Agenesis of the corpus callosum: magnetic resonance imaging

Three patients who had complete agenesis and two patients who had partial agenesis of the corpus callosum (ACC) underwent magnetic resonance (MR) imaging. In addition to excellent visualization of the indirect signs of ACC, direct vivid display (short T1) of the corpus callosum on sagittal images allowed better evaluation of subtle abnormalities than has been possible with other modalities. Associated abnormalities were also well-displayed. MR is the initial procedure of choice in evaluation of the corpus callosum.     

Establishment and characterization of an Epstein-Barr virus transformed cell line with strong phagocytic activity

An immunoglobulin M (IgM)-positive cell line, Ms 28, apparently spontaneously transformed by Epstein-Barr virus (EBV) was established from peripheral blood cells of a patient with immature myeloblastic leukemia. It has been characterized according to phenotype, cytochemistry, and membrane antigen pattern. The cell line expresses lymphoid markers like CD 19, CD 22, and CD 30 and synthesizes and secretes IgM. Monocyte markers CD 11c, CD 14, and CD 15 are absent. Neither interleukin-1 (IL-1), nor tumor necrosis factor (TNF-alpha) are produced. But Ms 28 cells show strong phagocytic activity and engulf Latex particles and sheep RBCs (SRBCs) that need not to be opsonized. The phagocytic activity can be inhibited by chloroquine. Both phagocytosis and EBV nuclear-antigen (EBNA) expression can be observed in one and the same cell. Ms 28 cells might be useful to study immunologic activities like antigen processing and presentation.     

Therapie der Stuhlinkontinenz bei älteren Patienten: Untersuchung zur Wirksamkeit eines Biofeedback-Heimtrainingsprogramms

The increased prevalence of urinary and fecal incontinence is one of the most important factors in the loss of independence and mobility in the elderly population. It is also one of the major reasons for elderly people to give up their household and move into a nursing home. Anorectal biofeedback therapy is a very effective treatment for fecal incontinence. However, due to the increased immobility of elderly people, ambulatory biofeedback training programs which require the participants to leave their homes and travel to the next available outpatient clinic on a regular basis, especially when depending on public transportation, may prove particularly difficult for elderly, incontinent subjects. Supervised home biofeedback training programs may offer an alternative for those patients, who are motivated enough and not mentally impaired. Two different age groups of women (between 49 and 63; and between 65 and 78 years old) suffering from fecal incontinence due to external anal sphincter impairment, received a supervised home biofeedback program, after extensive anorectal diagnostics including manometry. The program focused on improving voluntary sphincter contraction. After an average of 9 months, anorectal manometry was repeated, and anal resting and squeeze pressure as well as minimal rectal perception threshold were determined. There was no effect on anal resting pressure and rectal perception. However, anal maximum squeeze pressure as well as squeeze pressure over 10 s was substantially increased with no difference between the age groups. CONCLUSION: Supervised home biofeedback for sphincter insufficiency was effective in improving the voluntary contraction of the anorectum in both age groups. Therefore, biofeedback home training programs may offer an alternative to ambulatory programs for those individuals, who are not mobile enough to regularly attend an outpatient clinic.     

Likelihood ratios in the diagnosis of renal artery stenosis by magnetic resonance angiography compared with renal angiography

BACKGROUND: Renal angiography (RA) is considered to be the gold standard for the diagnosis of renal artery stenosis (RAS). However, it is invasive and potentially harmful; hence there is a need for an optimal noninvasive test. Magnetic resonance angiography (MRA) is currently accepted as the optimal noninvasive test by many. However, its major drawback is its inability to grade quantitatively the degree of stenosis. In this study, likelihood ratios (LR) were used to compare the diagnostic accuracy of MRA with that of RA. METHODS: To test the hypothesis that semiquantitatively graded MRA would correlate with RA, a retrospective analysis was performed to determine the LR of MRA to diagnose RAS compared with RA. It was believed that LR > or = 10.0 or < or =0.1 might generate conclusive changes from pretest to post-test probabilities. In this study a total of 94 renal arteries from 48 patients were analyzed for RAS by MRA and RA. Stenoses were graded by MRA as mild (<50%), moderate (50% to 75%), or severe (>75%); and by RA as <75% or > or =75% stenosis. RESULTS: The LR was 0.13 (95% CI = 0.09 to 0.19) for mild stenosis, 0.11 (95% CI = 0.08 to 0.15) for moderate stenosis, and 2.2 (95% CI = 1.9 to 3.1) for severe stenosis by MRA. CONCLUSIONS: Nonsevere stenosis can be sufficiently diagnosed by MRA and may not warrant RA. However, it may be insufficiently precise to establish severe RAS based on LR results. Therefore, for severe RAS by MRA, the decision to obtain RA can be made with the help of post-test probability, which is determined using pretest probability and LR.     

