| comparison of staining and concentration techniques for detection of cryptosporidium oocysts in cat faecal specimens. | modified ziehl-neelsen (mzn), auramine-phenol (a-p) and fluorescein isothiocyanate-labelled (fitc-labelled) monoclonal antibody (mab) techniques were compared for detection of cryptosporidium parvum oocysts in cat faecal specimens inoculated with known numbers of c. parvum oocysts. of the three techniques, the fitc-labelled mab technique detected more oocysts than the mzn and a-p techniques (p < 0.05), but a-p was more efficient than mzn (p < 0.05). comparison of sucrose flotation, zinc sulphate ... | 1992 | 1283041 |
| [cryptosporidium parvum and giardia lamblia--incidence in surface and drinking water--significance and detection]. | cryptosporidium parvum and giardia lamblia are protozoan parasites which can cause gastroenteritis in man and animal. surface water and drinking-water play an important role in transmission of the disease. the parasites can be detected by extensive and time-consuming procedures only. in this paper we describe a new way to isolate c. parvum and g. lamblia from water by a modification of essential steps of the original method of rose. the new method applies the separation by flow centrifugation, t ... | 1992 | 1286249 |
| cryptosporidium: different behaviour in calves of isolates of human origin. | the behaviour in calves of 3 cryptosporidium human isolates was analysed in comparison with a bovine isolate. twenty-four neonatal calves were infected. an isolate from a patient infected with human immunodeficiency virus (hiv) and showing mild cryptosporidiosis caused severe diarrhoea with a high production of oocysts in neonatal calves, as did a bovine isolate (group 1). two human isolates, obtained from hiv patients with severe cryptosporidiosis, caused mild diarrhoea with low oocyst producti ... | 1992 | 1287926 |
| rapid purification and concentration technique for cryptosporidium parvum oocysts. | | 1992 | 1287928 |
| [experimental cryptosporidium parvum infection in a korean native calf isolated from a korean mouse]. | this study was performed to investigate experimental transmission of cryptosporidium parvum in a calf. a 25-day-old korean native calf was inoculated per os with 1 x 10(6) c. parvum oocysts isolated from a korean mouse. the calf commenced oocyst discharge in feces on post-inoculation day 4, and continued until the day 11. the number of discharged oocysts peaked (4.9 x 10(5)) on post-inoculation day 6. however, the calf did not show signs of diarrhea. the present results indicate that c. parvum i ... | 1992 | 1297415 |
| neutralization-sensitive epitopes are conserved among geographically diverse isolates of cryptosporidium parvum. | isolates of cryptosporidium parvum from new york, florida, brazil, mexico, and peru were examined for the presence of two sporozoite surface epitopes originally identified in an iowa isolate by neutralizing monoclonal antibodies (mabs) 18.44 and 17.41. immunofluorescence microscopy and immunoblotting demonstrated the presence of both epitopes on all isolates. incubation of deae-cellulose-purified sporozoites of the new york, florida, brazil, and mexico isolates with mab 18.44 or 17.41 significan ... | 1992 | 1372299 |
| cryptosporidium parvum sporozoite staining by propidium iodide. | modified ziehl-neelsen (zn) acid-fast stain is the usual method for detection of cryptosporidium oocysts in feces. propidium iodide permitted us to stain free or intra-oocyst sporozoites. with the zn method only 3-5% of the oocysts purified from three human and one experimentally infected lamb dichromate-preserved feces were stained by carbol fuchsin. these fuchsin-stained oocysts were free of intact sporozoites as identified by propidium iodide staining. treatment with 10% formalin or 0.5% sodi ... | 1992 | 1379215 |
| comparison of the host ranges and antigenicity of cryptosporidium parvum and cryptosporidium wrairi from guinea pigs. | oocysts of a cryptosporidium isolate from guinea pigs were not infectious for adult mice, but were infectious for two of three newborn calves and for suckling mice. however, oocysts isolated from calves or mice infected with guinea pig cryptosporidium were not infectious for guinea pigs. four isolates of c. parvum from calves were incapable of infecting weanling guinea pigs. microscopic examination of tissue from the colon and cecum of suckling guinea pigs inoculated with c. parvum revealed spar ... | 1992 | 1386385 |
| identification and partial purification of a lectin on the surface of the sporozoite of cryptosporidium parvum. | a human-derived isolate of cryptosporidium parvum from a symptomatic patient with the acquired immunodeficiency syndrome was expanded in vivo by infecting a neonatal calf with 10(8) oocysts. sporozoites were isolated from 4 x 10(10) oocysts harvested from this single infection, and the characteristics of mixed hemagglutination (ha) with rabbit erythrocytes were determined. sporozoite ha was inhibited by bovine submaxillary mucin (bsm), hog gastric mucin, and orosomucoid, but not by simple sugars ... | 1992 | 1403433 |
| persistent diarrhea associated with aids. | chronic diarrhea and wasting are very common manifestations of aids in adults in developing countries. etiologic studies show that protozoa (including cryptosporidium parvum, isospora belli, and enterocytozoon bieniusi) and mycobacterium avium-intracellulara are the most frequently identified pathogens. limited data in children suggest that common enteric pathogens are equally as likely in hiv+ and hiv- babies. preliminary analysis of an ongoing longitudinal study of 469 babies born to mothers w ... | 1992 | 1421940 |
| detection of cryptosporidium parvum dna in fixed, paraffin-embedded tissue by the polymerase chain reaction. | the objective of this project was to demonstrate detection of cryptosporidium parvum dna in fixed, paraffin-embedded tissue using the polymerase chain reaction (pcr). dna was purified from six samples of fixed, paraffin-embedded tissue that were histologically positive for c. parvum and used in the pcr. previously developed oligonucleotide primers specific for c. parvum were used to amplify a 452-base target sequence, and a 20-base synthetic probe labeled with digoxigenin-11-dutp was used to det ... | 1992 | 1443342 |
| characterization of a > 900,000-m(r) cryptosporidium parvum sporozoite glycoprotein recognized by protective hyperimmune bovine colostral immunoglobulin. | cryptosporidium parvum, a zoonotic apicomplexan pathogen, causes profound diarrhea, malnutrition, and dehydration in patients with aids. a less severe, self-limited disease occurs in immunocompetent individuals, particularly children, animal handlers, and residents of the developing world. very little is known about the biology of the organism, the pathophysiology of the disease process, or the mechanism of protective immunity. there is no effective therapy for cryptosporidiosis, but hyperimmune ... | 1992 | 1452347 |
| evaluation of a new monoclonal antibody combination reagent for direct fluorescence detection of giardia cysts and cryptosporidium oocysts in human fecal specimens. | giardia lamblia and cryptosporidium parvum can cause severe symptoms in humans, particularly in the immunologically compromised. monoclonal antibody reagents offer increased sensitivity and an excellent alternative to conventional staining methods. these reagents are helpful when screening large numbers of patients or those with minimal symptoms. problems of false-positive and false-negative results with routine staining methods for stool parasites can be eliminated with monoclonal antibody reag ... | 1992 | 1452711 |
