急性缺血性卒中影像学检查的建议——美国心脏协会的科学声明（上）

卒中是一种常见、严重的疾病,仅美国每年的新发病例就高达795000例,并已成为全世界人类死亡和残疾的主要病因。10年前,重组型组织纤溶酶原激活剂（recombinant tissue plasminogen activator,rt—PA）被批准用于治疗急性缺血性卒中。rt—PA应用指南建议,应在卒中发病后3h内静脉给予rt—PA,给药前应行头部CT检查,排除颅内出血。     

Update Experience of Surgery for Acute Limb Ischaemia in a District General Hospital – Are We Getting Any Better?

INTRODUCTION

The aims of this study were to audit results of a 10-year experience of surgery for acute limb ischaemia (ALI) in terms of limb salvage and mortality rates, and to compare results with a historical published series from our unit.

PATIENTS AND METHODS

All emergency operations performed during the period 1993–2003 were identified from theatre registers and patient notes reviewed to determine indications for, and outcome of, surgery. Data were compared to a similar cohort who underwent surgery from 1980 to 1990.

RESULTS

There was a 33% increase in workload from 87 to 116 patients between the two time periods. The number of patients with idiopathic ALI reduced (24% versus 4%; P < 0.05), and there were fewer smokers (71% versus 39%; P < 0.05) and a greater number of claudicants (17% versus 35%; P < 0.05) in those treated from 1993–2003. Latterly, more patients underwent pre-operative heparinisation (33% versus 80%; P < 0.05), received prophylactic antibiotics (14% versus 63%; P < 0.05), and had anaesthetic presence in theatre (46% versus 88%; P < 0.05). There was also a reduction in local anaesthetic procedures (80% versus 41%; P < 0.05). Despite increased pre-operative (15% versus 47%; P < 0.05) and on-table imaging (0% versus 16%; P < 0.05) technical success did not improve. Whilst complication rates were identical at 62%, there were fewer cardiovascular complications in the recent cohort. The 30-day mortality rate for embolectomy fell from 45% to 33%. Multivariate analysis revealed age > 70 years, prolonged symptom duration, ASA score ≥ III, lack of prophylactic antibiotics, absence of an anaesthetist, and operations performed under local anaesthetic to be associated with increased risk of mortality. Factors adversely affecting limb salvage included prolonged duration from symptom onset to operation, and a history of claudication or smoking.

CONCLUSIONS

Despite improvements in pre- and peri-operative management, arterial embolectomy/thrombectomy remains a procedure with a high morbidity and mortality. Further attempts to improve outcome must be directed at early diagnosis and referral as delay from symptom onset to surgery is a major determinant of outcome.     

Choosing event‐driven and daily HIV pre‐exposure prophylaxis – data from two European PrEP demonstration projects among men who have sex with men

IntroductionDaily and event‐driven PrEP are both efficacious in reducing the risk for HIV infection. However, the practice of event‐driven PrEP (edPrEP) is less well studied, in particular when provided as an alternative to daily PrEP. We studied regimen preferences and switches, and sexually transmitted infection (STI) incidence.MethodsWe analysed pooled data from two prospective cohort studies among MSM: Be‐PrEP‐ared, Belgium and AMPrEP, the Netherlands. In both projects, participants could choose between daily and edPrEP at three‐monthly study visits, when they were also screened for sexually transmitted infections including hepatitis C (HCV). We assessed the proportion choosing each regimen, and the determinants of choosing edPrEP at baseline. Additionally, we compared the incidence rates (IRs) of HCV, syphilis and chlamydia or gonorrhoea between regimens using Poisson regression. The study period was from 3 August 2015 until 24 September 2018.Results and discussionWe included 571 MSM, of whom 148 (25.9%) chose edPrEP at baseline. 31.7% of participants switched regimen at least once. After 28 months, 23.5% used edPrEP. Older participants (adjusted odds ratio (aOR) = 1.38 per 10 years, 95% confidence interval (CI) = 1.15 to 1.64) and those unemployed (aOR = 1.68, 95% CI = 1.03 to 1.75) were more likely to initially choose edPrEP. IR of HCV and syphilis did not differ between regimens, but the IR of chlamydia/gonorrhoea was higher among daily users (adjusted incidence rate ratio = 1.61, 95% CI = 1.35 to 1.94).ConclusionsA quarter of participants chose edPrEP at baseline and at 28 months this proportion was similar. Although the IR of HCV and syphilis were similar in the two regimens, the lower incidence of chlamydia and gonorrhoea among edPrEP users may suggest that less frequent STI testing of this group could be considered.     

