Temperature sensitive nanogel-stabilized pickering emulsion of fluoroalkane for ultrasound guiding vascular embolization therapy.

Various X-ray imaging technologies like computed tomography (CT) and digital subtraction angiography (DSA) are widely used in transcatheter arterial embolization (TAE) therapy for treating hepatocellular cancer (HCC) patients. Although they display high-contrast imaging, they have a few disadvantages, such as complex operation and exposure to ionizing radiation. Thus, ultrasound (US) imaging plays an important role in medical diagnosis because of its advantages, like simple and fast operation, no ionizing radiation exposure, and accurate real-time imaging. Subsequently, Poly N-isopropylacrylamide-co-2,2,3,4,4,4-Hexafluorobutyl methacrylate (PNF) nanogels were synthesized for stabilizing TGFPE, the Pickering emulsions of 2H, 3H-decafluoropentane (HDFP). These emulsions displayed dual abilities of thermosensitive sol-gel transition and long-term US imaging in vitro. Thus, it was concluded that these emulsions could achieve vascular embolization and long-term US imaging in vivo as per the TAE animal model results. The emulsion droplets' flow and accumulation were visualized under the US imaging guidance. In summary, the Pickering emulsions have the potential to be used as US-guided embolization material for mediating TAE surgeries.

Effect of Wet-Dry Cycles on the Mechanical Performances and Microstructure of Pisha Sandstone.

The effects of the wet-dry cycles on the chemical compositions, microstructure, and mechanical properties of Pisha sandstone were experimentally investigated in the current study. A series of uniaxial compression tests were conducted to validate the deterioration of the mechanical property of specimens after wet-dry cycles. In addition, the evolutions of the mineral compositions and microstructure characteristics were confirmed by X-ray diffraction (XRD) and scanning electron microscope (SEM). Experimental results indicated that with the increase of wet-dry cycles, the mechanical properties of Pisha sandstone gradually decrease. After five wet-dry cycles, the uniaxial compressive strength, elastic modulus, and fracture energy of specimens were reduced by 41.06%, 62.39%, and 31.92%, respectively. The failure mode of the specimen changes from inclined shear failure to peel failure. Compared to the initial specimens, the relative content of primary minerals after five wet-dry cycles declined by 5.94%, and the relative content of clay minerals after five wet-dry cycles increased by 54.33%. Additionally, the porosity of samples exhibits a positive correlation with wet-dry cycles. Compared to the initial specimens, the porosity of specimens after five wet-dry cycles increased by 176.32%. Finally, a prediction model of the correlation between uniaxial compressive strength and porosity is proposed and verified.

Selenium regulates the mitogen-activated protein kinase pathway to protect broilers from hexavalent chromium-induced kidney dysfunction and apoptosis.

Hexavalent chromium [Cr (VI)] is a common environmental pollutant. Although selenium (Se) can antagonize the toxicity of Cr (VI), the specific underlying mechanism has not been identified. To investigate this mechanism, we used potassium dichromate (K2Cr2O7) and selenium-rich yeast (SeY) to construct single Cr (VI)- and combined Se/Cr (VI)-exposed broiler models during a 42-day period. Broilers were randomly assigned to the control (C), SeY (Se), SeY + Cr (VI) (Se/Cr), and Cr (VI) (Cr) groups. The antagonistic mechanisms of Se and Cr (VI) were evaluated using histopathological evaluation, serum and tissue biochemical tests, real-time fluorescence quantitative polymerase chain reaction, and western blotting. The results suggested that Se alleviated the morphological and structural damage to renal tubules and glomeruli, while reducing the organ index, creatinine levels, and blood urea nitrogen levels in the kidneys of Cr (VI)-exposed broilers. Furthermore, Cr (VI) reduced the levels of superoxide dismutase and glutathione, and increased the levels of malondialdehyde, in broiler kidney tissues. However, Se alleviated Cr (VI)-induced oxidative stress by increasing the levels of superoxide dismutase and glutathione, and decreasing the levels of malondialdehyde, within a certain range. Compared to the C group, the levels of p38, JNK, p-p38, p-JNK, p-p38/p38, and p-JNK/JNK significantly increased, whereas those of ERK, p-ERK, and p-ERK/ERK decreased, in the Cr group. Compared to the Cr group, the levels of p38, JNK, p-p38, p-JNK, p-p38/p38, and p-JNK/JNK significantly decreased, whereas those of ERK, p-ERK, and p-ERK/ERK increased, in the Se/Cr group. Furthermore, the levels of p53, c-Myc, Bax, Cyt-c, caspase-9, and caspase-3 significantly increased, and those of Bcl-2 and Bcl-2/Bax significantly decreased, following Cr (VI) exposure, while Se restored the expression of these genes. In conclusion, our findings suggest that SeY can protect against Cr (VI)-induced dysfunction and apoptosis by regulating the mitogen-activated protein kinase pathway activated by oxidative stress in broiler kidney tissues.

