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Biomedical subjects

M Kasai

Publications and source records attributed to M Kasai.

At least 487 records · Page 27Linked to original sources
PubMed1982

Survival of rat embryos after freezing.

The effects of cryoprotectants and freeze-thawing procedures on the survival of frozen rat morulae were examined. In the samples frozen and thawed in the presence of DMSO, ethylene glycol or glycerol, higher proportions of the embryos developed into blastocysts in culture when they were frozen slowly (50--71%) than when they were frozen rapidly (20--39%), but the thawing rates of the slowly frozen samples did not affect the viability of the embryos. When erythritol was used as a cryoprotectant, all of the embryos frozen-thawed slowly were killed but rapidly thawed embryos survived regardless of the freezing rate (36--52%). The morulae frozen slowly with ethylene glycol or glycerol and those frozen rapidly with DMSO or erythritol were transferred to recipients after thawing and full-term young were obtained with all 4 cryoprotectants.

Animals↗
PubMed1982

Studies on recovery of liver function of operated biliary atresia.

Serial liver function studies were analyzed in 42 biliary atresia patients who had undergone portoenterostomy. Values for serum bilirubin, ZTT, TTT, and gamma globulin returned to normal levels three months after operation in patients with good bile excretion. These tests remained abnormal in those with poor bile output. Alkaline phosphatase and serum transaminase values remained high during the early postoperative period, requiring a much longer duration to return to normal. The biological activity of sulfobenzyl penicillin (SBPC) in the serum and bile was determined by serial broth dilution in 15 children with biliary atresia. Eleven patients were studied 10 days to 2 weeks after an apparent successful portoenterosotomy while four others were clinically well and anicteric three to four years postoperatively. The biliary concentration of SBPC was very low despite good bile output during the early postoperative period. The SBPC levels increased three time during the remote postoperative period. The bile concentration of SBPC is lower than normal, however, and it seems that the ability of the liver to excrete this material may never reach normal levels despite apparent good clinical hepatic function.

Alanine Transaminase↗
PubMed1982

Tetrocarcins E1, E2, F and F-1, new antibiotics. Fermentation, isolation and characterization.

New components of tetrocarcins (E1, E2, F and F-1) were found in the culture broth of Micromonospora chalcea KY 11091 that was known to produce tetrocarcins A, B and C. Tetrocarcin F-1 consisted of tetronolide and nitro sugar (tetronitrose). Tetrocarcins E1 and E2 consisted of F-1 and deoxy sugar (L-digitoxose). Tetrocarcin F consisted of F-1 and two deoxy sugars (their structures were not yet determined). They all showed antibacterial activities against Gram-positive bacteria and the specific activity decreased with decrease in the numbers of deoxy sugars attached to the aglycone.

Aminoglycosides↗
PubMed1982

[Phase II study on peplomycin for esophageal cancer].

For the purpose of verifying the effectiveness of peplomycin, one of the derivatives of bleomycin, against carcinoma of the esophagus and the safety of it, the analysis of the data for total 113 cases collected from 25 institutions in Japan was made. The results are as follows. It was effective in 19 out of 74 evaluable cases of carcinoma of the esophagus (25.7%). In case of treatment with peplomycin alone, it was effective in 6 out of 39 cases (15.4%). In case of the combination treatment with peplomycin and some other therapy, it was effective in 13 out of 35 cases (37.1%). As for the side effects, the incidence of fever was the highest in both the cases of peplomycin alone and the combination treatment such as 39.6% and 37.0%, respectively. Anorexia, nausea, vomiting, respiratory symptoms and tiredness were found in relatively many cases. In the clinical laboratory tests, the vital capacity after the treatment tended to be lower than that before the treatment, but there was little change in the hematological tests, pulmonary function test and renal function test.

Adult↗
PubMed1982

[Effects of protein calorie intake on immuno- and chemotherapy].

Immuno-chemotherapeutic effect on growth of 81B mammary tumor was studied in syngeneic C3H/He mice fed diet with low (D) or normal (N) protein content. 1. 5-FU 20 mg/kg. was given intra-peritoneal daily for 3 weeks. The tumor volume ratio (T/C) was significantly reduced on day 14 in both N and D-group mice. However, all mice were dead 2 weeks after administration of 5-FU in D-group mice. 2. Immuno-potentiator OK-432 (50 KE/kg,) or Lentinan (5 mg/kg,) was given i.p. daily for 3 weeks. The 81B tumor growth was inhibited on day 14 in N-group mice. However, the tumor growth was paradoxically accelerated after administration of these agents in D-group mice. Augmentation of the natural killer cell activity was recognized in N-group mice treated with OK-432 or Lentinan, but no change was seen in D-group mice. 3. After administration of 5-FU, intra-tumoral concentration of 5-FU was higher in N-group mice than that of in D-group mice.

