Coherent Subcycle Optical Shock from a Superluminal Plasma Wake

We propose exploiting the superluminal plasma wake for coherent Cherenkov radiation by injecting a relativistic electron beam (REB) into a plasma with a slowly varying density up-ramp. Using three-dimensional particle-in-cell and far-field time-domain radiation simulations, we show that an isolated subcycle pulse is coherently emitted towards the Cherenkov angle by bubble-sheath electrons successively at the rear of the REB-induced superluminal plasma wake. A theoretical model based on a superluminal current dipole has been developed to interpret such coherent radiation, and agrees well with the simulation results. This radiation has ultrashort attosecond-scale duration and high intensity, and exhibits excellent directionality with ultralow angular divergence and stable carrier envelope phase. Its intensity increases with the square of the propagation length and its central frequency can be easily tuned over a wide range, from the far infrared to the ultraviolet.

Phylodynamic analysis and spike protein mutations in porcine deltacoronavirus with a new variant introduction in Taiwan

Porcine deltacoronavirus (PDCoV) is a highly transmissible intestinal pathogen that causes mild to severe clinical symptoms, such as anorexia, vomiting, and watery diarrhea in pigs. By comparing the genetic sequences of the spike glycoprotein between historical and current Taiwanese PDCoV strains, we identified a novel PDCoV variant that displaced the PDCoV responsible for the 2015 epidemic. This PDCoV variant belongs to a young population within the US lineage, and infected pigs carry high concentrations of the virus. It also has several critical point mutations and an amino acid insertion at position 52 that may enhance the affinity between the B-cell epitopes located in the N-terminal domain with its complementarity regions, consequently facilitating binding or penetration between the fusion peptide and cellular membrane. Furthermore, viral protein structure prediction demonstrated that these amino acid changes may change the ability of the virus to bind to the receptor, which may consequently alter virus infectivity. Our results hence suggest the emergence of new PDCoV strains in Taiwan with the potential for greater transmission and pathogenesis.

Interaction of DNA Repair Gene XPC With Smoking and Betel Quid Chewing Behaviors of Oral Cancer

BACKGROUND/AIM

Xeroderma pigmentosum complementation group C (XPC) is reported to play important roles in DNA integrity and genomic instability, however, the contribution of XPC to oral carcinogenesis is largely uncertain. Therefore, we aimed at examining the contribution of XPC genotypes to oral cancer.

MATERIALS AND METHODS

The genotypes of XPC rs2228001 and rs2228000 were examined among 958 oral cancer patients and 958 control subjects by polymerase chain reaction-restriction fragment length polymorphism methodology and corresponding DNA repair capacity was checked.

RESULTS

First, the percentages of XPC rs2228001 AC and CC were higher among oral cancer patients than controls. Second, no significant association was observed regarding XPC rs2228000. Third, there was a synergistic influence of smoking and betel quid chewing behaviors and XPC rs2228001 genotype on oral cancer risk. Last, functional experiments showed DNA repair capacity was lower for AC/CC carriers than AA carriers.

CONCLUSION

XPC rs2228001 C allele, which was associated with decreased DNA repair capacity, may interact with smoking and betel quid chewing behaviors on oral cancer risk.

Gelatin/Chitosan Bilayer Patches Loaded with Cortex Phellodendron amurense/Centella asiatica Extracts for Anti-Acne Application

Acne is a chronic inflammatory skin disease that often occurs with anaerobic Propionibacterium acnes (P. acnes). Anti-acne patches, made of hydrocolloid or hydrogel, have become a popular way of topical treatment. The outer water-impermeable layer of commercial patches might create hypoxic conditions and promote P. acnes growth. In this study, gelatin/chitosan (GC) bilayer patches were prepared at different temperatures that included room temperature (RT), −20 °C/RT, and −80 °C/RT. The most promising GC bilayer patch (−80 °C /RT) contained a dense upper layer for protection from bacteria and infection and a porous lower layer for absorbing pus and fluids from pimples. The anti-acne bilayer patch was loaded with Cortex Phellodendri amurensis (PA) and Centella asiatica (CA) extracts. PA extract could inhibit the growth of P. acnes and CA extract was reported to improve wound healing and reduce scar formation. Moreover, the water retention rate, weight loss rate, antibacterial activity, and in vitro cytotoxicity of the patches were investigated. The porous structure of the patches promoted water retention and contributed to absorbing the exudate when used on open acne wounds. The GC bilayer patches loaded with PA/CA extracts were demonstrated to inhibit the growth of P. acnes, and accelerate the skin fibroblast cell viability. Based on their activities and characteristics, the GC bilayer patches with PA/CA extract prepared at −80 °C/RT obtain the potential for the application of acne spot treatment.

Association of Murine Double Minute 2 Genotypes and Lung Cancer Risk

AIM

The aim of this study was to evaluate the contribution of human mouse double minute 2 (MDM2) gene polymorphisms to the risk of Taiwan lung cancer.

MATERIALS AND METHODS

In this case-control study, the association of MDM2 rs2279744 genotypes with lung cancer risk was investigated among 358 lung cancer patients and 716 age-, gender- and smoking status-matched controls in Taiwan.

RESULTS

The percentages of MDM2 rs2279744 GT and GG genotypes were 50.0% and 27.4% in lung cancer group and 50.0% and 26.5% in control group, respectively [odds ratio (OR)=1.03 and 1.07, 95% confidence interval (CI)=0.75-1.43 and 0.75-1.53, respectively]. The analysis about allelic frequency showed that G allele at MDM2 rs2279744 conferred a non-significant increased cancer risk (OR=1.03, 95%CI=0.86-1.24).

CONCLUSION

Polymorphisms of MDM2 rs2279744 may play a role in lung carcinogenesis. However, the studied genotypes were not shown as predictors of lung cancer susceptibility.

Genetic characterization of feline panleukopenia virus from dogs in Vietnam reveals a unique Thr101 mutation in VP2

Background

Canine parvovirus type 2 (CPV-2) and feline parvovirus (FPV) are known as the main causes of several serious diseases and have a severe impact on puppies and kittens, respectively. FPV and new CPV-2 variants are all able to infect cats, causing diseases indistinguishable from feline panleukopenia. However, FPV only replicates efficiently in feline cells in vitro and replicates in dogs in the thymus and bone marrow without being shed in feces. In our previous study, the genotypes of six parvoviral isolates were unable to be identified using a SimpleProbe^® real-time PCR assay.

