Biomedical subjects

Hui Gong

Publications and source records attributed to Hui Gong.

At least 19 recordsLinked to original sources

PubMed2007

Gender difference in hemodynamic responses of prefrontal area to emotional stress by near-infrared spectroscopy.

Presentation of negative pictures was used as emotional stress to assess gender differences in prefrontal area activation in a functional near-infrared spectroscopy (NIRS) study. Compared with neutral condition, the response of oxy-HB for men yielded no significant difference during stress period, but the response induced by stress pictures for women showed significant enhancement. It was indicated that it is crucial to take gender difference into account when negative stimuli are used in functional brain imaging.

Adult↗

PubMed2006

Origin sites of spontaneous cortical spreading depression migrated during focal cerebral ischemia in rats.

Spontaneous cortical spreading depression (CSD) has been found to occur in the penumbral zone of the brain in rats with focal cerebral ischemia, and has been shown to promote expansion of infarction. Electrophysiological recording of CSD has been used for monitoring the penumbral zone, but with an inherently low spatial resolution; consequently, optical intrinsic signal imaging (OISI) was applied to characterize the spontaneous CSD waves following permanent left middle cerebral artery occlusion (MCAO) in rats under alpha-chloralose/urethane anesthesia. Besides the previous report about the regional variation of optical reflectance during spontaneous CSD following MCAO, the origin site of CSD was easily determined using OISI with the benefit of high resolution in the present study. Those origin points (n = 82) were dynamically located in the ipsilateral hemisphere cortex: sometimes outside of the 6 mm x 8 mm observation area in the parietal cortex (n = 19, 23%), and sometimes inside (n = 63, 77%). The data showed a general trend towards the medial cortex (0.40 +/- 0.15 mm per CSD). Because the lateral cortex of the rat brain proved to be infarcted with 2% 2,3,5-triphenyltetrazolium chloride (TTC) staining after 4 h occlusion, the migration of the origin sites implied a growth of the infarcted area. Hence, the determination of origins of spontaneous CSD using OISI would contribute to the continued study of stroke.

Animals↗

PubMed2006

Sleep-active neurons in the preoptic area project to the hypothalamic paraventricular nucleus and perifornical lateral hypothalamus.

The lamina terminalis consists of the organum vasculosum of the lamina terminalis (OVLT), median preoptic nucleus (MnPO) and subfornical organ. The MnPO and ventrolateral preoptic area (vlPOA) are known to contain high densities of neurons that are sleep active. The prevalence of sleep-active neurons in the OVLT and subfornical organ is unknown. The vlPOA and subdivisions of the lamina terminalis project to hypothalamic regions involved in the control of behavioral, electrographic or autonomic arousal, including the lateral hypothalamic area (LHA) and paraventricular nucleus (PVN). The extent to which projection neurons are active during sleep is unknown. We quantified c-Fos protein immunoreactivity (IR) in the lamina terminalis and vlPOA in sleeping and awake rats that received injections of retrograde tracer into either the LHA or PVN. Fos IR was also examined in lamina terminalis neurons following tracer injections into the vlPOA. Significantly more projection neurons from the MnPO, OVLT and vlPOA to the LHA were Fos-immunoreactive in sleeping vs. awake animals. Waking Fos IR was more prevalent in lamina terminalis neurons projecting to the PVN although a subset of MnPO projection neurons in sleeping rats was Fos-immunoreactive. Almost 50% of vlPOA-PVN projection neurons expressed Fos IR during sleep, compared with 3% during waking. Significantly more neurons in the OVLT and MnPO projecting to the vlPOA were Fos-immunoreactive in sleeping vs. awake rats. Inhibition of LHA and PVN neurons arising from OVLT, MnPO and vlPOA neurons may contribute to suppression of behavioral, electroencephalographic and sympathetic nervous system activation during sleep.

Animals↗

PubMed2006

A high-resolution anatomical rat atlas.

This paper reports the availability of a high-resolution atlas of the adult rat. The atlas is composed of 9475 cryosectional images captured in 4600 x 2580 x 24-bit TIFF format, constructed using serial cryosection-milling techniques. Cryosection images were segmented, labelled and reconstructed into three-dimensional (3D) computerized models. These images, 3D models, technical details, relevant software and further information are available at our website, http://vchibp.vicp.net/vch/mice/.

