Publications

the species of cryptosporidium (apicomplexa: cryptosporidiidae) infecting mammals.	oocysts of cryptosporidium muris (apicomplexa: cryptosporidiidae) were obtained from the feces of naturally infected calves. oocysts were fully sporulated in fresh feces, measured 7.4 x 5.6 (6.6 - 7.9 x 5.3 - 6.5) micron, and possessed a longitudinal suture along one pole of the oocyst wall. morphologic and biologic evidence obtained from this study demonstrated that c. muris is a species distinct from cryptosporidium parvum, which has smaller oocysts.	1985	4057006
ultrastructure of cryptosporidium parvum oocysts and excysting sporozoites as revealed by high resolution scanning electron microscopy.	cryptosporidium parvum oocysts isolated from calf feces were examined by scanning electron microscopy during excystation. intact c. parvum oocysts were spheroid to ellipsoid, approximately equal to 3.5 x 4.0 micron, with length : width ratio = 1.17. the oocyst wall had a single suture at one pole, which spanned 1/3 to 1/2 the circumference of the oocyst. during excystation the suture dissolved, resulting in a slit-like opening, which the sporozoites used to exit the oocyst. sporozoites were 3.8 ...	1985	4067883
infection dynamics of cryptosporidium parvum (apicomplexa: cryptosporiidae) in neonatal mice (mus musculus).		1986	3806334
experimental cryptosporidium parvum infections in chickens.		1987	3572661
abomasal cryptosporidiosis in cattle.	a 6-week-old calf and nine feedlot steers shed oocysts similar to cryptosporidium muris-like oocysts. there were massive populations of this cryptosporidium in the peptic glands of most of these animals. the oocysts were larger and more oval than the frequently reported type which is generated in the intestines of many animal species and thought to be similar to cryptosporidium parvum. the pattern of shedding of this newly discovered cryptosporidium in the steers was continuous over a period of ...	1987	3603962
infectivity and neutralization of cryptosporidium parvum sporozoites.	cryptosporidiosis, a diarrheal disease of calves and humans caused by the coccidian parasite cryptosporidium parvum, is terminated in hosts with normal immune systems. to assess the mechanisms of immunity in cryptosporidiosis, it is necessary to isolate and quantitate sporozoites, the infective stage of cryptosporidium spp. here we report the (i) separation of infective c. parvum oocysts from calf feces by ether extraction, sieving, and hypochlorite treatment; (ii) separation of viable c. parvum ...	1987	3623693
cryptosporidiosis associated with bacterial enteritis in a goat kid.	a 7-day-old male nubian-alpine crossbred goat was examined because of listlessness, anorexia, and diarrhea. the presumptive diagnosis was severe enteritis. large numbers of clostridium perfringens and a non-pathogenic heavily encapsulated escherichia coli were isolated from the feces. cryptosporidium parvum was identified on the qualitative fecal examination. the kid improved after treatment with fluids and antibiotics.	1987	3301766
characterization of the cryptosporidium antigens from sporulated oocysts of cryptosporidium parvum.	the antigenic constituents of sporulated cryptosporidium parvum oocyst antigens were characterized with antisera from mice immunized against c. parvum. sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver staining defined the major proteins. six of seven lectins used recognized as many as 15 bands. the lectins concanavalin a, dolichos biflorus, and wheat germ agglutinin showed strong activity against the same eight bands with molecular weights ranging from 72,000 to great ...	1987	3308705
studies of in vitro excystation of cryptosporidium parvum from calves.	studies of in vitro excystation of cryptosporidium parvum from calves showed that sporozoite yields were optimum when oocysts were treated with sodium hypochlorite, then incubated at 37 degrees c for 60 min in the presence of taurocholic acid solutions at ph about 7.0. trypsin was not required for excystation and high concentrations were inhibitory. studies using protease inhibitors and direct assays for proteolysis failed to implicate proteolytic enzymes as effectors of excystation. the results ...	1987	3123647
location and pathogenicity of cryptosporidium parvum in experimentally infected mice.		1988	3188727
