440 Pathogenesis o£ Undulant Fever 



On section the Malpighian bodies are not always visible and the splenic substance is quite 

 pulpy in character. 



Tlie Intestines show a slight superficial injection throughout the entire tract. The mesen- 

 teric blands are not enlarged. The mucosa of the terminal end of the small intestine shows 

 hemorrhagic injection, and some old free blood is foimd in the jejunum. 



The Stomach is distended and contains about 500 cc. of dark bile-stained fluid. The wall 

 is deeply injected, particularly in the cardiac portion. The wall of the duodenum is also 

 injected. The enlargement of the lymphoid follicles in the duodenum is quite marked. 



The Liver weighs 3,030 gm. The surface is smooth throughout. On section the normal mark- 

 ings are not easily distinguished and the surface appears yellowish. The gall bladder is dis- 

 tended with about 100 cc. of rather thin bile. There are numerous enlarged lymph nodes 

 along the common duct. 



Both Adrenal Glands appear on gross examination to be normal. 



The Right Kidney is markedly enlarged and of a soft rubbery consistency; the capsule strips 

 with ease, exposing scattered small abscesses. On section the normal markings are only 

 partially seen and there are numerous small (metastatic) abscesses in the pyramids and a few 

 in the cortex. 



Left Kidney: The left kidney weighs 360 gm., shows just under the capsule a number of 

 small subcapsular and cortical abscesses. Otherwise, it is similar to the right. 



Permission for an examination of the Central Nenous System was unfortunately not 

 granted. 



The significant gross findings therefore were the enlargement and softening of the spleen 

 and liver. The latter organs showed diffuse acute parenchymatous changes. The enlargement 

 of the lymph follicles throughout the duodenum and swelling of the portal lymph nodes was 

 noteworthy. A fresh fibrinous pleurisy on the left and right lung was associated with the red 

 and gray hepatization and multiple-abscess formation in the right lung. Of particular interest 

 Avas the bilateral metastatic descending nephritis. 



Microscopic examination of sections stained according to the method of Wolbach with 

 Giemsa's stain, hematoxylin-eosin, and Sudan III revealed the following significant findings: 



Lungs: The portions of the left lobe lying beneath the pleura covered with partially or- 

 ganized fibrin nets show marked filling of the alveolar capillaries with red cells. Similarly 

 the blood vessels of the bronchioles are affected. Few alveoli are empty. Directly under the 

 pleura the cell linings of the air sacs are desquamated and imbedded in amorphous material. 

 Below this layer the majority of the alveoli are filled either with red cells or with masses of 

 polymorphonuclear leucocytes and some monocytes. Occasionally an air sac contains a net- 

 work of delicate fibrin threads and a few leucocytes, while others reveal clusters of "dust 

 cells." In the bronchioles and bronchi either red cells or amorphous pink-staining detritus 

 without leucocytes cover the normal mucous lining. In the deeper sections large areas of the 

 parenchyma consist of alveoli gorged with red-cell masses or a transudate. A similar picture 

 is presented by the right lobe, although alveoli with polymorphonuclear exudate enclosing 

 pneumococci predominate. Located directly under the pleura or adjacent to it many alveoli 

 form a confluent mass consisting of mononucleated cells with very few polymorphonuclear 

 cells and some nuclear detritus. The remains of the alveolar septa are hyalinized and necrotic. 

 In the center of these areas dense deeply stained clumps of gram-negative coccoid bacteria 

 are present (pi. 2, fig. 3). Morphologically the organisms resemble Brucella. However, in some 

 alveoli clumps of gram-positive diplococci and aggiegates of single cocci embedded in a mesh- 

 work of long gram-positive and gram-negative rods are seen. The exudate surrounding the 

 bacterial masses is relatively small and consists of polymorphonuclear cells which have 

 phagocytized a great many of the cocci. The alveolar sacs surrounding these various types of 

 abscess are engorged with red cells, not infrequently forming a confluent hemorrhagic 

 pneumonic consolidation. There are no cellular reactions in the bronchioles, although pink- 

 staining loosely arranged material is present in the lumen. 



The exact origin of the abscesses induced by the Brucella organism is not definitely dis- 



