ObjectiveTo investigate the protective effect of the extract of Liuwei Dihuangwan （LW） on mitochondrial damage in the Alzheimer's disease （AD） model of Caenorhabditis elegans （C. elegans）. MethodC. elegans transfected with human β-amyloid protein （Aβ） _1-42 gene was used as an AD model. The rats were divided into blank group， model group， metformin group （50 mmol·L^-1）， and low， medium， and high dose （1.04， 2.08， 4.16 g·kg^-1） LW groups. Behavioral methods were used to observe the sensitivity of 5-hydroxytryptamine （5-HT） in nematodes. Western blot was used to detect the expression of Aβ in nematodes. Total ATP content in nematodes was detected by the adenine nucleoside triphosphate （ATP） kit， and mitochondrial membrane potential was detected by the JC-1 method. In addition， the mRNA expression of Aβ expression gene （Amy-1）， superoxide dismutase-1 （SOD-1）， mitochondrial transcription factor A homologous gene-5 （HMG-5）， mitochondrial power-associated protein 1 （DRP1）， and mitochondrial mitoprotein 1 （FIS1） was detected by real-time fluorescence quantitative polymerase chain reaction （RT-PCR）. ResultThe extract of LW could reduce the hypersensitivity of the AD model of nematodes to exogenous 5-HT （P<0.05） and delay the AD-like pathological characteristics of hypersensitivity to exogenous 5-HT caused by toxicity from overexpression of Aβ in neurons of the AD model of nematodes. Compared with the blank group， in the model group， the mRNA expression of Aβ protein and Amy-1 increased （P<0.01）， and the mRNA expression of SOD-1 and HMG-5 decreased （P<0.01）. The mRNA expression of DRP1 and FIS1 increased （P<0.01）， and the level of mitochondrial membrane potential decreased （P<0.05）. The content of ATP decreased （P<0.01）. Compared with the model group， in the positive medicine group and medium and high dose LW groups， the mRNA expression of Aβ protein and Amy-1 decreased （P<0.05，P<0.01）， and the mRNA expression of SOD-1 and HMG-5 increased （P<0.01）. The mRNA expression of DRP1 decreased （P<0.05，P<0.01）， and that of FIS1 decreased （P<0.01）. The level of mitochondrial membrane potential increased （P<0.01）， and the content of ATP increased （P<0.05，P<0.01）. ConclusionThe extract of LW may enhance the antioxidant ability of mitochondria， protect mitochondrial DNA， reduce the fragmentation of mitochondrial division， repair the damaged mitochondria， adjust the mitochondrial membrane potential， restore the level of neuronal ATP， and reduce the neuronal damage caused by Aβ deposition.

In recent years, polysaccharides have received much attention because of their high safety and good immunological activity. The study of polysaccharide in vivo process is a key scientific problem that needs to be solved for polysaccharide drug development. Some progress has been made in the field of polysaccharide pharmacokinetics and immunomodulation. However, due to the lack of both chromogenic and light-absorbing groups and the complex molecular structure of polysaccharides, the in vivo processes and immunomodulatory mechanisms of polysaccharides have been slow to be investigated. The effective combination of multiple techniques can break the bottleneck of difficult tracing and unknown immunomodulatory mechanism of polysaccharides in vivo, and promote the development and utilization of polysaccharides. In this paper, we systematically summarize the key techniques in the study of polysaccharide in vivo processes and immunomodulatory mechanisms in order to provide technical references and research ideas for the study of polysaccharide in vivo processes and immunomodulatory mechanisms.

