Narumi S | Sebelas Maret University (original) (raw)

Papers by Narumi S

Journal of …, 1978

Addition of norepinephrine or isoproterenol to primary cultures started from the brains of 1-3 da... more Addition of norepinephrine or isoproterenol to primary cultures started from the brains of 1-3 day old rats caused up to 200-fold increases in cAMP levels, which reached a maximum by 5-10 min and then declined. This effect was studied in detail for norepinephrine. The rise in cAMP levels was followed by morphological changes, in which up to 65% of the cells exhibited an astrocyte-like morphology, and 2-3 fold increases in carbonic anhydrase and (Na+-K+) ATPase activities. However, morphological transformation also occurred after much smaller increases in total cAMP levels. These effects on cell morphology and enzyme activities reached a maximum 1-2 h after addition of norepinephrine and then declined. Carbonic anhydrase activity was found both in the particulate and post 100,000 g supernatant fractions from homogenates of these cultured cells, and in the latter case the activity was activated 3-fold by addition of cAMP. The significance of these obscrvations on the cellular localization of, and functional role for similar increases in cAMP in brain tissue is discussed.

Journal of leukocyte …, 1992

The American journal …, 1993

... Remote Control - Recording to Storage Devices (Voice, Video, etc.) ... more sophisticated and... more ... Remote Control - Recording to Storage Devices (Voice, Video, etc.) ... more sophisticated and high-gain diversity schemes such as soft-decision combining, which Educe the required value and increase the cell radius and system capacity. ... 6 Cluster-cellular radio access network. ...

Brain Research, 1987

Memory impairment in rats with lesions of the basal forebrain (BF) and medial septal nucleus (MS)... more Memory impairment in rats with lesions of the basal forebrain (BF) and medial septal nucleus (MS) including cell bodies of the cortical and septohippocampal cholinergic systems, respectively, were compared in order to evaluate the functional contribution of the two cholinergic systems to memory. Biochemical assay revealed that lesioning of the BF and MS resulted in marked and selective decreases in both choline acetyltransferase and acetylcholinesterase activities in the cerebral cortex and hippocampus, respectively. Rats with BF lesions exhibited a severe deficit in a passive avoidance task; acquisition of passive avoidance by repeated training was sluggish, and the acquired response was rapidly eliminated in a subsequent extinction test. However, only slight impairment of passive avoidance was observed in rats with MS lesions. Memory impairment in rats with BF or MS lesions was also investigated using two spatial localization tasks, the Morris water task and the 8-arm radial maze task. Both BF and MS lesions elicited a significant impairment in the Morris water task that required reference memory, as demonstrated by an apparent increase in the latency to escape onto a hidden platform in a large water tank. The impairment was much more obvious in the BF-lesioned rats. In contrast, in the radial maze task primarily requiring working memory, rats with lesions of the MS showed severe disruption, exhibiting a marked increase in total errors, a decrease in the number of initial correct responses, and an apparent change in the strategy pattern. However, corresponding changes in the rats with BF lesions were slight. These results suggest that BF lesions may lead to substantial long-term memory impairment while MS lesions may primarily produce short-term or working memory impairm3nt, indicating a qualitatively different contribution of the two cholinergic systems to memory. It is also suggested that these two experimental animal models may be useful for evaluation of therapeutic drugs for senile dementia of the Alzheimer type.

Science, 1996

... events are similar on both sides of the arc, (ii) events deeper than 300 km are unob-servable... more ... events are similar on both sides of the arc, (ii) events deeper than 300 km are unob-servable at OBSs in the rift zone, and(iii) along-arc ray paths are attenuated through-out the rift zone (Fig. 3) (14, 15). Although these observations ...

