Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| extrapituitary regulation of the circadian rhythm of plasma corticosteroid concentration in rats. | intravascular injections of adrenocorticotropic hormone in hypophysectomized rats were approximately 3 times more effective in stimulating increases in plasma corticosteroid concentration when given at the offset rather than the onset of the daily photoperiod (12 h:12 h light-dark cycle). reversal of the photoperiodic schedule produced a reversal in the corticosteroid response after 5 days. similar temporal variations in androgen and t4 responses to lh and tsh were not obtained. although plasma ... | 1978 | 218790 |
| mitochondrial binding sites for triiodothyronine. | metabolic effects upon rat liver mitochondria have been observed by others within 2 min of injection of massive amounts of l-t4. reported here is the subcellular distribution of 2--5 ng high specific activity [125i]l-t3 2 min after ip injection with and without a loading dose of 30 micrograms unlabeled t3. the loading dose did not change the hormone concentration in the livers of normal or thyroidectomized rats, but it decreased the amount of hormone found in the nuclei in both groups and it inc ... | 1978 | 218792 |
| decreased hepatic nuclear l-triiodothyronine receptors in rats and mice bearing transplantable neoplasms. | the concentration of hepatic nuclear t3 receptors was measured in isolated nuclei from athyreotic mice bearing thyrotrophic tumors and intact rats with walker 256 carcinoma. receptor concentration was reduced in all tumor-bearing animals. the mean receptor capacity of the walker tumor-bearing rats [0.31 +/- 0.05 (sem) ng/mg dna] was significantly decreased from simultaneously assayed controls (0.47 +/- 0.04 ng/mg dna; p less than 0.01). no change in the apparent equilibrium association constant ... | 1978 | 218807 |
| a dna-unwinding enzyme induced in bacteriophage-t4-infected escherichia coli cells. | a single-stranded dna-dependent atp gamma-phosphohydrolase of mr 56000 induced after infection of escherichia coli cells with bacteriophage t4, probably the atpase dependent on gene dda of the phage, was isolated. studies on the enzyme show that in the presence of atp and m2+ ions it is capable of dissociating partially double-stranded fd bacteriophage dna into the single strands and that some 3000 enzyme copies are required to unwind the 6400-nucleotides-long dna. unwinding is inhibited by redu ... | 1979 | 218815 |
| the purification of nuclease-free t4-rna ligase. | rna ligase has been highly purified in good yields from bacteriophage t4-infected escherichia coli by a rapid and reproducible procedure. the enzyme is free of phosphomonoesterase and ribonuclease activities and is therefore suitable for the synthesis of oligoribonucleotides and for the labeling of the 3'-terminus of rna. greater than 90% of the protein in the enzyme preparation migrates as a single band on gradient polyacrylamide gels containing sodium dodecyl sulfate during electrophoresis. fo ... | 1979 | 219895 |
| subcellular localization of thyroxine and reverse triiodothyronine outer ring monodeiodinating activities. | in order to examine the subcellular localization of outer ring t4- and rt3-monodeiodinating activities, nuclear, mitochondrial, microsomal, cytosol, and plasma membrane fractions of rat liver homogenate were incubated with either t4 or rt3 in phosphate buffer (ph 7.35) in the presence of 2 mm dithiothreitol for 15 min at 37 c, and the amount of product (t3 in the case of t4 and 3,3'-diiodothyronine in the case of rt3) was measured by specific ria. the various tissue fractions were also examined ... | 1979 | 221175 |
| effects of hypophysectomy, thyroidectomy, and thyroxine on specific prolactin receptor sites in kidneys and adrenals of male rats. | the effect of t4 on specific prl binding in the kidneys and adrenals was measured in intact, hypophysectomized, and thyroidectomized male rats. prl binding in the kidneys was reduced from 12.1 +/- 1.1% in the intact group to 4.5 +/- 0.5% after hypophysectomy; 4-day replacement with t4 returned prl binding to intact values. t4 administered to intact rats significantly increased prl binding above intact values. thyroidectomy reduced prl binding in the kidneys from 14.9 +/- 1.2% to 7.0 +/- 0.6%, an ... | 1979 | 221176 |
| dna binding properties of the t4 dna helix-destabilizing protein. a calorimetric study. | 1979 | 221498 | |
| t4 gene 32 protein trypsin-generated fragments. fluorescence measurement of dna-binding parameters. | the intrinsic fluorescence of the t4 helix-destabilizing protein specified by gene 32 (32p) is not altered by the proteolytic removal of either the 6200-dalton cooh-terminal "a" region (32p*-a) or both the a and the 2300-dalton nh2-terminal "b" region (32p*-(a + b)). the intrinsic fluorescence of 32p, 32p*-a, and 32p*-(a + b) is decreased 23% by the addition of d(pt)8 and 34% by the addition of poly(dt). saturation binding curves of the percentage of change in protein fluorescence as a function ... | 1979 | 221499 |
| relationship of receptor affinity to the modulation of thyroid hormone nuclear receptor levels and growth hormone synthesis by l-triiodothyronine and iodothyronine analogues in cultured gh1 cells. | we have previously demonstrated that l-triiodothyronine (l-t3) induces an increase in growth hormone synthesis and messenger rna in cultured gh1 cells, a rat pituitary cell line. in addition to regulating the growth hormone response, l-t3 elicits a time- and dose-dependent reduction in the level of its nuclear receptor, which is a direct function of the occupancy of the receptor binding site. in this study we have compared the relative affinity of l-t3, triiodothyroacetic acid, d-triiodothyronin ... | 1979 | 221536 |
| endocrine response after burn. | the use of radioimmunoassays has made new advances in post-burn endocrine studies possible. the mean fasting iri plasma (pl.) levels were elevated for 7 weeks, sometimes reaching very high values. during ogtt, an impaired glucose tolerance and insulin resistance could be found. pl. hgh levels were normal or slightly increased, and their hypoglycemia-caused rise in the first two postburn weeks was blocked. renin and angiotensin ii pl. levels were high or very high in almost all burned patients. t ... | 1979 | 221969 |
| removal of t4 endonuclease v-sensitive sites from sv40 dna after exposure to ultraviolet light. | the induction and removal of sites sensitive to t4 endonuclease v from ultraviolet-irradiated simian virus 40 (sv40) form i (supercoiled) dna during a lytic infection of monkey cv-1 cells was investigated by agarose tube gel electrophoresis. endonuclease-sensitive sites were induced at a rate of 0.049 sites/sv40 genome per j/m2, or 1.4 sites/1 . 10(8) daltons of dna per j/m2. this value is similar to the yield of endonuclease-sensitive sites and pyrimidine dimers in uninfected host cv-1 cell dna ... | 1979 | 222324 |
| effects of thyrotoxicosis on mitochondrial enzymes of rat soleus. | cytochrome oxidase, glycerol-3-phosphate dehydrogenase, and succinate dehydrogenase were measured in mitochondrial fractions obtained from rat soleus muscle of control and 8 week t3 + t4 treated animals. under these conditions of prolonged treatment, there is a five-fold increase in the specific activities of both cytochrome oxidase and glycerole-3-phosphate dehydrogenase. significant increases in total cellular mitochondrial content and enzyme activities were observed in t3 + t4 treated animals ... | 1979 | 222661 |
