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R Skjaerven

Publications and source records attributed to R Skjaerven.

90 records · Page 5Linked to original sources
PubMed1987

Parity specific perinatal mortality. A longitudinal study based on sibships.

Perinatal mortality in sibships has been examined using the Medical Birth Registry of Norway. Using linear logistic regression, parity specific perinatal mortality in the period 1967-1981 has been analysed, controlling simultaneously for maternal age, year of birth and survival of earlier births. The risk of a perinatal loss was increased by a factor of up to 6.0 following one earlier perinatal loss, and with three earlier losses the increase was 17.0. The general reduction in mortality between the different five year periods varied according to parity and maternal age. No secular reduction in risk, however, was demonstrated in sibships where the first birth died perinatally; for some subgroups of women the risk actually increased between the first and the second five year period. The effect of maternal age changed with parity, being strong in the first birth order, but of no effect either for the third or the fourth birth orders once the perinatal survival of earlier births was controlled for. This study shows the need to take heterogeneity of risk between women into account in studies of perinatal loss; the overall improvement in perinatal mortality does not apply to every woman. As care improves, perinatal losses become less and less random, demonstrated by increased risks of recurrence.

Adolescent↗
PubMed1986

Sudden infant death syndrome and post perinatal mortality in Norwegian birth cohorts 1967-1980.

The well established effects of maternal age and birth order in sudden infant death syndrome (SIDS) formed the basis for a comparison with other categories of post perinatal death in an attempt to shed some light on the etiologic roles played by ante and postnatal factors. A total of 826,162 children, born 1967 through 1980 and recorded at the Medical Birth Registry of Norway was at risk to die during the post perinatal period (ages 7 through 364 days). Out of the 3,582 infants who died, 1,062 were considered SIDS. Strong effects of maternal age (negative) and birth order (positive) were found in the SIDS group, but not to the same extent in the non-SIDS group or the group of congenital malformations. Likewise, the excess risk in children of unmarried mothers was higher in the SIDS group. The suggested effects of postnatal factors in the causation of SIDS may seem promising from a preventive point of view. The strength of the effects of maternal age and birth order necessitate adjustment for these variables in future epidemiological studies of SIDS.

Birth Weight↗
PubMed1986

A case-referent study of lung cancer, occupational exposures and smoking. III. Etiologic fraction of occupational exposures.

The proportion of lung cancer related to occupational exposure to respiratory carcinogens and other workplace contaminants has been studied in a hospital-based case-referent study of 176 incident cases and 176 referents, recruited from the medical ward of two county hospitals in southern Norway. On the basis of job title and exposure information, three different approaches for the estimation of etiologic fraction were used, all based upon a trichotomous categorization of the exposure variable. Among the definitely exposed subjects, the etiologic fraction for lung cancer related to occupational exposure factors was from 22 to 35%, increasing to 37-47% when the "possibly exposed" categories were included. When asbestos was the only factor to be eliminated, the etiologic fraction estimate suggested a 23% reduction in the lung cancer incidence in the study population. More than 90% of the lung cancer cases would theoretically have been prevented if smoking had been completely removed. The relative merits of preventing one or several of the study factors simultaneously is discussed.

Adult↗
PubMed1986

A case-referent study of lung cancer, occupational exposures and smoking. II. Role of asbestos exposure.

In a hospital-based case-referent study of 176 incident lung cancer cases, ascertained during a five-year period from two county hospitals, the role of asbestos exposure and smoking has been studied. Information on asbestos exposure was obtained from personal interviews, and allocated to four exposure categories, according to the intensity and duration of the exposure. Twenty-five percent of the cases and 10% of the referents had been moderately to heavily exposed to asbestos during their working career. A statistically significant trend in risk ratio related to the degree of exposure was observed, with a more than fourfold risk among the heavily exposed. The strongest association was found between asbestos exposure and small cell carcinoma, and the weakest association between asbestos exposure and adenocarcinoma. Very high risk ratios were observed among asbestos-exposed subjects who were heavy smokers, and the interaction observed between asbestos and smoking conformed more closely to a multiplicative model than to an additive one. The results suggest that the observed association between lung cancer and occupational exposures in this study was, to a large extent, due to asbestos exposure. Information on such exposure was missing in 90% of the medical records of these patients.

