全膝关节置换术治疗骨关节炎

目的 探讨人工全膝关节置换术治疗骨关节病的临床疗效。方法 对31例人工全膝关节置换术进行临床分析和总结,并应用HSS膝关节评分系统进行分析。结果 手术优良率为93．6％,患者术后在疼痛、功能及关节活动度等方面都有明显改善。结论 全膝关节置换术是治疗骨关节病的有效方法。     

A biomechanical analysis of finger joint forces and stresses developed during common daily activities

The problem of modelling stresses incurred at the finger joints is critical to the design of durable joint replacements in the hand. The goal of this study was to characterise the forces and stresses at the finger and thumb joints occurring during activities such as typing at a keyboard, playing piano, gripping a pen, carrying a weight and opening a jar. The metacarpal and proximal phalanx were modelled using a COMSOL-based finite element analysis. Analysis of these activities indicates that joint forces in excess of 100 N may be common at the metacarpophalangeal joint (MCP) due to carrying objects such as groceries or while opening jars. The model predicted that stresses in excess of 2 MPa, similar to stresses at the hip, occur at the MCP with the properties of cancellous bone playing a significant role in the magnitude and distribution of stress.     

Development of an image-based technique to examine joint congruency at the elbow

Identifying joint contact in articular joints is important for both the biomechanical investigation of joint mechanics and the study of osteoarthritis. The purpose of this study is to develop a proximity mapping technique to non-invasively determine joint congruency, as a surrogate of joint contact. To illustrate the capabilities of this algorithm, a cadaveric upper extremity was positioned at varying degrees of elbow flexion. This technique was validated using a gold standard experimental casting technique. The pattern of the cast showed an excellent agreement with the generated proximity map using the inter-bone distance algorithm. The results from this study agree with the results of previous studies examining joint contact at the elbow both in the location and in the tracking of the joint contact throughout elbow flexion. Ultimately, this technique will lead to an increased understanding of the effect of malalignment and instability of the joint on contact mechanics.     

活动半月板单髁关节置换术治疗膝骨性关节炎早期疗效分析

目的：分析活动半月板单髁关节置换术治疗膝关节骨关节炎的早期临床效果。方法：2009年6月至2010年2月,采用OXFord活动半月板单髁关节治疗膝骨性关节炎患者23例25膝。结果：23例患者（25膝）随访3-8个月,无感染、假体位置不良及松动等并发症。HSS评分由术前56.9分提高至术后93.3分。结论：活动半月板单髁关节置换术治疗膝骨性关节炎短期疗效优良,成功的关键在于适应证的把握和手术技术的掌握,其远期疗效仍需观察。     

Development of software for human muscle force estimation

Muscle force estimation (MFE) has become more and more important in exploring principles of pathological movement, studying functions of artificial muscles, making surgery plan for artificial joint replacement, improving the biomechanical effects of treatments and so on. At present, existing software are complex for professionals, so we have developed a new software named as concise MFE (CMFE). CMFE which provides us a platform to analyse muscle force in various actions includes two MFE methods (static optimisation method and electromyographic-based method). Common features between these two methods have been found and used to improve CMFE. A case studying the major muscles of lower limb of a healthy subject walking at normal speed has been presented. The results are well explained from the effect of the motion produced by muscles during movement. The development of this software can improve the accuracy of the motion simulations and can provide a more extensive and deeper insight in to muscle study.     

Design of a cylindrical brachytherapy implant applicator for the irradiation of an intestinal segment in mice

YingExperimental determination of the RBE of new isotopes for brachytherapy implants (e.g. iodine-125 and palladium-103) remains a very difficult problem, especially in small animals, where the seeds cannot be implanted easily in the planned geometry in a reproducible way. This technical note describes an original device that makes it possible to irradiate a segment of the intestine in mice for the purpose of determining the RBE for crypt regeneration. The device is a length of tube (3.4 mm and 7 mm internal and external diameter, respectively) whose external surface has been longitudinally grooved and into which the seeds can be squeezed (each groove holds either one or two seeds). The tube is composed of two sections. This seed container can be surgically positioned around an intestinal ansa while the mice are anesthetized. The mean dose rates in the intestine (for eight seeds) were found to be 86.3 +/- 5.9 and 79.0 +/- 5.4 cGy/h for 29.2 MBq (1 U) iodine and 28.6 MBq (1 U) palladium seeds, respectively. So far, more than 100 mice have been irradiated successfully. Full dose-effect relationships can be obtained using the same seeds and applying them successively in different groups of animals (which ensured the accuracy of the relative doses).     

