| effect of ionic strength and ionic composition of assay buffers on the interaction of thyroxine with plasma proteins. | when plasma proteins are diluted with buffer the ionic strength and ionic composition of that buffer affects the interactions between thyroxine (t4) and its plasma protein-binding sites. increases in phosphate, chloride or barbiturate ion concentration from 50 to 200 mmol/l caused a significant decrease in the affinity of plasma proteins for t4, and a concurrent increase in the concentration of unbound t4. these results cannot be completely accounted for by changes in ionic strength since at the ... | 1975 | 447 |
| bacteriophage t4 baseplate components. ii. binding and location of bacteriophage-induced dihydrofolate reductase. | the location of t4d phage-induced dihydrofolate reductase (dfr) has been determined in intact and incomplete phage particles. it has been found that phage mutants inducing a temperature-sensitive dfr (dfrts) procude heat-labile phage particles. the structural dfr produced by these ts mutants was shown to assume different configurations depending on the temperature at which the phage is assembled. morphogenesis of incomplete phage particles lacking the gene 11 protein on their baseplates was foun ... | 1975 | 516 |
| preparations and properties of ribonucleic acid polymerase from acinetobacter calcoaceticus. | deoxyribonucleic acid (dna)-dependent ribonucleic acid (rna) polymerase (ec 2.7.7.6) from acinetobacter calcoaceticus was purified to apparent homogeneity and its properties were compared with those of the escherichia coli b enzyme. the molecular weights of the two native active enzymes as well as their alpha and beta subunits appeared to be similar. no subunit corresponding to that of sigma from e. coli was found, and furthermore no separation between the beta subunits could be detected by gel ... | 1976 | 1380 |
| reflex sympathetic tachycardia during intravenous infusions in chronic spinal cats. | the reflex tachycardia elicited by rapid intravenous infusions of a blood substitute was studied in 21 chronic cats with spinal sections at c8. all animals could breath spontaneously. the day after section the average resting heart rate (hr) and arterial pressure (ap) were 109 beats/min and 98/67 mmhg, respectively. vagal blockade with atropine (0.5-0.7 mg/kg iv) was performed prior to each infusion, increasing the average hr to 127 beats/min. in 39 infusions in 21 cats the average increase in h ... | 1976 | 3115 |
| sialic acid in thyroglobulin. ii. influence of sialic acid on ionization of tyrosine residues. | during electrophoresis in polyacrylamide gel at ph 9-5, it was noticed that sialic acid-poor thyroglobulin contains fewer low molecular weight fragments than sialic acid-rich thyroglobulin. splitting off of sialic acid diminishes thenumber of phenolic groups of tyrosine, mit, dit and t4, which dissociate below ph 12-5. this phenomenon was interpreted as a result of lowered hydrophilia of these regions of the thyroglobulin molecule which contains tyrosine and its iodinated derivatives. | 1975 | 3147 |
| gel filtration and related studies on the reconstitution of bacteriophage t4. | | 1975 | 3469 |
| isoaccepting species of serine trna coded by bacteriophage t5sto. | by aminoacyl-trna-dna hybridization and chromatographic analysis, evidence was provided that the bacteriophage t5sto codes for two trnaser species. trinucleotide- or polynucleotide-stimulated binding experiments assigned the codons ucc or ucu to these two trnaser species. they also suggested that the synthesis of these two trnaser species does not modify the reading capacity for codons less used in escherichia coli f and corresponds to a different situation compared with the t4-coded trna's. | 1976 | 3665 |
| biological properties of an improved transformation assay for native and denatured t4 dna. | | 1976 | 3880 |
| ribonucleic acid synthesized in meiotic cells of saccharomyces cerevisiae: effect of culture medium ph. | pulse-labeled ribonucleic acid (rna) was extracted from polysomes of sporulating cells of saccharomyces cerevisiae and characterized in sucrose gradients and by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. transfer rna, ribosomal rna, and heterodisperse rna, presumed to be messenger rna, were synthesized during a 20-min pulse at t4 and t6 when labeling was performed in sporulation medium adjusted to ph 6.0. furthermore, ribosomal rna was processed into functional ribosomes during t ... | 1976 | 4430 |
| 5' leads to 3'-exonucleases of bacteriophage t4. | two enzyme activities which release nucleotides preferentially from the 5' termini of dna were found in t4-infected escherichia coli. since no corresponding activities were found in uninfected cells, the activities appeared to be induced by t4. both activities are capable of excising pyrimidine dimers from ultraviolet-irradiated dna which has been treated with t4 endonuclease v. one of the activities , referred to as t4 exonuclease b, was purified 400-fold from an extract of t4v 1- infected cell ... | 1976 | 4453 |
| demonstration and some properties of cytosol-binding proteins for thyroxine and triiodothyronine in human liver. | cytosol-binding proteins for l-thyroxine (t4) and triiodo-l-thyronine (t3) were studied in human liver specimens obtained at autopsy from 5 male and 2 female subjects. the liver cytosol containing 131i-t4 or t3, together with or without added stable hormones, was fractionated by pevikon thin-layer electrophoresis at ph 8.6, 8.0, and7.4. it was demonstrated in all the specimens that besides a small amount of serum t4-binding globulin, there existed three t4-binding proteins, termed ht4-1, ht4-2 a ... | 1976 | 4465 |
| heat mutagenesis in bacteriophage t4: the transition pathway. | g-c leads to a-t transitions are induced by heat, and arise from the deamination of cytosine (5-hydroxymethylcytosine in the case of bacteriophage t4) generating uracil. the reaction is proton-catalyzed, and is also characteristic of acid mutagenesis. mutation rates and activation energies of mutation are site-specific, and are presumably influenced by neighboring bases. rates of heat-induced mutation in bacteriophage t4 under conditions of temperature, ph, and ionic strength similar to those pr ... | 1976 | 4797 |
| bacteriophage t4 prehead proteinase. i. purification and properties of a bacteriophage enzyme which cleaves the capsid precursor proteins. | | 1976 | 12371 |
| role of urinary solutes in natural immunity to gonorrhea. | natural resistance of the male urethra to gonococci has not been explained by classical immune mechanisms but could result from antibacterial properties of urine. accordingly, we measured survival in midmorning urine of 10(7) f-62 t2 gonococci per ml by serial dilutions and plate counts. fifteen killer urines from eight people all killed greater than 3 logs (average, 5.3), and 13 of 15 were sterilized. fourteen nonkiller (inhibitor) urines from seven subjects allowed no growth. killer urines wer ... | 1977 | 13038 |
