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Biomedical subjects

Jian Luo

Publications and source records attributed to Jian Luo.

36 records · Page 2Linked to original sources
PubMed2005

[Interchange of facial scar flap with upper arm subdermal vascular network skin flap to improve facial appearance].

OBJECTIVE: To evaluate the result of subdermal vascular network skin flap raised from the upper arm to interchange with a facial skin flap carrying a scar resulted from previous burn. METHODS: A transit flap was designed in the anterior medial aspect of the upper arm according to the reverse design method. The subdermal vascular network flap in the upper arm with length-width ratio less than 1.5:1 was raised with the pedicle located outside of the intermuscular septum of musculus biceps/triceps brachialis. The length-width ratio of the facial scar flap should be less than 1.2:1. The two flaps were cross-grafted to repair the facial wound left by raising the scar flap. The pedicles of the flaps were divided on 14 approximately 15 post-operative days (PODs). RESULTS: The two flaps survived with satisfactory appearance in 9 patients with this method. CONCLUSION: Interchange of facial scar flap with subdermal vascular network skin flap from the upper arms could be a new, reliable and effective method for the facial plastic surgery.

Adolescent↗
PubMed2005

In vitro expression and antibody preparation of black carp (Mylopharyngodon piceus) GH.

The cDNA fragment encoding the mature polypeptide of growth hormone (GH) for the black carp (Mylopharyngodon piceus) was PCR amplified and subcloned into pET-28a. The recombinant expression plasmid pET-bcGH was transformed into E.coli BL21(DE3) and fusion polypeptide containing a 6xHis-tag at the N-terminus was expressed after IPTG induction. The fusion protein band of 23 kDa or so showed immunoreactivity to the polyclonal antibody aganist grass carp GH. The recombinant GH for black carp was purified by affinity chromatography and dialysis. Using the fusion protein as an antigen, through the modified immunization method, the polyclonal antiserum to black carp GH was obtained. Immunochemistry results showed that the antiserum could detect the antigen as low as 4 ng. The protein of 21 kDa in black carp pituitary protein extracts and blood serum could be detected by western blot analysis in which polyclonal antiserum to black carp GH was used as the primary antibody. All these results showed that the polyclonal antiserum against black carp GH was not only effective but also highly specific.

Animals↗
PubMed2005

[Cancer and surgical treatment impact the quality of life in patients with head and neck cancer].

OBJECTIVE: To evaluate head and neck cancer and surgical treatment impact the quality of life (QOL). METHODS: In this study, 49 cases of head and neck cancer patients were recruited. Among them, 27 cases were laryngeal cancer, 14 cases were tongue cancer and 8 patients were recurrence of nasal pharyngeal cancer after radical radiotherapy. To demonstrate the cancer in different sites of the head and neck impact QOL of the patients in a different way and cancer impact QOL on the physical well-being, social family well-being, emotional well-being, functional well-being of the patients and quality of life (QOL) changed in different time-point before and after operation, QOL was assessed before surgical treatment and at 1,6 months after operation by means of a performance status scale for head and neck cancer patients (PSS-HN) and the functional assessment of cancer therapy head and neck (FACT-H&N) questionnaire. RESULTS: QOL deteriorated significantly in head and neck cancer patients. Cancer in different sites impact on QOL differently especially in patients with tongue cancer (PSS-HN P = 0.0361, FACT-H&N P = 0.0487). Head and neck cancer impact QOL on the physical well-being, social family well-being, emotional well-being, functional well-being of the patients in FACT-H&N questionnaire especially for emotional well-being domains (F = 2.78, P = 0.0311). The QOL in patients deteriorated by surgical treatment and it could be improved following the time. At the 6 months after operation it nearly reached the same scores that assessed before the operation (PSS-HN t = 2.03, P = 0.1120 FACT-H&N t = 1.03, P = 0.1180). Different surgical approaches and different reconstruction methods have different impact on QOL for patients. Laryngeal cancer patients with partial laryngectomy were 107.20 in FACT-H&N while total laryngectomees were 97. 71 at the 6 months after operation, with statistically difference (t = 3.02, P = 0.0430). Tongue cancer patients without reconstruction were 119. 24 in FACT-H&N while the others with reconstruction were 111.39 at the 6 months after operation (t = 3.00, P = 0.0472). CONCLUSIONS: The QOL in head and neck cancer patients can be assessed by the questionnaire and it can be improved by selecting treatment regimen, surgical approaches and reconstructive methods.

