Prevalence of Metabolically Healthy Obese and Metabolically Obese but Normal Weight in Adults Worldwide: A Meta-Analysis

The objective of the present study was to summarize the prevalence and influencing factors of metabolically healthy obese (MHO) and metabolically obese but normal weight (MONW) among people ≥ 18 years old in the general population worldwide. We searched for studies of the prevalence of MHO and MONW published in English and Chinese up to October 2013. Pooled prevalence estimates were calculated by a random-effects model according to a Q test. The effects of gender, region, age, sample size, smoking, and alcohol consumption on MHO and MONW were analyzed. Differences between subgroups were assessed by chi-square test. Publication bias was estimated by Egger's test. Studies of MHO and MONW showed heterogeneity (I(2)=99.4% and I(2)=99.7%, respectively). The overall prevalence of MHO and MONW was 7.27% (95% CI 5.92-8.90%) and 19.98% (95% CI 16.54-23.94%), respectively. American populations had the highest MHO prevalence and European populations the highest MONW prevalence. Different patterns of MHO and MONW were observed in the subgroup analysis with respect to gender, age, sample size, smoking, alcohol consumption, and metabolically healthy criteria. The prevalence of both MHO and MONW were affected by gender, region, age, sample size, smoking, alcohol consumption, and metabolically healthy criteria, but studies showed high heterogeneity.

Comparative proteomic analysis reveals mite (Varroa destructor) resistance-related proteins in Eastern honeybees (Apis cerana)

The mite (Varroa destructor) has become the greatest threat to apiculture worldwide. As the original host of the mite, Apis cerana can effectively resist the mite. An increased understanding of the resistance mechanisms of Eastern honeybees against V. destructor may help researchers to protect other species against these parasites. In this study, the proteomes of 4 Apis cerana colonies were analyzed using an isobaric tag for relative and absolute quantitation technology. We determined the differences in gene and protein expression between susceptible and resistant colonies that were either unchallenged or challenged by V. destructor. The results showed that a total of 1532 proteins were identified. Gene Ontology enrichment analysis suggested that the transcription factors and basic metabolic and respiratory processes were efficient and feasible factors controlling this resistance, and 12 differentially expressed proteins were identified in Venn analysis. The results were validated by quantitative polymerase chain reaction. This study may provide insight into the genetic mechanisms underlying the resistance of honeybee to mites.

Synthesis and biomedical applications of functional poly(α-hydroxy acids) via ring-opening polymerization of O-carboxyanhydrides

Poly(α-hydroxy acids) (PAHAs) are a class of biodegradable and biocompatible polymers that are widely used in numerous applications. One drawback of these conventional polymers, however, is their lack of side-chain functionalities, which makes it difficult to conjugate active moieties to PAHA or to fine-tune the physical and chemical properties of PAHA-derived materials through side-chain modifications. Thus, extensive efforts have been devoted to the development of methodology that allows facile preparation of PAHAs with controlled molecular weights and a variety of functionalities for widespread utilities. However, it is highly challenging to introduce functional groups into conventional PAHAs derived from ring-opening polymerization (ROP) of lactides and glycolides to yield functional PAHAs with favorable properties, such as tunable hydrophilicity/hydrophobicity, facile postpolymerization modification, and well-defined physicochemical properties. Amino acids are excellent resources for functional polymers because of their low cost, availability, and structural as well as stereochemical diversity. Nevertheless, the synthesis of functional PAHAs using amino acids as building blocks has been rarely reported because of the difficulty of preparing large-scale monomers and poor yields during the synthesis. The synthesis of functionalized PAHAs from O-carboxyanhydrides (OCAs), a class of five-membered cyclic anhydrides derived from amino acids, has proven to be one of the most promising strategies and has thus attracted tremendous interest recently. In this Account, we highlight the recent progress in our group on the synthesis of functional PAHAs via ROP of OCAs and their self-assembly and biomedical applications. New synthetic methodologies that allow the facile preparation of PAHAs with controlled molecular weights and various functionalities through ROP of OCAs are reviewed and evaluated. The in vivo stability, side-chain functionalities, and/or trigger responsiveness of several functional PAHAs are evaluated. Their biomedical applications in drug and gene delivery are also discussed. The ready availability of starting materials from renewable resources and the facile postmodification strategies such as azide-alkyne cycloaddition and the thiol-yne "click" reaction have enabled the production of a multitude of PAHAs with controlled molecular weights, narrow polydispersity, high terminal group fidelities, and structural diversities that are amenable for self-assembly and bioapplications. We anticipate that this new generation of PAHAs and their self-assembled nanosystems as biomaterials will open up exciting new opportunities and have widespread utilities for biological applications.

