601
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Yuan M, Ma Z. [Development and uses of porous-coated hip prostheses]. Zhonghua Wai Ke Za Zhi 1995; 33:445-8. [PMID: 8565739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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602
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Ma Z, Meddings JB, Lee SS. Cardiac plasma membrane physical properties and beta-adrenergic receptor function are unaltered in portal-hypertensive rats. Hepatology 1995; 22:188-93. [PMID: 7601411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/06/2022]
Abstract
We have previously demonstrated that impairment of cardiac contractility in a rat model of cirrhosis may be secondary to altered cardiac plasma membrane physical properties affecting beta-adrenergic receptor function. It is unclear whether this is caused by the cirrhosis or by the portal hypertension in this model, so we studied cardiomyocyte plasma membrane physical properties, lipid composition, and beta-adrenergic receptor function in a rat model of prehepatic portal hypertension without cirrhosis. Portal hypertension was induced by graded portal vein stenosis, whereas controls had a sham operation. Cardiac sarcolemmal plasma membrane physical properties were studied by fluorescent polarization methods using diphenylhexatriene and a series of anthroyloxy-stearic acids to estimate, respectively, the static and dynamic components of membrane fluidity. beta-Adrenergic receptor density and binding affinity were measured using 3H-dihydroalprenolol as a radioligand. Isoproterenol-stimulated adenylyl cyclase activity was measured by radioimmunoassay. Neither the static nor the dynamic components of membrane fluidity were significantly different in portal-hypertensive rats compared with the controls. The membrane cholesterol, phospholipid content, and the cholesterol/phospholipid ratio did not differ between the two groups. beta-Adrenergic receptor density and binding affinity in the portal-hypertensive rats (respectively, 1.65 +/- 0.06 pmol/mg protein and 6.78 +/- 0.80 nmol/L) were not different from controls (1.76 +/- 0.17 pmol/mg protein and 7.25 +/- 1.48 nmol/L). Isoproterenol-stimulated adenylyl cyclase activity in membranes from portal-hypertensive rats did not significantly differ from controls. We conclude that cardiac plasma membrane physical properties and beta-adrenoceptor function in portal hypertensive rats remains unimpaired, suggesting that the cardiomyopathy of cirrhosis is not caused by portal hypertension per se.
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Affiliation(s)
- Z Ma
- Liver Unit, University of Calgary, Canada
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603
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604
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Ma Z, Wang M, Wang W. [SIMA leakage into stroma and lymph node metastasis in cervical adenocarcinoma]. Zhonghua Bing Li Xue Za Zhi 1995; 24:168-9. [PMID: 7656385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The relationship of small intestine mucin antigen (SIMA) leakage into stroma and tumor lymph node metastasis was studied by SIMA immunohistochemical stain in the cervical adenocarcinoma of uterus. The results showed that the more SIMA leakage into stroma, the more possibility of lymph node metastasis. There was no difference between the SIMA staining intensity in the primary tumor or metastatic tumor. Mucin leakage into stroma may play an important role in cervical adenocarcinoma metastasis.
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Affiliation(s)
- Z Ma
- Department of Pathology, Shandong Provincial Hospital, Jinan
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605
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Ma Z, Li C, Lu H. [Lumbar spinal stenosis syndrome: classification, pathology and operative consideration]. Zhonghua Wai Ke Za Zhi 1995; 33:133-6. [PMID: 7555377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
A total of 168 cases of lumbar spinal stenosis syndrome were operated on in recent 6 years. They included 13 cases of developmental spinal stenosis and 155 cases of acquired spinal stenosis. All patients were followed up for an average of 2 years and 7 months, ranging from 3 months to 5 years and 10 months. The results of treatment were not satisfactory in developmental spinal stenosis (excellent 46.2%, good 30.7%, fair 15.4%, poor 7.7%), but good in acquired spinal stenosis (excellent 72.2%, good 22.6%, fair 5.2%, poor 0). Moreover, with different classification and pathology, acquired spinal stenosis had different results. The authors stressed that it is very important to consider the methods and the range of operation according to the pathological characteristics of myelography and CTM of lumbar spinal stenosis.
