Sculpting nanoparticle dynamics for single-bacteria-level screening and direct binding-efficiency measurement

Particle trapping and binding in optical potential wells provide a versatile platform for various biomedical applications. However, implementation systems to study multi-particle contact interactions in an optical lattice remain rare. By configuring an optofluidic lattice, we demonstrate the precise control of particle interactions and functions such as controlling aggregation and multi-hopping. The mean residence time of a single particle is found considerably reduced from 7 s, as predicted by Kramer’s theory, to 0.6 s, owing to the mechanical interactions among aggregated particles. The optofluidic lattice also enables single-bacteria-level screening of biological binding agents such as antibodies through particle-enabled bacteria hopping. The binding efficiency of antibodies could be determined directly, selectively, quantitatively and efficiently. This work enriches the fundamental mechanisms of particle kinetics and offers new possibilities for probing and utilising unprecedented biomolecule interactions at single-bacteria level.

Optical trapping is a versatile tool for biomedical applications. Here, the authors use an optofluidic lattice to achieve controllable multi-particle hopping and demonstrate single-bacteria-level screening and measurement of binding efficiency of biological binding agents through particle-enabled bacteria hopping.

[Application of narrow band imaging in the detection of premalignant and malignant lesions of the larynx]

Objective: To evaluate the role of narrow band imaging (NBI) endoscopy in the diagnosis of laryngeal lesions. Methods: A total of 136 patients with laryngeal lesions were examined by NBI and white light (WLI) endoscopy from July 2016 to May 2017. Sensitivity, specificity, accuracy, and positive predictive value (PPV) and negative predictive value (NPV) of NBI and WLI were calculated. SPSS 20.0 software was used to analyze the data. Results: Compared to WLI, NBI showed higher sensitivity (94.9% vs 83.3%), specificity (95.6% vs 84.4%), PPV (94.9% vs 82.3%), and NPV (95.6% vs 85.4%). There was high consistency of the results etween NBI and pathology (kappa=0.904, P<0.01). However, consistency of the findings between WLI and pathology was relatively weak (kappa=0.677, P<0.01). NBI showed the higher accuracy in diagnoses of both benign lesions (especially for premalignant lesions, P<0.01) and malignant lesions (especially for high-grade intraepithelial neoplasia, P<0.05) than WLI. NBI findings correlated with the pathological results (r=0.739, P<0.01). Conclusions: NBI demonstrates higher accuracy in the detection of premalignant and malignant lesions of the larynx.

[The progress of studies on aqueous humor dynamics abnormality induced by trabecular meshwork and Schlemm canal endothelial cell senescence and its relation with glaucoma]

Glaucoma is the second leading cause of blindness in the world next to cataract. Aging is a strong risk factor leading to elevated intraocular pressure (IOP). IOP is associated with aqueous humor circulation. Trabecular meshwork cells and Schlemm canal endothelial cells, which form the conventional outflow pathway, play an important role in maintaining the IOP. Cell senescence induces abnormalities of the aqueous humor dynamics, leading to elevated IOP. Trabecular meshwork cells cause increased intrinsic stiffness, autophagy dysfunction, abnormal expression of microRNA and mitochondrial dysfunction with senescence. The senescence of Schlemm canal endothelial cells decreases cell permeability and mechanotransduction and disrupts the endothelial nitric oxide synthase signaling pathway. The changes will increase aqueous humor outflow resistance and elevate IOP. This review discusses how cell senescence induces aqueous humor dynamics abnormalities and the relation with glaucoma. (Chin J Ophthalmol, 2017, 53: 868-873).

BRAF inhibitor-associated cutaneous squamous cell carcinoma: new mechanistic insight, emerging evidence for viral involvement and perspectives on clinical management

Mutations in the BRAF proto-oncogene occur in the majority of cutaneous melanomas. The commonly detected valine (V) to glutamate (E) mutation (V600E) is known to drive melanomagenesis and has thus been the target of two highly selective chemotherapeutic agents: vemurafenib and dabrafenib. While BRAF inhibitor therapy has revolutionized the treatment of metastatic melanoma, unanticipated cutaneous toxicities, including the development of cutaneous squamous cell carcinomas (cSCCs), are frequently reported and hinder therapeutic durability. However, the mechanisms by which BRAF inhibitors induce cutaneous neoplasms are poorly understood, thus posing a challenge for specific therapies. In this review, we summarize the clinical and molecular profiles of BRAF inhibitor-associated cSCCs, with a focus on factors that may contribute to disease pathogenesis. In particular, we discuss the emerging evidence pointing towards viral involvement in BRAF inhibitor-induced cutaneous neoplasms and offer new perspectives on future therapeutic interventions. Continued clinical and mechanistic studies along this line will not only allow for better understanding of the pathogenic progression of BRAF inhibitor-induced cSCCs, but will also lead to development of new therapeutic and preventative options for patients receiving targeted cancer therapy.

