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Biomedical subjects

M Hens

Publications and source records attributed to M Hens.

7 recordsLinked to original sources
PubMed2001

Functional characterization of colloidal phosphorus species in the soil solution of sandy soils.

The impact of mobile colloids on the transport of phosphorus in the subsurface environment is not well understood. We hypothesized that interactions between metals, organic matter, and P control the dynamics of mobile colloidal P species in excessively fertilized sandy soils. The effect of UV irradiation and additions of 32P, orthophosphate, Fe, Al, and NaF on the concentration of colloidal P was examined using gel filtration chromatography. In addition, molybdate unreactive P (MUP) was characterized using phosphomonoesterase assays. The high molecular mass reactive P (HMMRP) fraction did not react to orthophosphate additions, increased upon Al and Fe additions and decreased upon NaF addition and UV irradiation. These results support the hypothesis that HMMRP is present as organic matter-metal-orthophosphate complexes. The concentration of high molecular mass unreactive P (HMMUP) decreased upon UV irradiation. The MUP concentration slightly decreased upon incubation with phytase and acid phosphatase. These observations fitted well to the "protection" hypothesis, where hydrolyzable P bonds are protected from monoesterase attack through occlusion in colloidal material. Taken together, this study indicates the high potential for subsurface P loss by colloidal particles in soils excessively fertilized with animal manure.

Agriculture↗
PubMed1997

Thromboembolism prophylaxis in chronic atrial fibrillation. Practice patterns in community and tertiary-care hospitals.

BACKGROUND AND PURPOSE: By 1992, several prospective trials established the efficacy of anticoagulation (AC) and to some extent antiplatelet (AP) agents in the prevention of stroke in the setting of atrial fibrillation (AF). The objective of this study was to determine whether practice patterns in AF stroke prophylaxis reflect the findings of clinical trials and whether stroke prophylaxis in AF differs between community hospitals and tertiary teaching hospitals. METHODS: Retrospectively, 1250 hospital charts were reviewed. After patients who had undergone recent surgery, received treatment for malignancy, or were not in chronic AF on discharge were eliminated, 651 remaining records were analyzed for the presence of 26 clinical factors influencing the selection of thromboembolism prophylaxis. Descriptive statistics and logistic regression were used to analyze the association between clinical and demographic factors and the decision to treat with AC, AP, or no specific antiembolic therapy. RESULTS: Of the 651 patients in AF, 273 (42%) received noemboli prophylaxis while 219 (34%) were treated with AC (warfarin), 146 (22%) were treated with AP, and 13 (2%) received both agents. Patients discharged in AF from community hospitals were significantly less likely to be treated with either AC or AP agents than patients discharged from tertiary centers. A strong bias against thromboembolism prophylaxis with either AC or AP agents in AF existed with age over 45 years. Multivariate logistic regression indicated that the decision to treat was associated only with the presence of prosthetic valve, history of prior stroke, mitral disease, and absence of a recent gastrointestinal bleed or occult blood in stool. Even after adjustment for these factors, a significant bias against treatment with either AC or AP agents with advancing age and discharge from community hospitals remained. CONCLUSIONS: Thromboembolism prophylaxis with either AC or AP agents is underutilized in the setting of AF. Furthermore, factors known to increase the risk of embolization in AF such as age, hypertension, diabetes, and heart disease were not associated with decisions to treat with either AP or AC agents. This study suggests that the use of clinical guidelines suggested by trials of thromboembolism prophylaxis in AF could reduce the incidence of stroke.

Aged↗
PubMed1993

Multiple sclerosis: a literature review.

The pathology of multiple sclerosis (MS) was first described over 150 years ago. An estimated 250,000 to 350,000 people are affected with MS in this country. Young adults between the ages of 20 and 50 years are most commonly affected, with the majority of patients experiencing a relapsing course and progressive functional disability. To date, researchers have been unable to discover a precipitating cause. However, many now believe MS develops due to exposure to some unknown virus in a genetically predisposed individual. The incidence of disease is limited in temperate climates and higher in northern latitudes. Neuroscience nurses frequently care for individuals with MS and must, therefore, maintain a familiarity with the current literature and research.

Cause of Death↗
PubMed1985

Alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase and creatine kinase in bronchial aspirate from neoplastic and normal pulmonary tissue.

The activities of 4 enzymes, i.e. alkaline phosphatase, gamma-glutamyl transferase, lactate dehydrogenase and creatine kinase were studied in bronchial aspirates and serums from two groups of subjects, the first one was composed of 14 subjects without active bronchopulmonary pathology and the other of 20 patients with lung cancer. The results showed a statistically significant decrease of the activities of alkaline phosphatase and beta-glutamyl transferase in bronchial aspirate from patients with bronchogenic malignant tumors in relation to normal subjects. This finding could be explained by the 'fetalism' principle, which states that the quantitative pattern of enzymes of immature human tissues resembles those of neoplastic tissues.

Adolescent↗