Biomedical subjects

Yang Cao

Publications and source records attributed to Yang Cao.

At least 37 records · Page 2Linked to original sources

PubMed2006

[Heteroplasmy in human mtDNA control region].

OBJECTIVE: To observe the length heteroplasmy and point heteroplasmy in human mtDNA control region. METHODS: The peripheral blood, buccal cell, and single hair shaft from 50 individuals and 16 family members, related in their maternallineage were analyzed by direct sequencing, and clones from 20 individuals whose mtDNA sequences have a T-C transition at 16189 nt were sequenced. RESULTS: No point heteroplasmy were observed in peripheral blood, buccal cell, single hair shaft from the same individual, neither in maternally related individuals. Length heteroplasmy was observed in those individuals with a homopolymeric tract and the different clones from the same individual has different proportions of length variants, but the hair shafts from the same individual were very similar to the measurements made from blood DNA. No length heteroplasmy was observed between different tissues from the same individual. CONCLUSION: mtDNA sequences have a characteristic of high consistency and genetic stability, mtDNA sequencing is a suitable tool for forensic applications such as individual identification.

Base Sequence↗

PubMed2006

[Effects of Robinia pseudoacacia roots on deep soil moisture status].

The study on the root distribution characters of Robinia pseudoacacia and soil moisture status in the Loess Plateau showed that on shady slope, there was no obvious difference in the horizontal distribution of R. pseudoacacia fine roots within 2.0 m from the stem, and the maximal distribution depth of the roots could reach 2.0 m. In sunny slope, the vertical distribution of the roots within 0.5 m from the stem could also reach that depth. The root amount in shady slope was larger than that in sunny slope, and the affected depth of R. pseudoacacia roots on soil moisture status reached 3.3 m in shady slope, while 2.7 m in sunny slope.

Ecosystem↗

PubMed2006

[Differential regulation of P2X3 mRNA expression in the rat trigeminal ganglion after experimental tooth movement].

OBJECTIVE: To investigate the regulation of P2X3 mRNA expression in the trigeminal ganglion sensory neurons after the nociceptive stimulation by orthodontic tooth movement force. METHODS: Male Sprague-Dawley rats weighing 200-250 g were used. The mimic tooth movement appliance was used in the rats of the experiment group. The rats were sacrificed after 4 h, 12 h, 1 d, 2 d, 3 d, 5 d and 7 d after experiment. The expression of P2X3 mRNA was detected by in situ hybridization with an oligonucleotide probe. RESULTS: After force was given to the teeth of rats, the number of P2X3 mRNA positive neurons increased on the first day and reached the peak on the third day; then, the level of P2X3 mRNA expression began to decrease, and after seven days, it returned to the level of the control group. CONCLUSION: The results suggest that the P2X3 mRNA expression is transiently upregulated and anterogradely transported in trigeminal primary sensory neurons after orthodontic tooth movement and that P2X3 receptor may play a role in the pathomechanism of nociception in primary sensory neurons during orthodontic treatment.

Animals↗

PubMed2006

[Effects of jianwei yuyang granule on inflammatory reaction and NF-kappaB expression in rat gastric mucosa of ulcer healing and recurrence].

OBJECTIVE: To observe the effects of Jianwei Yuyang granule (JWYY) on inflammatory reaction and NF-kappaB expression in rat gastric mucosa of ulcer healing and recurrence. METHOD: Gastric ulcer was induced in rat by acetic acid according Okeba's method with some modification and the recurrence model was induced by IL-1beta. Pathohistology of ulcer healing and recurrence was observed. Density of inflammatory cell infiltrating regenerative mucosa, NF-kappaB protein and mRNA expression were measured. RESULT: JWYY had effects on improving the quality of ulcer healing, reducing the rate of ulcer recurrence, decreasing the density of inflammatory cell infiltrating regenerative mucosa and suppressing the activation and expression quantity of NF-kappaB protein and mRNA. CONCLUSION: JWYY may promote the ulcer healing and prevent the recurrence of the gastric ulcer by suppressing the activation of NF-kappaB and the following inflammatory reaction.

Acetic Acid↗

PubMed2005

Accelerated stochastic simulation of the stiff enzyme-substrate reaction.

