Biomedical subjects
A Helseth
Publications and source records attributed to A Helseth.
Primary intraspinal neoplasms in Norway, 1955 to 1986. A population-based survey of 467 patients.
A survey of all patients (173 males and 294 females) registered with primary intraspinal neoplasms in the Norwegian Cancer Registry from 1955 through 1986 is presented. Annual age-adjusted incidence rates of new tumors per one million population were three for males and five for females. Altogether, 89% of the tumors were verified histologically. Meningioma was the most common tumor type, followed by ependymoma and neurilemoma. Intraspinal ependymomas accounted for 34.5% of all 223 ependymomas of the central nervous system, whereas only 0.2% of the 3046 glioblastomas were found intraspinally. Patients with intraspinal meningioma had a better life expectancy than those with intracranial meningioma. The 5-year relative survival rate for patients with intraspinal ependymoma was 88.9% in contrast to 24.4% for patients with intracranial ependymoma.
Neoplasms of the central nervous system in Norway. III. Epidemiological characteristics of intracranial gliomas according to histology.
Data were analysed from 4859 patients with different histological types of intracranial glioma registered by the Norwegian Cancer Registry between 1955 and 1984. Glioblastoma comprised 57.9% of all cases. The second most common primary brain tumour was astrocytoma (19.0%), then mixed glioma (9.2%), oligodendroglioma (7.9%), medulloblastoma (3.1%) and ependymoma (2.9%). A primary brain tumour in a child is approximately twice as likely to be an astrocytoma as a medulloblastoma. The age-specific incidence for glioblastoma increases with age, whereas the incidence of astrocytoma and oligodendroglioma peaks at middle age. Both glioblastoma and astrocytoma showed increased incidence rates over the study period and this was most pronounced in the age-group above 60 years. The prognosis for gliomas varied with age at time of diagnosis, generally being better the younger the patient. For oligodendroglioma patients, survival prospects were independent of age at time of diagnosis. The best prognosis was seen in patients up to 30 years with astrocytoma. Applied in epidemiology, the data indicate that astrocytoma, oligodendroglioma, mixed glioma and ependymoma may be treated as a group which should be separated from both glioblastoma and medulloblastoma.
Neoplasms of the central nervous system in Norway. V. Meningioma and cancer of other sites. An analysis of the occurrence of multiple primary neoplasms in meningioma patients in Norway from 1955 through 1986.
The association between meningioma and a primary malignant neoplasm at another site was studied. The data from the population-based Norwegian Cancer Registry were analysed according to whether the meningioma occurred before or after the malignant neoplasm. Male patients with meningioma showed a raised risk for developing a subsequent renal cancer. A significant association was found between meningioma and subsequent breast cancer in females 50-64 years old at time of meningioma diagnosis and between breast cancer and subsequent occurrence of meningioma. Breast cancer patients with symptoms of an intracranial neoplasm may therefore have a potentially curable meningioma and female meningioma patients over 50 years should be considered for breast cancer screening programmes.
[Interpretation of terms indicating uncertainty in pathologic diagnoses].
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[Cholesterol embolization. A serious complication to angiography].
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Toxicity of n-C9 to n-C13 alkanes in the rat on short term inhalation.
Male Sprague Dawley rats were exposed to inhalation of n-C9 to n-C13 alkanes close to air saturation at 20 degrees (4438, 1369, 442, 142 and 41 p.p.m., respectively) for 8 hours and observed for the following 14 days. In addition, exposure to higher and lower concentrations of n-C9 was performed. The concentration of alkane in the brain after exposure exceeded that of blood for the lower alkanes, while the higher alkanes possessed a brain/blood ratio equal to or less than unity. Gross ataxia, general and focal seizure and spasms were observed in animals exposed to n-C9 in the range from 5280 to 3560 p.p.m. No toxic effects were observed in animals exposed to 2414 p.p.m. of n-C9 or to the other alkanes. An LC50 value for n-C9 of 4467 +/- 189 p.p.m. was estimated. Despite the clinical improvement in animals surviving the n-C9 exposure of 4438 p.p.m. (6/10), severe cerebellar damages were found at autopsy at the end of the observation period, with a loss of Purkinje cells as the most prominent feature. Immediate post mortem examination (4/10) showed marked vascular congestion of the liver as well as slight fatty degeneration but no cerebellar damage. No abnormalities were observed in animals exposed to the other alkanes. The significant distribution in the brain of the n-C9 alkane, the clinical signs of cerebellar dysfunction and the damage of cerebellar neurons would suggest CNS to be a possible target organ for the toxic effects of the n-C9 alkane.
