PubMed Health⌕ Search

Biomedical subjects

Yi Ding

Publications and source records attributed to Yi Ding.

At least 37 records · Page 2Linked to original sources
PubMed2006

[The expression and activity of alkaline phosphatase in human periodontal ligament cells with nanometer hydroxyapatite].

OBJECTIVE: To investigate the effect of nanometer hydroxyapatite on the proliferation and the osteogenetic differentiation of periodontal ligament cells (PDLC). METHODS: Nano-hydroxyapatite powders were fabricated with sol-gel method. The fourth passage periodontal ligament cells were cultured with nanometer hydroxyapatite powder (nano-HA), dense hydroxyapatite powder (dense-HA) and only medium as control respectively. On the 5th, 8th day of culture, the osteogenetic differentiation of human periodontal ligament cells was evaluated though alkaline phosphatase (ALP) activity, ALP immunohistochemical stain and ALP positive flow cytometry. RESULTS: There were significant differences among nano-HA group, dense-HA group and control group on the 5th and 8th day of culture. A majority of nano-HA group and dense-HA group cells sample showed positive ALP stain. But the ALP positive stain of nano-HA group cells sample was denser than that of dense-HA group. In FCM, the distribution of ALP positive cells cultured with nanoparticles were significantly more than that of other groups. CONCLUSIONS: The nano-HA, as a calcium phosphate biomaterial, has ability to promote the activity of osteogenetic differentiation for periodontal ligament cells compared with dense-HA.

Alkaline Phosphatase↗
PubMed2006

[Studies on phenolic constituents from leaves of pineapple (Ananas comosus)].

OBJECTIVE: To study the phenolic constituents of the leaves of pineapple. METHOD: Chromatographic methods were used to isolate compounds from the leaves of pineapple and spectroscopic methods were used to identify the structures of the isolated compounds. RESULT: 7 compounds, ananasate (1), 1-O-caffeoylglycerol (2), 1-O-p-coumaroylglycerol (3), caffeic acid (4), p-coumaric acid (5), beta-sitosterol (6) and daucosterol (7), were isolated from the leaves of pineapple. CONCLUSION: 1 was a new compound, and others were obtained from this plant for the first time.

Ananas↗
PubMed2005

Gaultherin, a natural salicylate derivative from Gaultheria yunnanensis: towards a better non-steroidal anti-inflammatory drug.

One of the major factors limiting the use of non-steroidal anti-inflammatory drugs is gastrointestinal toxicity. Gaultherin, 2-[(6-O-beta-D-Xylopyranosyl-beta-D-glucopyranosyl)oxy] benzoic acid methyl ester, a natural salicylate derivative extracted from Gaultheria yunnanensis, has been shown to have analgesic and anti-inflammatory effects and lack gastric ulcerogenic effect compared to aspirin in our primary study. The aim of this study was to investigate the mechanism of action of gaultherin, which may rely on its active metabolite, and the mechanism responsible for the non-ulcerogenic property. The results showed that gaultherin (200 mg/kg) significantly inhibited the abdominal contractions in the acetic acid-induced writhing test in mice. The anti-inflammatory effect of gaultherin was demonstrated in the croton oil-induced ear edema model in mice. The results showed that gaultherin and equimolar dose of aspirin produced comparable inhibitory effects. The study of the metabolism characters of gaultherin in mice and rats indicated that gaultherin could be metabolically converted to salicylate, which produced the pharmacological effects, and provided effective concentrations for an extended period. In vitro metabolism experiment showed that gaultherin was metabolized by beta-glycosidase produced by human intestinal bacteria and esterases in intestine, blood and liver successively to release salicylate finally. The study suggested gaultherin did not cause gastric ulcer for the reason that it released salicylate in intestine slowly, not in stomach and it left the cyclooxygenase-1 unaffected, which was the source of cytoprotective prostaglandins in gastric epithelium.

Abdominal Pain↗
PubMed2005

Study of rice pollen grains by multispectral imaging microscopy.

