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Biomedical subjects

S Xie

Publications and source records attributed to S Xie.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Development of biogenic VOC emissions inventory with high temporal and spatial resolution].

A new method was developed to estimate biogenic VOC emissions with high temporal and spatial resolution by use of Mesoscale Meteorology Modeling System Version5 (MM5). In this method, the isoprene and monoterpene standard emission factors for some types of tree in China were given and the standard VOC emission factors and seasonally average densities of leaf biomass for all types of vegetation were determined. A biogenic VOC emissions inventory in South China was established which could meet the requirement of regional air quality modeling. Total biogenic VOC emissions in a typical summer day were estimated to be 1.12 x 10(4) metric tons in an area of 729 km x 729 km of South China. The results showed the temporal and spatial distributions of biogenic VOC emission rates in this area. The results also showed that the geographical distribution of biogenic VOC emission rates depended on vegetation types and their distributions and the diurnal variation mainly depended on the solar radiation and temperature. The uncertainties of estimating biogenic VOC emissions were also discussed.

Atmosphere↗
PubMed2001

[Changes in the activity of platelet L-arginine/nitric oxide pathway in hypercholesterolemia patients].

OBJECTIVE: To investigate the changes of the platelet L-arginine (L-Arg)/nitric oxide (NO) pathway in hypercholesterolemia patients. METHODS: The platelet NO production in 21 hypercholesterolemia (HC) patients and 26 normal individuals was assayed by spectrum, the NOS activity and the transportation of L-Arg were determined by (3)H-labelled L-Arg. RESULTS: The NO production in hypercholesterolemic platelets [(24.06 +/- 3.70) nmol/10(8) platelets] was decreased significantly as compared with normal controls [(28.39 +/- 4.45) nmol/10(8) platelets] (P < 0.01), and so did the NOS activity [(1.46 +/- 0.47) pmol/10(8) platelets] vs (1.81 +/- 0.50) pmol/10(8) platelets]. The transportation of L-Arg by hypercholesterolemia platelets also decreased significantly than that by normal controls. The Vmax in the former [(46.84 +/- 3.39) pmol x (10(7) platelets)(-1) x min(-1)] was significantly lower than that in the latter [(53.89 +/- 3.45) pmol x (10(7) platelets)(-1) x min(-1)]. There was no difference between the two groups in K(d) (P > 0.05). CONCLUSIONS: The activity of the L-arg/NO pathway in hypercholesterolemia platelets is decreased significantly as compared with normal controls, implying that it is probably one of the reasons for the hyperactivity of hypercholesterolemia platelets.

Adult↗
PubMed2001

[Induced tolerance to cardiac allografts with intrathymic injection of donor spleen cells].

OBJECTIVE: To study the methods and mechanisms of immune tolerance in cardiac transplantation. METHODS: Male DA rat hearts were transplanted to male Lewis rats using Ono's model and randomly divided into four groups: untreated (group I), intrathymic injection of 2.5 x 10(7) DA splenocytes to Lewis rat (group II), intraperitoneal injection of 1 ml rabbit anti-rat lymphocyte serum (ALS) to Lewis recipient (group III), intrathymic injection of 2.5 x 10(7) DA splenocytes combined with intraperitoneal injection of 1 ml rabbit anti-rat lymphocyte serum (ALS) to Lewis recipient (group IV). 21 days later heart transplantation was performed. Mean survival time (MST), histological changes and mixed lymphocyte reaction (MLR) were measured after operation. RESULTS: In the group of intrathymic injection of spleen cells combined with ALS treatment, the survival time of heart allografts [MST: (81.8 +/- 7.6)d] was significantly longer than in the groups I [MST: (7.3 +/- 1.0) d], group II [MST:(7.8+/- 1.0)d], and group III [MST(8.2 +/- 1.2) d, P < 0.01]. Only a few inflammatory cells infiltrated in cardiac allografts in group IV. MLR of group IV were significantly decreased compared with those of the normal control (P < 0.01). CONCLUSIONS: The role of thymus as a special site for induction and maintenance of specific immunological unresponsiveness to organ allografts was confirmed. T cell clonal deletion may play an important role in this immune tolerance.

