Contrast-enhanced CT-based radiomics differentiate anterior mediastinum lymphoma from thymoma without myasthenia gravis and calcification

AIM

To explore the value of a radiomics model based on enhanced computed tomography (CT) in differentiating anterior mediastinal lymphoma (AML) and thymoma without myasthenia gravis (MG) and calcification.

MATERIALS AND METHODS

The present study analysed patients who were diagnosed histologically with AML and thymoma in three independent institutions. All pre-treatment patients underwent enhanced CT. In the training group of patients from institutions 1 (the First Affiliated Hospital of Kunming Medical University) and 3 (the Yunnan Cancer Hospital), two radiologists independently analysed the enhanced CT images and performed manual segmentation of each tumour. Radiomics features were screened using interobserver interclass coefficient (ICC) analysis, feature correlation analysis, and L1 regularisation. The discriminative efficacy of the logistic regression model was evaluated using receiver operating characteristic (ROC) analysis. Validation group of patients from institution 2 (the Second Affiliated Hospital of Zhejiang University School of Medicine) was used to validate the proposed models.

RESULTS

A total of 114 patients were enrolled in this study and 1,743 radiomics features were extracted from the enhanced CT images. After feature screening, the remaining 37 robust radiomics features were used to construct the model. In the training group, the AUC of the model was 0.987 (95% confidence interval [CI]: 0.976-0.999), the sensitivity, specificity, and accuracy were 0.912, 0.946, and 0.924, respectively. In the validation group, the AUC of the model was 0.798 (95% CI: 0.683-0.913), the sensitivity, specificity, and accuracy were 0.760, 0.700, and 0.743, respectively.

CONCLUSION

The radiomics model created provided effective information to assist in the selection of clinical strategies, thus reducing unnecessary procedures in patients with AML and guiding direct surgery in patients with thymoma to avoid biopsy.

Enhancing Ru-Cl interaction via orbital hybridization effect in Ru0.4Sn0.3Ti0.3 electrode for efficient chlorine evolution

Chlorine evolution reaction (CER) is a commercially valuable electrochemical reaction used at an industrial scale. However, oxygen evolution reaction (OER) during the electrolysis process inevitably leads to the decreased efficiency of CER. It is necessary to improve the selectivity of CER by minimizing or even eliminating the occurrence of OER. Herein, a ternary metal oxide (Ru0.4Sn0.3Ti0.3) electrode was fabricated and employed as an active and robust anode for CER. The Ru0.4Sn0.3Ti0.3 electrode exhibits an excellent CER performance in 6.0 M NaCl solution, with a low potential of 1.17 V (vs. saturated calomel electrode, SCE) at 200 mA cm-2 current density, a high Cl2 selectivity of over 90 %, and robust durability after consecutive operation for 160 h under 100 mA cm-2. The maximum O2-Cl2 potential difference between OER and CER further demonstrates the high Cl2 selectivity of Ru0.4Sn0.3Ti0.3 electrode. Theoretical studies show that the strong Ru 3d-Ti 3d orbitals hybridization effect makes the d-band center (εd) of Ru 3d and Ti 3d orbitals positively and negatively shifted, respectively, endowing Ru site with enhanced Cl adsorption ability (i.e. enhanced Ru-Cl interaction) and Ru0.4Sn0.3Ti0.3 electrode with superior CER activity. This work offers valuable insights into the development of advanced electrodes for CER in practical application.

Modulating the d-Band Center Enables Ultrafine Pt3 Fe Alloy Nanoparticles for pH-Universal Hydrogen Evolution Reaction

By providing dual active sites to synergistically accelerate H2 O dissociation and H+ reduction, ordered intermetallic alloys usually show extraordinary performance for pH-universal hydrogen evolution reaction (HER). Herein, activated N-doped mesoporous carbon spheres supported intermetallic Pt3 Fe alloys (Pt3 Fe/NMCS-A), as a highly-efficient electrocatalyst for pH-universal HER, are reported. The Pt3 Fe/NMCS-A exhibits low overpotentials (η10 ) of 13, 29, and 48 mV to deliver 10 mA cm-2 in 0.5 m H2 SO4 , 1.0 m KOH, and 1.0 m phosphate buffered solution (PBS), respectively, as well as robust stability to maintain the overall catalytic performances. Theoretical studies reveal that the strong Pt 5d-Fe 3d orbital electronic interactions negatively shift the d-band center (εd ) of Pt 5d orbital, resulting in reduced H* adsorption energy of Pt sites and enhanced acidic HER activity. With Pt and Fe acting as co-adsorption sites for H* and *OH intermediates, respectively, a low energy barrier is required for Pt3 Fe/NMCS-A to dissociate H2 O to afford H* intermediates, which greatly promotes the H* adsorption and H2 formation in alkaline and neutral conditions. The synthetic strategy is further extended to the synthesis of Pt3 Co and Pt3 Ni alloys with excellent HER activity in pH-universal electrolytes, demonstrating the great potential of these Pt-based alloys for practical applications.

A non-dispersive infrared sensor for real-time detection of cyanogen chloride

Cyanogen chloride, as a systemic toxic agent, can cause death rapidly. In this paper, a non-dispersive infrared sensor was designed for the infrared absorption detection of cyanogen chloride at 800 cm−1. The roughness of the internal coating material was analyzed by experiments, and the gold-plated gas chamber was selected. The light path propagation of different cross-section gas chambers was simulated, and the circular section gas chamber was selected to increase the infrared detector signal. The effect of flow rate on voltage was studied. The standard curve between voltage and concentration was obtained under the optimal condition of 0.4 L min−1. The maximum response time was 19 s, and RSD was less than 2%. The interference experiment results showed that common gases entering the gas chamber do not cause interference. The non-dispersive infrared sensor for cyanogen chloride has good stability and detects cyanogen chloride in real-time.

