Biomedical subjects

M Kirchhoff

Publications and source records attributed to M Kirchhoff.

At least 37 records · Page 2Linked to original sources

PubMed1998

Detection of chromosomal gains and losses in comparative genomic hybridization analysis based on standard reference intervals.

Criteria for detection of chromosome aberrations by Comparative Genomic Hybridization (CGH) are not standardized and improvement of this part of the analysis is of paramount importance to the applicability of the technique. The aim of this work was to suggest CGH detection criteria that increase the specificity and sensitivity and at the same time include chromosome regions previously excluded from CGH analysis. We analyzed 33 hybridizations with normal DNA and modified our CGH software in order to use a selection of these normal analyses as a model for interpretation of analyses of unknown samples. This approach was successfully tested on 14 samples with known aberrations.

Chromosome Aberrations↗

PubMed1998

[The correlation between serum ferritin, alcohol consumption and social status in a population of 2235 Danes].

The objective was to examine the relationships between serum ferritin, alcohol consumption and sociodemographic factors (school education, occupational education, occupation, income, marital status, cohabituary status, housing, social class) in a survey performed in Copenhagen County during 1982-1984. The participants, selected at random, comprised 2235 Danish Caucasian individuals, all non-blood-donors (1044 men, 1191 non-pregnant women) in cohorts 30, 40, 50 and 60 years old. In all age groups, men had significantly higher serum ferritin and alcohol consumption than women. In men, there was no relationship between serum ferritin and social class. Significant relationships were observed between ferritin and occupation (unemployed and self-employed men had the highest ferritin and ferritin and income (ferritin increased with income). None of the social variables were associated with the prevalence of small or absent iron stores (serum ferritin < or = 30 micrograms/l) or abundant iron stores (serum ferritin > 300 micrograms/l). Alcohol consumption displayed relationships to occupation and become, but not to social class. In women, none of the social variables showed any relationship to ferritin levels or iron overload. The prevalence of small iron stores was lower and the make of alcohol was higher in women from high social classes. In both men and women, serum ferritin displayed significant positive correlations with alcohol consumption. Likewise, the prevalence of iron overload was closely correlated to alcohol consumption. In conclusion, sociodemographic factors per se had a minor influence on serum ferritin levels and iron status in Danes. The distinct association between alcohol consumption and serum ferritin should be considered in future epidemiological iron status surveys.

Adult↗

PubMed1997

[Prevalence of left ventricular hypertrophy in Danish patients with hypertension].

The aim of this investigation was to study the prevalence of left ventricular hypertrophy (LVH) in a hypertensive population with reference to a normotensive control group. From the general population, 3498 men and women aged 35, 45, 55 and 65 years old were invited to a health examination. Participants with blood pressure above 160 mmHg systolic and/or 95 mmHg diastolic or participants currently taking antihypertensive medication or having done so during the previous six months were asked to undergo an echocardiographic examination. Controls were randomly selected from the same population. Of 552 participants in the final study population, 194 were normotensive controls and 358 were in the hypertensive group. Echocardiographic measurements were made according to the "Penn" conventions and indexed for body surface. Cutoff values for LVH were 134 grams per m2 for males and 102 grams per m2 for women. Overall, we found that the prevalence of 1 VH was 14%/20% (men/women) in normotensives and 25%/26% in hypertensives (p < 0.01). By subdivision in age and sex groups we found that the relation between normotensives and hypertensives was significant in the age group of 65 years (p < 0.02 for males and p < 0.05 for females). The association between blood pressure and 1 VH in the general population is weak. 1 VH is only significantly more frequent among hypertensives as compared to normotensives in older people.

Aged↗

PubMed1997

Automatic correction of the interfering effect of unsuppressed interspersed repetitive sequences in comparative genomic hybridization analysis.

Comparative genomic hybridization (CGH) is a relatively new technique whose application is increasing. The method has mostly been employed for detection of chromosome aberrations in cancers, and a large amount of data in this field is accumulating. At the same time, efforts are made to improve the technique in order to increase the sensitivity and the generation of reliable results. Based on experimental data, we have developed a computer algorithm for eliminating some of the interfering effects of unsuppressed repetitive sequences in CGH analysis, and thereby improved our CGH analysis system.

