Biomedical subjects

N H Kalin

Publications and source records attributed to N H Kalin.

118 records · Page 7Linked to original sources

PubMedDate not supplied

Management of the depressive component of bipolar disorder.

Acute bipolar depression (ABD) and breakthrough depression occurring during maintenance therapy of bipolar disorder are associated with significant morbidity and an increased risk of suicide. Lithium is an effective mood stabilizer for ABD, but its onset of antidepressant action is slow and additional antidepressant therapy is often prescribed. The extent to which other mood stabilizers (e.g., carbamazepine and valproate) have antidepressant activity is unclear. Preliminary initial research suggests three potential advantages that selective serotonin reuptake inhibitors have over tricyclic antidepressant for ABD: possibly greater efficacy, fewer adverse effects, and a lower frequency of antidepressant-induced mania. Bupropion may also have significant advantages. However, further research is needed to confirm these findings. Monoamine oxidase inhibitors are the antidepressant of choice for atypical bipolar depression. Electroconvulsive therapy (ECT) has the highest response rate of all treatments for ABD. Further research is needed to explore combination treatments with mood stabilizers and antidepressants for the effective treatment of ABD.

Acute Disease↗

PubMedDate not supplied

Associated endocrine, physiological and behavioral changes in rhesus monkeys after intravenous corticotropin-releasing factor administration.

The intravenous (IV) administration of synthetic ovine corticotropin-releasing factor (CRF) (10 and 125 micrograms/kg) to chair restrained rhesus monkeys stimulated the pituitary-adrenal axis. At these doses, increases in plasma concentrations of adrenocorticotropic hormone (ACTH) and cortisol were associated with blood pressure decreases and behavioral effects. These data demonstrate that synthetic ovine CRF (10 and 125 micrograms/kg) administered IV to the rhesus monkey results in associated endocrine, physiological, and behavioral changes.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Corticotropin-releasing factor administered intraventricularly to rhesus monkeys.

Synthetic ovine corticotropin-releasing factor (CRF) administered intraventricularly (ICV) to rhesus monkeys resulted in endocrine and behavioral changes. At doses of 20 and 180 micrograms, CRF stimulated the pituitary-adrenal axis in four chair-restrained monkeys. These monkeys showed concomitant increases in arousal. To study these animals in a less restrictive setting, three of the monkeys later received CRF ICV (20 and 180 micrograms) in their home cages. At the 180-micrograms dose the monkeys exhibited a combination of huddling and lying down behavior. These behavioral effects did not seem to be due to alterations in blood pressure.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Effects of synthetic ovine CRF on ACTH, cortisol and blood pressure in sheep.

Intravenously administered synthetic ovine CRF at doses of 0.1, 1.0 and 10.0 micrograms/kg increased plasma ACTH and cortisol concentrations in a dose-dependent fashion in unanesthetized sheep. In two unanesthetized sheep, aortic blood pressure remained relatively unaffected after the intravenous administration of CRF at 5 and 20 micrograms/kg. These results suggest that peripherally administered ovine synthetic CRF specifically stimulates the sheep pituitary-adrenal axis. Unlike other species receiving intravenous synthetic ovine CRF, sheep did not show hypotensive effects.

Adrenocorticotropic Hormone↗

PubMedDate not supplied

Shuttlebox avoidance in rhesus monkeys: effects on plasma cortisol and beta-endorphin.

Groups of monkeys either extensively pretrained to avoid shocks in a shuttlebox or with minimal prior experience were compared for plasma cortisol and beta-endorphin levels immediately following: (1) an exposure to the box with no shock, (2) the box providing repeated inescapable shocks or (3) a re-exposure to the box, again with no shock presentation. Mere exposure to the unfamiliar box elevated plasma cortisol just as much as exposure + shock did when inexperienced monkeys were tested. However, animals with a history of previously successful shock avoidance showed smaller elevations when exposed to the box alone, than they did when inescapable shock was received. Plasma beta-endorphin levels following shuttlebox exposure showed only a sporadic pattern of elevations in either inexperienced or pretrained monkeys. However, levels of beta-endorphin as determined under control conditions in the home cage were lower in pretrained animals, as were plasma levels of cortisol. The results indicate that behavioral factors may effect plasma cortisol and beta-endorphin following both acute and chronic shuttlebox experience.

Animals↗

PubMedDate not supplied

Episodic secretion of ACTH in rats.

