Fatal diving accidents in western Norway 1983-2007.

Despite efforts to reduce their number, fatal diving accidents still occur. The circumstances and post-mortem findings in 40 fatal diving accidents in western Norway from 1983 through 2007 were investigated. Diving experience, medical history and toxicology reports were retrieved. The material consisted of recreational divers, professional saturation divers and professional divers without experience with saturation. In 33 cases the diving equipment was examined as part of the forensic investigation. In 27 cases defects in the diving equipment were found. For six divers such defects were responsible for the fatal accidents. Eighteen divers died on the surface or less than 10 m below surface. Five divers reached below 100 msw, and two of them died at this depth. The fatalities were not season-dependent. However, wave-height and strength of currents were influential factors in some cases. Twelve divers were diving alone. Twenty divers had one buddy, 9 of these divers were alone at the time of death. The cause of death was drowning in 31 out of 40 divers; one of them had a high blood-ethanol concentration, in two other divers ethanol was found in the urine, indicating previous ethanol consumption. Nine divers died from sudden decompression, pulmonary barotraumas, underwater trauma and natural causes. The study shows that most of the fatal diving accidents could be avoided if adequate diving safety procedures had been followed.

Posterior uveal melanoma treated with I-125 brachytherapy or primary enucleation.

PURPOSE: To study the incidence, clinical findings, and tumour characteristics of posterior uveal melanoma in Western Norway, and to report the results of a consistent treatment strategy (I-125 brachytherapy or primary enucleation) over a 13-year period. METHODS: The clinical records of all patients with posterior uveal melanoma referred between January 1993 and December 2005 were reviewed. Clinical data, radiation parameters, visual outcome, and mortality were analysed in a dedicated database. RESULTS: The study included 111 consecutive patients. The annual age-adjusted incidence (per million population) of posterior uveal melanoma was 8.5 for women and 8.9 for men. Fifty-six patients underwent I-125 brachytherapy, 52 were enucleated, and three received no treatment. The median follow-up time was 36 months (mean, 52 months; range, 2 months to 13 years). In the brachytherapy group, two eyes were enucleated owing to tumour recurrence and two because of neovascular glaucoma. A visual acuity of 0.1 or better, present in 87% of the patients before brachytherapy, was retained in 40% after a median follow-up of 61 months. After brachytherapy, the 5- and 10-year melanoma-specific mortality rates were 13.4 and 23.8%, respectively. The corresponding mortality rates for patients treated with primary enucleation were 49.5 and 49.5%. CONCLUSION: After brachytherapy, many patients lost useful vision due to radiation-induced complications. The probability of retaining the eye was high and only two patients experienced recurrent tumour growth. The mortality rates compare well with published series, and the differences in tumour size explain the difference in mortality between the two treatment groups.

Grey matter pathology in multiple sclerosis.

Although multiple sclerosis (MS) has been considered a white matter disease, MS lesions are known to occur in grey matter. Recent immunohistochemical studies have demonstrated extensive grey matter demyelination in chronic MS. The most common lesion type consists of purely cortical lesions extending inward from the surface of the brain, this lesion subgroup is grossly underestimated by standard histochemical myelin staining methods. Some MS patients have subpial demyelination in all cortical areas of the brain; this pattern has been termed ''general cortical subpial demyelination''. Extensive cortical demyelination is associated with the progressive phases of disease, as less cortical demyelination has been detected in relapsing-remitting MS. The pathology of grey matter lesions differs from that of white matter lesions; grey matter lesions are less inflammatory, with less macrophage and lymphocyte infiltration. In purely cortical lesions there is no significant increase in lymphocytes compared with non-demyelinated adjacent cortical areas in MS patients or cerebral cortex in control patients. Significant axonal transection and neuronal loss have been demonstrated in grey matter MS lesions. Current magnetic resonance imaging (MRI) methods are not sensitive for purely cortical MS lesions. The clinical significance of cortical MS lesions may not be characterised until more sensitive MRI methods are developed.

Intracortical multiple sclerosis lesions are not associated with increased lymphocyte infiltration.

