TREM-2 promotes macrophage-mediated eradication of Pseudomonas aeruginosa via a PI3K/Akt pathway

Triggering receptor expressed on myeloid cells 2 (TREM-2) is a cell surface receptor abundantly expressed on myeloid lineage cells such as macrophages and dendritic cells. It is reported that TREM-2 functions as an inflammatory inhibitor in macrophages and dendritic cells. However, the role of TREM-2 in bacterial killing remains unclear. This study explored the role of TREM-2 in bacterial eradication of Pseudomonas aeruginosa (PA), a Gram-negative bacterium which causes various opportunistic infections. Phagocytosis assay assessed by flow cytometry suggested that TREM-2 was not involved in the uptake of PA by macrophages, while bacterial plate count data showed that TREM-2 was required for macrophage-mediated intracellular killing of PA. Moreover, our results demonstrated that TREM-2 promoted macrophage killing by enhancing reactive oxygen species (ROS), but not nitric oxygen (NO) production. Treatment with N-acetylcysteine, a ROS scavenger, diminished the TREM-2-mediated intracellular killing of PA. To further investigate the underlined mechanisms of TREM-2-promoted bacterial killing, we examined the activation of downstream mitogen-activated protein kinases and PI3K/Akt pathway. Western blot data showed that silencing of TREM-2 inhibited phosphorylation of Akt, but not ERK, JNK or P38. In addition, pretreatment with PI3K active product PIP3 DiC16 reversed the elevation of intracellular bacterial load in TREM-2-silenced macrophages, while PI3K inhibitor wortmannin restored the decline of bacterial load in TREM-2-overexpressed macrophages. These data together suggested that the TREM-2-mediated bacterial killing is dependent on the activation of PI3K/Akt signalling, which may provide a better understanding of the host antibacterial immune defence.

Efficacy and safety of gabapentin for treatment of postherpetic neuralgia: a meta-analysis of randomized controlled trials

BACKGROUND

Postherpetic neuralgia (PHN) is a common type of neuropathic pain occurring after resolution of herpes zoster rash. Although gabapentin is a widely used treatment, some disagreements exist about its efficacy and safety. Meta-analysis was performed to better evaluate the efficacy and safety of gabapentin for management of PHN.

METHODS

Randomized, double-blind, placebo-controlled trials of gabapentin to treat PHN were identified by searching MEDLINE, EMBASE, and CENTRAL databases. Searches were restricted to studies published in English.

RESULTS

Seven trials involving a total of 2039 participants were identified. Pooled analysis showed that gabapentin reduced PHN-related pain significantly more than placebo (mean difference, MD=-0.89, 95% CI -1.58 to -0.18, P<0.001). Gabapentin reduced pain below baseline by at least 50% in significantly more patients than did placebo (RR=1.59, 95% CI 1.35 to 1.88, P<0.001). Gabapentin was significantly more likely than placebo to lead patients to rate their global impression of change as "much improved" or "very much improved" (RR=1.82, 95% CI 1.41 to 2.35, P=0.003). Gabapentin also improved sleep quality significantly more than did placebo (MD=-0.62, 95% CI -0.67 to -0.57, P<0.001). On the other hand, patients given gabapentin were significantly more likely to experience dizziness, somnolence, peripheral edema, ataxia or gait disturbance and diarrhea. Subgroup analysis on formulation of gabapentin showed that gabapentin enacarbil had similar efficacy of pain relief with other formulations while it may be superior to others in term of compliance and safety.

CONCLUSION

This meta-analysis indicates that gabapentin is an effective and well-tolerated treatment for patients with PHN.

Genetic diversity of the Chinese traditional herb Blumea balsamifera (Asteraceae) based on AFLP markers

Blumea balsamifera is a commercially important medicinal herb in China and other parts of Asia. It is used to produce borneol. This plant grows in the wild, but resources have diminished greatly in recent years. We examined the genetic diversity of this species to help develop conservation strategies; 35 plants from five provinces were analyzed using AFLPs. Eight AFLP primer combinations generated 1367 fragments, giving a mean of 172 fragments per primer combination. Polymorphism in the germplasm analysis was found for 1360 (99.48%) of the fragments, of which 264 (19.27%) fragments were unique (accession specific) and 423 (25.33%) of the fragments were rare (present in less than 10% of the accessions). The polymorphic fragments were used to group the accessions in a UPGMA phenogram. Most grouping was geographical. In general, accessions coming from Guizhou and Guangxi showed higher diversities as these accessions were scattered in different groups. The genetic distance estimated by Jaccard similarity coefficient index showed low variability among genotypes (coefficient value ranged from 0.60 to 0.95). More attention should be given to the study and conservation of the biodiversity of this economically important genus.