Cellular images obtained by light microscopy have been analyzed qualitatively, but there is still a lack of quantitative information about the variations in cellular metabolism of selective substances. A new approach using the multispectral imaging microscope (MIM) to observe rice (Oryza sativa L.) pollen grains is reported. A liquid crystal tunable filter device was used for wavelength selection from 400 to 720 nm and a cooled two-dimensional monochrome charge coupled device for image detection. Rice pollen were stained respectively by acetocarmine, Coomassie blue, or iodine potassium-iodine, and then imaged by MIM. The images were processed by the WuDa Image Analysis System 2003 (computer software), and the transmittance spectra for pollen grain images were obtained. The statistical analysis of the transmittance data showed that the macromolecular amount (nucleic acid, protein, starch) of male-sterile line (MSL) pollen grains was less than those of the fertility-maintaining line (FML). For instance there was a significantly lower nucleic acid content in the MSL than in the FML pollen. The results revealed that pollen abortion was directly related to the diminution of intracellular substances for metabolism. Consequently, we have established a quantitative criterion to determine pollen sterility. Comparing the spectra features of the FML with the MSL, we found that certain spectra features can be used to identify various types of abortion pollens and the deficient cytoplasm of male-sterile rice. Our experimental results offer the first quantitative understanding for evaluating cell morphological structure correlated with cellular physiological status.

Image Processing, Computer-Assisted↗
PubMed2005

[Long-term results of combined therapy for primary osteosarcoma in extremities of 189 cases].

OBJECTIVE: To evaluate the survival rates and complications of combined therapy for primary osteosarcoma of the extremities between 1992 and 2001. METHODS: From 1992 to 2002, 189 patients with non-metastatic osteosarcoma were treated. Their average age at diagnosis was 18 years old (ranging from 4 to 39). Tumors were located at distal femurs in 86 patients, proximal femurs in 4, proximal tibia in 52, proximal humors in 19 and other locations in 28. Combined therapy (resection of tumor with chemotherapy) was given 116 patients and non-combined therapy (tumor resection only and unfinished chemotherapy) to 73. In combined therapy group, 90 patients underwent limb salvage surgery, and 26 patients received amputations. In non-combined therapy group, 42 patients underwent limb salvage surgery and 31 patients received amputations. RESULTS: The 5-year-survival rates were 78.5% in the combined therapy group and 35.1% in the non-combined therapy group. Local recurrence rate was 16.6% (15 cases) in limb salvage surgery with combined therapy group (90 cases) and 38.1% (16 cases) in limb salvage surgery with non-combined therapy group (42 cases) (P < 0.007). Metastasis rate was 28.4% (33 cases) in the combined therapy group (116 cases) and 65.7% (48 cases) in the non-combined therapy group (73 cases) (P < 0.000). Functional evaluation showed that the patients who underwent salvage surgery had higher functional scores than those who had an amputation. According to MSTS scoring system (1993), 56 patients (excision alcohol replacement 36 cases, allograft 10 cases and prosthesis 10 cases) were evaluated functional scores. The average scores reached same level (P > 0.5). CONCLUSIONS: (1) In this study, the 5-year-survival rate in the combined therapy is improved. The treatment for the patients with metastasis in lung is very difficult for improvement of the 5-year-survival rate. (2) The local recurrence is related the surgical margin. The adequate surgical margin is very important for the limb salvage. (3) The combined therapy is very essential for improving survival rate.

Adolescent↗
PubMed2005

Control of homeostatic proliferation by regulatory T cells.

Homeostatic proliferation of T cells leads to the generation of effector/memory cells, which have the potential to cause harm to the host. The role of Tregs in the control of homeostatic proliferation is unclear. In this study we utilized mice that either harbor or lack Tregs as recipients of monoclonal or polyclonal T cells. We observed that while Tregs completely prevented cell division of T cells displaying low affinity for self ligands, they had a less marked, albeit significant, effect on cell cycle entry of T cells displaying higher affinity. The presence of Tregs resulted in a lower accumulation of T cells, enhanced apoptosis, and impaired differentiation to a cytokine-producing state. We conclude that Tregs play a major role in the control of homeostatic proliferation.

Animals↗
PubMed2005

Alkaloids from Portulaca oleracea L.