The enzyme-catalyzed conversion of a substrate into a product is a common reaction motif in cellular chemical systems. In the three reactions that comprise this process, the intermediate enzyme-substrate complex is usually much more likely to decay into its original constituents than to produce a product molecule. This condition makes the reaction set mathematically "stiff." We show here how the simulation of this stiff reaction set can be dramatically speeded up relative to the standard stochastic simulation algorithm (SSA) by using a recently introduced procedure called the slow-scale SSA. The speedup occurs because the slow-scale SSA explicitly simulates only the relatively rare conversion reactions, skipping over occurrences of the other two less interesting but much more frequent reactions. We describe, explain, and illustrate this simulation procedure for the isolated enzyme-substrate reaction set, and then we show how the procedure extends to the more typical case in which the enzyme-substrate reactions occur together with other reactions and species. Finally, we explain the connection between this slow-scale SSA approach and the Michaelis-Menten [Biochem. Z. 49, 333 (1913)] formula, which has long been used in deterministic chemical kinetics to describe the enzyme-substrate reaction.

Algorithms↗

PubMed2005

Role of keratinocyte growth factor in the pathogenesis of autosomal dominant polycystic kidney disease.

BACKGROUND: Previous studies have shown that the expression and distribution of keratinocyte growth factor (KGF), also known as FGF-7 (fibroblast growth factor-7) or HBGF-7 (heparin-binding growth factor-7), may be implicated in kidney cyst formation and expansion. However, there are no data on KGF expression in human autosomal dominant polycystic kidney disease (ADPKD) tissue, and it is unknown whether it affects ADPKD cyst-lining epithelial cell epithelial cell proliferation. METHODS: The expression and distribution of KGF and KGF receptor (KGFR) mRNA in ADPKD cystic and normal kidney tissues were examined using quantitative real-time polymerase chain reaction (PCR) and in situ hybridization. KGF and KGFR protein expression in the above tissues was analysed by immunohistochemistry and western blot. The effect of KGF on cyst-lining epithelial cell proliferation was assessed by MTT assay, and its effect on the cyst-lining epithelial cell cycle was analysed by flow cytometry. The effect of KGF on cyclin D1 and P21(wafl) gene expression in cyst-lining epithelial cells was also determined. RESULTS: KGF and KGFR mRNA expression in ADPKD cysts was higher than in normal kidney tissues. KGF and KGFR protein expression was also higher in ADPKD cysts and was localized to cyst-lining epithelial cells, tubular and interstitial cells. In vitro experiments revealed that KGF promoted cyst-lining epithelial cell proliferation, and decreased the ratio of G0/G1 phase but increased that of S phase. In response to KGF, the expression of the cyclin D1 gene in cyst-lining epithelial cells increased markedly while P21(wafl) expression decreased. CONCLUSIONS: KGF and KGFR expression was upregulated in ADPKD kidney tissues. KGF stimulated the proliferation of cyst-lining epithelial cell in vitro by regulating the expression of cyclin D1 and P21(wafl) genes. KGF may play a role in pathogenesis of ADPKD.

Adult↗

PubMed2005

Surfactant protein-A inhibits Aspergillus fumigatus-induced allergic T-cell responses.

BACKGROUND: The pulmonary surfactant protein (SP)-A has potent immunomodulatory activities but its role and regulation during allergic airway inflammation is unknown. METHODS: We studied changes in SP-A expression in the bronchoalveolar lavage (BAL) using a murine model of single Aspergillus fumigatus (Af) challenge of sensitized animals. RESULTS: SP-A protein levels in the BAL fluid showed a rapid, transient decline that reached the lowest values (25% of controls) 12 h after intranasal Af provocation of sensitized mice. Decrease of SP-A was associated with influx of inflammatory cells and increase of IL-4 and IL-5 mRNA and protein levels. Since levels of SP-A showed a significant negative correlation with these BAL cytokines (but not with IFN-gamma), we hypothesized that SP-A exerts an inhibitory effect on Th2-type immune responses. To study this hypothesis, we used an in vitro Af-rechallenge model. Af-induced lymphocyte proliferation of cells isolated from sensitized mice was inhibited in a dose-dependent manner by addition of purified human SP-A (0.1-10 microg/ml). Flow cytometric studies on Af-stimulated lymphocytes indicated that the numbers of CD4+ (but not CD8+) T cells were significantly increased in the parental population and decreased in the third and fourth generation in the presence of SP-A. Further, addition of SP-A to the tissue culture inhibited Af-induced IL-4 and IL-5 production suggesting that SP-A directly suppressed allergen-stimulated CD4+ T cell function. CONCLUSION: We speculate that a transient lack of this lung collectin following allergen exposure of the airways may significantly contribute to the development of a T-cell dependent allergic immune response.

