Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0017536 (giardiasis)
 1,714 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Giardia, a flagellated protozoan that infects the upper small intestine of its vertebrate host, is the most common parasitic protist responsible for diarrhea worldwide. Molecules released by the parasite, particularly excretory and secretory antigens, seemed to be associated with pathogenesis as well as with the expression of Giardia virulence. In the present work, we examined the effect of oral administration of Giardia intestinalis excretory and secretory antigens on systemic and local antibody response as well as on mucosal injuries in BALB/c mice. Significant titers of serum-specific immunoglobulin G1 (IgG1) and specific IgG2a were observed. Systemic and mucosal specific IgA antibodies were also recorded. A transient production of serum-specific IgE antibody and high total IgE levels were also detected, suggesting the presence in excretory and secretory proteins of factors promoting a specific IgE response. The sera of excretory and secretory antigen-treated mice recognized proteins of 50 and 58 kDa as well as electrophoretic bands of 15, 63, and 72 kDa that could support a proteinase activity. The in vitro exposure of G. intestinalis trophozoites to heat-inactivated sera from mice orally inoculated with excretory and secretory antigens induced a decrease of growth, revealing a complement-independent inhibitory activity of specific serum antibodies. Furthermore, histological evaluation performed on the small and large intestines revealed moderate to acute histological changes comparable to those observed in natural or experimental Giardia infection characterized by eosinophilic infiltration, hypercellularity, and enterocytic desquamation. The present results suggested that Giardia excretory and secretory antigens stimulate a preferential Th2 response, which is probably involved in the intestinal alterations associated with giardiasis.
Clin Diagn Lab Immunol 2004 Jan
PMID:Systemic and mucosal responses to oral administration of excretory and secretory antigens from Giardia intestinalis. 1471 63

Paneth cells are important contributors to the intestinal antimicrobial barrier through synthesis and release of antimicrobial peptides and proteins. Animal studies indicate that Paneth cell numbers, location and granule morphology are altered by infection and zinc status. We examined human tissue to determine whether Paneth cell numbers, distribution or granule morphology are altered in infective, inflammatory and nutritional disorders. Archival sections from infective disorders (giardiasis, cryptosporidiosis, HIV, helminth infection) were compared with active inflammatory conditions (coeliac, Crohn's and graft-versus-host diseases) and histologically normal tissues. A subset of tissues was studied by electron microscopy and TUNEL staining for apoptosis. Human defensin-5 (HD5) peptide and mRNA was analysed by immunohistochemistry, in situ hybridization and quantitative reverse transcription polymerase chain reaction. Sections from a tropical population cohort study were then analysed to determine the relationship of granule depletion to infection, nutritional status and plasma zinc concentration. In HIV-related cryptosporidiosis, but not other disorders, Paneth cells were reduced in number and markedly depleted of granules. Paneth cell granule depletion was associated with reduced HD5 immunoreactivity, but this was not due to apoptosis and there was no reduction in mRNA transcripts. In the tropical population studied, depletion of granules was associated with reduced body mass index, reduced plasma zinc levels and HIV infection. Paneth cell granules in human small intestine may be depleted in response to infective and nutritional stress. We postulate that this is one mechanism through which zinc status influences host susceptibility to intestinal infection.
Clin Exp Immunol 2004 Feb
PMID:Paneth cell granule depletion in the human small intestine under infective and nutritional stress. 1473 60

The efficacy of albendazole for the treatment of giardiasis has been indicated by previous in-vitro and in-vivo studies. In order to compare the therapeutic efficacy of albendazole and metronidazole, 107 Giardia-positive children (aged 3-15 years), diagnosed by three consecutive positive stool examinations, were enrolled in the study. Of these children, 52 were given a single daily dose of albendazole 10 mg/kg for 5 days, and 55 were given metronidazole 20 mg/kg daily in three doses for 7 days. Parasite eradication was achieved in 47 (90.4%) of 52 children treated with albendazole and 49 (89.1%) of 55 children treated with metronidazole (p > 0.05). These results suggest that albendazole is an effective treatment option for childhood giardiasis.
Clin Microbiol Infect 2004 Jun
PMID:Albendazole as an alternative therapeutic agent for childhood giardiasis in Turkey. 1519 80

