Intermediate fenestrations reduce flow reversal in a silicone model of Stanford Type B aortic dissection

Pulsatile, three-dimensional hemodynamic forces influence thrombosis, and may dictate progression of aortic dissection. Intimal flap fenestration and blood pressure are clinically relevant variables in this pathology, yet their effects on dissection hemodynamics are poorly understood. The goal of this study was to characterize these effects on flow in dissection models to better guide interventions to prevent aneurysm formation and false lumen flow. Silicone models of aortic dissection with mobile intimal flap were fabricated based on patient images and installed in a flow loop with pulsatile flow. Flow fields were acquired via 4-dimensional flow MRI, allowing for quantification and visualization of relevant fluid mechanics. Pulsatile vortices and jet-like structures were observed at fenestrations immediately past the proximal entry tear. False lumen flow reversal was significantly reduced with the addition of fenestrations, from 19.2 ± 3.3% in two-tear dissections to 4.67 ± 1.5% and 4.87 ± 1.7% with each subsequent fenestration. In contrast, increasing pressure did not cause appreciable differences in flow rates, flow reversal, and vortex formation. Increasing the number of intermediate tears decreased flow reversal as compared to two-tear dissection, which may prevent false lumen thrombosis, promoting persistent false lumen flow. Vortices were noted to result from transluminal fluid motion at distal tear sites, which may lead to degeneration of the opposing wall. Increasing pressure did not affect measured flow patterns, but may contribute to stress concentrations in the aortic wall. The functional and anatomic assessment of disease with 4D MRI may aid in stratifying patient risk in this population.     

Perineal repair of a full‐thickness rectal prolapse in a wild Sumatran orangutan (Pongo abelii)

A Delorme's procedure perineal surgical repair was performed in a wild adult male Sumatran orangutan (Pongo abelii) with a chronic persistent rectal prolapse that had been unsuccessfully treated by 6 previous surgeries. The rectal prolapse did not recur, and the orangutan was successfully released to the wild, 6 weeks later.     

Potential roles and targeted therapy of the CXCLs/CXCR2 axis in cancer and inflammatory diseases

The chemokine receptor CXCR2 and its ligands are implicated in the progression of tumours and various inflammatory diseases. Activation of the CXCLs/CXCR2 axis activates multiple signalling pathways, including the PI3K, p38/ERK, and JAK pathways, and regulates cell survival and migration. The CXCLs/CXCR2 axis plays a vital role in the tumour microenvironment and in recruiting neutrophils to inflammatory sites. Extensive infiltration of neutrophils during chronic inflammation is one of the most important pathogenic factors in various inflammatory diseases. Chronic inflammation is considered to be closely correlated with initiation of cancer. In addition, immunosuppressive effects of myeloid-derived suppressor cells (MDSCs) against T cells attenuate the anti-tumour effects of T cells and promote tumour invasion and metastasis. Over the last several decades, many therapeutic strategies targeting CXCR2 have shown promising results and entered clinical trials. In this review, we focus on the features and functions of the CXCLs/CXCR2 axis and highlight its role in cancer and inflammatory diseases. We also discuss its potential use in targeted therapies.     

Automated identification of Fos expression

The concentration of Fos, a protein encoded by the immediate-early gene c-fos, provides a measure of synaptic activity that may not parallel the electrical activity of neurons. Such a measure is important for the difficult problem of identifying dynamic properties of neuronal circuitries activated by a variety of stimuli and behaviours. We employ two-stage statistical pattern recognition to identify cellular nuclei that express Fos in two-dimensional sections of rat forebrain after administration of antipsychotic drugs. In stage one, we distinguish dark-stained candidate nuclei from image background by a thresholding algorithm and record size and shape measurements of these objects. In stage two, we compare performance of linear and quadratic discriminants, nearest-neighbour and artificial neural network classifiers that employ functions of these measurements to label candidate objects as either Fos nuclei, two touching Fos nuclei or irrelevant background material. New images of neighbouring brain tissue serve as test sets to assess generalizability of the best derived classification rule, as determined by lowest cross-validation misclassification rate. Three experts, two internal and one external, compare manual and automated results for accuracy assessment. Analyses of a subset of images on two separate occasions provide quantitative measures of inter- and intra-expert consistency. We conclude that our automated procedure yields results that compare favourably with those of the experts and thus has potential to remove much of the tedium, subjectivity and irreproducibility of current Fos identification methods in digital microscopy.     

