Protective capacity of cercarial transformation fluid alone or in combination with crude cercarial antigen against challenge infections of Schistosoma mansoni in mice.

Schistosomiasis is the second major parasitic disease in the world after malaria. It affects 201.5 million cases in Africa alone. The aim of this research was to explore alternative vaccination strategies against experimental schistosomiasis mansoni. We assessed the effect of cercarial transformation fluid (CTF) singly and in combination with crude cercarial antigen (CCA) using alum as an adjuvant. The combined antigens gave the best results, as evidenced by a significant reduction in the worm load (62.07%), tissue egg count (78.16%, 86.46%) in liver and intestine respectively, and hepatic granuloma size (29.96%). Scanning electron microscopy revealed changes in the tegument, in the form of roughness and appearance of vesicles and furrows between the tegumental tubercles. Also, resorption of the ventral sucker and dimples replacing its spines were observed. The female tegument was irregular and its posterior end showed loss of spines and sensory bulbs. Moreover, there was a significant decrease in liver enzymes (alanine transaminase (ALT) and aspartate transaminase (AST)) compared to infected control mice. A significant elevation in CD4+T-lymphocytes, denoting amelioration of the immune status, in mice that received combined antigens was also observed. It can be concluded that combined antigens demonstrate potential as a vaccine against Schistosoma mansoni.

In-pouch TV culture system in diagnosis of Trichomonas vaginalis infection.

A newly simplified culture method, the In-Pouch TV culture system, the wet mount (WM) examination and the acridine orange stain were compared with the Oxoid culture as a standard technique in the diagnosis of trichomoniasis. Out of 70 symptomatic cases enrolled in this study, 28 specimens were positive by all methods. Among these positive specimens, 21 were positive by the Oxoid culture (75%) and 24 (85.7%) with sensitivity of 85.7% by the In-Pouch system. Both wet mount preparation and acridine orange stain had less sensitivity than the In-Pouch system (61.9%) and detected 15 (53.6%) and 16 (57.1%) of the cases respectively. The In-Pouch system has been proved to be easier in the transport and culture technique than the ordinary culture method. It alleviates the need to enter the culture, thus prevents contamination. Its cost is comparable to the ordinary culture tube. Therefore, it is recommended to use the In-Pouch culture system as a method of diagnosing trichomoniasis.

Diagnosis of toxoplasmosis in immunosuppressed mice using the polymerase chain reaction (PCR) and the enzyme linked immuno-sorbent assay (ELISA) techniques.

In the present study, Toxoplasma infection with the virulent and avirulent strains in both immunocompetent and immunosuppressed mice was diagnosed using the MDS ELISA for detection of CA in sera and the PCR for demonstration of DNA in livers, brains and mononuclear cells of blood. Both techniques proved to be convenient, especially in immunosuppressed mice.

Autoclaved cercarial vaccine against schistosomiasis: ultrastructural and biochemical studies.

Autoclaved cercarial vaccine (ACV) was found to be highly effective in eliciting protective immunity against experimental Schistosomal mansoni. So, the aim of this study was to analyse ACV biochemically and to study ultrastructural changes inflicted on the cercariae as a result of autoclaving, thus rendering it highly protective. Results of this study showed that approximately 100 microg protein and 44 microg carbohydrate were obtained from 10(3) cercariae. The predominant sugar was fucose. Galactose, glucose, manose, galactosamine and glucosamine were also detected. Threonine, glycine, serine and glutamic acid comprised approximately 53.7% of the amino acid residues of the protein. Ultrastructural study revealed preserved architecture of the cercariae. The tails were still attached to the posterior ends of the bodies. However, in others the tails were separated from the bodies and appear schistosomula like. There were also some morphological changes such as thinning of the pericortical envelop with appearance of surface pores.

Novel triazolo[4,3-a]quinazolinone and bis-triazolo[4,3-a:4,3'-c]quinazolines: synthesis and antitoxoplasmosis effect.

Several quinazoline derivatives containing substituted thiosemicarbazido and S-methylisothiosemicarbazido groups at the 2-position and at both the 2- and 4-positions have been synthesized. Treatment of the S-methylthiosemicarbazides with morpholine or diethylamine did not give the corresponding guanidines. Instead, they underwent cyclodesulfurization into the condensed ring systems, [1,2,4]triazolo[4,3-a]quinazolinones and bis-[1,2,4]triazolo[4,3-a:4'.3'-c]quinazolines. Evaluation of the products for antitoxoplasmosis effect by studying the ultrastructure morphology of the organisms using scanning electron microscopy (SEM) indicated their efficacy in causing structural deformity of Toxoplasma gondii. Such a deformity plays an important role in obstructing the entry of the organisms into host cells.

Autoclaved cercarial vaccine: a new hope against schistosomiasis parasitologic, histopathologic and immunologic studies.