Methods

In the present study, we characterized previously unidentified FPV-like viruses isolated from dogs in Vietnam. The six isolates were utilized to complete VP2 gene sequencing and to conduct phylogenetic analyses.

Results

Sequence analysis of the six parvoviral strains identified the species as being similar to FPV. Phylogenetic analysis demonstrated that the complete VP2 genes of the strains are similar to those of FPV. The FPV-like strains contain a Thr101 mutation in the VP2 protein, which is different from prototype FPV strains.

Discussion

Our data provide evidence for the existence of changes in the charge, protein contact potential and molecular surface of the core of the receptor-binding size with an Ile101 to Thr101 mutation. This is also the first study to provide reliable evidence that FPV may be a threat to the Vietnamese dog population.

Autonomic dysfunction as an independent risk factor for uncontrolled inflammation in chronic rhinosinusitis following functional endoscopic sinus surgery

BACKGROUND

Chronic rhinosinusitis (CRS) is a multi-factorial disorder that causes systemic symptoms beyond rhinologic symptoms alone. A possible association between autonomic nervous system (ANS) dysfunction and CRS has been identified; however, few studies have confirmed this observation. In this study, we prospectively measured changes in ANS dysfunction symptoms following functional endoscopic sinus surgery (FESS) and explored the impact of ANS dysfunction on surgical outcomes of CRS.

METHODOLOGY

Patients diagnosed with CRS who consented to surgical intervention were included prospectively. All patients completed the Sino-nasal Outcome Test-22 (SNOT-22) and the 31-item Composite Autonomic Symptom Score (COMPASS 31) questionnaires before the operation and during the follow-up period. Clinical demographic data, Lund-Mackay, and modified Lund-Kennedy scores were recorded and measured.

RESULTS

A total of 102 patients were enrolled. The median SNOT-22 and COMPASS 31 scores significantly improved following FESS from 43.0 to 14.0 and 21.0 to 11.2 (all P less than 0.001), respectively. FESS led to a significant reduction in the prevalence of various ANS dysfunction symptoms. In multivariate analyses, revision surgeries (odds ratio [OR] 5.012, 95% confidence interval [CI] 1.52416.489; P=0.008), CRS with nasal polyps (OR 4.071, 95% CI 1.454-11.40; P=0.008), and higher Pre-FESS COMPASS 31 scores (OR 1.043, 95% CI 1.003-1.084; P=0.036) were independent risk factors for uncontrolled inflammation following FESS.

CONCLUSIONS

ANS dysfunction symptoms are prevalent in CRS and higher preoperative COMPASS 31 scores correspond with poor surgical outcomes. Following FESS, the majority of ANS dysfunction symptoms can be alleviated. Further investigations are required to explore the possible mechanism of how ANS is involved in the pathogenesis of CRS.

Association of Matrix Metalloproteinase-9 rs3918242 Promoter Genotypes With Colorectal Cancer Risk

BACKGROUND/AIM

Matrix metalloproteinase-9 (MMP-9) is responsible for modifying extracellular components and plays a crucial role in the metastatic behavior of cancer. This study aimed at examining the role of MMP-9 rs3918242 genotypes on colorectal cancer (CRC) risk.

MATERIALS AND METHODS

A total of 362 CRC patients and 362 healthy subjects in Taiwan, were examined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology.

RESULTS

The MMP-9 rs3918242 TT genotype carriers had a slightly increased risk of CRC compared to CC carriers (p=0.1642, OR=1.88, 95% CI=0.84-4.16). Patients of CT/TT genotypes were on significantly higher risk of metastasis (p=0.0027) than those of CC genotype. No obvious association was found between MMP-9 genotype and CRC risk among ever-smokers, non-smokers, non-alcohol drinkers or alcohol drinkers. No significant correlation was observed between MMP-9 genotypic distributions with age, gender, tumor size or location.

CONCLUSION

MMP-9 rs3918242 genotypes may interact with BMI to serve as a predictor for higher CRC risk, and independently as a predictor for metastasis.

The association of matrix metalloproteinas-2 promoter polymorphisms with lung cancer susceptibility in Taiwan

Matrix metalloproteinases-2 (MMP2) has been reported to be overexpressed in various types of cancer. However, the contribution of various genotypes of MMP2 to lung cancer is controversial and not yet been examined in Taiwan. Therefore, in the current study, we investigated the association of MMP2 genotypes with lung cancer risk among Taiwanese. In this hospital-based, case-control study, 358 lung cancer patients and 716 age- and gender-matched healthy controls were recruited, and the genotypic distributions of MMP2-1306 and MMP2- 735 were determined. Then, their association with lung cancer was evaluated, and their interaction with personal smoking status was also examined via stratification analysis. The results showed that the percentages of variant CT and TT at MMP2-1306 were 17.3% and 1.7% among the lung cancer patients, respectively, much lower than those of 28.7% and 2.4%, respectively, among the healthy controls (P for trend = 0.0001). The allelic frequency distribution analysis showed that the variant T allele at MMP2-1306 conferred a statistically significantly lower lung cancer risk than the wild-type C allele (adjusted odds ratio = 0.54, 95% confidence interval = 0.41-0.72, P = 0.0001). There was an obvious effect of MMP2-1306 genotype on lung cancer risk among the subpopulations of ever smokers but not nonsmokers. As for the genotypes of MMP2-735, there was no such differential distribution in the aspects of genotypic or allelic frequencies, or combinative effects with smoking status. The genotypes of MMP2-1306 may act as a biomarker in determining personal susceptibility to lung cancer in Taiwan. The contribution of MMP2 genotypes alone and its joint effects with personal cigarette smoking habit on lung cancer susceptibility should be taken into consideration of the clinical practices for early detection and prediction of lung cancer in Taiwan.

