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Biomedical subjects

T W Uhde

Publications and source records attributed to T W Uhde.

At least 181 records · Page 10Linked to original sources
PubMed1982

Biological peripheral correlates of anxiety.

Anxiety is often accompanied by physiological and neuroendocrine changes in both psychiatric patients and normal volunteers. Among these correlates the increase of plasma cortisol and catecholamine concentrations have also been documented in stress and hyperarousal states and, therefore, their specificity in anxiety remains to be studied. Recent studies have shown that biological correlates of central noradrenergic system activity, measured in the CSF or blood are increased in relation to anxiety symptoms. Redmond (1979) has proposed a model for the study of anxiety based upon the function of the noradrenergic locus coeruleus (LC) which may provide a neuroanatomical basis for these changes. In the animal, electrical and pharmacological activation of the LC causes increased NE turnover and fear-associated behaviors, whereas lesions and pharmacologic inhibition of the LC produce decreased fear-associated behavior and NE turnover. Drugs with known antianxiety efficacy in man decrease the LC firing in animals. In contrast, clonidine, an alpha-2 adrenergic agonist which inhibits LC activity in animals may have antianxiety effects in patients with depression, anxiety, and opiate abstinence syndrome.

Anxiety Disorders↗
PubMed1981

Effect of carbamazepine on CSF opioid activity; relationship to antidepressant response.

Carbamazepine, a drug useful in the treatment of trigeminal neuralgia and temporal lobe epilepsy, has recently been found to have positive psychotropic effects in patients with manic and depressive illness. The possible effect of carbamazepine on opioid activity in cerebrospinal fluid (CSF) were assessed in patients with affective disorders using a radioreceptor assay that detects total opioid binding activity. No effect of carbamazepine was noted on CSF total opioid activity, although conclusions about its possible effects on discrete opiate systems must await other methodologies. Initial medication-free levels of opioid activity were positively correlated with the degree of antidepressant response to carbamazepine.

Carbamazepine↗
PubMed1980

Clonidine suppresses the opioid abstinence syndrome without clonidine-withdrawal symptoms: a blind inpatient study.

Nine hospitalized opioid-addicted patients were blindly given clonidine within 36 hours of the abrupt and blind discontinuation of methadone. All nine patients were successfully withdrawn from methadone and were asymptomatic upon discharge. Clonidine-treated patients had significantly fewer symptoms than a comparable group of opioid addicts abruptly withdrawn from methadone. No exacerbation of symptomatology developed after the cessation of clonidine. The clinical implications of clonidine's suppression of opioid withdrawal and the alpha-2 adrenergic mediation of the abstinence syndrome are discussed.

Adult↗
PubMedDate not supplied

Dose-response effects of intravenous caffeine in normal volunteers.

The administration of caffeine has been developed as a chemical model for the study of anxiety. However, previous researchers investigating caffeine-induced anxiety states in humans have administered oral caffeine. In this dose-response study, we investigated the effects of blindly administered intravenous caffeine (3, 5, and 7 mg/kg) versus placebo in normal control subjects. We report the first series of subjects experiencing olfactory hallucinations (10 of 10 subjects, 24 of 30 infusions) immediately following intravenous caffeine infusion. In addition, consistent with our previous work with oral caffeine, we found dose-related increases in ratings of anxiety and blood levels of cortisol and lactate. One subject experienced a DSM-III-R panic attack. Further questioning revealed that his mother suffers panic attacks. Our findings of olfactory hallucinations are discussed within the context of localized limbic system dysfunction, noting the phenomenologic and possible neuroanatomic overlap between panic disorder and complex partial seizures.

Adult↗
PubMedDate not supplied

Peptides and anxiety: a dose-response evaluation of pentagastrin in healthy volunteers.

