101
|
Liu DX, Tibbles KW, Cavanagh D, Brown TD, Brierley I. Involvement of viral and cellular factors in processing of polyprotein encoded by ORF1a of the coronavirus IBV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1995; 380:413-21. [PMID: 8830517 DOI: 10.1007/978-1-4615-1899-0_67] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
102
|
Liu DX, Brierley I, Brown TD. Identification of a trypsin-like serine proteinase domain encoded by ORF 1a of the coronavirus IBV. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1995; 380:405-11. [PMID: 8830516 DOI: 10.1007/978-1-4615-1899-0_66] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
|
103
|
Lian P, Liu DX, Sun RH, Yang GC, Jia LS, Xu YK. Correlative study on findings of dynamic myelography and surgical operation in non-bony lumbar spinal canal stenosis. Chin Med J (Engl) 1994; 107:924-8. [PMID: 7882732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The authors performed dynamic lumbar myelography with Omnipaque on 110 patients from 1990 to 1992, of them, 33 cases were diagnosed as non-bony lumbar spinal canal stenosis according to contrast medium defect seen on the lateral view of the myelogram. All such cases were operated on and their dynamic pathological findings during the operation were recorded to compare with the abnormal findings observed on the myelograms, there was a high coincidence rate of 88.7%. The authors believe that the fibrous degenerative changes make up the basis of dural sac compression and the dynamic compression in the spinal canal plays a very important role in causing the severity of the stenosis. As the dynamic pathological findings on the myelograms can not be well demonstrated on CT scanning and MR imaging, the dynamic lumbar myelography should be the method of choice for use in some cases.
Collapse
|
104
|
Zhou J, Huang DY, Liu DX. [Specific binding sites of [3H] cortisol and [3H] dexamethasone in rat liver cell membrane]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1994; 46:488-94. [PMID: 7846549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
By using [3H] cortisol and [3H] dexamethasone (DEX), a class of specific binding sites of glucocorticoids (GC) in rat liver cell membrane was observed. These binding sites had saturability, high affinity and low capacity. The kinetic parameters of [3H] cortisol and [3H] DEX were: Kd = 12.84 +/- 6.58 nmol/L (n = 4) and 40.27 +/- 23.44 nmol/L (n = 3) respectively; Bmax = 2.57 +/- 1.84 pmol/mg protein and 0.64 +/- 0.18 pmol/mg protein respectively (mean +/- SE). The Kd obtained from the kinetic studies was corresponding to the results of Scatchard analysis. Scatchard plots from the equilibrium experiments showed the straight line. The Hill coefficients were 0.9880 and 0.9990 respectively. The competitive displacement experiments indicated that cortisol possessed the higher specificity for the [3H] cortisol binding sites than other tested steroids (prednisolone, progesterone, RU486, DEX). The competitive ability of cortisol was at least 40 folds higher than mentioned steroids. By means of autoradiography technique, the existence of [3H] cortisol labelled particles on the liver cell membrane was found.
Collapse
|
105
|
Liu DX, Brierley I, Tibbles KW, Brown TD. A 100-kilodalton polypeptide encoded by open reading frame (ORF) 1b of the coronavirus infectious bronchitis virus is processed by ORF 1a products. J Virol 1994; 68:5772-80. [PMID: 8057459 PMCID: PMC236981 DOI: 10.1128/jvi.68.9.5772-5780.1994] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
The genome-length mRNA (mRNA 1) of the coronavirus infectious bronchitis virus (IBV) contains two large open reading frames (ORFs), 1a and 1b, with the potential to encode polypeptides of 441 and 300 kDa, respectively. The downstream ORF, ORF 1b, is expressed by a ribosomal frameshifting mechanism. In an effort to detect viral polypeptides encoded by ORF 1b in virus-infected cells, immunoprecipitations were carried out with a panel of region-specific antisera. A polypeptide of approximately 100 kDa was precipitated from IBV-infected, but not mock-infected, Vero cells by one of these antisera (V58). Antiserum V58 was raised against a bacterially expressed fusion protein containing polypeptide sequences encoded by ORF 1b nucleotides 14492 to 15520; it recognizes specifically the corresponding in vitro-synthesized target protein. A polypeptide comigrating with the 100,000-molecular-weight protein (100K protein) identified in infected cells was also detected when the IBV sequence from nucleotides 8693 to 16980 was expressed in Vero cells by using a vaccinia virus-T7 expression system. Deletion analysis revealed that the sequence encoding the C terminus of the 100K polypeptide lies close to nucleotide 15120; it may therefore be generated by proteolysis at a potential QS cleavage site encoded by nucleotides 15129 to 15135. In contrast, expression of IBV sequences from nucleotides 10752 to 16980 generated two polypeptides of approximately 62 and 235 kDa, which represent the ORF 1a stop product and the 1a-1b fused product generated by a frameshifting mechanism, respectively, but no processed products were observed. Since the putative picornavirus 3C-like proteinase domain is located in ORF 1a between nucleotides 8937 and 9357, this observation suggests that deletion of the picornavirus 3C-like proteinase domain and surrounding regions abolishes processing of the 1b polyprotein. In addition, the in vitro translation and in vivo transfection studies also indicate that the ORF 1a region between nucleotides 8763 and 10720 contains elements that down-regulate the expression of ORF 1b.
