Search PubMed⌕ Search

Biomedical subjects

Y Su

Publications and source records attributed to Y Su.

At least 91 records · Page 5Linked to original sources
PubMed1999

Identification and genetic mapping of differentially expressed genes in mice differing at the If1 interferon regulatory locus.

A subtractive cDNA library was used to identify differentially expressed genes in mouse strains that differ at If1, a locus that regulates response to interferon induction by Newcastle Disease Virus infection. Among the isolated clones, sequence analysis identified the ribosomal proteins L37a and S8 as well as cDNAs for thymosine beta4, the QM transcriptional factor, and a novel genetic sequence. Analysis of two multilocus mouse crosses showed that the thymosine beta4 gene, Ptmb4, is present as a single-copy gene that maps to distal Chr X. The L37a, S8, and QM clones are all members of large multilocus families. These five clones were used to determine the map locations for 37 loci, of which 31 had not previously been described. The novel genetic sequence, D3Ppr1, mapped to distal Chr 3 near the position of the If1 locus, suggesting it may be a candidate for this regulatory gene.

Animals↗
PubMed1999

Financial strain, social relations, and psychological distress among older people: a cross-cultural analysis.

OBJECTIVES: This article examines how financial strain and social relations may independently and jointly influence psychological distress among older people in four nations. METHODS: Data from four Western Pacific nations (N = 3,277) are used to test additive and multiplicative models of the relationships between financial strain, social relations, and psychological distress. RESULTS: Financial strain is associated with higher levels of psychological distress in three of the four nations. Interactive models of the effects of financial strain and social relations on distress were uncovered in three of the four nations, but the type of social relation influencing the strain-distress relationship varied. Subjective-health and IADLs were significant predictors of psychological distress in all four nations. DISCUSSION: Findings suggest that although financial strain is quite likely to lead to psychological distress among elders, this can be mitigated, at least in part, by social relationships. Modernization was not associated with higher psychological distress.

Activities of Daily Living↗
PubMed1999

The association between biliary tract cancers and cancers of other sites.

OBJECTIVE: Cancers of the biliary tract, including cancers of the gallbladder and bile duct, generally carry a very poor prognosis. Little is known about their etiology. The pattern of co-occurrence of two cancers may give clues to shared etiological risk factors. We therefore investigated the association of biliary tract cancer with other cancers, especially with estrogen- and tobacco-related cancers. METHODS: We used data from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute. Associations between biliary tract cancer and other cancers were evaluated using the standardized incidence ratio as an estimate of the relative risk of a second primary malignancy. RESULTS: Estrogen-related cancers of the breast and uterine corpus and smoking-related upper aerodigestive tract cancers were not associated with biliary tract cancer. The risk of gallbladder cancer was inversely related to the risk of prostate cancer in men, but positively related to the risk of cervical cancer in women. CONCLUSIONS: This study suggests that smoking and estrogen exposure have minimal roles in the pathogenesis of biliary tract cancer. Our finding of an inverse relationship between prostate cancer and gallbladder cancer requires confirmation by further studies.

Adult↗
PubMed1999

Rapid film-based determination of antibiotic susceptibilities of Mycobacterium tuberculosis strains by using a luciferase reporter phage and the Bronx Box.

Detecting antibiotic resistance in Mycobacterium tuberculosis is becoming increasingly important with the global recognition of drug-resistant strains and their adverse impact on clinical outcomes. Current methods of susceptibility testing are either time-consuming or costly; rapid, reliable, simple, and inexpensive methods would be highly desirable, especially in the developing world where most tuberculosis is found. The luciferase reporter phage is a unique reagent well-suited for this purpose: upon infection with viable mycobacteria, it produces quantifiable light which is not observed in mycobacterial cells treated with active antimicrobials. In this report, we describe a modification of our original assay, which allows detection of the emitted light with a Polaroid film box designated the Bronx Box. The technique has been applied to 25 M. tuberculosis reference and clinical strains, and criteria are presented which allow rapid and simple discrimination among strains susceptible or resistant to isoniazid and rifampin, the major antituberculosis agents.

Antitubercular Agents↗
PubMed1999

Molecular and cellular basis of tissue remodeling during amphibian metamorphosis.

