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H Jin

Publications and source records attributed to H Jin.

At least 127 records · Page 7Linked to original sources
PubMed1998

The glutamate transporter, GLT-1, is expressed in cultured hippocampal neurons.

There are multiple subtypes of Na+-dependent glutamate transporters. Several studies suggest that EAAC1 and EAAT4 are expressed in neurons, while GLT-1 and GLAST expression is thought to be restricted to glia. In the present study, expression of GLT-1 and EAAC1 was examined in cultured rat hippocampal neurons using single cell mRNA amplification and immunocytochemistry with subtype specific antibodies. GLT-1 and EAAC1 mRNAs were observed in all neurons examined. Neuronal phenotype was confirmed in these cells by expression of neurofilament (NF-L) mRNA and absence of glial fibrillary acidic protein (GFAP) mRNA. EAAC1 immunoreactivity was observed in essentially all cells which expressed neuron specific enolase (NSE) and GLT-1 immunoreactivity was detected in the majority (approximately 90%) of NSE-positive cells. Consistent with the glial expression of GLT-1, GLT-1 immunoreactivity was also observed in NSE-negative cells. These studies provide evidence that GLT-1 expression is not intrinsically restricted to glial cells, but can occur in neurons under certain circumstances.

ATP-Binding Cassette Transporters↗
PubMed1998

Selective changes in single cell GABA(A) receptor subunit expression and function in temporal lobe epilepsy.

Temporal lobe epilepsy is the most prevalent seizure disorder in adults. Compromised inhibitory neurotransmitter function in the hippocampus contributes to the hyperexcitability generating this condition, but the underlying molecular mechanisms are unknown. Combining patch-clamp recording and single-cell mRNA amplification (aRNA) techniques in single dentate granule cells, we demonstrate that expression of GABA(A) receptor subunit mRNAs is substantially altered in neurons from epileptic rats. These changes in gene expression precede epilepsy onset by weeks and correlate with profound alterations in receptor function, indicating that aberrant GABA(A) receptor expression and function has an essential role in the process of epileptogenesis.

Animals↗
PubMed1998

Towards functional characterisation of the members of the R2R3-MYB gene family from Arabidopsis thaliana.

Transcription factors containing a conserved DNA-binding domain similar to that of the proto-oncogene c-myb have been identified in nearly all eukaryotes. MYB-related proteins from plants generally contain two related helix-turn-helix motifs, the R2 and R3 repeats. It was estimated that Arabidopsis thaliana contains more than 100 R2R3-MYB genes. The few cases where functional data are available suggest an important role of these genes in the regulation of secondary metabolism, the control of cell shape, disease resistance, and hormone responses. To determine the full regulatory potential of this large family of regulatory genes, a systematic search for the function of all genes of this family was initiated. Sequence data for more than 90 different A. thaliana R2R3-MYB genes have been obtained. Sequence comparison revealed conserved amino acid motifs shared by subgroups of R2R3-MYB genes in addition to the characteristic DNA-binding domain. No significant clustering of the genes was detected, although they are not uniformly distributed throughout the A. thaliana genome.

Amino Acid Sequence↗
PubMed1998

Developmental expression of GABA(A) receptor subunit mRNAs in individual hippocampal neurons in vitro and in vivo.

