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Biomedical subjects

H Johansen

Publications and source records attributed to H Johansen.

At least 19 recordsLinked to original sources
PubMed1992

An investigation of the increase in preschool-age asthma in Manitoba, Canada.

Asthma has long been a major cause of illness and disability among young Canadians. From 1970-71 to 1987-88, hospital admissions for asthma increased significantly among Canadian children under the age of fourteen. Many hypotheses may explain this increase in asthma prevalence. There could be a true increase in the number of people developing symptoms of the disease or increased asthma rates could be an artifact due to changes in detection, diagnosis, treatment, or coding. This study reviews hypotheses put forward to explain the increase in asthma prevalence, and tests some of them in Manitoba for children aged 0-4. Physician claims data and hospital separation data were merged to create unique person oriented medical records. These records were used to estimate the number of children seeking medical services for asthma during a five-year period (1984-85 to 1988-89) and the change in rates over this time period. From 1984-85 to 1988-89, both prevalence and incidence rates for children less than five years of age increased. Prevalence rates showed strong seasonal peaks in the spring and the fall. There is no indication that asthma increased in severity. The hospitalization rate (the number visiting a hospital for asthma divided by the total number seeking medical care for asthma), the average number of hospital admissions per year, and the average number of days spent in a hospital per year did not increase. Levels of ozone (O3) and nitrogen dioxide (NO2) in downtown Winnipeg increased over the study period and asthma prevalence increased twice as fast in Winnipeg as in the rest of the province. For Manitoba, the increase in preschool-aged asthma does not appear to be due to increased use of medical services, a change in ICD coding, an increase in the severity of the cases, or a decrease in income levels. The increases appear to be at least partly due to changes in diagnostic practices. The relationship between asthma and air pollution needs more detailed study as pollution is likely to be an important factor, particularly during the spring. Other areas for further investigation are changes in allergy and virus precursors, maternal smoking, and increased levels of pollens, molds and dust mites.

Abstracting and Indexing↗
PubMed1991

Comparison of several promoters and polyadenylation signals for use in heterologous gene expression in cultured Drosophila cells.

We have directly compared the ability of four promoters and three polyadenylation (poly(A)) signals to direct heterologous gene expression in stably transfected Drosophila melanogaster S2 cells. We compared two constitutive Drosophila promoters, the actin 5C distal promoter and the alpha 1-tubulin promoter, with the tightly regulated Drosophila metallothionein (Mtn) promoter and the Bombyx mori fibroin promoter. We find that the actin 5C and induced Mtn promoters generate comparable high levels of RNA and protein in this system. The alpha 1-tubulin promoter generates about four-fold lower levels, and the fibroin promoter shows no detectable activity in S2 cells. Interestingly, genes expressed from the constitutive actin 5C and alpha 1-tubulin promoters are consistently present at three- to four-fold lower copy numbers than genes expressed from the inducible Mtn promoter or the inactive fibroin promoter. Poly(A) signals of both mammalian (SV40) and Drosophila (Mtn) origin efficiently directed stable RNA synthesis in S2 cells, and, as in mammalian cells, the SV40 late poly(A) signal was more efficient than the SV40 early poly(A) signal. Thus the process of polyadenylation appears to be conserved between mammalian and Drosophila cells.

Actins↗
PubMed1991

Regulated expression allows high level production and secretion of HIV-1 gp120 envelope glycoprotein in Drosophila Schneider cells.

We have established a stable, continuous culture Drosophila Schneider 2 cell line that efficiently expresses a secreted, truncated form of the HIV envelope gp120 protein in a regulated manner. The Drosophila produced recombinant gp120 protein is highly glycosylated, is recognized by gp120-specific monoclonal antibodies, binds to the CD4 receptor and has the ability to inhibit syncytia formation between uninfected CD4+ cells and HIV infected cells. We conclude that this recombinant Drosophila envelope protein is an appropriate mimic of the authentic viral envelope protein. Thus, the Drosophila cell provides a continuous, stable culture system for the efficient expression of secreted forms of complex surface glycoproteins in quantities sufficient for detailed analyses.

Amino Acid Sequence↗
PubMed1990

[Sarcoma treatment in Denmark].

