Expression of tissue inhibitor of metalloprotease 3 is reduced in ischemic but not neuropathic ulcers from patients with type 2 diabetes mellitus

Diabetic foot ulceration remains one of the most common and most serious consequences of diabetes. Persistently high levels of matrix metalloproteases (MMPs) contribute to wound chronicity. Our aim was to assess the concentrations of MMPs and tissue inhibitors of metalloproteinases (TIMPs) in neuropathic and ischemic diabetic foot ulcers by analyzing biopsy samples. In this study, biopsies were taken from 35 diabetic foot ulcers of type 2 diabetes mellitus patients and distinguished in neuropathic (n = 14) or ischemic (n = 21). Zymography assay was utilized for the analysis of MMP-2 and MMP-9 activity. TACE activity was evaluated by a specific fluorimetric assay. mRNA levels of MMPs as well as TIMPs were detected using quantitative real-time polymerase chain reaction. The activity of MMP9 and A Disintegrin and A MetalloProtease Domain 17/TNF-Alpha Converting Enzyme (ADAM17/TACE) was significantly increased in ischemic compared to neuropathic biopsies. No differences were detected between both groups for the mRNA levels of MMPs as well as of ADAMs. However, TIMP3 mRNA expression was decreased in ischemic samples. The combination of increased activity of MMP9 and ADAM17/TACE with decreased concentrations of TIMP-3 mRNA expression in ischemic diabetic foot ulcers compared to neuropathic samples suggests that the increased proteolytic environment may represent a causative factor in the ulcer progression. New treatment strategies for healing diabetic foot ulcers could be directed toward increasing levels of TIMP3.     

Synthesis and Characterization of Hyperbranched Polyethylenes Made with Nickel‐α‐Diimine Catalysts

The polymerization of ethylene in the presence of 1,4‐bis(2,6‐diisopropylphenyl)acenaphthenediiminenickel(II) dichloride ( 1 ) and methylaluminoxane (MAO) gives hyperbranched polyethylene (HBPE) in appropriate reaction conditions. The system 1 /MAO is active in solvents like toluene or hexane at temperatures as high as 80 °C and ethylene pressures ranging from 1 to 15 atm. The polyethylenes obtained show high molecular weights (up to 467 kg · mol^?1) and more than 218 branches per 1 000 backbone carbon atoms, qualifying these materials as hyperbranched. Dynamic‐mechanical thermal analysis (DMTA) of these materials shows high β‐transitions, directly related to the branch content of these polyethylenes.

DMTA analysis of polyethylenes obtained with 1 /MAO at 0, 30, and 50 °C (corresponding to entries 1, 2 and 3).     

Serotypes of carriage and invasive isolates of Streptococcus pneumoniae in Brazilian children in the era of pneumococcal vaccines

Nasopharyngeal carriage of Streptococcus pneumoniae is a key factor in the development of invasive disease and the spread of resistant strains within the community. A single nasopharyngeal swab was obtained from 648 unvaccinated children aged <5 years, either healthy or with acute respiratory tract infection or meningitis, during the winters of 2000 and 2001. The overall pneumococcal carriage rate was 35.8% (95% CI 32.1-39.6). The pneumococcal serotypes found most frequently in the nasopharynx were 14, 6B, 6A, 19F, 10A, 23F and 18C, which included five of the seven serotypes in the currently licensed seven-valent conjugate vaccine (PCV7); serotypes 4 and 9V were less common. Serotypes 1 and 5 were isolated rarely from the nasopharynx. A comparison of 222 nasopharyngeal isolates with 125 invasive isolates, matched for age and time to the carrier isolates, showed a similar prevalence of penicillin non-susceptible pneumococci (PNSp) (19.8% and 19.2%, respectively). PNSp serotypes were similar (6B, 14, 19F, 19 A, 23B and 23F) for carriage and invasive disease isolates. The coverage of PCV7 for carriage isolates (52.2%) and invasive isolates (62.4%) did not differ significantly (p 0.06); similarly, there was no significant difference in PCV7 coverage for carriage isolates (34.5%) and invasive isolates (28.2%) of PNSp. These data suggest that PCV7 has the potential to reduce pneumococcal carriage and the number of carriers of PNSp belonging to vaccine serotypes.     

Correlates of motor planning and postsaccadic fixation in the macaque monkey lateral geniculate nucleus

There is significant controversy regarding the ability of the primate visual system to construct stable percepts from a never-ending stream of brief fixations and rapid saccadic eye movements. In this study, we examined the timing and occurrence of perisaccadic modulation of LGN single-unit activity in awake-behaving macaque monkeys while they made spontaneous saccades in the dark and made visually guided saccades to discrete stimuli located outside the receptive field. Our hypothesis was that the activity of LGN cells is modulated by efference copies of motor plans to produce saccadic eye movements and that this modulation depends neither on the presence of feedforward visual information nor on a corollary discharge of signals directing saccadic eye movements. On average, 25% of LGN cells demonstrated significant perisaccadic modulation. This modulation consisted of a moderate suppression of activity that began more than 100 ms prior to the initiation of a saccadic eye movement and continued beyond the termination of the saccadic eye movement. This suppression was followed by a large enhancement of activity after the eyes arrived at the next fixation. Although members of all three LGN relay cell classes (magnocellular, parvocellular, and koniocellular) demonstrated significant saccade-related suppression and enhancement of activity, more cells demonstrated postsaccadic enhancement (25%) than perisaccadic suppression (17%). In no case did the timing of the modulation coincide directly with saccade duration. The degree of modulation observed did not vary with LGN cell class, LGN receptive field center location, center sign (ON-center or OFF-center), or saccade latency or velocity. The time course of modulation did, however, vary with saccade size such that suppression was longer for longer saccades. The fact that activity from a percentage of LGN cells from all cell classes was modulated in relationship to saccadic eye movements in the absence of direct visual stimulation suggests that this modulation is a general phenomenon not tied to specific types of visual stimuli. Similarly, because the onset of the modulation preceded eye movements by more than 100 ms, it is likely that this modulation reflects higher order motor-planning rather than a corollary of mechanisms in direct control of eye movements themselves. Finally, the fact that the largest modulation is a postsaccadic enhancement of activity may suggest that perisaccadic modulations are designed more for the facilitation of visual information processing once the eyes land at a new location than for filtering unwanted visual stimuli.     

