End-stage renal disease (ESRD) and vascular access grafting: a critical review.

End-Stage Renal Disease (ESRD) is a major disease state, costing the U.S. $9.5 billion in 1992, and increasing 10% yearly. The growth in the number of ESRD patients can be attributed principally to demographic trends: the aging of the general population and the improved treatment and increased survival rate of patients with diabetes, hypertension, and other illnesses that lead to ESRD. Moreover, improved dialysis technology has enabled older patients and those who previously could not tolerate dialysis due to other illnesses to benefit from this treatment. Three modalities exist for the treatment of ESRD: hemodialysis, peritoneal dialysis, and kidney transplant. This article reviews the medical treatments and the synthetic polymers used in the manufacture of vascular access grafts. We report on the development of a new, polyurethane-based microporous vascular graft, which displays self-sealing and improved compliance characteristics for use in vascular access grafting.     

Mechanical properties of bone cement: a review

Many authors have examined the mechanical properties of bone cement and the various factors that affect its mechanical behavior. This article presents a comprehensive survey on the reported mechanical properties of bone cement. Variables that influence the mechanical properties, such as handling characteristics, strain rate, loading modes, additives, porosity, blood inclusion, in vivo environment, temperature, etc. have also been reviewed. The importance of specifying these variables in reporting test results on the mechanical properties of bone cement is pointed out. Previous attempts to improve the mechanical properties of bone cement are also summarized. Future research areas important for fully characterizing the physical properties of PMMA are also suggested.     

Mechanical properties of the aorta: a review

Measurement and calculation of the mechanical properties of the aorta depend on a number of factors, including the degree of surgical invasion, vasomotor tone, tissue hydration, physical contact (i.e., the presence of a strain gauge), and the use of inside or outside diameter. Measurements on the aorta using angiography, transit-time determination, and echocardiographic techniques yield the most consistent values for parameters, including PVD, Ep, and Eo. Values of these parameters are listed in Table 7 and range from about 8 to 12.0% (PVD), 337 to 741 g/cm2 (Ep), and 0.33 to 3.6 x 10(6) dyn/cm2 (Eo) for human ascending aorta. Measurements made with invasive techniques tend to result in lower values of PVD and higher values of elastic moduli. Modeling studies focus on predicting the mechanical properties of a viscoelastic, anisotropic tube. Difficulty arises in modeling aorta because of hysteresis and the large deformations that are associated with physiologic loading patterns. Various forms of the strain-energy density function have been used to model relationships between stress and strain in three dimensions; however, they have limited value in understanding the mechanism of time-dependent stress transfer between fibrous and nonfibrous components found in aortic tissue. The ultimate utility of these models will include improved understanding of the physical basis of deformation of this important tissue and the mechanisms of premature failure associated with different disease processes.     

Psychosocial issues in palliative care: a review of five cases

Palliative care is not just vital in controlling symptoms of the patient's disease condition, but also aims to extend the patient's life, giving it a better quality. However, several times in the course of management, the psychosocial impact of cancer, HIV/AIDS, and other life-limiting disease conditions may not be noticed and dealt with during the admission period, thereby giving rise to a more complex situation than the disease condition itself. This article aims to review some psychosocial issues and measures that can be taken to address them. It highlights the various roles and the importance of the clinician, nurse, social worker, and other members of the multidisciplinary team in tackling these issues and will help healthcare professionals in this field achieve better practice in the future.     

Clinical issues in the use of carbamazepine in psychiatry: a review

Evidence is presented here in support of the efficacy of carbamazepine (CBZ) in a variety of different psychiatric conditions. While there is now considerable evidence to support the use of CBZ in the acute treatment of mania and in the prophylaxis of bipolar affective disorder, particularly as a second-line drug, its usefulness in other conditions is less well documented. Overactivity, aggression and poor impulse control appear to improve in a variety of different diagnostic categories, and it may possibly be more appropriately prescribed to control or prevent these symptoms than as a treatment for a particular disease entity. The use of CBZ as an anti-depressant is not well proven. Most of the adverse effects reported are due to rapid initial escalation of dosage, which can be avoided, or are reversible such as drug rashes. Severe adverse effects have been reported but are rare. Frequent monitoring of drug plasma concentration is not required. Some reports of synergism with lithium have appeared and combination therapy may be a useful strategy. Drug interactions, the need for clinical monitoring, and the possible pharmacological mode of action of CBZ are also discussed.     