Pt Single Atoms Supported on N-Doped Mesoporous Hollow Carbon Spheres with Enhanced Electrocatalytic H2 -Evolution Activity

The electronic metal-support interaction (EMSI) plays a crucial role in catalysis as it can induce electron transfer between metal and support, modulate the electronic state of the supported metal, and optimize the reduction of intermediate species. In this work, the tailoring of electronic structure of Pt single atoms supported on N-doped mesoporous hollow carbon spheres (Pt₁ /NMHCS) via strong EMSI engineering is reported. The Pt₁ /NMHCS composite is much more active and stable than the nanoparticle (Pt_NP ) counterpart and commercial 20 wt% Pt/C for catalyzing the electrocatalytic hydrogen evolution reaction (HER), exhibiting a low overpotential of 40 mV at a current density of 10 mA cm^-2 , a high mass activity of 2.07 A mg^-1 _Pt at 50 mV overpotential, a large turnover frequency of 20.18 s^-1 at 300 mV overpotential, and outstanding durability in acidic electrolyte. Detailed spectroscopic characterizations and theoretical simulations reveal that the strong EMSI effect in a unique N₁ -Pt₁ -C₂ coordination structure significantly tailors the electronic structure of Pt 5d states, resulting in promoted reduction of adsorbed proton, facilitated H-H coupling, and thus Pt-like HER activity. This work provides a constructive route for precisely designing single-Pt-atom-based robust electrocatalysts with high HER activity and durability.

In Situ Transformation of Prussian-Blue Analogue-Derived Bimetallic Carbide Nanocubes by Water Oxidation: Applications for Energy Storage and Conversion

Using bimetallic Prussian blue analogue (PBA) as a precursor is effective for preparing electrocatalysts for the oxygen evolution reaction (OER); however, the role of these PBA-derived catalysts in the OER is still ambiguous. Herein, by simply controlling synthesis temperature, a bimetallic PBA-derived O,N-codoped Ni-Fe carbide, can be well tuned to optimize structure and OER performance. Importantly, by a series of ex situ and in situ investigations, real active species of NiFeO_x H_y are in situ formed on the surface during the OER, which reveals a "pre-catalyst" role of O,N-codoped Ni-Fe carbides. Furthermore, it has been successfully applied to highly efficient Zn-air batteries and outplays its RuO₂ counterpart. When applied to photoelectrocatalytic water oxidation as the co-catalyst, it improves the performance of the BiVO₄ photoanode by enhancing hole collecting and transporting ability. We believe this research not only provides a highly efficient and low-cost electrocatalyst for the OER, but also unveils the "pre-catalyst" role of PBA-derived materials in energy-storage and conversion devices.

FLASHForward: plasma wakefield accelerator science for high-average-power applications

The FLASHForward experimental facility is a high-performance test-bed for precision plasma wakefield research, aiming to accelerate high-quality electron beams to GeV-levels in a few centimetres of ionized gas. The plasma is created by ionizing gas in a gas cell either by a high-voltage discharge or a high-intensity laser pulse. The electrons to be accelerated will either be injected internally from the plasma background or externally from the FLASH superconducting RF front end. In both cases, the wakefield will be driven by electron beams provided by the FLASH gun and linac modules operating with a 10 Hz macro-pulse structure, generating 1.25 GeV, 1 nC electron bunches at up to 3 MHz micro-pulse repetition rates. At full capacity, this FLASH bunch-train structure corresponds to 30 kW of average power, orders of magnitude higher than drivers available to other state-of-the-art LWFA and PWFA experiments. This high-power functionality means FLASHForward is the only plasma wakefield facility in the world with the immediate capability to develop, explore and benchmark high-average-power plasma wakefield research essential for next-generation facilities. The operational parameters and technical highlights of the experiment are discussed, as well as the scientific goals and high-average-power outlook. This article is part of the Theo Murphy meeting issue 'Directions in particle beam-driven plasma wakefield acceleration'.

Metal-Organic Framework-Derived Nickel-Cobalt Sulfide on Ultrathin Mxene Nanosheets for Electrocatalytic Oxygen Evolution

Water oxidation is the key process for many sustainable energy technologies containing artificial photosynthesis and metal-air batteries. Engineering inexpensive yet active electrocatalysts for water oxidation is mandatory for the cost-effective generation of solar fuels. Herein, we propose a novel hierarchical porous Ni-Co-mixed metal sulfide (denoted as NiCoS) on Ti₃C₂T _x MXene via a metal-organic framework (MOF)-based approach. Benefiting from the unique structure and strong interfacial interaction between NiCoS and Ti₃C₂T _x sheets, the hybrid guarantees an enhanced active surface area with prominent charge-transfer conductivity and thus a superior activity toward oxygen evolution reactions (OERs). Impressively, the hierarchical NiCoS in the hybrid is converted to nickel/cobalt oxyhydroxide-NiCoS assembly (denoted as NiCoOOH-NiCoS) by OER measurement, where NiCoOOH on the surface is confirmed as the intrinsic active species for the consequent water oxidation. The hybrid material is further applied to an air cathode for a rechargeable zinc-air battery, which exhibits low charging/discharging overpotential and long-term stability. Our work underscores the tuned structure and electrocatalytic OER performance of MOF derivatives by the versatility of MXenes and provides insight into the structure-activity relationship for noble metal-free catalysts.

Graphdiyne: a superior carbon additive to boost the activity of water oxidation catalysts

A new carbon allotrope, graphdiyne (GDY), with a highly π-conjugated structure of sp- and sp²-hybridized carbon networks, has recently emerged and been used as a superior carbon additive to boost the activity of water oxidation catalysts. In this work, a hybrid GDY/NiFe-LDH electrocatalyst was prepared by a facile hydrothermal treatment, which shows an outstanding catalytic activity with a low overpotential of 260 mV at 10 mA cm^-2 catalytic current density and good durability towards oxygen evolution in 1.0 M KOH solution. Density functional theory (DFT) calculations prove that the sp- and sp²-hybridized GDY shows both superior electron capture and excellent electron transfer ability compared to that of the conventional sp²-hybridized carbon materials.

