Impressive Response with Brexpiprazole in Ekbom’s syndrome

Introduction

Antipsychotics are the mainstream treatment of delusional disorder. However, limited therapeutic effect was recognized due to side effect and lack of insight.

Objectives

This article presents a case with Ekbom’s syndrome, also known as delusional parasitosis, who has significant response with Brexpiprazole.

Methods

A 58-year-old female developed her very first episode of psychosis 3 weeks before she visited our emergency department. Delusion of spiders laying eggs and bitsy spiders crawling over her body was claimed, followed by depressed mood and insomnia. The patient denied any substance use in recent months. Examination including biochemical studies, complete blood count, vitamin, and endocrine during admission were all normal. Brain image revealed senile cortical atrophy without apparent acute infarction. Cognitive abilities screening instrument (CASI) revealed total score 75, indicating borderline cognitive function. Ophthalmologist and dermatologist were consulted, and no specific abnormality was found.

Results

Brexpiprazole 2mg was prescribed. After 3 weeks of treatment, the delusion improved with less parasitosis content. We discharged the patient, and kept following her at outpatient department with Brexpiprazole 2mg for 2 months. We tried to taper Brexpiprazole to 1mg at clinic, but her delusional parasitosis relapsed within 1 month. Therefore, we titrated the medication back to 2mg, and kept some dosage for 4 months. No more relapse of psychosis or significant movement dysfunction was observed. The total treatment course was 7 months.

Conclusions

Brexpiprazole, with its D2 partial agonism, shows impressive antipsychotic effect to Ekbom’s syndrome. Little side effect was observed in clinical practice, making Brexpiprazole a worth-trying psychopharmacological management of delusional parasitosis.

Disclosure

No significant relationships.

Miniaturized optical frequency reference for next-generation portable optical clocks

Optical frequency standards, or lasers stabilized to atomic or molecular transitions, are widely used in length metrology and laser ranging, provide a backbone for optical communications and lie at the heart of next-generation optical atomic clocks. Here we demonstrate a compact, low-power optical frequency reference based on the Doppler-free, two-photon transition in rubidium-87 at 778 nm implemented on a micro-optics breadboard. Our optical reference achieves a fractional frequency instability of 2.9×10^-12/τ for averaging times τ less than 10³ s, has a volume of ≈35 cm³ and operates on ≈450 mW of electrical power. The advanced optical integration presented here demonstrates a key step towards the development of compact optical clocks and the broad dissemination of SI-traceable wavelength references.

0659 A Safe and Precise Tongue Base Surgery for Obstructive Sleep Apnea: Real-Time Intraoperative Ultrasound-Assisted Transoral Robotic Surgery

Introduction

Lingual artery (LA) injury is a devastating complication of tongue base surgery. Compared with the anatomic findings of computed tomography angiography (CTA), intraoperative blade of mouth gag might change the thickness of base of tongue (BOT) and anatomy of LA. We aimed to investigate the position of LA in the BOT with intraoperative ultrasound (IOU) imaging during transoral robotic surgery (TORS), and evaluate the bleeding complications when assisted with / without IOU.

Methods

Adult obstructive sleep apnea (OSA) patients who received TORS in BOT resection were recruited since 2016. Assessment tools were pre-op over-night hospital polysomnography (PSG) and anatomy-based Friedman Staging System. Ultrasound imaging was utilized to identify anatomic parameters of LA in BOT, including distance to midline, arterial depth and diameter.

Results

Ninety-three OSA patients (82 male, 88.2%) were analyzed. The mean age was 42.2±10.0 years old and body mass index was 29.2±4.5 kg/m2. The average apnea hypopnea index (AHI) was 58.1±21.4 events/hour. There were 66 (71.0%), 24 (25.8%) and 3 (3.2%) patients in Friedman stages II, III and IV, respectively. Seventy patients underwent TORS with IOU had shorter operation time (191.7±3.8 minutes) than 23 patients without IOU (220.1±6.6 minutes), less total blood loss (11.3±10.8 versus 19.6±26.7 ml), and more BOT tissue reduction volume (7.1±2.5 versus 3.9±1.6 ml). Significant predictors of arterial depth were higher AHI level during rapid-eye-movement (REM) sleep stage (p=0.038), bigger tonsil size (p=0.034) and more elevated Friedman tongue position (p=0.012). Postoperative complication associated with LA injury was not found in the patients with use of IOU.

Conclusion

When tongue retracted with blade, the distance to midline and depth of LA were altered in BOT. With IOU assisted, surgeon could identify LA position confidently. It is expectable to maximize efficiency and minimize catastrophic bleeding complications when OSA patients received TORS in BOT resection.

