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Biomedical subjects

S Asakawa

Publications and source records attributed to S Asakawa.

12 recordsLinked to original sources
PubMed1992

A useful cholesterol solvent for medical dissolution of gallstones.

Dissolution of cholesterol gallstones by direct instillation of an agent into the biliary tract has been considered an alternate to surgical procedures. We developed an excellent direct solubilizer by combining d-limonene and medium-chain monoglyceride. This mixture enhances the advantages of each individual solvent and minimizes the disadvantages. In vitro experiments were done to determine the viscosities and the cholesterol dissolving rates of various combinations, and in vivo experiments were conducted to study their irritation effects on tissues. The optimal combination was a 3:2 mixture of d-limonene and medium-chain monoglyceride. It could quickly dissolve cholesterol gallstones with minimal or no observable side effect.

Animals↗
PubMed1992

[Application of the limulus amebocyte lysate test to measurement of endotoxin in therapeutic human plasma protein fraction. Comparison with the rabbit pyrogen test].

We applied the limulus amebocyte lysate (LAL) test to the detection of bacterial endotoxins in therapeutic human plasma protein fraction (PPF) and compared the LAL-test with the rabbit pyrogen test. Two endotoxin-specific LAL-reagents were used for the colorimetric method and turbidimetric kinetic method. The amounts of added endotoxin to the PPF were correctly estimated by either method. The results of four independent assays for the 53 samples of PPF corresponded well with each other (correlation coefficient: 0.851-0.959, regression coefficient: 0.898-1.151). The amounts of endotoxin in the PPF estimated by the LAL-test significantly correlated with the rise of body temperature in rabbits (correlation coefficient: 0.547-0.642, and 0.911-0.934 for the endotoxin added samples). These results suggest that the LAL-test could be used as an alternative method for the rabbit pyrogen test to PPF.

Animals↗
PubMed1991

Strand-specific nucleotide composition bias in echinoderm and vertebrate mitochondrial genomes.

The gene organization of starfish mitochondrial DNA is identical with that of the sea urchin counterpart except for a reported inversion of an approximately 4.6-kb segment containing two structural genes for NADH dehydrogenase subunits 1 and 2 (ND 1 and ND 2). When the codon usage of each structural gene in starfish, sea urchin, and vertebrate mitochondrial DNAs is examined, it is striking that codons ending in T and G are preferentially used more for heavy strand-encoded genes, including starfish ND 1 and ND 2, than for light strand-encoded genes, including sea urchin ND 1 and ND 2. On the contrary, codons ending in A and C are preferentially used for the light strand-encoded genes rather than for the heavy strand-encoded ones. Moreover, G-U base pairs are more frequently found in the possible secondary structures of heavy strand-encoded tRNAs than in those of light strand-encoded tRNAs. These observations suggest the existence of a certain constraint operating on mitochondrial genomes from various animal phyla, which results in the accumulation of G and T on one strand, and A and C on the other.

Amino Acid Sequence↗
PubMed1979

Multicorrelation analyses of toxic and antigenic components of DPT and DP vaccines produced in Japan.

The combined diphtheria-pertussis-tetanus and combined diphtheria-pertussis vaccines, of which the contents of endotoxin, LPF and HSF were reported in the previous paper, have been tested for the respective potencies of pertussis, diphtheria and tetanus components. In order to obtain some information concerning possible adjuvanticities of the toxic components of pertussis cells, relationship between respective toxic activities and the potencies of the respective antigenic components were tested by applying the multiple regression analyses. The results showed that the effects of the toxic components were fairly complicated. Within the ranges of contents of the respective toxic components of the vaccines used in the present experiment, LPF appeared to enhance all the three potencies as the content increased, while the effects of endotoxin and HSF were either enhancing or suppressive depending on the antigenic components.

Antigens, Bacterial↗
PubMed1978

Attempts at analysis of toxicity of pertussis vaccine. III. Effects of endotoxin on leukocytosis in mice due to lymphocytosis-promoting factor and reference preparations for determination of lymphocytosis-promoting factor.

