Biomedical subjects

Ming Zeng

Publications and source records attributed to Ming Zeng.

At least 19 recordsLinked to original sources

PubMed2007

Molecular and cellular defects of skeletal muscle in an animal model of acute quadriplegic myopathy.

Muscle denervation and concomitant high-dose dexamethasone treatment in rodents produces characteristic pathologic features of severe muscle atrophy and selective myosin heavy filament (MyHC) depletion, identical to those seen in acute quadriplegic myopathy (AQM), also known as critical illness myopathy. We tested the hypothesis that defective pre-translational processes contribute to the atrophy and selective MyHC depletion in this model. We examined the effects of combined glucocorticoid-denervation treatment on MyHC and actin mRNA populations; we also studied mRNA expression of the myogenic regulatory factors (MRFs), primary transcription factors for MyHC. Adult female rats were subjected to proximal sciatic denervation followed by high-dose dexamethasone (DD) treatment (5 mg/kg body weight daily) for 7 days. Disease controls included rats treated with denervation alone (DN) or dexamethasone alone (DX). At 1 week the plantaris atrophied by approximately 42% in DD muscles. DD treatment resulted in selective MyHC protein depletion; actin protein concentration was not significantly changed. Despite an increase in total RNA concentration in DN and DD muscles, MyHC and actin mRNA concentrations were significantly decreased in these muscles. MyHC mRNA showed a significantly more extensive depletion relative to actin mRNA in DD muscles. Glucocorticoid treatment did not influence a denervation-induced increase in the mRNA expression of the MRFs. We conclude that a deleterious interaction between glucocorticoid and denervation treatments in skeletal muscle is responsible for pre-translational defects that reduce actin and MyHC mRNA substrates in a disproportionate fashion. The resultant selective MyHC depletion contributes to the severe muscle atrophy.

Actins↗

PubMed2006

Murine CXCR1 is a functional receptor for GCP-2/CXCL6 and interleukin-8/CXCL8.

Functional interleuin-8 (IL-8) receptors (IL-8RA and IL-8RB: CXCR1 and CXCR2, respectively) have been described in human, monkey, dog, rabbit, and guinea pig. Although three IL-8R homologues have been found in rat, only one of these, rat CXCR2, appears to be functional based on responsiveness to ligands. Similarly, CXC chemokines induce biological responses through the murine homolog of CXCR2, but the identification of functional rodent CXCR1 homologues has remained elusive. We have identified and characterized the mouse CXCR1 homologue (mCXCR1). Murine CXCR1 shares 68 and 88% amino acid identity with its human and rat counterparts, respectively. Similar to the tissue distribution pattern of rat CXCR1, we found murine CXCR1 mRNA expression predominantly in lung, stomach, bone marrow, and leukocyte-rich tissues. In contrast to previous reports, we determined that mCXCR1 is a functional receptor. We show predominant engagement of this receptor by mouse GCP-2/CXCL6, human GCP-2, and IL-8/CXCL8 by binding, stimulation of GTPgammaS exchange, and chemotaxis of mCXCR1-transfected cells. Furthermore, murine CXCR1 is not responsive to the human CXCR2 ligands ENA-78/CXCL5, NAP-2/CXCL7, GRO-alpha, -beta, -gamma/CXCL1-3, or rat CINC-1-3. In addition, we show concomitant elevation of mCXCR1 and its proposed major ligand, GCP-2, positively correlated with paw swelling in murine collagen-induced arthritis. This report represents the first description of a functional CXCR1-like receptor in rodents.

Amino Acid Sequence↗

PubMed2006

Targeted deletion of Gpbar1 protects mice from cholesterol gallstone formation.

The Gpbar1 [G-protein-coupled BA (bile acid) receptor 1] is a recently identified cell-surface receptor that can bind and is activated by BAs, but its physiological role is unclear. Using targeted deletion of the Gpbar1 gene in mice, we show that the gene plays a critical role in the maintenance of bile lipid homoeostasis. Mice lacking Gpbar1 expression were viable, developed normally and did not show significant difference in the levels of cholesterol, BAs or any other bile constituents. However, they did not form cholesterol gallstones when fed a cholic acid-containing high-fat diet, and liver-specific gene expression indicated that Gpbar1-deficient mice have altered feedback regulation of BA synthesis. These results suggest that Gpbar1 plays a critical role in the formation of gallstones, possibly via a regulatory mechanism involving the cholesterol 7alpha-hydroxylase pathway.

