Search PubMed⌕ Search

Biomedical subjects

J Castro

Publications and source records attributed to J Castro.

At least 37 records · Page 2Linked to original sources
PubMed2001

High-LET radiation induces apoptosis in lymphoblastoid cell lines derived from atazia-telangiectasia patients.

PURPOSE: To investigate and compare the propensity of Epstein-Barr virus (EBV)-transformed lymphoblastoid cell lines (LCL), derived from ataxia-telangiectasia (A-T) patients and from unaffected healthy individuals (controls), to undergo apoptosis after exposure to high-linear energy transfer (LET) radiation. MATERIALS AND METHODS: Four A-T (ARO, BMA, CSA and RJO) and two control (JAC and KKB3) LCL were exposed to doses of up to 4Gy of accelerated nitrogen ions (32-45 MeV/u, 8-12Gy/min). For comparative purposes X-ray irradiation (1.36 Gy/min) was also performed. The induction of apoptosis was studied 0-48 h after irradiation with the use of two methods: (1) monitoring of high molecular weight (HMW) DNA fragments by field inversion pulse gel electrophoresis (FIGE); and (2) morphological characterization ofapoptotic cells after fluorescent staining. In parallel, cell-cycle distribution, monitored by DNA flow cytometry, as well as measurements of p53/p21(WAF1) protein levels by Western blots, were investigated in these cells. RESULTS: High-LET radiation-induced apoptosis and G2/M-arrest in both A-T and control LCL. No significant increase in the amount of p53/p21(WAF1) proteins preceded apoptosis in control or in A-T LCL after high-LET irradiation. However, low-LET radiation did induce significant enhanced levels of p53 proteins in control but not in A-T LCL. CONCLUSIONS: LCL from both A-T homozygous and unaffected healthy individuals undergo apoptosis without accumulation of p53/p21(WAF1) proteins after exposure to high-LET radiation. In contrast, low-LET radiation induces apoptosis and significantly increases levels of p53 protein in control but not in A-T LCL.

Apoptosis↗
PubMed2001

Adolescent anorexia nervosa: the catch-up effect in bone mineral density after recovery.

OBJECTIVE: To determine whether bone mineral density (BMD) loss can be reversed in adolescent anorexic patients. METHOD: A prospective study with 108 anorexia nervosa patients (DSM-IV) from 12 to 17 years of age at the Eating Disorders Unit in the Hospital Clinic of Barcelona (Spain). They were first evaluated by dual-energy x-ray absorptiometry in lumbar spine and femoral neck consecutively from 1997 until 1999 and reexamined after 6 to 30 months. Results were compared with normative values of bone mass. RESULTS: Patients with poor outcome (n = 44) had a bone mass loss. Patients with good short-term outcome were divided in two groups. The group with normal BMD at first evaluation (n = 41) had a bone mass gain per year of 3.0% at lumbar spine and 0.5% at femoral neck. The group with low BMD at first evaluation (n = 23) had an increase per year of 9.1% at lumbar spine and 4.5% at femoral neck. In a multiple linear regression analysis with the variables body mass index, age, months with menstruation, and BMD zscore at first evaluation, the only predictor of BMD increase was the first z score both at the lumbar spine (coefficient R = 0.64; p < .001) and at the femoral neck (coefficient R = 0.5; p < .001). CONCLUSIONS: There is a catch-up effect in adolescent patients with low BMD but good short-term outcome.

Adolescent↗
PubMed2001

Clinical isolation and resistance patterns of and superinfection with 10 nosocomial pathogens after treatment with ceftriaxone versus ampicillin-sulbactam.

Isolation of pathogens from clinical cultures and their resistance patterns may be altered by antecedent antibiotic treatment. The objective of this study was to assess the influence of treatment with ceftriaxone versus that with ampicillin-sulbactam on recovery and superinfections with 10 nosocomial pathogens. The study was designed as a historical cohort study, using a propensity score to adjust for confounding by indication and multivariate survival analyses to adjust for other confounding. Two thousand four hundred forty-five patients were treated with ampicillin-sulbactam, and 1, 308 were treated with ceftriaxone. The study analyzed two outcomes: (i) recovery of pathogens from clinical cultures and (ii) microbiologically documented infections. Data were obtained from administrative, pharmacy, clinical, and laboratory databases and by chart extraction. Following treatment, new isolation of at least 1 of the 10 target pathogens occurred for 244 patients. After adjustment, more infections occurred in the ampicillin-sulbactam group (hazard ratio [HR], 1.55; P = 0.009). This was observed with all gram-negative rods combined (HR, 3.6; P < 0.001) and with each genus of the family Enterobacteriaceae. No differences in isolation of gram-positive bacteria were evident (P = 0.33). Microbiologically documented superinfections occurred in 172 patients and were less frequent in the ceftriaxone group (3.8% versus 5%; HR, 1.6; P = 0. 015). All the Escherichia coli and Klebsiella spp. isolates were susceptible to ceftriaxone, but half were resistant to ampicillin-sulbactam. The prevalence of oxacillin resistance among Staphylococcus aureus isolates was higher in the ceftriaxone group (63% versus 31%; odds ratio, 3.8; P = 0.08). Differences in the rates of superinfections and the likely causative organisms following treatment with ceftriaxone or ampicillin-sulbactam were evident. This may guide clinicians in empirical choices of antibiotics to treat superinfection.

