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M Sato

Publications and source records attributed to M Sato.

At least 541 records · Page 30Linked to original sources
PubMed2000

Involvement of apoptosis in the endotoxemic lesions of the liver and kidneys of piglets.

The involvement of apoptosis was evaluated in lesions of endotoxemic piglets. A single injection with E. coli O111:B4 lipopolysaccharide (LPS) induced foci of coagulative necrosis in the liver and kidneys. No significant change was observed in these organs at 1.5 hr after LPS injection, but at 6 hr, epithelial cells with chromatin condensation or fragmentation and apoptotic bodies were visible. Foci of coagulative necrosis were formed within 24 hr after LPS inoculation. In and adjacent to the necrotic foci, dead hepatocytes with nuclear condensation or fragmentation were scattered. These dead cells were positively stained by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling (TUNEL) methods. Electronmicroscopy revealed apoptotic cells with condensed or fragmented homogeneous nuclear chromatin, and necrotic cells with irregularly destroyed nuclei and cytoplasmic membranes. Apoptotic cell death were also observed in parietal cells of the stomach and lymphocytes in the lymphatic system. DNA ladders with approximately 200-bp multimers were observed in hepatic, renal and thymic samples prepared after 6 and 24 hr of LPS injection by agarose gel electrophoresis. These results suggest that apoptosis is involved in the pathology of swine endotoxemia.

Animals↗
PubMed2000

Incidence of Listeria monocytogenes in wild animals in Japan.

Between 1991 and 1993, the intestinal contents and feces of wild animals in Japan were examined for the presence of Listeria. The wild animals examined included 623 mammals (11 species) and 996 birds (18 species). Listeria species were isolated from 38 (6.1%) of the 623 mammalian samples and 133 (13.4%) of 996 bird samples. The highest incidence of Listeria in the mammals was found in Japanese monkeys (20.0%) and that in birds was found in crows (43.2%). The incidence of Listeria in Japanese monkeys varied from 0 to 40.0% depending on the capture area. L. monocytogenes was isolated from II of these positive samples. Serovars 1/2a and 4b predominated in eight serotyped L. monocytogenes isolates.

Animals↗
PubMed2000

Reduced formation of granulomata in gamma(delta) T cell knockout BALB/c mice inoculated with Mycobacterium avium subsp. paratuberculosis.

The role of gamma(delta) T cells in the bovine immune response to Mycobacterium avium subsp. paratuberculosis (M. paratuberculosis) infection is poorly understood. Accordingly, using BALB/c mice that are innately susceptible to M. paratuberculosis, we compared wild-type and gamma(delta) T cell knockout BALB/c mice to study the protective roles of gamma(delta) T cells in M. paratuberculosis infection. Ten-week-old mice were inoculated intraperitoneally with either a low dose (4 x 10(6) colony-forming units [CFU]/mouse) or a high dose (4 x 10(9) CFU/mouse) of M. paratuberculosis strain ATCC 19698. Histopathologic and morphometric examinations showed reductions in the number and area of granulomatous lesions in the liver of the knockout mice at 18 weeks after inoculation with either the low or the high dose of the mycobacteria. Furthermore, at 18 weeks after inoculation, the bacterial load in the spleens of the knockout mice inoculated with the high dose was significantly lower than that of wild-type mice. No differences were found in bacterial load between the knockout and the wild-type mice in the low-dose groups. In contrast, in the livers of wild-type mice inoculated with either the low or high mycobacterial dose, increased areas of epithelioid granulomata were observed and the granulomata became disseminated widely during the experimental period. These findings in model mice suggest that gamma(delta) T cells, rather than restricting mycobacterial growth, may play a crucial role in development of epithelioid granulomata similar to those seen consistently in bovine paratuberculosis. The results of this study may have relevance to our understanding of the pathogenesis of paratuberculosis in ruminants, in which a prominent number of gamma(delta) T cells exist in the lymphoid system.

Animals↗
PubMed2000

Analysis of ovariectomy and estrogen effects on body composition in rats by X-ray and magnetic resonance imaging techniques.

