Establishment of human cerebral organoid systems to model early neural development and assess the central neurotoxicity of environmental toxins

Human brain development is a complex process,and animal models often have significant limitations.To address this,researchers have developed pluripotent stem cell-derived three-dimensional structures,known as brain-like organoids,to more accurately model early human brain development and disease.To enable more consistent and intuitive reproduction of early brain development,in this study,we incorporated forebrain organoid culture technology into the traditional unguided method of brain organoid culture.This involved embedding organoids in matrigel for only 7 days during the rapid expansion phase of the neural epithelium and then removing them from the matrigel for further cultivation,resulting in a new type of human brain organoid system.This cerebral organoid system replicated the temporospatial characteristics of early human brain development,including neuroepithelium derivation,neural progenitor cell production and maintenance,neuron differentiation and migration,and cortical layer patterning and formation,providing more consistent and reproducible organoids for developmental modeling and toxicology testing.As a proof of concept,we applied the heavy metal cadmium to this newly improved organoid system to test whether it could be used to evaluate the neurotoxicity of environmental toxins.Brain organoids exposed to cadmium for 7 or 14 days manifested severe damage and abnormalities in their neurodevelopmental patterns,including bursts of cortical cell death and premature differentiation.Cadmium exposure caused progressive depletion of neural progenitor cells and loss of organoid integrity,accompanied by compensatory cell proliferation at ectopic locations.The convenience,flexibility,and controllability of this newly developed organoid platform make it a powerful and affordable alternative to animal models for use in neurodevelopmental,neurological,and neurotoxicological studies.

Botulinum toxin type A injection combined with biofeedback in the treatment of spastic pelvic floor syndrome

BACKGROUND Spastic pelvic floor syndrome(SPFS)is a refractory pelvic floor disease characterized by abnormal(uncoordinated)contractions of the external anal sphincter and puborectalis muscle during defecation,resulting in rectal emptation and obstructive constipation.The clinical manifestations of SPFS are mainly characterized by difficult defecation,often accompanied by a sense of anal blockage and drooping.Manual defecation is usually needed during defecation.From physical examination,it is commonly observed that the patient's anal muscle tension is high,and it is difficult or even impossible to enter with his fingers.AIM To investigate the characteristics of anorectal pressure and botulinum toxin A injection combined with biofeedback in treating pelvic floor muscle spasm syndrome.METHODS Retrospective analysis of 50 patients diagnosed with pelvic floor spasm syndrome.All patients underwent pelvic floor surface electromyography assessment,anorectal dynamics examination,botulinum toxin type A injection 100 U intramuscular injection,and two cycles of biofeedback therapy.RESULTS After the botulinum toxin A injection combined with two cycles of biofeedback therapy,the patient's postoperative resting and systolic blood pressure were significantly lower than before surgery(P<0.05).Moreover,the electromyography index of the patients in the resting stage and post-resting stages was significantly lower than before surgery(P<0.05).CONCLUSION Botulinum toxin A injection combined with biofeedback can significantly reduce pelvic floor muscle tension in treating pelvic floor muscle spasm syndrome.Anorectal manometry is an effective method to evaluate the efficacy of treatment objectively.However,randomized controlled trials are needed.

Botulinum toxin type A in treating early-stage patients with small-angle acute acquired comitant esotropia