Algorithms↗

PubMed1997

Fatalities from myocardial infarction in Nordic countries and Lithuania. The MONICA Investigators.

AIM: To investigate fatalities from myocardial infarction at 28 days and one-year among patients aged 35-64 years in the Nordic and Lithuanian centres participating in the World Health Organization MONICA (Monitoring of Trends and Determinants of Cardiovascular Disease) Project. METHODS AND RESULTS: Altogether 9100 myocardial infarction events registered according to the protocol of the MONICA Project were included in the study. For these events, one-year follow-up was carried out using routine mortality statistics. Fatalities were expressed as age-standardized means per year for a 3-year period from the mid-1980s. The myocardial infarction fatalities at 28 days (including out-of-hospital deaths) in the eight participating populations varied among men, between 36.5% (95% confidence interval 32.6-40.4%) in Iceland and 54.6% (51.2-57.9%) in Kaunas, Lithuania, Among women, it varied from 32.4% (26.4-38.4%) in Iceland to 57.5% (51.8-63.2%) in Glostrup, Denmark. More than half of this mortality occurred suddenly and the patient did not reach hospital alive. Fatalities for the period from day 28 to one year varied among men, from 5.3% (2.9-7.6%) in Iceland to 10.9% (8.0-13.8%) in North Karelia, Finland, and among women from 3.5% (0.4-6.5%) in Kuopio, Finland, to 13.5% (7.2-19.7%) in Glostrup, Denmark. CONCLUSIONS: Approximately half of the myocardial infarction patients died within one year after the onset of the attack and half of those who died, died out-of-hospital. While the myocardial infarction fatalities differed considerably between the participating populations, differences of this magnitude are unlikely to be totally explained by differences in the registration procedures. Further comparisons of acute coronary care and secondary prevention measures are warranted.

Adult↗

PubMed1997

Detection of chromosomal aberrations in seminomatous germ cell tumours using comparative genomic hybridization.

Comparative genomic hybridization (CGH) was used to evaluate tissue specimens from 16 seminomas in order to elucidate the pathogenesis of germ cell tumours in males. A characteristic pattern of losses and gains within the entire genomes was detected in 94% of the seminomas by comparing the ratio profiles of the tumours with a standard of cytogenetically normal genomic DNA. Losses represented 43% of the total number of alterations often affecting chromosomes and chromosome arms 4, 5, 11, 13q, and 18q. Gains amounted to 57% and were often observed on 1q, 7, 8, 12, 14q, 15q, 21q, and 22q. Aberrations of 12p and 21q appeared most consistently. Results from CGH analysis displayed no relationship to the clinical stages of the malignancy. Some rare aberrations appeared, however, only in clinical stage II and in tumours showing relapse in the contralateral testis following orchiectomy, although the alterations were not present in all of the tumours in question. Losses of 16q13-21 and gains of 9q22.1-22.2 were demonstrated in both groups, while loss of 16p12 and gains of 6p21 and 6q23.3-24 were detected in the latter group as well. In conclusion, a specific pattern of chromosomal alterations was demonstrated in the seminomas by improved detection criteria, which increased specificity and sensitivity. The rare aberrations, which appeared only in tumours in improved detection criteria, which increased specificity and sensitivity. The rare aberrations, which appeared only in tumours in clinical stage II and relapsed tumours, may be linked to tumour progression, invasiveness, and bilateral disease.

Chromosome Aberrations↗

PubMed1996

Relationship between serum ferritin, alcohol intake, and social status in 2235 Danish men and women.

The objective was to examine the relationships between serum ferritin, alcohol intake, and socioeconomic factors (school education, occupational education, occupation, income, marital status, cohabitation status, housing, social class) in a population survey performed in Copenhagen County during 1982-1984. The participants were selected at random from the census register and comprised 2235 healthy Danish individuals, non-blood donors (1044 men, 1191 women) in cohorts being 30, 40, 50, and 60 years old. The participants gave a detailed social and medical history and had a clinical examination including blood samples. In all age-groups, men had significantly higher serum ferritin and alcohol intake than women. In men, there was no relationship between serum ferritin and social class. Significant relationships were observed between ferritin and occupation (unemployed and self-employed men had higher ferritin than those with other occupations) and ferritin and income (in younger men, ferritin displayed a steady increase with income). None of the social variables were related to the prevalence of iron deficiency or iron overload. Alcohol intake was related to occupation and income, but not to social class. In women, none of the social variables showed any significant relationship to ferritin levels or iron overload. The prevalence of small iron stores (serum ferritin < or = 30 micrograms/l) was lower and the intake of alcohol was higher in women from high social classes. In both men and women, serum ferritin displayed highly significant positive correlations with alcohol intake. Likewise, the prevalence of iron overload (serum ferritin > 90th percentile) was closely correlated to alcohol intake. In conclusion, socioeconomic factors per se had a minor influence on serum ferritin levels and iron status in Danes. The distinct association between alcohol intake and serum ferritin levels should be considered in future iron status surveys.

