Effect of dexmedetomidine on rats with convulsive status epilepticus and association with activation of cholinergic anti-inflammatory pathway.

Convulsive status epilepticus (CSE) is a neurological disease with contraction and extension of limbs, leading to damage of hippocampus and cognition. This study aimed to explore the effects of dexmedetomidine (DEX) on the cognitive function and neuroinflammation in CSE rats. All rats were divided into control group, CSE group and DEX group. Morris water maze test was used to measure cognitive function. Acute hippocampal slices were made to detect long-term potentiation (LTP). Immunohistochemistry was used to determine the expression of α7-nicotinic acetylcholine receptor (α7-nAChR) and interleukin-1ß (IL-1ß). Enzyme-linked immunosorbent assay (ELISA) was used to measure serum levels of IL-1ß, tumor necrosis factor-α (TNF-α), S-100ß and brain-derived neurotrophic factor (BDNF). Our results showed that DEX improved the memory damage caused by CSE. DEX reduced seizure severity and increased the amplitudes and sustainable time of LTP, and also inhibited the hippocampal expression of α7-nAChR and IL-1ß in CSE rats. DEX treatment decreased serum IL-1ß, TNF-α and S-100ß levels and increased BDNF levels. The effects of DEX on seizure severity and LTP could be simulated by nicotine or attenuated by concurrent α-bungarotoxin (α-BGT) treatment. In conclusions, DEX significantly improved spatial cognitive dysfunction, reduced seizure severity and increased LTP in CSE rats. Improvements by DEX were closely related to enhancement of cholinergic anti-inflammatory pathway.

Benzothiadiazole and B-Aminobutyricacid Induce Resistance to Ectropis Obliqua in Tea Plants (Camellia Sinensis (L.) O. Kuntz).

In order to investigate the effect of benzothiadiazole (BTH) and ß-aminobutyric acid (BABA) on the resistance of tea plants (Camellia sinensis) to tea geometrid (Ectropis obliqua), three levels each of benzothiadiazole (BTH) and ß-aminobutyric acid (BABA) were sprayed on 10-year-old tea plants. Generally PPO and PAL activities increased with low concentrations of BTH and BABA treatments. Quantitative RT-PCR revealed a 1.43 and 2.72-fold increase in PPO gene expression, and 3.26 and 3.99-fold increase in PAL gene expression with 75 mg/L BTH and 400 mg/L BABA respectively. Analysis of hydrolysis of synthetic substrates also revealed that chymotrypsin-like enzyme activity present in larval midgut extracts was not significantly inhibited by BTH and BABA. However, proteinase activity was found to be inversely proportional to the age of tea geometrid. Larvae pupation rate decreased by 8.10, 10.81 and 21.62% when tea geometrid were fed with leaves treated with 25, 50 and 75 mg/L BTH solutions, while 100, 200 and 400 mg/L BABA solutions decreased same by 8.10, 16.21 and 13.51% respectively. Also, larvae development period delayed to 23.33 and 26.33 days with 75 mg/L BTH and 400 mg/L BABA treatments respectively. The results in this study; therefore, suggest that benzothiadiazole (BTH) and ß-aminobutyric acid (BABA) play a role in inducing resistance in tea plants to tea geometrid, with the optimal effect achieved at BTH-3 (75 mg/L) and BABA-3 (400 mg/L), respectively.

Value of 3D Pseudo-continuous Arterial Spin Labeling Magnetic Resonance Perfusion Imaging in Evaluating Posterior Circulation Ischemia in the Elderly.

