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Biomedical subjects

A Iwamoto

Publications and source records attributed to A Iwamoto.

At least 163 records · Page 9Linked to original sources
PubMed1991

[Adsorption and desorption of aclarubicin into and from activated carbon particles as drug carrier--an in vitro study].

A new dosage form (ACR-CH), aclarubicin(ACR) adsorbed on activated carbon particles (CH), was studied for adsorption and desorption onto and from CH. The adsorption isotherm at 37 degrees C in saline and phosphate buffer (pH 7.4-7.5) were shown as M = 175 Co.15 and M = 207 Co.24, respectively (M = ACR amount adsorbed on CH, microgram/mg; C = ACR concentration in a free state, microgram/ml). In both fluids, CH adsorbed more than 100-1,000 times more amount of ACR than ACR in a free state. ACR-CH was lavaged 7 times and the released ACR in a free state was measured. The results showed that ACR-CH desorbed constantly a small amount of ACR, namely, 1.5-8 percent of initial concentration of ACR in a free state in saline, 0.1-10% in phosphate buffer, and 0.5-4.0% in Ringer's solution. Under the same conditions, desorption of ACR-CH was measured in dog's blood plasma. The first lavage made ACR-CH desorb at 25.7 +/- 0.85 percent of ACR initial concentration in a free state, and two times' to 7 times' lavage made 1-3%. Overall, 43.3 +/- 0.99% of ACR were desorbed from the activated carbon. It was concluded that ACR-CH slowly released a constant amount of ACR for a long period.

Aclarubicin↗
PubMed1990

H(+)-ATPase gamma subunit of Escherichia coli. Role of the conserved carboxyl-terminal region.

Cloned uncG genes (wild-type or in vitro mutagenized) for the Escherichia coli gamma subunit were introduced into the uncG mutant Gln-14----end), and the functions of the mutant subunits were studied. The F1's with Ala-283----end and Thr-277----end mutant gamma subunits had 63 and 14% of the wild-type ATPase activity, respectively, and mutants with these subunits showed reduced growth by oxidative phosphorylation, indicating that the 10 residues at the carboxyl terminus (286th residue) are important, but dispensable, for catalysis. On the other hand, F1 with a Gln-269----end gamma subunit was inactive. Replacement of conserved residues (Gln-269, Thr-273, or Glu-275) between Gln-269 and Leu-276 gave enzymes with significantly reduced ATPase activity (2-41% of that of the wild-type) and lower ATP-driven proton conduction. Thus these residues are required for the normal catalytic activity of F1, although they are not absolutely essential. Membranes with amino acid replacements (Thr-277----end, Gln-269----Leu, or Glu-275----Lys) and the frameshift mutation (downstream of Thr-277) had about 15% of the wild-type ATPase activity, but showed different degrees of ATP-dependent H+ translocation and growth yield by oxidative phosphorylation, suggesting that the gamma subunit, especially its carboxyl-terminal region, functions in coupling between catalysis and H+ translocation.

Amino Acid Sequence↗
PubMed1990

Clonal variation of adenylyl cyclase activity in a rat tumor cell line caused by change in G protein-catalytic unit interaction.

Two subclones of the rat XC cell line characterized by different morphology exhibited quite different adenylyl cyclase responses upon various stimulations. Upon treatment with cholera toxin, clone RK1 accumulated a high level of intracellular cAMP thereby changing its polygonal morphology to an elongated morphology, while the other clone, LK1, with a fibroblastic morphology, failed to increase the intracellular cAMP and remained morphologically unchanged. When membrane fractions derived from these two clones were stimulated with 10 microM forskolin, 10 microM GTP gamma S, or 10 mM NaF, five- to 20-fold more cAMP was accumulated in RK1-derived membranes than in LK1-derived membranes. With the same membrane fractions, upon treatment with Mn(+)+, which directly stimulates the catalytic unit, a high level of cAMP was accumulated both in RK1 and LK1, indicating that the catalytic function inducible by Mn(+)+ was similar in both clones. There was no significant difference in the level of expression of G protein alpha 2, alpha i (at least alpha i1 and alpha i2), and beta subunits between LK1 and RK1. Cholate extracts of the membrane proteins of LK1 and RK1 reconstituted the adenylyl cyclase activity of the cyc- variant of S49 lymphoma cells to the same level. Therefore, it is inferred that the defect in LK1 resides in the interaction of stimulatory G proteins and the actual catalyst.

Adenosine Diphosphate Ribose↗
PubMed1990

Affinity of intraperitoneally injected activated carbon particles adsorbing mitomycin C to tumor surface of Yoshida sarcoma.

