9V型肺炎球菌疫苗中多糖含量微孔板蒽酮-硫酸检测方法的建立及验证

目的建立微孔板蒽酮-硫酸法检测9V型肺炎球菌疫苗中多糖含量的检测方法,并对其进行验证和初步应用。方法通过对蒽酮-硫酸方法的改进,建立检测9V型肺炎球菌疫苗中多糖含量稳定可靠的微孔板蒽酮-硫酸法。分别对蒽酮-硫酸法中硫酸溶液浓度、加热时间进行优化,并对建立的方法进行特异性、线性、精密度及准确度的验证。结果最佳硫酸溶液比例为6∶1(浓硫酸∶水),最佳加热时间为10 min。在检测9V型肺炎球菌多糖、多糖衍生物及多糖蛋白结合物中多糖含量时,此方法特异性强;在20~120μg/m L范围内,标准曲线线性良好(r20.995);实验内及实验间均具有良好的精密度(CV值分别为2.92%~3.32%和3.10%~4.06%);准确度试验中3个质量浓度的回收率均在96.17%~106.63%之间。结论微孔板蒽酮-硫酸法可被用来有效、准确、稳定地检测9V型肺炎球菌多糖、多糖衍生物及多糖蛋白结合物中多糖的含量,该方法较传统蒽酮-硫酸法操作简便快捷,节约样品、试剂等材料,非常适用于相关的疫苗生产过程中的质量控制。     

7F型肺炎链球菌多糖竞争ELISA检测方法的建立

目的:建立检测7F型肺炎链球菌荚膜多糖的方法(enzyme-linked immunosorbent assay,ELISA),检测发酵过程中多糖的浓度。方法:包被物为7F型肺炎链球菌多糖,竞争物为待测多糖,建立间接竞争ELISA方法,并验证其准确性和精密度。结果:最佳多糖包被质量浓度为2.5ug/ml,多糖抗体血清稀释度为1:8×104。在检测范围为2.5~30μg/m L时呈线性相关,7F的最低检测限为1.5μg/m L。回归方程为B/B0=-0.4075 Pn7F+0.7632,R2=0.9952.样品加标回收率为95.13%-105%。结论:本研究新建的ELISA方法准确性和精密度较好,能特异性地检测7F型肺炎球菌多糖。     

人血清中肺炎链球菌荚膜多糖IgG抗体定量ELISA的初步验证

目的对肺炎链球菌荚膜多糖Ig G抗体定量ELISA,用于人血清中12F、19A、22F及33F型Ig G抗体的检测进行初步验证。方法以不同生产企业相同型别的12F、19A、22F及33F型荚膜多糖为包被抗原,用肺炎链球菌荚膜多糖Ig G抗体定量ELISA,对人血清中12F、19A、22F及33F型Ig G抗体进行定量检测,并对该方法的线性、检测限、检测范围、准确度、精密度、特异性进行初步验证。结果该方法检测13份质控血清的12F、19A、22F及33F型Ig G抗体的范围分别是0.02~4.38 ng/m L、0.14~34.68 ng/m L、0.10~25.20 ng/m L和0.12~29.78 ng/m L,r2均0.99,最低检测限分别为0.35 ng/m L、0.37 ng/m L、0.44 ng/m L和0.88 ng/m L。准确度为71.15%;试验间CV值均20%;特异性均85%。结论肺炎链球菌荚膜多糖Ig G抗体定量ELISA,用于人血清中12F、19A、22F及33F型Ig G抗体的检测,需对准确度、精密度和特异性进一步验证。     

B群链球菌的培养及优化研究

为了研究B群链球菌的生长和荚膜多糖的合成规律,采用摇瓶试验,探讨不同的液体培养基、培养基的pH值、葡萄糖的含量、生长因子、种子菌的接种量和溶氧等因素对B群链球菌生长的影响,优化发酵参数。并放大到10 L发酵罐中培养,菌浓度最高可达到20亿/mL;荚膜多糖的含量在培养的5 h达到652μg/mL。经过多次试验,建立了稳定的GBS发酵工艺。     

肺炎链球菌5型发酵工艺的优化

目的:采用正交试验设计方法进行肺炎链球菌5型发酵工艺的研究。方法:根据正交试验设计表L9(34)设计的试验条件组合进行了9次肺炎链球菌5型的发酵,采用70升发酵罐进行发酵工艺的摸索,提取了肺炎链球菌5型荚膜多糖粗糖。结果:最佳的发酵培养条件组合为温度37℃、葡萄糖20克/升、大豆胨15克/升、pH值7.3,最佳的纯化条件组合为冷酚抽提三次、沉核酸乙醇浓度23%、超滤膜孔径50kD、最终沉糖乙醇浓度60%,在此筛选得到的最佳条件下,连续进行了5个批次肺炎链球菌5型的发酵与荚膜多糖提取,荚膜多糖粗糖的平均收率为808.6mg/L,相对标准偏差为3.84%。结论:上述发酵培养条件组合适合用于肺炎多糖疫苗的研究和生产。     