Transcriptome Analysis of Dimorphic Fungus Sporothrix schenckii Exposed to Temperature Stress.

PURPOSE: Sporothrix schenckii is a thermally dimorphic fungus. In a saprotrophic environment or culturing at 25 °C, it grows as mycelia, whereas in host tissues or culturing at 37 °C, it undergoes dimorphic transition and division into pathogenic yeast cells. S. schenckii can cause serious disseminated sporotrichosis in immunocompromised hosts and presents an emerging global health problem. The mycelium-to-yeast transition was a consequence of the adaptive process to different environment. Some studies showed that the transition was significantly related to the virulence and pathogenesis of dimorphic fungi. However the genetic mechanisms of this complicated biological process are poorly understood. METHOD: Our study presented a comparative transcriptomic analysis perspective on temperature stress in a visceral isolates of S. schenckii, obtaining more genetic information related to dimorphic transition. RESULTS: The 9.38 Gbp dataset was generated and assembled into 14,423 unigenes. Compared with gene and protein databases, 9561 unigenes were annotated. Comparative analysis identified 1259 genes expressed differentially in mycelium and yeast phase, and were categorized into a number of important biological processes, such as synthesis and metabolism, transmembrane transport, biocatalysis, oxidation reduction, and cellular signal transduction. CONCLUSIONS: The findings suggested that temperature-dependent transition was tightly associated with stress adaptation, growth and development, signal regulation, adhesion, and colonization, which was predicted to be related with virulence and pathogenesis. Collection of these data should offer fine-scale insights into the mechanisms of dimorphism and pathogenesis of S. schenckii, and meanwhile facilitate the evolutionary and function studies of other dimorphic fungi.

Fe3O4@TiO2-Laden Neutrophils Activate Innate Immunity via Photosensitive Reactive Oxygen Species Release.

Although a variety of advanced sterilization materials and treatments have emerged, the complete elimination of bacterial infection, especially drug-resistant bacterial infection, remains an immense challenge. Here, we demonstrate the use of neutrophils loaded with photocatalytic nanoparticles to reduce bacterial infection. This method activates the immune system to achieve an anti-infection response. We prepared the photocatalytic nanoparticle-laden neutrophils in vivo through neutrophil phagocytosis. The resulting loaded cells retained the cell membrane functionality of the source cell, as well as the complete immune cell function of neutrophils, particularly the ability to recruit macrophages to the target area. Photocatalytic nanoparticle-laden neutrophils can target infection sites and release reactive oxygen species to induce the secretion of chemokines, leading to the targeted recruitment of macrophages and enhancing a powerful immune cascade. In a severe mouse infection model induced by pathogenic bacteria, small doses of photocatalytic nanoparticle-laden neutrophils showed a remarkable therapeutic effect by enhancing macrophage recruitment and the immune cascade.

Near-Infrared Light-Sensitive Nano Neuro-Immune Blocker Capsule Relieves Pain and Enhances the Innate Immune Response for Necrotizing Infection.

