Showing papers by "Howard Hughes Medical Institute published in 1981"
TL;DR: Comparison of sequences near the 5' end of the hGH mRNA with a similar region of the alpha subunit of the human glycoprotein hormones reveals an unexpected region of homology between these otherwise unrelated peptide hormones.
Abstract: We have determined the complete sequence of the human growth hormone (hGH) gene and the position of the mature 5' end of the hGH mRNA within the sequence. Comparison of this sequence with that of a cloned hGH cDNA shows that the gene is interrupted by four intervening sequences. S1 mapping shows that one of these intervening sequences has two different 3' splice sites. These alternate splicing pathways generate hGH peptides of different sizes which are found in normal pituitaries. Comparison of sequences near the 5' end of the hGH mRNA with a similar region of the alpha subunit of the human glycoprotein hormones reveals an unexpected region of homology between these otherwise unrelated peptide hormones.
468 citations
262 citations
TL;DR: A murine hybridoma monoclonal anti-T-cell antibody was given to a patient with advanced cutaneous T cell lymphoma and the patient tolerated seventeen treatment courses over ten weeks without symptoms of toxicity.
255 citations
TL;DR: It is reported that three pseudogenes complementary to the small nuclear RNAs U1, U2 and U3 are dispersed and abundant in the human genome and the structure of all three pseudogene loci are flanked by perfect short direct repeats, which suggest that some Alu family sequences are mobile genetic elements that can transpose to new chromosomal loci.
236 citations
TL;DR: The results indicate that the adult central nervous system can give a very rapid biochemical response to thyroid hormone.
Abstract: In rats subjected to thyroidectomy there was a two- to fourfold increase in cerebral cortex iodothyronine 5'-deiodinase activity within 24 hours. This increase was prevented by thyroxine replacement. The increased cortical 5'-deiodinase in chronically hypothyroid rats was normalized within 4 hours by a single intravenous injection of triiodothyronine. These results indicate that the adult central nervous system can give a very rapid biochemical response to thyroid hormone.
206 citations
TL;DR: Southern transfer hybridization experiments, on DNA digested with enzymes that do not cut the major repeat unit of the family of genes of interest, reveal histone gene orphons in the sea urchin, ribosomal gene orPhon loci in yeast, and Ribosomal and H3 hist one gene orPHons in Drosophila melanogaster.
164 citations
TL;DR: Purified human T-lymphocytes exhibit 5-lipoxygenase activity as demonstrated by the conversion of arachidonic acid to 5-hydroxy-eicosatetraenoic acid and 5,12-di-HETE isomers of leukotriene B 4 that lack a 6-cis double bond.
136 citations
TL;DR: The location of glycine next to the carboxyl terminal prolinamide of calcitonin is consistent with indications that glycine is required for the enzymatic amidation of proline to the prolinamines in cellular biosynthesis.
Abstract: Recombinant DNA techniques were used to analyze the structure of the messenger RNA encoding a precursor of calcitonin, a small calcium-regulating hormone of 32 amino acids. Analyses of the nucleotide sequences of cloned complementary DNA's comprising the entire coding sequence of the messenger RNA revealed that calcitonin is flanked at both its amino and carboxyl termini by peptide extensions linked to the hormone by short sequences of basic amino acids. The location of glycine next to the carboxyl terminal prolinamide of calcitonin is consistent with indications that glycine is required for the enzymatic amidation of proline to the prolinamide. During cellular biosynthesis, calcitonin arises from a large precursor protein by cleavages at both amino and carboxyl terminal residues of the hormone. These findings raise questions concerning the regulation of these cleavages and the potential biological functions of the precursor extensions derived from these cleavages.
126 citations
TL;DR: Analysis of mousexhuman hybrid cells containing only part of the long arm of chromosome 17 enabled us to localize the genes for growth hormone and chorionic somatomammotropin to region 17q21→17qter.
