Showing papers by "University of Barcelona published in 1994"

A randomized trial comparing preoperative chemotherapy plus surgery with surgery alone in patients with non-small-cell lung cancer.

Abstract: Background The efficacy of surgery for patients with non-small-cell lung cancer is limited, although recent studies suggest that preoperative chemotherapy may improve survival. We conducted a randomized trial to examine the possible benefit of preoperative chemotherapy and surgery for the treatment of patients with non-small-cell lung cancer. Methods We studied 60 patients (59 men and 1 woman) with stage IIIA non-small-cell lung cancer. The patients were randomly assigned to receive either surgery alone or three courses of chemotherapy (6 mg of mitomycin per square meter of body-surface area, 3 g of ifosfamide per square meter, and 50 mg of cisplatin per square meter) given intravenously at three-week intervals and followed by surgery. All patients received mediastinal radiation after surgery. The resected tumors were evaluated by means of K-ras oncogene analysis and flow cytometry. Results The median period of survival was 26 months in the patients treated with chemotherapy plus surgery, as compared with...

Ventilator-associated pneumonia by Staphylococcus aureus. Comparison of methicillin-resistant and methicillin-sensitive episodes.

Abstract: All episodes of ventilator-associated pneumonia (VAP) caused by Staphylococcus aureus were prospectively analyzed for a 30-mo period. Methicillin-sensitive S. aureus (MSSA) was isolated in 38 episodes and methicillin-resistant S. aureus (MRSA) in 11 others. The two groups were similar regarding sex, severity of underlying diseases, prior surgery, and presence of renal failure, diabetes, cardiopathy, and coma. MRSA-infected persons were more likely to have received steroids before developing infection (relative risk [RR] = 3.45, 95% confidence interval [CI] = 1.38-8.59), to have been ventilated > 6 d (RR = 2.03, 95% CI = 1.36-3.03), to have been older than 25 yr (RR = 1.50, 95% CI = 1.09-2.06), and to have had preceding chronic obstructive pulmonary disease (RR = 2.76, 95% CI = 0.89-8.56) than MSSA-infected patients. MSSA-infected persons were more likely than MRSA-infected patients to have cranioencephalic trauma (RR = 1.94, 95% CI = 1.22-3.09). All patients with MRSA VAP had previously received antibiotics, compared with only 21.1% of those with MSSA infection (p < 0.000001). The incidence of empyema was similar in both groups; nevertheless, the presence of bacteremia and septic shock was more frequent in the MRSA group. Finally, mortality directly related to pneumonia was significantly higher among patients with MRSA episodes (RR = 20.72, 95% CI = 2.78-154.35). This analysis was repeated for monomicrobial episodes, and the difference remained statistically significant. We conclude that MRSA and MSSA strains infect patients with different demographic profiles; previous antibiotic therapy is the most important risk factor for developing MRSA infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival of enteric viruses on environmental fomites

Abstract: The survival of human enteric viruses on several porous (paper and cotton cloth) and nonporous (aluminum, china, glazed tile, latex, and polystyrene) environmental surfaces has been evaluated. Viruses persisted for extended periods on several types of materials commonly found in institutions and domestic environments. The stability of the viruses was generally influenced by environmental factors such as relative humidity (RH), temperature, and the type of surface contaminated. Overall, hepatitis A virus (HAV) and human rotavirus (HRV) were more resistant to inactivation than enteric adenovirus (ADV) and poliovirus (PV). The resistance to the desiccation step appears to be of major significance in determining the survival of a virus dried on fomites. ADV and PV showed a pronounced decrease in titer at this stage, whereas HAV and HRV displayed little decay at the desiccation step. HAV and HRV persistence was not affected by the presence of fecal material. On nonporous surfaces, PV and ADV persisted better in the presence of feces. However, on porous fomites the presence of fecal material had a negative influence on the survival of PV and ADV. Except for HRV, greater virus survival was observed at 4 degrees than at 20 degrees C. PV and HAV survival was enhanced at high RH; the survival of the latter was enhanced at least for nonporous materials. When dried on porous materials, HRV also exhibited greater persistence at high RH. The survival of ADV was not affected by RH. The validity of using bacteriophages of Bacteroides fragilis as indicators of human viruses dried on fomites was evaluated.(ABSTRACT TRUNCATED AT 250 WORDS)

Detection of adenoviruses and enteroviruses in polluted waters by nested PCR amplification.

