臀部坐骨神经损伤及修复

目的　报告 190例臀部坐骨神经损伤的临床资料并探讨其处理方法。方法　药物注射伤 16 4例(占 86 .32 % ) ,锐器伤 14例 ,骨盆骨折、髋关节脱位合并伤 11例 ,臀部挫伤 1例。非手术治疗 15例 ,手术 175例。术中见损伤平面在臀大肌段 146例 ,梨状肌段 2 6例 ,盆腔段 3例。采用神经松解术 16 0例 ,神经外膜对端吻合 12例 ,神经移植术 2例 ,神经探查未修复神经 1例 ;2 3例做了后期足踝部功能重建术。结果　 15 1例获得 6个月～ 2 1年随访 (平均 8.5年 ) ,神经恢复的优良率为 5 6 .95 % ,后期功能重建的优良率为 78.2 6 %。结论　臀部坐骨神经损伤是周围神经损伤中最难处理和疗效最差的部位之一。其各段损伤与局部解剖关系密切。治疗应持积极态度 ,药物注射伤应争取尽早行神经松解术 ;神经断裂伤行外膜对端吻合术 ;骨盆骨折、髋脱位引起者 ,早期复位减压 ,后期须探查修复神经。晚期足踝部功能重建可改善肢体功能。     

Gestational trophoblastic neoplasia: diagnosis with Doppler US

The sonographic appearance of gestational trophoblastic neoplasia is nonspecific and also seen in complete or partial hydatidiform mole, hydropic degeneration, degenerating fibroids, or ovarian dysgerminomas. Correlation with the serum human chorionic gonadotropin (hCG) level may be helpful since levels exceeding 100,000 IU/L are strongly suggestive of gestational trophoblastic neoplasia. However, low hCG levels may also be found in the presence of this disease. The authors studied six patients who were suspected of having gestational trophoblastic neoplasia. Three of the six proved to have incomplete abortions or molar degeneration. Doppler ultrasound (US) was used to record the signal in the uterine arteries of these patients. The signals were compared with those of three nongravid volunteers and three patients in the first trimester of pregnancy. Analysis of the signals in the uterine artery showed higher systolic and diastolic Doppler shifts in gestational trophoblastic neoplasia when compared with postabortal, gravid, and nongravid signals. These preliminary results indicate that Doppler US has the potential to be clinically useful in the diagnosis of gestational trophoblastic neoplasia.     

Can local administration of tranexamic acid during total knee arthroplasty reduce blood loss and transfusion requirements in the absence of surgical drains?

Blood transfusions are frequently required following total knee arthroplasty. Tranexamic acid (TXA) inhibits fibrinolysis and has been shown to reduce blood loss and transfusion requirements when delivered intravenously. Topical and intra-articular applications directly target bleeding sites whilst limiting systemic uptake and theoretically reduce the risk of thromboembolic complications. However, in the absence of surgical drains, which increase post-operative blood loss, the efficacy of these techniques for reducing transfusion requirements is unclear. Our aim was to determine if locally administered tranexamic acid during total knee arthroplasty could reduce both blood loss and transfusion requirements in the absence of surgical drains. A retrospective review of 248 patients treated with primary unilateral cemented total knee arthroplasty was performed. Patients treated after January 2011 received topical and intra-articular tranexamic acid at the end of the procedure (n = 136). A second group of consecutive patients treated before this period acted as historical controls (n = 112). Patient groups were equivalent in terms of age, gender and ASA grade. There was a significant reduction in mean blood loss of 246 ml between the groups (p < 0.01). In addition, the requirement for post-operative allogenic blood transfusion was significantly reduced from 15.5 to 5.4 % after introduction of the tranexamic acid regimen (p = 0.02). This is the largest patient cohort reviewed to measure the efficacy of locally administered tranexamic acid during total knee arthroplasty and demonstrates that this is an effective technique for reducing both blood loss and transfusion requirements in the absence of surgical drains.     

11β-Hydroxysteroid dehydrogenase type 1-driven cortisone reactivation regulates plasminogen activator inhibitor type 1 in adipose tissue of obese women

BACKGROUND: Plasminogen activator inhibitor type 1 (PAI-1) is the main inhibitor of the fibrinolytic system and contributes to an increased risk of atherothrombosis in insulin-resistant obese patients. In adipose tissue, we have shown that PAI-1 is synthesized mainly in the visceral stromal compartment and is positively regulated by glucocorticoids. We have demonstrated that adipose tissue expression of 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD-1), an enzyme that catalyzes the conversion of inactive cortisone to active cortisol, is exaggerated in obese patients. OBJECTIVES: We hypothesized that increased action of 11beta-HSD-1 in adipose tissue of obese subjects may contribute to PAI-1 overproduction. PATIENTS AND METHODS: Using in situ hybridization, we studied the expression of the mRNAs coding for PAI-1 and 11beta-HSD-1 in the stromal compartment of visceral adipose tissue obtained from obese women. The regulation of PAI-1 secretion from in vitro incubated tissue explants was also investigated. RESULTS: Regression analysis showed a significant positive linear relationship between PAI-1 and 11beta-HSD-1 mRNAs expression. In vitro incubation of adipose tissue explants demonstrated that cortisone stimulated PAI-1 gene expression and secretion, and that these effects were inhibited by co-incubation with the 11beta-HSD inhibitor, glycyrrhetinic acid. CONCLUSIONS: Our data demonstrate that 11beta-HSD-1-driven cortisone reactivation regulates adipose PAI-1 synthesis and secretion. They suggest that the increased PAI-1 synthesis and secretion observed in obese patients can be also related, at least in part, to an increased local conversion of cortisone to cortisol. Therefore, local cortisol metabolism in adipose tissue may be involved in increasing the risk of cardiovascular disease in obese subjects.     

