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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 1,513 records · Page 84Linked to original sources
PubMed1980

A novel ColE1::Tn3 plasmid vector that allows direct selection of hybrid clones in E. coli.

A plasmid, named pKY2289, consists of a whole ColE1 DNA molecule and a complete ampicillin transposon (Tn3). When induced, E. coli K-12 cells which carry pKY2289 promote synthesis of colicin E1, but they are not immune to colicin E1. Inserting a DNA fragment into the EcoRI or the XmaI site of this plasmid abolishes its ability to produce active colicin E1. Thus, cells carrying one of these in vitro recombinant pKY2289 plasmids are able to form normal colonies in the presence of 0.1 microgram/ml of mitomycin C and 50 microgram/ml of ampicillin, while cells carrying the parental pKY2289 form very tiny colonies under the same conditions. This allows a positive selection for an in vitro recombinant pKY2289 molecule carrying a foreign DNA insertion. The properties of cells carrying the original pKY2289 are described and its potential usefulness as a cloning vehicle is demonstrated by cloning all the EcoRI and XmaI fragments of lambda DNA.

Ampicillin↗
PubMed1980

Comparative studies on alveolar macrophages and polymorphonuclear leukocytes. I. H2O2 and O2- generation by rabbit alveolar macrophages.

The oxidative metabolism of rabbit alveolar macrophages (A-MO) was compared with that of rabbit polymorphonuclear leukocytes (PMN) with respect to H2O2 generation by intact cells or subcellular fractions. Rabbit PMN exhibited an increase in the oxygen uptake and a marked release of H2O2 upon addition of heat-killed E. coli in the presence and absence of opsonin. However, rabbit A-MO exhibited an increase in the oxygen uptake upon addition of E. coli only in the presence of anti-E. coli serum as an opsonin, whereas a very small amount of H2O2 release was observed during ingestion of the opsonized E. coli. The generation of O2- and H2O2 by a granule-rich fraction isolated from phagocytosing PMN was larger than that by a similar fraction isolated from resting PMN. However, there was no significant difference in O2- and H2O2 generation by the granule fractions between phagocytosing and resting A-MO in the presence of either NADH or NADPH. In contrast to the granule fraction of rabbit PMN, the O2- and H2O2 generating activities in the A-MO granule fraction were higher in the presence of NADH than in the presence of NADPH. The rates of NADH and NADPH oxidation by both A-MO and PMN granule fractions were measured with and without addition of Mn2+ to the assay medium. The effect of Mn2+ on the NAD(P)H oxidase was found to differ between rabbit A-MO and PMN.

Animals↗
PubMed1980

Comparative studies on alveolar macrophages and polymorphonuclear leukocytes. II. The ability of guinea pig alveolar macrophages to produce H2O2.

Guinea pig alveolar macrophages (A-M0) were studied with respect ot the phagocytic metabolism: the respiratory burst and its KCN sensitivity, the ability to generate H2O2, and myeloperoxidase (MPO) activity. Only fifty percent of the O2 uptake by A-M0 samples during phagocytosis was inhibited by the addition of 1 mK KCN. Guinea pig A-M0 released H2O2 amounting to 7.7 and 12.5 nmol/min/10(7) cells upon addition of E. coli in the absence and presence of anti-E. coli antibody, respectively. Myristic acid, an effective membrane activator, induced a marked release of H2O2 amounting to 16.1 nmol/min/10(7) cells. We observed a high MPO activity in some alveolar lavage cells which contained a large number of polymorphonuclear leukocytes (PMN), but none at all in preparations containing fewer PMN. The MPO activity detected did not seem to be due to A-M0, but to the PMN contained in the preparations.

Animals↗
PubMed1980

Comparative studies on alveolar macrophages and polymorphonuclear leukocytes. III. Difference spectra of their cellular and subcellular fractions.

