Effect of lumbar fasciae on the stability of the lower lumbar spine

The biomechanical effect of tensioning the lumbar fasciae (LF) on the stability of the spine during sagittal plane motion was analysed using a validated finite element model of the normal lumbosacral spine (L4-S1). To apply the tension in the LF along the direction of the fibres, a local coordinate was allocated using dummy rigid beam elements that originated from the spinous process. Up to 10 Nm of flexion and 7.5 Nm of extension moment was applied with and without 20 N of lateral tension in the LF. A follower load of 400 N was additionally applied along the curvature of the spine. To identify how the magnitude of LF tension related to the stability of the spine, the tensioning on the fasciae was increased up to 40 N with an interval of 10 N under 7.5 Nm of flexion/extension moment. A fascial tension of 20 N produced a 59% decrease in angular motion at 2.5 Nm of flexion moment while there was a 12.3% decrease at 10 Nm in the L5-S1 segment. Its decrement was 53 and 9.6% at 2.5 Nm and 10 Nm, respectively, in the L4-L5 segment. Anterior translation was reduced by 12.1 and 39.0% at the L4-L5 and L5-S1 segments under 10 Nm of flexion moment, respectively. The flexion stiffness shows an almost linear increment with the increase in fascial tension. The results of this study showed that the effect of the LF on the stability of the spine is significant.     

糖皮质激素联合利妥昔单抗对特发性膜性肾病患者血脂、Th17/Treg失衡和血清PLA2R抗体、THSD7A抗体的影响

摘要 目的：探讨糖皮质激素联合利妥昔单抗对特发性膜性肾病（IMN）患者血脂、辅助性T细胞17（Th17）/调节性T细胞（Treg）失衡和血清抗磷脂酶A2受体（PLA2R）抗体、抗I型血小板反应蛋白7A域（THSD7A）抗体的影响。方法：收集空军军医大学唐都医院2022年3月~2023年3月期间收治的IMN患者112例。根据随机数字表法将入组患者分为对照组（56例,糖皮质激素治疗）与治疗组（56例,对照组的基础上接受利妥昔单抗治疗）。观察两组疗效、血脂[低密度脂蛋白胆固醇（LDL-C）、总胆固醇（TC）、高密度脂蛋白胆固醇（HDL-C）、甘油三酯（TG）]、肾功能[胱抑素C（CysC）、血肌酐（Scr）、血尿素氮（BUN）、24 h尿蛋白定量]、Th17/Treg相关指标[Th17细胞百分比、白细胞介素-17（IL-17）、Treg细胞百分比、转化生长因子β1（TGF-β1）、肿瘤坏死因子-α（TNF-α）]和血清PLA2R抗体、THSD7A抗体水平变化情况,并观察两组治疗安全性。结果：与对照组相比,治疗组的临床总有效率更高（P<0.05）。与对照组相比,治疗组治疗6个月后TC、TG、LDL-C、CysC、Scr、BUN、24 h尿蛋白定量、Th17、IL-17、TNF-α、PLA2R抗体、THSD7A抗体更低,HDL-C、Treg、TGF-β1更高（P<0.05）。两组不良反应发生率对比未见差异（P>0.05）。结论：糖皮质激素联合利妥昔单抗应用于IMN患者,可有效改善患者血脂、Th17/Treg失衡和血清PLA2R抗体、THSD7A抗体水平,且不增加不良反应发生率,具有较好的临床应用价值。     

Fluorescence Microscopy Gets Faster and Clearer: Roles of Photochemistry and Selective Illumination

Significant advances in fluorescence microscopy tend be a balance between two competing qualities wherein improvements in resolution and low light detection are typically accompanied by losses in acquisition rate and signal-to-noise, respectively. These trade-offs are becoming less of a barrier to biomedical research as recent advances in optoelectronic microscopy and developments in fluorophore chemistry have enabled scientists to see beyond the diffraction barrier, image deeper into live specimens, and acquire images at unprecedented speed. Selective plane illumination microscopy has provided significant gains in the spatial and temporal acquisition of fluorescence specimens several mm in thickness. With commercial systems now available, this method promises to expand on recent advances in 2-photon deep-tissue imaging with improved speed and reduced photobleaching compared to laser scanning confocal microscopy. Superresolution microscopes are also available in several modalities and can be coupled with selective plane illumination techniques. The combination of methods to increase resolution, acquisition speed, and depth of collection are now being married to common microscope systems, enabling scientists to make significant advances in live cell and in situ imaging in real time. We show that light sheet microscopy provides significant advantages for imaging live zebrafish embryos compared to laser scanning confocal microscopy.     

