Comparison of Otoacoustic Emissions Within Gecko Subfamilies: Morphological Implications for Auditory Function in Lizards

Otoacoustic emissions (OAEs) are sounds emitted by the ear and provide a non-invasive probe into mechanisms underlying peripheral auditory transduction. This study focuses upon a comparison of emission properties in two phylogenetically similar pairs of gecko: Gekko gecko and Hemidactylus turcicus and Eublepharis macularius and Coleonyx variegatus. Each pair consists of two closely related species within the same subfamily, with quantitatively known morphological properties at the level of the auditory sensory organ (basilar papilla) in the inner ear. Essentially, the comparison boils down to an issue of size: how does overall body size, as well as the inner-ear dimensions (e.g., papilla length and number of hair cells), affect peripheral auditory function as inferred from OAEs? Estimates of frequency selectivity derived from stimulus-frequency emissions (emissions evoked by a single low-level tone) indicate that tuning is broader in the species with fewer hair cells/shorter papilla. Furthermore, emissions extend outwards to higher frequencies (for similar body temperatures) in the species with the smaller body size/narrower interaural spacing. This observation suggests the smaller species have relatively improved high-frequency sensitivity, possibly related to vocalizations and/or aiding azimuthal sound localization. For one species (Eublepharis), emissions were also examined in both juveniles and adults. Qualitatively similar emission properties in both suggests that inner-ear function is adult like soon after hatching and that external body size (e.g., middle-ear dimensions and interaural spacing) has a relatively small impact upon emission properties within a species.     

蛤蚧的辨析

蛤蚧是传统名贵药材,可助阳益血,由于其进补疗效好且药源较少,市场上出现大量混淆品及伪品。为给蛤蚧正品溯源,将其特征鉴别、显微、理化鉴别等加以总结,并列举了与其混淆的多种伪品,并对其毒性、药理进行了研究概述,在蛤蚧的真伪辨识和使用方面加以探讨,为临床进一步研究和应用打下良好的基础。     

No evidence for calcium electrogenic exchanger in frog semicircular canal hair cells

We investigated the possibility that, in hair cells mechanically isolated from frog semicircular canals, Ca2+ extrusion occurs via a Na+ : Ca2+ (cardiac type) or a Na+ : Ca2+,K+ (retinal type) exchanger. Cells concurrently imaged during whole-cell patch-clamp recordings using the Ca2+ sensitive fluorescent dye Oregon Green 488 BAPTA-1 (100 micro m) showed no voltage dependence of Ca2+ clearance dynamics following a Ca2+ load through voltage-gated Ca2+ channels. Reverse exchange was probed in hair cells dialyzed with a Ca2+- and K+-free solution, containing a Na+ concentration that saturates the exchanger, after zeroing the contribution to the whole-cell current from Ca2+ and K+ conductances. In these conditions, no reverse exchange current was detected upon switching from a Ca2+-free external solution to a solution containing concentrations of Ca2+ alone, or Ca2+ + K+ that saturated the exchanger. By contrast, the same experimental protocol elicited peak exchange currents exceeding 100 pA in gecko rod photoreceptors, used as positive controls. In both cell types, we also probed the forward mode of the exchanger by rapidly increasing the intracellular Ca2+ concentration using flash photolysis of two novel caged Ca2+ complexes, calcium 2,2'-([1-(2-nitrophenyl)ethane-1,2-diyl]bis(oxy))bis(acetate) and calcium 2,2'-([1-(4,5-dimethoxy-2-nitrophenyl)ethane-1,2-diyl]bis(oxy)) bis(acetate), in the presence of internal K+ and external Na+. No currents were evoked by UV-triggered Ca2+ jumps in hair cells, whereas exchanger conformational currents up to 400 pA, followed by saturating forward exchange currents up to 40 pA, were recorded in rod photoreceptors subjected to the same experimental conditions. We conclude that no functional electrogenic exchanger is present in this hair cell population, which leaves the abundant plasma membrane Ca2+-ATPases as the primary contributors to Ca2+ extrusion.     

