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Biomedical subjects

J Nielsen

Publications and source records attributed to J Nielsen.

At least 433 records · Page 24Linked to original sources
PubMed1982

Incidence of chromosome abnormalities in newborn children. Comparison between incidences in 1969-1974 and 1980-1982 in the same area.

As part of an ongoing study of the influence of environmental factors on pregnancy, childbirth, and fetuses, comparisons have been made between incidences in 1969-1974 and in 1980-1982 of chromosome aberrations in liveborn children in the same area of Denmark. The incidence of chromosome aberrations in the first period was 2.6 per 1000, compared with 41. per 1000 during the latter period. However, the difference was mainly due to an increase in inversions, and this in turn was due to a difference in chromosome staining methods between the two periods. It is concluded that the Danish study and similar studies in the United States, Canada, and Scotland indicate that early detection of chromosome aberrations by chromosome examination at birth is indicated in order to be able to inform and counsel parents of children with chromosome aberrations. Chromosome examination at birth is also of importance in the diagnosis of structural inheritable chromosome aberrations and consequent family investigation and genetic counseling.

Chromosome Aberrations↗
PubMed1982

Familial progressive myoclonic epilepsy. A clinical, genetical, biochemical and patho-anatomical study of a family with a 6-year follow-up.

Six siblings, including 4 cases of myoclonic epilepsy, their parents and 2 grandmothers were subjected to systematic investigation, and the patients were followed-up. The genetic studies revealed in the mother's family a patient with Lafora bodies demonstrated at autopsy. No chromosome abnormalities were found nor any linkage to the HLA system. The affected family members were characterized biochemically by an increased excretion of total glycosaminoglycans and/or an abnormal electrophoretic pattern of urinary glycosaminoglycans with an increased proportion of low-sulfated glycosaminoglycans. In the healthy family members this pattern of electrophoresis could also be demonstrated in the father and the paternal grandmother. Based on the biochemical results and the genetic studies it is suggested that the family members with progressive familial myoclonic epilepsy present a combination of at least 2 hereditary defects. The course of the disease has been relatively benign and treatment with sodium valproate, baclofen and clonazepam has shown quite satisfying results. In consequence of the biochemical findings combined treatment with A and E vitamins has been initiated.

Adolescent↗
PubMed1982

A neuropathological and neuropsychological study of Turner's syndrome.

A neuropathological study was made in 2 women with Turner's syndrome. Neuropsychological investigation in one of them correlated with what has previously been found in Turner's syndrome as well as with the localization of the most pronounced neuropathological aberration which was of atherosclerotic nature, most pronounced in the right temporo-parietal area. These findings as well as the findings of acidophile hypoplasia of the pituitary gland are discussed.

Adult↗
PubMed1982

The prevalence of chromosome abnormalities among mentally retarded persons in a geographically delimited area of Denmark.

A cytogenetic survey of an unselected group of mentally retarded persons in a geographically limited area was made in order to establish the frequency of chromosome abnormalities within this group. In the area there were 2,157 patients, both institutionalized and living at home. A chromosome analysis was performed in 1905 cases; 359 (18.8%) of these had a chromosome anomaly: 281 (14.7%) Down's syndrome, 45 (2.4%) autosomal anomaly other than Down's, and 33 (1.8%) sex chromosome anomaly. The frequency of chromosome aberrations in relation to the whole group was higher compared with similar surveys, which leads to the conclusion that the total number of mentally retarded persons living within a limited area is determined by many factors. This means that a comparison between frequencies of abnormal chromosomes in an unselected group of mentally retarded persons is only relevant when related to the whole population living in the investigation area.

Chromosome Aberrations↗
PubMed1982

Modification of the sensitivity and repair of potentially lethal damage by diethyldithiocarbamate during and following exposure of plateau-phase cultures of mammalian cells to radiation and cis-diamminedichloroplatinum(II).

Diethyldithiocarbamate (DDC), a chelating agent known to reduce levels of superoxide dismutase and glutathione peroxidase, appears to protect irradiated monolayers of mammalian cells when present for 1 hr before and during irradiation. To examine a possible cause of this modification, the repair of potentially lethal X-ray damage was examined with and without the presence of DDC in the medium overlying the cells postirradiation. Although little repair was seen in full medium alone when DDC was added to the full medium, the amount of repair was comparable to that seen under optimum repair conditions, that is, in Hanks' balanced salt solution. The t 1/2 of the repair process in Hanks' balanced salt solution or in full medium with DDC added was comparable and of the order of 1 to 1.5 hr. The cis-platinum sensitivity of the monolayers is significantly modified by the addition of DDC, and the nature of the modification is dependent upon the time at which the DDC is added to the cells following initiation of cis-platinum exposure. To investigate a possible reason for this protection by DDC, we examined the repair of potentially lethal cis-platinum damage in the cell monolayers. Minimal repair was noted in the presence of either Hanks' balanced salt solution or full medium, but when DDC was added to the full medium, the repair was tripled, and the t 1/2 of the repair process was approximately 2 hr. The ability of DDC to protect cells from exposure to both X-rays and cis-platinum, together with its augmentation of repair of potentially lethal damage following exposure to each, has broad clinical application and is being actively explored in tumor-bearing mice.

Animals↗
PubMed1982

The membrane bound ATP synthase of Escherichia coli: a review of structural and functional analyses of the atp operon.

The structure of the atp operon, which contains the genes for the eight subunits alpha, beta, gamma, delta, epsilon, a, b and c of the membrane bound ATP synthase of Escherichia coli as determined by genetic experiments and DNA sequencing, is reviewed. The localization of transcription signals, namely of one major and two minor promoters, as well as the determination of the stoichiometry of the subunits (alpha:beta:gamma:delta:epsilon:a:b:c = 3:3:1:1:1:1:2:12-15) is summarized.

ATP Synthetase Complexes↗