Biomedical subjects

T Kotani

Publications and source records attributed to T Kotani.

At least 37 records · Page 2Linked to original sources

PubMed2001

Estimation of lacrimal level and testing methods on normal beagles.

Five methods of testing tears including the Schirmer tear test (STT-1), phenol red thread tear test (PRT) and modified Schirmer tear test (STT-2) were conducted on 44 eyes of 22 normal Beagles, and the tear film break up time (BUT) and lacrimal pH were tested in 32 eyes of 16 normal Beagles. The coefficient of variation of PRT demonstrated a low value (C.V. 12%) [corrected] compared to the value of STT-1 (C.V. 14%) [corrected]. The lacrimal pH showed a more constant value (C.V. 3%). Measurements of STT-2 (C.V. 48%) and BUT (C.V. 34%) varied significantly. The results show the clinical usefulness of the PRT. Mean values (mean +/- SD) of tests were: PRT, 29.3 +/- 3.45 mm/15 s; STT-1, 18.89 +/- 2.62 mm/60 s; STT-2, 9.52 +/- 4.55 mm/60 s; pH, 7.29 +/- 0.22 and BUT, 21.53 +/- 7.42 s.

Animals↗

PubMed2001

Immunohistochemical analysis of macrophages and myofibroblasts appearing in hepatic and renal fibrosis of dogs.

Some peptide growth factors produced by macrophages play a role in fibrosis following tissue injury, through the induction of myofibroblasts. In the present study, the appearance of macrophages and myofibroblast development in hepatic and renal fibrosis was determined by immunohistochemical analysis of tissue from 15 dogs. The hepatic and renal fibrosis was classified as grade I, II or III, depending on the extent (percentage) of fibrotic areas per unit area measured by morphometry with Azan-stained sections. The presence of alpha-smooth muscle actin-immunolabelled myofibroblasts was directly related to advancing grade of both hepatic and renal fibrosis. Lysozyme-immunolabelled macrophages also increased in number with increasing grade of hepatic and renal fibrosis. These findings indicate that myofibroblasts and lysozyme-positive macrophages may contribute to progressive fibrosis in canine liver and kidney disease. Interestingly, the number of macrophages recognized by AM-3K, a newly generated monoclonal antibody capable of labelling exuded macrophages and resident tissue macrophages in dogs, fell significantly in grades II and III of renal fibrosis. By contrast, in hepatic fibrosis there were no marked differences in the number of AM-3K-positive macrophages between grades. These findings suggest that there are functional differences between lysozyme- and AM-3K-positive macrophages.

Actins↗

PubMed2001

Effects of lipopolysaccharide on a macrophage-like cell line (HS-P) from a rat histiocytic sarcoma.

Lipopolysaccharide (LPS) is a major modulator of macrophage functions. To characterize a newly established rat histiocytic sarcoma-derived cell line (HS-P), immunophenotypic changes and cellular growth responses of HS-P cells exposed to LPS were investigated and compared with those of MT-9 cells isolated from a rat malignant fibrous histiocytoma. MT-9 cells have somewhat histiocytic features, because occasional cells react to rat macrophage-specific antibodies. Addition of LPS to cultured HS-P cells increased the numbers of cells immunopositive to ED1 (rat macrophage-specific antibody) and ED2 (rat histiocyte-specific antibody) and stimulated the phagocytosis of latex beads, whereas LPS-treated MT-9 cells did not show such immunophenotypic changes. LPS-treated HS-P cells showed enhanced immunolabelling of alpha-smooth muscle actin, suggesting a possible modulation of macrophages towards myofibroblastic cells. To evaluate cellular growth after the addition of LPS or fetal bovine serum, DNA synthesis was examined by measuring tritiated thymidine incorporation, and the mRNA expression of c- jun and c- myc (immediate early genes in the cell cycle) was examined by Northern blot analysis. In HS-P cells, the addition of serum greatly increased DNA synthesis and induced high expression of c- jun and c- myc; in contrast, LPS markedly depressed DNA synthesis and reduced the expression of c- jun and c- myc. HS-P cells were more sensitive than MT-9 cells to the growth-promoting effect of serum and the growth-inhibiting effect of LPS. The study demonstrated that HS-P cells are highly LPS-responsive, indicating that they would be useful for studies of macrophage functions.

