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Biomedical subjects

M J Hernández

Publications and source records attributed to M J Hernández.

At least 19 recordsLinked to original sources
PubMed2002

[Evaluation of a workplace anti-smoking program at a company with 640 employees].

OBJECTIVES: Awareness of the health risks of passive smoking for non-smokers has led to the development of workplace interventions for smokers, although they are still few in our setting. The objective of this study was to evaluate the efficacy of an anti-smoking program among the workers of a company, in function of changes in the pre- and post-intervention prevalence of smoking in the study population. METHOD: A pre-intervention questionnaire on smoking (prevalence and attitudes) was administered at a company with 640 employees (92% men, 8% women). An anti-smoking program was carried out inside the company during working hours over the next nine months. The questionnaire was then repeated (post-intervention) in order to evaluate its efficacy based on changes. For employees who answered both questionnaires, paired variables were analyzed. RESULTS: The pre-intervention questionnaire was answered by 388 employees (60%), 357 men (92%) and 31 women (8%); their mean age was 48.4 years (SD 9.36). The prevalence of smoking was 55%, including daily smokers, sporadic smokers and others. The mean number of cigarettes per day was 17.86 (SD 2.45). The mean level of nicotine dependence measured by the Fagerström test was 3.3 (SD 2.8) out of 10. The post-intervention questionnaire was answered by 206 employees (32%). Among employees who answered both questionnaires (83), analysis of paired data showed a decrease in the prevalence of smoking of 4% and in the number of cigarettes per day from 17.4 (pre-intervention) to 16.4 (post-intervention). The differences were not statistically significant. CONCLUSIONS: Although the workplace is an appropriate setting for anti-smoking interventions that would contribute to improving the health of smokers, such programs are currently underutilized.

Adult↗
PubMed2000

A time-dependent expression for thixotropic areas. Application to aerosil 200 hydrogels.

Experimental determination of the areas enclosed under the up curve, sigma = sigma(;gamma), corresponding to time zero, and the down curve, which would be obtained following complete rheodestruction of the system structure, is not an easy matter. In the present study a semi-empirical procedure for calculating the hypothetical values of these parameters is proposed. With these parameters it is possible to obtain a time-dependent expression for the thixotropic areas, S(T). This procedure has been applied to the study of the thixotropic behavior of Aerosil 200 hydrogels at different concentrations. The comparative analysis of these systems has been realized by studying the relative thixotropic areas and relative thixotropic rates that are obtained from S(T).

Area Under Curve↗
PubMed1999

Diagnostic approach to patients with suspected pulmonary embolism: a report from the real world.

This study was carried out to examine the diagnostic approach to patients with suspected pulmonary embolism (PE) in a university hospital. A retrospective case record review of 251 patients with suspected pulmonary embolism was carried out according to a standard protocol, which looked at the utilisation of imaging techniques and compared clinical diagnoses with a standardised diagnosis established according to current recommendations. Isotopic lung scan was the most commonly used technique (73%), followed by leg vein sonography (36%) and contrast venography (31%). Lung arteriography was done in only 7% of patients. Among the 205 patients with a clinical diagnosis of PE, 115 (56%) would be diagnosed as having PE according to the standard criteria, 84 (41%) would be unclassified, and six (3%) would not be regarded as having PE. Among patients who were diagnosed as having PE and received anticoagulant therapy, 32% did not have the diagnosis confirmed by an imaging technique. Most of these had a non-diagnostic lung scan which, despite evidence to the contrary, seemed to be interpreted as confirmation of PE. We conclude that clinicians do not seem to follow current recommendations when approaching patients with suspected PE. In particular, there is an over-reliance on lung scans, and the significance of non-diagnostic scans was often misinterpreted. Arteriography was underused. These results emphasise the need to take measures to implement practice guidelines and to explore the usefulness of newer non-invasive techniques.

Anticoagulants↗
PubMed1998

[Agreement in the clinical diagnosis of pulmonary embolism].

