Biomedical subjects

Y Ding

Publications and source records attributed to Y Ding.

At least 145 records · Page 8Linked to original sources

PubMed2000

[Expression of Fas ligand in urogenital malignant cell lines and renal cell carcinoma].

OBJECTIVE: To explore the expression of Fas ligand in urogenital malignant cell lines and renal cell carcinoma. METHODS: With immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR), we detected the expression of Fas ligand (FasL) in 6 urogenital malignant cell lines, bladder carcinoma cell lines (T(24), EJ, BIU-87), renal cell carcinoma cell lines (GRC-1, RCC-949), prostatic carcinoma cell line (PC-3M), and 10 cases of renal cell carcinoma. RESULTS: The expression of FasL was detected in 3 (BIU-87, RCC-949, GRC-1) of the 6 urogenital malignant cell lines with immunocytochemistry, and 4 (BIU-87, RCC-949, GRC-1, PC-3M) of 6 urogenital malignant cell lines with RT-PCR method. No expression of FasL was detected in bladder carcinoma cell lines T(24) and EJ. Eight of 10 renal cell carcinoma tissues positively expressed FasL mRNA. CONCLUSIONS: FasL can express in urogenital malignant cell lines and renal cell carcinoma.

Carcinoma, Renal Cell↗

PubMed2000

[Simultaneous pallidotomy and thalamotomy for Parkinson's disease with intractable tremor].

OBJECTIVE: To evaluate the clinical necessity, outcomes, safety, and indications of contemporary combined pallidotomy and thalamotomy for Parkinson's disease (PD) with intractable tremor. METHODS: The UPDRS data from 20 patients who received simultaneous pallidotomy and thalamotomy were analyzed retrospectively. During the same period, 326 patients were subjected to unilateral pallidotomy. Improvement and complications between the two groups were compared. RESULTS: Contemporary pallidotomy and thalamotomy effectively improved parkinsonian symptoms as did pallidotomy alone. This procedure completely abolished intractable tremor in all 20 patients. No permanent complications occurred. CONCLUSIONS: Contemporary combination of pallidotomy and thalamotomy is effective and safe in treating regular parkinsonian symptoms and intractable tremor.

Adult↗

PubMed2000

[Telangiectatic osteosarcoma: report of 10 cases].

OBJECTIVE: To raise the level of early diagnosis of telangiectatic osteosarcoma (TOS). METHODS: Ten patients with TOS were treated from July 1991 to December 1998. The patients included men 6 and 4 women, aged from 4 to 44 years (average 23.7 years). The lesions were located at the proximal femur (1 patient), distal femur metaphysis (2), femur shaft (1), proximal tibia metaphysis (2), distal tibia (1) and humerus shaft (3). Preoperative pathologic examination showed two cases of TOS by open biopsy(negative by needle biopsy); the rest were found negative (2 patients), metastasis (1), and sarcoma (5) by needle biopsy. Eight patients received preoperative chemotherapy. Operations including limb-salvage (3) and amputation (7) were performed in all patients. All patients accepted postoperative chemotherapy. RESULTS: 10 Follow-up for a mean of 28 months (range 6 - 72 months) showed no local recurrences: disease-free in 4 patients and pulmonary metastasis in, 6, of whom 5 died and 1 is still alive with lung metastasis. CONCLUSION: TOS is often misdiagnosed and needs early diagnosis and correct treatment under the cooperation of clinicians, radiologists and pathologists.

Adolescent↗

PubMed2000

[The expression of sialyl Lewis-X antigen in LoVo, HT29 cell lines of colorectal cancer and its correlation with metastatic potential].

OBJECTIVE: To study the correlation of sialyl Lewis-X (SLeX) antigen expression with the metastatic potential of human colorectal cancer. METHODS: The expression of biosynthetic enzyme of SLeX antigen--alpha1, 3Fuc-T mRNA in various cell lines of colorectal cancer possessed with different metastatic potentials (LoVo and HT(29)) was investigated by in situ hybridization. The expression of SLeX antigen was studied using immunohistochemistry and fluorescence-activated flow cytometry qualitatively and quantitatively. RESULTS: The expression level of alpha1, 3Fuc-T mRNA and SLeX antigen in highly metastatic LoVo cells was high (21.2 +/- 7.7, 32.8 +/- 10.9, P < 0.05), and the expression level was low in HT(29) cells (10.8 +/- 5.2, 21.9 +/- 8.8) which are known possessed with a lower metastatic potential. CONCLUSION: The expression of SLeX antigen is correlated to the metastatic potentiality of human colorectal cancer.

