Artificial yarn muscles show great potential in applications requiring low-energy consumption while maintaining high performance. However, conventional designs have been limited by weak ion-yarn muscle interactions an...Artificial yarn muscles show great potential in applications requiring low-energy consumption while maintaining high performance. However, conventional designs have been limited by weak ion-yarn muscle interactions and inefficient “rocking-chair” ion migration. To address these limitations, we present an electrochemical artificial yarn muscle design driven by a dual-ion co-regulation system. By utilizing two reaction channels, this system shortens ion migration pathways, leading to faster and more efficient actuation. During the charging/discharging process, PF_6~- ions react with carbon nanotube yarn, while Li~+ ions react with an Al foil. The intercalation reaction between PF_6~- and collapsed carbon nanotubes allows the yarn muscle to achieve an energy-free high-tension catch state. The dual-ion coordinated yarn muscles exhibit superior contractile stroke, maximum contractile rate, and maximum power densities, exceeding those of “rocking-chair” type ion migration yarn muscles. The dual-ion co-regulation system enhances the ion migration rate during actuation, resulting in improved performance. Moreover, the yarn muscles can withstand high levels of isometric stress, displaying a stress of 61 times that of skeletal muscles and 8 times that of “rocking-chair” type yarn muscles at higher frequencies. This technology holds significant potential for various applications, including prosthetics and robotics.展开更多
Effects of hexametazidine [1,4-di(2,3,4-trimethoxybenzyl)piperazine] on the physiological properties of guinea-pig papillary muscles were investigated. Hexametazidine possesses a concentration-dependent negative inotr...Effects of hexametazidine [1,4-di(2,3,4-trimethoxybenzyl)piperazine] on the physiological properties of guinea-pig papillary muscles were investigated. Hexametazidine possesses a concentration-dependent negative inotropic effect (IC_(50)=81.8±16.9μmol/L).The effect of hexametazidine(30.8μmol/L)was antago- nized completely by increasing the concentration of Ca^(2+)from 1.8 to 5.4mmol/L. Hexametazidine(30.8μmol/L)increased the threshold concentration of adrenaline for inducing the automaticity of the muscles from 3.95±1.80 to 6.67±4.84μmol/L (P<0.05).It prolonged the functional refractory period from 218±14 to 254±20ms (P<0.05)at the concentration of 61.6μmol/L.Hexametazidine(6.2μmol/L)antago- nized the positive inotropic effect of isoprenaline competitively and of histamine non-competitively(pA 2 and pD2′ values were 5.45 and 4.13, respectively).展开更多
Objective The present in vivo study was undertaken to determine whether matrine,a kind of traditional Chinese medicinal alkaloid,would relax the isolated guinea pig aortic smooth muscles,if so,to investigate the mecha...Objective The present in vivo study was undertaken to determine whether matrine,a kind of traditional Chinese medicinal alkaloid,would relax the isolated guinea pig aortic smooth muscles,if so,to investigate the mechanism involved.Methods The concentration-dependent relaxation response to matrine was studied in phenylephrine or potassium chloride precontracted guinea pig aortic rings.Results Matrine(1×10-4 M-3.3×10-3 M)relaxed the endothelium denuded aortic rings precontracted submaximally with phenylephrine,in a concentration-dependent manner,and it's preincubation(3.3×10-3 M)produced a significant rightward shift in the phenylephrine dose-response curve,but had no effects on the potassium chloride-induced contraction.The anticontractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide(10-5 M),the non-selective K+ channel blocker tetraethylammonium(10-3 M),as well as the β-antagonist propranolol(10-5 M).In either "normal" or "Ca2+-free" bathing medium,the phenylephrine-induced contraction was attenuated by matrine(3.3×10-3 M),indicating the vasorelaxation was due to inhibit of intracellular and extracellular Ca2+ mobilization.Conclusions The results obtained clearly demonstrated that matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with both the release of intracellular Ca2+ and the influx of extracellular Ca2+.展开更多
The effects of iodium-heterocyclic compound（3,6-di-[dimethytamino]-dibcnzopyrodoniun formate,IHC-64）on the action potentials and contractile force of the isolatedguinca pig papillary muscles were investigatad.50 μm...The effects of iodium-heterocyclic compound（3,6-di-[dimethytamino]-dibcnzopyrodoniun formate,IHC-64）on the action potentials and contractile force of the isolatedguinca pig papillary muscles were investigatad.50 μmol/L IHC-64 only inhibited contractile forceand had no effect on APA,dv/dt max,APD<sub>5</sub>0 and APD<sub>9</sub>0 of fast action potentials in Tyrode’s so-lution.All of these parametres were depressed by further increasing concentration of IHC-64.InK-rich Tyrodc’s solution,the depressive action of IHC-64 on slow action potentials andcontractile force could be antagonized by incrcased extracellular calcium.These results suggesr thatIHC-64 inhibit not only slow calcium influx but also fast sodium influx,and it may.（?）new calci-urn channd blockcr.展开更多
