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W Rehpenning

Publications and source records attributed to W Rehpenning.

51 records · Page 3Linked to original sources

[Mathematical analysis of the error distributions in flow-systems and consequences for the determination of new method-specific control limits (author's transl)].

In connection with the determination of method adapted control limits for the Technicon Autoanalyzer SMA 12/60 (Na+, K+, C1-, Total Protein, Albumin, P, Cholesterol, Urea Nitrogen, Calcium, Creatinine, Bilirubin, Uric Acid) we have investigated the representation of the control variable error distributions by mathematical formulae. The application of orthogonal functions (Gram-Charlier's series type A) proved to be not practicable because of the oscillations occuring at the ends of the distributions. Considerably improved results were obtained by a modified expression of a Gram-Charlier's series of type C, although the tails of the distributions (which are particularly important for the calculation of the fractiles) could not be optimally approximated. However, a very satisfactory approximation of the empirical density functions was obtained when we interpreted the control variables as non-additive superposition of two or three normally distributed quantities with different variances. This enables us to calculate channel specific alarm and control limits, thereby replacing the conventional quality control parameters previously checked and based on the assumption of normal distributions. Thus, an adequate monitoring of the reliability of flow-systems can be achieved.

Autoanalysis↗

Determination of mRNA half-life in HeLa cultures by a poly(A)-independent direct analysis of specific radioactivity of mRNA.

mRNA specific radioactivity in HeLa cultures exposed to (3H)uridine (10 muM) was determined directly by a highly selective poly(A)-independent method which we have described previously. Neither uridine in mRNA nor UTP approached the specific radioactivity of the exogenous (3H)uridine, but attained steady-state specific radioactivities which remained a third below the value of the added precursor. Using the labeling data for the evaluation of mRNA turnover, previously described by Greenberg, mRNA half-life in exponentially growing HeLa cultures was found to be 0.87 times the cell doubling time. Decay curves of mRNA in prelabeled cultures were in accordance with these values (half-life equals 0.79 times the cell doubling time) when corrected for growth and also for "reutilization" which was accomplished by relating uridine labeling in mRNA to UTP specific radioactivity. The experiments showed that an exact evaluation of mRNA turnover is possible only when the following points are taken into account. a) A constant supply of exogenous labeled uridine must be provided to guarantee a constant specific radioactivity of UTP. b) Labeling of CTP and of cytidine in RNA are delayed when compared with UTP and uridine in RNA. Corrections for cytidine labeling in RNA are therefore required. c) As rRNA approached a definitely lower steady-state specific radioactivity than mRNA, mRNA specific radioactivities must be determined directly (i.e. by radioactivity and absorbance at 260 nm in isolated mRNA fractions) in order to evaluate true turnover of this RNA species.

Cell Count↗

[Liver function tests after a 6-month deposiston therapy].

18 women were treated with Deposition (4th, 11th and 18th cycle day each 1 mg 17alpha-Ethynyl-3isopropylsulfonyloxy-Estradiol, 25th cycle day 10 mg norethisterone acetate). When these medicines were taken the activities of aminotransferases, alkaline phosphatase and alpha-amylase, the contents cholesterol, total bilirubin and proteins of the serum and the paperelectric solution, TTT and indocyanine green half worth time. A little significant decrease of the activity of alaninamino-transferase (GPT) was to be stated. Whereas at the end of the 6th cycle the TTT as well as the contents of total proteins and albumin, showed a little significant decrease and the contents of alpha2-globulin, beta-globulin as well as cholesterol were statistically shown to grow. The indocyanine green elimation was longer at the end of the 6th cycle without any pathological worth from clinical point of view being proved.

Adult↗

Epidermal Langerhans cells and prognosis of patients with mycosis fungoides and Sezary syndrome.

Langerhans cells (LC) (CD1a-positive dendritic epidermal cells) have been proposed to favour the pathogenesis of mycosis fungoides (MF) and Sézary syndrome (SS). We therefore examined the influence of LC retrospectively on the survival of 35 patients. Two clinical parameters (age, stage of disease) were additionally evaluated. LC densities were morphometrically assessed on immunohistochemically stained cryostat sections of the respective diagnostic specimen. Death resulting from MF and SS was significantly (p = 0.003) less frequent in patients with CD1a-positive epidermal cell densities higher than 90 cells/mm2 (optimal break point) as compared with patients with lower numbers, independently of the stage of disease. This result suggests that LC have a significant impact on the prognosis of patients with MF and SS, playing an important role in the host defense mechanisms against these lymphomas.

Epidermal Cells↗