Conversion from tridimensional surface to a plane for measuring expanded skin area with computer aid.
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Adult↗
Biomedical subjects
G Sun
Publications and source records attributed to G Sun.
Naturally occurring analogs of lysophosphatidic acid elicit different cellular responses through selective activation of multiple receptor subtypes.
Lysophosphatidic acid (LPA), plasmalogen-glycerophosphate (alkenyl-GP) and, cyclic-phosphatidic acid (cyclic-PA) are naturally occurring phospholipid growth factors (PLGFs). PLGFs elicit diverse biological effects via the activation of G protein-coupled receptors in a variety of cell types. In NIH3T3 fibroblasts, LPA and alkenyl-GP both induced proliferation, whereas cyclic-PA was antiproliferative. LPA and alkenyl-GP decreased cAMP in a pertussis toxin-sensitive manner, whereas cyclic-PA caused cAMP to increase. LPA and alkenyl-GP both stimulated the activity of the mitogen-actived protein kinases extracellular signal regulated kinases 1 and 2 and c-Jun NH2-terminal kinase, whereas cyclic-PA did not. All three PLGFs induced the formation of stress fibers in NIH3T3 fibroblasts. To determine whether these lipids activated the same or different receptors, heterologous desensitization patterns were established among the three PLGFs by monitoring changes in intracellular Ca2+ in NIH3T3 fibroblasts. LPA cross-desensitized both the alkenyl-GP and cyclic-PA responses. Alkenyl-GP cross-desensitized the cyclic-PA response, but only partially desensitized the LPA response. Cyclic-PA only partially desensitized both the alkenyl-GP and LPA responses. We propose that pharmacologically distinct subsets of PLGF receptors exist that distinguish between cyclic-PA and alkenyl-GP, but are all activated by LPA. We provide evidence that the PSP24 receptor is selective for LPA and not activated by the other two PLGFs. RT-PCR and Northern blot analysis indicate the co-expression of mRNAs encoding the EDG-2, EDG-4, and PSP24 receptors in a variety of cell lines and tissues. However, the lack of mRNA expression for these three receptors in the LPA-responsive Rat-1 and Sp2-O-Ag14 cells suggests that a number of PLGF receptor subtypes remain unidentified.
3T3 Cells↗
Estrogen-induced retinoic acid receptor alpha 1 gene expression: role of estrogen receptor-Sp1 complex.
Retinoic acid receptor alpha 1 (RAR alpha 1) gene expression is induced by 17 beta-estradiol (E2) in estrogen receptor (ER)-positive breast cancer cells, and the -100 to -49 region of the RAR alpha 1 gene promoter was previously shown to be required for E2-responsiveness. This region of the RAR alpha 1 promoter was further analyzed using the following oligonucleotides: -100 to -49 (RAR4); -79 to -56 (RAR3); -79 to -49 (RAR2); -100 to -58 (RAR1); and their derived promoter reporter constructs (pRAR4, pRAR3, pRAR2, and pRAR1). In transient transfection studies in MCF-7 human breast cancer cells, pRAR2 and pRAR1 were E2-responsive; both of the RAR alpha 1 gene promoter inserts contained two GC-rich sites and bound Sp1 protein in gel mobility shift assays. Using wild-type [32P]RAR2 and oligonucleotides mutated in one or both GC-rich sites, it was shown that ER enhanced Sp1 binding to both sites, but a ternary ER-Sp1-DNA complex was not observed in gel mobility shift assays. In transient transfection assays, each of the GC-rich motifs were sufficient for E2-induced transactivation. In ER-negative MDA-MB-231 cells transiently transfected with pRAR2, E2 responsiveness was observed only in cells cotransfected with wild-type ER or 11C-ER containing a deletion of the DNA-binding domain but not with ER variants that express activation function-1 (AF-1) or AF-2. Using a similar approach, it was shown that the GC-rich sites in RAR1 were also sufficient for ER activation. These results demonstrate that interaction of a transcriptionally active ER/Sp1 complex with GC-rich motifs is required for hormone inducibility of the downstream region of the RAR alpha 1 gene promoter.