A new dosage form of mitomycin C (MMC-CH) comprising 0.75 mg/ml of activated carbon particles adsorbing mitomycin C at 124 micrograms/mg and 7 micrograms/ml of mitomycin C in a free state was injected intraperitoneally to male rats of Donryu strain transplanted intraperitoneally with 10(7) cells/rat of Yoshida sarcoma 4 days before injection. The rats were subjected to autopsy within 60 min after injection. MMC-CH adhered selectively to the tumor surface of Yoshida sarcoma growing intraperitoneally rather than to the surface of organs such as small intestines which the surface cancer did not affect. Within 120 min after injection, mitomycin C concentration in the tissue samples was bioassayed. Intraperitoneally injected MMC-CH distributed high levels of mitomycin C to the tumor rather than to the unaffected organ located intraperitoneally. Animals killed by cancer after the treatment of MMC-CH were autopsied. Histological effects of MMC-CH were studied microscopically. Mitomycin C adsorbed on activated carbon particles induced degenerative changes in the tissues of tumors to which the activated carbon particles had adhered.

Adsorption↗
PubMed1990

[Follow-up study on anti-HBs levels in vaccines after two and three doses of HB vaccine (1)].

UNLABELLED: An HB prophylaxis vaccination that included a primary and secondary vaccination was carried out on persons working at this university hospital. In the primary vaccination, the subjects were inoculated the second time with a vaccine derived from human blood plasma obtained from the Kitazato Therapeutic Research Institute. The third time, they were inoculated with a vaccine from the Chemo-Sero Therapeutic Research Institute derived from a second-generation vaccine organized ferment. The vaccine used for the second inoculation was obtained from the Chemo-Sero Therapeutic Research Institute. RESULTS: A total of 254 subjects were inoculated with the HB prophylaxis vaccination. 1. Of the 216 subjects inoculated with the primary vaccination, at the time of the second inoculation, 65 subjects (30%) tested positive for antibodies 3-4 months following inoculation. There was an especially high rate among females between 20 and 50 years. Thirty-two subjects (15%) tested positive 15-16 months following inoculation with a high rate among females. 2. Among 132 subjects inoculated the third time with the primary vaccination (those who tested negative in the second inoculation of the above vaccine), 76 subjects (58%) tested positive for antibodies 8-9 months following inoculation with a generally high rate among females. Thirty-five subjects (27%) tested positive 15-16 months after inoculation with a high rate among females between 20 and 30 years and among males between 40 and 60 years. 3. Among the 38 subjects who were inoculated the second time with the secondary vaccination, 8 subjects (21%) tested positive for antibodies 5 months following inoculation, with a high rate among females in their 20's.

Adult↗
PubMed1990

[Follow-up study on anti-HBs levels in vaccinees after two and three doses of HB vaccine. (2)].

An HB prophylaxis vaccination that included a primary and secondary vaccination was carried out on persons working at the university hospital. In the primary vaccination group, the subjects were inoculated the second time with a vaccine derived from human blood plasma obtained from the Kitazato Therapeutic Research Institute. The third time, they were inoculated with a vaccine from the Chemo-Sero Therapeutic Research Institute derived from a second-generation vaccine organized ferment. The vaccine used for the second inoculation group was obtained from the Chemo-Sero Therapeutic Research Institute. Results were summarized as follows: 1) The primary vaccination group: (1) The number of the 153 subjects inoculated with the primary vaccination at the time of the second inoculation, 49 subjects (32%) tested positive for antibodies 3-4 months following inoculation. Thirty-two subjects (20%) tested positive 15-16 months following inoculation with a high rate among females. (2) Among 104 subjects inoculated the third time with the primary vaccination (those who tested negative the second inoculation of the above vaccine), 61 subjects (58.7%) tested positive for antibodies 8-9 months following inoculation with a generally high rate among females. Twenty-eight subjects (26%) tested 15-16 months after inoculation with a high rate among females between 20 and 30 years and among males between 40 and years. 2) The secondary group: Among the 38 subjects who were inoculated the second time with the secondary vaccination, 8 subjects (21%) tested positive for antibodies 5-6 months following inoculation, with a high rate among females in their 20's. 3) The rate of antibodies formation.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

[Basic investigation of saliva SIgA].