Animals↗
PubMed2000

Critical loads of acidity for surface waters in China.

For further control of acid rain and sulphur dioxide pollution, the Chinese government has designated the Acid Rain Control Zone and the Sulphur Dioxide Pollution Control Zone for those areas that are, or could become, affected by acid deposition or ambient sulphur dioxide concentrations. One of the most important principles for designating the Acid Rain Control Zone is that the critical load is exceeded by the sulphur deposition. Through the steady-state water chemistry method (SSWC), critical loads of acidity for surface waters were mapped based on available data. Results show that surface waters sensitive to acid deposition, i.e. surface waters with low critical loads, are mainly found in north-east China, on the Tibetan Plateau, and in north-west China. Compared with the critical loads of soils, critical loads of surface waters are usually higher in almost all areas in China. The reason for very low critical loads of surface waters in some regions dominated by soils geologically not sensitive to acid deposition may be attributed to the low temperature, high altitude and low runoff. In contrast, surface waters in south China are not susceptible to acid deposition, and so far acidification of surface water has not been found in spite of the heavy acid rain. As can be seen from the critical load exceedance map, nearly 10% of the surface waters are subject to risk of acidification in 1995.

Acid Rain↗
PubMed2000

Antimalarial sulfide, sulfone, and sulfonamide trioxanes.

A series of trioxanes featuring sulfide, sulfone, and sulfonamide substituents in diverse positions has been prepared. Structure-activity relationship (SAR) generalizations highlight two major factors controlling the antimalarial potency of these new chemical entities: (1) the proximity of the sulfur-containing substituent to the crucial peroxide bond and (2) the oxidation state of the sulfur-containing substituent. Generally, sulfones are more antimalarially potent than the corresponding sulfides.

Antimalarials↗
PubMed2000

Pregnancy-associated bovine and ovine glycoproteins exhibit spatially and temporally distinct expression patterns during pregnancy.

The pregnancy-associated glycoproteins (PAG) constitute a large family of recently duplicated genes. They show structural resemblance to pepsin and related aspartic proteinases. A total of 21 bovine (bo) PAG and 9 ovine (ov) PAG cDNA have been identified. Phylogenetic analysis indicated that the PAG are divided into two main groupings that accurately reflect their tissue expression, as determined by in situ hybridization. In the first pattern, represented by ovPAG-2 and boPAG-2, -8, -10, and -11 (where the numbering is arbitrary and reflects order of discovery within species), expression occurred throughout the outer epithelial layer of the placenta (trophectoderm). The second pattern was predominant localization to binucleate cells. Ribonuclease protection assays, which allow discrimination between closely related transcripts, have shown that the expression of PAG varies in a temporal manner over pregnancy. Of those bovine PAG expressed predominantly in binucleate cells, boPAG-1, -6, and -7 are expressed weakly, if at all, by Day 25 placenta, but are present at the middle and end of pregnancy. Others, such as boPAG-4, -5, and -9, are expressed at Day 25 and at earlier stages. Although not among the earliest PAG produced by the trophoblast, boPAG-1 has been used for pregnancy diagnosis, particularly in dairy cows, where there is a major need for a sensitive method capable of detecting pregnancy within 1 mo of conception. It seems likely that some of the newly discovered PAG will be better candidates than PAG-1 for pregnancy diagnosis.

Animals↗
PubMed2000

Clinical observation and experimental study on compound hypoglycemic decoction for hyperglycemia.

PURPOSE: To observe the clinical efficacy of Compound Hypoglycemic Decoction (CHD) and its effect on serum total cholesterol in model mice. METHOD: The paired t test was used to analyze the data recorded before and after administration of drugs for hyperglycemia induced by intraperitoneal injection of 75% egg yolk emulsion in experimental mice. CHD and Fenofibrate were administered as prevention measures. RESULTS: The total effective rate of serum total cholesterol (TC) decrease in 60 cases of hyperglycemia was 86.66% and that of serum total triglyceride (TG) decrease was 81.81%. The total effective rate of high-density lipoprotein-cholesterol (HDL-C) increase was 75%. The decrease in TC and TG, and the increase of HDL-C after treatment by in-group comparison were all significant (P < 0.05). 21.9% and 22.2% decrease in the total cholesterol was respectively found in the CHD and Fenofibrate groups (both P < 0.05), with no significant difference. CONCLUSION: The hypoglycemic action of Compound Hypoglycemic Decoction was remarkable in clinical practice, and it is very effective in preventing hyperglycemia in experimental mice.

