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Biomedical subjects

K Shimada

Publications and source records attributed to K Shimada.

At least 1,549 records · Page 86Linked to original sources
PubMed1979

[Treatment with NK 631 (new bleomycin analog) of oral and maxillofacial cancer (author's transl)].

Eight cases of malignant tumors of the head and neck were treated with NK 631 on a dosage schedule of 10 mg at a time 3 times weekly, by intravenous one-shot injection or intravenous drip infusion, to observe its therapeutic effects and adverse reactions. The treatment was assessed markedly effective in 3, moderately effective in 1 and ineffective in 4 of them. The treatment was also assessed moderately or markedly effective in 3 and ineffective in 2 out of squamous cell carcinoma cases. Hematologic findings, serum electrolytes and enzymologic findings were normal, but the pulmonary function examinations revealed a tendency for PaO2 to decrease slightly. In 1 case where frequent cough was observed, the cough was mitigated on withdrawal of the treatment. The adverse reactions that evolved included fever, alopecia, eruptions, nausea and vomiting, and pigmentation of the nail. To summarize these findings, the authors were impressed with NK 631 and that the agent would exert an excellent antitumor effect, compared with bleomycin, and that its effect would evolve at the early stage of its treatment. Fixed drug eruption was observed as an adverse reaction of this drug in 1 case; however, the adverse reactions of this bleomycin analog appear similar to those of its parent compound, bleomycin.

Adenocarcinoma↗
PubMed1978

Biosynthesis of the antibiotic 2,5-dihydrophenylalanine by Streptomyces arenae.

The biosynthesis of L-2,5-dihydrophenylalanine (DHPA) in Streptomyces arenae strain Tü 109 was studied in tracer experiments with [U-14C]- and [1,6-14C]shikimic acid followed by chemical degradation of the labeled product. The results indicate that shikimic acid (II) provides only the ring carbons of DHPA, that the side chain of DHPA is attached at the carbon derived from C-1 of II, and that in the transformation of II into DHPA the asymmetry of the ring of II is preserved, with C-6 of II giving rise to C-6' of DHPA. Both generally 14C-labeled chorismate and prephenate, but not L-[3-14C]serine, are incorporated into DHPA. By preparing and feeding 5,6-dihydro[4-3H]prephenate it was shown that this compound is not an intermediate in the biosynthesis of DHPA. A reaction sequence is proposed for the conversion of prephenate to DHPA, involving an allylic rearrangement, followed by 1,4 reduction of the resulting conjugated diene and a combined decarboxylation/dehydration.

Chorismic Acid↗
PubMed1978

Studies on steroids. CXXVIII. Separation and determination of bile acids by high-performance liquid chromatography.

A method is described for the simultaneous determination of major bile acids by high-performance liquid chromatography without prior hydrolysis. A mixture of bile acids is divided into the free, glyco- and tauro-conjugate groups by thin-layer chromatography. Separation of each group into cholate, ursodeoxycholate, chenodeoxycholate, deoxycholate and lithocholate is attained in two stages on a muBondapak C18 column; first, 0.3% ammonium carbonate-acetonitrile (9:4) is used as a mobile phase for the separation of the last three compounds. Subsequently cholate and ursodeoxycholate are resolved by chromatography in 0.3% ammonium carbonate-acetonitrile (11:4).

Bile Acids and Salts↗
PubMed1978

Packaging of ColE1 DNA having a lambda phage cohesive end site.

The mechanism of lambda phage-mediated transduction of hybrid colicin E1 DNAs of various lengths was studied, and factors influencing the formation of these transducing particles were investigated. The results were as follows: 1. The presence of a cohesive end site of lambda phage (coslambda) on colicin E1 DNA was essential for packaging of the DNA. 2. Packaging of colicin E1 DNAs, which carry coslambda with molecular sizes corresponding to 68% of that of lambda phage DNA, was observed in the absence of all known recombination functions of E. coli K-12 and of lambda phage. 3. Hybrid colicin E1 DNAs having coslambda with molecular sizes corresponding to 28% of that of lambda phage DNA were packaged within lambda phage particles as trimers; hybrid DNAs with coslambda of 40 and 47% of the length of lambda phage DNA were packaged as dimers; and those with molecular sizes of 68% of that of lambda phage DNA were packaged mostly as monomers. These results demonstrated that two factors are essential for the packaging of DNAs within lambda phage particles; the presence of coslambda on the DNA molecule and an appropriate size of DNA.