Objective To investigate the value of 3D pseudo-continuous arterial spin labeling (3D-pCASL) magnetic resonance perfusion technique in evaluating posterior circulation ischemia (PCI) of the elderly beyond 80 years old and to offer the evidence of PCI of the elderly for clinical diagnosis. Methods Totally 53 male subjects older than 80 years were recruited in this study,including 20 subjects with clinically diagnosed PCI and 33 normal subjects. All the subjects underwent routine brain magnetic resonance imaging and 3D-pCASL sequence on a 3.0T magnetic resonance imaging system with 8 channel brain coil. Two post-labeling delay (PLD) time (PLD=1525 ms and PLD=2525 ms) of 3D-pCASL were used in this study to increase the accuracy of cerebral blood flow (CBF) change of posterior circulation region. We used SPM12 software to measure mean CBF values of bilateral occipital lobes and bilateral cerebellums. Independent sample t-test and rank-sum test were performed to evaluate the difference of CBF changes of anterior circulation and posterior circulation in two groups at two PLD time,the difference of CBF changes of bilateral occipital lobes and bilateral cerebellums in two groups of two PLD time,and the difference of increment of CBF between two PLD interval between two groups. Results In case group,the CBF value of the anterior circulation was significantly higher than that of posterior circulation at both two PLD time points (PLD=1525 ms and PLD=2525 ms)(P=0.000,P=0.000);in control group,the CBF value of the anterior circulation was significantly higher than that of the posterior circulation only at PLD=1525ms (P=0.025). The CBF values at bilateral occipital lobes and bilateral cerebellums at two PLD time points (PLD=1525 ms and PLD=2525 ms) were significantly higher in case group than in control group(P=0.003,P=0.002,P=0.000,P=0.001,P=0.000,P=0.001,P=0.002,P=0.014,respectively). Compared with the control group,the difference was statistically significant in bilateral occipital lobes and cerebellums with a smaller △CBF between two PLD interval in case group (P=0.004,P=0.001,P=0.001,P=0.025). Conclusion Multiple PLD time points need to be used in 3D-pCASL in diagnosing PCI of the elderly because the posterior circulation is slow in these patients. 3D-pCASL technique is sensitive in detecting decreased CBF in posterior circulation and therefore can be used to predict posterior circulation stroke in the elderly.

Role of voltage gated Ca2+ channels in rat visceral hypersensitivity change induced by 2,4,6-trinitrobenzene sulfonic acid.

BACKGROUND: Visceral pain is common symptom involved in many gastrointestinal disorders such as inflammatory bowel disease. The underlying molecular mechanisms remain elusive. We investigated the molecular mechanisms and the role for voltage gated calcium channel (VGCC) in the pathogenesis in a rat model of 2,4,6-trinitrobenzenesulfonic acid (TNBS) induced visceral inflammatory hypersensitivity. RESULTS: Using Agilent cDNA arrays, we found 172 genes changed significantly in dorsal root ganglia (DRG) of TNBS treated rats. Among these changed genes, Cav1.2 and Cav2.3 were significantly up-regulated. Then the RT-PCR and Western blot further confirmed the up-regulation of Cav1.2 and Cav2.3. The whole cell patch clamp recording of acutely dissociated colonic specific DRG neurons showed that the peak IBa density was significantly increased in colonic neurons of TNBS treated rats compared with control rats (-127.82 ± 20.82 pA/pF Vs -91.67 ± 19.02 pA/pF, n = 9, *P < 0.05). To distinguish the different type of calcium currents with the corresponding selective channel blockers, we found that L-type (-38.56 ± 3.97 pA/pF Vs -25.75 ± 3.35 pA/pF, n = 9, * P < 0.05) and R-type (-13.31 ± 1.36 pA/pF Vs -8.60 ± 1.25 pA/pF, n = 9, * P < 0.05) calcium current density were significantly increased in colonic DRG neurons of TNBS treated rats compared with control rats. In addition, pharmacological blockade with L-type antagonist (nimodipine) and R-type antagonist (SNX-482) with intrathecal injection attenuates visceral pain in TNBS induced inflammatory visceral hypersensitivity. CONCLUSION: Cav1.2 and Cav2.3 in colonic primary sensory neurons play an important role in visceral inflammatory hyperalgesia, which maybe the potential therapeutic targets.

Genome-wide identification and characterization of PIN-FORMED (PIN) and PIN-LIKES (PILS) gene family reveals their role in adventitious root development in tea nodal cutting (Camellia Sinensis).

Auxin affects all aspects of plant growth and development, including morphogenesis and adaptive responses. Auxin transmembrane transport is promoted by PIN formation (PIN) and a structurally similar PIN-like (PILS) gene family, which jointly controls the directional transport of the auxin between plant cells, and the accumulation of intracellular auxin. At present, there is no study investigating the roles of CslPIN and CslPILS gene family in root development in the tea plant (Camellia sinensis). In this study, 8 CslPIN and 10 CslPILS genes were identified in the tea plant, and their evolutionary relationships, physical and chemical properties, conserved motifs, cis-acting elements, chromosome location, collinearity, and expression characteristics were analyzed. The mechanism of CslPIN and CslPILS in the formation of tea adventitious roots (ARs) was studied by the AR induction system. Through functional verification, the regulation of CslPIN3 gene on root growth and development of tea plant was studied by over-expression of CslPIN3 in Arabidopsis thaliana and in situ hybridization in Camellia sinensis. The results confirmed CslPIN3 was involved in the regulation of root growth and development as well as auxin accumulation. This study provides a better insight into the regulatory mechanism of CslPIN and CslPILS gene family on the formation of AR in tea plant.

