A glass micropipette vacuum technique of cerebrospinal fluid sampling in C57BL/6 mice / 生理学报

The purpose of this study was to establish a suitable method for extracting cerebrospinal fluid (CSF) from C57BL/6 mice. A patch clamp electrode puller was used to draw a glass micropipette, and a brain stereotaxic device was used to fix the mouse's head at an angle of 135° from the body. Under a stereoscopic microscope, the skin and muscle tissue on the back of the mouse's head were separated, and the dura mater at the cerebellomedullary cistern was exposed. The glass micropipette (with an angle of 20° to 30° from the dura mater) was used to puncture at a point 1 mm inboard of Y-shaped dorsal vertebral artery for CSF sampling. After the first extraction, the glass micropipette was connected with a 1 mL sterile syringe to form a negative pressure device for the second extraction. The results showed that the successful rate of CSF extraction was 83.33% (30/36). Average CSF extraction amount was (7.16 ± 0.43) μL per mouse. In addition, C57BL/6 mice were given intranasally ferric ammonium citrate (FAC) to establish a model of brain iron accumulation, and the CSF extraction technique established in the present study was used for sampling. The results showed that iron content in the CSF from the normal saline control group was not detected, while the iron content in the CSF from FAC-treated group was (76.24 ± 38.53) μmol/L, and the difference was significant. These results suggest that glass micropipette vacuum technique of CSF sampling established in the present study has the advantages of simplicity, high success rate, large extraction volume, and low bleeding rate, and is suitable for the research on C57BL/6 mouse neurological disease models.

Research progress in pharmacokinetics/pharmacodynamics and therapeutic drug monitoring of biapenem / 中国药房

Biapenem is a carbapenem antibiotic， and can be used for the treatment of sepsis， pneumonia， lung abscess， chronic respiratory lesions secondary infection， complex urinary tract infection and pyelonephritis， etc. This article reviewed the studies on the pharmacokinetics， pharmacodynamics and therapeutic drug monitoring （TDM） of biapenem. The pharmacokinetic parameters of biapenem are not significantly different in healthy subjects， and there is no accumulation after multiple doses of biapenem. However， there are large differences in pharmacokinetic parameters in patients with severe disease and patients with abnormal renal function compared with healthy subjects， which leads to conventional treatment regimens not achieving the desired outcome. In terms of pharmacodynamics， biapenem can improve the rate of reaching the target value by increasing the frequency of administration and prolonging the infusion time. For patients with anuria in end-stage renal disease， dosing intervals can be extended to avoid drug accumulation. However, for patients with severe infection, a daily dose of 1.2 g still can not control infections caused by Acinetobacter baumannii or Pseudomonas aeruginosa, which limits its use in patients with severe disease. It is recommended to implement TDM in severe patients and patients with abnormal renal function， and explore the best dosing regimen for biapenem in combination with pharmacokinetic models to ensure that the time that the free blood concentration of biapenem remains above minimum inhibitory concentration as a percentage of the time between doses （%fT＞MIC） is within the effective range，so that biapenem can exert a greater efficacy in severe patients and patients with abnormal renal function. For medical institutions that cannot carry out TDM， the efficacy of biapenem can be maximized by increasing the frequency of administration and prolonging the infusion time. For infections caused by P. aeruginosa， A. baumannii and Serratia marcescens with high drug resistance rates， it is recommended to combine or replace other antibiotics.

Investigation and study of the professional identity and its correlation with mentoring function and professional competency among clinical medicine postgraduates / 中华医学教育探索杂志

Objective:To investigate the current status of professional identity among the clinical medical postgraduates and its correlation with mentoring function and professional competency, so as to provide reference for optimizing the training mode of clinical medicine postgraduates.Methods:A questionnaire survey was conducted among 217 academic and professional full-time postgraduates from Batch 2016 to 2018 majoring in clinical medicine in Peking University Health Science Center in 2019. The contents included four aspects: basic information, preliminary questionnaire of professional identity, mentoring function scale and professional competency. SPSS 26.0 was used for t test, one-way ANOVA, Kruskal-Wallis H test, and Pearson correlation analysis to analyze the status of professional identity and its correlation with professional competency and mentoring function. Results:Both professional and academic clinical medicine postgraduates had high scores of the overall level and four factors, and there was no statistical significance in the scores between the two groups ( P >0.05). There were significant differences in the overall level, behavior and appropriateness of professional identity among different grades of professional postgraduates ( P<0.05). Correlation study showed that the professional identity was significantly positively correlated with the total score of professional competency and mentoring function ( P<0.001). Further interview survey showed that the role of supervisor and employment prospects also played an important role in the elevation of professional identity. Conclusion:The overall degree of professional identity of academic and professional postgraduates is good and closely related to professional competency and mentoring function and for professional postgraduates, the overall level of professional identity of senior students is better. It is suggested that besides focusing on their professional competency, it is necessary to further optimize the employment policy of academic postgraduates and the training of tutors for professional postgraduates.

