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Satoshi Kato

Publications and source records attributed to Satoshi Kato.

At least 19 recordsLinked to original sources

Analysis of the human APC mutation spectrum in a saccharomyces cerevisiae strain with a mismatch repair defect.

Somatic APC mutations in colorectal tumors with an RER phenotype reflect excessive frameshift mutations, especially in simple repetition tracts within the coding sequence. Because this type of mutation is characteristic of cells with a deficient DNA MMR system, the APC mutation signature of RER tumors may be attributable to a defect in the MMR system. However, there is little experimental evidence to prove that the spectrum of mutations and the APC gene distribution are directly influenced by MMR system defects. We therefore examined the mutation spectrum of the MCR of the APC gene after transfection into both MMR-proficient and MMR-deficient yeast strains and compared it with a previously reported human APC mutation database. Small insertions or deletions in mono- or dinucleotide repeats were more common in the MMR-deficient than in the MMR-proficient strain (91.2% vs. 38.1%, Fisher's exact test p < 0.0001). Furthermore, the 2 mutation hot spots, 4385-4394(AG)(5) and 4661-4666(A)(6), found in the yeast system corresponded with those in human tumors. Combining our data with those from human tumors, there appears to be hypermutable mutations in specific simple repetitive sequences within the MCR, which are more prevalent in MMR-deficient cells and RER tumors than in MMR-proficient cells and non-RER tumors. We therefore consider that the differences in the spectra of RER and non-RER tumors are attributable at least in part to the MMR system of the host cells.

Adenomatous Polyposis Coli Protein↗

Diazepam and chlormethiazole attenuate the development of hyperthermia in an animal model of the serotonin syndrome.

The serotonin (5-HT) syndrome is the most serious toxic interaction of antidepressants, but no pharmacotherapy has yet been established. In the present study, we created an animal model of the 5-HT syndrome by intraperitoneally injecting rats with clorgyline (2 mg/kg) and 5-hydroxy-L-tryptophan (5-HTP) (100 mg/kg) and evaluated the effectiveness of potent 5-HT(2A) receptor antagonists and GABA-enhancing drugs, including diazepam and chlormethiazole. The rectal temperature of the rats was measured, and the noradrenaline (NA) and 5-HT levels in the anterior hypothalamus were measured by microdialysis. In the group pre-treated with saline, the rectal temperature increased to more than 40 degrees C, and all of the animals died within 90 min after administration. Pre-treatment with potent 5-HT(2A) receptor antagonists prevented the development of hyperthermia and death in the rats. Pre-treatment with diazepam, 10 and 20mg/kg, and chlormethiazole, 50 and 100mg/kg, attenuated the development of hyperthermia. Although neither of these drugs completely prevented the rats from dying, they prolonged their survival time. Regardless of the type of therapeutic agents, the concentration of 5-HT increased to about 1100-fold the pre-administration level. The NA levels in the saline group increased to about 16-fold the pre-administration levels, but the increase was significantly lower in the rats that survived as a result of drug therapy. These results suggest that GABA-mimetic drugs may be effective against the 5-HT syndrome, although they have a somewhat weaker effect than the potent 5-HT(2A) receptor blockers, and that not only is 5-HT activity increased in the brain in the 5-HT syndrome, but the NA system is also enhanced.

5-Hydroxytryptophan↗

[Mental disorders among Japanese-Brazilians in Japan: relationships to pre-migration and acculturative factors].

The current population of Japanese-Brazilians living in Japan consists mainly of second- and third-generation Japanese immigrants to Brazil. In the last 10 years, they have migrated to Japan, their ancestral country, mostly as industrial workers. The objective of this study was to examine possible relationships between mental disorders and both pre-migration psychosocial factors and acculturative status, among Japanese-Brazilians in Japan. We developed our own Portuguese acculturation-questionnaire to assess the their adaptation to Japanese society and their ethnic-cultural identity. Using the acculturation-questionnaire, the Portuguese version of the self-reporting questionnaire (SRQ-20) and an identification form with socio-demographic and clinical data, a community sample of 131 Japanese-Brazilian immigrants in Utsunomiya and outpatient sample of 32 Japanese-Brazilians in the psychiatric department of a medical school in the same region were compared. Analysis was done by chi 2 Fisher and multiple logistic regression. The socio-demographic data indicated that the outpatients were most likely to have past medical history (OR = 12.3), traumatic experience (OR = 10.1) in Brazil before immigration, short duration of residence in Japan (OR = 3.76), no occupation in Brazil (OR = 4.78) and to be living alone in Japan (OR = 5.71). The findings from the acculturation-questionnaire showed that outpatients were most likely to have sociability in Japan with either Brazilians or Japanese only (OR = 3.94) and to hope to hand down either Brazilian or Japanese culture only to their posterity (OR = 5.31). The findings from the acculturation-questionnaire showed that the community sample showed a higher acceptance of both the Brazilian and Japanese culture than the patient sample. We suggested that mentally healthy individuals have a stronger integration orientation as an adaptation modes i.e. to keep the original ethnic-cultural identity on one hand, and to accept the cultural values, attitudes, norms and customs of the host society on the other, than individuals predisposed to- or with mental disorders among Japanese Brazilians in Japan.

