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Biomedical subjects

T Kamimura

Publications and source records attributed to T Kamimura.

At least 163 records · Page 9Linked to original sources

Efficacy of human gamma-globulin preparation in experimental pseudomonas aeruginosa infections in mice and its mode of action.

The agglutinin titer of S-sulfonated human gamma-globulin (GGS, Venilon) against the formalinized cells of 20 clinical isolates of P. aeruginosa distributed as follows: 1:128 to 1:512 in 6 strains, 1:32 to 1:64 in 13 strains and 1:16 in only 1 strain. GGS given passively protected mice against P. aeruginosa infection, however, the effect of GGS differed markedly among the strains used. The difference in the effect was in correlation with the agglutinin titer of GGS against the formalinized cells but not in correlation with that against the heat-killed cells, serotypes or elastase- or protease-producing abilities of P. aeruginosa. In the experiment with representative GGS-sensitive P. aeruginosa No. 97 and GGS-resistant P. aeruginosa No. 20, P. aeruginosa No. 97 was drastically killed by polymorphonuclear leukocytes (PMNs) and macrophages in the presence of GGS, but P. aeruginosa No. 20 remained entirely unaffected. P. aeruginosa No. 97 preopsonized with GGS became more sensitive to phagocytic killing by PMNs and in vivo bactericidal activity than non-treated P. aeruginosa No. 97. Preopsonized P. aeruginosa No. 97 also markedly decreased its virulence in mice. Absorption of GGS with the formalinized P. aeruginosa No. 97 cells simultaneously reduced the agglutinating activity, protective capacity and in vivo bactericidal activity. These results indicate that the protective effect of GGS against pseudomonal infection in mice depended on an amount of specific antibody to heat-labile antigens of each P. aeruginosa used.

Agglutination Tests↗

[A case of primary malignant lymphoma in the thyroid gland arising from pre-existing Hashimoto's disease].

Primary malignant lymphoma in the thyroid gland is relatively rare. It has been reported that primary malignant lymphomas comprise 0.8-8% of all thyroid malignancies. The relation to Hashimoto's disease is controversial. A 63-year-old woman with a 9-year history of diffuse goiter visited our hospital. A clinical diagnosis of Hashimoto's disease had previously been made. After 15 months, she noted the rapid growth of the goiter and enlargement of cervical lymph nodes . A cervical lymph node was biopsied, histologic examination lymphoma (large lymphoid-diffuse type). This suggests that malignant lymphoma in the thyroid gland may arise from pre-existing Hashimoto's disease.

Biopsy↗

Inactivation of hepatitis B virus and non-A, non-B hepatitis by chloroform.

To determine whether a non-A, non-B hepatitis agent contained essential lipids, we extracted with chloroform a dilution of human plasma that contained approximately 10(4) chimpanzee infectious doses of non-A, non-B hepatitis virus and then tested for infectivity in chimpanzees. In addition, we treated a serum containing hepatitis B virus in the same way. Both of these samples were also sham extracted as controls. Known chloroform-sensitive and chloroform-resistant viruses were added directly to the hepatitis-containing serum or plasma as internal controls or to fetal calf serum as external controls and were assayed for infectivity in vitro after chloroform extraction or sham extraction. All infectivity of the diluted plasma that contained at least 10(4) chimpanzee infective doses of non-A, non-B hepatitis agent and all infectivity of the serum that contained 10(3.5) chimpanzee infective doses of hepatitis B virus were destroyed by chloroform. The chloroform-sensitive control viruses were completely inactivated, but the chloroform-resistant control viruses lost less than 0.5 log10 of infectivity. Sham-extracted non-A, non-B hepatitis agent-containing plasma was shown to maintain its infectivity in chimpanzees that had initially been inoculated with the chloroform-extracted plasma. Thus, both hepatitis type B and non-A, non-B hepatitis appear to be caused by viruses that can be inactivated by a lipid solvent.