Reversed effects of RU486 and anisomycin on memory retention of light exposure or corticosterone facilitation in the dark-incubated chicks

Memory formation for a weak passive avoidance task in the dark-incubated chicks is facilitated by light exposure or corticosterone administration at optimally pre-hatch time points. To explore the potential mechanisms underlying activation of brain memory function development by light or corticosterone exposure during late embryo, steroid receptor antagonist RU486, or protein synthetic inhibitor anisomycin, was administered intraembryonically to the embryos of either only 24-h light-exposure or complete dark-hatched on embryonic day 20 (E20). The results showed that RU486 and anisomycin significantly retarded the facilitated retention both by light and corticosterone exposure in the dark-incubated chicks. They also suggest that the act of corticosterone or light exposure on the development of brain memory function is mediated by the effect of steroid receptor, or afterward on related protein syntheses that is involved in memory formation of post-hatched performance of day-old chicks.

Effect of batroxobin on expression of neural cell adhesion molecule in temporal infarction rats and spatial learning and memory disorder

The effect of Batroxobin expression of neural cell adhesion molecule (NCAM) in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemical methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats and at the same time NCAM expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of NCAM immune reactive cells of Batroxobin-treated rats was more than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats and the regulation of the expression of NCAM is probably related to the neuroprotective mechanism.

Batroxobin against anoxic damage of rat hippocampal neurons in culture: morphological changes and Hsp70 expression

Batroxobin, the thrombin-like enzyme, is used for therapeutic defibrination. We have found that batroxobin has good therapeutic effect in ischemic reperfusion rats and clinical practices in vivo. But we have not studied the neuroprotective effect of batroxobin on anoxic hippocampal neurons in vitro. The purpose of this study was to obtain further information on the mechanism of the batroxobin-induced neuroprotection and examine the neuroprotective effect on neurons exposed to anoxia. The effect of batroxobin on anoxic damages in cultured hippocampal neurons of neonatal rats was investigated by using morphological changes and heat shock protein 70 Kd (Hsp70) immunoreactive expression as indicators. The results indicate that batroxobin, besides its defibrination, may have a direct neuroprotective effect on anoxic damage of hippocampal neurons.

Effect of batroxobin on neuronal apoptosis during focal cerebral ischemia and reperfusion in rats

We have found that Batroxobin plays a protective role in ischemic brain injury, which attracted us to investigate the effect of Batroxobin on apoptosis of neurons during cerebral ischemia and reperfusion. The apoptotic cells in ischemic rat brains at different reperfusion intervals were tested with method of TdT-mediated dUTP-DIG nick end labeling (TUNEL) and the effect of Batroxobin on the apoptosis of neurons was studied in left middle cerebral artery (LMCA) occlusion and reperfusion in rat models (n = 18). The results showed that few scattered apoptosis cells were observed in right cerebral hemispheres after LMCA occlusion and reperfusion, and that a lot of apoptosis cells were found in left ischemic cortex and caudoputamen at 12 h reperfusion, and they reached peak at 24 h-48 h reperfusion. However, in the rats pretreated with Batroxobin, the number of apoptosis cells in left cerebral cortex and caudoputamen reduced significantly and the neuronal damage was much milder at 24 h reperfusion than that of saline-treated rats. The results indicate that administration of Batroxobin may reduce the apoptosis of neurons induced by cerebral ischemia and reperfusion and afford significant cerebroprotection in the model of focal cerebral ischemia and reperfusion.

Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin: a study by magnetic resonance imaging, 1H- and 31P-magnetic resonance spectroscopy

Metabolic changes in rats with photochemically induced cerebral infarction and the effects of batroxobin were investigated 1, 3, 5 and 7 days after infarction by means of magnetic resonance imaging (MRI), 1H- and 31P-magnetic resonance spectroscopy (MRS). A region of T2 hyperintensity was observed in left temporal neocortex in infarction group and batroxobin group 1, 3, 5 and 7 days after infarction. The volume of the region gradually decreased from 1 day to 7 days after infarction. The ratio of NAA/Cho + Cr in the region of T2 hyperintensity in the infarction group was significantly lower than that in the corresponding region in the sham-operated group 3, 5 and 7 days after infarction respectively (P < 0.05). Lac appeared in the region of T2 hyperintensity in the infarction group 1, 3, 5 and 7 days after infarction, but it was not observed in the corresponding region in sham-operated group at all time points. Compared with the sham-operated group, the ratios of beta ATP/PME + PDE and PCr/PME + PDE of the whole brain in the infarction group were significantly lower 1, 3 and 5 days after infarction respectively (P < 0.05), and the ratio of beta ATP/PCr also was significantly lower 1 day after infarction (P < 0.05). Batroxobin significantly decreased the volume of the region of T2 hyperintensity 1 and 3 days after infarction (P < 0.05), significantly increased the ratio of NAA/Cho + Cr in the region 5 and 7 days after infarction (P < 0.05), significantly decreased the ratios of Lac/Cho + Cr and Lac/NAA in the region 5 and 7 days after infarction (P < 0.05), and significantly increased the ratios of beta ATP/PME + PDE and beta ATP/PCr in the whole brain 1 day after infarction (P < 0.05). The results indicated that the infracted region had severe edema, increased Lac and apparent neuronal dysfunction and death, and energy metabolism of the whole brain decreased after focal infarction, and that batroxobin effectively ameliorated the above-mentioned abnormal changes.

Effects of batroxobin on spatial learning and memory disorder of rats with temporal ischemia and the expression of HSP32 and HSP70

The effect of Batroxobin on spatial memory disorder of left temporal ischemic rats and the expression of HSP32 and HSP70 were investigated with Morri's water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats in searching a goal were significantly longer than those of the sham-operated rats and at the same time HSP32 and HSP70 expression of left temporal ischemic region in rats was significantly increased as compared with the sham-operated rats. However, the mean reaction time and distance of the Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of HSP32 and HSP70 immune reactive cells of Batroxobin-treated rats was also less than that of the ischemic group. In conclusion, Batroxobin can improve spatial memory disorder of temporal ischemic rats; and the down-regulation of the expression of HSP32 and HSP70 is probably related to the attenuation of ischemic injury.

