PubMed Health⌕ Search

Biomedical subjects

Tsuyoshi Suzuki

Publications and source records attributed to Tsuyoshi Suzuki.

At least 19 recordsLinked to original sources
PubMed2006

Skull metastases from atypical pulmonary carcinoid tumor in a 19-year-old man.

A 19-year-old man presented with a rare skull metastasis from atypical pulmonary carcinoid tumor (APCT) manifesting as headache, diplopia, and cough. Head magnetic resonance imaging showed a skull base tumor extending from the posterior clinoid process to the clivus, and calvarial tumors in the right temporal and occipital bones. Chest and abdominal computed tomography showed a round tumor, 4 cm in diameter, in the lower lobe of the right lung and multiple small tumors in the liver. Surgery for the calvarial tumor in the right temporal bone was performed on June 27, 2003. The histological diagnosis was skull metastasis of neuroendocrine tumor. Gamma knife radiosurgery was performed for the residual skull metastases. Partial resection of the right lower lobe was performed for the lung tumor on August 22, 2003. The histological diagnosis was atypical carcinoid tumor. Subsequent adjuvant systematic chemotherapy was performed. The patient died of progression of the tumors in the lung and liver on April 19, 2004. We must consider APCT in the differential diagnosis of pulmonary tumors in adolescents, and perform follow-up observation or treatment, including surgery, if APCT is suspected.

Adult↗
PubMed2005

Inhibition of glioma cell proliferation by neural stem cell factor.

Neural stem cells (NSC) have unique differentiation-, proliferation-, and motility properties. To investigate whether they secrete factors that interfere with the proliferation of glioma cells, we grew glioma cells in conditioned medium (CM) obtained from cultures of neurospheres including neural stem / progenitor cells (NSPC) isolated from embryonic (E14)- or adult mouse brain or fetal human brain. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and BrdU-labeling assays showed that CM from NSPC (NSPC/CM) contained factor(s) that inhibited the proliferation of glioma cells by 28-87%. Filter-fractionation of NSPC/CM revealed that the 50,000-100,000 nominal molecular weight limit (NMWL) fraction contained the inhibitory activity. On the basis of these observations we transplanted 203G glioma cells and/or NSPC into the intrathecal space of the cisterna magna of mice to investigate whether NSPC interfere with the proliferation of glioma cells in vivo. Mice transplanted with both 203G and NSPC survived significantly longer than did mice transplanted only with 203G. We concluded that NSPC secrete factor(s) that may control glioma cell proliferation.

Animals↗
PubMed2005

Ganglioside GM3 inhibits proliferation and invasion of glioma.

GM3, the simplest ganglioside, modulates cell adhesion, proliferation and differentiation in the central nervous system and exogenously added GM3 regulates cell-cell and cell-extracellular matrix adhesion and induces apoptosis. To assess the anti-tumor action of exogenous GM3, we examined its effect on the proliferation and invasion of glioma cells. Its inhibitory effect on cell proliferation was demonstrated in vitro by 3-(4,5-dimethyl-2-thiazol-2-yl) 2,5-diphenyltetrazolium bromide (MTT) assay and in vitro in rats with meningeal gliomatosis whose survival was significantly prolonged by the intrathecal injection of GM3. Terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling (TUNEL) assay revealed that GM3 induced glioma cell apoptosis in vitro and in vitro. In rat brain slice cultures, GM3 suppressed the invasion of glioma cells; this effect manifested earlier than the inhibition of cell proliferation and before apoptosis induction. Our results suggest exogenous GM3 as a potential therapeutic agent in patients with glioma requiring adjuvant therapy.

Animals↗
PubMed2005

Chromosomal and genetic abnormalities in benign and malignant meningiomas using DNA microarray.