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Affiliation(s)
- Z Ma
- First Hospital of Beijing Medical University
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606
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Xu L, Qu C, Ma Z. [The effects of antitumor agents of croton alkaloids and cisplatin on human red blood cell membranes]. Zhonghua Zhong Liu Za Zhi 1995; 17:115-7. [PMID: 7656800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The effects of antitumor drugs of croton alkaloids (CA) extracted from croton, and cisplatin on the structure of human erythrocyte membrane and bovine serum albumin (BSA) were studied with the techniques of circular dichroism, fluorescence spectroscopy and ultraviolet absorption. From measuring circular dichroism between 200-240nm, it was found that the alpha helix of membrane and BSA increased after CA addition. Cisplatin was also found effective in altering membrane alpha helical content. BSA showed a loss of fluorescence intensity and a blue-shift of emission peak after CA addition. The florescence quenching and peak shift may reflect the movement of tryptophan to a more nonpolar environment (the hydrophobic portions of proteins). This is consistent with the increase in helicity of BSA in the presence of CA. From measuring fluorescence polarization of membrane, it was found that membrane fluidity decreased in the presence of CA, but did not change in the presence of cisplatin. The results indicate that both CA and cisplatin lead to alterations in the secondary structure of membrane protein. The conformation change in membrane protein may account for the pharmocological effect of CA and cisplatin.
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Affiliation(s)
- L Xu
- Huangdao Cancer Research Institute, Qingdao
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607
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Ma Z, Li H, Gao S. [Limb-salvage surgery in 60 patients with osteosarcoma]. Zhonghua Wai Ke Za Zhi 1995; 33:82-5. [PMID: 7656710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Limb-salvage surgery plays an important role in the treatment of osteosarcoma. From 1974 to 1993, 104 patients with osteosarcoma were treated in our department. Sixty of them were treated with limb-salvage procedures. In fourty-four patients of stage II B receiving adjuvant chemotherapy, the five-year survival rate was 46.69%. The overall local recurrence rate was 15%. The infection rate was 12.9%, and mechanical complication occurred in 14.8% of the patients. The functional result was generally good. Improved concepts of en bloc resection and better reconstructive techniques suggest that limb-salvage procedures are not only possible but can provide excellent functional result in patients with osteosarcoma. Further work must be directed to reducing local recurrence and improving reconstructive techniques.
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Affiliation(s)
- Z Ma
- First Hospital of Beijing Medical University
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608
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Tan Y, Lu W, Zhao S, Hu Y, Ma Z. [Rectal administration of ash bark]. Zhongguo Zhong Yao Za Zhi 1995; 20:92-4, 126. [PMID: 7779279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
A TLC-densitometric method was applied to determine aesculin in rabbit blood. The best way for ash bark rectal administration was found by orthogonal design [L4(2(3))]. The two routes of administration (per rectal, P.O.) were compared by bioavailabilities and the result indicated that per rectal was better than P.O. Modified isolated rectum-bag method was applied successfully to finding the best way for rectal administration of ash bark.
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Affiliation(s)
- Y Tan
- Jiangxi Institute of Traditional Chinese Medicine, Nanchang
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609
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Tan Y, Lu W, Zhao S, Hu Y, Ma Z. [Research on rectal administration of bark of official Magnolia]. Zhongguo Zhong Yao Za Zhi 1995; 20:30-2, 62. [PMID: 7626207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Fluorescence assay was applied to the determination of magnolol in rabbit blood, and the best way to administer the bark of official magnolia per rectal was established by orthogonal test. Then the two routes of administration were compared by AUC of magnolol and per rectal was found better than P.O. In addition, the modified isolated rectum-bag method was applied successfully to the research on rectal administration of bark of official magnolia.
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Affiliation(s)
- Y Tan
- Jiangxi Institute of Traditional Chinese Medicine, Nanchang
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610
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Chang MX, Yao CY, Liu XP, Ma Z, Liu JX, Huang DY. [Bacteriostasis of rhizoma Coptidis combined with trimethoprim (TMPO)]. Zhongguo Zhong Yao Za Zhi 1994; 19:748-9, 764. [PMID: 7718141] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The agar-dilution method was adopted to study contrastively the bacteriostasis of Rhizoma Coptidis and TMP, and also of the two drugs in combination. The results indicate that the combination works in good cooperation against Escherichia coli, Bacillus pyocyaneus, Staphylococcus aureus, Shigella flexneri and S. dysenteriae.