Efficacy and effect of SI17 therapy on pancreatic polypeptide in vascular and tension-type headache

BACKGROUND AND PURPOSE

Vascular and tension-type headache is most commonly encountered, and SI17 therapy has been tested to treat headache with good results. The efficacy of SI17 therapy for vascular and tension-type headache was compared and the effect of SI17 therapy on pancreatic polypeptide (PP) was studied.

MATERIALS AND METHODS

29 cases of vascular headache (20 cases in acute attack during the trial) and 27 cases of tension-type headache (19 cases in acute attack) were enrolled in the study. Plasma PP level before and 4th day after treatment was measured by radioimmunoassay.

RESULTS

SI17 therapy is better for the treatment of vascular headache. Vascular headache with higher PP level and tension-type headache with normal PP level had good therapeutic results.

CONCLUSION

The clinical efficacy is better for vascular headache with the increase of vagus tension and for tension-type headache with normal vagus tension.

Effect of batroxobin on expression of c-Jun in left temporal ischemic rats with spatial learning and memory disorder

The effect of Batroxobin on expression of c-Jun in left temporal ischemic rats with spatial memory disorder was investigated by means of Morri's water maze and immunohistochemistry methods. The results showed that the mean reaction time and distance of temporal ischemic rats for searching a goal were significantly longer than those of sham-operated rats, and at the same time c-Jun expression of left temporal ischemic region was significantly increased. However, the mean reaction time and distance of Batroxobin-treated rats were shorter and they used normal strategies more often and earlier than those of ischemic rats. The number of c-Jun immune reactive cells of Batroxobin-treated rats was also less than that of ischemic group. In conclusion, Batroxobin can improve spatial memory disorder in temporal ischemic rats, and the down-regulation of the expression of c-Jun is probably related to the neuroprotective mechanism.

[Determination of isofraxidin in Sarcandra glabra (Thunb.) Nakai by HPLC]

OBJECTIVE

To establish a method for the determination of isofraxidin in Sarcandra glabra.

METHOD

Using HPLC with mu-Bondapak C18 column, acetonitrile -0.1% phosphoric acid solution(20:80) as mobile phase and detection wavelength at 344 nm.

RESULT

The recovery and RSD were 98.1% and 1.9% (n = 5) respectively.

CONCLUSION

This method is rapid, simple and accurate, thus may be used for the quality control of this drug.

Effects of transient forebrain ischemia and radix Salviae miltiorrhizae (RSM) on extracellular levels of monoamine neurotransmitters and metabolites in the gerbil striatum--an in vivo microdialysis study

The aim of this study was to investigate the effect of 30 min forebrain ischemia, followed by 120 min reperfusion on extracellular fluid (ECF) levels of dopamine (DA), norepinephrine (NE), serotonin (5-HT) and their metabolites, homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) in the striatum of gerbils, so as to obtain further information on the mechanism of Radix Salviae Miltiorrhizae (RSM)-induced neuroprotection. Microdialysis was used to sample the extracellular space. Dialysate was measured by high performance liquid chromatography with electrochemical detector (HPLC-ED). ECF DA, NE levels increased from basal levels by 282, 227 and 221 folds, by 9.14, 8.51 and 8.25 folds, respectively for the three ischemic duration (0-10; 11-20; 21-30 min). ECF DA, NE, 5-HT levels in the RSM-treated group were significantly decreased as compared with those in the control group during ischemia (P < 0.01). The results suggested that monoamine neurotransmitters were involved in ischemic neuron damage directly or indirectly; and that RSM plays a protective role during cerebral ischemia by attenuating the dysfunctions of monoamine neurotransmitters.

Effects of electro-acupuncture on somatostatin and pancreatic polypeptide in ischemic cerebrovascular diseases

The levels of somatostatin (SS) in CSF and blood and pancreatic polypeptide (PP) in plasma were measured by radioimmunoassay in 64 patients with acute ischemic cerebrovascular diseases (ICVD), randomly divided into two groups: group 1 (n = 31, both electro-acupuncture and routine treatments given) and group 2 (n = 33, routine treatment) and 26 non-ICVD patients were used as controls. The points of electro-acupuncture were Quchi (LI 12), Waiguan (SJ 5) and Huantiao (GB 30) and Zusanli (St 36). After a course of treatment, the SS levels in plasma and CSF were significantly increased in the patients of group 1 with good result and their plasma PP level had no significant change. In the patients with poor result, however, the PP level was significantly decreased. The results suggested that electro-acupuncture might play an active role in alleviating the SS metabolic disturbance in CNS of ICVD patients.

The effects of radix Salviae miltiorrhizae on lipid accumulation of peroxidized low density lipoprotein in mouse peritoneal macrophages--lipid analysis and morphological studies

Mouse peritoneal macrophages were incubated in DMEM with pox-LDL and Rradix Salviae Miltiorrhizae (RSM) to investigate the effects of RSM on the internalization of peroxidized low density lipoprotein (pox-LDL) by using lipid analysis and electron microscopy. Lipid peroxide (LPO) concentrations were increased slightly in the medium after incubation of macrophages with normal LDL (n-LDL), while decreased significantly in the media after incubation of macrophages with pox-LDL. In the three groups with pox-LDL, it could be found that there was a dose-dependent decrease of concentrations of LPO and total cholesterol (TCH) in the two RSM groups, and the decrease in the two RSM groups was much greater than in the group without RSM. RSM accelerated a more decrease of LPO than cholesterol contents in the media containing pox-LDL. The ultrastructural studies also showed that RSM induced the accumulation of lipid droplets in the cytoplasm of mouse peritoneal macrophages. The results suggested that RSM could accelerate the phagocytosis and degradation of pox-LDL by macrophages.

