AQ-0145, a newly developed histamine H3 antagonist, decreased seizure susceptibility of electrically induced convulsions in mice

We studied the effect of AQ-0145, a newly developed histamine H3-receptor antagonist, on electrically induced convulsions in mice. AQ-0145 significantly decreased the durations of each convulsive phase. The anticonvulsant effect of AQ-0145 was antagonized by mepyramine (pyrilamine) and ketotifen, centrally acting histamine H1-receptor antagonists. Thus, the blockade by histamine H1 antagonists of the AQ-0145-induced decrease in seizure susceptibility indicated that histamine released by AQ-0145 from the histaminergic nerve terminals interacts with the histamine H1 receptors of postsynaptic neurons. These findings fully support the hypothesis that the central histaminergic neuronal system is involved in the inhibition of seizures. It is suggested that the neuropharmacological data on histamine H3 ligands may provide clinical candidates for the CNS disorders in which histamine plays important roles in mental and behavioral functions. In this study, it was suggested that AQ-0145 was a new clinical candidate of H3 ligands.

[Pneumonitis in a patient who inhaled a fibrinolysin-deoxyribonuclease mixture]

A 56-year-old man was transferred to our department from the department of oral surgery, with a high fever and a cough. He had inhaled a fibrinolysin-deoxyribonuclease mixture (Elase) to treat inflammation in the oral cavity after resection of an oral tumor. A chest X-ray film showed diffuse patchy shadows in both lung fields. Bronchoalveolar lavage fluid had an abnormally high number of lymphocytes and transbronchial lung biopsy revealed interstitial infiltration by lymphocytes and histiocytes, with granulomatous lesions. The patient was treated with steroids, and his clinical condition improved markedly. He accidentally inhaled the drug again, and the coughing and fever began again. The drug lymphocyte stimulation test was positive only for the fibrinolysin-deoxyribonuclease mixture. Based on these findings, we diagnosed pneumonitis induced by this fibrinolysin-deoxyribonuclease mixture. To our knowledge, this is the first reported case of pneumonitis caused by this fibrinolysin-doxyribonuclease mixture.

Effects of thioperamide, a histamine H3-receptor antagonist, on a scopolamine-induced learning deficit using an elevated plus-maze test in mice

We examined the effects of thioperamide and (R)-alpha-methylhistamine, a histamine H3-receptor antagonist and an agonist, respectively, on a scopolamine-induced learning deficit using an elevated plus-maze test in mice. Thioperamide alone slightly improved the learning deficit induced by scopolamine, and pretreatment with zolantidine, a histamine H2-receptor antagonist, significantly enhanced the effect of thioperamide in this test. (R)-alpha-Methylhistamine, pyrilamine, ketotifen, terfenadine, and zolantidine alone at the doses tested had no effect. Moreover, the improvement by thioperamide plus zolantidine was antagonized by pretreatment with histamine H1-receptor antagonists such as pyrilamine or ketotifen, but not by terfenadine. Thus, thioperamide improved the scopolamine-induced learning deficit through central histamine H1 receptors in mice. The present results supported the hypothesis that histamine may play an important role in learning and memory.

Isolation and characterization of a yeast gene, MPD1, the overexpression of which suppresses inviability caused by protein disulfide isomerase depletion

MPD1, a yeast gene the overexpression of which suppresses the inviability caused by the loss of protein disulfide isomerase (PDI) was isolated and characterized. The MPD1 gene product retained a single disulfide isomerase active site sequence (APWCGHCK), an N-terminal putative signal sequence, and a C-terminal endoplasmic reticulum (ER) retention signal, and was a novel member of the PDI family. The gene product, identified in yeast extract, contained core size carbohydrates. MPD1 was not essential for growth, but overexpression of the gene suppressed the maturation defect of carboxypeptidase Y caused by PDI1 deletion, indicative of the related function to PDI in the yeast ER.

