Biomedical subjects

C Johansen

Publications and source records attributed to C Johansen.

At least 37 records · Page 2Linked to original sources

PubMed2002

Mobile phones and malignant melanoma of the eye.

Recently a four-fold increase in the risk of malignant melanoma of the eye was associated with the use of radiofrequency transmitting devices, including mobile phones in Germany. We contrasted the incidence rates of this rare cancer with the number of mobile phone subscribers in Denmark. We observed no increasing trend in the incidence rate of melanoma, which was in sharp contrast to the exponentially increasing number of mobile phone subscribers starting in the early 1980s. Our study provides no support for an association between mobile phones and ocular melanoma.

Cohort Studies↗

PubMed2002

Mind and cancer. do psychological factors cause cancer?

We have reviewed the evidence for an association between major life events, depression and personality factors and the risk for cancer. We identified and included only those prospective or retrospective studies in which the psychological variable was collected independently of the outcome. The evidence failed to support the hypothesis that major life events are a risk factor for cancer. The evidence was inconsistent for both depression and personality factors. Chance, bias or confounding may explain this result, as many of the studies had methodological weaknesses. The generally weak associations found, the inconsistency of the results, the unresolved underlying biological mechanism and equivocal findings of dose-response relationships prevent a conclusion that psychological factors are established risk factors. However, certain intriguing findings warrant further studies, which must, however, be well conducted and large and include detailed information on confounders.

Bereavement↗

PubMed2002

Mind and cancer: does psychosocial intervention improve survival and psychological well-being?

The aim of this review was to evaluate the scientific evidence for an effect of psychosocial intervention on survival from cancer and well-being and in particular on anxiety and depression. A literature search yielded 43 randomised studies of psychosocial intervention. Four of the eight studies in which survival was assessed showed a significant effect, and the effect on anxiety and depression was also inconsistent, indicating three possible explanations: (i) only some of the intervention strategies affect prognosis and/or well-being and in only certain patient groups; (ii) the effect was weak, so that inconsistent results were found in the generally small study populations; or (iii) the effect was diluted by the inclusion of unselected patient groups rather than being restricted to patients in need of psychosocial support. Thus, large-scale studies with sound methods are needed in which eligible patients are screened for distress. Meanwhile, the question of whether psychosocial intervention among cancer patients has a beneficial effect remains unresolved.

Anxiety↗

PubMed2002

Cancer incidence and magnetic field exposure in industries using resistance welding in Sweden.

AIMS: To investigate cancer incidence in workers exposed to high levels of extremely low frequency magnetic fields (ELF-MF). METHODS: A cohort based on the engineering industry was established. Industries assumed to use resistance welding in production were chosen in order to increase the prevalence of high exposed subjects and to reduce the influence of confounding factors. All men and women employed in these branches during 1985-94 were selected, 537 692 men and 180 529 women. Occupation, based on census information from 1980, 1985, and 1990, was linked to a job exposure matrix on ELF-MF. Four exposure groups were used by stratifying on mean workday ELF-MF exposure, using the lowest exposure group as reference. Cancer incidence was obtained by linkage to the Swedish Cancer Registry. RESULTS: Men in the very high exposure group showed an increased incidence of tumours of the kidney, pituitary gland, and biliary passages and liver; for these cancer sites an exposure-response relation was indicated. Women in the very high exposure group showed an increased incidence of astrocytoma I-IV, with a clear exposure-response pattern. An association was suggested in the high exposure group only, for cancer of the corpus uteri and multiple myeloma. Decreased risks in the very high exposure group among men were found for cancer of the colon and connective tissue/muscle. CONCLUSIONS: The results on cancer of the liver, kidney, and pituitary gland among men are in accordance with previous observations. Regarding brain tumours and leukaemia, the outcome for women provided further support of an association. The hypothesis of a biological mechanism involving the endocrine system was partly supported.

