Electroencephalographic sleep of younger depressives. Comparison with normals.

The electroencephalographic sleep of younger depressives (aged 20 to 44 years) was compared with that of an age-matched group of normals. The patients demonstrated many of the typical sleep changes reported for older depressed populations: shortened rapid-eye-movement (REM) latency; REM sleep activity alterations, with a shift to the early portion of the night (first REM period); reduced delta sleep; and sleep efficiency reductions marked by sleep-onset difficulties. The traditional scoring procedures were supplemented by automated REM and delta-sleep analyses that provided more precise delineation of these differences between patients and normals, particularly the distributions of REM activity and delta-wave patterning.

Concordance between habitual sleep times and laboratory recording schedules.

The validity of laboratory-based studies of sleep depends, in part, upon good concordance between habitual sleep schedule and laboratory recording schedule. Without good concordance, error variance due to the circadian misplacement of sleep and to different amounts of time in bed is probable. In an assessment of scheduling concordance in 1,762 research patient nights over two time intervals, we observed good concordance (< 30-minute discrepancy) in 71.2-77.3% of bedtimes and waketimes, discrepancy (difference of > or = 30 minutes) in 14.9-24.2% of bedtimes and waketimes, and missing data in 4.6-7.5% of times. Waketime differences were consistently in the direction of earlier laboratory than habitual waketimes, whereas differences in bedtime were about equally divided between earlier and later (laboratory vs. habitual). Subjects with schedule discordance averaged 19.5 minutes less time in bed during laboratory sessions as compared with their habitual sleep schedule, whereas subjects with schedule concordance averaged only 3.6 minutes less (p < 0.001). Our experience suggests that it may be more difficult to achieve higher rates of concordance among young adult and middle-aged subjects than among elders and that patient requests related to external constraints on scheduling were a frequent reason for discrepancy. We strongly recommend a policy of routinely including data on laboratory versus habitual sleep times in peer-reviewed publications.

A computer algorithm to determine the nadir and rise time in nocturnal cortisol secretion.

The nadir concentration value and the time of the circadian rise are two important characteristics of the nocturnal cortisol secretory pattern. A computer algorithm has been developed which objectively determines these parameters, supplementing the subjective evaluating methods previously used. The algorithm smooths the cortisol values and incorporates the intra-assay variability when calculating the nadir and rise. It was tested on 156 nights of cortisol data for healthy control and depressed subjects. The algorithm results closely matched the nadir and rise time subjectively determined by the investigators. With careful screening of the computer generated results, the algorithm decreases the reliance on subjective methods to determine the actual nocturnal cortisol nadir and rise time.

Quantitative determination of antigens in biological fluids by the antibody radial immunodiffusion method. Antigens in agar gel.

An antibody diffusion method is described for quantitative determination of antigens in biological fluids. It is a multiple radial immunodiffusion (MRD) method. The fluid is mixed with agar gel during the test and poured on to a plate of standard size and antisera are placed in circular reservoirs. On the same plate as many proteins can be determined as there are monospecific antisera available. The calibration curve is made by means of standard antigen solutions (normal human sera). There is no need to concentrate even biological fluids of low protein concentration (cerebrospinal fluid, urine etc.). The implementation of the process for various body fluids, as well as the advantages and disadvantages of the method are described.

Conditions for albumin dimerisation in hephrotic urines. Dependence on an ultrafilterable factor.

At--14 degrees C the albumin in the urine of some patients with a nephrotic syndrome polymerises into dimer and higher polymers. This occurs at low ionic strengths within 1-3 days and in the pH range 5-10. For polymerisation both an altered albumin molecule and a low molecular weight ultrafilterable fraction in the urine are necessary. The appearance of both is probably related to steroid therapy. The ultrafiltrate fraction has molecular mass < 700, and is not peptide, amino acid, fatty acid or highly charged ion.