experimental cryptosporidiosis in fetal lambs.	fetal lambs were infected in utero with purified sporulated oocysts of cryptosporidium parvum in order to study pathogenesis and host cellular response to the enteropathogen. ileal loops (il) of fetuses, 124-130 days of gestation, were inoculated with 1-4 x 10(6) oocysts usually via cannulae in the abdominal wall of the ewe. oocysts, both free and phagocytosed, were observed in the il content as early as day 1 post-inoculation (pi). the percentage of oocysts phagocytosed by the host's polymorpho ...	1988	3193331
field inversion gel electrophoretic separation of cryptosporidium spp. chromosome-sized dna.	chromosomal dna from 5 isolates of cryptosporidium parvum and 1 of c. baileyi were compared by field-inversion gel electrophoresis (fige). fige analyses of parasite dna prepared from purified sporozoites versus intact oocysts showed no observable differences. chromosomal dna migration patterns of the 5 c. parvum isolates were indistinguishable, whereas similar but distinct differences were evident between c. baileyi and the isolates of c. parvum. oocyst-reactive monoclonal antibodies differentia ...	1988	3288738
lacteal immunity to enteric cryptosporidiosis in mice: immune dams do not protect their suckling pups.	the susceptibilities of passively immunized principal and nonimmunized control suckling mice to orogastric challenge with cryptosporidium parvum oocysts were compared. principals were suckled by dams that had recovered from c. parvum infection. controls were suckled by dams reared free of c. parvum infection. principals and controls were equally susceptible to challenge. principals were susceptible even when their dams were hyperimmunized by oral and parenteral booster inoculations with c. parvu ...	1988	3343052
experimental cryptosporidium parvum infections in opossums (didelphis virginiana).	five nursing opossums (didelphis virginiana) were each inoculated with 5 x 10(6) cryptosporidium parvum oocysts of calf origin. following inoculation, endogenous stages of c. parvum were observed in the ileum, cecum, and colon of these opossums. two of three noninoculated pouch mates acquired infections during the study based on examinations of feces and tissue sections of all eight opossums. mild diarrhea was observed in four of seven opossums harboring c. parvum, although none died as a result ...	1988	3352085
susceptibility of germfree or antibiotic-treated adult mice to cryptosporidium parvum.	adult mice are more resistant than neonatal mice to intestinal colonization with the protozoan parasite cryptosporidium parvum. development of a mature intestinal flora may play a role in this resistance. we compared susceptibilities to colonization with c. parvum in adult conventional mice, adult germfree mice, and adult conventional mice treated with oral antibiotics to deplete the intestinal flora. germfree mice of both cd1 and balb/c strains were colonized at day 7 following inoculation with ...	1988	3397183
efficacy of a pentaiodide resin disinfectant on cryptosporidium parvum (apicomplexa: cryptosporidiidae) oocysts in vitro.	the resin-i5 column developed at kansas state university was tested for efficacy against oocysts of cryptosporidium parvum (apicomplexa: cryptosporidiidae). cesium chloride gradient-purified oocysts were passed through 1.0-cm-diameter columns with lengths of 2.5, 5.0, and 10.0 cm at 23 c. following column passage, oocyst viability was determined both in vitro by excystation and in vivo by the ability to establish infections in suckling mice. oocysts were found to be retained by the pentaiodide r ...	1988	3397833
indirect immunofluorescent detection of oocysts of cryptosporidium parvum in the feces of naturally infected raccoons (procyon lotor).	fecal samples from 100 wild raccoons were examined for the presence of oocysts of cryptosporidium parvum using a commercially available indirect immunofluorescent detection procedure. thirteen (13%) of the samples were positive for oocysts. all positive samples were from juvenile raccoons. over 61% of the infected samples contained moderate to large numbers of oocysts. raccoons may serve as potential reservoirs for transmission of c. parvum.	1988	3057164
neutralization-sensitive epitopes are exposed on the surface of infectious cryptosporidium parvum sporozoites.	cryptosporidiosis is a diarrheal disease of humans, calves, and other mammals caused by the coccidian parasite cryptosporidium parvum. immune bovine serum and two surface-reactive antisporozoite mab with neutralizing activity were used to identify sporozoite surface ag by radioimmunoprecipitation/sds-page and immunoblotting. when isolated sporozoites were incubated with mab 18.44, 12 to 25 times the id50 for mice was completely neutralized. this mab binds diffusely to the sporozoite surface and ...	1989	2473130
