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Biomedical subjects

M Tada

Publications and source records attributed to M Tada.

At least 613 records · Page 34Linked to original sources
PubMed1977

On the dye spraying method in colonofiberscopy.

Dye spraying method was applied in colonofiberscopy; 111 cases of normal colonic mucosa and 26 cases of ulcerative colitis were examined by this method. Using indigocarmine in this method, we could recognize the fine mucosal changes more easily and clearly and get better information for differential diagnosis. Furthermore, the degree of staining of the mucosa by methylene blue, one of the ultra vital staining dye, is different according to the stage of the inflammatory process of colonic mucosa itself in ulcerative colitis. Namely the stainability of the colonic mucosa is corresponding to the healing process of the disease.

Adult↗
PubMed1977

Clinical evaluation of a sonde-type small intestinal fiberscope.

Endoscopic examination using a specially designed sonde-type small intestinal fiberscope (SSIF, Olympus) was performed in 37 patients of our clinic. The improvement of the scope has enabled us to observe the greater parts of the small intestine within a short time and without hazard to the patient. Therefore, with further improvement of this instrument and the insertion technique, we will be able to inspect all parts of the small intestinal mucosa and diagnose the lesions more easily.

Adenocarcinoma↗
PubMed1977

A simplified method using commercial milk powder for hand-rearing of the Caesarean-derived infant rabbits (author's transl).

An efficient and simplified method for hand-rearing of Caesarean-derived infant rabbits under gnotobiotic condition was devised. The Caesarean-derived infant Dutch or Japanese-White rabbits and their hybrids (F1; Japanese-White female x Dutch male) were reared in sterilized vinyl-isolators by hand-feeding with two kinds of milk diets, A and B, consisted mainly ofa commercial milk powder for dogs and cats (Esbilac) supplemented with several minor components (Table 2) and administered intragastrically once a day through a Nelaton's catheter. Bacteriological examinations revealed that feces and urine were sterile for the first three days. On the third day, Escherichia coli, Staphylococcus epidermidis, Streptococcus faecalis, Bacillus subtilis, Enterococcus, and Bacteroides sp. were given with milk diet and the infant rabbits were reared until 10 to 12 weeks of age. The weaning rate at 5 weeks of age and the raising rate at 3 months of age were approximately 78% and 77%, respectively (Table 3), indicating that feeding once-a-day with a milk diet mainly composed of Esbilac is suitable for the hand-rearing of infant rabbits. There was, however, no significant difference milk diet A and B on the weaning rate.

Animal Feed↗
PubMed1976

Main binding sites of the carcinogen, 4-nitroquinoline 1-oxide in nucleic acids.

4-Hydroxyaminoquinoline 1-oxide, the reduced metabolite of 4-nitroquinoline 1-oxide, was reacted with homopolyribonucleotides through the catalysis of an activating enzyme. It bound specifically to poly(G), poly(A) and poly(X) but negligibly to poly(C), poly (U) and poly(I). Chromatographic analysis of the acid hydrolysates of carcinogen-bound polynucleotides revealed that the reaction of the carcinogen with polynucleotides yielded two guanine, one adenine and two xanthine adducts. The same kinds of guanine and adenine adducts were found in DNA or RNA isolated from Escherichia coli and mammalian cells that had been exposed to the carcinogen. Analysis of nucleic acids isolated from 4-hydroxyaminoquinoline 1-oxide-treated cells revealed that 4-hydroxy-aminoquinoline reacts in vivo preferentially with guanines, to a less, but significant, extent with adenines and not significantly with pyrimidines.

4-Nitroquinoline-1-oxide↗
PubMed1976

Effects of adenosine 3':5'-monophosphate-dependent protein kinase on sarcoplasmic reticulum isolated from cardiac and slow and fast contracting skeletal muscles.

