In a former paper it was concluded that an actual physical alteration of the tissues is brought about by the toxic substances retained in the blood owing to the insufficient action of the kidneys. This alteration leads to (edema, on the one hand, and to a rise of arterial press , urc, on the other, due to increased periph eral resistance. From this follows the hypertrophy of the heart.
This theoretical view now confirmed by actual experiment. Physiological so dium-chloride solution was injected hypo dermically in cases of nephritis without (edema, and it was found that the arti ficial (edema thus produced was not ab sorbed for from five to ten days, while if the same were done in non-nephritic cases, even when heart disease was pres ent, it disappeared in a few hours, or in three days at the latest. This proves that the absorptive power of the sub cutaneous tissue is much restricted in Bright's disease. Reichel (Centralb. f. inn. Med., Oct. 15. 'OS).
The growth of fibrous tissue in the walls of the arteries, causing sclerosis, forms an important change in most instances. The intima (endarteritis), media, and adventitia are all thickened by the hyperplasia of connective-tissue elements, and the arteries and capillaries are, in this way, mostly occluded by the obliterating endarteritis or by their conversion into connective tissue. Waxy or hyaline degeneration is also seen. These changes may sometimes form the primary condition that leads to granular and contracted kidneys, and may repre sent the renal effects of a general arterio sclerosis.
In a ease of interstitial nephritis ter minating in cerebral atrophy, aneurismal dilatations of the cerebral arteries ob served, besides an luemorrhagic area filled with fluid blood, which might have been taken for an aneurism, which was in reality due to rupture of the artery and successive haemorrhages into the cerebral substances. Israel (Berliner klin. Woch., Jan. 29, '94).
The urea introduced into the circula tion leads to a constriction of the vessels of the periphery. Retention of urea causes elevation of vascular pressure and is the cause of cardiac hypertrophy in patients with Bright's disease. Chia ruttini (Inter. klin. Ruud., Feb. 18, '94).
Cardiac hypertrophy is an almost con stant attendant upon chronic, non-exu dative, productive nephritis, and its de gree depends upon the extent of the renal, and also of the general arterial, degeneration and sclerosis. Cor bovinum
has been applied to the organ, on ac count of its extreme size in this affection. The left ventricle only is hypertrophied in moderate enlargements.
Among the many complications of chronic Bright's disease may be men tioned cirrhosis of the liver, pulmo nary emphysema, cerebral haemorrhage, chronic endocarditis, endarteritis, peri carditis, and bronchitis.
Prognosis. — Chronic interstitial ne phritis varies in duration, and in uncom plicated cases it may last for five, ten, twenty, or possibly thirty years. The duration may, however, be very much shortened by complications or intercur rent affections, or the condition may not be appreciated, as often occurs, when the post-mortem examination discovers the characteristic kidneys in one who had no symptoms of renal disease dur ing life and whose death was directly due to some intercurrent affection. Life is destroyed sooner or later by this dis ease, unless the patient first dies from some intercurrent malady. Irreparable damage to the organs results from the gradual destruction of the renal paren chyma and its replacement by scar-tissue. The fact, however, that the process is slow and its duration, therefore, long allows a preservation of life for many years, and often with comparative com fort. The prognosis depends much upon the general condition of the patient, the cardiovascular system, and upon the presence of uremia and inflammatory complications. A not far distant end is indicated by cardiac dilatation and in sufficiency. diarrhoea, persistent vomiting, nephritic retinitis, coma, and delirium render the prognosis exceedingly grave. Convulsive and apo plectic seizures are often fatal.
Hmmaturia, a frequent accompaniment of nephritis, is of grave import. Case of Bright's disease kept in comparatively good health by strict attention to diet and climate several years. As soon as hfematuria appeared, however, he rapidly lost ground and died. Any appearance of blood, however slight, in chronic nephritis denotes an early demise. Dieu lafoy (Jour. de Med., May 10, '97).