Catheter ablation vs. amiodarone plus losartan for prevention of atrial fibrillation recurrence in patients with paroxysmal atrial fibrillation

BACKGROUND

Although amiodarone plus angiotensin II receptor blockers (ARBs) and catheter ablation may improve sinus rhythm maintenance of paroxysmal atrial fibrillation (AF), their clinical efficacies have not been compared. This prospective cohort study was designed to compare clinical efficacy of catheter ablation and amiodarone plus losartan on sinus rhythm maintenance in patients with paroxysmal AF.

MATERIALS AND METHODS

A total of 240 patients with paroxysmal AF were assigned to four groups. CPVA group (n = 60) was treated with circumferential pulmonary vein ablation (CPVA), SPVI group (n = 60) with segmental pulmonary vein isolation, AMIO group (n = 60) with amiodarone and AMIO + LO group (n = 60) with amiodarone plus losartan. The endpoint was documented recurrence of AF > 30 s by Holter or conventional 12-lead ECG in the 1-year follow-up period.

RESULTS

During 12 months of follow-up, the primary end point was reached in 28 patients in CPVA group, 14 patients in SPVI group, 25 patients in AMIO group and 13 patients in AMIO + LO group, respectively. The sinus rhythm in SPVI and AMIO + LO group were significant higher than that in CPVA and AMIO group (P < 0.01 and 0.025), and no difference between CPVA and AMIO group. The maintenance rate of sinus rhythm in SPVI group was similar to that in AMIO + LO group.

CONCLUSIONS

This study demonstrates that segmental pulmonary vein isolation in preventing AF recurrence is similar to amiodarone plus losartan, but it is superior to CPVA and amiodarone alone in patients with paroxysmal AF. Larger multicentre studies are needed to confirm its long-term outcomes.

Experimental animal models of bullous pemphigoid

Bullous pemphigoid (BP) is a cutaneous autoimmune blistering disease characterized immunohistologically by dermal-epidermal junction separation, an inflammatory cell infiltrate in the upper dermis, and autoantibodies directed against the hemidesmosomal proteins BP230 and BP180. A passive transfer mouse model of BP that uses rabbit antibodies targeted against murine BP180 reproduces the key clinical and histological features of human BP. Using this model, it has been demonstrated that subepidermal blistering is initiated by anti-BP180 antibodies and mediated by complement activation, mast cell degranulation, neutrophil infiltration, and proteinase secretion. The rabbit-anti mouse IgG passive transfer model is not compatible with study of human pathogenic antibodies, as the human and murine antigenic epitopes are not cross-reactive. Two humanized mouse models in which the murine form of BP180 is replaced the human homologue have recently emerged. Autoantibodies isolated from human patients induce experimental BP in the humanized mice, and disease progression mirrors that observed in the rabbit-anti mouse IgG model. The humanized mouse models present ideal in vivo systems to test novel therapeutic strategies for disease management. In this review, we discuss the progress made in understanding the pathogenesis of BP, as well as the limits of using animal models to investigate human disease.

Tenuifolin, an extract derived from tenuigenin, inhibits amyloid-beta secretion in vitro

AIM

Previous studies have shown that tenuigenin, a crude extract of Polygala tenuifolia Willd. that is commonly used in traditional Chinese herbal medicine for memory loss, can reduce the secretion of Abeta from cultured cells. However, the mechanism underlying this effect and the active compound derived from tenuigenin is unknown. In this study, a purified component of tenuigenin, tenuifolin, was examined and revealed to be an effective compound in vitro.

METHODS

Abeta secretion from three sets of COS-7 cells, each carrying a plasmid expressing a different form of APP was examined following the treatment with tenuifolin. Initially, tenuifolin was determined to have no inherent toxicity to either the transfected or wild type cells at the effective concentrations. Cells were then treated with 0.5-2.0 microg mL(-1) tenuifolin for 12 h and their media were examined via an ELISA for Abeta1-40 and Abeta-42.

RESULTS

We found that treatment with 2.0 microg mL(-1) tenuifolin significantly decreased Abeta secretion from COS-7 cells without altering the ratio of Abeta1-40 and Abeta-42. This effect is most probably due to inhibition of the beta-site APP cleaving enzyme as Abeta secretion was not inhibited from cells expressing the C99 fragment.

CONCLUSION

Tenuifolin is an effective compound from tenuigenin. We believe that this finding should lead the way for future experiments to determine the exact mechanism for tenuifolin's effect on Abeta secretion.

