CDK4/6 inhibition triggers ICAM1-driven immune response and sensitizes LKB1 mutant lung cancer to immunotherapy.

Liver kinase B1 (LKB1) mutation is prevalent and a driver of resistance to immune checkpoint blockade (ICB) therapy for lung adenocarcinoma. Here leveraging single cell RNA sequencing data, we demonstrate that trafficking and adhesion process of activated T cells are defected in genetically engineered Kras-driven mouse model with Lkb1 conditional knockout. LKB1 mutant cancer cells result in marked suppression of intercellular adhesion molecule-1 (ICAM1). Ectopic expression of Icam1 in Lkb1-deficient tumor increases homing and activation of adoptively transferred SIINFEKL-specific CD8+ T cells, reactivates tumor-effector cell interactions and re-sensitises tumors to ICB. Further discovery proves that CDK4/6 inhibitors upregulate ICAM1 transcription by inhibiting phosphorylation of retinoblastoma protein RB in LKB1 deficient cancer cells. Finally, a tailored combination strategy using CDK4/6 inhibitors and anti-PD-1 antibodies promotes ICAM1-triggered immune response in multiple Lkb1-deficient murine models. Our findings renovate that ICAM1 on tumor cells orchestrates anti-tumor immune response, especially for adaptive immunity.

Prognostic factors of pacing-induced cardiomyopathy.

BACKGROUND: The detrimental outcomes of right ventricular pacing on left ventricular electromechanical function ultimately result in heart failure, a phenomenon termed pacing-induced cardiomyopathy (PICM) in clinical research. This study aimed to validate prognostic factors that can be used to identify patients with higher susceptibility to progress to the stage of cardiomyopathy before pacemaker implantation. METHODS: This observational analysis enrolled 256 patients between January 2013 and June 2016, 23 (8.98%) of whom progressed to PICM after 1 year of follow-up. A Cox proportional hazard model was used to analyze the prognostic factors associated with PICM. Dose-response analysis was used to evaluate the relationship between significant indicators in multifactor analysis and PICM. RESULTS: The mean values of left ventricular ejection fraction before and after pacemaker implantation in 23 patients diagnosed with PICM were 62.3% and 42.7%, respectively. Univariate analysis showed that sex, atrio-ventricular block, paced QRS duration, and ventricular pacing percentage were significantly associated with PICM. In the multivariate analysis, male sex (hazard ratio: 1.20, 95% confidence interval [CI]: 1.09-1.33, P < 0.005), paced QRS duration (hazard ratio: 1.95 per 1 ms increase, 95% CI: 1.80-2.12, P < 0.001), and ventricular pacing percentage (hazard ratio: 1.65 per 1% increase, 95% CI: 1.51-1.79, P < 0.001) were independent prognostic factors associated with the development of PICM. The ventricular pacing percentage and paced QRS duration level defined by the dose-response analysis were positively associated with PICM (P < 0.05). CONCLUSIONS: Our findings indicated that paced QRS duration and ventricular pacing percentage were the most sensitive prognostic factors for PICM.

Clinicopathological features and prognostic validity of the European Neuroendocrine Tumor Society (ENETS) and American Joint Committee on Cancer (AJCC) 8th staging systems in colonic neuroendocrine neoplasms.

PURPOSE: This study aimed to investigate the characteristics of colonic neuroendocrine neoplasms (NENs) and to validate the prognostic value of the European Neuroendocrine Tumor Society (ENETS) and American Joint Committee on Cancer (AJCC) 8th staging systems. METHODS: A total of 167 and 1248 patients with colonic NENs from 12 medical centers across China and from the Surveillance, Epidemiology, and End Results (SEER) cancer registry in the United States, respectively, were reviewed. Patients were staged according to the ENETS and AJCC 8th staging systems. RESULTS: Clinicopathological features of colonic NENs in the Chinese cohort and SEER cohort were significantly distinct. In both the Chinese cohort and the SEER cohort, colonic neuroendocrine carcinoma (NEC) and mixed adeno-neuroendocrine carcinoma (MANEC) were more frequent in the midgut than in the hindgut. Tumors originating from the midgut tended to be larger and at a more advanced stage than those from the hindgut. The AJCC 8th staging system and the ENETS system appeared to have similar prognostic ability for colonic NEC/MANEC. CONCLUSIONS: Our study revealed that tumors originating from the midgut and the hindgut shared different clinicopathological features. The AJCC 8th staging system and the ENETS system appeared to have similar prognostic ability for colonic NEC/MANEC.

