Biomedical subjects

Yi Ding

Publications and source records attributed to Yi Ding.

At least 73 records · Page 4Linked to original sources

PubMed2005

[Value of 18F-fluorodeoxyglucose positron emission tomography in three-dimensional conformal radiotherapy for locally persistent or recurrent nasopharyngeal carcinoma].

OBJECTIVE: To explore the clinical value of (18)F-fluorodeoxyglucose positron emission tomography ((18)FDG-PET) in three-dimensional conformal radiotherapy (3D-CRT) for locally residual and recurrent nasopharyngeal carcinoma (NPC). METHODS: Between July 1998 and October 2000, 36 patients with recurrent or residual NPC confirmed by biopsy after initial radiotherapy underwent treatment with 3D-CRT. CT simulation was performed and (18)FDG-PET carried out for delineating the gross tumor volume (GTV) in all the patients. The radiotherapy was designed by 3D treatment planning system and dose-volume histogram (DVH) was used to verify and optimize the radiation plan. Acute and late radiation injuries, survival rates and GTV delineated by CT and (18)FDG-PET were observed in all the cases after the treatment. RESULTS: In comparison with CT simulation, (18)FDG-PET delineated similar GTV in 36.1% (13/36) cases, larger and smaller GTV in 16.7% (6/36) and 47.2% (17/36) of the cases, respectively. After 3D-CRT, 97.2%, 75.0%, and 58.3% of the patients were free of evidence of 1-, 2-, and 3-year local failure, respectively, and the 1-, 2-, and 3-year survival rate of the patients were 94.4%, 86.1%, and 72.0%. The 1-, 2-, 3-year tumor-free survival rates were 85.7%, 76.6%, and 56.1% respectively. Acute xerostomia, nasopharyngitis and oropharyngitis were the most common complications in relation to the radiation, but all within acceptable range of grades 1 or 2. The lesions resulting from the radiation included hearing loss, trismus, dysphagia, chronic sinusitis, and cranial neuropathy, with the incidences of 5.6% (2/36), 25.0% (9/36), 8.3% (3/36), 33.3% (12/36), and 13.9% (5/36) respectively. CONCLUSIONS: 3D-CRT combined with (18)FDG-PET for delineation of GTV is effective and feasible in the treatment of locally residual or recurrent nasopharyngeal carcinoma after initial radiotherapy, producing good responses without serious complications.

Adult↗

PubMed2005

[Effect of pulsed Nd: YAG laser irradiation on periodontal ligament fibroblast cultures].

OBJECTIVE: To evaluate the effect of the pulsed Nd: YAG laser irradiation on the survival rate of human penodontal ligament fibroblast (PDLF) at different power and irradiation time settings, and to compare the morphological change of cells before and after irradiation. METHODS: The cells were cultured and placed into the 96-well tissue culture plates. Cells were divided into groups according to the irradiation time (10 s, 20 s, 40 s, 60 s) and the output energy (0.5 W, 1.0 W, 1.5 W, 2.0 W, 2.5 W). After the irradiation, the cell number were counted and the survival rates were calculated. The correlation between the survival rate and irradiation time as well as power output was analyzed. RESULTS: No significant reduction of survival rates were found in 10 s group, as well as in 20 s group with 0.5 W, 1.0 W setting. The increase of the power output and increase of the irradiation time caused significant reduction of cell survival rate (P <0.05). The irradiation time was more relevant to this reduction than the power output. CONCLUSION: It indicates that the laser irradiation may cause damage to PDLF and decrease the cell survival rate. The irradiation time is more related to this effect than the power output.

Fibroblasts↗

PubMed2005

[Detection of methylation of hMSH2 gene promoter region of esophageal cancer].

OBJECTIVE: To detect methylation in promoter region of hMSH2 gene in esophageal cancer. METHODS: Specimens of cancer and normal tissues freshly removed from 32 cases of esophageal cancer patients without previous radiotherapy, chemotherapy or other treatment were preserved at -80 degrees C within 30 min. Methylation specific PCR (MSP) was used to detect methylation of mismatch repair gene (MMR) hMSH2 in promoter region in esophageal cancer and normal esophageal tissues. RESULTS: The frequencies of methylation of hMSH2 gene in promoter region of cancer and normal esophageal tissues were 32.4% (11/32) and 0/30 (0%), respectively, and significant difference was found between the two groups (P < 0.01). The frequency of methylation in elder patients (> or = 70 years old) was significantly higher than that in younger patients (< 70 years old) (P < 0.05). Methylation was less frequently found in grade I-II (18.2%) than in grade III-IV (70.0%) (P < 0.05). CONCLUSION: Methylation of hMSH2 gene in promoter region is related to patients' age and histopathological grade of the esophageal cancer.