The present study examined the extent and distribution of lymphocyte infiltration in demyelinated lesions in the cerebral cortex of multiple sclerosis (MS) patients. Tissue sections from the brain of 10 MS patients and five patients without neurological disease were double labeled for myelin basic protein and the lymphocyte markers CD3, CD4, CD8, CD45RO, and CD20. The highest density of CD3-positive T cells was found in MS white matter lesions (40.4/10 high power fields (hpf)). Fewer T cells were detected in cortical lesions that extended through both white and gray matter (12.1/10 hpf; P < 0.001). The lowest number of T cells was detected in intracortical demyelinated lesions (1.1/10 hpf). This was equal to the lymphocyte density in nondemyelinated cerebral cortex within the same tissue block (1.1/10 hpf) or cerebral cortex in control brains (1.8/10 hpf). A similar distribution was found using the CD4, CD8, and CD45RO markers. CD20-positive B cells were scarce in all specimens examined. These data indicate that areas of intracortical demyelination in chronic MS are not associated with an increased number of lymphocytes, or an altered distribution of lymphocyte subsets, when compared with control areas in MS and control patients. This finding indicates that the extent of lymphocyte infiltration in MS lesions is dependent on lesion location.

Invasiveness in vitro and biological markers in human primary glioblastomas.

Invasion of spheroids from 20 human primary glioblastomas into precultured fetal rat brain tissue in culture has been studied and quantified. Between 30 and 98 percent of the normal brain tissue was destroyed by invading glioma cells within 4 days. The degree of invasion did not correlate with patient survival. A slightly higher invasiveness and shorter survival was seen in tumors with EGF receptor overexpression, and the opposite pattern was found for tumors with a TP53 mutation. The degree of invasiveness in vitro was far higher than would be expected from the dynamics of clinically observed tumor spread. This suggests that mechanisms suppressing invasion may be operative in the normal brain; alternatively the differences may be due to a higher permissiveness of the fetal brain tissue for invasion in vitro.

A histopathologic and immunocytochemical study of the spinal cord in amateur and professional divers.

To clarify the influence of diving activity on the central nervous system, we studied 10 amateur and 10 professional deceased divers with emphasis on the presence of subacute or chronic pathologic changes in the spinal cord. Of the 10 professional divers (median age 38 yr; range 29-52; median experience in excess of 13 yr), 7 were experienced saturation divers. Five had dived to a maximum depth of 150 meters of seawater, the 2 others to 300 and 500 msw, respectively. Five of the professional divers had experienced decompression sickness. The experience of the amateur divers (median age 29 yr; range 17-51) varied from a few dives to many years of recreational diving. The spinal cords were formalin-fixated and routinely processed for neuropathologic examination, which included light microscopy after immunostaining for glial fibrillary acidic protein and monocyte-macrophage-microglial markers. The microscopic examination did not reveal previous spinal cord damage. Thus, diving activity, saturation diving to extreme depths included, does not in itself seem to lead to necrosis, degeneration, or scar formation in the human spinal cord.

Leptomeningeal tissue: a barrier against brain tumor cell invasion.

