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Biomedical subjects

M Díez

Publications and source records attributed to M Díez.

At least 19 recordsLinked to original sources
PubMed2005

Determinants of health system delay among confirmed tuberculosis cases in Spain.

BACKGROUND: Health system delay (HSD) is an important issue in tuberculosis (TB) control. This report investigates HSD and associated factors in a cohort of Spanish culture-confirmed TB patients. METHODS: Data were collected from clinical records. Using logistic regression with two different cut-off points to define HSD (median and 75th percentile), adjusted odds ratios were used to estimate the association between HSD and different variables. RESULTS: A total of 5184 culture-confirmed TB cases were included. Median and 75th percentile HSD were 6 and 25 days respectively. HSD significantly greater than the median was associated with: age >44 years, past or present intravenous drug use, diagnosis at a primary-care centre, prior preventive therapy, positive histology, request for drug-sensitivity testing, presence of silicosis or neoplasia in addition to TB, presence of non-TB related symptoms, and gastrointestinal site. HSD greater than the 75th percentile was related to the same variables, with the exception of diagnosis at a primary-care centre, positive histology, silicosis, non-TB-related symptoms and gastrointestinal site, for which the association disappeared; in contrast, an association with female gender emerged. CONCLUSION: Despite free health care being universally available in Spain, there are some groups of TB patients whose treatment is unduly delayed.

Adolescent↗
PubMed2005

The positioning of rye homologous chromosomes added to wheat through the cell cycle in somatic cells untreated and treated with colchicine.

The arrangement of chromosome pairs 5RL and 7R added to the wild type and the ph1b mutant line of hexaploid wheat are analyzed in 2N somatic root tip cells during the cell cycle relative to the arrangement that chromosomes 5RL show in 4N tapetal cells produced after colchicine treatment. Both homologous chromosome pairs are identified at interphase and mitosis by fluorescence in situ hybridization. In nuclei at interphase, chromosomes appear as discrete domains that show the Rabl orientation. Homologous chromosomes are predominantly non-associated and their positioning seems not to be influenced by the Ph1 gene that suppresses homoeologous meiotic pairing. This pattern of arrangement contrasts with the high level of somatic pairing that sister chromosomes show in the interphase that follows chromosome duplication induced by colchicine. Disruption of pairing observed in some 4N nuclei is produced at c-anaphase which suggests no topological redistribution of homologues during conformation of the new nucleus. Homologous chromosomes show no predominant arrangement in ellipsoidal metaphase plates, which contrasts with the preferential opposite location of homologues in human prometaphase rosettes. Differences between chromosomes in the variation of the length through the cell cycle and in the chromatin morphology when the Ph1 is absent suggest different patterns of chromatin condensation in both chromosomes.

Cell Cycle↗
PubMed2004

Characteristics of tuberculosis patients with positive sputum smear in Catalonia, Spain.

BACKGROUND: Patients with positive sputum smears are those with the capacity to spread infection. The objective of this study was to describe the incidence of tuberculosis in Catalonia (an autonomous community in the northeast of Spain which includes Barcelona) and to determine risk factors associated to patients with positive sputum smear test. METHODS: New cases of tuberculosis detected by active surveillance between May 1996 and April 1997 were studied. The study was analysed as a coincident cases and controls study. The rate of incidence was calculated per 100,000 persons-year. The association of the dependent variable--case of tuberculosis with positive sputum smear--with the remainder of independent variables was determined by odds ratio (OR) with a 95% confidence interval (CI). RESULTS: A total of 2508 cases of tuberculosis were detected. The rate of incidence was 41.4 per 100,000 persons-year. Of these 19.4% (487/2508) were coinfected with HIV and 35.6% (893/2508) presented a positive sputum smear, which implies a rate of 14.7 per 100,000 persons-year. In an adjusted multivariate analysis, cases with positive smears were positively associated with the 15-24 (OR=1.9; 95% CI: 1.4-2.4), 25-34 (OR=2.1; 95% CI: 1.7-2.7) and 35-44 years (OR=1.7; 95% CI: 1.3-2.2) age compared with persons 45 years old and above; with males (OR=1.8; 95% CI: 1.5-2.2) and consumers of alcohol (OR=2.1; 95% CI: 1.7-2.7) and negatively with those under 15 years of age (OR=0.1; 95% CI: 0.1-0.2) and coinfection with HIV (OR=0.5; 95% CI: 0.3-0.7). CONCLUSIONS: Measures to control tuberculosis transmission (prompt diagnosis, study of contacts and directly observed treatments) should be reinforced for male adults with excessive consumption of alcohol.