Aged↗
PubMed2001

Susceptibility genes for asthma and allergy: hits and questions.

Allergy and asthma are closely related conditions which result from a complex interaction between several genetic and environmental factors. On the basis of familial linkage analysis data from different populations, some chromosomal regions containing a series of susceptibility loci have been identified. To date, genome-wide search studies have reported a group of chromosomal regions which include most likely several candidate genes for asthma and allergy. Some of these genes are excellent candidates, as they are known to modulate the immune response and airways inflammation processes. So, by focusing efforts on the analysis of those chromosomal regions, the characterization of the potentially important genes can be achieved. This will undoubtedly provide a clue for a better understanding of those pathologic components involved in the onset and development of asthma and allergic disorders.

Asthma↗
PubMed2000

Skin and wound infection by rapidly growing mycobacteria: an unexpected complication of liposuction and liposculpture. The Venezuelan Collaborative Infectious and Tropical Diseases Study Group.

OBJECTIVE: To describe 10 patients with skin and soft tissue infection caused by rapidly growing mycobacteria after cosmetic liposuction and liposculpture. DESIGN: Case series. SETTINGS: Eight private geographically separate surgical facilities from a single metropolitan area. PATIENTS: Eight patients with definite and 2 with presumptive cases of skin and soft tissue infection caused by rapidly growing mycobacteria after cosmetic surgery procedures during a 24-month period. Microorganisms were isolated from the purulent drainage obtained from wounds or fistulas in 8 cases and were identified as Mycobacterium fortuitum (3 cases) and Mycobacterium abscessus (5 cases) by routine microbiologic techniques. Acid-fast bacilli were observed on Ziehl-Neelsen-stained smears in the 2 remaining cases, but these ultimately failed to grow. In 2 of the surgical units, no apparent environmental predisposing factors were identified after thorough microbiologic environmental investigation. Clinically, all patients exhibited signs of inflammation, microabscesses, and purulent wound drainage within 24 months of abdominal and/or thigh liposuction or homologous fat tissue injection. INTERVENTION: A combined therapeutic approach including surgical drainage, debridment, and prolonged (>3 months) treatment with combined antimicrobial agents including clarithromycin was used in all cases. RESULTS: Nine of 10 patients responded to the combined therapeutic approach, and no evidence of infection was present during at least 12 months of follow-up. CONCLUSION: To our knowledge, this is the first series of patients with rapidly growing mycobacterial infections to be described after liposuction and liposculpture. Rapidly growing mycobacteria should be included in the differential diagnosis of skin and soft tissue infection after cosmetic surgery.

Abdomen↗
PubMed2000

Quality of rearing practices as predictor of short-term outcome in adolescent anorexia nervosa.

BACKGROUND: Studies of family relationships in anorexia nervosa have produced conflicting results. Some authors claim that family factors are related to short-term outcomes. METHODS: Perceived rearing practices, as measured by the EMBU (Egna Minnen Betraffande Uppfostran: 'My memories of Upbringing') were examined in a sample (N = 158) of adolescents with anorexia nervosa and compared with the perceptions of adolescents (N = 159) from the general population. A further comparison was made between the groups of patients with good and bad short-term outcomes. Logistic regression analysis was performed to evaluate the predictive value of different variables on short-term outcome. RESULTS: Overall, small differences were observed in the perceptions of rearing practices as expressed by the controls and the anorexic patients. Patients with bad short-term outcome perceived more rejection and control-overprotection from both parents than those with good outcome. In the logistic regression analysis only Rejection from father and the EAT (Eating Attitudes Test) total score gave independent prediction of treatment response. CONCLUSIONS: Taken as a whole, these results do not support the idea of altered rearing practices in anorexic patients, at least in young patients with a short evolution of the disease. Perceived rearing practices, especially 'rejection', appear to have an appreciable effect on the short-term outcome.

