576
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Liu Y, Wang L, Sha D, Zheng S, He J. [Thin layer chromatographic studies on radix Ginseng, fructus Schisandrae and radix Salviae miltiorrhizae in yixinfumai granules]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1992; 17:217-9, 255. [PMID: 1418549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The main constituents of Radix Ginseng, Fructus Schisandrae and Radix Salviae Miltiorrhizae in Yixinfumai Granules were studied by TLC. It was found that ginsenoside got hydrolyzed while the drugs were being boiled together. The main constituents of Fructus Schisandrae were schizandrol A and B; and those of Radix Salviae Miltiorrhizae were tanshinone and protocatechuic aldehyde.
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577
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Zheng S, Beissinger R, Wasan D. MEASUREMENT OF YIELD OF HEMOGLOBIN (HB)-IN-OIL-IN-WATER MULTIPLE EMULSION BASED ON HB ENCAPSULATION EFFICIENCY. J DISPER SCI TECHNOL 1992. [DOI: 10.1080/01932699208943294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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578
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Su S, Zheng S, Su C. [Effects of four adrenergic drugs on electroacupuncture analgesia]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 1992; 17:175-8. [PMID: 1364074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
The role of central nor-epinephrine (NE) in electroacupuncture (EA) analgesia is a controversial question., it is probably due to the complication of adrenergic receptors. The present results show: (1) Clonidine 30 micrograms/2ml/kg ip had no significant effect on the pain threshold, but decreased the analgesic effect of EA. Clonidine 1.5 and 3 micrograms were injected into the lateral cerebral ventricles. After 45 minutes, the analgesic effect of EA was lowered as compared with the saline controls respectively. (2) Yohimbine had no significant effect on the basal pain threshold, but (icv Yoh 50 micrograms) elevated the analgesic effect of EA. (3) 2-adrenoceptor agonist methoxamine decreased the analgesic effect of EA. (4) Another 2-adrenoceptor antagonist prazosin (icv 16 micrograms) enhanced the analgesic effect of EA. These results suggest that an activation of alpha 1- or alpha 2-adrenoceptors would decrease the analgesic effect of EA.
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579
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Fuller L, Fernandez J, Zheng S, Carreno M, Esquenazi V, Yang WC, Miller J. Immunochemical and biochemical characterization of purified canine interferon-gamma. Production of a monoclonal antibody, affinity purification, and its effect on mixed lymphocyte culture and mixed lymphocyte kidney culture reactions. Transplantation 1992; 53:195-202. [PMID: 1531093] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
We have advanced the hypothesis that the primary autolymphoproliferative response of dog T cells in mixed lymphocyte kidney cultures (MLKC) results from their recognition of tissue-specific (kidney-associated) antigen(s) presented in conjunction with class II MHC antigens. Lymphocyte culture-derived supernatants had been found previously to upregulate class II antigen expression on kidney cells and enhance T cell activation. In the present study we have isolated and characterized dog IFN-gamma, a class II-inducing substance that is secreted in the culture supernatant of activated T lymphocytes. Dog IFN-gamma was induced with A-23187 and PMA and purified stepwise using controlled-pore glass, Mono Q anion exchange chromatography, and Superose 6-gel filtration on FPLC. The purification resulted in two molecules of 42 Kd and 31 Kd molecular weights. An IgG1 monoclonal antibody was engendered to these molecules. With this mAb reagent, in immunochemical experiments, we have developed a sensitive ELISA and a method for purifying dog IFN-gamma by affinity chromatography. Species specificity studies indicated that purified dog IFN-gamma reacted with a polyclonal rabbit antihuman IFN-gamma, but not with a mAb to human IFN-gamma. However, the antidog IFN-gamma mAb that was generated also reacted with recombinant human IFN-gamma. In in vitro biological studies, the purified IFN-gamma (two mol. wt. species) upregulated the expression of canine class II MHC molecules on dog tubular epithelial cells and the dog kidney epithelial cell line (MDCK). The antidog IFN-gamma mAb blocked T cell proliferative response to kidney cell and, by inference, the interaction between endogenously released IFN-gamma in vitro with its cell surface receptor, thus inhibiting the induced upregulation of class II. Interestingly, although antidog IFN-gamma markedly blocked the MLKC (10 micrograms mAb/well), there was no effect on the allogeneic MLC. This observation indicates that the cytokine IFN-gamma may be a uniquely key substance amplifying the immune response of T cells to tissue-associated antigens on surrogate antigen-presenting cells that require induced upregulation of class II MHC antigen expression (MLKC), in contrast to reactions in which these antigens are already constitutively expressed on the antigen-presenting cells (mixed lymphocyte culture).
