Biomedical subjects

Kazunori Suzuki

Publications and source records attributed to Kazunori Suzuki.

16 recordsLinked to original sources

PubMed2007

Pilot study of ifosfamide/carboplatin/etoposide (ICE) for peripheral blood stem cell mobilization in patients with high-risk or relapsed medulloblastoma.

OBJECTIVES: The purpose of this study is to evaluate the stem cell mobilization capacity, anti-tumor effect, and feasibility of ifosfamide/carboplatin/etoposide (ICE) for transplant-eligible patients with medulloblastoma. MATERIALS AND METHODS: Six patients (23 months to 18 years old) with high-risk or relapsed medulloblastoma received one cycle of ICE, which consisted of ifosfamide at 1.8 g/m(2) for 5 days, carboplatin 400 mg/m(2) for 2 days, and etoposide 100 mg/m(2) for 5 days. Stem cells were mobilized with ICE followed by granulocyte colony-stimulating factor at 10 microg kg(-1) day(-1). RESULTS: After one cycle of ICE, the median number of harvested CD34+ cells per apheresis session was 11.85 x 10(6) cells/kg (range, 0.2 to 71.2 x 10(6) cells/kg). Two patients obtained a complete response and three patients a partial response. All patients experienced severe myelosuppression, and three infectious toxicities were observed. CONCLUSIONS: These results suggest that ICE is optimal for mobilizing stem cells, effective for high-risk or relapsed medulloblastoma, and tolerable with limited non-hematological toxicity.

Adolescent↗

PubMed2006

Multi-institutional study of radiation therapy for isolated para-aortic lymph node recurrence in uterine cervical carcinoma: 84 subjects of a population of more than 5,000.

PURPOSE: Most patients who had any recurrent sites of cancer have been considered to be in their last stage of life. However, recent advances of clinical research reveal some patients achieve long-term survival even in recurrence. Furthermore, for patients who had only one recurrent region, radiation therapy could play an important role. As for uterine cervical carcinoma, the most common recurrent site other than the pelvis is the para-aortic lymph nodes. Thus we conducted the current study. PATIENTS AND METHODS: Between 1994 and 2003, more than 5,000 uterine cervical carcinoma patients were treated with curative intended treatments at 13 Japanese hospitals. Of these patients, 84 developed para-aortic lymph node recurrence as the only site of initial tumor progression. These patients were treated with external beam radiation therapy. Radiation therapy protocol was as follows: 1.7-2.0 Gy per fraction, 5 fractions per week, and the mean total dose was 50.8 Gy (25-60 Gy). RESULTS: Three- and 5-year overall survival rates of all patients were 49.5% and 31.3%, respectively. Stratified by symptom sign, 3-year overall survival rate of symptom positive was 27.6% and those of the negative was 56.1% (p = 0.018). Three-year overall survival rates of the total dose > or =51 Gy and that of < or =50 Gy were 58.0% and 42.8%, respectively (p = 0.07). As for morbidity, no patients received Grade 3 or greater late toxicity. CONCLUSIONS: The current study suggested that radiation therapy for isolated para-aortic lymph node recurrence in uterine cervical carcinoma could have a significant impact on survival.

Adult↗

PubMed2006

Frequency and characteristics of isolated para-aortic lymph node recurrence in patients with uterine cervical carcinoma in Japan: a multi-institutional study.