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Affiliation(s)
- M X Chang
- Affiliated Hospital, Hubei College of Traditional Chinese Medicine, Wuhan
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611
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Ma Z, Shi H, Chen B. Isovector meson contribution in the relativistic Hartree-Fock approach for finite nuclei. Phys Rev C Nucl Phys 1994; 50:3170-3173. [PMID: 9970024 DOI: 10.1103/physrevc.50.3170] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
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612
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Kobe B, Ma Z, Deisenhofer J. Complex between bovine ribonuclease A and porcine ribonuclease inhibitor crystallizes in a similar unit cell as free ribonuclease inhibitor. J Mol Biol 1994; 241:288-91. [PMID: 8057371 DOI: 10.1006/jmbi.1994.1502] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
We obtained three different morphologies of co-crystals of bovine ribonuclease A and porcine ribonuclease inhibitor. X-ray quality crystals were grown in 1.3M ammonium sulfate, 100 mM sodium acetate (pH 5.0) and 20 mM dithiothreitol at 21 degrees C. These crystals have the symmetry of the tetragonal space group I4 with a = 133.3 A and c = 86.7 A and diffract to 2.5 A resolution; they have the same symmetry and only slightly different cell parameters than the crystals of free ribonuclease inhibitor. Polyacrylamide gel electrophoresis and the crystal density indicate that both ribonuclease inhibitor and ribonuclease A are present in the crystals. Although small, crystals are suitable for three-dimensional structural analysis.
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Affiliation(s)
- B Kobe
- Howard Hughes Medical Institute, University of Texas, Southwestern Medical Center, Dallas 75235-9050
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613
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Abstract
Studies of several population-toxicant models are discussed. Under the hypothesis that the exogenous input of toxicant into the environment is periodic in time, the conditions for permanence of populations are obtained.
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Affiliation(s)
- W Wang
- Department of Mathematics, Southwest Normal University, Chongquing, People's Republic of China
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614
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Ma Z, Liaw K. Education selectivity in internal migration in mainland China. Ingu munje nonjip 1994:135-59. [PMID: 12222452] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
"The purpose of this paper is to study the selectivity in...internal migration in Mainland China with respect to the level of education, based on a sample of young adults (aged 17-29) taken from the micro data of the 1987 one-percent National Population Survey (NPS87)....[We focus first] on the education selectivity in migrations among the city, town and rural strata of the urban/rural hierarchy [and then examine] the education selectivity in migration among metropolitan, coastal and interior regions." (SUMMARY IN CHI)
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615
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Abstract
To elucidate the basic membrane mechanisms underlying cirrhotic cardiomyopathy, cardiac sarcolemmal plasma membrane physical properties, chemical composition, beta-adrenoceptor density, binding affinity, and isoproterenol-stimulated adenosine 3',5'-cyclic monophosphate (cAMP) production were studied. Cirrhosis was induced by chronic bile duct ligation, while controls underwent a sham operation. The cardiac plasma membrane of cirrhotic rats was found to be more rigid than controls, primarily due to an increased cholesterol-to-phospholipid ratio. In cirrhotic animals, beta-adrenergic dysfunction was evident with a 21% decrease in beta-adrenoceptor density but no alteration in binding affinity. Despite the modest decrease in receptor number, beta-adrenoceptor-stimulated cAMP production was decreased by 37% in cirrhotic rats. When the membrane physical properties of the cirrhotic rats were restored to normal, by incubation with the fluidizing agent 2-(2-methoxy-ethoxy)ethyl 8-(cis-2-n-octylcyclopropyl)octanoate (A2C), isoproterenol-stimulated cAMP production also increased to levels indistinguishable from control animals. Restoration of membrane physical properties had no effect on either beta-adrenoceptor density or binding affinity. These results suggest that the increased rigidity of cardiomyocyte plasma membranes seen with cirrhosis is associated with decreased beta-adrenoceptor function. Moreover, restoring normal physical properties may result in restoration of beta-adrenoceptor-mediated contractile function.
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Affiliation(s)
- Z Ma
- Gastroenterology Research Group, University of Calgary, Alberta, Canada
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616
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Abstract
The clinical signs of camel sway disease in the Hexi Corridor of Gansu province were defined. The contents of eight minerals in soils, in forage and in the blood and hair of bactrian camels from this region were determined. The related blood indices were also measured. The concentration of molybdenum in soils and forage was 4.8 +/- 0.02 and 4.8 +/- 0.25 micrograms/g (dry matter), respectively, the copper to molybdenum ratio in the forage being only 1.3. The concentration of copper in blood and hair from the camels was 0.28 +/- 0.17 micrograms/ml and 3.50 +/- 1.00 micrograms/g, respectively. There was a hypochromic microcytic anaemia and a low level of ceruloplasmin in the blood. It is therefore suggested that sway disease of bactrian camels in this region is caused by secondary copper deficiency, mainly due to the high molybdenum content in soils and forage. The copper deficiency in the camels was aggravated during reproduction. Oral administration of copper sulphate can prevent and cure the disease.
