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Biomedical subjects

F Kato

Publications and source records attributed to F Kato.

At least 127 records · Page 7Linked to original sources
PubMed1982

Detection of gamma interferon in the sera of patients with Behçet's disease.

The serum levels of interferon (IFN) in 58 patients with Behçet's disease were significantly higher than those in 79 normal controls (P less than 0.0001). The average IFN titer was 51.4 +/- 9.3 IU/ml in the patients and 5.9 +/- 1.1 IU/ml in the controls. The patients were then divided into two groups according to the stage of ocular disease. Forty-six patients in the ocular convalescent stage had higher IFN levels (61.3 +/- 11.2 IU/ml) than did 12 patients in the exacerbation stage (13.2 +/- 3.0 IU/ml). Moreover, the kinetics of the IFN level in the circulation of seven patients showed a significant decrease of IFN in the exacerbation stage. IFN activity in sera from patients was destroyed by acid treatment and heating at 56 degrees C for 30 min and was not neutralized with anti-human IFN-alpha and -beta sera. In addition, it was demonstrated that vesicular stomatitis virus inhibitors detected in sera from both the patients and the controls had no effect on our IFN assay. Therefore, antiviral activity detected in sera of patients seems to be due to gamma interferon (IFN-gamma). IFN-gamma may play a significant role in the pathophysiology of Behçet's disease.

Adolescent↗
PubMed1982

Studies on spontaneous production of gamma-interferon in Behçet's disease.

Gamma-interferon (IFN-gamma) is detected at a higher level in the sera of patients with Behçet's disease than in control subjects. To investigate the cellular source of IFN-gamma, peripheral blood lymphocytes (PBL) from patients were cultured and found to produce IFN-gamma spontaneously in their fresh culture fluids. The average IFN titers in cultures of the patients' PBL were significantly higher than those of the control cultures (p less than 0.0001). The IFN activity was significantly higher in cultures of the patients in the ocular convalescent stage than in the exacerbation stage (p less than 0.0001), as was the case with serum interferon activity. Fractionation of PBL showed that only T gamma lymphocytes of the patients produced IFN-gamma spontaneously in the cultures. No IFN was produced in the culture fluids of T non-gamma cells, non-T cells or macrophages. T gamma cells and IFN-gamma may therefore play a significant role in the immunopathophysiology of Behçet's disease.

Behcet Syndrome↗
PubMed1982

Motor dysfunction in thymoma rats: comparison between fast and slow muscles.

Buffalo/Mna rats (Mna rats) with spontaneous thymoma show the motor dysfunction represented by an exacerbated fatigability of hind-limb muscles. In this study fast (extensor digitorum lomgus, EDL) and slow (soleus) muscles of these rats were examined physiologically and pharmacologically. ACI strain served as a reference. The mechanical fatigability of the EDL muscle during repetitive nerve and direct stimulation in Mna rats was greater than that in ACI rats, but electromyographical fatigabilities of both strains were quite similar. Smaller amplitude of evoked electromyograms, twitch tension (t.t.) and muscle weight (m.w.) and longer twitch relaxing time were observed in the EDL muscles of Mna rats as compared with ACI rats. On the other hand, the soleus muscles of rats of both strains showed similar t.t., and neither mechanical nor electromyographical fatigability. However, smaller t.t./m.w., greater m.w. and lower sensitivity to d-tubocurarine chloride were observed in the soleus muscles of Mna rats as compared with ACI rats. The motor dysfunction seems to result mainly from the muscle weakness and the myogenic fatigability in the fast muscle. The possibilities of some change at the site of neuro-muscular junction and a latent abnormality in the soleus muscle are also suggested.

Animals↗
PubMed1982

Motor dysfunction in spontaneous thymoma rats, Buffalo/Mna.

The muscle responsiveness of rats of Buffalo/Mna strain with spontaneous thymoma (Mna rats) was investigated in vivo electrophysiologically and pharmacologically in order to determine the principal cause of the muscle weakness and fatigability. Hindlimb muscles of these rats exhibited a lesser contractility and a greater fatigability during repetitive nerve stimulation than those of rats of another strain, ACI. Nevertheless, there was no difference in the time course of amplitude of evoked electromyograms between Mna and ACI rats. According to the test of drug sensitivity, Mna rats were much less sensitive to curare than ACI rats. Sensitivity to 4-aminopyridine was normal. In conclusion, Mna rats showed an increased fatigability and weakness of the muscle. The principal cause seems to be involved in contractile mechanisms subsequent to muscle cell membrane. The reduced sensitivity to curare suggests a possibility of some change at the site of neuro-muscular junction.

Animals↗
PubMed1982

[Clinical experience with cefoxitin used for the prevention of postoperative infections].

