Mothers'' postcounseling beliefs about the causes of their children''s genetic disorders.

Mothers' postcounseling beliefs about the causes of their children's genetic disorders were investigated by means of a Q-sort consisting of 54 statements of possible beliefs that were sorted into nine groups of six items each on the basis of congruence with the subject's beliefs. The subjects were well educated, knowledgeable about the genetics of their child's disorder, and indicated a high level of belief in genetic causes. Differences in beliefs were associated with differences in genetic etiology, indicating that beliefs were affected by the specific information provided in genetic counseling. Factor analysis identified a cluster of Q-sort items characterized by a highly personal relationship to the cause of the disorder (e.g., personal attributes, being selected and blessed, and God's actions). Subjects who rated these items low had a belief pattern, designated impersonal, that was consistent with a scientific worldview and that indicated psychological distancing from the cause of the child's disorder. Subjects who rated these items high, the personal belief pattern, had a mixture of scientific and nonscientific beliefs that indicated a sense of personal involvement in the cause of the child's disorder. Subjects with the two belief patterns were equally knowledgeable about the genetics of the disorder. Thus, the personal belief pattern did not appear to interfere with acceptance or understanding of the information provided in genetic counseling.     

Regional localization of the genes for human HEXB. PGK, GALA. HPRT, G6PD by somatic cell hybridization

Twenty independent man-mouse (Cl1D,LA/TK-, HPRT-) and man-hamster (CH,HPRT-) hybrids using female human cells with balanced reciprocal translocation XX,t(X;5)(q21;q11) were analyzed for human genes localized on chromosome 5 (HEXB), on chromosome X (PGK, GALA, HPRT, G6PD) and for the different chromosomes in relation with the balanced reciprocal translocation (chr.5, chr.5q-, chr.Xq+, chr.X). The different results obtained indicate that the genes for human markers HEXB, PGK are on Xq+, and that the genes for human markers GALA, G6PD are on 5q-. These data implicate finally the following localizations: HEXB on 5q11 leads to 5qter; PGK on Xq21 leads to Xpter; GALA, HPRT, G6PD on Xq21 leads to Xqter.     

Separation of dissociated thyroid follicular and parfollicular cells: association of serotonin binding protein with parafollicular cells

Parafollicular cells (PC) of the sheep thyroid gland are neural crest derivatives that synthesize and release the biogenic amine serotonin (5-HT) as well as the hormone calcitonin. The thyroid also contains a highly specific serotonin-binding protein (SBP). Separation of dissociated thyroid cells was done to study the cellular localization of SBP and to develop a means of isolating PC for study. Various methods were used to obtain an enriched and purified population of PC. Minced thyroid glands were enzymatically dissociated and the cells were layered on a Ficoll linear density gradient. Fractions obtained from the gradient were examined for cell number, viability, 5-HT concentration, SBP activity, and morphology by electron microscopy. One of the fractions was found to be enriched in PC. High levels of 5-HT and SBP were also found in this fraction, whereas these levels were low where the majority of cells were found. This PC-rich fraction, however, contained numerous follicular cells (FC); therefore, additional approaches to cell separation were used. FC can be stimulated in vitro with thyroid stimulating hormone (TSH) to become intensely phagocytic. When stimulated cells were incubated in the presence of silica microspheres, the FC engulfed the microspheres, which were toxic to them. PC did not become phagocytic and were unharmed by the microspheres. Suspended cells, after incubation with microspheres, were centrifuged on a discontinuous gradient, and a PC-rich fraction was obtained. Silica, however, interfered with analysis of SBP. Another method to take advantage of the phagocytic potential of FC was therefore used. TSH-stimulated cell suspensions were passed through a column of sepharose to which thyroglobulin had been coupled. Stimulated FC apparently adhered to the beads and were retained by the columns. Fractions eluting from the columns were greatly enriched with PC. These fractions contained high levels of 5-HT and SBP, and considerably reduced FC contamination was found by quantitative electron microscopy. It is concluded that SBP is localized to PC in the sheep thyroid. The idea that these cells resemble serotonergic neurons in their mechanisms of 5-HT storage is supported.     

The differential distribution of vasoactive intestinal polypeptide in the normal human female genital tract

Summary VIP-like immunoreactive material is present in the female reproductive tract, with a distinct pattern of distribution. The highest concentrations of extractable material and immunoreactive nerve fibres were found in the cervix and vagina. In the cervix these fibres were seen below the surface epithelium and around cervical glands as well as in association with blood vessels and smooth muscle bundles. In the vagina the nerve fibres were most abundant in the superficial regions of the lamina propria. Scattered fibres were also present in the rest of the uterus and in the fallopian tubes. Chromatographic evidence indicates that this VIP-like material is of a similar molecular size to that extracted from other organs. Possible roles for VIP in the regulation of myometrial activity and of cervical and vaginal dilation and secretion are proposed.     

