Function of the CaMKII-ryanodine receptor signaling pathway in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia

BACKGROUND:Calcium calmodulin-dependent kinase II(CaMKII) can be more active in patients with left ventricular hypertrophy(LVH),which in turn causes phosphorylation of ryanodine receptors,resulting in inactivation and the instability of intracellular calcium homeostasis.The present study aimed to determine the effect of CaMKII-ryanodine receptor pathway signaling in rabbits with left ventricular hypertrophy and triggered ventricular arrhythmia.METHODS:Forty New Zealand rabbits were randomized into four groups(10 per group):sham group,LVH group,KN-93 group(LVH+KN-93),and ryanodine group(LVH+ryanodine).Rabbits in the LVH,KN-93,and ryanodine groups were used to establish a left ventricular hypertrophy model by the coarctation of the abdominal aorta,while those in the sham group did not undergo the coarctation.After eight weeks,action potentials(APs) were recorded simultaneously in the endocardium and epicardium,and a transmural electrocardiogram(ECG) was also recorded in the rabbit left ventricular wedge model.Drugs were administered to the animals in the KN-93 and ryanodine groups,and the frequency of triggered APs and ventricular tachycardia was recorded after the rabbits were given isoprenaline(1 μmol/L) and high-frequency stimulation.RESULTS:The frequency(animals/group) of triggered APs was 0/10 in the sham group,10/10 in the LVH group,4/10 in the KN-93 group,and 1/10 in the ryanodine group.The frequencies of ventricular tachycardia were 0/10,9/10,3/10,and 1/10,respectively.The frequencies of polymorphic ventricular tachycardia or ventricular fibrillation were 0/10,7/10,2/10,and 1/10,respectively.The frequencies of triggered ventricular arrhythmias in the KN-93 and ryanodine groups were much lower than those in the LVH group(P<0.05).CONCLUSIONS:KN-93 and ryanodine can effectively reduce the occurrence of triggered ventricular arrhythmia in rabbits with LVH.The CaMKII-ryanodine signaling pathway can be used as a new means of treating ventricular arrhythmia.

Effects of nerve growth factor on the action potential duration and repolarizing currents in a rabbit model of myocardial infarction

Objectives To investigate the effect of nerve growth factor (NGF) on the action potential and potassium currents of non-infarcted myocardium in the myocardial infarcted rabbit model.Methods Rabbitswith occlusion of the left anterior descending coronary arterywere prepared and allowed to recover for eight weeks (healed myocardial infarction, HMI). During ligation surgery of the left coronary artery, a polyethylene tube was placed near the left stellate ganglion in the subcutis of the neck for the purpose of administering NGF 400 U/d for eight weeks (HMI + NGF group). Cardiomyocytes were isolated from regions of the non-infarcted left ventricular wall and the action potentials and ion currents in these cellswere recorded using whole-cell patch clamps. Results Comparedwith HMI and control cardiomyocytes, significant prolongation of APD50 or APD90 (Action potential duration (APD) measured at 50% and 90% of repolarization) in HMI + NGF cardiomyocytes was found. The results showed that the 4-aminopyridine sensitive transient outward potassium current (Ito), the rapidly activated omponent of delayed rectifier potassium current (IKr), the slowly activated component of delayed rectifier potassium current (IKs), and the L-type calcium current (ICaL) were significantly altered in NGF + HMI cardiomyocytes compared with HMI and control cells. Conclusions Our results suggest thatNGF treatment significantly prolongsAPDinHMI cardiomyocytes and that a decrease in outward potassium currents and an increase of inward Ca2+ current are likely the underlying mechanism of action.

