Biomedical subjects

Xia Zhang

Publications and source records attributed to Xia Zhang.

At least 37 records · Page 2Linked to original sources

PubMed2006

Magnetic study on a two-dimensional coordination polymer with mixed bridging ligands.

A two-dimensional coordination polymer, [Co(mu(1,3)-SCN)(2)(mu(1,6)-dmpzdo)](n)() (where dmpzdo = 2,5-dimethylpyrazine-1,4-dioxide), has been synthesized and its crystal structure determined by X-ray crystallography. In the complex, the adjacent Co(II) ions are coordinated by mu(1,3)-SCN(-) bridging ligands which forms a one-dimensional chain along the a axis; the one-dimensional chains are further connected by mu(1,6)-dmpzdo bridging ligands which leads to the formation of a two-dimensional layer on the ac plane. The theoretical calculations reveal that a ferromagnetic coupling exists between the mu(1,3)-SCN(-) bridging Co(II) ions and an anti-ferromagnetic interaction between the mu(1,6)-dmpzdo bridging Co(II) ions, and the anti-ferromagnetic interaction is stronger than the ferromagnetic interaction. The fitting of the variable-temperature (34-300 K) magnetic susceptibilities reveals that there is an anti-ferromagnetic coupling between the bridging Co(II) ions with the magnetic coupling constant J = -3.52 cm(-1).

Journal Article↗

PubMed2006

Disruption of PTEN coupling with 5-HT2C receptors suppresses behavioral responses induced by drugs of abuse.

The widespread distribution of the tumor suppressor PTEN (phosphatase and tensin homolog deleted on chromosome 10) in the adult brain suggests its role in a broad range of brain functions. Here we show evidence supporting a physical interaction of PTEN with a region in the third intracellular loop (3L4F) of the serotonin 5-HT2C receptor (5-HT2cR, formerly 5-HT1c receptor) in cell cultures. PTEN limits agonist-induced phosphorylation of 5-HT2cR through its protein phosphatase activity. We showed the probable existence of PTEN:5-HT2cR complexes in putative dopaminergic neurons in the rat ventral tegmental area (VTA), a brain region in which virtually all abused drugs exert rewarding effects by activating its dopamine neurons. We synthesized the interfering peptide Tat-3L4F, which is able to disrupt PTEN coupling with 5-HT2cR. Systemic application of Tat-3L4F or the 5-HT2cR agonist Ro600175 suppressed the increased firing rate of VTA dopaminergic neurons induced by delta9-tetrahydrocannabinol (THC), the psychoactive ingredient of marijuana. Using behavioral tests, we found that Tat-3L4F or Ro600175 blocks conditioned place preference of THC or nicotine, and that Ro600175, but not Tat-3L4F, produces anxiogenic effects, penile erection, hypophagia and motor functional suppression. These results suggest a potential strategy for treating drug addiction with the Tat-3L4F peptide.

Animals↗

PubMed2006

Degradation of 17alpha-ethinylestradiol in aqueous solution by ozonation.

This study investigates the ozonation of 17alpha-ethinylestradiol (EE(2)) in aqueous solution. The affecting factors on the degradation of EE(2) were studied and described in details, such as initial EE(2) concentration, initial pH value and ozone concentration. In addition, some parameters such as pH, electrical conductivity, mineralization efficiency and degradation products were monitored during the process. The mineralization efficiency of EE(2) could reach 53.9%. During the ozonation process the rapid decrease of pH and the sharp increase of electrical conductivity indicated the formation of acidic by-products, small fragments and ions which were confirmed by high performance liquid chromatography (HPLC) and gas chromatography-mass spectrometry (GC/MS) analysis. Results showed that there were intermediate products of smaller molecule with higher polarity produced during the course of EE(2) degradation. Then a possible reaction pathway for EE(2) degradation involving all intermediates detected is proposed. During the ozonation process EE(2) was first oxidized into hydroxyl-semiquinone isomers which were subsequently degraded into low molecular weight compounds such as oxalic acid, malonate, glutarate, and so on. Furthermore, these organic acids are easily oxidized by ozone into carbon dioxide (CO(2)). This work shows that ozonation process is promising for the removal of EE(2). The results can provide some useful information for the potential treatment of EE(2) by ozonation in aqueous solution.

