The effect of dexmedetomidine on expression of neuronal nitric oxide synthase in spinal dorsal cord in a rat model with chronic neuropathic pain / O efeito da dexmedetomidina na expressão do óxido nítrico sintase neuronal na medula espinhal dorsal em um modelo rato com dor neuropática crônica

Abstract Background Neuropathic pain typically refers to the pain caused by somatosensory system injury or diseases, which is usually characterized by ambulatory pain, allodynia, and hyperalgesia. Nitric oxide produced by neuronal nitric oxide synthase (nNOS) in the spinal dorsal cord might serve a predominant role in regulating the algesia of neuropathic pain. The high efficacy and safety, as well as the plausible ability in providing comfort, entitle dexmedetomidine (DEX) to an effective anesthetic adjuvant. The aim of this study was to investigate the effect of DEX on the expression of nNOS in spinal dorsal cord in a rat model with chronic neuropathic pain. Methods Male Sprague Dawley (SD) rats were randomly assigned into three groups: sham operation group (sham), (of the sciatic nerve) operation (CCI) group, and dexmedetomidine (DEX) group. Chronic neuropathic pain models in the CCI and DEX groups were established by sciatic nerve ligation. The thermal withdrawal latency (TWL) was measured on day 1 before operation and on day 1, 3, 7 and 14 after operation. Six animals were sacrificed after TWL measurement on day 7, and 14 days after operation, in each group, the L4-6 segment of the spinal cords was extracted for determination of nNOS expression by immunohistochemistry. Results Compared with the sham group, the TWL threshold was significantly decreased and the expression of nNOS was up-regulated after operation in the CCI and DEX groups. Compared with the CCI grou[, the TWL threshold was significantly increased and the expression of nNOS was significantly down-regulated on day 7 and 14 days after operation in the DEX group. Conclusion Down-regulated nNOS in the spinal dorsal cord is involved in the attenuation of neuropathic pain by DEX.

Resumo Antecedentes A dor neuropática refere-se tipicamente à dor causada por lesões ou doenças do sistema somatossensorial. De modo geral, é caracterizada por dor à ambulação, alodinia e hiperalgesia. O óxido nítrico produzido pela enzima óxido nítrico sintase neuronal (nNOS) na medula espinhal dorsal pode ter um papel predominante na regulação da dor neuropática. A alta eficácia e segurança, bem como a plausível capacidade de proporcionar conforto, faz com que a dexmedetomidina (DEX) seja um adjuvante anestésico eficaz. O objetivo deste estudo foi investigar o efeito da DEX na expressão de nNOS na medula espinhal dorsal em um modelo de ratos com dor neuropática crônica. Métodos Ratos Sprague Dawley (SD) machos foram distribuídos aleatoriamente em três grupos: grupo de cirurgia simulada (sham), grupo de cirurgia (do nervo ciático; CCI) e grupo dexmedetomidina (DEX). Os modelos de dor neuropática crônica nos grupos CCI e DEX foram estabelecidos por ligadura do nervo ciático. A latência de retirada térmica (TWL) foi medida no dia 1 antes da cirurgia e nos dias 1, 3, 7 e 14 após o procedimento. Seis animais de cada grupo foram eutanasiados após a medida de TWL nos dias 7 e 14 após a cirurgia e o segmento L4-6 da medula espinhal foi extraído para determinação da expressão de nNOS por imuno-histoquímica. Resultados Em comparação ao grupo sham, o limiar de TWL diminuiu significativamente e a expressão de nNOS foi regulada de maneira positiva após a cirurgia nos grupos CCI e DEX. Comparado ao grupo CCI, o limiar de TWL aumentou de forma significativa e a expressão de nNOS caiu significativamente diminuída nos dia 7 e 14 após a cirurgia no grupo DEX. Conclusão A regulação negativa de nNOS na medula espinhal dorsal está envolvida na atenuação da dor neuropática pela DEX.

Effect of VEGF on Neural Differentiation of Human Embryonic Stem Cells in vitro / 华中科技大学学报（医学）（英德文版）

The effects of vascular endothelial growth factor (VEGF) on neural differentiation of human embryonic stem cells (hESCs) in vitro and the possible mechanism were observed. The hESCs lines,TJMU1 and TJMU2, were established and stored by our laboratory, hESCs differentiated into neuronal cells through embryonic body formation. In this induction process, hESCs were divided into three groups: group A, routine induction; group B, routine induction+10 ng/mL VEGF; group C, routine in-duction+10 ng/mL VEGF+10 ng/mL VEGFR2/Fc. OCT4, Nestin and GFAP in each group were de-tected by RT-PCR, and the cells expressing Nestin and GFAP were counted by immunofluorescence.The percentage of Nestin positive cells in group B was significantly higher than in groups A and C,while the percentage of GFAP positive cells in group B was significantly lower than in groups A and C (P<0.01). There was no significant difference between groups A and C (P>0.05). It was concluded that VEGF, via VEGFR2, stimulated the neural differentiation of hESCs in vitro.

