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Biomedical subjects

E Padilla

Publications and source records attributed to E Padilla.

At least 37 records · Page 2Linked to original sources
PubMed1998

Comparative study of the clinical presentation of Legionella pneumonia and other community-acquired pneumonias.

The aim of this study was to compare the clinical, biological, and radiologic features of presentation in the emergency ward of community-acquired pneumonia (CAP) by Legionella pneumophila (LP) and other community-acquired bacterial pneumonias to help in early diagnosis of CAP by LP. Three hundred ninety-two patients with CAP were studied prospectively in the emergency department of a 600-bed university hospital. Univariate and multivariate analyses were performed to compare epidemiologic and demographic data and clinical, analytical, and radiologic features of presentation in 48 patients with CAP by LP and 125 patients with CAP by other bacterial etiology (68 by Streptococcus pneumoniae, 41 by Chlamydia pneumoniae, 5 by Mycoplasma pneumoniae, 4 by Coxiella burnetii, 3 by Pseudomonas aeruginosa, 2 by Haemophilus influenzae, and 2 by Nocardia species. Univariate analysis showed that CAP by LP was more frequent in middle-aged, male healthy (but alcohol drinking) patients than CAP by other etiology. Moreover, the lack of response to previous beta-lactamic drugs, headache, diarrhea, severe hyponatremia, and elevation in serum creatine kinase (CK) levels on presentation were more frequent in CAP by LP, while cough, expectoration, and thoracic pain were more frequent in CAP by other bacterial etiology. However, multivariate analysis only confirmed these differences with respect to lack of underlying disease, diarrhea, and elevation in the CK level. We conclude that detailed analysis of features of presentation of CAP allows suspicion of Legionnaire's disease in the emergency department. The initiation of antibiotic treatment, including a macrolide, and the performance of rapid diagnostic techniques are mandatory in these cases.

Adult↗
PubMed1997

Direct detection of Mycobacterium tuberculosis complex in nonrespiratory specimens by Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test.

The Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) was adapted for the detection of Mycobacterium tuberculosis complex in 224 nonrespiratory specimens from 188 patients. The sensitivity and specificity of the AMTDT for such specimens, after resolution of discrepant results, were 85.7 and 100%, respectively. Pretreatment of nonrespiratory specimens with sodium dodecyl (lauryl) sulfate is mandatory to obtain consistent and reproducible AMTDT results. The use of 500 microliters of decontaminated specimen improves the sensitivity of the test. Because the AMTDT detects stable rRNA from noncultivable bacilli, it is not useful for monitoring patients receiving treatment.

Bacterial Typing Techniques↗
PubMed1997

Comparison of radioimmunoassay and enzyme immunoassay kits for detection of Legionella pneumophila serogroup 1 antigen in both concentrated and nonconcentrated urine samples.

We evaluated a commercial enzyme immunoassay (EIA) kit for detection of Legionella pneumophila serogroup 1 soluble antigen by comparing it to radioimmunoassay (RIA), using both concentrated and nonconcentrated urine samples. The sensitivity of EIA was 67.4% in nonconcentrated urine samples and 82.6% in concentrated urine samples. The sensitivity of RIA was 60.9% and 84.8% in nonconcentrated and concentrated urine samples, respectively. Our study indicates that the sensitivity and specificity of EIA are comparable to those of RIA, and that concentrating the antigen by selective ultrafiltration increases sensitivity for both EIA and RIA, with no significant decrease in specificity.

Adult↗
PubMed1997

Evaluation of the semiautomated Abbott LCx Mycobacterium tuberculosis assay for direct detection of Mycobacterium tuberculosis in respiratory specimens.

