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Biomedical subjects

M Jiang

Publications and source records attributed to M Jiang.

At least 73 records · Page 4Linked to original sources
PubMed2000

Parietal neurons represent surface orientation from the gradient of binocular disparity.

In order to elucidate the neural mechanisms involved in the perception of the three-dimensional (3D) orientation of a surface, we trained monkeys to discriminate the 3D orientation of a surface from binocular disparity cues using a Go/No-go type delayed-matching-to-sample (DMTS) task and examined the properties of the surface-orientation-selective (SOS) neurons. We recorded 57 SOS neurons from the caudal part of the lateral bank of the intraparietal sulcus (area CIP) of three hemispheres of two Japanese monkeys (Macaca fuscata). We tested 29 of 57 SOS neurons using the square plate of a solid figure stereogram (SFS) and random-dot stereogram (RDS) without perspective cues; almost all of the tested neurons (28/29) showed surface orientation selectivity for the SFS and/or the RDS without perspective cues. Eight of these 28 neurons (28.6%) showed selectivity for both the RDS and SFS, 7 (25.0%) were dominantly selective for the RDS, and 13 (46.4%) were dominantly selective for the SFS. These results suggest that neurons that show surface orientation tuning for the RDS without perspective cues compute surface orientation from the gradient of the binocular disparity given by the random-dot across the surface. On the other hand, neurons that show surface orientation tuning for the SFS without perspective cues may represent surface orientation primarily from the gradient of the binocular disparity along the contours. In conclusion, the SOS neurons in the area CIP are likely to operate higher order processing of disparity signals for surface perception by integrating the input signals from many disparity-sensitive neurons with different disparity tuning.

Animals↗
PubMed2000

[Multiplication of the shrimp baculovirus HHNBV with primary cell cultures from lymphoid organ of Penaeus chinensis].

The hypodermal and hematopoietic necrosis baculovirus HHNBV has been confirmed to be the causative agent for the explosive epidermic disease of farmed shrimp Penaeus chinensis since 1993. The virus was isolated and multiplied successfully in the primary cell cultures from the lymphoid organ of the shrimp. A cell monolayer was formed in three days in the medium MPS and could be maintained for 1-3 months as the medium replaced every 4-5 days. The cytopathic effect occurred in 5 days after inoculation of the tissue extract from the diseased shrimp. The transmission electron microscopy showed many rod-shaped virions of HHNBV in the nuclei of infected cells.

Animals↗
PubMed2000

Mechanism of capacitative Ca2+ entry (CCE): interaction between IP3 receptor and TRP links the internal calcium storage compartment to plasma membrane CCE channels.

Activation of cells by agents that stimulate inositol trisphoshate (IP3) formation causes, via IP3 receptor (IP3R) activation, the release of Ca2+ from internal stores and also the entry of Ca2+ via plasma membrane cation channels, referred to as capacitative Ca2+ entry or CCE channels. Trp proteins have been proposed to be the unitary subunits forming CCE channels; however, there is no definitive proof for this hypothesis. We have now identified amino acid sequences of a Trp and of an IP3R that interact to form stable complexes. These complexes appear to form in vivo, as evidenced by co-immunoprecipitation of Trp with IP3R and by the fact that expression of the respective interacting sequences modulates development of CCE brought about by store depletion. The finding that a Trp-interacting sequence of IP3R interferes with natural CCE leads us to conclude that Trp proteins are, indeed, structural members of CCE channels. We conclude further that direct coupling of IP3R to Trp is a physiological mechanism by which cells trigger CCE in response to signals that stimulate phosphoinositide hydrolysis and IP3 formation. Pros and cons of various CCE activation models are discussed.

Amino Acid Sequence↗
PubMed2000

ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholinopyridin-3-yl)pyrido[2, 3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties: I. In vitro characterization and acute antinociceptive effects in the mouse.

