751
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Yan L, Lei Z, Cui X, Chen H, Yang Y, Li L, Tan J, Chen L, Wu H, Li K. [The role of hemorheologic disturbance in experimental acute pancreatitis]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1993; 24:71-74. [PMID: 7687985] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
The role of hemorheologic disturbance in experimental acute pancreatitis was studied in Wistar male rats. It was found that pancreatic duct obstruction with secretin stimulation could induce acute interstitial pancreatitis (AIP), but when high molecular dextran intravenous injection being added, acute necrotizing pancreatitis (ANP) was induced. The authors suggest that the high molecular dextran can increase blood viscosity, aggregation of erythrocytes and decrease erythrocyte deformability, which results in pancreatic microcirculatory disturbances and promotes progressive pancreatic necrosis. Hemorheologic disturbance is one of the key factors in the pathogenesis of ANP.
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752
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Yan L, Spallholz JE. Generation of reactive oxygen species from the reaction of selenium compounds with thiols and mammary tumor cells. Biochem Pharmacol 1993; 45:429-37. [PMID: 8382065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Sodium selenite, sodium selenate, selenocystine and selenomethionine were tested for their abilities to generate superoxide by the oxidation of glutathione and other thiols in the absence and presence of cells of the human mammary tumor cell line HTB123/DU4475. Free radical generation was measured by lucigenin- or luminol-amplified chemiluminescence. In the absence of tumor cells, lucigenin-dependent chemiluminescence was observed from the reaction of selenite with the thiols glutathione, 2-mercaptoethanol and L-cysteine, but not with oxidized glutathione. Superoxide dismutase, catalase, and glutathione peroxidase all suppressed the observed chemiluminescence; but when these enzymes were heat inactivated they had little suppressive inhibition on chemiluminescence. Luminol-dependent chemiluminescence from the reaction of selenite with glutathione was much less than that observed by lucigenin-amplified chemiluminescence. In the presence of the HTB123/DU4475 mammary tumor cells, lucigenin-dependent chemiluminescence was observed from the reactions of selenite and selenocystine with glutathione which were 5 and 23 times greater than their respective reactions with glutathione in the absence of tumor cells. The enhanced chemiluminescence generated by selenite and selenocystine in the presence of the tumor cells was also suppressed by superoxide dismutase, catalase and glutathione peroxidase. These data suggest that a free radical, the superoxide anion (O2-), and H2O2 are produced from the reaction of selenite and selenocystine with glutathione. These free radical reactions may account for the toxicity of selenite and selenocystine in vitro in comparison to a near absence of acute tumor cell toxicity and superoxide generation by selenate and selenomethionine with thiols. Enhanced chemiluminescence in the presence of tumor cells may be an expression of cellular selenium metabolism and the capability of cells to form selenium metabolites that more easily oxidize glutathione and other thiols producing reactive free radicals and peroxides.
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753
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Fox JG, Blanco MC, Yan L, Shames B, Polidoro D, Dewhirst FE, Paster BJ. Role of gastric pH in isolation of Helicobacter mustelae from the feces of ferrets. Gastroenterology 1993; 104:86-92. [PMID: 8380398 DOI: 10.1016/0016-5085(93)90839-5] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
BACKGROUND Helicobacter mustelae colonizes the gastric mucosa of ferrets and causes persistent chronic gastritis. METHODS Hypochlorhydria, as measured by gastric pH probe, was induced by administering oral omeprazole, a proton pump inhibitor of the parietal cell, to adult ferrets in two separate experiments. Feces of ferrets were cultured for H. mustelae before, during, and after omeprazole therapy. RESULTS H. mustelae was isolated in 23 of 55 (41.8%) sequential fecal samples collected during omeprazole therapy. The same ferrets with acidic gastric pH had H. mustelae isolated in 6 of 62 (9.7%) of the fecal cultures (P < 0.01). A DNA species-specific H. mustelae probe confirmed the presence of the organism in both the stomach and feces of all 5 ferrets. In 4 of 5 ferrets restriction enzyme patterns of the gastric H. mustelae were identical to those of the fecal H. mustelae strains. CONCLUSIONS Hypochlorhydria promotes fecal transmission of a gastric Helicobacter organism. The H. mustelae-colonized ferret provides an ideal model to study the epidemiology and pathogenesis of Helicobacter pylori-induced gastritis.