Cohort Studies↗

PubMed2001

[Exposure to electromagnetic fields and risk of central nervous system diseases among employees at Danish electric companies].

INTRODUCTION: Occupational exposure to electromagnetic fields has been associated with neurological diseases, such as amyotrophic lateral sclerosis, senile dementia, Parkinson's disease and Alzheimer's disease. MATERIAL AND METHOD: I studied the incidence of disease in the central nervous system in 30,631 persons employed at Danish electric companies between 1900 and 1993. I linked the cohort to the nationwide, population-based Danish National Register of Patients and compared the number of cases of these diseases found between 1978 and 1993 with the corresponding rates in the general population. In addition, I fit the data on utility workers to a multiplicative Poisson regression model in relation to estimated levels of exposure to 50 Hz electromagnetic fields. RESULTS: Overall, there was an increase in the risk of senile dementia and motor neuron diseases combined. The incidences of Parkinson's disease, Alzheimer's disease and other diseases of the central nervous system were essentially unrelated to exposure to electromagnetic fields. A decreased risk of epilepsy compared with the general population probably reflects a healthy worker effect; I observed an increased risk of epilepsy based on internal comparisons. DISCUSSION: The increased risk of senile dementia and motor neuron diseases may be associated with above average levels of exposure to electromagnetic fields.

Alzheimer Disease↗

PubMed2001

Extroversion and neuroticism and the associated risk of cancer: A Danish cohort study.

The authors have investigated the effect of personality, as measured with the Eysenck Personality Inventory, on the incidence of cancer among 1,031 persons participating in a Danish health survey in 1976-1977 and followed up for 20 years. They thereby accrued a total of 19,993 person-years. The expected number of cancer cases was estimated on the basis of age-, sex-, and site-specific incidence rates in Copenhagen County, DENMARK: Overall, 113 malignancies were observed among the cohort members between the date of interview and December 31, 1996. Since 114.3 were expected from county incidence rates, the standardized incidence ratio was 0.99 (95% confidence interval: 0.81, 1.19). No statistically significant deviation of the relative risk from unity was seen for any measure of personality, and no excess risk was seen for any particular type of cancer. A regression model, in which adjustment was made for age, sex, calendar period, alcohol consumption, tobacco smoking, psychiatric illness as rated by the interviewing doctor, marital status, and social class, showed no excess risk of cancer among persons considered to be in medium- or high-risk groups according to the Eysenck Personality INVENTORY: The authors' data provide no support for the hypothesis of an association between personality and the risk of cancer.

Aged↗

PubMed2001

Cellular telephones and cancer--a nationwide cohort study in Denmark.

BACKGROUND: Use of cellular telephones is increasing exponentially and has become part of everyday life. Concerns about possible carcinogenic effects of radiofrequency signals have been raised, although they are based on limited scientific evidence. METHODS: A retrospective cohort study of cancer incidence was conducted in Denmark of all users of cellular telephones during the period from 1982 through 1995. Subscriber lists from the two Danish operating companies identified 420 095 cellular telephone users. Cancer incidence was determined by linkage with the Danish Cancer Registry. All statistical tests are two-sided. RESULTS: Overall, 3391 cancers were observed with 3825 expected, yielding a significantly decreased standardized incidence ratio (SIR) of 0.89 (95% confidence interval [CI] = 0.86 to 0.92). A substantial proportion of this decreased risk was attributed to deficits of lung cancer and other smoking-related cancers. No excesses were observed for cancers of the brain or nervous system (SIR = 0.95; 95% CI = 0.81 to 1.12) or of the salivary gland (SIR = 0.72; 95% CI = 0.29 to 1.49) or for leukemia (SIR = 0.97; 95% CI = 0.78-1.21), cancers of a priori interest. Risk for these cancers also did not vary by duration of cellular telephone use, time since first subscription, age at first subscription, or type of cellular telephone (analogue or digital). Analysis of brain and nervous system tumors showed no statistically significant SIRs for any subtype or anatomic location. CONCLUSIONS: The results of this investigation, the first nationwide cancer incidence study of cellular phone users, do not support the hypothesis of an association between use of these telephones and tumors of the brain or salivary gland, leukemia, or other cancers.