IEEE Journal on Selected Areas in Communications, 1997

Since code-division multiple-access (CDMA) capacity is interference limited, call admission contr... more Since code-division multiple-access (CDMA) capacity is interference limited, call admission control (CAC) must guarantee both a grade of service (GoS), i.e., the blocking rate, and a quality of service (QoS), i.e., the loss probability of communication quality. This paper describes the development of a new capacity design method based on these two concepts. Theoretical expressions for GoS and QoS as functions of traffic intensity and CAC thresholds are first derived from the traffic theory viewpoint, and then a design method using these expressions is presented. At that time, two strategies for CAC are assumed. One is based on the number of users, and the other is based on the interference level. Computer simulation results are presented that strongly support the proposed design method. Furthermore, numerical examples and a performance comparison of the two strategies considering various propagation parameters, nonuniform traffic distributions, and various transmission rates are shown

The journal of …, 1997

Chemokines such as IFN-inducible protein-10 (IP-10) and JE/monocyte chemotactic protein-1 (MCP-1)... more Chemokines such as IFN-inducible protein-10 (IP-10) and JE/monocyte chemotactic protein-1 (MCP-1) are induced in the murine liver in a tissue-specific manner. We examined whether IP-10 and MCP-1 are pathologically involved in chronic hepatitis. Whereas the serum levels of IP-10 and MCP-1 in patients with chronic persistent hepatitis C were elevated compared with those in normal volunteers, both chemokine levels were further significantly higher in patients with the active form (chronic active hepatitis (CAH)). The elevated IP-10 level was not a general phenomenon of inflammation, because it was not seen in patients with rheumatoid arthritis, whereas MCP-1 levels were elevated to the same extent in both patient groups. Better responsiveness to IFN therapy in CAH was related to lesser grades of necroinflammatory activity and was predicted by the lower IP-10 and higher MCP-1 levels. IP-10 levels in patients cured by IFN therapy decreased to the levels in normal volunteers, while the MCP-1 levels only slightly decreased. Serum levels of both chemokines in patients who were not cured remained unchanged after IFN therapy. In situ hybridization analysis of CAH revealed that IP-10 mRNA was expressed mainly in hepatocytes around intralobular focal and periportal piecemeal necrosis, while some MCP-1 mRNA was expressed in some sinusoidal cells. These results suggested that IP-10 plays a specific role in the intralobular accumulation of mononuclear cells and/or the death of hepatocytes in chronic hepatitis.

Journal of Biological Chemistry, 1990

Free Radical Biology and Medicine, 1999

Lipid hydroperoxide (LOOH)–dependent lipid peroxidation was induced in α-linolenic acid (LNA)-loa... more Lipid hydroperoxide (LOOH)–dependent lipid peroxidation was induced in α-linolenic acid (LNA)-loaded hepatocytes by adding Fe, Cu, V, or Cd ions at concentrations from 20 to 500 μM. The effects of structurally related flavonoids at concentrations from 10 to 500 μM on the lipid peroxidation were examined. The results with regard to each flavonoid subclass are as follows: (i) Flavonols such as myricetin, quercetin, fisetin, and kaempferol, but not morin, showed dose-dependent antioxidative activity against metal-induced lipid peroxidation at all metal concentrations. Myricetin, quercetin, and fisetin were the most effective antioxidants, although their efficacies depended on the metal ion. Kaempferol and morin had antioxidative activity equal to the other flavonols in the presence of Cu ions, but were much less effective for the other three metal ions. (ii) Flavones, luteolin, apigenin, and chrysin were antioxidative at low Fe concentrations, but were pro-oxidative at high Fe concentrations. Luteolin exhibited antioxidative activity similar to that of catechol-containing flavonols in the presence of the other three metal ions. Apigenin and chrysin also acted as pro-oxidants with V or with all metal ions, respectively. (iii) Taxifolin, a flavanone, also showed both anti- and prooxidative activity, depending on Fe concentrations, but with other metal showed only antioxidative activity ions. (iv) Epigallocatechin, a flavanol, was antioxidative with all metal ions, and its activity was similar to that of catechol-containing flavonols. The various effects of flavonoids on metal-induced lipid peroxidation in LNA-loaded hepatocytes is discussed with regard to the change in redox potential of flavonoid–metal complexes.

Cell, 2004

Although germline cells can form multipotential embryonic stem (ES)/embryonic germ (EG) cells, th... more Although germline cells can form multipotential embryonic stem (ES)/embryonic germ (EG) cells, these cells can be derived only from embryonic tissues, and such multipotent cells have not been available from neonatal gonads. Here we report the successful establishment of ES-like cells from neonatal mouse testis. These ES-like cells were phenotypically similar to ES/EG cells except in their genomic imprinting pattern. They differentiated into various types of somatic cells in vitro under conditions used to induce the differentiation of ES cells and produced teratomas after inoculation into mice. Furthermore, these ES-like cells formed germline chimeras when injected into blastocysts. Thus, the capacity to form multipotent cells persists in neonatal testis. The ability to derive multipotential stem cells from the neonatal testis has important implications for germ cell biology and opens the possibility of using these cells for biotechnology and medicine.

