[Patient-derived parotid gland pleomorphic adenoma organoid model and its preliminary histological and functional characterization].

Objective: To establish patient-derived organoid models of pleomorphic adenomas (PA) of the parotid gland and preliminarily characterize their histology, related biomarkers and functions. Methods: Fresh tumor tissue specimens were collected from surgical procedures of Oral and Maxillofacial Department. The harvested tissues were processed and cultured in a head and neck tumor organoid culture system to establish organoid models from parotid gland pleomorphic adenomas. The in vitro growth of PA organoids was recorded by light microscopy. The successfully established organoids were passaged and cryopreserved, and the cryopreserved PA organoids were revived and re-cultured to observe their viability and organoid regeneration ability. Histological characterization, as well as characterization and detection of related markers and functional proteins, were performed on the organoids, comparing them with the patient-derived tissues. Results: The constructed organoid model of pleomorphic adenoma exhibited a dense and compact three-dimensional spherical structure. Hematoxylin and eosin staining indicated morphological similarities between the organoid and its tissue of origin. Immunohistochemistry showed positive cytoplasmic staining for Calponin, cytokeratin 7, and epithelial membrane antigen in both the organoid and the source tumor tissue, suggesting consistent histopathological characteristics between the organoid and its tissue of origin. Periodic acid-Schiff staining of the organoid showed positive staining for glycogen, with positive staining located in the interior and periphery of the organoid, indicating that the organoid possessed secretory functions like the salivary gland. Conclusions: This study successfully constructed organoids of pleomorphic adenoma derived from patient samples. This model faithfully replicates the tissue morphology and biomarkers of the source tissue and exhibits biological functions associated with mucus secretion. It serves as a valuable in vitro model for studying the development and progression of salivary gland tumors.

[A randomized controlled study on the long-term efficacy of intra-cervical lymphatic immunotherapy for adult allergic rhinitis].

Objective: To determine the long-term efficacy and safety of intra-cervical lymphatic immunotherapy (ICLIT) for adult allergic rhinitis (AR) by comparing it with subcutaneous immunotherapy (SCIT). Methods: A total of 100 adult AR patients with dust mite allergy in Department of Otorhinolaryngology, First People's Hospital of Foshan from Feb 2018 to Dec 2019 were randomly divided into two groups, 50 in SCIT group [including 42 males and 8 females, aging (32.55±9.72) years] and 50 in ICLIT group [including 45 males and 5 females, aging (31.33±9.84) years]. The changes in total symptom score (total system score, TSS), nasal symptom score (total nasal symptom score, TNSS), eye symptom score (total ocular scoring system, TOSS), drug score (total medication score, TMS), and quality of life score of the two groups of patients were evaluated before and after treatment, and the adverse reactions of all patients during the treatment period were recorded. The changes in the level of dust mite specific IgE (sIgE) in the serum were evaluated. GraphPad Prism 9.0 software was used for statistical analysis. Results: In the SCIT group, 38 patients completed treatment and follow-up, with a dropout rate of 24%. In the ICLIT group, 48 patients completed treatment and follow-up, with a dropout rate of only 4%. The scores of TSS, TNSS, TOSS, TMS, and quality of life in the ICLIT group before treatment were 32.1±3.0, 27.3±3.1, 4.8±2.8, 2.3±0.9, and 68.1±28.7, respectively; After 36 months of treatment, the scores were 21.8±11.4, 18.1±9.4, 3.7±2.9, 1.3±1.1, and 36.0±26.7, respectively, which were significantly lower than those before treatment (all P<0.001). After 36 months of treatment, the TSS of the ICLIT group improved by 10.3±11.2 compared to before, while the TSS of the SCIT group improved significantly by 21.9±11.0 compared to before, with statistically significant differences between the groups (P<0.001). No serious systemic adverse reactions occurred in both groups of patients. Conclusions: ICLIT treatment for adult AR has long-term efficacy, high safety, and high compliance, but its long-term efficacy is not as good as SCIT. ICLIT can be considered as a new complementary option for AR immunotherapy.

The role of surface tension on the growth of bubbles by rectified diffusion.