Adult↗

PubMed2001

Anorexia nervosa and cancer risk.

OBJECTIVE: Energy restriction reduces the incidence of malignant tumors in experimental animals, but evidence for a similar effect in humans is lacking. To test the hypothesis in humans, we investigated cancer incidence among patients with anorexia nervosa, who have had an extremely low intake of calories for prolonged periods of their lives. METHODS: Patients with anorexia nervosa (2151 women and 186 men) during 1970-1993 were identified in the population-based Danish Psychiatric Case Register and the National Registry of Patients. The cohort was linked to the Danish Cancer Registry, and cancer incidence among cohort members was compared with that of the general population. RESULTS: The overall cancer incidence among women with anorexia nervosa was reduced by a factor of 0.80 (95% confidence interval 0.52-1.18) below that of the general population on the basis of 25 observed and 31.4 expected cases. Among men, two cases of cancer were observed, both confined to the brain, whereas 0.2 cases were expected. CONCLUSIONS: The finding of a slight reduction in cancer risk among women with anorexia nervosa may support the theory that a low-energy diet may decrease tumor development in humans. However, longer follow-up and control for confounding factors are needed to obtain more convincing evidence.

Adolescent↗

PubMed2001

Risk for anogenital cancer and other cancer among women hospitalized with gonorrhea.

BACKGROUND: We investigated the relationship between infections with Neisseria gonorrhoeae and anogenital and other cancers. METHODS: Nationwide and population based register linkage study utilizing prospectively notified information. The observed numbers of cancers among the women were compared with those expected on the basis of national incidence rates. RESULTS: In a cohort of 4440 women hospitalized for gonorrhea we observed a total of 227 cases of cervical intraepithelial neoplasia grade III (CIN III), with 103 expected (standardized incidence ratio (SIR), 2.2; 95% confidence interval (CI), 1.9-2.5). No significantly increased risk for other anogenital cancers or cancer at other sites was seen. CONCLUSIONS: These results support the view that the observed association between gonorrheal infection and subsequent cervical preneoplasia is due mainly to surveillance bias. However, our results also indicate that women hospitalized with a N. gonorrhoeae infection will benefit from the compliance with the regular Pap smear screening programs.

Adolescent↗

PubMed2001

Modulation of keratinocyte gene expression and differentiation by PPAR-selective ligands and tetradecylthioacetic acid.

Peroxisome proliferator-activated receptors (PPARs) are pleiotropic regulators of growth and differentiation of many cell types. We have performed a comprehensive analysis of the expression of PPARs, transcriptional cofactors, and marker genes during differentiation of normal human keratinocytes using a combination of reverse transcriptase polymerase chain reaction, Northern and Western blotting, and immunohistochemistry. PPARdelta was the predominant PPAR subtype in human keratinocytes and highly expressed in basal cells and suprabasal cells. Induction of PPARalpha and PPARgamma expression was linked to differentiation, and accordingly, expression of PPARalpha and PPARgamma was in essence confined to suprabasal cells. Differentiation was not accompanied by significant changes in the expression of the coactivators CREB-binding protein, p300, steroid receptor coactivator 1, or the corepressors nuclear receptor corepressor and silence mediator for retinoid and thyroid hormone receptors. We critically evaluated the effects of selective PPAR ligands and a synthetic fatty acid analog, tetradecylthioacetic acid. Tetradecylthioacetic acid activated all human PPAR subtypes in the ranking order PPARdelta >> PPARalpha > PPARgamma. All selective PPAR ligands marginally induced transglutaminase-1 expression with the PPARdelta-selective ligand L165041 being the most potent. The PPARalpha- and PPARgamma-selective ligands Wy14643 and BRL49653 had negligible effect on involucrin expression, whereas a dose-dependent induction was observed with L165041. Simultaneous addition of L165041 and BRL49653 synergistically induced strong involucrin expression. Additionally, L165041 potently induced CD36 mRNA expression. Administration of tetradecylthioacetic acid resulted in a dramatic decrease in proliferation and a robust upregulation of the expression of involucrin and transglutaminase. Our results indicate that tetradecylthioacetic acid may affect keratinocyte gene expression and differentiation via PPAR-dependent and PPAR-independent pathways, and that the latter play an important role.

