Implantation of the Micra transcatheter pacing system: A single center North India experience

BackgroundThe leadless pacemaking transcatheter system, Micra, is a miniaturized, single-chamber pacemaker system. We report herein our experience with implantation of the Micra TPS system.ObjectiveThe current study was conducted to evaluate the safety and efficacy of the leadless Micra Transcatheter Pacemaker System (Medtronic).Research design and methodsThis was a prospective single centre nonrandomized study without controls. A transcatheter pacemaker was implanted in patients who had guideline based indications for ventricular pacing. 28 subjects were screened based on the selection criteria. Mica TPS was implanted. Parameters assessed were: duration of procedure (from femoral vein puncture to venous access closure), fluoroscopy time, number of device repositions, periprocedural electrical measurements (sensing, threshold and impedance) and in-hospital, intermediate to long term adverse events related to procedure.Result and conclusions: The device was successfully implanted in 28 subjects. The mean intraoperative sensing value was 9.04 ± 1.5 mV and the impedance was 766.89 ± 213.9 Ω. At discharge from hospital, those values were 13.2 ± 15.83 mV and 855 ± 111.7, respectively. The recommended pacing threshold value as achieved in all subjects was 0.78 V, i.e. ≤ 1 V at 0.24 ms. There was no adverse event or complications reported for any of the subjects. Mean time from hospitalization to discharge was 1.5 days. Implantation of leadless pacemakers is feasible, safe and provides advantages over the conventional system.     

Leadless pacemaker implantation for pediatric patients through internal jugular vein approach: A case series of under 30 kg

BackgroundWe demonstrate a case series of 8 pediatric patients, all under 30 kg, who had leadless pacemaker implants via the internal jugular vein.MethodsA retrospective review of pediatric leadless pacing placement via the internal jugular vein at the University of Minnesota Masonic Children's Hospital and UC Davis Medical Center from 2018 through 2021 was performed. Rationales for pacing, demographics of patients, pacing thresholds, and longevity of devices were recorded.ResultsEight internal jugular pacemaker insertions were performed successfully in patients weighing between 10.9 kg and 29 kg. Five patients had Micra implantation via the right internal jugular vein, whereas 3 patients had insertion via the left internal jugular vein. No surgical cut-downs were performed. No venous complications occurred. Up to 3 years of follow-up were noted.ConclusionLeadless pacemaker implantation, via left or right internal jugular veins, is feasible without surgical cutdown in patients <30 kg     

Transcatheter leadless permanent pacemaker in complex congenital heart disease with interrupted inferior vena cava: A challenging implantation

31 years lady with complete atrioventricular canal defect, large primum atrial septal defect (ASD), inlet ventricular septal defect (VSD) and Eisenmenger syndrome, presented with atrial flutter and complete heart block. She was not suitable for corrective cardiac surgery and not yet indicated for heart-lung transplantation. She was advised single chamber permanent pacemaker and eventually Micra VR transcatheter leadless pacemaker was finalised for her. Transcatheter leadless pacemaker was deployed in her RV septum despite some unforeseen technical problems. This patient had intrahepatic interruption of IVC with Azygous continuation draining into SVC but this altered venovascular course was detected only fluoroscopically midway during the pacemaker implantation procedure and this was not detected in the preprocedural transthoracic echocardiography. This abnormal venous course was clearly demonstrated in the cardiac CT which was performed only after completion of the pacemaker implantation procedure in this patient. The technical challenges encountered mainly were mostly during the manipulation of the 27F delivery catheter of Micra through this altered cardiovascular anatomy via transfemoral approach and also due to the presence of septal defects. Thus, transcatheter leadless permanent pacemaker was implanted successfully through transfemoral access in this complex congenital heart disease with interrupted IVC and azygous continuation. Besides transthoracic echocardiography, it may be better to perform transesophageal echocardiography or even preferably radiological imaging like cardiac CT or MRI prior to transcatheter leadless pacemaker implantation in patients with complex congenital heart disease to understand the cardiovascular anatomy and plan the procedure.     