Rectified diffusion has wide and important applications in sonochemistry, ultrasonic cleaning and medical ultrasound. Recent experimental results have demonstrated that the addition of surfactant substantially enhances bubble growth rate. As a hypothesis, this was widely attributed to the acoustic microstreaming and mass transfer resistance caused by surfactants. In this research, the effects of the surfactant of sodium dodecyl sulphate on the rectification have been simulated by considering only the variation of the surface tension coefficient due to the surfactant. The computations are carried out using a newly developed tractable model based on the multi-scale method and the method of matched asymptotic expansions, which allows the prediction of bubble growth taking place over millions of oscillation cycles. The rate of bubble growth observed in the experiments is accurately predicted by our computations, for a range for bulk surfactant SDS concentrations less than or equal to 2.4 mM. Contrary to the widely held hypothesis in the published literature, this has demonstrated that the dominant physical mechanisms remain the shell and area effects in this range of bulk surfactant concentrations. The further enhancement of bubble growth rate provided by either acoustic microstreaming or the resistance to mass transfer is only evident at higher bulk surfactant concentrations. Therefore, the role of surface tension in rectified diffusion for aqueous surfactant solutions is more significant than previously understood. The new results also show that the bubble growth rate is sensitive to small changes in the bubble radius which may account for its unpredictability in applications of sonochemistry.

Correlations between the femoral neck osteotomy angle and radiologic and clinical outcomes analyzed in patients undergoing total hip replacement with metaphyseal fixation.

OBJECTIVE: This study will explore whether the femoral neck osteotomy angle (FNOA) has an effect on hip anatomical functional reconstruction and clinical outcomes after total hip arthroplasty (THA). PATIENTS AND METHODS: The study included 254 patients (296 hips) who underwent primary total hip arthroplasty using the same uncemented short stem (Tri-Lock BPS) between December 2018 and December 2019. Correlations between FNOA and the radiologic and clinical outcomes of patients were analyzed. RESULTS: Patients were divided into 3 groups according to different FNOA. FNOA ≤50° is Group A, 50°< FNOA <55° Group B, and FNOA ≥55° Group C. There were significant differences among the three groups in distal D1 (p=0.029), sitting proud (SP) (p<0.001), varus and valgus alignment (p<0.001), FO (p=0.001), and caput-collum-diaphysis angle (CCD) (p<0.001). There were significant differences in the incidence of complications among the three groups (p<0.007). There was a significant linear correlation with D1 (B=0.005, CI=0.002 to 0.008, p=0.004), SP (B=-0.266, CI=-0.286 to 0.166, p<0.001), the femoral stem varus-valgus alignment angle (B=-0.359, CI=-0.422 to -0.297, p<0.001), femoral offset (FO) (B=-0.500, CI=-0.795 to -0.205, p=0.001), and CCD (B=0.696, CI=0.542 to 0.849, p<0.001). In logistic regression analysis, inappropriate FNOA increased the risk of dislocation (OR=0.892, CI=0.812 to 0.979, p=0.016) and thigh pain (OR=0.920, CI=0.851 to 0.995, p=0.037). CONCLUSIONS: The study demonstrates the relationship between FNOA and short-term radiological and clinical outcomes of patients after THA using a Tri-Lock femoral prosthesis. Inappropriate FNOA was significantly associated with failure of hip anatomical reconstruction and a higher risk of complications.

[Efficacy of stent placement in treatment of malignant tracheoesophageal fistula and relevant factors of fistula closure].

Objective: To investigate the efficacy of stent placement in the treatment of malignant tracheoesophageal fistula (MTEF) and the factors affecting the closure of the fistula. Methods: Clinical, pathological, laboratory, and imaging data of 288 patients with MTEF admitted to Zhongda Hospital, Southeast University from 2015 to 2021were retrospectively analyzed. Among them, there were 208 males; the age was (63.6±10.5) years. A total of 94 patients received conservative treatment (conservative group), and 194 in the stent group (170 cases with esophageal stents and 24 cases with tracheal stents). Patients were followed-up at 2 weeks, 1 month, 3 months, and 6 months to evaluate the effect of stent implantation. Multivariable logistic regression was used to analyze factors affecting fistula closure. Results: Age, fistula size, leukocyte count before treatment, and fistula location were significantly different between the conservative group and the stent group (P<0.05). The Karnofsky functional status (KPS) score before treatment in the conservative group was lower than the stent group, (45.1±1.0) vs (51.8±0.7) scores, respectively (P<0.001). After 2 weeks and 1 month of treatment, improvement in KPS scores was significantly better in the stent group than in the conservative group (P<0.05). At 1 month, the pulmonary infection rate in the stent group was 33.5% (58/173), significantly lower than that in the conservative group [77.0% (47/61); P<0.001]. Among the 288 patients, the fistula was closed in 196 patients and unclosed in 92 patients. Fistula size (OR=3.429, 95%CI: 1.623-7.829, P=0.001), leukocyte count before treatment (OR=1.160, 95%CI: 1.027-1.317, P=0.018), KPS score before treatment (OR=0.898, 95%CI: 0.848-0.945, P<0.001) and the treatment method (conservative treatment as reference, esophageal stent OR=0.010, 95%CI: 0.004-0.030, P<0.001; tracheal stent OR=0.003, 95%CI: 0.000-0.042, P<0.001) were factors affecting fistula closure. In the 170 patients in the esophageal stent group, early complications (≤24 h) occurred in 71 patients, and late (>24 h) complications occurred in 11 patients. While in the 24 patients in the tracheal stent group, 9 had early complications and 2 had late complications. Conclusions: Stent placement is an effective treatment for MTEF compared to conservative treatment. Stent treatment, small fistula size, low pre-treatment leukocyte count, and high pre-treatment KPS score are beneficial to fistula closure.

