23 of 165 case-patients and from 4 of 165 controls (P = .0003). In 16 patients, this was the only isolate recovered. Six of the EAggEC-positive isolates from the case-patients and 2 from the controls were positive for the enteroaggregative stable toxin type 1 gene. Other enteropathogens were also isolated. Shigella and enterotoxigenic E. coli strains showed significant differences between cases and controls (P = .0023 and P < .0001, respectively). Geographic distribution of the EAggEC strains was homogeneous, and the clinical symptom, secretory diarrhea, did not differ statistically with that for the enterotoxigenic E. coli strains. EAggEC strains are a cause of secretory diarrhea in Spaniards traveling to developing countries.

Case-Control Studies↗
PubMed1998

Increased resistance to quinolones in Campylobacter jejuni: a genetic analysis of gyrA gene mutations in quinolone-resistant clinical isolates.

Campylobacter jejuni is a frequent cause of enteritis and sometimes it requires antimicrobial therapy. We have studied the evolution of resistance to nine antibiotics from 1990 to 1994 and investigated how frequently gyrA mutations are involved in the acquisition of quinolone resistance. The percentage of chloramphenicol-, clindamycin-, tetracycline- and amoxicillin plus clavulanic acid-resistant strains has remained practically unchanged and erythromycin and gentamicin resistance has decreased, whereas the percentage of ampicillin-, nalidixic acid- or ciprofloxacin-resistant strains has almost doubled in the follow-up period, from 56 to 76% for ampicillin- and from 47.5 to 88% for quinolone-resistant strains. This study clearly shows that a mutation in Thr-86 to Ile or Lys is a frequent mechanism associated with the acquisition of a high level of resistance to quinolones in clinical isolates of C. jejuni.

Anti-Infective Agents↗
PubMed1998

Spontaneous recovery of bacterial vaginosis during pregnancy is not associated with an improved perinatal outcome.

BACKGROUND: Bacterial vaginosis in pregnant women is an established risk factor for premature labor, rupture of membranes, and preterm delivery, but information on its natural history during pregnancy is limited. METHOD AND MATERIAL: In this study, 635 pregnant women at less than 35 weeks' gestation were screened for bacterial vaginosis. RESULTS: The prevalence of bacterial vaginosis, as assessed by Gram stain examination of vaginal smears, was 19.7% (125/635). Ninety-two women were retested 4 to 8 weeks later, and bacterial vaginosis persisted in 51.1% (47/92). The incidence of preterm delivery was significantly increased in women with bacterial vaginosis at enrollment (RR 3.1, 95% CI: 1.8-5.4). However, the risk of prematurity was similar in women with or without a persistence of bacterial vaginosis. CONCLUSION: These results suggest that the diagnosis of bacterial vaginosis at any point during pregnancy is associated with an increased risk of perinatal complications in spite of spontaneous recovery in subsequent examinations.

Abortion, Spontaneous↗
PubMed1998

[Iatrogenic hyperthyroidism secondary to weight loss medication. Predictive factors for their precocious detention].

OBJECTIVE: To establish the differential clinical characteristics between the Iatrogenic hyperthyroidism for not conventional medication for obesity treatment (weight losers) and the endogenous by Graves Basedow disease. PATIENT AND METHODS: Observational and analytical study, populational based, in the one which prospectively were compared cases with Iatrogenic hyperthyroidism (secondary to weight losers) with those with endogenous hyperthyroidism (Graves Basedow disease) as controls. Consisted of the variable clinical record of 100 correlative patients that consulted in specialized attention of endocrinology for Iatrogenic hyperthyroidism secondary to weight losers and for Graves Basedow disease. RESULTS: The differences observed between Iatrogenic hyperthyroidism (secondary to weight losers) (n = 43) as compared to endogenous hyperthyroidism (Graves Basedow disease) (n = 57) were: smaller age (31.8 +/- 10 as compared to 37.8 +/- 12.6 years), greater body mass index (27.6 +/- 7.2 as compared to 23.4 +/- 3.1), smaller goiter frequency (16.3% as compared to 84.2%) as well as absence of signs of ophthalmopathy (0% as compared to 57.9%). Both groups had low levels of TSH, and the difference rests in the values of free T4, low in the first group and increased in the endogenous hyperthyroidism. The odds ratio were: IMC > 27: 3.92 (0.91-16.72), age < 33 years: 5.58 (1.42-21.99), absence of goiter: 23.29 (6.39-84.85). The precedent of weight losers use was not selective of the first group, being detected in a 12.3% of cases of endogenous hyperthyroidism, though in periods of time remoter in relationship to the beginning of the clinic. CONCLUSIONS: In the differential diagnosis of a case of hyperthyroidism, it can be suspected Iatrogenic hyperthyroidism (secondary to weight losers) for medication for the obesity in patients of the feminine sex with overweight, without previous or familiar history of thyroid disease, and in those which in the physical exploration is not verified goiter neither ophthalmopathy.

