Proteomics in nephrology: current status and future directions

Proteomics is one among various 'OMICS' fields that have been growing rapidly in the postgenomic era. During the past few years, proteomics has been extensively applied to several fields of medicine to better understand normal physiology, to define the pathophysiology of diseases, and to identify novel biomarkers and new therapeutic targets. This review focuses on current status and future directions of proteomics in the nephrology field. Recent studies of renal proteome, proteomes of individual intrarenal structures (i.e., glomerular, vascular, tubular, brush border membrane, mesangial, and podocyte proteomes), urinary proteome, and protein profiles in dialysate or ultrafiltrate removed by renal replacement therapy are summarized.     

Levosimendan: current status and future prospects

PURPOSE OF REVIEW: While patients with acute heart failure typically receive diuretics and vasodilators, contractile dysfunction and peripheral hypoperfusion also leads to a widespread use of inotropic agents despite the lack of evidence for efficacy or safety. Levosimendan, a calcium sensitizer and vasodilator, has been proposed to be superior to standard inotropes. In addition, further possible indications for levosimendan have been described, such as perioperative use, cardioprotection, cardiogenic shock, sepsis, and right ventricular dysfunction. RECENT FINDINGS: The mortality benefit of levosimendan has not been confirmed in two recent trials but the substance improves symptoms, decreases brain natriuretic peptide and is effective during beta-blocker treatment. The use of levosimendan as an add-on therapy in acute heart failure has been encouraged as well as its perioperative use. Levosimendan may also be useful during right ventricular dysfunction and septic shock due to its favorable effects on splanchnic perfusion. SUMMARY: Levosimendan is an established substance in the treatment of acute heart failure in several countries despite disappointing findings concerning a possible survival benefit in two recent clinical trials. Owing to its alternative mechanisms of action as compared with traditional cardiotonic agents, several promising clinical applications have arisen. Available evidence for the use of levosimendan in settings other than decompensated heart failure is currently limited.     

Interventional nephrology in Puerto Rico

Vascular access is emerging as a critical issue for hemodialysis patients in Puerto Rico. In more than 50% of the hemodialysis patients, tunneled hemodialysis catheters are the sole access for providing dialysis therapy. Most disturbing is the fact that a significant number of these catheters are nontunneled temporary catheters, sometimes placed in the subclavian vein. These facts have contributed significantly to the morbidity and mortality seen in chronic dialysis patients. In addition, many cases of early or late dysfunction of arteriovenous access are not detected and treated in a timely manner due to the lack of a comprehensive vascular access program for end-stage renal disease (ESRD) patients. In fact, monitoring programs to identify and detect vascular access dysfunction are virtually nonexistent in many chronic dialysis units. Even when diagnosed, it is not treated in a timely fashion. Recently literature has shown that procedure-related delays in the treatment of patients with renal disease can be minimized and nephrology care more efficiently delivered by a nephrologist trained in nephrology-related procedures. In an effort to optimize the care of our ESRD patients, we took the initiative to develop an interventional nephrology program that effectively deals with vascular access-related procedures in a timely manner. This approach has minimized delays, decreased hospitalizations and the use of temporary catheters, and improved the medical care of our chronic dialysis patients. So far we have performed more than 400 procedures in the 6 months since the initiation of the program. In this article we describe our initial experience with interventional nephrology in Puerto Rico.     

Posthumous reproduction: current and future status

Posthumous reproduction became possible with the technologies of sperm cryopreservation and ART. The legal and social status of children born as a result of these technologies continue to evolve. The proper disposition of unwanted stored gametes and embryos remains unknown. Physicians are increasingly asked to make quick judgments on posthumous gamete retrieval. The procedures for gamete harvest are technically simple; however, one must carefully select cases with definitive prior intent to have children. There is a need for standardized legal protocols to protect the physician and the patient. The physician must use sound judgment and comply with accepted standards, when present, before performing any service for posthumous sperm retrieval and reproduction.     

Liver transplantation: current status and future prospects

The enormous progress that has been made in liver transplantation over the past two decades has culminated in survival approaching 90% at 12 months. The success of the procedure combined with the widening spectrum of disease processes deemed amenable to liver transplantation has meant that there are too few donors for those awaiting transplantation. This has extrapolated to many patients having such advanced disease by the time a suitable donor liver is available, that they are almost non-transplantable. The immediate options facing the transplant community are to decrease the number of patients listed or to increase the number of living donor transplants. Alternatives to liver transplantation such as hepatocyte transplantation, gene therapy, xenotransplantation and the bioartificial liver are being sought but, at best, are some way from clinical application. It is anticipated that a number of liver diseases that are indications for liver transplantation at this time will have progression arrested or will be cured by medical therapy in the future.     