Objective To study the bioequivalence and safety of two olmesartan medoxomil and hydrochlorothiazide tablets in Chinese healthy subjects.Methods A total of 24 healthy subjects underwent fasting and postprandial tests in a single-center,randomized,open-label,single-dose,two-formulation,two-sequence,two-period,self-cross-over controlled design.The subjects were administered a single oral dose of the test formulation and reference formulation(each containingolmesartan medoxomil 20 mg and hydrochlorothiazide 12.5 mg)in a random cross-over fashion.The plasma concentrations of olmesartan and hydrochlorothiazide were determined by LC-MS/MS.The non-compartmental model analysis of olmesartan and hydrochlorothiazide was conducted using WinNonlin 7.0 software to calculate pharmacokinetic parameters and assess bioequivalence.Results In the fasting test,the pharmacokinetic parameters of olmesartan of test and reference were as follows:Cmax were(798.35±206.78)and(664.52±168.25)ng·mL-1,AUC0-t were(4 430.71±1 294.87)and(3 976.67±1 083.54)h·ng·mL-1,AUC0-∞ were(4 551.67±1 303.06)and(4 090.37±1 103.97)h·ng·mL-1.The pharmacokinetic parameters of hydrochlorothiazide of test and reference were as follows:Cmax were(92.39±35.96)and(96.15±38.76)ng·mL-1,AUC0_t were(548.69±217.11)and(564.41±208.68)h·ng·mL-1,AUC0-∞ were(603.04±228.59)and(619.26±223.27)h·ng·mL-1.In the fed test,the pharmacokinetic parameters of olmesartan of T and R were as follows:Cmax were(583.15±149.48)and(550.57±104.76)ng·mL-1,AUC0-t were(3 585.18±952.72)and(3 292.19±904.58)h·ng·mL-1,AUC0-∞ were(3 696.05±996.55)and(3 396.30±923.41)h·ng·mL-1.The pharmacokinetic parameters of hydrochlorothiazide of test and reference were as follows:Cmax were(70.30±17.88)and(74.70±21.65)ng·mL-1,AUC0-t were(476.60±119.39)and(492.91±144.81)h·ng·mL-1,AUC0-∞ were(523.37±132.67)and(535.81±151.92)h·ng·mL-1.In fasting and fed condition,the 90％confidence interval(90％CI)of Cmax,AUC0-t and AUC0-∞ of olmesartan and hydrochlorothiazide were in 80.00％-125.00％.Conclusion The two olmesartan medoxomil and hydrochlorothiazide tablets were bioequivalent under fasting and fed conditions,and good security.

Natural products are important sources of drug discovery. However, the traditional methods of extraction and isolation, as well as chemical synthesis for obtaining natural products are associated with issues such as operational complexity, high costs, low efficiency, and environmental pollution. Constructing microbial cell factories through synthetic biology methods to produce medicinal natural products has the advantages of high efficiency, low cost, and environmental protection. Nevertheless, the scope and yield improvement of the products are limited by the limitations of enzymes in microbial cell factories. Protein engineering is considered one of the most effective approaches to overcome these limitations. This article introduces commonly used methods of protein engineering technology and summarizes its specific applications in improving enzyme performance, modifying the enzymatic environment, and promoting the development of synthetic biology tools in the field of pharmaceutical natural product synthesis. Furthermore, it analyzes the current bottlenecks and challenges in protein engineering and looks forward to its future application prospects, offering insights for the development and practical use of protein engineering technology.

Nicotinic acetylcholine receptors (nAChRs) belong to ligand-gated ion channel receptors, of which α7 nAChR subtype is widely distributed in the cerebral cortex, thalamus, hippocampus, and also identified in microglia, macrophages, bone marrow cells, etc. Previous studies revealed that α7 nAChR is closely related to the function of the cholinergic anti-inflammatory pathway, and is a vital target for drug development of Alzheimer's disease and schizophrenia. The establishment of a stable α7 nAChR in vitro drug screening system is crucial for the efficient screening of novel drugs targeting this target. Recombinant expression of different subtypes of nAChRs on Xenopus laevis oocyte membranes and current detected by two-electrode voltage clamp (TEVC) is an advanced and complex model for novel drug screening. Molecular chaperones can assist the assembly of some nAChR subunits to form functional receptors, providing a stable expression model for the screening of compounds targeting this receptor. In this study, a molecular chaperone gene of α7 nAChR, transmembrane protein 35A (Tmem35a), was isolated and cloned from rats. We constructed the recombinant expression vector and obtained the cRNA of Tmem35a by in vitro transcription technique. Two cRNAs (Tmem35a and α7) were mixed and injected into X. laevis oocytes for expression. Then, the effects of this molecular chaperone on the current expression and pharmacological properties of α7 nAChR were evaluated by the TEVC. The results revealed that TMEM35A, also known as novel acetylcholine receptor chaperone (NACHO) could effectively increase the expression of α7 nAChR protein on oocyte membranes, and the amount of α7 nAChR protein was increased about 1-fold. The peak current induced by agonist acetylcholine (ACh) was increased about 10-fold. After injection of Tmem35a cRNA, the median effect concentration (EC₅₀) value of α7 nAChR to agonist ACh is 228.5 μmol·L^-1, which shows almost no difference from native α7 nAChR (EC₅₀: 223.3 μmol·L^-1), indicating the preservation of the normal properties of α7 nAChR. The results of this investigation indicate that the molecular chaperone NACHO effectively assists the heterologous expression of α7 nAChR in X. laevis oocytes, which provides a model for screening the potency of lead compounds targeting α7 nAChR. All animal experiments in this study were reviewed and approved by the Ethics Committee of Guangxi University (approval number: GXU-2023-0249).