the pathogenicity of cryptosporidium parvum tyzzer, 1912 and c. baileyi current, upton et haynes, 1986 for chickens.	clinical symptoms and pathological-morphological changes in the respiratory tract of chickens inoculated with cryptosporidium parvum were described for the first time and compared with those induced by cryptosporidium baileyi. intratracheal inoculation with these two species caused symptoms of a respiratory tract disease in all chicken, but a disease of the digestive tract or death did not occur in any case. pathological and morphological changes were observed only in the respiratory system and ...	1989	2583611
an unusual localization of developmental stages of cryptosporidium parvum tyzzer, 1912 in the cells of small intestine of a gnotobiotic piglet.	in a gnotobiotic piglet infected with 50.10(6) oocysts of cryptosporidium parvum, developmental stages of the parasite were found in the duodenum, anterior jejunum and middle jejunum on the first day post infection (1 dpi). during the studies of the ultrastructure, trophozoites and meronts of c. parvum were encountered in the microvillous zone of enterocytes, and the outer membrane of parasites was a continuation of the membrane of microvilli. unusual was the attachment of c. parvum trophozoite ...	1989	2583612
effects of colostral antibody on susceptibility of calves to cryptosporidium parvum infection.	effects of colostral antibody on susceptibility of calves to cryptosporidium parvum infection were examined. six calves were fed pooled colostrum that contained c parvum antibody, 6 times daily (at 4-hour intervals) for 7 days and then milk replacer for 7 days. colostrum was obtained from healthy cows or cows inoculated parenterally with c parvum oocysts before parturition. antibody content was determined in serum and colostrum whey, using an elisa for anticryptosporidia immunoglobulin. six calv ...	1989	2610438
gastrointestinal helminths and protozoa from two raccoon populations in kansas.	a survey in kansas compared the prevalence of gastrointestinal helminths and protozoa in 2 raccoon (procyon lotor) populations; a population in a typical rural setting and a relatively undisturbed population on a military reservation. gastrointestinal tracts of 128 raccoons were examined. freeze storage of alimentary tracts prevented collection of data on trematode prevalence. helminth infections other than trematodes included 1 acanthocephalan, 2 cestodes, and 3 nematodes. helminths were found ...	1989	2614594
evaluation of immunofluorescence techniques for detection of cryptosporidium oocysts and giardia cysts from environmental samples.	cryptosporidium and giardia species are enteric protozoa which cause waterborne disease. the detection of these organisms in water relies on the detection of the oocyst and cyst forms or stages. monoclonal and polyclonal antibodies were compared for their abilities to react with giardia cysts and cryptosporidium oocysts after storage in water, 3.7% formaldehyde, and 2.5% potassium dichromate, upon exposure to bleach, and in environmental samples. three monoclonal antibodies to cryptosporidium pa ...	1989	2694962
efficacy of hyperimmune bovine colostrum for prophylaxis of cryptosporidiosis in neonatal calves.	twelve neonatal calves were experimentally infected with oocysts of cryptosporidium parvum. six calves in group a fed hyperimmune colostrum at birth had significantly less diarrhea and shed oocysts for less time than did 6 calves in group b fed colostrum from cows that were not hyperimmune. calves in group a had diarrhea for 0-4 days (means = 2.3 days), whereas calves in group b had diarrhea for 4-6 days (means = 5.0 days). calves in group a shed oocysts for 4-9 days (means = 6.2 days), whereas ...	1989	2723925
effects of immune colostrum and orally administered antisporozoite monoclonal antibodies on the outcome of cryptosporidium parvum infections in neonatal mice.	a neonatal balb/c mouse model of cryptosporidiosis was used to examine the potential passive transfer of immunity via immune colostrum and oral treatment with anticryptosporidial monoclonal antibodies. neonates suckled by dams that recovered from cryptosporidium parvum infections were equally susceptible to infection as their control counterparts suckled by naive dams. parasite loads among the control and immune colostrum-fed mice were indistinguishable. neonates receiving orally administered an ...	1989	2744847