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Affiliation(s)
- Z P Liu
- Department of Veterinary Medicine, Gansu Agricultural University, People's Republic of China
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617
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Ma Z, Liu K, Harding LB, Komotos M, Schatz GC. Differential cross sections for fine structure transitions in O(3P2)+Ar collisions. J Chem Phys 1994. [DOI: 10.1063/1.466796] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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618
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Ma Z, Allen LH. Kinetic mechanisms of the C49-to-C54 polymorphic transformation in titanium disilicide thin films: A microstructure-scaled nucleation-mode transition. Phys Rev B Condens Matter 1994; 49:13501-13511. [PMID: 10010286 DOI: 10.1103/physrevb.49.13501] [Citation(s) in RCA: 131] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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619
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Ma Z, Allen LH. Low-temperature structure and phase transitions at the Au/Si (100) interface. Phys Rev B Condens Matter 1993; 48:15484-15487. [PMID: 10008097 DOI: 10.1103/physrevb.48.15484] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/12/2023]
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620
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Ma Z, Taber RC, Lombardo LW, Kapitulnik A, Beasley MR, Merchant P, Eom CB, Hou SY, Phillips JM. Microwave penetration depth measurements on Bi2Sr2CaCu2O8 single crystals and YBa2Cu3O7- delta thin films. Phys Rev Lett 1993; 71:781-784. [PMID: 10055365 DOI: 10.1103/physrevlett.71.781] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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621
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Abstract
At high concentrations, one boundary (the front if the isotherm is convex upward) of the elution band of a single component becomes very steep. Similarly, in frontal analysis, the same boundary is self-sharpening. These steep boundaries are called shock layers. They result from the steady-state equilibrium between a nonlinear thermodynamics of phase equilibrium on the one hand, which tends to create a concentration discontinuity, and axial dispersion and a finite rate of mass transfer on the other hand, which tend to relax the concentration gradient. We show that the width of experimental breakthrough curves recorded in frontal analysis agrees well with the prediction of the shock layer theory of Rhee and Amundson in the high concentration range. It is a function of the coefficients of the column HETP equation and the height of the concentration step and is independent of the column length, after the steady state is achieved. In the low concentration range, a discrepancy is observed when the column length is short and the migration distance is insufficient to achieve constant pattern behavior.
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Affiliation(s)
- J Zhu
- Department of Chemistry, University of Tennessee, Knoxville 37996-1501
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622
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Abstract
Plasma-sprayed hydroxyapatite coatings contain a quite large amount of amorphous phase. Infrared analysis shows that the plasma-sprayed amorphous phase is an oxyapatite and the coating predetermined as a hydroxyapatite is proved to be an oxyhydroxyapatite with a small quantity of hydroxyapatite. Heat treatment promotes the transformation of amorphous oxyapatite into a crystalline hydroxyapatite structure and reduces the dissolution rate of the coatings. Further studies focus on the properties of the amorphous phase, showing that amorphous oxyapatite is more soluble in 0.15 M lactic acid at 25 degrees C and that water molecules can accelerate the amorphous/crystalline transformation of the hydroxyapatite structure during the plasma-spraying process.
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Affiliation(s)
- J Weng
- Institute of Materials Science and Technology, Sichuan University, Chengdu, People's Republic of China
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623
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Ma Z, Dayananda M. An investigation of phase relations in TiAl(Nb+V+Mo) system at 1100°C using solid state diffusion technique. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0956-716x(93)90078-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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624
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Abstract
It is shown that under standard conditions of plasma spraying hydroxyapatite powder reaches the substrate in the form of molten drops. On striking the surface, the molten drop splatters, cools rapidly and solidifies. Consequently, a pancake particle surrounded by tiny spherical or differently shaped particles is formed on the substrate. The solidified particles are partly crystallized. Besides the crystalline hydroxyapatite, they contain some supercooled molten hydroxyapatite, i.e. amorphous hydroxyapatite. Build-up of these particles during coating gives a porous pancake-globular structure. During a brief vacuum heating at 630 degrees C, the amorphous phase is crystallized and completely crystalline hydroxyapatite coatings are obtained.
