The modulation and mechanisms of high-altitude hypoxia in drug transport across the blood-brain barrier / 药学学报

The function of the central nervous system was significantly altered under high-altitude hypoxia, and these changes lead to central nervous system disease and affected the metabolism of drugs in vivo. The blood-brain barrier is essential for maintaining central nervous system stability and plays a key role in the regulation of drug metabolism, and barrier structure and dysfunction affect drug transport to the brain. Changes in the structure and function of the blood-brain barrier and the transport of drugs across the blood-brain barrier under high-altitude hypoxia are regulated by changes in brain microvascular endothelial cells, astrocytes and pericytes, and are regulated by drug metabolism factors such as drug transporters and drug metabolizing enzymes. This article reviews the effects of high-altitude hypoxia on the structure and function of the blood-brain barrier and the effects of changes in the blood-brain barrier on drug metabolism. We investigate the regulatory effects and underlying mechanisms of the blood-brain barrier and related pathways such as transcription factors, inflammatory factors and nuclear receptors on drug transport under high-altitude hypoxia.

G6PD Regulates Cyclin E1 and CDK2 to Promote Cell Proliferation and Its Prognostic Value in Clear Cell Renal Cell Carcinoma / 中国生物化学与分子生物学报

Clear cell renal cell carcinoma (ccRCC) has been proved to be a metabolic disease with high

Effect of hypoxia on drug metabolizing enzymes and transporters and the role of microRNA / 药学学报

The function of circulatory system, nervous system and endocrine system is significantly changed in hypoxic environments. These changes affect the absorption, distribution, metabolism, and excretion of drugs in the body. Drug metabolizing enzymes and transporters are the main factors affecting drug metabolism; microRNA (miRNA) can act directly on drug metabolizing enzymes and transporters and can regulate their genes through hypoxia-inducible factor, inflammatory cytokines, and nuclear receptors. This article reviews the effect of hypoxia on drug metabolizing enzymes and transporters and the mechanisms by which miRNA modulates these proteins and their expression during hypoxia.

Changes in the intestinal flora of rats under high altitude hypoxia / 药学学报

The structure and diversity of the intestinal flora in rats exposed to high altitude hypoxia was investigated. Animal experiments strictly follow the regulations of Medical Laboratory Animal Ethics Committee of Qinghai University, School of Medicine. SD rats were randomly divided into a control group, a moderate altitude hypoxia group, and a high altitude hypoxia group. The pH value of the feces was measured and histopathological changes in the small intestine were determined by HE staining, and the intestinal flora were characterized by 16S rDNA high throughput sequencing technology on the 3rd, 7th, 15th, and 30th day of hypoxia exposure. Compared with the control group, the fecal pH value of rats in the moderate altitude hypoxia group and the high altitude hypoxia group was decreased significantly. The lamina propria and submucosa capillaries were slightly dilated and congested on the 3rd day in the moderate altitude hypoxia group. In the high altitude hypoxia group the submembrane capillaries were dilated and congested, the lamina propria of the mucosa showed mild edema, and the lymphatic vessels were dilated on the 7th day. The composition and diversity of intestinal flora in these rats changed significantly with prolonged exposure to the high altitude hypoxic environment. A total of 35 phyla, 87 classes, 205 orders, 337 families, 638 genera, and 256 species were annotated in the three groups of rats, including Firmicutes, Clostridia, Clostridiales, Ruminococcaceae, Akkermansia, and Lactobacillus_murinus. Compared with the control group, the intestinal flora of the hypoxic groups showed the most significant changes by the 15th day. There were 9 microbiota of gut microorganisms with relative abundance in the moderate altitude hypoxia group, of which Rikenellaceae_RC9_gut_group bacteria was the most common, there were 19 different microbiota of gut microorganisms with higher relative abundance in the high altitude hypoxia group, of which Ruminococcaceae bacteria was the most common. The results of this study indicate significant changes in the intestinal flora with high altitude hypoxia, and establish a foundation for further research on the initiation and development of diseases and drug metabolism in high altitude hypoxia.

