676
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Abstract
The guanidine hydrochloride (GuHCl)-induced denaturation of the gene V protein of bacteriophage f1 has been studied, using the chemical reactivity of a cysteine residue that is buried in the folded protein and the circular dichroism (CD) at 211 and 229 nm as measures of the fraction of polypeptide chains in the folded form. It is found that this dimeric protein unfolds in a single cooperative transition from a folded dimer to two unfolded monomers. A folded, monomeric form of the gene V protein was not detected at equilibrium. The kinetics of unfolding of the gene V protein in 3 M GuHCl and the refolding in 2 M GuHCl are also consistent with a transition between a folded dimer and two unfolded monomers. The GuHCl concentration dependence of the rates of folding and unfolding suggests that the transition state for folding is near the folded conformation.
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677
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Ji XW, Tan J, Chen XY, Yi SX, Liang H. New type of X-linked progressive muscular dystrophy involving shoulder girdle and back. AMERICAN JOURNAL OF MEDICAL GENETICS 1990; 37:209-12. [PMID: 2248287 DOI: 10.1002/ajmg.1320370209] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
A new type of X-linked muscular dystrophy is described in a family in which 7 men had boyhood onset of progressive dystrophy involving muscles of the shoulder and back but not the calves or face. The scapula-back muscles are affected, but the calf muscles are normal. All patients are still able to walk. The oldest patient is now 37 years old. The muscular dystrophy has been specified by electromyography, pathologic tissue microscopic examination, electron microscopic study, and elevated CK. This type of muscular dystrophy has not been reported previously.
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678
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Wu X, Zhuang Y, Huang R, Liang H. [Rapid identification of Mycobacterium tuberculosis and other mycobacteria with Mycobacterium tuberculosis whole chromosomal DNA probe]. WEI SHENG WU XUE BAO = ACTA MICROBIOLOGICA SINICA 1990; 30:234-7. [PMID: 2123584] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The dot-blots containing DNA isolated from nonmycobacterial and mycobacterial microorganisms were hybridized with 32P-labeled M. tuberculosis whole chromosomal DNA at the various temperatures. The probe did not cross-hybridize to DNA of nonmycobacterial microorganisms (E. coli, Plasmid pUC19, Nocardia asteriodes), nor with DNA from all mycobacteria tested except M. bovis BCG under the higher temperature conditions. Microorganisms could also be directly spotted and lysed on nitrocellulose filters and used for hybridization thus making this technique suitable for clinical diagnosis.
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679
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Kubiniec RT, Liang H, Hui SW. Effects of pulse length and pulse strength on transfection by electroporation. Biotechniques 1990; 8:16-20. [PMID: 2182073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The relative importance of pulse field strength E and pulse length tau 1/2 (half decay time of an exponential decay pulse) on the stable transfection frequency for HeLa or HUT-78 cells was investigated. Cells were transfected with plasmids containing the promoter and drug resistant genes pRSVgpt or pRSVneo by electroporation. The stable transfection frequency was assayed using the marker rescue technique. The transfection frequency increases with increasing values of E tau 1/2. For a given pulse length, the transfection frequency is proportional to the power of the pulse (E2 tau 1/2). Pulses with half decay times of 2.2 to 4.6 ms appear to be more efficient than 0.275 to 0.31 ms for stable transfection of HeLa cells.
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680
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Feavers IM, McEwan IJ, Liang H, Jost JP. An estradiol-dependent protein from chicken liver binds single-stranded DNA and RNA. J Biol Chem 1989; 264:9114-7. [PMID: 2470751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
We have identified two estradiol-dependent single-stranded DNA binding proteins in the nucleus and cytoplasm of chicken hepatocytes that bind the sequence 5'TCACCTTCGCTATG3' in the first exon of the chicken vitellogenin gene. As judged by chromatography on heparin-Sepharose and by proteolytic clipping bandshift assay, the two proteins are different. Furthermore, they only bind to the oligonucleotide corresponding to the upper strand. Depurination and depyrimidination interference experiments with the cytoplasmic protein show that the bases CCTT-G are involved in the protein-DNA interaction. An RNA corresponding to the upper strand of the gene between nucleotide positions -73 and +53 competes for binding to the single-stranded DNA. UV cross-linking experiments performed with bromouridine-substituted single-stranded RNA reveal that an estradiol-dependent hepatocyte cytoplasmic protein with a Mr of 71,000 binds to the mRNA-like single-stranded RNA.