A crucial role for TNF-α in mediating neutrophil influx induced by endogenously generated or exogenous chemokines,KC/CXCL1 and LIX/CXCL5

Background and purpose:

Chemokines orchestrate neutrophil recruitment to inflammatory foci. In the present study, we evaluated the participation of three chemokines, KC/CXCL1, MIP-2/CXCL2 and LIX/CXCL5, which are ligands for chemokine receptor 2 (CXCR2), in mediating neutrophil recruitment in immune inflammation induced by antigen in immunized mice.

Experimental approach:

Neutrophil recruitment was assessed in immunized mice challenged with methylated bovine serum albumin, KC/CXCL1, LIX/CXCL5 or tumour necrosis factor (TNF)-α. Cytokine and chemokine levels were determined in peritoneal exudates and in supernatants of macrophages and mast cells by elisa. CXCR2 and intercellular adhesion molecule 1 (ICAM-1) expression was determined using immunohistochemistry and confocal microscopy.

Key results:

Antigen challenge induced dose- and time-dependent neutrophil recruitment and production of KC/CXCL1, LIX/CXCL5 and TNF-α, but not MIP-2/CXCL2, in peritoneal exudates. Neutrophil recruitment was inhibited by treatment with reparixin (CXCR1/2 antagonist), anti-KC/CXCL1, anti-LIX/CXCL5 or anti-TNF-α antibodies and in tumour necrosis factor receptor 1-deficient mice. Intraperitoneal injection of KC/CXCL1 and LIX/CXCL5 induced dose- and time-dependent neutrophil recruitment and TNF-α production, which were inhibited by reparixin or anti-TNF-α treatment. Macrophages and mast cells expressed CXCR2 receptors. Increased macrophage numbers enhanced, while cromolyn sodium (mast cell stabilizer) diminished, LIX/CXCL5-induced neutrophil recruitment. Macrophages and mast cells from immunized mice produced TNF-α upon LIX/CXCL5 stimulation. Methylated bovine serum albumin induced expression of ICAM-1 on mesenteric vascular endothelium, which was inhibited by anti-TNF-α or anti-LIX/CXCL5.

Conclusion and implications:

Following antigen challenge, CXCR2 ligands are produced and act on macrophages and mast cells triggering the production of TNF-α, which synergistically contribute to neutrophil recruitment through induction of the expression of ICAM-1.     

Thresholds for perceiving metallic taste at high magnetic field

PURPOSE: To perform an initial characterization of the metallic taste effect observed by some workers when moving around an MRI scanner. MATERIALS AND METHODS: A total of 21 subjects performed controlled movements in the stray field of a 7-T scanner. Rates of change of magnetic flux were recorded during the study using a custom-built three-axis coil unit connected to a data logger. RESULTS: Relatively normal movements could generate switched fields of 2 T/second. Of the 21 subjects, 12 detected a metallic taste, but the threshold at which it was perceived varied greatly between subjects, with the minimum dB/dt value at which such a taste was detected being 1.3 T/second. The threshold also depended on the direction of movement. CONCLUSION: This study indicates that 50% of subjects will perceive a metallic taste for head shaking with a period of 1.5 seconds (magnetic field in an anterior/posterior direction) causing a dB/dt of 2.3 +/- 0.3 T/second. The presence of dental fillings is not a requirement for the sensation of metallic taste.     

Acute generalized exanthematous pustulosis due to thallium

Acute generalized exanthematous pustulosis (AGEP) is characterized clinically by fever, pruritus and acute pustular eruption. Usually a drug is found to be the responsible agent. We present a patient who experienced an acute generalized exanthematous pustulosis due to radioactive thallium. The eruption cleared rapidly after discontinuation of the drug and systemic corticosteroid therapy.     

