Neurexin and neuroligins jointly regulate synaptic degeneration at the Drosophila neuromuscular junction based on TEM studies.

The Drosophila larval neuromuscular junction (NMJ) is a well-known model system and is often used to study synapse development. Here, we show synaptic degeneration at NMJ boutons, primarily based on transmission electron microscopy (TEM) studies. When degeneration starts, the subsynaptic reticulum (SSR) swells, retracts and folds inward, and the residual SSR then degenerates into a disordered, thin or linear membrane. The axon terminal begins to degenerate from the central region, and the T-bar detaches from the presynaptic membrane with clustered synaptic vesicles to accelerate large-scale degeneration. There are two degeneration modes for clear synaptic vesicles. In the first mode, synaptic vesicles without actin filaments degenerate on the membrane with ultrafine spots and collapse and disperse to form an irregular profile with dark ultrafine particles. In the second mode, clear synaptic vesicles with actin filaments degenerate into dense synaptic vesicles, form irregular dark clumps without a membrane, and collapse and disperse to form an irregular profile with dark ultrafine particles. Last, all residual membranes in NMJ boutons degenerate into a linear shape, and all the residual elements in axon terminals degenerate and eventually form a cluster of dark ultrafine particles. Swelling and retraction of the SSR occurs prior to degradation of the axon terminal, which degenerates faster and with more intensity than the SSR. NMJ bouton degeneration occurs under normal physiological conditions but is accelerated in Drosophila neurexin (dnrx) dnrx273, Drosophila neuroligin (dnlg) dnlg1 and dnlg4 mutants and dnrx83;dnlg3 and dnlg2;dnlg3 double mutants, which suggests that both neurexin and neuroligins play a vital role in preventing synaptic degeneration.

Optimizing Sample Preparation Process for Transmission Electron Microscopy of Neuromuscular Junctions in Drosophila Larvae.

The Drosophila neuromuscular junction (NMJ) has emerged as a valuable model system in the field of neuroscience. The application of confocal microscopy at the Drosophila NMJ enables researchers to acquire synaptic information, encompassing both quantitative data on synapse abundance and detailed insights into their morphology. However, the diffuse distribution and limited visual range of the TEM present challenges for the ultrastructural analysis. This study introduces an innovative and efficient sample preparation method that surpasses the conventional approach. The procedure begins by placing a metal mesh at the base of a flat-bottomed bottle or test tube, followed by positioning fixed larvae samples onto the mesh. An additional mesh is placed over the samples, ensuring that they are positioned between the two meshes. The fixed samples are thoroughly dehydrated and infiltrated before proceeding with the embedding procedure. Then embedding of the samples in epoxy resin is performed in a flat sheet manner, which allows for the preparation of muscles for positioning and sectioning. Benefiting from these steps, all the muscles of Drosophila larvae can be visualized under light microscopy, therey facilitating subsequent positioning and sectioning. Excess resin is removed after locating the 6th and 7th muscles of body segments A2 and A3. Serial ultra-thin sectioning of the 6th or 7th muscle is performed.

Construction and optimization of automatic checking mode for unit dose dispensing system of oral drugs / 中国药房

OBJECTIVE To provide a reference for establishing an automatic checking mode and improving the checking efficiency of the unit dose dispensing system of oral drugs in hospital. METHODS The automatic checking process reengineering team was established in our hospital. ECRSI method was adopted to sort out the verification process and mode of drug bags for the unit dose formula of our hospital through five principles of eliminating， combining， rearranging， simplifying and increasing， and the hardware series problem and the problem of excessive system false-positive proportion were optimized. The drug bags for the unit dose formula were randomly selected from 10 wards， the efficiency and external error rates of manual check and automatic checking mode before and after optimization were compared， and the false-positive reporting failure in automatic checking mode was also compared before and after optimization. RESULTS After the establishment of the automatic checking mode of the unit dose formula for oral drugs， the average checking time of drug bags was significantly shorter than that of manual checking mode in the other 8 wards except for cardiovascular and renal departments （P＜0.05）. After the optimization of the automatic checking mode， the average checking time of drug bags in all wards was significantly shorter than that in manual checking mode （P＜0.05）. Compared with before optimization of the automatic checking mode， the average checking time of drug bags was shortened by 0.43 s， and the average checking time of drug bags in half of the wards was shortened significantly （P＜0.05）. At the same time， the false-positive proportion decreased from 96.83% before optimization to 92.76% after optimization （P＜0.05）. The external error rate dropped from 0.039‰ in manual checking mode to 0.019‰ before optimization and 0.015‰ after optimization （P＜0.05）. CONCLUSIONS Based on ECRSI method， the automatic checking mode for the unit dose dispensing system of oral drugs can effectively reduce the average checking time of drug bags， reduce external error and improve the work efficiency of pharmacists.