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580
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Zheng S, Zheng Y, Beissinger RL, Fresco R. Liposome-encapsulated hemoglobin processing methods. BIOMATERIALS, ARTIFICIAL CELLS, AND IMMOBILIZATION BIOTECHNOLOGY : OFFICIAL JOURNAL OF THE INTERNATIONAL SOCIETY FOR ARTIFICIAL CELLS AND IMMOBILIZATION BIOTECHNOLOGY 1992; 20:355-64. [PMID: 1391451 DOI: 10.3109/10731199209119655] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
An effective and safe red blood cell substitute is being developed based on double emulsion/evaporation techniques followed by high pressure homogenization to form liposome-encapsulated hemoglobin (LEH). Formulations are made up of hydrogenated phosphatidylcholine (PC, soy or egg), cholesterol, phosphatidylinositol (PI), and alpha-tocopherol in a molar ratio of 1:1:0.2:0.02, respectively. Resulting LEH-encapsulated hemoglobin (Hb) concentrations are greater than 80% of precursor Hb solutions. Met-Hb generation accompanying LEH processing appears to be small with only a 3% increase for encapsulated over precursor. These results correspond to an oxygen content for an LEH suspension sample (50% by volume LEH) of 15 volume% oxygen. Oxygen affinity and cooperativity values for LEH suspensions appear to be near the normal values expected for whole blood. The viscosity of LEH suspension samples (50% by volume LEH in phosphate-buffered saline containing 7.5 wt% albumin) were slightly higher than that of whole blood. The effect of shear rate on leakage of encapsulated Hb from LEH was small, i.e. 0.5% or less. Nearly total isovolemic exchange transfusion using a cannulated rat model demonstrates efficacy of LEH suspension samples. There appears to be no difference in rat internal organ weights between rats exchanged with control compared to rats exchanged with LEH. Circulation half-life following 50% isovolemic exchange-transfusion is about 15 to 18 hours.
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581
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Jacobs HA, Day GM, Jackson WR, Simon GP, Watson KG, Zheng S. Synthesis and Characterization of a Series of Liquid Crystal Monomers Containing a Novel Spacer Group Based on Vinylacetic Acid. Aust J Chem 1992. [DOI: 10.1071/ch9920695] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
A series of liquid crystal monomers with side chains involving a vinylacetic acid unit have been prepared, and their thermal and optical properties compared with those of related compounds containing the same mesogenic unit but a conventional polymethylene spacer group based on a terminal alkene.
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582
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Martus KE, Zheng S, Becker K. Electron-photon coincidence study of heavy-noble-gas excitation at small scattering angles. PHYSICAL REVIEW. A, ATOMIC, MOLECULAR, AND OPTICAL PHYSICS 1991; 44:1682-1693. [PMID: 9906135 DOI: 10.1103/physreva.44.1682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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583
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Zheng S. [The screening model for early diagnosis of colorectal cancer in general population]. ZHONGHUA YI XUE ZA ZHI 1991; 71:381-4, 28. [PMID: 1659480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In this study, 75,813 asymptomatic individuals above 30 in Jiashan County of Zhejiang Province were recruited in the screening program. Based on results of risk assessment using a mathematical model (expressed as AD value) and Reverse Passive Hemagglutination Fecal Occult Blood test (RPHA FOB). 62,667 subjects (82.7%) who completed two procedures were divided into 4 groups: 1) AD greater than or equal to 0.3 FOB (+) accounts for 1.2% of total; 2) AD less than 0.3 FOB (+) 3.0%; 3) AD greater than or equal to 0.3 FOB (-) 26.8%; 4) AD less than 0.3 FOB (-) 68.9%. Individuals in groups 1 and 2 were subjected to 60 cm fiberoptic colonoscopic examination; and those of group 3 with AD greater than or equal to 0.5 or with AD less than 0.5 but a positive repeated FOB test was also eligible for 60 cm colonoscopy. Out of 4,299 eligible subjects 3,162 were examined with 60 cm sigmoidoscopy (73.6%). 21 cases of colorectal cancer and 331 cases of polyps (including 75 adenomas) were detected. Among 21 cancers known of Dukes' stages 10 were at early stages (10 Dukes' A and 5 Dukes' B) accounting for 71.5%. According to the screening protocol individuals with negative 60 cm colonoscopic findings and consistently positive FOB results indicate that the lesion may be located above the spleen flexure and require a full fiberoptic colonoscopic examination (150 cm) and/or x-ray air-barium enema.