Adult↗

PubMed1995

[Changes in smoking habits in a Danish population from 1983 to 1988].

Changes in smoking habits are described for 2,986 danes aged 30, 40, 50 and 60 examined in 1983 as part of the MONICA survey and reexamined five years later. In this period the prevalence declined by 8.1% for men and 5.9% for women. Smoking was related to social class, with an increasing proportion of smokers with decreasing social class. In 1988 the social differences had increased for females. The prevalence of cessation was 17.6% for males and 17.2% for females. The highest proportion of cessation was found among 60 year-old males. The average consumption of tobacco in the group of smokers increased over the period, the increment was higher the younger the person. The prevalence of heavy smokers (20 grams or more daily) increased especially in younger persons. The proportion of young heavy smokers was highest in the lowest social class. By logistic regression a low tobacco consumption was the most important factor associated with cessation. In addition, high social class was associated with cessation for women.

Adolescent↗

PubMed1995

Smoking behaviour in Danish adults from 1982 to 1992.

The present study describes changes during the period 1982 to 1992 in smoking prevalence, knowledge of the health consequences of smoking and analysis factors predicting quitting smoking among Danish adults. Data were collected by questionnaire in two independent cross-sectional studies in the western part of the County of Copenhagen. In 1982 the participation rate was 79% among 4807 randomly selected men and women aged 30, 40, 50 and 60 years. In 1992 it was 73% among 2226 randomly selected men and women of similar ages. Five years later 2987 of the participants from the study in 1982 were re-examined. From 1982 to 1992 the proportion of participants stating that smoking increases the risk of bronchitis, asthma, lung cancer, cancer of mouth and throat, thrombosis and hypertension increased. Knowledge was independent of smoking status. In 1982 men and women with a vocational education were more knowledgeable than those who were uneducated. This difference equalized in men during the study period. During the same period, the prevalence of smoking decreased from 62% to 52% in men and from 54% to 49% in women, but the declining prevalence was found in those with a vocational education only and an existing educational difference in smoking behaviours was enhanced. The decline in smoking in Denmark in the last decade has been associated with a narrowed gender difference and widened social difference. Knowledge of the health consequences of smoking has increased independently of these changes in smoking behaviour.

Adult↗

PubMed1995

Comparative genomic hybridization in clinical cytogenetics.

We report the results of applying comparative genomic hybridization (CGH) in a cytogenetic service laboratory for (1) determination of the origin of extra and missing chromosomal material in intricate cases of unbalanced aberrations and (2) detection of common prenatal numerical chromosome aberrations. A total of 11 fetal samples were analyzed. Seven cases of complex unbalanced aberrations that could not be identified reliably by conventional cytogenetics were successfully resolved by CGH analysis. CGH results were validated by using FISH with chromosome-specific probes. Four cases representing common prenatal numerical aberrations (trisomy 21, 18, and 13 and monosomy X) were also successfully diagnosed by CGH. We conclude that CGH is a powerful adjunct to traditional cytogenetic techniques that makes it possible to solve clinical cases of intricate unbalanced aberrations in a single hybridization. CGH may also be a useful adjunct to screen for euchromatic involvement in marker chromosomes. Further technical development may render CGH applicable for routine aberration screening.

Chromosome Aberrations↗

PubMed1994

Casual blood pressure in a general Danish population. Relation to age, sex, weight, height, diabetes, serum lipids and consumption of coffee, tobacco and alcohol.