Adenocarcinoma↗
[Epidemiological analysis on inpatients with epidemic encephalitis B at No. 1 Hospital of Lian Yungang from 1988-1996].
To study the morbidity and mortality of inpatients with epidemic encephalitis B (EEB) admitted to No. 1 hospital of Lian Yungang city from 1988-1996, 107 inpatients with EEB in the pediatrics department the hospital were analyzed epidemiologically. Results showed that 107 children with EEB had a proportion of 0.65% to all children admitted in the pediatrics department during that 9 years including 98 cases from the countryside and 9 cases from cities. The ratio was 10.8/1.0 when comparing countryside to city. 87 inpatients (81.3%) of EEB children were below 4 year of age consisting. Most patients were infected in late July or early August in 1990 and 1992 with number of 55 out of 107 (51.4%) that consisted 1.56% and 1.53% of the inpatients in pediatrics those years. It was concluded that EEB had a strict seasonal feature. By comparing data from the first 4 years with the latter 5 years, we noticed that the incidence of the latter had a considerable decrease with more milder cases. The morbidity and mortality of the whole city also appeared a decreasing tendency.
Child↗
[An epidemiologic analysis of brucellosis in Liaoning province].
In order to understand the increasing incidence rate of Brucellosis, the relationship between the epidemic trend and physical conditions of humans, data regarding Brucellosis in Liaoning province, in 1990-1996 was analysed. Results showed that the major cause which led to the Brucellosis recurrence was the importation of sheep named short-tail cold-resistant. The distribution of disease was widely spread. However, most endemic foci were being expanded. The spots in Tieling and Fushun area were merged and became one endemic area. Brucellosis maily involved in the farmer's family that raise sheep while pregnancy make women at reprodactive age susceptible to the disease. The incidence rate in city and rural areas were significantly different despite that they had the same environment that bacteria-carrier sheep were raised.
Animals↗
T-lymphocyte chemotaxis to IL-8 in patients with psoriasis in vitro.
OBJECTIVE: The critical role of infiltrating T cells in the pathogenesis of psoriasis is now well established. In order to determine whether circulating T cells from patients with psoriasis were also involved in the disease process, the authors investigated the biological behavior as studied by chemotactic activity of T cells in patients with psoriasis. METHODS: A 48 microchemotaxis chamber was employed to determine T-cell chemotaxis activity. In addition, the expression of T cell activation markers such as HLA-DR and interleukin 2 receptor were analysed with fluorescence activated cell sorting technique and serum IL-8 level was measured with ELISA methods. Forty-five patients with psoriasis (23 patients with severe psoriasis and 22 with mild psoriasis) and 21 patients with atopic dermatitis were investigated. For comparison, T-lymphocytes from 20 healthy controls were tested equally. RESULTS: T-cell chemotactic responses were significantly decreased in patients with severe psoriasis and atopic dermatitis as compared to healthy controls. Increased expression of activation markers such as HLA-DR and interleukin 2 receptor were demonstrated in circulating T cells from psoriatic patients and atopic dermatitis patients in comparison to healthy controls. Serum IL-8 level was significantly increased in patients with psoriasis and atopic dermatitis. CONCLUSIONS: Circulating T cells in patients with severe psoriasis show abnormal in vitro chemotactic response to IL-8. Furthermore, the in vivo activation state of T lymphocytes in these patients and increased level of serum IL-8 seemed to be associated to their decreased in vitro T-cell chemotactic responses.
Chemotaxis, Leukocyte↗
[Techniques in fetal rabbit surgery].
OBJECTIVE: Experimental fetal surgery has been a popular way to study growth and development and wound healing. The rabbit continues to be a reasonable animal model. The key to success of the experiment lies in keeping the survival rate of the operated animal above 80 percent. In this paper a simple experimental method for fetus surgery in rabbits is described. METHODS: Intravenous thiopental sodium is used for general anesthesia. Surgery is performed inside the uterus through hysterotomy or with the caudal part of the fetus out of the uterus. Amniotic fluid is restituted by instillation of warm saline at 37 degrees C. Special care is taken to suture the amnion. RESULTS: Using these techniques carefully, we have had 90 percent of success in fetal surgery experiment. CONCLUSION: A technically simple procedure has been developed for fetal rabbit surgery.
