Microarray analysis of tRNA-derived small RNA (tsRNA) in LPS-challenged macrophages treated with metformin

Metformin, a widely used anti-diabetic drug, has demonstrated its efficacy in addressing various inflammatory conditions. tRNA-derived small RNA (tsRNA), a novel type of small non-coding RNA, exhibits diverse regulatory functions and holds promise as both a diagnostic biomarker and a therapeutic target for various diseases. The purpose of this study is to investigate whether the abundance of tsRNAs changed in LPS versus LPS + metformin-treated cells, utilizing microarray technology. Firstly, we established an in vitro lipopolysaccharide (LPS)-induced inflammation model using RAW264.7 macrophages and assessed the protective effects of metformin against inflammatory damage. Subsequently, we extracted total RNA from both LPS-treated and metformin + LPS-treated cell samples for microarray analysis to identify differentially abundant tsRNAs (DA-tsRNAs). Furthermore, we conducted bioinformatics analysis to predict target genes for validated DA-tsRNAs and explore the biological functions and signaling pathways associated with DA-tsRNAs. Notably, metformin was found to inhibit the inflammatory response in RAW264.7 macrophages. The microarray results revealed a total of 247 DA-tsRNAs, with 58 upregulated and 189 downregulated tsRNAs in the Met + LPS group compared to the LPS group. The tsRNA-mRNA network was visualized, shedding light on potential interactions. The results of bioinformatics analysis suggested that these potential targets of specific tsRNAs were mainly related to inflammation and immunity. Our study provides compelling evidence that metformin exerts anti-inflammatory effects and modulates the abundance of tsRNAs in LPS-treated RAW264.7 macrophages. These findings establish a valuable foundation for using tsRNAs as potential biomarkers for metformin in the treatment of inflammatory conditions.

The Role and Mechanism of Metformin in Inflammatory Diseases

Metformin is a classical drug used to treat type 2 diabetes. With the development of research on metformin, it has been found that metformin also has several advantages aside from its hypoglycemic effect, such as anti-inflammatory, anti-aging, anti-cancer, improving intestinal flora, and other effects. The prevention of inflammation is critical because chronic inflammation is associated with numerous diseases of considerable public health. Therefore, there has been growing interest in the role of metformin in treating various inflammatory conditions. However, the precise anti-inflammatory mechanisms of metformin were inconsistent in the reported studies. Thus, this review aims to summarize various currently known possible mechanisms of metformin involved in inflammatory diseases and provide references for the clinical application of metformin.

Iodine-Doped 3D Print Ti Alloy for Antibacterial Therapy on Orthopedic Implants

This study presents a novel approach to mitigating bacterial infections and antibiotic resistance in medical implants through the integration of iodine-doping and 3D printing techniques. Iodine, with its potent antibacterial properties, and titanium alloy (Ti), a popular metal for implants due to its mechanical and biological properties, were combined via electrodeposition on 3D-printed titanium alloy (3D-Ti) implants. Scanning electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy confirmed the successful creation of iodine-doped titanium implants with improved iodine content due to the rough surface of the 3D-printed material. In vitro studies revealed that these implants significantly inhibited bacterial adhesion and biofilm formation and showed favorable release kinetics for iodine ions. Biocompatibility tests demonstrated no cytotoxic effects and good hemocompatibility. The implants demonstrated enhanced antimicrobial efficacy against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) bacteria strains. The findings imply that the integration of iodine-doping and 3D printing technologies is a promising strategy for treating postoperative infections associated with medical implants, consequently bettering the prognosis for patients. Future investigations are encouraged to delve into the long-standing impacts and prospective clinical utility of this groundbreaking methodology.

Homogeneous silver nanoparticle loaded polydopamine/polyethyleneimine-coated bacterial cellulose nanofibers for wound dressing

Utilizing mussel-inspired chemistry is an advanced strategy for surface modification, because dopamine (DA) can form a material-independent adhesive coating and further functionalization can be achieved, including the production of silver nanoparticles (AgNPs). Nevertheless, DA easily aggregates in the nanofiber network structure of bacterial cellulose (BC), which not only blocks the pores in the BC structure but also leads to the formation of large silver particles and the burst release of highly cytotoxic silver ions. Herein, a homogeneous AgNP-loaded polydopamine (PDA)/polyethyleneimine (PEI) coated BC was constructed via a Michael reaction between PDA and PEI. Under the action of PEI, the PDA/PEI coating was uniformly attached to the BC fiber surface with a thickness of approximately 4 nm, and homogeneous AgNPs were produced on the uniform PDA/PEI/BC (PPBC) fiber surface. The sustained release of silver ions was better from AgNPs@PPBC than from AgNPs@PDA/BC. The obtained AgNPs@PPBC exhibited excellent antibacterial activities and cytocompatibility. The results of the in vivo assay indicated that the AgNPs@PPBC dressing could inhibit S. aureus infection and inflammation, promote hair follicle growth, enhance collagen deposition, and accelerate wound healing within 12 days compared with BC. These results illustrate that the homogeneous AgNPs@PPBC dressing has great potential for treating infected wounds.

A dual functional Ti-Ga alloy: inhibiting biofilm formation and osteoclastogenesis differentiation via disturbing iron metabolism

BACKGROUND

Although biomedical implants have been widely used in orthopedic treatments, two major clinical challenges remain to be solved, one is the bacterial infection resulting in biofilm formation, and the other is aseptic loosening during implantation due to over-activated osteoclastogenesis. These factors can cause many clinical issues and even lead to implant failure. Thus, it is necessary to endow implants with antibiofilm and aseptic loosening-prevention properties, to facilitate the integration between implants and bone tissues for successful implantation. To achieve this goal, this study aimed to develop a biocompatible titanium alloy with antibiofilm and anti-aseptic loosening dual function by utilizing gallium (Ga) as a component.