The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the...The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the scanning electron microscope(SEM) and the light microscope by phosphotungstic acid haematoxylin(PTAH) stain. The results showed that the striations of muscle were blurred within 4 h, but they became apparent from 6 h to 24 h after death. The authors suggest that this phenomenon be associated with the increased resistance of muscle against the postmortal changes. The observations by scanning electron microscopy and light microscopy have revealed that the muscles do contract in the process of rigor mortis because the distance between two Z lines shortens and the I band narrows, compared with those in anaesthetised animals. The basic biochemical process for the formation of rigor mortis is the same as that of muscle contraction except that the former happens postmortem and the latter antemortem.展开更多
Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (c...Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (composed of 3 different types of HHK material with varied degradation speed) after musclectomy were divided into 3 groups (2 in each group) to observe the degradation of the material at 1, 3, 6weeks after operation. Another rabbit without operation was used as the control group. The degradation of HHK was observed with light microscopy, histochemistry of ubiquitin and electron microscopy. Results:Light microscopy showed that human hair cuticles fell off from the HHK material and emerged, and the macrophagocytes and multinucleate giant cells were attached onto the surface of the material, which became homogeneous at the first postoperative week. The HHK scaffold material was degraded into particles that was phagocytosed by macrophagocytes and multinucleate giant cells at the third week. Ubiquitin enzymatic histochemistry showed that the macrophagocytes and the multinucleate giant cells were positive at the first week. Under electron microscope, HHK scaffold material was degraded into particles, and at the sixth week,part of HHK scaffold material was further degraded. Conclusion: Large mass of the HHK scaffold material is degraded via ubiquitin system, and the resultant particles are phagocytosed and degraded with the cooperation of lysosome and ubiquitin.展开更多
Objective:To observe the dynamic changes of interleukin--6(IL--6) and its effects on catabolism ofthe skeletal muscle protein in the early stage after scalding. Methods: After a model of Balb/C mice inflictedwith 18%-...Objective:To observe the dynamic changes of interleukin--6(IL--6) and its effects on catabolism ofthe skeletal muscle protein in the early stage after scalding. Methods: After a model of Balb/C mice inflictedwith 18%-- 20% TBSA full--thickness skin scald on the back and one hindleg was established, the proteincatabolic rate (TNR) and the level of 11.M6 in soleus muscle and serum were determined and the effects of IL6 on TNR of normal mice and those of 11.--6 antiserurn on TNR of the scalded mice wee observed during thefirst week after scalding. Results: The level of IL--6 was significantly increased and maintained during thefirst three days. TNR of the scalded leg was elevated to the peak on the 3rd day and then decreased graduallywhile that of the unscalded leg was increased only on the 2nd day after scalding. TNR was significantlyincreased when IL--6 was injected to the normal mice and IL--6 antiserum could significantly inhibit the. increased TNR of the scalded mice when it was injected intraperitoneally. Conclusion: The increase of IL--6 isrelated with local inflammatory response in the early stage after scalding and the high level of IL--6 canincrease the catabolic rate of muscle protein.展开更多
Obesity is associated with skeletal muscle mass loss and physical dysfunction.Krill oil(KO)has been shown to be beneficial in human health.However,the effect of KO on obesity-induced skeletal muscle atrophy is still u...Obesity is associated with skeletal muscle mass loss and physical dysfunction.Krill oil(KO)has been shown to be beneficial in human health.However,the effect of KO on obesity-induced skeletal muscle atrophy is still unclear.In this study,the male C57BL/6J mice were fed a high-fat diet(HFD)for 12 weeks to induce obesity,and then were intragastric administration with 400 mg/kg bw KO for an additional 6 weeks.The results showed that KO treatment reduced body weight,fat accumulation and serum pro-inflammatory cytokines in HFD-induced obese mice.Importantly,KO treatment attenuated skeletal muscle atrophy in HFD-fed mice,as evidenced by preserving skeletal muscle mass,average myofiber cross-sectional area and grip strength.KO administration also mitigated obesity-induced ectopic lipid deposition and inflammatory response in skeletal muscle.Additionally,KO treatment inhibited the transcriptional activities of nuclear factor-κB(NF-κB)p65 and forkhead box O 3a(FoxO3a),and then down-regulated muscle atrophy F-box(MAFbx)and muscle-specific RING finger protein 1(MuRF1)protein levels in skeletal muscle from HFD-fed mice.KO administration also improved obesity-induced impaired muscle protein synthesis via activating PI3K/Akt pathway.Furthermore,KO treatment enhanced muscle mitochondrial biogenesis in HFD-induced obese mice via activating PGC-1αpathway.Collectively,KO might be developed as a potential nutritional supplement for the prevention and treatment of obesity-induced skeletal muscle atrophy.展开更多
Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as ...Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as a promising alternative.In this study,we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone)integrated with collagen and Ti_(3)C_(2)T_(x)MXene nanoparticles(NPs)(PCM matrices),and explored their myogenic potential for skeletal muscle tissue regeneration.The PCM matrices demonstrated favorable physicochemical properties,including structural uniformity,alignment,microporosity,and hydrophilicity.In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts.Moreover,in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury.Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices,leading to elevated intracellular Ca^(2+)levels in myoblasts through the activation of inducible nitric oxide synthase(i NOS)and serum/glucocorticoid regulated kinase 1(SGK1),ultimately promoting myogenic differentiation via the m TOR-AKT pathway.Additionally,upregulated i NOS and increased NO–contributed to myoblast proliferation and fiber fusion,thereby facilitating overall myoblast maturation.These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.展开更多
BACKGROUND: Early identification of patients requiring ventilator support will be beneficial for the outcomes of botulism. The present study aimed to establish a new scoring system to predict mechanical ventilation(MV...BACKGROUND: Early identification of patients requiring ventilator support will be beneficial for the outcomes of botulism. The present study aimed to establish a new scoring system to predict mechanical ventilation(MV) for botulism patients.METHODS: A single-center retrospective study was conducted to identify risk factors associated with MV in botulism patients from 2007 to 2022. Univariate analysis and multivariate logistic regression analysis were used to screen out risk factors for constructing a prognostic scoring system. The area under the receiver operating characteristic(ROC) curve was calculated.RESULTS: A total of 153 patients with botulism(66 males and 87 females, with an average age of 43 years) were included. Of these, 49 patients(32.0%) required MV, including 21(13.7%) with invasive ventilation and 28(18.3%) with non-invasive ventilation. Multivariate analysis revealed that botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement were independent risk factors for MV. These risk factors were incorporated into a multivariate logistic regression analysis to establish a prognostic scoring system. Each risk factor was scored by allocating a weight based on its regression coefficient and rounded to whole numbers for practical utilization([botulinum toxin type A: 1], [pneumonia: 2], [incubation period ≤1 day: 2], [hypoxia <90%: 2], [severity of muscle involvement: grade Ⅱ, 3;gradeⅢ, 7;grade IV, 11]). The scoring system achieved an area under the ROC curve of 0.82(95% CI 0.75–0.89, P<0.001). At the optimal threshold of 9, the scoring system achieved a sensitivity of 83.7% and a specificity of 70.2%.CONCLUSION: Our study identified botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement as independent risk factors for MV in botulism patients. A score ≥9 in our scoring system is associated with a higher likelihood of requiring MV in botulism patients. This scoring system needs to be validated externally before it can be applied in clinical settings.展开更多
Our previous research studies have shown that Veratrilla baillonii Franch,a food supplement used by ethnic minorities in Southwest China,has multiple pharmacological activities,such as detoxification,antiinflammatory,...Our previous research studies have shown that Veratrilla baillonii Franch,a food supplement used by ethnic minorities in Southwest China,has multiple pharmacological activities,such as detoxification,antiinflammatory,antioxidant,and anti-insulin resistance.However,the detailed signal pathways for its salutary effect on damages in multiple organs due to type 2 diabetes mellitus(T2DM)remains unclear.The current study is to evaluate the therapeutic effects of V.baillonii on T2DM rats and to explore the underlying mechanisms.The T2DM rat model was successfully established by a high-sugar and high-fat diet(HFD)combination with intraperitoneal injection of a small dose of streptozotocin(STZ,35 mg/kg).Biochemical analysis and histopatholgical examinations were conducted to evaluate the anti-diabetic potential of water extracts of V.baillonii(WVBF).The results showed that the WVBF treatment can improve hyperglycemia and insulin resistance,ameliorate the liver,kidney and pancreas injuries via decreasing inflammatory cytokines such as IL-6 and TNF-α,and oxidative damages.Further investigation suggested that WVBF modulates the signal transductions of the IRS1/PI3K/AKT/GLUT4 and AMPK pathways.These findings demonstrate potentials of WVBF in the treatment of T2DM and possible mechanisms for its hepatoprotective activities.展开更多
