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H Kobayashi

Publications and source records attributed to H Kobayashi.

At least 37 records · Page 2Linked to original sources
PubMed2006

A ceramic prosthesis for the treatment of tumours of the distal radius.

Despite extensive experience with prosthetic replacement for the reconstruction of limbs following juxta-articular resection of tumours, there are few reports of prosthetic replacement of the distal radius. We present two cases of massive bone defects of the distal radius in which alumina ceramic prosthetic replacements were used. We evaluated the patients more than ten years after the procedure. Both patients had degenerative changes to the wrist. This, however, was not associated with pain or decreased function, and both had returned to their previous occupation after surgery. When a patient has a massive defect of the distal radius, reconstruction using a ceramic prosthesis is a reasonable alternative to using autograft. This method of treatment results in little pain, a moderate range of movement and satisfactory function.

Aluminum Oxide↗
PubMed2006

Antiangiogenic and radiotherapy for cancer treatment.

Tumor growth and progression depends on tumor angiogenesis, the growth of tumor blood vessels, therefore, targeting tumor angiogenesis is a very promising approach for controlling tumor growth and/or causing regression. Tumor blood vessels have been recognized as a critical component of radiation response to the point of being independent of tumor oxygenation during radiation. An anti-angiogenic approach has been considered less likely to develop drug resistance. But recent findings suggest that anti-angiogenesis causes hypoxia that selects tumor cells (due to genetic instability) that are less dependent on blood supply and leads to drug resistance. The approach of combination of anti-angiogenesis with ionizing radiation by targeting both endothelial and tumor cells should minimize this possibility. The combination may produce a synergistic anti-tumor effect.

Angiogenesis Inhibitors↗
PubMed2005

Photocatalytic activity of the RuO2-dispersed composite p-block metal oxide LiInGeO4 with d10-d10 configuration for water decomposition.

The ruthenium oxide-loaded composite p-block metal oxide LiInGeO4 with d10-d10 configuration exhibited high photocatalytic activity for the overall splitting of water to produce H2 and O2 under UV irradiation. Changes in the photocatalytic activity with the calcination temperature of LiInGeO4, the amount of RuO2 loaded, and the states of RuO2 indicated that the combination of highly crystallized LiInGeO4 and a high dispersion of RuO2 particles resulted in high photocatalytic activity. Structurally, LiInGeO4 contained heavily distorted InO6 octahedra and GeO4 tetrahedra, generating a dipole moment inside. The high photocatalytic performance of RuO2-loaded LiInGeO4 supports the existing view that the photocatalytic activity correlates with the dipole moment. The DFT calculation showed that the top of the valence band (HOMO) was composed of the O 2p orbital while the bottom of the conduction band (LUMO) was formed by the hybridized In 5s5p + Ge 4s4p + O 2p orbitals. The highly dispersed conduction band, indicative of a high mobility of photoexcited electrons, was responsible for the high photocatalytic performance.

Journal Article↗
PubMed2005

Application of boron-entrapped stealth liposomes to inhibition of growth of tumour cells in the in vivo boron neutron-capture therapy model.

Tumour cell destruction in boron neutron-capture therapy (BNCT) is due to the nuclear reaction between (10)B and thermal neutrons. It is necessary for effective BNCT therapy to accumulate (10)B atoms in the tumour cells. The delivery system consisted of polyethylene-glycol (PEG) binding liposomes (DPPC/cholesterol/DSPC-PEG2000) with an entrapped (10)B-compound and we evaluated the cytotoxic effects of intravenously injected (10)B-PEG-liposomes on human pancreatic carcinoma xenografts in nude mice with thermal neutron irradiation. After thermal neutron irradiation of mice injected with (10)B-PEG-liposomes, growth of AsPC-1 tumours was suppressed relative to controls. Injection of (10)B-PEG-liposomes caused the greatest tumour suppression with thermal neutron irradiation in vivo. These results suggest that intravenous injection of (10)B-PEG-liposomes can increase the retention of (10)B atoms by tumour cells, causing suppression of tumour growth in vivo, after thermal neutron irradiation.