Collapse
|
106
|
Lian P, Sun RH, Liu DX. [Myelographic diagnosis and treatment of lumbosacral nerve root anomalies]. ZHONGHUA WAI KE ZA ZHI [CHINESE JOURNAL OF SURGERY] 1994; 32:407-9. [PMID: 7842977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Altogether 480 patients were examined with myelography in the study from 1987 to 1992 and 28 cases having anomalous lumbosacral nerve roots with other concomitant diseases were found. The anomalies were classified three types based on myelographic findings. Type 1, root sleeve displacement; Type 2, a, roots through one foramen; b, roots through two foramina; c, roots through three foramina; Type 3, double roots through one foramen. All patients were proved and treated during operation. The results of treatment were good (92.8%). We considered that most lumbosacral nerve roots anomalies were asymptomatic, however, when they were compressed by degenerative canal tissue, classic nerve root pain appeared eventually. Myelography is helpful to its diagnosis and treatment.
Collapse
|
107
|
Liu DX, Gompels UA, Foa-Tomasi L, Campadelli-Fiume G. Human herpesvirus-6 glycoprotein H and L homologs are components of the gp100 complex and the gH external domain is the target for neutralizing monoclonal antibodies. Virology 1993; 197:12-22. [PMID: 7692666 DOI: 10.1006/viro.1993.1562] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Previous studies have shown that monoclonal antibody (MAb) 2E4 neutralizes infectivity of human herpesvirus-6 (HHV-6) and also inhibits virus-induced T-lymphocyte syncytia formation. Here we characterize two additional MAbs, 1D3 and 5E7, which have similar properties, and identify the glycoprotein targets. The MAbs could immunoprecipitate and immunofluorescence glycoprotein from both A and B variant strain groups of HHV-6. In reactions with infected cells the MAbs immunoprecipitated a complex of glycoproteins, the "gp100" complex, composed of a major glycoprotein species of 100,000 M(r) and minor components of 80,000 M(r) and 32,000 M(r). We show that the 100,000 M(r) product and most likely the 80,000 M(r) correspond to the HHV-6 homologue of herpes simplex virus-1 (HSV-1) glycoprotein H (gH) while the 32,000 M(r) species corresponds to the glycoprotein L (gL) equivalent. All three MAbs could specifically immunoprecipitate either gH expressed on its own in fibroblasts or a complex of gH and gL co-expressed, but could not immunoprecipitate gL expressed on its own. Consistent with these results, the MAbs could recognize gH in an immunofluorescence assay but not gL. Therefore although the MAbs recognized the complex of glycoproteins, they appeared specific for gH. The HHV-6 glycoproteins were produced in a transient expression system induced by T7-vaccinia virus. Immunoprecipitations were carried out in comparisons with an "epitope-tagged" gH, a recombinant glycoprotein designed to contain at the N-terminus the linear epitope for MAb LP14, raised originally against HSV-1 glycoprotein gD. The epitope-tagged gH was also used as a positive control in determining the domain of HHV-6 gH to which MAbs 2E4, 1D3 and 5E7 were directed. Two gH deletions were constructed, one deleting sequences which may serve as a transmembrane and cytoplasmic anchor domains, the second deleting also part of the external domain. MAb LP14 could immunoprecipitate both HHV-6 gH deletions but the gp100 MAbs recognized only the full-length product or the intact external domain minus the transmembrane and cytoplasmic domains. This indicated the epitopes for these MAbs are contained in the external domain of gH, consistent with the MAbs action in neutralization of virion infectivity and inhibition of virus to cell spread by T-lymphocyte fusion.