BACKGROUND: Meningioma is the commonest brain tumor and many genetic abnormalities, such as the loss of chromosome 22q and the mutation of NF2, have been reported. METHODS: These classical abnormalities were detected using Southern blot, PCR, fluorescence in situ hybridization and comparative genomic hybridization, but these methods examine only very limited regions or limited mapping resolution of the tumor genome. In this study, we used DNA microarray assay, which detects numerous genetic abnormalities simultaneously and analyses a global assessment of molecular events in meningioma cells. We studied 31 meningiomas by GenoSensor Array 300 in order to detect the chromosomal aberrations and genetic abnormalities in the whole genome. RESULTS: This study demonstrated not only classical chromosomal aberration, such as loss of chromosome 22q in 19 meningiomas (61.3%), but also new genetic characteristics of meningiomas, such as amplification of MSH2 in 16 meningiomas (51.6%), deletion of GSCL in 13 meningiomas (41.9%) and deletion of HIRA in seven meningiomas (22.6%). CONCLUSIONS: These results suggest that DNA microarray assay is useful in research for the genetic characters of meningiomas and understanding tumorigenesis.

Adolescent↗
PubMed2005

Continuous intrathecal administration of 5-fluoro-2'-deoxyuridine for the treatment of neoplastic meningitis.

OBJECTIVE: Previously, we reported a good clinical treatment effect of intrathecal chemotherapy by repeated bolus administration of 5-fluoro-2'-deoxyuridine (FdUrd) for neoplastic meningitis (NM). Moreover, we detected no side effects or neurotoxicity despite the long-term repetition of intrathecal administration. On the basis of these findings, continuous intrathecal chemotherapy (CIC) with FdUrd for patients with NM was attempted using a simple pump system. We evaluated the usefulness of CIC with FdUrd for the treatment of NM. METHODS: A total of 25 patients were enrolled in this study. FdUrd (1.0 mg/d) was administered using a balloon pump system. CIC was continued as long as possible. Eight patients received whole-brain irradiation (3 Gy x 10) simultaneously with CIC. The effects of the treatment were analyzed in terms of improvement in neurological signs and symptoms and the findings of ventricular and lumbar cerebrospinal fluid analysis 2 and 4 weeks after CIC was initiated and on magnetic resonance imaging scans 2 months after CIC began. RESULTS: No apparent toxicity has been observed to date. Evidence of a cerebrospinal fluid response was observed in 13 patients. Headache and nausea were improved in all patients, and cranial nerve impairment was improved in 12 patients. A magnetic resonance imaging response was observed in only 5 patients. Overall response was observed in 15 patients when cases of stable disease were excluded from the responding cases. Survival time from the commencement of CIC (mean +/- standard error of the mean) was 255 +/- 30 days in 25 patients. CONCLUSION: This therapy may be useful, especially as a maintenance therapy for NM.

Adult↗
PubMed2004

Genetic analysis of human glioblastomas using a genomic microarray system.

Genomic microarray systems can simultaneously provide substantial genetic and chromosomal information in a relatively short time. We have analyzed genomic DNA from frozen sections of 30 cases of primary glioblastomas by GenoSensor Array 300 in order to characterize gene amplifications, gene deletions, and chromosomal information in the whole genome. Genes that were frequently amplified included RFC2/CYLN2 (63.3%), EGFR (53.3%), IL6 (53.3%), ABCB1 (MDR1) (36.7%), and PDGFRA (26.7%). Genes that were frequently deleted included (56.7%), FGFR2 (66.7%), MTAP (60.0%), DMBT1 CDKN2A (p16)/MTAP (50.0%), PIK3CA (43.3%), and EGR2 (43.3%), but deletion of RB1 or TP53 was rarely detected. Chromosomal gains were observed frequently for 7q (33.3%), 7p (20.0%), and 17q (13.3%). Loss of the 10q was frequently detected in 13 of 30 cases (46.7%). Loss of the entire chromosome 10 was seen in 9 of 30 cases (30.0%), and was often accompanied by EGFR amplification (7 cases, 77.8%). The GenoSensor Array 300 proved to be useful for identification of genome-wide molecular changes in glioblastomas. The obtained microarray profile can also yield valuable insight into the molecular events underlying carcinogenesis of brain tumors and may provide clues about clinical correlations, including response to treatment.

