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Biomedical subjects

A Ito

Publications and source records attributed to A Ito.

At least 847 records · Page 47Linked to original sources

Narthecium asiaticum Maxim. Poisoning of grazing cattle: observations on spontaneous and experimental cases.

A total of 39 Holstein cattle were grazed in tracts of wild grassland on account of shortage in pasture grass. Twenty-nine cattle were affected and 26 of them died during a 21-day period. The main signs were depression, anorexia, ascites, and oliguria. There was elevated serum urea nitrogen and sugar and protein in the urine. Pathological examination revealed turbid swelling of the kidney, an increase in the amount of fluid in the body cavity, edema in the perirenal adipose tissue and hemorrhage in various visceral organs and tissues. Histologically, acute tubular necrosis in the kidney, hypoplasia of the erythroblast series in the bone marrow, atrophy and degeneration of the lymphatic tissue and focal necrosis of the liver were observed in many of the cattle. Among cows experimentally fed Narthecium asiaticum Maxim., Polygonum sachalinense Fr. Schum., and Vitis coignetiae Pulliat which were presumed to have been ingested in large amounts by grazing cattle in the field, the cows fed N. asiaticum revealed the clinical, biochemical and pathological changes similar to those noticed in naturally affected cattle. Cows fed P. sachalinense and V. coignetiae showed no distinct systemic symptoms except transient anorexia and hypothermia.

Animals↗

[Posttraumatic aneurysm-like shadow at the supraclinoid portion of the internal carotid artery--a case report].

Traumatic cerebral aneurysms occupy less than 1% in all cerebral aneurysms and the onset usually occurs two to three weeks after the head injury. The authors present a case revealing an aneurysm-like shadow at the supraclinoid portion of the internal carotid artery immediately after the head injury. A 45-year-old man was admitted in a semi-comatose state, with bleeding from the nose and the ear. He presented anisocoria, with the left pupil larger, and absence of light reflex of the pupil. Roentgenographic examinations revealed fractures of the skull, the left radius, and the pelvis. CT disclosed subarachnoid hemorrhage and intrasylvian and intracerebral hematoma, with midline shift to the right. Left carotid angiograms revealed an aneurysm-like shadow projecting medially at the supraclinoid portion of the left internal carotid artery, and an emergency operation was performed. A left fronto-temporo-parietal craniectomy was done. Incision of the dura disclosed a thin subdural hematoma and subarachnoid hemorrhage on the surface of the brain. Following removal of the intrasylvian and intracerebral hematoma and slight retraction of the left frontal lobe, a bone fracture and dural tear of the anterior cranial fossa were found. During exposure of the internal carotid artery, a heavy bleeding occurred from the supraclinoid internal carotid artery. Under control of the bleeding by temporary clipping of the internal carotid artery, the bleeding point was proved to be a longitudinal tear of the infero-medial wall of the internal carotid artery, and its length was about 5 mm. Because it was difficult to suture the tear, the internal carotid artery was doubly clipped.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm↗

Thymus dependency of induced immune responses against Hymenolepis nana (cestode) using congenitally athymic nude mice.

Anti-parasite antibody responses were compared among several strains of mice experimentally infected with the dwarf tapeworm, Hymenolepis nana. The antibody titres were highly variable among the mouse strains in addition to variation in worm fecundity and longevity. The influence of the thymus on both infection and anti-parasite antibody production (especially of IgE isotype) was studied by the use of congenitally athymic (nu/nu) nude and their phenotypically normal (nu/+) CD-1(ICR) mice infected with H. nana. All nude (nu/nu) mice harboured fully mature 70 day old adult tapeworms of the first generation derived from eggs initially given on day 0. In addition, they contained (a) younger second generation adults derived from autoinfection and present in the intestinal lumen, (b) a number of abnormally large (about 1-2 mm in diameter) balloon like, fluid filled cysticercoids in not only the intestinal tissue but also parenteral tissues such as the mesenteric lymph nodes, liver and lung, and (c) normal cysticercoids derived from challenging eggs in the intestinal tissue. Infected nude mice produced no antibodies detectable by PCA (IgE) and double diffusion (IgG) tests. In contrast, normal (nu/+) mice and nude mice reconstituted with thymocytes expelled almost all luminal adults of the primary infection by day 70 and produced antibodies to extracts of adult H. nana. Neither autoinfection nor reinfection following egg challenge occurred in any of these normal (nu/+) and reconstituted nude mice. Therefore, acquired immune responses against H. nana (as assessed by resistance not only to the tissue phase measured by the failure of tissue cysticercoid recovery from egg challenge, but also to the lumen phase assessed by the failure of autoinfection adult recovery and 'worm expulsion' of the initially established adults) are all thymus-dependent in mice. The antibody responses examined are also thymus-dependent.

