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Biomedical subjects

K Katagiri

Publications and source records attributed to K Katagiri.

At least 109 records · Page 6Linked to original sources
PubMed1983

Basic techniques for DNA cloning and conditions required for streptomycetes as a host.

To develop a host-vector system in streptomycetes for DNA cloning, we examined the technical problems encountered and the conditions required for use of Streptomyces kasugaensis MB273 as the host. Basic techniques, such as plasmid DNA isolation, regeneration of mycelia from protoplasts and elimination of plasmids from cells were investigated. These techniques were found to be useful for many streptomycetes. Strain M518, a derivative of S. kasugaensis MB273, was found to have the following useful characteristics as a host. The plasmids of MB273 were easily cured by regeneration of mycelia from protoplasts. The protoplasts prepared from M518 regenerated mycelia at high frequency using an improved method and were efficiently transformed by plasmid DNA. The extra and intra cellular DNase activities were very weak, and no restriction endonuclease activity was detected. The sensitivity to various antibiotics was determined. This strain did not show any pathogenicity in mice nor suvival in the digestive organs of rats. MB273 and its derivatives died rather quickly in natural soil. M518 still forms aerial mycelial conidia. These results indicate that S. kasugaensis M518, derived from MB273, has useful characteristics as a host for DNA cloning. The techniques thus developed were found to be useful in other streptomycetes.

Animals↗
PubMed1982

Effect of acetylcholine and new cholinergic derivative on amylase output, insulin, glucagon, and somatostatin secretions from perfused isolated rat pancreas.

The effect of infused acetylcholine and (2-acetyllactoyloxyethyl)-trimethylammonium hemi-1,5-naphthalenedisulfonate (aclatonium napadisilate), a new cholinergic drug . On endocrine and exocrine secretory responses was simultaneously investigated during the perfusion of isolated rat pancreases. Acetylcholine (1.1 microM) stimulated the output of pancreatic juice and amylase, and significantly elicited the production of both insulin and glucagon. Its effect on somatostatin secretion, however, was minimal. Both pancreatic juice flow and amylase output were also significantly stimulated by aclatonium napadisilate (12 microM). These stimulatory effects of aclatonium napadisilate on the exocrine pancreas were blocked by atropine (25 microM). Aclatonium napadisilate could stimulate glucagon, but could not influence insulin and somatostatin secretion. The addition of atropine had no effect on the release of insulin, glucagon, and somatostatin. These results indicate that the effects of aclatonium napadisilate is cholinergic, and that the action is muscarinic. In addition, it can be concluded that pancreatic somatostatin secretion, as well as other hormones from islet cells, is controlled by the parasympathetic nervous system.

Acetylcholine↗
PubMed1981

Succinyl trialanine p-nitroanilide-hydrolytic enzymes in human serum. Partial purification and characterization.

The levels of two kinds of elastase-like enzymes, which are able to hydrolyze an artificial elastase substrate, suc-(Ala)3-pNA, but unable to hydrolyse a naturally occurring substrate, elastin, were found to be elevated in the sera of patients suffering from hepatobiliary disorders and other diseases accompanied by tissue damage. One of the enzymes was characterized as being sensitive to a chelating reagent, EDTA, and partially inactivated enzyme activity was recovered by the addition of calcium ion. The apparent molecular weight estimated by Sepharose 4B column chromatography showed a wide distribution from 200,000 to approximately 10,000,000, but all components were converted to a molecular weight of about 200,000 by treatment with 2% Triton X-100. The activity of this enzyme was partially reduced by the addition of anti-beta-lipoprotein antibody, showing that a part of the enzyme was affiliated with low and very low density lipoproteins in the serum. The level of the other enzyme was rarely increased in the sera of patients suffering from severe hepatic disorders. This enzyme was resistant to EDTA, and the apparent molecular weight was 150,000-200,000. It appeared not to be associated with lipid component. Both enzymes were assumed to be tissue-derived enzymes, because their activities were very low in the sera of healthy persons.

