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Biomedical subjects

L H Price

Publications and source records attributed to L H Price.

At least 109 records · Page 6Linked to original sources
PubMed1993

The serotonin hypothesis of obsessive compulsive disorder.

The above studies investigating the responsivity of the 5-HT system to provocation provide some support for the hypothesis drawn from the results of pharmacologic treatment trials and studies of biological markers that dysregulation of the 5-HT system may be involved in the pathogenesis of OC symptoms. While results of several studies document blunting of neuroendocrine responses to 5-HT agonists, only one study suggests a small increase in responsiveness compared to healthy controls. Combined with neurophysiologic data suggesting net increases in 5-HT functioning following treatment with SRIs, these results suggest that the primary deficit in OCD is not one of increased 5-HT responsivity. Exacerbation of OC symptoms sometimes observed during mCPP challenge is not entirely consistent with this hypothesis and additional studies are required to clarify the significance of these findings. However, behavioral hypersensitivity coupled with neuroendocrine hyposensitivity to serotonergic stimulation might characterize the serotonergic dysfunction accompanying OCD. The complexity of the 5-HT system, and the likelihood that behavioral and neuroendocrine responses are mediated by different receptor subtypes makes this hypothesis entirely plausible. The efficacy of SRIs in the treatment of OCD remains the firmest evidence of serotonergic involvement in this condition. Results of challenge studies in OCD also suggest a possible dysregulation in 5-HT function, although the precise nature of this disturbance remains elusive. Neuroendocrine responses to 5-HT agonists generally are consistent with a tendency toward hyposensitivity in OCD. Behavioral results, while more mixed, indicate a hypersensitivity to 5-HT agonists. Further refinement in dependent and independent variables used in challenge studies may clarify remaining questions.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Limited therapeutic effect of addition of buspirone in fluvoxamine-refractory obsessive-compulsive disorder.

The authors found that buspirone added to the treatment of 33 patients with obsessive-compulsive disorder who were refractory to the serotonin reuptake inhibitor fluvoxamine was no better than placebo in reducing obsessive-compulsive, depressive, or anxiety symptoms. This finding suggests that addition of buspirone to ongoing fluvoxamine therapy is not an effective treatment strategy for most patients with obsessive-compulsive disorder.

Adult↗
PubMed1993

Inpatient treatment of patients with severe obsessive-compulsive disorder.

Patients with obsessive-compulsive disorder may experience severely disabling symptoms and require hospitalization. Based on treatment of 77 such patients admitted to a long-term general psychiatric research unit over a seven-year period, the authors present pharmacologic, psychosocial, and behavioral management strategies for treating these patients on general psychiatric units. The treatment guidelines require only modest modifications of standard practice and can be adapted for use on general units without specialized staff training. Some patients with obsessive-compulsive disorder exhibit strong control and dependency needs and disrupt the milieu in characteristic ways. These patients may generate conflict among staff about whether the patients can control obsessive-compulsive behaviors; they may anger other patients because of the large amount of staff attention they demand. Educating staff about obsessive-compulsive patients' control and dependency needs and enlisting the support of fellow patients can improve the milieu.

Adult↗
PubMed1993

Effects of acute tryptophan depletion on nocturnal melatonin secretion in humans.

Measurement of melatonin secretion throughout the night provides an index of net noradrenergic activity mediated by postsynaptic beta-adrenergic receptors in the pineal gland. Reduced melatonin secretion in some patients with depression might be related to reduced net noradrenergic function. However, a dysregulation in serotonin function has also been implicated in the pathophysiology of depression. The essential amino acid tryptophan is the precursor for both serotonin and melatonin production. To determine the effects of serotonin function on nocturnal melatonin secretion, eight healthy volunteers underwent active and sham tryptophan depletion in a randomized, double-blind fashion. Blood samples for melatonin and free and total tryptophan were obtained before and after the depletion. Acute tryptophan depletion decreased free and total plasma tryptophan levels to less than 20% of baseline levels. Melatonin secretion, expressed as area under the curve, was decreased in all eight subjects after tryptophan depletion when compared to sham depletion. These results suggest that reduced plasma tryptophan levels, and presumably brain serotonin concentrations, decrease nocturnal melatonin secretion in humans. Additional studies investigating the relationship between serotonin metabolism and pineal function in humans appear warranted.

