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I Gustavsson

Publications and source records attributed to I Gustavsson.

At least 91 records · Page 5Linked to original sources
PubMed1987

The nature of the 1;29 translocation in cattle as revealed by synaptonemal complex analysis using electron microscopy.

Synaptonemal complex analyses were carried out by electron microscopy on surface-spread spermatocytes of one normal bull and two bulls that were heterozygous for the so-called 1;29 translocation. The autosomal bivalents of the normal karyotype, which could be arranged by size in a series, demonstrated kinetochores at the terminally located attachment plaques. One autosomal bivalent was clearly larger than the rest and apparently consisted of the long arm of the 1;29 translocation. The 1;29 translocation was the longest autosome in the set and had a kinetochore in a subtelocentric position. Some of the autosome pairs had nucleolus organizer regions in telomeric regions. The X and Y chromosomes, which were not paired at zygotene, demonstrated association in a very short segment at early pachytene; in no cells could a synaptonemal complex be seen between the X and Y. Very often the sex chromosomes were dissociated. At zygotene, a few, usually large, bivalents were unpaired proximally. This always also involved the proximal parts of the arms of the 1;29 translocation and their normal homologs. At early pachytene, the 1;29 trivalent, although to a less extensive degree, was also unpaired in the pericentric region. Configurations in which one chromosome, either 1 or 29, was completely paired with its corresponding arm in the 1;29 translocation chromosome also occurred. When unpaired proximally, the size of chromosome 1 agreed fairly well with the size of its corresponding arm, but the size of chromosome 29 was considerably larger than the corresponding arm of the 1;29 translocation chromosome. During late zygotene and early pachytene, the percent difference between chromosome 29 and its corresponding arm decreased, and at mid and late pachytene there had been a complete synaptic adjustment. The size difference and pairing behavior indicated that a deletion of the kinetochore and the most proximal segment of chromosome 29 had preceded the fusion with chromosome 1 into the 1;29 translocation. The unique structural appearance of the 1;29 translocation chromosome compared to that of other centric fusion translocations in cattle lends support to the theory of a monophyletic origin of the 1;29 translocation. The importance of the pairing behavior observed in governing recombination and chromosome disjunction is briefly discussed.

Animals↗
PubMed1986

Further data on chromosomal assignments of pig enzyme loci LDHA, LDHB, MPI, PEPB and PGM1, using somatic cell hybrids.

Clear interspecies differentiation between the chromosomes in pig-mouse somatic cell hybrids was achieved by using the THA-technique for the cytogenetic analysis. The assignments of LDHB and MPI to pig chromosomes nos 5 and 7 respectively, reported previously, were confirmed by analysis of 34 hybrid clones. The LDHA, PEPB and PGM1 genes were assigned to pig chromosomes nos 2, 5 and 6 respectively. Both LDHB and PEPB were indicated to be located on the long arm, except the most proximal part, of pig chromosome no. 5. The proposed synteny between LDHB and PEPB in pigs is in accordance with the synteny observed between these two loci in several other mammalian species.

Aminopeptidases↗
PubMed1983

Determination of mercury in freeze-dried muscle samples of pike, cod and perch using an ASV-technique.

Determination of mercury in fish muscle samples can be made by an anodic stripping voltammetric technique (ASV) using a gold disc as the working electrode. Prior to analysis deep-frozen fish were thawed and then dissected using quartz scalpels. The freeze-dried samples were homogenised by the brittle fracture technique. Two wet digestion procedures were investigated, namely the HNO3/HCIO4 and the HNO3/H2SO4 system, and both were found to be useful. In order to complete the oxidation, the sample had to be UV-irradiated. The stripping procedure can be done in either a new medium - 0.1 M HCIO4 and 2.5 mM HCl - or directly in the sample solution. Using HNO3 and H2SO4 as oxidising agents and subsequently stripping the mercury directly in the sample solution is recommended, as the analytical procedure will be simpler and more time-saving. The concentrations obtained for pike, cod and perch, caught at a near-shore Baltic Sea station off the Forsmark nuclear power plant in Sweden, were 19.6, 0.84 and 5.1 (micrograms/g dry weight), respectively. On comparison with results obtained from neutron activation analysis, good agreement was found.

Animals↗
PubMed1983

Comparison of urinary and plasma catecholamine responses to mental stress.

8 subjects were exposed to the Stroop mental performance test in a design with alternating hourly periods of rest and stress. During each period one urine sample and several venous plasma samples were obtained. Heart rate responded rapidly to initiation and termination of the stress exposure with increases and decreases respectively. Both urinary and plasma adrenaline increased significantly during stress. The plasma response was immediate and sustained. Neither urinary, nor plasma noradrenaline were significantly increased by the test. Plasma noradrenaline, however, increased significantly on termination of the exposure to stress. It was suggested that the latter effect may be due to muscle sympathetic nerve activity decreasing during stress and increasing following stress. The sample-to-sample variation was more than 20% of the mean for both catecholamines, indicating the need for frequent sampling to reliably reflect plasma levels. The mean intraindividual plasma/urine correlation was r = 0.70 (p less than 0.001) for adrenaline and r = 0.40 (p less than 0.05) for noradrenaline. When only resting periods were considered, no significant correlations remained, apparently due to a reduced range of variation and accompanying reduced signal-to-noise ratio. It is concluded that both urinary and plasma adrenaline may be useful in the evaluation of changes in sympatho-adrenal activity during stress.

Adult↗