Analysis of risk factors for cerebral apoplexy in the recipients after renal transplantation / 器官移植

Objective To analyze the risk factors for cerebral apoplexy in the recipients after renal transplantation. Methods Clinical data of 376 renal transplant recipients who were followed up regularly were retrospectively analyzed. The recipients were divided into cerebral apoplexy group (39 cases) and non-cerebral apoplexy group (337 cases) according to the occurrence of cerebral apoplexy. The risk factors of cerebral apoplexy were analyzed using single factor analysis and COX proportional hazards regression model. Results The 376 recipients were followed up for a median duration of 55 months, among whom 39 recipients suffered from cerebral apoplexy, with a cumulative incidence of 10.4%. Single factor analysis indicated that there were significant differences in age ≥40 years old at transplantation, duration of dialysis ≥12 months before transplantation, estimated glomerular filtration rate (eGFR) <30 mL/(min·1.73m2), incidence of hypertension, diabetes and dyslipidemia between cerebral apoplexy group and non-cerebral apoplexy group (all P<0.05).Multivariate analysis indicated that the independent risk factors for cerebral apoplexy occurred in the recipients after renal transplantation were age ≥40 years old [hazard ratio (HR) =1.110, 95% confidence interval (CI)=1.067-1.154,P=0.000],duration of dialysis≥12 months before transplantation(HR=1.044,95%CI=1.021-1.067,P=0.000)and eGFR<30 mL/(min·1.73m2)(HR=2.448,95%CI=1.197-5.005,P=0.014).Conclusions The independent risk factors for cerebral apoplexy in the recipients after renal transplantation include age≥40 years old, long duration of dialysis before transplantation and renal insufficiency.

Advantages of ultrasound-guided caudal epidural block over TIVA for transrectal ultrasound guided transrectal prostate biopsy / 中国医师杂志

Objective To compare the safety and efficacy of the caudal block and Total Intravenous Anesthesia (TIVA) for transrectal ultrasound (TRUS) guided prostate biopsy.Methods 60 elderly patients with transrectal ultrasound guided transperineal prostate biopsy were randomized into Group A and Group B.Patients in Group A received ultrasound guided caudal block (0.33％ ropivacaine 15 ml) and patients in Group B received TIVA.In operation room (T1),immediately before operation (T2) and at the end of operation (T3),mean artery pressure (MAP),heart rate (HR),breathing rate (BR) and pulse oxygen saturation (SpO2) were recorded.The patients in two groups were rated the level of mini-mental state examination (MMES) at 2 h,8 h and 24 h after operation.Complications during the whole study period were also evaluated.Results The values of MAP,HR and BR of T1 in group B were significantly lower than those at T2 (P＜0.05),and were lower than those in the group A (P ＜0.05).The MMSE value in group A [2 h (25.66 ± 1.71) and 8 h (26.13 ± 1.52)] was significantly higher than that in group B [2 h (27.96 ± 1.71) and 8 h (29.01 ± 0.77)] at after operation (P ＜ 0.05).The rate of usage of ephedrine (13％) and assisted ventilation (20％) in group B was higher.No significant differences were detected in side effects between the two groups.Conclusions Caudal block provides better anesthesia than TIVA for TRUS guided prostate biopsy without an increase of side effects,and it may be safely used during ambulatory surgery.

Changes of schistosomiasis endemic situation in Sichuan Province and im-pact on schistosomiasis transmission in Three Gorges Reservoir area after construction of Three Gorges Reservoir / 中国血吸虫病防治杂志

Objective To understand the changes of schistosomiasis endemic situation in Sichuan Province,the upstream of Yangtze River basin,and the impact on schistosomiasis transmission in Three Gorges Reservoir area after the construction of Three Gorges Reservoir. Methods The annual reports of the schistosomiasis endemic situation in Sichuan Province from 2000-2012,the data of the schistosomiasis surveillance sites in Sichuan Province from 2001-2012,the data of the schistosomiasis sampling survey in Sichuan Province in 2001,and the relevant reference of Three Gorges Reservoir were collected. The schisto-somiasis prevalence in human and cattle,and Oncomelania hupensis snail status were investigated. The snail survey was imple-mented in Qianjin Village,Jianyang City,Sichuan Province,the nearest village to Three Gorges Reservoir Area. Results The schistosomiasis endemic situation presented a continuous declining state in Sichuan Province from 2000-2012,and reached the criteria of schistosomiasis transmission controlled in 2008. From 2012,65.07%of endemic counties reached the criteria of schis-tosomiasis transmission interrupted. From 2006,no schistosome infected snails were found. In Qianjin Village,1714 m2 environ-ments were surveyed and no snails were found. Conclusions The schistosomiasis endemic area and snail area are significantly reduced in Sichuan Province,the upstream of Yangtze River basin,after the construction of Three Gorges Reservoir. Therefore, the possibility of schistosomiasis endemic diffusing to Three Gorges Reservoir area is minimum.