OBJECTIVE: In most cases of uterine cervical carcinoma recurrence, the first site of distant metastasis or recurrence is reported to be the para-aortic region. Some reports have demonstrated that, in cases of isolated para-aortic lymph node recurrence treated by radiation therapy, patients survived for a long period, which suggests that isolated para-aortic lymph node recurrence in uterine cervical carcinoma is a regional disease rather than systemic disease. Determining the predictive characteristics of isolated para-aortic lymph node recurrence in patients at the time of the initial treatment for primary uterine cervical carcinoma is important, so we conducted the current multi-institutional study. PATIENTS AND METHODS: Patients (n=3137) with uterine cervical carcinoma of stages Ia to IVa were treated in twelve Japanese hospitals between 1994 and 2003. The current study investigated the frequency and characteristics of patients with isolated para-aortic lymph node recurrence as well as the characteristics of clinical stage, histopathology, serum squamous cell carcinoma antigen level, the treatment method at the initial treatment, the duration between the initial treatment and the recurrence, and the serum squamous cell carcinoma antigen level at the recurrence. RESULTS: Of the 3137 patients with uterine cervical carcinoma in stages Ia-IVa, 67 (2.1%) experienced recurrence in isolated para-aortic lymph nodes. Stratified by clinical stage, none of the 613 patients with stage Ia experienced recurrence in isolated para-aortic lymph nodes. However, recurrence was experienced by 14 (1.4%) of the 966 patients with stage Ib, 7 (3.5%) of the 199 patients with stage IIa, 14 (2.3%) of the 613 patients with stage IIb, 1 (2.1%) of the 48 patients with stage IIIa, 26 (4.6%) of the 538 patients with stage IIIb, and 5 (5%) of the 100 patients with stage IVa. The mean duration time between the initial treatment and isolated para-aortic recurrence was 20 months (range, 2-49 months). The correlations between duration time and the clinico-pathological factors (clinical stage, histopathology, serum squamous cell carcinoma antigen level, and treatment method) at the initial treatment were investigated. No statistically significant factors have been revealed in the current study. CONCLUSIONS: The frequency of isolated para-aortic lymph node recurrence was 2.1% and increased with increasing clinical stage at the initial treatment (stage IVa: 5%) in the current study.

Adult↗

PubMed2006

Microbiological analysis and endoanal ultrasonography for diagnosis of anal fistula in acute anorectal sepsis.

BACKGROUND AND AIMS: Treatment of anorectal sepsis requires prompt surgical drainage, but it is important to identify any associated anal fistula for preventing recurrence. We evaluated whether microbiological analysis and/or endoanal ultrasonography could be used to predict anal fistula in patients with acute anorectal sepsis. METHODS: Five hundred fourteen consecutive patients with acute anorectal sepsis were studied. Clinical data, digital examination findings, endosonographic findings, and results of microbiological analysis were compared with definitive surgical findings of the presence or absence of anal fistula. RESULTS: Anorectal abscess with anal fistula was found in 418 patients, and anorectal abscess without anal fistula was found in 96 patients. Microbiological examination showed that Escherichia coli, Bacteroides, Bacillus, and Klebsiella species were significantly more prevalent in patients with fistula (P<0.01), and coagulase-negative Staphylococci and Peptostreptococcus species were significantly more prevalent in patients without fistula (P<0.01). Results of endoanal ultrasonography were concordant with the definitive surgical diagnosis in 421 (94%) of 448 patients studied. CONCLUSION: Acute anorectal sepsis due to colonization of "gut-derived" microorganisms rather than "skin-derived" organisms is more likely to be associated with anal fistula. When the microbiological analysis yields gut-derived bacteria, but no fistula has been found in the initial drainage operation, repeat examinations during a period of quiescence, including careful digital assessment and meticulous endosonography, are warranted to identify a potentially missed anal fistula.

Abscess↗

PubMed2006

Postoperative urinary retention after surgery for benign anorectal disease: potential risk factors and strategy for prevention.

PURPOSE: This study was undertaken to determine the incidence of and risk factors for urinary retention after surgery for benign anorectal disease. METHODS: We reviewed 2,011 consecutive surgeries performed under spinal anesthesia for benign anorectal disease from January through June 2003 to identify potential risk factors for postoperative urinary retention. In addition, we prospectively investigated the preventive effect of perioperative fluid restriction and pain control by prophylactic analgesics on postoperative urinary retention. RESULTS: The number of procedures and the urinary retention rates were as follows: hemorrhoidectomy, 1,243, 21.9%; fistulectomy, 349, 6.3%; incision/drainage, 177, 2.3%; and sliding skin graft/lateral subcutaneous internal sphincterotomy, 64, 17.2%. The overall urinary retention rate was 16.7%. With hemorrhoidectomy, female sex, presence of preoperative urinary symptoms, diabetes mellitus, need for postoperative analgesics, and more than three hemorrhoids resected were independent risk factors for urinary retention as assessed by multivariate analysis. With fistulectomy, female sex, diabetes mellitus, and intravenous fluids >1,000 ml were independent risk factors for urinary retention. Perioperative fluid restriction, including limiting the administration of intravenous fluids, significantly decreased the incidence of urinary retention (7.9 vs 16.7%, P<0.0001). Furthermore, prophylactic analgesic treatment significantly decreased the incidence of urinary retention (7.9 vs 25.6%, P=0.0005). CONCLUSIONS: Urinary retention is a common complication after anorectal surgery. It is linked to several risk factors, including increased intravenous fluids and postoperative pain. Perioperative fluid restriction and adequate pain relief appear to be effective in preventing urinary retention in a significant number of patients after anorectal surgery.