Adult↗
PubMed2000

[The relationship between the levels of serum fibrosis marks and morphometric quantitative measurement of hepatic histological fibrosis].

OBJECTIVE: To study the relationship between the levels of serum fibrosis marks hyaluronic acid (HA), procollagen type III (PCIII), collagen type IV (CIV) and the degree of hepatic fibrosis, and the clinical significance of HA, PCIII, CIV in the diagnosis of hepatic fibrosis to the chronic viral hepatitis. METHODS: The concentrations of serum HA, PCIII, CIV in 151 patients with chronic viral hepatitis were measured by radioimmunoassay. Liver biopsies were performed in all of the patients at the same time. Morphometric quantitative measurements of hepatic fibrosis were performed in 4mum sections stained with masson stain using a fully automated image-analysis system. RESULTS: The levels of serum HA, PCIII, CIV were all increased steadily with the progression of hepatic fibrosis, and the highest levels were in stage 4. They were all positively correlated with staging of the liver pathology and morphometric measurement of hepatic fibrosis (P<0.001). The coefficient value (r) with staging were 0.694, 0.493, 0.552 (P<0.001), respectively and with morphometric measurement of hepatic fibrosis were 0.715, 0.596, 0.537 (P<0.001), respectively. CONCLUSION: The levels of serum HA, PCIII, CIV are in concert with the degree of hepatic fibrosis, and the determination of these marks may be valuable for diagnosing hepatic fibrosis.

Adolescent↗
PubMed2000

[Spread of Chinese variolation art to the western world and its influence].

Smallpox inoculation or variolation is a great invention of medicine in ancient China. In this paper, we introduced the process of spread of smallpox inoculation technique from China to western world (mainly to England), and reviewed the royal experiment of smallpox inoculation on human being and its influence on the prevention of smallpox in western countries. The spread and practice of smallpox inoculation in western world was an important event in the history of intercommunication between eastern and western medicines, which is worth emphasizing and further studying.

China↗
PubMed2000

Intravesical immunotoxin as adjuvant therapy to prevent the recurrence of bladder cancer.

OBJECTIVE: To assess the intravesical application of immunotoxin as adjuvant therapy to prevent recurrence after tumor resection in bladder cancer patients. METHODS: An anti-human immunotoxin against bladder carcinoma, BDI-1-RT, was prepared and its in vitro targeting cytotoxicity estimated. The immunoreactivity of BDI-1-RT with human bladder cancer tissue of different grades and stages was detected by immunohistochemical analysis. After safety test, intravesical administration of BDI-1-RT was performed in 31 patients while mitomycin C (MMC) was used in 36 patients serving as a control group. The recurrence rates and side effects in both groups were recorded. In addition, the development of human anti-mouse antibodies (HAMA) was determined by ELISA, to assess the potential safety of this immunotoxin. RESULTS: In our study, BDI-1-RT had immunoreactivity with 81.6% of bladder transitional cell carcinomas. The immunoreactivity of BDI-1-RT correlated with tumor grade. High-grade carcinoma had stronger staining than low-grade (P < 0.05). There was no significant difference between the BDI-1-RT group (10%) and MMC group (19.3%) in recurrence rate (P > 0.05). Side effects, including systemic and local, were more frequent in the MMC group (11 of 36 patients versus 2 of 31, P < 0.05). HAMA was not detected in any of 7 patients. CONCLUSION: Immunotoxin may have considerable potential in the prophylaxis of bladder transition cell carcinoma.

Administration, Intravesical↗
PubMed2000

[Correlation of transplantation tolerance and chimerism induced by allogeneic parabiosis in adult rats].

