| infectivity of preserved cryptosporidium parvum oocysts for immunosuppressed adult mice. | the present study was undertaken to determine the infectivity of cryptosporidium parvum oocysts for immunosuppressed adult c57bl/6n mice after the oocysts had been stored from 1-48 months at 4 degrees c in 2.5% potassium dichromate. all mice inoculated with oocysts 1-18 months old developed patent infections, while mice inoculated with older oocysts remained uninfected. the prepatent period was extended from 2 to 6 or 7 days as the storage time for oocysts increased. the finding that c. parvum o ... | 1996 | 8731022 |
| [diarrhea due to microsporidia in a patient with aids]. | a 26-year-old male aids patient with diarrhea of two-months evolution is reported here. the most relevant intestinal pathogens, including cryptosporidium parvum, were ruled out by routine microbiological tests. stool samples stained with an "oblong" ziehl-neelsen method (fucsin, 7 min instead of 3 min) allowed visualization of organisms resembling microsporidia. both modified trichrome and calcofluor stains showed organisms compatible with enterocytozoon bieneusi. significant titer of antibodies ... | 1995 | 8731580 |
| current therapeutic approaches to cryptosporidiosis in immunocompromised patients. | cryptosporidium parvum is a protozon which can cause a severe debilitating disease in immunocompromised patients. animal models show that cellular immunity is the most important factor protecting against the development of the disease, but patients with a humoral immune deficiency are also at risk. in hiv-infected patients there is a clear relationship between disease severity and cd4-cell counts. the development of insight into the pathogenesis and of new agents is hampered by the lack of an in ... | 1996 | 8737137 |
| intracellular protozoan infection in small intestinal biopsies of patients with aids. light and electron microscopic evaluation. | small intestinal biopsies of 21 patients with acquired immunodeficiency syndrome (aids) with light microscopic findings diagnostic or suspicious for parasite infection were investigated by transmission electron microscopy (tem). tem allowed us to identify and specify the genus and species of involved parasites in 16 out of the 21 cases: 7 cryptosporidium parvum, 5 enterocytozoon bieneusi and 4 isospora belli. cryptosporidium was easily identified on light microscopy (lm), and only slightly influ ... | 1996 | 8739472 |
| comparative evaluation of several techniques for purification of cryptosporidium parvum oocysts from rat feces. | three methods of isolating cryptosporidium parvum oocysts from rat feces were evaluated. oocysts were initially isolated by sucrose density gradient centrifugation. they were further purified by passage through a glass bead column or a percoll gradient or by dialysis. although oocysts recovered from the glass bead column and by dialysis were relatively free of fecal debris, only oocysts recovered from the percoll gradient were free of bacteria. recovered oocysts retained their antigenicity and i ... | 1996 | 8748268 |
| [liver cryptosporidiosis]. | | 1995 | 8749420 |
| detection of cryptosporidium parvum oocysts in faeces: comparison of conventional coproscopical methods and the polymerase chain reaction. | conventional and coproscopical methods were compared with the polymerase chain reaction (pcr) for the detection of cryptosporidium oocysts in bovine faeces. oocysts were not detected in samples seeded with 10,000 oocysts following formol ether sedimentation and examination using auramine phenol (ap) or by immunofluorescent (if) staining. when oocysts were concentrated using sucrose flotation the threshold of detection was 4000 oocysts per gram for both staining methods. following salt flotation ... | 1996 | 8750678 |
| [prevalence of cryptosporidium and giardia in different population groups]. | | 1996 | 8754488 |
| complete development of cryptosporidium parvum in mdbk cells. | sporozoites of cryptosporidium parvum excysted in vitro from bovine oocysts were incubated with monolayers of madin-darby bovine kidney cells. the extent of parasite colonisation was monitored by light microscopy and immunofluorescence. electron microscopy confirmed the complete development and replication of c. parvum within madin-darby bovine kidney cells. | 1996 | 8759799 |
| microbiology of hiv associated bacteraemia and diarrhoea in adults from nairobi, kenya. | we undertook a retrospective descriptive comparison of the spectrum of pathogens responsible for bacteraemia and diarrhoea in hiv antibody positive and negative patients over 4 years (1988-92), in nairobi, kenya. the study population was recruited from primary to tertiary centres of clinical care and consisted of 2858 adults (15 years or older). there were 415 significant blood culture isolates, 192 from 1785 hiv negative patients and 223 from 953 hiv positive patients. there were 233 significan ... | 1996 | 8760961 |
| role of enteric pathogens in the aetiology of neonatal diarrhoea in lambs and goat kids in spain. | faeces samples from diarrhoeic and non-diarrhoeic lambs and goat kids aged 1-45 days were examined for enteric pathogens. cryptosporidium parvum was detected in both diarrhoeic lambs (45%) and goat kids (42%) but not in non-diarrhoeic animals. f5+ (k99+) and/or f41+ escherichia coli strains were isolated from 26% and 22% of the diarrhoeic lambs and goat kids, respectively, although these strains, which did not produce enterotoxins st i or lt i, were found with similar frequencies in non-diarrhoe ... | 1996 | 8760970 |
