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AMYLOID DEGENERATION OF THE KIDNEYS. 379
the patients are in a state of great marasmus. There are cases, where the whole extent of the digestive tract from the buccal cavity to the anus does not contain a single minute artery, which is not affected with this disease, and where in every part of the oesophagus, stomach, small and large intestines, the small arteries of its mucous membrane are found changed in this way.
Now this state of things is very apt to escape observation, because this kind of metamorphosis, which exercises such a decided influence upon the functions of the intestines (causing deficiency of absorption, and tendency to diarrhoea), produces scarcely any effect perceptible to the naked eye. The intestines are pale and have a grey, translucent, sometimes slightly wax-like appearance; but this, however, is so little characteristic, that no inference can with certainty be drawn from it with regard to the internal changes, and the only possibility of determining the point, when one has no microscope at hand, consists in the direct application of the test. One need only brush a little iodine upon the surface, and a number of densely aggregated, yellowish- or brownishred spots are soon seen to start up, whilst the interjacent mucous membrane merely looks yellow. These red points are the villi of the intestine, and if one of them be placed under the microscope, the walls of the small arteries and even of the capillaries, which ramify in them, and sometimes also the parenchyma, are seen to be coloured iodine-red.
The most important disturbances of this kind with which we are as yet acquainted, are those which arise in the kidney. A large proportion of the cases of Bright's disease, especially of the chronic ones, are assignable to this change, and must therefore be separated from many other similar forms as constituting a special, altogether peculiar affection. Kidneys affected in this way were called in Vienna, at a time when the chemical reaction was not yet known, lardaceous kidneys (Specknieren). I must however again remark that it is impossible to distinguish immediately with the naked eye, whether this particular change has taken place or not, and that a part of the socalled lardaceous kidneys exhibit nothing more than a kind of induration. Not until iodine has been employed, can a diagnosis be readily made. If a solution of iodine be applied to a quite anaemic cortex, a number of red points usually first appear which correspond to the glomeruli, and sometimes fine streaks also, which are the afferent arteries; and next to this, when the disease is very severe, red parallel lines are also seen within the medullary cones, lying very close to one another. These are all arteries. The affection of the arteries becomes sometimes so severe, that, after the application of the test, a clear view of the whole course of the vessels is obtained, as if one had a very complete artificial injection before one. But in these very kidneys an injection is hardly practicable. Even the finer materials which we employ as injections, are much too coarse to be able to pass through the narrowed vessels. Upon examining one of these glomeruli microscopically, we see that from the point, where the afferent artery breaks up, the loops are no longer the fine, delicate tubes that they formerly were; on the contrary they appear compact and nearly solid. Now as these are just the parts which manifestly constitute the real points at which the secretion of the fluid portion of the urine is effected, we can easily conceive that in such cases disturbances in the secretion of urine must arise. Unfortunately we have as yet no completely satisfactory analyses, but it seems that many cases of albuminuria, which are attended with a considerable diminution in the secretion of urea, are connected with these very conditions, and that the excretion becomes more and more scanty in proportion as the disease increases in intensity.1 These cases are
1 This is what we might expect to take place, wherever we suppose the urea to be secreted. If it is secreted by the epithelium, the epithelium must take it up out of the blood which circulates in the intertubular capillaries. But if the glomeruli only allow a small quantity of blood to pass through them, a small quantity only finds its way into these capillaries, and so but little urea can be taken up and excreted. In those cases in which there is an abundant flow of watery urine, the water is chiefly derived from the vessels of the medullary substance, in consequence of the increased (collateral) pressure upon them. Thus the amyloid degeneration of the Malpighian bodies and their afferent arteries has much less influence upon the excretion of water, than upon that of urea. The peculiar views first put forward by the Author concerning the circulation in the medullary substance of the kidney, and the common origin (from the same branches of the renal artery) of the arteria recta? of the medullary cones (pyramids), and of the afferent arteries of the cortex, whereby, in the case of a diminished flow of blood through the latter set of vessels, an increased circulation takes place through the former—will be found in his Archiv f. path. Anat. und Phys. vol. xii, p. 310, and investigations confirmatory of them have recently been published by Dr. Beale (Arch. of Med., 1859, No. IV, p. 300. According to those (e. g., Bowman) who make all the arterial blood pass through the glomeruli, no such collateral relationship could exist between the cortex and medulla.—From a MS. note by the Author.