Approximately 240 sarcomas are registered annually in Denmark. Of these, 5/6 are soft-tissue sarcomas while the remainder consist of various types of sarcomas of bone. Determination of the histogenetic type, the degree of aplasia and the anatomical spread of the primary tumour is decisive for optimal prognostic assessment and for planning of the primary local treatment. The surgical treatment is aimed at radical treatment and, where tumours in extremities are concerned, this frequently involves reconstruction with endoprostheses with the object of salvaging the limb. Irradiation is indicated in cases of soft-tissue sarcoma which are not amenable to radical operation and as palliative treatment. In cases of soft-tissue sarcoma, cytostatic therapy with adriamycin alone or combined with iphosphamide in metastasizing disease can result in response in 30-50% of the patients. On the other hand, the value of adjuvant treatment is not yet elucidated. In cases of osteogenic sarcoma, the data available at present suggest that prolongation of the survival rate may be obtained by means of intensive adjuvant cytostatic treatment, but the optimal regimen is not yet defined. In other situations, cytostatic therapy must be considered as experimental and not indicated outside the fields of controlled investigations. Optimal diagnosis and treatment of sarcoma requires extensive multidisciplinary contributions which should be centralized in the fewest possible centres. Intimate national and international cooperation is also essential.

Antineoplastic Agents↗
PubMed1990

Evaluation of radiotherapy in high-risk breast cancer patients: report from the Danish Breast Cancer Cooperative Group (DBCG 82) Trial.

The role of postmastectomy irradiation together with systemic treatment was evaluated in high-risk patients included in the Danish Breast Cancer Cooperative Group (DBCG) protocol 82. As of June 1989, a total of 1473 pre- and menopausal patients were randomized to postmastectomy irradiation + CMF versus CMF alone (protocol 82-b). A total of 1202 postmenopausal patients were randomized to postmastectomy irradiation + Tamoxifen versus Tamoxifen alone (protocol 82-c). At 5 years the actuarial loco-regional recurrence rate was significantly lower in the irradiated patients (82-b: 9% vs 28%, 82-c: 6% vs 36%). Further, disease-free survival was significantly improved in both pre- and postmenopausal irradiated patients compared with those who had only systemic treatment (82-b: 54% vs 47%, 82-c: 52% vs 38%). At present, overall survival is significantly different in 82-b patients (68% vs 63%) but not in post-menopausal 82-c patients (62% vs 61%). Thus, adjuvant systemic treatment alone (chemotherapy or tamoxifen) did not prevent loco-regional recurrences in high-risk patients after mastectomy and axillary lymph node sampling. However, a longer observation time is necessary to evaluate the consequence of primary optimal loco-regional tumor control in high-risk breast cancer patients with respect to overall survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1990

Simple mastectomy with postoperative irradiation versus extended radical mastectomy in breast cancer. A twenty-five-year follow-up of a randomized trial.

From November 1951 to December 1957, all patients with untreated breast cancer admitted to the Radium Centre in Copenhagen were randomized before their operability was evaluated into two groups, if the patients were operable, viz. simple mastectomy with postoperative x-ray treatment or extended radical mastectomy. Twenty-five-year results are presented, showing no difference in survival or recurrence-free survival of the operable patients. Histological grading was performed in nearly all cases. Patients with grade 1 tumours had a better survival than grades 2 and 3, but there was no difference in survival between the two treatment groups, when histological grading was taken into account. Histological node positive patients had more grades 2 and 3, tumours, whereas node negative patients had more grade 1 than grades 2 and 3 tumours. Premenopausal women had a significantly better survival than postmenopausal in all stages.

Age Factors↗
PubMed1990

Canadian suicide mortality rates: first-generation immigrants versus Canadian-born.

This article examines suicide mortality rates and trends in Canada for first-generation immigrants and the Canadian-born population. Data are analyzed by age, sex and country of birth. Since 1950, suicide rates worldwide for both men and women have been increasing. In North America and most of Europe, suicide has been one of the major causes of death for many years. In Canada, suicide rates are also rising. However, this increase is due entirely to a rise in the rate for men; the rate for women has remained relatively stable. Several differences are apparent between the rates for the Canadian-born population and those for first-generation immigrants. For example, three times as many Canadian-born men as women commit suicide. For first-generation immigrants, the ratio is two to one. Suicide mortality rates for the Canadian-born are higher than those for first-generation immigrants in every age group except for the 65 and over groups. Canadian born males have higher ASMR than first generation immigrant males. The rates for women show that first-generation immigrant women have higher suicide mortality rates than their Canadian-born counterparts, and that the highest rate for all women is for immigrants born in Asia.

Adolescent↗
PubMed1990

Canadian cardiovascular disease mortality: first generation immigrants versus Canadian born.