Chromatography, High Pressure Liquid↗

PubMed2006

TIP30 inhibits growth of HCC cell lines and inhibits HCC xenografts in mice in combination with 5-FU.

Hepatocellular carcinoma (HCC) is an aggressive cancer with a poor prognosis. The specific cellular gene alterations responsible for hepatocarcinogenesis are not well known. Previous works showed that loss of TIP30, also called CC3, a putative tumor suppressor, increased the incidence of hepatocellular carcinoma in mice, and some clinical samples of human HCC tissues had aberrant expression of TIP30. Here, we report that the introduction of TIP30 by an adenovirus vector into HCC cell lines that had decreased expressions of TIP30 inhibited cell proliferation, decreased anchorage-dependent growth, suppressed invasion through the extracellular matrix, and inhibited tumorigenesis in nude mice. Moreover, exogenous expression of Tip30 sensitized HCC cells to cytotoxic drugs and to apoptosis induced by tumor necrosis factor-related ligands in vitro. Ectopic expression of TIP30 in HCC cells enhanced p53 expression and decreased Bcl-2/Bcl-xL expression. Treatment of nude mice bearing subcutaneously established HCC tumors with a combination of an adenovirus expressing TIP30 and the cytotoxic drug 5-fluorouracil completely suppressed tumor growth and prolonged survival. In conclusion, TIP30 may play an important role in the suppression of hepatocarcinogenesis by acting as a tumor suppressor. Overexpression of TIP30 might be a promising candidate as a treatment for HCC that would increase sensitivity to chemotherapeutic drugs.

Acetyltransferases↗

PubMed2006

Molecular cloning and characterization of a vacuolar H+ -pyrophosphatase gene, SsVP, from the halophyte Suaeda salsa and its overexpression increases salt and drought tolerance of Arabidopsis.

The chenopodiaceae Suaeda salsa L. is a leaf succulent euhalophyte. Shoots of the S. salsa are larger and more succulent when grown in highly saline environments. This increased growth and water uptake has been correlated with a large and specific cellular accumulation of sodium. S. salsa does not have salt glands or salt bladders on its leaves. Thus, this plant must compartmentalize the toxic Na(+) in the vacuoles. The ability to compartmentalize sodium may result from a stimulation of the proton pumps that provide the driving force for increased sodium transport into the vacuole. In this work, we isolated the cDNA of the vacuolar membrane proton-translocating inorganic pyrophosphatase (H(+) -PPase) from S. salsa. The SsVP cDNA contains an uninterrupted open reading frame of 2292 bp, coding for a polypeptide of 764 amino acids. Northern blotting analysis showed that SsVP was induced in salinity treated leaves. The activities of both the V-ATPase and the V-PPase in Arabidopsis overexpressing SsVP-2 is higher markedly than in wild-type plant under 200 mM NaCl and drought stresses. The Overexpression of SsVP can increase salt and drought tolerance of transgenic Arabidopsis.

Adaptation, Physiological↗

PubMed2006

[Comparing serum tumor antigen detection combined with CT scan with PET-CT for lung cancer diagnosis].

BACKGROUND & OBJECTIVE: Positron emission tomography-computed tomography (PET-CT) is a new bio-imaging system which combined metabolic with anatomic imaging. This system has better three-dimensional definition and earlier tumor detection potential. This study was to compare the accuracy of tumor antigen detection combined with CT scan with PET-CT for lung cancer diagnosis and staging. METHODS: A total of 43 lung cancer patients diagnosed by operation or acupuncture, received breast CT scan, tumor antigen detection, and PET-CT scan, were selected. The accuracies of these 2 methods and their impacts on lung cancer staging were compared. RESULTS: The accurate diagnosis rate of tumor antigen detection combined with CT scan was 67.44%, and that of PET-CT scan was 90.70%. Local focus detection rates were 86.05% and 95.35%, respectively; mediastinal lymph nodes detection rates were 65.12% and 83.72%, respectively. PET-CT detected 6 cases of distant metastasis which were not detected by tumor antigen detection combined with CT scan. Compared with CT scan, 5 (11.63%) cases were upstaged and 7 (16.28%) cases were downstaged by PET-CT, which led to therapeutic strategy changes in 4 (9.3%) cases. CONCLUSION: Compare with tumor antigen detection combined with CT scan, PET-CT scan is more sensitive and accurate in diagnosing and staging lung cancer.