AIM:To investigate botulinum toxin A(BTXA)efficacy on small-angle(≤25Δ)acute acquired concomitant esotropia(AACE)in early-stage patients.METHODS:The electronic medical record data of AACE patients during March 2019 and June 2023 were collected in this retrospective and hospital-based cohort study.A total of 72 small-angle AACE patients received BTXA extraocular muscle injection.Patients were grouped by onset-to-treatment time(Group A:≤6mo,Group B:>6mo).Deviation of esotropia,eye alignment and stereopsis were analyzed at the period of pre/post-injection(1wk,1,3,and 6mo).Orthophoria rate at 6mo(horizontal deviation<10Δand binocular single vision)were considered as outcome index.RESULTS:There were no significant baseline differences(P>0.05)between two groups except onset-to-treatment time(2mo vs 11mo,P<0.001).Higher orthophoria rates were in Group A at last follow-up(94.74%vs 73.53%,P=0.013).Post-BTXA deviations of two groups at 1mo showed no difference(P>0.05);while in 3 and 6mo Group A was significantly smaller than group B(all P<0.001).No statistically significant differences were observed among all post-BTXA deviations of near and distance in Group A.In Group B,deviation at 3mo(near:2Δvs 0,P<0.001;distance:4Δvs 0,P<0.001)and 6mo(near:6Δvs 0,P<0.001;distance:6Δvs 0,P<0.001)was significant increased compared to deviation at 1wk after treatment.Group A showed better stereopsis recovery in last follow-up compared to Group B(80″vs 200″,P=0.002).Both groups obtained improved stereopsis after treatment(Group A:80″vs 300″,P<0.001;Group B:200″vs 300″,P=0.037).CONCLUSION:BTXA is effective for AACE with small deviation(≤25Δ)in early stage.Delayed treatment(>6mo)may reduce BTXA efficacy.Early BTXA intervention benefits long-term eye alignment and stereopsis recovery.

Botulinum toxin type A-targeted SPP1 contributes to neuropathic pain by the activation of microglia pyroptosis

BACKGROUND Neuropathic pain(NP)is the primary symptom of various neurological condi-tions.Patients with NP often experience mood disorders,particularly depression and anxiety,that can severely affect their normal lives.Microglial cells are as-sociated with NP.Excessive inflammatory responses,especially the secretion of large amounts of pro-inflammatory cytokines,ultimately lead to neuroinflam-mation.Microglial pyroptosis is a newly discovered form of inflammatory cell death associated with immune responses and inflammation-related diseases of the central nervous system.METHODS Two models,an in vitro lipopolysaccharide(LPS)-stimulated microglial cell model and a selective nerve injury model using BTX-A and SPP1 knockdown treatments,were used.Key proteins in the pyroptosis signaling pathway,NLRP3-GSDMD,were assessed using western blotting,real-time quantitative polymerase chain reaction,and immunofluorescence.Inflammatory factors[interleukin(IL)-6,IL-1β,and tumor necrosis factor(TNF)-α]were assessed using enzyme-linked immuno-sorbent assay.We also evaluated microglial cell proliferation and apoptosis.Furthermore,we measured pain sensation by assessing the delayed hind paw withdrawal latency using thermal stimulation.RESULTS The expression levels of ACS and GSDMD-N and the mRNA expression of TNF-α,IL-6,and IL-1βwere enhanced in LPS-treated microglia.Furthermore,SPP1 expression was also induced in LPS-treated microglia.Notably,BTX-A inhibited SPP1 mRNA and protein expression in the LPS-treated microglia.Additionally,depletion of SPP1 or BTX-A inhibited cell viability and induced apoptosis in LPS-treated microglia,whereas co-treatment with BTX-A enhanced the effect of SPP1 short hairpin(sh)RNA in LPS-treated microglia.Finally,SPP1 depletion or BTX-A treatment reduced the levels of GSDMD-N,NLPRP3,and ASC and suppressed the production of inflammatory factors.CONCLUSION Notably,BTX-A therapy and SPP1 shRNA enhance microglial proliferation and apoptosis and inhibit microglial death.It improves pain perception and inhibits microglial activation in rats with selective nerve pain.

Dermal thickness,rather than drug concentration and injection speed,influences the effective area of botulinum toxin type A in the dermis

Background:Recently,microbotulinum,a new technique that involves injecting botulinum toxin type A(BoNTA)microdroplets into superficial cutaneous tissue,has gained popularity.The precise distribution of BoNTA in the targeted area profoundly affects outcomes.Many factors may influence the effective area of BoNTA in the dermis.This study aimed to determine the dermal distribution properties of BoNTA to guide microbotulinum injection.Methods:Ten healthy males aged 18–65 years without BoNTA treatment in the previous year were recruited to receive intradermal injections in the chest and back.Ultrasound was used to ensure the intradermal delivery of injections and measure the dermal thickness.The minor iodine starch test was performed at baseline and 3 days,7 days,21 days,1 month,and 2 months after treatment.Results:All participants received intradermal injections.The dermis was thinner on the chest(thickness,0.20±0.03 cm)than on the back(thickness,0.39±0.07 cm)(P<0.05).An injection in the thicker dermis had a significantly smaller effective area at every follow-up visit.The drug concentration did not affect the effective area except at 3 days after treatment.Injection speed did not influence the effective area at any follow-up visits.Conclusion:An injection in a thicker dermis leads to a smaller effective area for intradermal injections.When the BoNTA dose is the same,the drug concentration and injection speed do not matter.

