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Biomedical subjects

S Uchida

Publications and source records attributed to S Uchida.

At least 217 records · Page 12Linked to original sources
PubMed1996

Identification of a new outwardly rectifying Cl- channel that belongs to a subfamily of the ClC Cl- channels.

A new outwardly rectifying Cl- channels (ORCC) that belongs to ClC Cl- channel family has been identified from rat kidney and designated as ClC-5. ClC-5 cDNA encodes a polypeptide of 746 amino acids, which is indicated by hydrophobicity analysis to have structural features that are common of the ClC family. However, the amino acid sequence was weakly homologous to those of other ClC Cl- channels except for ClC-3, which we recently identified as a Ca2+-sensitive ORCC. Northern blot analysis of rat tissues showed that ClC-5 mRNA was predominantly expressed in the kidney and colon. To characterize the functional properties of ClC-5 by whole cell patch-clamp technique, we established the stably transfected CHO-K1 cell line using intranuclear microinjection technique. The transfected cells induced outwardly rectifying and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid-sensitive Cl- currents on whole cell configuration. Following the identification of two highly homologous ORCCs, ClC-3 and ClC-5, a new subfamily encoding ORCC has emerged in the ClC family. Furthermore, ClC-5 was almost identical to a partial sequence of human cDNA that is related to Dent's disease. The molecular structure and functional properties of ClC-5 will provide an important insight into ORCCs and the pathogenesis of Dent's disease.

Animals↗
PubMed1996

Flunitrazepam effects on human sleep EEG spectra: Differences in NREM, REM and individual responses.

Flunitrazepam (FNZ) (4mg), an intermediate type benzodiazepine (BDZ) hypnotic, was administered orally to five healthy male subjects (Ss) for seven consecutive nights. Sleep EEG from the baseline night (BLN), the initial drug night (IDN), the fourth and the seventh drug nights (4DN, 7DN) was subjected to fast Fourier transform (FFT) analysis. During NREM sleep of 4DN and 7DN the sigma band (11.0-12.5 Hz) activity was similarly enhanced in every S. In REM of 4DN and 7DN beta band (23.0-29.0 Hz) was enhanced, but with larger variations among Ss. High intra-individual consistency of the relative EEG power patterns on 4DN and 7DN was observed. These results suggest that 1) EEG responses to FNZ are different in sleep states; explorations of these differences may provide better understandings of sleep mechanisms, and 2) individual variations in EEG responses may reflect individual variations of the BDZ receptor system. These methods may be useful for exploring receptor changes in neuropsychiatric disorders.

Adult↗
PubMed1996

A sustained increase in beta-adrenoceptors during long-term therapy with metoprolol and bisoprolol in patients with heart failure from idiopathic dilated cardiomyopathy.

Effects of long-term therapy with beta 1-selective antagonists (metoprolol, bisoprolol) on beta-adrenoceptors in lymphocytes of patients with idiopathic dilated cardiomyopathy (DCM) were examined. There was a significant reduction in the number of lymphocyte beta-adrenoceptors in patients with DCM compared to that in healthy volunteers, as demonstrated by a selective decrease in maximum number of binding sites (Bmax) for (-)-[125I]iodocyanopindolol (CYP). A therapy with metoprolol and bisoprolol in these patients caused a marked increase in lymphocyte beta-adrenoceptor density. The significant increase was observed from 2 or 3 months after the start of therapy with these drugs, and it was maintained during the therapy for 24 months. The left ventricular ejection fraction in patients with DCM was improved by the long-term therapy with metoprolol and bisoprolol, and this effect seems to be correlated with an observed enhancement of lymphocyte beta-adrenoceptors in the time course. Also, the increase in lymphocyte beta-adrenoceptors appears to be correlated with a gradual amelioration in circulating catecholamine levels by the long-term therapy with beta-adrenoceptor antagonists in patients with DCM. Thus, the present study suggests that beta-adrenoceptors in lymphocytes of patients with DCM are up-regulated by a long-term therapy with metoprolol and bisoprolol.

Adrenergic beta-2 Receptor Antagonists↗
PubMed1996

Flunitrazepam effects on human sleep EEG spectra. II: Sigma and beta alterations during NREM sleep.

Flunitrazepam (FNZ) is known to enhance the higher EEG frequencies, including sigma (10-15 Hz) and beta (20-28 Hz). Both sigma and beta frequency bands show an inverse relationship with delta (0.3-3 Hz) during NREM periods, as we have previously reported. It is not known whether generation of these two EEG frequencies is mediated by the same or different neuronal mechanisms. In this report, we compare alterations of delta, sigma and beta EEG induced by FNZ (4 mg) orally administered to five healthy male subjects for seven consecutive nights. Sleep EEG on the baseline night (BLN), and the fourth and seventh drug nights (4DN, 7DN) was subjected to fast Fourier transform (FFT) analysis. On drug nights, sigma was enhanced without regard to delta amount, but beta was enhanced only during epochs containing low delta. Thus, sigma and beta EEG were altered differently by the same pharmacological agent. These results suggest that sigma and beta EEG are mediated by different neuronal mechanisms.

Adult↗