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T Kato

Publications and source records attributed to T Kato.

At least 361 records · Page 20Linked to original sources
PubMed2001

Platelet-derived growth factor BB-induced p38 mitogen-activated protein kinase activation causes cell growth, but not apoptosis, in vascular smooth muscle cells.

The aim of this experiment was to examine the regulation of p38 mitogen-activated protein (MAP) kinase by platelet-derived growth factor (PDGF)-BB and its biological effects on rat cultured vascular smooth muscle cells (VSMCs). VSMCs were obtained from aortae of male Wistar rats by the media explant technique. After being stimulated by PDGF-BB with or without the p38 MAP kinase-specific inhibitor, SB-203580, the cells were solubilized, and the levels of phosphorylated p38 MAP kinase were examined by immunoblot analysis. The amounts of DNA synthesis and content were measured by using [3H]-thymidine and Hoechst-33258 dye, respectively. The detection of apoptotic cells was evaluated by the TUNEL method. PDGF-BB could phosphorylate p38 MAP kinase dose-dependently, and the phosphorylation was specifically inhibited by SB-203580 in a dose-dependent manner. However, PDGF-BB did not affect the protein level of p38 MAP kinase. Both [3H]-thymidine incorporation and total cellular DNA content were increased by PDGF-BB, and these elevations were prevented by SB-203580. In contrast, PDGF-BB-stimulated VSMCs did not show apoptotic change in spite of the presence or absence of SB-203580. These results established that PDGF-BB activated p38 MAP kinase and subsequently regulated cell growth in VSMCs, providing a molecular mechanism by which p38 MAP kinase can cause the development of cardiovascular diseases, including atherosclerosis.

Animals↗
PubMed2001

Hypocarbia in preterm infants with periventricular leukomalacia: the relation between hypocarbia and mechanical ventilation.

OBJECTIVE: The aim of this study was to elucidate the relationship between mechanical ventilation and hypocarbia in infants with periventricular leukomalacia (PVL). STUDY DESIGN: Matched pair analysis was conducted for 26 infants with PVL and 26 with normal development, who were born between 27 and 32 weeks' gestational age and required mechanical ventilation. The time-averaged carbon dioxide (CO(2)) index, PaCO(2), and pH were calculated every 24 hours for samples obtained from indwelling arterial catheters within the first 72 hours of life. The time-averaged respiratory rate of the ventilator (RR), peak inspiratory pressure (PIP), mean airway pressure (MAP), and ventilator index (VI) were also determined. The time-averaged total respiratory rate (TRR) was determined by observing the movement of the chest wall. The patients' characteristics, antenatal and neonatal variables, and electroencephalographic findings were also compared. RESULTS: The time-averaged CO(2) index was larger, the time-averaged CO(2) lower and the time-averaged pH higher in infants with PVL than in those with normal development on the third day of life. There was no significant difference in the time-averaged RR, PIP, MAP, or VI on any day. TRR was larger in the PVL group than in the control group on each day, but there was no significant difference. No significant difference was observed in the clinical characteristics or neonatal variables. Electroencephalographic abnormalities within 48 hours of life were more frequent in infants with PVL than in those with normal development. CONCLUSION: Hypocarbia was associated with PVL because the time-averaged CO(2) index was larger and the time-averaged PaCO(2) lower in infants with PVL than in those with normal development. However, the ventilator settings were similar among the infants with and without PVL.

Blood Gas Analysis↗
PubMed2001

Quantitative analysis of gene expressions of vascular endothelial growth factor-related factors and their receptors in renal cell carcinoma.