Five hundred twenty processed respiratory specimens from 326 patients received for the diagnosis of tuberculosis or other mycobacterial infections were tested by means of the LCx Mycobacterium tuberculosis Assay from Abbott Laboratories, which uses ligase chain reaction technology for the direct detection of M. tuberculosis complex in respiratory specimens. The results of the LCx M. tuberculosis Assay were compared with the results of culture and staining techniques. After a combination of culture results and the patient's clinical data, a total of 195 specimens were collected from 110 patients who were positively diagnosed as having pulmonary tuberculosis. Twenty-three of these 195 specimens which corresponded to 10 patients with a history of pulmonary tuberculosis (TB) and anti-TB treatment ranging from 1 to 6 months were culture negative. The other 172 specimens were culture positive for M. tuberculosis. With an overall positivity rate of 37.5% (195 of 520 specimens), the sensitivity, specificity, and positive and negative predictive values were 90.8, 100, 100, and 94.7%, respectively, for the LCx M. tuberculosis Assay; 88.2, 100, 100, and 93.4%, respectively, for culture; and 82.6, 92, 72.9, and 97.6%, respectively, for acid-fast staining. For 161 specimens (82.6%) from patients smear positive for the disease and 34 specimens (17.4%) from patients smear negative for the disease, the sensitivity values for the LCx M. tuberculosis Assay were 98.8 and 53%, respectively. There were no statistically significant differences in the sensitivities and specificities between the LCx M. tuberculosis Assay and culture (P > 0.05). Conclusively, the LCx M. tuberculosis Assay has proved to have an acceptable sensitivity and a high specificity in detecting M. tuberculosis and has the potential of reducing the diagnosis time to an 8-h working day.

Bacterial Typing Techniques↗
PubMed1997

Detection and identification of mycobacteria by amplification of RNA and DNA in pretreated blood and bone marrow aspirates by a simple lysis method.

A sodium dodecyl (lauryl) sulfate method was evaluated for the preparation of blood specimens and bone marrow aspirates for use in two amplification procedures (Gen-Probe Amplified Mycobacterium Tuberculosis Direct Test [AMTDT] and Roche Amplicor M. avium/M. intracellulare [MAI] Test) for the detection and identification of Mycobacterium tuberculosis and M. avium and M. intracellulare, respectively. The AMTDT is based on amplification of rRNA, whereas the Amplicor MAI Test amplifies a specific DNA region of the 16S rRNA gene. The results of amplification techniques were compared with those of standard culture and culture in BACTEC 13A and BACTEC 12B liquid media. A total of 121 blood specimens and 15 bone marrow aspirates were collected from 136 AIDS patients. Mycobacterial growth was recovered for 103 specimens; 35 yielded M. tuberculosis, 62 yielded M. avium, 5 yielded M. genavense, and 1 yielded M. kansasii. The values of sensitivity and specificity in pretreated specimens for detection of M. tuberculosis by the AMTDT were 94.3 and 100%, respectively, and those for detection of M. avium by the Amplicor MAI Test were 91.9 and 100%, respectively. The simple lysis method described in the present work allows the recovery of mycobacteria from blood specimens and bone marrow aspirates and may be used in combination with the AMTDT and the Amplicor MAI Test to detect and identify different members of the genus Mycobacterium. This method might also be applicable for the identification of mycobacteria from blood culture fluids with acridinium-ester-labeled DNA probes.

AIDS-Related Opportunistic Infections↗
PubMed1997

Rapid detection of Mycobacterium tuberculosis in respiratory specimens, blood and other non-respiratory specimens by amplification of rRNA.