Support

nil

An adaptable soft-mold embossing process for fabricating optically-accessible, microfeature-based culture systems and application toward liver stage antimalarial compound testing

Advanced cell culture methods for modeling organ-level structure have been demonstrated to replicate in vivo conditions more accurately than traditional in vitro cell culture. Given that the liver is particularly important to human health, several advanced culture methods have been developed to experiment with liver disease states, including infection with Plasmodium parasites, the causative agent of malaria. These models have demonstrated that intrahepatic parasites require functionally stable hepatocytes to thrive and robust characterization of the parasite populations' response to investigational therapies is dependent on high-content and high-resolution imaging (HC/RI). We previously reported abiotic confinement extends the functional longevity of primary hepatocytes in a microfluidic platform and set out to instill confinement in a microtiter plate platform while maintaining optical accessibility for HC/RI; with an end-goal of producing an improved P. vivax liver stage culture model. We developed a novel fabrication process in which a PDMS soft mold embosses hepatocyte-confining microfeatures into polystyrene, resulting in microfeature-based hepatocyte confinement (μHEP) slides and plates. Our process was optimized to form both microfeatures and culture wells in a single embossing step, resulting in a 100 μm-thick bottom ideal for HC/RI, and was found inexpensively amendable to microfeature design changes. Microfeatures improved intrahepatic parasite infection rates and μHEP systems were used to reconfirm the activity of reference antimalarials in phenotypic dose-response assays. RNAseq of hepatocytes in μHEP systems demonstrated microfeatures sustain hepatic differentiation and function, suggesting broader utility for preclinical hepatic assays; while our tailorable embossing process could be repurposed for developing additional organ models.

Upregulation of Haploinsufficient Gene Expression in the Brain by Targeting a Long Non-coding RNA Improves Seizure Phenotype in a Model of Dravet Syndrome

Dravet syndrome is a devastating genetic brain disorder caused by heterozygous loss-of-function mutation in the voltage-gated sodium channel gene SCN1A. There are currently no treatments, but the upregulation of SCN1A healthy allele represents an appealing therapeutic strategy. In this study we identified a novel, evolutionary conserved mechanism controlling the expression of SCN1A that is mediated by an antisense non-coding RNA (SCN1ANAT). Using oligonucleotide-based compounds (AntagoNATs) targeting SCN1ANAT we were able to induce specific upregulation of SCN1A both in vitro and in vivo, in the brain of Dravet knock-in mouse model and a non-human primate. AntagoNAT-mediated upregulation of Scn1a in postnatal Dravet mice led to significant improvements in seizure phenotype and excitability of hippocampal interneurons. These results further elucidate the pathophysiology of Dravet syndrome and outline a possible new approach for the treatment of this and other genetic disorders with similar etiology.

Basic biology and therapeutic implications of lncRNA

Long non-coding RNAs (lncRNA), a class of non-coding RNA molecules recently identified largely due to the efforts of FANTOM, and later GENCODE and ENCODE consortia, have been a subject of intense investigation in the past decade. Extensive efforts to get deeper understanding of lncRNA biology have yielded evidence of their diverse structural and regulatory roles in protecting chromosome integrity, maintaining genomic architecture, X chromosome inactivation, imprinting, transcription, translation and epigenetic regulation. Here we will briefly review the recent studies in the field of lncRNA biology focusing mostly on mammalian species and discuss their therapeutic implications.

Comparison of measured and self-reported anthropometric information among firefighters: implications and applications

This study evaluated the accuracy of self-reported body weight and height compared to measured values among firefighters and identified factors associated with reporting error. A total of 863 male and 88 female firefighters in four US regions participated in the study. The results showed that both men and women underestimated their body weight ( - 0.4 ± 4.1, - 1.1 ± 3.6 kg) and overestimated their height (29 ± 18 , 17 ± 16 mm). Women underestimated more than men on weight (p = 0.022) and men overestimated more than women on height (p < 0.001). Reporting errors on weight were increased with overweight status (p < 0.001) and were disproportionate among subgroups. About 27% men and 24% women had reporting errors on weight greater than ± 2.2 kg, and 59% men and 28% women had reporting errors on height greater than 25 mm.

Three-dimensional elastomeric scaffolds designed with cardiac-mimetic structural and mechanical features

Tissue-engineered constructs, at the interface of material science, biology, engineering, and medicine, have the capacity to improve outcomes for cardiac patients by providing living cells and degradable biomaterials that can regenerate the native myocardium. With an ultimate goal of both delivering cells and providing mechanical support to the healing heart, we designed three-dimensional (3D) elastomeric scaffolds with (1) stiffnesses and anisotropy mimicking explanted myocardial specimens as predicted by finite-element (FE) modeling, (2) systematically varied combinations of rectangular pore pattern, pore aspect ratio, and strut width, and (3) structural features approaching tissue scale. Based on predicted mechanical properties, three scaffold designs were selected from eight candidates for fabrication from poly(glycerol sebacate) by micromolding from silicon wafers. Large 20×20 mm scaffolds with high aspect ratio features (5:1 strut height:strut width) were reproducibly cast, cured, and demolded at a relatively high throughput. Empirically measured mechanical properties demonstrated that scaffolds were cardiac mimetic and validated FE model predictions. Two-layered scaffolds providing fully interconnected pore networks were fabricated by layer-by-layer assembly. C2C12 myoblasts cultured on one-layered scaffolds exhibited specific patterns of cell elongation and interconnectivity that appeared to be guided by the scaffold pore pattern. Neonatal rat heart cells cultured on two-layered scaffolds for 1 week were contractile, both spontaneously and in response to electrical stimulation, and expressed sarcomeric α-actinin, a cardiac biomarker. This work not only demonstrated several scaffold designs that promoted functional assembly of rat heart cells, but also provided the foundation for further computational and empirical investigations of 3D elastomeric scaffolds for cardiac tissue engineering.

