The record of Vannella species (Vannellidae, Discosea, Amoebozoa) from freshwater sources in Dakahlyia Governorate, Egypt.

The River Nile is the main source of fresh water in Egypt, where its water is used for irrigation, drinking, fisheries, industrial uses, and recreation. For sustainable utilization of the River Nile and its branches in the Nile Delta region, it is necessary to monitor regular investigation for the biodiversity of protozoan fauna in the Damietta branch and other freshwater canals in Dakahlyia Governorate. Water samples were collected monthly from different water sources, for 1 year, and examined for protozoans, using phase-contrast microscopy and recorded video films, The genus Vannella Bovee 1965 is recorded for the first time in four freshwater localities: Demietta branch of the River Nile, Mansouria Canal, Bouhia Canal, and Bahr El-Saghir Canal. A detailed morphological description with a brief report of their locomotion has been given for four morphologically different Vannella species. The locomotive form of Vannella sp.1 has a long pointed posterior tail and 2 lateral posterior processes. Such a tail was absent in other Vannella species. Vannella sp.2 is unique among other recorded species, where its locomotive form possesses a long posterior rounded tail region and a frontal hyaloplasm provided with a wavy surface that forms several lobes and finger-like processes during locomotion. In addition, the hyaloplasm produces several transverse waves that vary in thickness and density. The floating form of Vannella sp.2 is of a radial type and has comparatively long hyaline pointed and spiral pseudopodia. The process of transformation of locomotive form to floating form in Vannella sp.2 has been followed up using several recorded video films. The locomotive form of Vannella sp.3 is bear-shaped, while that of Vannella sp.4 has variable shapes from semicircular to rectangular and sometimes fan-shaped. During movement in vivo, locomotive cells of all Vannella species, except Vannella sp.1, move in nearly a straight line, but there were variations in their rate of locomotion. Vannella sp.4 recorded the highest rate (6.8 µm/s), followed by Vannella sp.2 (4.5 µm/s), Vannella sp.3 (2.4 µm/s), and finally Vannella sp.1 (1.0 µm/s). Molecular studies and transmission electron microscope examinations are still needed to confirm the precise identity of each Vannella species.

Comparative ultrastructural observations of the Egyptian schistosomes: Schistosoma mansoni and Schistosoma haematobium.

An ultrastructural topography has been made to the tegumental architectures of two Egyptian schistosomes namely S. mansoni and S. haematobium hosted in a model animal namely Cricentus auratus. The distribution of sensory papillae on the oral sucker were arranged in one circle around the rim in addition to some papillae in upper part of inner zone in male, female S. mansoni and in male S. haematobium. The differences in the types of papillae, their distribution and shape of ridges on various parts of the body surface which are quite specific for each species was studied. Also, the ventral tegument of female's displays larger and more numerous sensory papillae. Both ciliated and non-ciliated papillae were observed in this work which makes a link with another species of schistosome S. japonicum. Another characteristic feature in this study is unique of male of S. haematobium, the extensive formation of ridges and transformation to microvilli in the posterior region in males. These finding may provoke further study of schistosomes hosted in animal model for more detailed investigation at the molecular level.

Cholinergic components of nervous system of Schistosoma mansoni and S. haematobium (Digenea: Schistosomatidae).

A comparison has been made for the first time between the cholinergic components of the nervous system of important human digeneans namely Schistosoma mansoni and Schistosoma haematobium from infected hamster (Cricentus auratus) in Egypt. In each parasite, the central nervous system consists of two cerebral ganglia and three pairs of nerve cords (ventral, lateral, and dorsal) linked together by some transverse connectives and numerous ring commissures. Peripheral cholinergic innervation was detected in oral and ventral suckers and in some parts of female reproductive system in both species, but there were some differences. The possible functions of some of these nervous components are discussed.

Transmission electron microscopic observations on ultrastructural alterations in Schistosoma mansoni adult worms recovered from C57BL/6 mice treated with radiation-attenuated vaccine and/or praziquantel in addition to passive immunization with normal and vaccinated rabbit sera against infection.

