1101
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Huang Q, Liu S, Tang Y, Zeng F, Qian R. Amino acid sequencing of a trypsin inhibitor by refined 1.6 A X-ray crystal structure of its complex with porcine beta-trypsin. FEBS Lett 1992; 297:143-6. [PMID: 1551419 DOI: 10.1016/0014-5793(92)80346-i] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The stoichiometric complex formed between porcine beta-trypsin and the Momordica charantia, Linn. Cucurbitaceae trypsin inhibitor-A (MCTI-A) was crystallized and its X-ray crystal structure determined using molecular replacement method. The primary sequence and topology of the inhibitor was determined by recognizing the electron density and refined to a final R value of 0.167 (7.0-1.6 A) with RMS deviation of bond lengths from standard values 0.012 A. The sequence was compared with those obtained by other groups and was found to be similar to the squash proteinase inhibitor. Its spatial structure and the conformation of its primary binding segment from Cys-3I (P3) to Glu-7I (P3') which contains the reactive scissile bond Arg-5I C-Ile-6I N were also very similar with other squash family proteinase inhibitors.
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1102
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Tang Y, Cui Y, Dunn MH. Lithium triborate optical parametric oscillator pumped at 266 nm. OPTICS LETTERS 1992; 17:192-194. [PMID: 19784272 DOI: 10.1364/ol.17.000192] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
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1103
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Hiatt A, Tang Y, Weiser W, Hein MB. Assembly of Antibodies and Mutagenized Variants in Transgenic Plants and Plant Cell Cultures. GENETIC ENGINEERING 1992; 14:49-64. [PMID: 1368282 DOI: 10.1007/978-1-4615-3424-2_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
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1104
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Tang Y, Fredrickson TN, Chattopadhyay SK, Hartley JW, Morse HC. Lymphomas in mice with retrovirus-induced immunodeficiency. Curr Top Microbiol Immunol 1992; 182:395-8. [PMID: 1490377 DOI: 10.1007/978-3-642-77633-5_50] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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1105
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Tang Y, Danmin C, Durand LG. The synthesis of the aortic valve closure sound of the dog by the mean filter of forward and backward predictor. IEEE Trans Biomed Eng 1992; 39:1-8. [PMID: 1572676 DOI: 10.1109/10.108121] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The application of a new algorithm, the mean filter of forward and backward predictor, to synthesize the aortic component of the second heart sound (A2), according to an exponentially damped sinusoid model, is described. The resulting estimates of four modeling parameters composing each sinusoid of A2 (amplitude, damping factor, frequency, and phase) were used to synthesize the original aortic sounds. The synthesized sounds were then compared to the original sounds recorded on the thorax of six dogs and an error index was computed. The results show that the method is more precise than the forward predictor filter, the backward predictor filter, and the improved KT algorithm. The new algorithm is also highly stable and the error index between the original A2 and the synthesized waveforms is always less than 1%.
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1106
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Killick-Kendrick R, Tang Y, Killick-Kendrick M, Sang DK, Sirdar MK, Ke L, Ashford RW, Schorscher J, Johnson RH. The identification of female sandflies of the subgenus Larroussius by the morphology of the spermathecal ducts. PARASSITOLOGIA 1991; 33 Suppl:335-47. [PMID: 1841225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The complete spermathecae of 13 species of Larroussius were dissected and examined. The base of the duct of 4 species (aculeatus, guggisbergi, tobbi, wui) is bell-shaped: they are easily distinguished by differences in shape. Five other species (perniciosus, pedifer, longicuspis, perfiliewi, galilaeus) have lateral structures at the base of the duct: slight differences between perniciosus, pedifer and longicuspis distinguish these species: the structures of perfiliewi and galilaeus are the same. Species of a third group (neglectus, syriacus) have a common duct with no lateral structures: they are distinguishable by minor differences. Two species (ariasi, orientalis) from a fourth group with expanded distal parts of the duct; the size and shape of the expanded parts easily separates the species. The study shows a great variation in the morphology of the base of the spermathecal ducts of Larroussius and confirms the value of this feature in identifying otherwise indistinguishable females of the subgenus.