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754
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Zhang G, Li W, Yan L, Yang Z, Chen X, Zheng T, Ye G. An epidemiological survey of deformities and disabilities among 14257 leprosy patients in 11 counties. CHINESE MEDICAL SCIENCES JOURNAL = CHUNG-KUO I HSUEH K'O HSUEH TSA CHIH 1992; 7:216-20. [PMID: 1307497] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This study was planned and conducted in 11 counties in Yangzhou Prefecture, which had formerly had a high prevalence of leprosy. Out of 14257 leprosy patients, 8122 (56.97%) with permanent deformities and disabilities were found. The disability rate was much higher among patients with multibacillary (MB) leprosy (81.15%) than among those with paucibacillary (PB) leprosy (53.04%). The statistical data involving the patients and the types of deformities and disabilities are presented in this paper, and the influences of various host factors and disease factors are discussed.
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755
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Yan L, Frenkel GD. Inhibition of cell attachment by selenite. Cancer Res 1992; 52:5803-7. [PMID: 1394206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Brief pre-exposure of HeLa cells to micromolar concentrations of selenite resulted in a dose-dependent decrease in the rate of their subsequent attachment to a solid matrix (tissue culture dish). Similar low concentrations of selenite also inhibited colony formation, but only when the cells were exposed prior to their attaching to the dish, not when they were exposed after attachment. This indicates that inhibition of cell proliferation by selenite requires exposure to higher concentrations for longer periods of time. In contrast, selenate, selenomethionine, selenocystine, and sulfite did not affect cell attachment, even at significantly higher concentrations. Thus, the inhibition of cell attachment is a specific effect of selenite. Selenite also inhibited the attachment of cells to bacteriological dishes coated with fibronectin, laminin, or collagen, proteins that are components of the extracellular matrix. There was no inhibition when the tissue culture dishes or the protein-coated dishes were pre-exposed to selenite. There was also no inhibition when the cells were exposed to selenite during the attachment process. Thus, pre-exposure of the cells to selenite was necessary for inhibition of attachment. Since cell attachment has been shown to be an important early step in tumor cell invasion and metastasis, these results suggest a novel mechanism of the anticarcinogenic effect of selenite: inhibition of the attachment of tumor cells to the extracellular matrix.
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756
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Lin JS, Jones WE, Yan L, Wirthwein KA, Flaherty EE, Haivanis RM, Rice PA. Underdiagnosis of Chlamydia trachomatis infection. Diagnostic limitations in patients with low-level infection. Sex Transm Dis 1992; 19:259-65. [PMID: 1411841 DOI: 10.1097/00007435-199209000-00004] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
To determine limitations in commonly used methods for detection of Chlamydia trachomatis, 601 genitourinary specimens from patients in a sexually transmitted disease clinic were examined with quantitative cultures and by 2 different direct antigen tests, immunofluorescence (Micro Trak; Syva Company, Palo Alto, CA) and enzyme immunoassay (Chlamydiazyme; Abbott Laboratories, North Chicago, IL). Genital specimens were held no longer than 5 hours (at 4 degrees C) prior to inoculation for culture; 28% (168/601) were positive. To evaluate the effect of storage on culture efficacy, duplicate specimens were also stored at -70 degrees C and brought out subsequently for culture a second time. Only 32% (8/25) of specimens cultured within 5 hours and having less than 10 inclusions were positive on reculture, compared with 98% (49/50) positive for specimens with greater than or equal to 10 inclusions initially (P less than 0.001). Sensitivities of the two antigen tests were similar and taken together diminished significantly (P less than 0.001) as the number of organisms (inclusion forming units) in corresponding cultures decreased: 82% (51/62) sensitivity in cultures with greater than 100 inclusions; 50% (22/44) with 10-100 inclusions; and only 11% (6/53) with less than 10. Lack of urethral discharge in men with C. trachomatis infection (free of Neisseria gonorrhoeae) was associated with low numbers of inclusions (less than 10) and antigen tests failed in 68% (15/22) of these patients.