Adult↗

PubMed2001

Appendectomy and subsequent risk of inflammatory bowel diseases.

BACKGROUND: Case-control studies have reported an inverse relationship between appendectomy and the risk of ulcerative colitis, but the association has not been confirmed in prospective studies. METHODS: Using national hospital discharge registry data in Denmark, the authors followed up 154,434 patients who underwent appendectomy during the period 1977 to 1989 to investigate whether they had subsequent hospitalizations for ulcerative colitis and Crohn's disease. Ratios of observed-to-expected first hospitalizations for inflammatory bowel diseases served as measures of the relative risk (RR). RESULTS: Hospitalization for ulcerative colitis occurred in 84 patients who had appendectomies versus 97.0 expected (RR = 0.87; 95% CI, 0.69-1.07). RRs were not significantly reduced in subgroups defined by sex, age, time since appendectomy, calendar period, or cause of appendectomy. Hospitalization for Crohn's disease occurred in excess (RR = 2.88; 95% CI, 2.45-3.39; n = 150), notably in the first year after appendectomy (RR = 10.83; 95% CI, 8.49-13.62; n = 73); but after 5 years, the RR was not significantly elevated. CONCLUSIONS: This large population-based cohort study failed to support a significant inverse association between appendectomy and ulcerative colitis risk in the first decade after the operation. The excess of Crohn's disease shortly after appendectomy most likely reflects differential diagnostic problems in patients newly presenting with abdominal pain.

Adult↗

PubMed2001

Shewanella putrefaciens adhesion and biofilm formation on food processing surfaces.

Laboratory model systems were developed for studying Shewanella putrefaciens adhesion and biofilm formation under batch and flow conditions. S. putrefaciens plays a major role in food spoilage and may cause microbially induced corrosion on steel surfaces. S. putrefaciens bacteria suspended in buffer adhered readily to stainless steel surfaces. Maximum numbers of adherent bacteria per square centimeter were reached in 8 h at 25 degrees C and reflected the cell density in suspension. Numbers of adhering bacteria from a suspension containing 10(8) CFU/ml were much lower in a laminar flow system (modified Robbins device) (reaching 10(2) CFU/cm(2)) than in a batch system (reaching 10(7) CFU/cm(2)), and maximum numbers were reached after 24 h. When nutrients were supplied, S. putrefaciens grew in biofilms with layers of bacteria. The rate of biofilm formation and the thickness of the film were not dependent on the availability of carbohydrate (lactate or glucose) or on iron starvation. The number of S. putrefaciens bacteria on the surface was partly influenced by the presence of other bacteria (Pseudomonas fluorescens) which reduced the numbers of S. putrefaciens bacteria in the biofilm. Numbers of bacteria on the surface must be quantified to evaluate the influence of environmental factors on adhesion and biofilm formation. We used a combination of fluorescence microscopy (4',6'-diamidino-2-phenylindole staining and in situ hybridization, for mixed-culture studies), ultrasonic removal of bacteria from surfaces, and indirect conductometry and found this combination sufficient to quantify bacteria on surfaces.

Bacterial Adhesion↗

PubMed2000

Crohn's disease and cancer risk (Denmark).

