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Biomedical subjects

M Nagatani

Publications and source records attributed to M Nagatani.

At least 19 recordsLinked to original sources
PubMed2004

Pool of dust particles over the Asian continent: balloon-borne optical particle counter and ground-based lidar measurements at Dunhuang, China.

Measurements of aerosols were made in 2001 and 2002 at Dunhuang (40 degrees 00'N, 94 degrees 30'E), China to understand the nature of atmospheric particles over the desert areas in the Asian continent. Balloon-borne measurements with an optical particle counter suggested that particle size and concentration had noticeable peaks in super micron size range not only in the boundary mixing layer but also in the free troposphere. Super-micron particle concentration largely decreased in the mid tropopause (from 5 to 10 km; above sea level, a.s.l.). Lidar measurements made during August 2002 at Dunhuang suggested the possibility that mixing of dust particles occurred from near the ground to about 6 km even under calm weather conditions, and a large depolarization ratio of particulate matter was found in the aerosol layer. The top of the aerosol layer was found at heights of nearly 6 km (a.s.l.). It is strongly suggested that nonspherical dust particles (Kosa particles) frequently diffused in the free atmosphere over the Taklamakan desert through small-scale turbulences and are possible sources of dust particles of weak Kosa events that have been identified in the free troposphere not only in spring but also in summer over Japanese archipelago. Electron microscopic experiments of the particles collected in the free troposphere confirmed that coarse and nonspherical particles observed by the mineral particle were major components of coarse mode (diameter larger than 1 microm) below about 5 km over Dunhuang, China.

Aerosols↗
PubMed2001

Spontaneous eosinophilic granulated round cell tumors in rats.

Morphologic and histochemical characteristics were noted for three spontaneous tumors with eosinophilic cytoplasmic granules that occurred in aged Fischer 344 rats. Macroscopic lesions were widely distributed in the body, mainly involving the intra-abdominal adipose tissue, pancreas, and mesenterium. These lesions were generally hard swellings with nodular and sclerosing areas. Bloody ascites was a concomitant finding. Histologically, the tumor cells were round, from 9 to 30 microm in diameter with one or two round to oval nuclei, and characterized by eosinophilic granules (0.5-2.0 microm) that stained definitely to weakly positive with the periodic acid-Schiff reaction and demonstrated no metachromasia with toluidine blue stain. Furthermore, the granules were characterized by a positive reaction with lectin histochemistry for concanavalin A (Con A), wheat germ agglutinin (WGA), phaseolus vulgaris agglutinin (PHA-E4), lens culinaris agglutinin (LCA), and recinus communis agglutinin (RCA-I) in all tumors and for ulex europaeus agglutinin (UEA-I), peanut agglutinin (PNA), and soybean agglutinin (SBA) in one tumor. Positive reactions for anti-rat mast cell protease II and CD8 were not demonstrated immunohistochemically. Abundant glycogen was noted in the large tumor cells from one rat. With electron microscopy, the cytoplasmic granules were identified as electron-dense homogenous bodies bounded by a single unit membrane. These characteristics are similar to those of granulated metrial gland cells, but further study is needed to clarify the cell of origin for these tumors.

Abdominal Neoplasms↗
PubMed2000

Kinetics of product inhibition in alcohol fermentation. Reprinted from Biotechnology and Bioengineering, Vol. X, Issue 6, Pages 845-864 (1968).

The inhibitory effect of ethanol concentration p in a medium on the specific rates of growth mu and ethanol production nu of a specific strain of baker's yeast was studied in a chemostat, where except for ethanol as the product, only the concentration of glucose S was controlled to limit the metabolic activity of the yeast. This was designed to supplement the previous findings from the batch experiment, in which ethanol was added artificially and no substrate components were limiting the metabolism of the same yeast, that mu = mu(0)e(-k(1)p) and nu = nu(0)e(-k(1)p), where k(1) and k(2) are empirical constants and subscript the 0 denotes respective values at p = 0. The effects of p on the values of mu and nu were confirmed by the Line-weaver-Burk plot to belong to noncompetitive inhibition. The formulas here for mu and nu as affected by p, if extrapolated to the case of no limiting substrates, were in good agreement in respective forms with those derived previously from the batch experiment, though the values of corresponding coefficients in these formulas were different. The differential equations for mu and nu as functions of both p and S and, in addition for the rate of glucose consumption as correlated by the yield factors either with the cell growth rate or the rate of ethanol production, were solved properly with a digital computer. A kinetic pattern calculated so far was discussed with reference to the data obtained in the batch experiment and those relevant to actual "sake" brewing.

