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H Hara

Publications and source records attributed to H Hara.

At least 595 records · Page 33Linked to original sources
PubMed1990

Ca2+/calmodulin-dependent protein kinase II immunoreactivity in the rat hippocampus after forebrain ischemia.

The influence of transient forebrain ischemia on the temporal alteration of Ca2+/calmodulin-dependent kinase II (CaM kinase II) in the rat hippocampus was analysed by the immunohistochemical method using antigen-affinity purified polyclonal antibodies against CaM kinase II of rat brain. Six to twenty-four hours after ischemia, CA1 and CA3 pyramidal cells, and dentate granule cells lost CaM kinase II immunoreactivity in neuronal perikarya, although immunoreactivity in the dendritic fields was preserved. The recovery of immunoreactivity of the CA3 pyramidal cells and dentate granule cells was noted 3 days after recirculation. Seven days after ischemia, immunoreactivity in the CA1 subfield was greatly reduced. These results suggest that CaM kinase II molecules in the CA1 subfield are preferentially located on the CA1 pyramidal cells and that CaM kinase II plays a critical role in the reconstruction of neuronal cytoskeleton and neuronal networks damaged by ischemic insult.

Animals↗
PubMed1990

Malignant lymphoma antigen expressed in nude mouse tumor cells derived from carcinogen-transformed Bloom's syndrome B-lymphoblastoid cell lines.

From nude mouse tumors, in which malignantly transformed Bloom's syndrome (BS) B-lymphoblastoid cell lines were successfully transplanted into s.c. tissues, we have detected strong expression of malignant lymphoma (ML)-associated antigen on the cell surface, by using diluted sera of ML patients and indirect immunofluorescence. Even though carcinogen-treated BS B-lymphoblastoid cell lines expressed various types of cancer antigens (ML, ovarian cancer, stomach cancer, lung cancer, liver cancer, etc.) on the cell membrane as a mixed population (Y. Shiraishi and H. Soma, Proc. Natl. Acad. Sci. USA, 85:8211-8215, 1988), the finding that BS malignant cells originating from nude mouse tumors expressed specific ML-associated antigen seemed significant for ML diagnosis. BS nude mouse tumors were successively transplantable from nude mice to nude mice (100%). Histopathological studies using an electron microscope demonstrated that most tumor cells in s.c. tissues of nude mice were lymphoid malignant cells. Gel electrophoresis and Western blotting analyses demonstrated that the antigen which characterized ML was a single band (Mr 97,000) and did not cross-react with the sera of other cancer patients or with normal sera. Chromosome analysis showed that the cell clones with ML-associated antigen had marker chromosomes involving t(6;?)(p25;?),t(9;?)(q34;?), del(10)(p13),t(12;14)(q24;q11). The expression of ML-associated antigen was also discussed in relation to the marker chromosomes.

Animals↗
PubMed1990

Mechanism of glutathione S-conjugate transport in canalicular and basolateral rat liver plasma membranes.

Transport of S-(2,4-dinitrophenyl)glutathione (DNP-SG), a model compound of glutathione S-conjugates, was studied in purified canalicular and basolateral (i.e. sinusoidal and lateral) rat liver plasma membrane (LPM) vesicles. Incubation of canalicular LPM vesicles with DNP-SG in the presence of ATP resulted in an uptake of DNP-SG into the vesicles. In contrast, in basolateral LPM vesicles the initial rate of ATP-dependent DNP-SG uptake was 3-4-fold lower than that of the canalicular LPM. This suggests that the ATP-dependent glutathione S-conjugates transport is localized in the canalicular membrane of the hepatocytes. The rate of DNP-SG uptake into canalicular LPM vesicles exhibited saturation kinetics with apparent Km values of 4 microM for DNP-SG and 260 microM for ATP. The DNP-SG uptake was inhibited by various glutathione S-conjugates and GSSG, not GSH. The bulkiness of S-substituent alkyl groups in the conjugates and cysteinylglycine of glutathione are essential for the inhibition. In contrast to the ATP-dependent process, the uptake of DNP-SG to basolateral LPM in the presence of KCl was 4-fold higher than that of canalicular LPM. The rate of DNP-SG uptake was enhanced by a valinomycin-induced K+ diffusion potential, and was inhibited by GSH. These results suggest that electrogenic transport of glutathione S-conjugates is localized in the basolateral membrane of the hepatocytes. These studies provide evidence that the ATP-dependent canalicular transport system functions in biliary secretion of glutathione S-conjugates.

