Electronic structure of rare-earth hexaborides.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to T Nanba.
Explore the source record for details and available documents.
A case-control study was conducted to examine factors relating to discontinuation of domiciliary care for the bedridden elderly in Shinagawa-ku, Tokyo. Cases were bedridden residents aged 65 years and over who had abandoned home care and applied for admission to live in a special nursing home for the aged between April and September in 1990 after being recipients of welfare allowances for disabled elderly. Controls were bedridden residents who continued to be given home care and matched to cases by sex, age and beginning month of the receiving of allowances. Among 50 cases and 94 controls interviewed, we obtained responses from 31 cases (62%) and 60 controls (64%). The main results were as follows: 1. During the home-care period, ADL (activities of daily living) of cases, especially walking ability, deteriorated more severely than in controls. Night delirium also appeared more frequently in cases. 2. The primary caregivers of cases were older than those of controls. Remarkable differences between cases and controls were observed in the family structure, the number of family members and the number of sub-caregivers. Cases tended to live alone or live with a spouse only, and with smaller number of family members and caregivers. 3. Case lived more frequently in houses with small numbers of rooms and without rooms of their own. 4. As regards utilization of domiciliary care services, cases used dispatch of home helpers more frequently and used day services less frequently.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Recently, it has been suggested that antidepressant drugs exert their pharmacological action through functional changes in the adrenergic-receptor coupled adenylate cyclase system. In the present research, we examined the direct effects of antidepressants on adenylate cyclase (A-cyclase) activity by in vitro incubation of cell membranes from the cerebral cortex of rats with these drugs. All antidepressants examined, such as imipramine, clomipramine, amitriptyline, desipramine, mianserin and zimelidine inhibited A-cyclase in a dose dependent manner. Antidepressants did not exert any influence on Mn2+-induced elevation of A-cyclase, but significantly suppressed F(-)-stimulated A-cyclase activity. GTP-induced elevation of A-cyclase was completely inhibited by prior incubation with antidepressants. Our conclusion, therefore, is that antidepressants may reduce A-cyclase activity not by inhibiting the function of the catalytic unit of A-cyclase, but by suppressing the N-protein function.
Explore the source record for details and available documents.
Forskolin (FK), a reversible activator of adenylate cyclase, markedly enhanced the expression of interleukin-2 receptor (IL-2-R) on a human natural killer (NK)-like cell line, YT. The FK-induced increase in IL-2-R on YT cells closely correlated with an increase in intracellular cyclic AMP (cAMP) level, and was mimicked by dibutyryl cyclic AMP (dbcAMP). FK induced both high and low affinity IL-2-R on the cells. Using a cDNA for the IL-2-R as a probe, the FK-induced IL-2-R expression was shown to be associated with an increase in IL-2-R mRNA. FK also enhanced the IL-2-R expression on a human T lymphotrophic virus I (HTLV-I) positive T-cell line (YTA-1H) and augmented the phorbol ester-induced expression of IL-2-R on HTLV-I negative T-cell lines (HSB-2 and HPB-ALL). These results suggest the possibility that the stimulation of adenylate cyclase may serve as a pathway leading to activation of the IL-2-R gene in certain types of lymphocytes.
An ATPase was newly identified on the inner face of the plasma membrane of the extremely halophilic archaebacterium Halobacterium halobium. The enzyme was released into an alkaline EDTA solution and purified by several chromatographic steps in the presence of sulfate at 1 M or over. The molecular weight of the native enzyme was around 320,000; it is most likely composed of two pairs (alpha 2 beta 2) of 86,000 (alpha) and 64,000 (beta) subunits. The enzyme hydrolyzed ATP and other nucleoside triphosphates but neither ADP nor AMP. The enzyme required divalent cations, among which Mn2+ was most effective (Mg2+ activated 35% of Mn2+). The ATPase activity was optimum at pH between 5.5 and 6, particularly in a nearly saturated Na2SO4 (or Na2SO3) solution, while it was very low in a chloride salt solution even at 4 M at any pH. The Km value for ATP was 1.4 mM and the K1 value for ADP (competitive to ATP) was 0.08 mM. Neither azide (a specific inhibitor for F0F1-and F1-ATPase) nor vanadate (for E1E2-ATPase) inhibited the enzyme. The ATPase was stable at high concentrations of sulfate. At low concentrations of salts, or at low temperatures even in high NaCl concentrations, the enzyme was inactivated. Although the ATPase isolated here from halobacterial membrane has such unusual characteristics, it is the most probable candidate for the (catalytic part of) halobacterial ATP synthase, which differs from F0F1-ATPase/synthase (Mukohata et al. (1986) J. Biochem. 99, 1-8; Mukohata and Yoshida (1987) J. Biochem. 101, 311-318).