Saliva, which contributes to maintaining health in the oral environment, is affected by the physiological functions of the organism and their condition. Dental caries and periodontosis, both of which are oral diseases with frequent occurrence, require the presence of bacteria to occur. SIgA (secretory IgA), an immune globulin that is found in large quantities in substances secreted during salivation, has an antibacterial action. Thus, in conducting a basic investigation on the relationship between these factors, the author investigated what effect the speed of saliva secretion, a physiological factor of the saliva component, has on the SIgA value. Results showed that, regarding the relationship between the salivary SIgA value and the speed of salivary secretion, a negative correlation exists although this is weak in terms of relevance. The fact that the correlation displayed a tendency toward scattering indicates a need to pay attention when measuring the elements in the saliva to those factors that evidently have an effect on the composition of the saliva.

Humans↗
PubMed1990

[Toxicity of cis-platinum loaded with lactic acid oligomer microspheres in mice].

We have evaluated the acute toxicity of an experimental new dosage form administered intraperitoneally in mice, consisting of cis-platinum loaded with lactic acid oligomer microspheres (CDDP-ms). The LD50 value of the CDDP-ms was 23.8 mg/kg, which amounted to 176% of the LD50 of the cis-platinum solution (13.5 mg/kg). Autopsy findings revealed no additional toxicity due to this dosage form.

Animals↗
PubMed1990

[Intracavitary microspheres incorporating cisplatinum in the treatment of malignant effusions--clinical trials].

A new dosage form of cisplatinum (CDDP), lactic acid oligomer microspheres incorporating cisplatinum (CDDP-ms), is designed to slowly release 70% of contained CDDP. CDDP-ms's acute toxicity is as low as 57% of the toxicity of CDDP aqueous solution, and its therapeutic efficacy is statistically significantly strong as compared with that of CDDP aqueous solution, when examined with experimental peritoneal carcinomatosis induced by mouse M5076 ovarian sarcoma. Clinical trials were carried out in 10 patients with malignant ascites (gastric cancer 6, pseudomyxoma peritonei 2, colon cancer 1, pancreas cancer 1) and in one patient with pleural effusion (lung cancer). CDDP-ms at 100 mg/person in terms of CDDP was injected at bolus into the affected cavity. In the 10 patients with ascites, 7 responded completely, two partially and one did not respond. The patient with pleural effusion responded partially. The response rate was 91%. Five of the 11 patients complained of temporary nausea or vomiting. In 5 patients fever higher than 38 degrees C was seen. No other side effect such as kidney, nor liver-damage or blood cell count abnormality was noted.

Animals↗
PubMed1989

[Enhancing effect by anti-cancer drugs on growth inhibition of colon carcinoma in nude mice by monoclonal antibody and complement].

We investigated the possible sero-therapeutic application of monoclonal antibody-A7 against human colorectal cancer. In complement dependent cytotoxicity, A7 showed 59% cytotoxicity against SW1116 cells. In addition, the killing of tumor cells by A7 and C was enhanced when the tumor cells were pretreated with 2 micrograms/ml mitomycin and 40 micrograms/ml adriamycin. Next, we evaluated the in vivo antitumor effect of A7 alone and combined with MMC on human colon cancer (Colon-6) bearing nude mice. The group injected with A7 alone showed definite antitumor effect compared with the non-treated group. The A7+MMC group (MMC: 4mg/kg, A7: 1 mg/body, two times) showed enhanced antitumor effect compared with the groups administered A7 alone or MMC alone.

Animals↗
PubMed1989

T cell function and expression are dramatically altered in T cell receptor V gamma 1.1J gamma 4C gamma 4 transgenic mice.

We have characterized transgenic mice carrying a functional T cell receptor (TCR) C gamma 4 (V gamma 1.1J gamma 4C gamma 4) gene. Results indicate that active transcription of the C gamma 4 transgene can influence expression of the endogenous C gamma 4, C gamma 1 (V gamma 3-, V gamma 4-, V gamma 2-, or V gamma 5J gamma 1C gamma 1) and C gamma 2 (V gamma 1.2J gamma 2C gamma 2) genes, while the ultimate expression of other TCR delta, alpha, and beta chain genes, as well as the adult T cell response, are relatively unaltered. Cells expressing transgenic C gamma 4 and endogenous delta TCR transcripts can migrate to the skin as dendritic epithelial cells (DEC) even though C gamma 4 cells are rarely, if at all, found in the skin. Transgenic and control mice were compared at 2 weeks, 6-7 weeks, and older. At 2 weeks, the thymus of transgenic mice, particularly the medulla, was much larger than control. Moreover, peripheral lymphoid tissues of younger mice were markedly (as much as 100-fold) more immunoreactive (both Con A response and alloreactivity). These differences, although persistent, became smaller in older mice. The data suggest that transgene expression has a major effect on T cell development and reactivity.