Adult↗
PubMed2004

Chromosomal and genetic aberrations differ with meningioma subtype.

Meningioma is one of the most common brain tumors, and a variety of genetic abnormalities have been detected by the Southern blotting, polymerase chain reaction (PCR), fluorescence in situ hybridization (FISH), and comparative genomic hybridization (CGH) methods. However, these methods detect only a very limited portion of the tumor genome or have a limited mapping resolution. In this study, we used DNA microarray assay, which detects numerous genetic abnormalities and analyzes a global assessment of molecular events in tumor cells. We analyzed genomic DNA from 26 patients with benign meningiomas by GenoSensor Array 300 in order to characterize gene amplifications, gene deletions, and chromosomal information in the whole genome. Loss of chromosome 22q was found most frequently. This chromosomal aberration was detected in 14 meningiomas (53.8%), particularly in transitional and fibrous meningiomas. In meningothelial meningiomas, amplification of INS and TCL1A was detected more frequently than in other meningioma subtypes. DNA microarray assay revealed new genetic differences among the meningioma subtypes, thus indicating that this novel technique is useful for understanding tumor genesis and for the diagnosis of meningioma subtype.

Adolescent↗
PubMed2004

Overexpression of the Wilms' tumor gene W T1 in primary astrocytic tumors.

Expression of the Wilms' tumor gene W T1 in primary astrocytic tumors was examined using a quantitative real-time reverse transcriptase-polymerase chain reaction (RT-PCR) or immunohistochemistry. Real-time RT-PCR showed that W T1 mRNA was expressed at various levels in all of the 25 astrocytic tumors examined. Immunohistochemical analysis showed that W T1 protein was expressed in 5 of 6 low-grade astrocytic tumors (grade I-II) and all of 18 high-grade ones (grade III-IV), and that expression levels of W T1 protein in high-grade tumors were significantly higher than those in low-grade ones. W T1 protein was not detected in the normal glial cells contained in the tumor specimens. Furthermore, treatment with W T1 antisense oligomers specifically inhibited growth of glioblastoma cell lines, U87-MG, A172, and T-98G. These results may indicate that the W T1 gene plays an important role in tumorigenesis of primary astrocytic tumors.

Adolescent↗
PubMed2003

Clinical significance of prolonged P wave width after right atrial appendage pacing in sick sinus syndrome.

The present study investigated both the clinical significance of atrial fibrillation (AF) before right atrial appendage (RAA) pacing and the influence of prolonged P wave on AF occurrence in RAA-paced patients with sick sinus syndrome (SSS). Fifty-seven patients (age 68+/-10 years; 19 men, 38 women) with SSS who underwent RAA pacing were divided into 2 groups: 23 patients without AF before pacing (I + II; Rubenstein I or II) and 34 patients with AF before pacing (III; Rubenstein III). The P wave duration in intrinsic rhythm and with RAA pacing were measured on the standard electrocardiography in leads II and V(1) with the use of a digitizing tablet. Group III was further subdivided into 2 groups: 20 patients (IIIb) with a paced P wave >130 ms in both leads II and V(1) and the other 14 patients (IIIa). The duration of the intrinsic P wave in leads II and V(1) was significantly greater in group III than in group I + II (119+/-20 vs 108+/-21 ms, p=0.0417, 106+/-16 vs 95+/-21 ms, p=0.0258, respectively). During the follow-up of 40+/-21 months, AF recurrence was significantly higher in group IIIb than in groups IIIa and I + II (17/20 vs 5/14 vs 2/23 p<0.0001). A few occurrences of AF were observed by conventional RAA pacing in patients without AF before pacing. However, SSS with AF before pacing caused a significant intra-atrial conduction disturbance and a high incidence of AF recurrence after implantation of RAA pacing, especially in patients with a prolonged paced P wave, in whom new pacing modalities may be needed to shorten paced P wave duration and prevent AF.