Adult↗

PubMed2006

Expression profile of BDNF-responsive genes during cerebellar granule cell development.

With the aid of microarray and PCR analysis, this investigation sought expression profiles of BDNF-regulated genes in cultured mouse cerebellar granule cells and addressed their relevance to gene regulation in developing granule cells in vivo. Many of the BDNF-upregulated and downregulated genes identified were upregulated and downregulated, respectively, during cerebellar development. This developmental change was, at least partly, prevented in the TrkB receptor-deficient cerebellum. The BDNF-upregulated genes were distributed in either postmigratory or both premigratory and postmigratory granule cells at postnatal day 8 (P8) and were still present in mature granule cells at P21. In contrast, the BDNF-downregulated genes were predominantly expressed in premigratory granule cells at P8 and disappeared at P21. Furthermore, many of the BDNF-upregulated gene products are implicated in signaling cascades of N-methyl-D-aspartate receptors and MAP kinase. The results indicate that BDNF signaling plays a pivotal role in promoting gene expression in granule cell development and maturation.

Animals↗

PubMed2006

Results of primary central nervous system lymphoma treated by radiation and chemotherapy: retrospective analysis of twelve institutions in the Tokai District of Japan, 1995-1999.

PURPOSE: We analyzed the therapeutic results and prognostic factors of 46 primary central nervous system lymphoma (PCNSL) patients who were treated at twelve institutions in the Tokai district of Japan between 1995 and 1999. We compared the results with those of a Japanese nationwide survey performed in the past. MATERIALS AND METHODS: We sent each institution a questionnaire about the state of patients' disease, pathological type, method and doses of radiotherapy, regimen and intensity of chemotherapy, and patients' prognoses. The range of patients' ages was 33 to 93 years (median, 61 years). Thirty-one were men and 15 were women. The most prevalent histology was diffuse large B cell type (33 patients). We used the Kaplan-Meier method to calculate the survival rate and Cox's proportional hazards model to analyze the prognostic factors. RESULTS: The five-year cumulative survival rate was 25%, and the median survival time was 22.7 months. The five-year disease-free survival rate was 23%. In monovariate analysis, patients who were both younger than 60 years old and had a WHO performance status (PS) score equal to or less than 2 showed a better survival rate. Furthermore, the patients receiving systemic chemotherapy showed a significantly better local control rate. In addition, patients who received systemic chemotherapy achieved a higher complete remission rate than those not receiving it. However, no factors that significantly influenced survival rate were identified in multivariate analysis. CONCLUSION: We demonstrated that the therapeutic outcome of PCNSL patients has recently improved. In particular, patients with good PS showed better local control than those with poor PS. However, we could not identify any significant prognostic factors in PCNSL patients.

Adult↗

PubMed2005

Neuronal depolarization controls brain-derived neurotrophic factor-induced upregulation of NR2C NMDA receptor via calcineurin signaling.