[Liver: a unique immune organ].

Immune system cannot only help the body resist the attack of pathogens, but it also prevents the reaction to its own components. In addition, there is a delicate balance between immune defense and immune tolerance. Therefore, once the balance is broken, diseases may appear. Notably, the liver is a unique and important immune organ, and its immune function under physiological and pathological conditions has important research value.

[Ten years of research progress in the field of non-viral liver disease].

The field of non-viral liver disease mainly includes autoimmune liver disease, non-alcoholic fatty liver disease, drug-induced liver injury, genetic metabolic liver disease, and so on. This article emphasis on the key points of clinical and basic research related to the combined field of autoimmune liver disease and non-alcoholic fatty liver disease in past ten years, and review its progress and existing difficulties.

Improved biofilm removal using cavitation from a dental ultrasonic scaler vibrating in carbonated water.

The use of cavitation for improving biofilm cleaning is of great interest. There is no system at present that removes the biofilm from medical implants effectively and specifically from dental implants. Cavitation generated by a vibrating dental ultrasonic scaler tip can clean biomaterials such as dental implants. However, the cleaning process must be significantly accelerated for clinical applications. In this study we investigated whether the cavitation could be increased, by operating the scaler in carbonated water with different CO2 concentrations. The cavitation around an ultrasonic scaler tip was recorded with high speed imaging. Image analysis was used to calculate the area of cavitation. Bacterial biofilm was grown on surfaces and its removal was imaged with a high speed camera using the ultrasonic scaler in still and carbonated water. Cavitation increases significantly with increasing carbonation. Cavitation also started earlier around the tips when they were in carbonated water compared to non-carbonated water. Significantly more biofilm was removed when the scaler was operated in carbonated water. Our results suggest that using carbonated water could significantly increase and accelerate cavitation around ultrasonic scalers in a clinical situation and thus improve biofilm removal from dental implants and other biomaterials.

Negative viral nucleic acid test of induced sputum: an additional criteria for COVID-19 patient's discharge.

OBJECTIVE: Concerns have been raised that patients with Coronavirus Disease 2019 (COVID-19) are still infectious with a re-positive nucleic acid test of the pharyngeal swab after hospital discharge. The aim of this study was to investigate the clinical relevance of induced sputum as an additional indicator for the current clinical discharge criteria of COVID-19 patients to prevent virus recurrence. PATIENTS AND METHODS: Twenty-one COVID-19 patients who met the national clinical discharge criteria were discharged from the hospital and tested daily for the presence of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) nucleic acid in their pharyngeal swabs and every other day for the presence of SARS-CoV-2 in their induced sputum. Once the patient's induced sputum was negative after two consecutive tests, testing was discontinued. RESULTS: Among 21 discharged patients from COVID-19, the first pharyngeal swab and induced sputum tests for viral nucleic acid were positive in 3 (14.3%) and 8 (38.1%) patients respectively. Induced sputum was significantly more positive than pharyngeal swab (p < 0.05). In our cohort, all pharyngeal swabs became negative at day 7, and all induced sputa turned negative at day 11 after discharge. Interestingly, patients with negative pharyngeal swabs experienced viral relapse, whereas patients with negative induced sputum did not revert to positivity. CONCLUSIONS: The detection rate of positive viral nucleic acid in induced sputum was high. Patients with negative induced sputum nucleic acid tests did not have a relapse of SARS-COV-2, indicating that viral nucleic acid testing of induced sputum should be used as an additional criterion for patients with national clinical discharge criteria COVID-19.

