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Biomedical subjects

M A Raskind

Publications and source records attributed to M A Raskind.

At least 19 recordsLinked to original sources
PubMed1992

Testosterone reverses a senescent decline in extrahypothalamic vasopressin mRNA.

The biosynthetic activity of extra-hypothalamic vasopressin (VP) neurons in the bed nucleus of the stria terminalis (BNST) is regulated by gonadal steroids. These neurons have also been implicated in a number of behaviors that are impaired in aging. We previously reported that VP mRNA labelling in the BNST is decreased in senescent rats. We hypothesized that the age-related decrease in VP mRNA labelling is due to the decline in circulating testosterone (T) levels in aged animals. T or saline was administered peripherally for 1 month in physiologic or superphysiologic doses to 3 month old or 24 month old Fischer 344 male rats. In situ hybridization and quantitative autoradiography for VP mRNA in the BNST were performed using a 48-base 35S-labelled oligonucleotide probe. Administration of T completely reversed the decline in VP mRNA labelling in the aged animals. Superphysiologic T further increased VP gene expression in both age groups. These data are consistent with a previous report of T-induced increase in VP immunoreactive fiber density in other extrahypothalamic regions of the brain in aged rats. This study offers further evidence that alterations in the hormonal milieu may play an important role in modulating neuronal biosynthetic activity in senescence.

Aging↗
PubMed1992

Neurohypophyseal and pituitary-adrenocortical responses to the alpha 1 agonist methoxamine in humans.

To test the hypothesis that the release of neurohypophyseal peptides into plasma in humans is stimulated by a central nervous system (CNS) alpha 1 adrenergic mechanism, we measured the responses of arginine vasopressin (AVP) and oxytocin (OT) to intravenous methoxamine, an alpha 1 agonist which enters the CNS following peripheral administration. The potential confound of baroreceptor inhibition of AVP release by the pressor effect of methoxamine was addressed by measuring the plasma AVP response to infusion of norepinephrine (NE), an alpha 1 agonist which does not enter the CNS and which produced an equivalent pressor effect. We also assessed the pituitary adrenocortical system responses to methoxamine and norepinephrine infusions by measuring plasma ACTH and cortisol concentrations. In addition, plasma NE and epinephrine were measured. Methoxamine, but not NE, increased plasma AVP compared to placebo infusion. Neither methoxamine nor NE affected plasma OT. The AVP elevation was delayed until more than 60 min after the methoxamine infusion began and the peak AVP level occurred 30 min after cessation of the infusion. In contrast, ACTH and cortisol increased early during methoxamine infusion and ACTH returned to baseline promptly after the infusion ceased. Although it is possible that the AVP response to methoxamine reflected stimulation of AVP release at a CNS level, it is also possible that the AVP increase represented a rebound response to withdrawal of methoxamine.

Adrenal Cortex↗
PubMed1992

Familial presenile dementia with psychosis associated with cortical neurofibrillary tangles and degeneration of the amygdala.

We report a family in which 13 members in three generations had the presenile (age 42 to 66 years) onset of dementia with an autosomal dominant pattern of inheritance. An early symptom in eight individuals was prominent antisocial psychotic or belligerent behavior, often leading to the initial clinical diagnosis of paranoid schizophrenia. Duration of illness was longer than is usual in Alzheimer's disease (AD), ranging from 14 to 26 years in six members. Three affected siblings and a cousin have come to autopsy, and all had neurofibrillary tangles without senile plaques in several regions of the neocortex, amygdala, and parahippocampal gyrus. The hippocampus was free of both neurofibrillary tangles and senile plaques in all four, but in three there was neuronal loss with gliosis in the CA1 region of Ammon's horn bilaterally. There also was neuronal loss and neurofibrillary tangles in the nucleus basalis. The neurofibrillary tangles were tau-2 and Alz-50 positive and were composed of paired helical filaments ultrastructurally. The disease in this kindred appears to be a unique hereditary disorder that is distinct from familial AD.

Alzheimer Disease↗
PubMed1992

Depression in the elderly.

Depression is one of the most common behavioral disorders of later life. Although recognition of depression can be difficult and the management of depression in elderly patients is complex, effective treatment can dramatically improve their quality of life. This brief review presents some of the problems inherent in the diagnostic process, reviews the epidemiology of depression in later life, and outlines treatment approaches once the diagnosis of depression has been established.

Aged↗
PubMed1990

Myoclonus, seizures, and paratonia in Alzheimer disease.

Twenty-eight patients with the clinical diagnosis of probable Alzheimer disease (AD) were followed longitudinally until death. The presence of myoclonus, seizures, and paratonia was monitored as part of this process. At autopsy, 22 of the patients met pathologic criteria for AD and 6 had other degenerative neurologic diseases. Myoclonus was present in 55% of the AD patients and none of the non-AD patients. Seizures were present in 64% of the AD patients, and only 17% of the non-AD patients. Paratonia was found frequently in all patient groups. In most patients, symptoms developed late in the course of their illness. The incidence of myoclonus, seizures, and paratonia in our patients was higher than in most previous studies. The reasons for this finding are discussed.

