Identification and characterization of an unexpected isomerization motif in CDRH2 that affects antibody activity.

Aspartic acid (Asp) isomerization is a spontaneous non-enzymatic post-translation modification causing a change in the structure of the protein backbone, which is commonly observed in therapeutic antibodies during manufacturing and storage. The Asps in Asp-Gly (DG), Asp-Ser (DS), and Asp-Thr (DT) motifs in the structurally flexible regions, such as complementarity-determining regions (CDRs) in antibodies, are often found to have high rate of isomerization, and they are considered "hot spots" in antibodies. In contrast, the Asp-His (DH) motif is usually considered a silent spot with low isomerization propensity. However, in monoclonal antibody mAb-a, the isomerization rate of an Asp residue, Asp55, in the aspartic acid-histidine-lysine (DHK) motif present in CDRH2 was found to be unexpectedly high. By determining the conformation of DHK motif in the crystal structure of mAb-a, we found that the Cgamma of the Asp side chain carbonyl group and the back bone amide nitrogen of successor His were in proximal contact, which facilitates the formation of succinimide intermediate, and the +2 Lys played an important role in stabilizing such conformation. The contributing roles of the His and Lys residues in DHK motif were also verified using a series of synthetic peptides. This study identified a novel Asp isomerization hot spot, DHK, and the structural-based molecular mechanism was revealed. When 20% Asp55 isomerization in this DHK motif occurred in mAb-a, antigen binding activity reduced to 54%, but the pharmacokinetics in rat was not affected significantly. Although Asp isomerization of DHK motif in CDR does not appear to have a negative impact on PK, DHK motifs in the CDRs of antibody therapeutics should be removed, considering the high propensity of isomerization and impact on antibody activity and stability.

Enhanced Crude Oil Sorption by Modified Plant Materials in Oilfield Wastewater Treatment.

The treatment of oilfield wastewater with high crude oil content and complex composition is a problem requiring considerable attention. In order to effectively remove crude oil contained in wastewater, in this work, rice straw, as an oil-absorbing material, was modified and used as a sorbent for crude oil. Rice straw was modified with alkali and cetyltrimethylammonium chloride (CTAC) by simple substitution reaction. The adsorption capacity of modified rice straw for oil was evaluated. The results illustrate that the adsorption rate of rice straw for crude oil was increased from 0.83 to 8.49 g/g, with the optimal conditions of 18% NaOH reacted for 90 min at 50 °C and 2% CTAC reacted for 60 min at 20 °C. The proposed modification method could be used for different materials to enhance the adsorption rate. The results of the contact angle test show that the modified straw changed from hydrophilic to hydrophobic, which may be the main reason for the improvement in the oil absorption rate. Finally, the surface structure of rice straw was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and N2 adsorption-desorption isotherms, which further confirmed the hydrophobicity of the modified rice straw.

Tumor targeting and microenvironment-responsive multifunctional fusion protein for pro-apoptotic peptide delivery.

The great therapeutic potential of peptides has not yet been achieved, mainly due to their remarkably short in vivo half-life. Although conjugation to macromolecules has been an effective way of improving protein in vivo half-life, the steric hindrance of macromolecules usually reduces the in vivo efficacy of peptides. Here we report a complex delivery system made from PsTag polypeptide, polyglutamic acid chain, matrix metalloproteinase 2 (MMP2)-degradable domain and cationic cell penetrating peptide for anticancer peptide delivery. Clear evidence was shown in vitro and in vivo to demonstrate that this multifunctional protein fusing a pro-apoptotic KLAKLAKKLAKLAK (KLA), named PAK, can increase circulation time in blood, enhance accumulation at tumor sites, eliminate the PsTag domain and the polyanionic sequence when triggered by tumor overexpressing MMP2, and then expose the cell penetrating peptide to realize the potent cellular uptake of KLA. Treatment of tumor-bearing mice with PAK could markedly induce tumor cells apoptosis and inhibit tumor growth, with no significant adverse effects. These results suggest our fusion protein can be a potential delivery system for peptide delivery in cancer treatments.

