Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| an antimutator deoxyribonucleic acid polymerase. i. purification and properties of the enzyme. | the dna polymerase induced by an antimutator t4 phage has been purified to apparent homogeneity and has been compared to the wild type polymerase. the mutant enzyme resembles the wild type in thermal stability, ph optimum, salt activation, divalent metal ion requirement, inhibition by a sulfhydryl reagent, and apparent affinity for dna. however, the mutant enzyme differs from the wild type in its 8-fold higher 3'-exonuclease activity and in its decreased apparent affinity for deoxyribonucleoside ... | 1976 | 770466 |
| an antimutator deoxyribonucleic acid polymerase. ii. in vitro and in vivo studies of its temperature sensitivity. | upon infection of escherichia coli with the temperature-sensitive bacteriophage t4 mutant, l141, at 43 degrees, dna polymerase activity is induced, yet there is a marked decrease in dna synthesis. temperature shift experiments of infected cultures show dramatic changes in the rate of dna synthesis, while the polymerase activity in extracts remains constant. unlike most temperature-sensitive systems in which the lesion can be traced to an unstable enzyme, l141 provides a unique example in which t ... | 1976 | 770467 |
| studies on phage internal proteins: formation of internal protein - t2 dna complexes in vivo. | internal proteins, synthesized in t2-infected escherichia coli b cells were recovered from bacterial membranes during the early stages of infection. approx. 15 min after the onset of infection, t2 and t4 internal proteins were released from the bacterial membranes and sedimented along with newly synthesized phage dna. internal protein-dna complexes were also obtained by chromatography on hydroxylapatite columns. internal proteins were not released from bacterial membranes after infection with am ... | 1976 | 772169 |
| dna crosslinks, single-strand breaks and effects on bacteriophage t4 survival from tritium decay of (2-3h)adenine, (8-3h)adenine and (8-3h)guanine. | 1976 | 772217 | |
| on a bacteriophage t3 and t4 receptor region within the cell wall lipopolysaccharide of escherichia coli b. | 1976 | 772219 | |
| cooperative control of translational fidelity by ribosomal proteins in escherichia coli. iii. a ram mutation in the structural gene for protein s5 (rpx e). | the effect on translational fidelity of a particular mutation in the gene coding for protein s5(rpxe) has been investigated. this mutation has the opposite effect of a restrictive stra mutation; in vivo, it relieves the restriction imposed by stra on the suppression of t4 nonsense mutants and results in hypersensitivity to streptomycin; in vitro, the presence of the altered s5 protein in 30s ribosomes results in increased intrinsic misreading. it is concluded that this mutation, ramc319, acts as ... | 1976 | 772415 |
| the role of thiol groups in nucleoside transport. | (1) the inactivation of various forms of nucleoside transport with reagents blocking thiol groups was studied in whole cells of e. coli b. no positive correlation between the efficiency of active transport and the extent or rate of inactivation could be demonstrated. (2) the most efficient constitutive nucleoside-transporting system was found to comprise a specific thiol component characterized by low rate of inactivation with n-ethylmaleimide; the less efficient inducible transport and the faci ... | 1976 | 772419 |
| a morphologically recognizable marker for scanning immunoelectron microscopy. i. t4-bacteriophage. | 1976 | 772950 | |
| [cyclic rearrangements in the incomplete genome of t4d phage transferred into a cell during a injections of dna]. | the genome structure of phage t4 chromosome fragments obtained by the method of dna interrupted injection is studied directly. anfragment population is shown by homogeneous in sizes. the fragment sizes are proved to the indentical to sizes. the fragment sizes are proved to be identical to sizes expected from the method conditions. the individual fragment genomes are shown to be cyclic gene permutations uniformly distributed on the map of physical distances between genes. the results suggest that ... | 1975 | 773754 |
| [a genetic and physiologic study of mutations of t4 phage suppressing the lysis defect of gene stii mutants]. | a new gene rvi phage t4b is found. mutations rvi belong to the class of r-mutations of t4b. mutations rvi do not show the lysis inhibition after superinfection and determine the r-morphology of plaques on escherichia coli cr63 lawn. mutations rvi are gene-specific suppressors of stii lysis defect, but do not suppress the e lysis defect. alleles rvi and rvi+ are co-dominated with regard to the ability to suppress the stii lysis defect. the suggest the stoichiometric character of rvi gene function ... | 1975 | 773757 |
| [the influence of bacterial genes recb, reca, exr and pola on t4 phage dna transfection of lysozyme spheroplasts of escherichia coli]. | the transfection efficiency of t4 phage dna of escherichia coli spheroplasts, carrying mutations in four genes, involved in recombination and reparation (recb, reca, exr, pola), is studied. recb- and reca- mutations increased the phage yield during transfection, and exr- and pola- mutations decreased it. reca- mutation is suggested to influence on spheroplasts membrane state, resulting in more efficient replication of transfecting phage dna. | 1976 | 773763 |
| lethality and double-strand scissions from 14c decay in the dna of micro-organisms. | 14c-2-thymidine was incorporated into the dna of e. coli b/r and of coliphage t4. the labelled organisms were stored for several years at -196 degrees c. both were periodically assayed for loss of viability, and the coliphage also for the appearance of double-strand breaks (dsbs) in dna. e. coli b/r exhibited a survival curve with a substantial initial shoulder, extrapolation number 5-2 +/- 2-3, and a final exponential portion corresponding to a lethal efficiency per 14c decay per 2-5 x 10(9) da ... | 1976 | 773874 |
| dexamethasone suppression of serum t3 and t4. | dexamethasone (2 mg q6h for 48 h) decreased serum t3 in normal and athyreotic subjects, and decreased t4 in normal subjects. dexamethasone probably alters secretion and peripheral metabolism of thyroid hormones. | 1976 | 773952 |
| folding and capsomere morphology of the p23 surface shell of bacteriophage t4 polyheads from mutants in five different head genes. | 1976 | 775106 | |