Adult↗
PubMed1993

Effects of acute buprenorphine on responses to intranasal cocaine: a pilot study.

Five inpatients dependent on both intravenous cocaine and heroin were detoxified from opiates. They were then given 5 days of double-blind treatment with active or placebo buprenorphine 2 mg/d sublingually, followed by a crossover to the converse for 5 days (buprenorphine or placebo). Intranasal cocaine challenges (2 mg/kg) were performed on Days 3 and 5 of each treatment. Buprenorphine significantly enhanced patients' ratings of cocaine-induced pleasurable effects, and augmented cocaine-induced pulse increases. The buprenorphine enhancement of subjective cocaine effects appeared to be more prominent on Day 3 than on Day 5. This reduction from Day 3 to Day 5 suggests that cocaine may interact differently with buprenorphine as treatment is more prolonged.

Adult↗
PubMed1993

The efficacy of fluvoxamine in obsessive-compulsive disorder: effects of comorbid chronic tic disorder.

This retrospective case-controlled analysis evaluated treatment response to the serotonin reuptake inhibitor fluvoxamine in patients with obsessive-compulsive disorder (OCD), with or without a comorbid chronic tic disorder. Thirty-three fluvoxamine-treated OCD patients with a concurrent chronic tic disorder were compared with 33 age- and sex-matched OCD patients without chronic tics who had received fluvoxamine treatment in the same setting during the same period of time and in a similar manner. Although both groups of patients demonstrated statistically significant reductions in obsessive-compulsive, depressive, and anxiety symptoms with fluvoxamine treatment, the frequency and magnitude of response of obsessive-compulsive symptoms was significantly different between the two groups. A clinically meaningful improvement in obsessive-compulsive symptoms occurred in only 21% of OCD patients with comorbid chronic tics compared with a 52% response rate in OCD patients without chronic tics. Moreover, OCD patients with a concurrent chronic tic disorder showed only a 17% reduction in Yale-Brown Obsessive-Compulsive Scale scores compared with a 32% decrease in the severity of obsessive-compulsive symptoms in those OCD patients without chronic tics. These results suggest that serotonin reuptake inhibitor monotherapy may be less efficacious for improving obsessive-compulsive symptoms in OCD patients with than without tics. Combined with differences in the clinical phenomenology between these two groups, these treatment response data support the hypothesis that OCD patients with a comorbid chronic tic disorder may be a clinically meaningful subtype.

Adult↗
PubMed1993

Paroxetine: a new serotonin reuptake inhibitor for the treatment of depression.

The introduction of the selective serotonin reuptake inhibitors (SSRIs) over the past several years has made a major impact on the treatment of depression and other neuropsychiatric disorders. Agents in this heterogeneous group of compounds are generally better tolerated and less toxic than the tricyclic antidepressants (TCAs), which they have in many respects superseded. This review summarizes available data on paroxetine, the newest SSRI to receive approval for the treatment of depression.

Depressive Disorder↗
PubMed1993

The psychopharmacology of obsessive compulsive disorder. Implications for treatment and pathogenesis.

Recent advances in the pharmacotherapy of obsessive compulsive disorder (OCD) have led to a significant reduction in suffering and a return to productive living for many patients previously considered refractory to treatment. Potent inhibitors of 5-hydroxytryptamine (5-HT) re-uptake clearly have been established as the first-line pharmacotherapy for treatment of OCD. The addition of agents that enhance 5-HT neurotransmission to ongoing treatment in patients whose OCD is refractory to 5-HT re-uptake inhibitors has not yielded impressive results. The addition of dopamine (DA) antagonists to the regimens of treatment-resistant patients appears to be a potentially useful strategy for the specific subgroup of OCD patients with a comorbid chronic tic disorder such as Tourette's syndrome. Pharmacologic studies suggest that both the 5-HT and DA systems may be critical to the treatment and possibly the pathophysiology of OCD.