Adenosine (ADO) is an inhibitory neuromodulator that can increase nociceptive thresholds in response to noxious stimulation. Inhibition of the ADO-metabolizing enzyme adenosine kinase (AK) increases extracellular ADO concentrations at sites of tissue trauma and AK inhibitors may have therapeutic potential as analgesic and anti-inflammatory agents. ABT-702 is a novel and potent (IC(50) = 1. 7 nM) non-nucleoside AK inhibitor that has several orders of magnitude selectivity over other sites of ADO interaction (A(1), A(2A), A(3) receptors, ADO transporter, and ADO deaminase). ABT-702 was 1300- to 7700-fold selective for AK compared with a number of other neurotransmitter and peptide receptors, ion channel proteins, neurotransmitter/nucleoside reuptake sites, and enzymes, including cycloxygenases-1 and -2. ABT-702 was equipotent (IC(50) = 1.5 +/- 0. 3 nM) in inhibiting native human AK (placenta), two human recombinant isoforms (AK(long) and AK(short)), and AK from monkey, dog, rat, and mouse brain. Kinetic studies revealed that AK inhibition by ABT-702 was competitive with respect to ADO and noncompetitive with respect to MgATP(2-). AK inhibition by ABT-702 was demonstrated to be reversible after 4 h of dialysis. ABT-702 is orally active and fully efficacious in reducing acute somatic nociception (ED(50) = 8 micromol/kg i.p.; 65 micromol/kg p.o.) in the mouse hot-plate assay. ABT-702 also dose dependently reduced nociception in the phenyl-p-quinone-induced abdominal constriction assay. The antinociceptive effects of ABT-702 in the hot-plate assay were blocked by the nonselective ADO receptor antagonist theophylline, and by the A(1)-selective antagonist cyclopentyltheophylline (10 mg/kg i.p.), but not by a peripherally selective ADO receptor antagonist 8-(p-sulfophenyl)-theophylline (50 mg/kg i.p.), by the A(2A)-selective antagonist 3, 7-dimethyl-1-propargylxanthine (1 mg/kg i.p.) or the opioid antagonist naloxone (5 mg/kg i.p.). Thus, ABT-702 is a novel and potent non-nucleoside AK inhibitor that effectively reduces acute thermal nociception in the mouse by a nonopioid, non-nonsteroidal anti-inflammatory drug, ADO A(1) receptor-mediated mechanism.

Adenosine Kinase↗
PubMed2000

ABT-702 (4-amino-5-(3-bromophenyl)-7-(6-morpholino-pyridin- 3-yl)pyrido[2,3-d]pyrimidine), a novel orally effective adenosine kinase inhibitor with analgesic and anti-inflammatory properties. II. In vivo characterization in the rat.

Adenosine kinase (AK; EC 2.7.1.20) is a key intracellular enzyme regulating intra-and extracellular concentrations of adenosine (ADO), an endogenous neuromodulator, antinociceptive, and anti-inflammatory autocoid. AK inhibition provides a means of potentiating local tissue concentrations of endogenous ADO, and AK inhibitors may have therapeutic potential as analgesic and anti-inflammatory agents. The effects of ABT-702, a novel, potent (IC(50) = 1.7 nM), and selective non-nucleoside AK inhibitor were examined in rat models of nociception and acute inflammation. ABT-702 was orally effective and fully efficacious to suppress nociception in a spectrum of pain models in the rat, including carrageenan-induced thermal hyperalgesia, the formalin test of persistent pain, and models of nerve injury-induced and diabetic neuropathic pain (tactile allodynia after L5/L6 spinal nerve ligation or streptozotocin injection, respectively.) ABT-702 was especially potent at relieving inflammatory thermal hyperalgesia (ED(50) = 5 micromol/kg p.o.). ABT-702 was also effective in the carrageenan-induced paw edema model of acute inflammation (ED(50) = 70 micromol/kg p.o.). The antinociceptive and anti-inflammatory effects of ABT-702 were blocked by selective ADO receptor antagonists, consistent with endogenous ADO accumulation and ADO receptor activation as a mechanism of action. The antinociceptive effects of ABT-702 were not blocked by the opioid antagonist naloxone. In addition, ABT-702 showed less potential to develop tolerance to its antinociceptive effects compared with morphine. ABT-702 had no significant effect on rotorod performance or heart rate (at 30-300 micromol/kg p.o.), mean arterial pressure (at 30-100 micromol/kg p.o.), or exploratory locomotor activity (at </=10 micromol/kg p.o.). Thus, ABT-702 is a novel, non-nucleoside AK inhibitor, with a nonopioid, non-nonsteroidal anti-inflammatory drug mechanism of action, which shows antinociceptive and anti-inflammatory activity in vivo.