双极人工股骨头置换治疗老年不稳定股骨粗隆间骨折的临床研究

目的:通过观察我院老年不稳定股骨粗隆间骨折患者临床治疗资料,探讨分析采用双极人工股骨头置换治疗该疾病的临床效果.方法:将我院收治的100例该疾病患者按照手术方法平分为A组与B组两组,分别进行双极人工股骨头置换术与动力髋螺钉手术治疗,对比分析使用两种方法手术时间、出血量情况、术后并发症以及治疗效果等.结果:两组患者经各自手术治疗后,临床症状均有改善,A组患者在手术时间、出血量情况与B组患者相比,差异不显著(P＞0.05),而在术后并发症、髋关节功能对比方面,A组优于B组,差异具有显著性(P＜0.05).结论:采用双极人工股骨头置换手术治疗老年不稳定股骨粗隆间骨折患者,手术并发症少,安全可靠性高.有效改善患者髋关节功能,临床效果显著,值得临床上推广与进一步研究.     

人工股骨头置换与动力髋螺钉内固定用于老年股骨头转子间骨折治疗的疗效比较

目的：比较人工股骨头置换术与动力髋螺钉内固定治疗老年股骨头转子间骨折的临床疗效。方法：选择我院74例老年股骨头转子间骨折患者作为观察对象,随机分为A组（人工股骨头置换术）和B组（动力髋螺钉内固定术）,每组37例。比较两组患者的手术时间、术中出血量、术后卧床时间、术后Harris评分及术后并发症和死亡率。结果：手术时间和术后卧床时间A组明显短于B组（P〈0．05）,A组术中出血量较B组明显减少,差异显著（P〈0．05）。术后1、3个月Harris评分A组均高于B组（P〈0．05）;术后6个月Harris评分两组无明显差异（P〉0．05）。结论：与动力髋螺钉内固定术相比,人工股骨头置换术术后可更早负重、恢复好,而且并发症少,是较为理想的治疗老年股骨头转子间骨折的治疗方法。     

Extrapolation of an empirical elbow muscle co-activation relationship to a novel task set: implications for predictions of individual muscle demands

Biomechanical optimisation models applying efficiency-based objective functions often underestimate antagonist contributions. Previous work has quantified an empirical co-activation relationship in the elbow musculature, demonstrating that implementing this relationship as a constraint in an elbow muscle force prediction model improves muscle force predictions. The current study evaluated this modified model by extrapolating the co-activation relationship to 36 novel isometric unilateral, right-handed exertions, including those requiring greater intensity of effort and performed in different postures. Surface electromyography was recorded from the elbow flexors and extensors. Novel extrapolative co-activation relationships were developed and used as constraints in a muscle force prediction model. Model predictions using both constraints were compared with empirical biophysical data. Predictions by the modified model were more consistent with biophysical data than those by the original model for the novel exertions. Novel co-activation relationships did not further enhance predictions when compared with the previous relationship, suggesting that extrapolation of the previous relationship is feasible.     

Simulating the GRF of Humanoid Robot Vertical Jumping Using a Simplified Model with a Foot Structure for Foot Design

There are many theories and tools for human or robot motion simulation,but most of them require complex calculations.The LNZN model(a simplified model named by the proposers)simplifies the human model and facilitates simulation of the Ground Reaction Force(GRF)of body landing by spring damping model and ignoring joint rotation movements,which can reduce the amount of computation obviously.In this paper,the LNZN model of human running is selected as the basis and is modified to obtain the LNZN model of a robot,which expands the application of the LNZN model.According to the structure of the human foot,a foot structure is then added to the simplified model to reduce the GRF.We also applied driving forces to the new model to simulate the whole high jump motion of the robot to expand the functions of the LNZN model.The obtained GRF data were anastomotic to the actual experimental results.In addition,the effects of variables,such as the mass,hardness,and damping,of the foot on the GRF at the moment of landing were also explored.Finally,based on the guidelines obtained for the design of the robot's foot structure,we fabricated new robot's feet and installed them on the actual robot and achieved a better cushioning effect than the original foot in experiments.     