| packaging of genomes in bacteriophages: a comparison of ssrna bacteriophages and dsdna bacteriophages. | in complex dna bacteriophages like lambda, t4, t7, p22, p2, the dna is packaged into a preformed precursor particle which sometimes has a smaller size and often a shape different from that of the phage head. this packaging mechanism is different from the one suggested for the rna phages, according to which rna nucleates the shell formation. the different mechanisms could be understood by comparing the genomes to be packaged: single stranded fii rna has a very compact structure with high helix co ... | 1976 | 13425 |
| studies on the maturation of the head of bacteriophage t4. | the presentation focuses on the structural rearrangements of the subunits and the processing of the various protein constituents which accompany the maturation events of the head of bacteriophage t4. the major features of the maturation steps of the head are the following: (a) the viral dna is pulled into an empty head in a series of events; (b) cleavage of two core proteins, p22 (mol. mass = 31000), to small fragments and the internal protein ipiii (mol. mass = 23000) to ipiii (mol. mass = 2100 ... | 1976 | 13426 |
| dna viruses: cooperativity and regulation through conformational changes as features of phage assembly. | the assembly of bacteriophages provides experimental model systems for the study of regulation at the level of gene products. we discuss the hypothesis of regulation through sequentially induced conformational changes by which precursor-assemblies become ready at a specific stage of maturation to interact with an additional gene product or nucleic acids. phage mutants provide excellent experimental model systems for studying, for example, the role and fate of the core in the prehead assembly. th ... | 1976 | 13433 |
| endonuclease of t4 ghosts. | | 1977 | 13531 |
| the two dispensable structural proteins (soc and hoc) of the t4 phage capsid; their purification and properties, isolation and characterization of the defective mutants, and their binding with the defective heads in vitro. | | 1977 | 15127 |
| equimolar addition of oligoribonucleotides with t4 rna ligase. | t4 induced rna ligase will join equimolar concentrations of two oligoribonucleotides, (ap)3c and p(up) 5, to form a single product, (ap)3cp(up) 5, in high yield. the presence of the 3' phosphate on p(up)5 prevents the oligomer from adding to itself. the ph optimum of the reaction is about 7.5, but less of the undesirable adenylated intermediate, app(up) 5, forms at ph 8.2. the reaction rate is a linear function of oligomer concentration from 3 micronm to 0.6 mm. the data suggest that t4 rna lig ... | 1977 | 17097 |
| properties of the thyroxine (t4) monodeiodinating system in rat liver homogenate. | the monodeiodination of t4 in rat liver homogenate was studied. the two possible products of this reaction show very different properties. the metabolically very active t3 is rather stable in this system whereas the biological inactive reverse t3 (rt3) disappears very rapidly. this explains the low apparent rt3 production in the incubation mixture even under optimal conditions and the peculiar ph profile. the t4 to t3 converting reaction can be increased by the addition of mercaptoethanol to the ... | 1977 | 18299 |
| conversion of t4 to t3 and rt3 and their cytoplasmic binding: ph dependency. | the fate of t4 in target organs is conversion to t3 which is mainly responsible for the nuclear action of thyroid hormones. to further investigate this converting step the increase of t3 and its analogue rt3 in rat liver microsomes was measured by specific radioimmunoassays after adding t4 to the incubation medium. maximal increase of t3 occurred at ph 6.0 and of rt3 at ph 9.5 indicating that two different enzymic systems may be involved in the deiodination of the tyrosyl or the phenolic ring of ... | 1977 | 18300 |
| a study of extrathyroidal conversion of thyroxine (t4) to 3,3',5-triiodothyronine (t3) in vitro. | | 1977 | 18337 |
| purification and properties of a t4 bacteriophage factor that modifies valyl-trna synthetase of escherichia coli. | after t4 bacteriophage infects escherichia coli, a peptide tau, produced under the control of a phage gene, binds to the host valyl transfer ribonucleic acid synthetase (ec 6.1.1.9) and thereby changes several of its physicochemical properties. the interaction of tau with the host enzyme was investigated in vitro after extensively purifying the factor from t4-infected e. coli using a rapid purification procedure. the tau preparation migrated as a single, protein-staining band with a molecular we ... | 1977 | 19475 |
| analysis of the activity of micrococcus luteus endonucleases with respect to gamma-irradiated dna. | endonucleases from micrococcus luteus that induce single-strand breaks in gamma-irradiated dna have been separated chromatographycally into two groups. the first group involves two different enzymes: ap-endonuclease ii (mol. weight 30 000) and ap, uv-endonuclease i (mol. weight 15 000) that recognize alkali-labile lesions in gamma-irradiated dna and apurinic sites in dna heated at 70 degrees c, ph 6.08 ap-endonuclease ii in cooperation with dna polymerase from m. luteus and t4 phage-induced poly ... | 1977 | 20161 |
| assembly of bacteriophage t4 head-related structures. assembly of polyheads in vitro. | | 1977 | 20510 |
| characterization of human thyroxine-binding globulin. evidence for a single polypeptide chain. | thyroxine-binding globulin (tbg) was purified from fresh human plasma by affinity, anion exchange, and gel filtration chromatography. the protein gave a single band in overloaded analytical disc gel electrophoresis. the molecular weight was 54,000 and e1%/1 cm at 280 nm, corrected for thyroxine (t4) absorbance, was 6.17. six preparations of tbg contained from 0.09 to 0.64 mol of t4/mol; the tbg used in this study contained 0.19 mol of t4 and was able to bind an additional 0.85 mol. the carbohydr ... | 1977 | 21881 |
| the effect of thyroxine on the 2,3-diphosphoglycerate content of erythrocytes in vivo and in vitro. | after ending a continous treatment with thyroxine the average dropping of the 2,3 dpg level was 0.4 mumol/ml. t4 decreased on the average by 7.6 microgram/ml. one time application of 1 mg thyroxine p.o. led within 24 hours to an increase of the 2,3 dpg level of -chi = 0.2 mumol/ml, the ph in the erythrocytes increased by 0.02 on the average. blood incubation with thyroxine added in a concentration of -chi = 24 microgram/100 ml showed no increase of 2,3 dpg, ph and phosphate, while there was a si ... | 1977 | 23631 |