Long interspersed nucleotide acid element-1 ORF-1 protein promotes proliferation and invasion of human colorectal cancer LoVo cells through enhancing ETS-1 activity

The human proto-oncogene long interspersed nucleotide acid element-1 (LINE-1) open reading frame-1 protein (ORF-1p) is involved in the progress of several cancers. The transcription factor ETS-1 can mediate the transcription of some downstream genes that play specific roles in the regulation of cancerous cell invasion and metastasis. In this study, the effects of LINE-1 ORF-1p on ETS-1 activity and on the proliferation and invasion of human colorectal cancer LoVo cells were investigated. Results showed that the overexpression of LINE-1 ORF-1p enhanced the transcription of ETS-1 downstream genes and increased their protein levels, and downregulation of the LINE-1 ORF-1p level by small interfering RNA (siRNA) reduced the transcriptional activation of ETS-1. In addition, overexpression of LINE-1 ORF-1p promoted LoVo cell proliferation and anchor-independent growth, and a knockdown of the LINE-1 protein level by siRNA reduced the proliferation and anchor-independent growth ability of LoVo cells. In vivo data revealed that LINE-1 ORF-1p overexpression increased LoVo tumor growth in nude mice, whereas the siRNA knockdown of endogenous LINE-1 ORF-1p expression decreased LoVo cell growth in nude mice. Therefore, LINE- 1 ORF-1p could promote LoVo cell proliferation and invasion both in vitro and in vivo, indicating that it might be a useful molecular target for the treatment of human colorectal cancer.

GANRA-5 protects both cultured cells and mice from various radiation types by functioning as a free radical scavenger

The radio-protective effects of the oxazolone derivative chemical compound 4-(4-methoxy-3-methoxyphenyl-methyl)-2-phenyl- 5(4H)-oxazolone (GANRA-5) against different types of radiation including X-rays, carbon ion beams, microwaves and ultraviolet light (UV) were studied. Cell proliferation/cytotoxicity assay and colony-forming assay were conducted to evaluate the toxicity of GANRA-5. To test its influence on the induction of double-stranded break (DSB) formation and genomic instability, γH2AX focus-forming assay as well as cytokinesis-block micronucleus assay was utilized. Our results indicate that GANRA-5 exhibits low toxicity, while providing high radio-protective effects for MRC-5 cells against different types of radiation. We also found that GANRA-5 acts as a free radical scavenger. Our animal studies provided evidence that GANRA-5 significantly increases the survival rate of mice after X-ray irradiation. Analyses of hemogram, visceral index and detection of superoxide dismutase (SOD) and malondialdehyde (MDA) in the viscera indicate both low toxicity of GANRA-5, combined with its ability to shield radiation risk. In conclusion, our results suggest that GANRA-5 has the potential to be used as a safe and efficient radio-protectant.

TNFα-activated stromal COX-2 signalling promotes proliferative and invasive potential of colon cancer epithelial cells

OBJECTIVES

Up to now it has been unclear whether stromal/epithelial interaction affects progression of colon cancer. This study was designed to examine effects of tumour necrosis factor alpha (TNFα)-activated stromal cyclooxygenase-2 (COX-2) signalling on proliferation and invasiveness of colon cancer epithelial cells.

MATERIALS AND METHODS

Cyclooxygenase-2 mRNA and protein were determined by real-time PCR and western blotting and prostaglandin E2 (PGE2 ) was assayed by radioimmunoassay. Cell proliferation and invasiveness were determined by transwell chamber assays and protein kinase C (PKC) was assayed by Biotrak(™) PKC Assay System.

RESULTS

Our results indicated that TNFα, a powerful inflammatory cytokine, strongly promoted COX-2 expression and PGE2 production in colon cancer-associated fibroblasts. Using in vitro assays for estimating proliferative and invasive potential, we discovered that activation of stromal COX-2 signalling significantly promoted proliferation and invasiveness of colon cancer epithelial cells. In addition, selective COX-2 inhibitor N-[2-(Cyclohexyloxy)-4-nitrophenyl]methanesulfonamide, blocked such proliferative and invasive effects on the cancer epithelial cells. In this process, PKC was involved in activation of COX-2 signalling in the fibroblasts.

CONCLUSION

We conclude that activation of stromal COX-2 signalling by TNFα played a major role in promoting proliferation and invasiveness of colon cancer epithelial cells.

Immune cells link obesity-associated type 2 diabetes and periodontitis

The clinical association between obesity-associated type 2 diabetes (T2D) and periodontitis, coupled with the increasing prevalence of these diseases, justifies studies to identify mechanisms responsible for the vicious feed-forward loop between systemic and oral disease. Changes in the immune system are critical for both obesity-associated T2D and periodontitis and therefore may link these diseases. Recent studies at the intersection of immunology and metabolism have greatly advanced our understanding of the role the immune system plays in the transition between obesity and obesity-associated T2D and have shown that immune cells exhibit similar functional changes in obesity/T2D and periodontitis. Furthermore, myeloid and lymphoid cells likely synergize to promote obesity/T2D-associated periodontitis despite complexities introduced by disease interaction. Thus the groundwork is being laid for researchers to exploit existing models to understand immune cell dysfunction and break the devastating relationship between obesity-associated T2D and oral disease.