effect of disinfection of drinking water with ozone or chlorine dioxide on survival of cryptosporidium parvum oocysts.	demineralized water was seeded with controlled numbers of oocysts of cryptosporidium parvum purified from fresh calf feces and subjected to different treatments with ozone or chlorine dioxide. the disinfectants were neutralized by sodium thiosulfate, and neonatal mice were inoculated intragastrically and sacrificed 7 days later for enumeration of oocyst production. preliminary trials indicated that a minimum infection level of 1,000 oocysts (0.1-ml inoculum) per mouse was necessary to induce 100 ...	1989	2764564
hyperimmune bovine colostrum neutralizes cryptosporidium sporozoites and protects mice against oocyst challenge.	activity of colostral whey, produced by a cow immunized with oocysts of cryptosporidium parvum and found to provide prophylaxis against cryptosporidiosis in calves, was tested in 2 experiments. in one experiment balb/c mice were given the immune whey (hw), whey from a nonimmunized cow (cw), or a balanced salt solution (hbss) before, during, and after oral inoculation with oocysts of c. parvum. significantly fewer (p less than 0.05) c. parvum were found in mice that received hw (undiluted, 1:20 o ...	1989	2783966
cryptosporidium parvum merozoites share neutralization-sensitive epitopes with sporozoites.	sporozoites and merozoites are stages in the life cycle of cryptosporidium parvum that can cyclically infect intestinal cells, causing persistent infection and severe diarrhea in immunodeficient patients. infection by sporozoites can be neutralized by surface-reactive mab. we show that merozoite infectivity can also be neutralized by surface-reactive mab. to do this, viable c. parvum merozoites were isolated by differential and isopycnic. centrifugation, and distinguished from sporozoites by tra ...	1990	2193057
treatment with bovine hyperimmune colostrum of cryptosporidial diarrhea in aids patients.	cryptosporidium parvum may cause severe, debilitating diarrhea in patients with aids. recent anecdotal reports have suggested that hyperimmune bovine colostrum may be effective. we conducted a double-blind, controlled pilot study of hyperimmune bovine colostrum for diarrhea due to cryptosporidiosis in five aids patients. the patients were randomized to receive either hyperimmune or control colostrum by continuous nasogastric infusion for 10 days. all stools were collected, graded, and weighed, a ...	1990	2201320
in vitro cultivation of cryptosporidium parvum and screening for anticryptosporidial drugs.	sporozoites of cryptosporidium parvum which were excysted in vitro from oocysts isolated from calves or patients with acquired immune deficiency syndrome underwent development in monolayers of the mouse fibroblast cell line l929. asexual multiplication occurred, with the maximum numbers of parasites usually being observed between 24 and 48 h after infection. gametocytes were also found, but their numbers were relatively small compared with those of the asexual stages. a study was made of the eff ...	1990	2221857
some infectious causes of diarrhea in young farm animals.	escherichia coli, rotaviruses, and cryptosporidium parvum are discussed in this review as they relate to enteric disease in calves, lambs, and pigs. these microorganisms are frequently incriminated as causative agents in diarrheas among neonatal food animals, and in some cases different strains or serotypes of the same organism cause diarrhea in humans. e. coli causes diarrhea by mechanisms that include production of heat-labile or heat-stable enterotoxins and synthesis of potent cytotoxins, and ...	1990	2224836
histopathological method for diagnosis of cryptosporidiosis using monoclonal antibodies.	a monoclonal antibody directed against the oocyst wall of cryptosporidium parvum was produced which strongly reacted with 25 strains of the parasite. this antibody was assessed for use in a diagnostic immunoperoxidase assay performed on tissue sections. it permitted an intense and specific staining of the parasite in five biopsies positive for cryptosporidium parvum fixed with routine techniques. the procedure described may be useful in screening mucosal biopsies from immunosuppressed patients.	1990	2226494