Clinical characteristics and genetic analysis of four patients with central hypothyroidism due to IGSF1 gene variants / 中华医学遗传学杂志

OBJECTIVE@#To explore the clinical manifestations and genetic characteristics of patients with congenital central hypothyroidism due to variants of IGSF1 gene.@*METHODS@#Clinical data, results of genetic testing, and follow-up of four patients admitted to Children's Hospital of Soochow University during 2017 to 2021 were retrospectively analyzed.@*RESULTS@#All of the four patients were males. Patient 1 had presented neonatal jaundice, patients 2 and 3 were admitted for growth retardation during childhood, and thyroid function test indicated slightly low free thyroxine (FT4), patient 4 was found to have reduced FT4 in the neonatal period. Genetic testing revealed that all of the four patients have harbored pathogenic variants of the IGSF1 gene, which were all inherited from their mothers. The thyroid functions in all patients were well controlled with oral levothyroxine and regular follow-up.@*CONCLUSION@#Pathogenic variants of the IGSF1 gene probably underlay the congenital central hypothyroidism with a variety of clinical manifestations, and genetic testing can facilitate the diagnosis at an early stage.

Improved analysis method of neuromuscular junction in Drosophila larvae by transmission electron microscopy.

The Drosophila neuromuscular junction is an excellent model for neuroscience research. However, the distribution of neuromuscular junctions is very diffuse, and it is not easy to accurately locate during ultrathin sectioning, which seriously interferes with the ultrastructural analysis under electron microscopy that only has a small field of view. Here, we reported an efficient method for acquiring the ultrastructural picture of neuromuscular junctions in Drosophila larva under electron microscopy. The procedure was as follows: first, the larval sample of body wall muscle was placed between the metal mesh and was dehydrated with alcohol and infiltrated with epoxy resin to prevent the sample from curling or bending, after it was dissected and fixed into thin slices. Second, the sample was embedded in resin into a flat sheet to facilitate the positioning of the muscles. Third, carefully and gradually remove the excess resin and the cuticle of the larvae, cut off both ends of the special body segment, and trim the excess specific muscles according to the recommended ratio of trimming muscles, which would reduce the workload exponentially. At last, the trimmed sample were prepared into serial about 1000 ultrathin sections that was about total 80 microns thickness, and 30-40 sections were gathered into a grid to stain with lead citrate and uranyl acetate. This method could also be applied to the other small and thin samples such as the Drosophila embryo, ventral nerve cord and brain.

Comparative Morphology of the Lungs and Skin of two Anura, Pelophylax nigromaculatus and Bufo gargarizans.

The lungs and skin are important respiratory organs in Anura, but the pulmonary structure of amphibians remains unclear due to the lack of a suitable procedure. This study improved the procedure used for fixing lungs tissues and used light microscopy, transmission electron microscopy and scanning electron microscopy to reveal the differences in the lung and skin morphologies between Pelophylax nigromaculatus (P. nigromaculatus) and Bufo gargarizans (B. gargarizans). In P. nigromaculatus and B. gargarizans, the cystic lungs comprise a continuous outer pulmonary wall on which primary, secondary, and tertiary septa attach, and a number of regular lattices form from raised capillaries and the pulmonary epithelium on the surfaces of the pulmonary wall and septa. Each lattice in P. nigromaculatus consists of several elliptical sheets and flat bottom, and the septa are distributed with denser sheets and have a larger stretching range than the pulmonary wall. The lattice in B. gargarizans consists of thick folds and an uneven bottom with several thin folds, and the septa have more developed thick and thin folds than the pulmonary wall. However, the density of the pulmonary microvilli, the area of a single capillary, the thicknesses of the blood-air barrier, pulmonary wall and septum, and the lung/body weight percentage obtained for B. gargarizans were higher than those found for P. nigromaculatus. In P. nigromaculatus, the dorsal skin has dense capillaries and a ring surface structure with mucus layer on the stratum corneum, and the ventral skin is slightly keratinized. In B. gargarizans, the stratum corneum in both the dorsal and ventral skins is completely keratinized. A fine ultrastructure analysis of P. nigromaculatus and B. gargarizans revealed that the pulmonary septa are more developed than the pulmonary walls, which means that the septa have a stronger respiratory function. The more developed lungs are helpful for the adaptation of B. gargarizans to drought environments, whereas P. nigromaculatus has to rely on more vigorous skin respiration to adapt to a humid environment.

