Comparison between IV immune globulin (IVIG) and anti‐D globulin for treatment of immune thrombocytopenia: a randomized open‐label study

To compare the effect of IV immune globulin (IVIG) and anti‐D globulin (anti‐D) for treatment of immune thrombocytopenia (ITP) in children. A randomized, open‐label, single‐center clinical trial was carried out in Amir‐Kabir Hospital (Arak, Iran). The study was performed on 60 children with acute and chronic ITP, aged from 1 to 15 years. Patients were randomly assigned (1:1) to 50 μg/kg anti‐D or 1 g/kg IVIG. Platelet counting was performed at baseline and at 3, 7, and 14 days after treatment termination. Safety assessment was performed in all patients. Anti‐D caused a quicker response on the 3rd day of treatment (P < 0.001). Both drugs caused a significant rise in number of platelets on the 7th and the 14th day of treatment. Compared to IVIG, except a significant drop in hemoglobin concentration (P < 0.001), anti‐D had lower rate of side effects including fever (P < 0.05), allergy (P < 0.01), and headache (P < 0.001). Our results showed that anti‐D was associated with rapid rise of platelets compared to IVIG. In addition, anti‐D treatment had acceptable safety profile.     

HLA‐DQB1*03 genotype and perioperative blood transfusion are not conducive to the prognosis of patients with gastric cancer

Background

Gastric cancer (GC) is a disease associated with a higher incidence and mortality, and some host genetic polymorphisms have been reported as potential factors contributing to the development of GC. In view of this, the study was conducted to investigate the effects of HLA‐DQB1 gene polymorphisms and perioperative blood transfusion on prognosis of patients with gastric cancer (GC).

Methods

A total of 142 patients with GC (case group) and 150 healthy controls (control group) were enrolled. Relationship between HLA‐DQB1 gene polymorphisms, perioperative blood transfusion, and clinical pathological parameters of patients with GC after operation was analyzed. Kaplan‐Meier curve was applied for analyzing survival rate of patients with GC, and Cox multivariate regression analysis for prognostic factors of patients with GC.

Results

The frequency of HLA‐DQB1*03 gene was increased in patients with GC. Patients with GC with HLA‐DQB1*03 genotype had higher number of tumor size >6 cm, deeper depth of infiltration, higher LNM rate, and later stage of disease. Patients with HLA‐DQB1*03 genotype had lower survival rate compared with other genotypes. Anemia before operation, depth of infiltration in T3 stage and T4 stage, LNM in N1 stage and N2 stage, and HLA‐DQB1*03 genotype were regarded as independent risk factors for patients with GC.

Conclusion

These results demonstrate that HLA‐DQB1*03 genotype and perioperative blood transfusion are not conducive to the prognosis of patients with GC, which could provide a reference for the treatment of GC.

     

Mineralization of three‐dimensional osteoblast cultures is enhanced by the interaction of 1α,25‐dihydroxyvitamin D3 and BMP2 via two specific vitamin D receptors

1α,25‐Dihydroxyvitamin D3 [1α,25(OH)2D3] and bone morphogenetic protein‐2 (BMP2) are both used to stimulate osteoblastic differentiation. 1α,25(OH)2D3 regulates osteoblasts through classical steroid hormone receptor mechanisms and through rapid responses that are mediated by two receptors, the traditional vitamin D receptor (VDR) and protein disulphide isomerase family A member 3 (Pdia3). The interaction between 1α,25(OH)2D3 and BMP2, especially in three‐dimensional (3D) culture, and the roles of the two vitamin D receptors in this interaction are not well understood. We treated wild‐type (WT), Pdia3‐silenced (Sh‐Pdia3) and VDR‐silenced (Sh‐VDR) pre‐osteoblastic MC3T3‐E1 cells with either 1α,25(OH)2D3, or BMP2, or with 1α,25(OH)2D3 and BMP2 together, and measured osteoblast marker expression in 2D culture and mineralization in a 3D poly(ε‐caprolactone)–collagen scaffold model. Quantitative PCR showed that silencing Pdia3 or VDR had a differential effect on baseline expression of osteoblast markers. 1α,25(OH)2D3 + BMP2 caused a synergistic increase in osteoblast marker expression in WT cells, while silencing either Pdia3 or VDR attenuated this effect. 1α,25(OH)2D3 + BMP2 also caused a synergistic increase in Dlx5 in both silenced cell lines. Micro‐computed tomography (μCT) showed that the mineralized volume of untreated Sh‐Pdia3 and Sh‐VDR 3D cultures was greater than that of WT. 1α,25(OH)2D3 reduced mineral in WT and Sh‐VDR cultures; BMP2 increased mineralization; and 1α,25(OH)2D3 + BMP2 caused a synergistic increase, but only in WT cultures. SEM showed that mineralized matrix morphology in 3D cultures differed for silenced cells compared to WT cells. These data indicate a synergistic crosstalk between 1α,25(OH)2D3 and BMP2 toward osteogenesis and mineral deposition, involving both VDR and Pdia3. Copyright © 2013 John Wiley & Sons, Ltd.     

