Trace elements in diabetes mellitus. Peculiarities and clinical validity of determinations in blood cells.

Significantly more information about trace element status can be obtained by investigating concentrations in blood cells instead of only evaluating the concentrations in plasma. This can be explained by the fact that essential trace elements such as zinc, copper, chromium and selenium take part in a variety of enzymatic processes on a molecular cellular level. Ignoring these important biochemical roles, trace element concentrations determined in whole blood or plasma very often lead to conclusions contrary to the actual intracellular concentration.

Serial transplants of DMBA-induced mammary tumors in Fischer rats as a model system for human breast cancer. VI. The role of different forms of tumor-associated stress for the regulation of pineal melatonin secretion.

Previous studies on human breast cancer patients showed a decline in circulating melatonin levels corresponding to primary tumor growth and an increase when relapse occurred. The aim of the current investigation was to study in an experimental model possible mechanisms involved. Inbred female F344 Fischer rats were used for serial passages derived from a chemically induced mammary adenocarcinoma.

Concepts for a model of good medical laboratory services.

Several international standards and corresponding interpretation documents for quality management systems have been published. Although these standards are found useful to some extent, they are considered to be insufficient in several areas important for medical laboratories particularly in the pre- and post-examinational phases. The normative document for accreditation of laboratories (ISO/IEC Guide 25) is presently being revised and a document for medical laboratories (ISO/TC 212, CD 15189) is at draft stage.

Reference values for the trace elements copper, manganese, selenium, and zinc in the serum/plasma of children, adolescents, and adults.

Up to now few plasma or serum reference or serum reference values have been available for the assessment of the essential trace element supply status in different age groups covering the whole range of life range. In the present investigation, the concentrations of copper, manganese, selenium, and zinc were determined in the serum of 137 healthy children and in the plasma of 68 blood-donors. The age distribution within these groups ranged from 1 month to 18 years and from 22 to 75 years.

Isolation of corpuscular components of whole blood for the determination of selenium in blood cells.

Currently, the determination of trace elements in plasma or whole blood for the evaluation of adequate supply is unsatisfactory as it does not reflect exactly the biochemical processes in the human organism. A method of isolating cell fractions was developed in order to be able to analyze these elements in the corpuscular components of the blood. The separation, which is simple to perform, makes possible a high yield of erythrocytes, thrombocytes, and polymorphnuclear and mononuclear leucocytes, as well as a high purity of the cell fractions.

Determination of the trace elements zinc, copper, nickel and chromium in bone marrow and plasma of patients with non-Hodgkin lymphomas.

The concentrations of zinc, copper, nickel and chromium were determined in bone marrow and plasma of 37 patients suffering from non-Hodgkin-lymphomas (NHL). The results were compared with a control group of 10 patients with negative histopathologic results in bone marrow. The results demonstrate that all patients with low grade and high grade NHL have elevated trace element levels in bone marrow compared to the control group.

Chromatographic separation of serum proteins and estimation of their zinc and copper content.

Human serum proteins of blood donors and dialysis patients were separated by means of gel filtration chromatography. The resulting fractions were analyzed for copper and zinc. Separation resulted in 3 zinc peaks with a molecular weight of about 700,000, 300,000, and 75,000 Dalton, with alpha 2-macroglobulin co-eluting in the first and albumin co-eluting in the third zinc peak.

Post-transcriptional modification of serum creatine kinase in infected intensive care patients.

Low creatine kinase (CK) activities in serum are associated with high fatality rates in intensive care patients. The underlying mechanisms for this phenomenon were investigated. No correlation was found with other biochemical markers of inflammation (CRP, alpha-1 acid glycoprotein, alpha-2 macroglobulin).

Multivariate calibration for assays in clinical chemistry using attenuated total reflection infrared spectra of human blood plasma.

A spectral analysis of human blood plasma was undertaken by use of a Fourier-transform infrared spectrometer with a circular attenuated total reflection cell. The concentrations of total protein, glucose, triglycerides, total cholesterol, urea, and uric acid were measured by chemical or enzymatic methods. For these constituents the partial least-squares (PLS) algorithm was used for a multivariate calibration including the infrared fingerprint region of the plasma spectra.