Acculturation↗

Retinopathy in older patients with diabetes mellitus.

PURPOSE: We studied the effects of the age and/or disease duration in diabetics on the progression of diabetic retinopathy (DR). METHODS: The population consisted of 3614 type 2 diabetes mellitus (DM) patients. The subjects were divided into three age groups (elderly, > or = 65 years old; middle-aged, 64-40 years old, and younger < 40 years old) for disease duration-adjusted comparison with and without DR and proliferative diabetic retinopathy (PDR). Then, in 503 patients with 8-year follow-up data available, the frequency of development/progression of DR and the rate of progression to PDR were compared among the three groups. Thirdly, in the elderly patients, DR prevalence and the frequency of the development/progression of DR were compared between two groups with different diabetes duration (> or = 6 years and < or = 5 years). RESULTS: The prevalence of DR increased significantly with age (P < 0.001). The prevalence of PDR decreased significantly with age (P < 0.001). The overall frequency of the development and/or progression of DR increased significantly with age (P = 0.002); however, age was not related to the frequency of progression to PDR. In the patients with diabetes duration of 6-15 years, the frequency of the development/progression of DR and of progression to PDR after an 8-year follow up tended to decrease with age. Elderly patients with a diabetes duration of > or = 6 years showed significantly higher rate of prevalence of DR and frequency of development/progression of DR in an 8-year period than those with diabetes of a shorter duration (P < 0.001 and P < 0.001, respectively). CONCLUSION: In elderly DM patients, the prevalence of DR was increased even in the short duration and development/progression rates of DR were increased, while the relative frequency of PDR was decreased. Older-onset DM patients appear to be at a lower risk for progression to PDR.

Adult↗

Risk factors for contraction of the anterior capsule opening after cataract surgery.

PURPOSE: To investigate the factors contributing to contraction of the anterior capsule opening (ACO) after cataract surgery in normal eyes. SETTING: Department of Ophthalmology, University of Tokyo, School of Medicine, Tokyo, and Kaiya Eye Clinic, Hamamatsu, Japan. METHODS: This study included 141 eyes of 141 patients scheduled to have cataract surgery. The area of the ACO was determined by diaphanoscopy using the EAS-1000 anterior eye segment analysis system 1 day and 9 months postoperatively, after which the percentage reduction in the ACO area was calculated. Aqueous flare intensity was measured with a laser flare-cell meter 1 week and 9 months after surgery. Multiple regression analysis was performed to determine which factors were correlated with the percentage reduction in the ACO area. Variables tested included patient age, axial length, the ACO area on the first postoperative day, and flare values 1 week and 9 months after surgery. RESULTS: Patient age (r = 0.193, P =.029) and flare intensity 9 months after surgery (r = 0.255, P =.007) were significantly correlated with the percentage reduction in the ACO area (R(2) = 0.133). The axial length, ACO area 1 day postoperatively, and flare value at 1 week were not correlated with ACO contraction. CONCLUSION: Contraction of the ACO after cataract surgery is related to instability of the blood-aqueous barrier.

Adult↗

Spontaneous posterior dislocation of intraocular lenses fixated in the capsular bag.

We report 4 cases of complete posterior dislocation of an intraocular lens (IOL) in the capsular bag occurring a mean of 5.5 years after uneventful cataract surgery. In all 4 cases, posterior chamber IOLs were fixated within the capsulorhexis. The patients experienced sudden loss of vision without an episode of trauma or ocular disease. Using a 3-port pars plana vitrectomy, the IOLs were explanted through a limbal incision and a new IOL was sutured to the ciliary sulcus. Histological examination indicated that zonular fibers were severed at the site of insertion in the capsule.

Capsulorhexis↗

Mental health of two communities of Japanese-Brazilians: a comparative study in Japan and in Brazil.