Effect of γ-Aminobutyric Acid-producing Lactobacillus Strain on Laying Performance, Egg Quality and Serum Enzyme Activity in Hy-Line Brown Hens under Heat Stress

Heat-stress remains a costly issue for animal production, especially for poultry as they lack sweat glands, and alleviating heat-stress is necessary for ensuring animal production in hot environment. A high γ-aminobutyric acid (GABA)-producer Lactobacillus strain was used to investigate the effect of dietary GABA-producer on laying performance and egg quality in heat-stressed Hy-line brown hens. Hy-Line brown hens (n = 1,164) at 280 days of age were randomly divided into 4 groups based on the amount of freeze-dried GABA-producer added to the basal diet as follows: i) 0 mg/kg, ii) 25 mg/kg, iii) 50 mg/kg, and iv) 100 mg/kg. All hens were subjected to heat-stress treatment through maintaining the temperature and the relative humidity at 28.83±3.85°C and 37% to 53.9%, respectively. During the experiment, laying rate, egg weight and feed intake of hens were recorded daily. At the 30th and 60th day after the start of the experiment, biochemical parameters, enzyme activity and immune activity in serum were measured. Egg production, average egg weight, average daily feed intake, feed conversion ratio and percentage of speckled egg, soft shell egg and misshaped egg were significantly improved (p<0.05) by the increasing supplementation of the dietary GABA-producer. Shape index, eggshell thickness, strength and weight were increased linearly with increasing GABA-producer supplementation. The level of calcium, phosphorus, glucose, total protein and albumin in serum of the hens fed GABA-producing strain supplemented diet was significantly higher (p<0.05) than that of the hens fed the basal diet, whereas cholesterol level was decreased. Compared with the basal diet, GABA-producer strain supplementation increased serum level of glutathione peroxidase (p = 0.009) and superoxide dismutase. In conclusion, GABA-producer played an important role in alleviating heat-stress, the isolated GABA-producer strain might be a potential natural and safe probiotic to use to improve laying performance and egg quality in heat-stressed hens.

Relationship between genetic polymorphisms of DNA ligase 1 and non-small cell lung cancer susceptibility and radiosensitivity

The aim of this study was to examine the relationship between genetic polymorphisms in DNA ligase 1 (LIG1) and non-small cell lung cancer (NSCLC) susceptibility and radiosensitivity in a Chinese population. This was a case-control study that included 352 NSCLC patients and 448 healthy controls. Polymerase chain reaction-restriction fragment length polymorphism analysis was conducted to detect HaeIII polymorphisms in exon 6 of the LIG1 gene in this popula-tion. This information was used to observe the effects of radiation in pa-tients with different genotypes in order to determine the genotypes as-sociated with radiosensitivity. The CC genotype and C allele frequency were significantly higher in the NSCLC group than in the control group (P = 0.012 and P = 0.023, respectively). The relative risk of experienc-ing NSCLC was 2.55 [95% confidence interval (CI), 1.12-3.98] for CC homozygous patients and 0.87 (95%CI, 0.46-1.88) for AA homozygous patients. Analysis of LIG1 genetic polymorphisms and radiosensitiv-ity of NSCLC patients showed that AA homozygous patients were sig-nificantly more radiosensitive than the control group (AA vs AC, P = 0.014; AA vs CC, P < 0.001; AC vs CC, P = 0.023). Therefore, the LIG1 CC genotype was associated with susceptibility to NSCLC, and the AA genotype demonstrated increased radiosensitivity compared to the AC and CC genotypes.

Diagnostic value of aberrant gene methylation in stool samples for colorectal cancer or adenomas: a meta-analysis

AIM

Many studies have reported detection of aberrant methylation of genes in stool sample for early colorectal cancer (CRC) or adenomas had high sensitivity and specificity, but still remained controversial. We aimed to evaluate the diagnostic value of stool testing for markers of CRC and adenomas.

METHODS

Medline, EMbase, Web of Science, the Cochrane Library, and EMbase were systematically searched. Meta-analysis was performed using a random effects model with sensitivity, specificity, diagnostic OR (DOR), area under the summary ROC curves (SROC) and their 95% confidence interval (95% CI).