Resistance of bone to fracture--bone strength--has been shown to depend on both the amount of bone and its architectural spatial organization. In vivo magnetic resonance (MR) techniques have the capability of imaging bone tissue, including the trabecular microarchitecture and the marrow composition. We have applied in vivo and ex vivo MR methods to the tibia in an ovariectomized rat model of osteoporosis. Specifically, in vivo high-resolution three-dimensional MR imaging and localized MRS were facilitated by specialized coils and high field magnets, resulting in enhanced sensitivity of detection. As a result, in vivo and ex vivo differences in marrow composition were found between sham-ovariectomized, ovariectomized, and ovariectomized animals treated with 17-beta-estradiol. Estrogen effects were detected in vivo 7 days after surgery (3 days into treatment) as a decrease in the tibial fat signal level. The in vivo effects of ovariectomy were observed 56 days after surgery as an increase in MR image fat signal level and spectral fat/water ratio in the proximal tibia. Ex vivo measurements of tibial marrow water signal discriminated clearly between the sham and ovariectomized groups and showed increased individual variations in the treatment group. Imaging further showed that the highest fat content is observed in the epiphysis. Computed tomography confirmed ovariectomy-induced loss of bone in the proximal tibial metaphysis compared with the sham group. This loss of cancellous bone with ovariectomy is consistent with the MR observations of increases in both fat and water in the metaphysis. These data showed that MR techniques complement X-ray techniques in the bone, water, and fat compositional analysis of the appendicular skeleton in response to ovariectomy and pharmacological treatment.

Adipose Tissue↗
PubMed2000

Recurrent spontaneous pneumothoraces associated with juvenile polymyositis.

A 17-year-old man, who had received a diagnosis of juvenile polymyositis (PM) at the age of 1 year, developed recurrent spontaneous pneumothoraces and underwent surgical treatment by means of video-assisted thoracic surgery. Intraoperative observation and microscopic studies demonstrated numerous bleb-like lesions below the visceral pleura. To our knowledge, this is the first article that describes a case of spontaneous pneumothorax associated with PM. Our observation should lead to broadening of the spectrum of pleuropulmonary manifestations of PM.

Adolescent↗
PubMed2000

Successful use of argon plasma coagulation and tranilast to treat granulation tissue obstructing the airway after tracheal anastomosis.

We successfully used argon plasma coagulation (APC) and tranilast to treat granulation tissue that had formed on an end-to-end tracheal anastomosis. APC had several advantages over laser in the management of exuberant granulation tissue, and we considered tranilast to be effective in our patient. To our knowledge, this is the first description of the use of APC in the management of anastomotic granulation tissue in the trachea or bronchus.

Adult↗
PubMed2000

Large goiter and multiple rib tumors.

We report an interesting case of a 47-yr-old who had a large goiter and multiple rib tumors. The patient was initially suspected of having thyroid cancer, which had metastasized on the ribs, based on imaging studies. However, laboratory tests revealed a high level of ionized calcium and parathyroid hormone (PTH). The large goiter was diagnosed as having parathyroid tumors owing to the high level of PTH in the tissue fluid. The biopsy specimen from a rib tumor was diagnosed as containing brown tumors associated with primary hyperparathyroidism (PHP). The patient also had prolactinoma and pancreatic gastrinoma. Her daughter had both prolactinoma and PHP, and her brother and her father had PHP. Thus, the patient was diagnosed as having multiple endocrine neoplasia type 1.

Adult↗
PubMed2000

A newly recognized germline mutation of MEN1 gene identified in a patient with parathyroid adenoma and carcinoma.

We report on a patient with primary hyperparathyroidism, owing to the concurrence of parathyroid adenoma with carcinoma, who had a newly recognized germline mutation of the multiple endocrine neoplasia type 1 gene (MEN1 gene). The patient underwent total parathyroidectomy, and histological examination revealed parathyroid carcinoma and multiple adenoma of the other three glands. Genetic analysis revealed a newly recognized heterozygous germline mutation (842delC, exon 4) of the MEN1 gene. Both imaging studies and laboratory data showed no evidence of MEN1 in the patient. Four family members--three sisters and one daughter--had neither clinical features of MEN1 nor genetic evidence of the MEN1 gene. This is the first report of a germline mutation of the MEN1 gene found in a patient who exhibited the concurrence of parathyroid adenoma with carcinoma, suggesting that long-term hyperactivity of the parathyroids may result in the formation of carcinoma.

Adenoma↗
PubMed2000

Large and asymptomatic pancreatic islet cell tumor in a patient with multiple endocrine neoplasia type 1.

The major phenotypes of multiple endocrine neoplasia type 1 (MEN 1) consist of three lesions characterized by hyperparathyroidism, pituitary tumors, and endocrine pancreatic tumors. The endocrine pancreatic tumors are a significant cause of disease-related mortality in MEN 1. Although symptomatic pancreatic tumors such as insulinoma and gastrinoma should be resected, the management of asymptomatic pancreatic tumors is not established. In asymptomatic pancreatic tumors, the most important factor is the propensity for malignant transformation of the tumors. Although there are no means to foresee it, the size of the pancreatic tumors might be predictive of malignant development in MEN 1. We report here a patient with MEN 1 who had a large asymptomatic pancreatic tumor. The patient (72-yr-old man) was diagnosed with primary hyperparathyroidism and underwent a total parathyroidectomy. Genetic examination showed a germline mutation of the MEN1 gene (E45G). Abdominal magnetic resonance imaging revealed a large (>6 cm) tumor with a heterogeneous pattern in the tail of the pancreas. No metastases of the tumor were evident. Serum levels of insulin, gastrin, and glucagon were normal, and the patient had no symptoms. Operative resection was performed, and microscopic examination revealed that the tumor was an islet cell tumor stained with multiple hormones. This is a case indicating that asymptomatic pancreatic tumors associated with MEN 1 might be indolent independent of their size.