| azithromycin therapy for cryptosporidium parvum infection in four children infected with human immunodeficiency virus. | cryptosporidium parvum intestinal infection in immunodeficient patients can cause severe intestinal fluid losses with severe dehydration or chronic diarrhea with malnutrition. therapies tried in human beings and animals include paromomycin, clarithromycin, azithromycin, octreotide, hyperimmune bovine colostrum, and bovine transfer factor. no specific therapy has been found to be consistently beneficial to children. we report azithromycin treatment of four children with acquired immunodeficiency ... | 1996 | 8765631 |
| infection dynamics of cryptosporidium parvum in icr outbred suckling mice. | an icr outbred suckling mouse model of cryptosporidiosis was used to explain some of the variability associated with experimental cryptosporidium parvum infections in neonate mice. fourty-four groups of 12 mice each, ranging in age from 4-12 days, each received 1.0 x 10(4) cscl purified oocysts per os in 5 microns pbs. at 6 days post-inoculation (pi), mice were killed by co2 overdose and individually weighed. intestines were then homogenized and oocysts were quantified by hemacytometer. results ... | 1996 | 8768460 |
| detection of cryptosporidium parvum dna in human feces by nested pcr. | cryptosporidium parvum is a coccidian protozoan that causes diarrhea in humans, often chronic and severe in patients with aids. conventionally, diagnosis is made by concentration of stools followed by acid-fast staining (af) or immunofluorescent staining. the threshold of detection in human stool specimens by these methods may require the presence of 50,000 (immunofluorescent staining) to 500,000 (af) oocysts per g of stool. in this study, a nested pcr assay was developed to detect c. parvum dna ... | 1996 | 8784586 |
| evaluation of pcr, nested pcr, and fluorescent antibodies for detection of giardia and cryptosporidium species in wastewater. | giardiasis and cryptosporidiosis are diseases caused by the protozoan parasites giardia lamblia and cryptosporidium parvum. waterborne transmission of these organisms has become more prevalent in recent years, and regulatory agencies are urging that source and finished water be screened for these organisms. a major problem associated with testing for these organisms is the lack of reliable methodologies and baseline information on the prevalence of these parasites in various water sources. our s ... | 1996 | 8787406 |
| viability and infectivity of cryptosporidium parvum oocysts are retained upon intestinal passage through a refractory avian host. | six cryptosporidium-free peking ducks (anas platyrhynchos) were each orally inoculated with 2.0 x 10(6) cryptosporidium parvum oocysts infectious to neonatal balb/c mice. histological examination of the stomachs jejunums, ilea, ceca, cloacae, larynges, tracheae, and lungs of the ducks euthanized on day 7 postinoculation (p.i.) revealed no life-cycle stages of c. parvum. however, inoculum-derived oocysts extracted from duck feces established severe infection in eight neonatal balb/c mice (inoculu ... | 1996 | 8795213 |
| detection of cryptosporidium parvum in raw milk by pcr and oligonucleotide probe hybridization. | cryptosporidium spp. are potential contaminants of food. suspected cases of food-borne cryptosporidiosis are rarely confirmed because of the limited numbers of oocysts in the samples and the lack of sensitive detection methods adaptable to food. pcr was investigated as a means of overcoming this problem. a pcr assay was designed for the specific amplification of a previously sequenced portion of an oocyst protein gene fragment of cryptosporidium parvum (n. c. lally, g. d. baird, s. j. mcquay, f. ... | 1996 | 8795214 |
| detection of a single viable cryptosporidium parvum oocyst in environmental water concentrates by reverse transcription-pcr. | current methods for detection of cryptosporidium parvum oocysts in water are time-consuming and difficult. we have developed a reverse transcription (rt)-pcr which can detect the presence of a single viable oocyst spiked into concentrated environmental water samples. the test is based on the detection of mrna from a c. parvum heat shock protein (hsp). the synthesis of hsp was induced by a short 45 degrees c incubation followed by oocyst lysis by a freeze-thaw process. hsp70 mrna, produced only f ... | 1996 | 8795230 |
| foodborne outbreak of diarrheal illness associated with cryptosporidium parvum--minnesota, 1995. | on september 29, 1995, the minnesota department of health (mdh) received reports of acute gastroenteritis among an estimated 50 attendees of a social event in blue earth county on september 16. this report summarizes the epidemiologic and laboratory investigations of the outbreak, which indicate the probable cause for this foodborne outbreak was cryptosporidium parvum. | 1996 | 8801445 |
| the use of a new viability assay to determine the susceptibility of cryptosporidium and eimeria sporozoites to respiratory inhibitors and extremes of ph. | a new viability assay for cryptosporidium and eimeria sporozoites is described. it involves the use of both acridine orange and bis-benzimide and is more rapid, easier and less subjective than procedures used previously. the assay has been used to investigate the effects of respiratory inhibitors and ph on the sporozoites of c. parvum, c. muris and e. tenella. neither cyanide nor azide reduced the viability of c. parvum or e. tenella, whereas they had some effect on c. muris. this latter organis ... | 1996 | 8810503 |
| prevalence of cryptosporidium in children with enteritis in southern italy. | cryptosporidium parvum is a protozoan which causes self-limiting diarrhea in immunocompetent subjects, and severe life-threatening disease in immunocompromised patients. cryptosporidiosis is more common in developing countries and in infants. in this paper we have evaluated the prevalence of c. parvum in 368 hospitalized children with enteritis, of whom 359 were immunocompetent and 9 hiv-infected. stool specimens were concentrated by sedimentation and stained with a modified ziehl-neelsen method ... | 1996 | 8817198 |