Adult↗
PubMed1997

Endoscopic evolution of laryngeal injuries caused by translaryngeal intubation.

Despite improvements in tube design and materials, the longer survival rates of critically ill patients make laryngeal and tracheal lesions still common following prolonged translaryngeal intubation. The time of intubation is almost the only factor employed in deciding whether or not tracheotomy has to be performed. Some patients will not develop laryngeal lesions afer long intubation periods, whereas some already have clinical symptoms after short periods of time. If the conditions of the larynx and trachea could be assessed before irreversible complications take place, then timing of tracheotomy could be individualized to avoid laryngeal stenosis as well as unnecessary tracheostomies. We present the preliminary results of an endoscopic study of the early laryngeal changes that take place during translaryngeal intubation. The method of exploration is explained and tissue changes seen and their evolution after extubation are described, emphasizing those that could have a predictive value.

Adolescent↗
PubMed1997

SUTIL: intelligent ischemia monitoring system.

SUTIL is an intelligent monitoring system for intensive and exhaustive follow up of patients in coronary care units. This system processes electrocardiographic and hemodynamic signals in real time, with the main objective of detecting ischemic episodes. In this paper, we describe the tasks included in SUTIL. In addition to basic tasks, those at higher levels will also be presented. Some of these latter tasks attempt to mimic, to some extent, the way in which the human expert operates.

Algorithms↗
PubMed1997

Antibodies to mycobacterial 65-kD heat shock protein cross-react with the main mitochondrial antigens in patients with primary biliary cirrhosis.

Primary biliary cirrhosis (PBC) is a chronic cholestatic liver disease associated with autoimmune disorders. The aetiology is unknown, although it has been suggested that the disease may be related to infectious agents. Previous studies revealed that sera from patients with PBC react against Mycobacterium gordonae. This specific reactivity, characterized by a recognition of two membrane polypeptides of 70-65 and 55 kD, cross-react with the two major mitochondrial autoantigens of PBC. As the most immunogenic components of mycobacteria are the heat shock proteins (hsp), which have been associated with autoimmunity, this study has been undertaken to characterize whether the reacting polypeptides in PBC are hsp from M. gordonae. Cultures of M. gordonae were incubated at 37 degrees C and 46 degrees C before sonication, protein extraction and separation by SDS-PAGE. Exposure of M. gordonae to heat shock treatment resulted in membrane protein overexpression, similar to the 70-65-kD polypeptide recognized by the sera from patients with PBC. Immunoprecipitation assays with a monoclonal antibody directed against the Hsp65 kD of mycobacteria and with sera from patients with PBC revealed similar reacting profiles characterized by the precipitation of the overexpressed 65-kD polypeptide from M. gordonae. Competitive immunoblotting showed that binding of the monoclonal antibody to the Hsp65 kD protein was prevented by preincubation with sera from patients with PBC, but not with sera from healthy subjects. Furthermore, monoclonal antibody to the Hsp65 kD protein recognized the main mitochondrial autoantigens of PBC (PDH-E2 and BCKDH-E2). These data indicate the existence of cross-reacting epitopes contained on M. gordonae Hsp65 kD and the main mitochondrial antigens in patients with PBC.

Antigens, Bacterial↗
PubMed1997

Growth of bacteria in platelet concentrates obtained from whole blood stored for 16 hours at 22 degrees C before component preparation.

