5551
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Chen X, Finch LR. Novel arrangement of rRNA genes in Mycoplasma gallisepticum: separation of the 16S gene of one set from the 23S and 5S genes. J Bacteriol 1989; 171:2876-8. [PMID: 2708324 PMCID: PMC209978 DOI: 10.1128/jb.171.5.2876-2878.1989] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Large restriction fragments from the DNA of Mycoplasma gallisepticum S6 and PG31, which were prepared by digestion with BglI, BssHII, SmaI, or XhoI and which were separated by pulsed-field electrophoresis, were hybridized with probes containing most, or different parts, of an rRNA operon of Mycoplasma capricolum. The results showed that the genomes contained three widely separated rRNA loci. One locus contained genes for all three rRNA species and another contained 23S and probably 5S rRNA genes, whereas the third appeared to have only a 16S rRNA gene.
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MESH Headings
- Blotting, Southern
- DNA, Bacterial/genetics
- DNA, Ribosomal/genetics
- Mycoplasma/genetics
- RNA, Ribosomal/genetics
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 23S/genetics
- RNA, Ribosomal, 5S/genetics
- Restriction Mapping
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5552
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Li YS, Chen X, Sun RL. [Pacemaker syndrome: a report of 6 cases]. ZHONGHUA NEI KE ZA ZHI 1989; 28:163-6, 187. [PMID: 2805951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Six patients suspected to have "pacemaker syndrome" were studied with hemodynamic and electrophysiologic methods. Symptoms appeared after implantation of ventricular pacemaker (VVI). Mile symptoms such as dizziness and fatigue and severe symptom of heart failure were noted. The results of the study suggested that cardiac output decreases due to loss of atrial contribution to ventricular filling and also as a result of increase of systemic venous pressure. If the patient has V-A conduction, cardiac output will decrease further. Restoration of atrioventricular synchronization is essential in the treatment of the pacemaker syndrome.
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5553
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Guo CY, Sun RL, Chen X. [Electrophysiologic study of concealed accessory A-V pathway]. ZHONGHUA NEI KE ZA ZHI 1989; 28:85-8, 126. [PMID: 2737040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The presence of concealed accessory A-V pathways (CAP) was demonstrated in 14 out of 18 (78%) patients with supraventricular tachycardia (SVT) and narrow QRS complexes. Such a high percentage of CAP mediated AVRT is a quite unique finding. The importance of a standard programmed electrical stimulation protocol in documenting CAP is emphasized. Careful atrial mapping and premature ventricular stimulation during SVT are very helpful for diagnosis and localization of CAP. We considered that a V-A interval of 75 ms or more on intracardiac electrogram or a R-P interval of 85 ms or more on esophageal electrogram is a good criterion for AVRT utilizing an accessory pathway.
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5554
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Pu JL, Chen X, Sun RL. [Acute electrophysiologic effects of intravenous ethmozin in patients with paroxysmal supraventricular tachycardia due to WPW syndrome]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 1988; 16:329-31, 381-2. [PMID: 3073934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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5555
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Chen X, Henderson K, Beinfeld MC, Westfall TC. Alterations in blood pressure of normotensive and hypertensive rats following intrathecal injections of neuropeptide Y. J Cardiovasc Pharmacol 1988; 12:473-8. [PMID: 2465449 DOI: 10.1097/00005344-198810000-00014] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effect of the intrathecal administration of neuropeptide Y (NPY) on blood pressure and heart rate of anesthetized normotensive and hypertensive rats was studied. Neuropeptide Y was observed to produce a decrease in the blood pressure of Sprague-Dawley, Wistar Kyoto (WKY), DOCA-salt, and DOCA-sham control rats. The maximum percent decrease in blood pressure of Sprague-Dawley rats was 12.8 and 15.2% in response to 0.1 and 1.0 nmol NPY, respectively. Similar changes in heart rate were observed. The depressor effect of intrathecal NPY was attenuated by prior treatment with yohimbine and propranolol but not prazosin. The depressor effect of intrathecal NPY observed in normotensive and DOCA-salt hypertensive rats was not seen in the spontaneously hypertensive rat (SHR). The studies extend to the spinal cord the list of regions and tissues where NPY can produce physiological effects. It is concluded that the effects of NPY are closely associated with sympathetic preganglionic neurons in the spinal cord that the depressor effect of NPY involves alpha 2 and beta adrenoceptors, and that a loss of the depressor effect of NPY may contribute to the development or maintenance of hypertension in the SHR.