The clinical characteristics of nuclear dense fine speckled pattern in 95 289 patients / 中华内科杂志

To investigate the distribution and clinical significance of nuclear dense fine speckled (DFS) pattern in various diseases. A total of 95 289 patients who received DFS tests at Peking Union Medical College Hospital from January 2019 to December 2020 were included in this study. The results of indirect immunofluorescence assay (IIF) for detection of antinuclear antibody (ANA) were evaluated. The positive rates of ANA and DFS were 39.60% (37 733/95 289) and 1.19% (1 139/95 289) respectively. The positive rate of DFS in ANA-positive patients was 3.02% (1 139/37 733). DFS and ANA positivity were significantly different among different age groups rather than gender. The positivity rate of DFS reached the peak (55.57%, 633/1 139) in young patients between 21-40 years, while positive ANA with negative DFS was mainly observed in patients between 41-60 years (37.26%, 13 636/36 594). Additionally, single ANA-positivity were mainly detected in rheumatology department (59.23%, 18 402/31 066), whereas positive DFS was more common in obstetrics and gynecology department (3.08%, 49/1 593). There were 82.88% (944/1 139) patients with positive DFS diagnosed with non-autoimmune disease (non-AID), and 19.49%(222/1 139) with dermatosis. Positive DFS with higher titer (≥1∶320) was detected more frequently in autoimmune disease (AID) patients (5.13%, 10/195) than in non-AID patients (1.69%, 16/944) ( P<0.05). The DFS pattern is rare in ANA positive patients, which is mainly observed in women between 21-49 years. High titer of DFS is prevalent in AID patients, but positive DFS is detected more in non-AID patients, especially those with dermatosis.

Research progress of Rab proteins in neurodegenerative diseases / 生理学报

As a member of the Ras superfamily, Rab proteins are small GTP-binding proteins. In the process of endocytosis of macromolecules and substances delivery between organelles, Rab proteins act on vesicle formation, transport, tethering and fusion by recruiting their effectors, therefore being key regulatory factors in vesicle trafficking. Disturbance of localizations and functions of Rab proteins and their effectors are involved in the pathogenesis of several diseases. This review focuses on the main functions of Rab proteins and their possible roles in the onset and progression of neurodegenerative diseases including Parkinson's disease, Alzheimer's disease, and Huntington's disease.

Altered dopamine metabolism and its role in pathogenesis of Parkinson's disease / 生理学报

Parkinson's disease (PD), one of the most frequent neurodegenerative disorders, is characterized by the selective loss of dopaminergic neurons in the substantia nigra (SN). Genetic vulnerability, aging, environmental insults are believed to contribute to the pathogenesis of PD. However, the cellular and molecular mechanism of dopaminergic neurons degeneration remains incompletely understood. Dopamine (DA) metabolism is a cardinal physiological process in dopaminergic neurons, which is closely related to the loss of dopaminergic neurons in the SN. DA metabolism takes part in several pathological processes of PD neurodegeneration, such as iron metabolism disturbance, α-synuclein mis-folding, endoplasmic reticulum stress, protein degradation dysfunction, neuroinflammatory response, etc. In this review, we will describe altered DA metabolism and its contributions to PD pathogenesis.

