Search PubMed⌕ Search

Biomedical subjects

Y Takano

Publications and source records attributed to Y Takano.

At least 271 records · Page 15Linked to original sources
PubMed1994

Epstein-Barr-virus-associated medullary carcinomas with lymphoid infiltration of the stomach.

The association of Epstein-Barr virus (EBV) with gastric medullary carcinoma with lymphoid infiltration (GMCL) was investigated. The presence of GMCL exhibited a 2/1 male-to-female ratio and a 1/2 early-to-advanced cancer ratio, predominantly located in the cardia and corpus of the stomach (90%). The presence of EBV DNA could be proven in 28 out of 30 GMCL cases (93%) by the polymerase chain reaction method, and in 27 cases (90%) latent infection of EBV strictly limited to cancer cells was identified by in situ hybridization with RNA using an EBV-associated small RNAs (EBERs) probe. No histopathological difference was noted between EBERs-positive and -negative groups. Monoclonal EBV infection, identified by the length of lymphocyte-determined membrane antigen variable tandem repeats, was suggested in 19 out of 27 EBERs-positive cases (70.3%). However, only one case showed a positive reaction for anti-(latent membrane protein)-1 antibody, and none of the EBERs-positive cases bound anti-EBNA-2 antibodies, the respective antigens being considered oncoproteins directly linked with EBV-related B cell lymphomagenesis. In conclusion, while EBV is clearly present at extremely high incidence in GMCL, having characteristics biological features, a role for EBV in tumorigenesis of such lesions remains uncertain.

Antigens, Surface↗
PubMed1994

Serum and urinary neopterin as markers in renal transplant patients.

For monitoring neopterin levels, serial serum and urinary samples were obtained from 21 renal transplant patients. In renal transplant patients, serum neopterin levels were significantly higher than in healthy volunteers, even though in a clinically stable state urinary neopterin levels were also higher than in healthy volunteers, but statistically not significantly. In cases with rejection, both serum and urinary neopterin levels were significantly more elevated than in the stable state. In contrast, serum and urinary neopterin levels were not elevated in nephrotoxicity events. These results suggest that serum and urinary neopterin levels might be valuable indicators of acute rejection. Moreover, they could be useful for differentiating acute rejection from nephrotoxicity episode.

Acute Disease↗
PubMed1994

Dense innervation of human radicular dental pulp as revealed by immunocytochemistry for protein gene-product 9.5.

Protein gene-product 9.5 (PGP 9.5) is a novel neurone-specific protein. At light- and electron-microscopic levels, human radicular dental pulp was heavily innervated by PGP 9.5 nerve fibres. Thick nerve bundles showing intense PGP 9.5 immunoreactivity ascended in the centre of the pulp, with some nerve fibres extending from the trunk towards the peripheral pulp at regular intervals. However, the fibres did not form a plexus (of Raschkow) beneath the odontoblast cell layer. The PGP 9.5-positive nerve fibres penetrated into the predentine and dentine beyond the odontoblast cell layer where some nerves terminated. In the predentine, PGP 9.5-positive nerve fibres were densely distributed. In tangential sections along the pulpodentinal border, the nerve fibres ran in contact with odontoblast processes. Immunoelectron microscopy revealed that all nerve fibres were immunoreactive for PGP 9.5 in the radicular predentine and dentine, and terminated in contact with the odontoblast cell processes. The distribution pattern and terminal formation of predentinal and dentinal nerves were identical to those of coronal pulp, as reported previously. The dense innervation in radicular dental pulp, overlooked in previous reports, might be responsible for dentine hypersensitivity.

Adolescent↗
PubMed1994

Nucleolar organizer regions in bladder cancer: application to urinary cytology.