Adult↗
PubMed2004

Acrolein induces oxidative stress in brain mitochondria.

Acrolein, a byproduct of lipid peroxidation, has been shown to inflict significant structural and functional damage to isolated guinea pig spinal cord. Reactive oxygen species (ROS) are thought to mediate such detrimental effects. The current study demonstrates that acrolein can directly stimulate mitochondrial oxidative stress. Specifically, exposure of purified brain mitochondria to acrolein resulted in a dose-dependent increase of ROS and decreases in glutathione content and aconitase activity. This effect was not accompanied by significant intramitochondrial calcium influx or mitochondrial permeability transition, but rather by impaired function of the mitochondrial electron transport system. As well, we detected a significant inhibition of mitochondrial adenine nucleotide translocase (ANT) in the presence of acrolein. This inhibition of ANT likely contributes to acrolein-induced ROS elevation since application of atractyloside, a specific ANT inhibitor, induced significant increase of ROS. We hypothesize that inhibition of ANT may mediate, in part, the acrolein-induced ROS increase in mitochondria.

Acrolein↗
PubMed2004

Inhibition of transcriptional activities of AP-1 and c-Jun by a new zinc finger protein ZNF394.

Zinc finger proteins play important roles in a variety of cellular functions, including cell growth, proliferation, apoptosis, and intracellular signal transduction, and the zinc finger-containing transcription factor has been implicated as a critical regulator of multiple cardiac-expressed genes as well as a regulator of inducible gene expression in response to hypertrophic stimulation. With the aim of identifying the genes involved in human heart development and diseases, we have isolated a novel LER-related zinc finger gene named ZNF394 from human heart cDNA library. ZNF394 gene has a predicted 561-amino acid open reading frame, encoding a 64kDa zinc finger protein. The N-terminus of ZNF394 protein has a leucine-rich region (LER or SCAN domain), followed by a well-conserved krüppel-associated box domain. The C-terminus of the protein contains 7 C2H2 zinc finger motifs in tandem arrays with the highly conserved space region of the H/C-link. ZNF394 gene is mapped to chromosome 7q11.21. Northern blot analysis indicates that a 2.18kb transcript specific for ZNF394 is specifically expressed in the heart, skeletal muscle, and brain in human adult tissues. ZNF394 protein is expressed in cell nucleus. Overexpression of ZNF394 in the cell inhibits the transcriptional activities of c-Jun and AP-1 reporters, suggesting that ZNF394 is a new transcriptional repressor in mitogen-activated protein kinase signaling pathways and may play an important role in cardiac development and/or cardiac function.

Amino Acid Sequence↗
PubMed2004

A novel KRAB zinc-finger protein, ZNF480, expresses in human heart and activates transcriptional activities of AP-1 and SRE.

The zinc-finger motif found in many transcription factors is thought to be important for human heart development and diseases. In this study, we have identified and characterized a novel zinc-finger gene named ZNF480 using degenerate primers from an early human embryo heart cDNA library. ZNF480 contains a KRAB-A box and 12 C2H2 zinc fingers. The cDNA sequence contains an open reading frame of 1551 bp, encoding a putative protein of 516 amino acid residues with a predicted molecular mass of 57 kDa. Northern blot analysis indicates that a 4.7kb transcript specific for ZNF480 is expressed only in embryonic heart. In the adult tissues, the expression of ZNF480 is restricted largely to heart, skeletal muscle, pancreas, and placenta. Overexpression of ZNF480 in cells activates the transcriptional activities of AP-1 and SRE. Therefore, our data suggest that ZNF480 may act as a positive regulator in MAPK-mediated signaling pathways that lead to the activation of AP-1 and SRE.

Amino Acid Sequence↗
PubMed2004

ZNF411, a novel KRAB-containing zinc-finger protein, suppresses MAP kinase signaling pathway.