Efficacy and safety of human chorionic gonadotropin combined with human menopausal gonadotropin and a gonadotropin-releasing hormone pump for male adolescents with congenital hypogonadotropic hypogonadism / 中华医学杂志(英文版)

BACKGROUND@#Compared to adult studies, studies which involve the treatment of pediatric congenital hypogonadotropic hypogonadism (CHH) are limited and no universal treatment regimen is available. The aim of this study was to evaluate the feasibility of human chorionic gonadotropin (hCG)/human menopausal gonadotropin (hMG) therapy for treating male adolescents with CHH.@*METHODS@#Male adolescent CHH patients were treated with hCG/hMG (n = 20) or a gonadotropin-releasing hormone (GnRH) pump (n = 21). The treatment was divided into a study phase (0-3 months) and a follow-up phase (3-12 months). The testicular volume (TV), penile length (PL), penis diameter (PD), and sex hormone levels were compared between the two groups. The TV and other indicators between the groups were analyzed using a t-test (equal variance) or a rank sum test (unequal variance).@*RESULTS@#Before treatment, there was no statistical difference between the two groups in terms of the biochemistry, hormones, and other demographic indicators. After 3 months of treatment, the TV of the hCG/hMG and GnRH groups increased to 5.1 ± 2.3 mL and 4.1 ± 1.8 mL, respectively; however, the difference was not statistically significant (P > 0.05, t = 1.394). The PL reached 6.9 ± 1.8 cm and 5.1 ± 1.6 cm (P  0.05, t = 0.314). After 9 to 12 months of treatment, the T level was higher in the hCG/hMG group. Other parameters did not exhibit a statistical difference.@*CONCLUSIONS@#The hCG/hMG regimen is feasible and effective for treating male adolescents with CHH. The initial 3 months of treatment may be a window to optimally observe the strongest effects of therapy. Furthermore, results from the extended time-period showed positive outcomes at the 1-year mark; however, the long-term effectiveness, strengths, and weaknesses of the hCG/hMG regimen require further research.@*TRIAL REGISTRATION@#ClinicalTrials.gov, NCT02880280; https://clinicaltrials.gov/ct2/show/NCT02880280.

Triterpenoid saponins and phenylpropanoid glycoside from the roots of Ardisia crenata and their cytotoxic activities / 中国天然药物

Two new triterpenoid saponins, ardisicrenoside R and S (1 and 2), and one new phenylpropanoid glycoside, ardicrephenin (3), along with five known compounds (4-8), were isolated from roots of Ardisia crenata. Their structures were elucidated on the basis of NMR spectroscopic data and chemical methods. Compounds 2-7 were evaluated for their cytotoxic activities against A549, MCF-7, HepG2 and MDA-MB-231 cell lines by MTT assay. Ardicrenin (6) showed significant cytotoxicity, with IC

Safety of RhD alloimmunization / 中国输血杂志

【Objective】 To explore the safety of RhD-positive red blood cells (RBCs) immunization schedules in RhD-negative volunteers, so as to facilitate the development of domestic anti-D immunoglobulin. 【Methods】 From January 2018 to April 2020, 23 RhD negative volunteers with informed consent were enrolled and divided into initial immunization group and booster immunization group. The initial immunization included first immunization, second immunization and third immunization. Four groups, i. e. 3 cases of 20 mL, 8 of 30 mL, 6 of 40 mL, and 6 of 50 mL, were involved in initial immunization. After the initial immunization response, booster immunizations were performed every 3 months. According to the anti-D titer before each immunization, the booster immunization doses were set to 0.5, 1 and 2 mL. Whole blood samples of 5mL/ person (time) were collected 24 h and 1 week after each infusion, and the blood routine, liver, kidney and blood coagulation function and anti-D titer were detected. The differences of detection (index) values at 24 h and 1 week after the first immunization and booster immunization in each (dose) group were compared. 【Results】 No statistically significant differences were observed in hemolysis index values (all within the range of medical reference values) 24 h or 1 week after initial immunization among RhD positive RBCs of 20, 30, 40 and 50mL(P>0.05). The differences between the hemolysis index values and the basic values before the immune response (all within the range of medical reference values) after 0.5 or 1 mL booster immunizations were also not statistically different (P>0.05). However, the differences (μmol/L)between total bilirubin levels and the basic values before the immune response (1.55±1.87, 6.29±2.66) were significantly different after 2 mL booster immunization (P<0.05). 【Conclusion】 No risks affecting the safety of RhD negative volunteers was found in the immunization schedule proposed in this study.