OBJECTIVES: We investigated the relationship between the numbers of nucleolar organizer regions (NORs) in nonmalignant reactive cells and those in transitional cell carcinomas using urinary exfoliated cell specimens. Another aim of this study was to determine whether higher numbers of NORs are correlated with tumors with higher pathologic grade. METHODS: Nucleolar organizer regions, which are important for regulating protein synthesis, were counted by means of a silver staining technique in urinary exfoliated cells from 34 patients with transitional cell carcinoma (TCC) and in 30 patients with other urologic diseases (controls). RESULTS: The number of argyrophilic proteins of the nucleolar organizer region (Ag-NORs) per cell (mean +/- SD) was 2.9 +/- 0.5 in the control group and 5.5 +/- 1.9 in patients with TCC, which was significantly higher than that in the controls (p < 0.001). It was 4.0 +/- 1.0 in patients with grade 1 TCC, 5.4 +/- 2.0 in those with grade 2 TCC, and 6.5 +/- 1.2 in those with grade 3 TCC. Although no statistically significant difference was observed between the groups, the patients with grade 2 TCCs with higher numbers of Ag-NORs showed a tendency to have more diffuse and/or invasive lesions. CONCLUSIONS: This method is simple and quick, and can identify low-grade malignancy. It could be used as a tool for further grading of grade 2 TCCs and for determining prognosis.

Adult↗
PubMed1994

Induction of oesophageal and forestomach carcinomas in rats by reflux of duodenal contents.

A study was designed to determine whether oesophageal carcinomas can be induced through reflux of duodenal contents. Male Wistar rats weighing 230-250 g were divided into three groups according to the surgical procedure performed: (1) the duodenal contents were directed into the forestomach through a stoma (duodeno-forestomach reflux); (2) the duodenal contents were regurgitated into the forestomach through the glandular stomach (duodeno-glandular-forestomach reflux); and (3) a sham operation was performed as a control. Animals were fed standard CRF-1 solid food and tap water that was not exposed to carcinogens and were sacrificed 50 weeks post-operatively. While no neoplasia was observed in any of the 32 control rats, 4/11 (36%) with duodeno-forestomach reflux and 3/18 (17%) animals with duodeno-glandular-forestomach reflux developed carcinomas in the lower oesophagus and forestomach. The incidence in each group was significantly higher than in the controls (P < 0.01 and P < 0.05 respectively). Six of the seven lesions consisted of squamous cell carcinomas, and one was a mucinous adenocarcinoma. Oesophageal columnar epithelial metaplasia was observed in two (18%) of the animals with duodeno-forestomach reflux. Carcinomas were always surrounded by chronic inflammatory changes, including regenerative thickening, basal cell hyperplasia and dysplasia. Additional well-differentiated adenocarcinomas were observed in the prepyloric antrum of 6/18 (33%) animals with duodeno-glandular-forestomach reflux. These findings indicate that chronic reflux of duodenal contents may cause oesophageal carcinoma.

Adenocarcinoma, Mucinous↗
PubMed1994

Identification and analysis of the Saccharomyces cerevisiae SYR1 gene reveals that ergosterol is involved in the action of syringomycin.

A 2.5 kb DNA fragment of the Saccharomyces cerevisiae SYR1 gene was cloned by complementation of the syr1 mutations that simultaneously lead to resistance to the phytotoxin syringomycin and sensitivity of growth to high Ca2+ concentrations. Sequencing of this fragment revealed a single open reading frame encoding a polypeptide of 365 amino acids. Four hydrophobic regions each separated by hydrophilic regions were present in the protein. SYR1 was identical to ERG3, which is suggested to encode C-5 sterol desaturase required for ergosterol biosynthesis. The protein product of SYR1 was identified by Western blot analysis as a protein of 40 kDa in the particulate fraction. Gene disruption experiments demonstrated that elimination of SYR1/ERG3 is not lethal, but results in membrane C-5 desaturated sterol deficiencies, resistance to syringomycin and sensitivity to high Ca2+. The syr1 mutant cells had significantly decreased ability for syringomycin binding. The results indicated that C-5 desaturated sterols are involved in the binding of syringomycin to the cell, and the lack of the sterols in the mutant membrane results in sensitivity to high Ca2+ and an increased rate of cellular Ca2+ influx.

Bacterial Proteins↗
PubMed1994

Interferon-gamma stimulates neopterin release from cultured kidney epithelial cells.

