Biomedical subjects

J Díaz

Publications and source records attributed to J Díaz.

At least 37 records · Page 2Linked to original sources

PubMed2002

Prevalence of erectile dysfunction in Colombia, Ecuador, and Venezuela: a population-based study (DENSA).

The purpose of this study was to estimate the prevalence of erectile dysfunction (ED) in Colombia, Ecuador, and Venezuela. A 49-item questionnaire was completed by 1946 men aged 40 years and older. The age-adjusted combined prevalence of minimal, moderate, and complete ED for all three countries was 53.4%, with 19.8% of all men reporting moderate to complete ED. Age was the variable most strongly linked to ED; the prevalence of complete ED increased markedly in men older than 79 y of age (31.9%) and 70-79 y (17.2%) compared with men aged 40-49 y (<3%). Several medical conditions, such as hypertension, benign prostatic hyperplasia, and diabetes, and the use of medications to treat these conditions were correlated with the prevalence of ED. This study corroborates earlier studies demonstrating that ED is very common, increases dramatically with age, and has multiple correlates, including some that are also risk factors for cardiovascular disease.

Adult↗

PubMed2002

[Anterior sacral meningocele with Currarino's syndrome: report of two cases].

The anterior sacral meningocele is the congenital hernia of the thecal sac into the pelvis through a bone defect of the anterior wall of the sacrum. The association of anorectal anomaly, anterior sacral defect and presacral mass, known as Currarino's triad, can be diagnosed during the first decade of life in the eighty per cent of the cases However, in the incomplete syndrome, the symptoms appear in adults. In order to avoid late complications and due to the clear genetic origin of this uncommon pathology, the investigation of the family is of paramount importance for the early diagnosis and treatment. We review the literature and add two cases of anterior sacral meningocele with rectal fistula and incomplete Currarino's syndrome. In one of the cases the pathology is also present in another member of the same family and is complicated with meningitis. The importance of early diagnosis and treatment of these malformations and the need for fammily genetic investigation are discussed.

Adult↗

PubMed2001

Radiative proton capture on (6)He.

Radiative capture of protons is investigated as a probe of clustering in nuclei far from stability. The first such measurement on a halo nucleus is reported here for the reaction 6He(p,gamma) at 40 MeV. Capture into 7Li is observed as the strongest channel. In addition, events have been recorded that may be described by quasifree capture on a halo neutron, the alpha core, and 5He. The possibility of describing such events by capture into the continuum of 7Li is also discussed.

Journal Article↗

PubMed2001

Relationship between atmospheric pressure and mortality in the Madrid Autonomous Region: a time-series study.

This study set out to determine the possible influence of variations in atmospheric pressure on mortality in the Madrid Autonomous Region (MAR), taking into account the possible confounding effect of other atmospheric variables. The study was based on daily mortality data from the MAR Revenue and Excise Authority, meteorological data from Getafe Observatory and air pollution data from the Madrid Municipal Automatic Air Pollution Monitoring Grid. A time-series analysis was performed, using Box-Jenkins modelling and controlling for the respective confounding variables. Furthermore, the different variables studied (pressure, temperature, pollutants, etc.) were used to produce a multivariate model of the different causes of mortality. A significant association was found between anticyclonic trend and mortality with circulatory causes in the medium-long term and anticyclonic trend and mortality with respiratory causes in the long term.

Air Pollution↗

PubMed2001

[Prevalence of sleep apnea-hypopnea syndrome among long-haul professional drivers].

UNLABELLED: Sleep apnea-hypopnea syndrome (SAHS) has been associated with traffic accidents. The aim of this study was to estimate the prevalence of SAHS and analyze risk factors. We studied 163 professional drivers (86.7%) of the 188 employed by 25 participating companies. The subjects completed a questionnaire on SAHS symptoms and risk factors and underwent physical examination and conventional nighttime polysomnographic testing. RESULTS: The prevalence of an apnea-hypopnea index (AHI) ( 5 was 25.2% (95% CI 18.7-32.5) among the drivers. The prevalence of SAHS was 8.6% (95% CI 3.4-12.1). The prevalence increased with age (p = 0.012). Sleepiness while driving or habitual snoring had a sensitivity of 67.5%, specificity of 62.6% and a positive predictive value of 38.6% for detecting SAHS. Logistic regression modelling showed that the risk factors were a body mass index over 29 kg/m2 (OR: 3.56, 95% CI 1.53-8.4) and sleepiness while driving (OR: 3.7, 95% CI: 1.303-10.3). CONCLUSION: These results suggest that detecting SAHS among drivers may be useful for preventing traffic accidents; a questionnaire on SAHS symptoms and objective measures such as polysomnography allow cases to be detected and treated.