The respiratory pigments of rabbit polymorphonuclear leukocytes (PMN) and alveolar macrophages (A-MO) were compared in a spectrophotometric study conducted at liquid nitrogen temperature. In the difference spectra of the KCN-treated minus the untreated states and of the reduced minus the oxidized states, the cellular and granular fractions of PMN showed sharp absorption maxima identical with the absorption bands of myeloperoxidase (MPO). Even though A-MO revealed some guaiacol-peroxidation activity, the difference spectra of cellular and subcellular A-MO fractions did not show an MPO spectrum. The enzyme catalyzing the guaiacol peroxidation by A-MO appears to be an enzyme other than the MPO found in PMN. Despite the absence of the MPO spectrum, the difference spectra of A-MO granules when measured with KCN, dithionite, and succinate showed characteristic absorption bands of mitochondrial cytochromes, in contrast to the difference spectra of PMN, which showed far smaller cytochrome absorption bands. The results obtained suggest that the phagocytic metabolism of rabbit A-MO depends on mitochondrial respiration for its energy supply.

Animals↗
PubMed1980

H2O2 release from filtration leukapheresis-procured leukocytes.

Filtration leukapheresis-procured leukocytes (FL-leukocytes), which were collected by the elution of filtration columns with vigorous tapping, released a certain amount of H2O2 even in the absence of any phagocytic stimuli. Furthermore, FL-leukocytes, eluted with either gentle or vigorous tapping, exhibited a marked release of H2O2 during phagocytosis. The myeloperoxidase (MPO) activity of FL-leukocytes was lower than that of leukocytes collected by the dextran sedimentation method (DS-leukocytes). The data suggest that the release of both H2O2 and MPO from FL-leukocytes may be related to adverse transfusion reactions and abnormal post-transfusion kinetics of FL-leukocytes due to their toxic effects on living cells.

Horseradish Peroxidase↗
PubMed1980

Preparation and antigenic properties of dehydroepiandrosterone sulfate-bovine serum albumin conjugates having a linkage through the position in ring D.

The preparation and antigenic properties of two different types of dehydroepiandrosterone sulfate-bovine serum albumin (BSA) conjugates in which the hapten is linked to the carrier protein through the C-17 or C-15 position have been described. Antibodies raised against these antigens in rabbits possessed the high affinity (Ka = 1.43 x 10(9)--2.20 x 10(9) M-1) to dehydroepiandrosterone sulfate. Antiserum elicited by immunization with the hapten-15 beta-BSA conjugate was specific to dehydroepiandrosterone sulfate, exhibiting no significant cross-reactivities for other sulfated steroids and no cross-reactions for free steroids and their glucuronides with an exception of 16 alpha-hydroxydehydroepiandrosterone 3-sulfate (16.8%).

Animals↗
PubMed1980

Effects of various pharmacologic agents on allergic inflammation of the eye. The roles of chemical mediators in ocular inflammation.

Effects of pharmacologic agents on experimental ocular inflammation induced by reverse passive Arthus reactions were investigated by a slit-lamp technique utilizing fluorescein-labeled rabbet serum albumin as an indicator. Cobra venom factor completely eliminated inflammatory responses, indicating that the complement system is a trigger for this type of ocular inflammation. Antihistamines mainly suppressed the early vascular response. Reserpine and indomethacin remarkably inhibited the increase of the permeability of the blood-aqueous barrier over the first 5 hr. Epinephrine and steroid hormone were also effective. Neither diethylcarbamazine nor isonicotinic acid showed effects on the permeability changes induced in this type of inflammation.

Animals↗
PubMed1980

The continuous and quantitative observation of permeability changes of the blood-aqueous barrier in allergic inflammation of the eye.

Permeability changes of the blood-aqueous barrier were studied in the eyes of rabbits subjected to immunologic inflammation. The changes were investigated by slit-lamp microphotometers. The leakage of fluorescein-labeled rabbit serum albumin into the anterior chamber was observed in eyes inflamed by reverse passive Arthus reactions. The permeability of the blood-aqueous barrier changed in biphasic pattern in allergic inflammations; the first phase began 5 min after the antigen challenge and lasted for 1 hr, followed by the late phase at which the dye concentration reached a peak 2 hr after the challenge and then gradually decreased.

Animals↗
PubMed1980

[Fundamental and clinical studies of sustained release cephalexin (L-Keflex) in the field of oral surgery (author's transl)].