Sensory neurons promote profound suppressive effects on neutrophils during Streptococcus pyogenes infection and contribute to the pathogenesis of necrotizing infection ("flesh-eating disease"). Thus, the development of new antibacterial agents for necrotizing infection is promising because of the clear streptococcal neuro-immune communication. Herein, based on the immune escape membrane exterior and competitive membrane functions of the glioma cell membrane, a novel nano neuro-immune blocker capsule was designed to prevent neuronal activation and improve neutrophil immune responses for necrotizing infection. These nano neuro-immune blockers could neutralize streptolysin S, suppress neuron pain conduction and calcitonin gene-related peptide release, and recruit neutrophils to the infection site, providing a strong therapeutic effect against necrotizing infection. Furthermore, nano neuro-immune blockers could serve as an effective inflammatory regulator and antibacterial agent via photothermal effects under near-infrared irradiation. In the Streptococcus pyogenes-induced necrotizing fasciitis mouse model, nano neuro-immune blockers showed significant therapeutic efficacy by ameliorating sensitivity to pain and promoting the antibacterial effect of neutrophils.

Photoactivated Trifunctional Platinum Nanobiotics for Precise Synergism of Multiple Antibacterial Modes.

Integrating multiple strategies of antibacterial mechanisms into one has been proven to have tremendous promise for improving antimicrobial efficiency. Hence, dual-valent platinum nanoparticles (dvPtNPs) with a zero-valent platinum core (Pt0 ) and bi-valent platinum shell (Pt2+ ions), combining photothermal and photodynamic therapy, together with "chemotherapy," emerge as spatiotemporally light-activatable platinum nano-antibiotics. Under near-infrared (NIR) exposure, the multiple antibacterial modes of dvPtNPs are triggered. The Pt0 core reveals significant hyperthermia via effective photothermal conversion while an immediate release of chemotherapeutic Pt2+ ions occurs through hyperthermia-initiated destabilization of metallic interactions, together with reactive oxygen species (ROS) level increase, thereby resulting in synergistic antibacterial effects. The precise cooperative effects between photothermal, photodynamic, and Pt2+ antibacterial effects are achieved on both Gram-negative Escherichia coli and Gram-positive methicillin-resistant Staphylococcus aureus, where bacterial viability and colony-forming units are significantly reduced. Moreover, similar results are observed in mice subcutaneous abscess models. Significantly, after NIR treatment, dvPtNP exhibits a more robust bacteria-killing efficiency than other PtNP groups, owing to its integration of dramatic damage to the bacterial membrane and DNA, and alteration to ATP and ROS metabolism. This study broadens the avenues for designing and synthesizing antibacterial materials with higher efficiency.

Stat3-Atg5 signal axis inducing autophagy to alleviate hepatic ischemia-reperfusion injury.

In performing our experiment, impaired autophagy increased hepatocellular damage during the reperfusion period. It was demonstrated by the effect of blocking autophagy using bafilomycin A1 or knocking Atg5 gene out reduces the anti-apoptotic effect of Stat3. Here we focus on the role of signal transducer and activator of transcription 3 (Stat3) in regulating autophagy to alleviate hepatic IRI. We found that Stat3 was up-regulated during hepatic IRI and was associated with an activation of the autophagic signaling pathway. This increased Stat3 expression, which was allied with high autophagic activity, alleviated liver damage to IR, an effect which was abrogated by Stat3 epletion as demonstrated in both in vivo and in vitro methods. The levels of Atg5 protein were decreased when Stat3 was inhibited by HO 3867 or siStat3. We conclude that Stat3 appeared to exert a pivotal role in hepatic IRI, by activating autophagy to alleviate hepatic IRI, and Atg5 was required for this process. The identification of this novel pathway, that links expression levels of Stat3 with Atg5-mediated autophagy, may provide new insights for the generation of novel protective therapies directed against hepatic IRI.

Enhanced replication of avian-origin H3N2 canine influenza virus in eggs, cell cultures and mice by a two-amino acid insertion in neuraminidase stalk.