The aim of the present study was to assess the mental health status of Japanese-Brazilians living in Kiyoharadai, Japan and compare the findings with the Japanese-Brazilians living in Bauru, Brazil. A comparative community-based mental health survey was conducted from November 1997 to April 1999 on a randomly selected sample of Brazilians of Japanese descent living in Bauru, Brazil (n=213) and on the entire Brazilian community of Kiyoharadai, Utsunomiya, Japan (n=158), using the self-reporting questionnaire (SRQ-20). Analysis was done by chi2, Fisher and multiple logistic regression. Scores indicating probable cases of minor psychiatric disorders, were found in 3.2% of the community in Bauru city and 17.8% (OR=7.01) of the community in Kiyoharadai. The sociodemographic data indicated that those with high SRQ-20 scores were most likely to be female (OR=2.98), smokers (OR=2.76), and those whose former occupation was student when living in Brazil (OR=9.57). The mental health status of the Japanese-Brazilians living in Kiyoharadai, Japan is significantly worse than that of the community living in Bauru, Brazil, particularly among women, smokers and those who were students when living in Brazil. Further research concerning the mental health of this community is necessary and assistance provided.

Adult↗

Epitope distribution of randomly established monoclonal antibodies against human type II DNA topoisomerases.

The epitopes of about 100 monoclonal antibodies against human type II DNA topoisomerase were mapped along the enzyme molecules. Although they were randomly and independently established, epitope sites were unevenly distributed the toward N-terminal or C-terminal region. We suggest that the central catalytic domain is hidden inside the molecule and inaccessible to the antigen recognition sites. Using antibodies, we demonstrate the distinct localization of isoforms of Topo II in cultured cells. Some particularly useful antibodies are listed.

Amino Acid Sequence↗

[Macroscopic indices of psychiatric hospital functions: evaluation based on data of remaining hospitalized patients].

In recent years, mental health administration in Japan has been changing its orientation from institutional care to community-based care. For this reason, we need new macroscopic indices evaluating psychiatric hospital functions. The most notable indices are data of the remaining hospitalized patients. In this paper, we discuss the macroscopic indices evaluating psychiatric hospital functions focusing on the data of the remaining hospitalized patients. The data are based on a survey of the number of monthly discharged patients who had been admitted to 1,617 psychiatric hospitals in the month of June 1998. The result shows that 1. 70.4% of admitted patients are discharged to communities within a year, 2. 18.3% of patients remain hospitalized one year after admission, and 3. 50% of admitted patients are discharged within 74.2 days. Examination of these data showed it is very useful to evaluate psychiatric hospital functions by categorizing psychiatric hospitals based on the rate of patients remaining hospitalized one year after admission. We also found that "the rate of admissions discharged to communities within a year", "the rate of patients remaining hospitalized after one year", "transition in the rate of patients remaining hospitalized", and "the number of days until 50% of admitted patients are discharged" can be used as effective and practical indices evaluating psychiatric hospital functions.

Community Mental Health Services↗

[Clinical study of depression accompanying diabetes mellitus].

The appropriate management of chronic diseases is important to ensure a high quality of life. In particular, depression has been reported to occasionally accompany diabetes mellitus. Here, we investigated depression onset in individuals with diabetes mellitus. Subjects were outpatients with a clinical diagnosis of depression in combination with diabetes mellitus between August 1, 1998 and September 30, 1998 of the psychiatry clinic of Jichi Medical School. Of 34 individuals (20 males, 14 females) included in the preliminary investigation, 22 were interviewed. We investigated the social demographic background, the treatment, family history of depression and diabetes mellitus, and measured the Hamilton's Rating Scale for Depression and the value of HbA1c. The overall male/female ratio was 13/9, indicating that this pattern of disease onset was more common in males than in females. The Hamilton's Rating Scale for Depression correlated closely with the percentage of patients being treated with insulin. Furthermore, the timing of the diagnosis of these two diseases correlated closely with each other. The ratio of males to females suggested that the different gender roles and lifestyles and the biological bases of these differences may play roles in the onset of depression among diabetic patients. Moreover, as more patients with insulin dependence developed depression than patients without insulin, insulin was implicated in the onset of depression. Furthermore, as the onset of the two diseases correlated closely with one another, the onset of one disease may have hastened the onset of the other.

Adult↗

[Recurrent retrieval of the core episode referred to as the onset of schizophrenia--psychopathological study on the autobiographical memory of the onset of the illness].

