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.

Acute mastoiditis in children: a seventeen-year experience in Dallas, Texas.

BACKGROUND: In the preantibiotic era acute mastoiditis was the most common complication of acute otitis media, often resulting in substantial morbidity and mortality. Since 1989 several investigators have documented an increased frequency of acute mastoiditis in children. METHODS: The medical records of all children with a discharge diagnosis of acute mastoiditis, managed at Children's Medical Center, Dallas, TX, from 1983 through 1999 were reviewed. RESULTS: There were 57 cases of acute mastoiditis during the 17-year period of 1983 through 1999 compared with 57 cases in a 25-year period of 1955 through 1979 reported previously at the same institution. The number of cases of acute mastoiditis per 10,000 hospital admissions increased significantly (regression analysis P = 0.003) during the more recent 17 years. From 1993 through 1999 there were 4.5 cases or more per 10,000 admissions each year, whereas from 1983 through 1992, the incidence never exceeded 4.3 cases per 10,000 admissions (P = 0.018). The median age of the patients was 48 months. Twenty-two patients (38.5%) were younger than 24 months; 17 of these were 12 months of age or younger. Twenty-two (38.5%) patients had no history of previous episodes of acute otitis media. Streptococcus pneumoniae was the pathogen most often isolated from the cultures. Complications of mastoiditis occurred in 20 children (35%). CONCLUSIONS: We conclude that acute mastoiditis continues to be a problem in the post antibiotic era. It occurs mainly in young children and can be the first evidence of ear disease.

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.

Electron microscope observations on Onchocerca ochengi and O. fasciata (Nematoda:Filarioidea).

The fine structure of the females and males of Onchocerca ochengi (parasitizing zebu and cattle) and of the females of O. fasciata from camels were described and compared to other filariae of the genus Onchocerca. It was shown that O. ochengi resembles O. volvulus of humans in its degree of development, while being more primitive than O. gibsoni. Besides other similarities O. ochengi attracts inflammatory cells in the way of O. volvulus and these could be a model for chemotherapeutic trials.

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.

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.

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.

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.

Transmission electron microscopic studies on the effects of toltrazuril on Glugea anomala, Moniez, 1887 (Microsporidia) infecting the three-spined stickleback Gasterosteus aculeatus.

A symmetric triazinone, toltrazuril, was tested in vivo against Glugea anomala parasitizing the connective tissue of sticklebacks (Gasterosteus aculeatus). Naturally infected sticklebacks were incubated in toltrazuril-containing water as intermittent therapy (3 x 2 micrograms/ml for 6 h at 3-day intervals or 3 x 2 micrograms/ml for 24 h at 2-day intervals). As seen at the ultrastructural level, the drug caused severe damage to all developmental stages of G. anomala. When treatment was carried out for 6 h, the xenoma wall exhibited a network appearance. The multinucleate meronts showed tapering at one end and were lysed at places; disintegration of the nuclei was also observed. The sporogonial plasmodia were partially fragmented, and the dumbbell-shaped nuclei of the sporoblast mother cells showed damaged spindle fibres and lysis of the chromosomal material and nuclear membranes. The shape of the mature spores was altered as well. When treatment was done for 24 h, the xenoma wall was completely destroyed. The uni- and multinucleate meronts were completely destroyed and lacked their nuclei, and the sporogonial plasmodia were frequently totally fragmented. The development of the sporophorous vesicle stopped in many cases. In the sporoblasts and their mother cells, vacuolization of the cytoplasma and lysis of the nuclei were observed. Destroyed spores with damaged polar tubes and polaroblasts were frequently detected. It seems likely that toltrazuril could be successfully applied against Microsporidia in fish when used as intermittent therapy at low doses and with prolonged exposure.

Ultrastructural study of Sarcocystis fusiformis (Railliet, 1897) infecting the Indian water buffalo (Bubalus bubalis) of Egypt.

Sarcocysts from the muscular layer of the oesophagus of 20 Indian water buffaloes (about 7--10 years old) have been collected in Egypt and studied by means of electron microscopy in Bonn (West Germany). Large and small cysts have been observed. The large type ranged from 7--30 X 3--7 mm, and the small cysts measured 1.3--5.1 X 0.7--2.2 mm. The metrocytes of both types of cysts as well as the merozoites were very similar concerning their shape, size and ultrastructural characteristics. The metrocytes of the large and small cysts were mostly located at the peripheral region of the cysts and multiplied by endodyogeny. They were variable in shape and size. They ranged from 7.6 X 4.8 micrometer to 9.2 X 5.4 micrometer. Most of them exhibited deep invaginations of their pellicle. Their cytoplasm was electron pale and often extremely vacuolated. The merozoites of both types of cysts were elongated with a length ranging from 14.6--17.0 micrometer and showed all characteristic organelles of these cells (conoid, rhoptries, micronemes, subpellicular microtubules etc.) The wall of the large and small cysts showed no distinct morphological differences. The great similarities between the walls of the two types of cysts as well as between the micromorphology of the developmental stages (metrocytes and merozoites) lead to the conclusion that the two types of cysts examined may belong to one species of Sarcocystis.