METHODS

A series of Ti-Ga alloys were prepared. We examined the Ga content, Ga distribution, hardness, tensile strength, biocompatibility, and anti-biofilm performance in vitro and in vivo. We also explored how Ga³⁺ ions inhibited the biofilm formation of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) and osteoclast differentiation.

RESULTS

The alloy exhibited outstanding antibiofilm properties against both S. aureus and E. coli in vitro and decent antibiofilm performance against S. aureus in vivo. The proteomics results demonstrated that Ga³⁺ ions could disturb the bacterial Fe metabolism of both S. aureus and E. coli, inhibiting bacterial biofilm formation. In addition, Ti-Ga alloys could inhibit receptor activator of nuclear factor-κB ligand (RANKL)-dependent osteoclast differentiation and function by targeting iron metabolism, then suppressing the activation of the NF-κB signaling pathway, thus, showing their potential to prevent aseptic loosening.

CONCLUSION

This study provides an advanced Ti-Ga alloy that can be used as a promising orthopedic implant raw material for various clinical scenarios. This work also revealed that iron metabolism is the common target of Ga³⁺ ions to inhibit biofilm formation and osteoclast differentiation.

Fabrication of gentamicin loaded Col-I/HA multilayers modified titanium coatings for prevention of implant infection

In this study, gentamicin loaded collagen I/hyaluronic acid multilayers modified titanium coating (TC-AA(C/H)6-G) was fabricated via a layer-by-layer (LBL) covalent immobilization method. The drug releasing properties of collagen I/Hyaluronic acid (Col-I/HA) multilayers and the effect of loaded gentamicin on the antibacterial properties and cytocompatibility of modified TC were investigated. The gentamicin release assay indicated that the Col-I/HA multilayers modified TC exhibited agreeable drug-loading amount (537.22 ± 29.66 µg of gentamicin) and controlled-release performance (240 h of sustained release time). TC-AA(C/H)6-G revealed satisfactory antibacterial activity and inhibited the colonization and biofilm formation of S. aureus. Fortunately, the functions of hMSCs on TC-AA(C/H)6-G did not affected by the loaded gentamicin, and TC-AA(C/H)6-G could improve the adhesion, proliferation and osteogenic differentiation of cells, as well as TC-AA(C/H)6. In vivo animal study indicated that TC-AA(C/H)6-G could effectively control intramedullary cavity infection caused by S. aureus and prevent bone destruction.

Rational Design of All-Organic Nanoplatform for Highly Efficient MR/NIR-II Imaging-Guided Cancer Phototheranostics

Organic theranostic nanomedicine has precision multimodel imaging capability and concurrent therapeutics under noninvasive imaging guidance. However, the rational design of desirable multifunctional organic theranostics for cancer remains challenging. Rational engineering of organic semiconducting nanomaterials has revealed great potential for cancer theranostics largely owing to their intrinsic diversified biophotonics, easy fabrication of multimodel imaging platform, and desirable biocompatibility. Herein, a novel all-organic nanotheranostic platform (TPATQ-PNP NPs) is developed by exploiting the self-assembly of a semiconducting small molecule (TPATQ) and a new synthetic high-density nitroxide radical-based amphiphilic polymer (PNP). The nitroxide radicals act as metal-free magnetic resonance imaging agent through shortened longitudinal relaxation times, and the semiconducting molecules enable ultralow background second near-infrared (NIR-II, 1000-1700 nm) fluorescence imaging. The as-prepared TPATQ-PNP NPs can light up whole blood vessels of mice and show precision tumor-locating ability with synergistic (MR/NIR-II) imaging modalities. The semiconducting molecules also undergo highly effective photothermal conversion in the NIR region for cancer photothermal therapy guided by complementary tumor diagnosis. The designed multifunctional organic semiconducting self-assembly provides new insights into the development of a new platform for cancer theranostics.

Optimized Nanointerface Engineering of Micro/Nanostructured Titanium Implants to Enhance Cell-Nanotopography Interactions and Osseointegration

The success of orthopedic implants requires rapid and complete osseointegration which relies on an implant surface with optimal features. To enhance cellular function in response to the implant surface, micro- and nanoscale topography have been suggested as essential. The aim of this study was to identify an optimized Ti nanostructure and to introduce it onto a titanium plasma-sprayed titanium implant (denoted NTPS-Ti) to confer enhanced immunomodulatory properties for optimal osseointegration. To this end, three types of titania nanostructures, namely, nanowires, nanonests, and nanoflakes, were achieved on hydrothermally prepared Ti substrates. The nanowire surface modulated protein conformation and directed integrin binding and specificity in such a way as to augment the osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and induce a desirable osteoimmune response of RAW264.7 macrophages. In a coculture system, BMSCs on the optimized micro/nanosurface exerted enhanced effects on nonactivated or lipopolysaccharide-stimulated macrophages, causing them to adopt a less inflammatory macrophage profile. The enhanced immunomodulatory properties of BMSCs grown on NTPS-Ti depended on a ROCK-medicated cyclooxygenase-2 (COX2) pathway to increase prostaglandin E2 (PGE2) production, as evidenced by decreased production of PGE2 and concurrent inhibition of immunomodulatory properties after treatment with ROCK or COX2 inhibitors. In vivo evaluation showed that the NTPS-Ti implant resulted in enhanced osseointegration compared with the TPS-Ti and Ti implants. The results obtained in our study may provide a prospective approach for enhancing osseointegration and supporting the application of micro/nanostructured Ti implants.