High-resolution and multi-range particle separation by microscopic vibration in an optofluidic chip

An optofluidic chip is demonstrated in experiments for high-resolution and multi-range particle separation through the optically-induced microscopic vibration effect, where nanoparticles are trapped in loosely overdamped optical potential wells created with combined optical and fluidic constraints. It is the first demonstration of separating single nanoparticles with diameters ranging from 60 to 100 nm with a resolution of 10 nm. Nanoparticles vibrate with an amplitude of 3-7 μm in the loosely overdamped potential wells in the microchannel. The proposed optofluidic device is capable of high-resolution particle separation at both nanoscale and microscale without reconfiguring the device. The separation of bacteria from other larger cells is accomplished using the same chip and operation conditions. The unique trapping mechanism and the superb performance in high-resolution and multi-range particle separation of the proposed optofluidic chip promise great potential for a diverse range of biomedical applications.

[Study of Basal metabolic rate of 81 young adults aged 20-29 years old in Changsha]

Objective: To determine the basal metabolic rate (BMR) of young adults aged between 20-29 years old in Changsha. Methods: We recruited volunteers to join in our research project from April to May, 2015. All recruited volunteers must meet the inclusion criteria: aged 20-29 years old, height between 164-180 centimeters in males and 154-167 centimeters in females, in good health condition, and with no habit of regular physical exercise in last year. Finally, 81 qualified volunteers were selected as research objects, including 43 males and 38 females. The BMR, resting lying metabolism rate and resting sitting metabolism rate of the subjects were detected, and the determined BMR was compared with the calculated results: from the adjusted Schofield equation. Results The BMR, resting lying metabolism rate and resting sitting metabolism rate among males were (166.10±22.09), (174.22±24.56), and (179.54±23.35) kJ·m(-2)·h(-1), respectively, which were all higher than those among females were (137.70±20.04), (149.79±19.25), and (167.78±26.02) kJ·m(-2)·h(-1), respectively, (P<0.001). The BMR of males and females calculated from the adjusted Schofield equation were (160.83±3.93), and (140.29±4.18) kJ·m(-2)·h(-1), respectively, and there was no significantly statistical difference found between the determined BMR and the calculated results from Schofield equation (adjusted) classified by sex, all P values >0.05. Conclusion: The BMR of young adults aged 20-29 years old in Changsha was in the national average level, and the adjusted Schofield equation displayed fine accuracy in predicting BMR of young adults aged 20-29 years old in Changsha.

Dysregulation of the MEK/ERK/MNK1 signalling cascade by middle T antigen of the trichoydsplasia spinulosa polyomavirus

BACKGROUND

Trichodysplasia spinulosa (TS) is a disfiguring folliculocentric cutaneous disease caused by infection with the trichodysplasia spinulosa polyomavirus (TSPyV). The TSPyV genome contains splice variants encoding the middle tumour (mT) antigen, although the potential role for TSPyV mT antigen in disease development remains unknown.

OBJECTIVE

The current study was designed to investigate the mechanistic properties of TSPyV mT antigen, which may further our understanding of TS pathogenesis and provide insight into potential therapies.

METHODS

A lentiviral packaging system was used to create an inducible cell line expressing TSPyV mT antigen. Proteins were extracted, separated by SDS-PAGE and subjected to Western blot analysis. Co-immunoprecipitation experiments and mutational analyses were also performed to evaluate protein-protein interactions of mT antigen.

RESULTS

We describe a novel mechanism of action for mT antigen that involves hyperactivation of MEK, ERK and MNK1. Our findings suggest that dysregulation of these key signalling molecules depends upon TSPyV mT antigen interaction with protein phosphatase 2A (PP2A) via intact Zn binding motifs.