Restenosis is a common complication following coronary angioplasty.The traditional use of seaweeds for health benefits has increasingly been explored,however few studies exist reporting its protective effects on the d...Restenosis is a common complication following coronary angioplasty.The traditional use of seaweeds for health benefits has increasingly been explored,however few studies exist reporting its protective effects on the development of restenosis and gut dysbiosis.The aim of this study was to investigate the potential of seaweed extracts(SE) of Ascophyllum nodosum and Fucus vesiculosus in inhibiting intimal hyperplasia in a rat model of restenosis and its underlying mechanisms in macrophages and vascular smooth muscle cells(vSMCs).16S rRNA sequencing was done to investigate the regulatory effect of SE on the gut microbiome of injured rats.As indicated by the results,SE significantly inhibited the progression of intimal hyperplasia in vivo,attenuated inflammation in macrophages and could inhibit the proliferation,dedifferentiation and migration of vSMCs.It was observed through immunoblotting assays that treatment with SE significantly upregulated PTEN expression in macrophages and inhibited the upregulation of PI3K and AKT expression in vSMCs.Meanwhile,according to the 16S rRNA gene sequencing analysis,supplementation with SE modulated gut microbiota composition in injured rats.In conclusion,SE could ameliorate intimal hyperplasia by inhibiting inflammation and vSMCs proliferation through the regulation of the PTEN/PI3K/AKT pathway and modulating the gut microbiome.展开更多
网格生成所需人力资源和工作时间在整个流场数值模拟周期中占比较高,是计算流体力学应用软件的瓶颈。大量文献提供了结构网格质量特性对差分格式计算结果有影响的算例,但是很少给出正交性和光滑性影响误差的机理分析。分析了MUSCL和WEN...网格生成所需人力资源和工作时间在整个流场数值模拟周期中占比较高,是计算流体力学应用软件的瓶颈。大量文献提供了结构网格质量特性对差分格式计算结果有影响的算例,但是很少给出正交性和光滑性影响误差的机理分析。分析了MUSCL和WENO差分格式在非均匀网格上产生的几何诱导误差,发现正交性和误差之间并无直接关联,有影响的几何参数是相邻网格的偏转角。理论推导证明,误差主要源自控制方程和差分格式,提高网格质量特性能够明显减小几何诱导误差,但是不能完全消除。近年来作者致力于改进算法,先后提出离散等价方程及其等价离散准则(discrete equivalence equation and its discrete rule,DEER)和非结构有限差分法。通过对自由流保持和线性流保持等算例的模拟,利用改进的算法在质量较差的网格上也能得到较好的计算结果。展开更多
The article discusses a method that simultaneously determination of nitrofuran metabolites in chicken muscle by UPLC-MS/MS.The nitrofuran metabolites were derived and extracted from the chicken muscle,and detected by ...The article discusses a method that simultaneously determination of nitrofuran metabolites in chicken muscle by UPLC-MS/MS.The nitrofuran metabolites were derived and extracted from the chicken muscle,and detected by electrospray ionization and in the positive ion mode.It has higher sensitivity and shorter analytical time.This method is more suitable for determination of nitrofuran metabolites in the chicken muscle.展开更多
A method for simultaneous analysis of five tetracyclines(tetracycline,oxytetracycline,chlortetracycline,doxycycline and minocycline) in bovine muscle was developed by UPLC-MS/MS.The sample was extracted with Mcllvaine...A method for simultaneous analysis of five tetracyclines(tetracycline,oxytetracycline,chlortetracycline,doxycycline and minocycline) in bovine muscle was developed by UPLC-MS/MS.The sample was extracted with Mcllvaine buffer-EDTA(pH 4.0) and cleaned up by solid-phase extraction on Oasis HLB cartridges.Analytes were separated by UPLC,and detected by mass spectrum with MRM mode.The calibration curves showed good linear relations in the concentration range of 1-100 μg·L-1(r>0.994) for five tetracyclines.The average recoveries at the spiked concentration levels of 1,20,50 and 100 μg·kg-1 were range of 68%-105% and the RSD were less than 34.1%.The LOD of the method was 0.05 μg·kg-1 for five tetracyclines.展开更多
基金financial support obtained from the National Key Research and Development Program of China (2020YFB1312900)the National Natural Science Foundation of China (21975281)+1 种基金Key Research Project of Zhejiang lab (No. K2022NB0AC04)Jiangxi Double Thousand Talent Program (No. jxsq2020101008)。
文摘Artificial yarn muscles show great potential in applications requiring low-energy consumption while maintaining high performance. However, conventional designs have been limited by weak ion-yarn muscle interactions and inefficient “rocking-chair” ion migration. To address these limitations, we present an electrochemical artificial yarn muscle design driven by a dual-ion co-regulation system. By utilizing two reaction channels, this system shortens ion migration pathways, leading to faster and more efficient actuation. During the charging/discharging process, PF_6~- ions react with carbon nanotube yarn, while Li~+ ions react with an Al foil. The intercalation reaction between PF_6~- and collapsed carbon nanotubes allows the yarn muscle to achieve an energy-free high-tension catch state. The dual-ion coordinated yarn muscles exhibit superior contractile stroke, maximum contractile rate, and maximum power densities, exceeding those of “rocking-chair” type ion migration yarn muscles. The dual-ion co-regulation system enhances the ion migration rate during actuation, resulting in improved performance. Moreover, the yarn muscles can withstand high levels of isometric stress, displaying a stress of 61 times that of skeletal muscles and 8 times that of “rocking-chair” type yarn muscles at higher frequencies. This technology holds significant potential for various applications, including prosthetics and robotics.