细胞因子与大脑间的联系——对目前文献的评论

在超过二十年的时间里细胞因子一直是个多学科研究的焦点。到目前为止关于细胞因子与中枢神经系统间相互关系的文章已经发表了超过15000篇了。这其中超过半数的文章是在最近5年中发表的。在这样众多的研究中突现出了两个重大问题:(1)细胞因子是如何调节中枢神经系统的功能的?(2)在神经性疾病的发病原因中细胞因子扮演什么样的角色?目前,细胞因子已被证明可以以特殊的方式改变中枢神经系统的功能,如涉及到中枢神经系统控制的自主神经、神经内分泌以及行为反应等。大脑受伤与感染后也在中枢神经系统中发现了被诱导表达的细胞因子,在这个免疫特权部位有了免疫过程。此外,越来越多的证据显示在一大批神经性疾病:从早老性痴呆到慢性疲劳症候群当中,细胞因子都有潜在的参与。尽管取得了这样的进步,但是对于细胞因子与中枢神经系统间的交互作用的基本理解与其潜在的临床开发依然是困难重重。在本篇回顾中,我们将尝试着对涉及回答了上述重要问题的现有理论及证据做个摘要。以往,大部分的原始报告都只关注某一个问题,而我们这次的回顾将对这些文献进行了平行的比对,得到更多的信息。     

Somatization: a critical review of conceptual and methodological issues

Despite its apparent clinical importance and the extensive research that has been conducted in the past decades, somatization remains a complex concept. Two distinct ways of looking at somatization can be distinguished: somatization as a phenomenon that is secondary to psychological distress (presenting somatization) and somatization as a primary phenomenon characterized by medically unexplained symptoms (functional somatization). The literature was analyzed in terms of this distinction and a selective review was conducted, focusing on a critical analysis of conceptual and methodological issues related to presenting and functional somatization. A number of measurement issues related to somatization in general were also highlighted. On the basis of the available data, the strengths and weaknesses of different concepts are pointed out. Conclusions are formulated regarding which concepts or approaches might be useful both clinically and from a research perspective. Finally, a number of suggestions for future research are offered.     

Hybrid small-caliber vascular prosthesis for coronary artery bypass grafting: a preliminary study of plasmin-treated fibrin-coated vascular prosthesis

The potential use of plasmin-treated fibrin-coated vascular prosthesis (PF-V) for coronary artery bypass grafting (CABG) in animal models was investigated. PF-V grafts, 3 mm in internal diameter, were studied on 5 sheep in off-pump CABG model and on 18 rabbits in abdominal aortic bypass grafting (AABG) model. Patency, blood flow, angiography, Indium-111 platelet scintigraphy, and histology of the graft were evaluated. In the sheep CABG model, the PF-V grafts were patent for a range of 12 to 22 days without postoperative antiplatelet therapy. Graft flows ranged 58 to 90 ml/min until the day before graft occlusion by thrombus. In rabbit AABG model, the fibrin coating of the PF-V grafts was completely absorbed and replaced with neofibrin net between 7 and 14 days after implantation. Platelet depositions on the graft between 7 and 14 days after implantation were significantly higher than those at other periods (p < 0.05). The small-caliber PF-V graft in sheep CABG model had a good blood flow with high antithrombogenicity in acute phase, but occluded over 2 to 3 weeks without antiplatelet agents after implantation. The current problem of the PF-V graft was a thrombus formation at the time of the degradation of fibrin coating. Further improvements are needed.     

Patient and public education for cholesterol reduction: a review of strategies and issues.

