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Biomedical subjects

C Hansen

Publications and source records attributed to C Hansen.

194 records · Page 11Linked to original sources
PubMedDate not supplied

Studies on electrolyte and trace metal metabolism applying stable isotopes as tracers.

Tracer-kinetic investigations provide a useful tool for the assessment of body composition regarding electrolytes and trace elements. This paper demonstrates the feasibility of stable isotopes as tracers in studies on calcium and iron metabolism in risk groups like children. By applying both radioisotopes and stable isotopes simultaneously, in adults, a good intra-individual agreement was obtained for the derived figures of intestinal absorption. Using only stable isotopes, intestinal calcium absorption in children with renal failure was found to follow a similar pattern to that in adult patients.

Adult↗
PubMedDate not supplied

Calcium kinetic investigations and their clinical use.

Pool sizes and internal fluxes of minerals can be quantitatively determined by tracer-kinetic investigations and compartmental analysis. Investigations performed in 252 patients revealed characteristic patterns for calcium pools and fluxes with respect to disease. The method provides a useful diagnostic tool in the early detection of metabolic bone disorders and in problems of differential diagnostics.

Bone Diseases, Metabolic↗
PubMedDate not supplied

Hospital charges for antibiotics.

Hospital charges for intravenous antibiotics were obtained in a survey of 71 hospitals in 25 U.S. cities. Only 56.3% of the hospitals used their actual drug acquisition cost to calculate patient charges; the remainder used a base price derived from one of the wholesale price guides, which often seriously overstate the cost of antibiotics. Sixty-eight percent added a markup, averaging 134.5%, and 63.4% added a dispensing fee, averaging $5.47. A relatively high-dose, single-antibiotic regimen costs patients $50-$150 per day, independent of dose-preparation charges (average, $9.09 per dose) for a piggyback-type system or intravenous line-related charges. Antibiotics were least expensive in large hospitals and in those located in the northeastern United States. Charges for antibiotics are often inconsistently calculated, vary enormously among hospitals, and may be unfair to patients and confusing to physicians. Cost-conscious prescribing of antibiotics by physicians would be facilitated by a more consistent relationship between charges and true costs.

Anti-Bacterial Agents↗
PubMedDate not supplied

Ferrokinetic studies with stable isotopes as tracers.

A methodology for ferrokinetic studies based on the administration of iron stable isotopes was developed. Fractional plasma clearance and intestinal iron absorption in rabbits were determined using the double tracer technique. Three rabbits were given 58Fe solution intravenously and about 40 min later 57Fe solution orally. Blood samples were drawn at different times following administration. The analysis of the single iron isotopes content in plasma samples was made by proton nuclear activation. The results were compared with those obtained from the administration, to the same rabbits, of the radioactive isotopes 55Fe and 59Fe. The agreement was found to be satisfactory.

Animals↗
PubMedDate not supplied

An iron metabolism study in humans by means of stable tracers.

An investigation of iron metabolism in a female patient volunteer by administration of stable iron isotopes as tracers was performed. The applied methodology had already been tested in rabbits in comparison with radioactive tracer technique. The subject under study was given 58Fe solution intravenously and about 45 min later 57Fe solution orally. Ten blood samples were drawn at different times within 522 min from injection. Single iron isotopes content in plasma samples was determined by proton nuclear activation. A Compton suppressor system was utilized to improve the detector limits. The characteristic parameters of iron plasma clearance and of iron intestinal absorption were determined.

Activation Analysis↗
PubMedDate not supplied

Molybdenum metabolism studied by means of stable tracers.

An investigation on molybdenum metabolism by administration of molybdenum stable isotopes was performed. Fractional intestinal absorption was determined in animals by the double tracer technique. The investigated subjects were given an enriched solution of Mo-96 orally and, a few minutes later, an enriched solution of Mo-95 intravenously. Blood samples were drawn at different times following the tracer administration. The Mo-95 and Mo-96 contents in plasma samples were determined by proton nuclear activation. The described methodology offers a means for the study of molybdenum metabolism in humans without radiation risk.

