RAAFAT MOHAMED | Umm Al-Qura University, Makkah, Saudi Arabia (original) (raw)
Papers by RAAFAT MOHAMED
The Journal of Immunology, Dec 15, 1999
Parasitology International, 1998
In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytok... more In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytokine response in Schis~osomajaponi~~~ infection, C57BU6 mice were infected with 50 cercariae of a zoophilic Taiwan strain of S. juponicum and sacrificed 3 to 12 weeks later. The cytokine mRNA expressions were detected with the reverse transcription-polymerase chain reaction and the cytokine protein productions were measured by the enzyme-linked immunosorbent assay. Six cytokines: IFN-y, IL2, R-4, R-5, IL-lo, and TNF-a were evaluated. The results showed that IFN-7 mRNA level increased significantly at 3-4 wk postinfection, and started to decrease at 5 wk, reaching the preinfection level at 6 wk. The IL-4 and IL-IO mRNA levels, however, began to rise at 7 wk and reached the peak at 8 and 9 wk, then declined at 9 and 12 wk. respectively. The TNF-a response was similar to IL-IO pattern The study on cytokine protein production showed that IFN-7 is the major immune response before the egg laying. On the other hand, Th2 cytokine IL-4 is the major response after the egg laying when the production of TIN-7 is suppressed. These findings indicated that the Thl response is involved in the early stage of infection (3-5 wk), while the Th2 response and TNF-a production are the major phenomena associated with the acute stage of infection (7-12 wk)
Parasitology International, 1998
Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-... more Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-Egyptian equines were strrdiecl tracroscopically and by light microscope; apd for the first time by the scanning electrc.rtt nticroscope with particular reference to the anterior cephalic iegion and the nevrll, discovered sensory array of the mouth hooks, Tlre clcsign ot'thit array was cotttl.riu'c<l rvith that of larvae ol Gosterophiltts intestinalis and Gasterophilrts nasalls anrl ',vas ftrurtd to bc diffcrcnt tttairtly irr thc shape of the sensilla and the number of the angled ptates and that these fine criteria rnay be usecl to differentiate other larvac. Irr atltlitiort, ltrore dctailed clescription rvas added to the cephalic ancl caudal regions rvltich are ol'intl;ortant taxonomic value. GasteropSiline larvae are of vetcrinary anrl rttcdical irtlportance, rvitlt some httmatt creeping cutaneous nryiasis, ophtltalrnorrryiasis artd ottc reccttt rccord of intestinal myiasis.
For schistosonriasis, the development of long-lasting protective immunity through rraccination ma... more For schistosonriasis, the development of long-lasting protective immunity through rraccination may be the real solution to control the ciisease spread. The cegument which is the parasite outer coverinq serves as an interface between the host immune system and the parasite. Thus, antigens associated with the tegument have been a major focus for either vaccine development or immunodiagnostic reagents for schistosomiasis. In the present study pooled sera collected from Schistosome mansoni chronically infected patients was purified over a column made of 7-days schistosomula NP40 extract , then used to immunoscreen )" gt|l cDNA library of 7-days schistosomula , a number of cDNA clones were identified after three rounds of -.--immunoscreening and plaques purification. The isolated plaques were amplified rvith polymerase chain reaction (PCR) using I gtl I fonvard and reverse primers. The PCR products were cloned in PCRTNII plasmiC vector. Ail isolated clones were sequenced, the identified clone -s was found to encocie an alpha tubulin like gene. The
Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis i... more Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis infection in females attending the Running title: Sensitivity and specificity of T. vaginalis diagnostic methods Abstract Background and Objectives: Trichomoniasis affects approximately 180 million women worldwide. It cau have an atypical or even asyrnptomatic course. Therefore, to accurately diagnose this disease, microbiological investigation is necessary. The aim of
Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) ... more Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) together with ditferent cytokine adjuvants (lnterferon-gamma and Interleukin-4) were used to immunize mice against. S. nttutsoni.
Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma n... more Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma ntansoni are exposed to host tissucs and thus present potcnthl condldatc moleculcs for the developmcnt of nerv vaccine.
Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on ... more Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on earth and highly prevalent in most warm-blooded vertebrates. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance in disease control. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote T-helper 1 (Th1) responses, an adjuvant activity that is desirable for vaccination against intracellular pathogen. In this study, we compare the immune responses of Toxoplasma susceptible C57BL/6 mice following intranasal and intramuscular vaccination with Toxoplasma lysate antigen (TLA) with or without CpG ODN as adjuvant. Immunized and control non-immunized mice were challenged with 85 cyst of the moderately virulent Beverley strain of T. gondii. Intranasal vaccination gave significantly a higher protection compared to other groups as indicated by prolonged survival and significantly reduced brain cyst burden (P< 0.01). Intranasal vaccination stimulated cellular immunity towards Th1 response characterized by significant INF-γ production (P<0.01). Furthermore, fecal IgA antibody levels as an indicator of mucosal immune responses were significantly higher (P<0.05) in intranasal vaccinated group before the challenge compared to all other groups. Intranasal vaccination was not able to upgrade the Th1 humoral arm. In contrast, intramus-cular vaccination enhanced humoral immunity towards a type Th1 pattern characterized by a significant increase of specific IgG and Ig2a. Our results suggest that intranasal administration of CpG/TLA would provide a stable, pronounced, and effective vaccine against toxoplasmosis through stimulation of Th1 cellular immunity and mucosal IgA.
As part of a search for good animal models for human schistosomiasis, two miniature pigs of the C... more As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17 – 20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.
Background: Cordylobia anthropophaga, one of the known furuncular myiasis-associated fly, has lon... more Background: Cordylobia anthropophaga, one of the known furuncular myiasis-associated fly, has long been limited to the Afro-tropical region. In Saudi Arabia, Southwest region, part of the Afro-tropical region, has been considered the sole endemic region of C. anthropophaga outside Africa. Aim: The aim of current study was to investigate suspected cases of myiasis recorded among 7 different children belonging to 3 different households in Makkah province, Midwest of Saudi Arabia. Methodology: The cases were referred to the Maternity and Children Hospital on 3 different occasions extended from September 2014 to February 2016. All cases were subjected to history taking and clinical examination. Suspected maggots were recovered from associated lesions and were subjected to thorough parasitological and taxonomic examination. Results: Clinical examination revealed suspected lesions of cutaneous myiasis in different parts of children bodies. History taking revealed no past history of wounds or travelling to Southwest region or tropical sub-Saharan Africa. Based on shape, size, cuticle spine pattern and the posterior spiracles, suspected maggots were identified as 3 rd instars of C. anthropophaga. Conclusion: To the best of our knowledge the current study is the first record of indigenously acquired cases of C. anthropophaga-induced furuncular myiasis in Midwest region of Saudi Arabia. This interesting finding might denote a remarkable change in the geographic epidemiology of C. anthropophaga with the first known incidence of autochthonous transmission pattern outside its conventional Afro-tropical endemic region. Indeed, further investigations are required to confirm this interesting record.
