Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| isolation of cryptosporidium parvum and cyclospora cayetanensis from vegetables collected in markets of an endemic region in peru. | cryptosporidium parvum and cyclospora cayetanensis are protozoan pathogens that cause prolonged diarrhea in both immunocompetent and immunocompromised hosts. cryptosporidium parvum can be transmitted via the fecal-oral route, while the exact mechanisms of transmission of cyclospora cayetanensis have not been fully determined. humans appear to be the sole host for the latter and a distinct seasonality has been observed in endemic areas around the world. samples of vegetables were collected at sev ... | 1997 | 9430527 |
| sexual and asexual development of cryptosporidium parvum in five oocyst- or sporozoite-infected human enterocytic cell lines. | the human enterocytic cell lines caco-2, ht29, hct8 and the caco-2 clones tc7 and pf11 were studied for their ability to support cryptosporidium parvum development. following the addition in cultures of either oocysts or excysted sporozoites, immunofluorescent and transmission electron microscopy revealed the presence of all stages of the parasite life cycle by both procedures, and no difference in the ratio of infected cells was found among cell lines. more oocysts were seen in cell monolayers ... | 1997 | 9435129 |
| [chronic enteropathy of unknown etiology in patients with aids. an analysis of 40 cases]. | data about the etiology of chronic enteropathy in aids patients are scarce and are very dependent upon the geographical area. the aim of this study was to detect microorganisms potentially associated with chronic enteropathy in aids patients with diarrhoea for more than one month, and initial negative routine stool bacterial cultures and examinations for ova and parasites. the degrees of associated intestinal malabsorption and immunodeficiency were also analysed. | 1997 | 9441179 |
| cryptosporidium parvum--propagation of oocyst in neonatal calves. | shedding of cryptosporidium parvum oocyst was studied in experimentally infected jersey-sindhi cross bred calves. three 7 day old bull calves housed in isolation were orally infected with 10(8) oocysts of cryptosporidium parvum. the prepatent and patent period of the experimental infection were 5 and 4 days respectively. maximum oocyst output [2 x 10(5) oocyst per gram (opg) was observed on the 7th day post inoculation (pi). the mean total oocyst output was 2.5 x 10(7). diarrhoea started on the ... | 1997 | 9444857 |
| cryptosporidium parvum biliary tract infection in adult immunocompetent and immunosuppressed mice. | biliary tract infection by cryptosporidium parvum is a frequent complication of intestinal cryptosporidiosis in immunosuppressed patients. although biliary tract infection can be produced in immunosuppressed models as a late complication of intestinal infection, there is no infection model in immunocompetent animals. a murine model of biliary tract cryptosporidiosis was developed by direct intra-gall bladder injection of c. parvum oocysts. in adult immunocompetent mice, intracellular parasitic s ... | 1998 | 9449952 |
| enzyme-linked immunoelectrotransfer blot analysis of a cryptosporidiosis outbreak on a united states coast guard cutter. | symptoms consistent with an outbreak of cryptosporidiosis (diarrhea, vomiting, nausea, and abdominal cramps) occurred on a u.s. coast guard cutter within 0-18 days after the cutter filled its tanks with milwaukee, wisconsin city water in march 1993. at three-weeks postdocking (pd), the suspected water was removed, and serum samples and stool specimens were collected from 47 of the 58 crew members, as well as questionnaire data on their water consumption and symptoms aboard the cutter. at 10-week ... | 1998 | 9452301 |
| susceptibility and serologic response of healthy adults to reinfection with cryptosporidium parvum. | healthy adults are susceptible to infection with small numbers of cryptosporidium parvum oocysts, resulting in self-limited infection. we investigated if infection of humans with c. parvum is protective 1 year after primary exposure. at 1 year after a primary challenge with 30 to 10(6) oocysts, 19 healthy immunocompetent adults were rechallenged with 500 oocysts and monitored for the development of infection and/or illness. oocyst excretion was quantitated by direct immunofluorescence with a c. ... | 1998 | 9453592 |
| requirement of cd40-cd40 ligand interaction for elimination of cryptosporidium parvum from mice. | mice with disrupted genes for cd40 and cd40 ligand (cd40l) are unable to clear infection with cryptosporidium parvum and develop cholangitis. parasites are present in the gut, gall bladder, and biliary tree, and biliary epithelial cells express cd40 on the cell surface. scid mice infected with c. parvum for >1 month can clear the infection after reconstitution with spleen cells from cd40, but not cd40l, knockout mice. in an in vitro model, c. parvum-infected hepg2 cells were triggered to apoptos ... | 1998 | 9453615 |
| treatment of hiv-1-associated microsporidiosis and cryptosporidiosis with combination antiretroviral therapy. | enterocytozoon bieneusi and cryptosporidium parvum cause chronic antimicrobial-resistant gastrointestinal infections in hiv-1-infected individuals. hiv-1 reverse transcriptase inhibitors delay the onset of opportunistic infections, but are not known to reverse established infections. hiv-1 protease inhibitors are more effective across a broader range of hiv-1-infected immune cells. combination antiretroviral therapy that includes a protease inhibitor could improve immunity to e bieneusi and c pa ... | 1998 | 9457096 |
| possible effectiveness of clarithromycin and rifabutin for cryptosporidiosis chemoprophylaxis in hiv disease. hiv outpatient study (hops) investigators. | cryptosporidium parvum infection, a common cause of diarrhea in persons infected with the human immunodeficiency virus (hiv), is difficult to treat or prevent. | 1998 | 9459473 |
| prevalence of infection with cryptosporidium parvum and cyclospora cayetanensis among international travellers. | cryptosporidium parvum and cyclospora cayetanensis are recognised as possible pathogens of traveller's diarrhoea. | 1997 | 9462213 |
| enteropathy in zambians with hiv related diarrhoea: regression modelling of potential determinants of mucosal damage. | aids is characterised by small intestinal mucosal damage, but its aetiopathogenesis is poorly understood. enteric infections in africa differ from those in northern countries, where protozoan infections have been associated with severe enteropathy in aids patients. | 1997 | 9462215 |