Intracellular regions of the Eag potassium channel play a critical role in generation of voltage-dependent currents.

Folding, assembly, and trafficking of ion channels are tightly controlled processes and are important for biological functions relevant to health and disease. Here, we report that functional expression of the Eag channel is temperature-sensitive by a mechanism that is independent of trafficking or surface targeting of the channel protein. Eag channels in cells grown at 37 °C exhibit voltage-evoked gating charge movements but fail to conduct K(+) ions. By mutagenesis and chimeric channel studies, we show that the N- and C-terminal regions are involved in controlling a step after movement of the voltage sensor, as well as in regulating biophysical properties of the Eag channel. Synthesis and assembly of Eag at high temperature disrupt the ability of these domains to carry out their function. These results suggest an important role of the intracellular regions in the generation of Eag currents.

Voltage-gated potassium channels in IB4-positive colonic sensory neurons mediate visceral hypersensitivity in the rat.

OBJECTIVES: Irritable bowel syndrome (IBS) is associated with a state of chronic visceral hypersensitivity, but the underlying molecular mechanisms of visceral hyperalgesia remain elusive. This study was designed to examine changes in the excitability and alterations of voltage-gated K+ currents in subpopulations of colonic dorsal root ganglion (DRG) neurons in a rat model of IBS-like visceral hypersensitivity. METHODS: The model of IBS-like visceral hypersensitivity was induced by intracolonic infusion of 0.5% acetic acid (AA) in saline from postnatal days 8 -21. Experiments were conducted when rats became adults. DRG neurons innervating the colon were identified by 1,1'-dioleoyl-3,3,3',3-tetramethylindocarbocyanine methanesulfonate (DiI) fluorescence labeling and were immunostained for isolectin B4 (IB4) binding to classify these colonic neurons. Patch-clamp recordings were made from acutely dissociated DiI-labeled DRG neurons, and the expression of K+ channel in L6-S2 DRG was examined by reverse transcription-polymerase chain reaction (RT-PCR) and western blot. RESULTS: (1) Neonatal AA treatment induced long-lasting visceral hypersensitivity without significant inflammation but with mast cell hyperplasia. (2) Colonic DRG neurons contained IB4-positive and negative neurons with different electrophysiological properties. IB4-positive colonic neurons have longer action potentials (APs) and larger A-type K+ currents (I(A)) than the IB4-negative neurons, and IB4 phenotypic changes of colonic neurons were not involved in the chronic visceral hypersensitivity. (3) Neonatal AA treatment decreased I(A) density and changed the electrophysiological properties of I(A) and I(K) by shifting the steady-state inactivation toward a negative direction in IB4-positive colonic neurons. The excitability of these cells increased. (4) Kv4.3 was downregulated in neonatal AA-treated rats compared with control rats, which suggests a possible mechanism regarding the changes in electrical activity of DRG neurons in these rats. CONCLUSIONS: A new model for chronic visceral hypersensitivity following a diluted AA stimulus in the neonatal period is described. The hypersensitivity may be associated with mast cell hyperplasia in the colon and increased excitability of IB4-positive colonic neurons as a result of suppression of I(A) density and a shift in the inactivation curves of I(A) and I(K) in a hyperpolarizing direction in these cells. This study identifies for the first time a specific molecular mechanism in subpopulations of colonic DRG neurons that underlies chronic visceral hypersensitivity.

A Novel Approach Based on Bipartite Network Recommendation and KATZ Model to Predict Potential Micro-Disease Associations.