Microenvironment-Responsive Delivery of the Cas9 RNA-Guided Endonuclease for Efficient Genome Editing.

Successful and efficient delivery of Cas9 protein and gRNA into cells is critical for genome editing and its therapeutic application. In this study, we developed an improved supercharged polypeptide (SCP) mediated delivery system based on dithiocyclopeptide linker to realize the effective genome editing in tumor cells. The fusion protein Cas9-linker-SCP (Cas9-LS) forms positively charged complexes with gRNA in vitro to provide possibilities for gRNA delivery into cells. Under the microenvironment of tumor cells, the dithiocyclopeptide linker, containing matrix metalloproteinase 2 (MMP-2) sensitive sequence and an intramolecular disulfide bond, can be completely disconnected to promote the release of Cas9 protein with the nuclear localization sequence (NLS) in the cytoplasm and transfer to the cell nucleus for highly efficient genome editing, resulting in an obvious increase of indel efficiency in comparison to fusion protein without dithiocyclopeptide linker (Cas9-SCP). Furthermore, Cas9-LS shows no significant cytotoxicity and minimal hemolytic activity. We envision that the microenvironment-responsive Cas9 protein delivery system can facilitate more efficient genome editing in tumor cells.

Potent Protein Delivery into Mammalian Cells via a Supercharged Polypeptide.

The efficient delivery of proteins into cells is needed to fully realize the potential of protein-based therapeutics. Current protein delivery strategies generally suffer from poor endosomal escape and low tolerance for serum. Here, the genetic fusion of a supercharged polypeptide, called SCP, to a protein provides a generic method for intracellular protein delivery. It allows efficient protein endocytosis and endosomal escape and is capable of potently delivering various proteins with a range of charges, sizes, and bioactivities into the nucleus of living cells. SCP is discovered to bind directly to the nuclear import protein importin ß1 and gains access to the nucleus. Furthermore, SCP shows minimal hemolytic activity and stability in serum and lacks toxicity and immunogenicity in vivo. Effective gene editing can be achieved by SCP-mediated delivery of Cas9 protein and guide RNA. This study may provide an efficient and useful tool for the design and development of cell-nuclear-targeted drug delivery.

Annexin A4-nuclear factor-κB feedback circuit regulates cell malignant behavior and tumor growth in gallbladder cancer.

Gallbladder cancer (GBC) is the most common malignant tumor of the biliary system. However, the mechanisms underlying its tumor initiation, progression, and metastasis are not yet fully understood. The annexin A4 (ANXA4) gene is highly expressed in GBC tissues and may play an important role in the initiation and progression of this disease. In this study, we examined the up-regulation of ANXA4 in human GBC tissues and cell lines. Elevated ANXA4 correlated well with invasion depth in GBC patients and predicted a poor prognosis. In vitro, GBC-SD and NOZ cells with ANXA4 knockdown demonstrated increased apoptosis and inhibited cell growth, migration, and invasion. Interactions between ANXA4 and nuclear factor-κB (NF-κB) p65 proteins were detected. In vivo, ANXA4 knockdown inhibited tumor growth of GBC cells in nude mice and down-regulated the expression of downstream factors in the NF-κB signaling pathway. Taken together, these data indicate that up-regulation of ANXA4 leads to activation of the NF-κB pathway and its target genes in a feedback regulatory mechanism via the p65 subunit, resulting in tumor growth in GBC.

Hepatocyte nuclear factor 4α suppresses the aggravation of colon carcinoma.

