Immunotherapeutic effect of spiramycin in experimental giardiasis

Giardiasis is a major global cause of water borne diarrheal disease, which contributes greatly to the burden of malnutrition and malabsorption especially in children. There is a great demand for a new effective therapeutic agent against giardiasis that can be used safely during pregnancy, lactation and in infants. In the present study, the therapeutic effect of spiramycin as well as its immunomodulatory mechanism of action in giardiasis had been investigated. 90 Swiss albino mice were used in this study and classified into 3 groups: GI: 40 mice infected with Giardia lamblia cysts, GII: 40 infected mice that received spiramycin treatment in a daily oral dose of 1000 IU/gm body weight for one week starting one week post infection and GIII: 10 control uninfected untreated mice. 20 mice from each infected group were sacrificed 2 weeks post infection [p.i.] and the remaining mice were sacrificed 4 weeks p.i. Mice of the control groups were sacrificed at one time. The antigiardial therapeutic efficacy of spiramycin was assessed 2 and 4 weeks p.i. by counting of Giardia cysts in stool of mice and studying the histopathological changes and disaccharidase activity in small intestine of mice of different groups. Significant reduction in cysts number shedded in stool of treated animals reached 95.73%. The histopathological changes were mild in all infected groups 2 weeks p.i., while 4 weeks p.i. There was also a significant increase in the number of IELs in treated groups denoting the stimulatory effect of spiramycin on lymphocytic proliferation. On studying the disaccharidase activity, there was significant increase in both sucrase and maltase activities in the treated groups as compared with the nontreated groups. The possible immunomodulatory mechanism of action of spiramycin was studied by measuring the local IgA deposition in small intestinal mucosa by PAP technique 4 weeks p.i. The levels of IgA in small intestine were higher in SP-treated group as compared with the non-treated group. The present results suggested that spiramycin has high efficacy as anti-giardial agent possibly by stimulation of local IgA production

Histochemical effects of some biological agents on culex pipiens larvae

The histochemical effects of the lethal concentration that kills 50% of larvae [LC[50]] of three biological agents, abamectin, Bacillus thuringiensis and spinosad on the carbohydrates [polysaccharides], proteins, nucleic acids and lipids content of the midgut and fat bodies of Culex pipiens 2[nd] instar larvae were studied. The results showed that the three tested compounds reduced the carbohydrates [polysaccharides], proteins, RNA synthesis and lipids content after 72 hours of treatment where abamectin was the most effective followed by Bacillus thuringiensis then spinosad

possible synergistic effect of gossypol [cottonseed oil] and schistosomiasis mansoni on the male reproductive organs in experimentally infected mice

Gossypol is considered as the major toxic ingredient in the cotton plant which affects the male fertility in countries where crude cottonseed oil is used extensively for cooking as in Egypt. In rural areas in Egypt, there is a common association between schistosomal infecion that can affect the male genital organs and gossypol intake through increased consumption of cottonseed oil. Whether this synergism plays a role in enhancing male inferility or not, is a matter that needs evaluation. The present study was conducted to evaluate the possible synergistic effect of gossypol as one of food pollutants and schistosomiasis mansoni on the male reproductive organs in experimental animal. One hundred and thirty laboratories bred, parasite free, male Swiss albino mice were used in the current study. Mice were classified into 4 groups: Group [I]: consisted of 40 mice which remained none infected but received gossypol orally for 4 weeks. Group [II]: consisted of 40 mice which were infected with Schistosoma mansoni and did not receive gossypol. Group [III]: consisted of 40 mice which were infected and received gossypol orally for 4 weeks staring from the 8th week post Schistosoma infection. Group [IV]: consisted of 10 mice which were none infected and did not receive gossypol. Mice were sacrificed at different durations after gossypol intake and post infection whereas control mice were sacrificed at one lime. The tesis and the epididymis were removed from each animal and their weights were recorded. They were processed for histopathological and immunohistochemical examinalion as well as electron microscopical examinalion. There were histopathological changes in tesicular sections of group [I] starting from the 2nd week after gossypol intake which became marked later on with depletion of germ cells and spermatozoa in testis and cauda epididymis. Regarding group [II], the pathological changes were rather mild. In group [III], the pathological changes appeared at the 10 week p.i. as spermatogenesis was arrested with a marked reduction in the number of mature spermatozoa. Some seminiferous tubules showed degenerative changes of the germinal epithelium, such as vacuolization, disrupion, and even severe destruction. In both S. mansoni infected groups [Gp. II and III], neither ova nor granulomata were detected in all examined histopathological secions while the immunohistochemical staining showed posilive deposilion of S. mansoni anigen in the testes and epididymes. In addilion, electron microscopical examination showed similar results at the ultrastructural level. Although schistosomiasis mansoni can affect male organs by antigen deposition, it's not a major cause for male infertility, while gossypol is a major culprit where cottonseed oil is used. Acing together, these two culprits exert a synergistic effect on male fertility. Therefore, gossypol should be handled more cautiously. In addition, using crude gossypol for male contracepion in Egypt is not recommended, because its synergism with schistosomiasis may render its effect irreversible