Improved antibacterial properties of collagen I/hyaluronic acid/quaternized chitosan multilayer modified titanium coatings with both contact-killing and release-killing functions

The HACC-based multilayer could inhibit the colonization of bacteria via contact-killing and release-killing.

Morphological analysis and quantitative evaluation of myopic maculopathy by three-dimensional magnetic resonance imaging

PurposeTo study the characteristic morphology and quantitatively evaluate the eye shape in different types of myopic maculopathy.MethodsA total of 103 eyes from 65 patients with high myopic maculopathy were examined by spectral-domain optical coherence tomography (SD-OCT) and three-dimensional magnetic resonance imaging (3D MRI). The participants were classified into two groups, namely myopic traction maculopathy (MTM) eyes and non-MTM eyes, with SD-OCT imaging. Volume renderings and morphology analysis of the 3D MRI of the eyeball were obtained. Quantitative analysis was achieved in the calculation of vitreous volume and the three-dimensional diameters of the eyeball in three cardinal axes. The eye shape distribution and the diameters of the eyeball were compared between the two groups. Eye shape distribution, vitreous volume, and eyeball diameter were compared between MTM and non-MTM eyes.ResultsThe MTM and non-MTM groups had a total of 68 and 35 eyes, respectively. A significant difference was found in the eye shape distribution (P<0.0001) between MTM and non-MTM eyes. Most of the MTM eyes had undergone a non-uniform expansion of the eyeball, whereas the non-MTM eyes had expanded uniformly. There was no significant difference (P>0.05) in either vitreous volume or other diameters between the two groups.ConclusionsNon-uniform globe expansion and staphyloma formation might play an important role in the pathogenesis of MTM.

Preparation of oriented bacterial cellulose nanofibers by flowing medium-assisted biosynthesis and influence of flowing velocity

Nanofiber alignment in tissue engineering scaffolds is a crucial factor controlling the cell behavior. In this work, we report a facile approach to obtain aligned nanofibers of bacterial cellulose (BC) by forcing the culture medium of bacteria to flow along a fixed direction. The emphasis of this work was placed on the effect of flowing velocity on the alignment of the as-prepared oriented BC (OBC). X-ray diffraction (XRD) and Fourier transform infrared (FTIR) analyses indicated that the velocity affected the crystallinity and thermal stability of BC while the chemical structure did not change with the velocity. The controllable alignment of BC nanofibers makes them a promising material for the construction of biomimetic scaffolds for tissue engineering and regenerative medicine.

Preparation, structural characterization, and in vitro cell studies of three-dimensional SiO2-CaO binary glass scaffolds built ofultra-small nanofibers

Three-dimensional (3D) nanofibrous scaffolds hold great promises in tissue engineering and regenerative medicine. In this work, for the first time, 3D SiO₂-CaO binary glass nanofibrous scaffolds have been fabricated via a combined method of template-assisted sol-gel and calcination by using bacterial cellulose as the template. SEM with EDS, TEM, and AFM confirm that the molar ratio of Ca to Si and fiber diameter of the resultant SiO₂-CaO nanofibers can be controlled by immersion time in the solution of tetraethyl orthosilicate and ethanol. The optimal immersion time was 6h which produced the SiO₂-CaO binary glass containing 60at.% Si and 40at.% Ca (named 60S40C). The fiber diameter of 60S40C scaffold is as small as 29nm. In addition, the scaffold has highly porous 3D nanostructure with dominant mesopores at 10.6nm and macropores at 20μm as well as a large BET surface area (240.9m²g^-1), which endow the 60S40C scaffold excellent biocompatibility and high ALP activity as revealed by cell studies using osteoblast cells. These results suggest that the 60S40C scaffold has great potential in bone tissue regeneration.

The synergistic effect of type I collagen and hyaluronic acid on the biological properties of Col/HA-multilayer-modified titanium coatings: an in vitro and in vivo study

The synergistic effect on osseointegration is existed between Type I collagen (ColI) and hyaluronic acid (HA), and the early osseogenetic activity of ColI/HA multilayer modified titanium coatings (TC) is higher than that ColI modified TC and HA modified TC.

Anti-infective efficacy, cytocompatibility and biocompatibility of a 3D-printed osteoconductive composite scaffold functionalized with quaternized chitosan

Contaminated or infected bone defects remain serious challenges in clinical trauma and orthopaedics, and a bone substitute with both osteoconductivity and antibacterial properties represents an improvement for treatment strategy. In this study, quaternized chitosan (hydroxypropyltrimethyl ammonium chloride chitosan, HACC) was grafted to 3D-printed scaffolds composed of polylactide-co-glycolide (PLGA) and hydroxyapatite (HA), in order to design bone engineering scaffolds endowed with antibacterial and osteoconductive properties. We found that both the PLGA/HA/HACC and PLGA/HACC composite scaffolds decreased bacterial adhesion and biofilm formation under in vitro and in vivo conditions. Additionally, ATP leakage assay indicated that immobilizing HACC on the scaffolds could effectively disrupt microbial membranes. Using human bone marrow-derived mesenchymal stem cells (hBMSCs), we demonstrated that HA incorporated scaffolds, including PLGA/HA and PLGA/HA/HACC, favoured cell attachment, proliferation, spreading and osteogenic differentiation compared to HA-free PLGA or PLGA/HACC scaffolds. Finally, an in vivo biocompatibility assay conducted on rats, showed that HA incorporated scaffolds (including PLGA/HA and PLGA/HA/HACC scaffolds) exhibited good neovascularization and tissue integration. Taken together, our findings support the approach for developing porous PLGA/HA/HACC composite scaffold with potential clinical application in the treatment of infected bone.

