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Biomedical subjects

T Iwata

Publications and source records attributed to T Iwata.

At least 415 records · Page 23Linked to original sources
PubMed1979

Evaluation of functional thymic hormones in Arabian horses with severe combined immunodeficiency.

Arabian horses with severe combined immunodeficiency disease (SCID) were evaluated for thymic hormone activities using thymic extracts and sera. Extracts prepared from thymus of SCID horses were able to increase the number of spleen cells responding to sheep red blood cells in irradiated, bone marrow-reconstituted mice. In addition, ultrafiltrates prepared from sera of these immunodeficient horses, which contained material with molecular weight of less than 50,000 Daltons could (a) induce a population of human bone marrow precursor cells to differentiate into cells bearing SRBC receptors and form spontaneous E-rosettes, a characteristic of T lymphocytes, and (b) stimulate cyclic adenosine monophosphate (AMP) synthesis in mouse thymocytes. Based on in vivo and in vitro effects, it was concluded that the defect of these Arabian horses with severe combined immunodeficiency disease did not involve a complete thymic hormone inadequacy.

Aging↗
PubMed1978

Chlorpromazine causes vesicle population changes in the monoaminergic synapse of the rat caudate nucleus.

The population of monoaminergic synaptic vesicles in the rat caudate nucleus remained unchanged or slightly decreased 3 h after chlorpromazine (CP) administration, and clearly increased after 24 h. The diameter of synaptic vesicles became smaller when the vesicles increased. These findings suggest that CP causes presynaptic blocking in part of its actions and leads to a condition in which neural transmission is inactive. In the control animals, population of the vesicles tended to fluctuate following the circadian rhythm.

Animals↗
PubMed1978

Synthesis and antitumor activity of preactivated isophosphamide analogues bearing modified alkylating functionalities.

In search of cancer chemotherapeutic agents with greater efficacy than cyclophosphamide, 4-hydroperoxyisophosphamide analogues bearing modified alkylating functionalities such as 2-bromoethyl, 2-iodoethyl, 2-methyl-sulfonyloxyethyl, and 2-ethylsulfonyloxyethyl groups were prepared by ozonolytic cyclization reaction of N,N'-substituted 3-butenyl phosphorodiamidates. Comparative cytotoxicity against L1210 cells and antileukemic life-span activity against L1210 implanted BDF1 mice of the newly synthesized compounds were tabulated. The 4-hydroperoxyisophosphamide analogues which have different alkylating groups in a molecule showed slightly greater cytoxicity in vitro than those with the same alkylating groups. Most of the compounds having different alkylating groups also showed high antileukemic activity in vivo. Among them, the highest efficacy was found for 2-[N-methyl-n-(2-chlorethyl)]amino-3-(2-methylsulfonyloxyethyl)-4-hydroperoxy-1,3,2-oxazaphosphorinane 2-xoide (NSC 280122D) whos life-span activity was also greater than that of 4-hydroperoxyisophosphamide, cyclophosphamide, and isoposphamide. The superiority of this compound was especially apparent by oral administration.

Alkylating Agents↗
PubMed1978

Pathological study on amyloidosis--relationship of amyloid deposits in the aorta to aging.

Senile aortic amyloidosis in 224 autopsy cases over 40 years was investigated comparing cardiac and pancreatic amyloidosis in them. A total of 176 cases of aortic amyloidosis was found for an average incidence of 79%. Under the 5th decade the incidence was 51% and it rose sharply with age and reached 95% in over the 8th decade. The incidence of cardiac amyloidosis also increased with age, but it was always higher in the aorta. Aortic and cardiac amyloid were both positive in the DMAB method for tryptophan. The major part exposed to amyloidosis in the aorta was the media. The medial amyloid consisted of numerous minute deposits and had no relation to atherosclerosis. Some comments about the pathogenesis of senile amyloidosis were also mentioned.

Adult↗