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We have investigated the effects of mechanical elution of neutrophils from nylon-wool fiber (NWF) using the scanning electron microscope and biochemical analysis of elution fractions. We have determined that mechanical removal of neutrophils from nylon-wool fiber disrupts neutrophils adherent to nylon-wool fiber and augments release of granules, release of peripheral cytoplasmic fragments, and release of lactic dehydrogenase, a soluble cytoplasmic enzyme. Mechanical shearing of the adherent cell, and not adherence per se, causes the fragmentation. The extent of fragmentation is proportional to the NWF surface area available to neutrophils and is maximal at the temperature for optimal adherence and spreading. Agents that decrease cell spreading (n-ethylmaleimide and cold) diminish fragmentation. Cytochalasin B, an agent that destabilizes the neutrophil cortex, increases fragmentation. Fragmentation may be an important contributing cause of the abnormal morphology, function, and in vivo survival of nylon-wool-fiber procured human neutrophils. The prevention of fragmentation would appear to be necessary to insure the procurement of optimally functioning cells. Elution of NWF-adherent neutrophils in the cold might be a practical way to diminish neutrophil damage during clinical filtration leukapheresis. 相似文献
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Alloimmunization to platelets in heavily transfused patients with sickle cell disease 总被引:2,自引:0,他引:2
Bone marrow transplantation (BMT) is now an option for some patients with sickle cell disease (SCD). Many SCD patients are multiply transfused with red blood cells (RBCs), and may be immunized to alloantigens other than erythrocyte antigens. Because platelet refractoriness is a significant complication during BMT, we wished to determine the prevalence of alloimmunization to platelets in transfused SCD patients. Sera collected from 47 transfused and 14 untransfused SCD patients were screened for HLA and platelet-specific antibodies. Transfusion and RBC antibody histories were reviewed. A subset of the patients were rescreened 1 year later. Eighty-five percent of patients with at least 50 RBC transfusions (22 of 26), 48% of patients with less than 50 transfusions (10 of 21), and none of 14 untransfused patients demonstrated platelet alloimmunization (P < .05). Platelet alloimmunization was more prevalent than RBC alloimmunization (20% to 30%). Half of the platelet reactivity was chloroquine-elutable. Eighteen of 22 patients (82%) on chronic RBC transfusion remained platelet-alloimmunized 11 to 22 months after initial testing. In summary, 85% of heavily transfused SCD patients are alloimmunized to HLA and/or platelet-specific antigens. These patients may be refractory to platelet transfusion, a condition that would increase their risk during BMT. Leukodepletion in the transfusion support of SCD patients should be considered to prevent platelet alloimmunization. 相似文献
6.
Jerard M Selvam F Wares M Perumal P G Gopi G Sudha V Chandrasekaran T Santha 《The international journal of tuberculosis and lung disease》2007,11(2):161-167
BACKGROUND: Although case detection is above 70% in Tamil Nadu after DOTS implementation, an assessment of the timeliness of patient diagnosis and treatment is still needed. OBJECTIVE: To study the health-seeking behaviour of new smear-positive pulmonary tuberculosis (PTB) patients treated at government facilities. METHODS: New smear-positive patients diagnosed and treated between January and March 2003 in government facilities of randomly selected blocks in Tamil Nadu were interviewed using a semi-structured interview schedule. RESULTS: Of 601 patients interviewed, 65% contacted a provider within 28 days. The first contact was governmental for 47% and non-governmental for 53%. Median total, patient and provider delays were respectively 62, 28 and 28 days; provider delay was 9 days with government and 50 with private provider. In multivariate analysis, patient delay was significantly associated with smoking (P < 0.001) and mode of travel (P < 0.01), and provider delay with first consultation with a private provider (P < 0.001) and distance > 5 km from the health facility (P < 0.01). Twenty-five per cent of patients took more than two actions before diagnosis. CONCLUSION: Community awareness of TB needs to be increased. Greater private sector involvement in the Revised National Tuberculosis Control Programme is essential to reduce provider delay. Referral and sputum transportation to the diagnostic facility should be given priority. 相似文献
7.
