501
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502
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Akeson WH, Woo SL, Amiel D, Doty DH, Rutherford L. Value of 17beta-oestradiol in prevention of contracture formation. Ann Rheum Dis 1976; 35:429-36. [PMID: 1234409 PMCID: PMC1006575 DOI: 10.1136/ard.35.5.429] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Male and female rabbits were treated with 17beta-oestradiol during the 9-week development of a contracture in the left hind limb. The right hind limb served as the paired control. Untreated (absolute control) animals received saline injections. After 9 weeks biochemical analyses of water, hexosamine, soluble and total collagen, as well as biomechanical measurements of joint stiffness, were performed on the dissected knees. In all cases 17beta-oestradiol reduced the measured stiffness in the contractures by approximately 50% as compared to the contractures of the untreated animals. 17beta-oestradiol, in addition, partially prevented the loss of water and hexosamine which occurs in untreated contractures. 17beta-oestradiol administration also decreased the content of soluble collagen fractions in the periarticular connective tissue of both the control and experimental knees. The relationship of these biochemical findings to their mechanical consequences is discussed, and the results are related to a working hypothesis of stress- and motion-dependent homoeostasis within periarticular connective tissue.
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503
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Woo SL, Smith RG, Means AR, O'Malley BW. The ovalbumin gene. Partial purification of the coding strand. J Biol Chem 1976; 251:3868-74. [PMID: 932010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Purified ovalbumin messenger RNA was employed to selectively enrich the concentration of the gene coding for ovalbumin from total chick DNA by molecular hybridization. The coding strand of the ovalbumin gene was partially purified from sheared chick DNA by affinity column chromatography using ovalbumin mRNA immobilized on phosphocellulose. The concentrations of the ovalbumin DNA sequence in various DNA fractions were quantitated by measuring their rates of hybridization with 125I-labeled ovalbumin mRNA. When apparent Cot1/2 values of these reactions were compared to the apparent Cot1/2 value obtained from the hybridization reaction between 125I-ovalbumin mRNA and complementary DNA synthesized against ovalbumin mRNA using the enzyme reverse transcriptase, purification of the coding ovalbumin DNA strand over total chick DNA was estimated to be approximately 9,600-fold. There was no apparent degradation of the 4,000 nucleotide strands of chick DNA throughout the purification procedure. Since ovalbumin mRNA has a complexity of 1890 nucleotides, the resulting DNA was more than twice the length of ovalbumin mRNA and thus should contain DNA sequences adjacent to the structural portion of the ovalbumin gene.
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504
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Woo SL, Smith RG, Means AR, O'Malley BW. The ovalbumin gene. Partial purification of the coding strand. J Biol Chem 1976. [DOI: 10.1016/s0021-9258(17)33328-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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505
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Sperry PJ, Woo SL, Means AR, O'Malley BW. Partial purification of a progesterone-inducible messenger RNA (avidin) from hen oviduct. Endocrinology 1976; 99:315-25. [PMID: 939199 DOI: 10.1210/endo-99-1-315] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The messenger RNA (mRNA) for avidin, which represents less than 0.05% of the total cellular proteins, was partially purified from hen oviduct, and the presence of avidin mRNA was shown to depend upon prior stimulation by progesterone. A total nucleic acid extract was subjected to oligo (dT)-cellulose chromatography, followed by Sepharose 4B chromatography, preparative agarose gel electrophoresis, and sucrose gradient centrifugation. The relative purity of each preparation was assessed by translation in a wheat-germ system; avidin messenger RNA activity was measured by specific immunoprecipitation of synthesized proteins. Avidin mRNA was separated from the bulk of the total messenger RNA activity of the oviduct and from all ribosomal RNAs to produce greater than a 1000-fold enrichment of avidin mRNA activity compared with total cellular RNA. Based on the translation assay, the most highly purified fraction contained about 2.5% avidin messenger RNA. Avidin mRNA activity was absent in partially purified mRNA obtained from estrogen-stimulated chick oviducts, but was detected in oviducts following progesterone administration.