The GABA(A) receptor is a heterooligomeric protein complex composed of multiple receptor subunits. Developmental changes in the pattern of expression of 11 GABA(A) receptor subunits in individual rat embryonic hippocampal neurons on days 1-21 in culture and acutely dissociated hippocampal neurons from postnatal day (PND) 5 rat pups were investigated using the technique of single-cell mRNA amplification. We demonstrate that multiple GABA(A) receptor subunits are expressed within individual hippocampal neurons, with most cells simultaneously expressing alpha1, alpha2, alpha5, beta1, and gamma2 mRNAs. Further, relative expression of several GABA(A) receptor subunit mRNAs changes significantly in embryonic hippocampal neurons during in vitro development, with the relative abundance (compared with beta-actin) of alpha1, alpha5, and gamma2 mRNAs increasing 2.3-, 2.7-, and 3.8-fold, respectively, from days 1 to 14, and beta1 increasing 5-fold from days 1 to 21. In situ hybridization with antisense digoxigenin-labeled alpha1, beta1, and gamma2 RNA probes demonstrates a similar increase in expression of subunit mRNAs as embryonic hippocampal neurons mature in vitro. Relative abundances of alpha1, beta1, and gamma2 subunit mRNAs in acutely dissociated PND 5 hippocampal neurons are also significantly greater than in embryonic day 17 neurons on day 1 in vitro and exceed the peak values seen in cultured neurons on days 14-21, suggesting that GABA(A) receptor subunit mRNA expression within individual hippocampal neurons follows a similar, if somewhat delayed, developmental pattern in vitro compared with in vivo. These findings suggest that embryonic hippocampal neuronal culture provides a useful model in which to study the developmental regulation of GABA(A) receptor expression and that developmental changes in GABA(A) receptor subunit expression may underlie some of the differences in functional properties of GABA(A) receptors in neonatal and mature hippocampal neurons.

Age Factors↗
PubMed1998

hgpB, a gene encoding a second Haemophilus influenzae hemoglobin- and hemoglobin-haptoglobin-binding protein.

Haemophilus influenzae requires heme for growth and can utilize both hemoglobin and hemoglobin-haptoglobin as heme sources. We previously identified a hemoglobin- and hemoglobin-haptoglobin-binding protein, HgpA, in H. influenzae HI689. Mutation of hgpA did not affect binding or utilization of either heme source. The hgpA mutant exhibited loss of a 120-kDa protein and increased expression of a 115-kDa protein. These data suggested that at least one other gene product is involved in binding of these heme sources by H. influenzae. A 3.2-kbp PCR product derived from HI689 was cloned. The nucleotide sequence indicated a separate, distinct gene with high homology to hgpA, which would encode a 115-kDa protein. Primers were designed for directional cloning of the structural gene in the correct reading frame. Sonicates of induced Escherichia coli harboring the cloned open reading frame bound both hemoglobin and hemoglobin-haptoglobin. An insertion/deletion mutant of H. influenzae at the newly identified locus, designated hgpB, was constructed. The 115-kDa protein was not detected in the mutant after affinity purification using biotinylated hemoglobin. An hgpA hgpB double-mutant strain exhibited a reduced ability to utilize hemoglobin-haptoglobin, although it was unaltered in the ability to utilize hemoglobin. Affinity isolation of hemoglobin-binding proteins from the double mutant resulted in isolation of an approximately 120-kDa protein. Internal peptide sequencing revealed this protein to be a third distinct protein, highly homologous to HgpA and HgpB. In summary a second hemoglobin- and hemoglobin-haptoglobin-binding protein of H. influenzae has been identified and characterized, and the presence of an additional protein of similar function has been revealed.

Amino Acid Sequence↗
PubMed1998

Predictors of relapse in long-term abstinent alcoholics.