| recently recognised microbial enteropathies and hiv infection. | persistent diarrhoea and small bowel enteropathy are important features of hiv infection. at least 80% of cases of persistent diarrhoea in patients with hiv/aids can be attributed to a specific enteropathogen. the coccidian parasites cryptosporidium parvum, isospora belli and cyclospora and the microsporidia account for at least 50% of cases of persistent diarrhoea in the industrialised and developing world with major contributions from mycobacterium avium complex and other bacteria and cytomegl ... | 1996 | 8818830 |
| in vitro blastogenic responses and interferon-gamma production by intestinal intraepithelial lymphocytes of calves. | intestinal intraepithelial lymphocytes are a large and heterogenous population of lymphocytes located strategically at the entry site of enteric pathogens into the body. their ability to proliferate and produce interferon-gamma in vitro in response to mitogens or interleukin-2 was investigated in four-week-old calves. it was found that they had similar mitogen-induced blastogenic responses and produced interferon-gamma like the peripheral blood lymphocytes of four-week-old calves. preliminary st ... | 1996 | 8819193 |
| anticryptosporidial potential of alpha-1-antitrypsin. | | 1996 | 8822860 |
| effects of a wide range of temperatures on infectivity of cryptosporidium parvum oocysts. | | 1996 | 8822861 |
| characterization of small intestine mucosal lymphocytes during cryptosporidiosis. | | 1996 | 8822862 |
| incidence of cryptosporidium parvum in patients with diarrhea. | | 1996 | 8822863 |
| identification of two potential cryptosporidium parvum protein-encoding regions upstream of hema. | | 1996 | 8822864 |
| bismuth subsalicylate prophylaxis of cryptosporidium parvum infection in immunodeficient mice. | | 1996 | 8822865 |
| significant parity of different phenotypic and genotypic markers between human and animal strains of cryptosporidium parvum. | | 1996 | 8822866 |
| improved survival of severe combined immunodeficiency (scid) mice with cryptosporidiosis by adoptively transferring cd4+ and cd4- cd8- b220- balb/c splenocytes (spls). | | 1996 | 8822867 |
| development of a rapid detection procedure for cryptosporidium, using in vitro cell culture combined with pcr. | | 1996 | 8822868 |
| cryptosporidium parvum: polyamine biosynthesis from agmatine. | | 1996 | 8822869 |
| protective monoclonal antibodies define a distinct, conserved epitope on an apical complex exoantigen of cryptosporidium parvum sporozoites. | | 1996 | 8822870 |
| neutralizing monoclonal antibody protects against cryptosporidium parvum infection by inhibiting sporozoite attachment and invasion. | | 1996 | 8822871 |
| broncho-pulmonary cryptosporidiosis in four hiv-infected patients. | | 1996 | 8822872 |
| differential mrna display analysis of gene expression in cryptosporidium parvum-infected hct-8 cells. | | 1996 | 8822873 |
| detection of selected enzyme activities in cryptosporidium parvum. | | 1996 | 8822874 |
| cloning and expression of sporozoite and oocyst cryptosporidium parvum recombinant proteins. | | 1996 | 8822875 |
| in vitro expression of mrna coding for a cryptosporidium parvum oocyst wall protein. | | 1996 | 8822876 |
| expression of cryptosporidium parvum beta-tubulin sequences in yeast: potential model for drug development. | | 1996 | 8822877 |
| in vitro evaluation of anticryptosporidial agents using mdck cell culture and chemiluminescence immunoassay. | | 1996 | 8822878 |
| disinfection of cryptosporidium parvum oocysts by pulsed light treatment evaluated in an in vitro cultivation model. | | 1996 | 8822879 |
| improved purification methods for calf-derived cryptosporidium parvum oocysts using discontinuous sucrose and cesium chloride gradients. | | 1996 | 8822880 |
| cryptosporidium workshop overview. | | 1996 | 8822881 |
| comparison of oocyst shedding and the serum immune response to cryptosporidium parvum in cattle and pigs. | a comparison was made between oocyst shedding and the presence of specific serum igg antibodies to cryptosporidium parvum in 108 bovines and 90 pigs. oocysts were detected by a commercial immunofluorescence assay in feces from 26.8% of bovines and 34.4% of pigs, whereas positive titers as determined by an indirect fluorescent antibody method were found in sera from 12.9% and 48.9% of the respective animals. infection was significantly most frequent in suckling calves (82.7%) and weaned piglets ( ... | 1996 | 8832734 |
| gaseous disinfection of cryptosporidium parvum oocysts. | purified oocysts of cryptosporidium parvum suspended in approximately 400 microliters of phosphate-buffered saline or deionized water in microcentrifuge tubes were exposed at 21 to 23 degrees c for 24 h to a saturated atmosphere of ammonia, carbon monoxide, ethylene oxide, formaldehyde, or methyl bromide gas. controls were exposed to air. oocysts in each tube were then rinsed and resuspended in fresh, deionized water, and 1 million oocysts exposed to each gas were orally administered to each of ... | 1996 | 8837451 |
| primary and secondary infections with cryptosporidium parvum in immunosuppressed adult mice. | the present study was undertaken to determine if infection of immunocompetent adult c57bl/6n mice with cryptosporidium parvum would render them more resistant to a challenge infection following immunosuppression with dexamethasone (dex). fecal oocyst shedding and parasite colonization of the terminal ilea were greater in immunosuppressed mice than in nonimmunosuppressed mice. secondary infections with c. parvum resulted in decreased oocyst shedding and reduced parasite colonization compared with ... | 1996 | 8842123 |
