Biomedical subjects

T Riise

Publications and source records attributed to T Riise.

At least 73 records · Page 4Linked to original sources

PubMed1995

Prognostic factors for survival in multiple sclerosis: a longitudinal, population based study in Møre and Romsdal, Norway.

A longitudinal, population based study of life expectancy in multiple sclerosis was performed in the county of Møre and Romsdal, Norway during the period 1950-84. A total of 251 patients with multiple sclerosis (110 men, 141 women, mean age at onset of disease 33.6 years) were included. The mean follow up time was 18.1 years. At the end of the study period 70 patients had died. Fifty four (77.1%) of these had multiple sclerosis as the underlying or contributing cause of death on the death certificates. Young age at onset, initial remitting clinical course, and the presence of sensory symptoms at onset were significantly associated with longer survival.

Adolescent↗

PubMed1994

Mortality among seamen with special reference to work on tankers.

BACKGROUND: Several studies demonstrate a high mortality among seamen but this has not been related to different types of work on board. This study examined a possible relationship between work on tankers and mortality. Tankers differ from other ships by carrying different types of oil, oil products and other chemicals. METHODS: Mortality was studied in 1687 men who were captains and mates during the period 1970-1987, and were registered by a Norwegian census in 1970. The data were linked to the Norwegian Register of Death Certificates. In all 181 deaths were found. Each case was age-matched at time of death to three individuals from the rest of the population alive at this date. Information about the seamen's work on different ships was obtained for cases and controls. The data were analysed using multivariate conditional logistic regression. RESULTS: Seamen working on tankers had a higher mortality rate ratio (RR = 2.43, 95% confidence interval [CI]: 1.65-3.60) than seamen who had not been working on tankers. The increased risk was especially related to death from cancer and from accidents, while no significantly increased mortality due to cardiovascular diseases was found. Employment as a mate on tankers showed the highest all-causes risk of death (RR = 3.14, 95% CI: 2.04-4.82) as well as for cancer (RR = 4.24, 95% CI: 2.02-8.88) and accidents (RR = 5.85, 95% CI: 1.66-20.60). Employment as a captain on tankers showed no significantly increased mortality. CONCLUSION: Exposure to chemicals on tankers may be related to the increased mortality, as this is the major difference between tankers and other ships and mates are exposed to chemical agents, while captains are not.

Accidents, Occupational↗

PubMed1993

Infections in childhood and adolescence in multiple sclerosis. A case-control study.

A case-control study on multiple sclerosis was conducted in Western Norway during the years 1986-1988. Included were 155 persons with multiple sclerosis and 200 controls, marginally matched according to age, sex and area of residence. The mean age at measles infection was for the cases 6.6 years and for the controls 5.7 years (p = 0.06). The cases had more frequently experienced bronchitis and/or pneumonia in the age group 11-15 years (OR = 3.20, 95% confidence interval 0.96-10.63). Tonsillectomies were reported more frequently by the cases. The odds ratio was especially high for those treated at age 0-6 years (OR = 3.44, 95% confidence interval 1.63-7.27). The results are consistent with the idea of MS as an age-dependent, host-immune response to infection during childhood or adolescence.

Adolescent↗

PubMed1992

Relationship between the degree of individual space-time clustering and age at onset of disease among multiple sclerosis patients.

A previous study of 381 multiple sclerosis (MS) patients from Norway has shown significant clustering of residence in adolescence among contemporaneous patients. Using a regression model with individual degree of clustering determined by Monte Carlo methods, this study utilizes the same data and shows a significant correlation (P = 0.002) between the degree of clustering and age at clinical onset of disease. A high degree of clustering in adolescence indicated a low age at clinical onset. This association was also verified independently of the regression model. The finding supports the theory of a common viral agent acting epidemically among nonpre-exposed individuals during adolescence, with MS developing in individuals with other necessary factors, such as a genetic predisposition.

Adolescent↗

PubMed1992

Early prognostic factors for disability in multiple sclerosis, a European multicenter study.

