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A A HISTOPATHOLOGICAL STUDY OF THE BOVINE KIDNEY A HISTOPATHOLOGICAL STUDY OF THE BOVINE KIDNEY ‘I'IESIS Submitted to the faculty of the Michigan State College in partial fulfillment of the requirements for the degree of Master of Science in Animal Pathology by Otto Herbert iylth THESTS‘ CONTENTS Introduction Literature Materials and Hethods Histological Studies Group I Study of Kidneys from Normal Animals Group II Study of the Effect of Variations in Techniques on the Microsc0pic Structures of Kidney Tissue Discussion of Histological Findings in Kidneys from Groups I and II Group III Study of {ldneys from Cows Affected with Mastitis Discussion of Findings in Kidneys from Group III Summary and Conclusions Plates Acknowledgment References 98866 INTRODUCTION This investigation was undertaken for the purpose of determining some of the histological detail of the bovine kidney and for the study of pathological alterations flaund in kidneys from cattle affected with streptococcic mastitis. Since in the study of disease, knowledge of the histological structures of the organs involved is of cardinal importance, an attempt has been made to study these normal structures and to record the findings. The effects of streptococci and their products, cir- culating in the blood stream, on the renal parenchyma of man and the common laboratory animals is well known. It would not be illogical to expect that in sudh a disease as strep- tococcic mastitis of cattle, in Which there are undoubtedly great quantities of toxic substances from.streptococci&, if not the organisms themselves, in the blood stream.for long periods, there might be considerable reaction on the part of the renal tissue. LITERATURE Although there is abundant literature on the histology of the renal mechanism.of man and some of the common lab- oratory and lower animals, there seems to have been little written on the subject as regards the domestic animals. Nething has been found in the available literature on the finer histological detail of the bovine kidney. The same can be said in regard to the effects of strep- tococci and their toxins on the renal tissue. The problem has been recognized and studied in man, supplemented by the common laboratory animals, for years. In the case of the domestic animals the subject has apparently attracted little attention. Nothing has been found in the available. lit- erature relative to the reaction of the renal tissues of the bovine kidney to streptococci and their products. MATERIALS AND LE THO DS The tissues for this study were selected from two types of cases. Those selected for histological study were obtained from apparently normal animals. The others were obtained from animals with a history of streptococcic mastitis. In some cases the tisstes were collected prior to the beginning of this study and the identification of right and left kidneys was not kept. In three cases only a single block of tissue was obtained. In the remaining cases two or there blocks of tissue were obtained fran each kidney. The blocks of tissue were taken as soon after slaughter as possible and fixed in Zenker's solution, followed by the paraffin technique. Sections 8 microns in thickness were made. Sons were stained with eosin—hematoxylin. (Unless otherwise stated references will be made to this method of staining.) Others were stained with Mallory's aniline blue. In one case Gram's stain for bacteria was employed. In two cases blocks from each kidney were also fixed in 10% formalin, frozen, sectioned at 15 microns thickness and stained for fat with Sudan IV. In two cases a single block from one kidney was fixed in Zenker's solution, and another block from the adjacent area fixed in formalin for 24 hours, then fixed in Zenker's solution in the usual method. These were prepared by the paraffin technique, sectioned at 8 nucrons and stained with eosin-hematoxylin. In a single case the time between death and fixation in Zenker's solution was purposely delayed. The blocks were then fixed in the usual manner, followed by the par— affin technique, sectioned at 8 microns, and stained with eosin-hematoxylin. In most cases, after microscopic study of the entire stained section, a representative portion of a block about 4 mm. square was selected. These 4 mm. portions were removed, reembeded in paraffin, and sectioned.in serials at 8 microns thickness, ranging from 60 to 180 sections in number. Some were stained with eosinphematoxylin, others with Mallory's aniline blue. In one case an attempt to isolate organisms that might be present was made by stroking the freshly cut surface of the tissue on petri plates ccmtaining liver infusion agar, and incubating for 48 hours at 37 degrees C. Studies from serial sections were made when practical. Measurements involving the maximum diameters of Malpighian bodies were also made from_serial section. Photoamicrographs'were made by the use of the Leitz "Makam' photo-micrographic camera. Eastman's Wratten M plates and Super—sensitive Panchromatic cut film, with suitable filters were used. HISTOLOGI CAL STUDIES The tissues for these studies were divided into two groups. Group I consisted of tissues from five apparent 1y normal beef animals and were used for the study of normal histological structures. Group II consisted of two normal dairy heifers and a kidney obtained from a calf from the experimental dairy hard. The tissues fran Group II were used in the study of the effect of different kinds of fixa- tion and the effect of delayed fixation on the microscopic structure. Group I Study of Kidneys from Normal Animals History — These animals were raised at the U.S.D.A. Experiment Station at Miles City, Montana. They were re- ceived by the Animal Husbandry Department of Michigan State College at the age of approximately 6-1/2 months, for study in an experimnt on normal gains in weight. Their rat ion consisted of the following mixture: Yellow corn 6 lbs. Either cotton or linseed meal 1 " Corn silage 3.5 " Alfalfa hay 2 " Cotton and linseed meal were alternated in the mixture at two week intervals. The animals were permitted all of the above feeds that they would consume twice daily. They were fasted 24 hours but permitted free access to water before slaugd ter . The animals were between 14 and 15 months of age when killed. They were felled by a blow on the head, and slaugh- tered in the usual manner. The following data were obtained at that time . 