In the developing cerebellum, switching of subunit composition of NMDA receptors occurs in granule cells from NR2B subunit-containing receptors to NR2C subunit-containing receptors. This switching of subunit composition plays an important role in the establishment of functional mossy fiber-granule cell synaptic transmission in the mature cerebellar network. The mechanism underlying NR2C upregulation in developing granule cells, however, has to date remained to be determined. In granule cells cultured in low (5 mm) KCl, brain-derived neurotrophic factor (BDNF) upregulated NR2C mRNA via the TrkB-extracellular signal-regulated kinase (ERK) 1/2 cascade and promoted the formation of an NR2C-containing NMDA receptor complex. In granule cells cultured in high (25 mm) KCl, depolarization stimulated voltage-sensitive Ca2+ channels. The resultant increase in intracellular Ca2+ activated Ca2+/calmodulin-dependent calcineurin phosphatase and blocked NR2C mRNA upregulation. Interestingly, the depolarization-induced Ca2+ increase simultaneously upregulated BDNF mRNA via Ca2+/calmodulin-dependent protein kinase (CaMK). Consequently, when calcineurin was inhibited by its inhibitor FK506 under the depolarizing condition, the CaMK-mediated increase in BDNF became a stimulatory signal, and the endogenous BDNF autocrine system was capable of upregulating NR2C mRNA via the common TrkB-ERK cascade. The importance of the BDNF-TrkB pathway was further supported by a significant reduction in NR2C in normally migrated granule cells of TrkB(-/-) knock-out mice in vivo. The convergent mechanism of the BDNF and Ca2+ signaling cascades thus plays an important regulatory role in NR2C induction in granule cells during cerebellar development.

Animals↗

PubMed2005

CNS germinoma with elevated serum human chorionic gonadotropin level: clinical characteristics and treatment outcome.

PURPOSE: The prognostic significance of human chorionic gonadotropin (HCG) level in central nervous system germinoma remains controversial. The purpose of this study was to compare clinical characteristics and prognosis of germinoma patients with normal and high HCG titers in the serum. METHODS AND MATERIALS: We undertook a multi-institutional retrospective analysis of 103 patients with central nervous system germinoma whose serum HCG and/or beta-HCG level had been measured before treatment between 1984 and 2002. All patients had been treated with radiation therapy either alone (n = 66) or in combination with chemotherapy (n = 37) with a median dose of 47.8 Gy. RESULTS: HCG and/or beta-HCG level in the serum was high in 39% of all patients. The proportion of HCG-producing tumors was higher in the lesions at the basal ganglia than in the lesions at the other sites. No correlation was found between tumor size and HCG level, but there seemed to be a weak correlation between size and beta-HCG. The 5- and 10-year survival rates were 96% and 94%, respectively, in both patient groups with normal and high HCG (p = 0.99). The 5- and 10-year relapse-free survival rates were 87% and 82%, respectively, in patients with normal HCG level and were both 87% in patients with high HCG (p = 0.74). Also, no other patient-, tumor-, or treatment-related factors seemed to influence the prognosis of the patients. CONCLUSION: Serum HCG level does not seem to influence patient prognosis when treated with sufficient doses of radiation. Relationship between tumor size and site and HCG level should be investigated further.

Adolescent↗

PubMed2005

Results of radiation monotherapy for primary central nervous system lymphoma in the 1990s.

PURPOSE: Results of radiation therapy for primary central nervous system lymphoma (PCNSL) were poor in the 1970-1980s, with most reported 5-year survival rates being less than 10%. To investigate whether the prognosis of PCNSL patients treated by radiation alone remains still poor, we investigated the results of radiation monotherapy in the 1990s. METHODS AND MATERIALS: We collected data on 132 patients with histologically proven PCNSL treated by radiation alone in the 1990s from three nationwide or regional multiinstitutional studies conducted by the Japanese Society for Therapeutic Radiology and Oncology (JASTRO) Lymphoma Study Group or the Chubu Radiation Oncology Group. Follow-up data were updated as far as possible. Eleven patients who did not complete planned radiotherapy were included. The data were analyzed in relation to patient and tumor characteristics. The median patient age was 63 years, and the World Health Organization performance status (PS) was 3 or 4 in 40% of the patients. Multiple tumors were seen in 34%. Whole-brain irradiation with or without focal boost was used in 92%. The median radiation dose to the tumor site was 50 Gy (range, 8-74 Gy). RESULTS: For all 132 patients, the median survival time was 18 months and the 5-year survival rate was 18.0%. For 62 patients with PS 0-3 and aged 16-65 years (i.e., those eligible for the European Organization for Research and Treatment of Cancer 20962 study), the median survival was 26 months and 5-year survival was 24%. The 5-year survival was 25% for patients 63 years old or younger, and 9.8% for those older than 63 years (p = 0.0005). The 5-year survival was 22% for patients with PS 0-2 and 13% for those with PS 3 or 4 (p = 0.0040). Multivariate analysis confirmed the negative influence of higher age on patient prognosis. CONCLUSIONS: The results of radiation monotherapy for PCNSL appear to have improved as compared with those reported previously. The results of new treatment should be evaluated in light of this finding. Since most prospective studies on the combined treatment exclude poor PS and high-age patients, the 5-year survival rate of 30% may not be regarded as a marked improvement over radiation alone.