Animals↗
PubMed1981

Inhibition of anion permeability of sarcoplasmic reticulum vesicles by stilbene derivatives and the identification of an inhibitor-binding protein.

The permeability of sarcoplasmic reticulum vesicles to sulfate ions was inhibited by diisothiocyano-1,2-diphenylethane-2,2'-disulfonic acid (H2DIDS), which is a potent inhibitor of anion permeability in red blood cell membrane. The amount of H2DIDS bound to the vesicles was determined by using [3H]-H2DIDS. Apparent half inhibition of sulfate permeation was observed on the binding of 2.5 mumol/g protein. SDS-polyacrylamide gel electrophoresis on the vesicles treated with [3H]H2DIDS showed that about 10% of the total bound H2DIDS corresponds to a 100 000-dalton protein, but the remaining 90% to non-protein components. The content of the H2DIDS-binding protein was about 0.5 mumol/g protein. These results suggest that the H2DIDS-binding protein is different from the calcium pump protein and is possibly an anion transport system similar to band 3 in red blood cell membrane.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1981

Changes of portal vein pressure and intrahepatic blood vessels after surgery for biliary atresia.

The portal vein pressure was measured and biopsies of the liver were taken during the corrective operation in 31 patients with biliary atresia and during relaparotomy in 16 patients free from jaundice 4 mo to 9 yr after a successful corrective operation. Because the portal vein pressure was higher than 200 mmH2O in about 70% of patients during the corrective operation, portal hypertension appears to have already developed in most of the patients with biliary atresia at 2-4 mo of age. In the patients who had had frequent episodes of postoperative cholangitis, the portal vein pressure was elevated and the amount of interstitial tissue in the liver was markedly increased at reoperation compared with those at the corrective operation. These results showed that postoperative cholangitis aggravated portal hypertension and fibrosis of the liver. On the contrary, the portal vein pressure declined in patients in whom active bile drainage had persisted and cholangitis had not been complicated after operation. An early corrective operation and prevention of postoperative cholangitis are of the greatest important for prevention of development of the portal hypertension and cirrhosis of the liver in long-term survivors after surgery for biliary atresia.

Bile Ducts↗
PubMed1981

The nucleoside triphosphate (NTP)-induced superprecipitation and NTPase reaction of chicken gizzard actomyosin as a function of the NTP concentration.

The ATPase or ITPase reaction and ATP- or ITP-induced superprecipitation were studied as a function of the ATP or ITP concentration with suspensions of chicken gizzard "native" myosin B or "reconstituted" myosin B (a combination of actin, myosin, and native tropomyosin). The specific aim of the study was to answer the following questions: i) Is the superprecipitation or the ATPase reaction sensitive to calcium ions even at very low concentrations of ATP? ii) Is tropomyosin required for calcium sensitivity? iii) Does "native" myosin B from gizzard muscle behave differently from "reconstituted" myosin B? iv) Does the troponin-tropomyosin complex of rabbit skeletal muscle act as a regulatory protein for the contractile activity of acto-phosphorylated myosin? Considering the overall time course of reaction rather than single values of activity, we found that the answers to the first three questions were negative, while that to the last question was positive. These results favor the kinase-phosphatase mechanism of calcium regulation rather than the leiotonin mechanism.

Actomyosin↗
PubMed1981

Inhibition of the anion permeability of sarcoplasmic reticulum vesicles by some stilbene derivatives.

This paper concerns a study of the inhibition of sulfate permeability of sarcoplasmic reticulum vesicles by stilbene derivatives, such as 4-acetoamido-4'-isothiocyano-2,2'-stilbene-disulfonic acid (SITS), 4,4'-diisothiocyano-stilbene-2,2'-disulfonic acid (DIDS), and diisothiocyano-1,2-diphenyl-ethane-2,2'-disulfonic acid (H2DIDS). The level of sulfate permeability was measured by using a radioactive tracer. The sulfate efflux curves comprise two phases. This is explained by the existence of two types of vesicles with different permeability. The permeability of the rapidly permeated vesicles was at least 100 times higher than that of the slowly permeated vesicles. The permeability of both types of vesicles was inhibited by the above inhibitors. Apparent dissociation constants for the inhibitors of sulfate permeability were 5 mu M, 6 mu M, and 40 mu M for DIDS, H2DIDS, and SITS, respectively. The relation between sulfate permeability and the amount of the bound inhibitors was studied. To effect complete inhibition of permeation by sulfate in both vesicles, the binding of 5 mu mol of inhibitors/g protein was required. However, kinetic analysis of the sulfate efflux of the rapidly permeated vesicles suggested that the amount of the anion transport system is much smaller than 5 mu mol/g protein. Permeability for Na+ and choline was not affected by the same concentration of inhibitors. However, Ca2+ permeability was increased by the inhibitors, and at the same time Ca2+ uptake was reduced. This inhibition of Ca2+ uptake was explained by the increase of Ca2+ permeability.