Culture Media↗
PubMed2000

Direct effect of danazol on endometrial hyperplasia in adenomyotic women: treatment with danazol containing intrauterine device.

It is well known that danazol has a direct effect on endometriosis tissue and cell. We have been treating adenomyotic women with danazol containing intrauterine device (D-IUD) from June 1993 to August 2000 and significant decrease of dysmenorrhea and serum CA-125 levels were observed. Of fifty-nine adenomyotic women, eight women were also diagnosed by endometrial biopsy as endometrial hyperplasia and one woman was diagnosed as atypical endometrial hyperplasia. In these endometrial hyperplastic patients, endometrial tissues were obtained before insertion and at the time of removal or exchange of D-IUD and examined pathologically. In all of the 9 women, histopathological findings of endometrial hyperplasia disappeared after D-IUD treatment. In particular, in one patient, findings of atypical endometrial hyperplasia also disappeared after D-IUD treatment. She is now closely observed at our clinic using D-IUD. By these evidences, we postulate that D-IUD is one of the treatment choices of endometrial hyperplasia given exposure of the endometrium to such an extraordinary high concentration of danazol released by D-IUD and avoidance of adverse effects of oral danazol or general administration of GnRH and progesterone. In particular, in atypical endometrial hyperplasia case, its mechanisms might give great benefit to patient. However, mechanisms of direct effect of danazol on endometrial hyperplasia remain to be elucidated in the future study.

Adult↗
PubMed1998

Interfacial tension of aqueous two-phase systems containing poly(ethylene glycol) and dipotassium hydrogenphosphate.

Liquid-liquid equilibrium (LLE) compositions and interfacial tensions of the aqueous two-phase system containing poly(ethylene glycol) (PEG 4000, average Mr=3500; PEG 6000, average Mr=7500; and PEG 20000, average Mr =20000) and dipotassium hydrogenphosphate were experimentally determined by using a shaking flask method and a drop volume method at 288.15, 298.15 and 308.15 K, respectively.

Chemistry Techniques, Analytical↗
PubMed1997

Mycoplasma genitalium in the cervices of Japanese women.

BACKGROUND: Mycoplasma genitalium is considered a cause of nongonococcal urethritis in men. This organism also is a cause of genital infections in women, and has been detected in women attending sexually transmitted disease clinics in the United Kingdom and Denmark, although its prevalence is unknown in Japanese women. GOALS: To determine the prevalence of M. genitalium in the cervices of women with cervicitis or adnexitis as well as in asymptomatic pregnant women in Japan. STUDY DESIGN: Two hundred women who attended obstetric and gynecologic clinics were recruited. Sixty-four women had cervicitis, 53 had adnexitis, and 3 had both. Eighty pregnant women were asymptomatic for infection. Cervical swab specimens were examined for M. genitalium using a polymerase chain reaction-based assay. RESULTS: Five (7.8%) of 64 women with cervicitis and 3 (5.7%) of 53 women with adnexitis were positive for M. genitalium. After exclusion of Chlamydia-positive women, 5 (8.8%) of 57 women with cervicitis, and 2 (4.1%) of 49 women with adnexitis were positive for M. genitalium. In none of 80 asymptomatic pregnant women, including a Chlamydia-positive woman, was M. genitalium detected. Overall, 7 (6.6%) of 106 women with Chlamydia-negative genital infections were positive for the M. genitalium. This prevalence was significantly greater than that in asymptomatic pregnant women (P < 0.05). CONCLUSIONS: A significantly greater prevalence of M. genitalium was demonstrated in Japanese women with Chlamydia-negative cervicitis or adnexitis, compared with that in asymptomatic pregnant women. This study suggests that M. genitalium may play a pathogenic role in a portion of cases with Chlamydia-negative genital infections.

Adult↗
PubMed1996

Morphogenesis of degenerative changes predisposing dogs to rupture of the cranial cruciate ligament.