Adenosine Triphosphate↗
PubMed1990

The effect of taurine on age-related immune decline in mice: the effect of taurine on T cell and B cell proliferative response under costimulation with ionomycin and phorbol myristate acetate.

Proliferative responses to the costimulation with phorbol-12-myristate-13-acetate (PMA) and suboptimal doses of ionomycin in the purified T and B cells from old mice were lower than those from young mice. The degree of the age-related decline was more significant in T cells than in B cells. Taurine, a sulfur containing amino acid, augmented the proliferative responses of T cells from both young and old mice. The augmentation of the proliferative response by taurine was more marked in old T cells than in young ones. The concentration of intracellular free calcium ion ([Ca2+]i) was significantly lower in the old T cells under the stimulation with PMA and ionomycin than that in the young ones. In the presence of taurine, the concentration of [Ca2+]i in the old T cell significantly increased under the stimulation. The results indicate that taurine improved the proliferative response of old T cells by the restoration of the increment of the concentration of [Ca2+]i under the stimulation.

Aging↗
PubMed1990

Protective effect of alpha-tocopherol on ischemic neuronal damage in the gerbil hippocampus.

The effect of alpha-tocopherol (vitamin E) on ischemic neuronal damage was studied in the gerbil. The animals were subjected to 5 min of cerebral ischemia by bilateral common carotid artery occlusion. Immediately after ischemia, alpha-tocopherol at a dose of 50 or 100 mg/kg was administered intravenously. Morphological changes in the CA1 sector of the hippocampus were evaluated after 7 days of survival. alpha-Tocopherol prevented ischemia-induced neuronal death. The average density of CA1 pyramidal neurons (cells/mm, mean +/- S.E.M.) was 252 +/- 8 (n = 8) in the sham-operated group, 50 +/- 20 (n = 8) in the ischemia group, and 140 +/- 35 (n = 8) and 182 +/- 36 (n = 8) in the groups treated with alpha-tocopherol at the doses of 50 and 100 mg/kg, respectively. The results suggest that free radical scavenging action of alpha-tocopherol played an important role in preventing the neuronal death.

Animals↗
PubMed1990

The anticancer effect of antineoplaston A-10 on human breast cancer serially transplanted to athymic mice.

We report the effects of Antineoplaston A-10 Injection on the growth curve of human breast cancer (R-27) serially transplanted to athymic mice. The intraperitoneal administration of 1/4 LD-50 (50 mg/mouse) of Antineoplaston A-10 Injection every day and 1/2 LD-50 (100 mg/mouse) every other day for 35 days was found to significantly inhibit the growth curve and also the 3H-TdR uptake was inhibited by 73.7% in those given 1/4 LD-50 and by 77.1% in those given 1/2 LD-50. The tumor histology in both groups showed necrosis but no lymphocyte infiltration.

Animals↗
PubMed1990

Synergistic potentiation of in vivo antitumor activity of anti-human T-leukemia immunotoxins by recombinant alpha-interferon and daunorubicin.

