Knee injuries: high-resolution MR imaging

Recent technologic advances have made high-resolution magnetic resonance (MR) imaging of the knee a clinical reality. Ten healthy volunteers and 30 patients with suspected knee injuries were imaged using receive-only surface coils and two-dimensional multisection or three-dimensional selective acquisition techniques. Arthroscopic and/or surgical correlation was available in 15 patients. Tears of the cruciate ligament, medial collateral ligament, and meniscus are illustrated. Nonorthogonal views of the anterior cruciate ligament are useful for demonstrating both femoral and tibial attachments in the same section. The posterior cruciate ligament is usually well seen on sagittal views. T2-weighted images are helpful for demonstrating collateral ligament tears and meniscal tears when joint effusion is present. Thin sections (1-5 mm) are necessary to define many meniscal and cruciate tears. High-resolution, thin-section MR imaging can be used to diagnose soft-tissue injuries of the knee and has the potential to become a major imaging method in the evaluation of knee injuries.     

Effectiveness of a prospective physician self-audit transfusion- monitoring system

BACKGROUND: The purpose of this study was to search for a more effective transfusion-monitoring system than the existing system of retrospective peer review. STUDY DESIGN AND METHODS: This research used a study-control, preintervention and postintervention design, to evaluate the effectiveness of a prospective physician self-audit transfusion-monitoring system that functioned without the direct involvement of transfusion service physicians. This research also evaluated the effectiveness of issuing to physicians a memo with transfusion guidelines. Three process indicators were used to assess physician behavior at various stages of the blood-ordering process: 1) the number of crossmatches ordered per admission, 2) the transfusion-to- crossmatch ratio, and 3) the number of blood units returned to the laboratory after physician self-auditing. The study used two outcome indicators to reflect overall blood utilization: 1) the percentage of patients who received red cell transfusions and 2) the number of blood units transfused per recipient each month. RESULTS: The prospective physician self-audit system implemented at the study hospital did not reverse physician transfusion decisions, and the process of issuing to physicians a memo with transfusion guidelines at the control hospital failed to reduce blood usage. However, a transient reduction in blood utilization was observed at the study hospital. CONCLUSION: The reduction was hypothesized to be due to a Hawthorne effect, in which observed behavior is affected by the subject's awareness of the research study.     

建立自体骨碎末移植材料恢复骨缺损的实验模型

目的:建立恢复种植体周围骨缺损的自体骨碎末骨移植材料的实验模型。方法:实验于2005-08/2006-04在大连医科大学动物实验基地(辽宁省重点实验室)完成。①实验材料:健康杂交家犬5只,体质量15～20kg。Bio-Oss骨移植材料为引导骨/组织再生多孔骨无机材料,白色颗粒状,颗粒大小1.0～2.0mm。②实验方法:拔除家犬下颌第1,2,3前臼齿,3个月后行种植术。预备种植体窝,每只犬左右两侧各预备4个,共40个。在每个种植窝内,各植入种植体钛钉1枚,共40枚。用种植转孔时收集的自体骨碎末、Bio-Oss骨移植材料及两者1∶1混合骨碎末恢复种植体颊侧单壁人为骨缺损,以未植骨作空白对照。③实验评估:第9周时观察各组骨量的恢复情况、X线片观察牙槽骨高度、骨小梁致密度及骨整合情况,亚甲基蓝-碱性品红法观察组织学变化。结果:5只家犬钛钉均无脱落,均纳入结果分析。①一般情况:9周时,创口愈合均良好,钛钉稳定,总存留率为100%。骨缺损处已有不同程度恢复,与正常骨组织无明显差别。②9周时各组骨缺损量的测量结果:植入自体骨碎末、Bio-Oss骨移植材料、混合骨碎末及空白对照组的平均骨缺损量分别为1.8125、1.6975、1.5025、2.6375mm。植入混合骨碎末的平均骨缺损量最小,说明恢复最佳。③X线观察骨量的恢复情况:40颗钛钉外周均与骨组织紧密接触,愈合良好。不同组间未见明显骨质密度区别。④组织学观察骨量的恢复情况:低倍镜下见所有钛钉均被周围淡红色的致密骨组织紧密包绕,种植体与骨组织间无蓝色的软组织,产生了直接骨结合界面。结论:应用家犬建立自体骨碎末移植材料恢复种植体周围骨缺损的实验模型效果理想。     