Although the current treatment of schistosomiasis relies largely on praziquantel (PZQ), it has not been successful in significantly reducing the overall rate of disease cases, one of the suggested reasons being the inevitable resistance to PZQ. Previous studies showed that radiation-attenuated vaccine provides protection against Schistosoma mansoni in a host of various species. In the present study, we evaluated the effect of various vaccination strategies in C57BL/6 mice, including single or multiple vaccination strategy, subcurative dose (20 mg/kg) of PZQ, and a combination of single vaccination with subcurative dose of PZQ. Treatment either with subcurative dose of PZQ or with a single vaccination of attenuated cercariae (500 per mouse), caused significant reduction in total worm burden, hepatic, and intestinal ova counts of 43.03, 73.2, and 59.5 and 37.97, 52.02, and 26.3%, respectively. Furthermore, tegumental changes were observed. In multiple vaccinated group, there was an extensive lysis in tegumental layers. High deformations in gastrodermis, testis cells, vitelline cells, and oocytes were recorded. Also, this study is to explore the role of humoral immunity using highly resistant rabbits that had been exposed to three immunizations with ultraviolet (UV)-irradiated cercariae (8000 per rabbit in each immunization), and their sera were tested for their ability to transfer protection. The reduction in challenge worm burden had reached 32.76-43.64% when compared with recipients of normal serum or no serum. The reduction in hepatic and intestinal ova counts reached to 74.4 and 71.08% in group immunized with vaccinated rabbit sera. Swelling and extensive lysis of tegumental layers, gastrodermis lumen, spermatocytes, and deformation of oocytes were recorded with more severity than that recorded in normal rabbit sera group. Our findings recorded that multiple vaccination strategy is the most effective strategy then passive transfer of vaccinated rabbit. This gives guiding in the design the appropriate therapeutic strategy.

Ultrastructural changes of adult Schistosoma mansoni worms recovered from C57BL/6 mice passively immunized with normal and vaccinated rabbit sera in vivo.

The purpose of the study is to explore the role of humoral immunity against Schistosoma mansoni infection in C57BL/6 mice using highly resistant rabbits that had been exposed to three separate immunizations with ultraviolet (UV)-irradiated cercariae (8,000 attenuated cercariae/rabbit in each immunization), and their sera were tested for their ability to transfer protection against S. mansoni challenge. The present study showed the reduction in challenge worm burden had reached 32.76-43.64% when compared with recipients of normal serum or no serum. The surface topography of the worms collected from immunized mice with either normal rabbit sera (NRS) or vaccinated rabbit sera (VRS) revealed severe tegumental alterations, especially in the VRS group. Worms collected from groups that were immunized by NRS or VRS postinfection (200 normal cercariae/mouse) by day 42. Worms from group immunized with NRS showed damage in the tegument, characterized by severe swelling or erosion of tegumental folds, accompanied by changes in tubercles, swelling, shortening, and loss of spines in male worms. The alteration in female tegument was characterized by swelling of tegumental folds, atrophy of ventral sucker, damage of sensory papillae along all the body, severe peeling in some regions, and appearance of few small blebs. VRS induced more severe tegumental damage than NRS in both male and female worms. Severe shrunken vesicles were protruded from the surface between the two suckers. The tegument of the male showed a collapse of tubercles followed by the appearance of vesicles on their surfaces, fusion, erosion, and superficial focal peeling of tegumental folds. In the female worms, severe damage to the oral sucker, the surface between the two suckers, extensive peeling, severe swelling of the tegument, and damage of sensory papillae. In conclusion, the present study support the hypothesis that high levels of antibodies were developed in rabbit sera after multiple exposures to attenuated cercariae of S. mansoni. Furthermore, immunization might have transferred protection against the infection, indicated by severe morphological alterations, a sign of elimination of the worms. Further investigation is being carried out to reveal the molecular mechanisms underlying the transfer of protection.

Identification of 123 previously unreported mutations in the F8 gene of Iranian patients with haemophilia A.

In Haemophilia A (HA), the deficiency in coagulation factor VIII is caused by mutations in the F8 gene. In the past, HA carrier detection in Iran used to be carried out by tracking polymorphic DNA markers - a technical strategy with poor efficacy and accuracy. For some 10 years, however, mutations have been identified by direct DNA sequencing at the Iranian Comprehensive Haemophilia Care Centre (ICHCC), resulting in the detection of 580 different mutations and accurate carrier detection. The aim of this study was to characterize and report the unreported mutations not recorded in the F8 HAMSTeRS database and HGMD, which we have detected amongst all the mutations hitherto identified. After excluding introns 1 and 22 inversions, direct DNA sequencing was used to detect mutations among our patients. These were then confirmed in another affected relative or obligate carrier. Severe cases of HA, where no mutation could be identified, were further investigated by the MLPA method. The new, unreported mutations identified include: 51 missense, 15 nonsense, 45 frame-shifts, 11 splice-site, 1 duplications. We report a large spectrum of mutations identified in the course of the past 10 years at the ICHCC, which offers this service to all patients from regions throughout Iran. Aside from the common introns 1 and 22 inversions, this work demonstrates a high degree of heterogeneity in F8 mutations. The establishment of a comprehensive Iranian HA database will improve the care and genetic counselling of Iranian HA families.

