Somatomedin-C levels in healthy young and old men: relationship to peak and 24-hour integrated levels of growth hormone.

We investigated the relationship between growth hormone secretion and somatomedin levels as a function of age in normal healthy men. There was a substantial decrease with age in somatomedin levels from 0.95 +/- 0.

Plasma norepinephrine in normal young and aged men: relationship with sleep.

This study explored the relationship between age-related elevations of plasma norepinephrine (NE) levels (thought to reflect heightened sympathetic nervous system activity) and sleep. Plasma NE levels were consistently and significantly greater in 8 aged than 10 young men across a 24-hr study period. For both groups, plasma catecholamine levels remained stable near bedtimes and rise times and during spontaneous and experimentally induced nighttime awakenings; reversal of the sleep/wake pattern (nighttime wakefulness, daytime sleep) had little effect on the 24-hr plasma NE or sleep patterns, indicating that elevated NE cannot be attributed to altered sleep/wakefulness per se.

Rapid eye movement sleep measures of Alzheimer's-type dementia patients and optimally healthy aged individuals.

It has been suggested that rapid eye movement (REM) sleep measures may be useful in the differential diagnosis of affective disorders. To determine what changes, if any, of REM measures occur in Alzheimer's dementia we examined the REM sleep of nine control and nine mild, nine moderate, and nine severe dementia subjects with probable Alzheimer's disease (AD). Control and mild and moderate AD groups were screened to exclude major depression.

Circadian temperature variation in healthy aged and in Alzheimer's disease.

Circadian temperature variation was monitored in healthy older adults and in health-, age-, and sex-matched Alzheimer's dementia patients. Oral and rectal temperatures were analyzed for mean level, amplitude, and phase using cosinor analyses. Mean 24-hour temperature level was not altered by dementia.

The clinical utility of the dementia rating scale for assessing Alzheimer patients.

Community residing patients with mild (n = 18) or moderately severe (n = 16) Alzheimer's disease and controls (n = 23) were given Mattis' Dementia Rating Scale (DRS) and a brief measure of confrontation naming selected from the Boston Naming Test (BNT). The DRS was shown to be a reliable and clinically useful measure of mental status in patients with Alzheimer's disease. The DRS subscales and the BNT had excellent internal consistency reliabilities and the total DRS score (TDRS) was shown to be generally unrelated to gender and education.

Loss of circadian rhythmicity in blood testosterone levels with aging in normal men.

Previous studies concerning the relationship of serum testosterone levels to aging in normal men have yielded apparently inconsistent results. Studies performing blood sampling in the morning have often shown an age-related decrease in testosterone levels, while those using afternoon samples have failed to show such a decrease. These results suggested to us the possibility that the circadian rhythm in serum testosterone levels might be altered with normal aging in men.

Sodium-restricted diet increases nighttime plasma norepinephrine and impairs sleep patterns in man.

Plasma norepinephrine levels in 10 healthy young males were significantly elevated after 3 days of a low sodium (less than 500 mg/day) diet. The low sodium diet was also associated with disturbed sleep patterns: decreased rapid eye movement and slow wave sleep and increased wakefulness. These sleep changes are similar to those seen in normal aged adults, who also undergo elevations of daytime and nighttime plasma norepinephrine.

Sleep apnea: relationship to age, sex, and Alzheimer's dementia.

The relationship of sleep apnea to age, sex, and Alzheimer's dementia was investigated in 45 elderly subjects and 10 young males, all nonobese, normotensive, nonsmoking, with no sleep complaints and no medical problems other than Alzheimer's disease. Mean apnea/hypopnea index [(AH)I] was significantly greater in elderly males than in young males or elderly females. Mean (AH)I and percentage of subjects with an (AH)I greater than 5 in the Alzheimer groups were not significantly different from age and sex-matched controls.

Sleep, EEG and mental function changes in senile dementia of the Alzheimer's type.

Sleep, EEG and mental function variables were studied in 44 subjects diagnosed as having probable senile dementia of the Alzheimer's type (SDAT) and 22 controls matched for age and minimal depression. Results indicate that sleep, EEG and mental function variables all undergo significant change even in the early, mild stage of SDAT, with further change in the moderate and severe stages of dementia. Mental function variables also underwent significant decline across levels of dementia.

Effect of phenobarbital on sleep and nighttime plasma growth hormone and cortisol levels.