Collapse
|
108
|
Liu DX, Gompels UA, Nicholas J, Lelliott C. Identification and expression of the human herpesvirus 6 glycoprotein H and interaction with an accessory 40K glycoprotein. J Gen Virol 1993; 74 ( Pt 9):1847-57. [PMID: 8397282 DOI: 10.1099/0022-1317-74-9-1847] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
In herpes simplex virus (HSV) the small secreted glycoprotein gL forms a heterodimer with the transmembrane envelope glycoprotein gH. Here we identify the human herpesvirus 6 (HHV-6) gL gene, express HHV-6 gL and gH homologues, and examine interactions between HHV-6 gH and gL. The HHV-6 gL gene encoded a glycoprotein with an amino acid sequence which showed closest similarity to the human cytomegalovirus (HCMV) gL homologue (18% identity). Products of HHV-6 gH and gL genes were characterized in an in vitro transcription-translation system and in a transient in vivo expression system. Both gH and gL were transcribed and translated in vitro to give products of apparent M(r) of 65K and 28K in SDS-PAGE, and these could be processed by addition of microsomes to 110K and 40K, respectively. To study gH/gL interactions, gH was tagged with the nine amino acid epitope for monoclonal antibody LP14 (anti-HSV-1 gD). LP14 and a human serum sample specifically immunoprecipitated gH and a stable complex of gH and gL co-expressed in an in vivo vaccinia virus-T7 system. The gH and gL produced in this in vivo expression system corresponded to the M(r)s of the fully processed glycoproteins identified in the in vitro system. The gH expressed together with gL was recognized by human sera more easily than when examined on its own in immunofluorescence assays. Dual expression of gH and gL in transfected T lymphocytes (JJhan) caused reactions with 75% of human sera tested (12 HHV-6-positive, HCMV-negative serum samples), but gL expressed alone was not recognized by these sera. The immunofluorescence studies also showed that the glycoproteins were localized in Golgi-like bodies in fibroblasts, but occurred throughout the endoplasmic reticulum in T lymphocytes, the normal cellular target for HHV-6. These results show the identification of the HHV-6 homologue to the HCMV and HSV gL genes, identification and production of HHV-6 gH and gL expressed both in vitro and in vivo, complex formation between these glycoproteins, and evidence that this complex may be localized differently in fibroblasts as compared to T lymphocytes and that it is immunogenic.
Collapse
|
109
|
Liu DX, Gu JF. [Effects of vitamin E on bio-membranes]. SHENG LI KE XUE JIN ZHAN [PROGRESS IN PHYSIOLOGY] 1993; 24:83-6. [PMID: 8332877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
|
110
|
Liu DX, Inglis SC. Internal entry of ribosomes on a tricistronic mRNA encoded by infectious bronchitis virus. J Virol 1992; 66:6143-54. [PMID: 1527853 PMCID: PMC241492 DOI: 10.1128/jvi.66.10.6143-6154.1992] [Citation(s) in RCA: 78] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
mRNA3 specified by the coronavirus infectious bronchitis virus appears to be functionally tricistronic, having the capacity to encode three small proteins (3a, 3b, and 3c) from separate open reading frames (ORFs). The mechanism by which this can occur was investigated through in vitro translation studies using synthetic mRNAs containing the 3a, 3b, and 3c ORFs, and the results suggest that translation of the most distal of the three ORFs, that for 3c, is mediated by an unconventional, cap-independent mechanism involving internal initiation. This conclusion is based on several observations. A synthetic mRNA whose peculiar 5' end structure prevents translation of the 5'-proximal ORFs (3a and 3b) directs the synthesis of 3c normally. Translation of 3c, unlike that of 3a and 3b, was insensitive to the presence of the 5' cap analog 7-methyl-GTP, and it was unaffected by alteration of the sequence contexts for initiation on the 3a and 3b ORFs. Finally, an mRNA in which the 3a/b/c infectious bronchitis virus coding region was placed downstream of the influenza A virus nucleocapsid protein gene directed the efficient synthesis of 3c as well as nucleocapsid protein, whereas initiation at 3a and 3b could not be detected. Expression of the 3c ORF from this mRNA, however, was abolished when the 3a and 3b coding region was deleted, indicating that 3c initiation is dependent on upstream sequence elements which together may serve as a ribosomal internal entry site similar to those described for picornaviruses.