A total of 20 hospitalized patients underwent orthopedic surgery in the Tokyo Metropolitan Police Hospital during the period from December 1981 to March 1982. These patients were treated with cefoxitin, mainly, for the prevention of postoperative infections. The following clinical findings were obtained. 1. Out of the 20 patients, 14 were judged 'good' and 6 'fair'. 2. No side effects were reported by the patients or were evident in the clinical data. 3. These clinical results indicated that cefoxitin is a very effective antibiotic for the prevention of postoperative infections in orthopedic surgery.

Adult↗
PubMed1982

[Intrabiliary tract administration of adriamycin in bile duct cancer].

Bile duct cancer is inoperable in many cases, and coupled with advanced obstructive jaundice. Its prognosis is poor. On the systemic administration of an anti-cancer drug, the amount of the drug penetrated into tumor tissue is small and side effects of the drug appear markedly in cases complicated with jaundice. We have done experimental and clinical studies aiming at an increase of the anti-tumor effects and a decrease of side effects of the anticancer drug by administering it into the bile duct for a direct contact with tumor. In 4 cases of advanced bile duct cancer in which PTCD-procedures had been carried out, we injected Adriamycin (ADM) 20 mg via the PTCD-tube; the tube was clamped for three hours and then released. This procedure was carried out twice a week. The bile duct stenosis was reopened in all cases, and in one of them pancreaticoduodenectomy became possible. With the intrabiliary tract administration of ADM, there was little damage to the liver and bile duct system and the amounts of the drug penetrated into tumor tissue and lymph nodes were large; while blood concentration was low and side effects were decreased. This administration method was easy and gave no pain to the patients. Thus this method is considered clinically effective.

Aged↗
PubMed1981

Delayed skin reactivity of patients with herpetic stromal keratitis.

Twenty-seven patients with chronic stromal keratitis due to herpes simplex virus were tested for delayed skin reactions, to investigate the non-specific immune reactivity in vivo. Skin tests were performed with five ordinary antigens-Candida, mumps, phytohemagglutinin-P (PHA-P), purified protein derivative of tubercle bacillus (PPD), and streptokinase-streptodornase (SK-SD). The reactivity of the patients was generally decreased, as compared to the age-matched 40 healthy controls. Especially, the reactivity of the patients to PHA-P was significantly decreased (p less than 0.007). The largest mean diameters of erythema at 24 or 48 hours in Candida and PHA-P were also significantly less in the patients than in the controls (Candida, p less than 0.02; PHA-P, p less than 0.05).

Adolescent↗
PubMed1980

Influence of residual moisture and sealing atmosphere on viability of two freeze-dried viral vaccines.

This study demonstrated the complexity of the factors leading to changes in the infectivity titers of freeze-dried canine distemper and poultry infectious bronchitis viral vaccines. The change in moisture content during the storage period was an additional parameter which may influence the infectivity titer. The results emphasized the difficulty of predetermining variations in infectivity titers from the initial residual moisture. The analysis of the variations in infectivity titers during the storage of two vaccines led to the formulation of a hypothesis of the presence of two components of different thermostability. Moreover, the temporary increase in the infectivity titer of infectious bronchitis vaccine stored progressively dissociating during storage concurrent with a progressive inactivation of infectious particles.

Coronaviridae↗
PubMed1980

Reductases for aromatic aldehydes and ketones from rabbit liver. Purification and characterization.

Four aldehyde reductases, F1, F2, F3, and F4, were isolated from rabbit liver cytosol to homogeneity by various chromatographic techniques. F2 is an aldehyde reductase with a molecular weight of 32,000, which resembled aldehyde reductases of human liver and pig kidney in properties. It was inhibited in a noncompetitive way by alpha-ketoglutarate and oxaloacetate with Ki values of 4 x 10(-5) M. The other three enzymes were NADPH-dependent aromatic aldehyde-ketone reductases. F1 and F3 were monomeric enzymes with molecular weights of 38,000 and 29,000, respectively. F4 showed a molecular weight of 78,000 on gel filtration, but sodium dodecyl sulfate gel electrophoresis revealed two different subunits with molecular weights of 26,000 and 24,000. The molar ratio of NADPH : F1, F2, or F3 binding was 1 : 1, whereas that of NADPH:F4 binding was 3 : 1. The number of thiol groups in order molecule of F1, F2, F3, and F4, was 4, 4, 4, and 5, respectively. The enzyme activity of F3 was inhibited by addition of an equal mole amount of PCMB. Only F4 was inhibited by metal chelating agents. F1 also catalyzed the interconversion of 3(17)-keto and 3(17) beta-hydroxysteroids, whereas F3 catalyzed oxidoreduction of some 3 alpha-hydroxysteroids of the 5 alpha-series. These results suggest that F1 and F3 are 3(17) beta-hydroxysteroid dehydrogenase and 3 alpha-hydroxysteroid dehydrogenase, respectively. Endogenous substrates for F4 could not be identified in this work. F1 showed the lowest Km value for reduction of aldehydes and ketones among the four reductases. It has been suggested that F1 is the primary enzyme responsible for the reduction of endogeneous aldehydes and xenobiotic aldehydes and ketones in vivo.

