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91.
Two live attenuated single-deletion mutant simian immunodeficiency virus (SIV) constructs, SIV239Deltanef and SIVPBj6.6Deltanef, were tested for their abilities to stimulate protective immunity in macaques. During the immunization period the animals were examined for specific immune responses and virus growth. Each construct generated high levels of specific immunity in all of the immunized animals. The SIV239Deltanef construct was found to grow to high levels in all immunized animals, with some animals remaining positive for virus isolation and plasma RNA throughout the immunization period. The SIVPBj6.6Deltanef was effectively controlled by all of the immunized animals, with virus mostly isolated only during the first few months following immunization and plasma RNA never detected. Following an extended period of immunization of over 80 weeks, the animals were challenged with a pathogenic simian-human immunodeficiency virus (SHIV) isolate, SIV89. 6PD, by intravenous injection. All of the SIV239Deltanef-immunized animals became infected with the SHIV isolate; two of five animals eventually controlled the challenge and three of five animals, which failed to check the immunizing virus, progressed to disease state before the unvaccinated controls. One of five animals immunized with SIVPBj6.6Deltanef totally resisted infection by the challenge virus, while three others limited its growth and the remaining animal became persistently infected and eventually died of a pulmonary thrombus. These data indicate that vaccination with attenuated SIV can protect macaques from disease and in some cases from infection by a divergent SHIV. However, if animals are unable to control the immunizing virus, potential damage that can accelerate the disease course of a pathogenic challenge virus may occur.  相似文献   
92.
Studies of parental influence on children's physical activity have had different results. Parental effect on physical activity during adolescence is less studied, and three generation studies have not been carried out. The purpose of our study was to examine intra- and intergenerational associations of leisure time physical activity among family members in three generations. Due to the major changes in society during this time, we also took into consideration the socioeconomic status of the adult subjects. The material consisted of 3254 twins at the age of 16, their parents and grandparents. Twins and their parents received a questionnaire in 1991-1993, which included questions about the health and lifestyle, socioeconomic status and leisure time physical activity. The parents' questionnaire also included questions about their own parents' leisure time physical activity and socioeconomic status. Based on these questions adolescents, parents and grandparents were classified into physical activity classes. The socioeconomic classification of parents and grandparents was based on their occupation. Intragenerational physical activity patterns were significantly associated with each other. Among adolescents the strongest correlation were between monozygotic boys (0.720) and monozygotic girls (0.638). Physical activity patterns were not associated between generations, but there was a significant difference between very active and inactive mothers concerning their daughters' physical activity. Farmers had the lowest proportion of very active subjects only among the parental generation. Because physical activity patterns do not appear to be transmitted from one generation to the next, it is probable that by constant training and education we can obtain the benefits of physical activity.  相似文献   
93.
RuO2 powders were prepared under different conditions to vary their properties. A study was made of the powder properties and electrical characteristics of thick film resistors (TFRs) containing an RuO2 powder as a conducting component. Both crystalline size and specific surface area varied with calcination temperature but the change in the washing solution had different effects upon the two relationships. Variations in the total pore volume produce differences in the specific surface area at the same crystalline size. The resistivity of TFRs decreases and the temperature coefficient of resistance (TCR) becomes more positive with decreasing crystalline size. TFRs having conductive powder of higher specific surface area at the same crystalline size show lower resistivity and higher TCR values. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   
94.
MHC-I binding peptides and beta 2 microglobulin (beta 2-m) can upregulate the MHC-I heavy chain expression on certain peptide transporter mutant cells. We have further studied this with normal cells and non-mutant cell lines. No MHC-I upregulation was seen with normal, resting or activated T cells. On mouse cell lines P815 and B16, both peptides and human beta 2-m gave an additive upregulation response. With the human small cell lung carcinoma H82, an optimal HLA.A2 binding peptide (GILGFVFTL) gave an upregulation response, whereas beta 2-m alone or in combination with this peptide had no effect. However, beta 2-m potentiated the response of H82 cells to a slightly longer peptide. Using mutant RMA-S cells, it was found that both Brefeldin A (BFA) and chloroquine, but not leupeptin, inhibited MHC-I upregulation response to both peptide and beta 2-m. In contrast to chloroquine, BFA also gave a reduction of background membrane MHC-I expression, presumably due to a block in Golgi transport. Human beta 2-m, which binds to RMA-S cells, and which is known to internalize into endosomes, did not reappear on the cell surface. When Db on RMA-S cells was upregulated by human beta 2-m, the sensitivity of these cells to Db restricted CTL cells increased. Even if beta 2-m did not upregulate the overall MHC-I expression on normal cells, it may still quantitatively increase the expression of optimally presented peptides and endosomal recycling many be important in this process.  相似文献   
95.
96.