Abstract: We used a cloned cDNA probe for human growth hormone and Southern blotting techniques to analyze DNA from a series of rodent x human somatic cell hybrids for the presence of growth hormone-related sequences. Our results provide evidence for the assignment of the genes for growth hormone and chorionic somatomammotropin as well as a growth hormone-like gene to human chromosome 17. Analysis of mouse x human hybrid cells containing only part of the long arm of chromosome 17 enabled us to localize these genes to region 17q21 to 17qter.
123 citations
TL;DR: The present communication describes the molecular cloning and DNA sequence determination of the rat growth hormone (rGH) gene, which was cloned on an 11 kilobase EcoRI fragment of total rat DNA and has four intervening sequences which correspond in position to those of the human growth hormones gene.
Abstract: The present communication describes the molecular cloning and DNA sequence determination of the rat growth hormone (rGH) gene. The rGH gene was cloned on an 11 kilobase EcoRI fragment of total rat DNA; it has four intervening sequences which correspond in position to those of the human growth hormone (hGH) gene. One of the intervening sequences in the rGH gene contains a possible transposable element: a 200 base pair direct repeat that is itself flanked by an exact 15 base pair direct repeat. The DNA sequence was used to estimate the location of the 5' end of the mature growth hormone mRNA. By S1 nuclease mapping it was located approximately 25 bases "downstream" from a TATAAA sequence presumed to play a role in initiation of transcription of the rGH gene.
120 citations
TL;DR: Guanine nucleotides were found to reduce the affinity of the agonist epinephrine at thealpha 2 sites labelled by [ 3 H]yohimbine but not at the alpha 1 sites labelled with prazosin, which has implications for the interpretation of agonist interactions with alpha receptors in liver membranes.
TL;DR: One mechanism by which cortisone modulates beta-adrenergic receptor function appears to be through facilitating the formation of the high affinity state of the receptor, resulting in greater coupling of receptor occupation with adenylate cyclase activation.
Abstract: β-Adrenergic agonists form high affinity complexes with receptors, resulting in activation of the associated adenylate cyclase. To examine the formation of the high affinity state of the receptor, curves were constructed for the competition of the full β-adrenergic agonist isoproterenol, partial agonists cobefrin and soterenol, and the antagonist propranolol for [3H]dihydroalprenolol binding to β-adrenergic receptors on human neutrophil membranes. Curve modeling by computer yielded a two-state binding model for the agonists, with distinct dissociation constants for the high (KH) and low (KL) affinity states. The ratio of dissociation constants (KL/KH) was found to be well correlated (P < 0.01) with the drug’s intrinsic activity for stimulation of adenylate cyclase. Thus, the degree of coupling of receptor occupation with adenylate cyclase activation is correlated with the magnitude of KL/KH. Administration of cortisone to humans resulted in a substantial rise in the proportion of receptors in the high aff...
TL;DR: The manifestations of peripheral thyroid hormone resistance are quite variable in the organ systems involved and in the degree of involvement, and the molecular basis of the abnormality in the patient remains undefined.
TL;DR: An allergoid of ragweed was produced by treating dialyzed defatted pollen extract under mild conditions with formaldehyde to have the desirable properties of reduced allergenicity, retained antigenicity, and prolonged stability for IgG antibody production.
Abstract: An allergoid of ragweed was produced by treating dialyzed defatted pollen extract under mild conditions with formaldehyde. This modified antigen was found to have the desirable properties of reduced allergenicity, retained antigenicity, and prolonged stability for IgG antibody production. A series of trials was carried out in ragweed-allergic patients from 1972 to 1978. In 1972 it was demonstrated that on average, allergoid had on the basis of antigen E content about one fiftieth the ability of unaltered whole ragweed extract (allergen) to induce local delayed and systemic allergic reactions when given subcutaneously. IgG antibody responses specific for allergen were readily induced. A blinded comparison in 1973 divided 48 highly sensitive patients into two groups on the basis of basophil sensitivity; one group was treated with allergoid and the other with allergen. In individuals never before treated, allergoid stimulated a significantly more rapid rise in IgG antibodies. Clinical evaluation in 45 of the patients gave a modest advantage (not significant) to allergoid. An open trial employing booster injections every 2 wk except during the ragweed season continued until 1978 in many of these patients and showed no evidence of long-term ill effects of allergoid. IgG antibody titers were maintained at a high level, and IgE antibodies, after a rise in the first year, declined slowly in both groups. Daily symptom-medication scores continued to be lower in the allergoid-treated group each year, and the difference was significant (p
TL;DR: DNA from healthy Malaysian newborns was studied on gene maps after digestion with different restriction endonucleases and the locations of the restriction sites in the two types of triplicated alpha-globin loci are compatible with a mechanism of unequal crossing over following two different modes of misalignment.