Aldehyde Oxidoreductases↗
PubMed1979

A new freeze-dried living virus vaccine against sheep-pox.

A sheep-pox virus strain has been adapted and multiplied in primary lamb kidney cell cultures. The main characteristics of the strain have been verified in vitro after clones were isolated, and the results confirmed its identity. The safety and the potency of the strain have been investigated in sheep. The inoculation of the strain to sheep was followed by a post-vaccinal reaction materialised by a nodule at the site of inoculation and an increase of temperature by about 1 degree C. No reactions adversely affecting pregnancy have been noted. Immunisation was demonstrated by an increase in the level of neutralising serous antibodies and protection against the pathogenic virus. The immunity tended to decrease during the second year after primovaccination and a yearly booster vaccination appeared to be necessary. Primovaccination of lambs over 2 months of age produced a better immunity, especially when the lambs were born from vaccinated ewes. This strain forms the active principle of a freeze-dried vaccine containing no adjuvant of the immunity.

Animals↗
PubMed1979

Purification and properties of reductases for aromatic aldehydes and ketones from guinea pig liver.

NADPH-dependent enzymatic reduction of aromatic aldehydes and ketones observed in the cytosol of guinea pig liver was mediated by at least three distinct reductases (AR 1, AR 2, and AR 3), which were separated by DEAE-cellulose chromatography. By several procedures AR 2 and AR 3 were purified to homogeneity, but AR 1 could be purified only 30-fold because of the small amount. These enzymes were found to have similar molecular weights of 34,000 to 36,000 and similar Stokes radii of about 2.5 nm. AR 3 was identical to aldehyde reductase [EC 1.1.1.2] in substrate specificity for aromatic aldehydes and D-glucuronate and specific inhibition by barbiturates. AR 1 and AR 2 acted on aromatic ketones and cyclohexanone as well as aromatic aldehydes at optimal pHs of 5.4 and 6.0, respectively, and were immunochemically distinguished from AR 3. AR 1 was the most sensitive to sulfhydryl reagents, and AR 2 was more stable at 50 degrees C than the other enzymes. Similar heterogeneity was observed in the kidney enzymes, but other tissues had little aldehyde reductase activity and contained only AR 3. In addition, lung contained a high molecular weight aromatic ketone reductase different from the above reductases.

Aldehyde Oxidoreductases↗
PubMed1979

The effect of bleomycin on prolyl hydroxylase and DNA chain breakage: structure-activity relationship.

The activity of purified prolyl hydroxylase (proline, 2-oxoglutarate dioxygenase, EC 1.14.11.2) was enhanced about 3-fold by addition of bleomycin in the assay mixture. Various members of the bleomycin family, their derivatives and degradation products were investigated for activities against prolyl hydroxylase together with their activities of DNA chain breakage to determine relationships between the structure of bleomycin and its various actions. All the bleomycins with various terminal amine parts and desamide bleomycin stimulated the enzymatic activity but did not exhibit an effect on DNA chain breakage. The stimulatory activity of bleomycin was not decreased by hydrolysis with 0.3 N H2SO4 at 80 degrees C for 6 hours, conditions which liberates the sugar moiety, but was eliminated by hydrolysis with 6 N HCl at 105 degrees C for 24 hours. In contrast both treatments decreased the DNA chain breakage activity of bleomycin. Optical spectral studies revealed that all the bleomycins and their hydrolysates which stimulated the prolyl hydroxylase activity made complexes with ferrous ion, one of the cofactors of this enyzme.

Bleomycin↗
PubMed1978

Stimulation of prolyl hydroxylase activity by bleomycin.

The activity of purified prolyl hydroxylase (proline, 2-oxoglutarate dioxygenase, EC 1. 14. 11. 2) was enhanced 3 approximately 8-fold at a low concentration of ferrous ion (1 X 10(-5 M) by addition of bleomycin, a glycopeptide antibiotic with antineoplastic activity and a side effect of producing pulmonary fibrosis. The maximum stimulation was attained at a concentration of 15 microgram/ml bleomycin (about 1 X 10(-5) M), which was approximately equimolar with the ferrous ion, one of the cofactors of this enzyme. Addition of bleomycin to the assay mixture resulted in a change of the optimal concentration of ferrous ion from 2 X 10(-3) M to 1 X 10(-5) M. Changing the order of addition of ferrous ion, enzyme and bleomycin in assay medium before incubation at 37 degrees C, the stimulatory activity was varied. Blemycin A2Cu++(Cu++-chelated bleomycin), which scarcely complexed with Fe++, had no enhancing effects on the enzymatic activity. We discuss the possible reasons as to why the activity of prolyl hydroxylase was enhanced by addition of bleomycin in the assay mixture.

Animals↗