CYP2C19 and ABCB1 genetic polymorphisms correlate with the recurrence of ischemic cardiovascular adverse events after clopidogrel treatment

Background

This study was aimed to investigate the correlation between CYP2C19 and ABCB1 polymorphisms and the recurrence of ischemic cardiovascular adverse events in patients with coronary artery disease treated with clopidogrel.

Methods

A total of 168 patients with coronary heart disease who underwent PCI operation and received clopidogrel treatment were enrolled. Dual antiplatelet therapy was applied to the treatment of patients for 2 years. Thromboelastography was used to test the efficiency of blood coagulation. Polymerase chain reaction (PCR) was used to detect CYP2C19 and ABCB1 3435CT polymorphisms. One‐year follow‐up visit was carried out to record the incidence of cardiovascular adverse events after drug‐eluting stent implantation was inset.

Results

Follow‐up visit results suggested that the patients with high on‐treatment platelet reactivity (HPR) had a higher recurrence rate of cardiovascular adverse events after PCI operation and clopidogrel treatment. Gene polymorphism testing results indicated that patients with CYP2C19*3 had a significantly higher incidence of HPR, whereas CYP2C19*2 and ABCB1 3435CT were not significantly correlated with HPR. Multivariable logistic regression analysis showed that CYP2C19*3 might be an independent predictive factor of post‐PCI HPR. In addition, CYP2C19*3 as well as post‐PCI HPR could function as independent predictive factors of cardiovascular adverse events.

Conclusion

CYP2C19*3 polymorphism could be an important predictive factor of HPR and ischemic cardiovascular adverse events after clopidogrel treatment.

     

The genetic influences on oxycodone response characteristics in human experimental pain

Human experimental pain studies are of value to study basic pain mechanisms under controlled conditions. The aim of this study was to investigate whether genetic variation across selected mu‐, kappa‐ and delta‐opioid receptor genes (OPRM1, OPRK1and OPRD1, respectively) influenced analgesic response to oxycodone in healthy volunteers. Experimental multimodal, multitissue pain data from previously published studies carried out in Caucasian volunteers were used. Data on thermal skin pain tolerance threshold (PTT) (n = 37), muscle pressure PTT (n = 31), mechanical visceral PTT (n = 43) and thermal visceral PTT (n = 41) were included. Genetic associations with pain outcomes were explored. Nineteen opioid receptor genetic polymorphisms were included in this study. Variability in oxycodone response to skin heat was associated with OPRM1 single‐nucleotide polymorphisms (SNPs) rs589046 (P < 0.0001) and rs563649 (P < 0.0001). Variability in oxycodone response to visceral pressure was associated with four OPRM1 SNPs: rs589046 (P = 0.015), rs1799971 (P = 0.045), rs9479757 (P = 0.009) and rs533586 (P = 0.046). OPRM1 SNPs were not associated with oxycodone visceral heat threshold, however, one OPRD1 rs419335 reached significance (P = 0.015). Another OPRD1 SNP rs2234918 (P = 0.041) was associated with muscle pressure. There were no associations with OPRK1 SNPs and oxycodone response for any of the pain modalities. Associations were found between analgesic effects of oxycodone and OPRM1 and OPRD1 SNPs; therefore, variation in opioid receptor genes may partly explain responder characteristics to oxycodone.     