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1107
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Tang Y, Simpson LJ, Furtak TE. Ag(111) surface reconstruction studied by optical second-harmonic generation. PHYSICAL REVIEW LETTERS 1991; 67:2814-2817. [PMID: 10044562 DOI: 10.1103/physrevlett.67.2814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1108
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Tang Y, Hicks JB, Hilvert D. In vivo catalysis of a metabolically essential reaction by an antibody. Proc Natl Acad Sci U S A 1991; 88:8784-6. [PMID: 1924339 PMCID: PMC52594 DOI: 10.1073/pnas.88.19.8784] [Citation(s) in RCA: 66] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
We have established a growth selection requirement for a catalytic antibody with modest chorismate mutase activity. Conversion of (-)-chorismate into prephenate is the key step in the biosynthesis of the aromatic amino acids tyrosine and phenylalanine. Strains of the yeast Saccharomyces cerevisiae containing an insertion mutation in the structural gene for the enzyme chorismate mutase (EC 5.4.99.5) require exogenous supplements of these two amino acids for efficient growth. Intracellular expression of the heterologous antibody catalyst in one such strain, identified by random mutagenesis and genetic selection, provides a substantial growth advantage under auxotrophic conditions; complementation was not observed with an unrelated esterolytic antibody. In addition to demonstrating that tailored immunoglobulin catalysts can carry out vital biochemical reactions in vivo, these experiments provide a powerful selection assay for identifying genetic changes within the antibody molecule itself that augment chemical efficiency.
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1109
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Hein MB, Tang Y, McLeod DA, Janda KD, Hiatt A. Evaluation of immunoglobulins from plant cells. Biotechnol Prog 1991; 7:455-61. [PMID: 1367994 DOI: 10.1021/bp00011a011] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Expression of cDNA constructs encoding full-length mouse immunoglobulin chains with their native leader sequences or fusion constructs substituting the native leader with a pre-pro sequence derived from Saccharomyces cerevisiae yielded blocked N-termini on the gamma chain or the correct amino terminal sequence on the mature kappa chain. Lectin binding assays revealed that assembled immunoglobulin complexes contained a glycosylated heavy chain. The attached glycan was resistant to digestion by endoglycosidase H and its lectin binding pattern was distinguishable from that of the mammalian glycan. The results indicated processing of the immunoglobulin carbohydrate in the tobacco Golgi to yield a complex oligosaccharide. Secretion of antibody by protoplasts isolated from regenerated transgenic plants or from suspension callus cells was demonstrated by pulse-chase labeling experiments. When purified, the tobacco-produced antibody was found to possess the antigen binding and catalytic properties of the murine monoclonal antibody. Kinetic parameters (Km, Ki, Vmax, and kcat) of the tobacco-derived antibody were comparable to those of the mouse-derived antibody. The results in general show that the endomembrane system of tobacco cells possesses cognate mechanisms for the recognition of diverse leader sequences. These signals can be used to initiate the assembly, processing, and secretion by plant cells of complex foreign proteins.
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1110
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Tang Y. [Cyclic endometrial changes, ovulation and serum estradiol and progesterone levels in female sterility]. ZHONGHUA FU CHAN KE ZA ZHI 1991; 26:281-3, 322. [PMID: 1935407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Serial endometrial biopsies and determinations of serum E2 and P levels by radio-immunoassay were performed in 11 women with idiopathic sterility. B ultrasound was employed to monitor the development of follicles and the exact ovulation day. In 9 cases ovulation was observed and normal endometrial changes according to Noyes' criteria with normal cyclic changes of E2 and P levels were present in only 4 cases. 5 ovulated from follicles of smaller size and the secretory phase of the endometrium was delayed. The asynchronous development of endometrium associated with lowered E2 in the follicular phase was deemed to interfere with implantation even in the presence of normal fertilization. Two patients failed to ovulate on account of atretic follicle in one and LUFS in the other. The authors suggest that in idiopathic sterility, especially in the presence of atypical endometrium on the first day of menstruation the E2 levels in the follicular phase and endometrial status on the 3rd-4th day after ovulation should be given due attention.
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1111
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Bowdish K, Tang Y, Hicks JB, Hilvert D. Yeast expression of a catalytic antibody with chorismate mutase activity. J Biol Chem 1991; 266:11901-8. [PMID: 2050687] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The catalytic antibody 1F7 promotes the rearrangement of chorismate into prephenate. We cloned and sequenced the genes encoding this catalyst to determine the origin of the observed rates and specificity. The antibody cDNAs were modified and inserted into inducible expression vectors. Simultaneous intracellular expression of the light and truncated heavy chains in strains of the yeast Saccharomyces cerevisiae lacking natural chorismate mutase resulted in the production of properly folded and assembled Fab antibody. Assembly of the light and heavy immunoglobulin chains is roughly 60-70% efficient in our in vivo system, lagging behind light chain synthesis throughout log and stationary phase. Nevertheless, high intracellular levels of functional Fab antibody (0.1% of total cellular protein) were obtained with an ultra-high copy number plasmid. As yeast-derived 1F7(Fab) catalyzes the chorismate mutase reaction with the same specific activity as antibody isolated from the hybridoma, our expression system now makes possible the application of classical and "reverse" genetics to the study and improvement of this first-generation abzyme.