Cardiovascular disease (CVD) is the major cause of death in Canada, as it is in most industrialized countries. Studies have shown that CVD mortality rates vary among ethnic groups. Since about one in six Canadian residents is a first generation immigrant, it is important to consider ethnic background when interpreting Canadian health statistics or planning health services. Overall, lower CVD mortality rates were found for first generation Canadians from Latin America, China and South Asia; higher rates are indicated for those from Scandinavia and Africa. The rates for North America are similar to those found for Eastern and Western Europe. Between two five-year time periods (1969-73 and 1984-88), CVD mortality rates generally were found to decrease, except for immigrants from Africa (age 35+). The rates were consistently higher for males than for females.

Adult↗
PubMed1990

Acute myocardial infarction. A feasibility study using record-linkage of routinely collected health information to create a two-year patient profile. Manitoba, 1984-85 and 1985-86.

Manitoba's hospital separations and physician medical files were linked for the fiscal years 1984-85 and 1985-86. The result was a study file consisting of records for 5,293 males and 3,143 females, who, during this period, suffered an Acute Myocardial Infarction (AMI), commonly called a heart attack. Merging the two types of files created a comprehensive data base for these AMI victims. The Manitoba age-sex standardized AMI rate was 38.0 per 10,000 population. Age-specific rates were higher for males than for females for all age groups. Hospitalized cases accounted for 7,201 individuals or 85.4% of AMI victims. Age-sex standardized rates of hospitalization per 10,000 population ranged from 27.1 in the Central region to 36.0 in the Westman region. The Manitoba age-specific rates of hospitalization for males in the 35-54 and 55-64 age groups were about three times the female rates for the same age groups. One quarter of AMI hospitalized victims died in hospital. The Manitoba age-specific death rates for males in the 35-54, 55-64 and 65-74 age groups were double the rates for females in the same age groups. Of the 8,436 AMI victims under study, 86.4% had at least one other concurrent medical condition such as angina, other forms of ischemic heart disease, diabetes, or hypertension. Of AMI victims, 93.8% underwent at least one of the following procedures: coronary artery bypass surgery, angiogram, electrocardiogram, cardiac catheterization, arteriography, or blood cholesterol testing. A higher percentage of procedures was performed on males than on females.

Acute Disease↗
PubMed1989

Regulated expression at high copy number allows production of a growth-inhibitory oncogene product in Drosophila Schneider cells.

The Drosophila metallothionein promoter (Mtn) was used to obtain efficient, regulated expression of foreign gene products inserted in high copy numbers into Drosophila melanogaster Schneider 2 cells. An expression unit comprised of a reporter gene [Escherichia coli galactokinase (galK)] fused to the Mtn promoter was stably introduced into Schneider 2 cells in up to several hundred copies per cell in a single transfection-selection event. This system contrasts dramatically with other eukaryotic systems that permit only a few copies of a gene to be stably inserted in a single transfection-selection event. The transfected Drosophila S2 cell lines expressed high levels of both galK mRNA and protein in response to metal induction. Most important, and in contrast to mammalian cells, expression remained fully regulated even at high copy number, with low basal expression maintained in the absence of inducer. This regulated system was used to obtain efficient expression in Drosophila cells of an otherwise lethal or growth-inhibitory gene product, the human H-ras oncogene. The ability to obtain regulated high-level expression of potentially lethal foreign proteins is unique to the Drosophila cell system.

Animals↗
PubMed1989

The effect of thoracic irradiation for cancer of the breast on ventilation, perfusion and pulmonary permeability. A one-year follow-up.

Regional and overall lung function was studied in 14 women during a one-year follow-up after postmastectomy irradiation for cancer of the breast. The dose was 40 Gy in the chest wall and 20-40 Gy in the apex of the lung. Immediately after irradiation there was a slight increase in pulmonary clearance of 99TCm-DTPA compared to baseline values. This increase, however, was not restricted to the field of irradiation. Three months after irradiation there were regional defects in the ventilation and perfusion scintigrams in 11 of the patients. At the same time there was a greater decrease in total lung capacity, vital capacity and diffusion capacity for CO than in ventilation and perfusion. One year after irradiation the lung function impairment had only insignificantly regressed. It is concluded that local lung irradiation may cause persistent regional and generalized lung function impairment. The early increase in pulmonary clearance of 99Tcm-DTPA could not be used as a predictor of subsequent lung function impairment.

Adult↗
PubMed1988

Prognostic factors in osteosarcomas. A regression analysis.