Amphibian metamorphosis involves systematic transformations of various tadpole organs/tissues. Three major types of changes take place during this process. These are remodeling, resorption, and de novo development, all of which appear to involve both cell proliferation and apoptosis (programmed cell death). All metamorphic changes are controlled by thyroid hormone (T3) and are organ-autonomous. Recent studies using primary cell cultures and a stably transformed cell line from tadpole tissues have implicated that T3 induces apoptosis cell-autonomously. This T3-induced, metamorphosis-associated apoptosis is similar to cell death in other animal species and involves similar cell death executioners. Both the activation of these executioners and the pathways leading to cell proliferation and differentiation are believed to be through transcriptional regulation by T3 receptors (TRs). TRs can activate or repress target gene transcription depending upon the presence or absence of T3, respectively. Many direct T3-response genes have been isolated and found to encode a variety of proteins that can affect both intra- and extra-cellular events. The determinations of the identities of these response genes through sequence analyses and studies on their expression profiles during development have provided strong clues toward their roles in metamorphosis. However, future studies using organ and cell culture systems and/or transient or stable transgenic technologies are required to understand how these genes transduce the T3 signal to activate the downstream cell death and proliferation/differentiation pathways.

Amphibians↗
PubMed1999

[Expression of epidermal growth factor receptor in human endometrium, decidua and trophoblast cells].

OBJECTIVE: To study the expression of epidermal growth factor receptor (EGFR) expression in human normal endometrium, decidua and trophoblast cells of early pregnancy, and to explore the effect of EGFR on cell proliferation and development. METHODS: To localize the EGFR expression in glandular and stromal cells of normal endometrium, decidua with immunohistochemical method (ABC), and to analyse the related quantity of EGFR mRNA by RT-PCR method. RESULTS: There were EGFR expression in both normal endometrium and decidua. EGFR protein located on cell membrane, nuclear membrane and in the cytoplasm as well, and located in the neuclear of glandular and stromal cells in decidua. The expression of EGFR in glandular cells was significantly stronger than that in the stroma (P < 0.05), while there was no difference of EGFR expression in the glands during the menstrual cycle (P > 0.05). However, the expression of EGFR in the glands of decidua was significantly higher than that in the proliferative and secretory endometrium (P < 0.05). The intensity of staining in stromal cells listed in order from the strongest was early decidua > secretory endometrium > proliferative endometrium, the differences were significant (P < 0.05). The related quantity of EGFR mRNA expression in proliferative, secretory endometrium, decidua and trophoblasts were: 0.531 +/- 0.061, 0.594 +/- 0.121, 0.732 +/- 0.032, 0.828 +/- 0.034, respectively. There was no difference during the menstrual cycle, but that in the decidua and trophoblasts were significantly higher than that in the proliferative and secretory endometrium (P < 0.05), and that in the trophoblasts was the highest. CONCLUSION: EGFR expression was present in the proliferative and secretory endometrium, decidua and trophoblasts of early pregnancy, and it was significantly higher in the decidua and trophoblasts than that during the menstrual cycle.

Adult↗
PubMed1999

[Experience in the management of severe inhalation injury].

OBJECTIVE: To summarize our clinical experiences in the treatment of severe inhalation injury accompanying extensive burn. METHODS: Retrospective analysis of 30 cases of inhalation injury (1980-1996) was done, the cure rate, mortality, effective treatments and lessons of failure were summarized. RESULTS: As soon as the diagnosis was defined, tracheostomy should be done immediately, followed by oxygen therapy, tracheo-bronchial lavage, aspiration, and clearance of airway secretion. If there was pulmonary edema or severe bronchospasm, cortical hormone was used for a short time, in addition, the patients were encouraged to cough, breathe deeply, and change postures, as well as patted on the back and also positioned to facilitate posture drainage, etc. These measures were effective. In this series, there were thirty cases of severe inhalation injury. Fourteen patients(46.6%) were cured, sixteen patients died(53.3%). The result was basically satisfactory. CONCLUSION: It is possible to increase the cure rate of severe inhalation injury, and the treatment should be carried out conscientiously as early as possible, and great attention should be paid to prevent various complications.

