Oral administration of a medium containing both D-aspartate-producing live bacteria and D-aspartate reduces rectal temperature in chicks.

1. The aim of this study was to investigate the effects on the rectal temperature of young chicks of the oral administration of a medium that contained both live bacteria that produce D-aspartate (D-Asp) and D-Asp. 2. In Experiment 1, chicks were subjected to chronic oral administration of either the medium (containing live bacteria and 2.46 µmol D-Asp) or water from 7 to 14 d of age. Plasma-free amino acids as well as mitochondrial biogenic gene expression in the breast muscle were analysed. In Experiment 2, 7-d-old chicks were subjected to acute oral administration of the above medium or of an equimolar amount of D-Asp to examine their effect on changes in rectal temperature. In Experiment 3, after 1 week of chronic oral administration of the medium, 14-d-old chicks were exposed to either high ambient temperature (HT; 40 ± 1°C, 3 h) or control thermoneutral temperature (CT; 30 ± 1°C, 3 h) to monitor the changes in rectal temperature. 3. Chronic, but not acute, oral administration of the medium significantly reduced rectal temperature in chicks, and a chronic effect also appeared under HT conditions. 4. Chronic oral administration of the medium significantly reduced the mRNA abundance of the avian uncoupling protein (avUCP) in the breast muscle, but led to a significant increase in avian adenine nucleotide translocator (avANT) mRNA in the same muscle. 5. (a) These results indicate that the medium can reduce body temperature through the decline in avUCP mRNA expression in the breast muscle that may be involved in reduced mitochondrial proton leaks and heat production. (b) The increase in avANT further suggests a possible enhancement of adenosine triphosphate (ATP) synthesis.

Temporal manipulation of transferrin-receptor-1-dependent iron uptake identifies a sensitive period in mouse hippocampal neurodevelopment.

Iron is a necessary substrate for neuronal function throughout the lifespan, but particularly during development. Early life iron deficiency (ID) in humans (late gestation through 2-3 yr) results in persistent cognitive and behavioral abnormalities despite iron repletion. Animal models of early life ID generated using maternal dietary iron restriction also demonstrate persistent learning and memory deficits, suggesting a critical requirement for iron during hippocampal development. Precise definition of the temporal window for this requirement has been elusive due to anemia and total body and brain ID inherent to previous dietary restriction models. To circumvent these confounds, we developed transgenic mice that express tetracycline transactivator regulated, dominant negative transferrin receptor (DNTfR1) in hippocampal neurons, disrupting TfR1 mediated iron uptake specifically in CA1 pyramidal neurons. Normal iron status was restored by doxycycline administration. We manipulated the duration of ID using this inducible model to examine long-term effects of early ID on Morris water maze learning, CA1 apical dendrite structure, and defining factors of critical periods including parvalbmin (PV) expression, perineuronal nets (PNN), and brain-derived neurotrophic factor (BDNF) expression. Ongoing ID impaired spatial memory and resulted in disorganized apical dendrite structure accompanied by altered PV and PNN expression and reduced BDNF levels. Iron repletion at P21, near the end of hippocampal dendritogenesis, restored spatial memory, dendrite structure, and critical period markers in adult mice. However, mice that remained hippocampally iron deficient until P42 continued to have spatial memory deficits, impaired CA1 apical dendrite structure, and persistent alterations in PV and PNN expression and reduced BDNF despite iron repletion. Together, these findings demonstrate that hippocampal iron availability is necessary between P21 and P42 for development of normal spatial learning and memory, and that these effects may reflect disruption of critical period closure by early life ID.

Selective antagonism of opioid-induced ventilatory depression by an ampakine molecule in humans without loss of opioid analgesia.

Ventilatory depression is a significant risk associated with the use of opioids. We assessed whether opioid-induced ventilatory depression can be selectively antagonized by an ampakine without reduction of analgesia. In 16 healthy men, after a single oral dose of 1,500 mg of the ampakine CX717, a target concentration of 100 ng/ml alfentanil decreased the respiratory frequency by only 2.9 +/- 33.4% as compared with 25.6 +/- 27.9% during placebo coadministration (P < 0.01).Blood oxygenation and the ventilatory response to hypercapnic challenge also showed significantly smaller decreases with CX717 than with placebo. In contrast, CX717 did not affect alfentanil-induced analgesia in either electrical or heat-based experimental models of pain. Both ventilatory depression and analgesia were reversed with 1.6 mg of naloxone. These results support the use of ampakines as selective antidotes in humans to counter opioid-induced ventilatory depression without affecting opioid-mediated analgesia.