| bacteriophage t4 polyheads: crystallographic and geometrical conventions. | 1976 | 775107 | |
| function of gene 49 of bacteriophage t4. ii. analysis of intracellular development and the structure of very fast-sedimenting dna. | with the exception of mutants in gene 49, all mutants in phage t4 defective in the process of head filling accumulate a normal replicative dna intermediate of 200s. mutants in gene 49 produce a very fast-sedimenting (vfs) dna with s values of greater than 1,000s. the intracellular development of the vfs-dna generated in gene 49-defective phage-infected cells was followed by sedimentation analysis of crude lysates on neutral sucrose gradients. it was observed that the production of a 200s replica ... | 1976 | 775128 |
| function of gene 49 of bacteriophage t4. i. isolation and biochemical characterization of very fast-sedimenting dna. | very fast-sedimenting dna was isolated from cells after infection with gene 49 defective phage t4. this dna appeared membrane bound throughout the time after infection and could be isolated either in the membrane-bound form (m-dna) or free of membrane (released dna) depending on the lysis procedure. released dna formed complexes of marked stability with sedimentation velocities between 1,400s and 2,100s. these complexes did not seem to contain material other than dna. this was concluded from the ... | 1976 | 775132 |
| thiolutin resistant mutants of escherichia coli are they rna chain initiation mutants? | four mutants of escherichia coli kl16 resistant to the antibiotic thiolutin have been isolated. this drug was earlier reported to be an inhibitor of rna chain elongation. the first mutant, tlri, is resistant only in rich or partially rich media: it can, however, grow in minimal medium containing the drug with a very long doubling time. the other mutants tlrii, tlriiia and tlriiib are resistant in rich as well as minimal media. beta-galactosidase could not be induced in tlri and tlrii in the pres ... | 1976 | 775314 |
| a study of possible mechanisms of the rna-polymerase involement in mutagenesis in phage t4. | spontaneous and induced mutation frequencies of phage t4 have been measured in escherichia coli strains containing altered rna-polymerase. in the strain e. coli rif-r stl-r, with double rna-polymerase mutation, spontaneous reversion rates were increased in different mutants of phage t4. the study of base analogues mutagenesis in ruv mutants of phage t4 has shown that the introduction of rna-polymerase mutations did not increase reversion rates in a mutant of frame-shift type but enhanced the rat ... | 1976 | 775319 |
| induced mutagenesis in bacteriophage t4 growing in strains of e. coli with altered rna-polymerase. | enhanced reversion frequencies of t4 r mutants in e. coli strains with altered rna polymerase have been obtained. the results reported have confirmed previous data on the effect of rna-polymerase on the process of mutagenesis [2]. no such effect has been found in the course of studies of the recombination process. | 1976 | 775324 |
| enzymatic synthesis of duplex circular phix174 dna containing phosphoramidate bonds in the (-) strand. | duplex circular phix174 dna (rf i) containing some phosphoramidate links in the backbone chain of the (-) strand was synthesized by reaction of 5'-amino-5'-deoxythymidine 5'-triphosphate, dctp, dgtp, and 3h-datp with dna polymerase i and dna ligase (t4) on a (+) strand phix174 amber 3 dna template. the yield of duplex dna was higher when dttp was included along with the amino analog in the initial reaction system or was added late in the synthesis. rf i dna was observed as a rapidly sedimenting ... | 1976 | 775443 |
| [functions of bacteriophage t4 rii genes. preparatory isolation and several properties of riib protein]. | a method of preparative isolation of membrane riib protein from bacteriophage t4 is worked out. conditions are found to maximal riib protein accumulation in membranes of e. coli cells infected with bacteriophage t4. the membrane isolation by ultracentrifugation is substituted with their sedimentation from polyethyleneglycol solutions by low-speed centrifugation. a fraction, enriched with riib protein, is obtained using the treatment of cell walls with detergents. preparative polyacrylamide gel e ... | 1976 | 776232 |
| phleomycin-stimulated solubilization of deoxyribonucleic acid in escherichia coli. ii. inhibition of solubilization by bacteriophage t4. | phleomycin-stimulated solubilization of escherichia coli dna is inhibited by infecting the cells with mutants of bacteriophage t4 before treatment with the antibiotic, inhibition requiring phage-specified protein synthesis. two different modes of inhibition can be differentiated by infecting with mutants which are defective in an early state (gene den a-; endonuclease ii-independent inhibition) or a late stage (gene 46-; endonuclease ii-dependent inhibition) of phage-directed degradation of host ... | 1976 | 776373 |
| [preparation of functioning recombinant (hybrid) dna molecules in vitro (genetic engineering experiments)]. | in this paper we describe the preparation of hybrid plasmid consisting of cole1 dna and dna of r6k plasmid. cole1 plasmid represents a circular dna with the molecular weight of 4,2-10(6) daltons. it determines colicine synthesis e1, has relaxed control of replication and is present in the cell in several dozens copies. transmissive plasmid b6k represents a circular dna molecule with the molecular weight of 28-10(6) daltons. it confers the resistance to amplicillin and streptomycin and belongs to ... | 1975 | 776738 |
| altered properties of deoxyribonucleic acid polymerase i isolated from the membrane of bacteriophage t4-infected escherichia coli. | previous studies have shown that a large fraction of the host cell deoxyribonucleic acid (dna) polymerase i (ec 2.7.7.7) becomes associated with the cell membrane shortly after infection with bacteriophages t4 and t7. the present investigation of the bound enzyme revealed that the polymerase activity can be eluted from the membrane with chelating agents, and that the material thus obtained shows many properties that distinguish it from purified dna polymerase i. these include its chromatographic ... | 1976 | 776929 |
