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Biomedical subjects

T Maki

Publications and source records attributed to T Maki.

At least 235 records · Page 13Linked to original sources
PubMed1983

[The applicability of pions to cancer radiotherapy. II. Theoretical analysis of the capture and absorption of pions in polymer].

A theoretical analysis was attempted to give a remaining number of pi meson, N(X), as function of depth X in a target, lucite as model, under a beam of pi meson. Under the assumption of three different elementary processes, pi-e Rutherford scattering, pi-decay and pi-nucleus interaction, N (X) was theoretically evaluated. It was shown that the estimated stopped points of pi particles agreed well with the experimentally obtained data if the pi-e Rutherford scattering were the main cause of pi momentum reduction. Since the decay of pi meson is negligible in the reduction of pi meson, N (X) is mainly due to pi-nucleus reaction in the region of a small depth but it is due to pi-nucleus Rutherford scattering at a point less than 1.5 cm before the stopped point of pi.

Elementary Particles↗
PubMed1983

[The age-related changes in serum 17-hydroxyprogesterone secretion in men].

In order to clarify the age-related changes in serum 17-hydroxyprogesterone (17-OHP) secretion in men, serum basal 17-OHP levels were determined in 203 healthy male subjects from 10 months to 116 years of age, and serum 17-OHP responses to dexamethasone (Dex), fluoxymesterone (FM), HCG and ACTH were compared between the young and elderly groups. The mean basal 17-OHP level remarkably increased from pubescence to the third decade and gradually decreased with advance in age after fifty. Basal serum 17-OHP level was correlated more closely with serum testosterone (T) than cortisol (F), and was suppressed more remarkably after the administration of FM than Dex in both groups. Serum 17-OHP increased with 2 peaks at 6 and 24 hours after HCG injection, and serum 17-OHP response to HCG was significantly greater in the young than in the elderly group. Furthermore, in the aged subjects with low serum T levels, serum 17-OHP response to HCG was remarkably decreased. Within 3 hours after ACTH injection, serum 17-OHP response to ACTH was significantly lower in the elderly than in the young group. On the other hand, 12 hours after ACTH administration, serum 17-OHP response was remarkably greater in the elderly group, and the F/17-OHP ratio was significantly lower than in the young. These data indicate a decline of Leydig cell function in the testis of the elderly male and also suggest the occurrence of enzyme deficiencies, especially impaired C17, 20 lyase activity, in adrenal steroid hormone synthesis with aging.

17-alpha-Hydroxyprogesterone↗
PubMed1982

Development of suppressor T cells by antilymphocyte serum treatment in mice.

Administration of rabbit anti-mouse lymphocyte serum (ALS) in mice results in the development of suppressor cells which can be detected by coculture mixed lymphocyte culture experiments. The putative suppressor cells inhibit nonspecifically the proliferative response as well as generation of cytotoxicity of normal responder cells. Suppressor activity is dose dependent and is not attributable to cell crowding, shifting of peak activity, or release of cell-bound ALS. Additional antigenic stimulation by skin allografting in ALS-treated mice shifts the specificity of suppressor cells from nonspecific to specific for skin donor alloantigen. ALS-induced suppressor cells are Lyt-1+2- T cells while suppressor cells present in ALS-treated, skin allograft-bearing mice are Lyt-1-2+ T cells. Both types of suppressor cells appear to bear I-J determinants. The possible mechanisms of suppressor cell induction by ALS and skin allografting are discussed.

Animals↗
PubMed1982

Functional characteristics of a Ficoll-separated mouse bone marrow cell population involved in skin allograft prolongation.

Treatment of recipient mice with donor bone marrow cells and anti-lymphocyte serum (ALS) results in extensive skin graft prolongation beyond that achieved in animals given only ALS. In this study, B6AF1 recipient mice were grafted with C3H/He skin on day 0, treated with ALS on days -1 and +2 and infused on day +7 with donor strain (C3H/He) bone marrow cells. Extensive graft prolongation was achieved either with 25 X 10(6) whole bone marrow cells or with 1 X 10(6) lymphoid-like cells derived from donor marrow that sediment at a rate of 3 mm/hr in a 2 to 4% Ficoll gradient at unit gravity. These allograft-prolonging lymphoid-like cells appear not to be CFUs cells, have suppressive activity in in vitro MLC assays, and contain both nylon wool adherent and non-adherent cells. These studies thus show that allograft promoting cells can be isolated from bone marrow utilizing Ficoll gradients. Functional studies suggest that 3 mm/hr sedimenting donor bone marrow suppressor cells may be involved in the induction of allograft prolongation.