Effect of radix Salviae miltiorrhizae on the gene expression of nitric oxide synthase in ischemic rat brains

The effect of Radix Salviae Miltiorrhizae (RSM) on the gene expression of nitric oxide synthase (NOS) in rat brains during ischemia was studied with in situ hybridization and the results were analyzed with IBAS 2000 Image Analysis System. It was found that NOS gene expression of cerebral cortex and caudate-putamen was markedly increased in 24 hours in ischemia group (P < 0.01). In RSM-treated rats, although the NOS gene expression of ischemic side was also increased as compared with contralateral cortex and caudate-putamen, it was significantly lower in RSM-treated rats than those of the controls (P < 0.05, P < 0.01). The present study indicates that RSM can partly inhibit NOS gene expression of cerebral cortex and caudate-putamen during ischemia. This may be one of the protective mechanisms of RSM on cerebral ischemia.

[Quantitative determination of extracellular glutathione and cysteine in gerbil brain by microdialysis and high performance liquid chromatography with electrochemical detection]

A method for the determination of glutathione and cysteine in microdialysate by HPLC with electrochemical detector has been described. The column used was Hypersil ODS, 5 microns, 200 mm x 4.6 mm i.d. and mobile phase was 50% 0.2 mol/L KCl, 10.6% 0.2 mol/L HCl, 39.4% methanol and 0.1 mmol/L EDTA (pH 2.0) with a flow rate of 1 mL/min. The microdialysis probe (membrane: pc, length: 10 mm, diameter: 0.5 mm/CMA) was inserted into the right striatum of gerbil at the following coordinates: 1.5 mm anterior and 1.5 mm lateral to bregma, and 3.5 mm below dura. Electrochemical pretreatment of a glassy carbon electrode used as a working electrode in an electrochemical detector has been found to enhance the analytical capability of detector for the determination of glutathione and cysteine. The quantitative determination was made with an electrochemical detector at 0.9 V and by external standard method. The method gave good recoveries and reproducibilities. The average recoveries of two analytes were 91.4% and 87.3% respectively. Extracellular fluid glutathione and cysteine concentrations in the striatum of gerbil brain were determined by the microdialysis and chromatography described in this study. The contents of Cys and GSH in microdialysate of gerbil striatum were 65.54 +/- 12.96 nmol/L and 68.59 +/- 13.23 nmol/L. The results were comparable with those reported in previous works.

Radix Salviae miltiorrhizae protects rat hippocampal neuron in culture from anoxic damage

Radix Salviae Miltiorrhizae (RSM), a well-known traditional Chinese medicinal herb, has been used to improve blood circulation and resolve blood stasis. We have previously found that RSM has neuroprotective effect on ischemia and/or ischemia-reperfusion rats. The purpose of this study was to obtain further information on the mechanism of the RSM-induced neuroprotection and to examine the neuroprotective effect on neurons exposed to anoxia. The effect of RSM on anoxic damage in cultured hippocampal neurons of neonatal rat was investigated by using morphological changes and heat shock protein 70 kD (HSP70) expression as indicators. RSM given 0.5 h before 2 h-anoxia followed by 48 hours reoxygenation could significantly increase survival rate of hippocampal neurons and number of HSP70 positive cells. The results suggest that RSM has a direct neuroprotective effects on anoxic damage in hippocampal neurons.

[The changes of vasoactive intestinal peptide somatostatin and pancreatic polypeptide in blood and CSF of acute cerebral infarction patients and the effect of acupuncture on them]

VIP, SS and PP which exist in gastrointestinal tract and CNS might be to play an important role in nervous system as neurotransmitters of neuromediaters. There have been a few of reports about their changes in plasma and CSF in ICVD. The effects of acupuncture, which was used in treatment of ICVD with good efficiency, on VIP, SS and PP have not been known. For researching their changes in ICVD and effects of electro-acupuncture on them, and finding the mechanism of acupuncture in treatment of ICVD, the study was performed. The levels of VIP, SS and PP in 64 patients with acute cerebral infarction were determined. The points of acupuncture were Quchi (LI 12), Waiguan (SJ 5), Huantiao (BG 30), and Zusanli (ST 36). The routine treatment included dextran, nicotinic acid, aspirin, dipyridamole and radix salviae miltiorrhizae composita. The CSF and blood were taken before the begining of treatments and after a course of treatment. The level of VIP, SS and PP were measured by radiommunoassay. Results showed the level of CSF VIP in the patients was significantly lower as compared with controls. The level of plasma SS in the patients was lower, but the difference was not significant as compared with controls, and level of plasma PP in the patients was significantly increased when it was compared with controls. After electro-acupuncture treatment, in patients with good efficiency, CSF VIP recovered to normal level and the levels of plasma and CSF SS were significantly increased, while the level of plasma PP had no significant change. The results suggest that acupuncture might regulate the disturbances of metabolism of VIP and SS in CNS.

Effect of acupuncture on vasoactive intestinal peptide in ischemic cerebrovascular diseases

BACKGROUND AND PURPOSE

Vasoactive intestinal peptide (VIP) appears to play an important role as a neurotransmitter or neuromediater in ischemic cerebrovascular diseases (ICVD). The effect of acupuncture, which is used in treatment of ICVD with good efficiency, on VIP has not been known. For finding the mechanism of acupuncture in treatment of ICVD and the effect of electro-acupuncture on VIP, the present study was performed.

MATERIALS AND METHODS

59 patients with acute ICVD were randomly divided into two groups. Electro-acupuncture and routine treatment were given in Group 1 (n = 29), and routine treatment was used alone in Group 2 (n = 30). The cerebrospinal fluid (CSF) and blood were taken before the beginning of treatment and after a course of treatment in both groups. The control group consisted of 38 cases of non-ICVD. VIP was measured by radioimmunoassay.

RESULTS

The level of CSF VIP in patients with acute ICVD was significantly lower than that in the controls, while the levels of plamsa VIP showed no significant difference between the ICVD and control groups, and the level of CSF VIP was not significantly correlated with the level of plasma VIP. After acupuncture treatment, the level of CSF VIP was increased and showed no significant difference as compared with the control group.