Accumulating evidence indicates that the microbes colonizing human bodies have crucial effects on human health and the discovery of disease-related microbes will promote the discovery of biomarkers and drugs for the prevention, diagnosis, treatment, and prognosis of diseases. However clinical experiments of disease-microbe associations are time-consuming, laborious and expensive, and there are few methods for predicting potential microbe-disease association. Therefore, developing effective computational models utilizing the accumulated public data of clinically validated microbe-disease associations to identify novel disease-microbe associations is of practical importance. We propose a novel method based on the KATZ model and Bipartite Network Recommendation Algorithm (KATZBNRA) to discover potential associations between microbes and diseases. We calculate the Gaussian interaction profile kernel similarity of diseases and microbes based on validated disease-microbe associations. Then, we construct a bipartite graph and execute a bipartite network recommendation algorithm. Finally, we integrate the disease similarity, microbe similarity and bipartite network recommendation score to obtain the final score, which is used to infer whether there are some novel disease-microbe interactions. To evaluate the predictive power of KATZBNRA, we tested it with the walk length 2 using global leave-one-out cross validation (LOOV), two-fold and five-fold cross validations, with AUCs of 0.9098, 0.8463 and 0.8969, respectively. The test results also show that KATZBNRA is more accurate than two recent similar methods KATZHMDA and BNPMDA.

Immunization with recombinant Nogo-66 receptor (NgR) promotes axonal regeneration and recovery of function after spinal cord injury in rats.

Nogo-66 receptor (NgR), a common receptor for the three known myelin-associated inhibitors, i.e., Nogo-A, myelin-associated glycoprotein (MAG), and oligodendrocyte myelin glycoprotein (OMgp), plays a key role in the failure of axonal regeneration in the adult mammalian central nervous system (CNS). Here we report a novel vaccine approach that stimulates the production of anti-NgR antibody to overcome NgR-mediated growth inhibition after spinal cord injury (SCI). We showed that adult rats immunized with recombinant NgR produced high titers of the anti-NgR antibody and that antisera obtained from the immunized rats promoted neurite outgrowth of rat cerebellar neurons on the inhibitory MAG substrate in vitro. In a spinal cord dorsal hemisection model, NgR immunization promoted regeneration of lesioned corticospinal tract (CST) axons, anterogradely labeled with biotin dextran amine (BDA), beyond the lesion site. In a contusive SCI model, NgR immunization markedly reduced the total lesion volume and improved Basso, Beattie, and Bresnahan (BBB) locomotor rating scale and grid walking performance. Thus, the NgR vaccine approach may represent a promising repair strategy to promote structural and functional recovery following SCI.

[Feasibility of non-contrast enhanced magnetic resonance angiography for diagnosis of renal artery stenosis in elderly patients].

OBJECTIVE: To evaluate the diagnostic efficacy of IFIR-FIESTA technique in detecting renal artery stenosis in elderly patients. METHODS: Twenty-seven aged patients underwent both IFIR-FIESTA and 3D CE-MRA examinations. The imaging quality and renal artery stenosis grades were evaluated. Kappa test was used to assess the consistency between the two methods. With CE-MRA as the reference, the diagnostic sensitivity, specificity, accuracy, PPV and NPV for IFIR-FIESTA were calculated in detecting renal artery stenosis. RESULTS: The images by the two methods were 100% qualified for diagnosis, although the image quality of CE-MRA was significantly better. IFIR-FIESTA and CE-MRA showed excellent consistency in detecting renal artery stenosis. With CE-MRA as the reference, the diagnostic sensitivity, specificity, accuracy, PPV and NPV for IFIR-FIESTA were 97.1%, 100%, 98.1%, 100%, and 95% in detecting renal artery stenosis, respectively. CONCLUSION: IFIR-FIESTA is feasible as a routine examination for detecting renal artery stenosis in elderly patients.

Intracellular linkers are involved in Mg2+-dependent modulation of the Eag potassium channel.

Modulation of activation kinetics by divalent ions is one of the characteristic features of Eag channels. Here, we report that Mg(2+)-dependent deceleration of Eag channel activation is significantly attenuated by a G297E mutation, which exhibits a gain-of-function phenotype in Drosophila by suppressing the effect of shaker mutation on behavior and neuronal excitability. The G297 residue is located in the intracellular linker of transmembrane segments S2 and S3, and is thus not involved in direct binding of Mg(2+) ions. Moreover, mutation of the only positively charged residue in the other intracellular linker between S4 and S5 also results in a dramatic reduction of Mg(2+)-dependent modulation of Eag activation kinetics. Collectively, the two mutations in eag eliminate or even paradoxically reverse the effect of Mg(2+) on channel activation and inactivation kinetics. Together, these results suggest an important role of the intracellular linker regions in gating processes of Eag channels.