Genetic contribution between APE1 variants in polycystic ovarian syndrome

IntroductionPolycystic Ovarian Syndrome (PCOS) has been identified as a gynecological, hormonal, and metabolic condition in women of reproductive age. Genetic studies can contribute to understand the pathogenesis of PCOS; which can be beneficial in early diagnosis and long-term management of the disease. Apurinic/apyrimidinic endonuclease 1 (APE1) has been related in the literature to polycystic ovarian syndrome.AimThe purpose of this study was to investigate the effects of ?656 T > G and 1349 T > G single nucleotide polymorphisms (SNPs) in the APE1 gene in Saudi women with PCOS.MethodsThis study includes 100 PCOS women and 100 healthy controls were genotyped for ?656 T > G and 1349 T > G SNPs using PCR-RFLP method. Serum sample was used for FBG and lipid profile tests. The obtained biochemical and genotypes data were entered into Excel and utilized for statistical analysis.ResultsClinical data presented in Table 1 was used to calculate the t-tests between PCOS and control subjects and results indicate age, weight, BMI, TG, LDLC and PCOS family history was associated (p < 0.0001). Genotype and allele frequencies showed the negative association in ?656 T > G SNP (GG vs TT: OR-1.15 (0.61–2.17); p = 0.65 and GG + TG vs TT: OR-1.17 (0.67–2.04); p = 0.57) and positive association in 1349 T > G SNP (GG vs TT: OR-3.52 (1.48–8.36); p = 0.003 and GG + TG vs TT: OR-2.84 (1.27–6.31); p = 0.008) in APE1 gene. Anova analysis was not associated with any one of the involved parameters (p > 0.05).ConclusionThis study found that the 1349 T > G SNP was related with PCOS in Saudi women. However, the ?656SNP had no favorable effect on the APE1 gene.     

Halo-shape technique for leadless pacemaker implantations: A case report

A 92-year-old woman underwent an implantation of a leadless pacemaker (Micra; Medtronic, Inc, Minneapolis, MN) for complete atrioventricular block after a transvenous lead extraction due to a pocket infection of a dual chamber pacemaker. Marked scoliosis and a humpback due to an advanced age made it impossible to direct the tip of the pacemaker delivery catheter towards the right ventricular septum or apex and shape the catheter into a gooseneck-shape. Thus, by attaining a halo-catheter shape of the delivery catheter, the catheter tip could be directed toward the infero-basal portion of the right ventricular septum. The pacemaker was successfully deployed at that site without any complications, and good device parameters were achieved. The halo-shape technique may be also an alternative method for delivering a leadless pacemaker in patients with an unsuccessful delivery of a leadless pacemaker to the right ventricular septum using the conventional gooseneck-shape technique.     

Valoración de niveles de testosterona mediante diferentes métodos analíticos en varones sanos

Plasma testosterone concentrations are essential for the diagnosis of several causes of hypogonadism, including late-onset hypogonadism. Defining the normal range for testosterone concentrations poses certain difficulties due to the changes that occur with age and the variability of the different analytical methods used.ObjectivesTo study normal ranges of testosterone in healthy young men and to compare the results of distinct analytical methods.Material and methodsWe recruited 20 healthy men with a mean age of 24.5 years (standard deviation (SD): 5.04) and a mean body mass index (BMI) of 23.8% (SD: 3.3). Total testosterone (TT) was measured by immunochemiluminescence (ICLA) and free testosterone (FT) by radioimmunoassay (RIA). Calculated free testosterone (FTc) and bioavailable testosterone (BT) were calculated using Vermeulen's formula. Serum lutropin (LH), follitropin (FSH) and sex hormone binding globulin (SHBG) were measured by immunoradiometric assays (IRMA).ResultsThe mean concentrations were 20 nmol/l (SD: 4.96) for TT, 0.054 nmol/L (SD: 0.01) for FT, 0.3834 nmol/L (SD: 0.09) for FTc and 9.9 nmol/L (SD: 2.8) for BT. There was no correlation between testosterone measured by different methods other than an association between FT and FTc (r=0.662, p<0.003) and between FTc and BT (r=0.979, p<0.0001). An inverse correlation was found between BMI and TT concentrations (r: ?0.52, p<0.017).ConclusionsThe normal range for testosterone in healthy young men should be established in each laboratory based on the analytical method used.     