CONCLUSION

Acupuncture might alleviate the disturbance of metabolism of VIP in CNS.

Protective effect of radix Salviae miltiorrhizae on apoptosis of neurons during focal cerebral ischemia and reperfusion injury

We have found that Radix Salviae Miltiorrhizae (RSM) plays a protective role in ischemic brain injury, which attracted us to investigate the effect of RSM on apoptosis of neurons during cerebral ischemia and reperfusion. The apoptotic cells in ischemic brains at different reperfusion intervals were tested with the method of TdT-mediated dUTP-DIG nick end labeling (TUNEL), and the effect of RSM on the apoptosis of neurons was studied in left middle cerebral artery (LMCA) occlusion in rat models (n = 18). The results showed that few scattered apoptotic cells were observed in right cerebral hemisphere after LMCA occlusion and reperfusion, and that a lot of apoptotic cells were found in left ischemic cerebral cortex and caudoputamen at 12 h reperfusion, and they reached peak at 24-48 h reperfusion. However, in rats pretreated with RSM, the number of apoptotic cells in left cortex and caudoputamen reduced significantly and the neuronal damage was much milder at 24 h reperfusion as compared with those of saline-treated rats. From this study, we conclude that administration of RSM can reduce the apoptotic of neurons induced by cerebral ischemia and reperfusion and afford significant cerebroprotection in the model of focal cerebral ischemia and reperfusion.

Effect of radix Salviae miltiorrhizae on extracellular adenosine and evaluation of its protective efficacy in ischemic reperfusion rat--microdialysis, HPLC and histopathologic studies

The effects of Radix Salviae Miltiorrhizae (RSM) on extracellular adenosine (Ade) and its metabolites, i.e. inosine, hypoxanthine and xanthine, were studied with microdialysis and HPLC techniques during cerebral ischemia-reperfusion induced by 4-vessel occlusion in rat brain. Histological examination of hippocampus was performed 6 h after reperfusion. ECF (extracellular fluid) adenosine and its metabolites were compared between the controls (n = 6) and RSM-treated rats (n = 6). Basal level of Ade and its metabolites release were not greatly affected by pretreatment with RSM, and no significant difference as compared with the sham-operated (n = 6). Ade and its metabolites were dramatically increased after ischemia, and decreased near basal-level and its metabolites remained high at the end of reperfusion. In the RSM-treated animals, the tendency of changes of Ade and its metabolites was just the same as in the controls, but the magnitudes of changes were significantly lower at some different time points. In sham-operated animals, no changes were observed at different time points both during ischemia (30 min.) and reperfusion (60 min.). Histopathological findings demonstrated that RSM pretreatment results in better histologic preservation of the pyramidal cells in the postischemic reperfusion CA1 sector both qualitatively and quantitatively. These results indicated that RSM protects against cerebral ischemia reperfusion injury.

[The role of adenosine in the early stage of anoxia of hippocampal slices and its mechanisms]

The role of adenosine in reversible inhibition of synaptic function during the early stage of anoxia and its mechanisms were investigated with extracellular recording technique in rat hippocampal slices. The results showed that acute anoxia led to the reversible inhibition of synaptic function, which is similar to the response to addition of high concentration of exogenous adenosine. The reversible inhibition could be suppressed by adenosine A1 receptor antagonist CPT and potassium channel blocker 4-AP, whereas TEA and ATP-sensitive potassium channel blocker glipzide had no effect. These results suggest that during the early stage of anoxia, the enhanced release of endogenous adenosine can inhibit the synaptic transmission by activating 4-AP-sensitive potassium channels via A1 receptors and thus play a role in protenction against anoxic injury. ATP-sensitive potassium channels may not be involved in the mechanisms of adenosine action.

ET-1 gene expression of rat brain during ischemia and reperfusion and the protective effect of radix Salviae miltiorrhizae

Endothelin-1 (ET-1) gene expression of rat brain during ischemia and reperfusion as well as the effect of Radix Salviae Miltiorrhizae (RSM) were studied with in situ hybridization. It was found that ET-1 gene expression of cerebral cortex and caudate-putamen was markedly increased both in 24 hours of ischemia and 24 hours of reperfusion groups (P < 0.01, P < 0.05). In RSM-treated rats, although the ET-1 gene expressions of ischemia and reperfusion sides were also increased as compared with contralateral cortex and caudate-putamen, they were significantly lower in RSM-treated rats than those of controls (P < 0.05, P < 0.01 respectively). The present study indicated that RSM can partly inhibit ET-1 gene expression of cerebral cortex and caudate-putamen during ischemia and reperfusion. This may be one of the protective mechanisms of RSM on cerebral ischemia and reperfusion.

Inhibitory effect of 764-3 on Ca2+ uptake in rat brain synaptosomes

In an attempt to examine the effect of 764-3, a purified component extracted from Radix Salviae Miltiorrhizae (RSM), on calcium channel, Ca2+ uptake in rat brain synaptosome stimulated by high-K+ and Glutamate (Glu) was investigated by using radioisotope labeled 45CaCl2. It was found that 764-3 could decrease the uptake of Ca2+ induced by high-K+ (60 mM) and 0.1 mM glutamate in a concentration-dependent manner. The maximum inhibiting rates were 45.22 +/- 4.88% and 37.58 +/- 4.52%, respectively. The results indicated that neuroprotective effect of RSM on cerebral ischemic injury may be related to its blocking effects on calcium channel.

Changes of endothelin-1 gene expression in rat brains during ischemia and ischemic reperfusion

OBJECTIVE

The experiment was designed to study the association of cerebral ischemia and reperfusion with endothelin-1 (ET-1) gene expression of rat brains and time-dependent changes of ET-1 gene expression during cerebral ischemia.