882 on": 003.: «.9 “Em; 02. 0.32 So." .3wa no .33 ass. 85 82: 83+ a.» pawns a: .82 33 Hop: :0 ensue fines... e959 on; 35 a.» 33m 9:. edeaeh mnod pen amalgam so summonses new: . 32.32 .seeame gun on; «.n 33 3m ode: adv." so noLeo s 85H :0 use» .395 one 31> 83 Ann 33 $2. each man." 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In some cases there is differentia— tion of the substance when stained with Ifallory's aniline blue, in that the granules take a light red stain, the foamy material blue. Capsular Basement Membrane. The capsular basement membrane varies from 1 to 2 microns in thickness. Glomerular and Capsular Epithelium. The interior of the capsule is lined, and the exterior of the capillary loops is‘ covered with a flat epithelium. The nuclei appear large, oblong, flattened, and highly vesicular. They appear some- what like the nuclei of vegetative fibroblasts. The chromatin is arranged in fine shreds and granules, and the nuclear mem— brane is very delicate. The nuclei of the mural and visceral epithelium cannot be differentiated. The cytoplasm of the visceral epithelium is so scant as to be inconspicuous except near the borders of the nuclei. It is somewlmt mre abundant in the mural epithelium and is seen as a thin sheet covering the space between the nuclei. Glomerular Endothelium. The nuclei of the cells of the endothelium appear somewhat smaller and less vesicular than those of the epithelium, although there is some variation in their size and vesicularity. They usually appear largest and most vesicular in the regions in which they appear most numerous. 0n cross-section through a capillary loop they bulge into the lumen and appear quite round. Their cy- toplasm is very inconspicuous. There is considerable variation in the distribution of the endothelial cells in the glomeruli. Some capillary loops appear to contain very few. Others contain so many that the direction of the capillary can be easily followed without reference to the basement membrane. It is estimated that there are about four or five times as many endothelial as epithelial cells in the average glomerulus. Basement Membranes of the Capillary L00ps. There is apparently considerable variation in the thickness of the basement membranes of the capillary 100ps. When stained with Mallory's aniline blue, some of them appear as thin blue lines. Others appear to be two to three tines as thick. Capillary Loops as a Whole. There are relatively few capillary loops which contain blood. Iiost of them appear somewhat contracted . \ Proximal Convoluted Tubules. Measurements in Microns. L598 Case Number 1419 1655 1613 1617 Outside diameter minimum 42 36 30 26 26 " " maximum 60 72 60 6O 78 " " average 46.5 48.5 43.8 43.8 53 " " average all cases, 47.16 Inside diameter minimum 13 18 15 15 20 " " maximum 36 42 36 24 54 " " average* 26 26.1 23 19.6 31 " " average all cases, 25.2 Variations in number of epithelial nuclei ob— served on cross-section of proximal convoluted tubules. [Minimum.number observed 2 4 4 4 4 [Maximum " " 8 9 8 8 8 IAverage** " " 5.5 6.8 5.8 6.1 6.2 verage number observed in all cases, 6.08 verage* height of epitheliunlOéa 11.3 10.2 12.1 11.2 all cases, 11 I J * Average found by measuring 10 tubules from each case. ** Average found by counting the epithelial niclei in cross sections of 10 tubules from.each case. DistalAConvoluted Tubules. Measur ems ate 1 n Mic rons . Average* height of epithelium.10.l {Case Number 1398 1419 1655 1613 1617 Outside diameter minimum 42 3O 36 39 30 " ' maximum 50 48 50 48 48 " " average* 47.5 39.8 44.4 43 39.8 " " average,all cases, 43.9 Inside diameter minimum. 13 21 20 17 15 fl " maximum. 36 36 30 26 33 " " average* 27.3 28.5 23 22.7 23.4 " " average , all animals, 24.9 variations in the number of epithelial nuclei db- served on cross-section of proximal convoluted tubules _ Minimum.number observed 8 6 7 5 6 .thimum " " 14 ll 13 11 12 Average** " " 10.3 8 10.1 8.6 8.7 Average, all cases, 9.14 8.2 10.7 10 8 " all cases. 9.4 * Average found by measuring 10 tubules from each case. ** Average found by counting the epithelial nuclei in the cross sections of 10 tubules from.each case. Epithelium of the Convoluted Tubules. The epithelium of the proximal convoluted tubules bulges into the lumina over the nuclei, and with its brush border, which is easily seen, gives an irregular granular out line to the inner wall of the tubules. The cytoplasm appears granular and takes a light stain with eosin. The nuclei appear as typica1,rather higher vesicular, epithelial nuclei. The epithelium of the distal convoluted tubules gives a more regular outline to the surface of the lumina. The cytoplasm appears granular, but there is considerable varia- tion in the intensity to which the tubules stain with eosin. The nuclei appear less vesicular with larger chromatin gran- ules than is seen in the proximal convoluted tubules. The chromatin often appears arranged in one, two, three, or nnre masses within the nucleus, there being a relatively clear zone between them and the nuclear manbrane. Content of the Tubules. Both proximal and distal convoluted tubules contain more or less of a granular and foamy material similar to that observed within the capsular space. There is very little of this material observed in the other portions of the nephron. Blood Vessels The nuclei of both the intima and media of the inter- lobular and afferent arteries appear quite vesicular, but there is no indication of abnormal proliferation observed. Interstitial Tissue The interstitial tissue consists of a delicate fibrous reticulum, and scattered connective tissue cells. Lesions The following lesions are recognized he the sections from the five cases: Case 1398. A few interstitial lesions from.200 to 1500 microns in diameter are observed scattered throughout the deeper portions of the cortex. Macrophages predondnate, but lymphocytes are also present in small numbers. There seems to be no involvement of the parenchyma. Case 1419. One interstitial lesion about 1000 microns in diameter, adjacent to the renal capsule. MacrOphages predominate, but a few lymphocytes are also present. There appears to be no involvement of the parenchyma. Case 1655. One area 2000 microns in diameter infiltrated with lymphocytes. There appears to be’ slight thickening of the capsules of the corpuscles involved. One interstitial lesion about 500 microns in diameter adjacent to area cribosa in end of papillae. Lymphocytes predominate,‘but macrOphages and vegetative fibroblasts are also present. A few lesions involving areas up to 200 microns in diameter are observed scattered throughout the cortex. MacrOphages predominate, but lymphocytes are also quite numerous.