Clinician information activities in diverse ambulatory care practices.

Ambulatory care is assuming an increasing role in health-care delivery. Yet, most health-care information systems were developed for the acute-care setting. To address the needs of ambulatory care, developers need a comprehensive understanding of the information-related activities of clinicians in heterogeneous outpatient practices. We studied the information activities of clinicians in seven diverse (primary-care, specialty-care, faculty, and independent private practices) ambulatory care sites. The results of our study allow us to characterize clinicians' information-related activities, their perceived information needs, and their satisfaction with computer resources. Developers of health-care information systems can use the results to design applications for clinicians in ambulatory care.

Methods for assessing information needs of clinicians in ambulatory care.

Clinical information systems that provide physicians with relevant information at the time and place where decisions are being made can positively affect the quality and cost of health care. We have developed an assessment methodology to study clinicians' information needs in the context of the work flow and operational constraints of the ambulatory care practice environment. We employed a combination of methods, including observational studies, process flowcharting, semi-structured interviews, and surveys to comprehensively define clinicians' needs. Results from our study point to functional requirements not commonly found in hospital-based systems, such as access to problem lists and medications, computer-based support for health-care team communications, and patient-specific instructions and education.

Development of a model ribosomal RNA hybridization assay for the detection of Sarcocystis and other coccidia.

Two regions of the primary structure of the small subunit rRNA of Sarcocystis muris bradyzoites were compared with nucleotide sequences of S. gigantea, Toxoplasma gondii, Plasmodium berghei and Mus musculus and used to design genus- and species-specific probes for the detection and identification of coccidia. Total cellular RNA of purified S. muris, S. cruzi, T. gondii and Eimeria nieschulzi and coccidia-infected tissues of mouse, ox, sheep and pig, were assayed using twenty-base oligomers labelled with 32P. Hybridization occurred at temperatures ranging from 21 degrees C to 41 degrees C or 51 degrees C. One probe detected only S. muris and another successfully hybridized to several members of coccidia, including S. muris, S. cruzi, T. gondii and E. nieschulzi. One ng of total cellular RNA was sufficient to yield detectable hybrids in slot blot assays. The excellent sensitivity suggests that rRNA-based probes are capable of detecting individual parasites, and can assay low levels of coccidial infections not detectable by other methods. The results of this study show that it is possible to customize the specificity of rRNA-based probes for diagnostic, epidemiological or taxonomic purposes.

Ultrastructural and transmission evidence of Sarcocystis cruzi associated with eosinophilic myositis in cattle.

Skeletal muscle, diaphragm, tongue, esophagus and heart of beef carcasses that were condemned for eosinophilic myositis and those that were unaffected were collected at an abattoir in Colorado and studied to determine the involvement of Sarcocystis spp. All affected carcasses contained similar granulomatous lesions with adjacent infiltrations of leukocytes. Intact or fragments of sarcocysts were found within 32 of 363 granulomas, and whole sarcocysts were present in nearby unaffected muscle cells. Light and electron microscopic examinations revealed that sarcocysts, affected or unaffected by cellular response in condemned carcasses, as well as those found in unaffected carcasses, were consistent with those of S. cruzi. Transmission experiments confirmed that S. cruzi were present in all carcasses, and that dogs, but not cats, were the definitive hosts. The results of pepsin-HCl digestion assays showed that unaffected carcasses that were approved for human consumption generally contained more infective parasites than carcasses that were condemned for eosinophilic myositis. This study provides evidence to support the suggestion that dogs, rather than cats, and unaffected rather than eosinophilic myositis-affected carcasses, have greater potential for contributing to the perpetuation of eosinophilic myositis in the cattle industry.

Coccidia of the llama, Lama glama, in Colorado and Wyoming.

Fecal samples were collected from 144 llamas, Lama glama, on four premises in northern Colorado and southern Wyoming. Feces were examined for the presence of coccidial oocysts; Eimeria alpacae was found in 55.6%, Eimeria lamae in 67.3% and Eimeria macusaniensis in 1.4% of the samples. An adult female llama was found to be infected with Eimeria macusaniensis at necropsy. This is the first report of these species of coccidia in the llama.

Ribosomal RNA sequences of Sarcocystis muris, Theileria annulata and Crypthecodinium cohnii reveal evolutionary relationships among apicomplexans, dinoflagellates, and ciliates.

Sarcocystis muris is a coccidium with a two-host life cycle involving the domestic cat and the mouse, Mus musculus. S. muris and Theileria annulata belong to the phylum Apicomplexa, but the latter organism is a tick-borne protozoon in the subclass Piroplasmea and causes tropical theileriosis in cattle. The small-subunit ribosomal RNA (16S-like rRNA) coding regions of these organisms as well as that of the free living dinoflagellate Crypthecodinium cohnii were amplified using polymerase chain reaction techniques and compared to 16S-like rRNA sequences from other eukaryotes. The 16S-like rRNA genes of S. muris and T. annulata are more similar to each other than either is to Plasmodium falciparum, the cause of malignant tertian malaria of humans or Plasmodium berghei, the agent of the commonly studied malaria of rodents. Evolutionary trees inferred from the rRNA sequence similarities support a close phylogenetic relationship between the Apicomplexa and Dinoflagellata as represented by Prorocentrum micans and C. cohnii. Apparently members of these related phyla arose from an ancestral stock that gave rise to the ciliated protozoa.

Merogony and gametogony of Eimeria mccordocki (Protozoa-Eimeriidae) in the mule deer, Odocoileus h. hemionus.