Adolescent↗

PubMed2005

A pivotal role of calcineurin signaling in development and maturation of postnatal cerebellar granule cells.

Primary culture of postnatal cerebellar granule cells provides a model system that recapitulates many molecular events of developing granule cells in vivo. Depolarization of cultured granule cells increases intracellular Ca(2+) and activates Ca(2+)/calmodulin-dependent calcineurin (CaN) phosphatase. This Ca(2+) signaling mimics some of the signaling events for proliferation, migration, and differentiation of granule cells in vivo. We investigated the genome-wide expression profiles of depolarization- and CaN-regulated genes in cultured mouse granule cells and addressed their relevance to gene regulation in developing granule cells in vivo. Granule cells were cultured under a nondepolarization condition (5 mM KCl) and a depolarization condition (25 mM KCl) with and without the CaN inhibitor FK506. Gene expression profiles between depolarization and nondepolarization and between FK506 treatment and untreatment were analyzed by microarray techniques. Both depolarization and FK506 treatment influence expression levels of a large number of genes, most of which are overlapping, however, are conversely regulated by these two treatments. Importantly, many of the FK506-responsive genes are up- or down-regulated in parallel with gene expression in postnatal granule cells in vivo. The FK506-down-regulated genes are highly expressed in proliferating/premigratory granule cells and many of these genes encode cellular components involved in cell proliferation, migration, and differentiation. In contrast, the FK506-up-regulated genes are predominantly expressed in postmigratory granule cells, including many functional molecules implicated in synaptic transmission and modulation. This investigation demonstrates that the CaN signaling plays a pivotal role in development and synaptic organization of granule cells during the postnatal period.

Animals↗

PubMed2005

Imaging of water distribution in thermally fractured granites by SPRITE.

Water distribution in thermally fractured granite samples was visualized by using SPRITE sequences. Networks of intergranular fractures were observed in the coarse-grained Inada granite after heating at 873 K or above. On the other hand, bright spots were observed in the fine-grained Okazaki granite, which may be due to pore water in feldspar grains. D2O diffusion into samples saturated with H2O was also observed by 2D-projected SPRITE imaging.

Diffusion↗

PubMed2004

Effects of acetazolamide and 4-aminopyridine on CO2-induced slowly adapting pulmonary stretch receptor inhibition in rats.

Inhibitory responses of slowly adapting pulmonary stretch receptor (SAR) activity to CO(2) inhalation (maximal tracheal CO(2) concentration ranging from 9.5 to 12.5%) for approximately 60 s were examined before and after administration of acetazolamide (a carbonic anhydrase inhibitor) or 4-aminopyridine (4-AP, a K(+) channel blocker). The experiments were performed in 35 anesthetized, artificially ventilated rats after unilateral vagotomy. Sixty-eight of eighty-four SARs were inhibited by CO(2) inhalation. The SAR inhibition was attenuated by pretreatment with either acetazolamide (20 mg/kg, n = 10) or 4-AP (0.7 and 2.0 mg/kg, n = 10). In other series of experiments, stainings to show the existence of carbonic anhydrase (CA) enzymatic reaction were not found in the smooth muscle of either extrapulmonary or intrapulmonary bronchi. Protein gene product 9.5 (PGP 9.5)-immunoreactive SAR terminals to form leaflike extensions were found in the bronchioles at different diameters and were smooth-muscle-related receptors. But in the same sections, CA isozyme II-like (erythrocyte CA) immunoreactive SAR terminals were not identified. These results suggest that CO(2)-induced inhibition of SARs may be involved in the CA-dependent CO(2) hydration in addition to the activation of 4-AP sensitive K(+) currents.