Overview of "--" acupuncture, an acupuncture school of 's Zhuang medicine of Guangxi / 中国针灸

The theory of "--" of Zhuang medicine was explored and the academic achievements and experience of professor - were summarized to explain the theory and clinical characteristics of -- acupuncture, an acupuncture school of 's Zhuang medicine of Guangxi. This acupuncture method is guided by the theory of "three- synchronization" and "--" of Zhuang medicine, based on the theory of "three channels and two paths", with regulating as the method and regulating spirit as the basis. After the patient is calmed and resting, the micro needle shallow needling technique is adopted, mainly at the umbilical ring point, so as to achieve the purpose of regulating the mind and treating the root cause.

Vibration response imaging for assessment of lung recruitment in patients with acute respiratory distress syndrome / 医学研究生学报

Objective　Vibration response imaging (VRI) has been applied to the bedside monitoring of critically ill patients. The purpose of this study was to explore the value of VRI in assessing lung recruitment in patients with acute respiratory distress syndrome (ARDS).　Methods　We prospectively studied the clinical data on 20 cases of ARDS treated in our Department of Pulmonary and Critical Care Medicine from January 2015 to June 2017. The positive end-expiratory pressure (PEEP) of the patients was increased from 5 and 15 cm H2O, the mean grey value of the max energy frame of VRI was determined, the quantitative lung data (QLD) were obtained, and the correlation of the VRI image with the recruited lung volume and oxygenation index was analyzed.　Results The patients with PEEP at 15 cm H2O, in comparison with those with PEEP at 5 cm H2O, showed a significantly decreased mean gray value of the max energy frame of VRI (169.1 ± 11.3 vs 175.1 ± 15.9, P = 0.04), increased gray area ([56.3 ± 4.4]% vs [52.7 ± 7.5]%, P < 0.05), declined QLD in the upper left and left middle regions (P < 0.05) and elevated in the lower left and lower right regions (P < 0.05). With the PEEP at 15 cm H2O, the mean gray value of VRI was increased by -5.6 ± 12.8, negatively correlated with the recruited lung volume (r = -0.785, P < 0.01), and the gray area increased (3.8 ± 4.8)%, positively correlated with the recruited lung volume (r =0.793, P < 0.01). With PEEP at 5 and 15 cm H2O, the oxygenation indexes were (116.3 ± 25.6) mmHg and (116.3 ± 25.6) mmHg, respectively, the improvement rate of which correlated negatively with the increased mean gray value of VRI (r = -0.740, P < 0.01) but positively with the gray area (r = 0.581, P < 0.01).　Conclusion　Lung recruitment can be adequately estimated with bedside VRI in patients with ARDS.

Anti-mutant citrullinated vimentin antibody in the diagnosis of rheumatoid arthritis / 中华检验医学杂志