Behavior Therapy↗
PubMed1993

Biological approaches to treatment-resistant obsessive compulsive disorder.

Biological approaches to the patient with treatment-resistant obsessive compulsive disorder are briefly reviewed. The most commonly employed strategy involves combining a potent serotonin reuptake inhibitor (SRI) (e.g., clomipramine or fluvoxamine) with another medication that may exert effects on the brain serotonin system. Open-label reports regarding the addition of tryptophan, fenfluramine, lithium, or buspirone to ongoing SRI therapy of obsessive compulsive disorder are encouraging. However, the anti-obsessive compulsive efficacy of SRI-lithium and SRI-buspirone combination therapy has not been confirmed in recent controlled trials. Preliminary evidence suggests that addition of neuroleptic may benefit SRI-refractory obsessive compulsive disorder patients who have a comorbid chronic tic disorder. Other biological approaches (e.g., electroconvulsive therapy and psychosurgery) are considered in terms of their narrowly defined roles in the treatment of patients with SRI-resistant obsessive compulsive disorder. Finally, an algorithm is proposed for those patients with obsessive compulsive disorder who fail to respond to an adequate trial with a potent SRI.

Behavior Therapy↗
PubMed1992

Unilateral transplantation of human fetal mesencephalic tissue into the caudate nucleus of patients with Parkinson's disease.

BACKGROUND: Parkinson's disease is characterized by the loss of midbrain dopamine neurons that innervate the caudate and the putamen. Studies in animals suggest that fetal dopaminergic neurons can survive transplantation and restore neurologic function. This report compares the clinical results in four case patients with severe Parkinson's disease who underwent stereotaxic implantation of human fetal ventral mesencephalic tissue in one caudate nucleus with the results in a control group of similar subjects assigned at random to a one-year delay in surgery. METHODS: Each case patient received cryopreserved tissue from one fetal cadaver (gestational age, 7 to 11 weeks). Before implantation, adjacent midbrain tissue underwent microbiologic, biochemical, and viability testing. Cyclosporine was administered for six months postoperatively. RESULTS: The procedure was well tolerated. Three case patients showed bilateral improvement on motor tasks, as assessed on videotape, and were more functional in the activities of daily living, as assessed by themselves and neurologists, during both optimal drug therapy and "drug holiday" periods. One case patient, who died after four months from continued disease progression, had striatonigral degeneration at autopsy. In the patients who received transplants, optimal control was achieved with a lower dose of antiparkinsonian medications, whereas the controls required more medication. Positron-emission tomography with [18F]fluorodopa before and after surgery in one patient revealed a bilateral restoration of caudate dopamine synthesis to the range of normal controls, but continued bilateral deficits in the putamen. CONCLUSIONS: Although the case patients continued to be disabled by their disease, unilateral intracaudate grafts of fetal tissue containing dopamine diminished the symptoms and signs of parkinsonism during 18 months of evaluation.

Activities of Daily Living↗
PubMed1992

Dose-response relationship for oral idazoxan effects in healthy human subjects: comparison with oral yohimbine.

The effects of oral administration of the alpha 2 adrenergic receptor antagonists idazoxan (20 mg, 40 mg, 80 mg) and yohimbine (20 mg) were compared using a placebo-controlled within-subjects design. Healthy subjects completed 5 test days during which medication effects on mood and anxiety states, physiologic indices, plasma cortisol levels, and plasma levels of the norepinephrine metabolite 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) were assessed. Idazoxan dose-dependently increased plasma MHPG, plasma cortisol, systolic and diastolic blood pressure, and Panic Attack Symptom Scale scores in healthy subjects. Overall, yohimbine and idazoxan produced a similar pattern of behavioral and neuroendocrine responses. Since idazoxan possesses relatively greater receptor specificity compared to yohimbine, it may be a more useful alpha 2 antagonist in humans.

Adrenergic alpha-Antagonists↗
PubMed1992

Serotonergic function during lithium augmentation of refractory depression.

