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31.
This study demonstrates a strict temporal requirement for a virulence determinant of the Lyme disease spirochete Borrelia burgdorferi during a unique point in its natural infection cycle, which alternates between ticks and small mammals. OspC is a major surface protein produced by B. burgdorferi when infected ticks feed but whose synthesis decreases after transmission to a mammalian host. We have previously shown that spirochetes lacking OspC are competent to replicate in and migrate to the salivary glands of the tick vector but do not infect mice. Here we assessed the timing of the requirement for OspC by using an ospC mutant complemented with an unstable copy of the ospC gene and show that B. burgdorferi's requirement for OspC is specific to the mammal and limited to a critical early stage of mammalian infection. By using this unique system, we found that most bacterial reisolates from mice persistently infected with the initially complemented ospC mutant strain no longer carried the wild-type copy of ospC. Such spirochetes were acquired by feeding ticks and migrated to the tick salivary glands during subsequent feeding. Despite normal behavior in ticks, these ospC mutant spirochetes did not infect naive mice. ospC mutant spirochetes from persistently infected mice also failed to infect naive mice by tissue transplantation. We conclude that OspC is indispensable for establishing infection by B. burgdorferi in mammals but is not required at any other point of the mouse-tick infection cycle.  相似文献   
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Postoperative combined modality therapy with radiotherapy and 5-fluorouracil (5FU) chemotherapy is an effective adjuvant approach that reduces locoregional and distant metastatic disease in patients with high-risk rectal carcinoma. However, this approach results in a treatment regimen of at least 6 months’duration. The present prospective study investigates the integration of radiotherapy and 5FU chemotherapy in a protocol designed to minimize toxicity and reduce the overall treatment time. A total of 40 patients with TNM stage II or III disease received postoperative radiotherapy at four fractions per week with weekly 5FU bolus injections delivered on the fifth non-radiotherapy day. Patients also received systemic chemotherapy with leucovorin both before and after pelvic irradiation, with the total treatment duration extending for only 18 weeks. Patients were able to complete radiotherapy in 90% of cases, while the delivery of full-dose chemotherapy was achievable in the vast majority. The incidence of haematologic and gastrointestinal toxicities requiring the cessation of treatment was acceptable. With a median follow-up of 20.9 months among surviving patients, the estimated progression-free and overall survival at 2 years were 71 % and 79%, respectively.  相似文献   
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Operatively excised purely regurgitant mitral valves in 108 patients aged 21 to 73 years (mean 55) (63% men) undergoing isolated mitral valve replacement were examined for calcific deposits. Of the 108 patients, 19 (18%) had leaflet or chordal calcific deposits or both, but in each the deposits were small and did not appear to alter mitral function. Of the 19 patients with mitral calcium, 6 had had active infective endocarditis and the calcium likely represented healed vegetations; In 6 other patients, the leaflet calcium had extended from the mitral anulus in the setting of mitral valve prolapse. The average total serum cholesterol levels were higher in the patients with compared with those without mitral calcium. Thus, calcium deposits are relatively infrequent in adults with clinically isolated pure mitral regurgitation, and when they occur, the deposits are small and in themselves do not appear to contribute to mitral dysfunction.  相似文献   
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Little is known of the effects of an interocclusal appliance on the activity of craniocervical muscles in patients with temporomandibular disorder. The bilateral electromyographic activity of the frontalis muscle and sternocleidomastoid muscle were assessed in 10 patients with temporomandibular disorders and eight gender, age and dentally matched asymptomatic control subjects during rest and different clenching tasks with or without an interocclusal appliance. Clenching significantly increased both frontalis and sternocleidomastoid activity from rest. Clenching with an interocclusal appliance, as compared with clenching alone, also significantly reduced frontalis activity in both groups, but not for sternocleidomastoid. Increased electromyographic activity of these muscles may represent co-activation of the craniocervical musculature during clenching.  相似文献   
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BACKGROUND AND OBJECTIVES: Chewing twigs of the mango or neem tree is a common way of cleaning the teeth in the rural and semi-urban population. These twigs are also believed to possess medicinal properties. The present study was conducted to evaluate the antimicrobial effects of these chewing sticks on the microorganisms Streptococcus mutans , Streptococcus salivarius , Streptococcus mitis , and Streptococcus sanguis which are involved in the development of dental caries. An additional objective was to identify an inexpensive, simple, and effective method of preventing and controlling dental caries. MATERIALS AND METHODS: The sticks were sun dried, ground into a coarse powder, and weighed into 5 gm, 10 gm, and 50 gm amounts. These were added to 100 ml of deionized distilled water. After soaking for 48 h at 4 degrees C, the water was filtered. The filtrate was inoculated onto blood agar plates containing individual species of microorganisms and incubated at 37 degrees C for 48 h. Results: Mango extract, at 50% concentration, showed maximum zone of inhibition on Streptococcus mitis . Neem extract produced the maximum zone of inhibition on Streptococcus mutans at 50% concentration. Even at 5% concentration neem extract showed some inhibition of growth for all the four species of organisms. INTERPRETATION AND CONCLUSION: A combination of neem and mango chewing sticks may provide the maximum benefit. We recommend the use of both the chewing sticks.  相似文献   
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It has been argued that the grieving process after suicide bereavement has unique properties (e.g., J. R. Jordan, 2001 Jordan , J. R. (2001). Is suicide bereavement different: A reassessment of the literature. Suicide and Life-Threatening Behavior , 31, 91103.[Crossref], [PubMed], [Web of Science ®] [Google Scholar]). A qualitative study was conducted to explore one aspect of the grieving process—continuing bonds—after suicide bereavement in childhood. Data were collected through semi-structured interviews with 10 suicide-bereaved children and analyzed using Interpretative Phenomenological Analysis (Smith & Osborn, 2003 Smith , J. A. , & Osborn , M. ( 2003 ). Interpretative phenomenological analysis . In. J. A. Smith (Eds.), Qualitative Psychology (pp. 5180 ). London , UK : Sage . [Google Scholar]). Three themes are discussed: thinking about the deceased, coping strategies, and ongoing connections to the deceased. The findings highlight potentially unique qualities of continuing bonds after childhood suicide bereavement and factors that might influence their adaptiveness. Theoretical and clinical implications are outlined.  相似文献   
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