Hepatocyte nuclear factor 4-α (HNF4α), a nuclear receptor, is expressed at lower levels in colon carcinoma tissues than in adjacent normal tissues. However, the relation between HNF4α and colon cancer progression and the underlying molecular mechanisms remain unclear. Here, we investigated the role of HNF4α in the progression of colon carcinoma. We showed that HNF4α mRNA and protein were downregulated in colon carcinoma specimens. HNF4α expression was related to pT classification (P < 0.001), lymph node metastasis (P = 0.002), distant metastasis (P < 0.001) and clinical stage (P < 0.001) in colon carcinoma patients. Patients with low or negative HNF4α expression had worse 3-year progression-free survival (PFS, P = 0.006) and overall survival (OS, P = 0.005) than patients with high HNF4α expression. Low HNF4α expression was an independent prognostic factor for 3-year PFS (hazard ratio 2.94; 95% confidence interval 1.047-8.250; P = 0.041). Ectopic expression of HNF4α inhibited colon carcinoma cell (HT29, LoVo, and SW480) proliferation, migration, and invasion, induced G2/M phase arrest and promoted apoptosis. Ectopic expression of HNF4α upregulated E-cadherin and downregulated vimentin in vitro, and suppressed SW480 xenograft tumor growth and liver metastasis in vivo. Furthermore, HNF4α overexpression downregulated the expression of snail, slug and twist. HNF4α inhibited EMT through its effect on the Wnt/ß-catenin signaling pathway, and HNF4α downregulation may be mediated by promoter methylation in cancer tissues. Our results suggest that downregulation of HNF4α plays a critical role in the aggravation of colon carcinoma possibly by promoting EMT via the Wnt/ß-catenin signaling pathway and by affecting apoptosis and cell cycle progression.

Allogeneic blood transfusion and the prognosis of gastric cancer patients: systematic review and meta-analysis.

BACKGROUND: Perioperative allogeneic blood transfusion (ABT) may be a deleterious predictor on the prognosis of gastric cancer (GC) for subjects who had undergone curative surgeries. In this article we proposed to figure out the effect of ABT with a systematic review and meta-analysis. METHODS: Relevant articles were identified by searching Pubmed and Embase to March 2014. A random-effects model or fixed-effects model was used to calculate pooled odds ratios (ORs). Sensitivity analysis, meta-regression, stratified analysis, dose-response meta-analysis were conducted, and publication bias tested. RESULTS: Eighteen studies (9120 GC patients) were included, of which 36.3% received transfusions. ABT was associated with increased all-cause mortality (OR, 2.17; 95% confidence interval [CI], 1.72-2.74; p<0.001; I2=75%). Sensitivity analysis showed significant changes in ORs while meta-regression had little influence on ORs. Galbraith plot revealed the OR reduced to 2.10 (95% CI, 1.86-2.37; p<0.001) with tau2 reduced to 0.00 and I2 reduced to 0%. RESULTS of stratified analysis were robust and consistent. Dose-response meta-analysis revealed that all-cause mortality was significantly lower in patients transfused with ≤800 mL of blood than those transfused with >800 mL (OR, 0.58; 95% CI, 0.37-0.92; p=0.02; I2=54%). ABT was also associated with increased cancer-related mortality (OR, 2.57, p=0.011) and recurrence (OR, 1.52, p=0.017). CONCLUSIONS: In GC patients undergoing curative surgeries, ABTs are associated with a worse prognosis, including all-cause mortality, cancer-related mortality and recurrence. Patient blood management should be investigated further to minimize use of ABT.

Proteomic identification of tumor biomarkers associated with primary gallbladder cancer.

AIM: To identify potential biomarkers of primary gallbladder cancer (PGC). METHODS: Fresh PGC, cholecystitis and normal gallbladder tissue specimens collected from 10 patients, respectively, were subjected to comparative proteomic analysis. The proteomic patterns of PGC were compared with those of cholecystitis and normal gallbladder tissues using two-dimensional gel electrophoresis (2-DE). The differentially expressed proteins were then identified using a MALDI-TOF mass spectrometer (MS) and database searches. To further validate these proteins, 20 samples of PGC tissues and normal tumor-adjacent tissues were collected for Western blot, quantitative real-time PCR, and immunohistochemical staining assay. RESULTS: Seven differentially expressed protein spots were detected by 2-ED analysis by comparing the average maps of PGC, cholecystitis and normal gallbladder tissues. Six of the seven differentially expressed proteins were identified using MALDI-TOF MS, with three overexpressed and three underexpressed in PGC tissue. Protein levels of annexin A4 (ANXA4) were significantly elevated, and heat shock protein 90-beta (Hsp90ß) and dynein cytoplasmic 1 heavy chain 1 (Dync1h1) were decreased in PGC tissues relative to the normal tumor-adjacent tissues as shown by Western blot analysis. However, levels of actin, aortic smooth muscle and gamma-actin were unchanged. In addition, the mRNA levels of all 5 proteins showed similar changes to those of the protein levels (P < 0.01). Further validation by immunohistochemical analysis showed the upregulated expression of ANXA4 and decreased expression of Hsp90ß and Dync1h1 in the cytoplasm of PGC tissues relative to the normal tumor-adjacent tissues. CONCLUSION: Three proteins are identified as potential biomarkers of PGC using proteomic analysis. The functions of these proteins in the carcinogenesis of PGC remain to be studied.

