PubMed Health⌕ Search

Biomedical subjects

K Ohwada

Publications and source records attributed to K Ohwada.

At least 55 records · Page 3Linked to original sources
PubMed1987

Polyethylene glycol derivative-modified cholesterol oxidase soluble and active in benzene.

Cholesterol oxidase from Nocardia sp. was modified with a synthetic copolymer of polyoxyethylene allylmethyldiether (PEG) and maleic acid anhydride (MA anhydride), poly(PEG-MA anhydride). The modified cholesterol oxidase, in which 64% of the amino groups in the protein molecule were coupled to poly(PEG-MA), was soluble in organic solvents and catalyzed the oxidation reaction of cholesterol in benzene to form 4-cholesten-3-one with the enzymic activity of 0.6 mumol/min/mg protein. Using the modified cholesterol oxidase together with polyethylene glycol-modified peroxidase, coupled reactions shown below took place in Cholesterol + O2----4-Cholesten-3-one + H2O2 H2O2 + o-Phenylenediamine----H2O + Oxidized o-Phenylenediamine transparent benzene solution, not in an emulsified system. The oxidation of cholesterol was directly determined in benzene by measuring the absorbance of oxidized o-phenylenediamine at 490 nm.

3-Hydroxysteroid Dehydrogenases↗
PubMed1987

Fibrinolysis by urokinase endowed with magnetic property.

The activated magnetic modifier was synthesized from magnetite, alpha, omega-dicarboxymethylpoly(oxyethylene) and N-hydroxysuccinimide (Biochem. Biophys. Res. Commun., 145, 908-914, 1987). Urokinase was directly coupled with the activated magnetic modifier to obtain magnetic urokinase. The magnetic urokinase dispersed in saline and exerted high fibrinolytic activity (13.8 X 10(4) IU/mg protein), and was readily recovered from saline by magnetic force of 250 Oe. By applying magnetic force, the urokinase was attracted at our will and local fibrinolysis was achieved on fibrin gel in a petri dish.

Fibrinolysis↗
PubMed1987

Analysis of diurnal difference in teratogen (Ara-C) susceptibility in mouse embryos by a progressive phase-shift method.

Our objectives were to determine whether the embryotoxic and teratogenic potential of cytosine arabinoside (Ara-C) differs depending on the time of day. Pregnant CD-1 (ICR) mice were placed in an environment where the phases of lighting and darkness were reversed by progressive phase-delay or phase-advance methods--2 h every day from day of gestation (dg) 2 to dg 7 (or 6). After it was confirmed that these progressive phase-shifting methods had no effect on embryonic growth and pregnancy outcome, 5 mg/kg body weight (bt) of Ara-C was injected intraperitoneally into these animals at 1000 or 1600 on dg 11, and the incidence of gross fetal malformations was compared with that in control dams treated similarly but under a regular lighting regimen (0600-1800). In contrast to previous reports on other teratogens, no diurnal difference was observed in fetal susceptibility to the teratogenic potential of Ara-C. The possible usefulness of the progressive phase-shifting method in the field of chronoteratology is proposed.

Animals↗
PubMed1987

Distribution of the antibody to influenza C virus in dogs and pigs in Yamagata Prefecture, Japan.

The distribution of the antibody to influenza C virus in the dogs and pigs in Yamagata prefecture, Japan was investigated by using three different serological methods: hemagglutination-inhibition (HI), radioimmunoprecipitation (RIP), and immunoblotting. The antibody against influenza C virus glycoprotein (gp88) was detected in 5 out of 112 sera collected from mongrel dogs, three by RIP test and two by any of the three methods, suggesting that the virus can cause natural infection in dogs. Significant levels of HI activity were found in 58 out of 269 sera collected from domestic pigs, but none of them showed positive reaction in the more sensitive method, RIP, which suggests that the inhibitors against the hemagglutination by influenza C virus rather than the antibody to gp88 are responsible for the observed HI activity. It appears, therefore, that at least in the Yamagata area, pigs do not play significant roles in the spread of influenza C virus in humans.

Animals↗
PubMed1986

Experimental infections of dogs with type C influenza virus.