Clinical effect of botulinum toxin type A combined with autologous fat grafting in patients with nasolabial fold depression

BACKGROUND Nasolabial fold(NLF)depression can affect the facial appearance of patients to some extent and increase their psychological burdens.In recent years,autologous fat grafting(AFG)combined with botulinum toxin A(BTX-A)injection(AFG+BTX-A injection)has been gradually applied in the treatment of patients with NLF depression.Although studies have been conducted on the efficacy and safety of AFG+BTX-A injection in treating NLF depression,the experimental design,observational indicators,and sample enrollment criteria vary remarkably,making it difficult to draw convincing and consistent conclusions.Thus,further relevant research is warranted.AIM To assess the esthetic improvement,efficacy,and safety of AFG+BTX-A injections in patients with NLF depression.METHODS This study included 60 patients with NLF depression who were treated in our hospital from February 2019 to April 2021.These patients were categorized into control(n=30)and observation(n=30)groups.The observation group received AFG+BTX-A injection,whereas the control group underwent AFG only.All patients were evaluated using the wrinkle severity rating scale(WSRS)and global aesthetic improvement scale.The compactness of facial contours,skin evaluation indexes,adverse reactions,and satisfaction of the two groups were evaluated 3 months postoperatively.RESULTS The WSRS scores of the observation group at 1,3,and 6 months postoperatively were lower than those of the control group(P<0.05).Three months postoperatively,facial fine lines and pores showed obvious improvement and the skin index score was higher in the observation group than in the control group(P<0.05).The compactness of facial contours was better in the observation group than in the control group(P<0.05).In addition,no remarkable differences were noted in the incidence of postoperative adverse reactions such as facial stiffness,facial asymmetry,facial bruising,and facial concavity inequality(P>0.05).CONCLUSION AFG+BTX-A injection is a highly safe,cost-effective,effective,and long-lasting treatment for NLF depression with high esthetic value,which should be promoted in the future.

Betulinic acid protects against ovarian impairment by decreasing F-2 toxin-induced oxidative stress and inflammation associated with the downregulation of p38 expression in mice

F-2 toxin is an estrogenic mycotoxin that causes reproductive disorders in animals.Betulinic acid(BA)is a natural pentacyclic lupane-structure triterpenoid that has diverse pharmacological activities.In this study,the antioxidative and anti-inflammatory effects of BA and its underlying mechanism are explored in F-2 toxin-triggered mouse ovarian damage.We found that BA alleviated the F-2 toxin-induced ovarian impairment by stimulating follicle growth,reducing inflammatory cell infiltration,repairing damaged mitochondria and endoplasmic reticulum.Simultaneously,BA not only reversed F-2 toxin-induced reduction of follicle stimulating hormone(FSH)and luteinizing hormone(LH)levels in the serum,but also restrained the protein expression of the estrogen receptors a(ERa)and ERβ.Moreover,BA restored the balance of F-2 toxin-induced ovarian redox system disorders.Subsequently,we found that 0.25 mg/kg BA played an anti-inflammatory role in the F-2 toxin-induced ovarian impairment by decreasing interleukin-1β(IL-1β).IL-6,and tumor necrosis factor-α(TNF-α)mRNA expression,as well as inhibiting p38 protein expression.These data demonstrated that BA exerts its protective effect on F-2 toxin-induced ovarian oxidative impairment and inflammation by inhibiting p38 expression,which implies a natural product-based medicine to ameliorate F-2 toxin-caused female reproductive toxicity and provides a detoxifying method for food contaminated by mycotoxin.