CONCLUSION

Given that PP2A interaction and MEK/ERK/MNK1 phosphorylation are associated with high levels of cell proliferation and inflammation, our findings provide new evidence that TSPyV mT antigen may contribute to the pro-proliferative conditions that lead to TS development.

The revitalisation of flexor tendon allografts with bone marrow stromal cells and mechanical stimulation: An ex vivo model revitalising flexor tendon allografts

Objectives

The present study describes a novel technique for revitalising allogenic intrasynovial tendons by combining cell-based therapy and mechanical stimulation in an ex vivo canine model.

Methods

Specifically, canine flexor digitorum profundus tendons were used for this study and were divided into the following groups: (1) untreated, unprocessed normal tendon; (2) decellularised tendon; (3) bone marrow stromal cell (BMSC)-seeded tendon; and (4) BMSC-seeded and cyclically stretched tendon. Lateral slits were introduced on the tendon to facilitate cell seeding. Tendons from all four study groups were distracted by a servohydraulic testing machine. Tensile force and displacement data were continuously recorded at a sample rate of 20 Hz until 200 Newton of force was reached. Before testing, the cross-sectional dimensions of each tendon were measured with a digital caliper. Young’s modulus was calculated from the slope of the linear region of the stress-strain curve. The BMSCs were labeled for histological and cell viability evaluation on the decellularized tendon scaffold under a confocal microscope. Gene expression levels of selected extracellular matrix tendon growth factor genes were measured. Results were reported as mean ± SD and data was analyzed with one-way ANOVAs followed by Tukey’s post hoc multiple-comparison test.

Results

We observed no significant difference in cross-sectional area or in Young’s modulus among the four study groups. In addition, histological sections showed that the BMSCs were aligned well and viable on the tendon slices after two-week culture in groups three and four. Expression levels of several extracellular matrix tendon growth factors, including collagen type I, collagen type III, and matrix metalloproteinase were significantly higher in group four than in group three (p < 0.05).

Conclusion

Lateral slits introduced into de-cellularised tendon is a promising method of delivery of BMSCs without compromising cell viability and tendon mechanical properties. In addition, mechanical stimulation of a cell-seeded tendon can promote cell proliferation and enhance expression of collagen types I and III in vitro.

Cite this article: J. H. Wu, A. R. Thoreson, A. Gingery, K. N. An, S. L. Moran, P. C. Amadio, C. Zhao. The revitalisation of flexor tendon allografts with bone marrow stromal cells and mechanical stimulation: An ex vivo model revitalising flexor tendon allografts. Bone Joint Res 2017;6:179–185. DOI: 10.1302/2046-3758.63.BJR-2016-0207.R1.

[PM2.5 and polluted gas exposure induced acute injury in rats'larynx membrane]

Objective:To study acute injury of rat's larynx membrane which were exposured to PM2.5 and polluted gas in serious air pollution. Method:Rats were divided into 3 groups of 5 animals each, the normal control group, gas exposured group, PM2.5 +gas exposured group. The control group served as the normal healthy control, rats of the gas exposured group had been exposured polluted gas in the A cabin, rats of PM2.5 +gas exposured group had been exposured PM2.5 and polluted gas in the B cabin. The total exposure time was six days. We collected specimen from 3 groups immediately after exposure. Histopathological changes in the rat's larynx membrane were assessed using hematoxylin and eosin staining(HE), the expression of IL-1β in laryngeal mucous membrane were assessed using immunohistochemical staining(IHC), and the ultrastructure changes were observed under TEM. Result:HE staining showed the rat's laryngeal mucosa cells in the normal control group had no obvious abnormalities, laryngeal mucosa of rats in the two experimental group had different degrees of cell proliferation, cell polarity change, etc. IHC staining showed that there's no obvious expression of IL-1β in laryngeal mucous membrane in the normal control group, and positive expression in the two experimental group. TEM showed the control group had no obvious abnormalities, the laryngeal mucosa cells in the two groups of experimental groups had been found irregular nucleus and damaged mitochondria. Conclusion:Exposed to PM2.5 and polluted gas in severe atmospheric pollution 6 days, the acute damage in rats laryngeal mucosa can be observed.