The acute and chronic effects of phenobarbital and phenobarbital withdrawal on sleep patterns and on plasma growth hormone (GH) and cortisol fluctuations occurring during sleep were studied. Before bed, five healthy men, aged 21 to 25, were given a placebo on three baseline nights, phenobarbital (100 mg p.o.

Multiple serum inhibitors of lectin-induced lymphocyte proliferation in nephrotic syndrome.

Inhibitory activity on PHA- and Con A-induced lymphocyte proliferation was observed in the serum of 29 patients with nephrotic syndrome (NS); this inhibitory activity was present both in steroid-sensitive nephrotic syndrome (SSNS; 18 patients) and in NS due to other glomerulopathies (11 patients). In order to characterize the inhibitory activity, peripheral blood lymphocytes from normal donors were stimulated with various concentrations of Con A in culture medium supplemented with: (1) 20% SSNS serum, (2) various concentrations (1, 5 and 20%) of either SSNS serum or normal human serum (NHS) and (3) 20% of a serum prepared by mixing different proportions of SSNS and NHS. The results suggest that the inhibitory activity is due to at least two different factors: (a) inhibitor(s) acting competitively with the lectin Con A, and (b) inhibitor(s) neutralized by factor(s) present in NHS.

Receptors for peanut agglutinin on a high percentage of human cord-blood lymphocytes: phenotype characterization of peanut-positive cells.

The results of this study show that a high percentage of human cord-blood lymphocytes bears receptors for peanut agglutinin. Determination of the presence of other lymphocyte markers (E rosettes, membrane immunoglobulins, alpha-naphthyl-acetate esterase, Ia antigens) in the peanut-positive cells indicated that they include both T and B cells. The peanut receptor, also expressed by blast cells of most acute, but not chronic, leukemias, seems to be a marker of immaturity for both T- and B-lymphocyte subsets in man as it is in the mouse.

On the use of repeated measures designs in psychopharmacology.

A popular paradigm in psychopharmacology is the repeated measures design. Unfortunately the test of equal means across the repeated trials requires an assumption that is often untenable and which can lead to erroneous interpretations. In order to minimize this bias three approaches have been suggested.

Effects of interference stimuli on the acquisition of learned aversions to foods in the rat.

A learned food aversion paradigm was developed to investigate characteristics of aversion learning likely to be involved in nutrient selection. The development of aversions to a relatively familiar, complete food was examined in rats with continuous access to that food. Learned food aversions were observed which were specific to the particular diet present during a sequence of toxic drug injections.

Reliability of alpha-naphthyl-acetate esterase staining of blood smears for the enumeration of circulating human T lymphocytes.

Cytocentrifuged preparations of glutaraldehyde-fixed E rosettes were stained for acid alpha-naphthyl-acetate esterase activity (ANAE). On average, 84% of the rosette-forming cells (E+) also stained positively for the enzyme activity (A+). ANAE staining of blood smears of thirty-three healthy controls was compared to E rosetting by a conventional method.

A rapid unfavorable outcome of Wegener's granulomatosis in early childhood.

Wegener's Granulomatosis was suspected in a 27-month-old female with a nodular, necrotizing lesion of the nose, diffuse subcutaneous nodules, and erythematous desquamation of the entire body. From 20 months of age on she had a purulent nasal discharge, recurrent infections of the upper and lower respiratory tract, a Coombs positive anemia, and enlargement of the spleen and liver. Treatment with azathioprine and corticosteroids produced transient improvement but three months later a dramatic relapse occurred.

Evidence for withdrawal from caffeine by rats.

Injections of caffeine produced avoidance of a novel flavor. Rats which had previously received injections of caffeine on each of twelve days avoided a novel solution which had been associated with the absence of caffeine. This and other controls suggest that physiological withdrqwal from caffeine is the mechanism for this avoidance.

Conditioned insulin secretion and meal feeding in rats.

Previous researchers have reported that rats placed upon a feeding regimen such that they receive only 2 hr of food per day (meal-fed rats) develop hyperinsulinemia at the time of the day associated with feeding, even in the absence of food. Controls fed ad lib had no such response. In a series of several experiments, meal-fed rats had elevated insulin levels at only the specific time of the day associated with feeding, and the increment of insulin at that time could be eliminated with atropine.

Caffeine: preferential consumption by rats.

The present experiment explored the effect of forced daily consumption of large amounts of caffeine (analogous to that of heavy coffee drinkers) upon the subsequent intake of caffeine in a free-choice situation. It was found that forced caffeine consumption is directly related to subsequent free-choice intake and that a flavor associated with the forced caffeine is not preferred.