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Biomedical subjects

T Nishida

Publications and source records attributed to T Nishida.

At least 181 records · Page 10Linked to original sources
PubMed1999

Transcriptional regulation of the Bacillus ohbensis cyclodextrin glucanotransferase gene in B. subtilis.

The expression of the cyclodextrin glucanotransferase (CGTase) gene (cgt) of Bacillus ohbensis, when introduced into an alpha-amylase-defective strain of B. subtilis on a multicopy plasmid, pHY300PLK, was induced in the presence of starch and was subject to catabolite repression by glucose as well as in the original strain, B. ohbensis. We constructed a cgt'::'lacZ translational fusion to study the expression in B. subtilis, and this construct was confirmed to be subject to both starch induction and catabolite repression. In order to define the region involved in the regulation of the cgt gene, a series of cgt'::'lacZ gene with various lengths of deletion in the promoter region was constructed on pHY300PLK. DNA regions responsible for starch induction and catabolite repression by glucose could be separated in the deletion experiment. Primer extension analysis showed that the catabolite repression was controlled at the initiation of transcription, while the starch induction is likely to be controlled by a transcriptional termination-antitermination mechanism.

5' Untranslated Regions↗
PubMed1999

Geographical variation of the skull morphology of the common tree shrew (Tupaia glis).

Geographical variation was examined morphologically in the common tree shrew (Tupaia glis) in some Indochinese and Malayan regions. Osteometrical examination and principal component analysis elucidated the morphological differences among various populations. The populations from southern and western Thailand were distinguished morphologically from the other populations. Variation in males from south Thailand and Kuala Lumpur suggests that the Isthmus of Kra may have an influence on the variation of skull morphology. However, the Isthmus of Kra was not completely considered as a factor of geographical separation in this species, because we could not confirm the separation in skull size and shape between the localities at least in females. While, the Kanchanaburi population in western Thailand was significantly smaller than the other population in skull size, and constituted the morphologically separable group in our study.

Animals↗
PubMed1999

Morphological features of the spermatic cord in the musk shrew (Suncus murinus) with special reference to extratesticular Leydig cells.

Morphological features of the testicular artery and vein in the spermatic cord of the musk shrew (Suncus murinus) were evaluated by light microscopy, transmission electron microscopy, corrosion cast technique combined with scanning electron microscopy and immunohistochemistry. The vascular architecture in the spermatic cord of the musk shrew was simple. The testicular artery in the musk shrew was straight and accompanied by 1 to 3 branches of testicular vein. The testicular vein was also straight and anastomosed with each other in some points along its length, but it did not form a delicate pampiniform plexus. In the middle and distal portions of the spermatic cord, the tunica adventitia of the artery and vein was joined together to form a single connective tissue septum. Clusters of cells were found in this connective tissue septum in the middle portion of the cord. These cells were located close to the arterial wall and nerve endings, but they did not appear inside of neurium. They showed several typical characteristics similar to Leydig cells, and they were positive for 3beta hydroxysteroid dehydrogenase (HSD) antibody. Ultrastructural and immunohistochemical studies also indicated that the cells in cluster found in the vascular wall of the musk shrew spermatic cord may be equivalent to Leydig cells in testes. These extratesticular Leydig cells had characteristics of the active steroid-producing cell and seemed to be another source of testosterone.

3-Hydroxysteroid Dehydrogenases↗
PubMed1999

Expression of the spermatid-specific Hsp70 antigen is conserved in mammals including marsupials.

