Publications

incorporation of exogenous uracil by cryptosporidium parvum in vitro.	oocysts of cryptosporidium parvum were used to infect madin-darby bovine kidney cells. cultures were incubated in a reduced-oxygen atmosphere in candle jars or in a 5% co2-95% air atmosphere. at 72 h, parasites were quantitated microscopically and found to be enhanced 5.5-fold in the reduced-oxygen atmosphere. using candle jars, we then determined that c. parvum was amenable to [3h]uracil incorporation assays and easily quantitated with this method.	1991	2056042
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
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
cryptosporidiosis: pathogenesis and immunology.	cryptosporidium parvum is an increasingly recognized agent of intestinal infection in normal and immunocompromised humans, and in many other animals. the intraepithelial cell infection results in villous atrophy, mild submucosal inflammation, reduction of brush-border enzymes and a characteristic persistent watery diarrhea. the infection is self-limiting in immunocompetent hosts, probably because of specific acquired immunity; specific serum and secretory antibody responses develop that may be r ...	1992	15463522
cellular biology of cryptosporidium parvum.	with the emergence of cryptosporidium parvum as a major pathogen encountered in human and veterinary clinical practice, a need for increased knowledge of the cellular- and immuno-biology of this apicomplexan parasite has developed. initial work has used paradigms taken from other apicomplexans, especially plasmodium, toxoplasma and eimeria, as a starting point. in this article, carolyn petersen discusses the observation that in these organisms, molecular targets of antibodies (which have protect ...	1993	15463717
effects of preservatives on viability of cryptosporidium parvum oocysts.	potassium dichromate and formalin reduced the viability of cryptosporidium parvum oocysts as assessed by inclusion or exclusion of 4',6-diamidino-2-phenylindole (dapi) and propidium iodide (pi) and excystation. some formalin-treated oocysts containing dead sporozoites excluded pi; that this fluorogenic assay relies not solely upon exclusion of pi but also upon highlighting of sporozoite nuclei by dapi is reiterated.	1993	16349135
a new antigen of cryptosporidium parvum micronemes possessing epitopes cross-reactive with macrogamete granules.	three monoclonal antibodies (mabs) raised against purified excysted oocysts and sporozoites of cryptosporidium parvum reacted in an immunofluorescent assay with antigens located at the apical pole of the sporozoites. on western blots of oocyst extract, an antigen of 100 kda was recognized by the three mabs. periodic acid treatment abolished this reactivity, suggesting that the corresponding epitopes are carbohydrates. as determined by immunoelectron microscopy, the three mabs reacted with micron ...	1993	7682329
cloning and expression of a cdna encoding epitopes shared by 15- and 60-kilodalton proteins of cryptosporidium parvum sporozoites.	a cdna (cp15/60) encoding epitopes of cryptosporidium parvum 15- and 60-kda sporozoite proteins was isolated and expressed in escherichia coli toward the goal of developing an immunogen for producing high-titer anticryptosporidial colostrum. antisera prepared in rats to native c. parvum 15-kda protein and used to identify the cp15/60 bacteriophage clone recognized both 15- and 60-kda in vitro translation products derived from sporozoite rna. antisera specific for recombinant cp15/60 antigen reco ...	1993	7684726
[bacterial, viral and parasitic etiologies of acute infantile diarrhea in a rural senegal].	we have studied the incidence of parasites, viruses and bacteria associated with acute infantile diarrhea in rural senegal. among parasitoses, cryptosporidium parvum (7.7%) is the most frequent, followed by entamoeba histolytica (5.1%). the first bacteriological etiologic agent is escherichia coli (20.9%). rotavirus are also frequently isolated (14.7%). prevalence of pathogens is higher: among children over 6 months and under two years old, among children either with mixed feeding or weaned, dur ...	1993	7758380
role of cd4+ th1- and th2-cell-secreted cytokines in cryptosporidiosis.	cryptosporidium parvum is now recognized as an important gastrointestinal pathogen around the world. unfortunately, control measures for cryptosporidiosis are currently not well defined and very little is known about the immunological events relevant to the control of infection. cytokine depletion experiments were conducted by injecting adult balb/c mice with monoclonal antibodies directed to il-2, il-4, and il-5, prior and during c. parvum infection. faecal oocyst excretion and intestinal paras ...	1993	7912219