BACKGROUND: Previous studies have shown that cooling whole blood to 22 degrees C immediately after collection allows it to be held for up to 16 hours before component preparation (overnight-hold method) without a significant decrease in the quality of components obtained. A study was designated to evaluate the effect of the overnight-hold method on the growth of bacteria in experimentally contaminated blood units. STUDY DESIGN AND METHODS: Twenty whole-blood units were inoculated with Staphylococcus epidermidis (300 colony-forming units [CFU]/mL; n = 10) or Escherichia coli (50 CFU/mL; n = 10) immediately after collection. Half the units of each group were fractionated 6 hours after collection and the other half after storage for 16 hours at 22 degrees C. Twenty additional whole-blood units were divided in two equal parts, one of which was white cell reduced before inoculation. These 40 half-units were inoculated with S. epidermidis or E. coli and processed by the overnight-hold method. The growth of bacteria was assessed in platelet concentrates on the second and fifth days of storage, in packed red cells on Day 35, and in fresh-frozen plasma after 60 days. RESULTS: No bacteria growth was detected in plasma or red cell units. On the second day of storage, both bacteria strains grew more slowly in platelet concentrates obtained from blood processed by the overnight-hold method. This difference disappeared for S. epidermidis on the fifth day. When white cell-reduced and non-white cell-reduced whole-blood units were compared, platelet concentrates from the latter showed a delayed growth of both bacterial strains on the second and fifty days of storage. CONCLUSION: Prolonged storage of whole-blood units at 22 degrees C before component preparation delays bacteria growth. This effect seems to be mediated by white cells.

Blood↗
PubMed1997

Quinolone-resistance mutations in the topoisomerase IV parC gene of Acinetobacter baumannii.

Mutations in the parC gene, which encodes a subunit of topoisomerase IV, were determined in 21 epidemiologically unrelated clinical isolates of Acinetobacter baumannii. Our studies highlight the conserved sequences in the quinolone-resistance-determining region of the parC gene from A. baumannii and other bacteria. Nine of ten isolates with MICs of ciprofloxacin of > or = 32 mg/L showed a change of Ser80 to Leu and one showed a change of Glu84 to Lys. These results suggest that ParC from A. baumannii is a secondary target for quinolones and that mutations at residues Ser80 and Glu84, when combined with mutations at Ser83 of GyrA, may render A. baumannii highly resistant to quinolones.

Acinetobacter↗
PubMed1997

Analysis of the mechanism of quinolone resistance in nalidixic acid-resistant clinical isolates of Salmonella serotype Typhimurium.

Over a period of 2.5 years, 42 cases of gastro-enteritis caused by nalidixic acid-resistant Salmonella serotype Typhimurium occurred in Malaga. The epidemiological relationship among the strains involved was investigated by analysis of plasmid profile and of chromosomal DNA by pulsed-field gel electrophoresis (PFGE). Despite having different plasmid profiles, all 42 nalidixic-acid resistant Typhimurium isolates had evolved from one clone as shown by analysis of chromosomal DNA by PFGE. The mechanism of quinolone resistance in these Typhimurium isolates was also investigated. Analysis of outer-membrane proteins and lipopolysaccharide from quinolone-susceptible and resistant clinical isolates tested showed no differences. All nalidixic acid-resistant isolates had MICs for ciprofloxacin of 0.25 mg/L and for nalidixic acid of 1024 mg/L. Polymerase chain reaction fragments of 285 bp, containing the quinolone resistance-determining region of the gyrA gene, and of 237 bp, containing the region of parC homologous to the quinolone resistance-determining region of the gyrA gene, were sequenced. All resistant isolates presented a change at Ser-83 to Phe in the GyrA protein, but no changes were observed in the ParC protein. These findings indicated that this mutation in gyrA plays a major role in the acquisition of nalidixic-acid resistance in clinical isolates of Typhimurium.

Amino Acid Sequence↗
PubMed1997

Attentional modulation of the cardiac defense response in humans.