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1112
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Tang Y, Lichtenstein C, Cotterill S. Purification and characterisation of the TnsB protein of Tn7: a transposition protein that binds to the ends of Tn7. Nucleic Acids Res 1991; 19:3395-402. [PMID: 1648205 PMCID: PMC328340 DOI: 10.1093/nar/19.12.3395] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Tn7, a large bacterial transposon encodes 5 proteins required for its transposition. We report a rapid and easy purification of one of these proteins, TnsB, from an overexpression strain. This protein was shown to bind to the ends of Tn7, in a bandshift assay, in two distinct stages as a function of protein concentration. DNasel footprinting at each end of Tn7 showed that the TnsB recognition sequence, a set of 22 bp repeats, plus Tn7 termini are protected. Binding of TnsB appeared cooperative but was only observed above a threshold concentration of protein. ATP and Mg2+ had no effect on the pattern of protection, nor did addition of other Tn7-encoded proteins. Hydroxyl radical footprinting, performed at the right end, showed that TnsB binds preferentially to one side of the DNA helix.
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1113
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Tang Y, Xie Y, Chai H, Xiao B, Wang Y. [Observation of enzyme histochemistry and ultrastructure of brain in kindling rats with epilepsy induced by intraperitoneal injection of coriaria lactone]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1991; 22:39-42. [PMID: 1774033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Kindling model of epilepsy induced by intraperitoneal injection of Coriaria lactone (CL) was used in the experiment. The dose of CL was 1.25 mg/kg. Thirty rats in various periods of kindling were killed and the materials of cerebral cortex, hippocampus and cerebellum were drawn. The enzyme activities of AchE, NADHD, CCO, LDH, SDH, AcP, ANAE and AkP of these areas were observed with enzyme histochemical techniques. In another three kindled rats, two blank control rats and two NS control rats, the ultrastructure of neurons in hippocampus were observed. The results of experiments showed an increased activity of enzymes related to saccharometabolism and energy metabolism, indicating that the metabolism of brain in rats was increased by repeated kindling seizures. The mechanism of kindling seizure induced by CL may be related to inhibitory effect of CL on AchE activity of brain. The degeneration damage of brain neurons in kindled rats may result from using CL for a long time.
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1114
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Tang Y, Schwarting R, Stein H. [Proliferation of Reed-Sternberg cells in 5 Hodgkin's cell lines]. ZHONGHUA YI XUE ZA ZHI 1991; 71:78-80, 8. [PMID: 1647840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Using the monoclonal antibody Ki-67 that detects a cell proliferation-associated human nuclear antigen, incorporations of bromodeoxyuridine (Brud) and 3H-Thymidine, we studied the proliferative capacity of Reed-Sternberg (RS) cells in Hodgkin's cell lines L428, KM-H2, Holden, L540 and L591. The results revealed that in all cell lines, except L591, more than 55% of RS cells were found positive for Ki-67, and over 50% of them had Brud incorporation 5 days after cultivation. The positive score for 3H-Thymidine incorporation was low, and it is assumed that the time taken for 3H-Thymidine in cultivation was short. It shows that at least half of RS cells in these cell lines have proliferation-associated nuclear antigen or can synthesize DNA, and so they are proliferative.
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1115
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Stalcup AM, Faulkner JR, Tang Y, Armstrong DW, Levy LW, Regalado E. Determination of the enantiomeric purity of scopolamine isolated from plant extract using achiral/chiral coupled column chromatography. Biomed Chromatogr 1991; 5:3-7. [PMID: 2032020 DOI: 10.1002/bmc.1130050103] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The optical purity of scopolamine derived from Datura sanguinea was determined using coupled column chromatography. A C18 column was used to separate scopolamine from the additional alkaloids and other biological material present in the vegetal extract. The C18 column was coupled through a six-port switching valve to two beta-cyclodextrin columns in series which were used to resolve the scopolamine enantiomers. A single acetylated beta-cyclodextrin column gives equivalent results to the native cyclodextrin columns because of slightly higher enantioselectivity for scopolamine. A multistep extraction procedure is used to isolate scopolamine from the vegetal material. 4-6% of the scopolamine in the final extract was found to be the d enantiomer. Sample extracts as well as commercial scopolamine hydrobromide were treated under various conditions commonly encountered during typical commercial extraction procedures and analyzed in order to determine if the d enantiomer was present in the original material or if it was produced during the extraction process and, if so, determine which step and conditions contribute to racemization. Both the salt and the extract were found to be susceptible to racemization under basic conditions (greater than or equal to pH 9) although the extract appeared to be more susceptible than the salt. Tropic acid formed from the hydrolysis of scopolamine seemed to be completely racemized even though the remaining scopolamine was only partially racemized. Within experimental error, no d enantiomer was found in the original fresh plant material.