| bovine humoral immune response to cryptosporidium parvum. | cryptosporidiosis is a diarrheal disease predominantly affecting cattle and humans. sera from experimentally infected calves and calves of various ages with no histories of exposure were evaluated for immunoglobulin g to cryptosporidium parvum. an age-associated increase in immunoglobulin g was present in experimental calves and in calves with no histories of infection from 1 to 3, but not > 3, months of age. | 1992 | 1452716 |
| malabsorption of vitamin a in preruminating calves infected with cryptosporidium parvum. | serum retinol, retinyl palmitate, and total vitamin a concentrations, and jejunoileal morphology were examined in neonatal calves infected with cryptosporidium parvum. group-1 calves served as noninfected controls and, after an adjustment period, were given 50 ml of saline solution i.v. every 12 hours for 6 days. group-2 calves were inoculated with 10(7) c parvum oocysts and, after the onset of diarrhea, were given 50 ml of saline solution i.v. every 12 hours for 6 days. group-3 calves were inoc ... | 1992 | 1456546 |
| evaluating measures to control intestinal parasitic infections. | intestinal parasitic infections are among the most common infections of humans in developing countries, but the resources available for their control are severely limited. careful evaluation of control measures is essential to ensure that they are cost-effective. the evaluation of the effects of control on intestinal helminths and intestinal protozoa requires an understanding of the different epidemiological patterns of these two groups of parasites. the transmission dynamics and morbidity assoc ... | 1992 | 1462652 |
| immunological characterization of a 17-kda antigen from cryptosporidium parvum recognized early by mucosal iga antibodies. | cryptosporidium parvum antigens were characterized by immunoblot analysis of sera and intestinal secretions of balb/c mice orally infected with 10(5) oocysts. a major band at 17 kda under non-reduced conditions and at 18 kda under reduced conditions was recognized by anti-c. parvum iga and igg in serum and intestinal secretions from day 15 post-infection. this recognition persisted throughout the experiment (day 30). mouse-serum antibodies raised against the 17-kda purified antigen (p17) showed ... | 1992 | 1468619 |
| a 2359-base pair dna fragment from cryptosporidium parvum encoding a repetitive oocyst protein. | a cryptosporidium parvum lambda gt11 expression library was constructed using ecori-digested genomic dna extracted from in vitro-excysted oocysts. screening of this library with rat anti-cryptosporidium antiserum led to the isolation of a clone containing a 2359-bp ecori fragment. when this fragment was ligated into the ecori site of plasmid vector pms1s, the resulting clone expressed a 200-kda beta-galactosidase fusion protein. western blot analysis using serum raised against this fusion protei ... | 1992 | 1475003 |
| intestinal parasites in zambian patients with aids. | previous studies have found a high prevalence of isospora belli and cryptosporidium parvum infections in african acquired immune deficiency syndrome (aids) patients with chronic diarrhoea. we aimed to determine the prevalence of gastrointestinal parasite in aids patients in hospital, not only those with diarrhoea, and to compare them with the general community. clinically diagnosed aids patients in a zambian teaching hospital were interviewed and examined, and stool specimens were studied for pa ... | 1992 | 1475829 |
| viability of cryptosporidium parvum oocysts: correlation of in vitro excystation with inclusion or exclusion of fluorogenic vital dyes. | a viability assay for oocysts of cryptosporidium parvum based on the inclusion or exclusion of two fluorogenic vital dyes, 4',6-diamidino-2-phenylindole (dapi) and propidium iodide, was developed by using several different isolates of oocysts. correlation of this assay with viability measured by in vitro excystation was highly statistically significant, with a calculated correlation coefficient of 0.997. in this research, two similar excystation protocols were utilized, and no significant differ ... | 1992 | 1482174 |
| survival of cryptosporidium parvum oocysts under various environmental pressures. | the survival of various isolates of cryptosporidium parvum oocysts under a range of environmental pressures including freezing, desiccation, and water treatment processes and in physical environments commonly associated with oocysts such as feces and various water types was monitored. oocyst viability was assessed by in vitro excystation and by a viability assay based on the exclusion or inclusion of two fluorogenic vital dyes. although desiccation was found to be lethal, a small proportion of o ... | 1992 | 1482175 |
| efficacy of activated sludge in removing cryptosporidium parvum oocysts from sewage. | primary clarifier effluent (procedure b) and final effluent (procedure a) from a wastewater treatment plant were enriched with cryptosporidium parvum oocysts obtained from the feces of naturally infected calves. procedure b samples alone were subjected to a laboratory simulation of activated-sludge treatment. coccidium-free neonatal cd-1 mice were then inoculated intragastrically with procedure a or procedure b samples. seven days after inoculation, the intensity of oocyst infection in procedure ... | 1992 | 1482177 |
| [efficacy of paromomycin sulfate (humagel) in an aids infected patient with intestinal cryptosporidiosis]. | | 1992 | 1493891 |
| pathogenesis of intestinal cryptosporidiosis in conventional and gnotobiotic piglets. | the pathogenesis of intestinal cryptosporidiosis was studied in 52 conventionally reared and 20 gnotobiotically reared piglets by inoculation with different doses of cryptosporidium parvum oocysts. the prepatent period of c. parvum in both groups of animals were variable, depending on the number of oocysts administered. the patent period of c. parvum in conventionally reared piglets was 8 or 9 days; in gnotobiotic piglets cryptosporidia were found in feces until day post infection (dpi) 16, when ... | 1992 | 1496800 |
| resistance of severe combined immunodeficient mice to infection with cryptosporidium parvum: the importance of intestinal microflora. | cryptosporidium parvum is a protozoan parasite which colonizes intestinal epithelium, causing transient diarrheal illness in immunocompetent hosts and severe chronic disease in immunocompromised hosts. we examined the resistance of severe combined immunodeficient mice, either bearing intestinal flora or germfree, to intestinal infection with c. parvum. infection was not readily detected in flora-bearing adult severe combined immunodeficient mice until 5 to 7 weeks following oral challenge with c ... | 1992 | 1500156 |
| immunology of giardia and cryptosporidium infections. | giardiasis and cryptosporidiosis occur in immunocompetent persons, and as opportunistic infections in immunocompromised individuals. the causative organisms of giardiasis (giardia lamblia) and cryptosporidiosis (cryptosporidium parvum) have markedly different life cycles, but currently available evidence suggests that intestinal antibody plays a major part in host protection against both parasites. in the case of g. lamblia, the evidence points to a role for intestinal antitrophozoite antibody i ... | 1992 | 1500734 |