Animals↗

PubMed2006

A proteome reference map and proteomic analysis of Bifidobacterium longum NCC2705.

A comprehensive proteomic study was carried out to identify and characterize proteins expressed by Bifidobacterium longum NCC2705. A total of 708 spots representing 369 protein entries were identified by MALDI-TOF-MS and/or ESI-MS/MS. Isoelectric point values estimated by gel electrophoresis matched closely with their predicted ones, although some discrepancies exist suggesting that post-translational protein modifications might be common in B. longum. The identified proteins represent 21.4% of the predicted 1727 ORFs in the genome and correspond to 30% of the predicted proteome. Moreover 95 hypothetical proteins were experimentally identified. This is the first compilation of a proteomic reference map for the important probiotic organism B. longum NCC2705. The study aimed to define a number of cellular pathways related to important physiological processes at the proteomic level. Proteomic comparison of glucose- and fructose-grown cells revealed that fructose and glucose are catabolized via the same degradation pathway. Interestingly the sugar-binding protein specific to fructose (BL0033) and Frk showed higher levels of expression in cells grown on fructose than on glucose as determined by semiquantitative RT-PCR. BL0033 time course and concentration experiments showed that the induction time and fructose concentration correlates to increased expression of BL0033. At the same time, an ABC (ATP-binding cassette) transporter ATP-binding protein (BL0034) was slightly up-regulated in cells grown on fructose compared with glucose. All of the above results suggest that the uptake of fructose into the cell may be conducted by a specific transport system in which BL0033 might play an important role.

ATP-Binding Cassette Transporters↗

PubMed2006

[Different approaches of vertebroplasty for management of severe osteoporotic vertebral compression fractures].

OBJECTIVE: To compare the clinical efficacy of 3 approaches of vertebroplasty in the treatment of severe osteoporotic vertebral compression fractures. METHODS: Twenty-five patients with severe osteoporotic vertebral compression fractures were observed, whose average age was 72 years with average disease history of 12 days and average compression of the affected vertebral bodies of 73%. The patients were divided into 3 groups for 3 different fracture types according to Rao's classification of osteoporotic vertebral structure and deformity, namely wedge type (group A, n= 12), biconcave type (group B, n= 7) and crush type (group C, n=6). Unipedicular approach was adopted in group A, far lateral bipedicular approach in group B, and posterior wall vertebroplasty and pedicle screw fixation in group C. The average follow-up time was 1 year. Visual analog scale (VAS), analgesic use and the mobility were measured in the patients preoperatively and 3 days (7 days in group C) and 6 months after the operation, respectively, and the success rates and complications were observed. RESULTS: All the surgical procedures were successful. The average operation time was 35 min in group A, 50 min in group B, and 2 h in group C. The average volume of cement injected into each vertebral body was 2.0 ml. The average blood loss was 30 ml in groups A and B, and 600 ml in group C. The procedure increased mobility and decreased analgesic use. VAS was decreased by a mean of 4.8 in Group A, 6.2 in group B 3 days after the operation and 5.4 in group C 7 days postoperatively, and remained stable till 6 months after the operation (P<0.01). Cement extravasation occurred in 9 cases, cement in the vertebral canal in 2 cases with transient neurological symptoms, and cement extravasation in the intervertebral space and the anterior space of the vertebral bodies took place in 5 and 2 cases, respectively. No neurological complications were observed. CONCLUSION: Different types of severe osteoporotic vertebral compression fractures require management with different approaches of vertebroplasty for adequate filling of the remaining vertebral body, which provides significant pain relief with wider indications.

Aged↗

PubMed2006

[Resonance light scattering of quercetin].

