周围神经源性良性肿瘤的超声特性

目的通过分析周围神经源性良性肿瘤的超声特性,评价超声在周围神经源性良性肿瘤中的诊断作用。方法采用回顾性调查方法收集2000—2011年我院收治的有完整临床资料的良性周围神经肿瘤65例患者的术前超声检查、手术图片及病理检查结果,其中58例肿瘤患者同时包含彩色多普勒超声检查结果,由2位有丰富临床经验的超声影像医师对患者的术前超声图像进行回顾分析,评估肿瘤超声特性包括肿瘤的形状、大小、边界、包膜、内部回声特性、后方回声情况与周围神经的关系以及血流情况。结果本组65例良性周围神经源性肿瘤70处病变的超声检查结果显示42处病变(60%)为内部回声均匀的实质性低回声结构;28处病变(40%)为回声不均的低回声结构,其中18处(26%)病变为低回声结构内部可见高回声区,10处(14%)病变为低回声结构内部可见液性暗区;36处病变与知名周围神经相连。58例肿瘤彩色多普勒超声检查显示24例肿瘤(41%)有丰富血流信号,22例肿瘤(38%)有少量血流信号,12例(21%)肿瘤无血流信号。65例患者70处病变均行手术切除,术中见54处病变来源于知名的周围神经,16处病变位于肌肉内,无知名神经纤维连结。超声检查显示病变与神经相连的阳性率为67%(36/54)。65例肿瘤手术切除后病理检查结果显示,62例肿瘤为神经鞘膜瘤,2例为神经纤维瘤,1例为神经纤维瘤病。结论超声检查能提供良性神经源性肿瘤较详细的形态、内部结构、边界、包膜以及肿瘤与周围组织的关系的信息,还能显示肿瘤与周围神经的联系以及血流情况等,检查方便易行,检查费用低廉,患者易于接受。     

Evaluation of drugs for elimination of leukemic cells from the bone marrow of patients with acute leukemia

Relatively nonmyelotoxic drugs and drug combinations were investigated for their ability to eliminate malignant cells from human bone marrow. In vitro 90% inhibitory concentration (IC90) doses were established on granulocyte macrophage colony-forming units (GM-CFU) in culture of bone marrow by using the GM-CFU assay for the following drugs: 4- hydroperoxycyclophosphamide (4-HC), Adriamycin, L-asparaginase, bleomycin, hydrocortisone, VP-16, spirogermanium, Taxol, and vincristine. The leukemic cell kill efficiency of these drugs at IC90 doses was compared with that of 4-HC on acute lymphoid leukemia (ALL) cell lines by using the limiting-dilution assay. Under these conditions, no single drug was superior to 4-HC. To increase the in vitro effect in leukemic cell kill, combinations of vincristine with hydrocortisone, Adriamycin, VP-16, and 4-HC were investigated. Vincristine at 1 to 5 micrograms/mL increased the marrow cytotoxicity of hydrocortisone, Adriamycin, and VP-16, but it was protective (subadditive) with 4-HC. Vincristine and 4-HC in combination was additive to supraadditive on ALL cell lines, increased the leukemic cell kill by one to two logs above 4-HC alone at IC90 doses (P less than .05), and was not affected by the addition of excess marrow cells. The recommended doses for chemopurging in clinical studies are vincristine, 1 to 5 micrograms/mL, plus 4-HC, 5 micrograms/mL.     

Should we treat all primary prevention patients with statins?

3-Hydroxy-3-methylglutary coenzyme A (HMG-CoA) reductase inhibitors have been shown to reduce cardiac events in different high-risk and medium-risk patient groups. Although there are other medications to lower cholesterol, evidence that these agents will provide protection from initial cardiac events is limited or does not exist. Also, although many physicians advocate combining second agents with statins to improve certain lipid fractions, evidence of improved reduction of initial cardiac events from these combinations is also lacking. Therefore, aggressive use of HMG-CoA reductase inhibitors remains the proven treatment to treat lipid abnormalities in primary patients.     

Surface-Bound Proteins with Preserved Functionality

Biocompatibility of materials strongly depends on their surface properties. Therefore, surface derivatization in a controllable manner provides means for achieving interfaces essential for a broad range of chemical, biological, and medical applications. Bioactive interfaces, while manifesting the activity for which they are designed, should suppress all nonspecific interaction between the supporting substrates and the surrounding media. This article describes a procedure for chemical derivatization of glass and silicon surfaces with polyethylene glycol (PEG) layers covalently functionalized with proteins. While the proteins introduce the functionality to the surfaces, the PEGs provide resistance against nonspecific interactions. For formation of aldehyde-functionalized surfaces, we coated the substrates with acetals (i.e., protected aldehydes). To avoid deterioration of the surfaces, we did not use strong mineral acids for the deprotection of the aldehydes. Instead, we used a relatively weak Lewis acid for conversion of the acetals into aldehydes. Introduction of α,ω-bifunctional polymers into the PEG layers, bound to the aldehydes, allowed us to covalently attach green fluorescent protein and bovine carbonic anhydrase to the surfaces. Spectroscopic studies indicated that the surface-bound proteins preserve their functionalities. The surface concentrations of the proteins, however, did not manifest linear proportionality to the molar fractions of the bifunctional PEGs used for the coatings. This finding suggests that surface-loading ratios cannot be directly predicted from the compositions of the solutions of competing reagents used for chemical derivatization.