| neisseria gonorrhoeae membrane microenvironment studied by spin-label electron spin resonance: comparison of colony types. | spin-label electron spin resonance was used to characterize the microenvironment around spin probes which localize (i) in membranes, (ii) at the membrane surface, or (iii) in the cytoplasm of living neisseria gonorrhoeae. four colony types (t1, t2, t3, and t4) of gonococci were compared on the basis of the electron spin resonance parameters 2t parallel to, s (order parameter), and tau c (microviscosity). the concentration of spin label used had little or no effect on viability. t1 and t2 gonococ ... | 1979 | 222734 |
| receptor affinity and biological potency of thyroid hormones in thyrotropic cells. | the nuclear receptor affinity for l-triiodothyronine (l-t3), l-thyroxine (l-t4), l-triiodothyroacetic acid (triac), and d-triiodothyronine (d-t3) was compared to the potency of these thyroid hormone analogues in regulating thyrotropin (tsh) production and the number of membrane receptors for thyrotropin-releasing hormone (trh) in mouse thyrotropic tumor cells in culture. l-t3 and triac were equally potent and d-t3 was one-sixth to one-fifth as potent in binding to the receptor and in regulating ... | 1979 | 223453 |
| biphasic inhibitory and stimulatory effects of thyrotropin on the mitotic activity of thyroid explants cultured in vitro. | an influence of thyrotropin (tsh), dibutyryl cyclic amp (dbcamp), triiodothyronine (t3) and thyroxine (t4) on the mitotic incidence in the organ-cultured rat thyroid was studied. the study has revealed biphasic inhibitory and stimulatory effects of tsh on the thyroid mitotic activity. the inhibitory effect occurred 14 h after an exposure of the thyroid explants to tsh and was enhanced by t3. a similar inhibitory effect was observed after an exposure of the explants to dbcamp. 24 h after the expo ... | 1979 | 223838 |
| probing dna replication mechanisms with the t4 bacteriophage in vitro system. | 1979 | 225114 | |
| cyclic 3',5'-adenosine monophosphate (camp) in a 42-month-old child with clinical evidence of multiple hormonal disturbances. | in a boy aged 42 months, small stature, retarded psychomotor development, dry skin, excessive thirst, polyuria, cryptorchidism, and rickets were signs of multihormonal disturbances. contrary to the clinical manifestations, laboratory investigations showed normal or raised levels of hormones (hgh, insulin, t3ru, t4, tsh, pth). the camp level in the plasma was low and its urinary excretion was reduced. after administration of hgh, adrenaline, t3, t4, pitressin, vitamin d3 and aminophylline there w ... | 1979 | 225175 |
| the effects of growth hormone, thyroxine and insulin on the activities of reduced nicotinamide adenine dinucleotide phosphate dehydrogenase, glucose-6-phosphatase and glycogen phosphorylase in fetal rat liver. | growth hormone (gh), thyroxine (t4) and insulin were injected, in utero into 20.5 day-old rat fetuses to study the effects of these hormones on the activities of liver nadph dehydrogenase, glucose-6-phosphatase and glycogen phosphorylase. it was found that at 21.5 days of gestation, gh increases the fetal liver glucose-6-phosphatase activity and decreases the liver glycogen phosphorylase activity. t4 treatment augments the activity of nadph dehydrogenase even at 0.3% of the dose shown previously ... | 1979 | 225253 |
| size of infectious dna from human and murine cytomegaloviruses. | viral dna was isolated from human and murine cytomegalovirus by equilibrium centrifugation in cesium chloride gradients. the size of the dna was measured relative to t4 dna by velocity sedimentation in neutral glycerol gradients, and fractions were assayed for infectious dna. infectious murine cytomegalovirus dna sedimented as a single peak with an estimated molecular weight of 136 x 10(6). infectious human cytomegalovirus dna was detected in two peaks with molecular weights of 130 x 10(6) and 1 ... | 1979 | 225527 |
| involvement of eucaryotic deoxyribonucleic acid polymerases alpha and gamma in the replication of cellular and viral deoxyribonucleic acid. | in an effort to identify the deoxyribonucleic acid (dna) polymerase activities responsible for mammalian viral and cellular dna replication, the effect of dna synthesis inhibitors on isolated dna polymerases was compared with their effects on viral and cellular dna replication in vitro. dna polymerase alpha, simian virus 40 (sv40) dna replication in nuclear extracts, and cv-1 cell (the host for sv40) dna replication in isolated nuclei all responded to dna synthesis inhibitors in a quantitatively ... | 1979 | 226127 |
| plasma free tryptophan, brain serotonin, and an endocrine profile of the genetically obese hyperglycemic mouse at 4--5 months of age. | genetically obese hyperglycemic mice (ob/ob) were compared with their nonlittermate lean controls at 4-5 months of age with regard to brain serotonin, pituitary acth content, and circulating levels of glucose, glucagon, insulin, tsh, t3, t4, total tryptophan and free tryptophan. brain serotonin pituitary acth content, and plasma insulin, glucose, total tryptophan, and free tryptophan were all significantly higher in obese mice than in the controls. tsh, t3, and t4 were not significantly differen ... | 1979 | 226347 |
| [the characterization of nuclear triiodo-l-thyronine receptors of rabbit liver (author's transl)]. | the binding characteristics and physical properties of the nuclear receptors of rabbit liver were studied. the receptors were extracted with 0.4m kcl from purified hepatic nuclei and were incubated with increasing doses of 125i-triiodo-l-thyronine (l-t3) and stable l-t3 for 2 hours at 20 degrees c. scatchard analyses indicated that the association constant (ka) of the nuclear receptors was 1.5 x 10(10)m-1, and that maximal binding capacity was about 0.12 pmol t3 per 1 ml of nuclear extract, equi ... | 1979 | 226424 |
| early effects of thyroidectomy and triiodothyronine administration on rat-liver mitochondria. | this work was undertaken to study the action exerted by thyroid hormones on mitochondria. by day 6 after thyroidectomy, the respective activities of two inner-membrane enzymes--succinate and beta-hydroxybutyrate cytochrome c reductases--had already dropped by 32 and 50%, whereas, in the outer membrane, the activity of rotenone-insensitive nadh-cytochrome c reductase did not change significantly. the decrease in the activity of the inner-membrane enzymes closely followed the disappearance of t3 a ... | 1979 | 226438 |
| purification of the t4 gene 32 protein free from detectable deoxyribonuclease activities. | detailed procedures are presented which allow reproducible preparation of t4 gene 32 protein, a helix-destabilizing protein essential for dna replication and genetic recombination in t4 bacteriophage-infected escherichia coli cells. although 32 protein can be purified to better than 99% homogeneity by any one of several procedures, these methods have been developed to remove trace amounts of contaminating deoxyribonucleases, which are present in high levels in the original infected cells. two al ... | 1979 | 226522 |