The effect of standoff distance and surface roughness on biofilm disruption using cavitation.

Effective biofilm removal from surfaces in the mouth is a clinical challenge. Cavitation bubbles generated around a dental ultrasonic scaler are being investigated as a method to remove biofilms effectively. It is not known how parameters such as surface roughness and instrument distance from biofilm affect the removal. We grew Strepotococcus sanguinis biofilms on coverslips and titanium discs with varying surface roughness (between 0.02-3.15 µm). Experimental studies were carried out for the biofilm removal using high speed imaging and image analysis to calculate the area of biofilm removed at varying ultrasonic scaler standoff distances from the biofilm. We found that surface roughness up to 2 µm does not adversely affect biofilm removal but a surface roughness of 3 µm caused less biofilm removal. The standoff distance also has different effects depending on the surface roughness but overall a distance of 1 mm is just as effective as a distance of 0.5 mm. The results show significant biofilm removal due to an ultrasonic scaler tip operating for only 2s versus 15-60s in previous studies. The technique developed for high speed imaging and image analysis of biofilm removal can be used to investigate physical biofilm disruption from biomaterial surfaces in other fields.

No infectious risk of COVID-19 patients with long-term fecal 2019-nCoV nucleic acid positive.

OBJECTIVE: It has recently been reported that some COVID-19 patients have long-term positive fecal nucleic acid after discharging from the hospital with negative nucleic acid in the respiratory tract, but it is unclear whether COVID-19 patients with positive long-term fecal nucleic acid tests have the risk of self-infection. PATIENTS AND METHODS: From January 25, 2020 to March 9, 2020, 5 COVID-19 patients with negative respiratory tract nucleic acid and positive fecal nucleic acid were observed and studied to explore whether these patients can re-infect themselves. Five patients with COVID-19 accompanied by diarrhea as the main gastrointestinal symptoms were carefully observed through clinical symptoms, imaging and other auxiliary examinations. The RT-PCR technology was used to continuously detect fecal and respiratory viral nucleic acids. The IgM antibody was detected on the 7th day of admission and IgM/IgG at the time of discharge. RESULTS: All 5 patients had symptoms of fever and diarrhea upon admission. The fecal nucleic acid was positive, as well as the throat swab was positive. All COVID-19 patients had positive IgM antibodies on the 7th day of admission and positive IgM and IgG at the time of discharge, and there were no abnormalities in the gastrointestinal examination on discharge. All 5 fecal nucleic acid tests were positive at the time of discharge. After continuous dynamic follow-up for 3-15 days, no clinical symptoms recurred, and the last nucleic acid test was negative. CONCLUSIONS: There is no risk of self-infection for COVID-19 patients with long-term 2019-nCoV nucleic acid positive in feces.

[Analysis of clinical diagnosis and treatment in chronic hepatitis B combined with autoimmune hepatitis].

Objective: To summarize the clinical diagnosis and therapeutic method in chronic hepatitis B (CHB) combined with autoimmune hepatitis (AIH). Methods: Clinical manifestations, laboratory examination, imaging, histopathological characteristics, treatment and prognosis of 19 cases diagnosed with CHB combined with AIH followed at the outpatient Department of Gastroenterology of Renji Hospital Affiliated to Shanghai Jiao Tong University School of Medicine during December 2013 to June 2018 were retrospectively analyzed. Paired sample t-test was used before and after treatment for the measurement of normal distribution data. Measurement data of non-normal distribution were expressed as a median (quartile spacing) and Wilcoxon matched-pairs signed rank test was used before and after treatment. Results: Among the 19 cases, 5 were male and 14 were female. The age of onset was 35 to 63 years, and the average age was 47.10 ± 8.76 years. There were 12 cases diagnosed with CHB before AIH, 5 cases diagnosed with AIH before CHB, and 2 cases diagnosed with AIH and CHB at the same time. After the definite diagnosis of CHB combined with AIH, nucleoside (acid) analogues (antiviral against hepatitis B virus) combined glucocorticoid therapy were given, and azathioprine or mycophenolate mofetil (immunosuppressant) was added according to the intrahepatic inflammation (inflammation graded at G3 and above) and leukocyte conditions. The duration of treatment varied between 2 weeks to 16 (median treatment duration of 6 weeks), except for one case who was just diagnosed and followed up. Biochemical indicators and immunoglobulin of the remaining 18 cases before and after treatment was significantly decreased, and the differences were statistically significant (P < 0.05), with HBV DNA < 20 copies/ml. Conclusion: CHB combined with AIH diagnosis can be easily missed. Therefore, it requires comprehensive diagnosis combined with clinical characteristics, autoantibodies, and immunoglobulin levels with special emphasis on pathological characteristics of liver tissue. Anti-HBc-positive patients using immunosuppressant should be carefully monitored for HBV DNA and anti-HBV treatment should be given if necessary.