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506
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Akeson WH, Woo SL, Rutherford L, Coutts RD, Gonsalves M, Amiel D. The effects of rigidity of internal fixation plates on long bone remodeling. A biomechanical and quantitative histological study. ACTA ORTHOPAEDICA SCANDINAVICA 1976; 47:241-9. [PMID: 952210 DOI: 10.3109/17453677608991984] [Citation(s) in RCA: 104] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The effect of rigidity of internal fixation plates on long bone remodeling was studied using two types of plates with considerable differences in stiffness. The plated bones were subjected to bioengineering quantitative histological, and cortical thickness studies after 9 and 12 months. The biomechanical results, together with the quantitative histological measurements of the macroscopic architecture, showed that tissue characteristics of the plated bones were similar. However, because of the larger cortical area, the less regidly plated femora can sustain significantly higher loads and energy before failure. Cortical thickness measurements also showed that rigid plate immobilization results in thinning of the cortex of the underlying bone. The experimental results suggest that cortical bone remodels according to functional stress demands, and the osteoporosis secondary to rigid plate protection is consequent to thinking of its cortex.
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507
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Van NT, Holder JW, Woo SL, Means AR, O'Malley BW. Secondary structure of ovalbumin messenger RNA. Biochemistry 1976; 15:2054-62. [PMID: 1276125 DOI: 10.1021/bi00655a005] [Citation(s) in RCA: 39] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The secondary structure of highly purified ovalbumin mRNA was studied by automated thermal denaturation techniques and the data were subjected to computer processing. Comparative studies with 20 natural and synthetic model nucleic acids suggested that the secondary structure of ovalbumin mRNA possesses the following features: the extent of base pairing of ovalbumin mRNA is similar to that found in tRNAs or ribosomal RNAs; the secondary structure of ovalbumin mRNA is more thermolabile than any of the model compounds tested, including the copolymer poly(A-U); ovalbumin mRNA does not have extensive G-C rich stems as found in tRNAs or ribosomal RNAs; the base composition of the double-stranded regions reveals 54% G-C residues which was significantly higher than that noted in the whole molecule (approximately 41.5% G-C). The presence of 46% A-U pairs in short stems of about five base pairs would have a very large destabilizing effect on the secondary structure of ovalbumin mRNA. However, at 0.175 M monovalent cations and 36 degrees C most of the secondary structure of ovalbumin mRNA is preserved. These data suggest that the double-stranded regions in ovalbumin mRNA are of sufficient length to provide the necessary stability for maintaining the open loop regions in an appropriate conformation which may be required for the biological function of ovalbumin mRNA. Furthermore, the lability of the double-stranded regions in ovalbumin mRNA may also be important for the biological function of this mRNA.
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508
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Woo SL, Akeson WH, Coutts RD, Rutherford L, Doty D, Jemmott GF, Amiel D. A comparison of cortical bone atrophy secondary to fixation with plates with large differences in bending stiffness. J Bone Joint Surg Am 1976; 58:190-5. [PMID: 1254623] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Two internal-fixation plates with large differences in bending stiffness were applied to pairs of intact femora of six adult mongrel dogs to study the osteoporosis induced by rigid fixation. After nine and twelve months of plate application a significant, increased amount of bone atrophy was seen on the rigidly plated side. Biomechanical measurements of specimens from various segments of both femoral diaphyses showed the bones to have similar mechanical properties (as tissue), but different structural properties (as organ). These findings suggest that the osteoporosis due to rigid plate fixation occurs by thinning of the cortex rather than by reduction of the mechanical properties of the osseous tissue.