Adenoma, Islet Cell↗
PubMed2000

Different phenotypes of multiple endocrine neoplasia type 1 (MEN1) in monozygotic twins found in a Japanese MEN1 family with MEN1 gene mutation.

We report monozygotic twins who showed different MEN1 phenotypes. The proband (28 y.o., female) had both primary hyperparathyroidism (PHP) and insulinoma, and genetic analysis revealed a point mutation (569del1, exon 3) of the MEN1 gene. This mutation causes a frameshift and produces a stop codon at codon 184. Restriction digestion (HinfI) analysis confirmed the same mutation of the MEN1 gene in six of the affected members including her two sisters, the monozygotic twins, and no such mutation in two unaffected members. In two generations of this family, eight of eleven family members had PHP and four of them were found to have other MEN1-related lesions. Both of the monozygotic twins had PHP. Interestingly, one had pancreatic tumor but the other had no evidence of it. Pituitary MRI showed no pituitary lesion in either of them. This is the first Japanese case of monozygotic twins with different MEN1 phenotypes.

Adult↗
PubMed2000

A unique case of central diabetes insipidus (DI) associated with transient pituitary stalk enlargement: close observation over several years using magnetic resonance imaging (MRI) and hypophysial endocrine tests.

We had the opportunity to closely observe a unique case of central diabetes insipidus (DI), in which dramatic changes in both radiological findings and hypophysial functions were seen. A 63-year-old female developed central DI, and magnetic resonance imaging (MRI) revealed a mild thickening of the pituitary stalk and lack of hyperintense signal associated with normal neurohypophysis on T1-weighted images. About three months later, the stalk was found to be remarkably expanded like neoplasm; however, anterior pituitary functions were almost normal on that occasion, except for the absence of GH response to an insulin tolerance test. About nine months after the onset of DI, secondary hypoadrenalism and hypothyroidism, which required replacement therapy, developed transiently, but recovered about one year later. Results of hypophysial endocrine tests during this period showed that the dysfunction was predominantly suprapituitary in nature. As time passed, the stalk lesion began to shrink spontaneously and another MRI, obtained five years after the onset of DI, disclosed normal findings for the infundibulo-hypophysial system, except for lack of the hyperintense signal of the neurohypophysis. The patient has since been healthy, except for the DI, which has been controlled by treatment with vasopressin. We report here a unique case of central DI associated with transient pituitary stalk enlargement.

Adrenocorticotropic Hormone↗
PubMed2000

Environmental education praxis toward a natural conservation area.

A non-formal Environmental Education (EE) Program has been implemented in the natural conservation area (Ecological Station of Jataí, Luiz Ant nio, São Paulo State), through (EE) paradigms, which consider the objectives of education about, in and for the environment within cultural and natural perspectives. The aim of this Program is to support information and scientific knowledge to provide opportunities to the local population to be aware of environmental impacts and risks resulting from the soil use that threaten the environmental quality and the bio diversity of the Ecological Station of Jataí. The Program understands that the promotion of community empowerment could bring the sense of participation and the directives to management for decision-making for local sustainable. The model was projected on local reality, but considering the global issues of environmental paradigms. The environmental characterization (biophysical components) through a Geographical Information Systems was related to the hydrographic basin analysis. The environmental perception was utilized as a main tool to analyse population understanding of local environment, and (EE) pedagogical tools were produced to promote environmental awareness. Since the ecological dimension of (EE) was the main approach, the programme intends to assemble the cultural perspective, achieving the global view of (EE).

Brazil↗
PubMed2000

The absence of impairment of cliff avoidance reaction induced by subchronic methamphetamine treatment in inbred strains of mice.

Cliff avoidance reaction (CAR), an index of behavioral teratology in rodents, can be impaired by motor, arousal, or cognitive dysfunction. We formerly reported subchronic administration of methamphetamine (MAP) induced the CAR impairment, which might reflect MAP-induced cognitive dysfunction, in three strains of rats. In this study, the effects of subchronic MAP treatment on the behavioral sensitization in stereotypy (stereotypy sensitization) and CAR were examined in two inbred strains of male mice; C57BL/6J(C57) and DBA/2J(DBA). The animals received 4 mg/kg/day MAP intraperitoneally for 28 days. There were apparent strain differences in the development of stereotypy sensitization induced by chronic MAP; DBA mice developed stereotypy sensitization quickly, but C57 did not. Unlike rats, neither strains of mice showed the CAR impairment. These results suggest that chronic MAP (4 mg/kg) administration did not introduce any cognitive dysfunction measured by CAR in the two inbred mice, DBA and C57. The discrepancy between rats and mice is still unclear. It might relate to the species-selective effect of MAP on the CAR impairment. Further studies should to be required.

