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Biomedical subjects

S Miyazaki

Publications and source records attributed to S Miyazaki.

At least 217 records · Page 12Linked to original sources
PubMed1998

Mass screening for neuroblastoma at 6 months of age: difficult to justify.

BACKGROUND/PURPOSE: A statistical analysis of the mass screening for neuroblastoma in Japan based on a population study rarely has been reported. This study aims to evaluate retrospectively the effectiveness of mass screening at 6 months of age using the available population data. METHODS: The data on the neuroblastoma cases registered by the Committee for Pediatric Solid Malignant Tumors in the Kyushu area were analyzed based on both screened and unscreened populations in the Kyushu area. RESULTS: From 1988 to 1992, the cumulative incidence of neuroblastoma in children less than 5 years of age was 82 in 484,599 for screened children, and 11 in 92,966 for unscreened children, respectively. Fourteen of the 82 screened patients had negative findings at 6 months of age (MS-negative cases). No significant difference was observed in the cumulative mortality rates from neuroblastoma in children younger than 5 years of age between the screened children and the unscreened children. Six of seven patients who died among the screened children were MS-negative cases with stage III or IV disease. In addition, no significant difference was found in the cumulative mortality rates from the neuroblastoma cases in patients less than 5 years of age between the children screened from 1988 to 1992 (7 of 484,599) and all children from 1980 to 1984 (14 of 668,084). CONCLUSIONS: These findings suggests that the majority of the patients detected by mass screening had a favorable prognosis, and, mass screening in Japan for children less than 6 months of age was not observed to reduce the incidence and mortality from neuroblastoma. Therefore, mass screening at 6 months of age was not found to improve substantially the prognosis of patients with unfavorable neuroblastoma identified over 1 year of age, which is the primary purpose of such mass screening for neuroblastoma.

Evaluation Studies as Topic↗
PubMed1998

Establishment of monolayer culture of pig pancreatic endocrine cells by use of nicotinamide.

A method for the isolation and primary monolayer culture of adult pig pancreatic endocrine (PE) cells was established. Cells were dissociated from the pancreas by autodigestion without addition of proteolytic enzymes and separated into distinct bands in a single centrifugation step using Histopaque-1077 (a mixture of polysucrose and sodium diatrizoate). The cells collected from an interfacial fraction were suspended in RPMI 1640 containing 11 mmol/l D-glucose with or without nicotinamide (0, 10, 20, 40 mmol/l), and then placed in culture dishes. Pancreatic cells formed a monolayer while fibroblasts became detached from the bottom of the dish when cultured in the presence of nicotinamide. More than 80% of monolayer-forming cells were stained for insulin, using an enzymatic method, and were identified as B-cells. Morphologically, the PE cells extended multiple processes terminating in growth-cone-like structures, as visualized by both light microscopy and scanning electron microscopy. Insulin secretion in response to glucose stimulation occurred for 35 days of incubation in the RPMI 1640 medium, with or without nicotinamide. Exposure of the cells to nicotinamide for 35 days resulted in a 2-3-fold increase in insulin secretion in response to high glucose stimulus (16.7 mmol/l) compared with low glucose (5.5 mmol/l). Glucose-induced Ca2+ responses were examined in individual cells cultured for 35 days in the presence of 10 mmol/l nicotinamide, using Ca2+ imaging with fura-2. These results indicate that it is possible to prepare pig PE cells in monolayer culture with low fibroblast contamination and to maintain functioning B-cells in vitro for relatively long periods. The present method provides useful preparations for further morphological and physiological studies on the differentiation, growth and regenerative capacity of islet cells.

Animals↗
PubMed1998

Inhibition of leukotriene synthesis by terfenadine in vitro.

To determine the inhibitory mechanisms of terfenadine on the synthesis of leukotriene C4 (LTC4), an important mediator in allergic diseases, we evaluated the action of terfenadine on the IgE-dependent production of LTC4 in rat basophilic leukaemia 2H3 cells. Rat IgE-loaded cells were stimulated with anti-IgE in the presence or absence of various concentrations of terfenadine and the level of LTC4 released into the medium was measured by performing a specific radio immunoassay. Terfenadine inhibited the synthesis of LTC4 to 67.2% at a concentration of 5 microg/ml. LT synthesis was directly suppressed by inhibition of 5-lipoxygenase (5-LO) through calcium ion-independent mechanisms, and was also possibly suppressed by inhibition of cytosolic phospholipase A2 and 5-LO by blocking the influx of intracellular calcium ion that was initiated by IgE-related stimulation.

