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Biomedical subjects

A Hansson

Publications and source records attributed to A Hansson.

At least 73 records · Page 4Linked to original sources

Unequal mitotic sister chromatid exchange and different length of Y chromosomes.

There is wide variation in the length of the Y chromosome. In the same individual the length varies continuously and is normally distributed. We describe a boy with borderline mental retardation, gross and fine motor coordination difficulty, muscle rigidity, ptosis, clinodactyly, and a Y chromosome of different lengths in two separate cell populations. The most probable explanation of the cytogenetic finding is a mitotic unequal sister chromatid exchange of the Y chromosome.

Adolescent↗

Gc serum groups in schizophrenia.

Gc subtypes were studied by isoelectric focusing in schizophrenic patients and controls. No significant differences between patients and controls were found. The results so far on Gc groups and schizophrenia show no consistent pattern and the significant associations reported have not been confirmed.

Blood Protein Electrophoresis↗

Characterization of calcium and phospholipid dependent protein kinase in isolated rat adipocytes.

Calcium and phospholipid-dependent protein kinase (protein kinase C) from isolated rat adipocytes has been partially purified using DEAE-Sepharose CL-6B and characterized. The enzyme was shown to have similar properties as the kinase isolated from brain or spleen. When histone was used as substrate, an equal amount of cAMP-dependent and calcium and phospholipid-dependent kinase activity was detected from the DEAE Sepharose CL-6B fractions. The major part of protein kinase C (72%) was isolated from the soluble adipocyte fraction. Of the membranous fractions, the plasma membrane exhibited the highest specific activity. The protein kinase preparations bound [3H]-phorbol-12,13-dibutyrate (PDBU) with high affinity (Kd = 2 nM) and the number of PDBU binding sites per cell was calculated to 63 000.

Adipose Tissue↗

Phorbol ester-induced alteration of differentiation and proliferation in human hematopoietic tumor cell lines: relationship to the presence and subcellular distribution of protein kinase C.

The intracellular translocation of protein kinase C (PKC) from the soluble to the membranous fraction has been shown previously to correlate with biological activity of phorbol esters in several systems. In this paper, we describe that PKC translocation was a general phenomenon in all PKC containing cell types when five 12-O-tetradecanoylphorbol-13-acetate (TPA) responsive and nonresponsive hematopoietic tumor cell lines were investigated. The nonresponsive cell line U-266 contained undetectable levels of PKC. The dose of TPA required for translocation was similar to the TPA concentration necessary to suppress erythroid differentiation in K-562 cells and to induce macrophage differentiation in U-937 cells, but 100-fold higher than that required for suppression of proliferation in K-562 and U-937 cells. By contrast, PKC translocation and TPA induced proliferation inhibition exhibited a similar dose dependence in a subline of U-937 (U-937 RES) adapted to growth in the presence of 10(-9) M TPA. It is suggested that U-937 RES is deficient in a TPA dependent but PKC independent signal pathway.

Biological Transport↗

Properdin factor B (Bf) types in schizophrenia.

The phenotype frequencies of properdin factor B (Bf) were studied in patients with (n = 47) and without (n = 66) a family history of schizophrenia and in controls. In patients with a family history of schizophrenia, a significant decrease of the FS type was found. No significant difference was found between patients without a family history of schizophrenia and controls.

Complement Factor B↗

Technique to examine human sperm chromosomes using zona-free hamster eggs.

In experiments with repeated semen samples from two donors, zona-free hamster eggs were used for activation of human spermatozoa to metaphase. When mean number of spermatozoa per penetrated egg was low (1.0-3.3) after insemination in vitro, further incubation resulted in activation of spermatozoa to metaphase. High sperm/egg ratios, 4.2 and 7.5, yielded no sperm chromosomes. The preincubation and insemination intervals necessary for low sperm/egg ratios were individual.

Animals↗

Catalytic properties of the liver microsomal hydroxylase system in reconstituted phospholipid vesicles.

Two types of cytochrome P-450, P-450LM2 and P-450LM3, have been purified from rabbit liver microsomes and incorporated into phospholipid vesicles by a cholate gel filtration technique together with purified preparations of NADPH-cytochrome P-450 reductase. The catalytic properties of the vesicles have been compared with a system reconstituted with small amounts of dilauroylphosphatidylcholine (DLPC). 6 beta-Hydroxylation of androstenedione proceeded at a rate 10 times higher in the vesicles compared to the DLPC-system. The kinetics for the reaction were the same in the vesicles as in intact microsomes i.e. sigmoidal substrate curves were obtained and Hill-coefficients of about 1.4 were calculated in these systems. In contrast, Michaelis-Menten kinetics were obtained for 6 beta-hydroxylation in the DLPC-system. The results could indicate cooperativity between different P-450 molecules in the intact membrane but not in the DLPC-system. P-450LM2-catalyzed 16-hydroxylation of androstenedione was in contrast to the situation with P-450LM3 inhibited in the vesicles as compared to the DLPC system. It is suggested that for evaluation of substrate specificity and other properties of different types of liver microsomal P-450, phospholipid vesicles may be a more relevant integration level than the DLPC-system.

Androstenedione↗

Liver injury following administration of 8-methoxypsoralen during PUVA therapy.

A case of liver injury caused by 8-methoxypsoralen given orally during PUVA therapy is presented. The reaction, manifested by elevated serum alanine-aminotransferase and serum aspartate-aminotransferase, was provoked on three consecutive occasions, on the last one with 8-MOP only. The liver injury seems to be of the hepatocellular and nonpredictable type.

Alanine Transaminase↗

The origin of the extra chromosome 21 in Down syndrome. Studies of fluorescent variants and satelite association in 26 informative families.

Studies of fluorescence and other chromosomal variants were informative in 26 out of 72 families. Maternal nondisjunction was found in 19 and paternal in 7 cases. Satellite association studies of these parents and 94 controls from the same age group showed a highly significant increase in the satellite association index (AI) for chromosome 21 in the parents where the nondisjunctional event had taken place. The AI was also higher for chromosome 14. In addition, the parents who produced the normal gametes had significantly higher AI's for some acrocentrics than the controls. Exogenous factors increasing satellite association cannot be ruled out. The number of 21-21 association was significantly increased in the parents with nondisjunction in meiosis 1. The results indicate that satellite association may play a role in the etiology of Down syndrome.

Child, Preschool↗

Translocation (13q21q). Four generation family study with analysis of satellite associations, fluorescent markers, and prenatal diagnosis.

A (13q21q) translocation was found in an infant with Down's syndrome. The 17-year-old mother and the grandmother carried the translocation 45,XX,t(13;21)(p12;q11). The great grandparents had normal karyotypes. Fluorescence marker studies suggested that the translocation originated in the great grandmother. The hypothesis was supported by satellite association studies which showed a significant excess of 13-21 and 13-15 associations in the great grandmother.

Amniocentesis↗