Cell Line, Tumor↗

PubMed2000

[Distribution of IL-1 beta in periodontium of experimental osteoporosis rats during orthodontic tooth movement].

OBJECTIVE: The purpose of this research is to study the expression change of IL-1 beta induced by forces in the periodontium of osteoporosis rats. METHODS: Eighteen SD rats were randomly divided into three groups: the normal controlled, the normal orthodontically controlled and the experimental group of osteoporosis. Six weeks after ovariectomy, the first molars were moved mesially by 50 g force created from elastic-thread for one week in the force loading groups. Then the rats were killed, and the 5 microns-thick mesiodistal sections of maxillary teeth, including the roots and periodontium were made. IL-1 beta were localized immunohistochemically in periodontium, and semiquantitative analysis of cellular-staining intensity was done by microphotometry. RESULTS: The IL-1 beta of periodontal ligament cells without loading force were mildly stained in the controlled group, but the staining intensity increased significantly in the periodontium of orthodontically moved teeth, and it showed more strengthened staining in the periodontium of force-loading teeth in osteoporosis rats. CONCLUSION: The results demonstrate that periodontal ligament cells respond to mechanical force by increased production of IL-1 beta, and this can be enhanced by osteoporosis. IL-1 beta is an important cytokine in the process of orthodontically periodontal remodeling.

Animals↗

PubMed2000

[Image and quantity analysis of blood-gas in rabbit's artery and Na(+)-K(+)-ATPase in their lungs during PE-SWD treated by HFJV].

This study was made to gain an insight into the mechanism of high-frequency jet ventilation(HFJV) treatment for the pulmonary edema after seawater drowning(PE-SWD). PaO2, PaCO2 and oxygen saturation (SaO2) of the rabbit and Na(+)-K(+)-ATPase in the rabbit's lungs in three groups--PE-SWD group(PE-SWD-G), HFJV group (HFJV-G) and control group(CG), were measured and analysed by the blood-gas analyser and computer image system. The results showed that, after 100 minutes' HFJV, the PaO2, SaO2 and the activity of Na(+)-K(+)-ATPase in the lung capillary endothelial cells in HFJV-G were significantly higher than those in PE-SWD-G(P < 0.01 or P < 0.05). Three parameters of Na(+)-K(+)-TAPase(G1, D1 and D2) in HFJV-G almost returned to their values in CG. The authors suggest that the increase of PaO2 and SaO2 in the rabbit's artery blood in HFJV-G is closely related to the rehabilitation of Na(+)-K(+)-ATPase activity in the lungs after HFJV. The mechanism of successful HFJV treatment for PE-SWD is that HFJV can better correct hypoxemia and improve the rehabilitation of Na(+)-K(+)-ATPase activity in the rabbit's lungs.

Animals↗

PubMed2000

[Study on the mechanism of pulmonary edema after seawater drowning in rabbit].

To study the mechanism of pulmonary edema after seawater drowning (PE-SWD), the indexes of blood-gas and acid-base in rabbits artery blood were measured by the blood-gas analyser. The activity of Na(+)-K(+)-ATPase, cytochrome oxidase(CYTO) and alkaline phospharase(ALP) in the lungs were measured and analysed by computer image system. C-fos mRNA and Fos protein in the lungs were respectively determined by situ hybrioization and immunohisto chemical techniques. The distribution of phospholipid and Ca2+ of rabbits lungs was quantitatively analysed by ultrastructural location method. The results showed that, five parameters of PaO2, oxygen saturation(SaO2), pH, actual bicarbonite(AB) and base excess(BE) and the activity of Na(+)-K(+)-ATPase and CYTO decreased remarkably in PE-SWD. Both c-fos mRNA and Fos protein expression in pulmonary epithelial cells in PE-SWD were significantly elevated compared with the normal controls(P < 0.01). The phospholipids products in the pulmonary alveolar type II epithelial cells were decreased, however, the Ca2+ precipitate pellets inside the lung capillary endothelial cells and the pulmonary alveolar type I and II epithelial cells increased obviously. The arthors suggest that the injuny action of the seawater, hypoxia and metabolic acidosis may be the mian three mechanisms of the pulmonary edema induced seawater drowning. The lowering activity of Na(+)-K(+)-ATPase and CYTO in the lungs and calcium overload in the cells are not only evil consequence resulted from above three factors, but also the importent causes leading to the worse of PE-SWD. The transmiting line of Ca(2+)-fos may be also a key link to bring about the worse of PE-SWD.