Abstract: A procedure has been developed for the rapid detection of enteroviruses and adenoviruses in environmental samples. Several systems for virus concentration and extraction of nucleic acid were tested by adding adenovirus type 2 and poliovirus type 1 to different sewage samples. The most promising method for virus recovery involved the concentration of viruses by centrifugation and elution of the virus pellets by treatment with 0.25 N glycine buffer, pH 9.5. Nucleic acid extraction by adsorption of RNA and DNA to silica particles was the most efficient. One aliquot of the extracted nucleic acids was used for a nested two-step PCR, with specific primers for all adenoviruses; and another aliquot was used to synthesize cDNA for a nested two-step PCR with specific primers for further detection of seeded polioviruses or all enteroviruses in the river water and sewage samples. The specificity and sensitivity were evaluated, and 24 different enterovirus strains and the 47 human adenovirus serotypes were recognized by the primers used. The sensitivity was estimated to be between 1 and 10 virus particles for each of the species tested. Twenty-five samples of sewage and polluted river water were analyzed and showed a much higher number of positive isolates by nested PCR than by tissue culture analysis. The PCR-based detection of enteroviruses and adenoviruses shows good results as an indicator of possible viral contamination in environmental wastewater. Images

Cystinuria caused by mutations in rBAT , a gene involved in the transport of cystine

Abstract: Cystinuria is a classic heritable aminoaciduria that involves the defective transepithelial transport of cystine and dibasic amino acids in the kidney and intestine. Six missense mutations in the human rBAT gene, which is involved in high–affinity transport of cystine and dibasic amino acids in kidney and intestine, segregate with cystinuria. These mutations account for 30% of the cystinuria chromosomes studied. Homozygosity for the most common mutation (M467T) was detected in three cystinuric siblings. Mutation M467T nearly abolished the amino acid transport activity induced by rBAT in Xenopus oocytes. These results establish rBAT as a cystinuria gene.

A set of keys for biochemical identification of environmental Vibrio species

Abstract: A set of biochemical keys which provide fast and presumptive identification for Vibrio spp. is presented. They have been specially designed for environmental isolates, and can be used for strains that are Gram-negative, give a positive oxidase test, grow on TCBS medium and are facultative anaerobes. The keys are constituted by 28 tests and a maximum of 10 tests are needed for the most complicated identification. They have been designed for routine purposes, especially for studies with a high number of isolates. Some tests are included in enzyme-activity based kits that could be used with these keys through certain results, principally for environmental isolates, should be confirmed by standard methods.

The origin of the major cystic fibrosis mutation (ΔF508) in European populations

Abstract: delta F508 is the most frequent cystic fibrosis (CF) mutation and accounts for approximately 70% of CF chromosomes worldwide. Three highly polymorphic microsatellite markers have been used to study the origin and evolution of delta F508 chromosomes in Europe. Haplotype data demonstrate that delta F508 occurred more than 52,000 years ago, in a population genetically distinct from any present European group, and spread throughout Europe in chronologically distinct expansions, which are responsible for the different frequencies of delta F508 in Europe.

Antibracket, Antifields and Gauge-Theory Quantization

Abstract: The antibracket formalism for gauge theories, at both the classical and quantum level, is reviewed. Gauge transformations and the associated gauge structure are analyzed in detail. The basic concepts involved in the antibracket formalism are elucidated. Gauge-fixing, quantum effects, and anomalies within the field-antifield formalism are developed. The concepts, issues and constructions are illustrated using eight gauge-theory models.