‘ An occasional adjacent corpuscle appears to have a slightly thickened cap- sule. There is no other apparent involvement of the parmchyma. Case 1613. There are a few interstitial lesions up to 250 microns in diameter, (one reaching 1000 microns Lscattered throughout the cortex. Fibroblasts predominate, but mac— cophages and lymphocytes are quite numerous. There appears to be no involvement of the parenchyma. Case 1617. There are a few interstitial lesions up to 250 microns in diameter scattered throughout the cortex. Fibroblasts usually predominate, although macrophages pre- dominate in one lesion observed. There appears to be no involvement of the parenchyma. Group II Study of the Effect of Variations in Technique on the Microscopic Structures d’ Kidney Tissue Effect of Delayed Fixation on the Microscopic Structure of Kidney Tissue. Case 238. History The kidney for this experiment was obtained from an animal from the experimental dairy herd of Michigan State College. The animal was slaughtered in the usual manner at 9 A.M. Mscopic Examination of Tissue. Three grayish white Foci, 1 to 2 mm. in diamter, are seen in the outer portion of the cortex. There are no other visible alterations. Technique. Two blocks of tissm, each from Opposite sides of the kidney were placed in Zenker's solution at 10:40 A.M. (one hour and forty minutes after death. The kidney was then placed in the ice box. Similar blocks were placed in Zenker's solution at twenty four, forty eight , and seventy two hours after death. After fixation the tissues were prepared by the paraffin technique, sectioned at 8 microns and stained with eosin-hematoxylin. Microscopic Examination. The tissues fixed at one hour and forty minutes after death present an appearance in structure similar to the tissues of Group I, which were fixed at approximately the same time after death. In the tissues fixed at 24, 48, and-72 hours respectively, there is an increasing appearance of cloudy swelling in the deeper parts of the cortex. The region adjacent to the renal capsule is characterized by shrinkage and complete loss of structure. This process includes a layer of ti 3513 which is about 250 microns in thickness, in the block fixed at 24 hours after death, and which reaches a thickness of about 500 microns in the block fixed at 72 hours after death. The cytoplasm takes a deeper stain with eosin as the length of tine between death and fixation increases.The nuclei show an increasing degree of pyknosis with delay in time of fixation. These conditions are very marked in the sections from blocks taken at 72 hours after death. Effect of Fixing with Fomalin followed,by Fixation in Zenker's Solution. Cases A and B. History These were apparently normal heifers. They were slaugitered in the usual manner at about 9 13.1511. August 7, 1934. Their approximate ages were 18 months each. Macroscopic Examination.of Kidneys. There are no gross alterations observed. Technique. A single kidney was used from each animal. Two adjacent blocks of tissue were taken.fxom.each. One block from.each organ was placed in Zanker's solution at 11:00 PM. The remaining two blocks were placed in a 10% solution.of formalin.for 48 hours and were then fixed in zenker's solution in.the usual manner. After fixation in Zenker's solution the blocks were all prepared by the paraffin technique, sectioned at 8 microns and stained in eosin-hematoxylin. Microscopic Examination. The histologic detail appears similar to that observed in the sections of Group I. A few interstitial lesions up to 250 microns in diameter'are observed scattered throughout the cortices of both kidneys. The parenchyma does not appear to be involved in these lesions. There are no other apparent pathologic alterations. There appears to be less foamy and granular material within.the lumina of the convoluted tubules near the renal capsule in the tissues prefixed in formalin, than in those fixed in Zenker's solution alone. In the deeper portions of the organ there is no significant difference however. DISCUSSION OF HISTOLOGICAL FINDINGS “IN KIDNEYS FROM GROUPS I AND II The variation in size of the Malpighian bodies may be due in part to the amount of blood contained in the individual glomeruli. Since all of the animals used in this study were slaughtered for food, they were bled in the manner customary to that procedure. Animals thus bled lose varying amounts of blood. The amount retained in the different tissues no doubt depends upon the efficiency of the circulation during slaughter, the internal pressure of the organs, the rate of coagulation of the blood, and other factors. The distribution of the retained blood in the kidney does not seem to be uniform. Some, glomeruli contain much more blood than others. There appears to be a greater number of endothelial cells in the glomerulus of. the bovine than has been reported in the human by McGregory.