Changing laws of serum high mobility group box 1 protein in septic rats and the intervention effect of xuebijing / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the changing laws of serum high mobility group box 1 protein (HMGB1) in septic rats and intervention effect of Xuebijing on it.</p><p><b>METHODS</b>Lipopolysaccharide (LPS) (5 mg/kg BW) was intravenously injected into the tail vein of healthy male Wistar rats to prepare the sepsis rat model. In Experiment 1: 50 Wistar rats were randomly divided into three groups, i.e., the normal group (A, n=10); the LPS model group (B, n=10), the LPS +Xuebijing treatment group (C, n=30). Rats in the C group were further divided into three subgroups, i.e., 2 h before LPS injection (group C1), 2 h after LPS injection (group C2), and 8 h after LPS injection (group C3), 10 in each group. Blood samples were collected from the caudal vein to detect serum HMGB1 levels by Western blot at 4, 12, 24, 48, and 72 h after LPS injection. Experiment 2: 30 Wistar rats were equally divided into the LPS model group (D) and the LPS + Xuebijing treatment group (E), 15 in each group. They were treated as rats in the B group and the C1 group respectively. Five rats were sacrificed at 12, 24, and 48 h after LPS injection in the two groups. Blood as well as the tissue samples were harvested to measure such indices as ALT, AST, Cr, and BUN, as well as pathological changes of liver, lung, and kidney.</p><p><b>RESULTS</b>(1) Compared with the A group, serum HMGB1 levels were higher at various time points in the B group (P < 0.05). Compared with the B group, serum HMGB1 levels at 12,24,48, and 72 h decreased in the C1, C2, and C3 groups. Besides, the decrease was more obvious at 24 h and 48 h.The decrement in the C3 group was less than that in the C1 and C2 groups (P < 0.05). (2) In the D group, ALT, AST, Cr, and BUN were significantly higher than those in the A group and reached the peak at 24 h (P < 0.05). Compared with the E group, AST, Cr, and BUN at 24 and 48 h, and ALT at each time point decreased significantly in the E group (P < 0.05). (3)The results of pathological section of liver, lung, and kidney showed local congestion and hemorrhage, cell edema/necrosis/degeneration, infiltration of inflammatory cells, damage of characteristic structures and so on; particularly serious lesion occurred at 24 and 48 h in the D group. The microscopic lesion was obviously alleviated in the E group than in the D group at corresponding time points.</p><p><b>CONCLUSIONS</b>The serum HMGB1 levels increased in septic rats, with late occurrence of peak value and longer duration of the high value. HMGB1 played an important role in excessive inflammatory response and multiple organ dysfunction. Xuebijing could reduce the serum levels of HMGB1, improve biochemical parameters, and attenuate severe inflammatory response of liver, lung, and kidney tissues in septic rats. Besides, the earlier use, the better effect obtained.</p>

Design and study of network-based curriculm of hepatobiliary surgery / 中华医学教育探索杂志

This paper introduces the ideas and methods concerning the design of network-based curriculm of hepatobiliary surgery. Design of network-based curriculm should highlight independence of online learning,emphasize network-based resources to support learning.Net-work-based curriculm should emphasize the evaluation of learning effect.

