Studies on three species of the genus Cystocephalus Schneider, 1886 (Apicomplexa: Eugregarinida: Stylocephalidae) with special reference to host specificity and distribution of members of family Stylocephalidae in Egypt.

Three species belonging to genus Cystocephalus, Schneider 1886 were found parasitizing three coleoptra hosts. Out of 105 Blaps polychresta, only one male was infected with C. algerianus and females were parasites free. Ten percent of examined Pimelia angulata Ten percent of examined Pimelia angulata (n = 30) were infected with the same parasite. Among are one male (5.56%) and 2 females (16.67%). Out of 126 of Trachyderma hispida 6 (4.76%) were parasitized by C. gabei. Only 3 males (5.1%) and 3 females (4.48%) were harbouring this parasite. Cystocephalus albrechti were found infecting 78 (61.9%) out of 126 of T. hispida. Forty six males (77.93%) and 32 females (47.76%) were infected. Males of the three tenebrionid hosts were more susceptible to infection rather than females. B. polychresta was considered a new host for C. algerianus in Egypt. Also, C. albrechti might be considered as specific host for T. hispida. Mid and hind gut appeared blackened in case of massive infection (> 240 parasites per host) of parasitized males of C. albrechti. The host specificity and the first biogeographical map fort distribution of stylocephalids and cystocephalids are provided here.

Biological studies on the snail intermediate hosts of schistosomiasis with a special emphasis on using larval echinostomes as biocontrol agent against larval schistosomes and snails.

The present investigation deals with the infectivity of the two snail intermediate hosts of schistosomiasis, Biomphalaria alexandrina and Bulinus truncatus collected from nine drains in Sharkia Governorate, Egypt. The rate of infection among the snails was general low being 0% in many drains. Regarding B. alexandrina, the rate of infection ranged from 4-16%, and in B. truncatus ranged from 4-8%. Infection with larval echinostomes was dominant over larval schistosomes in the two snail vectors. The distribution of larval schistosomes was restricted to the hepatopancreas of the two snail vectors, while larval echinostomes were distributed in head, foot, kidney, haemocoelic cavity, hepatopancreas...etc. The predation of larval schistosomes by larval echinostomes and the severe histopathological effects induced by larval ecbinostomes strongly enhances using them as biocontrol agent. The physico-chemical parameters and pollution condition in the drains seem to have no effect on the process of snails infectivity. It is concluded that larval echinostomes can resist the polluting conditions in the drain. The two snail vectors exhibit very minimal or rare host response against larval echinostomes. Probably, the toxicants and pollutants in the drain may act as stressor that makes the snails much more susceptible to infection by larval trematodes.

Sotos syndrome (cerebral gigantism): a clinical and radiological study of 14 cases from Saudi Arabia.

Fourteen children (of Arab ethnic origin) with Sotos syndrome are described. They were referred to King Khalid University Hospital, Riyadh between July 1992 and June 1997. Their phenotypic characteristics were compared with established diagnostic criteria. There was a male:female ratio of 1.3:1 and a high rate of consanguinity (36%) among parents. At birth, 54% were large and about one-third showed increased height and occipitofrontal head circumference (OFHC). The neonatal histories revealed respiratory and feeding problems in 21%, followed later by delayed motor milestones and speech development in 57%. During childhood, weight, height and OFHC increased further to > 97th centile in 71%, 71% and 93%, respectively. A seizure disorder affected 43%, and 75% had mental retardation (IQ < 70). A non-specific EEG abnormality was found in half of those with seizures. Cranial CT/MRI showed ventricular dilatation in 15% and one patient had corpus callosum dysgenesis. Abdominal ultrasound revealed hydronephrosis in two patients. Radiological cephalometric measurements showed relative prognathism in cases of Sotos syndrome compared with controls (p = 0.003). The study highlights the importance of considering Sotos syndrome in children who present with psychomotor delay.

Spatial shifts of the conjugate beam generated by a nondegenerate photorefractive phase-conjugate mirror.

We demonstrate that the phase conjugation of a beam during nondegenerate four-wave mixing is accompanied by a spatial shift relative to the degenerate conjugate-beam location. Experiments with a photorefractive phase-conjugate mirror reveal that the phase-conjugate beam shifts have a nonmonotonic dependence on the probe's detuning frequency and comprise both lateral displacements of up to 218 mum and angular tilts of up to 34 arc sec. An approximate theory based on spatial dispersion coefficients is in partial agreement with the experimental results.

Pairing of Schistosoma mansoni males in infected Syrian hamsters.

Pairing of male schistosomes in the liver of infected hamsters was recorded with Egyptians S. mansoni strain. The homospecific male pairs never carried each other in the gynaecophoric duct, but they being closed in either central or hepatic veins. Other perfused males and females en copula showed normal mating behaviour. The paired males were more or less in the same size. The random sexed miracidia used resulted in obtaining 1:2.1 female/male ratio. It is concluded that the random increase of male schistosomes may create the male pairing behaviour. Also, the migration of female against the blood stream to the mesenteric plexus of the host and the failure of male to catch them may lead to this homosexual pairing. The black haemozoin-like substance seen in mature females was also observed in the pairing males and this probably reflects the effect of scarcity or migration of females to the mesenteric plexus.