Abstract: DNA from healthy Malaysian newborns was studied on gene maps after digestion with different restriction endonucleases. Of 65 newborns, two were found to be carriers of two different variants of triplicated alpha-globin loci. In variant no. 1, found in an Malay, the three alpha-globin genes are in an elongated DNA fragment on digestion with Eco RI and Bam HI. The third alpha-globin gene was found in a additional 3.7-kb fragment on digestion with Hpa I, Bgl II and Hind III. In variant no. 2, a new type of triplicated alpha-globin loci, found in a Chinese, the three alpha-globin genes reside in an elongated DNA fragment longer than that of variant no. 1 on digestion with Eco RI and Bam HI. The third alpha-globin gene was found in an additional 4.2-kb fragment on digestion with Hpa I and Hind III. Digestion of this variant DNA with Bg1 II produced an abnormal 16.7-kb fragment in addition to the normal 7.0-kb Bgl-II fragment. The locations of the restriction sites in the two types of triplicated alpha-globin loci are compatible with a mechanism of unequal crossing over following two different modes of misalignment.
TL;DR: Among adult members of the O'D kindred the apo3-D phenotype was nearly specifically associated with dysbetalipoproteinemia or, when hyperlipidemia was present, type III hyperlipoproteinemi, consistent with the presence of familial combined hyperlipIDemia in this kindred.
Abstract: The largest reported kindred of a proband with type III hyperlipoproteinemia was investigated by assessment of lipid and lipoprotein levels and very low density lipoprotein (VLDL) isoapolipoprotein E distributions in all accessible family members (56% of the 124 living blood relatives and 59% of the 37 spouses). The results confirm in this kindred a trimodal distribution of apoE3/E2 ratios, and segregation analysis of 16 informative matings classified according to E 3 E 2 ratio demonstrated classical Mendelian inheritance of the autosomal codominant type: the E 3 E 2 ratio is determined by two alleles, apoE3d and apoE3n, which produce three phenotypes apoE3-D, apoE3-ND, and apoE3-N, corresponding to the low, intermediate, and high modes, respectively. Vertical transmission of the apoE3-D phenotype occurred in two branches of the second generation. In both instances this represented pseudodominance; i.e., products of heterozygous (apoE3-ND) × homozygous (apoE3-D) matings. Hyperlipidemia (defined as a low density lipoprotein cholesterol and/or plasma triglyceride level exceeding the respective age-, sex-, and sex-steroid-specific 95th percentiles derived from Lipid Research Clinics population studies) was present in 15 blood relatives in multiple lipoprotein patterns, consistent with the presence of familial combined hyperlipidemia in this kindred. Eight of nine members with the apoE3-D phenotype had either type III hyperlipoproteinemia or, in the absence of hyperlipidemia, β-VLDL and at least marginally cholesterol-rich VLDL (VLDL-cholesterol/plasma triglyceride >0.25) (defined as dysbetalipoproteinemia). The ninth such member, the only child with this phenotype, was normal. β-VLDL and marginally cholesterol-rich VLDL was seen in but one of six hyperlipidemic family members of phenotype apoE3-ND, in none of seven hyperlipidemic blood relatives of phenotype apoE3-N, in no normolipidemic family members of phenotype apoE3-ND or apoE3-N, and in no spouses (three of whom were hyperlipidemic and nine of phenotype apoE3-ND). Thus, among adult members of the O'D kindred the apo3-D phenotype was nearly specifically associated with dysbetalipoproteinemia or, when hyperlipidemia was present, type III hyperlipoproteinemia.