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5556
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Sun RL, Guo CY, Hu SJ, Yu PZ, Tian RG, Chen X. Clinical application of antitachycardia pacemaker. A report of 6 cases. Chin Med J (Engl) 1988; 101:731-6. [PMID: 3150705] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
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5557
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Chen X, Fang YX, Xiong WS, Su Z, Hu KL, Wu WJ, Liu ZQ. Comparative effects of captopril, nitroprusside, dopamine and lanatoside C on a new model of rabbit congestive heart failure. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1988; 9:402-8. [PMID: 3064549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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5558
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Prout G, Lin CW, Benson R, Nseyo U, Daly J, Griffin P, Kinsey J, Tian ME, Lao YH, Main YZ, Chen X, Ren FM, Qiao SJ. Photodynamic Therapy With Hematoporphyrin Derivative in the Treatment of Superficial Transitional-Cell Carcinoma of the Bladder. J Urol 1988. [DOI: 10.1016/s0022-5347(17)42809-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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5559
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Xin ZY, Brettell RIS, Cheng ZM, Waterhouse PM, Appels R, Banks PM, Zhou GH, Chen X, Larkin PJ. Characterization of a potential source of barley yellow dwarf virus resistance for wheat. Genome 1988. [DOI: 10.1139/g88-043] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Resistance to barley yellow dwarf virus (BYDV) has been described in lines derived from crosses between wheat and Thinopyrum intermedium. The resistance in one such line, Zhong 4, originating in China, was expressed against two different serotypes of BYDV as measured by accumulation of virus in infected seedlings. F1 hybrids between wheat (2n = 42) and Zhong 4 (2n = 56) had 49 chromosomes and intermediate levels of virus when compared to the parent lines. Cytological and molecular hybridization studies suggested that the BYDV resistance in Zhong 4 is carried on a set of seven pairs of nonwheat chromosomes that derived from a combination of the E and X genomes present in Th. intermedium.Key words: Barley yellow dwarf virus, wheat, ribosomal DNA, Agropyron intermedium, Thinopyrum intermedium, virus resistance.
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5560
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Chen X, Kozubowski J, Gerberich W. Hydrogen-induced sustained load cracking in single crystal Fe-3wt.%Si. ACTA ACUST UNITED AC 1988. [DOI: 10.1016/s0036-9748(88)80342-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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5561
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Simons K, Watson W, Simons F, Chen X. 167 The pharmacokinetics and pharmacodynamics of hydroxyzine in the elderly. J Allergy Clin Immunol 1988. [DOI: 10.1016/0091-6749(88)90403-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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5562
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5563
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Westfall TC, Carpentier S, Chen X, Beinfeld MC, Naes L, Meldrum MJ. Prejunctional and postjunctional effects of neuropeptide Y at the noradrenergic neuroeffector junction of the perfused mesenteric arterial bed of the rat. J Cardiovasc Pharmacol 1987; 10:716-22. [PMID: 2450243 DOI: 10.1097/00005344-198712000-00016] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The effect of neuropeptide Y (NPY) on periarterial nerve stimulation-induced release of norepinephrine (NE) and increase in perfusion pressure in the perfused mesenteric arterial bed of the rat was examined. Perfusate effluents were continuously collected and assayed for endogenous NE by high-pressure liquid chromatography (HPLC) coupled to electrochemical detection. Perfusion pressure was continuously monitored by means of a pressure transducer. Periarterial nerve stimulation (8 or 16 Hz, 60 V, 2-ms duration for 30 s) resulted in a readily detectable increase in NE release and perfusion pressure that was attenuated by the prior administration of tetrodotoxin (TTX) (10(-5) M) or guanethidine (5 X 10(-5) M). NPY exerted both prejunctional and postjunctional effects on noradrenergic neurotransmission in this preparation. The peptide produced a concentration-dependent reduction in the release of NE over a concentration range of 10(-10) - 10(-7) M. A similar inhibition effect occurred at 8, 10, and 16 Hz. In contrast, low concentrations (10(-10) and 10(-9) M) decreased the effect of nerve stimulation on perfusion pressure, whereas higher concentrations (10(-7) M) produced a marked potentiation. The alpha 2-adrenoceptor antagonist, yohimbine, did not alter the inhibitory effect of NPY on evoked NE release or the effect on perfusion pressure. Prazosin similarly did not alter the inhibitory effect of NPY on NE release but prevented the increase in perfusion pressure. We conclude that NPY modulates noradrenergic neurotransmission in the mesenteric arterial bed by decreasing the evoked release of NE and producing a concentration-dependent biphasic response on vascular smooth muscle.(ABSTRACT TRUNCATED AT 250 WORDS)