SETTING: Diagnostic methods employing gene technology based on amplification of DNA or RNA are expected to improve the speed, sensitivity, and specificity of Mycobacterium tuberculosis detection. The Amplified Mycobacterium Tuberculosis Direct Test (AMTDT) enables the amplification and detection of M. tuberculosis rRNA directly from respiratory specimens. OBJECTIVE: To evaluate the performance of the AMTDT in direct detection of M. tuberculosis in respiratory specimens, blood and other clinical samples, and to compare this method with conventional culture and staining techniques. DESIGN: A total of 554 samples from 450 patients were examined in this study. All clinical specimens (with the exception of bone marrow aspirates and blood samples) were digested and decontaminated with sodium dodecyl (lauryl) sulfate (SDS)-NaOH. Bone marrow aspirates and blood samples were treated with 10% SDS. All processed samples were stained by auramine-rhodamine fluorochrome and inoculated onto Löwenstein-Jensen and Coletsos solid media, and into BACTEC-12B medium. In addition, the blood samples were inoculated into BACTEC 13A medium. The AMTDT was performed according to manufacturer's instructions. In those cases where discrepant results were obtained for AMTDT and cultures, patients' clinical data and other microbiological results were evaluated. RESULTS: The sensitivity, specificity, and positive and negative predictive values for AMTDT were 87.5, 100, 100, and 96.7%, respectively, in respiratory specimens and 86.8, 100, 100, and 92.8%, respectively, in non-respiratory specimens. The differences in sensitivity of these two groups of specimens were not highly statistically significant (P > 0.005). CONCLUSION: The sensitivity and specificity of the AMTDT were satisfactory for detection of M. tuberculosis in all types of clinical samples. Some minor changes in assay format and laboratory protocols may increase the sensitivity of the AMTDT without adversely affecting its specificity.

Bacteriological Techniques↗
PubMed1996

Effect of reactive oxygen species on endothelin-1 production by human mesangial cells.

Reactive oxygen species (ROS) have been implicated in the pathophysiology of renal ischemia/reperfusion injury. Endothelin-1 (ET-1) is generated in abundance in renal ischemia/reperfusion with resultant decreases in renal blood flow and glomerular filtration rate. To determine if ROS regulate ET-1 production, the effect of ROS donors or scavengers on ET-1 protein and mRNA levels in cultured human mesangial cells was examined. Incubation with xanthine/xanthine oxidase, glucose oxidase, or H2O2 caused a dose-dependent rise in ET-1 release. Similarly, xanthine/xanthine oxidase or H2O2 augmented ET-1 mRNA levels. In contrast, the ROS scavengers dimethylthiourea (DMTU), dimethylpyrroline N-oxide, or pyrrolidine dithiocarbamate reduced basal ET-1 release, while DMTU lowered ET-1 mRNA levels. Deferoxamine, an iron chelator, also decreased basal ET-1 release. Superoxide dismutase potentiated the ET-1 stimulatory effect of xanthine/xanthine oxidase, while catalase abrogated the effect of xanthine/xanthine oxidase and H2O2. The effects of ROS were unrelated to changes in nitric oxide production or cytotoxicity. These data indicate that exogenously or endogenously-derived ROS can increase ET-1 production by human mesangial cells. While superoxide anion reduces ET-1 levels, H2O2 leads to enhanced production of the peptide. ROS stimulation of mesangial cell ET-1 production may contribute to impaired glomerular hemodynamics in the setting of renal ischemia/reperfusion injury.

Base Sequence↗
PubMed1996

Detection of Legionella pneumophila serogroup 1 antigen in nonconcentrated urine and urine concentrated by selective ultrafiltration.

We evaluated a commercially available radioimmunoassay technique for detecting the soluble antigen of Legionella pneumophila serogroup 1 using concentrated and nonconcentrated urine. Concentration was achieved by selective ultrafiltration. The sensitivity of the technique was 60.9% for nonconcentrated urine and 80.4% for concentrated samples, with 100% specificity in both cases.

Antigens, Bacterial↗
PubMed1995

Three-year study of antibody to Borrelia burgdorferi in southern Spain.

The prevalence of anti-Borrelia burgdorferi antibodies was studied in Granada, Spain, between January 1991 and November 1993 in 354 patients with suspected Lyme disease (group 1); in 50 patients either with syphilis (n = 32) or without syphilis but with a positive Rapid Plasma Reagin test (n = 18) (group 2); and in 150 healthy subjects (group 3). In addition, intrathecal antibody production was evaluated by EIA in CSF samples obtained from 117 patients in group 1. Anti-Borrelia burgdorferi antibodies were detected by EIA in 58 patients (16.4%) in group 1, 29 (8.2%) of whom were positive by Western blot. Intrathecal antibody production was detected in one patient. In group 2, 8 (16%) patients had a positive EIA result, but none of these was confirmed by Western blot. western blot was negative for all subjects in group 3. The results of this study indicate that anti-Borrelia burgdorferi antibodies are not uncommon in our area, although Lyme disease is rare.