Animals↗

PubMed2006

[Analysis of expression of mitosis checkpoint gene chfr in bone marrow cells of acute leukemia patients].

This study was purposed to investigate the significance of mitosis checkpoint gene chfr expression in acute leukemia (AL). 2 ml of bone marrow were extracted from each of 46 AL patients and 10 normal donors as control and their mononuclear cells were isolated. Then, their chfr expression was detected by using RT-PCR and immunohistochemistry. Normal control blood samples were also analyzed. The results showed that in 15 out of 28 cases of acute non-lymphocytic leukemia and 13 out of 18 cases of acute lymphocytic leukemia expression of chfr gene mRNA and protein significantly decreased as compared with control. The cytogenetic analysis of patients with a decreased Chfr expression revealed abnormal chromosome. In conclusion, Chfr gene is a leukemia-related gene and may play an important role in leukemia pathogenesis.

Bone Marrow Cells↗

PubMed2006

[Regulatory effects of Bmi-1 gene on self-renewal of hematopoietic stem cells--review].

Self-renewal of hematopoietic stem cells is vital for the sustained daily production of blood cells. The Bmi-1 gene is a putative oncogene belonging to the Polycomb group family. Recent studies have shown that the Polycomb-group gene Bmi-1 is indispensable for regulation of self-renewal of normal and leukemic stem cells. The research progress on structure and function of Bmi-1 gene, and its role in self-renewal of hematopoietic stem cells was reviewed.

Cell Differentiation↗

PubMed2006

[Progress in tissue optical imaging].

In this review, we introduce the basic principle and technology progress of tissue optical imaging from both diffuse optical imaging and coherence domain imaging, which include the continuous-wave imaging, time-resolved optical tomography, diffuse photon density waves tomography, ultrasound-modulated optical tomography, optical coherence tomography and laser speckle imaging. Applications of optical imaging in brain activity and tissue function are also discussed.

Brain↗

PubMed2005

Time-varying spreading depression waves in rat cortex revealed by optical intrinsic signal imaging.

This study aimed to investigate the variation of propagation patterns of successive spreading depression (SD) waves induced by K+ in rat cortex. SD was elicited by 1 M KCl solution in the frontal cortex of 18 Sprague-Dawley rats under alpha-chloralose/urethane anesthesia. We applied optical intrinsic signal imaging (OISI) at an isosbestic point of hemoglobin (550 nm) to examine regional cerebral blood volume (CBV) changes in the parieto-occipital cortex. In 6 of the 18 rats, OISI was performed in conjunction with DC potential recording of the cortex. CBV changes appeared as repetitive propagation of wave-like hyperemia at a speed of 3.7+/-0.4 mm/min, which was characterized by a significant negative peak (-14.3+/-3.2%) in the reflectance signal. Among the observed 186 SDs, the first wave always propagated through the entire imaged cortex in every rat, whereas following waves were likely to bypass the medial area of the imaged cortex (partially propagated waves, n=65, 35%). Correspondingly, DC potential shifts showed non-uniform in the medial area, and they seemed closely related to the changes in reflectance. For partially propagated SD waves, the mean time interval to the previous SD wave (217.0+/-24.3 s) was significantly shorter than for fully propagated SD waves (251.2+/-29.0 s). The results suggest that the propagation patterns of a series of SD waves are time-varying in different regions of rat cortex, and the variation is related to the interval between SD waves.

Action Potentials↗

PubMed2005

Direct visualization of the formation of single-molecule conjugated copolymers.

Electrochemical polymerization of two different kinds of thiophene monomers on an iodine-covered gold surface created highly assembled conjugated copolymers with different electronic structures. A scanning tunneling microscope revealed images of several linkage types: diblock, triblock, and multiblock. The single strand of conjugated copolymers exhibited an anomalous swinging motion on the surface. This technique presents the possibility of understanding the copolymerization process from the different monomers on the single-molecular scale and of building single-molecule superlattices on a surface through controlled electropolymerization.