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5564
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Pan CY, Chen X. Renormalization-group study of high-spin Heisenberg antiferromagnets. PHYSICAL REVIEW. B, CONDENSED MATTER 1987; 36:8600-8606. [PMID: 9942681 DOI: 10.1103/physrevb.36.8600] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/11/2023]
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5565
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Sun RL, Guo CY, Chen X. [Clinical use of antitachycardia pacemakers in 6 cases]. ZHONGHUA XIN XUE GUAN BING ZA ZHI 1987; 15:262-5, 310. [PMID: 3440428] [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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5566
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Chen X. Magic and myth of migration: a case study of a special economic zone in China. ASIA-PACIFIC POPULATION JOURNAL 1987; 2:57-76. [PMID: 12268937] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
The town of Shenzhen, China, experienced rapid economic and demographic growth following the government's creation of four Special Economic Zones in 1980. The role of migration in the Shenzhen phenomenon is examined as a practicum for policymakers and demographic specialists. Specifically, the paper is concerned with "the sources and mechanisms of migration, and characteristics of migrants to Shenzhen in order to clarify the relationship between rapid economic growth and its demographic consequences in China. It also briefly assesses the problems associated with migration to Shenzhen and how they may affect the city's future."
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5567
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Li K, Chen X. Protective effects of captopril and enalapril on myocardial ischemia and reperfusion damage of rat. J Mol Cell Cardiol 1987; 19:909-15. [PMID: 2828645 DOI: 10.1016/s0022-2828(87)80619-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The protective effect of angiotensin-converting enzyme inhibitors (ACEI) on myocardial ischemia and reperfusion damage was estimated in rat hearts, both in vivo and in vitro. Enalapril 2.5 mg/kg ip pretreatment at 24 and 5 h before coronary occlusion, significantly blunted the rise of CPK (445 +/- 151 vs 649 +/- 244 mu/ml, P less than 0.05) and improved electrocardiogram (ECG) 8 h after coronary occlusion. In global ischemia and reperfusion ex vivo, enalapril improved contractility (0.9 +/- 0.2 vs 0.3 +/- 0.3 g, P less than 0.05) and coronary flow (15.6 +/- 3.3 vs 11.9 +/- 3.1 ml/min/g, P less than 0.05), shortened significantly the duration of reperfusion arrhythmia (3.1 +/- 2.7 vs 9.7 +/- 8.1 min, P less than 0.05). In Langendorffs heart, captopril remarkably preserved force of contraction (2.1 +/- 0.4 vs 1.4 +/- 0.4 g, P less than 0.01) and coronary flow (2.7 +/- 0.5 vs 3.6 +/- 0.9 ml/min/g, P less than 0.05) in segmental infarction deteriorated by angiotensin I. Captopril 10(-5) M infusion reduced the release of CPK (435 +/- 112 vs 640 +/- 123 mu/min coronary flow, P less than 0.05). This action was almost completely abolished by pretreating and infusing with indomethacin. As a positive control, prostacyclin 5 X 10(-7) M infusion further reduced the release of CPK to 330 +/- 77 mu/min. It is concluded that angiotensin-converting enzyme inhibitor can protect both myocardial ischemia and reperfusion damage in rat hearts. The mechanism of protection was ascribed to reduced production of angiotensin II by ACE inhibition and increased prostacyclin release in the myocardium.
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5568
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Sun Y, Chen MH, Zhang YX, Xiao H, Liu HY, Chen X, Zeng Y. [Promoting effect of the Chinese medicinal herb, wikstroemia chamaedaphne and tung oil extracts on carcinoma of the uterine cervix induced by HSV-2 or methylcholanthrene (MCA) in mice]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1987; 9:345-7, 20. [PMID: 2838237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The promoting effect of the Chinese medicinal herb, Wikstroemia chamaedaphne and Tung oil extracts (WC and HHPA) on carcinoma of uterine cervix induced by HSV-2 or MCA in mice was studied. The results showed that WC and HHPA extracts were not carcinogenic themselves. After carcinogen HSV-2 and MCA treatment, WC and HHPA were added separately. The inducing rates by HSV-2 increased from 7.4% to 21.1% and 26.3%, those by MCA increased from 56.5% to 82.8% and 84.4%. There was a significant difference between the combined groups and groups with HSV-2 or MCA only. The experimental results suggest that these two kinds of extracts play a promoting effect on carcinogenesis. The relation between the carcinogenesis of uterine cervix or nasopharynx and WC or HHPA extracts is discussed.