Aged↗

PubMed2005

[A novel fluorophotometric method for assaying free glutathione of both reduced and oxidized in plasma].

To investigate the measurement of free glutathione of both reduced or oxidized (i.e. GSH and GSSG) in plasma, and to evaluate the redox state of GGSH/GSSG in human plasma, both GSH and GSSG in plasma were measured by fluorophotometry based on the facts that one molar GSSG can be reduced to two molar GSH by dithiothreitol(DTT) under the condition of the pH being about 6.0, and GSH can provide both primary amine and thiol groups to react with the two carbonyl groups of O-phthaldehyde (OPA) to form a fluorescent ternary isoindole complex at pH 8.0. This method can at least measure 16 picomole GSH and 8 picomole GSSG respectively in the tube. The variation coefficient (CV) for intra-ssay and intera-ssay is about 4. 6% and 3.9% for GSH and 3.5% and 4.1% for GSSG respectively. The recovery of GSH and GSSG added to the plasma is (99.77% +/- 5.70)% and (99.28% +/- 4.73)% respectively. The concentration of GSH and GSSG in the plasma of young healthy volunteer is (16.5 +/- 2.4) nmol x mL(-1) and (1.7 +/- 0.35)nmol x mL(-1) respectively, without significant difference between male and female. This measurement method is simple with great sensitivity and selectivity for rapid measuring GSH and GSSG in human plasma simultaneously.

Female↗

PubMed2004

Heterodimeric interaction and interfaces of S100A1 and S100P.

With the widespread use of yeast two-hybrid systems, many heterodimeric forms of S100 proteins have been found, although their biological significance is unknown. In the present study, S100A1 was found to interact with another S100 protein, S100P, by using the yeast two-hybrid system. The binding parameters of the interaction were obtained using an optical biosensor and show that S100P has a slightly higher affinity for S100A1 (K(d)=10-20 nM) when compared with that for self-association (K(d)=40-120 nM). The physical interaction of S100A1 and S100P was also demonstrated in living mammalian cells using a fluorescence resonance energy transfer technique. Preincubation of recombinant S100P with S100A1, before the biosensor assay, reduced by up to 50% the binding of S100P to a recombinant C-terminal fragment of non-muscle myosin A, one of its target molecules. Site-specific mutations of S100P and S100A1, combined with homology modelling of an S100P/S100A1 heterodimer using known S100P and S100A1 structures, allowed the hydrophobic interactions at the dimeric interface of the heterodimer to be defined and provide an explanation for the heterodimerization of S100P and S100A1 at the molecular level. These results have revealed the similarities and the differences between the S100P homodimer and the S100A1/S100P heterodimer.

B-Lymphocytes↗

PubMed2004

[Clinical application of mastoscopic axillary sentinel lymph node biopsy].

OBJECTIVE: To evaluate the technique and significance of mastoscopic axillary sentinel lymph node biopsy. METHODS: Sixty-two patients with breast cancer use methylene blue to test axillary sentinel lymph node. Sentinel lymph node was moved with endoscopy, and endoscopic axillary lymph nod dissection was performed. Pathological examination of sentinel lymph node and axillary lymph node was made with HE. To evaluate detection rate and false negative rate in sentinel lymph node. RESULTS: Among the 62 patients, 61 were confirmed by endoscopic axillary sentinel lymph nod biopsy. Detection rate was 98.4%. Thirty-five cases were no metastasis, 27 cases were metastasis, false negative rate was 0. CONCLUSIONS: Mastoscopic axillary sentinel lymph node biopsy has a high detection rate, good efficiency of cosmetic and lower complications. It has higher sensitivity than traditional axillary lymph nod dissection and provide accurate lymph node stages.

Adult↗

PubMed2004

Comparison of nuclear matrix proteins between gastric cancer and normal gastric tissue.