BACKGROUND: Primary brain tumors are characterized by an extensive infiltrative growth into the surrounding brain tissue. This process is confined to the central nervous system, and tumor cell metastasis to other organs is rare. However, other tumors of non-neural origin may frequently metastasize to the central nervous system. PURPOSE: The purpose of the present study was to examine the invasive behavior of different glioma cells into tissues of neural (brain aggregates) as well as non-neural origin (leptomeningeal tissue). Using the same target tissues, the invasive characteristics of two neural metastatic tumors (one malignant melanoma and one small-cell lung carcinoma) were also studied. This direct comparison of the invasive behavior between tumors of neural and non-neural origin provides valuable information regarding the mechanisms of glioma cell dissemination in the central nervous system. METHODS: The in vitro invasive behavior of human tumors of the central nervous system into human leptomeningeal tissue as well as into normal rat brain tissue was studied. For this purpose, a co-culture system consisting of tumor biopsy specimens, human leptomeningeal cell aggregates, and brain cell aggregates was established. Three glioblastomas, one oligodendroglioma, one meningioma, one small-cell lung carcinoma, and one malignant melanoma were studied. RESULTS: In co-cultures of gliomas and leptomeningeal cell aggregates, a well-defined border between the two tissues was observed. The brain cell aggregates, in contrast, were consistently invaded by the glioma cells. The brain metastases showed a different invasion pattern. The metastatic cells invaded and progressively destroyed leptomeningeal cell aggregates, whereas they did not invade the brain cell aggregates. Upon confrontation of the leptomeningeal tissue with the meningioma, a fusion of the two tissues was observed. Immunostaining of the leptomeningeal tissue showed a strong expression of the basement membrane components fibronectin, collagen type IV, and laminin with no expression of glial fibrillary acidic protein, neuron-specific enolase, or S-100 protein. CONCLUSIONS: The present study indicates that there may be important biologic differences between the invasive behavior of gliomas and non-neuroepithelial tumors. Our co-culture experiments suggest that leptomeningeal cells and associated acellular components may constitute a barrier against glioma cell invasion. However, this barrier may not be functional for metastatic tumors to the brain. The presence of glioma cells within the leptomeninges should not necessarily be taken as evidence of aggressive growth or as an indicator of malignancy.

A neuropathologic study of the ependymoventricular surface in diver brains.

Interference with the dynamics of cerebrospinal fluid may lead to loss of ependymal lining in the ventricles of the brain. The ependymal loss of the lateral ventricles under the corpus callosum at the level of the commisura anterior was measured in 21 diver brains and in a control material of 15 neurologic and non-neurologic brains. The divers were sport divers and professional divers with and without saturation exposure. The different groups were compared with respect to the mean loss of ependymal cells (in percentage). A statistically significant higher loss of ependyma was found in the total number of divers than in the controls. There was no significant difference between the group of sport divers and the control group. The largest loss of ependymal cells was found in the professional divers without saturation experience. Statistically, this loss was significantly larger than the loss of ependymal cells in the controls.

Tumour volume reduction following gamma knife radiosurgery: the relationship between X-ray and histological findings.

The case histories of two young ladies with Cushing's disease are described. Both patients were treated first with Gamma Knife radiosurgery and subsequently by microsurgery. The radiosurgery caused a marked reduction in tumour volume but only a partial relief of the endocrinopathy. Comparison of the histological findings with the radiological findings following radiosurgery indicates that confluent necrosis is not a prerequisite for a reduction in tumour volume. It seems more likely that the reduction in tumour volume is related to changes in cellular dynamics.

An immunohistochemical study of mononuclear cells in meningiomas.

A consecutive series of 34 meningiomas were re-examined as to subtype and presence of nuclear atypia, mitotic figures, areas of high cellularity and necrosis. Meningioma cells were epithelial membrane antigen (EMA) positive in 31 out of the 34 tumours. The presence of mononuclear cells and macrophages was assessed by immunohistochemistry using the monoclonal antibodies L26 (CD20, B cell marker), DF-T1 (CD43, T cell marker), KP1 (CD68, macrophage marker) and MAC387 (monocytes). L26 positive B cells were observed infrequently. CD43 positive mononuclear cells were infiltrating the parenchyma as individual cells and as groups of cells in 29 (87% of the tumours). CD68 positive macrophages were seen in 19 (59% of the tumours), as scattered single cells or groups of cells. There was a statistically significant association between the number of CD68 positive cells (necrotic areas excluded) and microscopic features of aggressiveness, i.e. high cellularity as well as the combination of nuclear atypia and frequent mitotic figures. MAC387 stained only a few cells; the immunopositive cells were present mainly within and around vessels. Meningioma cells displayed a diffuse immunopositivity for L26 (CD20) in 29 out of 34 meningiomas, but did not stain with macrophage markers. Mast cells were found in 9 out of 32 tumours; when present they were significantly more prevalent in the syncytial subtype. Thus, mononuclear cell infiltrates in meningiomas are mainly composed of T cells and macrophages, indicating an immune system surveillance and response to the tumour cells. The functional and prognostic significance of the presence of CD68 positive cells, macrophages, deserve further study in the search for more reliable histological criteria to predict recurrence and biological aggressiveness in meningiomas.