4-Aminopyridine↗

PubMed2004

The incidence and clinical characteristics of bronchiolitis obliterans organizing pneumonia syndrome after radiation therapy for breast cancer.

STUDY OBJECTIVE: Bronchiolitis obliterans organizing pneumonia (BOOP) syndrome after adjuvant radiation therapy for breast cancer has been recently recognized. However, the precise incidence of this syndrome remains to be determined. The aim of this study was to clarify the incidence and clinical characteristics of radiation-induced BOOP syndrome. METHODS: We conducted a retrospective analysis of 206 consecutive patients wit breast cancer undergoing tangential-field radiation therapy at our institution from 1992 to 2002. RESULTS: Among the patients, five (2.4%) developed BOOP syndrome. These five patients began with flu-like symptoms 2-7 months after the completion of radiation therapy. Four of them had received tamoxifen, an estrogen receptor antagonist, and the other one underwent cytotoxic chemotherapy. Their chest radiographs revealed peripheral alveolar opacities with migration outside the irradiated fields. Increased lymphocyte counts and elevated CD4/CD8 ratios were observed in the bronchoalveolar lavage fluid. Transbronchial biopsy revealed organizing pneumonia. The serum levels of KL-6, a marker of interstitial pneumonia, did not increase in any patients. Treatment with corticosteroids resulted in a rapid improvement, but two patients relapsed after the cessation of corticosteroids. CONCLUSIONS: These results suggest that BOOP syndrome after tangential-field radiation therapy for breast cancer is not rare and more attention should be directed to this condition as a radiation-induced pulmonary toxicity.

Biopsy↗

PubMed2003

Hepatobiliary cystadenoma with mesenchymal stroma in a patient with chronic hepatitis C.

Hepatobiliary cystadenoma was suggested to be uncommon and it is often difficult to make a differential diagnosis. We report a case of a 65-year-old woman who presented with changes in the structure of a cyst that had been observed for the previous 10 years. Diagnostic imaging revealed a 7-cm-diameter cystic lesion with internal septations and papillary projections in her liver. All laboratory test results were normal; however, cystic fluid carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 were raised, at 160 ng/ml andover 200,000 U/ml, respectively. Owing to changes in the structure of the cyst and the difficulty of differential diagnosis from cystadenocarcinoma, a complete surgical excision was performed. The histological findings indicated that the tumor consisted of a multilocular cyst lined by glandular cells (with cuboidal or tall columnar cystoplasm), which were immunohistochemically positive for cytokeratin, CEA, epithelial membrane antigen, and CA 19-9. The underlying stroma was composed of proliferating primitive spindle cells which were immunoreactive for vimentin, alpha-smooth muscle actin, muscle-specific actin, and desmin, and resembled ovarian stroma. From these findings, this tumor was diagnosed as hepatobiliary cystadenoma with mesenchymal stroma. Even though the tumor was previously diagnosed as a simple liver cyst, it was necessary to pay special attention to the changes in the structure of the cyst, using ultra sonography and/or computed tomography, bearing in mind hepatobiliary cystadenoma with mesenchymal stroma. The malignant potential of this tumor is stressed, and complete surgical resection is the recommended therapy.

Aged↗

PubMed2000

Recent progress in soliton transmission technology.

Recent progress on time-division multiplexed (TDM) and wavelength-division multiplexed (WDM) soliton transmission is described, in which dispersion management plays an important role in increasing the power margin and the dispersion tolerance. The characteristics of the dispersion-managed soliton are compared with those of return to zero and nonreturn to zero pulses. With a small dispersion swing, the system can still be described as an average soliton using the nonlinear Schrodinger equation, while with a large dispersion swing, the solitonlike steady-state pulse becomes a chirped Gaussian pulse, in which the governing equation is closer to a linear Schrodinger equation with a parabolic potential well. We describe an in-line modulation scheme for up to 80 Gbit/s per channel and its two channel WDM transmission over 10 000 km. Finally, we describe 640 Gbit/s (40 Gbit/sx16 channels) WDM soliton transmission over 1000 km with a dispersion-managed single-mode fiber. (c) 2000 American Institute of Physics.

Journal Article↗