In the present study, immunotoxins (ITs) containing ricin A chain (RA) and anti-human T leukemia monoclonal antibodies SN1 and SN2 were used with or without alpha-interferon (IFN) and/or daunorubicin (DNR) for in vivo tumor suppression. SN1 and SN2 are directed toward two unique human T-leukemia-associated cell surface antigens, TALLA and GP37, respectively. As the tumor model, we used nude mice bearing ascitic tumors of Ichikawa, a human T acute lymphoblastic leukemia cell line. In initial studies, we investigated the effect of the IT injection schedule on the efficacy of ITs in the in vivo suppression of the ascitic tumors. Four doses of 20 micrograms each of SN1-RA and SN2-RA completely suppress the tumor growth in 100% of the treated mice when the IT treatment is initiated either 1 or 2 days after tumor inoculation of 1.6 x 10(7) Ichikawa cells into the mice. Subsequently, we investigated the potentiating effects of IFN and DNR on the in vivo antitumor activity of ITs. To this end, we chose to initiate the treatment 4 days after the tumor inoculation when IT treatment alone is only partially effective. ITs (10 micrograms each of SN1-RA and SN2-RA) plus IFN (2 x 10(5) IU) or ITs plus IFN plus DNR (5 micrograms) completely suppress tumor growth in 100% of the treated mice while similar treatment with any one of the three agents is only partially effective. Similar treatment with ITs plus DNR or IFN plus DNR results in complete suppression of tumor growth in 80% of the treated mice. These results were reproducible in a repeated experiment. To gain information about the mechanisms involving the IFN potentiation of IT activity, we carried out several experiments. The cell surface expression of TALLA and GP37 was slightly augmented by the in vitro incubation of Ichikawa cells with IFN as measured by fluorescence-activated cell sorter analysis. The degree of the increase in either TALLA or GP37 was significantly smaller than that of HLA class I antigens in the same experiment. In in vitro experiments, IFN did not show any significant cytotoxic activity against Ichikawa cells or augment the cytotoxic activity of ITs against Ichikawa cells. On the other hand, injections of IFN into nude mice augmented activity of macrophages and NK cells; however, Ichikawa leukemia cells were rather resistant to the NK cell lysis.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1990

Human G-CSF produced by adherent cells in the presence of human recombinant GM-CSF.

Adherent cells (AdCs) in blood from normal volunteers produced granulocyte-macrophage (GM) colony-stimulating activity (CSA) in the presence of 10 ng/ml of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) in vitro. GM-CSA produced by adherent cells in the presence of GM-CSF reached a plateau level on day 6. Colonies stimulated by adherent cell-conditioned medium (AdC-CM-GM-CSF), which had been harvested after 6 days of incubation of AdCs with rhGM-CSF, were granulocyte predominant. When phagocyte-depleted marrow mononuclear cells (PD-M-MNCs) were cultured with AdC-CM-GM-CSF and anti-rabbit serum against rhGM-CSF, 99% of the colonies on day 7 were exclusively composed of neutrophils. When 2 X 10(4) PD-M-MNCs were cultured in a medium containing AdC-CM-GM-CSF, AdC-CM-GM-CSF + anti-GM-CSF, AdC-CM-GM-CSF + anti-G-CSF, or AdC-CM-GM-CSF + both of the anti-bodies, the PD-M-MNCs formed (mean +/- SD) 100 +/- 2.0%, 64.3 +/- 2.5%, 38.6 +/- 0.4%, and 6.0 +/- 0.4% GM colonies, respectively. Furthermore, northern blot analysis revealed that AdCs incubated with 10 ng/ml of rhGM-CSF for 6 h expressed much more mRNA of G-CSF than those without the CSF. These data indicated that AdCs in blood produce G-CSF in the presence of GM-CSF.

Blotting, Northern↗
PubMed1990

Nimodipine attenuates both ischaemia-induced brain oedema and mortality in a rat novel transient middle cerebral artery occlusion model.

A novel transient middle cerebral artery (MCA) occlusion model in rats was used to evaluate the effects of nimodipine on 45Ca accumulation, brain oedema and mortality. Nimodipine (1 microgram/kg/min, IV, 30 min) administered immediately after 3 hr of transient unilateral MCA occlusion significantly attenuated the post-ischaemic increase of tissue water content, partly 45Ca accumulation in the parietotemporal and frontal cortices ipsilateral to the left MCA occlusion 3 hr after reperfusion. Nimodipine decreased the mortality rate at 6 and 9 hr time points after recirculation, although the survival rate at the 24 hr point after recirculation was not different from the control group. These results suggest that nimodipine has beneficial effects in the early phase of reperfusion period.