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1116
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Tang Y, Xie Y, Chai H, Chen Q. [A kindling model of epilepsy induced by intraperitoneal injection of coriaria lactone in rats]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1990; 21:304-6. [PMID: 2093070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Fifty adult male Sprague-Dawley rats were divided into five groups. Intraperitoneal injections of various doses of coriaria lactone (CL, 0.75, 1.25, 1.75, and 2.0 mg/kg) and normal saline were given respectively per 2 days. The behavior of the rats was observed and the ECoG was recorded by telemetric method. The results of experiments show that a kindling model of epilepsy can be established by intraperitoneal injection of CL in rats. This chronic experimental model is of value for application because it is easily established and the rate of being kindled is relatively high, but the mortality is low, and the kindling effect can last well. The model can avert the pathological change caused by artificial injury to brain, so it is advantageous to the research on neurochemistry and ultrastructure. In our experimental condition, it is optimal to select 1.25 mg/kg or 1.75 mg/kg as the dosage of CL for establishing kindling model.
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1117
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Pörtner HO, Boutilier RG, Tang Y, Toews DP. Determination of intracellular pH and PCO2 after metabolic inhibition by fluoride and nitrilotriacetic acid. RESPIRATION PHYSIOLOGY 1990; 81:255-73. [PMID: 2124717 DOI: 10.1016/0034-5687(90)90050-9] [Citation(s) in RCA: 129] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mean intracellular pH (pHi) and PCO2 (PiCO2) have been analysed based on pH and total CO2 measurements in tissue homogenates. Tissues were sampled from undisturbed worms (Sipunculus nudus), squid (Illex illecebrosus), trout (Salmo gairdneri), toads (Bufo marinus), and rats. Homogenate metabolism was inhibited by the addition of potassium fluoride and nitrilotriacetic acid (NTA). Model calculations revealed that the influence of dilution, medium buffers, and contamination by extracellular fluids was negligible. In white muscle tissue the resulting pHi values were virtually the same as found in studies using DMO (dimethyloxazolidinedione). If large fractions of mitochondria were present (e.g. in heart muscle), DMO derived pHi values were considerably higher, probably representing overestimates. Homogenate derived pHi values are concluded to represent the effective mean pHi by taking into account pH gradients, and the volumes and buffering of cellular compartments. High time resolution and small variability make this method especially useful to assess rapid changes in pHi, e.g. in exercising animals.
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1118
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McDonald DG, Tang Y, Boutilier RG. Acid and ion transfer across the gills of fish: mechanisms and regulation. CAN J ZOOL 1989. [DOI: 10.1139/z89-428] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This review examines the mechanisms and regulation of ion and acid transfers across the gills, focussing on freshwater fish. Apical ion-exchange mechanisms (i.e., [Formula: see text] and [Formula: see text] exchange) are shown to play an important though not exclusive role in acid–base transfers. Under some circumstances, for example when either [Formula: see text] or [Formula: see text] but not H+ levels in plasma are elevated, a second mechanism of acid–base transfer then becomes apparent. This mechanism is thought to involve diffusion of acid–base relevant and "strong" ions through paracellular channels. Factors that affect acid–base transfers across the gills include the external [NaCl] and the nature of the acid–base disturbance, the latter being at least as important as the magnitude of the disturbance. Catecholamines are shown to play an important role in the regulation of acid–base transfers across the gills, acting largely through activation of β-adrenergic receptors. Current evidence, nonetheless, suggests that other elements (e.g., α-receptors, adrenergic and cholinergic neurons) may also be involved.