RESULTS

A total of 13 studies including 716 patients with CRC 220 cases of adenoma and 414 healthy controls were eligible for final analysis. The sensitivity, specificity, positive likelihood ratio, negative likelihood ratio, and DOR for the detection of CRC were 0.78 (95% CI: 0.75-0.82), 0.90 (95% CI: 0.91-0.96), 9.612 (95% CI: 6.761-13.666), 0.243 (95% CI: 0.176-0.336), and 48.21 (95% CI: 28.24-82.30), respectively. The sensitivity and specificity for the detection of adenoma were 0.63 (95% CI: 0.56-0.69) and 0.93 (95% CI: 0.90-0.96), respectively. The area under the SROC curve was 0.9438 and 0.9385 in CRC and adenoma detection, respectively.

CONCLUSION

Fecal gene methylation testing as a noninvasive method can be used as a screening measurement for CRC or colorectal adenoma with high sensitivity and specificity.

Optimization of multifunctional chitosan-siRNA nanoparticles for oral delivery applications, targeting TNF-α silencing in rats

Secretion of tumor necrosis factor-α (TNF-α) by macrophages plays a predominant role in the development and progression of various inflammatory diseases. In the current contribution, multifunctional nanoparticles (NPs) containing TNF-α siRNA targeting macrophages via oral administration were developed to knockdown TNF-α expression against acute hepatic injury in rats. Mannose-modified trimethyl chitosan-cysteine (MTC) NPs were prepared by self-assembly method (sa-MTC NPs), ionic gelation and siRNA entrapment method (en-MTC NPs), and ionic gelation and siRNA adsorption method (ad-MTC NPs). Among them, en-MTC NPs demonstrated the best stability against ionic challenges with desired siRNA integrity against nucleases. By targeting normal enterocytes and M cells that express mannose receptors, en-MTC NPs notably promoted intestinal absorption of siRNA in rats. They further facilitated siRNA internalization by rat peritoneal exudate cells (PECs) via lipid-raft involved endocytosis and macropinocytosis, thus inducing effective in vitro TNF-α knockdown. Orally delivered en-MTC NPs at a low siRNA dose of 50 μg/kg inhibited systemic TNF-α production and decreased TNF-α mRNA levels in macrophage-enriched liver, spleen, and lung tissues, which consequently protected rats from acute hepatic injury. Therefore, the en-MTC NPs would provide an effective approach to orally deliver TNF-α siRNA for the anti-inflammatory therapy.

The Kinematics and Kinetics Analysis of the Lower Extremity in the Landing Phase of a Stop-jump Task

Large number of studies showed that landing with great impact forces may be a risk factor for knee injuries. The purpose of this study was to illustrate the different landing loads to lower extremity of both genders and examine the relationships among selected lower extremity kinematics and kinetics during the landing of a stop-jump task. A total of 35 male and 35 female healthy subjects were recruited in this study. Each subject executed five experiment actions. Lower extremity kinematics and kinetics were synchronously acquired. The comparison of lower extremity kinematics for different genders showed significant difference. The knee and hip maximum flexion angle, peak ground reaction force and peak knee extension moment have significantly decreased during the landing of the stop-jump task among the female subjects. The hip flexion angle at the initial foot contact phase showed significant correlation with peak ground reaction force during landing of the stop-jump task (r=-0.927, p<0.001). The knee flexion angle at the initial foot contact phase had significant correlation with peak ground reaction force and vertical ground reaction forces during landing of the stop-jump task (r=-0.908, p<0.001; r=0.812, P=0.002). A large hip and knee flexion angles at the initial foot contact with the ground did not necessarily reduce the impact force during landing, but active hip and knee flexion motions did. The hip and knee flexion motion of landing was an important technical factor that affects anterior cruciate ligament (ACL) loading during the landing of the stop-jump task.

Correlation between neuronal antibodies and limbic encephalitis in Chinese Han subjects

A variety of anti-neuronal cell membrane antibodies such as voltage-gated potassium channel antibody, N-methyl-D-aspartate-2B-antibody, and glutamic acid decarboxylase antibody, are correlated with limbic encephalitis (LE). In this study on patients with LE, the clinical manifestations, psychology Wechsler Adult Intelligence Scale, cerebrospinal fluid, electrophysiology, magnetic resonance imaging, and anti-immune therapy were studied and immunological determination was conducted; it was found that patients of Chinese Han nationality showed 2 types of clinical manifestations: simple and complex. Lesions could also be divided into focal and scalable lesions, and the clinical manifestations and lesions scopes were associated with various antibodies and antibody types. The prognosis may improve if early diagnosis is conducted and early anti-immune therapy is implemented in LE patients.

