Prediction of intermittent claudication, ischemic stroke, and other cardiovascular disease by detection of abdominal aortic calcific deposits by plain lumbar radiographs

There has been little attention to vascular calcium testing for generalized assessment of cardiovascular disease (CVD) outcomes, such as intermittent claudication (IC) and ischemic stroke (IS). We hypothesize that aortic calcium is an important predictor of CVD outcomes. Lumbar x-rays were obtained in 848 men and 1,301 women (mean ages 59.7 and 60.1 years, respectively) from the original cohort of the Framingham Heart Study. Abdominal aortic calcium (AAC) deposits were graded using a previously validated scale. Participants were categorized according to a 10-year Framingham coronary heart disease (CHD) risk score. Multivariable Cox proportional hazards analyses were performed to relate AAC to CVD outcomes. There were 199 IC events, 201 IS events, 702 CHD events, and 1,121 CVD events during 32 years of follow-up. Multivariable adjusted hazard ratios for the third versus first AAC tertile in the combined cohort were 1.68 (95% confidence interval [CI] 1.12 to 2.50) for IC, 1.73 (95% CI 1.12 to 2.65) for IS, 1.59 (95% CI 1.26 to 2.00) for CHD, and 1.64 (95% CI 1.37 to 1.97) for CVD. Hazard ratios for IC and IS were similar in magnitude to those for CHD and CVD. A high AAC score was associated with significantly higher incidence of events in subjects at intermediate Framingham CHD risk for all end points. Risk prediction based on cardiovascular risk factors improved for most outcomes when AAC was added. In conclusion, there was a graded, increasing, and independent association of AAC with incident IC and IS, similar in magnitude to risks predicted for CHD and CVD. AAC appears to be useful for risk stratification in patients at intermediate CHD risk.     

Human herpesvirus 6: infection and disease following autologous and allogeneic bone marrow transplantation

Human herpesvirus 6 activity (HHV-6) was studied in 15 allogeneic and 11 autologous marrow transplantation patients. After transplantation, HHV-6 was isolated from the peripheral blood mononuclear cells of 12 of 26 patients (6 allogeneic and 6 autologous). All isolates were variant B. Eleven of 26 and 12 of 19 patients showed salivary shedding of HHV-6 DNA before and after transplantation, respectively. The antibody titer increased in 7 of 26 patients. Thus, 23 of 26 patients showed evidence of active HHV-6 infection either by virus isolation, salivary shedding, or increases in antibody titers. The fraction of saliva specimens positive in 19 patients was negatively associated with their antibody titers (P= .005). The proportion of cultures positive increased after transplantation (P = .007). Sinusitis was associated with HHV-6 isolation in autologous recipients (P= .002). In allogeneic patients, active human cytomegalovirus infection was associated with HHV-6 isolation (P = .04). No association was observed between HHV-6 infection and GVHD, pneumonia, delay in engraftment, or marrow suppression. Of the 120 clinical events analyzed in 26 patients, HHV-6 was defined as a probable cause of 16 events in 9 patients based on the propinquity of HHV-6 activity and the clinical event plus the absence of other identified causes of the event.     

Plateletpheresis in the management of thrombocytosis

Acute thrombotic and hemorrhagic manifestations of thrombocytosis associated with myeloproliferative disorders may be life threatening. Conventional therapy with radioisotopes and/or cytotoxic drugs may require weeks for effective control of platelet counts. In five patients, plateletpheresis by discontinuous-flow (Haemonetics) or continuous-flow (Aminco Celltrifuge) centrifugation was used as a means of reducing platelet counts acutely. With each procedure, approximately 2-9 X 10(12) platelets were removed, resulting in decrements in platelet counts and relief of symptoms. Plateletpheresis is a useful and safe acute means of controlling platelet counts in myeloproliferative disorders.     

Status of the epidemiology of atrial fibrillation

Atrial fibrillation (AF), an increasingly common dysrhythmia, is responsible for substantial morbidity and mortality. Currently in the United States, approximately 2.3 million people are diagnosed with AF and, based on the census, this number may rise to 5.6 million by 2050. Risk factors for AF include advancing age and cardiovascular disease and its risk factors. The chief hazard of AF is embolic stroke, which is increased four- to fivefold, assuming great importance in advanced age when it becomes a dominant factor. AF is associated with about a doubling of mortality.     

Penetrance of the C28Y/C282Y genotype of the HFE gene

OBJECTIVE: Hereditary hemochromatosis is a common genetic disease caused by accumulation of iron in the body. Most cases are homozygous for the C282Y mutation in the HFE gene, but only a minority of homozygotes will ever suffer from clinical hemochromatosis. Estimates of the penetrance of the C282Y/C282Y genotype vary greatly. The purpose of this study was to estimate the penetrance using a stringent definition, i.e. liver cirrhosis. MATERIAL AND METHODS: The results from previous phenotypic population screening for hereditary hemochromatosis were combined with findings in hospital databases in order to estimate the number of C282Y homozygotes with and without liver cirrhosis in a Norwegian county. The penetrance of the C282Y/C282Y genotype was estimated as the fraction of C282Y homozygotes with liver cirrhosis. We also calculated the expected number of male C282Y homozygotes with liver cirrhosis using figures for age-specific accumulated risk. RESULTS: The prevalence of liver cirrhosis in male homozygotes is between 3.4% and 5.0%. This figure is compatible with an accumulated risk of liver cirrhosis that increases from 0.2% at 35 years to about 10% at 65 years of age. In female homozygotes, the prevalence of liver cirrhosis is 0.3%. CONCLUSIONS: A small but significant number of Norwegian male C282Y homozygotes will contract liver cirrhosis if their hemochromatosis is not diagnosed and treated in time. The penetrance is much lower in women than in men.     

参三七皂甙Rg1对实验性血栓形成的影响及其机制探讨

用大鼠动静脉血栓形成模型，研究参三七皂甙Ｒｇ１抗血栓作用。结果表明，参三七皂甙Ｒｇ１可明显降低实验性血栓形成，对大鼠血浆纤溶系统亦有明显作用，可升高血浆中组织纤溶酶原激活物（ｔＰＡ）活性和活性型ｔＰＡ百分比，降低组织纤溶酶原激活物抑制剂（ＰＡＩ）活性。同时利用培养大鼠血管内皮细胞实验，发现Ｒｇ１可以剂量依赖性提高血管内皮细胞一氧化氮（ＮＯ）释放。提示Ｒｇ１抗血栓作用与增强纤溶系统活性，促进血管内皮ＮＯ释放有关