Collapse
|
111
|
Liu DX, Wada A, Huang L. Potentiation of the humoral response of intravenous antigen by splenotropic liposomes. Immunol Lett 1992; 31:177-81. [PMID: 1740352 DOI: 10.1016/0165-2478(92)90143-c] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We have recently described that large liposomes composed of egg phosphatidylcholine (PC), cholesterol (chol) and monosialoganglioside GM1 show elevated accumulation in the red pulp of the spleen when they are i.v. administered into mice. Up to 50% of the injected dose was found in spleen at 4 h post injection. In this report, we have investigated the potential application of such liposomes in the stimulation of anti-lysozyme response in mice. Lysozyme entrapped in the splenotropic liposomes composed of PC/chol/GM1 showed higher efficiency in potentiating the humoral response than that of either free lysozyme or lysozyme entrapped in hepatotropic liposomes composed of PC/chol. The results demonstrate that high levels of i.v. antigen delivery by liposomes to the splenic macrophage instead of the liver Kupffer cells is important in the liposomal adjuvanticity. The antibody elicited by the liposome entrapped antigen was mainly IgG1 subtype.
Collapse
|
112
|
Liu DX, Inglis SC. Identification of two new polypeptides encoded by mRNA5 of the coronavirus infectious bronchitis virus. Virology 1992; 186:342-7. [PMID: 1309280 PMCID: PMC7130825 DOI: 10.1016/0042-6822(92)90094-6] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The second smallest subgenomic messenger RNA, mRNA5, of the coronavirus infectious bronchitis virus includes in its "5' unique region" two separate open reading frames (5a and 5b), whose coding function has not so far been established, and thus it may represent a dicistronic messenger RNA. We report here that two polypeptides with the sizes expected for the 5a and 5b products can be synthesised by in vitro translation of a single artificial mRNA containing both the 5a and 5b ORFs. To establish whether these polypeptides represent genuine virus gene products, both the 5a and 5b coding sequences were expressed as bacterial fusion proteins, and these were used to raise monospecific antisera. Antisera raised against both the 5a and 5b-specific sequences recognized specifically proteins of the expected size in infectious bronchitis virus-infected chicken kidney and Vero cells, indicating that 5a and 5b do represent genuine virus genes, and suggesting that mRNA5 is indeed functionally dicistronic.
Collapse
|
113
|
Abstract
A highly purified radiolabeled preparation of the coronavirus infectious bronchitis virus (IBV) was analyzed, by immunoprecipitation with monospecific antisera, for the presence of a series of small virus proteins recently identified as the products of IBV mRNAs 3 and 5. One of these, 3c, a 12.4K protein encoded by the third open reading frame of the tricistronic mRNA3 was clearly detectable and was found to cofractionate with virion envelope proteins on detergent disruption of virus particles. These results, together with the hydrophobic nature of 3c and its previously demonstrated association with the membranes of infected cells, suggest strongly that 3c represents a new virion envelope protein, which may have counterparts in other coronaviruses.
Collapse
|
114
|
Liu DX, Cavanagh D, Green P, Inglis SC. A polycistronic mRNA specified by the coronavirus infectious bronchitis virus. Virology 1991; 184:531-44. [PMID: 1653486 PMCID: PMC7131956 DOI: 10.1016/0042-6822(91)90423-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The third largest of the nested set of subgenomic mRNAs (mRNA3) from the coronavirus infectious bronchitis virus (IBV) contains three separate open reading frames (3a, 3b, and 3c) which are not present on the next smallest of the mRNAs, suggesting that this mRNA may be functionally polycistronic. However, although a protein product has been identified from the 3c open reading frame, to date the coding function of 3a and 3b has not been established. We present nucleotide sequence data suggesting that each of the three open reading frames is conserved in a variety of different IBV strains and further show, through the preparation of monospecific antisera against bacterial fusion proteins, that IBV-infected cells contain small amounts of the products of these ORFs. In vitro translation studies using synthetic mRNAs containing the 3a, 3b, and 3c open reading frames suggest strongly that all three proteins can be translated from a single molecular species, and expression studies carried out in intact cells support this conclusion. Thus mRNA3 of IBV appears to be functionally tricistronic.