Five alkaloids (oleraceins A, B, C, D and E) were isolated from Portulaca oleracea L., and their structures determined by spectroscopic methods as 5-hydroxy-1-p-coumaric acyl-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside, 5-hydroxy-1-ferulic acyl-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside, 5-hydroxy-1-(p-coumaric acyl-7'-O-beta-D-glucopyranose)-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside, 5-hydroxy-1-(ferulic acyl-7'-O-beta-D-glucopyranose)-2,3-dihydro-1H-indole-2-carboxylic acid-6-O-beta-D-glucopyranoside and 8,9-dihydroxy-1,5,6,10b-tetrahydro-2H-pyrrolo[2,1-a]isoquinolin-3-one, respectively.

Alkaloids↗
PubMed2005

[Allograft replacement in management of giant cell tumor of bone: a report of 77 cases].

OBJECTIVE: To evaluate the functional outcome and the complications of allograft replacement in management of giant cell tumors of bone. METHODS: Seventy-seven patients who underwent bone tumor resection and massive allograft reconstruction of bone defects between 1992 and 2002 were evaluated. The length of the resected part ranged from 5 to 11 centimeters. Fresh-frozen allografts were employed as osteoarticular grafts (n = 47), hemi-condylar (n = 12), massive (n = 14) or allograft-prosthesis composite (n = 4). Most of the lesions located in proximal and distal femur, proximal tibia and humerus. The oncological parameters that were evaluated including survival of the patient, local recurrence, and metastasis. The radiographic parameters included time to union, stability of the joint, fracture of the allograft. Mankin evaluation system was used to assess functional outcome. RESULTS: At a median of 35 months (range from 12 to 135 months) after the operation, 76 of the patients in the study group were free of disease, and one had died of disease. Eleven (14.1%) patients had local recurrence and 12 (15.4%) nonunion. Late complications included 5 (6.4%) fractures of the allograft and 5 (6.4%) infections of the graft. Instability of the joint in the form of subluxation was noted in 5 (6.4%) patients. One extremity were amputated due to local recurrence. On the basis of Mankin functional evaluation, the total satisfied rate was 83.2 percent. Osteoarticular graft got the highest score (91.5%) and hemi-condylar got the lowest (66.6%). Massive grafts and composite were at the middle (ranges from 71.4% to 75%). CONCLUSION: Allografts offer many types of reconstruction for bony defects after tumor resection. The functional results are comparable to other methods of reconstruction, and once incorporated by the host, offer the advantage of longevity. It is also a method with high complication, and decreasing the complications could improve the functional score. Less resection could get better reconstruction and better function, less margin resulted at the same time. The risk of recurrence increases when less surgical margin achieves. The main end-result-influencing factor is local recurrence.

Adolescent↗
PubMed2005

Role of stress-activated MAP kinase P38 in cisplatin- and DTT-induced apoptosis of the esophageal carcinoma cell line Eca109.

AIM: To study the role of P38 kinase in esophageal cancer cell apoptosis induced by genotoxin, cisplatin and the unfolded protein response (UPR) inducer, dithiothreitol (DTT). METHODS: Esophageal carcinoma cell line Eca109 was cultured in RPMI 1640 medium to 70% confluency and treated with either cisplatin, DTT, or cisplatin plus DTT in the presence or absence of P38 inhibitor, SB203580. The untreated cells served as the control. The esophageal carcinoma cell apoptosis was detected by agarose gel DNA ladder analysis and quantified by flow cytometry. The P38 phosphorylation was detected by immunohistochemistry using antibodies specific to phosphorylated P38 protein. RESULTS: (1) Both cisplatin and DTT induced apoptosis in the esophageal cancer cell line Eca109 as shown by DNA ladder formation; (2) As detected by antibodies specific for the phosphorylated P38 protein (p-P38), both cisplatin and DTT treatments activated the stress-activated enzyme, MAP kinase P38. The number of positive cells was about 50% for the treatment groups, comparing to that of 10% for untreated group. DTT treatment, but not cisplatin treatment, induces nuclear localization of p-P38; (3) As measured by flow cytometry, inhibition of P38 activity by SB203580 blocks DTT- and cisplatin-induced apoptosis. The rates for DTT, cisplatin, and DTT plus cisplatin-induced apoptosis were 16.8%, 17.1%, and 21.4%, respectively. Addition of the SB compound during the incubation reduced the apoptotic rate to about 7.6% for all the treatment groups, suggesting that P38 activation is essential for cisplatin- and DTT-induced apoptosis in Eca109 cells. CONCLUSION: (1) Both DTT and cisplatin were able to induce apoptosis in esophageal cancer cell line Eca109; (2) P38 MAP kinase is essential for DTT- and cisplatin-induced apoptosis in Eca109 cells; (3) P38 activation may be the common signaling component relaying the multiple upstream signaling events to the downstream cell death program.