Adenocarcinoma↗

PubMed2006

[Clinical observation on chiropractics combined with acupuncture at Sifeng (EX-UE 10) for treatment of infantile anorexia].

OBJECTIVE: To search for an effective therapy for infantile anorexia. METHODS: Sixty-two cases of infantile anorexia were randomly divided into a treatment group and a control group, 31 cases in each group. The treatment group were treated with chiropractics plus acupuncture at Sifeng (EX-UE 10), and the control group with oral administration of zinc gluconate granules made by the pharmaceutical factory of the hospital, for 2 weeks. RESULTS: The effective rate was 93.5% in the treatment group, which was better than 74.2% in the control group (P < 0.05); there were significant differences in blood zinc content and urinary amylase activity in the two groups before and after treatment (P < 0.01), with more significant increase in the treatment group as compared with the control group (P < 0.05). CONCLUSION: Chiropractics combined with acupuncture at Sifeng (EX-UE 10) has a better therapeutic effect on infantile anorexia.

Acupuncture Points↗

PubMed2006

[A clinical analysis of liver disease patients with abnormal glucose metabolism].

OBJECTIVE: To study the clinical features of liver disease patients with abnormal glucose metabolism. METHODS: Liver functions and levels of FPG, PPG, FINS, PINS, FCP, and PCP in 91 chronic hepatitis B patients with abnormal glucose metabolism (62 had liver cirrhosis) were analyzed. RESULTS: (1) The incidence of hepatogenic impaired glucose tolerance (IGT) and of diabetes mellitus (DM) in hepatitis B patients with liver cirrhosis (20.53%; 24.11%) were higher than those without cirrhosis (3.82%; 1.64%; P<0.05, P<0.01). (2) There were no diabetic symptoms among any of the hepatogenic IGT and DM patients. 12 of 19 chronic hepatitis B patients with primary DM and 6 of 12 hepatitis B associated liver cirrhosis patients with primary DM had diabetic symptoms. (3) The levels of FPG and PPG in chronic hepatitis B patients with hepatogenic IGT and DM were lower than those in the patients with primary DM (P<0.05), but the levels of PINS and PCP in chronic hepatitis B patients with hepatogenic IGT and DM were higher than those in the patients with primary DM (P<0.05). (4) There were no differences in the levels of FPG and PPG between the hepatitis B associated liver cirrhosis patients with hepatogenic DM and those with primary DM (P<0.05). The levels of FINS, PINS, FCP, and PCP were higher in the hepatitis B associated liver cirrhosis patients with hepatogenic DM than those in the hepatitis B associated liver cirrhosis patients with primary DM (P<0.05). The levels of FPG and PPG in the hepatogenic DM patients were higher than those in the hepatogenic IGT patients (P<0.05), but their levels of FINS, PINS, FCP and PCP were lower than those in the hepatogenic IGT patients (P<0.05, P<0.01). CONCLUSION: Hepatogenic IGT and DM are always secondary in severe liver cirrhosis patients, who always showed no diabetic symptoms. The chronic hepatitis B patients with hepatogenic DM had increased insulin secretion, while the hepatitis B associated liver cirrhosis patients with hepatogenic DM had decreased insulin secretion.

Blood Glucose↗

PubMed2006

[Total hip arthroplasty for treatment of developmental dysplasia of the hip].

OBJECTIVE: To summarize the techniques of the total hip arthroplasty in the treatment of osteoarthritis secondary to developmental dysplasia of the hip joint (DDH). METHODS: Between February 1986 and November 2004, a total of 32 hips in 24 patients with advanced osteoarthritis secondary to DDH underwent the total hip arthroplasty. Among the patients, 4 were male and 20 were female, with their ages ranging from 33 to 59 years and an average age of 47 years. The bilateral arthroplasty was performed in 8 patients and the unilateral arthroplasty in 16 patients. The patients mainly suffered from pain and claudication. According to the Hartofilakidis classification, semidislocation occurred in 2 hips, low-dislocation in 21 hips, and high-dislocation in 9 hips; and the Harris scores before operation were 56.70 +/- 2.75, 36.09 +/- 4.16, and 29.45 +/- 2.16, respectively. RESULTS: All the patients were followed up for 6 months to 8 years (averaged 3 years and 4 months). The Harris scores after operation were 93.10 +/- 2.10, 92.7 +/- 3.20, and 88.09+/- 3.67, respectively. The differences between preoperation and postoperation were significant (P < 0.01). All the patients were pain-free and there was no sign of aseptic loosening and subsidence. CONCLUSION: The total hip arthroplasty is an effective method for the treatment of osteoarthritis secondary to DDH. The key techniques for the total hip arthroplasty are as follows: deepening the medial wall of the acetabulum, improving the techniques of the bone graft, and firmly placing the acetabular component in the true acetabulum.