N-type voltage-gated calcium (Ca²⁺) channels (N-type VGCC, Ca_V2.2) mediate Ca²⁺ influx in response to action potential at the presynaptic terminal, and play an important role in synaptogenesis, neurotransmitter release and nociceptive signal transduction. It is a new target for the development of drugs for the treatment of neuralgia (chronic pain) and other major diseases. Due to the difficulty of calcium channel expression in vitro and the detection of channel current, there is a great lack of new drug screening models. In this study, we established and optimized the electrophysiological drug screening model using Xenopus laevis oocytes for the recombinant expression of Ca_V2.2 in vitro (this study were reviewed and approved by the Ethics Committee of Guangxi University, approval number: GXU-2023-0249). Firstly, the linear plasmids encoding cDNA of major subunit α1B and auxiliary subunits α2δ1 and β3 of rat Ca_V2.2 were used as templates for in vitro transcription to generate their related mRNA (cRNA), after which three kinds of cRNA were injected into Xenopus laevis oocytes at the mass ratio of 2∶1∶1 for expression. The two-electrode voltage clamp (TEVC) technique was used to detect the inward current produced by Ca_V2.2. At the same time, the expression conditions of Ca_V2.2 were optimized, and its gating function was characterized from the aspects of channel activation and inactivation. The results showed that 3-5 days after cRNA microinjection, stable Ca_V2.2-mediated barium ion (Ba²⁺) currents were successfully detected. The interference of endogenous potassium channels and Ca²⁺-activated chloride channels can be eliminated by tetraethylammonium hydroxide (TEAOH) and 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid tetrakis (BAPTA-AM) treatment. The maximum potential for Ca_V2.2 activation is 0 mV, and the current reverses to be outward when the membrane potential is greater than +50 mV. By fitting the steady-state activation and inactivation curves, the half-maximal activation potential and half-maximal inactivation potential of Ca_V2.2 are identified as -15.9 and -60.2 mV. In this study, a stable Ca_V2.2 expression system was established based on Xenopus laevis oocytes. The in vitro expression system can provide a new way for the screening of Ca_V2.2 active compounds or lead drugs.

Objective:To observe the changes in the nutritional status of pediatric patients after allogeneic hematopoietic stem cell transplantation(allo-HSCT)for one year,and to analyze the risk factors.Methods:We collected data from 88 pediatric patients who underwent allo-HSCT at the Department of Hematology and Oncology in Children's Hospital of Nanjing Medical University between May 2018 and November 2022.All pediatric patients underwent nutritional status analysis before transplantation,at enrollment,3 months,6 months and 1 year after allo-HSCT.Linear regression model was used to analyze the risk factors for growth rate.Results:The body mass index Z score(BMI-Z)before allo-HSCT was(0.096±1.349),and decreased to(-0.258±1.438)、(-0.715±1.432)、(-0.584±1.444)at enrollment,3 months,6 months after allo-HSCT,and(-0.130±1.317)at 1 year after allo-HSCT(P<0.001).There was no significant change in BMI-Z between pre-transplantation and 1 year after transplantation(P=1.000).Height for age Z score(HAZ)before transplantation was(0.137±1.305)and decreased to(-0.083±1.267)、(-0.221±1.299)、(-0.269±1.282)in 3 months,6 months and 1 year after allo-HSCT(P<0.001).Multivariate linear regression showed that age≥10 years old(P=0.015)and chronic graft-versus-host disease(cGVHD)(P=0.005)were independent risk factors for change in HAZ.Conclusion:The BMI-Z of pediatric patients treated with allo-HSCT returned to the pre-transplantation level after one year,while HAZ continued to decrease.Allo-HSCT may cause impaired growth rate in pediatric patients.Attention should be paid to HAZ changes in pediatric patients before and after allo-HSCT,especially in pediatric patients≥10 years old of age and those with cGVHD.Effective nutritional intervention should be provided in time.