Adolescent↗
PubMed1999

Effect of burn healing liquid on keratinocyte and fibroblast proliferation and on collagen lattice contraction.

OBJECTIVES: To investigate the effect of Burn Healing Liquid (BHL) on the proliferation of keratinocytes and fibroblasts and to explore the potential effect of BHL on fibroblast contraction. METHODS: Human keratinocytes and dermal fibroblasts were cultured in media containing serial dilutions of BHL followed by cell proliferation determination assessed with MTT (3-[4, 5-dimehtylthiazol-2-yl]-2, 5-diphenyl tetrazolium bromide) assay at different time intervals. The in vitro collagen lattice contraction model was utilized for determining the contractility of fibroblasts cultured in BHL containing medium. RESULTS: The 1:10(7) dilution of BHL enhanced the growth of both keratinocytes and fibroblasts whereas the 1:10 dilution increased the growth of keratinocytes only. Collagen lattice contraction was inhibited dose-dependently by BHL and such an inhibition could be reversed by switching BHL containing medium to normal medium containing 10% fetal calf serum. CONCLUSION: BHL enhances the growth of both keratinocytes and fibroblasts and reversibly inhibits the fibroblast contraction in collagen lattice.

Burns↗
PubMed1999

[The isolation and characterization of dentin phosphoprotein from human dentine].

OBJECTIVE: To establish the method of isolation and characterization of dentin phosphoprotein (DPP) from human dentine. METHODS: Dentin powder was placed in dialysis tube after demineralized to completion with 0.6 mol/L HCl, then isolated DPP through DEAE-Sepharose CL6B anion exchange chromatography. Its protein composition, organic phosphorus content, molecular weight and amino acid were analyzed. RESULTS: DPP contained high organic phosphorus, 23.8% of aspartic residue and 19.1% serine residue; their molecular weight were 141, 000, 124, 000, 108, 000 respectively. CONCLUSION: DPP can be extracted from human dentine with 0.6 mol/L HCl demineralization. and DEAE-Sepharose CL6B anion exchange chromatography. It is a group of proteins which have a high content of organic phosphorus and is found to be rich in serine and aspartic acid residues.

Amino Acids↗
PubMed1999

[Effects of different levels of calcium intake on bone of pregnant women].

OBJECTIVE: To research some effects of different levels of calcium intake in the mother's bone mineral density. METHODS: On the basis of insignificantly different among energy and other nutrition intake excepting calcium, 35 volunteers in pregnant 18 weeks healthy women were randomly divided into I. II and III group [calcium intake were (550 +/- 150) mg/d, (900 +/- 150) mg/d and (1,500 +/- 150) mg/d]. The tracked study began from pregnant 20 weeks to postpartum 45 days. All over and different body of BMD (Bone Mineral Density) were assessed by dual-energy X-rays absorptiometry. RESULTS: I group of many location BMD were below that of other groups (P < 0. 01). As compared with the same age women's lumbar spine BMD, I group was only maintained within the rang (85.14 +/- 6.61)%, and osteoporosis in some places of bone were found in some individual. II group was (90.74 +/- 6.53)%. III group was (100.44 +/- 5.19)%. Allover different body's BMD were significantly correlated with the average BMD (r > 0.8, P < 0.1), the most significant correlation was third lumbar spine. Calcium intake of women was positively correlated with different body's BMD (r > 0.5, P < 0.01). CONCLUSION: III group, calcium intake was (30.68 +/- 3.56) mmol/d, pass through period of pregnancy, parturition and short-term breast-feed mother body remain the same BMD, and prevent osteoporosis. Reporting pregnant women calcium nutrition pass through BMD, lumbar spine is good representation.

Absorptiometry, Photon↗
PubMed1999

[The enantiomeric separation of aromatic alcohol amino drugs by thin-layer chromatography].

Two chiral aromatic alcohol amino drugs, Labarol and Bataroc, were resolved by thinlayer chromatography (TLC) on the silica gel GF254 plates (2.5 cm x 10 cm), by using the ammonium-D-10-camphorsulfonate (CSA) as chiral ion-pair interaction agent which was added to the mobile phase in the ammonium form. All developments were carried out at lower temperature (2-4 degrees C, in a refrigerator) in small glass jars of 250 mL volume. These two drugs were not resolved at room temperature (15-30 degrees C). Analytical reagent grade methanol and dichloromethane can be directly used as mobile phase without further drying. The chiral separation occured over a range from 40% to 70% (optimum 67%) dichloromethane in the mobile phase volume ratio and 55% to 80% (optimum 60%) dichloromethane in the mobile phase volume ratio. These separation conditions were easily obtained. This method is relatively inexpensive and attractive.