OBJECTIVE: To induce transplantation tolerance by allogeneic parabiosis in adult rats to explore the relation between chimeras and tolerance. METHODS: Cyclophosphamide (CP, 100 mg/kg) was intraperitonially administered before and after parabiosis to observe the survival days of parabiotic rats. Grafting skin for each other after separation of parabiosed rats pairs on day 5, 15 and 45 respectively to observe the survival time of skin graft survival. In the same time the percentage of cells of donor origin in the spleen and thymus of recipient rats were determined by FACS. Mixed lymphocyte reaction (MLR) and delayed type hypersensivity (DTH) at day 15 of parabiosis were tested. RESULTS: Survival days of parabiotic rats were significantly prolonged (P = 0.000 5, MST = 63.5 days). After 15 day of parabiosis, the stable skin transplantation tolerance was established. During the first 15 day of parabiosis, the level of chimerism was increased with time, afterwards the chimerism became relatively stable. DTH and MLR of parabiotic rats on day 15 were donor-specifically suppressed. CONCLUSION: Parabiosis can induce specific transplantation tolerance in both parabiotic DA and LEW rats. There is a positive correlation of chimerism and transplantation tolerance.

Animals↗
PubMed2000

[Influence of pravastatin on expression of platelet CD(62P) and CD(41) in patients with hypercholesterolemia in vitro and in vivo].

OBJECTIVE: To study in vitro and in vivo effect of hypercholesterolemia (HC) on expression of platelet CD(62P) and CD(41) and their changes after treatment with pravastatin. METHODS: Twenty patients with HC were given 10 - 20 mg/d pravastatin orally for 4 - 8 weeks. Changes of blood cholesterol and expression of platelet CD(62P) and CD(41) were detected by flow cytometry. RESULTS: After 4 and 8 weeks' treatment, blood cholesterol level and platelet aggregation function decreased. The expression of CD(62P) average fluorescence intensity decreased from 31.8 +/- 7.8 to 27.2 +/- 6.9 and 26.8 +/- 4.9; CD(62P) (%) from (31.3 +/- 9.3)% to (26.4 +/- 7.4)% and (25.3 +/- 9.1)% (P < 0.05); CD(41) from 483.2 +/- 263.9 to 348.1 +/- 192.4 and 306.8 +/- 128.0 (P < 0.05), respectively. Similar results were obtained in vitro study. CONCLUSION: Improvement of platelet function and expressions of CD(62P) and CD(41) in HC patients after prevastatin treatment may be resulted from enhancing arteriosclerosis regression. It suggested from the in vitro result that pravastatin might play a direct effect on platelet function.

Adult↗
PubMed2000

[Influence of the administrators of family planning on the spread of norplant in countryside of Sichuan].

The purpose of the study was to understand the family planning administrators' knowledge of Norplant and their fluence on the spread of Norplant in countryside of Sichuan. 156 administratoras were surveyed. It was found that most of the administrators worked hard on education, propagation, organization and management of using Norplant, and they recognized the contraceptive efficacy of Norplant. However, the educational level of the administrators was generally low. They were short of the training on Norplant related knowledge(training rate was only 36.5%). The degree of the users' satisfaction and the administrators' knowledge on Norplant varied between areas. The result indicated that the basic quality of the administrators and their knowledge of Norplant were influences on the spread of Norplant in the countryside of Sichuan. Soit is very important to improve the basic quality and knowledge of the administrators of family planning.

Adolescent↗
PubMed2000

[Therapy for short stature in girls with Turner syndrome].