Stromal cell-derived factor-1 promotes survival of pancreatic beta cells by the stabilisation of beta-catenin and activation of transcription factor 7-like 2 (TCF7L2)

AIMS/HYPOTHESIS

Stromal cell-derived factor-1 (SDF-1) is a chemokine produced in stromal tissues in multiple organs. Earlier we reported on levels of SDF-1 and SDF-1 receptor (CXCR4) in the insulin-producing beta cells of the mouse pancreas and determined that the SDF-1/CXCR4 axis is important for beta cell survival through activation of the prosurvival kinase, protein kinase B (AKT). Since AKT is known to modulate the wingless-type MMTV integration site family (WNT) signalling cascade, we examined the effects of SDF-1/CXCR4 on WNT signalling in beta cells and whether this signalling is important for cell survival.

METHODS

Activation of downstream WNT signalling (beta-catenin and transcription factor 7-like 2, [TCF7L2]) in response to SDF-1 was examined in the islets of WNT signalling reporter (Tcf-optimal promoter beta-galactosidase) mice and in INS-1 and MIN6 beta cells. Cytoprotection of beta cells by SDF-1 in response to the induction of apoptosis was assessed by caspase 3 and TUNEL assays.

RESULTS

SDF-1 induced WNT signalling in beta cells of isolated islets and in INS-1 cells via CXCR4-mediated activation of Galphai/o-coupled signalling and the phosphatidylinositol 3-kinase/AKT signalling cascade resulting in the inhibition of glycogen synthase kinase 3-beta. The key WNT signalling regulators, beta-catenin and AKT, were activated by SDF-1 at the transcriptional and post-translational levels. Specific inhibition of beta-catenin in the WNT signalling cascade reversed the anti-apoptotic effects of SDF-1.

CONCLUSIONS/INTERPRETATION

SDF-1 promotes pancreatic beta cell survival via activation of AKT and downstream WNT signalling via the stabilisation and activation of beta-catenin/TCF7L2 transcriptional activators. These findings suggest a mechanism for SDF-1 based glucose-lowering therapies by enhancing beta cell mass through increasing cell survival.

Transient simulation of last deglaciation with a new mechanism for Bolling-Allerod warming

We conducted the first synchronously coupled atmosphere-ocean general circulation model simulation from the Last Glacial Maximum to the Bølling-Allerød (BA) warming. Our model reproduces several major features of the deglacial climate evolution, suggesting a good agreement in climate sensitivity between the model and observations. In particular, our model simulates the abrupt BA warming as a transient response of the Atlantic meridional overturning circulation (AMOC) to a sudden termination of freshwater discharge to the North Atlantic before the BA. In contrast to previous mechanisms that invoke AMOC multiple equilibrium and Southern Hemisphere climate forcing, we propose that the BA transition is caused by the superposition of climatic responses to the transient CO(2) forcing, the AMOC recovery from Heinrich Event 1, and an AMOC overshoot.

Lack of evidence for OSMR and RET gene mutations in a Chinese family with friction melanosis

BACKGROUND

Friction melanosis (FM) is a common dermatological disorder. Although cases have been reported, familial FM is rare. FM and macular amyloidosis (MA) have been hypothesized to be identical clinical conditions, and cutaneous lichen amyloidosis (CLA) is linked to mutations in the OSMR (oncostatin M receptor) or RET (receptor tyrosine kinase) genes.

AIM

To evaluate the OSMR and RET gene mutations in a Chinese family with FM. Methods. We investigated a family with FM with six affected members in four successive generations. All 17 exons of the OSMR and 19 exons of the RET genes were screened for mutation by PCR, and restriction enzyme digestion assays for RET codon 634 mutations were performed for selected members of the family.

RESULTS

Based on the pedigree characteristics, we suggest an autosomal dominant mode of inheritance in this FM family. We did not detect any mutations in the OSMR or RET genes.

CONCLUSIONS

We report a rare case of familial FM. Genes other than OSMR and RET may be involved in the pathogenesis of this family.

Significance of phosphatase and tensin homologue (PTEN), O(6)-methylguanine-DNA methyltransferase (MGMT), and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein expression in gynaecomastia

This study was designed to investigate the pathogenesis of gynaecomastia by measuring phosphatase and tensin homologue (PTEN), O(6)-methylguanine-DNA methyltransferase (MGMT) and DNA-dependent protein kinase catalytic subunit (DNA-PKcs) protein in breast tissue specimens from 68 patients with gynaecomastia and 24 normal male controls using immunohistochemical staining. The gynaecomastia cases were divided into three different histological types: florid, intermediate and fibrous. The PTEN, MGMT and DNA-PKcs proteins were detected in both gynaecomastia and normal breast tissue, but the levels of immunohistochemical staining of each protein were significantly lower in gynaecomastia breast tissue than in normal breast tissue. There were also significant differences in the levels of immunohistochemical staining for the three proteins according to gynaecomastia histological type. These results suggest that abnormally low levels of PTEN, MGMT and DNA-PKcs protein in gynaecomastia breast tissue may play a role in the development of gynaecomastia. Further research is required to elucidate fully their individual roles in the pathophysiology of gynaecomastia.