Animals↗

PubMed2001

Intragastric endoscopic mucosal resection through a temporary gastrostomy for early gastric cancer: usefulness of Buess-type endoscope.

OBJECTIVE: To assess the feasibility of cure of early gastric cancer by the endoscopic procedure done through a temporary gastrostomy and to use it to treat patients with various severe complications. DESIGN: Prospective study. SETTING: University hospital, Japan. SUBJECTS: Four patients who required gastric mucosal resection for early gastric cancer. MAIN OUTCOME MEASURES: Ease of the procedure, cure rate, safety under epidural anaesthesia, and outcome. RESULTS: All patients had the procedure under epidural anaesthesia without pain or complaints during operation. Mean operation time was 120 minutes (60-200). Histological examination showed that the surgical margin was free of tumour in 3 of the cases. One patient who had microscopic invasion of lymph nodes subsequently underwent second-look conventional gastrectomy with lymphadenectomy. Postoperative recovery was rapid, and all patients were discharged from the hospital uneventfully. CONCLUSION: This organ-preserving procedure enables good visualisation of the tumour and is useful even for high-risk patients.

Adult↗

PubMed2001

New bronchoscopic microsample probe to measure the biochemical constituents in epithelial lining fluid of patients with acute respiratory distress syndrome.

OBJECTIVE: A noninvasive bronchoscopic microsampling (BMS) probe was developed to sample biochemical constituents of the epithelial lining fluid in small airways. DESIGN: Observational, controlled study. SETTING: Intensive care unit of academic medical center. PATIENTS AND PROCEDURE: BMS was applied in a control group of seven patients who had hemoptysis or small solitary peripheral nodules but no hypoxemia or other signs of acute inflammation and in four patients with acute respiratory distress syndrome (ARDS), to test whether BMS can ascertain the presence of acute pulmonary inflammation without complications. MEASUREMENTS AND RESULTS: Complications, including a significant decrease in arterial oxygen saturation, were observed neither during nor after BMS. In the ARDS group, albumin, lactate dehydrogenase, interleukin-6, basic fibroblast growth factor, and neutrophil elastase concentrations in epithelial lining fluid were significantly higher (p <.0001, p =.012, p <.0001, p <.0001, and p <.0001, respectively) than in the control group. Serial BMS was safely performed in one patient with ARDS, allowing us to observe a correlation between changes in the concentration of inflammation-related biochemical markers and clinical course of the disease. CONCLUSIONS: These results suggest that BMS is safe and useful to monitor pulmonary biochemical events in ARDS.

Adult↗

PubMed2001

Humoral hypercalcemia of malignancy in female F344 rats implanted with a transplantable rat pulmonary carcinoma line (IP).

A transplantable rat pulmonary carcinoma line (IP) in F344 rats is a useful animal model for humoral hypercalcemia of malignancy (HHM). The present study analyzed the degree of HHM by implanting IP into F344 female rats aged 6, 20 or 45 weeks. IP-bearing females developed elevated plasma parathyroid hormone-related protein levels, hypercalcemia and increased osteoclastic activity as well as calcification in various organs. The severity of such HHM differed depending on age; particularly, calcification showed age-dependent reduction. HHM development in IP-bearing females may be influenced by age-related factors.

Age Factors↗

PubMed2001

Malignant fibrous histiocytoma (MFH) cells and macrophages/histiocytes have a common antigen recognized by a monoclonal antibody risen against a rat MFH-derived cloned cell line.