Increase of anti-inflammatory cytokines in patients with esophageal cancer after perioperative treatment with G-CSF

Granulocyte colony-stimulating factor (G-CSF) has been shown to effectively stimulate granulopoiesis, in both neutropenic and in non-neutropenic patients. Recently, other effects of G-CSF on the immune system have attracted interest in treating non-neutropenic patients with a high risk of severe infection. In this phase II trial, we measured the effects of G-CSF on the serum cytokine levels in patients with esophageal cancer undergoing esophagectomy. Twenty subsequent patients (study group, 19 evaluable) received G-CSF (rhG-CSF, Filgrastim) at standard doses (300 microg or 480 microg) subcutaneously 2 days before and up to 7 days after surgery. G-CSF was well tolerated. Leukocytes increased from 7600/microl at study entry (day -2) to a maximum of 45 100/microl (day 6). In the study patients, we found a highly significant (P<0.001) postoperative increase of G-CSF, IL-1ra, sTNFRp55 and sTNFRp75 as compared with the baseline level. In contrast, IL-8 levels were decreased by a factor of 6.8; there were no changes in the very low TNF-alpha levels. The comparison of the study group with a control group of 21 cancer patients undergoing major surgery who were not treated with G-CSF showed significant differences in the serum levels of G-CSF, sTNFRp55, sTNFRp75, and IL-1ra, respectively. There was no infection in the study group up to 10 days after surgery as compared with 29.9% in a historical control group (P=0.008). Thus, the induction of anti-inflammatory cytokines and the downregulation of pro-inflammatory cytokines by G-CSF might be a promising adjuvant treatment of infectious complications in patients undergoing esophagectomy.     

Reversal of Ketamine/Xylazine combination anesthesia by Atipamezole in olive baboons (Papio anubis)

Background  The potential of Atipamezole (ATI) to reverse Ketamine/Xylazine (KET/XYL) anesthesia in the Olive baboon ( Papio anubis ) was studied.
Methods  Anesthesia was induced with 10 mg/kg KET and 0.5 mg/kg XYL intramuscularly. Mean arousal time (MAT), heart rate (HR), systolic arterial blood pressure (SAP), rectal temperature, respiratory rate (RR), and hemoglobin oxygen saturation (SpO₂) were monitored. Baboons were treated with: KET/XYL only, KET/XYL followed by 100 μg/kg ATI or by 200 μg/kg ATI administered 25 minutes after KET/XYL.
Results  Atipamezole rapidly reversed depressed HR and SAP (10 ± 5.2 minutes), RR (5 ± 2 minutes) and SpO₂ (3 ± 6 minutes) and significantly decreased MAT (13 ± 2.2 minutes) vs. KET/XYL alone (35 ± 5 minutes). Emesis was absent and salivation was observed after administration of 200 μg/kg ATI only.
Conclusions  Atipamezole at 100 μg/kg is sufficient for rapid and smooth reversal of KET/XYL anesthesia in the Olive baboon with minimal side effects.     