The cranial cruciate ligaments (CCL) of 13 dogs with clinical signs of CCL rupture and those of 22 clinically healthy young beagle dogs for laboratory use were examined histopathologically and immunohistopathologically. The most constant changes at an early stage of degenerating ligament tissue in affected dogs were nuclear enlargement and perinuclear halo formation of fibrocytes followed by chondroid metaplasia. These changes were also frequent in apparently healthy young beagles kept under laboratory conditions. PAS and alcian blue positive substance accumulated around activated fibrocytes and within perinuclear halos. S-100 protein was also positive in these cells preceding the morphological change of chondroid metaplasia. Increased mitotic figures and Ki-67 positive cells showed the proliferating nature of these cells at a later stage. Alteration of extracellular matrices from dense collagen fiber type to those of cartilage tissue seemed to predispose dogs to rupture of the CCL along with a degradation in collagen fiber of the primary bundles. Collagen fiber bundles with a parallel fibrillar array never formed in the CCL with degraded primary bundles, whereas activated fibrocytes constantly underwent chondroid metaplasia. The pathogenic mechanism underlying chondroid metaplasia was thought to be nonspecific and attributable to an essential property of activated fibrocytes in the mature tendon tissue.

Animals↗
PubMed1996

[A 4-week oral toxicity study of prulifloxacin (NM441) in dogs followed by a 4-week recovery test].

A repeated dose toxicity study of prulifloxacin, a new antibacterial agent, was conducted in beagle dogs. Male and female dogs were given the test material orally for 4 weeks at doses of 0 (control), 30, 150 and 750 mg/kg. After discontinuation of the treatment, a 4-week recovery test was also conducted. Feces containing white material were seen in the 150 and 750 mg/kg groups. Salivation, prone, lateral or sitting position, gait disturbance, and locomotor depression were observed in the 750 mg/kg group. In this dose group, decreased body weight and food and water consumptions were also observed. There were no treatment-related effects on survival. Ophthalmoscopic and electrocardiographic examinations and urinalysis failed to show any abnormalities related to the treatment. Hematologic examination showed decreased WBC in the 750 mg/kg group. Blood chemical examination revealed increased GPT and alpha 2-globulin in the 750 mg/kg group. Pathological changes caused by the treatment were as follows. Rarefaction of matrix, cavitations and erosions in humeral and femoral articular cartilages, and inflammatory cell infiltration in synovium were seen in the 150 and 750 mg/kg groups. Focal hemorrhage in synovium was also observed in the 750 mg/kg group. In kidney, regeneration of tubular epithelium, inflammatory cell infiltration, fibrosis and crystalline substance in the tubular lumen were observed in the 750 mg/kg group. The above-mentioned changes were satisfactorily reversible except for the changes in the humeral and femoral articular cartilages and in the kidney. Plasma levels and urinary concentrations of active metabolite of the test material were increased in all dose groups with dose-related manner, whereby no sex difference was observed. No effects caused by the repeated dosing were seen in the plasma concentrations. Toxicological findings were not observed in the 30 mg/kg group. The results show that the NOAEL of prulifloxacin is 30 mg/kg for 4-week repeated dose toxicity in dogs.

Administration, Oral↗
PubMed1994

[52-week oral toxicity study of lactitol (NS-4) in rats followed by 9-week recovery test].

Twenty five male and 25 female Slc:SD rats were given orally lactitol, a hepatic encephalopathy drug, for 52 weeks at doses of 0, 0.4, 2 or 10 g/kg/day. A 9 week recovery test was conducted after the discontinuation of the drug treatment. Treatment related death, soft stool, diarrhea, decreased body weight gain and food intake and increased water consumption were observed in the 10 g/kg group. Urinalysis showed increased Ca excretion in the 2 and 10 g/kg groups. In the 10 g/kg group, there were increased Ca++ excretion and urine specific gravity and decreased K+ and Na+ excretion and urine volume. Hematologic examination showed decreased platelet count in the 10 g/kg group. Biochemical examination revealed higher A/G ratio in the 2 and 10 g/kg groups. In the 10 g/kg group, there were lowered level of total cholesterol, triglyceride, phospholipid, Na+, Cl- and total protein. Distention of the cecum with increased organ weight was seen pathologically in the 2 and 10 g/kg groups. In the 10 g/kg group, cecal mucosa was hyperplasic. The adrenal gland was hypertrophic in the zona glomerulosa in the 2 and 10 g/kg groups. In the 10 g/kg group, the adrenal weight was increased. Dilatation of renal tubules was also found in the 10 g/kg group. The above mentioned changes were satisfactorily reversible except for the increased cecum weight in the 10 g/kg group. Based on the results obtained, the NOAEL of this study was suggested to be 0.4 g/kg/day.