Conventional single-chamber pacemakers versus transcatheter pacing systems in a “real world” cohort of patients: A comparative prospective single-center study

PurposeDespite the developments in conventional transvenous pacemakers (VVI-PM), the procedure is still associated with significant complications. Although there are no prospective clinical trials that compared VVI-PM with transcatheter pacemaker systems (TPS).MethodsThis is a prospective, observational, single-center study that included all patients with an indication for a single-chamber pacemaker implant within a 4-year period. All clinical, ECG and echocardiographic characteristics at implant, electrical parameters, associated complications and mortality were analyzed. A Cox survival model and a Bayesian cohort analysis were performed for differences in complication rates between groups.ResultsThere were 443 patients included (198 TPS and 245 VVI-PM). The mean age was 81.5 years (TPS group, 79.2 ± 6.6 years; VVI-PM group, 83.5 ± 8.9 years). There was a male predominance in TPS group (123, 62.1% vs. 67, 27.3%; p < 0.001). The presence of systolic dysfunction and renal insufficiency were more frequent in VVI-PM group than in TPS patients. Mean follow-up was 22.3 ± 15.9 months. In a multivariable paired data the TPS group presented fewer complications than VVI-PM group (HR = 0.39 [0.15–0.98], p-value 0.013), but major complications were not different (6, 3% vs 14, 5.6% respectively, p = 0.1761). There was no difference in the mortality rate between the groups. The TPS group had less risk than VVI-PM group to have a complication, with a 96% of probability.ConclusionsTPS patients had a lower overall complication rate than VVI-PM patients including matched-pair samples using a Bayesian analysis. These results confirm the safety profile of TPS in clinical practice.     

Protective and pathogenic role of collagen subtypes genes COL4A3 and COL4A4 polymorphisms in the onset of keratoconus in South-Asian Pakistani cohort

Collagen sub-types have an important role in corneal structure and are reported to be an important genetic predictor for keratoconus (KC) development, therefore we assessed the association of collagen subtypes by screening non-synonymous polymorphisms of COL4A3 and COL4A4 in South-Asian (Pakistani) patients.MethodsA total of 257 KC sporadic cases, gender and ethnicity matched 253 control individuals were screened for three non-synonymous single nucleotide polymorphisms (SNPs) rs55703767and rs10178458 in COL4A3 and rs2229814 and one synonymous SNP rs2228555 in COL4A4. The genotyping was done by Competitive Allele specific polymerase chain reaction (PCR) and the data were analyzed statistically.ResultsAmong the studied SNPs, the COL4A3 rs55703767 GT genotype (dominant model (DM): odds ratio (OR) = 0.243, (95 %CI) = 0.16–0.36, p=>0.0001), and allele-G (OR = 0.35, 95 %CI = 0.26–0.48, p < 0.000)), showed protective association against KC development. While COL4A3 rs10178458 CT genotype (DM: OR = 2.11(95 %CI = 1.16–3.85), COL4A4 rs2229814 TT genotype (RM: OR = 147.778(95 %CI = 20.401–1070.439), (p > 0.05) and allele-T (OR = 2.351(95 %CI = 1.826–3.028), (p > 0.05); COL4A4 rs2228555 AG genotype (DM: OR = 2.370(95 %CI = 1.594–3.524) (<0.0001) and GG genotype (RM: OR = 2.347(95 %CI = 1.587–3.472), (p < 0.0001); and allele-G (OR = 2.024(95 %CI = 1.577–2.597), (p > 0.0001) were observed to be disease associated.ConclusionCOL4A3 rs10178458 and COL4A4 SNPs rs2229814 and rs2228555 were found to be pathogenic for KC, whereas COL4A3 rs55703767 was found to play a protective role against KC development in South-Asian (Pakistani) Cohort.     