Adenosine Kinase↗
PubMed2000

[Selected CD34+ cells transplantation: a primary clinical report].

OBJECTIVE: CD34+ is an immunophenotype of hematopoietic stem cells/progenitors. CD34+ cells selection in vitro may deplete T-cells 4-5 logs and tumor cells 3-4 logs. It will benefit to mismatched related donor allo-transplantation and autologous transplantation of tumor diseases. METHODS: 19 patients aged 29 (5-52) years were treated by allo- (n = 5) or auto-PB CD34+ cells transplantation (n = 14). Grafts from fifteen patients with various disorders (3 lymphomas, 6 multiple myelomas, 2 SLE, 1 Sjogren's syndrome, 2 breast cancer and 1 medulloblastoma) and five haploidentical donors for leukemia patients (1 ALL-CR2, 2 AML-rel, 1 CML-CP and 1 MDS-RAEB) were isolated using magnetic-activated cell sorting (CliniMACS, Milteny Biotech, Germany). RESULTS: After separation, purity of CD34+ cells was > 97%. Depletion of CD34 negative cells was extensive: CD3+ 2.6-4.6 logs, CD4+ > 5 logs, CD8+ 4.6-> 5 logs, and CD19+ 1.2-3.1 logs. 19 patients who received selected CD34+ cells transplantation (CD34+ CT) were followed up for 11(1-20) months. Overall survival(OS) was 13/19 (68.4%) cases. 1/5 patients with haploidentical transplant had disease free survival for 19 months. 12/14(85.7%) auto-CD34+ CT achieved overall survival(OS). CONCLUSION: Selected CD34+ cells transplantation significantly decreases the incidence of > II GVHD and depletes tumor cell contamination. This approach may be useful to haploidentical or unrelated donor transplantation. It also benefits autologous transplant in various tumor disorders.

Adolescent↗
PubMed2000

[Relationship between insulin resistance and pregnancy induced hypertension].

OBJECTIVE: To investigate whether insulin resistance is a cause of pregnancy induced hypertension (PIH). METHODS: All patients who had abnormal 50 g glucose screening test accepted 75 g oral glucose tolerance test (OGTT) and insulin sensitive index (ISI) was calculated. These patients were followed up and divided into two groups (PIH group and normal pregnancy group) at third trimester of pregnancy. The difference of ISI between the PIH group and normal pregnancy group was compared. RESULTS: Fast blood glucose, fast blood insulin and ISI were (4.2 +/- 0.7) mmol/L vs. (3.8 +/- 0.7) mmol/L, (107.8 +/- 48.8) pmol/L vs. (50.4 +/- 40.5) pmol/L, and -3.25 +/- 0.27 vs. -2.58 +/- 0.66 in PIH group and normal group, respectively (P < 0.05). The areas under the curve of insulin were 1,125.6 +/- 331.0 and 1,057.6 +/- 442.2 in PIH group and normal pregnancy group, respectively (P > 0.05). CONCLUSIONS: Insulin resistance during second trimester of pregnancy may be one of the causes of pregnancy induced hypertension.

Adult↗
PubMed2000

[Color duplex ultrasonography, percutaneous transpopliteal venography and photoplethysmography assess venous reflux in the lower extremities].