AIM: To study the alteration of nuclear matrix proteins (NMPs) in gastric cancer. METHODS: The NMPs extracted from 22 cases of gastric cancer and normal gastric tissues were investigated by SDS-PAGE technique and the data were analyzed using Genetools analysis software. RESULTS: Compared with normal gastric tissue, the expression of 30 ku and 28 ku NMPs in gastric cancer decreased significantly (P=0.002, P=0.001, P<0.05). No significant difference was found in the expression of the two NMPs between the various differentiated grades (P=0.947, P=0.356) and clinical stages of gastric cancer (P=0.920, P=0.243, P>0.05). CONCLUSION: The results suggested that the alteration of NMPs in gastric cancer occurred at the early stage of gastric cancer development.

Cell Nucleus↗

PubMed2004

Metallic mesoporous nanocomposites for electrocatalysis.

We describe the fabrication, characterization, and applications of ultrathin, free-standing mesoporous metal membranes uniformly decorated with catalytically active nanoparticles. Platinum-plated nanoporous gold leaf (Pt-NPG) made by confining a plating reaction to occur within the pores of dealloyed silver/gold leaf is 100 nm thick and contains an extremely high, uniform dispersion of 3 nm diameter catalytic particles. This nanostructured composite holds promise as a prototypical member of a new class of fuel cell electrodes, showing good electrocatalytic performance at low platinum loading (less than 0.05 mg cm-2), while also maintaining long-term stability against coarsening and aggregation of catalytic nanoparticles.

Journal Article↗

PubMed2004

Antitumor activity of IFIX, a novel interferon-inducible HIN-200 gene, in breast cancer.

We identified IFIX as a new member of the hematopoietic interferon (IFN)-inducible nuclear protein with the 200-amino-acid repeat (HIN-200) family. Six different alternatively spliced forms of mRNA are transcribed from the IFIX gene, which are predicted to encode six different isoforms of IFIX proteins (IFIXalpha1, alpha2, beta1, beta2, gamma1, and gamma2). The IFIX proteins are primarily localized in the nucleus. They share a common N-terminal region that contains a predicted pyrin domain and a putative nuclear localization signal. Unlike IFIXalpha and IFIXbeta, IFIXgamma isoforms do not have the 200-amino-acid signature motif. Interestingly, the expression of IFIX was reduced in most human breast tumors and breast cancer cell lines. Expression of IFIXalpha1, the longest isoform of IFIX, in human breast cancer cell lines reduced their anchorage-dependent and -independent growth in vitro and tumorigenicity in nude mice. Moreover, a liposome-mediated IFIXalpha1 gene transfer suppressed the growth of already-formed tumors in a breast cancer xenograft model. IFIXalpha1 appears to suppress the growth of breast cancer cells in a pRB- and p53-independent manner by increasing the expression of the cyclin-dependent kinase inhibitor p21(CIP1), which leads to the reduction of the kinase activity of both Cdk2 and p34(Cdc2). Together, our results show that IFIXalpha1 possesses a tumor-suppressor activity and suggest IFIXalpha1 may be used as a therapeutic agent in cancer treatment.

Alternative Splicing↗

PubMed2004

3D structure of human FK506-binding protein 52: implications for the assembly of the glucocorticoid receptor/Hsp90/immunophilin heterocomplex.

FK506-binding protein 52 (FKBP52), which binds FK506 and possesses peptidylprolyl isomerase activity, is an important immunophilin involved in the heterocomplex of steroid receptors with heat-shock protein 90. Here we report the crystal structures of two overlapped fragments [N(1-260) and C(145-459)] of FKBP52 and the complex with a C-terminal pentapeptide from heat-shock protein 90. Based on the structures of these two overlapped fragments, the complete putative structure of FKBP52 can be defined. The structure of FKBP52 is composed of two consecutive FKBP domains, a tetratricopeptide repeat domain and a short helical domain beyond the final tetratricopeptide repeat motif. Key structural differences between FKBP52 and FKBP51, including the relative orientations of the four domains and some important residue substitutions, could account for the differential functions of FKBPs.

Amino Acid Sequence↗

PubMed2004

Determination of paeoniflorin in rat hippocampus by high-performance liquid chromatography after intravenous administration of Paeoniae Radix extract.