| recovery of waterborne cryptosporidium parvum oocysts by freshwater benthic clams (corbicula fluminea). | asian freshwater clams, corbicula fluminea, exposed for 24 h to 38 liters of water contaminated with infectious cryptosporidium parvum oocysts (1.00 x 10(6) oocysts/liter; approximately 1.9 x 10(5) oocysts/clam) were examined (hemolymph, gills, gastrointestinal [gi] tract, and feces) on days 1, 2, 3, 7, and 14 postexposure (pe). no oocysts were detected in the water 24 h after the contamination event. the percentage of oocyst-containing clams varied from 20 to 100%, depending on the type of tiss ... | 1998 | 9464376 |
| nosocomial transmission of cryptosporidium in a veterinary hospital. | an outbreak of cryptosporidiosis occurred at a veterinary hospital, involving multiple species, including humans. the index case was an infected dairy calf that presented with diarrhea. several other cases of cryptosporidial diarrhea subsequently developed during a 1-month period. the key features of this outbreak were the multiple species affected, the increased morbidity in immunocompromised neonates, and the failure of implemented control measures to contain the disease. | 1997 | 9470158 |
| ribosomal rna gene organization in cryptosporidium parvum. | the cytoplasmic ribosomal rna (rrna) genes of the apicomplexan protozoan parasite cryptosporidium parvum have been analyzed with respect to size, copy number, organization and structure. the small and large subunit rrnas are 1.7 and 3.6 kb, respectively. a 151 bp putative 5.8s rrna gene was identified. the rdna unit is 5' small subunit rrna internal transcribed spacer 1-5.8s rrna-internal transcribed spacer 2-large subunit rrna 3'. there are five copies of the rdna unit per haploid genome and th ... | 1997 | 9476794 |
| [the interrelationships of the coccidian cryptosporidium parvum (apicomplexa: sporozoa) with the cells of the immune system in the mammalian host]. | by means of an electron microscopic study of the intestine in young rats infected with cryptosporidium parvum we observed a mass migration of immunocompetent cells of the host (eosinophils, neutrophils and macrophages) into the lumen of intestine. some lymphocytes were also observed. immunocompetent cells (except lymphocytes) included inside phagosomes with different endogenic states of c. parvum. macrophages with typical extracytoplasmic parasitophorous vacuoles formed by c. parvum were also ob ... | 1997 | 9479380 |
| [emerging infectious disease--cryptosporidiosis]. | 1997 | 9480310 | |
| [the prevalence of cryptosporidia among agricultural animals in azerbaijan]. | in the paper are presented the data on revealement of cryptosporidian oocysts (apicomplexa, sporozoa) in feces of cattle, swine and sheep of different ages and results of the experimental infection of laboratory animals (rats, mice, rabbits, coypus) with the oocysts detected as well. the latters were attributed to cryptosporidium parvum species. the analysis of the size characteristic in the isolates of naturally and artificially infected hosts has shown that the oocysts dimensions might vary bo ... | 1996 | 9480451 |
| hydrops-like cholecystitis due to cryptosporidiosis in an hiv-infected child. | 1998 | 9481642 | |
| cryptosporidium in tap water: comparison of predicted risks with observed levels of disease. | waterborne transmission of cryptosporidium parvum is well-established as a source in outbreaks of cryptosporidiosis; however, the role of tap water in endemic disease is unclear. the authors applied a risk assessment approach incorporating uncertainty analysis to examine the potential role of tap water in the transmission of endemic c. parvum infection. the model had two components: exposure-infection, to relate low-dose exposure to infection; and infection-outcome, to include the probabilities ... | 1998 | 9482504 |
| cryptosporidium parvum development in the bs-c-1 cell line. | cryptosporidium parvum is a worldwide parasitic protozoon capable of causing life-threatening disease in immunocompromised patients. in vitro cultivation of c. parvum has been under investigation for development of a well-defined in vitro model for c. parvum infectivity assay. this is the first report of c. parvum completing its life cycle in bs-c-1, an african green monkey kidney cell line. both sodium hypochlorite-stimulated oocysts and purified sporozoites were able to initiate infection that ... | 1998 | 9488330 |
| local ileal cytokine responses in cattle during a primary infection with cryptosporidium parvum. | in the present study, localized changes in cytokine transcription profiles were examined in neonatal calves following a primary infection with cryptosporidium parvum, using competitive reverse transcriptase polymerase chain reaction (rt-pcr). total rna was prepared from ileocecal lymph nodes (ln), lamina propria lymphocytes (lpl), and intraepithelial lymphocytes (iel) isolated from neonatal calves 7 days after c. parvum infection. competitive rt-pcr performed on cdna samples containing internal ... | 1998 | 9488349 |
| fatal cryptosporidiosis in a juvenile captive african hedgehog (ateletrix albiventris). | fatal intestinal cryptosporidiosis of unknown source and unexplained epizootiology is reported in a neonatal captive african hedgehog (ateletrinx albiventris) and for the first time in a hedgehog species. the infection, confined to ileum, jejunum, and colon, was extremely severe in the lower jejunum where over 75% of the epithelial cells harbored the pathogen. the ileum and the jejunum displayed moderate and severe villus atrophy and mucosal hyperplasia. lamina propria and mucosa were infiltrate ... | 1998 | 9488362 |
| development and application of an improved semiquantitative technique for detecting low-level cryptosporidium parvum infections in mouse tissue using polymerase chain reaction. | an improved semiquantitative technique was developed for measuring low infectious doses of cryptosporidium parvum in neonatal mice using polymerase chain reaction (pcr). separate litters of neonatal mice were inoculated with 0, 10(2), 10(3), or 10(4) c. parvum oocysts and killed 96 hr postinfection. a segment of the ileum or the entire whole intestine was then removed from subgroups of mice in each litter and total dna was extracted using standard procedures. by employing a cp15/60-based semiqua ... | 1998 | 9488364 |
| enteric beta-defensin: molecular cloning and characterization of a gene with inducible intestinal epithelial cell expression associated with cryptosporidium parvum infection. | a growing body of evidence suggests that endogenous antibiotics contribute to the innate defense of mammalian mucosal surfaces. in the cow, beta-defensins constitute a large family of antibiotic peptides whose members have been previously isolated from the respiratory and oral mucosa, as well as circulating phagocytic cells. a novel bovine genomic clone with beta-defensin-related sequence [corrected] related to those of these alpha-defensins was isolated and characterized. the corresponding cdna ... | 1998 | 9488394 |