Myocardial damage and change of mitochondrial Mn-superoxide dismutase activity in craniocerebral injured rats and the intervening effect of ginkgo biloba extract / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To investigate the myocardial damage and changes of myocardial mitochondrial Mn-superoxide dismutase (Mn-SOD) activity in craniocerebral injured rats and the effect of Ginkgo biloba extract (GBE) on them.</p><p><b>METHODS</b>Craniocerebral injured rats model was established by fluid-percussion and treated with GBE. The dynamical changes of electrocardiograph (ECG) in 24 h were monitored, the serum level of MB isoenzyme of creatine kinase (CK-MB) and the change of myocardial mitochondrial Mn-SOD activity as well as the pathologic changes of myocardium (HE staining) were observed.</p><p><b>RESULTS</b>The occurrence of ECG abnormality obviously increased in the injured rats, accompanied with increased serum CK-MB (P<0.05) and decreased myocardial Mn-SOD levels (P<0.05), and the Mn-SOD activity was negatively correlated with the level of CK-MB (r=-0.997, P<0.05). Pretreatment of GBE resulted in the decrease of ECG abnormality occurrence (P<0.01), serum CK-MB level (P<0.05), and degree of myocardial damage, as well as the increase of Mn-SOD activity in post-craniocerebral injured rats.</p><p><b>CONCLUSIONS</b>Craniocerebral injury can result in distinct myocardial damage, which is possibly correlated with the lowering of anti-oxidation stress level of myocardial cellular mitochondria. GBE possesses the protective effect on myocardial damage after craniocerebral injury.</p>

Effect of hemorrhage on cell apoptosis in hippocampal CA1 region of rats under controlled hypotension / 中南大学学报(医学版)

Objective To explore the effect of hemorrhage on cell apoptosis in the hippocampal CA1 region of rats under controlled hypotension (CH).Methods A total of 36 Sprague Dawley rats were randomly divided into 2 groups: Group C (with no CH) and Group H (with CH).According to different ratios of blood loss to total blood volume, Group C and Group H were redivided into 6 subgroups (6 in each group):C_1,H_1(10%);C_2,H_2(20%);C_3,H_3 (30%). Induced by so-dium nitroprusside and esmolol, the mean aterial pressure in Group H was decreased to 50～55 mmHg and kept for 10 minutes, and then blood loss was started, keeping the pump speed. Without CH, the same style of hemorrhage was performed in Group C. The aterial pressure was increased 60 minutes later after the hemorrhage.Expression of bcl-2 and caspase-3 protein was detected by immunohistochemical method, and apoptosis cells were detected by TUNEL staining. Results The average optical density of bcl-2 and caspase-3 was higher in Group H_3 than that in Group C_3(P＜0.05). There were more apoptosis cells examined by TUNEL in Group H_3 than in Group C_3(P＜0.05).Conclusion Thirty percent blood loss under controlled hypotension can induce cell apoptosis in hippocampal CA1 region in rats.

Effect of qingyi decoction in treating severe acute pancreatitis and its impacts on blood level of tumor necrosis factor-alpha, interleukin-6 and inteleukin-8 / 中国中西医结合杂志

<p><b>OBJECTIVE</b>To observe the effect of Qingyi Decoction (QYD) in treating severe acute pancreatitis (SAP) and its impacts on blood levels of tumor necrosis factor-alpha (TNF-alpha), interleukin 6 and 8 (IL-6 and IL-8).</p><p><b>METHODS</b>One hundred and ten patients of SAP were equally randomized into the treated group and the control group, they were treated with the same therapeutic program excepting that QYD was given only to the treated group. The post-treatment incidence of severe complication, mortality and operation transferring rate, as well as the changes of APACHE II scores and blood levels of TNF-alpha, IL-6 and IL-8 in patients of both groups were observed.</p><p><b>RESULTS</b>The incidences of the two severe complications, acute respiratory distress syndrome and intestinal paralysis, in the treated group was 3.6% and 5.4% respectively, while in the control group, 12.7% and 18.2%, showing statistical significance between groups (P < 0.05). The APACHE II score in the treated group decreased significantly on the 7th day, which was better than that in the control group (8.14 +/- 2.30 scores vs 3.35 +/- 2.20 scores, P < 0. 05). In addition, the efficacy in the treated group was also superior to that in the control group in terms of reducing mortality, operation transferring rate, and blood levels of TNF-alpha, IL-6 and IL-8 on the 7th and 9th day (P < 0. 05).</p><p><b>CONCLUSION</b>QYD could markedly improve the prognosis of SAP patients by way of lowering the blood levels of TNF-alpha, IL-6 and IL-8.</p>