Animals↗

Effects of methylxanthines on superprecipitation of myosin B extracted from rabbit fast skeletal muscle.

Myosin B was extracted from rabbit fast skeletal muscle. Caffeine (2-70 mM), theophylline (2-30 mM), and theobromine (2 mM) were examined for their effects on the rate and extent of myosin B superprecipitation at a low ionic strength (50 mM KCl) and a low concentration of ATP (40 microM) by the turbidimetric method. The rate of the superprecipitation was significantly (p less than 0.05 and p less than 0.01) reduced by 30-70 mM caffeine and 2-30 mM theophylline, while the extent was significantly (p less than 0.01) increased by 10-30 mM theophylline. The onset of the superprecipitation was also delayed and a clearing phase was even induced by 50-70 mM caffeine. Theobromine had no significant effect on the rate or extent of the superprecipitation at the concentration used. These results indicate that caffeine and theophylline are retardants of the myosin B superprecipitation reaction in the concentration ranges investigated.

Animals↗

Studies on the turnover rates of cytosolic and mitochondrial fumarases in rat liver.

The turnover rates of mitochondrial and cytosolic fumarase in the rat liver were determined by injecting L-[U-14C]leucine and following the decay of specific radioactivity incorporated into immunoprecipitates from the partially purified enzymes. The half-life of mitochondrial fumarase (t 1/2 = 9.7 days) was significantly different from that of the cytosolic enzyme (t 1/2 = 4.8 days). Studies on the incorporation of radioactive leucine into fumarase in the liver under steady-state conditions showed that the rate of synthesis of this enzyme in cytosol was about 2 times higher than that in the mitochondrial enzyme. The results showed that the mitochondrial fumarase turns over considerably more slowly than the cytosolic enzyme in the rat liver. These results suggest that the turnover of two fumarases with different localizations may be under different and independent control systems. In the case of the mitochondrial fumarase, the decay curve of its specific radioactivity obtained by single injection of L-[U-14C]leucine was quite unusual. No change was observed in the specific radioactivity of the mitochondrial fumarase for about 7 days after pulse labeling, then the specific radioactivity decreased exponentially with a half-life of 9.7 days.

Animals↗

Synergy of fosmidomycin (FR-31564) and other antimicrobial agents.

Fosmidomycin (FR-31564), a phosphonic acid derivative, was combined with cefazolin, cephalexin, ampicillin, carbenicillin, ticarcillin, gentamicin, and trimethoprim. Synergy between fosmidomycin and penicillins or cephalosporins was found for 37 to 52% of the Enterobacteriaceae tested. Synergy with trimethoprim was found against 55% of bacteria isolated, but only 17% of the strains showed synergy between formidomycin and gentamicin. Synergy between fosmidomycin and ticarcillin was shown for 35% of the Pseudomonas isolates. Cefazolin-, ampicillin-, and gentamicin-resistant isolates of various species were synergistically inhibited by fosmidomycin, as were ticarcillin- and gentamicin-resistant isolates. Antagonism was not encountered. This study illustrates another example of synergistic activity of compounds which attack different mechanisms in bacterial cells.

Anti-Bacterial Agents↗

[Multidisciplinary treatment of malignant melanoma of the nose and paranasal sinuses--with special reference to oral administration of enterosoluble BCG capsules].

In authors' clinic, seven patients with malignant melanoma of the nasal cavity and paranasal sinuses were treated with "per oral BCG" immunotherapy combined with other treatments for 3 years and 7 months from September 1978 to March, 1982. Eighty mg of BCG was enclosed in an enterosoluble capsule and administered to these patients orally once a week. Total doses of BCG administered were ranged from 2,240 mg to 11,860 mg. These treatments were effective for metastasis to the lung, but ineffective against the abdominal metastasis. Immunological parameters of these patients indicated good scores during the treatments. Mean survival time of four cases who died was 3 years and 3 months, and three other cases lived for 5 months, 11 months, and 2 years and 10 months, respectively. On the other hand, mean survival time of six historical control cases was 1 year and 10 months. Multidisciniplinary treatment was thought to be effective to extend their survival time. Three cases complained of arthralgia as a side effect by oral BCG administration.