Perioperative management of antithrombotic therapy in patients receiving cardiovascular implantable electronic devices: a network meta-analysis.

PURPOSE: Network meta-analysis (NMA) has advantages including being able to simultaneously compare and rank multiple treatments over traditional meta-analysis. We evaluated by a NMA the optimal antithrombotic strategy during the perioperative period of implantation of cardiovascular implantable electronic devices (CIEDs). METHODS: We performed a network meta-analysis of observational studies (cohort and case-control studies). The eligible studies tested the following antithrombotic therapy during the CIED placement: aspirin, clopidogrel, warfarin, novel oral anticoagulants (NOACs), and heparin bridging. RESULTS: Thirty-one observational studies with 119 study arms were included (41,174 patients receiving long-term antithrombotic therapy; median age, 72.6 years; 70.1% males; median follow-up, 3.6 years). Aspirin (4.26 [2.88-7.22]), warfarin (3.37 [2.17-5.23]), and clopidogrel (3.30 [1.49-5.88]) reduced the risk of bleeding as compared with heparin bridging, and there was no significance difference between continued NOACs and heparin bridging (0.67 [0.21-2.18]). The comparison of commonly used protocols in the management of anticoagulant therapy revealed that continued warfarin (0.38 [0.20-0.74]), continued NOACs (0.19 [0.04-0.89]), and heparin bridging therapy (0.01 [0.05-0.21]) increased the risk of bleeding as compared that of control, and continued warfarin (3.74 [1.96-7.16]), interrupted warfarin (4.89 [2.20-10.88]), and interrupted NOACs (12.5 [1.25-100]) reduced the risk of bleeding compared with that of heparin bridging. CONCLUSIONS: Among various antithrombotic drugs, aspirin had the lowest bleeding risk, followed by warfarin, clopidogrel and NOACs, and heparin, with the greatest bleeding risk. NOACs therapy appears safe and effective, and interrupted NOACs may be the optimal anticoagulation protocol for use during the perioperative period of CIED implantation.

Non-invasive ventilation improves hemorheology status in hypoxemic patients with acute myocardial infarction after PCI.

BACKGROUND: Hypoxemia sometimes occurs in the emergency room in the patients with acute myocardial infarction (AMI) after percutaneous coronary intervention (PCI), even in those with administration of conventional high-flow oxygen inhalation. The objective of the present study was to evaluate the effectiveness of non-invasive ventilation (NIV) in improving blood oxygen content and hemorheology in patients with AMI and hypoxemia. METHODS: This prospective study enrolled 50 consecutive eligible patients with AMI (aged 72.3 ± 9.5 years), who had undergone PCI and been administered high-flow oxygen but still had hypoxemia. Blood was taken before NIV and at 0.5, 1, and 2 h after NIV. Blood gases, hemorheological variables including erythrocyte deformability, erythrocyte aggregation, erythrocyte osmotic fragility, membrane fluidity, and oxidative stress level were measured. RESULTS: Blood PaO2 increased to normal by 1 h after NIV. Assessed hemorheological variables had all improved and plasma malondialdehyde concentration decreased significantly after 2 h of NIV. CONCLUSIONS: Our data suggest that NIV can help to improve blood oxygen content, hemorheological status, and minimize plasma lipid peroxidation injury in hypoxemic patients with AMI who have undergone PCI.

Stenting versus non-stenting treatment of intermediate stenosis culprit lesion in acute ST-segment elevation myocardial infarction: a multicenter randomized clinical trial.