The anatomical location of testes in mammals ranges from a location close to that observed in the embryo to a lower position usually involving a pendant scrotum. In scrotal mammals, the abdominal position of the cryptorchid testis, which elevates its temperature, is detrimental to spermatogenesis and causes infertility. Spermatocytes are sensitive but late spermatids are relatively resistant to thermal stress suggesting that the latter might be protected in some way. In general, most organisms express Hsp70 proteins, which play a crucial role in the protection of cells against thermal stress. We have found previously that the Hsc70t protein, a member of the Hsp70 family of proteins, is constitutively expressed in the late spermatids of mice. Here, we have utilized immunohistochemistry with anti-mouse Hsc70t antiserum to examine the expression of the spermatid-specific Hsp70 antigen in the testes of several mammalian species with different degrees of testes migration. Our data indicate that the antigen is conserved in the mammals including marsupials. We also examined whether antigens of Hsp70-related proteins were expressed in non-mammalian vertebrates including not only homoiothermal but also poikilothermal animals. The spermatid-specific Hsp70 antigens were not detectable in the testes of the animals examined. From results of immunohistochemistry with BRM22 monoclonal antibody which reacts broadly with Hsp70 family proteins, however, we revealed constitutive expression of antigens of Hsp70-related proteins in spermatogenic cells of the vertebrates. These results suggest that the expression of spermatid-specific Hsp70 protein may be involved in the developmental pathway during spermiogenesis in mammals rather than in thermotolerance.

Animals↗
PubMed1999

Immunohistochemical survey of the gut endocrine cells in the common tree shrew (Tupaia belangeri).

Regional distribution and relative frequency of endocrine cells in the gastrointestinal tract of the common tree shrew (Tupaia belangeri) were studied immunohistochemically. Ten types of immunoreactive endocrine cells were localized in the gastric mucosa, i.e., chromogranin-, serotonin-, gastrin-, somatostatin-, bovine pancreatic polypeptide (BPP)-, enteroglucagon-, pancreatic glucagon-, peptide tyrosine tyrosine (PYY)-, motilin-, and substance P (SP)-immunoreactive (IR) cells. In the intestine, 13 types of immunoreactive cells were observed, i.e., chromogranin-, serotonin-, somatostatin-, gastrin-, BPP-, enteroglucagon-, PYY-, secretin-, cholecystokinin (CCK)-, gastric inhibitory peptide (GIP)-, motilin-, neurotensin-, and SP-IR cells. The regional distribution and relative frequency of the cell types varied along the gastrointestinal tract. Basically, the types, distribution, and relative frequency of the gut endocrine cells were similar to those reported in other mammalian species. However, some characteristic findings were noted in the present study: (1) the considerably large number of gastrin-IR cells in the pyloric region; (2) numerous serotonin-IR cells in the stomach; (3) appreciable number of BPP-IR cells in the transitional region of the stomach; and (4) wide distribution of PYY- and motilin-IR cells in the gut.

Animals↗
PubMed1999

Osseointegration around titanium screws placed into the areas between guided bone augmented sites compared with osseointegration around guided bone graft augmented sites in rabbit tibia.

The aim of this study was to compare the degree of osseointegration around titanium screws placed into the areas between guided bone augmented sites and guided bone graft augmented sites in 8 Japanese white rabbit tibia. The skin and periosteum were incised and lifted to expose the inner surfaces of both tibia. Eight rabbits were divided into 2 groups: 1) a guided bone augmentation (GBA) group of 2 rabbits, and 2) a guided bone graft augmentation (GBCA) group of 6 rabbits. In the GBA group, the bone marrow was penetrated several times in both tibial bones. Three titanium screws were inserted into the bone so that the top of each screw was 3 mm above the bone surface and covered with an expanded polytetrafluoroethylene membrane (ePTFE). In the GBGA group autogenous cortical bone (10 mm x 10 mm x 1 mm) was taken from the left tibia and grafted on the inner surface of the right tibial bone, titanium screws being similarly inserted. The surgical site was covered by ePTFE. After healing for 2 months, the animals were euthanatized, and the experimental area was prepared for histological investigation. New bone had formed on the surgical sites in the GBA group and grafted bone had survived in the GBGA group, with no sign of infection or membrane exposure. The degree of osseointegration around the screw was 67.6 +/- 11.2% (mean +/- SD) in the GBA group and 78.8 +/- 11.9% in the GBGA group. There was no significant difference between the groups (p = 0.29). The ratio of mineralized bone to bone marrow was 45.7 +/- 6.2% in the GBA group and 64.4 +/- 4.4% in the GBGA group. There was a significant difference between the groups (p < 0.05). Although there was no significant difference for osseointegration around the screw placed into the GBA and GBGA sites, the quality of newly generated bone or grafted bone was quite different. Therefore, we suggest that predictable bone augmentation beyond the bone surface can be achieved by either the GBA or the GBGA procedure with ePTFE. However, it was difficult to conclude which procedure was superior with respect to the osseointegration around the titanium screw.