Contribution of Murine Double Minute 2 Genotypes to Colorectal Cancer Risk in Taiwan

BACKGROUND/AIM

The genomic role of human mouse double minute 2 (MDM2) in colorectal cancer (CRC) is unclear, therefore, our study aimed to evaluate the contribution of MDM2 genotype to the risk of CRC in Taiwan.

MATERIALS AND METHODS

In this case-control study, MDM2 SNP309 T to G (rs2279744) genotypes were determined and their association with CRC risk were investigated among 362 patients with CRC and 362 age- and gender-matched healthy controls in central Taiwan. In addition, the interaction of MDM2 SNP309 genotypes with personal behaviors and clinicopathological features were also examined.

RESULTS

The percentage of variant GG for the MDM2 SNP309 genotype was 30.9% in the CRC group and 24.0% in the control group, respectively (odds ratio (OR)=1.78, 95% confidence interval (CI)=1.25-2.86, p=0.0057). The allelic frequency distribution analysis showed that the variant G allele of MDM2 SNP309 conferred a significantly increased susceptibility to CRC compared with the wild-type T allele (OR=1.32, 95% CI=1.14-1.69, p=0.0062). As for the gene-lifestyle interaction, there was an obvious joint effect of MDM2 SNP309 GG genotype on the risk of CRC among ever-smokers and non-alcohol drinkers, but not non-smoker or alcohol drinker subgroups. No statistically significant correlation was observed between MDM2 SNP309 genotypic distributions and age, gender, tumor size, location or metastasis status.

CONCLUSION

The genotypes of MDM2 SNP309 may allow forr early detection of and predictor for CRC risk, especially among smokers and non-alcohol drinkers, but not for prognosis. The combined effects of MDM2 SNP309 and other genes (such as matrix metalloproteinases) on CRC susceptibility and prognosis, should also be taken into consideration in the era of precision medicine.

The Contribution of MMP-7 Genotypes to Colorectal Cancer Susceptibility in Taiwan

BACKGROUND/AIM

Matrix metalloproteinases (MMPs) play important roles in inflammation and carcinogenesis, but the genotypic role of MMP-7 has never been investigated in colorectal cancer (CRC) among the Taiwanese. Therefore, in this study we aimed to evaluate the contribution of MMP-7 genotypes to the risk of CRC in Taiwan.

MATERIALS AND METHODS

In this case-control study, MMP-7 A-181G and C-153T promoter genotypes were determined and their association with CRC risk were investigated among 362 CRC patients and 362 age- and gender-matched healthy controls. In addition, the interaction of MMP-7 genotypes and personal behaviors were also examined.

RESULTS

The percentages of variant AG and GG for MMP-7 A-181G genotypes were 10.5% and 1.7% in the CRC group and 11.9% and 2.2% in the control group, respectively (p for trend=0.7145). The allelic frequency distribution analysis showed that the variant G allele of MMP-7 A-181G conferred a slight but non-significant decreased CRC susceptibility to the wild-type C allele (odds ratio (OR)=0.86, 95% confidence interval (CI)=0.64-1.31, p=0.37). Taiwanese all harbour the CC genotype at MMP-7 C-153T. As for the gene-lifestyle interaction, there were no obvious joint effects of MMP-7 A-181G genotype on the risk of CRC among ever smoker, alcohol drinker, non-smoker or non-drinker subgroups. No statistically significant correlation was observed between MMP-7 A-181G genotypic distributions and age, gender, tumor size, location or metastasis status.

CONCLUSION

The genotypes of MMP-7 A-181G may play an indirect role in determining personal susceptibility to CRC and prognosis. The further genotyping work on MMP-7 and other genes (such as other MMPs, oncogenes and tumor suppression genes) on CRC susceptibility and prognosis, should be taken into consideration spontaneously in the precision medicine era.

High-quality thulium iron garnet films with tunable perpendicular magnetic anisotropy by off-axis sputtering - correlation between magnetic properties and film strain

Thulium iron garnet (TmIG) films with perpendicular magnetic anisotropy (PMA) were grown on gadolinium gallium garnet (GGG) (111) substrates by off-axis sputtering. High-resolution synchrotron radiation X-ray diffraction studies and spherical aberration-corrected scanning transmission electron microscope (Cs-corrected STEM) images showed the excellent crystallinity of the films and their sharp interface with GGG. Damping constant of TmIG thin film was determined to be 0.0133 by frequency-dependent ferromagnetic resonance (FMR) measurements. The saturation magnetization (Ms) and the coercive field (Hc) were obtained systematically as a function of the longitudinal distance (L) between the sputtering target and the substrate. A 170% enhancement of PMA field (H⊥) was achieved by tuning the film composition to increase the tensile strain. Moreover, current-induced magnetization switching on a Pt/TmIG structure was demonstrated with an ultra-low critical current density (jc) of 2.5 × 106 A/cm2, an order of magnitude smaller than the previously reported value. We were able to tune Ms, Hc and H⊥ to obtain an ultra-low jc of switching the magnetization, showing the great potential of sputtered TmIG films for spintronics.

Association of Matrix Metalloproteinase-7 Genotypes to the Risk of Oral Cancer in Taiwan

BACKGROUND/AIM

Matrix metalloproteinases (MMPs) play a critical role in inflammation and carcinogenesis, and the expression of mRNA MMP7 in oral squamous cell carcinoma tissues was higher than in the oral lichen planus or normal oral mucosa. However, the genotypic role of MMP7 has never been examined in oral cancer. Therefore, in the current study we aimed to examine the contribution of genotypic variants in the promoter region of MMP7 (A-181G and C-153T) to oral cancer risk in Taiwan.

MATERIALS AND METHODS

In this hospital-based case-control study, 788 patients with oral cancer and 956 gender-and age-matched healthy controls were genotyped for MMP7 A-181G and C-153T via polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology.

RESULTS

The distribution pattern of AA, AG and GG for MMP7 promoter A-181G genotype was 88.2, 10.4 and 1.4% in the oral cancer patient group and 89.0, 9.3 and 1.7% in the healthy control group, respectively (p for trend=0.6779), non-significantly differentially distributed between the two groups. There is no polymorphic genotype for MMP7 C-153T among Taiwanese. The comparisons in allelic frequency distribution also support the findings that G allele may not be the risk determinant allele for oral cancer. There is no interaction between the genotypes of MMP7 with age, gender, smoking, alcohol or betel quid consumption on oral cancer risk.