How does ultrasonic cavitation remove dental bacterial biofilm?

Bacterial biofilm accumulation is problematic in many areas, leading to biofouling in the marine environment and the food industry, and infections in healthcare. Physical disruption of biofilms has become an important area of research. In dentistry, biofilm removal is essential to maintain health. The aim of this study is to observe biofilm disruption due to cavitation generated by a dental ultrasonic scaler (P5XS, Acteon) using a high speed camera and determine how this is achieved. Streptococcus sanguinis biofilm was grown on Thermanox™ coverslips (Nunc, USA) for 4 days. After fixing and staining with crystal violet, biofilm removal was imaged using a high speed camera (AX200, Photron). An ultrasonic scaler tip (tip 10P) was held 2 mm away from the biofilm and operated for 2 s. Bubble oscillations were observed from high speed image sequences and image analysis was used to track bubble motion and calculate changes in bubble radius and velocity on the surface. The results demonstrate that most of the biofilm disruption occurs through cavitation bubbles contacting the surface within 2 s, whether individually or in cavitation clouds. Cleaning occurs through shape oscillating microbubbles on the surface as well as through fluid flow.

[Comparison of long-term efficacy between watch and wait strategy and total mesorectal excision in locally advanced rectal cancer patients with clinical complete response after neoadjuvant therapy].

Objective: To compare long-term efficacy between watch and wait (W&W) strategy and total mesorectal excision (TME) in patients who were diagnosed with locally advanced rectal cancer (LARC) and attained clinical complete response (cCR) after neoadjuvant chemoradiotherapy (nCRT). Methods: A retrospective cohort study was carried out. A total of 238 patients with stage II-III LARC exhibiting cCR after nCRT in Sun Yat-sen University Cancer Center from September 16, 2010 to January 9, 2018 were enrolled. Patients who were diagnosed with other malignant tumor within 5 years, did not receive regular follow-up in our center for more than 1 year and had no complete examination items after nCRT were excluded. Of 238 patients, 151 were male and 87 were female with a median age of 57 (27-83) years old. According to TNM stage, 61 cases were cII, 177 cases were cIII. Concurrent chemoradiotherapy (CCRT) was performed in 20 patients. CCRT plus induction/consolidated chemotherapy was performed in 218 patients. Intensity-modulated radiotherapy (IMRT) was applied to radiotherapy. The median radiation dose was 50 Gy/25 Fr for both the primary tumor and clinical target volumes, and the total dose was 45.0 to 50.6 Gy for 227 patients. In 27 patients, single-agent fluorouracil or capecitabine was used as concurrent chemotherapy. But in the other 211 patients, a combined regimen of oxaliplatin and fluorouracil or capecitabine was used. After nCRT, 59 and 179 patients received W&W (W&W group) and TME 6-12 weeks later (TME group), respectively. After the ending of treatment, patient was interviewed one time every 3 months and after 3 years, one time every six months. Overall survival (OS) rate, distant-metastasis-free survival (DMFS) rate, and local-recurrence-free survival (LRFS) rate were compared between two groups. The salvage treatment and sphincter preservation rate were analyzed. The survival curve was drawn with Kaplan-Meier method and evaluated by log-rank method. Results: In the cases treated with TME, the median interval from nCRT to surgery was 59 days. The postoperative pCR rate was 63.1%(113/179). The median follow-up time of the whole cohort was 41.8 (12.0-99.0) months. The 3-year and 5-year OS rates were 98.4% and 96.5%; the 3-year and 5-year LRFS rates were 96.5% and 96.5%; the 3- and 5-year DMFS rates were 91.0% and 87.9%, respectively. The 3-year OS rates in the W&W group and the TME group were 100% and 97.9%; the 5-year OS rates in W&W group and the TME group were 90.6% and 97.9% (P=0.339); The 3-year local recurrence rate (LRR) in the W&W group was 12.9% (7 cases recurred within 2 years), which was significanthy higher then that in the TME group (0.6%, P=0.003). Salvage surgery was successful in 5/6 cases. After salvage surgery, LRFS rate was not significantly different between the two groups (P=0.137). The 3-year DMFS rate in the W&W group and the TME group were 88.4% and 81.1%, whose difference was not significant (P=0.593). Recurrence with simultaneous metastasis was seen in 3/7 cases of the W&W group. The sphincter was preserved in 89.8% (53/59) of patients in the W&W group, which was significantly higher than 73.7% (132/179) in the TME group (P<0.001). When distance of tumor from the anal verge was ≤ 5 cm, the sphincter preservation rate (SPR) in the W&W group was 88.0% (44/50), which was significantly higher than the 54.4% (56/103) in the TME group (P<0.001). Conclusions: W&W is safe and feasible for patients with LARC and cCR after nCRT. The results should be verified by further clinical trials.