Vascular endothelial growth factor (VEGF)-related factors are believed to regulate angiogenesis, an essential event in the growth of solid tumors. In this study, we investigated the expression of VEGF-related factor genes (VEGF, VEGF-B, and VEGF-C) and their receptor genes (VEGFR-1 and VEGFR-2) in renal cell carcinoma (RCC). There were significant differences in the expression level of VEGF, VEGFR-1 and VEGFR-2 between RCC and the corresponding normal renal tissue. The expression level of VEGF in the tumor tissue significantly correlated with those of VEGFR-1 and VEGFR-2. Expression levels VEGF-B and VEGF-C genes were not significantly different between RCC and normal renal tissue. A moderate to high protein expression for VEGF, VEGFR-1, and VEGFR-2 was observed in both the tumor cells and the endothelial cells, whereas the protein expression was low for VEGF-B and VEGF-C. The present results suggested that VEGF and its receptors VEGFR-1 and VEGFR-2 cooperates to play a crucial role in the angiogenesis of RCC, while VEGF-B and VEGFR-C may not. Furthermore, since VEGFR-1 and VEGFR-2 proteins were expressed in the tumor cells as well as in the endothelial cells, these receptors may also be responsible for the progression of RCC.

Aged↗
PubMed2001

Effect of eicosapentaenoic acid ethyl ester on hypothyroid function.

Thyroid hormones affect reactions in almost all pathways of lipid metabolism. It has been reported that plasma free fatty acid (FFA) concentration in hypothyroidism is generally within the normal range. In this study, however, we show that plasma FFA concentration in some hypothyroid patients is higher than the normal range. Symptoms of thyroid dysfunction in these individuals were less severe than those of patients with lower plasma FFA concentrations. From these findings we hypothesized that the change in FFA concentration must correlate with thyroid function. Using an animal model, we then examined the effect of highly purified eicosapentaenoic acid ethyl ester (EPA-E), a n-3 polyunsaturated fatty acid derived from fish oil, on thyroid function in 1-methyl-2-imidazolethiol (MMI)-induced hypothyroid rats. Oral administration of EPA-E inhibited reduction of thyroid hormone levels and the change of thyroid follicles in MMI-induced hypothyroid rats. These findings suggest that FFA may affect thyroid functions and EPA-E may prevent MMI-induced hypothyroidism.

Animals↗
PubMed2001

Therapeutic effect of balloon-occluded retrograde transvenous obliteration on portal-systemic encephalopathy in patients with liver cirrhosis.

OBJECTIVE: Balloon-occluded retrograde transvenous obliteration (B-RTO) has recently been introduced as a new interventional modality to prevent fatal bleeding from solitary gastric varices. A large portal-systemic shunt including gastric varices also causes severe encephalopathy in some cirrhotic patients. In this study, we evaluated the effect of B-RTO as a candidate therapeutic method to treat chronic recurrent hepatic encephalopathy due mainly to a portal-systemic shunt. PATIENTS AND METHODS: Since July 1995, we experienced 43 cirrhotic patients with chronic reccurent hepatic encephalopathy. Among them, six patients had anigographically proven large (>1 cm in diameter) portal-systemic shunt, and received B-RTO. B-RTO was carried out only once using 5% ethanolamine oleate with iopamidole to obliterate the portal-systemic shunt for 30 minutes. The median observation period after B-RTO was 29 months (range 23-46 months). RESULTS: In all 6 patients, encephalopathy had disappeared after B-RTO, and the patients were free of encephalopathy during the following 6 months. B-RTO significantly reduced blood ammonia levels at one month, 3 months, and 6 months later, without affecting serum aspartate aminotransferase activity, total bilirubin and albumin concentrations, and plasma prothrombin time. Encephalopathy relapsed in 4 patients between 6 and 30 months. Additional B-RTO was required and effective in 2 of them. CONCLUSION: B-RTO is an effective treatment for chronic recurrent hepatic encephalopathy with an angiographically proven portal-systemic shunt.

Aged↗
PubMed2001

Adenomatoid hyperplasia of the palate mimicking clinically as a salivary gland tumor.

