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Biomedical subjects

L H Price

Publications and source records attributed to L H Price.

At least 73 records · Page 4Linked to original sources
PubMed1995

Psychiatric status after human fetal mesencephalic tissue transplantation in Parkinson's disease.

This report describes the prospective and systematic psychiatric assessment of nine patients who received transplantation of human fetal mesencephalic tissue into the caudate nucleus for treatment of Parkinson's disease. Unlike adrenal medullary transplantation, which often causes psychosis or delirium, this procedure appeared to have few perioperative sequelae. On longer-term follow-up, there was some statistical evidence of deterioration in psychiatric status, as manifested primarily in depressive and nonspecific emotional and behavioral symptoms. This group effect was partly attributable to the occurrence of discrete episodes of illness (major depression and panic disorder with agoraphobia) in some patients, but it was unclear whether such episodes occurred more often than would ordinarily be expected in Parkinson's disease. Differences in the neurobiological effects of fetal mesencephalic and adrenal medullary grafts may account for differences in the psychiatric sequelae of patients receiving these procedures.

Adult↗
PubMed1995

m-Chlorophenylpiperazine in patients with obsessive-compulsive disorder: absence of symptom exacerbation.

Oral administration of the serotonin mixed agonist-antagonist meta-chlorophenylpiperazine (mCPP) at 0.5 mg/kg has been reported to exacerbate symptoms of obsessive-compulsive disorder (OCD). In an attempt to replicate these findings, double-blind behavioral and biochemical measures were obtained in 12 drug-free patients (9 men, 3 women) with OCD who received either oral mCPP (0.5 mg/kg), intravenous (IV) mCPP (0.1 mg/kg over 20 min), or placebo in random order on 3 separate test days. Neither oral nor IV mCPP had significant effects on the severity of OCD symptoms. The magnitude of the mCPP-induced plasma prolactin response and plasma mCPP levels were similar to those values obtained in other published studies in which mCPP exacerbated OCD symptoms. In contrast, both oral and IV mCPP were associated with significant increases in ratings of anxiety. These findings suggest that mCPP, whether administered by an oral or intravenous route (as a slow infusion), may not be a reliable probe for investigating obsessive-compulsive symptoms. It is possible, however, that more reproducible behavioral findings might be obtained by identifying susceptible subgroups of OCD or by including a behavioral exposure condition.

Administration, Oral↗
PubMed1995

Effects of tryptophan depletion on responses to yohimbine in healthy human subjects.

There is considerable evidence that both the norepinephrine (NE) and serotonin (5-HT) systems are involved in the regulation of human anxiety and fear responses. To assess the modulating effects of central 5-HT levels on NE function, 11 healthy human subjects were studied with placebo-controlled challenge tests involving tryptophan depletion followed by administration of the alpha-2-adrenergic antagonist yohimbine 0.4 mg/kg IV. Five of the 11 subjects reported a marked increase in feelings of nervousness (> or = 25 mm on a 100 mm analog scale) following the combination test, while 1/11 had this response to yohimbine alone. No subjects had an increase in nervousness during other control tests. The increase in nervousness after the tryptophan depletion-yohimbine test was statistically significant for the whole group, but there were no other unique changes in behavioral, physiologic or biochemical (MHPG, cortisol) variables with this test. These data are discussed in terms of possible functional interactions between the 5-HT and NE neurotransmitter systems.

Adrenergic alpha-Antagonists↗
PubMed1995

Noradrenergic response to acute ethanol administration in healthy subjects: comparison with intravenous yohimbine.

