Infection with Plasmodium chabaudi diminishes plasma immune complexes and ameliorates the histopathological alterations in different organs of female BWF1 lupus mice.

OBJECTIVE: To determine the effect of Plasmodium chabaudi infection on the plasma level of circulating immune complexes (CICs), haemoglobin (Hb) content, urine profile, and histological features of female BWF1 mice, the murine model of systemic lupus erythematosus (SLE). MATERIALS AND METHODS: A total of 30 female BWF1 lupus mice were randomly divided into three groups as follows: group (I) control group (P. chabaudi uninfected); group (II) lupus mice infected with live P. chabaudi; group (III) lupus mice infected with irradiated P. chabaudi. Urine samples were daily collected from the second week-post infection. Mice from the three groups were killed at day 14 post-infection and heparinized blood was collected for further haemoglobin contents and plasma analysis. Paraffin-embedded kidney, liver, lung, heart, brain, ovary and skin tissues were stained with Hematoxylin and Eosin (H&E) and examined under light microscope. RESULTS: Our results reveal that infection of lupus mice with live P. chabaudi was associated with an increase in urinary Hb and a decrease in plasma Hb and CIC levels. Interestingly, infection of lupus mice with live P. chabaudi ameliorates the histopathological alterations mediated by lupus disease in kidney tissues. Although no parasite sequestration was observed in any of the investigated organs, P. chabaudi pigment deposition was observed in the liver of both live and irradiated P. chabaudi infected groups. CONCLUSIONS: This study in lupus prone BWF1 mice indicated that gamma-irradiated P. chabaudi infection has the desired lupus ameliorating effect without negative effects of malaria which assist the understanding of different responses to plasmodium sp. infection in human lupus patients.

Enzymes of delta 1-pyrroline-5-carboxylate metabolism in the camel tick Hyalomma dromedarii during embryogenesis. Purification and characterization of delta 1-pyrroline-5-carboxylate dehydrogenases.

The activity of P5C metabolizing enzymes: OAT, P5CR, PO, and P5CD, in the camel tick Hyalomma dromedarii has been followed throughout embryogenesis. The profiles of enzymatic activity showed clear differences in the four enzymes as the embryos grew older. During purification of P5CD to homogeneity the ion exchange chromatography steps lead to two separate forms (termed A and B) with different molecular weights (60,000-59,000 and 50,000-52,000 for the native and denatured enzymes, respectively), amino acid composition, Km for P5C and coenzymes, varying dehydrogenase activities with different substrate specificity when supplied with various aldehyde substrates. Both P5CD A and B exhibited sharp optima at pH 7.5. The effect of different divalent cations and competitive and noncompetitive inhibitors was examined. The changes in P5C metabolizing enzymes during embryogenesis suggest that H. dromedarii has the metabolic potential to convert ornithine into proline and glutamate.

Electron microscopic study on macrogametogenesis of Eimeria labbeana infecting the Egyptian wild doves and host-parasite relationship.

The development of macrogametes of Eimeria labbeana was studied by electron microscopy in the epithelial cells of the villi at 96 hrs. post-infection. Appearance of young macrogamonts was characterized by the loss of the architecture of the apicomplexa (polar ring, rhoptries, micronemes, conoid, subpellicular microtubules), while the pellicle became only one unit membrane. This was associated by the formation of wall forming bodies II then I. Moreover, the mitochondria, endoplasmic reticulum and Golgi were increased in the cytoplasm. Amylopectin granules as well as lipid globules were greatly increased in mature macrogametes. Host cell reaction due to infection included enlargement and deformation of infected cells, hypertrophy of their nuclei, swollen and degeneration of mitochondria, endoplasmic reticulum and vacuolation of ground cytoplasm. These changes occur in both cells with and without parasite.

Endodyogony and cyst formation of Sarcocystis gongyli (Trinci 1911) from the skink Chalcides ocellatus.