Ttc21b is required to restrict sonic hedgehog activity in the developing mouse forebrain.

Organizing centers in the developing brain provide an assortment of instructive patterning cues, including Sonic hedgehog (Shh). Here we characterize the forebrain phenotype caused by loss of Ttc21b, a gene we identified in an ENU mutagenesis screen as a novel ciliary gene required for retrograde intraflagellar transport. The Ttc21b mutant has defects in limb, eye and, most dramatically, brain development. We show that Shh signaling is elevated in the rostral portion of the mutant embryo, including in a domain in or near the zona limitans intrathalamica. We demonstrate here that ciliary defects seen in the Ttc21b mutant extend to the embryonic brain, adding forebrain development to the spectrum of tissues affected by defects in ciliary physiology. We show that development of the Ttc21b brain phenotype is modified by lowering levels of the Shh ligand, supporting our hypothesis that the abnormal patterning is a consequence of elevated Shh signaling. Finally, we evaluate Wnt signaling but do not find evidence that this plays a role in causing the perturbed neurodevelopmental phenotype we describe.

Olanzapine as alternative therapy for patients with haloperidol-induced extrapyramidal symptoms: results of a multicenter, collaborative trial in Latin America.

Conventional antipsychotic agents can induce extrapyramidal symptoms (EPS) that may be alleviated by switching patients to novel agents such as olanzapine. Patients with schizophrenia and related disorders (ICD-10) who were taking haloperidol (N = 94; mean dose = 12.7 mg/day) and had EPS (Simpson-Angus Scale [SAS] > 3) were directly switched to 6 weeks of open-label olanzapine treatment (mean dose = 11.4 mg/day). There were significant mean improvements (p <0.001 for all measurements) from baseline to endpoint on the SAS (-9.69+/-5.33; percentage change, 87.2%), the Barnes Akathisia Scale (-1.00+/-1.19; percentage change, 82.5%), and the Abnormal Involuntary Movement Scale (-1.48+/-2.89; percentage change, 81.1%), and anticholinergic use decreased from 47.9% to 12.8% (mean baseline to endpoint change: -1.52+/-1.91-mg equivalents of benztropine; p < 0.001). Significant mean baseline to endpoint improvements (p < 0.001 for all measurements) were observed on the Positive and Negative Syndrome Scale (PANSS; -25.28+/-18.67; percentage change, 30.3%), the PANSS-extracted Brief Psychiatric Rating Scale (0-6 scale, -13.41+/-10.16; percentage change, 54.4%), and the Clinical Global Impressions Severity scale (-1.16+/-1.19; percentage change, 26.4%). Spontaneously reported treatment- emergent adverse events with a greater than 5% incidence were somnolence (16.0%), increased appetite (14.9%), weight gain (11.7%), headache (8.5%), anxiety (7.4%), dizziness (6.4%), and insomnia (5.3%). Criteria for a successful switch were met by 90.5% of patients. Psychotic symptom exacerbation was experienced by 30.9% of patients at any time during the study and by 11.7% of patients at endpoint. Results suggest that a direct switch to olanzapine is a therapeutic option when patients with haloperidol-induced EPS are unable to tolerate a more gradual switch.

Olanzapine versus haloperidol in schizoaffective disorder, bipolar type.