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757
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Yan L, Swanson P, Dickhoff WW. A two-receptor model for salmon gonadotropins (GTH I and GTH II). Biol Reprod 1992; 47:418-27. [PMID: 1511095 DOI: 10.1095/biolreprod47.3.418] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The possible existence of distinct receptors for salmon gonadotropins (GTH I and GTH II) and the distribution of the receptor(s) were studied through examination of the binding of coho salmon (Oncorhynchus kistuch) GTH I and GTH II to membranes from thecal layers and granulosa cells of salmon ovaries. Purified coho salmon gonadotropins were iodinated by the lactoperoxidase method. Crude membrane preparations were obtained from thecal layers, granulosa cells, and whole ovaries of coho salmon in the postvitellogenic/preovulatory phase. Binding of 125I-GTH I to membranes from thecal layers, granulosa cells, and whole ovaries, and binding of 125I-GTH II to thecal layer cell membranes could be inhibited by both GTHs, but GTH I was more potent than GTH II. In contrast, GTH II was more potent than GTH I in inhibiting 125I-GTH II binding to membranes from granulosa cells and whole ovaries, but the inhibition curves were not parallel. Scatchard plot analysis suggested that there was a single type of receptor in the thecal layers for both GTHs, whereas in the granulosa cells there was more than one type of receptor for both GTHs. Based on these results, a two-receptor model for the postvitellogenic/preovulatory salmon ovary is proposed with the following features: 1) there are two types of gonadotropin receptors in the salmon ovary, type I and type II; 2) the type I receptor binds both GTHs, but with higher affinity for GTH I, whereas the type II receptor is highly specific for GTH II and may have only limited interaction with GTH I; and 3) the type I receptor is present in both thecal cells and granulosa cells, whereas the type II receptor is present in granulosa cells.
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758
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Kerr CP, Yan L. Pulmonary embolism. Clinical decision making to increase diagnostic accuracy. Postgrad Med 1992; 91:73-6, 79-80, 83-6. [PMID: 1589370 DOI: 10.1080/00325481.1992.11701345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
In this article, Drs Kerr and Yan describe four cases--two handled the wrong way and two the right way--to help you frame a set of criteria that will work for you in suspecting, testing for, diagnosing, and treating pulmonary embolism in ambulatory patients. In addition, Dr Kerr uses his legal expertise to provide suggestions on avoiding liability resulting from inadequate documentation.
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759
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Hong C, Qian L, Xie W, Yan L. [Relationship between serum level of zinc and copper and inhibitory effect of herba Asari oil on proliferation of granuloma induced by implantation of cotton pellets in rats]. ZHONGGUO ZHONG YAO ZA ZHI = ZHONGGUO ZHONGYAO ZAZHI = CHINA JOURNAL OF CHINESE MATERIA MEDICA 1992; 17:236-8, inside backcover. [PMID: 1418554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Intraperitoneal injection of the essential oil of Asarum himalaicum and A. heterotropoides var. mandshuricum may inhibit the proliferation of granuloma induced by implantation of cotton pellets in rats. This action might be related to the reduction of blood serum zinc.
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760
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Yan L, Yee JA, Boylan LM, Spallholz JE. Effect of selenium compounds and thiols on human mammary tumor cells. Biol Trace Elem Res 1991; 30:145-62. [PMID: 1723886 DOI: 10.1007/bf02990350] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effect on cell viability and growth rate of sodium selenite, selenocystine, sodium selenate, and selenomethionine at selenium concentrations of 6.25 and 12.5 uM was studied in vitro on cells of the human mammary tumor cell line HTB123/DU4475. Selenite and selenocystine affected both cell viability and growth rate of the tumor cells at these selenium concentrations. Selenite and selenocystine decreased intracellular glutathione concentrations, but did not affect tumor cell glutathione peroxidase activity. After six days of exposure to either selenate or selenomethionine, the viability of tumor cells remained stable, but cell growth, as measured by numbers of cells, was retarded. Neither selenate nor selenomethionine produced changes in concentrations of intracellular glutathione. The toxic effect of selenite on tumor cells was enhanced by addition of 0.25 mM glutathione to the growth medium. Preincubation of the tumor cells with 62.5 uM buthionine sulfoximine decreased cellular glutathione to 15% of controls at 24 h and enhanced the toxicity of selenite toward the tumor cells. Glutathione, 2-mercaptoethanol, and L-cysteine were all toxic to the tumor cells in a dose-dependent manner.
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761
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Yan L. [An investigation of fluoride pollution caused by burning coal containing fluoride in Xiushan and Baojing]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1991; 12:102-5. [PMID: 2065338] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
This paper reports an investigation of contents of soluble fluoride in the environment and foods in Xiushan and Baojing. On the basis of measuring concentrations of soluble fluoride in drinking water, soil, coal, air, fly ash, maize, chilli, and other kinds of vegetables, it is first to expand the pathway of fluoride migrating from coal into human body is through pollution of air by fluoride contained in fly ash on burning of coal, and then via consumption of polluted maize by air. The significant correlation between both the concentrations of fluoride in maize and in fly ash is proved. It is suggested to select the concentration of fluoride in fly ash or in air as the quality index of indoor air and the control target to prevent fluorosis.
