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1.
Acta Endocrinol (Buchar) ; 12(4): 469-474, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-31149134

RESUMO

There is limited information on the long-term natural history of adrenal function in adrenal hemorrhage following sepsis. The 19-year history of a patient is described who suffered adrenal hemorrhage during pneumococcal sepsis. Adrenal reserve using Cosyntropin testing with the 250 mcg dose was evaluated at seven time points during this interval, and a close observation of the patient enabled clinical correlation with adrenal status. The cosyntropin testing showed a 60 minute cortisol level post-hemorrhage of: 303.4 nmol/L (11.0 mcg/dL), one month; 656.6 nmol/L (23.8 mcg/dL), 1 year 10 months; and 714.5 nmol/L (25.9 mcg/dL), 19 years. Over the years the patient experienced hypoadrenal symptoms requiring both hydrocortisone and fludrocortisone until her adrenal function consistently demonstrated a 60 minute cortisol level of ~ 717.3 nmol/L (26 mcg/dL). Adrenal calcifications were visualized by ultrasound imaging and ultimately resolved. In conclusion, the patient's hypothalamic-pituitary-adrenal system appeared to have ultimately restored normal basal adrenal function 19 years after the initial hemorrhage, and the dynamic cosyntropin data indicate that normal adrenal function should not be assumed with a 60 minute cortisol level of 496.6 - 551.8 nmol/L (18 - 20 mcg/dL). Finally, mineralocorticoid as well as glucocorticoid may be important for improved mental acuity in primary hypoadrenalism.

2.
J Clin Invest ; 85(1): 93-100, 1990 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2153155

RESUMO

Generalized thyroid hormone resistance (GTHR) is a disorder of thyroid hormone action that we have previously shown to be tightly linked to one of the two thyroid hormone receptor genes, c-erbA beta, in a single kindred, A. We now show that in two other kindreds, B and D, with differing phenotypes, there is also linkage between c-erbA beta and GTHR. The combined maximum logarithm of the odds score for all three kindreds at a recombination fraction of 0 was 5.77. In vivo studies had shown a triiodothyronine (T3)-binding affinity abnormality in nuclear receptors of kindred A, and we therefore investigated the defect in c-erbA beta in this kindred by sequencing a major portion of the T3-binding domain in the 3'-region of fibroblast c-erbA beta cDNA and leukocyte c-erbA beta genomic DNA. A base substitution, cytosine to adenine, was found at cDNA position 1643 which altered the proline codon at position 448 to a histidine. By allelic-specific hybridization, this base substitution was found in only one allele of seven affected members, and not found in 10 unaffected members of kindred A, as expected for a dominant disease. Also, this altered base was not found in kindreds B or D, or in 92 random c-erbA beta alleles. These results and the fact that the mutation is predicted to alter the secondary structure of the crucial T3-binding domain of the c-erbA beta receptor suggest this mutation is an excellent candidate for the genetic cause of GTHR in kindred A. Different mutations in the c-erbA beta gene are likely responsible for the variant phenotypes of thyroid hormone resistance in kindreds B and D.


Assuntos
Mutação , Proteínas Proto-Oncogênicas/genética , Receptores dos Hormônios Tireóideos/genética , Doenças da Glândula Tireoide/genética , Hormônios Tireóideos/uso terapêutico , Alelos , Sequência de Bases , DNA/genética , Resistência a Medicamentos/genética , Feminino , Ligação Genética , Humanos , Masculino , Dados de Sequência Molecular , Hibridização de Ácido Nucleico , Linhagem , Fenótipo , Proteínas Tirosina Quinases/genética , Proto-Oncogenes , Doenças da Glândula Tireoide/tratamento farmacológico
3.
Mol Endocrinol ; 2(7): 619-26, 1988 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-3412327

RESUMO

Malic enzyme catalyzes the NADP-dependent oxidative decarboxylation of malate to pyruvate and carbon dioxide and is involved in lipogenesis. We have investigated the effect of thyroid hormone on the chromatin structure of the malic enzyme gene in rat liver. Hypersensitivity to DNase I in the immediate 5'-flanking region was altered by T3. T3 stimulation induced hypersensitive sites at -310 base pairs (bp) and -50 bp whereas a hypersensitive site at -170 bp was thyroid hormone independent. Hypersensitive sites identified in the 3'-flanking region showed no change with T3 stimulation. We further characterized expression of the malic enzyme gene as a function of thyroidal state by localizing malic enzyme mRNA in hepatocytes using in situ hybridization histochemistry. In hypothyroid and euthyroid states, two populations of hepatocytes were seen, some with malic enzyme message and others with no detectable message. These differences in malic enzyme gene expression were most evident between groups or regions of hepatocytes. After 10 days of thyroid hormone treatment all hepatocytes demonstrated malic enzyme message. The hypersensitivity results confirm that thyroid hormone stimulation of malic enzyme synthesis occurs in part at the level of transcription, and localization of malic enzyme gene expression suggests this stimulation is accompanied by recruitment of hepatocytes. Hepatocytes may be heterogeneous in their ability to respond to thyroid hormone.