Laparoscopic cholecystectomy and the umbilicus.

BACKGROUND: Pre-existing umbilical defects may present technical problems in patients having laparoscopic surgery. Fascial defects may also occur after operation. Understanding the causes and mechanisms of herniation at laparoscopic port sites may help avoid potentially serious postoperative complications. METHODS: The incidence, management and potential complications of pre-existing and postoperative umbilical defects were studied in 870 patients undergoing laparoscopic cholecystectomy. RESULTS: The incidence of umbilical or paraumbilical defects was 12 per cent. The hernias were symptomatic in only 16.3 per cent; the majority of patients were unaware of the defect. The umbilical port was established through, or directly adjacent to, the defect, allowing simple anatomical repair in 90 per cent, using absorbable sutures. The recurrence rate was 3.8 per cent; recurrence was usually caused by wound extension or infection. Incisional hernia occurred in 16 patients after cholecystectomy (1.8 per cent). Only one hernia developed at a port site other than the umbilicus. Risk factors associated with incisional hernia were wound extension in 12 patients, male sex in six, wound infection in five, diabetes in four, pre-existing umbilical hernia in four and acute cholecystitis in three. CONCLUSION: The significant incidence of umbilical defects in patients undergoing laparoscopic surgery calls for accurate diagnosis and good technique. The incidence of incisional hernia might be reduced by avoiding unnecessary wound extension and the use of non-absorbable sutures for defects larger than 2 cm and in men with umbilical hernia.

Modes of resonators with dispersive phase-conjugate mirrors.

We investigate the transverse and longitudinal modes of a resonator consisting of a spherical mirror, a Gaussian aperture, and a dispersive phase-conjugate mirror (PCM). The photorefractive PCM introduces spatial dispersion in the form of lateral and focal shifts along with temporal dispersion. For both degenerate and nondegenerate operation, the decentered Gaussian beam was found to be a mode whose peak intensity is displaced from the resonator axis. In the nondegenerate case, the components of a mode oscillating at a pair of frequencies that are up and down shifted from the pump frequency by the same amount have different spatial distributions, so that the intensity pattern moves periodically across the output mirror. The resonance frequencies of the longitudinal modes are calculated numerically.

Axenic in vitro culture of Schistosoma mansoni miracidia.

Miracidia of Schistosoma mansoni have been grown axenically. The use of saline solution of 0.75% facilitated the shedding of epidermal plates which if occurred promote a rapid sporocystogenesis. Also, the use of a ratio of 1:3 (fetal calf serum and medium 199) in addition to chernin balanced salt solution (SBSS) was ideal for maintaining sporocysts up to 14 days. All the miracidia sheded their epidermal plates 2 hours post cultivation. At the end of the second week post cultivation, the daughter sporocysts measured 690u in length by 50u in width. The usage of plastic flat sided flasks with plenty of culture medium was very important for induction a proper growth of sporocysts because it was possible that adherence of sporocysts to each other might delay their growth.

Studies on the sacculant portion of the kidney of Biomphalaria glabrata Say (1818) as a haemopoietic organ.

The term immunity signifies all those properties of the host which confer resistance to a specific infectious agent. This resistance may be of all degrees ranging from complete to incomplete susceptibility. The defensive functions is performed by various cellular and humoral components which interact with each other producing a co-ordinated immune response directed towards eliminating the pathogen or minimizing its danger. Snails as other members of the Animal Kingdom have their own immune system. The present study concentrated on the sacculant portion of the kidney of B. glabrata as a haemopoietic stem cell. The histological picture of this portion in the kidney as well as in-vitro culture was studied. (I) The histological studies showed that (a) the sacculant portion constituted the last fifth of the kidney highly folded with primitive epithelial tissue, (b) amoebocytes (10.7 +/- 0.98m) rounded, oval or amoeboid, showing flattening and spreading when encapsulated around foreign particles, when doing so, both the cytoplasm and nucleus were more basophilic, (c) the haemocytes in the sacculant portion were distributed either as clustering forming amoebocytic plugs or dense aggregation or being normal in distribution (d) there was a significant correlation between haemocytic diameter and shell weight and between shell weight and shell diameter but no significant correlation between haemocytic diameter and shell diameter. (II) The in-vitro studies showed that (a) The medium 199 and fetal calf serum (3:1) produced higher number of granulocytes, (b) the cells differed in shape and size from those shown in histological studies of the kidney itself (c) the majority of the cells were large sized granulocytes and very few small sized hyalinocytes, (d) granulation of cytoplasm took place in the culture medium used more than in the sacculant portion, (e) only the smaller granulocytes showed greater ability for mitotic division. The results were photographed and discussed.

Effect of the behavioural stress on susceptibility of Syrian hamsters to Schistosoma mansoni infection: effect on number and fertility of worm burden.