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509
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Monahan JJ, Harris SE, Woo SL, Robberson DL, O'Malley BW. The synthesis and properties of the complete complementary DNA transcript of ovalbumin mRNA. Biochemistry 1976; 15:223-33. [PMID: 55272 DOI: 10.1021/bi00646a034] [Citation(s) in RCA: 121] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The synthesis of a complementary DNA copy (cDNA) of hen ovalbumin mRNA using AMV RNA-directed DNA polymerase was studied under different conditions of salt, deoxyribonucleotide concentrations, temperature, and time. It was observed that in the absence of monovalent cation at 46 degrees C a complete transcript of ovalbumin mRNA could be effected by the enzyme. The minimum deoxyribonucleotide requirement for complete synthesis was 35 muM for dATP, dGTP, and dCTP and 200 muM dTTP. By a number of different experimental criteria which included sedimentation on alkaline sucrose gradients and electrophoresis in polyacrylamide gels containing 98% formamide, direct electron microscope visualization, and protection of ovalbumin [25I]mRNA from nuclease digestion it could be demonstrated that a considerable fraction of a complete mRNA transcript was indeed synthesized. The cDNA/ovalbumin mRNA hybrid had a Tm on hydroxylapatite of 92 degrees C, indicating the synthesis of a RNA transcript with a high fidelity. When such a complete ovalbumin [3H]cDNA was synthesized with a specific activity of 10(8) cpm/mug and hyfridized to an excess of chick DNA, the kinetics of hybridization indicated that the cDNA was comprised of a nonrepetitive sequence.
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510
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Woo SL, Akeson WH, Jemmott GF. Measurements of nonhomogeneous, directional mechanical properties of articular cartilage in tension. J Biomech 1976; 9:785-91. [PMID: 1022791 DOI: 10.1016/0021-9290(76)90186-x] [Citation(s) in RCA: 177] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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511
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Convery FR, Woo SL, Akeson WH, Amiel D, Malcom LL. Experimental hemarthrosis in the knee of the mature canine. ARTHRITIS AND RHEUMATISM 1976; 19:59-67. [PMID: 1252269 DOI: 10.1002/art.1780190110] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The knee joints of 14 skeletally mature mongrel dogs were subjected to a continuous hemarthrosis. Minimal morphologic changes of the articular cartilage did not occur until after 16 weeks. As early as 4 weeks, biochemical analyses showed a significant decrease in glycosaminoglycans (GAG) that became progressively more severe with time, whereas total collagen was not significantly altered until after 12 and 16 weeks. Bioengineering measurements of the experimental cartilage surfaces showed that the tissue becomes more deformable as well as less resistive to shear than the control at 8 weeks. These differences increased as the duration of hemarthrosis increased.
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512
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Akeson WH, Woo SL, Coutts RD, Matthews JV, Gonsalves M, Amiel D. Quantitative histological evaluation of early fracture healing of cortical bones immobilized by stainless steel and composite plates. CALCIFIED TISSUE RESEARCH 1975; 19:27-37. [PMID: 1201463 DOI: 10.1007/bf02563988] [Citation(s) in RCA: 77] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Internal fixation devices of less bending stiffness than conventional plates made of stainless steel or vitallium were compared with conventional plates in a study of fracture healing. The material for this investigation was a fine graphite fiber reinforced methyl methacrylate resin composite with a modulus of elasticity approximately ten times less than that of stainless steel. Osteotomies were performed on canine radii. Internal fixation was accomplished by means of a composite plate on the left side, and a stainless steel plate on the right. Clinical assessment, as well as biomechanical and quantitative histological techniques, were used to compare osteotomy healing of the two sides. At four months, all osteotomies had healed and the bioengineering tests showed radii from the two sides had equivalent strength. However, significantly less cortical porosity was found in the side with the composite plate (6.8 per cent), as compared to that of the stainless steel plated side (14 per cent). These results suggest that a less stiff fixation plate may have some advantage in the treatment of long bone fracture if there is no implant failure, and if union rates are equivalent.