This report describes an illustrative case of adenomatoid hyperplasia (AH) of the minor salivary glands on the palate of a 31-year-old man. The clinical features of the present lesion corresponded with those of pleomorphic adenoma, but histologically large lobules of normal-appearing mucous acini were found. The cell proliferative activity demonstrated in histological sections, by an immunohistochemical staining of proliferating cell nuclear antigen and Ki-67, showed no statistically significant differences among AH and a matched control group of normal palatal salivary glands. This case suggests that AH apparently exhibits an idiopathic, focal hypertrophic lesion of intraoral mucous glands with limited growth potential.

Adenoma, Pleomorphic↗
PubMed2001

Primary intraosseous carcinoma associated with impacted third molar of the mandible: review of the literature and report of a new case.

This study investigated the clincopathologic features of primary intraosseous carcinoma (PIOC) related to the third molar of the mandible. Six cases (5 from the literature and 1 new case; mean patient age 73 years) of PIOC associated with completely impacted lower third molar were analyzed. For comparison, 8 cases of PIOC presenting after extraction of the lower third molar were also evaluated, with a significantly lower mean patient age of 56 years. Most lesions were deceptively similar to those related to the lateral type of dentigerous cyst, and half of the impacted cases revealed an asymptomatic fracture of the mandible. In all patients except for the present case, metastasis had not been recorded. Surprisingly, no patients are known to have died of PIOC. In our experience the prognosis of PIOC associated with a completely impacted third molar is much better than commonly believed, although the number of cases involved is too small to make a general conclusion. However, delay in establishing the correct diagnosis followed by extraction without awareness of the carcinoma is know to adversely affect the prognosis.

Age Factors↗
PubMed2001

Genotype Arg/Arg, but not Trp/Arg, of the Trp64Arg polymorphism of the beta(3)-adrenergic receptor is associated with type 2 diabetes and obesity in a large Japanese sample.

OBJECTIVE: Despite a large number of studies, no association of the Trp64Arg polymorphism of the beta(3)-adrenergic receptor gene with obesity and type 2 diabetes has yet to be clearly elucidated. We examined the associations in a large population-based sample. RESEARCH DESIGN AND METHODS: A total of 1,685 subjects (935 women and 750 men, aged 58.7 +/- 12.4 years) from a cohort population (n = 3,706) of the Funagata Diabetes Study were divided into three groups according to genotypes: Trp/Trp (n = 1,155), Trp/Arg (n = 486), and Arg/Arg (n = 44). Glucose tolerance was diagnosed according to the 1985 World Health Organization criteria. Subjects who had a BMI > or =30 kg/m(2) were considered obese. Associations with the traits related to obesity, diabetes, hypertension, and dyslipidemia were also examined. The chi(2) test and analysis of variance were used for the association studies and to assess the differences in the traits' values, respectively. RESULTS: More subjects with genotype Arg/Arg were obese and had diabetes (13.6% for each) than those with genotype Trp/Trp (3.29%, P < 0.001; and 4.16%, P = 0.007, respectively) or genotype Trp/Arg (2.06%, P < 0.001; and 5.97%, P = 0.051, respectively). No significant differences in the frequencies of occurrence of these conditions were observed between genotypes Trp/Arg and Trp/Trp. Traits related to obesity, such as percent body fat (28.82 +/- 7.95 vs. 25.93 +/- 7.21, P = 0.038) and BMI (25.07 +/- 3.84 vs. 23.63 +/- 3.18, P = 0.018), were higher in the genotype Arg/Arg than in the genotype Trp/Trp groups. CONCLUSIONS: Genotype Arg/Arg, but not Trp/Arg, of the beta(3)-adrenergic receptor was associated with both obesity and type 2 diabetes in a large Japanese sample.

Aged↗
PubMed2001

An experimental consideration of fixation properties.

While varying the size and complexity of a stimulus object, we measured eye movements during fixation. Although subjects' eyes are fixated at the center of the object, the experimental results indicate that "fluctuation during fixation (FDF)" which is larger movements than "miniature eye movements" occurred. In addition, FDF varies according to the peripherals of fixation points characterized by the size and complexity of the stimulus object.