Eimeria mccordocki and E. madisonensis oocysts were isolated from feces of 21 of 40 captive mule deer in Fort Collins, Colorado. The two species were separated from each other by infecting one mule deer fawn, and the life cycle of E. mccordocki was studied for the first time. Four to six-weeks-old mule deer fawns were inoculated orally with E. mccordocki and killed 9, 13 and 15 days after infection. Asexual and sexual stages of life cycle developed in the ileum of mule deer, only in the surface epithelial cells of the villi. The asexual stages consisted of two generations of meronts.

Immunity to Eimeria separata (Apicomplexa: Eimeriina): expose-and-challenge studies in rats.

Oocyst production of Eimeria separata of the rat was determined in initial and challenge infections. The total number of oocysts produced was no higher at 100 oocysts than at 1,000, 10,000, or 100,000 in initial infections. In 2 experiments, the reproductive index with 100 oocysts was 17,000 and 34,000, respectively. On challenge with 10,000 oocysts, there was 91% protection at 100 oocysts. There was slightly lower protection at 10,000 and 100,000 oocysts, 72% and 81%, respectively, and t-values suggest lower protection at these higher inocula.

Eosinophilic myositis and muscular sarcocystosis in the carcasses of slaughtered cattle and lambs.

Fifty-three bovine and 7 ovine carcasses condemned for having eosinophilic myositis were evaluated. Four (7.3%) of the bovine carcasses had a few, large local lesions in skeletal muscles (category A), and 49 (92.7%) of the bovine carcasses and 7 (100%) of the ovine carcasses had multiple, small, disseminated lesions in tongue, esophagus, heart, diaphragm, or skeletal muscles (category B). Tissue from carcasses of category B were evaluated for bacteria, viruses, selenium, and pathologic changes. Pathogenic bacteria and viruses were not isolated and selenium concentrations were normal. In category B, all carcasses had granulomas; of the 49 bovine carcasses and 7 ovine carcasses, 38 (77.6%) and 7 (100%), respectively, had one or more granulomas with opened dead sarcocysts. The data indicated that opened sarcocysts killed the host myocyte and adjacent myocytes and stroma, thereby initiating granuloma formation.

Nucleolar hypertrophy as an indicator of transcription in cells infected with second generation meronts of Eimeria tenella.

Changes in nuclei and nucleoli of cells of chicken cecum infected with Eimeria tenella were studied in living cells by interference microscopy and in fixed and stained tissues using light level microscopy. As soon as merozoites began to transform into second generation meronts, there was an increase in the size of both the nucleus and the nucleolus of the host cell. The dry weight of the nucleus increased somewhat, but there was a greater increase and a correlation of the dry mass of the nucleolus with the size of the parasite as measured by interference microscopy. In fixed and stained tissues, there was a correlation between the area of the nucleolus and the area of the parasite. Removal of nucleic acids with DNase and/or RNase showed high concentrations of both in the nucleoli and a residue of protein. The increased nucleolar size indicates a high level of transcription in infected cells and allows the conclusion that the parasite somehow induces transcription to occur. Since transcription is a highly specific process, the high degree of host and site specificity shown by nearly all coccidia is consistent with a hypothesis that the coccidia share a portion of the host genome.

Arrested development in Eimeria nieschulzi (Apicomplexa: Eimeriina): results of single infections.

Arrested development of Eimeria nieschulzi in the rat was investigated by feeding tissues of infected rats to coccidia-free rats. Intestinal tissue of 33 infected rats was fed on days 9, 10, 11, 14, 17, 21, and 28 PI to 43 uninfected recipients. Eight recipients, which represent 24.2% of the donors, later showed infection. Infections were retained for as long as 21 days after the initial infection. A prepatent period of 6 to 7 days in the recipients allowed the inference that the retained stage was the sporozoite. No infections were observed in 14 recipients fed spleen, lymph nodes, liver, or lung of infected animals.

Genetic dependent transmission of Eimeria separata from Rattus to three strains of Mus musculus, an abnormal host.

We examined susceptibility of several strains of mice to Eimeria separata. Mice of the following coat-color genotypes were inoculated with 2 X 10(4) sporulated oocysts of E. separata isolated from Rattus norvegicus: random-bred (aabbCC and A-bbCC), Balb/C (AAbbcc), Balb/Gw (AABBcc), Z/Gw (aaBBcc), and Swiss NLW (cc). Allele designations are A = agouti, a = nonagouti, B = black, b = brown, C, c = albino. Eimeria separata completed its life cycle with oocyst production in all male and female random-bred (aabbCC), Balb/Gw and G/Gw mice. The reproductive index of E. separata in Balb/Gw mice was significantly lower (P less than or equal to 0.05) than that of the other mouse strains. Among the random-bred mice, E. separata had a significantly lower (P less than or equal to 0.05) mean reproductive index in male than in female hosts. Patent period and oocyst length/width indices remained constant irrespective of host genus. This is the first documentation that genetic factors play a role in susceptibility of mice to the rat coccidium, E. separata.

Some problems of host and parasite interactions in the coccidia.

The current status of some concepts of host and parasite interactions in the coccidia are discussed and evaluated. It is suggested that winter coccidiosis of cattle caused by Eimeria zuernii results from activation of arrested endogenous stages in the tissues of the host. A second aspect of clinical coccidiosis is that infections are seldom monospecific, but little work has been done on infections in animals with multiple species of coccidia. Information in the literature indicates that there are interactions between species of Eimeria in concurrent infections, and it is hoped that investigators will undertake studies to define more clearly what interactions there may be. Finally, the finding that there is a genetic basis for successful transmission of Eimeria separata from rats to mice provides a tool for studying the basis of host-specificity in the coccidia.