Experimental and finite element analysis for prediction of kidney injury under blunt impact

Kidneys are third most injured organs in abdominal trauma after liver and spleen; this study therefore is an attempt to understand the behaviour of kidneys under blunt trauma. Dynamic impact tests were performed on 20 fresh porcine kidneys to study the injury propagation in the organ, and the acceleration of the impactor was measured. A kidney model was developed with structural details like capsule and cortex. The kidney cortex was modelled with solid hexahedral elements and the capsule was modelled with quadratic shell elements. The material models for the capsule and cortex were used from the experimental data reported in our previous study. The developed model was calibrated using previous and current experimental results to reproduce the injuries of the organ in terms of acceleration of the impactor, and the injuries sustained by the organ during the experiments. The developed kidney model is observed to be robust and can be integrated with the available human body finite element models to simulate accidents and to predict or simulate injuries.     

Capsule walls as barriers to oxygen availability: Implications for the development of brooded embryos by the estuarine gastropod Crepipatella dilatata (Calyptraeidae)

Encapsulation of developing embryos imposes potential restrictions, because the capsule wall must allow for adequate inward diffusion of oxygen and for increased diffusion of oxygen as metabolic demand increases with continued development. Samples of egg capsules from the gastropod Crepipatella dilatata were used to document surface characteristics, composition of the different capsule wall layers, and alterations in wall thickness during development. The diffusion coefficient and capsule wall permeability were determined experimentally for capsules containing embryos at different developmental stages. We also determined oxygen consumption rates for various embryonic stages and for nurse eggs, which provide food for embryos during development. The capsule wall of C. dilatata possesses 2 differentiated layers: the external capsular wall (ECW) and the internal capsular wall (ICW). The ECW is compact and fibrous, features that remain invariable during development, and lacks surface features that might make some portions of the capsule wall more permeable to oxygen than others. On the other hand, the ICW is initially spongy and thick, but significantly decreases in thickness over time, particularly before the embryos begin feeding on nurse eggs. Although the capsule wall is a serious barrier to diffusion, permeability to oxygen increases over time by 112% due to the dramatic thinning of the inner capsule wall layer. Nurse eggs consume oxygen but at very low rates, supporting the idea that they correspond to living embryonic cells that have stopped their development. Respiration measurements indicated that embryos are initially supplied with enough oxygen within the egg capsules to carry out the activities characteristic of embryogenesis, even though the capsular walls show their maximum thickness and lowest permeability at this time. However, as the embryo develops its velum and becomes more active, capsule wall thickness decreases and capsule permeability to oxygen increases. Correspondingly, the oxygen demands of metamorphosed but still encapsulated specimens are approximately 135% higher than those of pre-metamorphosed sibling embryos.     

Developing hydroxypropyl methylcellulose/hydroxypropyl starch blends for use as capsule materials

Blends of hydroxypropyl methylcellulose (HPMC) with up to 70% hydroxypropyl starch (HPS) were developed for use as hard capsule materials. Polyethylene glycol (PEG) was used as both a plasticizer and a compatibilizer in the blends. In order to prepare hard capsules for pharmaceutical application using the well-established method of dipping stainless steel mold pins into solution then drying at certain temperature, equilibrated solutions with higher solids concentration (20%) were investigated and developed. The solutions, films and capsules of the different HPMC/HPS blends were characterized by viscosity, transparency, tensile testing, water contact angle, SEM, as well as FTIR. The results showed that the blend system is immiscible but compatible in certain degree, especially after adding PEG. The hydroxypropylene groups grafted onto both cellulose and starch improved the compatibility between the HPMC and the modified starch. The higher viscosity of starch at lower temperature improved the viscosity balance of the system, which enlarged the operation window for the dipping–drying technique. The PEG increased the transparency and toughness of the various blends. By optimizing temperature and incubation time to control viscosity, capsules of various blends were successfully developed.     