Acetabulum↗

PubMed2006

[Study on the characterizations of beta-cyclodextrin-benzoylferrocene-thiosemicarbazone inclusion complex and micro-environmental effects].

Inclusion complex of benzoylferrocene-thiosemicarbazone (TBF) with beta-cyclodextrin (beta-CD) was prepared by using kneading method. Continuous variation plot proved that 2:3 (TBF: beta-CD) inclusion complex has been formed. The characterizations of the inclusion complex were studied by UV, FTIR and X-ray diffractometry. By using the data of UV spectroscopy, the binding constant of the inclusion compound was estimated to be 5.04 x 10(13) (L4 x (mol)(-4)), and its change in absorption with time was studied. The stability of inclusion is obviously greater than the guest molecule. Furthermore, the influences of different solvents and pH on the UV spectra of TBF and beta-CD-TBF were discussed respectively. The results show that different micro-environments have apparently different effects on electric spectra of guest and inclusion complexes.

English Abstract↗

PubMed2006

[A controlled clinical trial of long course chemotherapy regimens containing rifabutin in the treatment of multi-drug resistant pulmonary tuberculosis].

OBJECTIVE: To evaluate the curative effect and safety of a long course regimen containing Chinese-made rifabutin as compared to the regimen containing rifapentine in the treatment of multi-drug resistant pulmonary tuberculosis. METHOD: During 18 month treatment, 130 patients with multi-drug resistant pulmonary tuberculosis were divided into a treatment group (rifabutin, pasiniazide, levofloxacin, ethambutol, ethionamide, amikacin for 3 months, rifabutin, pasiniazide, levofloxacin, ethambutol, ethionamide for 6 months, rifabutin, pasiniazide, levofloxacin, ethambutol for 9 months), and a control group (rifapentine, pasiniazide, levofloxacin, ethambutol, ethionamide, amikacin for 3 months, rifabutin, pasiniazide, levofloxacin, ethambutol, ethionamide for 6 months, rifabutin, pasiniazide, levofloxacin, ethambutol for 9 months) with proportion 1:1 random, and parallel compared method. RESULTS: After intensive phase, the sputum negative conversion rates (smear negative, culture negative) of the treatment group and the control group were 41.54% (27/65) and 35.94% (23/65), chi(2) = 2.42, P > 0.05, respectively. The remarkable effective rates in chest X-ray of the two groups were all 10.77% (7/65), chi(2) = 0.01, P > 0.05, and the effective rates were 67.69% (44/65) and 56.92% (37/65), chi(2) = 1.44, P > 0.05, respectively. At the end of the treatment, the sputum negative conversion rate (smear negative, culture negative) of the treatment group was 75.0% (48/65), and of the control group was 65.08% (41/65), chi(2) = 1.88, P > 0.05. The remarkable effective rates in chest X-ray of the two groups were 46.15% (30/65) and 44.62% (29/65), chi(2) = 0.02, P > 0.05, and the effective rates were 76.92% (50/65) and 73.85% (48/65), chi(2) = 0.19, P > 0.05, respectively. The cavity closure rates were 23.64% (13/55) and 33.33% (17/51), chi(2) = 0.00, P > 0.05, respectively. CONCLUSION: Regimens containing rifabutin or rifapentine. are very effective in sputum negative conversion rate, lesion absorption and cavity closing for the treatment of multi-drug resistant pulmonary tuberculosis, with good safety and tolerance.

Adult↗

PubMed2005

IL-4 inhibits the expression of mouse formyl peptide receptor 2, a receptor for amyloid beta1-42, in TNF-alpha-activated microglia.