A study was performed to determine if type C influenza infection could be established in dogs as a model for human cases. Mongrel dogs were infected with the Ann Arbor/1/50 strain of type C influenza virus and were examined for clinical symptoms, virus isolation and antibody response. After the first exposure to the virus, all infected animals developed nasal discharge and some of them also showed swelling of the eyelids, and suffusion of the eyes with tears and eye mucus, within 1 to 4 days. The animals showed an increase in hemagglutination-inhibiting (HI) serum antibody, and recovery of the agent from the nasal swabs was successful. The symptoms lasted for as long as 10 days in most infected dogs, which was comparable to our human cases reported previously (Katagiri, S., Ohizumi, A., and Homma, M. 1983. J. Infect. Dis. 48: 51-56). After the second and third virus exposures at intervals of 50 days, all animals developed the same symptoms as those described above and the rise in antibody titer was evident. The virus could be recovered from four of the six dogs 2 to 5 days after the second exposure and from one dog as late as 10 days after the third exposure. Increases in antibody titer in the IgM fraction were observed after every infection. In control dogs which were mock-infected with UV-inactivated virus, no symptoms were evident and recovery of the virus was not successful although an increase in HI serum antibody titer was seen. These results show that mongrel dogs are sensitive to type C influenza virus and that repeated infections characteristic of human influenza C can be experimentally produced in dogs.

Animals↗
PubMed1986

Changes in bronchial reactivity to acetylcholine with type C influenza virus infection in dogs.

To investigate the mechanisms involved in increasing bronchial reactivity, we made a model of airway reactivity increase in dogs after Type C influenza virus infection. Five beagle dogs were inoculated intranasally with the virus, and the time courses of changes in the hemagglutination inhibition (HI) antibody titer and the bronchial reactivity were determined. To assess bronchial reactivity the dogs were anesthetized, and dose-response curves of pulmonary resistance were obtained against increasing concentrations of acetylcholine aerosol. The dogs infected with the virus showed mild symptoms of rhinorrhea and cough. The HI antibody titer was significantly increased in all dogs, with peak values at 1 to 3 wk after infection. The bronchial reactivity to acetylcholine began to increase towards Day 3, reached a peak at 1 to 2 wk, and returned to a normal level at 4 wk. The airway reactivity to acetylcholine at 2 wk after infection was increased by 2.3 to 6.5 times the normal value in terms of the acetylcholine provocative concentration. The mean increase was significant at 1 wk (p less than 0.05), 2 wk (p less than 0.01), and 3 wk (p less than 0.05). Although both the HI antibody titer and the airway responsiveness increased together towards 1 to 2 wk, no close relationship between these factors was observed thereafter. The present dog model of airway hyperreactivity may be useful for further investigation of the mechanism governing increase in bronchial reactivity with respiratory viral infection in normal subjects as well as in patients with asthma.

Acetylcholine↗
PubMed1986

[Hygienic effect of periodical draining from auto-watering piping for laboratory animal breeding].

To prevent the bacterial contamination of the drinking water, we developed a periodical draining machine system which were composed of the electromagnetic valve and the time switch. The machine system is able to replace standing water with fresh water on optional volumes and intervals. The total bacterial numbers of standing water were counted as an indicator of the bacterial contamination. The number of total bacteria were reduced to less than 5 per ml by working the machine system on 6-hour-interval with replacing twice as much as standing water, although more than 10(3) per ml of the bacteria were found when the system was not operated. It was demonstrated that the periodical draining of the machine prevented the drinking water in auto-watering piping from bacterial contamination.

Animal Husbandry↗
PubMed1986

[Improvement of cardiac puncture in mice].

Cardiac puncture through the anterior thoracic aperture, which was originally reported by Frankeberg, was improved. The improved method involved the use of a restraining board instead of manual holding. A mouse anesthetized with ether was fixed in a dorsal position on the restraining board, and then a needle of 26G X 1/2 was inserted through the skin just in front of the anterior thoracic aperture, keeping the syringe parallel to the long axis of the animal. A blood volume of 0.6-0.9 ml could be obtained even by an inexperienced collector, and the blood collection was usually completed within 10-20 s. The potential for repeated blood collection of 0.4-0.6 ml was facilitated by use of the present method at intervals of 7 days or more.