CONCLUSION

Our results indicate that the MMP7 promoter genotypes only play an indirect role in determining the personal susceptibility to oral cancer in Taiwan.

The Contribution of Matrix Metalloproteinase-8 Promoter Polymorphism to Oral Cancer Susceptibility

BACKGROUND/AIM

Metalloproteinases (MMPs) are a family of multifunctional proteins reported to be overexpressed in several types of cancers. However, the contribution of MMP8 genotype to oral cancer has not been elucidated. In this study, we focused on the contribution of polymorphisms in the promoter region of MMP-8 (C-799T) and two non-synonymous polymorphisms (Val436Ala and Lys460Thr) to Taiwanese oral cancer.

MATERIALS AND METHODS

In this case-control study, MMP-8 genotype, was examined among 788 patients with oral cancer and 956 gender- and age-matched healthy controls regarding its potential to determine oral cancer risk.

RESULTS

The distributions of MMP-8 C-799T, Val436Ala and Lys460Thr genotypes were not different between the oral cancer and non-cancer control groups. We also analyzed the allelic frequency distributions and no significant difference was found. As for gene-environment interaction analysis, there was an increased risk for smokers, alcohol drinkers or betel quid chewers with variant MMP-8 C-799T or Val436Ala genotypes.

CONCLUSION

Our findings suggest that the polymorphisms at MMP-8 C-799T or Val436Ala may not play a major role in mediating personal risk of oral cancer; however, the detailed mechanisms require further investigation.

Strongly exchange-coupled and surface-state-modulated magnetization dynamics in Bi2Se3/yttrium iron garnet heterostructures

Harnessing the spin–momentum locking of topological surface states in conjunction with magnetic materials is the first step to realize novel topological insulator-based devices. Here, we report strong interfacial coupling in Bi₂Se₃/yttrium iron garnet (YIG) bilayers manifested as large interfacial in-plane magnetic anisotropy (IMA) and enhancement of damping probed by ferromagnetic resonance. The interfacial IMA and damping enhancement reaches a maximum when the Bi₂Se₃ film approaches its two-dimensional limit, indicating that topological surface states play an important role in the magnetization dynamics of YIG. Temperature-dependent ferromagnetic resonance of Bi₂Se₃/YIG reveals signatures of the magnetic proximity effect of T_C as high as 180 K, an emerging low-temperature perpendicular magnetic anisotropy competing the high-temperature IMA, and an increasing exchange effective field of YIG steadily increasing toward low temperature. Our study sheds light on the effects of topological insulators on magnetization dynamics, essential for the development of topological insulator-based spintronic devices.

Understanding the effects of topological insulators on magnetization dynamics of adjacent magnetic materials is essential for novel spintronic devices. Here, Fanchiang et al. report thickness dependence of interfacial in-plane magnetic anisotropy and damping enhancement in Bi₂Se₃/yttrium iron garnet (YIG) bilayers, indicating an important role of topological surface states in the magnetization dynamics of YIG.

Contribution of Matrix Metallopeptidase-1 Genotypes, Smoking, Alcohol Drinking and Areca Chewing to Nasopharyngeal Carcinoma Susceptibility

BACKGROUND/AIM

The up-regulation of matrix metalloproteinase-1 (MMP-1) has been demonstrated to be correlated with lymph node metastasis of nasopharyngeal carcinoma (NPC); however, the genotypic role of MMP-1 is not well understand. The present study aimed to assess the contribution of MMP-1 promoter -1607 genotypes, combined with environmental carcinogens, on the predisposition to NPC tumorigenesis.

MATERIALS AND METHODS

The MMP-1 promoter -1607 genotypes were examined for 352 age- and gender-matched controls and 176 NPC patients by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methodology.

RESULTS

We found that the MMP-1 promoter -1607 heterozygous 1G/2G and homozygous 1G/1G genotypes, were more and more prone to be associated with NPC risk (odds ratio (OR)=0.64 and 0.63, 95% confidence interval (CI)=0.43-1.03 and 0.36-0.96, p=0.0659 and 0.0932, respectively). In the dominant models, there was a significant association between the genotype of MMP-1 promoter -1607 and NPC risk (OR=0.64, 95% CI=0.43-0.91, p=0.0359). In addition, individuals carrying the 1G allele at MMP-1 promoter -1607 were less susceptible to NPC (OR=0.73; 95%CI=0.59 to 0.96, p=0.0418) after adjustment for age, gender, cigarette, alcohol and areca consumption.

CONCLUSION

The 1G/1G genotype of MMP-1 promoter -1607 may independently have a protective effect on NPC risk, without interaction with behavioral factors, including cigarette, alcohol and areca consumption.

Contribution of DNA Repair Xeroderma Pigmentosum Group D Genotypes to Colorectal Cancer Risk in Taiwan

BACKGROUND/AIM

It has been previously proposed that genetic variations on DNA repair genes confer susceptibility to cancer and the DNA repair gene Xeroderma Pigmentosum Group D (XPD) is thought to play the role of a helicase during excision repair and transcription. We investigated three genotypes of XPD, at promoter -114 (rs3810366), Asp312Asn (rs1799793) and Lys751Gln (rs13181), regarding their association with colorectal cancer susceptibility in a Taiwanese population.

MATERIALS AND METHODS

In total, 362 patients with colorectal cancer and 362 gender- and age-matched healthy controls were genotyped by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP), and their XPD genotypes' association with colorectal cancer risk was investigated.

RESULTS

The genotypes of XPD Asp312Asn (p=0.2493), Lys751Gln (p=0.7547) and promoter -114 (p=0.8702), were not associated with susceptibility for colorectal cancer. The Chi-square test revealed that the variant alleles of XPD Asp312Asn, Lys751Gln and promoter -114 was not associated with susceptibility for colorectal cancer either [p=0.1330, 0.3888 and 0.8740; odds ratio (OR)=1.20, 0.83 and 0.98; 95% confidence interval (95%CI)=0.95-1.52, 0.54-1.27 and 0.80-1.21, respectively]. The risk of A/G and A/A genotypes have no association with cancer risk among non-alcohol drinkers (OR=1.24, 95%, CI=0.90-1.72, p=0.2103) or alcohol drinkers (OR=1.51, 95% CI=0.64-3.55, p=0.4648). There exists no obvious contribution of XPD genotypes to tumor size (p=0.3531), location (p=0.3006) and lymph node metastasis (p=0.1061).