Elevated blood cholesterol is a major risk factor for coronary heart disease and a significant public health problem, affecting as many as 50% of all adults in the U.S. Public, professional and patient education are central to current widespread efforts to increase awareness and effective management of high cholesterol. Screening/case-finding, follow-up and nutrition education are the most widely applicable strategies for cholesterol reduction. The following topics are reviewed: current guidelines for treatment of elevated cholesterol levels; trends in awareness, attitudes and practices of the public and health professionals; reports of interventions for cholesterol reduction; and health policy issues and research needs related to cholesterol education. This review suggests that several major challenges lie ahead for widespread and effective educational management of high cholesterol levels. These include development of practical screening and education systems, establishment of feasible financing arrangements, effective communication of complex information to patients, and techniques for long-term maintenance of reductions in cholesterol levels.     

The cutaneous neutrophilic vascular injury syndromes: a review

The skin manifestations of vasculitis reflect injury by all of the classic immune reactions of Gell and Coombs. As the skin affords a window of opportunity for the clinician to obtain tissue for diagnostic purposes in patients with systemic vasculitic syndromes, a thorough understanding of the dermatopathologic manifestations of those systemic diseases is a considerable asset to the practicing pathologist. This review focuses on those systemic diseases that can provoke a small vessel neutrophilic injury pattern in the skin and provides clues by which these diseases can be separated from each other and from their innocuous mimics in which cutaneous vascular injury is the only significant consequence.     

The mechanical behavior of vascular grafts: a review

The development of intimal hyperplasia (IH) near the anastomosis of a vascular graft to artery is directly related to changes in the wall shear rate distribution. Mismatch in compliance and diameter at the end-to-end anastomosis of a compliant artery and rigid graft cause shear rate disturbances that may induce intimal hyperplasia and ultimately graft failure. The principal strategy being developed to prevent IH is based on the design and fabrication of compliant synthetic or innovative tissue-engineered grafts with viscoelastic properties that mirror those of the human artery. The goal of this review is to discuss how mechanical properties including compliance mismatch, diameter mismatch, Young's modulus and impedance phase angle affect graft failure due to intimal hyperplasia.     

Mechanical circulatory support systems--a review.

Congestive Heart Failure (CHF) is a major health problem with a high mortality rate. Its ultimate therapy, heart transplantation, is limited by the shortage of donor hearts. Since decades researchers have been working to solve this problem by developing Mechanical Circulatory Support Systems (MCSS) that can replace or assist the failing heart. Short-term and intermediate-term ventricular assist devices are used nowadays frequently to bridge patients with severe heart failure to recovery. Long-term ventricular assist devices (VADs) and Total Artificial Hearts (TAHs) are used increasingly as a bridge to heart transplantations or as permanent circulatory support in patients with end-stage heart failure that are contraindicated for heart transplantation. The early TAHs and VADs were mainly driven from an external pneumatic drive unit. The latest generation TAHs and long-term assist devices are electrically powered, ultracompact, totally implantable, and have small wearable drive/control consoles, allowing patients to return to their daily activities. The article categorizes and reviews the development of MCSS, highlights the medical indications and contraindications of pump implantation, advantages and disadvantages of the various systems, and results of animal and clinical studies.     

Scope of policy issues in eHealth: results from a structured literature review

Background

eHealth is widely used as a tool for improving health care delivery and information. However, distinct policies and strategies are required for its proper implementation and integration at national and international levels.

Objective

To determine the scope of policy issues faced by individuals, institutions, or governments in implementing eHealth programs.

Methods

We conducted a structured review of both peer-reviewed and gray literature from 1998–2008. A Medline search for peer-reviewed articles found 40 papers focusing on different aspects of eHealth policy. In addition, a Google search found 20 national- and international-level policy papers and documents. We reviewed these articles to extract policy issues and solutions described at different levels of care.

Results

The literature search found 99 policy issues related to eHealth. We grouped these issues under the following themes: (1) networked care, (2) interjurisdictional practice, (3) diffusion of eHealth/digital divide, (4) eHealth integration with existing systems, (5) response to new initiatives, (6) goal-setting for eHealth policy, (7) evaluation and research, (8) investment, and (9) ethics in eHealth.