A population survey was conducted on 3608 randomly selected Danes aged 30, 40, 50 and 60 years respectively. Of these, 3400 were not in medical treatment for arterial hypertension. The following parameters were investigated: sex, age, serum lipid levels (total cholesterol, HDL cholesterol, triglycerides), presence of diabetes mellitus, height, body mass index (BMI), and average daily consumption of coffee, tobacco and alcohol. Analysis with multiple linear regression showed that all variables with the exception of triglycerides, HDL cholesterol and height were significantly associated with systolic blood pressure. Likewise all factors except diabetes, triglycerides and height were significantly associated with diastolic blood pressure. Further analysis in which the effect of each parameter was corrected for by the effects of the remaining variables, demonstrated that apart from age and sex only BMI and high alcohol consumption were positively associated with differences in blood pressure greater than a few mmHg. However, the variation in both systolic and diastolic blood pressures was only partly accounted for by the parameters studied--in the covariates analysis R2 for systolic blood pressure was 0.28 and R2 for diastolic blood pressure was 0.30. In conclusion, this investigation demonstrated that blood pressure is relatively independent of other factors important in the development of cardiovascular disease. Of the above-mentioned factors with some influence on blood pressure only age, BMI and high alcohol consumption have potential clinical importance.

Adult↗

PubMed1993

[Iron levels in 1359 Danish women in relation to menstruation, use of oral contraceptives and parity].

Iron status was assessed by measuring serum ferritin and haemoglobin in a population survey in Copenhagen County, comprising 1359 nonpregnant women in age cohorts of 30, 40, 50, and 60 years; 809 were premenopausal and 550 postmenopausal. Premenopausal women had lower serum ferritin (median 37 micrograms/l) than postmenopausal women (median 71 micrograms/l), p < 0.0001. Of premenopausal women, 17.7% had ferritin < 15 micrograms/l (depleted iron stores), and 23.1% had ferritin levels of 15-30 micrograms/l (small iron stores). Corresponding figures in postmenopausal women were 3.3% and 10.3%. Iron deficiency anaemia (ferritin < 15 micrograms/l and haemoglobin < 121 g/l) was observed in 2.6% of pre- and 0.36% of postmenopausal women. After menstruations had ceased, there was a steep rise in ferritin levels, being most pronounced during the first 7 postmenopausal years. Pre- and postmenopausal multipara had lower ferritin than nulli- and unipara (p < 0.04), indicating that pregnancy and childbirth had a long lasting reducing influence on iron stores. The use of oral hormonal contraceptives had a marked increasing effect on iron stores, being correlated to the number of years the women had been taking the pill.

Adult↗

PubMed1993

[Smoking habits and risk of coronary heart disease, especially risk associated with low daily tobacco consumption].

The purpose of this study was to estimate the risk of acute myocardial infarction related to smoking habits, especially the risk among smokers with a daily tobacco consumption of five grams or less. The study is based on data from the 1914 population examined by the Glostrup Population Studies at the age of 50 and 60 in 1964 and 1974. Information concerning deaths and cases of hospitalisation has been obtained from national registers up to 1985. Blood pressure, lipids, body mass index and physical activity were used as confounders. It was not possible to make a definite conclusion for the group smoking five grams or less daily as a class, since both the size of the group and the number of myocardial infarctions within it were small. When tobacco consumption was used as a quantitative variable the risk of myocardial infarction was found to increase with increasing amount but the relation was found not to be non-linear. The best description of the tobacco-related risk of myocardial infarction was a logarithmically relation to daily tobacco consumption.

Denmark↗

PubMed1993

[Incidence of myocardial infarction in Denmark. Results from Dan-Monica 1982-1984].

The mortality from ischemic heart disease in Denmark has changed from a steady increase towards a decrease also in younger males during the 1980s. During this period, the Glostrup Population Studies have registered the incidence of myocardial infarction, risk factor changes and changes in medical care in Copenhagen county (320,000 inhabitants) as part of WHO MONICA, which compares 39 centres in 26 countries. The incidence of myocardial infarction during the first three years, 1982-1984, of the Heart Register, DAN-MONICA at Glostrup Hospital, is reported. The register is complete and valid. If the age specific incidence of myocardial infarction in Denmark was as in this survey, the results indicate an age standardized incidence for the Danish population including all age groups over the age of 25 of 5.58 per 1000 per year (7.48 per 1000 adult males and 3.99 per 1000 adult females).