肠镜在腹腔镜辅助低位直肠癌根治术后吻合口出血防治中的意义

目的:探讨肠镜在腹腔镜辅助低位直肠癌根治术后吻合口出血防治中的意义。方法 :回顾性分析我院2006年1月至2011年12月共279例腹腔镜直肠癌根治术病人的资料,其中18例术后吻合口出血。采用卡方检验分析影响吻合口出血的可能因素,对于P     

Incidence of Cancer Following Bariatric Surgery: Systematic Review and Meta-analysis

Obesity is linked to the development of cancer. Previous studies have suggested that there is a relationship between bariatric surgery and reduced cancer risk. Data sources were from Medline, Embase, and Cochrane Library. From 951 references, 13 studies met the inclusion criteria (54,257 participants). In controlled studies, bariatric surgery was associated with a reduction in the risk of cancer. The cancer incidence density rate was 1.06 cases per 1000 person-years within the surgery groups. In the meta-regression, we found an inverse relationship between the presurgical body mass index and cancer incidence after surgery (beta coefficient ?0.2, P?相似文献   

Can we observe collective neuronal activity from macroscopic aggregate signals?

The fundamental problem faced by noninvasive neuroimaging techniques such as EEG/MEG¹ is to elucidate functionally important aspects of the microscopic neuronal network dynamics from macroscopic aggregate measurements. Due to the mixing of the activities of large neuronal populations in the observed macroscopic aggregate, recovering the underlying network that generates the signal in the absence of any additional information represents a considerable challenge. Recent MEG studies have shown that macroscopic measurements contain sufficient information to allow the differentiation between patterns of activity, which are likely to represent different stimulus-specific collective modes in the underlying network (Hadjipapas, A., Adjamian, P., Swettenham, J.B., Holliday, I.E., Barnes, G.R., 2007. Stimuli of varying spatial scale induce gamma activity with distinct temporal characteristics in human visual cortex. NeuroImage 35, 518–530). The next question arising in this context is whether aspects of collective network activity can be recovered from a macroscopic aggregate signal. We propose that this issue is most appropriately addressed if MEG/EEG signals are to be viewed as macroscopic aggregates arising from networks of coupled systems as opposed to aggregates across a mass of largely independent neural systems. We show that collective modes arising in a network of simulated coupled systems can be indeed recovered from the macroscopic aggregate. Moreover, we show that nonlinear state space methods yield a good approximation of the number of effective degrees of freedom in the network. Importantly, information about hidden variables, which do not directly contribute to the aggregate signal, can also be recovered. Finally, this theoretical framework can be applied to experimental MEG/EEG data in the future, enabling the inference of state dependent changes in the degree of local synchrony in the underlying network.     

高效液相色谱法测定炎痛净乳膏中双氯芬酸钠和苯佐卡因的含量

目的：测定炎痛净乳膏中双氯芬酸钠和苯佐卡因的含量。方法：高效液想象以谱法，甲醇为提取溶剂，地西泮为内标，No-va-PakC18色谱柱，甲醇-水-冰醋酸（80：20：0.5)为流动相，检测波长为283nm。结果：双氯芬酸钠和苯佐卡因在5μg/ml-40μg/ml范围内，其浓度与峰面积均呈良好的线性关系（r=0.9999)，平均回收率分别为101.0%,RSD=1.21%,99.8%,RSD=0.62%。结论：本法专属性强，操作简便，结果准确。     

拉萨地区冠心病与幽门螺杆菌感染相关性研究

目的探讨西藏拉萨地区幽门螺杆菌（Helicobacter pyloric,Hp）感染与冠心病及多种危险因素的关系。为该地区冠心病的防治提供依据。方法分为冠心病组46例和非冠心病组51例,应用检测血抗HpIgG及-C-尿素呼气试验方法检测Hp感染情况,并分别测定各组血脂、血糖、餐后2h血糖、C反应蛋白、纤维蛋白原、白细胞总数。结果冠心病组患者血清抗HpIgG阳性率为50．0％（23／46）,明显高于非冠心病组的23．5％（12／51）,P〈0．05;冠心病患者Hp现症感染率为54．3％（25／46）,明显高于非冠心病组的31．3％（27／51）,P〈0．05;冠心病组Hp感染患者血脂、空腹及餐后2h血糖、C反应蛋白、纤维蛋白原较非感染患者明显升高（P〈0．05）。结论Hp感染与冠心病相关,可能是拉萨地区冠心病发病的独立危险因素。