| causes of chronic diarrhea in patients with aids in thailand: a prospective clinical and microbiological study. | a prospective study was designed to investigate the causes of chronic diarrhea in aids patients in thailand. forty-five patients from bamrasnaradura infectious diseases hospital were enrolled. extensive investigations included multiple stool examinations for ova and parasites, using the stool formalin-ether concentration method, stool culture, stool acid-fast bacilli (afb) stain, stool modified afb stain, esophagogastroduoscopy with duodenal aspirate and biopsy, and colonoscopy with biopsy. biop ... | 1996 | 8844474 |
| biliary cryptosporidiosis in two corn snakes (elaphe guttata). | | 1996 | 8844592 |
| from the centers for disease control and prevention. foodborne outbreak of diarrheal illness associated with cryptosporidium parvum--minnesota, 1995. | | 1996 | 8849738 |
| [an outbreak of waterborne cryptosporidiosis in kanagawa, japan]. | an outbreak of diarrhea due to infection with cryptosporidium occurred among the staff members and customers who visited one of the 10 public houses or a dancing school in a building in hiratsuka, kanagawa prefecture, at the end of summer in 1994. the epidemiological surveys by a questionnaire revealed that 461 out of 736 persons investigated complained of cholera-like or flu-like illness. the clinical manifestations included mucous and/or watery diarrhea (96.7%), abdominal pain (61.6%), fever ( ... | 1996 | 8851385 |
| dose-dependent dielectrophoretic response of cryptosporidium oocysts treated with ozone. | dielectrophoresis, the motion of particles in non-uniform electric field, was investigated as a technology with the potential for rapid analysis of ozonated cryptosporidium parvum oocysts. the ratio of dielectrophoretic collection at two key frequencies (100 khz and 10 mhz) was determined to compare the effect of ozonation at various dosages. a relationship was found between this ratio and the in vitro excystation value obtained at the end of the experiments. the magnitude of the ratio changed i ... | 1996 | 8852351 |
| protozoal colonization of the intestinal tract in institutionalized romanian children. | to determine the prevalence of intestinal parasitic infections in 92 romanian children institutionalized at colentina hospital (bucharest, romania) and at the dystrophic center (vidra, romania), medical charts were reviewed and complete physical examinations were performed. the nutritional status of each child was evaluated, and their sera were tested for the presence of antibodies to human immunodeficiency virus (hiv) and cryptosporidium. fecal samples were collected in 10% formalin and examine ... | 1996 | 8852962 |
| potential antifolate resistance determinants and genotypic variation in the bifunctional dihydrofolate reductase-thymidylate synthase gene from human and bovine isolates of cryptosporidium parvum. | we have determined the nucleic acid sequences of a gene encoding the bifunctional enzyme dihydrofolate reductase-thymidylate synthase (dhfr-ts) from bovine and human aids isolates of cryptosporidium parvum. the dhfr-ts gene was isolated from genomic dna libraries by hybridization with a probe amplified from c. parvum genomic dna using generic ts primers in the polymerase chain reaction. genomic southern and electrophoretic karyotype analyses reveal c. parvum dhfr-ts is a single-copy gene on a 12 ... | 1996 | 8855552 |
| the infectivity of cryptosporidium parvum in healthy volunteers. | | 1996 | 8856592 |
| parasitic diseases in immunocompromised hosts. cryptosporidiosis, isosporiasis, and strongyloidiasis. | cryptosporidiosis and isosporiasis are intestinal infections caused by the protozoan parasites cryptosporidium parvum and isospora belli, respectively. hiv infection and other immunodeficiency diseases predispose human subjects to severe and prolonged cryptosporidiosis. there is also evidence that hiv infection predisposes to chronic isosporiasis. strongyloidiasis is caused by a nematode worm, strongyloides stercoralis. administration of corticosteroids to patients with chronic low-grade s. ster ... | 1996 | 8863046 |
| in vitro anticryptosporidial activity of dinitroaniline herbicides. | despite the evaluation of over 100 antimicrobial drugs, the diarrheal disease cryptosporidiosis has remained refractory to treatment. we report the evaluation of five dinitroaniline herbicides including trifluralin, profluralin, nitralin, pendimethalin, and fluchloralin for anticryptosporidial activity in an in vitro cultivation model of cryptosporidium parvum. all five compounds exhibited significant anticryptosporidial activities with no corresponding evidence of toxicity. the most active comp ... | 1996 | 8867379 |
| a chemiluminescence immunoassay for evaluation of cryptosporidium parvum growth in vitro. | a chemiluminescence immunoassay (clia) was developed to detect cryptosporidium parvum growth in madin-darby canine kidney (mdck) cell cultures. optimal results were obtained when mdck cells were plated at a density of 1 x 10(4) cells/well (96-well plate) and maintained as a monolayer for 4 days prior to infection with 2 x 10(4) parasites/well. two compounds (paromomycin and maduramicin) were evaluated and shown to have selective activity against c. parvum in a dose-dependent manner. there was ex ... | 1996 | 8867380 |
| prevalence, detection and control of cryptosporidium parvum in food. | the role of cryptosporidium parvum as a foodborne pathogen has not been well documented. epidemiological features of this parasitic protozoon lead to the assumption that the incidence of cryptosporidiosis due to contaminated food is under-estimated. the high prevalence of c. parvum among dairy herds has increased the spread of oocysts in the farm environment, and their potential presence in raw milk and other raw foods. in october 1993, the first well-documented foodborne outbreak was reported i ... | 1996 | 8880324 |
| emerging diarrheal pathogens: cryptosporidium parvum, isospora belli, cyclospora species, and microsporidia. | | 1996 | 8880880 |