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Affiliation(s)
- Z Zyman
- General Physics Department, Physics Faculty, Kharkov State University, Ukraine
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625
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Bi W, Rao JY, Hemstreet GP, Fang P, Asal NR, Zang M, Min KW, Ma Z, Lee E, Li G. Field molecular epidemiology. Feasibility of monitoring for the malignant bladder cell phenotype in a benzidine-exposed occupational cohort. J Occup Med 1993; 35:20-7. [PMID: 7678643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Modern molecular and cellular biology have provided powerful new approaches to study cancer in the research laboratory, but these techniques have not been used extensively in field studies or in screening of high-risk occupational cohorts. The primary objective of this study was to demonstrate the use of cellular and molecular methods in combination with medical and epidemiologic methods to identify cancer cases, risk factors, and markers in a previously identified and defined cohort of Chinese workers exposed to benzidine. The screening of exposed workers included occupational, medical, and smoking histories to identify exogenous risk factors, a limited physical examination, Papanicolaou (PAP) urinary cytology, measurement of urine pH, quantitative fluorescence image analysis (QFIA) cytology to detect DNA hyperploidy, and quantitative fluorescence to detect expression of a low-grade bladder tumor-associated antigen (p300) by exfoliated urothelial cells and elevated expression of the neu oncogene product (p185). Detailed analysis of the accuracy of epidemiologic data and the adequacy of samples and accuracy of molecular techniques was carried out. Three groups were included in this study: group 1 included 23 bladder cancer cases who had previously been exposed to benzidine and served as two surrogates for late-emerging disease; group 2 consisted of 20 subjects with previous exposure history but not previously diagnosed with bladder cancer; and group 0 was the nonexposure and nonbladder cancer controls. The results showed that accurate questionnaire data and urine samples can be obtained at remote sites. Among the 20 group 2 subjects, two displayed abnormal findings by both QFIA cytology and p300 expression and were later confirmed to have bladder cancer.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- W Bi
- Department of Toxicology and Epidemiology, Chinese Academy of Preventive Medicine, Beijing
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626
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Pal PK, Ma Z, Coleman PS. The AMP-binding domain on adenylate kinase. Evidence for a conformational change during binary-to-ternary complex formation via photoaffinity labeling analyses. J Biol Chem 1992; 267:25003-9. [PMID: 1460003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The topological location of the nucleotide substrate binding environments on adenylate kinase has been explored with the fluorescent molecule [4-benzoyl]benzoyl-1-amidofluorescein (BzAF) and the nucleotide analog 3'-O-[4-benzoyl]benzoyl-ATP (BzATP), which are site-directed photoaffinity probes that bind covalently at the individual nucleotide sites. The MgBzATP substituted for MgATP as a substrate for this enzyme, whereas BzAF, which is neither a substrate nor a nucleotide, behaved as a competitive inhibitor for each nucleotide site independently. BzAF could be directed specifically to either of the nucleotide sites by near saturation of the second site with its natural nucleotide substrate. Using this second site blocking approach, each nucleotide site, in turn, could be protected competitively from BzAF-induced photoinhibition by the presence of its natural substrate. This strategy showed that under photolysis, the Kd(BzAF) of 0.1 mM (for the MgATP site) and 0.2 mM (for the AMP site) were nearly identical with the Km(app) values determined for MgATP and AMP, respectively. Pseudo first-order photolysis kinetics with [3H]BzAF revealed covalent binding stoichiometries for full inhibition of 1 mol of probe/mol of enzyme at either site. Thus, we prepared the binary complex ([3H]BzAF-enzyme) by photo-labeling the MgATP site-blocked enzyme with [3H]BzAf to 1:1 molar stoichiometry. Tryptic digestion followed by partial sequencing of the [3H]BzAF-labeled enzyme disclosed that BzAF was bound specifically within the peptide span Gly64-->Arg77. This amino acid domain therefore probably constitutes the neighborhood identifiable with AMP binding. Furthermore, we also achieved double photocovalent labeling of adenylate kinase with both photoprobes, by first cross-linking with approximately 1 mol of MgBzATP, followed by approximately 0.9 mol of [3H]BzAF, thus generating a ternary covalent complex. Comparison of the fluorescence of the binary species and the ternary (BzATP-enzyme-[3H]BzAF) complex revealed altered fluorescence emission profiles, which could indicate that a conformational change occurs during formation of the ternary (or transition state) complex.