Adult↗

Modification of calcium fluxes by dimethyl sulfoxide and 2-butoxyethanol in sarcoplasmic reticulum vesicles: a possible mechanism for skeletal muscle relaxation induced by dimethyl sulfoxide.

In order to investigate the mechanism of skeletal muscle relaxation induced by dimethyl sulfoxide, 2-butoxyethanol and dimethyl sulfoxide were examined for their effects on 1) Ca2+ uptake into and efflux from sarcoplasmic reticulum vesicles prepared from rabbit fast skeletal muscle and crayfish tail muscle by the murexide method, 2) ATPase activities of rabbit reticulum vesicles, 3) the isolated phrenic nerve-diaphragm preparation of the rat and 4) crayfish opener muscle preparation. Ca2+ efflux rate from rabbit reticulum vesicles was markedly decreased with increasing concentrations (5-20% v/v) of dimethyl sulfoxide without affecting the maximum Ca2+ uptake by the reticulum. 2-Butoxyethanol showed quite contrary effects. Dimethyl sulfoxide strongly inhibited the activity of basal ATPase rather than of Ca2+-dependent ATPase. 2-Butoxyethanol did not significantly inhibit the activity of basal ATPase, but markedly increased Ca2+-dependent ATPase activity. Antagonisms between dimethyl sulfoxide and caffeine were demonstrated either in contractions of crayfish opener muscles or in the Ca2+ release from crayfish sarcoplasmic reticulum vesicles. These results indicate a possibility that dimethyl sulfoxide reversibly induces skeletal muscle relaxation mainly in the sarcoplasmic reticulum by means of decreasing the rate and the amount of Ca2+ release from the reticulum.

Adenosine Triphosphatases↗

Evaluation of the antiviral effects of adenine arabinoside on chronic HBV infection.

Five male patients with HbsAg-positive liver disease were treated with ara-A at dosages ranging between 5 mg and 10 mg/kg/day for five days. Before treatment, all of them had detectable DNA polymerase activity and HbeAg in their sera. The five-day course of the drug resulted in a rapid fall in DNA polymerase activity in every patient, the effect being dose-dependent. The amount of circulating Dane particles also decreased simultaneously, or with a short time lag, with the fall of the enzyme activity. The following decrease in HBeAg concentration was observed in all patients, and it was also noteworthy that antiHBe response was found in two of the five. HBsAg titers were significantly diminished in two patients. In the present series of ara-A treatment, these effects were temporary in two patients, while, in the remaining three, they lasted for two to three months. Ara-A had no serious side effects at dosages of 10 mg/kg/day or less, and can thus be counted among the valuable therapeutic drugs against chronic HBV infection.

Adult↗

Lower vertebrate collagen. Evidence for type I-like collagen in the skin of lamprey and shark.

The soluble skin collagens of the lamprey, Entosphenus japonicus, and the great blue shark, Prionace glauca, have been isolated and characterized with respect to their chain composition. Chromatography on CM-cellulose of the denatured skin collagens and agarose gel filtration, sodium dodecyl sulfate-polyacrylamide gel electrophoresis and chemical analysis of the chromatographic fractions revealed that the two distinct subunits, alpha 1 and alpha 2, were present in a molar ratio of about 2:1. Thus, the chain composition of both lower vertebrate collagens is designated by the formula (alpha 1)2 alpha 2, similar to that of Type I collagen in higher vertebrate tissues. However, electrophoresis of the collagens in sodium dodecyl sulfate showed mostly a single type of alpha component. This seems to be due to the preferential crosslinking of alpha 1 into beta 11 dimers for the lamprey collagen and of alpha 2 into beta 12 dimers for the shark protein. These composite findings indicate that Type I-like collagen is widely distributed in the skin of vertebrates ranging from cyclostomes to mammalians.

