Effect of iron overload on electrophysiology of slow reaction autorhythmic cells of left ventricular outflow tract in guinea pigs

Objective:To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of guinea pigs.Methods:Standard microelectrode cell recording techniques were adopted to observe the electrophysiological effects of different concentrations of FeResults:FeConclusions:Fe

Effect of iron overload on electrophysiology of slow reaction autorhythmic cells of left ventricular outflow tract in Guinea pigs

Objective: To investigate the electrophysiology effects and mechanism of iron overload on the slow response autorhythmic cells in the left ventricular outflow tract of Guinea pigs. Methods: Standard microelectrode cell recording techniques were adopted to observe the electrophysiological effects of different concentrations of Fe

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

OBJECTIVE@#To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure.@*METHODS@#Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet, pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency.@*RESULTS@#Compared with the control group, 4 phase automatic depolarization velocity, spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly (P < 0.01) and action potential amplitude reduced (P < 0.01) in model group. Moreover, repolarization 50% and 90% increased (P < 0.01).@*CONCLUSIONS@#There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

Electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure

Objective To investigate the electrophysiological changes of autonomic cells in left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with chronic heart failure. Methods Guinea pigs model of iron deficiency anemia complicated with chronic heart failure in 10 guinea pigs of the experimental group was made by feeding a low iron diet, pure water and subcutaneous injection of isoproterenol. The control group consisting of 11 guinea pigs was given normal food, normal water and injected with normal saline. The left ventricular outflow tract model specimen was also prepared. The standard microelectrode technique was used to observe electrophysiological changes of autonomic cells in the outflow tract of left ventricular heart failure complicated with iron deficiency anemia in guinea pig model. The indicators of observation were maximal diastolic potential, action potential amplitude, 0 phase maximal depolarization velocity, 4 phase automatic depolarization velocity, repolarization 50% and 90%, and spontaneous discharge frequency. Results Compared with the control group, 4 phase automatic depolarization velocity, spontaneous discharge frequency and 0 phase maximal depolarization velocity decreased significantly (P < 0.01) and action potential amplitude reduced (P < 0.01) in model group. Moreover, repolarization 50% and 90% increased (P < 0.01). Conclusions There are electrophysiological abnormalities of the left ventricular outflow tract in guinea pigs with iron deficiency anemia complicated with heart failure.

An investigation on the infection status and genotype of Hantavirus carried by rodents in Yuyao City of Zhejiang Province / 预防医学

Objective To learn the infection status and genotype of Hantavirus carried by rodents in Yuyao City.Methods From May,2014 to May,2015,a total of 248 rodents were captured from four kinds of characteristic topographies (plains, mountains,coastal and urban areas)with clip night method in Yuyao.The real time fluorescence quantitative PCR method was used to detect the Hantavirus from lung specimens of rodents.The RT-PCR method was used to sequence and analyze the M fragment gene.Results Hantavirus nucleic acid was detected positive in 12 samples from a total of 248 specimens, and the positive rate was 4.84%,and they were all detected in Rattus norvegicus and were all Seoul virus (SEOV).Eight samples were sequenced and analyzed,and phylogenetic tree was constructed.The result showed SEOV S3 subtype with high homology.Conclusion Hantavirus carried by rodents in Yuyao City is mainly SEOV S3 subtype,and the distribution of gene subtype is single.Rattus norvegicus is the main host of this virus.