| regulation of thyroid hormone metabolism in rat liver fractions. | the nature of the conversion of thyroxine (t4) to triiodothyronine (t3) and reverse triiodothyronine (rt3) was investigated in rat liver homogenate and microsomes. a 6-fold rise of t3 and 2.5-fold rise of rt3 levels determined by specific radioimmunoassays was observed over 6 h after the addition of t4. an enzymic process is suggested that converts t4 to t3 and rt3. for t3 the optimal ph is 6 and for rt3, 9.5. the converting activity for both t3 and rt3 is temperature dependent and can be suppre ... | 1978 | 23865 |
| how thyroid disease presents in the elderly. | some of the symptoms and signs of hypothyroidism and hyperthyroidism in elderly patients may be mistakenly attributed to "old age." weight loss, muscle weakness, tremor, angina, congestive heart failure--all signs of hyperthyroidism--are also concomitants of aging. fatigue, sluggishness, withdrawal behavior, senile atrophic skin changes--all signs of hypothroidism--are also a part of the normal aging process. although screening elderly people for thyroid disease is economically unsound, the phys ... | 1978 | 24576 |
| apropos of complications following the use of methylmethacrylate. possible prevention by betamethasone. | the aim of this study was to determine whether the prior injection of betamethasone was capable of preventing blood pressure changes and the fall in arterial po2 when following the fixation of total hip protheses with methyl metacrylate. it involved 54 patients in whom systolic, diastolic and mean blood pressure (bp), arterial po2, pco2 and heart rate were noted at different times: t1, 15 minutes after the beginning of the operation; t2 and t3, one minute and five minutes after application of th ... | 1978 | 28053 |
| effect of starvation, nutriment replacement, and hypothyroidism on in vitro hepatic t4 to t3 conversion in the rat. | to evaluate the effect of starvation, oral and i.v. nutriments, and hypothyroidism on the peripheral conversion of thyroxine (t4) to 3,3', 5-triiodothyronine (t3) in the rat and mouse, an in vitro system for assessing t4 conversion to t3 by fresh liver homogenates was used. a 2-day starvation in the rat reduced hepatic t3 generation from t4 by 47% +/- 3.5% (mean +/- se) in six separate experiments and also impaired the metabolism of 125i-r-t3. administration of carbohydrate (cho) and amino acids ... | 1978 | 30020 |
| conversion of t3 and rt3 to 3,3'-t2: ph dependency. | in the extrathyroidal deiodination of t4 the importance of t3 and rt3 for the peripheral action of thyroid hormones is well documented. with the development of a specific radioimmunoassay for 3,3'-t2, a deiodination product of both t3 and rt3, we were able to characterize these subsequent enzymatic reactions as well as the degradation of 3,3'-t2 in rat liver homogenate. it was found that the reaction t3 leads to 3,3'-t2 is slow compared to the conversion of t4 to t3. the ph activity profile show ... | 1978 | 31249 |
| [new aspects in the treatment of elderly people with carcinoma of the urinary bladder (author's transl)]. | 50% of the patients with carcinoma of the bladder are older than 70 years. during the first examination a deep muscle invasion was found in about 60%. (stages t3/t4. this situation makes forced surgical intervention in most cases impossible (e.g. radical cystectomy and segmental resection), therefore the transuretheral resection has to be the leading therapeutical procedure. during the past 10 years 80% of the bladder cancer patients were treated by tur most ofter followed by external irradiatio ... | 1979 | 33571 |
| attachment of bacteria to exfoliated cells from the urogenital tract. | to establish urogenital infections, organisms must adhere to the mucosal lining. a differential adherence capacity among various bacterial species was observed when exfoliated urethral and urothelial cells were tested in an in vitro system. no difference in the adherence capacity of a particular species was observed when tested with exfoliated cells obtained from voided urine from different healthy individuals of the same sex. escherichia coli harvested directly from urine specimens of patients ... | 1979 | 34577 |
| [role of proton motive force in the infection of e. coli k-12 cells by bacteriophage t4]. | it was shown that infection of e. coli cells by phage t4 is suppressed, when the cells are treated by oxidative phosphorylation uncouplers. the inhibiting effects of the uncouplers manifest themselves at the stage of phage dna entry into the cells. study of the e. coli cells devoid of their h+-atpase activity due to mutation showed that the infection is suppressed by a switch-off of the respiratory chain, the only generator of the proton motive force (pmf) in mutated cells. infection of the e. c ... | 1979 | 35241 |
| the effect of oral thyrotropin-releasing hormone on thyroid function and the composition of breast milk in puerperal women. | to determine the effect of oral administration of thyrotropin-releasing hormone (trh) on the thyroid function and on the composition of breast milk in the early puerperium, six lactating women were treated with a single dose of 40 mg of synthetic trh and six women were treated with placebo. serial serum samples taken before and between one and 25 hours after trh administration were assayed with specific radioimmunoassays for thyrotropin (tsh), triiodothyronine (t3) and total thyroxine (t4). milk ... | 1979 | 35406 |
| tyrosine hydroxylase and the conversion of l-thyroxine into 3',3,5-triiodo-l-thyronone in the rat. | we have studied the effects of alpha-methyl-p-tyrosine (alpha-mpt), an inhibitor of tyrosine hydroxylase, on the in vivo conversion of l-t4 (t4) to 3',3,5-triiodo-l-thyronine (t3), and on the biological effectiveness of t4. thyroidectomized rats were used and were injected daily with t4 maintenance doses. three different types of experiments were carred out. the first involved isotopic equilibration with 125i-labeled t4 and measurement of urinary 125i excretion. the second series involved the in ... | 1979 | 36273 |
| observations on the factors that control the generation of triiodothyronine from thyroxine in rat liver and the nature of the defect induced by fasting. | studies were performed to explore the mechanism underlying the impaired generation of 125-i-3,5,3'-triiodothyronine (t3) from 125i-thyroxine (t4) (t3-neogenesis)) in preparations of liver from rats fasted for 48 h and the prevention of this effect by the feeding of glucose. t3-neogenesis in livers from fasted animals and those fed chow or glucose was assessed in various mixtures of crude microsomal fractions with either buffer or cytosols. t3-neogenesis was mediated by an enzyme present in the m ... | 1979 | 36408 |