Real-time detection of LMP1/LMP1 interaction in MβCD-induced apoptosis of nasopharyngeal carcinoma cells using FRET method

Latent mermbrane protein 1(LMP1)is known as an oncoprotein in nasopharyngeal carcinoma(NPC)cells,which is considered to have a strong association with growth,invasion and metastasis of NPC cells through lipid rafts.Met hy-A-cyclodextrin(M3CD)can disrupt lipid rafts through cholesterol depletion.In this study,we revealed that MICD induced apoptosis in two kinds of NPC cells including CNE1 cells,a LMP1 negative nasopharyngeal squamous carcinoma cell line,and CNE1-LMP1 cells,a LMP1-positive nasopharyngeal squamous carcinoma cell line.Furthermore,the impact of MBCD on LMP1 was investigated by fuorescence resonance energy transfer(FRET)method in NPC cells.Synchronized tempo spatial and spectral detection of LMP1/LMP1 interaction were performed using fluorescence microscope and spectrograph.FRET efficiency indicated that LMP1/LMP1 interaction gradully enhanced after M9CD treatment.MTT assays showed that M8CD caused strong cytotoxicity in CNE1 cells,but cauused relatively weaker cytotoxicity in CNE1-LMP1 cells,which indicated that LMP1 may regulate sensitivity of NPC cells to MBCD.Then,detection of cleaved caspase-3 in two kinds of NPC cells indicated that LMP1 may inhibit activation of caspase 3.These results strongly suggested that MBCD can induce apoptosis of NPC cells,but enhancing of LMP1/LMP1 interaction may likely resist apoptosis through inhibiting cleavage of caspase-3.

Comparison of Talaromyces marneffei Infection in Human Immunodeficiency Virus-positive and Human Immunodeficiency Virus-negative Patients from Fujian, China

Background： Talaromyces （Penicillium） marneffei （TIM） is an emerging dimorphic human pathogenic fungus that is endemic to Southeast Asia. TM mostly occurs as an opportunistic infection in patients with human immunodeficiency virus （HIV）. The objective of this study was to compare the clinical and laboratory parameters of patients with TM infections who were HIV-positive and HIV-negative and to assess therapies and outcomes. Methods： This was a retrospective analysis of 26 patients diagnosed with disseminated TM infection from September 2005 to April 2014 at Fujian Provincial Hospital, China. Results： Patients with TM infection tend to present with fever, weight loss, and anemia. The time from symptom onset to confirmed diagnosis was greater for HlV-negative patients （n 7; median： 60 days, range： 14-365 days） than for HIV-positive patients （n = 19; median： 30 days, range： 3-90 days, Mann-Whitney U= 31.50, P = 0.041）. HIV-negative patients were more likely to have dyspnea （57.1% vs. 5.3%, Z： = 8.86, P = 0.010）, low neutrophil count （Mann-Whitney U = 27.00, P = 0.029）, high CD4 count （Mann-Whitney U= 0.00, P 0.009）, and high lymphocyte count （Mann-Whitney U = 21.00, P = 0.009）. There were no significant differences in other demographic, clinical, or biochemical characteristics. Among all the patients, 12 HIV-positive patient and 1 HlV-negative patient received amphotericin and fluconazole treatment, 9 of whom improved, l died, 2 had kidney damage, 1 had hypokalemia due to exceeded doses. Conclusions： HIV-negative patients with TM infections tend to have a longer diagnostic interval, a higher percentage of dyspnea, higher levels of CD4 and lymphocytes, and lower neutrophil counts than TM infection in HIV-positive patients. Treatment programs with amphotericin and fluconazole are mostly effective.

Adenocarcinoma arising from intrahepatic heterotopic pancreas: A case report and literature review

Heterotopic pancreas is mostly found incidentally, and adenocarcinoma arising from heterotopic pancreas appears to be extremely rare. A case of a 46-year-old woman with adenocarcinoma arising from intrahepatic heterotopic pancreas is reported herein. Computed tomography demonstrated a mass located in the bile duct of the left hepatic lobe. Pathological examination revealed a moderately differentiated adenocarcinoma arising from intrahepatic heterotopic pancreas with nerve infiltration. This may be the first reported case of adenocarcinoma arising from intrahepatic heterotopic pancreas.