Animals↗
PubMed1990

Cranioplasty with a frozen and autoclaved bone flap.

27 cases of cranioplasty with autogenous bone grafts stored in a deep-freezer and autoclaved before use are reported. The results of follow-up for an average period of one year were satisfactory from the standpoint of brain protection and cosmetic reconstruction. A small area of absorption of grafted bone was observed in two cases on the follow-up skull roentgenograms. No serious complications were seen except in one case, whose bone flap had to be removed due to an epidural abscess. Experiments revealed that deep-freezing and autoclaving had only minimal effects on bone structure, although osteocytes degenerated. Autogenous bone flap after deep-freezing is a useful material for cranioplasty but sterilization before use is indispensable. Autoclaving is a simple method for sterilization of the flap, available in any operating theatre. It does not increase the risk of postoperative complications such as infection or absorption.

Adult↗
PubMed1990

Electron microscopic localization of acridine orange chromatin interaction products in rat pheochromocytoma PC12 cells.

The purpose of the present study is to examine the distribution pattern of acridine orange (AO) binding to DNA in rat adrenal pheochromocytoma PC12 cells that respond to nerve growth factor (NGF). PC12 cells were incubated in a medium containing 100 ng/ml of NGF for 1-14 days for AO ultracytochemistry. Electron microscopic studies revealed that AO binds to DNA exclusively within the euchromatin portion of the cell nucleus. About 35% of the untreated PC12 cells showed characteristic electron-dense interaction products within the nuclei. The average numbers of AO chromatin interaction products per cell nucleus and per micron 2 nuclear area were 45 and 1.6, respectively. In the presence of NGF, cell proliferation was suppressed. The cells gradually extend neurite-like cell processes. Mean 3H-labeling index was 40.0 +/- 2.2% in untreated cells and 13.0 +/- 2.3% in PC12 cells with NGF for 6 days after incubation for 30 min. With increasing the cellular differentiation percentages of AO positive cells and average numbers of AO chromatin interaction products per cell nucleus and per micron 2 nuclear area showed a progressive decrease. The results of the present and previous studies suggest that AO chromatin interaction products may be indicative of cell proliferation and differentiation.

Acridine Orange↗
PubMed1990

Distribution pattern of acridine orange chromatin interaction products in rat glioma C6 cells at different phases of the cell cycle.

The purpose of the present study was to examine the distribution pattern of electron-dense acridine orange (AO) chromatin interaction products in rat glioma C6 cells at different phases of the cell cycle. For synchronization in the early S-phase the cells in logarithmic growth were treated with 3 micrograms/ml aphidicolin, a specific inhibitor of DNA polymerase alpha and then cultured in normal medium. For synchronization in the M-phase the cells cultured with aphidicolin and then returned to normal medium were treated with 0.05 micrograms/ml colcemid. Histoautoradiographic analysis of the C6 cells using the pulse chase method demonstrated approximately 16 h of cell cycle time and about 6.5 h of S-phase. Ultracytochemically, AO chromatin interaction products were found in all phases of the cell cycle except for the mitotic phase, namely in G1, S, and G2. The highest percentage of AO chromatin interaction products was observed in the early S-phase and the lowest in the G2 phase. The mean number of AO chromatin interaction products per nuclear area increased in the course of S-phase parallel with an increase of 3H-uridine uptake during the S-phase. The results show a characteristic distribution pattern of AO label specific for each of the four stages of the cell cycle, however, the significance of the coincident RNA synthetic activity remains to be elucidated.

Acridine Orange↗
PubMed1990

Syntheses and platelet aggregation inhibitory and antithrombotic properties of [2-[(omega-aminoalkoxy)phenyl]ethyl]benzenes.

