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Biomedical subjects

Jun Zhou

Publications and source records attributed to Jun Zhou.

At least 55 records · Page 3Linked to original sources
PubMed2006

Overexpression of cannabinoid receptors CB1 and CB2 correlates with improved prognosis of patients with hepatocellular carcinoma.

CB1 and CB2 are multifunctional cannabinoid-specific receptors considered to be involved in inhibition of tumor development. To elucidate their roles in hepatocarcinogenesis, we analyzed the expression of these receptors in tumor and matched nontumorous tissues of human hepatocellular carcinoma (HCC) samples. In situ hybridization analysis showed overexpression of CB1 mRNAs in 8 of 13 (62%) HCC samples, and of CB2 mRNAs in 7 of 13 (54%). Immunohistochemical analysis of 64 HCC samples showed the expression of CB1 and CB2 receptors to increase from normal liver to chronic hepatitis to cirrhosis. Marked expression of CB1 and CB2 receptors was noted in the majority of cirrhotic liver samples (86 and 78%, respectively). In HCC, high expression of CB1 and CB2 receptors was observed in 29 (45%) and 33 (52%) cases, respectively. Clinicopathological evaluation indicated a significant correlation between CB1 and CB2 expression and two clinicopathological parameters such as the histopathological differentiation (P = 0.021 and 0.001, respectively), portal vein invasion (P = 0.015 and 0.004, respectively). Univariate analysis indicated that disease-free survival was significantly better in HCC patients with high versus those with low CB1 and CB2 expression levels (P = 0.010 and 0.037, respectively). Our results indicate that CB1 and CB2 have potential as prognostic indicators and suggest possible beneficial effects of cannabinoids on prognosis of patients with HCC.

Adult↗
PubMed2006

Piezoelectric and semiconducting coupled power generating process of a single ZnO belt/wire. A technology for harvesting electricity from the environment.

This paper presents the experimental observation of piezoelectric generation from a single ZnO wire/belt for illustrating a fundamental process of converting mechanical energy into electricity at nanoscale. By deflecting a wire/belt using a conductive atomic force microscope tip in contact mode, the energy is first created by the deflection force and stored by piezoelectric potential, and later converts into piezoelectric energy. The mechanism of the generator is a result of coupled semiconducting and piezoelectric properties of ZnO. A piezoelectric effect is required to create electric potential of ionic charges from elastic deformation; semiconducting property is necessary to separate and maintain the charges and then release the potential via the rectifying behavior of the Schottky barrier at the metal-ZnO interface, which serves as a switch in the entire process. The good conductivity of ZnO is rather unique because it makes the current flow possible. This paper demonstrates a principle for harvesting energy from the environment. The technology has the potential of converting mechanical movement energy (such as body movement, muscle stretching, blood pressure), vibration energy (such as acoustic/ultrasonic wave), and hydraulic energy (such as flow of body fluid, blood flow, contraction of blood vessels) into electric energy that may be sufficient for self-powering nanodevices and nanosystems in applications such as in situ, real-time, and implantable biosensing, biomedical monitoring, and biodetection.

Electric Conductivity↗
PubMed2006

Piezoelectric field effect transistor and nanoforce sensor based on a single ZnO nanowire.

Utilizing the coupled piezoelectric and semiconducting dual properties of ZnO, we demonstrate a piezoelectric field effect transistor (PE-FET) that is composed of a ZnO nanowire (NW) (or nanobelt) bridging across two Ohmic contacts, in which the source to drain current is controlled by the bending of the NW. A possible mechanism for the PE-FET is suggested to be associated with the carrier trapping effect and the creation of a charge depletion zone under elastic deformatioin. This PE-FET has been applied as a force/pressure sensor for measuring forces in the nanonewton range and even smaller with the use of smaller NWs. An almost linear relationship between the bending force and the conductance was found at small bending regions, demonstrating the principle of nanowire-based nanoforce and nanopressure sensors.