Effects of cyclic adenosine 3':5'-monophosphate (cyclic AMP)-dependent protein kinase were studied in sarcoplasmic reticulum prepared from cardiac and slow and fast (white) skeletal muscle. Cyclic AMP-dependent protein kinase failed to catalyze phosphorylation of fast skeletal muscle microsomes as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cyclic AMP-dependent protein kinase was without effect on calcium uptake by these microsomes. Treatment of cardiac microsomes obtained from dog, cat, rabbit, and guinea pig with cyclic AMP-dependent protein kinase and ATP resulted in phosphorylation of a 22,000-dalton protein component in the amounts of 0.75, 0.25, 0.30, and 0.14 nmol of phosphorus/mg of microsomal protein, respectively. Calcium uptake by cardiac microsomes was stimulated 1.8- to 2.5-fold when microsomes were treated with cyclic AMP-dependent protein kinase. Protein kinases partially purified from bovine heart and rabbit skeletal muscle were both effective in mediating these effects on phosphorylation and calcium transport in dog cardiac sarcoplasmic reticulum. Slow skeletal muscle sarcoplasmic reticulum also contains a protein with a molecular weight of approximately 22,000 that can be phosphorylated by protein kinase. Phosphorylation of this component ranged from 0.005 to 0.016 nmol of phosphorous/mg of microsomal protein in dog biceps femoris. A statistically significant increase in calcium uptake by these membranes was produced by the protein kinase. Increases in protein kinase-catalyzed phosphorylation of a low molecular weight microsomal component and in calcium transport by sarcoplasmic reticulum of cardiac and slow skeletal muscle may be related to the relaxation-promoting effects of epinephrine seen in these types of muscle. Conversely, the absence of a relaxation-promoting effect of epinephrine in fast skeletal muscle may be associated with the lack of effect of cyclic AMP and protein kinase on calcium transport by the sarcoplasmic reticulum of this type of muscle.

Animals↗
PubMed1976

New insertion technique in colonoscopy, forming N-loop and using a stiffening cord.

New insertion technique in colonoscopy with a middle length colonscope which is easy to be handled and without guidance of fluoroscopy was reported. Forming a small N-loop at the sigmoid colon, it was easy to pass the sigmoid colon where is one of the most difficult points to pass through. Further, using a differing cord, the sigmoid colon and the transverse colon were easily straightened and no more loop was seen. With this technique, ileocecal area was observed in 26 of 30 cases (86.7%) and its average time for the insertion required only 17.4 minutes. Therefore, with this technique ,it is emphasized that we can easily observed almost all parts of the colonic mucosa and also terminal ileum without the fluoroscopic control.

Colon↗
PubMed1976

Excision in vitro of the DNA bound carcinogen, 4-nitroquinoline 1-oxide.

It has been shown that 4-hydroxyaminoquinoline 1-oxide, the proximate form of the carcinogen 4-nitroquinoline 1-oxide, binds covalently to the purine bases of DNA. Here we report that carcinogen-bound nucleotides can be excised from DNA by a 5' leads to 3' exonuclease associated with DNA polymerase I of E. coli in the forms of either mononucleotides or oligonucleotides. Beef spleen phosphodiesterase II (5' leads to 3') also split carcinogen-bound nucleotides, while a 3' leads to 5' exonuclease of DNA polymerase I and E. coli exonuclease III (3' leads to 5') could not excise the modified nucleotide.

4-Nitroquinoline-1-oxide↗
PubMed1976

Biochemical properties of cardiac sarcolemma: adenylate cyclase and (Na++K+)-activated ATPase.

Morphologically intact plasma membranes from guinea pig ventricles were obtained by exposing isolated cell segments to osmotic shock, followed by extraction of actomyosin in 1 M KC1. These preparations contained approximately 1/6 of the protein and 5-10 percent of the mitochondrial markers present in the original cell preparation. Both adenylate cyclase and (Na++K+)-activated ATPase activities were enriched 3-4 fold. The receptor for epinephrine stimulation of adenylate cyclase was retained. The "basal" ATPase activity of 5-6 mumoles of Pi/mg/hr, measured in 120 mM NaC1 or KC1, was approximately doubled in 100 mM NaC1+20 mM KC1. This increment, the (Na++K+)-activated ATPase, was abolished by 10(-5) M ouabain, the Ki for ouabain being approximately 3x10(-7) M. Adenylate cyclase, which had a basal activity of approximately 0.33 nmole of cyclic AMP produced/min/mg of protein, was significantly stimulated by both l-epinephrine and NaF. Half-maximal stimulation was seen at approximately 5x10(-6) M l-epinephrine. Increasing Ca2+ in the range between 10(-7) and 10(-3) M inhibited basal, l-epinephrine-, and NaF-stimulated adenylate cyclase activities. Basal rates of cyclic AMP production were more sensitive to Ca2+ than was l-epinephrine-stimulated adenylate cyclase activity, so that l-epinephrine stimulation was increased from approximately 60 percent in 0.5 mM ethylene glycol bis (beta-aminoethyl ether) N,N'-tetraacetic acid to approximately 150 percent in 10(-7)M Ca2+ and 400 percent in 10(-5) M Ca2+. The inhibitory effect of Ca2+ on adenylate cyclase activity may represent a negative feedback mechanism by which eelevation of intracellular Ca2+ concentration lowers cellular levels of cyclic AMP and thus reduces Ca2+ influx into the myocardium.