| effectiveness of dehydroepiandrosterone in reduction of cryptosporidial activity in immunosuppressed rats. | the aim of this study was to evaluate the efficacy of the immunomodulator dehydroepiandrosterone in the treatment of cryptosporidiosis in glucocorticoid-induced immunosuppressed rats. a significant reduction in cryptosporidial activity occurred in treated versus untreated rats as assessed by oocyst shedding intensities and examination of parasite colonization in the small intestine. | 1992 | 1534212 |
| dehydroepiandrosterone-induced reduction of cryptosporidium parvum infections in aged syrian golden hamsters. | cryptosporidiosis, a parasitic disorder caused by cryptosporidium parvum, is frequently a fulminating and life-threatening disease in immunocompromised hosts. the immune status of the host plays a critical role in determining the length and severity of the disease. dehydroepiandrosterone (dhea) is an immunomodulator that has been demonstrated to upregulate immune parameters. ten aged (20-24 mo) syrian golden hamsters were treated with dhea for 7 days prior to intragastric inoculation with 1 x 10 ... | 1992 | 1534580 |
| isolation, sequence and molecular karyotype analysis of the actin gene of cryptosporidium parvum. | actin is an ubiquitous and highly conserved microfilament protein which is hypothesized to play a mechanical, force-generating role in the unusual gliding motility of sporozoan zoites and in their active penetration of host cells. we have identified and isolated an actin gene from a cryptosporidium parvum genomic dna library using a chicken beta-actin cdna as an hybridization probe. the nucleotide sequences of two overlapping recombinant clones were identical and the amino acid sequence deduced ... | 1992 | 1542305 |
| experimental cryptosporidium parvum infections in immunosuppressed adult mice. | five strains of adult mice were immunosuppressed with the synthetic glucocorticosteroid dexamethasone (dex), administered either orally or intraperitoneally. the strains of mice used were c57bl/6n, dba/2n, cba, c3h/hen, and balb/cann. all mice were evaluated for susceptibility to cryptosporidium parvum after intragastric inoculation with 10(6) oocysts per mouse. the dba/2n, cba, c3h/hen, and balb/cann mice given 0.25 micrograms of dex per g per day orally (the dose and route previously used to i ... | 1992 | 1548087 |
| cryptosporidium parvum: experimental infections in aged syrian golden hamsters. | young (8-12 weeks) and aged (20-24 months) syrian golden hamsters were intragastrically inoculated with cryptosporidium parvum oocysts to compare the susceptibility to cryptosporidiosis between these two age groups. oocyst shedding was significantly more intense in the aged than in the young hamsters. moreover, parasite colonization of the small intestine was observed in the aged but not the young hamsters. splenocytes from aged hamsters exhibited significantly lower t, b, and natural killer cel ... | 1992 | 1552209 |
| paromomycin inhibits cryptosporidium infection of a human enterocyte cell line. | cryptosporidium parvum is a protozoan parasite that causes severe enteritis in patients with aids for which there is no effective therapy. paromomycin is a nonabsorbable aminoglycoside that is effective in the treatment of other intestinal protozoa. the ability of paromomycin to inhibit c. parvum infection of a differentiated human enterocyte cell line was evaluated in vitro. paromomycin concentrations ranging from 50 to 5000 micrograms/ml inhibited infection at 24 h in a dose-dependent fashion. ... | 1992 | 1552210 |
| new findings during cryptosporidium parvum development in the chick embryo. | | 1992 | 1552219 |
| comparative study of the antigenic composition of oocyst isolates of cryptosporidium parvum from different hosts. | an investigation was made of the antigenic composition of oocyst isolates of cryptosporidium parvum by immunoblotting using rabbit polyclonal or murine monoclonal antibodies (moabs) developed against this parasite. using the polyclonal antibodies in blots, a common antigenic profile was obtained from a number of human oocyst isolates from aids patients and immunocompetent children in the uk and portugal. antigenic differences were observed, however, between a human isolate from turkey and these ... | 1992 | 1570174 |
| cryptosporidium parvum in calves: kinetics and immunoblot analysis of specific serum and local antibody responses (immunoglobulin a [iga], igg, and igm) after natural and experimental infections. | fecal and serum anti-cryptosporidium parvum immunoglobulin a (iga), igm, and igg were monitored by an enzyme-linked immunosorbent assay after experimental and natural infection of calves with c. parvum. although all experimentally infected calves showed high levels of colostral antibodies in the feces, they acquired c. parvum infection. three of five animals died. calves which acquired natural infection showed only diarrhea. levels of colostral coproantibodies dropped quickly. experimental infec ... | 1992 | 1587597 |
| identification and initial characterization of five cryptosporidium parvum sporozoite antigen genes. | cryptosporidium parvum, an apicomplexan parasite of gastrointestinal epithelial cells, causes severe disease in persons with aids and is a common cause of self-limited diarrhea in children, animal handlers, and residents of developing countries. no approved therapy exists; in research studies, however, hyperimmune bovine colostrum raised to cryptosporidium oocysts and sporozoites has eradicated disease or decreased parasite burden in some aids patients. although the protective antigens recognize ... | 1992 | 1587601 |
| activity of sulfadimethoxine against cryptosporidiosis in dairy calves. | of 13 neonatal calves inoculated orally with 1.5 x 10(6) oocysts of cryptosporidium parvum, 7 in group a were fed 5-g boluses of sulfadimethoxine for 21 consecutive days beginning 1 day before infection, and 6 calves in group b were untreated controls. calves in group a had diarrhea for 6-18 days (mean = 11 days); those in group b had diarrhea for 4-14 days (mean = 8.7 days). the severity of diarrhea, based on a daily numerical scoring system, was similar for both groups. calves in group a shed ... | 1992 | 1597803 |
| in vitro multiplication of cryptosporidium parvum in mouse peritoneal macrophages. | cryptosporidium parvum of bovine origin was developed in vitro in unsensitized mouse peritoneal macrophages. macrophages growing in rpmi medium were infected with sporozoites or with oocysts, and after staining infections were studied by light microscopy. a high parasitic index was obtained with multiple infections occurring commonly. this is a simple method for the study of cryptosporidium biology, and for in vitro assays of pharmacological activity. | 1992 | 1615629 |
| pcr cloning and nucleotide sequence determination of the 18s rrna genes and internal transcribed spacer 1 of the protozoan parasites cryptosporidium parvum and cryptosporidium muris. | the genes encoding 18s rrna and internal transcribed spacer 1 (1ts1) of cryptosporidium parvum and cryptosporidium muris were amplified from oocysts by pcr utilizing primers complementary to conserved regions of the 5' end of 18s and 5.8s rrna. pcr products were cloned and the complete nucleotide sequences of two clones of each cryptosporidium species were determined. the 18s rrna genes of c. parvum and c. muris showed more than 99% sequence identity. | 1992 | 1627648 |
