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Background: Some patients fail to respond to persistent atrial fibrillation (PeAF) catheter ablation in spite of multiple procedures and ablation strategies, including low voltage area (LVA)-guided, linear, and complex fractionated atrial electrogram (CFAE)-guided ablation procedures. We hypothesized that LVA extent could predict non-responseto Pe AF catheter ablation in spite of multiple procedures. Methods: This study included 510 patients undergoing initial ablation procedures for PeAF. LVAs were defined as regions with bipolar peak-to-peak voltages of <0.50 mV after PVI during sinus rhythm. Patients were categorized by LVA size into groups A(0-5 cm2), B (5-20 cm2), and C (over 20 cm2). The primary endpoint was AF-free survival after the last procedure. Results: During a median follow-up of 25 (17, 36) months, AF recurrence was observed in 101 (20%) patients after 1.4±0.6 ablation procedures (maximum 4). Comparison of clinical outcomes after multiple procedures in the three groups showed that the results depended on the extent of LVA. Multivariate analysis of AF-free survival after the last procedure showed that LVAs > 20 cm2 was an independent factor associated with AF recurrence after the final procedure(Hazard ratio, 7.94; 95% confidence interval, 2.91 to 21.67, P <0.001). Conclusions: Extensive LVA after initial PVI was associated with poor clinical benefit despite multiple catheter based ablations. [ABSTRACT FROM AUTHOR]

Backgrounds: The prevalence of residual left atrial low-voltageareas (LVAs) is associated with atrial fibrillation (AF) recurrence after pulmonary vein isolation. Brain natriuretic peptide (BNP) may be increased in AF patients and may raise AF recurrence risk after catheter ablation. We investigated the association between BNP and the prevalence of LVAs. Methods: One hundred and eighty three consecutive AF caseswere retrospectively enrolled that underwent initial ablation for AF (persistent AF, 82 [45%] patients). Serum BNP was measured before ablation and the natural logarithm of BNP (log-BNP) was calculated. Low-voltage points were defined as sites with left atrial electrogram amplitude <0.5 mV. LVAs were defined as regions with =5% low-voltage points across the total surface area of the left atrium. Results: Of the 183 patients, 38 (21%) had LVAs. Patients with LVAs demonstrated higher log-BNP(4.8±0.9vs. 3.9±1.2, P<0.001). The optimal cut-off value of log-BNP was 4.4, which was equivalent to 81 pg/mL of BNP. LVAs were more frequent in patients with higher log-BNP. In multivariate analysis, log-BNP>4.4 was an independent predictor of LVAs(odds ratio 2.7 [95% confidence interval 1.01-7.1], P=0.048). Freedom from AF recurrence was significantly lower in patients with than without high log-BNP (P=0.007). [ABSTRACT FROM AUTHOR]

Aims: Unmappable regular atrial tachycarrhythmias (ATs) occasionally develop during atrial fibrillation (AF) ablation, and are difficult to treat by conventional ablation. Recently, low-voltage areas (LVAs) have been reported to represent AT substrate. The purpose of this study was to elucidate the efficacy of LVA ablation for unmappable AT. Methods: This observational study included 32 consecutive patients who developed unmappable ATs during and after AF ablation. Unmappable AT was defined as AT lasting for >5 s, but that terminated or changed the activation sequence over too short a time to create a sufficient activation map. We used conventional ablation to target undetermined AT circuits estimated from activation timings of electrograms recorded on the placed electrode catheter, the response to entrainment mappings, and/or diastolic potentials during AT. Subsequently, in cases without successful elimination of unmappable ATs by conventional ablation, LVA (≤ 0.5mV) ablation was performed at the discretion of the operators. Results: Conventional ablation failed to eliminate at least one unmappable AT in 29 patients. Among them, LVA ablation was performed in 16 patients. LVA ablation eliminated all the unmappable ATs in 8 of 16patients. The LVA size did not differ between patients with and without the acute elimination of unmappable ATs (17±11 vs. 21±12 cm2, p=0.39), and AT/AF recurrence rates were comparable between the two groups (38% vs. 63%, p=0.62) during a mean follow-up period of 14±8 months. Conclusion: LVA ablation was efficacious to some extent for the elimination of unmappable ATs refractory to conventional ablation. [ABSTRACT FROM AUTHOR]

Defective appearances, including white spotting (WS), tongue defect (TD), and nipple defect (ND), in Japanese Black cattle potentially lead to economic losses to farmers in Japan. We estimated genetic parameters of defective appearances using 553,433 records of Japanese Black heifer calves housed in the Kagoshima Prefecture. Variance and covariance were estimated using the Gibbs sampling algorithm. The estimated heritability ranged from 0.29 for TD to 0.76 for WS. Percent breeding value (%BV) estimates indicated high variation in WS and ND among sires, reflecting higher heritability. Furthermore, there was a positive linear relationship between the %BV estimate of a sire and the mean incidence rate of each defect in his female offsprings. TD was positively associated with other defects. Therefore, genetic factors strongly affect the incidence of defective appearances in Japanese Black cattle. [ABSTRACT FROM AUTHOR]

