experimental study for evaluating the efficacy of cercarial vaccine against Schistosoma mansoni

This study assessed the effectiveness of autoclaved cercarial vaccine [ACV] in protection against Schistosoma mansoni infection in 125 Swiss albino mice classified into two main groups: GI: a control group. Gil: a test vaccinated with ACV, in a single dose of 0.1ml of 10[4] ml ACV [G.IIa], double dose; 0.2ml [G.IIb] and two single doses 2 weeks apart [G.IIc]. Four weeks later, all mice were challenged with S. mansoni cercariae and sacrificed 10 weeks post infection [P.I.]. The results revealed that the vaccine in a single dose [G.IIa] induced a high level of protection against S. mansoni infection. There was a significant reduction in the mean number of adult worm [91.12%], ova/gram liver [91.87%], ova/gram intestine [89.09%] and number and size of granulomas in liver [92.92% and 43.53% respectively]. Besides, ACV induced a significant increase in the level of IL-10 mRNA expression as compared to the control group

Food additives and Hymenolepis nana infection: an experimental study

The effect of sodium benzoate [SB] on the pathogenesis of Hymenolepis nana [H. nana] and its neurological manifestations was studied in the present work. One hundred and thirty five mice were classified into three groups. GI: received SB alone, GII: received SB before and after infection with H. nana and GIII: infected with H. nana. All groups were subjected to parasitological, histopathological, immunohistochemical and biochemical assays. The results revealed a significant decrease in TL-4 serum level with a significant increase in gamma amino butyric acid [GABA] and decrease in zinc brain levels in GI, while GII showed non significant increase in IL-4 level that resulted in a highly significant increase in the mean number of cysticercoids and adult worms with delayed expulsion as compared to GIII. This was reflected on histopathological and immunohistochemical changes in the brain. Also, there was a highly significant increase in GABA and decrease in zinc brain levels in GII to the degree that induced behavioral changes. This emphasizes the possible synergistic effect of SB on the neurological manifestations of H. nana and could, in part, explain the increased incidence of behavioral changes in children exposed to high doses of SB and unfortunately have H. nana infection

Potential effect of Curcuma longa extract on infectivity and pathogenicity of Schistosoma mansoni cercariae

Batch of freshly shed cercariae from infected laboratory bred Biomphalaria alexandrina were exposed to different sub-lethal concentrations of turmeric extract for an hour and divided into two groups. The first one was to study the ultrastructural changes induced in them using scanning electron microscopy [SEM]. The second group was to study infectivity and pathogenicity of the exposed cercariae. One hundred and fifty mice were divided into 5 groups: GI: Infected by normal cercariae and served as controls; GII, GIII, GIV and GV infected by cercariae exposed to 2.5, 5, 7.5 and 10 ppm, respectively. Ten weeks post infection all animals were sacrificed and subjected to parasitologic, histopathologic and immunologic assays. SEM showed cercariae exposed to 5ppm with minimal destruction of head spines and tail. The degenerative changes were progressively severe by increasing extract concentration to reach complete destruction of both at 10 ppm. Infectivity decreased with the increase in concentration to reach highest significance at 10 ppm. Pathogenicity or mean number of egg deposited, mean diameter of liver granulomas and level of IL-10 gene expression significantly decreased in Gs IV and V

Effect of organochlorine [DDT] exposure on experimental giardiasis

This work studied the effect of sub-chronic DDT exposure on the course of experimental giardiasis and efficacy of its treatment. A total of 160 mice were divided into six groups: G1: 30 mice received DDT and infected with Giardia lamblia. G2: 30 mice received DDT, infected and treated with tinidazole [TNZ]. G3: 30 mice infected with Giardia. G4: 30 mice infected and treated with TNZ. G5: 30 mice received DDT only. G6: 10 mice served as normal control. Mice were sacrificed at 7, 14, 21 and 28 days P.I. All groups were subjected to cyst count/2 hours collected stool, trophozoite count in intestine, histopathological examination of small intestinal section and avidin biotin peroxidase technique for local IgA staining. Also, IFN-gama was measured in sera. DDT caused early shedding of many cysts and increase in trophozoite counts for a long time, decreased intra epithelial lymphocytes, low levels of IgA and IFN-gama and severe histopathological changes in intestinal sections in G1 as compared to G3. Also, DDT reduced the efficacy of TNZ treatment in G2 as compared to G4. The results strongly support the immunomodulating effect of DDT on experimental giardiasis that might be responsible for persistence of infection, resistance to treatment and re-infection in DDT exposed persons

Genetic polymorphism of glutathione-S- transferase [GST-M1 and GST-T1] in schistosomiasis -associated bladder cancer in Egyptian patients

This work was carried out on three groups, 30 Egyptian patients with Schistosoma haematobium [S. haematobium] with bladder cancer [15], and without bladder cancer [15], as well as 15 normal individuals as a control. All the individuals were subjected to measurement of serum level of GST by using ELISA technique and genotyping for GST-M1 and GST-T1 using PCR technique. The results proved that GST serum level was significantly deceased in S. haematobium patients with bladder cancer as compared to the other groups. The PCR results for the GST-M1 and GST-T1 genotyping showed 4 categories, [M1+ve/T1+ve, M1+ve/T1-ve, M1-ve/T1+ve, M1-ve/T1/-ve]. There was a significant decrease in enzyme levels in patients with GST-M1-ve/T1-ve as compared to the other categories. Besides, there was a significant increased risk for bladder cancer development in patients with combined gene deletion [OR = 40] which represented mainly in S. haematobium patients with bladder cancer [53.3% = M1-ve/T1-ve]