NT-proBNP plays an important role in the effect of ibuprofen on preterm infants with patent ductus arteriosus

OBJECTIVE

The aim of this study was to clarify the role of N-terminal pro-brain natriuretic peptide, (NT-proBNP) in ibuprofen on preterm infants with patent ductus arteriosus (PDA).

PATIENTS AND METHODS

Preterm infants with PDA were enrolled in the present study. Patients were randomized into two groups: ibuprofen group received oral ibuprofen 10 mg/kg, followed by 5 mg/kg after 24 and 48 h, and the placebo group received the same volume of 5% glucose. PDA and NT-proBNP were detected during 24 hours, 3 and 7 days of age.

RESULTS

The results indicated that babies who received oral ibuprofen had higher PDA closure at 7 days after treatment (p < 0.05). Significantly decrease of NT-proBNP was found in ibuprofen group than the placebo group at 3 and 7 days (all p < 0.05).

CONCLUSIONS

Collectively, the favorable effects of ibuprofen on PDA in premature infants maybe mediated in part by the reduction of NT-proBNP level.

The role of plasma cell-free DNA detection in predicting preoperative chemoradiotherapy response in rectal cancer patients

In the present study, we studied the relationship between plasma cell-free DNA and the effect of preoperative chemoradiotherapy in patients with rectal cancer. The concentration, KRAS mutation and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation status of cell-free DNA were measured by using polymerase chain reaction (PCR) analyses. The response to chemoradiotherapy was assessed using tumor regression grading (TRG) scores. The cell-free DNA concentrations in patients with rectal cancer (n=34) were significantly higher compared to healthy controls (n=10). The 400-base pair (bp) DNA concentration, 400-/100-bp DNA ratio decreased significantly after chemoradiotherapy in the good response group. The incidence of KRAS mutation decreased significantly after chemoradiotherapy in both good and poor response groups. Higher MGMT promoter methylation status at baseline DNA was associated with a better tumor response. Therefore, cell-free DNA detection may be useful in evaluating the effect of preoperative chemoradiotherapy in patients with rectal cancer.

Abstract P1-08-24: High tumor RNA disruption is associated with increased survival in patients with locally advanced breast cancer

Background: We recently reported that epirubicin/docetaxel treatment of locally advanced breast cancer patients in the MA.22 clinical trial reduced tumor RNA integrity and that low mid-treatment tumor RNA integrity was associated with a pathologic complete response (pCR) post-treatment [Breast Cancer Res. Treat. 119:347-356]. A novel method for detection of chemotherapy-dependent loss of RNA integrity, the RNA disruption assay (RDA), has since been developed, which stratifies RNA disruption into 3 zones. Zone 1 represents drug effect inadequate to obtain a pCR [RNA disruption index (RDI) ≤ 10, NPV&gt;0.99]. Zone 2, an intermediate zone (RDI &gt;10 and ≤35) had 1 pCR in our study, while Zone 3 (RDI &gt;35) had the most pCRs (n = 7).

Methods: We have now evaluated the relationship between tumor RNA disruption and both treatment response and patient survival in all evaluable MA.22 patients (n = 85). RNA was isolated from 2-3 tumor biopsies/patient prior to and after 3 (Schedule A) or 4 (Schedule B) cycles of chemotherapy at 3- or 2-weekly intervals, respectively. RNA quality was assessed on an Agilent 2100 Bioanalyzer and RNA disruption quantified using RDA.

Results: Chemotherapy exposure reduced maximum tumor RNA content from 197 ± 24 ng/μl (mean ± standard error) pre-treatment to 94.0 ± 12.8 ng/μl mid-treatment, with maximum tumor RDI values increasing from 26.0 ± 5.8 to 88.1 ± 19.1 (p&lt;0.01 for both observations by Sign test). At the time of assessment, there were similar numbers of deceased patients across tumor RDA zones 1, 2, and 3 mid-treatment (7, 8, and 9 patients, respectively). In contrast, there were 2.9-fold more living patients with tumors in RDA zone 3 (29) than in zone 1 (10). Disease-free survival (DFS) was significantly greater (by 23.6 months) for zone 3 patients (56.9 ± 5.6 months) compared to zone 1 patients (33.3 ± 6.8 months) (p = 0.0096 by Mann Whitney Wilcoxon Test for this and all subsequent statistical tests). Living patients with tumor RDA values in zone 3 exhibited 24.5 months greater DFS than living patients with tumors in zone 1 (68.2 ± 5.5 months versus 43.7 ± 9.5 months, respectively; p = 0.015). Given their high frequency within the patient population, we were also able to conclude that greater DFS (an additional 28.6 months) could be seen for patients with estrogen receptor positive (ER+) tumors in zone 3 (59.2 ± 7.2 months) compared to patients with similar tumors in zone 1 (30.6 ± 6.3 months; p = 0.0088). Living patients with ER+ tumors in zone 3 had even greater DFS (+42.5 months) compared to living patients with ER+ tumors in zone 1 (71.8 ± 5.8 months versus 29.3 ± 8.7 months, respectively; p = 0.0012). There were also 2.5-fold more living patients with ER+ tumor RDA values in zone 3 (15) than in zone 1 (6). None of the above significant differences were observed when pre-treatment tumor RDI values or pre-treatment patient characteristics were assessed. Irrespective of breast tumor receptor subtype, chemotherapy-dependent RNA disruption mid-treatment was typically higher in patients that achieved a pCR post-treatment than for patients that did not.

