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Biomedical subjects

Liang Zhou

Publications and source records attributed to Liang Zhou.

At least 37 records · Page 2Linked to original sources
PubMed2006

[C-reactive protein induced human endothelium cells apoptosis is associated with Bcl-2/Bax gene expression changes].

OBJECTIVE: In the present study, we examined the expression changes of Bcl-2/Bax in C-reactive protein (CRP) treated human endothelium cells in vitro. METHODS: The human umbilical vein endothelial cells (HUVEC) were cultured by digest method for 2 - 3 posterities and incubated with human CRP (0, 1, 5, 25 mg/L for 24 hours) and analyzed by flow cytometer for apoptosis ratio. The effects of CRP in various concentrations on Bcl-2/Bax mRNA and protein expression were examined by RT-PCR and Western Blotting. RESULTS: Apoptosis ratio increased, downregulated Bcl-2 (gene promoting cell survival) and upregulated Bax (gene promoting apoptosis) at mRNA and protein levels in proportion to increased CRP concentrations. CONCLUSION: These results demonstrate that Bcl-2/Bax could be regulated by CRP in human HUVECs and might play a causal role in CRP-induced apoptosis.

Apoptosis↗
PubMed2006

[Clinical significance of lymph vessel density marked by lymphatic vessel endothelial hyaluronic acid receptor-1 in laryngeal squamous cell carcinomas].

OBJECTIVE: To study the relationship between density, location, proliferation of lymph vessels and clinicopathological features of laryngeal squamous carcinoma. METHOD: Tumor lymph vessels were quantitated and located in archival specimens of laryngeal carcinoma by LSAB immunostaining for the recently described lymphatic endothelial marker LYVE-1. The Ki67 proliferation marker was used to evaluate the proliferating conditions of LYVE-1(+) vessels with EnVision immunohistochemical methods. RESULT: (1) The density of intratumoral LYVE-1(+) vessels was higher in the cases of neck lymph nodal metastasis group than that of no neck lymph nodal metastasis group (P = 0.000). There was a significant difference of the density of intratumoral LYVE-1(+) vessels in the cases of T1, T2 and T(3-4) group. There was no significant difference of the density of intratumoral LYVE-1(+) vessels between supraglottic group and glottic group, squamous cell histological types I group and types II group (P = 0.125, 0.146, respectively). (2) The density of peritumoral LYVE-1(+) vessels was higher in the cases of neck lymph nodal metastasis group than that of no neck lymph nodal metastasis group. However,there was no statistic significance (P = 0.253). (3) Ki67(+) immunostaining occurs in some of the intratumoral LYVE-1(+) vessels, interestingly, there was no this phenomenon in the peritumoral LYVE-1(+) vessels. CONCLUSION: Intratumoral lymph vessel density marked by LYVE-1 in laryngeal carcinoma was significantly correlated with tumor infiltration and metastasis. Our results provide potent evidence that proliferating lymphatics exists in intratumoral areas of laryngeal carcinoma mainly which maybe contribute to lymph node metastasis in some cases.

Adult↗
PubMed2006

[Management in squamous cell carcinoma of maxillary sinus with orbital invasion].

OBJECTIVE: To explore the orbital management in advanced squamous cell carcinoma of maxillary sinus with orbital invasion. METHOD: Forty-six postoperative cases of advanced squamous cell carcinoma of maxillary sinus with orbital invasion were followed up. Two,three,five-year survival rates and 2-year recurrence rates were analysed in,orbital bone invaded group, periorbit invaded group and orbital content invaded group. RESULT: Two, three,five-year survival rates and 2-year recurrence rates were 65.2%, 55.6%, 46.7% and 38.1% in orbital bone invaded group; 57.1%, 50.0%, 45.5% and 53.8% in periorbit invaded group; 44. 4%, 37. 5%, 37. 5% and 62. 5% in orbital content invaded group, respectively. Survival rates of three groups descended and recurrence rates of three groups ascended but without statistical significance( P >0. 05). CONCLUSION: During the surgery for advanced squamous cell carcinoma of maxillary sinus with orbital invasion without the evidence of optical nerve and eye ball involvement, preservation of orbital contents is considerable even though the orbital bone and periorbit are involved by the tumor.