Humans↗
PubMed2004

Determinants of patient delay among tuberculosis cases in Spain.

BACKGROUND: Patient delay was investigated in a cohort of TB patients identified from May 1996 until April 1997 in 13 Autonomous Regions in Spain. The study covered almost 67% of the total Spanish population. METHODS: Data were collected from clinical records. Using unconditional logistic regression with two different cut-off points to define 'patient delay' (the median and 75th percentile), the association between patient delay and different factors was estimated. RESULTS: A total of 7,037 cases were included. Median and 75th percentile delays were 22 and 57 days respectively. Factors associated with patient delay greater than the median (p<0.05) were: non-respiratory symptoms of TB and age over 14 years, although the effect of age was not linear. Furthermore, an interaction was observed between intravenous drug user (IDU) and HIV status, in that, whereas patient delay was greater in IDUs than in non-IDUs among cases whose HIV status was either negative or unknown, among HIV-positive patients no such IDU-related differences were in evidence. Factors associated with extreme patient delay (greater than the 75th percentile) were essentially the same, but the above-described interaction disappeared, with IDU status showing no direct effect. In addition, likelihood of extreme patient delay increased in the case of alcoholism and female gender and decreased in the case of chronic renal failure, corticoid treatment, prison inmates and residents of old age homes. CONCLUSION: Although there is a universally enjoyed right to health care in Spain, some groups of TB patients could nevertheless be experiencing problems in seeking medical attention.

Adolescent↗
PubMed2004

The B chromosome database.

The database is compiled from the world literature on B chromosomes published between 1906 and 1994, and has 3,484 records. A brief description is given of the history and structure of the database, which runs in Microsoft ACCESS. A downloadable version is available at http://www.bchromosomes.org/bdb/.

Chromosomes↗
PubMed2003

Preoperatively irradiated rectal carcinoma: analysis of the histopathologic response and predictive value of proliferating cell nuclear antigen immunostaining.

OBJECTIVES: To investigate the relationship between the histopathologic effects of preoperative chemoradiotherapy in rectal cancer and the proteins, proliferating cell nuclear antigen (PCNA) and p53. METHODS: Samples from 73 tumors were examined. The histopathologic effects observed in the resected specimens induced by preoperative chemoradiotherapy were correlated with the inmunohistochemical expression of PCNA and p53 in biopsies obtained by rectoscopy before chemoradiotherapy. RESULTS: Thirty-five tumors showed a high PCNA index (48%). Nuclear accumulation of p53 protein was detected in 53 tumors (72%). Specimens were assigned one of four grades based on the amount of residual viable tumor. Three neoplasms (4%) showed complete regression; 8 other carcinomas (11%) showed only small numbers of tumor cells scattered within the field of stromal reaction. In these cases, it was considered that the tumor had responded significantly to radiotherapy. Tumors with a high PCNA index responded to chemoradiotherapy more frequently (8/35; 72%) than tumors with a low index (3/38; 43%) (p = 0.07). p53-negative tumors responded more frequently (4/20; 20%) than positive tumors (7/53; 13.2%) (p = 0.50). When pathologic and immunohistochemical characteristics of the tumors were included in a logistic regression model, only high PCNA index (odds ratio 5.35, 95% confidence interval 1.07-26.7) (p = 0.04) was significantly associated with the histologic response to preoperative chemoradiotherapy. CONCLUSION: High proliferative activity of rectal cancer, as determined by PCNA immunostaining, is predictive of the response to preoperative chemoradiotherapy.