| strategies for the control of cryptosporidium parvum infection in calves. | cryptosporidium parvum is a protozoan parasite that is now recognized as one of the leading causes of diarrhea in young calves. to date, there are no drugs or preventive measures available for the control of this disease. we have developed an oral vaccine that, when given to calves at birth, protects against experimental challenge with c. parvum. however, when field tested on a large dairy operation with heavy endemic c. parvum infection, the vaccine failed to provide protection. the difference ... | 1998 | 9493106 |
| molecular analysis of a p-type atpase from cryptosporidium parvum. | eukaryotic p-type atpases use energy to drive the transport of cations across membranes. a complete p-atpase gene (cpatpase1) has been isolated from cryptosporidium parvum, one of the opportunistic pathogens in aids patients. the complete gene encodes 1528 amino acids, predicting a protein of 169 kda. a hydropathy profile of the protein suggested there are eight transmembrane domains (tm). expression of the gene was confirmed both by northern blot analysis and rt-pcr. a fragment of the gene has ... | 1997 | 9497052 |
| public health hazards from small ruminant meat products in europe. | foodborne diseases, in particular those related to meat and meat products, have recently become a matter of great public concern. sheep and goat meat can transmit infections and diseases either through handling during preparation procedures or as a result of ingestion by the consumer. the authors highlight the second route of contamination in relation to meat and meat products from small ruminants in european countries. among the most important diseases transmitted by mutton and goat meat, toxop ... | 1997 | 9501355 |
| survival of infectious cryptosporidium parvum oocysts in seawater and eastern oysters (crassostrea virginica) in the chesapeake bay. | oocysts of cryptosporidium parvum placed in artificial seawater at salinities of 10, 20, and 30 ppt at 10 degrees c and at 10 ppt at 20 degrees c were infectious after 12 weeks. those placed in seawater at 20 ppt and 30 ppt at 20 degrees c were infectious for 8 and 4 weeks, respectively. these findings suggested that oocysts could survive in estuarine waters long enough to be removed by filter feeders such as oysters. thereafter, 30 eastern oysters, crassostrea virginica, were collected with a d ... | 1998 | 9501446 |
| [a clinical and biological study of parasitic and fungal diarrhea in immunosuppressed patients in an urban and suburban area of yaoundé]. | we studied 66 cases of intestinal mycosis and parasitosis in patients infected with the human immunodeficiency virus with chronic diarrhea. all subjects were from the yaounde urban area and were followed between february and december 1996. they were recruited from 3 hospitals in the center of yaounde and were aged between 2 and 52 years. there was weight loss in 80.3% and severe dehydration in 72.3% of cases. feces consisted mostly of watery stools similar to those of cholera patients (50% of ca ... | 1997 | 9503491 |
| cryptosporidium parvum infection in bovine neonates: dynamic clinical, parasitic and immunologic patterns. | twenty-six experimentally infected calves were monitored daily for oocyst excretion. all began excreting oocysts 3-6 days p.i. most calves (n = 23) excreted oocysts for 6-9 days, with a daily range from 4 x 10(2) to 4.15 x 10(7) oocysts g(-1) of faeces. over half the calves excreted peak numbers of oocysts 6-8 days p.i. diarrhoea, observed intermittently beginning as early as day 3 p.i., lasted 4-16 days and varied greatly in severity from calf to calf. in a second study, nine of 18 calves were ... | 1998 | 9504334 |
| epidemiological study of cryptosporidium parvum antibodies [corrected] in sera of persons from germany. | in a seroprevalence study including 495 sera from persons of all age-groups, the presence of anti-cryptosporidium parvum antibodies was evaluated in an enzyme immunoassay. despite the fact that c. parvum is only found in approximately 2% of patients with diarrhea in germany, specific antibodies could be detected in 15.4% of all samples. this figure indicates that a substantial proportion of the german population has been confronted with this parasite and it raises the question of whether c. parv ... | 1998 | 9505172 |
| bovine fallopian tube epithelial cells, adult c57bl/6 mice, and non-neonatal pigs as models for cryptosporidiosis. | 1997 | 9508447 | |
| in vitro cultivation of cryptosporidium parvum in the non-adherent human monocytic thp-1 cell line. | this study shows that the human monocytic cell line thp-1 supports the growth of c. parvum. immunofluorescence controls showed that only scarce oocysts remained after infection and disappeared within the first 24 h of culture. a continuous asexual life cycle proceeded throughout the experiments, with at least 15-d cultures. this model provides a useful tool for studies on the biology of c. parvum in cells involved in its transport in immunocompromised host. | 1997 | 9508448 |
| physiopathologic and therapeutic studies in in vitro and in vivo models of cryptosporidium parvum infection. | 1997 | 9508450 | |
| in vitro interactions of human blood and intestinal intraepithelial lymphocytes with cryptosporidium parvum and c. parvum permissive enterocytic cell lines. | 1997 | 9508452 | |
| evaluation of viability and infectivity of waterborne cryptosporidium parvum oocysts. | 1997 | 9508453 | |
| cryptosporidium parvum gp900, a unique invasion protein. | 1997 | 9508468 | |
| cryptosporidiosis in persons with hiv infection. | cryptosporidium parvum is an ubiquitous protozoan parasite that is a major cause of diarrhoea in individuals infected with human immunodeficiency virus. the hallmarks of infection include profuse watery diarrhoea which may become chronic in the severely immunosuppressed individual. no uniformly effective therapy exists. current treatment relies upon a trial of anti-retroviral and specific anti-cryptosporidial medications, adequate fluid and nutritional support, and anti-motility agents. | 1997 | 9519184 |
