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Biomedical subjects

S Yu

Publications and source records attributed to S Yu.

At least 163 records · Page 9Linked to original sources
PubMed2000

[Effect of waterlogging on senescence of winter wheat root system at booting stage].

By applying 3 winter wheat cultivars of different water-resistance, the effect of waterlogging at booting stage on the growth and development of root system, 32P absorption and its distribution, and senescence of root system was studied with soil column culture. Waterlogging at booting stage reduced root dry weight, its activity and SOD activity, and increased the relative permeability of plasma membrane and the membrane-lipid preoxidation level(MDA content) of root system. Meanwhile, waterlogging influenced the 32P absorption, transportation and distribution, and consequently, speeded up the senescence of root system.

Absorption↗
PubMed2000

[Mechanisms of bone repairment in periapical diseases: studies on adjusting bone metabolism with calcium hydroxide in vitro].

OBJECTIVE: To provide experiment evidence for clinical practice and for further exploration on mechanism and medicinal control of periapical diseases. METHODS: The culture model of neonatal mouse calvariae which has the similar biological activity to alveolar bone was established in vitro to observe the influence of calcium hydroxide on osteo-activity. RESULTS: The results showed that calcium hydroxide with proper concentration at organ culture level could enhance osteoblast ALP secreting activity, and increased the tendency of bone formation. At the same time, the concentration of inorganic PO4(3-) in culture medium also had significant changes. CONCLUSIONS: The mechanism of calcium hydroxide promoting repairment of bone tissues is not only by providing rich Ca2+ and alkaline environment mineral deposition, but also by stimulating calcification enzyme activity of osteoblast. Meanwhile, increased PO4(3-) concentration might improve the mineralization environment, which causes mineralization easily.

Alkaline Phosphatase↗
PubMed2000

[A quick way in isolation and amplification of mandibular condylar cartilage cell in vitro].

OBJECTIVE: To establish a quick way in acquiring well differentiated mandibular condylar cartilage (MCC) cells with high viability in large scale. METHODS: Japan white rabbit MCC cells were harvested by enzymatic method. They were grown in a modified bioreactor culture system, which contained the cytodex-3 micro-carriers in the culture medium. Kinetic growth of MCC cells on DEAE-dextran micro-carrier was observed under phase contrast microscope and environmental scanning microscope respectively. RESULTS: MCC cells attached rapidly to the surface of micro-carriers, but their spreading was slow. A quick growth of these cells was observed when they fully spread onto the micro-carrier. The number of MCC cells increased 16.2 times compared with that of plating. CONCLUSIONS: Micro-carrier culture of MCC cells can yield a large quantity of cells within a short period of time that will be of benefit in banking MCC cells for reconstruction of impaired cartilage.

Animals↗
PubMed2000

[Effect of reinforcing qi and moistening intestine oral liquid on anorectal manometry of asthenia type constipation patients].

OBJECTIVE: To study the change of anorectal manometry in asthenia type constipation patients and effect of reinforcing Qi and moistening intestine oral liquid (RQMI) on it. METHODS: The fotal of 135 cases were divided into healthy group, RQMI treated group, Maren pill (MRP) treated group and prepulside (PPS) treated group, their anal maximal voluntary squeeze pressure, rectoanal contraction reflex, rectoanal inhibitory reflex, defecation reflex, rectal volume sensory threshold and rectal maximal tolerable volume were observed. RESULTS: The rectal sensory function of patients weakened obviously and anal sphincter reactivity reduced as compared with those of healthy person (P < 0.01), and both were improved by RQMI treatment (P < 0.05). CONCLUSION: RQMI is superior to MRP and prepulside in improving anorectal dynamic abnormality in constipation patient of asthenia type.

Adult↗
PubMed2000

[Correlation of intrauterine growth retardation with endocrine parameters].