| immune responses to cryptosporidium muris and cryptosporidium parvum in adult immunocompetent or immunocompromised (nude and scid) mice. | adult murine models of cryptosporidium infection involving cryptosporidium muris and c. parvum were used to study immunity to cryptosporidiosis in the mammalian host. immunocompetent balb/c or c57bl/6 mice developed a highly patent infection with the rn 66 strain of c. muris but overcame the infection and were immune to reinfection. in contrast, severe combined immunodeficiency (scid) mice or nude mice had a chronic infection lasting at least 109 days. the development of the c. muris infection a ... | 1992 | 1639500 |
| cross-reactivity of polyclonal serum antibodies generated against cryptosporidium parvum oocysts. | polyclonal antibodies raised against cryptosporidium parvum oocysts were found to cross-react with eimeria spp. oocyst antigens in an indirect immunofluorescence assay, and sera from eimeria spp.-infected lambs reacted with some antigens from sonicated c. parvum oocysts (between 29 to 30 and 66 to 69 kda) by western blot (immunoblot). no cross-reaction was observed with cystozoites of toxoplasma and sarcocystis spp. these results show the existence of epitopes common to c. parvum and various eim ... | 1992 | 1639512 |
| cryptosporidiosis in adult and neonatal mice with severe combined immunodeficiency. | cryptosporidium parvum causes protracted diarrhoea in immunodeficient hosts. to characterize the role that t and b lymphocytes play in the eradication of the parasite from the intestinal mucosa, the course of infection in mice with severe combined immunodeficiency (scid) was studied. twenty-nine scid and 26 balb/c adult mice received 10(6) oocysts intragastrically. the course of infection in the two strains was similar until 2 months after inoculation, when moderate numbers of organisms were ide ... | 1992 | 1644934 |
| activity of azithromycin against cryptosporidia in immunosuppressed rats. | dexamethasone-immunosuppressed rats infected with cryptosporidium parvum were used to assess the macrolides azithromycin and spiramycin for anticryptosporidial activity. azithromycin consistently prevented ileal infection, while spiramycin was ineffective. the anticryptosporidial activity of azithromycin was dose-related, 200 mg/kg/day being the minimum dose that prevented infection. therapeutically, azithromycin eliminated an established overt infection of the small intestine in immunosuppresse ... | 1991 | 1645382 |
| cryptosporidiosis facilitated by murine retroviral infection with lp-bm5. | lp-bm5 murine leukemia virus infection caused alterations in splenic t cell subsets in adult c57bl/6 female mice. prolonged infection resulted in increased immunosuppression and a concomitant decreased resistance to cryptosporidium parvum infection. significant cryptosporidium colonization of the intestinal villi was seen 10 days after oral challenge in mice infected with murine retrovirus for 3 months but not in non-virally infected controls. parasite numbers per villus of retrovirally infected ... | 1991 | 1654357 |
| chemotherapeutic effect of azithromycin and lasalocid on cryptosporidium infection in mice. | prednisolone-immunosuppressed mice (icr, 7-wk-old female) were each inoculated with 1 x 10(5) oocysts of cryptosporidium parvum. medication with azithromycin (400 mg/kg/day) or lasalocid (64, or 128 mg/kg/day) was started 13 h after inoculation and continued for 3 days. the number of oocysts discharged by each mouse was calculated on days 4-12 post-inoculation. compared with non-medicated controls, oocyst production by the medicated mice was markedly reduced; some mice did not discharge oocysts ... | 1991 | 1667931 |
| restriction fragment length polymorphism analysis of cryptosporidium parvum isolates of bovine and human origin. | cryptosporidium parvum oocysts isolated from different hosts and geographical areas were compared by restriction endonuclease analysis of repetitive dna: iowa (bovine), florida (bovine), new york (bovine), peru (human), brazil (human), and mexico (human). southern blot hybridization analysis was performed using the restriction endonuclease enzyme eco ri and the dna probe pv47-2. the probe hybridized with 18 bands present in all the isolates. the brazilian, mexican, and peruvian human isolates ha ... | 1991 | 1687825 |
| in vitro murine lymphocyte blastogenic responses to cryptosporidium parvum. | spleen and mesenteric lymph node lymphocytes from both cryptosporidium parvum-exposed and unexposed mice were cultured with antigen (ag) prepared from c. parvum oocysts. spleen lymphocytes from oral-, intraperitoneal-, or oral + intraperitoneal-exposed mice did not respond significantly (p greater than 0.05) to ag stimulation. spleen lymphocytes from multioral-exposed mice, however, demonstrated significant (p less than or equal to 0.01) ag-specific blastogenesis. mesenteric lymph node lymphocyt ... | 1990 | 1693675 |
| identification of a 15-kilodalton surface glycoprotein on sporozoites of cryptosporidium parvum. | an immunoglobulin a monoclonal antibody (mab5c3) was developed against a 15-kda surface glycoprotein (gp15) of cryptosporidium parvum sporozoites. indirect immunofluorescence and colloidal gold immunoelectron microscopy revealed that the antibody reacted with both the sporozoite and merozoite surface plasma membranes. on western immunoblots, mab5c3 binding was found to be strongly inhibited when 200 mm n-acetylglucosamine was used as a competing sugar. n-acetylgalactosamine inhibited binding of ... | 1991 | 1705238 |
| characterization of microneme antigens of cryptosporidium parvum (protozoa, apicomplexa). | two monoclonal antibodies (mabs) raised against purified excysted oocysts and sporozoites of cryptosporidium parvum reacted in an immunofluorescence assay with antigens located at the anterior pole of the zoites. on western blots of purified oocysts, these mabs reacted with a series of bands between 210 and 40 kda; several of these bands were recognized by both mabs; others were specific. one mab (tou) did not react after periodic acid treatment and was therefore considered to recognize a carboh ... | 1991 | 1708357 |
| in vitro activities of lytic peptides against the sporozoites of cryptosporidium parvum. | cryptosporidium parvum is a protozoan parasite that causes mild to severe diarrheal disease in animals and humans. there are currently no effective chemotherapeutic agents available for the treatment of cryptosporidiosis. recent studies have described small, naturally occurring antimicrobial lytic peptides with antiprotozoal activities. in the present study, the anticryptosporidial activities of three synthetic lytic peptides were determined in an in vitro sporozoite susceptibility assay. sporoz ... | 1991 | 1708975 |