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1119
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Ohtani R, Kaneko T, Kline LW, Labedz T, Tang Y, Pang PK. Localization of calcitonin gene-related peptide in the small intestine of various vertebrate species. Cell Tissue Res 1989; 258:35-42. [PMID: 2680100 DOI: 10.1007/bf00223142] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Calcitonin gene-related peptide (CGRP) was found extensively in the small intestine of both non-mammalian and mammalian vertebrates using radioimmunoassay and immunocytochemistry. By radioimmunoassay, the levels of CGRP in rats, mice, chickens, bullfrogs and rainbow trout were found to range from 91.5 to 419.1 ng/g tissue. To localize CGRP in the small intestine, we used three different tissue preparations for immunocytochemistry: whole-mount preparations, and frozen and Paraplast sections. The combination of three tissue preparations made it easier to visualize the three-dimensional structure and reduced the possibility of missing the immunoreaction. Immunoreactive cell bodies were found in the plexi in the mammalian species. Dense and regular networks of CGRP fibers were observed in the smooth muscle layers, when examined in whole-mount preparations. In non-mammalian species, however, immunoreactive cell bodies could not be detected, although immunoreactive fibers were present, forming less dense and regular networks. Our results indicate that CGRP-immunoreactive fibers are present in the smooth muscle layers of the intestine from fish to mammals, suggesting that CGRP may be involved in regulating gastrointestinal smooth muscles in vertebrates.
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1120
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Tang Y. [A research on the assurance of family planning and providing for the aged]. REN KOU YAN JIU = RENKOU YANJIU 1989:24-9. [PMID: 12159350] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
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1121
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Tang Y, McDonald DG, Boutilier RG. Adrenergic Regulation of Blood Acid-Base Status following Exhaustive Exercise in Seawater-Adapted Rainbow Trout, Salmo gairdneri. ACTA ACUST UNITED AC 1989. [DOI: 10.1086/physzool.62.4.30157939] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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1122
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Song XO, Liu YQ, Tang Y, Jiang YC, Chen WX. [Studies on the mutagenicity of amrinone and milrinone]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1989; 20:181-5. [PMID: 2591931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The mutagenicity of domestic new drugs amrinone and milrinone were studied by Ames test, micronucleus test of mouse bone marrow and chromosome aberration assay in CHO cells. The results were as follows: neither amrinone nor milrinone was mutagenic in the Ames test; in chromosome aberration assay, both gave positive results; in mouse micronucleus test, amrinone gave a positive result when mice were exposed to 0.8 LD50 dose, but milrinone gave a negative result. These results suggested that amrinone and milrinone did not induce gene mutation, but amrinone induced chromosome damage both in vitro and in vivo, while the chromosome-damaging activity of milrinone in vitro may be minimized by biodetoxication in vivo.
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1123
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Tang Y, Armstrong AJ, Mockler RC, O'Sullivan WJ. Free-expansion melting of a colloidal monolayer. PHYSICAL REVIEW LETTERS 1989; 62:2401-2404. [PMID: 10039976 DOI: 10.1103/physrevlett.62.2401] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1124
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Tzoganakis C, Tang Y, Vlachopoulos J, Hamielec AE. Measurements of residence time distribution for the peroxide degradation of polypropylene in a single-screw plasticating extruder. J Appl Polym Sci 1989. [DOI: 10.1002/app.1989.070370308] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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1125
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Sha DZ, Dou JH, Li F, Tang Y. [Studies on the relation of alkaloids in semen Strychni and its processing]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1989; 14:22-4, 62. [PMID: 2569879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
This paper reports the determination of strychnine and brucine in different parts of Semen Strychni (the seeds of Strychnos nux-vomica and S. pierriana), and makes a comparison of the contents between the crude forms and processed products of the two seeds. Based on the results, the authors have made some discussion about the relationship between the alkaloid distribution in Semen Strychni and its processing.