Aged↗
PubMed2002

[Tuberculin test responses of tuberculosis patients].

OBJECTIVE: To determine the response of tuberculosis patients to tuberculin skin tests. METHOD: The results of skin tests used for initial assessment of tuberculosis patients in Catalonia were reviewed (Multicenter Tuberculosis Research Project). Negative skin tests were those with indurations < 5 mm; positive tests were those with indurations measuring > or = 5 mm. Individuals were classed as having or not having risk factors for developing tuberculosis and those without risk factors were classified by age, location and extension of tuberculosis. RESULTS: Negative skin tests were seen in 1,566 patients (23%). Negative tests were more common in patients with risk factors, significantly so in those undergoing immunosuppressant therapy (50%) or with HIV infection (61%). Negative tests were less prevalent in patients with no risk factors (13%) and, among them, in children (1%), in patients between 15 and 29 years of age (10%) or in those with non-pulmonary forms (10%). Negative tests were significantly more prevalent among patients 60 to 74 years of age (27%), those over 74 (44%), and those whose disease was pulmonary and extrapulmonary (26%) or disseminated (64%). No significant differences in induration size of positive skin tests were observed for patients with and without risk factors (including HIV infection or non-infection). A normal distribution of induration size was observed in all groups. CONCLUSIONS: A negative tuberculin skin test for initial assessment should be interpreted in function of the presence or absence of risk factors, age, location or extension of tuberculosis. When a skin test is positive, the response will be similar whether or not an immunodepressant factor is present.

Adolescent↗
PubMed2002

Factors influencing HIV progression in a seroconverter cohort in Madrid from 1985 to 1999.

OBJECTIVE: To study HIV progression from seroconversion over a 15 year period and measure the population effectiveness of highly active antiretroviral therapy (HAART). METHODS: A cohort study of people with well documented dates of seroconversion. Cumulative risk of AIDS and death were calculated by extended Kaplan-Meier allowing for late entry. Cox proportional hazards models were used to study variables associated with HIV progression. To assess the impact of HAART, calendar time was divided in three periods; before 1992, 1992-6, and 1997-9. RESULTS: From January 1985 to May 2000, 226 seroconverters were identified. The median seroconversion interval was 11 months, median seroconversion date was March 1993. 202 (89%) were men, 76% of whom were homo/bisexual. A 66% reduction in progression to AIDS was observed in 1997-9 compared to 1992-96 (HR 0.34 95% CI: 0.16 to 0.70). People with primary education appeared to have faster progression to AIDS compared to those with university studies (HR 2.69 95%CI: 1.17 to 6.16). An 82% reduction in mortality from HIV seroconversion was observed in 1997-9 (HR 0.18 95% CI: 0.05 to 0.68) compared to 1992-6. Progression to death for people with primary education was twice as fast as for those with university education (p 0.0007). People without confirmation of an HIV negative test had faster progression (HR 4.47 95% CI: 1.18 to 16.92). CONCLUSIONS: The reduction in progression to AIDS and death from seroconversion from 1992-6 to 1997-9 in Madrid is likely to be attributable to HAART. HIV progression was faster in subjects with primary education; better educational level may be associated with better adherence to medication.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Meiosis in primary trisomics of rye: considerations for models of chromosome pairing.