Substrate co-doping modulates electronic metal-support interactions and significantly enhances single-atom catalysis

Transitional metal nanoparticles or atoms deposited on appropriate substrates can lead to highly economical, efficient, and selective catalysis. One of the greatest challenges is to control the electronic metal-support interactions (EMSI) between the supported metal atoms and the substrate so as to optimize their catalytic performance. Here, from first-principles calculations, we show that an otherwise inactive Pd single adatom on TiO₂(110) can be tuned into a highly effective catalyst, e.g. for O₂ adsorption and CO oxidation, by purposefully selected metal-nonmetal co-dopant pairs in the substrate. Such an effect is proved here to result unambiguously from a significantly enhanced EMSI. A nearly linear correlation is noted between the strength of the EMSI and the activation of the adsorbed O₂ molecule, as well as the energy barrier for CO oxidation. Particularly, the enhanced EMSI shifts the frontier orbital of the deposited Pd atom upward and largely enhances the hybridization and charge transfer between the O₂ molecule and the Pd atom. Upon co-doping, the activation barrier for CO oxidation on the Pd monomer is also reduced to a level comparable to that on the Pd dimer which was experimentally reported to be highly efficient for CO oxidation. The present findings provide new insights into the understanding of the EMSI in heterogeneous catalysis and can open new avenues to design and fabricate cost-effective single-atom-sized and/or nanometer-sized catalysts.

Orthogonal design in the optimization of a start codon targeted (SCoT) PCR system in Roegneria kamoji Ohwi

Roegneria kamoji Ohwi is an excellent forage grass due to its high feeding value and high resistance to some biotic and abiotic stresses. However, the start codon targeted (SCoT) polymorphism has not been conducted on R. kamoji. In this study, an orthogonal L₁₆ (4⁵) design was employed to investigate the effects of five factors (Mg²⁺, dNTPs, Taq DNA polymerase, primer, and template DNA) on the polymerase chain reaction (PCR) to determine the optimal SCoT-PCR system for R. kamoji. The results showed that the most suitable conditions for SCoT-PCR in R. kamoji included 1.5 mM Mg²⁺, 0.15 mM dNTPs, 1.0 U Taq DNA polymerase, 0.4 pM primer, and 40 ng template DNA. SCoT primers 39 and 41 were used to verify the stability of the optimal reaction system, and amplification bands obtained from diverse samples were found to be clear, rich, and stable in polymorphisms, indicating that this reaction system can be used for SCoT-PCR analysis of R. kamoji. We have developed a simple and rapid way to study the mutual effects of factors and to obtain positive results through the use of an orthogonal design L₁₆ (4⁵) to optimize the SCoT-PCR system. This method may provide basic information for molecular marker-assisted breeding and analyses of genetic diversity in R. kamoji.

Discovery of differentially expressed genes in cashmere goat (Capra hircus) hair follicles by RNA sequencing

The mammalian hair follicle (HF) is a unique, highly regenerative organ with a distinct developmental cycle. Cashmere goat (Capra hircus) HFs can be divided into two categories based on structure and development time: primary and secondary follicles. To identify differentially expressed genes (DEGs) in the primary and secondary HFs of cashmere goats, the RNA sequencing of six individuals from Arbas, Inner Mongolia, was performed. A total of 617 DEGs were identified; 297 were upregulated while 320 were downregulated. Gene ontology analysis revealed that the main functions of the upregulated genes were electron transport, respiratory electron transport, mitochondrial electron transport, and gene expression. The downregulated genes were mainly involved in cell autophagy, protein complexes, neutrophil aggregation, and bacterial fungal defense reactions. According to the Kyoto Encyclopedia of Genes and Genomes database, these genes are mainly involved in the metabolism of cysteine and methionine, RNA polymerization, and the MAPK signaling pathway, and were enriched in primary follicles. A microRNA-target network revealed that secondary follicles are involved in several important biological processes, such as the synthesis of keratin-associated proteins and enzymes involved in amino acid biosynthesis. In summary, these findings will increase our understanding of the complex molecular mechanisms of HF development and cycling, and provide a basis for the further study of the genes and functions of HF development.

[Comparison of the clinical efficacy of laparoscopic wedge resection and open wedge resection for the treatment of gastrointestinal stromal tumor]

OBJECTIVE

To compare the clinical efficacy of laparoscopic wedge resection and open wedge resection in the treatment of gastrointestinal stromal tumor.