BACKGROUND: The present analysis was performed on data from a subsample of patients with schizoaffective disorder, bipolar type, who participated in a multicenter, double-blind study comparing olanzapine to haloperidol. METHODS: Patients with schizoaffective disorder bipolar type, characterized as currently manic, mixed, depressed, or euthymic, were assessed weekly for 6 weeks during treatment with either olanzapine or haloperidol. Manic symptoms were measured using the sum of six items of the BPRS, and depressive symptoms were assessed using the Montgomery-Asberg Depression Rating Scale. In addition, cognitive functioning was measured using the sum of seven items from the PANSS. Repeated measures analyses were performed using random coefficients regression of the serial measurement of manic, cognitive, and depressive symptoms. RESULTS: A significant treatment difference was detected overall, indicating that olanzapine was significantly more effective than haloperidol in reducing symptoms of depression and improving patients' cognitive symptoms. The superiority of olanzapine over haloperidol in the reduction of manic symptoms did not reach statistical significance (P=.052). The greatest improvement in both manic and cognitive symptoms was seen in the olanzapine-treated 'currently manic' subgroup, and least improvement in the haloperidol-treated 'euthymic' subgroup. Depressive symptoms were most improved in the olanzapine-treated 'depressed' subgroup, and least improved in the corresponding haloperidol subgroup. CONCLUSIONS: Overall, olanzapine was superior to haloperidol with respect to thymoleptic effects in patients with schizoaffective disorder, bipolar type.

The course of depressive symptoms in predicting relapse in schizophrenia: a double-blind, randomized comparison of olanzapine and risperidone.

BACKGROUND: Depressive symptoms are common during the course of schizophrenia and may carry prognostic relevance. METHODS: From a 28-week prospective, double-blind, randomized study of olanzapine and risperidone, a post hoc evaluation of changes on the Positive and Negative Syndrome Scale (PANSS) depression cluster (PDC) and the subsequent risk of relapse were analyzed by logistic regression. RESULTS: Olanzapine was associated with a significantly higher categorical rate of improvement on the PANSS depression cluster (> or = 7 points) (p < .05). Although the baseline severity of depressive symptoms was not a significant predictor of relapse, the degree of acute (8-week) mood improvement on the PANSS depression cluster (but neither negative or positive symptom changes) was related to the probability of a subsequent psychotic relapse. Acute mood improvement with olanzapine was inversely related to a nonsignificantly lower risk of relapse. However, an opposite and significant relationship was observed among risperidone-treated subjects. Risperidone-treated subjects with a greater degree of acute mood change were both 3.58 times more likely to relapse than their risperidone counterparts who had experienced less mood improvement (p = .008) and 8.55 times more likely than olanzapine-treated subjects who had had similar mood improvements (p = .001). CONCLUSIONS: These data suggest the underlying pharmacologic differences between the two drugs may bestow different rates of longer-term mood stabilization and relapse prevention. In a second series of analyses, worsening on the PANSS depression cluster in the 4 weeks or less preceding a clinical relapse was a significant prodromal predictor of relapse among all subjects. As a whole, subjects with a worsening on the PDC demonstrated a 1.77 times higher risk of a relapse during the subsequent 4 weeks (p = .001). Among this mood-worsening stratum, risperidone-treated patients were 3.51 times more likely to relapse in those next 4 weeks (p = .005) than their olanzapine counterparts. Future comparative drug studies in this area will further contribute to our understanding of the pathophysiology of mood change and its relationship to psychosis, including clinical relapse and how newer agents may differ in their respective delivery of long-term treatment outcomes.

Olanzapine versus haloperidol in the treatment of schizoaffective disorder. Acute and long-term therapy.

BACKGROUND: The effectiveness of antipsychotic monotherapy in schizoaffective disorder is limited, and further constrained by safety concerns. AIMS: We aimed to compare the efficacy, tolerability and safety profile of the new pharmaceutical, olanzapine, with haloperidol. METHOD: Data were assessed from 300 DSM-III-R schizoaffective subjects from a larger double-blind prospective international study. Subjects were randomly allocated to six weeks of olanzapine (5-20 mg) or haloperidol (5-20 mg) treatment; responders were followed for up to one year of double-blind, long-term maintenance therapy. RESULTS: Olanzapine-treated patients achieved a statistically significant greater improvement than haloperidol treated patients on overall measures of efficacy, including clinical response. Significantly fewer olanzapine patients left the study early, and fewer adverse events were observed among those receiving olanzapine. During maintenance, olanzapine-treated patients continued to experience additional improvement, with fewer EPS but more weight gain than those on haloperidol. CONCLUSIONS: Olanzapine demonstrated substantial advantages over the conventional antipsychotic haloperidol in the management of schizoaffective disorder.