Neurexin and Neuroligins Maintain the Balance of Ghost and Satellite Boutons at the Drosophila Neuromuscular Junction.

Neurexins and neuroligins are common synaptic adhesion molecules that are associated with autism and interact with each other in the synaptic cleft. The Drosophila neuromuscular junction (NMJ) bouton is a well-known model system in neuroscience, and ghost and satellite boutons, respectively, indicate the poor development and overgrowth of the NMJ boutons. However, the Drosophila neurexin (DNrx) and Drosophila neuroligins (DNlgs) are mainly observed in type Ib boutons, indicating the ultrastructural and developmental phenotypes of the Drosophila NMJ. Here, we identified the ultrastructural and developmental features of ghost and satellite boutons by utilizing dneurexin (dnrx) and dneuroligins (dnlgs) fly mutants and other associated fly strains. Ghost boutons contain synaptic vesicles with multiple diameters but very rarely contain T-bar structures and swollen or thin subsynaptic reticulum (SSR) membranes. The muscle cell membrane is invaginated at different sites, stretches to the ghost bouton from different directions, forms several layers that enwrap the ghost bouton, and then branches into the complex SSR. Satellite boutons share a common SSR membrane and present either a typical profile in which a main bouton is encircled by small boutons or two atypical profiles in which the small boutons are grouped together or distributed in beads without a main bouton. Electron and confocal microscopy data showed that dnrx, dnlg1, dnlg2, dnlg3, and dnlg4 mutations led to ghost boutons; the overexpression of dnrx, dnlg1, dnlg2, dnlg3, and dnlg4 led to satellite boutons; and the dnlg2;dnlg3 double mutation also led to satellite boutons. These results suggested that DNrx and DNlgs jointly maintain the development and function of NMJ boutons by regulating the balance of ghost and satellite boutons in Drosophila.

Association between family adversity exposed to different period and psychopathological symptoms among adolescents in rural areas / 中国学校卫生

Objective@#To investigate the cumulative and sensitive period effects of family adversity on the outcome of psychopathological symptoms,so as to provide evidence for the prevention and intervention of adverse events.@*Methods@#A total of 710 adolescents were recruited from local schools in rural area of Fuyang,Anhui Province in Dec. 2017 by using the convenience sampling method. The Adverse Childhood Experiences Questionnaire was used to assess family adversity. The MacArthur Health & Behavior Questionnaire was used to assess internalizing and externalizing symptoms. Multiple linear regression model was used to analyze the association between number and time of family adversity and psychopathological symptoms.@*Results@#Persistent family adversity was associated with increased internalizing symptoms [(β(95%CI)=0.35(0.15-0.54)] and increased externalizing symptoms [β(95%CI)=0.16(0.01-0.32)]. 2 and ≥3 family adversities were associated with increased internalizing symptoms[β(95%CI)=0.20(0.04-0.36),0.42(0.24-0.60)]and increased externalizing symptoms[β(95%CI)=0.14(0.01-0.26),0.23(0.09-0.37)]. In childhood family adversity group,2 and ≥3 family adversities were associated with increased internalizing symptoms [β(95%CI)=0.23(0.06-0.41),0.34(0.11-0.58)] and increased externalizing symptoms [β(95%CI)=0.17(0.02-0.31),0.21(0.02-0.39)]. In persistent family adversity group,≥3 family adversities were associated with increased internalizing symptoms[β(95%CI)=0.56(0.31-0.82)] and increased externalizing symptoms [β(95%CI)=0.24(0.02-0.45)]. Adolescence family adversity was not associated with psychopathological symptoms.@*Conclusion@#The cumulative family adversity may increase the risk of psychopathological symptoms,and that childhood may be the sensitive period for family adversity to cause psychopathological symptoms.