Animals↗
PubMed2005

A long-term follow-up study of radiographically evident degenerative changes in the temporomandibular joint with different conditions of disk displacement.

The purpose of this retrospective study is to assess the relationship between an initial and persisting condition of disk displacement (DD) and the long-term course of radiographically evident degenerative changes of the temporomandibular joint (TMJ). Nineteen patients agreed to a radiographic follow-up examination of 29 joints and were included in this study. The joints were radiographically assessed at the first visit and at least 46 months after the first visit (mean 89.3 months). At the time of the follow-up, all subjects had a good clinical course after a favorable response to the treatments. There were significant relationships between the initial diagnosis of DD and the interval change in the morphology of the articular eminence. The articular eminence became flattened or deformed only in the joints with persistent DD without reduction. And there was a tendency that the condyle became smaller in the joints initially with permanent DD and in the joints which show a progression in the disk-condylar relationship. The results of this study suggested that, in the joints with persisting non-reducing disk displacement, flattening and deformation of the articular eminence and regression of the condylar size were likely to happen even after symptoms and signs of TMJ disorders were resolved or reduced.

Adolescent↗
PubMed2005

Clinical significance of heparin-binding epidermal growth factor-like growth factor in peritoneal fluid of ovarian cancer.

Epidermal growth factor receptor (EGFR) has been implicated in tumour growth and extension of ovarian cancer. Peritoneal fluid in ovarian cancer patients contains various growth factors that can promote tumour growth and extension. In order to investigate the clinical significance of EGFR ligands as activating factors of ovarian cancer, we examined the cell proliferation-promoting activity and the level of EGFR ligands in peritoneal fluid obtained from 99 patients. Proliferation-promoting activity in peritoneal fluid from 63 ovarian cancer patients (OVCA) was much higher than peritoneal fluid from 18 ovarian cyst patients (OVC) and 18 normal ovary patients (NO), and the activity was suppressed only by antibodies against EGFR or heparin-binding epidermal growth factor (HB-EGF). A large difference was observed in the level of EGFR ligands between HB-EGF and TGF-alpha or amphiregulin. The concentration of HB-EGF in OVCA significantly increased compared to that in OVC or NO (P<0.01). No significant difference in the concentration of TGF-alpha and amphiregulin was found between the OVCA and NO or OVC groups. In peritoneal fluid, HB-EGF is sufficiently elevated to activate cancer cells even at an early stage of OVCA. These results suggested that HB-EGF in peritoneal fluid might play a key role in cell survival and in the proliferation of OVCA.

Amphiregulin↗
PubMed2005

Total callosotomy for a case of lissencephaly presenting with West syndrome and generalized seizures.

CASE REPORT: An 11-month-old girl had an onset of oculogyric crisis at 2 months and she presented with epileptic spasms and generalized tonic seizures with series formation at 3 months. Her seizures were medically intractable and her development had gradually regressed after that. MRI showed severe lissencephaly in bilateral hemispheres. Interictal EEG showed hypsarrhythmia periodically and sporadic spike waves in the right hemisphere. The generalized tonic seizures began with bi-frontal polyspikes on EEG. Our diagnosis was lissencephaly presenting with West syndrome and generalized tonic seizures. A total callosotomy was performed at 11 months. OUTCOME: Postoperative frequency of seizures decreased prominently and developmental progression was resumed. CONCLUSIONS: This case showed that the corpus callosum may play an important role in some types of symptomatic West syndrome. Corpus callosotomy for treating symptomatic West syndrome should be considered as an option after careful selection and consideration of the timing of surgery.

Corpus Callosum↗
PubMed2005

A case of gastrointestinal stromal tumour of the ampulla of Vater.