[Medium and long-term clinical results of using Zweymüller cup to treat protrusio acetabuli].

OBJECTIVE: To discuss long-term clinical results of using Zweymüller cup to treat protrusio acetabuli. METHODS: From May 1998 to September 2006, 31 patients with 39 hips diagnosed protrusio acetabuli were treated with Zweymüller cup in total hip arthroplasties or revisions. There were 12 men and 19 women with average age of 57.6 years (from 30 to 82 years). The reasons causing protrusio acetabuli were as followed: rheumatoid arthritis 3 cases 6 hips, osteoarthritis followed femoral head necrosis 7 cases 12 hips, acetabular wear after hemi-arthroplasty 11 cases 11 hips and acetabular component loosening 10 cases 10 hips. During all operations, Zweymüller cup was used to fix the acetabular part. RESULTS: All cases were followed up 6 months and one year after operations. Two patients with 3 hips were died for lung cancer and acute myocardial infarction respectively. Twenty-four cases with 31 hips got recent follow-up with average 7.4 years (from 5.0 to 11.5 years). The average Harris score improved from 31.0 (from 14 to 61) preoperatively to 84.7 (from 70 to 95) postoperatively. There was one infection in right hip after bilateral hip arthroplasty treating by removal prosthesis and cement spacer insert. But until now this patient still did not get revision for her internal medicine. One rheumatoid arthritis patient with two-stage bilateral hip arthroplasty was found slight internal migration and loosening line of left acetabular component, but the patient had no pain with good hip function. All other cases had good hip functions and were very satisfied with clinical results. CONCLUSION: Using Zweymüller cup to treat protrusion acetabuli can get strong fixations and perfect medium and long-term clinical results for over 7.4 years.

Randomized clinical trial of vessel sealing system (LigaSure) in esophagogastric devascularization and splenectomy in patients with portal hypertension.

BACKGROUND: The LigaSure vessel sealing system (Valleylab, Boulder, CO) has been tested, with excellent results, in different fields of surgery. However, no study has evaluated the efficiency of the LigaSure in open esophagogastric decongestion and splenectomy in a randomized trial to date. METHODS: Patients scheduled to undergo esophagogastric decongestion and splenectomy were assigned to the use of either the LigaSure or a conventional clamp-and-tie technique. Primary outcome measures were operating time and intraoperative blood loss. Secondary outcome measures were postoperative drainage volume, complications such as spleen fever, bleeding, portal vein thrombosis, length of incision, pain, and time to discharge. RESULTS: Sixty patients were randomized to the LigaSure (n = 30) and clamp-and-tie (n = 30) groups. The groups were well matched with respect to liver function, associated illnesses, and grading of esophageal varices. Postoperative outcomes in drainage and major complications did not differ between the groups, while operative time and the volume of blood loss were significantly decreased in the LigaSure group compared with the clamp-and-tie group (P < .001). CONCLUSIONS: The use of the LigaSure is safe and effective in vessel division and homeostasis in the esophagogastric decongestion and splenectomy, with statistically significant decreases in operative time and intraoperative blood loss and without significantly modifying postoperative results.

LTB4 can stimulate human osteoclast differentiation dependent of RANKL.