METHODS

Fifty-five patients with gastrointestinal stromal tumor who underwent laparoscopic wedge resection and 61 cases underwent open wedge resection in Tongji Hospital from January 2009 to December 2014 were included into this study. The perioperative, surgical operative and postoperative data of the patients were documented and analyzed.

RESULTS

The operation time of laparoscopic group was significantly shorter than that of the open group [(108.2±27.2) min versus (139.9±75.3) min,P=0.021], the amount of intraoperative blood loss was overtly reduced in the laparoscopic group [(57.1±48.7) ml versus (100.6±45.8) ml,P=0.011], the time to postoperative exhaust or defecation was (2.2±1.4) d in the laparoscopic group and (3.5±1.8) d in the open group (P=0.028), and the length of hospital stay was (5.7±1.3) d versus (6.9±2.1) d (P=0.044). There were intraoperative complication in one case and postoperative complications in 5 cases, while neither tumor rupture nor obvious perioperative complication was observed in the laparoscopic group. During the period of follow-up (mean, 15.3 months), only one case of replase occurred in the laparoscopic group while four cases of relapse were observed in the open group.

CONCLUSIONS

With experienced skills and to strictly comply with the surgical indications, laparoscopic wedge resection is prior to tranditional open wedge resection for the treatment of gastrointestinal stromal tumor. The laparoscopic wedge resection can achieve the standard of R0 resection, keep the resected tumor with an intact capsule, reduce the operating time and operative trauma, promote the postoperative recovery and get a better prognosis. Therefore, it is a feasible, safe, minimally invasive surgical procedure associated with a rapid postoperative recovery.

[Application of a microvascular anastomotic coupling device in solitary upper extremity artery injury repairs]

OBJECTIVE

To investigate the outcomes of applying microvascular anastomotic coupling devices in solitary upper extremity artery injury repairs and to optimize parameters for optimal clinical outcome.

METHODS

From March to September 2013, 19 injured arteries from 18 male patients who presented at Department of Hand Surgery, Beijing Jishuitan Hospital with traumatic arterial lacerations of their upper extremities went through rapid repair procedures. COUPLER, a microvascular anastomotic coupling device was applied in these artery injury repair operations. The 19 repaired arteries included 3 brachial arteries, 6 ulnar arteries and 10 radial arteries. After the procedures, all the 18 patients were then followed up by clinical specialists and examined with color doppler flow imaging for the effective recovery of artery circulation and upper extremities functionality.

RESULTS

The average time of artery repairs for all the 19 damaged arteries among the 18 patients was 278 s and the average follow-up time was (71.5±40.9) d with the longest follow-up time as 116 d and shortest as 14 d. No patient returned to the operating room after the procedures and after being dismissed from the hospital. None of the 18 cases were reported to have problems with circulation and thrombosis formation in their upper extremities. Color Doppler imaging showed that the arterial anastomotic site for all the 19 repaired arteries were unobstructed with artery blood spectrum at both ends. Three patients with radial artery repairs complained about mild pressure pain at the site of vascular anastomosis; while the other 15 patients all expressed satisfactory outcomes of the surgery and recovery. These evidences indicated that the outcomes of our initial evaluation for the solitary upper extremity artery injury repairs by using anastomotic coupling devices were positive.

CONCLUSION

Our observations have showed that microvascular anastomotic coupling devices can be used for repairing of solitary upper extremity artery injures. The procedures are quick, effective and safe. The clinical application of this microvascular anastomotic coupling device in artery injures is promising, however, additional evidences through further clinical investigation with more cases are warranted.

The heterogeneous energy landscape expression of KWW relaxation

Here we show a heterogeneous energy landscape approach to describing the Kohlrausch-Williams-Watts (KWW) relaxation function. For a homogeneous dynamic process, the distribution of free energy landscape is first proposed, revealing the significance of rugged fluctuations. In view of the heterogeneous relaxation given in two dynamic phases and the transmission coefficient in a rate process, we obtain a general characteristic relaxation time distribution equation for the KWW function in a closed, analytic form. Analyses of numerical computation show excellent accuracy, both in time and frequency domains, in the convergent performance of the heterogeneous energy landscape expression and shunning the catastrophic truncations reported in the previous work. The stretched exponential β, closely associated to temperature and apparent correlation with one dynamic phase, reveals a threshold value of 1/2 defining different behavior of the probability density functions. Our work may contribute, for example, to in-depth comprehension of the dynamic mechanism of glass transition, which cannot be provided by existing approaches.