Gastrointestinal stromal tumour rarely develops in the duodenal ampulla region. We report here a case of gastrointestinal stromal tumour of the ampulla of Vater found in a 44-year-old Japanese man presenting with biliary obstruction. He died of hepatic failure with diffuse liver metastasis. The postmortem examination showed a large Borrman type III-like tumour in the duodenal ampullary region with direct invasion of the pancreas and extrahepatic bile duct as well as metastases to the liver and regional lymph nodes. The duct orifice was located at the centre of the tumour. Microscopically, the tumour consisted of anaplastic spindle cells with high mitotic activity (90 mitoses per 50 high-power fields). Immunohistochemically, the spindle cells were positive for KIT and CD34. The final diagnosis was high-grade malignant gastrointestinal stromal tumour of the ampulla of Vater. Considering the recent advances in the diagnosis and treatment of gastrointestinal stromal tumour, this neoplasm should be included in the differential diagnosis of the tumours appearing in the duodenal ampulla region.

Adult↗
PubMed2005

National hospital infection surveillance on methicillin-resistant Staphylococcus aureus.

Surveillance of methicillin-resistant Staphylococcus aureus (MRSA) infections in Japan was performed in 1995 and 1996. Hospital infection rates of MRSA appear to have remained stable in recent years, and this study was undertaken to test this hypothesis. In national surveillance, the incidence of MRSA hospital infections per 100 admissions remained stable at between 0.7 and 0.8 from 1999 to 2003, with a tendency towards a slight decline. This study shows that precautions against MRSA infection in Japan may prove to be an effective preventive measure.

Cross Infection↗
PubMed2005

Significance of chemokine receptor expression in aggressive NK cell leukemia.

Natural killer (NK) cell-type lymphoproliferative diseases of granular lymphocytes can be subdivided into aggressive NK cell leukemia (ANKL) and chronic NK cell lymphocytosis (CNKL). One reason for the poor outcome in ANKL is leukemic infiltration into multiple organs. The mechanisms of cell trafficking associated with the chemokine system have been investigated in NK cells. To clarify the mechanism of systemic migration of leukemic NK cells, we enrolled nine ANKL and six CNKL cases, and analyzed the expression profiles and functions of chemokine receptors by flowcytometry and chemotaxis assay. CXCR1 was detected on NK cells in all groups, and CCR5 was positive in all ANKL cells. Proliferating NK cells were simultaneously positive for CXCR1 and CCR5 in all ANKL patients examined, and NK cells with this phenotype did not expand in CNKL patients or healthy donors. ANKL cells showed enhanced chemotaxis toward the ligands of these receptors. These results indicated that the chemokine system might play an important role in the pathophysiology of ANKL and that chemokine receptor profiling might be a novel tool for discriminating ANKL cells from benign NK cells.

Adult↗
PubMed2005

Relaxant effect of adrenomedullin on bovine isolated iris sphincter muscle under resting conditions.

1. The mechanisms involved in the fine adjustment of iris sphincter muscle tone are largely unknown. The aim of the present study was to clarify the effects of adrenomedullin on the resting tension of the bovine isolated iris sphincter muscle. 2. The motor activity of the bovine isolated iris sphincter muscle was measured isometrically. The effects of adrenomedullin on resting tension were analysed in the presence of indomethacin. The presence of adrenomedullin mRNA in the preparation was determined by reverse transcription-polymerase chain reaction. Immunolabelling for adrenomedullin was also performed. 3. Adrenomedullin significantly decreased the resting tension of the muscle. The relaxant effect of adrenomedullin was significantly inhibited by adrenomedullin (22-52), a putative antagonist for the adrenomedullin receptor, or calcitonin gene-related peptide (CGRP) (8-37), a putative antagonist for the CGRP1 receptor. The relaxant effect was almost completely blocked by a combination of adrenomedullin (22-52) and CGRP (8-37). 4. The relaxant effect of adrenomedullin was also significantly diminished by 2',5'-dideoxyadenosine, an inhibitor of adenylate cyclase, N(G)-nitro-L-arginine, an inhibitor of nitric oxide synthesis, or 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one, an inhibitor of soluble guanylate cyclase. 5. Reverse transcription-polymerase chain reaction analysis showed that adrenomedullin mRNA was expressed in the muscle strip. Immunopositive staining for adrenomedullin was detected in blood vessel cells and in the iris sphincter muscle cells. 6. These results suggest that adrenomedullin may be an autocrine and paracrine regulator of the resting tension of the iris sphincter muscle. Its biological effects may be due to the direct involvement of adrenomedullin receptors and also to the stimulation of CGRP1 receptors. The stimulation of these receptors by the peptide leads to the activation of adenylate cyclase and soluble guanylate cyclase and subsequent relaxation of the muscle strip.