BACKGROUND: The diagnosis of pulmonary embolism (PE) may be a difficult task. The diagnostic performance of imaging techniques is limited and pre-test probability of PE, estimated from basic clinical data, must be taken into consideration to interpret their results. The aim of this study was to evaluate the accuracy and agreement of clinicians in estimating PE probability. PATIENTS AND METHODS: We reviewed the charts of 116 patients admitted to hospital for suspected PE. Basic clinical data (symptoms and signs, arterial blood gases, chest X-ray and EKG) were extracted and given to five clinicians, who were asked to estimate the probability of PE. We determined the inter-clinician agreement and compared their estimates with the final diagnoses. RESULTS: Among patients with a final diagnosis of PE, clinical estimations of PE probability were: high in 63%, intermediate in 21%, and low in 16%. The accuracy of estimates varied between 67 and 80%. Actual PE prevalence was 81% among cases estimated as having high probability and 42% in those considered as low probability. The global inter-clinician agreement rates ranged from 56 to 72%, whereas the average kappa coefficient was 0.44. CONCLUSION: Basic clinical data seem to be more useful to predict PE than to exclude it. The accuracy and agreement between estimates from different clinicians are only moderate.

Humans↗
PubMed1998

Serum proteolytic activities and antiproteases in human colorectal carcinoma.

Some proteolytic enzymes, trypsin, cathepsin B, cathepsin D, collagenase, elastase and their inhibitors, API and AMG, in serum of patients with colorectal carcinoma have been evaluated. Twenty patients belonged to stage B of colorectal carcinoma, twenty two patients to stage D (Astler and Coller classification) and a control group of thirty healthy volunteers were evaluated. Except in cathepsin D, patients exhibit higher enzymatic activities than healthy subjects, and both groups have all the proteolytic activities assayed in serum. Patients with disseminated disease have increased cathepsin B and collagenase levels, with a decrease of trypsin activity, showing an increment in API and AMG in sera. However, only the API values were significantly higher in patients with metastases. The coexistence of proteolytic activities in human sera together with their inhibitors is considered as well as the origin of these, tumoral and/or reactive, increments. Cathepsin B levels are raised in colorectal neoplasms and contribute to the destruction of the extracellular matrix and the proliferation of tumoral cells. There is evidence that a relation between collagenase like activity and tumor invasiveness exists. Cathepsin B and collagenase increases agree with the tumoral mass. On the other hand, trypsin decrease in metastatic carcinoma is probably related to the increment of their inhibitors, API and AMG, acute phase reactant proteins.

Adult↗
PubMed1997

Thixotropy of highly viscous sodium (carboxymethyl)cellulose hydrogels.

A general method to quantify the thixotropic behavior of systems with very low thixotropy is proposed. The areas enclosed by the rheograms tau = f(gamma) must be fitted to functions with well-determined boundary conditions. From these equations the corresponding thixotropic areas are obtained, together with the theoretical area enclosed by the rheogram corresponding to the maximum rheodestruction. The proposed method is applied to high viscosity sodium (carboxymethyl)cellulose gels.

Carboxymethylcellulose Sodium↗
PubMed1995

Shear stress synergism index and relative thixotropic area.

Shear stress synergism index and relative thixotropic area are introduced as quantifiers of viscous synergism and comparative thixotropy. The utility of these terms is demonstrated by their application to microcrystalline cellulose-sodium carboxymethyl cellulose (MCC-NaCMC) hydrogel, a starch of different botanical origins hydrogels and their combinations.

Carboxymethylcellulose Sodium↗
PubMed1993

[Testicular seminoma manifested by carcinomatous neuropathy: an unusual presentation. Review of the literature].

Contribution of one patient with tetraparesic picture originated by a major sensory-motor neuropathy, due to paraneoplastic syndrome produced by a testicular seminoma. The patient underwent inguinal orchiectomy and radiotherapy, with favourable evolution of his neurological symptomatology. Review of the literature and confirmation of the extraordinary rarity of such clinical picture.

Adult↗
PubMed1989

[Programs of diabetological education: a basic tool in the treatment of diabetes mellitus].