Adult↗
PubMed2001

[Statistical observation of vertigo and dizziness patients].

Subjects visiting the Department of Otolaryngology at Suita Municipal Hospital reporting vertigo or dizziness numbered 664 women and 343 men from April 1999 to December 2000. As a city hospital, we play an important role in the diagnosis and treatment of acute vertigo or dizziness. The frequency of diagnosis of these cases was divided almost equally into 5 groups: (1) benign paroxysmal positional vertigo (BPPV) 23%; (2) suspected BPPV, 18%; (3) peripheral vestibular disorders other than BPPV, 22%; (4) disorders other than peripheral origin, 18%; and (5) undiagnosed, 19%. Based on our results, BPPV, other peripheral vestibular disorders, and disorders of other origins should be differentiated from the first screening. BPPV was most frequent and diagnosed by typical positioning nystagmus. Many other peripheral vestibular disorders were accompanied by nystagmus. It is also important to differentiate serious illnesses such as cerebrovascular disease (7%), space-occupying lesions in the posterior fossa (1.2%), and cardio-circulatory disease (3.6%).

Adult↗
PubMed2001

[Clinical features of benign paroxysmal positional vertigo].

Our understanding of the pathomechanism of benign paroxysmal positional vertigo (BPPV) has improved dramatically. A type of BPPV featuring mixed torsional and vertical nystagmus induced by the Dix-Hallpike maneuver involves the posterior semicircular canal (P-BPPV). The other type of BPPV featuring horizontal nystagmus induced by spine-to-lateral head positioning involves the horizontal canal BPPV (H-BPPV). In complaints of vertigo or dizziness, 619 patients visited our department last year. Of these, 142 (23%) was had positional nystagmus consistent with a diagnosis of BPPV, 118 (19%) had no nystagmus but were suspected of BPPV due to vertigo episodes. BPPV was the most frequent diagnosis. H-BPPV was not rare, but accounted for 30% of BPPV. Of H-BPPV, 73% featured direction changing geotropic nystagmus, and 27% direction changing apogeotropic nystagmus. H-BPPV resolved faster than P-BPPV. Most cases caused by head trauma were P-BPPV. Transition between P- and H-BPPV was found in 6 cases. Women outnumbered men by about 3 to 2 in both P- and H-BPPV. Peak incidence was found in the those in their 60s and 70s, suggesting that the etiologies of both types of BPPV are essentially the same.

Adult↗
PubMed2001

[Functional hemispheric asymmetry in sustained attention].

This study examined the existence of functional hemispheric asymmetry in visual sustained attention in a dual-task setting. In the experiments, a circular arrangement of Gabor patches (GPs) was successively presented in the periphery during a 40-min vigil. The primary task was successive discrimination of digit type (Experiment 1) or tone frequency (Experiment 2). The secondary task was oddball orientation detection, requiring subjects to determine whether all of GPs were same or whether there was an odd one in the upper left, upper right, lower left, or lower right visual fields. Overall, results indicated that the perceptual sensitivity (A') for the detection task was higher in the left visual field than in the right visual field. Visual field differences in the vigilance decrement (the decline in A' over time) were observed when the primary task involved auditory discrimination. The implications for the functional lateral asymmetry in human sustained attention are discussed.

Adult↗
PubMed2001

[The relationship between flexibility of coping to stress and depression].

The present study was conducted to examine the relationship between flexibility of coping to interpersonal stress and mental health as represented by scores on a self-report depression scale (CES-D) in 87 college students. Subjects were first required to complete the Interpersonal Stress-Coping Inventory (ISI) to identify each subject's coping type (ISIpre). They were then asked to complete ISI again (ISIpost) assuming that the coping strategy they adopted in ISIpre did not work well. The results of ISIpre and ISIpost were then compared and the flexibility of coping to stress of each individual was analyzed in terms of his/her tendencies: (a) to abandon the type they adopted in ISIpre (Level A flexibility); and (b) to adopt a new coping type (Level B flexibility). Flexible copers in both Levels A and B were shown to be significantly less depressive as represented by scores in CES-D, those fulfilling both flexibility criteria being the least depressive. The results were discussed with reference to mental health and to functional fixedness/recentering in problem solving.