The effects of oral administration of ethanol [1.1 ml/kg 95% ethanol administered as a 20% (by volume) solution] and intravenous administration of the alpha 2 adrenergic receptor antagonist yohimbine hydrochloride (0.4 mg/kg), alone and in combination, were compared using a double-blind, placebo-controlled design. Twelve healthy subjects completed 4 test days during which drug effects on subjective measures of intoxication and anxiety, plasma levels of the norepinephrine (NE) metabolite 3-methoxy-4-hydroxyphenylethylene glycol (MHPG) and cortisol, and cardiovascular indices were assessed. Acutely administered oral ethanol significantly increased the subjective measures of intoxication and anxiety, plasma MHPG, and sitting systolic blood pressure compared with placebo. Intravenous yohimbine significantly increased subjective measures of intoxication and anxiety, plasma MHPG and cortisol, and blood pressure relative to placebo. The ethanol-induced increase in plasma MHPG was significantly greater than that following yohimbine, whereas yohimbine resulted in significantly greater increases in anxiety, plasma cortisol, and blood pressure measurements than ethanol. The combined administration of ethanol and yohimbine had a clear additive effect of increasing the severity of acute intoxication compared with ethanol or yohimbine alone, and resulted in a significantly greater plasma MHPG response compared with either drug given alone. Although the pharmacokinetic effects of ethanol administration on NE metabolism must be considered, these findings suggest that the intoxicating and anxiogenic effects of acute ethanol administration may be associated with increased NE turnover, as measured by plasma MHPG, in healthy human subjects. In addition, these results indicate that ethanol and yohimbine may act additively to increase ethanol intoxication and that they may increase NE turnover through different physiological mechanisms.

Adult↗
PubMed1995

Serotonergic mechanisms of cocaine effects in humans.

The objective of this study was to investigate the role of serotonin (5-HT) in mediating the effects of cocaine in humans. To accomplish this, 12 subjects each participated in two randomized, double-blind test sessions separated by 1 week. In one session, subjects underwent acute depletion of the 5-HT amino acid precursor tryptophan (TRP), followed by a test dose of intranasal cocaine. In the other session, the cocaine test dose was preceded by sham depletion. Subject ratings of cocaine "high" were significantly lower following active TRP depletion than after the sham procedure. Subjects also showed an earlier but less sustained rise in self-rated nervousness during active TRP depletion. These findings are consistent with the hypothesis that 5-HT may be involved in mediating the euphorigenic and modulating the anxiogenic effects of cocaine in humans, either directly or through actions on other (e.g., dopaminergic) systems.

Adult↗
PubMed1995

Euphorigenic doses of cocaine reduce [123I]beta-CIT SPECT measures of dopamine transporter availability in human cocaine addicts.

The in vivo potency of euphorigenic doses of intravenous cocaine for displacing [123I]beta-CIT ([123I]2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane) binding to striatal dopamine transporters (DAT) was assessed in human cocaine addicts using single photon emission computed tomography (SPECT). Cocaine-dependent subjects (n = 6) were injected with [123I]beta-CIT and imaged 24 h later under equilibrium conditions. Sequential cocaine infusions (0.28 +/- 0.03 and 0.56 +/- 0.07 mg/kg) produced significant (P < 0.0005) reductions in the specific to non-specific equilibrium partition coefficient, V3" (6 +/- 6 and 17 +/- 3%), a measure proportional to DAT binding potential. Regression analysis of the logit transformed data enabled reliable determination of the Hill coefficient (0.51) and 50% displacement (ED50) dose of cocaine (2.8 mg/kg). These preliminary data suggest that cocaine produces behavioral effects in humans at measurable levels of DAT occupancy.

Carrier Proteins↗
PubMed1995

Lack of efficacy of clozapine monotherapy in refractory obsessive-compulsive disorder.

OBJECTIVE: The authors assessed the efficacy of clozapine monotherapy for adults with treatment-resistant obsessive-compulsive disorder. METHOD: Twelve adults with refractory obsessive-compulsive disorder participated in a 10-week, open-label, systematic trial of clozapine. They were assessed with the Yale-Brown Obsessive Compulsive Scale, the Hamilton Depression Rating Scale, and the global improvement item of the Clinical Global Impression (CGI) scale. RESULTS: None of the 10 patients who completed the trial was a responder. No significant change was observed in obsessive-compulsive or depressive symptoms or in scores on the CGI global improvement item. CONCLUSIONS: These findings suggest that clozapine monotherapy is not effective for most adult patients with treatment-resistant obsessive-compulsive disorder.

Adult↗
PubMed1995

Family accommodation in obsessive-compulsive disorder.