无牙颌颞下颌关节紊乱病患者总义齿修复前后咬合垂直距离改变与髁状突在关节凹内位置的关系

目的:观察咬合垂直距离改变对无牙颌颞下颌关节紊乱病患者两侧颞颌关节髁状突位置的影响。方法:于1994-01/1997-12选择本院口腔修复门诊收治的无牙颌患者中符合颞下颌关节紊乱病诊断标准,同时垂直距离减低的患者48例。实验方案经医院伦理委员会审批,患者均知情同意。将48例无牙颌颞下颌关节紊乱病患者根据垂直距离减低程度的不同分为3组:减低1.8～6.0mm组18例,减低6.1～10.0mm组20例,减低10.1￣14.0mm组10例。通过重新制作一副全口义齿的方法治疗,咬合垂直距离恢复在合适的范围内,3组全口义齿的咬合垂直距离恢复前分别平均为63.4,60.6,54.2mm,恢复后咬合垂直距离分别平均为67.8,68.4,66.4mm,平均抬高4.4,7.8,12.2mm。通过拍摄正中颌位时颞下颌关节薛氏位X射线片测量各组前、后、上关节间隙。结果:垂直距离恢复前,减低1.8～6.0mm组关节后间隙,减低6.1～10.0mm组关节前、后间隙、减低10.1￣14.0mm组关节上、后间隙左右侧相比较,差异有显著性意义(P<0.05)。垂直距离恢复后,3组关节间隙左右侧差异无显著性意义。结论:无牙颌咬合垂直距离减低后可以导致两侧髁状突位置发生不对称改变。     

三种移植物关节镜下重建膝关节前交叉韧带效果比较：2年随访

目的:采用自体骨-髌韧带、自体双股半腱肌腱半膜肌及同种异体跟腱移植重建膝关节前交叉韧带,比较不同移植物的临床疗效。方法:选择1998-06/2003-02中山大学附属第三医院骨科单纯前交叉韧带损伤后行关节镜下重建手术病例96例,患者均签署知情同意书。根据不同移植物分为3组:①自体骨-髌韧带组38例,应用自体中1/3骨-髌韧带-骨移植物。②自体双股半腱肌腱股薄肌腱组22例,应用自体双股半腱肌腱股薄肌腱。③同种异体跟腱组36例,应用同种异体跟腱。术后定期随访,对膝关节活动度、肌力恢复程度、Werner髌股痛评分(最差为0分,最高为55分)、Lysholm评分(0～100分,分数越高膝关节功能恢复越好)、国际膝关节文献委员会评分(按病情严重程度分类分为正常、接近正常、异常、严重异常4个等级)等进行对比观察。结果:①96例患者随访2年,无脱落。②全部患者无感染,未发生髌骨骨折。也未发现关节内粘连、下肢深静脉血栓形成和血管神经损伤等并发症。③膝关节活动度、肌力恢复情况、髌股痛评分:随访结束时3组差异均无显著性意义(P>0.05)。④Lysholm膝关节评分:随访结束时自体骨-髌韧带组由术前(68.2±6.3)分提高至(88.6±6.8)分,自体双股半腱肌腱股薄肌腱组由术前(66.5±6.5)分提高至(86.4±6.6)分,同种异体跟腱组由术前(68.2±6.3)分提高至(86.3±6.2)分,随访结束时各组评分均显著高于术前(P<0.05),3组比较差异无显著性意义(P>0.05)。⑤国际膝关节文献委员会评分(术后活动水平正常或接近正常):随访结束时自体骨-髌韧带组为87%,自体双股半腱肌腱股薄肌腱组为86%,同种异体跟腱组为89%,各组移植术后膝关节功能均有所改善,3组间差异无显著性意义(P>0.05)。结论:关节镜下采用自体骨-髌韧带、自体双股半腱肌腱股薄肌腱和同种异体跟腱移植重建前交叉韧带,均能明显改善膝关节运动功能,3种移植方法的临床疗效无明显差异,提示重建前交叉韧带的术后疗效与移植物种类的相关性不明显。     