Inhibition effect of small interfering RNA of connective tissue growth factor on the expression of vascular endothelial growth factor and connective tissue growth factor in cultured human peritoneal mesothelial cells / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>The peritoneum response to peritoneal dialysis can lead to fibrosis. The transforming growth factor beta1 (TGF-beta1) plays a key role in regulating tissue repair and remodelling after injury. Connective tissue growth factor (CTGF), a downstream mediator of TGF-beta1 inducing fibrosis, has been implicated in peritoneal fibrosis. Vascular endothelial growth factor (VEGF) plays a key role in angiogenesis that can hasten peritoneal fibrosis. In this study, we investigated the effect of small interfering RNA (siRNA) of CTGF by pRETRO-SUPER (PRS) retrovirus vector on the expression of CTGF and VEGF in human peritoneal mesothelial cells.</p><p><b>METHODS</b>Retrovirus producing CTGF siRNA were constructed from the inverted oligonucleotides and transferred into packaging cell line PT67 with lipofectamine, and the virus supernatant was used to infect human peritoneal mesothelial cell (HPMC). The cells were divided into seven groups: low glucose DMEM, low glucose DMEM + TGF-beta1 5 ng/ml, low glucose DMEM + TGF-beta1 5 ng/ml + PRS-CTGF-siRNA(1-4) and low glucose DMEM + TGF-beta1 5 ng/ml + PRS. The expression of CTGF and VEGF were measured by semiquantitative RT-PCR and Western blot.</p><p><b>RESULTS</b>Low levels of CTGF and VEGF were detected in confluent HPMCs. Following stimulation with TGF-beta1, the levels of CTGF and VEGF were significantly upregulated (P < 0.01). Introduction of PRS-CTGF-siRNA(1-4) resulted in the significant reduction of CTGF mRNA and protein, and VEGF mRNA (P < 0.01), especially in groups PRS-CTGF-siRNA1 and PRS-CTGF-siRNA4. The introduction of PRS void vector did not have these effects (P > 0.05).</p><p><b>CONCLUSIONS</b>The expression of CTGF siRNA mediated by PRS retrovirus vector can effectively reduce the level of CTGF and VEGF induced by TGF-beta1 in cultured HPMCs. This study may provide potential therapeutic strategies to prevent the peritoneal fibrosis.</p>

Protective effect of amlodipine on the cytotoxicity induced by contrast media in human kidney cells / 中南大学学报(医学版)

OBJECTIVE@#To explore the protective effect of amlodipine on the cytotoxicity induced by contrast media (meglumine diatrizoate) in human kidney cells (HKC).@*METHODS@#An HKC line was used. The experiment was divided into 4 groups: a model group (diatrizoate 111g/L), a prevention group (diatrizoate 111g/L+amlodipine 10(-5)mol/L), an amlodipine control group (amlodipine 10(-5)mol/L), and a culture medium control group (simple none blood serum DMEM-F12 medium). Cytotoxicity induced by meglumine diatrizoate was analysed by methyl thiazolyl tetrazolium (MTT) test, lactate dehydrogenase (LDH) assay, Hochest33258 fluorescence stained cytospins, and flow cytometric DNA analysis. The protein expression of Bax was determined by Western blot, and caspase-3 activity was examined by fluorometric method.@*RESULTS@#In the prevention group, the cell viability increased significantly (P<0.05), LDH levels decreased (P<0.05), and the apoptosis was lower than that of the model group (P<0.05) .Bax protein expression and caspase 3 activity decreased (P<0.05).@*CONCLUSION@#Amlodipine can inhibit the HKC apoptosis and protect the renal tubule cell from injury induced by meglumine diatrizoate.