Effects of dihydromyricetin on tumor necrosis factor and NF-kappaB p65 of RAU rats / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of dihydromyricetin (DMY) on tumor necrosis factor (TNF-alpha) and NF-kappaB p65 cells of the recurrent aphthous ulcer (RAU) rat.</p><p><b>METHOD</b>Sixty of Sprague Dawley (SD) rats are randomly divided into 6 groups. The rat RAU models was established by injection of immunogen composed of the homogenate supernate of homogeneous oral mucosa from SD rats and Freund's complete adjuvant (FCA) into rat backs subcutaneously once every two weeks for 5 times, and the only FCA injected as normal control. DMY(50,100, 200 mg x kg(-1)) and licorzine (67.5 mg x kg(-1)) were given intragastrically once daily for 7 days on the day of the last immunogen injection, respectively. Water was given instead of drugs in normal and model control groups. The blood was got from the fundus oculi vein of rats on the day after last administration, the serum was separated. Then the rats were put to death with the cervical dislocation and decollated on the ice stage. Two sides of rat buccal mucosal tissue were cut. One side of them was put into 4% neutral formalin and another was added into 10 times of phosphate buffer to homogenize it homogenate. The oral mucosa ulcer occurrence of rats was observed by the histopathology. The content of TNF-alpha in serum and oral mucosa was assayed with ELISA; the expression of NF-kappaB cells was determined by the immunohistochemisty and macrophagus was determined by azure-feosin-dyeing in oral mucosa tissue. The expression of TNF-alpha mRNA in serum and oral mucosa was detected by reverse transcription polymerase chain reaction.</p><p><b>RESULT</b>In RAU rats, oral mucosa ulcer occurred, the content of TNF-alpha raised and the expression of TNF-alpha mRNA increased in serum and oral mucosa, the expression of positive NF-kappaB p65 cells and the amount of macrophages went up in oral mucosa. DMY and licorzine significantly reduced occurrence of oral mucosa ulcer in RAU rats, lowered content of TNF-alpha and the expression of TNF-alpha mRNA in serum and oral mucosa, reduced expression of positive NF-kappaB p65 cells and the amount of macrophages.</p><p><b>CONCLUSION</b>It is considered that DMY could inhibited occurrence of oral mucosa ulcer in RAU rats. One principle of it's effects could be that DMY controlled NF-kappaB p65 regulation on transcription and release of TNF-alpha mRNA in macrophages in oral mucosa ulcer tissue and lead to fall of TNF-alpha content in oral mucosa tissue causing role of anti-oral mucosa ulcer.</p>

Icariin associated with exercise therapy is an effective treatment for postmenopausal osteoporosis / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>There are no conclusive studies evaluating the interaction between icariin and exercise for treatment of osteoporosis; the efficacy and safety of this treatment combination remains to be evaluated. The purpose of this study was to investigate the effects of icariin treatment combined with exercise therapy on bone parameters and body weight of ovariectomized rats.</p><p><b>METHODS</b>Ovariectomized rats were used as a model of postmenopausal osteoporosis and were exposed to either icariin treatment, exercise, hormone replacement therapy, or a combination of the above. Untreated, ovariectomized rats and sham operated rats were used as controls. After 3 months of experimental interventions the effects of the treatments on the body and uterine weights, the physical and biomechanical properties of bones, and the expression of the osteoblast-specific gene Osterix (Osx), were assessed.</p><p><b>RESULTS</b>The weight gain of the ovariectomized rats was greater than that of the treated experimental groups. Uterine weight and serum estradiol levels were significantly greater in sham operated and estrogen-treated ovariectomized rats than in the other groups. Biomechanical parameters were improved significantly in ovariectomized rats treated with exercise alone or treated with exercise and icariin. Osx expression was increased in ovariectomized rats treated with exercise and icariin or treated with just icariin.</p><p><b>CONCLUSIONS</b>Exercise combined with icariin had a synergistic effect in the early prevention of osteoporosis in ovariectomized rats. The effects of icariin and exercise on osteoporosis are worth further exploration.</p>

Oblique-sagittal black-blood contrast-enhanced magnetic resonance imaging in preoperative evaluation for carotid endarterectomy / 南方医科大学学报

