الفهرس 
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Abstract
Following intracrop injection of Alcpergillus tam-igatas apexes they were germinated on the mucosa impl-anted into them and passed to the submucosal tissue.Since PAS positive septated mycelli were observed implanted into the mucosa in pigeon killed one week post infection. By this means the fungus reached the circulation. The process of germination of the spores in the mucosa of the crop was probably accompanied by toxin production as Certain species of Aspergillus produced exotoxins and endotoxins when grew in the living tissues. This toxin asends the ’intestinal tract and absored in the circul-ation. In some casesfhis toxin may caused necrotic and ulcerative changes in the mucosa of the gizzord.However, the crop is not a predlection site for the fungus typical aspergillus granuloma was developed in this organ in few cases at the end of the seccnd v:eek. In the proventer-caIus metapIasticihyperplastic changes followed by necrotic process which was attributed to the effect of mycotoxin. Mild lymphoid and heterophil cells reaction were observed. However such changeskJeve_observed only
in some cases. At the end of the first week the effect of qycotoxin was pronounced in the dadenum.The dudenal mucosa showed metaplastic and hyperplastic changes which udeve.
followed by necrotic process. Latter on at the end of
the third week) changes in the intestinal mucosa involved the whole length of the intestine. These changes/manif-ested grossly by minute pin head white nodules dist-ributed ail over the whole Length of the intestine.The intestinal wall was thicOed and had a velvety appear-ance or the wall of the intestine ore thin and flabby. Microscopically changes in the intestine at this stage uje.verepresented by metaplasia,hYPerplasia,ViLd diffuse Lymphoid and histocytic proliferation in the core of the villi. This metaplastic and hyperplastic changes were foll- owed by necrotic and desqumative process. The lymphoid of ;negation of the ibtestine undergo byperplastic process expanded and become prominant grossly as white nodules. At the end of the fifth week differentiation of lymphoid cells into plasma cells was observed. PAS positive large macrophage cells were seen within these hyperplastic follicles. At the end of fifth week focal area of caseous
necrosis were observed in villi which was formerly denuded from its epithelium.Maximum degree of alteration was obs-erved in the intestine a1 the end of the fourth week.
As the fungus reached the circulation fungemia and toxiameia were established.The presenoe of PAS positive fragments of fungal mycelli in the heart blood,pulmonary and hepatic blood vessels at the end of the first week was a good evidence of fungemia. This fuhgemia was followed by Localization of the fungus in the air sacs Lung and Liver in order of arrangement. Typical aspergillus gram-uloma was observed in air sacs in 100% of experimental groups. In the Lung typicalqspergillus granuloma was observed in all experimental groups except the fifth and six* groups. In the liver typical Aspergill2s granuloma was observed in the first, third and fo,;rth experimental groups. Typical aspergillus granuloma developed as a reaction to the presence of the fungus. PAS studies revealed PAS positive sept.ated branched fungal mycelli in the necrotic center. Fragments of such mycelli were also seen in the cytoplasm of the giant cells, Other
changes in the lung and liver as circulatory disturbances, alterative and necrotic changes were due to the mycotic toxins.Lymphoid proliferation in the portal tract of the Liver, Inter and intralelbular lymphoid cell pro/ifration in the lung together with hyperplasia of the peri bron-chial lymphoid tissue were considered as a remote immune response against igspergillus fumigatus infections. and alpha-2 globulin, beta—L and beta-2 globulin and gamma globulin.
Changes in the ki ney consists of focal areas of interstitial nephritis.They began to appear from the first week till the end of the experiment. They were observed in all experimental. groups. The main reacting cells were Hyperprobeinemia was observed in all infected pegions. lis hypexProteinemia was due to increase in globulin fractions.Since albumin concentration was significantlyCkcAZ 514,40decreased in all infected pigeons.This hypoalbuminemia was due to hepatic and intestinal damage. During the first two weeks of infection there was c significant/increase of alpha—I globulin, with the appearance of alpha-2 globulin which was completely, ab5e0 in the control pigeons.Anti-bodies against the fungus wi.;:s suggested to be present in alpha globulin fraction in the early stages of the disea-se. El—Batrowi(1980) used counter eiectrophoresis and found precipitins in the sera of Aspergillus fumigatus infected chikcens, from 10 days post infection.The elevation. was attributed to continuous reinfection from gener-alization.
from our results we can concluds that intra crop
injection of Lspergillus fumigatus in pigeons caused a
L.AIS generalized form of the disease. The fungus/localized
in the air sacs, lung and liver. An immune response to the fungus Was observed in the intestine liver, Lung and kidney.
All infected pegions showed hyperproteinemia. Elev-ation of total serum: protein concentration was due to increased globulin concentration Since albumin was sign-ificantly decrease in all infected groups. At an early stages of infection alpha globulin concentration was increased. A delayed response of gamma globulin was observed. IVaximum concentration of gamma globulin was observed at the end of fifth week. However alpha globulin at a latter stages remair/at a relatively high level.