This paper is concerned with the impact of a Mobile Dental System (MDS) on the providers and recipients of oral health care. It focuses more specifically on children as patients of the MDS and MDS personnel as clinicians and oral health educators. Data, which were quantitative and qualitative in nature were collected from children and MDS members by means of questionnaires and interviews. Results indicate that the children had acquired some oral health information from the MDS, but many were fearful of clinical procedures. MDS personnel were gratified that they were able to provide a service to an otherwise underserved community, but also considered themselves inadequate child managers and oral health educators. The lack of a permanent career structure created feelings of insecurity amongst MDS staff. Recommendations arising from this investigation are the need for permanent and comprehensive services for all members of the community, and improved working conditions and continuing education courses for MDS personnel.  相似文献   
97.
Ca45 kinetics was studied in 5, 15 and 30 min after potentiation. In the induction phase (1-5 min), the potentiation decreased the fraction of intracellular bound Ca. The 15-25 min potentiation the intra- and extracellular Ca levels was equal to the control ones. In 30 min, a considerable redistribution of Ca in the cells occurred.  相似文献   
98.
PURPOSE: Venous aneurysms have been reported to occur in most major veins. These aneurysms may be misdiagnosed as soft tissue masses or as inguinal or femoral hernias. Venous aneurysms of the deep system have been associated with deep venous thrombosis (DVT) and pulmonary embolism (PE). To more precisely characterize these lesions, we reviewed our experience with the disease. METHODS: A retrospective analysis of our experience over 22 years was performed. The presentation and management of these lesions were reviewed and compared with the literature. RESULTS: Thirty-nine venous aneurysms were reported in 30 patients. There were 14 men and 16 women. The patients' ages ranged from 3 to 75 years. Thirty aneurysms were located in the lower extremities, four in the upper extremity, and five in the internal jugular vein. Fifty-seven percent of lower extremity aneurysms occurred in the deep system. Patients' symptoms were a mass (75%) associated with pain (67%) and swelling (42%). Thromboembolism occurred in six patients, DVT in three, and PE in three. Eight of nine patients (89%) who had aneurysms of the superficial venous system had their condition misdiagnosed. Diagnosis was made by phlebography (60%), color flow duplex scanning (27%), continuous-wave Doppler scanning (10%), or magnetic resonance imaging (10%). The aneurysm size ranged from 1.7 to 6.0 cm. Management consisted of tangential excision in five (17%), total excision in 23 (77%), and observation in seven (6%). CONCLUSIONS: Venous aneurysms are unusual vascular malformations that occur equally between the sexes and are seen at any age. Most patients have a painful mass of the extremity, and diagnosis is achieved by radiologic examination. Superficial venous aneurysms of the inguinal region are often misdiagnosed. Thromboembolism is more common in aneurysms involving the deep venous system. Because of their potential morbidity, management should be surgical in the majority of cases.  相似文献   
99.
Disruptions in the mucosal lining of the gastrointestinal tract reseal by epithelial cell migration, a process termed restitution. We examined the involvement of laminin isoforms and their integrin receptors in restitution using the intestinal epithelial cell line T84. T84 cells express primarily laminins 5, 6, and 7 as indicated by immunostaining using laminin subunit-specific monoclonal antibodies (MAbs). A MAb (BM2) specific for the laminin alpha 3 subunit, a component of laminins 5, 6, and 7, completely inhibited the closure of mechanical wounds in T84 monolayers. Confocal microscopy using MAbs BM2 (laminin alpha 3 subunit) and 6F12 (laminin beta 3 subunit) revealed that laminin-5 is deposited in a basal matrix that extends into the wound. The MAbs 4E10 (laminin beta 1 subunit) and C4 (laminin beta 2 subunit) stained the lateral membranes between T84 cells. This staining was enhanced in cells adjoining wounds. Because T84 cells stained faintly with MAbs 4C7 (laminin alpha 1 subunit) and with MAbs 4F11 and 1B4 (laminin alpha 2 subunit), we suggest that expression of laminins 6 and 7 is enhanced in response to wounding. The alpha 3 beta 1 integrin and the alpha 6-containing integrins function in wound closure because MAbs specific for the beta 1 integrin subunit (MAb13), the alpha 3 subunit (IVA5), and the alpha 6 subunit (2B7) potently inhibited T84 migration into wounds. Immunofluorescence using UMA9, a beta 4-integrin-specific MAb, revealed that alpha 6 beta 4 integrin exists in a Triton-X-100-insoluble structure at the basal surface and that the staining of this structure is enhanced in cells adjoining wounds. In addition, a Triton-X-100-soluble pool of alpha 6 beta 4, as well as alpha 3 beta 1 and presumably alpha 6 beta 1, was found along lateral surfaces of T84 cells. On flattened cells adjoining wounds, staining for these integrins was distributed diffusely, suggesting a redistribution that accompanies cell migration. Taken together, these data suggest that wound-induced epithelial cell migration is a finely tuned process that is dependent upon the regulated function and localization of specific laminins and their integrin receptors.  相似文献   
100.
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