Animals↗
PubMed1986

[A case of granulocytic sarcoma (chloroma) preceding acute leukemia].

A 2-year-old boy developed proptosis of the right eye in May 1982. He was admitted to Isawa Hospital on June 9. Physical examination revealed a well developed child with slight proptosis of the right eye and swelling of the right temple. Routine serologic and blood examination revealed no abnormality except LDH, ALP and LAP. CT scan showed high density area in the anterior part of the right temporal lobe and lateral wall of the right orbit. He underwent open-biopsy of this tumor on July 15. Eosinophilic granuloma was suspected, but definite diagnosis was not made. Second biopsy was performed at right upper gingiva on August 2. Follow-up CT scan revealed tumor invaded sphenoidal and maxillary sinus. The patient was transferred to Tohoku University Hospital on August 13. On admission myeloblasts appeared in peripheral blood, and bone marrow examination revealed acute myelo-monocytic leukemia. We discussed its difficulty of differential diagnosis in literature.

Antineoplastic Agents↗
PubMed1986

[A case of multiple myeloma showing intracranial hypertension due to large cranial mass lesions].

It is well known that the case of multiple myeloma shows punched-out lesions of the cranium without intracranial hypertension. In this paper a case of multiple myeloma is reported showing intracranial hypertension due to a large tumor that developed in the left parietal bone. There are only 13 case reports about cranial mass lesion of multiple myeloma since 1928. A 52 year-old female was admitted to Iwate Prefectural Isawa Hospital suffering from headache, nausea and vomiting. She had been already diagnosed as multiple myeloma and treated with chemotherapy using Cyclophosphamide, Melphalan and Prednisolone for 2 years. On admission, a large subcutaneous mass was presented on the left parietal region. Craniogram revealed large osteolytic lesion of the left parietal bone and 3 punched-out lesions of the frontal bone. CT scan revealed a large mass lesion in the left epidural space, diploe and subcutaneous space. Angiography showed avascular area. Brain scintigram showed diffuse hot area. Other skeletal bones showed no abnormality. Laboratory examination revealed high concentration of gamma-globulin and high erythrocyte sedimentation rate. Electrophoresis showed high value of immunoglobulin G; immunoglobulin assay was as follows: IgG-6000 mg/dl, IgA-150 mg/dl, IgM-410 mg/dl, IgE-0 mg/dl. Serum electrolytes were within normal limits. Urine didn't include Bence-Jones protein. The patient was diagnosed as multiple myeloma suffering from intracranial hypertension caused by large tumor which developed in the left parietal bone. On the operation, large tumor was existed in the epidural and subcutaneous space invading into the diploe but without infiltration into the dura mater or cerebral cortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Female↗
PubMed1983

[Rhabdomyosarcoma of the heart involving the left ventricle and left atrium].

A case of rhabdomyosarcoma of the left atrium and left ventricle demonstrated by echocardiography was reported. A 31-year-old man was admitted to our hospital for evaluation of recently developed exertional dyspnea. A holosystolic murmur and a protodiastolic sound were audible at the apex. A chest X-ray showed pulmonary congestion without cardiomegaly. The two-dimensional echocardiogram showed a dense stratified mass of echoes occupying the medial half of the left ventricular cavity, and a part of the abnormal mass of echoes was observed to move toward the left ventricular outflow tract during systole. Another small mass attached to the anterior mitral leaflet was also observed to prolapse partly into the left atrium during systole. The interatrial septum showed a thick and hard band of echo in the short-axis view. Right cardiac catheterization revealed pulmonary hypertension and the levogram of the pulmonary angiography showed left atrial and left ventricular filing defects. The repeated echocardiographic study showed the growth of the abnormal mass. The patient underwent operation, but he died of congestive heart failure thereafter. The necropsy diagnosis was rhabdomyosarcoma of the heart, involving the left atrium and left ventricle.

Adult↗
PubMed1982

Activity and growth of microbial populations in pressurized deep-sea sediment and animal gut samples.

