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Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

At least 793 records · Page 44Linked to original sources
PubMed1985

[Effect of calcium entry blocker, nimodipine, on the cerebral function and metabolic recovery following experimental cerebral ischemia].

Ischemic deporalization of cell membranes is associated with a precipitous influx of calcium from the extracellular to the intracellular compartment, and it is suggested that increased intracellular calcium in ischemic brain leads to an activation of phospholipase and to increase of the concentration of free fatty acids, in particular arachidonic acid, with energy depletion. The objective of the present study is to test whether calcium entry blocker, nimodipine, prevent increase of free fatty acids and metabolic disturbances during ischemic period, and promote functional and metabolic recovery after recirculation. Severe forebrain ischemia in rats was induced by four-vessel occlusion with reducing the systolic arterial pressure to 100 mmHg. After forebrain ischemia had been maintained for 30 minutes, recirculation was started by removal of the arterial clamps of bilateral common carotid arteries and by increasing systemic blood pressure to the preischemic level. The EEG was continuously recorded from gold-coated screws inserted bilaterally in the parietal bones with the tips in extradural position, against a reference inserted prefrontal bone. Analysis of power spectrum of EEG activity was done by Berg Fourier Analyser. The brain were frozen in situ with liquid nitrogen before, during and after ischemia and then chiselled out during irrigation with liquid nitrogen. Concentrations of ATP, ADP, AMP and free fatty acids in brain tissue were determined with high performance liquid chromatography. Nimodipine, 10 micrograms/kg, was given intravenously 2-3 minutes before induction of ischemia, and an infusion of 1 microgram/kg/min was continued during ischemic and postischemic periods.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

[Fundamental and clinical studies on aztreonam in the gynecological field].

Aztreonam (AZT), a new monocyclic beta-lactam antibiotic was studied on clinical efficacy for infectious disease in gynecological field. At about 80 minutes following intravenous injection of 1 g dose of AZT, it penetrated well into internal genital organs at therapeutic levels. Moreover it transferred very fast and enough into intrapelvic dead space exudate, and its level was kept still as high at 12 hours after administration. AZT was given to 20 women affected with gynecological infectious disease. The outcome of AZT therapy was as follows: effective in 5 out of 6 patients (83.3%) administered intravenously and in all of 14 patients (100%) received intramuscularly. Notable adverse effects or abnormal laboratory findings were not observed except 1 case of diarrhea and 2 cases of transient and slight elevation of serum CPK and transaminases. Based on these results, we may conclude that AZT is a highly effective and a very safe antibiotic for the treatment of infectious disease in gynecological field.

Adult↗
PubMed1985

[Relief of experimental cerebral vasospasm by the intrathecal administration of a calcium antagonist (diltiazem)--in comparison with intra-arterial administration].

The effect of an intra-arterial administration of diltiazem on experimental cerebral vasospasm was previously reported by us. In the present study, the effect of diltiazem on cerebral vasospasm, intracranial pressure and systemic blood pressure were investigated using dogs. Cerebral vasospasm was induced by an injection of 5 ml of autologous blood into the cisterna magna. Diltiazem (10(-6) M) was administrated into the cisterna magna and the dilating effect of the drug on the basilar artery was monitored angiographically. The intrathecal administration of diltiazem relieved the vasospasm for more than 30 minutes, same as that of the intra-arterial administration. However, the intracranial and blood pressures remained unchanged. The changes of concentration of the drug in CSF and plasma following the intracisternal administration of 14C-diltiazem were measured using rabbits. The concentration of an administered diltiazem in CSF and plasma was quickly decreased and reduced to 2% of its initial value after one hour (t1/2 = 8 min). Our results show that even the concentration of diltiazem is very low in CSF, the vasodilating effect continues for more than 30 min. This suggests that the intrathecal administration of diltiazem may be useful for the prevention and treatment of the cerebral vasospasm following subarachnoid hemorrhage.

Animals↗
PubMed1985

[Comparison of in vitro antibacterial activities of new cephems against clinical organisms (isolated between June 1983 and January 1984)].

We compared the in vitro antibacterial activities of ceftizoxime (CZX), cefotaxime (CTX), cefmenoxime (CMX), cefoperazone (CPZ), ceftazidime (CAZ), latamoxef (LMOX) and cefotetan (CTT) against 2,729 strains of 11 organisms freshly isolated from 10 medical institutions in Japan between June 1983 and January 1984 and obtained the following results: Against S. pyogenes, LMOX and CTT, which have the methoxy group at the 7 position, were less active than the other drugs. LMOX inhibited 80% of S. pyogenes at 0.78 micrograms/ml; CTT, at 1.56 micrograms/ml; but CZX and CTX inhibited 100% at 0.025 micrograms/ml or lower; CMX, at 0.05 micrograms/ml; and CPZ and CAZ, at 0.20 micrograms/ml. Against H. influenzae, E. coli, K. pneumoniae, P. mirabilis and indole-positive Proteus, these test antibiotics, especially CZX, CTX and CMX, which have the aminothiazolyl methoxyimino group, were potently active. Against S. marcescens CZX and CAZ were more active than the other drugs and against P. aeruginosa CAZ was more active than the other drugs. The test organisms did not tend to acquire resistance to these cephems when our results were compared with the results obtained at the development period.

Bacteria↗
PubMed1985

Dynamic analysis of changing features of tumor cells incubated with antitumor agents in vitro and its application for predictive activity assay of antitumor agents.

Continuous observation of living malignant cells (L1210) in a specially devised glass observation chamber with an inverted microscope made it possible to classify various cellular morphological features induced by antitumor agents into the following four stages: 1) an initial stage consisting of cytoplasmic granulation and coloring, 2) an intermediate stage of shrinkage of nuclei, increases of vacuoles and cytoplasmic budding, 3) a determinate stage of cell ballooning and 4) the terminal stage (cell ghost). Both the initial and intermediate stages are characterized by cellular changes that appear at an early phase and remain opportunistic in terms of viability. Emergence of these cellular changes is largely dependent on the specific mode of action of antitumor agents. In contrast, definite irreversibility in the changes found in both the terminal and determinate stages was confirmed by continuous observation until the cells showed lytic or ghost features, using a video-recording system. A plot of the number of cells counted in both the determinate and terminal stages versus the time-dose schedule is designated as the "time-dose-response" plot, and this proved useful for estimating the characteristics of the antitumor agents tested and the actions of new antitumor agents on malignant cells (predictive activity assay graph).

Animals↗