大壁虎附肢肌的定量研究

目的为研究大壁虎运动及其生物控制提供附肢肌的定量形态资料。方法以醛类固定剂按规定姿势对动物进行固定处理约15d,再行肌肉的分离解剖,并对肌的起止、毗邻、分布进行观测。结果相对肌重(肌重/体重×100%)最大为耻坐胫肌(1.094%),小指固有伸肌最小(0.004%)。相对于头体长的最大肌长、肌宽、肌厚(肌肉尺寸/头体长×100%)分别是3.678(胸大肌)、1.322(耻坐胫肌)、0.423(尾股肌);最小值则分别是0.385(深指短屈肌)、0.056(背骨间肌)、0.036(背骨间肌)。同名肌的左、右侧没有显著差异(P>0.05)。前、后附肢肌总重量比为1∶1.4027(左)、1∶1.3282(右)。结论测量数据可为肌相关性能的定量分析及整体环节受力分析提供依据。     

温度及冻融对壁虎抗H22肝癌作用的影响

目的：研究不同炮制温度及冻融对壁虎抗肝癌效果的影响，以明确较合适的壁虎炮制方法，指导临床应用。方法：MTT法检测37℃、75℃、100℃炮制的壁虎高、低剂量提取液对H22肝癌细胞体外杀伤作用。昆明小鼠H22移植瘤模型观察不同温度（37℃、75℃、100℃）炮制的壁虎高、低剂量组及非冻融壁虎组体内抑瘤活性及荷瘤小鼠胸腺、脾脏指数变化。结果：MTT法检测显示，壁虎不同温度高、低剂量组均可抑制H22细胞的增殖（P〈0．05），高剂量组与西药抑制率差异无显著性意义（P〉0．05）。体内实验显示75℃高剂量组抑制率45．8％与模型组比较差异有显著性意义（P〈0．05）。37℃、100℃各组与模型组无统计学差异（P〉0．05）。非冻融焙壁虎与干壁虎冻干粉抑瘤率分别为49．8％和51．1％，差异无显著性意义（P〉0．05）。不同温度壁虎组，非冻融焙壁虎组，干壁虎冻干粉组与模型组小鼠的胸腺重、胸腺指数、脾脏重、脾脏指数相比均没有明显差异。而5-Fu组胸腺重、胸腺指数、脾脏重、脾脏指数较模型组和各壁虎组均明显降低（P〈0．05）。结论：体内外实验均显示75℃恒温炮制能保持壁虎抗肿瘤活性成分，是有效的炮制温度。冻融并不是壁虎保持抗肝癌活性的必要条件。     

中药蛤蚧对非酒精性脂肪肝内质网应激的影响分析

目的：探析中药蛤蚧对非酒精性脂肪肝内质网应激的影响。方法以60只健康雄性C57BL/6小鼠进行研究,高脂饲料喂养的小鼠纳入模型组(n=30),普通饲料标准喂养的小鼠纳入正常对照组(n=30)。模型组中应用中药蛤蚧的小鼠为A组,生理盐水为B组;正常对照组中应用中药蛤蚧的小鼠为C组,生理盐水组为D组。比较建模前后、喂药前后小鼠肝脏内质网应激,具体用丙二醛( MDA)、还原性谷胱甘肽( GSH)及氧化型谷胱甘肽( GSSG)等指标。结果两组建模前MDA、GSH及GSSG的差异无统计学意义(P>0．05),建模后正常对照组各项指标无明显变化(P>0．05);建模后模型组MDA、GSSG升高、GSH降低(P<0．05)。 B、C、D组喂药前后差异无统计学意义(P>0．05);A组(中药蛤蚧)喂药后MDA与GSSG均明显降低、GSH升高(P<0．05)。结论中药蛤蚧具有调节脂质代谢、保肝、抗炎、抗氧化、增强免疫、提高细胞对内质网应激忍耐性等作用,在非酒精性脂肪肝中的应用可通过发挥降脂作用启动肝细胞内质网胁迫机制,最终保护肝脏组织。     