Neoplasms of the central nervous system in Norway. I. Quality control of the registration in the Norwegian Cancer Registry.
The Norwegian Cancer registry includes reports on 8,933 cases of primary central nervous system neoplasms diagnosed in the period 1955-1984. Before submitting this data set to epidemiological analysis, errors were searched out and subsequently corrected, and a quality control was performed. First, seven categories of neoplasm records likely to be faulty were defined. In this way 109 cases (1.2% of the total) were identified for extensive study. Minor or major errors were found and corrected in 86 cases. The main source of error was misinterpretation of data by cancer registry staff (67 out of 109 cases). The second approach was to evaluate the quality of the corrected data set by a random draw of 300 cases. Errors concerning total incidence rates and rates for main groups of gliomas, meningiomas and neurilemmomas represented 0.3% of the total, and altogether 9.3% of errors of varying severity were revealed. The series is discussed with regard to prerequisites for serving as reliable data on CNS neoplasm epidemiology. The results indicate that the data from the Norwegian Cancer Registry is sufficiently valid for a thorough study of CNS neoplasms.
Neoplasms of the central nervous system in Norway. II. Descriptive epidemiology of intracranial neoplasms 1955-1984.
A population-based study of 8480 patients - 4508 (53%) males and 3972 females - with primary intracranial neoplasms reported to the Norwegian Cancer Registry during the period 1955-84, is presented. 81% of the cases were histologically verified. The peak age-specific incidence rate in the total series occurred in the age-group 55-64 years. Gliomas constituted the largest histological group with an age-adjusted incidence rate of 5.0 cases per 100,000 population per year for males and 3.5 for females. Case ascertainment of primary intracranial neoplasms is reduced above the age of 60 in Norway, mostly due to a a low autopsy rate. The major impact of the introduction of computer tomography (CT) in the case ascertainment of intracranial neoplasms has been a raised incidence, in patients over the age of 60, of neoplasms which are not histologically verified.
[Clear-cell sarcoma of the tendons and aponeurons].
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[Thyroid carcinoma. A retrospective analysis of 10-year surgical case material].
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Alcohol abstainers: a low-risk group for cancer--a cohort study of Norwegian teetotalers.
Groups with assumed health-protective life-styles have been studied for several decades, in search of causes for cancer. We have analyzed cancer incidence, total mortality, and cause-specific mortality in Norwegian teetotalers to assess the possible health gains from an alcohol-abstaining life-style. A cohort of 5332 members of the International Organization of Good Templars was followed for 10 years from 1980. The cancer incidence and the cause-specific mortality of the cohort has been compared to that of the total Norwegian population. The standardized incidence ratio (SIR) for all cancer sites was 74 [95% confidence interval (CI), 64-80] for men and 72 (95% CI, 61-84) for women. For possible alcohol-associated cancers, such as cancer of the oral cavity, pharynx, esophagus, liver, and larynx, the SIR was 43 (95% CI, 17-88) for both sexes combined. For lung cancer the SIR was 57 (95% CI, 37-90) for men and 10 (95% CI, 0-57) for women. When all alcohol- and tobacco-associated cancers were excluded, the SIR for both sexes combined was 79 (95% CI, 69-87). The standardized mortality ratio for total mortality was 81 (95% CI, 65-74). This significant decrease in total mortality was caused by reduced risks for all major causes of death. The study indicates that members of the Norwegian chapter of the International Organization of Good Templars are a low-risk group not only regarding alcohol- and tobacco-associated cancers, but also regarding all other cancers.