| attachment of neisseria gonorrhoeae to human sperm. microscopical study of trypsin and iron. | pilated neisseria gonorrhoeae of colony type 1 (t1) and non-pilated bacteria of colony type 4 (t4) were observed by transmission (tem) and scanning electron microscopy (sem). no pili were observed on t4 gonogocci, but two types of pili--straight, type a, and bent, type b--were seen on t1 by tem. when incubated with human sperum and examined by either tem or sem, t1 gonococci were seen to attach by individual pili, by several pili wound together as a rope, or by direct contact. gonococci from t4 ... | 1979 | 39583 |
| the relative merits of polyethyleneglycol as a separating agent in the radioimmunoassay of thyroid hormones. | polyethyleneglycol (peg) has been recommended as a separating agent in the assay of some peptide hormones (desbuquois, b. and aurbach, g.d. (1971) j. clin. endocrinol. 33, 732) and several substances of low molecular weight (ratcliffe, j.g. (1974) br. med. bull. 30, 32). in the present study the peg-separation technique has been modified and adapted for the assay of thyroid hormones. separation with peg has the advantage of being cheap, rapid and relatively non-susceptible to disturbances as com ... | 1979 | 39694 |
| iodoamino acid synthesis in thyroid lobes in vitro with excellent yield of iodothyronines. | thyroid lobes of male sprague-dawley rats on an iodine-sufficient diet were incubated in our improved in vitro system with 0.01 microm 127i and 5mu/ml of bovine tsh. thyroidal 131i-uptake and the relative incorporation of iodine into iodothyronines increased with time. the average yield of each iodoamino acid after 8 h of incubation was: monoiodotyrosine 28.0%, diiodotyrosine 46.5%, triiodothyronine 1.9% and thyroxine 13.9%, which showed a striking resemblance to the values obtained in vivo. the ... | 1979 | 40373 |
| [the neuroendocrine response to alfatesine or ethrane anesthesia in humans]. | the description of neuro-endocrine effects due to surgical stress and certain anaesthetic products led the authors to look for the action of alfadione and enflurane on the hypothalamic-hypophyseal-thyroidian-adrenal axis. taking 20 subjects who were divided into three groups of 10, the authors measured the plasma levels of t3, t4, tsh, cortisol and acth during anaesthesia with alfadione (without surgery). this was group i. group ii were patients during surgery under alfadione. group iii was duri ... | 1979 | 40485 |
| plasma triiodothyronines in fetal sheep: effects of illness and thyroidectomy. | plasma 3,5,3'-triiodothyronine (t3) and 3,3',5'-triiodothyronine concentrations were measured in fetal sheep prior to death in utero and after thyroidectomy. in six fetal sheep who subsequently died in utero, plasma rt3 concentrations were elevated in all for 2 to 13 days prior to death. there were no consistent changes in plasma t4 concentrations. in two thyroidectomized fetal sheep, plasma t4 and rt3 concentrations fell to low levels. plasma t3 concentrations remained low and there was no incr ... | 1979 | 40859 |
| requirement for membrane potential in injection of phage t4 dna. | the first stages of infection by phage t4 may be divided into energy-dependent and energy-independent processes. irreversible adsorption, unplugging, and initial exposure of the dna terminus may occur at 4 degrees c, or at 37 degrees c in bacteria whose energy-yielding metabolism has been poisoned. dna injection into the cytoplasm needs higher temperatures and energy from the host cell. the nature of this energy requirements was deduced from the use of metabolic inhibitors. our results show that ... | 1979 | 41245 |
| control of cfuc proliferation by selective endogenous inhibitors. | the susceptibility of mouse bone marrow colony forming cells (cfuc) to three different types of proliferation inhibitors in capillary semisolid agar gel was studied. gi-3, a target specific peptide containing granulocyte fraction, t4-1, an oligospecific thymic factor of proteid nature, and the alkylating cytostatics dianhydrogalactitol (dad) inhibit myeloid colony formation as a function of concentration. the respective med values amount to 8, 10, and 0.002 microgram/ml. when compared with this ... | 1979 | 42209 |
| ph modification of the effects of detergents on the stability of enteric viruses. | the effect of detergents on the stability of enteric viruses was found to be highly dependent on ph. this was demonstrated primarily with two ionic detergents, sodium dodecyl sulfate (an anionic detergent) and dodecyltrimethylammonium chloride (a cationic detergent). both detergents were shown to be potent virucidal agents for reovirus, but the effects of sodium dodecyl sulfate were minimal near neutrality and much more pronounced at low than at high ph values. dodecyltrimethylammonium chloride ... | 1979 | 42351 |
| stability of phage t4 lysozymes. ii. unfolding with guanidinium chloride. | the denaturation by guanidinium chloride of three phage lysozymes (wild type and two mutants) was investigated. the study of solvent denaturation permitted the investigation of the relative stabilities of the proteins at neutral ph, in contrast to thermal denaturation studies reported earlier which could only be performed in acid ph. the results were interpreted assuming that the free energy of solution of proteins is a linear function of denaturant concentration. using standard thermodynamic fo ... | 1979 | 42444 |
| free t4, free t3 and free reverse t3 in dialysates of serum. the influence of electrolytes and ph with special reference to the physiological range. | the influence of electrolyte composition and ph of buffer on free t4, free rt3, and free t3 concentrations in serum dialysates has been evaluated, using an equilibrium dialysis method with subsequent direct radioimmunoassay estimations of the dialysate. cl-, hco3- and h+ were found to be the important ions which at concentrations similar to those occurring in vivo decreased the protein binding of all three hormones in serum, t3 being much less sensitive to these changes than t4 and rt3. the poss ... | 1979 | 42963 |
| effect of beta-blocking agents in hyperthyroidism. | propranolol modifies peripheral thyroxine metabolism, in opposition to the beta blocking agent gyki 41099 which has no such effect. both beta-receptor blockers produce a significant fall in the serum camp level of hyperthyroid subjects. it is suggested that the beneficial effect of the beta-blocking agents in hyperthyroidism is partly due to their depressive effect on camp production. as far as the action of propranolol is concerned, it may well involve an additional effect on t4 metabolism. | 1979 | 45285 |