Our previous study showed that Leukotriene B4 can directly stimulate osteoclast differentiation independent of RANKL. In order to determine whether Leukotriene B4 could indirectly stimulate human osteoclast differentiation through increasing RANKL expression of rheumatoid arthritis fibroblast-like synoviocytes, we utilize the coculture model of rheumatoid arthritis fibroblast-like synoviocytes and monocyte, which were stimulated in the presence of 2.5 ng/ml M-CSF in the control group, 2.5 ng/ml M-CSF+10(-8)M LTB4 in the experimental group a, and 2.5 ng/ml M-CSF+10(-8)M LTB4+100 ng/ml OPG in the experimental group b. After culture for 3 weeks, the number of multinucleated TRAP staining positive osteoclast-like cells stained with TRAP was counted to evaluate the differentiation effect in each group. There was almost no osteoclast-like cell in the control group and the experimental group b. There were many osteoclast-like cells in the experimental group a. These results indicated that Leukotriene B4 is capable of inducing osteoclast differentiation by a RANKL-dependent mechanism.

Prospective clinical trials of thyroidectomy with LigaSure vs conventional vessel ligation: a systematic review and meta-analysis.

OBJECTIVE: To evaluate the hemostatic effects and safety of thyroidectomy performed using the LigaSure vessel-sealing device (Valleylab, Boulder, Colorado) or the conventional vessel ligation. DATA SOURCES: The MEDLINE, EMBASE, Elsevier, SpringerLink, Ovid, and Cochrane Library electronic databases as well as the LigaSure manufacturer's Web site were searched for studies published between 1996 and 2008. No language restrictions were applied. STUDY SELECTION: Prospective, controlled clinical trials, both randomized and nonrandomized, comparing the hemostatic effects and safety of thyroidectomy using LigaSure and conventional vessel ligation were selected. DATA EXTRACTION: Data regarding operative parameters, duration of the operation, amount of intraoperative blood loss, length of hospital stay, and any postoperative complications were entered and analyzed using dedicated software from the Cochrane Collaboration. DATA SYNTHESIS: Four randomized and 5 nonrandomized trials that met selection criteria reported data from 927 patients, of whom 467 (50.4%) underwent LigaSure and 460 (49.6%) underwent conventional thyroidectomy. Operative duration (weighted mean difference [WMD], -11.97 minutes; 95% confidence interval [CI], -16.42 to -7.53 minutes) was significantly reduced with LigaSure thyroidectomy (P < .001). When LigaSure was used, operative time reductions of 20.32 minutes (95% CI, -33.86 to -6.79 minutes) for total thyroidectomy (P = .003) and 21.74 minutes (-38.32 to -5.16 minutes) for subtotal thyroidectomy (P = .01) were also confirmed with subgroup analysis. However, differences in the amount of intraoperative blood loss (WMD, -25.13 mL; 95% CI, -68.45 to 18.18 mL; P = .26), length of hospital stay (WMD, -0.08 days; 95% CI, -0.23 to 0.08 days; P = .31), and postoperative complication rates (odds ratio, 0.91; 95% CI, 0.61-1.04; P = .65) were not statistically significant for LigaSure vs conventional thyroidectomy. CONCLUSIONS: The LigaSure technique may provide a safe, effective, and fast alternative to conventional vessel ligation in thyroidectomy and may result in a significant reduction in operative duration. However, it may not confer any advantage over conventional thyroidectomy in terms of the amount of intraoperative blood loss, length of hospital stay, and postoperative complication rates.

[Effects of primary deep venous valvular incompetence of lower limb in deep vein thrombus after total knee replacement].

OBJECTIVE: To evaluate the effects of primary deep venous valvular incompetence of lower limb (PDVI) to the occurrence of deep vein thrombosis (DVT) after human total knee replacement (TKR). METHODS: One hundred and twenty-six patients who planed to receive TKR were examined by color doppler flow imaging (CDFI). The patients were divided into 2 groups depending on whether they were found backstreaming in femoral vein or not. When the refluxing time > 1 s, the patients were included in PDVI group; When the refluxing time < or = 1 s, the patients were included in without PDVI group. In 7 d after operation all the patients were re-examined by CDFI to find if there was DVT. The results were tested by chi2 statistical analysis. RESULTS: Among the 126 patients, 54 had PDVI, and 72 without PDVI. Fifty patients had DVT, total incidence rate 39.7% (50/126). In PDVI group 33 patients had DVT (61.1%, 33/54); In without PDVI group 17 patients had DVT (23.6%, 17/72), which was lower than PDVI group (chi2 = 21.227, P < 0.05). CONCLUSIONS: PDVI may be a risk for occurrence of DVT after TKR.