Sunitinib and bevacizumab for first-line treatment of metastatic renal cell carcinoma: a systematic review and indirect comparison of clinical effectiveness

Background:

Two new agents have recently been licensed for use in the treatment of metastatic renal cell carcinoma (RCC) in Europe. This paper aims to systematically review the evidence from all available randomised clinical trials of sunitinib and bevacizumab (in combination with interferon-α (IFN-α)) in the treatment of advanced metastatic RCC.

Methods:

Systematic literature searches were performed in six electronic databases. Bibliographies of included studies were searched for further relevant studies. Individual conference proceedings were searched using their online interfaces. Studies were selected according to the predefined criteria. All randomised clinical trials of sunitinib or bevacizumab in combination with IFN for treating advanced metastatic RCC in accordance with the European licensed indication were included. Study selection, data extraction, validation and quality assessment were performed by two reviewers with disagreements being settled by discussion. The effects of sunitinib and bevacizumab (in combination with IFN-α) on progression-free survival were compared indirectly using Bayesian Markov Chain Monte-Carlo (MCMC) sampling in Win BUGS, with IFN as a common comparator.

Results:

Three studies were included. Median progression-free survival was significantly prolonged with both interventions (from approximately 5 months to between 8 and 11 months) compared with IFN. Overall survival was also prolonged, compared with IFN, although the published data are not fully mature. Indirect comparison suggests that sunitinib is superior to bevacizumab plus IFN in terms of progression-free survival (hazard ratios 0.796; 95% CI 0.63–1.0; P=0.0272).

Conclusion:

There is evidence to suggest that treatment with sunitinib and treatment with bevacizumab plus IFN has clinically relevant and statistically significant advantages over treatment with IFN alone in patients with metastatic RCC.

Search for the standard model Higgs boson in tau final states

We present a search for the standard model Higgs boson using hadronically decaying tau leptons, in 1 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp collider. We select two final states: tau+/- plus missing transverse energy and b jets, and tau+ tau- plus jets. These final states are sensitive to a combination of associated W/Z boson plus Higgs boson, vector boson fusion, and gluon-gluon fusion production processes. The observed ratio of the combined limit on the Higgs production cross section at the 95% C.L. to the standard model expectation is 29 for a Higgs boson mass of 115 GeV.

Search for resonant diphoton production with the D0 detector

We present a search for a narrow resonance in the inclusive diphoton final state using approximately 2.7 fb(-1) of data collected with the D0 detector at the Fermilab Tevatron pp Collider. We observe good agreement between the data and the background prediction, and set the first 95% C.L. upper limits on the production cross section times the branching ratio for decay into a pair of photons for resonance masses between 100 and 150 GeV. This search is also interpreted in the context of several models of electroweak symmetry breaking with a Higgs boson decaying into two photons.

Measurement of the Zgamma --> nunu[over ]gamma production cross section and limits on anomalous ZZgamma and Zgammagamma couplings in pp[over] collisions at sqrt[s] = 1.96 TeV

We present the first observation of the Zgamma --> nunu[over ]gamma process at the Fermilab Tevatron at 5.1 standard deviations significance, based on 3.6 fb;{-1} of integrated luminosity collected with the D0 detector at the Fermilab Tevatron pp[over ] Collider at sqrt[s] = 1.96 TeV. The measured Zgamma production cross section multiplied by the branching fraction of Z --> nunu[over] is 32 +/- 9(stat + syst) +/-2 (lumi) fb for the photon E_{T} > 90 GeV. It is in agreement with the standard model prediction of 39 +/- 4 fb. We set limits on anomalous trilinear Zgammagamma and ZZgamma gauge boson couplings, most of which are the most restrictive to date.

Incidence, annualized cost, and utilization burden in patients with metastatic renal cell carcinoma

e17529

Background: Data on burden of metastatic renal cell carcinoma (MRCC) is scarce. The objectives of this study are to examine the incidence of MRCC and the cost and utilization burden of MRCC over time. Methods: Administrative claims data from a large, US managed care plan were used to identify commercially insured and Medicare enrollees with newly diagnosed MRCC during 01/01/03–12/31/07 and continuous enrollment 12 months prior to and at least 90 days after MRCC diagnosis. Mean (median) costs and utilization during the follow-up period were annualized. Costs were 2007 CPI-adjusted. Results: 1,427 patients were identified with newly diagnosed MRCC (average age: 62.4 years 62.6% male). The annual incidence of MRCC in the managed care plan population was 3.4, 3.8, 2.9, 3.3, and 4.4 per 100,000 enrollees in 2003 through 2007, respectively. The mean (median) annual number of ambulatory visits per patient increased among patients diagnosed in 2003 to those diagnosed in 2007, from 44.9 (33.2) to 63.7 (54.8). Mean (median) annual medical costs per patient increased by year of diagnosis from $70,797 ($33,031) in 2003 to $92,521 ($48,117) in 2007. Pharmacy costs (excluding costs for medications delivered in medical settings) increased from $5,651 ($2,004) to $13,290 ($3,609), and were approximately 7.4%-14.3% of total costs during the time period. Conclusions: This study showed an apparent slight increase in MRCC incidence rates and revealed that treatment costs and health care utilization per patient increased substantially from 2003–2007 among members of this US managed care plan. The increases in health care utilization and cost suggest the evolution in treatment options over time as more therapies become available.