The effect of bacterial endotoxin on the change in peripheral leukocyte population in mice due to the lymphocytosis-promoting factor (LPF) was investigated. Endotoxin affected not only the total leukocyte count but also the leukocyte proportions at any observation time. Both the coefficient and the intercept of regression of the leukocytic response on dose of LPF were modified by endotoxin. Therefore, in a valid biological assay for LPF using the peripheral leukocyte count as a response, a common reference preparation available for any test materials, irrespective of presence or absence of endotoxin, will be impracticable. Two reference preparations were tentatively established, one being a vaccine and the other an LPF preparation containing little endotoxin. A unitage of LP activity was assigned to each reference preparation. The results also showed that an LPF material to be tested for its possible effects on the lymphatic tissues or the reticuloendothelial system should be free from endotoxin.

Animals↗
PubMed1976

A new biological assay method for histamine-sensitizing factor using survival time as a response.

A new biological assay method using survival time of mice as a graded response after histamine challenge has been developed for the histamine-sensitizing factor of pertussis bacilli. The method is relatively precise and reproducible in estimation and fairly sensitive in the validity tests of biological assay. Effect of endotoxin on the estimation by the proposed method was also investigated in case the method is applied to the control test of pertussis vaccine.

Animals↗
PubMed1975

Tables for estimating the mean of distribution of logarithms of titers based on data with a pooled serum sample.

A table was constructed for use in estimating the mean of distribution of logarithms of titers based on data obtained with a pooled material instead of those with individuals in a sample. A table of standard errors of the estimator was also constructed. Examples showing the utility and applicability of the tables were presented. Several relating problems were discussed.

Animals↗
PubMed1975

Toxicities of influenza vaccine: peripheral leukocytic response to live and inactivated influenza viruses in mice.

Intraperitoneal or intravenous inoculation of live or inactivated influenza virus induced two characteristic responses of the peripheral leukocytes in mice, an early appearing leukopenic response and late appearing lymphopenia. The former response usually developed and subsided within several hours, though the change in leukocyte population was fairly complicated depending upon the activity of the inoculated material, while the latter began several hours after inoculation and reached its minimum level in 10 to 20 hr. The agent responsible for the former may be virus pyrogen, while the latter seems to be caused by some substance(s) other than that. The early appearing leukopenic response was similar to that due to bacterial endotoxin in respect to the characteristic pattern of the change in peripheral leukocyte population, though it was relatively easy to distinguish one from the other by the length of the latent period and by the heat stability of the causative agent. Live or inactivated influenza virus causing the early appearing leukopenic response was found also to have the mouse body weight-decreasing toxicity. The significance of these findings in the laboratory control test of influenza vaccine for untoward reactions often observed in human inoculated with some inactivated influenza vaccines was discussed. The possible roles of the two agents, virus pyrogen and endotoxin, in the febrile response were mentioned.

Animals↗
PubMedDate not supplied

Endotoxin, histamine-sensitizing factor and lymphocytosis-promoting factor contents of pertussis vaccines produced in Japan.

The amounts of endotoxin, histamine-sensitizing factor and lymphocytosis-promoting factor contained in combined diphtheria-pertussis-tetanus and combined diphteria-pertussis vaccines recently produced in Japan were determined and the relationships among them were statistically analyzed. The estimated values in histamine-sensitizing units (HSU) and lymphocytosispromoting units (LPU) per human dose ranged from 0.3 to 6 and from 0.4 to 5, respectively. A fairly wide range of endotoxin contents, which were expressed in body weight-decreasing units (BWDU), was also demonstrated. All the ranges were larger than those expected from experimental error. There was a positive correlation between the HSU and LPU values although the individual HSU-LPU ratios ranged from 0.3 to 3, but the range was markedly larger than the width of the 95% confidence interval of the mean ratio. Negative correlation between BWDU and LPU was also significant, probably because of the relatively large number degrees of freedom, though the coefficient was fairly small; while that between BWDU and HSU was not significant. The frequency distribution of individual values of HSU was divided into two lognormal distributions. With one of the two groups obtained by this subdivision, a distinct positive correlation bewteen HSU and LPU was demonstrated, but with the other group there was little correlation. Some differences between the two groups were also found in the correlations between BWDU and the other two variates. No factors responsible for the separation of the groups have yet been found.

Animals↗