L-Keflex is a newly manufactured cephalexin product in order to maintain effective blood level of the drug for a long period of time. The results of the fundamental and clinical studies are as follows: 1. Mean blood levels of the drug after its single oral dose of 1 g in fasting in 22 cases before operations were: 7.19 mcg/ml at 2 hours (peak), 4.35 mcg/ml at 4 hours, 4.21 mcg/ml at 6 hours, 2.47 mcg/ml at 8 hours and 1.81 mcg/ml at 12 hours, respectively. Existence of the drug in blood was observed for a long period of time. 2. The distribution into the tissues of L-Keflex was generally good. The tissue levels in 19 of 22 samples ranged from 1.30 to 18.0 mcg/g, but 3 samples did not detect the drug in the tissues. Tissue level/blood level ratios were 0.19 approximately 2.67. 3. Half of 30 cases with mild dental infections was treated with a daily dose of 1 g with clinical response of 60.0%, and the other half with 2 g was 78.6% in clinical response. The overall efficacy rate was 69.0%. 4. As a side effect of the drug, only one of 52 cases (fundamental 22 cases, clinical 30 cases) complained of edema on both eyelids. No. abnormality was observed in blood finding, hepatic and/or renal function. From the above results, it is considered that L-Keflex is an effective antibiotic product in infections in the field of oral surgery. Also, L-Keflex has an advantage in that its administration frequence (b.i.d) is less than that of regular cephalexin (q.i.d.).

Adolescent↗
PubMed1979

Repair of ultraviolet-light damaged ColE1 factor carrying Escherichia coli genes for guanine synthesis.

Hybrid ColE1 plasmids called ColE1-coslambda-qua A or ColE1-coslambda-gal can be efficiently tranduced into various E. coli K-12 cells through packaging into lambda phage particles. Using these plasmids, repair of ultraviolet-light (UV) damaged ColE1 DNAs was studied in various UV sensitive E. coli K-12 mutants. (1) The host mutations uvrA and uvrB markedly reduced host-cell reactivation of UV-irradiated ColE1-coslambda-guaA. (2) Pre-existing hybrid ColE1 plasmids had no effect on the frequency of lambda phage-mediated transduction of another differentially marked hybrid ColE1 DNAs. (3) ColE1-coslambda-guaA and ColE1-coslambda-gal DNAs could temporarily but not stably co-exist in E. coli K-12 recA cells. (4) The presence of ColE1-coslambda-gal in uvrB cells promoted the repair of super-infected UV-irradiated ColE1-coslambda-guaA about 7-fold. (5) The same ColE1-coslambda-gal plasmid in a uvrB recA double mutant did not have this promoting effect. These results indicate that the effect of resident hybrid ColE1 plasmids is manifested by the host recA+ gene function(s) and suggest that ColE1 plasmid itself provides norecA+-like functions.

Chromosome Mapping↗
PubMed1979

Developmental anomalies associated with hypospadias.

We reviewed 272 patients with hypospadias who were treated surgically to survey the complicated anomalies in these patients. Urogenital anomalies were recognized in 40 per cent of the 272 cases and extra-urogenital anomalies were noted in 9.2 per cent. Undescended testis was the most frequently seen anomaly, having been noted in 13.2 per cent of the 272 cases. The incidence of male vagina or utriculus masculinus was 11.8 per cent, prepenile scrotum 7.7 per cent and hypoplasia of the testis 6.6 per cent. Each of these 4 anomalies associated with hypospadias increased in incidence in proportion to the severity of the penile deformity. The necessity of systemic urological and hormonal examinations was emphasized, especially in cases of severe hypospadias.

Abnormalities, Multiple↗
PubMed1979

DNA sequences of the integration sites and inverted repeated structure of transposon Tn3.

The nucleotide sequence of the "inverted repeat" structure of the transposon Tn3 was determined by the DNA sequencing procedure developed by Maxam and Gilbert(1). The sequence, 38 base pairs long, is as follows: 5'-GGGGTCTGACGCTCAGTGGAACGAAAACTCACGTTAAG..(Tn3) 3'-CCCCAGACTGCGAGTCACCTTGCTTTTGAGTGCAATTC.. The integration of Tn3 is associated with a directly repeated sequence of 5 nucleotides appearing at each end of Tn3. The two directly repeated sequences so far determined are not the same. Furthermore, there is no homologous structure around the integration point of Tn3.

Base Sequence↗