Day sleep (after night work) and night sleep (after day work) were studied in two groups of locomotive engineers aged 25-35 and 50-60 a, respectively. All recordings were made in the homes of the subjects. For both groups day sleep was reduced by approximately 3.3 h, mainly affecting rapid eye movement sleep and stage 2 sleep. Diuresis and the excretion of noradrenaline were increased during day sleep. The ratings of sleepiness were higher after night work than after day work. Several indices of disturbed daytime sleep correlated significantly with catecholamine excretion. The age groups differed mainly in that the older subjects had relatively more stage shifts, awakenings, stage 1 sleep, a higher diuresis, and a higher noradrenaline excretion during day sleep. It was concluded that night work is detrimental to sleep and that negative effects are exacerbated by increasing age.
Neuroblastoma has several characteristics that suggest that preclinical diagnosis might improve outcome. Therefore, the Quebec Neuroblastoma Screening Project was undertaken from 1989 to 1994 to examine infants at 3 weeks and 6 months by measuring urinary catecholamine metabolites.
Over the 5-yr period, 45 tumors were detected by screening, 20 were identified clinically prior to the third week, and 64 were identified clinically at a later time. We analyzed available tumors for Shimada histopathology, tumor ploidy, MYCN copy number and serum ferritin.
Of the tumors detected by screening, only 2 of 45 tested had unfavorable histology, 2 of 45 had diploid or tetraploid DNA content, 0 of 43 had MYCN amplification, and 4 of 44 had elevated serum ferritin. All of these patients are alive and well. The 20 patients detected prior to the 3-week screen had similar biological characteristics. In contrast, of the patients detected clinically after 3 weeks of age, 19 of 51 testedhad unfavorable histology, 25 of 66 had diploid or tetraploid tumors, 12 of 56 had MYCN amplification, and 14 of 54 had elevated ferritin.
The difference between the screened and clinically detected cases was highly significant for each biological variable. Preliminary data on other biological variables, such as neurotrophin expression and allelic loss on 1 p in these patients are consistent with the above findings. These data suggest that mass screening for neuroblastoma at or before 6 months of age detects almost exclusively tumors that have favorable biological characteristics, many of which might have regressed spontaneously. Thus, continued mass screening for neuroblastoma at 6 months is unlikely to accomplish its intended goal, and should probably be discontinued.
The diagnosis of pheochromocytomas requires consideration among patients suffering from hypertension, unexplained spells, incidental adrenal masses, or a family history of pheochromocytoma. Accordingly, the diagnosis requires a biochemical test with high sensitivity and specificity.
To compare plasma free metanephrines as measured by a commercial immunoassay and the 24-hour urinary excretion of catecholamines.
Plasma free metanephrines were measured in 185 patients suspected of pheochromocytoma. Concomitant measurements of urinary catecholamines were performed in 115 patients. Based on clinical findings, imaging and biochemistry 11 cases were found; 9 were diagnosed with pheochromocytoma, one patient with paraganglioma and one patient with ganglioneuroma.
All patients with pheochromocytoma/paraganglioma had abnormally elevated concentrations of either plasma metanephrine or normetanephrine. The patient with ganglioneuroma had normal plasma metanephrine levels, corresponding to a sensitivity of 91%. In two patients where pheochromocytoma was excluded, plasma metanephrin or normetanephrine was above the reference level, corresponding to a specificity of 99%. Urinary catecholamines were determined in 10 of 11 patients with a positive diagnosis, and all 10 showed elevated levels of either urinary epinephrine or norepinephrine, including the patient with ganglioneuroma (equivalent to a sensitivity of 100%). Seven patients, in whom pheochromocytoma was excluded, had elevated urinary catecholamines (equivalent to a specificity of 94%).
Measurement of plasma free metanephrines by immunoassay appears to be a useful diagnostic test in patients suspected of pheochromocytoma, with a high specificity as compared with urinary catecholamines. The latter may result in fewer false-positive findings, an outcome which may be particularly troublesome.
The effect of the obstructive sleep apnea syndrome on energy expenditure is controversial. The objective of this study was to assess the relationship between 24-hr energy expenditure or sleeping metabolic rate and features of the obstructive sleep apnea.
Twenty-four apneic men took part in this cross-sectional study and were classified in quartiles of nocturnal desaturation severity, i.e. of percentage total sleep time with SaO2
Hypothermia and hyperthermia related cases recorded for the period 1973 to 1984 were collected from the files of the Department of Forensic Medicine, University of Oulu, and the necropsy protocols including toxicological results were analyzed. The fact that similar alcohol concentrations were found in both types of fatalities points to the poikilothermic effect of alcohol in humans, as found in animal studies. Both types of deaths seem to be associated with the alcohol elimination phase. Antidepressants and neuroleptics were most often found in the hypothermia cases, but benzodiazepines were also quite frequently present. In spite of the diminished use of barbiturates, these still appear in hypothermia fatalities. Certain other drugs that affect thermoregulation were also noted in solitary cases. Extended toxicological analysis was seldom made in the cases of hyperthermia deaths, and no firm conclusions on the poikilothermic effect of psychotropic drugs could be reached, for example. Therapeutic drug concentrations did not alone predispose the subjects to hypothermia, but appeared in connection with alcohol consumption or chronic diseases.