Animals↗
PubMed1981

Prolongation of skin allograft survival in H-2 K and I region-incompatible mice by pretransplant blood transfusion.

The effect of donor specific and nonspecific pretransplant blood transfusion on skin allograft survival was studied in a mouse model, using skin donor-recipient combinations that differed at the K and I regions of the H-2 complex. In the first series of experiments, B6AF1 mice were treated with antilymphocyte serum (ALS) and grafted with DBA/2 skin. This donor-recipient combination differs in the K and I regions of the H-2 complex. Recipients were transfused 10 days before grafting with donor-specific DBA/2 blood or blood from various donors which were either completely incompatible at the H-2 complex with DBA/2 or shared various H-2 specificities with DBA/2. Only donor-specific DBA/2 blood or blood from donors sharing the K and I regions of the H-2 with DBA/2 prolonged DBA/2 skin graft survival. Donor-specific blood was effective over a wide interval between transfusion and grafting (days -50 to -10). In a second series of experiments using congenic strains of mice, the effect of pretransplant transfusions was studied in the B10.D2 to B10.A combination. These strains differ at the K and I region of the H-2, but share the same minor histocompatibility antigens. ALS-treated B10.A recipients were transfused either with donor-specific B10.D2 blood or blood from B10.BR which shares the minor histocompatibility antigens with B10.D2, but differs in the major antigens or DBA/2 blood which shares the majority histocompatibility antigens with B10.D2, but differs in the minor antigens. Only donor-specific blood or blood from the DBA/2 donor sharing the major antigens with the skin donor prolonged graft survival.

Animals↗
PubMed1981

Suppressor cells in mice bearing intact skin allografts after blood transfusions.

Evidence for the presence of suppressor cells in B6AF1 mice bearing long-term C3H skin grafts after multiple blood transfusions and antilymphocyte serum (ALS) treatment is described. Transfer of spleen cells from these mice into secondary B6AF1 recipients given ALS and C3H skin grafts resulted in marked prolongation of graft survival. The spleen cells were also capable of specifically inhibiting the proliferative response of normal B6AF1 responders to C3H stimulator cells in coculture mixed lymphocyte culture (MLC) experiments.

Animals↗
PubMed1981

Specific unresponsiveness to skin allografts in anti-lymphocyte serum-treated, marrow-injected mice: participation of donor marrow-derived suppressor T cells.

Sequential changes of cell-mediated immune reactivities were examined in anti-lymphocyte serum-(ALS) treated, C3H/He (C3H; H-2k) bone marrow-injected (C57BL/6 X A)F1 (B6AF1; H-2b/k.d) mice bearing enhanced C3H skin grafts. Spleen cells of these mice exhibited marked suppression of the proliferative response to phytohemagglutinin and concanavalin A. When the spleen cells were assayed for the direct lymphocyte-mediated cytotoxicity against H-2k targets, their lytic activity remained low until the time of graft rejection, in contrast to the increasingly high cytotoxic activity exhibited by spleen cells of control B6AF1 mice given only ALS and C3H skin grafts. When spleen cells of marrow-injected B6AF1 mice were cultured with mitomycin-C treated C3H spleen cells, the proliferative response was significantly suppressed the throughout the course, despite the early appearance of high "secondary-type" cytotoxic activity. Co-culture experiments demonstrated the presence of C3H antigen-specific suppressor cells in the ALS-treated, marrow-injected mice bearing intact allografts. Treatment of spleen cells with anti-H-2, anti-Thy 1 and anti-I-J sera and C revealed that the suppressor cells present late in the marrow-injected mice were T cells of donor C3H bone marrow cell origin.

Animals↗
PubMed1981

[Clinical experience with cefotiam in the field of pediatrics (author's transl)].

A clinical study on cefotiam (CTM) was performed in the field of pediatric infection, and the following results were obtained: The number of cases studied were six including 2 cases of U.T.I., 1 case of vaginitis and vulvitis, 1 cervical lymphadenitis, 1 absence of thigh and coxitis. Clinical responses to CTM were excellent in 3 cases, good in 1 cases but there was 1 exception who dropped out because of concurrent use of other antibiotics. As for bacteriological responses, CTM eliminated the pathogens E. coli and P. mirabilis from U.T.I., Staph. epidermidis and P. morganii, from vaginitis and vulvitis, H influenzae and Str. pneumoniae from cervical lymphadenitis and Staph. aureus from abscess of thigh. No side effect was observed except 1 case who showed an elevation of GOT, GPT and LDH. It is uncertain, however, wether this abnormality was resulted from the use of CTM or not, because the other antibiotics were used also.

Age Factors↗