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Biomedical subjects

M Takei

Publications and source records attributed to M Takei.

At least 199 records · Page 11Linked to original sources

Lymphoproliferative response to membrane extracts of nasopharyngeal carcinoma.

The tumor-associated antigen (TAA) was extracted from cultured cells obtained from nasopharyngeal carcinoma (NPC), and the specific immune reaction was studied by utilizing the proliferation reaction of lymphocytes from NPC patients. The following results were obtained. (1) The stimulation of lymphocytes by membrane soluble antigen (MS-Ag) was significantly different in the group of patients with NPC and the control groups (patients with malignant tumors of the head and neck and healthy individuals). Lymphocytes from the NPC patients gave a significantly higher stimulation index (SI) value with NPC MS-Ag, but a lower value with PHA, as compared with those of normal controls. (2) No definite correlation was observed in anti-Epstein-Barr virus (EBV) antibody titers. (3) As for the correlation with various histological types, apparently enhanced reaction was noted irrespective of the histological type of the cancer. (4) In connection with stage classification, the reaction was always negative in patients in stage IV. A particularly close correlation was noted between the degree of the response and the N classification. Some inhibitory factor affecting the LP reaction might appear with the progress of N and M.

Antibodies, Viral↗

Interaction of cinepazide with adenosine on guinea-pig atria.

The negative inotropic effects of adenosine and adenine nucleotides, such as ATP and cAMP, on guinea-pig atria were selectively and dose-dependently augmented by cinepazide in concentrations insufficient to produce any effect alone (3 X 10(-5) M-3 X 10(-4)M). Adenosine (10(-5) M, 10 microCi) was degraded to inosine and hypoxanthine during incubation with atrial tissue. Cinepazide (3 X 10(-4) M) retarded the degradation of adenosine, and the formation of inosine and hypoxanthine. Incubation of the atrial tissue with adenosine (8.1 X 10(-9) M, 0.1 microCi) resulted in accumulation of 3H-activity. Cinepazide (3 X 10(-5) M-3 X 10(-4) M) inhibited this accumulation. These results suggest that cinepazide potentiates the negative inotropic effect of adenosine on guinea-pig atria by preventing both its degradation by deaminase and its accumulation by atrial tissue.

Adenosine↗

C-peptide, insulin and proinsulinlike components in diabetic and nondiabetic human pancreas.

The contents of insulin and C-peptide extractable with acid alcohol from the tail of the pancreas and insulinoma were investigated, using gel filtration in seven nondiabetics including two patients with insulinoma and eight diabetics. The gel filtration patterns of both C-peptide and insulin in pancreatic extract were fairly stable even after the pancreas had been left for 14 hrs in the room temperature. In nondiabetics except cases of insulinoma the content of insulin in pancreas ranged from 1.42 to 4.56 U per gram and that of C-peptide from 8.76 to 25.63 microgram per gram wet pancreas. The proportion of proinsulinlike components (PLC) ranged from 0.01 to 2.04% of insulin plus PLC. In diabetics insulin content was low and ranged from 0 to 1.68 U per gram and that of C-peptide from 0 to 14.48 microgram per gram wet pancreas. In insulinoma, both insulin and C-peptide increased and PLC occupied 5.48 and 5.96%, respectively.

Adenoma, Islet Cell↗

Possible involvement of prostaglandins in the action of ATP on guinea-pig uterus.

ATP and other adenine derivatives, such as AMP and adenosine, at concentrations above 10(-6) M induced dose-dependent contractions of guinea-pig uterine strips. Treatment of the strips with nonsteroidal anti-inflammatory drugs, such as indomethacin, aspirin and phenylbutazone, at concentrations of 10(-6) to 10(-4) M irreversibly inhibited the contractions, without affecting those caused by acetylcholine and bradykinin. Arachidonic acid (10(-8)-10(-6) g/ml) and prostaglandins (E1, E2 and F2 alpha, 10(-9)-10(-7) g/ml) restored the inhibited uterine response to ATP, but the inhibition was reinstated on washing out of the arachidonic acid or prostaglandins. Furthermore, the prostaglandin antagonists polyphloretin phosphate (3 x 10(-5)-3 x 10(-4) g/ml) and SC 19220 (10(-6)-3 X 10(-5) M) selectively suppressed the action of ATP. In addition to the prostaglandin antagonists, 2,2'-pyridylisatogen, reported to be an ATP antagonist, at concentrations of 10(-6) to 3 x 10(-5) M selectively inhibited the response of uterine strips to ATP. These results suggest the involvement of prostaglandins in the actions of ATP and other adenine derivatives on guinea-pig uterine tissue and provide further evidence for ATP-stimulated prostaglandin formation in smooth muscle.

Adenine Nucleotides↗