This study was aimed to examine the growth-promoting effects of recombinant human growth hormone (r-hGH) and low dose of thyroid hormone on short stature in girls with Turner syndrome. 8 girls with Turner syndrome, at the chronological age of 8.5-14.5 years (12.3 +/- 2.1 years) and bone age of 8.3-12.7 years (9.8 +/- 1.7 years) were observed. The maximum serum GH levels in 3 patients out of 5 with provocative testing available were > or = 10 ng/ml (10.0, 10.0 and 15.52 ng/ml, respectively), and in the other 2 of the 5 patients were < 10 ng/ml (9.3 and 9.5 ng/ml). Thyroid function including T3, T4 and TSH were measured in 5 patients. The TSH in one patient was slightly higher; the T3, T4 and TSH in other patients were normal. All patients were treated with r-hGH 1.0 IU/(kg.wk) and thyroideum 15 mg/d for 6-36 months. The results showed that the growth rate after treatment was remarkably higher than that before treatment (2.2 +/- 1.1 cm/yr). The growth rates in the first 6 month, the first year, the second year and the third year were 7.9 +/- 1.6 cm/yr, 7.5 +/- 1.2 cm/yr, 6.9 +/- 0.2 cm/yr and 5.0 +/- 0.2 cm/yr, respectively. Height standard deviation score (HSDS) increased 1.3 +/- 1.1 SD, compared with that pretreatment. The annual bone age growth rate after treatment was 0.6 +/- 0.2 yr/yr (0.43-0.8 yr/yr). These data indicated that r-hGH and low dose of thyroid hormone had remarkable effects of growth-promoting in the girls with Turner syndrome.

Adolescent↗
PubMed2000

[Induction of skin immune tolerance of mouse to rat xenogeneic transplantation].

OBJECTIVE: To explore a moderate and effective project which will be clinically suitable to induce donor-specific tolerance across xenogeneic barriers. METHODS: 4 x 10(7) Lewis rat bone marrow cells were infused to 300 rad total body irradiated (TBI) C57BL/6 (B6) mice, combined with intraperitoneal administration of cyclophosphamide (CTX) and intravenous injection of anti-mouse CD4 monoclonal antibody. Recipient B6 mice were characterized for the tolerance status with donor Lewis rat skin graft, mixed lymphocyte reaction (MLR), and delayed-type hypersensitivity (DTH) assays after 30 days. Adoptive transfer and the effect of IL-2 on MLR were detected to further explore the tolerance mechanism. RESULTS: Survival time of donor rat skin grafts was specifically prolonged in the tolerant B6 mice. The results of MLR and DTH assays showed donor-specific hyporeactivity, while the tolerant B6 mice were still immunocompetent to MHC-disparate third party BALB/c mouse or DA rat stimulator cells. CONCLUSIONS: A reliable xenogeneic transplantation tolerance of mouse to rat was achieved by this project of tolerance induction. The result of in vitro and in vivo adoptive transfer of spleen cells from tolerant B6 mice demonstrated that the suppressor cells were unlikely to exert effect in the tolerance. The inhibition of specific MLR could be reversed by adding IL-2, indicating that clonal anergy instead of clonal deletion is responsible for the tolerant maintenance.

Animals↗
PubMed1999

Rapid reversed-phase separation of proteins and peptides using optimized 'moulded' monolithic poly(styrene-co-divinylbenzene) columns.

Monolithic macroporous poly(styrene-co-divinylbenzene) stationary phases have been prepared by free radical polymerization within the confines of 4.6-mm I.D. chromatographic columns. The optimized porous properties allow the mobile phase to flow through these columns at flow-rates of up to 10 ml/min. As opposed to the simultaneously tested columns packed with either silica or synthetic polymer beads, the monoliths exhibit only modest back pressure. The monolithic columns were able to separate mixtures of peptides and proteins in a very short time. Under the optimized conditions, the separation of five proteins can be easily achieved in less than 20 s.

Chromatography, High Pressure Liquid↗
PubMed1999

Antimalarial, antiproliferative, and antitumor activities of artemisinin-derived, chemically robust, trioxane dimers.

Nine C-10 non-acetal derivatives of the natural trioxane artemisinin (1) were prepared as dimers using some novel chemistry. As designed, each dimer was stable chemically. C-10 Olefinic dimers 7 and C-10 saturated dimers 8-13 all showed good to excellent antimalarial and antiproliferative activities in vitro. Dimers 8, 10, and 12 were especially potent and selective at inhibiting growth of some human cancer cell lines in the NCI in vitro 60-cell line assay.

Animals↗