AMYLOID DEGENERATION OF THE KIDNEYS. 381
very frequently complicated with anasarca and with dropsy of the different cavities, and mayexhibitin thecompletestmanner all the symptoms of Bright's disease. They differ however essentially from the simply inflammatory form of Bright's disease, which I designate parenchymatous nephritis, in this respect, that in the latter the disease has not so much its seat in the glomeruli or the arteries, as in the epithelium of the kidney, and that the change is often for a long time confined to the epithelium, whilst the glomeruli themselves may in such cases still appear unchanged when there is scarcely any epithelium remaining in the substance of the cortex. From these forms a third again must be distinguished, where the interstitial tissue is predominantly affected, where thickenings take place around the capsules and iiriniferous tubules, constrictions and contractions are effected, and thereby mechanical obstructions to the current of the blood are produced, which must naturally be attended by secretory changes.
It is very important that you should discriminate between these different varieties which exist in what is apparently a single disease, because you will hence see how it is that the facts which have been ascertained concerning the one class cannot forthwith be applied to the other classes, and that neither the same physiological inferences nor the same therapeutical maxims are equally applicable in every one of these several conditions. At the same time, however, it must not be overlooked that these three different forms by no means always appear unmixed, but that on the contrary frequently two, and sometimes all three, of them exist simultaneously in the same kidney.
Amongst the other preparations which I place before you I have, especially on account of its distinctness, chosen the amyloid disease of the lymphatic glands. In these the state of things is much the same as in the spleen. We see on the one hand the small arteries, on the other the essential substance of the glands (i. e., the mass of minute cells which fill the follicles), undergoing the change. You will remember from a previous occasion (p. 174, Fig. 61), that there are follicles lying beneath the proper capsule of the gland, and that these follicles are made up of a delicate network, in which the small cells of the gland are heaped up, cells, which seem to have a double duty to perform, inasmuch as they discharge their own special functions as gland-cells, and at the same time, as we suppose, serve as the starting-points for the development of blood-corpuscles. The arteries run first in the interstices of the follicles, and there break up into capillaries which form a web round the follicles, and sometimes even penetrate into their interior. Now the amyloid disease consists on the one hand in a thickening and narrowing of these arteries, so that they convey less blood, and on the other hand in the conversion of the small cells contained in the individual meshes of the follicles into corpora amylacea, so that afterwards instead of a number of cells in every mesh of the follicles, a single large corpus amylaceum is met with. Thereby the gland acquires even to the naked eye the appearance as if it were
AMYLOID DEGENERATION OF THE LYMPHATIC GLANDS. 383
sprinkled all over with little spots of wax, and when examined microscopically, it looks as if the contents of the follicles were a pavement of closely set stones.
Concerning the importance of these changes, empirically not much can be affirmed; but, if the contents of the follicles are the essential components of a lymphatic gland, and if from them proceeds the development of the new constituents of the blood, we must, I think, conclude, that this disease of the lymphatic glands and the spleen (in which the follicles are likewise generally affected), must exercise a directly injurious influence upon the formation of the blood; and that the effects therefore produced by the disease are not remote ones, but that the formation of the blood im
Fig. 122. Amyloid degeneration of a lymphatic gland, from a drawing made by Dr. Pripp of Bristol, a, b, b. Vessels with greatly thickened, shining, infiltrated walls. c. A layer of fat-cells at the circumference of the gland. d, d. Follicles with their delicate reticulum and corpora amylacca. 200 diameters. Compare Wiirzburger Verhandlungcn, Vol. VII, Plate III.
Fig. 123. Isolated corpora amylacca of different sizes, some of them ruptured, from the gland represented in Fig. 122. 350 diameters.