Resonance light scattering(RLS) and absorption spectra of Quercetin were studied in the present paper. In the solution with pH 3.30 to pH 6.50, the RLS singal was very strong and stable, but decreased sharply with a increase in pH when pH > 6.50. In the B-R buffer solution at pH 4.00, the RLS intensity at 497 nm was maximum and proportional to the concentration of quercetin. The linear range is 0.0-3.0 x 10(-4) mol x L(-1) with the detection limit of 3.1 x 10(-7) mol x L(-1). Quantum chemistry calculation showed that this enhancement of RLS occurred because the neutral molecules of quercetin assembled into super-molecular aggregates by 4-4' hydrogen-bond. This result completely accords with the spectral data from experiments.

Antioxidants↗

PubMed2006

[Effects of Apatococcus lobatus parasitization on leaf photosynthesis characteristics of orange (Citrus cv. Olinda)].

With 2-year pot-grown grafted Citrus cv. Olinda as test material, this paper studied the effects of Apatococcus lobatus parasitization on its leaf photosynthesis characteristics. No significant differences were observed between slightly affected and control leaves in their total chlorophyll (Chl a + b) and carotenoid (Car) contents, net photosynthetic rate (P(n)), intercellular CO2 concentration (C(i)), primary maximum photochemical efficiency of PS II (F(v)/F(m)), quantum efficiency of noncyclic electron transport of PS II (phiPS II), and photochemical quenching (qP), but for medium and severely affected leaves, their Chl a + b, Car, P(n), F(v)/F(m), phiPS II and qP decreased by 23.85%, 26.49%, 43.3%, 4.5%, 35.1% and 22.5%, and 37.61%, 44.04%, 64.5%, 8.6%, 63.6% and 40.1%, respectively, while C(i) increased, with significant differences to the control. It could be concluded that the massive parasitization of A. lobatus caused a stress to orange plant, and non-stomatal limitation was the dominating factor of P(n) reduction.

Chlorophyll↗

PubMed2005

[Construction of infectious Japanese encephalitis virus clone based on the cDNA template of the attenuated live vaccine production strain SA14-14-2].

OBJECTIVE: To construct infectious Japanese encephalitis virus (JEV) based on the in vitro-ligated cDNA template of the vaccine strain SA14-14-2, and identify the virus. METHODS: Full-length genomic cDNA of JEV SA14-14-2 strain was ligated and then RNA was transcribed in vitro, the infective virus was obtained by transfecting the RNA into Vero cells and identified. RESULTS: The infective clone of JEV was constructed, the virulence was weaker than the wild virus. CONCLUSION: It was possible to construct infectious clone from the production strain of live attenuated Japanese B encephalitis vaccine.

Animals↗

PubMed2005

[Application of restorative laminoplasty combined with spinous process osteotomy and internal fixation for treatment of degenerative scoliosis].

OBJECTIVE: For treatment of mild degenerative scoliosis (DS) complicated with lumbar canal stenosis (LCS), posterior decompression and the spinal canal enlargement with spinous process osteotomy was performed in combination with fusion and pedicle screw instrument fixation. METHODS: Between 1999 and 2003, 18 male and 26 female elderly patients (with mean age of 63 years, ranging from 47 to 72 years) with DS complicated with LCS were treated with the described surgical procedures, including 25 with single segment lesion and 19 with involvement of 2 segments. A posterior medical incision from one vertebra superior to the target fusion area till the vertebral segment below it was made for spinal exposure. Undermining enlargement of the spinal canal was carried out according to the segments of the stenosis; in some cases the intervertebral disc was resected. Osteotomy was subsequently performed at the base of the spinous process, and the bony defect was covered with the spinous processes. Finally Moe fusion and Isola (17 cases) or Diapason (27 cases) instrument fixation were performed. The therapeutic effects were evaluated according to Oswestry scores and postoperative imaging examinations. RESULTS: The average follow-up period was 3 years, ranging from 1 to 4 years. Thirty-three patients were followed up for one year and 93.9% of them had excellent or good outcome; 27 patients were followed up of 2 years and showed a rate for excellent or good results of 88.9%. Both sagittal and transverse diameters of the lumbar spinal canal were increased obviously as found by CT scanning without spinal canal scar. A rate of 92.6% of the ostetomized spinous processes had bony fusions. Successful covering bone healing was achieved in a mean of 4 months after surgery. Compressive vertebral fractures superior to the fixed segments occurred in 2 cases, including 1 with pedicle screw loosening and the other with pedicle screw breakage. Another patient had delayed wound healing. No recurrence of LCS, spondylolisthesis and decompensation, or pseudarthrosis of the spine was observed in these cases. CONCLUSION: The described surgical procedures for DS can decrease the occurrence of spinal canal scar and promote the healing of the covering bone, and can be a satisfactory treatment for mild DS complicated with LCS in the lumbar sagittal curve.