Objective To investigate the clinical characteristics and prognosis of pneumococcal meningitis(PM),and drug sensitivity of Streptococcus pneumoniae(SP)isolates in Chinese children.Methods A retrospective analysis was conducted on clinical information,laboratory data,and microbiological data of 160 hospitalized children under 15 years old with PM from January 2019 to December 2020 in 33 tertiary hospitals across the country.Results Among the 160 children with PM,there were 103 males and 57 females.The age ranged from 15 days to 15 years,with 109 cases(68.1% )aged 3 months to under 3 years.SP strains were isolated from 95 cases(59.4% )in cerebrospinal fluid cultures and from 57 cases(35.6% )in blood cultures.The positive rates of SP detection by cerebrospinal fluid metagenomic next-generation sequencing and cerebrospinal fluid SP antigen testing were 40% (35/87)and 27% (21/78),respectively.Fifty-five cases(34.4% )had one or more risk factors for purulent meningitis,113 cases(70.6% )had one or more extra-cranial infectious foci,and 18 cases(11.3% )had underlying diseases.The most common clinical symptoms were fever(147 cases,91.9% ),followed by lethargy(98 cases,61.3% )and vomiting(61 cases,38.1% ).Sixty-nine cases(43.1% )experienced intracranial complications during hospitalization,with subdural effusion and/or empyema being the most common complication[43 cases(26.9% )],followed by hydrocephalus in 24 cases(15.0% ),brain abscess in 23 cases(14.4% ),and cerebral hemorrhage in 8 cases(5.0% ).Subdural effusion and/or empyema and hydrocephalus mainly occurred in children under 1 year old,with rates of 91% (39/43)and 83% (20/24),respectively.SP strains exhibited complete sensitivity to vancomycin(100% ,75/75),linezolid(100% ,56/56),and meropenem(100% ,6/6).High sensitivity rates were also observed for levofloxacin(81% ,22/27),moxifloxacin(82% ,14/17),rifampicin(96% ,25/26),and chloramphenicol(91% ,21/23).However,low sensitivity rates were found for penicillin(16% ,11/68)and clindamycin(6% ,1/17),and SP strains were completely resistant to erythromycin(100% ,31/31).The rates of discharge with cure and improvement were 22.5% (36/160)and 66.2% (106/160),respectively,while 18 cases(11.3% )had adverse outcomes.Conclusions Pediatric PM is more common in children aged 3 months to under 3 years.Intracranial complications are more frequently observed in children under 1 year old.Fever is the most common clinical manifestation of PM,and subdural effusion/emphysema and hydrocephalus are the most frequent complications.Non-culture detection methods for cerebrospinal fluid can improve pathogen detection rates.Adverse outcomes can be noted in more than 10% of PM cases.SP strains are high sensitivity to vancomycin,linezolid,meropenem,levofloxacin,moxifloxacin,rifampicin,and chloramphenicol.[Chinese Journal of Contemporary Pediatrics,2024,26(2):131-138]

Objective To investigate the clinical phenotypes and genotypes of children with congenital fibrinogen disorder(CFD).Methods A retrospective analysis was conducted on the clinical data of 16 children with CFD.Polymerase chain reaction was used to amplify all exons and flanking sequences of the FGA,FGB,and FGG genes,and sequencing was performed to analyze mutation characteristics.Results Among the 16 children,there were 9 boys(56%)and 7 girls(44%),with a median age of 4 years at the time of attending the hospital.Among these children,9(56%)attended the hospital due to bleeding events,and 7(44%)were diagnosed based on preoperative examination.The children with bleeding events had a significantly lower fibrinogen activity than those without bleeding events(P<0.05).Genetic testing was conducted on 12 children and revealed a total of 12 mutations,among which there were 4 novel mutations,i.e.,c.80T>C and c.1368delC in the FGA gene and c.1007T>A and C.1053C>A in the FGG gene.There were 2 cases of congenital afibrinogenemia caused by null mutations of the FGA gene,with relatively severe bleeding symptoms.There were 7 cases of congenital dysfibrinogenemia mainly caused by heterozygous missense mutations of the FGG and FGA genes,and their clinical phenotypes ranged from asymptomatic phenotype to varying degrees of bleeding.Conclusions The clinical phenotypes of children with CFD are heterogeneous,and the severity of bleeding is associated with the level of fibrinogen activity,but there is a weak association between clinical phenotype and genotype.

Objective To observe the effect of quercetin on mechanical allodynia,astrocyte activation,and upregulation of pain-related transient receptor potential vanilloid 1(TRPV1)and P2X purinoceptor 3(P2X3)in mice with paclitaxel-induced peripheral neuropathy.Methods Twenty-four C57BL/6 mice were divided randomly into control,model,and model+quercetin groups(n=8 mice per group).Paclitaxel(total dose 8 mg/kg)was injected intraperitoneally into mice in the model and model+quercetin groups to establish the model.Mice in the control group were injected intraperitoneally with the same volume of vehicle.On day 8 after the first injection,mice in the model+quercetin group were injected with 60 mg/kg quercetin solution orally and mice in the other groups were injected with the same volume of vehicle.Mechanical pain was measured by the von Frey test.Activation of astrocytes in the spinal dorsal horn was detected by immunofluorescence.Expression levels of TRPV1 and P2X3 in dorsal root ganglia were detected by immunofluorescence and Western Blot.Results(1)Compared with model group,the mechanical pain of mice in model+quercetin group were relieved.(2)Compared with model group,the activation of astrocytes and the expressions of TRPV1 and P2X3 in mice of model+quercetin group were alleviated(P＜0.05).Conclusions Quercetin can significantly reduce mechanical pain in mice with paclitaxel-induced peripheral neuropathy.This mechanism maybe related to alleviating the activation of astrocytes in the spinal dorsal horn and reducing expression of TRPV1 and P2X3 in the dorsal root ganglia.