Microglia are phagocytic cells in the CNS and actively participate in proinflammatory responses in neurodegenerative diseases. We have previously shown that TNF-alpha up-regulated the expression of formyl peptide receptor 2 (mFPR2) in mouse microglial cells, resulting in increased chemotactic responses of such cells to mFPR2 agonists, including amyloid beta1-42 (Abeta42), a critical pathogenic agent in Alzheimer's disease. In the present study, we found that IL-4, a Th2-type cytokine, markedly inhibited TNF-alpha-induced expression of mFPR2 in microglial cells by attenuating activation of ERK and p38 MAPK as well as NF-kappaB. The effect of IL-4 was not dependent on Stat6 but rather required the protein phosphatase 2A (PP2A) as demonstrated by the capacity of PP2A small interfering RNA to reverse the effect of IL-4 in TNF-alpha-activated microglia. Since both IL-4 and TNF-alpha are produced in the CNS under pathophysiological conditions, our results suggest that IL-4 may play an important role in the maintenance of CNS homeostasis by limiting microglial activation by proinflammatory stimulants.

Amyloid beta-Peptides↗

PubMed2005

PCR and oligonucleotide array for detection of Enterobacter sakazakii in infant formula.

Enterobacter sakazakii has been implicated in a several form of neonatal meningitis with a high mortality rate. In the present study, the species-specific PCR and oligonucleotide array assays were developed to detect the 16S-23S rDNA internal transcribed spacer (ITS) of E. sakazakii. Two pairs of specific PCR primers and 10 oligonucleotide probes were designed by sequencing the ITS of six strains of E. sakazakii and BLAST of GenBank. The specificity and efficiency of the PCR and oligonucleotide array methods were tested against a panel of numerous strains from 88 different bacterial strains. All of the E. sakazakii strains generated positive signal, and no cross-reaction was observed with non-E. sakazakii strains in the PCR and oligonucleotide array detections based on ITS sequences. Sensitivity of the detections is 1.3 CFU/100 g infant formula with the selective enrichment. Both of the PCR and oligonucleotide array procedures take only 48 h including the enrichment culture, whereas the conventional methods required at least 5 days. This study demonstrated that both of the pathogenic detections are time-saved and reliable.

Cronobacter sakazakii↗

PubMed2005

Cannabinoids promote embryonic and adult hippocampus neurogenesis and produce anxiolytic- and antidepressant-like effects.

The hippocampal dentate gyrus in the adult mammalian brain contains neural stem/progenitor cells (NS/PCs) capable of generating new neurons, i.e., neurogenesis. Most drugs of abuse examined to date decrease adult hippocampal neurogenesis, but the effects of cannabis (marijuana or cannabinoids) on hippocampal neurogenesis remain unknown. This study aimed at investigating the potential regulatory capacity of the potent synthetic cannabinoid HU210 on hippocampal neurogenesis and its possible correlation with behavioral change. We show that both embryonic and adult rat hippocampal NS/PCs are immunoreactive for CB1 cannabinoid receptors, indicating that cannabinoids could act on CB1 receptors to regulate neurogenesis. This hypothesis is supported by further findings that HU210 promotes proliferation, but not differentiation, of cultured embryonic hippocampal NS/PCs likely via a sequential activation of CB1 receptors, G(i/o) proteins, and ERK signaling. Chronic, but not acute, HU210 treatment promoted neurogenesis in the hippocampal dentate gyrus of adult rats and exerted anxiolytic- and antidepressant-like effects. X-irradiation of the hippocampus blocked both the neurogenic and behavioral effects of chronic HU210 treatment, suggesting that chronic HU210 treatment produces anxiolytic- and antidepressant-like effects likely via promotion of hippocampal neurogenesis.

Animals↗

PubMed2005

The effect of microwave irradiation on enzymatic hydrolysis of rice straw.

A series of experiments involving microwave irradiation were carried out to evaluate the effect of microwave irradiation on enzymatic hydrolysis of rice straw. Compared with microwave irradiation free hydrolysis, rice straw pretreated by combining microwave irradiation with alkali could increase the initial hydrolysis rate but the hydrolysis yield remained unchanged. When the enzyme solution was treated by microwave irradiation, the initial hydrolysis rate increased slightly, but the yield was decreased remarkably. Its optimal hydrolysis conditions were temperature (45 degrees C), pH (4.8) and enzyme loading (20 mg g(-1) substrate), which was determined by an orthogonal experiment. When intermittent microwave irradiation was used, initial hydrolysis rate was greatly accelerated but the yield was decreased slightly. Its optimal hydrolysis conditions were temperature (50 degrees C), pH (4.8) and enzyme loading (20 mg g(-1) substrate), which was determined by another orthogonal experiment.