| synthesis and evaluation of dinitroanilines for treatment of cryptosporidiosis. | the efficacy of a series of dinitroaniline herbicide derivatives for the treatment of cryptosporidium parvum infections has been studied. the lead compounds oryzalin (compound 1) and trifluralin (compound 2) have low water solubility (<3 ppm) which was alleged to be a major contributor to their poor pharmacokinetic availability. derivatives of compounds 1 and 2 were synthesized. in these derivatives the functionality at the c-1 amine position or the c-4 position was substituted with groups with ... | 1998 | 9527782 |
| human intestinal epithelial cells respond to cryptosporidium parvum infection with increased prostaglandin h synthase 2 expression and prostaglandin e2 and f2alpha production. | cryptosporidium parvum is an important cause of diarrhea in humans and several animal species. prostaglandins play a central role in regulating intestinal fluid secretion in animal models of cryptosporidiosis, but their cellular sources and mechanisms of induction are unclear. here, we show that c. parvum infection directly activates prostaglandin h synthase 2 expression and prostaglandin e2 and f2alpha production in human intestinal epithelial cells. | 1998 | 9529115 |
| in-vitro activities of paromomycin and lasalocid evaluated in combination against cryptosporidium parvum. | using a chemiluminescence immunoassay, paromomycin and lasalocid were shown to inhibit cryptosporidium parvum growth in madin-darby canine kidney cells in a concentration-dependent manner. the median effective concentrations (ec50s) for paromomycin and lasalocid were 1184 mg/l and 0.4 mg/l, respectively. neither drug was cytotoxic to host cells at concentrations up to five times their ec50s. drug combination studies were conducted and the resulting data were analysed by the median-effect princip ... | 1998 | 9533476 |
| effects of an allicin-based product on cryptosporidiosis in neonatal calves. | to evaluate effectiveness of an allicin-based product in neonatal calves inoculated with cryptosporidium parvum. | 1998 | 9540869 |
| comparison of pcr and microscopy for detection of cryptosporidium parvum in human fecal specimens: clinical trial. | pcr technology offers alternatives to conventional diagnosis of cryptosporidium for both clinical and environmental samples. we compared microscopic examination by a conventional acid-fast staining procedure with a recently developed pcr test that can not only detect cryptosporidium but is also able to differentiate between what appear to be host-adapted genotypes of the parasite. examinations were performed on 511 stool specimens referred for screening on the basis of diarrhea. pcr detected a t ... | 1998 | 9542924 |
| dna sequence similarity between california isolates of cryptosporidium parvum. | we evaluated whether nucleic acid amplification with primers specific for cryptosporidium parvum followed by automated dna sequence analysis of the pcr amplicons could differentiate between california isolates of c. parvum obtained from livestock, humans, and feral pigs. almost complete sequence identity existed among the livestock isolates and between the livestock and human isolates. dna sequences from feral pig isolates differed from those from livestock and humans by 1.0 to 1.2%. the referen ... | 1998 | 9546195 |
| natural history and biology of cryptosporidium parvum. | the taxonomy of the genus cryptosporidium remains ambiguous, because the current criteria for speciation are insufficient to validate the 6-8 named species. cross-transmission experiments have shown varying and conflicting results, and the limited genetic data available do not necessarily support currently proposed species designations. the reasons for this ambiguity lie with the ubiquitous nature of cryptosporidium, probably infecting all vertebrates and variety of tissues therein, and the abse ... | 1998 | 9554069 |
| innate and cell-mediated immune responses to cryptosporidium parvum. | cryptosporidium parvum has gained much attention as a major cause of diarrhea in the world. knowledge of the host immune mechanisms responsible for the clearance of this parasite from the gastrointestinal tract may prove to be vital for successful therapeutic treatment of cryptosporidiosis, particularly in the immunodeficient host. this chapter focuses on the innate and cell-mediated immune mechanisms associated with resistance to and resolution of a c. parvum infection. much of the work in thes ... | 1998 | 9554071 |
| antibody-based immunotherapy of cryptosporidiosis. | passive antibody immunotherapy (pai) for cryptosporidiosis is a treatment strategy that has been actively pursued in laboratory studies and early-stage clinical studies for the last decade. several experimental approaches have been initiated, including use of bovine colostrum and colostral antibodies (hyperimmune and natural), monoclonal antibodies, chicken egg yolk antibodies, and even orally administered human plasma antibodies. most studies have employed oral administration to treat or preven ... | 1998 | 9554072 |
| cryptosporidium: molecular basis of host-parasite interaction. | host-parasite interactions occur at a number of stages during the process of infection with cryptosporidium. until recently, very little was known about the molecular basis of these interactions or of specific parasite and host molecules involved in them. within the past decade significant advances have been made in our understanding of cryptosporidium host-parasite interactions and in identifying molecules involved in them. however, with most interactions the story is far from complete and a nu ... | 1998 | 9554073 |
| cryptosporidiosis: laboratory investigations and chemotherapy. | much progress has been achieved in the last decade in terms of development of laboratory techniques, reagents and in vivo models. they have undoubtedly contributed to better and more accurate investigations. despite a concerted effort by many investigators, however, breakthroughs have been minimal. the development of adequate in vitro and in vivo techniques for drug screening, and the intensified and systematic screening, has so far not resulted in the discovery of an effective therapy. the reas ... | 1998 | 9554074 |
| genetic heterogeneity and pcr detection of cryptosporidium parvum. | a variety of methods have been applied to the study of genotypic and phenotypic polymorphism in cryptosporidium parvum. results from these studies have consistently shown the existence of different genotypes and phenotypes within the species. a long-term goal of this work is the identification of markers for virulence in humans and animals and the elucidation of transmission cycles of c. parvum. achievement of these goals will depend on the identification of highly polymorphic loci. of particula ... | 1998 | 9554075 |
