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Biomedical subjects

N Shimizu

Publications and source records attributed to N Shimizu.

At least 91 records · Page 5Linked to original sources
PubMed2001

Intrapulmonary lymph nodes enlarged after lobectomy for lung cancer.

A 62-year-old man, who had had a left upper lobectomy for mucoepidermoid lung carcinoma, was admitted again 3 months later because of enlargement of four small nodules in the left lower lobe. A computed tomography-guided needle aspiration biopsy obtained insufficient material for diagnosis, and because pulmonary metastases were suspected, two of the four tumors were extirpated. Intraoperative frozen section found the nodules to be intrapulmonary lymph nodes. Intrapulmonary lymph nodes should be included in the differential diagnosis of coin lesions in the peripheral lung field.

Biopsy, Needle↗
PubMed2001

Pulmonary function, postoperative pain, and serum cytokine level after lobectomy: a comparison of VATS and conventional procedure.

BACKGROUND: Although lobectomy by the video-assisted thoracic surgical (VATS) approach is assumed to be less invasive than lobectomy by the standard posterolateral thoracotomy (PLT) approach, it has not been scientifically proven. METHODS: Twenty-two consecutive, nonrandomized patients, underwent either a VATS approach (n = 13) or a posterolateral thoracotomy approach (n = 9) to perform pulmonary lobectomy for peripheral lung cancers in clinical stage I. Pain and serum cytokines were measured until postoperative day (POD) 14. Pulmonary function tests were performed on POD 7 and POD 14. RESULTS: Postoperative pain was significantly less in the VATS group on PODs 0, 1, 7, and 14. Recovery of pulmonary function was statistically better in the VATS group. Negative correlations between the recovery rates of pulmonary function and postoperative pain were observed on POD 7. The serum interleukin-6 level in the PLT group was significantly elevated on POD 0 compared with the VATS group (posterolateral thoracotomy: 21.6+/-24.3 pg/mL; VATS: 4.1+/-7.9 pg/mL, p = 0.03). CONCLUSIONS: Lobectomy by the VATS approach generates less pain and cytokine production, and preserves better pulmonary function in the early postoperative phase.

Adult↗
PubMed2001

Decrease in level of APG-2, a member of the heat shock protein 110 family, in murine brain following systemic administration of kainic acid.

APG-2 belongs to the heat shock protein 110 family. Although kainic acid (KA)-induced seizures are known to elicit expression of inducible heat shock protein 70 (HSP70) in the brain, no investigation has been carried out on the APG-2 level after excitatory amino acid-induced seizures. By means of an immunoblot assay, we determined the levels of HSP70 and APG-2 in discrete brain structures of mice after a single intraperitoneal injection of KA or N-methyl-D-aspartic acid (NMDA). APG-2 level was significantly decreased in frontal cortex, hippocampus, and striatum three days after the administration of KA, while HSP70 level was increased in these regions following the administration. In any of these regions, APG-2 levels were returned to the control levels 10 days after the administration. However, no significant changes were observed in levels of both HSP70 and APG-2 in hypothalamus, midbrain, medulla-pons, and cerebellum of the mice. By contrast, NMDA administration did not significantly affect both levels in any of the regions examined. These findings indicate that the transient decrease in APG-2 expression is one of the intracellular events elicited by signals peculiar to KA, but not by those peculiar to NMDA, in telencephalon of murine brain.

Animals↗
PubMed2001

Amplification of 3q26 approximately qter correlates with tumor progression in head and neck squamous cell carcinomas.

Biological characteristics of malignant tumors including head and neck squamous cell carcinoma (HNSCC) are greatly affected by genetic alterations. However, the relationship between chromosomal aberrations and pathologic tumor stage in HNSCC has not been elucidated. In 32 patients, DNA sequence copy number aberrations (DSCNA) were surveyed by comparative genomic hybridization (CGH) combined with a microdissection method. The average number of DSCNA was 15.3 per tumor and increased with tumor stage (P<.05). DNA copy number gain was detected at 3q26 approximately qter in 29 tumors (91%), and 13 of these tumors displayed marked DNA amplification. Tumor stage was linked with this amplification (P<.05). The increase in DSCNA and amplification of 3q26 approximately qter are likely to be useful markers for estimating tumor progression in HNSCC.