Assuntos
Cromatina/análise , Fígado/citologia , Malato Desidrogenase/genética , Tri-Iodotironina/farmacologia , Animais , Fenômenos Químicos , Química , Cromatina/efeitos dos fármacos , Cromatina/ultraestrutura , DNA/efeitos dos fármacos , Desoxirribonuclease I/farmacologia , Feminino , Histocitoquímica , Fígado/enzimologia , Malato Desidrogenase/biossíntese , Hibridização de Ácido Nucleico , RNA Mensageiro/análise , Ratos , Ratos Endogâmicos , Transcrição Gênica/efeitos dos fármacos
4.
Mol Endocrinol ; 2(12): 1217-20, 1988 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2905763

RESUMO

Multiple cDNAs belonging to the c-erbA gene family encode proteins that bind T3 with high affinity. However, the biological functions of these multiple thyroid hormone receptors have not yet been clarified. Generalized thyroid hormone resistance (GTHR) refers to a human syndrome characterized by tissue refractoriness to the action of thyroid hormones; several studies have suggested quantitative or qualitative defects in T3 binding to nuclear receptors in certain kindreds. To investigate the biological functions of the c-erbA genes, c-erbA alpha and c-erbA beta, we tested the hypothesis that an abnormal c-erbA gene product is present in GTHR by examining these genes in members of one kindred. Restriction enzyme analysis failed to identify an abnormal pattern in affected individuals suggesting no rearrangements or large deletions. However, we demonstrated that the gene conferring the GTHR phenotype is tightly linked to the c-erbA beta locus on chromosome 3. This linkage strongly suggests that the c-erbA beta gene is important in man as a thyroid hormone receptor and identifies a putative c-erbA beta mutant phenotype with central nervous system, pituitary, liver, metabolic, and growth abnormalities.


Assuntos
Ligação Genética , Proteínas Proto-Oncogênicas/genética , Doenças da Glândula Tireoide/genética , Tri-Iodotironina/metabolismo , Resistência a Medicamentos , Humanos , Linhagem , Polimorfismo de Fragmento de Restrição , Receptores dos Hormônios Tireóideos , Síndrome/genética , Doenças da Glândula Tireoide/metabolismo
5.
Mol Endocrinol ; 5(3): 327-35, 1991 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-1653889

RESUMO

Different point mutations have been identified in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene that are associated with variant phenotypes of generalized thyroid hormone resistance (GTHR). In most cases of GTHR, heterozygotes are affected; a single mutant allele results in the inhibition of the function of normal thyroid hormone receptors. We report here a novel genetic abnormality, a 3-basepair (bp) deletion in the T3-binding domain of the beta-receptor in a kindred, S, with GTHR. One patient, S1, was the product of a consanguineous union of two heterozygotes and was homozygous for this defect. Heterozygotes from kindred S harbored a CAC deletion at nucleotides 1295-1297, which resulted in the deduced loss of amino acid residue threonine at codon 332, and they displayed elevated free T4 levels and inappropriately normal TSH levels characteristic of other kindreds with GTHR. However, patient S1, who had two mutant alleles, had markedly elevated TSH and free T4 levels and displayed profound abnormalities in brain development and linear growth. A fibroblast c-erbA beta cDNA extending from codon 175 to stop codon 457 was cloned from patient S1, sequenced, and used to create a full-length mutant cDNA. The kindred S mutant receptor was synthesized in vitro and did not bind T3. This mutant receptor did bind with similar avidity as the wild-type human beta-receptor to thyroid hormone response elements of the human TSH beta (-12 to 43 bp) and rat GH (-188 to -160 bp) genes. Kindred S showed the effect in man of heterozygous and homozygous expression of a dominant negative form of c-erbA beta.


Assuntos
Mutação , Proteínas Proto-Oncogênicas/genética , Receptores dos Hormônios Tireóideos/genética , Hormônios Tireóideos/farmacologia , Alelos , Composição de Bases , Sequência de Bases , DNA/química , DNA/metabolismo , Resistência a Medicamentos/genética , Ligação Genética , Homozigoto , Humanos , Técnicas In Vitro , Dados de Sequência Molecular , Fenótipo , Receptores dos Hormônios Tireóideos/efeitos dos fármacos , Receptores dos Hormônios Tireóideos/metabolismo , Tiroxina/farmacologia , Tri-Iodotironina/farmacologia
6.
Mol Endocrinol ; 8(7): 841-51, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7984146

