Quantification of blood flow with dynamic MR imaging and presaturation bolus tracking

A technique is described for rapid imaging of blood flow and dynamic measurement of its velocity. The method is a combination of bolus tracking and low-flip-angle gradient-echo cine angiography. This method provides precise determination of velocity with high temporal resolution in a single measurement. Unlike what occurs in phase imaging techniques, flow is displayed directly, eliminating potential errors that result from non-flow-related sources of phase shifts. Manipulation of raw data sets is avoided. Results obtained from a flow phantom, healthy volunteers, and a patient with an aortic aneurysm demonstrate the capability of the technique to track flow at low and high velocities and to differentiate flowing blood from thrombus. Because of its conceptual simplicity, rapidity, and lack of susceptibility to extraneous phase shifts, this technique may prove ideal for in vivo flow measurement and evaluation of flow patterns.     

Tailored hormonal therapy in secretory adrenocortical cancer

Mitotane is often considered the front-line hormonal therapyof adrenocortical carcinoma (ACC). An illustrative case concerningthis issue and the rationale to ponder other alternatives isreported. A 69 year-old woman, diagnosed with ACC was admittedwith hypertensive crisis, supraventricular tachycardia, congestiveheart-failure, diarrhoea and rabdomyolisis. Two years earlier,she had undergone     

Ia antigen is a differentiation marker on human eosinophils

Evidence suggests that the "la-like" or antigen is a differentiation marker that is expressed on early human hematopoietic precursor cells, but is absent on their mature progeny. The eosinophil precursor cell (CFU-EO) is distinct from the granulocyte-monocyte colon-forming cell (CFU-C). We provide data that indicate that the ia antigen is expressed on the human eosinophil colony-forming cells and is absent on mature eosinophils. All CFU-EO were inhibited in the presence of rabbit la antiserum at a titer of 1:30. Cytotoxicity was complement-dependent. The metamyelocytic eosinophil and more mature eosinophil forms did not express the la antigen.     

Normalization of markers of coagulation activation with a purified protein C concentrate in adults with homozygous protein C deficiency

Homozygous or double heterozygous protein-C deficiency can present at birth with purpura fulminans or later in life with venous thrombosis. Two homozygous patients who had previously sustained thrombotic episodes were investigated at a time when they were asymptomatic and not receiving antithrombotic therapy. The plasma levels of protein-C antigen and activity in both individuals were approximately 20% of normal. We administered a highly purified plasma-derived protein C concentrate to these individuals and monitored levels of several markers of in vivo coagulation activation. Assays for protein-C activation (activated protein C and protein C activation peptide) showed a sustained increase from reduced baseline levels, whereas thrombin generation (as measured by prothrombin fragment F1 + 2) gradually decreased over about 24 hours into the normal range. These investigations provide direct evidence that protein C is converted to activated protein C in vivo, and that the protein-C anticoagulant pathway is a tonically active mechanism in the regulation of hemostatic system activation in humans.     

Clinical diagnosis of hypersensitivity pneumonitis

The diagnosis of hypersensitivity pneumonitis (HP) is difficult and often relies on histopathology. Our objective was to identify diagnostic criteria and to develop a clinical prediction rule for this disease. Consecutive patients presenting a condition for which HP was considered in the differential diagnosis underwent a program of simple standardized diagnostic procedures. High-resolution computed tomography scan and bronchoalveolar lavage (BAL) defined the presence or absence of HP. Patients underwent surgical lung biopsy when the computed tomography scan, BAL, and other diagnostic procedures failed to yield a diagnosis. A cohort of 400 patients (116 with HP, 284 control subjects) provided data for the rule derivation. Six significant predictors of HP were identified: (1) exposure to a known offending antigen, (2) positive precipitating antibodies to the offending antigen, (3) recurrent episodes of symptoms, (4) inspiratory crackles on physical examination, (5) symptoms occurring 4 to 8 hours after exposure, (6) and weight loss. The area under the receiver operating characteristic curve was 0.93 (95% confidence interval: 0.90-0.95). The rule retained its accuracy when validated in a separate cohort of 261 patients. The diagnosis of HP can often be made or rejected with confidence, especially in areas of high or low prevalence, respectively, without BAL or biopsy.     

整合蛋白α5亚基表达与肝癌恶性表型

目的探讨整合蛋白α５亚基与原发性肝癌的关系。方法应用免疫组化技术（ＡＢＣ法）和Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交检测整合蛋白α５亚基在原发性肝癌中的表达。结果发现在７９例癌与癌周组织α５阳性率分别为３２．９％和８１．０％，两者间差异有显著性（Ｐ＜０．０１）。直径≤５ｃｍ的肝癌α５阳性率高于直径＞１０ｃｍ的肝癌（５５．６％比１０．０％，Ｐ＜０．０１），分化较好的肝癌α５阳性率高于分化不良者（４０．６％比１６．０％，Ｐ＜０．０５），已发生明确肝内转移（包括肝内播散和门静脉癌栓形成）的肝癌α５阳性率低于未发生肝内转移者（２０．６％比４２．２％，Ｐ＜０．０５）。α５亚基表达与患者年龄、血清甲胎蛋白水平、乙型肝炎病毒感染、肝硬化有无等因素均无明显相关（Ｐ＞０．０５）。Ｎｏｒｔｈｅｒｎｂｌｏｔ杂交结果也同时显示，非侵袭性肝癌α５表达高于侵袭性肝癌。结论整合蛋白α５低表达与肝癌增大、分化程度低、侵袭转移发生等恶性表型相关，可能对这些恶性表型起负性调节作用。