STATEMENT OF SIGNIFICANCE

Although plenty of conductive scaffold biomaterials have been exploited to improve bone regeneration under infection, potential tissue toxicity under high concentration and antibiotic-resistance are their main deficiencies. This study indicated that HACC-grafted PLGA/HA composite scaffold prepared using an innovative 3D-printing technique and covalent grafting strategy showed significantly enhanced antibacterial activities, especially against the antibiotic-resistant strains, together with good osteogenic activity and biocompatibility. Therefore, it provides an effective porous composite scaffold to combat the infected bone defect in clinic with decreased risks of bacterial resistance and open a feasible strategy for the modification of scaffold interfaces involved in the bone regeneration and anti-infection.

Immobilizing bacitracin on titanium for prophylaxis of infections and for improving osteoinductivity: An in vivo study

Bacitracin immobilized on the titanium (Ti) surface significantly improves anti-bacterial activity and biocompatibility in vitro. In the current study, we investigated the biologic performance (bactericidal effect and bone-implant integration) of bacitracin-modified Ti in vivo. A rat osteomyelitis model with femoral medullary cavity placement of Ti rods was employed to analyze the prophylactic effect of bacitracin-modified Ti (Ti-BC). Thirty-six female Sprague Dawley (SD) rats were used to establish the Ti implant-associated infection. The Ti and Ti-BC rods were incubated with and without Staphylococcus aureus to mimic the contaminated Ti rod and were implanted into the medullary cavity of the left femur, and sterile Ti rods were used as the blank control. After 3 weeks, the bone pathology was evaluated using X-ray and micro-computed tomography (micro-CT) analysis. For the investigation of the Ti-BC implant osseointegration in vivo, fifteen SD rats were divided into three groups (N=5), namely Ti, Ti-dopamine immobilized (Ti-DOPA), and Ti-BC. Ti rods were implanted into the left femoral cavity and micro-CT and histological evaluation was conducted after 12 weeks. The in vivo study indicated that Ti-immobilized bacitracin owned the prophylaxis potential for the infection associated with the Ti implants and allowed for the osseointegration. Thus, the multiple biofunctionalized Ti implants could be realized via immobilization of bacitracin, making them promising candidates for preventing the Ti implant-associated infections while retaining the osseointegration effects.

Biofunctionalization of titanium with bacitracin immobilization shows potential for anti-bacteria, osteogenesis and reduction of macrophage inflammation

Titanium has been widely used in the orthopedic and dental fields, however, the inert nature of Ti makes it unsuitable for application in promoting bone cell growth，osteogenic differentiation and antibacterial ability. The aims of the current study were to investigate the antimicrobial activity and biofunction of the polypeptide antibiotic bacitracin, and obtain a multi-biofunctional titanium implant by covalently-immobilizing titanium with the bacitracin. The results showed that the bacitracin possessed low minimum inhibitory concentration (MIC) to both Staphylococcus aureus and Methicillin-resistant Staphylococcus aureus (MRSA), with the non-cytotoxicity concentration up to 500μg/mL to human bone marrow mesenchymal stem cells (hBMSCs), furthermore, the bacitracin could improve the osteogenic differentiation of hBMSCs. The results of Scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) indicated that bacitracin had been covalently immobilized on the surface of titanium. Immobilized bacitracin could improve the hydrophilic of immobilized titanium. The results of antimicrobial assay demonstrated that the covalently-immobilized bacitracin also had excellent antimicrobial property, and the bacitracin immobilized titanium could inhibit bacterial adhesion and colonization. The results of cell biology experiments proved that the bacitracin immobilized titanium could improve hBMSCs' adhesion, proliferation and osteogenic differentiation. We also found that the macrophages were difficult to spread or activate on the surface of bacitracin immobilized titanium, and the secretion of inflammatory factors had been inhibited. In conclusion, the novel bacitracin immobilized titanium has multi-biofunctions including outstanding antibacterial properties, excellent cell biology performance, and restraining inflammation, which has exciting application prospect.

Covalent immobilization of KR-12 peptide onto a titanium surface for decreasing infection and promoting osteogenic differentiation

Covalent immobilization of KR-12 peptide onto titanium surface for anti-bacteria and promoting osteogenic differentiation.

Quaternised chitosan coating on titanium provides a self-protective surface that prevents bacterial colonisation and implant-associated infections

The Ti rod-treated group showed radiographic signs of osseous destruction, osteolytic lesions and consecutive deformity after 14 days, while the HTi rod-treated group were free of radiographic signs of infection.

Immobilization of hyaluronic acid on plasma-sprayed porous titanium coatings for improving biological properties

In the present study, hyaluronic acid (HyA) was covalently immobilized onto titanium coatings to improve their biological properties. Diffuse reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were employed to characterize the HyA-modified titanium coating. HyA-modified titanium coatings possess better cell-material interaction, and human mesenchymal stem cells present good adhesive morphologies on the surface of TC-AAH. The results of subsequent cellular evaluation showed that the immobilization of HyA on titanium coatings could improve hMSC attachment, proliferation, and differentiation. In vivo evaluation of implants in rabbit femur condyle defect model showed improvements of early osseointegration and bone-to-implant contact of TC-AAH. In conclusion, immobilization of HyA could improve biological properties of titanium coatings.