Adult↗
PubMed2005

Elemene displays anti-cancer ability on laryngeal cancer cells in vitro and in vivo.

PURPOSE: The goal of this study is to investigate the inhibitory effects and mechanism of elemene on the growth of laryngeal cancer cells in vitro and in vivo. METHODS: Laryngeal cancer cells (HEp-2 cells) were grown in elemene, cisplatin, or a combination of the drugs. The cytotoxic, or apoptotic, effects of elemene on the cells were evaluated by a 3-[4,5-dimethylthiazol-2yl]-2,5-diphenyltetrazolium bromide assay, flow cytometry, and a caspase-3 activity assay. A Western blot was used to semi-quantify the protein expression of eukaryotic initiation factors (eIF4E and eIF4G), basic fibroblast growth factor (bFGF), and vascular endothelial growth factor (VEGF); RT-PCR analysis semi-quantified the mRNA transcript expression of bFGF and VEGF. The HEp-2 cells were transplanted subcutaneously to BALB/c nude mice to produce solid tumors. Elemene and cisplatin were administered to the mice either as individual drugs or in combination. The tumors were excised and immunostained to determine the effect each drug had on tumor size, eIF levels, angiogenic factors, and microvessel density (MVD). RESULTS: Elemene inhibited the growth of HEp-2 cells in vitro in a dose- and time-dependent manner with an IC(50) of 346.5 microM (24 h incubation). Increased apoptosis was observed in elemene-administered cells. Elemene is suspected to enhance caspase-3 activity, and thus inhibit protein expression of eIFs (4E, 4G), bFGF, and VEGF. In vivo, the growth of HEp-2 cell-transplanted tumors in nude mice was inhibited by intraperitoneal injection of elemene. Compared with control groups, elemene significantly inhibited the protein expression of eIFs (4E and 4G), bFGF, and VEGF and decreased the MVD. CONCLUSIONS: Elemene inhibits the growth of HEp-2 cells in vitro and in vivo. These data provide useful information for further clinical study on the treatment of LSCC by elemene.

Animals↗
PubMed2005

A c-Rel subdomain responsible for enhanced DNA-binding affinity and selective gene activation.

The NF-kappaB family members p65 (RelA) and c-Rel recognize similar DNA sequences, yet the phenotypes of mutant mice suggest that these proteins regulate distinct sets of genes. Here we demonstrate that 46 unique residues within an 86-residue segment of the Rel homology region (RHR) of c-Rel are responsible for the c-Rel requirement for Il12b gene induction by lipopolysaccharide in bone marrow-derived macrophages. These same residues were responsible for the c-Rel requirement for Il12a induction in dendritic cells, and in both instances, no evidence of c-Rel-specific coactivator interactions was found. Although the residues of c-Rel and p65 that contact specific bases and the DNA backbone within nuclear factor-kappaB (NF-kappaB) recognition sequences are identical, homodimers of c-Rel and of a chimeric p65 protein containing the critical c-Rel residues bound with high affinity to a broader range of NF-kappaB recognition sequences than did wild-type p65 homodimers. These results demonstrate that the unique functions of closely related transcription factor family members can be dictated by differences in the range of DNA sequences recognized at high affinity, despite having similar binding site consensus sequences and DNA contact residues.

Amino Acid Sequence↗
PubMed2005

Conditioned place preference associates with the mRNA expression of diazepam binding inhibitor in brain regions of the addicted rat during withdrawal.

The diazepam binding inhibitor (DBI) modulating the functions of the GABAA receptors is involved in the maladaptation of neural system during using opiate, but its role in opiate dependence is not fully understood. Using conditioned place preference (CPP) rat model and in situ hybridization technique, we examined the correlation between opiate dependence and the mRNA expression of DBI. We found that chronic morphine treatment enabled CPP and increased the DBI mRNA expression in crucial brain regions of addiction. Withdrawal for 3 days caused significant physical signs and further increased the DBI mRNA expression. Both the DBI mRNA and CPP expression remained significantly high but physical signs were at control level in the animals withdrawal for 6 days. Remarkably, the DBI mRNA expressions in the CA1 region of the hippocampus (CA1), ventral tagmental area (VTA), nucleus accumbens (NAc) and amygdala (AMG) were positively correlated to CPP during the periods from withdrawal for 3 days to withdrawal for 6 days. These findings suggest that DBI may play a role in both physical and psychological dependence of opiates.