Numerical investigation of cavitation generated by an ultrasonic dental scaler tip vibrating in a compressible liquid.

Bacterial biofilm accumulation around dental implants is a significant problem leading to peri-implant diseases and implant failure. Cavitation occurring in the cooling water around ultrasonic scaler tips can be used as a novel solution to remove debris without any surface damage. However, current clinically available instruments provide insufficient cavitation around the activated tip surface. To solve this problem a critical understanding of the vibro-acoustic behaviour of the scaler tip and the associated cavitation dynamics is necessary. In this research, we carried out a numerical study for an ultrasound dental scaler with a curved shape tip vibrating in water, using ABAQUS based on the finite element method. We simulated the three-dimensional, nonlinear and transient interaction between the vibration and deformation of the scaler tip, the water flow around the scaler and the cavitation formation and dynamics. The numerical model was well validated with the experiments and there was excellent agreement for displacement at the free end of the scaler. A systematic parametric study has been carried out for the cavitation volume around the scaler tip in terms of the frequency, amplitude and power of the tip vibration. The numerical results indicate that the amount of cavitation around the scaler tip increases with the frequency and amplitude of the vibration. However, if the frequency is far from the natural frequency, the cavitation volume around the free end decreases due to reduced free end vibration amplitude.

[Effects and mechanism of digoxin on atrium electrical remodeling and susceptibility of atrial fibrillation in aged rabbits].

Objective: To investigate the effects and mechanism of digoxin on atrium electrical remodeling and susceptibility of atrial fibrillation (AF) in aged rabbits. Methods: Twenty aged male New Zealand rabbits were divided into aged group and aged plus digoxin group (n=10 each). Electrical parameters including heart rate (HR), RR and QT interval, ST segment and P wave dispersion from normal Ⅱ electrocardiogram, and the maximum upstroke velocity (Max(dv/dt)), plateau potential (plateau P), action potential duration of 10%, 20% and 90% (APD(10), APD(20), APD(90)) from recording of monophasic action potential (MAP), as well as atrial effective refractory period (AERP(200)) and dispersion (dERP(200)) with 200 ms of basic cycle length (BCL), and frequency self adaptation of AERP with 300 ms and 150 ms of BCLs (fERP) were recorded and compared between the 2 groups. BCLs and inducibility of AF post programmed electrical stimulation and Burst-pacing in left atrium tissue of rabbits in vivo were also analyzed. The L-type calcium current (I(Ca-L)) in 2 groups were recorded via whole-cell patch clamp technique, and the fluorescence intensity of intracellular free Ca(2+) was detected with Flup-3/AM loading by the laser scanning confocal microscope in enzymatically dissociated single rabbit atrial myocytes. Results: Compared with aged group, the heart rate was faster, RR and QT interval were obvious shorter, ST segment was raised and P wave dispersion was significantly increased in aged plus digoxin group (all P<0.05). Moreover, compared with aged group, the Max(dv/dt) and plateau P were obviously increased, APD(10) and APD(20) were significantly prolongated, and APD(9)0 was significantly shorter in aged plus digoxin group (all P<0.01). Otherwise, the fERP was markedly increased (0.81±0.15 vs. 0.67±0.05), and the induced rate of AF was obviously higher in aged plus digoxin group than in aged group (6/8 vs. 4/9) (all P<0.01). With voltage clamp model, digoxin significantly increased I(Ca-L) of atrial myocytes of aged rabbits, When command potential was 10 mV, the current densities of I(Ca-L) were significantly higher in digoxin group than that in aged group ((15.45±2.38) pA/pF vs. (7.03±1.69) pA/pF, P<0.01). Otherwise, the I-V curve of I(Ca-L) was downward shifted of all I-V curves in digoxin perfused aged atrial cells of rabbits. Moreover, the fluorescence intensities of intracellular free Ca(2+) was significantly higher in aged plus digoxin group than in aged group ((1 748±173) µmol/L vs. (478.13±87.63) µmol/L, P<0.01). Conclusion: Digoxin could aggravate the atrial electrical remodeling in atrium of aged rabbits, facilitate susceptibility of atrial fibrillation in aged rabbit, increased current density of I(Ca-L) and concentration of intracellular free Ca(2+), followed Ca(2+) overload and oscillations might be part of the underlying mechanisms.