RESUMO

Syndromes of resistance to thyroid hormones are caused by mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene. The S receptor (deletion of THR332) is a potent dominant negative protein cloned from a kindred with generalized resistance to thyroid hormones. The G-H receptor (ARG311HIS) has compromised dominant negative function and was found in both normal individuals and in a patient with severe pituitary resistance to thyroid hormones. We have investigated the mechanism responsible for the difference in receptor phenotypes by analyzing the binding of S and G-H receptors to thyroid hormone response elements with electrophoretic mobility shift analysis. Wild-type human c-erbA beta 1 (WT), S, and G-H receptors were synthesized in reticulocyte lysate, reacted with a thyroid hormone response element consisting of a direct repeat with 4 base pairs (DR+4; AGGTCA CAGG AGGTCA), and the products analyzed by gel shift. G-H receptor homodimerization was greatly impaired; G-H formed predominantly monomeric complex compared with monomeric and homodimeric WT complexes. The G-H receptor was able to form heterodimeric complexes with cellular thyroid hormone receptor auxiliary protein (TRAP) factors including the human retinoid X receptor-alpha. When TRAP was limiting, the levels of G-H heterodimeric complex were 2- to 3-fold reduced compared with WT receptor. In contrast to the WT and G-H receptors, the S receptor formed almost exclusively homodimeric complex with DR+4; the approximate ratio of S:WT:G-H homodimeric complexes at equivalent concentrations of receptors was 60:20:1. A measurable increase (1.2- to 2.6-fold) in heterodimeric complex formation was observed with the S receptor relative to WT when TRAP was at limiting concentration. As reported previously by others, thyroid hormone significantly reduced the WT homodimeric complex with DR+4. There was no effect on the S homodimeric complex. Finally, the WT, S, and G-H receptors formed different complexes with the element consisting of an inverted repeat with 5 base pairs (IR+5; AGGTCA ACAGT TGACCT) and the IR element (AGGTCA TGACCT), which were differently regulated by thyroid hormone. The S receptor bound as a homodimer with IR+5, whereas the WT receptor bound as a homodimer only with thyroid hormone. No homodimeric complex formed with IR+5 and the G-H receptor. Qualitatively similar results were observed with the IR element. We conclude that the ARG311HIS mutation severely perturbs the homodimerization and, to a much less degree, heterodimerization functions of the c-erbA beta 1 receptor. Furthermore, the THR332 deletion mutation augments homodimerization of the c-erbA beta 1 receptor. These results indicate that different mutations in the c-erbA beta 1 thyroid hormone receptor have divergently affected dimerization activities which seem to influence the level of dominant negative activity in man.


Assuntos
Receptores dos Hormônios Tireóideos/genética , Tri-Iodotironina/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Chlorocebus aethiops , DNA/metabolismo , Genes Dominantes , Humanos , Dados de Sequência Molecular , Mutação Puntual , Conformação Proteica , Estrutura Secundária de Proteína , Receptores dos Hormônios Tireóideos/química , Receptores dos Hormônios Tireóideos/metabolismo
7.
Mol Endocrinol ; 6(2): 248-58, 1992 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1569968

RESUMO

Mutations in the gene encoding the human beta 1 T3 receptor (hTR beta 1) have been associated with generalized resistance to thyroid hormone (GRTH). We measured the T3-binding affinity and transcriptional regulatory capacity of the mutant hTR beta 1 from four unrelated kindreds with GRTH. These mutations are contained in different functional regions of the ligand-binding domain. The T3 affinity of the mutant receptors correlated well with the degree of impairment of their trans-activating function in a transient cotransfection system in HeLa cells; two mutant receptors with undetectable ligand affinity showed no transcriptional activity, whereas the two other mutants characterized by a 2- and 5-fold reduction in T3 affinity required 5- and 15-fold higher T3 concentrations for half-maximal activity in the cotransfection assay, respectively. All of the mutant hTR beta 1s were able to inhibit the function of transfected normal hTR beta 1 and endogenous retinoic acid receptor in activating a palindromic positive T3 response element (TRE). In the partially functional mutants this dominant negative effect could be completely reversed by increased T3 concentrations. The dominant negative potency did not depend on the type of TRE used; mutant hTR beta 1s were able to inhibit normal receptor function to the same degree on a dimer-permissive palindromic TRE as on a nondimer-permissive inverted repeat of two identical half-sites separated by five spacer bases. However, the dominant negative potency was dependent on the absolute amount of receptor expression vector transfected. The expression of normal and mutant hTR beta 1 was assessed by immunocytochemistry. The hTR beta 1 protein levels in HeLa cells paralleled the amount of transfected expression vector. Moreover, all the mutant receptors were properly expressed in the nuclei of the transfected cells. These data suggest that different mutations in the ligand-binding domain of the human hTR beta 1 result in a variable degree of functional impairment, which may partially explain the phenotypic differences between kindreds with GRTH. Our findings suggest that competition for binding to the TRE and possibly the binding of limiting accessory factors may be more important in mediating the dominant negative effect than the formation of normal/mutant T3 receptor dimers.