A multivariate regression analysis of survival data, using the Cox proportional hazards model (PHM), was performed on the retrospective material of 184 osteosarcoma patients treated at the Aarhus and Copenhagen oncology centers, Denmark, from 1963 to 1984. All patients were previously untreated. Radical surgery, in general ablative when possible, was the primary treatment goal throughout this period. A number of clinical and pathologic variables were tested in the model to elucidate their prognostic importance. Tumors localized to the trunk, pelvis, or femur, and symptom duration of less than 6 months were poor prognostic signs. Tumors dominated by fibroblastic cells and a patient age of approximately 25 to 30 years were associated with an especially good prognosis. The prognosis worsened with advancing age. Children, adolescents, and adults ages 5 to 25 years had significantly poorer prognosis than young adults 25 to 30 years of age. Sex, radiologic appearance, and year of referral had no significant prognostic value in this series. Based on the regression model, a prognostic index is derived and survival is calculated for a good and a poor prognostic case. The overall 10-year survival with one standard deviation was 28.6 +/- 3.5%. Cancer deaths continue to occur 10 years after initial treatment, and the estimated hazard rate is still four times greater than that of a sex- and age-matched group of healthy individuals.

Adolescent↗
PubMed1988

Major risk factors for cardiovascular disease mortality in adults: results from the Nutrition Canada Survey cohort.

The cardiovascular mortality experience of over 7000 Canadians ages 35-79 years free of self-reported heart disease or stroke who participated in the Nutrition Canada survey is presented. The effects of various risk factors on cardiovascular disease mortality were assessed using multivariate Poisson regression analyses. Factors associated with a significantly increased risk of dying included cigarette smoking, hypertension, diabetes and, for women, serum cholesterol. Relative risks were similar for those ages 35-64 years compared to those 65-79 years for diabetes but were higher among those 35-64 years for cigarette smoking, diastolic hypertension, obesity and serum cholesterol (females only). Individuals drinking three or more drinks daily had a relative risk of 3.18 for stroke. Population attributable risks for smoking, hypertension, elevated serum cholesterol and diabetes, respectively, were 47%, 21%, 7% and 8% for men and 10%, 21% 18% and 16% for women.

Adult↗
PubMed1988

Postmastectomy irradiation in high-risk breast cancer patients. Present status of the Danish Breast Cancer Cooperative Group trials.

All pre- and postmenopausal high-risk breast cancer patients in the protocols DBCG 77 of the Danish Breast Cancer Cooperative Group received postmastectomy irradiation before randomization to either adjuvant systemic therapy or no such treatment. The actuarial loco-regional recurrence rate at 9 years was 6-17%, with the lowest rate in patients who also received additional adjuvant chemotherapy or tamoxifen. In a subsequent study (DBCG 82) the role of postmastectomy irradiation together with systemic treatment was evaluated in high-risk patients. Pre- and menopausal patients were randomized to postmastectomy irradiation + CMF (cyclophosphamide, methotrexate, 5-fluorouracil), CMF alone or CMF + TAM (tamoxifen). Postmenopausal patients were randomized to postmastectomy irradiation + TAM, TAM or CMF + TAM. At 4 years the loco-regional recurrence rate was significantly lower in the irradiated patients (5-7% vs. 23-33%). Further, disease-free survival was significantly improved in both pre- and postmenopausal irradiated patients compared with those who had only systemic treatment. At present, there are no significant differences between survival in the treatment groups. Thus, adjuvant systemic treatment alone (chemotherapy and/or tamoxifen) did not prevent loco-regional recurrences in high-risk patients after mastectomy and axillary lymph node sampling. However, a longer observation time is necessary to evaluate the consequence of primary optimal loco-regional tumour control in high-risk breast cancer patients with respect to survival.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1987

Important risk factors for death in adults: a 10-year follow-up of the Nutrition Canada survey cohort.

Data on mortality among over 8000 Canadians aged 35 to 79 years who participated in the Nutrition Canada survey are presented. The effects of various risk factors on mortality were assessed with a multivariate Poisson regression analysis. Factors associated with a significantly increased risk of death over a 10-year follow-up period ending in 1981 included cigarette smoking, hypertension and diabetes mellitus. A shallow U-shaped mortality pattern was observed for body mass index and for serum cholesterol level. No statistically significant increases in risk were associated with alcohol consumption. The population attributable risks for smoking, hypertension and diabetes were 39%, 8% and 6% respectively for men and 21%, 12% and 7% respectively for women.

Adult↗