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Biomedical subjects

P Coble

Publications and source records attributed to P Coble.

At least 19 recordsLinked to original sources
PubMed1987

Prolactin secretion during sleep: a comparison between depressed patients and healthy control subjects.

Although several neuroendocrine abnormalities have been described in depressed patients, relatively little attention has been paid to the pattern of prolactin secretion during sleep. Sleep disturbances are frequently found in depressed patients, and the sleep electroencephalogram (EEG) typically shows significant changes in the first and last 100 min, when prolactin secretion frequently occurs. In this study, carefully defined inclusion criteria were used to ensure comparability in the quality of the sleep maintenance, so that the pattern of sleep-related prolactin secretion in a group of 26 depressed inpatients could be compared to that in a group of 20 healthy control subjects. Starting from sleep onset, the patients did not show any statistically significant difference in either the serum prolactin concentration or the pattern of integrated prolactin secretion relative to the control subjects. A statistically significant relationship between prolactin secretion and the REM-non-REM sleep cycle could not be demonstrated in these subjects.

Adult↗
PubMed1984

Effect of nocturnal intravenous cannulation upon sleep-EEG measures.

The effect of an indwelling intravenous cannula on sleep-EEG measures has not been extensively documented despite its relatively frequent use in a variety of clinical studies. When the sleep EEGs from 30 healthy subjects were critically examined, no changes in sleep architecture were found. However, there were significant differences in the distribution of sleep latency, maintenance, and efficiency, with many subjects showing a reduction in the latter two items on the night of cannulation. A decrease in sleep maintenance of greater than 7.5 on the night of cannulation has been used to operationally define an unsatisfactory cannulation study which accounted for 43% of our subjects. It was striking that this group could also be identified by having higher REM densities in each REM period on the previous two nights in the sleep laboratory. This was especially true for the second REM period on the second night when only three of those subjects with subsequent unsatisfactory studies had a REM density less than 0.9. When this criterion was applied to a new group of 19 subjects, 13 were correctly classified with respect to subsequent changes in sleep maintenance before the cannulation study was conducted. It therefore appears possible that REM-sleep measures can be used to predict which subjects will have disrupted sleep on a subsequent cannulation night. Since sleep disruption can significantly mask patterns of hormone secretion, it is essential to monitor the sleep-EEG during such studies.

Adolescent↗
PubMed1979

Imipramine and EEG sleep in children with depressive symptoms.

Depression in children is currently an area of considerable controversy, as is the use of potent psychopharmacologic agents in children. Since EEG sleep techniques have proven to be useful in understanding the mechanisms of depression in adults and in predicting their response to antidepressants, a pilot study employing these techniques was undertaken in a population of hospitalized children. The EEG sleep of 12 children with significant depressive symptomatology was first examined after a two-week drug-free period and again approximately three weeks later when an optimum dose of imipramine had been maintained for at least 7 -- 10 days. Changes in sleep continuity, as reflected in increased wakefulness and a decreased sleep efficiency, as well as an increase in Stage 2 and a decrease in Stage 4 sleep, were observed throughout the entire sample. REM suppression was also noted, but tended to be most pronounced in those children who improved on imipramine.

Adolescent↗
PubMed1979

MAO activity and EEG sleep in primary depression.

Platelet monoamine oxidase (MAO) activity and electroencephalographic (EEG) sleep measures were examined in 56 drug-free hospitalized patients with primary depression as defined by the Research Diagnostic Criteria. The group included 35 females and 21 males with a mean age of 42.6 +/- 1.4 years. Platelet MAO and EEG sleep data were compared for the group as a whole and separately for the unipolar, bipolar, male, and female subgroups. No significant relationships could be demonstrated for the entire group or for the unipolar, male, or female subgroups. However, an inverse relationship between MAO activity and REM sleep percent was noted in the bipolar subgroup (p < 0.02). While changes in REM sleep have been relatively firmly established in primary depression, the relationship of MAO to depression and to REM sleep remains unclear.

Adult↗
PubMed1979

An automated analysis of REM sleep in primary depression.

The REM sleep of 23 nonpsychotic patients with primary depression was studied by means of an automated REM analyzer during a drug-free period and again during amitriptyline administration. Initial drug administration (50 mg) was associated with an immediate reduction in the number, average frequency, and average size of the rapid eye movements. The average REM size remained suppressed with continued drug administration while the average REM frequency showed a rebound which was responsible for a partial recovery of the number of REMs and total REM intensity to predrug levels. With regard to individual REM periods, REM frequency and REM intensity were redistributed during tricyclic administration so that the second REM period became more "intense" than the first REM period. This automated REM analysis technique provides an objective set of measures for characterizing discrete aspects of REM sleep during a depressive episode and for evaluating the changes in REM sleep during psychotropic trials.