Animals↗

Inhibition by 2-bromo-alpha-ergocriptine and tamoxifen of the growth of an estrogen-dependent transplantable pituitary tumor (MtT/F84) in F344 rats.

A new transplantable pituitary tumor, designated MtT/F84, was induced in estrogenized female F344 rats and has been serially passaged in 17 beta-estradiol-treated females. It grew well in rats treated with estrone, 17 beta-estradiol, or estriol but not in intact females or in rats given progesterone or testosterone. The growth of MtT/F84 in rats grafted with up to 1.6 X 10(6) tumor cells and given 17 beta-estradiol was inhibited by orally administered high dose bromocriptine (37.5 mg/kg in food) or by intraperitoneal injection of tamoxifen citrate but was not inhibited by low dose bromocriptine (3.75 mg/kg in food). The tumors grown in intact females contain high amounts of estrogen receptor, and they were greatly reduced in the tumors grown either in 17 beta-estradiol or 17 beta-estradiol-plus-tamoxifen loaded rats. However, administration of bromocriptine resulted in estrogen receptor levels significantly higher than those of tumors grown in 17 beta-estradiol. The existence of dopamine receptor was also confirmed. Growth inhibition of MtT/F84 either by high dose bromocriptine or by tamoxifen may be a direct action and may be an estrogen and dopamine receptor-mediated phenomenon.

Animals↗

[Clinical evaluation of amikacin by intravenous drip infusion for infections in the field of internal medicine].

Amikacin (AMK) by intravenous drip infusion was given to patients with infections in the field of internal medicine and the results were followings: AMK was administered to 19 patients. Diagnosis included sepsis or suspected sepsis (11 cases), pneumonia (2 cases), chronic respiratory tract infections (3 cases) and urinary tract infections (3 cases). Underlying disease included hematologic disease (13 cases), lung fibrosis (1 case), chronic respiratory insufficiency (1 case), diabetes mellitus (1 case), hepatic coma and bronchial asthma (1 case) and prostatic hypertrophy (1 case). Nineteen episodes responded to single therapy (2 cases) or combined therapy with other antibiotics (17 cases). AMK by intravenous drip infusion (dissolved in not less than 100 ml of saline or glucose) was administered at the dose of 200 mg/day to 600 mg/day divided into 2 or 3 times, over 1 hour to 2 hours. The mean duration of therapy was 10 days and the mean total dose was 4.3 g. Clinical effects: Excellent in 7 cases, good in 7 cases, fair in 3 cases and poor in 2 cases, and efficacy rate was 74%. Bacteriological effects: Disappeared in 3 cases, partly disappeared and unchanged in 3 cases, superinfection in 1 case and newly appeared in 1 case. Four strains out of 7 cases of which were detected the causative bacteria were disappeared. GM resistant bacteria (S. marcescens in 2 strains and C. diversus in 1 strain) were disappeared by the administration of AMK, also some clinical symptoms and signs were improved. No side effects and no abnormalities in laboratory findings were noted in any cases attributed to AMK. In conclusion, high efficacy rate was obtained without any side effects, intravenous drip infusion of AMK seemed to be useful for infections in patients with bleeding tendency (e.g. leukemia) or malignant disease.

Acinetobacter Infections↗

Release of P and K from yeast cells irradiated by vacuum UV below 170 nm.

Yeast cells were irradiated with monochromatic synchrotron radiation (SR) under wet conditions in the wavelength region from 160 to 185 nm at INS-SOR, Tokyo. By the particle-induced X-ray emission (PIXE) method applied to whole cells several elements were found to be released from the irradiated cells at the wavelengths shorter than 170 nm. The most drastic release occurred with phosphorus, followed potassium. Sulphur and calcium were not released over the whole wavelength region studied. It was also revealed that the release of these elements paralleled the cell inactivation. The cause of these element releases upon vaccuum-UV irradiation was inferred in relation to the dissociation of H2O molecules located in the vicinity of the cell surface region.

