Wiener klinische Wochenschrift. Supplementum最新文献

With the introduction of an improved method for the determination of fructosamine a new tool is available for the monitoring of diabetes. This method provides a good reproducibility together with a standardized quality control and is easily applicated to automated clinical chemistry analyzers. Besides the analytical performance in general the impact of preanalysis on fructosamine values is important for routine work. In a study with 20 volunteers the impact of orthostasis has been investigated. Changes in fructosamine concentration correspond to a shift in the concentration of other analytical parameters related to serum proteins.

Reference ranges were evaluated for a new colorimetric method for the determination of fructosamine in serum. The reference group was composed of 1114 non-diabetics of both sexes including children. Reference values are only slightly affected by age and sex. In the course of childhood to adolescence fructosamine values raise and finally stabilize in adults. The small differences between both sexes have no effect on the interpretation of clinical results. Relating fructosamine values to albumin or total protein has little impact on the distribution of the values when protein values were within the reference range.

Fructosamine is thought to be an alternative diabetic long term parameter to HbAlc. A possible advantage of fructosamine is the shorter half life of this parameter. Therefore changes in the metabolic control of diabetes can be evaluated faster. However, daily variations of protein concentrations limit the clinical usefulness of fructosamine, especially in patients on hemodialysis, where we see variations in total protein- and albumin concentration during dialysis. Due to these limitations we studied the clinical usefulness of a new fructosamine assay in 38 patients with chronic renal failure. Fructosamine values, total protein, albumin, blood glucose and creatinine were measured before and after three hours hemodialysis treatment as well as glycosylated hemoglobin. Before dialysis HbA1c correlated with HbA1c after dialysis (r = 0.99), which documents the usefulness of glycosylated hemoglobin in patients on hemodialysis. Fructosamine before dialysis shows a correlation with fructosamine values after dialysis of r = 0.77. After correction with total protein the correlation was r = 0.95, also after correction with albumin. Fructosamine values before and after dialysis correlated excellently (r = 0.95). Fructosamine values before and after dialysis can only be compared after correction with total protein or with albumin.

Measurement of protein glycation (fructosamine) has become an accepted tool in diabetes diagnostics. Among different methods available, the serum fructosamine test published by Johnson and Baker in 1983 has gained wide acceptance due to a simple and easily automated assay procedure providing clinically meaningful results. A recent modification of the Nitroblue Tetrazolium (NBT) reagent, improved by addition of tensides and uricase, exhibits lower interference by lipaemia and urate. It is also less affected by the sample matrix and yields results closer to the physiological range of glycated proteins. Furthermore, a completely new standardization protocol was used in the preparation of calibration material. The new colorimetric method for the determination of fructosamine was evaluated in 12 European clinical laboratories.

Daily profiles of blood glucose, HbA1c, total protein and fructosamine were measured in 10 diabetic patients and the factor fructosamine x 7/g total protein was calculated. Measurements were done at 4 a.m. to be sure that the patients were sleeping for some time, during the day and the following evening at 11 p.m., when the patients were lying again, so that the influence of orthostasis, the difference between bed rest and walking could be demonstrated. The blood glucose profile was typical whereas the HbA1c concentration was very stable and constant. Total protein and fructosamine increased significantly by orthostasis; the correction of fructosamine by total protein diminished the differences, but did not completely eliminate the effect of orthostasis. However, fructosamine should be corrected by the total protein concentration in order to increase the diagnostic value of the parameter.

We have evaluated a new method for the determination of glycated serum proteins (fructosamines), which are elevated in diabetics. In accordance with earlier findings fructosamine depends not only on mean blood glucose but also on albumin- and total protein concentrations. Therefore fructosamine is not useful as an index of diabetic blood glucose control without consideration of an individuals albumin- or protein-concentration. We propose albumin- or protein-standardized fructosamines as new indices of diabetic control.

The dissatisfying results achieved in the therapy of ovarian carcinoma with an unchanging low rate (between 10% and 30%) of five-year-survival were the reason for efforts to develop a new treatment scheme combining chemotherapy with hormone therapy for epithelial ovarian carcinoma in FIGO stages III and IV. Basic theoretical and experimental reflections: Although in many cases patients may show good response to standard chemotherapy containing cisplatin, a large percentage (70% to 90%) suffers a relapse due to the fact that single tumour cells are resistant to chemotherapy. In order to counteract this resistance we developed a method of therapy (in accordance with the ideas of Coldman and Goldie) based on the sequential application of various non cross-resistant cytostatic agents. This new regimen, comprised of Doxorubicin, Cisplatin, Vincristine, Cyclophosphamide and Methotrexate (AP-VC-MTX), was compared to two standard types of chemotherapy (Doxorubicin/Cyclophosphamide or Doxorubicin/Cisplatin) in a prospective, randomised study. The AP-VC-MTX regimen showed equal therapeutical results but had a significantly lower level of nephrotoxicity and gastrointestinal toxicity than the combined Doxorubicin/Cisplatin therapy. As a result of these studies we chose the AP-VC-MTX method as standard therapy for patients suffering from advanced stage ovarian carcinoma. Hormone therapy was tested in numerous phase II studies on patients who had previously received cytostatics and was found to be an effective alternative. One of the substances that was most closely studied was Medroxyprogesterone acetate (MPA). Its therapeutic value was established in in vitro tests which showed direct cytotoxicity in ovarian carcinoma and is based on the theory that, on the one hand, the MPA is attached to the progesterone receptor and impairs growth in a similar way to endometrium and breast carcinoma and, on the other hand, the MPA reduces the level of gonadotropin and estrogen, which may be factors, which stimulate tumour growth in ovarian cancer. Furthermore, the myeloprotective effect and the corticoid-like effect of the MPA usually result in lower bone marrow toxicity and an increase in weight. 81 in vitro chemosensitivity tests carried out on tumour-cell cultures of 25 patients suffering from ovarian carcinoma, showed sensitivity to Cisplatin in 38%, Doxorubicin in 44%, 4-OOH-Cyclophosphamide (the in vitro active metabolite of Cyclophosphamide) in 50%, Vincristine in 53%, MTX in 19% and MPA in 36%.(ABSTRACT TRUNCATED AT 400 WORDS)

The concentrations of high molecular weight blood constituents are influenced by the increased intravascular pressure at sample collection. The impact on the fructosamine concentration was compared with that on total protein, plasma protein, electrolytes, and protein bound analytes such as calcium. The results show that fructosamine concentration behaves similar to that of total protein and albumin with change in resting position and venous-stasis.