Animals↗
[Repair of large and complicated defect with multiple expanders].
OBJECTIVE: A method is introduced to obtain good aesthetic and functional results in repairing complicated defects on the face and neck, or total skin defects of the upper limb. METHODS: Two to four expanders are implanted in different areas where the color and texture of skin are similar to that of the defects, expanded simultaneously. During the second operation, several flaps corresponding to the defect areas are created and employed in one procedure. RESULTS: Six patients of 4-41 years old were treated with this technique. All of them have been followed up for 12-18 months with satisfactory results. CONCLUSION: Carefully planned, this maneuver shows better effects than the conventional method in repairing the skin defects of face, neck and upper limb.
Adolescent↗
[Comparative study on biological characteristics and ultrastructure of the fibroblasts derived from normal skin, hypertrophic scar and keloidin in vitro culture].
OBJECTIVE: This study was to investigate the in vitro cultivation, biological characteristics and ultrastructure of the fibroblasts derived from normal skin, hypertrophic scar and keloid, to elucidate the value of their application. METHOD: A comparative study was performed on cell proliferation, cell morphology, cytogenetic feature and cell ultrastructure of fibroblasts from normal skin, hypertrophic scar and keloid by means of the technique of in vitro culture. RESULT: The results indicated that the fibroblasts isolated from normal skin, hypertrophic scar and keloid exhibited similar morphology and growth rates. The cytogenetic feature and cell ultrastructure were also alike. CONCLUSION: According to our study and that of others, we conclude that it is entirely feasible to establish an in vitro culture model of fibroblasts from normal skin for investigation, prevention and treatment of scars.
Adolescent↗
[A study of the adenosine deaminase polymorphism in a Chinese Han population by the PCR method].
The study of genetic polymorphism of adenosine deaminase (ADA) has not been reported in China and abroad. The target DNA was amplified by PCR. The amplified product was then digested with Pst I, and run on a 9% polyacrylamide gel electrophoresis and followed by AgNO3 staining. ADA polymorphism, was determined in 80 unrelated individuals Chinese Han polulation. Five alleles and 14 genotypes were detected. The gene frequencies were ADA * 10 = 0.15625, ADA * 11 = 0.31875, ADA * 12 = 0.23750, ADA * 13 = 0.23125 and ADA * 14 = 0.05625 respectively. The heterozygosity was 0.8 and the discrimination power (DP) was 0.89. The distribution of observed genotypes frequencies was in good agreement with the Hardy-Weinberg law. The study of three families demonstrated that this locus was inherited according to Mendelian law. The technique is quite simple, fast, extremely sensitive, and it does not require the use of radioisotopes. This new method may be used for the forensic identification and paternity testing.
Adenosine Deaminase↗
[Study on effects of new retinoids in combination with IFN-gamma on proliferation and differentiation of U937 cell and its mechanism].
OBJECTIVE: To illustrate the effects of new retinoids in combination with IFN-gamma on the proliferation and differentiation of U937 cell and its mechanism. METHOD: Effects of new retinoids R9158, YS904012 in combination with IFN-gamma on the proliferation and differentiation of U937 cells were studied by detecting NBT, expression of CD14, CD68 and c-myc, and cell cycle shift. RESULT: When the U937 cells had been first treated with new retinoid for 24 hours, and then with IFN-gamma, the differentiation activity could be enhanced, the reverse of the use of two agent in chronology displayed much lower synergistical effect. Retinoids could down regulate c-myc expression and shift the cell population from S phase to G0/G1 phase within 24 hours, and the activity of YS904012 was greater than that of other retinoids. CONCLUSION: New retinoids in combination with IFN-gamma synergistically induced U937 differentiation. Retinoids may play an important role in triggering the differentiation.
Cell Division↗
[Cellular biological mechanism of leukocytosis produced by all-trans retinoic acid: a preliminary study].