Assuntos
Receptores dos Hormônios Tireóideos/metabolismo , Doenças da Glândula Tireoide/metabolismo , Transcrição Gênica , Tri-Iodotironina/metabolismo , Sequência de Bases , Células HeLa , Humanos , Dados de Sequência Molecular , Mutação , Receptores dos Hormônios Tireóideos/genética , Doenças da Glândula Tireoide/genética , Transfecção
8.
Mol Endocrinol ; 2(1): 32-9, 1988 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-3398841

RESUMO

A 17 kilobase pair fragment of DNA containing the human TSH (hTSH) beta-subunit gene was isolated from a human leukocyte genomic library. Using a 621 base pair human CG alpha-subunit cDNA and a 2.0 kilobase pair genomic fragment of hTSH beta containing both coding exons, we constructed hCG alpha and hTSH beta expression vectors containing either the early promoter of simian virus 40 or the promoters of adeno-associated virus. Cotransfection of two adeno-associated virus vectors, each containing one subunit of hTSH, together with a plasmid containing the adenovirus VA RNA genes produced hTSH as well as free human alpha- and TSH beta-subunits in an adenovirus transformed human embryonal kidney cell line (293). The levels of protein expression in this system were 10- to 100-fold greater than that found in a simian virus transformed monkey kidney cell line (COS) using vectors containing the early promoter of simian virus 40. The hTSH synthesized in 293 cells was glycosylated as indicated by complete binding to concanavalin A-Sepharose but was larger in apparent molecular weight than a standard hTSH preparation on gel chromatography suggesting an altered glycosylation pattern. However, it was immunologically and biologically indistinguishable from two pituitary hTSH standards in an immunoradiometric and in vitro iodide trapping assay, respectively.


Assuntos
Clonagem Molecular , Genes , Tireotropina/genética , Transcrição Gênica , Transfecção , Animais , Linhagem Celular , Humanos , RNA Mensageiro/genética
9.
Endocrinology ; 138(3): 1215-23, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9048629

RESUMO

Previous studies have demonstrated that thyroid hormone (T3) stimulates insulin-responsive glucose transporter (GLUT4) transcription and protein expression in rat skeletal muscle. The aim of the present study was to define a putative thyroid hormone response element (TRE) within the rat GLUT4 promoter and thus perhaps determine whether T3 acts directly to augment skeletal muscle GLUT4 transcription. To this end, electrophoretic mobility shift analyses were performed to analyze thyroid hormone receptor (TR) binding to a previously characterized 281-bp T3-responsive region of the rat GLUT4 promoter. Indeed, within this region, a TR-binding site of the standard DR + 4 TRE variety was located between bases -457/ -426 and was shown to posses a specific affinity for in vitro translated TRs. Interestingly, however, the GLUT4 TR-binding site demonstrated a significantly lower affinity compared to a consensus DR + 4 TRE, and only bound TRs appreciatively in the form of high affinity heterodimers, in this case with the cis-retinoic acid receptor. In conclusion, these data demonstrated the presence of a specific TR-binding site within a T3-responsive region of the rat GLUT4 promoter and thus support the supposition that thyroid hormone acts directly to stimulate GLUT4 transcription in rat skeletal muscle. Moreover, characterization of a novel TR-binding site with low affinity suggests an additional mechanism by which the intrinsic activity and responsiveness of thyroid hormone regulated genes may be modulated.


Assuntos
Proteínas de Transporte de Monossacarídeos/genética , Proteínas de Transporte de Monossacarídeos/metabolismo , Proteínas Musculares , Regiões Promotoras Genéticas/genética , Receptores dos Hormônios Tireóideos/metabolismo , Animais , Sequência de Bases , Sítios de Ligação , Ligação Competitiva , Eletroforese , Transportador de Glucose Tipo 4 , Humanos , Dados de Sequência Molecular , Proteínas de Transporte de Monossacarídeos/efeitos dos fármacos , Ratos , Tri-Iodotironina/farmacologia
10.
Endocrinology ; 140(2): 897-902, 1999 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9927321

RESUMO

The heart has been recognized as a major target of thyroid hormone action. Our study investigates both the regulation of cardiac-specific genes and contractile behavior of the heart in the presence of a mutant thyroid hormone receptor beta1 (T3Rbeta1-delta337T) derived from the S kindred. The mutant receptor was originally identified in a patient with generalized resistance to thyroid hormone. Cardiac expression of the mutant receptor was achieved by a transgenic approach in mice. As the genes for myosin heavy chains (MHC alpha and MHC beta) and the cardiac sarcoplasmic reticulum Ca2+ adenosine triphosphatase (SERCA2) are known to be regulated by T3, their cardiac expression was analyzed. The messenger RNA levels for MHC alpha and SERCA2 were markedly down-regulated, MHC beta messenger RNA was up-regulated. Although T3 levels were normal in these animals, this pattern of cardiac gene expression mimics a hypothyroid phenotype. Cardiac muscle contraction was significantly prolonged in papillary muscles from transgenic mice. The electrocardiogram of transgenic mice showed a substantial prolongation of the QRS interval. Changes in cardiac gene expression, cardiac muscle contractility, and electrocardiogram are compatible with a hypothyroid cardiac phenotype despite normal T3 levels, indicating a dominant negative effect of the T3Rbeta mutant.