cryptosporidiosis in poland: clinical, epidemiologic and parasitologic aspects.	stool samples from 692 children hospitalized with symptoms of gastroenteritis, were examined for cryptosporidium parvum. the oocysts were found in 17 (2.4%) children. there was no association with age, sex or location of household. however, relatively higher rate of oocyst exclusion was found among 2-month- to 3-year-old groups (50%) and among children from villages (43%). six children from the group of infected were additionally screened for general immunocompetence. four of these exhibited sig ...	1993	8013931
antigenic characterization of human isolates of cryptosporidia.	isolates of cryptosporidia from immunodeficient patients and from immunocompetent children suffering from diarrhoea were sources for preparation of antigens. altogether, antigens from 21 isolates were obtained, 19 from children and 2 from aids patients. with one exception, all children were under 4 years old and most of them were between 1 and 2 years old. the probable source of infection was found in 11 cases. in 8 cases, as well as in both aids patients, the source of infection was not determi ...	1993	8013932
human monoclonal antibodies against cryptosporidium parvum generated by hypo-osmolar electrofusion.		1993	8036749
[experimental and clinical study on cryptosporidiasis. iii. ultrastructural observation on cryptosporidium in immunosuppressed mice].	the ultrastructure of cryptosporidium parvum, which parasitized on the surface of the intestine of the immunosuppressed mice, was studied by transmission electron microscopy. the parasite was enveloped by the parasitophorous vacuole developed from the host epithelial cell. an electron dense band was found at the attachment site between the cryptosporidium and the host cell. at the attachment site, the cytoplasma membrane of cryptosporidium appeared in the form of many membranous folds, and conta ...	1993	8082271
is human cryptosporidiosis a zoonotic disease?		1993	8099404
is human cryptosporidiosis a zoonotic disease?		1993	8101344
significance of small numbers of cryptosporidium sp oocysts in water.		1993	8101345
requirements for cd4+ cells and gamma interferon in resolution of established cryptosporidium parvum infection in mice.	the importance of cd4+ cells and gamma interferon (ifn-gamma) in the resolution of established cryptosporidium parvum infection was investigated with a murine model of cryptosporidiosis in severe combined immunodeficient (scid) mice. c. parvum-infected scid mice were reconstituted with spleen cells from immunocompetent donors. the recipients were able to resolve their c. parvum infection by 17 days postreconstitution. treatment of reconstituted scid mice with either anti-cd4 monoclonal antibodie ...	1993	8103040
hiv-1 and parasitic infections in rural tanzania.	a sample of 300 sexually-active adults was selected at random from patients, from the rural area of malenga makali, tanzania, who were attending a dispensary because they had diarrhoea of at least 2 weeks' duration. the potential associations between the patient's health (in terms of the world health organization's clinical definition of aids), hiv-1 seroprevalence and malaria and other parasitic infections were then investigated. although, hiv-1 seroprevalence was 20.6% overall, the level of se ...	1993	8122920
[advances in immunological research on cryptosporidiosis].		1993	8174218
passive transfer of immunity against cryptosporidium infection in neonatal mice using monoclonal antibodies.	monoclonal antibodies (mab) against merozoites and sporozoites of the protozoan parasite cryptosporidium parvum were examined for potential modulation of cryptosporidial infections in vivo by daily oral mab administration to oocyst-inoculated neonatal mice. monoclonal-treated neonatal mice were sacrificed four and eight days post infection (pi). differences in infection rates were observed among the treatment groups at the p < 0.05 level. suckling mice treated daily with orally administered mixt ...	1993	8241081
anticryptosporidial activity of lasalocid and other ionophorous antibiotics in immunosuppressed rats.	the anticryptosporidial activities of three ionophorous antibiotics were assessed in dexamethasone-immunosuppressed rats infected with cryptosporidium parvum. when administered prophylactically, lasalocid prevented infection in a dose-dependent manner, whereas monensin and salinomycin were ineffective. therapeutically, lasalocid eliminated established overt infections of the intestine, although infection persisted in the common bile duct and intestinal infection recurred after lasalocid treatmen ...	1993	8245548
[drinking water and parasites].	entamoeba histolytica, giardia lamblia, cryptosporidium parvum, isospora belli, balantidium coli, and microsporidia spp. are cosmopolitan parasites. they often cause diarrheal diseases. the waterborn transmission of all these parasites is possible (41). surface water supplies used for drinking water are potential sources of contamination. giardia lamblia and cryptosporidium spp. have received great attention in industrialized countries during the last years because they are the etiological agent ...	1993	8253478