The effects of initial clinical variables on short-term prognosis are analyzed in a cross-sectional study of 574 multiple sclerosis patients from 7 centers in 5 European countries. Patients with a primary progressive course had a 2.3 higher mean disability score (EDSS) than the primary remittent group after a mean duration of disease of 6.6 years. High age at onset was associated with a primary progressive course, and was also related to increased risk of a rapid shift to a secondary progressive course. Among the remittent patients without a secondary progressive course a high age at onset was significantly correlated to a higher disability score. In the whole remittent group the presence of pyramidal and cerebellar symptoms at onset predicted both a high disability score and a rapid shift to a secondary progression, while the effect was reverse for sensory and visual symptoms. No difference between the sexes was found.

Adult↗

PubMed1992

Drinking habits and laboratory tests in seamen with and without chemical exposure.

The purpose of this study was to evaluate possible differences in drinking habits among seamen exposed to organic solvents and other hydrocarbon compounds compared to unexposed seamen. Information about alcohol consumption and alcohol-related problems was obtained by using an abbreviated version of the Michigan Alcoholism Screening Test, as well as additional questions about the quantity of alcohol consumption. Also, tests of serum gamma-glutamyl transferase and mean corpuscular volume were performed to reveal possible chronic toxic effects of chemical exposure and alcohol consumption, as physicians often use these blood tests in their health controls of seamen. The relationships between chemical exposure, age, smoking and alcohol consumption and results from blood tests were analyzed by using multiple regression analyses. Seamen exposed to organic solvents and other hydrocarbon compounds had more alcohol-related problems and more months of heavy drinking than did unexposed seamen. The previous year's alcohol consumption was similar in the two groups. A relationship between alcohol consumption and chemical exposure was not found. No correlation was found between chemical exposure and the results from the blood tests. Routine monitoring of gamma-glutamyl transferase and mean corpuscular volume did not seem useful in the evaluation of chemical hazards.

Adult↗

PubMed1992

Dietary omega-3 fatty acid supplementation and naproxen treatment in patients with rheumatoid arthritis.

In a controlled, double blind, clinical trial we tested the effect of dietary omega-3 fatty acid supplementation with and without naproxen and placebo, respectively, in 67 patients with active rheumatoid arthritis. The patients were randomized into 3 groups that received the following treatment: Group 1, corn oil ("placebo omega-3 fatty acids"), 7 g/day for 16 weeks, and naproxen, 750 mg/day for 10 weeks followed by a stepwise reduction to 0 mg/day during the following 3 weeks; Group 2, omega-3 fatty acids, 3.8 g of eicosapentaenoic acid plus 2.0 g of docosahexaenoic acid, and naproxen, 750 mg/day for 16 weeks; and Group 3, omega-3 fatty acids as Group 2 and naproxen as Group 1. At the end of the trial, patients in Group 2 had improved with respect to duration of morning stiffness and global assessment by physician and patient. In Groups 1 and 3 there was a significant deterioration for most of the variables measured. However, for duration of morning stiffness the deterioration was significantly less pronounced in Group 3 compared with Group 1. These effects might be ascribed to the dietary omega-3 fatty acid supplementation.

Adult↗

PubMed1992

Activation of blood platelets in workers exposed to organic solvents.

Organic solvents probably exert their clinical effects through distortion of cellular membrane structure and function. Blood platelets represent an easily available membrane system. This study describes an evaluation of mean platelet volume (MPV) and total platelet count (TPC) in a group of workers exposed to a mixture of organic solvents in paint factories. We have found a correlation between decreased MPV and present exposure. The reduction was reversed within an exposure-free interval of 3 weeks. The intracellular adenosine triphosphate/adenosine diphosphate (ATP/ADP) ratio was significantly increased in exposed workers, compatible with dense granule secretion. A quantitative study of the phosphoinositide cycle in the platelets revealed an increased concentration of the phosphatidic acid, indicating an increased turnover. These findings are consistent with a solvent-induced activation of circulating platelets.

Adenosine Diphosphate↗

PubMed1991

[Cancer among captains and mates on Norwegian tankers].

1,687 registered captains and mates from a Norwegian census in 1970 were monitored up to 1987. By matching the data from the census with data from the Norwegian Cancer Registry we discovered 104 cases of cancer. A control group of 376 was chosen among those without cancer. A nested case-control study design was used. The material was analysed using multivariate logistic regression. Increased risk of developing cancer was found in the group of seamen who had been working on tankers, especially among seamen who had been working as mate on these tankers. Exposure to chemicals is the major factor distinguishing tankers from other ships. Mates are exposed to chemicals while captains are not. The study indicates the presence of carcinogenic agents on these tankers.