Canine influenza virus (CIV) is a newly identified, highly contagious respiratory pathogen in dogs. Recent studies indicate that avian-origin H3N2 CIV are circulating in Chinese dogs. To investigate the effects of a two-amino acid (2-aa) insertion naturally occurring at the distal end of the neuraminidase (NA) stalk found in Chinese isolates since 2010 on virus replication and virulence, we rescued the CIV strain, A/canine/Jiangsu/06/2011(H3N2) and its NA mutant without the 2-aa insertion using reverse genetics. The NA stalk length affected virus growth in cell culture. Compared to the short stalk strain (without 2-aa insertion), the long stalk strain (with 2-aa insertion) exhibited higher peak titers and greater yields in Madin-Darby canine kidney (MDCK) cells, chicken embryo fibroblasts and canine bronchiolar epithelial cells, as well as much larger plaques in MDCK cell monolayers. Furthermore, mice inoculated with the long stalk strain showed more severe pathologic damage in lung and higher proportion of detectable viral RNA in tissues. The long stalk strain induced local IFN-γ production with faster kinetics and higher levels in mice. However, in chickens, the two viral strains showed no significant difference with nearly the same proportion of detectable viral RNA loads in tissues. These observations suggest that the 2-aa insertion in the NA stalk acquired by avian-origin H3N2 CIV helps to enhance viral replication and is likely a result of adaptive evolution in canine hosts.

Canine influenza virus coinfection with Staphylococcus pseudintermedius enhances bacterial colonization, virus load and clinical presentation in mice.

BACKGROUND: Canine influenza virus (CIV) and Staphylococcus pseudintermedius (Sp) are pathogens that cause respiratory disease in dogs. Considering bacterial infections following influenza are a leading cause of illness and death, it is of particular meaning to investigate the interaction between these two pathogens. In this study, BALB/c mice were used as a mouse model to assess whether inoculation with CIV H3N2 followed by S. pseudintermedius 72 h later resulted in exacerbation of disease. Disease was characterized by assessment of body weight loss, titration of virus and bacteria, histopathology, and cytokine production. RESULTS: There was a significantly greater decrease in body weight in the co-infected group compared with the CIV-only and SP-only groups. CIV inoculation increased bacterial colonization, whereas secondary infection with S. pseudintermedius elevated the viral RNA load of CIV in tissues. The histological lesions in the brain, spleen and lung were more severe in the CIV/Sp group than in the singly treated groups. Infection with CIV alone, Sp alone or coinfection stimulated a significantly higher release of cytokines, such as interferon-gamma (IFN)-γ, interleukin 6 (IL)-6, tumor necrosis factor (TNF-α) and lymphotactin (Lptn), than was observed in the mock-infected group (PBS). Moreover, the levels of IFN-γ in the spleen and lung were higher in the CIV/Sp group compared with the CIV-only and Sp-only groups. CONCLUSION: Our findings provide the first demonstration that the secondary infection of mice with Sp leads to increased clinical signs and lesions during canine influenza.

Hydrophilicity/Hydrophobicity reversable and redox-sensitive nanogels for anticancer drug delivery.

Long circulation in the blood, efficient cellular internalization, and intracellular drug release in the tumor cells are major challenges in the development of ideal anticancer drug delivery systems. In this paper, hydrophilicity/hydrophobicity reversable and redox-sensitive poly(oligo(ethylene glycol) methacrylates-ss-acrylic acid) (P(OEGMAs-ss-AA)) nanogels were constructed as drug carriers for cancer therapy. The nanogels underwent a pH-dependent hydrophilic/hydrophobic change. The nanogels were hydrophilic under physiological conditions (pH 7.4, 37 °C), resulting in fewer opsonization of proteins and less phagocytosis by macrophage RAW264.7 cells, while they were hydrophobic in the tumor tissues (pH 6.5, 37 °C), resulting in strong internalization by Bel7402 cells. The doxorubicin (DOX) release from DOX-loaded nanogels was increased in intracellular reductive and lysosome acidic environments. DOX-loaded nanogels exhibited higher cellular proliferation inhibition to GSH-OEt-pretreated Bel7402 cells at pH 6.5 than to unpretreated cells at pH 7.4. Further studies showed that the loaded DOX and nanogels were internalized into the cells together via both lipid raft/caveolae- and clathrin-mediated endocytic pathways. After internalization, the DOX-loaded nanogels were transported via the specific route in endo/lysosomal system. The loaded DOX was released from the nanogels with the introduction of intracellular GSH and entered the nucleus. This study indicated that the hydrophilicity/hydrophobicity reversable and redox-sensitive nanogels might be used as potential carriers for anticancer drugs, which provided a foundation for designing an effective drug delivery system for cancer therapy.