Assuntos
Coração/fisiologia , Mutação/fisiologia , Receptores dos Hormônios Tireóideos/genética , Tri-Iodotironina/fisiologia , Animais , ATPases Transportadoras de Cálcio/genética , Resistência a Medicamentos/genética , Eletrocardiografia , Feminino , Dosagem de Genes , Expressão Gênica/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos/genética , Contração Miocárdica/fisiologia , Cadeias Pesadas de Miosina/genética , Fenótipo , Retículo Sarcoplasmático/enzimologia
11.
J Clin Endocrinol Metab ; 73(5): 990-4, 1991 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-1682340

RESUMO

Generalized resistance to thyroid hormones (GRTH) commonly results from mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene. We have reported on a novel deletion mutation in c-erbA beta in a kindred, S, with GRTH. One patient from this kindred was the product of a consanguineous union from two affected members and was homozygous for the beta-receptor defect. This patient at 3.5 weeks of age had unprecedented elevations of TSH, free T4, and free T3 (TSH, 389 mU/L; free T4, 330.8 pmol/L; free T3, 82,719 fmol/L). He displayed a complex mixture of tissue-specific hyperthyroidism and hypothyroidism. He had delayed growth (height age, 1 3/12 yr at chronological age 2 9/12 yr) and skeletal maturation (bone age, 4 months), and developmental delay (developmental age, 8 months), but he was quite tachycardic. The homozygous patient of kindred S is markedly different from a recently reported patient with no c-erbA beta-receptor. This difference indicates that a dominant negative form of c-erbA beta in man can inhibit at least some thyroid hormone action mediated by the c-erbA alpha-receptors.


Assuntos
Homozigoto , Mutação , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Receptores dos Hormônios Tireóideos/genética , Doenças da Glândula Tireoide/genética , Adolescente , Adulto , Células Cultivadas , Pré-Escolar , Deleção Cromossômica , DNA/genética , DNA/isolamento & purificação , Enzimas de Restrição do DNA , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Linhagem , Polimorfismo de Fragmento de Restrição , Cintilografia , Pele/metabolismo , Doenças da Glândula Tireoide/diagnóstico , Doenças da Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/diagnóstico por imagem , Tiroxina/sangue , Tri-Iodotironina/sangue
12.
J Clin Endocrinol Metab ; 79(2): 435-40, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8045959

RESUMO

We have previously demonstrated weekly iv insulin-like growth factor-I (IGF-I; 500 micrograms/kg) bolus therapy to be effective in inducing sustained insulin sensitivity in a patient with type I diabetes mellitus and massive insulin resistance. The present study was undertaken to determine the efficacy of daily sc IGF-I in the treatment of two severely insulin-resistant type I diabetic patients (requiring in excess of 3500 U insulin/day) compared to weekly iv IGF-I therapy. Prolonged insulin sensitivity was achieved in both patients after weekly 500 micrograms/kg iv bolus infusions of IGF-I, with sc insulin requirements falling to approximately 1 U/kg.day. Smaller iv doses (250 micrograms/kg) of IGF-I were ineffective in acutely lowering serum glucose or inducing sustained insulin sensitivity. However, even this smaller IGF-I dose resulted in acute symptomatic hypophosphatemia, which could be prevented by coadministration of potassium phosphate. With sc administered IGF-I (up to 10 mg twice daily), insulin appeared to control patient glucose concentrations, but severe insulin resistance returned within 72 h of discontinuing IGF-I therapy. IGF-I dosing was decreased to the lowest concentration that maintained euglycemia (7.5 mg in the morning and 2.5 mg in the evening). However, severe arthropathy in both patients and neurological symptoms including multiple cranial nerve palsies in one patient were associated with chronic therapy. We conclude that both iv and sc administered IGF-I can precipitate acute symptomatic hypophosphatemia. Chronic low dose sc therapy may be associated with severe neuropathy and arthropathy, and does not induce the sustained insulin sensitivity associated with high dose intermittent bolus IGF-I therapy.


Assuntos
Diabetes Mellitus Tipo 1/tratamento farmacológico , Resistência à Insulina , Fator de Crescimento Insulin-Like I/administração & dosagem , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Adolescente , Adulto , Glicemia/metabolismo , Cardiomiopatias/prevenção & controle , Diabetes Mellitus Tipo 1/metabolismo , Feminino , Glucose/metabolismo , Humanos , Hipofosfatemia/induzido quimicamente , Infusões Intravenosas , Injeções Subcutâneas , Insulina/farmacologia , Fator de Crescimento Insulin-Like I/efeitos adversos , Fator de Crescimento Insulin-Like I/uso terapêutico , Artropatias/induzido quimicamente , Doenças do Sistema Nervoso/induzido quimicamente
13.
J Clin Endocrinol Metab ; 74(5): 1164-70, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1314846