| cryptosporidium parvum is not transmissible to fish, amphibians, or reptiles. | a recent report suggested that an isolate of cryptosporidium parvum had established infections in fish, amphibians, and reptiles and raises concern that animals other than mammals might be a potential source of waterborne cryptosporidium oocysts. to test this possibility, viable c. parvum oocysts, infectious for neonatal balb/c mice, were delivered by gastric intubation to bluegill sunfish, poison-dart frogs, african clawed frogs, bearded dragon lizards, and corn snakes. histological sections of ... | 1996 | 8885883 |
| simplified methods for obtaining purified oocysts from mice and for growing cryptosporidium parvum in vitro. | seven- to 8-day-old arc/swiss mice were infected with 100,000-120,000 cryptosporidium parvum oocysts. at 8 days postinfection (pi) the jejunum, ileum, cecum, colon, and rectum were removed. using a simple extraction procedure and purification by ficoll gradient centrifugation, we rountinely obtained between 3-6 million and up to 15 million purified oocysts per mouse. for in vitro cultivation, purified oocysts were pretreated in a low ph (2.5-3) 0.5% trypsin solution for 20 min, resuspended in su ... | 1996 | 8885885 |
| a cloned gene of cryptosporidium parvum encodes neutralization-sensitive epitopes. | two mab, c6b6 and 7d10, each significantly reduced infection of mice by cryptosporidium parvum and reacted with a 23-kda glycoprotein (p23) of geographically disperse c. parvum isolates. the antibodies were used to identify plaques in a cdna library prepared from c. parvum sporozoite mrna. cdna insert sequences from positive plaques were determined and used to isolate additional clones encoding p23 coding sequences. a consensus open reading frame of 333 base pairs, encoding 111 amino acids, was ... | 1996 | 8892291 |
| developments in microbiological risk assessment models for drinking water--a short review. | microbiological risk assessment (mra) is emerging method to predict the risks of infection from waterborne pathogens (e.g. rotavirus and cryptosporidium parvum) in the drinking water supply. the objectives of this paper are to review the appropriateness of current models, with emphasis on pathogen exposures through drinking water, and to consider the information necessary to further their development. calculating pathogen exposures in mra is currently limited by the fact that pathogen density da ... | 1996 | 8896351 |
| kinetics of mucosal ileal gamma-interferon response during cryptosporidiosis in immunocompetent neonatal mice. | the kinetics of serum and ileal interferon-gamma (ifn-gamma) content were determined during recovery from cryptosporidiosis in nmri suckling mice. a total of 60 mice aged 4 days were inoculated by intragastric gavage with 10(4) cryptosporidia (n = 30) or phosphate-buffered saline (n = 30). six animals per group were killed on days 0, 3, 6, 9 and 13 postinoculation. blood samples and ileum were collected. experimental infection was followed by a rise in parasite load in the ileum starting on day ... | 1996 | 8897498 |
| alterations of the mucosal immune system due to cryptosporidium parvum infection in normal mice. | the mechanism with which the immune system of an immunocompetent host responds to cryptosporidium parvum infection is still poorly understood. we have therefore investigated the immune response of adult immunocompetent c57bl/6 mice at days 6 and 10 to postinfection during a self-limiting c. parvum infection. we evaluated the immune changes at the levels of intestinal intraepithelium and lamina propria as well as mesenteric lymph nodes. at day 6 postinfection, there was a decrease in the producti ... | 1996 | 8912874 |
| field testing of prophylactic measures against cryptosporidium parvum infection in calves in a california dairy herd. | to test the ability of oral vaccination or probiotic treatment with lactic acid-producing bacteria to protect calves from cryptosporidium parvum infection under field conditions. | 1996 | 8915434 |
| targeting the minor groove of dna: crystal structures of two complexes between furan derivatives of berenil and the dna dodecamer d(cgcgaattcgcg)2. | crystal structures are reported of complexes of two novel furan derivatives of berenil with alkyl benzamidine groups bound to the dna sequence d(cgcgaattcgcg)2. they have both been determined to 2.2 a resolution and refined to r factors of 16.9% and 18.6%. in both structures the alkyl substituents, cyclopropyl and isopropyl, are found to be orientated away from the floor of the minor groove. the drugs are located in the minor groove by two strong amidinium hydrogen bonds, to the o2 of the thymin ... | 1996 | 8917643 |
| hydrophobic and electrostatic cell surface properties of cryptosporidium parvum. | microbial adhesion to hydrocarbons and microelectrophoresis were investigated in order to characterize the surface properties of cryptosporidium parvum. oocysts exhibited low removal rates by octane (only 20% on average), suggesting that the cryptosporidium sp. does not demonstrate marked hydrophobic properties. a zeta potential close to -25 mv at ph 6 to 6.5 in deionized water was observed for the parasite. measurements of hydrophobicity and zeta potential were performed as a function of ph and ... | 1996 | 8919783 |
| an evaluation of methods for the simultaneous detection of cryptosporidium oocysts and giardia cysts from water. | methods for the simultaneous detection of cryptosporidium parvum oocysts and giardia cysts from water are described and their relative recovery efficiencies are assessed for seeded samples of both tap and river water. cartridge filtration, membrane filtration, and calcium carbonate flocculation were evaluated, and steps to optimize the concentration procedures were undertaken. increasing centrifugation to 5,000 x g, coupled with staining in suspension, was found to increase the overall efficienc ... | 1996 | 8919791 |