Nephrotoxicity of high- and low-osmolar contrast media: Protective role of fosinopril or telmisartan in a rat model / 中南大学学报(医学版)

OBJECTIVE@#To compare the nephrotoxicity of high- and low-osmolar contrast media (HOCM and LOCM), and to determine the protective role of fosinopril or telmisartan and its possible mechanism.@*METHODS@#Forty eight healthy SD rats were randomly divided into 6 groups: a normal control group, a glycerol control group, a low-osmolar contrast media (LOCM) group, a high-osmolar contrast media (HOCM) group, a fosinopril group, and a telmisartan group. Glycerine for inducing kidney damage was given to all rats except the normal control group. Twenty-four hours after the injection of glycerine, the mixed fosinopril suspension (10mg/kg) or telmisartan (5mg/kg) was poured into the stomach in the preventive group. Serum creatinine (SCr) and plasma angiotensin II (AngII) levels were detected by an automatical biochemical analyzer and radioimmunoassay; caspase-3 activity and claudin-1 expression of the renal tissue were detected by fluorometric method and immunohistochemical method. The renal injury was assessed by hematoxylin and eosin (HE) staining and terminal deoxynucleotide mediated nick and labeling (TUNEL) staining, respectively.@*RESULTS@#In diatrizoate-injected rats, SCr and AngII levels were increased (P<0.05). Expression of claudin-1 protein and caspase-3 activity in the renal tissue was upregulated. The histologic changes and percentage of apoptotic cells were milder in the LOCM rats than those in the HOCM rats. In the group pretreated with fosinopril or telmisartan, no increase in the levels of SCr and AngII was discovered. The expression of claudin-1 protein and caspase-3 activity was significantly lower than that in the HOCM group. The renal injuries induced by diatrizoate were alleviated.@*CONCLUSION@#Both HOCM and LOCM could cause cellular apoptosis in the kidney.LOCM was less toxic to rat kidney than HOCM. Nephrotoxicity induced by HOCM might be related to caspase-3, claudin-1 and AngII. Fosinopril or telmisartan may protect the renal tissue from nephrotoxicity induced by diatrizoate.

Electrospinning and morphology of ultrafine poly (D, L-lactide) fibers / 生物医学工程学杂志

Ultrafine poly (D, L-lactide) (PLA) fibers with diameter less than 200 nm produced by electrospinning were studied to obtain tissue restoration resembling extracellular matrix. Scanning electron microscopy was used to observe the fiber morphology. Results showed that the solvent was the critical factor to determine the formation of the electrospun PLA fibers. Compared with acetone, N,N-dimethylformamide (DMF) was a better solvent for PLA to electrospin. Entrance of an organic salt, triethylbenzylammonium chlorate, led to a great increase of the conductivity of PLA/DMF solutions, so that the average fiber diameter of the electrospun PLA fibers decreased dramatically from 500 nm to 100-200 nm. The addition of surfactant, Span-80, did not improve the fiber morphology but formed beaded fiber web.

Effects of transforming growth factor-beta 1 on the peripheral nerve regeneration of rats / 中南大学学报(医学版)

OBJECTIVE@#To explore the effects of exogenous transforming growth factor-beta 1 (TGFbeta1) on peripheral nerve regeneration after the peripheral nerve injury and if TGFbeta1 regulates the expression of basic fibroblast growth factor (bFGF) in the anterior horn motoneurons of spinal cord during regeneration.@*METHODS@#Forty-eight rats were crushed on the right sciatic nerve and then randomly divided into 2 groups: TGFbeta1 group and NS group. In TGFbeta1 group, TGFbeta1 50 microL (0.1 microg/mL) was injected into the proximal nerve near to the crushed nerve and after the operation the injured leg was injected with equal TGFbeta1 whereas the NS was replaced in the NS group. The rats of each group survived for 3, 7, 14 and 21 days after the lesion. The bFGF expression in the anterior horn motoneurons of spinal cord was detected by immunohistochemistry (IHC). Semi-thin section and Fast Blue retrograde tracing were also performed with the rats surviving for 21 days to observe the regeneration of distal end in the injured right sciatic nerve.@*RESULTS@#The number of bFGF immunoreactive positive motoneurons in TGFbeta1 group was obviously higher than that of the NS group (P < 0.05). In the distal sciatic nerve of the rats treated with TGFbeta1, the number and diameter of regenerating myelinated axons and the thickness of myelinated sheath were more than those of the NS group (P < 0.05). The number of motoneurons in spinal cord and neurons in dorsol root ganglia (DRG) labelled with Fast Blue in the NS group was obviously lower than in the TGFbeta1 group (P < 0.01).@*CONCLUSION@#Exogenous TGFbeta1 plays an important role in promoting the peripheral nerve regeneration; TGFbeta1 up-regulates the bFGF expression in the anterior horn motoneurons of spinal cord during the peripheral nerve regeneration.