Aged↗
PubMed2003

Hemodynamics during chronic amiodarone administration in Japanese patients with idiopathic dilated cardiomyopathy and ventricular arrhythmia: a retrospective study.

OBJECTIVES: Nonischemic heart disease, especially idiopathic dilated cardiomyopathy, is relatively common among Japanese patients receiving amiodarone for concomitant ventricular arrhythmia, but the hemodynamic effects of amiodarone in these Japanese patients are unclear. The hemodynamic changes during chronic amiodarone administration were retrospectively studied in patients with idiopathic dilated cardiomyopathy and ventricular arrhythmia. METHODS: Fifty-two patients [42 males, 10 females, 53 +/- 2 years (mean age +/- SE)] with ventricular tachyarrhythmia and idiopathic dilated cardiomyopathy with left ventricular ejection fraction of 27 +/- 1% (mean +/- SE) were treated with 200-400 mg daily of oral amiodarone as the loading dose for the initial 14 days and 100-200 mg daily maintenance dose for a further 6 months. No patients were taking beta-blockers or positive inotropic drugs. Echocardiographic examination was performed before (baseline), at week 2 and at month 6 of amiodarone therapy. Twenty four-hour Holter monitoring during the same time period was also performed in 34 patients. Seventeen patients underwent right heart catheterization before and at week 2. RESULTS: Echocardiographic measurements showed no significant change in left ventricular end-diastolic dimension, although there was a slight increase in fractional shortening from 16 +/- 1% to 19 +/- 1% (p < 0.05) and 18 +/- 1% (mean +/- SE) (p < 0.01) at week 2 and month 6 of amiodarone therapy, respectively. Amiodarone markedly reduced the mean heart rate and the frequency of premature ventricular complexes on ambulatory monitoring. The cardiac index did not change and the pulmonary capillary wedge pressure tended to decrease slightly at week 2 in the 17 patients who underwent catheterization. CONCLUSIONS: This retrospective study showed no worsening of the hemodynamic state during chronic amiodarone administration in Japanese patients with idiopathic dilated cardiomyopathy and ventricular arrhythmia.

Adult↗
PubMed2003

[Results of prophylactic hepatic arterial chemotherapy for liver metastases of Dukes C colorectal cancer--correlation with tumoral expression of dihydropyrimidine dehydrogenase, thymidylate synthase, p53, or orotate phosphoribosyl transferase].

The purpose of this study was (1) to disclose data from a non-randomized trial of prophylactic hepatic arterial chemotherapy for liver metastases from Dukes'C colorectal cancer, (2) to examine the influence of the expression of dihydropyrimidine dehydrogenase (DPD), thymidylate synthase (TS), and p53 in the primary lesion on this chemotherapy, and (3) to examine the expression of orotate phosphoribosyl transferase (OPRT) mRNA levels in the cases of recurrence included in this study. Patients who underwent curative resection of Dukes'C colorectal cancer between November 1996 and April 2000 were examined. After curative resection, patients were non-randomly divided into two groups after obtaining their informed consent: Hepatic arterial infusion (HAI) group patients (n = 28) were given 5-FU (500 mg/body for 1 h per week, repeated 50 times) via the hepatic artery and peroral UFT-E after resection of Dukes'C colorectal cancer. Control group patients (n = 21) received UFT-E alone. Liver metastasis-free survival did not differ between the groups. Immunohistochemical examinations revealed that the expression of tumoral DPD or p53 was unlikely to affect the hepatic recurrence, although patients with a low expression of TS tended to have better survival in both groups. However, multivariate analysis by the Cox proportional hazard model revealed that a significant prognostic factor influencing the hepatic recurrence is extensive venous invasion. Expression levels of OPRT mRNA, measured in tumors of patients with recurrence (n = 6 for the HAI group; and n = 4 for the control group) were not significantly different between the groups. These results suggest that (1) intermittent hepatic arterial infusion of 5-FU in addition to oral UFT-E was not more useful than administration of UFT alone, and (2) the expression of DPD, TS, p53, and OPRT in the primary lesion was unlikely to affect the prognosis of patients included in this study.