Cardiac differentiation involves a cascade of coordinated gene expression that regulates cell proliferation and matrix protein formation in a defined temporo-spatial manner. The zinc-finger-containing transcription factor has been implicated as a critical regulator of multiple cardiac-expressed genes as well as a regulator of inducible gene expression in response to hypertrophic stimulation. Mitogen-activated protein kinase (MAPK) signal transduction pathways are among the most widespread mechanisms of eukaryotic cell regulation. The MAPKs function inside the nucleus and target transcription factors that are prebound to DNA. Many transcription factors are probably important MAPK targets. Here, we have cloned a new zinc-finger gene named ZNF411 using degenerate primers from an early embryo heart cDNA library, which mapped to 19p13.11. The ZNF411 gene consists of 2360 nucleotides and encodes a protein of 499 amino acids with an amino-terminal KRAB domain and eleven carboxy-terminal C2H2 zinc-finger units. Northern blot analysis indicates that a 2.4 kb transcript specific for ZNF411 is expressed in heart, skeletal muscle, and placenta at adult stage and is expressed in most of the examined embryonic tissues, especially at a higher level in skeletal muscle, heart, and pancreas. ZNF411 protein distributes evenly in nuclei when overexpressed in the cells. Reporter gene assays show that ZNF411 is a transcriptional repressor and overexpression of ZNF411 in the COS-7 cells inhibits the transcriptional activities of AP-1 and SRE. These results indicate that ZNF411 is a member of the zinc-finger transcription factor family and may be involved in the heart development, and it probably works as a negative regulator in MAPK signaling pathway.

Amino Acid Sequence↗
PubMed2004

Diffusive oxidative stress following acute spinal cord injury in guinea pigs and its inhibition by polyethylene glycol.

Spinal cord injury (SCI) results in rapid and significant oxidative stress. We have previously demonstrated that polyethylene glycol (PEG) repairs neuronal membrane and inhibits lipid peroxidation in an in vitro model of SCI. In this study we tested the effects of PEG on oxidative stress in guinea pigs after SCI. Oxidative stress was assessed by lipid peroxidation, protein carbonyl and glutathione content. A compression injury of spinal cord at T10-11 induced a rapid and diffusive oxidative stress. Administration of PEG immediately after injury resulted in a marked decrease in oxidative stress both at the injury site and in its adjacent segments. These results, along with our previous findings, suggest that an early application of PEG can effectively suppress oxidative stress after SCI in vivo.

Acute Disease↗
PubMed2004

Glycogen synthase kinase 3beta inhibitor Chir025 reduces neuronal death resulting from oxygen-glucose deprivation, glutamate excitotoxicity, and cerebral ischemia.

The serine/threonine kinase, glycogen synthase kinase 3beta (GSK3beta), is abundant in CNS and is neuron specific. GSK3beta plays a pivotal role in the regulation of numerous cellular functions. GSK3beta phosphorylates and thereby regulates many metabolic, signaling, and structural proteins which can influence cell survival. Increased GSK3beta correlates with increased cell death, whereas reduced GSK3beta expression correlates with increased cell survival. We report that the GSK3beta inhibitor Chir025 is neuroprotective in vitro and in vivo. First, Chir025 reduced cultured hippocampal neuron death following glutamate exposure by 15-20% versus vehicle-treated controls. Second, Chir025 significantly reduced cultured cortical neuron death following oxygen-glucose deprivation (OGD) by approximately 50%. Third, Chir025 reduced infarct size following focal cerebral ischemia by nearly 20%. There were no significant differences in the number of TUNEL-positive neurons or in caspase-3 and -9 activities between Chir025- and vehicle-treated rats, although Chir025 elevated cytosolic Bcl-2 expression. These data show that Chir025-mediated inhibition of GSK3beta is neuroprotective and that the mechanism is probably not anti-apoptotic.

Animals↗
PubMed2004

Acrolein induces axolemmal disruption, oxidative stress, and mitochondrial impairment in spinal cord tissue.

Acrolein, a byproduct of oxidative stress and lipid peroxidation, has been implicated in neurodegenerative disorders such as Alzheimer's disease, but not in spinal cord trauma, as a possible key factor in neuronal degeneration. Using an isolated guinea pig spinal cord model, we have found that acrolein, in a dose- and time-dependent manner, inflicts severe membrane disruption, a factor thought to be critical in triggering axonal deterioration and cell death. The concentration threshold of such detrimental effect is shown to be around 1 microM when acrolein was exposed for 4 h. The membrane damage is likely mediated in part by reactive oxygen species and lipid peroxidation, which were elevated in response to acrolein exposure. Antioxidants were able to significantly reduce acrolein-mediated membrane disruption which further supports the role of reactive oxygen species in the loss of membrane integrity. Mitochondrial function was also impaired after acrolein exposure which not only implicates but emphasizes the role of this organelle in reactive oxygen species generation. In summary, our data strongly suggest that at a clinically relevant concentration, acrolein can severely compromise membrane integrity and may further serve as an initiating toxin triggering secondary injury cascades following the initial physical insult to the spinal cord.