All vertebrates produce gastric acid. Its main function is inactivation of ingested microorganisms. The majority of microbiological pathogens ingested never reaches the intestine because of the gastric barrier. Although gastric hypochlorhydria is fairly common due to atrophic gastritis, gastric surgery or use of inhibitors of gastric acid secretion, the resulting susceptibility to infection has not been studied extensively. Drug-induced blockade of acid secretion leads to gastrointestinal bacterial overgrowth; the clinical significance of this is still controversial. Gastric acidity is known to protect against non-typhoid salmonellosis and cholera and it is suspected that it protects against several parasitic diseases as giardiasis and strongyloides. There is a lack of studies focusing on the impact of the gastric acidic barrier on viral infections. Concerning prion infections only a single study has been performed, demonstrating a possible role of gastric acidity in the protection against foodborne prion disease in mice. The combination of malnutrition and hypochlorhydria may contribute to the high prevalence of gastrointestinal infections in developing countries. Further studies are needed to evaluate the clinical consequences of impaired gastric acidity with respect to susceptibility to infections.
Basic Clin Pharmacol Toxicol 2005 Feb
PMID:Gastric juice: a barrier against infectious diseases. 1567 70

More than 340 parasitic species infect more than 3 billion people worldwide with varying morbidity and mortality. The Tropics constitute the main reservoir of infection with the highest clinical impact, owing to favorable ecological factors. Acquisition of infection, clinical severity, and outcome of a parasitic disease depend on innate and acquired host immunity as well as the parasite's own immune response against the host when infection is established. Organ transplant recipients may acquire significant parasitic disease in 3 ways: transmission with the graft, de novo infection, or activation of dormant infection as a consequence of immunosuppression. Malaria, Trypanosoma, Toxoplasma, and Leishmania are the principal parasites that may be transmitted with bone marrow, kidney, or liver homografts, and microsporidia with xenotransplants. De novo infection with malaria and kala-azar may occur in immunocompromised travelers visiting in endemic areas, while immunocompromised natives are subject to superinfection with different strains of endemic parasites, reinfection with schistosomiasis, or rarely, with primary infections such as acanthamoeba. The list of parasites that may be reactivated in the immunocompromised host includes giardiasis, balantidiasis, strongyloidiasis, capillariasis, malaria, Chagas' disease, and kalaazar. The broad clinical syndromes of parasitic infection in transplant recipients include prolonged pyrexia, lower gastrointestinal symptoms, bronchopneumonia, and meningoencephalitis. Specific syndromes include the hematologic manifestations of malaria, myocarditis in Chagas' disease, acute renal failure in malaria and leishmaniasis, and the typical skin lesions of Chagas' and cutaneous leishmaniasis. Many antiparasitic drugs have the potential for gastrointestinal, hepatic, renal, and hematologic toxicity, and may interact with the metabolism of immunosuppressive agents. It is recommended that transplant clinicians have a high index of suspicion of parasitic infections as an important transmission threat, as well as a potential cause of significant posttransplant morbidity.
Exp Clin Transplant 2004 Dec
PMID:Parasitic infections in organ transplantation. 1585 39

A small proportion of coeliac disease (CD) patients fail to improve after a gluten-free diet (GFD) and may be considered as atypical regarding their outcome (refractory coeliac disease). The aim of this study is to diagnose and manage patients with CD who fail to improve after a GFD. Refractory coeliac disease (RCD) is a malabsorption syndrome defined by persisting villous atrophy with, usually, an increase of intraepithelial lymphocytes (IELs) in the small bowel in spite of a strict GFD and comprises a heterogenous group of diseases. Some of these diseases have to be excluded and can be treated by specific therapies like antibiotics in tropical sprue and giardiasis and immune globulin substitution in common variable immunodeficiency, while other malabsorption syndromes are less well defined and may require immunosuppressive therapy. Standardized treatment, however, has not been evaluated in such patients so far. In a subgroup of patients with RCD, an abnormal intraepithelial lymphocyte (IEL) population may be observed with the lack of surface expression of usual T-cell markers (CD3-CD8 and/or the T-cell receptor (TCR)) on IELs associated with T-cell clonality pattern suggest the presence of an early enteropathy-associated T-cell lymphoma (EATL) in a subgroup of patients with RCD. This hypothesis has been supported by studies, which revealed progression into overt intestinal T-cell lymphomas in a subgroup of RCD. Steroid treatment has been reported effective even in patients with underlying early EATL. However, long-term results are unsatisfactory in most of these patients with RCD and parenteral nutrition has to be applied in some of these cases. First results with more aggressive chemotherapies and use of cytokines are under way. Due to the difficulty of diagnostic and therapeutic regimens patients should be referred to tertiary centres for coeliac disease.
Best Pract Res Clin Gastroenterol 2005 Jun
PMID:Refractory coeliac disease. 1592 46