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1126
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Tang Y, Tzoganakis C, Hamielec AE, Vlachopoulos J. Peroxide crosslinking of LLDPE during reactive extrusion. ADVANCES IN POLYMER TECHNOLOGY 1989. [DOI: 10.1002/adv.1989.060090305] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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1127
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Wine PH, Tang Y, Thorn RP, Wells JR, Davis DD. Kinetics of aqueous phase reactions of the SO4−radical with potential importance in cloud chemistry. ACTA ACUST UNITED AC 1989. [DOI: 10.1029/jd094id01p01085] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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1128
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Zeng JZ, Liang DR, Tang Y, Yang YR, Zhang WD, Lu YP, Wei SF. [Determination of mannitol concentrations in plasma by colorimetry]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1988; 19:285-8. [PMID: 3150967] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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1129
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Tang Y, Boutilier RG. Correlation between catecholamine release and degree of acidotic stress in trout. THE AMERICAN JOURNAL OF PHYSIOLOGY 1988; 255:R395-9. [PMID: 3414834 DOI: 10.1152/ajpregu.1988.255.3.r395] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Exhaustive exercise in freshwater (FW) and seawater (SW) rainbow trout resulted in a marked and acute increase of plasma catecholamines. Immediately after exercise, epinephrine and norepinephrine concentrations in FW trout were 69 and 15 times the resting level, respectively; in SW trout, they were 46 and 11 times the resting value, respectively. Over the 1st h of recovery, the magnitude of the catecholamine surge in FW animals was about twice that of their SW counterparts. Correlated with this was an extracellular pH disturbance in FW trout, which was approximately twice as severe as in SW trout. Indeed, both the magnitudes and time courses of the plasma catecholamine responses were matched to those of the acid-base disturbances. Linear correlations were found to exist between the immediate depression of blood pH and the corresponding increases in plasma epinephrine and norepinephrine. We conclude that catecholamines are released into the plasma in proportion to the magnitude of the acid-base disturbance. The higher postexercise levels of plasma catecholamines in FW trout vs. SW appear to be a response to the greater acid-base disturbance in the FW animals.
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1130
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Tang Y, Gong N, Lu WX. Parameters of exponentially damped sinusoids in noise and their application to the analysis of visual evoked potentials. JOURNAL OF BIOMEDICAL ENGINEERING 1988; 10:331-5. [PMID: 3236853 DOI: 10.1016/0141-5425(88)90063-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The backward prediction and singular value (SV) truncation methods for estimating multiple exponentially damped real sinusoids in noise have been studied. The basic theory and algorithm are outlined, and the effect on the error of computational parameters, such as the sampling window, the sampling rate, the order of the prediction-error filter (PEF) and the truncated point of SV, were studied using simulated data. If the computational parameters are carefully chosen, the estimate of frequency and damping factor of a damped sinusoid is quite accurate (within a certain range of signal to noise (S/N) ratio). We use this method to estimate the parameters of visual evoked potentials (VEP) and then reconstructed them from estimated parameters according to the resonant model. The error between original VEP and the reconstructed waveform is within 5%. This method can be used in the analysis and recognition of various systems.
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1131
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Tang Y. [Quantitative determination of geniposide in Gardenia jasminoides Ellis and its processed products]. ZHONG YAO TONG BAO (BEIJING, CHINA : 1981) 1988; 13:18-20, 62. [PMID: 3203433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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1132
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Tang Y, Kuang DR, Wu R. Alpha-factor-directed synthesis and secretion of beta-subunit of human choriogonadotropin (beta-hCG) in yeast S. cerevisiae. SCIENTIA SINICA. SERIES B, CHEMICAL, BIOLOGICAL, AGRICULTURAL, MEDICAL & EARTH SCIENCES 1988; 31:179-86. [PMID: 2455341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
A couple of shuttle vectors (pYNA and pYNB), containing a sequence coding for the leader region of the alpha-factor precursor (alpha-factor leader sequence) and the origin of 2 micron circle, were constructed. The cDNA for the beta-hCG (145aa) was fused in phase to the 3'-end of the alpha-factor leader sequence and transformed into the yeast Saccharomyces cerevisiae. The yeast cells carrying this hybrid gene synthesized and secreted a protein with the immunoactivity of beta-hCG in an amount of 45 micrograms per liter of culture. The preliminary characterization of this protein is also reported in this paper.
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1133
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Tang Y, Nolan S, Boutilier RG. Acid-base regulation following acute acidosis in seawater-adapted rainbow trout, Salmo gairdneri: a possible role for catecholamines. J Exp Biol 1988; 134:297-312. [PMID: 3128624 DOI: 10.1242/jeb.134.1.297] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A fall in blood pH was induced by intra-arterial infusion of HCl in seawater-adapted rainbow trout (Salmo gairdneri). The acute acidosis resulting from HCl infusion caused a short-lived decrease in plasma bicarbonate concentration ([HCO3-]) and an increase in arterial CO2 tension (PaCO2). Erythrocyte pH and bicarbonate concentrations were not significantly altered by the infusion of acid. Injection of acid did, however, stimulate a branchial net H+ efflux which could be primarily accounted for by a net uptake of bicarbonate equivalent ions from the environmental water. Acid infusion of animals pre-treated with the beta-adrenergic blocking agent, propranolol, induced a similar pattern of change in plasma acid-base status. However, the recovery of plasma pH and restoration of plasma [HCO3-] were slower than in animals infused with acid alone. Red cell pH fell significantly in the face of plasma acidosis in the beta-blocked animals. Erythrocyte [HCO3-] showed a similar pattern of change to that of erythrocyte pH. Branchial net H+ efflux increased to a lesser extent following acid infusion in animals treated with propranolol. We conclude that catecholamines released into the bloodstream during periods of acute acidosis may play an important role in facilitating branchial H+ efflux in seawater-adapted rainbow trout.
