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Biomedical subjects

T Kosten

Publications and source records attributed to T Kosten.

At least 37 records · Page 2Linked to original sources
PubMed1989

Deficits in conditioned heart rate and taste aversion in area postrema-lesioned rats.

Previous studies have shown that area postrema (AP) lesions cause deficits in conditioned taste aversion in the rat. They also lead to chronically lowered heart rate which can be reversed by the animals' increased appetite for and ingestion of hypertonic saline. Although not previously examined in conditioned taste aversion, changes in autonomic nervous system activity as reflected in heart rate may be an important aspect of conditioning. The present study investigated the effects of AP lesions on heart rate conditioned responses (CRs) and unconditioned responses (UCRs). Two groups of AP lesioned and sham-operated rats, one that did and one that did not drink saline solution to raise heart rate, were studied. Both LiCl and scopolamine, which have opposite effects on heart rate, were the unconditioned stimulus (UCS) agents in two separate studies. In intact rats, LiCl-mediated conditioned taste aversion was associated with decreased conditioned stimulus (CS) intake and decreased heart rate Both effects were blunted by AP lesions, although all rats displayed heart rate UCRs to LiCl. The AP rats that drank saline behaved like intact rats exhibiting both a conditioned taste aversion and conditioned heart rate responses to the CS. Although CS intake decreased, no heart rate CRs developed with scopolamine. Scopolamine-mediated conditioned taste aversion was attenuated in both saline and non-saline drinking AP-lesioned groups. Thus, when conditioned taste aversion was associated with heart rate CRs, the AP lesion-induced deficit was counteracted by saline ingestion. Conversely, when there were no heart rate CRs, conditioned taste aversion was disrupted by the lesion regardless of saline ingestion.

Animals↗
PubMed1989

Serum concentrations of circulating thyroid hormones in a group of depressed men.

Levels of circulating total thyroxine (TT4), free thyroxine (FT4), total triiodothyronine TT3 and thyrotropin (TSH) were determined in 27 men with unipolar major depressive disorder ages 24-50, mean +/- SEM 36.9 +/- 2.9 years, and 38 healthy controls (HC) ages 20-50, mean +/- SEM 34.2 +/- 3.1 years. No significant differences were observed between HC and depressed men with regard to TT4 and FT4. Mean TT3 levels were lower, and mean TSH levels higher in depressed patients than in HC, p less than 0.05 for both, compatible with possible subclinical primary hypothyroidism in depressed patients. Consistent with this, an inverse correlation between basal TSH values and TT3 (r = -0.38, p less than 0.05) was noted in depressed but not in HC subjects.

Adult↗
PubMed1988

Treating cocaine abusing methadone maintenance patients with desipramine.

Intravenous cocaine use in methadone patients has become a major problem because of both the complications of cocaine use and the potential spread of AIDS. During an eight week open trial we found that desipramine reduced cocaine craving and use in eight cocaine abusing methadone maintenance patients compared to eight patients getting no medication execept methadone.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Clonidine and naltrexone in the outpatient treatment of heroin withdrawal.

Clonidine hydrochloride (an alpha-2 adrenergic agonist) and naltrexone hydrochloride (an opioid antagonist), given in combination, provided a safe and effective treatment of abrupt opioid withdrawal over 5 days in an outpatient/day setting. Before starting the clonidine, a naloxone challenge test was used to verify and quantify opioid dependence, and the naloxone challenge test score was then used to determine initial medication doses. Initial naloxone challenge test scores predicted subsequent patient discomfort during the 5-day clonidine-naltrexone protocol. Twelve of 14 (86%) heroin users successfully withdrew from opioids and simultaneously initiated naltrexone maintenance.

Adult↗
PubMed1985

Clonidine in outpatient detoxification from methadone maintenance.

Inpatient narcotic detoxification with clonidine hydrochloride has been used since 1978. Outpatient withdrawal, potentially more useful, has not been adequately studied. This report describes a double-blind random assignment of 49 methadone hydrochloride-maintained patients whose dose had been lowered to 20 mg. Twenty-five were detoxified using methadone at 1-mg decrements, 24 by abrupt substitution with clonidine. Approximately 40% of both groups achieved successful detoxification, with one third maintaining abstinence over the subsequent six months. The groups were also largely equivalent on withdrawal symptoms, but the clonidine group experienced symptoms in the first half of the study and the methadone group in the second half. Clonidine appears to be a safe and efficacious outpatient treatment for opiate withdrawal, although the results were less favorable than those obtained in open or inpatient studies.

Adult↗
PubMed1985

Adrenalectomy reduces peripheral neural responses to gustatory stimuli in the rat.

In the rat, sodium need leads to an increase in sodium intake, which depends on salt taste sensitivity. The adrenalectomized rat, because of excessive body sodium loss, has been an important animal model for studying the physiological mechanisms underlying salt ingestion. In order to investigate the mediation by peripheral taste responsivity of changes in salt intake, multiunit responses of the chorda tympani nerve to various concentrations of sodium chloride, potassium chloride, lithium chloride, hydrochloric acid, and quinine hydrochloride were recorded from adrenalectomized and control rats. In order to control for a generalized decrease in sensory sensitivity, recordings from the auriculotemporal nerve to tactile stimulation of the pinna were also performed. There were no group differences in amplitude of the integrated neural responses to tactile stimulation. The largest decrease in gustatory responsivity occurred for suprathreshold concentrations of sodium chloride and lithium chloride. The data are discussed with reference to possible mechanisms underlying this neural alteration and to the role that reductions in salt taste responsivity play in mediating increases in salt intake.

