BACKGROUND: Vagal nerve plays an important role in the stomach function. The cholinergic nerves are the most abundantly distributed nerves in the gastric tissue. It has recently been reported that the vagal nerve is significantly related to both gastric cancer development and progression. However, its relation to the mesenchymal tumor, including MALT lymphoma, is not known. In this study, we investigated the effect of unilateral truncal vagotomy on gastric MALT lymphoma development by using Helicobacter heilmannii-infected mouse model as well as that of bilateral truncal vagotomy on stress-induced ulcer formation. METHODS: In the first part of this study, the distribution of the cholinergic nerves in the rat gastric mucosa and the effect of bilateral truncal vagotomy, as well as various kinds of agents acting on autonomic nerves in rats, were investigated by the histochemical and macroscopic method. In the second part, we employed MALT lymphoma formation in C57BL/6NCrl mice that were infected with Helicobacter heilmannii. A total of 38 infected mice underwent unilateral vagotomy under microscopy. The mice were randomized into 4 groups from which samples were collected; 2, 3, 4 and 6 months after infection. Both the anterior and posterior sides of the stomachs were sampled from each mouse for pathological and immunohistochemical analyses. RESULTS: The bilateral truncal vagotomy significantly suppressed the restraint-induced gastric ulcer formation in rats, while bethanechol, and 6-hydroxydopamine led to an increase of the gastric ulcer formation. In the unilateral truncal vagotomy study using MALT lymphoma, the thickness of the gastric mucosa was reduced in the vagotomized side compared to the non-vagotomized side. Furthermore, the gastric MALT lymphoma was more prominently found in the vagotomized anterior side of stomach compared with that in the non-vagotomized posterior side of stomach. Substance P-immunoreactive nerves markedly increased surrounding the MALT lymphoma and the neurokinin-1 receptor immunoreactive lymphocytes increased within the MALT lymphoma in the vagotomized side. In conclusion, vagotomy enhanced gastric MALT lymphoma development possibly through the substance P-neurokinin-1 receptor pathway.
Title: Characterization of a novel Aspergillus oryzae tannase expressed in Pichia pastoris Koseki T, Ichikawa K, Sasaki K, Shiono Y Ref: J Biosci Bioeng, 126:553, 2018 : PubMed
We report the characterization of tannase-encoding gene, AotanB, from Aspergillus oryzae and its recombinant enzyme expressed in Pichia pastoris. The gene except for the signal sequence was cloned into a vector pPICZalphaA and the recombinant protein was secreted into the medium as an active enzyme. Recombinant AoTanB highly expressed in the incubation at 18 degrees C compared to 30 degrees C. Purified recombinant protein exhibited smeared band with molecular mass of approximately 90-120 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The recombinant protein yielded molecular mass of 65 kDa after N-deglycosylation. Purified recombinant enzyme had a pH and a temperature optima of 6.0 and 30-35 degrees C, respectively, and was stable up to 40 degrees C. Recombinant AoTanB was able to release gallic acid from natural substrates, such as (-)-catechin gallate, (-)-epicatechin gallate, (-)-gallochatechin gallate, and (-)-epigallocatechin gallate. The enzyme also hydrolyzed ethyl protocatechuate. Meanwhile, no activity was detected toward ethyl 4-hydroxybenzoate. The activity of recombinant AoTanB was lower toward natural substrates compared to that of AoTanA from A. oryzae. The lower catalytic efficiency (kcat/Km value) toward ethyl protocatechuate was due to a combination of increased Km and considerably decreased kcat. Kinetic analysis of the recombinant AoTanB showed that kcat values toward natural substrates decreased compared to those of recombinant AoTanA. Therefore, recombinant AoTanB showed a decrease in catalytic efficiency (kcat/Km value) compared to recombinant AoTanA was due to considerably lower kcat value.