| plasma high density lipoprotein cholesterol in thyroid disease. | the plasma levels of high density lipoprotein cholesterol (hdl-c) were reduced in 16 hyperthyroid female patients compared to 37 euthyroid women (33.5 +/- 8 vs. 51.5 +/- 13 mg/dl (mean +/- sd); p less than 0.001). when 5 patients were restudied after restoration of the euthyroid state, plasma hdl-c increased from 29 +/- 5 to 43 +/- 11.5 mg/dl (p less than 0.05). in addition, in 22 hypothyroid women, hdl-c levels were also diminished compared to the euthyroid group (43.4 +/- 15.5 vs. 51.5 +/- 13 ... | 1979 | 226559 |
| t4 dna topoisomerase: a new atp-dependent enzyme essential for initiation of t4 bacteriophage dna replication. | a novel atp-dependent dna topoisomerase which makes reversible double-strand breaks in the dna double helix has been purified to near homogeneity from t4 bacteriophage-infected escherichia coli cells. genetic data suggest that this activity is essential for initiating t4 dna replication forks in vivo. | 1979 | 226889 |
| synthesis and enzymatic properties of deoxyribooligonucleotides containing methyl and phenylphosphonate linkages. | chemical methods for the synthesis of short deoxyribooligonucleotides containing methyl and phenylphosphonodiester linkages have been developed. the interaction of two such nonionic dinucleotide analogs, t(pch3)t and t(pc6h5)t, with several enzymes has been investigated. because of the phosphonate linkage each dinucleotide exists as a diastereomeric pair as shown by thin layer chromatography and enzymatic studies. both isomers of each dinucleotide can be phosphorylated by t4-polynucleotide kinas ... | 1979 | 226943 |
| t4 dna-delay proteins, required for specific dna replication, form a complex that has atp-dependent dna topoisomerase activity. | under some conditions, t4 dna replication requires the products of the dna-delay genes, genes 39, 52, 58, and 60. by using an in vitro complementation assay that stimulates dna replication in t4 39(-)-infected cell extracts, t4 gene 39 protein has been purified. the purified fraction also contains complementing activities for t4 genes 52 and 60. on sodium dodecyl sulfate/polyacrylamide gel analysis the purified preparation exhibits three protein components: a 51,000-dalton protein corresponding ... | 1979 | 226976 |
| imparied cyclic-amp response to thyrotrophin in congenital hypothyroidism with thyroglobulin deficiency. | a 19 year old man had congenital hypothyroidism and severely retarded development. his thyroid gland was not enlarged and laboratory findings included low serum concentration of t4 (2.8 microgram/100 ml) and t3 (16 ng/100 ml) with a high level of tsh (52 microu/ml) that rose to 192 microu/ml after trh. 131i uptake by the thyroid was normal (41.5% at 24 h) and did not show a normal increase after exogenous tsh administration (49.5% at 24 h). the perchlorate discharge test was negative and no anti ... | 1979 | 227208 |
| a new gene of escherichia coli k-12 whose product participates in t4 bacteriophage late gene expression: interaction of lit with the t4-induced polynucleotide 5'-kinase 3'-phosphatase. | we isolated five escherichia coli mutants deficient in their ability to support the late (replication-coupled) gene expression of t4 bacteriophage at 30 degrees c. these mutants, which we call lit mutants, define at least one novel gene at 25 min on the e. coli map. they were selected in an attempt to obtain mutants which restrict the growth of t4 mutants deficient in polynucleotide 5'-kinase 3'-phosphatase but not that of wild-type t4 at 37 degrees c. some of the mutants do have these phenotype ... | 1979 | 227837 |
| escherichia coli mutants thermosensitive for deoxyribonucleic acid gyrase subunit a: effects on deoxyribonucleic acid replication, transcription, and bacteriophage growth. | temperature-sensitive nala mutants of escherichia coli have been used to investigate the structure and functions of deoxyribonucleic acid (dna) gyrase. extracts of one such mutant (nala43) had thermosensitive dna gyrase subunit a activity but normal gyrase subunit b activity, proving definitively that nala is the structural gene for subunit a. extracts of a second nala (ts) mutant (nala45) had a 50-fold deficiency of gyrase subunit a activity. the residual dna supertwisting was catalyzed by the ... | 1979 | 227840 |
| metabolism of okazaki fragments during simian virus 40 dna replication. | essentially all of the okazaki fragments on replicating simian virus 40 (sv40)dna could be grouped into one of three classes. class i okazaki fragments (about 20%) were separated from longer nascent dna chains by a single phosphodiester bond interruption (nick) and were quantitatively identified by treating purified replicating dna with escherichia coli dna ligase and then measuring the fraction of okazaki fragments joined to longer nascent dna chains. similarly, class ii okazaki fragments (abou ... | 1979 | 227871 |
| a new system for studying molecular mechanisms of mutation by carcinogens. | a new system for studying the molecular mechanisms of mutation by carcinogens is described. the system involves (a) site-specific modification of the essential gene g in phi x174 replicative form dna by a combination of chemical and enzymatic steps; (b) production of mutant virus carrying a change at a single preselected site by transfection of spheroplasts with the site modified phi x174 dna; (c) detection and propagation of mutants using a host carrying the plasmid, p phi xg, that rescues all ... | 1979 | 227905 |
| preferential in vitro assembly of nucleosome cores on some at-rich regions of sv40 dna. | we have found that nucleosomes reconstituted from histone octamers and sv40 dna form i by progressively decreasing the salt concentration from 2 m nacl are formed preferentially around 0.27, 0.37, 0.50 and 0.85 on sv40 dna (relative to the ecori site). when sv40 dna form iii is used, the nucleosomes form mainly at 0.28, 0.38, 0.61 and 0.83. these sites are very close to both the sites of rna chain initiation by calf thymus rna polymerase b on sv40 dna form i (0.25, 0.35, 0.42 and 0.88) and the r ... | 1979 | 228248 |
| effects of thyroid hormones on liver binding sites for human growth hormone, as studied in the rat. | several weeks after thyroidectomy (t), female rats stopped growing, and their pituitary gh content had decreased to less than 2--3% of the values found for age-matched controls (c). the liver membranes of such animals were explored with human gh (hgh). it was found that in the severely hypothyroid t rat, the number, but not the affinity, of the lactogenic binding sites was markedly reduced. treatment of these rats for 3 weeks with 1.75 micrograms or t4 or 0.5 micrograms t3/100 g body weight/day ... | 1979 | 228880 |
| [studies on the radioreceptor assay of tsh: the binding of 125i-tsh to the human thyroid receptor and the interaction of lats-igg (author's transl)]. | the radioreceptor assay system for tsh is considered to be useful in quantitating the hormone and analyzing the mechanism of its action. the assay was established, and the interaction of abnormal thyroid stimulators in graves' patients was evaluated in this assay system. a 10,000xg fraction of human thyroid homogenates was used as the receptor. human tsh supplied from nih was iodinated by using lactoperoxidase. the binding of 125i-tsh to the receptor was small, and 125i-tsh was further purified ... | 1979 | 228997 |