case-control study of cryptosporidium parvum infection in peruvian children hospitalized for diarrhea: possible association with malnutrition and nosocomial infection.	a retrospective, hospital-based case-control study was used to investigate whether there were any clinical characteristics that could distinguish cryptosporidium parvum-infected children with diarrhea from other non-c. parvum-infected children with diarrhea. ten percent (24 of 248) of children admitted to a rehydration ward at cayetano heredia university hospital, lima, peru, were infected with c. parvum. the 24 patients infected with c. parvum (cases) were matched to an equal number of noninfec ...	1990	2235186
[an electron microscopic study of cryptosporidium. ii. the stages of gametogenesis and sporogony in cryptosporidium parvum].	the ultrastructure of stages of gametogony and sporogony of c. parvum from the intestine of experimentally infected suckling rats was studied by transmission electron microscope. unlike merogony, in which the whole cytoplasm of the mother meront is used up for the merozoite formation, during microgametogony the large residual mass of gamonts remains in contact with the feeder organelle even after microgamete outbudding. unlike other coccidia, during the microgametogenesis in c. parvum, the nucle ...	1990	2238114
coccidiosis and cryptosporidiosis in sheep and goats.	the protozoan diseases, coccidiosis and cryptosporidiosis, are important enteric diseases of sheep and goats, resulting in diarrhea, inefficient weight gains, and occasionally death. coccidiosis is a widespread, serious economic disease affecting animals who are preweaned, recently weaned, or in unsanitary, stressful, or crowded conditions, as well as after entering feedlots. the eimeria species in sheep and goats are relatively host specific. control is accomplished through sanitation and by in ...	1990	2245367
[electron microscopic research on cryptosporidium. i. the asexual stages in the development of cryptosporidium parvum].	ultrastructural studies were conducted on asexual developmental stages of c. parvum in the ileal fragment of the intestine of 10-11 day old rats experimentally infected with oocysts isolated from calf feces. a young trophozoite is covered with the typical trimembranous apicomplexan pellicle. as the parasite grows, the inner complex of its apical pellicle, facing the host enterocyte, is seen to reduce up to a unit membrane to make a complex multimembranous "feeding organelle" which is in contact ...	1990	2275015
detection of cryptosporidium parvum oocysts in bovine feces by monoclonal antibody capture enzyme-linked immunosorbent assay.	a monoclonal antibody enzyme-linked immunosorbent assay (elisa) was developed to detect cryptosporidium parvum oocysts in bovine feces. fecal oocysts were concentrated by centrifugation through formalin-ethyl acetate solution and captured with monoclonal antibody 18.280.2 reactive with c. parvum oocysts. captured oocysts were detected with goat anti-oocyst serum, following the addition of a peroxidase conjugate of rabbit anti-goat immunoglobulin and o-phenylenediamine substrate. the assay was sp ...	1990	2280009
kinetics of cryptosporidium parvum sporozoite neutralization by monoclonal antibodies, immune bovine serum, and immune bovine colostrum.	monoclonal antibodies, immune bovine serum, and immune bovine colostral whey neutralized infectivity of cryptosporidium parvum sporozoites for mice in a time-dependent manner. immune colostral whey neutralized sporozoites more rapidly and completely than immune serum, monoclonal antibody (mab) 18.44, or a combination of mab 18.44 and mab 17.41. mice were partially protected against oral challenge with c. parvum oocytes when treated with immune colostral whey, mab 17.41, or a combination of mab 1 ...	1990	2294054
effects of ozone, chlorine dioxide, chlorine, and monochloramine on cryptosporidium parvum oocyst viability.	purified cryptosporidium parvum oocysts were exposed to ozone, chlorine dioxide, chlorine, and monochloramine. excystation and mouse infectivity were comparatively evaluated to assess oocyst viability. ozone and chlorine dioxide more effectively inactivated oocysts than chlorine and monochloramine did. greater than 90% inactivation as measured by infectivity was achieved by treating oocysts with 1 ppm of ozone (1 mg/liter) for 5 min. exposure to 1.3 ppm of chlorine dioxide yielded 90% inactivati ...	1990	2339894