Adult↗

PubMed2001

Hydroxyapatite particles are capable of inducing osteoclast formation.

Hydroxyapatite (HA) coatings have been used to improve implant fixation by promoting bone formation around the prosthesis. A macrophage response to HA particulates has been noted around loosened HA-coated prostheses. As biomaterial wear particle-associated macrophages are known to be capable of differentiating into osteoclasts that are capable of bone resorption, we examined whether particulate HA could similarly induce macrophage-osteoclast differentiation. HA-associated macrophages were isolated from granulomas, formed by subcutaneous implantation of HA, and co-cultured with UMR 106 osteoblast-like cells in the presence of 1,25-dihydroxyvitamin D(3) for up to 14 days on glass coverslips and bone slices. HA-associated macrophage-osteoclast differentiation was evidenced by the formation of numerous multinucleated tartrate resistant acid phosphatase (TRAP)-positive cells which formed lacunar resorption pits on bone slices. Polymethylmethacrylate (PMMA) particle-associated macrophages, isolated from subcutaneous PMMA-containing granulomas, caused significantly more osteoclast formation and bone resorption than HA-associated macrophages. These results indicate that macrophages responding to HA particles are capable of osteoclast differentiation. They also suggest that particles derived from uncemented (HA-coated) implants are likely to induce less osteoclast formation and osteolysis than cemented implants.

Journal Article↗

PubMed2001

Use of poisson regression and box-jenkins models to evaluate the short-term effects of environmental noise levels on daily emergency admissions in Madrid, Spain.

The relationship between environmental factors and hospital admissions has usually been analysed without taking into account the influence of a factor closely related to traffic in big cities, that is, environmental noise levels. We analysed the relationship between environmental noise and emergency admissions, for all causes and specific causes in Madrid (Spain), for the study period 1995-1997, using two statistical methods for the analysis of epidemiological time series data: Poisson autoregressive models and Box Jenkins (ARIMA) methodology. Both methods produce a clear association between emergency admissions for all and specific causes and environmental noise levels. We found very similar results from both methods for all and circulatory causes, but slightly different for respiratory causes. Around 5% of all emergency admissions can be attributed to high noise levels, with a lower figure for specific causes. Current levels of environmental noise have a considerable epidemiological impact on emergency admissions in Madrid. A reduction of environmental noise levels could be accompanied by a possible reduction in the number of emergency admissions.

Air Pollutants↗

PubMed2001

Towards a 'human-like' model of tuberculosis: intranasal inoculation of LPS induces intragranulomatous lung necrosis in mice infected aerogenically with Mycobacterium tuberculosis.

It is well known that one of the differences between murine and human tuberculosis is the lack of intragranulomatous necrosis in the former. The aim of this study was to create a feasible and reproducible model of an experimental model of murine tuberculosis in which this necrosis should be present. Considering the Shwartzman reaction as a possible explanation for intragranulomatous necrosis in human tuberculosis, C57Bl/6 mice, infected aerogenically with a virulent strain of Mycobacterium tuberculosis, were intranasally inoculated with lipopolysaccharide (LPS) on day 19 postinfection (p.i.). Twenty-four hours later, neutrophils infiltrated the lung parenchyma in a significant level, and 10 days after necrosis could be detected in the centres of primary granulomas, that showed scanty macrophages and large amounts of collagen on an eosinophilic background. On the other hand, a significant decrease in the concentration of colony forming units (CFU) could be appreciated 24 h after the LPS inoculation. Afterwards, nonbronchogenic spreading of granulomas increased and higher levels of interferon (IFN)-gamma mRNA were detected. These results lend support to the Shwartzman reaction as the origin of the intragranulomatous necrosis in the M. tuberculosis infection, and provides a useful tool to improve experimental murine models in tuberculosis.