OBJECTIVE: Family accommodation of patients with obsessive-compulsive disorder, i.e., participation in symptoms and modification of personal and family routines, was assessed in relation to family stress, functioning, and attitudes toward the patient. METHOD: Primary caretakers for 34 patients with obsessive-compulsive disorder were interviewed to assess the nature and frequency of accommodating behaviors. The caretakers also completed several measures of family functioning. RESULTS: Of the 34 spouses or parents, 30 (88.2%) reported accommodating the patient. Family accommodation correlated with poor family functioning, rejecting attitudes toward the patient, and several types of family stress. CONCLUSIONS: Family accommodation of patients with obsessive-compulsive disorder was associated with global family dysfunction and stress. This study suggests that families' efforts to accommodate patients may be intended to reduce patient anxiety or anger directed at relatives.

Adult↗
PubMed1995

A case-controlled study of repetitive thoughts and behavior in adults with autistic disorder and obsessive-compulsive disorder.

OBJECTIVE: The purpose of this study was to investigate the types of repetitive thoughts and behavior demonstrated by adults with autistic disorder and compare them with those of age- and sex-matched adults with obsessive-compulsive disorder. METHOD: Fifty consecutive patients admitted to the Yale Adult Pervasive Developmental Disorders (Autism) Clinic with a primary diagnosis of autistic disorder (DSM-III-R and DSM-IV) completed the symptom checklist of the Yale-Brown Obsessive Compulsive Scale. Types of current obsessions and compulsions were evaluated. The comparison group consisted of 50 age- and sex-matched adults with obsessive-compulsive disorder (without tics) (DSM-III-R and DSM-IV). RESULTS: Direct discriminant function analysis showed that the patients with autistic disorder could be distinguished from those with obsessive-compulsive disorder on the basis of the types of current repetitive thoughts and behavior that they demonstrated. Compared to the obsessive-compulsive group, the autistic patients were significantly less likely to experience thoughts with aggressive, contamination, sexual, religious, symmetry, and somatic content. Repetitive ordering; hoarding; telling or asking (trend); touching, tapping, or rubbing; and self-damaging or self-mutilating behavior occurred significantly more frequently in the autistic patients, whereas cleaning, checking, and counting behavior was less common in the autistic group than in the patients with obsessive-compulsive disorder. In addition, a specific subset of seven obsessive-compulsive variables from the Yale-Brown Obsessive Compulsive Scale symptom checklist was identified that reliably predicted membership in the autistic group. CONCLUSIONS: These results suggest that the repetitive thoughts and behavior characteristics of autism differ significantly from the obsessive-compulsive symptoms displayed by patients with obsessive-compulsive disorder. Future studies are warranted to assess the treatment response and neurobiological underpinnings of repetitive thoughts and behavior in patients with autism and obsessive-compulsive disorder.

Adolescent↗
PubMed1995

[123I]beta-CIT SPECT imaging of striatal dopamine transporter binding in Tourette's disorder.

OBJECTIVE: The authors examined whether subjects with Tourette's disorder have greater than normal striatal dopamine transporter densities, as suggested by previous post-mortem findings. METHOD: Single photon emission computed tomography (SPECT) and [123I]2 beta-carbomethoxy-3 beta-(4-iodophenyl)tropane ([123I]beta-CIT) were used to assess dopamine transporter levels in five adult patients with Tourette's disorder and five age- and gender-matched healthy comparison subjects. RESULTS: Striatal [123I]beta-CIT binding was a mean of 37% (range = 6%-79%) higher in the subjects with Tourette's disorder than in the comparison subjects, and each Tourette's disorder patient had a higher level than his or her paired comparison subject. CONCLUSIONS: These findings corroborate post-mortem results and support the hypothesis of a dysregulation in presynaptic dopamine function in Tourette's disorder.

Adult↗
PubMed1995

Opiate dependence and withdrawal: preliminary assessment using single photon emission computerized tomography (SPECT).