Conclusions: Our findings suggest that tumor RNA disruption measurements during treatment will be highly useful to predict response and survival for locally advanced breast cancer patients. Our data demonstrate that non-responding patients (zone 1 by RDA) have considerably reduced DFS with very little chance of achieving a pCR. Such patients can be spared the toxicities associated with continuing an ineffective regimen and can be considered quickly for alternate treatments, including surgery, radiation therapy, or other anti-cancer drugs. The impact of treatment schedule and dose on RDA's ability to predict patient response and survival is currently being assessed.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-08-24.

Polymorphism of SREBP1 is associated with beef fatty acid composition in Simmental bulls

The sterol regulatory element binding factor 1 gene (SREBP1) plays an important role in the biosynthesis of fatty acids and cholesterol, and in lipid metabolism. The objective of this study was to investigate the effect of genetic polymorphisms of SREBP1 on the fatty acid composition of muscle and carcass traits in Simmental bulls and Snow Dragon black cattle. The 84-bp insertion/deletion (indel) in intron 5 of the bovine SREBP1 gene was genotyped by polymerase chain reaction to investigate its associations with traits. The results showed that the 84-bp indel in intron 5 was significantly associated with palmitoleic acid (C16:1), stearic acid (C18:0), saturated fatty acids (SFA), triglycerides (TAG), and the C16 index in Simmental bulls (P < 0.05). Cattle with the LL genotype had higher palmitic acid (C16:1), triglycerides, and C16 index but lower stearic acid (C18:0) and SFA compared to those with the LS genotype (P < 0.05). In conclusion, the 84-bp indel of SREBP1 could be used as a genetic marker for selecting Simmental breeding stock for healthier fatty acid composition.

Chinese urban-rural disparity in pandemic (H1N1) 2009 vaccination coverage rate and associated determinants: a cross-sectional telephone survey

OBJECTIVES

The present study aimed to examine the differences in pandemic (H1N1) 2009 vaccination coverage rate between urban and rural areas in China, and to explore factors associated with any urban-rural differences.

STUDY DESIGN

Cross-sectional study.

METHODS

Data were derived from a cross-sectional telephone survey performed in seven urban and two rural areas soon after the pandemic peak in China, concerning pandemic (H1N1) 2009 vaccination and associated knowledge, attitudes and practices among the general population in China. A total of 10 669 participants aged 18 years and above participated in the study.

RESULTS

Vaccination amongst rural residents was less than urban residents (8.9% vs 11.2%, P = 0.002). Among those who have not been immunized, 82.2% of rural respondents showed a willingness to get vaccinated against A/H1N1, significantly higher than that of urban respondents (55.3%). The major barrier to vaccination was reported as 'not being informed to get vaccination', of which there was a greater proportion in rural than urban population (71.9% vs 68.8%, P = 0.009). The analysis revealed a number of factors which contribute to this disparity: previous experience of vaccination against flu, degree of awareness of the free vaccination policy, and sociodemographic differences between urban and rural areas.

CONCLUSIONS

Significant discrepancies existed in the pandemic (H1N1) 2009 vaccination coverage rate and associated determinants, as well as the intention to get vaccinated between urban and rural residents. To improve the effectiveness of similar vaccination programmes in the future, campaigns for rural people need to be specifically tailored to address disparities in uptake.

Competition between antiferromagnetism and ferromagnetism in Sr2RuO4 probed by Mn and Co doping

Spin-triplet superconductivity in Sr₂RuO₄ has attracted enormous interest. Like other unconventional superconductors, superconductivity in Sr₂RuO₄ is in close proximity to magnetic instability. Undoped Sr₂RuO₄ exhibits incommensurate antiferromagnetic (AFM) fluctuations, which can evolve into static, short-range AFM order via Ti doping. Moreover, weak ferromagnetic (FM) coupling in Sr₂RuO₄ has also been suggested by NMR/neutron scattering experiments and studies on Ca_2−xSr_xRuO₄ and Sr_2−yLa_yRuO₄, implying orbital dependent magnetism. We report bulk static, short-range FM order in Sr₂RuO₄ triggered by <2% Co doping, showing superconductivity in Sr₂RuO₄ is much closer to FM instability than previously reported in Ca_2−xSr_xRuO₄. We also find Mn doping can effectively establish incommensurate AFM order, with T_N ~ 50 K for 3% Mn doping. These new results place Sr₂RuO₄ in a unique situation where superconductivity lies directly on the borderline of two distinct magnetic states, highlighting the important role of competing magnetic fluctuations in determining superconducting properties of Sr₂RuO₄.

