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Biomedical subjects

J Lindsten

Publications and source records attributed to J Lindsten.

At least 37 records · Page 2Linked to original sources
PubMed1984

European collaborative study on prenatal diagnosis: mosaicism, pseudomosaicism and single abnormal cells in amniotic fluid cell cultures.

A report is given of the results of a European collaborative study on mosaicism, pseudomosaicism and single abnormal cells in amniotic fluid cell cultures. The mean frequency of cases with mosaicism was 0.10 per cent, with pseudomosaicism 0.64 per cent and with single abnormal cells 2.83 per cent in a series of 44 170 amniotic fluid samples. There was no significant difference between the colony (in situ) and the flask method with regard to the frequency of mosaicism. Pseudomosaicism and single abnormal cells were more frequent in cases studied with the flask method probably due to other factors than the method of cultivation of the cells. The frequency of maternal cell contamination was 0.17 per cent and the frequency of wrong sex assignment was 0.11 per cent. A more correct estimation is obtained if these frequencies are doubled. There was a considerable variation between laboratories with regard to the frequencies given above. One reason for this variation is that there are no sharp limits between mosaicism, pseudomosaicism and single abnormal cells. Thus the material contained cases diagnosed as having pseudomosaicism which turned out to be mosaics at birth and to have an abnormal phenotype. These cases were very rare but pose a definite problem in prenatal cytogenetic diagnosis.

Amniotic Fluid↗
PubMed1983

Flow karyotype analysis and fluorescence-activated sorting of Burkitt-lymphoma-associated translocation chromosomes.

Flow karyotype analysis was performed to assess the feasibility of fluorescence-activated sorting of Burkitt lymphoma (BL)-associated translocation chromosomes. The typical 14q+ chromosome in the t(8;14) and the two "variant translocations", the 2q+ in the t(2;8) and the small 22q- in the t(8;22), could be identified as single peaks within the flow karyotypes of metaphase chromosomes isolated from several different BL-lines for each translocation. The translocation chromosomes could be separated with a high degree of purity and in quantities suitable for biochemical analysis. The same analytical and preparative technique was also successfully applied to the identification and sorting of the Philadelphia (Ph1) chromosome in a 9;22 translocation-carrying CML-derived line and a familial (11;22) translocation.

Burkitt Lymphoma↗
PubMed1983

The 11q;22q translocation: a collaborative study of 20 new cases and analysis of 110 families.

Following a previous collaborative study (Fraccaro et al. 1980), 20 new cases of 11q;22q translocation are described. Twelve families were ascertained through an unbalanced carrier of the translocation and eight cases were ascertained as balanced carriers. A segregation analysis was performed on the 110 families so far published. It was concluded that the 11q;22q translocation is a relatively frequent event, and that all the cases thus far reported might have the same breakpoints at 11q23.3 and 22q11.2. The translocation seems to be independent of environmental factors and it seems to have a low rate of mutation as indicated by the scarcity of de novo cases. The new data confirmed that only one type of unbalanced karyotype (47,XX or XY+der(22)t(11;22)(q23.3;q11.2)) is found among the offspring of the translocation carriers. The minimal overall recurrence risk for an unbalanced translocation was estimated to 2%. There was no difference between the recurrence risks for male and female balanced carriers, while the trend was confirmed of an excess of female balanced carriers among the phenotypically normal offspring of the t(11;22) female carriers.

Abnormalities, Multiple↗
PubMed1983

Genetic regulation of the red cell uroporphyrinogen-I-synthetase level in families with acute intermittent porphyria.

The uroporphyrinogen-I-synthetase (UIS) activity in red blood cells was determined in 206 individuals from 48 nuclear families ascertained through a proband with acute intermittent porphyria (AIP) as well as in 230 members belonging to 53 nuclear families with no signs of AIP. Complex segregation analysis showed that the UIS activity is regulated by a major locus (a dominant or additive gene) together with a considerable multifactorial component.

Ammonia-Lyases↗
PubMed1983

Lack of correlation between contraceptive pills and Down's syndrome.

A case-control study has been made on the use of oral contraceptives before pregnancy and the birth of an infant with Down's syndrome. Controls were matched for age and parity and selected from the Medical Birth Register. Information on Pill usage was obtained from the Swedish standardized maternity health record which contains dates for when the women stopped using the Pill and for last menstrual period. There was no indication of any relation between the use of oral contraceptives and Down's syndrome.

Adolescent↗
PubMed1982

Late side effects of chemotherapy in ovarian carcinoma: a cytogenetic, hematologic, and statistical study.

Late side effects of chemotherapy were studied in 51 women who had received at least 300 mg of melphalan for ovarian cancer and had survived for at least three years. Hematologic, statistical, and cytogenetic methods were employed. Six cases of iatrogenic leukemia were found. They appeared to represent a hematologic entity that is fairly difficult to recognize. The risk of iatrogenic leukemia in women who survived for three years or more after melphalan treatment was calculated to be 950 times greater than the leukemia risk in the total female population. The cytogenetic changes were studied with three methods focused on sister chromatid exchange, chromosome aberrations, and DNA damage. The sister chromatid exchange frequency showed a marked increase, but it was corrected within a few months. Chromosome aberrations expressed by chromosome rearrangements were increased in the peripheral lymphocytes and may persist for several years. The frequency of DNA stand breaks was decreased indicating the presence of DNA cross-links. Any of these types of genetic alteration could be the initiating event in carcinogenesis.

Acute Disease↗
PubMed1982

Correlation between the number of sex chromosomes and the H-Y antigen titer.