Adult↗

PubMed1991

Clustering of residence of multiple sclerosis patients at age 13 to 20 years in Hordaland, Norway.

Geographic and temporal variation and migration studies point to an exogenous agent in the etiology of multiple sclerosis. If infectious etiology is involved, space-time clustering would also be expected. The authors analyzed 381 patients with a clinical onset of multiple sclerosis between 1953 and 1987 in the county of Hordaland, Norway. Patients within the same birth cohort had lived significantly closer to each other than would be expected during ages 13-20 years, with peak clustering at age 18 years (p = 0.002). Clustering was also shown between patients in pairs comprised of one individual with initial remittent disease and the other with chronic progressive course of disease, suggesting a similar etiology for both clinical patterns. Clustering between cases with widely divergent dates of clinical onset provides evidence of marked variation in latency. No similar clustering was observed in age-, sex-, and area-matched hospital controls without multiple sclerosis, and no clustering was found among the cases when using fixed number of years before onset. These results are compatible with a common infectious agent, such as the Epstein-Barr virus, acquired in adolescence in genetically vulnerable persons who are also not protected by an infection acquired before this age of susceptibility. Susceptibility could be related to the route of transmission or to other age-related covariates or it may be hormonally mediated.

Adolescent↗

PubMed1991

Electroencephalography, evoked potentials and MRI brain scans in saturation divers. An epidemiological study.

One hundred and fifty-six air and saturation divers, mean age 33.6 (range 21-49) years, were examined. The control group consisted of 100 offshore workers and policemen with the health requirements to have a diving certificate, mean age 34.0 (range 22-48) years. The examination protocol included electroencephalography (EEG), visual evoked potentials (VEPs), brain-stem auditory evoked potentials (BAEPs) and magnetic resonance imaging (MRI) of the brain and brain-stem. Abnormal EEGs, with focal slow waves mostly in the temporal regions and sharp potentials, were found in 18% of the divers and in 5% of the controls (P = 0.003). Abnormal EEGs correlated significantly with the exposure to saturation diving (P = 0.0006) and the prevalence of decompression sickness (P = 0.0102). Alcohol consumption was negatively correlated with abnormal EEGs (P = 0.0006). Mean I-III BAEP latency was increased (P = 0.047) in the diver group. P100 VEP latency decreased with age (21-49 years). High signal intensity changes obtained by MRI were found in 33% of the divers and in 43% of the controls (P = 0.14). It is concluded that the nervous system of saturation divers is influenced by their occupation and that EEG is a useful method in the health examination of divers.

Adult↗

PubMed1991

Neurological long term consequences of deep diving.

Forty commercial saturation divers, mean age 34.9 (range 24-49) years, were examined one to seven years after their last deep dive (190-500 metres of seawater). Four had by then lost their divers' licence because of neurological problems. Twenty seven (68%) had been selected by neurological examination and electroencephalography before the deep dives. The control group consisted of 100 men, mean age 34.0 (range 22-48) years. The divers reported significantly more symptoms from the nervous system. Concentration difficulties and paraesthesia in feet and hands were common. They had more abnormal neurological findings by neurological examination compatible with dysfunction in the lumbar spinal cord or roots. They also had a larger proportion of abnormal electroencephalograms than the controls. The neurological symptoms and findings were highly significantly correlated with exposure to deep diving (depth included), but even more significantly correlated to air and saturation diving and prevalence of decompression sickness. Visual evoked potentials, brainstem auditory evoked potentials, and magnetic resonance imaging of the brain did not show more abnormal findings in the divers. Four (10%) divers had had episodes of cerebral dysfunction during or after the dives; two had had seizures, one had had transitory cerebral ischaemia and one had had transitory global amnesia. It is concluded that deep diving may have a long term effect on the nervous system of the divers.

Adult↗

PubMed1991

Incidence of multiple sclerosis in Hordaland, western Norway: a fluctuating pattern.

The incidence of multiple sclerosis (MS) was studied in the county of Hordaland, western Norway. A significant increase in incidence in the period 1958-1987, a decline followed by a gradual increase in mean age at onset, geographic differences in time trends and a biphasic pattern revealed by a birth cohort analysis support the theory of real time-space fluctuations in the incidence of MS over time.

Adult↗

PubMed1991

Epidemiologic trends in multiple sclerosis in Møre and Romsdal, Norway: a prevalence/incidence study in a stable population.