multiple oral inoculations with cryptosporidium parvum as a means of immunization for production of monoclonal antibodies.	oral immunization of suckling mice with cryptosporidium parvum results in a humoral response to a limited set of antigens. six-day-old balb/c mice were each inoculated orally with 1 x 10(6) viable oocysts and subsequently administered oral inoculations of 2 x 10(6) viable oocysts at 30 and 60 days following the primary infection. after 45 days, mice were boosted with 1 x 10(6) oocysts orally, plus soluble extracts equivalent to 2 x 10(6) and 1 x 10(6) oocysts given intravenously and intraperiton ...	1993	8262371
comparison of techniques for detecting antigens of giardia lamblia and cryptosporidium parvum in faeces.	to compare the use of commercial monoclonal antibody test systems--the giardia cel if test and the crypto cel if test--for the detection of giardia lamblia and cryptosporidium parvum antigens in faeces with conventional techniques.	1993	8331181
the immunosuppressive effects of dexamethasone administered in drinking water to c57bl/6n mice infected with cryptosporidium parvum.	the feasibility of immunosuppressing adult c57bl/6n mice by using dexamethasone in drinking water to sustain infections with cryptosporidium parvum was investigated. an ethanol-soluble formulation of dexamethasone (dex) was compared with a water-soluble (phosphated) formulation (dexp). dex or dexp was provided for mice ad libitum in drinking water at dosages of 10, 33, and 100 micrograms/ml. dex was also administered to mice by intraperitoneal injection at 125 micrograms/mouse/day. all mice were ...	1993	8331488
alcohol and murine acquired immunodeficiency syndrome suppression of resistance to cryptosporidium parvum infection during modulation of cytokine production.	the effects of inoculation of lp-bm5 murine leukemia retrovirus and chronic ethanol (5% v/v) ingestion on immunomodulation and cryptosporidium parvum infection in c57bl/6 female mice were evaluated. the intestinal mucosae of retrovirally immunosuppressed animals were heavily colonized by cryptosporidium parasites, and oocysts shedding in the feces persisted throughout the duration of the study. mortality was exacerbated by murine retrovirus infection alone and exacerbated with concomitant chroni ...	1993	8333581
[carriers and excretors of protozoa].	causative agents of intestinal infections in humans are about 10 pathogenic or facultative pathogenic species of protozoa of which giardia lamblia, entamoeba histolytica, cryptosporidium parvum and enterozytozoon bieneusi are discussed. g. lamblia from humans is morphologically indistinguishable from giardia isolates originating from several species of domestic and wild mammals. swiss giardia isolates of human, sheep, cattle and dog origin could be transmitted to giardia-free rodents and were ra ...	1993	8333895
gamma interferon functions in resistance to cryptosporidium parvum infection in severe combined immunodeficient mice.	severe combined immunodeficient (scid) adult mice are relatively resistant to cryptosporidium parvum infection, even though they are deficient in both t- and b-cell function. the requirement for gamma interferon (ifn-gamma) in this resistance was examined by treatment of these mice with monoclonal antibody to ifn-gamma. scid mice injected intraperitoneally with monoclonal anti-ifn-gamma 4 h before and three times weekly after challenge with c. parvum had heavy intestinal infections 3 weeks postc ...	1993	8335387
neutralisation of cryptosporidium parvum sporozoites by immunoglobulin and non-immunoglobulin components in serum.	sporozoites of cryptosporidium parvum were incubated in 1:10 dilutions of immune or non-immune, heat-inactivated lamb serum specimens or serum fractions. the infectivity of treated sporozoites was assessed by inoculating them, per rectum, into five-day-old rats followed by histological examination of their intestines at either three or five days after infection. the infectivity of sporozoites treated with heat-inactivated whole sera was greatly reduced. this neutralisation had both specific and ...	1993	8337483
induction of folds or sutures on the walls of cryptosporidium parvum oocysts and their importance as a diagnostic feature.	the proportion of oocysts of cryptosporidium parvum showing a fold on oocyst walls when incubated with either fluorescent monoclonal antibody or a surface-reactive fluorescent dye was increased by incubating suspensions of oocysts with dimethyl sulfoxide, sucrose, or hanks' balanced salt solution. further incubation of sucrose-incubated oocysts with water showed this to be a reversible phenomenon. oocysts demonstrating this fold after incubation in dimethyl sulfoxide were of the same viability a ...	1993	8368850