Collapse
|
115
|
Yin XJ, Liu DX, Wang HC, Zhou Y. A study on the mutagenicity of 102 raw pharmaceuticals used in Chinese traditional medicine. Mutat Res 1991; 260:73-82. [PMID: 2027343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The mutagenic potential of traditional Chinese drugs was studied. After extraction with boiling water and frozen vacuum drying, preparations from 102 raw drugs were tested with the Ames test, and the micronucleus and chromosomal aberration assays in mice in vivo. Astragalus mongholicus Bunge (+S9), Sophora japonica L. (+/- S9) and Eucommia ulmoides Oliv. (+/- S9) were found to significantly induce His+ revertants in Salmonella typhimurium TA98 and/or TA100. Besides these 3, 10 other extracts were positive in the chromosomal aberration and micronucleus assays in mice. They are Datura metal L., Artemisia capillaris Thunb., Carthamus tinctorius L., Forsythia suspensa Thumb., Rehmannia glutinosa f. Hueichingensis (fermented), Paeonia suffruticosa Andr., Platycodon grandiflorum Jacq. DC., Cinnamomum mairei Levl., Notopterygium incisium Ting., and Sophora flavescens Ait. The relevance of these findings is discussed.
Collapse
|
116
|
Jin H, Yuan ZY, Du XH, Su G, Zhang L, Wang MX, Dong Y, Liu DX, Zou WZ, Wang SL. Relation between plasma atrial natriuretic peptide (ANP) and glomerular ANP receptors in 5/6 nephrectomized rats. Chin Med J (Engl) 1990; 103:794-9. [PMID: 2176581] [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
Chronic renal failure (CRF) was induced in male wistar rats (Group I) by 5/6 nephrectomy and the sham-operated ones served as control (Group II). The results showed that in Group I, plasma atrial natriuretic peptide (ANP) levels increased progressively as the Scr was elevated. Plasma R-A rose simultaneously compared to the normal (P less than 0.001). At the 20th week after operation, urine volume and Na decreased significantly (P less than 0.05). The number of glomerular receptors decreased markedly at the 12th week (P less than 0.05) and 20th week (P less than 0.01). Our data suggest that in 5/6 nephrectomized rats, the elevation of plasma ANP level might be partly caused by the damage of glomerular ANP receptors, and the elevated plasma ANP could not play its role in diuresis, natriuresis, blood pressure depression and R-A inhibition as a result of the damage of kidney ANP receptors.
Collapse
|
117
|
Liu DX, Wood GW, Desiderio DM. Proenkephalin A and proopiomelanocortin peptides in human cerebrospinal fluid. JOURNAL OF CHROMATOGRAPHY 1990; 530:235-52. [PMID: 1964161 DOI: 10.1016/s0378-4347(00)82328-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Precursors to beta-endorphin (BE) and methionine enkephalin (ME), and proteolytic enzymes that cleave those BE and ME precursors to BE and ME, were determined in several milliliters of human cerebrospinal fluid. Endogenous peptides were purified by reversed-phase high-performance liquid chromatography (HPLC), and were detected with radioreceptor assay (RRA), radioimmunoassay, and mass spectrometry (MS). Total opioid receptor activity measurements and the profile of HPLC-receptor activity of human CSF samples were both used to monitor neuropeptide metabolism. MS data linked the molecular ion of ME to a unique fragment ion. A later-eluting fraction (84 min) in a 90-min HPLC gradient appeared in all HPLC-RRA profiles, contained opioid receptor activity that displaced [3H]etorphine, and the quantitative and qualitative patterns of opioid receptor activity in those profiles both changed within the few minutes that elapsed between acquiring the first and second cerebrospinal fluid samples. That 84-min fraction contained precursors to opioid peptides and was fractionated further with a more shallow 120-min HPLC gradient into three sections that displayed delta-opioid receptor-preferring activity, using [3H]ME as ligand. These three sections were hydrolyzed separately with human cerebrospinal fluid as the source for endogenous neuropeptides to yield products that correlated to immunoreactive BE in section I and immunoreactive ME in section III.
Collapse
|
118
|
Yang FS, Han JS, Dong Y, Liu DX. A technique for temporal bone sections using non-decalcified frozen guinea pig cochleas: a study of succinic dehydrogenases. Eur Arch Otorhinolaryngol 1990; 247:283-6. [PMID: 2393561 DOI: 10.1007/bf00176537] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
We have developed a technique for sectioning temporal bones and have studied non-decalcified frozen guinea pig cochleas to localize succinic dehydrogenases. The technique is simple and practicable. The 6-microns sections used preserve both fine cochlear structure and satisfactory histochemical localization for identifying the succinic dehydrogenases. The technique can also be extended to immunological test, detecting transmitters and investigating enzymes in the cochlea.