OBJECTIVE: To investigate the relationship between intrauterine growth retardation (IUGR)and endocrine parameters and to assess the effects of the main endocrine factors on IUGR. METHODS: The concentrations of growth hormone (GH), insulin, triiodothyronine (T(3)), tetraiodothyronine (T(4)), and thyroid-stimulating hormone (TSH) were measured in maternal serum, umbilical blood and amniotic fluid. The samples were collected from 23 term pregnancies with IUGR, and 42 normal pregnancies served as control. Growth hormone and insulin were measured by radioimmunoassay, and T(3), T(4) and TSH by microradioimmunoassay. RESULTS: The concentrations of GH, insulin and T(4) in umbilical blood were lower in IUGR group than that in the normal group (IUGR: GH 4.63 microg/L vs 7.01 microg/L, insulin 10.68 mIU/L vs 31.44 mIU/L, T(4) 0.68 mg/L vs 1.07 mg/L. P < 0.05, 0.05, 0.05), the TSH level in umbilical blood was higher in IUGR than that in the control group (10.84 mIU/L vs 5.74 mIU/L. P < 0.01). The concentration of GH in maternal serum and insulin in amniotic fluid in IUGR group were also lower than that in normal group (GH 1.77 microg/L vs 2.74 microg/L, P < 0.01; insulin 5.84 mIU/L vs 15.64 mIU/L, P < 0.01). CONCLUSIONS: This study confirms previous observation that insufficiency of GH might be a pathogenesis of IUGR. The decrease of GH and insulin might compromise the basic metabolism of the fetus. Besides, the change of early hypothyrosis of fetus with IUGR might benefit them to live in unfavorable environment.

Amniotic Fluid↗
PubMed2000

[Mutation and expression of nm23-H1 and CD44 gene in prostate cancers].

OBJECTIVE: To study the role of nm23-H1 and CD44 gene in carcinogenesis and metastasis of prostate cancers. METHODS: Expression of nm23-H1/NDPK and CD44 protein were analyzed in 32 cases of prostate cancers (Pca) and 12 control of benign prostate hyperplasia (BPH) paraffin embedded tissue by immunohistochemistry. Mutation and expression of their genes were detected by silver SSCP method, semiquantitative RT-PCR, and southern blot hybridization analysis respectively in 25 cases of fresh Pca and 15 control BPH tissue. RESULTS: nm23-H1 gene point mutation was detected in 13.3% (2/15) of Pca. Compared with the control tissue, the expression of nm23-H1 gene was increased significantly on both mRNA and protein levels in the carcinoma tissue (P < 0.05). The expression of nm23-H1 protein was also increased significantly in Pca with metastasis. The expression of CD44 standard form (CD44s) protein was significantly reduced in most Pca compared with BPH tissue. CD44s mRNA was detected in all Pca and BPH tissue, whereas CD44 variant (CD44v) without CD44v6 was mainly detected in carcinoma tissue. CONCLUSIONS: The altered expression of CD44s and CD44v may co-regulate in the carcinogenesis and progression, whereas nm23-H1 gene may play a different role from CD44 in the progression of prostate cancer. CD44v6 may be a useful but not significant tool for detection of colon or bladder cancers.

Gene Expression↗
PubMed2000

[An epidemiological study on acute diarrhea during a filed exercise in PLA unit in an area in southern China].

OBJECTIVE: To explore the epidemiological characteristics and risk factors of acute diarrheal disease during a filed exercise. METHODS: Epidemiological study of a certain artillery acute diarrheal disease during a filed exercise and multiple linear stepwise regression analysis, multiple stepwise discriminate analysis were used. RESULTS: Result showed that the incidence rate of training troops was significantly higher than that of the local troops at the corresponding period (7.32% vs 0.98% P<0.05). The incidence rate among officers was significantly lower than that of the soldiers (0.99% vs 8.20% P<0.05). The incidence rate was significantly higher at the beginning of assemble for training but smooth and steady afterwards with several outbreaks. There was highly significant difference in the incidence rate of 39 companies. Regression and discrimination analysis suggested that the incidence rate was correlated with the density of flies and average boiled water volume provided everyday. The correct classifying rate of the discrimination was 91.9% in total. CONCLUSION: These results provided a basis for prevention of acute diarrheal disease during filed exercise of military action.