proliferative responsiveness of lymphocytes from cryptosporidium parvum-exposed mice to two separate antigen fractions from oocysts.	we assessed lymphoproliferative responsiveness of lymphocytes from the spleen and lymph nodes of inbred neonatal swr/j h-2q mice at various times postinoculation (pi) using cryptosporidium parvum oocysts. the lymphocytes were cultured in vitro with a water-soluble (so) and a water-insoluble (in) antigen fraction. the in fraction was prepared by solubilizing particulates, the sediment obtained after centrifuging disrupted oocysts, in urea. both fractions were characterized using silver stain and ...	1993	8372961
characterization and immunolocalization of a cryptosporidium protein containing repeated amino acid motifs.	the oocyst wall is one of the components that permits cryptosporidia both to survive in the environment and to retain infectivity. with the aim of identifying cryptosporidium proteins specifically expressed at the oocyst stage, we screened lambda gt11 genomic libraries of cryptosporidium parvum with both an oocyst antiserum and a specific genetic probe. we isolated, from distinct libraries, two overlapping clones containing an open reading frame encoding a 1,252-amino-acid polypeptide. the analy ...	1993	8388861
glycoside antibiotics alone and combined with tetracyclines for prophylaxis of experimental cryptosporidiosis in neonatal balb/c mice.	glycoside antibiotics including the macrolide antibiotics azithromycin, clarithromycin, and erythromycin and the aminoglycoside paromomycin were administered alone or combined with doxycycline, minocycline, or tetracycline to neonatal balb/c mice experimentally infected with cryptosporidium parvum. glycosides at 100 or 200 mg/kg of body weight and tetracyclines at 50 mg/kg of body weight were dissolved in dimethylsulfoxide (dmso), which was then diluted with phosphate-buffered saline (pbs) and g ...	1993	8392541
advances in the diagnosis of some parasitic diseases by monoclonal antibody-based enzyme-linked immunosorbent assays.	advances in diagnostic assays for parasitic diseases include the use of monoclonal antibodies (mabs) in antigen capture and competitive inhibition enzyme-linked immunosorbent assays (c-elisa). antigen capture elisas for anaplasma marginale and cryptosporidium parvum provide direct detection of these parasites during clinical disease, and the c-elisa format has been adapted for detection of anti-babesia equi, anti-a. marginale and anti-bluetongue virus antibodies. false-positive results may occur ...	1993	8400383
anti-cryptosporidium parvum antibodies inhibit infectivity in vitro and in vivo.	cryptosporidium parvum causes acute diarrhea in immunocompetent individuals and a severe life-threatening disease in immunocompromised individuals, including aids patients. no efficacious therapy for cryptosporidiosis has yet been reported. however, treatment of some patients with cryptosporidiosis with hyperimmune bovine colostrum has ameliorated or eliminated clinical symptoms. consequently, it is important to identify and characterize c. parvum antigens which are the targets of protective ant ...	1993	8406795
specific serum and local antibody responses against cryptosporidium parvum during medication of calves with halofuginone lactate.	fecal and serum anti-cryptosporidium parvum immunoglobulin a (iga), igm, and igg were monitored by an enzyme immunoassay in c. parvum-infected calves after medication with halofuginone lactate. in a first experiment, four groups of five 1-day-old colostrum-fed calves were inoculated with 10(6) oocysts of c. parvum. they were medicated with 0, 30, 60, or 120 micrograms of halofuginone lactate per kg from days 2 to 8 postinfection (p.i.). unmedicated calves passed large numbers of oocysts between ...	1993	8406835
microtubule inhibitors block cryptosporidium parvum infection of a human enterocyte cell line.	no effective therapy exists for cryptosporidium parvum, a coccidial protozoan parasite that causes severe diarrhea in patients with aids. the role of microtubules in parasite invasion of host cells was investigated by incubating 10(7) oocysts with a ht 29.74 cell line for 24 h in the presence of microtubule-disrupting drugs. the number of parasites per 1,000 cells was reduced by 77% (p < 0.001, n = 4) from 182 +/- 3 in untreated cells to 42 +/- 4 in cells treated with 10(-4) m colchicine. inhibi ...	1993	8406890
effect of orally administered monoclonal antibody on persistent cryptosporidium parvum infection in scid mice.	scid mice, persistently infected after exposure to 10(7) cryptosporidium parvum oocysts, were treated daily for 14 to 17 days with 0.4 mg of monoclonal antibody (mab) 17.41 administered by the oral route. mice receiving mab 17.41 shed significantly fewer (p < 0.005) c. parvum oocysts than scid mice receiving isotype control mab. intestinal (but not gastric) infectivity scores were also reduced for scid mice treated with mab 17.41 (p < 0.01).	1993	8406894