Acrolein↗
PubMed2004

Polyethylene glycol improves function and reduces oxidative stress in synaptosomal preparations following spinal cord injury.

Spinal cord injury (SCI) results in rapid and significant oxidative stress. We have previously demonstrated that administration of polyethylene glycol (PEG) inhibits oxidative stress using an in vitro model of SCI. In this study we tested the effects of PEG in vivo, to elucidate the mechanism of PEG-mediated neuroprotection. We show that a compression injury at T10-11 induced diffusive oxidative stress in crude synaptosomal preparations, correlated with synaptosomal dysfunction and increased intrasynaptosomal calcium. Administration of PEG immediately post-injury produced a marked decrease in synaptosomal oxidative stress and calcium, associated with an increase in synaptosomal function. Confocal microscopy using fluorescein conjugated PEG revealed that PEG entered the cells of the injured spinal cord, placing the polymer in a position to directly interact with cellular organelles. PEG attenuates calcium-induced functional compromise of normal spinal cord synaptosomes and mitochondria in vitro. These results indicate that PEG may exert its neuroprotective effect through direct interaction with mitochondria, besides its known ability to rescue neurons and their axons by repairing the plasma membranes. We submit that PEG is likely to interfere with the cascade of secondary injury by several mechanisms of action that in concert reduce oxidative stress.

Animals↗
PubMed2004

[Purification of eutrophic wastewater by Cyperus alternifolius, Coleus blumei and Jasminum sambac planted in a floating phytoremediation system].

In a greenhouse study, Cyperus alternifolius, Coleus blumei and Jasminum sambac were cultured in a floating phytoremediation system with plantation cups inserted into a polyfoam plate that floated in the upper part of a tank filled with 100 L domestic wastewater. The contents of chemical oxygen demand (CODCr), total P (T-P), total N (T-N), soluble P(S-P), ammonia-nitrogen (NH4+ -N) and nitrate-nitrogen (NO3- -N) in the domestic wastewater were tested during the growth of these three plants. The results showed that Cyperus alternifolius and Coleus blumei could grow well in the floating phytoremediation system, their dry weight being 285.8% and 371.4% of the initial weight of planting, respectively, but Jasminum sambac could not grow well, being 125.0% of the initial weight of planting. The removal rate of TN by these 3 plants was 68.0%, 62.0% and 45.0%, and that of NO3- -N, CODCr and TP was 98.0%, 80.0% and 92.0%, 78.0%, 66.0% and 55.0%, and 90.6%, 90.5% and 88.0% respectively. Cyperus alternifolius and Coleus blumei had good effects on the removal of pollutants in the floating phytoremediation system.

Biodegradation, Environmental↗
PubMed2002

Detection of reactive oxygen species by flow cytometry after spinal cord injury.

The monitoring of reactive oxygen species (ROS) levels in injured nervous tissue is critical for both studying the mechanism of secondary damage and evaluating the effectiveness of antioxidants. Flow cytometry is an excellent method to detect ROS in cultured cells and naturally suspended individual cells. However, its use in nervous tissue is limited due to the difficulties in obtaining single cells in suspension. We have developed a new method which minimizes the error during conventional dissociation. Specifically, we introduced a fixation step (with formaldehyde) between the dye loading and dissociation. As a result, the post-injury ROS signals detected by flow cytometry increase significantly when using hydroethidine as superoxide indicator. The injury-induced elevation of ROS obtained from this new method was also in better agreement with the two other standard ROS detection methods, fluorescence microscopy and lipid peroxidation assay. Furthermore, more pronounced decrease of ROS was found in this improved method in response to treatment with a superoxide scavenger, manganese(III)tetrakis(4-benzoic acid)porphyrin. Based on these observations, we suggest that the data obtained from the cells by this new method are more accurate than those from the classic cell dissociation method that dissociates cells directly from fresh tissues.

Animals↗
PubMed2002

Extracellular domain of TGFbeta type III receptor inhibits angiogenesis and tumor growth in human cancer cells.

