Presence of haemocyte-like cells in coccinellid reflex blood

Abstract.  Contrary to current assumptions, the reflex blood of two-spot ladybirds, Adalia bipunctata , and seven-spot ladybirds, Coccinella septempunctata , contains haemocyte-like cells. Furthermore, DNA can be extracted and amplified from coccinellid reflex blood, confirming the presence of haemocyte-like cells and demonstrating a nondestructive method of DNA extraction.     

A computerized mechanical cell stimulator for tissue culture: Effects on skeletal muscle organogenesis

Summary A tissue culture system has been developed which can mechanically stimulate cells growing on a highly elastic plastic substratum in a 24-well cell growth chamber. The collagen-coated substratum to which the cells attach and grow in the Mechanical Cell Stimulator (Model I) can be repetitively stretched and relaxed by stepper motor with linear accuracy of 30 μm. The activity controlling unit is an Apple IIe computer interfaced with the cell growth chamber via optical data links and is capable of simulating many of the mechanical activity patterns that cells are subjected to in vivo. Primary avian skeletal myoblasts proliferate and fuse into multinucleated myotubes in this set-up in a manner similar to normal tissue culture dishes. Under static culture conditions, the muscle cells differentiate into networks of myotubes which show little orientation. Growing the proliferating muscle cells on a unidirectional stretching substratum causes the developing myotubes to orient parallel to the direction of movement. In contrast, growing the cells on a substratum undergoing continuous stretch-relaxation cycling orients the developing myotubes perpendicular to the direction of movement. Neither type of mechanical activity significantly affects the rate of cell proliferation of the rate of myoblast fusion into myotubes. These results indicate that during in vivo skeletal muscle organogenesis, when substantial mechanical stresses are placed on skeletal muscle cells by both continuous bone elongation and by spontaneous contractions, only bone elongation plays a significant role in proper fiber orientation for subsequent functional work. Supported by grants NS16753, AR36266, and RR05818 from the National Institutes of Health, Bethesda, MD.     

电刺激大鼠外侧缰核对延髓甩尾相关细胞的活动和甩尾反射的影响

在浅麻醉大鼠上,在延髓腹内侧结构内观察到三种具有不同放电类型的细胞,即乃尾前放电骤停的撤反应细胞,甩尾前放电骤增的给反应细胞和甩尾无关的中性细胞。电刺激外侧缰核可抑制撤反应细胞的自发放电,加强给反应细胞自发放电,从而易化两类细胞的甩尾相关反应,同时易化伤害刺激引起的甩尾反射。实验结果说明,外侧缰核对节段性防御反射有易化作用,这种易化作用可能是通过延髓内撤反应和反应细胞的协同活动而实现的。     

Role of water receptor in the frog

To elucidate the role of the water receptor in the frog (Rana catesbeiana), reflex activities elicited by its excitation were studied. Application of tap water to the oral mucosa depressed the rhythmical movement of gorge (buccal) respiration, accompanied by an elevation of the inner pressure of the oral cavity (buccal pressure). Tonic reflex discharges were elicited in the nerves innervating the submental and submaxillary muscles, which close the nostrils, the pterygoid and the profound portion of the major masseter muscles, which produce a strong bite, and the geniohyoid and hyoglossus muscles, which elevate buccal pressure. These muscles, except for the pterygoid, also participate in the rhythmical movement of gorge respiration as expiratory muscles. Rhythmical movements in the minor masseter and sternohyoid muscles, which act as inspiratory muscles in gorge respiration, were depressed by the water stimulation of the oral mucosa. These findings indicate that the water receptor plays a role in the interruption of gorge respiratory movements, accompanied by an elevation of buccal pressure.     

Infrared spectra of carbon monoxide bound to mitochondria from diverse species and tissues reveal structurally similar cytochrome c oxidase dioxygen reaction sites

Infrared bands for CO bound to mitochondria from bovine and porcine hearts, bovine brain, rat kidney, and blowfly flight muscle and to intact blowfly flight muscle have been measured in the carbon-oxygen stretch region. Each spectrum contains a narrow band near 1963 cm-1 similar to the major band found earlier for the carbonyl cytochrome c oxidase purified from bovine heart. A second band near 1959 cm-1 ascribed to a less stable conformer of the purified oxidase carbonyl is also detected in mitochondria. These spectra support very similar CO (and O2) binding sites among all the oxidases examined whether the enzyme is purified or is still within mitochondria or intact tissue and therefore suggest that the reduced heme A ligand binding site has been highly conserved during evolution.     