Monoclonal antibody specific to HA2 glycopeptide protects mice from H3N2 influenza virus infection.

Canine influenza virus (CIV) subtype H3N2 is a newly identified, highly contagious respiratory pathogen that causes cough, pneumonia and other respiratory symptoms in dogs. Data indicate that the virus is responsible for recent clinical cases of dog disease in China. However, therapeutic options for this disease are very limited. In this study, seven monoclonal antibodies (mAbs) against CIV JS/10 (an H3N2 subtype virus) were produced and characterized. Among them, mAb D7, which is specific for the HA2 glycopeptide (gp), induced the highest neutralization titers. The protection provided by mAb D7 was evaluated in BALB/c mice challenged with homologous or heterologous strains of H3N2 influenza virus, including two strains of CIV and one strain of swine influenza virus (SIV). The data show that mAb D7 protected the mice from infection with the three viral strains, especially the homologous strain, which was indicated by the recovery of body weight, reduction of viral load, and reduction of tissue damage. Moreover, the levels of IFN-γ and TNF-α in the lungs, as detected by ELISA, were reduced in the infected mice treated with the mAb D7 compared with those without mAb D7 treatment. Thus, our findings demonstrate, for the first time, that a mAb could reduce the release of IFN-γ and TNF-α associated with tissue damage by CIV infection and that the mAb might be of great therapeutic value for CIV infection.

Establishment and characterization of a telomerase-immortalized canine bronchiolar epithelial cell line.

Dogs are susceptible to infectious diseases that occur primarily in the respiratory tract. The airway epithelium acts as a first line of defense and is constantly exposed to microorganisms present in the environment. Respiratory epithelial cells have recently gained wide use as a cell model for studying the pathogenesis of human, murine or swine respiratory pathogen infections. However, studies of the pathogenic mechanisms of canine pathogens have been hindered by the lack of reliable respiratory cell lines. Here, we cultured primary canine bronchiolar epithelial cells (CBECs), whose characteristics were confirmed by their expression of the epithelial cell-specific marker cytokeratin 18, and have provided protocols for their isolation and ex vivo expansion. Further, we established immortalized CBECs containing the human telomerase reverse transcriptase (hTERT) gene via transfection of primary CBECs with the recombinant plasmid pEGFP-hTERT. Immortalized bronchiolar epithelial cells (hTERT-CBECs) retain the morphological and functional features of primary CBECs, as indicated by reverse transcriptase polymerase chain reaction, proliferation assays, karyotype analysis, telomerase activity assay, and Western blotting, which demonstrate that hTERT-CBECs have higher telomerase activity, an extended proliferative lifespan, and a diploid complement of chromosomes, even after Passage 50. Moreover, this cell line is not transformed, as evaluated using soft agar assays and tumorigenicity analysis in nude mice, and can therefore be safely used in future studies. The isolation and establishment of stable hTERT-CBECs is of great importance for use as an in vitro model for mechanistic studies of canine pathogenic infections.

High-Throughput Analytical Techniques for Multiresidue, Multiclass Determination of 653 Pesticides and Chemical Pollutants in Tea-Part IV: Evaluation of the Ruggedness of the Method, Error Analysis, and Key Control Points of the Method.