Immunohistochemical localization of membrane and alpha-granule proteins in human megakaryocytes: application to plastic-embedded bone marrow biopsy specimens 总被引:12,自引:2,他引:12
Using a new technique for antigen localization, we have demonstrated platelet proteins in megakaryocytes in plastic-embedded biopsy specimens of normal human bone marrow. In a series of 25 specimens, megakaryocytes showed labeling with antibodies to the integral membrane glycoproteins IIIa, IIb, and the IIb-IIIa complex; granule membrane protein 140; and five alpha-granule matrix proteins: thrombospondin, factor VIII-related antigen, beta-thromboglobulin, platelet factor 4, and fibrinogen. The antibodies to the membrane glycoproteins IIIa, IIb, and IIb-IIIa produced diffuse cytoplasmic staining and heavier staining on the plasma membrane, whereas the antibodies to the alpha-granule matrix proteins produced a distinct granular staining within the cytoplasm. Staining for granule membrane protein 140 was also granular in distribution. Rare mononuclear cells consistent with megakaryocyte precursors were labeled with these markers. Other enzyme histochemical and lectin-binding studies showed that the enzyme alpha-naphthyl acetate esterase, the lectin Ulex europaeus I, and the periodic-acid Schiff reaction were consistent, but not specific, markers of megakaryocytes. This immunohistochemical technique should facilitate the examination of qualitative and quantitative changes in megakaryocytes in a variety of physiologic and pathologic processes. 相似文献
8.
Human papillomavirus (HPV) infections have received considerable attention in recent years. Of the 120 or so known types of the virus, some cause a variety of benign wart‐like lesions of the skin and genital and oral mucosae, whilst others are aetiologically associated with cervical and anogenital cancers. Recent epidemiologic evidence suggests that HPV may also be an independent risk factor for oropharyngeal cancer. In this context it has been suggested that HPV virus may modulate the process of carcinogenesis in some tobacco and alcohol induced oropharyngeal cancers and act as the primary oncogenic agent for inducing carcinogenesis among non‐smokers. Dental practitioners have a major role in detecting all lesions of the oral mucosa caused, or possibly caused, by HPV. This paper briefly reviews the current state of knowledge of molecular and clinical aspects of HPV infections of the oral mucosa. 相似文献
9.
Platelet-derived growth factor (PDGF) is a potent mitogen for many cultured connective tissue cells. It is present in concentrated form within the platelet alpha-granules and is believed to be released during platelet degranulation at sites of vascular injury. We have used a sensitive radioreceptor assay to measure PDGF levels in whole blood serum from normal humans [17.5 +/- 3.1 (SD) ng/mL] and baboons (2.7 +/- 1.2 ng/mL). PDGF was not detected in plasma from either species. In addition, plasma was found to substantially reduce the ability of added purified PDGF to bind to the cell surface PDGF receptor on cultured cells, suggesting that plasma may contain a PDGF-binding protein that would serve to inactivate PDGF released into plasma. Calculations of PDGF concentrations in serum have been corrected for the effects of the binding protein. 125I-PDGF injected intravenously into normal baboons was cleared rapidly from the plasma (t1/2 = two minutes). The rapid clearance of 125I-PDGF did not result from iodination damage, as purified unlabeled PDGF was cleared with comparable kinetics. The rapid clearance of purified and iodinated PDGF did not result from changes in PDGF structure during purification or from removal of PDGF-associated proteins during purification, as PDGF present in freeze-thaw lysates of fresh platelets was cleared equally rapidly. We conclude that release of PDGF at sites of vascular injury would greatly increase the local concentration of PDGF and that PDGF not localized to the site of injury would be rapidly cleared from the circulation. 相似文献
10.
M K A Kumar P K Dewan P K J Nair T R Frieden S Sahu F Wares K Laserson C Wells R Granich L S Chauhan 《The international journal of tuberculosis and lung disease》2005,9(8):870-876
BACKGROUND: Efforts to intensify global tuberculosis (TB) control are limited by difficulties in coordinating with private doctors. More than half of Indian TB patients may initially consult a private provider, but many are neither diagnosed accurately nor treated effectively. We established and evaluated a public-private partnership based on surveillance of TB detected in private laboratories and use of standardised directly observed treatment regimens. METHODS: In one district, the governmental TB control programme offered training in microscopy to all large private sector laboratories, and educated private physicians on the importance of microscopy for TB diagnosis. We reviewed records from participating private laboratories and all publicly diagnosed patients. RESULTS: Of 2328 pulmonary TB patients registered from July 2001 to December 2002, 404 (17%) were detected in the private sector. The annual new AFB-positive case notification rate increased by 21%, from 27.8/100,000 in 2000 to 33.5/100,000 in 2002. Surveillance at private laboratories found an additional 260 nonregistered AFB-positive patients. CONCLUSIONS: This public-private partnership substantially increased TB case detection and established a sustainable framework for private sector involvement in TB control. In the setting of a strong public sector programme, the combination of active surveillance of private laboratories along with physician sensitisation is a promising approach to improve TB case detection. 相似文献