Carbohydrates↗

PubMed2005

Role of SPECT/CT in diagnosis of hepatic hemangiomas.

AIM: To investigate the role of SPECT/CT in the diagnosis of hepatic hemangiomas whose anatomical positions are not ideal, situated adjacent to the heart, the inferior cava, hepatic vessels or abdominal aorta, etc. METHODS: The hepatic perfusion, blood pool, and fusion imaging were carried out using SPECT/CT in 54 patients, who were suspected for hepatic hemangiomas. When the anatomical positions were not ideal, the diagnosis was difficult by SPECT only. So the information of computed tomography (CT) was applied to help in diagnosing. The results were recorded as hemangiomas or not. RESULTS: Of the 54 patients, 31 patients were diagnosed as suffering from hepatic hemangiomas. The anatomical positions of eight patients' hepatic hemangiomas (25.81%) were not ideal. Among these lesions of the eight patients, three patients' hepatic lesions were located near to the abdominal aorta, one to the heart, and four to the inferior cava. In addition, six abnormal radioactivity accumulation regions, adjacent to the heart and inferior cava, with the help of CT, were confirmed to be the imaging of inferior cava other than hepatic hemangiomas. CONCLUSION: When the anatomical positions of hepatic hemangiomas are not good enough for diagnosis, the fusion imaging of SPECT/CT is a simple and efficient method for differential diagnosis.

Adult↗

PubMed2005

Involvement of extracellular regulated kinase and p38 kinase in hippocampal seizure tolerance.

The mechanisms underlying brain seizure tolerance, a phenomenon in which brief periods of seizures protect brain against the lethal effects of subsequent sustained seizures, are poorly understood. Because brain seizure tolerance and brain ischemia tolerance likely share certain common mechanisms, the recent evidence that activation of extracellular regulated kinase (ERK) and p38 kinase pathways plays a critical role in ischemic preconditioning suggests that a similar mechanism may underlie brain seizure tolerance. We investigated the hypothesis in a rat kainic acid preparation of seizure preconditioning and tolerance, which was established by induction of one episode of priming epileptic status lasting for 20 min on the first day and another episode of sustained epileptic status lasting for 2 hr on the second day. We observed that acute seizures lead to a rapid activation of ERK and p38 in the hippocampal CA3 area, the brain region most susceptible to the lethal effects of epileptic status. Pretreatment with the ERK inhibitor PD98059 and the p38 inhibitor SB203580 selectively reduces seizure-elicited activation of ERK and p38, respectively, and significantly reduces priming seizure-induced protection of CA3 neurons. These findings indicate that, similar to brain ischemia tolerance, brain seizure tolerance also involves the ERK and p38 signaling pathways.

Animals↗

PubMed2005

Real time PCR using TaqMan and SYBR Green for detection of Enterobacter sakazakii in infant formula.

Enterobacter sakazakii is an emerging pathogen that causes meningitis, bacteremia, sepsis, and necrotizing enterocolitis in neonates and children. Powdered milk-based infant formulas have been associated with the E. sakazakii-related outbreaks in premature or other immunocompromised infants. In this study, we developed two real time PCR assays using TaqMan and SYBR Green to identify the pathogen after selective enrichment in mLST and BHI. The accuracy of two detections was tested by 35 strains of E. sakazakii and 88 non-E. sakazakii bacterial strains. The results showed that all of these E. sakazakii strains were positive reaction to the detections and all of the non-E. sakazakii strains were negative. The newly developed assays enable us to detect 1.1 CFU/100 g infant formula. And both of the assays can be accomplished within 2 business days. Compared to the traditional detection, the real time PCR procedures are quicker and simpler. In this study, we also developed a new method to design the primers, which can support multiple real time PCR with one pair of primers in SYBR Green detection. The detection methods are more sensitive and effective based on Two-Tm-Value of PCR.

Animals↗