| characteristics and specificity of hybridoma antibodies against oocyst antigens of cryptosporidium parvum from man. | hybridoma antibodies (habs) against oocyst antigens of a human isolate of cryptosporidium parvum were developed by fusion of sp2/0 mouse myeloma cells and spleen cells from balb/c mice immunized with oocyst homogenates. in an indirect immunofluorescence antibody test (ifat), using as antigen a mixture of air-dried sporozoites and oocysts, habs labelled either the oocyst wall or areas of the sporozoite, including the whole organism, the entire surface, a polar region or the interior. most of the ... | 1991 | 1712929 |
| threshold of detection of cryptosporidium oocysts in human stool specimens: evidence for low sensitivity of current diagnostic methods. | to determine the minimum number of cryptosporidium oocysts that can be detected in stool specimens by diagnostic procedures, stool samples seeded with known numbers of cryptosporidium parvum oocysts were processed by the modified formalin-ethyl acetate (fea) stool concentration method. fea concentrates were subsequently examined by both the modified cold kinyoun acid-fast (af) staining and fluorescein-tagged monoclonal antibody (immunofluorescence [if]) techniques. oocysts were more easily detec ... | 1991 | 1715881 |
| characterization and immunolocalization of an oocyst wall antigen of cryptosporidium parvum (protozoa: apicomplexa). | a monoclonal antibody (ow-igo) raised against purified excysted oocysts of cryptosporidium parvum reacted in an immunofluorescence assay with the oocyst wall. the corresponding antigen was localized by immunoelectron microscopy in fibrillous material present in the parasitophorous vacuole of developing macrogametes and in the wall of both single and double layered sporulating oocysts. gold particles were also detected over electron-lucent vesicles of the macrogametes by immunoelectron microscopy ... | 1991 | 1720886 |
| sporozoites and merozoites of cryptosporidium parvum share a common epitope recognized by a monoclonal antibody and two-dimensional electrophoresis. | sporozoites and merozoites of cryptosporidium parvum were analyzed for the presence of a 15 kda surface antigen using a monoclonal antibody probe. both were found to possess the antigen by immunofluorescence, and further analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis confirmed these observations. when separated by two-dimensional electrophoresis the isoelectric point was found to be similar, with major spots at 4.25 and minor spots at 4.15. | 1991 | 1726328 |
| dna sequences for the specific detection of cryptosporidium parvum by the polymerase chain reaction. | the objective of this project was to construct specific and sensitive molecular probes and amplification primers for cryptosporidium parvum that could be used in diagnosis, retrospective tissue studies, and in epidemiologic surveys. whole genomic dna was extracted from oocysts of c. parvum purified from human and bovine feces. a genomic library was constructed in plasmid puc18 and propagated in escherichia coli dh5 alpha. transformants were screened by colony hybridization and autoradiography. t ... | 1991 | 1763795 |
| cryptosporidium parvum: investigation of sporozoite excystation in vivo and the association of merozoites with intestinal mucus. | enteric cryptosporidiosis was studied in the small intestine of five-day-old sucking mice after infection with 10(6) cryptosporidium parvum oocysts. it was shown that excystation and the majority of subsequent endogenous stages occurred predominantly in the ileum. during the first three days of infection the number of merozoites collected in ileal washings increased over 100-fold to approximately 10(6) merozoites per mouse on the third day. in contrast to control mice, wash fluid from infected m ... | 1991 | 1780579 |
| a comparative study on the biology of cryptosporidium sp. from guinea pigs and cryptosporidium parvum (apicomplexa). | cryptosporidium sp. from guinea pigs and c. parvum were compared morphologically, electrophoretically, and for the ability to infect suckling mice. oocysts from guinea pigs measured 5.4 x 4.6 (4.8-5.6 x 4.0-5.0) microns and had a shape index (length/width) of 1.17 (1.04-1.33). oocysts of c. parvum were similar and measured 5.2 x 4.6 (4.8-5.6 x 4.2-4.8) microns with a shape index of 1.16 (1.04-1.33). all suckling mice inoculated with oocysts of c. parvum became infected, whereas most, but not all ... | 1991 | 1806211 |
| cryptosporidium infections in inbred strains of mice. | cryptosporidium, a protozoan parasite of man and animals, is an important etiological agent of diarrhea throughout the world, particularly in children and immunocompromised individuals such as aids patients. unfortunately, because of the lack of both in vivo laboratory models and reliable in vitro parasite culture systems, virtually nothing is known about the immunological events occurring during disease. in order to identify reliable animal models for infection, we studied c. parvum infections ... | 1991 | 1818124 |
| susceptibility dynamics in neonatal balb/c mice infected with cryptosporidium parvum. | balb/c mice were infected as neonates and at different ages to study the susceptibility dynamics in this animal model to cryptosporidium parvum. when 4-day-old animals were infected with 10(5) c. parvum oocysts, parasites were detected in the terminal ileum when the mice became 14-25 days old (10-21 days post-infection [pi]). the percentage of animals positive for parasites was 100% up to the age of 19 days (15 days pi) but decreased immediately thereafter until no parasites were detected in 26- ... | 1991 | 1818125 |
| an immunosuppressed rat model of respiratory cryptosporidiosis. | a rat model is described in which animals develop respiratory cryptosporidiosis, a disease which is well documented in immunocompromised patients, especially those with aids. our present lack of knowledge of the pathophysiology and immunology of cryptosporidium parvum respiratory infections warrants the development of a laboratory animal model. lewis rats immunosuppressed by subcutaneous injection of methylprednisolone acetate and inoculated intratracheally with 10(6) c. parvum oocysts developed ... | 1991 | 1818128 |
| cryptosporidium parvum life cycle in suckling mice: a nomarski interference-contrast study of a human-derived strain. | cryptosporidiosis has emerged as one of the life-threatening opportunistic enteric infections in hiv-infected persons. to date, cryptosporidium parvum is known to infect man via person-to-person or zoonotic transmission. we studied the sequential stages of the life cycle of c. parvum by normarski interference-contrast microscopy in fresh gut specimens of newborn mice, infected with a strain derived from an aids patient with cryptosporidial diarrheal enteritis. many 4- to 5-day-old suckling balb/ ... | 1991 | 1818130 |
| 566c80, an antimalarial hydroxynaphthoquinone with broad spectrum: experimental activity against opportunistic parasitic infections of aids patients. | hydroxynaphthoquinone 566c80 was synthesised and initially developed as an antimalarial with potent activity against drug-resistant strains of the human malaria parasite, plasmodium falciparum. subsequent studies have revealed that in addition, this compound has experimental activity, both in vitro and in vivo, against pneumocystis carinii and toxoplasma gondii; the data obtained thus far for cryptosporidium parvum are equivocal. currently 566c80 is being assessed clinically not only against mal ... | 1991 | 1818143 |