Neonatal acute megakaryoblastic leukemia mimicking congenital neuroblastoma

We describe a neonate with abdominal distension, massive hepatomegaly, and high serum neuron‐specific enolase level suggestive of congenital neuroblastoma. The patient died of pulmonary hemorrhage after therapy. Autopsy revealed that the tumor cells in the liver indicated acute megakaryocytic leukemia with the RBM15‐MKL1 fusion gene.     

Sumatriptan reduces severity of status epilepticus induced by lithium–pilocarpine through nitrergic transmission and 5‐HT1B/D receptors in rats: A pharmacological‐based evidence

Status epilepticus (SE) is a life‐threatening neurologic disorder that can be as both cause and consequence of neuroinflammation. In addition to previous reports on anti‐inflammatory property of the anti‐migraine medication sumatriptan, we have recently shown its anticonvulsive effects on pentylenetetrazole‐induced seizure in mice. In the present study, we investigated further (i) the effects of sumatriptan in the lithium–pilocarpine SE model in rats, and (ii) the possible involvement of nitric oxide (NO), 5‐hydroxytryptamin 1B/1D (5‐HT_1B/1D) receptor, and inflammatory pathways in such effects of sumatriptan. Status epilepticus was induced by lithium chloride (127 mg/kg, i.p) and pilocarpine (60 mg/kg, i.p.) in Wistar rats. While SE induction increased SE scores and mortality rate, sumatriptan (0.001‐1 mg/kg, i.p.) improved it (P < 0.001). Administration of the selective 5‐HT_1B/1D antagonist GR‐127935 (0.01 mg/kg, i.p.) reversed the anticonvulsive effects of sumatriptan (0.01 mg/kg, i.p.). Although both tumor necrosis factor‐α (TNF‐α) and NO levels were markedly elevated in the rats' brain tissues post‐SE induction, pre‐treatment with sumatriptan significantly reduced both TNF‐α (P < 0.05) and NO (P < 0.001) levels. Combined GR‐127935 and sumatriptan treatment inhibited these anti‐inflammatory effects of sumatriptan, whereas combined non‐specific NOS (L‐NAME) or selective neuronal NOS (7‐nitroindazole) inhibitors and sumatriptan further reduced NO levels. In conclusion, sumatriptan exerted a protective effect against the clinical manifestations and mortality rate of SE in rats which is possibly through targeting 5‐HT_1B/1D receptors, neuroinflammation, and nitrergic transmission.     

Silencing of the DNA methyltransferase 1 associated protein 1 (DMAP1) gene in the invasive ladybird Harmonia axyridis implies a role of the DNA methyltransferase 1‐DMAP1 complex in female fecundity

The invasive harlequin ladybird Harmonia axyridis is a textbook example of polymorphism and polyphenism as the temperature during egg development determines the frequency of melanic morphs and the number and size of black spots in nonmelanic morphs. Recent concepts in evolutionary biology suggest that epigenetic mechanisms can translate environmental stimuli into heritable phenotypic changes. To investigate whether epigenetic mechanisms influence the penetrance and expressivity of colour morphs in H. axyridis, we used RNA interference to silence key enzymes required for DNA methylation and histone modification. We found that neither of these epigenetic mechanisms affected the frequency of different morphs, but there was a significant impact on life‐history traits such as longevity and fecundity. Strikingly, we found that silencing the gene encoding for DNA methyltransferase 1 associated protein 1 (DMAP1) severely reduced female fecundity, which correlated with an abundance of degenerated ovaries in DMAP1‐knockdown female beetles. Finally, we observed significant differences in DMAP1 expression when we compared native and invasive H. axyridis populations with a biocontrol strain differing in egg‐laying capacity, suggesting that the DNA methyltransferase 1‐DMAP1 complex may influence the invasive performance of this ladybird.     