Antibodies, Bacterial↗
PubMed1995

Endothelin-1 induction of cyclooxygenase-2 expression in rat mesangial cells.

Prostaglandin E2 (PGE2) may be an important negative feedback modulator of endothelin-1 (ET-1)-stimulated mesangial cell proliferation and contraction. Recent studies suggest that ET-1 may induce prolonged mesangial cell PGE2 production, however the mechanism of this effect is unknown. The current study was undertaken, therefore, to examine the long-term effect of ET-1 on mesangial cell PGE2 synthesis. ET-1 markedly increased PGE2 release by rat mesangial cells for at least six hours. Cyclooxygenase (COX) activity was increased by one hour and persisted for at least six hours. ET-1 increased COX-2, but not COX-1, protein and mRNA levels. Actinomycin D reduced ET-1-stimulated PGE2 synthesis and COX-2 mRNA expression, while cycloheximide superinduced COX-2 mRNA. Dexamethasone decreased ET-1-stimulated PGE2 release and COX-2 protein and mRNA levels. ET-1-stimulated PGE2 release was prevented by BQ-123, an endothelin receptor A antagonist. We conclude that ET-1, via activation of the endothelin A receptor, causes a prolonged increase in mesangial cell PGE2 production that is partially dependent on induction of dexamethasone-inhibitable COX-2.

Animals↗
PubMed1994

Endothelin-1 production by rat inner medullary collecting duct: effect of nitric oxide, cGMP, and immune cytokines.

Nitric oxide (NO), guanosine 3',5'-cyclic monophosphate (cGMP), and endothelin-1 (ET-1) inhibit collecting duct sodium reabsorption. Because the inner medullary collecting duct (IMCD) synthesizes NO and ET-1, we examined NO and cGMP regulation of IMCD ET-1 production. S-nitroso-N-acetylpenicillamine (SNAP, 6 h) increased NO and cGMP and modestly reduced ET-1 release in cultured rat IMCD. Atrial natriuretic peptide or dibutyryl cGMP (6 h exposure to each) also mildly decreased IMCD ET-1 release. In long-term exposure studies, IMCD cells were incubated with tumor necrosis factor (TNF) and interferon-gamma (IFN) up to 72 h. IFN/TNF increased NO and cGMP production while reducing ET-1 release by 84%; N-monomethyl-L-arginine inhibited this effect only marginally, suggesting NO was not primarily involved. IFN alone greatly reduced IMCD ET-1 release and ET-1 mRNA levels. These data indicate that short- and long-term increases in NO and cGMP modestly reduce IMCD ET-1 production. Additionally, IFN potently inhibits IMCD ET-1 release by an undetermined mechanism.

Animals↗
PubMed1993

Anti-inflammatory activity of the essential oil of Bupleurum fruticescens.

The essential oil of Bupleurum fruticescens was investigated qualitatively and quantitatively by GC and GC-MS analyses. The anti-inflammatory activity of the whole essential oil and its major components was also investigated in the rat hindpaw edema model induced by carrageenin or by PGE1. The anti-inflammatory activity shown by the essential oil can be attributed to the two major components, alpha-pinene and beta-caryophyllene. In order to know the role of the adrenal glands in the anti-inflammatory activity exerted by the two major components of the essential oil, they were studied against the carrageenin-induced hindpaw edema in adrenolectomized rats. It is concluded that alpha-pinene needs the integrity of the adrenal glands to exert its anti-inflammatory activity, as opposed to beta-caryophyllene which was also active in adrenolectomized animals.