The western part of Norway has been a low-to medium-frequency area for multiple sclerosis (MS). The prevalence of definite/probable MS on January 1, 1961, was 24.3/100,000 in the county of Møre and Romsdal, western Norway. Based on the same diagnostic criteria, the prevalence of definite/probable MS increased to 75.4/100,000 on January 1, 1985. The average annual incidence rate increased from 1.94/100,000 in the period 1950-1954 to 3.78/100,000 from 1975-1979. Remitting MS in the younger age groups of both sexes increased the most. We consider this increase of MS to be due to alteration in exogenous factors as variation in genetic susceptibility cannot account for the increase in the stable western Norwegian population. The rise in prevalence/incidence over the last 20 to 25 years in western Norway supports the theory that MS is a disease influenced by exogenous factors that show variation over time.

Adolescent↗

PubMed1990

Reduced performance in tests of memory and visual abstraction in seamen exposed to industrial solvents.

Eighty-five seamen exposed to a variety of organic solvents and hydrocarbon compounds during their work on chemical tankers were compared with 59 unexposed seamen. Visual memory, auditory memory and visual abstraction were examined 14 days or more after the last solvent exposure. Multivariate analyses were performed to control the effects of confounding factors such as age, alcohol consumption, smoking, cerebral concussions and educational level. Significant correlations were found between increasing solvent exposure and poor results in tests of auditory memory and visual abstraction. These results indicate adverse psychological effects caused by chronic organic solvent exposure.

Adult↗

PubMed1990

Cancer among captains and mates on Norwegian tankers.

A cohort of 1687 registered captains and mates from a Norwegian census in 1970 was followed until 1987 using a historical prospective design. By matching the data from the census to the Norwegian Cancer Registry, 104 cases of cancer were found. A control group of 376 was chosen among non-cases at baseline (1970). Information about the seamen's work on different ships was obtained from the National Register of Norwegian Seamen. The material was analysed using multivariate logistic regression. An increased risk of developing cancer was found in the group of seamen who had been working on tankers, especially oil tankers (OR = 6.47, 95%CI: 1.14, 7.24). The increased risk was found to be significantly correlated to working as mate on these tankers (OR = 6.95, 95%CI: 3.70, 13.04), whereas working as captain showed a much lower risk (OR = 1.42, 95%CI: 0.64, 3.15). Chemical exposure is the major factor separating tankers from other ships. Mates are exposed to chemicals while captains are not. The study indicates the presence of several carcinogenic agents on these tankers.

Adult↗

PubMed1990

Cerebrospinal fluid proteins and free amino acids in patients with solvent induced chronic toxic encephalopathy and healthy controls.

The concentrations of protein, albumin, IgG, and free amino acids in the cerebrospinal fluid of 16 patients with chronic toxic encephalopathy due to organic solvents were measured. The patient group consisted of all patients with this diagnosis in a neurological department in 1985. The diagnosis was based on neuraesthenic symptoms, pathological psychometric performance, and verified exposure to neurotoxic organic solvents. A control group of 16 patients with myalgias or backache, or both, and no signs of disease was used for comparison. The purpose was to study possible changes in the cerebrospinal fluid that might contribute to understanding the aetiology of solvent induced chronic toxic encephalopathy. A rise in protein, albumin, and IgG was found in the patient group compared with the control group, as well as reduced concentrations of phosphoethanolamine, taurine, homocarnosine, ethanolamine, alpha-aminobutyric acid, and leucine. Using a stepwise multiple regression analysis, taurine was negatively correlated to exposure to solvents. These findings may indicate membrane alterations in the central nervous system related to exposure to organic solvents.

Aged↗

PubMed1990

A nested case-control study of disability pension among seamen, with special reference to neuropsychiatric disorders and exposure to solvents.

A cohort of 1,687 captains and mates from different types of ships were followed for recording of disability pension from 1970 to 1986. 199 cases were found. At date of diagnosis each case was age-matched to 4 randomly selected seamen within the rest of the cohort at risk. A strong relationship between disability pension due to neuropsychiatric diagnoses and work on tankers was found, especially when restricted to work as a mate on the tankers. These mates experience the highest exposure to organic solvents within the investigated group. The findings indicate an occurrence of chronic nervous system disorders due to long-term exposure to organic solvents.

Case-Control Studies↗