Organ transplantation in mice: current status and future prospects

With the development of microsurgery and molecular biology in the 1990s, the mouse model for organ transplants has become increasingly popular. In the past 10 years, the number of studies using the mouse model has increased three-fold. All the organ transplants, originally done in the rat model, can now be performed in mice with high success rates. This article reviews the development, advantages, limitations, and unique immunology of the mouse model as well as future prospects.     

Artificial urinary sphincter:current status and future directions

Urge urinary incontinence(UUI)is one of the most troublesome complications of surgery of the prostate whether for malignancy or benign conditions.For many decades,there have been attempts to reduce the morbidity of this outcome with variable results.Since its development in the 1970s,the artificial urinary sphincter(AUS)has been the“gold standard”for treatment of the most severe cases of UUI.Other attempts including injectable bulking agents,previous sphincter designs,and slings have been developed,but largely abandoned because of poor long-term efficacy and significant complications.The AUS has had several sentinel redesigns since its first introduction to reduce erosion and infection and increase efficacy.None of these changes in the basic AUS design have occurred in the past three decades,and the AUS remains the same despite newer technology and materials that could improve its function and safety.Recently,newer compressive devices and slings to reposition the bladder neck for men with mildto-moderate UUI have been developed with success in select patients.Similarly,the AUS has had applied antibiotic coating to all portions except the pressure-regulating balloon(PRB)to reduce infection risk.The basic AUS design,however,has not changed.With newer electronic technology,the concept of the electronic AUS or eAUS has been proposed and several possible iterations of this eAUS have been reported.While the eAUS is as yet not available,its development continues and a prototype device may be available soon.Possible design options are discussed in this review.     

The bioartificial kidney: current status and future promise

The rapid understanding of the cellular and molecular bases of organ function and disease processes will be translated in the next decade into new therapeutic approaches to a wide range of clinical disorders, including acute and chronic renal failure. Central to these new therapies are the developing technologies of cell therapy and tissue engineering, which are based on the ability to expand stem or progenitor cells in tissue culture to perform differentiated tasks and to introduce these cells into the patient either via extracorporeal circuits or as implantable constructs. Cell therapy devices are currently being developed to replace the filtrative, metabolic, and endocrinologic functions of the kidney lost in both acute and chronic renal failure. This review summarizes the current state of development of a wearable or implantable bioartificial kidney. These devices have the promise to be combined to produce a wearable or implantable bioartificial kidney for full renal replacement therapy that may significantly diminish morbidity and mortality in patients with acute or chronic kidney disease.     

Airway research: the current status and future directions

We highlight the areas we think important for future development of the subspeciality. The ultimate goal is to improve patient care and safety and to do this, we need to identify how and where episodes of harm arise. Simply continuing with current practice does not represent the best path towards our ultimate goal; objective evidence is needed to inform changes in practice.     

Minimally invasive oesophagectomy: current status and future direction

Background  

Oesophagectomy is one of the most challenging surgeries. Potential for morbidity and mortality is high. Minimally invasive techniques have been introduced in an attempt to reduce postoperative complications and recovery times. Debate continues over whether these techniques are beneficial to morbidity and whether oncological resection is compromised. This review article will analyse the different techniques employed in minimally invasive oesophagectomy (MIO) and critically evaluate commonly reported outcome measures from the available literature.     

Carotid artery stenting: current status and future directions

Carotid endarterectomy has been the mainstay of therapy for carotid occlusive disease in stroke prevention. Recent advances in endovascular technology has made carotid angioplasty and stenting a therapeutic modality in the treatment of carotid occlusive disease. The enthusiasm for this minimally invasive carotid intervention is hampered by the possibility of stent-related cerebral embolization, which can result in neurologic complications. Although current available data indicate that the results regarding success and complication rates are similar between carotid stenting and endarterectomy, numerous prospective clinical trials are currently underway to evaluate the efficacy of carotid artery stenting using various forms of cerebral protection devices. This article reviews the current status of carotid stenting, including recent clinical studies and ongoing prospective trials. Strategies relating to cerebral embolization protection are also discussed.