Abstract Built-in self-test (BIST) has been applied to test an analog to digital converter (ADC) ... more Abstract Built-in self-test (BIST) has been applied to test an analog to digital converter (ADC) and a digital to analog converter (DAC) embedded in a DSP-core ASIC. The performance characteristics of the ADC and the DAC designed in according with the CCITl' recommendations are ...

Hepatology, 1995

The clinical course of 37 patients who underwent 46 liver transplantations for primary (n = 33) a... more The clinical course of 37 patients who underwent 46 liver transplantations for primary (n = 33) and secondary (n = 4) sclerosing cholangitis was reviewed. The median follow-up was 37 months. The patient and graft survivals for patients with primary sclerosing cholangitis at 1, 2, and 5 years were 96.9%, 91.6%, 87.9%, and 83.1%, 74.2%, 65.2%, respectively. In the patients with primary sclerosing cholangitis (PSC), prior surgery except for simple cholecystectomy was associated with significantly greater operative time and blood loss. No cholangiocarcinoma was identified at the time of transplantation. Human leukocyte antigen typing for PSC patients was heavily weighed toward B8 (58.8%) compared with control (11.8%). Sixty-two percent of patients with PSC also had inflammatory bowel disease. Moderate or severe rejection requiring OKT3, “rescue therapy” with FK506, or retransplantation was relatively higher in patients with inflammatory bowel disease (70%) versus patients without inflammatory bowel disease (36.4%) and a matched control group (37.5%). Progressive inflammatory bowel disease was seen in 6 of 19 patients, with 3 developing cancer and a dysplasia. Two patients in the entire group died of sepsis and 3 of colon cancer (2 recurrent and 1 primary). These data demonstrate that excellent survival results can be achieved in this group of patients. Rejection is frequent and often severe and steroid refractory. Colon cancer represents the most frequent cause of death in PSC patients after liver transplantation and demands constant attention.

Brain research, 1978

The development of (Na++K+) ATPase, carbonic anhydrase and HCO3−-stimulated ATPase activity was s... more The development of (Na++K+) ATPase, carbonic anhydrase and HCO3−-stimulated ATPase activity was studied in developing rat brain in vivo, and in primary astrocyte cultures from 1–3-day-old rat brain as a function of increasing cell growth. The primary cultures showed an increase in all the above enzyme activities during cell growth, with time courses which were qualitatively similar to their development in vivo. Cell cultures grown separately from the cerebellum plus brain stem regions showed greater carbonic anhydrase activity than cerebral cultures over the entire 4-week growth period, correspondincg to development of this activity in these same regions in vivo. HCO3−-stimulated ATPase activity was slightly greater in cerebellar cultures and (Na++K+) ATPase activity was greater in cerebral cultures up to the second week of growth, resembling development of the same enzyme activities in vivo. C6 glioma and neuroblastoma cells showed no and 10-fold lower carbonic anhydrase activities respectively, compared to the primary astrocyte cultures.Addition of 1 mMN6-2′-O-dibutyryladenosine-3′,5′-monophosphate (DBcAMP) in the presence of serum caused marked formation of cellular processes and increased carbonic anhydrase and (Na++K+) ATPase activity. Maximum effects were found 2 h after addition of 1 mM DBcAMP and thereafter declined. In the absence of serum such effects persisted for at least 24 h. Electron microscope studies showed large numbers of microtubule (≈ 20 nm diameter) and filamentous structures (⪕10nm diameter) in the cytoplasm, which showed changes in distribution in cells treated with DBcAMP.This study suggests that the increase in ATPase and carbonic anhydrase activities in rat brain with increasing age may be in part a reflection of proliferation and development of astroglia cells. Together with the morphological data, it also provides additional evidence that primary cultures derived from neonatal rats may closely resemble developing astroglia in vivo.