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Affiliation(s)
- P K Pal
- Boston Biomedical Research Institute, Massachusetts 02114
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627
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Pal P, Ma Z, Coleman P. The AMP-binding domain on adenylate kinase. Evidence for a conformational change during binary-to-ternary complex formation via photoaffinity labeling analyses. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)73997-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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628
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Ma Z, Grubb JH, Sly WS. Divalent cation-dependent stimulation of ligand binding to the 46-kDa mannose 6-phosphate receptor correlates with divalent cation-dependent tetramerization. J Biol Chem 1992; 267:19017-22. [PMID: 1326539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The quaternary structure and binding activity of the murine 46-kDa mannose 6-phosphate receptor (46MPR) were studied in semi-intact murine cells that overexpress the murine receptor. Chemical cross-linking studies showed that the murine 46MPR exists in monomer, dimer, and tetramer forms in membranes of overexpressing murine cells. Treatment of permeabilized cells with Mn2+ increased the tetramer form of 46MPR, and this tetramerization was reversed by removal of Mn2+. Thus, the divalent cations affected the distribution of receptor among the three forms, favoring tetramerization at the expense of dimer and monomer. Low temperature (4 degrees C) also increases the fraction present as tetramer. The binding assay results show that Mn2+ is required for the 46MPR to achieve and retain the ability to bind ligand at 37 degrees C but not at 4 degrees C. Preincubation with Mn2+ produced a 3-fold increase in Man-6-P-specific binding of beta-glucuronidase which paralleled the 3-fold increase in tetramer seen during preincubation with Mn2+. The similarity of the effects of addition and removal of Mn2+ on enzyme binding to the effects of Mn2+ on favoring tetramer formation suggests that divalent cation-dependent tetramerization of the 46MPR contributes to the stimulation of ligand binding to the 46MPR by divalent cations.
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Affiliation(s)
- Z Ma
- Edward A. Doisy Department of Biochemistry and Molecular Biology, St. Louis University School of Medicine, Missouri 63104
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629
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Ma Z, Grubb J, Sly W. Divalent cation-dependent stimulation of ligand binding to the 46-kDa mannose 6-phosphate receptor correlates with divalent cation-dependent tetramerization. J Biol Chem 1992. [DOI: 10.1016/s0021-9258(19)37062-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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630
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Abstract
BACKGROUND AND METHODS A new mode of jet ventilation, high-frequency two-way jet ventilation, was devised and introduced to increase CO2 elimination. High-frequency two-way jet ventilation was achieved by adding reverse jet pulses inside the trachea through an intratracheal reverse jet system to the expiratory phase of common high-frequency jet ventilation. The ventilatory efficiency and features of high-frequency two-way jet ventilation were investigated and compared with those features of high-frequency jet ventilation in ten dogs in the same experimental condition. Random sample selection and randomized crossover trial were used for comparison between high-frequency two-way jet ventilation and high-frequency jet ventilation. Peak inspiratory pressure, end-expiratory pressure, and the arterial blood gas variables (PaO2, PaCO2, and pH) were measured during the study. RESULTS PaCO2 with high-frequency two-way jet ventilation was about 35% lower than that with high-frequency jet ventilation (from 45 to 29 torr [6.0 to 3.9 kPa], p less than .01). Simultaneously, peak inspiratory pressure and end-expiratory pressure during high-frequency two-way jet ventilation were significantly lower than those same variables measured during high-frequency jet ventilation. End-expiratory pressure of high-frequency two-way jet ventilation was a negative pressure (-2.45 +/- 0.45 cm H2O). The pH of high-frequency two-way jet ventilation was significantly higher than that of high-frequency jet ventilation. CONCLUSIONS Compared with high-frequency jet ventilation, high-frequency two-way jet ventilation demonstrated a ventilatory feature of increasing CO2 elimination and simultaneously decreasing airway pressure.
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Affiliation(s)
- H Wei
- Department of Anesthesiology, Tongji Hospital, Tongji Medical University, Wuhan, Hubei, China
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631
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Xie Z, Huang L, Ma Z. Personal characteristics of Chinese children and their discrepancies: a report on children's development in Anhui (I). Chin J Popul Sci 1992; 4:295-307. [PMID: 12318209] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
The authors report on a 1990 survey on the characteristics of children in China which included 1,000 primary school pupils in Anhui Province. The focus is on differences between only children and those with brothers or sisters. The results suggest that "the development of temperaments, moral character, behavior and basic ability of primary school pupils in Anhui is generally healthy despite certain discrepancies among different types of children."