Conclusions

We provide a list of policy issues that should be understood and addressed by policy makers at global, jurisdictional, and institutional levels, to facilitate smooth and reliable planning of eHealth programs.     

Management of vascular birthmarks: review of a multidisciplinary clinic

Vascular birthmarks comprise a diverse group of congenital lesions and represent a significant cosmetic and functional burden for patients. They remain a diagnostic and management challenge for physicians due to their extremely variable clinical presentation and often complex anatomical associations. As each type of vascular lesion has a treatment program individual to it, optimal functional and cosmetic outcomes require accurate diagnosis. Primary physicians readily diagnose and manage uncomplicated lesions, such as isolated haemangiomas and innocuous capillary malformations. However, given the complexity and relative rarity of many other vascular birthmarks, specialised multidisciplinary clinics are central to their management. In this review, we present our experience regarding the diagnostic range of vascular anomalies, associated symptomatology, and management of patients with vascular birthmarks attending the multidisciplinary Joint Vascular Birthmark Clinic at Our Lady's Children's Hospital, Crumlin. Vascular tumours represented 57% of cases reviewed, malformations accounting for 43%. Of patients not previously seen at the JVBC or by any of the individual consultants, the initial or referring diagnosis was incorrect in 42%. Significantly, 62% of vascular malformations were assigned an incorrect diagnosis, highlighting the need for a specialised clinic.     

Mechanical vascular changes and hypertension: pathological consequences

Arteries are more than simple conduits for blood, they are a functionally active part of the cardiovascular system. Their mechanical performance is preserved at different levels of blood pressure and adapts to progressive increases but this functional change is accompanied by wall changes (e.g. medial thickening, scleroprotein increase) which have pathological effects. The way in which these changes are brought about is discussed.     

Mechanical analysis of a prototype of small diameter vascular prosthesis: numerical simulations

This paper concerns a mechanical analysis of a prototype of a small diameter vascular prosthesis made of a fibre reinforcement silicone material. The theoretical approach is carried out for a neoHookean strain energy function augmented with unidirectional reinforcing that is characterized by a single additional constitutive parameter for strength of reinforcement. Numerical simulations based on a finite element model compare the compliance of different grafts and predict the degree of the compliance mismatch in an anastomosis between native artery and vascular prosthesis. Furthermore, specific applied strains on the prototype, viewed as arising surgical manipulation and implying telescopic shear have been simulated. Thus, for different fibre reinforcements, the stress gradient through the wall of the tubular structure is evaluated.     

Coiled-coil-mediated grafting of bioactive vascular endothelial growth factor

Chimeric growth factors may represent a powerful alternative to their natural counterparts for the functionalization of tissue-engineered scaffolds and applications in regenerative medicine. Their rational design should provide a simple, readily scalable production strategy while improving retention at the site of action. In that endeavor, we here report the synthesis of a chimeric protein corresponding to human vascular endothelial growth factor 165 being N-terminally fused to an E5 peptide tag (E5-VEGF). E5-VEGF was successfully expressed as a homodimer in mammalian cells. Following affinity purification, in vitro surface plasmon resonance biosensing and cell survival assays confirmed diffusible E5-VEGF ability to bind to its receptor ectodomains, while observed morphological phenotypes confirmed its anti-apoptotic features. Additional surface plasmon resonance assays highlighted that E5-VEGF could be specifically captured with high stability when interacting with covalently immobilized K5 peptide (a synthetic peptide designed to bind to the E5 moiety of chimeric hVEGF). This immobilization strategy was applied to glass substrates and chimeric hVEGF was shown to be maintained in a functionally active state following capture. Altogether, our data demonstrated that stable hVEGF capture can be performed via coiled-coil interactions without impacting hVEGF bioactivity, thus opening up the way to future applications in the field of tissue engineering and regenerative medicine.