Adult↗
PubMed1986

A case-referent study of lung cancer, occupational exposures and smoking. I. Comparison of title-based and exposure-based occupational information.

The role of occupational exposures and smoking in the development of lung cancer has been studied among 176 male incident lung cancer cases and 176 referents admitted to two county hospitals in southeast Norway during 1979-1983. After the allocation of all occupational titles in the Nordic Classification of Occupations into three exposure groups according to potential exposure to respiratory carcinogens and other contaminants, each subject was classified according to exposure status of main occupation and number of years in each exposure category. An excess risk of lung cancer was observed both among those in possibly exposed occupations and among those definitely exposed. A more than threefold excess risk was observed among subjects with more than 30 years in exposed occupations. Exposure to 22 agents/processes was further assessed by a separate questionnaire and estimated simultaneously in a logistic regression model. Elevated risks were associated with exposure to asbestos and several other agents/processes, which largely correlated to each other. Smoking was strongly associated with all histological subtypes of lung cancer, while for occupational exposures the risk ratio was highest for small cell carcinoma and lowest for adenocarcinoma. Very high risk ratios for lung cancer were observed among heavy smokers in exposed occupations.

Adult↗
PubMed1985

Secular trends in age at onset, sex ratio, and type index in leprosy observed during declining incidence rates.

Epidemiologic surveillance in Norway, the United States, Nigeria, Japan, Venezuela, India, and China, covering periods from 1851 to 1981, demonstrates a consistent decline in incidence rates of leprosy. At the same time, secular trends have been observed which imply an increasing age at onset, an increasing male excess, and an increasing fraction of new cases represented by multibacillary leprosy. Theoretically, an increasing age at onset may be caused by two mechanisms, namely postponement of infection to a later age and/or an increasing fraction of patients with long incubation periods. Cohort analyses have shown no increase in age at onset in subsequent birth cohorts, but rather have shown a decrease. The latter mechanism, the increasing importance of long incubation periods, is consistent with the shift toward multibacillary cases in which the incubation period is longer than that in paucibacillary cases. Apparently, this mechanism has also been present during the decline of tuberculosis. An increasing fraction of new patients with long incubation periods, resulting in an increasing age at onset, is proposed as a general principle to be expected in any disease in rapid decline which also has a long and varying incubation period. This theory offers a basis for assessment of secular trends.

Adolescent↗
PubMed1985

Measurement of local blood flow in acute myocardial infarction: loss of 15-micron microspheres during the first hour.

Distribution of radiolabelled microspheres is widely utilized for determination of regional blood flow in experimental myocardial infarction studies. The purpose of this investigation was evaluation of the microsphere method during 1 h of regional ischaemia. Special attention was focused upon loss of preocclusion microspheres from ischaemic myocardium; mechanisms for loss and blood flow distribution in non-ischaemic left ventricle. Microspheres (15 micron) were injected into the left atrium in nine pentobarbital anaesthetized cats prior to coronary artery occlusion and again after 1 h of occlusion. Preocclusion blood flow estimates were lower in ischaemic compared with non-ischaemic myocardium (1.36 vs. 1.62 cm3 X min-1 X g-1, P = 0.002), corresponding to 16% apparent loss. In endocardial ischaemic tissue, development of oedema could account for the loss. In epicardial ischaemic tissue, oedema was not present and loss was therefore due to migration of microspheres. Epicardial loss increased in proportion to restoration of left ventricular contractility. There was no evidence for significant microsphere loss through lymphatic pathways. In non-ischaemic left ventricular tissue, myocardial blood flow was evenly distributed from apex to base, and also between endocardial and epicardial layers. This study quantitates an important limitation to measurements of local blood flow in ischaemic myocardium by radiolabelled microspheres.