On the analysis of inhomogeneous magnetic field spectrometer for laser-driven ion acceleration

We present a detailed study of the use of a non-parallel, inhomogeneous magnetic field spectrometer for the investigation of laser-accelerated ion beams. Employing a wedged yoke design, we demonstrate the feasibility of an in-situ self-calibration technique of the non-uniform magnetic field and show that high-precision measurements of ion energies are possible in a wide-angle configuration. We also discuss the implications of a stacked detector system for unambiguous identification of different ion species present in the ion beam and explore the feasibility of detection of high energy particles beyond 100 MeV/amu in radiation harsh environments.

Biodegradable micelles capable of mannose-mediated targeted drug delivery to cancer cells

A targeted micellar drug delivery system is developed from a biocompatible and biodegradable amphiphilic polyester, poly(Lac-OCA)-b-(poly(Tyr(alkynyl)-OCA)-g-mannose) (PLA-b-(PTA-g-mannose), that is synthesized via controlled ring-opening polymerization of O-carboxyanhydride (OCA) and highly efficient "Click" chemistry. Doxorubicin (DOX), a model lipophilic anticancer drug, can be effectively encapsulated into the micelles, and the mannose moiety allows active targeting of the micelles to cancer cells that specifically express mannose receptors, which thereafter enhances the anticancer efficiency of the drug. Comprised entirely of biodegradable and biocompatible polyesters, this micellar system demonstrates promising potentials for targeted drug delivery and cancer therapy.

Identification of EeSt-genome species in Pseudoroegneria and Elytrigia (Poaceae: Triticeae) by using SCAR markers from ITS sequences

To detect E(e)St-genome species in Pseudoroegneria and Elytrigia, the primers ES45 (5'-GTAGGCGACGGTTTTCA-3') and ES261 (5'-TCGCTACGTTCTTCATC-3') were designed as sequence characterized amplified region markers based on the 6-base pair indel in internal transcribed spacer 1 (ITS1) regions and conserved sites in the 5.8S regions, respectively. Polymerase chain reaction of ITS fragments in 27 Triticeae accessions was used for amplification with a touchdown thermocycling profile. Two amplicons were purified, sequenced, and aligned. The results indicated that: 1) primers ES45 and ES261 generated the expected products, 2) ITS sequences of E(e)St-genome species are characterized by a 6-base pair indel, and 3) 13 taxa in Pseudoroegneria and Elytrigia should be included in Trichopyrum. The primers ES45 and ES261 were useful for detecting ITS fragments with 6-bp indel and are helpful for clarifying taxonomic classifications of EeSt-genome species in Triticeae.

Ionic α-helical polypeptides toward nonviral gene delivery

The advent of polymeric materials has significantly promoted the development and rapid growth of various technologies in biomedical applications, such as tissue engineering and controlled drug and gene delivery. Water-soluble polypeptides bearing functional side chains and adopting stable secondary structures are a new class of functional polymeric materials of potentially broad applications in medicine and biotechnology. In this article, we summarize our recent effort on the design and synthesis of the water-soluble α-helical ionic polypeptides originally developed in our laboratory and highlight their applications in cell membrane penetration and nonviral gene/small interfering RNA (siRNA) delivery.

Antibody neutralization poses a barrier to intravitreal adeno-associated viral vector gene delivery to non-human primates

Gene delivery vectors based on adeno-associated viruses (AAV) have exhibited promise in both preclinical disease models and human clinical trials for numerous disease targets, including the retinal degenerative disorders Leber's congenital amaurosis and choroideremia. One general challenge for AAV is that preexisting immunity, as well as subsequent development of immunity following vector administration, can severely inhibit systemic AAV vector gene delivery. However, the role of neutralizing antibodies (NABs) in AAV transduction of tissues considered to be immune privileged, such as the eye, is unclear in large animals. Intravitreal AAV administration allows for broad retinal delivery, but is more susceptible to interactions with the immune system than subretinal administration. To assess the effects of systemic anti-AAV antibody levels on intravitreal gene delivery, we quantified the anti-AAV antibodies present in sera from non-human primates before and after intravitreal injections with various AAV capsids. Analysis showed that intravitreal administration resulted in an increase in anti-AAV antibodies regardless of the capsid serotype, transgene or dosage of virus injected. For monkeys injected with wild-type AAV2 and/or an AAV2 mutant, the variable that most significantly affected the production of anti-AAV2 antibodies was the amount of virus delivered. In addition, post-injection antibody titers were highest against the serotype administered, but the antibodies were also cross-reactive against other AAV serotypes. Furthermore, NAB levels in serum correlated with those in vitreal fluid, demonstrating both that this route of administration exposes AAV capsid epitopes to the adaptive immune system and that serum measurements are predictive of vitreous fluid NAB titers. Moreover, the presence of preexisting NAB titers in the serum of monkeys correlated strongly (R=0.76) with weak, decaying or no transgene expression following intravitreal administration of AAV. Investigating anti-AAV antibody development will aid in understanding the interactions between gene therapy vectors and the immune system during ocular administration and can form a basis for future clinical studies applying intravitreal gene delivery.