Animals↗
PubMed1999

Serous adenocarcinofibroma of the ovary--report of two cases and review of the literature.

We investigated the clinical and histologic characteristics of patients with ovarian serous adenocarcinofibroma. Because the tumors in both cases contained fibroma components; they were hard and clinically indistinguishable from uterine myoma, even by computed tomography. Both patients experienced relapses associated with tumors that originated outside the abdominal cavity (the subcutaneous abdominal wall in case 1, and the inguinal lymph nodes in case 2). The serum level of CA125 was normal or only moderately elevated at the first onset and relapse. The present cases suggest that the diagnostic features and clinical course differ between ovarian serous adenocarcinoma and serous adenocarcinofibroma.

Adenocarcinoma↗
PubMed1999

Kinetics of tissue and serum matrix metalloproteinase-3 and tissue inhibitor of metalloproteinases-1 in intervertebral disc degeneration and disc herniation.

We have evaluated the correlation between disc herniation or degeneration and the levels of matrix metalloproteinase-3 (MMP-3) or tissue inhibitor of metalloproteinases-1 (TIMP-1). The lumbar discs obtained from 22 autopsied cadavers and 21 patients with lumbar disc herniation were examined. Immunohistochemical study: The number of MMP-3-producing and TIMP-1-producing cells increased as disc herniation or degeneration progressed. Zymography: Activated type MMP-3 was observed in the normal and herniated intervertebral disc excluding the intervertebral disc with protrusion-type herniation. RT-PCR: The MMP-3 gene was expressed in all groups. However, the expression of the TIMP-1 gene was weak in the normal group as well as in the protrusion type disc herniation. Determination of tissue and serum levels of MMP-3 and TIMP-1 was increased as disc degeneration or herniation progressed. There were positive correlations between the number of MMP-3-producing or TIMP-1-producing cells in the intervertebral disc and the tissue or serum levels of MMP-3 and TIMP-1. These results suggested that MMP-3 and TIMP-1 were closely related to the progression of disc degeneration or herniation. The results also suggested that MMP-3 and TIMP-1 exhibited similar kinetics. Moreover, the serum levels of MMP-3 and TIMP-1 reflected the progression of disc degeneration and herniation.

Adolescent↗
PubMed1999

Conjunctival AL amyloidosis associated with a low-grade B-cell lymphoma.

A rare case of localized amyloidosis associated with a low-grade B-cell lymphoma involving the conjunctiva is described. Although infiltrating small lymphocytes and plasma cells showed little cytological atypia, molecular genetic examination revealed a prominent B-cell clonal immunoglobulin heavy chain (IgH) gene rearrangement in the tumor tissue. Immunoelectronmicroscopic examination showed immunoglobulin lambda light chain specificity in the amyloid deposit and Russell bodies in the surrounding plasma cells. We concluded that the immunoglobulin lambda light chain, produced by the tumor's differentiated plasma cells, is the precursor protein of the localized amyloidosis found in this case.

Amyloidosis↗
PubMed1999

[A case of noninflammatory corneal edema following anterior-posterior radial keratotomy successfully treated by topical steroids].

BACKGROUND: Corticosteroids seems to affect the functions of corneal endothelial cells directly in addition to its anti-inflammatory effect. CASE: A 69-year-old male presented with left blurred vision and decreased visual acuity in both eyes. He had undergone anterior-posterior radial keratotomy for myopia in both eyes 40 years before. Both eyes showed mild corneal stromal edema in the pupil area. We diagnosed the condition as corneal edema secondary to cell loss and dysfunction of corneal endothelium after surgery. The stromal edema further advanced in the left eye one month later. The corneal thickness increased from the initial value of 619 to 631 microns. The corrected visual acuity decreased from 0.5 to 0.06. There were no signs suggesting inflammatory reaction. The left eye was then treated with topical corticosteroids as eye-drops and by subconjunctival injection. The corneal thickness decreased to 546 microns two months later with improvement of visual acuity to 0.5. CONCLUSION: This case illustrates that topical corticosteroids may be effective for corneal edema through their anti-inflammatory effect and possible activation of the endothelium.