| failure of alpha-methyltyrosine to inhibit peripheral triiodothyronine formation. | to determine if the adrenergic nervous system, and specifically tyrosine hydroxylase, plays a role in the extrathyroidal conversion of t4 to t3, normal male volunteers were treated with t4 and subsequently with t4 and alpha-methyl-p-tyrosine (alpha-mpt), an inhibitor of tyrosine hydroxylase, for 2 weeks. the mean serum t4 and t3 concentrations increased during t4 administration and remained at the same levels during combined t4 and alpha-mpt administration. urinary vanillylmandelic acid excretio ... | 1978 | 45464 |
| physical mapping of the restriction fragments obtained from bacteriophage t4 dc-dna with the restriction endonucleases smai, kpni and bglii. | the cytosine-containing dna of a mutant of bacteriophage t4 was digested with restriction endonucleases smai, kpni and bglii producing 5, 7 and 13 fragments respectively. complete physical maps of the t4 genome were constructed with the enzymes smai and kpni and an almost complete map with the enzyme bglii. | 1979 | 45792 |
| carrier-determined tolerance in vitro. | a primary immune response to normal bdf1 spleen cells was obtained in vitro to the t-independent antigen tnp-t4 coliphage. this anti-tnp response was suppressed by exposing the spleen cells for 6 hr to tnp bound either to isologous or heterologous gamma-globulin. the suppression was hapten specific. in contrast, tnp-albumin conjugates did not induce tolerance in vitro. | 1975 | 46237 |
| letter: does t4 toxicosis exist? | | 1975 | 46567 |
| stimulation with thyrotrophin-releasing hormone (trh) during antithyroid treatment. | during antithyroid treatment a total of 88 trh tests was performed in 56 clinical euthyroid patients. 56% had negative response to trh (i.e. delta tsh smaller than 2 muu/ml) after being treated in average 12.6 months and no relation between the duration of treatment and the outcome of the trh test was found. in the group with positive trh tests (i.e. delta tsh greater than 2 muu/ml) the mean t4 value was slightly decreased (5.8 plus or minus sd 2.5 mug/100 ml) while the mean t3 value was normal ... | 1975 | 47216 |
| letter: does t4-toxicosis exist. | | 1975 | 47524 |
| the thyroid in ulcreative colitis and crohn's disease. iii. the daily fractional turnover of thyroxine. | the daily fractional turnover of thyroxine (t4) labelled with 131 i has been determined in 11 patients with ulcerative colitis (uc) of crohn's disease and 8 controls. the daily fractional turnover of 131i-t4 was significantly increased in the patient group. the daily total disposal of t4 iodine was not significantly different although it was excessive in 3 of the 11 patients. the amount of t4 in plasma did not differ significantly between the patients and the controls. it is concluded that the t ... | 1975 | 47700 |
| letter: does t4 toxicosis exist? | | 1975 | 48107 |
| hormonal pattern of relapse in hyperthyroidism. | 22 patients with grave's disease were followed up for up to a year after antithyroid drug therapy was discontinued. clinical assessment and serum t3, t4, and thyroid-stimulating-hormone (t.s.h.) estimations were done serially and simultaneously. serum t3 or t4 concentrations may be elevated briefly in the first few weeks after antithyroid drugs are stopped, as a rebound effect not necessarily indicative of subsequent relapsf. clinical relapse of hyperthyroidism with subsequent improvement on ant ... | 1975 | 48121 |
| [diagnosis and control of therapy of thyroid disorders by trh-test (author's transl)]. | tsh-measurement before and after stimulation with trh proved to be of good value in the diagnosis of thyroid dysfunctions, better than other parameters including j-131-test. during treatment of hypothyroid disorder trh-test, often repeatable, allows estimation of t4 substitution dosis. in graves disease therapy, furthermore, should be judged by in-vitro or clinical parameters. | 1975 | 48181 |
| effect of butyldiiodohydroxybenzoate on pituitary-thyroid interplay. | the effect of bhdb, an analogue of thyroxine, on the pituitary-thyroid system was studied in the rat. bhdb produced low plasma t4 and t3 concentrations similar to those produced by methimazole, but failed to elevate plasma tsh and to produce goiter because of displacement of t4 from the binding protein. low plasma thyroid hormone concentrations were due to an increase of fecal loss of thyroid hormones. by releasing excess iodide, bhdb blocked the development of goiter produced by methimazole. | 1975 | 48263 |
| serum triiodothyronine 7-15 years after fractionated low dose radioiodine therapy of thyrotoxicosis. | in 189 of 334 patients, who had been treated with fractionated doses of radioiodine for graves' disease 7-15 years ago, the serum concentrations of triiodothyronine have been estimated in additition to the following parameters: protein bound 127-iodine (pb-127-i), free thyroxine index, cholesterol- and tsh-level in serum, tendon reflex time and clinical index according to billewitz et al. (1969). in forty-one of the 189 sera the free t4 (aft4) and free t3 (aft3) concentrations were measured as w ... | 1975 | 48437 |
| letter: does t4-toxicosis exist? | | 1975 | 48915 |
| rapid effects of single small doses of l-thyroxine and triiodo-l-thyronine on growth hormone, as studied in the rat by radioimmunoassy. | the effects of thyroid hormone deprivation and restitution on growth hormone (gh) economy have been studied in the rat by means of a specific radioimmunoassay. the pituitary gh content and the plasma gh levels before and during stimulation with pentobarbital ("pb-test") were studied in male rats at different intervals after surgical thyroidectomy (t), and in t rats at different time intervals after the ip injection of 0.20, 1.75, and 5.0 mug thyroxine (t4) or 0.05, 0.10, 0.20 and 1.0 mug triiodo ... | 1975 | 49266 |
| preparation of 125-i-labeled human thyroxine-binding alpha globulin and its turnover in normal and hypothyroid subjects. | a protein with the electrophoretic, immunologic, and hormone-binding properties of thyroxine-binding globulin (tbg) has been prepared from human plasma and labeled with radioiodine (125-i) by an enzymatic method of iodination. the [125-i]tbg retained the electrophoretic and immunologic characteristics of unlabeled tbg but exhibited a partial loss of thyroxine-binding activity, as assessed by affinity chromatography. the in vivo behavior of [125i]tbg was studied in six euthyroid subjects (control ... | 1975 | 49363 |
| is "t4 toxicosis" a normal biochemical finding in elderly women? | the lack of equivalence in the distrubtion of normal ranges for free thyroxine index (ft4i) and free triiodothyronine index (ft3i) in the over sixty-five age-group, as compared with the fifteen-sixty-five age-group, supports the idea that "t4 toxicosis" is a common biochemical finding in elderly women. the disparity between ft4i and ft3i ranges was also reflected in the true free t4 and free t3 levels which were measured in some cases. these results suggest that when an increased ft4i is found i ... | 1975 | 49741 |