Elasticity↗
PubMed2006

Effects of resistant starch, a non-digestible fermentable fiber, on reducing body fat.

OBJECTIVE: To assess the effects of energy dilution with non-fermentable and fermentable fibers on abdominal fat and gut peptide YY (PYY) and glucagon-like peptide (GLP)-1 expressions, three rat studies were conducted to: determine the effects of energy dilution with a non-fermentable fiber, compare similar fiber levels of fermentable and non-fermentable fibers, and compare similar metabolizable energy dilutions with fermentable and non-fermentable fibers. RESEARCH METHODS AND PROCEDURES: In Study 1, rats were fed one of three diets with different metabolizable energy densities. In Study 2, rats were fed diets with similar fiber levels using high amylose-resistant cornstarch (RS) or methylcellulose. In Study 3, rats were fed diets with a similar dilution of metabolizable energy using cellulose or RS. Measurements included food intake, body weight, abdominal fat, plasma PYY and GLP-1, gastrointestinal tract weights, and gene transcription of PYY and proglucagon. RESULTS: Energy dilution resulted in decreased abdominal fat in all studies. In Study 2, rats fed fermentable RS had increased cecal weights and plasma PYY and GLP-1, and increased gene transcription of PYY and proglucagon. In Study 3, RS-fed rats had increased short-chain fatty acids in cecal contents, plasma PYY (GLP-1 not measured), and gene transcription for PYY and proglucagon. DISCUSSION: Inclusion of RS in the diet may affect energy balance through its effect as a fiber or a stimulator of PYY and GLP-1 expression. Increasing gut hormone signaling with a bioactive functional food such as RS may be an effective natural approach to the treatment of obesity.

Adipose Tissue↗
PubMed2006

Peptide YY and proglucagon mRNA expression patterns and regulation in the gut.

OBJECTIVE: Peptide YY (PYY) and glucagon-like peptide-1 are important in the control of energy homeostasis and are both secreted from the gut in response to ingested nutrients. However, more studies are needed on nutrient regulation of their gene expression patterns in specific areas of the gut. This study detailed PYY and proglucagon (the gene that encodes glucagon-like peptide-1) gene expression patterns and regulation in the gut. We further examined the regulation of PYY and proglucagon mRNA by a diet containing fermentation-resistant starch (in vivo) and butyrate (in vitro). RESEARCH METHODS AND PROCEDURES: Quantitative real time reverse transcriptase-polymerase chain reaction was used to measure PYY and proglucagon gene expression in epithelial cells collected from the duodenum, jejunum, cecum, and colon in normal Sprague-Dawley rats and in rats fed a resistant starch diet for 4 weeks. The same measurements were also performed in primary epithelial cells collected from the cecum and colon of normal rats after the cells were incubated with butyrate for 3 hours. RESULTS: The gene expression patterns for PYY and proglucagon are similar to their peptide distribution patterns in the gut. Also, PYY and proglucagon mRNA expression were up-regulated in the cecum and colon in resistant-starch-fed rats. Butyrate increased PYY and proglucagon gene expression in a dose-dependent manner in vitro. DISCUSSION: Our data provide evidence that the distal part of the gut has the ability to sense nutrients such as butyrate, resulting in the up-regulation of PYY and proglucagon gene expression.

Animals↗
PubMed2006

Origins of isotopomeric polymorphism.