Application of automated REM and slow wave sleep analysis: I. Normal and depressed subjects.

Computerized analysis of rapid eye movement (REM) and delta electroencephalographic (EEG) sleep patterns in normal and depressed subjects offers opportunities to examine sleep more precisely than previously possible. In the present study, automated REM analyses demonstrated good reliability with traditional manual procedures in both normal and depressed subjects. However, automated delta analyses correlated well with traditional scoring in normal subjects, but not in depressed patients. These findings suggest the use of automated delta techniques similar to those employed in this report or spectral analytic techniques in the following types of studies: specificity of delta sleep in various psychiatric syndromes, changes in delta sleep produced by the administration of psychotropic agents, relationships between delta sleep and sleep-related neuro-endocrine patterns, and, finally, relationships between delta sleep patterns and other biological rhythms such as activity and temperature.

Application of automated REM and slow wave sleep analysis: II. Testing the assumptions of the two-process model of sleep regulation in normal and depressed subjects.

Abnormalities in a two-process model of sleep regulation (a sleep-dependent process, termed Process S, and a sleep-independent circadian process, termed Process C) have been proposed to account for sleep abnormalities in depressive states. The major tenets of the two-process model of sleep regulation as applied to depression are: the level of process S, as reflected by the electroencephalographic (EEG) slow-wave activity, corresponds to the sleep-dependent facet of sleep propensity; the pathognomonic changes of sleep in depressives are a consequence of a deficiency in the build-up of process S. The application of automated rapid eye movement (REM) and delta wave analyses in normal subjects and younger depressed patients supports the model to some extent: The time spent asleep is positively correlated with total delta waves (normals and depressives) and average delta waves (depressives); delta sleep is lower in depressives than in normals; the average delta wave count is significantly reduced in younger depressives over the total night and in non-REM period 1. The model also postulates that measures of phasic REM activity are inversely related to process S, suggesting that process S can be regarded as exerting an inhibitory influence on phasic REM activity.

All-night spectral analysis of the sleep EEG in untreated depressives and normal controls.

Sleep was recorded in nine drug-free depressive patients and nine age- and sex-matched normal control subjects. All-night spectral analysis of the sleep electroencephalogram (EEG) showed a significantly reduced power density in the 0.25-2.50 Hz band in the depressive group. Power density values integrated over the entire frequency range (0.25-25.0 Hz) exhibited for both groups a decreasing trend over the first three non-REM/REM sleep cycles. In each cycle depressives had lower values than controls. The results are consistent with hypothesis that the build-up of a sleep-dependent process is deficient in the sleep regulation of depressive patients.

Inventory of Complicated Grief: a scale to measure maladaptive symptoms of loss.

Certain symptoms of grief have been shown (a) to be distinct from bereavement-related depression and anxiety, and (b) to predict long-term functional impairments. We termed these symptoms of "complicated grief" and developed the Inventory of Complicated Grief (ICG) to assess them. Data were derived from 97 conjugally bereaved elders who completed the ICG, along with other self-report scales measuring grief, depression, and background characteristics. Exploratory factor analyses indicated that the ICG measured a single underlying construct of complicated grief. High internal consistency and test-retest reliabilities were evidence of the ICG's reliability. The ICG total score's association with severity of depressive symptoms and a general measure of grief suggested a valid, yet distinct, assessment of emotional distress. Respondents with ICG scores > 25 were significantly more impaired in social, general, mental, and physical health functioning and in bodily pain than those with ICG scores < or = 25. Thus, the ICG, a scale with demonstrated internal consistency, and convergent and criterion validity, provides an easily administered assessment for symptoms of complicated grief.

Hypoglycemia, enteritis, and spiking mortality in Georgia broiler chickens: experimental reproduction in broiler breeder chicks.