Serotonergic mechanisms have been implicated in the pathophysiology of depression and in the neuropharmacology of antidepressant treatment. One measure of central serotonergic function is the prolactin (PRL) response to IV L-tryptophan (L-TRP). We used the L-TRP test to assess the role of serotonin in the mechanism of action of lithium augmentation in refractory major depression. Twenty-six patients with antidepressant-refractory major depression each received three L-TRP tests (after 2 weeks of placebo, after 4 weeks of active primary antidepressant, and after 1 week of lithium augmentation). Primary antidepressant treatment did not increase the PRL response, but lithium augmentation resulted in a statistically significant increase in PRL response as compared to both placebo pretreatment (P less than 0.04) and antidepressant treatment alone (P less than 0.025). This study supports a role for serotonergic mechanisms in the action of lithium augmentation.

Adult↗
PubMed1992

A comparison of trazodone and fluoxetine: implications for a serotonergic mechanism of antidepressant action.

Trazodone is an atypical antidepressant drug that is commonly referred to as a serotonin (5-hydroxytryptamine; 5-HT) uptake inhibitor. However, the most potent pharmacological effect of trazodone appears to be antagonist action at 5-HT2/1C receptors. This is in contrast to fluoxetine, for which inhibition of 5-HT uptake is the most potent pharmacological action. The effects of trazodone and fluoxetine on several antidepressant drug screens are mediated by antagonist action at 5-HT2 receptors and inhibition of 5-HT uptake, respectively. While fluoxetine is an effective agent for the treatment of major depression, obsessive-compulsive disorder (OCD) and panic disorder, trazodone does not appear to be effective in the treatment of OCD and panic disorder. In addition, trazodone and fluoxetine differ in humans with respect to their effects on sleep and weight. Taken together, the preclinical and clinical data suggest that trazodone acts as an antidepressant via antagonist action at 5-HT2/1C receptors, while fluoxetine likely acts as an antidepressant via inhibition of 5-HT uptake.

Animals↗
PubMed1992

Dopaminergic responsivity during cocaine abstinence: a pilot study.

This preliminary study investigated dopamine (DA) function in six hospitalized cocaine-dependent subjects (DSM-III-R) who received 1.5 mg/kg of active cocaine by mouth, t.i.d., for 3 days followed by 9 days of placebo cocaine. During early and late abstinence from cocaine, plasma growth hormone (GH), homovanillic acid (HVA), prolactin, and 3-methoxy-4-hydroxyphenethyleneglycol responses to the placebo-controlled administration of oral L-dopa 250 mg/carbidopa 25 mg (Sinemet) were measured. Sinemet caused significantly greater placebo-corrected increases in GH and HVA during early as compared with late abstinence. Acute abstinence from cocaine may be associated with increased DA responsivity, which normalizes over time.

Adult↗
PubMed1992

Baclofen-assisted detoxification from opiates. A pilot study.

In an open label pilot study, five opiate-dependent patients underwent baclofen-assisted opiate detoxification after abrupt discontinuation of methadone. Patients received baclofen in oral doses up to 80 mg/day, and all patients subjectively reported some reduction in discomfort. However, 3 of 5 (60%) patients could not complete detoxification with baclofen, primarily because of insufficient suppression of vomiting, myalgias, and headache. These patients successfully completed their detoxification with clonidine. These findings suggest that, in the dose range studied, baclofen is of limited use as a primary treatment for opiate dependence, although adjunctive roles for this medication in detoxification should be explored.

Adult↗
PubMed1992

Clomipramine in autism: preliminary evidence of efficacy.

This report provides preliminary evidence for the efficacy of clomipramine in the treatment of young adults with autistic disorder. Four of five outpatients with autistic disorder showed significant improvement in social relatedness, obsessive compulsive symptoms, and aggressive and impulsive behavior with clomipramine treatment. These findings are consistent with previous evidence, suggesting that serotonin neurotransmission may be relevant to the treatment, and possibly the pathophysiology, of some symptoms of autistic disorder.

Adolescent↗