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1.
Piglets between 1 and 40 days of age were inoculated with varying numbers and with different isolates of Streptococcus suis type 2 by the intranasal, intravenous and subarachnoid routes. Less than 100 organisms of an isolate cultured from apparently normal pigs caused subclinical infection in 1-day-old piglets after intranasal inoculation. This infection was naturally transmitted between litter mates. Intravenous inoculation of a similar isolate in 7-week-old pigs resulted in a sub-clinical bacteraemia in 3 of 8 piglets. One other piglet developed a bacteraemia 7 days after inoculation and concurrently developed signs of lameness and nervous dysfunction. Ten piglets were inoculated by the subarachnoid route with a porcine isolate and two with an isolate from a person with clinical disease. Only the latter two pigs developed the classical signs of nervous disease associated with infection by S. suis type 2. It is concluded that strains of S. suis type 2, of varying pathogenicity for both pigs and man, are endemic in New Zealand. It is suggested that the occurrence of disease is associated with both exposure to a pathogenic strain and other, as yet undetermined, secondary factors. 相似文献
2.
BACKGROUND: There are obvious advantages to increasing donor retention. However, for reasons of blood safety, certain donors may, in fact, be more desirable to retain than others. “Safe” donors are defined as those who provided a blood donation that was negative on all laboratory screening tests and who subsequently reported no behavioral risks in response to an anonymous survey. This study identifies the most important factors affecting the intention of “safe” donors to provide another donation. STUDY DESIGN AND METHODS: An anonymous survey asking about donation history, sexual history, injecting drug use, and recent donation experience was mailed to 50,162 randomly selected allogeneic donors (including directed donors) who gave blood from April through July or from October through December 1993 at one of the five United States blood centers participating in the Retrovirus Epidemiology Donor Study. Before mailing, questionnaires were coded to designate donors with nonreactive laboratory screening tests at their most recent donation. RESULTS: A total of 34,726 donors (69%) responded, with substantially higher response among repeat donors. According to reported intentions only, the vast majority of “safe” donors indicated a high likelihood of donating again within the next 12 months. Only 3.4 percent reported a low likelihood of donating again. A comparison of those likely to return and those unlikely to return reveals significant differences in demographics and in ratings of the donation experience. A higher proportion of those unlikely to return were first-time donors, minority-group donors, and donors with less education. The highest projected loss among “safe” donors was seen for those who gave a fair to poor assessment of their treatment by blood center staff or of their physical well-being during or after donating. CONCLUSION: These data suggest that efforts to improve donors' perceptions of their donation experience, as well as attention to the physical effects of blood donation, may aid in the retention of both repeat and first-time donors. 相似文献
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4.
Rosenberg ZS; Jahss MH; Noto AM; Shereff MJ; Cheung Y; Frey CC; Norman A 《Radiology》1988,167(2):489-493
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture. 相似文献
5.
C. Craig Blackmore MD MPH Eric K. Hoffer MD Emily Albrecht PA-C Frederick A. Mann MD 《Journal of the American College of Radiology》2004,1(6):410-414
We describe a model of how physician assistants can be used in an academic medical center to expand radiologist productivity, and to enhance the departmental academic and educational missions. At Harborview Medical Center, following a training program and graduated responsibility under supervision, physician assistants provide initial interpretation of radiology studies, consultation to referring physicians, and perform less complicated interventional procedures. Acceptance of physician assistants by the radiologists, radiology residents, and referring physicians has been high. Although the impact of physician assistants on departmental clinical productivity is difficult to measure, our data suggest that radiologists are more efficient when physician assistants are assigned to service, both in terms of numbers of studies interpreted, and timeliness of reporting and billing. As a result of the success of our program, we believe that physician assistants can have an important role in radiology practice. 相似文献
6.
Intestinal schistosomiasis japonica: CT-pathologic correlation 总被引:1,自引:0,他引:1
Lee RC; Chiang JH; Chou YH; Rubesin SE; Wu HP; Jeng WC; Hsu CC; Tiu CM; Chang T 《Radiology》1994,193(2):539
7.
Mice, rats, guinea-pigs and rabbits were inoculated with isolates of Streptococcus suis type 2. An isolate cultured from the tonsils of a healthy pig, produced disease in rabbits after intravenous inoculation but not in mice, rats or guinea-pigs. An isolate of S. suis type 2, that was pathogenic for pigs and had been cultured from a human patient with clinical disease, produced signs of neurological disease in mice, rats and rabbits following intravenous inoculation. There was an apparent dose response in mice with 31% of mice receiving more than 10(6) organisms developing clinical disease, whilst mice receiving less than this did not develop disease. There were no detectable histopathological lesions in the brains or meninges of mice with nervous signs. It is proposed that the disease in mice may mimic that reported in humans and that mice may be a useful indicator species for determining the virulence of isolates cultured from pigs. 相似文献
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10.
Synthesis of DNA by the spleens of germ-free mice during the primary response to sheep red cells 总被引:4,自引:0,他引:4
The mitotic activity of the spleens of non-immunized germ-free (GF) mice was less than in similar specific pathogen-free (SPF) animals. No evidence of germinal center activity was noted in these GF mouse spleens before challenge with sheep erythrocytes (SRC). These centers only began to develop 4 days after immunization and were not fully developed before 8 days. In control SPF mice, the spleens showed very few germinal centers which were small in size, but they showed the same pattern of evolution as in similarly immunized GF mice. The changes in the red pulp, characterized by the development of clusters of nuclei labeled with [3H]thymidine, followed closely the development of plaqueforming cells (PFC). The numbers of direct PFC reached the same peak level in GF and SPF mice on day 4 of the response to SRC, but were not so well sustained in the former animals after this time. Indirect PFC were much lower in the spleens of GF mice than in SPF animals. The pattern and degree of increase of DNA synthesis in the spleen of GF and SPF mice following immunization with SRC differed from and was less than that of mice reared in less clean conditions. Increased DNA synthesis occurred very soon after injection of SRC (6 to 24 h) and the increase was sustained for 4 days without further significant rise and then declined. Autoradiographs of the spleen of immunized GF mice given [3H]thymidine showed that the first increase of labeled nuclei in the white pulp occurred around the central arterioles as early as 6 h after SRC. This was followed by increased labeling in the mantle layer of the white pulp and the characteristic pattern of germinal center labeling developed after 4 days. Increased labeling of nuclei developed in the red pulp as early as in the white pulp, while the subcapsular and trabecular areas showed high labeling indices even in the spleens of non-immunized controls. The ratio of labeling index/mitotic index which is governed by the respective durations of DNA synthesis and mitosis in those cells in division cycle, varied between 10 and 280 in different areas of the spleen. This indicated a vast excess of cells synthesising DNA in relation to the numbers of dividing cells actually present in the spleens of these mice. 相似文献