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1134
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John ER, Tang Y, Brill AB, Young R, Ono K. Response
: Do 15 Million Cat Neurons Mediate the Memory of a Circle and a Star? Science 1987. [DOI: 10.1126/science.238.4833.1587-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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1135
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John ER, Tang Y, Brill AB, Young R, Ono K. Response
: Do 15 Million Cat Neurons Mediate the Memory of a Circle and a Star? Science 1987. [DOI: 10.1126/science.238.4833.1587.b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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1136
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John ER, Tang Y, Brill AB, Young R, Ono K. Do 15 Million Cat Neurons Mediate the Memory of a Circle and a Star? Science 1987; 238:1587-8. [PMID: 17784295 DOI: 10.1126/science.238.4833.1587-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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1137
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Chen H, Tang Y, Wei F, Noordhoff S. Venous bridge used in free flap transfer for the lower leg in the presence of venous hypertension: a case report. BRITISH JOURNAL OF PLASTIC SURGERY 1987; 40:526-7. [PMID: 3676585 DOI: 10.1016/s0007-1226(87)90088-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Reconstruction with free flaps for the lower leg in the presence of venous thrombosis or venous hypertension has a high risk of failure. We describe the use of the contralateral leg for venous drainage through a pedicled skin bridge containing a tributary of the long saphenous vein. The recipient artery was a main artery of the ipsilateral leg. Two weeks later, once there was a well-established venous communication between flap and recipient site, the venous bridge was divided. Because the arterial inflow to the flap was not interrupted by the division of the skin bridge, the flap has good viability and good resistance to infection or ulceration 3 years later.
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1138
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Li G, Chen Z, Zeng J, Tang Y, Lin G, Zhang R, Xuan J, Chi Z, Tsao T. X-ray crystallographic studies on the complex of mung bean trypsin inhibitor with porcine trypsin. Acta Crystallogr A 1987. [DOI: 10.1107/s0108767387084551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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1139
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Chen Z, Li G, Zeng J, Tang Y, Lu G, Wei X, Lin G, Zhang R, Xuan J, Chi Z, Tsao T. Crystal structure determination and molecular model of mung bean trypsin inhibitor lys active fragment–bovine trypsin (MBILF–BTRY) complex at 3.0 Å resolution. Acta Crystallogr A 1987. [DOI: 10.1107/s0108767387084563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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1140
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Huang Q, Chen Z, Li G, Tang Y, Qian R, Zeng F, Wang Y. Crystallization of the complex of Momodica charantiaL. trypsin inhibitor (MTI-1) with porcine trypsin. Acta Crystallogr A 1987. [DOI: 10.1107/s0108767387084575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023] Open
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1141
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Xu X, Guan Y, Tang Y, Wang S. Study of structure–activity relationship for some isomers of cinnamamides. Acta Crystallogr A 1987. [DOI: 10.1107/s0108767387084253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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1142
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Guo HY, Tang Y, Li ZR, Yan GH, Zhang ZP. [Studies on pyridonecarboxylic acids as antibacterial agents. V. Synthesis and antibacterial activity of pivaloyloxymethyl 1-ethyl-6-fluoro-1,4-dihydro-4-oxo-7-(4-methyl-1-piperazinyl) quinoline-3-carboxylate and its analogues]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1987; 22:373-6. [PMID: 3687464] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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1143
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Abstract
The physical changes representing a memory are believed to be localized to specific neurons, widely distributed in multiple parallel pathways in the brain. 2-Fluorodeoxyglucose, labeled with two discriminable radioactive tracers, was used to construct quantitative metabolic maps in split-brain cats during a visual task. One side of the brain served to estimate the metabolic variability of nonspecific influences. The other side was used to map metabolic changes related to the presence of previously learned visual cues, as well as changes related to nonspecific influences, in the same periods of time. When the two sides were compared, between 5 million and 100 million neurons (depending upon the significance level selected) were identified in which activity increased during presentation of the familiar cues. The wide distribution of these neurons throughout the brain is compatible with prior evidence of a distributed memory system. However, the large number of neurons involved is difficult to reconcile with theories in which individual neurons are dedicated to specific memories.