TL;DR: It is demonstrated that in hyperthyroidism, the isoproterenol curve in the absence of guanine nucleotides is shifted to the left with the EC50 changing from 180 ± 40 to 80 ± 20 nM, thus thyroid hormone can modify not only receptor number but agonist affinity as well.
TL;DR: Comparison of outcrossed and inbred SS populations suggests that relative well-being arises from homozygosity for alleles dictating high F-reticulocyte response to anemia.
Abstract: Strong correlation of F-reticulocyte levels within sib pairs with sickle cell (SS) anemia suggests that the wide-ranging levels found in the SS population are governed by genes linked to the beta S-site. Correlations between F-cell levels in parents and F-reticulocyte levels in their children indicates that these same genes regulate F-cell production in nonanemic persons. Comparison of outcrossed and inbred SS populations suggests that relative well-being arises from homozygosity for alleles dictating high F-reticulocyte response to anemia.
TL;DR: It is reported that the parent tetrapeptides and the substituted analogue Val-Pro-Ser-Glu (Pro3), but not histamine, increase the number of rat and human eosinophils that form rosettes with erythrocytes bearing IgG antibodies.
Abstract: Certain mast cell products, including the tetrapeptides Ala-Gly-Ser-Glu (Ala4) and Val-Gly-Ser-Glu (Val4) of the eosinophil chemotactic factor of anaphylaxis (ECF-A) and histamine, are preferentially chemotactic for eosinophils in vitro. Amino acid substitutions or modifications of the ECF-A tetrapeptides may substantially alter the chemotactic activity of human eosinophils. The cellular mechanism whereby ECF-A tetrapeptides enhance IgG-dependent killing of schistosomula by rat eosinophils is, however, unclear. We now report that the parent tetrapeptides and the substituted analogue Val-Pro-Ser-Glu (Pro3), but not histamine, increase the number of rat and human eosinophils that form rosettes with erythrocytes bearing IgG antibodies. Moreover, we find a correlation between the effect of these substances on the expression of rat eosinophil IgG Fc receptors and their capacity to increase the IgG-dependent cytotoxicity of rat eosinophils for Schistosoma mansoni schistosomula.
TL;DR: The ability of low concentrations of Mn ++ to selectively uncouple a functionally distinct pathway which mediates inhibition of adenylate cyclase by alpha-adrenergic agonists and guanine nucleotides should provide a useful tool for probing the mechanisms of hormonal regulation of the enzyme's activity.
TL;DR: Throughout their evolution, mammalian hemoglobins have acquired a broad repertoire of functional properties well suited to the internal milieu of the red cell, and mammals that have adapted to various types of hypoxia tend to have increased oxygen affinity, primarily mediated through reduced levels of red cell 2,3-DPG.
Journal Article•
TL;DR: Experimental findings are in very good agreement with Monte Carlo simulations and may help to explain the discrepancies in dissociation constants of high-affinity racemic radioligands reported in the literature.
