Bacterial cellulose membrane combined with BMSCs promotes wound healing by activating the notch signaling pathway

ObjectiveThe bacterial cellulose membrane (BCM) has been widely studied and applied as a new biomaterial for wound healing, but causes pain with frequent dressing changes. Local application of bone marrow mesenchymal stem cells (BMSCs) requires a niche. Furthermore, the effect and mechanism of the BCM combined with BMSCs have not been reported.MethodsMorphological and chemical identifications of BCMs were investigated by porosity analyses, scanning electron microscopy, and Fourier-transform infrared spectroscopy. Biological wound dressings (BWDs) were prepared by the BCM in combination with BMSCs. The biological effects of BWDs on human dermal fibroblast (HDF) and VEGF-A in human vascular endothelial cells (HuVECs) were detected in vitro, and the effect of BWDs on acute wounds in mice was detected in vivo. Collagen and angiogenesis were evaluated through hematoxylin–eosin staining and Masson staining. The expressions of COL-1 and VEGF-A and the activation of the Notch signaling pathway in vivo and in vitro were detected by quantitative reverse-transcriptase polymerase chain reaction.ResultsThe BCM had a nanoscale structure and provided a partial niche for the survival and proliferation of BMSCs. BWDs were successfully prepared and regulated the biological behaviors of wound healing-related cells in vitro and upregulated the expressions of COL-1 in HDF and VEGF-A in HuVECs. BWDs promoted wound healing by increasing collagen type I synthesis and angiogenesis in acute wounds in mice.ConclusionsBWDs prepared by the combination of nanomaterial BCMs and BMSCs facilitated acute wound healing, which may be regulated by activating the Notch signaling pathway

Phylogenetic and Pathotypical Analysis of Two Virulent Newcastle Disease Viruses Isolated from Domestic Ducks in China

Two velogenic Newcastle disease viruses (NDV) obtained from outbreaks in domestic ducks in China were characterized in this study. Phylogenetic analysis revealed that both strains clustered with the class II viruses, with one phylogenetically close to the genotype VII NDVs and the other closer to genotype IX. The deduced amino acid sequence of the cleavage site of the fusion (F) protein confirmed that both isolates contained the virulent motif 112RRQK/RRF117 at the cleavage site. The two NDVs had severe pathogenicity in fully susceptible chickens, resulting in 100% mortality. One of the isolates also demonstrated some pathogenicity in domestic ducks. The present study suggests that more than one genotype of NDV circulates in domestic ducks in China and viral transmission may occur among chickens and domestic ducks

NMR solution structure of the major G-quadruplex structure formed in the human BCL2 promoter region

BCL2 protein functions as an inhibitor of cell apoptosis and has been found to be aberrantly expressed in a wide range of human diseases. A highly GC-rich region upstream of the P1 promoter plays an important role in the transcriptional regulation of BCL2. Here we report the NMR solution structure of the major intramolecular G-quadruplex formed on the G-rich strand of this region in K(+) solution. This well-defined mixed parallel/antiparallel-stranded G-quadruplex structure contains three G-tetrads of mixed G-arrangements, which are connected with two lateral loops and one side loop, and four grooves of different widths. The three loops interact with the core G-tetrads in a specific way that defines and stabilizes the overall G-quadruplex structure. The loop conformations are in accord with the experimental mutation and footprinting data. The first 3-nt loop adopts a lateral loop conformation and appears to determine the overall folding of the BCL2 G-quadruplex. The third 1-nt double-chain-reversal loop defines another example of a stable parallel-stranded structural motif using the G(3)NG(3) sequence. Significantly, the distinct major BCL2 promoter G-quadruplex structure suggests that it can be specifically involved in gene modulation and can be an attractive target for pathway-specific drug design