Oral olanzapine versus oral haloperidol in the maintenance treatment of schizophrenia and related psychoses.

BACKGROUND: Three studies compared olanzapine and haloperidol given orally in maintenance therapy for schizophrenia and related psychoses. METHOD: Data were from double-blind extensions of acute studies. The subjects met criteria for schizophrenia, schizophreniform disorder or schizoaffective disorder. Subjects had responded to acute therapy (Brief Psychiatric Rating Scale total score decreased > or = 40% from baseline (Studies 1, 2, and 3) or was < or = 18 (Studies 1 and 2)) and were out-patients at their last acute phase visit. Relapse was defined as hospitalisation for psychopathology. Subjects treated with olanzapine in the three studies were pooled to form the olanzapine group and subjects treated with haloperidol were pooled to form the haloperidol group. RESULTS: Olanzapine-treated subjects experienced less relapse (P = 0.034). The Kaplan-Meier estimated one-year risk of relapse was 19.7% with olanzapine and 28% with haloperidol. CONCLUSION: Olanzapine was superior to haloperidol in the maintenance therapy of schizophrenia and related psychoses. DECLARATION OF INTEREST: This work was sponsored by Eli Lilly and Company.

A double-blind, controlled comparison of the novel antipsychotic olanzapine versus haloperidol or placebo on anxious and depressive symptoms accompanying schizophrenia.

BACKGROUND: Depressive symptoms are a common feature of schizophrenia and may represent a core part of the illness. Where present, it has been associated with greater overall morbidity and mortality. Monotherapy with conventional dopamine antagonists may either worsen or bestow a limited therapeutic benefit. Accordingly the use of adjunctive thymoleptics has been explored. In contrast, olanzapine (OLZ), an atypical antipsychotic agent, offers a distinctive and pleotropic pharmacology suggestive of a broader efficacy profile than conventional neuroleptic agents. METHODS: In a 6-week placebo- and haloperidol (HAL)-controlled trial with 335 randomized subjects with chronic schizophrenia in an acute exacerbation, three fixed dose ranges of OLZ (5, 10, or 15 +/- 2.5 mg) were evaluated versus HAL (10-20 mg) or placebo. RESULTS: Baseline to endpoint change in the Brief Psychiatric Rating Scale including the anxiety-depression cluster (items 1, 2, 5, 9) was analyzed. Two dose ranges of OLZ (10 +/- 2.5, 15 +/- 2.5) were superior to placebo (p < 05) in improving mood status, whereas HAL was not. CONCLUSION: Contributions from a more selective mesolimbic dopaminergic profile, D1 or D4 activity, the release of dopamine/norepinephrine in the prefrontal cortex, and/or serotonin 5-HT2A,C antagonism may explain the differential benefit seen with OLZ in the treatment of comorbid anxious and depressive symptoms in schizophrenia.

Validation of an automated up-timer for measurement of mobility in older adults.

OBJECTIVE: To test the reliability, validity and utility of an "up-timer", an automated device to measure time spent standing and walking. DESIGN: Repeat measurement of mobility one week apart in a convenience sample. SETTING: Hostel and nursing homes in Melbourne. PARTICIPANTS: 26 hostel and 24 nursing home residents (aged 70-99 years) participated. They were mobile, with or without the use of walking aids or personal assistance. OUTCOME MEASURES: "Up-time" (measured with the up-timer); functional activity (measured with the Barthel Index, Functional Independence Measure, Timed Up & Go, and Human Activity Profile); and disability (measured by the Rapid Disability Rating Scale). RESULTS: The test-retest reliability of the up-timer was high (Pearson's r = 0.84; P < 0.001). Pearson's correlation between the up-timer results and results of functional and disability measures ranged from r = 0.47 to r = 0.55. The functional measures correlated more highly among themselves (r = 0.79 to r = 0.92). The performance-based Timed Up & Go test had moderate levels of correlation with both the up-timer and the functional measures. Use of the device was well accepted by both participants and staff. CONCLUSIONS: The up-timer is a practical, objective and reliable means of measuring mobility. The useful information it provides is different from, but overlaps with, that obtained from subjective observation or self report. It will complement existing subjective and performance-based measures of activity and mobility.