Adult↗

PubMed1992

Iron status markers, serum ferritin and hemoglobin in 1359 Danish women in relation to menstruation, hormonal contraception, parity, and postmenopausal hormone treatment.

Iron status was assessed by measuring serum (S-) ferritin and hemoglobin (Hb) in a population survey comprising 1359 nonpregnant Danish women, in age cohorts of 30, 40, 50, and 60 years; 809 were premenopausal and 550 postmenopausal. Median age for menarche was 14 years, for menopause (artificial and natural) 48 years. Premenopausal women had lower S-ferritin (median 37 micrograms/l) than postmenopausal women (median 71 micrograms/l; p less than 0.0001). Of the premenopausal women, 17.7% had S-ferritin less than 15 micrograms/l (i.e., depleted iron stores), and 23.1% S-ferritin of 15-30 micrograms/l (i.e., small iron stores). Corresponding figures in postmenopausal women were 3.3% and 10.3%. Hb values in premenopausal women were mean 137 +/- 10 (SD) g/l (8.5 +/- 0.6 mmol/l) vs. 140 +/- 10 g/l (8.7 +/- 0.6 mmol/l) in postmenopausal women (p less than 0.0001); 4.1% of pre- and 3.3% of postmenopausal women had values less than 121 g/l (7.5 mmol/l). Iron deficiency anemia (i.e., S-ferritin less than 15 micrograms/l and Hb less than 121 g/l) was found in 2.6% of pre- and 0.36% of postmenopausal women. Premenopausal multipara had lower S-ferritin than nulli- and unipara (p less than 0.04). The use of oral contraceptives had a marked influence on iron stores; premenopausal women taking the pill had higher S-ferritin and a lower frequency of depleted iron reserves than nonusers (p less than 0.01). Postmenopausal estrogen treatment had no influence on S-ferritin or Hb.

Adolescent↗

PubMed1992

Iron stores in 1359, 30- to 60-year-old Danish women: evaluation by serum ferritin and hemoglobin.

Iron status, including serum (S-)ferritin and hemoglobin (Hb), was assessed in a population survey comprising 1359 nonpregnant Danish women in age cohorts of 30, 40, 50, and 60 years. S-ferritin levels were similar in 30- and 40-year-old women; they displayed a significant increase in 50-year-old women and a further significant increase in 60-year-old women. In the 30- and 40-year-old women, median S-ferritin was 38 micrograms/l, 5-95 percentile 6-135 micrograms/l; 17.2% had values less than 15 micrograms/l (i.e., depleted iron stores), 22.7% values from 15 to 30 micrograms/l (i.e., small iron stores), and 60.1% values greater than 30 micrograms/l (i.e., replete iron stores). In the 50-year-old women, median S-ferritin was 54 micrograms/l, 5-95 percentile 10-164 micrograms/l; 10.3% had values less than 15 micrograms/l, 16.5% values from 15 to 30 micrograms/l, and 73.2% values greater than 30 micrograms/l. For the 60-year-old women, median S-ferritin was 84 micrograms/l, 5-95 percentile 25-249 micrograms/l; 1.6% had values less than 15 micrograms/l, 8.6% values from 15 to 30 micrograms/l, and 89.8% values greater than 30 micrograms/l. Blood donors (n = 180) had lower S-ferritin than nondonors in all age-groups (p less than 0.001). In the entire series, Hb levels were similar in 30- and 40-year-old women, median 137 milligrams (8.5 mmol/l), 5-95 percentile 121-152 milligrams (7.5-9.4 mmol/l), and higher in 50- and 60-year-old women, median 140 milligrams (8.7 mmol/l), 5-95 percentile 123-158 milligrams (7.6-9.8 mmol/l) (p less than 0.0001). Hb values less than 121 milligrams (7.5 mmol/l) were observed in 3.8% of the women. Women with S-ferritin less than 15 micrograms/l (n = 161) had lower Hb, median 134 milligrams (8.3 mmol/l), than those with S-ferritin greater than or equal to 15 micrograms/l, median 139 milligrams (8.6 mmol/l) (p less than 0.001). Iron deficiency anemia (S-ferritin less than 15 micrograms/l and Hb less than 121 milligrams) was seen in 2.3% of 30- and 40-year-old women, and in 1.1% of 50- and 60-year-old women.