Effects of the probiotic Arthrobacter sp. CW9 on the survival and immune status of white shrimp (Penaeus vannamei)

The probiotic Arthrobacter sp. CW9 isolated from guts of white shrimp (Penaeus vannamei) was used to improve the survival rate, growth rate and immune status of white shrimp (P. vannamei). Arthrobacter sp. CW9 was added to the saline rearing water at 0, 10(5), 10(6) and 10(7) CFU ml(-1) once every 5 days during the 24-day breeding experiment. The probiotic group had significantly higher survival rates, mean shrimp weights, phenoloxidase activity, phagocytic activity and clearance efficiency compared with the control group (P < 0.05). Therefore, Arthrobacter sp. CW9 has both probiotic and immunostimulatory properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study demonstrates that Arthrobacter sp. CW9 has both probiotic and immunostimulatory properties. Such new strain therefore represents an alternative to the use of white shrimp (Penaeus vannamei) culture. New bacterial having both probiotic and immunostimulatory properties are the major novelty of this study. The results are of industrial relevance.

High prevalence of early childhood infection by Kaposi's sarcoma-associated herpesvirus in a minority population in China

In China, KSHV seroprevalence varies considerably among different regions and ethnicities. But in Xinjiang province, located in the northwestern China, there is a very high seroprevalence of KSHV in adults of Kazak and Ughur ethnicities. However, KSHV prevalence in children and the risk factors associated with the acquisition of infection are currently not known. The aim of this study was to investigate the prevalence of KSHV infection and identify associated socioeconomic or behavioural risk factors and the humoral immune response among children in this population. This is a cross-sectional study (N = 178) to screen children and their caregivers from Xinjiang for total KSHV antibodies, KSHV neutralizing antibodies and HIV infection. Structured questionnaires were utilized to investigate risk factors associated with KSHV prevalence. KSHV seroprevalence in children and caregivers in Xinjiang was 48.3% and 64.7%, respectively. Neutralizing antibody was detected in most seropositive caregivers (93.8%) but was detected in only 5.8% of the infected children. A significant association was observed between child KSHV seroprevalence and sharing of food among family members. These results suggest that similar to other endemic areas in Africa, KSHV infection in the minority populations of Xinjiang is likely to be occurring during early childhood, probably via horizontal transmission through saliva, and results in high seroprevalence in the adult population.

Repair of a palmar soft tissue defect of the proximal interphalangeal joint with a transposition flap from the dorsum of the proximal phalanx

This article describes the use of a transposition flap raised from the dorsum of the proximal phalanx for coverage of the volar defects at the proximal interphalangeal joint. The flap was based on the first dorsal branch of the proper digital artery. From January 2007 to March 2009, 14 digits in 14 patients (10 males and 4 females) were treated. There were 5 index, 6 middle, 2 ring, and 1 little finger. All patients underwent surgery 2-9 hours (mean 5 hours) after injury. Soft tissue defects ranged in size from 1.2 × 1.7 cm to 2.1 × 2.3 cm (mean 1.7 × 2 cm). Flap size ranged from 1.5 × 1.7 cm to 2.4 × 2.7 cm (mean 2 × 2.4 cm). Mean pedicle length was 1.1 cm (range 0.8-1.4 cm). All flaps completely survived. At final follow-up from 24-29 months (mean 26 months), mean active motion arcs of the metacarpophalangeal, proximal interphalangeal, and distal interphalangeal joints were 84° (range 75-91°), 86° (range 65-100°) and 54° (range 32-80°), respectively. Our technique is useful and reliable for coverage of a palmar defect over the proximal interphalangeal joint.

Synthesis and Characterization of a Series of Novel Anionic Fumaric Polymerizable Surfactants

A series of novel anionic fumaric polymerizable surfactants with different lengths of carbon chains (C8–C14) were synthesized. The chemical structure of the surfactants was confirmed by 1H NMR, IR and MS. The values of critical micellar concentration (cmc) and γcmc of the surfactants were determined. The surface properties of this series of designed polymerizable surfactants show their potential application in the emulsion polymerization to improve the stability of the latices and water sensitivity of the films.

Psychological adjustment among left-behind children in rural China: the role of parental migration and parent-child communication

BACKGROUND

Left-behind children refer to those rural children who are under 18 years of age and are left at home when both or one of their parents migrate to urban area for work. Recent findings showed that left-behind children were disadvantaged by developmental, emotional and social problems.

METHOD

A sample of 1165 rural children and adolescents were recruited to examine the characteristics of left-behind children and explore the differences in psychological adjustment (including satisfaction, loneliness and happiness) by patterns of parental migration (i.e. no parent migrating, one parent migrating or two parents migrating) and the level of parent-child communication in rural China.