OBJECTIVES: To assess the scope of photoplethysmography (PPG), color duplex ultrasonography, percutaneous transpopliteal venography for evaluating chronic venous disease. METHODS: Color duplex ultrasonography, percutaneous transpopliteal venography, and PPG and were used in 40 patients their results were compared. RESULTS: Color duplex ultrasonography and percutaneous transpopliteal venography for evaluating venous reflux was not significant (P > 0.05) in the femoral-popliteal venous segment. The accuracy of PPG in evaluating venous reflux was 67% compared with that of color duplex ultrasonography. CONCLUSIONS: PPG as the first test is often used for chronic venous disease. Color duplex ultrasonography can provide sufficient information for treatment of patients the. Percutaneous transpopliteal venography is necessary when noninvasive test can not provide sufficient information.

Femoral Vein↗
PubMed2000

[Operations for laryngeal carcinoma with reservation of laryngeal function].

OBJECTIVE: To study the long term results and functional recovery of partial laryngectomy in the treatment of glottic and supraglottic types of laryngeal carcinoma. METHOD: A series of 70 cases operated on between July 1978 and August 1998 were analysed, of whom 60 were glottic, 10 were supraglottic type laryngeal carcinoma. Among them, 22 cases underwent vocal cord resection, 22 vertical hemilaryngectomy, 17 Majer-Piquet's operation, 7 horizontal hemilaryngectomy, 2 Arslan's operation. RESULT: 1, 3, 5-year survival rates were 98.53%, 87.04% and 78.26% respectively. Decannulation rate was 100%. All patients could finally take food by mouth without inspiration, and could speak as soon as decannulated. Complication and recurrence rates were 15.71% and 13.04% separately. CONCLUSION: Partial laryngectomy is an effective operation on laryngeal carcinoma with reservation of laryngeal function. It not only can totally excise neoplasm and prolong life, but also can better reserve laryngeal function and improve the quality of patient's life.

Adult↗
PubMed2000

[Construction and expression of eukaryotic expression vector pBK-IL-1ra].

OBJECTIVE: Construction of eukaryotic vector with high expression of interleukin-1 receptor antagonist (IL-1ra) for IL-1ra gene delivery. METHODS: (1) Eukaryotic expression vector pBK-IL-1ra was constructed by recombinant DNA technique, and identified by restriction mapping enzymes, PCR, and DNA sequence analysis. (2) Expressions of the IL-1ra mRNA and IL-1ra in vitro and in vivo were detected by in situ hybridization, ELISA, and immunohistochemistry. RESULTS: (1) The correct construction of pBK-IL-1ra was identified by the method above. (2) The higher levels of IL-1ra in the supernate of COS-7 cells (24 h, (P < 0.001; 48 h, P < 0.01) and the over expression of IL-1ra mRNA (P < 0.01) and IL-1ra (P < 0.05) in the synoviocytes have been detected after 48 h of the transfection with pBK-IL-1ra. (3) The over expression of IL-1ra in muscle of the mice was detected by immunohistochemistry after 4 days of pBK-IL-1ra injection (P < 0.01) CONCLUSIONS: We have successfully constructed eukaryotic expression vector pBK-IL-1ra which could highly expressed IL-1ra in vitro and in vivo, and it offers a novel possibility in the research of IL-1ra gene therapy.

Animals↗
PubMed1999

Modulation of Ca(2+) entry by polypeptides of the inositol 1,4, 5-trisphosphate receptor (IP3R) that bind transient receptor potential (TRP): evidence for roles of TRP and IP3R in store depletion-activated Ca(2+) entry.