Adult↗

PubMed1991

The influence of blood donation on iron stores assessed by serum ferritin and hemoglobin in a population survey of 1359 Danish women.

The general impact of blood donation on iron status was studied in a population survey comprising 1359 nonpregnant Danish women in age cohorts of 30, 40, 50, and 60 years; 809 were premenopausal and 550 postmenopausal; 180 (13%) were blood donors. Iron stores were assessed by serum (S)-ferritin and hemoglobin (Hb). Hb levels were not significantly different in donors: mean 137 +/- 10 (SD) g/l (8.5 +/- 0.6 mmol/l) compared with nondonors, 139 +/- 11 g/l (8.6 +/- 0.7 mmol/l). Values less than 121 g/l (7.5 mmol/l) were observed in 3.3% of donors vs 3.8% of nondonors. Correlations between S-ferritin and Hb were without practical relevance: rs = 0.29, p less than 0.0001 in donors vs rs = 0.22, p less than 0.0001 in nondonors. Blood donation had a profound influence on iron status, especially in the premenopausal women population. Donors had lower S-ferritin than nondonors in all age-groups and in pre- and postmenopausal groups (p less than 0.001 in all groups). Premenopausal donors had a median S-ferritin of 31 micrograms/l vs 39 micrograms/l in nondonors, postmenopausal donors of 47 micrograms/l vs 72 micrograms/l in nondonors. S-ferritin values less than 15 micrograms/l (i.e., depleted iron stores) were observed in 31.7% of premenopausal donors vs 15.2% of nondonors, and in 7.0% of postmenopausal donors vs 2.9% of nondonors. Iron deficiency anemia (i.e., S-ferritin less than 15 micrograms/l and Hb less than 121 g/l) was seen in 2.8% of donors vs 1.5% of nondonors. Donors using oral contraceptives had higher S-ferritin, median 33 micrograms/l compared with nonusers, 22 micrograms/l, and a lower frequency of depleted iron stores, 29% vs 39%. Ideally, the frequency of phlebotomy should be adjusted according to S-ferritin as well as Hb levels. If Hb is used as single criterion for donation, only donors with predonation values greater than or equal to 124-125 g/l should be allowed to undergo phlebotomy.

Adult↗

PubMed1991

Influence of blood donation on iron stores assessed by serum ferritin and haemoglobin in a population survey of 1433 Danish males.

The general impact of blood donation on iron status has been studied in Danish males. Iron stores were assessed by serum (S-) ferritin and haemoglobin (Hb) in a population survey comprising 1433 males in age cohorts of 30, 40, 50, and 60 years; 389 (27%) were blood donors and 1044 (73%) non-donors. Hb levels were identical in donors and non-donors, mean 155 +/- 11 (SD) g/l (9.6 +/- 0.7 mmol/l); values less than 129 g/l (8.0 mmol/l) were observed in 1.3% of donors vs 1.9% of non-donors. Correlations between S-Ferritin and Hb were slight and without practical clinical relevance: rS = 0.13, p less than 0.01 in donors vs rS = 0.16, p less than 0.0001 in non-donors. Donors had lower S-Ferritin, median 95 micrograms/l, than non-donors, median 136 micrograms/l (p less than 0.0001). S-Ferritin values less than 15 micrograms/l (i.e. depleted iron stores) were seen in 3.3% of donors vs 0.4% of non-donors, and S-Ferritin values of 15-30 micrograms/l (i.e. small iron stores) in 9.8% of donors vs 1.4% of non-donors. Iron-deficiency anaemia (i.e. S-Ferritin less than 15 micrograms/l and Hb less than 129 g/l) was seen in 0.26% of donors vs 0.10% of non-donors; employing the 5th percentile for Hb (137 g/l (8.5 mmol/l] as discriminatory value increased the percentage of iron-deficiency anaemia to 0.51% in donors vs 0.10% in non-donors. Blood donation had a marked influence on iron status in the adult male population. The frequency of phlebotomy should be adjusted according to S-Ferritin as well as Hb levels. If Hb is used as single criterion for donation, only donors with pre-donation values greater than or equal to 135-137 g/l should be allowed phlebotomy. Optimal donation standards should include monitoring of iron status through measurement of S-Ferritin and Hb, combined with individualised postdonation iron supplementation.

Adult↗