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T Kasamatsu

Publications and source records attributed to T Kasamatsu.

At least 19 recordsLinked to original sources
PubMed2005

Genotoxicity studies on dietary diacylglycerol (DAG) oil.

Dietary diacylglycerol (DAG) oil is an edible oil enriched in DAG (more than 80%). A recent investigation indicated that DAG oil or its components may have beneficial effects on the prevention and management of obesity. We evaluated the genotoxic potential of DAG oil using standard genotoxicity tests. Bacterial reverse mutation assay (Ames test), the chromosomal aberration assay in cultured Chinese hamster lung cells (CHL/IU), and a bone marrow micronucleus assay in ICR CD mice were employed in the present study. In addition we have tested the possibility that genotoxic substances may be formed during cooking, heated DAG oil (HDG) was prepared by batch frying potato slices in the oil at 180 degrees C for 8 h/day for three consecutive days. Therefore, genotoxicity tests were also performed on HDG. Results obtained did not show any genotoxic effect on either unheated DAG oil (UDG) or HDG. We conclude that there are no safety concerns on the genotoxicity of DAG oil under the conditions for normal use.

Animals↗
PubMed2005

Clinical aspects and prognosis of pelvic recurrence of cervical carcinoma.

OBJECTIVE: To identify which patients with locally recurrent cervical carcinoma are potentially curable. METHOD: A total of 664 stage IB-IVA patients were examined following surgery or radiotherapy. RESULT: Among the 664 patients, 193 (29%) developed recurrence. Sixty-seven (35%) of these recurrences were located in the pelvis alone. Among these 67 recurrences, 24 (35%) were central recurrences and the remaining 43 (65%) were pelvic side-wall recurrences. Of the 24 patients with central recurrences, 8 were salvaged. Of these 8 patients, 3 underwent pelvic exenteration, and 5 received optimal radiotherapy. The recurrent tumor in these 5 survivors who received radiotherapy had consisted of a small (<2 cm) tumor. All 43 patients with pelvic wall recurrence developed progressive disease. CONCLUSION: The following patients are potentially curable: patients with a resectable, centrally located tumor who are candidates for pelvic exenteration, and patients with a small central recurrence for whom complete radiation therapy is feasible.

Adenocarcinoma↗
PubMed2003

Prognostic significance of positive peritoneal cytology in endometrial carcinoma confined to the uterus.

A retrospective analysis was performed to evaluate the prognostic significance of peritoneal cytology in patients with endometrial carcinoma limited to the uterus. A total of 280 patients with surgically staged endometrial carcinoma that was histologically confined to the uterus were examined clinicopathologically. The median length of follow-up was 62 (range, 12-135) months. All patients underwent hysterectomy and salpingo-oophorectomy with selective lymphadenectomy, and only three patients received adjuvant postoperative therapy. No preoperative adjuvant therapy was employed. In all, 48 patients (17%) had positive peritoneal cytology. The 5-year survival rate among patients with positive or negative peritoneal cytology was 91 or 95%, respectively, showing no significant difference (log-rank, P=0.42). The disease-free survival rate at 36 months was 90% among patients with positive cytology, compared with that of 94% among patients with negative cytology, and the difference was not significant (log-rank, P=0.52). Multivariate proportional hazards model revealed only histologic grade to be an independent prognostic factor of survival (P=0.0003, 95% CI 3.02 - 40.27) among the factors analysed (age, peritoneal cytology, and depth of myometrial invasion). Multivariate analysis revealed that histologic grade (P=0.02, 95% CI 1.21-9.92) was also the only independent prognostic factor of disease-free survival. We concluded that the presence of positive peritoneal cytology is not an independent prognostic factor in patients with endometrial carcinoma confined to the uterus, and adjuvant therapy does not appear to be beneficial in these patients.

Adenocarcinoma↗
PubMed2002

Bone loss at the lumbar spine and the proximal femur in a rural Japanese community, 1990-2000: the Miyama study.

