Major replantation of a traction avulsion amputation is undertaken with the goal of not only the reestablishment of circulation, but also functional outcome. This type of amputation is characterized by different levels of soft-tissue divisions involving crushing, traction, and avulsion injuries to various structures. Between 1985 and 1998, 27 cases were referred for secondary reconstruction following amputation of the upper extremity involving both arm and forearm. Replantation was performed by at least 12 qualified plastic surgeons using different approaches and management, resulting in different outcomes. Initial replantation management significantly affects the later reconstruction. For comparing studies and prognostic implications, the authors propose a new classification according to the level of injury to muscles and innervated nerves: type I, amputation at or close to the musculotendinous aponeurosis with muscles remaining essentially intact; type II, amputation within the muscle bellies but with the proximal muscles still innervated; type III, amputation involving the motor nerve or neuromuscular junction, thereby causing total loss of muscle function; and type IV, amputation through the joint; i.e., disarticulation of the elbow or shoulder joint. Some patients required further reconstruction for functional restoration after replantation, but some did not. Through this retrospective study based on the proposed classification system, prospective guidelines for the management of different types of traction avulsion amputation are provided, including the value of replantation, length of bone shortening, primary or delayed muscle or nerve repair, necessity of fasciotomy, timing for using free tissue transfer for wound coverage, and the role of functioning free muscle transplantation for late reconstruction. The final functional outcome can also be anticipated prospectively through this classification system.

Abstract-Although the renin-angiotensin system has been implicated in increasing plasminogen activator inhibitor-1 (PAI-1) expression, the role of the angiotensin type 1 (AT 1 ) receptor is controversial. This report examines the effects of angiotensin peptides, angiotensin-converting enzyme inhibition, and AT 1 antagonism on rat aortic and cardiac PAI-1 gene expression. In vitro, angiotensin (Ang) I, Ang II, and angiotensin Arg 2 -Phe 8 (Ang III) were potent agonists of PAI-1 mRNA expression in rat aortic smooth muscle cells (RASMCs), and stimulation of PAI-1 by these peptides was blocked by the AT 1 antagonist candesartan. Angiotensin Val 3 -Phe 8 (Ang IV) and angiotensin Asp 1 -Pro 7 (Ang [1-7]) did not affect PAI-1 expression in RASMCs. In neonatal rat cardiomyocytes, Ang II increased PAI-1 mRNA expression by 4-fold (PϽ0.01), and this response was completely blocked by AT 1 receptor antagonism. Continuous intrajugular infusion of Ang II into Sprague-Dawley rats for 3 hours increased aortic and cardiac PAI-1 mRNA expression by 17-and 9 fold, respectively, and these Ang II responses were completely blocked by coinfusion with candesartan. Aortic and cardiac PAI-1 expressions were compared in spontaneously hypertensive rats and Wistar-Kyoto rats. PAI-1 expression in the aorta and heart from spontaneously hypertensive rats was 5.8-fold and 2-fold higher, respectively, than in control Wistar-Kyoto rats (PϽ0.05). Candesartan treatment for 1 week reduced aortic and cardiac PAI-1 expression in spontaneously hypertensive rats by 94% and 72%, respectively (PϽ0.05), but did not affect vascular PAI-1 levels in Wistar-Kyoto rats. These results demonstrate a role for the AT 1 receptor in mediating the effects of Ang II on aortic and cardiac PAI-1 gene expression. Key Words: angiotensin II Ⅲ plasminogen activator inhibitor Ⅲ hypertension Ⅲ aorta Ⅲ vascular smooth muscle cells P lasminogen activator inhibitor-1 (PAI-1) is the major inhibitor of tissue and urokinase plasminogen activators and thereby reduces the conversion of plasminogen to plasmin, an extracellular protease that mediates fibrinolysis and activates matrix metalloproteinases. 1-3 An elevated level of PAI-1, which occurs in diabetes, insulin resistance, obesity, and hypertension, has been implicated as a contributing risk factor for cardiovascular disease. 4 -7 Recent studies suggest that the renin-angiotensin system (RAS) may exert an important role in the regulation of circulating and vascular PAI-1 expression and may thereby affect the fibrinolytic balance. Reports from our laboratory and others have demonstrated that angiotensin II (Ang II) is a potent stimulator of PAI-1 mRNA and protein expression in both cultured endothelial and vascular smooth muscle cells. 8 -11 The physiological importance of the RAS in modulating PAI-1 levels is supported by in vivo studies, which have demonstrated that treatment of rats with the angiotensin-converting enzyme (ACE) inhibitor captopril suppresses the induction of PAI-1 expression in the aortic neointima induced by b...