A rationally designed nanoparticle for RNA interference therapy in B-lineage lymphoid malignancies

The purpose of the present study was to further evaluate the biologic significance of the CD22ΔE12 molecular lesion and determine if it could serve as a molecular target for RNA interference (RNAi) therapy. We show that both pediatric and adult B-lineage lymphoid malignancies are characterized by a very high incidence of the CD22ΔE12 genetic defect. We provide unprecedented experimental evidence for a previously unrecognized causal link between CD22ΔE12 and aggressive biology of BPL cells by demonstrating that siRNA-mediated knockdown of CD22ΔE12 in primary BPL cells is associated with a marked inhibition of their clonogenicity. These findings provide the preclinical proof-of-concept that siRNA-mediated depletion of CD22ΔE12 may help develop effective treatments for high-risk and relapsed BPL patients who are in urgent need for therapeutic innovations. We also describe a unique polypeptide-based nanoparticle formulation of CD22ΔE12-siRNA as an RNAi therapeutic candidate targeting CD22ΔE12 that is capable of delivering its siRNA cargo into the cytoplasm of leukemia cells causing effective CD22ΔE12 depletion and marked inhibition of leukemic cell growth. Further development and optimization of this nanoparticle or other nanoformulation platforms for CD22ΔE12-siRNA may facilitate the development of an effective therapeutic RNAi strategy against paradigm shift in therapy of aggressive or chemotherapy-resistant B-lineage lymphoid malignancies.

High-throughput sequencing identification of genes involved with Varroa destructor resistance in the eastern honeybee, Apis cerana

Varroa destructor is the greatest threat to the honeybee Apis mellifera worldwide, while it rarely causes serious harm to its native host, the Eastern honeybee Apis cerana. The genetic mechanisms underlying the resistance of A. cerana to Varroa remain unclear. Thus, understanding the molecular mechanism of resistance to Varroa may provide useful insights for reducing this disease in other organisms. In this study, the transcriptomes of two A. cerana colonies were sequenced using the Illumina Solexa sequencing method. One colony was highly affected by mites, whereas the other colony displayed strong resistance to V. destructor. We determined differences in gene expression in the two colonies after challenging the colonies with V. destructor. After de novo transcriptome assembly, we obtained 91,172 unigenes for A. cerana and found that 288 differentially expressed genes varied by more than 15-fold. A total of 277 unigenes were present at higher levels in the non-affected colony. Genes involved in resistance to Varroa included unigenes related to skeletal muscle movement, olfactory sensitivity, and transcription factors. This suggests that hygienic behavior and grooming behavior may play important roles in the resistance to Varroa.

Prevalence of Chlamydia abortus in Belgian ruminants

Chlamydia (C.) abortus enzootic abortion still remains the most common cause of reproductive failure in sheep-breeding countries all over the world. Chlamydia abortus in cattle is predominantly associated with genital tract disease and mastitis. In this study, Belgian sheep (n=958), goats (n=48) and cattle (n=1849) were examined, using the ID ScreenTM Chlamydia abortus indirect multi-species antibody ELISA. In the sheep, the highest prevalence rate was found in Limburg (4.05%). The animals of Antwerp, Brabant and Liège tested negative. The prevalence in the remaining five regions was low (0.24% to 2.74%). Of the nine goat herds, only one herd in Luxembourg was seropositive. In cattle, the highest prevalence rate was found in Walloon Brabant (4.23%). The animals of Limburg and Namur tested negative. The prevalence rate in the remaining seven regions ranged between 0.39% and 4.02%.

Results of collagen plug occlusion of anal fistula: a multicentre study of 126 patients

AIM

The Biodesign(®) anal fistula plug was introduced as a means of obliterating the fistula tract and promoting healing through biocompatibility. The results demonstrated unexplained variations from good to bad. This report analysed the results of a retrospective multicentre study.

METHOD

All plug procedures performed in four Stockholm hospitals between June 2006 and June 2010 were identified and studied using a common protocol. The outcome after the first plug-insertion procedure was assessed by chart review performed a minimum of 8 months after plug insertion. Cox proportional-hazards models were used to assess the associations of various factors with fistula healing.