Adult↗
PubMed1978

REM sleep in primary depression: a computerized analysis.

REM sleep in 35 inpatients with primary depression was automatically analyzed for 7 consecutive nights during placebo administration. For the total night of sleep, as well as each individual REM period, the number of REMs, their total voltage integral over time, the sum of their durations and the average REM size were automatically calculated. Validity of these automated REM measures was established by significant correlations with manually scored REM measures. Changes in REM sleep across the night were also investigated. Similar to findings in normal subjects, REM time did not change from REM period to REM period. Average REM size increased significantly from REM period 2-3 and 3-4. Contrary to what is seen in normal subjects, REM frequency was high during the first REM period, significantly decreased from the first to second REM period and then remained constant. Finally, a significant inverse correlation between REM frequency for the first REM period and REM latency was noted. This pattern of REM sleep is interpreted as indicating a high pressure for phasic REM at the beginning of the night which is dissipated by the first REM period.

Adult↗
PubMed1978

The application of EEG sleep for the differential diagnosis of affective disorders.

On the basis of two EEG sleep criteria, REM latency and REM activity, the authors achieved 81% accuracy in distinguishing between 47 patients with primary depression and 48 patients with secondary depression using discriminant analysis. Sleep efficiency, the percentage of delta sleep, and the percentage of REM sleep discriminated between psychotic and nonpsychotic subgroups in the group with primary depression with 75% accuracy. REM activity and intermittent nocturnal awakening accurately discriminated two subtypes of patients with secondary depression at a level of 81%. These results suggest that EEG sleep measurements can yield significant data to aid in differential diagnosis in psychiatry.

Adult↗
PubMed1978

Amitriptyline and EEG sleep in depressed patients: I. Drug effect.

The paucity of studies on the tricyclic antidepressants led us to conduct an investigation on 30 drug-free patients treated with amitryptyline in a double-blind protocol over a 4-week period. Consistent with previous reports, there was an immediate REM suppression on 50 mg, which was more pronounced at the 100-mg level. However, no significant incremental changes were noticed on 150 or 200 mg with regard to REM sleep suppression. Drug administration was associated with changes in other sleep variables such as stage 1 percent, stage 2 percent, and various measures of sleep continuity. The incomplete tolerance of the drug on certain REM sleep variables enhances our understanding of amitryptyline effects on the EEG sleep of depressed patients.

Adult↗
PubMed1977

Amitriptyline plasma levels and clinical response in primary depression.

Sixteen patients with primary depression were treated for 4 wk with amitriptyline. After clinical diagnoses were determined, patients entered a double-blind protocol (amitriptyline or placebo) and their clinical status was determined with the Hamilton Depression Rating Scale by raters blind to the drug type, its dosage and plasma levels. Amitriptyline (AT) and nortriptyline (NT) plasma levels were assayed twice weekly by gas chromatography-mass spectrometry. In the 16 patients, a negative correlation between the Hamilton Score and the mean total tricyclic level (p less than 0.01), as well as with individual plasma levels, was found at the end of the treatment period. When the group was divided into clinical responders and nonresponders, the mean total tricyclic (AT + NT) levels discriminated the two groups by day 12 (p less than 0.001) as well as at the end of the protocol (day 26, 88% of the patients were classified correctly if an arbitrary level of 200 ng/ml total tricyclic plasma level was chosen). These results strongly suggest the presence of a positive correlation between plasma levels and clinical improvement in patients with primary depression.

Adult↗
PubMed1976

Rapid eye movement sleep density. An objective indicator in severe medical-depressive syndromes.

The electroencephalographic sleep patterns of 12 patients with a final diagnosis of primary depression and those of 12 patients admitted to the Clinical Research Unit with this diagnosis, but subsequently also found to be suffering from severe medical disease, were compared. Patients with depression concurrent with severe medical disease have significantly less phasic conjugate rapid eye movement (REM) activity during REM sleep than subjects with the diagnosis of a primary depression. These findings suggest that quantification of REM density may be used clinically to distinguish between medical-depressive syndromes and primary affective disorders.

Adolescent↗