右美托咪定联合舒芬太尼术后镇痛对卵巢癌根治术患者细胞免疫功能和炎症应激反应的影响

摘要 目的：探讨右美托咪定联合舒芬太尼术后镇痛对卵巢癌根治术患者细胞免疫功能和炎症应激反应的影响。方法：根据随机数字表法将2020年2月至2023年2月期间陕西省肿瘤医院120例择期行卵巢癌根治术的患者分为对照组（n=60，术后镇痛药物选用舒芬太尼）和研究组（n=60，术后镇痛药物选用右美托咪定联合舒芬太尼）。对比两组镇静（Ramsay镇静评分）、细胞免疫功能[CD3⁺、CD4⁺、CD8⁺、CD4⁺/CD8⁺]、镇痛情况[视觉模拟评分法（VAS）]、不良反应、炎症应激反应[白细胞介素-6（IL-6）、肿瘤坏死因子-α（TNF-α）、皮质醇（Cor）和去甲肾上腺素（NE）]变化情况。结果：与对照组术后6 h、12 h、24 h、48 h 相比，研究组同时间点VAS评分更低，Ramsay镇静评分更高（P<0.05）。与对照组术后24 h相比，研究组同时间点CD3⁺、CD4⁺、CD4⁺/CD8⁺更高，CD8⁺更低（P<0.05）。两组不良反应发生率组间对比未见差异（P>0.05）。与对照组术后24 h相比，研究组同时间点IL-6、TNF-α、Cor、NE更低（P<0.05）。结论：右美托咪定联合舒芬太尼用于卵巢癌根治术患者术后镇痛，镇静、镇痛效果显著，同时还可减轻机体炎症应激反应，缓解免疫抑制。     

CBL联合PBL教学方法在创伤外科学教学中的初步探究

目的:研究以案例为中心教学法(CBL)联合以问题为中心教学法(PBL)的教学方法与传统的基于课堂的教学法(LBL)在临床医学五年制本科生创伤外科学教学中的应用效果。方法:随机选取我校临床医学五年制四年级的学员80人,随机分为CBL联合PBL教学组及LBL教学组各40人。在课程结束以后,采用记名试卷考核联合不记名问卷调查的方式,进行教学方法、教学模式、教学内容掌握程度评价。结果:实验组学员理论考核成绩优于对照组学员,有统计学差异。CBL联合PBL教学法支持率高于传统LBL教学法,并且在激发学员兴趣,提高学员学习兴趣,合作能力方面均优于对照组。结论:CBL联合PBL教学法可以在创伤外科学中实施,能取得较好的教学效果。     

早期胃癌的治疗现状与进展

胃癌是常见的消化道肿瘤之一,是我国死亡率最高的恶性肿瘤之一。与日本韩国等发达国家相比,我国胃癌患者多数在就诊时已处于进展期,早期胃癌所占比例不足10%。传统的开腹胃癌手术仍是治疗早期胃癌的主要手段。相较于传统开腹手术,腹腔镜手术对于早期胃癌的治疗优势是显而易见的。早期胃癌患者行腹腔镜手术,具有术后恢复快,生活质量好,近期疗效佳等优势。内镜黏膜下剥离术(ESD,endoscopic submucosal dissection)是近年来出现的一项新的治疗早期胃癌的手段。本文就传统开腹手术、腹腔镜手术及ESD分别在早期胃癌治疗中的应用进行了综述。微创手术治疗早期胃癌将逐渐代替开腹手术,成为早期胃癌治疗的主要手段。     

硬膜外复合全麻对老年高血压患者腹部手术后并发症的影响

目的：探讨硬膜外复合全麻对老年高血压患者腹部手术后并发生的影响。方法：收集2013 年6 月-2015 年6 月在两家医院 接受腹部手术的老年高血压患者100 例,根据麻醉方法不同分为研究组和对照组。研究组患者给予硬膜外复合麻醉,对照组给予 全凭静脉麻醉。观察并比较两组患者的麻醉时间、药物用量以及术后并发症的发生率。结果：两组麻醉时间比较,差异无统计学意 义（P>0.05）;研究组麻醉药物用量低于对照组,差异具有统计学意义（P<0.05）;两组患者手术时间比较,差异无统计学意义（P>0. 05）;研究组患者术后苏醒时间、拔管时间以及住院时间均短于对照组,差异具有统计学意义（P<0.05）;研究组术后并发症的发生 率低于对照组,差异具有统计学意义（P<0.05）。结论：硬膜外复合全麻用于老年高血压患者腹部手术能够减少麻醉药物用量,降低 术后并发症的发生率,安全性较高。