Identification of Stmm3 locus Conferring Resistance to Late-stage Chemically Induced Skin Papillomas on Mouse Chromosome 4 by Congenic Mappingand Allele-specific Alteration Analysis

Genome-wide association studies have revealed that many low-penetrance cancer susceptibility loci are located throughout the genome; however, a very limited number of genes have been identified so far. Using a forward genetics approach to map such loci in a mouse skin cancer model, we previously identified strong genetic loci conferring resistance to chemically induced skin papillomas on chromosome 4 and 7 with a large number of [(FVB/N × MSM/Ms) F₁ × FVB/N] backcross mice. In this report, we describe a combination of congenic mapping and allele-specific alteration analysis of the loci on chromosome 4. We used linkage analysis and a congenic mouse strain, FVB.MSM-Stmm3 to refine the location of Stmm3 (Skin tumor modifier of MSM 3) locus within a physical interval of about 34 Mb on distal chromosome 4. In addition, we used patterns of allele-specific imbalances in tumors from N₂ and N₁₀ congenic mice to narrow down further the region of Stmm3 locus to a physical distance of about 25 Mb. Furthermore, immunohistochemical analysis showed papillomas from congenic mice had less proliferative activity. These results suggest that Stmm3 responsible genes may have an influence on papilloma formation in the two-stage skin carcinogenesis by regulating papilloma growth rather than development.     

PM2.5暴露荷瘤裸鼠后肠道菌群组成的改变

目的了解暴露PM_(2.5)后的Bac荷瘤裸鼠肠道菌群组成的变化。方法采用A549细胞对30只Bac裸鼠进行肺内注射,饲养1周适应环境,第2周开始进行暴露染尘与对照暴露生理盐水组实验,共暴露1、4、8周。采用口鼻暴露仓进行小鼠染尘与生理盐水暴露操作,每周暴露6d,每天2h,建立大气污染暴露荷瘤裸鼠模型,5只未做处理的Bac荷瘤裸鼠作为空白对照组。采集裸鼠晨起新鲜粪便样品,抽提其中微生物总基因组DNA,采用Ⅱ代基因测序技术对粪便样品进行16S高变区扩增测序,划分可操作分类单元(operational taxonomic unit,OTU),使用I-Sanger分析平台对所有OTU进行物种注释与评估、物种组成分析、样本比较分析等,运用R Studio软件对数据进行统计学分析。结果厚壁菌门和拟杆菌门在PM_(2.5)暴露组、生理盐水对照组和空白对照组均为最优势菌门。PM_(2.5)暴露组与生理盐水对照组及空白对照组相比厚壁菌门减少,拟杆菌门增加。结论 PM_(2.5)暴露减少Bac荷瘤裸鼠肠道菌群丰度,破坏肠道菌群平衡,在一定程度上可抑制有益菌的繁殖,并使致病菌数量增加。     

阴道菌群结构分析在 宫腔粘连患者中的临床意义

目的对宫腔粘连患者菌群结构进行评价,探讨阴道微生态在宫腔粘连中的临床意义。方法选取2014年8月至2016年8月在我院计划生育病区诊断为宫腔粘连的患者100例为试验组,同期门诊100例健康体检者为对照组。对其阴道分泌物进行湿片镜检及微生态学检测,比较两组研究对象的阴道微生态情况。结果宫腔粘连组与对照组在阴道分泌物的多样性、密集度、优势菌、pH、清洁度和病原体检出率等方面比较差异有统计学意义(Ps0.05)。宫腔粘连组阴道微生态失调检出率(48%)高于对照组(31%),差异有统计学意义(P0.05)。结论宫腔粘连患者阴道微生态失调发生率明显增高,阴道微生态失调可能与宫腔粘连的发生有关。     

Organization of cortical microtubules at the plasma membrane in Arabidopsis

 To understand the role of microtubules in the regulation of cell elongation, we characterized microtubule patterns in fass, a cell shape mutant of Arabidopsis thaliana (L.) Heynh. Examining microtubule patterns via immunocytochemistry, we found that fass cells were able to organize their microtubules into mitotic spindles and phragmoplasts. During interphase or preprophase, fass cells had cortical microtubules, verified by transmission electron microscopy, but these microtubules were not organized into the cortical array or preprophase band. Using chromatin condensation and tubulin localization on the nuclear envelope as preprophase stage markers, we found that although fass cells lacked the preprophase band and cortical array, their cell division cycle appeared normal. To pinpoint the defect in fass cells, we delineated the sequential events leading to cortical array formation in Arabidopsis cells and found that fass cells initiated and recolonized cortical microtubules in the same manner as wild-type cells, but failed to order them into the cortical array. Taken together, these results suggest fass cells are impaired in a component of the microtubule organizing center(s) required for the proper ordering of cortical microtubules at the plasma membrane. Received: 23 August 1996 / Accepted: 25 September 1996