| cyclosporin analogs inhibit in vitro growth of cryptosporidium parvum. | cyclosporine and nonimmunosuppressive cyclosporin (cs) analogs were demonstrated to be potent inhibitors of the growth of the intracellular parasite cryptosporidium parvum in short-term (48-h) in vitro cultures. fifty-percent inhibitory concentrations (ic50s) were 0.4 microm for sdz 033-243, 1.0 microm for sdz psc-833, and 1.5 microm for cyclosporine. two other analogs were less effective than cyclosporine: the ic50 of sdz 205-549 was 5 microm, and that of sdz 209-313 was 7 microm. these were mu ... | 1998 | 9559794 |
| therapeutic efficacy of hyperimmune bovine colostrum treatment against clinical and subclinical cryptosporidium serpentis infections in captive snakes. | therapy based on the protective passive immunity of hyperimmune bovine colostrum (hbc) (raised against cryptosporidium parvum in dairy cows immunized during gestation) was tested for heterologous efficacy in subclinical and clinical infections of 12 captive snakes with c. serpentis. six gastric hbc treatments of 1% snake weight at 1-week intervals each, have histologically cleared c. serpentis in three subclinically infected snakes, and regressed gastric histopathological changes in one of these ... | 1998 | 9561700 |
| differentiation between human and animal isolates of cryptosporidium parvum using molecular and biological markers. | isolates of cryptosporidium parvum obtained from infected humans, calves and lambs were typed using arbitrary primed polymerase chain reaction (ap-pcr) and isoenzyme electrophoresis. all animal isolates tested (n = 17) showed similar profiles in ap-pcr and isoenzyme typing. in ap-pcr assays, 9 out of 15 human isolates showed a distinct "human" profile while the remaining 6 isolates showed the "animal" profile. in isoenzyme typing, 5 human isolates which had shown "human" profiles in ap-pcr demon ... | 1998 | 9569095 |
| cryptosporidiosis in young alpacas. | 1998 | 9569489 | |
| lack of activity of an association of detergent and germicidal agents on the infectivity of cryptosporidium parvum oocysts. | 1998 | 9570672 | |
| sensitive and rapid detection of viable giardia cysts and cryptosporidium parvum oocysts in large-volume water samples with wound fiberglass cartridge filters and reverse transcription-pcr. | we recently described a reverse transcription-pcr (rt-pcr) for detecting low numbers of viable cryptosporidium parvum oocysts spiked into clarified environmental water concentrates. we have now modified the assay for direct analysis of primary sample concentrates with simultaneous detection of viable c. parvum oocysts, giardia cysts, and a novel type of internal positive control (ipc). the ipc was designed to assess both efficiency of mrna isolation and potential rt-pcr inhibition. sensitivity t ... | 1998 | 9572946 |
| differentiation of cryptosporidium parvum isolates by a simplified randomly amplified polymorphic dna technique. | genomic dna was isolated from cryptosporidium parvum oocysts by a specific immunomagnetic separation-in vitro excystation procedure and subjected to randomly amplified polymorphic dna analysis using sequence-independent primers. an estuary c. parvum isolate was easily differentiated from several bovine isolates, while five bovine isolates of the same origin were indistinguishable from each other. | 1998 | 9572980 |
| cryptosporidium parvum infection of human intestinal xenografts in scid mice induces production of human tumor necrosis factor alpha and interleukin-8. | the protozoan parasite cryptosporidium parvum invades intestinal epithelial cells and can cause life-threatening diarrhea in immunocompromised individuals. despite the clinical importance of this organism, much remains to be learned about the pathogenesis of c. parvum-induced diarrhea. to explore the role of the intestinal inflammatory response in c. parvum disease, using c. parvum oocysts we infected human intestinal xenografts in severe combined immunodeficient (scid) mice. seven days after in ... | 1998 | 9573136 |
| intestinal parasitic infections in human immunodeficiency virus (hiv)-positive and hiv-negative individuals in san pedro sula, honduras. | honduras has at least five-times more human immunodeficiency virus (hiv)-infected individuals than any other country in central america. the relationship between hiv status and the presence of intestinal parasites in this part of the world is unknown. this study presents the results from a prospective, comparative study for the presence of parasites in 52 hiv-positive and 48 hiv-negative persons in san pedro sula, honduras. infection with hiv was determined by microagglutination and confirmed by ... | 1998 | 9574787 |
| molecular cloning and expression analysis of a cryptosporidium parvum gene encoding a new member of the thrombospondin family. | the apicomplexan parasite cryptosporidium parvum invades and multiplies primarily in the brush border cells of the intestinal mucosa causing in aids patients a severe diarrhoea that represents a significant contributing factor leading to death. morphological analysis indicates that the invasion machinery of c. parvum is similar to the apical complex of other parasites of the phylum apicomplexa. we provide here evidence indicating that c. parvum also shares with these parasites a molecule crucial ... | 1998 | 9574918 |
| failure to differentiate cryptosporidium parvum from c. meleagridis based on pcr amplification of eight dna sequences. | in order to determine the specificities of pcr-based assays used for detecting cryptosporidium parvum dna, eight pairs of previously described pcr primers targeting six distinct regions of the cryptosporidium genome were evaluated for the detection of c. parvum, the agent of human cryptosporidiosis, and c. muris, c. baileyi, and c. meleagridis, three cryptosporidium species that infect birds or mammals but are not considered to be human pathogens. the four cryptosporidium species were divided in ... | 1998 | 9575132 |
| hydrogen peroxide gas plasma sterilization is effective against cryptosporidium parvum oocysts. | the aim of this work was to evaluate in an immunosuppressed rat cryptosporidiosis model a new method that combines vacuum and low-temperature hydrogen peroxide gas plasma for sterilization of endoscopic material contaminated by cryptosporidium parvum. rats were challenged with oocysts either air-dried or air-dried and treated with vacuum alone or associated with gas plasma. no rat was found infected after gas plasma exposure of oocysts, whereas vacuum or air-drying alone resulted only in a decre ... | 1998 | 9584807 |