Animals↗
PubMed2005

Efficient electroluminescence from new lanthanide (Eu3+, Sm3+) complexes.

The syntheses, structures, and electroluminescent properties are described for two new lanthanide complexes Ln(HFNH)3phen [HFNH = 4,4,5,5,6,6,6-heptafluoro-1-(2-naphthyl)hexane-1,3-dione; phen = 1,10-phenanthroline; Ln = Eu3+ (1), Sm3+ (2)]. Both complexes exhibit bright photoluminescence at room temperature (RT) due to the characteristic emission of Eu3+ and Sm3+ ion. Several devices using the two complexes as emitters were fabricated. The performances of these devices are among the best reported for devices using europium complex and samarium complex as emitters. The device based on 1 with the structure ITO/TPD (50 nm)/1:CBP (10%, 40 nm)/BCP (20 nm)/AlQ (30 nm)/LiF (1 nm)/Al (200 nm) exhibits the maximum brightness of 957 cd/m2, current efficiency of 4.14 cd/A, and power efficiency of 2.28 lm/W with a pure red Eu3+ ion emission. Especially, at the high brightness of 200 cd/m2, the device of 1 still has a high current efficiency of 2.15 cd/A. The device of 2 with a three-layer structure of ITO/TPD (50 nm)/2 (50 nm)/BCP (20 nm)/LiF (1 nm)/Al (200 nm) gives the maximum brightness of 42 cd/m2, current efficiency of 0.18 cd/A. By the comparison of the electroluminescent properties of devices based on Eu(TTA3phen (TTA = 2-thenoyltrifluoroacteonate) and 1, we conclude that the polyfluoration on the alkyl group of the ligand and the introduction of the long conjugate naphthyl group into the ligand improve the efficiency of 1-doped devices, especially at high current densities.

Journal Article↗
PubMed2005

Flavone C-glycosides from flowers of Trollius ledebouri.

The ethanol extract of the flowers of Trollius ledebouri yielded four flavone C-glycosides, 2''-O-vanilloylvitexin, 2''-O-feruloylorientin, 2''-O-beta-L-galactopyranosylvitexin, and 2''-O-beta-L-galactopyranosylorientin, along with known compounds, 6''-O-acetylorientin, 2''-O-(4'''-hydroxybenzoyl)vitexin, vitexin, and orientin. Their structures were elucidated by means of UV, IR, MS and NMR spectroscopic analyses.

Flowers↗
PubMed2005

Comparison of nonlinear dynamic methods and perturbation methods for voice analysis.

Nonlinear dynamic methods and perturbation methods are compared in terms of the effects of signal length, sampling rate, and noise. Results of theoretical and experimental studies quantitatively show that measurements representing frequency and amplitude perturbations are not applicable to chaotic signals because of difficulties in pitch tracking and sensitivity to initial state differences. Perturbation analyses are only reliable when applied to nearly periodic voice samples of sufficiently long signal lengths that were obtained at high sampling rates and low noise levels. In contrast, nonlinear dynamic methods, such as correlation dimension, allow the quantification of chaotic time series. Additionally, the correlation dimension method presents a more stable analysis of nearly periodic voice samples for shorter signal lengths, lower sampling rates, and higher noise levels. The correlation dimension method avoids some of the methodological issues associated with perturbation methods, and may potentially improve the ability for real time analysis as well as reduce costs in experimental designs for objectively assessing voice disorders.

Adult↗
PubMed2005

Frequent hypermethylation of RASSF1A and TSLC1, and high viral load of Epstein-Barr Virus DNA in nasopharyngeal carcinoma and matched tumor-adjacent tissues.