Administration, Topical↗
PubMed1999

[Resected case of synchronous double cancer of lung and ovarium].

A 45-year-old woman was admitted to our department for a tumor shadow in the right lung on chest rentogenogram and chest CT. Detailed examination led to the diagnosis of simultaneous lung cancer and ovarian cancer. No abnormality was found in the liver. Serum AFP level was 113.8 ng/ml preoperatively, but deceased upper lobectomy of the right lung to 11.4 ng/ml on the 15th day postoperatively. Immunohistochemical study revealed positive staining of carcinoma cells with anti AFP serum.

Adenocarcinoma↗
PubMed1999

[Morphological changes in rabbit corneal endothelium after surgical injuries].

PURPOSE: To understand the responses of the corneal endothelium to different types of surgery, we chronologically investigated the morphologic changes in the endothelial cells. METHODS: We did a mechanical incision, epithelial ablation, and excimer laser radiation on rabbit corneas and observed the morphologic changes in the endothelial cells for up to 2 weeks after surgery under a light microscope and an electron microscope. RESULTS: Although we observed enlarged intercellular spaces between neighboring endothelial cells, intercellular adhesion kept the cells tightly joined near their apexes immediately after each procedure. No signs of endothelial cell degeneration were observed after the procedures, but we did observe many Golgi apparati, rough-surfaced endoplasmic reticula, and secreted granules, indicating that the cells had been activated. After each procedure, the intercellular junctions and spaces required different amounts of time to return to normal. CONCLUSIONS: These results suggest that the different kinds of surgical injuries affected the corneal endothelium but that the changes were reversible.

Animals↗
PubMed1999

[Two cases of hearing disorder following general anesthesia].

Hearing impairment is not often considered as a potential complication of general anesthesia, despite several reports of post-operative sensorineural hearing loss. These disorders have occurred after otological as well as cardiobypass surgery. We experienced two patients both of whom had undergone orthopedic surgery. In both cases the patients experienced bilateral reversible hearing impairment after general anesthesia with nitrous oxide. It is likely that a change in the middle ear pressure as a result of Eustachian tube dysfunction may have caused transient conductive hearing loss added to sensorineural hearing disorder. After these cases we interviewed a series of 115 patients who had undergone general anesthesia to assess the extent of this problem. Contrary to our expectation, 7 patients complained of ear fullness or autophony after inhalation of nitrous oxide, although these symptons diminished within 24 hours. It is important to be aware of the possibility of hearing impairment when nitrous oxide is used especially if the patient has a history of a previous middle ear disease.

Aged↗
PubMed1999

Thermosensitivity, incidence of apoptosis and accumulations of hsp72 and p53 proteins of murine L cells in wild type status of p53 gene.

Murine L cells showed markedly high lethal thermosensitivity. Survivals from fractionated heating at 44 degrees C with variety of interval time at 37 degrees C (44 degrees C for 10 min--variety of interval time at 37 degrees C-44 degrees C for 10 min) increased markedly in accordance with elongation of the internal time; i.e. survival fraction of 0.9% from 44 degrees C for 20 min alone without the interval time to those of 25% from the fractionated heating with interval time at 37 degrees C for 3-10 hrs. Incidence of apoptosis of the L cells from heating at 44 degrees C for 6.5 min (LD50) increased from 7% immediately after the heating to 30% 6-12 hrs after the post-incubation time at 37 degrees C. Accumulation of both hsp72 and p53 proteins markedly increased after a heating at 44 degrees C for 10 min alone in accordance with elongation of post-incubation time at 37 degrees C, representing a peak 6 hrs after the post incubation. Status of p53 gene in L cells were determined with Reverse Transcription-Polymerase Chain Reaction-Single Strand Conformational Polymorphism (RT-PCR-SSCP), i.e. wild type.