OBJECTIVE: To investigate the cellular biological mechanism of leukocytosis produced by all-trans retinoic acid (ATRA). METHODS: BALB/C mice were fed by ATRA. The effects of ATRA on BALB/C mice hematopoiesis was studied by 3H-TdR, semi-solid progenitor culture, and CFU-S number. RESULTS: ATRA increased the peripheral blood cells count in vivo. The effect on WBC count was obvious. The peak of the elevation (183% of the control) occurred at the 16th day. Correspondingly, 3H-TdR was increased and CFU-S was enhanced in BM, and the peak of the elevation (190% and 200% of the control, respectively) occurred at the 8th day. The progenitor cell CFU-GM was proliferated and the maximum elevation (215% of control) was observed at the 12th day. CONCLUSION: ATRA could produce leukocytosis in normal BALB/C mice. The effect was possibly related to the proliferation of CFU-GM and CFU-S and to ATRA-induced CSA such as G-CSF in vivo.
Animals↗
[Protein tyrosine kinase (PTK) activities during the induction of apoptosis by arsenic trioxide (As2O3)].
OBJECTIVE: To explore the mechanism of arsenic trioxide (As2O3) induced apoptosis in K562 cell line. METHODS: Immunoprecipitation was used to obtain BCR/ABL and ABL proteins. The activities of PTK and tyrosine phosphorylation were measured by biochemical method and Western blot, respectively. RESULTS: As2O3 reduced the PTK activities of cytosol and membrane proteins and BCR/ABL and ABL proteins. The tyrosine phosphorylation of 180,000 and 125,000 proteins declined. CONCLUSION: As2O3 may interfere the signal transduction of BCR/ABL protein by reducing its PTK activity and induce K562 cell apoptosis.
Apoptosis↗
[Changes of the deformability of neutrophil and the influence of anisodamine on neutrophil deformability during endotoxin-induced acute lung injury in rats].
OBJECTIVE: To explore the mechanisms of change of deformability of polymorphonuclear leukocytes (PMN) and influence of anisodamine on deformability of PMN during endotoxin-induced acute lung injury (ALI) in rat. To explore the role of PMN in ALI. METHOD: The model of ALI in rat was reproduced by intravenous injection of E Coli endotoxin. The deformability of PMN was measured by micropipette aspiration technique. RESULT: The elastic modulus K1 of PMN at the 1st hour (33 +/- 12 Pa), 4th hours (37 +/- 12 Pa, 1 Pa = 0.0075 mmHg) and 6th hours (38 +/- 13 Pa) after injection of E Coli endotoxin are all significantly higher than that in the control group (26 +/- 9 Pa P < 0.01). The viscosity modulus (mu) of PMN at the 4th hours (5 +/- 3 Pa.s) and 6th hours (6 +/- 3 Pa.s) after injection of E Coli endotoxin are all significantly higher than the control group (3.1 +/- 2.6 Pa.s, P < 0.01). The elastic shear modulus (G) of PMN at the 4th hours (54 +/- 20 Pa) and the 6th hours (56 +/- 21 Pa) after injection of E Coli endotoxin are all significantly higher than the control group (47 +/- 17 Pa, P < 0.05). The K1(33 +/- 12 Pa) and mu(4 +/- 3 Pa.s) in anisodamine group are all significantly lower than endotoxin group in the same time phases (P < 0.05). CONCLUSION: The deformability of PMN decrease remarkably during ALI, which will enhance PMN sequestration in lungs, lead to ALI. It may be one of important pathogenic mechanism of ALI. The anisodamine can inhibit the decrease of deformability of PMN effectively and may have some therapeutic effect on ALI.
Animals↗
[11 beta-Hydroxysteroid dehydrogenase].
There are two types of 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD). 11 beta-HSD 1 is an oxoreductase interconverting biologically active cortisol and inactive cortisone. 11 beta-HSD 2 is an exclusive oxidase only converting cortisol to cortisone. It has been recognized that 11 beta-HSD 2 confers the specificity of mineralocorticoid receptor in the kidney and protects the fetus from high levels of maternal glucocorticoids in the placenta. Lack or malfunction of this enzyme could result in the development of apparent mineralocorticoid excess syndrome and intrauterine growth retardation of the fetus. 11 beta-HSD is possibly involved in a number of other physiological and pathological conditions such as stress, hypertension, diabetes mellitus and neurodegenerative disorders. The functions of 11 beta-HSD 1 are not very well understood.
