Chondromalacia patellae: assessment with MR imaging

Magnetic resonance (MR) images of the posterior patellar hyaline articular cartilage were obtained in 23 subjects to determine if MR imaging could accurately demonstrate the patellar cartilage. Arthroscopy was used as the standard of reference. Three subjects were asymptomatic volunteers. In the remaining 20 who had patellofemoral pain, arthroscopy was performed before MR imaging in seven and afterward in 12; one did not undergo arthroscopy. MR imaging showed focal areas of swelling of the patellar cartilage, focal hypointensity, surface irregularity, areas of thinning, and areas of cartilage loss with exposure of subchondral bone. The surgical findings agreed with those from MR images in all seven patients who underwent arthroscopy before MR imaging and in ten of the 12 who underwent surgery afterward. MR imaging is an accurate means of examining the posterior patellar cartilage and should be considered as an alternative to diagnostic arthroscopy when chondromalacia patellae is suspected.     

The impact of a quadrivalent human papillomavirus (types 6, 11, 16, 18) virus-like particle vaccine in European women aged 16 to 24

Background  Quadrivalent human papillomavirus (HPV types 6/11/16/18) L1 VLP vaccine is highly effective in preventing HPV 6/11/16/18-related cervical and external genital disease. Herein, we evaluated the impact of the quadrivalent HPV 6/11/16/18 L1 VLP vaccine on prevention of HPV-associated cervico-genital lesions in a broad population of sexually active European women.
Methods  Female subjects ( N = 9265) aged 16–24 with four or fewer lifetime sexual partners were enrolled and randomized to quadrivalent HPV vaccine or placebo. Subjects underwent cervicovaginal sampling for HPV DNA detection. Papanicolaou testing and anti-HPV 6/11/16/18 serology testing was also performed.
Results  Vaccine efficacy against lesions representing immediate cervical cancer precursors (cervical intraepithelial neoplasia grade 2/3 or adenocarcinoma in situ ) related to HPV 6/11/16/18 in the per-protocol population was 100.0%[95% confidence interval (95% CI), 89.8–100.0]. Efficacy against external genital lesions (vulvar or vaginal intraepithelial neoplasia, condyloma, vulvar or vaginal cancer) related to vaccine HPV types in the per-protocol European population was 99.0% (95% CI, 94.4–100.0).
Conclusion  These data demonstrate that quadrivalent HPV 6/11/16/18 vaccination programs in 16- to 24-year-old European women can be beneficial.
NCT0009252, NCT00092534, NCT00092495     

Assessment of baroreflex sensitivity in patients with preserved and impaired left ventricular function by means of the Valsalva manoeuvre and the phenylephrine test

The purpose of the present study was to assess the agreement between measurements of baroreflex sensitivity (BRS) obtained by the Valsalva manoeuvre and by the phenylephrine test in patients with previous myocardial infarction and different degrees of left ventricular dysfunction. Patients with a previous myocardial infarction were enrolled consecutively into two groups according to their left ventricular ejection fraction (LVEF): 40% (n=52). All patients underwent BRS assessment by the phenylephrine technique (Phe-BRS) and by the Valsalva manoeuvre, with the latter using both the overshoot part of phase IV (Ov-VM-BRS) and the whole of phase IV (IV-VM-BRS). The linear association between methods was assessed by correlation analysis and the agreement was evaluated by computing the bias and the limits of agreement. IV-VM-BRS and Ov-VM-BRS could not be computed in 26% and 39% of patients respectively. For both indices a much higher percentage of non-computable Valsalva manoeuvre slopes was found in the group of patients with LVEF 40% the results were: r=0.91 (P<0.001), bias=0.1 ms/mmHg (P=0.84) and limits of agreement from -4.8 to 5 ms/mmHg. When comparing Phe-BRS and IV-VM-BRS, we found r=0.67 (P=0.001), bias=-1.5 ms/mmHg (P=0.06) and limits of agreement from -8.8 to 5.7 ms/mmHg in the group of patients with LVEF 40%. Dichotomizing Ov-VM-BRS, the best cut-off value to identify patients with a Phe-BRS of <3 ms/mmHg was found to be 7 ms/mmHg, giving 100% sensitivity and 69% specificity. In conclusion, estimation of BRS by the Valsalva manoeuvre in post-myocardial infarction patients is limited by a large number of non-measurable results. When computable, measurements are well correlated with those obtained by Phe-BRS, but, because of large limits of agreement, the two methods cannot be used interchangeably. If used as a screening test for risk stratification, the Valsalva manoeuvre could reduce by about one-third the need for phenylephrine injection.     