Double-blind comparison of olanzapine versus risperidone in the treatment of schizophrenia and other psychotic disorders.

Olanzapine and risperidone, both second-generation antipsychotic agents, represent two different pharmacologic strategies. Although they share some in vitro properties, they differ by virtue of their chemical structure, spectrum of receptor binding affinities, animal neuropharmacology, pharmacokinetics, and in vivo neuroimaging profile. Based on such differences, it was hypothesized that the two compounds would show distinct safety and/or efficacy characteristics. To test this hypothesis, an international, multicenter, double-blind, parallel-group, 28-week prospective study was conducted with 339 patients who met DSM-IV criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder. Results of the study indicated that both olanzapine and risperidone were safe and effective in the management of psychotic symptoms. However, olanzapine demonstrated significantly greater efficacy in negative symptoms (Scale for Assessment of Negative Symptoms summary score), as well as overall response rate (> or = 40% decrease in the Positive and Negative Syndrome Scale total score). Furthermore, a statistically significantly greater proportion of the olanzapine-treated than risperidone-treated patients maintained their response at 28 weeks based on Kaplan-Meier survival curves. The incidence of extrapyramidal side effects, hyperprolactinemia, and sexual dysfunction was statistically significantly lower in olanzapine-treated than risperidone-treated patients. In addition, statistically significantly fewer adverse events were reported by olanzapine-treated patients than by their risperidone-treated counterparts. Thus, the differential preclinical profiles of these two drugs were also evident in a controlled, clinical investigation. Olanzapine seemed to have a risk-versus-benefit advantage.

Blind, controlled, long-term study of the comparative incidence of treatment-emergent tardive dyskinesia with olanzapine or haloperidol.

OBJECTIVE: Tardive dyskinesia is a serious and common complication of neuroleptic treatment. Olanzapine is a novel antipsychotic agent exhibiting regional mesolimbic dopaminergic selectivity and a broad-based pharmacology encompassing serotonin, dopamine, muscarinic, and adrenergic receptor binding affinities. The authors' goal was to compare the incidence of tardive dyskinesia among patients receiving olanzapine and those receiving the conventional dopamine 2 antagonist haloperidol. METHOD: Data were analyzed from three actively controlled and blind long-term responder studies of subjects meeting DSM-III-R criteria for schizophrenia, schizophreniform disorder, or schizoaffective disorder treated with olanzapine (N = 707, up to 20 mg/day, 237 median days of exposure) or haloperidol (N = 197, up to 20 mg/day, 203 median days of exposure) who did not have evidence of tardive dyskinesia at baseline. All of the subjects had a chronic disease course (mean greater than 10 years), and there were no significant between-treatment group differences in demographic or disease characteristics. The Abnormal Involuntary Movement Scale and research diagnostic criteria for tardive dyskinesia were used to define the comparative incidence rates of long-term treatment-emergent tardive dyskinesia. RESULTS: The incidence of newly emergent tardive dyskinesia at any visit after baseline, at the final visit, and at the final two clinical assessments was statistically significantly lower among olanzapine-treated patients than among haloperidol-treated patients. CONCLUSIONS: These findings support an atypical extrapyramidal symptom profile and the potential of a significantly lower risk of tardive dyskinesia with olanzapine than with haloperidol among patients requiring maintenance antipsychotic treatment.

Olanzapine versus haloperidol: acute phase results of the international double-blind olanzapine trial.