RESEARCH Virulent Avian Infectious Bronchitis Virus, People’s Republic of China

A virulent avian infectious bronchitis virus (IBV) was isolated from 30-day-old broiler chickens that exhibited respiratory symptoms, nephropathologic lesions, and a high proportion of deaths in the People’s Republic of China during 2005. The strain, designated YN, was genetically and pathologically characterized. Phylogenetic analysis showed that YN and most of the previously characterized IBV isolates found in China were phylogenetically classifi ed into 2 main genetic clusters. The YN isolate caused severe lesions and resulted in deaths of 65 % in experimental infections of 30-day-old specifi c-pathogen–free chickens. Tracheal and severe kidney lesions developed in all infected birds, confi rming the ability of YN strain to induce both respiratory and renal disease. IBV antigens were detected by immunohistochemical analysis in the trachea, lung, kidney, and bursa, consistent with histopathologic observations, virus isolation, and reverse transcription PCR detection. We showed that YN IBV exhibits severe pathogenicity in chickens, and that similar viruses are prevalent in China. Avian infectious bronchitis virus (IBV), a member of family Coronaviridae, order Nidovirales, causes a highly contagious respiratory and sometimes urogenital disease of chickens that is characterized by respiratory signs, nephritis, or reduced egg production and quality in layer chickens. IBV is a major poultry pathogen that is endemic worldwide and leads to serious economic losses. The main method of protecting poultry from infectious bronchitis (IB) is the administration of live or killed vaccines. However, IB continues to cause economic losses in the poultry industry despite intensive vaccinatio

Dual-modality UDV-PIV system for measurement of solid-liquid flow in sewage facilities

Population growth and global industrialization cause a dramatic increase in the amount of sewage sludge produced annually worldwide from Municipal and Industrial Wastewater treatment. The efficient measurement of sewage, which is a typical solid-liquid two-phase flow, has become an important issue that requires to be urgently addressed. In this study, an improved Ultrasonic Doppler Velocimetry (UDV) is proposed to optimize the probe design and hardware design, which reduces the influence of working frequency and echo reverberation on accuracy and improves the stability of the system. A Doppler peak extraction and superposition method is also put forward to correct the offset of Doppler peak frequency. In this paper, Particle Image Velocimetry (PIV) is used to calibrate the UDV system to modify the measurement model of ultrasonic Doppler liquid-solid two-phase flow, and dynamic experiments are carried out in a vertical steel pipe with inner diameter of 50 mm at different flow conditions. The results show that the accuracy and stability of UDV measurement system are greatly improved, with a maximum relative error of 1.49%

Histopathology on tissues from 1-week-old ducks infected with NDV GD09-2 or SD09 (H&E).

<p>B and C: hemorrhage (group GD09-2, black arrow) or degeneration of renal tubules epithelial cells (group SD09, black arrow) and eosinophil infiltration (group SD09, white arrow) in the kidneys; E and F: necrosis and disappear of lymphocyte (black arrow) or coagulation necrosis of massive tissue (white arrow) in the spleens; H and I: villus missing (white arrow) and necrosis of epithelial cell infiltration (black arrow) in the small intestines; K and L: dilatation of hepatic sinus and thrombus (group GD09-2, black arrow), lymphocyte infiltration (group GD09-2, white arrow), dilatation of hepatic sinus (group SD09, black arrow) and venous congestion (group SD09, white arrow) in the livers. A, D, G and J: Corresponding control tissues. A–I: scale bar = 100 µm, J–L: scale bar = 50 µm.</p

Details of the two NDV isolates investigated in this study.

a<p>Mean death time in embryonating eggs (hours) (<60: velogen; 60–90: mesogen; >90: lentogen).</p>b<p>Intracerebral pathogenicity index in day-old chicks (1.5–2.0: velogen; 1.0–1.5: mesogen; <0.5: lentogen).</p

Percentage survival (A) and sero-conversion at 14 dpi (B) of ducks after inoculation with SD09 or GD09-2 velogenic NDVs.

<p>Percentage survival (A) and sero-conversion at 14 dpi (B) of ducks after inoculation with SD09 or GD09-2 velogenic NDVs.</p

Primers used in the study.

<p>Primers used in the study.</p