Amino Alcohols↗
PubMed1999

[Effects of cyclosporin A combined with T4 on collagen IV production, coll alpha 1 (IV) mRNA and TGF beta 1 mRNA expression in cultured human mesangial cells].

OBJECTIVE: To investigate the effects of single cyclosporin A (CsA), tripcholorlide (T4) or both on renal fibrosis. METHODS: Collagen IV concentrations in the supernatants of human mesangial cells (HMCs) in culture were measured by ELISA. Collagen type IV alpha 1 mRNA (Coll alpha 1 IV mRNA) and transforming growth factor beta 1 (TGF beta 1) mRNA expression were tested by RT-PCR. RESULTS: CsA regulated HMC collagen IV production biphysically, i.e., 1.0 microgram/ml CsA increased collagen synthesis while 0.01-0.1 microgram/ml CsA decreased its formation. T4 enhanced collagen IV production in a dose dependent manner. Combination of the two drugs in lower doses could reach the same degree of immunosuppression as a higher dose of CsA did but with less fibrogenesis. Both CsA and T4 up-regulated HMC Coll alpha 1 (IV) mRNA and TGF beta 1 mRNA expression. The degree of Coll alpha 1 (IV) mRNA expression in different groups were in accordance with that of TGF beta 1 mRNA. CONCLUSIONS: Both CsA and T4 regulate extracellular matrix formation which may be mediated by TGF beta 1. Combination of the two drugs in lower dose results in less fibrosis than a higher dose of CsA.

Cells, Cultured↗
PubMed1998

[Identify influential points].

Influential points are the points with excessive influence on result and detected by influential function theta-theta(i). theta-theta(i) is a multidimensional vector. For convenience, people always consider some quantitative function g (theta-theta(i)) to measure the vector theta-theta(i), but how to define g is a difficult problem. This paper proposes a new quantitative diagnostic statistics for identifying influential points for all parametrical statistical analysis. The method is more appropriate than cook's method for regression analysis. In this study an example is used to illustrate the procedure in COX proportional hazard model.

Proportional Hazards Models↗
PubMed1998

A pH-dependent stabilization of an active site loop observed from low and high pH crystal structures of mutant monomeric glycinamide ribonucleotide transformylase at 1.8 to 1.9 A.

A mutation in the dimer interface of Escherichia coli glycinamide ribonucleotide transformylase (GarTfase) disrupts the observed pH-dependent association of the wild-type enzyme, but has no observable effect on the enzyme activity. Here, we assess whether a pH effect on the enzyme's conformation is sufficient by itself to explain the pH-dependence of the GarTfase reaction. A pH-dependent conformational change is observed between two high-resolution crystal structures of the Glu70Ala mutant GarTfase at pH 3.5 (1.8 A) and 7.5 (1.9 A). Residues 110 to 131 in GarTfase undergo a transformation from a disordered loop at pH 3.5, where the enzyme is inactive, to an ordered loop-helix structure at pH 7.5, where the enzyme is active. The ordering of this flexible loop-helix has a direct effect on catalytic residues in the active site, binding of the folate cofactor and shielding of the active site from solvent. A main-chain carbonyl oxygen atom from Tyr115 in the ordered loop forms a hydrogen bond with His108, and thereby provides electronic and structural stabilization of this key active site residue. Kinetic data indicate that the pKa of His108 is in fact raised to 9. 2. The loop movement can be correlated with elevation of the His pKa, but with further stabilization, probably from Asp144, after the binding of folate cofactor. Leu118, also in the loop, becomes positioned near the p-amino benzoic acid binding site, providing additional hydrophobic interactions with the cofactor 10-formyl tetrahydrofolate. Thus, the pH-dependence of the enzyme activity appears to arise from local active site rearrangements and not from differences due to monomer-dimer association.

Binding Sites↗