RESULTS

One-hundred and twenty-six patients (mean age 47 years) were deemed suitable for the plug procedure. Eighty-five per cent of fistulae were cryptoglandular, 64% of patients were male and a mean of 2.9 previous fistulae procedures had been performed. All patients, except four, had an indwelling seton at the time of the plug procedure, which was performed in accordance with previously established principles of day surgery. After a median of 13 months, 30 (24%) fistulae had closed with no discomfort or secretion reported. The outcome in the four hospitals varied from 13% to 33% with similar numbers of patients in each hospital. A success rate of 12% was observed for patients with anterior fistula compared with 32% for those with posterior tracks [hazard ratio (HR) for successful healing = 2.98; 95% CI: 1.01-8.78) and 41% for those with a lateral internal opening (HR = 3.76; 95% CI: 1.03-13.75). Age, sex and number of previous procedures were not associated with healing.

CONCLUSION

Four independent patient groups showed low success rates after the first plug-insertion procedure. Anterior fistulae were much less likely to heal compared with fistulae in other locations.

Control of stimulated Raman scattering in the strongly nonlinear and kinetic regime using spike trains of uneven duration and delay

Stimulated Raman scattering (SRS) in its strongly nonlinear, kinetic regime is controlled by a technique of deterministic, strong temporal modulation and spatial scrambling of laser speckle patterns, called spike trains of uneven duration and delay (STUD) pulses [B. Afeyan and S. Hüller (unpublished)]. Kinetic simulations show that the proper use of STUD pulses decreases SRS reflectivity by more than an order of magnitude over random-phase-plate or induced-spatial-incoherence beams of the same average intensity and comparable bandwidth.

High efficiency chlorine removal from polyvinyl chloride (PVC) pyrolysis with a gas-liquid fluidized bed reactor

In this research a gas-liquid fluidized bed reactor was developed for removing chlorine (Cl) from polyvinyl chloride (PVC) to favor its pyrolysis treatment. In order to efficiently remove Cl within a limited time before extensive generation of hydrocarbon products, the gas-liquid fluidized bed reactor was running at 280-320 °C, where hot N2 was used as fluidizing gas to fluidize the molten polymer, letting the molten polymer contact well with N2 to release Cl in form of HCl. Experimental results showed that dechlorination efficiency is mainly temperature dependent and 300 °C is a proper reaction temperature for efficient dechlorination within a limited time duration and for prevention of extensive pyrolysis; under this temperature 99.5% of Cl removal efficiency can be obtained within reaction time around 1 min after melting is completed as the flow rate of N2 gas was set around 0.47-0.85 Nm(3) kg(-1) for the molten PVC. Larger N2 flow rate and additives in PVC would enhance HCl release but did not change the final dechlorination efficiency; and excessive N2 flow rate should be avoided for prevention of polymer entrainment. HCl is emitted from PVC granules or scraps at the mean time they started to melt and the melting stage should be taken into consideration when design the gas-liquid fluidized bed reactor for dechlorination.

Chlamydial infections in Chinese livestock

The occurrence and impact of chlamydial infections in Western livestock is well documented in the international literature, but less is known aboutthese infections in livestock in the People's Republic of China. China's livestock production and its share in the global market have increased significantly in recent decades. In this review, the relevant English and Chinese literature on the epidemiology of chlamydial infections in Chinese livestock is considered, and biosecurity measures, prophylaxis and treatment of these infections in China's livestock are compared with Western practices. Chlamydial infections are highly prevalent in Chinese livestock and cause important economic losses, as they do in the rest of the world. Surveillance data and diagnostic results of abortion outbreaks in cattle, sheep and goats highlight the importance of virulent chlamydial infections in China's major ruminant species in many of China's provinces, autonomous regions and municipalities. Data from many of China's provincial divisions also indicate the widespread presence of chlamydial infections in industrially reared swine across the country. Less is known about chlamydial infections in yak, buffalo and horses, but available reports indicate a high prevalence in China's populations. In these reports, chlamydiosis was related to abortions in yak and pneumonia in horses. In Western countries, chlamydial infections are principally treated with antibiotics. In China, however, traditional medicine is often used in conjunction with antibiotics or used as an alternative treatment.