The crystal structure of thermostable mutants of chimeric 3-isopropylmalate dehydrogenase, 2T2M6T

A chimeric 3-isopropylmalate dehydrogenase (IPMDH), 2T2M6T, was produced by replacing the amino acid sequences of the Thermus thermophilus enzyme with those of the Bacillus subtilis enzyme from residues 75 to 113. Decreased thermostability of the chimeric enzyme was recovered by either evolutionary engineering (I93L) or site-directed mutagenesis (S82R). The 3-D structures of the mutants have been determined by X-ray diffraction at 2.1 A resolution. Although S82R was refined routinely, I93L required the preliminary rigid-body refinement of each domain. The R-factors were reduced to 0.18 for both mutants. Removal of the unfavorable torsion angle at isoleucine 93 may have made I93L more thermostable than 2T2M6T. In the case of S82R, the replaced arginine residue contributed to the extra hydrogen bond with water molecules. The large replaced residue decreased the entropy of the solvent, which may have caused the improvement in enzyme thermostability. Denaturation by heating may be interpreted from these structural results.

The immuno-stimulant OK-432 enhances liver regeneration after 70% hepatectomy

The effect of reticuloendothelial system activation on hepatic regeneration after 70% hepatectomy was investigated. OK-432, a killed streptococcal preparation which increases reticuloendothelial system function, was administered to rats prior to 70% hepatectomy. Hepatic incorporation of 3H-thymidine 24 h after 70% hepatectomy was enhanced by OK-432 pretreatment. DNA synthesis was greater in pretreated than in control rats and correlated highly with reticuloendothelial system phagocytic activity prior to surgery. Methyl palmitate, which decreases reticuloendothelial system function, was administered to rats prior to 70% hepatectemy. Hepatic incorporation of 3H-thymidine 24 h after 70% hepatoctomy was significantly depressed by methylpalmitate-pretreatment. These data suggest that reticuloendothelial system plays a role in liver regeneration and that hepatocyte proliferation might be enhanced by protection from surgical stress and endotoxins with reticuloendothelial system stimulation by OK-432.

[Hepatocellular transplantation in rats with congenital ascorbic acid deficiency]

The purpose of this study was to investigate suitable sites for hepatocyte transplantation in rats with congenital liver enzyme deficiency. Hepatocytes were isolated from ODS-(+)/+ rats, which are congenic to ODS-od/od rats and have hepatic L-gulonolactone oxidase. A total of 1 x 10(7), 1 x 10(7), and 2.5 x 10(6) hepatocytes were respectively transplanted into the peritoneal cavity, spleen, or portal vein of ODS-od/od rats, which are unable to synthesize ascorbic acid (AsA) due to lack of hepatic L-gulonolactone oxidase. After 4 days of oral pretreatment with 0.05% 2-acetylaminofluorene, recipients underwent 70% partial hepatectomy just before transplantation. AsA administration was discontinued at 6 weeks after transplantation. The symptom-free survival rate and the serum AsA level of recipient rats were determined at 6 weeks after discontinuing AsA administration. The symptom-free survival rate of untransplanted rats and recipient rats with intraperitoneal, intrasplenic and intraportal hepatocyte transplantation were 0%, 0%, 60%, and 100%, respectively. The serum AsA levels were 0.20 +/- 0.20 microgram/ml, 0.14 +/- 0.05 microgram/ml, 1.06 +/- 0.26 microgram/ml, and 1.58 +/- 0.61 microgram/ml, respectively. Intrasplenic or intraportal transplantation was able to cure ODS-od/od rats. A subsequent splenectomy study showed that hepatocytes reaching the liver via the splenic vein following intrasplenic hepatocyte transplantation played a major role in this experimental success.

Production of monoclonal antibodies specific to the carboxyl terminal region of the 85 kDa subunit of phosphatidylinositol 3-kinase: use of the antibodies in recognition of mutant p85

We have established two hybridomas producing mAb to the carboxyl terminal region of phosphatidylinositol-3 kinase 85 kDa subunit type alpha (p85 alpha). Analysis using deletion mutants of p85 revealed that epitopes for the two mAb were located on the border of the src homology 2 (SH2) sequence located at the carboxyl end of p85. They immunoprecipitated free p85 efficiently, but reactivity to p85 bound to p110 was very weak. Together with the mAb which we have reported previously, a panel of mAb that covered the various parts of p85 alpha was obtained. Using this panel, we characterized two mutants of p85 (70 and 50 kDa) expressed in the human colon carcinoma cell line, HCC2998. No wild-type p85 was detected in these cells. A mAb specific to the carboxyl terminal region detected p70 but not p50, suggesting that this region is missing in p50. The panel of mAb is a useful tool to use to analyse mutant forms of p85.