Abstract: In receptor binding studies, high-affinity racemic radioligands are often used as tracers, neglecting the difference in affinity of their stereoisomers. We present an experimental and theoretical study comparing the binding of (±)-[3H]carazolol and (±)-[125I]hydroxy-benzylpindolol (HYP) to their pure respective isomers in the frog erythrocyte beta-adrenergic system. Saturation binding curves with the racemic radioligands showed deviations from a binding isotherm for a single ligand which were accentuated at higher receptor concentrations. When different affinity constants for both isomers were considered, significant improvement in the fits of the data were obtained by computer-modeling procedures. The KDav (average dissociation constant) obtained by considering the racemic radioligand as a single ligand, as has generally been done in the literature, varied with the receptor concentration from approximately 2 KD(-) at low receptor concentrations to ≅0.5 KD(+) at high receptor concentrations. Thus the generally measured "KDav" of these racemic radioligands is really a hybrid of KD(-) and KD(+). These experimental findings are in very good agreement with Monte Carlo simulations and may help to explain the discrepancies in dissociation constants of high-affinity racemic radioligands reported in the literature. Experimental data and simulations also indicate that information about the KD(-) is greatest at low receptor concentrations, whereas that about KD(+) is greatest at high receptor concentrations. Simultaneous computer fitting of saturation curves from racemic [125I]HYP and the (+)-isomer, isolated by repeated incubations with frog erythrocyte membranes under appropriate conditions, indicates approximately a 20-fold ratio for the individual isomer KD values. Estimated KD values of the stereoisomers of [125I]HYP and [3H]carazolol were virtually identical, being KD(-) = 10-50 pM and KD(+) ≅ 400-2000 pM at 25°. Use of the KDav for a racemic radioligand resulted in up to 5-fold systematic underestimation of the affinity of nonracemic competitors. The KD values of all high-affinity competitors were also found to be misestimated by as much as 10-fold using the commonly employed Cheng and Prusoff [Biochem. Pharmacol.22: 3099-3108 (1973)] approximation when the affinity of the radioligand was significantly lower than that of the competitor. Under such circumstances, slope factors of ≅2 were obtained for competition curves in the absence of cooperativity.
TL;DR: It is clear that the physiologically important deoxyadenosine phosphorylating activity is associated with the adenosine kinase enzyme, and the roles of specific nucleoside kinases in the metabolism of deoxyADenosine in human cells have been delineated.
TL;DR: A monoclonal antibody (immunoglobulin G1) has been produced that reacts against myelin basic protein present in or extracted from the brains of many mammals-with certain important exceptions.
Abstract: A monoclonal antibody (immunoglobulin G1) has been produced that reacts against myelin basic protein present in or extracted from the brains of many mammals-with certain important exceptions. Because of known species differences in amino acid sequences of basic protein and of certain peptide fragments, the binding site for this particular antibody appeared likely to include residues 130 to 137. Confirmation of this hypothesis was obtained by amino acid composition of the major immunoreactive peptides produced by thermolysin digestion of human basic protein and isolated by high-performance liquid chromatography.
TL;DR: Antiviral activity characterized as human interferon (HuIFN) was demonstrated in vesicle fluid from lesions of recurrent herpes labialis in 18 of 19 otherwise healthy patients, indicating that HuIFN-alpha is present in the local lesions of repeated herpesvirus infections.
Abstract: Antiviral activity characterized as human interferon (HuIFN) was demonstrated in vesicle fluid from lesions of recurrent herpes labialis in 18 of 19 otherwise healthy patients. High titers (geometric mean, 29,200 units) were present during the early course of lesion development. Antiviral activity in vesicle fluid was neutralized by antibody to leukocyte (types I) HuIFN (HuIFN-alpha) in the eight patients in whom it was tested. These results indicate that HuIFN-alpha is present in the local lesions of recurrent herpes labialis. HuIFN may have a role in the pathogenesis of recurrent herpesvirus infections.
TL;DR: When alpha2 adrenergic receptors were solubilized from human platelet particulate preparations with digitonin and centrifuged on sucrose density gradients, the sedimentation coefficient of the agonist-labelled receptor was greater than that of the antagonist-labelling receptor.
TL;DR: Studies with confluent human skin fibroblasts maintained in 0.5% serum supplemented medium have given new insight into the regulatory influences of ascorbate, indicating that the rate of collagen synthesis is not controlled by the level of prolyl hydroxylase.
TL;DR: The results suggest that adrenal steroid hormones may regulate the ability of the beta-adrenergic receptors to form a high-affinity "coupled" state, presumably by modulating the interaction of the receptor with nucleotide regulatory proteins.