A large body of data suggest that brain cholecystokinin (CCK) systems are involved in the regulation of anxiety, and numerous studies have demonstrated that CCK-4, a CCKB agonist, reliably induces panic attacks in patients with panic disorder. Recently, pentagastrin, a commercially available CCKB agonist, has been reported to have similar anxiogenic properties. To further explore the utility of pentagastrin as a challenge agent and to determine whether its effects are dose-related, a dose-response study was conducted in ten healthy volunteers. Pentagastrin (0.2 microgram/kg, 0.6 microgram/kg and 1.0 microgram/kg) and inactive placebo were infused over one minute on four separate challenge days in a double-blind fashion. Subjects received pentagastrin while participating in a structured social interaction task. Repeated measures of anxiety, blood pressure, pulse, ACTH, and cortisol were taken at baseline and postinfusion. Pentagastrin administration led to increases in anxiety, pulse, ACTH, cortisol and physical symptoms of panic, in a dose-related manner. Participation in the social interaction task led to increases in measures of anxiety as well as increases in pulse and blood pressure. Few differences were found between the 0.2 microgram/kg dose of pentagastrin and placebo, or between the 0.6 microgram/kg and the 1.0 microgram/kg doses of pentagastrin. These findings support the notion that CCK systems are involved in the regulation of anxiety, and suggest that the 0.6 microgram/kg dose may be optimal for increasing symptoms of anxiety while minimizing unpleasant side effects. The powerful anxiogenic effects of the social interaction task underscore the importance of contextual variables in challenge studies.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Lack of efficacy of the adenosine reuptake inhibitor dipyridamole in the treatment of anxiety disorders.

We administered dipyridamole, an adenosine reuptake inhibitor, to 12 outpatients with DSM-III-R anxiety disorders (2 patients with generalized anxiety disorder, 10 patients with panic disorder). Dipyridamole was administered at a flexible dose in a single-blinded fashion following a placebo washout phase and elimination of placebo responders. The mean duration of active treatment with dipyridamole was 46 days (range 21-88 days); the mean peak dose of dipyridamole was 202 +/- 55 mg/day (range 100-300 mg/day). Symptom ratings were completed at regular intervals by the patient and by a research nurse unaware of the treatment condition. Clinically significant improvement in anxiety symptoms was not demonstrated. The implications of these findings for an adenosinergic dysfunction model of panic disorder are discussed.

Adenosine↗
PubMedDate not supplied

Alpha 2-adrenergic receptor function in patients with unipolar and bipolar affective disorders.

Alpha 2-adrenergic receptor function was measured in platelets from unipolar (UP) depressed, bipolar (BP) depressed, and bipolar euthymic patients and normal control subjects. Only the platelets from UP depressed patients were different from control in having an increased number of alpha 2-receptors, a decreased percent norepinephrine inhibition of prostaglandin E1 (PGE1)-stimulated cyclic AMP (cAMP) production, and a decrease in PGE1 stimulation of cAMP production. Platelets from BP patients, depressed or euthymic, were not significantly different from control subjects. These preliminary data suggest that alpha 2-adrenergic receptor function and PGE1 stimulation of cAMP production are diminished in UP patients.

Bipolar Disorder↗
PubMedDate not supplied

Cerebral ventricular size in panic disorder.

Computed axial brain tomography was studied in 25 patients with panic disorder. Patients had normal ventricular-brain ratio (VBR) compared to published norms. There was a significant association between VBR and duration of benzodiazepine use.

Adult↗
PubMedDate not supplied

Life events obtained via interview: the effect of time of recall on data obtained in controls and patients with panic disorder.

Because previous studies have documented the distorting effect of time of recall on the reporting of life events over a one-year period of time, the relation between various life event measures and time of recall over time periods greater than one year was examined in 44 patients with panic disorder and 44 control subjects. For both groups, time of recall was unrelated to any of nine life event measures. The implications of these findings for life event studies requiring retrospection greater than one year are discussed.

Adult↗
PubMedDate not supplied

The relationship between plasma MHPG and NE: employing regression models in estimating centrally derived MHPG and peripheral NE turnover rate in panic disorder.

Studies investigating the role of the noradrenergic system in the pathophysiology of anxiety have focused on measuring plasma 3-methoxy-4-hydroxyphenylethyleneglycol (MHPG) levels. Fewer studies have examined norepinephrine levels. Basal plasma norepinephrine and free MHPG levels were simultaneously measured in 33 normal controls and 20 panic disorder (PD) patients. Norepinephrine levels were similar in patients and controls, but MHPG levels were significantly lower in patients (13.34 +/- 3.22 vs 18.37 +/- 4.49 pmol ml-1, p < 0.0001). Norepinephrine correlated significantly with plasma MHPG levels in controls (r = 0.538, p < 0.0001) and patients (r = 0.645, p < 0.002). Patients had a trend toward a lower y-intercept than controls, suggesting a lower contribution by the CNS to MHPG pool plasma levels (9.18 vs 12.51, p < 0.08). Norepinephrine turnover rate was similar in patients and controls. We propose that the dysregulation in the noradrenergic system in PD may be akin to animal studies of acute-on-top-of-chronic stress paradigms, whereby chronic stress results in normal or decreased basal NE turnover and sensitized responses to recurrent stresses.

Adult↗