Adult↗

PubMed2004

Effect of unloading on type I myosin heavy chain gene regulation in rat soleus muscle.

Slow-twitch soleus, a weight-bearing hindlimb muscle, predominantly expresses the type I myosin heavy chain (MHC) isoform. However, under unloading conditions, a transition in MHC expression occurs from slow type I toward the fast-type isoforms. Transcriptional processes are believed to be involved in this adaptation. To test the hypothesis that the downregulation of MHC1 in soleus muscle following unloading is controlled through cis element(s) in the proximal region of the promoter, the MHC1 promoter was injected into soleus muscles of control rats and those subjected to 7 days of hindlimb suspension. Mutation analyses of six putative regulatory elements within the -408-bp region demonstrated that three elements, an A/T-rich, the proximal muscle-type CAT (betae3), and an E-box (-63 bp), play an important role in the basal level of MHC1 gene activity in the control soleus and function as unloading-responsive elements. Gel mobility shift assays revealed a diminished level of complex formation of the betae3 and E-box probes with nuclear extract from hindlimb suspension soleus compared with control soleus. Supershift assays indicated that transcriptional enhancer factor 1 and myogenin factors bind the betae3 and E-box elements, respectively, in the control soleus. Western blots showed that the relative concentrations of the transcriptional enhancer factor 1 and myogenin factors were significantly attenuated in the unloaded soleus compared with the control muscle. We conclude that the downregulation of MHC1 in response to unloading is due, in part, to a significant decrease in the concentration of these transcription factors available for binding the positive regulatory elements.

Adaptation, Physiological↗

PubMed2004

Essential roles of S-nitrosothiols in vascular homeostasis and endotoxic shock.

The current perspective of NO biology is formulated predominantly from studies of NO synthesis. The role of S-nitrosothiol (SNO) formation and turnover in governing NO-related bioactivity remains uncertain. We generated mice with a targeted gene deletion of S-nitrosoglutathione reductase (GSNOR), and show that they exhibit substantial increases in whole-cell S-nitrosylation, tissue damage, and mortality following endotoxic or bacterial challenge. Further, GSNOR(-/-) mice have increased basal levels of SNOs in red blood cells and are hypotensive under anesthesia. Thus, SNOs regulate innate immune and vascular function, and are cleared actively to ameliorate nitrosative stress. Nitrosylation of cysteine thiols is a critical mechanism of NO function in both health and disease.

Alcohol Dehydrogenase↗

PubMed2004

Niemann-Pick C1 Like 1 protein is critical for intestinal cholesterol absorption.

Dietary cholesterol consumption and intestinal cholesterol absorption contribute to plasma cholesterol levels, a risk factor for coronary heart disease. The molecular mechanism of sterol uptake from the lumen of the small intestine is poorly defined. We show that Niemann-Pick C1 Like 1(NPC1L1) protein plays a critical role in the absorption of intestinal cholesterol. NPC1L1 expression is enriched in the small intestine and is in the brush border membrane of enterocytes. Although otherwise phenotypically normal, NPC1L1-deficient mice exhibit a substantial reduction in absorbed cholesterol, which is unaffected by dietary supplementation of bile acids. Ezetimibe, a drug that inhibits cholesterol absorption, had no effect in NPC1L1 knockout mice, suggesting that NPC1L1 resides in an ezetimibe-sensitive pathway responsible for intestinal cholesterol absorption.