<p><b>OBJECTIVE</b>To evaluate the value of oblique-sagittal black-blood contrast-enhanced magnetic resonance imaging (OB-CEMRI) in atherosclerotic carotid artery (CA) assessment before carotid endarterectomy (CEA).</p><p><b>METHODS</b>Twenty-five patients with symptomatic atherosclerotic stenosis in the carotid artery (involving 26 arteries) were scheduled for CEA. OB-CEMRI and digital subtraction angiography (DSA) were conducted within 1 week prior to CEA, and two radiologists independently assessed the location of maximal lumen stenosis, plaque rupture, degree of maximal lumen stenosis and plaque involvement on DSA and OB-CEMRI images. The differences of DSA and the OB-CEMRI in analyzing the plaque conditions were assessed in comparison with matched histological sections of the excised specimens.</p><p><b>RESULTS</b>Compared with the corresponding histological specimens, both DSA (κ=0.807) and OB-CEMRI (κ=0.812) showed a good consistency in defining the location of the maximal lumen stenosis. OB-CEMRI showed a better performance in detecting plaque rupture with higher sensitivity (90.0%) and specificity (83.3%) than DSA (40.0% and 66.7%, respectively). No significant difference was found between DSA and the OB-CEMRI in evaluating the degree of maximal lumen stenosis [(77.33∓3.79)% vs (76.02∓3.95)%, P=0.648]. Compared with the histological examination, OB-CEMRI appeared to underestimate the stenosis. The plaque extent on OB-CEMRI was larger than that on DSA (18.96∓4.96 mm vs 14.80∓3.78 mm, P=0.004), and similar to that by histological examination (18.13∓4.57 mm, P=0.506).</p><p><b>CONCLUSIONS</b>OB-CEMRI allows noninvasive and objective detection of the location of the maximal lumen stenosis, plaque rupture, and plaque extent, though with a lower accuracy than DSA in the assessment of the maximal lumen stenosis. OB-CEMRI combined with DSA offers a more reliable means for preoperative evaluation of the carotid artery plaques for CEA.</p>

Electrophysiological effects of antiarrhythmic drugs on pacemaker cells in guinea pig left ventricular outflow tract / 中国应用生理学杂志

<p><b>OBJECTIVE</b>To explore the electrophysiological effects of antiarrhythmic drugs on pacemaker cells of left ventricular outflow tract.</p><p><b>METHODS</b>By using conventional intracellular microelectrode technique to record action potentials, series antiarrhythmic drugs were used to investigate the electrophysiological features and regularities of spontaneous activity of left ventricular outflow tract.</p><p><b>RESULTS</b>(1) Perfusion with 1 micromol/L quinidine resulted in a significant decrease in rate of pacemaker firing (RPF, P < 0.05), velocity of diastolic depolarization (VDD, P < 0.05), amplitude of action potential (APA, P < 0.05), and maximal rate of depolarization (V(max), P < 0.05), and a marked prolonging in 50% and 90% of duration of action potential (APD50 and APD90, P < 0.05). (2) 1 micromol/L lidocaine decreased RPF, VDD, MDP, APA and V(max) significantly (P < 0.05), shortened APD50 and APD90 notably (P < 0.05). (3) 1 micromol/L propafenone led to a significant decrease in RPF (P < 0.01), VDD (P < 0.05), APA (P < 0.05), V(max) (P < 0.01), and a marked prolonging in APD50 (P < 0.01) and APD90 (P < 0.05). (4) Application of 5 micromol/L propranolol resulted in a significant decrease in RPF and VDD (P < 0.01), MDP and APA (P < 0.01), V(max) (P < 0.05) and a notable prolonging in APD50 and APD90 (P < 0.05). (5) Perfusion with 1 micromol/L amiodarone resulted in a significant decrease in RPF and VDD (P < 0.01), APA (P < 0.01), V(max) (P < 0.05), a marked prolonging in APD50 (P < 0.01) and APD90 (P < 0.05). (6) 1 micromol/L verapamil significantly decreased RPF and VDD (P < 0.01), MDP and APA (P < 0.05), V(max) (P < 0.05), notably prolonged APD50 and APD90 (P < 0.01). (7) 50 micromol/L adenosine significantly decreased RPF and VDD (P < 0.05), APA (P < 0.05), V(max) (P < 0.01), markedly shortened APD50 and APD90 (P < 0.05).</p><p><b>CONCLUSION</b>All kinds of antiarrhythmic drugs can decrease the autorhythmicity of guinea pig left ventricular outflow tract. By altering APD50 and APD90, they can affect effective refractory period (ERP) and having a significant effect on autorhythmicity of left ventricular outflow tract.</p>