Structural changes of Schistosoma mansoni adult worms recovered from C57BL/6 mice treated with radiation-attenuated vaccine and/or praziquantel against infection.

Although the current treatment of schistosomiasis relies largely on praziquantel (PZQ), it has not significantly reduced the overall number of disease cases, perhaps due to inevitable resistance to PZQ. Previous studies showed that radiation-attenuated vaccine gives protection levels for Schistosoma mansoni in host various species. In the present study, we evaluated the effect of various vaccination strategies in C57BL/6 mice, including single or multiple vaccination strategy, subcurative dose (20 mg/kg) of PZQ, and a combination of single vaccination with subcurative dose of PZQ. Groups of five mice were sacrificed postinfection in 42 days and schistosomes were collected by perfusion and examined by scanning electron microscopy. Treatment either with subcurative dose of PZQ or with a single vaccination of attenuated cercariae (500 per mouse), caused significant reduction in total worm burden, hepatic and intestinal ova counts 43.03%, 73.2%, 59.5% and 37.97%, 52.02%, 26.3%, respectively. Furthermore, tegumental changes were observed, including severe swelling, fusion of tegumental folds, vesicle formation, and loss or shortening of the spines on the tubercles. However, multiple vaccination strategy resulted in much higher reduction in total worm burden, hepatic and intestinal ova count. However, multiple vaccination strategy resulted in high reduction of worm burden, hepatic and intestinal ova counts 72.5%, 90.7%, 65.79%, respectively, and further causing swollen, disruption of tubercles teguments and erosion, extensive peeling, fusion of tegumental folds. Our findings suggest that multiple vaccination strategy is the most effective strategy to clear schistosomal infection, indicating its potential in guiding the design of appropriate therapeutic strategy against schistosomes.

The molecular analysis of von Willebrand disease: a guideline from the UK Haemophilia Centre Doctors' Organisation Haemophilia Genetics Laboratory Network.

von Willebrand disease (VWD) is a common autosomally inherited bleeding disorder associated with mucosal or trauma-related bleeding in affected individuals. VWD results from a quantitative or qualitative deficiency of von Willebrand factor (VWF), a glycoprotein that is essential for primary haemostasis and that carries and protects coagulation factor VIII (FVIII) in the circulation. Through characterization of the phenotype and identification of mutations in the VWF gene in patients with VWD, understanding of the genetics and biochemistry of VWF and VWD has advanced considerably. The importance of specific regions of VWF for its interaction with other components of the vasculature has been revealed, and this has facilitated the formal classification of VWD into three subtypes based upon quantitative (types 1 and 3) and qualitative (type 2) deficiency of VWF. The underlying genetic lesions and associated molecular pathology have been identified in many cases of the qualitative type 2 VWD variants (2A, 2B, 2M, 2N) and in the severe quantitative deficiency, type 3 VWD. However in the partial quantitative deficiency, type 1 VWD, the picture is less clear: there is a variable relationship between plasma levels of VWF and bleeding, there is incomplete penetrance and variable expressivity within affected families, the causative molecular defect is unknown in a substantial number of cases, and even in those cases where the causative mutation is known, the associated molecular pathology is not necessarily understood. This guideline aims to provide a framework for best laboratory practice for the genetic diagnosis of VWD, based upon current knowledge and understanding.

Abnormalities of factor VIII related protein multimers in the haemolytic uraemic syndrome.

Factor VIII related activities and factor VIII related antigen multimeric analysis have been assessed in two sporadic and eleven epidemic cases of haemolytic uraemic syndrome. In all patients factor VIII related antigen was raised and had an abnormal multimer pattern at presentation. The return to normal of factor VIII related antigen values and multimeric analysis patterns paralleled clinical improvement and, therefore, may be useful in monitoring patients with haemolytic uraemic syndrome. We postulate that endothelial cell damage releases the abnormal high molecular weight factor VIII related antigen multimers and that this may cause platelet agglutination in vivo.

Simultaneous inheritance and expression of classical haemophilia A and type IIA von Willebrand's disease.

A family is described in which the mother is a haemophilia carrier, the father has asymptomatic type IIA von Willebrand's disease, and their second son has simultaneously inherited both severe haemophilia and type IIA von Willebrand's disease. This is the first report of both diseases occurring simultaneously. The inheritance patterns and laboratory data on the family are presented and discussed.