Improved hMSC functions on titanium coatings by type I collagen immobilization

In this study, type I collagen was fixed onto plasma-sprayed porous titanium coatings by either adsorptive immobilization or covalent immobilization. Surface characterization by scanning electron microscopy (SEM), diffuse reflectance Fourier transform infrared spectroscopy (DR-FTIR) and X-ray photoelectron spectroscopy (XPS) confirmed the biochemical modification of the titanium coatings. The immobilizing effects of type I collagen, including variations in the amount and stability of collagen, were investigated using Sirius red staining. A greater amount of collagen was found on the covalently immobilized titanium coating, and higher stability was achieved relative to the absorptive immobilization surface. Human mesenchymal stem cells (hMSCs) were used to evaluate the cytocompatibility of the modified titanium coatings. Type I collagen immobilized on titanium coating led to enhance cell-material interactions and improved hMSC functions, such as attachment, proliferation, and differentiation. Interestingly, covalently immobilized collagen on titanium coating showed a greater capability to regulate the osteogenic activity of hMSCs than did absorbed collagen, which was explained in terms of the increased amount and higher stability of the covalently linked collagen. The type I collagen covalently immobilized titanium coatings with improved biological function may exhibit better osteointegration in clinical application.

Fabrication and in vitro evaluation of stable collagen/hyaluronic acid biomimetic multilayer on titanium coatings

Layer-by-layer (LBL) self-assembly technique has been proved to be a highly effective method to immobilize the main components of the extracellular matrix such as collagen and hyaluronic acid on titanium-based implants and form a polyelectrolyte multilayer (PEM) film by electrostatic interaction. However, the formed PEM film is unstable in the physiological environment and affects the long-time effectiveness of PEM film. In this study, a modified LBL technology has been developed to fabricate a stable collagen/hyaluronic acid (Col/HA) PEM film on titanium coating (TC) by introducing covalent immobilization. Scanning electron microscopy, diffuse reflectance Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy were used to characterize the PEM film. Results of Sirius red staining demonstrated that the chemical stability of PEM film was greatly improved by covalent cross-linking. Cell culture assays further illustrated that the functions of human mesenchymal stem cells, such as attachment, spreading, proliferation and differentiation, were obviously enhanced by the covalently immobilized Col/HA PEM on TCs compared with the absorbed Col/HA PEM. The improved stability and biological properties of the Col/HA PEM covalently immobilized TC may be beneficial to the early osseointegration of the implants.

Molecular characterization and association analysis of FBXO40 with partial hematological indexes in pig

F-box proteins are quite significant ubiquitin-proteasome pathway regulators in eukaryotic cells. FBXO40, a member of this large family, alters its expression pattern in muscle atrophy. Here we isolated most of the verified porcine FBXO40 coding sequence (CDS) (2258 bp) and assigned it to the porcine chromosome 13q4.1-4.6 by using the INRA-Minnesota porcine radiation hybrid panel, and we also explored the tissue expression distributions, which is relatively high in longissimus dorsi muscle, heart, low in kidney, small intestine, brain, hypophysis, lymphonode, thymus, spleen, large intestine, ovary, stomach, and undetectable in testis, liver, uterus and thyroid gland. Inferring phylogenetic tree was constructed to study the evolutionary implications. Moreover, a HindII (HincII)-RFLP (A/C) polymorphism in 3'-untranslated region (3'-UTR) of porcine FBXO40 gene was demonstrated by sequencing and PCR-restriction fragment length polymorphism (PCR-RFLP) analysis. Statistical analysis result of this polymorphism showed that the allele A was predominant in all detected indigenous breeds, but C in western introduced commercial breeds. The SNP was further analyzed in our experimental pig population including Tongcheng, Landrace, Large White, and crossbreds of Large White × (Landrace × Tongcheng) and Landrace × (Large White × Tongcheng). The association analysis results indicated that the A/C base substitution was associate with some hematological indexes, the hemoglobin concentration (P < 0.0001), mean corpuscular volume hemoglobin concentration (P = 0.0002) and mean corpuscular volume (P = 0.0138).

The chromosomal localization, expression pattern and polymorphism analysis of porcine FSCN1 gene differently expressed from LongSAGE library

Fascin homologue 1 (FSCN1) has established roles in cell adhesion, motility, and cell-cell interactions. Our LongSAGE analysis suggested that FSCN1 was potentially differentially expressed in prenatal pig skeletal muscle. We have cloned the genomic DNA and mRNA sequence of FSCN1 gene and mapped it to SSC3p16-p17. The FSCN1 gene was differently expressed during prenatal skeletal muscle development and exhibited different expression pattern between Tongcheng and Landrace pigs. In Tongcheng pigs, FSCN1 expression was similar at 33 and 65 days post conception (dpc), and then sharply increased to a peak at 90 dpc. In Landrace pigs, however, expression increased between 33 and 65 dpc, peaked at 65 dpc, and was down-regulated thereafter. Significantly different expression levels between Tongcheng and Landrace were observed at 65 and 90 dpc. In postnatal pigs, it was strongly expressed only in the brain, but weakly in skeletal muscle and other tissues. We initially identified 32 SNPs through genomic DNA of FSCN1 gene. Association analysis suggested that the 6840(C/T) mutation was significantly associated with the age at market weight (AGE) (p = 0.0004), average day gain from birth to market (ADG1) (p = 0.0002), and average day gain at testing period (ADG2) (p < 0.0001). Our study suggested that FSCN1 gene plays an in prenatal skeletal muscle development and was a candidate gene for meat production trait.