| lipopolysaccharide-deficient, bacteriophage-resistant mutants of escherichia coli k-12. | bacteriophage-resistant mutants isolated and classified in a previous study were examined for alterations in their lipopolysaccharide (lps) composition, and properties likely to be affected by alterations in lps composition were studied. it was found that many of the mutants of the ktw (k2-resistance), ttk (t2, t4, or k19 resistance), bar (bacteriophage), wrm (wide-range mutants), and miscellaneous resistance groups were altered in their response to a series of antibiotics and to two lps-specifi ... | 1976 | 776951 |
| cleavage of t4-induced proteins during phage morphogenesis: characterization of peptides. | polypeptides of low mol. wt. have been extracted from t4 coliphages and from escherichia coli b cells infected with a wild type and various amber mutants of bacteriophage t4. six peptides were fractionated by chromatography on phosphocellulose: three of them were cleaved from proteins synthesized late in infection and related to phage head. the remaining three peptides have been shown to arise from early-labelled phage-induced proteins. two of these six small petide fragments were found in the h ... | 1976 | 778336 |
| genes 46 and 47 of phage t4: possible compensation for loss of their function. | the gene 46 and 47 functions of phage t4 are required for normal dna replication, recombination, u.v. repair and host dna breakdown, and yet am mutants defective in these genes characteristically form tiny plaques on escherichia coli strains lacking an am suppressor. our results imply that this limited growth is not due to misreading of am codons or partial function of nearly complete poly-peptides terminated at the am mutation. thus it appears that genes 46 and 47 are not entirely essential, pe ... | 1976 | 778337 |
| purification of a proteolytic enzyme from t4-infected escherichia coli cells. | 1976 | 779237 | |
| t4 dna injection. i. growth cycle of a gene 2 mutant. | 1976 | 779242 | |
| t4 dna injection. ii. protection of entering dna from host exonuclease v. | 1976 | 779243 | |
| genetic analysis of t4 tail fiber assembly. ii. bacterial host mutants that allow bypass of t4 gene 57 function. | 1976 | 779244 | |
| [immunochemical and molecular biological characteristics of dysentery phages]. | molecular organization of dna of six dysentery phages was studied for their classification. the pattern of glucosilation of their dna was determined by an immunochemical method and the test of competitive hybridization established the degree of homology of these dna in relation to t4 phage dna. four of the phages (ddvi, zonne "gorkyi" zonne "czechoslovakia", zonne "poland") were shown to belong to the group of t-even phages by their pattern of dna glucosilation and by their capacity to inhibit ... | 1976 | 779271 |
| nucleotide clusters in deoxyribonucleic acids. xiii. sequence analysis of the longer unique pyrimidine oligonucleotides of bacteriophage s13 dna by a method using unlabeled atarting oligonucleotides. | a method has been designed for sequence analysis of unlabeled oligodeoxynucleotides of chain length up to 20 nucleotides with no restriction on base composition. the unlabeled oligonucleotide preparation, is partially degraded with spleen exonuclease to give a series of products each differing in size by one nucleotide. the oligonucleotides in the digest are 5'-32 p terminally labeled with [psi-32] p atp and t4 polynucleotide kinase, the excess atp removed by chromatography on sephadex g-25 then ... | 1976 | 779845 |
| studies on the structure of intracellular bacteriophage t4 dna. | 1976 | 781263 | |
| properties and structure of a gene 24-controlled t4 giant phage. | 1976 | 781276 | |
| terminal cross-linking of dna strands by a mixture of exonuclease iii of escherichia coli and polynucleotide ligase of bacteriophage t4. | 1976 | 781281 | |
| on the lack of host-cell reactivation of uv-irradiated phage t5 ii. further characterization of the repair inhibition exerted by t5 infection. | experiments reported in the preceding paper [4] had shown that host-cell reactivation (hcr) of uv-irradiated phage t1 in excision-repair proficient escherichia coli cells is inhibited by superinfection with phage t5. theoretical considerations have led to predictions concerning the dependence of repair inhibition on the multiplicity of superinfecting t5 phage and on the uv fluence to which they were exposed. these predicitions have been supported by experimental results described in this paper. ... | 1976 | 781530 |
| cleavage of t4 species i ribonucleic acid by escherichia coli ribonuclease iii. | t4 species i rna, a molecule 140 nucleotides in length with some structural features very much like a trna, is specifically cleaved by an enzymatic activity in escherichia coli extracts to give three segments with 19, 48 and 73 nucleotides. we report the purification and characterization of the e. coli rnase which cleaves two 3' phosphodiester bonds of t4 species i rna. this reaction has many properties in common with those catalyzed by e. coli rnase iii, although the optimal salt conditions for ... | 1976 | 781626 |
| translation of a stable mrna fraction from sporulating cells of bacillus thuringiensis in a cell-free system from escherichia coli. structural homologies between the native crystal protein and the products synthesized in vitro. | stable messenger rnas from sporulating cells of bacillus thuringiensis were translated in vitro in cell free system from e. coli. the mrna fraction used was extracted from cells treated at t4 of sporulation time with rifampicin for 10 minutes at 30degreesc. this stable-mrna enriched fraction directed the synthesis of polypeptides showing a size distribution up to 40,000 daltons. structural homologies between the in vitro products labeled with [3h]-valine and the native crystal protein labeled wi ... | 1976 | 782551 |
| inherited hypothyroidism. | familial hypothyroidism results from both thyroidal and extrathyroidal dysfunction. specific intrathyroidal abnormalities in thyroid hormone synthesis causing goitrous hypothyroidism are iodide trap defect, organification defect, "coupling" defect, iodoprotein defect, and dehalogenase defect. the diagnostic studies for each are outlined utilizing radioiodine(131i) studies. other causes of cretinism include failure of the thyroid gland to respond to tsh and lack of pituitary tsh (or hypothalamic ... | 1976 | 782770 |