文摘Effects of hexametazidine [1,4-di(2,3,4-trimethoxybenzyl)piperazine] on the physiological properties of guinea-pig papillary muscles were investigated. Hexametazidine possesses a concentration-dependent negative inotropic effect (IC_(50)=81.8±16.9μmol/L).The effect of hexametazidine(30.8μmol/L)was antago- nized completely by increasing the concentration of Ca^(2+)from 1.8 to 5.4mmol/L. Hexametazidine(30.8μmol/L)increased the threshold concentration of adrenaline for inducing the automaticity of the muscles from 3.95±1.80 to 6.67±4.84μmol/L (P<0.05).It prolonged the functional refractory period from 218±14 to 254±20ms (P<0.05)at the concentration of 61.6μmol/L.Hexametazidine(6.2μmol/L)antago- nized the positive inotropic effect of isoprenaline competitively and of histamine non-competitively(pA 2 and pD2′ values were 5.45 and 4.13, respectively).
文摘Objective The present in vivo study was undertaken to determine whether matrine,a kind of traditional Chinese medicinal alkaloid,would relax the isolated guinea pig aortic smooth muscles,if so,to investigate the mechanism involved.Methods The concentration-dependent relaxation response to matrine was studied in phenylephrine or potassium chloride precontracted guinea pig aortic rings.Results Matrine(1×10-4 M-3.3×10-3 M)relaxed the endothelium denuded aortic rings precontracted submaximally with phenylephrine,in a concentration-dependent manner,and it's preincubation(3.3×10-3 M)produced a significant rightward shift in the phenylephrine dose-response curve,but had no effects on the potassium chloride-induced contraction.The anticontractile effect of matrine was not reduced by the highly selective ATP-dependent K+ channel blocker glibenclamide(10-5 M),the non-selective K+ channel blocker tetraethylammonium(10-3 M),as well as the β-antagonist propranolol(10-5 M).In either "normal" or "Ca2+-free" bathing medium,the phenylephrine-induced contraction was attenuated by matrine(3.3×10-3 M),indicating the vasorelaxation was due to inhibit of intracellular and extracellular Ca2+ mobilization.Conclusions The results obtained clearly demonstrated that matrine inhibits phenylephrine-induced contractions by inhibiting activation of α-adrenoceptor and interfering with both the release of intracellular Ca2+ and the influx of extracellular Ca2+.
文摘The effects of iodium-heterocyclic compound（3,6-di-[dimethytamino]-dibcnzopyrodoniun formate,IHC-64）on the action potentials and contractile force of the isolatedguinca pig papillary muscles were investigatad.50 μmol/L IHC-64 only inhibited contractile forceand had no effect on APA,dv/dt max,APD<sub>5</sub>0 and APD<sub>9</sub>0 of fast action potentials in Tyrode’s so-lution.All of these parametres were depressed by further increasing concentration of IHC-64.InK-rich Tyrodc’s solution,the depressive action of IHC-64 on slow action potentials andcontractile force could be antagonized by incrcased extracellular calcium.These results suggesr thatIHC-64 inhibit not only slow calcium influx but also fast sodium influx,and it may.（?）new calci-urn channd blockcr.