RESULTS

(1) Compared with children with one parent migrating, children with two parents migrating were separated from their parents at younger ages, for longer periods, and saw their migrant parents less frequently. (2) Children with two parents migrating reported the lowest level of satisfaction among the three groups of rural children. Both groups of children with one or two parents migrating experienced more loneliness compared with children with no parent migrating. There were no significant differences in school satisfaction and happiness among the three groups. (3) The children who reported a higher level of parent-child communication also reported a higher level of life and school satisfaction and happiness, and no differences in loneliness were found by levels of parent-child communication.

CONCLUSIONS

These results indicate that loneliness was the most common and important experience of left-behind children. Parent-child communication is important for the development of all rural children, including those who were left behind by their migrant parents.

High-performance transparent solvent-free silicone resins with stable storage and low viscosity based on new hyperbranched polysiloxanes

Five new hyperbranched polysiloxanes, for example, methylhydrogen siloxanes (MHSis), with varying concentrations of silicon–methyl (Si-Me) groups were synthesized and characterized, and then a series of MHSi/poly(methylphenylvinylsilicone) (PSi) resins were prepared to investigate the influence of the structures and concentrations of MHSi on the integrated properties of both uncured and cured MHSi/PSi resins. The results show that the compatibility between MHSi and PSi is closely related to the concentration of Si-Me groups in the MHSi as well as the molar ratio of MHSi and PSi. If MHSi has a suitable concentration of Si-Me groups, and the molar ratios of MHSi to PSi are appropriate, transparent MHSi/PSi resins with stable compatibility can be obtained. In addition, these compatible resins show good thermal stability with dynamic mechanical and dielectric properties. They exhibit a great potential for use as high-performance solvent-free silicone resins in either vacuum pressure impregnating process or liquid-molding techniques.

Surface and wire EMG crosstalk in neighbouring muscles

Surface and wire myoelectric activity of the medial gastrocnemius (MG), lateral gastrocnemius (LG) and tibialis anterior (TA) of the cat were recorded during supramaximal stimulation applied via their nerves before and after the muscle nerve to the LG and TA were cut in order to determine the amount of EMG crosstalk amongst neighbouring muscles. It was shown that the peak-to-peak (p-p) amplitude and mean absolute value (MAV) of crosstalk M waves recorded from the LG and TA after their nerve was cut did not exceed 5% of their maximal value for surface electrodes and 2.5% of their maximal value for wire electrodes. EMG crosstalk values were similar in terms of peak to peak and MAV. Surface EMG crosstalk values were significantly higher in preparations in which a substantial amount of subcutaneous fat covered the muscles, being 20 (± 16.6) % MAV and 16 (± 12) % p-p. During increasing force contraction (accomplished by orderly recruitment of motor units) from 10-100% of the maximal force of the MG the corresponding crosstalk in the LG and TA increased linearly with the EMG of the MG. It is concluded that the crosstalk problem in surface recording is negligible for most biomechanical studies in which standard EMG recording protocol is employed, yet a warning is issued against the indiscriminate recording of surface EMG from muscles covered by adipose tissue.

Effects of exercise training on left ventricular remodelling in heart failure patients: an updated meta-analysis of randomised controlled trials

Objectives:  The purpose of this updated meta-analysis was to determine whether exercise training reversed left ventricular remodelling in heart failure patients. Methods:  Articles were searched in MEDLINE, Cochrane Central Register of Controlled Trials, CINAHL, EMBASE and PubMed (up until October, 2011). The anti-remodelling benefit of exercise training was assessed by ejection fraction (EF), end-diastolic volume (EDV) and end-systolic volume (ESV). Standardised mean difference (SMD) together with 95% confidence intervals (CI) was calculated. Subgroup meta-analysis with exercise duration was also conducted. Results:  Fifteen randomised controlled trials with 813 patients were included. Aerobic exercise training improved EF (SMD = 0.44; 95% CI 0.28 to 0.61), EDV (SMD = -0.33; 95% CI -0.49 to -0.16) and ESV (SMD = -0.40; 95% CI -0.57 to -0.23). Subgroup analysis indicated that long-term aerobic exercise (≥6 months) had a marked positive effect on EF (SMD = 0.5; 95% confidence interval 0.31 to 0.69), EDV (SMD = -0.38; 95% CI -0.57 to -0.19) and ESV (SMD = -0.48; 95% CI -0.67 to -0.29), but there was no evidence of benefit with short-term aerobic exercise (<6 months): EF (SMD = 0.27; 95% CI -0.08 to 0.61), EDV (SMD = -0.14; 95% CI -0.48 to 0.21) and ESV (SMD = -0.08; 95% CI -0.47 to 0.30). Strength training (alone or plus aerobic training) was not associated with improvements in EDV and ESV, with all confidence intervals including 0. Conclusions:  Aerobic exercise training, especially long-term duration (≥6 months) reverses left ventricular remodelling in clinically stable patients with heart failure. Strength training (alone or plus aerobic training) did not improve or worsen ventricular remodelling.