| [studies on the radioreceptor assay of tsh: the properties of tsh-binding inhibitor immunoglobulins (tbii) in patients with graves' disease (author's transl)]. | in the radioreceptor assay system for tsh, serum immunoglobulin g (igg) from some patients with graves' disease has been shown to inhibit the binding of labelled tsh to its receptor sites. in order to clarify the properties of these tsh-binding inhibitor immunoglobulins (tbii) in patients with graves' disease, tbii were measured in sera from 31 untreated and 51 131i-treated patients, and their relation to clinical and laboratory findings was studied. tbii were detected in 18 (60%) out of 31 pati ... | 1979 | 228998 |
| effects of surgical stress and corticotrophin on the peripheral metabolism of thyroid hormones in rabbits. | the effect of surgical stress and acth injection on the peripheral monodeiodination of thyroxine (t4) was studied in the rabbit. these stimuli resulted in a switch from the peripheral formation of tri-iodothyronine (t3) to reverse t3 in normal rabbits and in rabbits whose thyroidal secretion was suppressed by administration of t4. this is analogous to the situation in man. these changes were not due to alterations in the serum binding capacity for thyroid hormones. | 1979 | 229182 |
| determination of the length distribution of poly(a) at the 3' terminus of the virion rnas of emc virus, poliovirus, rhinovirus, rav-61 and cpmv and of mouse globin mrna. | rapid, detailed, and accurate analysis of the length spectrum of 3' terminal poly(a) in an rna population can be obtained by 3'-terminal 32p-labelling of rna with t4 rna ligase, digestion with ribonucleases t1 and a, and use of gel sequencing methods. length distributions of 3'-terminal poly(a) of emc virus, poliovirus, rhinovirus, rav-61, and cpmv virion rnas as well as mouse globin mrna are presented. | 1979 | 229465 |
| control of the hypothalamus-pituitary-adrenal axis in young and older rats injected with thyroxine. | administration of t4 on alternate weeks for 30 weeks at a dosage which does not alter body weight depresses basal serum corticosterone levels in older rats (575 days), but not in young animals (260 days). similar serum corticosterone response to hpa axis stimulation occurs regardless of age or t4 injection. | 1979 | 230073 |
| effects of thyroxine treatment on the hepatic plasma membrane atpase activity in rats. | the effects of t4 and t3 upon atpase activity of plasma membrane preparations produced by different methods has been studied. media without na+ or k+ was used to identify mg++ activated atpase, and media containing 100-120 mm na+ and 20-30 mm k+ in addition to mg++ was used to identify the augmented activity of na-k atpase. we also utilized media containing na+, k+, and mg++ in the presence and absence of ouabain to identify the na+-k+ activation. we found no effect of doses of thyroxine in the ... | 1979 | 231081 |
| relationship between plasma prolactin concentration and pituitary function in patients with a pituitary adenoma. | the influence of hyperprolactinaemia on endocrine functions in forty-two consecutive patients with untreated pituitary tumours was studied. patients with acromegaly, cushing's disease and nelson's syndrome were excluded. sixteen patients (eleven men and five women) had a pituitary adenoma with suprasellar extension and twenty-six (eleven men and fifteen women) had a small intrasellar tumour. basal plasma prolactin concentration was measured in all. thyroid function was assessed by plasma thyroxi ... | 1979 | 231491 |
| the bam h1 restriction site in the bacteriophage t4 chromosome is located in or near gene 8. | bacteriophage t4 cytosine-containing dna is cleaved at a single site by the restriction endonuclease, bam h1. the site lies within the late region of the t4 genome, close to, or within, gene 8, one of the structural genes of the phage particle baseplate. | 1979 | 231540 |
| electron microscopic mapping of rna transcribed from the late region of polyoma virus dna. | the polyoma virus (py) rna species transcribed from the l dna strand of the "late" region of the py genome in py-infected mouse cells have been mapped by hybridization with specific fragments of py dna followed by electron microscopic visualization of the hybrids. total cellular polyadenylated py-specific rna molecules having an s value in the range of 16s to 20s were purified by oligodeoxythymidylic acidcellulose column chromatography, preparative hybridization with py dna, and sucrose gradient ... | 1979 | 232179 |
| secondary structures in polyoma dna. | three reproducible secondary-structure features were observed on single strands of polyoma virus dna mounted for electron microscopy by the t4 gene 32 protein technique: (i) a hairpin fold-back extending from 92.9 +/- 0.8 to 95.0 +/- 0.7 map units; (ii) a small loop extending from 63.2 +/- 3.1 to 68.5 +/- 2.8 map units; and (iii) a big loop extending from 51.9 +/- 2.3 to 68.9 +/- 2.1 map units. both loops are bounded by inverted repeat stems of length 40 +/- 20 base pairs. the stem sequences aro ... | 1979 | 232183 |
| combined test of hypothalamic-pituitary function in growth-retarded children treated with growth hormone. ii. secretion of lh, fsh, tsh, prolactin and acth. | a total number of 23 patients treated with human growth hormone were retested by use of a combined pituitary stimulation test. plasma concentrations of gh, fsh, lh, tsh, t4, t3, prolactin (prl), acth and cortisol were measured before and after stimulation with hypoglycemia, trh and lhrh. the test was performed in patients with persistent gh deficiency (group a) and patients with transitory gh deficiency (group b). in group a a normal pubertal development was found in three patients, whereas in p ... | 1979 | 232353 |
| [thyroid hormone action at cellular level: role of tiroxine (t4) and triiodothyronine (t3) on the maintenance of thyroid status (author's transl)]. | 1979 | 233042 | |
| effect of acth-stimulated glucocorticoid hypersecretion on the serum concentrations of thyroxine-binding globulin, thyroxine, triiodothyronine, reverse triiodothyronine and on the tsh-response to trh. | the responses of serum concentrations of tsh, thyroxine (t4), triiodothyronine (t3) and of reverse triiodothyronine (rt3) to i. v. administration of 0.4 mg thr were examined prior to (and after) i. m. administration of acth (2 mg synacthen depot) in 7 euthyroid women using estrogen-containing oral contraceptives and in 8 controls, with the following results: (1) an increase in endogenous glucocorticoid secretion is associated with a depression of the tsh response to trh; (2) tsh formed in decrea ... | 1979 | 233400 |
| an increase of plasma triiodothyronine and thyroxine after administration of dexamethasone to hypothyroid patients with hashimoto's thyroiditis. | in an attempt to study the effect of adrenal steroids on plasma thyroid hormone concentration in patients with hashimoto's thyroiditis, 2 mg dexamethasone was administered for 2-4 weeks to 9 patients with normal plasma tsh, 3 patients with compensatory increase of plasma tsh, and 10 patients with a marked elevation of plasma tsh. dexamethasone depressed plasma t4, t3, and tsh and reduced thyroid size in nine euthyroid patients, whereas a similar treatment did not affect plasma t3 and t4, but red ... | 1978 | 233634 |