The heteroxenous life cycle of S. gongyli comprising both the skink Chalcides ocellatus (intermediate host) and the snake Spalerosophis diadema, herewith the process of cyst formation was followed by means of light and electron microscopy after experimental infection. Following migration of the merozoites to muscle fibres, they changed into globular metrocytes, meanwhile a parasitophorous vacuole enclosing them. As development proceeded the wall of the parasitophorous vacuole is thickened in the form of striated protrusions as well as the metrocytes underwent endodyogony producing large numbers of banana-shaped merozoites in the centre of the cyst. Mature microscopic sarcocyst appeared at 120 days p.i, and these were characterized by presence of stalky leaf-like protrusions in their primary cyst wall. Asexual multiplication of metrocytes occurred through endodyogony in which always the mother metrocyte produced two opposite merozoites.

Life cycle of Hepatozoon mehlhorni sp. nov. in the viper Echis carinatus and the mosquito Culex pipiens.

Hepatozoon mehlhori sp. nov. and its developmental stages from the tissues of the Egyptian viper Echis carinatus and the mosquito Culex pipiens are described. The erythrocytic parasites were differentiated into the small form (trophozoite) measuring 14.5 +/- 0.6 x 4 +/- 0.12 micron and the mature form (gametocyte) measuring 17.2 +/- 1.6 x 5.4 +/- 0.5 micron. Merogony took place in the pulmonary endothelial cells and in the parenchyma cells of the liver and spleen of the infected vipers. Two types of meront were found. The large meronts (macromeronts) were 30.2 +/- 1.73 x 22.6 +/- 1.2 microns in size and yielded 16-40 (average, 28) micromerozoites measuring 17.2 +/- 0.7 x 5 +/- 0.15 microns. The small meronts (micromeronts) measured 18.2 +/- 0.6 x 13.5 +/- 0.5 microns and yielded 2-14 (average, 8) macromerozoites that were 15.1 +/- 0.12 x 6.2 +/- 0.8 microns in size. After syzygy in the haemocoel of the mosquito, the microgamont produced four uniflagellate microgametes (6.4 +/- 0.3 x 4.5 +/- 0.5 microns in size, with a short flagellum measuring 3.2 +/- 0.1 microns); on the 3rd day post-infection (p.i.)., one of these fertilized the macrogamete, giving rise to the zygote. The oocyst developed from the zygote on the 5th day p.i. and measured 135 +/- 2.6 x 120 +/- 1.8 microns. About 11-60 (average, 35) sporoblasts were formed by centripetal invaginations from each oocyst on the 8th day p.i. and developed into sporocysts on the 14th day p.i. Inside each sporocyst, 5-12 (average, 8) sporozoites, each measuring 12.6 +/- 1.2 x 4.1 +/- 0.3 microns, developed on the 16th day p.i. According to the above-mentioned characteristics the parasite was recorded as being a new species and was named Hepatozoon mehlhorni. Experimental transmission was accomplished by i.p. inoculation of the infectious stages (sporozoites) into uninfected vipers and led to the appearance of blood stages at 4-6 weeks p.i.

Biological control studies of soft and hard ticks in Egypt. I. The effect of Bacillus thuringiensis varieties on soft and hard ticks (ixodidae).

The potential activity of three varieties of Bacillus thuringiensis (kurstaki, israeliensis, and thuringiensis) against the soft tick Argas persicus and the hard tick Hyalomma dromedarii was investigated. Soft ticks succumbed within a period ranging from 36 h to 5 days and hard ticks died at between 48 h and 10 days posttreatment, depending on the dose. Concentrations lethal to 50% of tick populations (LC50 values) indicated that Dipel 2x (B. thuringiensis var. kurstaki) was the most potent, followed by Vectobac (B. thuringiensis var. israeliensis), then HD 703 (B. thuringiensis var. thuringiensis). A. persicus was more affected than H. dromedarii by B: thuringiensis varieties. Eggs were mostly affected at 16 and 25 days after deposition for A. persicus and H. dromedarii, respectively.