Animals↗
PubMed1993

Endothelin B receptor mediates ET-1 effects on cAMP and PGE2 accumulation in rat IMCD.

Endothelin (ET) potently inhibits arginine vasopressin (AVP)-induced adenosine 3',5'-cyclic monophosphate (cAMP) accumulation and Na-K-adenosinetriphosphatase (Na-K-ATPase) activity in the inner medullary collecting duct (IMCD). At least two types of ET receptors exist: ETA [binds ET-1 > ET-3 = sarafotoxin S6c (S6c)] and ETB (binds ET-1 = ET-3 = S6c). We examined which of these receptors mediates biological actions of ET in freshly isolated rat IMCD cells. Binding studies revealed comparable displacement of 125I-ET-3 by ET-1, ET-3, and S6c, whereas 125I-ET-1 was displaced by ET-1 >> ET-3 = S6c. Together, these studies confirm the presence of receptors in the IMCD with ETA and ETB binding characteristics. ET-1, ET-3, and S6c were equipotent in reducing AVP-stimulated cAMP accumulation. BQ-123, at concentrations selective for ETA receptor antagonism, did not alter the effect of ET-1, ET-3, or S6c. Pertussis toxin or protein kinase C blockade, but not indomethacin, inhibited the effect of ET-1 and S6c on AVP-stimulated cAMP accumulation, consistent with activation of the same signal transduction pathways. ET-1 and S6c were equipotent in reducing forskolin-stimulated cAMP accumulation, ruling out inhibition of AVP-receptor interaction as a common mechanism of action. Finally, ET-1, ET-3, and S6c caused comparable stimulation of prostaglandin E2 (PGE2) accumulation, an effect that was not blocked by BQ-123. These data indicate that an ETB-like receptor mediates ET stimulation of PGE2 and inhibition of AVP-enhanced cAMP accumulation in the IMCD. The function of the ETA-like receptor in the IMCD remains to be determined.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1993

Osmolar regulation of endothelin-1 production by rat inner medullary collecting duct.

Recent evidence has implicated endothelin-1 (ET-1) as an autocrine inhibitor of inner medullary collecting duct (IMCD) sodium and water transport. The regulators of IMCD ET-1 production are, however, largely unknown. Because of the unique hypertonic environment of the IMCD, the effect of varying extracellular tonicity on IMCD ET-1 production was evaluated. Increasing media osmolality from 300 to 450 mosmol with NaCl or mannitol but not urea caused a marked dose- and time-dependent reduction in ET-1 release by and ET-1 mRNA in cultured rat IMCD cells. In contrast, increasing osmolality had no effect on ET-1 production by rat endothelial or mesangial cells. To see if ET-1 varies in a similar manner in vivo, ET-1 production was assessed in volume expanded (lower medullary tonicity) or volume depleted (high medullary tonicity) rats. Urinary ET-1 excretion and inner medulla ET-1 mRNA were significantly reduced in volume depleted as compared to volume expanded animals. These results indicate that extracellular sodium concentration inhibits ET-1 production specifically in IMCD cells. We speculate that extracellular sodium concentration, via regulation of ET-1 production, provides a link between volume status and IMCD sodium and water reabsorption.

Actins↗
PubMed1993

Perceptual development and early childhood injuries: a prospective pilot study.

A prospective pilot study of 172 Hispanic children was performed to identify developmental predictors of 9 maternal reports of childhood injuries that required medical attention during the following year. The 1972 McCarthy Scales of Children's Abilities was administered near the children's third birthday and maternal reports of injuries were obtained the following year. Multiple regression analysis indicated that the Verbal, Perceptual, Quantitative, Memory, and Motor Subscales of the McCarthy Scales of Children's Abilities accounted for a small but statistically significant proportion of variance. Within the model, children who showed advanced abilities on the Perceptual Subscale were more likely to reported as having an injury requiring medical attention during the subsequent 12-month period.

Child↗