ABSTRACT
Parvalbumin interneurons belong to the major types of GABAergic interneurons. Although the distribution and pathological alterations of parvalbumin interneuron somata have been widely studied, the distribution and vulnerability of the neurites and fibers extending from parvalbumin interneurons have not been detailly interrogated. Through the Cre recombinase-reporter system, we visualized parvalbumin-positive fibers and thoroughly investigated their spatial distribution in the mouse brain. We found that parvalbumin fibers are widely distributed in the brain with specific morphological characteristics in different regions, among which the cortex and thalamus exhibited the most intense parvalbumin signals. In regions such as the striatum and optic tract, even long-range thick parvalbumin projections were detected. Furthermore, in mouse models of temporal lobe epilepsy and Parkinson's disease, parvalbumin fibers suffered both massive and subtle morphological alterations. Our study provides an overview of parvalbumin fibers in the brain and emphasizes the potential pathological implications of parvalbumin fiber alterations.
Subject(s)
Mice , Animals , Epilepsy, Temporal Lobe/pathology , Parvalbumins/metabolism , Parkinson Disease/pathology , Neurons/metabolism , Interneurons/physiology , Disease Models, Animal , Brain/pathologyABSTRACT
Objective To improve the detection ability of laboratories, and to identify possible technical defects in the detection of dichloroacetic acid and trichloroacetic acid in drinking water. Methods A number of laboratories were organized to conduct interlaboratory determination of dichloroacetic acid and trichloroacetic acid in drinking water. Prefabricated standard series and intermediate samples were distributed. Data of determination were collected and statistically analyzed to evaluate the detection results. Results The slopes of dichloroacetic acid and trichloroacetic acid working curves were analyzed by Grubbs test. The analysis results showed that there were 1 outlier in the dichloroacetic acid data and 3 outliers in the trichloroacetic acid data, respectively. The determination results of the spiked samples of dichloroacetic acid and trichloroacetic acid were 1.5 and 4 times the actual value, respectively. Conclusion This investigation reveals that there exist some technical problems in the direct determination of dichloroacetic acid and trichloroacetic acid by gas chromatography, such as inappropriate selection of chromatographic conditions and injection port flow control, and incorrect way of spiking internal standards.
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ObjectiveTo establish a method for the determination of 8 volatile halogenated hydrocarbons in drinking water， including vinyl chloride， trichloroethylene， tetrachloroethylene， tetrachloromethane， chloroform， dichlorobromomethane， dichlorodibromomethane， and tribromomethane by headspace thermal desorption-gas mass spectrometry. MethodsThe water sample was kept in the headspace bottle at 60 ℃ for 40 min， and the volatile matter was transferred to the cold trap，subjected to thermal desorption， then analyzed by gas chromatography-mass spectrometry. ResultsThe linear ranges were 0.2‒20.0 μg·L-1 for vinyl chloride， 0.1‒20.0 μg·L-1 for chloroform， 0.02‒20.00 μg·L-1 for tetrachloromethane， 0.2‒20.0 μg·L-1 for trichloroethylene， 0.3‒20.0 μg·L-1 for dichlorobromomethane， 0.1‒20.0 μg·L-1 for tetrachloroethylene， 0.4‒20.0 μg·L-1 for dichlorodibromomethane， and 1.0‒20.0 μg·L-1 for tribromomethane. All the correlation coefficients were more than 0.997. The respective quantitative limits were 0.162， 0.073， 0.016， 0.184， 0.270， 0.071， 0.356 and 0.813 μg·L-1， and the respective recoveries were 98.0%‒101.0%， 102.0%‒110.0%， 99.2%‒101.0%， 95.5%‒96.2%， 96.0%‒102.0%， 100.0%‒102.0%， 99.0%‒105.0%， and 94.0%‒103.0%. ConclusionThe method is simple， sensitive， rapid， accurate and reliable， so it is applicable for the determination of 8 kinds of volatile halogenated hydrocarbons in drinking water.
ABSTRACT
A large number of basic and clinical studies have shown that the Chinese herbs with promoting blood circulation and resolving phlegm effects could prevent and treat myocardial ischemia-reperfusion injury(MIRI) by regulating lipid metabolism. But its mechanism is not yet clear. The studies show that mitochondrial DNA (mtDNA), microRNAs and lipid metabolism participate in the whole process of MIRI and affect the prognosis. mtDNA mutation is the primary factor to cause myocardial ischemia and reperfusion myocardial cell damage. microRNAs aggravate or reduce MIRI injury by down-regulating or up-regulating related genes expression, while miR-33, as a key regulator of cholesterol transport, regulates lipid metabolism through CROT, PGC-1α, AMPK and other genes located in the mitochondria. There are less studies on correlation between miR-33 and mtDNA, microRNAs. Therefore, further studies on the correlation between miR-33 and mtDNA, microRNAs, as well as the discussions on whether the traditional Chinese medicine (TCM) with promoting blood circulation and resolving phlegm effects could target miR-33 to regulate lipid metabolism and inducemt DNA mutations or deletions, would have important significance for the prevention and treatment of MIRI.
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Objective To apply the HS-GC method to measure eleven kinds of chlorobenzenes and hexachlorobutadiene in drinking water . Methods We put 10 mL water sample into a 20 mL vial containing 2.5 g sodium chloride .The vial was stirred at 80℃ for 15 mins prior to headspace sampling . Eleven kinds of chlorobenzenes were separated completely by Rtx-1 701 capillary column(30.00 m ×0.25 mm ×0.25 μm),detected by electron capture detectors . Results The linearity of the method ranged from 1.00-32.00 μg/L, 0.20-6.40 μg/L, 0.05-1.60 μg/L, 0.02-0.64 μg/L, 0.02-0.64 μg/L and 0 .01-0 .32 μg/L for dichlorobenzene isomers , trichlorobenzene isomers , tetrachlorobenzene isomers , pentachlorobenzene , hexachlorobenzene and hexachlorobutadiene .In case of a 10 mL water sample , the lowest detected range of mass concentration was 0.001 62-0.262 00 μg/L.The additional standard recovery rate of finished water samples was in the range of 80%-119%with the relative standard deviation (RSD) in the range of 2.24%-4.99%. Conclusion This method is simple, fast, sensitive and needs no organic solvents .It is suitable for measuring both chlorobenzene compounds and hexachlorobutadiene in drinking water simultaneously .
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Objective To develop the methods for determination of nitromethane,nitroethane,1-nitropropane,2-nitropropane in the air of workplace. Methods Nitromethane,nitroethane,1-nitropropane,2-nitropropane in the air of workplace were collected by active carbon tube,desorbed in ethyl acetate solution and detected by capillary gas chromatography (GC-FID). Results The linear concentration range of nitromethane,nitroethane,1-nitropropane,2-nitropropane was 43.2-345.3,177.6-1 421.0,68.5-547.7,24.1-192.4 ?g/ml respectively and the relative standard deviation was 1%-5%. Sampling efficiency was 100%,desorption efficiency was 91%-93%. The sample could be resaved at 4-10 ℃ for 5-7 days. Conclusion The method is applicable to determination of nitromethane,nitroethane,1-nitropropane,2-nitropropane in the air of workplace.