BACKGROUND: The benefit/risk ratio of stenting in acute ST-segment elevation myocardial infarction (STEMI) patients with single vessel intermediate stenosis culprit lesions merits further study, therefore the subject of the present study. METHODS AND RESULTS: It was a prospective, multicenter, randomized controlled trial. Between April 2012 and July 2015, 399 acute STEMI patients with single vessel disease and intermediate (40%-70%) stenosis of the culprit lesion before or after aspiration thrombectomy and/or intracoronary tirofiban (15 µg/kg) were enrolled and were randomly assigned (1: 1) to stenting group (n = 201) and non-stenting group (n = 198). In stenting group, patients received pharmacologic therapy plus standard percutaneous coronary intervention (PCI) with stent implantation. In non-stenting group, patients received pharmacologic therapy and PCI (thrombectomy), but without dilatation or stenting. Primary endpoint was 12-month rate of major adverse cardiac and cerebrovascular events (MACCE), a composite of cardiac death, non-fatal myocardial infarction (MI), repeat revascularization and stroke. Secondary endpoints were 12-month rates of all cause death, ischemia driven admission and bleeding complication. Median follow-up time was 12.4 ± 3.1 months. At 12 months, MACCE occurred in 8.0% of the patients in stenting group, as compared with 15.2% in the non-stenting group (adjusted HR: 0.42, 95% CI: 0.19-0.89, P = 0.02). The stenting group had lower non-fatal MI rate than non-stenting group, (1.5% vs. 5.5%, P = 0.03). The two groups shared similar cardiac death, repeat revascularization, stroke, all cause death, ischemia driven readmission and bleeding rates at 12 months. CONCLUSIONS: Stent implantation had better efficacy and safety in reducing MACCE risks among acute STEMI patients with single vessel intermediate stenosis culprit lesions.

Neuroendocrine-like cells -derived CXCL10 and CXCL11 induce the infiltration of tumor-associated macrophage leading to the poor prognosis of colorectal cancer.

Our previous study revealed that neuroendocrine differentiation in colorectal cancer is one of the important factors leading to worse prognosis. In this study, we apply immunohistochemical staining, Western-blot, RT-PCR and ELISA to investigate the underlying mechanism that how the neuroendocrine differentiation to affect the prognosis of colorectal cancer. The interaction of colorectal cancer cells, neuroendocrine-like cells and tumor-associated macrophages in colorectal cancer progress is also investigated. By analyzing 82 cases of colorectal cancer patients treated in our institution, we found that colorectal adenocarcinoma with neuroendocrine differentiation had increasing number of tumor-associated macrophages and worse prognosis. Further evaluation of cytology showed that neuroendocrine cells have the ability to recruit tumor-associated macrophages to infiltrate the tumor tissue, and the tumor-associated macrophages enhance the proliferation and invasion abilities of the colon cancer cells. Moreover, we confirmed that CXCL10 and CXCL11 are the key chemokines in neuroendocrine-like cells and they promote the chemotaxis activity of tumor-associated macrophages. The secretion of CXCL10 and CXCL11 by neuroendocrine-like cells can recruit tumor-associated macrophages to infiltrate in tumor tissues. The latter enhances the proliferation and invasion of colorectal cancer cell and lead to poor prognosis.

Activation of protein kinase C ε enhanced movement ability and paracrine function of rat bone marrow mesenchymal stem cells partly at least independent of SDF-1/CXCR4 axis and PI3K/AKT pathway.

OBJECTS: to probe into the effects of PKCε on migration and paracrine functions of stem cells and potential molecular mechanisms. METHODS: Bone Marrow mesenchymal stem cells (BMMSCs) were obtained from rat femur and passaged. mRNA and protein levels of capital proteins in PKCε signaling, SDF-1/CXCR4 axis and PI3K/AKT pathway in the MSCs in different conditions treating with PKC agonist, specific PKCε inhibitor, CXCR4 antagonist or PI3K inhibitor for 24 hours were analyzed by real-time PCR and western blot, and migration abilities were observed by migration assay in vitro and the changes of paracrine factors in different treatments were analyzed by protein clips assay. RESULTS: the levels of p-JNK, p-P38MAPK, SDF-1, CXCR4, PI3K and p-AKT increased significantly after treating with PKC agonist (P < 0.05) and decreased obviously after treating with specific PKCε inhibitor. Migration ability and paracrine function of MSCs were enhanced in PMA group and attenuated in PKCε inhibitor group, and inhibiting activity of CXCR4 or PI3K attenuated the effects of PKCε, but not abolished completely. CONCLUSION: There was cross-talking between PKCε signaling and SDF-1/CXCR4 axis and PI3K/AKT pathway in signal transduction of MSCs. Activating PKCε could improve migration ability and paracrine function of MSCs partly at least independent of SDF-1/CXCR4 axis and PI3K/AKT pathway.