Allogeneic cord blood regulatory T cells can resolve lung inflammation

Background aimsCD4⁺CD25⁺CD127^lo regulatory T cells (Tregs) are responsible for maintaining immune homeostasis. Tregs can be rendered defective and deficient as a result of the immune imbalance seen in lung injury, and such dysfunction can play a major role in continued tissue inflammation. The authors hypothesized that adoptive therapy with healthy allogeneic umbilical cord blood (UCB)-derived Tregs may be able to resolve inflammation.ResultsEx vivo-expanded UCB Tregs exhibited a unique phenotype with co-expression of CD45RA⁺CD45RO⁺ >80% and lung homing markers, including CD49d. UCB Tregs did not turn pathogenic when exposed to IL-6. Co-culture with increasing doses of dexamethasone led to a synergistic increase in UCB Treg-induced apoptosis of conventional T cells (Tcons), which translated into significantly higher suppression of proliferating Tcons, especially at a lower Treg:Tcon ratio. Multiple injections of UCB Tregs led to their preferential accumulation in lung tissue in an immune injury xenogenic model. A significant decrease in lung resident cytotoxic CD8⁺ T cells (P = 0.0218) correlated with a sustained decrease in their systemic distribution compared with controls (P < 0.0001) (n = 7 per arm) as well as a decrease in circulating human soluble CD40 ligand level (P = 0.031). Tissue architecture was preserved in the treatment arm, and a significant decrease in CD3⁺ and CD8⁺ burden was evident in immunohistochemistry analysis.ConclusionsUCB Treg adoptive therapy is a promising therapeutic strategy for treatment of lung injury.     

Postural stability in young healthy subjects – Impact of reduced base of support,visual deprivation,dual tasking

ObjectiveTo provide normative postural stability data in young subjects.MethodsNinety-six healthy participants (58 W, 28 ± 6y) stood on a force plate during 60 s. We measured effects of support width (feet apart, FA; feet together, FT), vision (eyes open, EO; closed, EC), and cognitive load (single task, ST; dual tasking, DT) on anteroposterior (AP) and medio-lateral (ML) ranges, area and planar velocity of center of pressure (COP) trajectory.ResultsAll variables increased with FT (AP range, +15%; ML, +185%; area, +242%; velocity, +50%, p < 0.0002 for all, MANOVA). Visual deprivation increased COP ranges with added constraints (FT or DT, p = 0.002) and increased velocity in all conditions (FA/ST, +16%; DT, +18%; FT/ST, +29%; DT, +23%, p < 0.0002 for all). Dual tasking reduced COP displacements with FT (AP range, EO, −15%; EC, −11%; ML range, EO, −19%; EC, −13%; area, EO, −40%; EC, −28%, p < 0.0002 for all) and increased velocity in most conditions (FA/EO, +15%; FA/EC, +16%; FT/EO, +7%, p < 0.0002 for all).ConclusionIn young healthy adults, base of support reduction increases COP displacements. Vision particularly affects postural stability with feet together or dual tasking. Dual tasking increases velocity but decreases COP displacements in challenging postural tasks, potentially by enhanced lower limb stiffness.     

Treatment outcomes for childhood acute lymphoblastic leukemia in low-middle income country before minimal residual disease risk stratification

BackgroundOutcome of childhood acute lymphoblastic leukemia (ALL) in low- and middle-income countries is lagging in many aspects including diagnosis, risk stratification, access to treatment and supportive care.Objectiveto report the outcome of childhood ALL at Ain Shams University Children’s Hospitals with the use of risk-based protocols before the implementation of minimal residual disease technology and to evaluate the use of double delayed intensification (DDI) in standard risk patients.MethodsTwo hundred and twenty patients with ALL diagnosed between January 2005 and December 2014 were included in the study. Patients were treated according to a modified CCG 1991 and 1961 for standard and high risk respectively. Patients were stratified into three risk groups: standard risk (SR), high-risk standard arm (HR-SA), and high-risk augmented arm (HR-AA).ResultsAmong the whole cohort, the 10-year event-free survival (EFS) and overall survival (OS) were 78.1% and 84.3% respectively. Patients with Pre-B immunophenotype (IPT) had significantly better outcome than T-cell IPT (EFS 82.0% versus 58.6%, p < 0.001; OS 86.9% versus 69%, p = 0.003 for Pre-B and T-cell respectively). Among the SR group, patients treated with single delayed intensification (SDI) had comparable EFS and OS rates when compared to patients treated with DDI with EFS 82.4% versus 87.5%, p = 0.825 and OS 88.2% versus 93.5%, p = 0.638 for SDI and DDI groups, respectively.ConclusionThe use of risk-based protocol with simple laboratory techniques resulted in acceptable survival outcome in resource limited settings. The use of double delayed intensification showed no survival advantage in patients with standard risk.     