Particle Accelerators↗

Effect of dehydroepiandrosterone sulfate on collagenase production in rabbit uterine cervix culture.

Rabbit uterine cervical explants were found to produce a typical collagenase, latent form, in tissue culture, 4-Aminophenylmercuric acetate and trypsin were potent activators of the enzyme. The enzyme was purified simply in one step of CM-52 cellulose ion-exchange chromatography, and then further characterized. Addition of dehydroepiandrosterone sulfate (DHAS) to culture medium significantly stimulated collagenase production, but DHAS did not directly activate the enzyme. In addition, dehydroepiandrosterone and 17 beta-estradiol, the main metabolites of DHAS in vivo, depressed enzyme production. Our previous result, that increases in cytoplasmic DHAS-binding protein in rabbit uterine cervices parallel the progress of pregnancy, and these results suggest that DHAS might have direct actions toward cervical ripening.

Animals↗

Hymenolepis nana: worm recovery from congenitally athymic nude and phenotypically normal rats and mice.

When eggs or mouse-derived cysticercoids of Hymenolepis nana were inoculated into previously uninfected congenitally athymic nude (rnu/rnu) rats of an outbred Rowett strain, they failed to mature in the intestinal lumen. They also failed to mature in phenotypically normal (rnu/+) littermates, except when these hosts were treated with cortisone acetate from the beginning of the lumen phase. The Rowett rat, either thymus-deficient or not, was susceptible to tissue cysticercoids but resistant to luminal adults. It is therefore considered to be an unnatural host, at least for mouse-derived H. nana. There was little or no difference in susceptibility to initial tissue cysticercoids between these nude rats and phenotypically normal ones. The normal rats became completely resistant to reinfection with eggs and no secondary cysticercoids developed in their intestinal tissue, whereas the nude rats showed unaltered susceptibility to secondary tissue cysticercoids. Thus, acquired resistance to egg challenge, assessed by the failure of tissue cysticercoid recovery, was thymus-dependent. However, innate resistance to both a primary egg dose, assessed by the low recovery rates of tissue cysticercoids, and to a primary cysticercoid dose, assessed by the failure of luminal adult recovery, were thymus-independent. The effect of cortisone acetate to initiate maturation of H. nana appeared to be unrelated to thymus function. In contrast, all mice, either thymus-deficient or not, were highly susceptible to both phases. The number of worms recovered was more than 10 times greater than that of cysticercoids established in the rat's intestinal tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Multiple hemangioblastomas accompanied by syringomyelia in the cerebellum and the spinal cord.

The present report covers an autopsied case of multiple hemangioblastomas in the cerebellum and the spinal cord, which did not involve the retinas and other organs. An intramedullary hemangioblastoma was found at the C3-4 level of the spinal cord and similar small tumors were present at the C-7 and Th-4 levels. Multiple cysts were located from the C1-2 to the lumbar level; some of these seemed to be longitudinally continuous, like syringomyelic cavities. These findings appear only rarely in published reports of autopsied cases of hemangioblastomas in the spinal cord.

Adult↗

Stage-specific immunogens of Hymenolepis nana in mice.

Treatment with praziquantel at the beginning of the lumen phase of Hymenolepis nana in mice showed conclusively that: (i) the mouse given eggs of H. nana produces two separate immune responses against reinfection, one directed exclusively against the tissue phase of egg challenge (early response), the other against the lumen phase of cysticercoid challenge (late response); (ii) a tissue phase of egg inoculation is not necessary for initiating the late response but is necessary to provoke the early response; and (iii) H. nana expresses several stage-specific immunogens through its development in the mouse host.

Animals↗

Transport of the precursor for sulfite oxidase into intermembrane space of liver mitochondria: characterization of import and processing activities.