Bone mineral density (BMD) was measured over a ten year period in a cohort study in Miyama village, Wakayama Prefecture, Japan, to provide information on rate of bone loss in the mature and elderly population. Four hundred subjects were selected by sex and age decade from the full list of residents born in 1910-1949, and aged 40-79 years at the end of 1989, with 50 men and 50 women in each age decade. Baseline BMD of the lumbar spine and the proximal femur was measured using dual energy X-ray absorptiometry (DXA) in 1990 and again in 1993, 1997 and 2000. Annual rate of change in BMD (% per year) in the lumbar spine in men in their forties, fifties, sixties and seventies was 0.17, 0.55, 0.01 and -0.16, respectively, and in women, -0.87, -0.83, -0.48 and -0.48, respectively. Thus in men, BMD at the lumbar spine increased in all age strata but the oldest, when it decreased, whereas in women, it decreased in all age strata. On the other hand, BMD at the proximal femur decreased in both sexes in all age strata. Our results show that bone loss rates differ depending on the site involved, demonstrating that different strategies are needed for the prevention of bone loss in the spine and hip.Furthermore, we found evidence of differences in BMD for given age strata between birth cohorts. Data in 1990 and in 2000 showed significant improvements for men in their sixties and for women in their fifties, suggesting that future problems of osteoporosis might be less severe than has previously been predicted in Japan.

Absorptiometry, Photon↗
PubMed2001

Contrast response characteristics of long-range lateral interactions in cat striate cortex.

Single-cell responses in visual cortex to a target falling within their receptive field can be modified by collinear flanking stimuli concurrently presented outside the receptive field. Here, we report the presence of four types of contrast-dependent lateral effects: (1) facilitation at low target contrasts and suppression at high contrasts, (2) facilitation that increases with contrast, (3) suppression that increases with contrast, and (4) suppression at low contrasts with facilitation at high contrasts. We propose a sensitivity modulation model that accounts for all the four types of lateral effects by changes in two parameters. In this model, activation of neighboring neurons changes the sensitivities of the target neuron to both the direct feedforward input and inhibitory, divisive feedback from neighboring neurons.

Animals↗
PubMed2001

Colinear facilitation promotes reliability of single-cell responses in cat striate cortex.

Behavior is controlled by neural activity in the brain. The final outcome of this neural control may critically depend on the firing reliability of individual neurons. A nearly constant, proportional relationship is usually found between the response mean and response variance. Here we asked whether lateral interactions within striate cortex that modulate response magnitude also proportionately modify the response variance of cortical neurons. In many cases, response variability depended on stimulus organization: discrete flankers colinearly placed well outside the neuron's receptive field increased response magnitude without a proportional increase in variance, thus improving the neuron's response reliability. Since colinear flanker facilitation is often seen near the neuron's firing threshold, increased response reliability for weak stimuli may contribute to enhancing perceptual saliency.

Animals↗
PubMed2000

Variants of NOS1, NOS2, and NOS3 genes in asthmatics.

Nitric oxide (NO) gas concentrations are higher in expired air in asthmatics. NO is synthesized by three isoforms of NO synthase (NOS) encoded by three distinct genes, NOS1, NOS2, and NOS3. Genome-wide searches have identified linkages to asthma on chromosomes 7, 12, and 17 where these three genes are localized. No association study, however, has been reported to date. To test whether variants of NOS1, NOS2, and NOS3 relate to asthma, a genetic association study was conducted in a British population (n = 300). Intragenic microsatellite variants of NOS1 were significantly associated with asthma [odds ratio (OR) = 2.08, 95% CI: 1.20-3.57 (95% CI), P = 0.008 (Pc = 0.048)], but not with IgE levels. Neither NOS2 nor NOS3 variants showed any association with asthma nor IgE levels. These findings suggest that NOS1 variants may be a significant contributor to asthma in a British population.