A monoclonal antibody (B9) was generated by using a rat malignant fibrous histiocytoma (MFH)-derived cloned cell line (MT-8) as the immunogen. Immunohistochemically, B9 reacted specifically with a cytoplasmic antigen of MT-8 cells. Furthermore, B9 immunolabeled another MFH-derived cloned cells (MT-9) and histiocytic sarcoma cells, as well as macrophages/histiocytes in normal and diseased tissues of rats. These findings suggest the presence of a common antigen recognized by B9 between MFH cells and macrophages/histiocytes. This suggests that MFH cells may express histiocytic nature.

Animals↗

PubMed2001

[Gross spreading multiple extramedullary plasmacytomas to the skin in the terminal stage of multiple myeloma].

A 71-year-old woman with an 8-year history of IgG-kappa type multiple myeloma was admitted because of severe lumbago and bone destruction. Her serum IgG level was elevated to 5,565 mg/dl at admission. Despite treatment with doxorubicin, vincristine, dexamethasone, melphalan and interferon-alpha, the response was transient. Nine months later, multiple skin nodules appeared on her chest, abdominal wall and right thigh accompanied by elevation of the serum IgG level. Response to combination chemotherapy with cyclophosphamide, ranimustine, vincristine and prednisolone was also transient. The skin tumors on the bilateral thighs, especially on the left side, acquired chemotherapy resistance and gradually enlarged. Although the serum IgG level was maintained by chemotherapy within the range 1, 790-2,676 mg/dl, the skin tumors on the left thigh had spread very rapidly and appeared "rock-like". The enlarged tumors caused necrosis with erosions and oozing hemorrhage. A skin biopsy from the tumors on the left thigh showed plasmacytoma in which infiltration of large anaplastic plasma cells was observed. The patient died of sepsis 8 months after the skin tumors initially developed. This is a very rare case of multiple myeloma in which multiple large plasmacytomas of the skin developed and grew aggressively at the terminal stage after a long-term indolent course.

Aged↗

PubMed2001

Expression and adhesive ability of gicerin, a cell adhesion molecule, in the pock lesions of chorioallantoic membranes infected with an avian poxvirus.

The expression and adhesive activities of gicerin, a cell adhesion protein, in the pock lesions on chicken chorioallantoic membranes (CAM) infected with an avian poxvirus were studied. In normal CAMs, gicerin was found on the flattened epithelial cells, and neurite outgrowth factor (NOF) was in the basement membrane. However, in the pock lesions on infected CAMs, gicerin was overexpressed on the cell membranes of hyperplastic epithelial cells forming thick epithelial layers. Neurite outgrowth factor was also found mainly in the basement membrane, but occasionally showed aberrant expression among hyperplastic cells. In vitro analyses, using the dissociated cells from pock lesions, demonstrated that an anti-gicerin polyclonal antibody inhibit cell aggregation activity and cell adhesion to NOF. These results suggest that gicerin might promote the cell-cell and cell-extracellular matrix protein bindings of the hyperplastic epithelial cells by its homophilic and heterophilic adhesive activities, and contribute to pock formation on the infected CAMs.

Allantois↗

PubMed2000

A role of transcriptional activators as antirepressors for the autoinhibitory activity of TATA box binding of transcription factor IID.

The TATA box-binding activity of transcription factor IID (TFIID) is autoinhibited by the N-terminal domain of the Drosophila TATA box-binding protein- (TBP) associated factor 230/yeast TBP-associated factor 145 subunit, which binds to the TATA box-binding domain of TBP by mimicking the TATA box structure. Here, we propose a mechanism of transcriptional activation that involves antirepression of this autoinhibitory activity by transcriptional activators. Like the autoinhibitory domain of TFIID, various acidic activators interact with the TATA box-binding domain of TBP. Moreover, the autoinhibitory domain of TFIID, which is known to interact with only the TATA box-binding domain of TBP, acts as an activation domain when fused to the GAL4 DNA-binding domain, indicating that interaction with the TATA-binding domain of TBP is crucial for activation of transcription. In a reciprocal fashion, the acidic activation domains can function as the autoinhibitory domain when the latter is replaced by the former within TFIID. These results indicate that activation domains and the autoinhibitory domain of TFIID are interchangeable, supporting a role for transcriptional activators as antirepressors of the autoinhibitory activity of the TATA box binding of TFIID.