Genetic polymorphism of glutathione-s-transferase [GST-M1 and GST-T1] in Egyptian schistosomiasis -associated bladder cancer

Bladder cancer is a common neoplasm around the world. In Egypt, the majority of bladder cancer is associated with Schistosoma haematobium [S. haematobium]. Glutathione-s-transferase [GST] represents an important family of metabolizing enzymes that catalyzes the conjugation of large variety of endogenous and exogenous compounds including carcinogens and anti cancer drugs and their metabolites with reduced glutathione. Individuals with very low levels of GSTs are at increased risk for the development of carcinoma and inflammatory diseases. The potential role of GST gene polymorphism on bladder cancer susceptibility is less certain. So, the aim of this work was to study GST-M1 and GST-T1 genes polymorphism in Egyptian patients with S. haematobium to clarify its role on bladder cancer susceptibility in those patients. This was carried out on three groups, 15 Egyptian patients with S. haematobium with bladder cancer, 15 Egyptian patients with S. haematobium without bladder cancer and 10 normal individual as a control group. All individuals were subjected to measurement of serum level of GST using ELISA technique and genotyping for GST-M1 and GST-T1 using PCR technique. The results proved that GST serum level in Schistosoma patients without bladder cancer was decreased but not statistically significant if compared to control group, in contrast it was significantly deceased in Schistosoma patients with bladder cancer if compared to the other groups. PCR results for GST-M1 and GST-T1 genotyping had shown 4 categories, in control group [M1+ve/T1+ve [80%], M1+ve/T1-ve[10%], M1-ve/T1+ve[10%], M1-ve/T1/-ve[0%]], in Schistosoma without bladder cancer [M1+ve/T1+ve[66.7%], M1+ve /T1-ve[13.3%], M1-ve/T1+ve[13.3%], M1 -ve/T1-ve[6.7%]], while in Schistosoma patients with bladder cancer [M1+ve/T1+ve[13.3%], M1+ve/T1-ve[13.3%], M1-ve/T1+ve[20%] and M1-ve/T1-ve [53.3%]]. It was demonstrated a significant decrease in enzyme levels in patients with homozygous deletions of both GST-M1 and GST-T1 genes [GST-M1-ve/T1-ve] if compared to the other three categories of genotyping. Moreover, there was a significant increased risk for development of bladder cancer in patients with combined gene deletion [OR=40] which represented mainly in Schistosoma patients with bladder cancer [53.3% were M1-ve/T1-ve]. Bladder cancer is a common multifactorial disease, and genetic polymorphism especially in GST-M1 and GST-T1 could play an important role as a risk factors in development of urinary bladder cancer among Egyptian with Schistosoma haematobium. So, it could be used for early prediction of risk group in order to help them by follow up for early diagnosis or by cancer chemoprotection

impact of subchronic mercury exposure on the immune response and pathogenesis of experimental cryptosporidiosis

Mercury is one of the most widely distributed heavy metal which incriminated in the environmental pollution. Evidence is emerging that chronic exposure to mercury may elicit immunomodulation with enhanced host susceptibility to bacterial, viral and parasitic infection. Therefore a special attention is payed in this study to test the impact of subchronic mercury exposure on the immune response and the pathogenesis of experimental cryptosporidiosis. One hundred and sixty, parasite free, albino mice were used in this study and were divided Into four groups:-Group [1]: consisted of 50 mice which received an oral daily dose of mercury for 28 days before infection with Cryptosporidium oocysts. Group [2]: consisted of 50 mice which infected with Cryptosporidium oocysts without mercury treatment, Group, [3]: consisted of 50 mice, which received mercury treatment only and Group [4]: consisted of 1.0 mice with no infection and no mercury treatment [control group]. The influence of the subchronic mercury exposure on the pathogenesis of cryptosporidiosis will be assessed by counting the fecal oocysts, histopathological examination of different organs of infected mice and biochemical estimation of the glycogen and protein contents in both liver and heart tissues at early stage of infection, Lastly, the levels of IFN-gamma and IL10 in the sera will be measured during the course of experiment. The results of the present work showed that group [1] had shorter prepatent period as fecal oocysts could be detected from first day post infection, remained infected longer and shed more oocysts with higher mortality rate as compared to group [2]. In addition, a significantly higher number of endogenous stages were detected in group [1] with severe villous atrophy and heavy infestation with the endogenous stages than in group [2]. Regarding the levels of glycogen and protein, groups [1and 2] showed statistically significant decrease in the level of glycogen in liver and heart tissues whereas, the level of protein increased in the liver unlike the cardiomyocyte that showed marked protein decrease as compared to other groups. Moreover, there was a statistical significant increase in the levels IFN-gamma and IL10 in group [2] as compared the lower levels detected in group [1], Therefore, the result of the present work strongly support the immunosuppressive effect of mercury on experimental cryptosporidiosis as evident.by flaring up of the intestinal infection with the extraintestinal spread of the parasite as well as the induction of functional impairment in liver and heart tissues. Therefore, these results would spotlight on the wide spread environmental pollution with mercury which may be incriminated in the flaring up of the opportunistic parasites specially among children and its possible hazardous effect on their health