The efficacy of autoclaved cercarial vaccine (ACV) in eliciting protective immunity against Schistosoma mansoni infection was investigated in Swiss strain Albino mice. Two main groups of animals were used. One served as control group and the second was vaccinated with ACV mixed with Bacille Clamette-Guerin (BCG) as an adjuvant, in a single, double and triple doses 2 weeks apart. Six weeks after the first vaccination, all animals were challenged with freshly liberated cercariae of Schistosoma mansoni then sacrificed 7 weeks later. Parasitological, histopathological and immunological studies showed promising results which gave hope in evolution of anti-schistosomal vaccine.

Detection of Cryptosporidia in different water sources in Alexandria by monoclonal antibody test and modified Ziehl Neelsen stain.

Cryptosporidium paruum has become one of the most important contaminant found in drinking water and is associated with high risk of waterborne diseases particularly for the immunocompromised. In the present study, Cryptosporidium was found in uncovered water tanks, nearby the shore in El Noubareya and El Mahmoudeya canals and in one swimming pool. Direct flourescence monoclonal antibody was more sensitive in detecting the organism. Ziehl-Neelsen although less sensitive, yet it has the advantage that it could recognize other protozoa causing diarrhoea as G. lamblia, B hominis and Cyclospora sp.

Studies on experimental mixed infection of Schistosoma haematobium and Schistosoma mansoni.

Swiss Albino mice have been infected with S. haematobium and challenged 4 weeks later with S. mansoni. Parasitological, pathological and ultrastructural studies were done. The results revealed cross mating between the two species. A reduction in S. mansoni worm load, egg count, hepatic granuloma number and size was noticed. The presence of heterologous immunity was suggested.

Study and characterization of different developmental stages of Leishmania major.

The complete developmental cycle of Leishmania major in axenic culture was achieved by simply changing the temperature whether sudden from 22 degrees C to 37 degrees C or stepwise 22 degrees C, 29 degrees C and then 37 degrees C. The morphology by light microscopy, GPI isoenzyme pattern and PCR amplification of minicircle of kinetoplast DNA of the different stages were studied. The amastigotes obtained from the foot pads of mice were compared to those obtained from axenic culture. The GPI isoenzyme pattern and the PCR amplification products showed distinct differences between the promastigotes and the amastigotes. The amastigotes of the two sources also showed differences after temperature changes.

Effect of ivermectin on experimental trichinosis.

Ivermectin is a potent macrolytic lactone causing paralysis in many nematodes and arthropods through an influx of chloride ions across cell membranes. This work was carried out to assess its effect against T. spiralis infection in Swiss albino mice as a single dose treatment. Ivermectin was administered to infected mice: one day before, the same day, 5, 10 and 35 days post Trichinella infection. Assessment of the drug effect was through: a) Parasitological study which included: adult count, Larval count, measurements of the length of the adult females, larvae and the reproductive capacity index; b) Scanning electron microscopic study of the adult & larva. Scanning EM changes were described, the results showed that it was most effective when administered on the same day of infection, its effect diminished progressively thereafter.

Detection of circulating antigens in blood to evaluate treatment of fascioliasis.

This work was designed to assess cure of human fascioliasis after triclabendazole treatment by detection of Fasciola antigen by a modified double antibody sandwich ELISA technique. The results showed that the test detected the antigen in the sera of all studied cases before treatment, while no antigen was detected after treatment. The results may suggest that antigen detection provides an accurate tool for diagnosis as well as the assessment of cure.

Differential study of two strains of Toxoplasma gondii.

This study aimed to differentiate between the virulent and avirulent strains of T. gondii by studying morphometric measurement using C.I.A.S., determination of the relative DNA content and extract, SDS poly acrylamide gel electrophoresis and isoenzyme on cellulose acetate gel. Identifying these differences may be useful in studying different disease types and in pathogenic mechanisms. Besides, the presence of common proteins between them may be of value for diagnostic purposes and for formulation of vaccines.

Effect of mebendazole and ivermectin in experimental hepatic capillariasis B: histopathological and ultrastructural studies.

Although, rodents are the principle hosts of C. hepatica both true and spurious human infections have been reported. Over half of the reported cases, resulted in death with hepatic capillariasis being discovered at autopsy; even in cases which the infection was detected at laparotomy or liver biopsy, the patient died due to the lack of suitable treatment. Therefore, studies on experimental C. hepatica in mice were carried out on the way of reaching a full program for treatment. The drugs used were mebendazole and ivermectin. The alterations noted in the egg shell by TEM suggest the effectiveness of the drugs used, the eggs appeared to be deformed; the outer shell was broken and distorted in several places. Many pillars were fragmented. The inner layer was also affected, where it showed destruction of its outer lamellae. Ultrastructural changes in the liver cells showed dysplastic changes. It may be a sequelae of mechanical injury or direct antigenic insult of the parasite or their toxins on the liver cells. During the course of the present work, it was noticed that most of the granulomata were in the fibrotic stage denoting acceleration in the process of healing of the lesions and no freshly deposited ova and hence no active cellular granuloma.

Anisakiasis of the tonsils.