CONCLUSION

Asp312Asn, Lys751Gln and promoter -114 of the XPD gene were not found to be adequate predictive markers for colorectal cancer risk in Taiwan.

Genomic analysis of Staphylococcus phage Stau2 isolated from medical specimen

Stau2 is a lytic myophage of Staphylococcus aureus isolated from medical specimen. Exhibiting a broad host range against S. aureus clinical isolates, Stau2 is potentially useful for topical phage therapy or as an additive in food preservation. In this study, Stau2 was firstly revealed to possess a circularly permuted linear genome of 133,798 bp, with low G + C content, containing 146 open reading frames, but encoding no tRNA. The genome is organized into several modules containing genes for packaging, structural proteins, replication/transcription and host-cell-lysis, with the structural proteins and DNA polymerase modules being organized similarly to that in Twort-like phages of Staphylococcus. With the encoded DNA replication genes, Stau2 can possibly use its own system for replication. In addition, analysis in silico found several introns in seven genes, including those involved in DNA metabolism, packaging, and structure, while one of them (helicase gene) is experimentally confirmed to undergo splicing. Furthermore, phylogenetic analysis suggested Stau2 to be most closely related to Staphylococcus phages SA11 and Remus, members of Twort-like phages. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis showed 14 structural proteins of Stau2 and N-terminal sequencing identified three of them. Importantly, this phage does not encode any proteins which are known or suspected to be involved in toxicity, pathogenicity, or antibiotic resistance. Therefore, further investigations of feasible therapeutic application of Stau2 are needed.

Tumor Necrosis Factor-α Genotypes Are Associated with Hepatocellular Carcinoma Risk in Taiwanese Males, Smokers and Alcohol Drinkers

AIM

Hepatocellular carcinoma (HCC), the fifth most common cancer worldwide, has high prevalence and mortality rates in Taiwan. Tumor necrosis factor-α (TNFα), an important proinflammatory cytokine, is involved in multiple physiological and pathogenic phenomena that lead to the destruction and dysregulation of tissues. The present study aimed to evaluate the contribution of TNFA genotype, together with cigarette smoking and alcohol drinking lifestyle to the risk of HCC.

MATERIALS AND METHODS

In this hospital-based case-control study, association of TNFA single-nucleotide polymorphisms -1031T/C, -863C/A, -857T/C, -308G/A and +489A/G, with HCC risk were examined in 298 patients with HCC and 889 age- and gender-matched healthy controls.

RESULTS

The percentages of AA, AG and GG TNFA -308G/A were 6.4%, 18.1% and 75.5% in the HCC patient group and 2.0%, 16.0% and 82.0% in the non-cancer control group, respectively. The AA and AG genotypes were associated with 3.42- and 1.23-fold higher odds of HCC than the GG genotype (95% confidence interval=1.76-6.63 and 0.87-1.74, respectively). No such significant difference was found for other polymorphic sites. We further stratified the populations by gender, cigarette smoking and alcohol drinking status to investigate their combined contributions with TNFA -308G/A genotype to HCC risk. The results showed that the AA and AG genotypes of TNFA -308G/A increased HCC susceptibility which was obvious among males, smokers, and alcohol drinkers, but not females, non-smokers, or non-drinkers (p=0.0003, 0.0003, 0.0014, 0.6127, 0.7442 and 0.3010, respectively).

CONCLUSION

Our results suggest that the AA and AG polymorphism of TNFA -308G/A genotypes associated with HCC risk in Taiwan, particularly among males, smokers and alcohol drinkers.

The therapeutic effect of rosuvastatin on cardiac remodelling from hypertrophy to fibrosis during the end-stage hypertension in rats

End-stage hypertensive heart disease is an increasing cause of cardiac mortality. Therefore, the current study focused on the cardiac remodelling from hypertrophy to fibrosis in old-aged spontaneously hypertensive rats (SHRs), and explored the therapeutic effects of Rosuvastatin and its possible mechanism(s) of action. Spontaneously hypertensive rats at age 52 weeks were randomly divided into three groups, the first two to receive Rosuvastatin at a dose of 20 mg/kg/day and 40 mg/kg/day, respectively, and the third to receive placebo, which was to be compared with Wistar-Kyoto as controls. After 2-month treatment, SBP, heart to body weight ratio (HW/BW%) and echocardiographic features were evaluated, followed by haematoxylin and eosin and Masson trichrome staining in conjunction with qPCR of foetal gene expressions. Transferase-mediated dUTP nick-end labelling assay and immunofluorescent labelling for active caspase-3 were used to detect the apoptotic cardiomyocytes. Signaling pathways involved were examined by using western blot. Old-aged SHR developed end-stage hypertensive heart disease characterized by significant enhancement of HW/BW%, LVAWd and LVPWd, and decreased LVEF and LVFS, accompanied by cardiomyocytes enlargement and fibrosis along with activation of foetal gene programme. Cardiac apoptosis increased significantly during the transition process. Rosuvastatin reduced hypertrophy significantly via AT₁ Receptor-PKCβ2/α-ERK-c-fos pathway; protected myocardium against apoptosis via Akt-FOXO1, Bcl-2 family and survivin pathways and consequently suppressed the caspase-3 activity. The present study revealed that old-aged SHRs developed cardiac remodelling from hypertrophy to fibrosis via cardiac apoptosis during the end stage of hypertensive heart disease. These pathological changes might be the consequence of activation of AT₁ Receptor-PKCβ2/α-ERK-c-fos and AKT-FOXO1/Bcl-2/survivin/Caspase3 signaling. Rosuvastatin effectively attenuated the structural changes by reversing the signaling transductions involved.

