Contribution of different somatosensory afferent input to subcortical somatosensory evoked potentials in humans

ObjectivesTo investigate the subcortical somatosensory evoked potentials (SEPs) to electrical stimulation of either muscle or cutaneous afferents.MethodsSEPs were recorded in 6 patients suffering from Parkinson’s disease (PD) who underwent electrode implantation in the pedunculopontine (PPTg) nucleus area. We compared SEPs recorded from the scalp and from the intracranial electrode contacts to electrical stimuli applied to: 1) median nerve at the wrist, 2) abductor pollicis brevis motor point, and 3) distal phalanx of the thumb. Also the high-frequency oscillations (HFOs) were analysed.ResultsAfter median nerve and pure cutaneous (distant phalanx of the thumb) stimulation, a P1-N1 complex was recorded by the intracranial lead, while the scalp electrodes recorded the short-latency far-field responses (P14 and N18). On the contrary, motor point stimulation did not evoke any low-frequency component in the PPTg traces, nor the N18 potential on the scalp. HFOs were recorded to stimulation of all modalities by the PPTg electrode contacts.ConclusionsStimulus processing within the cuneate nucleus depends on modality, since only the cutaneous input activates the complex intranuclear network possibly generating the scalp N18 potential.SignificanceOur results shed light on the subcortical processing of the somatosensory input of different modalities.     

Immunogenicity of next-generation HPV vaccines in non-human primates: Measles-vectored HPV vaccine versus Pichia pastoris recombinant protein vaccine

Human papillomavirus (HPV) infection is the most common sexually transmitted disease worldwide. HPVs are oncogenic small double-stranded DNA viruses that are the primary causal agent of cervical cancer and other types of cancers, including in the anus, oropharynx, vagina, vulva, and penis. Prophylactic vaccination against HPV is an attractive strategy for preventing cervical cancer and some other types of cancers. However, there are few safe and effective vaccines against HPV infections. Current first-generation commercial HPV vaccines are expensive to produce and deliver.The goal of this study was to develop an alternate potent HPV recombinant L1-based vaccines by producing HPV virus-like particles into a vaccine that is currently used worldwide. Live attenuated measles virus (MV) vaccines have a well-established safety and efficacy record, and recombinant MV (rMV) produced by reverse genetics may be useful for generating candidate HPV vaccines to meet the needs of the developing world.We studied in non-human primate rMV-vectored HPV vaccine in parallel with a classical alum adjuvant recombinant HPV16L1 and 18L1 protein vaccine produced in Pichia pastoris. A combined prime-boost approach using both vaccines was evaluated, as well as immune interference due to pre-existing immunity against the MV.The humoral immune response induced by the MV, Pichia-expressed vaccine, and their combination as priming and boosting approaches was found to elicit HPV16L1 and 18L1 specific total IgG and neutralizing antibody titres. Pre-existing antibodies against measles did not prevent the immune response against HPV16L1 and 18L1.     

Carboxylesterase catalyzed 18O-labeling of carboxylic acid and its potential application in LC-MS/MS based quantification of drug metabolites

LC-MS quantification of drug metabolites is sometimes impeded by the availability of internal standards that often requires customized synthesis and/or extensive purification. Although isotopically labeled internal standards are considered ideal for LC-MS/MS based quantification, de novo synthesis using costly isotope-enriched starting materials makes it impractical for early stage of drug discovery. Therefore, quick access to these isotope-enriched compounds without chemical derivatization and purification will greatly facilitate LC-MS/MS based quantification. Herein, we report a novel ¹⁸O-labeling technique using metabolizing enzyme carboxylesterase (CES) and its potential application in metabolites quantification study. Substrates of CES typically undergo a two-step oxygen exchange with H₂¹⁸O in the presence of the enzyme, generating singly- and doubly-¹⁸O-labeled carboxylic acids; however, unexpected hydrolytic behavior was observed for three of the test compounds – indomethacin, piperacillin and clopidogrel. These unusual observations led to the discovery of several novel hydrolytic mechanisms. Finally, when used as internal standard for LC-MS/MS based quantification, these in situ labeled compounds generated accurate quantitation comparable to the conventional standard curve method. The preliminary results suggest that this method has potential to eliminate laborious chemical synthesis of isotope-labeled internal standards for carboxylic acid-containing compounds, and can be developed to facilitate quantitative analysis in early-stage drug discovery.     

白细胞介素-8在哺乳动物生殖过程中的作用

白细胞介素-8(IL-8)作为中性粒细胞趋化因子和促血管生成因子,受到人们的重视。研究表明,IL-8促进卵细胞的发育、成熟,诱发排卵;在输卵管和子宫内膜的表达随月经周期而变化;参与胚泡着床和胚胎发育。本文综述IL-8在哺乳动物生殖过程中的重要作用。     

Antibodies to interleukin-1 inhibit cytokine-induced proliferation of neonatal rat Schwann cells in vitro

Unfractionated cytokines have been shown to induce in vitro proliferation of neonatal rat Schwann cells but the nature of the mitogen(s) is not known. A mixture of rabbit antibodies specific for recombinant interleukin-1α (IL-1α) and interleukin-1β (IL-1β) inhibited Schwann cell proliferation induced by unfractionated human cytokines whereas antibodies to interleukin-2 (IL-2) and control IgG did not. However, purified human IL-1 and recombinant human IL-1α or β did not induce Schwann cell proliferation on their own.     