| relationship between thyroid status and graves' disease-specific immunoglobulins. | the prevalence of tsi in graves' disease was investigated with a radioligand receptor assay using human thyroid membranes and highly purified labeled porcine tsh or bovine tsh in 110 patients before treatment and in 39 patients after successful treatment with antithyroid drugs. in 11 patients, the assay was performed before, during, and after therapy. the results in the radioligand receptor assay were compared to thyroid function tests (trh test, free t4 index, serum %3 level, and thyroid suppre ... | 1978 | 233668 |
| cultured thyroid cell adenosine 3',5'-cyclic monophosphate response to thyrotropin: loss and restoration of sensitivity to iodide inhibition. | unlike in all other thyroid preparations, exposure of dog thyroid cells in long-term monolayer culture to iodide (10(-7) to 10(-3) m for up to 19 h did not blunt the subsequent adenosine 3', 5'-cyclic monophosphate (camp) response to thyrotropin (tsh) stimulation. this lack of effect of iodide was observed even when confluent thyroid cells were "follicularized" by the action of tsh in the culture medium. preincubation of these cells in thyroxine (t4) and triiodothyronine (t3) was similarly witho ... | 1977 | 233822 |
| cyclic nucleotide phosphodiesterase from bone: characterization of the enzyme and studies of inhibition by thyroid hormones. | studies were carried out to characterize the cyclic nucleotide phosphodiesterase from rat calvaria. 25-40% of the total enzyme activity was membrane-bound. ph, magnesium, and temperature requirements conformed closely to those established for phosphodiesterase from other tissues. kinetic evidence was found for dual enzyme activities with different substrate affinities for both the particulate and soluble enzyme. apparent kms for the soluble enzyme (3.5 times 10-6 and 2.5 times 10-5m) approximate ... | 1975 | 234382 |
| kinetics and specificity of t4 polynucleotide kinase. | the kinetics of t4 polynucleotide kinase has been investigated at ph 8.0 and 37 degrees. double reciprocal plots of initial rates vs. substrate concentrations as well as product inhibition studies have indicated that the enzyme reacts according to the ordered sequential mechanism shown in eq 2 in the text for phosphorylation of a dna molecule. based on this mechanism the rate equation for the overall reaction was deduced and the various kinetic constants estimated. hill plots indicated little or ... | 1975 | 235284 |
| triiodothyronine binding to liver nuclear solubilized proteins in vitro. | nuclear proteins extracted from purified nuclei with 0.4m kcl at ph 7.4 or 8.5 are able to bind l-triiodothyronine (t3) giving rise to nuclear thyroid hormone binding protein-t3 (ntbp-t3) complexes. binding is maximum in 3 h at 20 c. it is thermolabile even at 36 c, inhibited by p-hydroxymercuribenzoate and markedly enhanced by dithiothreitol. optimum ph is between 7.8 and 8.5. divalent cations are not necessary. the ntbp-t3 complex exhibits similar anodal electrophoretic migration in polyacryla ... | 1975 | 235420 |
| thioredoxin reductase-mediated hydrogen transfer from escherichia coli thioredoxin-(sh)2 to phage t4 thioredoxin-s2. | thioredoxin from escherichia coli b and phage t4-infected e. coli b are small hydrogen carrier proteins which in their reduced forms are specific hydrogen donors to e. coli and t4-induced ribonucleotide reductase, respectively. the oxidation-reduction active group of both thioredoxins consists of a single cystine residue which is reduced to sulfhydryl form by nadph in the presence of e. coli thioredoxin reductase. reduction of t4 thioredoxin-s2 to thioredoxin-(sh)2 led to a 3-fold increase in th ... | 1975 | 235528 |
| phage t4 lysozyme. physical properties and reversible unfolding. | phage t4 lysozyme has been used extensively in studies of the genetic code. however, little work has been done on the characterization of the purified enzyme. therefore, we determined the spectral properties of native t4 lysozyme and used these properties to follow the unfolding transition. the ultraviolet absorption spectrum and solvent perturbation difference spectrum indicate that the aromatic amino acids are extensively exposed to solvent. the cd and ord spectra are characteristic of a high ... | 1975 | 236026 |
| accelerated host metabolism of l-thyroxine during acute infection: role of the leukocyte and peripheral leukocytosis. | metabolism of thyroid hormones is accelerated during acute infection in man and in experimental animals. the pathogenetic mechanisms mediating this phenomenon are uncertain, but activated leukocytes of the infected host have been implicated as potentially important sites of hormone degradation. the present studies were conducted in an attempt to assess the in vivo contribution of leukocytes and peripheral leukocytosis to the enhancement of l-thyroxine (t4) clearance seen during infection, and to ... | 1975 | 236322 |
| the lipopolysaccharides of neisseria gonorrhoeae colony types 1 and 4. | the lipopolysaccharides (lps) of strains of neisseria gonorrhoeae grown in type 1 (t1) and 4 (t4) colony forms have been isolated. lps from t4 colony type cells on mild hydrolysis gave a lipid a and a core oligosaccharide composed of 2-amino-2-deoxy-d-glucose, d-glucose, d-galactose, l-glycero-d-manno-heptose and 3-deoxy-d-manno-octuosonic acid that appeared to be common to all the strains examined. lps from t1 colony type cells on mild hydrolysis gave a lipid a and high molecular weight o polys ... | 1975 | 237620 |
| gene 21 protein-dependent proteolysis in vitro of purified gene 22 product of bacteriophage t4. | 1975 | 238040 | |
| excision of bromodeoxyuridine from t4-dna by an antimutator polymerase of t4 phage. | with gene-43 (dna polymerase)-ts-mutants of t4 phage, l98 (mutator) and cb121 (antimutator), and the t4 wild type, double labelling of dna was carried out with (h3)-bromodeoxyuridine (budr) and (c14)-thymidine (tdr). experiments on (c14) tdr for dna synthesis measurement in the presence of budr offered evidence of the ability of the cb121 mutant to excise budr from the dna. this effect took place only at increased temperature. as distinct from dna synthesis of the host, all t4 phages used prefer ... | 1975 | 239571 |
| polyacrylamide gel electrophoresis of intact bacteriophage t4d particles. | a method for the electrophoresis of intact bacteriophage t4d particles through polyacrylamide gels has been developed. it was found that phage particles will migrate through dilute polyacrylamide gels (less than 2.1%) in the presence of a low concentration of mgcl2. as few as 5 x 10(9) phage particles can be seen directly as a light-scattering band during the course of electrophoresis. the band can also be detected by scanning gels at 260 to 265 nm or by eluting viable phage particles from gel s ... | 1975 | 240037 |
| studies of the self-association of bacteriophage t4 gene 32 protein by equilibrium sedimentation. | 1975 | 241852 | |
| bacteriophage t4 whiskers: a rudimentary environment-sensing device. | the 400 a filaments or "whiskers," which extend outward from the collar region of the phage, control retraction and extension of the tail fibers in response to certain environmental conditions. the tail fibers of normal phage retract in the absence of a required adsorption cofactor, at low ph, at low ionic strength, at low temperature, and at high concentrations of polyethylene glycol. the tail fibers of mutant whiskerless (wac) phage still retract under the first two conditions, but not the las ... | 1975 | 242007 |