Eleven abietane-type diterpenoids and two known abietanes were isolated from the roots of Caryopteris mongolica, and their structures were characterized. The absolute configurations at C-5 and C-10 were determined from the NMR data, including from the nuclear Overhauser effect and CD spectra, and the absolute configuration of C-16 in the hydroxypropyl group was determined via a modified Mosher's method. Furthermore, the previously unknown absolute configuration of the C-15 of cyrtophyllone B was determined to be in an R-configuration using X-ray crystallography. To estimate the preventive effects of the isolates for neurodegenerative disease development, their inhibitory activities against acetylcholinesterase (AChE) from human erythrocytes and butyrylcholinesterase (BChE) from horse serum were evaluated.
A diterpenoid diglucoside (12,19-di-O-beta-D-glucopyranosyl-11-hydroxyabieta-8,11,13-triene-19-one), isoscutellarein 7-O-[beta-D-xylopyranosyl-(1-->2)]-beta-D-glucopyranoside, isoscutellarein 7-O-[alpha-L-rhamnopyranosyl-(1-->2)]-beta-D-glucopyranoside, hypolaetin 7-O-[6''-O-(p-E-coumaroyl)]-beta-D-glucopyranoside, hypolaetin 7-O-[6''-O-(E-caffeoyl)]-beta-D-glucopyranoside, and 15 known compounds were isolated from aerial parts of the Mongolian medicinal plant Caryopteris mongolica. The cholinesterase-inhibitory activities of the constituents were estimated. The abietane diterpenoids (12-O-demethylcryptojaponol and 6alpha-hydroxydemethylcryptojaponol) showed potent inhibitory activity against acetylcholinesterase from human erythrocytes and electric eel, and against butyrylcholinesterase from horse serum.
Title: Isolation of a thermotolerant photosynthetic bacterium, Rhodobacter sphaeroides Strain, NAT, and its capacity for oil and chemical oxygen demand removal at high temperatures Yamaoka Y, Takeno K, Shinkawa H, Noparatnaraporn N, Sasaki K Ref: Biosci Biotechnol Biochem, 72:1601, 2008 : PubMed
A thermotolerant photosynthetic bacterium NAT identified as Rhodobacter sphaeroides was isolated. When alginate-immobilized cells of strain NAT were used in high-temperature treatment of artificial sewage wastewater containing oil, the chemical oxygen demand (COD) decreased by 80% and 76% of the oil was removed after 96 h of treatment at 55 degrees C. Lipase activity was observed in the culture.
Title: Purification of proplatelet formation (PPF) stimulating factor: thrombin/antithrombin III complex stimulates PPF of megakaryocytes in vitro and platelet production in vivo Ishida Y, Yano K, Ito T, Shigematus H, Sasaki K, Kondo S, Kuriya S Ref: Thromb Haemost, 85:349, 2001 : PubMed
In this study, the protein which stimulates proplatelet formation (PPF) of megakaryocytes was purified from normal human plasma using 7 steps procedures. Two different protease inhibitors were identified based on their amino acid sequences, i.e. antithrombin III (AT III) and C1 inhibitor. They were included in high density lipoprotein (HDL). HDL was necessary for AT III to be active in PPF in vitro. The biological effects of the AT III/HDL or thrombin-AT III (TAT)/HDL were studied in vitro. PPF of murine megakaryocytes was stimulated by negative control (BSA) (1.8 +/- 0.3%), AT III (2.0 +/- 0.4%), HDL (1.2 +/- 0.9%), AT III/HDL (14.8 +/- 2.1%) or TAT/HDL (23.3 +/- 3.5%), respectively. TAT/HDL also had a synergistic effect with the mpl ligand, judging by the acetylcholinesterase (AchE) expression of murine megakaryocytes (2.7 fold increase). In vivo subcutaneous administration of AT III alone or TAT for 3 days significantly stimulated thrombocytosis (136% and 144%, respectively, p<0.05) and AT III/HDL showed rapid and further stimulation (150%, p <0.01). These results and the previous studies indicate that megakaryocytopoiesis is regulated by the mpl ligand, while a protease/protease inhibitor complex such as TAT, which is involved in the coagulation cascade associated with platelet consumption, might be one of the regulators in platelet production.