H-Y antigen was studied serologically on blood cells and cultured fibroblasts of patients with numerical aberrations of the sex chromosomes. As compared with normal males, patients with the karyotypes 48,XXXY and 49,XXXXY have reduced H-Y antigen titers; a tendency toward reduced titers can also be detected in the 47,XXY Klinefelter syndrome. The existence of an intermediary titer was further substantiated by a quantitative absorption test applied to cells with the 49,XXXXY karyotype. It appears that in the presence of one Y chromosome, the H-Y antigen titer decreases with an increasing number of X chromosomes. In contrast, the H-Y antigen titer is increased if, at a given number of X chromosomes, the number of Y chromosomes is increased, as in the 47,XYY male. Consequently, patients with 48,XXYY chromosomes are in the male control range. The findings are interpreted under the hypothesis of a controlling or modifying influence of the sex chromosomes on the titer of H-Y antigen.

Adolescent↗
PubMed1982

Evidence for an autosomal recessive gene regulating the persistence of the insulin response to glucose in man.

The significance of genetic factors for insulin release after glucose infusion was studied in 155 nuclear families of which 59 were control families and 96 had been ascertained through a parent with onset of diabetes after 30 years of age. Fasting insulin and glucose as well as three principal components of the insulin and glucose curves were submitted to path analysis and complex segregation analysis. The three principal components were considered to reflect the magnitude, the degree of response and the persistence of the curves. The genetic heritability of the insulin variables varied between 0.47-0.93 and that of the glucose variables between 0.20-0.54. There were considerable intergenerational differences in the genetic heritability for the persistence of the glucose curve and for the degree of response and persistence of the insulin curve. The cultural heritability was found to be of minor importance, while the non-transmitted sibling environment was large. There was significant evidence for a major locus for the persistence of the insulin curve. The best fit was for a completely recessive autosomal gene with the gene frequency 0.21. The phenotype distribution of this variable showed significant kurtosis which could simulate a major locus. However, the significant evidence for such a locus remained after an analysis using partial quantitation. The diabetics were significantly different from the non-diabetics for all the variables studied, but a complete discrimination between the diabetics and non-diabetics could not be obtained. There was no significant difference between the children of the diabetics and non-diabetics for any of the variables studied.

Adult↗
PubMed1982

DNA and chromosome alterations in lymphocytes of operating room personnel and in patients before and after inhalation anaesthesia.

In order to evaluate the possible genotoxic effects of inhalation anaesthetics, the frequency of sister chromatid exchanges and chromosome aberrations was studied in peripheral lymphocytes of control subjects, operating room personnel and patients before and after inhalation anaesthesia during orthopaedic operations. In the patients, the frequency of DNA breaks was studied as well. None of the genotoxic parameters showed an increase which could be related to anaesthetic exposure. The frequency of sister chromatid exchange was very similar in the control and personnel groups, as well as in patients before and after operation. The frequency of chromosome aberrations was unusually low in the control group, whereas the personnel and patient groups showed normal levels of chromosome aberrations which did not differ from previously studied control groups. There was no statistical difference in the frequency of chromosome aberrations or DNA breaks in the patient group after, as compared to before, operation. Smokers were found to have a significantly increased frequency of chromosome gaps compared to nonsmokers, but there was no indication that this difference was related to anaesthetic exposure. The data presented give no indications of genotoxic effects in vivo of inhalation anaesthetics by either occupational exposure to waste anaesthetic gases, or anaesthesia during operation. On the other hand, our present data do not contradict previous data indicating that hospital personnel, irrespective of exposure to inhalation anaesthetics, may have a small average increase of chromosome abnormalities.

Adult↗
PubMed1982

Smoking and sister chromatid exchange.

Smokers were shown to have significantly higher SCE levels in peripheral lymphocytes than non-smokers. The increase of SCE was found to depend on the cigarette consumption, and to be significantly higher in subjects with a long than with a short history of smoking. Analysis of the frequency distribution of individual SCE levels and of SCE numbers in single cells gave no indication of subgroups of individuals of subpopulations of lymphocytes with an increased SCE response to smoking. Cells from smokers cultivated in plasma from non-smokers retained a high SCE level, and cells from non-smokers cultivated in plasma from smokers no increase of SCE, indicating that the increase of SCE caused by smoking is due to some type of (long-lived) cellular damage rather than to serum factors. The plasma levels of the primary nicotine metabolite cotinine were found to be increased in heavy smokers as compared to light smokers, and showed an excellent correlation with the cotinine levels in the amniotic fluid in pregnant female smokers. No correlation was found between the individual SCE and cotinine levels in smokers, which indicates that the degree of exposure to SCE-inducing genotoxic agents in the cigarette smoke is not related to plasma cotinine levels in any simple way. The induction of DNA strand breaks and SCE by two intermediary benzo(a)pyrene (BP) metabolites was studied in human lymphocytes in vitro. Both 9-OH-BP and BP-7,8-dihydrodiol were found to induce DNA breaks, but only the latter compound induced SCE. The SCE-inducing effect of BP-7,8-dihydrodiol was observed at a very low concentration (0.01 microM), which indicates a possible role for this BP derivative in the smoking-induced increase of SCE in vivo.

Benzopyrenes↗
PubMed1981

Sex-reversed XY females with campomelic dysplasia are H-Y negative.

Three families with infants affected with campomelic dysplasia, a genetically determined mesenchymal disease frequently associated with sex reversal were studied. Two XY females with ovarian gonadal differentiation and typical clinical features of campomelic dysplasia could be tested for H-Y antigen and were found to be H-Y negative.

Bone and Bones↗