OBJECTIVE: The goals of this study were to examine the hazard of relapse during an average 11 years of follow-up in alcoholics who had achieved long-term abstinence and to determine predictors of later relapse. METHOD: Male alcoholics (N = 77) with at least 18 months of stable abstinence at time of entry were followed for 2 to 17 years (mean follow-up = 10.9 years). During follow-up, detailed information regarding relapse/abstinence and interim drinking behavior was recorded. Potential predictors of relapse collected at enrollment included past drinking history, severity of alcohol-related life problems, degree of neurocognitive impairment based on neuropsychological (NP) tests, psychological distress (MMPI) and past medical health. RESULTS: Twenty-four of 77 (31%) long-term abstainers relapsed during the follow-up period. The average annual hazard rate of relapse was 3.8% in the first 5 years of follow-up and 2.6% over the next 6-11 years. Based on Cox proportional hazard regression analyses, the only significant variables to predict relapse were MMPI Scale 4 (Psychopathic Deviate, relative risk = 3.16, 95% CI = 1.19-8.38) and prior history of alcohol-related life difficulty (i.e., citation for driving while intoxicated, relative risk = 2.64, 95% CI = 1.05-6.64) (chi2 = 14.2, 2 df, p < .001). CONCLUSIONS: There is approximately a 3% annual risk of relapse in alcoholics who have been able to achieve long-term abstinence, even after 5 years of abstinence. Alcoholics who resumed drinking had greater indicators of longer standing psychological trait disturbance, reflected in elevated MMPI Scale 4 and history of more alcohol-related social difficulties. Placing the present study in the context of previous research that focused primarily on predictors or relapse in the shorter term, it appears that, whereas mood disturbance predicts short-term outcome, more enduring personality traits predict long-term success in remaining abstinent.

Adult↗
PubMed1998

Study on delay two-phase multiple organ dysfunction syndrome.

OBJECTIVE: To study the injury factors, pathogenic process and clinical features of delay two-phase multiple organ dysfunction syndrome (MODS) in severe burned patients and to replicate a standardized animal model that would accurately imitate the clinical features of MODS. METHODS: Forty-five human patients with burn size larger than 30% total body surface area (TBSA) were analyzed. All of them underwent severe burn shock in early stage and sepsis in late stage. Thirty-two goats were randomly divided into three groups: 1) hemorrhagic shock (group H, n = 6); 2) endotoxemia (group E, n = 6); and 3) hemorrhagic shock plus endotoxemia (group M, n = 20). Hemorrhagic shock was produced according to the method of Wigger (6.7 kPa for an hour, 1 kPa = 7.5 mmHg). Endotoxin (E. coli O111 B4) was given via the portal vein 24 hours after the resuscitation of hemorrhagic shock, in a dose of 30 ng/kg/min for 5 consecutive days. During the observation period of 10 days, all animals were hemodynamically monitored, given standard metabolic support and due cardiac and pulmonary support according to human intensive care. RESULTS: All the patients showed burn shock at 1-3 days and hyperdynamic circulation, hypermetabolism and systemic inflammatory responses over two weeks post-injury. Thirteen cases were found to develop MODS according to the prevailing diagnostic criteria, and 10 of them died with a mortality of 77%. Eighteen animals died in group M with a mortality of 90%, 12 of the 18 developed MODS, with overall incidence of 60%. Most animals in group M showed changes similar to that observed in human cases. The experimentation proved that in the pathogenic process of MODS, there was a two-hit phenomenon in the dvelopment of the syndrome. To prevent the development of MODS, it therefore was imperative to blunt the first hit or the second hit, so that an excessive inflammatory response was alleviated. This postulation has been verified in the treatment of extensive burns. Two patients with burn extent reaching 100% TBSA survived with only mild acute respiratory distress syndrome (ARDS) and renal dysfunction after comprehensive treatment of burn shock, including adequate fluid resuscitation, drugs to remove oxygen free radicals, rapid restoration of pHi, and early extensive excision of burn eschars. CONCLUSION: Both in human patients or animal experimentation, the typical delay two-phase MODS is shown to be produced by two successive insults in the forms of hypovolemic shock and sepsis. This postulation is helpful in formulating the prevention and treatment modality of MODS.

Adult↗
PubMed1998

[Retrospective analysis of 18 cases with agranulocytosis induced by antithyroid drugs].

OBJECTIVE: To analyse the routine WBC count's effect on predicting antithyroid drugs-induced agranulocytosis developing and risk factors of antithyroid drugs-induced agranulocytosis. METHODS: Retrospective analysis of 18 Graves' cases with agranulocytosis induced by antithyroid drugs during 1984-1995. RESULTS AND CONCLUSIONS: Most of antithyroid drugs-induced agranulocytosis happens 2-12 weeks after the administration of antithyroid drug, and are related with the drug's doses. Some agranulocytosis happens abruptly, routine WBC and granulocyte count can not predict some agranulocytosis developing. Fever and throat sore are the intitial symptoms of agranulocytosis, if it happens, the WBC and granulocyte count must be checked immediately. The treatment of granulocyte-macrophage colony stimulating factor is effective, the corticosteroid therapy seems not to be useful for the recovery of granulocyte count.