Noi chicken is one of the most popular native breeds in the South of Vietnam because their good meat quality and disease resistance. Therefore, although price of their products (eggs and meat) is always high, they are always preferred. However, there have not been many studies on the morphology of this breed yet. In the current study, a total of 355 Noi chickens (164 males and 191 females) at 28 days old were selected and randomly allotted to individual cages until they reached the market weight at 84 days old. During the experiment, Noi broilers were fed ad libitum a diet with 17% crude protein and 3.000 kcal/kg ME produced by GreenFeed Vietnam Joint Stock Company. Average daily gain, feed conversion ratio and some morphological dimensions were recorded at two different stages of age (28-56 and 56-84 days old). Results were demonstrated that (i) significant differences in feed intake (P=0.006), body weight (P=0.019), beak length (P=0.014), thigh length (P=0.004), shank length (P=0.003), breast diameter (P=0.000), and thigh diameter (P=0.001) were found between males and females as well as between different stages; and (ii) body weight and some dimensions will increase rapidly at the first stage. An understanding on these economic traits helps researchers and producers have a more detailed glance on developing of each part of Noi chicken at different stages of age which they are the basic scientific foundation for further studies on this breed. [ABSTRACT FROM AUTHOR]

The aim of this study is to characterize some quantitative traits of Noi chicken, one of the Vietnamese famous native breeds for meat quality and fighting, at the stage of 0-28 days old. Therefore, 742 chicks were used to measure, record, analyze and evaluate on these traits. As results, there was significant difference in observation traits among stages of age (P=0.000). Interesting, the wings (+64.88%) and keel lengths (+58.83%) rapidly developed within the first week of life, followed by the most of other dimensions, especially breast diameter (+31.85%), thigh diameter (+71.17%) in the second week of age. An increase in the size of the measurements was due to development of the skeleton at observing time points along the experiment. However, there was strong development of muscle tissue in the second week of life as rate of the breast and thigh diameter was greatest. Noi chicks consumed amount of feed of 16.54 g/bird/day and gained a weight of 6.98 g/bird/day. Thus, their feed conversion ratio was 2.37 at the stage of 0-28 days old. Perhaps a direct positive relationship between observed traits and age were randomly established according biological characteristics of animal. This work provided initial benchmarks of Noi chicks for further studies. [ABSTRACT FROM AUTHOR]

Chicken egg white ovotransferrin (OTF) has been reported to exist in three electrophoretic variants (OTFA, OTFB and OTFC). In this report, we identified a causal polymorphism between the OTFB and OTFC variants in Japanese and Taiwanese native chickens and compared the antibacterial activity between these two variants. The cDNA sequence analyses from Satsumadori oviducts revealed that three non-synonymous SNPs T1809G (Ser52Ala), A2258G (Ile96Val) and G7823A (Asp500Asn) corresponded to the OTF electrophoretic phenotypes. Of the three SNPs, the G7823A mutation perfectly corresponded to the electrophoretic phenotypes OTFB (G/G, Asp500Asp), OTFB/C (G/A, Asp500Asn) and OTFC (A/A, Asn500Asn) in three chicken populations. The variants OTFB and OTFC exhibited similar antibacterial potency against Gram-positive and Gram-negative bacteria. This study provides, for the first time, molecular information on polymorphism of OTFB and OTFC variants of chicken ovotransferrin and its effect on the antimicrobial activity of the respective variants. [ABSTRACT FROM AUTHOR]

In the present study, we have explored the genetic relationships between red junglefowls and domestic chickens in Southeast Asia by using single nucleotide polymorphism (SNP) markers. We genotyped 475 individuals from 17 populations of red junglefowls (4 subspecies, n=39), native chickens (10 populations, n=346) and commercial breeds (3 breeds, n=90) using PCR-RFLP for the 98 autosomal SNP markers. The genotyping results showed that average heterozygosity was 0.225±0.077 for red junglefowl, 0.272±0.009 for native chickens, and 0.211±0.037 for commercial breeds of chickens. The resultant neighbor-joining (NJ) tree with three distinct clusters corresponds to red junglefowls, native chickens and commercial breeds. The subspecies of red junglefowl was clustered into one clade and more closely related to native chickens than the commercial lines. Furthermore, the results of the population structure analysis suggested that the 17 populations appear to be derived from 11 genetic populations (K=11). Among the domestic chickens, the NJ tree and genetic structure analysis revealed that Thailand native chickens was the most ancestral group of all chickens. These findings provide molecular evidence supporting the theory that the original domestication event occurred in Thailand. They also provide additional clustering information to classify red junglefowls and domestic chickens. [ABSTRACT FROM AUTHOR]

This study was aimed to evaluate the genetic diversity of Egyptian native chickens by using mtDNA sequence polymorphism. A 546-bp fragment of the mtDNA D-loop region was sequenced for a total of 36 Egyptian native chickens with 14 reference sequences from DNA databank. Of the Egyptian chickens 5 haplotypes were identified. Haplotype diversity and nucleotide diversity of the Egyptian native chickens were 0.5635±0.0845 and 0.00123± 0.00108, respectively. The Egyptian native chickens were distributed within one clade, which were closed to the haplotypes from Indian subcontinent and Southeast Asia. Most of Egyptian native chickens were classified into the haplotype E1, which contains 63.9% of individuals followed by E4 (16.6%), E5 (11.1%), E2 (5.5%) and E3 (2.7%), respectively. These findings indicate that the maternal lineages was involved in the origin of domestic chicken in Egypt may have roots in Indian subcontinent and other Southeast Asia. The genetic information from this study will probably pave the way to further studies for evaluation, preservation and improvement of Egyptian native chickens as genetic resources in the future. [ABSTRACT FROM AUTHOR]