A 3 month study was conducted on the ruggedness of a multiresidue method for accuracy and stability. The results indicate that in terms of Youden pair ratios of 201 pesticide aged tea samples falling approximately within 1.00-1.20 of the ratio of theoretical spraying concentrations, the differences do not exceed 5% for percentages made up by ratios of the fixed values obtained by two kinds of instruments for two teas and those made up by 18 circular determinations. However, regarding two kinds of SPE cartridges, the Cleanert TPT cartridge is higher than the ENVI-CARB+primary secondary amine (PSA) cartridge by 10%. Pertaining to RSD values of "parallel samples" and whether it is green tea or Woolong tea, the percentages of RSD≤15% values of the parallel samples all exceed 88%. Whether it is the first or circular determination for two teas and analytical results from two kinds of instruments, the percentages of RSD≤15% values have a difference of less than 6%, while the TPT cartridge is better than ENVI-CARB+PSA by above 6% for the two cartridges. Concerning RSDs of Youden pair ratios, RSD≤15% values have a proportion exceeding 85% for both green tea and Woolong tea, and the percentage is greater than 87% whether it is for two kinds of SPE cartridges or two kinds of instruments. In terms of Youden pair ratios and the classified statistical analysis of the ruggedness data of parallel samples, the proportion of RSD≤15% values of Youden pair ratios is 8% higher for the TPT cartridge than the ENVI-CARB+PSA cartridge; the proportion of RSD≤15% values of parallel samples is 6.2% higher for the TPT cartridge than the ENVI-CARB+PSA cartridge. Data show no marked differences for two teas and two kinds of instruments. A comparison of the aforementioned aspects finds that good ruggedness was obtained with both SPE cleanup methods, and the results from the TPT cartridge are better than those from the ENVI-CARB+PSA cartridge.

Distinct brain activity in processing negative pictures of animals and objects - the role of human contexts.

Previous studies have shown that the amygdala is important in processing not only animate entities but also social information. It remains to be determined to what extent the factors of category and social context interact to modulate the activities of the amygdala and cortical regions. In this study, pictures depicting animals and inanimate objects in negative and neutral levels were presented. The contexts of the pictures differed in whether they included human/human parts. The factors of valence, arousal, familiarity and complexity of pictures were controlled across categories. The results showed that the amygdala activity was modulated by category and contextual information. Under the nonhuman context condition, the amygdala responded more to animals than objects for both negative and neutral pictures. In contrast, under the human context condition, the amygdala showed stronger activity for negative objects than animals. In addition to cortical regions related to object action, functional and effective connectivity analyses showed that the anterior prefrontal cortex interacted more with the amygdala for negative objects (vs. animals) in the human context condition, by a top-down modulation of the anterior prefrontal cortex to the amygdala. These results highlighted the effects of category and human contexts on modulating brain activity in emotional processing.

Solid self-emulsifying casein carrier for the improvement on the oral bioavailability of simvastatin.

Simvastatin (SV) is a statin drug that can effectively control cholesterol and prevent cardiovascular diseases. However, SV is water-insoluble, and poor oral bioavailability (<5 %). Solid self-emulsifying carrier system is more stable than liquid emulsions, facilitating to improve the solubility and bioavailability of poorly soluble drugs. In the present study, a solid self-emulsifying carrier stabilized by casein (Cas-SSE) was successfully used to load SV to improve its solubility in water, by formulation selection and emulsification process optimization. Compared with oral tablets, the release of SV from Cas-SSE was significantly enhanced in artificial intestinal fluid. Furthermore, everted gut sac experiments indicated some water-soluble dispersing agents such as hydroxyethyl starch (HES), were not conducive to drug absorption. Pharmacokinetic studies suggested Cas-SSE without dispersing agent has much higher relative bioavailability (184.1 % of SV and 284.5 % of simvastatin acid) than SV tablet. The present work suggests Cas-SSE is a promising drug delivery platform with good biocompatibility for improving oral bioavailability of poorly water-soluble drugs.

Characterization of Chitosan-Gallic Acid Graft Copolymer for Periodontal Dressing Hydrogel Application.