Purpose. To verify the biomechanical importance with respect to the integrity of posteromedial cortex of femoral neck fracture (FNF) and demonstrate whether the modified fixation of cannulated screws (CSs) could increase the biomechanical strength. Methods. A total of 24 left artificial femurs were randomly divided into three groups. The osteotomy was made in the center of the femoral neck at a 20° angle to the shaft axial. The posteromedial cortices of femoral neck were removed in groups B and C. In group A, 8 femurs with intact posteromedial cortex were fixed with three parallel partial thread screws (PTSs), forming a standard triangle. In group B, the femurs were stabilized with the same fixation of CSs like group A. In group C, two inferior PTSs were replaced by two fully thread screws (FTSs). Results. The lower A-P and axial stiffness and load to failure along with higher axial displacement were found in group B compared with group A (p≤0.001 for all). Between groups B and C, the modified fixation of CSs increased A-P and axial stiffness and load to failure and reduced the axial displacement (p≤0.001 for all). Conclusions. We verified that the comminuted posteromedial cortex affected the biomechanical strength adversely and resulted in higher displacement. The modified fixation of CSs characterized by two inferior FTSs could improve the biomechanical performance and buttress the femoral head fragment better.

The screening of differentially expressed genes in plants after pathogen infection can uncover the potential host factors required for the pathogens. In this study, an up-regulated gene was identified and cloned from Nicotiana benthamiana plants after Bamboo mosaic virus (BaMV) inoculation. The up-regulated gene was identified as a member of the Rab small guanosine triphosphatase (GTPase) family, and was designated as NbRABG3f according to its in silico translated product with high identity to that of RABG3f of tomato. Knocking down the expression of NbRABG3f using a virus-induced gene silencing technique in a protoplast inoculation assay significantly reduced the accumulation of BaMV. A transiently expressed NbRABG3f protein in N. benthamiana plants followed by BaMV inoculation enhanced the accumulation of BaMV to approximately 150%. Mutants that had the catalytic site mutation (NbRABG3f/T22N) or had lost their membrane-targeting capability (NbRABG3f/ΔC3) failed to facilitate the accumulation of BaMV in plants. Because the Rab GTPase is responsible for vesicle trafficking between organelles, a mutant with a fixed guanosine diphosphate form was used to identify the donor compartment. The use of green fluorescent protein (GFP) fusion revealed that GFP-NbRABG3f/T22N clearly co-localized with the Golgi marker. In conclusion, BaMV may use NbRABG3f to form vesicles derived from the Golgi membrane for intracellular trafficking to deliver unidentified factors to its replication site; thus, both GTPase activity and membrane-targeting ability are crucial for BaMV accumulation at the cell level.

Rationale: Although a few injectable hydrogels have shown a reliable biosafety and a moderate promise in treating myocardial infarction (MI), the updated hydrogel systems with an on-demand biodegradation and multi-biofunctions to deliver therapeutic drug would achieve more prominent efficacy in the future applications. In this report, a conductive and injectable hydrogel crosslinked by matrix metalloproteinase-sensitive peptides (MMP-SP) was rationally constructed to stabilize hypoxia-inducible factor-1α (HIF-1α) to recover heart functions after MI. Methods: Firstly, tetraaniline (TA) was incorporated into partially oxidized alginate (ALG-CHO) to endow the hydrogels with conductivity. The 1,4-dihydrophenonthrolin-4-one-3-carboxylic acid (DPCA) nanodrug was manufactured with high drug loading capacity and decorated with polymerized dopamine (PDA) to achieve a stable release of the drug. Both ALG-CHO and DPCA@PDA can be cross-linked by thiolated hyaluronic acid (HA-SH) and thiolated MMP-SP to construct a MMP-degradable and conductive hydrogel. After administration in the infarcted heart of rats, echocardiographic assessments, histological evaluation, and RT-PCR were used to evaluate therapeutic effects of hydrogels. Results: The cell viability and the results of subcutaneous implantation verify a good cytocompatibility and biocompatibility of the resulting hydrogels. The hydrogel shows remarkable strength in decreasing the expression of inflammatory factors, maintaining a high level of HIF-1α to promote the vascularization, and promoting the expression of junctional protein connexin 43. Meanwhile, the multifunctional hydrogels greatly reduce the infarcted area (by 33.8%) and improve cardiac functions dramatically with ejection fraction (EF) and fractional shortening (FS) being increased by 31.3% and 19.0%, respectively. Conclusion: The as-prepared hydrogels in this report achieve a favorable therapeutic effect, offering a promising therapeutic strategy for treating heart injury.