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681
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Chen SL, Zang YM, Zhu MZ, Luo BG, Liu DM, Liang H. [The relationship between coronary artery stenosis and myocardial metabolism of oxygen demand in dogs]. SHENG LI XUE BAO : [ACTA PHYSIOLOGICA SINICA] 1989; 41:272-7. [PMID: 2781311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
In open chest dogs, a micrometer constrictor was used to produce three different coronary artery stenosis (AS) on left circumflex coronary artery, and hemodynamics, blood gas and coronary sinus pH, lactate were then measured. In mild coronary AS, resting coronary artery flow (CBF) did not decrease; but lactate increased. In critical coronary AS, CBF slightly decreased, MVO2 decreased and lactate increased. There was a decrease in CBF, O2 supply/consumption ratio, coronary sinus pH and an increase in oxygen extraction and lactate with severe coronary AS. The percent area stenosis (%AS) was highly correlated with O2 supply (r = -0.92), poorly correlated with MVO2 (r = -0.58) when it was higher than 75%.
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682
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Hu YH, Liang H, Jiang YQ. Study on mechanism of micronucleoli formation by laser microirradiation. CELL BIOPHYSICS 1989; 14:257-69. [PMID: 2472212 DOI: 10.1007/bf02797272] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In the male rat kangaroo cell line PTK2, argon laser (514.5 nm) microirradiation of both nucleoli in interphase cells 30, 23, and 12 h before mitosis, and nucleoli in early prophase cells resulted in the formation of micronucleoli, i.e., several small nucleolus-like bodies, in daughter cells. The irradiated cells were stained with methylene blue, which indicated that the nucleolar RNA was destroyed by laser microirradiation. Feulgen staining was applied to the irradiated cells in combination with the measurements of an MPV-II model microphotometer. Irradiated nucleoli were negative for DNA-Feulgen stain, which indicated that nucleolar DNA was destroyed by laser irradiation, so the nucleolar organizer gene was destroyed. After the nucleoli had been irradiated, the cells were continuously incubated at 37 degrees C for 12 and/or 24 h, then fixed and stained with AgNO3. Most of the nucleoli irradiated silver-stained negative that demonstrated that when the nucleoli were irradiated, rDNA was destroyed and transcription stopped. However, some silver grains were found in the nucleoplasm, whereas the nucleoli were silver-stained negative. The results suggest that subsidiary nucleolar organizer loci might exist scattered throughout the genome.
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683
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Feavers IM, McEwan IJ, Liang H, Jost JP. An Estradiol-dependent Protein from Chicken Liver Binds Single-stranded DNA and RNA. J Biol Chem 1989. [DOI: 10.1016/s0021-9258(18)60498-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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684
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Ji XW, Chen XY, Tan J, Liang H. Balanced X;15 translocation 46,X,t(X;15)(q21;q23) associated with primary amenorrhea. AMERICAN JOURNAL OF MEDICAL GENETICS 1988; 31:783-6. [PMID: 3239568 DOI: 10.1002/ajmg.1320310409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Cytogenetic studies on a woman with primary amenorrhea showed an X;15 translocation, karyotype 46,X,t(X;15)(q21;q23). Fifteen percent of the buccal cells showed a normal-sized sex chromatin body. The normal X chromosome was uniformly inactivated. Many balanced X;15 translocations have been reported; however, breakpoints in our patient differ from those reported previously. This case also supports earlier evidence that ovarian development fails when the breakpoint of the X chromosome is in the region X q13-q25 or q13-q27.
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685
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Stenger DA, Kubiniec RT, Purucker WJ, Liang H, Hui SW. Optimization of electrofusion parameters for efficient production of murine hybridomas. Hybridoma (Larchmt) 1988; 7:505-18. [PMID: 3198135 DOI: 10.1089/hyb.1988.7.505] [Citation(s) in RCA: 28] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Several factors which affect the production of murine hybridomas by electrofusion using SP2/0 myelomas were examined. These factors included the ionic composition, specific resistance and osmotic strength of the fusion medium, proteolytic pretreatment of the cells, and field strength of the single, rectangular, 15 or 20 microseconds electric pulse. Individual experiments were observed by phase microscopy, video-recorded, and subsequently analyzed. The efficiency of hybridoma formation was measured by the number of hybrid colonies which survived HAT medium selection. In most cases, the peak efficiency occurred when the pulse field was between 3 and 4 kV/cm. Ca++ and Mg++, in 0.1 and 0.5 mM concentrations, respectively, helped to prevent large-scale SP2/0 lysis following pulse application. Reduction of the osmolarity of the fusion medium allowed for an approximate two-fold increase in the hybrid production efficiency. However, other variations, including an increase of the specific resistance of the medium to 1.7 x 10(4) omega cm, and a reduction of the pulse width to 15 microseconds, allowed significantly higher efficiencies. Dispase pretreatment of the myelomas led to additional improvements when using a 15 microseconds pulse. The data suggest that for this system, the highest efficiencies are obtained by maximizing the attractive polarization forces between cells, while adjusting the ionic composition and pulse parameters to preserve myeloma viability.