MATERIALS AND METHODS

Thirty-three male SD rats were divided into dot blot hybridization (n = 27) and in situ hybridization groups (n = 6). The focal cerebral ischemia and reperfusion models were made with suture embolism of middle cerebral artery. Dot blot hybridization groups were redivided into control and ischemic subgroups (ischemia for 0.5, 1, 1.5, 3, 6, 12, 24, 48 and 72 h respectively). In situ hybridization groups were redivided into ischemia and reperfusion groups. After 24 h ischemia and 24 h reperfusion, ET-1 gene expressions were investigated with in situ hybridization and the results were analyzed with IBAS 2000 Image Analysis System.

RESULTS

Dot blot hybridization showed that ET-1 mRNA of cerebral cortex and caudate-putamen was increased at 6 h of ischemia and reached peak at 24 h (3.9 and 3.7 fold respectively), and at 72 h of ischemia it remained at high levels (3.5 and 2.1 fold respectively). In situ hybridization showed that the levels of ET-1 mRNA of cerebral cortex and caudate-putamen were also markedly increased both in 24 h ischemia and 24 h reperfusion groups (P < 0.01, P < 0.05 respectively).

CONCLUSIONS

ET-1 gene expression in focal ischemic brain tissue were markedly and progressively increased during cerebral ischemia and reperfusion and down-regulation of ET-1 gene expression may be a new approach to the treatment of ischemic cerebrovascular diseases.

Effect of radix Salviae miltiorrhizae on nitric oxide in cerebral ischemic-reperfusion injury

It has been postulated that nitric oxide (NO) is produced in significant amount on reperfusion of ischemic brain and could cause brain edema and cell death. This study was undertaken in an attempt to determine whether Radix Salviae Miltiorrhizae (RSM) could reduce cerebral NO contents in 4-vessel occlusion rat model after 30 min of global ischemia and 15 min of reperfusion. There was a significant increase in cerebral NO level in untreated animals as compared with sham-operated ones. By pretreatment with RSM the cerebral NO concentration was reduced to normal level. The possibilities of neuroprotective role of RSM in cerebral ischemic-reperfusion injury were discussed.

Radix Salviae miltiorrhizae treatment results in decreased lipid peroxidation in reperfusion injury

In our pervious investigations we have found that Radix Salviae Miltiorrhizae (RSM) can reduce neurological deficits and ameliorate cellular damages, and its protective actions are associated with its effects on cerebral edema, monoamines, neuropeptides, neurotransmitter aminoacids, thromboxane A2, peroxidation and down-regulation of c-fos gene expression in ischemic animals. The purpose of present study was to investigate the protective effect of RSM against lipid peroxidation in 4-vessel occlusion and reperfusion rat model. We found that in RSM-treated rats the cerebral SOD activity is significantly increased, while the cerebral MDA level is significantly decreased when compared with untreated animals. The results suggested that RSM can reduce the lipid peroxidation and afford cerebroprotection against reperfusion injury.

Studies of Qingyangshen (II): modulatory effect of co-treatment with qingyangshen and diphenylhydantoin sodium on rat hippocampal c-fos expression during seizures

We have reported that, after KA treatment in rats, there was first a significant increase in hippocampal c-fos expression during acute seizures and then a long-term inhibition in hippocampal c-fos expression during chronic seizures. In this experiment, we examined the modulatory effect of Qingyangshen (QYS), a traditional Chinese medicine with antiepileptic property, and diphenylhydantoin sodium (DPH) on hippocampal c-fos expression during seizures. We found that after intraperitoneal injection of QYS + DPH (15 mg/kg and 50 mg/kg respectively, q.o.d. x 6), the peak level of hippocampal c-fos mRNA induction during KA-induced acute seizures was reduced by 56.27%; while the inhibition of hippocampal c-fos expression during KA-induced chronic seizures was disinhibited to control level. It is suggested that the inhibitory effect of QYS + DPH on KA-induced seizures, chronic seizures in particular, may have much to do with its modulatory effect on hippocampal c-fos expression.

Batroxobin accelerates lipid accumulation of peroxidized low density lipoprotein in mouse peritoneal macrophages

Mouse peritoneal macrophages were incubated in DMEM medium with batroxobin (DF-521) to determine the effect of batroxobin on the internalization of peroxidized low-density lipoprotein (pox-LDL) by transmission electron microscopy. Although the morphology of the mouse peritoneal macrophages after incubation with DMEM, normal LDL (n-LDL) and n-LDL plus batroxobin was similar to that of the cells before incubation, they exhibited numerous cytoplasmic lipid droplets after incubation with pox-LDL for 4 h. After addition of batroxobin to the medium containing pox-LDL, the production of lipid droplets in the mouse peritoneal macrophages was tremendously accelerated. Batroxobin accelerates the phagocytosis and degradation of pox-LDL by macrophages.

Studies of qingyangshen (I): Differential expression of hippocampal c-fos proto-oncogene during kainic acid induced acute and chronic seizures

We previously reported that Qingyangshen (QYS), a traditional Chinese medicine with antiepileptic property, had therapeutic effect on kainic acid (KA) induced experimental seizures (see JTCM 13 (4): 281-286, 1993 for reference). To investigate the mechanisms underlying the anticonvulsant action of QYS, we analyzed the modulatory effect of QYS on rat hippocampal c-fos proto-oncogene expression during KA-induced epileptogenesis in this and the following paper. The expression of hippocampal c-fos gene during KA-induced seizures were examined first. Rats were intraperitoneally injected with kainic acid (KA, 12 mg/kg) and hippocampal c-fos mRNA level was determined by Northern blot analysis during both acute (within one day after KA injection) and chronic (15 days after KA treatment) seizures. A mild increase in hippocampal c-fos mRNA level was observed 30 min after KA injection (being 1.98 +/- 0.70 times of control level), which corresponded temporally to the occurrence of the first limbic seizures. There was an 11.02 +/- 3.33 fold maximal induction of c-fos mRNA at 2 h after KA administration, which remained relatively stable even when behavioral seizures continued to aggravate 4 h after KA treatment. Twelve hours after KA administration, c-fos mRNA in the hippocampus returned to control level when acute seizures began to gradually disappear. In contrast, the induction of hippocampal c-fos mRNA during chronic seizures was inhibited significantly, being reduced by 55.40% compared to control. This suggested that c-fos is in different functional states at acute and chronic stages of epileptogenesis induced by KA.