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513
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514
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Woo SL, Rosen JM, Liarakos CD, Choi YC, Busch H, Means AR, O'Malley. Physical and chemical characterization of purified ovalbumin messenger RNA. J Biol Chem 1975; 250:7027-39. [PMID: 1158896] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Preparative agarose gel electrophoresis under denaturing conditions has been successfully employed to purify large quantities of ovalbumin mRNA from hen oviducts. The mRNA thus prepared is physically homogeneous based on its migration as a single component on electrophoresis in both analytical acid-urea agarose gels and formamide-containing, neutral polyacrylaminde gels; it also sediments as a single peak in sucrose gradients containing 70% formamide. The mRNA is chemically free of ribosomal RNA contamination since its oligonucleotide fingerprint map after complete T1 ribonuclease digestion contains no detectable specific large oligonucleotide markers of ribosomal RNAs. It is also not contaminated by other biologically active messenger RNAs because, when it is added to the cell-free wheat germ translation system, the only protein product synthesized is ovalbumin as analyzed by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate and specific immunoprecipitation. Ovalbumin mRNA has a nucleotide composition of 32.3% A, 21.0% G, 25.7% U, and 20.7% C [(A+U)/(G+C) equal 1.41]. The mRNA contains a heterogeneous poly(A) tract ranging from 20 to 140 residues with a number average chain length of 62 adenylate residues. The molecular weight of the sodium salt of the purified mRNA is approximately 650,000 +/- 63,000, corresponding to a chain length of 1890 +/- 180 nucleotides, as determined by electron microscopy under completely denaturing conditions. This value is in close agreement with the values obtained from: (a) sucrose gradient centrifugation in the presence of 70% formamide; (b) evaluation of poly(A) content in the mRNA and the number average chain length of its poly(A) tract; and (c) sedimentation velocity studies in the presence of 3% formaldehyde. When 125I-labeled ovalbumin mRNA is allowed to hybridize with a large excess of chick DNA, the observed kinetics of hybridization reveal no appreciable reaction between the mRNA and the repeated sequences of the chick DNA, although the mRNA appears to be approximately 600 nucleotides longer than necessary to code for ovalbumin. It thus appears that the entire ovalbumin mRNA is primarily transcribed from a unique sequence in the chick genome.
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515
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Woo SL, Rosen JM, Liarakos CD, Choi YC, Busch H, Means AR, O'Malley. Physical and chemical characterization of purified ovalbumin messenger RNA. J Biol Chem 1975. [DOI: 10.1016/s0021-9258(19)41035-1] [Citation(s) in RCA: 73] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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516
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Rosen JM, Woo SL, Comstock JP. Regulation of casein messenger RNA during the development of the rat mammary gland. Biochemistry 1975; 14:2895-903. [PMID: 1148182 DOI: 10.1021/bi00684a016] [Citation(s) in RCA: 135] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Casein mRNA was isolated and partially purified from RNA extracts of rat lactating mammary glands and translated in a teterologous cell-free protein synthesizing system derived from wheat germ. Casein mRNA activity was assayed by immunoprecipitation using a specific antiserum prepared against a mixture of the purified rat caseins. Properties of rat casein mRNA were examined using a variety of sizing techniques, including chromatography on Sepharose 4B, sedimentation on sucrose gradients after heat denaturation, and electrophoresis on 2.5% agarose gels in 6 M urea. Casein mRNA activity was found in an 8-16S region after gradient centrifugation with the peak occurring at 10.5 S. In addition, the binding of rat casein mRNA to dT-cellulose was examined. Only 40% of the total casein mRNA activity was selectively retained. A partial purification of casein mRNA was accomplished by a combination of these sizing and affinity chromatography techniques. In the purified preparations casein mRNA activity comprises approximately 90% of the total mRNA activity. Characterization of this material by agarose gel electrophoresis revealed two main bands of RNA at approximately 12 and 16 S, both containing casein mRNA activity. These mRNAs were of the correct size to code for two of the principal rat caseins of approximately 25,000 and 42,000 molecular weights. Casein mRNA and total mRNA activities were then compared in total RNA extracts at various stages of normal mammary gland development in the rat, i.e. during pregnancy, lactation, and involution following weaning. A selective induction of casein mRNA activity compared to total mRNA activity was found to occur during pregnancy and lactation. Moreover, a selective loss of activity was also observed during mammary gland involution. A surprisingly high level of casein mRNA activity was found in RNA extracts from early and midpregnant mammary glands.