Objective This study aimed to assess the diagnostic value of anti-mutated citrullinated vimentin (MCV) antibodies in rheumatoid arthritis (RA) and its correlation with disease progression, extra-articular manifestations and overlap syndrome. Methods Retrospective Studies. Clinical data of 837 patients in PekingUnionMedicalCollegeHospitalfrom June to August 2017 were collected, including the result of anti-MCV, anti-cyclic citrullinated peptide (anti-CCP) antibodies, rheumatoid factor (RF), erythrocyte sedimentation rate (ESR) and High-sensitivity-C-reactive protein (CRP). According to the 1987 American College of Rheumatology classification criteria for rheumatoid arthritis, there were 323 patients diagnosed with RA, including 59 males and 264 females with the average age of 51 years. According to whether the RA patients have overlap syndrome with other autoimmune disease (AID) or have extra-articular manifestations, 258 cases were categorized into RA group, including 47 males and 211 females with the average age of 50 years; 14 cases were categorized into the group of overlap syndrome, including 1 male and 13 females with the average age of 36 years;51 cases were categorized into the group of extra-articular manifestations, including 11 males and 40 females with the average age of 59 years.According to 2010 rheumatoid arthritis classification criteria for destruction in joints, the radiographic changes were divided into 4 stages. There were 203 casesenrolled in our study, 88 caseswere fitted into early stage group (stage I)including 21 males and 67 females with the average age of 48 years; 115 caseswere fitted into progressive stage group, which compromisedstageⅡ (interim stage), stage Ⅲ (severe stage) and stage Ⅳ(final stage) cases, including 19 males and 96 females with the average age of 53 years. Mann-Whitney U test, x2 test, Receiver operating characteristic (ROC) curves and Spearmancorrelation coefficientwere used in Statistical analysis. Results Ⅰ Amongdiagnosed RA patients, 199 (61.6％) cases were positive for anti-MCV, anti-CCP and RFsimultaneously, 42 (13％) cases were positive for anti-MCV, which was higher than anti-CCP positive (1 cases, 0.3％) or RF positive (7cases, 2.2％). The difference was statistically significant(P<0.001, P<0.001). ⅡROC was calculated and MCV=35.95 U/ml was used as best-fit cut-off value. The AUC for anti-MCV was 0.867, while the sensitivity was 80.5％and specificity was 80.9％.ⅢThe detection levels of anti-MCV (682.8 (106.4-1000.0)), anti-CCP (407 (4.0-1536.0)) and RF (82.8 (21.1-244.9)) in the group of progressive stage were higher than those in the group of early stage (114.5 (28.5-1000.0), 62.5 (5.0-1020.7), 50.1 (6.7-127.1)), which showed a significant difference(P<0.05, P<0.05, P<0.05). The anti-MCV, anti-CCP and RF were positively related to the degree of joint destruction (r=0.229, P<0.05;r=0.187, P<0.05;r=0.167, P<0.05);anti-MCV and anti-CCP were positively related to extra-articular manifestation (r=0.152, P<0.05;r=0.136, P<0.05). Conclusion Anti-MCV antibodies are more sensitive in patients with RA, and have complementary diagnostic value for anti-CCP and RF-negative patients; high levels of anti-MCV and anti-CCP in RA patients are associated with RA progression and extra-articular involvement.

Activation of mitogen-activated protein kinases in satellite glial cells of the trigeminal ganglion contributes to substance P-mediated inflammatory pain / 国际口腔科学杂志·英文版

Inflammatory orofacial pain, in which substance P (SP) plays an important role, is closely related to the cross-talk between trigeminal ganglion (TG) neurons and satellite glial cells (SGCs). SGC activation is emerging as the key mechanism underlying inflammatory pain through different signalling mechanisms, including glial fibrillary acidic protein (GFAP) activation, phosphorylation of mitogen-activated protein kinase (MAPK) signalling pathways, and cytokine upregulation. However, in the TG, the mechanism underlying SP-mediated orofacial pain generated by SGCs is largely unknown. In this study, we investigated whether SP is involved in inflammatory orofacial pain by upregulating interleukin (IL)-1β and tumour necrosis factor (TNF)-α from SGCs, and we explored whether MAPK signalling pathways mediate the pain process. In the present study, complete Freund's adjuvant (CFA) was injected into the whisker pad of rats to induce an inflammatory model in vivo. SP was administered to SGC cultures in vitro to confirm the effect of SP. Facial expression analysis showed that pre-injection of L703,606 (an NK-1 receptor antagonist), U0126 (an inhibitor of MAPK/extracellular signal-regulated kinase [ERK] kinase [MEK] 1/2), and SB203580 (an inhibitor of P38) into the TG to induce targeted prevention of the activation of the NK-1 receptor and the phosphorylation of MAPKs significantly suppressed CFA-induced inflammatory allodynia. In addition, SP promoted SGC activation, which was proven by increased GFAP, p-MAPKs, IL-1β and TNF-α in SGCs under inflammatory conditions. Moreover, the increase in IL-1β and TNF-α was suppressed by L703, 606, U0126 and SB203580 in vivo and in vitro. These present findings suggested that SP, released from TG neurons, activated SGCs through the ERK1/2 and P38 pathways and promoted the production of IL-1β and TNF-α from SGCs, contributing to inflammatory orofacial pain associated with peripheral sensitization.