Collapse
|
119
|
Liu DX, Dass C, Wood G, Desiderio DM. Opioid and tachykinin peptides, and their precursors and precursor-processing enzymes, in human cerebrospinal fluid. J Chromatogr A 1990; 500:395-412. [PMID: 2329143 DOI: 10.1016/s0021-9673(00)96081-3] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Opioid and tachykinin neuropeptides, which were derived from two biological sources (intact, and released from their corresponding precursors by the action of human cerebrospinal fluid (CSF) neuropeptidases), were characterized in human CSF by using a combination of post-high-performance liquid chromatographic (HPLC) detection techniques. Peptides were separated using gradient and isocratic reversed-phase HPLC. Radioimmunoassay measured immunoreactivity corresponding to several different individual neuropeptides including methionine enkephalin, leucine enkephalin, substance P and beta-endorphin. Commercial enzymes (trypsin, carboxypeptidase B) were used to release methionine- and leucine-enkephalin from precursors. Human CSF also served as a source of endogenous neuropeptidases. Mass spectrometry produced fragment ions that corroborated the amino acid sequence of methionine enkephalin and of substance P derived from both sources (intact, from precursors). These results demonstrated the presence of endogenous intact neuropeptides, several different neuropeptide-containing precursors and appropriate precursor-processing enzymes in human CSF for precursors of methionine enkephalin, leucine enkephalin, beta-endorphin1-31 and substance P.
Collapse
|
120
|
Liu DX, Valadez V, Sorkin LS, McAdoo DJ. Norepinephrine and serotonin release upon impact injury to rat spinal cord. J Neurotrauma 1990; 7:219-27. [PMID: 1707100 DOI: 10.1089/neu.1990.7.219] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Microdialysis sampling was used to characterize the release of norepinephrine and serotonin upon impact injury to the rat spinal cord. Increases in extracellular norepinephrine concentrations in response to injury were small and of short duration. In contrast, serotonin concentrations quickly rose 35-90 times following injury and took 30-45 min to return to control levels. Bleeding caused by injury was probably the major source of the increased serotonin levels. Our results allow a role for serotonin in secondary damage upon injury to the spinal cord but suggest that norepinephrine is not a very significant contributor to such damage.
Collapse
|
121
|
Li HJ, Liu DX, Li L, Cha SC, Wilson JB, Webber BB, Huisman TH. Hb Guangzhou-Hangzhou or alpha 2(64)(E13)Asp----Gly beta 2 observed in members of a Chinese family living in Xinjiang. Hemoglobin 1990; 14:441-4. [PMID: 2283298 DOI: 10.3109/03630269009032004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
122
|
Liu DX, Huang L. Small, but not large, unilamellar liposomes composed of dioleoylphosphatidylethanolamine and oleic acid can be stabilized by human plasma. Biochemistry 1989; 28:7700-7. [PMID: 2611208 DOI: 10.1021/bi00445a027] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Small unilamellar liposomes, composed of dioleoylphosphatidylethanolamine (DOPE) and oleic acid (OA), prepared by sonication, were incubated in the presence of human plasma at 37 degrees C. The release of entrapped calcein after 8-h incubation was about 15% in plasma, compared with about 70% in phosphate-buffered saline under the same conditions. In contrast, dioleoylphosphatidylcholine (DOPC)/OA liposomes under the same conditions release about 70% in plasma and only 10% in PBS. Total release of calcein from the DOPE/OA liposomes was observed in a PBS solution containing bovine serum albumin, and the release was completely blocked by preincubation of the liposomes with plasma. These results indicate that the unstable DOPE/OA liposomes are stabilized by incubation with plasma. The stabilization process was very fast, being completed within 1 min. Only relatively small liposomes (d less than or equal to 200 nm) were completely stabilized by plasma; larger liposomes were progressively less stabilizable. SDS-polyacrylamide gel electrophoresis of liposomes which had been incubated with plasma and then washed indicated that several proteins were tightly associated with liposomes. Using liposomes containing [14C]OA, it was found that about 70% of the original OA was extracted after 1-h incubation with human plasma at 37 degrees C. Thin-layer chromatographic analysis of the plasma-treated liposomes showed the presence of the plasma lipids in the liposomes. These results suggest that liposomes composed of DOPE/OA are stabilized by protein and/or lipid components from human plasma and that the composition of the liposomes is altered. The mechanism of stabilization is discussed in terms of the surface pressure of small vesicles with a high degree of curvature.(ABSTRACT TRUNCATED AT 250 WORDS)