Animals↗
PubMed1981

Kinetic analysis of the inhibition of anion transport in sarcoplasmic reticulum vesicles by a disulfonic stilbene derivative. Measurement of the change in chloride-diffusion potential by using a fluorescent cyanine dye.

The characterization of the anion transport system in sarcoplasmic reticulum (SR) vesicles was performed by kinetic analysis of the reversible inhibition of gluconate efflux by a disulfonic stilbene derivative; 4-acetamido-4'-isothiocyano-stilbene-2,2'-disulfonate (SITS). The gluconate efflux in SR vesicles was measured by following the change in Cl- ion-diffusion potential due to the mutual diffusion of Cl- and gluconate- using a potential probe; 3,3'-dipropylthiadicarbocyanine iodide (diS-C3-(5)). The main results are as follows. (1) Gluconate efflux was increased by intravesicular gluconate- and was decreased by both extravesicular gluconate- and extravesicular Cl-. (2) Gluconate efflux was depressed when membrane potential became inside-negative. (3) SITS reacted with the site of the anion transport system from the outside of the vesicles and one molecule of SITS inhibited each transport unit. (4) Extravesicular Cl- competed with SITS at the common site of the anion transport system. The dissociation constants for Cl- and SITS are 70 mM and 0.048 microM, respectively. (5) The inhibition of gluconate efflux by SITS was noncompetitive with both intravesicular gluconate and extravesicular gluconate. These results suggest that the anion transport system in SR vesicles can be described by a carrier-mediated transport model in which anions are transported by a mobile transport site accompanied by a net negative charge.

4-Acetamido-4'-isothiocyanatostilbene-2,2'-disulfo↗
PubMed1981

Calcium-induced calcium release from sarcoplasmic reticulum vesicles.

Passive permeability of sarcoplasmic reticulum vesicles for Ca2+ was studied by the Millipore filtration method using 45Ca. The efflux rate of Ca2+ increased in the presence of micromolar concentrations of Ca2+ in the medium when the Mg2+ concentration was low. The dependence of the Ca2+ release rate on the extravesicular Ca2+ concentration was not affected by the intravesicular Ca2+ concentration. The Ca2+ release was enhanced by caffeine, but reduced by procaine and Mg2+. These properties suggest that the Ca2+ release is a similar phenomenon to the Ca2+-induced Ca2+ release observed in skinned muscle fiber. Kinetic analysis of the efflux curves suggests that two types of vesicles exist in our preparation; about 2/3 of the vesicles release Ca2+ as described above and the remainder does not.

Animals↗
PubMed1981

Studies on the cation channel in sarcoplasmic reticulum vesicles. I. Characterization of Ca2+-dependent cation transport by using a light scattering method.

The characterization of the cation channel in sarcoplasmic reticulum (SR) vesicles was performed by measuring the choline influx. The choline influx in SR vesicles was measured by following the change in light scattering intensity using a stopped flow apparatus. From the analysis of the initial rate of choline influx, the following results were obtained. (1) The choline influx was activated by extravesicular Ca2+ with an apparent dissociation constant of 8.3 x 10(-7) M and was inhibited through two steps with inhibition constants of 2.6 x 10(-5) M and 7.4 x 10(-4) M. (2) The dependence of choline influx on the ion concentration followed the Michaelis-Menten kinetics with a half-saturation constant of 30 mM. (3) The choline influx was inhibited by lowering the pH. (4) The activation energy of choline influx was 3.5 kcal/mol. (5) The choline influx was strongly blocked by Cs+ with an inhibition constant of 10 mM. These properties of the choline transporting system in SR vesicles are similar to those of the cation channel reported by Miller (J. Membrane Biol. (1978) 40, 1--23). Lastly, the effect of extravesicular Ca2+ on the choline transport can be explained by an allosteric model.

Animals↗