Adolescent↗
PubMed2000

Cytosolic [Ca(2+)] modulates basal GLUT1 activity and plays a permissive role in its activation by metabolic stress and insulin in rat epithelial cells.

The aim of this work was to investigate the role of cytosolic free calcium ([Ca(2+)]c) in the stimulation of GLUT1 by metabolic stress and insulin. Chelation of [Ca(2+)]c with bapta, introduced in rat liver epithelial Clone 9 cells in the acetoxymethyl (AM) form, decreased their basal rate of 2-deoxyglucose uptake in a dose-dependent fashion. Maximal inhibition at 75 microM bapta was by 38 +/- 8% (n = 8). The effect was partially reversed by ionomycin. Basal sugar uptake was also decreased by lowering extracellular [Ca(2+)] in ionomycin-permeabilized cells. Increasing [Ca(2+)]c over its resting level of 168 +/- 32 (n = 27) had no affect on sugar uptake. Chelation of [Ca(2+)]c did not change the abundance of surface GLUT1 and had no significant effect on the affinity of GLUT1 for sugars. In addition, calcium chelation abolished the activation of GLUT1 by azide, arsenate, 2,4-dinitrophenol and insulin. However, [Ca(2+)]c did not increase in the presence of azide. We conclude that [Ca(2+)]c, near or below its resting level, modulates GLUT1 activity over a considerable range and plays a permissive role in the activation of the carrier by metabolic stress and insulin.

2,4-Dinitrophenol↗
PubMed2000

Predictors of bone mineral density reduction in adolescents with anorexia nervosa.

OBJECTIVES: To determine which variables are associated with a significant reduction in bone mineral density (BMD) in adolescent anorexia nervosa and to establish guidelines for indication of bone densitometry. METHOD: One hundred seventy patients (treated from 1997 until 1999), aged 10 to 17 years, with a DSM-IV diagnosis of anorexia nervosa were evaluated by dual-energy-x-ray absorptiometry in the lumbar spine (L2-L4) and the femoral neck. The results were compared with the normative data for BMD values by age and sex in Spanish adolescents. RESULTS: 44.1% of patients had osteopenia at the lumbar spine and 24.7% at the femoral neck. The following variables were related to osteopenia: more than 12 months since onset of the disorder (p < .001), more than 6 months of amenorrhea (p < .001), body mass index <15 (p < .001), calcium intake <600 mg/day (p < .01), and <3 hours/week of physical activity (p < .001). In a stepwise logistic regression analysis to predict reduced spinal BMD, 3 variables-months elapsed since the onset of weight loss, calcium intake, and body mass index--correctly classified 78.8% of patients. CONCLUSIONS: Adolescent anorexia nervosa patients with the characteristics outlined above are at high risk of reduced BMD, and densitometry is recommended to determine the degree of osteopenia.

Absorptiometry, Photon↗
PubMed2000

Large deletions of chromosome 9p in cutaneous malignant melanoma identify patients with a high risk of developing metastases. Hospital Clinic Malignant Melanoma Group, University of Barcelona.

Cutaneous malignant melanoma (CMM) is an aggressive tumour with a high metastatic potential. Deletions of chromosome 9p have been detected in CMM, some of which involve the CDKN2A/p14ARF genes. Loss of heterozygosity (LOH) of 16 microsatellite markers on 9p and mutations in the CDKN2A/p14ARF genes had been previously studied in 32 melanoma patients by our group. 9p deletions were detected in 15 primary tumours (45.5%) and are here correlated with the clinical outcome over 5 years and compared with classical prognostic factors. Eight of the 32 patients developed metastases (25%). The metastases were all detected within 768 days of the initial diagnosis. The patients without metastases were last monitored at least 1621 days after diagnosis. None of the 21 patients with more than eight microsatellites conserved developed metastases, whereas all of the eight patients who developed metastases had eight or more markers deleted. The sensitivity of this analysis to predict metastases was 100% (specificity 84%), whereas the sensitivity for the same sample using a Breslow thickness > 3 mm was 62.5% (specificity 68%). LOH of eight or more of the 9p microsatellite markers is therefore a useful prognostic factor to predict the development of metastases in the first 4.4-6.3 years (1621-2294 days).

Chromosome Deletion↗
PubMed1999

Gemcitabine plus vinorelbine in nonsmall cell lung carcinoma patients age 70 years or older or patients who cannot receive cisplatin. Oncopaz Cooperative Group.