Abstract: Adrenal steroid hormones potentiate beta-adrenergic actions on the heart. Accordingly, we investigated the effects of adrenalectomy on agonist and antagonist interactions with myocardial beta-adrenergic receptors and adenylate cyclase. The affinity and number of beta-adrenergic receptor sites, both defined by the antagonist (-) [3H]dihydroalprenolol, did not change after adrenalectomy. Computer modelling of agonist (-)-isoproterenol competition curves indicated the presence of two discrete receptor states with high and low affinities. After adrenalectomy, the agonist curves were shifted to the right, and the dissociation constant of the high-affinity state significantly rose from 12 to 48 nM (p < .001), but the dissociation constant of the low affinity state was unchanged. Although basal, maximal isoproterenol-stimulated and fluoride-stimulated adenylate cyclase activities were unaltered, the EC50 for isoproterenol stimulation was increased significantly from 490 to 1500 nM (p <.018). These results suggest that adrenal steroid hormones may regulate the ability of the beta-adrenergic receptors to form a high-affinity "coupled" state, presumably by modulating the interaction of the receptor with nucleotide regulatory proteins.
TL;DR: Comparison of the kinetics of in vitro release of known antigens from short ragweed pollen revealed a slow release of AgE but a rapid release of other highly allergenic components, suggesting that response to allergens in ragweed and other inhalants may enhance AgE release and thereby aggravate allergic symptoms.
Abstract: Study of the kinetics of in vitro release of known antigens from short ragweed pollen revealed a slow release of AgE (1.5% to 4% release after 16 min) but a rapid release of other highly allergenic components. The rapidly released allergens in 16-min pollen extracts were found to be mainly highly basic proteins including the well-characterized Ra5 molecule along with several hitherto uncharacterized components. Considering previous data that suggest that particles of a similar size to ragweed pollen grains remain in the nose only about 6 to 8 min following inhalation, it is difficult to explain the apparent anomaly between the high biologic potency of 16-min extracts and their low AgE content. Increase in the pH of the extracting buffer from the physiologically normal nasal pH of 5.5 to 6.5 to about pH 8.0 to 8.5 (characteristically found in rhinitis) increased the proportion of AgE released after 16-min extraction by about 10-fold, suggesting that response to allergens in ragweed and other inhalants may enhance AgE release and thereby aggravate allergic symptoms. Detailed comparison of the allergenic activity of AgE and of 16-min and 4-day ragweed extracts in 38 ragweed-sensitive subjects suggested that allergens other than AgE were together more important than AgE in causing ragweed allergy in most patients, although large patient-to-patient differences in relative response were observed. Our data emphasize the need to reevaluate materials used in both diagnosis and treatment of ragweed allergy. The importance of AgE relative to other ragweed pollen components with respect to induction of allergic symptomatology deserves to be placed in a more balanced perspective.
Journal Article•
TL;DR: The results demonstrate that the complex binding kinetics of these high-affinity racemic radioligands are not due to receptor state transitions but rather to simultaneous binding of both isomers.
Abstract: Recent studies of agonist and antagonist binding to the beta -adrenergic receptor and to other receptors have established the notion of agonist specific binding properties unshared by antagonists and reflecting the activation of the effector. However, previous reports on the dissociation kinetics of the widely used high-affinity beta -adrenergic antagonist (±)-[ 125 I]hydroxybenzylpindolol (HYP) have indicated complex binding kinetics which led to the proposal of a receptor isomerization model involving antagonist promoted transitions. We report here that the binding properties of two high-affinity beta -adrenergic antagonists can be fully explained by their racemic nature. (a) Binding data for the association and the dissociation kinetics of (±)-[ 125 I]HYP to frog erythrocyte membranes can be adequately fitted by computer modeling assuming different rate constants for each enantiomer. (b) In contrast, purified (+)-[ 125 I]HYP shows only uniphasic fast-dissociation kinetics. (c) Similarly, the antagonists (-)-[ 3 H]carazolol and (±)-[ 3 H]carazolol show uniphasic slow-dissociation kinetics and biphasic dissociation kinetics, respectively. These results demonstrate that the complex binding kinetics of these high-affinity racemic radioligands are not due to receptor state transitions but rather to simultaneous binding of both isomers.