An association study between two missense variations of the benzodiazepine receptor (peripheral) gene and schizophrenia in a Japanese sample

The benzodiazepine receptor (peripheral) (BZRP) mainly localized on glial cells plays a role in neurosteroid synthesis, and increases with glial proliferation. We have recently reported a significant decrease in the density of BZRP labeled by [3H] PK 11195 in the postmortem brain of chronic schizophrenics, suggesting that dysfunctions of the BZRP are involved in the pathophysiology of schizophrenia. We screened 11 patients with schizophrenia and 10 controls, which were used in a previous postmortem study, for their genomic sequences of the BZRP gene in order to find DNA sequence variations. One novel missense polymorphism (His162Arg) and another previously reported missense mutation (Ala147Thr) were detected. An association study of the identified variations was then performed in an extended Japanese sample of 304 schizophrenic patients and 369 controls. While there was an increased tendency in the frequency of the 162Arg allele of schizophrenics compared to that of the controls (p = 0.0603), no statistically significant association with schizophrenia was observed in the Ala147Thr allele (p = 0.1016). These results do not suggest that the two missense polymorphisms play a major role in the genetic predisposition of schizophrenia in the Japanese sample.

In vitro and in vivo studies of a bone morphogenetic protein-2 expressing adenoviral vector

BACKGROUND

Bone morphogenetic proteins (BMPs) play important roles in the migration of osteoblast progenitor cells, the proliferation of mesenchymal cells, and their differentiation into chondrogenic and osteogenic cells. However, the optimum procedure to deliver BMPs remains unknown. To examine the effectiveness of a gene transfer procedure for the delivery of BMP-2, we constructed a human BMP-2-expressing replication-deficient adenoviral vector, AxCAOBMP-2, and evaluated its osteoinductive activity in vitro and in vivo.

METHODS

C2C12 myoblasts were infected in vitro with this viral vector or an Escherichia coli LacZ gene-expressing control adenovirus vector (AxCALacZ). Twenty-four hours after the infection, indirect immunofluorescence was performed. On day 5 after the infection, alkaline phosphatase (ALP) in the cells and osteocalcin in the culture medium were measured. Furthermore, to examine the effectiveness of gene transfer of BMP-2 in vivo, we evaluated osteoinduction by AxCAOBMP-2, under transient immunosuppression with cyclophosphamide, given at a dose of 125 mg/kg intraperitoneally the day before injection of the adenoviral vector. Twenty-five microliters of AxCAOBMP-2 (8.75 x 10(8) plaque-forming units [pfu], Group I) and AxCALacZ (1.75 x 10(8) pfu, control group) and 5 microl of AxCAOBMP-2 (1.75 x 10(8) pfu, Group II) were injected into a right calf muscle of Wistar rats. On day 21, bone formation in each group was investigated radiologically and histologically.

RESULTS

Abundant BMP-2 expression in C2C12 cells infected with this viral vector was confirmed by immunofluorescence. C2C12 cells transferred with the BMP-2 gene by this vector produced ALP in the cells and also produced and secreted osteocalcin in the culture medium. Osteoinduction was found only in the AxCAOBMP-2 treated groups with immunosuppression. Osteoinduction activity was higher in Group I than in Group II.

CONCLUSION

This study demonstrated the osteoinductive activity in vitro and in vivo by an adenoviral vector carrying the BMP-2 gene.

CLINICAL RELEVANCE

Gene therapy with AxCAOBMP-2 under transient immunosuppression may be useful for bone reconstruction.

Dopamine D2 receptors in the insular cortex and the personality trait of novelty seeking

Human personality has been considered to have a neurochemical background. We examined the relation between extrastriatal dopamine D2 receptor binding in living human brain and the personality trait of novelty seeking that has been proposed to be related to dopaminergic function in the brain. We measured extrastriatal dopamine D2 receptors of 24 healthy young male subjects using [(11)C]FLB 457 positron emission tomography. The personality trait of each subject was assessed by the Temperament and Character Inventory (TCI). Correlation of dopamine D2 receptor binding with novelty seeking was calculated using region-of-interest analysis and statistical parametric mapping based on the binding potential images generated using a reference tissue model. A significant negative correlation was observed between binding potential values and the novelty seeking scores on TCI in the right insular cortex. No significant correlation was observed in any other region. Our result indicates that there is a significant association between dopamine D2 receptor binding and the human novelty seeking trait in the right insular cortex.