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686
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Liang H, Purucker WJ, Stenger DA, Kubiniec RT, Hui SW. Uptake of fluorescence-labeled dextrans by 10T 1/2 fibroblasts following permeation by rectangular and exponential-decay electric field pulses. Biotechniques 1988; 6:550-2, 554, 556-8. [PMID: 2483506] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
The uptake of fluorescence-labeled dextrans by adherent 10T 1/2 murine fibroblasts following electric field pulse application was used as a criterion for the efficiency of electropermeation. The cells in monolayers were permeated by immersing a coaxial electrode in culture dishes. The percentage of cells which exhibited fluorescence uptake following electric field pulse application was measured at independently varying pulse field strength and pulse length. Dextrans with molecular weights equal to or higher than 41,000 dalton require higher field strength or longer pulse time to penetrate the cells. There is no detectable advantage of using a rectangular pulse against using an exponential decay pulse of similar power. The uptake was proportional to the product of the pulse amplitude and duration over the experimental range of 40-950 microseconds and 0.1-14.5 kV/cm. Cell survival decreases at the upper end of this range. The result provides a direct comparison of electric parameters which so far have not been standardized with regard to cell electropermeation.
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687
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Lan HJ, Ye SD, Cai JJ, Yang CY, Sun ZQ, Liang H. Re-replacement of mitral valve--a report of 10 cases. JOURNAL OF TONGJI MEDICAL UNIVERSITY = TONG JI YI KE DA XUE XUE BAO 1987; 7:157-60. [PMID: 3448241 DOI: 10.1007/bf02888210] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
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688
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Liang H. [Superiority of primary nursing--experiences in nursing care of 120 patients with coma combined with paraplegia]. ZHONGHUA HU LI ZA ZHI = CHINESE JOURNAL OF NURSING 1987; 22:52-3. [PMID: 3646930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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689
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Liang H. [Cytotoxic effect of hematoporphyrin derivative (HPD) plus light irradiation in vitro]. ZHONGHUA ZHONG LIU ZA ZHI [CHINESE JOURNAL OF ONCOLOGY] 1986; 8:29-31. [PMID: 2942380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Cytotoxic effect of HPD plus light irradiation on PTK2 and HeLa cells in vitro were studied by laser microbeam irradiation. The dynamic changes, in three different steps as observed in the cells ranged from visible damage to cell lysis, were recorded at the monocellular level. It was found that the speed of the cytotoxic process varied chiefly with the dose of light used. The cytotoxic progress of PTK2 and HeLa cells was compared and analyzed. In addition, the cytotoxic effects of three different laser wavelengths (6328A, 5145A and 4880A) plus HPD were compared. The most significant killing effect occurred at 6328A wavelength of red light.
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690
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Liang H, Zhang CR. [Sphygmographic analysis in cerebral thrombosis]. ZHONGGUO YI XUE KE XUE YUAN XUE BAO. ACTA ACADEMIAE MEDICINAE SINICAE 1984; 6:131-3. [PMID: 6242361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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691
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Liang H, Berns MW. Establishment of nucleolar deficient sublines of PtK2 (Potorous tridactylis) by ultraviolet laser microirradiation. Exp Cell Res 1983; 144:234-40. [PMID: 6840209 DOI: 10.1016/0014-4827(83)90461-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
One of the two nucleoli of tetraploid PtK2 WA cells in early prophase was irradiated with an ultraviolet (UV) laser microbeam. The daughter cells that maintained the nucleolar deficiency were isolated and cloned. Five nucleolar deficient sublines of PtK2 WA were established, thus providing an experimental system to study the ribosomal gene-nucleolar organizer complex.
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692
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Liang H, Berns MW. Induced genetic deficiency of the nucleolar organizer in rat kangaroo cells (PTK1) by ultraviolet laser microirradiation. CELL BIOPHYSICS 1983; 5:21-31. [PMID: 6190564 DOI: 10.1007/bf02788584] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
An ultraviolet laser microbeam was used to irradiate one of the two nucleolar organizer regions of PTK1 cells in early prophase. The directed nucleolar deficiency induced by ultraviolet laser irradiation was maintained in the daughter cells through subsequent cell generations. However, the frequent occurrence of spontaneous cell fusion in low density cells following the cloning procedure facilitated a recovery of cells to two or more nucleoli.