| effect of thyroid status on spontaneous and induced surges of luteinizing hormone. | this study was designed to describe the effects of thyroid status on the preovulatory surge of lh and to determine the site(s) at which these effects are exerted. the treatment of normal 4-day cycling rats with a hyperthyroid dose of thyroxine (t4, 20 mug/100 g bw/day) for 8 days resulted in surges of lh on proestrus which were depressed to 25% of control levels. in ovariectomized (ov) or ovariectomized-thyroidectomized (ov-tx) rats maintained on a physiological regimen of t4 (2 mug/100 gbw/day) ... | 1976 | 782856 |
| preparation and specificity of endonuclease iv induced by bacteriophage t4. | bacteriophage-t4-induced endonuclease iv suitable for dna sequence analysis has been prepared by a modified and easily reproducible method. the specificity of t4-induced endonuclease iv has been investigated in order to verify whether this enzyme exhibits a single nucleotide recognition or a short sequence recognition. the 5'-terminal dinucleotides and 3'-terminal nucleotides of oligonucleotides released by t4-induced endonuclease iv from three single-stranded dnas (from bacteriophages phix174, ... | 1976 | 782881 |
| [detection of the products of several t4b phage genes among the proteins of infected escherichia]. | proteins of wild-type phate t4 and its mutants in genes rii, su(30), stii, stiii, rvi-39 and 60 are studied by means of polyacrylamide gel electrophoresis in the presence of sodium dodecylsulphate of membrane fractions and lysates of infected bacteria. physiological studies of mutants in these genes carried out by the authors and other investigators allow to suggest that when functions are realized, the products of these genes interact with the plasmatic membrane of the infected bacteria. the pr ... | 1976 | 783009 |
| effect of amiodarone on serum triiodothyronine, reverse triiodothyronine, thyroxin, and thyrotropin. a drug influencing peripheral metabolism of thyroid hormones. | 2-n-butyl-3-(4'-diethylaminoethoxy-3',5'-diiodobenzoyl)-benzofurane (amiodarone), a drug used in arrythmias and angina pectoris, contains 75 mg of organic iodine/200 mg active substance. four studies were performed to test its effect on thyroid hormone metabolism: (a) nine male subjects were treated with 400 mg of amiodarone for 28 days; (b) five male subjects received, for the same period of time, 150 mg of iodine in the form of lugol's solution; (c) five subjects received 300 mug l-thyroxine ( ... | 1976 | 783194 |
| neutrophil function in children with kwashiorkor. | peripheral blood polymorphonuclear neutrophil (pmn) function has been investigated for 46 children with kwashiorkor (without overt infection) in the ivory coast, west africa. in vitro chemotactic response, candidacidal activity, and kinetic studies of metabolism during phagocytosis have been performed. postphagocytic morphological events were evaluated by electron microscopy. the reduction of nitroblue tetrazolium (nbt), measurement of enzyme activities, activity of glycolysis, and hexose monoph ... | 1976 | 784886 |
| early bacteriophage t4 transcription. a diffusible product controls riia and riib rna synthesis. | 1976 | 785005 | |
| replication of bacteriophage t4 dna in vitro. i. basic properties of the system. | a new in vitro system for t4 dna replication was developed by concentrating cell lysates on cellophane disks. the time course of [3h]dttp incorporation into dna by the system was separated into two phases: one was a very rapid incorporation which was terminated within 2 min (phase i reaction), and the other was a slow but continuous incorporation thereafter (phase ii reaction). more than half of the phase i reaction product was escherichia coli dna, but the phase ii reaction was mostly t4 dna. p ... | 1976 | 785023 |
| [influence of proteins bound to single-stranded dna on rna and poly(a) synthesis. ii. protein--product of t4 phage gene 32]. | it has been shown that the protein product of t4 bacteriophage gene 32 (protein 32) completely prevents rna and poly(a) synthesis on the denatured dna as a template at the protein/dna ratio about 13:1. under the same conditions protein 32 has no effect on these syntheses on the native dna and inhibit poly(a) synthesis with oligo(dt)9 and oligo(dt)12 as a template, preventing binding of enzyme with oligonucleotide. it is possible that the unwinded regions of double-stranded dna within transcripti ... | 1976 | 785239 |
| hypothyroidism. | we found biochemical evidence of hypothyroidism (low t3 and t4 and elevated tsh) in azotemic patients. hemodialysis did not correct the hypothyroidism but renal transplantation did. the hypothyroidism is probably a consequence of impaired thyroidal elaboration of thyroid hormone, as well as decreased peripheral conversion of t4 to t3. the impaired thyroidal gland function may be secondary to the increased concentration of aryl acids found in chronic renal disease. | 1975 | 785453 |
| in vitro system for induction of delayed early rna of bacteriophage t4. | concentrated lysates of escherichia coli that had been infected with bacteriophage t4 in the presence of chloramphenicol show the same restriction of transcription in vitro as is found in vivo. restricted lysates can be complemented with lysates from infected cells to induce production of delayed early rna. complementation takes place between the rna polymerase of the restricted lysate and the dna of the unrestricted lysate. we present evidence that delayed early rna in these lysates is initiate ... | 1976 | 785471 |
| head length control in t4 bacteriophage morphogenesis: effect of canavanine on assembly. | 1976 | 786254 | |
| [localization of e. coli cell membrane regions for binding and initiation of bacteriophage t4 dna replication]. | 1976 | 786573 | |
| doublet frequencies and codon weighting in the dna of escherichia coli and its phages. | a compilation of nucleic acid sequences from e. coli and its phages has been analysed for the frequency of occurrence of nearest neighbour base doublets and codons. several statistically significant deviations from random are found in both doublet and codon frequencies. the deviations in e. coli also appear to occur in lambda and in the coat protein gene of ms2, whereas t4 and other parts of the ms2 genome show different sequence properties. these and other findings are discussed in relation to ... | 1976 | 787545 |