[Total knee arthroplasty in Charcot arthritis patients].

OBJECTIVE: To discuss the results of total knee arthroplasty undertaken for Charcot arthritis patients. METHODS: Between September 2000 and January 2007, 4 consecutive patients (2 men and 2 women; 5 TKAs) with Charcot arthritic knees were treated. At the time of surgery, the mean age of the patients was 67.3 years (64 to 72 years). One had bilateral and 2 had unilateral TKA and one had ipsilateral total hip and total knee arthroplasty. The mean knee society score before operation was 33.75 points. RESULTS: The mean follow-up was 65 months (19 to 96 months). The mean knee society score post-operation had improved to 95.25 points in 5 TKAs with no occurrence of infection and loosening. All 4 patients were very satisfactory with the clinical results at the last follow-up. CONCLUSIONS: The midterm follow-up data indicated that total knee arthroplasty to treat Charcot arthritis could get good clinical results. The postoperative results in Charcot arthritis were closed related with the proper prosthesis and surgical technique.

[Overexpression of programmed cell death 5 factor enhances triptolides-induced fibroblast-like synoviocytes apoptosis in rheumatoid arthritis].

OBJECTIVE: To explore the effect of programmed cell death 5(PDCD5) on apoptosis of rheumatoid arthritis fibroblast-like synoviocytes(RA FLS) induced by triptolide. METHODS: Cultured synovial cells in vitro from RA patients were transfected with Ad-PDCD5.At protein level, expression of PDCD5 in RA FLS infected with Ad-PDCD5 was detected by Western blot.RA FLS infected with Ad-PDCD5 were cultured in presence or absence of triptolide and apoptosis of RA FLS was determined by flow cytometry. RESULTS: Infection of RA FLS with increasing concentrations of Ad-PDCD5(50-300 MOI) resulted in a does-dependent increase in the production of PDCD5. Apoptotic cells percentage for noinfection group, Ad-null group and Ad-PDCD5 group were(22.41 +/- 3.87)%, (28.77 +/- 12.97)% and (48.87 +/- 12.69)%, respectively. Alternatively, infection without addition of triptolide stimuli had no effect. The data showed that gene transfection of PDCD5 alone without addition of triptolide was not sufficient to activate RA FLS apoptosis, PDCD5 acted as an enhancer rather than inductor of apoptosis. CONCLUSION: Overexpression of PDCD5 could enhance apoptosis of RA FLS induced by triptolide, PDCD5 may be a potential therapeutic target to RA.

Intraoperative allogeneic red blood cell transfusion in ampullary cancer outcome after curative pancreatoduodenectomy: a clinical study and meta-analysis.

BACKGROUND: Allogeneic blood transfusion (ABT) containing packed red blood cells (RBCs) has a known immunosuppressive effect that may affect cancer metastases and recurrence. This study examined whether intraoperative allogeneic RBC transfusion is an independent risk factor of adverse outcome in patients with ampullary carcinoma after curative pancreatoduodenectomy. METHODS: The clinical data of 67 patients with carcinoma of the ampulla of Vatar underwent pancreatoduodenectomy between 1999 and 2004 were analyzed, and long-term follow-up visits were made for all patients. Kaplan-Meier statistics and Cox proportional hazard methodology were used to perform univariate and multivariate analysis to identify independent risk factors for survival. For the meta-analysis, all English-language studies regarding blood transfusion from carcinoma of the ampulla of Vatar or ampullary carcinoma and prognostic factors or factors for survival from 1995 to 2007 were reviewed, and contingency tables were constructed from which a summary relative risk was calculated. RESULTS: There were 43 patients (64.2%) who received an intraoperative ABT. The amount of intraoperative ABT ranged from 2 to 13 (mean, 4.25) units; there were 18 patients transfused at 2 units, and 25 patients transfused > or =3 units. The follow-up ranged from 2 to 90 (mean, 49) months. Forty-five patients (67.2%) died as a result of tumor progression. For patients transfused > or =3 units, median and cumulative 3-year and 5-year survivals were poorer significantly than that of patients transfused with 2 units and/or nontransfused patients (P < 0.05). After multivariate analysis, except for presence of lymph node metastasis (P = 0.023) and pancreatic invasion (P = 0.024), the intraoperative ABT > or =3 units was found to be an independent poor prognostic factor for those with ampullary cancer after curative pancreatoduodenectomy either (relative risk, 2.082; 95% confidence interval (CI), 1.048-4.135; P = 0.036). Meta-analysis of 346 patients showed the summary relative risk of an adverse outcome after intraoperative ABT in these studies was 2.55 (95% CI, 1.59-4.1). CONCLUSIONS: The amount of intraoperative ABT is one of the important factors that adversely influenced survival in patients with ampullary cancer after curative pancreatoduodenectomy. Healing anemia preoperatively and careful dissection to minimize intraoperative bleeding as much as possible are mandatory for reducing risk of the intraoperative ABT.

