Hajime Arakaki

Abnormalities of auditory event-related potentials in schizophrenia prior to treatment.

BACKGROUND P300 amplitude reduction is a consistent finding in schizophrenic patients, but it is unclear if this abnormality predates neuroleptic treatment or is present at onset of illness. METHODS Auditory event-related potentials (ERPs), during a standard oddball paradigm, were recorded from 45 neuroleptic-naive schizophrenics, 56 drug-free, previously treated schizophrenics, and 73 healthy normal controls. Forty-seven of the schizophrenic subjects had their first episode within the past year. RESULTS N200 amplitude did not differ among groups. P300 amplitude was significantly smaller in both neuroleptic-naive and previously treated schizophrenic groups compared to the control groups. There were no significant differences between the two schizophrenic groups in P300 amplitude. N200 and P300 latency were prolonged in previously treated schizophrenics compared to neuroleptic-naive schizophrenics and normal controls. CONCLUSIONS The present study suggests that ERP abnormalities, especially P300 amplitude reduction, are already present prior to the administration of neuroleptic medication in the earliest stage of schizophrenia.

Clinical and epidemiological observations of cutaneous tuberculosis in Larkana, Pakistan.

Background Cutaneous tuberculosis is widespread in Pakistan but has not been fully documented. This study was conducted to determine the clinical pattern, nature and existence of the disease in Larkana, Sindh province, Pakistan.

N2 and P3b components of the event-related potential in students at risk for psychosis

The N2 and P3b components of event-related potentials (ERPs) were studied in students who were identified as being at high risk for psychosis on the basis of their scores on the Chapman Psychosis Proneness Scales (PPS). The Magical Ideation subscale (MIS), the Perceptual Aberration subscale (PABS), and the Social Anhedonia subscale (SAS) were administered to 2,022 undergraduate university students. To determine if there were any relationships between these psychometric instruments and electrophysiological measures, 40 high-risk students were compared with 40 age- and gender-matched control students using auditory ERPs obtained from three midline electrodes (Fz, Cz, Pz) in a standard oddball paradigm. N2 (rare stimuli) and N2b latencies were significantly longer in the high-risk than in the control subjects, and the high-risk group also evidenced significantly smaller amplitude of the P3b component. No significant correlations between scores on the PPS or its three subscales and the amplitudes or latencies of the P3b or N200 component were found. These findings suggest that the N2 and P3b ERP components might serve as trait markers for psychosis and that individuals psychometrically identified as being at high risk for psychosis have deficits in the maintenance of attention and in decision-making.

Prolactin concentrations during aripiprazole treatment in relation to sex, plasma drugs concentrations and genetic polymorphisms of dopamine D2 receptor and cytochrome P450 2D6 in Japanese patients with schizophrenia

The authors investigated the correlation between prolactin concentrations during aripiprazole treatment and various factors, including age, sex, plasma concentrations of aripiprazole and its active metabolite, dehydroaripiprazole, and genetic polymorphisms of dopamine D2 receptor (DRD2) and cytochrome P450(CYP)2D6.

Assessment of psychosocial stressors and maladjustment among foreign students of the University of the Ryukyus.

An extensive survey of problems encountered by foreign students of the University of the Ryukyus and the resulting levels of stress was carried out in order to determine the main stressors hindering academic progress and personal adjustment. Subjectively perceived stress levels after arrival in Japan were obtained from 134 subjects through a comprehensive questionnaire for reporting specific stressors. The 30‐item General Health Questionnaire (GHQ) was included to assess mental health state. Differences in scores by area of origin were also determined for the total GHQ scores and its sub‐scales. The GHQ results showed that regardless of length of time in Japan, more than 60% of the subjects scored within a range usually indicative of a mental health risk. Mean scores by area of origin showed a 50% reduction over time for non‐Chinese Asians and North American/Europeans, but only a reduction of 1.1% or less for Chinese, Latin American, Middle/Near Eastern and African subjects. Limitations in achievement of academic goals were reported by the greatest number of students as causing moderate to excessive stress (57.5%); most frequently reported causes were language inadequacy (55.2%), reference materials unavailable (34.3%), unfamiliarity with Japanese study methods (32.1%), and inadequate guidance from teachers/advisors (26.9%). Various social, personal and daily life problems in the non‐academic setting were also reported as causing high stress levels. Most of the stressors identified are not considered inevitable and point toward directions to pursue in preventive strategies in mitigating psychological distress and maladjustment of students.