The complex formed between 4-methylpyridine and pentachlorophenol (4MPPCP) crystallises in a triclinic space group. If the same complex is synthesized from deuterated pentachlorophenol, it crystallizes in an entirely different monoclinic polymorph. Using solid-state NMR of samples synthesized with a full range of deuteration levels, crystallized from solution or the melt, and in the presence or absence of seeds, we have confirmed that the isotopomers indeed have different thermodynamically stable crystal structures. The roots of this phenomenon of isotopomeric polymorphism apparently lie in the differences in hydrogen bonding between the polymorphs. The triclinic form has a relatively short hydrogen bond. High-field solid-state NMR shows both the 1H chemical shift and the 2H electric quadrupole coupling of the hydrogen involved in the bond to be strongly temperature-dependent, indicating a low-lying excited state of the hydrogen bond longitudinal vibration. Inelastic neutron scattering of isotopomers of 4MPPCP has allowed us to identify the three orthogonal vibrational modes of the hydrogen in the hydrogen bond, at 29.7, 145, and 205 meV (240, 1168, and 1651 cm(-1)). The longitudinal mode is the lowest in energy, and it indicates a slightly asymmetric low-barrier double-well potential. Intrinsic to such potentials is a very small difference in zero-point energies (ZPEs) between the protonated and deuterated forms. As a contrast, the monoclinic form has a comparatively normal hydrogen bond, in which the proton and deuteron ZPEs should be different by approximately 500 cm(-1). A scenario can be envisaged where the triclinic protonated form is lower in energy than the monoclinic protonated form, but the triclinic deuterated form is higher in energy than the monoclinic deuterated form. This evidently accounts for the difference in relative stabilities of the two forms upon isotope substitution.

Crystallization↗
PubMed2006

Treatment of hormone-refractory breast cancer: apoptosis and regression of human tumors implanted in mice.

Following surgery, the hormone dependence of breast tumors is exploited for therapy using antagonists such as tamoxifen, although occasional hormone-resistant clones do appear. Another chemotherapeutic strategy uses microtubule inhibitors such as taxanes. Unfortunately, these agents elicit toxicities such as leukocytopenia, diarrhea, alopecia, and peripheral neuropathies and are also associated with the emergence of drug resistance. We have previously described a tubulin-binding, natural compound, noscapine, that was nontoxic and triggered apoptosis in many cancer types albeit at 10 mumol/L or higher concentrations depending on the cell type. We now show that a synthetic analogue of noscapine, 9-bromonoscapine, is approximately 10-fold to 15-fold more potent than noscapine in inhibiting cell proliferation and induces apoptosis following G2-M arrest in hormone-insensitive human breast cancers (MDA-MB-231). Furthermore, a clear loss of mitochondrial membrane potential, release of cytochrome c, activation of the terminal caspase-3, and the cleavage of its substrates such as poly(ADP-ribose) polymerase, suggest an intrinsic apoptotic mechanism. Taken together, these data point to a mitochondrially mediated apoptosis of hormone-insensitive breast cancer cells. Human tumor xenografts in nude mice showed significant tumor volume reduction and a surprising increase in longevity without signs of obvious toxicity. Thus, our data provide compelling evidence that 9-bromonoscapine can be useful for the therapy of hormone-refractory breast cancer.

Animals↗
PubMed2006

Poly (ethylenimine)-grafted-poly [(aspartic acid)-co-lysine], a potential non-viral vector for DNA delivery.

A potential non-viral gene-transfer vector, poly(ethylenimine)-grafted-poly[(aspartic acid)-co-lysine] (PSL), has been developed by thermal polycondensation of aspartic acid and lysine under reduced pressure. Low-molecular-mass branch poly(ethylenimine) (PEI600) was conjugated to the backbone. The chemical structure of the resulting co-polymer was identified by 1H-NMR, FT-IR, TGA and X-ray diffraction. The results of the MTT assay showed that at concentration up to 4000 nmol/l of the vector cell viability was over 80% and showed low toxicity. Electrophoretic retardation and ethidum bromide assay showed that at N/P ratios 12-15 (w/w) the DNA could be condensed and neutralized. Using the zeta potential assay we discovered that it had a high positive charge on its surface of the particle (over 30 mV). The particle sizes of the co-polymer/DNA complexes were 150-170 nm, as measured by DLS and AFM. Compared with PEI600, co-polymer/DNA complexes showed a significant enhancement of transfection activity in the absence and presence of serum in NT2 and COS7 cell lines. This means that the PEI600-PSL co-polymer is a promising candidate for gene delivery.