Seed Vigour in Bean (Phaseolus vulgaris L. cv. Apollo) as Influenced by Temperature and Water Regime during Development and Maturation

Bean plants grown in a controlled temperature glasshouse athigh temperatures (33/28, 30/25, or 27/22 °C) during theperiod of seed development and maturation matured early andproduced small seeds. The seeds were of lower vigour than thosegrown at 21/16 or 18/13 °C. The detrimental effect of highmaturation temperatures was observed even on plants bearingwell-developed seeds (yellow, fleshy-pod stage). Seeds maturedat high temperatures were also more susceptible to deteriorationwith delay in harvest, and to mechanical damage. Heavy wateringof plants with seed ready to harvest caused a reduction in seedvigour. For optimum quality bean seed, it appears essentialthat the seed develops and matures at cool temperatures, ina dry environment.     

Purification of the chloroplastic valyl-tRNA synthetase from Euglena gracilis.

Euglena gracilis chloroplast valyl-tRNA synthetase was purified 990 fold to a specific activity of about 1100 units/mg protein, by a series of steps including ammonium sulfate precipitation and chromatography on hydroxyapatite, DEAE-cellulose, Blue Dextran — Sepharose and Sephadex G200. The enzyme gives a single band upon polyacrylamide gel electrophoresis, appears to be a monomer with a molecular weight of 126,000 daltons and has Km values of 1.5 × 10^?5 M for L-valine, 5 × 10^?5 M for ATP, and 6 × 10^?8 for tRNA^Val.     

Establishment of rat pancreatic endocrine cell lines by infection with simian virus 40.

The feasibility of infection and transformation by SV40 (simian virus 40) of primary cell cultures derived from newborn-rat pancreas was investigated. As judged by the presence of intranuclear SV40 T-antigen, exposure to the virus resulted specifically in infection and transformation of epithelioid (predominantly endocrine) cells. The transformed cells were subcultured (more than 64 passages) and cloned. Culture medium and acid/ethanol extracts of the cells did not contain detectable amounts of immunoreactive insulin after the third subculture. However, inoculation of such SV40-transformed pancreatic cells into immunodeficient rats results in tumours in which insulin production was partially restored through the passage in vivo, since the tumour cells contained and synthesized small amounts of immunoreactive insulin which co-migrated with an insulin marker on gel chromatography. Interestingly, the transformed cells maintained under tissue-culture conditions produced a protein immunologically related to insulin, soluble in aqueous buffer but insoluble in acid/ethanol. This 3000-dalton protein is too large to be a translation product of the rat preproinsulin 9S mRNA. SV40-transformed pancreatic cells might prove useful in the investigation of the factors controlling and maintaining insulin biosynthesis.     

Fluorescence-microscopical demonstration of a population of gastro-intestinal nerve fibres with a selective affinity for Quinacrine

Summary A population of nerve fibres in the gastro-intestinal tract of mice showing a high affinity for quinacrine was revealed by fluorescence microscopy. Similar results were obtained in rats and guinea pigs. Whole-mounts of sheets of the smooth muscle layer following incubation in 10^-6-10^-7 M quinacrine for 15–60 min revealed fine fluorescent varicose nerve fibers in the myenteric plexus of Auerbach both around nerve cell bodies and in the interconnecting strands. Many fibers were also present between the strands of the plexus, especially running parallel to the circular muscle layer. Such fibers were not seen in similarly quinacrine-incubated irides. A proportion of the cell bodies in Auerbach's plexus also showed quinacrine accumulation. These cells were apparently smaller neurons, sometimes with fluorescent processes. Intraperitoneal injections of quinacrine failed to demonstrate nerve fibers, but some cell bodies in Auerbach's plexus were positive. Subsequent paraformaldehyde treatment for monoamine visualization showed persistent adrenergic nerve terminals in the intestine and iris. These nerves seemed to be fewer and had a more yellow fluorescence than normally. The identity of the quinacrine-positive fibers is discussed with respect to recent suggestions that purinergic, substance P, enkephalin, and somatosin-containing nerves, in addition to adrenergic and cholinergic nerves, are present in the gut wall.Supported by the Swedish Medical Research Council (04X-03185). Magnus Bergvalls Stiftelse and Karolinska Institutets Fonder. For generous gifts of Mepacrine we thank Winthrop, Skärholmen, Stockholm, Sweden. The skilful technical assistance of Miss Gerd Boetius and Miss Maud Eriksson is gratefully acknowledged