Adrenal Glands↗
PubMed1985

Success and failure at outpatient opioid detoxification. Evaluating the process of clonidine- and methadone-assisted withdrawal.

Two controlled trials have suggested that clonidine can be used on an outpatient basis to assist in opioid withdrawal, but that rates of successful detoxification do not exceed those obtained with gradual methadone reduction. This study examines the process of clonidine-and methadone-assisted detoxification to provide information about the timing and severity of withdrawal symptoms and side effects associated with each of the two methods. Derived from a double-blind clinical trial with randomized treatment assignment, data are presented which might guide the clinician in the choice of detoxification methods. In this study, subjects in either treatment condition had a success rate of approximately 40% and most subjects experienced at least moderate withdrawal discomfort in the areas of difficulty sleeping, feeling "blah," and craving. In both treatment groups the best predictor of detoxification failure was a high level of psychological symptoms at the onset of the study. Compared with gradual methadone reduction, clonidine treatment resulted in higher levels of withdrawal symptoms and side effects, earlier onset of withdrawal discomfort, earlier attrition, earlier termination of withdrawal discomfort, and a posttreatment course of drug use that was more consistent with success status during the study treatment.

Adult↗
PubMed1985

Acute bereavement, threatened loss, ego defenses and adrenocortical function.

In this study of 43 acutely bereaved widows and widowers and a comparison group of 24 nonbereaved married persons who experienced critical illness in a spouse, we found no evidence of higher levels of affective arousal, higher levels of adrenocortical activity, less effective ego defenses, or higher levels of defensive work among bereaved persons by comparison with nonbereaved persons. Furthermore, we failed to observe expected relationships between ego defensive function and adrenocortical activity among either bereaved or nonbereaved persons. These observations are consistent with one previous study of bereaved parents.

Arousal↗
PubMed1984

Area postrema: part of the autonomic circuitry of caloric homeostasis.

Investigations in which lesion techniques are used suggest a role for the area postrema (AP) in caloric homeostasis. Ablations of the AP in rat are associated with temporary hypophagia, hypodipsia, and rapid body weight loss. This is followed by a steady period of relatively normal eating and drinking and body weight gain. This steady period is characterized specifically by lowered body weight maintenance levels, overingestion of palatable foods, and attenuated taste aversion learning and glucoprivic feeding. These effects cannot be attributed simply to lesions of central terminations of gustatory and visceral afferents. The AP may be involved in feeding behaviors that are triggered by chemical signals in the blood or cerebrospinal fluid. In addition, the AP along with the adjacent nucleus tractus solitarii (NTS) seems to be part of the central autonomic system subserving caloric homeostasis; this system includes the lateral hypothalamus, which has a well-documented role in energy balance. The contribution of the AP along with the NTS must be considered with respect to their relationship to other structures within this system.

Animals↗
PubMed1983

Enhanced saline intake and decreased heart rate after area postrema ablations in rat.

The area postrema (AP) is a circumventricular organ located in the dorsal medulla. Previous studies found that AP lesions lead to increased saline ingestion in the rat. The salt appetite was thought to be a result of primary disruptions in sodium regulation or in cardiovascular regulation. To assess this we measured food and fluid intakes, urinary electrolyte and aldosterone concentration, and blood pressure and heart rates in AP lesioned and control animals during a period of normal sodium intake and during a period of excessive sodium intake. Rats with AP lesions exhibited sodium appetite but not natriuresis. In fact, sodium intake greatly exceeded output. Their urinary aldosterone levels were similar to those of control animals during both periods. The lesioned rats also had lowered heart rates, yet, their blood pressures were similar to control animals. These results are discussed with reference to a possible role of the AP in satiety and in maintaining homeostasis.

Aldosterone↗
PubMed1983

Prenatal and early postnatal sodium chloride intake modifies the solution preferences of adult rats.

To determine whether the concentration of sodium chloride (NaCl) consumed early in life influences the degree of NaCl preference later in life, adult female rats were maintained on diets containing either 0.12, 1.0, or 3.0% NaCl throughout pregnancy; their offspring were continued on these same diets to day 30 of life. Thereafter, all offspring were maintained on a diet containing 1.0% NaCl. At 90 days of age the animals were given a two-bottle preference test between water and various concentrations of NaCl, glucose, and KCl solutions. After preference testing the livers and adrenal glands were removed and weighed. Both male and female offspring raised on the high salt diet showed an elevated preference for NaCl solutions as adults. The effect was nonspecific as the males also exhibited an enhanced preference for glucose solutions. Furthermore, the elevated preferences could be accounted for not by increases in absolute NaCl or glucose intake, but by decreases in water intake. The adrenal gland weights were significantly lower for males in the highest salt group. There is an early period in development during which fluid regulation may be influenced permanently by dietary sodium levels.

Animals↗