构建Loa22基因去信号肽片段原核重组表达载体

目的：构建赖型钩端螺旋体OmpA膜蛋白Loa22基因去信号肽片段的原核表达载体，并对其进行克隆表达。方法：实验于2004—12／2005—12在四川大学华西医学中心感染免疫研究室完成。以赖型钩端螺旋体017株基因组DNA为模板，PCR扩增Loa22基因去信号肽片段，亚克隆至原核表达载体pGEX-4T-1，经双酶切、PCR鉴定，筛选出阳性重组质粒克隆。经DNA测序正确后，转化大肠杆菌，利用IPTG进行诱导表达，通过SDS—PAGE鉴定表达产物。结果：PCR获得长516bp的片段。Loa22基因去信号肽片段与pGEX-4T-1的重组质粒构建成功。重组质粒经IPTG诱导后能在大肠杆菌中表达Mr45000的融合蛋白。结论：制备了Loa22基因去信号肽片段原核重组表达载体，为钩体新型疫苗的研究奠定基础。     

Ubiquitination of inducible nitric oxide synthase is required for its degradation

Inducible nitric oxide synthase (iNOS) is responsible for nitric oxide (NO) synthesis from l-arginine in response to inflammatory mediators. We have previously shown that iNOS is degraded through the 26S proteasome. Targeting of proteins for proteasomal degradation may or may not require their covalent linkage to multiubiquitin chains (ubiquitination). In addition, ubiquitination of a protein can serve functions other than signaling proteolysis. In this context, it is not known whether iNOS is subject to ubiquitination or whether ubiquitination is required for its degradation. In this study, we show that iNOS, expressed in HEK293 cells or induced in primary bronchial epithelial cells, A549 cells, or murine macrophages, is subject to ubiquitination. To investigate whether iNOS ubiquitination is required for its degradation, HEK293T cells were cotransfected with plasmids containing cDNAs of human iNOS and of the dominant negative ubiquitin mutant K48R. Disruption of ubiquitination by K48R ubiquitin resulted in inhibition of iNOS degradation. ts20 is a mutant cell line that contains a thermolabile ubiquitin-activating enzyme (E1) that is inactivated at elevated temperature, preventing ubiquitination. Incubation of ts20 cells, stably expressing human iNOS, at the nonpermissive temperature (40 degrees C) resulted in inhibition of iNOS degradation and marked accumulation of iNOS. These studies indicate that iNOS is subject to ubiquitination and that ubiquitination is required for its degradation.     

Increased level of tumor necrosis factor-�� in patients with antiphospholipid syndrome: marker not only of inflammation but also of the prothrombotic state

Connections between inflammation and thrombosis are intriguing, especially in a condition such as an antiphospholipid syndrome (APS), a disease characterized by immune-mediated thrombosis. Tumor necrosis factor alpha (TNF-α) is a cytokine which shares proinflammatory and prothrombotic actions, while a soluble form of interlukin-2 receptor (sIL-2R) is considered a typical marker of (auto)immune inflammation with not known direct links to thrombosis. The differences in the pathogenesis of APS as compared to other autoimmune diseases might be connected with different serum levels of both mediators. To answer this question, we studied 147 patients with systemic lupus erythematosus (SLE), 21 with SLE-like syndrome (SLE-LS), 20 with isolated APS (primary antiphospholipid syndrome, PAPS), and 32 healthy controls. Thirty-six patients from the SLE group fulfilled the updated APS criteria (secondary APS, SAPS). In comparison to healthy subjects, TNF-α concentration was increased in all patients, while sIL-2R rose significantly in the SLE group only. APS (both SAPS and PAPS) was characterized by the highest levels of TNF-α. Moreover, patients with lupus anticoagulant or elevated levels of IgG anticardiolipin or IgG anti-β₂-glycoprotein I antibodies had higher TNF-α levels than patients without the presence of any type of antiphospholipid antibodies (aPL). In conclusion, the presence of aPL is associated with higher TNF-α level, whereas increased level of sIL-2R is rather connected with definite SLE where inflammatory processes prevail. It might be hypothesized that TNF-α plays a major role in pathogenesis of APS thrombotic phenomena.