| properties of condensed bacteriophage t4 dna isolated from escherichia coli infected with bacteriophage t4. | methods developed for isolating bacterial nucleoids were applied to bacteria infected with phage t4. the replicating pool of t4 dna was isolated as a particle composed of condensed t4 dna and certain rna and protein components of the cell. the particles have a narrow sedimentation profile (weight-average s=2,500s) and have, on average, a t4 dna content similar to that of the infected cell. their dimensions observed via electron and fluorescence microscopy are similar to the dimensions of the int ... | 1976 | 787557 |
| phage t4 infection restricts rrna synthesis by e. coli rna polymerase. | rna polymerase from t4 infected cells supplemented with e. coli sigma polypeptide has a lower affinity for rrna promoters than rna polymerase from uninfected cells. the pattern of transcription by the phage modified polymerase is qualitatively similar to that of the vegetative polymerase in the presence of ppgpp. we suggest that e. coli polymerase holoenzyme normally exists in at least two conformational states, one with a high affinity for rrna promoters and another with a low affinity, and tha ... | 1976 | 787764 |
| conversion of escherichia coli rna polymerase to a template independent enzyme. | preparations of rna polymerase (e.c.2.7.7.6) from uninfected escherichia coli, t4 infected escherichia coli, and acinetobacter calcoaceticus when centrifuged in sucrose gradients in the absence of magnesium ions gave rise to five peaks, all of which were able to form polymers from ribonucleoside 5'-triphosphates in the absence of template or primer. all of the peaks obtained from the escherichia coli enzyme appeared to contain the subunit alpha and beta and, in addition, polypeptides which appe ... | 1976 | 787928 |
| dna elongation rates and growing point distributions of wild-type phage t4 and a dna-delay amber mutant. | 1976 | 789903 | |
| replicative bacteriophage dna synthesis in plasmolyzed t4-infected cells: evidence for two independent pathways to dna. | bacteriophage t4-infected escherichia coli rendered permeable to nucleotides by sucrose plasmolysis exhibited two apparently separate pathways or channels to t4 dna with respect to the utilization of exogenously supplied substrates. by one pathway, individual labeled ribonucleotides, thymidine (tdr), and 5-hydroxymethyl-dcmp could be incorporated into phage dna. incorporation of each of these labeled compounds was not dependent upon the addition of the other deoxyribonucleotide precursors, sugge ... | 1976 | 789911 |
| polymerization of oligodeoxythymidylates and oligoriboadenylates catalyzed by t4 polynucleotide ligase and their use as analytical markers in polyacrylamide-gel electrophoresis. | 1976 | 790999 | |
| purification and electrophoretic assay of t4-induced polynucleotide ligase for the in vitro construction of recombinant dna molecules. | 1976 | 791000 | |
| phleomycin-induced solubilization of deoxyribonucleic acid in uninfected and t bacteriophage-infected escherichia coli b. | phleomycin (pm) induces rapid solubilization of deoxyribonucleic acid (dna), inhibition of cellular mass increase, and loss of viability when added either to growing cultures of escherichia coli b or an endonuclease i-defective derivative of b. nonetheless, bacteriophage of the t-even series are produced, albeit to a reduced extent, when pm is added with phage or after infection to e. coli cells. bacteriophage t4 infection inhibits the ability of pm to bring about the solubilization of dna; this ... | 1976 | 791086 |
| a functional requirement for modification of the wobble nucleotide in tha anticodon of a t4 suppressor trna. | temperature-sensitive mutants of e. coli have been isolated which restrict the growth of strains of bacteriophage t4 which are dependent upon the function of a t4-coded amber or ochre suppressor transfer rna. one such mutant restricts the growth of certain ochre but not amber suppressor-requiring phage. analysis of the t4 trnas synthesized in this host revealed that many nucleotide modifications are significantly reduced. the modifications most strongly affected are located in the anticodon regi ... | 1976 | 791507 |
| dna "melting" proteins. ii. effects of bacteriophage t4 gene 32-protein binding on the conformation and stability of nucleic acid structures. | bacteriophage t4-coded gene 32-protein is an essential component of the t4 replication and recombination systems. alberts and co-workers (alberts, b.m., amodio, f.j., jenkins, m., gutmann, e.d., and ferris, f.l. (1968) cold spring harbor symp. quant. biol. 33, 289-305) have shown that the major physiological activity of the protein involves preferential and cooperative binding to single-stranded dna. in this paper, the physiochemical parameters characterizing this "melting" protein system are qu ... | 1976 | 791945 |
| dna "melting" proteins. iii. fluorescence "mapping" of the nucleic acid binding site of bacteriophage t4 gene 32-protein. | the intrinsic tryptophan fluorescence of bacteriophage t4-coded gene 32-protein is found to be partially quenched on binding a variety of mono-, oligo-, and polynucleotides. this phenomenon is exploited to partially "map" the nucleic acid binding site of the protein. the intrinsic fluorescence spectrum of the protein peaks at about 347 nm, compared to 359 nm for the fully solvated model fluorophore, n-acetyl-l-tryptophanamide. nucleotide binding, or collisional quenching by iodide ion, reduces t ... | 1976 | 791946 |
| regulation of gene 32 expression during bacteriophage t4 infection of escherichia coli. | the gene 32 protein of the bacteriophage t4 plays an important role in genetic recombination, dna repair, and dna replication; the protein functions in these processes by virtue of a strong binding capacity for single-stranded dna. during infections of escherichia coli by bacteriophage carrying amber of temperature-sensitive mutations in gene 32, the altered gene 32 protein (that is, the amber fragment of the missense polypeptide) is synthesized at greatly elevated rates. during infections by ph ... | 1976 | 791947 |
| translational, autogenous regulation of gene 32 expression during bacteriophage t4 infection. | functional half-life measurements of the bacteriophage t4 gene 32 messenger rna indicate that this mrna is extremely stable. regulation of gene 32 expression at the transcriptional level cannot account for the rapidity with which p32 synthesis can be repressed. furthermore, derepression of p32 synthesis occurs in the presence of rifampicin, a drug which inhibits transcriptional initiation. in addition, t4-infected cultures in which p32 expression is repressed possess almost as much gene 32 mrna ... | 1976 | 791948 |