Effect of pairing on susceptibility of male Syrian hamsters to Schistosoma mansoni infection in comparison to their isolated counter-parts have been studied. Pairing resulted in significant differences between paired and isolated hamsters in measurements of eggs, miracidia, number of adult worms recovered and mean testicular number of males. Paired hamsters seemed to be immunologically suppressed and such a suppression resulted in increasing the fertility and number of worms recovered. The width of the male schistosomes recovered from the paired hamsters was two folds and the length was four folds greater than those recovered from isolated ones. The mean testicular number was 8.17 +/- 0.53 in males recovered from paired hamsters and 6.16 +/- 0.71 in those recovered from isolated ones. Of interest was, the demonstration of a male with two groups of testes recovered from a paired hamster. It was concluded that the stressed host reflex effects on the number and fertility of the schistosome worms burden, and hence the severity of the disease and its complications.

Ecology of some sympatric reptilian species from Egypt with special reference to helminthic parasites: Ptyodactylus guttatus and Tarentola annularis.

Ptyodactylus guttatus and Tarentola annularis are sympatric throughout most of their geographical distribution in Egypt. Their temporal activities, feeding habits, food items, feeding strategy are almost similar. These species have been harboured 6 species of nematodes, one species of trematodes in addition to helminthic cysts of cestodes in the liver of each specific host.

Morphological and anatomical studies on larval trematode of genus Brachylaima (Brachylaimidae) from the land snail, Monacha obstructa.

The metacercariae of genus Brachylaima were collected from the kidney of the land snail Monacha obstructa. About thirteen to fifteen metacercariae were collected from each snail. The metacercariae observed were elongated rather than oval. The gonads were no so developed inspite of the great similarity between this larval stage and the adults. No larval stages rather than the metacercariae were observed. The specimens were examined in fresh status and then stained with carmine and fast green as counter stain. The excretory system was developed to very great extent. This seems to be the first record of this larval stage in Egypt since 1899 when Looss collected the adult of B. aequans from Gerbillus aegyptiacus. The heavy infection of snails reflects the higher incidence of this parasite among land snails as intermediate host. Since, the life cycle of this parasite is not yet confirmed experimentally in Egypt, the species has not been identified.

The histopathological effect of metacercariae of the genus Brachylaima on the land snail, Monacha obstructa.

The histopathological changes in the kidney of the land snail Monacha obstructa and the histochemistry of the body wall of the parasite were studied. The histological pictures of the infected kidney showed extensive degree of degeneration in the renal tissue with multiple necrotic foci. Due to the mechanical and feeding effects of the parasite, the renal lamellae were disintegrated. Also, suckers increased the renal damage. In some levels of the kidney, the renal tissue was completely disappeared except the connective tissue of kidney capsule. Also, it was observed that there was a clear space between the parasites and renal tissue probably as a trial of evasion from the Host's reaction. The histochemical study on the metacercarial body wall revealed that it is consisting of three layers arranged as outer, middle and inner layers. Staining with Periodic Acid Schiff proved that the body wall is rich in mucopolysaccharide content. The idea that this parasite can be used as a biocontrol agent is also discussed.

Decentered Gaussian beams.

A generalization of the Gaussian beam is obtained by introducing a complex-valued shift in the transverse dimension. The resulting beam has a Gaussian intensity distribution with width varying as an ordinary Gaussian beam, but whose peak traces an inclined linear trajectory. The wave fronts are displaced laterally in a sheared fashion. This generalized beam preserves its form after passing through arbitrary paraxial optical components, even if they are decentered. The peak-intensity line is modified by such systems as if it were a ray.

Studies on the nematode parasites from Egyptian rodents. I. Spirurid nematodes.

Three spirurid nematode species have been collected from Egyptian rodents in Giza province. Streptopharagus kuntzi was collected from stomach and small intestine of Rattus ratus, R. norvegicus, Arvicanthis niloticus and Gerbillus gerbillus. Protospirura muris and P. marsupialis have also been collected from A. niloticus, R. rattus and R. norvegicus but P. marsupialis was collected only from the stomach while P. muris collected from stomach and small intestine. P. marsupialis was firstly recorded in Egypt during this work and no males of this species were collected. Females of S. kuntzi and P. muris showed marked dominance over males. Streptopharagus sudanensis and S. kuntzi are placed in synonomy.

Larval occurrence of Hydatigera taeniaeformis Batsch (1786) (Cestoda: Taeniidae) in the liver of wild rodents in Egypt.

Hydatigera taeniaeformis Batsch (1786) was found in the liver of six species of Egyptian wild rodents. Wanas et al., (1990) found the total incidence of this larval stage to be 20.0% among cestode infection. It was found in (40.9%) Rattus norvegicus; (33.3%) Gerbillus gerbillus; (26.8%) Rattus rattus; (25.0%) Mus musculus; (16.6%) Acomys cahirinus; and (7.2%) Arvicanthis niloticus. The cysts of Hydatigera taenioformis was always occupying the marginal surfaces of both right and left lobes and sometimes there was a double cyst contained two strobilae. The rostellar hooks used for identification. The strobilae obtained were in different stages of development. The rostellar hook system was complete and so the suckers but the segment showed no maturation. Morphological characters and role of rodents as intermediate host for such cestode are discussed.