Administration, Intranasal↗

PubMed2001

Organizing a public-sector vasectomy program in Brazil.

Although models of high-quality family planning services for men exist in Latin America, few if any have been organized within the complex and resource-constrained national public health systems. This study provides evidence from the Santa Barbara project in southern Brazil showing how vasectomy was introduced into the municipal health system. It demonstrates that once the necessary operational and quality-of-care improvements were in place, and sufficient political and technical support existed to proceed, it was possible to establish low-cost, well-used, and sustainable vasectomy services free of charge. The findings show that careful attention to the development of strong technical competence and an informed choice process resulted in high user satisfaction. Focus-group discussions with men who underwent vasectomy indicate that they had no objection to being served in the context of a women's health center and that they act as opinion leaders who draw an increasing clientele to the service.

Adult↗

PubMed2001

[Antioxidative state and lipid peroxidation in erectile dysfunction: preliminary study].

OBJECTIVE: The aims of this study were to analyze the cavernosal tissue metabolic status of patients with vascular and psychogenic impotence and attempt to establish metabolic differences between these types of erectile dysfunction. METHODS: 103 patients were classified according to the type of erectile dysfunction into group A (vascular) and group B (psychogenic). Diagnosis was based on clinical history, physical examination, intracavernosal injection test, penile echo-doppler assessment, cavernosography-cavernosometry and nocturnal penile test. Cavernosal and peripheral venous blood samples were obtained from each patient and the lipoperoxide (LPO) levels and total antioxidant status (TAS) were determined. SPSS V9.0 was used for the statistical analysis. RESULTS: The mean age was 62 years (range 32-73). Cavernosal blood lipoperoxide levels were statistically higher (p < 0.05) in patients with vascular impotence (2.45 mumol/L) than in those with psychogenic impotence (1.47 mumol/L). Cavernosal blood total antioxidant status was statistically higher (p < 0.05) in patients with psychogenic (1.40 mmol/L) than those with vascular impotence (1.10 mmol/L). The lipoperoxide levels and total antioxidant status for peripheral blood were 1.68 mumol/L vs 1.60 mumol/L and 1.29 mmol/L vs 1.35 mmol/L, respectively, with no statistically significant differences between both groups. CONCLUSIONS: Cavernosal blood lipoperoxide levels and total antioxidant status can be an indicator of cavernosal tissue metabolic status and function.

Adult↗

PubMed2001

A model for forecasting emergency hospital admissions: effect of environmental variables.

This study modeled patterns and trends in emergency hospital admissions at a hospital in Madrid, Spain. The purpose was to quantify qualitative associations that have been detected between such admissions and a number of environmental variables. The following data were used: unscheduled daily emergency hospital admissions, Madrid air pollution data, and meteorological data. Time-series analysis was performed, with Box-Jenkins modeling. A multivariate model was constructed, incorporating the different causes of admissions and the respective environmental variables. Statistically significant associations were found between hospital admissions and other variables, indicating relationships with temperature, relative humidity, and mean daily tropospheric ozone concentrations. Whereas the effect of heat on admissions was short term, that of cold was in evidence from the second week. The association with ozone showed a seven-day lag and basically manifested itself as an influence on admissions for circulatory disease.

Cardiovascular Diseases↗

PubMed2000

Vaccination against Taenia solium cysticercosis in underfed rustic pigs of México: roles of age, genetic background and antibody response.

Vaccination of pigs of mixed genetic make-up, raised as rustically as done in rural Mexico, resulted in effective protection to experimental challenge against Taenia solium cysticercosis. Maximum protection was achieved if pigs were immunized at 70 days of age. There was large variation of viable parasite load within vaccinated pigs and controls, which is suggestive of significant genetic factors influencing susceptibility, besides immunization. Our results strengthen the advisability of pig vaccination for control of T. solium cysticercosis, since it lowers the number of viable cysticerci capable of transforming into tapeworms.