文摘The aim of this study was to observe the morphological changes of muscle in the process of rigor mortis. The quadriceps of 40 rats at various postmortem intervals were observed under the scanning electron microscope(SEM) and the light microscope by phosphotungstic acid haematoxylin(PTAH) stain. The results showed that the striations of muscle were blurred within 4 h, but they became apparent from 6 h to 24 h after death. The authors suggest that this phenomenon be associated with the increased resistance of muscle against the postmortal changes. The observations by scanning electron microscopy and light microscopy have revealed that the muscles do contract in the process of rigor mortis because the distance between two Z lines shortens and the I band narrows, compared with those in anaesthetised animals. The basic biochemical process for the formation of rigor mortis is the same as that of muscle contraction except that the former happens postmortem and the latter antemortem.
文摘Objective:To explore the mechanism of the degradation of human hair keratin (HHK) scaffold material implanted in damaged skeletal muscle tissues. Methods: Six New Zealand rabbits with HHK scaffold material implants (composed of 3 different types of HHK material with varied degradation speed) after musclectomy were divided into 3 groups (2 in each group) to observe the degradation of the material at 1, 3, 6weeks after operation. Another rabbit without operation was used as the control group. The degradation of HHK was observed with light microscopy, histochemistry of ubiquitin and electron microscopy. Results:Light microscopy showed that human hair cuticles fell off from the HHK material and emerged, and the macrophagocytes and multinucleate giant cells were attached onto the surface of the material, which became homogeneous at the first postoperative week. The HHK scaffold material was degraded into particles that was phagocytosed by macrophagocytes and multinucleate giant cells at the third week. Ubiquitin enzymatic histochemistry showed that the macrophagocytes and the multinucleate giant cells were positive at the first week. Under electron microscope, HHK scaffold material was degraded into particles, and at the sixth week,part of HHK scaffold material was further degraded. Conclusion: Large mass of the HHK scaffold material is degraded via ubiquitin system, and the resultant particles are phagocytosed and degraded with the cooperation of lysosome and ubiquitin.
文摘Objective:To observe the dynamic changes of interleukin--6(IL--6) and its effects on catabolism ofthe skeletal muscle protein in the early stage after scalding. Methods: After a model of Balb/C mice inflictedwith 18%-- 20% TBSA full--thickness skin scald on the back and one hindleg was established, the proteincatabolic rate (TNR) and the level of 11.M6 in soleus muscle and serum were determined and the effects of IL6 on TNR of normal mice and those of 11.--6 antiserurn on TNR of the scalded mice wee observed during thefirst week after scalding. Results: The level of IL--6 was significantly increased and maintained during thefirst three days. TNR of the scalded leg was elevated to the peak on the 3rd day and then decreased graduallywhile that of the unscalded leg was increased only on the 2nd day after scalding. TNR was significantlyincreased when IL--6 was injected to the normal mice and IL--6 antiserum could significantly inhibit the. increased TNR of the scalded mice when it was injected intraperitoneally. Conclusion: The increase of IL--6 isrelated with local inflammatory response in the early stage after scalding and the high level of IL--6 canincrease the catabolic rate of muscle protein.
基金supported by the National Natural Science Foundation of China(82003447,32202023)the Natural Science Foundation of Shandong Province(ZR2021QC177)the Young Scholars Program of Shandong University(2018WLJH33,2018WLJH34)。
文摘Obesity is associated with skeletal muscle mass loss and physical dysfunction.Krill oil(KO)has been shown to be beneficial in human health.However,the effect of KO on obesity-induced skeletal muscle atrophy is still unclear.In this study,the male C57BL/6J mice were fed a high-fat diet(HFD)for 12 weeks to induce obesity,and then were intragastric administration with 400 mg/kg bw KO for an additional 6 weeks.The results showed that KO treatment reduced body weight,fat accumulation and serum pro-inflammatory cytokines in HFD-induced obese mice.Importantly,KO treatment attenuated skeletal muscle atrophy in HFD-fed mice,as evidenced by preserving skeletal muscle mass,average myofiber cross-sectional area and grip strength.KO administration also mitigated obesity-induced ectopic lipid deposition and inflammatory response in skeletal muscle.Additionally,KO treatment inhibited the transcriptional activities of nuclear factor-κB(NF-κB)p65 and forkhead box O 3a(FoxO3a),and then down-regulated muscle atrophy F-box(MAFbx)and muscle-specific RING finger protein 1(MuRF1)protein levels in skeletal muscle from HFD-fed mice.KO administration also improved obesity-induced impaired muscle protein synthesis via activating PI3K/Akt pathway.Furthermore,KO treatment enhanced muscle mitochondrial biogenesis in HFD-induced obese mice via activating PGC-1αpathway.Collectively,KO might be developed as a potential nutritional supplement for the prevention and treatment of obesity-induced skeletal muscle atrophy.