Adrenomedullin↗
PubMed2005

Protein kinase-A-dependent osteoprotegerin production on interleukin-1 stimulation in human gingival fibroblasts is distinct from periodontal ligament fibroblasts.

Periodontitis, a chronic inflammatory disease, is characterized by increased expression of interleukin (IL)-1 and other inflammatory mediators resulting in extensive osteoclast formation and bone loss. Expression of receptor activator of nuclear factor kappa B ligand (RANKL) and its decoy receptor, osteoprotegerin (OPG), by osteoblasts is important to regulate osteoclast differentiation. The aim of the present study was to investigate the regulatory effects of IL-1 on RANKL and OPG production by mesenchymal fibroblasts in periodontal tissue. Human gingival fibroblasts (HGF) and periodontal ligament fibroblasts (PDL) were stimulated with IL-1alpha with or without protein synthesis inhibitor cycloheximide (CHX), protein kinase A (PKA) inhibitors, protein kinase C (PKC) inhibitors and prostaglandin E(2) (PGE(2)) inhibitor. In some experiments, the cultured cells were directly stimulated with either PKA or PKC activators. In HGF, IL-1alpha-stimulated OPG mRNA expression was high and could be reduced by CHX. PKA inhibitor completely abrogated IL-1alpha-induced OPG mRNA expression and OPG production. Endogenous PGE(2) further enhanced IL-1alpha-induced OPG production in HGF. In PDL, RANKL mRNA expression was greatly augmented by IL-1alpha. IL-1alpha induced OPG mRNA expression and protein production. PKC inhibitor partially reduced IL-1alpha-induced OPG production and PKC activator enhanced OPG production in PDL. The IL-1alpha-stimulated OPG mRNA expression in HGF was greater than PDL. These results provide new evidence for the possible osteoclastogenesis-inhibitory function of HGF through PKA activity pathway. PDL utilized PKC for OPG production. Thus, we emphasize that HGF and PDL have different characteristics of host defence mechanism against inflammatory process.

Adult↗
PubMed2005

Clinico-cytological study of uterine papillary serous carcinoma.

OBJECTIVE: The aim of this study was to determine whether or not we could distinguish uterine papillary serous carcinoma (UPSC) from other types of endometrial cancer by cytology. METHODS: We examined the cytological findings of the endometrium from five cases with UPSC and compared them with 10 cases with endometrioid adenocarcinoma, grade 1 (G1). A morphometric analysis was performed. Cytological samples from the cervix and ascites of the patients with UPSC were also reviewed. RESULTS: All five patients had FIGO stage III and IV tumours. Three patients died of the disease and two are still alive with disease. The tumour cells of UPSC tended to be shed in papillary clusters with a tumour diathesis. Psammoma bodies were seen only in UPSC. The frequency of irregular-shaped nuclei, membrane thickness and eccentric nuclei in UPSC was higher than in G1. The chromatin pattern was coarsely granular, and both anisonucleosis and bare nuclei were prominent in UPSC. Cytomorphometrically, the maximum diameter of the nuclei in UPSC was significantly greater than that in G1. The nucleoli were also more often seen in UPSC than in G1. The findings of the nuclei and nucleoli in the cervical and peritoneal fluid cytology closely resembled those in endometrial smears. The features of the cervical smears and peritoneal fluid cytology were different from those of endometrial cytology regarding clear background and small clusters of cells. CONCLUSION: As the endometrial cytology findings accurately suggested the histological diagnosis of UPSC, the diagnosis of UPSC was confirmed in this study by endometrial cytology. The cytological diagnosis of UPSC should be based on the findings of tumour diathesis, psammoma bodies and papillary clusters composed of tumour cells with enlarged nuclei and numerous nucleoli.