Association between cadmium concentration in rice and mortality in the Jinzu River basin, Japan

A follow-up survey on 2101 inhabitants (1566 men, 535 women), who participated in a 1967 health survey and had resided in their present rural community since birth was conducted to determine the influence of environmental cadmium exposure on the mortality of the general population in the Jinzu River basin. The survey was conducted over 6128 days from August 1, 1967 to May 10, 1984. The rural communities were divided into two groups, one with a cadmium concentration in rice of < 0.30 ppm and the other > or = 0.30 ppm. The influence of cadmium concentration in rice on mortality was analyzed using SMRs and a Cox's proportional hazards model. In both sexes, SMRs tended to be greater in the > or = 0.3 ppm group as compared to < 0.3 ppm group. The Cox hazard ratios for males and females in the > or = 0.30 ppm group, to those in the < 0.30 ppm group, were 1.42 and 1.10, respectively (significant in the men). Since the mean cadmium concentration in rice in each rural community was closely related to the development of renal injury, in regions with high cadmium concentrations in rice, the development of renal injury induced by cadmium is believed to be the factor underlying the increased mortality observed.

A retrospective study on the relation between renal dysfunction and cadmium concentration in rice in individual hamlets in the Jinzu River basin, Toyama Prefecture, Japan

Using as an index of exposure the Cd concentration in rice and as an index of health effect the urinary abnormality rate (proteinuria, glycosuria, and proteinuria with glycosuria) in the most systematic and extensive health screening examination conducted in 1967 and 1968 in the Jinzu River basin, Japan (a total of 13,183 subjects), we investigated whether a dose-response relationship exists between the two indices. For subjects that lived in the same hamlet since birth, with low Cd concentrations in rice it was confirmed that renal dysfunction does not develop unless the length of residence is prolonged, whereas with high Cd concentrations in rice renal dysfunction develops even when the length of residence is short. For subjects that lived in the same hamlet for over 30 years and that were aged over 50 years, the urinary abnormality rate in individual hamlets showed significant increases with increases in the mean Cd concentration in rice, demonstrating that a dose-response relationship existed. The allowable values of Cd concentration in rice were estimated to be in the range of 0.05-0.20 ppm, representing values lower than the 0.4 ppm provisionally adopted by the Japanese government.

KT3-671, an angiotensin AT1 receptor antagonist, attenuates vascular but not cardiac responses to sympathetic nerve stimulation in pithed rats

Effects of KT3-671 on vascular and cardiac sympathetic neurotransmission were investigated in pithed rats. The pressor response to spinal stimulation (5 Hz) of the pithed rat without the adrenals was approximately 75% of that with the adrenals. Guanethidine (8 mg/kg, i.v.) decreased by about 76% the pressor response to sympathetic stimulation in the pithed rat with intact adrenals and the guanethidine-resistant response was almost completely abolished by bilateral adrenalectomy. Therefore, the following experiments were done using the pithed rat without the adrenals. KT3-671 (1-10 mg/kg, i.v.) as well as losartan (1-10 mg/kg, i.v.) inhibited dose-dependently the pressor response to sympathetic stimulation. KT3-671 was approximately four times more potent than losartan in inhibiting the pressor response. The two angiotensin II subtype 1 receptor antagonists (10 mg/kg, i.v.) did not affect the pressor response to exogenously administered norepinephrine. Neither KT3-671 nor losartan influenced the tachycardia induced by spinal stimulation and isoprenaline. Intravenous infusion of angiotensin II (100 ng/kg/min) did not affect both pressor and tachycardic responses to sympathetic stimulation. In conclusion, KT3-671 as well as losartan inhibits vascular but not cardiac sympathetic neurotransmission of the pithed rats, which may contribute to its overall antihypertensive efficacy.