Modification of an effector strain for replacement therapy of dental caries to enable clinical safety trials

AIMS: To construct a genetically modified strain of Streptococcus mutans for dental caries prevention. The strain has significantly reduced cariogenicity owing to a deletion of the entire open reading frame for lactate dehydrogenase, and has excellent colonization potential through the production of a natural antibiotic called mutacin 1140. For use in human clinical trials, additional mutations were introduced to enable rapid elimination of the strain in case of adverse side effects and to increase genetic stability. METHODS: Deletion mutations were introduced into the dal gene for d-alanine biosynthesis and the comE gene for genetic transformation. The resulting strain, A2JM, was tested for dependence on exogenous d-alanine and its ability to be eradicated from colonized rats. The strain was also tested for its ability to exchange DNA with another strain of S. mutans in in vitro and in vivo models. CONCLUSIONS: A2JM was completely dependent on exogenous d-alanine, but could colonize the oral cavity of rats in low numbers in the absence of dietary d-alanine. Results indicated that A2JM can scavenge d-alanine from other plaque bacteria. Lowering of the total oral bacterial load through daily application of chlorhexidine enabled virtually complete eradication of A2JM. The introduction of the comE gene did not significantly decrease the transformability of A2JM in in vitro or in vivo models. The addition of a deletion in the comE gene does, nonetheless, provide additional safety as it has a very low reversion frequency. SIGNIFICANCE AND IMPACT OF THE STUDY: Based on the safety and efficacy profiles established in vitro and in animal models, A2JM appears suitable for safe use in human clinical trials.     

Development of an indirect method for measuring porcine pancreatic lipase in human duodenal fluid

Patients with exocrine pancreatic insufficiency are usually treated with porcine pancreatic enzymes but the bioavailability of these enzymes in the gut remains a matter of discussion. In order to determine the duodenal availability of porcine pancreatic lipase (PPL) present in pancreatic extracts (PE) taken orally, we developed a method for quantifying PPL in samples containing both PPL and human pancreatic lipase (HPL). Total pancreatic lipase activity measurements using the pH-stat technique and tributyrin as substrate were combined with an HPL-specific ELISA. Based on the known specific activity of the purified HPL, its activity was deduced from the ELISA measurements, and the PPL activity was obtained by subtracting the HPL activity from the total pancreatic lipase activity. This assay was established and validated using various samples containing pure PPL and recombinant HPL or PE, mixed or not with human duodenal juice. Samples collected in vivo from patients treated with PE were also tested. It was found that PPL did not affect the HPL ELISA, and the indirect PPL assay gave a measurement accuracy of 6.6% with the samples containing pure PPL and 10% with those containing PE. This assay was also used successfully to discriminate between PPL and the endogenous HPL present in the duodenal contents of patients with severe pancreatic insufficiency treated with PE. This method might provide a useful means of assessing the availability of PEs at their site of action, in the absence of a PPL-specific ELISA.     

Design,synthesis and biological evaluation of deuterated Vismodegib for improving pharmacokinetic properties

Vismodegib is an oral and high selective hedgehog (Hh) inhibitor used for the treatment of basal cell carcinoma (BCC). In this work, analogs of Vismodegib with deuterium-for-hydrogen replacement at certain metabolically active sites were prepared and found to have a better pharmacokinetic properties in mice. In particular, deuterated compound SKLB-C2211 obviously altered the blood circulation behavior compared to its prototype, which was demonstrated by significantly prolonged blood circulation half-life time (t_1/2) and increased AUC_0→∞. These results suggested SKLB-C2211 had the potential to be a long-acting inhibitor against Hh signaling pathway, and laid the foundation for the further research of its druggability.     