RESUMO

Generalized resistance to thyroid hormones results from diverse mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor, and different kindreds have variable phenotypes. However, the T3-binding affinities of these mutant receptors studied in vitro have all been severely reduced compared to wild type. We report here a new kindred, CL, with a mutation further upstream than previously reported, a guanine to adenine base substitution at nucleotide 1244 in codon 315 changing an arginine to histidine. This base substitution was the only one found in codons 90-456 of genomic sequence and was formally shown to be a mutation by screening 51 random individuals. The kindred CL receptor complementary DNA was recreated, and the mutant receptor synthesized with rabbit reticulocyte lysate had a T3-binding affinity of 2.4 +/- 0.9 x 10(10) M-1 compared to the wild-type human placental receptor affinity of 5.2 +/- 1.6 x 10(10) M-1. Affected members of this kindred appeared clinically to have a relatively mild degree of resistance with mean total thyroxine of only 192 +/- 24 nmol/L and inappropriately normal TSH levels. Kindred CL is an example of mild generalized resistance to thyroid hormones correlated with a mutation in the beta-receptor that resulted in only a modest deficiency in T3-binding activity.


Assuntos
Códon , Proteínas Proto-Oncogênicas/genética , Receptores dos Hormônios Tireóideos/genética , Hormônios Tireóideos/farmacologia , Tri-Iodotironina/metabolismo , Adulto , Sequência de Bases , Criança , Pré-Escolar , Resistência a Medicamentos , Humanos , Pessoa de Meia-Idade , Dados de Sequência Molecular , Mutação , Receptores dos Hormônios Tireóideos/metabolismo
14.
J Clin Endocrinol Metab ; 72(1): 32-8, 1991 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-1846005

RESUMO

Two different mutations in the c-erbA beta thyroid hormone receptor have recently been reported as genetic abnormalities responsible for the syndrome of generalized thyroid hormone resistance (GTHR). We have now found in a third kindred, D, in which GTHR is inherited as a dominant disease, a new point mutation in the T3-binding domain of c-erbA beta. A guanine to cytosine base substitution at nucleotide position 1305, which altered codon-335 from glutamine (CAG) to histidine (CAC), was found in one allele of 10 affected members and was not found in 6 unaffected members. This C-1305 sequence was not present in 106 random alleles, indicating that it was a mutation in c-erbA beta, and it was tightly linked to GTHR in kindred D, with a maximum logarithm of the odds score of 4.19 at a recombination fraction of 0. The tight linkage result confirms that GTHR maps to the c-erbA beta locus in multiple kindreds. In view of the tight linkage between the C-1305 mutation and GTHR, and that this mutation is a nonconservative alteration in a crucial region of the T3-binding domain, it is probably the genetic defect in kindred D responsible for GTHR. The kindred D receptor appears to result in a different phenotype of tissue resistance compared to the previously reported kindred. A receptor with a mutation in the carboxy-terminus of c-erbA beta.


Assuntos
Doenças do Sistema Endócrino/genética , Mutação , Proteínas Proto-Oncogênicas/genética , Receptores dos Hormônios Tireóideos/genética , Hormônios Tireóideos/farmacologia , Tri-Iodotironina/metabolismo , Sequência de Bases , Sítios de Ligação , Citosina , Desoxirribonucleases de Sítio Específico do Tipo II , Resistência a Medicamentos/genética , Feminino , Humanos , Escore Lod , Masculino , Dados de Sequência Molecular , Linhagem , Hipófise/efeitos dos fármacos , Síndrome , Hormônios Tireóideos/sangue , Hormônio Liberador de Tireotropina
15.
J Clin Endocrinol Metab ; 77(4): 969-75, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8408473

RESUMO

Mutations in the T3-binding domain of the thyroid hormone receptor gene c-erbA beta result in dominant negative proteins and thyroid hormone resistance syndromes. Variable clinical manifestations of resistance to thyroid hormones have been reported, including short stature and neuropsychological abnormalities. The molecular bases for heterogeneity of phenotype among and within kindreds have not been fully elucidated. Recent investigations have considered differential expression of mutant and wild-type beta 1-receptor alleles and the regulation thereof as a mechanism to explain differential sensitivity to thyroid hormones. We used reverse transcription-competitive polymerase chain reaction (PCR) to measure c-erbA beta 1, c-erbA alpha 1, and c-erbA alpha 2 mRNAs in skin fibroblasts cultured from normal subjects, heterozygotes, and a severely affected homozygous mutant of kindred S. The homozygous mutant of kindred S had severe growth and mental retardation. After reverse transcription with primers specific for each of the c-erbA mRNAs, first strand cDNAs were amplified by PCR using subtype-specific amplimers. Primer design allowed simultaneous detection of wild-type and mutant messages in heterozygous fibroblasts and showed an approximately 1:1 ratio of these mRNAs in three patients. Inclusion of competitive standard cDNAs of known concentration in the PCR reactions allowed quantitation of the absolute levels of the beta 1-, alpha 1-, and alpha 2 mRNAs by comparison of products on ethidium bromide-stained agarose gels. These studies showed no effect of the presence of the mutant beta 1-allele, as fibroblast RNA from normal subjects, heterozygotes, and the homozygote gave values of 56-184, 2.8-12, and 23-40 attomol/5 micrograms total RNA for beta 1-, alpha 1-, and alpha 2 mRNAs, respectively. We conclude that these sensitive methods allow the detection of molecular species present at levels as low as 10 molecules/cell, and that this potent dominant negative receptor does not disrupt c-erbA expression at the level of mRNA. The neuropsychological sequelae of the kindred S mutation are not due to relative overexpression of the mutant allele.