Prognostic significance of neuroendocrine differentiation in colorectal adenocarcinoma after radical operation: a meta-analysis.

BACKGROUND: The phenomenon of neuroendocrine differentiation has been observed in colorectal adenocarcinoma. However, the ability of neuroendocrine differentiation to predict the outcome of colorectal adenocarcinoma remains controversial. METHODS: We conducted an extensive search of research studies related to neuroendocrine differentiation using scientific databases, including the PubMed, Embase, OVID, BIOSIS Previews, and Cochrane Central Register of Controlled Trials (up to July, 2013), according to the established search terms. RevMan version 5.2 statistical program was used to analyze the data. An odds ratio (OR) with a 95% confidence interval (CI) was used for the dichotomous data. RESULTS: Eleven studies with a total of 1,587 patients were included. Patients with neuroendocrine differentiation who underwent a radical operation had a lower 5-year survival rate (pooled OR 0.60, 95% CI 0.37-0.97) compared with those without neuroendocrine differentiation, with evidence of moderate heterogeneity (I (2) = 37%, p = 0.10). A sensitivity analysis and meta-regression showed that the different classification criteria of neuroendocrine differentiation used in these studies were the main source of heterogeneity. When the strong positive rates of neuroendocrine differentiation indicators between the higher (stage III + IV) and the lower (stage I + II) clinical stages were compared, the pooled OR was 1.84 (703 patients; 95% CI 0.98-3.43) without evidence of heterogeneity (I (2) = 0 %, p = 0.89). However, comparisons between consecutive stages showed different ORs: stage II vs. I (203 patients; OR = 0.52, 95% CI 0.17-1.56), stage III vs. II (569 patients; OR = 2.27, 95% CI 1.03-4.98), and stage IV vs. III (375 patients; OR = 1.81, 95% CI 1.00-3.29). CONCLUSION: The patients with strong positive indicators of neuroendocrine differentiation had a lower 5-year survival rate. The ability to detect neuroendocrine indicators using conventional methods could improve the prognosis judgment of colorectal adenocarcinoma.

Clinicopathological features and prognosis of gastroenteropancreatic neuroendocrine tumors: analysis from a single-institution.

BACKGROUND: The gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) is the most common type of neuroendocrine neoplasm. We summarized data in our centre to investigate the clinicopathological features, diagnostic methods, therapeutic approaches and prognosis for this neoplasm to increase knowledge of this disease in Asian populations. METHOD: A total of 122 patients treated at Sun Yet-san Memorial Hospital of Sun Yat-sen University between January 2000 and December 2011 were analyzed retrospectively. RESULTS: Pancreas was the most common site of involvement (65/122, 53.3%); this disease has no special symptoms; positive rates of chromogranin A (CgA) and synaptophysin (Syn) were 81.1% and 87.7%, respectively. The positive rate of Syn had statistical difference among the three grades, but not CgA. Some 68 patients had G1 tumors, 32 G2 tumors and 22 G3 tumors, and Chi-square test showed that higher grading was correlated with worse prognosis (χ2=32.825, P=0.0001). A total of 32 patients presented with distant metastasis, and 8 cases emerged during following up. Cox proportional hazards regression modeling showed that the tumor grade (P=0.01), lymphatic metastasis (P=0.025) and distant metastasis (P=0.031) were predictors of unfavorable prognosis. The overall 5-year survival rate was 39.6%, the 5-year survival rate of G1 was 55.7%, and the G2 and G3 were 34.2% and 0%, respectively. CONCLUSIONS: The incidence of gastroenteropancreatic neuroendocrine tumors has risen over the last 12 years. All grades of these diseases metastasize readily, and further research regarding the treatment of patients after radical surgery is needed to prolong disease-free survival.

Serum uric acid in patients with acute ST-elevation myocardial infarction.