Emerging Paradigms for Synthetic Design of Functional Amyloids

Many living organisms make use of diverse amyloid proteins as functional building blocks to fulfill a variety of physiological applications. This fact, along with the intrinsic self-assembly and outstanding material properties of amyloids, has prompted a significant amount of research in the synthetic design of functional amyloids to form diverse nanoarchitectures, molecular materials, and hybrid or composite materials. In particular, a new research paradigm has recently been advanced that uses synthetic biology to harness functional amyloids with cells as living materials or functional devices. Here we outline important progress in the synthetic design of functional amyloids, in the context of both non-living and living systems. We propose several important tools and underline emerging techniques and principles that might be useful in advancing the future synthetic design of functional amyloids.     

Design of an Optimized Scaffold for Affibody Molecules

Affibody molecules are non-immunoglobulin-derived affinity proteins based on a three-helical bundle protein domain. Here, we describe the design process of an optimized Affibody molecule scaffold with improved properties and a surface distinctly different from that of the parental scaffold. The improvement was achieved by applying an iterative process of amino acid substitutions in the context of the human epidermal growth factor receptor 2 (HER2)-specific Affibody molecule Z_HER2:342. Replacements in the N-terminal region, loop 1, helix 2 and helix 3 were guided by extensive structural modeling using the available structures of the parent Z domain and Affibody molecules. The effect of several single substitutions was analyzed followed by combination of up to 11 different substitutions. The two amino acid substitutions N23T and S33K accounted for the most dramatic improvements, including increased thermal stability with elevated melting temperatures of up to + 12 °C. The optimized scaffold contains 11 amino acid substitutions in the nonbinding surface and is characterized by improved thermal and chemical stability, as well as increased hydrophilicity, and enables generation of identical Affibody molecules both by chemical peptide synthesis and by recombinant bacterial expression. A HER2-specific Affibody tracer, [MMA-DOTA-Cys61]-Z_HER2:2891-Cys (ABY-025), was produced by conjugating MMA-DOTA (maleimide-monoamide-1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) to the peptide produced either chemically or in Escherichia coli. ABY-025 showed high affinity and specificity for HER2 (equilibrium dissociation constant, K_D, of 76 pM) and detected HER2 in tissue sections of SKOV-3 xenograft and human breast tumors. The HER2-binding capacity was fully retained after three cycles of heating to 90 °C followed by cooling to room temperature. Furthermore, the binding surfaces of five Affibody molecules targeting other proteins (tumor necrosis factor α, insulin, Taq polymerase, epidermal growth factor receptor or platelet-derived growth factor receptor β) were grafted onto the optimized scaffold, resulting in molecules with improved thermal stability and a more hydrophilic nonbinding surface.     

Development of real-time PCR methods for the rapid detection of low concentrations of Gluconobacter and Gluconacetobacter species in an electrolyte replacement drink

AIMS: To develop a rapid real-time polymerase chain reaction (PCR) method to detect Gluconobacter and Gluconacetobacter species in electrolyte replacement drinks. METHODS AND RESULTS: Samples of electrolyte replacement drinks were artificially contaminated with Gluconobacter species and then filtered to collect cells. DNA was extracted from the filters and analysed by real-time PCR on the ABI Prism 7000 system, using commercial detection kits for lactic and acetic acid bacteria. In addition, specific primers and Taqman probe were designed and used for the detection of seven Gluconobacter and Gluconacetobacter species. All the assays tested demonstrated a linear range of quantification over four orders of magnitude, suggesting detection levels down to 1 CFU ml(-1) in the original drink. CONCLUSIONS: A real-time PCR method was developed to detect low concentrations of Gluconobacter and Gluconacetobacter sp. in an electrolyte replacement drink. SIGNIFICANCE AND IMPACT OF THE STUDY: Real-time PCR methods allow a rapid, high throughput and automated procedure for the detection of food spoilage organisms. The real-time PCR assay described is as sensitive as the conventional method that involves pre-enrichment, enumeration on a selective agar (typically malt extract agar) and identification with a differential medium (typically Wallerstein nutrient agar). The real-time PCR assay also provides a more rapid rate of detection, with results in less than 24 h following enrichment for Gluconobacter and Gluconacetobacter species.     