Multiple functions of miR‐8‐3p in the development and metamorphosis of the red flour beetle,Tribolium castaneum

The microRNA miR‐8‐3p is conserved among insects and closely involved in development and immunity, but its functions in vivo are unexplored in the red flour beetle, Tribolium castaneum. Here, we show that miR‐8‐3p was highly expressed in late larva and early adult stages, as determined by quantitative real‐time PCR. It was enriched in the fat body and cuticle in late larval tissues and abundant in the head and cuticle in early adult tissues, indicating this microRNA plays important roles during T. castaneum development. Specific inhibition of miR‐8‐3p in late larvae led to metamorphosis defects in the development of wings, eyes, legs and embryo. Moreover, a series of genes related to organism development were identified as miR‐8‐3p targets by computational prediction and microRNA–messenger RNA interaction validation, including Wingless, Eyg, Fpps and Sema‐1a. These genes were critical for the regulation of the larva‐to‐adult transition. Eyg, as a functional target of miR‐8‐3p, participates in eye development, which was further confirmed by luciferase assay and loss‐of‐function analyses. In brief, miR‐8‐3p is broadly involved in the development of wings, eyes and legs through its target genes and has extensive regulatory roles during T. castaneum development.     

A case‐control study and meta‐analysis reveal the association between COX‐2 G‐765C polymorphism and primary end‐stage hip and knee osteoarthritis

Background

Osteoarthritis (OA) is a popular arthrosis featured as pain, limited joint activity, and deformity. Cyclooxygenase‐2 (COX‐2) has been reported to be up‐regulated in arthritic tissues and is integral to the progression of osteoarthritis (OA). Previous studies showed the COX‐2 promoter G‐765C polymorphism could influence COX‐2 expression. However, the relationship between the variant and OA risk is contrasting.

Methods

We conducted a case‐control study with 196 primary end‐stage hip and knee OA cases and 196 controls in a Chinese Han population. Subsequently, we integrated this case‐control study in a meta‐analysis to acquire greater statistical power. The results from our case‐control study using MassARRAY genotyping technology and binary logistic regression statistical methods.

Results

The variant carriers in the Chinese Han population had a lower primary end‐stage hip and knee OA susceptibility (C vs G: OR = 0.350, 95%CI: 0.154‐0.797, P = .012; GC vs GG: adjusted OR = 0.282, 95%CI: 0.118‐0.676, P = .005). Stratification studies indicated that a higher GC frequency in women decreased not only knee OA susceptibility but also unilateral knee OA risk. The meta‐analysis showed that the variant exhibited a significantly decreased OA risk through comparisons involving allelic, homozygous, heterozygous, and dominant models.

Conclusion

Our findings suggest that the COX‐2 G‐765C polymorphism exerts a protective effect against primary end‐stage knee osteoarthritis in a female Chinese Han population.

     

MicroRNA miR‐252 targets mbt to control the developmental growth of Drosophila

Developmental growth is an intricate process involving the coordinated regulation of the expression of various genes, and microRNAs (miRNAs) play crucial roles in diverse processes throughout animal development. The ecdysone‐responsive miRNA, miR‐252, is normally upregulated during the pupal and adult stages of Drosophila development. Here, we found that overexpression of miR‐252 in the larval fat body decreased total tissue mass through a reduction in both cell size and cell number, causing a concomitant decrease in larval size. Furthermore, miR‐252 overexpression led to a delayed larval‐to‐pupal transition with defective anterior spiracle eversion, as well as a decrease in adult size and mass. Conversely, adult flies lacking miR‐252 showed an increase in mass compared with control flies. We found that miR‐252 directly targeted mbt, encoding a p21‐activated kinase, to repress its expression. Notably, co‐overexpression of mbt rescued the developmental and growth defects associated with miR‐252 overexpression, indicating that mbt is a biologically relevant target of miR‐252. Overall, our data support a role for the ecdysone/miR‐252/mbt regulatory axis in growth control during Drosophila development.     