SERUM CYTOKINES (IL-6, TNF-α, IL-1β AND IFN-γ) IN ANKYLOSING SPONDYLITIS: A CLOSE CORRELATION BETWEEN SERUM IL-6 AND DISEASE ACTIVITY AND SEVERITY

Abstract: The aim of our study was to analyse the serum interleukin-6 (IL-6), tumour necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta) and interferon-gamma (IFN-gamma) levels in patients with AS and their relationship with disease activity. An ELISA test was used to analyse serum cytokine (IL-6, TNF-alpha, IL-1 beta and IFN-gamma) levels in 69 patients with AS. Results were compared with those from 43 patients with RA and 36 patients with non-inflammatory back pain. The relationship between serum concentrations of the different cytokines and parameters of disease activity and severity in AS patients was also evaluated. IL-6 and TNF-alpha serum levels, but not IL-1 beta and IFN-gamma, were significantly higher in AS than in NIBP. However, patients with RA showed higher serum levels of IL-6, TNF-alpha and IFN-gamma than both AS and NIBP patients. In AS, IL-6 correlated with clinical parameters of disease activity with significant correlation being observed with laboratory parameters of inflammation such as ESR, CRP, platelet count and clinical parameters of severity such as vertebral mobility. TNF-alpha did not correlate with laboratory or clinical parameters of activity. Macrophagic cytokines (TNF-alpha and IL-6), are increased in AS patients and IL-6 closely correlated with the activity of the disease.

Validation of different techniques for the diagnosis of ventilator-associated pneumonia. Comparison with immediate postmortem pulmonary biopsy.

Abstract: To assess the accuracy of clinical parameters for the diagnosis of ventilator-associated (VA) pneumonia, as well as the diagnostic value of several invasive techniques, such as protected specimen brush (PSB), bronchoalveolar lavage (BAL), fiberoptic bronchial aspirates (FBAS), and percutaneous lung needle aspiration (PLNA), we compared the results of these techniques with the histopathology of immediate postmortem pulmonary biopsies, considered the "gold standard" reference test. We studied 30 mechanically ventilated patients (age 52 +/- 21 yr; mechanical ventilation period 9 +/- 7 days) who died in an intensive care unit. All patients received prior antibiotic treatment. The following procedures were performed immediately after death: bilateral PSB, BAL, FBAS, and PLNA, as well as bilateral minithoracotomies to obtain pulmonary biopsies as close as possible to the area sampled with the other techniques. According to the histopathology 18 patients had pneumonia and 12 did not. The presence of fever (sensitivity 55%, specificity 58%), purulent secretions (sensitivity 83%, specificity 33%), and chest radiograph infiltrates (sensitivity 78%, specificity 42%) could not differentiate in all instances presence from absence of pneumonia. Quantitative bacterial cultures of lung biopsies using 10(3) cfu/g as a cutoff point had low sensitivity (40%) and low specificity (45%) and could not differentiate the histologic absence or presence of pneumonia. Considering the histopathology of pulmonary biopsies as a gold standard, we found the following sensitivities for PSB, BAL, FBAS, and PLNA: 36, 50, 44, and 25%. The specificities were 50, 45, 48, and 79%, respectively. The sensitivities and specificities of different invasive techniques are much lower than those reported in clinical studies.(ABSTRACT TRUNCATED AT 250 WORDS)

Validation of different techniques for the diagnosis of ventilator-associated pneumonia : comparison with immediate postmortem pulmonary biopsy

Abstract: To assess the accuracy of clinical parameters for the diagnosis of ventilator-associated (VA) pneumonia, as well as the diagnostic value of several invasive techniques, such as protected specimen brush (PSB), bronchoalveolar lavage (BAL), fiberoptic bronchial aspirates (FBAS), and percutaneous lung needle aspiration (PLNA), we compared the results of these techniques with the histopathology of immediate postmortem pulmonary biopsies, considered the «gold standard» reference test. We studied 30 mechanically ventilated patients (age 52±21 yr; mechanical ventilation period 9±7 days) who died in an intensive care unit. All patients received prior antibiotic treatment

Effective mass of one 4He atom in liquid 3He.

Abstract: A microscopic calculation of the effective mass of one $^{4}\mathrm{He}$ impurity in homogeneous liquid $^{3}\mathrm{He}$ at zero temperature is performed for an extended Jastrow-Slater wave function, including two- and three-body dynamical correlations and also backflow correlations between the $^{4}\mathrm{He}$ atom and the particles in the medium. The effective mass at equilibrium density, m〈main${\mathrm{〉}}_{4}^{\mathrm{*}}$/${\mathit{m}}_{4}$=1.21, is in very good agreement with the recent experimental determination by Edwards et al. The three-particle correlations appear to give a small contribution to the effective mass and different approximations for the three-particle distribution function give almost identical results for ${\mathit{m}}_{4}^{\mathrm{*}}$/${\mathit{m}}_{4}$.