OBJECTIVES: The large number of studies of intestinal cancer among patients with Crohn's disease have provided inconsistent risk estimates in regard to risk of both colorectal and small intestinal cancer. We investigated incidence of cancer among Crohn's disease patients in comparison with the incidence in the general population of Denmark. METHODS: From the Danish National Registry of Patients we identified 2645 patients who had been hospitalized with Crohn's disease during 1977-1989. Cancer incidence for up to 17 years was determined in the cohort and compared to an expected number derived from national cancer incidence rates. RESULTS: The 15 observed cases of colorectal cancer were close to the expected number of 13.1 (SIR = 1.1; 95% CI 0.6-1.9), whereas the five cases of small intestinal cancer (three adenocarcinomas and two carcinoids) observed corresponded to an 18-fold increased risk (SIR = 17.9; 95% CI 5.8-42). CONCLUSIONS: A potential excess of colorectal cancer among subgroups of patients with Crohn's disease was not detectable in the overall risk estimate for colorectal cancer. Only for small intestinal cancer was a significantly elevated risk found among these patients hospitalized with Crohn's disease.

Adenocarcinoma↗

PubMed2000

A cross-sectional study of dietary habits and urinary glucose excretion - a predictor of non-insulin-dependent diabetes mellitus.

OBJECTIVE: To investigate the association between consumption of certain foods and macronutrients and urinary glucose excretion, which is a predictor of non-insulin-dependent diabetes mellitus. DESIGN: A cross-sectional study, Denmark, 1993-97. SUBJECTS: Participants in the Danish study 'Diet, Cancer and Health'. After exclusion of persons with postprandial urine samples and persons with diabetes or other diseases potentially resulting in glycosuria, the study population included 14 743 men and 18 064 women aged 50-64 y. We identified 183 men and 43 women with glucose in their urine. RESULTS: Consumption of poultry was negatively associated with glycosuria in both men (odds ratio, OR=0.87; 95% confidence interval, 95% CI=0.77-0.98) and women (OR=0.69; 0.48-1.00). Fiber from fruit showed a weak negative association with glycosuria in both men (0. 95; 0.90-1.01) and women (0.89; 0.78-1.02), whereas a significant negative association with total fiber (0.68; 0.51-0.91) and fiber from vegetables (0.94; 0.88-0.99) was seen in men. Intake of fish tended to reduce the risk of glycosuria in women only (0.80; 0.63-1. 02), whereas ingestion of milk products increased their risk significantly (1.15; 1.06-1.24). CONCLUSION: Although statistical significance and consistency in the two sexes were not achieved for all end-points, the study indicates a protective effect of dietary products like poultry, fruit and cereals against glycosuria and suggests a promoting effect of milk. SPONSORSHIP: The Danish National Board of Health and the Danish Cancer Society.

Animals↗

PubMed2000

1alpha,25-dihydroxyvitamin D3 induced differentiation of cultured human keratinocytes is accompanied by a PKC-independent regulation of AP-1 DNA binding activity.

1alpha,25(OH)2D3 and its analogs are potent mediators of keratinocyte differentiation in vitro. The precise mechanism of this action is still unknown. The nuclear transcription factor activator protein 1 seems to play an important role in keratinocyte differentiation. The purpose of this study was to investigate the effect of 1alpha,25(OH)2D3 on activator protein 1 DNA binding activity in cultured human keratinocytes. In a time-course study of human keratinocytes incubated with 1alpha,25(OH)2D3 (10-7-10-11 M) a significant dose-dependent increase in activator protein 1 DNA binding activity as determined by electrophoretic mobility shift assay was seen after 36 h. This increase was followed by a significant dose-dependent decrease in activator protein 1 DNA binding activity after 72 h. When differentiation was induced by raising the calcium concentration in the culture medium from 0.09 to 0.3 mM a similar increase in activator protein 1 DNA binding activity was observed after incubation for 48 h. Pharmacologic down-modulation of the protein kinase C activity with GF 109203X reversed the calcium-induced increase in activator protein 1 DNA binding activity and abolished keratinocyte differentiation as determined by a transglutaminase assay. In contrast, activator protein 1 DNA binding activity and keratinocyte differentiation were not affected when protein kinase C activity was down-modulated in the experiments with 1alpha,25(OH)2D3. The activator protein 1 complex in human keratinocytes consists of dimers of Fra-1, Fra-2, c-Jun, JunD, and c-Fos. Our results demonstrate that 1alpha, 25(OH)2D3- and calcium-induced keratinocyte differentiation are accompanied by changes in activator protein 1 DNA binding activity. Protein kinase C activation appears to be essential for the calcium-dependent induction of keratinocyte differentiation, whereas a protein-kinase-C-independent activation of activator protein 1 DNA binding and keratinocyte differentiation is responsible for the 1alpha,25(OH)2D3-induced effects.