Inhibitory Effects of Alpinia speciosa K. SCHUM on the Porphyrin Photooxidative Reaction

It is thought that the β‐carotene defense mechanism against photosensitivity involves the inhibition of singlet oxygen formation, a kind of active oxygen. When we screened chemical substances obtained from plants indigenous to Okinawa, known to have residents with the longest life span in Japan, we found that Alpinia speciosa K. SCHUM (Japanese name: gettou), which is used as a food preservative, has an activity similar to that of β‐carotene. We measured the amount of lipid peroxide (LPO) formed from a hematoporphyrin‐containing rat liver microsomal suspension irradiated with visible light. The inhibitory effect of Alpinia speciosa on LPO formation was confirmed when the addition of increasing concentrations of Alpinia speciosa extract led to a decrease in the amount of LPO formed. Moreover, the reaction mechanism that affects the amount of singlet oxygen formed was measured, and the effect of the extract was determined by the ESR trapping technique. It was found that the extract effectively inhibited the formation of singlet oxygen. The extract of Alpinia speciosa contains dihydro‐5,6‐dehydrokawain. It was confirmed that dihydro‐5,6‐dehydrokawain, which is a water‐soluble compound, has singlet oxygen quenching activity. We synthesized five derivatives of kawain and found that dimethyl [6‐(2‐phenylethyl)‐2‐oxo‐2H‐pyran‐4‐yl] phosphorothionate has the strongest singlet oxygen quenching activity. The use of the compound from Alpinia speciosa that exhibits singlet oxygen quenching activity as an inhibitory agent of the phototoxic reaction in porphyria is expected.

Deviate P200 and P300 in non-patient college students with high scores on the schizophrenia scale of the Minnesota Multiphasic Personality Inventory (MMPI)

Event-related potentials (ERPs) were examined in 16 college students who had high scores on the Schizophrenia Scale of the MMPI (HSS) but were without a hereditary disposition for major psychiatric disorders. 32 sex- and age-matched college students were used as controls. Subjects whose T scores were higher than 70 were designated the HSS subjects. ERPs were recorded during an auditory oddball task. Although neither the P300 latencies nor the P200 latencies differed between the two subject groups, the amplitudes of P300 to rare stimuli and P200 to frequent stimuli were lower in the HSS subjects than in the controls. These results suggest that deficits, both in the P300-related cognitive function to rare relevant stimuli, as well as matching and/or the comparison process for irrelevant frequent stimuli, may be present in HSS subjects. The HSS subjects, especially those with a combination of P300 and P200 deficits, even though without a hereditary diathesis for schizophrenia, may constitute one type of high-risk group.

13. Neuroimaging, structural414 - MRI and ERP abnormalities in first episode schizophrenia and affective psychosis

to 100, reflecting the percentage of the tissue component in every voxel. The study comprised 17 schizophrenic patients and 19 normal healthy volunteers. . Results:.Significantly decreased brain volumes were recorded III the schizophrenic patient group compared to controls. This decrease appeared to be due to white matter volume deficits. The grey/white ratio in schizophrenic patients was 1.31 as compared with I.l7 in the normal healthy volunteers (p<O.OOS). The findings could not be explained by difference in age, height, sex or abuse . Comment: The impairment of the white matter in schizophrenic patients may suggest a defect of the communicative ~o~nection system within the brain in this patient group. Th is ~s III CO?cert with recent findings of impaired fronto-temporal mt~ractlOn during the word fluency task in schizophrenic patients,