壁虎醇提物体外诱导人前列腺癌PC-3细胞凋亡及机制研究

目的:研究壁虎醇提物(GAE)体外诱导激素非依赖性前列腺癌PC-3细胞凋亡作用及其可能机制,为激素非依赖性前列腺癌的治疗提供理论依据。方法:以前列腺癌PC-3细胞为研究对象,MTT法检测3.5,4.0,4.5,5.0,5.5 g·L~(-1)GAE作用细胞24,48,72 h后对激素非依赖性前列腺癌PC-3细胞增殖抑制作用;3.5,4.0,5.0 g·L~(-1)的GAE作用48 h后,另设空白组,Hoeehst33342荧光染色法,Annexin V-FITC/PI双染流式细胞仪检测细胞凋亡,SP免疫组化法检测细胞内半胱氨酸蛋白酶3(Caspase 3)和Fas的表达情况并做统计学处理。结果:3.5,4.0,4.5,5.0,5.5 g·L~(-1)GAE作用细胞24,48,72 h后能显著抑制PC-3细胞的生长且呈剂量和时间依赖性;与空白组比较,3.5,4.0,5.0 g·L~(-1)的GAE作用48 h后Hoeehst33342荧光染色发现部分PC-3细胞发生典型的凋亡形态学改变;Annexin V-FITC/PI双染流式细胞仪检测显示3.5,4.0,5.0 g·L~(-1)的GAE作用48 h后,早期凋亡细胞分别占6.51%,12.48%和22.81%,且免疫组化显示细胞内蛋白Caspase-3和Fas的表达均上调且呈浓度依赖性(P0.05)。结论:GAE能够诱导激素非依赖性前列腺癌PC-3细胞凋亡,其作用机制可能与死亡受体介导的信号通路有关。     

基于COI 条形码序列的蛤蚧及其混伪品的DNA 分子鉴定

目的：利用COI 序列对蛤蚧药材及其常见混伪品进行DNA 条形码鉴定,为蛤蚧药材鉴定提供新的方法。方法：以COI 作为条形码序列,对蛤蚧实验样品进行DNA 提取,PCR 扩增和双向测序,用MEGA6.0 对所有11 个物种的103 份样品进行序列比对和邻接（NJ）树构建。结果：所有实验样品均可以获得COI 序列,蛤蚧COI 序列种内平均K2P 距离为0.005,种内最大K2P 距离为0.013,基于COI 序列构建的NJ 树中蛤蚧单独聚在一支,与其混伪品可以相互区分。结论：运用COI 条形码序列能够准确鉴定蛤蚧及其混伪品,为保障蛤蚧药材临床用药安全和市场监管提供新的方法。     

Organization of the auditory brainstem in a lizard, Gekko gecko. I. Auditory nerve, cochlear nuclei, and superior olivary nuclei

We used tract tracing to reveal the connections of the auditory brainstem in the Tokay gecko (Gekko gecko). The auditory nerve has two divisions, a rostroventrally directed projection of mid- to high best-frequency fibers to the nucleus angularis (NA) and a more dorsal and caudal projection of low to middle best-frequency fibers that bifurcate to project to both the NA and the nucleus magnocellularis (NM). The projection to NM formed large somatic terminals and bouton terminals. NM projected bilaterally to the second-order nucleus laminaris (NL), such that the ipsilateral projection innervated the dorsal NL neuropil, whereas the contralateral projection crossed the midline and innervated the ventral dendrites of NL neurons. Neurons in NL were generally bitufted, with dorsoventrally oriented dendrites. NL projected to the contralateral torus semicircularis and to the contralateral ventral superior olive (SOv). NA projected to ipsilateral dorsal superior olive (SOd), sent a major projection to the contralateral SOv, and projected to torus semicircularis. The SOd projected to the contralateral SOv, which projected back to the ipsilateral NM, NL, and NA. These results suggest homologous patterns of auditory connections in lizards and archosaurs but also different processing of low- and high-frequency information in the brainstem.