Alleles↗
PubMed2000

Effect of hormone replacement therapy on the bone mass and urinary excretion of pyridinium cross-links.

CONTEXT: The menopause accelerates bone loss and is associated with an increased bone turnover. Bone formation may be evaluated by several biochemical markers. However, the establishment of an accurate marker for bone resorption has been more difficult to achieve. OBJECTIVE: To study the effect of hormone replacement therapy (HRT) on bone mass and on the markers of bone resorption: urinary excretion of pyridinoline and deoxypyridinoline. DESIGN: Cohort correlational study. SETTING: Academic referral center. SAMPLE: 53 post-menopausal women, aged 48-58 years. MAIN MEASUREMENTS: Urinary pyr and d-pyr were measured in fasting urine samples by spectrofluorometry after high performance liquid chromatography and corrected for creatinine excretion measured before treatment and after 1, 2, 4 and 12 months. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry (DEXA) before treatment and after 12 months of HRT. RESULTS: The BMD after HRT was about 4.7% (P < 0.0004); 2% (P < 0.002); and 3% (P < 0. 01) higher than the basal values in lumbar spine, neck and trochanter respectively. There were no significant correlations between pyridinium cross-links and age, weight, menopause duration and BMD. The decrease in pyr and d-pyr was progressive after HRT, reaching 28.9% (P < 0.0002), and 42% (P < 0.0002) respectively after 1 year. CONCLUSIONS: Urinary pyridinoline and deoxypyridinoline excretion decreases early in hormone replacement therapy, reflecting a decrease in the bone resorption rate, and no correlation was observed with the bone mass evaluated by densitometry.

Absorptiometry, Photon↗
PubMed1999

Restoration of ocular dominance plasticity mediated by adenosine 3',5'-monophosphate in adult visual cortex.

Noradrenaline (NA)-stimulated beta-adrenoreceptors activate adenylate cyclase via excitatory G-proteins (Gs). Activated adenylate cyclase in turn promotes the production of cAMP. Critical roles of cAMP-dependent protein kinase A (PKA) in divergent cellular functions have been shown, including memory, learning and neural plasticity. Ocular dominance plasticity (ODP) is strongly expressed in early postnatal life and usually absent in the mature visual cortex. Here, we asked whether the activation of cAMP-dependent PKA could restore ODP to the aplastic visual cortex of adult cats. Concurrent with brief monocular deprivation, each of the following cAMP-related drugs was directly and continuously infused in the adult visual cortex: cholera toxin (a Gs-protein stimulant), forskolin (a Gs-protein-independent activator of adenylate cyclase) and dibutyryl cAMP (a cAMP analogue). We found that the ocular dominance distribution became W-shaped, the proportion of binocular cells being significantly lower than that in respective controls. We concluded that the activation of cAMP cascades rapidly restores ODP to the adult visual cortex, though moderately. The finding further extends the original hypothesis that the NA-beta-adrenoreceptors system is a neurochemical mechanism of cortical plasticity.

Animals↗
PubMed1999

Biochemical markers of bone turnover and bone loss at the lumbar spine and femoral neck: the Taiji study.

The purpose of this study was to ascertain whether biochemical markers of bone turnover predict bone loss. The survey was carried out in Taiji, Wakayama Prefecture, Japan. From a list of inhabitants aged 40-79 years, 400 participants (50 men and 50 women in each of four age groups) were selected randomly. Bone mineral density (BMD) was measured, and blood and urine samples of all participants were examined to obtain values for eight biochemical markers: alkaline phosphatase (ALP), bone Gla protein (BGP), type I procollagen (carboxyterminal peptide of type I procollagen; PICP), cross-linked carboxyterminal telopeptide region of type I collagen (ICTP), and urinary excretion of calcium (Ca), phosphate (P), pyridinoline (Pyr), and deoxypyridinoline (D-Pyr). Each marker was evaluated as a predictor of the rate of bone change in lumbar spine and femoral neck BMD over a 3-year period. The value of Pyr was significantly related to the change of lumbar spine BMD in men (P = 0.009), and that of BGP was found to be significant in women (P = 0.045). By contrast, none of the bone markers significantly correlated with bone loss at the femoral neck. The coefficient of determination at the lumbar spine was 5% and 7% at the femoral neck only. We conclude that biochemical markers of bone turnover cannot predict bone loss rates in middle-aged or elderly Japanese men and women over a 3-year period with sufficient accuracy for use in clinical decision making.