Animals↗
PubMed1984

Prediction of prognosis in axillary lymph node positive breast cancer patients: a statistical study.

This work has identified variables of importance to short- and long-term prognosis in 97 node positive breast cancer patients followed for a minimum of 98 months. The diameter of the primary tumour (less than or equal to 3 cm/greater than 3 cm) is shown to be an important prognostic variable. Its addition to the presence/absence of tumour cells in the efferent nodal vessels and the mean nuclear area of the tumour cells gave correct prediction of the disease outcome, 60 and 98 months after the operation, in 83 and 80 per cent of the patients respectively. Although the number of tumour-bearing nodes is shown to be a strong variable, more information was gained from the tumour diameter. Histological grade was only of value for 5-year prognosis. Factors that did not add information of prognostic value in these circumstances were identified. The proposed models demonstrate the great heterogeneity within this group of patients.

Adult↗
PubMed1984

Prospective assessment of recurrence risk in sudden infant death syndrome siblings.

Knowledge of the likelihood of a repetition of sudden infant death syndrome within a sibship, particularly in the next sibling, is important to parents. Methodologic considerations with respect to the studies of recurrence risk already published indicate that the rates reported are overestimates. This suspicion is confirmed by our study based on 826,162 infants surviving the first week of life on file in the Medical Birth Registry of Norway. A total of 1062 (1.3 per 1,000) infants died of SIDS; five deaths occurred as the second case in a family. The recurrence risk for the nextborn sibling was 5.6 per 1000, and for all subsequent siblings 4.8 per 1000, which would seem encouragingly low from a counseling point of view.

Family↗
PubMed1983

Prognosis in breast cancer patients with tumour cells in the efferent vessels of their axillary nodes.

The presence of tumour cells in the efferent vessels of the axillary nodes of breast cancer patients is termed efferent vascular invasion (EVI). The EVI status had been recorded in 112 cases which have now been followed for a mean of 120 +/- 8 months. At the start of the 10th year 17 per cent. of the EVI positives cases were alive, compared to 54 per cent. of the EVI negative. The EVI status has thus strong prognostic implications. It can be recorded in association with primary treatment on routine histological examination. No special equipment is required.

Axilla↗
PubMed1982

The risk of acetabular protrusion following prosthetic replacement of the femoral head.

A total of 24 patients treated with hemiarthroplasty showed a crude frequency of acetabular protrusion of 26 per cent. Two factors were associated with the development of protrusion: the length of the follow-up period and previous hip operation. The frequency of protrusion was estimated using logistic regression techniques based on information concerning the age of the patients, the length of the follow-up period and any previous hip operation. The frequency ranged from 4.8 per cent for a patient of 75 years or under, with a follow-up period of less than 12 months and no previous hip operation, to 61 per cent for patients of over 75 years, with a follow-up period exceeding 12 months, and a previous hip operation. Patients of over 75 years were 1.7 times more likely to develop protrusion than younger patients, patients previously operated on were 2.3 times more likely to develop protrusion than those not operated on previously, and patients with a follow-up time period exceeding 12 months were 7.9 times more likely to develop protrusion than patients with a shorter follow-up time.

Acetabulum↗
PubMedDate not supplied

Correlations of birth weight and gestational age across generations.

Maternal birth weight is known to be a predictor of offspring birth weight. Less is known about the recurrence of gestational age. In order to estimate the recurrence risk of low birth weight and preterm birth across generations in a population-based sample, 11,092 pairs of mother-firstborn offspring were obtained through an internal linkage in the Norwegian Birth Registry based on the years 1967-1969 (mothers) and 1986-1989 (offspring). A low correlation coefficient of 0.086 was found for gestational age across generations, whereas the correlation between maternal and offspring birth weight was 0.242. Mothers with birth weight below 2500 g had a significantly increased risk (odds ratio = 3.03, 95% conf. interval 1.79-5.11) of having a low birth weight child compared with mothers with birth weight above 4 kg. On the other hand, if the mother was born before the 37th completed week of gestation, the risk of having a preterm child was not significantly increased (odds ratio = 1.46, conf. interval 0.96-2.21) compared with mothers who were born at term. Thus, in contrast to birth weight, human variation in gestational age does not appear to be influenced by genetic factors to any large degree.