Predictive role of XRCC5/XRCC6 genotypes in digestive system cancers

Cancers are a worldwide concern; oral, esophageal and gastrointestinal cancers represent important causes of cancer-related mortality and contribute to a significant burden of human health. The DNA repair systems are the genome caretakers, playing a critical role in the initiation and progression of cancers. However, the association between the genomic variations of DNA repair genes and cancer susceptibility is not well understood. This review focuses on the polymorphic genotypes of the non-homologous end-joining DNA repair system, highlighting the role of two genes of this pathway, XRCC5 and XRCC6, in the susceptibility to digestive system cancers and discussing their potential contributions to personalized medicine.

Role of the XRCC5/XRCC6 dimer in carcinogenesis and pharmacogenomics

Over the past few decades, the incidence of cancer has rapidly increased all over the world and cancer remains a major threat to public health. It is believed that cancer results from a series of genetic alterations that lead to the progressive disorder of the normal mechanisms controlling cell proliferation, differentiation, death and/or genomic stability. The response of the cell to genetic injury and its ability to maintain genomic stability by means of a variety of DNA repair mechanisms are therefore essential in preventing tumor initiation and progression. From the same viewpoint, the relative role of DNA repair as a biomarker for prognosis, predictor of drug and therapy responses or indeed as a target for novel gene therapy, is very promising. In this article, we have summarized the studies investigating the association between the XRCC5/XRCC6 dimer and the susceptibility to multiple cancers and discuss its role in carcinogenesis and its potential application to anticancer drug discovery.

Synergistic cytotoxic effects of arsenic trioxide plus dithiothreitol on mice oral cancer cells

The anti-tumor properties of arsenic trioxide have attracted extensive attention after successfully inducing apoptosis of acute promyelocytic leukemia cells. However, the therapeutic spectrum should not only be restricted to acute promyelocytic leukemia, but should also extend into other types of tumor cells. In this study, we aimed at investigating its potential application to clinical therapeutics in oral cancer. In this preclinical animal test, primarily cultured cells from the tumor sites and normal sites of a two-drug (200 μg/ml 4-nitroquinoline 1-oxide (4NQO) plus 500 μg/ml arecoline)-induced oral cancer C57BL/6J Narl mice model were examined for their viabilities after treatments of arsenic trioxide with/without other drugs. In this model, the mice were treated with 4NQO plus arecoline (NA) in their drinking water for eight weeks (8-w), and the drugs were withdrawn for another 10 or 20 weeks (18-w and 28-w, respectively). The results showed that 2 μM of arsenic trioxide 24-h treatment suppressed the viabilities of cells primarily cultured from the tumor sites of 8-w, 18-w and 28-w NA-treated mice to 72.9%, 71.5% and 65.6%. However, it also suppressed the viabilities of cells from the sham-treated mice of 8-w, 18-w and 28-w to 76.8%, 73.4% and 75.7%, respectively. Therefore, 0.5 μM of arsenic trioxide treatment for 24 h, which suppressed the viabilities of cells primarily cultured from the tumor sites of 28-w NA-treated and sham-treated mice to 15.6% and 9.1%, was examined for its synergistic effects on the two primarily cultured cell lines with other drugs. The results showed that 10-20 μM dithiothreitol enhanced the cytotoxic effects of arsenic trioxide to 43.3~62.1%, better than those of 4 J/m(2) UVC, 20 μM H(2)O(2) or 100 μM buthionine sulfoximine (21.3%, 13.2%, and 14.2%, respectively). At the same time, 10-20 μM dithiothreitol plus 0.5 μM arsenic trioxide treatments caused only 12.3% and 15.2% of cell death in the control group. The cytotoxicity of dithiothreitol and arsenic trioxide combination on primarily cultured cells from this oral cancer model should be confirmed in human oral cancer cell lines before its application in clinical therapy, and the detailed mechanism is worth further investigation.

Colorectal cancer and genetic polymorphism of DNA double-strand break repair gene XRCC4 in Taiwan

The DNA repair gene X-ray repair complementing defective repair in Chinese hamster cells 4 (XRCC4) is thought to play a major role in the caretaking of the whole genome via double-strand break repair. However, the association of polymorphic variants of XRCC4 with colorectal cancer susceptibility has never been reported. In this hospital-based case-control study, the association of XRCC4 polymorphisms C-1622T (rs7727691), G-1394T (rs6869366), G-652T (rs2075685), C-571T (rs2075686), intron 3 DIP (rs28360071), S247A (rs3734091) and intron 7 DIP (rs28360317) with colorectal cancer risk in a Taiwanese population was investigated. The genotypes of XRCC4 of 370 patients with colorectal cancer and 370 age- and gender-matched healthy controls were determined by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. We found significant differences in the genetic and allelic frequencies of the XRCC4 G-1394T between the colorectal cancer and control groups (p=0.0003 and 8.32 x 10(-5), respectively). The distributions of other genetic polymorphisms between cases and the control group were not significantly different. We conclude that the G allele of XRCC4 G-1394T may contribute to colorectal carcinogenesis and may be useful for early detection of colorectal cancer.

Significant association of Ku80 single nucleotide polymorphisms with colorectal cancer susceptibility in Central Taiwan

AIM

To evaluate the association between the polymorphisms of the Ku80 gene and the risk of colorectal cancer in Central Taiwan.

MATERIALS AND METHODS

In this hospital-based case-control study, the association of Ku80 G-1401T rs828907, Ku80 C-319T rs11685387 and Ku80 intron 19 rs9288518 polymorphisms with colorectal cancer risk in a central Taiwanese population was investigated. In total, 362 patients with colorectal cancer and 362 age- and gender-matched healthy controls recruited from the China Medical Hospital in central Taiwan were genotyped.

RESULTS

A significantly different distribution was found in the frequency of the Ku80 G-1401T genotype, but not the Ku80 C-319T or intron 19 genotypes, between the colorectal cancer and control groups. The T allele Ku80 G-1401T conferred a significantly (p=0.0069) increased risk of colorectal cancer. As for Ku80 C-319T and intron 19 polymorphisms, there was no difference in distribution between the colorectal cancer and control groups. Gene interactions with smoking, but not with alcohol consumption, were significant for Ku80 G-1401T polymorphism. The Ku80 G-1401T GT and TT genotype in association with smoking conferred an increased risk of 2.537 (95% confidence interval=1.398-4.601) for colorectal cancer.