Validating the acute heart failure index for patients presenting to the emergency department with decompensated heart failure

BACKGROUND

The acute heart failure index (AHFI) is a previously derived prediction rule to identify patients presenting to emergency departments (ED) with decompensated heart failure (DHF) at low risk of early life-threatening events.

STUDY OBJECTIVES

To validate the AHFI prospectively.

METHODS

Using a prospective cohort study, adult patients presenting to an urban university hospital ED with DHF were included. Data on 21 variables were gathered to calculate the AHFI. Primary endpoints included inpatient death and non-fatal serious outcomes (myocardial infarction, ventricular fibrillation, cardiogenic shock, cardiac arrest, intubation, or cardiac reperfusion). Secondary endpoints included death from any cause or readmission for heart failure within 30 days. Primary and secondary endpoint rates were calculated with 95% CI for the low and higher-risk subgroups.

RESULTS

259 patients were enrolled. 245/259 (95%) were admitted. 60/259 (23%) met low-risk criteria, of whom 1/60 (1.7%, CI 0.04 to 8.9) was discharged after sustaining pulseless electrical activity arrest. The comparable primary outcome rate in the derivation study was 1.4% (CI 1.1 to 1.7). 17/199 (8.5%, CI 5.1 to 13.3) higher-risk patients experienced an endpoint, compared with 13.3% (CI 12.9 to 13.7) in the derivation cohort. One low-risk patient (1.7%, CI 0.04 to 8.9) died within 30 days, and five (8.3%, CI 2.8 to 18.4) were readmitted. Corresponding rates in the derivation study were 2% and 5%, respectively.

CONCLUSION

The results are consistent with those previously reported for the low-risk subgroup of the AHFI. Further research is needed to determine the impact, safety and full range of generalisability of the AHFI as an adjunct to decision making.

Digital 3-d headforms representative of chinese workers

Headforms are useful for designing and testing various types of personal protective equipment used to protect millions of workers from occupational hazards in China. Although the Chinese national standard of head-and-face dimensions for adults was first published in 1981, headforms based on those dimensions were never developed. In 2006, an anthropometric survey of 3000 Chinese civilian workers was conducted. As part of the survey, 350 subjects were scanned with a Cyberware 3D Rapid Digitizer. The manual measurements and 3-D digital scans from this survey were used to develop 3-D digital headforms that represent Chinese workers.

OBJECTIVE

The objective of this study was to develop headforms that represent today's Chinese workers.

METHODS

Ten facial dimensions relevant to respirator fit were chosen for defining a principal component analysis model which divides the user population into five face size categories. Mean facial dimensions from manual measurements were then computed to target the ideal facial dimensions for each size category. Five scans were chosen from each face size category to be used in the construction process. Selected scans were then averaged to construct a representative headform for each face size category.

RESULTS

Five digital 3-D headforms were developed: small, medium, large, long/narrow, and short/wide. These distinct sizes of digital 3-D headforms take into account the linear distance between landmarks as well as the surface contours captured during the 3-D scan. The dimensions of constructed headforms were within approximately 4 mm between the corresponding computed means and manual measurements of anthropometric landmarks for the sample population in each size category.

CONCLUSIONS

These new headforms represent the facial size and shape distribution of current Chinese workers and may be useful for respirator research and development. The Chinese medium headform has a wider face width, shorter face length, and smaller nose protrusion when compared with the current U.S. standard headforms. Upon validation, it may be useful to incorporate these dimensions into Chinese and international respiratory protective devices standards.

Functional endothelialized microvascular networks with circular cross-sections in a tissue culture substrate

Functional endothelialized networks constitute a critical building block for vascularized replacement tissues, organ assist devices, and laboratory tools for in vitro discovery and evaluation of new therapeutic compounds. Progress towards realization of these functional artificial vasculatures has been gated by limitations associated with the mechanical and surface chemical properties of commonly used microfluidic substrate materials and by the geometry of the microchannels produced using conventional fabrication techniques. Here we report on a method for constructing microvascular networks from polystyrene substrates commonly used for tissue culture, built with circular cross-sections and smooth transitions at bifurcations. Silicon master molds are constructed using an electroplating process that results in semi-circular channel cross-sections with smoothly varying radii. These master molds are used to emboss polystyrene sheets which are then joined to form closed bifurcated channel networks with circular cross-sections. The mechanical and surface chemical properties of these polystyrene microvascular network structures enable culture of endothelial cells along the inner lumen. Endothelial cell viability was assessed, documenting nearly confluent monolayers within 3D microfabricated channel networks with rounded cross-sections.

Acculturation among three racial/ethnic groups of host and immigrant adolescents

This study compares Latino host, Latino immigrant, Asian-American host, Asian-American immigrant and European-American host groups of adolescents with respect to four acculturation-related variables: ethnic identity exploration, ethnic identity affirmation/belonging, outgroup orientation, and American identity. Using the five ethno-generational categories as a grouping variable, we conducted analyses of 313 survey responses to the acculturation items at two time periods, 9 weeks apart. Results showed that differences among the three host racial/ethnic groups can best be explained by a group dominance perspective, whereby the two racial/ethnic minority groups are more similar to each other than they are to the European-American group. Furthermore, the relationship between American identity and ethnic identity components is stronger among the three host groups, as compared to the immigrant groups. Implications for future research with adolescent members of the host group whose heritage culture is non-European are drawn.

