PubMed Health⌕ Search

Biomedical subjects

R G Kathol

Publications and source records attributed to R G Kathol.

At least 55 records · Page 3Linked to original sources
PubMed1990

Simulated acute hemorrhage through lower body negative pressure as an activator of the hypothalamic-pituitary-adrenal axis.

While insulin induced hypoglycemia is the principle method of producing hypothalamic-pituitary-adrenal stress response, the mechanism by which this occurs may be different from that produced by other stressors. In a pilot study, we explored ways to standardize lower body negative pressure (LBNP), as a simulator of hemorrhage, to determine its utility for future studies of hypothalamic-pituitary-adrenal (HPA) axis function. Reduced atmospheric pressure of -40 mmHg applied at the level of the iliac crests during LBNP rapidly lowers blood pressure in most subjects, simulating acute hemorrhage. In 6 normal subjects, ACTH and cortisol values were measured before, during and after the application LBNP at 0800, 1600 and 2300 hours in the baseline state and at 1600 hours on the day following 1 mg of dexamethasone. Peak ACTH values of 60-250 pg/ml occurred 2 to 10 minutes after the cessation of the stimulus in subjects experiencing presyncope or having a systolic or diastolic blood pressure decrease of greater than 20 mmHg with a rise in pulse of 30 beats per minute or more. There was no significant difference between ACTH responses at different times of day. Peak cortisol values of 25-30 micrograms/dl occurred 15-20 minutes after cessation of the stimulus. In all subjects, administration of dexamethasone greatly attenuated the ACTH response and decreased but did not ablate the cortisol response. In conclusion, these data indicate that LBNP may be used to simulate hemorrhage as a stimulus of the HPA axis. HPA axis changes occur only when physiologic evidence of hypovolemic stress is present. Dexamethasone may be used to modulate the response to this stress paradigm.

Acute Disease↗
PubMed1990

Diagnosis of major depression in cancer patients according to four sets of criteria.

Diagnoses of major depression in 152 cancer patients differed as much as 13% depending on the diagnostic system used. The Beck Depression Inventory and the Hamilton Rating Scale for Depression were useful tools for screening patients with depressive symptoms but frequently misclassified those who had no major depression according to one or more of the criteria-based diagnostic systems.

Adolescent↗
PubMed1989

Direct comparison of urinary free cortisol excretion in patients with depression and panic disorder.

Urinary free cortisol (UFC) excretion in 31 patients with major depression is directly compared to UFC levels in 65 patients with panic disorder and 36 controls. Patients with depression demonstrated significantly higher UFC excretion [43 +/- 37 micrograms/g creatinine (cr)] than patients with panic disorder (29 +/- 13 micrograms/g-cr) or controls (22 +/- 10 micrograms/g-cr) (F = 8.5, df = 129, p less than 0.001). Panic patients with a secondary depression (35 +/- 17 micrograms/g-cr) or those with agoraphobia (34 +/- 14 micrograms/g-cr) had UFC levels that were in-between patients with primary major depression and panic patients without these complications (25 +/- 11 micrograms/g-cr). These findings support the hypothesis that patients with major depression, whether primary or secondary, and those with agoraphobia excrete more UFC than patients with uncomplicated panic disorder. This occurs despite the fact that panic disorder might also be expected to raise the stress-responsive hormone cortisol.

Adult↗
PubMed1989

Psychiatry and internal medicine resident education in an acute care medical-psychiatry unit.

A Medical-Psychiatry Program has been developed at the University of Iowa. It includes a medical-psychiatry unit, a medical-psychiatry lecture series, a medical-psychiatry residency program, and a medical-psychiatry fellowship. The program enables residents pursuing straight psychiatry or internal medicine training to participate in a rotational experience requiring that they evaluate and treat patients for illnesses in both specialties under the supervision of both a staff psychiatrist and internist. During the rotation the resident learns how psychiatric and medical disease in the same patient complicates patient care and the skills needed to diagnose and treat such patients in the climate of their own specialty. The rotation is considered a valuable training experience by the majority of residents going through the rotation.

Combined Modality Therapy↗
PubMed1989

Behavioral performance and seizure activity of lithium-intoxicated Sprague-Dawley rats treated with theophylline.