| pituitary stalk-section and some of its effects on endocrine function in the fetal lamb. | a detailed description is given of a method to section the pituitary stalk of the fetal lamb after 105 days gestational age. the approach to the stalk is made through a window in the frontal bone. in order to prevent regeneration of the hypothalamo-pituitary connections a silicone plate is introduced through the probe used to fracture the stalk. the surgical outcome and viability of 11 pituitary stalk sectioned fetuses is described over periods of up to 23 days. the presence of pituitary infarct ... | 1978 | 250110 |
| diffusion-controlled reactions on spherical surfaces. application to bacteriophage tail fiber attachment. | we have explored the kinetic implications of a model that may account for the acceleration of tail fiber (f) attachment to baseplates (b) by whiskers (w) on bacteriophage t4. the model assumes that a w-f complex is formed initially, and that the tethered fiber then undergoes rotational diffusion until a b-f encounter takes place. in the absence of whiskers, b-f complexes must form unassisted. formation of a w-f intermediate will accelerate f attachment to b if (a) the bimolecular rate constant f ... | 1979 | 262439 |
| thyroid hormone and thyrotropin levels in patients placed on colestipol hydrochloride. | bile acid sequestrant resins can bind t4 in vitro and in the gut. therefore, the effect of colestipol hcl on thyroid function was studied prospectively in 17 subjects with type ii hyperlipoproteinemia. serum t4, t3, t3 resin uptake, and tsh levels were measured before and during therapy. no change in t4 levels and only small transient, but significant, decreases in t3 were noted in a minority of patients; tsh levels did not change. small increases in t3 resin uptake were noted. we conclude that ... | 1978 | 262768 |
| serum 3,5,3'-triiodothyronine, thyroxine, and thyrotropin in hypothyroid infants with congenital goiter and the response to iodine. | iodine deficiency in adults caused preferred synthesis of t3; this observation has not been reported in iodine-deficient hypothyroid newborns. serum total t4, total t3, and tsh have been determined in nine full term newborns with congenital hypothyroid goiter before and after cutaneous application of iodine. the mothers of these infants had untreated euthyroid goiter and lived during pregnancy in the area of göttingen, west germany, known as an iodine-deficient region. mean total t4 in the newbo ... | 1978 | 263290 |
| damped oscillations in serum thyroid hormone levels of normal newborn infants. | exposure to the extrauterine environment is associated with marked stimulation of the hypothalamic-pituitary-thyroid system after which, pituitary-thyroid equilibrium must be reestablished. this marked endogenous perturbation offers the opportunity to study the manner in which the pituitary-thyroid axis is reequilibrated. t4, t3 and tsh concentrations have been measured by ria in sera from 440 healthy newborn infants, whose ages ranged from birth to 236 h. results were analyzed by nonlinear curv ... | 1978 | 263295 |
| metabolic clearance and production rates of 3,3',5-triiodothyronine in hyperthyroid, euthyroid, and hypothyroid subjects. | to further elucidate the peripheral metabolism of rt3 and to determine if rt3 production rates vary directly with thyroid function, we measured the disappearance of [125i]rt3 in thyrotoxic and hypothyroid subjects as well as in athyreotic patients maintained eumetabolic on exogenous t4. kinetic parameters were determined by noncompartmental analysis, and serum concentrations of rt3 and t4 were determined by specific rias. in six hyperthyroid, seven euthyroid, and six hypothyroid subjects, the mc ... | 1978 | 263302 |
| fetal hypothyroidism and maternal thyroid status in severe endemic goiter. | the relationship between maternal thyroid function and newborn thyroid function was studied in a region of very severe endemic goiter (ubangi, republic of zaïre). t4, t3, and tsh concentrations were measured in the sera of 56 mothers (at the time of delivery) and 60 newborns (in the cord). the results obtained in these groups (untreated) were compared with those obtained in two control groups, comprising 53 mothers whose iodine deficiency had been corrected by the injection of iodized oil and 68 ... | 1978 | 263304 |
| 3,3',5'-triiodothyronine, thyroxine, triiodothyronine, and thyrotropin levels in maternal and cord blood sera from endemic goiter regions of brazil. | t4, t3, rt3, and tsh were measured in cord blood of infants born in mild to severe endemic goiter areas and nonendemic urban areas in south and north america. a significantly high rt3 concentration was found in newborns living in the urban area of south america as compared to a canadian newborn population. there were no differences among the various thyroid parameters in the groups of newborns studied. blood from goitrous mothers showed significantly higher concentrations of t3 and tsh than nong ... | 1978 | 263309 |
| effect of propranolol on extrathyroidal metabolism of thyroxine and 3,3',5-triiodothyronine evaluated by noncompartmental kinetics. | kinetic studies of t4 and t3 using a noncompartmental approach were performed in seven patients with pretreatment severe hypothyroidism maintained on l-t4 replacement. each subject received a combined tracer dose of labeled t4 and t3 as an iv bolus before and during peroral treatment with propranolol. serum t4 was unchanged, while a significant decrease of 13% was found in serum t3. the disposal rates (dr) of t4 and t3 decreased significantly, and the ratio between the dr off t3 and the dr of t4 ... | 1978 | 263312 |
| effect of starvation on the production and peripheral metabolism of 3,3',5'-triiodothyronine in euthyroid obese subjects. | the effect of starvation on the peripheral metabolism of rt3 was evaluated in four obese euthyroid patients. during starvation, the serum rt3 concentration increased by 69% while the mcr of rt3 decreased in all four patients from control values of 96 +/- 23 (mean +/- sd) to 68 +/- 17 liters/70 kg . day, resulting in a slight increase in the mean production rate of rt3. these findings are in contrast to the marked decrease in t3 production rate associated with fasting, indicating that inner and o ... | 1978 | 263330 |
| effect of intraamniotic fluid thyroxine injection on fetal serum and amniotic fluid iodothyronine concentrations. | seven hundred micrograms of t4 were injected into the amniotic cavity 24 h before delivery of five pregnant women scheduled for elective cesarean section at term. t4, t3, and rt3 concentrations were measured by ria in amniotic fluid obtained at the time of the injection and in amniotic fluid and cord serum samples collected at delivery. iodothyronine concentrations also were determined on cord samples from 24 full term control infants. the geometric mean serum t4 concentration in the experimenta ... | 1978 | 263334 |
| a radioimmunoassay for 3',5'-diiodothyronine. | the present report describes a ria for 3',5'-diiodothyronine (t2) that can be performed on unextracted serum and which has a lower limit of detectability of 2 ng/dl. cross-reactivity with other iodothyronines was negligible, except for rt3 which began to demonstrate cross-reactivity when rt3 levels were elevated to 180 ng/dl. employing this ria for t2, we have determined that 83 healthy individuals had a mean (+/-se) serum t2 concentration of 5.0 +/- 0.3 ng/dl, thyrotoxic subjects (n = 12) had ... | 1978 | 263335 |
