Importance of anticoagulant concentration for the activation of some human blood clotting factors

The effects of varying concentrations of decalcifying salts and of type of surfaces on clotting tests of plasma were studied. The results indicated that plasma obtained with 0.025 M sodium oxalate, 1 part to 9 parts of blood stored either at 3 °C or at room temperature, no matter if in glass or in siliconed tubes, always shortened its prothrombin time. Similar results in samples drawn with 0.125 M sodium citrate, and stored either in glass or in siliconed tubes were obtained, but with a very weak effect. No activation either of prothrombin or of Factor V or of Factor X was observed.

Activation of Factor VII would explain the shortening of the prothombin time.

A reacting system that uses a very small amount of calcium, and that activates Factor VII appeared responsible for that effect.     

桡骨远端骨折背侧钢板固定与掌侧钢板固定的比较

根据四项回顾性队列研究的结论,目前尚不能推断在治疗桡骨远端骨折时,是采用背侧钢板固定有利还是采用掌侧钢板固定有利.研究认为采用背侧钢板固定更有利于掌倾角的恢复,但是,总体上两种固定方法在其他影像学表现和功能活动度评价方面没有显著性差异.     

The prevalence and outcomes of in-hospital acute myocardial infarction in the Department of Veterans Affairs Health System

BACKGROUND: Most studies of the epidemiology and treatment of acute myocardial infarction (AMI) have focused on patients who experienced onset of their symptoms in the community and then presented to the hospital. There are, however, patients whose symptoms of AMI begin after hospitalization for other medical conditions. The purposes of this study were to determine the prevalence of in-hospital AMI in the Veterans Health Administration (VHA) and to compare baseline characteristics, treatments, and outcomes according to whether individuals presented with AMI or had an in-hospital AMI. METHODS: This was a retrospective cohort study of 7054 veterans who were hospitalized for AMI in 127 VHA medical centers between July 2003 and August 2004. The main outcome measure was 30-day mortality. Key covariates included age, body mass index, admission systolic blood pressure, heart rate, previous use of lipid-lowering drugs, elevated admission troponin value, prolonged and/or atypical chest pain on admission, and ST-segment elevation on the initial electrocardiogram. RESULTS: There were 792 patients (11.2%) who had AMI while hospitalized for other medical conditions. These patients differed substantially from those who presented to the hospital with AMI. The odds of 30-day mortality were greater in the in-hospital group (odds ratio, 3.6; 95% confidence interval, 3.1-4.3; P<.001) and remained higher after statistical adjustment (odds ratio, 2.0; 95% confidence interval, 1.7-2.4; P<.001). CONCLUSION: Although most attention has been paid to patients with AMI admitted via the community emergency medical system or through the emergency department, AMI occurring during hospitalization for other medical problems is an important clinical problem.     

Thrombendvenectomy for Organized Portal Vein Thrombosis at the Time of Liver Transplantation

OBJECTIVE: To determine the efficacy of portal thrombendvenectomy in cases of portal vein thrombosis at the time of orthotopic liver transplantation. SUMMARY BACKGROUND DATA: Portal vein thrombosis (PVT) has been reported to have an incidence of 2% to 39% in end-stage liver disease. Multiple techniques have been suggested to treat this finding. Several reports have suggested suboptimal results after liver transplantation in recipients with PVT. METHODS: The authors prospectively collected data on 1,546 patients who underwent an initial orthotopic liver transplant at the authors' institution between December 1984 and October 1999. There were 820 male patients and 726 female patients. All recipients received either cyclosporine or tacrolimus immunosuppression. Intraoperative flows of the portal vein and hepatic artery were routinely measured. Duplex sonography was routinely performed on the first postoperative day and routinely 1, 2, 5, and 10 years after transplantation. Eighty-five patients underwent thrombendvenectomy for organized thrombus partially or completely occluding the portal vein. Postoperative treatment included low-molecular-weight dextran for 48 hours and daily aspirin for 3 months. There were 53 male patients and 32 female patients. The PVT group was compared with a control group consisting of transplant recipients without PVT. RESULTS: When compared with the control group, PVT patients were older at the time of transplantation and had a higher incidence of liver disease secondary to cryptogenic cirrhosis and Laennec's cirrhosis. There were no significant differences among both groups for 1-, 3-, and 6-year patient and graft survival rates. CONCLUSIONS: Thrombendvenectomy provides a rapid resolution of an otherwise complex problem. It is the authors' procedure of choice in cases of organized PVT at the time of transplantation. Operative time and length of stay in the intensive care unit are not prolonged, and patient and graft survival rates are not compromised.     

Monitoring of pulmonary ventilation function and respiratory symptoms in cotton-processing workers

A follow-up study in cotton workers (35 female and 31 male) was performed ten years after the original cross-sectional study. The prevalence of byssinosis considerably increased during the follow-up study in female (22.9%; 42.9%) and in male (25.8%; 51.6%) workers. Similarly, the prevalence of almost all respiratory symptoms was significantly higher during the follow-up study than at the time of the initial study. Significant acute reductions of FVC and FEV1 during the work shift were recorded in both surveys. The mean annual decline in ventilatory capacity was greater than expected for both female (FVC: -0.036 L/year; FEV1: -0.059 L/year) and male workers (FVC: -0.059 L/year; FEV1: -0.068 L/year). The mean total airborne dust concentration was 3.95 mg/m3 with an average respirable dust concentration of 0.97 mg/m3. Our study demonstrated an association between exposure to cotton dust and increasing prevalence of respiratory symptoms and progressive impairment of ventilatory capacity.     

Influence of glass and anticoagulant concentration on improvement of factor X deficiency tests

Normal human blood received in 0.02 M sodium oxalate (1 part to 9 parts of blood) in 16 × 100 mm glass tubes, at 37 °C, always clotted. Blood from severe Factor X deficiency received in 0.02 M sodium oxalate did not clot. The prothrombin time of the 0.02 M oxalate Stuart plasma was much shorter than the prothrombin time of the 0.1 M oxalate Stuart plasma. The prothrombin time of the 0.1 M oxalate Stuart plasma was shorter with 0.02 M than with 0.01 M CaCl₂. The Stypven Time of this 0.1 M oxalate plasma was very prolonged but was almost normal with the 0.02 M oxalate plasma. Almost normal prothrombin time (with human brain thromboplastin) of a ten times concentrated 0.02 M oxalate Stuart plasma was observed. With 0.01 ml of a 1 % 0.02 M oxalate Stuart plasma for 0.1 ml of Factor VII deficient plasma the prothrombin time became normal. Same experiment with 0.1 M oxalate Stuart plasma did not normalize the prothrombin time.

Very abnormal kaolin partial thromboplastin time for the 0.1 M oxalate Stuart plasma and completely normal for the 0.02 M oxalate Stuart plasma was observed. We can postulate that the activation of the contact factors (F-XII, F-XI) occurs with traces of calcium ions not removed by the anticoagulant. Consequently, a condition can be generated which makes more manifest the limited amounts of normal F-X molecules in the deficient plasma.