The effects of a general anesthetic xenon (Xe) on spontaneous, miniature, electrically evoked synaptic transmissions were examined using the "synapse bouton preparation," with which we can clearly evaluate pure synaptic responses and accurately quantify pre- and postsynaptic transmissions. Glycinergic and glutamatergic transmissions were investigated in rat spinal sacral dorsal commissural nucleus and hippocampal CA3 neurons, respectively. Xe presynaptically inhibited spontaneous glycinergic transmission, the effect of which was resistant to tetrodotoxin, Cd, extracellular Ca, thapsigargin (a selective sarcoplasmic/endoplasmic reticulum Ca-ATPase inhibitor), SQ22536 (an adenylate cyclase inhibitor), 8-Br-cAMP (membrane-permeable cAMP analog), ZD7288 (an hyperpolarization-activated cyclic nucleotide-gated channel blocker), chelerythrine (a PKC inhibitor), and KN-93 (a CaMKII inhibitor) while being sensitive to PKA inhibitors (H-89, KT5720, and Rp-cAMPS).
View Article and Find Full Text PDFPesticides are essentially toxic to living things and are used openly, so it is necessary to monitor them to prevent their adverse effects. We have studied farmers'exposure to pesticides during soil fumigation operations with chloropicrin, and have noted a danger to the farmers in the form of dyspnea. We examined accidents/symptoms of residents from chloropicrin reported by the Ministry of Agriculture, Forestry, and Fishery from 2010 to 2019.
View Article and Find Full Text PDFJ Pharmacol Exp Ther
January 2023
In "synapse bouton preparation" of rat hippocampal CA3 neurons, we examined how Xe and NO modulate N-methyl-D-aspartate (NMDA) receptor-mediated spontaneous and evoked excitatory post-synaptic currents (sEPSC and eEPSC). This preparation is a mechanically isolated single neuron attached with nerve endings (boutons) preserving normal physiologic function and promoting the exact evaluation of sEPSC and eEPSC responses without influence of extrasynaptic, glial, and other neuronal tonic currents. These sEPSCs and eEPSCs are elicited by spontaneous glutamate release from many homologous glutamatergic boutons and by focal paired-pulse electric stimulation of a single bouton, respectively.
View Article and Find Full Text PDFPesticides are essentially toxic to living things, and, as they are used openly, it is necessary to monitor them and to prevent their adverse effects. A self-administered questionnaire survey given to a group of the greenhouse farmers told us that some of them developed dermatitis from acaricide cyflumetofen, so we conducted an interview study on dermatitis caused by cyflumetofen. The participants were affiliated with a strawberry producing group, and were interviewed at their annual health checkups in the spring of 2016 and 2017.
View Article and Find Full Text PDFProtecting the health of farmworkers is a crucial issue. Previous studies report that safety training and educational interventions might increase farmworkers' protective behaviors. The present study aimed to investigate the effectiveness of distributing a checklist as an interventional measure for pesticide protection in rural Asia, where pesticide poisoning is a major problem.
View Article and Find Full Text PDFKey Points: Xenon (Xe) non-competitively inhibited whole-cell excitatory glutamatergic current (I ) and whole-cell currents gated by ionotropic glutamate receptors (I , I , I ), but had no effect on inhibitory GABAergic whole-cell current (I ). Xe decreased only the frequency of glutamatergic spontaneous and miniature excitatory postsynaptic currents and GABAergic spontaneous inhibitory postsynaptic currents without changing the amplitude or decay times of these synaptic responses. Xe decreased the amplitude of both the action potential-evoked excitatory and the action potential-evoked inhibitory postsynaptic currents (eEPSCs and eIPSCs, respectively) via a presynaptic inhibition in transmitter release.
View Article and Find Full Text PDFSales of cut-flowers depend much on the outer appearance of the flowers. They are not intended to be used as foodstuffs; thus, pesticides are used more liberally for cut flower growing than for other agricultural products. Flower production is often carried out in greenhouses; therefore, pesticide exposure seems to reach not only the person spraying the pesticides, but also the non-spraying workers as well.
View Article and Find Full Text PDFThe acute effects of high-dose Li(+) treatment on glutamatergic and GABAergic transmissions were studied in the "synaptic bouton" preparation of isolated rat hippocampal pyramidal neurons by using focal electrical stimulation. Both action potential-dependent glutamatergic excitatory and GABAergic inhibitory postsynaptic currents (eEPSC and eIPSC, respectively) were dose-dependently inhibited in the external media containing 30-150 mM Li(+), but the sensitivity for Li(+) was greater tendency for eEPSCs than for eIPSCs. When the effects of Li(+) on glutamate or GABAA receptor-mediated whole-cell responses (IGlu and IGABA) elicited by an exogenous application of glutamate or GABA were examined in the postsynaptic soma membrane of CA3 neurons, Li(+) slightly inhibited both IGlu and IGABA at the 150 mM Li(+) concentration.
View Article and Find Full Text PDFObjective: Paraquat poisoning occurs worldwide, and both the fatality rate and the number of deaths are out of the ordinary. Japan is one of the few countries in the world that have replaced 24% products with 5% products. This report is an attempt to introduce information about paraquat poisoning in Japan.
View Article and Find Full Text PDFBackground: In Japan, treatment guidelines are lacking for patients with upper gastrointestinal symptoms. We aimed to compare the efficacy of different drugs for the treatment of uninvestigated upper gastrointestinal symptoms.
Methods: This was a randomized, open-label, parallel-group multicenter study.