Evaluation of a sequential extraction procedure for the determination of extractable trace metal contents in sediments

Abstract: The determination of extractable trace metals in sediments using sequential extraction procedures has been performed in many laboratories within the last ten years in order to study environmental pathways (e.g. mobility of metals, bounding states). However, the results obtained by different laboratories could hardly be compared due to lack of harmonized schemes. Owing to the need for standardization and subsequent validation of extraction schemes for sediment analysis, the Measurements and Testing Programme (formerly BCR Programme) of the European Commission has organized a project to adopt a sequential extraction procedure that could be used as a mean of comparison of data of extractable trace metals in sediments. A scheme was designed after a series of investigations on existing schemes and tested in interlaboratory studies. This paper presents the results of two round-robin exercises on extractable trace metals using this sequential extraction protocol and describes the final version of the extraction procedure amended according to the most recent improvements.

Increased gelatinase A (MMP-2) and cathepsin B activity in invasive tumor regions of human colon cancer samples.

Abstract: Gelatinase A (MMP-2) and cathepsin B are proteinases which have been proposed to participate in human tumor invasion and metastasis. Precise quantitation of the activity of these enzymes in invading tumors has not been previously described. We utilized a novel tissue microdissection technique to determine levels of enzyme activity in specific microscopic areas of invasive human colon cancer. Tissue specimens smaller than one high power field can be extracted from the samples and analyzed. Increased levels of pro-enzyme and active enzyme forms of gelatinase A (MMP-2) and increased cathepsin B activity were localized in regions of tumor invasion as compared with a matched number of normal epithelial cells from the same patient. Levels of progelatinase B (MMP-9) were also increased in the tumors; however, we did not observe activation of this enzyme. To investigate the mechanism of gelatinase A activation, we amplified DNA of specific microdissected tumor cell populations using polymerase chain reaction. We did not detect a mutation in the activation locus of the enzyme in any of the tumors studied, which suggests that activation may be due to up-regulation of a tumor-associated gelatinase A activating species. Microdissection of frozen tissue sections may prove valuable in the study of proteinases in human tumor invasion as well as in the detection of genetic alterations in human cancers.

Association between double mutation in gyrA gene of ciprofloxacin-resistant clinical isolates of Escherichia coli and MICs.

Abstract: The mutations in the quinolone resistance-determining region of the gyrA and gyrB genes from 27 clinical isolates of Escherichia coli with a range of MICs of ciprofloxacin from 0.007 to 128 micrograms/ml and of nalidixic acid from 2 to > 2,000 micrograms/ml were determined by DNA sequencing. All 15 isolates with ciprofloxacin MICs of > or = 1 micrograms/ml showed a change in Ser-83 to Leu of GyrA protein, whereas in clinical isolates with a MIC of > or = 8 micrograms/ml (11 strains), a double change in Ser-83 and Asp-87 was found. All isolates with a MIC of nalidixic acid of > or = 128 micrograms/ml showed a mutation at amino acid codon Ser-83. Only 1 of the 27 clinical isolates of E. coli analyzed showed a change in Lys-447 of the B subunit of DNA gyrase. A change in Ser-83 is sufficient to generate a high level of resistance to nalidixic acid, whereas a second mutation at Asp-87 in the A subunit of DNA gyrase may play a complementary role in developing the strain's high levels of ciprofloxacin resistance.

Chronotype and personality factors in the daily consumption of alcohol and psychostimulants

Abstract: This paper analyses the influence of and possible interaction between chronotype (Morning-types, Neither-types and Evening-types} and personality dimensions (neuroticism, extroversion and psychoticism) in the daily consumption of alcohol and psychostimulants (nicotine and caffeine). In a sample of 537 subjects (257 men and 280 women), who were students and professionals with different but fixed work schedules, there were significant differences among the chronotypes regarding the consumption of all the above. Evening-types consumed more alcohol, nicotine and caffeine (coffee and cola), while Morning-types consumed more caffeine from tea. Personality was only related to the consumption of cola: the greater the neuroticism the higher the consumption of this beverage. Stimulant drinks showed various types of interaction with personality types, which revealed a complex pattern of group action. The results stress the need to consider chronotype as a contributory psychological factor in a multi-causal model of consumption of psychoactive substances.