OBJECTIVE: In this study, we explore the onset of psychotic episodes in schizophrenia. Patients with schizophrenia have sometimes reported specific life-events at the period of onset. For example: "It started on my 22nd birthday. From that day onward, my life was colored with extremes of happiness and tragedies", or "It was when I was playing with a cat in the park of S temple that I realized suddenly that my 'I'-ness had completely changed." In each case, patients referred to a specific event as a critical moment when the meaning of selfness and the surrounding world had changed. Interestingly, these moments were reported repeatedly throughout the history of their illnesses. We termed these clinical phenomena "Recurrent retrieval of the core episode referred to as the onset of schizophrenia" and investigated their psychopathologic implication. METHOD: The autobiographical memory of nine schizophrenic patients with "Recurrent retrieval of the core episode referred to as the onset of schizophrenia" was investigated. Four representative cases are described in detail. Samples of subjective statements were collected from medical records and analyzed. RESULTS: 1) Form and content of the statement: Patients clearly referred to a specific moment in their life. They usually reported that their image of self or the world had completely changed. The content of their reports were always about the same theme. 2) Chronological pattern of the repetition: Although the reported life event occurred just before onset, the reminiscence usually occurred not only at the beginning of the refractory period but also at the beginning of the recovery period. Patients did not report such events when they were stable. In the refractory period, distinct symptoms of schizophrenia were observed after the reminiscence. In the recovery period, the reminiscence was accompanied by minor physical symptoms, such as fever elevation or gastrointestinal dysfunction. 3) Subjective characteristics of repetitive reminiscence: In the refractory period, patients relived the onset of schizophrenia by reporting it reminiscently. They were excited, in a state of high-tension, or feeling oppressed. In contrast, in the recovery period, they reported the critical moment in an emotionally stable state, and even recollected it with humor. They were able to maintain some emotional distance from the reminiscence. 4) Predictive factor on prognosis: Reminiscence in the recovery period predicted a good prognosis. Seven of nine such cases were in remission. Two patients with whom the reminiscence was observed only in the refractory period were chronically ill. Therefore, two patterns of repetitive reminiscence of the critical moment should be discriminated. DISCUSSION: 1. The statements of patients were developed on the possibility that the critical event had not happened. Therefore, it can be postulated that their statements reconstructed a temporality open to any possible future: the moment just before the critical event might not have happened. The proper temporality associated with repetitive reminiscence should be distinguished from that of repetition of a traumatic memory in post-traumatic stress disorder. 2. From a therapeutic viewpoint, it is important to know to whom the discourse of the patient was addressed. In the refractory period, patients reported the repetitive reminiscence to anyone in a non-discriminating fashion. In contrast, in the recovery period, their discourse on the reminiscence was directed to a particular person with whom they were in close contact. The structure of the latter discourse was similar to that of neurotic patients in that they both demand acceptance from others. That is, the discourse structure of our patients was drastically changed in the recovery period. Reconstruction of the critical moment found in the recovery period was accomplished by the patient's discourse directed to another person, one from whom they could realize self-acceptance.

Adolescent↗

[Classification of long-term clinical course of 'atypical psychosis': a 20-year follow-up study at a medical school hospital].

To study the long-term clinical course and outcomes of atypical psychosis, 8 patients diagnosed with atypical psychosis were observed for more than 12 years (mean, 20 years). Retrospective examination was performed, particularly with respect to clinical features at each episode. The overall course of each case was classified as one of the following three types: Type I--"Recurrent confused state" type. Patients frequently repeated acute transient confused or dream-like states in a similar way, sometimes and/or for part of the episode accompanied by a floating paranoid-hallucinatory state. Duration of psychotic episode was short, persisting for a few days to about one month. Type II--"Manic-depressive illness similar" type. After a long course of disease, the predominantly early middle-aged patients (30- to 40 years-old) demonstrated fewer original characteristic features of acute confused or dream-like states. Instead, manic or depressive episodes tended to predominate. Duration of psychotic episodes exceeded the duration of type I episodes, to a maximum of about 3 months. Type III--"Appearance of residual state" type. After several episodes characterized by transient confused state during middle age, residual states consisting of a slight depressive state, reduced spontaneity and flattening of emotions appear. These states become durable and the periodicity of the disease disappeared. We conclude that the core group of atypical psychosis patients presents with confused symptoms as a clinical feature of episodes, and with the recurrent confused state type representing the long-term clinical course. "Shift to manic-depressive illness similar" and "appearance of residual state" types were considered to be derived from the core group, according to the interplay of personality structure and viable dynamics.

Adult↗