Meiotic chromosome pairing of primary trisomics of rye was analysed by electron microscopy in surface-spread prophase I nuclei and compared with light-microscopic observations of metaphase I cells. Despite the large-sized chromosomes of rye, prophase I trivalent frequencies were close to the two thirds expected on a simple model with two terminal independent pairing initiation sites per trisome (set of three homologous chromosomes). Direct observations mostly reveal one pairing partner switch (PPS) in prophase I trivalents, which confirms this supposition. There were no significant differences between the number of trivalent and bivalent plus univalent configurations observed at prophase and metaphase I; therefore, synapsed segments form chiasmata. In all of the trisomics, the three homologues showed variations not only in the number of telomeric C-bands but also in the amount of heterochromatin of these bands, which allowed identification of chromosomes or chromosome arms associated in most metaphase I configurations. In trisomics for chromosomes 2, 3 and 5, some metaphase I chromosome configuration frequencies did not fit those expected under the assumption of random chromosome association among all partners, suggesting the existence of preferences for pairing between two given chromosome arms of the trisome. No preferential associations either at metaphase I or pachytene were observed in the trisomics for chromosome 6. The fit between theoretical pairing models and the experimental data is also discussed.

Cell Nucleus↗
PubMed2000

Bile acid secretion during rat liver carcinogenesis.

Retro-differentiation of liver parenchyma during neoplastic processes is characterized by the expression of tumor antigens, such as alpha-fetoprotein and the placental isoenzyme of glutathione-S-transferase (GST-P). To investigate whether this may also affect a typical liver function such as bile acid secretion was the aim of this work. Rat hepatocarcinogenesis was induced by diethylnitrosamine (i.p., 200 mg/Kg body weight at day 0) and promoted by two-thirds partial hepatectomy (at day 21) plus 2-acetamidofluorene administration (50 mg/Kg body weight, subcutaneously, twice a week from day 14 to day 35). In order to carry out planimetric measurements of neoplastic tissue after immunohistochemical staining, a novel monoclonal antibody (MAb 14.1.3) against GST-P with no cross-reactivity against the major liver isoform of GST (GST-H) was raised. Analysis of total biliary bile acid output using the 3alpha-hydroxysteroid dehydrogenase method indicated that a significant reduction (-26%) occurred during the formation of GST-P-positive foci (12 wk). This was restored to normal values during adenoma formation (16-20 wk), but decreased again during carcinoma transformation (32 wk). These changes were not parallel to that observed in bile flow, which was progressively but slightly decreased throughout the whole period under study. HPLC analysis of bile samples collected for 1 h at different time points during hepatocarcinogenesis revealed that in contrast to what happens during cholestatic disease, a continuous and progressive increase in the cholic acid-to-chenodeoxycholic acid ratio (from 4.4+/-0.5 in control animals to 15.1+/-1.9 in rats with hepatocellular carcinoma) occurs. A significant and transient increase at 16 wk (+120%) in the proportion of bile acids amidated with glycine as compared to those conjugated with taurine was also observed. These results indicate that the mechanisms accounting for the secretion of major bile acids are modified differently at various steps of rat liver tumor development.

2-Acetylaminofluorene↗
PubMed2000

Pairing affinities of the B- and G-genome chromosomes of polyploid wheats with those of Aegilops speltoides.

Chromosome pairing at metaphase I was studied in different interspecific hybrids involving Aegilops speltoides (SS) and polyploid wheats Triticum timopheevii (AtAtGG), T. turgidum (AABB), and T. aestivum (AABBDD) to study the relationships between the S, G, and B genomes. Individual chromosomes and their arms were identified by means of C-banding. Pairing between chromosomes of the G and S genomes in T. timopheevii x Ae. speltoides (AtGS) hybrids reached a frequency much higher than pairing between chromosomes of the B and S genomes in T. turgidum x Ae. speltoides (ABS) hybrids and T. aestivum x Ae. speltoides (ABDS) hybrids, and pairing between B- and G-genome chromosomes in T. turgidum x T. timopheevii (AAtBG) hybrids or T. aestivum x T. timopheevii (AAtBGD) hybrids. These results support a higher degree of closeness of the G and S genomes to each other than to the B genome. Such relationships are consistent with independent origins of tetraploid wheats T. turgidum and T. timopheevii and with a more recent formation of the timopheevi lineage.

Animals↗
PubMed2000

Chromosome structure of Triticum timopheevii relative to T. turgidum.

