Whole-Genome Sequencing of Native Sheep Provides Insights into Rapid Adaptations to Extreme Environments.

Global climate change has a significant effect on extreme environments and a profound influence on species survival. However, little is known of the genome-wide pattern of livestock adaptations to extreme environments over a short time frame following domestication. Sheep (Ovis aries) have become well adapted to a diverse range of agroecological zones, including certain extreme environments (e.g., plateaus and deserts), during their post-domestication (approximately 8-9 kya) migration and differentiation. Here, we generated whole-genome sequences from 77 native sheep, with an average effective sequencing depth of ∼5× for 75 samples and ∼42× for 2 samples. Comparative genomic analyses among sheep in contrasting environments, that is, plateau (>4,000 m above sea level) versus lowland (<100 m), high-altitude region (>1500 m) versus low-altitude region (<1300 m), desert (<10 mm average annual precipitation) versus highly humid region (>600 mm), and arid zone (<400 mm) versus humid zone (>400 mm), detected a novel set of candidate genes as well as pathways and GO categories that are putatively associated with hypoxia responses at high altitudes and water reabsorption in arid environments. In addition, candidate genes and GO terms functionally related to energy metabolism and body size variations were identified. This study offers novel insights into rapid genomic adaptations to extreme environments in sheep and other animals, and provides a valuable resource for future research on livestock breeding in response to climate change.

[Hydrophilic Surface Modification of Polydimethylsiloxane with UV/Ozone Treatment].

The UV/ozone surface treatment was a simple and low cost hydrophilic modification method. In this paper，UV/ozone treatment is utilized to hydrophilize the surface of PDMS and the results are compared. Contact angle is applied to estimate the effect and stability of the modified surfaces. The results show that the contact angle is around 60° on the PDMS surface with UV/ozone treatment after 12 hours, and it can maintain the surface hydrophilicity in two weeks under ambient atmosphere. The results of FTIR spectroscopy indicate that many chemical functional groups of PDMS surface have been changed with UV/ozone modification, ­CH3 hydrophobic group gradually decrease over time, ­OH and Si­OH hydrophilic groups increase obviously, and the characteristic peaks of SiO2 gradually appear. Through SEM/EDS analysis, it has been found that the major constituent of the surface of PDMS is SiO2 after the surface modification. These results demonstrate that the more hydrophilic groups and the glass-like SiOx layer are formed on the PDMS surface modified with UV/ozone, which enhance the surface hydrophilic and minimize the hydrophobic recovery.

Effect of b value on monitoring therapeutic response by diffusion-weighted imaging.

AIM: To explore the diffusion gradient b-factor that optimizes both apparent diffusion coefficient (ADC) measurement and contrast-to-noise (CNR) for assessing tumor response to transarterial chemoembolization (TACE) in a rabbit model. METHODS: Twelve New Zealand white rabbits bearing VX2 tumors in the liver were treated with TACE. Diffusion-weighted imaging (DWI) with various b values was performed using the same protocol before and 3 d after treatment with TACE. ADC values and CNR of each tumor pre- and post-treatment with different b factors were analyzed. Correlation between ADC values and extent of necrosis in histological specimens was analyzed by a Pearson's correlation test. RESULTS: The quality of diffusion-weighted images diminished as the b value increased. A substantial decrease in the mean lesion-to-liver CNR was observed on both pre- and post-treatment DW images, the largest difference in CNR pre- and post-treatment was manifested at a b value of 1000 s/mm(2) (P = 0.036 ). The effect of therapy on diffusion early after treatment was shown by a significant increase in ADCs (P = 0.007), especially with large b factors (>= 600 s/mm(2)). The mean percentage of necrotic cells present within the tumor was 76.3%-97.5%. A significant positive correlation was found between ADC values and the extent of necrosis with all b values except for b200, a higher relative coefficient between ADC values and percentage of necrosis was found on DWI with b1000 and b2000 (P = 0.002 and 0.006, respectively). CONCLUSION: An increasing b value of up to 600 s/mm(2) would increase ADC contrast pre- and post-treatment, but decrease image quality. Taking into account both CNR and ADC measurement, diffusion-weighted imaging obtained with a b value of 1000 s/mm(2) is recommended for monitoring early hepatic tumor response to TACE.

Predicting prognosis of rectal cancer patients with total mesorectal excision using molecular markers.

AIM: To explore the prognostic variables in rectal cancer patients undergoing curative total mesorectal excision and the effect of postoperative chemotherapy in advanced rectal cancer. METHODS: A total of 259 consecutive rectal cancer patients treated with curative total mesorectal excision between 1999 and 2004 were collected. p53, p21, PCNA, and CD44v6 were examined using immunohistochemistry (IHC). The correlation between clinicopathological or molecular variables and clinical outcomes, including local recurrence, metastasis, disease-free survival and overall survival, was analyzed. RESULTS: The median follow-up was 44 mo. Five-year survival rates and 5-year disease free survival rates were 75.43% and 70.32%, respectively. Multi-analysis revealed TNM staging, preoperative CEA, and CD44v6 level were independent risk factors predicting overall survival or disease free survival. The hazard ratio of peroperative CEA was 2.65 (95% CI 1.4-5) and 3.10 (95% CI 1.37-6.54) for disease free survival and overall survival, respectively. The hazard ratio of CD44v6 was 1.93 (95% CI 1.04-3.61) and 2.21 (95% CI 1.01-4.88) for disease free survival and overall survival, respectively. TNM staging was the only risk factor predicting local recurrence. Postoperative chemotherapy without radiotherapy did not improve patients' outcome. CONCLUSION: TNM staging, preoperative CEA and CD44v6 were independent prognostic factors for rectal cancer patients with total mesorectal excision. Postoperative chemotherapy may be only used together with radiotherapy for rectal cancer patients.