Journal Article↗

PubMed2005

In vitro expression, monoclonal antibody and bioactivity for capsid protein of porcine circovirus type II without nuclear localization signal.

We expressed firstly the Capsid protein gene defecting the nuclear localization signal (NLS) of Porcine circovirus type II (PCV2) in Escherichia coli as a fusion protein with glutathione S-transferase (rGST-dCap protein). The purified rGST-dCap protein and the recombinant NLS-defected Cap protein of PCV2 (rdCap protein) from the purified rGST-dCap protein reacted specifically with swine antiserum to PCV2. Furthermore, the obtained monoclonal antibodies (mAbs) to rdCap protein were shown to bind to PCV2 particles replicated in PK15 cell and capsid protein (Cap protein) of PCV2 expressed in PK15 cells, respectively. mAbs to rdCap protein also revealed the neutralizing ability to PCV2 particles. These results demonstrated that rGST-dCap protein expressed in E. coli was folded correctly or at least partly, and mAbs to rdCap protein possessed the binding epitopes of PCV2 particles whereas mAbs 4C4 and 3F6 to rdCap protein remained the neutralization epitope of PCV2 particle, showing a possibility of neutralizing mAb to rdCap protein as an immnuotherapeutic agent and a potential of rGST-dCap protein as a vaccine antigen or serodiagnostic reagent.

Animals↗

PubMed2005

[Expression of mitosis checkpoint gene CHFR in acute leukemia].

OBJECTIVE: To investigate the expression of mitosis checkpoint gene CHFR in adult patients with acute leukemia (AL) and its clinical significance. METHODS: Four ml of bone marrow was extracted from 65 AL patients, 38 males and 27 females, with the median age of 35, 43 with acute myelocytic leukemia (AML) and 22 with acute lymphocytic leukemia (ALL), 45 de novo patients and 20 recurrent patients, and 8 normal donor of allogeneic bone marrow transplantation as controls. The bone marrow mononuclear cells (BMNC) were isolated. The cell cycle was examined by flow cytometric analysis. The CHFR mRNA level in the BMNC was measured by RT-PCR. The expression of CHFR protein was detected by Western blotting in 32 of the 65 patients and 8 normal persons as control. RESULTS: (1) The levels of CHFR protein and mRNA were correlated with the cumulative percentages of cells in S phases. (2) The expression level of CHFR protein in 40.6% (13/32) of the AL patients and that of the CHFR mRNA in 60.0% (27/45) of the AL patients were both significantly lower than those of the normal controls. (3) The mean expression level of CHFR protein in the recurrent acute lymphoblastic leukemia (ALL) was 0.71, significantly higher than that of the de novo group (0.38, t = 2.54, P = 0.017). (4) The complete remission (CR) rates in the AL patients with high expression levels of CHFR protein and mRNA were 30.2% and 42.4% respectively, significantly lower than those in the AL patients with low expression levels (88.6% and 85.4% respectively, both P < 0.05). Multivariate analysis showed that CHFR was one of the influencing factors of CR rate of AL patients. CONCLUSION: By affecting mitotic checkpoint function, CHFR inactivation plays a key role in tumorigenesis in adult patients with acute leukemia. Moreover, the aberrant expression of CHFR appears to be a good molecular marker to predict the sensitivity of acute leukemia to chemotherapy.

Adolescent↗

PubMed2005

cDNA cloning and functional analysis of goose interleukin-2.