(1). This would not seen phenomenal considering the variations in glonerular structure of some of the lower animals (2) (3). The significance of the uneven distribution of the endothelial nuclei in the glomeruli of bovines can not be explained without further study. They might be most numerous in dormant capillaries. The absence of blood in many capillary loops interferes somewhat with the study of their .normal snaps and structure. Their partial collapse no doubt'causes a variation in the apparent thickness of their basement manbranes, and in the distribution of the epithelial and endothelial cells. If the tissues for study of glomerular histology were collected from animals which retained all of their blood upon death, one might see a different picture upon histological exam- ination than has been seen in these. The distribution of the chromatin in many of the nuceli of the distal convoluted tubules is not understood. This condition can not be regarded as evidence of mitosis because of the frequency with which it is observed, the irregular massing of the chromatin, and the absence of other mitotic figures. This condition was not altered by prefixing in formalin. The granular and foamy material observed in the cap- sular spaces and convoluted tubules is confusing became of the fact mat it stains quite similar to cytoplasm and renders the free surfaces of the cells indistinct in outline. Materials of this nature are considered artifacts by Maximow (4). The fact that it was only observed in the most functional parts of the nephron, and not in the collecting tubules tends to substantiate this belief. If some method of fixation and preparation of renal tissues was used which would elim- inate this material, the tissues would be much more satis— factory for histologic study. Prefixing in formalin, a material employed by Bell (5) did not seem to materially alter the condition. The vegetative appearance of the nuclei of the smaller blood vessels can not be explained. The interstitial lesions described compare favorably, except in extent, with those recorded by Smith (6) in his studies on "white spotted kidneys" in calves.His statement , ”The relative infrequency of lesions in older animals - — —" (after 2-1/2 months), does not seem to apply in these cases. Although macroscopic white spots may not be common in such animals, there is no reason to believe that microscopic' lesions of this nature mightnot occur any time during the life of‘the animal. Group III Studies of Kidneys from Cows Affected with Streptococcic Eastitis The G animals of this series were contained in the experimental dairy herd, and.the others were contained in the regular dairy herd of Michigan State College. These animals were all inspected upon slaughter and considered fit for human consumption. Case G l. Histogy Born November 13, 1925. Had 6 parturitions. One calf was aborted dead and.the fetal membranes were retained. The condition was diagnosed as a B. coli infection of the fetus. Fetal membranes were retained at the time of two other parturitions, but there was no apparent illness. Examined.and found affected with streptococcic mastitis in December 1932. There is a history of infection until the time of slaughter, August 29,1933. Microscopic Examination Malpighian Bodies measurements. many'of the bodies have diameters greater than the average measurement for those of Group I, some reaching 240 microns. Basement Membranes of Bowman's Capgules. Most base- ment membranes show considerable thickening, as compared with those of Group I. Glomerular and Capsular Epithelium. There are no apparent alterations of the epithelium. Glomerular Endothelium. There appear to be two or three times the number of endothelial nuclei as compared with the epithelial nuclei. Basement Membranes of the Capillary Loog. Most glomeruli contain some loops, the basement membranes of which appear thickened. Capillary Loops. Almost every glomerulus caitains several loops distended wdth blood. Some are apparently distended but contain no blood cells. Tubules Proximal convoluted tubules. The variations in size, and the appearance of the epithelium, are within the range of those observed in Group I. Distal Convoluted Tubules. Many of the distal con- voluted tubules appear hypertropic, with outside and inside diameters measuring up to 75 and 48 microns respectively. The epithelial nuclei of some tubules are too numerous to count accurately upon cross section. One hyalin cast 30 microns in diameter is observed in a degenerated convoluted tubule. Blood Vessels There are no apparent alterations in the blood vessels. Interstitial Areas and Lesions The interstitial connective tissue shows an increase to about 4 times the amount present in Group I, but there is little evidence of the replacement of tie parenchyma. Scattered throughout the cortex are a few interstitial foci of lymphocytes rarging up to 200 microns in dianeter. There are a few atrophic gloneruli scattered throughout the cortex. It is estimated that they do not exceed 13% of the total numb er . Case G 3 History Born January 1, 1926. Had 6 par- turitions. Affected with streptococcic nestitis from January 1933 until time of slaughter, October 24, 1933. Microscopic Examination Malpighian Bodies Measurements. Many of the bodies have diameters greater than the average measurement for those of Group I. Some have diameters of about 240 microns. Basement Membranes of Bowman's Cppsules. All show considerable thickening, as compared with those of Group I. Glomerular and Capsular Epithelium. There are no apparent alterations of the epithelium. Glomerular Endothelium. As a whole there appear to be about the same number of endothelial nuclei as compared with epithelial nuclei. Some loops however, show about twice as many of the former as of the later. Basement Membranes of the Capillary Loops. Most glom- eruli contain some loops, the basement membranes of which appear thickened. Capillary Loops. Only the loops of the glomeruli which lie within 1500 microns of the renal capsule, contain much blood. The remainder contains very little blood, but about 50% appear more or less distended. Tubules Proximal Convoluted Tubules. The variations in size and appearance of the epithelium are within the range of those observed in Group I. Distal Convoluted Tubules. Some distal convoluted tubules appear hypertrOphic with out side and inside diameters up to 76 and 60 microns respectively. In some the epithelial nuclei are too numerous to count accurately on cross section. There are occasional hyalin casts observed in degen- erated convoluted tubules, and one such cast is observed in a c olle cting tubule . Blood Vessels Complete occlusion of one, and partial occlusion of several afferent arteries, due to proliferation of the cells of the