Animals↗
PubMed1998

Effect of dexamethasone on leukotriene synthesis in DMSO-stimulated HL-60 cells.

Human leukemia (HL) 60 cells were differentiated by dimethylsulfoxide (DMSO) treatment to granulocyte-like cells, leukotriene (LT) synthesizing activity of which was increased in response to the differentiation of the cells. Four synthesizing enzymes, cytosolic phospholipase A2 (cPLA2), 5-lipoxygenase (5-LO), LTA4 hydrolase and LTC4 synthase, and an enzyme associated protein, 5-lipoxygenase activating protein (FLAP) are involved in the generation of LTC4 and LTB4. We examined the expression of messenger RNA (mRNA) for these LT synthesizing enzymes and an associated protein in DMSO differentiated HL-60 cells by reverse transcriptase polymerase chain reaction (RT-PCR). The production of LTC4 and LTB4, measured by radioimmunoassay (RIA), was increased after the incubation with DMSO for more than 3 days. Messenger RNA abundance for 5-LO, LTC4 synthase and LTA4 hydrolase was increased, that for FLAP was stable, but that for cPLA2 was decreased. These results indicate that DMSO induced increase of LT synthesis is associated with the increase of mRNA expression of 5-LO, LTC4 synthase and LTA4 hydrolase, although the precise regulatory mechanisms of the increased mRNA expression are not determined. We also investigated an action of dexamethasone (DEX) on DMSO-induced enhancement of LT synthesis. DEX suppressed DMSO induced increase of LTC4 synthesis, but rather enhanced DMSO induced LTB4 production. The DEX attenuated the DMSO-induced increase of mRNA expression for LTC4 synthase, but showed no effect on that for LTA4 hydrolase. The inhibition of LTC4 synthesis is associated with the suppression of mRNA expression for LTC4 synthase. However, increased LTB4 synthesis by DEX is regulated by the mechanisms which are independent from mRNA level of LTA4 hydrolase.

5-Lipoxygenase-Activating Proteins↗
PubMed1998

Detection of mitochondrial DNA nucleotide 11778 point mutation of Leber hereditary optic neuropathy from archival stained histopathological preparations.

PURPOSE: We evaluated the availability of archival histopathological preparations for genetic diagnosis of Leber hereditary optic neuropathy (LHON). METHODS: Preparations of various tissues of an autopsied case of LHON, and of the optochiasmal arachnoidea of nine cases of bilateral optic neuropathy (BON) were studied to determine the presence of a point mutation of the mitochondrial DNA nucleotide (nt) 11778 using PCR method. RESULTS: An nt11778 point mutation was detected in all preparations of the autopsied case. Five preparations out of six BON cases who were diagnosed as LHON based on positive family history, revealed this point mutation. This mutation was also detected in two of three BON patients with no family history of the disease. CONCLUSION: The archival preparations were found to be available as materials of genetic diagnosis for LHON, which indicated that it would be capable to reevaluate retrospectively the pedigree of LHON and BON cases.

Adolescent↗
PubMed1998

Donor leukocyte infusion after allogeneic bone marrow transplantation was not effective for relapsed rhabdomyosarcoma.

A 10-year-old boy with metastatic rhabdomyosarcoma had an HLA-identical sibling and received an allogeneic BMT. Recurrence was detected in the BM as the only site of treatment failure 12 months after BMT. Donor leukocyte infusion (DLI) was chosen as salvage therapy. Although sufficient cells (a total of 29.7 x 10(7)/kg) were infused, no signs of acute GVHD nor BM aplasia occurred and the patient died of disease progression 9 months after DLI.

Bone Marrow Transplantation↗
PubMed1998

High frequency of fusion transcripts of exon 11 and exon 4/5 in AF-4 gene is observed in cord blood, as well as leukemic cells from infant leukemia patients with t(4;11)(q21;q23).