Assuntos
Fibroblastos/metabolismo , RNA Mensageiro/biossíntese , Receptores dos Hormônios Tireóideos/biossíntese , Doenças da Glândula Tireoide/genética , Alelos , Sequência de Bases , Primers do DNA/química , Expressão Gênica , Heterozigoto , Humanos , Dados de Sequência Molecular , Mutação , Reação em Cadeia da Polimerase , Receptores dos Hormônios Tireóideos/genética , Doenças da Glândula Tireoide/metabolismo , Transcrição Gênica
16.
Fertil Steril ; 39(3): 304-9, 1983 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-6825865

RESUMO

Cervicovaginal fluid that accumulates in the upper vagina and posterior fornix can be quantitatively correlated with the presumably fertile and infertile phases of the menstrual cycle. With a newly developed Volumetric Vaginal Aspirator that women self-administer, cervicovaginal fluid can be sampled on a daily basis and the sample volume or sample weight recorded. In a total of 18 cycles from 7 different subjects there was a striking 3- to 30-fold increase in sample volume or sample weight above early follicular phase levels that preceded the shift in basal body temperature (BBT) at midcycle. The maximum of sample volume or sample weight near midcycle was defined as "Volume Peak" or "Weight Peak." The magnitude of the Volume Peak or Weight Peak varied in the individual subjects and was between 400 and 1500 microliters or mg. The Volume Peak or Weight Peak generally occurred 1 to 2 days before or on the day of presumptive ovulation. With the BBT shift to luteal phase levels, the sample volume or sample weight sharply declined to early follicular phase levels. The results suggest that changes in sample volume or sample weight of cervicovaginal fluid measured with the self-applicable Volumetric Vaginal Aspirator can be used as an objective basis for approaches to natural family planning and for the assessment of optimal conditions for conception.


Assuntos
Muco do Colo Uterino , Fase Folicular , Menstruação , Adulto , Temperatura Corporal , Serviços de Planejamento Familiar , Feminino , Humanos , Detecção da Ovulação/métodos , Autocuidado
17.
Fertil Steril ; 67(4): 636-40, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9093186

RESUMO

OBJECTIVE: To measure cystic fibrosis transmembrane regulator (CFTR) gene expression in cervical secretions during the menstrual cycle. DESIGN: Prospective, descriptive clinical study. PATIENTS: Thirteen healthy women with ovulatory menstrual cycles. INTERVENTIONS: Endocervical cells and secretions were obtained by cytobrushings during the midfollicular, midcycle, and luteal phases. The cells were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) for CFTR and glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene expression. MAIN OUTCOME MEASURES: Detection of CFTR gene expression and a quantitative comparison of the levels of CFTR to GAPDH gene expression. RESULTS: All endocervical samples exhibited some degree of CFTR gene expression throughout the menstrual cycle; however, the levels of expression were variable. Cystic fibrosis transmembrane regulator gene expression did not correlate with E2 or P levels. CONCLUSION: The production of copious cervical secretions at the time of ovulation in part may be because of the transport of sodium and water across endocervical cell membranes as a result of E2-stimulated CFTR mRNA and protein. Although cervical mucus becomes thick and scant during the luteal phase, CFTR gene expression is present in these secretions.


Assuntos
Colo do Útero/química , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Expressão Gênica/genética , Ciclo Menstrual/genética , RNA/análise , Adulto , Colo do Útero/citologia , Regulador de Condutância Transmembrana em Fibrose Cística/análise , Primers do DNA/química , Eletroforese em Gel de Ágar , Estrogênios/sangue , Feminino , Regulação Enzimológica da Expressão Gênica , Gliceraldeído-3-Fosfato Desidrogenases/análise , Gliceraldeído-3-Fosfato Desidrogenases/genética , Humanos , Ciclo Menstrual/metabolismo , Reação em Cadeia da Polimerase , Progesterona/sangue , Estudos Prospectivos , RNA/genética
18.
Thyroid ; 1(4): 361-7, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1668726

RESUMO

The genetic basis of generalized resistance to thyroid hormones (GRTH) is now well understood. In the majority of patients, diverse mutations in the T3-binding domain of the c-erbA beta thyroid hormone receptor gene result in variable clinical presentations. These mutations are dominant negative in that the mutant receptors inhibit the function of normal beta-receptor (from one allele) and normal alpha-receptor (from two alleles). Several mutant c-erbA beta receptors have been cloned and synthesized in vitro; these receptors display a wide range of T3-binding affinities from only a two-fold reduction to no detectable T3-binding activity. Recent transfection studies with T3-regulated reporter genes and these mutant receptors have confirmed the dominant negative function of the mutations in patients with GRTH. Two unique patients, the Refetoff and Bercu patients, display the clinical (phenotypic) results of total absence of beta-receptor and homozygous expression of a dominant negative mutant beta-receptor, respectively. Further clinical and molecular studies of GRTH should lead to greater insights of the nature of thyroid hormone action in man.