A high mechanical strength hydrogel from polyacrylamide/polyacrylamide with interpenetrating network structure by two-steps synthesis method

A simple two-steps polymerization method was used to prepare a polyacrylamide hydrogel with a full interpenetrating network structure based on the sorption and porous properties of polyacrylamide superabsorbent. In conditions of 10 g acrylamide monomer, 0.04 g crosslinker for the first polymerization and the second polymerization, respectively, and the swelling ratio of 9, the hydrogel possessed a tensile strength of 1.22 MPa and elongation at break of 900 %.

Conducting film from graphite oxide nanoplatelets and poly(acrylic acid) by layer-by-layer self-assembly

A [poly(acrylic acid)/graphite oxide]n [(PAA/GO)(n)] film with a conductivity of 60 S.cm(-1) was grown layer-by-layer (LbL) using Langmuir-Blodgett self-assembly techniques. GO nanoplatelets were prepared from natural graphite by oxidizing, ball milling, exfoliating, and modifying with cationic surfactant cetyltrimethylammonium bromide (CTAB). The X-ray diffraction pattern reveals that PAA and GO stack orderly LbL and repeatedly in the (PAA/GO)(n) films, and about three carbon molecular layers are superposed on each GO sheet. Fourier transform infrared spectra offer evidence for the interaction between the carboxylic groups on PAA and the CTAB on the surface of the GO nanoplatelets. Electrochemistry measurements show that the conductivity of the (PAA/GO)(n) film depends on the carbon-carbon interlayer height of the GO sheet, and the (PAA/GO)(n) film has a typical positive temperature coefficient effect above the PAA melting temperature. The atomic force microscopy images reveal that CTAB molecules stack in a well-ordered head-to-head structure on both surfaces of the GO nanoplatelets and the GO nanoplatelets are embeded between PAA layers.

Role of peripheral hyperpolarization-activated cyclic nucleotide-modulated channel pacemaker channels in acute and chronic pain models in the rat

Hyperpolarization-activated, cyclic nucleotide-modulated (HCN) channels contribute to rhythmic spontaneous activity in the heart and CNS. Ectopic spontaneous neuronal activity has been implicated in the development and maintenance of acute and chronic hyperalgesia, allodynia and spontaneous pain. Previously, we documented that systemic administration of ZD7288, a specific blocker of pacemaker current (I(h)), decreased ectopic activity in dorsal root ganglion (DRG) and reversed tactile allodynia in spinal nerve ligated (SNL) rats [Chaplan SR, Guo HQ, Lee DH, Luo L, Liu C, Kuei C, Velumian AA, Butler MP, Brown SM, Dubin AE (2003) Neuronal hyperpolarization-activated pacemaker channels drive neuropathic pain. J Neurosci 23:1169-1178]. Spontaneous pain is the chief clinical manifestation of peripheral nerve injury; however, a role for I(h) in spontaneous pain has not been described. Here, in further rat studies, we report that systemic administration of ZD7288 reversed spontaneous pain induced by mild thermal injury (MTI) and tactile allodynia induced by SNL and MTI. In contrast, ZD7288 did not reduce thermal hyperalgesia. An important locus of action appears to be in the skin since intraplantar (local) administration of ZD7288 completely suppressed tactile allodynia arising from MTI and SNL and reduced spontaneous pain due to MTI. Immunohistochemical staining of plantar skin sections detected HCN1-HCN4 expression in mechanosensory structures (e.g., Meissner's corpuscles and Merkel cells). Collectively, these data suggest that expression and modulation of I(h) in the peripheral nervous system, including specialized sensory structures, may play a significant role in sensory processing and contribute to spontaneous pain and tactile allodynia.

Delayed platelet dysfunction in prolonged induced canine hypothermia

Mild to moderate hypothermia (33-32 degrees C) is recognized as beneficial for brain protection after brain trauma. However, there are few experimental reports on hemostatic changes during prolonged hypothermia. We compared hemostatic changes during 72 h of mild to moderate hypothermia with data in normothermic dogs.

METHOD

Mongolian dogs in a hypothermic group (N=7, 33 degrees C core temperature) and normothermic group (N=6, 37.5 degrees C core temperature) were anesthetized and instrumented to control temperatures and record hemodynamic changes continuously. Hypothermia or normothermia was maintained for 72 h. Platelet count, platelet aggregation, and thromboelastograms (TEG) were measured in each group.

RESULTS

Heart rate, blood pressure, pulmonary pressure and blood gas were not significantly different between the two groups. Platelet counts, compared to baseline values, were significantly decreased in both groups (P<0.01). Platelet aggregation was significantly decreased in the hypothermic group after 24 h (P<0.04).

CONCLUSION

Long-term hypothermia induced platelet dysfunction, leading to decreased platelet aggregation and prolonged coagulation time (R and K times of TEG).

Experimental evaluation of the V-point heparin-bonding system applied to a dense-membrane artificial lung during 24-hour extracorporeal circulation in beagles

Heparin was covalently bonded to a hollow-fiber dense-membrane artificial lung and circuit using a silane coupling agent and polyethyleneimine as a spacer. This study investigated whether the novel artificial lung could sustain prolonged extracorporeal lung assist (ECLA) by venoarterial bypass in beagles using minimal anticoagulants. We maintained ECLA for 24 h in 3 groups of minimal systemic heparinization, heparinization with the new anticoagulant nafamostat mesilate, and without any systemic anticoagulant. The results were assessed from the functional performance of the artificial lung and by macroscopic and microscopic examination after the experiments. Artificial lung function, hemodynamics, hemogram, and platelet aggregation activity were well maintained in all groups. There was no plasma leakage from the artificial lung. Although several clots were observed in stagnant areas of the artificial lungs and circuits, there was no clot formation inside the artificial lung in any group. This highly biocompatible, heparin-bonded dense-membrane artificial lung performed well and safely during prolonged ECLA with blood clotting times less than 120 s.