Benthic animals and sediment samples were collected at deep-sea stations in the northwest (3,600-m depth) and southeast (4,300- and 5200-m depths) Atlantic Ocean. Utilization rates of [14C]glutamate (0.67 to 0.74 nmol) in sediment suspensions incubated at in situ temperatures and pressures (3 to 5 degrees C and 360, 430, or 520 atmospheres) were relatively slow, ranging from 0.09 to 0.39 nmol g-1 day-1, whereas rates for pressurized samples of gut suspensions varied widely, ranging from no detectable activity to a rapid rate of 986 nmol g-1 day-1. Gut flora from a holothurian specimen and a fish demonstrated rapid, barophilic substrate utilization, based on relative rates calculated for pressurized samples and samples held at 1 atm (101.325 kPa). Substrate utilization by microbial populations in several sediment samples was not inhibited by in situ pressure. Deep-sea pressures did not restrict growth, measured as doubling time, of culturable bacteria present in a northwest Atlantic sediment sample and in a gut suspension prepared from an abyssal scavenging amphipod. From the results of this study, it was concluded that microbial populations in benthic environments can demonstrate significant metabolic activity under deep-ocean conditions of temperature and pressure. Furthermore, rates of microbial activity in the guts of benthic macrofauna are potentially more rapid than in surrounding deep-sea sediments.

Acetates↗
PubMed1980

Species composition and barotolerance of gut microflora of deep-sea benthic macrofauna collected at various depths in the atlantic ocean.

The bacterial flora of marine animals collected at depths of 570 to 2,446 m was examined for population size and generic composition, and the barotolerant characteristics of selected bacterial isolates were determined. Total numbers of culturable, aerobic, heterotrophic bacteria were found to be low in animals collected at the greatest ocean depths sampled in this study. Vibrio spp. were predominant in 10 of 15 samples examined, and Photobacterium spp. and yeasts were the major components of the remainder. Pseudomonas, Achromobacter, and Flavobacterium spp. comprised minor components of the gut flora of deep-sea fish. Forty-six pure cultures isolated from samples of seven animals were tested for growth or viability after incubation for 1 week under pressures ranging from 100 to 750 atm. Strains of bacteria isolated from samples of fish intestine were more barotolerant than those from the stomach (P<0.01). When incubated at a pressure of 600 atm, viability of bacterial cultures originally isolated from fish caught at a depth of 570 m was significantly decreased in comparison with viability of cultures from animals caught at depths of 1,393 and 2,446 m (P<0.01). From results of this study, it is concluded that the gut microflora of animals that dwell in the deeper regions of the ocean are adapted to an increased hydrostatic pressure environment, that is, the gut microflora is less inhibited by elevated hydrostatic pressure with increasing depth from which the host animal was collected.

Journal Article↗
PubMedDate not supplied

Effect of arginine-enriched total parenteral nutrition on the host-tumor interaction in cancer-bearing rats.

By using a transplantable Yoshida sarcoma in a rat total parenteral nutrition model, we measured the effectiveness of an arginine-enriched amino acid solution (AI-82) in terms of leucine kinetics and nitrogen balance as indicators of host-tumor nutrition interaction compared with that of a conventional amino acid solution (Proteamin12). When tumor-bearing rats received isocaloric total parenteral nutrition solutions for 7 days, AI-82 significantly improved host nitrogen balance and significantly decreased the tumor-nitrogen trap throughout the experimental period. Leucine kinetics of whole body and tissues were also determined by a 4-hour continuous infusion of each total parenteral nutrition solution containing 14C-leucine. Significantly increased whole-body leucine oxidation (p < .01) without an increase in leucine release from normal tissues was observed in the AI-82 group. Total incorporation of 14C-leucine into whole muscle was significantly elevated (p < .05) without changes in muscle protein degradation in the AI-82 group. In the whole tumor, AI-82 tended to decrease total incorporation of 14C-leucine, but there was no difference in leucine release caused by protein breakdown between the two groups. These findings suggest that AI-82 can improve the nutritional status of the host over that of the tumor.

Animals↗