CONCLUSION

These results provide the first evidence that the T allele of the Ku80 G-1401T may be associated with the development of colorectal cancer and may be a novel useful marker for primary prevention and anticancer intervention.

A two-method meta-analysis of Neuregulin 1(NRG1) association and heterogeneity in schizophrenia

NRG1 is one of the most researched genes associated with schizophrenia. Although three meta-analyses in this area have been published, the results have been inconclusive and even conflicting. Family based studies can be problematical due to the difficulty of synthesizing them with case-control studies. Heterogeneity is another persistently difficult problem which tends to be side-stepped in genetic studies. To deal with these points, we performed a meta-analysis of 26 published case-control and family-based association studies up to September 2008 covering 8049 cases, 8869 controls and 1515 families. The matrix of coancestry coefficient was also calculated using population genetics. Across these studies, the conclusions are as follows: Firstly, only SNP8NRG221132, 420M9-1395(0) and 478B14-848(0) showed significant association in the relatively small sample size. Secondly, we applied both Kazeem's and Lohmueller's methods for synthesizing family and case control studies and there was no statistically significant difference between the results from the two methods, suggesting that either method can be used. In addition, the association analysis of case-control studies was statistically consistent with that of family studies. Finally, the matrix of coancestry coefficient suggested obvious population stratification. The study reveals that one SNP of the NRG1 gene does not contribute significantly to schizophrenia and that population stratification is evident. In future genetic association analysis on complex psychic diseases, haplotype blocks and population structure should be given greater consideration.

The role of XRCC4 in carcinogenesis and anticancer drug discovery

In the past decades, the incidence of cancer keeps its rapid increasing step all over the world and cancer is always an important threat to public health. It is believed that cancer is resulted from a series of genetic alterations leading to progressive disorder of the normal mechanisms controlling cell proliferation, differentiation, death, and/or genomic stability. The response of the cell to genetic injury and its ability to maintain genomic stability by means of a variety of DNA repair mechanisms are therefore essential in preventing tumor initiation and progression. From the same viewpoint, the relative role of DNA repair as a biomarker for prognosis, predicator of drug and therapy responses, or indeed as target for novel gene therapy is recently patented and very promising. In this review, we have summarized the studies investigating the association between XRCC4, one of the NHEJ genes, and the susceptibility to multiple cancers, and discussed its role in carcinogenesis and application in anticancer drug discovery.

Oral cancer and genetic polymorphism of DNA double strand break gene Ku70 in Taiwan

The DNA repair gene Ku70, an important caretaker of the overall genome stability, is thought to play a major role in the DNA double strand break repair system. It is known that defects in double strand break repair capacity can lead to irreversible genomic instability. However, the polymorphic variants of Ku70 and their association with oral cancer susceptibility has never been reported on. In this hospital-based case-control study, the association of Ku70 promoter T-991C (rs5751129), promoter G-57C (rs2267437), promoter A-31G (rs132770), and intron3 (rs132774) polymorphisms with oral cancer risk in a Taiwanese population was investigated. In total, 318 patients with oral cancer and 318 age- and gender-matched healthy controls recruited from the China Medical Hospital in Taiwan were genotyped. The results showed that there were significant differences between the oral cancer and control groups in the distribution of their genotypes (P=0.0031) and allelic frequency (P=0.0009) in the Ku70 promoter T-991C polymorphism. Individuals who carried at least one C allele (T/C or C/C) had a 2.15-fold increased risk of developing oral cancer compared to those who carried the T/T wild-type genotype (95% CI: 1.37-3.36). In the other three polymorphisms, there was no difference between both groups in the distribution of either genotype or allelic frequency. In conclusion, the Ku70 promoter T-991C, but not the Ku70 promoter C-57G, promoter A-31G or intron3, is connected to oral cancer susceptibility. This polymorphism may be a novel useful marker for primary prevention and anticancer intervention.

Rapid and sensitive detection of Taura syndrome virus using nucleic acid-based amplification

Requiring only simple heating devices, isothermal nucleic acid-based amplification (NASBA) is a potential detection platform to be developed for on-site diagnosis of aquaculture pathogens. In this report, an NASBA assay has been developed for the Taura syndrome virus (TSV), one of the most devastating RNA virus pathogens for several penaeid shrimp species. The NASBA amplicons were detected by agarose gel electrophoresis and confirmed by Northern-blotting and dot-blotting analysis, using a biotinylated TSV-specific primer. The sensitivity of the TSV NASBA coupled with dot-blotting detection was approximately 5-fold less sensitive than that of the commercially available RT-nested, PCR-based IQ2000 TSV Detection and Prevention System that was also confirmed to be more sensitive than the RT-PCR-based TSV detection protocol recommended by the OIE (Office International des Epizooties). The specificity of the TSV NASBA reaction was substantiated by the results that RNA of non-target viruses did not generate any signals. Furthermore, a simple colorimetric microtiter plate assay employing TSV-specific capture and detection primers was developed as a simple alternative approach for the detection of NASBA amplicons. Taken together, the combination of the isothermal NASBA and colorimetric solid phase-based assays should allow sensitive, straightforward, and speedy on-site detection of TSV.

Mutations at KFRDI and VGK domains of enterovirus 71 3C protease affect its RNA binding and proteolytic activities

The 3C protease (3C(pro)) of enterovirus 71 (EV71) is a good molecular target for drug discovery. Notably, this protease was found to possess RNA-binding activity. The regions responsible for RNA binding were classified as 'KFRDI' (positions 82-86) and 'VGK' (positions 154-156) in 3C(pro) by mutagenesis study. Although the RNA-binding regions are structurally distinct from the catalytic site of EV71 3C(pro), mutations in the RNA-binding regions influenced 3C(pro) proteolytic activity. In contrast, mutations at the catalytic site had almost no influence on RNA binding ability. We identified certain mutations within 3C(pro) which abrogated both the RNA-binding activity of the expressed, recombinant, protease and the ability to rescue virus from an infectious full-length clone of EV71 (pEV71). Interestingly, mutation at position 84 from Arg(R) to Lys(K) was found to retain good RNA binding and proteolytic activity for the recombinant 3C(pro); however, no virus could be rescued when pEV71 with the R84K mutation was introduced into the infectious copy. Together, these results may provide useful information for using 3C(pro) as the molecular target to develop anti-EV71 agents.