Colored Sticky Traps to Selectively Survey Thrips in Cowpea Ecosystem

The bean flower thrips, Megalurothrips usitatus (Bagrall) (Thysanoptera: Thripidae), is an important pest of legume crops in South China. Yellow, blue, or white sticky traps are currently recommended for monitoring and controlling thrips, but it is not known whether one is more efficient than the other or if selectivity could be optimized by trap color. We investigated the response of thrips and beneficial insects to different-colored sticky traps on cowpea, Vigna unguiculata. More thrips were caught on blue, light blue, white, and purple traps than on yellow, green, pink, gray, red, or black traps. There was a weak correlation on the number of thrips caught on yellow traps and survey from flowers (r = 0.139), whereas a strong correlation was found for blue traps and thrips' survey on flowers (r = 0.929). On commercially available sticky traps (Jiaduo®), two and five times more thrips were caught on blue traps than on white and yellow traps, respectively. Otherwise, capture of beneficial insects was 1.7 times higher on yellow than on blue traps. The major natural enemies were the predatory ladybird beetles (63%) and pirate bugs Orius spp. (29%), followed by a number of less representative predators and parasitoids (8%). We conclude the blue sticky trap was the best to monitor thrips on cowpea in South China.

Hair follicle transcriptome profiles during the transition from anagen to catagen in Cashmere goat (Capra hircus)

Previous molecular genetic studies of the goat hair life cycle have focused primarily on a limited number of genes and proteins. To identify additional genes that may play important roles in hair follicle cycle regulation, Illumina sequencing technology was used to catalog differential gene expression profiles in the hair growth cycle (anagen to catagen) of goat, comparing the primary hair follicle with the secondary hair follicle. There were 13,769 and 12,240 unigenes assembled from the reads obtained from primary hair follicle and secondary hair follicle, respectively. Genes encoding keratin proteins and keratin-associated proteins were the most highly expressed. A total of 5899 genes were differentially expressed in anagen vs catagen primary hair follicles, with 532 genes up-regulated and 5367 genes down-regulated. A total of 5208 genes were differentially expressed in anagen vs catagen secondary hair follicle, including 545 genes that were up-regulated and 4663 genes that were down-regulated. Numerous hair growth genes are expressed in the goat hair follicle, of which 73 genes showed co-up-regulation in both hair follicles during the anagen stage. Many of these up-regulated genes, such as STC2, VEGFR, and ROR2, are known to be transfactors in the process of cell differentiation and in the cell cycle. The differential gene expression profiles between primary hair follicles and secondary hair follicles obtained provide a foundation for future studies examining the network of gene expression controlling hair growth cycle in Cashmere goat.

Molecular insight into the viral biology and clinical features of trichodysplasia spinulosa

Trichodysplasia spinulosa (TS) is a disfiguring skin disease that occurs most frequently in patients receiving immunosuppressive therapies, and is thus frequently associated with organ transplantation. TS is characterized clinically by folliculocentric papular eruption, keratin spine formation and development of leonine face; and histologically by expansion of the inner root sheath epithelium and high expression of the proliferative marker Ki-67. Recent discovery of the TS-associated polyomavirus (TSPyV) and emerging studies demonstrating the role of TSPyV tumour antigens in cell proliferation pathways have opened a new corridor for research on TS. In this brief review, we summarize the clinical and histological features of TS and evaluate the current options for therapy. Furthermore, we address the viral aetiology of the disease and explore the mechanisms by which TSPyV may influence TS development and progression. As reports of TS continue to rise, clinician recognition of TS, as well as accompanying research on its underlying pathogenesis and therapeutic options, is becoming increasingly important. It is our hope that heightened clinical suspicion for TS will increase rates of diagnosis and will galvanize both molecular and clinical interest in this disease.