No significant financial relationships to disclose.

Evaluation of aldehyde dehydrogenase 1 (ALDH1) as a marker of non-small cell lung cancer (NSCLC) stem cells (SCs) and correlation with prognosis

11105

Background: ALDH1 is a cytosolic enzyme responsible for oxidizing intracellular aldehydes, and conversion of retinol to retinoic acid in SCs. ALDH1 has been previously demonstrated to be a marker for SCs in breast cancer (Ginestier C, et al., Cell Stem Cell. 2007 Nov; 1(5):555–67). The Aldefluor assay is based on conversion of a synthetic substrate BAAA, when passively infused into cytosol, to brightly fluorescent BAA by ALDH1. Combined with fluorescence-activated cell sorting (FACS), it has been used successfully in hematopoietic and breast cancer SCs isolation. ALDH1 is also found in NSCLC. We hypothesized that ALDH1 would be a marker for NSCLC SCs and a potential prognostic marker. Methods: NSCLC SCs were isolated from human NSCLC cell lines using the Aldefluor assay and FACS. ALDH1-positive cells were analyzed extensively for SC characteristics. ALDH1 expression in 303 NSCLC biopsy specimens from three independent cohorts of NSCLC patients was then analyzed by immunohistochemisty (IHC) using an ALDH1 antibody (Santa Cruz Biotechnology) and commercially available negative controls. Results: Isolated cancer cells with high ALDH1 activity displayed cancer SCs features, including capacities for proliferation, self-renewal, differentiation; resistance to chemotherapeutic agents including cisplatin, vinorelbine, gemcitabine and docetaxel; expression of the SC surface marker CD133, and high invasiveness. ALDH1-positive cells generated tumors in vivo recapitulating heterogeneity of parental cells. Xenograft tumors derived from ALDH1-positive cells (103 each) were 36±2.9 mm3 on average in size, with some of the cells having lost ALDH1 expression. Xenograft tumors derived from ALDH1-negative cells (105 each) were 4 mm3 on average in size, without ALDH1 reactivation. Statistical analysis of quantitative IHC and clinical data showed ALDH1 expression was correlated with higher stage and grade of NSCLC (p = 0.02). Expression of ALDH1 in stage I NSCLC patients was linked to decreased 5 year cancer-specific survival (62% vs. 96%, p = 0.006) and overall survival (32% vs. 72%, p = 0.009). Conclusions: 1. ALDH1 is a NSCLC SC-associated tumor marker. 2. ALDH1 expression is a negative prognostic marker in early stage NSCLC.

No significant financial relationships to disclose.

Survival and association with time to treatment change in patients with metastatic renal cell carcinoma

e16160

Background: Metastatic renal cell carcinoma (MRCC) is associated with high mortality rates. The objectives of this study are to examine survival rates among patients using targeted therapies (Sunitinib, Sorafenib) for MRCC and the association of time to treatment change with survival. Methods: Administrative claims data from a large, US managed care plan were used to identify commercially insured and Medicare patients with newly diagnosed MRCC from 01/01/03–12/31/07 and continuous enrollment for 12 months prior to and at least 90 days after MRCC diagnosis. Survival from earliest evidence of targeted therapy (TT) was assessed through 9/16/2008. Treatment change was defined as stopping TT, switching TT or the addition of other treatments for MRCC. Results: 253 patients were identified with newly diagnosed MRCC (average age: 60.5 years; 71.5% male) who also received TT. Mean (median) survival time from initiation of therapy was 533 (507) days. A majority of those on TT (n = 205, 81.0%) experienced treatment change within 6 months after initiating the therapy; two-thirds within 30 days of therapy initiation. Unadjusted survival rates increased significantly with longer time to change in treatment (p=0.0075), with a mean survival time of 437 days for those with treatment change within 30 days and 724 days among those with treatment change 5–6 months post therapy initiation. Conclusions: Early treatment changes are associated with shorter survival times. High rates of early treatment changes indicate inadequacies in currently available targeted therapies for MRCC patients.

No significant financial relationships to disclose.