Male Sprague-Dawley rats were divided into four groups that were treated with various combinations of lithium, saline, and theophylline, i.e., saline/saline, saline/theophylline, lithium/theophylline, and lithium/saline. Neurobehavioral testing of cerebellar and neuromuscular functioning, and determination of the effect of the drug combinations on the animals' seizure threshold concluded that while theophylline increases lithium clearance, it does not exacerbate lithium neurotoxicity.

3-Mercaptopropionic Acid↗
PubMed1989

Pathophysiology of HPA axis abnormalities in patients with major depression: an update.

Four hypotheses have been proposed to explain why nonsuppression on the dexamethasone suppression test occurs in patients with major depression. These include 1) increased metabolism of dexamethasone, 2) decreased sensitivity of pituitary glucocorticoid receptors to dexamethasone, 3) hyperresponsivity of the adrenal gland to ACTH stimulation, and 4) increased central drive of the pituitary from hypothalamic/limbic structures that overrides the action of the dexamethasone. A critical review of the literature suggests that the last hypothesis is most closely supported by the data. Despite this conclusion, factors other than depression may be involved in hypothalamic-pituitary-adrenal axis dysfunction.

Depressive Disorder↗
PubMed1989

Consistent reduction of ACTH responses to stimulation with CRH, vasopressin and hypoglycaemia in patients with major depression.

Eleven patients with major depression and 12 control subjects were administered corticotropin-releasing hormone (CRH), aqueous arginine vasopressin (AVP), and insulin hypoglycaemia (IH) to test for differences in hypothalamic-pituitary-adrenal (HPA) axis function. Patients with major depression demonstrated lower ACTH responses to CRH when compared with controls, and a trend toward such after administration of AVP. Despite lower ACTH responses in patients with depression, there were no differences in cortisol responses to these stimuli. In the CRH and AVP tests, there was no correlation between the basal cortisol and ACTH responses in either controls or patients, but in the IH test there was a negative correlation between these responses for both groups. The ACTH responses to CRH and AVP were positively correlated in controls and patients. Cortisol responses to all three provocative stimuli were positively correlated in both subject groups. These findings are consistent with the hypothesis that hypothalamic or supra-hypothalamic overactivity may be involved in the development of HPA-axis abnormalities in patients with depression.

Adrenocorticotropic Hormone↗
PubMed1988

The effects of intravenous theophylline infusion versus intravenous sodium bicarbonate infusion on lithium clearance in normal subjects.

Ten normal subjects ingested lithium carbonate (600 mg p.o. b.i.d.) for three 1-week intervals. At the end of each weekly interval, subjects' lithium clearances were randomly perturbed for 12 hours with the subject in a supine position by infusing either normal saline (308 mEq), sodium bicarbonate (350 mEq) in normal saline (308 mEq), or theophylline (mean = 14.0 micrograms/ml) in normal saline (308 mEq). Subjects were placed on a 200 mEq/day sodium diet during the lithium clearance perturbation stages of the study. When each patient's normal saline lithium clearance was used as a control, it was found that the theophylline produced a significantly greater % increase in lithium clearance than did the sodium bicarbonate. Theophylline infusions increased patients' individual lithium clearances by 51 +/- 52%, while sodium bicarbonate infusions increased lithium clearances by 0.6 +/- 33%. Theophylline infusions ought to be investigated as an alternative to hemodialysis in lithium intoxications requiring the immediate reduction of lithium concentrations.

Adult↗
PubMed1988

Relationship of urinary free cortisol levels in patients with panic disorder to symptoms of depression and agoraphobia.

Sixty-five patients with panic disorder and 37 matched controls collected 24-hour urine specimens for measurement of urinary free cortisol. Although patients with panic disorder had significantly higher urinary free cortisol levels than control subjects, this difference was accounted for by panic disorder patients with concomitant depression, agoraphobia, or both. Urinary free cortisol excretion was not related to the age of onset of panic disorder, the number of spontaneous panic attacks, or the degree of impairment associated with the disorder. They were related, however, to the level of symptoms on both the Hamilton Rating Scale for Depression and the Hamilton Rating Scale for Anxiety in the entire group of panic patients, but this relationship disappeared when those patients with the complications of agoraphobia and depression were excluded. These data suggest that, as with primary depression, depression secondary to panic disorder, as well as to agoraphobia in panic disorder patients, is associated with hyperactivity of the hypothalamic-pituitary-adrenal axis.