Restriction endonuclease analysis was done on mitochondrial DNA (mtDNA) from 19 plasmodial strains of Physarum polycephalum. The extent of mtDNA variation among these strains was high in comparison with other organisms, and provides a useful source of cytoplasmic genetic markers. The strains were classified into seven groups according to their mtDNA types. Although plasmodia of P. polycephalum are diploid, formed by fusion of amoebal isogametes, each of the 19 plasmodia possessed mtDNA of only a single type. The transmission pattern of mtDNA during plasmodium formation was studied by mating pairs of amoebal strains that contained mtDNA of different types. Transmission was uniparental; the plasmodia that were formed carried mtDNA with the restriction pattern of only one of the two parental types. Since diploid zygotes develop into plasmodia by repeated mitotic cycles in the absence of cell division, it is clear that this uniparental transmission of mtDNA does not depend upon random partitioning either of mitochondria or of mtDNA molecules during cell division.
In many cases of acoustic tumor the hearing loss is gradually progressive, but some cases of acoustic tumor show a sudden onset of hearing loss. In this paper we report two interesting cases of acoustic tumors which were diagnosed as sudden deafness at the first examination. Being treated with steroid hormones, their hearing was partially recovered. But the hearing loss recurred in both cases. At the second examination, CT showed the cerebellopontine angle tumors. So it was emphasized that careful questioning as well as the caloric test and the auditory brainstem response (ABR) was important. If one of these tests shows abnormality, the patient should be examined by the CT scan. The same may be said of patients who show recovery due to steroid hormone therapy.
A 34-year-old male presented with fulminant hepatitis A associated with acute renal failure. The patient was admitted four days after flu-like symptoms developed. Physical examination was unremarkable except for icteric sclerae. Laboratory studies showed SGOT 10719 U/l, SGPT 5780 U/l, prothrombin time 22%, BUN 25.5 mg/dl, and creatinine 2 mg/dl. Serum complements were within normal ranges, and circulating immune complexes were not detected. Anti-HAV IgM was positive. He developed hepatic coma on the fourth hospital day, and his renal function deteriorated progressively. He was treated with hemodialysis, but there was no improvement in consciousness. Although acute liver failure improved, he died on the 74th hospital day of subendocardial infarction. Autopsy examination showed acute renal tubular necrosis. The liver was enlarged and was in the residual stage of acute hepatitis without submassive necrosis. The development of fulminant hepatitis in hepatitis A has been rare, but in recent years acute renal failure in hepatitis A has been reported. Although the mechanisms responsible for renal failure in liver diseases are uncertain but could be multifactorial, immune complex-mediated nephritis and/or endotoxemia have been considered.
Cyclic GMP generation, induced by preganglionic nerve stimulation or by high extracellular potassium ion concentration (70 mM) in the medium, was studied during aerobic incubation of the excised superior cervical sympathetic ganglion of the rat with and without axotomy, and the results were compared with that of preganglionic denervation. Both axotomy and denervation of the ganglion for a week caused complete loss of increase of cyclic GMP content in the ganglion in response to the preganglionic nerve stimulation. However, the increase of the ganglionic cyclic GMP content evoked by raising the extracellular potassium ion concentration was maintained at a level about two-thirds of the control after axotomy for 1-4 days, while it was abolished within a day after denervation. Ganglionic choline acetyltransferase activity was maintained for several days after axotomy, but it was decreased rapidly by denervation. Acetylcholinesterase, dopamine-beta-hydroxylase and muscarinic cholinergic receptor sites had been lost almost completely a week after axotomy. These results suggest that the increase of ganglionic cyclic GMP content caused by depolarization with high extracellular K+ is associated with the preganglionic nerve terminals rather than with postganglionic receptor.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Distribution of adenylate cyclase and guanylate cyclase activities in neuronal perikarya and glial cells separated from rat brain, and cellular differences in activation between of adenylate cyclase by NaF and of guanylate cyclase by NaN3 have been studied. Adenylate cyclase activity was higher in the glial cells than in the neuronal fraction, while guanylate cyclase activity was equally detected in both cell fractions. Adenylate cyclase was mainly derived from the particulate fraction of both brain cell homogenates, whereas the major portion of guanylate cyclase activity was found in their soluble rather than in the particulate fractions. Although bulk-separated neurons and glial cells almost failed to change intracellular cyclic nucleotide levels in response to some putative neurotransmitters, activation of adenylate cyclase by NaF was found to be greater in neuronal than in glial cell fractions, and was observed more clearly in the soluble than in the particulate fractions. Sodium azide greatly increased guanylate cyclase in the particulate fraction, but did not affect it considerably in the soluble one. Addition of catalase to the reaction mixture together with NaN3 further stimulated guanylate cyclase both int he soluble and the particulate fractions. These results suggest that adenylate cyclase and guanylate cyclase without intimate coupling to the transmitter-receptor system, but with activation by NaF or NaN3, may be distributed ubiquitously in the cells separated from rat cerebral cortex.
Explore the source record for details and available documents.
Explore the source record for details and available documents.