A six-year-old Indian girl presenting with clinical features of chronic recurrent tonsillitis, had a tonsillectomy. Histopathology revealed a cross-section of an Anisakis worm in the tonsil. This report documents a new location in the human host for this rare parasite.

Effect of mebendazole and ivermectin in experimental hepatic capillariasis: parasitological, scanning electron microscopy and immunological studies.

In this study, mebendazole and ivermectin were tried during three different phases of C. hepatica infection. At an early phase, when immature forms were present both drugs were effective in causing destruction and degeneration of the larvae, thus preventing subsequent growth and maturation and consequently the complete absence of eggs. During the second phase, which is found to be the most critical period the two drugs used led to degeneration and resorption of most of adult worms. In the third phase both mebendazole and ivermectin were effective in decreasing the mean number of eggs. After treatment the topographic changes were in the form of disorganized cuticle of the worms and absence of surface uniformity. Such a disorganized cuticle is vulnerable to be attacked. C. hepatica eggs showed irregularities and longitudinal grooves indicated shrinkage of the shell. The effect of the two drugs indicate that both of them were effective in the treatment of hepatic capillariasis.

Therapeutic effect of triclabendazole in patients with fascioliasis in Egypt. A preliminary study.

Human fascioliasis is becoming an increasingly important clinical and epidemiological problem in Egypt. However, the treatment of the disease presents certain difficulties as the usual known drugs such as emetine hydrochloride and praziquantel do not cure fascioliasis using a single dose. Recently, ten cases were presented with a variability of clinical manifestations suggesting fascioliasis. The indirect haemagglutination test (IHA) was positive with high eosinophilia. SGOT and SGPT were normal & no signs of heart or kidney diseases. After taking the consent of the patients, triclabendazole, a novel benzimidazole compound was given orally in a single dose of 10mg/kg body weight. The results hereby revealed that the general condition and all signs of the patients were ameliorated with a drop in the eosinophilic count, which returned to normal after 2-3 months. Being safe, reliable and easy to administer, triclabendazole is ought to be considered for the treatment of human fascioliasis.

Frequency of Entamoeba gingivalis among periodontal and patients under chemotherapy.

This study was carried out to investigate the frequency of E. gingivalis in the gingival crevices of patients with periodontitis compared to normal subjects. Flagyl therapy was tried in cases with periodontitis. Also the frequency of this amoeba was investigated in patients receiving chemotherapy to be compared to normal subjects. The results revealed that higher frequency was observed in patients with periodontitis and flagyl therapy reduced this frequency. Cases under chemotherapy showed higher frequency than the normal control. Histopathological sections from the gingiva of periodontitis patients did not show any amoeba invading the tissue.

Oral contraceptive pills in experimental schistosomiasis mansoni: parasitological, biochemical, histopathological and ultrastructural studies.

This study examines the effect of intake of oral contraceptive steroid in S. mansoni infected mice as regards parasitological, biochemical, histopathological and ultrastructural changes. Three groups were studied group I: S. mansoni infected mice received contraceptive pills six weeks post-infection (p.i.), group II: S. mansoni infected control and group III: non-infected control. Administration of oral contraceptive pills to S. mansoni infected mice results in significant reduction in tissue egg count with a high percentage of dead eggs as observed in the oogram study. There was statistically significant increase in all parameters of the hepatic functions except the prothrombin activity which showed significant decrease. Histopathological examination revealed less cellular granulomas with marked fibrosis, foci of hyperplastic changes in the liver cells and accentuation of cellular degenerative changes. On the subcellular level, there were marked proliferation and dilatation of rER and SER, evident increase of ribosomes, alteration in mitochondrial cristae with intra luminal inclusions and increase glycogen content of hepatocytes.

The protective role of Fasciola tegument antigen against Trichinella spiralis infection.

Fasciola gigantica tegument antigen was prepared to be used for induction of immunity against Trichinella spiralis in albino mice. The results of the study showed that the antigen was more effective when administered in a dose of 3 micrograms than in a dose of 30 micrograms. This was evidenced by the reduction in adult count 72%, adult length 61.4%, larval count 78.7%, length of muscle larvae 32.2% and the significant reduction in reproductive capacity index.

Cyclosporin A in experimental trichinosis scanning electron microscopic study.

The surface morphology of adult and larvae of Trichinella spiralis after cyclosporin A treatment was studied by scanning electron microscopy (SEM) of fixed, dried and metal coated specimens. The earliest topographic changes revealed in adults after the drug treatment were in form of disorganization of the cuticle especially between the hypodermal pores which appeared somewhat thickened and irregular. Other changes were in form of bullae formation covering the whole width of the adult surface. Other specimens showed wrinkling of the outer layer that was seen later to peel off. In few worms layer outer was damaged releasing some of the internal organs. Smoothing of the cuticle with obliteration of the grooves between the cuticular ridges were observed as the earliest surface larval changes, ulcer formation which was deeply seated was seen in patchy areas in some specimens. The interaction between the parasite surface and the drug is of significant importance as this can throw light on the possibilities of its mode of action.