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K Iwasa

Publications and source records attributed to K Iwasa.

125 records · Page 7Linked to original sources
PubMed1976

[Experimental study on the changes of blood pressure induced by afferent stimulation on the somatic nerves (author's transl)].

It has been shown by many authors that afferent stimulation of various somatic nerves results in the different types of responses with regard to blood pressure and heart rate. It was revealed by Hunt that afferent "weak" stimulation of the somatic nerves caused depressor responses, and "strong" stimulation, pressor responses. Ranson and Gordon thought that the depressor response to the afferent stimulation of the somatic nerves would involve the thick myelinated nerve fibers, and the pressor response, the fine non-myelinated nerve fibers. On the other hand, it has been postulated that the socalled chest pain and/or nonspecific complaints observed in patients with myocardial infarction, angina pectoris and neurocirculatory asthenia (NCA) are related to some alterations at the cervical and thoracic vertebral levels of the spinal cord or nerve roots. Maekawa, Hayase and Konishi attached importance to the presence of subclinical arachnoiditis adhesiva cerebrospinalis at the cervical and thoracic vertebral levels in patients of NCA. These facts suggests that the contribution of the spinal cord and the nerve roots to the circularoty system is different between the cervico-thoracic levels and the lumbar levels. Based on these facts, the author stimulated the somatic nerves of both the forelimbs and the hindlimbs afferently in alpha-chloralose anesthetized dogs, with a train of square electric pulses for 20 seconds, and studied the response of the circulatory system to such stimuli.

Afferent Pathways↗
PubMed1975

Examination of the limiting laws of polyelectrolytes and counterion condensation II.

The two phase model of polyelectrolyte solutions, which has been developed recently, is examined in a further detail. The binding free energy, which was introduced in the previous paper (J. Chem. Phys. 81 (1977) 1929), is replaced by the entropy of the condensed phase. This replacement leads to a detailed picture of the condensed phase. In a mixed system of mono- and divalent counterions, a couple of possibilities are examined in interpreting the condensation volume, which corresponds to the condensation entropy.

Journal Article↗
PubMed1971

[Pericarditis].

Explore the source record for details and available documents.

Adult↗
PubMedDate not supplied

Alzheimer's disease and estrogen.

The preventive effect of estrogen on Alzheimer's disease (AD) has become clear with epidemiological data. Therapeutic effects of estrogen have not yet been established. In this presentation, we report our new basic and clinical data. The estrogen receptor, (ER)alpha, and ERbeta mRNA were investigated in rat brain. Estradiol-17beta (E(2)) treatment following OVX reduced the levels of ERalpha mRNA in the hypothalamus. In the substantia innominata (SI), the number of choline acetyltransferase immunoreacive cells increased significantly in the estrogen treatment rat. The neurons in SI projecting to the forebrain cortex contained ERalpha. Increasing amounts of intracellular calcium, peroxidation, and apoptosis with amyloid beta were suppressed in neuronal cells from rat pheochromocytoma (PC12) cells with E(2). ERalpha cDNA transfected PC 12 cells elaborated more neurite-like processes with E(2). In clinics, we are currently preparing vaginal progesterone tablets, which essentially may concentrate in the endometrium to prevent endometrial cancer, with few general circulation of progesterone inviting less depression. The therapeutic effects of cyclic estrogen, such as its preventive effect, are suggested in these studies, at least on mild AD.

Alzheimer Disease↗
PubMedDate not supplied

Atheroprotective effect of estriol and estrone sulfate on human vascular smooth muscle cells.

In patients with atherosclerosis, fibrosclerotic focuses are induced by multiplication of vascular smooth muscle cells (VSMC), and they are regulated by cytokines and regulators. There have been few reports about the atheroprotective effect of estriol (E(3)). Estrone sulfate (E(1)-S) is the predominant estrogen of conjugated equiline estrogens, which is commonly used in hormone replacement therapy, but it should be hydrolyzed by steroid sulfatase (STS) to enter the cells of target tissues. The purpose of this study was to detect STS in VSMC and to investigate whether E(3) and E(1)-S have atheroprotective effects like E(2). First, we detected the presence of STS mRNA in VSMC by in situ hybridization. We then examined the changes in the expression of mRNAs of cytokines, namely, PDGF-A chain, IL-1, IL-6 and TGF-beta, in VSMC, in the presence and absence of E(3) and estrogens. As a result, the expression of PDGF-A chain, IL-1 and IL-6 mRNAs was suppressed by E(3) (P<0.05 vs control) significantly like E(1)-S and E(2), but that of TGF-beta mRNA was not significantly affected by any estrogen. These results indicate that E(1)-S can be hydrolyzed by STS in VSMC, and that E(3) may regulate the cytokines by suppressing the production of mRNAs. It is suggested that there is a possibility of E(1)-S and E(3) having a direct effect on vessels in atherogenesis.

Arteriosclerosis↗
PubMedDate not supplied

Reinvestigation of the conformations of a variety of hexahydrobenzo[c]phenanthridine alkaloids by 470 MHz PMR and 50 MHz CMR spectroscopy.

The high resolution pmr and cmr spectra of a variety of benzo[c]phenanthridine alkaloids and their CF3COOD salts were examined. The chemical shift of H-14 was found to be a reliable indicator of the orientation of the N-methyl group. The conformations of the C rings were assigned on the basis of the coupling constants between H-11 and the two H-12 protons. On the basis of the pmr spectra of (+)-14-epicorynoline (9) and (+/-)-14-epicorynoline-6,6,12 alpha-d3 (13), a revision of certain previous C ring conformations is indicated.

Alkaloids↗
PubMedDate not supplied

Exposure to sorbitol induces resistance to cisplatin in human non-small-cell lung cancer cell lines.

Cisplatin is the most active anticancer agent for lung cancer. It has been reported that intracellular accumulation of cisplatin is important in determining resistance to cisplatin, which may be modulated by Na+, K(+)-ATPase activity. On the other hand, it is well-known that sorbitol, a metabolite of glucose mediated by aldose reductase, reduces Na+, K(+)-ATPase in diabetic neuropathy. In this study, the effect of exogenous sorbitol on Na+, K(+)-ATPase activity and sensitivity to cisplatin was evaluated using human non-small-cell lung cancer (NSCLC) cell lines. In the NSCLC cell lines, EBC-1, PC-3, and RERF-LC-MS the cytotoxicities of cisplatin were impaired by exposure to sorbitol in these cell lines. Na+, K(+)-ATPase was inactivated and intracellular accumulation of cisplatin was decreased by the exposure. These results suggest that accumulation of sorbitol may induce resistance to cisplatin in NSCLC cells, and diabetes poorly controlled may be one of the determinants of the antitumor effect of cisplatin in NSCLC.

Carcinoma, Non-Small-Cell Lung↗