Anti-inflammatory effects of tianrong acupoint on blood vessels of dura mater

Although Tianrong acupoint (SI 17) is used for migraine headache, its mechanism of action remains obscure. The effects of Tianrong acupoint therapy on neurogenically-mediated plasma protein extravasation (125I-BSA) in rat dura mater induced by electrical stimulation of the right trigeminal ganglion was studied. When the unilateral trigeminal ganglion was stimulated (5 Hz, 1.2 mA, 5 msec for 5 min), the ratio of stimulated side/unstimulated side (cpm/mg) was 1.6663 +/- 0.0217. The plasma extravasation was blocked by different kinds of treatment in different degrees. The order of the ratio was as follow: Tianrong acupoint therapy (1.0917 +/- 0.0266) and Tianrong electrical needle therapy (1.1281 +/- 0.0227) < Tianrong acupoint injection with normal saline (1.325 +/- 0.0444) < Quchi acupoint (LI 11) injection with prednisolonum (1.5284 +/- 1.1624). The results indicated that Tianrong acupoint therapy could inhibit the neurongenic inflammation on the affected side.

Protective effect of radix Salviae Miltiorrhizae Composita on cerebral ischemia

The protective effects of Radix Salviae Miltiorrhizae Composita (RSMC) on cerebral ischemia in gerbils produced by unilateral ligation of left common carotid artery and on the development of ischemic cerebral edema were studied. It was found that the administration of RSMC resulted in a very significant decrease in neurological deficits and the time for exhibiting first signs of neurological deficit delayed compared with untreated animals. Although the values of specific gravity of fresh cerebral tissue on the ligated side of common carotid artery in untreated animals (1.0406 +/- 0.0039 SD) and in RSMC-treated animals (1.0453 +/- 0.0009) were decreased significantly compared to that (1.0468 +/- 0.0003) of sham-operated animals, the specific gravity of cerebral tissue in RSMC-treated animals was significantly heavier than that in untreated animals (t = 5.5022, P < 0.001), i.e. the administration of RSMC decreased the severity of cerebral edema. A significant negative correlation was found between stroke index and specific gravity, and it suggests that one of the protective mechanisms of RSMC might be related to its ameliorating cerebral edema.

The effect of radix salviae miltiorrhizae composita and ligustrazine on lipid peroxidation in low density lipoprotein due to copper dichloride

It is well known that lipid peroxide in low density lipoprotein (LDL) plays an important role in atherosclerosis and atherosclerotic diseases. We used oxidized LDL generated by incubating LDL from healthy persons with copper dichloride as a model to investigate the anti-lipid-peroxide property of Radix Salviae Miltiorrhizae Composita (RSMC) and ligustrazine. The changes in concentrations of lipid peroxide and lipids in LDL due to Cu++ were studied, and the effects of RSMC and ligustrazine on the changes were studied. The results in our study indicate that RSMC has a potential role on anti-lipid-peroxidation, but it was not found that ligustrazine has similar anti-peroxidation action.

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.

Effect of radix salviae miltiorrhizae on EAA and IAA during cerebral ischemia in gerbils: a microdialysis study

The concentrations of amino acids (AA), stroke index and infarct area were determined in 26 gerbils which were divided into 3 groups: RSM-treated (n = 8), Saline-treated (n = 10) and sham-operated (n = 8). The levels of AA were measured with microdialysis technique in cerebral cortex. The concentrations of neurotransmitter AA, as Glu and GABA and Asp, were significantly increased during the first 60 min after CCA ligation, while the concentrations of non-neurotransmitter AA, as Thr and Ser, had no significant changes. In RSM-treated gerbils, the level of Glu was significantly lower than that of the saline-treated, but the GABA in RSM-treated was significantly higher than that of the saline-treated. The ratio of Glu/GABA was significantly decreased after ischemia. The RSM could improve the reduction of ratio of Glu/GABA during 0-30 min and 91-120 min after cerebral ischemia. There were statistically significant decrease in terms of stroke index in RSM-treated group when compared with saline-treated group at 24 h and 16 h after CCA ligation respectively. The RSM has a tendency to decrease the size of infarct area, but no statistical difference. The results suggest that the neurotransmitter AA involve in the pathophysiological procedures of cerebral ischemia and the RSM can attenuate dysfunctions of EAA and IAA. Furthermore, the results also imply that there may be an alternate way to treat cerebral ischemia by inhibiting the presynaptic releasing of Glu and stimulating the releasing of GABA.

Effect of qingyangshen on hippocampal alpha- and beta-tubulin gene expression during kainic acid induced epileptogenesis

Using alpha- and beta- tubulin cDNA Probes and Northern blot hybridization technique, we analyzed the effect of intraperitoneally injected Qingyangshen (QYS), a traditional Chinese medicine with antiepileptic property, and diphenylhydrantoin sodium (DPH) on hippocampal alpha- and beta-tubulin gene expression during kainic acid (KA) induced chronic seizures. It was found that: 1) thirty days after intraperitoneal injection of KA, alpha- and beta-tubulin mRNAs in animals showing chronic seizures increased 3.02 +/- 1.05 and 4.07 +/- 1.32 times respectively compared with control; 2) neither QYS (15 mg/kg, q.o.d. x 6) nor DPH (50 mg/kg, q.o.d. x 6), when used separately, could inhibit the above mentioned effect of KA; 3) when QYS (15 mg/kg, q.o.d. x 6) and DPH (50 mg/kg, q.o.d. x 6) were given in combination, the long-term increase in tubulin gene expression induced by KA was significantly reduced, with alpha- and beta-tubulin mRNAs being decreased to 0.44 +/- 0.08 and 0.50 x 0.10 times of corresponding values in animals treated with KA alone. The results indicate that the mechanism of antiepileptic effect of QYS is at least partially related to the inhibition of tubulin synthesis and subsequent reduction in mossy fiber sprouting and neosynaptogenesis.