| low serum triiodothyronine and high serum reverse triiodothyronine in old age: an effect of disease not age. | serum concentrations of t4, t3, t3, free t4, free t3, and tsh were determined in four groups of adult subjects: group a, 27 healthy young volunteers (aged 18-29 yr); group b, 24 carefully selected healthy elderly subjects (aged 70-90 yr); group c, 41 subjects living at a municipal nursing home for the elderly (aged 70-90 yr); and group d, 35 hospitalized patients (aged 70-90 yr). identical levels of iodothyronines in serum were found in the young and in the elderly healthy subjects. moderate and ... | 1978 | 263341 |
| effects of dexamethasone on fetal and maternal thyroxine, triiodothyronine, reverse triiodothyronine, and thyrotropin levels. | the concentrations of t4, t3, rt3, and tsh were measured at term pregnancy in maternal and umbilical plasma and in amniotic fluid of 11 normal patients who received 8-16 mg dexamethasone 3-48 h before elective cesarean section and of 10 control patients who received no dexamethasone. the mean (+/- se) concentrations of t4 (micrograms per dl) in maternal and umbilical plasma of dexamethasone-treated patients (12.5 +/- 0.9 and 13.0 +/- 0.9) were not significantly different (p less than 0.05) from ... | 1978 | 263347 |
| evidence that triiodothyronine and reverse triiodothyronine are sequentially deiodinated in man. | we have demonstrated that in patients given a single iv injection of t3, rt3, or, to a lesser extent, t4, all labeled with 125i in the outer or phenolic ring, chromatography of serum on columns of sephadex g-25 superfine revealed the presence of a labeled material, separate from the administered hormone and from both iodide and iodoprotein. this peak has been termed pre-t3 because it elutes just before the t3 peak. identification of the various compounds in pre-t3 was carried out by cation excha ... | 1978 | 263472 |
| appearance of labeled metabolites in the serum of man after the administration of labeled thyroxine, triiodothyronine (t3), and reverse triiodothyronine (rt3). | chromatography of serum on columns of sephadex g-25 superfine after the iv administration of 125i-labeled t4 consistently yielded labeled iodide, iodoprotein, t3, and a labeled peak that eluted from the column before the t3, termed "pre-t3." much larger quantities of pre-t3 were generated after the iv administration of 125i-labeled t3 and rt3. the ratio of [125i]pre t3:[125i]t3 and [125i]pre t3:[125i]rt3 plateaued at approximately 10 h and 2 h, respectively, after the iv administration of the la ... | 1978 | 263473 |
| difference in pituitary-thyroid feedback regulation in hypothyroid patients, depending on the severity of hypothyroidism. | in an attempt to study pituitary-thyroid interplay during replacement therapy for hypothyroidism, t4 (75-150 micrograms/day) was administered for at least 3 months. a small dose of t4 (75 micrograms/day) significantly depressed basal and trh-stimulated tsh levels in normal subjects without significantly elevating serum t4 and t3 concentrations. in patients with severe hypothyroidism and marked enlargement of the sella turcica, t4 (2.53 micrograms/kg bw) normalized the serum t4 and slightly eleva ... | 1978 | 263732 |
| 3'-5'-diiodothyronine in health and disease: studies by a radioimmunoassay. | a simple, reproducible, and highly specific ria has been developed for measurement of 3',5'-diiodothyronine ((3',5'-t2) in unextracted serum. interference in binding of radioactive 3',5'-t2 to anti-3',5'-t2 by serum proteins was minimized by using 0.4 m phosphate buffer (ph 6.2) and merthiolate. the detection threshold of the ria was 2.5 ng/100 ml. recovery of nonradioactive 3',5'-t2 added to serum averaged 99%. t4, t3, and rt3 cross-reacted with 3',5'-t2-binding sites on anti-3',5'-t2 antibody ... | 1978 | 263734 |
| the effect of repeated administration of ipodate (oragrafin) in hyperthyroidism. | this report describes the effect of administration of repeated doses of ipodate (oragrafin; 3 g orally every third day for five doses) in six hyperthyroid patients. baseline serum concentrations of immunoassayable t3, rt3, and t4, were 926 +/- 206 ng/100 ml, 165 +/- 31 ng/100 ml and 21 +/- 2.7 micrograms/100 ml (mean +/- sem), respectively. within 24 h after the first dose of ipodate, serum t3 fell by 54% and it remained between 66-77% below baseline until the third day after the fifth dose; sub ... | 1978 | 263735 |
| iodoamino acids in abnormal and grossly normal thyroids: comparison between 125i and 127i distribution. | patients with thyroid cyst (tc), non-toxic nodular goiter (nng), follicular adenoma (fa) and papillary carcinoma (pc) were given a tracer dose of 125i 40h prior to surgery. tissue specimens were hydrolysed with pronase and their labeled iodocompound distribution determined by paper or thin layer chromatography; they were then derivatized and their stable iodoamino acids (iaa) determined by gas liquid chromatography (glc). specific activity (sa) of mit, dit and t4 was within the same range in tc, ... | 1977 | 267712 |
| dna packaging and the pathway of bacteriophage t4 head assembly. | a cold-sensitive mutation in the structural gene for a minor phage t4 capsid protein (p20) leads to formation of heads containing p20 and cleaved head proteins and empty of dna. such heads can be filled with dna and converted to active phages in vivo uponshift to high temperature. it appears that p20 has two distinct roles in head assembly: first, in construction of the prehead shell (blocked by ts and am mutation) and, second,in dna packaging (blocked by cs mutation). the latter function is clo ... | 1977 | 269421 |
| 2-aminopurine-induced mutagenesis in t4 bacteriophage: a model relating mutation frequency to 2-aminopurine incorporation in dna. | we measured the in vivo incorporation of 2-aminopurine into dna of t4 bacteriophage allelic for gene 43 (dna polymerase), mutator (l56), 43+, and antimutator (l141). the magnitude of incorporation (mol/mol of thy) was 1/1500 in l56, 1/1600 in 43+, and 1/8900 in l141. the incorporation ratio l56:43+:l141 in vivo was equal to that mediated by the purified dna polymerases of these allelic phages in vitro. a model for 2-aminopurine-induced a-t in equilibrium g-c transitions is discussed. the model i ... | 1977 | 270713 |
| phage t4-modified rna polymerase transcribes t4 late genes in vitro. | initiation of t4 late rna synthesis has been achieved in an in vitro system prepared from escherichia coli cells infected with wild-type or maturation-defective mutant t4 phage. the system uses a cellophane membrane as a mechanical support for concentrated cell lysates and for added streptolydigin-resistant rna polymerases. transcriptional activity and selectivity of added rna polymerases are tested while endogenous rna polymerase activity is inhibited by streptolydigin. t4-modified rna polymera ... | 1977 | 271954 |
| new method for localizing proteins in periodic structures: fab fragment labeling combined with image processing of electron micrographs. | fab fragments prepared from antisera directed against purified bacteriophage t4 structural proteins and head-related structures were used to label proteins on the surface of t-even giant phage capsids. optically filtered electron micrographs of the fab-labeled capsids reveal both the location of specific proteins within the capsomeres and differing conformational states of the protein subunits. we describe parameters affecting the utility of this technique for the study of molecular organization ... | 1977 | 271974 |