A 6-week acute phase of an international 1-year double-blind study was conducted comparing three dose ranges of olanzapine (5 +/- 2.5 mg/day, 10 +/- 2.5 mg/day, and 15 +/- 2.5 mg/day) with a fixed dose of olanzapine (1.0 mg/day) and with a dose range of haloperidol (15 +/- 5 mg/day) in the treatment of 431 patients with schizophrenia. The purpose was to determine whether olanzapine demonstrated a dose-related ability to decrease overall psychopathology with minimal associated extrapyramidal symptoms in patients with schizophrenia. The high-dose olanzapine group showed statistically significantly greater improvement in overall psychopathology based on mean change in the CGI Severity score and statistically significantly greater improvement in positive psychotic symptoms based on mean change in both the BPRS positive score and the PANSS positive score compared with the 1.0-mg/day olanzapine group. Analyses indicated that an increasing dose-response curve was observed across the range of all olanzapine dose groups. Acute extrapyramidal syndromes were reported less frequently among all olanzapine groups compared with the haloperidol group. Endpoint mean change on both the Simpson-Angus Scale and the Barnes Akathisia Scale reflected improvement for all olanzapine treatment groups compared with worsening for the haloperidol group. Olanzapine was associated with weight gain but did not appear to have any clinically meaningful effect on vital signs. Although olanzapine was associated with some increase in prolactin concentrations, increases were transient, occurred less often, and were of lesser magnitude than those observed with haloperidol.

Extrapyramidal symptoms and tolerability of olanzapine versus haloperidol in the acute treatment of schizophrenia.

BACKGROUND: A relative lack of extrapyramidal symptoms (EPS, i.e., the syndromes of dystonia, parkinsonism, akathisia, dyskinesia) is one criterion used to determine whether an antipsychotic is "atypical." The extrapyramidal symptom profiles of the novel antipsychotic olanzapine and the conventional antipsychotic haloperidol were compared in a population of 2606 patients from three well-controlled prospective clinical trials. METHOD: Extrapyramidal symptom data were analyzed for 1796 patients treated with olanzapine (5 to 20 mg/day) and 810 patients treated with haloperidol (5 to 20 mg/day) for up to 6 weeks of therapy. Patients were monitored weekly by three methods of extrapyramidal symptom assessment: (1) detection of extrapyramidal adverse events (signs and symptoms) by casual observation, nonprobing inquiry, and spontaneous report; (2) objective rating scale scores: and (3) use of concomitant anticholinergic medications. Emergence of EPS was assessed by (1) analysis of the incidence of extrapyramidal syndrome categories based on adverse events, (2) the incidence of extrapyramidal syndromes based on categorical analysis of rating scale scores, (3) analysis of mean maximum change in rating scale scores, and (4) categorical analysis of anticholinergic medication use. Outcome of EPS was assessed by (1) analysis of mean change in rating scale scores at endpoint and (2) mean anticholinergic use at endpoint. RESULTS: Olanzapine was statistically significantly (p = .014, p < .001) superior to haloperidol in all four analyses related to emergence of EPS and in the two analyses related to outcome. Furthermore, during acute treatment, statistically significantly fewer patients treated with olanzapine (0.3%) discontinued the study because of any extrapyramidal adverse event than patients treated with haloperidol (2.7%, p < .001). CONCLUSION: Olanzapine exhibited a statistically significantly lower extrapyramidal symptom profile than the conventional antipsychotic haloperidol at comparably effective antipsychotic doses. The lower extrapyramidal symptom profile with olanzapine was evident despite statistically significantly more frequent use of anticholinergic drugs among haloperidol-treated patients. Fewer olanzapine-treated than haloperidol-treated patients discontinued because of EPS, suggesting that olanzapine should contribute to better compliance with longer term maintenance treatment, with minimal anticholinergic-associated events.

Olanzapine versus haloperidol in the treatment of schizophrenia and schizoaffective and schizophreniform disorders: results of an international collaborative trial.

OBJECTIVE: This international, multicenter double-blind trial was designed to compare the therapeutic profile of an atypical antipsychotic, olanzapine, with that of a conventional dopamine D2 antagonist, haloperidol. METHOD: A total of 1,996 patients at 174 sites in Europe and North America were randomly assigned to treatment with olanzapine (N = 1,336) or haloperidol (N = 660) over 6 weeks. The primary efficacy analysis involved the mean change from baseline to endpoint in total scores on the Brief Psychiatric Rating Scale (BPRS). Secondary analyses included comparisons of the mean change in positive and negative symptoms, comorbid depression, extrapyramidal symptoms, and overall drug safety. RESULTS: Olanzapine demonstrated clinical results superior to those of haloperidol on overall improvement according to the BPRS and on every secondary measure, including depression. Olanzapine was also associated with significantly fewer discontinuations of treatment due to lack of drug efficacy or adverse events. Substantially more olanzapine-treated patients (66.5%) than haloperidol-treated patients (46.8%) completed 6 weeks of therapy. Statistically significant advantages of olanzapine treatment were related to 1) change in negative symptoms, 2) extrapyramidal symptom profile, 3) effect on prolactin levels, and 4) response rate. CONCLUSIONS: Olanzapine shows a superior and broader spectrum of efficacy in the treatment of schizophrenic psychopathology, with a substantially more favorable safety profile, than haloperidol. It meets several of the criteria for a novel atypical antipsychotic agent.