Age Factors↗

PubMed2000

A five-year report on experience in the detection of pheochromocytoma.

OBJECTIVE: The purpose of the study is to identify biochemical tests that are good predictors for the diagnosis of pheochromocytoma in patients at hypertension. SETTING: Review of data from of 3826 patients studied over a 5-year period, between 1994 and 1998, at the University Hospital Virgen de la Arrixaca, Murcia, Spain. DESIGN AND METHODS: A retrospective study for the diagnosis of pheochromocytoma of 24-h urinary free catecholamines (norepinephrine, epinephrine, and dopamine) measured by high-performance liquid chromatography (HPLC)-electrochemical detector (ECD), total metanephrines (MNt), and vanillylmandelic acid measured by spectrophotometric methods. RESULTS: During this period, 57 patients were found to have pheochromocytoma, being 47 sporadic, 9 with multiple endocrine neoplasia type 2A, and 1 with neurofibromatosis. In all patients multiple endocrine neoplasia type 2A the tumor were bilateral but only in four of the sporadic tumor group (p < 0.0001, Fisher's exact test). MNt was determined to be the best discriminator of hypertension and pheochromocytoma. It scored a sensitivity of 94.7% (95% confidence interval, 88.3-99.9%), a specificity of 95.3% (89.5-99.9%), and thus had the best negative predictive value of 99.9% (99.8-99.9%), and this biochemical test also had the best positive predictive value of 23.3% (10.8-59.9%). When combining both MNt and norephinephrine, the positive predictive value to increases to 85.6% (65.3-95.6%). CONCLUSION: Urinary 24-h MNt excretion level is the best single biochemical test for screening and, in combination with norephinephrine, is diagnostic of the presence of pheochromocytoma.

Adolescent↗

PubMed2000

The effect upon the human vaginal histology of the long-term use of the injectable contraceptive Depo-Provera.

The objective of the study was to evaluate the effect of long-term use of the injectable contraceptive depot medroxyprogesterone acetate (DMPA) on human vaginal histology. Twenty premenopausal women currently using DMPA as a contraceptive method for two and three years were compared with 20 regularly menstruating women, who never used Depo-Provera and/or other kind of hormonal contraceptive in the last 6 months prior to the study. Subjects and controls were matched by age (+/-1 year), body mass index (kg/m2) (+/-1.0), number of pregnancies (+/-1), age at first intercourse (+/-1 year), years of sexual activity (+/-1 year), and number of partners during their life (+/-1). Vaginal biopsies were performed in users at 90+/-7 days after the last injection and in nonusers at day 20-25 of the menstrual cycle. In addition, at the day of the biopsy a blood sample was collected to measure estradiol (in all women) and DMPA in users. The level of serum estradiol was significant lower in Depo-Provera users than in controls (p < 0.001). The thickness of the vaginal epithelium was not smaller among DMPA users than among controls, the mean count of Langerhans cells per mm of epithelium were almost identical in both groups, and no significant differences were found on the vaginal maturation indices. In conclusion, the use of Depo-Provera between two and three years did not affect vaginal thinning of the epithelium, Langerhans cell count or maturation index.

Adult↗

PubMed2000

Hormone replacement therapy for oxidative stress in postmenopausal women with hot flushes.

OBJECTIVE: To assess the association of hot flushes during postmenopause with oxidative stress and to determine whether hormone replacement therapy (HRT) affects the plasma redox status of postmenopausal women. METHODS: We conducted a prospective clinical study of 49 postmenopausal women who have (n = 29) or do not have (n = 20) hot flushes. Twelve of the postmenopausal women with hot flushes and six without were treated with HRT (estradiol patches and medroxyprogesterone acetate) for 4 months. Plasma level of estradiol, total antioxidant status, reduced sulfhydryl groups, lipoperoxides, total cholesterol, and triglycerides were measured at 4-month intervals in both groups, before and after treatment. RESULTS: Postmenopausal women who have hot flushes, had lower total basal antioxidant status in plasma (.9 +/-.01 compared with 1.14 +/-.01 mmol/L), lower concentration of reduced sulfhydryl groups (145 +/- 4 compared with 200 +/- 3 micromol/L), and higher concentration of lipoperoxides (2.88 +/-.04 compared with 2.61 +/-.04 micromol/L) than women without hot flushes. After HRT, total antioxidant status and reduced sulfhydryl groups increased, and lipoperoxides decreased similarly in both groups. Hormone replacement therapy decreased the frequency of hot flushes per day from 11.2 +/- 0.8 to 1.4 +/- 0.3. CONCLUSION: Hot flushes in postmenopausal women were associated with the oxidative process. Hormone replacement therapy decreases oxidative stress and the number of episodes of hot flushes. Because oxidative stress is associated with a high risk for cardiovascular diseases, HRT might protect women with hot flushes.