| hemolytic properties of lytic peptides active against the sporozoites of cryptosporidium parvum. | cryptosporidium parvum is a protozoan parasite that causes mildto-severe diarrheal disease in animals and humans. there are currently no effective chemotherapeutic agents available for the treatment of cryptosporidiosis. recently, small, naturally occurring antimicrobial lytic peptides with anti-protozoal activities have been described. in the present study, we compare the in vitro anti-cryptosporidial activities of synthetic lytic peptides and their corresponding hemolytic activities after a 30 ... | 1991 | 1818150 |
| characterization of anti-cryptosporidium iga antibodies in sera from immunocompetent individuals and hiv-infected patients. | human antibody response to cryptosporidium parvum has been previously shown as involving immunoglobulin (ig)m and igg isotypes. the interest in anti-cryptosporidial iga antibody response has been recently stimulated by studies on the therapeutic effects of secretory iga antibodies to cryptosporidium in animal models and in patients. in the present study, isotypes of serum anti-cryptosporidium antibodies have been characterized in donors of the following categories: (a) healthy adults, (b) health ... | 1991 | 1818157 |
| effect of hyperimmune bovine colostrum raised against cryptosporidium parvum on infection of guinea pigs by cryptosporidium wrairi. | oocysts shedding was markedly reduced in guinea pigs inoculated intraintestinally with cryptosporidium wrairi sporozoites that had been incubated with hyperimmune bovine colostrum raised to c. parvum when compared with shedding in guinea pigs inoculated with sporozoites incubated in either non-immune bovine colostrum or buffered saline. however oocyst shedding was apparently not reduced in guinea pigs inoculated by gavage with oocysts of c. wrairi and subsequently treated twice daily per os with ... | 1991 | 1818160 |
| characterization of a cryptosporidium parvum sporozoite glycoprotein. | polyclonal and monoclonal antibodies directed against cryptosporidium oocysts or sporozoites were developed to identify and characterize sporozoite pellicle and apical complex antigens. a very large glycoprotein of cryptosporidium sporozoites was identified by three monoclonal antibodies that also reacted with intracellular merozoites. the glycoprotein was also identified by polyclonal antibodies that were affinity-purified on nitrocellulose-bound recombinant proteins expressed by four lambda gt ... | 1991 | 1818168 |
| cryptosporidium merozoite isolation and purification using differential centrifugation techniques. | simple modifications to a recently published merozoite purification procedure (bjorneby et al., j. immunol. 145:298, 1990) increased yields 3- to 5-fold. calves were infected with 2.5 x 10(8) cryptosporidium parvum oocysts and sacrificed 65 h post-infection. the ilium and caecum were removed. the tissue was sieved through a large strainer (2 mm2) to produce a homogeneous suspension. red blood cells were removed by differential centrifugation (600 g); merozoites remained in the supernatant. the m ... | 1991 | 1818170 |
| in vitro screening of therapeutic agents against cryptosporidium: hyperimmune cow colostrum is highly inhibitory. | an in vitro model of cryptosporidium parvum infection was developed utilizing an adherent human intestinal epithelial cell line ht29.74. the efficacy of potential immunologic therapy in the form of cryptosporidium-specific hyperimmune bovine colostrum was evaluated for the ability to inhibit in vitro infection. oocysts were purified from stool of chronically infected aids patients. hyperimmune colostrum obtained from cows immunized with cryptosporidium and nonimmune conventional colostrum were e ... | 1991 | 1818181 |
| anti-cryptosporidial drug activity screened with an immunosuppressed rat model. | cryptosporidium parvum, a coccidian parasite can cause mild or severe self-limiting diarrhea in immunocompetent humans, but chronic and life-threatening in immunocompromised individuals. an immunosuppressed rat model with persistent cryptosporidiosis was used to investigate the anti-cryptosporidial activity of drugs. using curative procedures, no activity was found with 6 antibiotics assayed, including spiramycin (31-100%). mepacrine at a dose of 100 mg/kg had mild activity (19%), while lasaloci ... | 1991 | 1818183 |
| production and preparation of hyperimmune bovine colostrum for passive immunotherapy of cryptosporidiosis. | pregnant cows were immunized to produce hyperimmune bovine colostrum (hbc) by intramuscular injection or intramammary infusion (ti) followed by 3 successive ti boosters with cryptosporidium parvum (cp) oocyst antigen mixed with freund's (f) or ribi (r) adjuvant. control cows received no cp. colostrum from all cows was skimmed of butterfat and tested for specific anti-cp immunoglobulin isotypes by elisa. the hbc from cp-f and cp-r immunized cows had igg1 titers exceeding 1:400,000 and 1:800,000, ... | 1991 | 1818191 |
| hyperimmune hens as a novel source of anti-cryptosporidium antibodies suitable for passive immune transfer. | leghorn hens were subcutaneously immunized with 25 micrograms of cryptosporidium parvum oocyst emulsified in freund's complete adjuvant. a booster dose was injected 5 weeks later. anti-cryptosporidium activities of yolks and sera measured by an enzyme-linked immunosorbent assay (elisa), demonstrated high levels in both sera and egg yolks which persisted for at least 17 wk. preparations from yolks with high, medium and low anti-cryptosporidium elisa activities were used in a neonatal mouse model ... | 1991 | 1818193 |
| identification and isolation of cryptosporidium parvum genes encoding microtubule and microfilament proteins. | microtubules and microfilaments are highly conserved cytoskeletal polymers hypothesized to play essential biomechanical roles in the unusual gliding motility of apicomplexan zoites and in their invasion of, and development within, host epithelial cells. we have identified and isolated cryptosporidium parvum genes encoding the microtubule proteins alpha- and beta-tubulin and the microfilament protein actin by screening a lambda gt11 c. parvum genomic dna library with degenerate oligonucleotide an ... | 1991 | 1818196 |
| amplification of a cryptosporidium parvum gene fragment encoding thymidylate synthase. | currently, there is no effective therapy for cryptosporidiosis and it is unclear why antifolate drugs which are effective treatments for infections caused by closely related parasites are not also effective against cryptosporidium parvum. in protozoa, the target of these drugs, dihydrofolate reductase (dhfr), exists as a bifunctional enzyme also manifesting thymidylate synthase (ts) activity and is encoded by a fused dhfr-ts gene. in order to prepare a probe to isolate the c. parvum dhfr-ts gene ... | 1991 | 1818199 |
| cryptosporidial infections in scid mice reconstituted with human or murine lymphocytes. | severe combined immunodeficient (scid) mice were experimentally infected with cryptosporidium parvum. adoptive transfer of balb/c thymocytes, spleen and bone marrow cells resulted in functional immunologic reconstitution followed by complete eradication of the cryptosporidial infection. additional scid mice were injected with human blood peripheral blood lymphocytes and were subsequently infected with c. parvum. the latter mice (scid-hu-pbl) were at least partially reconstituted with human lymph ... | 1991 | 1818204 |