This study aims to determine the prevalence of protein-energy malnutrition and its association with soil-transmitted helminthiases in Orang Asli (Aborigine) children in Selangor, Malaysia. The results obtained from 368 children aged 2-15 years showed that the overall prevalence of mild and significant underweight was 32.1% and 56.5% respectively. The prevalence of mild stunting was 25.6% while another 61.3% had significant stunting. The overall prevalence of mild and significant wasting was 39.0% and 19.5% respectively. The overall prevalence of ascariasis, trichuriasis and hookworm infection were 61.9%, 98.2% and 37.0% respectively and of these 18.9%, 23.5% and 2.5% of the children had severe infection of the respective helminthes. The overall prevalence of giardiasis was 24.9%. The present study vividly shows that stunting and underweight are highly prevalent among Orang Asli children and therefore of concern in this community. In this population intestinal parasitic infections, especially severe trichuriasis and giardiasis, were identified as the main predictors of stunting and wasting respectively, in addition to age between 2 to 6 years.
Asia Pac J Clin Nutr 2005
PMID:Protein-energy malnutrition and soil-transmitted helminthiases among Orang Asli children in Selangor, Malaysia. 1592 39

A PCR assay targeting the tpi gene was developed to detect and to genotype Giardia lamblia in human feces. Our assay was specific and discriminated between G. lamblia assemblages A and B. G. lamblia cysts isolated from human feces were also analyzed with two previously described PCR-restriction fragment length polymorphism (RFLP) assays, which are based on the detection of tpi or gdh genes. These RFLP analyses distinguished groups I and II within assemblage A or groups III and IV within assemblage B. Among 26 fecal samples from patients with sporadic giardiasis diagnosed by hospital laboratories, the tpi gene was amplified from 25 (96%) with our PCR assay, whereas only 21 (81%) samples were positive when the gdh gene was targeted. Of the 25 positive samples, nine (36%) contained assemblage A and 16 (64%) contained assemblage B. Thus, RFLP analysis classified eight samples (32%) in assemblage A group II, eight (32%) in assemblage B group III, and five (20%) in assemblage B group IV. The group could not be specified for four samples. The tpi and gdh genes of G. lamblia assemblage B were amplified from 14 (93%) of 15 samples collected only from French soldiers coming back from the Ivory Coast. All of these contained assemblage B group III. The PCR method developed is sensitive, simple, and specific and shows that the tpi gene is well adapted for G. lamblia genotyping.
J Clin Microbiol 2005 Dec
PMID:Comparison of two target genes for detection and genotyping of Giardia lamblia in human feces by PCR and PCR-restriction fragment length polymorphism. 1633 79

The aim of this study was to evaluate the performance of the CORIS Giardia-Strip test (CORIS Bioconcept, Gembloux, Belgium) as a rapid initial method for the routine diagnosis of giardiasis. Compared to a commercial ELISA-coproantigen test (ProSpect Giardia-ELISA-microplate assay; Remel, Lenexa, KS, USA), the commercial strip test had a sensitivity of 58%, a specificity of 99%, a positive predictive value of 93% and a negative predictive value of 93% (n=158). These results are comparable to those obtained using microscopy of direct wet-mounted stool. Since the CORIS Giardia-Strip test is simpler to perform, it can replace direct wet-mounted stool microscopy for the rapid diagnosis of giardiasis; however, its sensitivity is inferior to that of other immunochromatographic antigen detection tests and fresh stool samples are required for its use. Nevertheless, the results suggest that a positive CORIS Giardia-Strip test outcome does not need confirmation, while samples with negative results should be re-examined using another, more sensitive, test.
Eur J Clin Microbiol Infect Dis 2006 Feb
PMID:Evaluation of the immunochromatographic CORIS Giardia-Strip test for rapid diagnosis of Giardia lamblia. 1644 62

Stool samples from patients with abdominal symptoms were used to evaluate different copro-diagnostic assays for the detection of Giardia and Cryptosporidium. Results from microscopical examination following conventional stool concentration and direct fluorescent-antibody methods were compared with various commercially available immunochromatographic and enzyme immunoassays. Of 220 samples, 45 were positive for Giardia and 17 for Cryptosporidium. For Giardia, the sensitivities obtained by Ridascreen Giardia, Rida Quick Giardia, Rida Quick Combi and Giardia-Strip were 82%, 80%, 80% and 44%, respectively. For Cryptosporidium, the sensitivities obtained by Rida Quick Cryptosporidium, Ridascreen Cryptosporidium, Rida Quick Combi and Cryptosporidium-Strip were 88%, 82%, 82% and 75%, respectively. The specificity of all tests was > or = 98%. Other intestinal parasites were present in 68 samples, but cross-reactions with other protozoan or helminthic parasites were not observed. Overall, the copro-antigen assays were less time-consuming and easier to perform, but were less sensitive than conventional microscopical methods. Thus, these tests might be a useful addition to, but not a substitute for microscopical methods in the diagnosis of travel-associated giardiasis and cryptosporidiosis.
Clin Microbiol Infect 2006 Jul
PMID:Evaluation of seven commercial antigen detection tests for Giardia and Cryptosporidium in stool samples. 1677 62


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