QT length during methadone maintenance treatment: gene × dose interaction

Methadone is known to be a risk factor for sudden death by enlarging ECG QT corrected (QTc) interval. For other medical conditions, QTc lengthening has been described as the result of interactions between pharmacological treatments and genetic factors. Former heroin‐dependent subjects under methadone maintenance treatment in remission for at last 3 months were recruited. We studied the association between QTc length (Bazett formula) and 126 SNPs located on five genes (KCNE1, KCNQ1, KCNH2, NOS1AP and SCN5A) previously associated with drug‐induced QT prolongation. Both SNP‐based and gene‐based approaches were used, and we tested also the interaction of the top SNP with methadone dosage to predict the QTc length. In our sample of 154 patients, current methadone daily dose was associated with QTc length (r_Pearson = 0.26; P = 10^?3). Only one SNP, rs11911509 on KCNE1, remained significantly associated with QT length after correction for multiple testing (P = 3.84 × 10^?4; p_corrected = 0.049). Using a gene‐based approach, KCNE1 was also significantly associated with QTc length (p_empirical = 0.02). We found a significant interaction between methadone dosage and rs11911509 minor allele count (allele A vs. C; P = 0.01). Stratified analysis revealed that the correlation between QTc length and methadone dosage was restricted only to AA carriers of this top SNP. Patients’ genetic background should be taken into account in the case of clinically relevant QT enlargement during methadone maintenance treatment.     

Bispecific targeting of thrombin activatable fibrinolysis inhibitor and plasminogen activator inhibitor‐1 by a heterodimer diabody

Summary. Background and objectives: Thrombin activatable fibrinolysis inhibitor (TAFI) and plasminogen activator inhibitor‐1 (PAI‐1) play important roles in fibrinolysis. Both reduce plasmin generation, but they exert their antifibrinolytic effects via different mechanisms. This study reports the cloning and characterization of a heterodimer diabody that inhibits TAFI and PAI‐1 simultaneously. Methods and results: The diabody was derived from two inhibiting monoclonal antibodies, i.e. MA‐33H1F7, an anti‐PAI‐1 antibody that induces non‐inhibitory substrate behavior of PAI‐1, and MA‐T12D11, an anti‐TAFI antibody that inhibits activation of TAFI by the thrombin–thrombomodulin complex. A single‐chain variable fragment (scFv) was derived from MA‐T12D11 that displayed slightly reduced binding and inhibitory properties as compared to MA‐T12D11. Characterization of the diabody revealed a similar affinity for TAFI and PAI‐1 as that of the parental antibodies. Furthermore, the inhibitory properties of MA‐33H1F7 and MA‐T12D11 were fully preserved in the diabody format. In platelet‐free plasma (PFP) clots, addition of the diabody had a stronger effect in shortening lysis times than either MA‐T12D11 or MA‐33H1F7. A similar reduction in clot lysis time was observed in platelet‐rich plasma (PRP) clots. The same effect on clot lysis times in PFP and PRP was also achieved by the combined addition of MA‐T12D11 and MA‐33H1F7. The lysis rate of human model thrombi, made from whole blood, was approximately doubled after addition of the diabody. Moreover, this effect was significantly better than after the combined addition of the individual antibodies. Conclusions: These observations demonstrate that simultaneous inhibition of TAFI and PAI‐1 results in faster lysis of the formed thrombus.     

CYP2E1, GSTM1 and GSTT1 genetic polymorphisms and susceptibility to antituberculosis drug-induced hepatotoxicity: a nested case-control study

What is Known and Objective: The pathogenic mechanism of antituberculosis drug‐induced hepatotoxicity (ATDH) is thought to involve drug‐metabolizing enzymes including N‐acetyl transferase2 (NAT2), cytochrome P4502E1 (CYP2E1) and glutathione S‐transferase (GST) M1, T1. The associations between genetic polymorphisms of those genes and ATDH have been reported but with inconsistent results. Moreover, most studies were hospital‐based retrospective studies and not prospective. We aimed to investigate possible associations of CYP2E1, GSTM1 and GSTT1 genetic polymorphisms with ATDH using a more robust case–control study nested in a population‐based prospective antituberculosis treatment cohort. Methods: A total of 4304 patients with smear‐positive tuberculosis (TB) who received standard short‐course chemotherapy were monitored for 6–9 months. Incidence density sampling method was adopted to select controls and 4 : 1 matched with each ATDH cases by age (±5 years), sex, treatment history, disease severity and drug dosage. The CYP2E1, GSTM1 and GSTT1 polymorphisms were genotyped using PCR–RFLP and multiplex PCR methods. Conditional logistic regression model was used to calculate odds ratio (OR) and 95% confidence interval (CI), as well as corresponding P‐values. Results and Discussion: A total of 89 ATDH cases and 356 controls were included in this study. There was no statistically significant association between CYP2E1 RsaI c1/c1 genotype or DraI C/C genotype and ATDH (OR = 0·99, 95% CI:0·62–1·59; OR = 1·13, 95% CI: 0·40–3·20, respectively) compared with CYP2E1 RsaI c1/c2 or c2/c2 genotypes or DraI D/D genotype, or between GSTM1/GSTT1 null genotypes and ATDH (OR = 1·22, 95% CI: 0·76–1·96; OR = 0·96, 95% CI: 0·60–1·52, respectively) compared with non‐null genotypes. What is new and Conclusion: This is the first study of the involvement of CYP2E1, GSTM1 and GSTT1 genetic polymorphisms in ATDH using a nested case–control population‐based prospective cohort design. We could not confirm positive associations of genetic polymorphisms of CYP2E1 RsaI, CYP2E1 DraI, GSTM1 null and GSTT1 null with ATDH reported by various groups, in our Chinese TB population.     