Title: [Studies on the stability of 89 pesticides in organic solvent] Nemoto S, Takatsuki S, Sasaki K, Toyoda M Ref: Kokuritsu Iyakuhin Shokuhin Eisei Kenkyusho Hokoku, 115:86, 1997 : PubMed
The stability of 89 pesticides (17 organochlorine, 33 organophosphorus, 8 pyrethroid, 12 carbamate, and 19 other pesticides) in 6 kinds of organic solvents (methanol, ethanol, 2-propanol, ethyl acetate, n-hexane, and acetone) was investigated using gas chromatography/mass spectrometry (GC/MS). All of the investigated pesticides were stable in all of the tested organic solvents during storage for 6 hours at room temperature in the dark except captafol, captan, phosmet, chinomethionat, and dicofol. However, the decreases of captafol, captan, phosmet, and chinomethionat were observed in methanol. The decreases of captafol, captan, and phosmet were also observed in ethanol. Moreover, the decrease of dicofol was observed in acetone. The decrease of captafol dissolved in methanol at a concentration of 2 micrograms/ml was faster than those of captan, phosmet, and chinomethionat; the residual captafol was 75% after 30 min of storage. Dicofol dissolved in acetone also decreased during storage in a refrigerator. 4,4'-dichlorobenzophenone (DCBP) and chlorobutanol were detected in the acetone solution of dicofol after storage. Furthermore, it was found that dicofol was decomposed by acetone at an injection port, and DCBP and chlorobutanol were formed when it was injected into GC with acetone.
Title: Simplified cleanup and gas chromatographic determination of organophosphorus pesticides in crops Sasaki K, Suzuki T, Saito Y Ref: J Assoc Off Analytical Chemistry, 70:460, 1987 : PubMed
A simple and efficient cleanup method for gas chromatographic determination of 23 organophosphorus pesticides in crops including onion is described. The sample was extracted with acetone. The extract was purified with coagulating solution, which contained ammonium chloride and phosphoric acid, and then filtered by suction. The filtrate was diluted with NaCl solution and reextracted with benzene. The organic layer was evaporated and injected into a gas chromatograph equipped with a flame photometric detector (FPD) and fused silica capillary columns (0.53 mm id) coated with silicone equivalent to OV-1701, OV-1, and SE-52. Onion extract, which contained FPD interferences, was cleaned up on a disposable silica cartridge. Recoveries of most organophosphorus pesticides from spiked crops: mandarin orange, tomato, spinach, sweet pepper, broccoli, lettuce, and onion at levels of 0.02-0.28 ppm, exceeded 80%, but the water-soluble pesticides dichlorvos and dimethoate gave poor recoveries in all crops; the nonpolar pesticides disulfoton, chlorpyrifos, fenthion, prothiophos, and leptophos were not recovered quantitatively in spinach, sweet pepper, broccoli, and lettuce. IBP, edifenphos, phosmet, and pyridaphenthion were not recovered from onion because of adsorption to the silica cartridge. The detection limits ranged from 1.25 to 17.5 ppb on a crop basis.
