Oligomeric forms of potato spindle tuber viroid (PSTV) and of its complementary RNA are present in nuclei isolated from viroid-infected potato cells

Different oligomeric forms of PSTV are detected in nuclei isolated from PSTV-infected potato cells by means of molecular hybridization, using as probes synthetic oligodeoxyribonucleotides with sequence specificity for (+)PSTV and for (-)PSTV. In addition to several species of longer-than-unit-length (-)PSTV molecules, two oligomeric forms of (+)PSTV are detected, which correspond in size to RNA strands of approximately two and three times viroid unit-length. They must be considered as the precursors of the circular and linear (+)PSTV monomers accumulating in the cell nucleus.

Photoluminescent thermometry based on europium-activated calcium sulphide

A photoluminescent thermometer, based on the transient emission response of a europium-activated calcium sulphide phosphor, is described in detail. This optical thermometry system has special advantages for temperature measurements in microwave and RF fields and potential application in electromagnetically induced clinical hyperthermia. A laboratory system has been constructed which utilises a fibreoptic probe with external diameter 0.8 mm. A system temperature resolution of 0.1 degree C has been achieved in the range 37-47 degrees C.

Specifically primed synthesis in vitro of full-length DNA complementary to potato-spindle-tuber viroid

Potato spindle tuber viroid (PSTV) RNA is transcribed in vitro by reverse transcriptase into complementary DNA in the presence of synthetic oligodeoxyribonucleotides as primers. In the case of priming with the pentadecadeoxyribonucleotide d(T-T-C-T-T-T-T-T-T-C-T-T-T-T-C) complementary to PSTV RNA from nucleotides 49 to 63, specificity of transcription initiation allows rapid sequencing of part of the viroid genome using chain-terminating dideoxyribonucleoside triphosphates. The DNA transcripts obtained represent distinct molecular species with the largest product being a full-length copy of the viroid RNA template. Molecular hybridization with 32P-labeled complementary DNA detects sequence homologies among different viroid species.

Prenatal diagnosis of Lesch-Nyhan syndrome and some characteristics of hypoxanthine-guanine phosphoribosyltransferase and adenine phosphoribosyltransferase in human tissues and cultivated cells

Activities of phosphoribosyltransferase for hypoxanthine and adenine were investigated in erythrocytes and human tissues of fetuses and adults as well as in cultivated fibroblasts and amniotic fluid cells. Kinetic characteristics of these enzymes were also studied in patients with the Lesch-Nyhan syndrome and with partial deficiency for hypoxanthine phosphoribosyltransferase (HGPRTase), and their obligate heterozygotes. The affinity of HGPRTase for both substrates in partial deficiency decreased to 13 to 20% of normal and by a less degree in its heterozygotes (50 to 65% of normal). A slight decrease in the Km for phosphoribosylpyrophosphate was observed in the case of heterozygotes for the Lesch-Nyhan syndrome. Elevated erythrocytic adenine phosphoribosyltransferase (APRTase) activity was found in fetuses, patients with the Lesch-Nyhan syndrome or with partial deficiency, and in some heterozygotes as well. However, the Km of APRTase for hypoxanthine in these subjects was the same as that in the normal adults. The HGPRTase activity in liver increased almost 4 times during the developmental period, whereas the APRTase activity remained approximately the same. In fetal liver, the APRTase activity was almost two times higher than the HGPRTase activity, whereas in fetal brain the HGPRTase activity was higher. The Km of HGPRTase for hypoxanthine in cultivated cells and human tissues were similar to that in erythrocytes and leukocytes. On the other hand, the HGPRTase affinity for phosphoribosylpyrophosphate in these cells was cconsiderably larger than in erythrocytes or in leukocytes.

Characterization of a phosphoglycerate kinase deficiency variants not associated with hemolytic anemia

The properties of a variant phosphoglycerate kinase (PGK) found in a large German clan were examined. The normal and variant enzymes, isolated by affinity chromatography, have the same molecular weight, specific activity, substrate affinity, and nearly identical pH-optima. Using immunoinactivation and immunodiffusion, the same specific activity for both forms was again determined. Since the enzymatic activity in older and younger erythrocytes varied only slightly, and since the specific activity of the variant was normal, the variant seems to be stable in vivo. This suggests that the decreased enzyme content is due to a decreased synthesis rate. The variant PGK described here is distinctly different from the known PGK variants and has been designated as "PGK München."

Characteristics of galactokinase and galactose-1-phosphate uridyltransferase in cultivated fibroblasts and amniotic fluid cells

The kinetic characteristics of galactose-1-phosphate uridyltransferase and galactokinase in cultivated fibroblasts and amniotic fluid cells were investigated. The Km values of galactokinase for galactose at 2.0 mM ATP are 0.34 mM in amniotic fluid cells and 0.48 mM in fibroblasts. The Km values for ATP at 0.5 mM galactose are 1.25 mM and 2.10 mM. Transferase and galactokinase activities and protein content increase logarithmically during the growth of cultivated cells. The specific activity of both enzymes also increases and reaches a maximum level 10--15 days after subculture. The specific activity of transferase increases faster than that of galactokinase in the case of amniotic fluid cells. In the case of fibroblasts the specific activity of galactokinase increases faster than that of transferase.

Refined mapping of the gene for glutathione reductase on human chromosome 8

Activity of the enzyme glutathione reductase (EC 1.6.4.2) in erythrocytes and fibroblasts of a patient with karyotype 46, XY, del(8) (pter-p212:) was found to be in the normal range. With results from other laboratories, this allowed a more precise mapping of the gene for this enzyme in the region 8p2100-8p212.

[Prenatal diagnosis in pregnancies at advanced maternal age (author's transl)]

Among 113 prenatal diagnoses in pregnancies at advanced maternal age (mothers older than 37 years) 7 aberrant fetal karyotypes were found (6.2%). Detailed reports of one case of trisomy 21, 18 and 13 each, as well as of XXY-, XYY- and XXX gonosomal constitution respectively are presented in the following. The frequency and severity of chromosome aberrations occurring in fetuses from elder women are discussed with respect to data from the literature. It seems that this group bears a higher risk for chromosomally abnormal offspring than has been suggested before.