不饱和脂肪酸在低渗牵张加强豚鼠胃窦平滑肌细胞毒蕈碱电流中的作用

利用全细胞膜片钳技术在急性分离的胃窦平滑肌细胞上记录离子电流的方法 ,探讨外源性不饱和脂肪酸是否参与低渗牵张加强毒蕈碱电流的过程。在豚鼠胃窦平滑肌细胞上膜电位被钳制在 - 2 0 0mV等渗状态时 ,5 0 μmol/L卡巴胆碱 (carbachol,CCh)引起的毒蕈碱电流 (ICCh)作为对照 ,发现低渗牵张可以使ICCh明显增加到对照的 2 2 6 0±2 1 0 %。当用含 5 μmol花生四烯酸 (arachidacid ,AA)、亚麻酸 (linoleicacid ,LA)或亚油酸 (oleicacid,OA)细胞外液灌流时 ,ICCh分别被抑制在对照的 3 8± 0 6%、3 5 2± 0 8%和 66 6± 0 6%。在这种情况下 ,低渗牵张刺激可以使ICCh分别增加到 10 6 0± 2 5 %、173 2± 6 8%和 2 2 2 1± 11 0 %。 5 μmol/LAA抑制低渗牵张增加的毒蕈碱电流 5 1 2± 3 8% ,而在等渗状态下抑制ICCh为 96 2± 1 6%。上述结果提示 ,不饱和脂肪酸中双键数目越多 ,抑制效应越强 ;但不饱和脂肪酸不参与低渗刺激加强毒蕈碱电流的过程。     

噪声对豚鼠内耳组织能量代谢的影响——噪声致聋机理

豚鼠暴露于125dB SPL噪声下1小时后即刻、1天内耳组织中葡萄糖(46.0±18.3μg/mg蛋白,102.2±56.3μg/mg蛋白)及丙酮酸量(30.6±8.4μg/g蛋白,47.1±15.7μg/g蛋白)均显著地高于对照组(葡萄糖26.4±8.9μg/mg蛋白,丙酮酸23.7±8.9μg/g蛋白),p<0.05。与此同时豚鼠听功能耳廓反射阈衰减dB值(30.0±12.2dB,44.8±2.5dB)显著地低于暴露前水平(49.4±2.9dB,46.2±1.9dB),P相似文献   

下丘脑局部损毁对大鼠双侧催产素神经元爆发放电的影响

为探究授乳大鼠双侧下丘脑巨细胞催产素神经元同步化射乳反射爆发放电的中枢所中,我们采用双微电极细胞外记录技术,观察了选择性脑切割损毁后的大鼠双侧视上核内催们素神经元在仔鼠吸吮刺激下射乳反射爆发放电。结果显示：在腹侧这画以上横向民单侧中脑中部,不同能阻断双侧催产素神经元的同步化爆发放 单侧下丘脑中间内侧部横切则可阻断这种经爆发放电。这些结果表明;中脑中部至一丘脑中部这一脑区在双侧视上核内催产素神经元的     

卧床前后压力感受性反射机能变化的研究

许多数据表明长期失重以后立位耐力降低可能与压力感受性反射功能的改变有关。本文比较了两组被试者15天低动力卧床前后的立位耐力。以血压调节模型为基础分析了两种不同方式卧床前后单纯立位和下身负压加立位时压力感受性反射功能的改变,并用颈部加压及下身负压对中枢调节功能改变进行了观察。结果表明严格的头低位卧床后,立位耐力下降及压力感受性反射功能改变明显大于半日平卧半日倚坐者。而压力感受性反射功能的改变,特别是中枢神经系统调节功能的紊乱,是卧床后立位耐力降低的主要原因。从这种考虑为基础,作者提出了改变失重或模拟失重状态下的血液分布,调整对压力感受器的刺激,可能是预防心血管失调的有效方法。