Adult↗
PubMed1998

[Determination of resibufogenin and cinobufagin in venenum Bufonis by HPLC].

OBJECTIVE: To establish a HPLC method to determine the contents of active constituents in Venenum Bufonis. METHOD: In determining the contents of resibufogenin and cinobufagin in the traditional Chinese medicine Venenum Bufonis, the mobile phase was acetonitrile-0.5% KH2PO4 solution(50:50)(pH adjusted with value phosphoric acid to 3.25 +/- 0.02). RESULT: The constituents thus determined have good linearity and separation. The average recovery of resibufogenin was 100.35%, RSD 1.86%; the average recovery of cinobufagin was 100.38%, RSD 2.09%. CONCLUSION: The method was convenient, rapid, accurate and practicable.

Amphibian Venoms↗
PubMed1998

[Surgical injuries influence on release of endothelin-1 and local blood perfusion of amputated extremities].

OBJECTIVE: To observe influence of amputations and surgical injuries on synthesis and release of endothelium-derived endothelin-1, and local blood perfusion of amputated extremities. METHOD: The plasma endothelin-1 concentrations of 18 patients preoperatively and postoperatively and the endothelin-1 concentrations of femoral artery wall in 80 SD rats were determined using radioimmunoassay technique before and after amputation. Local blood perfusion of amputated extremities in rats were determined using laser Doppler flowmetry. RESULT: The plasma endothelin-1 concentrations in the patients with surgical injuries increased obviously, reached peak value at fourth hour postoperatively, being approximately 3 times of that of the control group. The endothelin-1 concentrations of femoral artery wall in amputated rats also increased, reached peak value at second hour after amputation, being approximately 2 times of that of the control group, and then decreased gradually, at the same time the local blood perfusion decreased, reached its lowest value at second hour after amputation, being only 25 percent of the control value. The endothelin-1 concentration of rat femoral artery wall was negatively relative to local blood perfusion (r = -0.83). CONCLUSION: Injuries enhance synthesis and release of endothelin-1. It is probably one of the main causes of vasospasm after injuries.

Adolescent↗
PubMed1998

[Corneal topographic analysis after excimer laser photorefractive keratectomy].

OBJECTIVE: To analyze the changes in corneal topography after excimer laser photorefractive keratectomy (PRK). METHODS: The topographic changes of 122 eyes (62 patients) and 96 eyes (49 patients) on which PRK was performed were reviewed after 3 and 6 months of follow-up respectively. RESULTS: The central island pattern had a relationship with the loss of best corrected visual acuity of more than one line in early postoperative period. On subsequent follow-up, the central island pattern tended to become to other patterns (semicircular, keyhole and uniform) and the central corneal power decreased, allowing the visual acuity to improve gradually. The simulated K (Sim K) regression index was a useful indication of the changes in the corneal stroma. Sim K was related to the degree of refractive error. The greater the refractive error, the lower the Sim K. CONCLUSION: Corneal topography is a useful tool in the analysis of corneal changes in PRK.

Corneal Topography↗
PubMed1998

[Immunohistochemical studies on wholemounts of the cornea and iris-ciliary body after corneal transplantation].

