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61.
Silica inhalation predisposes workers to bacterial infection and impairments in pulmonary defense function. In this study,
we evaluated the effect of pre-exposure to silica on lung defense mechanisms by use of a rat pulmonary Listeria monocytogenes infection model. Male Fischer 344 rats were exposed by inhalation to filtered air or silica (15 mg/m3× 6 h/day × 5 days/wk). After 21 or 59 days of silica exposure, the rats were inoculated intratracheally with 5 × 103
L. monocytogenes. At 0 (noninfected controls), 3, and 7 days after infection, the left lungs were removed, homogenized, and the number of
viable L. monocytogenes was counted after an overnight culture at 37° C. Bronchoalveolar lavage (BAL) was performed on the right lungs. Alveolar
macrophages (AM) were collected, and the AM production of chemiluminescence (CL), an index of reactive oxygen species generation,
was measured. The number of lavagable neutrophils (PMNs) and acellular BAL lactate dehydrogenase (LDH) activity were determined
as indices of inflammation and injury, respectively. Pre-exposure to silica for 59 days caused substantial increases in PMN
number and LDH activity compared with the air controls, whereas silica inhalation for both 21 and 59 days significantly enhanced
the pulmonary clearance of L. monocytogenes compared with air controls. Dramatic elevations were also observed in zymosan- and phorbol myristate acetate (PMA)–stimulated
CL production by lung phagocytes recovered from rats pre-exposed to silica for 59 days. These results demonstrate that short-term
exposure to inhaled silica particles activates lung phagocytes, as evidenced by increases in reactive oxygen species. This
up-regulation in the production of antimicrobial oxidants is likely responsible for the enhancement in pulmonary clearance
of L. monocytogenes observed with short-term silica inhalation.
Accepted for publication: 2 October 2000 相似文献
62.
Marrow transplantation with or without donor buffy coat cells for 65 transfused aplastic anemia patients 总被引:4,自引:3,他引:4
Storb R; Doney KC; Thomas ED; Appelbaum F; Buckner CD; Clift RA; Deeg HJ; Goodell BW; Hackman R; Hansen JA; Sanders J; Sullivan K; Weiden PL; Witherspoon RP 《Blood》1982,59(2):236-246
Sixty-five multiply transfused patients with severe aplastic anemia were given cyclophosphamide followed by grafts anemia were given cyclophosphamide followed by grafts from HLA-identical siblings. The effect of the administration of viable donor buffy coat cells following the marrow inoculum was evaluated with regard to graft rejection and survival. Results in 43 patients so treated are presented along with those in 22 concurrent patients given marrow alone. Most patients given buffy coat had positive in vitro tests of sensitization indicating a high risk for graft rejection, while all but one of the patients given marrow alone had negative tests. Thirty of the 43 (70%) patients given marrow and buffy coat are alive between 10 and 61 mo (median 36) after grafting; 4 died after graft rejection and 6 with acute or chronic graft-versus-host disease (GVHD). Eleven of the 22 (50%) patients given marrow alone are alive between 29 and 65 mo (median 52); 7 died after graft rejection and 3 with GVHD. The addition of buffy coat cell infusions to the marrow inoculum reduced the risk of rejection and increased survival in the currently reported transfused patients when compared to patients grafted before 1976. However, there was an increased risk of chronic GVHD. Recipients of marrow from female donors survived slightly better (73%) than recipients of male marrow (58%). 相似文献
63.
X-linked chronic granulomatous disease: correction of NADPH oxidase defect by retrovirus-mediated expression of gp91-phox 总被引:3,自引:0,他引:3
Chronic granulomatous disease (CGD) is an inherited immunodeficiency resulting from the inability of an individual's phagocytes to produce superoxide anions because of defective NADPH oxidase. The disease may be treated by bone marrow transplantation and as such is a candidate for somatic gene therapy. Two thirds of patients have defects in an X- linked gene (X-CGD) encoding gp91-phox, the large subunit of the membrane cytochrome b-245 component of NADPH oxidase. Epstein-Barr virus-transformed B-cell lines from patients with CGD provide a model system for the disease. We have used retrovirus-mediated expression of gp91-phox to reconstitute functionally NADPH oxidase activity in B-cell lines from three unrelated patients with X-CGD. The protein is glycosylated and membrane associated, and the reconstituted oxidase is appropriately activated via protein kinase C. The kinetics of superoxide production by such reconstituted cells is similar to that of normal B-cell lines. These data show the potential of gene therapy for this disease. 相似文献
64.