Adult↗
PubMed1990

Localization of 3H-prazosin binding sites in the supraoptic and paraventricular nuclei of the human hypothalamus.

Using 3H-prazosin, we have examined the distribution of alpha 1-adrenergic receptors in the supraoptic and paraventricular nuclei of the human hypothalamus. Our studies show that binding sites for 3H-prazosin in human hypothalamus possess pharmacological characteristics similar to those of rat brain. Autoradiographic studies revealed discrete localization of 3H-prazosin to the paraventricular and supraoptic nuclei.

Adult↗
PubMed1990

Neuropathological findings in patients with clinical diagnoses of probable Alzheimer's disease.

To assess prospectively the accuracy of standard antemortem clinical diagnostic criteria for Alzheimer's disease, post-mortem examinations were performed on 25 patients who had met DSM-III criteria for primary degenerative dementia and National Institute of Neurological and Communicative Disorders and Stroke criteria for probable Alzheimer's disease. Seventeen patients (68%) met neuropathological criteria for Alzheimer's disease. Two presenile-onset patients had diffuse neocortical senile plaques of insufficient number for definite Alzheimer's disease. Six patients had non-Alzheimer's disease diagnoses. Five of these six had presenile-onset dementia. These results suggest caution in the antemortem diagnosis of Alzheimer's disease in presenile-onset dementia.

Aged↗
PubMed1990

Differential effects of aging on neuroendocrine responses to physostigmine in normal men.

We assessed the effects of age on cholinergic regulation of the hypothalamic-pituitary-adrenal axis and other neuroendocrine systems by measuring the plasma cortisol and beta-endorphin responses to an infusion of the centrally active cholinesterase inhibitor physostigmine (0.0125 mg/kg) in 12 healthy older men (68 +/- 1.7 yr) and 9 healthy young men (25 +/- 1.4 yr). We also measured the responses to physostigmine of plasma GH, arginine vasopressin, epinephrine, and norepinephrine (NE). As estimated by comparing calculated areas under the curve, older subjects had greater cortisol (P = 0.02) and beta-endorphin (P less than 0.01) secretory responses, but a reduced GH (P less than 0.01) secretory response. The arginine vasopressin response did not differ between groups. By analysis of variance, older subjects also had a greater epinephrine response (P = 0.01). Older subjects had higher basal NE concentrations (P less than 0.05), but NE responses to physostigmine did not differ between groups. These findings suggest age-related enhancement of the cholinergic stimulatory regulation of the hypothalamic-pituitary-adrenal axis and adrenal medulla. They also confirm previous reports of reduced GH secretory response with aging in normal men.

Adult↗
PubMed1990

Severe withdrawal symptoms after discontinuation of alprazolam in eight patients with combat-induced posttraumatic stress disorder.

Eight patients with combat-induced chronic posttraumatic stress disorder (PTSD) receiving long-term alprazolam therapy for anxiety or depression (maximum dose of 2-9 mg/day for 1-5 years) had alprazolam therapy withdrawn. Most of the patients underwent gradual medication withdrawal. All patients had a prior history of alcohol abuse or benzodiazepine dependence. During withdrawal, all patients had severe reactions including anxiety, sleep disturbance, rage reactions, hyperalertness, increased nightmares, and intrusive thoughts; and 6 of the 8 patients had homicidal ideation. As a result of this report, the authors suggest that the potential for severe withdrawal reactions, even with gradual tapering, should be considered before prescribing alprazolam therapy for this group of patients.

Adult↗
PubMed1989

Neuroendocrine responses to physostigmine in Alzheimer's disease.

To assess central nervous system cholinergic neuroendocrine regulation in Alzheimer's disease (AD), we measured plasma arginine vasopressin, beta-endorphin, and epinephrine responses to a cholinergic challenge elicited by intravenous administration of the acetylcholinesterase inhibitor physostigmine (0.0125 mg/kg) in male patients with AD (n = 12) and compared their responses with those of age-matched normal control subjects (n = 12). Physostigmine promptly increased plasma arginine vasopressin (tenfold), beta-endorphin (twofold to threefold) and epinephrine (threefold) levels in elderly control subjects. In contrast, patients with AD showed attenuated responses to physostigmine. When controls and patients with AD who experienced nausea (n = 2 and n = 6, respectively) were excluded, the arginine vasopressin, beta-endorphin, and epinephrine responses of patients with AD were significantly less than those of control subjects. These data suggest that the central nervous system cholinergic deterioration of AD results in decreased responsiveness of neuroendocrine systems that are regulated by central cholinergic mechanisms.

Aged↗
PubMed1989

Pressor, norepinephrine, and pituitary responses to two TRH doses in Alzheimer's disease and normal older men.