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762
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Yan L, Boylan LM, Spallholz JE. Effect of dietary selenium and magnesium on human mammary tumor growth in athymic nude mice. Nutr Cancer 1991; 16:239-48. [PMID: 1775386 DOI: 10.1080/01635589109514162] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The effect of dietary selenium (Se) supplementation and low dietary magnesium (Mg) on growth of cells of the human mammary tumor cell line (HTB123/DU4475) and the tissue glutathione (GSH) content in female athymic nude mice was studied. Sixty three- to four-week-old female athymic nude mice were randomly divided into six dietary groups of 10 animals. The mice were fed a modified AIN-76A diet with two levels of Mg (100 and 665 mg/kg) and three levels of Se (0.04, 0.2, and 4.0 mg/kg). At the fourth week of dietary treatment, mice were subcutaneously inoculated with 2.5 x 10(6) viable tumor cells on the dorsal lumbar region and then fed their respective diets for another four weeks. Dietary Se supplementation had no significant effect on tumor growth or tissue GSH content. Low dietary Mg limited both tumor growth and tissue GSH synthesis but raised Mg and GSH levels in tumor tissues. The growth of mice fed the diet containing 100 mg/kg Mg and 4.0 mg/kg Se was significantly retarded. This study demonstrated that neither Se deficiency nor Se supplementation had any effect on mammary tumor growth or tissue GSH content in athymic nude mice. Low dietary Mg did retard tumor growth and inhibited GSH synthesis. Low dietary Mg also resulted in an apparent increase in Se toxicity in these animals.
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763
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Yan L. [Epidemiological survey of endemic fluorosis in Xiou Shan and Bao Jing areas]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 1990; 11:302-6. [PMID: 2261621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
It may be affirmed that Mushan in Bao Jing county is a light fluorosis area and Yan Tian in Xiou Shan county is a middle fluorosis area with the help of following investigations: fluoride levels in inhalatable dust, food, drinking water, soil, coal, biological effects of fluoride on habitants and the burden of fluoride in the body of habitants. It is demonstrated that the cause of fluorosis is above areas is essentially the oral intake of excess fluoride through the foods, mainly maize, polluted by burning coal fly ash containing fluoride.
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764
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Yan L, Wei J, Wu H, Chen H, Zhong G, Li L, Chen L, Li K, Tan J. [The role of hemorheologic changes in the pathogenesis of acute hemorrhagic necrotizing pancreatitis]. HUA XI YI KE DA XUE XUE BAO = JOURNAL OF WEST CHINA UNIVERSITY OF MEDICAL SCIENCES = HUAXI YIKE DAXUE XUEBAO 1990; 21:25-9. [PMID: 1694813] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The hemorheologic alterations were studied in experimental acute hemorrhagic necrotizing pancreatitis (AHNP) which was induced by injection of 5% sodium taurocholate into the main pancreatic duct. The results showed that during the early stage of AHNP, all of hemorheologic parameters were significantly elevated, and continually increased at the rest intervals. The authors suggested that the blood viscosity and hematocrit increase, red blood cells tend to aggregate, and erythrocyte deformation decrease are the causation of pancreatic microcirculatory disturbances and promoting pancreatic progressive necrosis. After using low molecular dextran and Salvia miltiorrhizae, the hemorheologic alterations in AHNP were recovered, and the histologic observation improved. Our data indicate the hemorheologic disturbances is one of the key factors in the pathogenesis of AHNP.
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765
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Dickhoff WW, Yan L, Plisetskaya EM, Sullivan CV, Swanson P, Hara A, Bernard MG. Relationship between metabolic and reproductive hormones in salmonid fish. FISH PHYSIOLOGY AND BIOCHEMISTRY 1989; 7:147-155. [PMID: 24221766 DOI: 10.1007/bf00004701] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Circulating concentrations of estradiol (E2), vitellogenin (VTG), thyroxine (T4), triiodothyronine (T3) and insulin were measured in reproductively maturing four and five year-old Atlantic salmon. Blood samples were collected from the fish in seawater for one year prior to their spawning in November in fresh water. In females, E2 and VTG were low but detectable from December to July, and then increased to peak levels in September and October. Plasma levels of T4 and T3 were relatively constant in winter and spring, and decreased in July. Plasma concentration of T4 increased in November when the fish returned to fresh water. Plasma T3 levels remained low during the autumn. Both T4 and T3 levels tended to be higher in males than in females during September through November. Plasma insulin concentrations increased during the spring to peak values in May, and then decreased in June and July in fish of both sexes. There was a significant elevation of plasma insulin in males during October, and the levels in males tended to be higher than those found in females during final maturation.