Efficacy of Dual Antiplatelet Therapy Combined with Naoxintong Capsules(脑心通胶囊) Following Coronary Microembolization Induced by Homologous Microthrombi in Rats

Objective： To evaluate the efficacy of dual antiplatelet therapy combined with Naoxintong Capsule （脑心通胶囊, NXTC） in a rat model of coronary microembolization （CME）. Methods： A total of 95 rats were randomly divided into 6 groups： control, sham-operation, CME model, NXTC, dual antiplatelet （clopidogrel and aspirin） intervention （DA）, and NXTC combined with DA （NDA） groups. The complete data in 69 rats were obtained. The number of CME, myocardial apoptosis rate, bleeding time, clotting time, and adensosine diphosphate （ADP）-induced platelet aggregation were assessed. Results： Compared with the CME group, the number of CME and myocardial apoptosis rates were significantly decreased in the NXTC, DA, and NDA groups （P〈0.01）. Compared with other intervention groups, the number of CME and myocardial apoptosis rates were the least in the NDA group （P〈0.01）, and the incidence of surgical bleeding was the highest in the DA group （P〈0.01）. Compared with the CME group, ADP-induced maximum platelet aggregation rate was significantly inhibited in the NXTC, DA, and NDA groups （P〈0.01）, both bleeding time and clotting time were significantly increased in the NXTC, DA, and NDA groups （P〈0.01）, while the above parameters were the highest in the DA group （P〈0.05）. Conclusion： The combination therapy of NXTC and DA enhanced the anti-CME effect of either therapy alone and reduced the risk of the DA therapy-associated bleeding, demonstrating an improved benefit/ risk ratio in the rat model of CME.

Comparison of Aspirin and Naoxintong Capsule(脑心通胶囊)with Adjusted-Dose Warfarin in Elderly Patients with High-Risk of Non-Valvular Atrial Fibrillation and Genetic Variants of Vitamin K Epoxide Reductase

Objective： To compared the therapeutic effect of a Chinese patent medicine Naoxintong Capsule（脑心通胶囊, NXT） and aspirin with adjusted-dose warfarin in Chinese elderly patients（over 65 years） with nonvalvular atrial fibrillation（NVAF） and genetic variants of vitamin K epoxide reductase（VKORC1）, who are at high-risk of thromboembolism. Methods： A total of 151 patients, with NVAF and AA genotype of VKORC1-1639（a sensitive genotype to warfarin） and a CHA2 DS2-VASc clinical risk score of 2 or above, were chosen for this study. Patients were randomized into two groups and orally treated with a combination of aspirin（100 mg/day） and NXT（1.6 g thrice a day） or adjusted-dose warfarin [international normalized ratio 2.0–3.0）. The primary end points including ischemic stroke and death as well as the secondary end points including hemorrhage events were followed up for at least 1 year. Results： Baseline clinical data and the rates of primary end points were similar between groups. However, the rate of serious bleeding（secondary event） in the combination therapy group was lower than that in the adjusted-dose warfarin group（0% vs. 7.9%, odds ratio： 0.921, 95% confidence interval： 0.862–0.984, P=0.028）. Conclusions： Aspirin combined with NXT and warfarin displayed comparable rates of primary end point including ischemic stroke and all-cause death during the 1-year follow-up. However, as compared with warfarin, the combination therapy reduced the rate of serious bleeding. Therefore, aspirin combined with NXT might provide an alternative pharmacotherapy in preventing ischemic stroke for elderly patients with NAVF who cannot tolerate warfarin.（No. ChiC TR-TRC-13003596）

Cytotoxic Activities of Total Saponins from Plena Clematis on Human Tumor Cell Lines In Vitro