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584
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Yu J, Zheng S, Shen X. [Steroidal constituents from Saussurea gossypiphora D. Don]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1991; 16:356-8, 383. [PMID: 1786098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Four steroids were isolated from the Saussurea gossypiphora for the fist time. They were determined as 3-stigmastanol, beta-sitosterol, stigmast-7-en-3-ol and ergostan-3,24-diol by spectral and chemical methods.
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585
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Wu-Williams AH, Lee M, Whittemore AS, Gallagher RP, Jiao DA, Zheng S, Zhou L, Wang XH, Chen K, Jung D. Reproductive factors and colorectal cancer risk among Chinese females. Cancer Res 1991; 51:2307-11. [PMID: 2015594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
We report results from a population-based case-control study of colorectal cancer among Chinese women in western North America (NA) and the People's Republic of China (China). A common protocol was used to assess reproductive characteristics and hormone use of 395 Chinese women (189 from NA and 206 from China) with cancer of the colon or rectum and of 1112 age-matched Chinese controls (494 from NA and 618 from China). In NA, risks for cancers of both the colon and rectum were lower among parous compared to nulliparous women (odds ratio for colorectal cancer, 0.6, P = 0.08), but the trend in risk was not smooth with increasing number of livebirths. This association with parity was absent for both cancer sites in China. There were no consistent patterns in the relationships between other reproductive factors (including age at menarche, age at first livebirth, menopausal status) and risk of colon and rectal cancer on either continent.
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586
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Zheng S. [Dynamic observation on the incidence and mortality rates of the nasopharyngeal carcinoma (NPC) in Zhongshan City 1970-1984]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1991; 12:106-10. [PMID: 2065339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The standardized incidence rate of NPC was 14.44/10(5) (male 20.31/10(5), female 8.95/10(5] and the standardized mortality rate was 10.91/10(5) (male 16.00/10(5), female 6.14/10(5] in Zhongshan city during 1970-1984. The fluctuation of incidence and mortality rates were 13.66-18.07/10(5) and 9.02-13.95/10(5) respectively. It was worthy to be mentioned that both the incidence and mortality rate of NPC were relatively stable in 1970-1984.
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587
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Fuller L, Carreno M, Zheng S, Esquenazi V, Yang W, Miller J. Isolation of anti-OKT3 and anti-(anti-OKT3) from a kidney transplant recipient. Transplant Proc 1991; 23:305-6. [PMID: 1899306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
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588
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Zheng S. [Estrogen receptor content in human embryo]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1990; 12:246-51. [PMID: 2147583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Estrogen receptor (ER) content was measured in 27 human embryos, aged 3 to 7 months, with 17-fluoreceinated estrone (17-FE). ER was demonstrated in a uneven distribution pattern in most human embryonic organs. Most embryonic uteri and livers and a few lungs, stomachs and spleens were ER positive. The ER gradually increased with embryonic development in target organs such as the uterus, ovary and testes, as well as in some non-target areas such as mouth and upper digestive system. The ER decreased with embryonic development in the lower digestive system and were maintained at a low level in the lung, heart, brain and lymphoid organs. In the early embryo (3 to 4 months) the ER positive cells (A, B and C type) accounted for a greater proportion of embryonic cells than they did in the late embryonic period (5 to 7 months). The A and B type cell counts fell to the lowest point in the fifth month and increased again in the sixth month. The C and D type cells reached the lowest point in the fourth month in non-target organs but the D type cells then dramatically increased in the uterus, testes and liver. It was suggested that ER play an important role in human embryonic development and differentiation. The ER may influence proliferative ability of early embryonic organs and the late hormone-specific organ growth.
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589
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Whittemore AS, Wu-Williams AH, Lee M, Zheng S, Gallagher RP, Jiao DA, Zhou L, Wang XH, Chen K, Jung D. Diet, physical activity, and colorectal cancer among Chinese in North America and China. J Natl Cancer Inst 1990; 82:915-26. [PMID: 2342126 DOI: 10.1093/jnci/82.11.915] [Citation(s) in RCA: 251] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
In a population-based case-control study of colorectal cancer among Chinese men and women in western North America and the People's Republic of China, a common protocol was used to assess past life-style characteristics of 905 cases diagnosed during 1981-1986 and 2,488 controls. Risks for cancers of both the colon and rectum increased with increased food energy from fat, protein, carbohydrate, and all energy sources combined, for both sexes and on both continents. Yet, in multivariate analysis, colorectal cancer risk was significantly associated only with saturated fat; no relationships were seen with other dietary sources of energy. Colon cancer risk was elevated among men employed in sedentary occupations. On both continents and in both sexes, risks for cancers of both the colon and rectum increased with increasing time spent sitting. Further, the association between colorectal cancer risk and saturated fat was stronger among the sedentary than among the active. Risk among sedentary Chinese Americans of either sex increased more than fourfold from the lowest to the highest category of saturated fat intake. Among migrants to North America, risk increased with increasing years lived in North America. These observations suggest (a) that colorectal cancer risk increases with duration of exposure to a sedentary life-style and a diet rich in saturated fat; (b) that higher incidence among Chinese-American men relative to women is due to longer duration of these habits among men, who have lived longer in North America; and (c) that higher risk among Chinese Americans of both sexes relative to risk among the general population in China is due to differences in such habits. Attributable risk calculations suggest that, if these associations are causal, saturated fat intakes exceeding 10 g/day, particularly in combination with physical inactivity, could account for 60% of colorectal cancer incidence among Chinese-American men and 40% among Chinese-American women.