Adult↗
PubMed1999

Stroke incidence and case fatality in Shiga, Japan 1989-1993.

BACKGROUND: This paper describes incidence rates and case-fatality for sub-types of stroke using data collected in Takashima, Shiga, Japan, from 1989 to 1993 and compares these with similar registers in other parts of Japan. METHODS: Registered patients included all residents of the county who experienced a first-ever stroke. Stroke was defined as sudden onset of neurological symptoms which continued for a minimum of 24 hours or led to death. Almost all such patients are hospitalized in this country. Early case fatality was defined as patients who died within 28 days of stroke onset. Diagnosis of stroke type was based on clinical symptoms as well as computed tomography (CT) scans. RESULTS: Age-adjusted incidence rates for stroke per 100,000 population aged 35 years and older were 268.7 for men and 167.5 for women. The age-specific incidence rate of both cerebral infarction and cerebral haemorrhage increased with advancing age. The occurrence of cerebral infarction in men was twice as high as in women. The 28-day case fatality for all sub-types of stroke was 16.1% in men and 15.8% in women. Case fatality for cerebral infarction, cerebral haemorrhage, and subarachnoid haemorrhage was 10.7%, 22.4% and 28.6% respectively. CONCLUSIONS: Takashima County has a moderately high stroke incidence rate and case fatality compared with other similar studies in Japan. The incidence rate of cerebral infarction in men is twice that in women, while other sub-types of stroke showed smaller differences. In order to decrease the incidence of stroke in Japan, greater efforts at primary prevention will be necessary, in particular, it is important to prevent cerebral infarction in men.

Adult↗
PubMed1999

A clinicopathological study of postoperative pulmonary metastasis of uterine cervical carcinomas.

OBJECTIVE: To investigate the clinicopathological backgrounds and prognostic factors of uterine cervical carcinomas metastatic to the lung. METHODS: A total of 519 patients with invasive cervical carcinoma (Stage pTIb-IIb) treated by abdominal radical hysterectomy at the Saitama Cancer Center from January 1, 1976 to December 31, 1989 were analyzed clinicopathologically. RESULTS: The frequencies of pulmonary metastasis were 6.4% (24/377) and 11.3% (16/142) in patients with negative and positive pelvic lymph nodes, respectively. Among 24 negative lymph node patients, 15 had pulmonary metastasis only. The overall 5-year survival rate of these 15 patients was 36% after relapse. Of the 15, the prognosis of 12 patients with 1-3 pulmonary metastases only was better, that is, 46% after surgical resection (mean size of resectable tumor = 2.8 cm) and/or chemotherapy. But the other patients died within 3.3 years after relapse. CONCLUSIONS: The occurrence of pulmonary metastasis only, its number (1-3) and size (mean size = 2.8 cm), and no lymph node metastasis are important prognostic factors. For these patients, active surgical resection of the pulmonary lesion(s) and further chemotherapy are recommended in order to improve their prognosis.

Adenocarcinoma↗
PubMed1999

Clinicopathological study of recurrent uterine cervical squamous-cell carcinoma.