急性缺血性卒中影像学检查的建议——美国心脏协会的科学声明（中）

2．3核磁共振血管成像（MRA） 2．3．1背景和方法：在头部MRI检查中常结合MRA,用于急性卒中患者病情评估以指导治疗决策的制定^[19]。日前,有几种不同的MRA技术用于脑血管成像,包括二维时间飞跃（timeof-flight,TOF）序列、三维TOF序列、     

骨质疏松性椎体骨折模型的建立

目的:建立大鼠的骨质疏松性椎体骨折模型,探讨骨折愈合程度与X射线、骨结构和力学性能的相互关系,以期能为临床治疗提供科学的指导和理论依据。方法:实验于2005-07/2006-07在解放军兰州军区总医院骨研所完成。实验动物:选择雌性SPF级8个月龄SD大鼠54只。实验分组:采用随机数字法将大鼠分为2组:骨质疏松组和对照组,每组27只。实验干预:骨质疏松组经双背侧手术切除卵巢,对照组行伪手术。术后3个月,所有动物麻醉下,采用L5椎体手术开窗刮除术区内松质骨方法建立人工椎体骨折模型。实验评估:于术后1,2,4,6,8,12周观察两组大鼠腰椎影像学、骨组织切片组织学与受累椎体力学性能。结果:54只SD大鼠全部进入结果分析。①影像学观察:术后两组X射线片示L5椎体有一骨折缺损透光区。对照组在术后6周时原透光区与周围骨质无明显差别,而骨质疏松组原透光区仍清晰可见,于8周时无明显差别。②组织学观察:两组软骨细胞在骨愈合1周时出现,形成软骨岛,但骨质疏松组软骨细胞每高倍视野数量明显少于对照组,另外,软骨细胞改建成成熟骨细胞,骨小梁形成数量,胶原纤维排列与对照组比较有显著性差异。③力学性能:在骨质愈合6～12周,L5椎体的最大载荷、弹性模量、最大应力明显低于同期对照组,差异有显著性意义(P<0.05)。结论:骨质疏松性椎体骨折SD大鼠模型,符合动物模型标准,可用于研究新骨形成与正常骨质结构关系,观察骨质疏松性椎体骨折愈合机制,并证明骨质疏松性松质骨骨折修复过程中,骨折愈合质量降低。     

Serum pregnancy-specific beta1-glycoprotein before embryo transfer is related to endometrial thickness and to outcome prognosis in women undergoing in-vitro fertilization treatment

We have previously observed the repeated presence of low but detectable amounts of the trophoblast marker pregnancy-specific beta1-glycoprotein (SP1) in the serum of some women undergoing in-vitro fertilization (IVF) treatment around the time of oocyte retrieval. The occurrence of these signals seemed to be restricted to a defined group of patients which also showed a lower pregnancy success rate in a preliminary study. To test our hypothesis we have analysed 173 consecutive cycles leading to an embryo transfer. Fifty-four cycles (31%) had a serum SP1 level of at least 0.1 ng/ml between days embryo transfer -5 and embryo transfer (group A). Five pregnancies were obtained in this group (pregnancy rate = 9.3%), while in group B, defined by the absence of detectable SP1 before embryo transfer (119 cycles), 36 ongoing pregnancies were achieved (30.3%). Ten of the 41 pregnancies were achieved in 33 first-time non-pregnant patients undergoing further attempts during the study period. Again the pregnancy rate was higher in the first-time group B women (9/23 versus 1/10 for group A). Patients tended to remain in their groups A or B, the latter being associated with a better immediate as well as subsequent chance for pregnancy. Group A cycles had a significantly lower endometrial thickness two days before oocyte retrieval than group B (P = 0.0011). We postulate that the presence of an unknown, maternal and progesterone- or follicle stimulating hormone-independent factor in some patients could stimulate tonic ectopic SP1 synthesis and at the same time negatively influence endometrial development.      

O等位基因引起ABO基因型与表现型定型差异

保证输血时血清学方面的安全,首要的是对受血者与献血者ABO血型定型,血清学检查通常分两个步骤.正定型通常使用鼠源单克隆抗体检测红细胞表面是否存在A或B抗原.互补的实验即反定型,利用当红细胞上缺乏A或B抗原时,人群可天然产生相对应的抗体的原理,检测血清中是否存在抗-A或者抗-B抗体.确定了受血者红细胞表面的ABO抗原以及血浆中的抗体,便能确定血型,为其提供相合的血液.