肺炎链球菌C多糖含量检测方法的建立

目的使用肺炎链球菌C多糖单克隆抗体(单抗),建立检测荚膜多糖中残留的C多糖含量的方法。方法选择BALB/c雌性小鼠,采用体内诱生单抗腹水,放大生产肺炎链球菌C多糖单抗;使用间接ELISA、抑制性ELISA对其进行特异性鉴定;用特异性和亲和力高的单抗尝试建立肺炎链球菌荚膜多糖中C多糖含量检测的速率比浊法,并对该方法的线性、精密度、特异性进行验证。结果所制4株单抗的抗体类别均为IgM,识别的抗原表位互不相同,亲和力也不同。间接ELISA、抑制性ELISA结果均显示,所获得的单抗能够作用于肺炎链球菌C多糖上的磷酸胆碱位点,具有很好的特异性。选择单抗E8建立速率比浊检测方法的线性、精密度和特异性均良好,检测结果表明肺炎链球菌23个血清型荚膜多糖中C多糖含量不同。结论利用单抗建立了检测肺炎链球菌荚膜多糖中残留的C多糖的含量的速率比浊法。     

基于微孔板比色法的总糖含量测定方法的建立及应用

采用单因素试验和响应面优化法研究了微孔板法高通量检测总糖含量的方法,并进行了方法学考察,研究了不同离子、氨基酸和蛋白质等对该方法测定的影响。并以微生物多糖、枸杞多糖、可溶性淀粉和多种单糖为试受对象,与传统在比色管中的硫酸蒽酮比色法和苯酚硫酸比色法测定结果进行了比较。结果表明,反应体系总体积为230μL,其中150μL浓硫酸,30μL 5%苯酚水溶液,在85℃水浴20 min,在此条件下,在490 nm处的光吸收值与葡萄糖浓度呈线性相关,拟合线性回归方程相关系数R2为0.994 1,线性范围为10~100 nmol/well。该方法相对标准偏差为0.4%,加标回收率在102.7%~104.10%之间。精密度试验、稳定性试验和干扰性试验进一步说明此方法简便快捷、准确可靠、干扰性小,能应用于总糖含量的高效测定。     

根据年龄校正的D-二聚体临界值标准对急性肺栓塞的诊断价值

目的:探讨根据年龄校正的D-二聚体临界值标准对急性肺栓塞的诊断价值。方法:采用CT肺血管造影(CTPA)对367例疑似APE患者进行诊断,并采用酶联免疫吸附法(ELISA)检测患者的D-二聚体浓度,比较传统临界值标准(500μg/L)和根据年龄校正的临界值标准[(年龄×10)μg/L]对诊断APE的敏感度、特异性、符合率、阳性预测值和阴性预测值。结果:367例疑似APE患者中,共确诊64例,检出率为17.4%。APE患者的D-二聚体浓度为(2108.5±335.9)μg/L,显著高于非APE患者D-二聚体浓度(486.8±65.2)μg/L(t=27.61,P0.05);年龄≥60岁的APE患者D-二聚体浓度为(2931.8±509.4)μg/L,显著高于年龄60岁的APE患者D-二聚体浓度(1806.1±319.6)μg/L(t=10.77,P0.05)。根据年龄校正的D-二聚体临界值诊断APE的特异度、符合率、阳性预测值及曲线下面积(AUC)较传统D-二聚体临界值显著升高(P0.05);两种临界值的灵敏度、阴性预测值比较差异无统计学意义(P0.05)。结论:D-二聚体的浓度随年龄增加而增高,根据年龄校正的D-二聚体临界值标准可提高其对APE的诊断效率,减少漏诊,尤其适用于50岁以上人群。     

钙调蛋白磷酸酶B亚基生物学活性检测方法建立

建立钙调蛋白磷酸酶B亚基(calcineurin subunit B,CNB)生物活性检定方法用以质量控制.CNB能促进钙调蛋白磷酸酶A亚基(CNA)的突变体CNAΔ316的活性,增强其分解底物对硝基苯磷酸二钠(p-nitrophenylphosphate,p NPP)的能力.采用四参数方程对不同浓度CNB和相应的p NPP最大分解速率进行拟合,用平行线分析法对供试品和参考品进行量值传递,得到供试品的活性值.然后对该方法的准确度、精密度、线性、线性范围、灵敏度、特异性和耐久性进行验证.回收率结果均在98%以上,板内精密度为6.7%,板间精密度为10.8%,决定系数大于0.98,线性范围为0.05~50μg/m L,灵敏度为50μg/m L.部分细胞因子无法促进CNAΔ316分解底物p NPP的能力.在一定范围内,CNAΔ316浓度对检测结果没有影响.     