The ability of cultured kidney epithelial cells (KEC) to secrete neopterin, which is a marker of the activation of immune system was studied. In this study interferon gamma (IFN-gamma) was shown to induce neopterin release from KEC in a dose- and time-dependent manner. Many other cytokines and mitogens (IL-1 beta, IL-2, IL-6, LPS and phorbol ester) were tested for their ability to induce neopterin in KEC but all failed to induce a significant release of neopterin from KEC. By itself TNF-alpha induced a release of small amounts of neopterin but strongly potentiated the effect of IFN-gamma in a synergistic manner to induce neopterin secretion. These data indicate that not only monocytes and macrophages which it is well known secrete neopterin, but KEC are responsible also for the high serum or urine level of neopterin observed in patients with kidney allograft rejection or infections episodes. As the amount of neopterin released by KEC is smaller than that secreted by activated macrophages, the contribution of KEC to the overall production of neopterin during certain diseases may be small.

Biopterins↗
PubMed1994

Congenital patent urachus in an adult: a case report.

A rare case of the congenital patent urachus in an adult is reported. The patient, a 42-year-old man, was admitted with the chief complaint of macroscopic hematuria. During the cystoscopy perfusion water discharged from the umbilicus. Diagnostic imaging revealed a tubular fistula between the bladder and umbilicus and the patient underwent urachal resection and partial cystectomy. Microscopically the lumen was lined by transitional, columnar and squamous epithelium and there was no evidence of malignancy. To date 11 cases of congenital patent urachus in an adult have been reported in Japan. From a review of the Japanese literature, the common chief complaint is urine discharge from the umbilicus accompanying cystitis and/or urachal inflammation. Urachal resection is performed in all cases. We also clarified the epithelial histology of the patent urachus in this patient.

Adult↗
PubMed1994

Evidence for the existence of intraepithelial nerve endings in the junctional epithelium of rat molars: an immunohistochemical study using protein gene product 9.5 (PGP 9.5) antibody.

Innervation of the junctional epithelium was investigated in rat molars by means of immunohistochemistry for protein gene product 9.5 (PGP 9.5) at light and electron microscopic levels. In comparison with our previous study on same tissues using neurofilament protein (NFP)-antibody, the PGP 9.5-immunostaining further disclosed numerous nerve fibers in the gingiva of rat molars and revealed the existence of a well-developed plexus of PGP 9.5-positive nerve fibers. The interproximal portion also contained numerous nerve fibers. Observation of horizontal sections revealed a denser innervation toward the inner junctional gingival epithelium than the outer marginal epithelium. The nerve fibers, beaded in appearance and extending from the nerve bundles in the lamina propria, penetrated into the junctional epithelial layer and were distributed throughout the junctional epithelium, with some nerves being located near the epithelial surface. Non-neuronal cells showing PGP 9.5-immunoreactivity were absent in the junctional epithelium. In immunoelectron microscopy, the axoplasm of nerves in the gingiva was filled with electron-dense reaction products of PGP 9.5, except for the cell organellae. The nerve fibers were devoid of Schwann cell investment and terminated among the epithelial cells in the junctional epithelium, frequently beneath the epithelial surface. The intraepithelial nerve endings contained various kinds of vesicles including large-cored ones, supporting the presence of peptidergic innervation shown by previous studies. These findings confirmed the usefulness of PGP 9.5-immunohistochemistry for the identification of delicated nerve fibers in dental tissue, and suggested the dense network of nerve fibers that may serve as sensory receptor and other functions in the junctional epithelium.

Animals↗
PubMed1994

Perineal epidermal cyst.

This paper presents a case of perineal epidermal cyst. Diagnostic imagings by ultrasonography, CT scanning and MR imaging described the mass as a cystic tumor on the perineal median raphe. It was excised for the histological diagnosis. The removed mass was shown microscopically to be filled with laminated keratin and to be lined with differentiated cornified squamous epithelium. The pathological diagnosis was benign perineal epidermal cyst.

Aged↗
PubMed1994

The mechanism of muscarinic agonist-stimulated inositol phosphate formation in permeabilized ileal smooth muscle.