The chromosome structure of four different wild populations and a cultivated line of Triticum timopheevii (2n = 28, AtAtGG) relative to Triticum turgidum (2n = 28, AABB) was studied, using genomic in situ hybridisation (GISH) and C-banding analysis of meiotic configurations in interspecific hybrids. Two wild accessions and the cultivated line showed the standard C-banding karyotype. The other two accessions are homozygous for translocation 5At/3G and translocations 1G/2G and 5G/6G. GISH analysis revealed that all the T. timopheevii accessions carry intergenome translocations 6At/1G and 1G/4G and identified the position of the breakpoint in translocation 5At/3G. C-banding analysis of pairing at metaphase I in the hybrids with T. turgidum provides evidence that four species-specific translocations (6AtS/1GS, 1GS/4GS, 4GS/4AtL, and 4AtL/3AtL) exist in T. timopheevii, and that T. timopheevii and T. turgidum differ in the pericentric inversion of chromosome 4A. Bridge plus acentric fragment configurations involving 4AL and 4AtL were identified in cells at anaphase I. This result suggests that the paracentric inversion of 4AL from T. turgidum does not exist in T. timopheevii. Both tetraploid species have undergone independent and distinct evolutionary chromosomal rearrangements. The position, intercalary or subdistal, of the breakpoints in species-specific translocations and inversions contrasts with the position, at or close to the centromere, of intraspecific translocations. Different mechanisms for intraspecific and species-specific chromosome rearrangements are suggested.

Anaphase↗
PubMed1999

Evaluation of the SENIC risk index in a Spanish university hospital.

OBJECTIVE: To assess the performance of the Study of the Efficacy of Nosocomial Infection Control (SENIC) risk index for the evaluation of the risk of surgical-site infection (SSI) in a country other than the United States, having a different health system. SETTING: 350-bed university hospital in Spain belonging to the National Health System (Insalud). DESIGN: Observational cohort study of 1,019 patients who underwent consecutive surgery from January to December 1992. Surgical-infection risk factors assessed by the traditional wound-classification system (clean, clean-contaminated, contaminated, and dirty-infected wound) and by the SENIC risk index (length of intervention more than 2 hours, more than three discharge diagnoses, abdominal surgery, and contaminated or dirty-infected wound) were compared by forward logistic regression. RESULTS: The SENIC risk index showed a greater ability to predict SSI than the traditional wound-classification system. The study carried out in our institution reproduced the estimators provided by the SENIC study in the United States. The SENIC risk index provided a stepwise increase in SSI rates, according to the number of factors present, for every traditional wound-classification group. In the case of clean wounds, the incidence of surgical infection (per 100 interventions) increased (1.5, 2.4, 5.3, and 50; P<.001) for patients having from zero to three risk factors of the SENIC risk index. CONCLUSIONS: This study shows that the SENIC risk index results are reproducible, and the index can be used to compare rates of wound infection across countries with different health systems than the United States.

Abstracting and Indexing↗
PubMed1998

Pouch excision for recurrent serrated adenomas following restorative proctocolectomy for juvenile polyposis: report of a case.

PURPOSE: The study contained herein was undertaken to report the case of a patient with juvenile polyposis in whom multiple and rapid recurrence of mixed polyps, with progressive predominance of the adenomatous component, developed in a diverted ileoanal pouch. METHODS: The case of this patient with juvenile polyposis was reviewed. Despite regular surveillance and polypectomies, extensive and multiple recurrences of serrated polyps developed. RESULTS: Because the pouch was never cleared of polyps, a compromise to remove the pouch was decided on. Such a case has not been reported previously. CONCLUSION: Mixed juvenile polyposis may affect any level of the gastrointestinal tract. The ileal pouch and any rectal remnant may incidentally need surgical excision.

Adenomatous Polyps↗
PubMed1998

Clinical, histopathological, cytogenetic and prognostic differences between mucinous and nonmucinous colorectal adenocarcinomas.