BACKGROUND: Few studies investigated serum uric acid levels in patients with acute Stelevation myocardial infarction (STEMI). The study was to assess the clinical value of serum uric acid levels in patients with acute ST-elevation myocardial infarction (STEMI). METHODS: Totally 502 consecutive patients with STEMI were retrospectively studied from January 2005 to December 2010. The level of serum lipid, echocardiographic data and in-hospital major adverse cardiovascular events (MACE) in patients with hyperuricemia (n=119) were compared with those in patients without hyperuricemia (n=383). The relationship between the level of serum uric acid and the degree of diseased coronary artery was analyzed. All data were analyzed with SPSS version 17.0 software for Student's t test, the Chi-square test and Pearson's correlation coefficient analysis. RESULTS: Serum uric acid level was positively correlated with serum triglyceride level. Hyperlipidemia was more common in hyperuricemia patients than in non-hyperuricemia patients (43.7% vs. 33.7%, P=0.047), and serum triglyceride level was significantly higher in hyperuricemia patients (2.11±1.24 vs. 1.78±1.38, P=0.014). But no significant association was observed between serum uric acid level and one or more diseased vessels (P>0.05). Left ventricular end-diastolic diameter (LVEDd) was larger in hyperuricemia patients than in non-hyperuricemia patients (53.52±6.19 vs. 52.18±4.89, P=0.041). The higher rate of left systolic dysfunction and diastolic dysfunction was discovered in hyperuricemia patients (36.4% vs. 15.1%, P<0.001; 68.2% vs. 55.8%, P=0.023). Also, hyperuricemia patients were more likely to have in-hospital MACE (P<0.05). CONCLUSIONS: Serum uric acid level is positively correlated with serum triglyceride level, but not with the severity of coronary artery disease. Hyperuricemia patients with STEMI tend to have a higher rate of left systolic dysfunction and diastolic dysfunction and more likely to have more in hospital MACE.

Proteomic analysis identifies translationally controlled tumor protein as a mediator of phosphatase of regenerating liver-3-promoted proliferation, migration and invasion in human colon cancer cells.

BACKGROUND: Considerable evidence suggests that phosphatase of regenerating liver-3 (PRL-3) plays multiple roles in cancer metastasis; however, the molecular mechanisms remain largely unknown. The aim of this study was to identify proteins associated with PRL-3-promoted colon cancer metastasis, by comparative proteomic analysis. METHODS: Proteomes of human colon cancer LoVo cells transfected with PRL-3 gene (LoVo-PRL-3) or empty vector PAcGFP-C3 (LoVo-control) were compared using 2D gel electrophoresis. Proteins that varied significantly in concentration were selected and identified using mass spectrometry. Expression of translationally controlled tumor protein (TCTP) mRNA and protein in LoVo-PRL-3 and LoVo-control cells was detected by real-time PCR and Western blotting. Small interfering RNA (siRNA) targeting TCTP was used for silencing TCTP expression in LoVo-PRL-3 cells. Functional significance of TCTP in PRL-3-promoted colon cancer cell proliferation, migration and invasion was investigated by Cell Counting Kit-8 assay and transwell chamber. RESULTS: Seventeen proteins displaying significant and reproducible differences between LoVo-PRL-3 and LoVo-control cells were identified. Ten proteins were upregulated and seven were downregulated in LoVo-PRL-3 cells when compared with LoVo-control cells. Eight identified proteins are associated with distinct steps of tumor metastasis: ubiquitin-like protein ISG15, interleukin-18, TCTP, serpin B5, annexin A3, macrophage-capping protein, ATP-dependent RNA helicase DDX3X, and cathepsin D. Real-time PCR and Western blotting results showed that both TCTP mRNA and protein were significantly increased in LoVo-PRL-3 cells compared to LoVo-control cells. Transfection with TCTP siRNA significantly reduced the expression of both mRNA and protein levels of TCTP in LoVo-PRL-3 cells. Knockdown of TCTP by siRNA inhibited PRL-3-promoted proliferation, migration and invasion of LoVo-PRL-3 cells. CONCLUSION: Our results imply that TCTP might be a mediator of PRL-3-promoted proliferation, migration and invasion of human colon cancer cells.

Electrophysiologic characteristics and radiofrequency ablation of focal atrial tachycardia arising from non-coronary sinuses of Valsalva in the aorta.