Homologues of Drosophilia transient receptor potential (TRP) have been proposed to be unitary subunits of plasma membrane ion channels that are activated as a consequence of active or passive depletion of Ca(2+) stores. In agreement with this hypothesis, cells expressing TRPs display novel Ca(2+)-permeable cation channels that can be activated by the inositol 1,4,5-trisphosphate receptor (IP3R) protein. Expression of TRPs alters cells in many ways, including up-regulation of IP3Rs not coded for by TRP genes, and proof that TRP forms channels of these and other cells is still missing. Here, we document physical interaction of TRP and IP3R by coimmunoprecipitation and glutathione S-transferase-pulldown experiments and identify two regions of IP3R, F2q and F2g, that interact with one region of TRP, C7. These interacting regions were expressed in cells with an unmodified complement of TRPs and IP3Rs to study their effect on agonist- as well as store depletion-induced Ca(2+) entry and to test for a role of their respective binding partners in Ca(2+) entry. C7 and an F2q-containing fragment of IP3R decreased both forms of Ca(2+) entry. In contrast, F2g enhanced the two forms of Ca(2+) entry. We conclude that store depletion-activated Ca(2+) entry occurs through channels that have TRPs as one of their normal structural components, and that these channels are directly activated by IP3Rs. IP3Rs, therefore, have the dual role of releasing Ca(2+) from stores and activating Ca(2+) influx in response to either increasing IP3 or decreasing luminal Ca(2+).

Amino Acid Sequence↗
PubMed1999

Lineage-specific modulation of interleukin 4 signaling by interferon regulatory factor 4.

Interleukin (IL)-4 is an immunoregulatory cytokine that exerts distinct biological activities on different cell types. Our studies indicate that interferon regulatory factor (IRF)-4 is both a target and a modulator of the IL-4 signaling cascade. IRF-4 expression is strongly upregulated upon costimulation of B cells with CD40 and IL-4. Furthermore, we find that IRF-4 can interact with signal transducer and activator of transcription (Stat)6 and drive the expression of IL-4-inducible genes. The transactivating ability of IRF-4 is blocked by the repressor factor BCL-6. Since expression of IRF-4 is mostly confined to lymphoid cells, these data provide a potential mechanism by which IL-4-inducible genes can be regulated in a lineage-specific manner.

B-Lymphocytes↗
PubMed1999

Myoglobin-containing carbon-paste enzyme microelectrodes for the biosensing of glucose under oxygen-deficit conditions.

The response of first-generation glucose oxidase (GOx) amperometric glucose biosensors is strongly dependent on the concentration of the oxygen cosubstrate. The incorporation of the natural oxygen binder myoglobin into a GOx-containing carbon-paste matrix is shown to satisfy the oxygen demand of the enzymatic reaction and to provide convenient biosensing of glucose in oxygen-free solutions. Such use of myoglobin-containing mineral oil thus offers an attractive alternative to the use of oxygen-rich fluorocarbon pasting liquids. Further improvements are observed upon doping the fluorocarbon oil with myoglobin. Factors affecting the oxygen independence of the new enzyme microelectrodes, including the myoglobin loading or length of the oxygen reservoir, have been optimized. The myoglobin-doped mineral oil or Kel-F-based carbon-paste enzyme microelectrodes display a highly stable glucose response over prolonged (6-7 h) operations in oxygen-free solutions, indicating no depletion of the internal oxygen supply.

Biosensing Techniques↗
PubMed1999

IFN-alpha activates Stat6 and leads to the formation of Stat2:Stat6 complexes in B cells.

IFN-alpha consists of a family of highly homologous proteins, which exert pleiotropic effects on a wide variety of cell types. The biologic activities of IFN-alpha are mediated by its binding to a multicomponent receptor complex resulting in the activation of the Janus kinase-STAT signaling pathway. In most cell types, activation of Stat1 and Stat2 by IFN-alpha leads to the formation of either STAT homo-/heterodimers or of the IFN-stimulated gene factor 3 complex composed of Stat1, Stat2, and p48, a non-STAT protein. These distinct transcriptional complexes then target two different sets of cis-elements, gamma-activated sites and IFN-stimulated response elements. Here, we report that IFN-alpha can activate complexes containing Stat6, which, until now, has been primarily associated with signaling by two cytokines with biologic overlap, IL-4 and IL-13. Induction of Stat6 complexes by IFN-alpha appears to be cell type specific, given that tyrosine phosphorylation of Stat6 in response to IFN-alpha is predominantly detected in B cells. Activation of Stat6 by IFN-alpha in B cells is accompanied by the formation of novel Stat2:Stat6 complexes, including an IFN-stimulated gene factor 3-like complex containing Stat2, Stat6, and p48. B cell lines resistant to the antiproliferative effects of IFN-alpha display a decrease in the IFN-alpha-mediated activation of Stat6. Activation of Stat6 as well as of Stat2:Stat6 complexes by IFN-alpha in B cells may allow modulation of target genes in a cell type-specific manner.

