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排序方式: 共有363条查询结果,搜索用时 15 毫秒
91.
The regulation of human factor V by a neutrophil protease   总被引:1,自引:0,他引:1  
Oates  AM; Salem  HH 《Blood》1987,70(3):846-851
Neutrophils activated with serum opsonized zymosan, soluble heat- aggregated IgG, and ionophore A23187 in the presence of calcium release a material capable of initially activating factor V. Subsequent inactivation of factor V was only observed with neutrophil releasate derived from IgG and ionophore. In this study we examine the nature of this neutrophil activity and investigate its role in the regulation of factor V/Va. From early in the fractionation it was apparent that the cells contained different enzymes capable of cleaving factor V. The most active of these was isolated and found to be an isomer of human neutrophil elastase. The purified protease caused a dose-dependent activation of isolated factor V to a maximum of threefold. On sodium dodecyl sulfate-polyacrylamide gel electrophoresis, single-chain factor V was cleaved to form intermediates of 100 and 91 kilodaltons (kD). Coagulant activity correlated with the formation of a 97-kD heavy and 77-kD light chain. On prolonged incubation the formed factor Va(e) was inactivated in association with proteolysis of the 97-kD band to smaller peptides and cleavage of the 77-kD light chain to a molecular weight of 75 kD, which is similar to thrombin-activated factor Va light chain. Neutrophil elastase also caused rapid inactivation of thrombin- activated factor V, factor Va(t). These observations suggest that elastase cleaves factor V at sites distinct from that by thrombin and therefore represents a novel factor V activation pattern. It is proposed that upon neutrophil activation elastase is secreted into the plasma milieu to initiate factor V activation. This serves to generate small amounts of thrombin that, in turn, by positive feedback fully activates factor V and thus amplifies the coagulation reaction.  相似文献   
92.
Ishii  H; Salem  HH; Bell  CE; Laposata  EA; Majerus  PW 《Blood》1986,67(2):362-365
Protein C activation by thrombin is significantly accelerated by the endothelial cell cofactor, thrombomodulin. In this study, we have developed a radioimmunoassay for thrombomodulin and have measured the cofactor content in several human tissues. The assay method detects as little as 2 ng of thrombomodulin. The highest thrombomodulin content was found in lung and placenta, but the antigen was also detected in spleen, pancreas, liver, kidney, skin, heart, and aorta. Unexpectedly, thrombomodulin was absent from brain. Extracts from cerebral cortex, cerebellum, centrum semiovale, midbrain, basal ganglia, pons, and medulla were devoid of thrombomodulin. In contrast, thrombomodulin antigen is present in extracerebral intracranial vessels, including basilar and internal carotid arteries and choroid plexus, as well as in endothelium of the pia-arachnoid.  相似文献   
93.
Molecular cloning of a cDNA encoding canine factor IX   总被引:9,自引:1,他引:9  
Evans  JP; Watzke  HH; Ware  JL; Stafford  DW; High  KA 《Blood》1989,74(1):207-212
Factor IX (F.IX) is a vitamin K-dependent plasma protein, a deficiency of which results in hemophilia B. A canine model of hemophilia B exists; attempts to use this model for gene transfer experiments or characterization of the hemophilic defect require elucidation of normal canine F.IX structure. We report the isolation and characterization of the coding region for canine F.IX cDNA. Canine F.IX possesses 86% identity at the amino-acid level with human F.IX. The leader peptide, Gla domain, EGF domains, and the carboxy-terminal portion of the heavy chains show extensive sequence conservation between the canine and human. All Glu residues undergoing gamma-carboxylation in humans are conserved in canines. The complete coding sequence for canine F.IX has been determined, and the derived translation product has been analyzed. A similar approach should allow identification of the causative mutation in canine hemophilia B. Furthermore, this clone may prove a valuable resource in gene transfer experiments for this disease.  相似文献   
94.
The administration of moderate to high doses of corticosteroids is associated with bone loss. This probably results from the uncoupling of bone formation (decreased) and bone resorption (unchanged or increased). We examined the effect of low-dose (10 mg/day) prednisone (LDP) and the possible mitigating effects of calcium and 1.25 (OH)2 vitamin D (calcitriol) on calcium and bone metabolism in eight healthy, young male volunteers. The study consisted of four observation periods: in the first period, LDP was prescribed during 1 week; in the second, third and fourth periods, calcium (500 mg/day), calcitriol (0.5 micrograms b.i.d.) and calcium in combination with calcitriol, respectively, were added to LDP. Bone formation was measured by means of serum osteocalcin, carboxy-terminal propeptide of type 1 procollagen (P1CP) and alkaline phosphatase, bone resorption by means of urinary excretion of calcium, hydroxyproline, (free and total) pyridinoline, (free and total) deoxypyridinoline and serum carboxy-terminal cross- linked telopeptide of type 1 collagen (1CTP). Dietary calcium and sodium intake were maintained at a stable level during the entire study period. Treatment with LDP led to a decrease in osteocalcin, P1CP and alkaline phosphatase (all P < 0.01). Urinary excretion of pyridinolines, hydroxyproline and serum 1CTP did not increase, but remained unchanged or slightly reduced (P < 0.05), depending on the time of measurement and the marker of bone resorption. Parathyroid hormone (PTH) (insignificantly) increased during LDP (+19%) and LDP plus calcium (+14%), but decreased during supplementation with calcitriol (-16%) and calcium/calcitriol (-44%; P < 0.01). Urinary excretion of calcium increased during treatment with LDP and calcitriol (P < 0.05) and calcium/calcitriol (P < 0.05). It is concluded that LDP has a negative effect on bone metabolism, since bone formation decreased while bone resorption remained unchanged or decreased slightly. The increase in PTH during LDP could be prevented by calcitriol combined with calcium supplementation.   相似文献   
95.