[Possible roles of brain histamine H3 receptors and the pharmacology of its ligands]

The discovery of the presynaptic histamine H3 receptors confirmed the idea that histamine is a neurotransmitter in the mammalian brain. The H3 receptors (autoreceptors) regulate the release and synthesis of histamine. The H3 receptors also modulate the other neurotransmitters (heteroreceptors). Subclasses of H3 antagonist binding sites were found in the brain (H3A and H3B). The regulation of noradrenaline release is reported to be mediated by H3A rather than H3B. The H3 binding site belongs to the class of receptors coupled to G-proteins. Besides the molecular data, this review focuses on the functional roles of H3 receptors in the brain and discusses the possible use of H3 ligands for neurobehavioral disorders. The pharmacological data of H3 ligands may provide clinical candidates for CNS disorders in which histamine plays important roles in mental and behavioral functions. Especially, H3 antagonists may be useful for CNS disorders such as narcolepsy, dementia, epilepsy, and obesity, while H3 agonists may provide for anxiety, insomnia, migraine. However, these suggestions are still preliminary and further clinical research is needed, although potent and safe novel H3 ligands are being developed.

Effects of the histaminergic system on the morphine-induced conditioned place preference in mice

The effects of an H2 receptor antagonist, a histidine decarboxylase inhibitor and a histamine precursor on the morphine-induced place preference in mice were examined. Morphine (1-7 mg/kg) produced a place preference in a dose-dependent manner. This morphine-induced place preference was significantly antagonized by the dopamine (DA) D1 receptor antagonist SCH 23390. The histamine precursor, L-histidine, attenuated the morphine (7 mg/kg)-induced place preference. On the other hand, the histidine decarboxylase inhibitor, alpha-fluoromethylhistidine (alpha-FMH), significantly potentiated the morphine (1 mg/kg)-induced place preference. This potentiation was antagonized by SCH 23390. The H2 receptor antagonist zolantidine (0.3 mg/kg) significantly potentiated the morphine-induced place preference. Surprisingly, zolantidine (1 mg/kg) alone also produced a significant place preference. The zolantidine-induced place preference was antagonized by SCH 23390. In addition, zolantidine (1, 3 and 10 mg/kg) significantly increased DA turnover (DA ratio) in the limbic forebrain (nucleus accumbens and olfactory tubercle), implying that zolantidine may activate the mesolimbic DA system. Moreover, co-administration of zolantidine dose-dependently increased morphine (10 mg/kg)-induced DA turnover in the limbic forebrain. These results suggest that the activation of histaminergic neurons may attenuate the rewarding effect of morphine, while the inhibition of histaminergic neurons may potentiate the rewarding effect of morphine. Furthermore, potentiation of the morphine-induced rewarding effect by inhibition of histaminergic neurons may be mediated by D1 receptors. We also demonstrated that the H2 receptor antagonist zolantidine may activate the mesolimbic DA system, and as a result, zolantidine itself produces a rewarding effect and potentiates the morphine-induced rewarding effect.