The MLL gene located on chromosome 11q23 and its translocation to the AF-4 gene located on chromosome 4q21 play a pivotal role in leukemogenesis in infancy. Studies of identical leukemic twins have provided evidence of the MLL rearrangement as a fetal event during pregnancy. We analyzed the presence and frequency of the MLL/AF-4 rearrangement in normal cord blood. Although no chimeric mRNA of MLL or AF-4 was detected in 65 cord blood samples, in-frame fusion transcripts of exon 11 and exon 4 or 5 of the AF-4 gene were detected in three of the samples by a nested polymerase chain reaction. When primers of exon 11 and exon 5 of the AF-4 gene were used, two forms of fusion transcripts (AF-4 exon 11/4 or exon 11/5) were detected in 20 of the 65 cord blood samples (31%) and also four of six leukemic cell samples with t(4;11) (67%), whereas such transcripts were not observed in any of 21 peripheral blood samples nor in fetal fibroblasts. These findings suggest that the in-frame fusion of exon 11 and exon 4 or 5 of the AF-4 gene frequently occurs in hematopoietic cells during the intrauterine period, even in a healthy fetus. Although it is unknown whether the proteins of the AF-4 fusion transcripts have some functions, the instability of the AF-4 gene may be associated with the leukemogenesis of infant leukemia.

Chromosomes, Human, Pair 11↗
PubMed1998

Intradural extra-arachnoid schwannoma of the upper cervical spine.

A very rare case of intradural extra-arachnoid schwannoma involving the upper cervical spine is described. The tumour most likely originated from the extra-subarachnoid angle region, with its unusual pattern of expansion within the spinal canal resulting from such characteristics of the upper cervical region as a relatively wide spinal canal, an extensive ventral subarachnoid space, and membranous ventromedian and lateral anchoring structures which influenced the direction of tumour enlargement.

Cervical Vertebrae↗
PubMed1998

Effect of unilateral section of cervical afferent nerve upon optokinetic response and vestibular nystagmus induced by sinusoidal rotation in guinea pigs.

An experiment was carried out in guinea pigs to clarify the effect of unilateral section of cervical afferent nerve (C1-C3) upon optokinetic nystagmus and vestibular nystagmus induced by sinusoidal rotation. To produce optokinetic nystagmus and optokinetic after-nystagmus, a random dot pattern was utilized as visual stimulation at a speed of 30 degrees/s. As for vestibular nystagmus, sinusoidal rotation at a frequency of 0.1 Hz with an amplitude of 120 degrees was used. Results showed that for about a week after the surgical section of the C1-C3 nerves, directional preponderance of the vestibular nystagmus was found toward the lesion side, whereas no significant change was obtained in optokinetic nystagmus and optokinetic after nystagmus. This asymmetric change of the vestibular nystagmus was compensated for within a week or two. Thus. unilateral section of the cervical afferent nerve produced only a temporary effect on the vestibulo-ocular reflex but it had no significant effect on the optokinetic response.

Afferent Pathways↗
PubMed1998

Influence of nasal obstruction on obstructive sleep apnea.

Nasal obstruction, either partial or complete, may cause snoring and/or obstructive sleep apnea (OSA). However, there is no clear answer to the question, in how many cases nasal airway is a main or combined site of obstruction. Fifty-four OSA cases (47 men and 7 women) were examined by measuring the upper airway pressure gradient while they were asleep, using a multi-sensor pressure transducer. Their average apnea + hypopnea index was 35.6/h and body mass index was 26.5 kg/m2. Our hypothesis was that elevation of the inspiratory negative airway pressure at the epipharynx could indicate the influence of nasal obstruction. Seven cases out of 54 proved to have inspiratory negative pressure more than -3 cmH2O at the epipharynx during sleep. Four cases indicated elevated negative pressure in the lateral position, and 3 cases out of 19 CPAP candidates showed the same elevation in the supine position. In all 7 cases, the main obstructive site was either at the soft palate or the base of the tongue. Although nasal airway is the preferred route of respiration during sleep, nasal obstruction itself cannot be a main factor causing OSA, but a co-factor of OSA during sleep.