Multivariate determination of glucose in whole blood by attenuated total reflection infrared spectroscopy.

A spectral analysis of whole EDTA blood was undertaken by using attenuated total reflection and Fourier-transform infrared spectroscopy. The concentration of blood glucose was measured by an enzymatic method using glucose dehydrogenase and ranged between 40 and 290 mg/dL with an average concentration of 90.4 mg/dL.

The significance of zinc for humoral and cellular immunity.

Zinc performs a number of unique functions in immunology, which distinguish it from all other trace elements. This special role is based upon its properties as a catalyst of a larger number of enzyme-controlled metabolic processes. Zinc supports, it even enhances, humoral and cell-mediated immunity by facilitating proliferative reactions to stimulus by different mitogens.

Reference ranges for alpha-amylase in serum and urine with 4,6-ethylidene-(G7)-1-4-nitrophenyl-(G1)-alpha,D-maltoheptaoside as substrate.

Reference ranges for alpha-amylase in serum, spontaneously voided urine, and 24 h urine were determined, using 4,6-ethylidene-(G7)-1-4-nitrophenyl-(Gl)-alpha,D-maltoheptaoside as the substrate (EPS method), at 25, 30, and 37 degrees C. The measured values were evaluated with and without the use of a factor which converts the results of the alpha-amylase EPS method into values comparable to those obtained with the alpha-amylase PNP method (substrate: 4-nitrophenyl-alpha,D-maltoheptaoside); comparison with the established reference ranges of the PNP method was therefore possible. The values for urine sometimes deviated markedly from the PNP reference ranges, but the values for serum showed close agreement.

Evaluation of a new alpha-amylase assay using 4.6-ethylidene-(G7)-1-4-nitrophenyl-(G1)-alpha-D-maltoheptaoside as substrate.

The determination of alpha-amylase activity using an ethylidene-blocked 4-nitrophenyl-maltoheptaoside (EPS) has been evaluated in five laboratories on eight different analysers at 25 degrees C, 30 degrees C and 37 degrees C. The protecting ethylidene group inhibits hydrolysis at the non-reducing end of the substrate molecule by the auxiliary enzyme, alpha-glucosidase. The combined reagent is therefore stable for at least 10 days at 2-8 degrees C.

Measurement of activation energy of gamma-glutamyltransferase as a marker for enzyme heterogeneity.

In order to detect differences between various multiple forms of gamma-glutamyltransferase, the activation energy was measured. In the serum of patients with liver diseases, activation energy was measured. In the serum of patients with liver diseases, activation energy of the serum enzyme is higher than in normal individuals (41.

Physicochemical determinations of glucose in vivo.

Conventional methods for the determination of blood glucose are not suitable for application in vivo. It is therefore necessary to seek other methods for monitoring blood glucose as a controlled variable of pancreatic hormonal regulation. Physical methods are preferable to conventional chemical methods, because the chosen methods should not consume or chemically modify glucose.

Ion-selective potentiometry in clinical chemistry. A review.

Ion-selective potentiometry is used more and more in clinical medicine for the determination of electrolytes in various body fluids. With regard to K+, Na+, Ca2+ and Cl- this technique has almost completely displaced flame photometry, atomic absorption spectrophotometry and coulometry. Moreover, reliable automated devices have facilitated routine analyses.

[Arterial hypertension in renin-producing retroperitoneal leiomyosarcoma].

A case report of an extrarenal retroperitoneal metastatic leiomyosarcoma with associated paraneoplastic renin production is presented. Due to the renin excess syndrome, accelerated hypertension was present combined with the signs of secondary hyperaldosteronism, hypokalemia, and alkalosis. In contrast to other publications of extrarenal malignoma with paraneoplastic renin activity, this case elucidates a histologically close relationship to epitheloid muscle cells of kidney vasa afferentia and derived benign tumors.

[Specimen carriers for blood sugar determinations].

The use of boric acid-impregnated filter paper has proven to be a useful and reliable means of absorbing capillary blood samples for determining glucose concentration. In this method a circular piece of filter paper (6.36 mm radius) infiltrated with the blood sample is punched out with a commercially available punch, glucose is eluted from the filter paper with a haemolyzing solution and subsequently glucose concentration determined by whatever method is available.