Animals↗
PubMed1989

5' flanking and first intron sequences of the human beta-actin gene required for efficient promoter activity.

We have identified a CCAAT box element that is required for the efficient transcription of the human beta-actin gene. Both in vivo transient transfection assays in cultured HeLa cells and in vitro run-off transcription assays in HeLa whole cell extracts demonstrated the requirement of this element for efficient promoter activity. A gel mobility shift assay revealed a Hela nuclear factor that specifically interacted with the beta-actin CCAAT element in vitro; mutation of the first three base pairs of the CCAAT pentanucleotide abolished binding of this factor. Competition gel shift experiments revealed that three sequence elements located within the beta-actin promoter, each containing a CC(A/T)6GG motif similar to that contained within the c-fos serum response element, were able to bind a different nuclear factor, serum response factor (SRF). One of these CC(A/T)6GG motifs is contained within a first intron fragment that enhanced transcription from a heterologous promoter in vivo.

Actins↗
PubMed1989

Effect of intraperitoneal injection of mitomycin C adsorbed on activated carbon particles on induction of cytolytic peritoneal macrophages of mice.

The effects of the intraperitoneal injection of mitomycin C adsorbed onto activated carbon particles (MMC-CH) were assessed on the host immune status and the induction of cytolytic peritoneal macrophages (PM) in mice in comparison with an aqueous MMC solution (MMC-AQ). PM from inbred C57BL/6 mice and syngeneic B16 melanoma cells were used as the effector and target cells for the PM-mediated cytotoxicity assay. After a single injection of MMC-AQ (at the dose of 1/2 LD50), the weights of thymus and spleen and the 3H-thymidine uptake of spleen cells stimulated by concanavalin A were markedly decreased compared to those following injection of MMC-CH containing the same dose of MMC. A significant difference was found in the chronological changes of peritoneal exudate cell (PEC) numbers and PM cytolytic activity between the MMC-AQ- and MMC-CH-treated mice. One day after MMC-AQ injection, the PEC numbers were decreased markedly. However, they increased ten-fold after MMC-CH injection and the PM cytolytic activity was significantly higher after MMC-CH injection than after MMC-AQ injection during the first 3 days. The present results suggest the possible superiority of MMC-coated charcoal over free MMC both because of a lessening of the effects on host immunity due to prolonged slow drug release and because of the increase in cytolytic macrophages that was induced.

Adsorption↗
PubMed1989

[Hepatitis B virus and epidemiological study on efficacy of HBIG and vaccine for the prevention of type B hepatitis after accidental exposures among medical staffs (2)].

The best method of preventing HBV is accurate perception on the part of the patient. There is a need for sufficient care regarding patient blood with HBsAg (+), HBeAg (+) and HBc high-antibody titer. The following is a report on a follow-up survey regarding antibody titer following dosages of HBIG 2 V and 1 V and administration of a vaccine along with dosage of HBIG 1 V. 1. Dosage of HBIG 2V: (Female) Antibody titer was recognized two days following dosage. It continued for two weeks and disappeared after four weeks. (2) (Male) Antibody titer was recognized one day following dosage but disappeared after two weeks. 2. Dosage of HBIG 1 V: (Female) Antibody titer (-) was recognized two days after dosage and nine days after dosage. It continued for about one month and disappeared after five months. 3. Administration of three vaccines and dosage of HBIG 1 V: (Female) Antibody titer was recognized two days after HBIG 1 V dosage and continued for 18 days but disappeared after three months. Antibody titer was recognized again after about eight months and showed signs of continuing for 13 months.

Female↗
PubMed1989

[Basic investigation of saliva and serum SIgA].

The local immune mechanisms of which the IgA system is central are characterized by activity that is independent of the immune response of the body as a whole. Among these mechanisms, SIgA (secretory IgA) plays an important role. In measuring saliva/serum SIgA, the author used an EIA SIgA column set for saliva and for serum. Investigation of saliva SIgA concerned the correlation with saliva flow speed while investigation of serum SIgA concerned patients with oral dysfunctions and those inoculated with the HB preventive vaccine. A slightly negative correlation was observed between the saliva flow speed and the saliva SIgA value. Regarding serum SIgA, effect from the liver function was considered to be a factor among patients with oral dysfunctions. The antibody positive subjects among those inoculated with the HB vaccine are considered to reflect the response level of the antibody factor as well as individual differences in sensitivity and immune response. Among antibody negative subjects, however, there was a general tendency toward high values.

Humans↗