| identification and study of species specificity of antiphage lipopolysaccharides found in the preparations of bacterial dna. | a method of isolation of the antiphage agent found in the preparations of bacterial dna was developed. chemical analysis of the preparations has shown that according to their qualitative and quantitative composition they are identical to the lipopolysaccharide of the bacterial membrane. on the basis of data on the antiphage activity of the d-lps from e. coli b and e. coli k12 and on the basis of presumed analogy between the inactivation of the phage by the d-lps preparations and the phage--cell ... | 1976 | 792328 |
| biochemical construction of specific chimeric plasmids from cole1 dna and unfractionated escherichia coli dna. | a series of chimeric plasmids was constructed using colicinigenic factor e1 (cole1) dna as the replicon and dna fragments carrying the galactose or tryptophan operons from e. coli. restriction endonuclease ecori digests of cole1 dna and various dnas containing the trp or gal operons were joined by t4 polynucleotide ligase [polynucleotide synthetase (atp), poly(deoxyribonucleotide):poly(deoxyribonucleotide) ligase (amp-forming), ec 6.5.1.1]. chimeric plasmids carrying the desired genes were selec ... | 1976 | 792875 |
| the sucrose gradient and native dna s20,w, an examination of measurement problems. | sedimentation coefficients of t7, t2h and t4 dna were determined with isokinetic sucrose gradients in both 0.1 m and 1 m nacl. the s values were completely equivalent to those measured by analytical ultracentrifuge and no reduction of s20,w was observed due to the presence of sucrose (anomalous sedimentation). s20,w values are calculated on the basis of both partial specific volume (v) and apparent specific volume (0). using the latter value s20,w molecular weight relations are derived for 0.1 m ... | 1976 | 793631 |
| enzymes involved in thymine dimer excision in bacteriophage t4-infected escherichia coli. | 1976 | 794491 | |
| [biology of spheroplast- and protoplast-like types of l-forms of escherichia coli k12 converted with penicillin]. | a total of 21 strains of stable l-forms were obtained under the action of penicillin on various hfr and f- strains of e. coli k12. three morphological types of the l-forms obtained differed by the character of the cell elements, sensitivity to chemical agents, antibiotics and to t4 and t6 phages. cell wall was revealed in one type of the l-forms, but the rest l-form types were devoid of the cell walls. reference of the l-forms which preserved the cell wall to the spheroplastic type, and the l-fo ... | 1976 | 795246 |
| the genome of bacteriophage t4. | 1976 | 795415 | |
| [reversion of rna-polymerase mutations affecting f'-factor stability]. | ts+ reversions of amber mutations tsr on the beta-subunit of escherichia coli rna polymerase (79 min on the genetic map) were investigated. tsr mutants are viable due to the partial suppression of amber mutations by su2 suppressor. three types of reversions were isolated in the course of the selection for ts+ character, namely, intragenic reversions and two types of extragenic reversions, located at different regions of the bacterial chromosome. the mutation n5, located between 0 and 15 min. on ... | 1976 | 795716 |
| [mutator effect of suppressed amber-alleles of early genes of bacteriophage t4]. | the mutator effect of amber alleles of three early genes (43, 32, 47), which were suppressed by the bacterial suppressor gene, was studied. there are some advantages in using the suppressed amber alleles instead of ts, because in this case definite amino acid substitutions take place in the protein due to certain suppressor gene effect. for example, in escherichia coli cr63(su+-1) the replacement of the original amino acid by serine takes place. studying the mutator effect of 43 alleles of dna p ... | 1976 | 795721 |
| [allele specificity of the mutator action of bacteriophage t4 genes 43 and 32]. | the substitution of tester mutant ri31 (fs-type) for transition mutants ruv30 and ruv48 allowed to reveal new mutator alleles of dna polymerase gene of phage t4. in these conditions about 70% alleles of this gene were found to be mutators. unlike experiments carried out with mutant-tester ri31, in experiments with mutants ruv30 and ruv48 the presence of mutator alleles in gene 32 was demonstrated. the transition pathway at leads to gc is the preferential direction of the mutation alteration unde ... | 1976 | 795722 |
| identification and study of species specificity of antiphage lipopolysaccharides found in the preparations of bacterial dna. | a method of isolation of the antiphage agent found in the preparations of bacterial dna was developed. chemical analysis of the preparations has shown that according to their qualitative and quantitative composition they are identical to the lipopolysaccharide of the bacterial membrane. on the basis of data on the antiphage activity of the d-lps from e. coli b and e. coli k12 and on the basis of presumed analogy between the inactivation of the phage by the d-lps preparations and the phage -- cel ... | 1976 | 796382 |
| [chemotypes of "shigella flexneri" r mutants and related phage receptors. ii. -- localization of phage receptors (author's transl)]. | receptor sites for phages fp3, v, p1kcvir, h+, c21, t4, t3, t7 and 6sr have been investigated, by comparing the lytic activity of these phages on r mutants of strain f6 (f6r) and of various serotypes (fh) of shigella flexneri with their inhibition by the lipopolysaccharides isolated from these mutants. the results suggest the following localizations for the receptor sites: phage fp3: lipid a-kdo; phage v: heptose or glucose; phage c21: heptose-glucose; phages h+, p1kcvir, t4 and t3: glucose; pha ... | 1976 | 798512 |
| revertants of double opal-mutants of bacteriophage t4. | revertants of double opal-mutants of bacteriophage t4 have been obtained. the properties of these revertants suggest that reversion of double opal-mutants is effected by the activity of some gent-suppressor appeared in the phage genome. restriction of these revertants by streptomycin-resistant bacterial strains shows that the suppression of the opal-mutants is realized at translation. | 1976 | 799254 |