Effect of hyperbaric oxygenation on bone induced by recombinant human bone morphogenetic protein-2

We examined the effect of hyperbaric oxygen (HBO) therapy on the osteoinductive activity of recombinant human bone morphogenetic protein-2 (rhBMP-2), 5mg of which was implanted into the calf muscle of rats using atelopeptide type I collagen as a carrier. Thirty Wistar rats were divided equally to be given HBO or act as controls. New bone formation was measured radiographically, biochemically, and histol ogically 3, 7, and 21 days after implantation. In both groups, new bone formation was found on day 21. However, there was significantly more new bone in the HBO group. In the HBO group, cartilage was present at the outer edge of the implanted material on day 7. On days 7 and 21, the local tissue alkaline phosphatase activity and calcium content in the HBO group were significantly greater than in the control group. These results suggest that HBO accelerated the activity and rate of osteoinduction by rhBM P-2.

Alcohol consumption and blood pressure in Japanese men

In a study of Japanese men, a nonlinear association of alcohol consumption and blood pressure was not observed. This cross-sectional study was conducted to clarify the effect of infrequent or light alcohol consumption on blood pressure in normotensive Japanese men. The subjects were 2,179 male workers ranging in age from 40 to 54 years. Drinking habits were represented by three indices: episodic alcohol consumption, frequency of drinking, and monthly alcohol consumption. Seven items were analyzed as covariates: age, body mass index, salt intake, physical activity, and levels of gamma-glutamyl transpeptidase, uric acid, and plasma glucose. The association between drinking habits and blood pressure was evaluated by using analysis of covariance. Both episodic alcohol consumption and frequency of drinking were significantly associated with blood pressure in subjects aged 45 to 54 years. In those aged 40 to 44 years, there was a significant association between frequency of drinking and diastolic blood pressure. Significant associations of monthly alcohol consumption with blood pressure in every age group also were found. In subjects aged 45 to 54 years, linear associations between episodic alcohol consumption, frequency of drinking, monthly alcohol consumption, and adjusted blood pressure were observed. In those aged 40 to 44 years, nonlinear associations of monthly alcohol consumption and frequency of drinking with adjusted blood pressure were observed, and threshold effects of 540 ml of alcohol per month and a frequency of 1 to 12 days per month were found. In conclusion, habitual alcohol consumption increases blood pressure linearly in normotensive workers aged 45 to 54 years, although light consumption does not affect blood pressure in those aged 40 to 44 years.

Relation among dopamine D(2) receptor binding, obesity and personality in normal human subjects

Personality is a behavioral pattern, which differs among individuals. Kretschmer (Kretschmer, E., Physique and Character: an Investigation of the Nature of Constitution and the Theory of Temperament, New York, 1921) categorized personality variants according to the concept of fundamental body types. Recently, several lines of evidence suggest that the central dopamine system may underlie the regulation of weight and the personality trait. In this study, we examined the dopamine D2 receptor (D2R) binding using positron emission tomography with [11C]FLB 457 [(s)-N-[(1-ethyl-2-pyrrolidinyl) methyl]-5-bromo-2,3-dimethyloxybenzamide] together with body mass index (BMI) and personality trait on the temperament and character inventory (TCI) in 16 normal subjects. Our data demonstrate that there was a significant relation among D2R binding in the amygdala, BMI and personality trait of harm avoidance. It can be assumed that variation of dopaminergic activity in the amygdala underlies the personality variants related to the concept of fundamental body type.

[Analysis of clinical costs for inpatients with the urologic diseases in 1997]

OBJECTIVES

Because of recent increases in health care costs, reformation care cost system similar to the disease related group/prospective payment system (DRG/PPS) was attracted attention in Japan. We analyzed the costs for inpatients with urologic diseases in our institution and compared them with the costs reported in Japanese trials of DRG/PPS.

MATERIALS & METHODS

Subject consisted of 363 consecutive urologic diseases inpatients treated in our hospital in the period between April 1 1997 and March 31 1998. Of these 107 had bladder tumor, 79 BPH (benign prostatic hyperplasia), 34 prostate tumor, 32 renal tumor, 17 in urinary stone (excluding cases with bladder stones) and 94 cases in others. The total hospital charge for each case was calculated, and the averages and standard deviations for each disease were analyzed. We analyzed the relationship between hospital charges for each disease, and complications, the degree of disease, age and length of stay (LOS). Health care costs are assessed in unit, each of which is the equivalent of 10 yen.