Naloxone (0.8 mg, s.c.) effects on opiate withdrawal signs and symptoms and regional brain function were assessed in 10 methadone-maintained patients and 10 healthy subjects in a double-blind, placebo-controlled study. Regional brain function was assessed using single photon emission computerized tomography (SPECT) by evaluating the uptake of [99mTc]d,l-hexamethylpropyleneamine oxime (HMPAO) in the brain, a process related to regional cerebral perfusion. Comparisons of patients and healthy subjects after saline infusion suggested that chronic opiate dependence was associated with lower corrected activity ratios (regional count density/whole brain count density) in frontal and parietal cortices and greater activity ratios in the thalamus. Opiate-dependent patients, but not healthy subjects, developed opiate withdrawal signs and symptoms after naloxone administration. Following naloxone administration, patients undergoing opiate withdrawal exhibited lower whole brain count density than healthy subjects. They also had lower activity ratios in frontal and parietal cortices and increased thalamic activity ratios relative to healthy subjects receiving naloxone. Naloxone administration in healthy subjects, but not opiate withdrawal in patients, was associated with decreased right parietal cortex and increased right temporal cortex and left basal ganglia activity ratios. Relative to naloxone effects in healthy subjects, opiate withdrawal was associated with decreased whole brain count density and a reduced right temporal cortex activity ratio. This preliminary study reports an initial evaluation of HMPAO-SPECT imaging for assessing regional alterations in brain function during opiate dependence and withdrawal. While group differences were reported, the small magnitude of regional alterations in patients undergoing opiate withdrawal raised concern that HMPAO-SPECT methods employed were inadequate for assessing human regional brain function during phases of opiate addiction. Other emerging functional brain imaging technologies should be evaluated relative to improved HMPAO-SPECT methods for this purpose.

Adult↗
PubMed1995

Risperidone addition in fluvoxamine-refractory obsessive-compulsive disorder: three cases.

BACKGROUND: Forty percent to 60% of patients with obsessive-compulsive disorder (OCD) remain unimproved after adequate treatment with serotonin uptake inhibitors (SUIs). The addition of low-dose haloperidol and pimozide to ongoing SUI treatment has been shown to be effective in up to 65% of SUI-refractory OCD patients, particularly in those with comorbid chronic tic disorder. Because OCD patients typically require prolonged pharmacotherapy, they are subject to the development of tardive dyskinesia during neuroleptic treatment. Risperidone is a highly potent and selective serotonin2 and dopamine2 receptor antagonist with a side effect profile that appears to be much more tolerable and safer than that of typical neuroleptics. METHOD: We report our experience with three OCD patients who were unimproved after a minimum of 12 weeks of treatment with the potent and selective SUI fluvoxamine, in whom we added risperidone in an open-label manner. RESULTS: All three patients showed significant improvement in their obsessive-compulsive symptoms as measured by the Yale-Brown Obsessive Compulsive Scale (Y-BOCS) after risperidone 1 mg/day was added to ongoing fluvoxamine (250-300 mg/day). Within 4 weeks of adding risperidone, the three patients' Y-BOCS scores had decreased by 65%, 56%, and 43%, respectively. Other than mild or moderate sedation, no side effects were observed. CONCLUSION: These results suggest that risperidone addition to ongoing SUIs may be an effective treatment strategy for refractory OCD.

Adult↗
PubMed1995

Cocaethylene: pharmacology, physiology and behavioral effects in humans.

Comorbid abuse of cocaine and alcohol is a common occurrence. Cocaethylene, the ethyl ester of benzoylecgonine, is an active metabolite formed as a result of simultaneous use of these substances. In humans, the concurrent ingestion of cocaine and alcohol, with resulting cocaethylene formation, has been associated with enhanced subjective euphoria, increased heart rate and increased plasma cocaine concentration. These findings suggest that cocaethylene may play a role in the morbidity and mortality associated with concurrent cocaine/alcohol abuse. This placebo-controlled, double-blinded study examined the behavioral and physiological effects and pharmacokinetics of intranasal cocaethylene administration in humans (n = 8), using cocaine as a comparator. Cocaethylene administration resulted in a euphoria similar to that produced by cocaine, although the effects differed significantly over time. Subjects were unable to distinguish between equimolar doses of cocaine and cocaethylene, although cocaethylene appeared to be eliminated more slowly than cocaine. Cardiovascular effects of cocaethylene and cocaine were similar. These findings are considered in light of the epidemiology and possible consequences of cocaine and alcohol abuse.

Behavior↗