Animals↗

PubMed2005

Avoiding negative populations in explicit Poisson tau-leaping.

The explicit tau-leaping procedure attempts to speed up the stochastic simulation of a chemically reacting system by approximating the number of firings of each reaction channel during a chosen time increment tau as a Poisson random variable. Since the Poisson random variable can have arbitrarily large sample values, there is always the possibility that this procedure will cause one or more reaction channels to fire so many times during tau that the population of some reactant species will be driven negative. Two recent papers have shown how that unacceptable occurrence can be avoided by replacing the Poisson random variables with binomial random variables, whose values are naturally bounded. This paper describes a modified Poisson tau-leaping procedure that also avoids negative populations, but is easier to implement than the binomial procedure. The new Poisson procedure also introduces a second control parameter, whose value essentially dials the procedure from the original Poisson tau-leaping at one extreme to the exact stochastic simulation algorithm at the other; therefore, the modified Poisson procedure will generally be more accurate than the original Poisson procedure.

Journal Article↗

PubMed2005

Transforming activity of MECT1-MAML2 fusion oncoprotein is mediated by constitutive CREB activation.

Salivary gland tumors, a group of histologically diverse benign and malignant neoplasms, represent a challenging problem for diagnosis and treatment. A specific recurring t(11;19)(q21;p13) translocation is associated with two types of salivary gland tumors, mucoepidermoid carcinomas and Warthin's tumors. This translocation generates a fusion protein comprised of the N-terminal CREB (cAMP response element-binding protein)-binding domain of the CREB regulator MECT1 (Mucoepidermoid carcinoma translocated-1) and the C-terminal transcriptional activation domain of the Notch coactivator Mastermind-like 2 (MAML2). Here, we demonstrate that the MECT1-MAML2 fusion protein induces expression of multiple genes known to be CREB transcriptional targets. MECT1-MAML2 was found to bind to CREB, recruit p300/CBP into the CREB complex through a binding domain on MAML2, and constitutively activate CREB-dependent transcription. The transforming activity of MECT1-MAML2 was markedly reduced by blocking CREB DNA binding. Thus, this fusion oncogene mimics constitutive activation of cAMP signaling, by activating CREB directly. This study has identified a novel, critical mechanism of transformation for an oncogene associated very specifically with salivary gland tumors, and identified potential targets for the development of novel therapies.

Cell Cycle↗

PubMed2005

Pathophysiology of acute pancreatitis.

Acute pancreatitis is a common clinical condition. It is a disease of variable severity in which some patients experience mild, self-limited attacks while others manifest a severe, highly morbid, and frequently lethal attack. The exact mechanisms by which diverse etiological factors induce an attack are still unclear. It is generally believed that the earliest events in acute pancreatitis occur within acinar cells. Acinar cell injury early in acute pancreatitis leads to a local inflammatory reaction. If this inflammatory reaction is marked, it leads to a systemic inflammatory response syndrome (SIRS). An excessive SIRS leads to distant organ damage and multiple organ dysfunction syndrome (MODS). MODS associated with acute pancreatitis is the primary cause of morbidity and mortality in this condition. Recent studies have established the role played by inflammatory mediators in the pathogenesis of acute pancreatitis and the resultant MODS. At the same time, recent research has demonstrated the importance of acinar cell death in the form of apoptosis and necrosis as a determinant of pancreatitis severity. In this review, we will discuss about our current understanding of the pathophysiology of acute pancreatitis.

Acute Disease↗

PubMed2005

Sensitivity analysis of discrete stochastic systems.

Sensitivity analysis quantifies the dependence of system behavior on the parameters that affect the process dynamics. Classical sensitivity analysis, however, does not directly apply to discrete stochastic dynamical systems, which have recently gained popularity because of its relevance in the simulation of biological processes. In this work, sensitivity analysis for discrete stochastic processes is developed based on density function (distribution) sensitivity, using an analog of the classical sensitivity and the Fisher Information Matrix. There exist many circumstances, such as in systems with multistability, in which the stochastic effects become nontrivial and classical sensitivity analysis on the deterministic representation of a system cannot adequately capture the true system behavior. The proposed analysis is applied to a bistable chemical system--the Schlögl model, and to a synthetic genetic toggle-switch model. Comparisons between the stochastic and deterministic analyses show the significance of explicit consideration of the probabilistic nature in the sensitivity analysis for this class of processes.

Algorithms↗

PubMed2005

The slow-scale stochastic simulation algorithm.