The clinical signs, hypoglycemia, and mortality of "spiking mortality syndrome" were experimentally reproduced. Seven groups of day-old male primary broiler breeder chicks were orally inoculated with tissue and/or fecal-urate homogenates taken from field broilers with spiking mortality syndrome and from field broilers with enteritis and/or runting-stunting syndrome. All homogenates used as inocula were shown by transmission electron microscopy and negative staining to contain arenavirus-like particles. Inocula produced from field broilers with spiking mortality syndrome contained the highest numbers of the arena-virus-like particles and produced the highest percentage of hypoglycemic chicks 13-15 days postinoculation after a 5-to-9-hour fast. These homogenates also produced the most significant differences in mean plasma growth hormone and insulin-like growth factor-1 levels. The significance of the arenavirus-like particles is unknown but is currently being investigated.

Experimental reproduction of hypoglycemia-spiking mortality syndrome in broiler chickens with the use of homogenized brains containing arenaviruslike particles.

Severe hypoglycemia-spiking mortality syndrome was experimentally reproduced in broiler chicks. Inoculum was homogenized brains from 28-day-old commercial broiler chicks with central nervous system signs (50% [v/v] in phosphate-buffered saline with 2% fetal calf serum). Oral inoculations of 1.2 ml of the homogenate were given at 1 day of age to broiler chicks (n = 15). Fourteen days later, chicks were fasted and stressed with a 2-sec cool water spray. Six chicks (40%) developed clinical signs of spiking mortality syndrome and were severely hypoglycemic. Uninoculated control chicks (n = 15) from the same hatch, also fasted and stressed simultaneously, were unaffected. Examination of a banded fraction produced from the inoculum with the use of transmission electron microscopy with negative staining revealed viruslike particles indistinguishable from arenavirus particles stained and examined simultaneously. Avian encephalomyelitis virus was isolated by one of three laboratories attempting virus isolation with the use of embryonating chicken eggs.

Experimental reproduction of severe hypoglycemia and spiking mortality syndrome using field-derived and embryo-passaged preparations.

The clinical signs, enteritis, weight depression, and hypoglycemia of spiking mortality syndrome were experimentally reproduced in broiler breeders and broiler chicks. Inocula included 1) virus-like particles from intestines of chicks with spiking mortality syndrome that had been banded in a discontinuous Renograffin gradient, 2) homogenized darkling beetles collected from litter of farms where spiking mortality syndrome had occurred repeatedly, and 3) homogenized embryos which had been inoculated with the Renograffin-banded material. Arkansas variant infectious bronchitis virus and arenavirus-like particles were identified in the inocula. Serology on samples from surviving chicks suggested the presence of an avian encephalomyelitis virus in one of the inocula. One-day-old (n = 172) and 2.5-day-old (n = 30) chicks were inoculated orally, and some were also injected intraperitoneally or subcutaneously, with 0.5 ml of the inocula. Twelve to fourteen days postinoculation, chicks were fasted for 4-6 hours, then briefly stressed with a cool water spray. Within 1.5 hours, inoculated chicks began dying with severe hypoglycemia and clinical signs of spiking mortality syndrome. Body weights were significantly depressed. Uninoculated controls (n = 130) from the same hatches, also fasted and stressed, were unaffected clinically and were not hypoglycemic. One group (n = 52) of inoculated chicks exposed to a controlled lighting program was unaffected clinically, had significantly higher mean plasma glucose levels, and had significantly less body weight depression than chicks exposed to continuous lighting. We concluded that exposure to controlled amounts of light/darkness can ameliorate much of the hypoglycemia, mortality, and runting-stunting associated with spiking mortality syndrome of chickens. The significance of the viruses and virus-like particles detected in the inocula is currently under investigation.

Isoenzymes of creatine phosphokinase in acute myocardial infarction.