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632
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Abstract
The effects of toxicants on naturally stable two-species communities are studied. Persistence-extinction thresholds are given for populations in the toxicant stressed Lotka-Volterra model of two interacting species. The threshold results are expressed in terms of relationships involving the population intrinsic growth rates, dose-response parameters, and interaction rates.
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Affiliation(s)
- H P Liu
- Department of Applied Mathematics, North Western Polytechnical University, Xi'an, People's Republic of China
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633
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634
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Ma Z. [Observation on the epidemiologic efficacy for 9 years on epidemic meningococcal polysaccharide vaccine of group A by district immunization method]. Zhonghua Liu Xing Bing Xue Za Zhi 1991; 12:69-71. [PMID: 2065343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
According to previous studies, there might be a peak of epidemic meningitis in Baoding City in 1984. For preventing the epidemic, we carried out vaccination with meningococcal polysaccharide vaccine by district immunization method during the 1980-1984 and then vaccination only to the children aged 12-24 months every year. The vaccination rate was 80.01% in 1980-1984 and was 97.15% in 1985-1988. During the 9 years, 833,377 children of vaccination group were observed, 4 of whom developed this disease, with an incidence of 0.48/100,000; and 304,085 children in the control group were observed, 25 of whom contracted this illness, with an incidence of 8.22/100,000. The protective rate of vaccine was 94.16% and the efficacy index was 1:17.12. This result showed that peak year of epidemic meningitis predicted in 1984 was prevented by vaccine immunization and the incidence of this disease was continuously kept less than 1/100,000 for 9 years.
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Affiliation(s)
- Z Ma
- Baoding Hygiene and Epidemic Prevention Station, Hebei Province
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635
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Hou J, Liu S, Ma Z, Lang X, Wang J, Wang J, Liang Z. Effects of gynostemma pentaphyllum makino on the immunological function of cancer patients. J TRADIT CHIN MED 1991; 11:47-52. [PMID: 1861511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- J Hou
- Institute of Oncology of Hebei Province
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636
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Zeng Y, Li X, Ma Z. A Chinese female postnuptial leaving home model--a procedure for analyzing main parameters alpha and beta in the setting up, testing and estimation of the model. Chin J Popul Sci 1991; 3:205-18. [PMID: 12285522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
"The first section of this article...sets up a model for leaving home after marriage that is suited to China's situation. The second section performs a statistical test and verification of the formulated model for leaving home after marriage. The third section...proposes a method for analyzing the main parameters...in the model...." The model is set up along the lines of the Brass-Gompertz relational fertility model.
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637
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Ma Z. [Into the society: analysis of 107 cases of tumor patients]. Zhonghua Hu Li Za Zhi 1990; 25:563-4. [PMID: 2276211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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638
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639
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Jiang YQ, Du XX, Guo SY, Ma Z. Intestinal metaplasia and gastric carcinoma. A histochemical and immunohistochemical study. Chin Med J (Engl) 1990; 103:821-5. [PMID: 2125255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
This article sums up the histochemical and immunohistochemical study of 55 cases of gastric carcinoma and 21 controls with benign gastric lesions. The results showed most of the adjacent mucosa of gastric carcinoma developed incomplete type intestinal metaplasia (IM). The percentage of Type IIb (ie, secreting sulphomucin) reached 72.5%. In most cases, high iron diamine (HID) rose in cancerous tissue and concomitantly in the IM epithelium of the adjacent gastric carcinoma. The phenomena of separation condition of HID+ in cancerous tissue, HID- in IM epithelium surrounding carcinoma, or HID- in cancerous cell but HID+ in IM of the surrounding epithelium of carcinoma, were much fewer. The two kinds of mucin antigen distribution were observed simultaneously. In the control and gastric carcinoma groups, neither large intestinal mucin antigen (LIMA) nor small intestinal mucin antigen (SIMA) could be detected in the normal epithelium of gastric mucosa. SIMA was mainly found in the goblet cells of IM and the mucous cells of columnar epithelium, while LIMA was mainly present in the columnar cells, in luminal border and/or in goblet cells. LIMA in the carcinoma group is apparently higher than that in the controls. The percentage of LIMA+ in the IM epithelium of adjacent gastric carcinoma and that in carcinoma cells were also raised in most cases. All these demonstrated a close relationship between IM and gastric carcinoma. Our results also showed that not only HID+, but also LIMA+ may represent a precancerous lesion in gastric carcinoma.