The correlation between SNPs within the gene of adrenergic receptor and neuropeptide Y and risk of cervical vertigo

Background

The current investigation was aimed to explore the potential associations of SNPs within ADRB2, ADRB1, NPY, and ADRA1A with risk and prognosis of cervical vertigo.

Methods

Altogether 216 patients with cervical vertigo and 204 healthy controls were gathered, and their DNAs were extracted utilizing the whole‐blood DNA extraction kit. Besides, the PCR reactions were conducted using the TaqMan^R single nucleotide polymorphism (SNP) genotyping assays, and the SNPs were detected on the 7900HT real‐time fluorogenic quantitative polymerase chain reaction (PCR) instrument. Finally, the severity of cervical vertigo was classified according to the JOA scoring, and the recovery rate (RR) of cervical vertigo was calculated in light of the formula as:

Results

The SNPs within ADRA1A [rs1048101 (T>C) and rs3802241 (C>T)], NPY [rs16476 (A>C), rs16148 (T>C), and rs5574 (C>T)], ADRB1 [rs28365031 (A>G)] and ADRB2 [rs2053044 (A>G)] were all significantly associated with regulated risk of cervical vertigo (all P < .05). Haplotypes of ADRA1A [CT and TC] and NPY [CCT and ATT] were also suggested as the susceptible factors of cervical vertigo in comparison with other haplotypes. Furthermore, the SNPs within ADRA1A [rs1048101 (T>C)], NPY [rs16476 (A>C), rs16148 (T>C)], as well as ADRB1 [rs28365031 (A>G)] all appeared to predict the prognosis of cervical vertigo in a relatively accurate way (all P < .05). Ultimately, the haplotypes of ADRA1A (CC) and NPY (CCT) tended to decrease the RR.

Conclusions

The SNPs within ADRB2, ADRB1, NPY, and ADRA1A might act as the diagnostic biomarkers and treatment targets for cervical vertigo.

     

Effect of chemical immobilization of SDF‐1α into muscle‐derived scaffolds on angiogenesis and muscle progenitor recruitment

The availability of three‐dimensional bioactive scaffolds with enhanced angiogenic capacity that have the capability to recruit tissue specific resident progenitors is of great importance for the regeneration of impaired skeletal muscle. Here, we have investigated whether introduction of chemoattractant factors to tissue specific extracellular matrix promotes cellular behaviour in vitro as well as muscle progenitor recruitment and vascularization in vivo. We developed an interconnective macroporous sponge from decellularized skeletal muscle with maintained biochemical traits of the intact muscle. SDF‐1α, a potent cell homing factor involved in muscle repair, was physically adsorbed or chemically immobilized in these muscle‐derived sponges. The immobilized sponges showed significantly higher SDF‐1α conjugation efficiency along with improved metabolism and infiltration of muscle‐derived stem cells in vitro, and thus generated uniform cellular constructs. In vivo, femoral muscle implantation in rats revealed a negligible immune response in all scaffold groups. We observed enhanced engraftment, neovascularization, and infiltration of CXCR4⁺ cells in the immobilized‐SDF‐1α sponge compared with nonimmobilized controls. Although Pax7⁺ cells identified adjacent to the immobilized‐SDF‐1α implantation site, other factors appear to be necessary for efficient penetration of Pax7⁺ cells into the sponge. These findings suggest that immobilization of cell homing factors via chemical mediators can result in recruitment of cells to the microenvironment with subsequent improvement in angiogenesis.     