Cathepsin B expression in colorectal carcinomas correlates with tumor progression and shortened patient survival.

Abstract: Cathepsin B is a lysosomal cysteine proteinase that has the ability to degrade several extracellular matrix components at both neutral and acidic pH and has been implicated in the progression of several human and rodent tumors. We have studied the expression of cathepsin B in human colorectal tissues using a monospecific polyclonal rabbit antibody raised against human liver cathepsin B. In immunoblots of normal and neoplastic colorectal tissues this antibody specifically recognized only cathepsin B. We studied 101 cases of formalin-fixed, paraffin-embedded tissue (15 normal mucosa, 17 adenomas, and 69 carcinomas). Epithelial cells of normal mucosa and adenomas were either negative or showed a weak granular reactivity located in the paranuclear and apical cytoplasm of superficial cells. Small clusters of histiocytes were also positive in the region of the superficial area of the lamina propria. In carcinomas, increased expression of cathepsin B correlated with advanced stage of the disease. Increased immunoreactivity of cathepsin B in malignant cells was associated with either a diffuse cytoplasmic staining or was polarized to the basal pole of the cells. This is in contrast to the punctate paranuclear staining pattern observed in normal colonic mucosal cells. In tumor stromal cells, increased expression of the enzyme correlated with neoplastic progression. Expression of high levels of cathepsin B in the tumor epithelial cells was associated with a significantly shorter survival of the patients. In conclusion, our results indicate that cathepsin B expression is up-regulated in human colorectal carcinomas compared with normal mucosa and adenomas and correlates with tumor progression.

Updated Hessian matrix and the restricted step method for locating transition structures

Abstract: A family of the updated Hessian matrices for locating transition structures is presented. An analysis and improvement of the restricted step algorithm described by Culot et al. is proposed. The efficiency of the latter method is compared with other well-established methods for locating transition structures. © 1994 by John Wiley & Sons, Inc.

Bone mineral density of the lumbar spine in white Mediterranean Spanish children and adolescents : Changes related to age, sex, and puberty

Abstract: Bone mineral content was measured by dual-energy x-ray absorptiometry in the lumbar spine at the L2-L4 level with a Lunar DPX densitometer model in 471 healthy white Mediterranean Spanish children and adolescents (256 boys and 215 girls) randomly selected from the urban area of Barcelona. Ages ranged from 3 mo to 21 y. Weight, height, and pubertal development were in the normal age distribution. Bone mineral content values were corrected by the vertebral surface area scanned and expressed as bone mineral density (BMD) values. BMD increased progressively from infancy to adulthood, and values were similar in both sexes, with the only differences related to the earlier onset of puberty in girls. A statistically significant correlation (p < 0.001) was found between BMD values and age, height, and weight. BMD values increased annually, but the periods of higher increase were observed during the first 3 y of life and late puberty. A significant (p < 0.001) increase in BMD was observed between Tanner pubertal stages III and IV and between Tanner stage IV and adult values. Lumbar BMD values peaked in a similar way to growth height velocity during pubertal development. However, the BMD peak seemed to occur somewhat later than height velocity peak, particularly in girls. In conclusion, we report normative data for BMD values at the lumbar level in our normally growing pediatric population and show that the first 3 y of life and adolescence are critical periods for bone mineralization. These data provide a tool for the investigation and follow-up of pediatric populations at risk for low bone mineralization.

Effect of chronic ethanol feeding on glutathione and functional integrity of mitochondria in periportal and perivenous rat hepatocytes.