| effects of low temperatures on viability of cryptosporidium parvum oocysts. | microcentrifuge tubes containing 8 x 10(6) purified oocysts of cryptosporidium parvum suspended in 400 microliters of deionized water were stored at 5 degrees c for 168 h or frozen at -10, -15, -20, and -70 degrees c for 1 h to 168 h and then thawed at room temperature (21 degrees c). fifty microliters containing 10(6) oocysts was administered to each of five to seven neonatal balb/c mice by gastric intubation. segments of ileum, cecum, and colon were taken for histology from each mouse 72 or 96 ... | 1996 | 8919806 |
| comparison of the phosphofructokinase and pyruvate kinase activities of cryptosporidium parvum, eimeria tenella and toxoplasma gondii. | oocysts of cryptosporidium parvum were shown to contain a pyrophosphate-dependent phosphofructokinase (ppi-pfk) similar to those previously described for eimeria tenella and toxoplasma gondii. ppi-pfk of c. parvum displayed simple hyperbolic kinetics with respect to its substrate fructose 6-phosphate and was not affected by fructose 2,6-bisphosphate, the major allosteric activator of most atp-pfks. inorganic pyrophosphatase was not detectable in any of the three parasites. t. gondii tachyzoites ... | 1996 | 8919992 |
| an epidemiological survey of cryptosporidium parvum infection in randomly selected inhabitants of seoul and chollanam-do. | an epidemiological survey was performed to know the status of cryptosporidium sp. infection among the people in seoul and chollanam-do in 1992. one village of chollanam-do (hwasun-gun) which showed the highest oocyst positive rate was re-surveyed in 1995 for human infection and for cattle also. the subjected areas consisted of 8 urban villages ( = dongs) of seoul and 4 urban ( = dongs) and 7 rural ( = myons) villages of chollanam-do. a total of 3,146 fecal samples was collected randomly, and sme ... | 1996 | 8925243 |
| codon usage in cryptosporidium parvum differs from that in other eimeriorina. | codon usage of crytosporidium parvum was compared with those of other eimeriorina toxoplasma gondii and eimeria tenella and revealed a biased use of synonymous codons with a preference for nnu (40.0%) and nna (33.4%). there was no close resemblance of the codon usage of c. parvum to t. gondii (correlation coefficient, r = 0.14) or e. tenella (r = 0.14) but it was similar to entamoeba histolytica (r = 0.75) and plasmodium falciparum (r = 0.5). analysis of the codon usage in homologous gene sequen ... | 1996 | 8935947 |
| cryptosporidiosis in washington state: an outbreak associated with well water. | in 1994, an outbreak of cryptosporidiosis occurred in a rural community in washington state where water was supplied by two deep unchlorinated wells. confirmed case-patients had a stool specimen containing cryptosporidium parvum oocysts. probable case-patients had diarrhea lasting > or = 5 days. sixty-two households (68.1% of 91) responded to a survey. eighty-six cases (15 confirmed, 71 probable) were identified, for an attack rate of 50.9% (86/169 residents). drinking unboiled well water was as ... | 1996 | 8940238 |
| regulation of the immune response by dehydroepiandrosterone and its metabolites. | dehydroepiandrosterone (5-androsten-3 beta-ol-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 (herpes virus type 2, coxsackie virus b4 (cb4)), bacteria (enterococcus faecalis, pseudomonas aeruginosa), and a parasite (cryptosporidium parvum). we have previously reported that androstenediol (5-androstene-3 beta, 17 beta-diol, aed), derived from dhea, is at least 100 x more effective in up-regulating syst ... | 1996 | 8943803 |
| diagnosis of cryptosporidium parvum in patients with severe diarrhea and aids. | the sensitivity of noninvasive stool microscopy and endoscopic biopsies from the upper and lower gastrointestinal tract in the diagnosis of cryptosporidium parvum in patients with aids is not known. we evaluated 30 severely immunocompromised patients with aids and diarrhea caused by c. parvum. c. parvum was diagnosed by either stool microscopy, endoscopic biopsy, or both. patients submitted a mean (+/-sem) of 3.3 +/- 0.3 stool samples, each microscopically evaluated for ova and parasites. upper ... | 1996 | 8943985 |
| treatment of severe diarrhea caused by cryptosporidium parvum with oral bovine immunoglobulin concentrate in patients with aids. | we prospectively evaluated the safety and efficacy of colostrum-derived bovine immunoglobulin concentrate in the treatment of diarrhea caused by cryptosporidium parvum in patients with aids. a total of 24 patients with severe chronic diarrhea and aids were stratified to one of three cohorts: (1) c. parvum infection alone (n = 16), (2) c. parvum and a second opportunistic infection (n = 4), and (3) idiopathic aids enteropathy with no identified source of infection (n = 3) or an untreatable opport ... | 1996 | 8948373 |
| jejunal water and electrolyte transport in human cryptosporidiosis. | cryptosporidiosis may have severe clinical consequences in both immunocompromised and immunocompetent individuals. however, pathophysiological mechanisms that are responsible for diarrhea are poorly understood. we performed jejunal perfusion studies in patients with human immunodeficiency virus-related cryptosporidial diarrhea to measure water and electrolyte transport in vivo. five patients with human immunodeficiency virus-related cryptosporidiosis and nine healthy volunteers were studied usin ... | 1996 | 8888726 |