intima is observed. Interstitial Areas and lesions The interstitial connective tissue shows an increase to about 2 to 4 times the amount present in Group I. Scattered throughout the cortex are a few interstitial foci ranging up to 100 microns in diameter, in which lym— phocytes are the predominating cell. It is estimated that about 27-3 of the glomeruli have under-gone atrophy. Case G 4 History. Born December 28, 19%. Bad 5 parturitions. Examined and found affected with streptococ- cic mastitis December 1932. There is a history of infection until the time of slaughter, March 31, 1933. Iii croscppi c Examinat i on Mal pigh ian Bodie s 'ieasurements. Most of the bodies have diameters of between 240 and 250 micrcns. Basement Membranes of Bowman's Capsules. There are m apparent alterations of the basement membranes. Glomerular and Capsular Epithelium. There are no apparent alterations of the glomerular and capsular epithelium. Glomerular Endothe lium. There appear to be about twice the number of endothelial nuclei as compared with the epithelial nuclei. The distribution throughout the glOmp eruli is not even however. Some loops contain apparently few endothelial nuclei, others many. Basement membranes of the Capillary Loops. Although most of the basement membranes appear normal, there is an apparent increase in the thickness of some. Capillary Loops. Relatively few loops contain.blood cells. most of the loops appear moderately dilated however. TUDuhas Proximal Convoluted Tubules. The variations in size and the appearance of the proximal convoluted tubules, are within the range of those in Group I. Many have diameters greater than.the average found in.that group however, having outside and inside diameters of'about 60 and 36 microns respec- tively. Six to ten epithelial nuclei are commonly seen in a cross section of a tubule. The epithelium appears otherwise normal. Distal Convoluted Tubules. Many of the distal convoluted tubules appear hypertrOphic, having outside and inside diam— eters up to 60 and 33 microns respectively. Some contain nuclei too numerous to count accurately on cross section. There is an occasional hyalin cast observed.in the con— voluted and collecting tubules. Blood Vessels The cells of the media of many of the afferent and interlobular arteries appear vegetative in that their nuclei are quite vesicular. There. is no other evidence of prolif- eration however. Interst itial Areas and Lesions. Scattered throughout the cortex are several foci of macrophages having diameters ranging up to 100 microns. There are also several areas showing a local increase in connective ti ssue- No atrophic glomeruli are ob served howe ver . Case G 6. History Born April 16, 1926. Bad 6 par- turitions. Was affected with streptococcic mastitis from May 1933 until time of slaughter, December '7, 1933. Microscopic Examination Malphighian Bodies Measurements. Most of the bodies have diameters which are within the range of those measured in Group I. A very few have diameters as great as 200 microns. Basement liembranes of Bowman's Capsules. Most of the basement membranes show thickness which ranges from slight increase to 4 times that observed in Group I. Glomerular and Capsular Epitle lium. The nuclei of the glomerular epithelium appear somewhat more numerous than has been seen in most cases. There is no other apparent altera— tion. Merular Endothelium. As a whole the nuclei of the endothelium appear about as numerous as those of the epithe- lium. Some few loops however show an increase over that ratio. Basement membranes of the Capillary Loops. Most glom— eruli contain some loops, the basement membranes of which appear somewhat thickened. Capillary Loops. Relatively few loops are dilated because of the presence of blood cells in their lumina.Many appear moderately dilated but contain no blood cells. Tubules Proximal Convoluted Tubules. Many of the proximal convoluted tubules appear hypertrophic with outside and inside diameters up to 84 and 24 microns respectively. Some show as many as 14 nuclei on cross section, but the epithe- lium appears otherwise normal. . Distal Convoluted Tubules. Many of the distal con- voluted tubules appear hypertrophic with outside and inside diameters up to '75 and 50 microns respectively. Some show as many as 22 nuclei on cross section. Blood Vessels The nuclei of both the intima and media of the ar— ferent and interlobular arteries appear vegetative in that they are larger and more vesicular than is usually seen. The lumina of some appear partially, and of others completely obliterated. Interstitial Areas and Lesions The interstitial connective tissue shows an increase to about 4 times the amount present in Group I. Scattered throughout the cortex are several foci of lymphocytes ranging up to 300 microns in diameter. There is one hemorrhagic area about 300 microns in diameter, located 3 mm. from the renal capsule. It is estimated that from .5 to 1% of the glomeruli show marked atrophy. Case G 9 Hi stogy. Born September 3, 1926. Bad 4 par— turitions. Was affected with strept ococcic mastitis from December 1932 until slaughtered, October 18, 1933. Microscopic Examination Malpighian Bodies Measurements. Many of the bodies have diameters greater than the average measurement for those of Group I, some reach— ing 245 microns. Basement Membranes of Bowman's Cagules. The basement membranes of the capsules appear to be from 2 to 4 times as thick as those of Group I. Glomerular and Cppsular Epithelium. There are no appar— ent alterations of the epithelium. Glomerular Endothelium. As a whole the nuclei of the endothelium appear about as numerous as those of the epithe- lium. Some loops however show an increase over that ratio. Basement Membranes of the Capillary Loops. Most glom- eruli contain capillary loops the basement membranes of which appear somewhat thickened. Capillary Loops. Relatively few loops contain blood. Mbst of the loops appear moderately dilated but contain no blood cells. . Tubules Proximal Convolut ed Tubules. Many tubules have out side and inside diameters of 60 to 80 and 24 to 36 microns respec— tively. As many as 12 epithelial nuclei are seen on cross section, but the epithelium appears otherwise