Adult↗
PubMed1998

Evaluation of uvulopalatopharyngoplasty in treatment of obstructive sleep apnea syndrome.

Many methods have been reported to select the proper candidates for uvulopalatopharyngoplasty (UPPP) among obstructive sleep apnea patients. Polysomnography with intraluminal pressure recordings in the upper airway was found useful to predict obstructive site(s) and hence the success of surgery. According to the pressure analysis, 11 cases with high negative pressure at the mesopharynx were selected for UPPP, while UPPP combined with midline partial glossectomy (UPPP-MLG) was done in 18 cases proved to have high negative pressure difference between the mesopharynx and esophagus. A reduction of the apnea hypopnea index (AHI) of more than 50% after UPPP was found in 8 cases (72.7%) and in 11 cases (61.l%) after UPPP-MLG. It was found that the response rate was lower among the second group if compared to that of the first because of other aggravating factors rather than simple obstruction at the level of the soft palate and or tonsils-tongue base level.

Adult↗
PubMed1998

Formal design and implementation of an improved DDBJ DNA database with a new schema and object-oriented library.

MOTIVATION: The DNA Data Bank of Japan (DDBJ) has developed a new DNA database system with a new schema design to accommodate rapid change and growth of requirements on the system. RESULTS: The new schema and systems were created using an object-oriented design approach. The design was accomplished in accordance with ANSI/SPARC three-level schema architecture. First, the conceptual schema was designed using a functional model named AIS (associative information structure) and was visualized in extended diagram format. The model is a natural extension of an ER (entity relationship) model and describes real-world objects in binary associations between entities with the concept of order. Second, the schema was mapped on a relational database as a physical schema. All details are concentrated in this schema and the layer lying above enjoys physical independence. Finally, as another layer, external modeling was introduced for the database applications interface. It provides set-at-a-time basis operations and was implemented as a C++ object-oriented library. On this common framework of a new schema, a new annotator's workbench named Yamato II and a World Wide Web (WWW) submission system named Sakura have been successfully developed to improve drastically daily transactions in the DDBJ. AVAILABILITY: Sakura is available at the following address: http://sakura.ddbj.nig.ac.jp. CONTACT: hsugawar@genes.nig.ac.jp

Base Sequence↗
PubMed1998

Antibacterial activity of AM-1155 against penicillin-resistant Streptococcus pneumoniae.

AM-1155, a novel fluoroquinolone, exhibited potent activity against Streptococcus pneumoniae, including penicillin-resistant strains; the MIC90 for 48 clinical isolates was 0.25 mg/L. The antibacterial activity of AM-1155 against S. pneumoniae was higher than that of levofloxacin (MIC90 1 mg/L) and comparable with that of sparfloxacin. The MIC90s of penicillin G and erythromycin were 2 and > 4 mg/L, respectively. AM-1155 showed no cross-resistance to penicillin or erythromycin. For experimental murine pneumonia with S. pneumoniae intermediately resistant to penicillin, oral administration of AM-1155 showed efficacy higher than that of levofloxacin and equal to that of sparfloxacin. The efficacy of AM-1155 was also equal to that of subcutaneous penicillin G administration at the same dosage.

Animals↗
PubMed1998

Increased expression of cyclooxygenase-2 to -1 in human colorectal cancers and adenomas, but not in hyperplastic polyps.

BACKGROUND: Non-steroidal anti-inflammatory drugs can reduce the risk of colorectal cancer. Reportedly, mRNA expression of cyclooxygenase-2 (COX-2) is elevated in human colorectal cancers compared with accompanying normal mucosa. The present study was undertaken to establish a simple analytical procedure to quantify COX-2 expression levels and to characterize COX-2 expression levels in human colorectal cancers, adenomas and hyperplastic polyps. METHODS: The combination of PCR using common primers designed in the highly conserved regions and fluorescence-based single-strand conformation polymorphism (F-SSCP) analysis of the products is used for quantitative determination of the proportions of COX-2 mRNA in human colorectal cancers, adenomas, hyperplastic polyps and accompanying normal mucosa. RESULTS: The present F-SSCP analysis was a simple and powerful method for quantitative determination of the proportions of COX-2 mRNA. The proportion of COX-2 mRNA was higher in cancer tissues than in accompanying normal mucosa in 46 of the 50 cancers. There was no significant correlation between the increase of the COX-2 proportion and tumor location or stages. The enhanced COX-2 expression was also observed in colorectal adenomas. On the other hand, the proportion of COX-2 mRNA in hyperplastic polyps was not significantly different from that in normal mucosa. CONCLUSIONS: The proportion of COX-2 to COX-1 expression was elevated in most human colorectal cancers and adenomas, but not in hyperplastic polyps. Therefore, the increased proportion of COX-2 expression might be an early event in the carcinogenesis of colorectal cancer.