Antineoplastic Agents↗
PubMed2005

Kinetic difference of berberine between hippocampus and plasma in rat after intravenous administration of Coptidis rhizoma extract.

In order to investigate the pharmacokinetics of berberine in Coptidis rhizoma extract in rat hippocampus and plasma, a simple and accurate high-performance liquid chromatography method was employed in this study. Berberine was determined using a Hypersil C(18) column with an isocratic mobile phase of acetonitrile-0.05 M potassium dihydrogen phosphate (containing 0.5% triethylamine, pH 3.0) and with UV detection at 236 nm. The lower limit of quantification for berberine in both hippocampus and plasma was 24 ng/ml, and the lowest concentrations of berberine determined in rat hippocampus and plasma samples were 30.7 ng/ml at 48 h and 38.5 ng/ml at 4 h, respectively. The calibration curve for berberine was linear over the concentration range 24--6000 ng/ml. At this concentration range, the overall recoveries (90.6--94.2%) for berberine were determined and the accuracy of intra- and inter-day assays from rat samples were less than 7% RSD. Following intravenous administration of C. rhizoma extract at a dose of 10.2 mg/kg containing 3 mg/kg berberine, berberine in the plasma eliminated rapidly (t(1/2 beta)=1.13 h). However, berberine in the hippocampus increased rapidly (t(1/2 alpha)=0.215 h), peaked at 3.67 h with a concentration of 272 ng/g, and had a slow elimination rate (t(1/2 beta)=12.0 h), which suggests that berberine could have a direct action on neuron and accumulate in the hippocampus. This study first showed the pharmacokinetic characteristics of berberine in rat hippocampus and the kinetic characteristics of berberine are dissimilar in the hippocampus and plasma.

Animals↗
PubMed2005

Purification, crystallization and preliminary X-ray diffraction analysis of human enolase-phosphatase E1.

Enolase-phosphatase E1 (MASA) is a bifunctional enzyme in the ubiquitous methionine-salvage pathway and catalyzes the continuous reaction of 2,3-diketo-5-methylthio-1-phosphopentane to yield the acireductone metabolite. Recombinant human E1 enzyme has been crystallized using the hanging-drop vapour-diffusion method and diffraction-quality crystals were grown at 291 K using PEG 4000 as precipitant. Diffraction data were collected to 1.7 A resolution from SeMet-derivative crystals at 100 K using synchrotron radiation. The crystals belong to space group P2(1)2(1)2(1), with unit-cell parameters a = 54.02, b = 57.55, c = 87.32 A. The structure was subsequently solved by the multi-wavelength anomalous diffraction (MAD) phasing method.

Crystallization↗
PubMed2005

HPLC method for the determination and pharmacokinetic studies on puerarin in cerebral ischemia reperfusion rat plasma after intravenous administration of puerariae radix isoflavone.

A new HPLC method for the determination of puerarin in cerebral ischemia reperfusion rat plasma is introduced. Puerarin, the principal bioactive component of puerariae radix isoflavone, was extracted from plasma by methanol. The HPLC separation was then performed on a reversed-phase C18 column using water-acetonitrile (89:11, v/v) as eluting solvent system, and UV detection at 252 nm to measure the analyte with a limit of quantitation about 9.44 ng ml(-1). The calibration curve for puerarin was linear (r=0.9998) in the concentration range of 9.44-1208.00 ng ml(-1), both intra- and inter-day precision of the puerarin were determined and their coefficient of variation did not exceed 10%. The validated method has been successfully applied for pharmacokinetic studies of puerarin from rat plasma after intravenous administration of puerariae radix isoflavone. Another novel finding of this study was that the elimination rate of puerarin was significantly slower in the cerebral ischemia reperfusion rat than in the normal rat, judging by the pharmacokinetic parameters obtained. Since puerariae radix isoflavone was mainly administrated to the patients suffering from cerebralvascular diseases, the pharmacokinetic studies performed on the pathological animal models were suitable references for clinical application.