normal. Distal Convolut ed Tubules. Many tubules appear hy— pertrophic with out side and inside diameters up to 7'7 and 5'7 microns respectively. In many instances the nuclei are too numerous to count accurately upon cross section. At a distance of about 4 mm. from the renal capsule are seen a few distal convoluted tubules which appear necrotic in that their epithelium is shrunken from their basement mem- branes, me cytoplasm takes a more intense stain with eosin, and the nuclei appear pyknotic. An occasional hyaline cast is seen in a degenerated convoluted tubule. The cytoplasm of the cells of the epithelium of the thick part of the loops of Henle contains many vacuoles,and a few inclusion bodies which take a bile-like stain. Blood Vessels A few interlobular arteries contain an unusually large number of lymphocytes. The adventitia of some show a marked infiltration with the same type of sell. There appears to be no increase in the vesicularity of the cells of the small arterioles. Interstitial Areas and Lesions In some areas there is an apparent increase in the interstitial connective tissue to about 4 times the amount observed in Group I. This condition is not general however, other areas showing little if any increase. Scattered throughout the cortex are a few interstitial foci of infiltrated cells ranging up to 200 microns in diam.- eter. Macrophages predominate in some of these foci. In others lymphocytes predominate. One cyst 250 microns in diameter is observed at the Junction of the cortex and medulla. Less than .5% of the glomeruli show marked atrOphy. Case G 10. History Born October 5, 1926. Had 5 par- turitions. Affected with streptococcic mastitis from December 1932 until time of slaughter, December 11, 1933. Microscopic Examination Malpighian Bodies Measurements. Most of the bodies have diameters which are within the range of those measured in Group I. There is a tendency,however, toward the greater measurements recorded. Relatively few have diameters of 200 microns or over. Those which have diameters as great as 200 microns contain consid— erable blood. ' Basement Membranes of Bowman's Cafiules. There is only slight if any thickening of the capsules as compared with those of Group I. Glomerular and Capsular Epithelium. There are no apparent alterations of the epithelium. - Glomerular Endothelium. In some glomeruli, and in some loops of other g,lomeruli the nuclei of the endothe lium ‘ appear about as numerous as the nuclei of the epithelium. N Most of the glomeruli, however, contain loops in which the endothelial nuclei exceed the epithelial nuclei in number. It is estimated that in some of these loops the ratio between the different types of nuclei is 6 to l or greater. The tufts which contain large numbers of endothelial nuclei do not appear atrophic. Basement Membranes of Capillary LOOps. Most glomeruli seem to contain some loops, the basement'membranes of which appear thickened. Capillary Loops. Relatively few loops contain blood. Those that do not contain blood, appear to be moderately dilated. Tubules Proximal Convoluted Tubules. Many of the proximal con- voluted tubules have out side and inside diameters up to 78 and 38 microns respectively. Some show as many as 15 nuclei in a cross section. The epithelium appears otherwise normal. Distal Convoluted Tubules. [any of the distal convoluted tubules appear hypertrophic, having outside and inside diam. eters up to 87 and 60 microns respectively. As many as 20 nuclei are observed in a cross section of a tubule. Blood Vessels V There are no apparent alterations of the blood vessels. Interstitial Areas and Lesions The interstitial connective tissue shows an increase to about two times the amount observed in Group I. Scattered throughout the cortex are numerous intersti... tial foci of macrophages. The greater number of them consist of only a few cells. Some reach 30 microns in diameter. As many as 6 foci are observed in a single high power field (.25 mm.). It is estimated that less than .59?» of the glomeruli show marked atrophy . Case G 13 Histog. Born January 24, 1928. Had 4 par- turitions. Was affected with streptococcic mastitis from December 1932 until the time of slaughter, January 20, 1934. Microscopic Examination Malpighian Bodies Measurements. The bodies have measurements which are within the range of measurements for those of Group I. Basement Membranes of Bowman's Capsule . Most of the basement membranes have a thickness that ranges from 2 to 4 times as great as those of Group I. Glomerular and mule: Epithelium. There are no appar- ent alterations of the epithelium. Glomerular Endothelium. The nuclei of the endothelium appear to be about as numerous as the nuclei of the epithelium in some glomeruli. In other glomeruli there appear to be about twice as many endothelial nuclei. The distribution of the endothelial nuclei seems to be quite uniform although some glomeruli contain loops in which they are more numerous than they are in others. Basement Membranes of the Capillary Loops. Most of the glomeruli contain loops, the basement membranes of which appear somewhat thickened. Capillary Loops. Relatively few loops contain blood. Most of the loops appear somewhat contracted. Tubules Proximal Convoluted Tubules. Many of the proximal con- voluted tubules have outside and inside diameters which measure about 60 and 36 microns respectively. As many as 10 to 12 nuclei are commonly observed in a cross section of a tubule. The epithelium appears otherwise normal. Distal Convoluted Tubules. Many of the distal convoluted tubules appear hypertrophic with outside and inside diameters measuring up to 66 and 54 microns respectively. As many as 20 nuclei are seen in a cross section of a tubule. The cytoplasm of the epithelial cells of the thick part of Henle's 100ps contains numerous large vacuoles. Blood Vessels A few afferent arteries are observed which show partial or total occulsion of their lumina, apparently due to the proliferation of the cells of their intima and media. Numerous lymphocytes are ob served in the lumina of some of the interlobular arteries and veins. Interstitial Areas and Lesions The interstitial connective tissue shows an increase of from 4 to 