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korean Government(the Ministry of Science and ICT(MSIT))(No.2021R1A2C2006013)the Bio&Medical Technology Development Program of the NRF funded by the Korean government(MSIT)(No.RS-2023-00223591)the Korea Medical Device Development Fund grant funded by the Korean government(the MSIT,the MOTIE,the Ministry of Health and Welfare,the Ministry of Food and Drug Safety)(NTIS Number:9991006781,KMDF_PR_(2)0200901_0108)。
文摘Current therapeutic approaches for volumetric muscle loss(VML)face challenges due to limited graft availability and insufficient bioactivities.To overcome these limitations,tissue-engineered scaffolds have emerged as a promising alternative.In this study,we developed aligned ternary nanofibrous matrices comprised of poly(lactide-co-ε-caprolactone)integrated with collagen and Ti_(3)C_(2)T_(x)MXene nanoparticles(NPs)(PCM matrices),and explored their myogenic potential for skeletal muscle tissue regeneration.The PCM matrices demonstrated favorable physicochemical properties,including structural uniformity,alignment,microporosity,and hydrophilicity.In vitro assays revealed that the PCM matrices promoted cellular behaviors and myogenic differentiation of C2C12 myoblasts.Moreover,in vivo experiments demonstrated enhanced muscle remodeling and recovery in mice treated with PCM matrices following VML injury.Mechanistic insights from next-generation sequencing revealed that MXene NPs facilitated protein and ion availability within PCM matrices,leading to elevated intracellular Ca^(2+)levels in myoblasts through the activation of inducible nitric oxide synthase(i NOS)and serum/glucocorticoid regulated kinase 1(SGK1),ultimately promoting myogenic differentiation via the m TOR-AKT pathway.Additionally,upregulated i NOS and increased NO–contributed to myoblast proliferation and fiber fusion,thereby facilitating overall myoblast maturation.These findings underscore the potential of MXene NPs loaded within highly aligned matrices as therapeutic agents to promote skeletal muscle tissue recovery.
基金funded by the Medical Science Research Project of Hebei Provincial Health and Health Commission(20221073).
文摘BACKGROUND: Early identification of patients requiring ventilator support will be beneficial for the outcomes of botulism. The present study aimed to establish a new scoring system to predict mechanical ventilation(MV) for botulism patients.METHODS: A single-center retrospective study was conducted to identify risk factors associated with MV in botulism patients from 2007 to 2022. Univariate analysis and multivariate logistic regression analysis were used to screen out risk factors for constructing a prognostic scoring system. The area under the receiver operating characteristic(ROC) curve was calculated.RESULTS: A total of 153 patients with botulism(66 males and 87 females, with an average age of 43 years) were included. Of these, 49 patients(32.0%) required MV, including 21(13.7%) with invasive ventilation and 28(18.3%) with non-invasive ventilation. Multivariate analysis revealed that botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement were independent risk factors for MV. These risk factors were incorporated into a multivariate logistic regression analysis to establish a prognostic scoring system. Each risk factor was scored by allocating a weight based on its regression coefficient and rounded to whole numbers for practical utilization([botulinum toxin type A: 1], [pneumonia: 2], [incubation period ≤1 day: 2], [hypoxia <90%: 2], [severity of muscle involvement: grade Ⅱ, 3;gradeⅢ, 7;grade IV, 11]). The scoring system achieved an area under the ROC curve of 0.82(95% CI 0.75–0.89, P<0.001). At the optimal threshold of 9, the scoring system achieved a sensitivity of 83.7% and a specificity of 70.2%.CONCLUSION: Our study identified botulinum toxin type, pneumonia, incubation period, degree of hypoxia, and severity of muscle involvement as independent risk factors for MV in botulism patients. A score ≥9 in our scoring system is associated with a higher likelihood of requiring MV in botulism patients. This scoring system needs to be validated externally before it can be applied in clinical settings.