Widely tunable midinfrared difference frequency generation in orientation-patterned GaAs pumped with a femtosecond Tm-fiber system

We demonstrate a midinfrared source tunable from 6.7 to 12.7 μm via difference frequency generation (DFG) in orientation-patterned GaAs, with 1.3 mW average output power. The input pulses are generated via Raman self-frequency shift of a femtosecond Tm-doped-fiber laser system in a fluoride fiber. We numerically model the DFG process and show good agreement between simulations and experiments. We use this numerical model to show an improved design using longer pump pulses.

Interleukin 28B polymorphisms are the only common genetic variants associated with low-density lipoprotein cholesterol (LDL-C) in genotype-1 chronic hepatitis C and determine the association between LDL-C and treatment response

Low-density lipoprotein cholesterol (LDL-C) levels and interleukin 28B (IL28B) polymorphism are associated with sustained viral response (SVR) to peginterferon/ribavirin (pegIFN/RBV) for chronic hepatitis C (CHC) infection. IL28B has been linked with LDL-C levels using a candidate gene approach, but it is not known whether other genetic variants are associated with LDL-C, nor how these factors definitively affect SVR. We assessed genetic predictors of serum lipid and triglyceride levels in 1604 patients with genotype 1 (G1) chronic hepatitis C virus (HCV) infection by genome-wide association study and developed multivariable predictive models of SVR. IL28B polymorphisms were the only common genetic variants associated with pretreatment LDL-C level in Caucasians (rs12980275, P = 4.7 × 10(-17), poor response IL28B variants associated with lower LDL-C). The association was dependent on HCV infection, IL28B genotype was no longer associated with LDL-C in SVR patients after treatment, while the association remained significant in non-SVR patients (P < 0.001). LDL-C was significantly associated with SVR for heterozygous IL28B genotype patients (P < 0.001) but not for homozygous genotypes. SVR modelling suggested that IL28B heterozygotes with LDL-C > 130 mg/dL and HCV RNA ≤600 000 IU/mL may anticipate cure rates >80%, while the absence of these two criteria was associated with an SVR rate of <35%. IL28B polymorphisms are the only common genetic variants associated with pretreatment LDL-C in G1-HCV. LDL-C remains significantly associated with SVR for heterozygous IL28B genotype patients, where LDL-C and HCV RNA burden may identify those patients with high or low likelihood of cure with pegIFN/RBV therapy.

Predictors of relapse in chronic hepatitis B after discontinuation of anti-viral therapy

BACKGROUND

Optimal duration of anti-viral therapy in chronic hepatitis B virus (HBV) infection remains unclear.

AIM

To investigate factors that could predict relapse after stopping anti-viral agents.

METHODS

Chronic hepatitis B patients who were treated with anti-viral agents (lamivudine, adefovir, entecavir) and have stopped the treatment were recruited. Anti-viral agents were stopped according to the recommendations of the Asian Pacific Association for the Study of the Liver. Virological relapse was defined as an increase in serum HBV DNA to >1000 copies/mL after discontinuation of treatment.

RESULTS

Eighty-four (69 treatment naïve and 15 lamivudine resistant) patients were eligible for this study. Thirty-seven patients developed virological relapse at 4.3 ± 2.9 (range 1-11) months after discontinuation of therapy. The 1-year cumulative probability of virological relapse was 42% and 47% in HBeAg (hepatitis B e antigen)-positive (n = 41) and HBeAg (hepatitis B e antigen)-negative (n = 43) patients, respectively. On multivariate analysis by Cox proportional hazard model, pre-existing lamivudine resistance, delayed suppression of HBV DNA to undetectable level during anti-viral therapy and to a higher HBsAg (hepatitis B surface antigen) level at the end of treatment were associated with virological relapse. Twelve of the 15 (80%) lamivudine resistant patients developed virological relapse. Among the 11 treatment naïve patients who had HBsAg ≤ 2 log IU/mL at the end of treatment, 1 (9%) of them had virological relapse.

CONCLUSIONS

Treatment cessation among lamivudine resistant patients is associated with high risk of virological relapse. Serum HBsAg level at the end of treatment and rate of HBV DNA suppression can provide supplementary information to guide the timing of stopping anti-viral drugs.

Predictors of relapse in chronic hepatitis B after discontinuation of anti-viral therapy

BACKGROUND

Optimal duration of anti-viral therapy in chronic hepatitis B virus (HBV) infection remains unclear.

AIM

To investigate factors that could predict relapse after stopping anti-viral agents.

METHODS

Chronic hepatitis B patients who were treated with anti-viral agents (lamivudine, adefovir, entecavir) and have stopped the treatment were recruited. Anti-viral agents were stopped according to the recommendations of the Asian Pacific Association for the Study of the Liver. Virological relapse was defined as an increase in serum HBV DNA to >1000 copies/mL after discontinuation of treatment.