Amino Acid Sequence↗

PubMed2000

Spontaneous and ethyl-nitrosourea-induced medullomyoblastomas in cerebellar vermis defect (CVD) mutant rats.

A 26-week-old female cerebellar vermis defect (CVD) rat, a mutant with cerebellar vermis defect and cerebellar dysplasia, developed a brain tumor about 10 mm in diameter. Histopathologically, the tumor consisted of diffuse proliferation of small round to ovoid cells with hyperchromatic nuclei, occasionally containing round to strap-shaped myoblastic cells. Immunohistochemically, the small round cells expressed neuron-specific enolase and synaptophysin, indicating neuronal differentiation; myoblastic components reacted to desmin, myoglobin, and vimentin. Based on these findings, the case was diagnosed as a medullomyoblastoma (MMB). Furthermore, two cerebella tumors in CVD rats, which were induced by transplacental application of ethyl-nitrosourea, showed histopathology similar to the aforementioned case. MMB is a very rare tumor in humans and animals; thus, it is noteworthy that MMBs developed in CVD rats, involving the dysplastic cerebellum with abnormal migration of external granule cells.

Animals↗

PubMed2000

Glial pathology in development of cerebellar dysplasia in the hereditary cerebellar vermis defect (CVD) rat.

The cerebellar vermis defect (CVD) rat is a new neurological mutant characterized by a cerebellar vermis defect and dysplasia in the cerebellum, especially at the cerebellopontine junctions. In this study, the cytokinetics of glia in terms of the development of cerebellar dysplasia in the CVD rat was investigated using glial fibrillary acidic protein (GFAP) and vimentin immunohistochemistry. In the cerebellar hemispheres, dislocation of the Bergmann glia was observed from postnatal day 5 (P5) in lesions with abnormally aggregated external granule cells (EGCs). Rearranging Bergmann glia were often seen around the EGCs penetrating into the white matter. In the cerebellopontine junctional areas, Bergmann glia were induced after penetration of the Purkinje cells, identified with calbindin immunohistochemistry, and EGCs into the pons from P10. Bergmann fibers were frequently arranged perivascularly. In the clusters of Purkinje cells without EGC settlement in the pons, a small number of Bergmann fibers were observed and their alignment was completely disturbed. These findings suggest that morphological changes in the Bergmann glia depend on their contact with Purkinje cells, but that the orientation of their processes may be influenced by EGC settlement. These glial fibers in the CVD rat may play an important role in the aberrant migration of EGCs, resulting in the development of cerebellar dysplasia.

Animals↗

PubMed2000

CALNUC (nucleobindin) is localized in the Golgi apparatus in insect cells.

A mouse monoclonal antibody 12B1 was raised against Golgi fractions from Sf21 insect cells and selected as Golgi-specific by immunostaining of the cells. The antigen was purified from the cells by immunoaffinity chromatography with the monoclonal antibody, and its N-terminal and internal amino acid sequences were determined. Based on the partial amino acid sequences, cDNA encoding the antigen protein was cloned and sequenced. The amino acid sequence deduced from the cDNA nucleotide sequence showed a homology to those of CALNUC family proteins, CALNUC (or nucleobindin, a calcium-binding Golgi protein with DNA-binding activity) and protein NEFA (a cell surface protein with DNA-binding, EF-hand, and acidic domains). The insect protein had two EF-hand loops at the same sites as the mammalian CALNUC family proteins, but had no leucine zipper which the mammalian homologues commonly have. An electron microscopic immunoperoxidase study demonstrated that the insect protein was localized in the cis-Golgi cisternae and cis-Golgi networks. Since this localization is identical to that of mammalian CALNUC, the insect protein was considered to be a homologue of CALNUC rather than that of NEFA. Assays involving proteinase K digestion, sodium carbonate extraction and Triton X-114 extraction revealed that the insect CALNUC-like protein was a soluble protein tightly associated with the luminal surface of Golgi membranes as reported for mammalian CALNUC. The insect protein was also shown to have calcium-binding activity as does mammalian CALNUC. These data verify that the insect protein is CALNUC. The existence of CALNUC in insect cells suggests that CALNUC is an essential calcium-binding Golgi protein in a wide range of the animal kingdom. A phylogenetic tree analysis, however, suggested that NEFA was derived from CALNUC long after the segregation of a mammalian ancestor from an insect ancestor.