Genome sequencing of a 239-kb region of rice chromosome 10L reveals a high frequency of gene duplication and a large chloroplast DNA insertion

In this study we describe a 239-kb region on the long arm of rice chromosome 10 that contains a high density (71%) of locally duplicated genes, including 24 copies of a glutathione S-transferase gene. Intriguingly, embedded within this cluster is a large insertion (approximately 33 kb) of rice (Oryza sativa) chloroplast DNA that is derived from two separate regions of the chloroplast genome. We used DNA fiber-based fluorescence in situ hybridization (fiber-FISH) analyses of O. sativa spp. japonica nuclei to confirm that the insertion of organellar DNA was not a cloning artifact. The sequence of the chloroplast insertion is nearly identical (99.7% identity) to the corresponding regions in the published rice chloroplast genome sequence, suggesting that the transfer event occurred recently. PCR amplification and sequence analysis in two subspecies of rice, O. sativa spp. japonica and spp. indica, indicates that the transfer event predated the divergence of these two subspecies. The chloroplast insertion is flanked by a 2.1-kb perfect direct repeat that is unique to this location in the rice genome.

Anchoring of rice BAC clones to the rice genetic map in silico

A wealth of molecular resources have been developed for rice genomics, including dense genetic maps, expressed sequence tags (ESTs), yeast artificial chromosome maps, bacterial artificial chromosome (BAC) libraries and BAC end sequence databases. Integration of genetic and physical maps involves labor-intensive empirical experiments. To accelerate the integration of the bacterial clone resources with the genetic map for the International Rice Genome Sequencing Project, we cleaned and filtered the available EST and BAC end sequences for repetitive sequences and then searched all available rice genetic markers with our filtered databases. We identified 418 genetic markers that aligned with at least one BAC end sequence with >95% sequence identity, providing a set of large insert clones with an average separation of 1 Mb that can serve as nucleation points for the sequencing phase of the International Rice Genome Sequencing Project.

Citron rho-interacting kinase, a novel tissue-specific ser/thr kinase encompassing the Rho-Rac-binding protein Citron

We have identified a novel serine/threonine kinase belonging to the myotonic dystrophy kinase family. The kinase can be produced in at least two different isoforms: a approximately 240-kDa protein (Citron Rho-interacting kinase, CRIK), in which the kinase domain is followed by the sequence of Citron, a previously identified Rho/Rac binding protein; a approximately 54-kDa protein (CRIK-short kinase (SK)), which consists mostly of the kinase domain. CRIK and CRIK-SK proteins are capable of phosphorylating exogenous substrates as well as of autophosphorylation, when tested by in vitro kinase assays after expression into COS7 cells. CRIK kinase activity is increased severalfold by coexpression of costitutively active Rho, while active Rac has more limited effects. Kinase activity of endogenous CRIK is indicated by in vitro kinase assays after immunoprecipitation with antibodies recognizing the Citron moiety of the protein. When expressed in keratinocytes, full-length CRIK, but not CRIK-SK, localizes into corpuscular cytoplasmic structures and elicits recruitment of actin into these structures. The previously reported Rho-associated kinases ROCK I and II are ubiquitously expressed. In contrast, CRIK exhibits a restricted pattern of expression, suggesting that this kinase may fulfill a more specialized function in specific cell types.

Rad53 FHA domain associated with phosphorylated Rad9 in the DNA damage checkpoint

The Rad53 protein kinase of Saccharomyces cerevisiae is required for checkpoints that prevent cell division in cells with damaged or incompletely replicated DNA. The Rad9 protein was phosphorylated in response to DNA damage, and phosphorylated Rad9 interacted with the COOH-terminal forkhead homology-associated (FHA) domain of Rad53. Inactivation of this domain abolished DNA damage-dependent Rad53 phosphorylation, G2/M cell cycle phase arrest, and increase of RNR3 transcription but did not affect replication inhibition-dependent Rad53 phosphorylation. Thus, Rad53 integrates DNA damage signals by coupling with phosphorylated Rad9. The hitherto uncharacterized FHA domain appears to be a modular protein-binding domain.

Inhibitory function of p21Cip1/WAF1 in differentiation of primary mouse keratinocytes independent of cell cycle control

The cyclin-dependent kinase inhibitor p21(Cip1/WAF1) has been implicated as an inducer of differentiation. However, although expression of p21 is increased in postmitotic cells immediately adjacent to the proliferative compartment, its expression is decreased in cells further along the differentiation program. Expression of the p21 protein was decreased in terminally differentiated primary keratinocytes of mice, and this occurred by a proteasome-dependent pathway. Forced expression of p21 in these cells inhibited the expression of markers of terminal differentiation at both the protein and messenger RNA levels. These inhibitory effects on differentiation were not observed with a carboxyl-terminal truncation mutant or with the unrelated cyclin-dependent kinase inhibitor p16(INK4a), although all these molecules exerted similar inhibition of cell growth. These findings reveal an inhibitory role of p21 in the late stages of differentiation that does not result from the effects of p21 on the cell cycle.