| third hl-a segregant series: genetic analysis and molecular independence on lymphocyte surface. | five sera which detect two alleles of the third hl-a locus (t2 and t4) are described. statistical analysis of a panel of 220 donors gave gene frequencies in a french parisian population which are comparable to the results of scandinavian authors. segregation observed in 50 families emphasized the linkage disequilibrium with sd2 alleles. t1 was found to be associated with one part of w22 (da30) and t3 with the other part non-da30). no recombination was observed between sd2 and sd3, and the dista ... | 1975 | 50634 |
| [relation of trh test to thyroidal suppression test by triiodothyronine in patients with hyperthyroidism under treatment with antithyroid drugs (author's transl)]. | the relation of the trh test to the t3 suppression test was investigated in 43 patients with hyperthyroidism receiving antithyroid drugs for 6 to 27 months (average 14 months). trh tests were performed by measuring serum tsh levels before and 15, 30, 45, 60, 90 and 120 minutes after intravenous injection of 500 mug of synthetic trh. serum tsh was measured by a double antibody radioimmunoassay. two weeks later, the t3 suppression test was performed by measuring the 24-hr thyroidal uptake of radio ... | 1975 | 50954 |
| acute changes in thyroid function in patients treated with radioactive iodine. | serum triiodothyronine (t3) and thyroxine (t4) were measured in thirteen unselected hyperthyroid patients before and at frequent intervals after iodine-131 treatment. there was an abrupt rise in t3 from a pretreatment mean of 250 ng/100 ml to a maximum of 365 ng/100 ml at 24 hours. total t4 rose from a mean of 18.7 mug/100 ml to a maximum of 22.3 mug/100 ml at 24-48 hours. these findings may explain why an occasional patient develops acute thyroid crisis after radioiodine treatment. | 1975 | 52005 |
| letter: t4 toxicosis. | | 1975 | 52028 |
| normal response to thyrotrophin releasing hormone (trh) in familial thyroxine-binding globulin deficiency. | the response in serum thyrotrophin (tsh) to thyrotrophin releasing hormone (trh) has been studied in 5 euthyroid patients with familial thyroxine-binding globulin (tbg) deficiency. total serum thyroxine (t4), serum triiodothyronine (t3) and free t4 index and free t3 index were significantly and equally decreased, but in spite of these findings the serum tsh and response to trh was normal. the trh test seems to be a better indicator of the euthyroid state in familial tbg deficiency than the measu ... | 1975 | 52266 |
| thyroxine utilization rate in sucking pigs. | in 10 suckling pigs age 28--34 days, thyroxine utilization rate (tur) was determined by means of the isotope dilution procedure. for this purpose biological half-life of t4 was estimated during 96 h of blood sampling and serum t4 concentration was measured directly by a competitive protein-binding technique. high rate of the peripheral hormonal-iodine metabolism (from 10.3 +/- 0.6 to 21.2 +/- 1.2 mug t4/kg/day) was found in the one-month old pigs. tur value calculated for these pigs corresponds ... | 1975 | 52283 |
| [excessive peripheral conversion of thyroxine (t4) to triiodothyronine (t3) in the pathogenesis of t3-hyperthyroidism (author's transl)]. | in a 41-year-old woman and a 3-year-old girl, both of them with t3-thyrotoxicosis, serum levels of total and free t4 and t3 were measured serially during anti-thyroid drug treatment. attempts to substitute thyroxine during the antithyroid treatment had to be interrupted because the patients became hyperthyroid again with excessive increases in total and free serum t3, even when concentrations of total and free t4 were brought to subnormal levels. the increased conversion of administered thyroxin ... | 1975 | 52434 |
| determinants of the hierarchy of humoral immune responsiveness during ontogeny. | a model system of ontogeny was utilized to investigate the development of humoral immunity in both akr and balb/c mice. lethally irradiated adult mice were reconstituted with syngeneic fetal or neonatal liver. these mice were immunized at various times after reconstitution with a series of eight antigens: the bacteriophages f2, phix-174, and t4; the hapten carrier complexes 2,4 dinitrophenyl-bovine serum albumin and fluorescein-bovine serum albumin; and the small proteins: hen egg lysozyme, sper ... | 1975 | 52670 |
| [correlation studies of some thyroid function tests (author's transl)]. | the results of a thyroid test based on ion exchange and column chromatographic separation and of two radiochemical t4 and three t3 tests were carried out with commercially available reagent packs ready for use, and were compared with the pbi values found in the same serum sample in each case. this also tested the analytical precision of each method. a good correlation was found between the pbi and the t4 values, while the accuracy of the t3 tests was unsatisfactory. | 1975 | 52835 |
| [proceedings: pituitary thyroid axis in subacute thyroiditis (author's transl)]. | we studied 10 patients with subacute thyroiditis. all had an increase in free thyroxine index, pbi, t4 and pbi/t4 ratio, an absence of thyroidal radioiodine uptake and no increase in plasma tsh after trh injection. exogenous tsh increased the uptake in 6/9 patients. the three patients who did not respond to tsh had higher pbi/t4 ratio than others. after treatment for one month there was either a normalization of laboratory tests either a subnormal thyroid function associated with an absence of r ... | 1975 | 53025 |
| a temporal component of the auditory evoked response. | we studied the 75-225 msec portion of the auditory evoked response (aer) in 32 normal adults at vertex (cz) and temporal (t3 and t4) placements referred to a balanced, noncephalic reference electrode using a monaural 1 msec click stimulus delivered every 4.7 sec at 60 db above threshold. the tape-recorded eeg was filtered at 1-25 c/sec, and 128 individual responses were summed, sampling every 0.5 msec for 250 msec post-stimulation. the cz aers showed the classic vertex response, a negative peak, ... | 1975 | 53139 |
| triiodothyronine and thyroid-stimulating hormone in protein-calorie malnutrition in infants. | protein-calorie malnutrition (p.c.m.) in a group of 43 senegalese children aged eighteen to thirty months was characterised by a sharp fall in serum-triiodothyronine (t3) concentration to 25-3% of the mean value in healthy age-matched controls. this decrease in t3 was significantly (p less than 0-001) more pronounced in kwashiorkor of recent onset than in long-term p.c.m., a finding which suggests that impaired thyroxine (t4) monodeiodination in the liver was responsible for the fall in serum-t3 ... | 1975 | 53331 |