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Affiliation(s)
- Y Q Jiang
- Department of Pathology, Shanghai Second Medical University
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640
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Zhou Y, Ma Z, Li Y, Pan L, Xu G, Xu L, Yu G, Li P. [Investigation on resources of the Chinese drug beimu in Gansu Province]. Zhongguo Zhong Yao Za Zhi 1990; 15:515-6, 575. [PMID: 2092708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Based on a resources investigation and taxonomic research on the medicinal plants of Fritillaria from Gansu Province. Nine species one variety and one cultivation variety have been reported. Records and distribution of the species, together with a key for the species and a key for the powdered drug have been furnished as well.
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Affiliation(s)
- Y Zhou
- China Pharmaceutical University, Nanjing
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641
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Abstract
Models of the persistence and extinction of a population or community in a polluted environment have been investigated in several papers. But all of those papers have a basic assumption that the capacity of the environment is so large that the change of toxicants in the environment that comes from uptake and egestion by the organisms can be neglected. This assumption is not made in this article. Some sufficient conditions on persistence or extinction of a population have been obtained, and the threshold between the two has also been obtained for most situations.
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Affiliation(s)
- Z Ma
- Department of Mathematics, Xi'an Jiaotong University, China
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642
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Cheng T, Li T, Duan Z, Cao Z, Ma Z, Zhang P. [Acute toxicity of flesh oil of Hippophae rhamnoides L. and its protection against experimental hepatic injury]. Zhongguo Zhong Yao Za Zhi 1990; 15:45-7, 64. [PMID: 2350427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Protection by flesh oil of Hippophae rhamnoides against hepatotoxicity induced by CCl4 and acetaminophen (AAP) is reported in this paper. It was found that the oil markedly inhibited MDA formation of liver induced by CCl4 and AAP, decreased sGPT levels induced by CCl4 and blocked depletion of GSH damaged liver induced by AAP.LD50 greater than 45.0 g/kg.
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643
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Zhou L, Yang W, Xu Y, Zhu Q, Ma Z, Zhu T, Ge X, Gao J. [Short-term curative effect of cultured Cordyceps sinensis (Berk.) Sacc. Mycelia in chronic hepatitis B]. Zhongguo Zhong Yao Za Zhi 1990; 15:53-5, 65. [PMID: 1693509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
33 cases of chronic hepatitis B. patients treated with cultured Cordyceps sinensis mycelia have shown that the drug improves the liver function, promotes negative transfer HBsAg, and markedly helps to raise plasma albumin, resist high gamma globulin and to adjust body immunocompetence. It is therefore suggested that cultured Cordyceps sinensis mycelia may be used as a medicine for chronic hepatitis B. patients in adjusting protein metabolism and correcting inversion of albumin and globulin.
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Affiliation(s)
- L Zhou
- Shanxi Liver Diseases Research Co-operation Group
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644
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Abstract
A several millisecond pulsewidth pulsed Nd:YAG laser with output power of 200 W average and 5000 W peak is developed, and its performance is investigated. The experimental results are taken as a guide to designing and constructing a long-pulsewidth pulsed laser with high average output power.
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645
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Jiang YQ, Du XX, Guo SY, Ma Z. Mucous cell carcinoma of the stomach. A histochemical and immunohistochemical study of 50 cases. Chin Med J (Engl) 1988; 101:241-4. [PMID: 2843326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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646
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Gan PZ, Zhou DH, Yao RH, Ma Z, Ma RS, Xiang LZ, Huang LS. [Synthesis of indanones and tetralones as new potential schistosomicidals]. Yao Xue Xue Bao 1985; 20:345-52. [PMID: 4083021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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647
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Ma Z. [The characteristics of population growth of the Dongxiang nationality and the necessity of carrying out family planning]. Renkou Yanjiu 1983:41-3. [PMID: 12279806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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648
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Ma Z, Si BX, Huang LS. [Synthesis of esters of niridazolylmethanol (author's transl)]. Yao Xue Xue Bao 1981; 16:793-5. [PMID: 7336942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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649
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Huang LS, Wang A, Ma Z, Si BX. [Synthesis of a new schistosomicide S72014 and its homologs (author's transl)]. Yao Xue Xue Bao 1980; 15:346-50. [PMID: 6779503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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