Individual variation in D2 dopamine receptor occupancy in clozapine-treated patients

OBJECTIVE

The objectives of this study were 1) to pursue the question of clozapine's striatal D2 occupancy in relation to its clinical effectiveness; 2) to investigate the relation between schizophrenic symptoms, clozapine blood levels, and estimated D2 occupancy during clinically stable and unstable conditions; and 3) to examine long-term stability in D2 occupancy.

METHOD

Specific binding of the D2 radioligand [123I]benzamide ([123I]IBZM) was studied with single photon emission computed tomography in 13 patients with schizophrenia when they were clinically stable during chronic clozapine treatment, after clozapine dose reduction of > or = 50%, and in a subgroup (N = 7) after restabilization on clozapine regimens. Clozapine's estimated D2 occupancy was based on comparison with values from drug-free normal subjects.

RESULTS

A wide range of estimated D2 occupancies (18% to > or = 80%) were associated with sustained, favorable response to clozapine without correlation with residual symptoms. Clozapine blood levels were negatively related to [123I]IBZM specific binding. Acute dose reduction was associated with predicted worsening in positive and negative symptoms and increases in [123I]IBZM specific binding. Independent of clozapine blood level, patients with more symptoms showed lower [123I]IBZM specific binding, consistent with competition of endogenous dopamine for D2 binding sites in patients with greater symptoms. Restabilization on clozapine regimens produced D2 occupancies closely correlated with baseline values.

CONCLUSIONS

There was no evidence for a critical degree of D2 occupancy required to sustain clozapine's therapeutic effects across subjects. Simple linear regression was the best-fit model for clozapine's D2 occupancy. Longitudinal follow-up suggests stability over time of D2 occupancy in relation to dose and clinical response within individual patients.

Velocity-dependent ankle torque in the normal rat

We evaluated the velocity-dependent ankle torque and associated activity of the ankle extensor muscle stretch reflexes in normal rats. A 287% increase in velocity-dependent ankle torque was observed at the highest velocity tested compared with the lowest velocity. Low velocity torques were minimally altered during general anesthesia that depressed EMG activity by up to 90%. However, velocity-dependent torque during higher velocity ankle rotations (306-612 degrees s-1 correlated with parallel increases in EMG magnitude recorded from the triceps surae muscles. General anesthesia (pentobarbital) abolished 61% of the velocity-dependent ankle torque at 612 degrees s-1. We conclude that ankle torque and ankle extensor muscle activity display velocity enhancement over a broad range. These observations indicate that protocols designed to assess ankle torque in the rat should use instrumentation to produce a broad range of velocities up to at least 600 degrees s-1.

Flexural behavior of visible light-cured composites as a function of temperature under water immersion test conditions

OBJECTIVES

The purpose of this study was to investigate the effect of temperature of the flexural behavior for four visible light-cured hybrid composite materials.

METHODS

Light-cured samples were post-cured for 24 h at 37 degrees C in 100% relative humidity prior to testing. Flexural tests were performed at the following water immersion temperatures: 5, 15, 25, 37, 45 and 55 degrees C, as well as in the dry condition which served as control. The following flexural property parameters were obtained as a function of test temperature: flexural strength, sigma fs, flexural modulus, Efs, flexural stress at 0.06% total offset strain, 0.06% (yield stress), and the total displacement at fracture, delta fs. Statistically significant differences (p < 0.01) in flexural parameters were noted for all the materials as a function of test temperature.

RESULTS

The yield stress, sigma 0.06% was found to be most sensitive to thermomechanical changes. The results of this study indicate significant softening due to temperature under wet immersion test conditions for all materials. The temperature range at which two of the materials show significant reduction in yield stress compare well with "Wet Tg" values obtained by dynamic thermal mechanical analysis (Culbertson et al., 1990; 1991).

SIGNIFICANCE

The effect of damage accumulation on surface or subsurface microstructure due to transient thermomechanical loads needs to be taken into account in the correlation of in vitro and in vivo wear or creep behavior.

Effects of clozapine and fluphenazine treatment on responses to m-chlorophenylpiperazine infusions in schizophrenia

OBJECTIVE

To explore serotonin function in patients with schizophrenia during typical and atypical neuroleptic treatment. We hypothesized that clinically relevant doses of the atypical neuroleptic clozapine would attenuate responses to the serotonin agonist m-chlorophenylpiperazine (m-CPP).

DESIGN AND INTERVENTIONS

m-CPP or placebo was administered intravenously over 90 seconds to patients who had been receiving no medications for at least 3 weeks. m-CPP was also administered during treatment with the typical neuroleptic fluphenazine and the atypical neuroleptic clozapine.

PATIENTS

Fifteen inpatients (two women and 13 men) who met DSM-III-R criteria for chronic schizophrenia (n = 13) or schizoaffective disorder (n = 2) participated in the study. Mean age (+/- SD) was 33.8 +/- 8.0 years.