Muscarinic agonists and guanylyl-5'-imidodiphosphate (Gpp(NH)p) stimulated formation of inositol phosphates in permeabilized longitudinal smooth muscle of guinea pig ileum. Gpp(NH)p markedly potentiated the formation of inositol bisphosphate (IP2) and inositol trisphosphate (IP3) stimulated by carbachol, but increased inositol monophosphate formation (IP1) only slightly. Gpp(NH)p enhanced the formation of IP2 + IP3 induced by either acetylcholine or carbachol about fourfold in a synergistic manner, but enhanced the effects of oxotremorine and pilocarpine less than twofold in an additive manner. Elevation of Ca2+ concentration resulted in increases of the inositol phosphate levels stimulated by both carbachol and Gpp(NH)p. The optimal concentration of Ca2+ for carbachol-stimulated formations of IP2 + IP3 was shifted to a lower Ca2+ concentration in the presence of Gpp(NH)p. These findings suggest that muscarinic receptor-stimulated polyphosphoinositide hydrolysis in ileal smooth muscle results in inositol polyphosphate formation via GTP binding protein (G-protein). The muscarinic receptor-activated G-protein decreases the Ca2+ requirement of polyphosphoinositide hydrolysis. Muscarinic agonists stimulate inositol polyphosphate formation by interaction of the G-protein activation of a phosphoinositide specific phospholipase C with Ca2+ influx.

Acetylcholine↗
PubMed1994

Alterations in vascular pattern of the developing palate in normal and spontaneous cleft palate mouse embryos.

The alterations in the vascularization of the developing palate were studied through the use of resin cast images of vascular networks in normal and spontaneous cleft lip and palate (CL/Fr) mouse embryos (crown rump [CR] Length 9-18 mm, body wt. 0.11-0.65 g). A more dense vascular plexus was observed in the oral side than in the nasal side before the reorientation of the palatal shelves. Prominent terminal dilatations of the vascular plexus were observed in the extreme medial edge of the elevating palatal shelves which may exert significant force for palatal shelf elevation. The vascular plexus showed a lateral extension. Many small spherical masses of resin were observed in the medial edge of the palatal shelves at the time of medial extension and during fusion, indicating some changes occurring in the capillary wall leading to the resin leakage. In the spontaneous cleft group, a similar vascular pattern was observed, but the greater palatine artery showed discontinuity in the premaxillary region at an early stage. At the same time, terminal dilatations were delayed and frequently absent in the contralateral shelf. After the reorientation of the palatal shelves, the vascular plexus formed an irregular lattice pattern. Dilated vasculature was apparent in the anterior nasopalatine region, indicating the persistence of a more primitive vascular structure in the spontaneous cleft embryos. However, the area where capillary dilatation occurred was different between unilateral and bilateral cleft embryos. In conclusion, blood vessels in the palatal shelves are underdeveloped and remained immature in cleft lip and palate embryos and showed different patterns in the anterior nasopalatine region between unilateral and bilateral cleft embryos. These variant vascular patterns may be due to the inadequate blood supply to the nasopalatine region from the early embryonic stages possibly resulting from the discontinuity of the greater palatine artery.

Animals↗
PubMed1994

The relationship between odontoblasts and immunocompetent cells during dentinogenesis in rat incisors: an immunohistochemical study using OX6-monoclonal antibody.

The relationship between odontoblasts and class II major histocompatibility complex (MHC) antigen-expressing cells in the process of dentinogenesis was studied in rat lower incisors, employing immunohistochemistry using OX6-monoclonal antibody. The dental pulp contained numerous OX6-immunopositive cells that varied in morphology from dendritic to spindle under physiological conditions. Under the electron microscope, these immunopositive cells shared common cytoplasmic features, i.e., multivesicular bodies and characteristic fine tubulovesicular structures in their cytoplasm. At the early stage of dentinogenesis, OX6-immunopositive cells, presumably of the immature type, were located in the subodontoblastic layer. During active dentin formation, the OX6-immunopositive cells increased in number and appeared in the odontoblast layer, associating intimately with fenestrated capillaries situated close to the predentin. These cells showed a dendritic appearance and possessed various sizes of multivesicular bodies and characteristic fine tubulovesicular structures, but never contained typical phagosomes. On the other hand, immunopositive macrophages characterized by typical phagosomes tended to occupy the central portion of the pulp. The results suggest that most, if not all, OX6-immunopositive cells situated deep in the odontoblast layer are dendritic cells playing a role in the defense system of the dental pulp against antigenic molecules arriving from the circulation via the fenestrated capillaries. The increasing number of OX6-immunopositive or immunonegative macrophages appearing near the incisal end of the tooth is thought to be involved in the elimination of degenerated odontoblasts.

Animals↗