Efficacy of cascade-primed cell infusion as an adjuvant immunotherapy with concurrent chemotherapy for patients with non–small-cell lung cancer: A retrospective observational study with a 5-year follow-up

BackgroundClinical studies have shown the efficacy of combination therapy for various malignancies. In this study, the characteristics, safety and feasibility of use of cascade-primed (CAPRI) cells for the combination treatment of non–small-cell lung cancer (NSCLC) were evaluated both in vitro and in vivo.MethodsSixty-five patients with stage II–IV NSCLC were recruited. Of these patients, 31 patients received CAPRI cell therapy combined with chemotherapy (CAPRI group), and the other 34 patients constituted the control group and received chemotherapy alone. This study primarily aimed to evaluate the overall survival (OS), progression-free survival (PFS), short-term responses and treatment efficacy.ResultsCD83, CD1a, CD80 and CD86 marker levels were significantly upregulated in CAPRI cells. Interferon-γ expression levels were highest in CD3⁺CD8⁺ cells (33.77% ± 4.40%). Furthermore, interleukin-2 levels were highest in CD3⁺CD56⁺ cells (26.73% ± 6.63%), whereas perforin expression levels were similar in CD3⁺CD8⁺ and CD3⁺CD56⁺ cells. Furthermore, CAPRI cells had a better anti-tumor potential in CD3⁺CD56⁺ cells and displayed the highest expression levels of CD107a to H460 and A549 cell lines. The 5-year OS was significantly greater in the CAPRI group than in the control group (P = 0.008), and the PFS of two groups exhibited a significant difference (P = 0.007). Median OS (48 versus 31.6 months; P = 0.004) and PFS (48 versus 36.4 months; P = 0.016) differed between these two groups. Moreover, treatment-associated toxicities were mild and well-tolerated by patients with NSCLC.ConclusionCAPRI cell therapy potentially prolongs the survival of patients with NSCLC when combined with chemotherapy.     

Segmentation d’images de lésions cérébrales primitives en TEP FET : influence du volume de travail

Purpose(1) Evaluate the reproducibility of segmentation methods depending on the preselection region for tumour volume determination on ¹⁸F-fluoro-ethyl-tyrosine (FET) PET. (2) Evaluate the intra and inter-operator reproducibility of the manual delineation. (3) Compare this delineation with the segmentation methods.Materials and methodsEighteen FET PET of patients with glioblastoma were analysed. Preselection regions were determined prior to any segmentation. Two physicians delineated the tumour volume manually. The tumour volume was also delineated with a threshold method (40 and 70% of SUV_max), and a random walk based method. Pearson coefficient (r) (P < 0.05 for r > 0.468) and Jaccard indices (JI) were used to compare the volumes.ResultsManual delineation was reproducible with r = 0.97 and IJ = 0.65 for intra-operator, and r = 0.76 and IJ = 0.45 for inter-operator reproducibility. The preselection regions for a given lesion were different and the segmentation varied with the preselection region: r = 0.55 JI = 0.58; r = 0.85 JI = 0.83; r = 0.70 JI = 0.39 respectively for the threshold of 40%, 70% and the random walk. The segmentation differed form de manual delineation with r = 0.37 and JI = 0.16; r = 0.54 and JI = 0.42; r = 0.43 and JI = 0.37 respectively for the threshold of 40%, 70% and the random walk.ConclusionThe reproducibility of the segmentation methods depends extensively on the preselection region. The intra-operator reproducibility of cerebral lesion delineation on FET PET is satisfactory. The inter-operator reproducibility could be improved.     

Cytotoxic activity of anti-mucin 1 chimeric antigen receptor T cells expressing PD-1-CD28 switch receptor against cholangiocarcinoma cells