RESULTS

The average of total hospital charges was 108,841.6 points for bladder tumor, 61,692.2 points for BPH, 96,825.3 points for prostate tumor, 188,459.0 points for renal tumor, and 66,052.2 points for urinary stones. The standard deviation was 99,611.3 points for bladder tumors, 16,712.9 points for BPH, 65,419.3 points for prostate tumor, 204,389.6 points for renal tumor and 30,081.7 points for urinary stone. There was a positive correlation between hospital charge and LOS in most diseases. The average hospital charges for each disease were much higher than the reimbursement charges of the trial Japanese DRG/PPS.

DISCUSSION

Shortening of LOS using established clinical pathways reduces health care costs. However, in Japan, the wide range of preliminary results suggests that it may be too early to introduce the DRG/PPS system for health care cost. Furthermore nationwide investigations are needed before the introduction of the DRG/PPS system into Japanese health care reimbursement system.

Error analysis for quantification of [(11)C]FLB 457 binding to extrastriatal D(2) dopamine receptors in the human brain

To estimate receptor binding of ligand by positron emission tomography (PET) without an arterial input function, several quantitative approaches based on the use of a reference region have been proposed. We compared three approaches for quantifying extrastriatal D(2) dopamine receptors using [(11)C]FLB 457. The PET measurements were performed on seven healthy men. Binding potential (BP) of [(11)C]FLB 457 was calculated by the reference tissue model method, transient equilibrium method, and late time method. The reference tissue model describes the time-activity curve in a brain region in terms of that in the reference region, assuming that the levels of nondisplaceable radioligand binding in both regions are the same. The transient equilibrium theoretically occurs when the derivative for specific binding is zero. With the late time method, BP is calculated by integrating a late part of the time-activity curve. BP values obtained by all methods were in good agreement with those obtained by the kinetic approach, and the highest coefficient of correlation was observed in the reference tissue model method. In the simulation study, the error of BP calculated by the reference tissue model method was smallest. Moreover, the effect of the difference in the influx rate constant K(1) between the brain and the reference regions on BP was nearly avoided as theoretically predicted. We concluded that the reference tissue model method is most suitable for calculating BP of extrastriatal D(2) dopamine receptors with [(11)C]FLB 457.

Evidence for association of the myo-inositol monophosphatase 2 (IMPA2) gene with schizophrenia in Japanese samples

In our search for candidate genes for affective disorder on the short arm of chromosome 18, we cloned IMPA2, a previously unreported myo-inositol monophosphatase gene, that maps to 18p11.2. We determined its genomic structure and detected three new single nucleotide polymorphisms (SNPs). In the present study, we screened the gene further to search for additional polymorphisms in Japanese samples and identified seven other SNPs, including a novel missense mutation. These polymorphisms clustered into three regions of the gene. Three relatively informative SNPs, 58G>A, IVS1--15G>A and 800C>T from clusters 1, 2 and 3, respectively, were selected for association tests using a case-control design. The Japanese cohort included 302 schizophrenics, 205 patients with affective disorder and 308 controls. Genotyping was done either by melting curve analysis on the LightCycler or by sequencing. All three SNPs showed significant genotypic association (nominal P = 0.031--0.0001) with schizophrenia, but not with affective disorder. These findings increase the relevance of 18p11.2 to schizophrenia susceptibility because GNAL, which has been shown previously to be implicated in schizophrenia in an independent study, is in close physical proximity to IMPA2. Our findings suggest that IMPA2 or a gene nearby may contribute to the overall genetic risk for schizophrenia among Japanese.