Animals↗
PubMed2006

Focusing properties of a photonic crystal slab with multiple mechanisms in addition to negative refraction.

A brief review of imaging by a photonic crystal (PC) slab with negative refraction is given. The focusing properties of the PC with multiple mechanisms in addition to negative refraction are studied by the finite-difference time-domain method. In addition to the effect of negative refraction, there are multiple mechanisms that are all attributed to the PC focusing properties, including Bragg diffraction, excitation of the surface mode, and self-collimation. The resulting field pattern is the total result of these factors. Bragg diffraction occurs in the high-frequency domain and mainly influences the quality of focusing in the optical axis direction. The excitation of the surface mode improves the resolution of focusing. Self-collimation makes the focusing position deviate from Snell's law.

Journal Article↗
PubMed2006

[Effect of guizhi decoction on PKA and PKC activities of hypothalamus in fever rats].

OBJECTIVE: To investigate the changes of the activity of both protein kinase A and C and the mechanisms of antipyretic action of Guizhi decoction. METHOD: The fever responses were observed after combination injection of H-89 (a selective inhibitor of PKA) and calphostin C (a selective inhibitor of PKC), and oral pretreatment of Guizhi decoction in fever rats induced by an intra-cerebroventricular (icv) injection of an EP3 agonist, and both PKA and PKC activity in hypothalamus were measured in rats pretreated with Guizhi decoction and vehicle using isotopic tracing assay. RESULT: The rise in rat body temperature was inhibited by H-89, Calphostin C, and Guizhi decoction, moreover, pretreatment with Guizhi decoction reduced PKA activity obviously. PKC activity in model rats exhibited a tendency to drop compared with that of control group, Oral administration of Guizhi decoction in large dose inhibited the response significantly, while the low dose of Guzhi decoction has no effect on PKC. CONCLUSION: Both PKA and PKC may participate in the mechanism of fever induction by EP3 agonist. The decrease of PKA and PKC may contribute to the antipyretic action of Guizhi decoction, some isoenzyme of PKC may play a role in the fever production.

Analgesics, Non-Narcotic↗
PubMed2006

[Impact on the model of rat osteoarthritis of jingu tablet].

OBJECTIVE: To observe the influence of Jingu tablet (JGT) on the development and repair of osteoarthritis (OA). METHOD: The admixture of 4% papain and 0.3 mol x L(-1) cysteine was injected into the rat's knee joint to make the model of rat OA, and distilled water, Gucining Capsule and JGT was given ig simultaneously to treat for 4 weeks in succession, and then animals were killed to measure every index. RESULT: JGT could obviously improve the scope of activities of knee joint. There were significant differences between every dosage group and model group. In every dosage group, JGT could suppress the swelling of thickness of slippery membrane of joint, alleviate the inflammation symptoms of OA and obviouslical improve the pathologicol changes of slippery membrane and cartilage. JGT could also obviously reduce the content of MDA of slippery membrane and lighten the degree of cell damage. CONCLUSION: JGT can lighten the retrograde affection of joint cartilage, obviously suppress the slippery membrane's inflammation and alleviate the scathing degree of cell. Therefore JGT has definite remedial effect to OA.

Animals↗
PubMed2006

[Process of human platelets loaded with rehalose before lyophilization].