Calcitriol↗

PubMed2000

Anal carcinoma in inflammatory bowel disease.

We followed 9602 patients with Crohn's disease or ulcerative colitis for anal squamous cell carcinoma for up to 18 years. No significant increase was observed: two cases occurred vs 1.3 expected during 99,229 person-years of observation, (standardized incidence ratio = 1.6; 95 confidence interval: 0.2-5.7). Anal squamous cell carcinoma is rare even in inflammatory bowel disease.

Adult↗

PubMed2000

Antidepressant medications and risk for cancer.

Antidepressants appear to promote tumor growth in experimental studies; however, results from epidemiologic studies are inconclusive. We used a population-based cohort study to estimate the incidence of cancer after antidepressant treatment in 39,807 adult users of antidepressants identified in the Prescription Database of the County of North Jutland, Denmark between January 1, 1989 and December 31, 1995. Information on cancer occurrence was obtained from the Danish Cancer Registry. We categorized exposure according to use of tricyclic antidepressants, tetracyclic antidepressants, selective serotonin reuptake inhibitors, or monoamine oxidase inhibitors. In the follow-up period beginning 1 year after first known prescription, there were 966 cancers among users of antidepressants; our population estimate suggested an expected number of 946 for an overall standardized incidence ratio of 1.0 (95% confidence interval = 1.0-1.1). Users of tricyclic antidepressants had an excess of non-Hodgkin's lymphoma, with the risk increasing with the number of prescriptions of tricyclic antidepressants. The standardized incidence ratio was 2.5 (95% confidence interval, 1.4-4.2) for those with five or more prescriptions. Our results provide little evidence that antidepressants promote cancer at other sites, except for a possible effect of tricyclic antidepressants and tetracyclic antidepressants on non-Hodgkin's lymphoma.

Antidepressive Agents↗

PubMed2000

Exposure to electromagnetic fields and risk of central nervous system disease in utility workers.

Occupational exposure to electromagnetic fields has been associated with neurological diseases such as amyotrophic lateral sclerosis, senile dementia, Parkinson disease, and Alzheimer disease. I studied the incidence of central nervous system diseases in 30,631 persons employed in Danish utility companies between 1900 and 1993. I linked the cohort to the nationwide, population-based Danish National Register of Patients and compared the numbers of cases of these diseases observed between 1978 and 1993 with the corresponding rates in the general population. In addition I fit to the data on utility workers a multiplicative Poisson regression model in relation to estimated levels of exposure to 50-Hz electromagnetic fields. Overall, there was an increase in risk for senile dementia and motor neuron diseases combined. The incidences of Parkinson disease, Alzheimer disease, and other diseases of the central nervous system were essentially unrelated to exposure to electromagnetic fields. A decreased risk of epilepsy compared with the general population probably reflects a healthy worker effect; I observed an increased risk of epilepsy based on internal comparisons. The increased risk for senile dementia and motorneuron diseases may be associated with above-average levels of exposure to electromagnetic fields.

Adult↗