[Total knee arthroplasty and perioperative management of hemophilic arthritis].

OBJECTIVE: To evaluate the clinical results and perioperative management of primary total knee arthroplasty (TKA) in hemophilic patients. METHODS: From February 1997 to February 2006, the data of 6 total knee arthroplasty performed in 4 hemophilic patients was reviewed retrospectively. The values of coagulation factor were maintained at suitable level by monitoring the activity of the factors and their inhibitors during perioperative period. The mean follow-up time was 4.4 years, knee society score and the last postoperative radiographs were recorded. RESULTS: After TKA, the hemophilic patients felt pain of knee relieved, the knee function was improved, but the range of motion increased limitedly. At the early post-operative stage, 3 knees in 2 patients with hemarthrosis or muscle bleeding, 1 of the 2 patients complicated with formation of inhibitor of factor VIII and healing problem in 1 knee after TKA, 1 patient with transient paralysis of the common peroneal nerve, 1 patient with venous circulation insufficiency crisis, but no compartment syndrome. In the late stage after TKA, 1 patient with hemarthrosis of both elbows, but no late infection, loosening, displacement and fracture of the prosthesis in the 6 knees. CONCLUSIONS: Total knee arthroplasty could alleviate knee pain and improve joint function in advanced severe hemophilic arthritic patients. It is important to monitor the activity and inhibitors of coagulation factor VIII or IX, which could decrease the early and late postoperative complications.

[Total knee arthroplasty for extension ankylosing deformity].

OBJECTIVE: To discuss the outcomes and complications of total knee arthroplasty (TKA) for extension ankylosing deformity of the knee. METHODS: From January 1996 to June 2006, total knee arthroplasty was performed on 8 patients (9 knees) with extension ankylosing deformity. The preoperative ROM of all patients was 0 degrees . Preoperative knee and function score of KSS were 44 points (from 10 to 68) and 17 points (from -10 to 55) respectively. RESULTS: The complications of all TKAs included patellar tendon avulsion in 1 knee, partial fracture of inferior patella in 1 knee, hematoma in 1, superficial infection in 1. All patients were followed up for an average of 40.4 months (from 7.0 to 120.0). The average postoperative ROM was 89 degrees (from 50 degrees to 120 degrees ). Postoperative knee and function score of KSS were 81 points (from 55 to 93) and 79 points (from 50 to 90) respectively. Extension lag occurred in 2 knees, one was 10 degrees and the other was 25 degrees . One knee had undergone re-revision of changing the thicker tibial spacer for the reason of instability of joint 1 year after revision. CONCLUSIONS: TKA performed in extension ankylosing deformity can get less satisfactory clinical results comparing with fixed flexion deformity. Exposure of the knee joint and separation of the fused bones, providing a mobile joint space plays crucial procedure for the next step of surgery. Preservation of sufficient bone stock of patella, protection of patellar tendon and blood supply of the knee and proper soft tissue balance are the key to TKA for extension ankylosing deformity.