Collapse
|
123
|
Liu DX, Zhou F, Huang L. Characterization of plasma-stabilized liposomes composed of dioleoylphosphatidylethanolamine and oleic acid [published errtum appears in Biochem Biophys Res Commun 1989 Sep 29;163(3):1539]. Biochem Biophys Res Commun 1989; 162:326-33. [PMID: 2640561 DOI: 10.1016/0006-291x(89)91999-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
We have previously reported that small unilamellar liposomes (d less than or equal to 200 nm) composed of dioleoylphosphatidylethanolamine and oleic acid can be stabilized by incubating with normal human plasma (Liu and Huang, Biochemistry 1989, in press). The stabilized liposomes were very stable even under relatively harsh conditions such as extreme pH, high salt and trypsin treatment. Fluorescence depolarization of diphenylhexatriene showed that the stabilized liposome had a high microviscosity in the lipid core, which did not decrease even after the majority of proteins were removed by trypsin. These data suggest that plasma proteins inserted into the lipid bilayer are probably responsible for the stabilization activity. After i.v. injection into mouse, stabilized liposomes showed a relatively low affinity to liver and spleen as compared to a conventional liposome composition.
Collapse
|
124
|
Yu MS, Qiu XF, Xue JL, Liu ZD, Tan JZ, Li HJ, Liu DX, Li L, Yu WZ. Identification of partial mutational sites in human mitochondrial DNA in the Chinese and its significance. SCIENCE IN CHINA. SERIES B, CHEMISTRY, LIFE SCIENCES & EARTH SCIENCES 1989; 32:468-77. [PMID: 2571346] [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 simple method for the identification of mutational sites in human mitochondrial DNA (mtDNA) was described. It was based on the human Cambridge sequence as a relative standard sequence and a single base pair substitution in mtDNA as a unique mutational form. The partial mutational sites can be determined using this method which was characterized by combining the restriction mapping with the analysis for the table of human mtDNA potential mutational sites with rapidity and simplicity. In the meanwhile, six mtDNA mutational sites found in Chinese population were identified by means of this method.
Collapse
|
125
|
Liu DX, Yin XJ, Wang HH, Zhou Y. [Antimutagenicity assays of water extracted from the fruits of Cnidium monnieri (L.) cuss]. ZHONG YAO TONG BAO (BEIJING, CHINA : 1981) 1988; 13:40-2, 63. [PMID: 3242940] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
126
|
Yu MS, Qiu XF, Xue JG, Liu ZD, Tan JZ, Li HJ, Liu DX, Li L, Yu WZ, Tang XZ. Mitochondrial DNA polymorphism in Chinese. SCIENTIA SINICA. SERIES B, CHEMICAL, BIOLOGICAL, AGRICULTURAL, MEDICAL & EARTH SCIENCES 1988; 31:860-72. [PMID: 2904697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Human mitochondrial DNA (mtDNA) restriction endonuclease fragment patterns were analyzed using placenta DNA isolated from 273 individuals representing four different nationalities, the Han, the Uygur, the Kazakh and the Hui populations. Thirty-eight fragment patterns (morphs) were observed with the enzyme ApaI, BamHI, EcoRI, HindIII, HinfI, HhaI, HapII, KpnI, Mbol, PstI, PvuII, SacI, ScaL and XhoI. Fourteen new morphs, including some only existing in individual racial and national populations were observed, which indicates that there is a significant difference in the distribution of mtDNA morphs among various national and racial populations. By comparison with the mtDNA sequences in primate species, some mtDNA ancestral morphs were found to be retained in Oriental population today. This result provided indirect evidence that Asia may be one of the human original sources. Genetic distances among four national populations computed and employed in construction of an average linkage tree suggested that the Uygur and the Kazakh populations combined to form a branch at first, then the Han and the Hui came together to form another one, and at last, these two branches converged into a stem. Again, it was found that the internal variation within the Uygur and the Kazakh populations was greater than that within the Han and the Hui populations. These results showed a relationship among the four different national populations in China based on the molecular level.