The Journal of Immunology, Dec 15, 1999
Parasitology International, 1998
In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytok... more In order to investigate the host immune response and to analyze the kinetics of Thl and Th2 cytokine response in Schis~osomajaponi~~~ infection, C57BU6 mice were infected with 50 cercariae of a zoophilic Taiwan strain of S. juponicum and sacrificed 3 to 12 weeks later. The cytokine mRNA expressions were detected with the reverse transcription-polymerase chain reaction and the cytokine protein productions were measured by the enzyme-linked immunosorbent assay. Six cytokines: IFN-y, IL2, R-4, R-5, IL-lo, and TNF-a were evaluated. The results showed that IFN-7 mRNA level increased significantly at 3-4 wk postinfection, and started to decrease at 5 wk, reaching the preinfection level at 6 wk. The IL-4 and IL-IO mRNA levels, however, began to rise at 7 wk and reached the peak at 8 and 9 wk, then declined at 9 and 12 wk. respectively. The TNF-a response was similar to IL-IO pattern The study on cytokine protein production showed that IFN-7 is the major immune response before the egg laying. On the other hand, Th2 cytokine IL-4 is the major response after the egg laying when the production of TIN-7 is suppressed. These findings indicated that the Thl response is involved in the early stage of infection (3-5 wk), while the Th2 response and TNF-a production are the major phenomena associated with the acute stage of infection (7-12 wk)
Parasitology International, 1998
Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-... more Third-stage larva of the bot-fly Gasterolthilus hoemorrtthidalis obtairled fr'ont thc stomach of-Egyptian equines were strrdiecl tracroscopically and by light microscope; apd for the first time by the scanning electrc.rtt nticroscope with particular reference to the anterior cephalic iegion and the nevrll, discovered sensory array of the mouth hooks, Tlre clcsign ot'thit array was cotttl.riu'c<l rvith that of larvae ol Gosterophiltts intestinalis and Gasterophilrts nasalls anrl ',vas ftrurtd to bc diffcrcnt tttairtly irr thc shape of the sensilla and the number of the angled ptates and that these fine criteria rnay be usecl to differentiate other larvac. Irr atltlitiort, ltrore dctailed clescription rvas added to the cephalic ancl caudal regions rvltich are ol'intl;ortant taxonomic value. GasteropSiline larvae are of vetcrinary anrl rttcdical irtlportance, rvitlt some httmatt creeping cutaneous nryiasis, ophtltalrnorrryiasis artd ottc reccttt rccord of intestinal myiasis.
For schistosonriasis, the development of long-lasting protective immunity through rraccination ma... more For schistosonriasis, the development of long-lasting protective immunity through rraccination may be the real solution to control the ciisease spread. The cegument which is the parasite outer coverinq serves as an interface between the host immune system and the parasite. Thus, antigens associated with the tegument have been a major focus for either vaccine development or immunodiagnostic reagents for schistosomiasis. In the present study pooled sera collected from Schistosome mansoni chronically infected patients was purified over a column made of 7-days schistosomula NP40 extract , then used to immunoscreen )" gt|l cDNA library of 7-days schistosomula , a number of cDNA clones were identified after three rounds of -.--immunoscreening and plaques purification. The isolated plaques were amplified rvith polymerase chain reaction (PCR) using I gtl I fonvard and reverse primers. The PCR products were cloned in PCRTNII plasmiC vector. Ail isolated clones were sequenced, the identified clone -s was found to encocie an alpha tubulin like gene. The
Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis i... more Sensitivity and specificity of vvet mount, culture and PCR in diagnosing Trichomonas vaginalis infection in females attending the Running title: Sensitivity and specificity of T. vaginalis diagnostic methods Abstract Background and Objectives: Trichomoniasis affects approximately 180 million women worldwide. It cau have an atypical or even asyrnptomatic course. Therefore, to accurately diagnose this disease, microbiological investigation is necessary. The aim of
Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) ... more Different Sc:histosoma mansoni antigens; adult worm antigen (SWAP) and lung-stage antigen (SLAP) together with ditferent cytokine adjuvants (lnterferon-gamma and Interleukin-4) were used to immunize mice against. S. nttutsoni.
Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma n... more Proteins that arc secretcd by or anchored on the surfacc of intramammalian stage of Schistosoma ntansoni are exposed to host tissucs and thus present potcnthl condldatc moleculcs for the developmcnt of nerv vaccine.
Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on ... more Toxoplasma gondii (T. gondii) is one of the most successful intracellular protozoan parasites on earth and highly prevalent in most warm-blooded vertebrates. There are no drugs that target the chronic cyst stage of this infection; therefore, development of an effective vaccine would be an important advance in disease control. Oligodeoxynucleotides (ODN) which contain immunostimulatory CG motifs (CpG ODN) can promote T-helper 1 (Th1) responses, an adjuvant activity that is desirable for vaccination against intracellular pathogen. In this study, we compare the immune responses of Toxoplasma susceptible C57BL/6 mice following intranasal and intramuscular vaccination with Toxoplasma lysate antigen (TLA) with or without CpG ODN as adjuvant. Immunized and control non-immunized mice were challenged with 85 cyst of the moderately virulent Beverley strain of T. gondii. Intranasal vaccination gave significantly a higher protection compared to other groups as indicated by prolonged survival and significantly reduced brain cyst burden (P< 0.01). Intranasal vaccination stimulated cellular immunity towards Th1 response characterized by significant INF-γ production (P<0.01). Furthermore, fecal IgA antibody levels as an indicator of mucosal immune responses were significantly higher (P<0.05) in intranasal vaccinated group before the challenge compared to all other groups. Intranasal vaccination was not able to upgrade the Th1 humoral arm. In contrast, intramus-cular vaccination enhanced humoral immunity towards a type Th1 pattern characterized by a significant increase of specific IgG and Ig2a. Our results suggest that intranasal administration of CpG/TLA would provide a stable, pronounced, and effective vaccine against toxoplasmosis through stimulation of Th1 cellular immunity and mucosal IgA.
As part of a search for good animal models for human schistosomiasis, two miniature pigs of the C... more As part of a search for good animal models for human schistosomiasis, two miniature pigs of the CLAWN strain (C-1, C-2) were inoculated percutaneously with 200 Schistosoma japonicum cercariae of the Chinese strain, and the subsequent infection was monitored parasitologically, pathologically and serologically. Egg excretion into feces began at 5 weeks post-infection (p.i.) and became pronounced from 8 weeks to 17 – 20 weeks p.i. The average number of eggs in 1 g feces of each pig at the peak period between 8 and 20 weeks were 288 and 277, respectively. C-1 and C-2 were killed and perfused at 27 and 47 weeks p.i. and adult worm numbers recovered were 35 and 15, respectively. C-2 had at least four pairs of viable mature worms but no detectable fecal eggs for a month before perfusion, suggesting that any produced eggs were not excreted into the feces during this period. Egg deposits associated with inflammatory reactions were observed by histological examination of the liver, spleen, pancreas, mesenteric lymph nodes, lung, and small intestine. This suggests that reduced fecal excretion of eggs into the feces did not correlate to reduced parasite numbers in the chronic phase of schistosomiasis. This is the first report showing the miniature pig to be a potential model for human S. japonicum infection.
Background: Cordylobia anthropophaga, one of the known furuncular myiasis-associated fly, has lon... more Background: Cordylobia anthropophaga, one of the known furuncular myiasis-associated fly, has long been limited to the Afro-tropical region. In Saudi Arabia, Southwest region, part of the Afro-tropical region, has been considered the sole endemic region of C. anthropophaga outside Africa. Aim: The aim of current study was to investigate suspected cases of myiasis recorded among 7 different children belonging to 3 different households in Makkah province, Midwest of Saudi Arabia. Methodology: The cases were referred to the Maternity and Children Hospital on 3 different occasions extended from September 2014 to February 2016. All cases were subjected to history taking and clinical examination. Suspected maggots were recovered from associated lesions and were subjected to thorough parasitological and taxonomic examination. Results: Clinical examination revealed suspected lesions of cutaneous myiasis in different parts of children bodies. History taking revealed no past history of wounds or travelling to Southwest region or tropical sub-Saharan Africa. Based on shape, size, cuticle spine pattern and the posterior spiracles, suspected maggots were identified as 3 rd instars of C. anthropophaga. Conclusion: To the best of our knowledge the current study is the first record of indigenously acquired cases of C. anthropophaga-induced furuncular myiasis in Midwest region of Saudi Arabia. This interesting finding might denote a remarkable change in the geographic epidemiology of C. anthropophaga with the first known incidence of autochthonous transmission pattern outside its conventional Afro-tropical endemic region. Indeed, further investigations are required to confirm this interesting record.