Protective effects of soy protein on the peroxidizability of lipoproteins in cerebrovascular diseases

To study the mechanism of dyslipoproteinemia, lipoproteins [very low density lipoprotein (VLDL), low density lipoprotein (LDL) and high density lipoprotein (HDL)] were isolated from stroke patients and healthy persons by ultracentrifugation. Lipoproteins were dialyzed into copper dichloride solution to study the effects of soycreme administration on lipoprotein peroxidation. Blood was drawn from 15 patients with cerebral thrombosis who were not administered soycreme, 10 patients with cerebral thrombosis who were administered soycreme and 11 healthy persons. The lipoproteins were dialyzed into 5 mol/l copper dichloride solution for various lengths of time, and then lipid constituents in the lipoproteins were measured by thin-layer chromatography. After the dialysis, percentages of cholesteryl ester and triglyceride in various lipoproteins decreased significantly (P < 0.05 or 0.01) in both patient groups and in healthy persons. Spot X1 was found between triglyceride and free fatty acid on the thin-layer chromatography, and spot X2 was located between free fatty acid and free cholesterol after dialysis. Spots X1 and X2 reflect lipoprotein peroxidation. Percentages of these spots were higher in VLDL, LDL and HDL in the patient groups than in the healthy subjects. Soycreme administration suppressed the appearance of spots X1 and X2. Furthermore, blood cholesterol concentrations were reduced by the administration of soy protein. Thus, soy may be useful in the prevention and/or treatment of atherosclerosis.

Ameliorating effects of histidine on scopolamine-induced learning deficits using an elevated plus-maze test in mice

We investigated the effects of histidine on scopolamine-induced learning deficits in the elevated plus-maze test in mice. In this test, transfer latency (TL), the time mice took to move from the open arm to the enclosed arm, was used as an index of learning and memory. Intraperitoneal administration of scopolamine (0.5 mg/kg) prolonged the TL on day 2 compared with that in the saline-treated group. Histidine loading (500, 800 and 1600 mg/kg) reversed the prolongation of the TL induced by scopolamine. This ameliorating effect of histidine was abolished by alpha-fluoromethylhistidine, an inhibitor of histidine decarboxylase, suggesting that histidine itself has no such ameliorating effect. Moreover, the ameliorating effect of histidine was antagonized by a histamine H1 receptor antagonist, pyrilamine. However, zolantidine, a histamine H2 receptor antagonist, showed no antagonism of the effect of histidine. Thus, histamine, a decarboxylated product of histidine, elicited an ameliorating effect on scopolamine-induced learning deficit via histamine H1 receptors in mice. These findings clearly indicated that there is a close relationship between histaminergic and cholinergic systems in the brain, and that histamine may play certain important roles in learning and memory.

Purification and characterization of chitin deacetylase from Absidia coerulea

Chitin deacetylase, which releases the acetyl groups of glycol chitin was purified from a fungus, Absidia coerulea, and characterized. The enzyme was purified 516-fold to homogeneity by means of 65-80% ammonium sulfate precipitation followed by chromatography on Butyl Toyoperal-650M, Gigapite (hydroxyapatite), and DEAE Toyopearl-650M. It had an apparent molecular weight of 75 kDa both on sodium dodecyl sulfate polyacrylamide gel electrophoresis and gel filtration chromatography, indicating that the enzyme exists as a monomer. The amino-terminal sequence was determined to be Gly-Glu-Tyr-Trp-Gln-Ser-Phe-. The enzyme is active on chitooligosaccharides with more than two N-acetylglucosamine residues (chitobiose) and is able to convert the nascent chitin synthesized by chitin synthase to chitosan in vitro. When O-hydroxyethylated chitin (glycol chitin) was used as a substrate, the optimum pH for enzyme activity was 5.0 and the optimum temperature was 50 degrees C. The enzyme was heat-stable and strongly inhibited by Fe3+. Furthermore, chitin deacetylase was demonstrated to be localized near the inner face of the cell wall (periplasmic space) in the mycelia by using immunoelectron microscopy.

The crystal structures of mutated 3-isopropylmalate dehydrogenase from Thermus thermophilus HB8 and their relationship to the thermostability of the enzyme

The structures of two mutant forms (G240A and L246E/V249M) of 3-isopropylmalate dehydrogenase from Thermus thermophilus HB8 were studied by X-ray crystallography. In the case of G240A, the replacement of glycine by alanine at residue 240 was expected to decrease the thermostability as a result of abnormal contacts between the methyl group of alanine and the peptide chain. However, the normal van der Waals' contacts were achieved owing to a shift in a bundle of beta-strands that yielded a vacant space for the alanine residue. The extended hydrogen bonds within the beta-sheet are the major reason for the decreased thermostability of G240A. The mutations in L246E/V249M are located in an alpha-helix region which is involved in subunit-subunit contact via hydrophobic interaction. Loosening of the subunit-subunit contact owing to ionic repulsion was the major cause of the lower heat stability of L246E/V249M.