Botulinum toxin type A for treating chronic low back pain:A double blinded randomized control study

BACKGROUND Low back pain(LBP)is a prevalent issue that orthopedic surgeons frequently address in the outpatient setting.LBP can arise from various causes,with stiffness in the paraspinal muscles being a notable contributor.The administration of Botulinum toxin type A(BoNT-A)has been found to alleviate back pain by relaxing these stiff muscles.While BoNT-A is approved for use in numerous conditions,a limited number of randomized clinical trials(RCTs)validate its efficacy specifically for treating LBP.AIM To study the safety and the efficacy of BoNT-A in minimizing pain and improving functional outcomes in patients of chronic LBP(CLBP).METHODS In this RCT,adults aged 18-60 years with mechanical LBP persisting for at least six months were enrolled.Participants were allocated to either the Drug group,receiving 200 Ipsen Units(2 mL)of BoNT-A,or the Control group,which received a 2 mL placebo.Over a 2-month follow-up period,both groups were assessed using the Visual Analog Scale(VAS)for pain intensity and the Oswestry Disability Index(ODI)for disability at the start and conclusion of the study.A decrease in pain by 50%was deemed clinically significant.RESULTS The study followed 40 patients for two months,with 20 in each group.A clinically significant reduction in pain was observed in 36 participants.There was a statistically significant decrease in both VAS and ODI scores in the groups at the end of two months.Nonetheless,when comparing the mean score changes,only the reduction in ODI scores(15 in the placebo group vs 16.5 in the drug group,clinically insignificant)was statistically significant(P=0.012),whereas the change in mean VAS scores was not significant(P=0.45).CONCLUSION The study concludes that BoNT-A does not offer a short-term advantage over placebo in reducing pain or improving LBP scores in CLBP patients.

Severe Botulism after Intragastric Botulinum Toxin-A Injection: A Case Series

Intragastric botulismus toxin-A (BoNT-A) is one of the new approaches in the treatment of obesity. We aimed to contribute to the literature by presenting the clinical features, laboratory findings and treatment responses of iatrogenic botulism cases due to intragastric BoNT-A administered in our clinic. All detailed medical information was obtained by accessing the medical records of the patients who were hospitalized and followed up and treated between September 2022 and December 2022, and the diagnosis of A.05.1 Botulism was entered according to ICD-10, and whose clinical findings were compatible with botulism disease and who underwent intragastric BoNT-A application beforehand. These records were obtained by examining this information. 10 patients who developed botulism after intragastric BoNT-A application between 01/09/2022 and 28/02/2023 were followed up in our clinic. All of the patients were women. The mean age was 35. The mean hospital stay was 9 days. Only 1 of our cases required intensive care. Good response to treatment was accepted as a complete or near-complete improvement in the clinical findings of the patients and all of them had a good response to treatment. Intragastric BoNT-A administration is a procedure that requires careful indication with a profit/loss calculation considering the potential side effects. In addition, attention should be paid to dilution rates and dose amounts.

Clinical experience of professor LI Xiuhui in treating acquired immune deficiency syndrome(AIDS)complicated with opportunistic infections using the methodology of “turbid toxins entering the blood and expelling pathogens outwardly”

This paper summarized professor LI Xiuhui's experience in treating acquired immune deficiency syndrome(AIDS) complicated with opportunistic infections(OIs) using the methodology of “turbid toxins entering the blood and expelling pathogens outwardly”. OIs are significant cause of morbidity and mortality among AIDS patients. Professor LI Xiuhui believes that the pathogenesis of OIs lies in turbid toxins entering the blood, infecting the Sanjiao, damaging the nutrient Qi and defensive Qi, consuming Qi and essence, and impairing the primordial Qi. As a result, the five organs are weakened, pathogenic toxins overflow, leading to the occurrence of some related opportunistic infectious diseases in various systems throughout the body. Therefore, in treatment, the “penetrating and supporting method” and the “tonifying and supporting method” are used to consolidate and support the healthy Qi, allowing the pathogenic toxins to be expelled smoothly,so that the opportunistic infectious diseases can be cured or controlled.