Machiko R. Tomita Nadine M. Fisher Sujata Nair Dan Ramsey Kimberley Persons 《Physical & occupational therapy in geriatrics》2018,36(1):107-119
Aims: The aim of the study was to determine whether increased physical activities (PA) affect frailty for old women, 75 years and older (OO), compared to 60–74 years old (YO). Methods: This cross-sectional study measured 19 frailty indicators (muscle strength and endurance, balance, gait characteristics, and function), using 46 community-dwelling women. PA were divided into three levels by caloric expenditure per week (<2,000 kcal/week, 2,000–3,999 kcal/week, >4,000 kcal/week). Results: As PA level increased, a gap (=difference) between OO and YO narrowed for step length and function, but for quadriceps strength and endurance, a gap widened. Conclusions: Frailty progresses with aging but older women who engage in a high level of physical activity (>4,000 kcal/week) can increase mobility and functional capacity, but not for muscle strength and endurance. Starting regular resistance training activities early in the aging process is critical to improve or maintain muscle quality to offset age-related frailty. 相似文献
65.
66.
Genetic engineering of an H-2Dd/Q10b chimeric histocompatibility antigen: purification of soluble protein from transformant cell supernatants 下载免费PDF全文
D H Margulies A L Ramsey L F Boyd J McCluskey 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(14):5252-5256
We have constructed a recombinant class I gene in which 5' sequences of H-2Dd are linked to the 3' half of a Qa subregion gene, Q10b. This hybrid gene would be expected to direct the synthesis of a protein containing the N and C1 domains of H-2Dd covalently linked to the C2 domain of the secreted, nonpolymorphic, Q10b antigen. Following DNA-mediated gene transfer into mouse L cells, transformants were analyzed by radiolabeling and immunoprecipitation. These cells secreted a molecule reactive with anti-H-2Dd monoclonal antibodies that identify epitopes on the N and C1 domains as well as with an anti-Q10 carboxyl-terminal peptide antiserum. The H-2Dd-derived antigen is associated with beta 2-microglobulin and is readily purified in milligram amounts from culture supernatants by immunoaffinity chromatography. 相似文献
67.
Diagnostic accuracy of oropharyngeal cultures in infants and young children with cystic fibrosis. 总被引:3,自引:0,他引:3
M Rosenfeld J Emerson F Accurso D Armstrong R Castile K Grimwood P Hiatt K McCoy S McNamara B Ramsey J Wagener 《Pediatric pulmonology》1999,28(5):321-328
The objective of this study was to assess the diagnostic accuracy of oropharyngeal (OP) cultures relative to simultaneous bronchoalveolar lavage (BAL) cultures in very young children with CF, and to examine the effects of bacterial density, age, and study cohort on diagnostic accuracy. Respiratory culture data were analyzed from three independent, prospective studies involving simultaneous collection of 286 OP and BAL cultures from 141 children with CF <5 years of age. For predicting any growth of Pseudomonas aeruginosa (Pa) from the lower airway in subjects =18 months of age (mean age, 8 +/- 5 months), OP cultures had a sensitivity of 44% (95% CI 14%, 79%), specificity of 95% (90%, 99%), positive predictive value of 44% (14%, 79%), and negative predictive value of 95% (90%, 99%). Diagnostic accuracy was similar for Haemophilus influenzae (Hi). Specificity was significantly lower for Staphylococcus aureus (Sa). Sensitivity for all organisms improved if a positive lower airway culture was defined as >/=10(3) or >/=10(5) cfu/mL. Specificity for Pa declined significantly with increasing age. In children with CF <5 years of age, the specificity and negative predictive value of OP cultures for Pa are high, while the sensitivity and positive predictive value are poor. Thus, in this age range, a negative throat culture is helpful in "ruling out" lower airway infection with Pa. However, a positive culture does not reliably "rule in" the presence of Pa in the lower respiratory tract. These findings may have implications for study design and interpretation as well as clinical management of young children with CF. 相似文献
68.
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