TGFbeta overexpression in human cancer cells has been shown to promote tumor progression. In the present study, we sought to determine whether sequestration of endogenous TGFbeta by the expression of a soluble TGFbeta type III receptor (sRIII), can reduce malignancy in human carcinoma cells and whether the tumor-suppressive activity of sRIII is associated with the inhibition of angiogenesis. Ectopic expression of sRIII significantly inhibited the growth of tumors formed by human colon carcinoma HCT116 and breast carcinoma MDA-MB-435 cells in nude mice. It also reduced the metastatic potential of the MDA-MB-435 cells. Thus, endogenous TGFbeta appears to be necessary for the progression of these two carcinomas. Furthermore, when the tumor cells were mixed with Matrigel and embedded subcutaneously in nude mice, the blood volume in Matrigel plugs containing sRIII-expressing cells as indicated by hemoglobin levels was significantly lower than that in Matrigel plugs containing the respective control cells. Blood vessel counts in paraffin sections of the Matrigel plugs containing sRIII-expressing cells were also significantly lower than those in paraffin sections of the Matrigel plugs containing control cells. Treatment of human endothelial cells with a recombinant sRIII significantly inhibited their ability to form a capillary web structure on Matrigel. These results for the first time indicate that the sRIII-induced tumor suppression appears to be in part due to the inhibition of angiogenesis.

Angiogenesis Inhibitors↗
PubMed2002

Polyethylene glycol immediately repairs neuronal membranes and inhibits free radical production after acute spinal cord injury.

Membrane disruption and the production of reactive oxygen species (ROS) are important factors causing immediate functional loss, progressive degeneration, and death in neurons and their processes after traumatic spinal cord injury. Using an in vitro guinea pig spinal cord injury model, we have shown that polyethylene glycol (PEG), a hydrophilic polymer, can significantly accelerate and enhance the membrane resealing process to restore membrane integrity following controlled compression. As a result of PEG treatment, injury-induced ROS elevation and lipid peroxidation (LPO) levels were significantly suppressed. We further show that PEG is not an effective free radical scavenger nor does it have the ability to suppress xanthine oxidase, a key enzyme in generating superoxide. These observations suggest that it is the PEG-mediated membrane repair that leads to ROS and LPO inhibition. Furthermore, our data also imply an important causal effect of membrane disruption in generating ROS in spinal cord injury, suggesting membrane repair to be an effective target in reducing ROS genesis.

Acute Disease↗
PubMed1999

Double-Aging Method for Preparation of Stabilized Na-Buserite and Transformations to Todorokites Incorporated with Various Metals.

A double-aging method has been developed to prepare and stabilize Na-buserite. In the first step, Na-buserite is synthesized by aging a MnO(x)() gel, which is produced from the oxidation of Mn(OH)(2) in NaOH solutions by KMnO(4) in the presence of Mg(2+). Stabilization of Na-buserite is done by further aging the as-synthesized buserite in distilled deionized water. Physical and chemical changes during the second aging (stabilization) have been investigated by using X-ray diffraction (XRD), infrared (IR), scanning electronic microscopy and energy-dispersive X-ray studies (SEM/EDX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), cyclic voltammetry (CV), and temperature-programmed desorption combined with mass spectrometer (TPD-MS). The amount and type of metals incorporated into buserite and todorokite are greatly increased by the second aging treatment (including many lanthanides, whose incorporation has not been reported before). The metal species introduced in the layers considerably change the interlayer distances and, accordingly, the cell parameters. A criterion is obtained for the transformation of todorokite-type tunnel MnO(x)() materials from buserite-type layered MnO(x)() by hydrothermal treatment: only buserites which are stable at elevated temperatures in aqueous systems can convert to a todorokite structure; unstable buserites form a structure whose main d spacings are at 3.56 and 7.1 Å. Interconversions among several layered MnO(x)() are also discussed.

Journal Article↗
PubMedDate not supplied

A nested-cell approach for in situ remediation.

We characterize the hydraulics of an extraction-injection well pair in arbitrarily oriented regional flow by the recirculation ratio, area, and average residence time in the recirculation zone. Erratic regional flow conditions may compromise the performance of the reactor between a single well pair. We propose an alternative four-well system: two downgradient extraction and two upgradient injection wells creating an inner cell nested within an outer cell. The outer cell protects the inner cell from the influence of regional flow. Compared to a two-well system, the proposed four-well system has several advantages: (1) the recirculation ratio within the nested inner cell is less sensitive to the regional flow direction; (2) a transitional recirculation zone between the inner and outer cells can capture flow leakage from the inner cell, minimizing the release of untreated contaminants; and (3) the size of the recirculation zone and residence times can be better controlled within the inner cell by changing the pumping rates. The system is applied at the Field Research Center in Oak Ridge, Tennessee, where experiments on microbial in situ reduction of uranium (VI) are under way.

Bacteria↗