MAIN OUTCOME MEASURES

Measures of m-CPP effects included plasma cortisol and prolactin, body temperature, and the Brief Psychiatric Rating Scale (BPRS). The final BPRS total score at approximately 12 weeks of treatment was used to assess response to clozapine.

RESULTS

m-CPP infusion significantly increased plasma cortisol and prolactin levels in drug-free patients. There was a range of behavioral responses while drug-free, but no statistically significant effects on BPRS total or BPRS factor scores. Clozapine treatment significantly blocked neuroendocrine responses to m-CPP, whereas fluphenazine had no effect. Clozapine also appeared to attenuate behavioral responses.

CONCLUSIONS

These results demonstrate that clozapine treatment has potent serotonin antagonist effects in patients with schizophrenia. This may be related to clozapine's therapeutic effects since patients with greater cortisol response to m-CPP while drug-free had a better subsequent response to clozapine.

Site density of mouse intestinal glucose transporters declines with age

To evaluate the effect of age on nutrient transport, the absorption rates of D-glucose, D-fructose, L-alanine, L-aspartate, L-leucine, L-lysine, L-proline, folic acid, and nicotinamide were determined in isolated jejunal tissues of young (6.7 mo old) and aged (23.7 and 27.0 mo old) mice (COBS:SFW). D-Glucose and D-fructose uptakes per milligram tissue were approximately 20-120% higher in the proximal jejunum and 15-50% higher in the distal jejunum of young mice. Amino acid and vitamin uptakes per milligram were also higher in young mice, but differences were not statistically significant. The number of Na(+)-D-glucose transporters per milligram tissue as estimated by specific phlorizin binding decreased with age. There was no age-related change in passive L-glucose permeability, in Kd of specific phlorizin binding, in transporter turnover rate, and in the molecular weight of the Na(+)-D-glucose transporter. Thus a reduction in D-glucose transporter site density fully accounts for the age-related decline in D-glucose transport rate per milligram small intestine.

Effect of lithium chloride on ornithine decarboxylase activity in rat adrenal

The effects of lithium chloride on ornithine decarboxylase (ODC) activity were compared in the adrenal and kidney of control (saline treated) and prolactin-treated rats. ODC activity was decreased in kidney of both groups of animals, the magnitude of the effect of lithium in the hormone-treated group varying with the time of administering the lithium relative to prolactin. The response in the adrenal was quite different. Following treatment with LiCl, there was a gradual increase in ODC activity from a low of 10-35 pmol CO2 x 30 min-1.mg protein-1 in control animals to values 20- to 30-fold greater at 5 h. In rats treated simultaneously with LiCl and prolactin, ODC activity was greater at 5 h than that observed in animals receiving either compound alone, indicating that their effects were additive. When LiCl was given 4 h after prolactin, i.e., 1 h before sacrifice, ODC activity decreased to a very low level at 5 h, as in other tissues. The increase in ODC activity in the adrenal following LiCl is of the same magnitude as the changes observed in tissues stimulated to undergo alterations in proliferation, differentiation, or metabolic or membrane activity by hormones and other external stimuli.

In vivo changes of catecholamines in hemiparkinsonian monkeys measured by microdialysis

In monkeys, unilateral intracarotid infusion of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) produces a useful model of hemiparkinsonism. To evaluate MPTP-induced neurochemical changes in vivo, brain microdialysis was employed to measure extracellular levels of dopamine and its metabolites in the neostriatum of normal and hemiparkinsonian rhesus monkeys (Macaca mulatta). The microdialysis probes were implanted bilaterally into the caudate nucleus and putamen at coordinates determined from magnetic resonance imaging. Dopamine and its metabolites were depleted in the MPTP-lesioned side versus the unlesioned side in hemiparkinsonian monkeys. Tyrosine hydroxylase immunocytochemistry revealed a complete unilateral denervation in the caudate nucleus and putamen and a total loss of tyrosine hydroxylase-immunoreactive cells in the substantia nigra pars compacta in those monkeys. Baseline levels of amines in the neostriatum in normal monkeys were not significantly different from those in the normal (non-MPTP-treated) side in hemiparkinsonian monkeys. These data demonstrate that brain microdialysis is a valuable tool for measuring in vivo neurochemical changes in nonhuman primate brains.

Methodology of microdialysis of neostriatum in hemiparkinsonian nonhuman primates

In vivo biochemical microdialysis in primate brain would greatly expand our understanding of functional neuronal systems. This work describes our efforts to establish a microdialysis system in primate brain. Seven anesthetized rhesus monkeys underwent magnetic resonance imaging (MRI) with the head fixed in a compatible stereotaxic frame. This allowed stereotaxic localization of the caudate nucleus and putamen. Guide cannulae were implanted and fixed to the skull. Microdialysis probes made from polyethylene and fused silica were inserted into the caudate and putamen through the guide cannulae and perfused at the rate of 1.3 microliters/min. The putamens were approached horizontally, while the caudate nuclei were reached via a 30 degrees-45 degrees angle from the vertical. Postdialysis MRI and histologic evaluation proved that all probes accurately arrived at the predetermined region. Our data show that MRI guided stereotaxis allows accurate placement of dialysis probes and that implantation of guide cannulae is a reliable and convenient way to perform repeated brain microdialysis procedures.