Amino Acid Sequence↗

PubMed2004

[Effects of microwave radiation on thymocytes in mice at different power densities].

OBJECTIVE: To investigate the effects of microwave radiation on thymocytes in mice at different power densities. METHODS: The experimental animals were whole-body exposed to microwave radiation with frequency of 2,450 MHz, power density of 1, 5, 15 mW/cm(2) respectively 1 h everyday for 30 days. Then the thymus were taken out after the mice were decapitated. Thymus index, morphological characteristics of thymus were examined. The changes of thymus T-cell subgroups, cell cycle progression in thymocytes and cellular apoptosis were detected with flow cytometry (FCM). RESULTS: The body weights of animals in 5, 15 mW/cm(2) irradiation groups [(28.10 +/- 1.46), (27.50 +/- 2.52) g] were lower than that of the control [(31.95 +/- 2.51) g] (P < 0.05). Pathological observation showed dark red piece of nucleus, some nuclei inclined to one side, slight increase in hassall body. The expressions of CD8 in 5, 15 mW/cm(2) irradiation groups (29.14% +/- 1.68%, 29.18% +/- 0.81%) were higher than that in control group (26.95% +/- 1.27%) (P < 0.05). The percentages of G(2) + M phase thymocytes in both radiation groups (12.24% +/- 1.82%, 11.19% +/- 1.36%) were lower than that in control group (14.58% +/- 0.64%) (P < 0.01). Thymocytic apoptosis rates in the three experimental groups (7.18% +/- 0.99%, 10.06% +/- 1.58%, 9.45% +/- 0.92%) were higher than that in control (4.25% +/- 1.63%) (P < 0.01), but the evident difference between 5 mW/cm(2) and 15 mW/cm(2) was not found (P > 0.05). CONCLUSION: Sub-chronic microwave exposure (2 450 MHz, 5, 15 mW/cm(2)) could induce thymocyte apoptosis, cause pathological changes in thymus, and affect cell cycle progression, thus may inhibit the immune function of the animal.

Animals↗

PubMed2003

Expression of a novel murine type I IFN in the pancreatic islets induces diabetes in mice.

IFN-kappa belongs to a recently identified subclass of type I IFNs. In this study, we report the cloning and preliminary characterization of the murine homologue of IFN-kappa. The gene encodes a 200-aa protein which is 38.5% homologous to human IFN-kappa. Murine IFN-kappa contains four cysteines in analogous positions to those observed in the IFN-alpha and an additional fifth unique cysteine, C174. The murine gene is located on chromosome 4, where other type I murine IFN genes, IFN-alpha and IFN-beta, are clustered. This region is syntenic with human chromosome 9 where the gene encoding IFN-kappa and the type I IFN gene cluster are found. Mouse IFN-kappa is expressed at low levels in peritoneal macrophages and its expression is up-regulated by dsRNA and IFN-gamma. Similar to previously reported transgenic mice carrying type I and type II IFNs, transgenic mice overexpressing murine IFN-kappa in the beta cells of the pancreas develop overt diabetes with hyperglycemia. Histological characterization of pancreatic islets from these transgenic mice showed inflammatory infiltrates with corresponding destruction of beta cells.

Amino Acid Sequence↗

PubMed2003

Protection against group A streptococcus by immunization with J8-diphtheria toxoid: contribution of J8- and diphtheria toxoid-specific antibodies to protection.

A conformationally constrained, minimally conserved peptide from the M protein of group A streptococcus (GAS) has been defined. It consists of 12 amino acids from the C-repeat region within a non-M protein helix-forming sequence and is referred to as "J8." Here, we investigate the immunogenicity of a J8-diphtheria toxoid (DT) conjugate adjuvanted with the human-compatible adjuvants, SBAS2 and alum, and demonstrate that it is capable of inducing opsonic antibodies and can protect outbred mice from virulent challenge. In a range of experiments, protection correlated with the titer of J8-specific antibodies and not with the induction of J8-specific T cells. However, DT-specific antibodies (as well as J8-specific antibodies) were shown to stain the surface of fixed GAS and to be capable of opsonizing live organisms. DT may be an ideal carrier protein for J8 and other GAS peptides for GAS vaccines.