Acidosis↗

PubMed2000

[The lamina papyracea fracture reduction under nasal endoscope].

OBJECTIVE: To evaluate the clinical results of blow-out laminapapyracea fracture reduction under nasal endoscopy. METHODS: All 6 cases had endophthalmos and blepharophimosis. Four cases also complained of diplopia. The horizontal and coronal CT of orbit showed the lamina papyracea fracture clearly. The degree and range of the lamina papyracea displacement was measured on CT films. The reduction under nasal endoscope was performed with local and topical anesthesia. We selected the Meeserklinger's route of entry. The uncinate process, ethmoidal bulla, and ethmoidal cells were removed successively. Then, with the help of a tonsil dissector, the lamina papyracea was pushed outward and replaced and was supported with iodoform gauze. After 2 to 3 weeks, the gauze was removed. RESULTS: The endophthalmos and diplopia disappeared in all cases. No postoperative complications occurred. With 0.5-2 years follow-up, the degree of the endophthalmos was stable within 2 mm. CONCLUSION: The reduction under nasal endoscope has many advantages such as short route of entry, simple performance, and no facial scar. It is a good operative option to correct the lamina papyracea fracture.

Endoscopy↗

PubMed2000

[Microsatellite instability in urine sediments from patients with transitional cell carcinoma of bladder and its clinical value].

OBJECTIVE: To investigate the expression of microsatellite instability in transitional cell carcinoma of bladder and to detect its diagnostic value. METHODS: Urine samples from 35 patients with transitional cell carcinoma of bladder (TCC) were analyzed by PCR method. 25 patients were followed up to detect microsatellite instability in their urine sediments. RESULTS: Microsatellite changes (including MSI and LOH) were detected in 88.6% of urine sediments (31 of 35 patients). Microsatellite changes were detected in urine sediments of 10 of 12 patients with tumor recurrence, in which the existence of tumor cells in the urine of 3 patients had been correctly predicted before cystoscopic evidence from 3 to 6 months. CONCLUSION Microsatellite analysis of urine sediment may be a novel and potentially clinical tool for the diagnosis and follow-up of bladder cancer patients.

Adult↗

PubMed1999

Molecular cloning and functional characterization of the upstream promoter region of the human p73 gene.

The p73 gene encodes a protein that shares structural and functional homologies with the p53 tumor suppressor protein. To investigate the mechanism of transcriptional regulation of the p73 gene, we isolated a genomic DNA fragment spanning the 5' upstream region of the human p73 gene and characterized the promoter region. Unlike the p53 gene promoter, the human p73 gene promoter contained a putative TATA-box, and did not exhibit any extended homology to the p53 gene. Two CpG islands were located in the 5' upstream region. Transient transfection assays using progressive truncations of the p73 promoter showed that deletion from -119 to +19 relative to exon 1 resulted in a 13- to 20-fold reduction in the p73 promoter activity, suggesting that the elements for basal promoter activity exist in this region, where putative Sp1, AP-2 and Egr-1, 2, 3 sites are located and CpG dinucleotides are especially concentrated.

Base Composition↗

PubMed1999

Structure and function of HNK-1 sulfotransferase. Identification of donor and acceptor binding sites by site-directed mutagenesis.

HNK-1 glycan, sulfo-->3GlcAbeta1-->3Galbeta1-->4GlcNAc-->R, is uniquely enriched in neural cells and natural killer cells and is thought to play important roles in cell-cell interaction. HNK-1 glycan synthesis is dependent on HNK-1 sulfotransferase (HNK-1ST), and cDNAs encoding human and rat HNK-1ST have been recently cloned. HNK-1ST belongs to the sulfotransferase gene family, which shares two homologous sequences in their catalytic domains. In the present study, we have individually mutated amino acid residues in these conserved sequences and determined how such mutations affect the binding to the donor substrate, adenosine 3'-phosphate 5'-phosphosulfate, and an acceptor. Mutations of Lys(128), Arg(189), Asp(190), Pro(191), and Ser(197) to Ala all abolished the enzymatic activity. When Lys(128) and Asp(190) were conservatively mutated to Arg and Glu, respectively, however, the mutated enzymes still maintained residual activity, and both mutant enzymes still bound to adenosine 3',5'-diphosphate-agarose. K128R and D190E mutant enzymes, on the other hand, exhibited reduced affinity to the acceptor as demonstrated by kinetic studies. These findings, together with those on the crystal structure of estrogen sulfotransferase and heparan sulfate N-deacetylase/sulfotransferase, suggest that Lys(128) may be close to the 3-hydroxyl group of beta-glucuronic acid in a HNK-1 acceptor. In contrast, the effect by mutation at Asp(190) may be due to conformational change because this amino acid and Pro(191) reside in a transition of the secondary structure of the enzyme. These results indicate that conserved amino acid residues in HNK-1ST play roles in maintaining a functional conformation and are directly involved in binding to donor and acceptor substrates.