Adult↗
PubMed2001

Overall survival and local recurrence of 406 completely resected stage IIIa-N2 non-small cell lung cancer patients: questionnaire survey of the Japan Clinical Oncology Group to plan for clinical trials.

BACKGROUND: the group of completely resected stage IIIA-N2 non-small cell lung cancer patients (NSCLC) is considered to be heterogeneous in various aspects including survival and the recurrent pattern. In the present study, we attempted to clarify the factors which separate these patients into high and low risk groups based on the survival and local recurrence. METHODS: a questionnaire survey on the survival and local recurrence of non-small cell lung cancer patients with pathological stage IIIA-N2 disease who underwent a complete resection from January 1992 to December 1993 was performed by the Japan Clinical Oncology Group as of July 1999. The information on the survival of 406 patients and that of local recurrence in 332 of them was available. RESULTS: the 5-year survival of the 406 patients was 31.0%. In a univariate analysis, the age, clinical and pathological T status, number of N2 stations, pathological N1 disease, operative modality and postoperative radiotherapy were all found to be important prognostic factors. Clinical N2 disease marginally influenced the survival (P=0.07). In a multivariate analysis of these variables including clinical N2 disease, the survival was significantly worse in the case of multiple N2 stations (hazard ratio=1.741), the presence of pathological N1 disease (1.403), pathological T2 or 3 disease (1.399) and an age older than 65 (1.327). The rate of freedom from any local recurrence at the bronchial stump, or in the hilar, mediastinal or supraclavicular lymph nodes at 5 years was 64%. In a univariate analysis of the freedom from local recurrence, the clinical N status, pathological T status, pathological N1 disease and number of N2 stations were all found to be important prognostic factors. A multivariate analysis revealed the freedom from local recurrence to be adversely influenced by multiple N2 stations (hazard ratio=2.05), and the presence of either clinical N1 or 2 (1.733) disease. The 5-year survival and the rate of freedom from local recurrence at 5 years were 43 and 75% in patients with a single N2 station and 17 and 48% in those with multiple N2 stations, respectively. CONCLUSIONS: the number of N2 stations (single vs. multiple N2 stations) was found to be a useful prognostic factor, which can separate completely resected stage IIIA-N2 patients into high and low risk groups regarding both the overall survival and local recurrence.

Adult↗
PubMed2001

Nucleotide sequence of BamHI family satellite DNA and its unit length polymorphism in bluegill sunfish Lepomis macrochirus.

We have isolated and sequenced a member of tandem repetitive DNA containing BamHI site (BamHI family satellite DNA) from bluegill sunfish Lepomis macrochirus. PCR amplification with specific primers was performed to define the size of unit length repeat of the BamHI family satellite DNA, revealing that there were two distinct size of DNA fragments (0.9 kb and 1.3 kb) in the PCR products. The longer fragment (1.3 kb) consisted of internal sub-duplication of shorter fragment (0.9 kb). We have compared the size of PCR products among four fish populations, and found that both fragments co-existed in one population whereas the longer fragment was dominant in other three populations. The results may reflect ongoing homogenization of satellite DNA type over a short evolutionary time scale.

Animals↗
PubMed2001

Insertion of beta-satellite repeats identifies a transmembrane protease causing both congenital and childhood onset autosomal recessive deafness.

Approximately 50% of childhood deafness is caused by mutations in specific genes. Autosomal recessive loci account for approximately 80% of nonsyndromic genetic deafness. Here we report the identification of a new transmembrane serine protease (TMPRSS3; also known as ECHOS1) expressed in many tissues, including fetal cochlea, which is mutated in the families used to describe both the DFNB10 and DFNB8 loci. An 8-bp deletion and insertion of 18 monomeric (approximately 68-bp) beta-satellite repeat units, normally present in tandem arrays of up to several hundred kilobases on the short arms of acrocentric chromosomes, causes congenital deafness (DFNB10). A mutation in a splice-acceptor site, resulting in a 4-bp insertion in the mRNA and a frameshift, was detected in childhood onset deafness (DFNB8). This is the first description of beta-satellite insertion into an active gene resulting in a pathogenic state, and the first description of a protease involved in hearing loss.