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1144
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Tang Y, Beale PD, Mockler RC, O'Sullivan WJ. Observation of a correlation length finite-size effect in Rayleigh scattering from thin critical fluid films. PHYSICAL REVIEW LETTERS 1986; 56:480-483. [PMID: 10033203 DOI: 10.1103/physrevlett.56.480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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1145
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Tang Y, Bernstein JJ. Rapid rejection of fetal chick neocortical xenografts into the spinal cord of adult rats. Neurosci Lett 1986; 63:81-5. [PMID: 3951741 DOI: 10.1016/0304-3940(86)90017-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Xenografts of embryonic day 5 chick cortex were placed into the dorsal column of the spinal cord of 15 adult male Sprague-Dawley rats. This implantation site is known to support comparable E11 rat cortex for months. At 1 DPI (day postoperative), transplanted chicken cortex formed neuroepithelia with a surround of transplanted cells. By 3 DPI, all transplanted cells contained cytoplasmic lipid droplets or lysosomes, as well as necrotic cells. By 7 DPI, the fetal chicken cortical xenograft had necrosed or was phagocytized. The rapid cross-class xenograft rejection is unique since grafts of various rodent tissues tend to survive in the adult rodent central nervous system.
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1146
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Hoovler DW, Tang Y, Bernstein JJ. Viability of mature superior cervical ganglia transplants in peripheral nerve of adult rat. Brain Res 1985; 348:168-74. [PMID: 4063822 DOI: 10.1016/0006-8993(85)90374-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Allografts of mature rat superior cervical ganglia (SCG) survived for up to 120 days following transplantation to regenerating and degenerating peripheral nerves of adult rats. Transplants contained the constituents of normal superior cervical ganglia and there was evidence of outgrowth of catecholamine containing fibers from the transplants. However, fibers did not attain the length necessary to enter peripheral muscles and no muscle response could be elicited by electrical stimulation of the implanted nerve where the transplanted mature SCG was the only source of nerve fibers.
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1147
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Fan Z, Tang Y, Liang ZJ. [An on-line microprocessor-based cardiac cell transmembrane potential analyzer]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1985; 37:395-9. [PMID: 3837337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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1148
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Yang CZ, Zhu MF, Zhao XT, Tang Y. Preliminary study of the effect of "764-1" eyedrops on the biochemical constituents of corneal scar in rabbits. J TRADIT CHIN MED 1985; 5:47-50. [PMID: 3849631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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1149
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Chen WC, Zhou Q, Wang HR, Chen G, Tang Y, Pu QX, Wang ZS, Liang ZJ. [Effects of low magnesium and magnesium-free solutions on action potentials of isolated right ventricular muscle cell in the guinea pig]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1985; 37:96-100. [PMID: 4095553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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1150
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Bernstein JJ, Tang Y. Structure and function of fetal cortex implanted into degenerating peripheral nerve of adult rat. Brain Res 1984; 324:243-51. [PMID: 6529619 DOI: 10.1016/0006-8993(84)90034-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
The growth, differentiation and function of E11 fetal cortex was studied over 4 months after implantation into the degenerating nerve to the biceps femoris muscle of 70 rats. At 7 days postimplantation (DPI) the implant formed a neuroepithelium which contained mainly undifferentiated cells within a reconstituted perineurium. At 14-21 DPI the neurons contained differentiated, mature nuclei, poorly developed Nissl bodies and normal cytoplasmic organelles. Neuroglia were also observed with typical nuclei and a dense cytoplasmic ground. At 30 days the implants reached their greatest degree of differentiation. Neurons had mature nuclei and cytoplasmic organelles. There were few axosomatic synapses or neuronal cell processes. Neuroglia were prominent with many cell processes. The neuropil contained myelinated and unmyelinated nerve fibers, dendrites and many axodendritic synapses. At 40-50 DPI the neurons and neuronal cell processes were degenerating. At 60-120 DPI the implant contained only neuroglia. Stimulation of only the implant resulted in biceps femoris muscle contraction in 5 animals at 30 DPI and one animal at 40, 45 and 50 days. Injection of 10 microliter of WGA-HRP into the biceps femoris muscle resulted in at least 20 neurons in 3 30-day implants that contained HRP reaction product. These data show that fetal cortical neurons can assume functions different from normal, functionally reinnervate adult muscle and can differentiate and form an ectopic nervous system for at least 30-days after implantation into a degenerating adult host peripheral nerve.
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