A rapid and simple high-performance liquid chromatographic (HPLC) assay for the determination of paeoniflorin in rat hippocampus was developed in this study. The chromatographic analysis was carried out using reversed-phase isocratic elution with a Zorbax SB-C(18) column, a mobile phase of methanol-water (32:68, v/v), and detection by ultraviolet (UV) absorption at 233 nm. The lower limits of quantitation (LLQ) were 1 microg/ml for paeoniflorin. The calibration curve for paeoniflorin was linear (r = 0.9999) over the concentration range of 1-50 microg/ml. The coefficients of variation of intra- and inter-day assays were 7.00, 0.58, 1.46% and 5.48, 1.79, 1.70% at concentrations of 1, 10, 50 microg/ml, respectively. The recoveries of paeoniflorin from rat hippocampus were 98.28 +/- 2.14, 98.96 +/- 1.48, and 95.34 +/- 0.92 at concentrations of 1, 10 and 50 microg/ml, respectively. Stability studies showed that paeoniflorin was stable at temperatures of 2-8 degrees C in methanol for at least 20 days. The method was applied to determine the time course of paeoniflorin in rat hippocampus, following the administration of a 60 mg/kg i.v. dose of paeoniflorin in Paeoniae Radix extract to a male Wistar rat.

Animals↗

PubMed2004

Electron ionization mass spectrometric study of 1,4-dihydro-4-substituted 2,6-dimethyl-3,5-bis(alkoxycarbonyl)pyridines.

Using the accurate masses obtained from a time-of-flight instrument and the tandem mass spectrometric (MS/MS) data from an ion trap instrument, electron ionization mass spectra of a series of 1,4-dihydro-4-substituted 2,6-dimethyl-3,5-bis(alkoxycarbonyl)pyridines are reported and rationalized. Two sets of fragmentation pathways are proposed. One involves the formation of fragment ions containing the 1,4-dihydropyridine structure, and the other of ions containing a pyridine ring.

Molecular Structure↗

PubMed2004

Effects of cerebral ischemia-reperfusion on pharmacokinetic fate of paeoniflorin after intravenous administration of Paeoniae Radix extract in rats.

The objective of the present study was to investigate the effects of cerebral ischemia-reperfusion on pharmacokinetics of paeoniflorin after intravenous administration of Paeoniae Radix extract (PRE) in rats. The cerebral ischemia-reperfusion rats were induced by occluding the bilateral carotid arteries of normal rats for 2 h, followed by reperfusion. The resultant animals were immediately administrated by PRE (at a dose of 60 mg/kg of paeoniflorin) via the femoral vein, whilst the same dose was injected to the normal rats. Plasma samples were collected at different time to construct pharmacokinetic profiles by plotting drug concentration versus time. Quantification of paeoniflorin in rat plasma was achieved by using a simple and rapid high-performance liquid chromatographic method. In normal rats, the major parameters of distribution half-life (t1/2alpha), elimination half-life (t1/2beta), area under the plasma concentration-time (AUC), mean retention time (MRT), and clearance (CL), estimated by an open two-compartmental model, were 0.69, 18.77 min, 5338.71 (microg min)/ml, 18.13 min and 0.0162 mg/(kg min), respectively. However, in ischemia-reperfusion rats, the corresponding parameters were 2.04, 24.51 min, 9626.00 (microg min)/ml, 29.75 min and 0.0071 mg/(kg min), respectively. The results showed that ischemia- reperfusion significantly increased AUC values, decreased CL values, and prolonged the terminal half-life of paeoniflorin. These findings suggest that the injuries of ischemia-reperfusion could play an important role in pharmacokinetic process of paeoniflorin.

Animals↗

PubMed2004

The antidepressant effect of ethanol extract of radix puerariae in mice exposed to cerebral ischemia reperfusion.

In our pilot study, the depressive-like behaviors of mice exposed to cerebral ischemia reperfusion (CIR) were observed and the antidepressant effects of radix puerariae (RP; root of the Pueraria plant) extract in CIR mice were assessed because it was speculated that the neuronal damage caused by CIR played an important role in the development of poststroke depression (a common and severe complication after stroke) and the RP extract was reported to exhibit effect of neuronal protection from cerebral ischemia damage. Our studies above indicated that the RP extract markedly shortened the increased immobility time induced by CIR of male mice in the forced swimming test (FST) and tail suspension test (TST), indicating a possible antidepressant activity. Thus, the aim of the present study was to confirm the putative antidepressant effect of RP extract (75, 150, and 300 mg/kg, administered orally 24 h after the CIR) on reserpine-induced symptoms. To get further insight into the mode of antidepressant action of RP extract, biochemical examination was conducted concomitantly to examine possible involvement of the brain monoamine systems in the behavioral syndromes observed. In CIR mice, pronounced low levels of norepinephrine (NE) and 4-dihydroxyphenylacetic acid (DOPAC, a metabolite of dopamine) in the hippocampus or striatum were detected, which were reversed by RP extract, whereas no significant change of serotonin (5-HT) was detected in either CIR or RP extract-treated mice. The data suggested that the disturbance of NE and DA systems in hippocampus and striatum played more important roles in the development of depressive-like behavior of CIR mice than 5-HT system did, and RP extract ameliorated the abnormal symptoms caused by CIR, which may throw new lights on the treatment of poststroke depression.