[Production of transgenic lamb integrated with modified human anti-trypsin gene]

This experiment is to produce the human mAAT(modified anti-trypsin) which cures the emphysema specifically through mammalian galactophore of transgenic goat. 56 goats were selected as donor for superovulation by FSF + LH microinjection in this experiment. The pronucleic embryos were injected with human mAAT gene after fertilization in vivo, and transferred to the donors or receptors directly. The superovulation was better in March and May than in December with the number of ovulation of 19.50, 21.70 and 16.06, and number of fertilized embryos of 4.31, 6.48 and 3.57 per-animal respectively. The pregnant rates were 18.18% and 25% respectively after transferred to donors and receptors with natural estrus. The donors also can be used as the embryo receptor with no remarkable decrease of pregnant rate. 29 lamb were labored. 4 positive transgenic lamb were checked by PCR, PCR-Southern and Southern analysis. The integrated efficiency of foreign DNA was 13.79% with microinjection of high copy number of foreign DNA fragment.

Long-term mild hypothermia with extracorporeal lung and heart assist improves survival from prolonged cardiac arrest in dogs

BACKGROUND AND PURPOSE

although normothermic extracorporeal lung and heart assist (ECLHA) improves cardiac outcomes, patients can not benefit from hypothermia-mediated brain protection. The present study evaluated the effects of long-term ECLHA with mild to moderate hypothermia (33 degrees C) in a canine model of prolonged cardiac arrest.

METHODS

15 dogs were assigned to either the hypothermic (seven dogs, 33 degrees C) or normothermic group (eight dogs, 37.5 degrees C). All dogs were induced to normothermic ventricular fibrillation (VF) for 15 min, followed by 24 h of ECLHA and 72 h of intensive care. The hypothermia group maintained core (pulmonary artery) temperature at 33 degrees C for 20 h starting from resuscitation, then were rewarmed by 28 h. Outcome evaluations included: (1) mortality; (2) catecholamine dose; (3) time to extubation; (4) necrotic myocardial mass (g); and (5) neurological deficits score (NDS).

RESULTS

in the normothermic group five dogs died of cardiogenic shock and one dog succumbed to poor oxygenation. The two surviving dogs remained comatose (NDS 60.5 +/- 4.9%) with necrotic myocardial mass of 14.5 +/- 3.5 g. In the hypothermic group, one dog died from pulmonary dysfunction, the other six dogs survived. The surviving dogs showed brain damage (29.8 +/- 2.5%), but there was evidence of some brain-protective effect. The mass of necrotic myocardium was 4.2 +/- 1.3 g in the hypothermic group or 3.4 times smaller than in the normothermic group. The survival rate was significantly higher in the hypothermic than in the normothermic group (P < 0.05). The catecholamine requirement was also lower in the hypothermic than in the normothermic dogs (P < 0.05).

CONCLUSIONS

Long-term mild to moderate hypothermia with ECLHA induced immediately after cardiac arrest improved survival as well as cerebral and cardiac outcomes.

Heparin bonding of the extracorporeal circuit reduces thrombosis during prolonged lung assist in goats

This study investigated whether an artificial membrane lung of nonmicroporous polyolefin hollow fibers bonded with heparin could prolong venoarterial extracorporeal lung assist (ECLA) with low dose systemic heparin in goats. We compared heparin bonded circuits (Carmeda Bioactive Surface, "HB" group, n = 5) with non heparin bonded circuits ("NHB" group, n = 5) in venoarterial ECLA (V-A ECLA) for 7 days. Activated coagulation time (ACT) was maintained at approximately 130 sec by systemic infusion of small doses of heparin in the HB group, and at 200-230 sec in the NHB group. Thrombus formation was assessed by visual examination of the circuit, and possible cerebral embolization of thrombi was observed from behavioral abnormalities of the animals. The mean heparin dose given during ECLA was 20.4 +/- 3.6 U/kg per hr in HB, and 50.9 +/- 14.2 U/kg per hr in NHB, significantly less in HB than NHB (p < 0.01). Blood gas changes across the oxygenator, bypass flow rate, platelet aggregation activity, platelet counts, fibrin monomer (FM) test, and antithrombin-III (AT-III) activity did not differ between the two groups. In HB, thrombi were fewer and no abnormal neurologic symptoms were observed during ECLA. Numerous thrombi were observed in all oxygenators with NHB. One NHB goat developed convulsions and cerebral hemorrhage on the 6th day of ECLA. Nonmicroporous polyolefin hollow fibers can be bonded with heparin. An artificial membrane lung constructed of these fibers showed good anticoagulation by decreased thrombus formation with a small dose of infused heparin.

Total and prolonged filling of the lungs with Ringer's solution under extracorporeal lung assist (ECLA) in dogs

BACKGROUND

Massive alveolar lavage has been used clinically to remove materials accumulated in the alveoli. Recently, filling the lungs with oxygenated perfluorochemical (total liquid ventilation) has been investigated. However, effects of complete and prolonged filling of bilateral lungs with aqueous fluid, such as saline or Ringer's solution, has not been evaluated, although it is possible to sustain gas exchange without the natural lung by using extracorporeal circulation and an artificial lung (extracorporeal lung assist: ECLA). It is also not known whether the lung can recover gas exchange ability after prolonged fluid filling.