Inhibition of hormone-stimulated ornithine decarboxylase activity by lithium chloride

Effects of Li+ on hormone-stimulated ornithine decarboxylase (ODC) activity were determined in kidney and liver of rats treated with dexamethasone or prolactin (PRL) and also in cultured, PRL-stimulated Nb2 lymphoma cells. In both systems, LiCl led to rapid and marked decreases in ODC activity. The inhibitory effect of Li+ in exponentially growing Nb2 lymphoma cell cultures, measured at 45 min, was dose-dependent, ranging from 10% at 0.1 mM LiCl to 95% at 10 mM LiCl. Surprisingly, on continued incubation with 10 mM LiCl, the lymphoma cells partially overcame the inhibition, showing ODC activities which reached a maximal value of ca 50% of the control at 4.5 h. The inhibition by Li+ could not be reduced by adding myo-inositol to the culture medium. LiCl did not inhibit ODC activity when added to cell-free extracts of rat tissues and Nb2 lymphoma cells indicating it did not act directly on the enzyme; however, there is evidence that, in intact cells, Li+ enhances the rate of inactivation of the enzyme.

The effects of intravenous clomipramine on neurohormones in normal subjects

The neuroendocrine effects of iv administration of clomipramine (CMI), a serotonin reuptake inhibitor, were studied in normal subjects. Under double blind, placebo-controlled conditions, single 10- and 20-mg doses of CMI were administered. Ten milligrams of CMI led to significant increases in plasma PRL and cortisol concentrations; plasma ACTH increased slightly but not significantly. In contrast, plasma GH, melatonin, and norepinephrine concentrations did not increase. Plasma PRL, ACTH, and cortisol levels increased significantly after 20 mg CMI; again, there were no significant changes in plasma GH, melatonin, or norepinephrine concentrations. All subjects tolerated the 10-mg dose well, but the 20-mg dose caused nausea in three of six subjects. Desmethylclomipramine, a metabolite that inhibits reuptake of norepinephrine, was not detectable in plasma after either CMI dose. These results support the hypothesis that serotonin is involved in the regulation of PRL, cortisol, and ACTH in humans.

Isolation of a novel morphinan 3-O-diglucuronide metabolite from dog urine

Following oral administration of the narcotic antagonist nalmefene [17-(cyclopropylmethyl)-4,5 alpha-epoxy-6-methylenemorphinan-3,14-diol] labeled with 14C to the dog, approximately 50% of the dose was excreted in the urine as a highly polar water-soluble conjugate. Although this major metabolite could be hydrolyzed with beta-glucuronidase to yield nalmefene, the intact conjugate was chromatographically more polar on reversed-phase high-performance liquid chromatography (HPLC) than authentic nalmefene 3-O-glucuronide. Milligram quantities of the metabolite were subsequently isolated and subjected to fast atom bombardment (FAB) mass spectral and nuclear magnetic resonance (NMR) analyses. The conjugate was identified as nalmefene 3-O-beta-diglucuronide with a 1,2-beta linkage between the two glucuronic acids. It is unlikely that this novel form of conjugate is unique to nalmefene and it is probably a metabolite of other morphinans and/or similar drugs in the dog. Nalmefene 3-O-diglucuronide is not a metabolite of nalmefene in man.

Pharmacokinetics of a new inotropic catecholamine in dog plasma using solid phase extraction technology

The pharmacokinetics of a new inotropic catecholamine, N-[2-(3,4-dihydroxyphenyl)-ethyl]-1-methyl-3-(3-carbomylphenyl)-pr opylamine HCL (KM-13), was studied following i.v. injection of 50 and 100 micrograms/kg doses to dogs. KM-13 was extracted from plasma using Bond-Elut CN columns and quantitated by HPLC with electro-chemical detection. The plasma concentration--time profile of KM-13 following an i.v. bolus was best fitted with a bi-exponential equation and the terminal elimination phase had a half life of about 20 min. The analytical method, with a limit of sensitivity of 2 ng/ml, would appear to have general applicability in studying the pharmacokinetics of synthetic catecholamines.

Nalmefene: safety and kinetics after single and multiple oral doses of a new opioid antagonist

The aim of these two studies was to evaluate the safety and pharmacokinetics of oral nalmefene, a new orally effective opioid antagonist. In the first study, single ascending doses of 50, 100, 200, and 300 mg of nalmefene HCl were administered in double-blind fashion to four groups of healthy men. There were six subjects in each group; four received nalmefene and two received placebo. The drug was well tolerated at all dose levels with only mild and transient side effects, such as lightheadedness, at the higher doses. Model-independent pharmacokinetic analysis of the plasma concentration-time data showed that nalmefene was rapidly absorbed and had an elimination half-life that ranged from seven to 15 hours (mean, 10.7 hr). There was a good linear relationship (r = .97) between administered dose and total area under the curve at each dose level. Only about 4% of the dose was excreted in the urine as unchanged nalmefene, whereas up to 60% was excreted as a beta-glucuronidase/sulfatase hydrolysable conjugate(s) of nalmefene. In the second study, six healthy men were initially administered a single 50-mg dose of drug, and plasma samples were obtained at selected time intervals for 48 hours. A dosing schedule of 20 mg q12h was then started and continued for seven days. Plasma samples were collected immediately before each dose and at selected times for up to 48 hours after the last dose. The drug was well tolerated by all subjects, and no clinically significant adverse effects were observed during the seven-day administration period.(ABSTRACT TRUNCATED AT 250 WORDS)