| cryptosporidium parvum: in vitro cultivation in madin-darby canine kidney cells. | to facilitate studies of the biology of cryptosporidium parvum, we have developed an in vitro culture system using madin-darby canine kidney (mdck) cells as the host cell. oocysts or free sporozoites were incubated 37 degrees c with monolayers of mdck cells in supplemented rpmi 1640 medium and the cells were examined at various time intervals after initiation of the culture. high rates of infection (up to 90% of mdck cells) were achievable. sequential development of trophozoites, meronts, microg ... | 1991 | 1818215 |
| effects of carbohydrates and lectins on cryptosporidial sporozoite penetration of cultured cell monolayers. | cryptosporidium parvum first interacts with enterocytes when sporozoites penetrate the host plasma membrane. we have developed a shell vial assay using human embryonic intestine 407 cells and purified c. parvum sporozoites to study this process. sporozoites were incubated in culture medium with various carbohydrates and lectins, and the suspensions were then added to the cell monolayers. following incubation, the monolayers were fixed and stained and the number of schizonts were counted. no decr ... | 1991 | 1818216 |
| construction of genomic libraries of cryptosporidium parvum and identification of antigen-encoding genes. | genomic libraries have been constructed from bovine c. parvum dna in the lambda zap and lambda dash vectors. based on an estimated genome size of 2 x 10(4) kilobases (kb), each recombinant library contains greater than 10 genomic equivalents. the average recombinant size for the lambda zap library is 2.1 kb and for the lambda dash library is 14 kb. we have identified genes to major antigens recognized by hyperimmune bovine antiserum. these recombinants are currently being purified and characteri ... | 1991 | 1818217 |
| ultrastructural study of asexual development of cryptosporidium parvum in a human intestinal cell line. | the lack of a well-defined in vitro model of cryptosporidium infection has severely hampered research on the biology of parasitic invasion of the host cell and on intracellular development of the parasite. in vitro infection of the differentiated human enterocyte cell line ht29.74 was studied by electron microscopy to detect changes in parasite and host cell morphology. cryptosporidium oocysts obtained from aids patients were applied to a monolayer of cloned differentiated ht29.74 cells. parasit ... | 1991 | 1818219 |
| immunotherapy of cryptosporidiosis in immunodeficient animal models. | immunotherapy for persistent infection caused by cryptosporidium parvum was attempted in two immunodeficient animal models. balb/c athymic (nude) mice were infected with two oral doses of 2 x 10(7) c. parvum oocysts, and subsequently treated with monoclonal antibody (mab) 17.41 that neutralizes sporozoites and merozoites. persistent infection was established in all exposed mice. daily oral treatment with mab 17.41 for 10 days significantly reduced (p less than 0.005) the number of c. parvum orga ... | 1991 | 1818225 |
| isolation of parasites on fruits and vegetables. | the current fda method to recover parasites from fruits and vegetables is derived from procedures used to isolate parasitic protozoa from water. a 1kg portion of fruit or vegetable is divided into 200 g subportions. the subportions are sequentially processed in a sonic cleaning bath with 1.5 liters of detergent solution (1% sodium dodecyl sulfate, 0.1% tween 80) and sonicated for 10 minutes. as each subsample is removed, it is thoroughly drained. after this sonic treatment, the wash water is col ... | 1991 | 1822873 |
| effects of dexamethasone and dehydroepiandrosterone in immunosuppressed rats infected with cryptosporidium parvum. | treatment of rats immunosuppressed with dexamethasone and inoculated with cryptosporidium parvum oocysts were treated with dehydroepiandrosterone. a significant reduction in cryptosporidial activity was observed as determined by oocyst shedding and colonization of host tissue by parasites. dexamethasone treatment alone resulted in decreases in t-, b- and natural killer (nk) cell responses and antibody production that, with the exception of nk-cell activity, were all reversed after administration ... | 1991 | 1840147 |
| cryptosporidium parvum in cattle, sheep and pigs in galicia (n.w. spain). | infection by cryptosporidium parvum has been detected for the first time in cattle and swine in galicia (n.w. spain). the organisms were also found in one of 69 sheep examined. although in most cases the parasite was found in young diarrhoeic animals, its presence in asymptomatic mature cattle and piglets was also detected. | 1991 | 1858293 |
| interaction of cryptosporidium parvum and campylobacter jejuni in experimentally infected neonatal mice. | by the method of scanning electron microscopy (sem), the inner mucosal surface of the ileum, ceacum and colon was studied in inbred balb/c mice. two-day-old mice were infected with either 10(6) oocysts of cryptosporidium parvum and 10(8) cfu of porcine and human strains of the bacterium campylobacter jejuni or with a combination of both enteropathogens. pathological changes in infection with c. parvum were related to enterocytes and villous atrophy appeared. in infection with c. jejuni, patholog ... | 1991 | 1863320 |
| [electron microscopic research on cryptosporidia. iii. parasite-host relations]. | a study was made of the host-parasite relationship with cryptosporidium parvum (apicomplexa, sporozoa), which parasitizes the intestine of newborn rats experimentally infected with oocysts isolated from c. parvum-infected calves. the endogenous development of the parasite occurs extracytoplasmically in the microvillar compartment of the enterocytes. the formation of the extracytoplasmic parasitophorous vacuole (pv), like that surrounding the endogenous stages of c. parvum, is regarded as one of ... | 1991 | 1866791 |
| four years of cryptosporidiosis at garankuwa hospital. | cryptosporidiosis was first recognised at garankuwa hospital, a reference teaching hospital for mainly black patients near pretoria, south africa, in october 1985. since then 289/6870 specimens (4.21%) submitted to the routine stool laboratory have been found to contain cryptosporidium parvum oocysts. seasonal peaks were seen in late summer (january, february, march) and minimum case numbers were recorded during late winter (august, september). the disease was predominantly one of early childhoo ... | 1991 | 1885922 |
| cryptosporidiosis. | before 1982, only eight case reports of human cryptosporidiosis and fewer than 30 papers on cryptosporidium spp. appeared in the biomedical literature. at that time, cryptosporidiosis was thought to be an infrequent infection in animals and rarely an opportunistic infection in humans. the concept of cryptosporidium spp. as pathogens has changed dramatically within the past 8 years because of improved diagnostic techniques, increased awareness within the biomedical community, and the development ... | 1991 | 1889046 |
| persistent cryptosporidiosis in horses with severe combined immunodeficiency. | cryptosporidial infections were established in five young foals with severe combined immunodeficiency following oral administration of 10(8) cryptosporidium parvum oocysts. all foals shed oocysts (average of 8 x 10(6) to 2 x 10(8)/g of feces) until death. inflammation and c. parvum organisms were observed in the common bile duct, duodenum, jejunum, and ileum. since foals with severe combined immunodeficiency lack functional t and b lymphocytes and are incapable of antigen-specific immune respons ... | 1991 | 1894380 |