An ultrasonically powered instrument for laparoscopic surgery: a brief technical report of preliminary success

We report the use of an ultrasonically powered instrument (CUSA) for laparoscopic surgery. A total of 105 patients underwent laparoscopic or laparoscopic assisted surgical procedures. Ninety-one laparoscopic cholecystectomies (LC), 9 laparoscopic appendectomies (LA), 3 laparoscopic colon resections (LCR), and 2 laparoscopic partial gastrectomies (LPG) were done using CUSA. In LC, CUSA separates the areolar connective tissue between gallbladder and liver bed without dividing any sizable vessels or injuring the liver. In LA, LCR, and LPG, CUSA makes mesenteric vessel identification and division rapid and safe. We concluded that CUSA is useful for laparoscopic surgery.

Transformation of cultured human monocytes by peroxidized low-density lipoprotein

To study the roles of peroxidized low-density lipoprotein (pox-LDL) during the formation of foam cells from human monocytes, monocytes isolated from normal human blood were incubated with RPMI alone, normal low-density lipoprotein (n-LDL) and copper pox-LDL. The concentrations of total cholesterol (TCH) and lipid peroxide in the human monocyte medium did not change significantly after incubation with RPMI medium alone or n-LDL, but those of TCH decreased slightly after incubation with pox-LDL for 24 h. Triglyceride (TG) concentrations in the culture medium of human monocytes decreased after incubation with all above substances. Ultrastructural studies showed that the monocytes changed to macrophages after incubation with RPMI alone or n-LDL and to foam cells after incubation with pox-LDL for 48 h. We conclude that TGs may be metabolized for ATP production by human monocytes. The energy may play a role in the transformation of monocytes to macrophages, and pox-LDL can induce transformation of monocyte-derived macrophages to foam cells.

Cell-cycle dependent biosynthesis and localization of p53 protein in untransformed human cells

Localization of p53 in human cultured lymphocytes and in cultured skin fibroblasts was studied by immuno-fluorescent microscopy and post-embedded immunoelectron microscopy using Lowicryl K4M. In quiescent lymphocytes, p53 was found in small amounts in both the cytoplasm and the nucleus. p53 in the nucleus was found associated with the non-chromatin structure. At 24 h or 72 h of PHA stimulation, p53 increased markedly just beneath the plasma membrane and in the nucleus, which stained diffusely with anti-p53. In resting fibroblasts, small amounts of p53 were present in both the cytoplasm and the nucleus. After 16 h of stimulation of confluent-resting fibroblasts by trypsinization and replating, a phase just prior to the initiation of DNA synthesis, p53 slightly increased in both the cytoplasm and the nucleus. Afterwards, p53 was present predominantly in the cytoplasm, closely associated with the cytoskeletal actin filaments. In mitotic cells, p53 was distributed throughout the cytoplasm. When fibroblasts were extracted with saponin, p53 was still associated with the actin filaments, as well as mitochondrial membranes and granular structures of the nuclear matrix. Our data suggest that the initial increase of p53 in cells that enter the cell cycle through G1 first bind to the actin cytoskeleton, and that some of the p53 then move into the nucleus to initiate gene activation and DNA synthesis for cell proliferation. This implies that there is some functionally significant interaction between p53 and actin in the cells.