| direct isolation of dna from patient stools for polymerase chain reaction detection of cryptosporidium parvum. | although polymerase chain reaction (pcr) can sensitively detect parasitic or other infections, its use with fecal samples is extremely limited, primarily because of the presence of substances that inhibit dna extension. here an improved protocol is reported for directly isolating dna from aged or fresh formalin-fixed stools, which can then be used to detect cryptosporidium parvum by nested pcr. this method is highly reproducible, sensitive, and specific. it detects <1 pg of c. parvum dna in huma ... | 1998 | 9593044 |
| hypoxanthine, guanine, xanthine phosphoribosyltransferase activity in cryptosporidium parvum. | all parasitic protozoa examined to date are incapable of de novo synthesis of purine nucleotides and rely on salvage mechanisms for survival. we have identified hypoxanthine, guanine, xanthine phosphoribosyl-transferase activities in crude cell-free extracts of cryptosporidium sporulated oocysts utilizing radiolabeled substrates. guanine, hypoxanthine, and xanthine were converted to their corresponding mononucleotides with specific activities of 346, 280, and 108 nmol/min/mg protein, respectivel ... | 1998 | 9603483 |
| randomly amplified polymorphic dna pcr analysis of bovine cryptosporidium parvum strains isolated from the watershed of the red river of the north. | cryptosporidium parvum is a protozoan parasite that causes the disease cryptosporidiosis in a variety of mammals, including neonatal calves and humans. millions of oocysts are shed during acute cryptosporidiosis, and zoonotic transmission is inferred, though not proven, to be a general phenomenon. very little is known about the degree of strain variation exhibited by bovine and human isolates, though such knowledge would enable the amount of bovine-to-human transmission to be more precisely anal ... | 1998 | 9603845 |
| method detection limits of pcr and immunofluorescence assay for cryptosporidium parvum in soil. | we determined and compared the method detection limits (mdlalpha) of a pcr and an immunofluorescence assay (ifa) for detection of cryptosporidium parvum oocysts in soils. based on the mdlalpha and the quantitative nature and stability of the ifa, pcr analysis is not a useful screening step for soil studies of oocyst transport. | 1998 | 9603851 |
| attachment of cryptosporidium parvum sporozoites to human intestinal epithelial cells. | an enzyme-linked immunosorbent assay-based attachment model using the human intestinal cell line caco-2a was developed to study attachment of cryptosporidium parvum sporozoites in vitro and to assess potential inhibitors of sporozoite binding. in this system, attachment was related to sporozoite dose, incubation time, and host cell differentiation status. polyclonal antibodies to c. parvum as well as glycoprotein inhibitors of a sporozoite lectin reduced attachment. this model will be a valuable ... | 1998 | 9632617 |
| high-temperature inducible cell-free transcription and replication of double-stranded rnas within the parasitic protozoan cryptosporidium parvum. | sporozoites of the protozoan parasite, cryptosporidium parvum, were found to contain free, full-size plus strands transcribed from two extrachromosomal, cytoplasmic, virus-like double-stranded rnas (dsrnas). cell-free transcription and replication of both dsrnas were observed in crude sporozoite lysates. rna polymerase activity was found to be dependent upon addition of mg2+ or mn2+, as well as the four ribonucleoside triphosphates, and was insensitive to inhibitors of cellular dna-dependent rna ... | 1998 | 9636372 |
| prophylactic effect of bovine anti-cryptosporidium hyperimmune colostrum immunoglobulin in healthy volunteers challenged with cryptosporidium parvum. | bovine hyperimmune anti-cryptosporidium colostrum immunoglobulin (baci) decreases the intensity of cryptosporidium parvum infection in vitro. we investigated the prophylactic effect of baci in healthy adults challenged with c. parvum. after we established an oocyst dose that resulted in 100% infection in four volunteers (baseline group), 16 volunteers were randomized to receive (1) baci prior to c. parvum challenge (baci group) and a nonfat milk placebo 30 minutes later, (2) baci prior to and 30 ... | 1998 | 9636857 |
| cryptosporidium and other parasites in ethiopian aids patients with chronic diarrhoea. | previous studies in other african countries have shown high prevalences of isospora belli and cryptosporidium parvum infections in acquired immunodeficiency syndrome (aids) patients with chronic diarrhoea. however, there is lack of information regarding these infectious agents in ethiopian aids patients. thus, this investigation has been aimed at determining the prevalence of cryptosporidium and other related gastrointestinal parasites in aids patients with diarrhoea in seven addis ababa hospita ... | 1998 | 9640833 |
| giardia sp. cysts and infectious cryptosporidium parvum oocysts in the feces of migratory canada geese (branta canadensis). | fecal droppings of migratory canada geese, branta canadensis, collected from nine sites near the chesapeake bay (maryland), were examined for the presence of cryptosporidium parvum and giardia spp. cryptosporidium sp. oocysts were found in feces at seven of nine sites, and giardia cysts were found at all nine sites. the oocysts from three sites were infectious for mice and molecularly identified as the zoonotic genotype of cryptosporidium parvum. waterfowl can disseminate infectious c. parvum oo ... | 1998 | 9647860 |
| determination of immuno-cross-reactivity between cryptosporidium parvum and eimeria spp. | immuno-cross-reactivity between cryptosporidium parvum and eimeria spp. was studied by the indirect fluorescent antibody test (ifat) and western blot procedure. thirty-seven sera from asymptomatic (non-diarrheic) cattle, with known coprological (presence-absence of coccidia) and serological data respecting c. parvum, were tested by ifat using eimeria oocysts as antigen. most sera (54%) displayed immunofluorescence around the surface of the eimeria oocysts. simultaneously, serum samples from rabb ... | 1998 | 9653985 |
| evidence for the shikimate pathway in apicomplexan parasites. | parasites of the phylum apicomplexa cause substantial morbidity, mortality and economic losses, and new medicines to treat them are needed urgently. the shikimate pathway is an attractive target for herbicides and antimicrobial agents because it is essential in algae, higher plants, bacteria and fungi, but absent from mammals. here we present biochemical, genetic and chemotherapeutic evidence for the presence of enzymes of the shikimate pathway in apicomplexan parasites. in vitro growth of toxop ... | 1998 | 9655396 |