| [livestock manure as a vector for parasites--a report of experiences]. | analysing the results of own investigations and informations in literature a review is given about the role of manure specially in stables of high-intensity cattle and pig production as a vector for exogenic parasite stages. in the course of investigations--in most cases simulating practice conditions--so-called indicator germs were used as test material. in cattle stables manure is significant as a vector for eimeria species, cryptosporidium parvum, sarcocystis species, taenia saginata and fasc ... | 1991 | 1914947 |
| coypus (myocastor coypus) as a new host of cryptosporidium parvum (apicomplexa: cryptosporidiidae). | | 1991 | 1916538 |
| inhibition of cryptosporidium parvum in neonatal hsd:(icr)br swiss miceby polyether ionophores and aromatic amidines. | cryptosporidicidal effects of two polyether ionophores (maduramicin and alborixin), a fluorinated 4-quinolone (enrofloxacin), and three analogs of pentamidine were evaluated in a suckling mouse bioassay. treatment with all compounds except enrofloxacin and one of the pentamidine analogs [1,3-di(4-imidazolinophenoxy)propane] resulted in significant (p less than 0.05) reductions in oocyst excretion. | 1991 | 1929322 |
| asexual development of cryptosporidium parvum within a differentiated human enterocyte cell line. | unremitting diarrhea with malabsorption is associated with cryptosporidium parvum infection of the small intestine in patients with aids. the lack of a well-defined in vitro model of c. parvum infection has severely hampered research into the biology of cryptosporidial invasion of the host epithelial cell and development of new pharmacologic and immunologic therapies. the adherent human intestinal epithelial cell line ht29 when grown in glucose-free medium develops morphologic and functional cha ... | 1991 | 1987037 |
| susceptibility of mast cell-deficient w/wv mice to cryptosporidium parvum. | mast cell-deficient w/wv infant mice were similar to normal mice in their susceptibility to and recovery from infection with the intestinal protozoan cryptosporidium parvum. w/wv adult mice were significantly more susceptible to primary infection than were normal adult mice, but both groups recovered at a similar rate. | 1991 | 1987087 |
| cryptosporidium parvum infection in mice: inability of lymphoid cells or culture supernatants to transfer protection from resistant adults to susceptible infants. | the ability of murine lymphoid cells or culture supernatant fractions to transfer protection against cryptosporidium parvum was examined. spleen or mesenteric lymph node (mln) cells were taken from adult mice resistant to c. parvum and given either directly or following in vitro culture to infant mice. neither spleen or mln cells, nor cells or supernatant fractions from in vitro cultures transferred protection from resistant adult donors to susceptible infant recipients. these results may be due ... | 1991 | 1992090 |
| monoclonal antibody immunotherapy in nude mice persistently infected with cryptosporidium parvum. | three groups of congenitally athymic nude mice were persistently infected following oral administration of 2 x 10(7) cryptosporidium parvum oocysts. two groups were treated once daily for 10 days with either neutralizing monoclonal antibody (mab) 17.41 or an isotype control mab. the third group received no treatment. intestinal-infection scores were significantly decreased in nude mice treated with mab 17.41 compared with isotype control mab-treated and nontreated control groups (p less than 0.0 ... | 1991 | 1997419 |
| characterization of bovine cellular and serum antibody responses during infection by cryptosporidium parvum. | cellular and serum antibody responses of calves were monitored for 23 days after oral inoculation of the calves with oocysts of cryptosporidium parvum. in vitro blastogenic responses of peripheral blood lymphocytes were assessed after stimulation with a c. parvum preparation. specific lymphocyte blastogenic responses to the parasite were detected 2 days after inoculation. parasite-specific antibody titers were demonstrable 7 days after inoculation with oocysts and achieved peak levels 9 days aft ... | 1991 | 1997443 |
| anticryptosporidial activity is associated with specific sulfonamides in immunosuppressed rats. | dexamethasone-immunosuppressed rats infected with cryptosporidium parvum were used to assess 23 sulfonamides for anticryptosporidial activity. five of the compounds administered before the animals were inoculated with c. parvum oocysts reduced the severity of cryptosporidial infections in the rat model. two of the 5 agents with prophylactic activity, sulfadimethoxine and sulfamethazine, were effective also against an established infection, indicating that some sulfonamides may have therapeutic v ... | 1991 | 2010856 |
| immunofluorescent microscopical visualization of trails left by gliding cryptosporidium parvum sporozoites. | cryptosporidium parvum sporozoites that exhibited gliding motility in vitro were examined by immunofluorescence with anticryptosporidial monoclonal antibodies (mabs) for surface antigen deposition on poly-l-lysine-coated glass microscope slides. the mabs that revealed trails are specific for an immunodominant 23-kda antigen previously localized to the sporozoite surface. | 1991 | 2010865 |
| efficacy of halofuginone lactate against cryptosporidium parvum in calves. | the efficacy of halofuginone lactate against natural cryptosporidium parvum infection in 150 neonatal market calves of a mixed belgian breed was tested. the drug was administered orally in the milk replacer over a period of 3 to 14 days at doses ranging from 30 to 500 micrograms/kg of body weight. over a period of 4 weeks, the animals were examined twice a week for shedding of c. parvum oocysts and were scored semiquantitatively for diarrhea. weight gain was assessed after 2 and 4 weeks. subclin ... | 1991 | 2024962 |
| chronic cryptosporidium parvum infections in congenitally immunodeficient scid and nude mice. | severe combined immune deficient (scid) and athymic national institutes of health (nih)-iii (bg/nu/xid) mice were evaluated for susceptibility to cryptosporidium parvum infections as neonates and as adults after challenge with inocula of 5 x 10(4) and 1 x 10(6) oocysts/mouse, respectively. scid and nih-iii nude mice developed chronic infections that persisted over 12 weeks. cryptosporidial organisms were observed in the small and large intestines of all mice. colonization of the gallbladder and ... | 1991 | 2037795 |
| studies on cryopreservation of cryptosporidium parvum. | neonatal balb/c mice received oocysts or sporozoites of cryptosporidium parvum pretreated by a variety of cryopreservation protocols. histologic sections of infected and control mice were examined to determine if pretreated organisms established infection in the intestine. sporozoites were inoculated rectally, oocysts orally. freshly excysted sporozoites were frozen in hanks' balanced salt solution (hbss) containing dimethylsulfoxide (dmso) or glycerol at concentrations of 5%, 10%, or 15% at coo ... | 1991 | 2040948 |