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766
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Yan L, Xi Z, Drettner B. Epidemiological studies of nasopharyngeal cancer in the Guangzhou area, China. Preliminary report. Acta Otolaryngol 1989; 107:424-7. [PMID: 2547276 DOI: 10.3109/00016488909127534] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In the city of Guangzhou (Canton) and its surroundings nasopharyngeal cancer (NPC) constitutes about 32% of all cancer and is therefore the most common kind of cancer. Three types of etiological factors seem to be involved: 1) a hereditary factor, 2) Epstein-Barr virus, and 3) external factors in food and water. An epidemiological study has been started in the Guangzhou area with interviews of NPC cases, matching controls and mothers of the cases and controls concerning especially food and environmental factors and infections in childhood. The questions put to the controls and cases covered the last seven years and the age of ten, while those to the mothers covered the first three years of life and the age of ten for the controls and cases. Results are now available for 140 cases, 140 controls and the corresponding living mothers. They indicate that salted fish, particularly of Cantonese style, was consumed more by NPC cases than by controls and also had more frequently been given to weaning children in whom NPC later developed. Furthermore, salted vegetables and salted pork were consumed to a greater extent by NPC cases than by controls. Drinking of polluted water in childhood was more common among the NPC cases. Consumption of fresh fruit was more rare among the cases. Most of the NPC cases had a positive VCA-IgA titre.
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767
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Yan L, Shen Y. [Nursing care in extracorporeal shock wave lithotripsy]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1989; 24:264-5. [PMID: 2791137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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768
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Palozza P, Piccioni E, Yan L, Bartoli GM. Membrane modifications induced by superoxide dismutase depletion as a model of oxidative stress. Ann N Y Acad Sci 1988; 551:131-2. [PMID: 3245657 DOI: 10.1111/j.1749-6632.1988.tb22328.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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769
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Baichwal RR, Yan L, Bosler A, DeVries GH. An automated method for autoradiographic analysis of cultured Schwann cells. J Neurosci Methods 1987; 20:295-305. [PMID: 3626620 DOI: 10.1016/0165-0270(87)90062-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
A semi-automated analysis system based on video image analysis was developed to count labelled and unlabelled nuclei of Schwann cells which had been exposed to tritiated thymidine followed by processing for autoradiography. A Model 3000 Image Analysis system (Image Technology Corporation, Deer Park, NY) was used to acquire and process the images and provide quantitative measurements based on the distinctive size and shape of the Schwann cell nucleus. The maximum and minimum dimensions for the labelled and unlabelled nuclei were determined. These stored dimensional parameters were then compared with the dimensions of a given field of cell nuclei by the image analysis system. The counts from various fields were collected until a total of 1000 labelled and unlabelled nuclei had been analyzed. A labelling index (LI = ratio of labelled cells to total cells X 100) was then calculated and printed by the system. LIs of autoradiographs determined by automated analysis correlated well with those determined by visual cell counting. The principle of the image analysis program as described here is applicable to other systems for the measurement of LIs of a particular cell type in a mixed population. This automated process eliminates both the subjectivity and fatigue of visual counting and facilitates the rapid measurement of the LI of large numbers of autoradiographs with precision.
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770
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Chai WG, Yan L, Wang GH, Liang XY, Zhao YF, Ji GJ. Improvement in sensitivity of fast atom bombardment mass spectrometry of amino acids by di-isopropylphosphorylation. BIOMEDICAL & ENVIRONMENTAL MASS SPECTROMETRY 1987; 14:331-3. [PMID: 2959340 DOI: 10.1002/bms.1200140706] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Positive ion fast atom bombardment mass spectrometric sensitivities of seven amino acids and the corresponding di-isopropylphosphorylated derivatives were carefully compared. Results showed that an improvement in sensitivity by factors of 4-29, mostly above 10, were achieved after the derivatization. The chemical noise derived from glycerol matrix was also greatly reduced by this derivatization.
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771
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Yan L, Ling JD, Ho PT, Lee CH. Picosecond-pulse generation from a continuous-wave neodymium:phosphate glass laser. OPTICS LETTERS 1986; 11:502-503. [PMID: 19738669 DOI: 10.1364/ol.11.000502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Seven-picosecond pulses at 1054 nm have been generated from a continuous-wave neodymium:phosphate glass laser by active mode locking.
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772
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Yan L, Langlois B, O’Leary J, Hicks C. Purification and Characterization of Four Extracellular Proteases Isolated from Raw Milk Psychrotrophs. J Dairy Sci 1985. [DOI: 10.3168/jds.s0022-0302(85)80968-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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