Intracranial Hypertension Syndrome in Systemic Lupus Erythema-tosus:Clinical Analysis and Review of the Literature / 华中科技大学学报（医学）（英德文版）

In order to better understand the clinical manifestation of systemic lupus erythematosus (SLE) with intracranial hypertension syndrome (IHS),we analyzed the clinical features and treatment of a typical SLE patient with IHS.SLE is one of the most unpredictable autoimmune diseases in-volving multiple organ systems that is defined clinically and associated with antibodies directed against cell nuclei.IHS is an uncommon manifestation of neuropsychiatric SLE (NPSLE) and is characterized by an elevated intracranial pressure,papilledema,and headache with occasional ab-ducens nerve paresis,absence of a space-occupying lesion or ventricular enlargement,and normal cerebrospinal fluid chemical and hematological constituents.IHS has been reported in a few sporadic cases in patients with SLE worldwide,but rarely has been reported in China.In this study,a 34-year-old female SLE patient with IHS was.reported and pertinent literature reviewed.The clinical presentation,image logical features,and investigatory findings were discussed.

Packaging and Functional Identification of Recombinant A deno-associated Virus Encoding cdc2-siRNA / 华中科技大学学报（医学）（英德文版）

Cyclin dependent kinases (cdks) play an important role in the pathogenesis of multiple neurodegenerative diseases. To explore the possibility of cdks-related gene therapy for neurodegenerative diseases, we packed recombinant adeno-associated virus (rAAV) encoding cdc2-siRNA. The expressing plasmid pAAV-MCS-EGFP-U6-odc2-siRNA was constructed by using molecular biological techniques. The rAAV encoding cdc2-siRNA (rAAV-EGFP-U6-cdc2-siRNA) was packed by calcium phosphate mediated co-transfection of the plasmid pAAV-MCS-EGFP-U6-cdc2-siRNA, p-RC and p-Helper into AAV-293 cells. DNA sequencing proved the successful construction of U6-cdc2-siRNA in pAAV-MCS-EGFP. Seventy-two h after packaging, the expression of EGFP could be detected in AAV-293 cells. Western blotting revealed that cdc2 gene expression in AAV-293 cells was down-regulated markedly after transfection with rAAV-EGFP-U6-cdc2-siRNA, which evidenced the satisfactory silencing effect of this virus. It was concluded that the packaging of rAAV encoding cdc2-siRNA was successful, rAAV encoding cdc2-siRNA could silence cdc2 gene effectively, which might offer a novel means for the treatment of neurodegenerative diseases.

Protective Effects of Overexpression of bcl-xl Gene on Local Cerebral Infarction in Transgenic Mice Undergoing Permanent Occlusion of Middle Cerebral Artery / 华中科技大学学报（医学）（英德文版）

In order to investigate the protective effects of the overexpression of bcl-xl gene on local cerebral infarction in the transgenic mice subject to permanent occlusion of middle cerebral artery, the models of bcl-xl transgenic mice were established and subjected to cerebral infarction by intralu- minal occlusion of the middle cerebral artery. The infarct volume and the neurological scores were observed and comparison between the wild type mice and the transgenic mice was made. It was found that the infarct volume and the neurological scores in the transgenic mice were significantly decreased as compared with those in the wild type mice. It was suggested that the overexpression of bcl-xl gene in transgenic mice could reduce the infarct volume and improve the neurological function of the mice.

Astrocytes Facilitate the Growth and Differentiation of Co-cultured Mesenchymal Stem Cells / 华中科技大学学报（医学）（英德文版）

The effect of astrocytes on the growth and differentiation of co-cultured mesenchymal stem cells (MSCs) was studied. MSCs of Wistar rats were isolated, cultured and labeled with Hoechst33342. The labeled MSCs were co-cultured with astrocytes in DMEM/F12/10%FBS. The growth status and morphologic change of MSCs were observed. The expression of specific protein NeuN, GFAP and CNP was detected by using immunofluorescence staining. The results showed that the two kinds of co-cultured cells grew well. Some labeled MSCs stretched out long processes with spin, triangle and star shapes. Immunofluorescence stain showed that these cells expressed NeuN, GFAP or CNP. It was suggested that astrocytes could promote the prolifevation of co-cultured MSCs and induce them to differentiate into neural like cells.