[Role of PI3K/Akt signaling pathway in ischemic rats underwent cardiac shock waves therapy].

Objective: To investigate the role of PI3K/Akt signaling pathway in ischemic rats underwent cardiac shock therapy. Methods: Adult male Sprague Dawley (SD) rats weighing 220-250 g were used to establish a heart failure model by ligation of the left anterior descending coronary artery. Rat models were defined by echocardiographic assessment at 4 weeks post operation and heart failure rats were randomly divided into 4 groups,namely heart failure group (HF group, 9 cases),heart failure+cardiac shock waves therapy group (HF+CSWT group, 9 cases),heart failure+inhibitor(HF+LY294002 group, 9 cases),heart failure+cardiac shock waves therapy group+inhibitor (HF+CSWT+LY294002 group, 9 cases),and another 9 sham-operated SD rats served as control group (sham group, 9 cases). At 8 weeks postoperation, echocardiography was used to evaluate cardiac function in each group,myocardial infarct size was measured by TTC staining,the apoptotic index of rats cardiomyocytes were detected by TUNEL method,the myocardial mRNA expression of apoptosis-related factor was detected by real-time quantitative PCR, the protein expression levels of PI3K/Akt signaling pathway and apoptosis-related pathways were detected by Western blot. Results: (1) Eight weeks after operation, left ventricular end diastolic diameter (LVEDD) and left ventricular end systolic diameter (LVESD) were significantly lower in HF+CSWT group than in HF group (all P<0.05), left ventricular ejection fraction (LVEF) and left ventricular shortening rate (LVFS) were significantly higher in HF+CSWT group than in HF group (all P<0.05),LVEF was significantly lower in the HF+ CSWT+ LY294002 group than in HF+ CSWT group (P<0.05). (2) Myocardial infarct size was significantly lower in the HF+ CSWT group than in HF group ((5.57 ± 0.51)% vs. (25.56 ± 0.56)%, P<0.05), which was significantly higher in the HF+CSWT+LY294002 group than in HF+CSWT group ((12.90±2.34)% vs. (5.57±0.51)%,P<0.05). (3) The cardiomyocyte apoptotic index was significantly lower in the HF+CSWT group than in the HF group ((30.25±6.12)% vs. (53.85±9.89)%,P<0.05), which was significantly higher in the HF+CSWT+LY294002 group than in the HF+CSWT group ((46.12±3.42)% vs.(30.25±6.12)%,P<0.05). (4) The myocardial mRNA expression of Bcl-2 was significantly higher, while myocardial mRNA Bax and Caspase-3 expression were significantly lower in HF+CSWT group than in HF group and HF+CSWT+LY294002 group (all P<0.05). (5) The expression levels of p-Akt, Bcl-2 and pro-Caspase-3 in myocardial tissue were significantly higher in the HF+CSWT group than in the HF group and HF+CSWT+LY294002 group (all P<0.05), which were significantly lower in the HF+LY294002 group than in the HF and HF+CSWT+LY294002 groups (all P<0.05). Myocardial Bax protein expression was significantly lower in the HF+CSWT group than in the HF group and the HF+CSWT+LY294002 group (all P<0.05), which was significantly higher in the HF+LY294002 group than in the HF group (P<0.05). Conclusion: CSWT improves cardiac function and inhibits cardiomyocyte apoptosis through PI3K/Akt signaling pathways in this rat HF model.