齐元富基于“解毒”治疗观辨治肺癌经验

齐元富教授重视毒邪在肺癌发生、发展中的重要作用,“解毒”是其治疗肺癌的经验特色之一。齐教授将导致肺癌的毒邪分为热毒、郁毒、痰毒、瘀毒四种类型,热毒者主以清热解毒治之,郁毒者主以理气消癥治之,痰毒者主以化痰除湿治之,瘀毒者主以活血散结治之,临床常获佳效。附验案1则。

犬粮食品生物安全风险分析

近些年,宠物狗的食品营养品质与安全受到重视。然而,犬粮安全问题时有发生,尤其是微生物方面,引起了宠物行业和养宠爱好者的高度关注。为全面了解犬粮的质量和安全性,本试验对市场上的四种主粮食品(膨化粮、鲜肉粮、低温烘焙粮和益生菌粮)进行了生物安全指标分析,包括重金属、微生物数量、有害病原菌、生物胺、内毒素和真菌毒素等。研究结果显示:四种主粮食品的重金属、细菌总数、有害病原菌和真菌毒素都符合全价宠物食品犬粮GB/T31216-2014的限量标准,但多数样本检测出呕吐毒素。不同类型犬粮均检测出生物胺和内毒素,生产工艺对该方面的指标有一定影响,尤其是低温烘焙粮和益生菌粮,这些指标需引起高度重视。通过对生物安全指标进行分析发现,微生物产生的内毒素、生物胺和真菌毒素是犬粮食品潜在的安全风险。本研究为行业的健康发展和消费者获取高品质、安全的犬粮提供了指导。

基于FAERS数据库的A型肉毒毒素药品不良事件信号挖掘与分析

目的:基于美国FDA不良事件报告系统(FDA adverse event reporting system,FAERS)数据库挖掘A型肉毒毒素的药品不良事件(Adverse drug event,ADE)信号,为临床安全用药提供参考。方法:收集FAERS数据库2004年1月-2023年9月的A型肉毒毒素ADE数据,采用比例失衡法和贝叶斯法对相关ADE进行信号挖掘。结果:共获得目标药物A型肉毒毒素相关ADE报告162809例次。共挖掘出ADE信号496个,筛选同时符合4种算法,并排除无关信号,最终获得ADE信号209个。其中未在我国现有药品说明书中提及的新信号有7个,包括斜视、流涎、咀嚼疾病、牙关紧闭、口腔感觉减退、唇病变、尿潴留。结论:A型肉毒毒素使用过程中,应加强常见ADE监测,更加关注药品说明书未列入的ADE。

超高效液相色谱-串联质谱法测定发酵乳制品中米酵菌酸和异米酵菌酸

该研究采用液液萃取技术结合超高效液相色谱-串联质谱法对发酵乳制品中的米酵菌酸和异米酵菌酸两种细菌毒素进行监测分析,以防控细菌毒素中毒事件的发生。以发酵乳制品为基质,通过考察提取试剂、净化剂和盐析剂以及仪器参数对两种细菌毒素测定效果的影响,确定前处理条件为采用90%丙酮-1%甲酸溶液涡旋提取,高速离心浓缩,经0.22μm滤膜过滤后进行检测。在最佳条件下,米酵菌酸和异米酵菌酸在1~200 ng/mL范围内线性关系良好,相关系数(r)均大于0.999,检出限分别为0.075、0.11μg/kg,在3个加标水平下的回收率为90.8%~106%,相对标准偏差为0.80%~6.1%。该方法相较于其他方法更高效便捷,且无需前处理净化操作,展现了更佳的提取率、更高的灵敏度及更强的准确性,适用于发酵乳制品尤其是批量样品中米酵菌酸和异米酵菌酸的测定。