To assess whether the programs of diabetologic education (PDE) are effective to improve metabolic control in diabetes mellitus, depending on their inclusion in an overall therapeutic program and on the setting where they are imparted (hospital versus primary care center, PCC), we evaluated the changes in the HbA1 values in 230 insulin-treated diabetic patients, after receiving a PDE in a PCC (group A; n = 88) or as hospital inpatients (group B; n = 72) or outpatients (group C; n = 50). The remaining 20 patients (group D) received the same PDE, but their treatment did not depend on our Unit. The initial mean HbA1 levels were significantly reduced 3, 6 and 9 months after the PDE in group A patients (10.6% vs 9.6%, p less than 0.05; vs 9.4%, p less than 0.02; vs 9.1%, p less than 0.01), in group B patients (10.0% vs 9.5%, p less than 0.05; vs 9.1%, p less than 0.05; vs 9.0%, p less than 0.05) and group C patients (10.1% vs 9.5%, p less than 0.05; vs 9.1%, p less than 0.02; vs 8.9, p less than 0.01); however, they did not significantly change in group D patients (10.3% vs 10.7%, vs 10.3%, and vs 10.0%). Mean HbA1 in months 3, 6 and 9 were not different between groups A, B and C, but they were lower (p less than 0.05) than in group D. Our results confirm that PDE and treatment are effective to improve metabolic control in diabetic patients, whereas diabetological education alone is not useful. The place where PDE is given is not determinant for its effectiveness.

Adult↗
PubMed1989

[Brucellosis at a tertiary hospital. Retrospective epidemiologic study of 166 cases].

The epidemiologic polls concerning 166 cases of brucellosis are retrospectively analyzed; the cases are registered by the Preventive Medicine Service of Miguel Servet Hospital for five years (1980-1985). Most of our cases are of recent evolution, although 55% began to give symptoms more of 2 weeks ago and 30% more of 1 month ago. A clear annual increase of the number of cases, fundamentally of the male sex and patients coming from the rural areas, is observed. The percentage of cases in men (73.5%) is almost three times as those in women (26.5%), and the most numerous groups are the 20-29 interval age group and olders above 60. There is a small percentage of people with a professional risk factor (30.1%), which rise, slightly, for the ones who told of contact with cattle (39.2%) and rose up to 53.6% for the ones who consumed non controlled dairy products. However, in 23% of men and 40.9% of women the existence of some risk factors was unknown.

Adolescent↗
PubMed1988

Hepatic fibrin-ring granulomas in visceral leishmaniasis.

Hepatic fibrin-ring granulomas and leishmania parasites were found in the liver biopsy specimens of 3 patients with prolonged fever and hepatosplenomegaly. It was recognition of the leishmanias in the liver biopsy specimen that prompted the diagnosis in all cases. There was no evidence of Q fever, Hodgkin's disease, cytomegalovirus hepatitis, or allopurinol treatment, which are the recognized causes of hepatic fibrin-ring granulomas. This report extends the range of etiologies of hepatic fibrin-ring granulomas. As a result, leishmaniasis should always be a consideration to the pathologist and the clinician in the differential diagnosis of fibrin-ring granulomas.

Aged↗
PubMed1988

[Dental fluorosis in San Luis Potosi and its solution alternatives (pilot study)].

A study exposing the situation affecting the population of San Luis Potosí in central México, caused by dental fluorosis. Findings point to the need of implementing devices capable of regulating the concentrations of Fluorine ion (generating the efficient prevention of dental cavity incidence), to maintain them at optimal levels and without deletereal effects.

Fluoridation↗
PubMed1980

Choroid plexus blood flow in the sheep.

Choroid plexus blood flow was measured in 29 adult female sheep using the radioactive microsphere technique. Basal blood flow, response to change in arterial carbon dioxide tension, and response to change in mean arterial blood pressure were determined. The results were compared to cerebral cortical blood flow values in the same sheep. Mean choroid plexus blood flow was 601 ml/100 g/min under basal conditions. Choroid plexus blood flow fell 31% with hypocarbia, a reduction comparable to that seen in cortex. With hypercarbia choroid plexus blood flow rose only 27% whereas cortical blood flow increased by 199%. Unlike cortical blood flow, choroid plexus blood flow fell significantly with pharmacogenic hypertension. The latter finding may reflect the absence of a blood-brain barrier in choroid plexus.

Animals↗