Reactions in real chemical systems often take place on vastly different time scales, with "fast" reaction channels firing very much more frequently than "slow" ones. These firings will be interdependent if, as is usually the case, the fast and slow reactions involve some of the same species. An exact stochastic simulation of such a system will necessarily spend most of its time simulating the more numerous fast reaction events. This is a frustratingly inefficient allocation of computational effort when dynamical stiffness is present, since in that case a fast reaction event will be of much less importance to the system's evolution than will a slow reaction event. For such situations, this paper develops a systematic approximate theory that allows one to stochastically advance the system in time by simulating the firings of only the slow reaction events. Developing an effective strategy to implement this theory poses some challenges, but as is illustrated here for two simple systems, when those challenges can be overcome, very substantial increases in simulation speed can be realized.

Journal Article↗

PubMed2005

Inhibitory effect of tissue transglutaminase (tTG) antisense oligodeoxynucleotides on tTG expression in cultured bovine trabecular meshwork cells.

To study the effect of tTG fully phosphorothioated antisense oligodeoxynucleotides (tTG-ASDON) on tTG expression in cultured bovine trabecular meshwork cells (BTMCs) in vitro and explore a new treatment alternative for primary open angle glaucoma (POAG), the ASDON1 and ASDON2 complementary to the protein codogram region of tTG were designed, synthesized and phosphorothioated according to the secondary structure of tTG. The ASDON1 and ASDON2 were embedded in Lipofectamine and transfected into BTMCs. The untreated group served as negative controls. The expression of tTG in the mRNA and protein level were measured by semi-quantitative RT-PCR and immunohistochemical technique-Supervision method respectively. Our results showed that both the mRNA and the protein of tTG with tTG-ASDON and tTG-ASDON2 were significantly decreased as compared with that of the controls (P < 0.05). On the other hand, no significant difference was found between the ASDON1 group and the ASDON2 group. It is concluded that the expression of tTG mRNA and protein in cultured BTMC are down-regulated by tTG- ASDON. As a result, tTG-ASDON may be used for the treatment of POAG through the inhibitory effect on the expression of tTG.

Animals↗

PubMed2005

The HNF-1 target collectrin controls insulin exocytosis by SNARE complex formation.

Defective glucose-stimulated insulin secretion is the main cause of hyperglycemia in type 2 diabetes mellitus. Mutations in HNF-1alpha cause a monogenic form of type 2 diabetes, maturity-onset diabetes of the young (MODY), characterized by impaired insulin secretion. Here we report that collectrin, a recently cloned kidney-specific gene of unknown function, is a target of HNF-1alpha in pancreatic beta cells. Expression of collectrin was decreased in the islets of HNF-1alpha (-/-) mice, but was increased in obese hyperglycemic mice. Overexpression of collectrin in rat insulinoma INS-1 cells or in the beta cells of transgenic mice enhanced glucose-stimulated insulin exocytosis, without affecting Ca(2+) influx. Conversely, suppression of collectrin attenuated insulin secretion. Collectrin bound to SNARE complexes by interacting with snapin, a SNAP-25 binding protein, and facilitated SNARE complex formation. Therefore, collectrin is a regulator of SNARE complex function, which thereby controls insulin exocytosis.

Animals↗

PubMed2005

[Correlation between the area of arterial blood gases graph and the acid-base disturbance in 92 cases with chronic obstructive pulmonary disease].

OBJECTIVE: To study the correlation between the area of arterial blood gases graph (ABGG) and the acid-base disturbance (ABD). METHODS: Using the software developed by ourselves, the results of arterial blood gases and concomitant electrolyte (K(+), Na(+), Cl(-), HCO(3)(-)) determination in 313 episodes were analyzed in 92 cases with chronic obstructive pulmonary diseases (COPD) during hospitalization, and the correlation was studied. RESULTS: (1)On admission, among 92 cases, in 9 cases the results of blood gas analysis were in the area of compensated ventilation and deranged gas exchange (area IV), in 82 cases the results were in the area of insufficient ventilation and deranged gas exchange (area V), and 1 case in the area of excessive ventilation and deranged gas exchange (area VI). There were 8 types of the ABDs, and respiratory acidosis (RAC)+metabolic alkalosis (MAL), RAC, RAC+metabolic acidosis (MAC) with increase in anion gap (AG) ranked in above order. (2)At the time of discharge, in 2 cases the distribution of ABGG was in the normal area (area I), 5 cases in the area IV, 20 cases in the area V, and 1 case in the area VI. There were 5 types of the ABDs. RAC+MAL and RAC ranked in the first two positions. (3)During hospitalization, the correlations between the area of ABGG and ABD in 313 episodes were as follows: ABD normal and MAC of AG increased in the area I; ABD normal and MAL, MAC with AG increased, RAC+MAC, respiratory alkalosis (RAL)+MAL, MAL+MAC of AG increased, RAC+MAL+MAC of AG increased and RAL+MAL+MAC of AG increased in the area IV; RAC, MAL, RAC+MAL, RAC+MAC of AG increased, MAL+MAC of AG increased, and RAC+MAL+MAC of AG increased in the area V; MAC of AG increased, RAC+MAC, RAL+MAL, MAL+MAC of AG increased, and RAL+MAL+MAC of AG increased in the area VI. No ABD occurred in the areas II and III. CONCLUSION: The correlation between ABGG and ABD can be analyzed easily and quickly and the accuracy of results is ensured by using the software.

