Advance in research on recycling antibody / 生物工程学报

Monoclonal antibodies have become the main type of antibody drug because of their high specificity and strong affinity to antigen. However, with the intensive study of the natural monoclonal antibody, many defects have faced, such as the limit times of binding to antigen, the unanticipated antibody clearance and antigen accumulation. Therefore, studies are no longer limited to the natural antibody screening, but rather to improve the efficiency of antibody drugs by engineering. In recent years, the bottlenecks in the development of conventional antibody have been solved effectively since the discovery of a novel recycling antibody. Recycling antibody binds to an antigen in plasma and dissociates from the antigen in endosome, thus maximizing the use of antibody and reducing antigen-mediated antibody clearance and antibody-mediated antigen accumulation. In addition, recycling antibodies can enhance the affinity with Fc receptors through further Fc modification. This paper reviews the research progress of circulating antibodies, including its characteristics, transformation methods and prospects.

Simultaneous Determination of Eight Saponins in Gynostemma pentaphyllum(Thunb.) Makino by HPLC / 广州中医药大学学报

Objective To establish a high performance liquid chromatography(HPLC) method for the simultaneous determination of eight components in Gynostemma pentaphyllum(Thunb.) Makino (ginsenosides Rb1, Rb3, Rd, Re, F2, and gypenosides A, XLIX and XVII). Methods HPLC was performed on Agilent Eclipse XDB-C18(4.6 mm × 250 mm, 5 μm) chromatographic column with 0.3％ formic acid solution (A)- acetonitrile (B) as the mobile phase by gradient elution, flow rate was 1.5 mL·min-1, detection wavelength was 203 nm, and column temperature was set at 50 ℃. Results There was a good linear relationship between peak area and concentration of eight components (r ≥ 0.999) , the recovery was in the range of 97％ to 100％. Conclusion The established method is simple, rapid, accurate, reliable, and reproducible, and can be used for the quality control of Gynostemma pentaphyllum(Thunb.) Makino.

Structure of off-pump coronary artery bypass graft model in dogs / 局解手术学杂志

Objective To study the feasibility of model building methods by analyzing the advantages and disadvantages between the two different methods to build off-pump coronary artery bypass graft animal model. Methods Twenty dogs were randomly divided into two groups:brachiocephalic artery group and descending aorta group. Small-caliber heterogeneous vascular vessels were used as bridge vessels. The incision was in the fourth intercostal space of the left chest. Vascular anastomosis was firstly done between the brachiocephalic artery and bridge vessels,or between descending aorta and bridge vessels,prior to coronary vascular and bridge vessels anastomosis. Results The dogs of two groups were not dead during operation. Brachiocephalic artery group and the descending aorta group:aortic vascular anastomosis times were (33.9 ±4.8) min and (29.6 ±3.5) min respectively (P0. 05). The surgical blood losses of the two groups were (77. 5 ± 16. 2) mL and (66. 5 ± 12. 3) mL re-spectively (P>0. 05). After side clamping descending aorta,femoral blood pressure significantly decreased in descending aorta group,and the two dogs had melena after operation. Conclusion Off-pump coronary artery bypass graft models were both constructed successfully by the two ways. Descending aorta group of femoral artery blood pressure violently fluctuated and had abdominal organs’ ischemia reperfusion in-jury. Though brachiocephalic artery group anastomosis group spent a little longer time,they had stable artery blood pressure during operation. As a result,the way of constructing animal model of brachiocephalic artery group is safer.