Cortical oscillations in human medial temporal lobe during wakefulness and all-night sleep

We have recorded human medial temporal lobe electrocorticogram during wakefulness and natural sleep in epileptic patients with subdural electrodes. From these recordings, we have found gamma (30-150 Hz) [Neuroscience 90 (1999) 1149] and beta-1 (10-20 Hz) [NeuroReport 10 (1999) 3055] activities during wakefulness in human medial temporal lobe. In this paper, we will report changes of these frequencies across wake and natural sleep. Electrocorticograms during wake, slow wave sleep and rapid eye movement (REM) sleep were subjected to fast Fourier transformation analysis. During wake two spectral enhancements, beta-1 and gamma, were consistently observed across subjects. In the raw signal, beta-1 was observed as a regular rhythmic oscillation. In slow wave sleep, the beta-1 peak disappeared but gamma remained, although slightly reduced in power. During REM sleep, beta-1 appeared again, but the peak frequency was significantly lower than during wake (mean frequency: wake=16.6, REM=12.8 Hz). The gamma peak was also present in REM sleep. It has been known that the rhythmic slow activity (RSA) or theta is observed in some animals. However, it is unclear whether the human hippocampus displays similar activity. Since human beta-1 appears during wake and REM sleep when RSA is observed in other species, and since beta-1 is also a regular rhythmic oscillation, we propose that beta-1 may be the functional equivalent of hippocampal RSA (theta) observed in some animals. Functional significances of the gamma activity should be further investigated.

Absence of sleep spindles in human medial and basal temporal lobes

All-night recordings from subdural electrocorticographic (ECoG) electrodes on the human medial and basal temporal lobes were analysed to examine spindling activities during sleep. Subjects were three males and three females who were candidates for neurosurgical treatments of partial epilepsy. Subdural electrodes were attached to the medial and basal temporal lobe cortices, allowing ECoG and electroencephalogram from the scalp vertex (Cz EEG) to be recorded simultaneously during all night sleep. In one case, subdural electrodes were attached also on the parietal lobe. Fast Fourier transformation (FFT) analyses were performed on the ECoG and Cz EEG signals. No organized sleep spindles or sigma band (12-16 Hz) peaks in FFT power spectra were observed from the medial or basal temporal lobes of the non-epileptogenic hemispheres during non-rapid eye movement (NREM) sleep. In a case with parietal electrodes, organized spindle bursts were observed in parietal signals synchronized with Cz spindles. Although delta band (0.3-3 Hz) power from both the medial and basal temporal lobes fluctuated across each night as expected, sigma activity changed little. However, 14 Hz oscillatory bursts were observed in the medial basal temporal lobe of epileptogenic hemisphere in two cases and bilaterally in one case during not only NREM sleep but rapid eye movement (REM) sleep and wakefulness. From the present study we conclude that sleep spindle activities are absent in the medial and basal temporal lobes. Fourteen Hz oscillatory bursts observed from the medial or basal temporal lobe in some cases were not considered to be sleep spindles since they also appeared during REM sleep and wakefulness. These waveforms could have originated due to epileptic pathology, since they frequently appeared in epileptic regions.

Ten year progressive ventricular enlargement in schizophrenia: an MRI morphometrical study

Recent studies of the brain using magnetic resonance imaging (MRI) have suggested progressive structural changes in schizophrenics. However, those studies were conducted over periods of less than 5 years and thus lacked sufficient capacity to determine the course and nature of this process. In this study, MRI scans were obtained in 15 schizophrenics and 12 controls at baseline and after 4- and 10-year follow ups. Volumes of the lateral ventricles were measured. Patients were assessed by the Brief Psychiatric Rating Scale (BPRS) at the same two time points: at baseline and at 10-year follow up. After 10 years, a significant lateral ventricular enlargement was found in patients (mean percentage change: +22.9%) but not in controls (5.1%). Although our results are not in disagreement with the neurodevelopmental hypothesis, they do provide strong evidence that in schizophrenia progressive brain reduction occurs even in its chronic stage.

Dose relationship of limbic-cortical D2-dopamine receptor occupancy with risperidone

RATIONALE

It has been suggested that the antipsychotic effect of antipsychotics is mediated by the antagonism of the dopamine D2 receptor in the limbic-cortical regions. Risperidone has an atypical property, but its effect on limbic-cortical regions has not been evaluated.

OBJECTIVES

In this study, we examined the relationship among doses of risperidone and limbic-cortical dopamine D2 receptor occupancy using positron emission tomography.

METHODS

Seven patients with schizophrenia were scanned during the steady state with risperidone. Their occupancies in limbic-cortical regions were determined using positron emission tomography with [11C]FLB 457.