Adult↗
PubMed2001

A rapid monitoring system of human herpesviruses reactivation by LightCycler in stem cell transplantation.

To establish a practical monitoring system of human herpesviruses reactivation in patients undergoing stem cell transplantation, we developed a new, very rapid, highly sensitive, and quantitative PCR assay for accurate measurement of human cytomegalovirus (CMV), human herpesvirus 6 (HHV-6) and Epstein-Barr virus (EBV) DNA using LightCycler. The LightCycler system revealed that there was a linear correlation in the wide range of viral template DNA at the indicated number of PCR cycles. Peripheral blood cells were collected from 16 patients undergoing stem cell transplantation. The cut-off level of CMV and HHV-6 was assessed as 10(2) copies/microg and that of EBV as 10(3). High numbers of CMV genomes were detected in 3/13 patients after transplant, and reactivation of HHV-6 was frequently seen, whereas none of the patient showed an elevation of EBV genome copies until the end of the observation period. In the present study, the reactivation of beta herpesviruses is associated with the occurrence of thrombotic microangiopathy (TMA) in two patients undergoing allogeneic BMT. Therefore, it may contribute in clarifying the pathological potential of human herpesviruses using a large number of clinical samples. Our results suggest that this system may be useful for monitoring viral reactivation.

Adolescent↗
PubMed2001

Construction and characterization of BAC libraries for three fish species; rainbow trout, carp and tilapia.

Bacterial artificial chromosome (BAC) libraries are important tools for genomic research. We have constructed seven genomic BAC libraries from three fish species, rainbow trout (Oncorhynchus mykiss), carp (Cyprinus carpio) and tilapia (Oreochromis niloticus). The two rainbow trout BAC libraries have average insert sizes of 58 and 110 kb. The average size of inserts in the carp BAC library is 160 kb. The average insert sizes of the four tilapia BAC libraries are 65, 105, 145 and 194 kb, respectively. These libraries represent good coverage of each genome (2-64 x coverage). The libraries can be screened by conventional colony hybridization and provide a starting point for the construction of high-density filtres or polymerase chain reaction (PCR) screening approaches. These BAC libraries will facilitate the positional cloning of quantitative trait loci (QTLs) for a variety of economically important traits in these species.

Animals↗
PubMed2001

Non-optical tip-sample distance control method for scanning near-field optical microscopy using a piezoresistive micro cantilever.

A piezoresistive micro cantilever is applied to monitor the displacement of an optical fibre probe and to control tip-sample distance. The piezoresistive cantilever was originally made for a self-sensitive atomic force microscopy (AFM) probe and has dimensions of 400 microm length, 50 microm width and 5 microm thickness with a resistive strain sensor at the bottom of the cantilever. We attach the piezoresistive cantilever tip to the upper side of a vibrating bent optical fibre probe and monitor the resistance change amplitude of the strain sensor caused by the optical fibre displacement. By using this resistance change to control the tip-sample distance, the two-cantilever system successfully provides topographic and near-field optical images of standard samples in a scanning near-field optical microscopy (SNOM)/AFM system. A resonant characteristic of the two-cantilever system is also simulated using a mechanical model, and the results of simulation correspond to the experimental results of resonance characteristics.

Journal Article↗
PubMed2001

Carboxyl group of residue Asp647 as possible proton donor in catalytic reaction of alpha-glucosidase from Schizosaccharomyces pombe.

cDNA encoding Schizosaccharomyces pombe alpha-glucosidase was cloned from a library constructed from mRNA of the fission yeast, and expressed in Saccharomyces cerevisiae. The cDNA, 4176 bp in length, included a single ORF composed of 2910 bp encoding a polypeptide of 969 amino-acid residues with M(r) 106 138. The deduced amino-acid sequence showed a high homology to those of alpha-glucosidases from molds, plants and mammals. Therefore, the enzyme was categorized into the alpha-glucosidase family II. By site-directed mutagenesis, Asp481, Glu484 and Asp647 residues were confirmed to be essential in the catalytic reaction. The carboxyl group (-COOH) of the Asp647 residue was for the first time shown to be the most likely proton donor acting as the acid catalyst in the alpha-glucosidase of family II. Studies with the chemical modifier conduritol B epoxide suggested that the carboxylate group (-COO-) of the Asp481 residue was the catalytic nucleophile, although the role of the Glu484 residue remains obscure.