We examined the promoter hypermethylation of tumor-suppressor genes RASSF1A and TSLC1, quantitated EBV DNA load in nasopharyngeal carcinoma (NPC) tissues (T tissues), and matched tumor-adjacent tissues outside 0.5 cm (P tissues) and outside 1.0 cm (Z tissues) to evaluate the role of promoter hypermethylation of RASSF1A and TSLC1 as well as viral load in the pathogenesis of NPC. Methylation-specific polymerase chain reaction (PCR) for RASSF1A and TSLC1 and quantitative real-time PCR analysis of EBV DNA were performed on matched T, P, and Z tissues (n = 28) as well as chronic nasopharyngitis tissues (n = 8). Hypermethylated RASSF1A was frequently detected in the T (82%) and P tissues (75%), but less frequently in Z tissues (46%). he average quantities of EBV DNA (copies/microg DNA) in matched T, P, and Z tissues were 673,000, 90,000, and 7000. The differences of promoter hypermethylation of RASSF1A and EBV viral load among T, P, and Z tissues were statistically significant, with more frequent methylation and higher viral load detected when tissues examined were nearer to the NPC tissues. Our results suggest that aberrant hypermethylation of RASSF1A and high EBV load might be important events in NPC pathogenesis, and they may be useful molecular diagnostic markers for this cancer.

Adult↗
PubMed2005

Dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation in humans.

OBJECTIVE: To compare the dose requirements of continuous infusion of rocuronium and atracurium throughout orthotopic liver transplantation (OLT) in humans. METHODS: Twenty male patients undergoing liver transplantation were randomly assigned to two comparable groups of 10 patients each to receive a continuous infusion of rocuronium or atracurium under intravenous balanced anesthesia. The response of adductor pollicis to train-of-four (TOF) stimulation of unlar nerve was monitored. The infusion rates of rocuronium and atracurium were adjusted to maintain T1/Tc ratio of 2%~10%. The total dose of each drug given during each of the three phases of OLT was recorded. RESULTS: Rocuronium requirement, which were (0.468+/-0.167) mg/(kg.h) during the paleohepatic phase, decreased significantly during the anhepatic phase to (0.303+/-0.134) mg/(kg.h) and returned to the initial values at the neohepatic period ((0.429+/-0.130) mg/(kg.h)); whereas atracuruim requirements remained unchanged during orthotopic liver transplantation. CONCLUSIONS: This study showed that the exclusion of the liver from the circulation results in the significantly reduced requirement of rocuronium while the requirement of atracurium was not changed, which suggests that the liver is of major importance in the clearance of rocuronium. A continuous infusion of atracurium with constant rate can provide stable neuromuscular blockade during the three stages of OLT.

Adult↗
PubMed2005

Critical role of Cys168 in noggin protein's biological function.

Previous studies have indicated that noggin exerts its neural inducing effect by binding and antagonizing bone morphogenetic protein 4 (BMP4). In order to further clarify the relationship between the structure and the function of noggin, and elucidate the possible mechanism responsible for noggin-BMP4 interaction, we generated three noggin mutants, C168S, C174S and C197S, by using a site-directed mutagenesis method. Ectopic expression of wild-type (WT) noggin, C174S or C197S, in Xenopus animal caps (ACs) by mRNA injection converted the explants (prospective ectoderm) into neural tissue, as indicated by the neural-like morphology and expression of the neural cell adhesion molecule (NCAM) in the ACs. In contrast, ACs expressing C168S suffered an epidermal fate similar to the control caps. Similarly, among the three mutants, only C168S lost the dorsalizing function. These studies highlight the critical role played by Cys168 in noggin's biological activities. It probably participates in the formation of an intermolecular disulfide bridge.

Amino Acid Substitution↗
PubMed2005

[The effect of high-rate electrical stimulation on excitability of auditory nerve in Guinea pigs].