NeuA O-acetylesterase activity is specific for CMP-activated O-acetyl sialic acid in Streptococcus suis serotype 2

Several bacteria causing meningitis, such as Escherichia coli K1, Streptococcus suis, Neisseria meningitidis, and group B Streptococci (GBS), produce sialic acid (Neu5Ac)-containing capsular polysaccharide (CPS). Biosynthesis of the Neu5Ac-containing CPS requires CMP-Neu5Ac as substrate, which is synthesized by CMP-Neu5Ac synthetase from CTP and Neu5Ac. In E. coli or GBS, the NeuA protein encoded by the neuA gene has been known encoding a bifunctional enzyme that possesses both CMP-Neu5Ac synthetase and O-acetylesterase activity. In this report, we found that the S. suis NeuA (SsNeuA) was also a bifunctional CMP-Neu5Ac synthetase/O-acetylesterase. Biochemical analyses revealed that the SsNeuA strictly de-O-acetylated CMP-O-acetyl-Neu5Ac, whereas the E. coli NeuA (EcNeuA) preferentially de-O-acetylated CMP-O-acetyl-Neu5Ac. E. coli devoid of NeuA O-acetylesterase activity was unable to produce capsule and only CMP-Neu5Ac synthetase activity of the EcNeuA or SsNeuA could not restore its ability to produce capsule. These results suggest that the O-acetylesterase is essential for the synthesis of capsular Neu5Ac in E. coli, probably in S. suis and GBS as well. Our findings are key to understanding the biosynthesis of capsular Neu5Ac in E. coli, S. suis and GBS.     

Comparison of Predicted Epimerases and Reductases of the Campylobacter jejuni d-altro- and l-gluco-Heptose Synthesis Pathways

Uniquely modified heptoses found in surface carbohydrates of bacterial pathogens are potential therapeutic targets against such pathogens. Our recent biochemical characterization of the GDP-6-deoxy-d-manno- and GDP-6-deoxy-d-altro-heptose biosynthesis pathways has provided the foundation for elucidation of the more complex l-gluco-heptose synthesis pathway of Campylobacter jejuni strain NCTC 11168. In this work we use GDP-4-keto,6-deoxy-d-lyxo-heptose as a surrogate substrate to characterize three enzymes predicted to be involved in this pathway: WcaG_NCTC (also known as Cj1427), MlghB (Cj1430), and MlghC (Cj1428). We compare them with homologues involved in d-altro-heptose production: WcaG₈₁₁₇₆ (formerly WcaG), DdahB (Cjj1430), and DdahC (Cjj1427). We show that despite high levels of similarity, the enzymes have pathway-specific catalytic activities and substrate specificities. MlghB forms three products via C3 and C5 epimerization activities, whereas its DdahB homologue only had C3 epimerase activity along its cognate pathway. MlghC is specific for the double C3/C5 epimer generated by MlghB and produces l-gluco-heptose via stereospecific C4 reductase activity. In contrast, its homologue DdahC only uses the C3 epimer to yield d-altro-heptose via C4 reduction. Finally, we show that WcaG_NCTC is not necessary for l-gluco-heptose synthesis and does not affect its production by MlghB and MlghC, in contrast to its homologue WcaG₈₁₁₇₆, that has regulatory activity on d-altro-heptose synthesis. These studies expand our fundamental understanding of heptose modification, provide new glycobiology tools to synthesize novel heptose derivatives with biomedical applications, and provide a foundation for the structure function analysis of these enzymes.     

Damage potential of an introduced biological control agent Agonosoma trilineatum (F.) on bellyache bush (Jatropha gossypiifolia L.)

The seed-feeding jewel bug, Agonosoma trilineatum (F.), is an introduced biological control agent for bellyache bush, Jatropha gossypiifolia L. To quantify the damage potential of this agent, shadehouse experiments were conducted with individual bellyache bush plants exposed to a range of jewel bug densities (0, 6 or 24 jewel bugs/plant). The level of abortion of both immature and mature seed capsules and impacts on seed weight and seed viability were recorded in an initial short-term study. The ability of the jewel bug to survive and cause sustained damage was then investigated by measuring seed production, the survival of adults and nymph density across three 6-month cycles. The level of seed capsule abortion caused by the jewel bug was significantly affected by the maturity status of capsules and the density of insects present. Immature capsules were most susceptible and capsule abortion increased with jewel bug density. Similarly, on average, the insects reduced the viability of bellyache bush seeds by 79% and 89% at low and high densities, respectively. However, sustaining jewel bug populations for prolonged periods proved difficult. Adult survival at the end of three 6-month cycles averaged 11% and associated reductions in viable seed production ranged between 55% and 77%. These results suggest that the jewel bug has the potential to reduce the number of viable seeds entering the soil seed bank provided populations can be established and maintained at sufficiently high densities.     