Acute Disease↗
PubMed2000

[The relationship between polymorphism of angiotensinogen gene and essential hypertension].

OBJECTIVE: To study the renin-angiotensin system (RAS) involvement in the hormonal regulation of BP and blood volume and the relationship between angiotensinogen (AGT) was the sole preliminary acting materials in the RAS. METHOD: Population-based case-control study was conducted using PCR-RFLP techniques to explore the relationship between the M235T polymorphism of AGT and EH in Wangxin township, Jiading District of Shanghai. RESULTS: The frequency of TT genotype in EH cases was significantly higher than in controls (42.8% and 33.0%). The odds ratio (OR) for those exposed to TT genotype was 3.61, comparing with MM genotype. It was suggested that TT genotype be the susceptible genotype of EH in Wangxin. The frequency of allele T in EH cases was 73.89%, significantly higher than that of 60.31% in controls. With the increase of allele T, the risk of EH also increased (P < 0.05). In EH cases, the BMI increased in the order of MM, MT and TT, and significant differences between the groups were observed. CONCLUSION: TT genotype is the susceptible genotype of EH in Wangxin.

Aged↗
PubMed2000

[A cross-sectional study on the effects of microcystin in drinking water to the health of human beings].

OBJECTIVE: To understand the effects of microcystin (MC) in drinking water on health of human beings. METHODS: In Taixing, a cross-sectional study was conducted in two middle schools with different types of drinking water, from which 111 and 92 students were randomly selected and investigated. Blood samples from all individuals were collected and tested for serum HBsAg, HBeAg, anti-HBe, anti-HBs, anti-HBc with enzyme linked immunoabsorbent assay and for serum alanine aminotransferase (ALT), gamma-glutamyltransferase (gamma-GT) and alkaline phosphatase (ALP) contents by colorimetry. These levels of enzymes in sera were compared after the students were stratified according to the status of HBV infection. RESULT: With the exclusion of the effect of HBV infection, three enzymes levels in sera between two groups of students showed significant differences (P < 0.01), much higher in exposure group than those in control group. CONCLUSION: MC was possibly harmful to human beings in drinking water and induced the contents of some enzymes from the liver of human beings to increase in sera.

Adolescent↗
PubMed2000

[Relationship of bcl-2 gene expression with cell proliferation and apoptosis in human gliomas].

OBJECTIVE: To investigate the relationship of bcl-2 gene expression level in human gliomas with the malignant degree, cell proliferative activity and apoptosis of the tumors. METHODS: The expression of bcl-2 mRNA, bcl-2 protein and proliferating cell antigen, and the apoptosis in sixty-nine human glioma specimens with different malignant grades were studied using in situ hybridization, in situ cell death detection (TUNEL method) and immunohistochemistry. RESULTS: Of the 69 gliomas, 64 (92.8%) and 60 (87.0%) expressed bcl-2 mRNA and bcl-2 protein, respectively. The expression levels of bcl-2 mRNA and bcl-2 protein were correlated positively with each other (r(s) = 0.999, P < 0.01). The expression levels of bcl-2 mRNA and bcl-2 protein were both higher in WHO grade IV gliomas than in grade III gliomas, and the expression was lowest in grade I-II gliomas (P < 0.02 approximately 0.001). With the increase in the expression of bcl-2 protein, the cell proliferating activity increased and apoptosis decreased in the tumor cells. There was significant difference of cell proliferation and apoptosis between + + + group and + + group of bcl-2 protein expression (P < 0.05) as well as between both the former groups, and the negative and + group (P < 0.01) respectively. CONCLUSIONS: Over-expression of bcl-2 gene inhibits apoptosis of glioma cells, and the inhibitory intensity increases with the ascending of bcl-2 gene expression level in glioma cells. Both the decrease in apoptosis caused by bcl-2 gene over-expression and the excessive cell proliferation promoted by other gene abnormalities may result in unlimited cell accumulation, which may play an important role in the development and malignant progression of gliomas.