While the circadian rhythm of pituitary adrenocorticotropin (ACTH) secretion has been well characterized, the ultradian rhythm has been less thoroughly investigated. To study the episodic nature of ACTH secretion, unrestrained, unanesthetized rats were bled continuously through indwelling jugular venous cannulae and blood sampled for up to 75 minutes at one-minute intervals beginning at 1100 hr (n=6) or 1730 hr (n=4). Sporadic low-amplitude micropulses were observed at both times of day. In addition, infrequent "superpulses" were observed in the evening. Analysis of pulse parameters revealed a significant (p less than 0.001) difference in pulse amplitude but no difference in pulse frequency of interpeak interval between morning and evening. As with other episodically secreted hormones, the threshold for pulse identification and the sampling interval were found to influence the observed pulse parameters.

Activity Cycles↗

PubMedDate not supplied

Pulsatile ACTH secretion: variation with time of day and relationship to cortisol.

It has long been known that ACTH is secreted in an episodic fashion demonstrating circadian and ultradian rhythms. High intensity venous sampling has recently revealed that in addition to these larger ultradian fluctuations in hormone levels, plasma ACTH in rats demonstrates high frequency, low amplitude oscillations which have been called "micropulses." These micropulses were not detected in previous studies due to sampling intervals of greater than 5 minutes. To investigate the presence of these ACTH micropulses in a primate species, blood samples were drawn from six chair-restrained rhesus monkeys at one-minute intervals for up to 70 minutes and plasma was assayed for immunoreactive ACTH. To assess the variation in ACTH micropulse parameters with time of day and the relationship to cortisol secretion, four of the monkeys were sampled for three 70-minute periods beginning at 0530, 1100, and 1730 hours, and plasma was assayed for immunoreactive ACTH and cortisol. Analysis of the data revealed that ACTH and cortisol are secreted in micropulses in rhesus monkeys with marked individual variation in the pattern of secretion and a concurrence of approximately 75% of ACTH and cortisol micropulses. Difference in pulse amplitude but not frequency appeared to contribute to the circadian variation in mean ACTH levels and a sampling interval of two minutes appeared to be adequate for accurately identifying micropulses of ACTH.

Activity Cycles↗

PubMedDate not supplied

A follow-up study of thirty hospitalized bulimics.

Thirty normal-weight female bulimics were followed up 2-5 years following hospital admission using semistructured interviews and psychometric measures. Inasmuch as bulimia was only recently designated a distinct disorder, questions have emerged with regard to its clinical course and diagnostic validity. Results of this investigation suggest that bulimia displays a chronic but tractable course in that the majority of the patients continued to report bulimic behaviors at follow-up but the symptom intensity was greatly reduced from admission. The characterization of three bulimic outcome groups suggests that the outcome pattern of this disorder is heterogeneous, with some patients becoming symptom-free and others remaining severely afflicted. The durability of the symptoms and the failure of new psychiatric syndromes to emerge in the follow-up period is evidence that bulimia is a distinct diagnostic entity and not a variant of another underlying condition. The methodologic limitations of this study are addressed.

Adolescent↗

PubMedDate not supplied

Salivary cortisol as a predictor of socioemotional adjustment during kindergarten: a prospective study.

This study, based on a sample of 172 children, examined the relation between average afternoon salivary cortisol levels measured at home at age 4.5 years and socioemotional adjustment a year and a half later, as reported by mothers, fathers, and teachers. Cortisol levels were hypothesized to be positively associated with withdrawal-type behaviors (e.g., internalizing, social wariness) and inversely related to approach-type behaviors, both negative and positive (e.g., externalizing, school engagement). Higher cortisol levels at age 4.5 predicted more internalizing behavior and social wariness as reported by teachers and mothers, although child gender moderated the relation between cortisol and mother report measures. An inverse relation was found between boys' cortisol levels and father report of externalizing behavior. A marginal inverse relation was found between child cortisol levels and teacher report of school engagement. Behavior assessed concurrently with cortisol collection did not account for the prospective relations observed,suggesting that cortisol adds uniquely to an understanding of behavioral development.

Adaptation, Psychological↗

PubMedDate not supplied

Neuroendocrine changes in patients undergoing whole body hyperthermia.

A phase I study of whole body hyperthermia (WBH) (52 treatments/12 patients) utilizing a radiant heat device has been completed. This study incorporated a temperature escalation scheme from 39.5 to 41.8 degrees C for up to 150 min. Pain relief or a sense of well being was observed post-WBH in the first three patients entered in this study. We postulated that WBH might result in increases in the opiate peptide beta-endorphin. Therefore we elected to study prospectively the next six patients entered in this study to test the hypothesis that WBH stimulates the neuroendocrine axis. Results are reported which show thermal-induced increases in plasma levels of beta-endorphin as well as prolactin, ACTH and cortisol.

Adrenocorticotropic Hormone↗