| persistent diarrhea in the returned traveler. | in conclusion, the causes of chronic diarrhea in the returned traveler are protean. careful evaluation requires an understanding of where the traveler has been, when they were there, the type of diarrheal illness, medications taken, and knowledge of the patients' other medical problems. protozoa, particularly g. lamblia, c. parvum, and c. cayatenensis, are among the more commonly identified agents. if the patient is immunocompromised, microsporidia and isospora become more likely, and a prior hi ... | 1998 | 9658255 |
| infection by cryptosporidium parvum in renal patients submitted to renal transplant or hemodialysis. | the frequency of infection by cryptosporidium parvum was determined in two groups of renal patients submitted to immunosuppression. one group consisted of 23 renal transplanted individuals, and the other consisted of 32 patients with chronic renal insufficiency, periodically submitted to hemodialysis. a third group of 27 patients with systemic arterial hypertension, not immunosuppressed, was used as control. during a period of 18 months all the patients were submitted to faecal examination to de ... | 1998 | 9662959 |
| paromomycin and geneticin inhibit intracellular cryptosporidium parvum without trafficking through the host cell cytoplasm: implications for drug delivery. | cryptosporidium parvum, which causes intractable diarrhea and lethal wasting in people with aids, occupies an unusual intracellular but extracytoplasmic niche. no reliable therapy for cryptosporidiosis exists, though the aminoglycoside paromomycin is somewhat effective. we report that paromomycin and the related compound geneticin manifest their major in vitro anti-c. parvum activity against intracellular parasites via a mechanism that does not require drug trafficking through the host cell cyto ... | 1998 | 9673275 |
| acute pancreatitis associated with cryptosporidium parvum enteritis in an immunocompetent man. | 1998 | 9675489 | |
| pulmonary cryptosporidiosis in patients with acquired immunodeficiency syndrome. | several reports have showed cryptosporidium species as a cause of intractable diarrhea and malabsorption in patients with acquired immunodeficiency syndrome (hiv). a case of chronic diarrhea in a drug addict woman associated with a symptomatic interstitial pulmonary infection due to cryptosporidium parvum is described. this unusual c. parvum spread into the bronchial tree is underlined and a survey of the literature is made. | 1998 | 9676183 |
| the epidemiology of cryptosporidiosis: application of experimental sub-typing and antibody detection systems to the investigation of water-borne outbreaks. | a technique based on the analysis of banding patterns obtained by sds-page western-blotting of an oocyst wall antigen obtained from faeces has been evaluated to subtype cryptosporidium parvum tyzzer, 1912. this technique appears to have sufficient stability to recognise multiple types of this parasite. a similar western-blotting technique has also been used to assess antibody responses to cryptosporidial antigens in human sera. two systems were developed: one against three antigens of apparent m ... | 1998 | 9684318 |
| cryptosporidium parvum infection in experimentally infected mice: infection dynamics and effect of immunosuppression. | the effect of mouse strain, age, sex, and the size of infective dose on the susceptibility to infection with the coccidium cryptosporidium parvum tyzzer, 1912 was determined using several murine models. mice were infected with c. parvum oocysts originally of cervine origin, maintained by repeat passage in calves. all mice in the experimental groups proved susceptible to infection, though this resulted asymptomatic in all cases. c. parvum infection in balb/c and porton mice exhibited some variati ... | 1998 | 9684319 |
| viability of cryptosporidium parvum oocysts in natural waters. | water-borne transmission of the coccidium cryptosporidium parvum tyzzer, 1912 is frequently responsible for outbreaks of human cryptosporidiosis. one of the most important was reported in 1993 in milwaukee in the united states, where 403,000 cases were recorded. the determination of the percentage of oocysts excystated is the first step in evaluating their viability, but it alone is not sufficient. this percentage depended on the conditions of storage and also the presence of oxidant or disinfec ... | 1998 | 9684321 |
| clinical features of diarrhoea in children caused by cryptosporidium parvum. | 1998 | 9684327 | |
| the role of wild rodents in ecology of cryptosporidiosis in poland. | 1998 | 9684328 | |
| efficacy of nitazoxanide against cryptosporidium parvum in cell culture and in animal models. | nitazoxanide (ntz), a drug currently being tested in human clinical trials for efficacy against chronic cryptosporidiosis, was assessed in cell culture and in two animal models. the inhibitory activity of ntz was compared with that of paromomycin (prm), a drug that is partially effective against cryptosporidium parvum. a concentration of 10 microg of ntz/ml (32 microm) consistently reduced parasite growth in cell culture by more than 90% with little evidence of drug-associated cytotoxicity, in c ... | 1998 | 9687390 |
| control of the immune response by dhea and its metabolites. | the 17 keto steroid, dehydroepiandrosterone (5-androsten-3 beta-17-one, dhea) has been shown to protect mice from a variety of lethal infections. this includes, but is not limited to, infection with viruses (herpesvirus type 2, coxsackievirus b4-cvb4),bacteria (enterococcus faecalis, pseudomonas aeruginosa), and a parasite (cryptosporidium parvum). we have reported that androstenediol (5-androsten-3 beta-17 beta-diol, beta aed), which is derived from dhea, is at least 100x more effective in up-r ... | 1998 | 9691759 |
| molecular characterization of cryptosporidium from various hosts. | a 298 bp region of the cryptosporidium parvum 18s rdna and a 390 bp region of the acetyl-coa synthetase gene were sequenced for a range of human and animal isolates of cryptosporidium from different geographical areas. a distinct genotype is common to isolates from cattle, sheep and goats and also an alpaca from peru and is referred to here as the 'calf'-derived cryptosporidium genotype. another genotype of 'human'-derived isolates also appears to be conserved amongst human isolates although hum ... | 1998 | 9695098 |