Adult↗
PubMedDate not supplied

Lymph node-negative breast cancer: the prognostic role and time dependency of age, tumor diameter and mean nuclear area.

This study of 786 node-negative breast cancer patients demonstrates that the prognostic effect of age at operation, tumor diameter and mean nuclear area (MNA) changed over time. Identifying patients at higher risk of dying after 5 years may be of clinical importance. These are patients who may have had a low metastatic tumor burden at the time of operation and in whom cytostatic adjuvant treatment could be of value. When estimating 10-year survival, a significant loss of strength was found for age. A near significant loss of effect was also found for MNA, while tumor diameter was the variable best maintaining prognostic power during the observation period. Due to the loss of strength for MNA and age when estimating 10-year survival, the observation period was divided into two periods. When estimating 5-year survival, MNA was the strongest variable, while tumor diameter and age gave additional significant information. When estimating the next 5 years, excluding patients who died before 5 years, only tumor diameter gave significant prognostic information (573 cases). This again stresses the importance of tumor diameter in assessing prognosis in node-negative patients.

Age Factors↗
PubMedDate not supplied

A prognostic index based on the mean nuclear area of breast cancer cells and efferent vascular invasion in the axillary nodes.

Statistical evaluation of the prognostic impact of different variants of the mean nuclear area (MNA) of tumour cells in breast carcinoma was used to find an optimal combination for use in conjunction with the absence/presence of tumour cells in the efferent vessels of the axillary nodes (EVI). This model gives an estimate of the relative prognostic impact of the different variables and their reliability. Combination of EVI with MNA of the primary tumour gave the optimal prediction of disease outcome; 81 per cent correct prediction before 60 months, falling to 73 per cent by 98 months after the operation.

Axilla↗
PubMedDate not supplied

Efferent vascular invasion and the mean nuclear area of axillary nodal tumour cells in breast cancer.

The presence of tumour cells of high mean nuclear area (MNA) in axillary nodal metastases from breast carcinoma is shown to be related to the finding of tumour cells in the efferent nodal vessels. In cases without efferent vascular invasion (EVI) the MNA was on average lower. EVI positivity combined with a high MNA is associated with a poor prognosis. However, a subgroup was identified, i.e. the MNA 1, with the smallest nuclei, in which prognosis approached that in the EVI negative. In the latter the differences related to MNA groups were not statistically significant.

Axilla↗
PubMedDate not supplied

Prognostic significance of p53 protein expression and DNA ploidy in surgically treated non-small cell lung carcinomas.

A series of 112 patients operated for non-small cell lung cancer was analyzed retrospectively. Nuclear suspensions were prepared from formalin-fixed, paraffin-embedded biopsies, and DNA content was measured simultaneously with p53 expression using flow cytometry. The expression of p53 protein was determined by the monoclonal antibody PAb 1801, which recognizes both wild-type (normal) and mutated forms of p53. By the level of p53 expression, four patient groups were statistically defined. Patients in the two groups with no detectable and extremely high p53 expression had a significantly better prognosis than patients in the two groups with moderately increased p53 expression. By logistic regression, p53 expression was found to be the single best predictor of 5 year survival. Patient age and tumor stage were less important prognostic factors. No difference in 5 year survival was observed between diploid and aneuploid tumors. We conclude that p53 is a useful prognostic predictor in low stage non-small cell lung carcinoma using the monoclonal antibody PAb 1801. The applicability of this antibody to archival material in flow cytometric analysis should allow a broad range of tumor types to be analyzed with respect to the prognostic significance of p53 overexpression.

Adult↗