Adaptation, Psychological↗
PubMed2001

Impact of histological grade of hepatocellular carcinoma on the outcome of liver transplantation.

HYPOTHESIS: Histological grade of hepatocellular carcinoma (HCC) is an important prognostic factor affecting patient survival after orthotopic liver transplantation (OLT). DESIGN: Retrospective analysis. SETTING: University-based teaching hospital. PATIENTS: Of 952 OLTs performed between June 1991 and January 1999, 56 OLT recipients had histologically proven HCC in the explant liver. Of those, 53 patients with complete clinicopathologic data were analyzed. A single pathologist blinded to the outcome of each patient reviewed all histological specimens. RESULTS: Median follow-up was 709 days. Overall survival for patients with tumors sized 5 cm or less at 1, 3, and 5 years was 87%, 78%, and 71%, respectively (Kaplan-Meier). Univariate analysis revealed the size, number, and distribution of tumors; the presence of microscopic vascular invasion and lymph node metastasis; histological differentiation; and pTNM stage to be statistically significant factors affecting survival. Multivariate analysis revealed histological differentiation and pTNM stage to be the independent and statistically significant factors affecting survival (P =.002 and.03, respectively). When pTNM stage was excluded from multivariate analysis, histological differentiation and size remained the significant independent factors (P =.02 and.03, respectively). Three-year survival for patients with small (</=5 cm) tumor with well- to moderately differentiated and poorly differentiated HCC was 82% and 67%, respectively. Three-year survival for patients with large (>5 cm) tumor with well- to moderately differentiated and poorly differentiated HCC was 62.5% and 0%, respectively. CONCLUSIONS: In our retrospective experience, histological differentiation had a statistically significant effect on the prognosis of HCC after OLT. However, before altering the current OLT selection criteria for patients with HCC, prospective studies are required to confirm the impact of histological grade on clinical outcome.

Carcinoma, Hepatocellular↗
PubMed2001

Invited response

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Journal Article↗
PubMed2001

Platelets exposed to elevated levels of endogenous thrombopoietin in vivo have a reduced response to megakaryocyte growth and development factor in vitro.

Thrombopoietin (TPO), or megakaryocyte growth and development factor (MGDF), has been shown to potentiate the sensitivity of normal human platelets to various agonists in vitro. The present study investigated the functional and biochemical properties of platelets from mice rendered thrombocytopenic by sublethal irradiation with regard to the reactivity to recombinant murine MGDF (rmMGDF) in vitro. During the course of reversible thrombocytopenia following irradiation, platelets from irradiated mice which had lower platelet counts and reciprocally higher plasma TPO levels showed lower reactivity to rmMGDF in agonist-induced platelet aggregation. Intravenous injections of recombinant soluble murine c-Mpl (sMpl), which has the ability to capture TPO, after irradiation restored the reactivity of platelets at the platelet nadir to rmMGDF. On the other hand, platelets prepared from normal mice 3 h after a single intravenous injection of pegylated rmMGDF did not respond to rmMGDF. There was a marked decrease in c-Mpl and Janus kinase 2 (JAK2) in platelets from irradiated mice at the platelet nadir. Similar results were observed with platelets from mice administered pegylated rmMGDF. JAK2 was only moderately decreased, however, in platelets from mice given sMpl after irradiation. These results indicate that exposure of platelets to increased endogenous TPO levels in vivo in thrombocytopenic mice leads to a reduction in the platelet reactivity to rmMGDF in vitro. Further, these results suggest that the c-Mpl-mediated signaling pathway, which is essential for the priming effect of rmMGDF, is defective in thrombocytopenic murine platelets.

Animals↗