| value of routine serum-triiodothyronine estimation in diagnosis of thyrotoxicosis. | thyroid-stimulating hormone (t.s.h.), triiodothyronine (t3), and thyroxine (t4) concentrations were estimated on 432 blood specimens from patients with a provisional diagnosis of thyrotoxicosis. 59 patients had a raised serum t3 concentration with t.s.h. and t4 levels in the normal range. further information was obtained in 41 of these patients, and t3 toxicosis was diagnosed in 17 cases, thus providing a projected total of 24 patients with t3 toxicosis. in addition, there were 56 patients, with ... | 1975 | 53496 |
| [influence of hypo- and hyperthyroidism on the turnover rate of noradrenaline, dopamine and serotonin in various rat cerebral structures]. | the effect of chronic treatment with tyroxine (t4) or propylthiouracile (ptu) on the turnover of norepinephrine (ne), dopamine (da) and 5-hydroxytryptamine (5-ht) has been studied in various areas of the rat brain (brain stem, hypothalamus, striatum and "rest of the brain"). the turnover of ne and da was determined by the decay in endogenous levels after inhibition of tyrosine hydroxylase by alpha-methylparatyrosine and the turnover of 5-ht was evaluated by the initial accumulation of endogenous ... | 1975 | 54127 |
| thyroidal triiodothyronine and thyroxine in graves' disease: correlation with presurgical treatment, thyroid status, and iodine content. | to evaluate the potential contribution of thyroidal secretion to the relative excess of triiodothyronine (t3) production in hyperthyroidism and to investigate the effects of treatment, iodine (127i), t3 and thyroxine (t4) were measured in digests of thyroid tissue obtained at surgery from 13 patients with graves' disease. in 11 normal human thyroid glands, 127i content was 630 +/- 60 (all values mean +/- se in mug/ wet weight) t4, 254 +/- 39 and t3 21 +/-3. the t4i was 26 +/- 3% of the total iod ... | 1975 | 54364 |
| serum triiodothyronine and reverse triiodothyronine concentrations after surgical operation. | serum-triiodothyronine (t3) concentrations fell rapidly after surgery in six out of seven initially euthyroid patients. simultaneous increases in reverse triiodothyronine (rt3) concentrations suggested that the peripheral monodeiodination of thyroxine (t4) proceeds by an alternative pathway in the postoperative period. | 1975 | 54799 |
| [diagnostic staged program in thyroid diseases]. | after some physiological principal remarks the modern possibilities of the in-vitro-diagnostics specific for the thyroid gland are briefly explained. the essential factors of disturbance which are necessary for the avoidance of false interpretations are mentioned. from the sequence of the description (bej, t4-test, t3-test, ft4-index, ria-t3 and ria-tsh) results the diagnostic step programme proposed by us, by means of which the majority of the functional disturbances of the thyroid gland existi ... | 1975 | 55003 |
| the thyroxine-binding properties of rat and rabbit serum proteins. | the thyroxine (t4) binding properties of rat and rabbit serum proteins were studied using a gel equilibration technique, gel filtration and polyacrylamide gel electrophoresis. in both species two different t4 binding molecules were identified in whole serum and in cohn fraction v preparations. only one of these binding species demonstrated the characteristics of specific binding, i.e., high affinity for the hormone and binding site saturability. the mean (+/- sd) apparent association constants ( ... | 1976 | 55359 |
| resin hemoperfusion: a method of removing circulating thyroid hormones. | the ability of an extracorporeal hemoperfusion system employing neutral amberlite resin to bind thyroid hormone and to decrease circulating levels of triiodothyronine (t3), thyroxine (t4), and free thyroxine (ft4) was evaluated in dogs made thyrotoxic by the intramuscular administration of thyroid hormone. since the resin column and tubing were charged with saline, the effects of hemodilution from this source on serum t3 and t4 was assessed by control perfusion through a column which did not con ... | 1976 | 55416 |
| [immunogenic properties of dna from e. coli and t4 phage, containing 5-bromouracil]. | 5-budr incorporated into e. coli or t4 phage dnas is an immunogenic determinant. immunodominance of 5-budr is determined by the chemical structure of dna molecule into which it is incorporated. in e. coli dna, 5-budr inhibits immunogenic activity of all other bases. one can conclude that in this dna 5-budr is the dominant antigenic determinant. in t4 dna, 5-budr acts as an additional antigenic determinant. anti-5-budr-t4-dna contains antibodies to 5-budr and glucosylated 5-hmc. | 1975 | 55955 |
| [the effect of contrast media containing iodine on selected in vitro thyroid test procedures (author's transl)]. | the effect of 6 commonly used contrast media on the results of 3 different methods for determination of thyroid hormone concentration in the serum is examined in vivo. t4 determination by column chromatography proved to be very liable to distortion for contrast media. with some contrast media the res-o-mat-etr test proved unreliable. t4 determination by means of protein binding analysis is not affected by contrast media in the direction of false raised values. | 1976 | 55963 |
| a transient rise of hormone secretion: a response of the stimulated rat thyroid gland to small increments of iodide supply. | small doses of iodide (2 times 3.2 mug at 12 h interval), below those capable of inducing wolff-chaikoff effect, were injected into rats kept on a moderately low iodine diet. by means of a 125i equilibration technique as well as by direct measurement of cold t4, it was demonstrated that the level of circulating pb125i (representing iodothyronines as confirmed by column chromatography) increased by a mean of 40% within 24 h following the first iodide injection. the serum tsh concentration (measur ... | 1976 | 56115 |
| thyrotoxicosis with painless thyroiditis. | four women and one man with painless subacute thyroiditis presented with hypermetabolic signs and symptoms. thyroxine (t4) and triiodothyronine (t3) resin uptakes (t3r) were increased but the 24 hour radioactive iodine (rai) uptakes were less than 1 per cent. surreptitious use of thyroid hormone was excluded. the thyroid was enlarged in one patient and nontender in all. exophthalmos was absent. the protein-bound iodine level was 1.1 to 9.5 mug/dl greater than the t4 level. the sedimentation rate ... | 1976 | 56130 |