6 times the amount observed in Group I. The distribu— tion is quite general, although there are some areas which show somewhat less interstitial connective tissue than others. Scattered throughout the cortex are a few interstitial foci, ranging up to 300 microns in diameter, in which lym— phocytes predominate, but in which macrOphages are also quite numerous. It is estimated that about 558 of the glomeruli show marks d at rophy . Case G 15 History. Born May 22, 1928. Bad 4 parturi- tions. The fetal membranes were retained in one instance. I Following one parturition, the uterus was averted. Recovery was uneventful in both instances. Was affected with strap-- tococcic mastitis from January 1933 until the time of slaughter, January 23, 1934 . Microscopic Examination Malpighian Bodies Many of the bodies range from ZOO to 220 microns in diam- eter. Basement Membranes of Bowman's Capsules. Most of the basement membranes have a thickness that ranges from 2 to 4 times as great as those of Group I. Glomerular and Capsular Epithelium. There are no appar- ent alterations of the epithelium. Glomerular Endothelium. In some loops the nuclei of the endothelium appear to be about as numerous as those of the epithelium. In other loops there appear to be several times as many endothelial nuclei. All glomeruli observed show this uneven distribution of nuclei. It is estimated that as a whole there are 3 to 4 times as many endothelial nuclei as epithelial nuclei. Basement Limbranes of the Capillary Loops. Most glom- eruli containsome loops, the basement membranes of which appear thickened. Capillary Loops. Relatively few loops are filled with blood. Those which are not filled with blood appear mod- erately dilated. Tubules Proximal Convolut ed Tubules. Mamy proximal convoluted tubules have outside and inside diameters of from 60 to 70 and 18 to 35 microns respectively. A few have outside and inside diameters as great as 80 and 42 microns respectively. As many as 15 nuclei are seen in a cross section of a tubule. The epithelium appears otherwise normal. Distal Convoluted Tubules. Many distal convoluted tubules have outside and inside diameters of from 60 to 72 and 35 to 42 microns respectively. As many as 27 nuclei are seen in a cross section of a tubule. In ore section a few of the convoluted tubules which are in that region between 3 and 6 mm. from the renal cortex, are shrunken from the basement membrane and take a more intense stain with eosin than does the surrounding tissue. The nuclei show no evidence of necrosis however. Much granular material which stains like bile, and a few vacuoles are observed in the cytOplasm of the epithelial cells of the thick portion of Henle's loops. Blood Vessels A few of the afferent arteries appear partially or totally occluded. The cells of these vessels do not appear vegetative however. The adventitia of some of the larger vessels show a marked infiltration with lymphocytes. Interstitial Areas and Lesions The interstitial connective tissue shows an increase of about 4 times the amount ob served in Group I. Scattered throughout the cortex are numerous foci of macrophages which range in size from a few cells to lesions 400 microns in diameter. These larger foci are usually asso- ciated with glomeruli which are apparently shrunken and appear to consist of a mess of pyknotic nuclei and collagen. The tubules are also reduced in size and have been replaced somewhat by the infiltrating cells. In some cases the tu- bules contain lymphocytes and polymorphonuclear cells. In some lesions fibroblasts also appear active, and in a few cases the replacement tissue is largely of this type. It is estimated that about 5 or 673 of the glomeruli show some stage of atrophy. Case G 16. History Born December 9, 1928. Bad 3 par— turitions. Was affected with streptococcic mastitis from January 1933 until the date of slaughter, October 4, 1933. At this time the mastitis had become suppurative. Microscopic Examination Malpighian Bodies Measurements. Most of the bodies have diameters which are within the range of those of Group I. Relatively few have diameters as great as 200 microns. Basement Membranes of Bowman's Capsule . Most of the capsules have basement membranes which have a thickness from 3 to 4 times as great as those of Group I. Glomerular and Capsular Epithelium. There are no appar- ent alterations of the epithelium. Glomerular Endothelium. In some loops the nuclei of the endothelium appear to be about as numerous as those of the epithelium. Other lOOps contain so many endothelial nuclei that it is impossible to count them. All glomeruli appear to have more endothelial nuclei in some loops than in others. No complete occlusion of capillaries by their endothelial cells is observed. It is estimated that as a whole the endo thelial nuclei outnumber the epithelial nuclei 2 to 4 times. Basement Manbrares of the Capillary Loops. Most glom— eruli contain some loops, the basement membranes of which appear thickened. Capillary Loops. Relatively few loops contain blood . Most of the loops appear moderately distended however. Tubules Proximal Convoluted Tubules. Many proximal convoluted tubules appear hypertrophic having outside and inside diam- eters up to 80 and 48 microns respectively. As many as 12 nuclei are seen on cross section of a tubule. The epithelium appears otherwise normal. Distal Convoluted Tubules. Many distal convoluted tubules appear hypertrophic having outside and inside diameters of 75 and 48 microns respectively. In the cross sections of some tubules the nuclei are too numerous to count accurately. Blood Vessels The cells of both intima and media of some of the inter- lobular and afferent arteries appear vegetative, in that their nuclei are larger and more vesicular than is commonly seen. Several afferent arteries appear to be partially or totally occluded. Lymphocytes are numerous in some of the vessels. As many as 23 are seen in a cross section of an arciform artery. Interstitial Areas and Lesions The interstitial conrective tissue shows an increase from 3 to 4 times the amount observed in Group I. It's dis.