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517
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Rosen JM, Chan L, Woo SL, Harris SE, Means AR, O'Malley BW. Effect of estrogen on the synthesis and processing of ovalbumin messenger RNA in the chick oviduct. BROOKHAVEN SYMPOSIA IN BIOLOGY 1975:320-32. [PMID: 1192242] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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518
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Woo SL, Matthews JV, Akeson WH, Amiel D, Convery FR. Connective tissue response to immobility. Correlative study of biomechanical and biochemical measurements of normal and immobilized rabbit knees. ARTHRITIS AND RHEUMATISM 1975; 18:257-64. [PMID: 1137613 DOI: 10.1002/art.1780180311] [Citation(s) in RCA: 165] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The biomechanical changes in rabbit knee contractures were measured after 9 weeks of immobilization. These results were correlated with the biochemical composition of periarticular connective knee tissue of the same knees. The loss of total hexosamine correlates significantly with joint stiffness on an animal-to-animal basis. Total hexosamine also correlates with the energy required cyclicly to flex and to extend the experimental joints. Of the individual glycosaminoglycan fractions, only hyaluronic acid showed significant correlation with the biomechanical data. The possible mechanism of contracture formation was postulated based on these results.
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519
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O'Malkey BW, Woo SL, Harris SE, Rosen JM, Means AR. Steroid hormone regulation of specific messenger RNA and protein synthesis in eucaryotic cells. J Cell Physiol 1975; 85:343-56. [PMID: 1123409 DOI: 10.1002/jcp.1040850403] [Citation(s) in RCA: 37] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Evidence is presented that the induction of specific proteins in the chick oviduct by the steroid hormones estrogen and progesterone, involves a primary effect at the level of gene transcription. The intracellular levels of mRNA's which code for the synthesis of the egg-white proteins, ovalbumin and avidin, have been quantitated in a heterologous protein synthesizing system. It is demonstrated that these levels are directly dependent upon the inducing steroid, estrogen or progesterone, respectively. Ovalbumin mRNA has been purified to apparent homogeneity. This ovalbumin mRNA was then used as a template for the synthesis of a complementary DNA copy catalyzed by the enzyme reverse transcriptase which was isolated from avian myeloblastosis virus. This radioactively labeled complementary DNA was used to demonstrate, by means of DNA excess hybridization, that the ovalbumin gene is represented only once in each haploid genome of the chick cell. Next the complementary DNA copy of the ovalbumin mRNA was used as a genetic probe to determine the precise number of sequences of ovalbumin mRNA present at any one time after the administration of estrogen. It was demonstrated that the unstimulated chick contained no sequences of ovalbumin mRNA. Within a very short period of time after estrogen is administered the ovalbumin sequences begin to appear and reach a steady state level of 140,000 molecules per tubular gland cell. It could also be calculated that each ovalbumin molecule is probably translated some 50,000 times during its life which explains why ovalbumin comprises some 60% of the total protein in the oviduct cell. Following withdrawal of the oviduct from estrogen treatment, ovalbumin mRNA sequences again drop to undetectable levels. However, following a single injection of estrogen to these withdrawn animals, new ovalbumin mRNA sequences could be detected within 30 minutes. These data suggest that estrogen controls the activity of the ovalbumin gene via a pure transcriptional control mechanism. It is also demonstrated that the efficiency of the complementary DNA as a means of quantitating specific mRNA sequences is some 1,000 times more sensitive than the best available in vitro translation system. Finally, the efficacy of four popular translation systems is compared. It is suggested that for initial studies involving hormonal control of mRNA levels, the translation system derived from wheat germ is the simplest and most sensitive.