Effects of tubacin on membrane surface structure of BMSCs and mechanical property / 重庆医学

Objective To study the effect different concentrations of HDAC6 inhibitor tubacin on the proliferation,morphology and membrane surface ultrastructure of bone marrow mesenchymal stem cells(BMSCs).Methods Primary BMSCs were cultured.The P4 generation cells were taken for conducting the experiment.The different concentrations of tubacin were used to treat the cells fro 24 h.The cells survival rate was detected by MTT assay.The atomic force microscopy(AFM) was applied to observe the cellular morphology and surface ultramicrostructure and detect the mechanical property in different groups.Results The MTT results showed that low concentration of tubacin had the effect for promoting BMSC proliferation;the AFM results showed that compared with the control group,the height and width of BMSCs after treating by low concentration of tubacin,the membrane surface roughness was decreased and cellular hardness was increased.Conclusion Low concentration of tubacin can promote the BMSC proliferation,causes the changes of morphology and membrane surface ultramicrostructure,enhances the mechanical property and increases the cell implantation treatment efficiency.

Tumor necrosis factor alpha-induced apoptosis in bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Stem cel transplantation has achieved good results in the treatment of cerebral ischemia, and how to reduce apoptosis of transplanted cel s has become the focus of the therapy. OBJECTIVE:To investigate the injured effect of tumor necrosis factor alpha (TNF-α) on bone marrow mesenchymal stem cel s and its mechanism. METHODS:Primary cultured bone marrow mesenchymal stem cel s from Sprague-Dawley rats were treated with 200μg/L TNF-αfor 6 hours. Cel vitality was assayed by MTT, and cel apoptosis was observed by Hoechst33342 staining. Apoptotic rate was detected by Annexin-V/PI double staining. Level of oxidative stress was evaluated by determination of malondialdehyde and superoxide dismutase levels. The protein expressions of phosphorylated-Akt, Akt, phosphorylated-FoxO1, FoxO1 were detected by western blot analysis. RESULTS AND CONCLUSION:After treatment with TNF-α, the cel vitality of bone marrow mesenchymal stem cel s decreased, the apoptotic rate increased, and the cel s were arrested in the S phase. Moreover, the oxidative stress level was elevated, and the protein expression of phosphorylated-Akt and phosphorylated-FoxO1 was significantly reduced compared with the control group (P<0.05). These results suggest that TNF-αat high level contributes to the S-stage arrest, responsible for the apoptosis processes of bone marrow mesenchymal stem cel s via the Akt-FoxO1 pathway.

Determination of Cinnamic Aldehyde Content in Xianggui Huazhuo Capsules by Gas Chromatography-Mass Spectrometry / 医药导报

Objective To establish a method for determining cinnamic aldehyde content in Xianggui Huazhuo capsules by gas chromatography-mass spectrometry (GC-MS). Methods The content of cinnamic aldehyde was determined by GC-MS. Separation was performed on a capillary column (30 m×0. 25 mm, 0. 25 μm) with HP-5 as the stationary phase. A programmed temperature was employed. The flow rate was 1 mL·min-1 with He as carrier gas, and split ratio was 50∶1. The injection volume was 1. 0 μL. Results The cinnamic aldehyde was well isolated from the other ingredients. A good linear relationships of cin-namic aldehyde in range of 0. 02-4. 00 mg·mL-1 was observed. The correlation coefficient was 0. 999 4. The average recovery of cinnamic aldehyde was 96. 2% , and RSD was less than 2. 11% . Conclusion The method is simple, accurate and suitable for determination of cinnamic aldehyde content.

Ophiopogonin D protects cardiomyocytes against doxorubicin-induced injury through suppressing endoplasmic reticulum stress / 药学学报

This study aimed to examine whether ophiopogonin D (OP-D) is capable of protecting cardiomyocytes against DOX-induced injury and the mechanisms involved. H9c2 cells were cultured. MTT assay was used to evaluate cell viability and toxicity. Mito-tracker as fluorescence probe was used to measure ROS content raised from mitochondria. The mRNA and protein expression of ATF6alpha, GRP78 and CHOP were analyzed using real-time PCR and Western blotting, respectively. The results showed that a significant endoplasmic reticulum stress (ERS) was induced upon exposure of H9c2 cells to DOX as indicated by the increase in the expression of ERS related proteins, which was paralleled with the accumulation of reactive oxygen species (ROS) and decrease in the viability of H9c2 cells. Whereas, DOX-induced ROS accumulation and up-regulation of ERS related proteins were partially abolished by pretreatment with OP-D. Consequently, a DOX-induced ERS was mitigated by application of OP-D. Similarly, DOX-induced decrease in cell viability was partially attenuated by either inhibiting CHOP or pretreatment with N-acetylcysteine (NAC), an antioxidant. Moreover, cardiac ultrastructural abnormalities seen in mouse receiving DOX injections were obviously ameliorated by pretreatment of OP-D. Taken together, the present study proved that OP-D protects cardiomyocytes against DOX-induced injury, at least in part, through reducing ROS accumulation and alleviating ERS.