Effect of NH4(+) -N/NO3(-)-N ratio in applied supplementary fertilizer on nitrogen metabolism and main chemical composition of Pinellia ternata / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of nitrogen forms on nitrogen metabolism and main chemical composition of Pinellia ternate.</p><p><b>METHOD</b>Through the soilless cultivation experiment and based at the same nitrogen level and different NH4(+) -N/NO3(-) -N ratios, nitrate reductase (NR) activity, glutamine synthetase (GS) activity, the content of nitrate nitrogen and ammonium nitrogen in different parts of P. ternate were determined. The contents of total alkaloid, free total organic acids and guanosine in the tuber were determined. The yield of bulbil and tuber was calculated.</p><p><b>RESULT</b>The test results showed that, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of nitrate reductase decreased, the content of nitrate nitrogen in the leaves, petioles and tuber increasing initially, then decreased, and the content of nitrate nitrogen in the root decreased. Meanwhile, with the NH4(+) -N/NO3(-) -N ratio increasing, the activity of glutamine synthetase in the leaves, petioles and root increased, the activity of glutamine synthetase in the tuber increasing initially, then decreased. The contents of ammonium nitrogen in the leaves, tuber and root increased initially, then decreased, and the contents of ammonium nitrogen in the petioles increased with the NH4(+)(-N/NO3(-)-N ratio increasing. The yield of bulbil and tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 75: 25. The content of total alkaloid and guanosine in the tuber were the highest at the NH4(+)-N/NO3(-) -N ratio of 0: 100, and the contents were 0.245% and 0.0197% respectively. With the NH4(+)-N/NO3(-) -N ratio of 50: 50, the content of free total organic acids was the highest, it reached 0.7%, however, the content of free total organic acids was the lowest at the NH4(+) -N/NO3(-) -N ratio of 0: 100.</p><p><b>CONCLUSION</b>Nitrogen fertilization significant influences the nitrogen metabolism, the yield and main chemical composition of P. ternate.</p>

Effect of exogenous Ca2+ on protective infection of Pinellia ternata and accumulation of major components under high temperature stress / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effect of exogenous Ca2+ on protective infection of Pinellia ternata and accumulation of major components under high temperature stress.</p><p><b>METHOD</b>The soilless cultivation experiment was applied, stress resistance index of P. ternata leaves, statistics the rate of lodge P. ternata,the content of oxalate in different places in the plant, the content of total alkaloids, total organic acids and glucosine in P. ternata tubers were measured based on different concentrations of exogenous Ca2+.</p><p><b>RESULT</b>The test results showed that, at lower concentrations of Ca2+ treatments, the rate of lodge P. ternata was higher than that of the others. With Ca2+ concentration increasing, activities of SOD and POD initially increased and then decreased, however, proline level tended to be down then up. Soluble oxalic acid content was lower than the content of unhandled treatment in P. ternata leaves and tubers; with Ca2+ concentration increasing, soluble oxalic acidl content and yield showed a tendency of decrease after increase in the leaves and tubers. Compared with other treatments, spraying 400 mg x L(-1) Ca2+ significantly enhanced the accumulation of total alkaloid and guanosine in P. ternata tubers. At Lower concentrations of Ca2+, the content of total free organic acid was higher in the tuber.</p><p><b>CONCLUSION</b>With the treatment of Ca2+ the capacity of heat resistance was improved in P. ternata plants, the rate of lodge P. ternata was postponed, growing period was extended and corresponding production has increased by spraying exogenous Ca2+.</p>

Morphological changes of cholinergic nerve fibers in the urinary bladder after establishment of artificial somatic-autonomic reflex arc in rats / 神经科学通报·英文版

