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Biomedical subjects

Y Tajima

Publications and source records attributed to Y Tajima.

At least 91 records · Page 5Linked to original sources
PubMed1997

Phalangeal intraosseous well-differentiated osteosarcoma of the hand.

A case of intraosseous well-differentiated osteosarcoma in one phalanx of the hand is reported. A 78-year-old man noticed swelling in the little finger of his right hand approximately 7 years before referral. Imaging disclosed a tumour with a "ground glass" appearance and irregular mottled calcification occupying almost all of the phalanx marrow and suggested slight invasion into the soft tissue. Open biopsy suggested a diagnosis of well-differentiated fibroblastic osteosarcoma. The finger and its metacarpal bone were amputated and a tumour measuring 3.5 x 2.2 x 2.0 cm and with an indistinct soft tissue margin was found in the bone marrow. Histologically, the tumour was composed of fibroblastic cells with few mitoses, and neoplastic bone formation was apparent. Although the tumour appeared to be a fibrous dysplasia, the presence of nuclear atypia, hypercellularity, and the absence of a typical woven bone pattern in addition to the soft tissue invasion indicated otherwise. Ultrastructural examination showed focal myofibroblastic differentiation, and immunohistochemistry revealed smooth muscle actin, vimentin, osteocalcin, osteonectin and MIBI in the tumour cells. This ultrastructural and immunohistochemical study is believed to be the first detailed report of an intraosseous well-differentiated osteosarcoma of phalangeal bone.

Actins↗
PubMed1997

Assignment of the possible HTLV receptor gene to chromosome 17q21-q23.

We have determined the HTLV (Human T-cell leukemia virus) receptor localization more precisely on the human chromosome 17. Based on the fact that HTLV infection induces syncytium formation of infected cells as a result of interaction between the viral envelope and viral receptor, we performed the sensitive biological assay using recombinant vaccinia expression system. Our results from the induced syncytium pattern of the somatic hybrid cell lines with different deletions indicated that the HTLV receptor gene may reside from q21 to q23 on the long arm of the human chromosome 17.

Animals↗
PubMed1997

Regulation of CREB phosphorylation by cAMP and Ca2+ in parotid acinar cells.

Since various secretory stimuli regulate not only secretion but also protein, RNA, and DNA syntheses in salivary glands, we evaluated the effect of secretory stimuli on the phosphorylation state of CREB (cAMP response element-binding protein). Isoproterenol, forskolin, and CPS-cAMP markedly stimulated the phosphorylation of CREB in parotid acinar cells, and PKA inhibitors H-8 and H-89 dose-dependently inhibited it. In contrast, carbachol (CCH) and A23187 decreased CREB phosphorylation, but CCH did not decrease it in the absence of extracellular Ca2+. Although protein phosphatase inhibitor calyculin A alone markedly increased the phosphorylation, it could not prevent CCH-induced dephosphorylation of CREB. CaM kinase IV, a putative protein kinase for CREB in response to Ca2+ elevation, was undetectable in parotid acinar cells.

Adrenergic beta-Agonists↗
PubMed1997

In-vitro ranking of the efficacy of antimicrobial agents.

A new 'drug efficacy score' was devised to compare the in-vitro efficacy of various drugs. The score is easily calculated from an MIC correlogram; strains positioned above the diagonal of the correlogram are positively scored and those positioned below are given negative scores. Each score is multiplied by the number of corresponding strains, and all such products are summed.

Anti-Bacterial Agents↗
PubMed1997

Ameloblastic fibrosarcoma arising de novo in the maxilla.

An ameloblastic fibrosarcoma (AFS) arising in the maxilla of a 14-year-old male is described. The tumor originated from the alveolar bone of the right maxilla with no apparent history of pre-existing lesion. Histologically, the lesion was composed of benign-appearing epithelial islands and strands scattered within an exceedingly cellular mass of mesenchymal tissue comprising a large number of stellate-and spindle-shaped fibroblast-like cells with marked pleomorphism. Occasional cementum-like calcification was also noted. Immunohistochemically, the neoplastic mesenchymal cells were positive only for vimentin, whereas the ameloblast-like epithelial component showed a distinctly positive reaction for wide-spectrum keratin and squamous cytokeratin. Clinicopathological features of the current case, as well as previously reported examples of AFS originating from the maxilla, are briefly discussed.