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590
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Renugopalakrishnan V, Zheng S, Tu AT, Damle SP. Secondary structure of pig skin proteodermatan sulfate: a perspective from Raman spectroscopic studies in aqueous solution. Biopolymers 1989; 28:1935-8. [PMID: 2597741 DOI: 10.1002/bip.360281110] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Raman spectroscopic studies of pig skin proteodermatan sulfate in H2O are indicative of a well defined secondary structure consisting of alpha-helical, beta-turn, and possibly "random" structures. The above conclusion is surprisingly close to the secondary structure of the "core" protein of pig skin proteodermatan sulfate proposed in the previous paper (V. Renugopalakrishnan et al., Biopolymers 28, 1923-1933, 1989) from FT-IR and CD spectroscopic studies in aqueous solution.
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591
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Aroonprasert D, Fagerland JA, Kelso NE, Zheng S, Woode GN. Cultivation and partial characterization of bovine astrovirus. Vet Microbiol 1989; 19:113-25. [PMID: 2495698 PMCID: PMC7117497 DOI: 10.1016/0378-1135(89)90077-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/1988] [Indexed: 01/01/2023]
Abstract
Bovine astrovirus serotype 2 (US2) was adapted to primary neonatal kidney cell (NBK) cultures by the addition of 50 micrograms ml-1 of trypsin in the medium. Infectious virus was released from the cells within 7 days post-infection in early passages and within 3 days in later passages. In the absence of trypsin, neither passage of infected cells nor release of infectious virus occurred. The virus was shown to be similar to the fecal astrovirus by a neutralization test and by ultrastructural studies of infected cells. Primary embryo bovine kidney (EBK) and NBK cell cultures supported infection with both fecal and tissue culture adapted (TCA) astrovirus. The time-related development of infection, as studied by immunofluorescence, was similar for both fecal and TCA astrovirus and for both cell culture types. The first indication of viral infection and expression of viral antigens occurred at 7 h post-infection and was characterized by the appearance of a diffuse faint immunofluorescence (IF) of the cytoplasm. Soon after, two or three brilliant IF granules were observed in the nucleus, which appeared to involve the nucleoli. Subsequently, dense granular IF was seen in the perinuclear region of the cytoplasm, which later extended to involve all the cytoplasmic area. In both EBK and NBK cultures infected with either fecal or tissue culture adapted astrovirus, only a minority of cells became infected, even when the multiplicity of infection exceeded one. Occasionally 10-20% of cells were infected, but in most cultures the proportion did not exceed 2% and in NBK cultures, from 3/9 calves, no infected cells were observed. The virus did not infect bovine cell lines. Infectivity of the virus was not removed by treatment with chloroform, and iododeoxyuridine and actinomycin D when added to the medium, did not block replication. Masses of virions were observed by electron microscopy in discrete areas in the cytoplasm, with similar distributions as the viral antigen foci as seen by IF. The mean diameter of the virions was 34 nm. In conclusion, bovine astrovirus lacks both essential lipids and an envelope, probably has an RNA genome, may have a nuclear phase of replication involving the nucleoli which is not blocked by DNA inhibitors, and has a selective cell tropism.
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592
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Woode GN, Zheng S, Melendy DR, Ramig RF. Studies on rotavirus homologous and heterologous active immunity in infant mice. Viral Immunol 1989; 2:127-32. [PMID: 2550022 DOI: 10.1089/vim.1989.2.127] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Homologous and heterologous active immunity was studied in mice with mammalian group A rotaviruses. One day old mice were vaccinated with one of the following rotaviruses: bovine B641 (serotype 6), bovine B223 (untyped), simian SA11 (serotype 3) and murine EDIM (untyped). At 10 days of age they were challenged with EDIM virulent virus or SA11 virus. All the vaccines induced a serological antibody response in the mice but only the homologous immune response was protective.