Adult↗
PubMed2002

Primary thyroid carcinoma found with esophageal stenosis: report of a case.

The typical symptoms of primary thyroid cancer are a cervical mass and cervical lymphadenopathy, while dyspnea, hoarseness, or dysphagia can occur in the presence of extrathyroidal involvement. Esophageal involvement or stenosis causing dysphagia without any influence on the trachea is rare because of the anatomical location of the esophagus and the trachea. We report herein a case of primary thyroid carcinoma advancing behind the esophagus with the trachea intact, which was difficult to diagnose by esophagoscopy or roentgenogram. Thus, thyroid tumors need to be differentiated from other possible causes of esophageal stenosis. Computed tomography, magnetic resonance imaging, and ultrasonography are useful diagnostic modalities to detect thyroid tumors causing esophageal stenosis.

Deglutition Disorders↗
PubMed2002

Postoperative modified stereotactic radiotherapy using a micro-multileaf collimator in patients with malignant glioma.

To achieve local control of malignant glioma, we designed a postoperative stereotactic radiotherapy using a micro-multileaf collimator (micro-MLC). The purpose of this study was to clarify the feasibility of this treatment. The treatment was performed in six patients who met the following eligibility criteria: (1) supratentorial tumor, (2) residual tumor volume < or = 40 cm3, and (3) Karnofsky performance status > or = 70. The three planning target volumes (PTVs), which consisted of restricted PTV (RPTV), intermediate PTV (IPTV), and extended PTV (EPTV), defined as the residual tumor plus a 1 cm, 2 cm, and 3 cm margins, respectively, and total dose delivery of 60-68 Gy, 52-60 Gy, and 44-52 Gy to the isocenters of RPTV, IPTV, and EPTV, respectively, in 4 Gy per fraction at five fractions per week, were established. The beam arrangement and the conformal blockade with a micro-MLC for the optimal treatment plan were designed. The treatment plans showed the high dose conformation to EPTV, the appropriate dose gradients in the three PTVs with the high dose homogeneity to RPTV, and the tolerated dose to critical structures. Following the plans, treatment was performed. The clinical findings more than 12 months after the treatment supported its possible use. We conclude that this treatment is feasible at least in selected patients.

Adult↗
PubMed2002

Effect of low-dose amiodarone on atrial fibrillation or flutter in Japanese patients with heart failure.

The efficacy and safety of amiodarone in the management of atrial fibrillation (AF) or flutter in 108 Japanese patients with heart failure was retrospectively examined. Thirty-four (41%) of the 82 patients who were in sinus rhythm after 1 month of amiodarone administration had their first recurrence, 70% of cases occurring within 1 year of initiation. The cumulative rates of maintenance of sinus rhythm were 0.68, 0.55, and 0.47 at 1, 3, and 5 years, respectively. Amiodarone was more effective in maintaining sinus rhythm in patients with paroxysmal AF or flutter than in those with the persistent form (p<0.05). The cumulative rates for cases that remained in permanent AF were 0.04, 0.11, and 0.14 at 1, 3, and 5 years, respectively. Apart from suppressing AF, the mean heart rate during Holter monitoring was significantly decreased with amiodarone therapy in cases of permanent AF. Adverse effects requiring the discontinuation of amiodarone therapy occurred in 16% of patients. Low-dose amiodarone therapy may prevent AF or flutter in Japanese patients with heart failure.

Amiodarone↗