Diagnosis and surgical treatment of tight carotid stenosis / 中华外科杂志

<p><b>OBJECTIVE</b>To explore the specialty of diagnosis and surgery of tight carotid stenosis.</p><p><b>METHOD</b>From January 2000 to December 2009, 53 patients with tight carotid stenosis (> 95%) were operated on. All 53 patients had tight carotid stenosis more than 95% on one side in whom 28 had contralateral carotid stenosis or occlusion. The clinical and imaging data as well as surgical outcomes of the patients were retrospectively analyzed.</p><p><b>RESULTS</b>Forty-five patients had postoperatively done well without any complications. There were 3 cases of hemodynamic instability and one case of cardiac ischemia which resolved in one to two days. One patient developed mild hoarseness. One complicated with bacteremia due to deep vein catheter insertion. Two patients experienced brain hemorrhage. None of this series occurred perioperative brain ischemia.</p><p><b>CONCLUSIONS</b>Tight carotid stenosis indicates a need for expeditious carotid endarterectomy with very low rates of brain ischemia. Intraoperative shunting is seldom necessary. Postoperative hyperperfusion syndrome and brain hemorrhage should be worried. Micro-endarterectomy can effectively prevent from restenosis.</p>

Inhibition of the expression of cardiomyocytic hypoxic induction factor-1alpha during hypoxic state by double chain siRNA / 中华烧伤杂志

<p><b>OBJECTIVE</b>To construct hypoxic induction factor-1alpha (HIF-1alpha) siRNA expression cassette containing U6 promoter, alpha HIF-1alpha sense or antisense target sequence, and to observe its influence on the expression of cardiomyocytic HIF-1alpha during hypoxic state.</p><p><b>METHODS</b>Neonatal murine cardiomyocytes cultured in the mixed gas were employed as the hypoxic model and were divided into normal control (cultured in normal oxygen), RNAi control (invalidated transfection interference sequence IV) and RNAi effective inhibition (effective transfection interference sequence, which was further divided into I, II and III groups according to the difference of downstream primer) groups. Three pairs (I, II and III) of PCR downstream primer containing HIF-1alpha encoded gene fragments (sense and antisense) and one pair of randomize sequence (IV) PCR downstream primer were designed and synthesized. U6 starter expression frame was constructed by PCR method. The cardiomyocytes were transfected simultaneously by sense and antisense sequence expression frame. Five plates of the cells were set at each time points in each group. The expression of HIF-1alpha mRNA was detected by RT-PCR at 6 hours of hypoxia. The change in the protein expression level at 1 hour of hypoxia was determined by Western blot, and the interference effects were monitored by immunohistochemistry.</p><p><b>RESULTS</b>The best inhibition fragment screened was group II sequence. After the transfection and hypoxic culture, it was found that the cardiomyocytic HIF1alpha mRNA and protein levels in RNAi effective inhibition group were evidently lower than those in normal control and RNAi control groups (P < 0.01). While the protein inhibition rate (60% - 80%) between the former group and normal and RNAi control groups was no difference (P > 0.05).</p><p><b>CONCLUSION</b>The expression of the HIF1alpha in hypoxic rat cardiomyocytes could be effectively inhibited by our constructed HIF1alpha siRNA expression cassette group II.</p>

Studies on the changes in expression of hypoxia induction factor-1alpha in myocardial tissue in severely scalded rats during early postburn stage / 中华烧伤杂志

<p><b>OBJECTIVE</b>To investigate the changes in the expression of hypoxia induction factor-1alpha (HIF1-alpha) in myocardial tissues in severely scalded rats during early postburn stage.</p><p><b>METHODS</b>Male Wistar rats inflicted with 40% TBSA III degree scald were employed as the model. The myocardial tissue samples were harvested from the left and right ventricles at different postburn time points, and samples were also obtained from normal rats as control. The mRNA and protein expressions of HIF-1alpha in rat myocardial tissue were determined by RT-PCR and Western blot analysis respectively.</p><p><b>RESULTS</b>There was a difference of HIF-1alpha expression between left and right ventricles of the normal rats at both transcriptional and translational levels, and the mRNA and protein expressions of HIF-1alpha in the myocardial tissue of scalded rats were increased dramatically at early postburn stage.</p><p><b>CONCLUSION</b>The tolerance to ischemia and hypoxia of the rat left ventricle was higher than that of the right ventricle under normal condition. An increase in HIF1alpha expression in rat myocardial tissue could be induced in severely scalded rats.</p>