Detecting Thermal Stability of Cefmenoxime Hydrochloride in Infusion Solutions by Classical Isothermal Kinetic Method and Multivariate Linear Model / 医药导报

Objective To investigate thermal degradation kinetic characteristics of Cefmenoxime Hydrochloride in infusion solutions, and predict its thermal stability. Methods The HPLC was applied to determine the contents of Cefmenoxime Hydrochloride. Classical isothermal kinetic method and multivariate linear model were used to predict the expiration date of the injection. Results It was found that the thermal degradation kinetics of Cefmenoxime Hydrochloride in two infusion solutions corresponded with the first-order kinetics. The expiration dates of Cefmenoxime Hydrochloride in 0. 9%sodium chloride injection calculated by two different methods were 2. 20 days and 1. 52 days,and in 5% glucose injection were 2. 09 days and 1. 53 days,respectively. Conclusion The thermal stability of Cefmenoxime Hydrochloride in infusion solutions is poor and its expiration dates are the same calculated by two different methods.

Effect of betulinic acid preconditioning on oxidative stress response during cerebral ischemia-reperfusion in mice / 中华麻醉学杂志

Objective To evaluate the effects of betulinic acid preconditioning on oxidative stress response during cerebral ischemia-reperfusion (I/R) in mice.Methods Seventy-two male Kunming mice,aged 3 months,weighing 25-35 g,were randomly divided into 3 groups (n =24 each) using a random number table:sham operation group (group S),I/R group,and betulinic acid preconditioning group (group BP).Cerebral I/R was induced by middle cerebral artery occlusion in mice anesthetized with 10％ chloral hydrate 40 ml/kg.In group BP,betulinic acid 50 mg/kg was administered by intragastric gavage everyday for 7 days before ischemia,while the equal volume of solvent dimethyl sulfoxide was given in S and I/R groups.At 22 h of reperfusion,neurological function was assessed and scored.The mice were then sacrificed and brains were removed for determination of infarct size,expression of NADPH oxidase (Nox1,Nox2 and Nox4) and p22phox mRNA,activity of ROS and apoptosis rate in the infarcted zone.Results Compared with S group,neurological score,cerebral infarct size,activity of ROS and apoptosis rate in the infarcted zone were significantly increased,and the expression of Nox1,Nox2,Nox4 and p22phox mRNA was up-regulated in group I/R.Compared with group I/R,neurological score,cerebral infarct size,activity of ROS and apoptosis rate in the infarcted zone were significantly decreased,and the expression of Nox1,Nox2,Nox4 and p22phox mRNA was down-regulated in group BP.Conclusion Betulinic acid preconditioning mitigates cerebral I/R injury through inhibiting oxidative stress response in mice.

Mitochondrial dysfunction induced by excessive ROS/RNS-metabolic cardiovascular disease and traditional Chinese medicines intervention / 中国中药杂志

Metabolic cardiovascular disease is a type of disease which almost caused by body carbohydrate and lipid metabolism dysfunction. Type 2 diabetes mellitus is a typical metabolic disease. It not only lead to the insulin resistance but also related to atherosclerosis. Oxidative stress is produced by the reactive oxygen/nitrogen species (ROS/RNS). Oxidative stress and its consequence events play important roles in atherosclerosis (AS). Mitochondria are both sources and targets of reactive oxygen and/or nitrogen species (ROS/RNS), and there is growing evidence that mitochondrial dysfunction may be relevant intermediate mechanism by which cardiovascular risk factors lead to the formation of vascular lesions. Several cardiovascular risk factors are demonstrated causes of mitochondrial damage. This review starts with excessive ROS/RNS-induced mitochondrial dysfunction. The authors emphasize the relationship among axis of excessive ROS/RNS-mitochondrial dysfunction-apoptosis-atherosclerosis. They also introduce several traditional Chinese medicines such as Ophiopogon japonicus, butin, Panax ginseng, Pueraria lobata, Solanum lyratum and so on in the treatment of relevant diseases through anti-ROS/RNS mechanism. Moreover, the TCMs also can anti-cancer and anti-fatigue,which show the speciality of TCMs different from the single effect of classical western medicines.