Changes in blood pressure (BP), plasma norepinephrine (NE), serum prolactin (PRL), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) associated with infusions of two thyrotropin-releasing hormone (TRH) doses (0.1 mg, 0.5 mg) were examined in 10 men with early-onset Alzheimer's disease (AD) and nine normal matched controls. During the first 5 min after TRH infusion, significant increases from baseline in systolic BP (p less than 0.001), diastolic BP (p less than 0.001), and plasma NE (p less than 0.006) occurred in the study subjects. The magnitude of the BP and NE responses did not differ significantly as a function of TRH dose (p greater than 0.3). Diastolic pressor responses to TRH were substantially blunted in AD subjects relative to controls, after both the 0.1-mg (p less than 0.003) and 0.5-mg (p less than 0.02) doses. There were trends toward attenuated responses in the AD subjects for systolic BP (p less than 0.09) and plasma NE (p less than 0.07). Significant increments in serum PRL, LH, and FSH (all p less than 0.001) also occurred after TRH, but the magnitude of the hormone responses did not differ significantly between the AD and the normal subjects (p greater than 0.18). These results suggest the possibility that TRH-evoked activation of the sympathetic nervous system (SNS), as reflected by pressor and plasma NE responses, may be attenuated in men with early-onset AD.

Aged↗
PubMed1989

Impaired sympathetic nervous system response to cognitive effort in early Alzheimer's disease.

Sympathetic nervous system responses to a cognitive challenge and a physiologic stimulus (upright posture) were compared in 10 patients with early Alzheimer's Disease and a group of healthy older adults. Plasma catecholamine and cardiovascular responses to upright posture were similar in the two groups. However, sympathetic activation during mental effort was impaired in the patient group; this difference did not appear to be attributable to motivational factors. Alzheimer's Disease is associated with a defect in sympathetic nervous system function that is specifically linked to cognitive effort and appears early in the course of the disease.

Aged↗
PubMed1989

Functional status and cognitive impairment in Alzheimer's patients with and without depression.

Cognitive impairment and depression each compromise functional status in the elderly, but it is not known whether their coexistence is associated with additive functional impairment. The effect of the presence or absence of a diagnosis of major depression on functional status was examined in a group of 50 community-residing patients with dementia of the Alzheimer's type (DAT). Patients were diagnosed as depressed (N = 20) or not (N = 30) according to DSM-III criteria. Cognitive status was assessed with the Mini-Mental State Exam (MMSE), and functional status was assessed by family report of Instrumental Activities of Daily Living (IADLs). Consistent with previous reports, patients with a depression diagnosis were less cognitively impaired than their nondepressed counterparts. When cognitive status was controlled for, depression diagnosis was found to have a main effect on functional impairment. Although the direction of effects between depression and functional limitations was not determined here, these results suggest that alleviating depression may decrease functional limitations in DAT patients.

Activities of Daily Living↗
PubMed1989

Yohimbine increases cerebrospinal fluid and plasma norepinephrine but not arginine vasopressin in humans.

Previous studies have demonstrated alpha 2-inhibitory regulation of central nervous system (CNS) noradrenergic and arginine vasopressinergic systems. We tested the hypothesis that alpha 2-inhibition of CNS noradrenergic and vasopressinergic systems is tonic in nature by measuring the response of cerebrospinal fluid (CSF) norepinephrine (NE) and arginine vasopressin (AVP) to the alpha 2-antagonist yohimbine in 7 young normal male human subjects. We also evaluated the tonic nature of alpha 2-inhibition of the sympathetic nervous system (SNS) and of AVP release into plasma by measuring the response of plasma NE and plasma AVP to yohimbine. CSF NE was significantly higher following yohimbine as compared to placebo. In contrast CSF AVP did not differ between yohimbine and placebo conditions. Similarly, plasma NE was significantly higher following yohimbine as compared to placebo, while plasma AVP was unchanged. These results support a tonic alpha 2-inhibitory regulatory mechanism for both CNS noradrenergic systems and sympathetic outflow. Such tonic alpha 2-inhibition could not be demonstrated for regulation of AVP levels in CSF or plasma in humans.

Adult↗
PubMed1988

TSH responses to two TRH doses in men with Alzheimer's disease.

TSH responses to two TRH doses (0.1 mg, 0.5 mg) were determined in 10 men with Alzheimer's disease (AD) and in nine healthy matched controls. Maximum change in TSH (delta TSH) and TSH responses over time, analyzed independently for each TRH dose, did not reveal any significant differences between the AD and the normal subjects. Blunted delta TSH responses were an uncommon finding in both groups. Analyses examining the influence of TRH dose on TSH responses revealed significant group differences. In normal subjects, delta TSH responses following the 0.5 mg TRH dose were significantly greater than delta TSH responses following the 0.1 mg TRH dose (p less than 0.01). However, in the AD group, the effects of TRH dose on delta TSH were largely attributable to the exaggerated and outlying TSH responses of one AD subject. For the remaining nine AD subjects, delta TSH responses following the 0.1 mg and 0.5 mg TRH doses were not significantly different (p greater than 0.1). In the analysis of TSH responses over time, the difference between the 0.1 mg and the 0.5 mg TRH-induced TSH responses was significantly smaller in the AD group at several timepoints after infusion compared to the normal subjects.

Aged↗