The aim of this research was to study the technology and methods of loading lyoprotectant-trehalose into cytoplasm of human platelets before lyophilization, to optimize experimental conditions of loading trehalose, to investigate the changes of platelets response to agonists and activation after incubation of platelets for 4 hours at 37 degrees C in the presence of lyoprotectant-trehalose, to protract the figures of loading efficiency and intracellular trehalose concentration versus incubation time, temperature and external trehalose concentration, to optimize loading parameters. The response of platelets to different agonists--thrombin, ADP, collagen and ristocetin were measured respectively by APACT2 aggregometer before and after loading trehalose into platelets; the expressions of CD62p and PAC-1 on platelet membranes in the presence and absence of reversible platelets activation inhibitors were measured by flow cytometry respectively before and after loading trehalose into cytoplasm of platelets. The results showed that the loading efficiency was linear to incubation time (2 hours later) and incubation temperature (rang from 30 degrees C to 40 degrees C), respectively. The loading efficiency almost reached 60% when the platelets were incubated at 37 degrees C for 4 hours. The intracellular trehalose concentration was higher with the increase of the extracellular trehalose concentration (< 50 mmol/L). Compared to untreated groups, the values of MPV and aggregation to different agonists in treated groups showed no significant difference, respectively (P > 0.01). After incubation of platelets for 4 hours, the expression of CD62p increased to some extent, however, the expression of CD62p decreased again when the reversible platelets activation inhibitor PGE-1 and adenosine were added to the incubation buffer. It is concluded that 37 degrees C, 4 hours and the extracellular trehalose concentration < 50 mmol/L are the optimal conditions for loading with trehalose. The processing of loading with trehalose before platelet lyophilization has no significant effects on response of platelets to agonists and activation.

Blood Platelets↗
PubMed2006

[Impact of PBDE-209 exposure during pregnancy and lactation on immune function of offspring rats].

OBJECTIVE: To assess the potential hazard of environmental deca-brominated diphenyl ether (PBDE-209) exposure to the immune function of the offspring rats. METHODS: The parental Wistar rats were exposed to PBDE-209 administered intragastrically during pregnancy and lactation, and the development of the immune organs and changes in T lymphocyte subset and their proliferation, NK cell surface markers CD161 and serum immunoglobulins (IgM and IgG) were observed. RESULTS: Significant differences in the weight of the immune organs were noted between the exposure group and control group. In the exposure group, the percentage of T lymphocyte subset CD3(+), CD4(+), CD8(+), CD4(+)CD8(+), the percentage of NK cell surface markers CD16 1 and CD4(+)/CD8(+) ratio were lowered, while the percentage of CD4(-)CD8(-) cells increased. T lymphocyte subset proliferation in the exposure group did not show obviously changes, but compared with the control group, the IgM level in the exposure group was significantly lowered. No significant differences were observed in IgG levels between the exposure and control groups. CONCLUSION: Continuous exposure to high-dose PBDE-209 in female rats during pregnancy and lactation results in possible adverse effect on the immune function of the offspring rats.

Animals↗
PubMed2006

[Surgery therapy of Crohn disease complicated with fistula].

OBJECTIVE: To investigate the surgical treatment of Crohn disease(CD) complicated with perforation or fistula. METHODS: The clinical data of 24 CD cases complicated with perforation or fistula treated in our department from Jan. 1980 to Apr. 2005 were analyzed retrospectively. RESULTS: There were 24 cases of CD complicated with perforation or fistula among 181 CD patients,and the incidence of perforation or fistula was 13.3%. Steroid treatment before perforation was given in 8 patients, while not in 9 patients and unclear in 7 patients. Eighteen patients had single perforation, 4 patients two free perforations and 2 patients more than three extra-abdominal fistula. Emergency operation was performed in 8 cases and selective operation in 16 cases. Five cases had postoperative complications including incision infection in 2, intra-abdominal abscess in 2 and stomal fistula in one case, and were all cured by surgical drainage and anti-infection treatment. The morbidity rate was 20.8%. The postoperative mortality rate was 12.5% (3/24). Eighteen patients were followed up from 6 months to 18 years, and the 5-year recurrent rate was 16.7%. The 10-year reoperation rate was 33.3%. CONCLUSIONS: Steroid use is not the main cause of perforation or fistula in CD. Perforation or fistula is the definite indication for surgical treatment.

Adolescent↗
PubMed2006

[Expression of Ang2 and Tie2 and their relation with the angiogenesis of hepatocellular carcinoma in rats].

