Kidney xenotransplantation: Future clinical reality or science fiction?

There is a global shortage of organs for transplantation and despite many governments making significant changes to their organ donation systems, there are not enough kidneys available to meet the demand. This has led scientists and clinicians to explore alternative means of meeting this organ shortfall. One of the alternatives to human organ transplantation is xenotransplantation, which is the transplantation of organs, tissues, or cells between different species. The resurgence of interest in xenotransplantation and recent scientific breakthroughs suggest that genetically engineered pigs may soon present a realistic alternative as sources of kidneys for clinical transplantation. It is therefore important for healthcare professionals to understand what is involved in xenotransplantation and its future implications for their clinical practices. First, we explore the insufficiency of different organ donation systems to meet the kidney shortage. Second, we provide a background and a summary of the progress made so far in xenotransplantation research. Third, we discuss some of the scientific, technological, ethical, and public health issues associated with xenotransplantation. Finally, we summarize the literature on the attitudes of healthcare professionals toward xenotransplantation.     

Immunochemically unreactive albumin in urine: fiction or reality?

Urinary albumin measurements are currently not standardized due to a lack of a reference method and reference (primary and secondary [matrix]) material. Multiple molecular forms of albumin in urine are identified. Modification of albumin by proteolysis during passage through the urinary tract and chemical modification during specimen storage leads to the formation of albumin fragments. Multiple methods have been developed to quantify albuminuria and significant different results are reported dependent on the available assay. The current point of view of the National Kidney Disease Education Program - IFCC Working Group on Standardization of Albumin considers the immunoassay with polyclonal sera as the primary method of quantifying urine albumin. This article reviews the process of albumin fragmentation and focuses on the controversial topic of immuno-unreactive, nonimmunoreactive, or immunochemically nonreactive albumin fractions and its consequences for albumin analysis. We conclude that at present there are no hard arguments for measuring immunochemically unreactive albumin in urine. Immunoassays using polyclonal antisera for the detection of urinary albumin remain the gold standard. The development of a reference measurement procedure remains one of the challenges for the future.     

Cardiogenic shock: thrombolysis or angioplasty?

Cardiogenic shock (CGS) occurs in 3 to 20% of patients presenting with acute myocardial infarction (MI), and it generally involves dysfunction of at least 40% of the total myocardial mass. Prior to the advent of balloon angioplasty and thrombolysis, in-hospital mortality was greater than 75%. This mortality rate has been consistent in reported series despite the advent of cardiac intensive care units, vasopressor, inotropic, and vasodilator therapy. Intra-aortic balloon counterpulsation therapy provides hemodynamic improvement, and it may provide some mortality benefit when used in conjunction with appropriate revascularization. Survival studies have shown that patency of the infarct-related artery is a strong predictor of survival. No randomized trials have been completed to examine which reperfusion therapy best treats this emergent situation. Subgroup analysis of large scale, multicenter trials, although underpowered, has shown no improvement in mortality with use of thrombolytic agents, leading many to advise use of mechanical intervention. In patients who present with acute MI with contraindications to thrombolysis, primary angioplasty is the treatment of choice. At selected centers, primary angioplasty is comparable to or better than thrombolytic therapy for patients presenting with acute MI, with or without CGS. Studies examining angioplasty in patients with CGS have shown high procedural success rates (75%) and reduced in-hospital mortality (44%), particularly in those patients with successful revascularization. Emergency bypass surgery may improve survival, but it is costly, unavailable to many, and often leads to excessive delays in therapy. If available, we believe that primary angioplasty is the treatment of choice for patients with CGS.     

Science or fiction?

Nurses reflect on what health care and nursing might be like in the year 2068.     

Sulfonamide cross-reactivity: fact or fiction?

OBJECTIVE: To provide a critical and comprehensive review of the literature, specifically case reports and observational studies used to support the concept of cross-reactivity between sulfonylarylamines and non-sulfonylarylamines. DATA SOURCES: A list of medications was formulated from several different review articles. A MEDLINE/PubMed search was conducted (1966-March 2004) using the individual medications and the MeSH terms of drug hypersensitivity/etiology, sulfonamides/adverse effects, and/or cross-reaction. STUDY SELECTION AND DATA EXTRACTION: A critical review of the methodology and conclusions for each article found in the search was conducted. The manufacturer's package insert (MPI) for each drug was examined for a statement concerning possible cross-reactivity in patients with a sulfonamide allergy. If indicated, the manufacturers were contacted to obtain any clinical data supporting the statement. DATA SYNTHESIS: A total of 33 medications were identified. Seventeen (51.5%) of the MPIs contained statements of varying degrees concerning use in patients with a "sulfonamide" allergy; 21 case series, case reports, and other articles were found. CONCLUSIONS: After a thorough critique of the literature, it appears that the dogma of sulfonylarylamine cross-reactivity with non-sulfonylarylamines is not supported by the data. While many of the case reports on the surface support the concept of cross-reactivity, on closer examination the level of evidence in many of the cases does not conclusively support either a connection or an association between the observed cause and effect.     

Herbal or complementary medicine: fact or fiction?

Although herbal medications have been used in medical therapy since the dawn of civilization, they have not undergone careful scientific assessment. Some herbal derivations are exceptional and have become standard therapy in cardiovascular disease; eg, digitalis, reserpine, and aspirin. The high prevalence of herbal use around the world and in the United States today may have a negative impact on patient care when herbal preparations are used in combination with medications ordered by healthcare providers who are not advised of the patient's use of herbs. Healthcare providers need to be familiar with all herbal medications in order to prevent potentially serious reactions between conventional and herbal medications. They should be asking patients about herbal use when first obtaining a medical history. Patients who use alternative therapies do not tell their healthcare providers about such use.     

Clopidogrel resistance: myth or reality?

Platelets have a central role in the development of arterial thrombosis and subsequent cardiovascular events. An appreciation of this complex process has made antiplatelet therapy the cornerstone of cardiovascular disease management. Dual antiplatelet therapy with aspirin and clopidogrel has been approved for the secondary prevention of cardiovascular events and is currently part of the postpercutaneous coronary intervention treatment regimen. However, subacute stent thrombosis continues to occur in 1% to 2% of patients despite dual antiplatelet therapy. Studies have shown interindividual variations in response to clopidogrel, where a cohort of patients seems to be resistant to the antithrombotic effects of clopidogrel. Furthermore, there is an apparent link between clopidogrel resistance and clinical outcomes. Currently, there is neither a universally accepted definition of clopidogrel resistance nor an agreement on the phenomenon's mechanism. This review highlights the origins of clopidogrel resistance, the current problems that exist with its definition, and discusses the future implications and relevant challenges it poses for the clinician.     

Nurse-academics' mentorship: rhetoric or reality?

Mentorship is generally identified in nursing literature as a positive strategy, and one that is said to be beneficial in increasing scholarly productivity. However, previous studies investigating the relationship of mentoring to scholarly productivity have produced equivocal findings. This relationship was examined as part of a study that considered constraints and/or facilitators of scholarly productivity among nurse academics. A survey questionnaire technique was used to establish current scholarly productivity levels, and frame and factor facilitating theory and analysis to identify major constraints and facilitators. Findings showed that while the majority of participants perceived mentoring as important to developing and increasing scholarly productivity, this was less so as academic rank increased. More than a quarter reported never having had a mentor. The burden of teaching and administrative over-load, and a cultural climate of non-support, were described as major disincentives to mentoring. Mentoring was more likely to occur where a collaborative and collegial network to support scholarly productivity existed. However, often it was seen as not available. A workplace environment that is appropriately supported by adequate resources may be as important as the research training that can occur through mentoring.