白细胞介素-18基因修饰的胎肝细胞经脾移植对小鼠免疫功能的影响

目的：观察表达mIL-18的重组腺病毒基因修饰的胎肝细胞（AdmIL-18/BNL.CL2)经脾移植对正常小鼠免疫功能的影响。方法：实验组小鼠经脾移植AdmIL-18/BNL.CL2，同时设LacZ病毒对照组（Ad-LacZ/BNL.CL2),BNL.CL2细胞对照组及空白对照组。2周后处死，留取血清，制备腹腔巨噬细胞、脾淋巴细胞、肝组织匀浆液，提取肝组织总RNA。采用ELISA法检测各组小鼠血清、腹腔Mφ和脾细胞培养上清、肝匀浆中细胞因子的含量；采用半定量RT－PCR法，检测肝组织细胞因子mRNA相对表达量；以LDH释放法测定腹腔Mφ杀伤活性和脾NK细胞活性，用MTT还原比色法测定脾淋巴细胞的增殖活性。结果：实验组小鼠血清、细胞培养上清及肝匀浆中，IL－18、IL－2、IFN－γ、TNF-α稔均高于其它对照组，而IL－4、IL－10水平则低于对照组；半定量RT－PCR结果与ELISA检测结果一致；同时，实验组腹腔Mφ的杀伤活性和脾NK细胞活性，及脾淋巴细胞增殖活性也明显高于对照组。结论：AdmIL-18能有效转染至胎肝细胞并稳定表达mIL-18;AdmIL-18基因修饰的胎肝细胞经脾移植后，可显著提高肝脏、脾脏免疫细胞活性，活化腹腔Mφ，促进Th1类细胞因子表达，抑制Th2类细胞因子的分泌。     

白介素-6、血管内皮生长因子、D-二聚体对CSDH的影响

目的探讨血肿局部炎症、假膜新血管生成、局部纤溶状况及其在CSDH发生、发展中的作用。进而探讨CSDH的发病机制，并为CSDH的治疗及预防复发提供理论依据。方法以78例CSDH患者作为病例组，20例健康人作为正常对照组。采用ELISA法测定患者血清及血肿液中VEGF及IL-6的含量。比较患者末梢静脉血及血肿液中四种因子的含量变化并与正常对照组比较。结果病例组血肿液FDP、d-dimer检测均为阳性，血液为阴性；正常对照组血液FDP、d-dimer检测均为阴性；病例组血清VEGF含量与正常对照组比较差异无统计学意义。血肿液中VEGF浓度高于血清中。病例组血清IL-6浓度与正常对照组差异无统计学意义，血肿液中IL-6浓度高于血清中。CSDH患者血肿液VEGF、IL-6水平没有相关性。结论CSDH患者血肿液局部纤溶亢进，局部VEGF分泌旺盛，新血管生成活跃，局部炎症活跃，可导致CSDH不断扩大而参与CSDH发病机制。抗炎治疗、抑制VEGF的生理作用、有选择的对病人施行促凝治疗，可成为部分CSDH病人保守治疗及预防复发的有效手段。     

白细胞介素-15对骨髓增生异常综合征骨髓造血干/祖细胞增殖的影响

目的：观察白细胞介素(IL-15)对体外培养的骨髓增生异常综合征(MDS)患者CD34^ 细胞增殖作用。方法：应用单克隆抗体免疫磁珠分离系统提取MDS患者CD34^ 细胞，以加IL-15组为实验组，不加IL-15组为对照组，进行液体和甲基纤维素半固体集落培养，计算培养后细胞数和CFU—E、BFU—E、CFU—GM、CFU—GEMM等集落数，并用MTT比色法检测IL-15对MDS患者CD34^ 细胞增殖的抑制作用，流式细胞术检测上述培养细胞周期的变异情况。结果：11例MDS对象平均CD34^ 细胞比例、回收率、纯度和富集倍数均达要求，MTT比色法检测IL-15对CD34^ 细胞的增殖作用呈最佳浓度效应，最佳浓度为20μg／L，细胞增殖抑制最低峰值时间为8d。用0μg／L IL-15(对照组)和20μg／L IL-15(实验组)作用MDS CD34^ 细胞，计数显示培养细胞最大增殖倍数和集落形成比率实验组均较对照组明显增加，IL-15作用后各细胞周期G1、S、G2期比例有明显改变，与对照组比较，差异有统计学意义。结论：IL-15对MDS CD34^ 细胞有促增殖效应，与其它造血生长因子具有协同作用，对MDS治疗可能有一定的应用前景。     

18氟-氟化脱氧葡萄糖在下咽部肿瘤诊断中的作用

目的：研究^18氟—氟化脱氧葡萄糖(^18F-FDG)在下咽部肿瘤诊断中的作用。方法：20例下咽部肿瘤患者均接受^18F-FDG检查及CT、全组内镜(食管、咽喉、气管镜)检查。结果：20例下咽部肿瘤患者^18F-FDG检查结果显示：2例阴性；18例肿瘤原发部位有同位素浓集，其中5例伴异位同位素浓集。对此5例患者进一步临床、病理检查证实：1例食管部占位，2例肺部病变，2例为良性改变。^18F-FDG检查结果显示的病变范围与CT、内镜检查相符。结论：^18F-FDG检查可以提高下咽部肿瘤、尤其是隐匿的并发肿瘤诊断的准确性，明确病变范围，为临床治疗提供依据；同时又是一个简单、易行的下咽部肿瘤的随访检查手段。