Aged↗
PubMed2005

Cytological study of early cervical adenocarcinoma: special reference to the depth of invasion.

OBJECTIVE: Early cervical adenocarcinoma (ECA) with a tumour depth of <3 mm has a good prognosis. To clarify the cytological features of ECAs with depth <3 mm, these were compared with those of ECA with 3-5 mm and invasive adenocarcinoma (IA) invading the cervical wall with more than 5 mm in depth. METHODS: The cervical cytological features of ECAs with depth <3 mm (14 cases) were compared with those of ECA with 3-5 mm (four cases) and IA (13 cases). Cytologically, the presence or absence of tumour diathesis, number of atypical cells, crowded cell groups, groups with glandular structures, feathering, groups with palisading borders, rosettes, clusters, cell shape and size, nuclear shape and size, nucleolar shape and size, chromatin distribution, border and character of cytoplasm, and single cell pattern were evaluated. RESULTS: A tumour diathesis was seen in five of 14 ECA <3 mm in depth (36%), all four ECA with 3-5 mm (100%) and 11 of 13 IA with more than 5 mm (85%). Single cells, macronucleoli and coarsely granular chromatin pattern were less frequent in ECA of <3 mm than that in ECA with 3-5 mm and IA. The number of atypical cells and glandular structures in ECA was significantly less than that in IA. Cell crowding, feathering, palisading and rosettes were common in both ECA and IA. CONCLUSION: The characteristic cytological features of ECA with depth <3 mm, having a good prognosis, were clean background, fewer single cells and macronucleoli, and less frequent coarsely granular chromatin pattern compared with those in ECA with 3-5 mm and IA. The number of atypical cells and glandular structures in ECA was significantly less than that in IA. Familiarity with the cytological features of ECA and its mimics is essential.

Adenocarcinoma↗
PubMed2005

A novel STK11 germline mutation in two siblings with Peutz-Jeghers syndrome complicated by primary gastric cancer.

Patients with Peutz-Jeghers syndrome (PJS) are known to be at risk of gastric cancer (GC), and the STK11 gene is a susceptibility gene for PJS. However, as no cases of PJS with GC in which a STK11 germline mutation has been identified have ever been reported and other susceptibility genes have also been suggested to be involved in PJS, the relation between STK11 germline mutations and GC in PJS is still unknown. In this study, we used sequencing analysis to investigate the STK11, CDH1, and TP53 loci for a germline mutation in two siblings with PJS with primary GC. A novel type of the STK11 germline mutation, c.890delG, encoding a truncated protein (p.Arg297fsX38) was identified, but no germline mutations of the CDH1 and TP53 genes were detected. No inactivation of the wild-type allele by somatic mutation or chromosomal deletion or hypermethylation at the 5'-CpG site of STK11 was detected in the GC. This is the first report of a STK11 germline mutation in a PJS patient with GC and should contribute to establishing correlations between the STK11 germline mutations and GC in PJS patients.

AMP-Activated Protein Kinase Kinases↗
PubMed2005

Carbon dioxide increases acid resistance in Escherichia coli.

AIMS: To investigate how carbon dioxide affects the acid resistance of Escherichia coli. METHODS AND RESULTS: Escherichia coli W3110 was grown in minimal EG medium at pH 7.5, and cells were adapted at pH 5.5 at 37 degrees C with and without supply of carbon dioxide and nitrogen gases. The number of colonies grown on LB medium was measured after cells were challenged in minimal EG medium of pH 2.5 at 37 degrees C under various conditions. When carbon dioxide was supplied at both the acid adaptation and challenge stages, 94% of cells survived after the acid challenge for 1 h, while the survival rates were 50 and 67% when nitrogen gas and glutamate were supplied respectively. After the acid challenge for 3 h, the survival rate observed with the carbon dioxide gas supply was again 2.5-fold higher than those with the nitrogen gas supply. CONCLUSION: Carbon dioxide was shown to participate in the maintenance of high viability under acidic conditions. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides useful information for research into bacterial pathogenesis, fermentation and food preservation.

Adaptation, Physiological↗