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593
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Zheng S, Liang ZC, Shao RF, Lam L, Cheng CW, Fung PC. Propagation of white ring-shaped solitons in nematic liquid crystals. PHYSICAL REVIEW. A, GENERAL PHYSICS 1988; 38:5941-5943. [PMID: 9900342 DOI: 10.1103/physreva.38.5941] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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594
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Borwanker CM, Pfeiffer SB, Zheng S, Beissinger RL, Wasan DT, Sehgal LR, Rosen AL. Formulation and Characterization of a Multiple Emulsion for Use as a Red Blood Cell Substitute. Biotechnol Prog 1988. [DOI: 10.1002/btpr.5420040404] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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595
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Zheng S. [Status of estrogen receptors in breast cancer and prediction of chemotherapy sensitivity]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1988; 10:157-61. [PMID: 2972402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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596
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Zheng S, Newton GL, Gonick G, Fahey RC, Ward JF. Radioprotection of DNA by thiols: relationship between the net charge on a thiol and its ability to protect DNA. Radiat Res 1988; 114:11-27. [PMID: 3127858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Release of free bases from calf thymus DNA upon irradiation in aerated 0.1 mol dm-3NaClO4 at pH 7 has been measured by HPLC and shown to be markedly influenced by the presence of thiols during irradiation. The ability of thiols to protect DNA was shown to depend upon the net charge (Z) at pH 7 in the order WR 1065 (Z = +2) greater than cysteamine (Z = +1) greater than 2-mercaptoethanol (Z = 0) approximately equal to dithiothreitol (Z = 0) greater than GSH (Z = -1) approximately equal to 2-mercaptoethanesulfonic acid (Z = -1) approximately equal to 2-mercaptosuccinate (Z = -2). A similar dependence of protection upon net charge was found for disulfides: cystamine (Z = +2) greater than 2-mercaptoethyl disulfide (Z = 0) greater than GSSG (Z = -2). Protection by WR 1065, but not by 2-mercaptoethanol or GSH, was found to decrease significantly with increasing ionic strength. Protection by WR 1065 and GSH was not markedly dependent upon pH between pH 6 and 8. The results are explained in terms of electrostatic interaction of the thiols with DNA, leading to high concentrations of cations near DNA, which allow them to scavenge hydroxyl radicals and repair DNA radicals effectively and to low concentrations of anionic thiols near DNA, which limit their effectiveness as protectors. Poly(dG,dC) and calf thymus DNA exhibited comparable release of G and C upon changing from 0.1 to 0.7 mol dm-3 MgSO4. Since this change causes poly(dG,dC), but not calf thymus DNA, to undergo a change from the B-form to the Z-form of DNA, both forms must have a comparable susceptibility to radiation-induced base release.
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597
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Zheng S, Tu AT, Renugopalakrishnan V, Strawich E, Glimcher MJ. A mixed beta-turn and beta-sheet structure for bovine tooth enamel amelogenin: Raman spectroscopic evidence. Biopolymers 1987; 26:1809-13. [PMID: 3663856 DOI: 10.1002/bip.360261012] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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598
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Gao YL, Zheng S. [Prevention and therapy of nausea and vomiting caused by antineoplastic agents]. ZHONGHUA FU CHAN KE ZA ZHI 1987; 22:51-3. [PMID: 3297548] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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599
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Zheng S, Fan MZ, Li SE. [Increase in a protein of Mr 53000 in the initiation-promotion system of chemical carcinogenesis in rat liver]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1986; 8:494-7. [PMID: 2954682] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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600
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Gao J, Shen H, Zheng S, Fan HM, Wu MH, Han LH, Yao GZ. A randomized comparative clinical evaluation of the Steel Ring, the VCu200 and the TCu220c IUDs. Contraception 1986; 33:443-54. [PMID: 3530634 DOI: 10.1016/s0010-7824(86)80003-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A randomized comparative clinical study of the Steel Ring, VCu200 and TCu220c IUDs was carried out in Beijing. Six-hundred subjects were recruited and each group of 200 was inserted with one of the three devices. The TCu220c and the VCu200 had statistically significantly lower pregnancy and expulsion rates at one and two years of use than the Steel Ring. However, the Steel Ring consistently had the lowest rate of removal for pain and/or bleeding. At two years, the early differences of use-related discontinuation and continuation between the higher rates of the Steel Ring and the lower rates of the VCu200 and TCu220c were significantly reduced. There were no statistically significant differences of net event rates between VCu200 and TCu220c.
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