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. 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.

Neoplasms of the central nervous system in Norway. IV. A population-based epidemiological study of meningiomas.

All 1632 cases of meningioma reported to the Norwegian Cancer Registry from 1955 to 1986 have been studied: a) 96% appeared in patients over 30 years of age, b) 95% were histologically benign, c) 88% were located intracranially, and d) 66% occurred in females. The female predominance manifested itself in the middle age period. Eighty-seven percent of the intraspinal meningiomas presented in females, but the ratio between intracranial and intraspinal meningiomas was significantly lower in females (5.4) than in males (20.4). Increased incidence rates of meningioma in females are revealed for the birth-cohorts after 1930. The reason for this change is unclear so both environmental and hormonal factors should be explored. Based upon the epidemiological data, it appears that female sex hormone(s) could act as a growth stimulus in the development of meningiomas, but are neither sufficient nor necessary for tumourigenesis.

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.

Giant cell glioblastoma: a work-up of 2 cases with long survival.

Two patients, in whom visual disturbance (Case 1) and sudden hemiparalysis due to a hemorrhagic lesion (Case 2) had led to craniotomy and histological diagnosis of giant cell glioblastoma, each had an unexpectedly long survival period of 7 and 9 years, respectively. Radiologically, the tumours were well demarcated, but without any distinguishing features, by comparison with glioblastomas in general. The tumours, to a great extent, consisted of cells with large, bizarre multiple nuclei. The highly pleomorphic cells displayed strong cytoplasmic GFAP immunopositivity, which suggested an astroglial origin. Thus, these tumours were considered a variant of glioblastoma ("giant cell glioblastoma") with a more favourable prognosis than experienced by most patients with glioblastoma.

Glioblastoma associated with multiple sclerosis: coincidence or induction?

A 63-year-old man died of a brain tumor 29 years after onset of multiple sclerosis (MS). The MS diagnosis was based upon clinical evidence of two brain stem lesions, separate in time, retinal periphlebitis, a fluctuating course of the disease, and supported by the observation of definite cognitive impairment at the age of 41 years, and an increased number of lymphocytes in the cerebrospinal fluid which normalized during gradual recovery. The MS diagnosis was confirmed at autopsy, which also revealed a glioblastoma developing adjacent to typical MS plaques.

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.

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.

Trans fatty acids. 1. Growth, fertility, organ weights and nerve histology and conduction velocity in sows and offspring.

Effects of dietary trans fatty acids on the pre- and postnatal growth and development in pigs were studied with special emphasis on nervous tissue. In experiment 1, female pigs were fed partially hydrogenated fish oil (PHFO) (28% trans) or soybean oil (PHSBO) (36% trans), in comparison with lard (0% trans) from weaning (3 wk) through the first reproduction cycle (up to 2 yr). In experiment 2, female pigs were fed two fish oils (33 and 19% trans) in comparison with coconut oil (0% trans) in diets with low and high levels of linoleic acid (18:2n-6 cis, cis) from gestation until their offspring were three wk old. Compared with the trans-free fats, the trans-containing fats had no effect on growth and development, feed consumption and utilization or on the weight of the brain, heart, kidneys, liver, lungs or spleen in the adult sows and their offspring. No effects from the experimental fats were found on histology and conduction velocity of the peroneal nerve. An increased number of the sows fed PHFO had fertility problems compared with those fed lard and PHSBO in Expt. 1, but no similar effects were seen in Expt. 2. It is concluded that consumption of trans fatty acids with 18-22 carbon atoms from PHFO and with 18 carbon atoms from PHSBO at levels that were 5 to 12 times higher than those normally consumed by humans had no detrimental effects on female pigs or their offspring during pregnancy and lactation.