Studies of hematopoietic progenitor cell development in vivo, ex vivo, and in factor-dependent cell lines have shown that c-kit promotes proliferation through synergistic effects with at least certain type 1 cytokine receptors, including the erythropoietin (Epo) receptor. Presently, c-kit is shown to efficiently support both mitogenesis and survival in the FDCP1 cell subline, FDC2. In this system, mitogenic synergy with c-kit was observed for ectopically expressed wild-type Epo receptors (wt-ER), an epidermal growth factor (EGF) receptor/Epo receptor chimera, and a highly truncated Epo receptor construct ER-Bx1. Thus, the Epo receptor cytoplasmic box 1 subdomain appears, at least in part, to mediate mitogenic synergy with c-kit. In studies of potential effectors of this response, Jak2 tyrosine phosphorylation was shown to be induced by Epo, but not by stem cell factor (SCF). In addition and in contrast to signaling in Mo7e and BM6 cell lines, in FDC2-ER cells SCF and Epo each were shown to rapidly activate Pim 1 gene expression. Recently, roles also have been suggested for the nuclear trans-factor GATA-1 in regulating progenitor cell proliferation. In FDC2-ER cells, the ectopic expression of GATA-1 had no detectable effect on Epo inhibition of apoptosis. However, GATA-1 expression did result in a selective and marked inhibition in mitogenic responsiveness to SCF and to a decrease in c-kit transcript expression. These studies of SCF and Epo signaling in FDC2–wt-ER cells serve to functionally map the ERB1 region as a c-kit–interactive domain, suggest that Pim1 might contribute to SCF and Epo mitogenic synergy and support the notion that SCF and Epo may act in opposing ways during red cell differentiation.

Epstein-Barr Virus (EBV) Nuclear Antigen 1 (EBNA1)-mediated origin of plasmid replication (oriP) DNA episome maintenance is essential for EBV-mediated tumorigenesis. We have now found that EBNA1 binds to Ribosome Protein L4 (RPL4). RPL4 shRNA knockdown decreased EBNA1 activation of an oriP luciferase reporter, EBNA1 DNA binding in lymphoblastoid cell lines, and EBV genome number per lymphoblastoid cell line. EBV infection increased RPL4 expression and redistributed RPL4 to cell nuclei. RPL4 and Nucleolin (NCL) were a scaffold for an EBNA1-induced oriP complex. The RPL4 N terminus cooperated with NCL-K429 to support EBNA1 and oriPmediated episome binding and maintenance, whereas the NCL C-terminal K380 and K393 induced oriP DNA H3K4me2 modification and promoted EBNA1 activation of oriP-dependent transcription. These observations provide new insights into the mechanisms by which EBV uses NCL and RPL4 to establish persistent B-lymphoblastoid cell infection.pstein-Barr virus (EBV) was recognized as an oncogenic human pathogen after the discovery of its causal associations with B-cell lymphomas (BLs), nasopharyngeal carcinomas, and gastric carcinomas. EBV infects B-lymphocytes and epithelial cells and converts resting B cells into lymphoblastoid cell lines (LCLs). LCL maintenance requires expression of EBV nuclear antigens (EBNAs), latency-associated membrane proteins (LMPs), and noncoding RNAs (1). EBNA1 is the only EBV gene expressed in all types of EBV-infected cells and has a key role in EBV genome maintenance, replication, postmitotic EBV genome segregation, and LCL growth (1, 2). EBNA1-mediated episome maintenance depends on EBNA1 binding to the EBV origin of genome replication (oriP), which has two essential components, a dyad symmetry (DS) element and a family of repeats (FR) (3). Despite a 2.4-Å resolution crystal structure of the EBNA1 DNA binding domain bound to its cognate DNA element (4), mechanistic insights into EBNA1 and oriP-mediated episome maintenance mainly come from genetic studies using EBV recombinants and biochemical studies of EBNA1's association with cell proteins, including CTCF, Bromodomain Protein 4 (BRD4), Nucleosome Assembly Protein 1 (NAP1), the cell Origin Recognition Complex, and the Mini Chromosome Maintenance complex (5-8). Recent studies indicate that EBNA1 may use complex strategies for episome maintenance (9-16).EBNA1-associated ribosome biogenesis factors Nucleophosmin (NPM1) and Nucleolin (NCL) have been implicated in EBNA1 and oriP-dependent functions (17,18). Other viruses also use ribosomal proteins (RPs), such as RPL4, RPS19, and RPL40, to enhance virus protein translation (19-21). Indeed "extraribosomal functions" of RPs were discovered through RPS1 involvement in bacteriophage Qβ-mediated genome replication (22). Moreover, the noncoding EBV RNA, EBER1, causes RPL22 redistribution from the nucleolus to the nucleoplasm and stimulates cell proliferation (23, 24). We have now found complex protein interactions among EBNA1, RPL4, and NCL and have examined the role of these in...