红金消结胶囊联合米非司酮治疗子宫肌瘤的疗效及对血清Ang-2、EGF、NF-κBp65水平的影响

目的:探讨红金消结胶囊联合米非司酮治疗子宫肌瘤的疗效及对血清血管生成素-2(Ang-2)、表皮生长因子(EGF)、核因子-κBp65(NF-κBp65)水平的影响。方法:选择我院2017年5月至2018年5月接诊的103例子宫肌瘤患者,通过随机数表法将其分为观察组53例和对照组50例。对照组给予米非司酮治疗,观察组在对照组基础上联合红金消结胶囊治疗,两组患者在月经期间停药,均连续治疗3个月。比较两组的临床疗效、治疗前后血清Ang-2、EGF、NF-κBp65、卵泡雌激素(FSH)、促黄体生成素(LH)、雌二醇(E2)水平、子宫体积与瘤体情况的变化及不良反应的发生情况。结果:治疗后,观察组临床疗效总有效率为94.34%,显著高于对照组78%,P0.05),血清Ang-2、EGF、NF-κBp65、FSH、LH、E2水平均显著低于对照组(P0.05),子宫体积和子宫肌瘤体积均小于对照组(P0.05)。两组不良反应发生率比较差异无统计学意义(P0.05)。结论:红金消结胶囊联合米非司酮治疗子宫肌瘤的临床疗效显著优于单用米非司酮治疗,其可更显著改善患者性激素水平,缩小子宫和子宫肌瘤的体积,这可能与降低血清Ang-2、EGF、NF-κBp65水平有关。     

复方谷氨酰胺联合双歧杆菌三联活菌胶囊治疗腹泻型肠易激综合征患者的临床疗效

摘要 目的：研究复方谷氨酰胺以及双歧杆菌三联活菌胶囊联用治疗腹泻型肠易激综合征患者的临床疗效。方法：选择2016年1月～2020年2月安徽省濉溪县医院收治的81例腹泻型肠易激综合征患者,将其随机分为两组。对照组41例患者仅口服420 mg的双歧杆菌三联活菌胶囊,每天3次;观察组40例患者加用500 mg的复方谷氨酰胺,每天3次。检测两组治疗前后的血清内毒素、二胺氧化酶活性及D-乳酸水平;血清白介素-6(Interleukin -6,IL-6)、肿瘤坏死因子-α(Tumor necrosis factor alpha,TNF-α)、白介素-8(Interleukin -8,IL-8)、高敏C反应蛋白(High sensitive C reactive protein,hs-CRP)水平;血浆生长抑素和血管活性肠肽水平并比较治疗后临床疗效及治疗过程中不良反应的发生情况。结果：治疗后,观察组的有效率为97.5%,明显高于对照组(75.61%,P<0.05);两组的血清内毒素、二胺氧化酶活性及D-乳酸、IL-6、TNF-α、IL-8、hs-CRP水平、血浆生长抑素和血管活性肠肽水平均较治疗前明显降低(P<0.05),且观察组以上指标均明显低于对照组(P<0.05)。观察组治疗期间的有2例嗜睡、头晕、乏力不适,发生率为5.00 %,对照组有2例头晕,1例头痛、口干,发生率为7.32 %,两组对比无统计学意义（P>0.05）。结论：复方谷氨酰胺联合双歧杆菌三联活菌胶囊治疗腹泻型肠易激综合征患者的临床效果明显优于单用双歧杆菌三联活菌胶囊治疗,其可有效修复肠黏膜屏障损伤,可能与其减轻炎症反应并改善胃肠激素水平有关。     

Assembled capsules transportation driven by motor proteins

An active biomimetic system by integrating kinesin motor, microtubule, and man-made biomimetic microcapsule has been constructed. Biomimetic microcapsules were fabricated by using the layer-by-layer technique and could serve as cargos in this active biomimetic system. Both of the hollow and filled capsules as cargos can be transported by kinesin motors along microtubules. It may help to create kinesin-powered complex hybrid micro- and nanodevices.