OBJECTIVE: To improve prognoses of patients with recurrent uterine cervical squamous-cell carcinoma. PATIENTS AND METHODS: We clinicopathologically analyzed 464 patients with uterine cervical squamous-cell carcinoma (126 positive, 338 negative pelvic lymph-node metastasis) who were treated at the Saitama Cancer Center from January 1, 1976 to December 31, 1991. RESULTS: The recurrence rates of negative pelvic lymph-node metastasis patients were 14. 2% (39/274) in pT1b and 32.8% (21/64) in pT2b. But for positive lymph-node metastasis patients the rates were 39.0% (23/59) in pT1b and 58.2% (39/67) in pT2b. The interval to recurrence was shorter in positive pelvic lymph-node patients than in negative patients. The 5-year survival rates after relapse of negative lymph-node patients with intrapelvic, extrapelvic, and both-sites recurrence were 53, 12, and 40%, respectively. But among distant recurrent sites, lung metastasis in negative lymph-node patients and lymphatic tract metastasis brought relatively fair prognoses. CONCLUSIONS: Regular long-term checks are necessary and active retreatments are recommended for patients with local recurrences, lung metastasis, or lymphatic vessel metastatic lesions.

Bone Neoplasms↗
PubMed1998

Collinear stimuli regulate visual responses depending on cell's contrast threshold.

Neurons in the primary visual cortex are selective for the size, orientation and direction of motion of patterns falling within a restricted region of visual space known as the receptive field. The response to stimuli presented within the receptive field can be facilitated or suppressed by other stimuli falling outside the receptive field which, when presented in isolation, fail to activate the cell. Whether this interaction is facilitative or suppressive depends on the relative orientation of pattern elements inside and outside the receptive field. Here we show that neuronal facilitation preferentially occurs when a near-threshold stimulus inside the receptive field is flanked by higher-contrast, collinear elements located in surrounding regions of visual space. Collinear flanks and orthogonally oriented flanks, however, both act to reduce the response to high-contrast stimuli presented within the receptive field. The observed pattern of facilitation and suppression may be the cellular basis for the observation in humans that the detectability of an oriented pattern is enhanced by collinear flanking elements. Modulation of neuronal responses by stimuli falling outside their receptive fields may thus represent an early neural mechanism for encoding objects and enhancing their perceptual saliency.

Animals↗
PubMed1998

Leiomyosarcoma of the uterine cervix.

The clinicopathologic features of a patient with uterine leiomyosarcoma arising in the cervix are presented. A 47-year-old Japanese woman was admitted with complaints of hypermenorrhea and abdominal distention. A hysterectomy with bilateral salpingo-oophorectomy revealed a tumor weighing 10.5 kg, which was the largest cervical leiomyosarcoma reported in the literature. She was given eight courses of combination chemotherapy (VADIC and Hydroxyurea, DTIC, Etoposide) and is alive without evidence of recurrence 35 months after the initial therapy.

Female↗
PubMed1998

Oxidation of N-methyl(R)salsolinol: involvement to neurotoxicity and neuroprotection by endogenous catechol isoquinolines.

1(R), 2(N)-Dimethyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline, N-methyl(R)salsolinol, is a potent dopaminergic neurotoxin to induce parkinsonism in rats. The cytotoxicity of N-methyl(R)salsolinol proved to be ascribed to its oxidation into cytotoxic 1,2-dimethyl-6,7-dihydroxyisoquinolinium ion with generation of hydroxyl radical. The isoquinolinium ion caused massive necrosis in the striatum, whereas N-methyl(R)salsolinol depleted selectively dopaminergic neurons in the substantia nigra without necrotic tissue reaction. N-Methyl(R)salsolinol induced DNA damage to human neuroblastoma SH-SY5Y cells, which could be prevented by anti-oxidants and cycloheximide. These results suggest that oxidative stress through oxidation of N-methyl(R)salsolinol induces apoptotic cell death. On the other hand, (R)salsolinol proved to scavenge hydroxyl radical produced by oxidation of dopamine. The neurotoxicity and neuroprotection of catechol isoquinolines may be ascribed to their oxidation and scavenging of radicals.

3,4-Dihydroxyphenylacetic Acid↗