Amino Acid Sequence↗

PubMed1999

Novel mechanism of hypertension revealed by cell-specific targeting of human angiotensinogen in transgenic mice.

We tested the hypothesis that the tissue-specific intrarenal renin-angiotensin system (RAS) can participate in the regulation of blood pressure independently of its endocrine counterpart, by generating two transgenic models that differ in their tissue-specific expression of human angiotensinogen (AGT). Human AGT expression was driven by its endogenous promoter in the systemic model and by the kidney androgen-regulated protein promoter in the kidney-specific model. Using molecular, biochemical, and physiological measurements, we demonstrate that human AGT mRNA and protein are restricted to the kidney in the kidney-specific model. Plasma ANG II was elevated in the systemic model but not in the kidney-specific model. Nevertheless, blood pressure was markedly elevated in both the systemic and kidney-specific transgenic mice. Acute administration of the selective ANG II AT-1 receptor antagonist losartan lowered blood pressure in the systemic model but not in the kidney-specific model. These results provide evidence for the potential importance of the intrarenal RAS in blood pressure regulation by showing that expression of AGT specifically in the kidney leads to chronic hypertension independently of the endocrine RAS.

Angiotensin Receptor Antagonists↗

PubMed1999

A bayesian statistical algorithm for RNA secondary structure prediction.

A Bayesian approach for predicting RNA secondary structure that addresses the following three open issues is described: (1) the need for a representation of the full ensemble of probable structures; (2) the need to specify a fixed set of energy parameters; (3) the desire to make statistical inferences on all variables in the problem. It has recently been shown that Bayesian inference can be employed to relax or eliminate the need to specify the parameters of bioinformatics recursive algorithms and to give a statistical representation of the full ensemble of probable solutions with the incorporation of uncertainty in parameter values. In this paper, we make an initial exploration of these potential advantages of the Bayesian approach. We present a Bayesian algorithm that is based on stacking energy rules but relaxes the need to specify the parameters. The algorithm returns the exact posterior distribution of the number of destabilizing loops, stacking energy matrices, and secondary structures. The algorithm generates statistically representative structures from the full ensemble of probable secondary structures in exact proportion to the posterior probabilities. Once the forward recursions for the algorithm are completed, the backward recursive sampling executes in O(n) time, providing a very efficient approach for generating representative structures. We demonstrate the utility of the Bayesian approach with several tRNA sequences. The potential of the approach for predicting RNA secondary structures and presenting alternative structures is illustrated with applications to the Escherichia coli tRNA(Ala) sequence and the Xenopus laevis oocyte 5S rRNA sequence.

Algorithms↗

PubMed1999

Assessing heterogeneity and correlation of paired failure times with the bivariate frailty model.

We consider bivariate survival times for heterogeneous populations, where heterogeneity induces deviations in an individual's risk of an event as well as associations between survival times. The heterogeneity is characterized by a bivariate frailty model. We measure the heterogeneity effects through deviations associated with hazard functions and an association function defined through the conditional hazard functions: the cross-ratio function proposed by Oakes. We show how the deviation and association measures are determined by the frailty distribution. A Gibbs sampling method is developed for Bayesian inferences on regression coefficients, frailty parameters and the heterogeneity measures. The method is applied to a mental health care data set.

Algorithms↗

PubMed1999

Contig assembly of bacterial artificial chromosome clones through multiplexed fluorescence-labeled fingerprinting.