Immunohistochemical and neurotransmitter changes in the brain of mice infected with hymenolepis nana

Hymenolepis nana is one of opportunistic parasites which is widely distributed specially amongst children and immunosuppressed patients. Some neurological manifestations can occur in immunosupressed hosts, however, their possible pathogenesis is not clearly yet idenified. The aim of the present work is to study the possible pathogenesis of the neurological manifestations in Hymenolepis nana infection. Swiss albino mice were used in this study which was divided into two groups. Group I: Mice were maintained immunocompetent [IC]. Group II: Mice were immunosupressed [IS] by subcutaneous injection of cortisone. Mice of both groups were orally infected with H.nana eggs. Mice were sacrificed at different durations post infecion [p.i.]. Small intestine, liver and brain of each sacrificed mouse were removed. Couning of cysticercoids and adult worms in small intestine was performed. Livers were examined histopathologically for the possible cysticercoid disseminalion. Brains were processed for histopathological examination and immunohistochemical examinalion for the possible antigenic deposition by PAP technique. In addition the brain tissue was processed for biochemical estimation of the levels of some neurotransmitters as: Gamma-aminobutyric acid [GABA], norepinephfine [NE] and serotonin [5-HT] as well as zinc as one of trace elements. The results of the present study showed a significant increase in the number of cysicercoids and adult worms with delayed expulsion in immunosupressed [IS] mice with manifest histopathological changes in small intestinal mucosa. Aberrant cysticercoids were detected in the liver of IS mice. Regarding the brain examination, there were marked histopathological changes with specific antigenic deposition in IS mice. There were statistical increase in the levels of GABA and NE and staistical decrease in the levels of 5-HT and zinc in brains of IS mice examined at 3 and 5 months p.i. On the basis of the results of the present study, it has been shown that in case of immunosuppression, Hymenolepis nana infection can affect the brain as evidenced by the marked histopathological changes, specific antigenic deposition and the significant changes in the levels of neurotransmitters and zinc in the brain tissue. Since H. nana is widespread and since increasing numbers of patients are given immunosuppressive treatment, it is possible that this peculiar neurological manifestation of H.nana infection is occurring but not being diagnosed. The pathogenesis of such manifestations seemed to be dependent on multifactors that acting together and affecting each other

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

Hypothalamic origin of reproductive failure in chronic experimental toxoplasmosis

Laboratory bred female mice were used to study the effect of chronic toxoplasmosis on reproductive performance. The animals were infected with small dose [3 x 103] tachyzoites of Toxoplasma parasites. The female mice were mixed with normal males for one week, then separated to monitor their reproductive performance one and two months post- infection [pi]. Mice bred one-month pi showed reproductive failure with one of twenty females delivered two sick newborns. The others did not complete pregnancy and fetal wastage occurred. Mice bred two months pi were infertile. Histopathological examination of the ovaries revealed impaired folliculogenesis and atropic degeneration. Coronal sections of cerebrum showed widespread vasculitis and focal disruption of the ependymal cells lining both lateral and third ventricles. The supraoptic and paraventricular hypothalamic nuclei were deformed and showed pyknotic neurons. Immunoperoxidase staining was used to detect IgG and IgM deposits in brain tissue. IgG deposits were found on the vicinity of Toxoplasma cysts and focally in the paraventricular zone. So, the reproductive failure of infected mice was due to hypogonadotrophic hypogonadism secondary to hypothalamic dysfunction as a result of chronic toxoplasmosis