paromomycin is effective as prophylaxis for cryptosporidiosis in dairy calves.	of 16 experimentally infected neonatal dairy calves, 12 were fed paromomycin twice daily in their milk for 11 consecutive days beginning 1 day before oral inoculation with 1.5-2.0 x 10(6) oocysts of cryptosporidium parvum. four calves each in groups a, b, c, and d received total daily doses of 100, 50, 25, and 0 mg of paromomycin per kilogram of body weight, respectively. from birth until 28 days of age feces from each calf were examined for diarrhea, and oocysts were enumerated, rectal temperat ...	1993	8410552
[one more biological characteristic of coccidia in the genus cryptosporidium (sporozoa: apicocomplexa)].	suckling rats were used as a model host for our previous em studies of the endogenous development of cryptosporidium parvum isolated from spontaneously infected calves (beĭer e. a., 1990; beĭer, sidorenko, 1990). in the course of repeated infections it was noticed that the oocysts discharged by the recipient host (rat) were obviously larger than those in the donor's (calf's) isolates. keeping in mind the presumable taxonomic significance of coccidian oocysts as a constant and rather reliable too ...	1993	8414650
isoenzyme variation within the genus cryptosporidium.	soluble extracts of the oocysts of cryptosporidium parvum had demonstrable, but low, activities of malate dehydrogenase (mdh, ec. 1.1.1.37), carboxylesterase (es, ec 3.1.1.1) and lactate dehydrogenase (ldh, ec. 1.1.1.27) following thin-layer starch-gel electrophoresis. much higher activities of glucose phosphate isomerase (gpi, ec. 5.3.1.9) and phosphoglucomutase (pgm, ec. 2.7.5.1) were found, and zymograms of these two enzymes were used to characterise isolates of c. parvum from human, bovine, ...	1993	8415544
intestinal protozoa infections.	this article reviews important intestinal protozoal infections in cats. among intestinal protozoa, giardia and coccidia are the most important infections. giardiasis is a common problem in catteries, especially where young kittens run free on the floor. overcrowding and high humidity favour the survival and transmission of giardia. diagnosis is made by fecal examination by direct or concentration methods. metronidazole is the drug of choice for treating giardiasis. among the coccidial parasites, ...	1993	8421888
effect of ultraviolet disinfection of drinking water on the viability of cryptosporidium parvum oocysts.	demineralized water was enriched with a known number of cryptosporidium parvum oocysts obtained from fresh calf feces, which were purified and exposed to ultraviolet (uv) light (15,000 mw/sec) for different lengths of time. coccidium-free litters of cd-1 neonatal mice then were inoculated intragastrically with the treated water. seven days postinoculation mice were killed and c. parvum infection prevalence and intensity determined. in mice inoculated with c. parvum-enriched water that had been e ...	1993	8437060
assessment of candidate anticryptosporidial agents in an immunosuppressed rat model.	cryptosporidium parvum causes life-threatening diarrhea in immunocompromised patients, especially those with aids. the efficiency of currently proposed anticryptosporidial therapies is limited or doubtful. in this report, molecular candidates for curative or preventive activity were investigated in an immunocompromised rat model that mimics severe human cryptosporidiosis. no significant anticryptosporidial activity was observed when using sulfadoxine-pyrimethamine, quinacrine, trimethoprim-sulfa ...	1993	8440946
the effect of halofuginone lactate on experimental cryptosporidium parvum infections in calves.	the chemoprophylactic effects of halofuginone lactate were tested against calf experimental cryptosporidiosis. twenty 2-day-old calves, divided into four groups, were orally inoculated with 1 x 10(6) oocysts of cryptosporidium parvum. the infected control group was unmedicated whereas the three other groups were medicated with the drug at 30, 60 and 120 micrograms kg-1 day-1, respectively, for 7 days, from day (d) 2 to d8 post-inoculation (d 0 was inoculation day). the calves were weighed twice ...	1993	8447063
ultrastructural study of cryptosporidium development in madin-darby canine kidney cells.	transmission electron microscope studies have been made into phases of the life cycle of a bovine isolate of cryptosporidium cultured in vitro on madin-darby canine kidney cells. the cytoplasm of parasitized cells was noticeably altered, including marked vacuolization and the appearance of membrane structures close to the developing parasites. these changes suggest that the protozoan may release cytopathogenic factors.	1993	8447069
cryptosporidium parvum: culture in mdck cells.		1993	8454030