BACKGROUND: Although the prevalence of nonsmall cell lung carcinoma (NSCLC) is high among elderly patients, few data are available regarding the efficacy and toxicity of chemotherapy in this group of patients. Recent reports indicate that single agent therapy with vinorelbine (VNB) or gemcitabine (GEM) may obtain a response rate of 20-30% in elderly patients, with acceptable toxicity and improvement in symptoms and quality of life. In the current study the efficacy and toxicity of the combination of GEM and VNB in elderly patients with advanced NSCLC or those with some contraindication to receiving cisplatin were assessed. METHODS: Forty-nine patients with advanced NSCLC were included, 38 of whom were age >/= 70 years and 11 were age < 70 years but who had some contraindication to receiving cisplatin. All patients were evaluable for response and toxicity. Treatment was comprised of VNB, 25 mg/m(2), plus GEM, 1000 mg/m(2), both on Days 1, 8, and 15 every 28 days. Patients received a minimum of three courses unless progressive disease was detected. RESULTS: One hundred sixty-five courses were administered, with a median of 3. 6 courses per patient. The overall response rate was 26% (95% confidence interval, 15-41%). Two patients attained a complete response (4%) and 11 patients (22%) achieved a partial response. Eastern Cooperative Oncology Group performance status improved in 35% of those patients with an initial value > 0, whereas relief of at least 1 symptom without worsening of other symptoms was noted in 27 patients (55%). The median time to progression was 16 weeks and the 1-year survival rate was 33%. Toxicity was mild. Six patients (12%) had World Health Organization Grade 3-4 neutropenia, 2 patients (4%) had Grade 3-4 thrombocytopenia, and 2 patients (4%) had Grade 3 neurotoxicity. Three patients with severe neutropenia (6%) died of sepsis. The median age of those patients developing Grade 3-4 neutropenia was significantly higher than that of the remaining patients (75 years vs. 72 years; P = 0.047). CONCLUSIONS: The combination of GEM and VNB is moderately active and well tolerated except in patients age >/= 75 years. This age group had an increased risk of myelosuppression. Therefore the prophylactic use of granulocyte-colony stimulating factor should be considered with this treatment. New chemotherapy combinations with higher activity and lower toxicity are needed for elderly patients with advanced NSCLC.

Age Factors↗
PubMed1999

Molecular mechanisms underlying interferon-alpha-induced G0/G1 arrest: CKI-mediated regulation of G1 Cdk-complexes and activation of pocket proteins.

One prominent effect of IFNs is their cell growth-inhibitory activity. The mechanism behind this inhibition of proliferation is still not fully understood. In this study, the effect of IFN-alpha treatment on cell cycle progression has been analysed in three lymphoid cell lines, Daudi, U-266 and H9. Examination of the growth-arrested cell populations shows that Daudi cells accumulate in a G0-like state, whereas U-266 cells arrest later in G1. H9 cells are completely resistant to IFN-alpha's cell growth-inhibitory effects. The G0/G1-phase arrest is preceded by a rapid induction of the cyclin-dependent kinase inhibitors (CKIs), p21 and p15. In parallel, the activities of the G1 Cdks are significantly reduced. In addition to p21/p15 induction, IFN-alpha regulates the expression of another CKI, p27, presumably by a post-transcriptional mechanism. In the G1 Cdk-complexes, there is first an increased binding of p21 and p15 to their respective kinases. At longer exposure times, when Cdk-bound p15 and p21 decline, p27 starts to accumulate. Furthermore, we found that IFN-alpha not only suppresses the phosphorylation of pRb, but also alters the phosphorylation and expression of the other pocket proteins p130 and p107. These data suggest that induction of p21/p15 is involved in the primary IFN-alpha response inhibiting G1 Cdk activity, whereas increased p27 expression is part of a second set of events which keep these Cdks in their inactive form. Moreover, elevated levels of p27 correlated with a dissociation of cyclin E/Cdk2-p130 or p107 complexes to yield cyclin E/Cdk2-p27 complexes. In resistant H9 cells, which possess a homozygous deletion of the p15/p16 genes and lack p21 protein expression, IFN-alpha causes no detectable changes in p27 expression and, furthermore, no effects are observed on either pocket proteins in this cell line. Taken together, these data suggest that the early decline in G1 Cdk activity, subsequent changes in phosphorylation of pocket proteins, and G1/G0 arrest following IFN-alpha treatment, is not primarily due to loss of the G1 kinase components, but result from the inhibitory action of CKIs on these complexes.

Burkitt Lymphoma↗
PubMed1999

The Body Attitude Test: validation of the Spanish version.