The expression of c-fos and transmitter calcitonin gene-related peptide in the chronic compressive injury of the nerve root / 中华外科杂志

<p><b>OBJECTIVES</b>To investigate the significance of c-fos oncogene morphogenetic protein's locational expression, and the correlativity between nerve transmitters calcitonin gene-related peptide (CGRP) expression and nerve root's functional change using the animal model of the chronic compressive injury in the nerve root.</p><p><b>METHODS</b>The animal model of chronic compressive injury of the nerve root was established by transplanting autogenous cancellous bone into the intervertebral foramen. During different injury phase (1, 2, 4, 8, 12, 24 weeks after operation), the functional status of the nerve root was determined under the monitoring of evoked potential, and the expression changes of c-fos oncogene morphogenetic protein and nerve transmitter CGRP were detected using in situ hybridization technique and their expression intensity was determined using automatic image analytic instrument respectively.</p><p><b>RESULTS</b>One week after operation, the c-fos expression strengthened in both anterior and posterior root fiber obviously. Two to four weeks after operation, the expression of the posterior root fiber weakened than the anterior root fiber. After 12 weeks, the anterior root fiber expression turned down obviously, however the posterior root fiber expression backed up slightly compared with that of the 8 weeks. By the time of 24 weeks after operation, the expression enhancement in all roots disappeared. CGRP expression increased obviously at the site of compressive axon of both anterior and posterior root. The expression of the posterior root axon and ganglion cell was higher than that of the anterior root axon. CGRP expression was diminished in the second week than the first week, and that was especially obvious in the posterior root and ganglion cell. But 4 weeks after operation, the expression enhanced once more, and that was more obvious inside the anterior root axon. Eight weeks after operation, the expression intensity attained the high peak. Twelve weeks after operation, the expression started the slow-moving descent.</p><p><b>CONCLUSIONS</b>The expression of c-fos gene protein is beneficial to localize the damaged part of certain nerve. During chronic injury, the degeneration of posterior root sensory fiber is earlier than the anterior root motor fiber. The expression of CGRP strengthened when the nerve fiber degenerated by the harmful stimulation, and the expression intensity is positively related with pain. That suggests when the nervous tissue is hurt, the information of warning and regulation should be sent out to our body.</p>

Three types of induced bursting rhythm in rat injured nerves / 生理学报

Firing patterns of injured nerve fibers were recorded using the single-fiber firing recording technique. Under the same background firing pattern, three types of bursting were induced separately by EGTA, veratridine or high [Ca(2+)](o) in the same type of nerve fibers. The results suggest that different firing patterns are related to different stimuli, which means that each firing pattern carries corresponding neural information.

Triggered oscillations in type A dorsal root ganglion neurons induced by veratridine / 生理学报

Veratridine, a blocker of inactive gate of sodium channel, was used to perfuse L5 dorsal root ganglion (DRG) topically. Afferent activities of type A single fiber from these DRGs were recorded. It was found that after a 10-min bath of veratridine (1.8-3 micromol/L), some of the primary silent DRG neurons were triggered by touch or pressure on the receptive fields or by electrical stimulation of the sciatic nerve to produce high-frequency firing, which was termed triggered oscillation presenting a U-type of interspike intervals (ISI) or other types of oscillations. The longer the intervals between stimulating pulses, the more stimulating pulses were needed to trigger the oscillation. The oscillation, triggered by electric stimuli with different duration or patterns, had no significant difference in their patterns. The duration of the inhibitory period after a triggered oscillation was generally 30-90 s. It was also observed that this kind of triggered oscillation was induced by afferent pulses of the same neurons. These results suggest that triggered oscillation, which may contribute to the fit of triggered pain, can be produced in primary sensory neurons after application of veratridine.