| the gamma interferon gene knockout mouse: a highly sensitive model for evaluation of therapeutic agents against cryptosporidium parvum. | cryptosporidiosis is a serious disease in malnourished children and in people with malignancies or aids. current rodent models for evaluating drug therapy against cryptosporidiosis have many limitations, including the need for a high inoculum, the absence of symptoms resembling those seen in humans, and the need to maintain exogenous immunosuppression. we have developed a gamma interferon knockout (gko) mouse model with which to evaluate therapies against c. parvum and have used paromomycin for ... | 1998 | 9705383 |
| 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 ... | 1998 | 9707677 |
| decreased prevalence of intestinal cryptosporidiosis in hiv-infected patients concomitant to the widespread use of protease inhibitors. | 1998 | 9708424 | |
| il-4 protects adult c57bl/6 mice from prolonged cryptosporidium parvum infection: analysis of cd4+alpha beta+ifn-gamma+ and cd4+alpha beta+il-4+ lymphocytes in gut-associated lymphoid tissue during resolution of infection. | resistance of adult c57bl/6 mice to severe cryptosporidium parvum infection is dependent on cd4+alpha beta+ tcr lymphocytes. in this study, we demonstrated that treatment with anti-ifn-gamma mab extended oocyst excretion 18 days longer, and anti-il-4 mab extended oocyst excretion at least 11 days longer than isotype control mab treatment. analysis of the specific activity of anti-ifn-gamma mab present in treated mouse sera suggested that ifn-gamma may have a limited role in the resolution phase ... | 1998 | 9712058 |
| role of immunoglobulin a monoclonal antibodies against p23 in controlling murine cryptosporidium parvum infection. | cryptosporidium parvum is an important diarrhea-causing protozoan parasite of immunocompetent and immunocompromised hosts. immunoglobulin a (iga) has been implicated in resistance to mucosal infections with bacteria, viruses, and parasites, but little is known about the role of iga in the control of c. parvum infection. we assessed the role of iga during c. parvum infection in neonatal mice. iga-secreting hybridomas were developed by using peyer's patch lymphocytes from balb/c mice which had bee ... | 1998 | 9712802 |
| dicationic furans inhibit development of cryptosporidium parvum in hsd/icr suckling swiss mice. | the efficacy of dicationic diarylfurans was evaluated against cryptosporidium parvum by a suckling murine model. candidate drugs were solubilized or suspended in deionized water and administered orally at a constant dose rate on days 0-5 (treatment day 0) to suckling icr swiss mice experimentally inoculated with oocysts of c. parvum. efficacy was based on numbers of oocysts recovered from the intestinal tracts of mice subjected to necropsy examination on day 6. numerous candidate furans signific ... | 1998 | 9714224 |
| [clinical profile of cryptosporidiosis in a pediatric hospital environment in burkina faso]. | data concerning cryptosporidium parvum infection in black africa are highly fragmentary. a 12-month study was carried out on 1392 stool specimens from children under 36 months of age with (n = 756) or without diarrhea (n = 629) in the pediatric department of bobo dioulasso hospital in burkina faso. in 558 children hiv blood tests were also performed. the phenicated fuchsin technique was used to identify cryptosporidia oocysts. results were positive in 72 of the 1392 stool specimens tested (5.2%) ... | 1998 | 9718555 |
| bovine t cell responses to cryptosporidium parvum infection. | to better understand the immune mechanisms important for clearing of the primary infection and the subsequent development of resistance to cryptosporidium parvum infection, several groups have recently characterised changes within the lymphoid cell population of the intestinal mucosa and associated lymphoid tissue in calves with cryptosporidiosis. in naive animals, infection results in a significant increase in the number of cd4+ and cd8+ t cells present within the intraepithelial lymphocyte pop ... | 1998 | 9724879 |
| the signature 10-hydroxy stearic acid thought to correlate with infectivity in oocysts of cryptosporidium species is an artifact. | heating or freezing leads to loss in infectivity of oocysts of cryptosporidium parvum toward neonatal balb/c mice and is reflected in the profile of the polar lipid fatty acids. upon loss of infectivity, the ratio of polar lipid to neutral lipid fatty acid decreased and the relative proportions of 18:1n-9 also decreased; proportions of 18:2n-6 and 20:5n-6 increased, whereas the proportions of 16:0 remained constant with freezing. during these investigations, a novel fatty acid, 10-oh 18:0, was d ... | 1998 | 9727616 |
| the antibody response to 27-, 17-, and 15-kda cryptosporidium antigens following experimental infection in humans. | previous studies have suggested that persons infected with cryptosporidium parvum develop antibody responses to 27-, 17-, and 15-kda c. parvum antigens. studies of volunteers infected with cryptosporidium species provided an opportunity to evaluate the relationship between antibody reactivity to these antigens and infection outcome. as monitored by immunoblot, increases in specific antibody reactivity were more prevalent among volunteers who developed signs and symptoms of cryptosporidiosis (n = ... | 1998 | 9728553 |
| genotypic and phenotypic characterization of cryptosporidium parvum isolates from people with aids. | genotypic analysis of cryptosporidium parvum has demonstrated the presence of two subgroups within the species, whereas biochemical and antigenic characterization have shown more heterogeneity. the clinical relevance of these observations is unknown. c. parvum isolates from people with aids were studied with respect to parasite genotypes and virulence in cell monolayers and laboratory animals. ten of 13 oocyst samples had a characteristic human-associated (h) genotype; 3 had a genotype typical o ... | 1998 | 9728554 |
| identification and cloning of a developmentally regulated cryptosporidium parvum gene by differential mrna display pcr. | to identify cryptosporidium parvum genes expressed during intracellular development, differential mrna display was used to detect differences in gene expression between mock-infected and c. parvum-infected human epithelial cells. a reproducible band present only in c. parvum-infected cells, ddhc-23, was isolated and cloned. southern blot analysis demonstrated that ddhc-23 represented a c. parvum gene. rt-pcr revealed that hc-23 mrna levels decreased from 6 to 12h post-infection (pi), were maxima ... | 1998 | 9729442 |
| evaluation of periparturient dairy cows and contact surfaces as a reservoir of cryptosporidium parvum for calfhood infection. | to determine whether periparturient cows or contact surfaces to which newborn calves are exposed are reservoirs of cryptosporidium parvum oocysts. | 1998 | 9736387 |