OBJECTIVE: To investigate the relationship between the expression of Ang2, Tie2 and the angiogenesis of hepatocellular carcinoma in rats. METHODS: Thirty-eight healthy male rats were randomly divided into 3 groups: 5 rats in the control group; 25 rats in the experimental group were equally divided into 5-day, 10-day, 15-day, 20-day, and 25-day groups; the other 8 rats were used as the supplement of the experimental group. An allogenic transplanted rat model of CBRH-7919 hepatocellular carcinoma in situ was established by immunosuppression. The expressions of Ang2 and Tie2 were detected by immunohistochemical staining in cancerous tissues of different developmental stages and liver tissues of the control group. At the same time, microvessel density was determined by anti-CD31 immunohistochemical staining. RESULTS: CBRH-7919 hepatocellular carcinoma models were successfully set up in 24 rats. The expression level of Ang2 and Tie2 in cancerous tissues was much higher than that of liver tissues of the control group (P <0.05). The overexpression of Ang2 was pristine and continuous in different developmental stages. The expressions of Ang2 and Tie2 positively correlated with microvessal density in hepatocellular carcinoma (P<0.05). CONCLUSION: The up-regulation of Ang2 and Tie2 may play important roles in the angiogenesis of hepatocellular carcinoma. Ang2 may participate in the start of angiogenesis of hepatocellular carcinoma.

Angiopoietin-2↗
PubMed2006

Noninvasive imaging of atherosclerotic lesions in apolipoprotein E-deficient and low-density-lipoprotein receptor-deficient mice with annexin A5.

UNLABELLED: Transgenic mice such as apolipoprotein E-deficient (apoE(-/-)) and low-density-lipoprotein receptor-deficient (LDLR(-/-)) mice exhibit hypercholesterolemia and develop complex atherosclerotic lesions similar to those seen in humans. Radiolabeled annexin A5 has been successfully used to noninvasively image experimental and clinical atherosclerotic disease. We evaluated the feasibility of annexin A5 imaging in transgenic apoE(-/-) and LDLR(-/-) mice with or without a cholesterol diet. METHODS: Thirty-three mice (mean age, 62 +/- 0.9 wk old) were used. Of these 33 mice, apoE(-/-) mice with the cholesterol diet for 4 mo (n = 5) and without the cholesterol diet (n = 8) and LDLR(-/-) mice with the cholesterol diet for 6 mo (n = 7) and without the cholesterol diet (n = 7) were compared with 6 normal wild-type (C57BL/6) mice with the same genetic background. (99m)Tc-annexin A5 was injected in 31 animals for noninvasive imaging using micro-SPECT/CT. After in vivo micro-SPECT/CT, aortas were explanted to acquire ex vivo images and calculate the percentage injected dose per gram (%ID/g) annexin uptake, followed by histologic and immunohistochemical characterization. For the evaluation of precise target localization, biotinylated annexin A5 was injected in the remaining 2 normally fed apoE(-/-) mice. RESULTS: Aortic lesions were clearly visualized noninvasively by micro-SPECT and aorta calcification was detectable by micro-CT. The quantitative uptake of annexin A5 was highest in the cholesterol-fed apoE(-/-) (0.88 +/- 0.27 %ID/g) mice, followed by the normal chow-fed apoE(-/-) (0.60 +/- 0.16 %ID/g), the cholesterol-fed LDLR(-/-) (0.59 +/- 0.14 %ID/g), the chow-fed LDLR(-/-) (0.40 +/- 0.31 %ID/g), and the control (0.15 +/- 0.05 %ID/g) mice. The histologic extent of atherosclerosis paralleled radiotracer uptake, and immunohistochemical studies revealed a significant correlation between radiotracer uptake and both macrophage infiltration and the extent of apoptosis. Intravenously injected biotinylated annexin A5 localized in apoptotic and nonapoptotic macrophages. CONCLUSION: This study demonstrates the feasibility of noninvasive imaging of atherosclerosis with radiolabeled annexin A5 in transgenic mouse models of human atherosclerosis.

Animals↗