Animals↗
PubMed1999

Specific aqueous humor factors induce activation of regulatory T cells.

PURPOSE: To examine the possibility that aqueous humor-induced regulatory T cells could function in vivo, these T cells were examined for their ability to suppress adoptive transfer of delayed-type hypersensitivity (DTH). To begin to understand the mechanisms by which aqueous humor induces activation of regulatory T cells, alpha-melanocyte stimulating hormone (MSH) and transforming growth factor (TGF)-beta2 were examined for ability to induce regulatory T cells. METHODS: Primed T cells were treated with aqueous humor and assayed for regulatory activity by injecting them intravenously along with DTH-mediating T cells into syngeneic mice. Antigen-pulsed antigen-presenting cells (APCs) were injected into the pinna of the mouse ear, and swelling was measured 24 hours later. Primed T cells were also activated in vitro in the presence of alpha-MSH, TGF-beta1, or TGF-beta2 and were assayed for proliferation and TGF-beta production along with suppressing DTH. RESULTS: Aqueous humor-treated T cells suppressed inflammation mediated by DTH T cells. Maximum regulatory T cell activity was induced when primed T cells were activated in vitro in the presence of alpha-MSH followed 4 hours later with active TGF-beta2. Such T cells proliferated, produced TGF-beta, and suppressed DTH, suggesting that alpha-MSH and TGF-beta2 induce activation of regulatory T cells. No regulatory T cell activity could be induced in the presence of TGF-beta1. CONCLUSIONS: The ocular microenvironment constitutively produces immunoregulatory factors that suppress the induction of inflammatory activity and promotes regulatory T cell activity. Such regulatory T cells can further contribute to maintaining the normal immunosuppressive ocular microenvironment through their ability to suppress activation of other inflammatory T cells.

Adoptive Transfer↗
PubMed1999

[Pathophysiology and management of pulmonary emphysema].

The predominant physiological abnormalities of pulmonary emphysema are chronic airway obstruction, hyperinflation of the lung, decrease of lung elastic recoil, and impaired gas exchange. Patient who still smokes must be advised and supported in an effort to stop smoking before medical treatment. The treatment goals are to induced bronchodilation, decreased the inflammatory change and promote expectoration to prevent the progressive deterioration in lung function and improves quality of life. Inhaled beta 2-agonists, anticholinergics, and oral theophylines, as bronchodilators improved exertional dyspnea and exercise tolerance. Inhaled and oral corticosteroids have an anti inflammatory effect for chronic airway inflammation. Comprehensive respiratory treatments including home oxygen therapy and rehabilitation are also successfully applied for these patients.

Adrenergic beta-Agonists↗
PubMed1999

[Localization of extracellular matrix proteins after holmium YAG laser radiation in rat cornea].

PURPOSE: To understand corneal responses to holmium YAG (Ho: YAG) laser radiation, we used immunofluorescent microscopy to examine changes in the localization of extracellular matrix proteins. METHODS: Rats were radiated with an Ho: YAG laser. On days 1, 3, and 7 after radiation, the eyes were enucleated and frozen. The cryosections were stained by immunofluorescent microscopy using antibodies against type I collagen, fibronectin, type IV collagen, and laminin. RESULTS: One day after Ho: YAG laser radiation, contraction of the stromal collagen fibrils was observed. Keratocytes could not be observed at the radiated stromal region on day 1 after radiation. One week after radiation, keratocytes returned to the radiated area. Although the stromal collagen fibrils were contracted, they were stained by an antibody against type I collagen. Dense fluorescence for fibronectin was observed at the margin of the stromal acellular zone. Both laminin and type IV collagen were observed at the basement membrane under the corneal epithelium regardless of whether the corneas were radiated or not. CONCLUSIONS: These results suggest that Ho: YAG laser radiation might be useful for collagen contraction of the stroma, without causing serious damage to the corneal epithelium or the basement membrane.

Animals↗