OBJECTIVE: To assess the effect of high-rate electrical stimulation on excitability of the auditory nerve by recording the change of amplitude of the electrically evoked auditory brainstem responses (EABR). METHOD: After guinea pigs were in the anesthetic state, both bullae were exposed and the round window membranes incised. A standard electrode array was carefully inserted a distance of approximately 4 mm into the scala tympani of the both experimental cochlea and the control cochlea. The most apical electrodes were used as stimulating electrodes. The round window was then sealed with crushed temporal muscle. The electrode arrays were maintained in the same position throughout the experiment. While the stimulus intensities were kept constantly in the normal clinical level (6 dB above EABR threshold), four stimulus rates of 200 (n=14), 400 (n=10), 1000 (n=11), 2000 (n=10) pulses/s(PPS) were each delivered to bipolar electrodes in scala tympani of 45 guinea pigs for 2 h of acute electrical stimulation. Thresholds and wave I amplitudes of EABR were recorded for periods of 3 h following 2 h of acute stimulation. By comparing the pre-stimulus amplitudes of wave I in EABR with the post-stimulus ones(t test), the effect of high-rate electrical stimulation on excitability of the auditory nerve was assessed. RESULT: While the acute stimulus intensity was kept constantly in the normal clinical level (6 dB above EABR threshold), with comparison of pre-stimulus response with post-stimulus response of wave I, the latter increased by 20%, 30%, 9%, 7% at each of the four different stimulus rates of 200, 2000, 400, 1000 PPS. CONCLUSION: Within the 3 h post-stimulus monitoring period after 2 h acute stimulation, no reduction but increase in EABR amplitude was observed using stimulus intensity of 6 dB above EABR threshold at four stimulus rates (200, 400, 1000, 2000 PPS). Electrical stimulation presented at high rates of 1000 to approximately 2000 PPS with clinical intensity (6 dB above EABR threshold) did not result in the reduction of excitability of auditory nerve. These results supported to provide data for the envisaged introduction of a speech-processing strategy based on high stimulus rates.

Animals↗
PubMed2005

[Expression of six gene proteins in laryngeal carcinomas and their significance].

OBJECTIVE: To investigate the expression of p15, p16, Rb, p27,p53 and PCNA gene proteins in different clinical stage, different position and different histological types of laryngeal carcinomas and their significance. METHOD: p15, p16, Rb, p27, p53 and PCNA gene proteins were examined with immunohistochemical SP method in the paraffin-embedded specimens of 65 cases with LSCC and 30 cases of normal or proliferative mucosas of larynx as a contrast. The result was analyzed by chi-square test. RESULT: The expression of the six gene proteins in LSCC and in laryngeal with normal or proliferative mucosas was different, the difference was significant (P < 0.01); the expression of p15 and p27 was significantly related with the position/clinical stage/histological types of LSCC (P < 0.01); the expression of p16 was significantly negative but the PCNA was positive correlated with th histological types of LSCC (P < 0.01). Two of them did not correlate with the position or clinical stage of LSCC (P > 0.05). There was trend of the decreasing Rb expression or increasing p53 expression with increasing clinical stages of LSCC, and the expression of p53 was also positive correlated with the histological types of LSCC. CONCLUSION: p15 and p27 play an important role in the development and progression of LSCC, and can be used as markers for assessment the treatment and prognosis of LSCC. The expression of p16 and PCNA can reflect the proliferation activity in the tumor cells, and is correlated with the development of tumor, but it does not correlate with the progression of tumor. The expression of Rb and p53 were more correlated with the progression of tumor.

Adult↗
PubMed2005

[Inhibition of eIF families expression and angiogenesis for human laryngeal carcinoma by elemene administration].