| in vitro construction of bacteriophage lambda and plasmid dna molecules containing dna fragments from bacteriophage t4. | restriction endonucleases ecori and hindiii generated fragments of t4 cytosine-containing dna were inserted into bacteriophage vector lambdagtsuiii and plasmid vectors pmb9 and pbr313. resulting clones were screened for hybridization with 32p labeled t4 trna. recombinant bacteriophages and plasmids were isolated which contained a t4 fragment coding for t4 rna species 1 and 2 and t4 trna arg. selected lambda-t4 hybrid bacteriophages were grown to high titer and their dna analyzed by gel electroph ... | 1976 | 802392 |
| production and measurement of exophthalmos-producing factor in guinea pigs. | although the extent of proptosis in exophthalmic graves' disease has been measured directly and shown to correlate with serum content of a bioassayable exophthalmus-producing factor (eps;1), a comparable relationship in an experimental model has not been reported. progressive exophthalmos, measured from photographs and expressed as a ratio of intercorneal distance to intersupraorbital ridge distance, was produced in male guinea pigs when thyroid status was altered either by surgical thyroidectom ... | 1975 | 803260 |
| influence of thyrotropin-releasing hormone on the postmenopausal female. | daily blood samples were obtained from 5 postmenopausal patients for 21 days and analyzed for plasma follicle stimulating hormone (fsh), luteinizing hormone (lh), estrone, estradiol, progesterone, and serum t4. on days 8 through 14, oral thyrotropin-releasing hormone (trh) was administered, 50 mg, 4 times a day. all patients showed asignificant t4 response. there was, however, no significant change in the plasma fsh, lh, estrone, estradiol, or progesterone. we conclude that oral administration o ... | 1975 | 803307 |
| thyroid function and triiodothyronine and thyroxine kinetics in rabbits immunized with thyroid hormones. | neck-uptake studies, thyroid scintiscans and triiodothyronine (t4)-kinetic studies were performed in normal rabbits and in animals producing antibodies against thyroid hormones. in immunized animals the radioiodide uptake and turnover were increased 3-fold and 6-17-fold, respectively. the thyroid glands were found to be enlarged scintigraphically and showed a denser tracer distribution pattern. t3 and t4 kinetic data were obtained from 5 rabbits immunized with t3 (abt3), 4 immunized with t4 (abt ... | 1975 | 803750 |
| studies on gonococcus infection. vii. in vitro killing of gonococci by human leukocytes. | the comparative killing of pilated and nonpilated forms of neisseria gonorrhoeae by human peripheral blood leukocytes was studied in vitro. some nonpilated gonococci (t2) were killed to a lesser extent than were pilated, t2 organisms, which were killed less readily than another nonpilated (t4*) form of gonococcus. thus, the relative order of killing of gonococci by human peripheral blood leukocytes appears to be: t4 less than t2 less than t4*. these data suggest that pilation, though correlated ... | 1975 | 803924 |
| studies on gonococcus infection. viii. 125iodine labeling of gonococci and studies on their in vitro interactions with eukaryotic cells. | intact gonococci (gc) have been labeled with 125iodine by the lactoperoxidase plus hydrogen peroxide procedure. the specific activities of types 2, 4, and 4 gc have been determined and are found to show small differences as follows: t4 greater than t2 greater than t4. 125i-labeled gc have been studied for their associations with both leukocytes and tissue culture cells. 125i-labeled gcshow the following relative order of association with the leukocytes: t2 equals t4* greater than t4. this contra ... | 1975 | 803927 |
| modification of escherichia coli membranes in the prereplicative phase of phage t4 infection. specificity of association and quantitation of bound phage proteins. | reinfection of escherichia coli with the bacterial virus t4 causes modifications of the properties of the host cell envelope during the preeplicative phase of the lytic cycle. these changes include altered densities cell enveloped and their subfractions, morphological modifications of membrane vesicles, and association of newly synthesized proteins with the host cell envelope. polypeptide analysis by high resolution electrophoresis on polyacrylamide slab gels in dodecyl sulfate revealed that mos ... | 1975 | 803972 |
| augmentation of thyrotropin responses to thyrotropin-releasing hormone following small decreases in serum thyroid hormone concentrations. | to determine whether slight decreases in serum thyroid hormone concentrations resulted in augmentation of the thyrotropin (tsh) response to thyrotropin-releasing hormone (trh), tsh responses to trh were determined before and after 13 days of iodide treatment in 20 normal subjects. slight reductions in serum thyroxine (t4) and/or triiodothyronine (t3) concentrations and slight increases in basal serum tsh concentrations occurred in normal subjects treated with 50 or 250 mg iodide daily, though se ... | 1975 | 803974 |
| low serum triiodothyronine in patients with anorexia nervosa. | patients with anorexia nervosa can demonstrate clinical and/or laboratory findings suggestive of reduced thyroid hormone secretion. in this study, the thyroxine (t4) and triiodothyronine (t3) serum concentrations, and thyrotropin (tsh) response to intravenous administration of thyrotropin releasing hormone (trh) were determined in 6 patients (aged 9 to 15 yr) with anorexia nervosa and the results compared to those found in a group of 15 normal subjects. the mean basal tsh concentration and mean ... | 1975 | 803975 |
| circulating thyroid hormones and thyrotropin in adult patients with protein-calorie malnutrition. | we studied plasma concentrations of thyroxine (t4), triiodothyronine (t3), free t4, free t3, thyrotropin (tsh), albumin and thyroxine-binding globulin (tbg) before and following 56 to 145 days (mean, 85) of refeeding in ten indian patients who had severe protein-calorie malnutrition (pcm). the mean baseline plasma t4 concentration of 8.2 mug per 100 ml in these patients was comparable to the corresponding post-treatment value of 7.7 mug per 100 ml. however, since the dialyzable fraction of t4 (d ... | 1975 | 804140 |
| serum thyroid hormones and thyrotropin in anorexia nervosa. | sixteen patients with typical signs and symptoms of anorexia nervosa were studied with measurement of serum thyroxine (t4), triiodothyronine (t3) and thyrotropin (tsh), both baseline and stimulated by thyrotropin-releasing hormone (trh). the results of the patients were compared with those of 16 normal control subjects. serum t4 (5.8 plus or minus 0.26 mug/100 ml, mean plus or minus se) and t3 (82 plus or minus 5.7 ng/100 ml) of patients with anorexia nervosa were significantly (p less than 0.00 ... | 1975 | 804141 |