Adjuvants, Immunologic↗

PubMed2003

Identification and characterization of a novel RF-amide peptide ligand for orphan G-protein-coupled receptor SP9155.

Orphan G-protein-coupled receptors are a large class of receptors whose cognate ligands are unknown. SP9155 (also referred to as AQ27 and GPR103) is an orphan G-protein-coupled receptor originally cloned from a human brain cDNA library. SP9155 was found to be predominantly expressed in brain, heart, kidney, retina, and testis. Phylogenetic analysis shows that SP9155 shares high homology with Orexin, NPFF, and cholecystokinin (CCK) receptors, but identification of the endogenous ligand for SP9155 has not been reported. In this study, we have used a novel method to predict peptides from genome data bases. From these predicted peptides, a novel RF-amide peptide, P52 was shown to selectively activate SP9155-transfected cells. We subsequently cloned the precursor gene of the P52 ligand and characterized the activity of other possible peptides encoded by the precursor. This revealed an extended peptide, P518, which exhibited high affinity for SP9155 (EC50 = 7 nm). mRNA expression analysis revealed that the peptide P518 precursor gene is predominantly expressed in various brain regions, coronary arteries, thyroid and parathyroid glands, large intestine, colon, bladder, testes, and prostate. These results indicate the existence of a novel RF-amide neuroendocrine peptide system, and suggest that SP9155 is likely the relevant G-protein-coupled receptor for this peptide.

Algorithms↗

PubMed2003

[Ecological significance of arbuscular mycorrhiza biotechnology in modern agricultural system].

Mycorrhiza plays a key role in nutrient cycling in ecosystem, and protects host plant against environmental stress. Under natural condition, plant's mycorrhizal structure is a normal phenomenon, and arbuscular mycorrhiza (AM) association is the commonest mycorrhizal type. If well mycorrhizal structure can be formed during plant root system developing process, the quantity and quality of plant production will be improved in large. Because of its effects on plant growth and health, it is accepted that AM symbiosis can reduce chemical fertilizer and pesticide inputs. Consequently, this will lead to a reduction in harmful chemical substance impact on environment. The key effects of AM symbiosis can be summarized as follows: (1) improving rooting and plant establishment; (2) improving uptake of low mobile ions; (3) improving nutrient cycling; (4) enhancing plant tolerance to (biotic and abiotic) stress; (5) improving quality of soil structure; and (6) enhancing plant community diversity. In this paper, the ecological characteristic of arbuscular mycorrhiza fungi (AMF), effects of AM on host plant, and ecologic significance of AM biotechnology in agricultural system were reviewed.

Absorption↗

PubMed2003

The hidden dragons.

Most multinational corporations are fascinated with China. Carried away by the number of potential customers and the relatively cheap labor, firms seeking a presence in China have traditionally focused on selling products, setting up manufacturing facilities, or both. But they've ignored an important development: the emergence of Chinese firms as powerful rivals--in China and also in the global market. In this article, Ming Zeng and Peter Williamson describe how Chinese companies like Haier, Legend, and Pearl River Piano have quietly managed to grab market share from older, bigger, and financially stronger rivals in Asia, Europe, and the United States. Global managers tend to offer the usual explanations for why Chinese companies don't pose a threat: They aren't big enough or profitable enough to compete overseas, the managers say, and these primarily state-owned companies are ill-financed and ill-equipped for global competition. As the government's policies about the private ownership of companies changed from forbidding the practice to encouraging it, a new breed of Chinese companies evolved. The authors outline the four types of hybrid Chinese companies that are simultaneously tackling the global market. China's national champions are using their advantages as domestic leaders to build global brands. The dedicated exporters are entering foreign markets on the strength of their economies of scale. The competitive networks have taken on world markets by bringing together small, specialized companies that operate in close proximity. And the technology upstarts are using innovations developed by China's government-owned research institutes to enter emerging sectors such as biotechnology. Zeng and Williamson identify these budding multinationals, analyze their strategies, and evaluate their weaknesses.

Biotechnology↗