Efficacy of olanzapine: an overview of pivotal clinical trials.

Olanzapine is a new "atypical" antipsychotic agent that belongs chemically to the thienobenzodiazepine class. Its relatively greater binding affinity for 5-HT2 compared to D2 receptors makes it similar to the atypical agent clozapine, a serotonin/dopamine antagonist. Four double-blind pivotal studies, which compare olanzapine to placebo and/or haloperidol, are presented. The results suggest that olanzapine is as effective as haloperidol for positive symptoms and more effective than haloperidol for the treatment of the negative symptoms of schizophrenia.

Safety of olanzapine.

Clinical safety data for treatment of acute schizophrenia with olanzapine, a new atypical antipsychotic agent, are summarized. The primary clinical trial safety database included 2500 patients treated with olanzapine, 810 with haloperidol, and 236 with placebo. The overall discontinuation rate from olanzapine treatment was low. Significant adverse events included somnolence, weight gain, and asymptomatic treatment-emergent transaminase elevation. Minimal parkinsonism and akathisia with rare dystonia were noted. No hematotoxicity was noted. The incidence of seizures and sexual dysfunction was rare.

Interspecific comparisons of the unusually long 5' leader of the Drosophila ecdysone-inducible gene E74A.

The Drosophila melanogaster E74A gene is expressed in response to the steroid hormone ecdysone. Its product is a site-specific DNA-binding protein that is believed to play an important role in the normal development and metamorphosis of the fly. In addition to being under the transcriptional control of ecdysone and its receptor, there is evidence for translational regulation of the E74A mRNA. The E74A mRNA 5' leader is unusually long (nearly 1.9 kb) and contains 17 AUGs, suggesting that translation of the mRNA would be rather inefficient. To identify features and sequences that might be important in regulating E74A translation, we determined the nucleotide sequences of the 5' leaders from the E74A-homologous genes of D. pseudoobscura and D. virilis, comparing them to D. melanogaster. Several conserved characteristics and specific sequences were identified. In addition to conservation of the relative distances separating the three E74A gene exons encoding the 5' leader, all three species have maintained the extensive length of the leader as well as multiple AUGs. Within the 5' leader are numerous conserved sequences, several of which are found at the two ends of the leader and at splice site junctions, where sequence conservation might be expected. A 53-nucleotide sequence element and a 30-nucleotide element in exon 2 are highly conserved and are proposed as candidates for an internal ribosome entry site (IRES) of the E74A mRNA.

Expression of Escherichia coli pabA.

Escherichia coli pabA encodes the glutamine amidotransferase subunit of p-aminobenzoate synthase. p-Aminobenzoate synthase catalyzes the conversion of chorismate and glutamine to 4-amino-4-deoxychorismate, which is then converted to p-aminobenzoate by a 4-amino-4-deoxychorismate lyase. The 5'-terminal segment of pabA was previously shown to be transcribed from two different promoters, one near the pabA coding sequence (P1) and one preceding fic (P2). However, a pabA-lacZ translational fusion was expressed only from the mRNA originating at P1. We have determined that expression of a pabA-lacZ chromosomal fusion is not changed by p-aminobenzoate limitation, growth rate, catabolite repression, overexpression of either p-aminobenzoate synthase subunit, or gene dosage of pabA and pabB. The lack of pabA expression from P2 appears to be the result of a stable secondary structure in the intergenic space preceding pabA that sequesters the pabA ribosome binding site. Disruption of the secondary structure by mutation allowed expression of pabA from P2, as did translation of ribosomes into the fic-pabA intergenic region.