Adult↗
PubMed1988

Partial 11 beta-hydroxylase activity suppression after dexamethasone in patients with major depression.

Eleven beta-hydroxylase activity was assessed by measuring the cortisol to 11-deoxycortisol ratio in 20 control subjects, 38 patients with major depression, and five patients with Cushing's disease before and after 1 mg of dexamethasone. The mean levels of 11 beta-hydroxylase activity did not differ among groups before dexamethasone. After dexamethasone patients with Cushing's disease showed a nonsignificant increase in 11 beta-hydroxylase activity while patients with major depression and controls subjects both showed a decrease. Endogenous depressive patients were no more likely to show high 11 beta-hydroxylase activity than neurotic depressive patients; however, depressed patients with cortisol nonsuppression after dexamethasone were. Post-dexamethasone 11 beta-hydroxylase activity is positively correlated with age in both control subjects and patients with depression.

Adult↗
PubMed1988

HPA axis abnormalities in depressed patients with normal response to the DST.

In order to identify depressed patients with hypothalamic-pituitary-adrenal (HPA) axis abnormalities who have a normal response to the dexamethasone suppression test (DST), the authors administered a series of neuroendocrine tests including insulin-induced hypoglycemia, arginine vasopressin challenge, and a DST. Using standard sensitivity measures, as well as logistic regression, they concluded that many patients with HPA abnormalities are not identified by the DST. These findings suggest that other neuroendocrine tests, which are sensitive to HPA axis abnormalities, may be helpful in subtyping depression on the basis of HPA axis functioning.

Adrenocorticotropic Hormone↗
PubMed1988

Similarities in hypothalamic-pituitary-adrenal axis activity between patients with panic disorder and those experiencing external stress.

Psychologic stressors are less potent stimuli of the HPA axis in humans than physical stressors, but they can cause mild changes in acute ACTH and cortisol production. These changes, however, are generally not of sufficient magnitude or duration to cause measurable changes in UFC excretion. Furthermore, chronic stress leads to an attenuation of the HPA axis response. This basic knowledge concerning psychologic stress helps explain the reason why patients with uncomplicated anxiety/panic disorder, a condition involving similar symptoms, do not demonstrate UFC abnormalities. Panic disorder, when accompanied by depression, however, is associated with an increase in UFC excretion which is probably more related to the depression than the panic state. Interestingly, panic disorder, when accompanied by agoraphobia, also shows an elevation in UFC levels which makes it endocrinologically distinct from uncomplicated panic disorder. The reason for this is unclear. Treatment of the panic disorder with benzodiazepines does not further lower the UFC levels in patients with uncomplicated panic disorder despite clinical improvement, but it does lower UFC levels into the normal range in those with concurrent depression and agoraphobia. Alteration in the UFC level with treatment is only partially related to clinical improvement.

Agoraphobia↗
PubMed1987

Enhanced adrenal sensitivity to exogenous cosyntropin (ACTH alpha 1-24) stimulation in major depression. Relationship to dexamethasone suppression test results.

ACTH alpha 1-24 (cosyntropin) (250 micrograms by intravenous bolus) was given to 38 medicated patients with major depressive disorder (MDD) and to 34 normal control subjects. Patients with MDD had significantly higher plasma cortisol concentrations and significantly higher increases in plasma cortisol levels 60 minutes after cosyntropin infusion than did control subjects. Patients who were nonsuppressors in the dexamethasone suppression test had significantly higher 60-minute cortisol concentrations and cortisol increases than did normal subjects and patients with MDD who were suppressors. There were significant, strongly positive correlations between cortisol secretory responses to cosyntropin and postdexamethasone cortisol concentrations in patients with MDD. These findings confirm that adrenal sensitivity to corticotropin (ACTH) is enhanced in MDD and suggest that this endocrine abnormality may be related pathophysiologically to the resistance of cortisol secretion to dexamethasone suppression.

Adolescent↗
PubMed1987

Stable adrenocorticotropin-stimulated 11-beta-hydroxylase activity but loss of age-related changes in patients with hypercortisolemia.