Administration, Oral↗
PubMed1990

Glycogen accumulation in the renal tubular cells of spontaneously occurring diabetic WBN/Kob rats.

Cytoplasmic and nuclear accumulation of glycogen granules in the kidney cells of 72 male WBN/Kob rats with a long-term diabetic condition was studied histologically and by electron microscopy. The incidence and degree of the accumulation showed good correlation with the blood glucose concentration. In the kidneys, there was evidence of two types of lesion, cytoplasmic glycogen accumulation in the distal convoluted tubules and nuclear accumulation in the ascending thick segment of Henle's loops. Electron microscopically, the cytoplasmic glycogen accumulation was often associated with an increased number of lysosomal bodies containing lamellar bodies. Glycogen bodies, the halo of which was thought to be identical with that of nuclear bodies, were frequently observed in the nuclei containing the glycogen granules. These morphological and topographical differences between the two types of lesion were considered suggestive of different pathogenetic mechanisms for glycogen accumulation in the kidney cells.

Animals↗
PubMed1990

Superficial eosinophilic gastritis in laboratory beagle dogs attributable probably to diet.

Stomach tissues from 222 beagle dogs, which were used for toxicological studies, were examined histopathologically. Out of 190 dogs fed the same diet, 185 had gastric lesions, whereas all of 32 dogs fed another diet were free from them. The gastric lesions were noted as an accumulation of eosinophils, infiltration of inflammatory cells including lymphocytes, plasma cells and histiocytes in the gastric lamina propria, formation of foreign body type multinucleated giant cells, focal desquamation and papillary proliferation of mucosal epithelium. The lesions were confined to the superficial layer of the antral and pyloric mucosa, and neither desmoplasia nor clinical signs were seen. Multinucleated giant cells often contained amphophilic foreign bodies of varying appearance with inconsistent reaction for periodic acid-Schiff (PAS), but no definite causal agents were detected.

Animals↗
PubMed1988

Intrathecal ACNU--a new therapeutic approach against malignant leptomeningeal tumors.

Pharmacokinetics, toxicity and therapeutic efficacy of intrathecal ACNU, 3-[4-amino-2-methyl-5-pyrimidinyl)methyl)-1-(2-chloroethyl)-1-nitroso urea, were studied in rats to determine if it is a new and effective method for the treatment of malignant leptomeningeal tumors. Pharmacokinetics of intracisternally administered ACNU was studied by macroscopical autoradiography using 14C-labeled ACNU. It was demonstrated that intracisternally administered ACNU distributed in the subarachnoid space and subpial layer of the brain in high concentration and was rapidly eliminated into the systemic circulation. The diffusional transport of ACNU into the deeper part of the brain was limited. More than 3.0 mg/kg of intracisternal ACNU induced progressive loss of the weight of body in normal rats, and 80% of the rat given 6.0 mg/kg died. Increase of capillary permeability, neuronal loss and gliosis were observed in the marginal layer of the brain facing to the subarachnoid space in the rat given more than 3.0 mg/kg of ACNU. Systemic and local toxicity was not observed in the rat given less than 1.5 mg/kg. Therapeutic effect of intrathecal ACNU against leptomeningeal tumors was evaluated in the rat with meningeal carcinomatosis induced by intracisternal inoculation of Walker 256 carcinosarcoma cells. The median survival time of the rat treated with 1.5 mg/kg of intracisternal ACNU once on day 2 or on day 5 after tumor inoculation was significantly prolonged by 173%, and 214% at maximum, respectively, as compared with that of the untreated animal. These findings suggest that intrathecal ACNU may be of value for clinical trial against leptomeningeal tumors.

Animals↗
PubMed1988

[Effect of ACNU against experimental brain tumor--immunohistochemical study using anti-BrdU monoclonal antibody].