A Spanish version of the Body Attitude Test (BAT) is presented. It was validated with 165 eating disorder patients (79 anorexia nervosa, 86 bulimia nervosa) and 220 schoolgirls from the general population. Factor analysis allowed the extraction of four factors, as in the original questionnaire, but with different item loadings on each. Taken together, these four factors accounted for 67.1% of the variance. The alpha reliability coefficient was 0.92 in both groups. The test-retest reliability with a one-week interval was 0.91 in a subgroup of 34 eating disorder patients and in a subgroup of 43 girls from the general population. The difference between the mean scores of the girls from the general population and the anorexics on one hand and the bulimics on the other was highly significant (p < 0.0001). On the basis of the discriminant validity study, the use of a cut-off point of 41--which gives a sensitivity of 75.1% and a specificity of 72.7%--is recommended.

Adolescent↗
PubMed1999

Parenting style in relation to pathogenic and protective factors of Type A behaviour pattern.

BACKGROUND: Studies of type A behaviour pattern suggest that it can be promoted as a whole by certain parental rearing styles. However, the association of the different components of the type A behaviour with specific rearing practices has not been clarified. METHOD: The relationship between parents' rearing style and the different type A behaviour components of their children was analysed in a sample of 312 university students. Parental rearing style was assessed with the EMBU, a Swedish measure originally designed to assess one's recollections concerning one's parents rearing behaviour. Type A pattern was measured by the JAS, a self-administered questionnaire that gives the global type A score and three of its components. RESULTS: Hard Driving was related to Rejection and Favouring Subject in males. Speed-Impatience was related to Rejection and Control in both sexes, and Job Involvement was related to Control and Favouring Subject in females. In a discriminant factor analysis in males, Rejection, Control and Favouring Subject on the part of fathers classified correctly 80% of the subjects identified as having high or low Speed-Impatience and the variables of Rejection and Favouring Subject (also by fathers) classified correctly 69.23% of the subjects identified as high or low Hard Driving. In females, Control and Favouring Subject on the part of mothers and low Rejection by fathers classified correctly 70.37% of the subjects with high or low Job Involvement. CONCLUSION: These results suggest that different rearing characteristics are related to the various components of the type A behaviour pattern.

Adult↗
PubMed1999

Genetic structure of brown trout, salmo trutta l., at the southern limit of the distribution range of the anadromous form

Genetic variation at 33 protein loci was investigated in 41 wild brown trout populations from four river basins in Galicia (northwest Spain) to analyse the amount and distribution of genetic diversity in a marginal area, located in the distribution limit of the anadromous form of this species. The genetic diversity detected within populations (H between 0 and 6%) lies within the range quoted for this species in previous reports. The Mino, the most southern river basin analysed, showed a significantly lower genetic diversity and the highest genetic differentiation among the river basins studied. The hierarchical gene diversity analysis showed high population differentiation in a restricted area (GST = 27%), mostly due to differences among populations within basins (GSC = 22%). The reduction of GST observed when the isolated samples were excluded from the analysis (GST = 17%) showed the importance of habitat fragmentation on the heterogeneity detected. Gene flow among populations was comparatively evaluated by three indirect methods, which in general revealed low figures of absolute number of migrants per generation, slightly higher than 1. The gene flow among basins reflected a positive relationship with geographical distance. This trend was confirmed by the significant correlation observed between geographical and genetic distances, including all population pairs, which suggests a component of isolation by distance in brown trout genetic structure. Nevertheless, the nonsignificant intrabasin correlation demonstrates the complexity of genetic relationships among populations in this species. The model of genetic structure in brown trout is discussed in the light of the results obtained.

Journal Article↗
PubMed1999

Risk factors for nosocomial candiduria due to Candida glabrata and Candida albicans.

The aims of this study were to analyze the clinical characteristics and risk factors associated with catheter-associated candiduria due to Candida glabrata and due to Candida albicans and to compare patients with candiduria due to C. glabrata or C. albicans (cases) with controls. Controls were a randomly chosen sample of inpatients with Foley catheters for whom urine cultures were negative for Candida species. Univariate and multivariate analyses were performed. There were 40 cases of C. glabrata candiduria and 289 cases of C. albicans candiduria. Factors strongly associated with both C. albicans candiduria and C. glabrata candiduria were female gender (P <. 05) and being in the intensive care unit (P <. 01). Fluconazole use (adjusted odds ratio, 4.37; P <. 01) and quinolone use (adjusted odds ratio, 3.16; P <. 01) were specifically associated with C. glabrata candiduria but not with C. albicans candiduria. In conclusion, patients receiving fluconazole treatment are at risk of developing C. glabrata candiduria.

Aged↗