cDNA encoding goose IL-2 (GoIL-2) was cloned from Con A-stimulated goose splenic mononuclear cells (SMC) using oligonucleotide primers based on the conserved sequence of duck (DuIL-2), chicken (ChIL-2) and turkey IL-2s (TuIL-2). The GoIL-2 cDNA is 718nt long, which contains an open reading frame (ORF) of 423 base pairs encoding a protein of 141 aa. The GoIL-2 shows, respectively, 79%, 82-85%, and 91-92% identities with TuIL-2, ChIL-2 and DuIL-2 in cDNA, and also shows, respectively, 63%, 63-64%, and 82-85% identities with TuIL-2, ChIL-2 and DuIL-2 in amino acid sequence. Recombinant GoIL-2 (rGoIL-2) protein expressed in Escherichia coli has an approximate molecular weight of 18kDa. The rGoIL-2 has biological effect on goose and duck as well as chicken lymphocytes in a dose-dependent manner, though the effect on duck and chicken lymphocytes has been found to be relatively weak. In addition, rGoIL-2 also strengthens goose immune responses induced by vaccinating the inactivated oil emulsion vaccine against avian influenza virus. The monoclonal antibodies (mAb) to rGoIL-2 recognized the binding epitopes of nature GoIL-2 protein expressed in vero cells. Antiserum and mAb 5B10 to rGoIL-2 can inhibit the biological activity of rGoIL-2 and endogenous GoIL-2. The results, at the first time, indicated that goose IL-2 reserves species-specialties in the biological functions and can be used as a potential immunoadjuvant for goose vaccination and immunotherapeutic purposes. Finally, the mAbs to rGoIL-2 also provide a useful tool for further immunobiological studies of IL-2 in avian immune systems.

Amino Acid Sequence↗

PubMed2005

Methylation of gene CHFR promoter in acute leukemia cells.

In order to explore whether gene CHFR was inactivated by methylation in leukemia cells, the expression of CHFR was examined before and after treatment with demethylation agent in Molt-4, Jurkat and U937 leukemia cell lines by means of RT-PCR. The methylation of promoter in Molt-4, Jurkat and U937 cells as well as 41 acute leukemia patients was analyzed by MS-PCR. The results showed that methylation of CHFR promoter was inactivated and could be reversed by treatment with a demethylating agent in Molt-4, Jurkat and U937. CHFR promoter methylation was detected in 39% of acute leukemia patients. There was no difference in incidence of CHFR promoter methylation between acute myelocytic leukemia and acute lymphocytic leukemia. In conclusion, CHFR is frequently inactivated in acute leukemia and is a good candidate for the leukemia supper gene. By affecting mitotic checkpoint function, CHFR inactivation likely plays a key role in tumorigenesis in acute leukemia. Moreover, the methylation of gene CHFR appears to be a good index with which to predict the sensitivity of acute leukemia to microtubule inhibitors.

Cell Cycle Proteins↗

PubMed2005

Cloning, in vitro expression and bioactivity of duck interleukin-2.

In this report, the cDNA sequences of Shaoxing (SX) and Muscovy (MV) duck IL-2 were cloned, then recombinant duck IL-2 (rduIL-2) was produced in prokaryotic expression system. In vitro bioactivity of rduIL-2 was determined by lymphocyte proliferation assay and in vivo bioactivity of rduIL-2 was assessed by vaccine immunization. Monoclonal antibodies (mAbs) and polyclonal antibodies (pAbs) specific for rduIL-2 were generated and characterized by ELISA, Western blot and neutralizing assays. The cDNA contains an open reading frame (ORF) of 420-base pairs encoding a protein of 140 amino acids (aa) with a putative signal peptide of 21aa. The His-duIL-2 fusion protein was recognized in Western blot by mAb against chicken IL-2 (chIL-2), but not by mAbs against human IL-2 and mouse IL-2. Recombinant duIL-2 induces in vitro proliferation of Con A-stimulated duck splenocytes in MTT assay and strengthens duck immune responses induced by vaccinating the inactivated oil emulsion vaccine against avian influenza virus. Polyclonal antibodies and mAb 2B3 against rduIL-2 were shown to have effective neutralizing ability by inhibiting the biological activities of both recombinant duIL-2 and endogenous duIL-2. Despite the fact that duck and chicken IL-2s only share identity of 55.0-56.7% in amino acid sequence, duck and chicken IL-2 molecules displayed similar cross-priming activity in in vitro lymphocyte proliferation assays. The results, at the first time, indicated that rduIL-2 has the potential to be used as an immunoadjuvant for enhancing vaccine efficacy and an immunotherapeutic, and the mAbs against rduIL-2 further facilitate basic immunobiological studies of the role of IL-2 in avian immune system.

Amino Acid Sequence↗

PubMed2005

BDNF acutely modulates synaptic transmission and calcium signalling in developing cortical neurons.