Overexpression of Ad5 precursor terminal protein accelerates recombinant adenovirus packaging and amplification in HEK-293 packaging cells

Recombinant adenoviruses are one of the most common vehicles for efficient in vitro and in vivo gene deliveries. Here, we investigate whether exogenous precursor terminal protein (pTP) expression in 293 cells improves the efficiency of adenovirus packaging and amplification. We used a piggyBac transposon-based vector and engineered a stable 293 line that expresses high level of Ad5 pTP, designated as 293pTP. Using the AdBMP6-GLuc that expresses green fluorescent protein (GFP), BMP6 and Gaussia luciferase, we found that the infectivity of AdBMP6-GLuc viral samples packaged in 293pTP cells was titrated up to 19.3 times higher than that packaged in parental 293 cells. AdBMP6-GLuc viral samples packaged in 293pTP cells exhibited significantly higher transduction efficiency in 143B and immortalized mouse embryonic fibroblast (iMEF) cells, as assessed by fluorescence-activated cell sorting analysis of GFP-positive cells, the luciferase activity assay and BMP6-induced osteogenic marker alkaline phosphatase activities in iMEFs. When adenovirus amplification efficiency was analyzed, we found that 293pTP cells infected with AdBMP6-GLuc yielded up to 12.6 times higher titer than that in parental 293 cells, especially at lower multiplicities of infection. These results strongly suggest that exogenous pTP expression may accelerate the packaging and amplification of recombinant adenoviruses. Thus, the engineered 293pTP cells should be a superior packaging line for efficient adenovirus production.

Trigger-responsive, fast-degradable poly(β-amino ester)s for enhanced DNA unpackaging and reduced toxicity

Poly(β-amino ester)s (PBAEs) represent an important class of cationic gene delivery materials which, however, suffer from uncontrolled DNA release due in part to the slow degradation of their polyester backbone. Additionally, PBAEs with high molecular weight (MW) also show considerable toxicities. In this study, we designed and developed PBAEs with trigger-responsive domains built-in polymer backbones that can be rapidly cleaved upon external UV light triggering to promote intracellular DNA release as well as reduce material toxicity. Photo-responsive PBAEs were prepared via polyaddition of (2-nitro-1,3-phenylene)bis(methylene) diacrylate and a bifunctional amine. The nitrobenzene moiety was placed in each repeating unit of the PBAE to allow fast response to external UV irradiation, and thus the ester linkers were cleaved and the polymers were degraded within several minutes upon UV irradiation. Cationic PBAEs with high MWs were able to mediate effective intracellular gene delivery, while upon UV irradiation post-transfection, enhanced DNA unpackaging and reduced material toxicity were observed, which collectively contributed to greatly improved transfection efficiencies in various mammalian cell types tested. This strategy allows precise manipulation of material toxicity and gene release profiles of PBAEs, and thus provides an effective design approach to address critical issues in non-viral gene delivery.

Polypeptides with quaternary phosphonium side chains: synthesis, characterization, and cell-penetrating properties

Polypeptides bearing quaternary phosphonium side chains were synthesized via controlled ring-opening polymerization of chlorine-functionalized amino acid N-carboxyanhydride monomers followed by one-step nucleophilic substitution reaction with triethylphosphine. The conformation of the resulting polypeptides can be controlled by modulating the side-chain length and α-carbon stereochemistry. The phosphonium-based poly(l-glutamate) derivatives with 11 σ-bond backbone-to-charge distance adopt stable α-helical conformation against pH and ionic strength changes. These helical, quaternary phosphonium-bearing polypeptides exhibit higher cell-penetrating capability than their racemic and random-coiled analogues. They enter cells mainly via an energy-independent, nonendocytic cell membrane transduction mechanism and exhibit low cytotoxicity, substantiating their potential use as a safe and effective cell-penetrating agent.

The effect of side-chain functionality and hydrophobicity on the gene delivery capabilities of cationic helical polypeptides

The rational design of effective and safe non-viral gene vectors is largely dependent on the understanding of the structure-property relationship. We herein report the design of a new series of cationic, α-helical polypeptides with different side charged groups (amine and guanidine) and hydrophobicity, and mechanistically unraveled the effect of polypeptide structure on the gene delivery capability. Guanidine-containing polypeptides displayed superior membrane activities to their amine-containing analogues via the pore formation mechanism, and thus possessed notably higher transfection efficiencies. Elongating the hydrophobic side chain also potentiated the membrane activities of the polypeptides, while at the meantime caused higher cytotoxicities. Upon an optimal balance between membrane activity and cytotoxicity, maximal transfection efficiency was achieved which outperformed commercial reagent Lipofectamine™ 2000 (LPF2000) by 3-6 folds. This study thus provides mechanistic insights into the rational design of non-viral gene delivery vectors, and the best-performing materials identified also serve as a promising addition to the existing systems.