The C-terminal sequences of the gamma 57.5 chain of human fibrinogen constitute a plasmin sensitive epitope that is exposed in crosslinked fibrin

The gamma chain of human plasma fibrinogen is heterogeneous with three forms differing in length at the C-terminus. Alternative RNA splicing produces two gamma chain mRNAs encoding gamma 50 and gamma 57.5 polypeptides, while fibrinogen gamma 55 is produced by post- translational modification of the gamma 57.5 chain. The composition of purified variant gamma chain fibrinogens, which comprise 10% to 13% total plasma fibrinogen, is predominantly heterodimeric (A alpha, B beta, gamma 50/gamma 55 or A alpha, B beta, gamma 50/gamma 57.5), whereas the composition of purified fibrinogen with the major form of the gamma chain is homodimeric (A alpha, B beta, gamma 50/gamma 50). These gamma chain variations interrupt sequences that mediate platelet- fibrinogen interactions. Therefore, the structure and function of gamma 57.5 C-terminal sequences were investigated using synthetic peptides and a specific monoclonal antibody (MoAb), L2B. The L2B epitope was localized and included gamma 57.5 chain residues 409-412 (Arg-Pro-Glu- His), as determined by differential enzyme-linked immunosorbent assay (ELISA) reactivity with a His-412 deleted synthetic peptide and by Western blot analysis of plasmin cleaved fibrinogen gamma 57.5. L2B had no effect on adenosine diphosphate (ADP)-induced platelet aggregation supported by either fibrinogen gamma 50 or gamma 57.5. High concentrations (0.5 to 1 mmol/L) of synthetic peptide gamma 57.5 405- 416 only weakly inhibited ADP-induced platelet aggregation supported by either fibrinogen gamma 50 or gamma 57.5. Binding of fibrinogen gamma 50 (IC50 = 780 mumol/L) or gamma 57.5 (IC50 = 650 mumol/L) to ADP- stimulated platelets was weakly inhibited, and MoAb L2B failed to inhibit fibrinogen gamma 57.5 binding. Peptide gamma 57.5 408-416 failed to dissociate platelet-bound fibrinogens. These data indicate that the gamma 408-416 sequence of fibrinogen gamma 55 or gamma 57.5 alone is unlikely to bind to the platelet fibrinogen receptor, glycoprotein llb-llla (GPllb-llla), in support of platelet aggregation under physiologic conditions. The sequence recognized by L2B does not resemble known GPllb-llla binding site peptide sequences [Arg-Gly-Asp- Ser (RGDS) or gamma 50 400-411] as determined by competitive inhibition ELISA comparing these binding site synthetic peptides with gamma 57.5 408-416. This epitope is available for binding MoAb L2B in gamma 55 or gamma 57.5 chain dimers and binds to all gamma 57.5 408-416 epitopes equally in non-crosslinked and factor Xllla crosslinked fibrin clots.(ABSTRACT TRUNCATED AT 400 WORDS)     

The synthetic RGDS peptide inhibits the binding of fibrinogen lacking intact alpha chain carboxyterminal sequences to human blood platelets

The alpha chain 572-574 Arg-Gly-Asp sequence of fibrinogen appears to play only a minor role in platelet aggregation based on the ability of fibrinogen preparations lacking alpha chain carboxyterminal segments to support platelet aggregation, but synthetic Arg-Gly-Asp-Ser (RGDS) peptides are capable of inhibiting platelet aggregation and fibrinogen binding. The present study thus examined the ability of RGDS peptides to inhibit platelet interactions with a plasmic degradation product of fibrinogen (8D-50) that resembles an intermediate fragment X. Gel- filtered, human blood platelets suspended in 0.01 mol/L HEPES-buffered modified Tyrode's solution, pH 7.5, were stimulated with 20 mumol/L adenosine diphosphate and the binding of 125I-labeled 8D-50 or intact fibrinogen (0.01 to 0.6 mg/mL) assessed in the presence of 0 to 117 mumol/L RGDS. The data revealed that RGDS decreased the apparent affinity of 8D-50 and intact fibrinogen for platelets but did not affect the maximum number of binding sites. RGDS thus appears to be a competitive inhibitor not only of intact fibrinogen (Ki = 12 +/- 2 mumol/L) but also of 8D-50 (Ki = 15 +/- 3 mumol/L) (mean +/- SD, n = 3).     