identification of isolate-specific sporozoite proteins of cryptosporidium parvum by two-dimensional gel electrophoresis.	five isolates of cryptosporidium parvum collected from human, horse, and calf sources were compared for differences in sporozoite protein patterns by using two-dimensional gel electrophoresis. silver-stained two-dimensional gels contained over 300 protein spots from detergent-solubilized sporozoites. a distinguishing 106-kilodalton peptide that shifted in isoelectric point was detected in four of the five isolates. computerized two-dimensional gel analysis was performed to obtain objective quant ...	1990	2365452
resistance of calves to cryptosporidium parvum: effects of age and previous exposure.	cryptosporidium parvum is a coccidian parasite that causes diarrheal disease in many vertebrate species, including young (less than or equal to 1 month old) calves. older calves and adult cattle are resistant to infection. in this study, newborn calves were raised in isolation from c. parvum for 1 week to 3 months before experimental challenge with the parasite. calves orally challenged with c. parvum at 1 week of age shed oocysts in their feces and had diarrhea after challenge exposure. when th ...	1990	2365460
immunotherapeutic efficacy of bovine colostral immunoglobulins from a hyperimmunized cow against cryptosporidiosis in neonatal mice.	infection with cryptosporidium parvum, a ubiquitous protozoan parasite of virtually all mammals, can cause mild to severe diarrhea in immunocompetent hosts and life-threatening diarrhea in immunocompromised hosts. passive immunotherapy of experimentally infected animals and naturally infected humans with hyperimmune bovine colostrum has been reported to be efficacious, whereas chemotherapy has not. in this study, the efficacy of specific immunoglobulin isotypes purified from bovine colostrum fro ...	1990	2387630
cryptosporidium parvum (apicomplexa: cryptosporidiidae) oocyst and sporozoite antigens recognized by bovine colostral antibodies.	colostral whey from seven hyperimmunized and two control cows (hyperimmune bovine colostrum) was examined by western immunoblotting for the presence of antibody against oocysts and sporozoites of cryptosporidium parvum, using rabbit anti-bovine immunoglobulin a (iga), igg1, igg2, and igm antibodies, followed by a horseradish peroxidase goat anti-rabbit polyvalent antibody. although considerable variation was found in binding activity between cows on different immunization protocols, iga and igg1 ...	1990	2387631
a controlled trial of bovine dialyzable leukocyte extract for cryptosporidiosis in patients with aids.	cryptosporidial infection causes severe diarrheal disease in patients with aids. fourteen patients with aids and symptomatic cryptosporidiosis were treated with a specific bovine dialyzable leukocyte extract (immune dle) prepared from lymph node lymphocytes of calves immunized with cryptosporidia or a nonspecific (nonimmune) dle prepared from nonimmunized calves. six of 7 patients given immune dle gained weight and had a decrease in bowel movement frequency, with eradication of oocysts from stoo ...	1990	2404072
analysis of the kinetics, isotype and specificity of serum and coproantibody in lambs infected with cryptosporidium parvum.	enteric cryptosporidiosis was studied in colostrum-deprived lambs each infected at five days old with 10(6) oocysts. the prepatent period was three to five days and faecal oocyst concentration fell below detectable levels by day 16 after infection. specific iga, the only isotype detected by immunofluorescent assay in faecal extracts from infected lambs, was first evident on day 10 and titres continued to rise until day 16 of infection in association with declining oocyst output. specific igm and ...	1990	2405460
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
immunogold labeling of stages of cryptosporidium parvum recognized by immunoglobulins in hyperimmune bovine colostrum.	ultrathin sections of mouse ileum infected with cryptosporidium parvum were stained by immunogold techniques. sections first were stained with polyvalent antibodies in whey from hyperimmune bovine colostrum (hbc), then stained by secondary antibodies in rabbit antibovine iga, igm, igg1, and igg2, and lastly labeled by goat anti-rabbit gold conjugate. examination of the immunostained specimens by electron microscopy revealed that each bovine immunoglobulin isotype in the whey recognized antigens ...	1991	2040961