Objective： To investigate the anti-proliferative effects of saponins prepared from Plena Clematis （PC） cultured in Fujian Province, China on 4 human tumor cell lines and its possible anti-tumor mechanism. Methods： The growth inhibition assays of saponins on human esophageal squamous carcinoma cell line （EC9706）, human hepatoma cell line （HepG-2）, human oral cancer cell line （KB） and human gastric cancer cell line （BGC-823） were evaluated in vitro by thiazolyl blue （MTT） method. The inhibitory effects on EC9706 treated with different concentrations of saponins （15.62, 31.25, 62.50, 125, 250 and 500 μg/mL） were performed in vitro by MTT method. The morphology and nuclear staining with acridine orange/ethidium bromide of EC9706 calls treated with saponins were illustrated under an inverted phase fluorescence microscope. The apoptotic effects of saponins were further evaluated by annexin-V/propidium iodide dual staining experiment to examine the occurrence of phosphatidylserine externalization onto the call surface by a flow cytometer. Results： MTT assay showed that the saponins could inhibit the proliferation of 4 tumor cell lines. Among them, the maximum inhibition rate of 73.1% was detected in EC9706 cells at the saponins concentration of 250 μg/mL for 24 h. Further investigation indicated that the saponins induced EC9706 cells apoposis. The EC9706 cells presented apoptotic characteristics when treated with saponins, including that the morphologies of EC9706 cells were appeared round-shaped with higher refraction, and the cell nuclear stained orange with EB after 250 μ g/mL saponins exposure. The flow cytometry analysis results showed that the induction of cell cycle arrest in apoptotic system may participate in the anti-proliferative activity of saponins on EC9706 cells. Conclusion： The saponins from PC exhibited significant cytotoxicity against human EC9706, KB, BGC-823, and HepG-2 cells and might be beneficial to development of ethnic pharmaceutical plant for potential anti-tumor drugs.

Measurement of crater geometries after laser ablation of bone tissue with optical coherence tomography

The feasibility of measuring crater geometries by use of optical coherence tomography （OCT） is examined. Bovine shank bone on a motorized translation stage with a motion velocity of 3 mm/s is ablated with a pulsed CO2 laser in vitro. The laser pulse repetition rate is 60 Hz and the spot size on the tissue surface is 0.5 mm. Crater geometries are evaluated immediately by both OCT and histology methods after laser irradiation. The results reveal that OCT is capable of measuring crater geometries rapidly and noninvasively as compared to histology. There are good correlation and agreement between crater depth estimates obtained by two techniques, whereas there exists distinct difference between crater width estimates when the carbonization at the sides of craters is not removed.

Analysis of the efficacy of a modified posteromedial approach for Klammer III posterior Pilon fractures

Purpose:To analyze the curative effect and technical points of a modified posteromedial approach in the treatment of Klammer III posterior Pilon fracture.Methods:A retrospective analysis of patients with Klammer III posterior Pilon fractures were conducted in our department from January 2018 to December 2019.Before the surgery,the patients were fully relieved of swelling and pain,and a comprehensive examination was carried out.The posteromedial approach exposed the posterior and medial fracture block of the distal tibia.According to the fracture of external malleolus,it is determined whether to combine a lateral incision and protect tendons and vascular nerves by a retractor,and then perform a fracture reduction and internal fixation.Postoperatively,the patients were treated with analgesia,detumescence,anticoagulation and rehabilitation exercise.The American orthopaedic foot and ankle society(AOFAS)score and visual analogue score were recorded at regular follow-up after surgery.A t-test was used for the comparison of the preoperative and final AOFAS score.Results:There were 7 male and 13 female(n=20)included in the study,aged 22 to 88 years(average age 54.2 years).The injury mechanisms were falling from a height(n=7),traffic accident(n=6),walking injury(n=2)and heavy injury(n=5).The postoperative follow-up duration was 12—24 months(mean 16.95 months).The AOFAS score of the 20 patients before and after surgery were compared.The preoperative AOFAS score was 38.90±3.91,and the final AOFAS score was 80.55±4.20,(p<0.001).The mean final visual analogue scores at rest,active and weight-bearing walking were 0.30,0.85 and 1.70,respectively.One patient reported poor postoperative wound healing and required a return to hospital for debridement and anti-infection treatment.Conclusion:In the treatment of Klammer III posterior Pilon fractures,the modified posteromedial approach can fully expose the fracture block and the collapsed articular surface of the medial malleolus,achieve good reduction and internal fixation with limited injury of the tendon and vascular nerves,and have a better prognosis.