Background aimsCholangiocarcinoma (CCA) is a lethal bile-duct cancer that is difficult to treat by current standard procedures. This drawback has prompted us to develop adoptive T-cell therapy for CCA, which requires an appropriate target antigen for binding of chimeric antigen receptor (CAR) T cells. Mucin 1 (MUC1), an overexpressed protein in CCA cells, is a potential target antigen for the CAR T-cell development. However, MUC1 overexpression also is associated with the upregulation of programmed death-ligand 1 (PD-L1), an immune checkpoint protein that prohibits anti-tumor functions of T cells, probably causing poor overall survival of patients with CCA.MethodsTo overcome this problem, we developed anti-MUC1-CAR T cells containing PD-1-CD28 switch receptor (SR), namely αM.CAR/SR T cells, to target MUC1 and switch on the inhibitory signal of PD-1/PD-L1 interaction to activate CD28 signaling. Our lentiviral construct contains the sequences that encode anti-MUC1-single chain variable fragment, CD137 and CD3ζ, linked with P2A, PD-1 and CD28.ResultsInitially, the upregulations of MUC1 and PD-L1 proteins were confirmed in CCA cell lines. αM.CAR and SR were co-expressed in 53.53 ± 13.89% of transduced T cells, mainly CD8⁺ T cells (85.7 ± 0.75%, P<0.0001) with the effector memory phenotype (59.22 ± 16.31%, P < 0.01). αM.CAR/SR T cells produced high levels of intracellular tumor necrosis factor-α and interferon-γ in response to the activation by CCA cells expressing MUC1, including KKU-055 (27.18 ± 4.38% and 27.33 ± 5.55%, respectively, P < 0.05) and KKU-213A (47.37 ± 12.67% and 54.55 ± 8.66%, respectively, P < 0.01). Remarkably, the cytotoxic function of αM.CAR/SR T cells against KKU-213A cells expressing PD-L1 was significantly enhanced compared with the αM.CAR T cells (70.69 ± 14.38% versus 47.15 ± 8.413%, respectively; P = 0.0301), correlated with increased granzyme B production (60.6 ± 9.89% versus 43.2 ± 8.95%, respectively; P = 0.0402). Moreover, the significantly enhanced disruption of KKU-213A spheroids by αM.CAR/SR T cells (P = 0.0027), compared with αM.CAR T cells, was also observed.ConclusionTaken together, the cytotoxic function of αM.CAR/SR T cells was enhanced over the αM.CAR T cells, which are potential to be further tested for CCA treatment.     

QTc dispersion as a novel marker in identifying patients requiring an epicardial approach for ablation of scar mediated ventricular tachycardia

IntroductionEpicardial exit sites of ventricular tachycardia (VT) are frequently encountered during VT ablation requiring an epicardial ablation approach for successful elimination of VT. We sought to assess the utility of repolarization markers in identifying individuals requiring an epicardial ablation approach in addition to an endocardial approach.Methods32 patients who underwent successful ablation for scar mediated VT were included in the study. Fourteen patients who required a combined endocardial and epicardial VT ablation were defined as epicardial VT group (Epi) whereas 18 patients who were successfully ablated from the endocardium alone constituted the endocardial VT group (Endo). Repolarization markers during sinus rhythm were compared between the two groups.ResultsA higher QTc max and QTc dispersion were seen in the Epi group compared to Endo group (479 ± 34 vs 449 ± 20, p = 0.008 and 63 ± 13 vs 38 ± 8, p = 0.001, respectively). Ts-p and Ts-p/Tp-e were higher in the Epi group (166 ± 23 vs 143 ± 23, p = 0.008 and 1.55 ± 0.26 vs 1.3 ± 0.21, p < 0.005). On multivariate regression, QTc dispersion was an independent predictor of the need for an epicardial approach to ablation. A QTc dispersion more than 51.5 msec identified individuals requiring a combined epicardial and endocardial approach to ablation with a sensitivity of 92.9% and a specificity of 100%.ConclusionsPatients requiring an epicardial ablation have a higher QTc dispersion. A value greater than 51.5 msec reliably differentiates between the two groups with high sensitivity and specificity.     