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520
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Rosen JM, Woo SL, Holder JW, Means AR, O'Malley BW. Preparation and preliminary characterization of purified ovalbumin messenger RNA from the hen oviduct. Biochemistry 1975; 14:69-78. [PMID: 1109593 DOI: 10.1021/bi00672a012] [Citation(s) in RCA: 197] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Preparation of milligram amounts of purified ovalbumin mRNA was accomplished by a sequential combination of precise sizing techniques with the selective purification of the poly(A) containing RNA by either affinity chromatography or adsorption to nitrocellulose filters. Several new techniques were applied to the purification of ovalbumin mRNA including Sepharose 4B chromatography and agarose gel electrophoresis in the presence of 6 M urea at pH 3.5. All the procedures used were adapted on a preparative sacle to the fractionation of large quantities of RNA. The purity of the ovalbumin mRNA was assessed by several independent criteria. (1) Purified ovalbumin mRNA migrated as a single band during both agarose-urea and formamide-polyacrylamide gel electrophoresis at pH 3.5 and 7.4, respectively. A single absorbance peak containing all of the ovalbumin mRNA activity was also found using linear formamide-sucrose gradients. (2) Determination of both total mRNA activity and ovalbumin mRNA activity in the wheat germ cell-free translation assay revealed that 92% of the total peptides synthesized were specifically immunoprecipitable with an ovalbumin antiserum. (3) Analysis of the total peptides synthesizied in the wheat germ assay by sodium dodecyl sulfate polyacrylamide gel electrophoresis demonstrated the presence of a single radioactive peak that corresponded exactly to a specifically immunoprecipitable ovalbumin standard. Thus, based on these observations ovalbumin mRNA appears to be greater than 95% pure. A preliminary estimation of the molecular weight of purified ovalbumin mRNA by formamide-containing sucrose gradients yielded a value of 520,000 or approximately 1600 nucleotides. This value was considerably less than the value of 900,000 obtained by gel electrophoresis under denaturing conditions. Analysis of the poly(A) content by a hybridization assay with (3H)poly(U) revealed the presence of a poly(A) region containing approximately 70 adenosine residues. Thus, the size of the ovalbumin mRNA is considerably greater than that required to code for a protein of 387 amino acids. The availability of large quantities of purified ovalbumin mRNA should now permit a more thorough analysis of its physical and chemical properties.
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521
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Woo SL, Akeson WH, Levenetz B, Coutts RD, Matthews JV, Amiel D. Potential application of graphite fiber and methyl methacrylate resin composites as internal fixation plates. JOURNAL OF BIOMEDICAL MATERIALS RESEARCH 1974; 8:321-38. [PMID: 4426908 DOI: 10.1002/jbm.820080513] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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522
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Martelo OJ, Woo SL, Davie EW. Phosphorylation of Escherichia coli RNA polymerase by rabbit skeletal muscle protein kinase. J Mol Biol 1974; 87:685-96. [PMID: 4372361 DOI: 10.1016/0022-2836(74)90078-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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523
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Gillam SS, Woo SL, Woolf LI. The isolation and properties of phenylalanine hydroxylase from rat liver. Biochem J 1974; 139:731-9. [PMID: 4854920 PMCID: PMC1166337 DOI: 10.1042/bj1390731] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Phenylalanine hydroxylase was prepared from rat liver and purified 200-fold to about 90% purity. All the enzymic activity of the liver appeared in a single protein of mol.wt. approx. 110000, but omission of dithiothreitol and of a preliminary filtration step to remove lipids resulted in partial conversion into a second enzymically active protein of mol.wt. approx. 250000. The K(m) and V(max.) values of the enzyme for phenylalanine, p-fluorophenylalanine and dimethyltetrahydropterin were measured; p-chlorophenylalanine inhibited the enzyme by competing with phenylalanine. Disc gel electrophoresis at pH7.2 showed a single protein band containing all the enzymic activity, but at pH8.7 the enzyme dissociated into two inactive fragments of similar but not identical molecular weight. The molecule of phenylalanine hydroxylase contained two atoms of iron, one atom of copper and one molecule of FAD; molybdenum was absent. Treatment with chelating agents showed that both non-haem iron and copper were necessary for enzymic activity. The molecule contained five thiol groups, and thiol-binding reagents inhibited the enzyme. Catalase or peroxidase enhanced enzymic activity fivefold; it is postulated that catalase (or other peroxidase) plays a part in the hydroxylation reaction independent of the protection by catalase of enzyme and cofactor from inactivation by a hydroperoxide.