RESULTS

The average occupancy ranged from 38% to 80% on doses of 1-6 mg/day. The saturation curve plotted against the drug level fit the data well.

CONCLUSIONS

Our results demonstrate that the D2 receptor occupancy with risperidone in the limbic-cortical regions seems to be similar to that of previous reports regarding the striatum, and it would be comparable to that of typical antipsychotics.

Application of path analysis to urinary findings of cadmium-induced renal dysfunction

In order to identify some causal relations among various urinary indices of cadmium-induced renal dysfunction, such as glucose, total protein, amino nitrogen, beta 2-microglobulin (beta 2-m), metallothionein (MT), and cadmium (Cd), we applied path analysis method to previous epidemiological studies targeting the residents of the Cd-polluted Kakehashi River basin of Ishikawa Prefecture, Japan. We obtained a diagram-termed path model, representing some causal relations among the above urinary indices. It shows that urinary Cd is located at the beginning point in the diagram, and Cd-induced renal dysfunction develops in the following order: Cd exposure-->increase of beta 2-m and/or MT excretion-->increase of amino-N and/or total protein excretion-->increase of glucose excretion. It was proved mathematically, that in the case of both males and females, increased excretions of beta 2-m and/or MT were the most sensitive urinary indices of the early stage of chronic Cd-induced renal dysfunction.

Reduced volume of the cerebellar vermis in neuroleptic-naive schizophrenia

BACKGROUND

Neuroimaging studies have suggested the possible role of the cerebellum in the pathophysiology of schizophrenia. However, no study has investigated the detailed structures of the cerebellum in patients without a history of neuroleptic medication. The objective of this study is to examine the volume of detailed structures of the cerebellum in neuroleptic-naive schizophrenic patients and to examine the relationship between cerebellar morphology and clinical symptoms.

METHODS

Magnetic resonance imaging scans were acquired from 20 male neuroleptic-naive schizophrenic patients and 20 healthy control subjects. We measured the volumes of the cerebrum, cerebellar hemisphere, cerebellar gray and white matter, and vermis. Symptoms were assessed with the Brief Psychiatric Rating Scale. Total Brief Psychiatric Rating Scale scores and subscale scores were used for analysis.

RESULTS

The volume of the vermis was significantly reduced in the schizophrenic group relative to the control group, whereas no significant differences were found in the volumes of other cerebellar structures and the cerebrum. Reduction in the vermal volume correlated with the total Brief Psychiatric Rating Scale Depression subscore and Paranoia subscore.

CONCLUSIONS

This study indicates that the volume of the vermis is reduced in patients with schizophrenia, and reduction in vermal volume is suggested to be related to the pathophysiology of the disease.

Effect of midodrine on chlorpromazine-induced orthostatic hypotension in rabbits: comparison with amezinium, etilefrine and droxidopa

Orthostatic hypotension was produced in urethane-anesthetized rabbit by a combination of chlorpromazine (0.1 mg/kg, i.v.) and 45 degrees head-up tilt. The effect of midodrine (1 and 3 mg/kg, i.d.) was investigated in comparison with amezinium (10 and 30 mg/kg, i.d.), etilefrine (10 and 30 mg/kg, i.d.) and droxidopa (30 and 100 mg/kg, i.d.). The higher doses of each drug significantly mitigated the chlorpromazine-induced orthostatic hypotension, while none of the lower doses caused a significant effect. The effect of midodrine developed most rapidly; a significant effect was observed 25 min after administration. The order of onset time was midodrine < etilefrine < amezinium < droxidopa. The effect of droxidopa was significant only at 130 to 160 min after administration. The amplitude of effect was in the following order; midodrine = droxidopa > or = etilefrine > amezinium. Midodrine (3 mg/kg, i.d.) mitigated orthostatic hypotension induced by prazosin (0.1 mg/kg, i.v.), but not by pentolinium (0.6 mg/kg, i.v.). It is suggested that midodrine competes with chlorpromazine at alpha1-adrenoceptors and subsequently recovers reflex vasoconstriction. Midodrine may be useful to protect patients with impaired baroreflex activity from accidental orthostatic hypotension during treatment with neuroleptics.