Neotyphodium coenophialum-infected tall fescue and its potential application in the phytoremediation of saline soils

The growth response of endophyte-infected (EI) and endophyte-free (EF) tall fescue to salt stress was investigated under two growing systems (hydroponic and soil in pots). The hydroponic experiment showed that endophyte infection significantly increased tiller and leaf number, which led to an increase in the total biomass of the host grass. Endophyte infection enhanced Na accumulation in the host grass and improved Na transport from the roots to the shoots. With a 15 g l(-1) NaCl treatment, the phytoextraction efficiency of EI tall fescue was 2.34-fold higher than EF plants. When the plants were grown in saline soils, endophyte infection also significantly increased tiller number, shoot height and the total biomass of the host grass. Although EI tall fescue cannot accumulate Na to a level high enough for it to be termed a halophyte, the increased biomass production and stress tolerance suggested that endophyte/plant associations had the potential to be a model for endophyte-assisted phytoextraction in saline soils.

Anticancer Camptothecin-N-Poly(lactic acid) Nanoconjugates with Facile Hydrolysable Linker

We report a strategy of conjugating CPT to the terminal carboxylate group of polylactide (PLA) with a facile hydrolysable amino ester linker via a controlled polymerization method. The obtained CPT-N-PLA conjugates were able to self-assemble into 50-100 nanometer-sized conjugates (NCs) with desired in vitro physicochemical properties and showed enhanced in vivo therapeutic efficacy against Lewis lung carcinoma (LLC) induced in C57BL/6 mice.

Enhanced Non-Viral Gene Delivery to Human Embryonic Stem Cells via Small Molecule-Mediated Transient Alteration of Cell Structure

Non-viral gene delivery into human embryonic stem cells (hESCs)is an important tool for controlling cell fate. However, the delivery efficiency remains low due in part to the tight colony structure of the cells which prevents effective exposure towards delivery vectors. We herein report a novel approach to enhance non-viral gene delivery to hESCs by transiently altering the cell and colony structure. (R)-(+)-trans-4-(1-aminoethyl)-N-(4-pyridyl)cyclohexanecarboxamide (Y-27632), a small molecule that inhibits the rho-associated protein kinase pathway, is utilized to induce transient colony spreading which leads to increased transfection efficiency by 1.5 to 2 folds in a spectrum of non-viral transfection reagents including Lipofectamine 2000 and Fugene HD. After removal of Y-27632 post-transfection, cells can revert back to its normal state and do not show alteration of pluripotency. This approach provides a simple, effective tool to enhance non-viral gene delivery into adherent hESCs for genetic manipulation.

The use of gene activated matrix to mediate effective SMAD2 gene silencing against hypertrophic scar

Hypertrophic scar (HS) originates from the over-expression of transforming growth factor β (TGF-β) and downstream SMAD2. With attempts to rectify HS by RNA interference (RNAi) against SMAD2, we report the design of plasmid DNA encoding SMAD2 siRNA (pSUPER-SMAD2), and identify the optimal siRNA sequence toward maximal RNAi efficiency. To realize effective and sustained RNAi, we developed gene activated matrix (GAM) based on porous atelocollagen scaffold and embedded trimethyl chitosan-cysteine (TMCC)/pSUPER-SMAD2 polyplexes for promoting cell growth and gene transfection. The GAM exhibited porosity higher than 80%, pore size of 200-250 μm, desired mechanical strength, and sustained pSUPER-SMAD2 release profiles. Normal skin fibroblasts (NSFs) and hypertrophic scar fibroblasts (HSFs) were allowed to infiltrate and proliferate in GAM; at the meantime they were transfected with TMCC/pSUPER-SMAD2 polyplexes to display remarkably reduced SMAD2 levels that lasted for up to 10 days, consequently inhibiting the over-production of type I and type III collagen. We further unraveled the notably higher transfection levels of GAM in three-dimensional (3D) than in 2D environment, which was attributed to the improved cell-matrix interactions that promote cell proliferation and polyplex internalization. This highly safe and effective GAM may serve as a promising candidate towards HS treatment.

Single-shot soft x-ray laser linewidth measurement using a grating interferometer

The linewidth of a 14.7 nm wavelength Ni-like Pd soft x-ray laser was measured in a single shot using a soft x-ray diffraction grating interferometer. The instrument uses the time delay introduced by the gratings across the beam to measure the temporal coherence. The spectral linewidth of the 4d1S0-4p1P1 Ni-like Pd lasing line was measured to be Δλ/λ=3×10(-5) from the Fourier transform of the fringe visibility. This single shot linewidth measurement technique provides a rapid and accurate way to determine the temporal coherence of soft x-ray lasers that can contribute to the development of femtosecond plasma-based soft x-ray lasers.