Title: The excitatory synaptic action of climbing fibres on the Purkinje cells of the cerebellum Eccles JC, Llinas R, Sasaki K Ref: The Journal of Physiology, 182:268, 1966 : PubMed
1. A single climbing fibre makes an extraordinarily extensive synaptic contact with the dendrites of a Purkinje cell. Investigation of this synaptic mechanism in the cerebellum of the cat has been based on the discovery by Szentagothai & Rajkovits (1959) that the climbing fibres have their cells of origin in the contralateral inferior olive.2. Stimulation in the accessory olive selectively excites fibres that have a powerful synaptic excitatory action on Purkinje cells in the contralateral vermis, evoking a repetitive spike discharge of 5-7 msec duration. Almost invariably this response had an all-or-nothing character. In every respect it corresponds with the synaptic action that is to be expected from climbing fibres.3. Intracellular recording from Purkinje cells reveals that this climbing fibre stimulation evokes a large unitary depolarization with an initial spike and later partial spike responses superimposed on a sustained depolarization.4. Typical climbing fibre responses can be excited, but in a much less selective manner, by stimulation of the olive-cerebellar pathway in the region of the fastigial nucleus, there being often a preceding antidromic spike potential of the Purkinje cell under observation.5. Impaled Purkinje cells rapidly deteriorate with loss of all spike discharge, the climbing fibre response being then reduced to an excitatory post-synaptic potential. This potential shows that stimulation of the inferior olive may evoke two or more discharges at about 2 msec intervals in the same climbing fibre. The complexity of neuronal connexions in the inferior olive is also indicated by the considerable latency range in responses.6. A further complication is that, with stimulation in the region of the fastigial nucleus, the initial direct climbing fibre response is often followed by a reflex discharge, presumably from the inferior olive, which resembles the responses produced by inferior olive stimulation in being often repetitive.7. Typical climbing fibre responses have been evoked by peripheral nerve stimulation and frequently occur spontaneously.8. An account is given of the way in which the responses evoked by climbing fibres in the individual Purkinje cells can account for the potential fields that an inferior olive stimulus evokes on the surface and through the depth of the cerebellar cortex.9. By the application of currents through the recording intracellular electrode it has been possible to effect large changes in the excitatory post-synaptic potential produced by a climbing fibre, it being diminished and even reversed with depolarizing currents and greatly increased by hyperpolarizing currents.
Title: Intracellularly recorded responses of the cerebellar Purkinje cells Eccles JC, Llinas R, Sasaki K Ref: Experimental Brain Research, 1:161, 1966 : PubMed
Title: Parallel fibre stimulation and the responses induced thereby in the Purkinje cells of the cerebellum Eccles JC, Llinas R, Sasaki K Ref: Experimental Brain Research, 1:17, 1966 : PubMed
Title: Interaction experiments on the responses evoked in Purkinje cells by climbing fibres Eccles JC, Llinas R, Sasaki K, Voorhoeve PE Ref: The Journal of Physiology, 182:297, 1966 : PubMed
1. The uniquely powerful excitatory synaptic action of a single climbing fibre on a Purkinje cell in the cerebellum of the cat was tested during the intense and prolonged inhibitory action produced by the parallel fibre, basket and stellate cell system. There was depression of the later spike discharges, but the initial discharge was never suppressed.2. With intracellular recording the excitatory post-synaptic potential was depressed during the initial phase (about 10 msec) of the inhibitory action, but there was a later increase with a time course resembling the latter part of the inhibitory hyperpolarization. An explanation of these and other effects is given in terms of conventional ideas of excitatory and inhibitory synaptic interaction.3. These observations on single Purkinje cells, particularly with intracellular recording, have helped in formulating a provisional explanation of the finding that during inhibition there is an increase in the negative field potential evoked by a climbing fibre volley.4. The excitatory action of a climbing fibre synapse is shown to be greatly depressed immediately after a preceding activation and recovery takes hundreds of milliseconds. By the collision technique it is shown that the same climbing fibre is activated by inferior olive and juxta-fastigial stimulation.5. With rapid repetitive activation there was initially a progressive decline in the effectiveness of each successive impulse, but a steady level was soon reached. On cessation of a tetanus of twenty or more impulses there was a delayed recovery of the depolarization, which suggests a continued action of the accumulated transmitter.6. With extracellular recording repetitive spike initiation continued with stimulation frequencies as high as 100/sec, but at still higher frequencies spikes were depressed by the intense synaptically evoked depolarization. On cessation of the stimulation after-discharge often developed as the depolarization declined. The prolonged after-discharges following severe tetani suggest that there is a very effective accumulation of the transmitter.