Abstract: Chronic ethanol feeding selectively impairs the translocation of cytosol GSH into the mitochondrial matrix. Since ethanol-induced liver cell injury is preferentially localized in the centrilobular area, we examined the hepatic acinar distribution of mitochondrial GSH transport in ethanol-fed rats. Enriched periportal (PP) and perivenous (PV) hepatocytes from pair- and ethanol-fed rats were prepared as well as mitochondria from these cells. The mitochondrial pool size of GSH was decreased in both PP and PV cells from ethanol-fed rats either as expressed per 10(6) cells or per microliter of mitochondrial matrix volume. The rate of reaccumulation of mitochondrial GSH and the linear relationship of mitochondrial to cytosol GSH from ethanol-fed mitochondria were lower for both PP and PV cells, effects observed more prominently in the PV cells. Mitochondrial functional integrity was lower in both PP and PV ethanol-fed rats, which was associated with decreased cellular ATP levels and mitochondrial membrane potential, effects which were greater in the PV cells. Mitochondrial GSH depletion by ethanol feeding preceded the onset of functional changes in mitochondria, suggesting that mitochondrial GSH is critical in maintaining a functionally competent organelle and that the greater depletion of mitochondrial GSH by ethanol feeding in PV cells could contribute to the pathogenesis of alcoholic liver disease.

Applicability of the International Index for aggressive lymphomas to patients with low-grade lymphoma

Abstract: PURPOSEVariables used to build up the International Index for aggressive lymphomas (age, performance status, stage, extranodal involvement, and lactic dehydrogenase [LDH]) are also important in low-grade lymphoma. To assess the prognostic value of this index in low-grade lymphoma, we have applied it to a series of 125 patients.PATIENTS AND METHODSOne hundred twenty-five patients with low-grade lymphoma who were diagnosed at a single institution over a 20-year period and treated with standard chemotherapy were studied. End points of the study were response to therapy and survival according to the International Index. In addition to the International Index, main initial and evolutive variables were evaluated. Univariate and multivariate methods were used.RESULTSAfter applying the International Index, the patients divided into four risk groups: low (36% of cases), low-intermediate (32%), high-intermediate (20.8%), and high (11.2%), with complete response (CR) rates in the four groups being 60%, 35%, 23%, and...

A general formulation for raindrop size distribution

Abstract: A general phenomenological formulation for drop size distribution (DSD), written down as a scaling law, is proposed. It accounts for all previous fitted DSDs. As a main implication of the expression proposed, the integral rainfall variables are related by power functions and agree with experimental evidence. Additional consequences are also analyzed. From this formulation there follows a general methodology for scaling all data in a unique plot, leading to more robust fits of the DSD. An illustrative example on real data is provided.

The organization of the embronic and early postnatal murine hippocampus. II. Development of entorhinal, commissural, and septal connections studied with the lipophilic tracer DiI

Abstract: We have analyzed the early development of the main hippocampal afferents in the mouse. Following injections of the lipophilic tracer 1–1′-dioctadecyl-3, 3, 3′, 3′-tetramethylindocarbocyanine perchorate (DiI) in the entorhinal cortex, entorhinal axons were observed for the first time inthe hippocampus at E15, in the white matter, At E17, entorhinal fibers arborized within the stratum lacunosum-moleculare. At subsequent stages entorhinal axons formed dense networks that were restricted to their appropriate termination zone in the lacunosum-moleculare. The first axons invading the fascia dentata were noticed at E19, their density increasing at later stages. These axons were mainly present in the outer molecular layer. This onset of entorhinohippocampal projections was corroborated by retrograde labeling data after injections in the hippocampus. Commissural fibers first entered the contralateral hippocampus at E18, their number increasing at the following stages. Commissural axons arborized within the stratum oriens and radiatum in the hippocampus proper. In the fascia dentata, the earliest commissural fibers were seen at P2, terminating in the inner zone of the molecular layer and in the hilus. We conclude that developing entorhinal and commissural axons show a high degree of laminar specificity from the earliest stages of formation, which is compatible with the notion that distinct subsets of early maturing neurons populating the hippocampal plexiform layers may attract particular fiber systems. Hippocamposeptal fibers develop at E15, before the first septal fibers can be detected in the hippocampus. These early hippocamposeptal fibers originated from nonpyramidal neurons and terminated in the medial septal area, which is the main source of septal afferents to the hippocampus. In contrast, septohippocampal fibers were not seen in the hippocampus until E17. At perinatal stages, the hippocamposeptal connection reshapes, sending axons to the dorsolateral septal area as the innervation of the medial septum becomes less conspicuous. This sequence suggests that hippocampal neurons pioneer the formation of septohippocampal connections. © 1994 Wiley-Liss, Inc.