Amino Acids↗

In vitro and in vivo antibacterial activity of FR-31564, a phosphonic acid antimicrobial agent.

The in vitro and in vivo activity of FR-31564 [sodium hydrogen 3-(N-hydroxyformamido)propylphosphate] against gram-positive and -negative aerobic and anaerobic bacteria was investigated and compared with that of fosfomycin, cephalexin, carbenicillin, and trimethoprim-sulfamethoxazole. The in vitro activity of FR-31564 was markedly enhanced when combined with glucose 6-phosphate or fructose 6-phosphate, but not when combined with ribose phosphate, adenosine monophosphate, or glycerol phosphate. In vitro activity of FR-31564 also was enhanced by human or horse blood, but not by human serum. The type of medium had a great effect on the minimal inhibitory concentration, with the lowest minimal inhibitory concentrations achieved on nutrient agar, 8- to 16-fold less than with Mueller-Hinton, heart infusion, or Trypticase soy agars. FR-31564 was more active than fosfomycin, cephalexin, carbenicillin, or trimethoprimsulfamethoxazole against Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Enterobacter cloacae, E. aerogenes, and Citrobacter. It was less active than fosfomycin against Serratia marcescens and Proteus mirabilis and did not inhibit gram-positive cocci or anaerobic species. FR-31564 inhibited a number of E. coli, K. pneumoniae, and some Pseudomonas aeruginosa strains resistant to the other agents. In the presence and absence of human blood FR-31564 showed bactericidal activity, and P. aeruginosa exposed to FR-31564 for 3 h showed a 6-h lag in regrowth. FR-31564 administered by the subcutaneous route was more active in protecting mice challenged with P. aeruginosa than was fosfomycin, carbenicillin, or cefoperazone. It was as active by the oral route in protecting mice challenged with E. coli as was fosfomycin, ampicillin, cephalexin, or trimethoprimsulfamethoxazole.

Animals↗

Methylation of 5'-5' confronting dinucleotides by vaccinia associated enzyme system.

Methylation of a series of the 5'-5' confronting dinucleotides containing various number of phosphates was examined by the use of virion enzyme system of vaccinia virus. Methylation was absolutely dependent on the number of interposed phosphate groups between 5'-5' confronting dinucleotides, showing maximum efficiency in the 3 phosphate compound corresponding to the blocked 5'-terminus (cap) of an eukaryotic mRNA. Methylation, if any, occurred only at the 7-position of guanine residue, but not at the 2' position of ribose moiety.

Dinucleoside Phosphates↗

[Effects of mecamylamine and pempidine, secondary and tertiary amines, on the spinal reflex of cats (author's transl)].

The ganglionic blocking effects of the secondary and tertiary amines, mecamylamine and pempidine, on the spinal reflex of cats of both sexes were investigated. These blocking effects were then compared with findings in the quaternary ammonium compounds such as tetraethylammonium (TEA) and decamethonium (C10). Mecamylamine (5 mg/kg) and pempidine (1 mg/kg) inhibited spinal reflex potentials such as the monosynaptic reflex (MSR), the polysynaptic reflex (PSR) and the dorsal root reflex (DRR). Maximal inhibition occurred 40 min after intravenous administration these drugs. In the case of mecamylamine, the inhibited potentials recovered gradually after reaching the maximum inhibition. However, the inhibitory effect of pempidine was prolonged, and recovery of the potentials did not occur for 6 min or longer. Although 10 mg/kg of C10 and 0.025 mg/kg of nicotine transiently inhibited the MSR and PSR, these compounds had no effect on the DDR. TEA produced prolonged inhibition of the MSR and PSR, and slightly enhanced the DRR. These results demonstrated the differences in DRR responses to secondary and tertiary amines, and quaternary ammoniums.

Animals↗