- tribution is not uniform, the greater amount being observed in the region of atrOphic glomeruli . Scattered throughout the cortex are numerous inter- stitial foci ranging up to 300 microns in diameter. In some foci lymphocytes predominate, while in others macrophages are the most numerous. Vegetative fibroblasts are also frequently seen in the lesions. 'It is estimated that about 5 or 6% of the glomeruli show marked atrophy. Case 130. History. Born November 3, 1929. Had 3 par- turitions. Was affected with streptococcic mastitis from September 1933 to the time of slaughter, March 13, 1934. Macroscopic Examination of Kidneys. The right kidney weighs 612 grams, the left 570 grams. There is no gross evidence of scarring. On section, the portion of the cortex over the pyramids varies from 5 to 8 mm. in thickness. Thestria- tions are fairly distinct, but the glomeruli appear to be more distinct. They appear as pin point dot s. The pyramids appear to contain a little more blood than usual. Microscopic Examination. Malpighian Bodies Measurements. Most of the bodies have diameters which are within the limits of those of Group I. There is a tend- ency however, toward the greater measurements recorded. Rel- atively few have diameters of 200 microns or over. Basement Membranes of Bowman's Capsules. Most of the basement membranes have a thickness which ranges from 3 to 4 times as great as those of Group I. Glomerular and Cappular Epithelium. There are no apparent alterations in the epithelium. A Glomular Endothelium. In some loOps the nuclei of the endothelium appear to be about as numerous as those of the epithelium. In other loops there appear to be several times as many endo thelial nuclei. All glomeruli observed show this uneven distribution of nuclei. It is estimated that there are from two to four times as many endothelial as epithelial nuclei. Basement Membrares of the Capillary Loops. Most glom- eruli contain some loops, the basement membranes of which appear thickened. Capillary Loops. In those glomeruli which are with in 3 mm. of the renal capsule, the loops are more or less filled with blood. The other loops appear moderately dilated. new Proximal Convoluted Tubules. Many of the proximal con- voluted tubules have outside and inside diameters of from 60 to 70 and 24 to 36 microns respectively. As many as 15 nuclei are observed in a cross section of a tubule. The epithelium appears otherwise normal. Distal Convoluted Tubules. Approximately 25% of the distal convoluted tubules appear hyper trOphic, having outside and inside diameters up to 108 and 54 microns, respectively. In many instances the nuclei are too numerous to count ac- curately in a cross section of a tubule. There is an occasional cast of cell debris, or hyalin, observed in a degenerated convoluted tubule. Blood Vessels The cells of both the intima and media of the afferent and interlobular arteries appear vegetative in that their nuclei are larger and more vesicular than usual. The appear- ance of some of the cross sections of these arteries suggests partial occlusion, although there are none observed that appear completely occluded. Interstitial Areas and Lesions The interstitial connective tissue shows an increase of about 3 to 4 times the amount observed in Group I. The dis— tribution is quite general except in the region of a few atrophic units where the amount of connective tissue is greatly increased. ' Scattered throughout the cortex are a few interstitial foci, ranging up to 150 microns in diameter, in which mac— rophages predominate, although lymphocytes are quite numerous. It is estimated that 1e ss than 1% of the glomeruli show marked at rcphy. Case 86. History Born September 30, 1929. Had 3 par- turitions. Affected with streptococcic mastitis from February 1933 until slaughtered May 17, 1934. At this time the mastitis was suppurative in nature. Macroscopic Examination of Kidneys The right kidney shows several pin point grayish—white spots on the surface of the cortex. Upon section there is slightly more blood seen in the right, than in the left kidney. The portion of the cortex over the pyramids is about 10 mm. in thickness. The striations are distinct. The left kidney shows one pin point hemorrhagic spot in the medulla. The deeper 3 mm. of cortex is slightly lighter in color than the rest. Microscopic Examination Malpighian Bodies Measurements. Most of the bodies have diameters which are within the range of those of Group I. There is a tend- ency however toward the greater measurements recorded. Rel- atively few have diameters of 200 microns or over, and these contain considerable blood. Basement Membranes of Bowman's Capsules. There is only slight if any thickening of the basement membranes as com-- pared with those of Group I. Glomerular and Capsular Epithelium. There are no appar- ent alterations of the epithelium. Glomular Endothelium. The nuclei of the endothelium appear to be about as numerous as the nuclei of the epithelium in a relatively few glomeruli. In most glomeruli there appear to be 6 to 8 times as many endothelial nuclei. Basement Membranes of the Capillary L00ps. There is not a marked variation in the thickness of the basement membranes of the capillary loops. Capillarproqps. In those glomeruli, which lie within 3 mm. of the renal capsule, the loops are well filled with blood. Deeper in the cortex relatively few loops contain. blood. Those which contain little or no blood appear mod- erately dilated. Tubules Proximal Convoluted Tubules. Many of the proximal con- voluted tubules have outside and inside diameters of from.6O to 70 and 24 to 36 microns respectively. As many as 12 nuclei are observed in a cross section of a tubule. The epi— thelium.appears.otherwise normal. Distal Convoluted Tubules. A.few of the distal con— voluted tubules appear somewhat hypertrophic with outside and inside diameters of 60 to 70 and 45 to 54 microns respectively. The nuclei are too numerous to count accurately in a cross section of some of these tubules. Blood Vessels The cells of both intima and media of many of the ef— ferent and interlobular arteries appear vegetative in that their nuclei are larger and more vesicular than usual. Several afferent arteries appear partially occluded. The adventitia of some of the larger vessels show a marked infiltration