We have studied the efficacy of intrathecal ACNU against experimental leptomeningeal tumors. In the present report, the effect of ACNU on the growth kinetics of the tumor was evaluated by the immunohistochemical technique using anti-BrdU monoclonal antibody. The experimental leptomeningeal tumor was developed by inoculation of Walker 256 carcinosarcoma cells into the cisterna magna of rats. Seven days after the inoculation of tumor cells, the animals were treated either by intravenous (15 mg/kg) or intrathecal (1.5 mg/kg) ACNU. Four, 12, 24, 48, 96 or 144 hours after treatment, the animals received intravenous BrdU (200 mg/kg). Thirty minutes thereafter, they were sacrificed and the brain was removed. L. I. was calculated by counting the immunoreactive tumor cells. L. I. of the tumor without treatment on the seventh day after inoculation was over 40%. L. I. began to decrease 24 hours after intravenous ACNU, and remained 11% up to 96 hours. On the other hand, L. I. already decreased to 20% 4 hours after intrathecal ACNU and remained to be low (17%) up to 48 hours. However, L. I. increased to 38% at 96 hours. Thus, the effect on the growth kinetics of the tumor differs between intravenous and intrathecal ACNU. These results are considered to be useful informations for determining the optimal dosage of the antineoplastic agent against the brain tumor and developing the effective combination chemotherapy.

Animals↗
PubMed1987

Distribution of radiolabeled 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitros ourea hydrochloride in rat brain tumor: intraarterial versus intravenous administration.

To assess the rationale of intraarterial (i.a.) 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea chemotherapy, distribution of 14C-labeled 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)- 3-nitrosourea in rat glioma was studied after i.a. or i.v. infusion. Immediately after infusion, the tumor located in the hemisphere of intracarotid infusion received 4.6-fold higher radioactivity than the tumor located contralaterally to intracarotid infusion and 2.8-fold higher radioactivity than i.v. infusion. The difference was kept up to 30 min after i.a. infusion. Autoradiographic observation indicated rather uniform distribution of the tracer in the central portion of i.a. infusion. However, in the periphery of i.a. infusion, distribution of the tracer was nonhomogenous. The results indicate that i.a. 1-(4-amino-2-methyl-5-pyrimidinyl)methyl-3-(2-chloroethyl)-3-nitrosourea chemotherapy is useful when the tumor has high blood flow and is located in the center of an infused area.

Animals↗
PubMed1987

Relationship between cellular morphology and immunocytological findings of spontaneous pituitary tumours in the aged rat.

A total of 339 spontaneous pituitary tumours from 284 aged rats were studied by light microscopy. Based on the cellular morphology in preparations stained by haematoxylin and eosin, tumour cells were classified into 4 types: granular; agranular small; agranular large polygonal; and agranular large slender cells. Eight tumours consisted of mixed neoplastic masses of 2 types of cells. A total of 85 cases representative for each tumour type was used for special staining and immunocytochemistry. All tumours of the granular cell type and some tumours of the agranular large polygonal cell type had granules which stained red by azocarmine and were positive for prolactin. All agranular small cell type tumours were also positive for prolactin and agranular slender cell type tumours were positive for adrenocorticotropic hormone. Only tumours of the agranular large polygonal cell type gave an indefinite or negative reaction for all the various pituitary hormones. These results indicate a relatively good correlation between the cellular morphology and the immunocytochemistry of spontaneous pituitary tumours in aged rats.

Adrenocorticotropic Hormone↗
PubMed1987

Primary myxoma in the pituitary fossa: case report.

A case of primary myxoma in the pituitary fossa is described. The tumor presented as an intrasellar and suprasellar mass and was successfully removed during a transsphenoidal operation. It was verified as a myxoma by histopathological studies, and there was no evidence that it was a metastasis. This is thought to be the first report of this tumor occurring in the pituitary fossa.

Adult↗
PubMed1987

Glioblastoma after radiotherapy for craniopharyngioma: case report.

A 6-year-old girl developed a glioblastoma in the basal ganglia and brain stem 5 years after surgical excision and local irradiation (5460 cGy) for craniopharyngioma. Clinical and histological details are presented, and the literature on radiation-induced gliomas is reviewed.

Basal Ganglia↗