B-Lymphocytes↗
PubMed1999

Mutations and polymorphisms in gonadotropin genes.

Mutations in gonadotropin genes are extremely rare. Only one case of inactivating human luteinizing hormone (LH) beta mutation exists in the literature, a male with absence of Leydig cells, lack of spontaneous puberty and infertility. A total of four cases of inactivating mutation of the follicle-stimulating hormone beta (FSHbeta) gene (two female and two male) are known. The phenotype of the women was primary amenorrhea and absence of follicular maturation, the men were azoospermic. In addition, a common genetic variant (v) of LH was recently discovered. It is caused by two point mutations in the LH beta-subunit gene, resulting in amino acid alterations: Trp8 --> Arg and Ile15 --> Thr. In addition, the latter change introduces an extra glycosylation signal for oligosaccharide attachment to Asn13. The v-LHbeta allele has a carrier frequency ranging from 0 to > 50% in various populations. The variant LH molecule has increased intrinsic bioactivity in vitro, but decreased circulatory half-life in vivo, and the v-LHbeta promoter is about 50% more active in cell line transfections than that of wild-type (wt) LH. These differences in LH synthesis and action in individuals homo- or heterozygous for the v-LH allele are reflected by altered disposition to pathologies of pituitary-gonadal function, such as delayed puberty, polycystic ovarian syndrome and infertility.

Female↗
PubMed1999

[Study of NAIP gene in spinal muscular atrophy]

OBJECTIVE: Investigating the correlation between the genotype and spinal muscular atrophy(SMA) clinical phenotype. METHODS: Neuronal apoptosis inhibitory protein(NAIP) gene analysis was performed by PCR amplification of exon 5 in 13 unrelated SMA patients with deletions of SMN gene. RESULTS: Two Type-I patients(2/5, 40%) lacked the NAIP exon 5. CONCLUSION: The results suggest a possible correlation between NAIP gene deletion and the disease severity of SMA.

Journal Article↗
PubMed1999

Mouse trp2, the homologue of the human trpc2 pseudogene, encodes mTrp2, a store depletion-activated capacitative Ca2+ entry channel.

Capacitative Ca2+ entry (CCE) is Ca2+ entering after stimulation of inositol 1,4,5-trisphosphate (IP3) formation and initiation of Ca2+ store depletion. One hallmark of CCE is that it can also be triggered merely by store depletion, as occurs after inhibition of internal Ca2+ pumps with thapsigargin. Evidence has accumulated in support of a role of transient receptor potential (Trp) proteins as structural subunits of a class of Ca2+-permeable cation channels activated by agonists that stimulate IP3 formation-very likely through a direct interaction between the IP3 receptor and a Trp subunit of the Ca2+ entry channel. The role of Trp's in Ca2+ entry triggered by store depletion alone is less clear. Only a few of the cloned Trp's appear to enhance this type of Ca2+ entry, and when they do, the effect requires special conditions to be observed, which native CCE does not. Here we report the full-length cDNA of mouse trp2, the homologue of the human trp2 pseudogene. Mouse Trp2 is shown to be readily activated not only after stimulation with an agonist but also by store depletion in the absence of an agonist. In contrast to other Trp proteins, Trp2-mediated Ca2+ entry activated by store depletion is seen under the same conditions that reveal endogenous store depletion-activated Ca2+ entry, i.e., classical CCE. The findings support the general hypothesis that Trp proteins are subunits of store- and receptor-operated Ca2+ channels.

Amino Acid Sequence↗