Adolescent↗
PubMed2000

[Study on method of sampling and analysis of acephate in the air].

Acephate in the air was collected with polyurethane foamed plastics, desorbed with methanl, separated with a column 2% DEGS and determined by GC-FPD. The detectable limit was 0.052 mg/m3. When the concentration of standard solution was 3-15 micrograms/ml, the relative standard deviation(RSD) was 4.5%-2.3%. The desorption efficiency was above 85%. The sampling efficiency was 100%. The samples were stable for 24 h. It was proved that the method was accurate, fast and simple. It was suitable for the determination of acephate in the air.

Air Pollutants, Occupational↗
PubMed2000

[The changes of GFAP and PCNA after human brain contusion: an immunohistochemical study in forensic pathology].

In order to find out changes of GFAP and PCNA after human brain trauma, samples of 38 cases were studied by the immunnohistochemistry method combined with quantitative image analysis. The gray degree and area of PCNA positive cells increased to the maximum at the 4th day and then decreased gradually. GFAP positive cells began to increase significantly 12 hours after contusion, reached the maximum at the 4th day and stayed in high level until the 7th day. These results suggest that: (1) GFAP, PCNA show regular changes with survival time after brain contusion; (2) GFAP and PCNA can be used as time markers of brain contusion from 2-20 days.

Adult↗
PubMed2000

[Fibronectin in adhesion, spreading and proliferation of mandibular condylar cartilage cells on cytodex-3 microcarrier].

OBJECTIVE: The purpose of this study was to investigate the effects of exogenous fibronectin on the attachment and growth of mandibular condylar cartilage (MCC) cells on DEAE-dextran micro-carrier. METHODS: MCC cells were harvested from newborn New Zealand white rabbits by sequential digestion with trypsin and collagenase. They were grown on the 20 mg/L fibronectin-coated and uncoated cytodex-3 micro-carrier. Samples were collected after 1, 3, 5, 7, 9, 11 days. The kinetics of adhesion and growth were observed with phase contrast microscope and environmental scanning electronic microscope (ESEM) and quantified by 0.1% crystal violet nuclear extrusion method. RESULTS: MCC cells could rapidly attach and spread onto the fibronectin-coated cytodex-3, and nearly 60 percent cells attached to the micro-carrier within 2 hours. Spreading cells were flat and lowly refractile observed under phase contrast microscope. While the attachment and spreading of the cells in the untreated group were slow, and only 36 percent cells attached to the uncoated micro-carrier. However, most cells attached to the micro-carrier in both groups after 24 hours. The MCC cells attaching to FN-coated cytodex-3 observed under ESEM were flatter and adhered tightly with more processes (pseudopodia) stretching out from cytoplasm. In contrast, cells on untreated cytodex-3 remained regularly round even 24 hours after being plated. Meanwhile, there was an accelerated growth rate of the MCC cells on the fibronectin treated cytodex-3. The cell density in the FN treated group was higher than that of the untreated group at the end of the culture. CONCLUSION: Fibronectin, one major glycoprotein of extracellular matrix, plays an important role in cell attachment and spreading. The better understanding of the extracellular matrix will be helpful in selecting the optimal substrate for cell growth in vitro.

Adhesiveness↗
PubMed2000

[The immunohistochemical and electron microscopical study of pathological classification of Melkersson-Rosenthal syndrome].