Exosomes and their roles in neurodegenerative diseases: from pathogenic, diagnostic and therapeutical perspectives / 生理学报

Exosomes are extracellular membranous vesicles with a diameter of 30-100 nm derived from a variety of eukaryocytes. The cargo of exosomes includes proteins, lipids, nucleic acids, and substances of the cells from which they originate. They can transfer functional cargo to neighboring and distal cells, therefore contributing to intercellular communication in both physiological and pathological processes. In recent years, it was shown that exosomes in several neurodegenerative diseases are closely related to the transmission of disease-related misfolded proteins (such as α-synuclein, tau, amyloid β-protein, etc). These proteins are transported by exosomes, thus promoting the propagation to unaffected cells or areas and accelerating the progression of neurodegenerative diseases. This review focuses on the origin and composition, biological synthesis, secretion, function of exosomes, as well as their roles in the pathogenesis and progression of neurodegenerative diseases. In addition, we also discuss that exosomes can serve as biomarkers and drug delivery vehicles, and play a role in the diagnosis and treatment of neurodegenerative diseases.

The protective effect of astrocyte inhibitor fluorocitrate on subarachnoid hemorrhage in rats / 西安交通大学学报(医学版)

Objective To study the effects of fluorocitrate (FC),astrocytic metabolic inhibitor,on early brain injury after subarachnoid hemorrhage (SAH)in rats so as to explore the mechanism of early brain injury mediated by astrocyte after SAH.Methods Thirty six SD male rats were randomly divided into sham group,SAH 3 d group and SAH 3 d+FC group,with 12 rats in each group.The model of SAH was established by an endovascular perforation technique. FC was injected into the lateral ventricle. Three days after SAH, the expressions of GFAP,Iba-1 and TNF-α were detected using immunohistochemistry in all rats.The expression and phosphorylation of NF-κB in the nucleus were detected by Western blot.The expressions of TNF-α,IL-1βand IL-6 were detected by ELISA.Cell apoptosis was detected by TUNEL.Results Neuronal swelling,nuclear anomalies, disorganization of micrangium,abnormality of endothelial cells appeared in SAH 3 d group,but not in sham group. The expressions of NSE,GFAP and Iba-1 were significantly increased in SAH 3 d group compared with those in sham group (all P＜0.05).The number of apoptotic cells was increased.The expression and phosphorylation of NF-κB were significantly increased.The expressions of TNF-α,IL-1β and IL-6 were significantly increased.However, neuronal injuries were alleviated by injecting FC.The expressions of NSE,GFAP and Iba-1 in SAH 3 d+FC group were inhibited.The number of apoptotic cells in SAH 3 d+FC group was decreased compared with that in SAH 3 d group.The expression and phosphorylation of NF-κB were decreased by FC.The expressions of TNF-α,IL-1β and IL-6 were significantly decreased by FC (P＜0.05).Conclusion Astrocytes may play an important role in early brain injury after SAH,underlying the mechanism that they released TNF-α,IL-1βand IL-6 and activate microglia by activating NF-κB signal.The inhibition of excess activation of astrocytes may plays a protective role in early brain injury after SAH.

GBA mutations and Parkinson's disease / 生理学报

Parkinson's disease (PD) is a common neurodegenerative disease characterized by the degeneration of dopaminergic neurons in the substantia nigra and the intraneuronal Lewy bodies in this area. Genetic mutations in PD pathogenesis have been explored and better understood in recent years. GBA variants are now considered to be the single largest risk factor for PD. Gaucher disease (GD) is a lysosomal storage disorder disease and an inherited deficiency of lysosomal glucocerebrosidase (GCase) arising from mutations in the gene GBA. A group of patients with GD exhibit parkinsonian symptoms, meanwhile, GBA mutations are more frequently observed in patients with PD. These lines of evidence suggest a close relationship between GBA mutations and PD. GBA mutations are associated with an earlier onset age and a distinct cognitive decline in PD. GCase loss-of-function caused by GBA mutations interferes with the degradation of α-synuclein, and α-synuclein pathology in turn inhibits normal GCase function in PD, which forms a vicious cycle. However, the exact mechanisms for this bidirectional pathogenic loop have not to be fully elucidated. In this review, we summarize the current understandings on the potential link between GBA mutations and PD pathogenesis, which may show novel insights into PD etiology and therapeutics.

Clinical characteristics and treatment progress of adolescent and young adult with colorectal cancer / 国际肿瘤学杂志

Colorectal cancer is one of the most common malignant tumors of digestive system.There are significant differences between young patients and other ages in aspects of the disease features, biological characteristics, risk factors, clinical treatment and prognosis, etc.And the analysis of young colorectal cancer patients′ characteristics can provide new ideas for clinical treatment.