Serial determinations of creatine phosphokinase (CPK) isoenzymes were performed in 400 patients with definite acute myocardial infarction (AMI). The findings were correlated with the clinical course and the findings in another 300 cases of increased CPK levels. MB-CPK, the cardiac fraction, was present in all 400 cases of AMI and in only 5 cases of the 300 patients with high CPK due to causes other than AMI. Based on the magnitude and time course of the total CPK in relation to the MB-CPK, five different patterns are described which correlate with the clinical course. Our findings thus suggest that the determination of CPK isoenzymes can be a most helpful diagnostic tool in the care of the cardiac patient.

Power spectral analysis of EEG in a multiple-bedroom, multiple-polygraph sleep laboratory.

OBJECTIVES: We describe the methods for power spectral analysis (PSA) of sleep electroencephalogram (EEG) data at a large clinical and research sleep laboratory. The multiple-bedroom, multiple-polygraph design of the sleep laboratory poses unique challenges for the quantitative analysis of the data. This paper focuses on the steps taken to ensure that our PSA results are not biased by the particular bedroom or polygraph from which the data were acquired. METHODS: After describing the data acquisition system hardware, we present our signal amplitude calibration procedure and our methods for performing PSA. We validate the amplitude calibration procedure in several experiments using PSA to establish tolerances for data acquisition from multiple bedrooms and polygraphs. RESULTS: Since it is not possible to acquire identical digitized versions of an EEG signal using different sets of equipment, the best that can be achieved is data acquisition that is polygraph-independent within a known tolerance. We are able to demonstrate a tolerance in signal amplitude of +/- 0.25% when digitizing data from different bedrooms. When different data acquisition hardware is used, the power tolerance is approximately +/- 3% for frequencies from 1 to 35 Hz. The power tolerance is between +/- 3 and +/- 7% for frequencies below 1 Hz and frequencies between 35 and 50 Hz. Additional data demonstrate that variability due to the hardware system is small relative to the inherent variability of the sleep EEG. CONCLUSION: The PSA results obtained in one location can be replicated elsewhere (subject to known tolerances) only if the data acquisition system and PSA method are adequately specified.

[Effect of pancreas transplantation on triglyceride metabolism]. / A pancreas-transzplantáció hatása a triglycerid-anyagcserére.

Transplantation of pancreatic gland with systemic venous drainage of the graft causes elevated plasma levels of insulin. To examine lipid metabolism triglyceride clearance capacity, lipolytic enzymes, plasma lipids and lipoproteins were quantified in pancreas-kidney transplant recipients and compared them to lipid parameters of healthy controls and those of patients who had received only kidney transplants. Eleven pancreas-kidney transplant recipients with type I diabetes, 9 non-diabetic kidney transplant recipients as controls for the effects of immunosuppressive medication, and 11 healthy controls were studied. In pancreas-kidney transplant recipients fasting cholesterol, non-HDL cholesterol, triglyceride levels were found 5.5 (+/- 1.0), 3.4 (+/- 0.78) and 1.06 (+/- 0.29) respectively and expressed in mmol/L (mean +/- SE). The results were statistically not different from those of healthy controls. In contrast, non-diabetic kidney transplant recipients cholesterol, non-HDL cholesterol and triglyceride levels were increased to 6.1 (+/- 0.81) (p < 0.05), 4.6 (+/- 1.1) (p < 0.05) and 2.34 (+/- 1.53) mmol/L (p < 0.05). HDL cholesterol averaged 2.08 (+/- 0.36) in pancreas-kidney transplant recipients, clearly higher than that of kidney transplant recipients 1.53 (+/- 0.39) mmol/L (p > 0.01), or of controls 1.61 (+/- 0.37) mmol/L (p < 0.05). In pancreas-kidney transplant recipients postprandial lipaemia was the lowest and lipase activity was the highest compared both to kidney transplant recipients (p < 0.001, p < 0.05) and controls (p < 0.01, p < 0.05). This excellent triglyceride clearing capacity appears to be the result of a high activity of lipoprotein lipase, which, can be explained by the peripheral hyperinsulinaemia.