Effects of a non-xanthine adenosine antagonist, CGS 15943, and a phosphodiesterase inhibitor, Ro 20-1724, in a light/dark test in mice

We investigated the effects of a non-xanthine adenosine receptor antagonist, CGS 15943, and a non-xanthine phosphodiesterase inhibitor, Ro 20-1724, in a light/dark test in mice. CGS 15943 at a dose of 50 mg/kg had no significant effects on any parameter, although at 10 mg/kg it significantly antagonized decreases in locomotion and rearing behavior induced by treatment with A1 and A2 selective agonists, N6-cyclopentyladenosine and CGS 21680 respectively. On the other hand, Ro 20-1724 decreased locomotion and rearing behavior in the light and dark zones, number of shuttle crosses between both zones, and the time spent in the light zone dose-dependently at doses ranging from 1-10 mg/kg. In conclusion, the phosphodiesterase inhibitor decreased all parameters in the light/dark test, while the adenosine antagonist showed no effect.

Effects of xanthine derivatives in a light/dark test in mice and the contribution of adenosine receptors

We investigated the effects of adenosine receptor antagonists, caffeine, theophylline, 8-phenyltheophylline, and 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), in a light/dark test in mice. All antagonists decreased the time spent in the light zone in this test, which suggested that these compounds have anxiogenic effects. The anxiogenic effects of theophylline were reduced by pretreatment with CGS 21680, an A2-selective agonist, but not by N6-cyclopentyladenosine (CPA), an A1-selective agonist. However, the antagonism of the theophylline-induced anxiogenic effects by CGS21680 was only observed in the time spent in the light zone, and DPCPX-induced anxiogenic effects were neither reversed by CGS 21680 nor by CPA. Finally, it is notable that xanthine-derived adenosine antagonists tested here commonly showed anxiogenic effects in the light/dark test in mice. It is suggested that there is a minor contribution of adenosine receptors to these effects, although theophylline-induced anxiogenic effects were antagonized by an A2 receptor agonist.

Effects of intracerebroventricular administration of N-acetylhistamine on body temperature in mice

The purpose of this study was to examine the effects of intracerebroventricular (i.c.v.) administration of N-acetylhistamine on rectal temperature, histamine level, histidine decarboxylase (HDC) activity, and the turnover rate of monoamines in mice. More than 60 micrograms of N-acetylhistamine induced hypothermia. The maximum effect of hypothermia was observed 20 min after administration of N-acetylhistamine (60-120 micrograms/mouse). A significant drop in rectal temperature of 3 degrees C was induced by 120 micrograms of N-acetylhistamine. Concurrent with the appearance of hypothermia, the histamine levels were increased. However, both histamine H1 and H2 antagonists did not prevent hypothermia. The i.c.v. administration of N-acetylhistamine inhibited HDC activity, but had no effect on the turnover rates of monoamines. These data confirmed that endogenous N-acetylhistamine may be a metabolite which lacks significant physiological roles, and demonstrated that exogenous N-acetylhistamine is not a good pharmacological tool for the study of the functions of the brain histaminergic system in mammals.

Laparoscopic cholecystectomy from fundus downward

Laparoscopic cholecystectomy from fundus downward (LCFD) is desirable when exposure of the cystic duct is difficult and hazardous. First the cystic duct and artery are exposed and clipped, and the artery is divided. Then removal of the gallbladder is started from fundus downward. After the gallbladder is dissected from the liver bed, the cystic duct is double clipped and divided. This approach affords better visualization of the cystic duct and common duct with less chance of common duct injury. Twenty-eight LCFDs were performed without complications, immediate or late. LCFD appears to be a safe procedure and does not compromise the retrograde method.

The effect of radix Salviae Miltiorrhizae Composita on peroxidation of low density lipoprotein due to copper dichloride

It is well known that plasma lipoprotein, particularly oxidized LDL, plays an important role in the pathogenesis of atherosclerosis and atherosclerotic diseases. We used oxidized LDL generated by incubating LDL from healthy persons with copper dichloride as a model to investigate the antioxidate property of Radix Salviae Miltiorrhizae Composita (RSMC). On photos, the spot X1 and the spot X2 were clearly found in the control group after the dialysis into copper dichloride for 24 and 48 hours, but they could not found in the RSMC group. The analysis of the constituents of lipids in LDL (by charring method) showed that after dialysis the percentages of the spot X1 and the spot X2 in the RSMC group were significantly lower than those in the control group (P < 0.01). The results suggest that RSMC plays a potential role in antioxidation of lipids or LDL.