A型肉毒素联合脉冲染料激光预防颌面部手术切口瘢痕增生的效果观察

目的:探讨A型肉毒素联合脉冲染料激光预防颌面部手术切口瘢痕增生的效果。方法:选择2019年8月—2022年12月联勤保障部队第904医院口腔科收治的接受颌面部手术的患者92例,采用随机数字表法分为试验组(n=46)和对照组(n=46)。试验组采用A型肉毒素联合脉冲染料激光(pulsed dye laser,PDL)预防手术切口瘢痕增生,对照组仅采用A型肉毒素。比较2组患者的临床疗效、瘢痕情况、患者满意度及不良反应。采用SPSS 22.0软件包对数据进行统计学分析。结果:试验组临床总有效率为84.78%,显著高于对照组的63.04%(P<0.05)。2组治疗前瘢痕颜色、平整度、弹性程度、瘢痕宽度评分等无统计学差异(P>0.05),2组治疗完成1周后瘢痕颜色、平整度、弹性程度、瘢痕宽度评分均显著低于治疗前,且试验组显著低于对照组(P<0.05)。试验组总体满意度显著高于对照组(P<0.05)。试验组与对照组减张缝合情况、伤口位于瘢痕增生好发部位情况与存在瘢痕张力情况比较,差异无统计学意义(P>0.05)。2组治疗后不良反应发生率无统计学差异(P>0.05)。结论:A型肉毒素联合脉冲染料激光预防颌面部手术切口瘢痕增生的效果较好,安全性高,可在临床上推广使用。

Increase of β -1, 3-Glucanase and Chitinase Activities in Cotton Callus Cells Treated by Salicylic Acid and Toxin of Verticillium dahliae

The different resistance of cotton (Gossypium hirsutum L.) cultivars to crude toxin of Verticillium dah/iae(VD) was correlated with the activities of chitinase and β-1, 3-glucanase in callus cells. The activities of chitinase and β-1, 3-glucanase in the callus cells treated with the VD-toxin were increased to the higher level at earlier time point in resistant cultivars than these in the susceptible cultivars. Exogenous salicylic acid (SA) induced the accumulation of chitinase and β -1,3-glucanase, which resulted in the resistance of callus cells to the VD. toxin. Western blot using a polyclonal antibody against β -1,3-glucanase identified 28 kD protein that was induced by VD-toxin, SA, or VD-toxin plus SA.

Preliminary Study on the Extraction of Crude Toxin of Rhizoctonia solani and Its Activity

[ Objective] This study was to investigate the pathogenic mechanism of rice sheath blight pathogen （ Rhizoctonia solani） and the bioactive components of toxin. [ Method ] Rice sheath blight pathogen was cultured in the improved Richared medium; the culture filtrate was centrifuged and sterilized, then treated by activated carbon adsorption chromatography, distilled with methanol or water, and all were next concentrated, yielding the crude extracts of culture solution, crude extracts of methanol and crude extracts of water; the activities of these three extracts were determined, [ Result] The three extracts were russet pastes; activity determination showed that they had remarkable inhibitory effects on the growth of rice radicle and plantule, as well as the growth of four-foliage-young seedlings. They could also generate toxic effects on abscisic foliages and spots similar to the symptoms of sheath blight pathogen. [ Conclusion] Bioactive components of rice sheath blight pathogen toxin may be composed of various ingredients.

A型肉毒毒素注射治疗丘脑痛11例体会

目的:观察A型肉毒毒素注射对丘脑痛的疗效和安全性。方法:11例丘脑痛患者入组。在标记的受累部位一次性注射A型肉毒毒素50~400 U,注射后随访12个月。分别在注射前、注射后1周以及注射后12个月内每月采用VAS评分评估疼痛程度,治疗后4个月进行患者总体感觉改善情况评分(PGIC评分),记录治疗和随访期间的副作用。结果:11例患者中9例完成随访,1例在治疗后4个月失访,1例在治疗后8个月效果下降,自行使用其他药物治疗。9例中男7例,女2例,年龄52~82(68.3±10.8)岁。疼痛持续时间(13.3±3.7)个月,治疗前VAS评分(5.7±0.5)分,治疗后1周VAS评分均值降至2分,说明患者疼痛大为缓解,治疗8个月以后部分患者疗效下降,但治疗后12个月中,总体镇痛效果维持在较低水平(均值1.9~2.8),且较为稳定。根据PGIC评分,7例明显好转,2例轻微好转。注射后1周内1例出现面部不对称和眼睑下垂,1例出现面部不对称,均在5周内自行消失。结论:A型肉毒毒素注射治疗丘脑痛有效且安全。