Adolescent↗
PubMed1997

An automatic flow controller for a centrifugal blood pump.

To regulate the perfusion flow rate of a centrifugal blood pump, a microcomputer controller was developed. The computer monitored the flow rate of the pump with an electromagnetic flowmeter or an ultrasonic pulse Doppler flowmeter, rotational speed of the pump, aortic pressure, and the amount of blood in a reservoir. A discrete integral controller with a control interval of 1 s was adopted for the controller. For the safety of the control system, we added functions for detecting a clamp on the tubing, a dislocation of the flow sensor, or an inverse direction of the flow sensor. During a standby period, the computer calculated the rotational speed from aortic pressure to minimize the forward or the backward flow at the start of the pump perfusion. The automatic flow controller was used on 5 patients during cardiac operations and maintained the flow rate within +/-6% of the set point.

Algorithms↗
PubMed1997

Neurological manifestations of primary Sjögren's syndrome in Japanese patients.

The neurological manifestations of twenty-one Japanese patients with Sjögren's syndrome (SjS) were evaluated. All patients were women, and sixteen of the twenty-one cases (76%) demonstrated objective abnormal neurological symptoms, the most frequently observed of which was trigeminal neuropathy (50%). Multiple mononeuropathy was seen in almost one-third of the examined cases (31%). Central nervous system (CNS) involvement was observed in three cases (14%). All of these values differed greatly from those previously reported. Therefore, this study revealed characteristic features of Japanese SjS and also implied the existence of different immunopathological mechanisms associated with SjS in Japanese patients.

Adult↗
PubMed1997

Infiltrating cell profiles of sarcoid lesions in the muscles and peripheral nerves: an immunohistological study.

In order to study the pathological mechanisms of neuromuscular sarcoidosis, we carried out an immunohistochemical investigation in five cases (five muscle specimens and two sural nerve specimens). We evaluated the distribution of inflammatory mononuclear cells and major histocompatibility complex (MHC) antigen expressions. Our data showed a dominant infiltration of helper/inducer T cells (CD4-T cells), suggesting the importance of cell-mediated immune responses in neuromuscular sarcoidosis. However, we could not identify the distinct distributional patterns of T cells as reported in sarcoid lymphadenitis. This result may be attributed to the difference of the affected organs. Moreover, failure to detect class II antigens in the muscle fibers may imply the difference in pathogenic mechanism between neuromuscular sarcoidosis and other inflammatory myopathies.

Aged↗
PubMed1997

[A case of Sjögren syndrome associated with multiple mononeuritis and dysautonomia including bilateral tonic pupils].

Sjögren syndrome (SjS) is a glandular disease characterized by dry eyes and dry mouth. Extraglandular manifestations in SjS are also common, and peripheral nerve involvement has been reported in 10-20% of cases. We report a case of Sjögren syndrome with bilateral tonic pupils, dysautonomia, and multiple mononeuritis. The fact that sural nerve sections, in addition to marked loss of myelinated and unmyelinated fibers, showed an increased number of infiltrating macrophages without lymphocytes and aberrant expression of HLA-DR (class II) antigen in Schwann cells was an especially interesting finding. No evidence of active vasculitis was detected. The patient was treated with corticosteroids and her condition gradually improved, as confirmed by thermography. Our findings suggested the presence of specific immunological abnormalities simultaneously involving the ciliary ganglia, autonomic ganglia, and dorsal root ganglia in this peculiar form of SjS.

Autonomic Nervous System Diseases↗
PubMed1997

Allergic granulomatous angitis (Churg-Strauss syndrome) with multiple intestinal fistulas.