OBJECTIVE: To assess the clinical and biological significance of histological typing of colorectal carcinomas. PATIENTS AND METHODS: The retrospective analysis of 142 consecutive patients who underwent surgical resection of a mucinous (MC; n = 27; 19%) or a nonmucinous (nMC; n = 115; 81%) colorectal adenocarcinoma was carried out. The two groups were compared in terms of the clinical features, p53 gene expression (antiserum CM1), proliferating cell nuclear antigen (PCNA) labeling index, DNA ploidy (by flow cytometry), histopathological features, prognosis and recurrence rate. RESULTS: The two types of tumors differed with respect to patient age, location, morphology, pattern of genetic lesions and type of tumor recurrences. Twenty-five percent of the patients with MC and 9% of those with nMC (p = 0.04) were under 50 years of age. The incidences of right MC and left MC were similar, while the majority of the nMC were located on the left side (p = 0.04). The MC were of higher grade and their margins more infiltrative than those of the nMC (p = 0.001 and p = 0.01, respectively), p53 nuclear staining was observed less frequently in the MC than in the nMC (30% vs 55%; p = 0.03). The PCNA labeling index was higher in the nMC (46% vs 21%; p = 0.05). We observed no significant differences with respect to tumor stage, incidence of vascular invasion or prevalence of lymphocytic infiltration. The prognosis was similar in both groups, although their recurrence patterns differed, with a tendency toward locoregional recurrence in the cases of MC. CONCLUSION: These findings suggest that, despite their similar prognoses, these two types of lesions are epidemiologically, phenotypically and genotypically different and, thus, result from distinct carcinogenic pathways.

Adenocarcinoma↗
PubMed1997

Medical factors in the morbidity and mortality associated with emergency colorectal cancer surgery.

OBJECTIVE: To review the results of the analysis and quantification of the influence of medical factors on the morbidity and mortality associated with emergency surgery for colorectal cancer. PATIENTS AND METHODS: We analyze retrospectively the data for 51 patients who underwent emergency surgery: 34 (67%) to treat acute obstruction and 17 (33%) for perforation. The median follow-up period was 18.5 months (3 to 62 months). RESULTS: The main tumor was located in the right colon in 13 patients (25%), in the left colon in 35 (69%) and in, the rectum in 3 (6%). Primary resection was performed in 94% of the patients: without anastomosis in 35% (18 of 51) and with primary anastomosis in 59% (30 of 51); 6% of the tumors were not resectable. The postoperative morbidity was 41%: 29% (10 of 34) occurring in obstructions and 65% (11 of 17) in perforations. The mortality rate was 14% (9% and 23%, respectively). There were statistically significant associations between mortality and the American Society of Anesthesia grading (p < 0.01) and between both the mortality and morbidity and the score for the acute physiology component of APACHE II (p = 0.01, respectively) and the total APACHE II score (p < 0.01 in both cases). The rate of actuarial disease-free survival was 26% at 36 months. Overall survival was 15% at 62 months. A recurrence rate of 48% (14 of 29) has been recorded. CONCLUSIONS: Emergency surgery for colorectal cancer is associated with a high postoperative morbidity and mortality rate, which correlate with the medical status and, particularly, with the acute physiology score of the APACHE II risk stratification system.

APACHE↗
PubMed1996

Prediction of survival and recurrence by serum and cytosolic levels of CEA, CA125 and SCC antigens in resectable non-small-cell lung cancer.

Risk of death and risk of recurrence in 108 potentially curable non-small-cell lung cancer patients were analysed with respect of TNM stage, histological type and carcinoembryonic antigen (CEA), CA125 antigen and squamous cell carcinoma antigen (SCC) levels in serum and cytosol. CA125 and CEA levels were closely related to outcome figures. Multivariate analyses indicated that TNM stage and histological type had the best predictive power, but serum and cytosolic CA125 and serum CEA contained additional, independent prognostic information. Predictive information drawn from serum and cytosolic levels proved mutually complementary. We conclude that CA125 and CEA complement TNM classification and histological type for the purpose of quantifying risk of death or recurrence.

Adenocarcinoma↗