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524
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Woo SL, Gillam SS, Woolf LI. The isolation and properties of phenylalanine hydroxylase from human liver. Biochem J 1974; 139:741-9. [PMID: 4854919 PMCID: PMC1166338 DOI: 10.1042/bj1390741] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Phenylalanine hydroxylase was prepared from human foetal liver and purified 800-fold; it appeared to be essentially pure. The phenylalanine hydroxylase activity of the liver was confined to a single protein of mol.wt. approx. 108000, but omission of a preliminary filtration step resulted in partial conversion into a second enzymically active protein of mol.wt. approx. 250000. Human adult and full-term infant liver also contained a single phenylalanine hydroxylase with molecular weights and kinetic parameters the same as those of the foetal enzyme; foetal, newborn and adult phenylalanine hydroxylase are probably identical. The K(m) values for phenylalanine and cofactor were respectively one-quarter and twice those found for rat liver phenylalanine hydroxylase. As with the rat enzyme, human phenylalanine hydroxylase acted also on p-fluorophenylalanine, which was inhibitory at high concentrations, and p-chlorophenylalanine acted as an inhibitor competing with phenylalanine. Iron-chelating and copper-chelating agents inhibited human phenylalanine hydroxylase. Thiol-binding reagents inhibited the enzyme but, as with the rat enzyme, phenylalanine both stabilized the human enzyme and offered some protection against these inhibitors. It is hoped that isolation of the normal enzyme will further the study of phenylketonuria.
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525
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Akeson WH, Woo SL, Amiel D, Matthews JV. Biomechanical and biochemical changes in the periarticular connective tissue during contracture development in the immobilized rabbit knee. Connect Tissue Res 1974; 2:315-23. [PMID: 4281375 DOI: 10.3109/03008207409152261] [Citation(s) in RCA: 42] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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526
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Woo SL, Harris SE, Rosen JM, Chan L, Sperry PJ, Means AR, O'Malley BW. Use of Sepharose 4B for preparative scale fractionation of eukaryotic messenger RNA's. PREPARATIVE BIOCHEMISTRY 1974; 4:555-72. [PMID: 4475423 DOI: 10.1080/00327487408061554] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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527
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Akeson WH, Woo SL, Amiel D, Coutts RD, Daniel D. The connective tissue response to immobility: biochemical changes in periarticular connective tissue of the immobilized rabbit knee. Clin Orthop Relat Res 1973:356-62. [PMID: 4269190 DOI: 10.1097/00003086-197306000-00039] [Citation(s) in RCA: 164] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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528
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Woo SL, Kobayashi AS, Lawrence C, Schlegel WA. Mathematical model of the corneo-scleral shell as applied to intraocular pressure-volume relations and applanation tonometry. Ann Biomed Eng 1972; 1:87-98. [PMID: 4668693 DOI: 10.1007/bf02363420] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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529
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Woo SL, Kobayashi AS, Schlegel WA, Lawrence C. Nonlinear material properties of intact cornea and sclera. Exp Eye Res 1972; 14:29-39. [PMID: 5039845 DOI: 10.1016/0014-4835(72)90139-x] [Citation(s) in RCA: 199] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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530
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Coletti JM, Akeson WH, Woo SL. A comparison of the physical behavior of normal articular cartilage and the arthroplasty surface. J Bone Joint Surg Am 1972; 54:147-60. [PMID: 4262361] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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531
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Kobayashi AS, Woo SL, Lawrence C, Schlegel WA. Analysis of the corneo-scleral shell by the method of direct stiffness. J Biomech 1971; 4:323-30. [PMID: 5133352 DOI: 10.1016/0021-9290(71)90053-4] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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532
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Martelo OJ, Woo SL, Reimann EM, Davie EW. Effect of protein kinase on ribonucleic acid polymerase. Biochemistry 1970; 9:4807-13. [PMID: 4320542 DOI: 10.1021/bi00826a027] [Citation(s) in RCA: 86] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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533
|
Wiederhielm CA, Kobayashi AS, Stromberg DD, Woo SL. Structural response of relaxed and constricted arterioles. J Biomech 1968; 1:259-70. [PMID: 16329430 DOI: 10.1016/0021-9290(68)90021-3] [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: 11/21/2022]
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