Abnormal heterophils 



The only cell defect recognized thus far is the 

 fractured nuclei such as shown in figure 3, 1. 

 In this case, 2 of the 3 lobes showed a nonstaining 

 band. It is apparent that the same type of nu- 

 clear chromophobia occurring in the erythro- 

 cytes, lymphocytes, and other cells can also oc- 

 cur in heterophils. The possibility that these 

 fracture lines and empty nuclei represent path- 

 ologic conditions, rather than technic defects, 

 has been discussed (pp. 32 and 65). 



Undoubtedly other abnormal heterophils exist 

 in birds as they do in mammals but up to this time 

 sufficient knowledge of the normal by which 

 identification of the abnormal can be made is 

 lacking. Toxic granules in human neutrophils 

 are considered abnormal and play an important 

 role in prognosis. Osgood and Ashworth ( 1937) 

 note three points of difference from normal 

 cells — color of cytoplasm, presence of vacuoles, 

 and coarse granulation. Osgood goes on to say 

 (p. 51), "The author predicted death of more 

 than 100 consecutive patients from a three or four 

 plus change in two of these factors. Ninety per- 

 cent of these died within a week after the pre- 

 diction was made. These patients died of a wide 

 variety of conditions, including malignant tumors 

 and leukemias as well as infections." In view 

 of its value in human hematology, it would seem 

 desirable to further study avian blood in search 

 of this mammalian counterpart. Thus far, how- 

 ever, nothing has been observed that could be 

 identified in avian blood as toxic granules. Per- 

 haps this is because most of these studies have 

 been on birds that showed no obvious disease. 



Technic artifacts (fig. 174) 



The effect of water on the rods was emphasized 

 by soaking the slide for 20 minutes after methyl 

 alcohol fixation and before staining in May- 

 Griinwald Giemsa. The result of such treatment 

 is shown in figure 174. All trace of rods has 

 disappeared; instead there is a cytoplasmic net- 

 work with a granule in the center of each space. 

 The technic used in figures 154-165 was Wright's 

 stain but it was applied by the bulk method (p. 

 229) instead of to individual slides on a rack. 

 Since the bulk method requires somewhat longer 

 staining and slower drying, it involves longer ex- 



posure to aqueous solutions. Hence one finds 

 in this series of slides more examples in which 

 rods have disappeared than one usually finds in 

 normal birds by using the staining rack technic. 

 No technical method has yet been found that will 

 hold the rods well enough to insure confidence 

 that the appearance of the heterophil is really 

 due to the jjird and not to technic. Such a 

 method is urgently needed. Even the Petrunke- 

 vitcli fixed smears show dissolution of the rods 

 (fig. 203) and in this case neither rods nor gran- 

 ules were visible. Petrunkevitch No. 2 (p. 230) 

 is an alcoholic solution with copper, ether, and 

 other sujjstances, and it would not be expected to 

 act like an aqueous fixative. Bradley (1937), 

 quoted on p. 88, observed that adequate fixation 

 would not hold the rods if followed by aqueous 

 stains. 



In view of the high lability of the rods, it seems 

 appropriate to raise the question. How faith- 

 fully has the heterophil rod been preserved in 

 tissue section? If rods disappear but granules 

 remain, a heterophil can look like an eosinophil. 

 Thus, the descriptions of tissue infiltration or of 

 myelopoiesis as worked out on tissue sections 

 may be open to question until it has been demon- 

 strated that the technics used do not destroy the 

 rods. Dantschakofl^ (1909a and b) in her study 

 on the bone marrow of birds follows the processes 

 of myelopoiesis through the stages showing rods, 

 and her beautiful colored plates show them well 

 preserved. Our sections of hematopoietic em- 

 bryo tissues failed to show these rods. 



Much that is seen in the dried smear from cir- 

 culating blood may be artifact; yet the opinion is 

 maintained that bird differences are in part re- 

 sponsible for some of the deviations from the 

 typical. Although all slides are handled alike 

 in bulk staining, some birds show rods and in 

 others hardly a rod can be found. It would go 

 far toward solving some of these problems if 

 fresh blood preparations were carefully studied 

 under the phase microscope. The variabilitv 

 due to technic and that due to bird differences 

 could be separated. Additional evidence that 

 rods of heterophils can come to look like granules 

 of true eosinophils in vivo is indicated in the ex- 

 amination of smears from blood spots of eggs. 

 Here every heterophil simulated an eosinophil 

 (Lucas, 1946) . Natt and Herrick (1954) have 

 reaffirmed what others have demonstrated, that 

 loss of rod substance leaves a central granule 



87 