<p><b>OBJECTIVE</b>To establish an artificial somatic-autonomic reflex arc in rats and observe the following distributive changes of neural fibers in the bladder.</p><p><b>METHODS</b>Adult Sprague-Dawley rats were randomly divided into three groups: control group, spinal cord injury (SCI) group, and reinnervation group. DiI retrograde tracing was used to verify establishment of the model and to investigate the transport function of the regenerated efferent axons in the new reflex arc. Choline acetyltransferase (ChAT) in the DiI-labeled neurons was detected by immunohistochemistry. Distribution of neural fibers in the bladder was observed by acetylcholine esterase staining.</p><p><b>RESULTS</b>DiI-labeled neurons distributed mainly in the left ventral horn from L3 to L5, and some of them were also ChAT-positive. The neural fibers in the bladder detrusor reduced remarkably in the SCI group compared with the control (P < 0.05). After establishment of the somatic-autonomic reflex arc in the reinnervation group, the number of ipsilateral fibers in the bladder increased markedly compared with the SCI group (P < 0.05), though still much less than that in the control (P < 0.05).</p><p><b>CONCLUSION</b>The efferent branches of the somatic nerves may grow and replace the parasympathetic preganglionic axons through axonal regeneration. Acetylcholine is still the major neurotransmitter of the new reflex arc. The controllability of detrusor may be promoted when it is reinnervated by the pelvic ganglia efferent somatic motor fibers from the postganglionic axons.</p>

Changes of elastic fibers in middle cerebral artery of different aging rats / 中国组织工程研究

BACKGROUND: Changes of elastic fibers in middle cerebral artery(MCA)is close related withthe aged cerebrovascular disease.OBJECTIVE: To observe the changes of elastic fibers of MCA in different aging rats.DESIGN: A descriptive and controlled study based on experimental animals.SETTING: Department of anatomy and central laboratory in a university.MATERIALS: Totally 36 healthy Wistar rats with either gender, weighing 200 - 280 g, were selected from the Animal Institute of the third medical military university of Chongqing[certification SCXX (army) 2002-007].INTERVENTIONS: Changes of elastic fibers of MCA of different aging rats were observed with light microscope, transmission electron microscope and image analysis system. MAIN OUTCOME MEASURES: ①) Major outcome: changes of elastic lamella in MCA of different aging rats; ②) Secondary outcome: ultramicrostructural changes of internal lamella under the transmission electron microscope. RESULTS: With the increase of age, the folded extent and quantity of internal elastic lamella were decreased, and the content of elastic fibers were also decreased significantly( P ＜ 0.01 ). However, the ratio of collagen fibers to elastic fibers was increased significantly( P ＜ 0.01 ) . In the aging group above 24 months, the internal elastic lamina thinned, delaminated and disrupted, and the lipid deposited in it. Endothelial cells and smooth muscle cells passed through the internal elastic lamina. CONCLUSION: Changes of elastic fibers may be related with the increased susceptibility to the cerebrovascular disease in aged people.

Recent advances in artrial elastin / 中国病理生理杂志

A Review The elastin has been investigated since the 1950 s, and it has been found that elastin relates to the vascular diseases in recent years. In this review, the elastin gene structure, distribution and its role in the pathogenesis of vascular diseases and aging are summarized.

Retrograde tracing study on neurons labeled by injecting rear-thigh muscles with DiI in mice / 第三军医大学学报

Objective To explore the fluorescent distribution, and the relation between fluorescent intensity and time after injecting rear-thigh muscles with DiI. Methods Sixty-five new born mice were equally and randomly divided into 13 groups. Fluorescent distribution and intensity were investigated at 2, 4, 6, 8, 12, 24 h, and 2, 4, 7, 14, 28 d and 2, 3 months after injecting the left posterior limb rear thigh muscles with 1.5 ?l 4 mg/ml DiI for one mouse. Results The labeling neurons were scattered from L2 level to S2 level and associated dorsal root ganglion (DRG), but the most were located at L4 to L6 section. The faint red fluorescence neurons were observed at dorsal root ganglion and cornu anterius medullae spinalis 6 h post-injection. The labeling neurons increased up to the 4th day. The fluorescent intensity enhanced gradually from 6 h to 24 h, then kept the intensity for 3 months. Conclusion It is a quick, precise, persistent method to trance and label the dorsal root ganglions sensory neuron and spinal motoneuron by injecting rear-thigh muscles with DiI, and the rate of labeling neurons can be improved by prolonging the tracing time properly. It is also provide basic data for clinical or experimental neuron label and location.