Administration, Oral↗
PubMedDate not supplied

Identity of non-malignant human urothelial cell lines classified as transformation grade I (TGrI) and II (TGrII).

Restriction fragment length polymorphism (RFLP) and marker chromosome or isozyme analysis were used to study the identity of 7 human urothelial cell lines selected according to their HLA-A,B phenotype. The results confirmed that the cell lines Hu961b, Hu1125, Hu1694, Hu1752, Hu609 and HCV-29 were genuine cell lines of different origin, while Hu1734 and HCV-29 were of the same origin. Hu609 was recorded to be derived from a female. However, the presence of a Y chromosome indicated either false labelling or cross-contamination. Analysis of a series of frozen stocks of Hu609 cultures showed that "malignant transformation" of these cultures was due to cross-contamination.

Cell Line↗
PubMedDate not supplied

Glycosaminoglycans in autoimmunity.

Alteration of the distribution pattern and composition of glycosaminoglycans (GAG) and proteoglycans may play an important role in the development of autoimmune diseases. Recent experiments indicate that anti-DNA antibodies cross-reacting with hyaluronic acid, heparan sulphate and chondroitin sulphate are present in patients with systemic lupus erythematosus. Furthermore, elevated hyaluronic acid antibody levels correlating with the disease score have been found in the sera of patients with autoimmune thyroid disease in comparison to controls. In vitro, T lymphocytes from patients with this disease increased the production of hyaluronic acid by cultured human retro-orbital fibroblasts. Fibroblast stimulation, as well as elevated collagen and GAG production, could be shown in chicken cell lines which spontaneously develop an autoimmune syndrome analogous to human scleroderma. To analyse the structure and distribution pattern of different GAG compounds in the tissues and body fluids of patients with autoimmune diseases a highly specific HPLC method was developed, which revealed increased urinary chondroitin sulphate and dermatan sulphate concentrations in patients with autoimmune thyroid disease in comparison to controls, concentrations which were positively correlated with disease severity and disease activity. Furthermore, the renal GAG excretion in patients with autoimmune diabetes mellitus was studied, and markedly higher excretion in patients compared to healthy controls was found, which was correlated with the duration of the disease and diabetic late complications. Thus, GAG polysaccharides not only appear to play a major role in the pathogenesis of autoimmune diseases, but have been successfully introduced as an activity marker of the disease.

Animals↗
PubMedDate not supplied

TSH receptor in endocrine autoimmunity.

OBJECTIVE: The human thyrotropin receptor (hTSHR) is a potential common antigen in endocrine autoimmunity. Recently, some studies demonstrated transcripts for hTSHR or its components in the extrathyroidal tissue of patients with autoimmune thyroid disease (ATD), although others were unable to confirm these findings. In the present study we investigated orbital adipose/connective and muscle tissue as well as primary cell cultures of orbital fibroblasts and myoblasts from patients with thyroid and eye disease. METHODS: The messenger ribonucleic acid (mRNA) of hTSHR was reverse transcribed and amplified by polymerase chain reaction (PCR). To evaluate the existence of a functional hTSHR in cultured orbital fibroblasts and muscle cells, the TSH-mediated metabolic activity of the cells was measured by tetrazolium assay. RESULTS: We were unable to amplify the extracellular domain of hTSHR regardless of the material used. In contrast, transcripts of the transmembrane and intracellular domain of hTSHR were detectable in both crude retrobulbar tissue and primary cells cultures. The results of fibroblast amplification experiments were more successful than those with myoblasts. Furthermore, we were able to confirm that these transcripts of hTSHR can also be detected in the retro-ocular tissue of healthy persons. Independently of the TSH activity employed, no stimulation of fibroblasts or myoblasts was detected, even at higher TSH levels. CONCLUSION: These data do not suggest that hTSHR is expressed in a functional form in orbital tissue. However, a part of the receptor could play a role in the pathogenesis of autoimmune eye disease as a non-functional but antigenic protein. Whether a common antigen in the thyroid and orbit is related to hTSHR has not been clarified yet.

Adult↗