Amino Acid Sequence↗
PubMed2001

Presence of natural killer-cell clones with variable proliferative capacity in chronic active Epstein-Barr virus infection.

Chronic active Epstein-Barr virus infection (CAEBV) is a syndrome that takes diverse clinical courses and is often associated with lymphoproliferative disorders of T/natural killer (NK)-cell lineage. We describe a patient with CAEBV associated with persistent pharyngeal ulcer, and with subsequent nasal T/NK-cell lymphoma in her neck lymph nodes and nasopharynx. Immunophenotyping of lymphoid cells showed that the lineage of Epstein-Barr virus (EBV)-positive cells in the patient was of NK-cell origin. By means of high-dose recombinant interleukin-2, we established an EBV-positive cell line of NK-cell lineage from her peripheral blood. Southern blot analysis for the number of terminal repeat sequences of EBV detected three NK-cell clones in the patient's lymph node. One of these clones was identical to the established cell line but was not observed in the pharyngeal ulcer, while the other two clones were present in the pharyngeal ulcer. These results suggest that the patient had expansion of the three NK-cell clones, one of which had proliferative capacity in vitro and was involved in the formation of the lymphoma. Moreover, the results suggest that the proliferative capacity of EBV-positive cells can be variable even in a single patient, and this variability may explain the clinical diversity in CAEBV.

Adult↗
PubMed2001

A simple and reliable monitoring system to confirm the preservation of the cavernous nerves.

BACKGROUND: It is important to establish a procedure with which to confirm the preservation of the cavernous nerves during nerve-sparing radical surgery. For this purpose, we examined changes in intracavernous pressure (ICP) following electrical stimulation of the neurovascular bundle (NVB) with respect to the continuity of the cavernous nerves. METHODS: Six cases of radical prostatectomy and eight cases of radical cystoprostatectomy were examined. In all cases, prior to prostate removal, electrical stimulation of the site where the NVB was determined to run was performed and the changes in ICP measured. In eight cases, ICP changes were also measured following prostate removal. RESULTS: Prior to prostate removal, ICP changes could be measured in all 28 sides of 14 cases. These changes were classified into two patterns: stimulation-related increases of convex waveform (t1) were observed in 24 sides (85.7%); and waveforms with reversed type (t2), which was thought to be an incomplete type t1, were observed in four sides (14.3%). There were no ICP changes following non-sparing or incomplete sparing of NVB macroanatomically. Of five sides where the NVB was supposedly completely preserved macroanatomically, ICP changes consisted of type t1 on three sides, t2 on one side and type t2 or no change on a single side. All measurements were obtained within 10 min. Neither electrical stimulation nor measurement of ICP caused any adverse effects. CONCLUSION: Intraoperative stimulation of the NVB while monitoring ICP changes provides a simple and reliable method of accurately evaluating the preservation of the cavernous nerves.

Aged↗
PubMed2001

Parkin is associated with cellular vesicles.

We recently identified a novel gene, parkin, as a pathogenic gene for autosomal recessive juvenile parkinsonism. Parkin encodes a 52-kDa protein with a ubiquitin-like domain and two RING-finger motifs. To provide a insight into the function of parkin, we have examined its intracellular distribution in cultured cells. We found that parkin was localized in the trans-Golgi network and the secretory vesicles in U-373MG or SH-SY5Y cells by immunocytochemical analyses. In the subsequent subcellular fractionation studies of rat brain, we showed that parkin was copurified with the synaptic vesicles (SVs) when we used low ionic conditions throughout the procedure. An immunoelectromicroscopic analysis indicated that parkin was present on the SV membrane. Parkin was readily released from SVs into the soluble phase by increasing ionic strength at neutral pH, but not by a non-ionic detergent. To elucidate its responsible region for membrane association, we transfected with green fluorescent protein-tagged deletion mutants of parkin into COS-1 cells followed by subcellular fractionation. We demonstrated the ability of parkin to bind to the membranes through a broad region except for the ubiquitin-like domain. The significance of SV localization of parkin is discussed.