OBJECTIVES: Focal atrial tachycardia (AT) arising from non-coronary cusp (NCC) is very rare, and the experience in catheter ablation of this kind of tachycardia remains limited. This study describes the electrophysiologic characteristics and radiofrequency ablation of AT arising from NCC. METHODS AND RESULTS: The study population consisted of five consecutive patients (three females and two males; age 37-68 years) with AT arising from NCC. The morphology of P waves was described as positive, negative, isoelectric, or biphasic (positive-negative or negative-positive). The atrial mapping was performed during tachycardia to define the earliest atrial activation site. Mean tachycardia cycle length of AT in five patients was 363 +/- 44 ms. P-wave morphology was predominantly upright or biphasic in lead II, III, and aVF, inverted in aVR. Positive P-wave morphology was seen in lead aVL in all five patients. The precordial leads were negative-positive in V(1) and V(2), negative-positive or positive in lead V(3)-V(5), and positive in lead V(6). All the five patients underwent successful radiofrequency ablation within NCC. During a follow up of > 3 months, no patient presented with a recurrence. CONCLUSIONS: This study demonstrated that mapping and ablation of focal AT arising from NCC is safe and effective. When earliest activation was recorded in the proximal electrode of the His-bundle catheter, but radiofrequency ablation in this region cannot successfully eliminated the tachycardia, the AT should be considered to arise from NCC especially when P-wave morphology was initially negative with a late positive component in right precordial leads, upright or biphasic in inferior leads.

[Echocardiographic evaluation of left ventricular geometry and function in maintenance hemodialysis uremic patients].

OBJECTIVE: To assess left ventricular (LV) geometry, LV diastolic and systolic function in maintenance hemodialysis uremic patients. METHODS: Forty uremic patients and forty-five normal subjects were included in this study. LV volume, LV mass index (LVMI), relative wall thickness (RWT), LV mass and diastolic volume ratio (LVM/EDV) were measured. Mitral flow E velocity and A velocity ratio, deceleration time, mitral flow E velocity and mitral annulus Ea velocity ratio (E/Ea), pulmonary vein flow S velocity and D velocity ratio, atrial flow reversal velocity of pulmonary vein flow, mitral inflow propagation velocity, left atrium volume (LAV) and pulmonary artery systolic pressure (PASP) were determined for diastolic function evaluation. LV ejection fraction (LVEF) and single volume (SV) were derived from 3D echocardiography, systolic velocity of mitral valve annulus (Sa) by pulse tissue Doppler imaging (TDI) were used to evaluate systolic function. The time to peak systolic velocity (Ts) and early diastole velocity (Td) of LV 12 segments were measured using TDI. The maximal difference of Ts and Td (Ts-Dif and Td-Dif) were calculated to assess LV systolic and diastolic asynchrony. RESULTS: RWT, LVMI and LVM/EDV were significantly increased in uremic patients. There were 50% concentric, 17.5% eccentric hypertrophy and 17.5%concentric remodeling, respectively in uremic patients. The indices for LV diastolic function (E/Ea, LAV and PASP) were significantly higher in uremic patients than those in control subjects (P < 0.01). About 85% of the diastolic dysfunction in uremic patients presented as impaired relaxation pattern and 32.5% as increased filling pressure. LVEF and SV were similar between uremic patients and control subjects. Sa was significantly lower in uremic group than that in controls (P < 0.05). Ts-Dif was similar between the 2 groups while Td-Dif was significantly higher in uremic patients than control subjects (P < 0.05). CONCLUSION: LV hypertrophy, LV mass increase and LV diastolic dysfunction were the major characteristic of myocardial injury in uremia patients.

[Rapamycin-loaded poly (lactic-co-glycolic) acid nanoparticles for intraarterial local drug delivery: preparation, characterization, and in vitro/in vivo release].