OBJECTIVE: To study the phenotype of the cells involved in the pathogenesis of allograft rejection after corneal transplantation. METHODS: Wholemounts of the cornea and iris-ciliary body were isolated and prepared from normal rats and those after penetrating corneal transplantation. Immunohistochemical stainings were carried out on these wholemounts using monoclonal antibodies to CD3 (T cell), CD4 [T-helper (Th) cell], CD8 [T-suppressor (Ts) cell], macrophages, dendritic cells, B lymphocytes, major histocompatibility complex (MHC) class II antigen and transforming growth factor-beta (TGF-beta). RESULTS: All the cells mentioned above except B lymphocytes were positive and present in a small number in the peripheral cornea and limbus of normal rats. A massive influx of CD3, CD4, CD8 positive cells, macrophages, dendritic cells, MHC class II and TGF-beta positive cells not only into cornea but also into the iris was observed 7 days after allograft corneal transplantation. Whereas no B cell was found in the allograft. Such a cellular response was not found in the rats in which corneal transplantation with autologous cornea was performed. CONCLUSION: T cells, Th cells, Ts cells, macrophages, dendritic cells, MHC class II positive cells and TGF-beta positive cells are involved in the pathogenesis of corneal allograft transplantation. The involvement of the iris and ciliary body may promote or aggravate the allograft rejection.

Animals↗
PubMed1998

Substantially attenuated hemodynamic responses to Escherichia coli-derived vascular endothelial growth factor given by intravenous infusion compared with bolus injection.

Vascular endothelial growth factor (VEGF) produces beneficial angiogenesis in animal models of coronary and peripheral ischemia. However, intravenous bolus injection of Chinese hamster ovary cell (CHO)-derived VEGF produces adverse effects on hemodynamics. The present study examined pharmacokinetic and hemodynamic responses to Escherichia coli-derived VEGF, which will be used in clinical patients, compared with responses to CHO-derived VEGF, and tested whether intravenous infusion of E. coli-derived VEGF attenuates the hemodynamic responses compared with the responses observed with intravenous bolus injection. Hemodynamic parameters were measured before and after administration of VEGF in conscious, instrumented rats. Intravenous injection of both CHO- and E. coli-derived VEGF produced a similar maximal reduction in arterial pressure, although E. coli-derived VEGF exhibited less of a depressor effect in the initial phase after injection. Either infusion or injection of E. coli-derived VEGF caused hypotension, tachycardia and reduced cardiac output and stroke volume, which were significantly attenuated when given by infusion compared with injection. The maximal hypotensive and tachycardiac responses to infusion were decreased by 50 to 60% compared with those responses observed after injection. Cardiac output was maximally reduced by 34% after injection, but only 18% after infusion. A sustained elevation in systemic vascular resistance observed after injection was avoided after infusion. Thus, the hemodynamic side effects of VEGF administration can be substantially attenuated by controlling the rate of VEGF infusion. The data indicate that infusion, instead of bolus injection, is a more appropriate regimen for VEGF administration.

Animals↗
PubMed1998

An improved, inexpensive method for the large-scale purification of human nerve growth factor.

Human nerve growth factor (hNGF) was purified to near homogeneity on a large scale from human term placenta with an improved and inexpensive method. The purification procedure included tissue homogenization, ultrafiltration and single CM-cellulose column chromatography. The purified hNGF was a 14.4-kDa protein with an isoelectric point of approximately 9.3. The specific activity of the purified hNGF was approximately 38000 units/mg, and the activity was completely inhibited by the monoclonal antibody against recombinant hNGF (rhNGF). Western-blot analysis showed that the purified hNGF could interact with the monoclonal antibody against rhNGF.

China↗
PubMed1997

The role of the cytoplasmic tail region of influenza virus hemagglutinin in formation and growth of fusion pores.