Sulfite oxidase, a soluble enzyme in mitochondrial intermembrane space, was synthesized as a precursor protein larger than the authentic mature enzyme when rat liver total RNA was translated in a cell-free system. When the in vitro translation products were incubated with isolated rat liver mitochondria, pre-sulfite oxidase was recovered in mitochondria and converted to the size of the mature enzyme. The in vitro-processed mature enzyme was recovered in the intermembrane space of mitochondria (Ono, H. & Ito, A. (1981) Biochem. Biophys. Res. Commun. 107, 258-264). Mature sulfite oxidase was not imported into mitochondria, and did not affect the import of pre-sulfite oxidase. When mitochondria were incubated with gel-filtered translation products, the import was dependent on ATP, and the activity restored by the addition of ATP was blocked by valinomycin and K+ ion. These results suggest that the import of pre-sulfite oxidase into mitochondrial intermembrane space requires an electrochemical potential across the inner membrane. When mitochondria were fractionated, most of the processing activity was recovered in the mitoplast, whereas the inner membrane (after being mostly inverted by sonication) exhibited only slight activity. The processing activity was strongly inhibited by some metal chelators including EDTA, GTP, and Zincon. It was not inhibited by phenyl methyl sulfonyl fluoride, aprotinin, or various microbial protease inhibitors including pepstatin, antipain, leupeptin, and chymostatin. The processing enzyme seems to be a metal protease. The processing of pre-sulfite oxidase by mitoplasts was energy-dependent.

Animals↗

Transport of the precursor for sulfite oxidase into intermembrane space of liver mitochondria: binding of the precursor to outer mitochondrial membrane.

Rat liver mitochondria were incubated with in vitro translation products programmed by liver RNA, then disrupted by sonication and subjected to sucrose density gradient centrifugation. Pre-sulfite oxidase bound preferentially to the outer mitochondrial membrane recovered with the inner membrane. This outer membrane could not be separated from the inner membrane by recentrifugation, suggesting the tight association of both membranes. The binding was not affected by pretreatment of mitochondria with proteolytic enzymes. The mature enzyme and its precursor synthesized in isolated hepatocytes have isoelectric points of 4.2 and 5.5, respectively. The molecular size of the precursor in cytosol was estimated to be about 100,000 daltons (dimer) by gel filtration.

Animals↗

Partial purification of a metalloprotease catalyzing the processing of adrenodoxin precursor in bovine adrenal cortex mitochondria.

In vitro translation of bovine adrenal cortex RNA in rabbit reticulocyte lysate cell-free system produced the precursor form of adrenodoxin having a molecular weight of approximately 22,000 daltons, which was about 10,000 daltons larger than mature adrenodoxin. The precursor of adrenodoxin was efficiently imported into adrenal cortex mitochondria in vitro. The precursor was also imported into rat liver mitochondria, suggesting the lack of tissue specificity and species specificity of the import process. The enzyme which processed the precursor of adrenodoxin to the mature form was in the matrix fraction from bovine adrenal cortex mitochondria, and the processing protease was partially purified from the matrix fraction. The apparent molecular weight of the processing protease was about 60,000 daltons as determined by Sephadex G-150 gel filtration, and its activity was optimal at pH 8.5. The processing protease was not inhibited by various bacterial protease inhibitors examined. Metal chelators (EGTA, GTP, 8-hydroxyquinoline, and Zincon) inhibited the processing, and EDTA and o-phenanthroline were more strongly inhibitory than other chelators. The processing protease was completely inactivated by incubation with 10 microM EDTA, and its activity was restored by addition of excess amounts of Mn2+, Fe2+, or Co2+. These results indicate that the maturation of the precursor of adrenodoxin is catalyzed by a soluble metalloprotease in the matrix.

Adrenal Cortex↗

The effect of sex difference on induction of intestinal metaplasia in rats.

Attempts were made to examine the sexual effects on the induction of intestinal metaplasia in rats. The number and locus of intestinal metaplasia in the gastric region induced by 2,000 rads of X-ray were greater in the male than in the female. Alkaline phosphatase activity appeared in the male only. The intestinal metaplasia induced by stomach antigen injection in the male persisted longer than in the female. Moreover, the incidence of intestinal metaplasia caused by whole body irradiation in ovariectomized rats was significantly higher than in the sham-ovariectomized ones. Therefore, it is likely that male sex hormones are promoting while female sex hormones are inhibiting the development of intestinal metaplasia.

Animals↗