| thyrotropin-releasing hormone secretory physiology: studies by radioimmunoassay and affinity chromatography. | thyrotropin-releasing hormone (trh) in rat blood and mathanol extracts of hypothalami has been quantified by a specific trh radioimmunoassay, in conjunction with trh affinity chromatography. blood trh was found to be elevated dramatically after 1 h by the physiologic stimulus, ambient cold (4 c), which was also attended by a 2-fold rise in serum thyrotropin (tsh). the acute administration of parenteral triodothyronine (t3) over a period of 48 h prior to identical cold exposure completely abolish ... | 1975 | 805042 |
| familial thyroxine-binding globulin deficiency in a patient with congenital hypothyroidism. | a kindred with deficiency of thyroxine binding globulin (tbg) was presented. the propositus, a 1-year old female also had congenital hypothyroidism with ectopic (sublingual) thyroid. decrease in tbg-binding capacity (tbg) values ranging from 1.2-10.2 mug/100 ml) was detected in the seven relatives on the maternal side. of these subject 2 were male and 5 female; the males had the lowest binding capacities. but six members of paternal relatives were entirely normal in this respect. the mode of inh ... | 1975 | 805043 |
| propylthiouracil blocks extrathyroidal conversion of thyroxine to triiodothyronine and augments thyrotropin secretion in man. | propylthiouracil (ptu) inhibits peripheral deiodination of thyroxine (t4) and triiodothyronine (t3) and decreases the metabolic effectiveness of t4 in animals. to assess the effect of ptu on extrathyroidal conversion of t4 to t3 in man, 15 studies were performed in athyreotic patients treated with 100 or 200 mug of l-t4 daily for 1 mo before the addition of ptu, 250 mg every 6 h for 8 days. serum t3, t4, and thyrotropin (tsh) were measured daily by radioimmunoassay; serum tsh response to 500-mu ... | 1975 | 805160 |
| excessive thyrotropin concentrations in the circulation of the spontaneously hypertensive rat. | thyroid funct-on in shr was compared to that of inbred normotensive wistar rats from kyoto, and random bred wistar rats from the united states. a marked increase in circulating thyrotropin concentration was found in shr compared to controls. serum thyroxine and t3 concentrations relative to controls, however, were variable and the concentrations in male and female shr relative to kyoto controls did not correspond with each other. no ready explanation for the circulating excess of thyrotropin, w ... | 1975 | 805436 |
| dorsal root afferents to clarke's column from hindlimb cord levels in tupaia and galago. | the projection of hindlimb dorsal root afferents to clarke's column has been studied in the tree shrew (tupaia glis) and lesser bushbaby (galago senegalensis). in the bushbaby, fibers from k12, l1 and l3 projected ipsilaterally to clark's nucleus from levels l3 to t3, l2 to t4 and l3 to t5 respectively. in tupaia, afferents from t11, l1, and l3 terminated ipsilaterally within the nucleus from segments l2 to t4, l3 to t6, and l3 to t8. fibers from t12, l1, and l3 in galago and t11 in tupaia termi ... | 1975 | 805631 |
| the trh test in the course of treatment of hyperthyroidism. | in nine patients with thyrotoxicosis (three patients with ophthalmopathy, one patient with t3 thyrotoxicosis) we followed plasma levels of triiodothyronine (t3) and thyroxine (t4) and the trh induced tsh release before and under treatment with propythiouracil (ptu), carbimazole or methimazol. the patients were observed for 2-8 months and did not receive any thyroid hormones during this time. before treatment the tsh responses to trh were absent in all patients. after commencement of antithyroid ... | 1975 | 805680 |
| variations of rat thyroid activity during exposure to high environmental temperature (34 degrees c). relation between hypothalamic pituitary and thyroid hormone levels. | changes in thyroid activity and variations in the hypthalamo-pituitary-thyroid hormone levels were examined in rats exposed to heat (34 degrees c)for3 weeks. thyroid activity evaluated histologically (epithelium/colloid ratio, nuclear size) by radioiodine exploration (24 hrs 125 i uptake, ratio of mono- to di-125 iodotyrosines - mit/dit, ratio of tri- to tetra-125 iodothyronines-t3/t4, and plasma 125i-t4 and assay of plasma t4, evolves in a triphasic manner. 1.a depression phase between day 0 a ... | 1975 | 806054 |
| [when is a radioisotope diagnosis indicated in thyroid diseases and when is it superfluous?]. | in response to the question when radioactive isotopes (radionuclides) are necessary or superfluous in the diagnostic workup of thyroid disease, the following observations can be made: 1. radionuclides are almost ubiquitously used for the specific and relevant in-vitro tests for measuring the circulating thyroid hormones (t4 und t3, etc.) and necessitate a very small quantity of serum. they lead in approximately 90% of cases of the correct diagnosis, especially when supported by careful clinical ... | 1975 | 806113 |
| [treatment possibilities of laryngeal cancer. surgery--radiotherapy--chemotherapy]. | treatment's possibilities of the carcinoma of larynx are presented and we especially attract notice to require a right distribution of stages in conformity with the prescriptions from the u.i.c.c. operation's methods and radiotherapeutic possibilities are indicated. following the author's views, it would be made primary irradiations in the stages t1 and t2, while only after the operation it would be necessary to use a radiotherapy in the stages t3 and t4. the possibility of a preoperative irradi ... | 1975 | 806145 |
| motility of bacillus subtilis during growth and sporulation. | the change of motility and the presence of flagella were followed throughout growth and sporulation in a standard sporulating strain and in 19 cacogenic sporulation mutants of bacillus subtilis. for the standard strain, the fraction of motile cells decreased during the developmental period to less than 10% at t4. motility was lost well before the cells lose their flagella. conditions reducing the decrease of motility also reduced sporulation: motile cells never contained spores. the decrease of ... | 1975 | 806579 |