الفهرس 
AcknowledgementOnly 14 pages are availabe for public view
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Abstract
Trichinosis constitutes one of the most important zoonotic problems in the world specially in temperate zones. The parasite, T. spiralis, can spread easily among pork eatrers through predation and consumption carrion. Its occurrence in man mainly depends on the dietary habits of the population especially the consumption of raw or inadequately cooked pork or use its flesh or fat in adulterating processed beef meat being so much cheaper. T. spiralis causes transient infection of vrious organs including heart, brain and liver but primary district in skeletal muscle. The migration and invasion of larvae and their encystation in skeletal muscle provoke several local pathological changes in these organs. The aim of the present study is:- 1. To study the possible changes in the activity of the lysosomal enzymes i.e., ?-glucuronidase, ?-naphthyl acetate esterase and acid ribonuclease in skeletal muscles, liver, spleen and brain in mice experimentally infected with T. spiralis. 2. To study the associated histopathological changes in the associated studied organs. 3. To study the effect of the injected crude larval antigen prior to infection on the activity of the lysosomal enzymes and the associated histopathological and haemoatological changes. 4. To study the incidence of infection with T. spiralis larvae in ready to eat meat products collected from local markets in Alexandria. The present work was carried out on 300 male Swiss albino mice of two months old, weighing from 20 to 25 grams were used for the implementation of the present study and categorized into the following groups: Group I : Includes 50 uninfected animals to represent the control group. Group II: Includes 50 mice experimentally infected with 200 T. spiralis larvae per os. Group III: Includes 50 mice were only immunized mice with a single dose of crude larval antigen emulsified with an equal volume of Freud’s incomplete adjuvant (250 ?g total protein). To represent a control group to group IV. Group IV: Includes 50 mice were used. Each one was injected with subcutaneous (S/C) single dose of crude larval antigen emulsified with an equal volume of Freud’s incomplete adjuvant two weeks prior to infection with 200 T. spiralis larva per os. Group V: Includes 50 mice were only immunized with two doses crude larval antigen emulsified with an equal volume of Freud’s incomplete adjuvant to represent a control group to group VI. Group VI: Includes 50 mice used. Each one was given two successive doses of S/C with crude larval antigen emulsified with an equal volume of Freud’s incomplete adjuvant, within 10 days interval prior to infection with 200 T. spiralis larva per os. For the implementation of the present work , ten mice from each group were sacrificed at the 2nd, 4th and 8th weeks post infection, for performing biochemical, histopthological and haematological studies. Each mouse was infected orally with 200 muscle larvae per OS. The strain of T. spiralis was obtained from infected pigs’ meat from the main slaughter house in Alexandria. Larvae were collected by acid pepsin digestion method. Crude larval antigen was prepared and used in the study. The results of the present work showed that: 1. Results of the activities of the lysosomal enzymes: a. The activity of the lysosomal enzymes, i.e., ?-glucuronidase, ?-naphthul acetate esterase and acid ribonuclease were significantly increased in the group 2 when compared with the control group throughout the whole follow up study periods. b. All enzymes activities level in group 4 were slightly decreased, while a significant decrease in group 6 was observed, when compared with group 2 but still statistically higher compared to the control level. This effect in group 6 was more pronouced at the end of the study. These changes could be attributed to the increased fragility and rupture of lysosomal cells of the infected group leading to the leakage of these lysosomal enzymes. It could be also due to the excessive damage of muscle fibers by encysted larvae. In addition to the progression effect of T. spiralis infection and their toxic products. 2. Results of the histopathological study: a. The obtained results demonstrated that the highest muscular invasion by T. spiralis larvae was occurred at the end of the 4th and 8th W.P.I in group 2. The pathologic injuries of skeletal muscle by T. spiralis were through the transformation of normal skeletal muscle into modified one; marked collagenosis and calcification as confirmed ultrastructurally by electron microscope. b. Hepatocytic injury started earlier (2 W.P.I.) than muscular affection mostly due to the release of cytokines biproducts and antigen antibodies complexes during the intestinal phase of T. spiralis. Liver injury starts by mild reaction with normal hepatocytic lobules at the 2nd W.P.I, then inflammatory hepatic injury augmented at 4th and 8th W.P.I forming bridging and lobular necrosis. c. Eosinophilis were the main inflammatory cells in trichinosis in both muscles and liver confirmed ultrastructurally, hence, blood eosinophilia is an early investigatory tool to expect trichinosis at its intestinal phase. d. T. spiralis larval antigen minimize the pathological effect of T. spiralis in both liver and skeletal muscle throughout the experimental study. 3. Results of haematological study: a. A significant leucopenia in groups 2 and 4 was recorded at the end of the 8th W.P.I, which could be attributed to the toxins released from the worms. On the other hand a significant leucocytosis was reported in group 6 at the end of the 8th W.P.I which could be due to the injected foreign protein (larval antigen). b. An initial significant decreased in lymphocytic count in groups 2, 4 and 6 at the end of the 2nd W.P.I., then followed by a significant increase in the lymphocytic count among the previously mentioned studied groups at the end of the 4th and 8th W.P.I. These changes could be due to marked stimulation of the thymus in T. spiralis infected mice resulted in lymphocytic proliferation and lymphokine production confirmed the specific cell mediated responses. c. A significant increase in the eosinophilic count in groups 2, 4 and 6 at the end of the 2nd and 4th W.P.I was noticed. This could be attributed to the stimulation of the bone marrow by foreign protein arising from larvae during their migration; invasion of tissues and encystment development in striated muscles. d. An initial increase in the neutrophilic count in groups 2, 4 and 6 at the end of the 2nd W.P.I. was recorded. This increament could be due to normal reaction to the infection by T. spiralis. However, at the end of the 4th and 8th W.P.I a significant decreased level of nutrophils was recorded. This reduction could be explained on the basis that most of the neutrophils were attracted to the site of larval infection or due to the relative increased of eosinophilc cells. e. Calculation of the blood indices revealed the presence of hypochromic macrocytic type of anaemia. The development of this type of anaemia could be attributed to the intestinal worm infection which interfere with the absorption of vitamine B12 and/or Folic acid. Or due to the gastrointestinal disturbance commonly associated with T. spiralis infection which represent itself in the form of a prolonged and rather severe diarrhea characterized by non-bloody non-mucoid stools. These pathological changes of the gastrointestinal tract might lead to the interference with the absorption and utilization of the digested food especially iron and proteins. Besides the splint haemorrhages beneath the nails which commonly induced by this type of nematode infection aggrevate the condition of anaemia. 4. Results of the examined samples of ready to eat meat products collected from local markets in Alexandria: The finding of the present work confirmed the absence of pork meat and lard from all the screened samples using ELISA technique. In addition no larvae were detected in the meat or meat products by using digestion technique. On the grounds of the present study, it can be concluded that: 1. The infection of swine with T. spiralis constitutes a public health hazard as they are considered to be a potential source of infetion with trichinosis in human. Controls for T. spiralis infection emphasis must be placed on: public awareness, detection and destruction of infective larvae. 2. The recorded changes activities in the lysosomal enzymes of the present study may play an important role in the pathogenesis of T. spiralis infection. Thus the detection of these enzymes in blood of suspected patients infected with T. spiralis should be stressed upon for the diagnosis. 3. Further studies should be carried out using repeated doses of immunized antigen to clarify its role as a vaccine using for the protection against trichinosis. 4. The precise causes in the development of macrocytic hypochromic anemia needs further investigators.^leng