| metabolism of thyroxine-binding globulin in man. abnormal rate of synthesis in inherited thyroxine-binding globulin deficiency and excess. | it has been previously suggested that inherited thyroxine-binding globulin (tbg) abnormalities in man may be due to mutations at a single x-chromosome-linked locus controlling tbg synthesis. however, abnormalities in tbg degradation have not been excluded. the availability of purified human tbg and its successful labeling with radioiodide allowed us to examine such possibility. human tbg was purified by affinity chromatography, labeled under sterile conditions with 131i or 125i,, and mixed with ... | 1976 | 56342 |
| [experiences in the determination of thyroxine iodine in serum in various functional conditions of the thyroid gland]. | a report is given on the method of the thyroxine iodine determination in the serum. of 213 patients the result of the thyroxine iodine determination was compared with the clinically and radiologically established functional condition of the thyroid gland. the findings are discussed. similar results were also reported of other in-vitro-tests (t3-test, t4-test, bej and pbj). according to our experiences we consider the thyroxine iodine determination in the serum siutable as screening test which - ... | 1975 | 56823 |
| total and free triiodothyronine and thyroid-binding globulin concentration in elderly human persons. | total thyroxine (tt4) and triiodothyronine (tt3) were found to be low in healthy elderly subjects with a preferential decrease of triiodothyronine. in order to determine the importance of these findings 22 healthy elderly subjects were examined. free triiodothyronine (ft3), thyroid binding globulin (tbg) concentration and basal thyroid stimulating hormone (tsh) were measured by radioimmunoassay. liver enzymes, cholesterol and total protein concentration were also assayed. tbg was significantly i ... | 1976 | 57057 |
| radioimmunoassay for serum thyroxine-binding globulin: results in normal subjects and in patients with hepatocellular carcinoma. | serum thyroxine-binding globulin (tbg) was measured by radioimmunoassay. the human tbg used in this study was purified by affinity, anion-exchange, and gel filtration chromatography. the serum tbg concentration in 98 euthyroid normals was 1.48 +/- 0.46 mg/100 ml (mean +/- sd), which is one-half that previously reported using a similar method. the level in females (1.66 +/- 0.56) was significantly higher than that in males (1.37 +/- 0.37). comparison of the serum tbg level and the maximum binding ... | 1976 | 57964 |
| immunoassay of human tsh using dried blood samples. | a sensitive, semi-quantitative radioimmunoassay method to screen for elevations of tsh concentration in blood is described. the method requires two 0.32 cm dots of dried blood-impregnated filter paper (equivalent to 3 mul plasma) and a 3-day incubation. separation of bound and free is obtained using polyethylene glycol. the method can recognize tsh concentrations as low as 22 muu/ml using a highly sensitive antiserum developed by one of us (afp). tsh in dried cord and newborn blood from 4 infant ... | 1976 | 57965 |
| evaluation of three thyroid-function screening tests for detecting neonatal hypothyroidism. | three thyroid-function detection methods were evaluated concomitantly for possible application as routine screening tests for the early diagnosis of neonatal hypothyroidism. dried capillary-blood thyroxine (t4) was measured on eluted filter-paper discs for 9734 3-5-day old neonates. serum t4 and thyroid-stimulating hormone (t.s.h.) assays from cord blood were studied as alternative screening tests on 4911 and 3733 infants, respectively. to avoid false-negative results, neonatal blood-t4 and cord ... | 1976 | 58257 |
| delayed response of ankle jerk time changes in decreasing thyroid function in comparison with the serum cholesterol changes. | 1. serum cholesterol, pbi and ankle jerk time (ajt) were measured simultaneously in a group of not yet treated patients, where a relatively steady state of thyroid function was expected, and in a treated group, where change to lower thyroid function was supposed (thyrostatic drugs, near total thyroidectomy, radioablation of thyroid). 2. serum cholesterol correlated poorly with pbi (r = --0,4427), better correlation was achieved after logarithmic transformation of pbi values (r = --0,6839). 3. re ... | 1975 | 58781 |
| isolation and characterization of t-even ghost-tolerant mutants of escherichia coli. | mutants of escherichia coli tolerant to the ghosts of t-even phages (t2, t4, and t6) have been isolated from a strain supersensitive to t6 phage. first, t6 supersensitive mutants were isolated from mutagenized e. coli w2252 by replica plating to t6 phage-overlaid agar. one of them, strain nm101, was mutagenized again, grown, and then plated with a high multiplicity of t4 and t6 ghosts. surviving cells were checked for tolerance to ghosts and adsorption of phages. one such ghost-tolerant mutant, ... | 1976 | 58859 |
| an improved quantitative plaque assay for lymphocytes bearing antigen-specific cell receptors. | an improved method for the determination of the number of lymphoid cells bearing antigen-specific receptors is described. the method is based on the use of hapten-coupled bacteriophage (dinitrophenyl-t4) and detection of lytic plaques formed by the action of dnp-t4 on a target e. coli strain. the method is highly specific (up to 90% specific binding) and can be adapted for use with other antigenic determinants chemically attached to an active bacteriophage. | 1976 | 58942 |
| hemodynamics of hyperthyroidism. the effects of autonomic nervous blocking and anti-thyroid drug treatment. | this work was intended to analyze the sympathetic and parasympathetic factors affecting the hemodynamics of hyperthyroidism. seven patients with hyperthyroidism, diagnosed based on the determinations of bmr, 131i-uptake, t3-resin sponge uptake (t3-rsu), and serum level of thyroxine (t4) were subjected to the study. the hemo-dynamic estimation was done (1) at rest, (2) after vagus blocking by the injection of 0.04 mg/kg b.wt. atropine and 0.2 mg/kg b.wt. propranolol before (hyperthyroid state=h) ... | 1976 | 59000 |
| effect of a single dose of dexamethasone on serum concentrations of thyroid hormones. | in ten euthyroid subjects, in whom endogenous thyroid-stimulating hormone (t.s.h.) production was suppressed by oral thyroxine (t4), a single dose of dexamethasone resulted in reduced serum-3,3'5-triidothyronine (t3) concentration and raised serum-3,3',5'-triiodothyronine (reverse t3 or rt3) concentration after 24 h. these changes were not related to changes in free hormones or binding proteins. adrenal glucocorticoids may have a pathophysiological role in modulating the peripheral metabolism of ... | 1976 | 59147 |