OBJECTIVE: To sought to engineer and characterize a biodegradable nanoparticles (NPs) containing rapamycin which use poly (lactic-co-glycolic) acid (PLGA) as the carrier matrix and to assess its in vivo release characteristics by local drug delivery system intravascularly. METHODS: Rapamycin-loaded PLGA NPs were prepared by an emulsification/solvent evaporation technique, and NPs size distribution was assessed by submicro laser defractometer. The particle morphology was observed by scanning electron microscopy. In vitro release from the NPs was performed in TE buffer at 37 degrees C under rotation utilizing double-chamber diffusion cells on a shake stander. In vivo NPs intravascular local delivery were performed by DISPATCH catheter in New Zealand rabbit abdominal aorta and Chinese experimental mini-pigs coronary artery models. RESULTS: Biodegradable rapamycin loaded PLGA NPs were constructed successfully by emulsification solvent-evaporation technique. The diameter of rapamycin-PLGA NPs was around 246.8 nm with very narrow size distribution, and rapamycin-NPs showed good spherical shape with smooth uniform surface. Rapamycin loaded in NPs were around was 19.42%. Encapsulation efficiency of drug was over 77.53%. The in vitro release of rapamycin from NPs showed that 75% of the drug was sustained released over 2 weeks and controlled release in a linear pattern. After a single 10 minutes infusion of rapamycin-PLGA NPs suspension (5 mg/ml) under 20.27 kPa through DISPATCH catherter in vivo, the mean rapamycin levels at 7 day and 14 day were (2.438 +/- 0.439) and (0.529 +/- 0.144) microg/mg of the dry-weight of the artery segments (2 cm) which local delivery were administrated. CONCLUSIONS: PLGA NPs controlled drug delivery system for intraarterial local anti-proliferative drug delivery can potentially improve local drug concentration and prolong drug residence time in animal model in vivo. It should be appropriate for further study of its therapy efficiency in human.

[The effects of various beta-blockers on myocardial gap junction structure in rat with myocardial ischemia-reperfusion injury].

OBJECTIVE: To compare the effects of carvedilol, metoprolol and propranolol on myocardial gap junction (GJ) structure in rat with myocardial ischemia and reperfusion injury. METHODS: Rats were divided randomly into five groups: sham operation group (SO), myocardial ischemia and reperfusion group (IR), IR + carvedilol group (CV), IR + metoprolol group (MT), and IR + propranolol group (PP). The left anterior descending branch was ligated for 30 minutes and reperfused for 4 hours (IR). After 4 h reperfusion, the distribution and composition of gap junctional connexin 43 (CX43) were observed by immunofluorescence and laser scanning confocal microscopy (LSCM), and the quantification of CX43 was measured by LSCM. RESULT: Compared with SO group, IR resulted in abnormal distribution and composition of CX43-GJ and the impairment of CX43-GJ was significantly attenuated by CV, MT and PP treatments with the best effect observed in CV group (P<0.05 vs. MT and PP). CONCLUSION: These results suggest that beta-blockers, especially, carvedilol, could significantly attenuate IR induced CX43-GJ impairment.

[Effects and the mechanism of carvedilol on gap junctional intercellular communication in rat myocardium].

OBJECTIVE: To examine the effects of carvedilol on myocardial ischemia and reperfusion injury and on gap junctional intercellular communication (GJIC). METHODS: The left coronary artery was occluded for 30 min and reperfused for 4 h. The activity of creatine phosphokinase (CK), lactate dehydrogenase (LDH) and the infarct size were measured. Isolated buffer-perfused hearts were divided randomly into four groups, sham operation (SO), myocardial ischemia and reperfusion (IR), carvedilol (CV) and heptanol (a gap junctional inhibitor) (HT). The effect of carvedilol on GJIC was measured by a modification of Scrape-loading and dye transfer method, and the state of CX43 phosphorylation was evaluated by Western blot. RESULTS: Compared with the SO group, Increased CK, LDH and infarct size were found in the IR group after 4 h reperfusion. GJIC in the IR group was not inhibited, but dephosphorylated CX43 was increased after 30 minutes of ischemia. Carvedilol decreased CK, LDH and infarct size compared with the IR rats; after 30 minutes of ischemia, both carvedilol and heptanol significantly reduced the GJIC, associated with a significant augmentation of dephosphorylated CX43. CONCLUSIONS: These results suggest that carvedilol reduces GJIC during ischemia presumably by dephosphorylating Cx43, which may be one of the mechanisms of lessening myocardial ischemia-reperfusion injury.