Antioxidants↗

PubMed2000

Fruit development in Capsicum annuum: changes in capsaicin, lignin, free phenolics, and peroxidase patterns.

Pepper fruits, of Capsicum annuum cv. Padron, undergo changes in content of capsaicinoids, lignin, and free phenolics during the maturation process. Although capsaicinoids increase with development, the maximal levels of free phenolics and lignin are observed during the early stages of development. A decrease of peroxidase activity was observed during maturation, and this was related with a decrease in other physiological parameters studied, namely chlorophylls and pH. Subcellular fractionation studies reveal that most peroxidase activity is localized in the soluble fraction throughout development. The changes in the peroxidase activity were accompanied by changes in the different isoenzymes. Acidic isoenzymes increased whereas the basic isoenzymes decreased over the same period, and the changes in these isoenzymes were related with capsaicin metabolism.

Capsaicin↗

PubMed2000

Evolution of granulomas in lungs of mice infected aerogenically with Mycobacterium tuberculosis.

Aerogenous infection of C57Bl/6 mice with a virulent strain of Mycobacterium tuberculosis (CL 511) leads to the formation of primary granulomas in the lung where neutrophils, macrophages and subsequently, lymphocytes accumulate progressively around an initial cluster of infected macrophages. The spread of infection through the lung parenchyma gives rise to secondary granulomas featuring numerous lymphocytes that surround a small number of infected macrophages. Afterwards, foamy macrophages add an outer layer to the granulomas, which characteristically respect the pulmonary interstitium and remain confined within the alveolar spaces. This feature, in conjunction with the constant presence of M. tuberculosis in the products of broncho-alveolar lavage, suggests that the upward bronchial migration of infected macrophages may contribute significantly to pulmonary dissemination of mycobacterial infection. The latter would be in agreement with the persistence of chronic pulmonary infection in spite of a concomitant strong T helper 1 cell response.

Animals↗

PubMed2000

Plasma redox status relates to severity in critically ill patients.

OBJECTIVE: To determine the relation between plasma redox status and severity of illness for patients admitted to an intensive care unit (ICU). DESIGN: A prospective cohort study. SETTING: A mixed medical and surgical adult ICU with 12 beds. PATIENTS: A total of 73 consecutive patients admitted to the ICU. INTERVENTIONS: Venous blood samples were routinely obtained within 24 hrs of admission. MEASUREMENTS AND MAIN RESULTS: Plasma total antioxidant capacity and lipoperoxides were measured by spectrophotometric technique at admission to the ICU. The plasma ratio total antioxidant capacity (mM)/lipoperoxides (microM) was used as an index of plasma redox status. Plasma concentration of the markers of leukocyte activation myeloperoxidase (enzyme-linked immunosorbent assay) and polymorphonuclear-elastase (immunoactivation assay) were also measured at admission to the ICU. Analysis of correlation between plasma ratio total antioxidant capacity/lipoperoxides and APACHE III score showed a negative association (p < .001, Spearman correlation test). Myeloperoxidase and polymorphonuclear-elastase correlated positively with Acute Physiology and Chronic Health Evaluation III scores (r2 = 0.58; p < .001; and r2 = 0.05; p = .035; respectively). CONCLUSIONS: Plasma redox status relates to severity in critically ill patients. We propose that it would be reasonable to provide antioxidant therapy as part of routine management of patients admitted to a mixed ICU, regardless of the specific reason for ICU admission. Plasma redox status might become useful to evaluate the risk in critically ill patients.

APACHE↗