Biomedical subjects
J Nielsen
Publications and source records attributed to J Nielsen.
The genes for the eight subunits of the membrane bound ATP synthase of Escherichia coli.
The genes for the eight subunits of the membrane bound ATP synthase of Escherichia coli (Ca++, Mg++ dependent ATPase, EC 3.6.1.3) were mapped through genetic, physical and functional analysis of specialized transducing phages lambda asn (von Meyenburg et al. 1978). The ATP synthase genes, designated atp1, are located at 83.2 min in a segment of the chromosome between 3.5 and 11.3 kb left (counterclockwise) of the origin of replication oriC. The counterclockwise order of the genes for the eight subunits, the expression of which starts from a control region at 3.5 kb-L, was found to be: a, (c, b, delta), alpha, gamma, (epsilon, beta) which in the notation of Downie el al. (1981) reads atp B (EFH) A G (C D). The analysis was in part based on the isolation of new types of atp (unc, Suc-) mutations. We made use of the fact that specialized transducing phages lambda asn carrying oriC can establish themselves as minichromosomes rendering asnA cells Asn+, and that the resulting Asn+ cells grow slowly if the lambda asn carries part or all of the atp operon. Selecting for fast growing strains mutations were isolated on the lambda asn which either eliminated atp genes or affected their expression ("promoter" mutations). The relationship between these atp mutations and the cop mutations of Ogura et al. (1980), which also appear to map in front of or within the atp genes, is discussed.
The nucleotide sequence of the atp genes coding for the F0 subunits a, b, c and the F1 subunit delta of the membrane bound ATP synthase of Escherichia coli.
The nucleotide sequence has been determined of a 2,500 base pair segment of the E. coli chromosome located between 3.75 and 6.25 kb counterclockwise of the origin of replication at 83.5 min. The sequence contains the atp genes coding for subunits a-, b-, c-, delta- and part of the alpha-subunit of the membrane bound ATP synthase. The precise start positions of the atpE (c), atpF (b), atpH (delta) and atpA (alpha) genes have been defined by comparison of the potential coding sequences with the known amino acid sequence of the c-subunit and the determined N-terminal amino acid sequences of the respective subunits. The genes are expressed in the counterclockwise direction. Their order (counterclockwise) is: atpB (a), atpE (c), atpF (b), atpH (delta) and atpA(alpha). The coding sequences for subunits b and delta yield polypeptides of 156 and 177 amino acids, respectively, in accordance with the established sizes of these subunits; the one for the c-subunit, the DCCD binding protein, fits perfectly with its known sequence of 79 amino acids. The a-subunit is comprised within a coding sequence yielding a polypeptide of 271 amino acids. It is suggested, however, that the a-subunit (atpB) contains only 201 amino acids, in accordance with its known size, starting from a translation initiation site within the larger coding sequence. The stoichiometry of the F0 sector subunits is discussed and a model is proposed for the functioning of the highly charged b-subunit of the F0 sector as the actual proton conductor.
Chromosome abnormalities in newborn children. Physical aspects.
A chromosome examination was made on 11,148 consecutively live-born children: 93 had a chromosome abnormality and 192 a chromosome variant. The physical aspects of the children with chromosome abnormalities and variants were compared with those of the children with normal karyotypes. Children with aneuploid or unbalanced chromosome abnormalities were more immature or not fully developed at birth than those with normal karyotypes. Birth weight was lower in children with all types of chromosome abnormalities, including reciprocal translocations and chromosome variants. The low birth weight in children with chromosome variants was mainly due to the low birth weight of children with G variants. These children were also subject to a higher frequency of special delivery treatment. Heart disorders were increased in children with aneuploid or unbalanced chromosome abnormalities. The frequency of foetal erythroblastosis was increased in children with short Y as well as in children with acentric fragments. Neonatal mortality was higher in children with aneuploid or unbalanced chromosome abnormalities than in children with normal karyotypes.
Mental development of unselected children with sex chromosome abnormalities.
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Follow-up of 32 children with autosomal translocations found among 11,148 consecutively newborn children from 1969 to 1974.
A follow-up study of 32 unselected children with translocations has been made from 6 to 11 years after the chromosome examination of these children at birth. The physical and mental development of the five children with de novo translocations was very similar to that of the children with inherited translocations, and we found no indication of any association between the autosomal reciprocal translocations for the Robertsonian translocations and physical and mental development. There was an increased risk for offspring with unbalanced or aneuploid chromosome abnormalities in 2 of the 30 families, and prenatal examination is most probably indicated in carriers of any type of translocation. Further studies of large groups of unselected persons with translocations are, however, needed before any definite risk figures can be calculated for the different translocations.