| in-vitro activity of macrolides alone and in combination with artemisin, atovaquone, dapsone, minocycline or pyrimethamine against cryptosporidium parvum. | the anticryptosporidial activity of four macrolides alone and in combination with other antimicrobial agents was investigated against ten clinical isolates of cryptosporidium parvum recovered from stools of aids patients. the susceptibility tests were performed by inoculation of the protozoa on to cell monolayers and determining the parasite count after 72 h incubation at 37 degrees c. the culture medium was supplemented with dulbecco's modified eagle's medium containing serial dilutions of azit ... | 1996 | 8889715 |
| detection of cryptosporidium parvum dna in formed human feces by a sensitive pcr-based assay including uracil-n-glycosylase inactivation. | we developed a pcr-based method that can be used to identify cryptosporidium parvum in human feces. fecal oocysts were concentrated by centrifugation on a sodium chloride gradient and filtration on a nitrocellulose filter prior to dna extraction and pcr amplification of a 452-bp c. parvum-specific dna sequence with a protocol including dutp and uracil-n-glycosylase. all samples obtained from naturally infected humans (n = 10), calves (n = 4), and goats (n = 2) were positive. a 100% detection rat ... | 1997 | 8968918 |
| sequence of the parasitic protozoan, cryptosporidium parvum, putative protein disulfide isomerase-encoding dna. | a composite 1876-bp dna encoding a putative protein disulfide isomerase (pdi) has been constructed from clones isolated from cryptosporidium parvum (c. parvum) genomic and cdna libraries and the nucleotide sequence determined. as predicted from the open reading frame (orf), the protein product has a predicted molecular size of 54 kda and a high degree of homology to pdis from other species. | 1996 | 8973335 |
| protease activity associated with excystation of cryptosporidium parvum oocysts. | a cryptosporidium parvum homogenate (cph), prepared from partially excysted oocysts, was examined for proteolytic activity capable of hydrolyzing azocasein. protease activity, measured at ph 7.0, was not detected in fresh oocysts but increased progressively with incubation at 37 c. activity peaked after 60 min incubation but progressively decreased with extended incubation intervals. cryptosporidial protease activity was significantly inhibited (p < 0.01) by the serine protease inhibitors phenyl ... | 1996 | 8973395 |
| activation of intestinal intraepithelial t lymphocytes in calves infected with cryptosporidium parvum. | the objective of this study was to identify disease-related changes in lymphocyte populations within ileal mucosae of calves with cryptosporidiosis. groups of five neonatal calves were orally infected at 3 days of age with 10(8) oocysts and maintained in enteric-pathogen-free conditions until clinical disease was established or until the animals had recovered from disease. age-matched uninfected calves were used for comparison. ileal mucosal lymphocytes were collected, quantitated, and phenotype ... | 1997 | 8975910 |
| comparison of primers and optimization of pcr conditions for detection of cryptosporidium parvum and giardia lamblia in water. | eight pairs of published pcr primers were evaluated for the specific detection of cryptosporidium parvum and giardia lamblia in water. detection sensitivities ranged from 1 to 10 oocysts or cysts for purified preparations and 5 to 50 oocysts or cysts for seeded environmental water samples. maximum sensitivity was achieved with two successive rounds of amplification and hybridization, with oligonucleotide probes detected by chemiluminescence. primer annealing temperatures and mgcl2 concentrations ... | 1997 | 8979344 |
| effect of lactobacillus reuteri on intestinal resistance to cryptosporidium parvum infection in a murine model of acquired immunodeficiency syndrome. | efficacy of lactobacillus reuteri as a probiotic for the control of cryptosporidium parvum infection was evaluated in c57bl/6 female mice that were immunosuppressed by intraperitoneal inoculation with the lp-bm5 leukemia virus. four months after inoculation, mice developed lymphadenopathy, splenomegaly, and susceptibility to c. parvum infection. after daily prefeeding with l. reuteri (10(8) cfu/day) for 10 days, mice were challenged with 6.5 x 10(6) c. parvum oocysts and fed l. reuteri during th ... | 1997 | 8985225 |
| local th1 and th2 responses to parasitic infection in the intestine: regulation by ifn-gamma and il-4. | control of parasitic infections is dependent on the production of cytokines that activate mechanisms which limit invasion, reproduction or survival of the parasite. in contrast, conditions that induce inappropriate cytokine responses facilitate the spread of infection and ultimately exacerbate the level of disease. measurement of local cytokine responses to different gastrointestinal parasites, such as the intracellular protozoan, cryptosporidium parvum, and luminal dwelling nematodes like nippo ... | 1996 | 8988879 |
| cryptosporidium infection in infancy as a cause of malnutrition: a community study from guinea-bissau, west africa. | cryptosporidium parvum causes persistent diarrhea in young children in developing countries. to determine the interaction between nutritional status and cryptosporidiosis, an open cohort of 1064 children younger than 3 y of age was followed for 1441 child-years by weekly diarrhea recall visits. a total of 5072 weight and 4264 height measurements was made. there were no tendencies of low weight (p = 0.38) or height (p = 0.16) in children who acquired cryptosporidiosis. cryptosporidiosis in infanc ... | 1997 | 8988927 |
| waterborne protozoan pathogens. | protozoan parasites were the most frequently identified etiologic agents in waterborne disease outbreak from 1991 to 1994. the waterborne parasites giardia lamblia, naegleria fowleri, acanthamoeba spp., entamoeba histolytica, cryptosporidium parvum, cyclospora cayetanesis, isospora belli, and the microsporidia are reviewed. for each parasite, the review includes history, life cycle, incidence, symptoms, and therapy. clinical detection methods are compared, and emerging technologies are discussed ... | 1997 | 8993859 |