complete development of cryptosporidium parvum in a human endometrial carcinoma cell line.	sporozoites of cryptosporidium parvum, excysted from oocysts isolated from calves, were applied to monolayers of the human endometrial carcinoma cell line rl95-2. cells were grown as monolayers in 24-well plates at concentrations ranging from 5 x 10(4) to 1 x 10(5) rl95-2 cells per well. at 1 or 7 days postculturing, c. parvum sporozoites (ranging from 1 x 10(5) to 2 x 10(5) were added to the monolayers of rl95-2 cells. the cells were fixed and stained to estimate the extent of parasite coloniza ...	1993	8454353
cryptosporidium parvum infection after abrogation of natural killer cell activity in normal and severe combined immunodeficiency mice.	the role of natural killer (nk) cell activity in adult mice with severe combined immunodeficiency (scid mice) infected with cryptosporidium parvum oocytes was evaluated. adult balb/c and scid mice were inoculated intragastrically with 10(6) c. parvum oocysts after the administration of anti-asialo-gm1 or control normal rabbit serum. groups of animals were evaluated for splenic nk cell activity and examined histopathologically at 2, 4, and 6 wk postinfection. virtual elimination of splenic nk cel ...	1993	8459345
rapid differentiation of untreated, autoclaved and ozone-treated cryptosporidium parvum oocysts using dielectrophoresis.	a novel automated dielectrophoretic electrode apparatus and procedure was used to differentiate between untreated, autoclaved and ozone treated cryptosporidium parvum oocysts recovered from water. a freeze-frame video technique enabled images of oocysts to be captured when they collected at sites above and between the electrodes upon application of an electric field. the number of oocysts collecting could then be conveniently counted. varying the frequency of the applied electric field allowed t ...	1993	8469175
in vitro excystation of cryptosporidium parvum.	protocols for in vitro excystation of oocysts of cryptosporidium parvum, including different chemical pre-incubation steps, were compared to examine some of the biochemical triggers involved in excystation and to define an in vitro excystation protocol of a reproducibly high efficiency. pre-incubation steps which increased the permeability of the oocysts were found to enhance excystation dynamics and pre-treatment of oocysts with saliva was found to decrease the permeability and reduce excystati ...	1993	8479797
enhancement of resistance to cryptosporidium parvum by pooled bovine colostrum during murine retroviral infection.	the therapeutic efficacy of pooled bovine colostrum for the control of cryptosporidiosis was investigated during murine acquired immunodeficiency syndrome in female c57bl/6 mice. mice were infected with lp-bm5 murine leukemia retrovirus for four months and then inoculated with cryptosporidium parvum oocysts. persistent cryptosporidiosis was established in all retrovirus immunosuppressed mice, while control mice were refractory to infection. parasite colonization of intestinal villi was significa ...	1993	8480860
detection of oocysts and igg antibodies to cryptosporidium parvum in asymptomatic adult cattle.	infection by cryptosporidium was detected in 94 (71.75%) asymptomatic adult cattle from 131 fecal samples examined microscopically. in two cases cryptosporidium oocysts were observed which were distinctly larger (5.5-6.5 microns x 6.6-7.0 microns) than those we had seen in the majority of feces examined (4.0-4.5 microns x 4.0-4.5 microns) and these specimens were considered to be cryptosporidium muris; it is possible that the other oocysts should be considered as cryptosporidium parvum. the sero ...	1993	8493772
nonspecific immunomodulation influences the course and location of cryptosporidium parvum infection in neonatal balb/c mice.	the influence of nonspecific immunomodulation with thymomodulin (a calf thymic extract with immunomodulatory activity) and hydrocortisone on the course and location of cryptosporidium parvum infection in neonatal balb/c mice (infected with 10(6) or 10(5) oocysts on day 7 of life) was studied using scanning electron microscopy of the inner surface of different parts of intestine. daily peroral treatment of suckling mice with 20 mg/kg/day of thymomodulin for 5 days before inoculation resulted in a ...	1993	8494297
curative and preventive anticryptosporidium activities of sinefungin in an immunosuppressed adult rat model.	an immunosuppressed rat model was used to investigate the anti-cryptosporidium parvum activity of sinefungin. in infected animals, oral sinefungin therapy resulted in a dose-related suppression of oocyst shedding, which correlated with oocyst disappearance from ileal sections. when administered prior to or on the day of oocyst challenge, sinefungin successfully prevented infection. these data suggest that sinefungin could be considered as a candidate molecule in the treatment of human cryptospor ...	1993	8494386