The postoperative periodontal wound is in a complex physiological environment; the bacteria accumulation, the saliva stimulation, and the food residues retention will aggravate the wound deterioration. Commercial periodontal dressings have been widely used for postoperative periodontal treatment, and there still exists some problems, such as poor biocompatibility, weak adhesion, insufficient antibacterial, and anti-inflammatory properties. In this study, a chitosan-gallic acid graft copolymer (CS-GA) is synthesized as a potential periodontal dressing hydrogel. CS-GA possesses high swelling rate, adjustable degradability, self-healing ability, biocompatibility, strong adhesion ability, high mechanical properties and toughness. Furthermore, CS-GA has good scavenging ability for ·OH, O2 - , and 1 O2. And CS-GA has good inhibition effect on different bacterial through bacterial membranes damage. CS-GA can stop bleeding in a short time and adsorb erythrocytes to form physical blood clots to enhance the hemostatic performance. In addition, CS-GA can reduce inflammatory factors expressions, increase collagen fibers deposition, and neovascularization to promote wounds healing, which makes it as a potential periodontal dressing for postoperative tissue restoration.

Complete genome sequence of an H3N2 canine influenza virus from dogs in Jiangsu, China.

A canine influenza virus (CIV) strain of avian origin designated A/Canine/Jiangsu/06/2010 (H3N2) was isolated from dogs exhibiting severe respiratory disease in Jiangsu, China. We announce the complete genome sequence of this viral strain and report major findings from the genomic analysis. This sequence will help us understand the molecular characteristics and evolutionary of H3N2 CIV in China.

Genotyping and pathobiologic characterization of canine parvovirus circulating in Nanjing, China.

BACKGROUND: Canine parvovirus (CPV) is an important pathogen that causes acute enteric disease in dogs. It has mutated and spread throughout the world in dog populations. We provide an update on the molecular characterization of CPV that circulated in Nanjing, a provincial capital in China between 2009 and 2012. RESULTS: Seventy rectal swab samples were collected from the dogs diagnosed with CPV infection in 8 animal hospitals of Nanjing. Sequence analysis of VP2 genes of 31 samples revealed that 29 viral strains belonged to CPV-2a subtype, while other two strains were classified into CPV-2b. To investigate the pathogenicity of the prevalent virus, we isolated CPV-2a and performed the animal experiment. Nine beagles were inoculated with 105.86 of 50% tissue culture infectious doses (TCID50) of the virus. All the experimentally infected beagles exhibited mild to moderate mucoid or watery diarrhea on day 4 post-infection (p.i.). On day 9 p.i., characteristic histopathological lesions were clearly observed in multiple organs of infected dogs, including liver, spleen, kidney, brain and all segments of the small and large intestines, while viral DNA and antigen staining could be detected in the sampled tissues. It is notable that canine parvovirus was isolated in one from two brain samples processed. CONCLUSION: Our results indicated that CPV-2a is the predominant subtype in Nanjing of China. And this virus caused extensive lesions in a variety of tissues, including the brain.

Thermoresponsive bacterial cellulose whisker/poly(NIPAM-co-BMA) nanogel complexes: synthesis, characterization, and biological evaluation.

Dispersions of poly(N-isopropylacrylamide-co-butyl methacrylate) (PNB) nanogels are known to exhibit reversible thermosensitive sol-gel phase behavior and can consequently be used in a wide range of biomedical applications. However, some dissatisfactory mechanical properties of PNB nanogels can limit their applications. In this paper, bacterial cellulose (BC) whiskers were first prepared by sulfuric acid hydrolysis and then nanosized by high-pressure homogenization for subsequent use in the preparation of BC whisker/PNB nanogel complexes (designated as BC/PNB). The mechanical properties of PNB was successfully enhanced, resulting in good biosafety. The BC/PNB nanogel dispersions exhibited phase transitions from swollen gel to shrunken gel with increasing temperature. In addition, differential scanning calorimetry (DSC) data showed that the thermosensitivity of PNB nanogels was retained. Rheological tests also indicated that BC/PNB nanogel complexes had stronger gel strengths when compared with PNB nanogels. The concentrated dispersions showed shear thinning behavior and improved toughness, both of which can play a key role in the medical applications of nanogel complexes. Furthermore, the BC/PNB nanogel complexes were noncytotoxic according to cytotoxicity and hemolysis tests. Concentrated BC/PNB nanogel dispersion displayed gel a forming capacity in situ by catheter injection, which indicates potential for a wide range of medical applications.