Single Transseptal Big Cryoballoon Pulmonary Vein Isolation using an Inner Lumen Mapping Catheter

Background: The single big cryoballon technique for pulmonary vein isolation (PVI) has been limited by the need for two transseptal punctures (TP). We therefore investigated feasibility and safety of a simplified approach using a single TP and a novel circumferential mapping catheter (CMC). Methods: Patients underwent 28‐mm cryoballoon PVI using a single TP. The CMC (Achieve^© Medtronic Inc., Minneapolis, MN, USA) served as (1) guidewire and (2) as a PV mapping tool. Primary endpoint was PVI without switching to a regular guidewire. Secondary endpoints included: (1) PV signal quality during freezing, (2) time to PVI, (3) classification of successful ablation technique, (4) complications, and (5) procedural data. Results: A total of 32 patients (126 PVs) were studied (mean age: 62 ± 11 years, 24 males, left atrium: 40 ± 4 mm). The primary endpoint was achieved in 29/32 patients (91%) and 123/126 PVs (98%) with a procedure and fluoroscopy time of 126 ± 26 minutes and 18.9 ± 7.5 minutes, respectively. Real‐time visualization of PVI could be observed in 61/126 (48%) PVs. Time to sustained PVI versus nonsustained PVI was 66 ± 56 seconds versus 129 ± 76 seconds (P < 0.001). One phrenic nerve palsy was observed. After a follow‐up of 250 ± 84 days 23/32 patients (72%) remained in sinus rhythm. Conclusion: The “simplified single big cryoballoon” PVI strategy appears to be safe and feasible. However, real‐time PV recording was achieved in <50% of PVs. Therefore, further catheter refinements are warranted. (PACE 2012; 35:1304–1311)     

In vivo inhibition of antiphospholipid antibody‐induced pathogenicity utilizing the antigenic target peptide domain I of β2‐glycoprotein I: proof of concept

Summary. Objectives: In the antiphospholipid syndrome (APS), the immunodominant epitope for the majority of circulating pathogenic antiphospholipid antibodies (aPLs) is the N‐terminal domain I (DI) of β₂‐glycoprotein I. We have previously shown that recombinant DI inhibits the binding of aPLs in fluid phase to immobilized native antigen, and that this inhibition is greater with the DI(D8S/D9G) mutant and absent with the DI(R39S) mutant. Hence, we hypothesized that DI and DI(D8S/D9G) would inhibit aPL‐induced pathogenicity in vivo. Methods: C57BL/6 mice (n = 5, each group) were injected with purified IgG derived from APS patients (IgG‐APS, 500 μg) or IgG from normal healthy serum (IgG‐NHS) and either recombinant DI, DI(R39S), DI(D8S/D9G), or an irrelevant control peptide (at 10–40 μg). Outcome variables measured were femoral vein thrombus dynamics in treated and control groups following standardized vessel injury, expression of vascular cell adhesion molecule‐1 (VCAM‐1) on the aortic endothelial surface, and tissue factor (TF) activity in murine macrophages. Results: IgG‐APS significantly increased thrombus size as compared with IgG‐NHS. The IgG‐APS thrombus enhancement effect was abolished in mice pretreated with recombinant DI (P ≤ 0.0001) and DI(D8S/D9G) (P ≤ 0.0001), but not in those treated with DI(R39S) or control peptide. This inhibitory effect by DI was dose‐dependent, and at lower doses DI(D8S/D9G) was a more potent inhibitor of thrombosis than wild‐type DI (P ≤ 0.01). DI also inhibited IgG‐APS induction of VCAM‐1 on the aortic endothelial surface and TF production by murine macrophages. Conclusion: Our findings in this proof‐of‐concept study support the development of recombinant DI or the novel variant DI(D8S/D9G) as a potential future therapeutic agent for APS.