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693
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Shixin L, Mingxin L, Chuan J, Mingyao W, Yinglin W, Liang H. A new N-nitroso compound, N-3-methylbutyl-N-1-methylacetonylnitrosamine, in corn-bread inoculated with fungi. SCIENTIA SINICA 1979; 22:601-7. [PMID: 112677] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A new N--nitroso compound, N--1--methylacetonyl--N--3--methylbutylnitrosamine (MAMBNA) is found in corn-bread inoculated with the common fungi, such as Fusarium moniliforme, Geotrichun candidum, Aspergillus terreus or A. flavipes, encountered in food of Lin Xian County, Henan Province. The preliminary identification of this compound with TLC has been confirmed by GC-MS analysis. Furthermore, we have synthesized the MAMBNA and the chemical analysis shows that it is identical with the MAMBNA isolated from the corn-bread extract. In addition to the MAMBNA, dimethylnitrosamine, diethylnitrosamine and methylbenzylnitrosamine are formed also in the fungus-inoculated corn-bread after 8-day incubation and an addition of a small amount of sodium nitrite. The presence of precursor compounds for the formation of nitrosamine in the mouldy maize flour and their significance in respect to the etiology of esophageal cancer in high-risk areas have been discussed.
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694
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Verbin RS, Diluiso G, Liang H, Farber E. Synchronization of cell division in vivo through the combined use of cytosine arabinoside and Colcemid. Cancer Res 1972; 32:1489-95. [PMID: 5030577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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695
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Verbin RS, Diluiso G, Liang H, Farber E. The effects of cytosine arabinoside upon proliferating epithelial cells. Cancer Res 1972; 32:1476-88. [PMID: 5030576] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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696
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Farber E, Liang H, Shinozuka H. Dissociation of effects on protein synthesis and ribosomes from membrane changes induced by carbon tetrachloride. THE AMERICAN JOURNAL OF PATHOLOGY 1971; 64:601-17. [PMID: 5133520 PMCID: PMC2047618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Pretreatment of rats with cycloheximide protects the liver against ribosome changes but not against alterations in the endoplasmic reticulum membrane induced by the administration of CCl(4), as observed both biochemically and ultrastructurally. Another inhibitor of protein synthesis, tenuazonic acid, has effects similar to cycloheximide. Neither compound has any apparent effect when given after the administration of CCl(4) at a time at which a major shift in ribosome distribution from polysomes to ribosome monomers or subunits has already occurred. Thus, it appears that the ribosomes are not susceptible to damage by CCl(4), or more probably an active metabolic derivative of CCl(4), when they are organized as polysomes but only when they are present as monomers or subunits. Also, unlike the situation with ethionine or puromycin, the damage to the protein synthetic system of the ribosomes induced in the liver by CCl(4) appears to be irreversible. In contrast to cycloheximide or tenuazonic acid, N,N'-diphenyl-p-phenylenediamine (DPPD) protects the liver against CCl(4)-induced changes in both ribosomes and endoplasmic reticulum. These observations suggest that the changes in the ribosome-protein synthetic system induced in the liver by treatment with CCl(4) are not the direct result of damage to the membranes of the endoplasmic reticulum but are either an indirect effect of such damage or are unrelated to it. These possibilities are discussed in terms of three proposed working hypotheses.
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697
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Verbin RS, Liang H, Saez LM, Diluiso G, Goldblatt PJ, Farber E. Effects of inhibitors of protein synthesis on structure and function of the crypts of the small intestine. Exp Cell Res 1971; 65:81-93. [PMID: 5549554 DOI: 10.1016/s0014-4827(71)80052-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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698
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Rajalakshmi S, Liang H, Sarma DS, Kisilevsky R, Farber E. Cycloheximide, an inhibitor of peptide chain termination or release in liver in vivo and in vitro. Biochem Biophys Res Commun 1971; 42:259-65. [PMID: 5545517 DOI: 10.1016/0006-291x(71)90096-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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699
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Lieberman MW, Sullivan RJ, Shull KH, Liang H, Farber E. Partial characterization and cellular localization of two deoxyribonucleases in the small intestine of the rat. CANADIAN JOURNAL OF BIOCHEMISTRY 1971; 49:38-43. [PMID: 4995052 DOI: 10.1139/o71-007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
We have partially characterized and localized two previously reported deoxyribonucleases from the rat small intestine. After separation of the crypt cells and muscle (the deep layer) from the villus cells (the superficial layer), the latter was found to contain a deoxyribonuclease I with a pH optimum around 6, and a molecular weight of 32 000 – 35 000. It was activated by Co2+, Mg2+, and Mn2+. Ligation of the pancreatic duct reduced the activity in intestinal extracts to about one-third of control levels. A deoxyribonuclease II with a pH optimum of 5.3–5.4 was found associated with the continuously dividing intestinal crypt cells. It was inhibited by Mg2+ and activated by EDTA. Ligation of the pancreatic duct was without effect on this enzyme. The deoxyribonuclease I is probably largely extracellular and serves a digestive function while the deoxyribonuclease II probably is related to intracellular DNA metabolism.
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700
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Verbin RS, Longnecker DS, Liang H, Farber E. Some observations on the acute histopathologic effects of cycloheximide in vivo. THE AMERICAN JOURNAL OF PATHOLOGY 1971; 62:111-25. [PMID: 5538717 PMCID: PMC2047404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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