Bone induction by Escherichia coli -derived recombinant human bone morphogenetic protein-2 compared with Chinese hamster ovary cell-derived recombinant human bone morphogenetic protein-2

Most recombinant human bone morphogenetic protein (rhBMP) is currently obtained from Chinese hamster ovary (CHO) cells. If rhBMP with more activity could be derived from Escherichia coli (E. coli), a large quantity of rhBMP could be produced at low cost. The bone-inducing ability of an E. coli -derived rhBMP-2 (ErhBMP-2) variant with an N-terminal sequence was examined and compared with CHO cell-derived rhBMP-2 (CrhBMP-2). Two, 10, or 50 microgram of ErhBMP-2 or CrhBMP-2 was mixed with 3mg of atelopeptide type I collagen as the carrier, and specimens were implanted into the calf muscle pouches of Wistar rats (n= 5 in each group). Three weeks later, new bone had formed in all the ErhBMP-2-implanted and CrhBMP-2-implanted muscles. Radiographic and histological examinations showed that the bone induced by ErhBMP-2 had a large hollow bone matrix with more fatty marrow than the bone induced by CrhBMP-2. Quantitative analysis indicated that the activity of ErhBMP-2 was similar to that of CrhBMP-2, so ErhBMP-2 may be useful for inducing bone formation.

High catalytic activity of alanine racemase from psychrophilic Bacillus psychrosaccharolyticus at high temperatures in the presence of pyridoxal 5'-phosphate

We examined the effect of the pyridoxal 5'-phosphate (PLP) cofactor on the activity and stability of the psychrophilic alanine racemase, having a high catalytic activity at low temperature, from Bacillus psychrosaccharolyticus at high temperatures. The decrease in the enzyme activity at incubation temperatures over 40 degrees C was consistent with the decrease in the amount of bound PLP. Unfolding of the enzyme at temperatures above 40 degrees C was suppressed in the presence of PLP. In the presence of 0.125 mM PLP, the specific activity of the psychrophilic enzyme was higher than that of a thermophilic alanine racemase, having a high catalytic activity at high temperature, from Bacillus stearothermophilus even at 60 degrees C.

Predictive variables of interictal psychosis in epilepsy

OBJECTIVE

To evaluate which variables predict interictal psychosis in epilepsy.

METHODS

The authors reviewed the biological backgrounds, clinical characteristics, and EEG findings in 246 patients with epilepsy and interictal psychosis and in 658 control patients with epilepsy and no psychotic history. With a logistic regression approach, the significance of each variable for the development of interictal psychosis was evaluated.

RESULTS

There are significant differences in family history of psychosis, age at onset of epilepsy, type of epilepsy, lateralization of epileptiform discharges, and level of intelligence between patients with interictal psychosis and those without it. Subsequent logistic regression analysis with all variables demonstrated that family history of psychosis, age at onset of epilepsy, type of seizures, and level of intelligence significantly correlated with psychosis.

CONCLUSIONS

A family history of psychosis, earlier age at onset of epilepsy, complex partial seizures or generalized tonic clonic seizures, and borderline intellectual functioning were the most important predictors for development of interictal psychosis.

A case of dermatomyositis associated with mechanic's hand

A 67-year-old man was referred to the Department of Internal Medicine at Tokyo Medical University with interstitial pneumonia in July 1999. He presented with keratotic plaques on both palsm and on the ventral and lateral sides of his fingers. Erythematous keratosis was observed on the dosal aspect of his fingers and metatarsophalangeal (MP) joints. Edematous erythema was seen on the patient's chest, back, and the extensor surfaces of his arms. Electromyography revealed a myogenic pattern and an increased level of myogenic enzymes was found in the blood. Histological findings of the ventral sides of his fingers showed hyperkeratosis and parakeratosis of the dermal tissue and liquefaction degeneration of the basal layer at the papilla. Based on these findings, the patient was given a diagnosis of dermatomyositis associated with mechanic's hand. A systemic examination confirmed interstitial pneumonia and carcinoma of the duodenal papilla. Mechanic's hand is a type of dermatitis associated with myopathy first reported by Stahl et al. in patients with collagen disease. We report herein the first documented case of mechanic's hand in Asians.