Animals↗
PubMed2001

Developmental changes in the expression of parkin and UbcR7, a parkin-interacting and ubiquitin-conjugating enzyme, in rat brain.

Parkin is a product of the Park2 gene the mutation of which causes autosomal recessive juvenile parkinsonism (AR-JP) characterized by selective dopaminergic neuronal death and absence of Lewy bodies. Recently we found that parkin is directly linked to the ubiquitin (Ub)-proteasome pathway as a Ub-protein ligase (E3) collaborating with a Ub-conjugating enzyme (E2) UbcH7. Here we analysed by in situ hybridization the expression of mRNAs for parkin and UbcR7 (rat orthologue of human UbcH7) in the developing rat brain. Parkin mRNA increased in parallel with neuronal maturation, but was unevenly distributed in various brain regions after four postnatal days. The expression pattern of the UbcR7 mRNA was almost identical to that of the parkin mRNA in all cases examined. Both parkin and UbcR7 mRNAs were distributed in neurones but not glial cells. Our findings indicate that parkin is expressed not only in the substantia nigra, but also uniformly in various brain regions in a development-dependent manner. Co-expression of UbcR7 with parkin suggests that UbcR7 may interact with parkin in vivo for ubiquitination of yet unidentified target protein(s).

Animals↗
PubMed2001

Calcium supplement increase on the second day of sequential two day leukapheresis.

Peripheral blood progenitor cells are collected effectively by leukapheresis of a large volume of peripheral blood. However, protection must be taken for patients or donors from hypocalcemia due to continuous infusion of citric acid. We found a tendency for hypocalcemic symptoms in patients or donors to occur more often on the second day than the first day of the sequential 2 days of leukapheresis. The doses of calcium gluconate supplement and the acid citrate dextrose-A solution administration significantly increased on the second day compared to that of the first day. The blood levels of c-terminal parathormone (PTH), phosphorus, and alkaline phosphatase did not show remarkably abnormal change. However, urine calcium excretion just after leukapheresis was higher than in the period before or after leukapheresis compared to the phosphorus or creatinine excretion. These findings indicate that the cause of a higher tendency to hypocalcemic symptoms on the second day of the sequential 2 days of leukapheresis is due to the higher metabolism of calcium being excreted in the urine during leukapheresis.

Adult↗
PubMed2001

Completely resected stage IIIA non-small cell lung cancer: the significance of primary tumor location and N2 station.

BACKGROUND: The number of N2 stations (single vs multiple N2 stations) is an important prognostic factor in patients with completely resected stage IIIA-N2 non-small cell lung cancer. However, the significance of both the N2 station(s) actually involved and the primary tumor location remains unclear. METHODS: The database was built with the use of a questionnaire survey on the survival of patients with pathologic stage IIIA-N2 non-small cell lung cancer completely resected between January 1992 and December 1993. The survey was performed by the Japan Clinical Oncology Group as of July 1999. The data include information on the survival and N2 stations of 402 patients. RESULTS: A frequently metastasized single N2 station was the lower pretracheal station in primary tumors in the right upper lobe, the subaortic station in the left upper lobe, and the subcarinal station in the right middle or lower lobe and the left lower lobe. In multiple N2 stations, the frequency of metastasis of the N2 station observed in a single N2 station was as high as 72% to 89%, and one or two other frequently metastasized stations were added to each group. Regarding the survival of patients with a primary tumor in each lobe except for the left lower lobe, a single N2 station resulted in a significantly better survival than did multiple N2 stations. Furthermore, the overall survivals classified according to each primary site showed a significant difference among the four primary sites (P =.04). CONCLUSIONS: The primary tumors in each lobe showed a prevalence of N2 station(s). The number of N2 stations is a good prognosticator except in patients with a primary tumor in the left lower lobe. In addition, the site of a primary tumor itself is also considered to influence the survival of the patients.

Adult↗