Noninvasive delivery of a novel inotropic catecholamine: iontophoretic versus intravenous infusion in dogs

Using a newly developed iontophoretic delivery device, a novel inotropic catecholamine, pharmacologically similar to dobutamine, has been successfully administered to dogs by noninvasive transdermal infusion for periods of up to 1.5 h. The technique was compared with intravenous infusion and shown to be capable of achieving the same degree of cardiac contractility and steady-state plasma concentrations of the inotrope. There was also a good linear relationship between the applied current and the resulting steady-state plasma concentrations of the inotrope. Approximately 2 mA of applied current during transdermal iontophoresis produced a response equivalent to an intravenous infusion of 1 micrograms/kg/min of the drug.

Nalmefene: intravenous safety and kinetics of a new opioid antagonist

In a placebo-controlled, double-blind study we evaluated the safety and kinetics of a new narcotic antagonist, nalmefene, after 2, 6, 12, and 24 mg intravenous doses to healthy men. At each dose level four subjects received active drug and two received placebo. The drug was well tolerated at all dose levels with only mild and transient side effects, the most common of which was lightheadedness. The plasma concentration-time data were best fit with a triexponential equation, and the terminal elimination phase had a harmonic mean t1/2 of 8 to 9 hours. Only about 5% of the dose was excreted in the urine as intact nalmefene, with up to 60% excreted as nalmefene glucuronide. Although intersubject differences were noted, mean or dose-normalized mean kinetic parameters such as clearance, steady-state volume of distribution, terminal t1/2, and AUC showed no consistent trends related to increasing doses, indicating that nalmefene has linear pharmacokinetics.

Cardiotonic agents: a simple HPLC procedure for the quantitation of dobutamine and a new congener in plasma

A simple high performance-liquid chromatographic procedure employing electrochemical detection (LC-EC) has been developed for the quantitation of the cardiotonic agent dobutamine and a new pharmacologically active congener. The drugs were extracted from plasma by adsorption on to alumina, eluted from the adsorbent with dilute perchloric acid and the eluate subjected to LC-EC. The method had a limit of sensitivity of 1 ng/ml of plasma for each drug. The applicability of the LC-EC procedure was demonstrated by determining steady-state plasma concentration profiles of dobutamine and its congener in man and dog, respectively, following i.v. infusion of the drugs.

Nalmefene: radioimmunoassay for a new opioid antagonist

A specific radioimmunoassay (RIA) has been developed for the quantitation of a new opioid antagonist, nalmefene, in human plasma. The method employs a rabbit antiserum to an albumin conjugate of naltrexone-6-(O-carboxymethyl)oxime and [3H]naltrexone as the radioligand. Assay specificity was achieved by extraction of nalmefene from plasma at pH 9 into ether prior to RIA. The procedure has a limit of sensitivity of 0.2 ng/mL of nalmefene using a 0.5-mL sample of plasma for analysis. The intra- and interassay coefficients of variation did not exceed 5.6 and 11%, respectively. The specificity of the RIA was established by demonstrating excellent agreement (r = 0.99) with a less sensitive and more time consuming HPLC procedure in the analysis of clinical plasma samples. The use of the RIA for the pharmacokinetic evaluation of nalmefene is illustrated with plasma concentration profiles of the drug in humans following intravenous and oral administration.

Nalmefene: quantitation of a new narcotic antagonist in human plasma using high performance-liquid chromatography with electrochemical detection

A high performance-liquid chromatographic procedure employing electrochemical detection (LCEC) has been developed for the quantitation of a new narcotic antagonist, nalmefene, in human plasma. Following extraction of the plasma at pH9, the extract was chromatographed on a reverse-phase C18 column using naltrexone as an internal standard. An electrochemical detector equipped with a glassy carbon electrode monitored the elution of nalmefene and the internal standard. The method had a limit of sensitivity of 3 ng/ml of nalmefene using a 1 ml sample of plasma and the calibration curve was linear over a range of 3-200 ng/ml. The intra- and inter-assay coefficients of variation did not exceed 6 and 12% respectively over the entire range of the calibration curve. The LCEC method has been used to quantitate the plasma concentrations of nalmefene in man following oral administration of 64 mg of the drug. In one subject, a peak plasma concentration of 58 ng/ml occurred 2 hr after drug administration and declined to 5 ng/ml after 24 hr.

Distribution of membrane cholesterol of adrenal cortical cells after corticotropin stimulation

Membrane cholesterol in adrenal cortical cells is enriched in the plasma membrane. Stimulation of isolated adrenal cortical cells with corticotropin leads to the production of corticosterone. At high levels of corticotropin, cholesterol for corticosterone synthesis arises by hydrolysis of cellular cholesteryl ester, whereas at lower levels of corticotropin cholesteryl ester levels are unchanged from control values and there is a decrease in plasma-membrane cholesterol levels.