Use of recombinant human erythropoietin to assist autologous blood donation by anemic rheumatoid arthritis patients undergoing major orthopedic surgery

BACKGROUND: In rheumatoid arthritis (RA) patients undergoing orthopedic surgery, anemia is the major factor in the use of allogeneic blood. STUDY DESIGN AND METHODS: To determine whether recombinant human erythropoietin (rHuEPO) could allow preoperative autologous blood procurement and reduce allogeneic blood exposure, 11 RA patients who were unable preoperatively to deposit blood for autologous use because of their anemia (baseline hematocrit < 34% [0.34]) and who were scheduled for primary total hip replacement or total knee replacement were treated intravenously with 300 U per kg of rHuEPO in combination with intravenous iron saccharate (100 mg), given twice weekly for 3 weeks. The transfusion treatment was compared with that in 12 control patients with comparable baseline hematologic values who underwent the same operation. RESULTS: Control patients could not preoperatively deposit any blood for autologous use, while all but one of the rHuEPO- treated patients deposited 2 or more units (mean, 2.6 +/− 0.6; range, 2- 4) (p < 0.001). The control group received more allogeneic units (2.6 +/− 1.6 vs. 0.8 +/− 0.8) (p = 0.009). Moreover, 50 percent of the rHuEPO-treated patients, as compared with 8 percent of controls, completely avoided allogeneic transfusion. CONCLUSION: Recombinant human erythropoietin is safe and effective in stimulating erythropoiesis, allowing preoperative donation of blood for autologous use, and reducing exposure to allogeneic blood for RA patients who are unable preoperatively to deposit blood because of anemia.     

针刺足三里和悬钟治疗缺血性脑卒中

目的:观察针刺足三里、悬钟2穴对缺血性脑卒中脑血管功能的影响,分析其可能的作用机制,并对临床疗效做出评价。方法:选择2004-11/2006-05湖北中医药高等专科学校附属古城医院针灸科、荆州市第五人民医院中医康复科、荆州市第三人民医院中医科3单位缺血性脑卒中患者合适病例160例,采用查随机数字表的方法,将其随机分为对照组和针刺组,各80例。对照组采用现代医学常规干预方法进行治疗:卧床,保持呼吸道通畅,预防感染,控制颅内压、血压,维持水电解质平衡。针刺组在此基础上加针刺足三里、悬钟2穴,采用慢速捻转进针法针刺,留针20～30min,每隔5min行针1次。1次/d。两组患者治疗30d。并以经颅多普勒检测观察缺血性脑卒中患者治疗前后脑血管舒缩反应能力、脑血流自动调节功能、大脑半球侧枝循环代偿功能的变化,同时以治疗前后神经功能缺损程度为指标评价其临床疗效。结果:160例病例全部进入结果分析。①针刺组与治疗前相比,脑血管舒缩反应能力明显加强,差异有显著性意义(t=2.97,P<0.05),且优于对照组(t=2.45,P<0.05)。②针刺组与治疗前相比,脑血流自动调节能力明显改善,差异有非常显著性意义(t=8.01,P<0.01),且优于对照组(t=7.67,P<0.05)。③针刺组与治疗前相比,大脑半球侧枝循环代偿功能得到加强,差异有显著性意义(t=3.15,P<0.05),且优于对照组(t=5.16,P<0.05)。④针刺组与治疗前相比,神经功能缺损积分明显降低,差异有非常显著性意义(t=4.83,P<0.01),且优于对照组(t=5.43,P<0.05)。结论:针刺足三里、悬钟2穴对缺血性脑卒中患者脑血管舒缩反应能力、脑血流自动调节功能、大脑半球侧枝循环代偿功能有明显改善作用,并能促进神经功能的恢复。     

p.R254Q mutation in the aquaporin‐2 water channel causing dominant nephrogenic diabetes insipidus is due to a lack of arginine vasopressin‐induced phosphorylation