Chromosome examination of children, in two Danish counties, born during the period 1967-1978. Epidemiological data.
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Isolation of Mallory bodies and an attempt to demonstrate cell mediated immunity to Mallory body isolate in patients with alcoholic liver disease.
Mallory bodies were isolated from necropsy livers from patients with alcoholic hepatitis with and without cirrhosis with a Ficoll viscosity barrier. The purity of Mallory bodies in the isolate varied between 70 and 90%, estimated by counting Mallory bodies and non-Mallory body structures in haematoxylin-eosin stained smears. Electron microscopy confirmed the presence of Mallory bodies in the isolates. The Mallory body isolate was used as antigen in the agarose leucocyte migration inhibition test in order to test the cell-mediated immunity. No significant difference in leucocyte migration was found between controls and patients with alcoholic hepatitis, alcoholic steatosis, alcoholic cirrhosis and miscellaneous liver diseases.
Meal-stimulated secretin release in man: effect of acid and bile.
Nine normal subjects were studied before and after intragastric instillation of a liquid meal. Gastric emptying rates of acid and pancreaticobiliary secretions were quantitated by means of a dilution indicator technique. A significant, positive correlation was found between load of acid to the duodenum and the concentration of secretin in plasma. No correlation was found between load of the bile acids and plasma secretin. The buffering capacity of gastric contents should be taken into account when fasting and postprandial periods are compared. Plasma secretin concentration remained low during the first postprandial hour. Maximum secretin concentrations and duodenal disappearance rate of acid was observed 1 1/2-2 h after instillation of the meal. In contrast, trypsin output was maximum within 10 min. The data support the concept that in man release of secretin is governed principally by the amount of hydrogen ions emptied into duodenum and indicate the importance of secretin in the late postprandial period, when the acidity of the gastric contents is high.
Sex ratio in Down syndrome.
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Invasive cancer following outpatient evaluation and therapy for cervical disease.
Factors relating to the inappropriate therapy of 66 cases of cervical cancer are reviewed. The patients are divided into 2 major categories: 1) 33 who underwent cryosurgery or hot cautery without colposcopy; 2) 9 who underwent colposcopy without outpatient therapy; and 3) 24 who underwent colposcopy followed by outpatient therapy. Of the patients who had outpatient therapy without colposcopy, the major indication for treatment was "cervicitis," and all had a normal Papanicolaou smear. Of the 33 patients who underwent colposcopy because of an abnormal Papanicolaou smear, the proper treatment evaluation was carried out in only 5. The endocervical curettage (ECC) was omitted in 17 patients; no biopsies were taken in 8 patients; and conization of the cervix was omitted in 3 patients who had a positive ECC. Recommendations are made to minimize the inappropriate use of the outpatient approach in patients with cervical disease.
[Pertrochanteric fracture of the femur. Early weight-bearing after osteosynthesis by McLaughlin's method].
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[Team work between the community health nurse and the general practitioner: support each other in catching children's smallest signals].
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[Impressions from a study tour of China].
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Chromosome variants in children referred for cytogenetic examination from two paediatric departments during a 12-year-period.
The present study deals with frequency and clinical signs of children with chromosome variants. Previous studies of the possible effect of different chromosome variants on phenotype and risk of congenital abnormalities are controversial.
Cell selection in vivo. Follow-up of nine unselected mixoploid children.
A cytogenetic follow-up has been made of nine mixoploid children found among 11 148 consecutive newborn children. The frequency of the cell line with normal chromosomes increased in all but two, and the increase was statistically significant, being from 20% to 39% in four cases, and from 1% to 17% in three, while in one case there was no difference from the first to the last examination. The possibility that children with mixoploid chromosome abnormalities at birth will reveal no cell line with a chromosome abnormality in lymphocyte cultures as adults, despite having clinical signs of the chromosome aberration found in one cell line at birth is discussed, as is the question of cell selection in vivo. The mixoploid children had fewer clinical symptoms and fewer signs of the chromosome abnormalities found in some of their cells than children with the same chromosome abnormalities in all cells.
Follow-up 10 years later of 34 Klinefelter males with karyotype 47,XXY and 16 hypogonadal males with karyotype 46,XY.
A 10-year follow-up study is reported of 50 hypogonadal males, 34 of whom had the karyotype 47,XXY and 16 karyotype 46,XY. The social class of the former group was significantly lower and the frequency of criminal behaviour higher when compared with the latter group and the Danish male population. The frequency of mental illness was higher in the Klinefelter males with karyotype 47,XXY than in the remainder. The aetiology and pathogenesis of deviant mental development in the patient population and various aspects of their treatment are discussed.