Kidney Replacement

Signs and symptoms of uremia are foundational to the decision to implement kidney replacement therapy. 

The artiflcial kidney replaces the function of the natural kidney to eliminate waste metabolites from the body. The main waste metabolite is urea. 

Preparation for kidney failure and kidney replacement therapy... 

Other Uquid separation systems using membranes include dialysis and electrodialysis, where the driving force is now a concentration difference between the two sides of the membrane. The main use for dialysis is in blood processing, as a kidney replacement or booster, but both processes are also being used industrially, electrodialysis especially in desalination. 

Other surgical implants are essentially plastic repair products for worn out parts of the body. It is possible to conceive of major replacements of an entire organ such as a kidney or a heart by combining the plastic skills with tissue regeneration efforts that may extend life. This is used to time the heart action. Extensively used are plastic corrugated, fiber (silicone or TP polyester) braided aortas (24). 

While it would be difficult to enumerate all of the efforts in the area of implants where plastics are involved, some of the significant ones are (1) the implanted pacemaker, (2) the surgical prosthesis devices to replace lost limbs, (3) the use of plastic tubing to support damaged blood vessels, and (4) the work with the portable artificial kidney. The kidney application illustrates an area where more than the mechanical characteristics of the plastics are used. The kidney machine consists of large areas of a semi-permeable membrane, a cellulosic material in some machines, where the kidney toxins are removed from the body fluids by dialysis based on the semi-permeable characteristics of the plastic membrane. A number of other plastics are continually under study for use in this area, but the basic unit is a device to circulate the body fluid through the dialysis device to separate toxic substances from the blood. The mechanical aspects of the problem are minor but do involve supports for the large amount of membrane required. 

Kidney For organ replacement due to end-stage organ diseases... 

Medicine has made major advances in the past 50 or so years partly by the use of devices to improve patient health. These devices include artificial hearts and pacemakers, machines for artificial kidney dialysis, replacement joints for hips, knees, and fingers, and intraocular lenses. These devices need to survive in sustained contact with blood or living tissue. 

C04-0026. Cadmium ions are environmental pollutants found in mining waste, metal plating, water pipes, and industrial discharge. Cadmium ions replace zinc ions in biochemistry and cause kidney damage, high blood pressure, and brittle bones. Dissolved Cd " " impurities can be removed from a water sample... 

Desirudin is a SC administered DTI approved for VTE prevention after hip replacement surgery but is not yet commercially available in the United States. Desirudin has an elimination half-life of 2 to 3 hours and is typically dosed every 12 hours. It is primarily eliminated through the kidneys, so dose reduction is needed in patients with renal impairment. The aPTT should be used to measure desirudin s anticoagulant activity.29,38,41... 

Patients who progress to ESRD require renal replacement therapy (RRT). The modalities that are used for RRT are dialysis, including HD and peritoneal dialysis (PD), and kidney transplantation. The United States Renal Data Service (USRDS) reported that the number of patients with ESRD was 452,957, with 102,567 new cases being diagnosed in 2003.2 The most common form of RRT is dialysis, accounting for 72% of all patients with ESRD. The principles and complications associated with dialysis are discussed below. Chapter 52 discusses the principles of kidney transplantation. 

Osteoporosis Oral calcium supplementation (1000-5000 mg/day) Oral vitamin D Calcifediol (1000 lU/day) Calcitriol (0.5 mcg/day) Hormone-replacement therapy Calcitonin or oral bisphosphonates If daily intake less than 1000 mg elemental calcium Documented deficiency If kidney functioning If kidney not functioning Post-menopausal women without contraindications Documented loss in bone mineral density greater than 3% Data lacking for bisphosphonates in patients with Rl... 

Many of the initial biopharmaceuticals approved were simple replacement proteins (e.g. blood factors and human insulin). The ability to alter the amino acid sequence of a protein logically coupled to an increased understanding of the relationship between protein structure and function (Chapters 2 and 3) has facilitated the more recent introduction of several engineered therapeutic proteins (Table 1.3). Thus far, the vast majority of approved recombinant proteins have been produced in the bacterium E. coli, the yeast S. cerevisiae or in animal cell lines (most notably Chinese hamster ovary (CHO) cells or baby hamster kidney (BHK) cells. These production systems are discussed in Chapter 5. 

Chronic kidney disease (CKD) is a progressive loss of function over several months to years, characterized by gradual replacement of normal kidney architecture with interstitial fibrosis. 

Lead (soft, Pb2+) Injuries to peripheral nervous system, disturbs heme synthesis and affects kidneys Pb2+ may replace Ca2+ with loss of functional and structural integrity. Reacts with sulfhydryl groups, replaces Zn2+ in 8-aminolevulinic acid dehydratase. 

The first ever injectable crude biomaterial, that is a dental implant, appeared early in ad 6oo (Fig. 12.1). During those times, Mayan people trimmed seashells into artificial teeth to replace missing teeth (Michael, 2006 Ratner et al., 2004). Early biomaterials also led to problems, including sterilization, toxicity, inflammation, and immunological issues. Since the Mayan s initial use of artificial teeth, biomaterials have evolved to be used in modem artificial hearts, hip and knee pros-theses, artificial kidneys, and breast implants. Materials used in these applications include titanium, silicons, polyurethanes, teflon, polybiodegradable polymers, and most recently bio-nanomaterials (Pearce et al., 2007)... 

As a molecule passes from tissue to tissue via the blood, it is exposed to hxmdreds of possible metabolic sites it can be bound to protein, fat, or other molecules in the serum it can be sequestered in certain organs or excreted via the kidneys, the colon, or even the breath, at rates and by mechanisms that we simply do not completely xmderstand. Faced with these facts, how can anyone state dogmatically that we can replace intact animals with computers, bacteria, cell cultures, etc. ... 

Unless the last-mentioned product is removed by the inclusion of catalase, the oxoacid is liable to react further, undergoing oxidative decarboxylation to the carboxylic acid. An attractive feature of this group of enzymes in the present context is that there exist readily available representatives of both enantiospecificities. The well-studied and commercially available AAOs from vertebrate sources, such as l-AAO from snake venom and D-AAO from pig kidney, are expensive, however, and are increasingly being replaced by enzymes from microbial sources. 

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