Characterization of a Vero cell-adapted virulent strain of enterovirus 71 suitable for use as a vaccine candidate

Enterovirus 71 (EV71) is a neurotrophic virus that causes seasonal morbidity and mortality in children throughout the world with increasing frequency in recent years. Because of the lack of an effective antiviral agent, primary prevention, including the development of effective vaccines, is a top priority in terms of control strategies. Poliovirus vaccine technology, both live attenuated and inactivated, killed virus vaccines, can be adopted for use with EV71 because of their relatedness. In this study, we have characterized a laboratory-adapted EV71 strain, YN3-4a, which exhibits different characteristics from those of its parent isolate, neu, in having a rapid growth rate in Vero cells, a larger plaque size, and a lower LD(50) in newborn mice. The YN3-4a can be produced at a high viral titer of up to 10(10) tissue culture infective dose (TCID(50)) when grown in Vero cells, an approved substrate for virus vaccine production. Mouse antiserum raised against YN3-4a can neutralize a broad range of strains of EV71 isolated at different times from a variety of geographic regions. On passage in Vero cells, YN3-4a remained genetically and phenotypically stable. Many of the above-described features, such as high viral yield, strong immunogenicity, broad-based antigenic coverage, and passage stability, are desirable features in a prototype virus for the development of an inactivated viral vaccine.

Protection against lethal enterovirus 71 infection in newborn mice by passive immunization with subunit VP1 vaccines and inactivated virus

Enterovirus 71 (EV71), the newest member of Enteroviridae, is notable for its etiological role in epidemics of severe neurological diseases in children. Developing effective vaccines is considered a top choice among all control measures. We compared the inactivated virus vaccine (10 microg protein/mouse) with subunit vaccines--VP1 DNA vaccine (100 microg/mouse) or recombinant VP1 protein (10 microg/mouse)--in its ability to elicit maternal antibody and to provide protection against lethal infection of EV71 in suckling mice. Prior to gestation, all three groups of vaccinated dams possessed similar levels of neutralizing antibody. With a challenge dose of 2300 LD(50) virus/mouse, suckling mice born to dams immunized with inactivated virus showed 80% survival. The subunit vaccines provided protection only at a lower challenge dosage of 230 LD(50) per mouse, with 40% survival for DNA vaccine and 80% survival for VP1 protein. The cytokine profile produced by splenocytes showed a high level of IL-4 in the inactivated virus group, high levels of IFN-gamma and IL-12 in the DNA vaccine group, and high levels of IL-10 and IFN-gamma in the VP1 protein group. Overall, the inactivated virus elicited a much greater magnitude of immune response than the subunit vaccines, including total IgG, all four IgG subtypes, and T-helper-cell responses; these antibodies were shown to be protective against lethal infection when passively transferred to susceptible newborn mice. Our data indicated that inactivated virus is the choice of vaccine preparation capable of fulfilling the demand for effective control, and that VP1 subunit vaccines remain promising vaccine strategies that require further refinement.

Genetic analysis of enterovirus 71 isolated from fatal and non-fatal cases of hand, foot and mouth disease during an epidemic in Taiwan, 1998

A large scale outbreak of hand-foot-and-mouth disease (HFMD) occurred in Taiwan in 1998, in which more than 80 children died of shock syndrome with pulmonary edema/hemorrhage. Enterovirus 71 was implicated as the cause of this outbreak. In order to understand the virological basis responsible for mortality on this scale, nucleotide sequences of VP1 that is important for serotypic specificity, and the 5'-non-coding region (5'-NCR) that is important for replication efficiency, were analyzed comparatively. Phylogenetic analysis of both VP1 and 5'-NCR of nine EV71 isolates derived from specimens of fatal patients and seven isolates derived from uncomplicated HFMD patients showed that all but one isolate fell into genotype B. The one distinct isolate from a case of uncomplicated HFMD belonged to genotype C that was clustered along with one isolate from Taiwan in 1986. Complete sequence analysis of two selected isolates, one from the spinal cord of a fatal case and one from the vesicle fluid of a patient with mild HFMD, confirmed a high degree (97-100%) of identity in nucleotide sequence throughout the entire genome, except focal regions of 3C and 3'-NCR where the nucleotide homology was 90-91%. The identity of the deduced amino acid sequence in the 3C region that encodes viral proteinase dropped further to 86%, a result of missense mutations at the first nucleotide position of many codons.

Comparison of intravenous dipyridamole and adenosine Tc-99m MIBI myocardial imaging for detection of coronary artery disease

A total of 44 patients referred for Tc-99m MIBI myocardial imaging for detection of coronary artery disease (CAD) were studied to compare the differences in heart beat, blood pressure, electrocardiographic changes and side effects during intravenous infusion of dipyridamole (ID) and adenosine (IA) and also to determine the degree of concordance between ID and IA Tc-99m MIBI imaging. These patients were divided into two groups: 20 suspected CAD patients constituted group I and 24 proven CAD patients formed group II. All patients received ID 0.56 mg/kg for 4 min and within about 10 days IA 0.14 microgram/kg/min for 6 min with Tc-99m MIBI imaging. The results revealed that maximal heart beat increased and maximal systolic blood pressure decreased in both IA and ID patients with no statistically significant differences. Transient second-degree AV block occurred with IA in 3 patients. Side effects, such as, chest pain, headache, dizziness and shortness of breath occurred more often and were in general more intense in IA patients, but they were typically mild and resolved spontaneously within 1 or 2 min of discontinuation of IA. Both IA and ID Tc-99m MIBI imaging were normal in 18 of 20 group I patients and were concordant for the presence of perfusion defects in the other 2 patients. Of 24 group II patients, all had myocardial perfusion defects on both tests and were concordant for the severity of the perfusion abnormalities. However, in other 2 patients. Of 24 group II patients, all had myocardial perfusion defects on both tests and were concordant for the severity of the perfusion abnormalities.(ABSTRACT TRUNCATED AT 250 WORDS)