Comparative Trial of Norfloxacin and Macrocrystalline Nitrofurantoin (Macrodantin) in the Prophylaxis of Recurrent Urinary Tract Infection in Women

SUMMARY Eighty-eight women with a history of recurrent urinary tractinfection (at least four attacks in the preceding 12 months)were randomized to take either norfloxacin 200 mg at night (45patients) or macrocrystalline nitrofurantoin 100 mg at night(43 patients) for 12 months. A decrease in the number of symptomaticattacks while taking this prophylaxis was observed in 94 percent of the patients and this improvement was maintained duringthe 6 months following the end of prophylaxis in 69 per cent.The mean interval between symptomatic episodes while takingprophylaxis was 7.2-fold and 6.9-fold greater, respectively,than in the 12 months before starting prophylaxis. There wereonly nine breakthrough infections during 74 patient-years ofprophylaxis, four in patients taking norfloxacin (two enterococci,one Staphylococcus epidermidis, one Escherichia coli), and fivein those taking macrocrystalline nitrofurantoin (four E. coli,one Klebsiella pneumoniae). Adverse events caused four patientstaking norfloxacin (8 per cent) and seven taking macrocrystallinenitrofurantoin (14 per cent) to stop prophylaxis. Norfloxacinhad a marked suppressive effect on the coliform part of thefaecal flora, with no emergence of resistance. Thus, norfloxacinappears to be an excellent alternative agent to macrocrystallinenitrofurantoin for the prevention of recurrent urinary infections.     

Prenatal identification of potential donors for umbilical cord blood transplantation for Fanconi anemia

Reported here are studies of Fanconi anemia fetal cells that led to the first use of umbilical cord blood for hematopoietic reconstitution in a clinical trial. Prenatal diagnosis and HLA typing were performed in fetuses at risk for Fanconi anemia (FA) to identify, prior to birth, those that were unaffected with the syndrome and were HLA-identical to affected siblings. Umbilical cord blood was harvested at the delivery of these infants; assays of progenitor cells indicated the presence of colony-forming units-granulocyte-macrophage (CFU-GM) in numbers similar to those of bone marrow CFU-GM that are associated with successful engraftment in HLA-matched allogeneic bone marrow transplantation. The possibility that umbilical cord blood from a single individual can be used as an alternative to bone marrow for hematopoietic reconstitution has now been demonstrated by the successful engraftment of two patients with FA. Progenitor cell assays of umbilical cord blood collected at the birth of a child affected with FA, who had been misdiagnosed on the basis of chorionic villus sampling (CVS) studies, indicated a profound deficiency in colony formation, consistent with previously reported abnormalities in the growth of FA cells in vitro. These results suggest that the hematopoietic disorder in FA is related to an underlying problem with cell proliferation.     

Three patients with structurally abnormal X chromosomes, each with Xq13 breakpoints and a history of idiopathic acquired sideroblastic anemia