Adenosine Triphosphatases↗
PubMed1976

Regulation of calcium transport in cardiac sarcoplasmic reticulum by cyclic AMP-dependent protein kinase.

A manyfold increase in phosphorylation of cardiac sarcoplasmic reticulum (SR) was seen when SR was incubated in the presence of a bovine cardiac cyclic AMP-dependent protein kinase and cyclic AMP. This phosphoprotein had stability characteristics of a phosphoester in which the phosphate is incorporated largely into serine, and its formation did not required calcium ions, unlike the formation of acyl phosphoprotein intermediate of calcium-transport ATPase which is present within the same membrane. When examined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the protein kinase-catalyzed phosphorylation occurred at a 22,000-dalton component of the cardiac sarcoplasmic reticulum. This 22,000-dalton protein has been named "phospholamban" (lambda alpha mu beta alpha nu epsilon iota nu = to receive), based on its ability to receive phosphate from ATP. Phosphorylation of phospholamban by cyclic AMP-dependent protein kinase was associated with the stimulation of calcium transport by the cardiac sarcoplasmic reticulum. This stimulation was accompanied by an increase in the calcium-activated ATPase activity, indicating that the overall rate of calcium transport rather than its efficiency is enhanced by protein kinase. The 22,000-dalton phopholamban was susceptible to trypsin. Brief digestion with trypsin in the presence of 1 M sucrose prevented subsequent phosphorylation of phospholamban, while leaving the calcium pump apparently intact. Incubation of trypsin-treated sarcoplasmic reticulum with cyclic AMP-depentent protein kinase did not result in the stimulation of calcium transport. These results may suggest that phospholamban is a modulator of the calcium pump of the cardiac sarcoplasmic reticulum.

Animals↗
PubMed1975

Phosphorylation of a 22,000-dalton component of the cardiac sarcoplasmic reticulum by adenosine 3':5'-monophosphate-dependent protein kinase.

Cardiac microsomes were incubated with [gamma-32P]ATP and a cardiac adenosine 3':5'-monophosphate (cyclic AMP)-dependent protein kinase in the presence of ethylene glycol bis(bets-aminoethyl ether)-N,N'-tetraacetic acid. After solubilization in sodium dodecyl sulfate and fractionation by polyacrylamide gel electrophoresis, a single microsomal protein component of approximately 22,000 daltons was found to bind most of the 32P label. The 32P labeling of this component increased several fold when NaF was included in the incubation medium. No other component of cardiac microsomes, including sarcoplasmic reticulum ATPase protein, contained significant amounts of 32P label. This 22,000-dalton phosphoprotein formed by cyclic AMP-dependent protein kinase had stability characteristics of a phosphoester rather than an acyl phosphate. Washing of microsomes with buffered KCl did not decrease the amount of 32P labeling to the 22,000-dalton protein, suggesting that this protein is associated with the membranes of sarcoplasmic reticulum rather than being a contaminant from other soluble proteins. The 22,000-dalton protein was susceptible to trypsin. Brief digestion with trypsin in the presence of 1 M sucrose did not significantly affect microsomal calcium transport activity, but prevented both subsequent phosphorylation of the 22,000-dalton protein and stimulation of calcium uptake by cyclic AMP-dependent protein kinase, suggesting that this protein is a modulator of the calcium pump. These results are consistent with previous findings (Kirchberger, M.A., Tada, M., and Katz, A.M. (1974) J. Biol. Chem. 249, 6166-6173; Tada, M., Kirchberger, M.A., Repke, D.I., and Katz, A.M. (1974) J. Biol. Chem. 249, 6174-6180) that cyclic AMP-dependent protein kinase-catalyzed phosphorylation is associated with stimulation of calcium transport in the cardiac sarcoplasmic reticulum, and further indicate that this phosphorylation occurs at a component of low mass (22,000 daltons) of the cardiac sarcoplasmic reticulum which, while separable from the calcium transport ATPase protein (100,000 daltons) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, has the ability to regulate calcium transport by the cardiac sarcoplasmic reticulum.

Animals↗