The use of pesticides has rapidly increased in Japan since the end of World War II, significantly reducing work burdens and boosting food production. In the meantime, pesticides, responsible for poisoning and environmental pollution, have for many years posed grave issues that have had to be tackled by scientists of rural medicine for a long period. The Japanese Association of Rural Medicine, founded by the late Toshikazu Wakatsuki, has grappled with those issues for many years.
View Article and Find Full Text PDFProg Neuropsychopharmacol Biol Psychiatry
June 2009
Background: Patients with schizophrenia show a significantly higher frequency of hyperbilirubinemia than patients suffering from other psychiatric disorders and the general healthy population. We examined the hyperbilirubinemia on behavioral and neuropathological changes in rats as a possible animal model of schizophrenia.
Methods: Gunn rats with severe hyperbilirubinemia (j/j), Gunn rats without severe hyperbilirubinemia (+/j), and Wistar rats were examined by open-field, social interaction, and prepulse inhibition tests.
We have produced hybrid liposomes (HL) which can be prepared by ultrasonicating a mixture of dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene(23)dodecyl ether in a buffer solution. The fifty-percent inhibitory concentration (IC50) of HL on the growth of human B lymphoma (RAJI) cells in vitro was determined. The IC50 of HL on the growth of RAJI cells was one half of that of DMPC liposomes.
View Article and Find Full Text PDFAn antioxidative liposome catalysis that mimics both superoxide dismutase (SOD) and peroxidase (POD) activities has been developed by using the liposomes modified with lipophilic Mn-(5,10,15,20-tetrakis[1-hexadecylpyridium-4-yl]-21H,23H-porphyrin) (Mn-HPyP). The SOD- and POD-like activities of the Mn-HPyP-modified liposome were first investigated by varying the type of phospholipid, such as 1,2-distearyl-sn-glycero-3-phosphocholine (DSPC), 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC), and 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC). Higher SOD-like activity was obtained in the case of DLPC and DMPC liposomes, in which the ligands were well-dispersed on the membrane in the liquid crystalline phase.
View Article and Find Full Text PDFInt J Occup Environ Health
May 2008
Cases of dermatitis caused by pesticide exposures (n = 394), tabulated by the Division of Dermatology, Saku Central Hospital, Japan, from 1975 to 2000 are described. Dermatitis cases gradually decreased from 1975 to 2000, presumably accelerated by the phase-out of dermatitis-causing pesticides, including difolatan fungicide and salithion, an organophosphorous insecticide. Cases of chronic and solar dermatitides gradually decreased, which may be explained by reductions in the use of allergenic or photosensitive sulfur agents and organophosphates.
View Article and Find Full Text PDFThe serum and fecal testosterone (T) concentrations and testicular sizes of two male bharals (Pseudois nayaur) were determined for approximately one year. The profiles of the fecal T concentrations showed a similar tendency as the profiles of serum T concentrations, and there was a significant correlation between serum and fecal T concentrations (r=0.72).
View Article and Find Full Text PDFThe purpose of present study was to determine annual changes in serum progesterone (P(4)) concentrations and to clarify basic reproductive characteristics, such as breeding season, estrous cycle, and puberty in female bharals (Pseudois nayaur). Blood was collected from 9 female bharals once or twice weekly for approximately one year. Serum P(4) concentrations were determined by radioimmunoassay.
View Article and Find Full Text PDFHybrid liposomes composed of dimyristoylphosphatidylcholine (DMPC) and polyoxyethylene (n) dodecyl ether (C(12)(EO)(n), n=21 and 25) were prepared with the method of sonication. Clear solution of hybrid liposomes having hydrodynamic diameter of 80-100 nm could be maintained over 3 weeks. Hybrid liposomes induced apoptosis for human lymphoma (MOLT-4 and RAJI) cells in vitro.
View Article and Find Full Text PDFHighly inhibitory effects of hybrid liposomes on the growth of human breast tumor cells in vitro were obtained. It is worthy to note that induction of apoptosis through activation of caspases by hybrid liposomes was clearly observed.
View Article and Find Full Text PDFHigh inhibitory effects of hybrid liposomes (HL) themselves composed of DMPC/10 mol% C12(EO)23 on the growth of HL-60 cells were obtained without any drug. Induction of apoptosis was obtained by the HL of DMPC/10 mol% C12(EO)23. On the other hand, necrosis was observed for the HL of DLPC/10 mol% C12(EO)23.
View Article and Find Full Text PDFA biological membrane is the front line of defense for cells against various environmental stresses such as heat and reactive oxygen species (ROS) and is expected to play an important role in the antioxidant system with antioxidant enzymes, similarly to its chaperone-like function in cooperation with heat shock proteins. The oxidative stress response of superoxide dismutase (SOD), which is known to catalyze the dismutation of O(2)(-) to H(2)O(2), was investigated in the presence of artificial membranes, liposomes, in order to obtain fundamental information on the biological ROS scavenging system. SOD lost its activity in the presence of H(2)O(2) and was found to have two loops including one which contains an alpha-helix which presents the substrate O(2)(-) to the activity center of SOD (Cu(II)).
View Article and Find Full Text PDFProlonged survival was seen in a carcinoma model in mice intraperitoneally inoculated with B-16 melanoma cells after the intraperitoneal treatment with hybrid liposomes composed of L-alpha-dimyristoylphosphatidylcholine (DMPC) and polyoxyethylenedodecyl ether (C12(EO)n, n = 10 and 23 respectivery) which had a uniform and stable structure. No drug was administered. The therapeutic effects of the single-component liposomes composed of lipids with a variety of hydrophilic head groups and different hydrophobic alkyl chains were investigated.
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