Influence of scanning velocity on bovine shank bone ablation with pulsed CO_2 laser

The influence of scanning speed on hard bone tissue ablation is studied with a 10.6-μm laser. The groove morphology and the thermal damage created in bovine shank bone by pulsed CO2 laser are examined as a function of incident fluence by optical microscope following standard histological processing. The results show that ablation groove width, depth and ablation volume, as well as the zone of thermal injury, increase gradually with incident fluence. As compared to the result for high scanning speed, the lower scanning speed always produces larger ablation volume but thicker zone of thermal injury. It is evident that scanning speed plays an important role in the ablation process. In clinical applications, it is important to select appropriate scanning speed to obtain both high ablation rates and minimal thermal injury.

A Randomized Controlled Trial of Adjunctive Bunchang Naoxintong Capsule (步长脑心通胶囊) Versus Maintenance Dose Clopidogrel in Patients with CYP2C19*2 Polymorphism

Objective：To determine the impact of adjunctive Buchang Naoxintong Capsule（步心脑心通胶囊,NXT） on dual antiplatelet therapy in patients with cytochrome P450 2C19＊2（CYP2C19＊2） polymorphism undergoing percutaneous coronary intervention（PCI）.Methods：Ninety patients with CYP2C19＊2 polymorphism were enrolled,and their genotypes were confirmed by polymerase chain reaction（PCR）.The patients were randomly assigned to receive either adjunctive NXT（triple group,45 cases） or dual antiplatelet therapy（dual group,45 cases） using a computer-generated randomization sequence and sealed envelopes.Platelet function was assessed at baseline and 7 days after treatment with conventional aggregometry.Subsequent major adverse cardiovascular events（MACE,including sudden cardiac arrest and acute coronary syndrome） were recorded during a 12-month followup.Results：Baseline platelet function measurements were similar in both groups.After 7 days,percent inhibitions of maximum platelet aggregation and late platelet aggregation were significantly greater in the triple versus dual group（42.3%±16.0%vs.20.8%±15.2%,P〈0.01,and 54.7%±18.3%vs.21.5%±29.2%,P〈0.01,respectively）.During the 12-month follow-up,the rate of subsequent MACE（6/45） was significantly lower in the triple group compared with the dual group（14/45;P〈0.05）.Conclusion：Adjunctive NXT to maintenance dose clopidogrel（75 g） could enhance the antiplatelet effect and decrease subsequent MACE in patients with the CYP2C19＇2polymorphism undergoing PCI.

Fenestration operation in middle ear bone with pulsed infrared lasers: an in-vivo study

The feasibility of fenestration operation in middle ear bone with pulsed infrared laser is evaluated. Healthy male New Zealand rabbits in vivo are used in the experiment. Middle ear mastoid bone of animal model is completely exposed with conventional methods, and then a pulsed CO2 laser （10.6 μm） and an Er：YAG laser （2.94 μm） are used to perform the fenestration operation. Diamond drill is also used as a control group. The total operation time and light irradiation time are recorded and the opening efficiency is assessed. The morphological changes and thermal damage around the opening window on the middle ear bone are examined. It is shown that both laser systems are suitable for the fenestration operation in middle ear bone, and this no-touch technique has a lot of benefits compared with traditional methods. The bleeding during operation has an important effect on operation time and thermal injury and needs to be controlled efficiently in further study.