Vascular calcification is not associated with increased ambulatory central aortic systolic pressure in prevalent dialysis patients

Vascular calcification (VC) is a novel vascular risk factor strongly associated with mortality in dialysis patients.1,2 Although various explanations exist for this association, one mechanism is through alterations in pulse-wave velocity (PWV). Vascular calcification is associated with increased aortic PWV,3 which in turn is associated with raised central aortic systolic pressure (CASP) and reduced coronary perfusion.4,5 As a result, brachial pressure may significantly under- or over-estimate central pressure.6Not surprisingly therefore, central blood pressure parameters have been shown to predict hard cardiovascular endpoints (including mortality) better than concomitant brachial measurements.7-10 Whether vascular calcification is directly linked to central pressures is, however, unknown since there are many determinants of aortic stiffening other than calcification. Furthermore, a primarily damaged and stiff aorta may be the target for secondary deposition of calcium.11CASP can be calculated using applanation tonometry-derived peripheral pulse waveforms and associated software.12 This avoids the obvious disadvantages of invasive central pressure determination. The major disadvantage of standard techniques, however, is the one-dimensional static measurement that is obtained, with no information on ambulatory values or nocturnal dipping status.Loss of normal nocturnal systolic blood pressure dipping is prevalent in chronic kidney disease (CKD) and likely contributes to cardiovascular disease.13 Dipping, which can only be assessed using ambulatory monitoring techniques, correlates better with left ventricular mass index (LVMI) in end-stage renal disease than office-based blood pressure measurement.14,15There have been calls for the routine use of ambulatory blood pressure monitoring (ABPM) in clinical studies of CKD13,16 and indeed, for investigations into the utility of ambulatory CASP in clinical practice.17,18 Combining both ambulatory and central pressure measurements is an attractive strategy, but until recently has not been technically possible.A non-invasive wrist watch-like device, BPro with A-Pulse CASP software (HealthStats, Singapore) was recently approved by the US Food and Drug Administration (FDA: K072593) for the measurement of CASP as well as ambulatory blood pressure. It is a small, wrist watch-like, cuffless monitor which obtains radial pressure waveforms by applanation tonometry. BPro has the ability to measure ambulatory CASP and although not yet commercially available, the manufacturer is able to convert data into ambulatory CASP using the same software.As part of a recently published study on vascular calcification,19 we sought to prospectively evaluate whether the presence of vascular calcification had any relationship with ambulatory CASP in our young CKD-5D cohort using the BPro® radial pulse-wave acquisition device. We also sought to determine the utility of inter-dialytic office brachial and central blood pressure measurements in predicting ambulatory parameters.     

探讨尿常规与血肌酐检查在诊断心源性脑梗死中的应用

目的：探讨尿常规检查在诊断心源性脑梗死疾病中应用价值,为临床提高此类患者诊断正确率提供可靠依据,保障患者生活质量与生命安全。方法指定同一名具有专业知识及丰富经验的临床检验人员对研究组心源性脑梗死患者与对照组非心源性脑梗死患者进行尿常规临床检验,检验内容包括尿液中白细胞计数、红细胞计数、尿比重、尿蛋白水平、血肌酐水平等。观察并记录两组患者尿常规检测结果,给予统计学分析,得出结论。结果研究组患者尿常规检测结果中白细胞计数（5．54±2．48）×10^9/L、红细胞计数（61．53±25．34）×10^12/L以及血肌酐水平（114．36±24．87）μmol/L均明显高于对照组非心源性脑梗死患者的（3．29±1．71）×10^9/L、（7．92±3．50）×10^12/L、（89．67±16．54）μmol/L,差异有统计学意义（P＜0．05）;研究组患者尿液中尿比重1．01±0．30以及24h尿蛋白水平（0．06±0．01）g/L与对照组患者的（1．01±0．23）、（0．05±0．01）g/L比较差异无统计学意义（P＞0．05）。结论应用尿常规检测可准确区分心源性脑梗死及非心源性脑梗死疾病,且尿常规检测具有取材方便,可快速获得结果,操作简单,价格低廉等优点,利于患者接受检验,值得临床推广应用。     

Linkage of polymorphic congenital cataract to the gamma-crystallin gene locus on human chromosome 2q33-35

Cataract is one of the major causes of blindness in humans. We describe here an autosomal dominant polymorphic congenital cataract (PCC) which is characterised by wide variations in phenotype of non-nuclear lens opacities, even among affected members of the same family. PCC families included a large, unique pedigree (254 members, 103 affected individuals), and genetic linkage was conducted using a variety of polymorphic markers. Evidence for linkage was found for chromosome 2q33- 35 with PCC mapping near D2S72 and TNP1. A tri-nucleotide microsatellite marker for gamma-crystallin B gene (CRYG1) was found to co-segregate with PCC and yielded a maximum lod score of 10.62 at (theta = 0). A multipoint analysis demonstrated that the most probable location of the PCC gene was within an 8 cM genetic interval containing the gamma-crystallin gene cluster. These data provide strong evidence of the existence of an autosomal dominant mutation for PCC in or near the gamma-crystallin gene cluster. This defect is characterised by complete penetrance but variable expression of the cataract phenotype. Our study also suggests that non-nuclear human cataracts might be caused by some abnormality in gamma-crystallin genes.