Autologous stem cell transplantation with or without in vitro lymphocyte depletion has been suggested as a new treatment option for severe autoimmune diseases. We describe five patients with autoimmune diseases (CREST syndrome, myasthenia gravis and Hashimoto's thyroiditis, systemic lupus erythematosus, atopic dermatitis, and rheumatoid arthritis) who underwent autologous bone marrow (n = 1) or peripheral blood progenitor cell (n = 4) transplantation with unmanipulated grafts as treatment for the autoimmune disease in one case or as treatment for a malignant disorder with a concomitant autoimmune disorder in four cases. In all patients serological and clinical signs of the autoimmune disease recurred early or persisted. These observations should be regarded as a cautionary note concerning the efficacy of high-dose therapy followed by transplantation of unmanipulated autologous stem cells for treatment of severe autoimmune diseases.  相似文献   
96.
Although Nepal has an epidemic of early-onset, aggressive, advanced breast cancer, breast cancer knowledge and screening practices of Nepalese women have not been assessed. This paper summarises the results of a physician-administrated survey of gynaecologic inpatients (n= 100) admitted between 1 December 2009 and 31 January 2010 at a Nepalese University. Mean knowledge score of the participants was 65%, significantly higher among highly educated women (P= 0.008), professionals (P= 0.014) and women counselled during medical visits (P= 0.030). Study participants, including highly educated women, had many misconceptions. This included lack of awareness of painless nature and non-lump symptoms of breast cancer as well as the belief that traditional health care can be curative. The majority of participants were unaware of clinical breast examination (68%) and mammography (56%). Only 10% of the participants had undergone breast evaluation in the last 2 years. The practice of breast evaluation was more common among Buddhists (P= 0.043), and women counselled during medical visits (P < 0.001), with high economic status (P= 0.022), higher education (P= 0.013) and a family history of breast cancer (P= 0.049). Counselling during medical visits and higher education level were associated with better knowledge of and screening practices for breast cancer in the studied population.  相似文献   
97.
Cryptococcus neoformans is the most common cause of life threatening meningoencephalitis in HIV-infected patients. Diagnosis is based on tests for cryptoccocal antigen in serum and cerebrospinal fluid, and on culture of the organism. We present a case of AIDS-related cryptococcal meningoencephalitis unresponsive to antifungal combination therapy, despite of evidence of fungal susceptibility in vitro. Significant decreases in cryptococcal antigen titers in serum and cerebrospinal fluid did not correlate with progress in disease and fatal outcome.  相似文献   
98.

Background  

Pelvic organ prolapse is a common health problem, affecting up to 40% of parous women over 50 years old, with significant negative influence on quality of life. Vaginal hysterectomy is currently the leading treatment method for patients with symptomatic uterine prolapse. Several studies have shown that sacrospinous fixation in case of uterine prolapse is a safe and effective alternative to vaginal hysterectomy. However, no large randomized trials with long-term follow-up have been performed to compare efficacy and quality of life between both techniques.  相似文献   
99.
For patients with diabetes mellitus and diabetic foot syndrome customized orthopedic shoes represent the most effective treatment to avoid foot ulceration and amputation. A total of 53 patients suffering from diabetes and treated with customized orthopedic shoes for more than 5 years were included in the study. Of the patients 91% had peripheral artery occlusion disease, polyneuropathy and diabetic neuropathic osteoarthropathy (DNOAP) and in nearly 25% amputation of one limb had already been carried out. The incidence of ulcers over a time period of 5 years was assessed from the patient records and questioning the patients. Questions on the duration of wearing orthopedic shoes, the durability of the shoes and resulting pain were also included. All patients except for one had problems walking on uneven surfaces. Of the patients 89% claimed to have used their shoes always or nearly always and 25% of the shoes had to be replaced after 1 year. The incidence of ulcers was 38% after 5 years. Treatment with customized orthopedic shoes is an effective method to prevent ulcers and amputation. To be successful it is necessary to control that the shoes are made correctly. Not all shoes last as long as 2 years.  相似文献   
100.
Capitalizing on existing IT investments, INTEGRIS Health, a 15-hospital system in Oklahoma, is applying business process integration (BPI) methodology and technology to leverage legacy systems and staff resources. The resulting project uses manual (human) and system tasks to compare real-time information across systems to eliminate preventable adverse drug events caused by medication ordering errors. Clinicians can quickly see where potential safety risks are occurring and change medication orders to prevent harm to the patient.  相似文献   
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