产气荚膜梭菌Alpha毒素突变体的表达及单克隆抗体制备

[目的]获得产气荚膜梭菌Alpha毒素(Clostridium perfringens alpha-toxin, CPA)的重组突变体,评价其毒力和抗原性,进而制备针对CPA的单克隆抗体,并评价单克隆抗体特性。[方法]通过人工合成含6个氨基酸突变(第56和130位的天冬氨酸突变为甘氨酸、第275、307和331位的酪氨酸突变为苯丙氨酸、第336位的天冬氨酸突变为天冬酰胺)的CPA基因片段,并将其克隆至pET-30a(+)载体,转化大肠杆菌BL21(DE3)感受态细胞进行诱导表达与纯化,获得重组蛋白rCPA_(m6),并检测其毒力与免疫原性。将rCPA_(m6)作为包被抗原建立CPA抗体的间接ELISA检测方法,并用灭活的天然CPA作为免疫原按照常规方法免疫BALB/c小鼠,制备单克隆抗体,对其功能进行鉴定。[结果]重组蛋白rCPA_(m6)在大肠杆菌BL21(DE3)感受态中能够以可溶性和包涵体两种形式表达。毒力测定结果显示,100μg/只rCPA_(m6)攻毒后,小鼠全部存活。免疫原性分析结果显示,1×最小致死量(MLD)的天然CPA攻毒后,对照组小鼠全部死亡,10和20μg/只rCPA_(m6)免疫组小鼠存活率为100%。利用rCPA_(m6)成功建立了CPA抗体的间接ELISA检测方法,并筛选获得4株分泌抗CPA的单克隆抗体杂交瘤细胞株,分别命名为6E3、6B8、10A11、13D10,且4种细胞上清抗体效价均≥1∶3 200,其中单克隆抗体6B8细胞上清能中和天然CPA,且能与rCPA_(m6)发生反应。[结论]试验成功获得具有良好的安全性和免疫原性的重组蛋白rCPA_(m6),制备的CPA单克隆抗体6B8具有一定的中和活性及较高的特异性和敏感性。研究结果为CPA亚单位疫苗的研制提供了候选抗原,同时为CPA中毒症的治疗以及抗原/抗体检测方法的建立提供了物质基础。

金黄色葡萄球菌α-toxin(Hla)促进皮肤组织中IL-19表达上调的作用机制研究

目的探究金黄色葡萄球菌α-toxin(Hla)促进皮肤组织中IL-19表达上调的作用机制。方法采用WT S.Aureus、△Hla S.aureus(Hla缺失菌株)以及PBS感染Balb/c小鼠背部皮肤,收集感染后第1、3、7天的皮肤组织,HE染色检测组织炎性病理损伤,q RT-PCR和ELISA分别检测IL-19、IL-1β的m RNA和蛋白水平的表达。分离小鼠骨髓的中性粒细胞,分别用WT S.Aureus、△Hla S.aureus以及meida(不含菌液的培养基)刺激6 h后,q RT-PCR、ELISA和Western blot检测IL-1β的表达。不同浓度IL-1β刺激角质形成细胞PAM 2-12后,q RT-PCR和ELISA分别检测IL-19的表达。结果△Hla S.aureus组与WT S.aureus组相比,其皮肤损伤的面积减小,炎性细胞浸润和脓肿形成减少。同时q RT-PCR和ELISA检测发现,△Hla S.aureus组与WT S.aureus组相比,IL-19的m RNA和蛋白表达水平显著降低(P<0.01)。体外中性粒细胞刺激发现,△Hla S.aureus组与WTS.aureus组相比,IL-1β蛋白表达水平显著降低(P<0.01)。体外IL-1β刺激角质形成细胞PAM 2-12发现,与不刺激组相比,IL-19的m RNA和蛋白表达水平显著增加(P<0.01),并呈剂量依赖性。结论金黄色葡萄球菌分泌的α-toxin能够作用于中性粒细胞,促进了IL-1β的表达,IL-1β的过表达作用于皮肤的角质形成细胞,从而促进了IL-19的上调,可能参与了银屑病的发生与发展。