Two new steroidal saponins isolated from Anemarrhena asphodeloides / 中国天然药物

Two new steroidal saponins, named timosaponin P (1) and timosaponin Q (2), were isolated from the rhizome parts of Anemarrhena asphodeloides Bunge using various chromatographic methods. Their structures and absolute configurations were elucidated by a combination of spectroscopic and spectrometric data, including 1D, 2D NMR, HR-ESI-MS and ECD calculations, and this is the first time the absolute configuration of C-23 of steroidal saponin was confirmed by ECD calculations.

The effect of pH and ligand density on the endocytosis and exocytosis process of FcBP decorated PEG-PCL micelles on Caco-2 cells / 药学学报

The difference in pH between apical and basolateral side of intestinal epithelial and pH dependence character of the combination of FcRn (neonatal Fc receptor) and ligand might improve the delivery of hydrophobic drugs by facilitating the transcytosis of nanocarriers. Here we designed FcBP (IgG Fc domain-binding peptides) decorated coumarin 6 (C6) loaded poly(ethyl ethylene phosphate)-co-poly(ε-caprolactone) (PEG-PCL) micelles with different ligand densities to study the effect of pH and ligand density on the endocytosis and exocytosis process of micelles on human colon adenanocaricinoma cell lines (Caco-2). Active micelles with different ligand densities and passive micelles were prepared using the thin-film hydration method. The size of the micelles was characterized by dynamic light scattering analysis and the morphology was observed by transmission electron microscope. The endocytosis and exocytosis of the micelles at pH 7.4 and pH 6.0, as well as the effect of FcRn on the endocytosis, were investigated by flow cytometry. The results showed that the size of micelles was about 30 nm, which was not affected by FcBP decoration. We found that pH and ligand density could both influence the endocytosis. The uptake of active micelles was higher at pH 6.0 than at pH 7.4, and an optimal ligand density of endocytosis was appeared in both pH environment. Then we proved that FcBP decorated micelles could be endocytosed at pH 6.0 and exocytosed at pH 7.4, and the exocytosis process was also related to ligand density. Micelles with 10% ligand density had the largest exocytosis, showing the potentiality to deliver drugs through the intestinal epithelial. In addition, the competitive inhibition experiments illustrated that the interaction between FcRn and FcBP were essential to endocytosis. The results will enhance the understanding on the FcBP decorated PEG-PCL micelles for transmemberane drug delivery.

Lipoic acid effects on electrophysiological changes of the sciatic nerve following ischemia/reperfusion injury / 中国组织工程研究

BACKGROUND:Lipoic acid, with a closed circle structure composed by sulphur and carbon atoms, exerts strong anti-oxidation, and has been extensively applied in the prevention and treatment of oxidative stress, diabetic cataract, diabetic neuropathy and cardiovascular diseases. OBJECTIVE:To investigate the protective effect of lipoic acid on peripheral nerve function during peripheral nerve ischemia/reperfusion injury. METHODS:Models of peripheral nerve ischemia/reperfusion injury were established in rabbits, and then rabbit models were then allotted to treatment and non-treatment groups. The treatment group was subdivided into experimental (injection of lippoic acid) and control groups according to the use of lipoic acid at 1, 3 and 6 hours after ischemia and before reperfusion. The ultrastructural changes of the sciatic nerve were observed under electron microscope, and the electrophysiological changes of the sciatic nerve were detected using evoked potential instrument. RESULTS AND CONCLUSION:With the ischemic time increasing, the number of vacuoles in the axon increased gradually, accompanied by axonal atrophy, and Waller's degeneration in the aggregated microfilaments. The myelin sheath thickening and dissolving were visible. All above phenomena became severest at 6 hours after ischemia. Compared with the control groups, lipoic acid reduced the number of the vacuoles in the axon and all eviated axonal atrophy, Waller's degeneration and demyelination. As the ischemic time increasing, the latency of sciatic nerve was significantly increased, and peaked at 6 hours of ischemia;while the amplitude was significantly decreased, and reached a minimum at 6 hours of ischemia. Compared with the control groups, in the experimental groups, the latency of sciatic nerve was significantly decreased, but the amplitude was significantly increased. These results suggest that lipoic acid provides neuroprotection against peripheral nerve ischemia/reperfusion injury.