How cardiac components of the defense reaction are modulated by attentional factors related to sensory intake versus sensory rejection was examined. Forty-eight men participated in a test of the heart rate response to three presentations of an intense auditory stimulus while performing one of three attentional tasks during the 80 s following stimulus onset: (a) internal (rejection) task, (b) external (intake) task, and (c) no task. Results showed a potentiation of the defense response only under the external attention condition. We concluded that defensive reactions, far from provoking the rejection of the aversive stimulus, require allocation of attention to processing that stimulus in detail.

Acoustic Stimulation↗
PubMed1997

Cloning and nucleotide sequence analysis of a gene encoding an OXA-derived beta-lactamase in Acinetobacter baumannii.

A clinical strain of Acinetobacter baumannii (strain Ab41) that was resistant to all beta-lactam antibiotics tested except ceftazidime, ceftriaxone, ceftizoxime, and imipenem produced three beta-lactamases: a presumptive chromosomal cephalosporinase, a TEM-1-like beta-lactamase (pI 5.4), and a novel OXA-derived beta-lactamase named OXA-21 (pI 7.0). The gene encoding OXA-21 was located in an integron. The nucleotide sequence showed three mutations compared with the sequence of OXA-3, with two being silent; the nonsilent mutation generated a substitution of Ile-217 to Met.

Acinetobacter↗
PubMed1997

Intraspecific characterization of Vibrio tapetis strains by use of pulsed-field gel electrophoresis, ribotyping, and plasmid profiling.

A total of twenty-two strains of Vibrio tapetis, the causative agent of brown ring disease affecting cultured clams, were compared and evaluated in an investigation of strain heterogeneity using pulsed-field gel electrophoresis (PFGE), ribotyping, and plasmid profile analysis. A total of 90.9% of V. tapetis strains tested by using NotI showed the same PFGE pattern, consisting of 15 bands. In contrast, the V. tapetis strains showed a low degree of similarity with six reference Vibrio species tested. All V. tapetis strains harbored a large plasmid of 74.5 kb. This plasmid was not detected in any of the other Vibrio species. In addition, endonuclease restriction analysis of the plasmid content of the strains using EcoRI and HindIII clearly showed that all the strains of V. tapetis possessed the same cleavage pattern. The three enzymes used for ribotyping, PvuII, SmaI, and SalI, yielded patterns with 8 to 12 bands ranging in size from 2 to 23 kb. The application of the SalI and SmaI endonuclease rendered the separation of the strains tested in two ribotypes, while all the V. tapetis strains belonged to the same ribotype when the enzyme PvuII was used.

Bacterial Typing Techniques↗
PubMed1997

Isolation of verotoxin-producing Escherichia coli O-rough:K1:H7 from two patients with traveler's diarrhea.

Two Escherichia coli O-rough:K1:H7 strains producing verotoxin 1 that were isolated from stool samples of two travelers with diarrhea who consulted our clinic after trips to the Indian Subcontinent and Central America were characterized. Both strains were sorbitol negative, the same phenotype presented by E. coli O157:H7, but in contrast they were beta-glucuronidase positive. Low-frequency restriction analysis of chromosomal DNA and pulsed-field gel electrophoresis and repetitive extragenic palindrome-PCR showed that both strains were epidemiologically related. The illness was self-limited in both cases but involved long-duration, watery diarrhea (10 to 50 days) accompanied by abdominal cramps and flatulence. This serotype should be taken into account as a possible cause of traveler's diarrhea.

Adult↗
PubMed1997

[Staphylococcal sepsis associated with platelet transfusion: report of a new case and review of the literature].

Bacterial contamination of blood components is an infrequent although potentially fatal event. Bacterial contamination rate of platelet concentrates (PC) varies between 1/900 to 1/2,000 random donor units. However the risk of symptomatic bacteriemias is lower (between 1/2,000 to 1/12,000 random donor units). The organisms most commonly implicated in contaminated PC are gram-positive bacteria such as coagulase negative Staphylococci, Bacillus cereus or Propionibacterium acnes, although gram-negative organisms are also found that generally are associated to a higher mortality. Here, a fatal case of sepsis due to Staphylococcus carnosus associated to transfusion of a contaminated random donor platelet unit is reported.

Bacteremia↗