Acetylglucosaminidase↗

PubMed2000

Echocardiographic diagnosis of dirofilariasis in a ferret.

Heartworm disease is described in a 14-month-old neutered female ferret (Mustela putorius furo) which had a three-week history of sneezing, anorexia and dyspnoea. Echocardiography revealed the presence of heartworms as hyperechoic densities within the right atrial and ventricular cavities. At necropsy, four Dirofilaria immitis parasites (three females, one male) were found in the right heart, the cranial vena cava and the caudal vena cava. Histopathological findings were similar to those reported in canine heartworm disease. Echocardiography may be a useful method of diagnosis of heartworm disease in the ferret.

Animals↗

PubMed2000

Cardiovascular effects of medetomidine, detomidine and xylazine in horses.

The cardiovascular effects of medetomidine, detomidine, and xylazine in horses were studied. Fifteen horses, whose right carotid arteries had previously been surgically raised to a subcutaneous position during general anesthesia were used. Five horses each were given the following 8 treatments: an intravenous injection of 4 doses of medetomidine (3, 5, 7.5, and 10 microg/kg), 3 doses of detomidine (10, 20, and 40 microg/kg), and one dose of xylazine (1 mg/kg). Heart rate decreased, but not statistically significant. Atrio-ventricular block was observed following all treatments and prolonged with detomidine. Cardiac index (CI) and stroke volume (SV) were decreased with all treatments. The CI decreased to about 50% of baseline values for 5 min after 7.5 and 10 microg/kg medetomidine and 1 mg/kg xylazine, for 20 min after 20 microg/kg detomidine, and for 50 min after 40 microg/kg detomidine. All treatments produced an initial hypertension within 2 min of drug administration followed by a significant decrease in arterial blood pressure (ABP) in horses administered 3 to 7.5 microg/kg medetomidine and 1 mg/kg xylazine. Hypertension was significantly prolonged in 20 and 40 microg/kg detomidine. The hypotensive phase was not observed in 10 microg/kg medetomidine or detomidine. The changes in ABP were associated with an increase in peripheral vascular resistance. Respiratory rate was decreased for 40 to 120 min in 5, 7.5, and 10 microg/kg medetomidine and detomidine. The partial pressure of arterial oxygen decreased significantly in 10 microg/kg medetomidine and detomidine, while the partial pressure of arterial carbon dioxide did not change significantly. Medetomidine induced dose-dependent cardiovascular depression similar to detomidine. The cardiovascular effects of medetomidine and xylazine were not as prolonged as that of detomidine.

Adrenergic alpha-Agonists↗

PubMed2000

Epithelial cell kinetics in the inflammatory process of chicken trachea infected with infectious bronchitis virus.

All stages of degeneration and regeneration in chicken tracheal epithelium were studied morphologically following an intratracheal inoculation of infectious bronchitis virus (IBV). Viral antigen was detected in the cytoplasm of tracheal epithelium from 1 to 7 days post-inoculation (d.p.i.) with a peak on 3 d.p.i. At 1 d.p.i., almost all epithelial cells were involved in the degeneration. At this time, labelling index of bromodeoxyuridine (BrdU) in the basal cells showed significantly high value compared with control. At 2 and 3 d.p.i., a great number of basal cells were recognized, but the BrdU labelling index tended to decrease. At 4 and 5 d.p.i., the BrdU labelling index of basal cells significantly decreased than 1 d.p.i., and a few number of regenerated immature ciliated epithelia appeared. At 6 to 11 d.p.i., the ciliated columnar epithelia increased rapidly in number, and returned to the normal appearance except for non-ciliated patch by 13 d.p.i. These results suggested that the tracheal epithelial cells infected with IBV degenerated within 24 hours and proliferating activity of basal cells functioned immediately, and 3 to 4 days later, these basal cells were differentiated to the ciliated epithelia.