Animals↗
PubMed2005

Study of 2-(2-pyridyl)benzothiazoline as a novel fluorescent probe for the identification of superoxide anion radicals and the determination of superoxide dismutase activity in scallion genus foods.

This paper presents a novel spectrofluorometric method using the novel fluorescent probe 2-(2-pyridyl)benzothiazoline for the determination of superoxide dismutase (SOD) activity. The fluorescent probe was synthesized in house and fully characterized by elemental analysis and by IR and (1)H NMR spectra. It could specially identify and trap superoxide anion radicals (O2(.-)), and then was oxidized by O2(.-) to form a strong fluorescence product. On the basis of this reaction, the spectrofluorometric method was proposed and successfully used to determine SOD activity. The proposed method has a better selectivity in the determination of reactive oxygen species, because the probe can be oxidized to afford a highly fluorescent product only by O2(.-) excluding hydrogen peroxide and hydroxyl radical. As a kind of simple, rapid, precise, and sensitive technique, it could avoid the errors caused by detection time and was applied to the measurement of SOD activity in scallion genus foods with satisfactory results.

Allium↗
PubMed2005

[The anatomical characteristics and its applied significance of laparoscopic rectal surgery].

OBJECTIVE: To realize the anatomical characteristics of laparoscopic rectum surgery and its clinical significance. METHODS: 117 cases with benign and malignant diseases of rectum were operated by laparoscopic methods. The anatomy closely related with operation was analyzed. RESULTS: The median operative time were 144 min. 4 cases were converted to open operations, so the converted rate was 1.7%. The blood loss in operation was rather little with an average of 126 ml. No instant or delayed injury of ureters, large bleeding in front of sacrum and other operation-related severe complications happened intra- and after operation. Dissecting only in one case disrupted the anterior-left wall of rectum. CONCLUSION: Laparoscopic rectal surgery is clinically feasible. Mastering the anatomical characteristics of laparoscopic rectum surgery can make us reduce the operative mistakes and complications.

Adolescent↗
PubMed2005

A chromatographic method for baicalin quantification in rat thalamus.

A rapid reversed-phase high-performance liquid chromatographic (rp-HPLC) assay for the determination of baicalin in rat thalamus was developed. This was carried out on a Hypersil -C(18) column using 4-nitro-benzoic acid as the internal standard with a mobile phase of methanol-water-H(3)PO(4) (45:55:0.2, v/v/v). Detection was by UV at 277 nm. The calibration curve for baicalin was linear (r=0.9992) over the concentration range of 0.05--4.0 microg/mL and the limit of detection was 10 ng/mL. The coefficients of variation of intra- and inter-day assays were 2.64, 5.19 and 3.19% and 3.46, 6.21 and 5.58% at concentrations of 0.5, 1.0 and 3.0 microg/mL, respectively. The recoveries of baicalin from rat thalamus were 85.4+/- 5.62, 90.7+/- 2.43 and 89.1+/- 4.75% at concentrations of 0.5, 1.0 and 3.0 microg/mL, respectively. The method was applied to determine the time course of baicalin in rat thalamus, following a single dosage of intravenous administration of Scutellariae radix extract at 90 mg/kg of baicalin to male Wistar rats.

Animals↗
PubMed2005

Direct asymmetric aldol reactions catalyzed by (4R)-4-(beta-Naphthalenyl)methoxy-(S)-proline.

A novel proline derivative, (4R)-4-(beta-Naphthalenyl)methoxy-(S)-proline, was conveniently prepared from the naturally occurring (4S)-hydroxy-(S)-proline; 5 mol % of this compound efficiently catalyzes the asymmetric aldol reactions of various benzaldehydes with acetone in excess of acetone as the solvent, giving the aldol adducts in good yields with ee up to 89.8%.

Acetone↗