OBJECTIVE: To investigate the inhibitory effect of elemene on laryngeal carcinoma (Hep-2 cells) xenograft growth in nude mice and its mechanisms, and to explore the relationship between the expression of eukaryotic initiation factor families (eIF4E & eIF4G) and angiogenesis factors (bFGF & VEGF) after the administration of elemene. METHODS: Human laryngeal carcinoma cells from Hep-2 cell strain were transplanted subcutaneously to BALB/c-nu/nu nude mice to produce tumors (42 nude mice were separated into seven groups to be treated by intraperitoneal injection). The tumor volume, tumor weight and tumor inhibition rate were evaluated, the expression of eIF4E, eIF4G, bFGF, VEGF and microvessel density were estimated by paraffin-embedded sections of seven groups' tumor samples analyzed utilizing immunohistochemical streptavidin peroxidase technique. RESULTS: Elemene could inhibit the tumor growth in vivo. A significant suppression of tumor growth was observed when the dosage was increased. The tumor inhibition rates (IR) of elemene 50 mg/kg, 100 mg/kg and 200 mg/kg treated group were 5.2% , 41.7% and 50. 5% respectively. The IR of 100 mg/kg elemene (41.7%) was not significantly different with that of 3 mg/kg cisplatin (44.6%), and the IR of the drug combination (100 mg/kg elemene + 3 mg/kg cisplatin) was 51.2%. Compared with control groups the protein expression of eIF4E, eIF4G, bFGF and VEGF were significantly inhibited by elemene (P < 0.05), and the microvessel density in elemene treated groups decreased (P < 0.05). The tumor inhibition rate of combined elemene 100 mg/kg and cisplatin 3 mg/kg was 51.2%. CONCLUSIONS: Elemene could inhibit the subcutaneous plantation of human laryngeal carcinoma in nude mice and its mechanism may be associated with inhibited expression of eIF families and angiogenesis factors. The combination of elemene and cisplatin could promote the synergistic effect on chemotherapy in the target tumor cells.

Animals↗
PubMed2005

[Role of titanium mesh coated with silk fibroin in rabbit tracheal reconstruction].

OBJECTIVE: To Compare the curative effects between titanium mesh coated with or without silk fibroin and in the treatment of larger trachea circumferential defects. To explore the merits of titanium mesh coated with silk fibroin in promoting mucous healing and decreasing related complications. METHODS: Twenty-five New Zealand white rabbits were chosen , divided randomly as follows: group one: titanium mesh coated with silk fibroin (n = 12), group two: pure titanium mesh without silk fibroin (n = 12); Titanium mesh coated with silk fibroin and those titanium without silk fibroin were embedded in the anterior of 7-12th tracheal rings respectively, in 2 weeks we removed the anterior and lateral wall of 7-12th tracheal rings about 8 mm x 6mm (more than half ring) and used the two different materials to reconstruct tracheal defects. All these rabbits were euthanized in 4, 8 and 12 weeks and tracheal CT scan, tracheal endoscopy, histopathological examination and scanning electron microscopic examinations were performed. All complications such as death, local inflammation, tracheal stenosis were documented. Group three, leave one normal rabbit as controlled study , removed the anterior and lateral wall of 7-12th tracheal rings, and histopathological examination, scanning electron microscopy were performed as controlled study. RESULTS: The CT scan, tracheal endoscopy of those with silk fibroin showed there was no apparent tracheal stenosis. Histopathological examination showed there was no obvious granulation tissue and scar. The mucous membrane and cilia grow normally. The silk fibroin was not entirely absorbed and the remains showed good biocompatibility. The scanning electron microscopy showed that the cilia grew better and more orderly than that of group two, and in 12 weeks, the cilia became normal. In group two, there were 5 rabbits died in succession from suffocation in 4, 5, 7, 17, 60 days after surgery. All rabbits had local or general subcutaneous emphysema. The CT scan, tracheal endoscopy and pathological examination showed that there were apparent granulation tissue, scar hypertrophy, and tracheal stenosis. The mortality of group two (41.7%) for suffocation compare to that of group one (0), the incidence rate of subcutaneous emphysema in group two (100%) to that of group one (25.0%) and the average cross section stenosis area in group two (18.15 +/- 7.85) mm2 to that of group one (3.15 +/- 1.58) mm2, there are significant statistically differences in these postoperative complications (P <0.05) and stenosis degree (P <0.05) between the two groups. In addition, there was one rabbit died of diarrhea in each group except group three. CONCLUSIONS: Silk fibroin and titanium mesh coated with silk fibroin showed good biocompatibility. Titanium mesh coated with silk fibroin used in tracheal reconstruction of rabbits can promote agglutination of mucous membrane and decrease postoperative complications, such as subcutaneous emphysema, tracheostenosis. It may be a prospective biomaterial which can be used in clinical circumferential trachea defect reconstruction.

Animals↗