A 40-yr-old man who had a known diagnosis of allergic granulomatous angitis (Churg-Strauss syndrome) and had been on steroids was found to have a stone in the common bile duct. At surgery, multiple internal fistulas were found in the small bowel. Cholecystectomy, removal of the stone in the common bile duct, and resection of the small bowel because of fistulas were performed. To our knowledge, the formation of an intestinal fistula has not been reported as a clinical manifestation of allergic granulomatous angitis. This rare condition occurs in the terminal stage of this disease.

Adult↗
PubMed1996

Epstein-Barr virus-associated undifferentiated carcinoma with lymphoid stroma of the salivary gland in Japanese patients. Comparison with benign lymphoepithelial lesion.

BACKGROUND: Undifferentiated carcinoma with lymphoid stroma (UCLS) arising in the salivary gland is a rare tumor, except for its geographic concentration among Eskimo and southern Chinese populations. Five cases of salivary gland UCLS in Japanese patients are presented here and compared with benign lymphoepithelial lesions (BLELs) with regard to their association with Epstein-Barr virus (EBV), p53 expression, and cell proliferative activity. METHODS: Formalin fixed, paraffin embedded sections of 5 cases of UCLS selected from 1676 patients with primary tumors of the major salivary gland and 7 cases of BLEL were examined using in situ hybridization for EBV-encoded RNAs (EBERs), along with immunostaining for p53 and Ki-67 (MIB-1). RESULTS: The incidence of UCLS was 0.3% among patients with major salivary gland tumors. EBER hybridization signals were strongly expressed in most of the neoplastic cells in all five cases of UCLS, whereas there was no signal in BLEL and surrounding nontumorous salivary gland tissues. All cases of UCLS showed strongly positive immunostaining for p53 in the tumor cell nuclei. By contrast, only one case of BLEL was positively stained for p53 in dysplastic epimyoepithelial cells, which showed focal immunostaining. Cell proliferative activity assessed using the Ki-67 labeling index was significantly higher in tumor cells of UCLS than in epimyoepithelial cells of BLEL. CONCLUSIONS: UCLS of the salivary gland is an extremely rare tumor in Japanese patients characterized by consistent association with EBV. Distinction between BLEL and UCLS is possible by examining for evidence of EBV infection, expression of p53, and cell proliferative activity.

Adult↗
PubMed1996

Effect of genistein on amylase release and protein tyrosine phosphorylation in parotid acinar cells.

We evaluated the role of protein tyrosine phosphorylation in amylase exocytosis from parotid acinar cells by using genistein, a tyrosine kinase inhibitor. Amylase release stimulated by isoproterenol was dose-dependently inhibited by genistein. Genistein also inhibited the exocytosis evoked by dibutyryl- or 8-chlorophenylthio-cAMP. Daidzein, a negative control agent of genistein, elicited no inhibitory effect. Isoproterenol had dual effects on protein tyrosine phosphorylation; it increased that phosphorylation of 190- and 210-kDa proteins and decreased that of a 90-kDa one. The phosphorylation was dose-dependently inhibited by genistein but not by daidzein. These results suggest that protein tyrosine phosphorylation plays a role in the process of amylase exocytosis from parotid acinar cells.

Amylases↗
PubMed1996

A new, secure drainage method from the cystic duct after choledocholithotomy using the cystic tube and the cystic clip: an experimental study.

The effectiveness of the cystic tube (C-tube) and the cystic clip (C-clip) for primary closure of the common bile duct after choledocholithotomy was examined in 10 dogs, followed by an observation period of either 3 months (n = 6) or 1 year (n = 4). No early complications were observed in any of the animals either during or after surgery. The laboratory data were within the normal range during the observation period. No bile leakage or slippage of the C-clip was evident on fistulography from the C-tube in animals examined 5 days after surgery. The tube could be pulled out easily from the cystic duct without any bile leakage or slippage of the clip. A second operation to confirm late complications showed no adhesions around the common bile duct, no bile duct stenosis similar to the Mirizzi syndrome, and no cystic changes of the bile duct or biloma. Our newly designed C-clip for primary closure of the common bile duct after a choledocholithotomy therefore appears to be beneficial and applicable to clinical patients undergoing traditional as well as laparoscopic surgery.

