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21.
Platelet adhesion and thrombus formation on subendothelium in platelets deficient in glycoproteins IIb-IIIa, Ib, and storage granules 总被引:22,自引:1,他引:22
Patients whose platelets are deficient in glycoprotein (GP) Ib, IIb- IIIa (thrombasthenia), or granule substances (storage pool deficiency, SPD) were studied to define further the properties of platelets that mediate platelet adhesion and thrombus formation on subendothelium. Both nonanticoagulated and citrated blood were exposed to everted, de- endothelialized rabbit vessel segments under controlled flow conditions and shear rates varying from 650 to 3,300 sec-1. Morphometry was used to measure platelet thrombus dimensions and the percentage of the subendothelial surface covered with contact (C) or spread (S) platelets. Adhesion was defined as C + S. The results in SPD demonstrated (1) reduced thrombus dimensions in delta-SPD (pure dense granule deficiency) in proportion to the magnitude of the dense granule defect; (2) an even greater reduction in thrombus dimensions in patients with combined deficiencies of alpha and dense granules (alpha delta-SPD); and (3) impaired platelet adhesion at several conditions in alpha delta-SPD and, in delta-SPD, a hematocrit-dependent impairment of adhesion in citrated blood at 2,600 sec-1. In thrombasthenia, platelets were present as a monolayer on the subendothelial surface in both nonanticoagulated and citrated blood, indicating an absolute requirement for GPIIb-IIIa in promoting platelet-platelet interaction at all shear rates and perfusion times. Two types of abnormalities in platelet-vessel wall interactions were observed. In nonanticoagulated blood, the percentage of platelets in the C phase was consistently increased at all shear rates, but C + S values were normal. These observations indicate that platelets deficient in GPIIb-IIIa do not spread normally on the subendothelial surface exposed to nonanticoagulated blood. With citrated blood, the C + S value in thrombasthenia was reduced at both 800 and 2,600 sec-1, as in von Willebrand's disease, and a similar degree of reduction (about 50%) was observed in normal blood treated with a monoclonal antibody to GPIIb- IIIa. The findings, together with theoretical considerations, are consistent with an hypothesis that GPIIb-IIIa mediates the spreading of platelets on subendothelium following the initial attachment through GPIb and that GPIIb-IIIa may be considered an adhesion site on the platelet membrane. Abnormalities of GPIIb-IIIa may, depending on the conditions of study, result in either increased values of C platelets or decreased values of C + S. The results of the study further suggest that a complex interaction of platelet granule factors and membrane GP mediate platelet adhesion and thrombus formation. 相似文献
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FJ Cowan JT Warner FD Dunstan WD Evans JW Gregory HR Jenkins 《Archives of disease in childhood》1997,76(4):325-329
The prevalence of osteopenia in children with inflammatory bowel disease (IBD) is unknown. The effect of nutritional state, disease activity, and steroid therapy on bone mineral content (BMC) of whole body, lumbar spine, and left femoral neck measured by dual energy x ray absorptiometry in 32 children with IBD was assessed by comparison with 58 healthy local school children. Using the control data, a predicted BMC was calculated taking into account bone area, age, height, weight, and pubertal stage. The measured BMC in children with IBD was expressed as a percentage of this predicted value (% BMC). Mean (SD) % BMC was significantly reduced for the whole body and left femoral neck in the children with IBD (97.0 (4.5)% and 93.1 (12.0)% respectively, p < 0.05). Of the children with IBD, 41% had a % BMC less than 1 SD below the mean for the whole body and 47% at the femoral neck. Reduction in % BMC was associated with steroid usage but not with the magnitude of steroid dose, disease activity, or biochemical markers of bone metabolism. In conclusion, osteopenia is relatively common in childhood IBD and may be partly related to the previous use of steroids. 相似文献
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M Khajehei S Ziyadlou Rad M Safari HR Tabatabaee F Kashefi 《Indian Journal of Community Medicine》2009,34(2):126-130
Background and Objective:
We conducted this study to evaluate and compare postpartum sexual functioning after vaginal and caesarean births.Materials and Methods:
This was a cross-sectional study that was carried out in postnatal health care in a hospital. A total of 50 primiprous women who had given birth 6-12 months ago and came to the hospital for postnatal care were asked to join the study. Forty of the women completed the entire questionnaire. Among these women, 20 delivered spontaneously with mediolateral episiotomy and 20 had elective caesarean section. Sexual function was evaluated by a validated, self-created questionnaire. A statistical evaluation was carried out by SPSS v.11. A two-part self-created validated questionnaire for data collection was administered regarding sexual function prior to pregnancy and 6-12 months postpartum.Results:
The median time to restart intercourse in the normal vaginal delivery with episiotomy (NVD/epi) group was 40 days and in the caesarean section (C/S) group was 10 days postpartum. The most common problems in the NVD/epi group was decreased libido (80%), sexual dissatisfaction (65%), and vaginal looseness (55%). In the C/S group, the most common problems were vaginal dryness (85%), sexual dissatisfaction (60%), and decreased libido (35%). There were clinically significant differences between the two groups regarding sexual outcomes, but these differences were not statically significant.Conclusion:
Postnatal sexual problems were very common after both NVD/epi and C/S. Because sexual problems are so prevalent during the postpartum period, clinicians should draw more attention to the women''s sexual life and try to improve their quality of life after delivery. 相似文献28.
B Waeber MD W Vetter MD R Dariolp MD U Keller MD HR Brunner MD 《International journal of clinical practice》1999,53(1):37-38
Compliance with antihypertensive therapy was monitored for three months using an electronic medication dispenser in 35 patients remaining hypertensive despite the once-daily administration of a blood pressure lowering drug (either as monotherapy or as fixed-dose combination therapy). During the monitoring of compliance, the treatment was unchanged but blood pressure decreased significantly (p<0.001) from 167.9/100.4 ± 16.3/7.2 mmHg (mean ± SD) to 152.5/90.9 ± 20.9/11.5 mmHg. The percentage of days with one opening per day was 80.8 ± 20.5. Thus, discussing with the patient about compliance with the prescribed drug regimen and monitoring compliance for a few months allows better control of blood pressure. This most likely reflects increased compliance with antihypertensive drug therapy. 相似文献
29.
Magnetic resonance angiography 总被引:6,自引:0,他引:6
Pulse sequences that permit selective detection of moving spins in a magnetic resonance image have been developed. Experiments were performed by the authors to produce projected angiographic data without the use of contrast agents, with the intensity of each image pixel determined by the macroscopic velocity of the detected spins. With this method, suppression of nonmoving spins is essentially complete, yielding a high dynamic range in signal intensity for detected vessels. Selective detection of moving spins is not dependent on pulsatile flow. Consequently, not only arterial structures, but also venous structures can easily be visualized. High-resolution angiographic images can be obtained by combining the flow experiment with surface coil techniques. 相似文献
30.
Patients infected with influenza A virus (IAV) are at increased risk for bacterial superinfections, and this occurs in association with depressed polymorphonuclear leukocyte (PMNL) function. Recently, we reported that in vitro exposure of human PMNL to granulocyte-macrophage colony-stimulating factor (GM-CSF) reverses IAV-induced cell dysfunction. The present study used an established animal model of IAV infection to examine whether G-CSF and/or GM-CSF can overcome IAV- induced PMNL dysfunction and thereby prevent secondary infections. Preliminary studies determined a dosing schedule of these cytokines that caused significant priming of chinchilla PMNL. In subsequent studies, animals were inoculated intranasally with IAV (day 1) followed 3 days later by Streptococcus pneumoniae, and administered daily intraperitoneal injections with a cytokine or placebo on days 3 through 9. Animals had blood obtained on multiple occasions for PMNL studies, and were followed-up for evidence of pneumococcal disease. Both cytokines caused significant priming of the PMNL chemiluminescence response and this was associated with reversal of the IAV-induced PMNL dysfunction. However, neither cytokine decreased the incidence of pneumococcal disease. 相似文献