11-beta-Hydroxysteroid Dehydrogenase Type 2↗
The role of CD8+ Th2 lymphocytes in the development of smoking-related lung damage.
There is increasing evidence for the existence of different subsets of CD8+ T lymphocytes in humans, according to their cytokine secretion profile. Resistance or susceptibility to infections and the outcome of some inflammatory processes may depend on the lymphokine profile which predominates. We show one consequence of the switching of a host CD8+ T cell response from the Th1 effector function to the Th2 pattern in relation to the exposure to a common toxicant and its pathogenetic implications. Chronic obstructive bronchitis is a pulmonary disease characterized by airway inflammation with predominance of CD8+ T lymphocytes, mucus hypersecretion, repeated airway infections, and decline in lung function. Though smoking-related, it affects only a portion of smokers. The results of this study, comparing the functional characteristics of CD8+ T cell clones from smokers with the disease, unaffected smokers and healthy individuals, indicate that the smokers who have a predominance of CD8+ T lymphocytes of the Th2 phenotype may be predisposed to develop more severe smoking-induced lung damage, with chronic airway inflammation, repeated infections and persistent airflow obstruction.
Adult↗
Purification and characterization of a neutral, bile salt-independent retinyl ester hydrolase from rat liver microsomes. Relationship To rat carboxylesterase ES-2.
A neutral, bile salt-independent retinyl ester hydrolase (NREH) has been purified from a rat liver microsomal fraction. The purification procedure involved detergent extraction, DEAE-Sepharose ion exchange, Phenyl-Sepharose hydrophobic interaction, Sephadex G-100 and Sephacryl S-200 gel filtration chromatographies, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The isolated enzyme has an apparent molecular mass of approximately 66 kDa under denaturing conditions on SDS-PAGE. Analysis of the amino acid sequences of four peptides isolated after proteolytic digestion revealed that the enzyme is highly homologous with other rat liver carboxylesterases. In particular, the sequences of the four peptides of the NREH (60 amino acids total) were identical to those of a rat carboxylesterase expressed in the liver (Alexson, S. E. H., Finlay, T. H., Hellman, U., Svensson, L. T., Diczfalusy, U., and Eggertsen, G. (1994) J. Biol. Chem. 269, 17118-17124). Antibodies against this enzyme also react with the purified NREH. Purified NREH shows a substrate preference for retinyl palmitate over triolein and did not catalyze the hydrolysis of cholesteryl oleate. With retinyl palmitate as substrate, the enzyme had a pH optimum of 7 and showed apparent saturation kinetics, with half-maximal activity achieved at substrate concentrations (Km) of approximately 70 microM.
Amino Acid Sequence↗
Expression, purification, and initial characterization of human Yes protein tyrosine kinase from a bacterial expression system.
Protein tyrosine kinase Yes is a cellular homolog of v-Yes, the oncogenic protein product of avian sarcoma virus Y73. Yes is a member of the Src family and its activation has been associated with several types of human cancer. Human Yes has not been previously characterized enzymatically. To carry out biochemical characterizations of this enzyme, we expressed it as a fusion protein with glutathione S-transferase in Escherichia coli, to allow purification in a single step. The affinity-purified GST-Yes has a specific activity of 1.3 nmol min-1 mg-1 with polyE4Y as substrate and Km values of 100 microg ml-1 for polyE4Y and 70 microM for ATP-Mg. The enzyme has a preference for magnesium over manganese ion for maximal activity. The divalent metal cation serves two essential functions for the activity of Yes: one as a part of the phosphate-donating substrate ATP-Mg and the other as an essential activator. The enzyme undergoes autophosphorylation without apparent activation. Finally, we show that the enzyme is inactivated by incubation with protein tyrosine kinase Csk in an ATP-Mg-dependent manner, indicating that cellular Yes can be regulated by Csk phosphorylation. These represent the first biochemical characterization of human Yes protein tyrosine kinase.
Adenosine Triphosphate↗