Anilides↗
PubMed1981

Effect of castration on the appearance of diabetes in NOD mouse.

To examine the influence of sex hormones on the appearance of overt diabetes in NOD mice, oophorectomy and orchiectomy were performed. Castrated males showed a high incidence of diabetes. The time course of onset was similar to that of the intact females. On the other hand, castrated females showed a intact-male pattern of onset with a low incidence. Clinical determinations demonstrated a close similarity between spontaneous and castration-induced diabetes. These data suggest that sex hormones modulate the expression of overt diabetes in NOD mouse, i. e. androgens have at least a suppressive effect.

Age Factors↗
PubMed1981

Influence of temperature of incubation on chicken embryo tracheal organ cultures and chick embryos infected with strains of avian infectious bronchitis virus.

The ciliostatic and embryo lethal effect of four strains of avian infectious bronchitis virus (IBV) were observed at two different incubation temperatures. In organ cultures, nephrosis-producing IBV strains (GN-2 and M-41) were slightly more ciliostatic and respiratory strains (Beaudette and Kita-1/Tokushima) less ciliostatic at 40.5 degrees C than at 37 degrees C. Mortality of chicken embryos infected with the GN-2, M-41 and Kita-1/Tokushima strains was greater at 40.5 degrees C than at 37 degrees C, while the reverse was true of the Beaudette strain which caused no embryo mortality at 40.5 degrees C. The Beaudette strain of IBV was the only one which could not be recovered from the kidneys of young chickens four days after infection. These results indicate that the different IBV strains may show variation in virulence at different temperatures in ovo and in organ cultures and this may be a reflection of the virulence and tropism for chickens.

Animals↗
PubMed1980

Breeding of a non-obese, diabetic strain of mice.

A female mouse spontaneously exhibiting polyuria and glucosuria accompanied by rapid weight loss waa found in one of two sublines derived from the CTS mice. Eight mating pairs were made using its offspring and selection was performed for both spontaneous diabetes and reproductive ability. After six generations of the selective breeding the diabetic (nod) and the control (non) lines were established. A marked sex difference was observed in the incidence of diabetic symptoms in the nod mouse. The cumulative incidence of the onset up to 30 weeks of age was 80% in females and less than 20% in males. The onset of diabetes was abrupt in both sexes, and spontaneous remission was not observed. However, daily administration of insulin induced an increase of body weight and a prolongation of life span. Diabetic symptoms are biochemically characterized by polyuria, polydipsia, hyperglycemia, glucosuria and hypercholesteremia. Pathological examination revealed a high frequency of lymphocyte infiltration around and/or into the Langerhans' islet. It was observed even at the prediabetic stage over five weeks of both sexes. The number and size of the islets were markedly reduced in the overt diabetic mice. Although the mechanism of the pathogenesis is not clear yet, the nod mouse may be a useful animal model for investigating the human juvenile type diabetes.

Animals↗
PubMed1980

Purification and properties of Haemophilus paragallinarum hemagglutinin.

Hemagglutinin (HA) of Haemophilus paragallinarum was purified, and its immunologic, chemical, and morphologic properties were studied. The HA was purified by gel filtration on Sepharose 6B and by subsequent ultracentrifugation of trypsinized cells after pretreatment with neuraminidase. After gel filtration, the HA component (fractioned HA) gave 1 precipitin line by gel diffusion, and after inoculation in chickens, hemagglutinination-inhibition antibody to trypsin-sensitive HA antigen was found. Chickens inoculated with the fractionated HA were protected from challenge exposure with H paragallinarum. In a sample further purified by ultracentrifugation (purified HA), a single protein band was detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis; it had a molecular weight of approximately 39,000. A molecular weight of several hundred thousand to several million was observed by gel filtration. Seemingly, HA of H paragallinarum is an aggregate of more than 20 HA sub-units. The purified HA included protein and some sugars, and according to electron microscopic observation, had a filamentous structure.

Animals↗