OBJECTIVE: To prove further the pathological classification of Melkersson-Rosenthal syndrome (MRS) and observe the morphological features of the granuloma cells in MRS. METHODS: We studied 20 cases of MRS, with 10 cases of granuloma type and the other 10 cases of non-granuloma type. The negative results of periodic acid-schiff (PAS), Neelren anti-acid special staining and tuberculosis (TB)-DNA polymerase chain reaction proved that all cases were not TB and fungous disease. Then all the cases were labelled with antibody of lysozyme by immunohistochemical staining and investigated with electron microscope. We studied the expression of lysozyme in multinucleated giant cells, epithelioid cells and histiocytes. RESULTS: The results of lysozyme staining were positive in the multinucleated giant cells, epithelioid cells and histiocytes of the granuloma type and were negative in those cells of the non-granuloma type. On the other hand, the small multinucleated giant cells which had 2-3 nuclei were the features of the morphological structure of the granuloma type. The small multinucleated giant cells were not seen in the non-granuloma type. CONCLUSION: In this paper, two pathological types (granuloma and non-granuloma type) in the MRS were proved further and it is found that the different structures of granuloma can be used to discriminate between MRS and sarcoidosis and tuberculosis.

Diagnosis, Differential↗
PubMed2000

[Effects of cultivating measures on root rot of Panax notoginseng].

OBJECTIVE: To probe into the effects of cultivating measures on root rot of Panax notoginseng for the integrate control. METHOD: Field investigation on the planting plots was conducted. CONCLUSIONS: Effects of cultural system on root rot are obvious, (1) The rotation period should be more than eight years; (2) Improper fertilizer application is one important fact of the root rot occuring; (3) The light transmitting rate is one important fact; (4) Laying film and using sun-shade shed can reduce the root rot.

Fertilizers↗
PubMed2000

[Transgenic mice model of human hepatitis B virus x gene].

OBJECTIVE: To set up a human hepatitis B virus x (HBx) gene transgenic model. METHODS: The model was set up by microinjection, the integration and expression of the founders were identified by molecular hybridization. RESULTS: A 1,800 bp DNA fragment containing the human HBx promoter and genomic DNA was microinjected into the male pronucleus of the fertilized eggs of mice. Three hundred and thirty-eight eggs survived from microinjection were transplanted into the oviduct of 16 pseudopregnant female, 12 pseudopregnant mice got pregnant and gave birth to 74 pups. Genomic DNA were extracted from the tails of the pups, Southern blot hybridization was used for determination of the integration of human HBx gene. The 1,800 bp microinjected fragment was used as the probe, 17 mice (founders) were identified of the integration of human HBx gene. Total RNA were extracted from the livers of the founders, all 17 founders were identified of the expression of human HBx gene by using Northern blot hybridization. CONCLUSIONS: These results may provide animal models for studying on the correlation between chronic HBV infection and the development of hepatocellular carcinoma.

Animals↗
PubMed1999

Regulation of BAD phosphorylation at serine 112 by the Ras-mitogen-activated protein kinase pathway.

The function of the pro-apoptotic molecule BAD is regulated by phosphorylation of two sites, serine-112 (Ser-112) and serine-136 (Ser-136). Phosphorylation at either site results in loss of the ability of BAD to heterodimerize with the survival proteins BCL-XL or BCL-2. Phosphorylated BAD binds to 14-3-3 and is sequestered in the cytoplasm. It has been shown that phosphorylation of BAD at Ser-136 is mediated by the serine/threonine protein kinase Akt-1/PKB which is downstream of phosphatidylinositol 3-kinase (PI3K). The signaling process leading to phophorylation of BAD at Ser-112 has not been identified. In this study, we show that phosphorylation of the two serine residues of BAD is differentially regulated. While Ser-136 phosphorylation is concordant with activation of Akt, Ser-112 phosphorylation does not correlate with Akt activation. Instead, we demonstrate that activated Ras and Raf, which are upstream of mitogen-activated protein kinases (MAPK), stimulate selective phosphorylation of BAD at Ser-112. Furthermore, phosphorylation of Ser-112, but not Ser-136 requires activation of the MAPK pathway as the MEK inhibitor, PD 98059, blocks EGF-, as well as activated Ras- or Raf-mediated phosphorylation of BAD at Ser-112. Therefore, the PI3K-Akt and Ras-MAPK pathways converge at BAD by mediating phosphorylation of distinct serine residues.

3T3 Cells↗