The effect of the cytoplasmic tail of influenza hemagglutinin (HA) (H3 subtype) on fusion kinetics and pore growth was examined An SV40 recombinant virus was used to express wild-type (WT) HA and HA mutants containing changes in the HA cytoplasmic tail. HA and its mutants were expressed in CV-1 cells and the ability of these cells to fuse to either red blood cells (RBCs) or planar bilayer membranes was determined quantitatively. The percentage of cells expressing HA and the levels of expression were the same for WT HA or HA lacking its cytoplasmic tail (CT-), and for a mutant, MAY, in which the three HA C-terminal cysteine residues were replaced to block the addition of palmitate. When RBCs were colabeled with large and small aqueous dyes and fused to CV-1 cells expressing WT HA, transfer of the large dye was significantly slower and extent of transfer was lower than that of the small dye, indicating that pores did not expand quickly to large diameters. An absence of the HA cytoplasmic tail did not alter the time course of spread for either dye. When CV-1 cells expressing WT HA were fused to planar membranes, small pores tended to open and close repetitively ("flicker") before a pore would continue to either grow irreversibly to large conductances or grow to intermediate sizes and then contract. For HA mutants CT- and MAY, flickering was less likely to occur, but these pores did evolve in a manner identical to WT HA postflicker pores. We conclude that palmitate covalently linked to cysteine residues of the HA cytoplasmic tail is required for pore flickering, but that the tail does not play an important role in subsequent pore enlargement.

Animals↗
PubMed1997

A complete YAC contig and cosmid interval map covering the entirety of human Xq21.33 to Xq22.3 from DXS3 to DXS287.

We have produced a physical map that covers the entirety of Xq21.33 to Xq22.3, from DXS3 to DXS287, approximately 15-17 Mb of the proximal long arm of the human X chromosome. This region has already been shown to contain a number of genes involved in genetic disorders, some of which have yet to be cloned. The physical map consists of a contig of 420 yeast artificial chromosome (YAC) clones ordered with respect to 142 DNA markers, approximately one probe every 110 kb. Forty-three YACs from across the contig have been used to isolate 2019 cosmids that have been mapped into 87 intervals, and 667 of these clones are positive for at least 1 single-copy marker. These YACs and cosmids have been used to confirm data from other published contigs that map to the region. The physical map described here constitutes the first step toward a complete transcriptional map of the region.

Chromosome Mapping↗
PubMed1997

Evaluation of the kinetic mechanism of Escherichia coli uridine diphosphate-N-acetylmuramate:L-alanine ligase.

Initial velocity methods were used to probe the kinetic mechanism of Escherichia coli uridine diphosphate-N-acetylmuramate:L-alanine ligase (UNAM:L-Ala ligase). When the activity (in the forward direction) versus substrate concentration data were plotted in double-reciprocal form, all line patterns were intersecting. The best fit of these data was to the equation for an ordered mechanism with the following parameters: k(cat), 1000 +/- 100 min(-1); Kma, 210 +/- 40 microM; Kmb, 84 +/- 20 microM; Kmc, 70 +/- 15 microM; Kia, 180 +/- 50 microM; Kib, 68 +/- 24 microM. Initial velocity line patterns were also determined when the concentration of one substrate was varied at different fixed concentrations of a second substrate while the third substrate was held at a concentration more than 100 times its Km value. Reciprocal plots of data collected with either ATP or L-alanine present at more than 100 times their Km values resulted in intersecting line patterns. Data collected with UNAM present at 100 times its Km value gave a set of parallel lines. These data are consistent with UNAM binding as the second substrate in an ordered mechanism. ADP, uridine diphosphate-N-acetylmuramoyl-L-alanine (UNAMA), and phosphate were tested as product inhibitors versus substrates. None of the products were competitive inhibitors versus L-alanine or UNAM, while the only observed competitive inhibition was ADP versus ATP. These results are consistent with an ordered kinetic mechanism wherein ATP binds first, UNAM binds second, and ADP is the last product released. Rapid quench experiments were performed in the presence of all three substrates or in the presence of ATP and UNAM. The production of acid-labile phosphate as a function of time is characterized by a burst phase followed by a slower linear phase with the rate close to k(cat) in the presence of all three substrates. Only a burst phase was observed for the time course of the reaction in the presence of ATP and UNAM. In both cases, the burst rate was identical. These observations are consistent with L-alanine being the third substrate to bind in a sequential mechanism involving a putative acyl-phosphate intermediate.

Adenosine Triphosphate↗