Bacteriocin Plasmids↗
PubMed1978

Colicinogenic mutant of ColE1 plasmid that fails to confer immunity to colicin E1.

Insertion of the ampicillin transposon (Tn3) into ColE1 DNAs causes various mutations in the plasmids. Escherichia coli K-12 cells carrying one of these mutants showed novel properties; they were sensitive to colicin E1 and were able to produce active colicin E1. The site and the orientation of Tn3 insertion in this mutant ColE1 DNA were determined by heteroduplex analysis and by enzymatic digestion with restriction endonucleases. The potential usefulness of this mutant ColE1 DNA as a cloning vehicle is discussed.

Ampicillin↗
PubMed1978

Binding sites for angiotensin II in human mononuclear leucocytes.

Angiotensin II binding sites were demonstrated in human mononuclear leucocytes by use of [125I]angiotensin II. The binding of [125I]angiotensin II to mononuclear leucocytes was rapid and reversible. The abilities of unlabeled compounds to displace [125I]angiotensin II were proportional to their abilities to displace labeled hormone in adrenal and smooth muscle membrane preparations. The Scatchard plot revealed two apparent orders of binding sites. The affinity constants were comparable with those for binding sites in other main target tissues of angiotensin II.

Adult↗
PubMed1978

Isolation and characterization of a plaque-forming lambda bacteriophage carrying a ColE1 plasmid.

A plaque-forming lambdaimm434 bacteriophage carrying the entire genome of colicinogenic factor E1 has been isolated and characterized. This phage, lambdaimm434ColE1, can lysogenize as a stable plasmid within a recombination-deficient Escherichia coli cell that lacks the normal attachment site for lambda phage. Furthermore, it has been found that lambdaimm434ColE1 phage carrying amber mutations in the O and P genes of the lambda genome, i.e., lambdaimm434OamPamColE1, behaves as a plaque-forming phage, and this finding suggests that the ColE1 factor DNA permits replication of the DNA of the plaque-forming phage.

Bacteriocin Plasmids↗
PubMed1978

Electrical activity of the oviduct of the laying hen during egg transport.

Electrical activity in the oviduct wall of the laying hen was studied. The frequency of spike discharges increased in the magnum and isthmus when the egg approached close to the recording sites. The frequency of discharge remained high in the magnum until the egg had passed, but it decreased in the isthmus during the stay of the egg. In the uterus, a relatively high activity was found immediately after oviposition and this was followed by low activity for about 5 h. Electrical activity began to increase again and reached maximum 1-2 h after the egg entered the uterus. The direction of propagation of electrical activity in the magnum was determined by using two electrodes and was towards the ovary or towards the uterus for periods of several minutes.

Action Potentials↗
PubMed1978

The effect of thyroxine on (Na+, K+)-ATPase from the heart and the kidney of rabbit.

The effect of thyroxine on membrane bound (Na+, K+)-ATPase isolated as a microsomal fraction from rabbit heart and kidney was investigated. In the heart, thyroxine administration produced an increased Ki value (a concentration of ouabain required for half maximal inhibition of (Na+, K+)-ATPase activity) without alteration of the specific activity of cardiac (Na+, K+)-ATPase, indicating that the digitalis sensitivity of cardiac (Na+, K+)-ATPase was decreased. On the contrary, a significant increase of the specific activity of renal (Na+, K+)-ATPase was observed without change in its digitalis sensitivity. These results suggest that (1) a decreased sensitivity of cardiac (Na+, K+)-ATPase to digitalis glycosides in thyrotoxic animals may contribute to the decrease in the inotropic and toxic effects of the digitalis glycosides in the hyperthyroid state, and that (2) there may be an organ difference in (Na+, K+)-ATPase.

Animals↗
PubMed1978

Effects of age, light regimes and food removal on development of daily rhythmicity in chick heart rate.

Development of daily rhythms in the chick heart rate was investigated during the post-hatching period. The measurements were made in free-moving chicks at one-hour intervals under different light conditions. Clear daily rhythms were seen 3 days after hatching under LD (12:12 hr.) whereas no daily rhythm was observed under either constant illumination or constant dark. The present study demonstrated that while heart rate increased with age during the post-hatching period, the light-time heart rate increased more rapidly than the dark-time heart rate. It was also found that the daily rhythms in heart rate were not formed after food removal even under LD. These results indicate that the light and feeding play an important role in the development of the daily rhythms in chick heart rate.

Age Factors↗