KIDNEYS, DISEASES OF. The principal disease to which the kidneys are liable is that which gives rise to the formation of calculi. [Cstcetrs.] Sometimes the stone ie retained in the pelvis of the kidney, where, by continued depositions, it may increase till it com pletely fills the pelvis and calyces; but more frequently it passes through the ureters into the bladder, producing in its passage violent spasmodic pain in the loins, sickness and nausea, haemorrhage, &c. This affection is the most common cause of inflammation of the kid neys (nephritis), from which abscess and other morbid alterations may result.
An affection of the kidneys, having very definite symptoms, and exhibiting uniformity of structural change, was first pointed out by Dr. Bright of Guy's Hospital, and is generally called after him. This disease is also called Alliuminuria and granular disease of the kidney; the first on account of its diagnostic symptom, albumen in the urine, the second on account of the morbid condition presented by the kidney. This formidable disease presents several stages or varieties, and some discussion has taken place as to whether the symptom of albumen in the urine may not occur in several distinct morbid con ditions of the kidney. There is no doubt that albumen may be found in the urine in even functional derangements of the kidney ; but the term Bright's Disease is very conveniently applied to all those forms of structural change in the kidney which are accompanied with albuminous urine.
The great symptoms accompanying this disease vary according to the intensity of the disease and the condition of the patient. One of the first symptoms to which the physician's attention is usually drawn, is the presence of dropsy. This may occur in the skin or in any of the cavities of the body. It is frequently noticed in the face ; and in all varieties of this disease an effusion of fluid is observed underneath the conjunctiva, producing the appearance of a watery eye. In addition to dropsical effusions, inflammatory affections of the mucous and serous membranes are very common accompaniments of Bright's Disease.
The heart also is frequently affected, and pericarditis and endoearditis are observed. Affections of the brain are also not unfrequently present, especially In the more severe cases arising from the poisoned condition of the blood.
In all cases of this disease, the urine contains albumen. This is easily detected either by coagulating the albumen by heat or nitric acid. The specific gravity of the urine is also decreased, being some times as low as 1.010, whilst healthy urine has a specific gravity of P020. It contains less urea than healthy urine. Under the micro scope it also presents appearances indicative of the nature of the disease. These appearances consist of casts of the minute tubes of the kidneys, formed by substances produced in various stages of the disease. They are thus classified by Dr. Bennett :— 1. Erlulatire casts, consisting of the coagulated exudation or fibrin which is poured into the tube during the inflammatory stage.
2. Desguamatire casts, consisting of masses of the epithelium lining the tubes, and occurring in all stages of the disease.
3. Fatty casts, consisting of patches of epithelium as in the last, but which have undergone a fatty transformation by the accumulation of a greater or less number of fatty granules in its cells.
4. Waxy casts, presenting an exceedingly diaphanous and structure leafs substance. They are frequently associated with the two last.
Dr. Bright originally described three stages of this disease, but later observers have recognised six.
1. The catarrhal form, in which the kidneys are enlarged, and con tain an increased quantity of blood. In this stage only a small quantity of urine is passed, containing the exudative and disquamative casts.
2. In this stage the kidney is enlarged to nearly double its size and is white and granular in its appearance. The tubes of the kidney are obliterated by the inflammatory deposit. The urine is very albuminous, and of light specific gravity.