Animals↗

PubMed2004

Bioactive compounds from the seeds of Punica granatum (pomegranate).

Two new compounds, coniferyl 9-O-[beta-D-apiofuranosyl(1-->6)]-O-beta-D-glucopyranoside (1) and sinapyl 9-O-[beta-d-apiofuranosyl(1-->6)]-O-beta-D-glucopyranoside (2), were isolated from the seeds of Punica granatum (pomegranate), together with five known compounds, 3,3'-di-O-methylellagic acid (3), 3,3',4'-tri-O-methylellagic acid (4), phenethyl rutinoside, icariside D1, and daucosterol. The structures of 1 and 2 were elucidated by spectroscopic data analysis. Compounds 1-4 exhibited antioxidant activity, which was evaluated by measurement of low-density lipoprotein (LDL) susceptibility to oxidation and by determination in vitro of malondialdehyde (MDA) levels in the rat brain.

Animals↗

PubMed2004

A new stilbenoid from Arundina graminifolia.

A chemical investigation of the Orchidaceae Arundina gramnifolia has led to the isolation of a novel stilbenoid, named arundinan (1). The structure of 1 has been elucidated as 2-(p-hydroxybenzyl)-3-hydroxy-5-methoxybibenzyl on the basis of physical and chemical evidence and spectral analysis.

Humans↗

PubMed2004

A multimodal, multidimensional atlas of the C57BL/6J mouse brain.

Strains of mice, through breeding or the disruption of normal genetic pathways, are widely used to model human diseases. Atlases are an invaluable aid in understanding the impact of such manipulations by providing a standard for comparison. We have developed a digital atlas of the adult C57BL/6J mouse brain as a comprehensive framework for storing and accessing the myriad types of information about the mouse brain. Our implementation was constructed using several different imaging techniques: magnetic resonance microscopy, blockface imaging, classical histology and immunohistochemistry. Along with raw and annotated images, it contains database management systems and a set of tools for comparing information from different techniques. The framework allows facile correlation of results from different animals, investigators or laboratories by establishing a canonical representation of the mouse brain and providing the tools for the insertion of independent data into the same space as the atlas. This tool will aid in managing the increasingly complex and voluminous amounts of information about the mammalian brain. It provides a framework that encompasses genetic information in the context of anatomical imaging and holds tremendous promise for producing new insights into the relationship between genotype and phenotype. We describe a suite of tools that enables the independent entry of other types of data, facile retrieval of information and straightforward display of images. Thus, the atlas becomes a framework for managing complex genetic and epigenetic information about the mouse brain. The atlas and associated tools may be accessed at http://www.loni.ucla.edu/MAP.

Anatomy, Artistic↗

PubMed2004

A new approach to investigate the pharmacokinetics of traditional chinese medicine YL2000.

Much progress has been made in the pharmacology of Traditional Chinese Medicine (TCM). However, the question on how to investigate pharmacokinetics of TCM extract remains. In this study, we selected a new TCM extract YL2000 developed in our laboratory as the research object and investigated both the pharmacokinetics of baicalin and berberine in YL2000 and the pharmacodynamics of YL2000 in febrile rats. The correlation analysis between the time-concentration curves of baicalin and berberine and the time-effect curve of YL2000 was conducted in plasma by statistical methods. The results showed that the time-effect data of anti-pyretic effect of YL2000 had a negative correlation (r = -0.8312, P < 0.1) with the time-concentration data of baicalin in plasma, but had no correlation (r = 0.01368, P > 0.5) with berberine. These data suggested that baicalin could be selected as a marker of anti-pyretic effect, and that YL2000 could be used to treat fevers according to the disposition of baicalin in vivo. In this study, we also proposed that one or more active elements in TCM extracts could be selected to represent the pharmacokinetics of TCM extracts in vivo, combined with the pharmacodynamics of TCM extract.

Analgesics, Non-Narcotic↗