The availability and use of abdominal diagnostic ultrasonography or computed tomography has led to the frequent detection of asymptomatic renal cysts. The vast majority of these are simple cysts that ...are usually unilateral and solitary with well-defined structural and imaging features and whose occurrence, number, and bilaterality increase with age. Simple cysts are asymptomatic, except when complications such as hemorrhage, infection, or rupture lead to the development of complex cysts with calcification, demarcation irregularities, and multilobularity. The diagnostic challenges that cysts present are in the differentiation of the less common complicated complex cysts from those associated with malignancy and when numerous the possible heralding of genetic or acquired multicystic diseases of the kidney.
Diseases of the kidney are old, but the discipline dedicated to their study, nephrology, is barely more than 50 years old. As recounted in this recollection of those events, the rudiments of what ...would become nephrology emerged in the time between the 2 World Wars from basic studies of normal kidney function and flourished after the integration of their methodologies into clinical medicine thereafter. Although shaped by studies of kidney function in the 1960s, it was the subsequent advent of dialysis that fueled the growth of nephrology well into the 21st century. Although to some extent this growth was a product of technical developments (micropuncture, dialysis, biopsy, etc), it was the paradigm shifts they engendered that brought about the revolutionary changes that stimulated the growth of nephrology from its formative years in the 1960s. Notable among those was the classification of chronic kidney disease on the basis of kidney function, calculated from serum creatinine level as estimated glomerular filtration rate, that has expanded nephrology’s interaction with and integration into other disciplines and begat the recent outpouring of epidemiologic and interventional studies, thereby establishing it as a leading discipline dedicated to improving outcomes for individuals with kidney disease worldwide.
To a great extent, the conceptual evolution of acid-base homeostasis has been shaped by progress in chemistry. It began in the theoretical consideration of matter by the natural philosophers of ...antiquity, progressed into an observational craft as chymistry in the Scientific Revolution, evolved into analytical chemistry in the Enlightenment when acid-alkali interactions began to be deciphered, then clearly exposed in the organic chemistry of the 19th century, and ultimately formulated in mathematical precision as the chemical equations of physical chemistry in the 20th century. Two principal transformational changes shaped their clinical application. The first, launched by the Chemical Revolution of Antoine Lavoisier introduced quantitation, clarified the language and added experimental rigor to chemical studies, which Claude Bernard then introduced into physiology, formulated the concept of regulatory homeostasis, refined experimental medicine and explored the role of the kidney in acid-base balance. The second transformational change in their gradual clinical applicability began in electrochemical studies that revived atomic composition of matter and introduced the notion of ions and electrolytes that were fundamental in formulating the concept of acid-base ionization by Svante Arrhenius in 1884 and their measurement from hydrogen ion concentration as pH by Søren Sørensen in 1909. Subsequent studies of Lawrence J. Henderson and Donald D. van Slyke introduced these laboratory-based conceptual advances to the bedside in the 20th century. Clinical studies of acidosis and alkalosis that followed over the past few decades have facilitated and refined the clinical recognition, interpretation and treatment of acid-base disorders.
Definition and classification of chronic kidney disease: A position statement from Kidney Disease: Improving Global Outcomes (KDIGO). Chronic kidney disease (CKD) is a worldwide public health ...problem, with adverse outcomes of kidney failure, cardiovascular disease (CVD), and premature death. A simple definition and classification of kidney disease is necessary for international development and implementation of clinical practice guidelines. Kidney Disease: Improving Global Outcomes (KDIGO) conducted a survey and sponsored a controversies conference to (1) provide a clear understanding to both the nephrology and nonnephrology communities of the evidence base for the definition and classification recommended by Kidney Disease Quality Outcome Initiative (K/DOQI), (2) develop global consensus for the adoption of a simple definition and classification system, and (3) identify a collaborative research agenda and plan that would improve the evidence base and facilitate implementation of the definition and classification of CKD.
The K/DOQI definition and classification were accepted, with clarifications. CKD is defined as kidney damage or glomerular filtration rate (GFR) <60 mL/min/1.73 m2 for 3 months or more, irrespective of cause. Kidney damage in many kidney diseases can be ascertained by the presence of albuminuria, defined as albumin-to-creatinine ratio >30 mg/g in two of three spot urine specimens. GFR can be estimated from calibrated serum creatinine and estimating equations, such as the Modification of Diet in Renal Disease (MDRD) Study equation or the Cockcroft-Gault formula. Kidney disease severity is classified into five stages according to the level of GFR. Kidney disease treatment by dialysis and transplantation should be noted. Simple, uniform classifications of CKD by cause and by risks for kidney disease progression and CVD should be developed.
Long considered an inert supporting framework, bone studies went neglected until the 17th century when they began as descriptive microscopic studies of structure which over time progressed into that ...of chemistry and physiology. It was in the mid-19th century that studies evolved into an inquisitive discipline which matured into the experimental investigation of bone in health and disease in the 20th century, and ultimately that of molecular studies now deciphering the genetic language of bone biology. These fundamental studies were catalyzed by increasing clinical interest in bone disease. The first bone disease to be identified was rickets in 1645. Its subsequent connection to albuminuric patients reported in 1883 later became renal osteodystrophy in 1942, launching studies that elucidated the functions of vitamin D and parathyroid hormone and their role in the altered calcium and phosphate metabolism of the disease. Studies in osteoporosis and renal osteodystrophy have driven most recent progress benefitting from technological advances in imaging and the precision of evaluating bone turnover, mineralization, and volume. This review exposes the progress of bone biology from a passive support structure to a dynamically regulated organ with vital homeostatic functions whose understanding has undergone more revisions and paradigm shifts than that of any other organ.
•The study of bone in health and disease went neglected until the 17th century.•Research began in bone structure evolving to chemistry and then physiology.•Studies of rickets, renal osteodystrophy, and osteoporosis catalyzed discoveries.•Technological advances were instrumental in its recent progress.•Bone has evolved from a passive support structure to a vital endocrine organ.
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