Animals↗
PubMed1996

Anionic properties of beta-lactam-enhancing factor on methicillin-resistant Staphylococcus aureus.

We found a Factor (factor T) in aged mixtures of tungstate and phosphate which greatly enhanced the antibacterial effects of beta-lactams upon methicillin-resistant Staphylococcus aureus (MRSA). Factor T suppressed penicillinase production and the amount of penicillin-binding protein-2' in the membrane fraction, thus sensitizing MRSA strains to beta-lactams. In addition, Factor T caused a metachromatic reaction and prolonged the blood coagulation time, indicating that it is a heparin-like polyanion. Since Factor T becomes ineffective in the presence of a polycation, a charge interaction may play an important role in the enhancing effect. One possibility is that Factor T non-specifically inhibits several anion-sensitive enzymes. Factor T inhibited several nucleotide-interacting enzymes, but not most serum enzymes.

Anti-Bacterial Agents↗
PubMed1996

Bilioenterostomy enhances biliary carcinogenesis in hamsters.

The aim of this study was to examine whether the type of bilioenterostomy enhances biliary carcinogenesis in the hamster model. Syrian hamsters were divided into the following groups; simple laparotomy (control group), cholecystoduodenostomy with dissection of the extrahepatic bile duct on the distal end of the common duct (CDDB group) and cholecystoileostomy with dissection of the extrahepatic bile duct on the distal end of the common duct (CIDB group). Following these procedures, all hamsters received N-nitrosobis(2-oxopropyl)amine. The diameter of the extrahepatic bile duct and plasma levels of cholecystokinin (CCK) were measured and the number of neoplastic lesions was counted microscopically. Proliferative effect of the procedures on the biliary epithelium was examined by proliferative cell nuclear antigen. In the CDDB group the extrahepatic bile duct was significantly dilated and carcinogenesis of the gall-bladder and extrahepatic bile ducts was enhanced. In the CIDB group the CCK bioactivity was stimulated and intrahepatic biliary duct, but not gall bladder and extrahepatic bile duct, carcinogenesis was promoted more than that observed in the CDDB group. Proliferation of the biliary duct epithelium was enhanced in both the CDDB and CIDB groups. Cholecystoduodenostomy enhanced intra- and extrahepatic bile duct carcinoma, whereas cholecystoileostomy promoted only intrahepatic bile duct carcinoma. Some factors in the intestinal juice seem to play a role in the promotion of biliary tract carcinoma.

Animals↗
PubMed1996

Perforated patch-clamp recording in cardiac myocytes using cation-selective ionophore gramicidin.

Whole cell currents were recorded in single myocytes dissociated from guinea pig ventricles by the patch-clamp technique. The addition of 0.1 mg/ml gramicidin D, a cation-selective ionophore, into the pipette solution induced a gradual spontaneous perforation of the patch membrane under a conventional cell-attached configuration. The access resistance, measured at approximately 12 min after formation of a gigaohm seal, was 9.2 +/- 1.5 M omega (n = 12). The perforated patch membrane exhibited ionic selectivity for various monovalent cations, with a relative order of Cs+ (1.11) > K+ (1.0) > Na+ (0.65) >> tris(hydroxymethyl)aminomethane+ (approximately 0) but was not permeable for Cl-. Under the gramicidin-perforated patch recording configuration, the cells showed the typical electrophysiological properties for ventricular cells reported previously. The intracellular Cl- concentration, estimated from the reversal potential of the catecholamine-induced Cl- current, was 36.3 +/- 2.9 mM (n = 17). We thus conclude that the gramicidin-perforated patch recording mode provides a useful tool for recording the ionic currents while maintaining the intracellular Cl- concentration.

Action Potentials↗