Structural abnormalities of the X chromosome are rarely found in neoplastic disorders. We describe three patients with a history of idiopathic acquired sideroblastic anemia (IASA); each one had an abnormal clone of cells in the bone marrow, characterized by a structurally abnormal X chromosome. In two of these patients, the predominant karyotype was 47,X,2idic(X)(q13); in the other patient, it was 46,X,t(X;11)(q13;p15). Inasmuch as all three of these cases involved chromosome band Xq13, as did two previously published cases, we suggest that band Xq13 may be more prone to structural rearrangement than other X chromosome bands in hematologic disorders. The common Xq13 chromosome breakpoint and clinical presentation (IASA) among these three patients and the occurrence of an X-linked type of sideroblastic anemia may suggest that an association exists between X chromosome abnormalities and IASA. Perhaps alteration of a gene or chromosome structure in or near band Xq13 predisposes to development of IASA. The fact that two of these patients had preleukemia and the third had overt acute leukemia may imply that patients with IASA and X chromosome abnormalities have a poor prognosis. Cases of IASA without associated X chromosome abnormalities are known; thus, if an association between IASA and an abnormal X chromosome does exist, most likely it involves only some patients with IASA.     

Correlation between patterns of horizontal connectivity and the extend of short-term representational plasticity in rat motor cortex

Plasticity of representational maps in adult cerebral cortex has been documented in both sensory and motor cortex, but the anatomical basis for cortical plasticity remains poorly understood. To investigate horizontal connectivity in primary motor cortex (M1) as a putative anatomical substrate for short-term, functional plasticity of adult motor cortical representations, a combination of electrical stimulation and biocytin labeling was used to examine pre-existing patterns of intrinsic connections in adult rat M1 in relationship to the pattern of reorganization of the motor movement may induced by transection of the contralateral facial nerve. Two hours after nerve cut, small, circumscribed regions of the forelimb representation expanded medially into territory previously devoted to the vibrissae representation. Outside of this novel, expanded forelimb region, no forelimb movement could be evoked from the former vibrissae representation at any time over the period of hours tested, thus representing silent cortex. Injections placed into vibrissae cortex representing the newly expanded forelimb representation gave rise to labeled axons and dense terminal fiber labeling which crossed the forelimb/vibrissae border and extended up to 1.2 mm within the low-threshold forelimb representation. In contrast, injections placed into silent vibrissae cortex gave rise to labeled axons and terminal boutons which remained mostly restricted to the original vibrissae representation, with only sparse projections that crossed into the low-threshold forelimb representation. Thus, these results suggest that the extent of short-term, functional reorganization of M1 induced within the first several hours following peripheral nerve cut is mediated, and constrained, by an anatomical framework of pre-existing, horizontal projections which traverse representation borders.      

荧光原位杂交法快速鉴定血培养阳性葡萄球菌的临床应用

目的快速鉴定血培养中的金黄色葡萄球菌和凝固酶阴性葡萄球菌(CoNS),结合临床快速判定是否为污染菌。方法采用荧光原位杂交法鉴定血培养中的金黄色葡萄球菌和CoNS,杂交结果若为CoNS,根据临床资料进行判断,并与文献推荐的污染判断法进行结果比较。结果探针的特异性经由标准菌株和临床分离菌株证实。金黄色葡萄球菌探针的特异性和敏感性均为100%,GoNS探针的特异性和敏感性分别为100%和95.5%。179株CoNS中117株判断为污染菌,污染率为68%,与文献推荐的污染判断方法一致。结论荧光原位杂交法适用于血培养中的金黄色葡萄球菌和CoNS的快速鉴定,以排除CoNS污染。     

融合蛋白 NrCAM-Fc的重组体的构建

目的：构建神经原相关的细胞粘附分子（NrCAM）和免疫球蛋白Fc片段融合基因的重组质粒并通过Baculovirus载体转染到昆虫细胞。方法：利用RT－PCR方法从神经母细胞瘤细胞系SK－N－SN获得NrCAM的信号肽区和跨膜区片段并直接克隆到pGEMT载体，经多次酶切、连接、转化、筛选获得NrCAM-Fc的重组副合基因，测序后将此基因通过Baculovirus载体转染至昆虫细胞。结果：多种酶切和测序结果表明NrCAM-Fc的序列与原序列符合率达98％以上，NrCAM与Fc连接处序列保证了Fc的读码框架（ORF）。结论：Baculovirus载体转染效率高，检测方法简便易行。