IntroductionPlasminogen activator inhibitor-1 (PAI-1) is the major regulator of both tissue and urokinase plasminogen activators. 1,2 Inhibition of plasminogen activation by PAI-1 reduces the generation of plasmin and thereby impairs fibrinolysis. In addition, PAI-1 has also been suggested to reduce plasmin-mediated activation of matrix metalloproteases 3 and compete with cellular ␣v␤3 integrin matrix interactions, which contribute to cellular migration. 4 Overexpression of PAI-1 in transgenic mice or by adenovirus-mediated gene transfer increases thrombosis, 5,6 and PAI-1 deficiency enhances fibrinolysis and neointimal remodeling. 7,8 Increased levels of PAI-1 have been demonstrated in vascular lesions induced by balloon catheter injury and atherosclerosis. [9][10][11][12] Within these vascular lesions, PAI-1 expression is prominently increased in neointimal smooth muscle cells. 9,13 In previous animal studies using angiotensin-converting enzyme inhibition, angiotensin type 1 receptor antagonism and systemic angiotensin II (Ang II) infusion, our group and others have demonstrated that the Ang II/AT 1 pathway plays an important role in regulating vascular PAI-1 gene expression in vivo. 9,[14][15][16] A host of agonists, including Ang II, transforming growth factor-␤ (TGF-␤), very low density lipoprotein (VLDL), and phorbol ester, require the activity of MAPK/ERK kinase1 and 2 (MEK1,2) to induce PAI-1 mRNA expression. [17][18][19][20] Although the MEK/ERK pathway plays a key role in controlling PAI-1 mRNA levels, the mechanism(s) that mediates the effects of MEK1,2 on PAI-1 transcription have not been identified. Previous reports have demonstrated that the MEK/ERK pathway can affect phosphorylation, nuclear transport, and transactivation of a number of transcription factors, including Elk-1, Sma-and Mad-related protein (SMAD), c-Jun, Sp1, and signal transducer and activator of transcription 3 (STAT3). [21][22][23][24][25] In addition, Ras/MEK/ERK activation can lead to increased expression of intermediate-early response genes, such as c-fos, egr-1, and junB. 26 Although the promoter of the PAI-1 gene contains an array of potential response elements for these transcription factors, 27-29 the contributions of these transcriptional elements to the effects of MEK1,2 on the PAI-1 promoter activity have not yet been elucidated.Given the importance of PAI-1 in vascular physiology and its possible contribution to vasculopathies, further understanding of how the MAP kinase pathways affect PAI-1 expression in vascular smooth muscle cells (VSMCs) is of considerable importance. In this study, we identified and characterized the MEK1,2 response element in the 5Ј flanking region of PAI-1 gene in VSMCs. These studies identified 2 adjacent cis-acting AP-1-like and Sp1-like sequences that functionally cooperate in MEK-induced PAI-1 promoter activation. These results establish a mechanistic link between the MEK/ERK pathway and the activation of the PAI-1 promoter. Materials and methods MaterialsDominant-negative AP-1 (A-Fos), and ...