Collapse
|
127
|
Abstract
A canine limbic system preparation was used as the source of opioid peptide receptors to screen biologic extracts for the presence of opioid receptoractive peptides following their gradient RP-HPLC separation. Eight synthetic dynorphin peptides were studied for their ability to displace the commonly-used ligand 3H-etorphine from the canine limbic system P2 preparation. The peptides studied included the dynorphins 1-7, 1-8, 1-9, 1-10, 1-12, 1-13, 1-17, and dynorphin B. Two different types of opioid peptide molecules were utilized for the determination of the level of non-specific binding. In one study, methionine enkephalin, and in the second study each one of the eight corresponding dynorphins, was used for determination of non-specific binding. The experimental data indicated that 3H-etorphine bound to the canine limbic system P2 receptors, and that those dynorphins displaced effectively the 3H-etorphine from those receptors.
Collapse
|
128
|
Abstract
One patient's lumbar CSF sample out of 54 studied for lower back pain had an atypical metabolic profile of opioid receptoractivity. To test our hypothesis that neuropeptides play a role in human lower back pain, endogenous opioid receptoractivity was compared between a control and that atypical sample. Two lumbar puncture samples were obtained from those two patients, one before and one after clinical evaluation. Total opioid receptoractivity was measured in each sample before HPLC separation, and opioid receptoractivity was measured in each fraction after HPLC separation. The latter data represent a metabolic profile of opioid receptoractivity in the human lumbar CSF. Those data demonstrate that the atypical patient had opioid receptoractivity measurements (total and profile) differing in a qualitative and quantitative sense from the other 53 patients studied. CSF opioid receptoractivity reflects the metabolism of opioid neuropeptidergic systems in the physiology in those patients, and opioid peptides may play a role in lower back pain.
Collapse
|
129
|
Liu DX. [Cell kinetic studies on normal and pericancerous oral mucosa]. ZHONGHUA KOU QIANG YI XUE ZA ZHI = ZHONGHUA KOUQIANG YIXUE ZAZHI = CHINESE JOURNAL OF STOMATOLOGY 1988; 23:1-4, 62. [PMID: 3165315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
|
130
|
Liu DX, Lin ZJ, Li GF, Gao XK. [Studies on the adhesion of Campylobacter jejuni/coli to HeLa cells]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1987; 18:335-8. [PMID: 3449423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
|
131
|
Liu DX, Lin ZJ, Li GF, Gao XK. [Optimal conditions and affecting factors on adhesion of Campylobacter jejuni to HeLa cells]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1987; 18:218-21. [PMID: 3679170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
132
|
Li HJ, Liu DX, Li L, Liu ZG, Lo SL, Zhao J, Han XP, Yu WZ. A note about the incidence and origin of Hb D-Punjab in Xinjiang, People's Republic of China. Hemoglobin 1986; 10:667-71. [PMID: 3557998 DOI: 10.3109/03630268609036571] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
133
|
Li HJ, Liu DX, Li L, Liu ZG, Qing F, Lo SL, Kang QS, Chen J, Chang YQ, Xie DS. Hemoglobinopathies in Xinjiang. Hemoglobin 1986; 10:435-49. [PMID: 3744874 DOI: 10.3109/03630268608996875] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The present report summarizes the results of a search for hemoglobinopathies in 142,171 persons in Xinjiang, the results of structural analyses of abnormal hemoglobins in 134 families, and the incidence and distribution of abnormal hemoglobins and the thalassemias in eight ethnic groups or nationalities.
Collapse
|
134
|
Liu DX. [Mitotic effect of radix codonopsis pilosulae, radix astragali and semen strychni on human lymphocytes]. ZHONG YAO TONG BAO (BEIJING, CHINA : 1981) 1985; 10:40-2. [PMID: 2931202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
|
135
|
Xu YL, Zheng ZT, Liu DX. Cell proliferation kinetics in chronic gastritis and gastric cancer. Chin Med J (Engl) 1984; 97:526-31. [PMID: 6441689] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
|
136
|
Li HJ, Liu DX, Liu ZG, Li P, Li L, Chen J, Hou SZ. A new fast-moving hemoglobin variant, Hb J-Tashikuergan alpha 19(AB1) Ala----Glu. Hemoglobin 1984; 8:391-5. [PMID: 6548207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/05/2023]
|