A rapid multiplexed fingerprinting method has been developed for bacterial artificial chromosome (BAC) contig assembly. Defined subsets of BAC DNA fragments that result from digestion by three paired restriction endonucleases are labeled with unique fluorescent F-ddATP for each subset. Lists of the labeled fragment size are generated by an ABI 377 DNA sequencer and the GeneScan analysis software and then processed by an assembly program, FPC (Fingerprinted Contigs), to produce contig maps. Data obtained from the multiplexed labeling permit detection of smaller overlaps than is observed when data from a single double-digest are analyzed. The method has been tested on 98 BACs from chromosome 22 regions where large-scale sequencing is under way and also through simulation, using randomly generated BAC clones derived from existing DNA sequence data. In each case, contig assembly results demonstrated the advantages of multiplexed fingerprinting.

Chromosomes, Bacterial↗

PubMed1999

Study on the isolation, purification and physicochemical properties of polysaccharides from Indocalamus tesselatus.

Polysaccharides prepared from Chinese traditional medicine "Ruoye" (Indocalamus tesselatus), a kind of bamboo leaves, were studied. Eight crude polysaccharides were isolated from the dried leaves by successive extraction with 85% ethanol (FE), 0.9% sodium chloride (FS), hot water (FI), 1% ammonium oxalate (FII), 5% NaOH (FIII-a, FIII-b) and 20% NaOH (FIV-a, FIV-b). They were decolorized by hydrogen peroxide treatment and the protein was removed with Savag's method. The polysaccharides were precipitated by three volumes of absolute ethanol. After further purification by gel filtration chromatography on a Sephadex G-200 column, these polysaccharides were lyophilized. Their physicochemical properties and structural feature were elucidated by modern analytical technique such as UV, elemental analysis and high performance gel permeation chromatography. From the results of partial hydrolysis, FE and FIII-b have a main chain comprised solely of glucuronic acid and xylose residues, respectively.

Chromatography, Gel↗

PubMed1999

Study of enantioselective interactions between chiral drugs and serum albumin by capillary electrophoresis.

The separation of the enantiomers of three basic drugs, i.e., ofloxacin, propranolol and verapamil, was achieved by affinity capillary electrophoresis (ACE), with human serum albumin (HSA) and bovine serum albumin (BSA) as chiral selectors in phosphate buffer at pH 7.4. Ofloxacin was only separated in the presence of BSA, and verapamil only with HSA, while propranolol was separated with either HSA or BSA. The effects of protein concentration and column wall adsorption on the degree of separation were investigated. Two displacers, ketoprofen and warfarin, respectively, when added to the protein containing buffer, both showed significant effects on the separation behavior. From these data it was argued that verapamil may bind to HSA at both locations known, the warfarin binding site (I) and the ketoprofen binding site (II). While with BSA, binding of ofloxacin may also occur at site I, the preferential binding site for propanolol remains controversial. A drug-drug interaction between propranolol and ketoprofen due to opposite charges was concluded from the increase in migration time in BSA solution. The unbound concentration of verapamil enantiomers in solution in the presence of HSA, as estimated from CD-modified capillary zone electrophoresis, was triggered not only by the HSA concentration but also by the coadditive concentration.

Adsorption↗

PubMed1999

Study of interaction between drug enantiomers and serum albumin by capillary electrophoresis.

The interaction between drugs and human serum albumin (HSA) was investigated by capillary electrophoresis (CE). It involves stereoselectivity, drug displacement and synergism effects. Under protein-drug binding equilibrium, the unbound concentrations of drug enantiomers were measured by frontal analysis (FA). The stereoselectivity of verapamil (VER) binding to HSA was proved by the different free fractions of two enantiomers. In physiological pH (7.4, ionic strength 0.17 phosphate buffer) when 300 microM (+/-) VER were equilibrated with 500 microM HSA, the concentration of unbound S-VER was about 1.7 times its antipode. The binding constants of two enantiomers, K(R-VER) and K(S-VER), were 2670 and 850 M(-1), respectively. However, no obvious stereoselective binding of propranolol (PRO) to HSA was observed. Trimethyl-beta-cyclodextrin (45 mM) was used as a chiral selector in pH 2.5 phosphate buffer. Several drug systems were studied by the method. When ibuprofen (IBU) was added into VER-HSA solution. R-VER was partially displaced while S-VER was not displaced at all. A binding synergism effect between bupivacaine (BUP) and verapamil was observed and further study suggested that verapamil and bupivacaine occupy different binding site of HSA (site II and site III, respectively).

Binding, Competitive↗