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5569
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Chen X, Feng XW. Effects of anti-inflammatory Agent No.6 for injection on the oxidative burst of rat peritoneal macrophages. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1987; 7:65-9. [PMID: 3656488 DOI: 10.1007/bf02888163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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5570
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Fang YX, Chen X. [Effects of ginsenosides on myocardial lactic acid, cyclic nucleotides and ultrastructural myocardial changes in anoxia in mice]. ZHONG XI YI JIE HE ZA ZHI = CHINESE JOURNAL OF MODERN DEVELOPMENTS IN TRADITIONAL MEDICINE 1987; 7:354-6, 326. [PMID: 3690759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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5571
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Smatlak DL, Chen X, Lane BG, Hokin SA, Post RS. Experimental observation of the hot-electron equilibrium in a minimum-B mirror plasma. PHYSICAL REVIEW LETTERS 1987; 58:1853-1856. [PMID: 10034555 DOI: 10.1103/physrevlett.58.1853] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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5572
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Zhang FL, Chen X. Effects of ginsenosides on sympathetic neurotransmitter release in pithed rats. ZHONGGUO YAO LI XUE BAO = ACTA PHARMACOLOGICA SINICA 1987; 8:217-220. [PMID: 2889319] [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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5573
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Chen X, Schmidt B, Dunkelberg H. [The induction of sister chromatid exchange by diethylstilbestrol and mitomycin C in lymphocytes of mothers and their newborn infants]. ZENTRALBLATT FUR BAKTERIOLOGIE, MIKROBIOLOGIE UND HYGIENE. SERIE B, UMWELTHYGIENE, KRANKENHAUSHYGIENE, ARBEITSHYGIENE, PRAVENTIVE MEDIZIN 1987; 184:78-86. [PMID: 3113098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Lymphocytes of mothers and their newborn infants were treated with varying concentrations of diethylstilbestrol (10(-6) M, 10(-5) M and 10(-4) M) and mitomycin C (0.003, 0.009 and 0.03 microgram/ml), and the incidence of sister chromatid exchanges (SCE) was determined. The results showed that the spontaneous SCE rate in the newborns is less than that of their mothers. A dose-related increase in SCEs was observed in cells exposed to the alkylating chemical mitomycin C, while increases in SCEs were not noted in cultures exposed to diethylstilbestrol. No different susceptibilities of lymphocytes from mothers and newborns to the chemical induction were observed.
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5574
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Chen X. [New concepts and methods in the study of anti-myocardial ischemia drugs]. YAO XUE XUE BAO = ACTA PHARMACEUTICA SINICA 1987; 22:150-5. [PMID: 2887085] [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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5575
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Dekmezian R, Chen X, Kuo T, Ordóñez N, Katz RL. DNA hybridization for human papillomavirus (HPV) in cervical lesions. Relationship of the presence of various viral subtypes to expression of HPV structural proteins, involucrin, and carcinoembryonic antigen. Arch Pathol Lab Med 1987; 111:22-7. [PMID: 3026279] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
We studied cervical tissue from 20 patients with a variety of condylomatous, preneoplastic, and neoplastic lesions to detect various subtypes of human papillomavirus (HPV) at the molecular level by DNA hybridization. In addition, mirror image biopsy specimens were studied by an immunoperoxidase technique for the presence of HPV structural antigens, carcinoembryonic antigen (CEA), and involucrin, as markers of disturbed maturation and/or neoplasia. Of the 20 patients studied, we were able to demonstrate the presence of either HPV 16 or 18, or both, in three of seven squamous carcinomas tested, and three of five dysplasias. Interestingly, two cases of squamous carcinoma and one moderate dysplasia demonstrated HPV types 6 and 11 concurrently with HPV 16 and/or 18. Four of six condylomas showed HPV subtypes 6/11, and only one condyloma showed weak hybridization with HPV 18. Human papillomavirus structural antigen was seen in three of eight condylomas, and three of five dysplasias, but not in any carcinoma. All condylomas showed intense staining for involucrin in full-thickness of the epithelium, but the high-grade dysplasias and carcinomas showed only focal or absence of staining for involucrin. Carcinoembryonic antigen was expressed in 50% of the carcinomas with a pattern similar to that seen with involucrin, but did not correlate with any particular subtype of HPV. The molecular hybridization method seems to be superior for the detection of HPV lesions, and possibly for the prediction of their biologic behavior.
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