A series of [2-[(omega-aminoalkoxy)phenyl]ethyl]benzene derivatives were synthesized and evaluated for their ability to inhibit collagen-induced platelet aggregation in vitro and to protect experimental thrombosis in mice. The results showed that the compounds were in vitro inhibitors of collagen-induced platelet aggregation. Most of them were also effective in the mouse antithrombotic assay. The compounds were found to be potent antagonists to S2 serotonergic receptor, and good correlation (r = 0.85) between their S2 serotonergic receptor antagonism and their potency as platelet antiaggregatory drugs was observed. Among the compounds studied, mono[2-(dimethylamino)-1-[[2-[2-(3- methoxyphenyl)ethyl]phenoxy]methyl]ethyl] succinate hydrochloride (12b, MCI-9042) was selected for further pharmacological and toxicological evaluation.

Animals↗
PubMed1990

Staurosporine, a novel protein kinase C inhibitor, prevents postischemic neuronal damage in the gerbil and rat.

The protective effects of protein kinase inhibitors and a calmodulin kinase inhibitor (W-7) against ischemic neuronal damage were examined in the CA1 subfield of the hippocampus. Staurosporine, KT5720, and KT5822 were used as inhibitors of protein kinase C (PKC), cyclic AMP-dependent protein kinase, and cyclic GMP-dependent protein kinase, respectively. All test compounds were injected topically into the CA1 subfield of the hippocampus. In the gerbil ischemia model, staurosporine (0.1-10 ng) administered 30 min before ischemia prevented neuronal damage in a dose-dependent manner. However, KT5720, KT5822, and W-7 were ineffective, even at a dose of 10 ng. In the rat ischemia model, staurosporine (10 ng) also prevented neuronal damage when administered before ischemic insult, although staurosporine administered 10 or 180 min after recirculation was ineffective. These results suggest the involvement of PKC in CA1 pyramidal cell death after ischemia and that the fate of vulnerable CA1 pyramidal cells through PKC-mediated processes could be determined during the early recirculation period.

Alkaloids↗
PubMed1990

Characterization of a 70Z/3 pre-B cell derived macrophage clone. Differential expression of Hox family genes.

An adherent cell line was established from the much studied pre-B cell line 70Z/3. The adherent cell line had the morphological features of a macrophage and stained positive for non-specific esterase. In addition, this line expressed high levels of RNA for the macrophage specific enzyme, lysozyme. Although the 70Z/3 macrophage variant has lost the ability to respond to lipopolysaccharide and interferon-gamma by expressing RNA transcripts for immunoglobulin light chain, it exhibited a new response characterized by increased levels of I-A RNA transcripts. Both the pre-B and macrophage variants also expressed RNA transcripts which hybridize to a Hox 2.3 probe. In contrast, transcripts which hybridize to Hox 1.1, 2.1, and 6.1 probes are expressed in the pre-B line but could not be detected in the macrophage.

Animals↗
PubMed1990

Cloning and nucleotide sequence of the ispA gene responsible for farnesyl diphosphate synthase activity in Escherichia coli.

The molecular cloning and the determination of the nucleotide sequence of the ispA gene responsible for farnesyl diphosphate (FPP) synthase [EC 2.5.1.1] activity in Escherichia coli are described. E. coli ispA strains have temperature-sensitive FPP synthase, and the defective gene is located at about min 10 on the chromosome. The wild-type ispA gene was subcloned from a lambda phage clone containing the chromosomal fragment around min 10, picked up from the aligned genomic library of Kohara et al. [Kohara, Y., Akiyama, K., & Isono, K. (1987) Cell 50, 495-508]. The cloned gene was identified as the ispA gene by the recovery and amplification of FPP synthase activity in an ispA strain. A 1,452-nucleotide sequence of the cloned fragment was determined. This sequence specifies two open reading frames, ORF-1 and ORF-2, encoding proteins with the expected molecular weights of 8,951 and 32,158, respectively. A part of the deduced amino acid sequence of ORF-2 showed similarity to the sequences of eucaryotic FPP synthases and of crtE product of a photosynthetic bacterium. The plasmid carrying ORF-2 downstream of the lac promoter complemented the defect of FPP synthase activity of the ispA mutant, showing that the product encoded by ORF-2 is the ispA product. The maxicell analysis indicated that a protein of molecular weight 36,000, approximately consistent with the molecular weight of the deduced ORF-2-encoded protein, is the gene product.

Alkyl and Aryl Transferases↗