Eleven-beta-hydroxylase activity was measured before and after acute adrenocorticotrophic hormone (ACTH) stimulation in 28 controls, 25 depressed Dexamethasone Suppression Test (DST) suppressors, 13 DST nonsuppressor patients, and 8 patients with Cushing's syndrome to investigate changes in states of cortisol hypersecretion. Eleven-beta-hydroxylase activity was equivalent among groups both before and after stimulation. Such 11-beta-hydroxylase stability, however, resulted in higher cortisol and 11-deoxycortisol poststimulation levels in both depressed DST nonsuppressors and Cushing's patients than in controls. Basal 11-beta-hydroxylase activity is positively correlated and 11-deoxycortisol is negatively correlated with age in controls and DST suppressors, but not in the patients tested with evidence of cortisol hypersecretion. These findings suggest that in vivo basal 11-beta-hydroxylase activity rises gradually with age, but does not rise after acute administration of exogenous ACTH. The age relationship is lost in states of cortisol hypersecretion, but the lack of response to acute exogenous ACTH is not affected.

Adrenocorticotropic Hormone↗
PubMed1987

The HPA axis response to insulin hypoglycemia in depression.

Dysfunction of the hypothalamic-pituitary-adrenal (HPA) axis, demonstrated by failure to suppress cortisol secretion after dexamethasone, is found in approximately 50% of patients with major depression (MD). In this study, we examined the response of adrenocorticotrophic hormone (ACTH) and cortisol to insulin-induced hypoglycemia in 20 healthy controls and 18 inpatients with MD [12 dexamethasone suppressors (S) and 5 dexamethasone nonsuppressors (NS)]. After the administration of 0.15 U/kg of regular insulin, both controls and patients with MD showed an increase in plasma ACTH and cortisol levels. Controls had a significantly higher ACTH peak (p less than 0.01) and ACTH increment (p less than 0.01) than MD patients. There were no statistically significant differences between patients who were S and NS. Although baseline plasma cortisol levels were significantly higher in MD patients, there were no significant differences in the peak cortisol or increment in plasma cortisol after hypoglycemia between patients with MD and controls or between patients who were S and those who were NS. These findings suggest that a defect exists in the regulation of the HPA axis at the pituitary level in MD and that this defect is not necessarily reflected in the dexamethasone suppression status of the patient.

Adrenocorticotropic Hormone↗
PubMed1987

What you should know about physical evaluations in psychiatric patients. Results of a survey.

Physical illness often initially manifests as a disturbance in thought, behavior, or mood; thus an important aspect of the psychiatric evaluation is differentiating organic disease from "functional" psychiatric disorders. A group of clinically oriented psychiatrists were surveyed about their attitudes and practices regarding medical evaluation in psychiatric patients. Thirty-seven percent of those surveyed performed physical examinations in 60%-100% of their inpatients whereas only 5% performed such examinations on outpatients. Of the 123 respondents, 63 did not perform physical examinations on any of their patients. Twenty-four percent of those who did not perform physicals also did not utilize internists or family practitioners to exclude the possibility of organic disease as a complicating factor in the psychiatric presentation. Those who considered themselves "biologically oriented" were twice as likely to include a physical examination in their inpatient evaluation as those who described themselves as "eclectic" psychiatrists; however, 30% still did no physical examinations in their practice. These findings suggest that though the ability to identify organic illness as a cause for psychiatric symptoms is considered important, psychiatrists often do not utilize the physical examination as a technique in uncovering physical disease.

Data Collection↗
PubMed1987

Evaluation of psychiatric symptoms in patients presenting with symptoms of premenstrual tension syndrome.

The principal psychiatric syndrome seen in patients with premenstrual tension syndrome is depressive disorder. Questions that should be used to evaluate depression are reviewed and the addition of structured questionnaires for the depressive symptoms is not considered useful in this assessment. Other conditions that may or may not be related to the premenstrual period include psychosis (especially depression and mania), alcoholism, anxiety, and bulimia. Brief questioning concerning these conditions can be performed relatively quickly during the clinical evaluation. Second-source information should be obtained when at all possible. If treatable psychiatric illness is identified in those with premenstrual tension, it should be treated as if the psychiatric syndrome alone were present. There is no indication, however, that such treatment will alter the course of the premenstrual condition should it be present as well.

Affective Symptoms↗