RESULTS

Eighty-four (69 treatment naïve and 15 lamivudine resistant) patients were eligible for this study. Thirty-seven patients developed virological relapse at 4.3 ± 2.9 (range 1-11) months after discontinuation of therapy. The 1-year cumulative probability of virological relapse was 42% and 47% in HBeAg (hepatitis B e antigen)-positive (n = 41) and HBeAg (hepatitis B e antigen)-negative (n = 43) patients, respectively. On multivariate analysis by Cox proportional hazard model, pre-existing lamivudine resistance, delayed suppression of HBV DNA to undetectable level during anti-viral therapy and to a higher HBsAg (hepatitis B surface antigen) level at the end of treatment were associated with virological relapse. Twelve of the 15 (80%) lamivudine resistant patients developed virological relapse. Among the 11 treatment naïve patients who had HBsAg ≤ 2 log IU/mL at the end of treatment, 1 (9%) of them had virological relapse.

CONCLUSIONS

Treatment cessation among lamivudine resistant patients is associated with high risk of virological relapse. Serum HBsAg level at the end of treatment and rate of HBV DNA suppression can provide supplementary information to guide the timing of stopping anti-viral drugs.

Creation of nanostructures by interference lithography for modulation of cell behavior

Emerging evidence of the striking differences that can be induced in the behavior of biological cells through topographical modulation of physically and chemically patterned nanostructured surfaces provides a great impetus for developing novel cellular-scale and sub-cellular-scale nanopatterned substrates and for employing them for exciting new applications in life and medical sciences and biotechnology. However, the lack of availability of cost-effective, large-surface-area nanofabricated substrates of appropriate dimensions and features has proved to be a major impediment for research in this area. Here, we demonstrate a simple and cost-effective method based on interference lithography to produce spatially precise and wide-surface-coverage silicon- and polymer-based nanostructures to study how cells react to nanoscale structures or surfaces.

XRCC1 Arg399Gln and Arg194Trp polymorphisms in prostate cancer risk: a meta-analysis

Epidemiological studies have evaluated the association between X-ray repair cross-complementing group 1 gene (XRCC1) Arg399Gln and Arg194Trp polymorphisms and risk of prostate cancer (PCa). However, the results from the published studies on the association between these two XRCC1 polymorphisms and PCa risk are conflicting. To derive a more precise estimation of association between the XRCC1 polymorphisms and risk of PCa, we performed a meta-analysis. A comprehensive search was conducted to identify all case-control studies of XRCC1 polymorphisms and PCa risk. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association. Overall, we found that both Arg399Gln and Arg194Trp polymorphisms were not significantly associated with PCa risk. However, in stratified analysis by ethnicity, we found that the Arg399Gln polymorphism was significantly associated with PCa risk in Asian population (Gln/Gln vs Arg/Arg: OR=1.46, 95% CI: 1.05-2.03, P=0.03; Gln/Gln vs Arg/Gln+Arg/Arg: OR=1.48, 95% CI: 1.12-1.95, P=0.01). In this meta-analysis, we found that both Arg399Gln and Arg194Trp polymorphisms were not related to overall PCa risk. However, in subgroup analysis we found a suggestion that XRCC1 399Gln allele might be a low-penetrent risk factor for PCa only in Asian men.

Ischaemia-induced retinal neovascularisation and diabetic retinopathy in mice with conditional knockout of hypoxia-inducible factor-1 in retinal Müller cells

AIMS/HYPOTHESIS

Retinal Müller cells are known to produce inflammatory and angiogenic cytokines, which play important roles in diabetic retinopathy. Hypoxia-inducible factor (HIF)-1 has been shown to play a crucial role in retinal inflammation and neovascularisation. We sought to determine the role of Müller cell-derived HIF-1 in oxygen-induced retinopathy (OIR) and diabetic retinopathy using conditional Hif-1α (also known as Hif1a) knockout (KO) mice.

METHODS

Conditional Hif-1α KO mice were generated by crossing mice expressing cyclisation recombinase (cre, also known as P1_gp003) in Müller cells with floxed Hif-1α mice and used for OIR and streptozotocin-induced diabetes to induce retinal neovascularisation and inflammation, respectively. Abundance of HIF-1α and pro-angiogenic and pro-inflammatory factors was measured by immunoblotting and immunohistochemistry. Retinal neovascularisation was visualised by angiography and quantified by counting pre-retinal nuclei. Retinal inflammation was evaluated by leucostasis and vascular leakage.

RESULTS

While the Hif-1α KO mice showed significantly decreased HIF-1α levels in the retina, they exhibited no apparent histological or visual functional abnormalities under normal conditions. Compared with wild-type counterparts, Hif-1α KO mice with OIR demonstrated attenuated overproduction of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule (ICAM)-1, reduced vascular leakage and alleviated neovascularisation in the retina. Under diabetes conditions, disruption of Hif-1α in Müller cells attenuated the increases of retinal vascular leakage and adherent leucocytes, as well as the overproduction of VEGF and ICAM-1.

CONCLUSIONS/INTERPRETATION

Müller cell-derived HIF-1α is a key mediator of retinal neovascularisation, vascular leakage and inflammation, the major pathological changes in diabetic retinopathy. Müller cell-derived HIF-1α is therefore a promising therapeutic target for diabetic retinopathy.