Brain-derived neurotrophic factor (BDNF), like other neurotrophins, has long-term effects on neuronal survival and differentiation; furthermore, BDNF has been reported to exert an acute potentiation of synaptic activity and are critically involved in long-term potentiation(LTP). We found that BDNF rapidly induced potentiation of synaptic activity and an increase in the intracellular Ca2+ concentration in cultured cortical neurons. Within minutes of BDNF application to cultured cortical neurons, spontaneous firing rate was dramatically increased as was the frequency and amplitude of excitatory spontaneous postsynaptic currents (EPSCs). Fura-2 recordings showed that BDNF acutely elicited an increase in intracellular calcium concentration ([Ca2+]i). This effect was partially dependent on extracellular Ca2+. In calcium-free perfusion medium a substantial calcium signal remained which disappeared after loading of cortical neurons with 5 microM U-73122. BDNF-induce Ca2+ transients were completely blocked by K252a and partially blocked by Cd2+. The results demonstrate that BDNF can enhance synaptic transmission and induce directly a rise in [Ca2+]i that require two routes: the release of Ca2+ from intracellular calcium stores and influx of extracellular Ca2+ mainly through voltage-dependent Ca2+ channels in cultured cortical neurons.

Animals↗

PubMed2005

[Relationship between respiration exchange ratio and muscle oxygen content measured by near-infrared spectroscopy].

OBJECTIVE: To study the relationship between respiration exchange ratio (RER) and tissue oxygen content in human skeletal muscle. METHOD: Using a portable tissue oximeter based on near-infrared spectroscopy (NIRS), the relative changes of skeletal muscle oxygen content were measured non-invasively and in vivo when healthy volunteers were performing an incremental intensity running protocol. The results were compared with heart rate (HR), VO2, VCO2, and RER. RESULT: In the experiment, the change in skeletal muscle oxygenation content of the volunteers was regular and has a significant close relationship to HR, VO2 and RER (P=0.01). CONCLUSION: It shows that NIRS is a new photonic technology which provides a measurable biomedical parameter for the evaluation of athlete's physique and training effect. It offers reference for monitoring and assessing training effect in vivo, real-time and non-invasively.

Adult↗

PubMed2005

[Antigenic analysis of the recombinant capsid protein of porcine circovirus type 2].

The nuclear localization signal (NLS)-defected capsid protein gene (dCap) of porcine circovirus type 2 (PCV2) was expressed firstly in Escherichia coli as a fusion protein with glutathione S-transferase (rGST-dCap protein). The purified rGST-dCap protein and NLS-defected Cap protein of PCV2 (rdCap protein) from the purified rGST-dCap protein reacted specifically with swine antiserum to PCV2. Furthermore, the obtained monoclonal antibodies (mAbs) to rdCap protein were shown to bind to PCV2 particles replicated in PK15 cell. MAbs to rdCap protein also revealed the neutralizing ability to PCV2 particles. These results demonstrate that rGST-dCap protein expressed in E. coli is folded correctly or at least partly, and all mAbs to rdCap protein possess the binding epitopes of PCV2 particle whereas mAbs 4C4,3F6 and 2G7 to rdCap protein keep the neutralization epitopes of PCV2 particle, showing a potential of rGST-dCap protein as a vaccine antigen or serodiagnostic reagent.

Animals↗

PubMed2004

Accurate multiplex gene synthesis from programmable DNA microchips.

Testing the many hypotheses from genomics and systems biology experiments demands accurate and cost-effective gene and genome synthesis. Here we describe a microchip-based technology for multiplex gene synthesis. Pools of thousands of 'construction' oligonucleotides and tagged complementary 'selection' oligonucleotides are synthesized on photo-programmable microfluidic chips, released, amplified and selected by hybridization to reduce synthesis errors ninefold. A one-step polymerase assembly multiplexing reaction assembles these into multiple genes. This technology enabled us to synthesize all 21 genes that encode the proteins of the Escherichia coli 30S ribosomal subunit, and to optimize their translation efficiency in vitro through alteration of codon bias. This is a significant step towards the synthesis of ribosomes in vitro and should have utility for synthetic biology in general.

Escherichia coli↗