基金supported by grants from the National Natural Science Foundation of China (81873090)Support Innovation and Development of Enterprise Technology Projects in Hubei Province (2021BLB174)the modern transmission and innovation research team of Traditional Chinese Medicine,South Central Minzu University。
文摘Our previous research studies have shown that Veratrilla baillonii Franch,a food supplement used by ethnic minorities in Southwest China,has multiple pharmacological activities,such as detoxification,antiinflammatory,antioxidant,and anti-insulin resistance.However,the detailed signal pathways for its salutary effect on damages in multiple organs due to type 2 diabetes mellitus(T2DM)remains unclear.The current study is to evaluate the therapeutic effects of V.baillonii on T2DM rats and to explore the underlying mechanisms.The T2DM rat model was successfully established by a high-sugar and high-fat diet(HFD)combination with intraperitoneal injection of a small dose of streptozotocin(STZ,35 mg/kg).Biochemical analysis and histopatholgical examinations were conducted to evaluate the anti-diabetic potential of water extracts of V.baillonii(WVBF).The results showed that the WVBF treatment can improve hyperglycemia and insulin resistance,ameliorate the liver,kidney and pancreas injuries via decreasing inflammatory cytokines such as IL-6 and TNF-α,and oxidative damages.Further investigation suggested that WVBF modulates the signal transductions of the IRS1/PI3K/AKT/GLUT4 and AMPK pathways.These findings demonstrate potentials of WVBF in the treatment of T2DM and possible mechanisms for its hepatoprotective activities.
基金supported by the research grants from the Ministry of Science and Technology of Taiwan (MOST108-2320B-038-040-MY3 and MOST 111-2320-B-038-049)the National Science and Technology Council (NSTC111-2320-B-038-049)。
文摘Restenosis is a common complication following coronary angioplasty.The traditional use of seaweeds for health benefits has increasingly been explored,however few studies exist reporting its protective effects on the development of restenosis and gut dysbiosis.The aim of this study was to investigate the potential of seaweed extracts(SE) of Ascophyllum nodosum and Fucus vesiculosus in inhibiting intimal hyperplasia in a rat model of restenosis and its underlying mechanisms in macrophages and vascular smooth muscle cells(vSMCs).16S rRNA sequencing was done to investigate the regulatory effect of SE on the gut microbiome of injured rats.As indicated by the results,SE significantly inhibited the progression of intimal hyperplasia in vivo,attenuated inflammation in macrophages and could inhibit the proliferation,dedifferentiation and migration of vSMCs.It was observed through immunoblotting assays that treatment with SE significantly upregulated PTEN expression in macrophages and inhibited the upregulation of PI3K and AKT expression in vSMCs.Meanwhile,according to the 16S rRNA gene sequencing analysis,supplementation with SE modulated gut microbiota composition in injured rats.In conclusion,SE could ameliorate intimal hyperplasia by inhibiting inflammation and vSMCs proliferation through the regulation of the PTEN/PI3K/AKT pathway and modulating the gut microbiome.
文摘网格生成所需人力资源和工作时间在整个流场数值模拟周期中占比较高,是计算流体力学应用软件的瓶颈。大量文献提供了结构网格质量特性对差分格式计算结果有影响的算例,但是很少给出正交性和光滑性影响误差的机理分析。分析了MUSCL和WENO差分格式在非均匀网格上产生的几何诱导误差,发现正交性和误差之间并无直接关联,有影响的几何参数是相邻网格的偏转角。理论推导证明,误差主要源自控制方程和差分格式,提高网格质量特性能够明显减小几何诱导误差,但是不能完全消除。近年来作者致力于改进算法,先后提出离散等价方程及其等价离散准则(discrete equivalence equation and its discrete rule,DEER)和非结构有限差分法。通过对自由流保持和线性流保持等算例的模拟,利用改进的算法在质量较差的网格上也能得到较好的计算结果。
文摘The article discusses a method that simultaneously determination of nitrofuran metabolites in chicken muscle by UPLC-MS/MS.The nitrofuran metabolites were derived and extracted from the chicken muscle,and detected by electrospray ionization and in the positive ion mode.It has higher sensitivity and shorter analytical time.This method is more suitable for determination of nitrofuran metabolites in the chicken muscle.
文摘A method for simultaneous analysis of five tetracyclines(tetracycline,oxytetracycline,chlortetracycline,doxycycline and minocycline) in bovine muscle was developed by UPLC-MS/MS.The sample was extracted with Mcllvaine buffer-EDTA(pH 4.0) and cleaned up by solid-phase extraction on Oasis HLB cartridges.Analytes were separated by UPLC,and detected by mass spectrum with MRM mode.The calibration curves showed good linear relations in the concentration range of 1-100 μg·L-1(r>0.994) for five tetracyclines.The average recoveries at the spiked concentration levels of 1,20,50 and 100 μg·kg-1 were range of 68%-105% and the RSD were less than 34.1%.The LOD of the method was 0.05 μg·kg-1 for five tetracyclines.