Animals↗

PubMed2000

Combination of continuous intravenous infusion using a mixture of guaifenesin-ketamine-medetomidine and sevoflurane anesthesia in horses.

The anesthetic and cardiovascular effects of a combination of continuous intravenous infusion using a mixture of 100 g/L guaifenesin-4 g/L ketamine-5 mg/L medetomidine (0.25 ml/kg/hr) and oxygen-sevoflurane (OS) anesthesia (GKM-OS anesthesia) in horses were evaluated. The right carotid artery of each of 12 horses was raised surgically into a subcutaneous position under GKM-OS anesthesia (n=6) or OS anesthesia (n=6). The end-tidal concentration of sevoflurane (EtSEV) required to maintain surgical anesthesia was around 1.5% in GKM-OS and 3.0% in OS anesthesia. Mean arterial blood pressure (MABP) was maintained at around 80 mmHg under GKM-OS anesthesia, while infusion of dobutamine (0.39+/-0.10 microg/kg/min) was necessary to maintain MABP at 60 mmHg under OS anesthesia. The horses were able to stand at 36+/-26 min after cessation of GKM-OS anesthesia and at 48+/-19 minutes after OS anesthesia. The cardiovascular effects were evaluated in 12 horses anesthetized with GKM-OS anesthesia using 1.5% of EtSEV (n=6) or OS anesthesia using 3.0% of EtSEV (n=6). During GKM-OS anesthesia, cardiac output and peripheral vascular resistance was maintained at about 70% of the baseline value before anesthesia, and MABP was maintained over 70 mmHg. During OS anesthesia, infusion of dobutamine (0.59+/-0.24 microg/kg/min) was necessary to maintain MABP at 70 mmHg. Infusion of dobutamine enabled to maintaine cardiac output at about 80% of the baseline value; however, it induced the development of severe tachycardia in a horse anesthetized with sevoflurane. GKM-OS anesthesia may be useful for prolonged equine surgery because of its minimal cardiovascular effect and good recovery.

Anesthesia↗

PubMed2000

Kinetics of lymphocytic subsets in chicken tracheal lesions infected with infectious bronchitis virus.

The kinetics of T-cells (CD3 positive (+), CD4+ and CD8+ cells) and B-cells (IgG+, IgM+ and IgA+ cells) in chicken trachea were studied immunohistochemically and histopathologically following an intratracheal inoculation of infectious bronchitis virus (IBV). Viral antigen was detected in the cytoplasm of tracheal epithelium from 16 hr to 6 days post-inoculation (p.i.) with a peak on 4 days p.i. A few IgG+, IgM+ and IgA+ cells were detected in the submucosa from 8 hr p.i. Thereafter IgG+ and IgM+ cells were gradually increased in number, and dramatically increased from 3 days p.i., peaked on 4 days p.i., and gradually decreased after 5 days p.i. IgA+ cells were detected in a small number than IgG+ and IgM+ cells during the all experimental period. These B cells mainly existed in the lamina propria, and some cells were recognized in the interepithelial space. After 14 days p.i., small number of IgG+ and IgM+ cells were detected in the germinal center of lymph follicles in the lamina propria. From 24 to 60 hr p.i., a few number of CD3+, CD4+ and CD8+ cells were detected at the perivascular area in the lamina propria. After 3 or 4 days p.i., each positive T-cells increased rapidly in number, and reached on the peak at 5 days p.i. CD3+, CD4+ and CD8+ cells tend to distribute diffusely, perivascular area, and surrounding area of CD4+ cells, respectively. CD4+ cells were dramatically decreased from 7 days p.i., and CD3+ and CD8+ cells were decreased from 14 days p.i. No T-cells were detected in the lymph follicles in the lamina propria.

Animals↗