| structure of nascent replicative form dna of coliphage m13. | nascent replicative form type ii (rfii) dna of coliphage m13 synthesized in an escherichia coli mutant deficient in the 5' leads to 3' exonuclease associated uith dna polymerase i contains ribonucleotides that are retained in the covalently closed rfi dna sealed in vitro by the joint action of t5 phage dna polymerase and t4 phage dna ligase. these rfi molecules are labile to alkali and rnase h, unlike the rfi produced either in vivo or from rfii with e. coli dna polymerase i and e. coli dna liga ... | 1978 | 272630 |
| a cell-free assay measuring repair dna synthesis in human fibroblasts. | osmotic disruption of confluent cultured human fibroblasts that have been irradiated or exposed to chemical carcinogens allows the specific measurement of repair dna synthesis using dttp as a precursor. fibroblasts similarly prepared from various xeroderma pigmentosum cell lines show the deficiencies of uv-induced dna synthesis predicted from in vivo studies, while giving normal responses to methyl methanesulfonate. a pyrimidine-dimer-specific enzyme, t4 endonuclease v, stimulated the rate of uv ... | 1978 | 273917 |
| addition of mononucleotides to oligoribonucleotide acceptors with t4 rna ligase. | rna ligase induced by bacteriophage t4 catalyzed the addition of nucleoside 5',3'-diphosphates to oligoribonucleotide acceptors in the presence of atp. the reactions proceeded in equimolar concentrations of donors and acceptors. several oligonucleotides of defined sequence were synthesized by this method in yields of 28-68%. the enzyme required the phosphate ester at the 3' position of the donor molecule, nucleoside 5',2'-diphosphates being unable to serve as donors. thymidine 5',3'-diphosphate ... | 1978 | 274717 |
| effects of triiodothyronine administration in patients with chronic renal failure. | clinically euthyroid patients with severe, chronic, non-thyroidal illnesses usually have decreased serum total and absolute free t3 concentrations. since t3 is the metabolically more active of the two thyroid hormones, it has been suggested that these patients may be hypothyroid and thus may benefit from t3 therapy. to test this hypothesis, five patients with chronic renal failure requiring maintenance haemodialysis were treated with 5 microgram t3 eight hourly, increasing at three weekly interv ... | 1977 | 274939 |
| phage t4 endonuclease v stimulates dna repair replication in isolated nuclei from ultraviolet-irradiated human cells, including xeroderma pigmentosum fibroblasts. | the repair mode of dna replication has been demonstrated in isolated nuclei from uv-irradiated human cells. nuclei are incubated in a mixture containing [(3)h]thymidine triphosphate and bromodeoxyuridine triphosphate in a 1:5 ratio. the (3)h at the density of parental dna in alkaline cscl density gradients is then a measure of repair. in nuclei prepared from wi38 cells 30 min after irradiation, repair replication is uv dependent and proceeds at approximately the in vivo rate for 5 min. repair re ... | 1978 | 275829 |
| a general method to assess similarity of protein structures, with applications to t4 bacteriophage lysozyme. | a method is proposed that permits the structural similarity between any pair of proteins to be analyzed in a completely general manner. in the proposed procedure, all possible structural segments of a given length from one protein are compared with all possible segments from the other protein. this set of comparisons reveals any structural similarities between the two proteins being compared, and also provides a basis for estimating the probability that a particular degree of structural homology ... | 1978 | 276859 |
| kinetic factors and form determination of the head of bacteriophage t4. | the form of the bacteriophage t4 prehead is described by its icosahedral symmetry, its diameter, and its length. we show how each of these parameters is regulated during prehead formation and ascribe specific form-determining functions to the prehead proteins. the major protein of the head shell can assemble in several different forms. the structure produced in vivo depends on the rate of synthesis of the major protein relative to the rates of synthesis of minor shell proteins and the major core ... | 1978 | 279906 |
| dextrothyroxine treatment of phosphorylase-kinase deficiency glycogenosis in four boys. | four boys, aged 2 years 5 months to 3 years 7 months, with large hepatomegaly due to phosphorylase-kinase deficiency glycogenosis, were given a trial of sodium dextrothyroxine (d-t4) at a mean dose of 0.165 mg/kg/day for an average period of 6 months. phosphorylase-kinase was undetectable in the haemolysates of erythrocytes (3 patients) or in the liver (one patient) before, and still undetectable in the haemolysates of the four patients during treatment, thus pointing to x-linked phosphorylase-k ... | 1978 | 280544 |
| temperature-sensitive mutation in the initiation codon of the riib gene of bacteriophage t4. | we have determined the sequence of a ribosome-protected region of t4 riib mrna labeled in vivo. the riib mutant hd263, which is temperature sensitive for translation, has an altered initiation codon (aua instead of aug). because wild-type and hd263 proteins have the same fmet peptide, this aua is used to initiate translation in the mutant riib mrna. we have also identified a six-base sequence which is complementary to the 3" end of the 16s rrna. | 1979 | 284393 |
| the effect of suppressive therapy of nontoxic diffuse goiter on serum levels of thyroxine, 3,5,3'-triiodothyronine and 3,3',5'-triiodothyronine. | we studied the effect of suppressive therapy with graded doses of thyroxine (t4) on serum levels of t4, 3,5,3'-triiodothyronine (t3) and 3,3',5'-triiodothyronine [rt3] in patients with diffuse, nontoxic goiter. for comparison and in order to elucidate the degree of suppression of the pituitary thyroid axis by t3 the effect of suppressive therapy with t3 was studied in the same type of patients. we found that t4 in serum rose significantly to a constant level during t4 treatment (0.10, 0.15 and 0 ... | 1979 | 284710 |
| the influence of propranolol on the extrathyroidal metabolism of 3,3',5'-triiodothyronine (reverse t3). | the effect of propranolol 80 mg daily on the metabolism of 3,3',5'-triiodothyronine (reverse t3, rt3), 3,3',5'-triiodothyronine (t3) and thyroxine (t4) was studied by means of a non compartmental kinetic method in seven females with severe pretreatment hypothyroidism. the patients were maintained euthyroid on a constant l-t4 replacement therapy. serum rt3 levels increased significantly during propranolol (p less than 0.02). this increase was explained by a decrease in metabolic clearance rate (m ... | 1979 | 284711 |
| recombination in phage t4 gene-43 (dna polymerase) mutants. | the effect of phage t4 gene 43 (dna polymerase) mutations on recombination between adjacent base pairs was measured in rii amber and opal mutants. the mutator allele tsl56 did not promote recombination frequencies at the two sites in which its effect was studied. the antimutator allele tscb87 caused slight or no reduction in recombination frequencies at five sites. | 1979 | 286143 |