Animals↗
PubMed2000

A case report of sinonasal teratocarcinosarcoma.

A sinonasal teratocarcinosarcoma (SNTCS) is a rare and aggressive malignant neoplasm histologically characterized by the combination of one or more epithelial elements and mesenchymal components. We report a case of a 78-year-old man with SNTCS involving the nasal cavity and paranasal sinuses. He complained of epiphora and exophthalmos with weight loss. Physical and diagnostic images resulted T4N0M0. The tumor was completely and widely resected via a trans-facial approach to perform total maxillectomy with orbital exenteration. The clinical presentation, pathologic features, and clinical course are described with a review of the literature.

Aged↗
PubMed2000

Infiltration of CD8+ T cells in non-small cell lung cancer is associated with dedifferentiation of cancer cells, but not with prognosis.

CD8+ T cells infiltrating within cancer cell nests in human colorectal cancer were associated with a favorable patients' survival, suggesting the presence of anti-tumor immunity. The present study was designed to examine this concept in non-small cell lung cancer (NSCLC) by a retrospective analysis of 128 surgically resected cases. Immunohistochemical analysis showed that the number of CD8+ T cells within cancer cell nests in NSCLC was related to the histological subtype (large cell carcinoma or squamous cell carcinoma > adenocarcinoma) and the degree of dedifferentiation (undifferentiated type > differentiated type). In contrast to colorectal cancer, the number of CD8+ T cells in NSCLC had no statistically significant impact on the patients' survival. The present study demonstrated that the degree of infiltration of CD8+ T cells within cancer cell nests is dependent on the dedifferentiation of cancer cells in NSCLC, which could be one of the important aspects for the study of tumor immunity.

Adenocarcinoma↗
PubMed2000

Morphological changes in osteoblastic cells (MC3T3-E1) due to fluid shear stress: cellular damage by prolonged application of fluid shear stress.

We investigated the effect of fluid shear stress on both changes in morphology and in resting level of cytosolic concentrations of Ca2+ ([Ca2+]i) in MC3T3-E1 cells, osteoblast-like cells derived from the neonatal mouse calvaria. The cells were subjected to fluid shear stress at about 1.0 Pa. Morphological characteristics were compared between stressed and control cells by scanning electron microscopic examination, actin filament evaluation using phalloidin fluorescence and [Ca2+]i measurement using fura-2/AM. The stressed cells changed from a polygonal to a spindle shape after 1-hour exposure to fluid shear stress, whereas control cells remained polygonal, and the stressed cells exhibited an increase in the number of microvilli. The diameter in the long axis of the stressed cells was significantly larger than that of controls, and about half of the stressed cells were oriented nearly along the direction of the fluid shear stress. The arrangement of the actin filaments of the stressed cells changed to parallel, and was positioned along the long axis of the cell process. The resting level of [Ca2+]i in the stressed cells showed a peak at 1 hour after the application of the stress. A more prolonged stress period over 1 hour caused cell shrinkage, an irregularity on the cell surface, and a gradual decrease in the resting level of [Ca2+]i, suggesting that prolonged stress time may cause cellular damage.

3T3 Cells↗
PubMed2000

Auto iris pigment epithelial cell transplantation in patients with age-related macular degeneration: short-term results.

Autologous iris pigment epithelial cell transplantation was performed on patients with exudative age-related macular degeneration (AMD). Autologous IPE cell culture was performed using autologous serum after iridectomy in 7 patients with AMD. The cell suspensions (2 approximately 20 x 10(4) cells) were transplanted into the submacular lesion of individuals after removal of neovascular membranes. Subsequent ophthalmological examinations, including best corrected visual acuity and fluorescein or indocyanine green angiography, were performed. In addition, 15 patients with AMD, who underwent removal of neovascular membrane without transplantation, were evaluated as non randomized controls. Varying degrees of atrophy or defects of choriocapillaris and retinal pigment epithelium were observed in all of the patients. No cystoid macular edema or fluorescein leakage was observed after treatment, but window defects were present. No patient had decreased visual acuity. One treated patient developed mild subretinal fibrosis and an other patient developed mild preretinal fibrosis, however no difference was significant when compared with the control. In conclusion, the treatment resulted in no significant improvement in macular function, as compared with the control; however, no rejection or deterioration in visual acuity occurred up to the 13 month follow up.

Aged↗