Molecular Dynamics of Amorphous Sulfamethazine With Structurally Related Sulfonamide Impurities Evaluated Using Thermal Analysis.

In this study, the effects of structurally related organic impurities on the molecular dynamics of amorphous sulfamethazine were evaluated using thermal analysis. Sulfanilamide (SNA), sulfamerazine (SMR), and sulfadimethoxine were used as virtual impurities of sulfamethazine. The amorphous state was prepared in situ in differential scanning calorimetry by quenching the melted physical mixtures of sulfamethazine and each impurity compound in the differential scanning calorimetry pan. In the following heating process, the glass transition temperatures (Tg) of each were measured. The fragility parameters were estimated from the width of Tg. The Tg of amorphous sulfamethazine with those impurities changed in accordance with the manner set forth in the Gordon-Taylor equation. The fragility parameter slightly increased when a small amount of SNA or SMR was incorporated. Moreover, the probability of a measurement in which crystallization of sulfamethazine was observed above its Tg, increased at a low-concentration range of SNA, SMR, or sulfadimethoxine. It was considered that the existence of a small amount of impurity would induce heterogeneity in the molecular density of the amorphous state, which would be associated with the local fluctuation. It was suggested that the change in the molecular dynamics would be related to the probability of crystallization of sulfamethazine.

The effect of structurally related impurities on crystallinity reduction of sulfamethazine by grinding.

In this study, the effect of structurally related impurities on crystallinity reduction of sulfamethazine by grinding was evaluated. The crystallinity of sulfamethazine was not decreased when it was ground alone. However, when structurally related impurities with sulfonamide derivatives were blended, the crystallinity of sulfamethazine was decreased by grinding. Other materials without a sulfonamide moiety showed no such effect. The Raman spectra of sulfamethazine demonstrated that there was a difference between its crystalline and amorphous states within its sulfonamide structure. It was suggested that the sulfonamide structure of the impurities was important in causing the inhibition of recrystallization of sulfamethazine during grinding.

Clear distinction between preattentive and attentive process in schizophrenia by visual search performance.

Visual information-processing deficits were investigated in patients with schizophrenia using visual search tasks. Subjects comprised 20 patients with schizophrenia and 20 normal subjects. Visual search tasks were modified from those used previously to reveal more distinct differences between feature and conjunction search tasks. The presentation area of items in the present study was more than double the area used in our previous study [Mori, S., Tanaka, G., Ayaka, Y., Michitsuji, S., Niwa, H., Uemura, M., Ohta, Y., 1996. Preattentive and focal attentional processes in schizophrenia: a visual search study. Schizophrenia Research 22, 69-76], and items were distributed over the area randomly in each trial to produce a certain range of locational jitter for each item across trials that prevented a matrix-like presentation of items at fixed positions [Mori, S., Tanaka, G., Ayaka, Y., Michitsuji, S., Niwa, H., Uemura, M., Ohta, Y., 1996. Preattentive and focal attentional processes in schizophrenia: a visual search study. Schizophrenia Research 22, 69-76]. The target was a red square, and distractors were red circles in the feature search task and red circles and green squares in the conjunction search task. Slopes and intercepts of a linear function relating reaction times to set size were computed. In the feature search task, slopes for both groups were almost zero. In the conjunction search task, significant differences in slopes were seen between the two groups irrespective of target presence or absence. Moreover, the slopes were approximately twice as steep during target absence as during target presence. These results indicate more definitively than the results of our previous study [Mori, S., Tanaka, G., Ayaka, Y., Michitsuji, S., Niwa, H., Uemura, M., Ohta, Y., 1996. Preattentive and focal attentional processes in schizophrenia: a visual search study. Schizophrenia Research 22, 69-76] that patients with schizophrenia have deficits in focal attentional processing, although their preattentive processing functions at a normal level.

[Epidemiological study of schizophrenia on the Island of Tsushima in Nagasaki Prefecture].

The epidemiology of schizophrenia has been studied with regard to the incidence, prevalence, and morbid risk, and there have been comprehensive reviews. However, the incidence and prevalence have not been analyzed simultaneously in many studies. In the present study, which was performed on a remote island, the number of patients could be determined, and they could be followed up by the same observer. This permitted us to conduct comprehensive epidemiological research while providing local mental health care. The subjects were patients diagnosed with schizophrenia according to the DSM-III-R in Tsushima, Nagasaki Prefecture, between April 1, 1988 and March 31, 1996. The incidence of schizophrenia was 2.3 (2.5 in males, 2.1 in females) per 10,000 people of the population, and the age-adjusted incidence was 2.4. Its prevalence was 5.8 (6.1 in males, 5.7 in females) per 1,000 people of the population, and the age adjusted prevalence was 6.2. In both sexes, the number of patients and the prevalence increased annually. The morbid risk was 0.95% (1. 01% in males, 0.89% in females) by the direct method (calculated from the incidence) and 0.85% (0.90% in males, 0.81% in females) by the indirect method (calculated from the prevalence), showing similarity. These incidence, prevalence, and morbid risk results did not markedly differ from the values reported to date. It is important to establish preventive measures for schizophrenia on the basis of the basic data obtained in this study, and to serially evaluate changes in epidemiological parameters of schizophrenia after their application. Furthermore, by comparing these epidemiological findings with those of other mental disorders and other regions, methods are expected to be utilized comprehensively for local mental health care.

Factors affecting the family support system of patients with schizophrenia: a survey in the remote island of Tsushima.

Possible support for home-cared schizophrenic patients and their families was investigated on Tsushima, one of the many isolated islands in Japan. The psychopathologic symptoms of the patients were evaluated using the Brief Psychiatric Rating Scales (BPRS), their social adjustment using the Psychiatric Disability Assessment Schedule (DAS), mental states of the families using the General Health Questionnaire (GHQ), and the quality of life (QOL) using the Life Satisfaction Rating Scales (LSR). The family support systems for the patients were evaluated with regard to: (i) family support for the patient's daily life (FS), (ii) hardships of family life caused by living with the patient (HF), and (iii) empathic attitude of the family toward the patient (EA). Psychotic symptoms of schizophrenic patients were closely related to the mental state and QOL of their families. Family support was significantly correlated with HF and EA. Moreover, the family support system was shown to be related both to the psychotic symptoms of the patient and the mental state of the family. These results suggest that an approach to improve the family support system for the patient may exert positive effects on the patient's psychotic symptoms and his/her social adjustment. We also consider that intervention by a public organization is necessary to improve the family support system on islands.