Acid-Base Equilibrium↗

PubMed2005

[Clinical observation on acupoint-injection of Chinese drugs for treatment of hypertensive renal lesion].

OBJECTIVE: To compare therapeutic effects of acupoint-injection of Chinese drug and oral administration of Western medicine on hypertensive renal lesion. METHODS: Fifty-seven cases were randomly divided into two groups. The treatment group of 30 cases were treated by injection of Yuxingcao injectio and Danshen injectio into Shenshu (BL 23) and Zusanli (ST 36), and the control group of 27 cases by nifepine. Their therapeutic effects were compared. RESULTS: The markedly effective rate of 46.7% and the total effective rate of 86.7% in the treatment group were significantly higher than 22.2% and 51.8% in the control group (P < 0.05, P < 0.01). There were significant differences in 24h-urinary protein, urinary beta2-microglobulin (beta2-MG) and N-acetyl-beta-D-glucosaminidase (NAG) after treatment between the two groups (P < 0.01). CONCLUSION: The therapeutic effect of acupoint-injection of Chinese drugs is better than that of nifepine and it has protective action on renal function.

Acupuncture Points↗

PubMed2005

[Study on the effect of spinal neural progenitor transplantation on treating brachial].

OBJECTIVE: To explore the effect of spinal neural progenitor transplantation to the cervical spinal on The brachial plexus treating brachial plexus injury with the reimplantation of the avulsed spinal roots. METHODS: avulsed injury model was made on 54 rats and they were evenly divided into 3 groups: fresh group, chronic group, control group. The spinal neural progenitor was cultured and identified. Then 10 microl (1 x 10(5)/microl) cells were labelled with BrdU and transplanted into the fresh group (15 rats survived, being model for 1 week) and the chronic group (14 rats survived, being model for 2 months). No cell was transplanted into the control group. Two months after the transplantation, the recovery of function of the injured limb was evaluated. Electrophysiologic study and immunohistochemical study of the injured limb were made. RESULTS: Spinal neural progenitors were isolated from the spine and became neural sphere. The neural spheres were differentiated into neurons and astrocytes. Fourteen rats out of 15 in the fresh group were recovered, 7 rats out of 14 in the chronic group were recovered, and 5 rats out of 12 in the control group were recovered. Immunohistochemical study indicated that the transplanted progenitors in fresh group survived and differentiated into the neural cells, and the transplanted progenitors in chronic group existed and did not differentiate well. CONCLUSION: Transplanted spinal neural progenitors can promote the recovery of the brachial plexus injury with the reimplantation of the avulsed spinal root.

Animals↗

PubMed2005

[Observation on clinical therapeutic effect of acupoint-injection therapy combined with prednisone on nephrotic syndrome and effect on immunologic function].

OBJECTIVE: To search for the best method for increasing clinical therapeutic effect on nephrotic syndrome. METHODS: Forty-one cases were randomly divided into 2 groups. The treatment group (n=22) were treated with acupoint-injection of Chinese medicine combined with prednisone, and the control group (n=19) with prednisone. Their therapeutic results were observed and compared. RESULTS: The complete remission rate of 45.5% and the total effective rate of 86.4% in the treatment group were significantly higher than 31.6% and 63.2% in the control group, with a significant difference between the two groups in the total effective rate (P < 0.05); in the treatment group, blood lipids decreased, plasma proteins raised and immunologic function improved. CONCLUSION: Acupoint-injection of Chinese medicine combined with prednisone can significantly increase therapeutic effect on nephrotic syndrome and strengthen immunologic function.

Acupuncture Points↗