Vasopressin regulates human water homeostasis by re‐distributing homotetrameric aquaporin‐2 (AQP2) water channels from intracellular vesicles to the apical membrane of renal principal cells, a process in which phosphorylation of AQP2 at S256 by cAMP‐dependent protein kinase A (PKA) is thought to be essential. Dominant nephrogenic diabetes insipidus (NDI), a disease in which the kidney is unable to concentrate urine in response to vasopressin, is caused by AQP2 gene mutations. Here, we investigated a reported patient case of dominant NDI caused by a novel p.R254Q mutation. Expressed in oocytes, AQP2‐p.R254Q appeared to be a functional water channel, but was impaired in its transport to the cell surface to the same degree as AQP2‐p.S256A, which mimics non‐phosphorylated AQP2. In polarized MDCK cells, AQP2‐p.R254Q was retained and was distributed similarly to that of unstimulated wt‐AQP2 or AQP2‐p.S256A. Upon co‐expression, AQP2‐p.R254Q interacted with, and retained wt‐AQP2 in intracellular vesicles. In contrast to wild‐type AQP2, forskolin did not increase AQP2‐p.R254Q phosphorylation at S256 or its translocation to the apical membrane. Mimicking constitutive phosphorylation in AQP2‐p.R254Q with the p.S256D mutation, however, rescued its apical membrane expression. These date indicate that a lack of S256 phosphorylation is the sole cause of dominant NDI here, and thereby, p.R254Q is a loss of function instead of a gain of function mutation in dominant NDI. © 2009 Wiley‐Liss, Inc.     

Relative contribution of ecto-ATPase and ecto-ATPDase pathways to the biphasic effect of ATP on acetylcholine release from myenteric motoneurons

Background and purpose:

The relative contribution of distinct ecto-nucleotidases to the modulation of purinergic signalling may depend on differential tissue distribution and substrate preference.

Experimental approach:

Extracellular ATP catabolism (assessed by high-performance liquid chromatography) and its influence on [³H]acetylcholine ([³H]ACh) release were investigated in the myenteric plexus of rat ileum in vitro.

Key results:

ATP was primarily metabolized via ecto-ATPDase (adenosine 5′-triphosphate diphosphohydrolase) into AMP, which was then dephosphorylated into adenosine by ecto-5′-nucleotidase. Alternative conversion of ATP into ADP by ecto-ATPase (adenosine 5′-triphosphatase) was more relevant at high ATP concentrations. ATP transiently increased basal [³H]ACh outflow in a 2′,3′-O-(2,4,6-trinitrophenyl)adenosine-5′-triphosphate (TNP-ATP)-dependent, tetrodotoxin-independent manner. ATP and ATPγS (adenosine 5′-[γ-thio]triphosphate), but not α,β-methyleneATP, decreased [³H]ACh release induced by electrical stimulation. ADP and ADPβS (adenosine 5′[β-thio]diphosphate) only decreased evoked [³H]ACh release. Inhibition by ADPβS was prevented by MRS 2179 (2′-deoxy-N⁶-methyl adenosine 3′,5′-diphosphate diammonium salt, a selective P2Y₁ antagonist); blockade of ADP inhibition required co-application of MRS 2179 plus adenosine deaminase (which inactivates endogenous adenosine). Blockade of adenosine A₁ receptors with 1,3-dipropyl-8-cyclopentyl xanthine enhanced ADPβS inhibition, indicating that P2Y₁ stimulation is cut short by tonic adenosine A₁ receptor activation. MRS 2179 facilitated evoked [³H]ACh release, an effect reversed by the ecto-ATPase inhibitor, {"type":"entrez-protein","attrs":{"text":"ARL67156","term_id":"1186396857","term_text":"ARL67156"}}ARL67156, which delayed ATP conversion into ADP without affecting adenosine levels.

Conclusions and implications:

ATP transiently facilitated [³H]ACh release from non-stimulated nerve terminals via prejunctional P2X (probably P2X₂) receptors. Hydrolysis of ATP directly into AMP by ecto-ATPDase and subsequent formation of adenosine by ecto-5′-nucleotidase reduced [³H]ACh release via inhibitory adenosine A₁ receptors. Stimulation of inhibitory P2Y₁ receptors by ADP generated alternatively via ecto-ATPase might be relevant in restraining ACh exocytosis when ATP saturates ecto-ATPDase activity.