| inhibition of complete development of cryptosporidium parvum in caco-2 cells. | | 1996 | 8997571 |
| genotyping human and bovine isolates of cryptosporidium parvum by polymerase chain reaction-restriction fragment length polymorphism analysis of a repetitive dna sequence. | in order to define transmission routes of cryptosporidiosis and develop markers that distinguish cryptosporidium parvum isolates, we have identified 2 polymorphic restriction enzyme sites in a c. parvum repetitive dna sequence. the target sequence was amplified by polymerase chain reaction from 100 to 500 oocysts and the amplified product was subjected to restriction enzyme digestion. typing of 23 isolates showed that 10/10 calf isolates had the same profile. in contrast, 2 patterns were observe ... | 1996 | 8998987 |
| gut coccidia--isospora, cryptosporidium, cyclospora and sarcocystis. | the gut coccidia are members of a large, varied, and exclusively intracellular group of protozoan parasites, four species of which (isospora, cryptosporidium, cyclospora, and sarcocystis) are human pathogens. the first three, but particularly cryptosporidium parvum, have moved from medical curiosities to major problems with the coming of the acquired immunodeficiency syndrome (aids) epidemic, but are now known to also cause disease in the immunocompetent patient. they are easy to acquire and dif ... | 1997 | 9000500 |
| a new acid-fast trichrome stain for simultaneous detection of cryptosporidium parvum and microsporidial species in stool specimens. | the detection in stool specimens of cryptosporidium parvum and microsporidia, the most frequent parasitic pathogens causing diarrhea in aids patients, until now has depended on two different staining methods. however, since double infections occur and minimization of laboratory costs is mandatory, development of a method for simultaneous detection of these parasites appeared desirable. we report on a new, inexpensive, and easy-to-perform staining procedure to demonstrate both acid-fast oocysts o ... | 1997 | 9003613 |
| [cryptosporidia associated gastroenteritis: epidemiologic study of children in tyrol and vorarlberg]. | stool samples from 523 children aged between 3 months and 6 years were examined for cryptosporidium parvum by means of the direct immunofluorescence technique in march 1996. the specimens were sent to the federal public health laboratory in innsbruck from general practitioners and pediatricians and from hospitals in tyrol and vorarlberg. the study was performed during the cold season in an area that does not employ surface water for the production of drinking water. oocysts of cryptosporidia wer ... | 1996 | 9005680 |
| asymptomatic and symptomatic cryptosporidiosis: their acute effect on weight gain in peruvian children. | this study investigated whether a child's first infection with cryptosporidium parvum had an acute effect on weight gain. specifically, the authors compared monthly rates of weight gain between c. parvum-infected and noninfected children. over a 2-year period (1989-1991), a cohort of peruvian children aged 0-3 months at recruitment were followed twice weekly for assessment of daily diarrheal status, weekly for c. parvum stool examinations, and monthly for anthropometric measurements. data on 207 ... | 1997 | 9006312 |
| molecular karyotype analysis of cryptosporidium parvum: evidence for eight chromosomes and a low-molecular-size molecule. | we report improved separation of chromosome-sized dna molecules of the coccidian parasite cryptosporidium parvum with contour-clamped homogeneous electric fields (chef). we used scanning densitometry to determine that the most likely number of chromosomes is eight. molecular probes consisting of cloned genes were used to distinguish each of five bands visible on chef gels. we have also identified a low-molecular-size dna molecule possibly related to the 35-kb circular dnas found in other apicomp ... | 1997 | 9008274 |
| prevalence of cryptosporidium infections in pigs in aragón (northeastern spain). | faecal samples from 620 pigs randomly selected from 27 farms throughout aragón were examined to determine the prevalence of cryptosporidium infections. detection of oocysts was performed using the ethyl-acetate stool concentration method and the modified ziehl-neelsen technique. cryptosporidium parvum oocysts were identified in 136 (21.9%) pigs from 21 (77.8%) farms. infected animals ranged from 1 to 6 months old and oocysts were not detected in suckling piglets or adults. infection rates were s ... | 1996 | 9011017 |
| anti-oxidant enzymes in cryptosporidium parvum oocysts. | oocysts of cryptosporidium parvum showed relatively low levels of sod activity. the sod which had a pi of 4.8 and an approximate molecular weight of 35 kda appeared to be iron dependent. catalase, glutathione transferase, glutathione reductase and glutathione peroxidase activity could not be detected, nor could trypanothione reductase. no nadh or nadph oxidase activity could be detected, nor could peroxidase activity be demonstrated using o-dianisidine, guaiacol, nadph or nadh as co-substrates. ... | 1997 | 9011070 |
| outbreaks of escherichia coli o157:h7 infection and cryptosporidiosis associated with drinking unpasteurized apple cider--connecticut and new york, october 1996. | in october 1996, unpasteurized apple cider or juice was associated with three outbreaks of gastrointestinal illness. in the western united states, an outbreak of escherichia coli o157:h7 infections associated with unpasteurized commercial apple juice caused illness in 66 persons and one death. in addition, one outbreak of apple cider-related e. coli o157:h7 infections and another of cider-related cryptosporidium parvum infections occurred in the northeast. apple cider is a traditional beverage p ... | 1997 | 9011776 |