Emerging Yr26-Virulent Races of Puccinia striiformis f. tritici Are Threatening Wheat Production in the Sichuan Basin, China

Stripe rust, caused by Puccinia striiformis f. tritici, is one of the most destructive diseases of wheat in the world. The Sichuan Basin is one of the most important regions of wheat production and stripe rust epidemics in China. Stripe rust resistance gene Yr26 (the same gene as Yr24) has been widely used in wheat breeding programs and in many cultivars grown in this region since the gene was discovered in the early 1990s. Virulence to Yr26 has increased in frequency since its first detection in 2008. The objective of this study was to assess the vulnerability of the wheat cultivars and breeding lines in the Sichuan Basin to Yr26-virulent races. In total, 85 wheat accessions were tested with Yr26-avirulent races CYR32, CYR33, and Su11-4 and two Yr26-virulent races, V26/CM42 and V26/Gui22. DNA markers for Yr26 were used to determine the presence and absence of Yr26 in the wheat accessions. Of the 85 wheat accessions, only 5 were resistant and 19 susceptible to all races tested, and the remaining 61 were resistant to at least one or more races tested in seedling stage. In all, 65 (76.5%) accessions were susceptible to the emerging Yr26-virulent race V26/Gui22. In field tests, susceptible accessions increased from 31.8% in a nursery inoculated with predominant and Yr26-avirulent races to 61.2% in the nursery inoculated with the predominant races mixed with V26/Gui22. Based on the results of the molecular marker and race tests, 33 (38.8%) accessions were determined to have Yr26, showing that the Yr26 virulence is a major threat to wheat production in the Sichuan Basin and potentially in other regions of China.

Sequence variation and molecular evolution of BMP4 genes

Bone morphogenetic protein 4 (BMP4) regulates skeletogenesis, osteoblastic differentiation, and the induction of hair follicles. Its protein-coding region contains a signal peptide, prodomain (which regulates post-translational synthesis), and a mature domain (which mediates gene function). Previous studies considered this gene to be conserved. By reanalyzing the coding region of BMP4 in 16 mammalian species, we found that the mature domain is conserved in mammals. A comparison of the putative amino acid sequence demonstrates that BMP4 is relatively conserved. Two domains in BMP4 are connected by a random coil. The protein conformation differs between the Muridae family and other species, which might be associated with the body type of the former group.

Wing kinematics in a hovering dronefly minimize power expenditure

When an insect hovers or performs constant-speed flight, its wings flap at certain amplitude, frequency, angle of attack, etc., and the flight is balanced (vertical force equals to the weight, and horizontal force and pitch moment are zero). It is possible that when some other sets of values of wing kinematical parameters are used, the force and moment balance conditions can still be satisfied. Does the wing kinematics used by a constant-speed flying insect minimize the power expenditure? In this study, whether the wing kinematics used by a freely hovering dronefly minimizes its energy expenditure was investigated. First, the power consumption using the set of values of wing kinematical parameters that was actually employed by the insect was computed. Then, the kinematical parameters were changed while keeping the equilibrium flight conditions satisfied, and the power consumption was recalculated. It was found that wing kinematical parameters used by the freely hovering dronefly are very close to that minimize its energy consumption, and they can ensure the margin of controllability from hovering to maneuvers. That is, slight change of wing kinematical parameters did not cause significant change of the specific power (maintained a relatively small value).

Targeting focal adhesion turnover in invasive breast cancer cells by the purine derivative reversine

Background:

The dynamics of focal adhesion (FA) turnover is a key determinant for the regulation of cancer cell migration. Here we investigated FA turnover in a panel of breast cancer models with distinct invasive properties and evaluated the impact of reversine on this turnover in relation to cancer cell invasion in in vitro and in vivo conditions.

Methods:

Live imaging and immunofluorescence assays were used to investigate FA turnover in breast cancer cells. Biochemical studies were used to investigate the impact of reversine on FA signalling and turnover. In vivo activity was investigated using orthotopic breast cancer mouse models.

Results:

Accelerated FA disassembly from plasma membrane protrusions was observed in invasive compared with non-invasive breast cancer cells or non-immortalised mammary epithelial cells. Reversine significantly inhibited FA disassembly leading to stable FAs, which was associated with reduced cell motility and invasion. The inhibitory effect of reversine on FA turnover accounted for a large part on its capacity to interfere with FAK function on regulating its downstream targets. In orthotopic breast cancer mouse models, reversine revealed a potent inhibitory activity on tumour progression to metastasis.

Conclusion:

These results support the utility of targeting FA turnover as a therapeutic approach for invasive breast cancer.