A quantitative ultramorphological approach for systematic assessment of sperm head regions: an example in rams

Examination of the type and frequency of damage to the head of spermatozoa using electron microscopy can be used to evaluate the quality of differently treated sperm. This report describes a systematic approach based on 29 morphological categories of sperm heads assessed from discrete regions in raw, chilled and frozen-thawed spermatozoa. Injury occurred principally at the plasma membrane and could be present or absent in all regions. In the anterior segment, when the plasma membrane is present, it can be intact, dilated, very dilated, disrupted, or contain vesicles characteristic of acrosomal reaction-like capacitation changes. When the plasma membrane is absent, the acrosome may be intact, exhibit a complete loss of contents, or retain some contents of the apical ridge and present a very dilated outer acrosomal membrane. The plasma membrane in the equatorial segment and the boundary between regions can be intact, dilated, very dilated or disrupted. The post-acrosomal plasma membrane is classified as intact, dilated or very dilated, whereas the dense lamina is intact, dilated or fragmented. The morphology of the heads most frequently observed in chilled spermatozoa consists of anterior and equatorial segments with a dilated, or dilated and disrupted plasma membrane; a boundary between regions with an intact and dilated plasma membrane; and a post-acrosomal region with an intact plasma membrane and dense lamina, both dilated. In frozen-thawed spermatozoa, the morphology of the heads is more frequently characterised by no plasma membrane and an acrosome showing complete or some loss of contents in the apical ridge and very dilated outer acrosomal membrane, presenting mostly dilated and fragmented dense lamina in the post-acrosomal region. These findings are consistent with the conclusion that the freezing process produces an increase in the degree of damage to the cells when they are subjected to increasing degrees of cold shock. There are still difficulties in developing a good diluent and process for preserving the plasma membrane in ram spermatozoa. This systematisation, using different categories, allows characterisation of multiple transmission electron microscopy images. Thus, the different changes observed due to cryopreservation may be correlated.     

Application of Novel Design Bone Grafting for Treatment of Segmental Acetabular Rim Defects During Revision Total Hip Arthroplasty

The study aimed to develop efficient techniques with different novel graft structures to enhance the treatment of acetabular bone deficiency.The inhomogeneous material properties Finite Element Analysis(FEA)model was reconstructed according to computed tomography images based on a healthy patient without any peri-acetabular bony defect according to the Ameri-can Academy of Orthopedic Surgeons(AAOS).The FEA model of acetabular bone deficiency was performed to simulate and evaluate the mechanical performances of the grafts in different geometric structures,with the use of fixation implants(screws),along with the stress distribution and the relative micromotion of graft models.The stress distribution mainly con-centrated on the region of contact of the screws and superolateral bone.Among the different structures,the mortise-tenone structure provided better relative micromotion,with suitable biomechanical property even without the use of screws.The novel grafting structures could provide sufficient biomechanical stability and bone remodeling,and the mortise-tenone structure is the optimal treatment option for acetabulum reconstruction.     

Analysis and Design of an Agent Searching Algorithm for e-Marketplaces

Recently, agent techniques in electronic marketplaces (e-marketplaces) bring B-to-B trading into a new era. However, not much analysis on the behavior of agents has been reported. In this paper, based on the ant algorithm in network routing, we introduce a jumping (searching) model for agents in an e-marketplace network. However, we should be aware that if there are too many agents in the e-marketplace network, they will use up all communication bandwidth and computing resource. It is inevitable to investigate the behavior of agents, such as agent population. Based on the existing results in the ant algorithm in network routing, we present the behavior of agents in an e-marketplace network. Hence, we can control the agent population by setting the appropriate agent generation rate.     

Design of an efficient fermentation process for the production of Metarhizium acridum blastospores

Using a sequential approach, we described efficient blastospore production in a stirred tank bioreactor (3?L capacity). We used the response surface methodology to optimise the media ingredients and fermentation parameters to obtain the maximum production of blastospores by a locally collected isolate of Metarhizium acridum (Ascomycota: Hypocreales). The results showed that a liquid culture medium supplemented with monopotassium phosphate (15.17?g/L), corn steep liquor (69.25?g/L), and casamino acids (80.68?g/L) in a stirred tank bioreactor under operating conditions constant at 635?rpm, a temperature of 26°C, and pH 3.3 produced 1.25?×?10⁸?blastospores (bls)/ml, with 93% viability after 120?h of fermentation. This bioreactor yield compares favourably with the yields obtained by shake flask production and confirms the suitability of the media and production parameters for the potential scale-up fermentation production of M. acridum.