Adenoma↗
PubMed1998

Adenophostin, a potent agonist of the inositol 1,4,5-trisphosphate receptor, is useful for fertilization of mouse oocytes injected with round spermatids leading to normal offspring.

Precursor male gametes such as round spermatids and secondary spermatocytes are known to possess the potential to achieve fertilization and embryonic development when injected into mature oocytes, but in previous studies, injected mouse spermatids did not activate the oocytes. In this study, we confirmed that this was the case because spermatids by themselves could not induce an increase in intracellular Ca2+ concentration ([Ca2+]i) of oocytes, the pivotal signal in oocyte activation. Repetitive rises in [Ca2+]i (Ca2+ oscillations), lasting for at least 3 h as observed at fertilization, were produced by a single injection of adenophostin B isolated from fungal products, a novel nonmetabolizable agonist of the inositol 1,4,5-trisphosphate receptor (InsP3r), which mediates Ca2+ release from the endoplasmic reticulum. Ca2+ oscillations were blocked by an antibody against the type 1 InsP3r. About 95% of oocytes were activated by adenophostin (0.3-0.4 microM in the oocyte). Simultaneous injection of a round spermatid and adenophostin resulted in 55% fertilization success in association with male and female pronucleus formation and development to two-cell embryos. Furthermore, 25% of two-cell embryos that were transplanted to foster mothers developed to normal offspring. All infants grew into adults that reproduced healthy second generations. Adenophostin will be useful for parthenogenetic oocyte activation in the biotechnology of animal reproduction. Injection combined with precursor spermatozoa may be applicable to assisted conception therapy for patients with defective spermatogenesis.

Adenosine↗
PubMed1998

Disseminated cryptococcosis associated with adrenal masses and insufficiency.

A case of primary adrenal insufficiency with bilateral adrenal masses and meningitis due to disseminated cryptococcosis in a patient with mild non-insulin-dependent diabetes is presented. The diagnosis was made by fine-needle aspiration biopsy cytology. Although the meningitis responded to antifungal therapy, the bilateral adrenal gland enlargement did not change. Reflecting this, cryptococcal antigen titers became negative in CSF, but fell to 1:8 in serum. Although antifungal therapy continued, cryptococcal antigen titer increased both in CSF and serum for 50 days. Because the adrenal glands were the apparent focus for the persistent fungemia, bilateral adrenalectomy was performed. Antifungal therapy for an additional 15 months was needed to achieve negative serum cryptococcal antigen titers. Although adrenal insufficiency due to disseminated cryptococcosis is rare in healthy hosts, it should be included in differential diagnosis of unilateral and bilateral adrenal masses.

Adrenal Glands↗
PubMed1998

Posteroinferior acromioclavicular dislocation with supraspinatus tear. A case report.

A 20-year-old man was treated for posteroinferior acromioclavicular dislocation. The diagnosis was based on standard radiographs and intraoperative findings. The distal end of the clavicle had impaled the supraspinatus muscle. Open reduction was performed 2 weeks after injury, followed by wire fixation of the acromioclavicular joint and repair of the torn superior acromioclavicular ligament and coracoclavicular ligaments. Two years after the procedure, standard radiographs revealed normal anatomic alignment of the acromioclavicular joint, with pain free range of motion. Active elevation in the scapular plane was 180 degrees, active external rotation was 80 degrees in the anatomic position, and passive internal rotation was to the T5 vertebra. The patient returned to playing baseball and tennis and was satisfied with the postoperative result.

Acromioclavicular Joint↗