基于质量源于设计理念在伤寒沙门菌中试规模培养工艺放大中的应用

目的基于质量源于设计(quality by design, QbD)理念,确定伤寒沙门菌(Salmonella typhi)中试规模(200 L)的培养工艺。方法运用QbD通过分析伤寒沙门菌培养工艺核心指标、培养过程,以确定对核心指标可能产生影响的因素。采用单因素试验对pH控制值、溶氧控制值和补料方式等进行考察,通过中试规模(20 L)培养工艺桥接和中试规模(200 L)培养工艺的放大,分析中试规模培养条件及发酵液中伤寒Vi荚膜多糖含量等。结果连续培养了6批次200 L规模发酵液,培养8 h时发酵液中伤寒Vi荚膜多糖含量均≥43.33μg/mL(期望值);培养条件:(1) pH控制值为7.2;(2)溶氧控制值为35%;(3)补料方式为培养初始补加葡萄糖溶液使其质量浓度为3 g/L,培养过程中补加葡萄糖溶液使其质量浓度保持在1～3 g/L。结论通过分析200 L规模培养过程监测数据,成功在中试规模(200 L)完成伤寒沙门菌培养工艺放大。     

Role for dopamine in malonate-induced damage in vivo in striatum and in vitro in mesencephalic cultures

Defects in mitochondrial energy metabolism have been implicated in the pathology of several neurodegenerative disorders. In addition, the reactive metabolites generated from the metabolism and oxidation of the neurotransmitter dopamine (DA) are thought to contribute to the damage to neurons of the basal ganglia. We have previously demonstrated that infusions of the metabolic inhibitor malonate into the striata of mice or rats produce degeneration of DA nerve terminals. In the present studies, we demonstrate that an intrastriatal infusion of malonate induces a substantial increase in DA efflux in awake, behaving mice as measured by in vivo microdialysis. Furthermore, pretreatment of mice with tetrabenazine (TBZ) or the TBZ analogue Ro 4-1284 (Ro-4), compounds that reversibly inhibit the vesicular storage of DA, attenuates the malonate-induced DA efflux as well as the damage to DA nerve terminals. Consistent with these findings, the damage to both DA and GABA neurons in mesencephalic cultures by malonate exposure was attenuated by pretreatment with TBZ or Ro-4. Treatment with these compounds did not affect the formation of free radicals or the inhibition of oxidative phosphorylation resulting from malonate exposure alone. Our data suggest that DA plays an important role in the neurotoxicity produced by malonate. These findings provide direct evidence that inhibition of succinate dehydrogenase causes an increase in extracellular DA levels and indicate that bioenergetic defects may contribute to the pathogenesis of chronic neurodegenerative diseases through a mechanism involving DA.     

Scurvy in capybaras bred in captivity in Argentine

In order to determine if the absence of vitamin C in the diet of capybaras (Hydrochoerus hydrochaeris) causes scurvy, a group of seven young individuals were fed food pellets without ascorbic acid, while another group of eight individuals received the same food with 1 g of ascorbic acid per animal per day. Animals in the first group developed signs of scurvy-like gingivitis, breaking of the incisors and death of one animal. Clinical signs appeared between 25 and 104 days from the beginning of the trial in all individuals. Growth rates of individuals deprived of vitamin C was considerably less than those observed in the control group. Deficiency of ascorbic acid had a severe effect on reproduction of another population of captive capybaras. We found that the decrease in ascorbic acid content in the diet affected pregnancy, especially during the first stages. The results obtained suggest that it is necessary to supply a suitable quantity of vitamin C in the diet of this species in captivity.     

Changes in lactate dehydrogenase activity in chicken tissues in hyperthyreosis in ontogenesis

The lactate dehydrogenase activity in reactions of lactate oxidation and synthesis was studied in subfractions of the chicken brain, heart and liver at the embryonal, early postembryonal and adult stages of development after thyroxine administration. It has been shown that during embryogenesis thyroxine predominantly enhanced the rate of lactate oxidation in the mitochondrial tissues. A marked increase in the lactate synthesis was found in cytoplasm of the adult chicken tissues. Specificity of enzyme activity alterations was detected in the chicken brain during ontogenesis after thyroxine administration.     

SSTR5 ablation in islet results in alterations in glucose homeostasis in mice

Somatostatin (SST) peptide is a potent inhibitor of insulin secretion and its effect is mediated via somatostatin receptor 5 (SSTR5) in the endocrine pancreas. To investigate the consequences of gene ablation of SSTR5 in the mouse pancreas, we have generated a mouse model in which the SSTR5 gene was specifically knocked down in the pancreatic beta cells (betaSSTR5Kd) using the Cre-lox system. Immunohistochemistry analysis showed that SSTR5 gene expression was absent in beta cells at three months of age. At the time of gene ablation, betaSSTR5Kd mice demonstrated glucose intolerance with lack of insulin response and significantly reduced serum insulin levels. Insulin tolerance test demonstrated a significant increase of insulin clearance in vivo at the same age. In vitro studies demonstrated an absence of response to SST-28 stimulation in the betaSSTR5Kd mouse islet, which was associated with a significantly reduced SST expression level in betaSSTR5Kd mice pancreata. In addition, betaSSTR5Kd mice had significantly reduced serum glucose levels and increased serum insulin levels at 12 months of age. Glucose tolerance test at an older age also indicated a persistently higher insulin level in betaSSTR5Kd mice. Further studies of betaSSTR5Kd mice had revealed elevated serum C-peptide levels at both 3 and 12 months of age, suggesting that these mice are capable of producing and releasing insulin to the periphery. These results support the hypothesis that SSTR5 plays a pivotal role in the regulation of insulin secretion in the mouse pancreas.