The in vivo assessment of mechanical loadings on pectoral pacemaker implants

Reduced sizes of implantable cardiac pacemakers and clinical advances have led to a higher feasibility of using such devices in younger patients including children. Increased structural demands deriving from reduced device size and more active recipients require detailed knowledge of in vivo mechanical conditions to ensure device reliability. Objective of this study was the proof of feasibility of a system for the measurement of in vivo mechanical loadings on pacemaker implants. The system comprised the following: implantable instrumented pacemaker (IPM) with six force sensors, accelerometer and radio-frequency (RF) transceiver; RF data logging system and video capture system. Three Chacma baboons (20.6±1.15 kg) received one pectoral sub-muscular IPM implant. After wound healing, forces were measured during physical activities. Forces during range of motion of the arm were assessed on the anaesthetized animals prior to device explantation. Mass, volume and dimensions of the excised Pectoralis major muscles were determined after device explantation. Remote IPM activation and data acquisition were reliable in the indoor cage environment with transceiver distances of up to 3 m. Sampling rates of up to 1000 Hz proved sufficient to capture dynamic in vivo loadings. Compressive forces on the IPM in conscious animals reached a maximum of 77.2±54.6 N during physical activity and were 22.2±7.3 N at rest, compared with 34.6±15.7 N maximum during range of motion and 13.4±3.3 N at rest in anaesthetized animals. The study demonstrated the feasibility of the developed system for the assessment of in vivo mechanical loading conditions of implantable pacemakers with potential for use for other implantable therapeutic devices.     

A Meta-Analysis of P2X7 Gene-762T/C Polymorphism and Pulmonary Tuberculosis Susceptibility

AimWe performed a comprehensive meta-analysis to determine the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis susceptibility.MethodologyBased on comprehensive searches of the PubMed, SCI, Elsevier, China National Knowledge Infrastructure (CNKI) and Wanfang Database, we identified eligible studies about the association between P2X7 -762T/C polymorphism and pulmonary tuberculosis risk. Pooled odds ratio (ORs) and 95% confidence intervals (95%CIs) were calculated in random-effects model.ResultsA total of 2207 tuberculosis cases and 2220 controls in 8 case-control studies were included in this meta-analysis. Allele model (C vs. T: p = 0.15; OR = 0.83, 95% CI = 0.65–1.07), homozygous model (CC vs. TT: p = 0.23; OR = 0.73, 95% CI = 0.44 to 1.22), and heterozygous model (CT vs. TT: p = 0.57; OR = 0.92, 95% CI = 0.68 to 1.24) did not show increased risk of developing pulmonary tuberculosis. Similarly, dominant model (CC+CT vs. TT: p = 0.32; OR = 0.84, 95% CI = 0.59 to 1.19) and recessive model (CC vs. CT+TT: p = 0.08; OR = 0.77, 95% CI = 0.57 to 1.04) failed to show increased risk of developing pulmonary tuberculosis. Subgroup analysis by ethnicity did not detect any significant association between P2X7–762T/C polymorphism and pulmonary tuberculosis susceptibility.ConclusionsP2X7 -762T/C gene polymorphism is not associated with pulmonary tuberculosis susceptibility.     

Efficacy and safety of leadless pacemaker: A systematic review,pooled analysis and meta-analysis

BackgroundLeadless pacemakers have been designed as an alternative to transvenous systems which avoid some of the complications associated with transvenous devices. We aim to perform a systematic review of the literature to report the safety and efficacy findings of leadless pacemakers.MethodsWe searched MEDLINE and EMBASE to identify studies reporting the safety, efficacy and outcomes of patients implanted with a leadless pacemaker. The pooled rate of adverse events was determined and random-effects meta-analysis was performed to compare rates of adverse outcomes for leadless compared to transvenous pacemakers.ResultsA total of 18 studies were included with 2496 patients implanted with a leadless pacemaker and success rates range between 95.5 and 100%. The device or procedure related death rate was 0.3% while any complication and pericardial tamponade occurred in 3.1% and 1.4% of patients, respectively. Other complications such as pericardial effusion, device dislodgement, device revision, device malfunction, access site complications and infection occurred in less than 1% of patients. Meta-analysis of four studies suggests that there was no difference in hematoma (RR 0.67 95%CI 0.21–2.18, 3 studies), pericardial effusion (RR 0.59 95%CI 0.15–2.25, 3 studies), device dislocation (RR 0.33 95%CI 0.06–1.74, 3 studies), any complication (RR 0.44 95%CI 0.17–1.09, 4 studies) and death (RR 0.45 95%CI 0.15–1.35, 2 studies) comparing patients who received leadless and transvenous pacemakers.ConclusionLeadless pacemakers are safe and effective for patients who have an indication for single chamber ventricular pacing and the findings appear to be comparable to transvenous pacemakers.