METHODS

Normal mongrel dogs were endotracheally intubated under general anesthesia and mechanically ventilated. After initiation of venoarterial ECLA, warmed lactated Ringer's solution was instilled into the lungs through the endotracheal tube, and the lungs were completely filled at a hydrostatic pressure of 15 cmH2O (fluid-filled group: group F). After the lungs were filled for 4 h, the fluid was drained and ventilation was re-instituted. ECLA, then mechanical ventilation was gradually weaned within 24 h after fluid drainage. In control group (group C), dogs were kept apneic for 4 h with their lungs inflated at an airway pressure of 15 cmH2O with air.

RESULTS

Transient hypoxemia occurred during fluid filling but every dog could be weaned from ECLA and mechanical ventilation to spontaneous respiration. The average rate of fluid absorption from the lung during fluid filling was 4.2+/-1.8 ml kg(-1) h(-1). After fluid drainage and restart of mechanical ventilation, bilateral lungs were expanded and well aerated. Total static respiratory system compliance (static compliance) remained unchanged even after fluid filling, and the weight of the lung water did not increase significantly compared to that in group C. Total urine volume was significantly increased in group E Histologically, alveolar structures were preserved and no interstitial edema or bleeding was seen in either group.

CONCLUSION

Complete filling of the bilateral lungs for 4 h with lactated Ringer's solution under ECLA causes no deterioration in gas exchange or static compliance in normal dogs, although transient hypoxemia occurs during fluid filling.

Jugular vein temperature reflects brain temperature during hypothermia

PURPOSE

The neuroprotective properties of mild to moderate hypothermia are well recognized but may not be employed correctly because brain temperature cannot usually be measured directly. This study investigated the jugular vein as a more accessible site that accurately reflects the actual brain temperature during mild, induced hypothermia.

METHODS

We selected ten mongrel dogs (mean weight 12 +/- 2 kg) and measured temperatures of the brain, jugular vein, cisterna magna, pulmonary artery and rectum during hypothermia, including cooling and rewarming. The brain temperature needle probe was inserted 2.0 cm into the parenchyma. A temperature probe was placed in the cisterna magna with an epidural needle. Swan-Ganz thermistor probes measured the jugular venous and pulmonary artery blood temperatures.

RESULT

The brain temperature decreased from 37.5 +/- 0.3 to 33.0 +/- 0.3 degrees C over an average 150 +/- 45 min cooling period. Stable cool was maintained for 245 +/- 32 min, followed by 165 +/- 50 min for rewarming from 33.5 +/- 0.3 to 37.5 +/- 0.3 degrees C. Jugular, cisterna magna and pulmonary arterial blood (PAB), but not rectal temperature, were close to brain temperature during stable cool. The mean jugular and cisterna magna temperatures were near the brain temperature at 0.1 degrees C higher and 0.1 degrees C lower, respectively. No significant effects of hypothermia were noted on hemodynamics in any phase.

CONCLUSION

Jugular vein temperature, along with cisterna magna and pulmonary artery blood and rectal temperature, reflected brain temperature during hypothermia. The jugular vein and cisterna magna sites more sensitively reflected brain temperature than other sites.

Sero- and molecular typing of Duffy blood group in Southeast Asians and Oceanians

Duffy blood group was studied among malaria-endemic Thai and Indonesian populations: Hmong (n = 103), Akha (n = 218), Lisu (n = 44), Bugis (n = 95), Toraja (n = 77), Dani (n = 44), Mee (n = 80) and Irianese (n = 81). Phenotypes were studied by the ordinal indirect Coombs' test and genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) test. DNA analysis was used to type the Duffy blood group system. Deduced allele frequencies of Fya (0.958-1.0) based on the phenotypes were similar to those in other populations in Southeast Asia and Oceania. The study revealed the presence of Fya-antigens showing weak reactivity to antisera as well as a discrepancy between the genotype shown by the PCR-RFLP study and that predicted by the phenotype. The PCR-RFLP study also suggested the presence of an alternative genetic basis for the Fy(a- b-) phenotype, which differs from the African type.

Molecular cloning of the Lon protease gene from Thermus thermophilus HB8 and characterization of its gene product

The gene encoding Lon protease was isolated from an extreme thermophile, Thermus thermophilus HB8. Sequence analysis demonstrated that the T. thermophilus Lon protease gene (TT-lon) contains a protein-coding sequence consisting of 2385 bp which is approximately 56% homologous to the Escherichia coli counterpart. As expected, the G/C content of TT-lon was 68%, which is significantly higher than that of the E. coli lon gene (52% G/C). The amino acid sequence of T. thermophilus Lon protease (TT-Lon) predicted from the nucleotide sequence contained several unique sequences conserved in other Lon proteases: (a) a cysteine residue at the position just before the putative ATP-binding domain; (b) motif A and B sequences required for composition of the ATP-binding domain; and (c) a serine residue at the proteolytic active site. Expression of TT-lon under the control of the T7 promoter in E. coli produced an 89-kDa protein with a yield of approximately 5 mg.L-1. Recombinant TT-Lon (rTT-Lon) was purified to homogeneity by sequential column chromatography. The peptidase activity of rTT-Lon was activated by ATP and alpha-casein. rTT-Lon cleaved succinyl-phenylalanyl-leucyl-phenylalanyl-methoxynaphthylamide much more efficiently than succinyl-alanyl-alanyl-phenylalanyl-methoxynaphthylamide, whereas both peptides were cleaved with comparable efficiencies by E. coli Lon. These results suggest that there is a difference between TT-Lon and E. coli Lon in substrate specificity. rTT-Lon most effectively cleaved substrate peptides at 70 degrees C, which was significantly higher than the optimal temperature (37 degrees C) for E. coli Lon. Together, these results indicate that the TT-lon gene isolated from T. thermophilus HB8 actually encodes an ATP-dependent thermostable protease Lon.