Assuntos
Hormônios Tireóideos/metabolismo , Sequência de Bases , Criança , Mapeamento Cromossômico , Humanos , Recém-Nascido , Dados de Sequência Molecular , Mutação , Proteínas Proto-Oncogênicas/genética , Receptores dos Hormônios Tireóideos/genética , Tireotropina/metabolismo , Tri-Iodotironina/metabolismo
19.
Thyroid ; 6(3): 189-94, 1996 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8837325

RESUMO

Thyroid hormone resistance syndromes, which result from heterozygous mutations in the beta 1 thyroid hormone receptor gene, are sometimes associated with adult short stature, but more frequently with delayed bone age (BA). Primary fibroblasts from young children with both delayed BA and short stature from a kindred A have been reported to overexpress the mutant allele. However, in fibroblasts from affected members of two different kindreds with thyroid hormone resistance, S and Mf, there were equal levels of mutant and wild-type beta 1 mRNA. We investigated the ontogeny of differential allelic expression using competitive reverse transcription with PCR (RT-PCR) to measure relative mRNA levels for beta 1 and S receptor in very young affected children of kindred S. Total RNA was prepared from fibroblasts of two patients (ages 3-0.5/12 and 1-4/12 years) with delayed BA but normal growth curves. Using PCR amplimers that create an Mlu-1 site in wild-type but not mutant cDNA products from the competitive RT, we quantitated mRNA levels. Normal beta 1 mRNA was present at nearly twice the level of the mutant mRNA in cells from these patients. Relative expression of the c-erbA beta alleles thus appeared to be increased during this period of somatic growth. The relative overexpression of the normal allele potentially counteracted the potent dominant negative effect of the S receptor during early childhood ameliorating a deleterious effect on linear growth.


Assuntos
Fibroblastos/química , Heterozigoto , Mutação , RNA Mensageiro/análise , Receptores dos Hormônios Tireóideos/genética , Síndrome da Resistência aos Hormônios Tireóideos/genética , Determinação da Idade pelo Esqueleto , Estatura , Desenvolvimento Ósseo , Células Cultivadas , Pré-Escolar , Humanos , Lactente , Linhagem , Reação em Cadeia da Polimerase
20.
J Reprod Med ; 34(4): 292-4, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2715991

RESUMO

Immunoglobulin levels in cervicovaginal secretions during the menstrual cycle have not been well characterized biochemically. We determined the IgG and IgA concentrations in vaginal fluid obtained by patient self-sampling with an Ovu-Trac aspirator. Vaginal fluid IgG levels were less than 1-270 mg/dL. On the average the levels of IgG were relatively high after menstruation, declined during the ovulatory phase and remained relatively low during most of the luteal phase. The IgA levels were less than 10 mg/dL, and many samples contained IgA at our assay's lower limits of detection (microradial immunodiffusion). The preovulatory and luteal phase levels of IgG and IgA in vaginal fluid were generally lower than those reported for cervical mucus, but the ovulatory phase IgG and IgA composition was comparable between vaginal fluid and cervical mucus.


PIP: The IgG and IgA content of vaginal fluid obtained was determined by daily sampling with the Ovu-Trac vaginal pipet. In addition to vaginal fluid sample volume plots, serum luteinizing hormone and progesterone levels were obtained. IgG and IgA measurements in vaginal fluid throughout the menstrual cycle are reported. A total of 12 cycles from 12 women were studied. In all 12 cycles a significant luteinizing hormone peak was observed. The progesterone levels reached significantly high levels in the 12 cycles, indicating that ovulation presumably had occurred. A peak in vaginal fluid sample volume occurred typically near the luteinizing hormone peak. The IgG and IgA concentrations of the vaginal fluid samples from the 12 cycles were determined. The IgG levels were less than 1-270 mg/dL. There was much fluctuation in vaginal fluid IgG levels throughout the cycle, but a general pattern did emerge. Vaginal fluid IgG levels were relatively high in the postmenstrual/early proliferative phase, with a steady decline to relatively low levels throughout the luteal phase. There was no direct correspondence between the volume of vaginal fluid and the IgG concentration, as seen from a comparison of the average vaginal fluid IgG concentration with the average vaginal fluid sample volume. Vaginal fluid with a low sample volume in the early preovulatory phase had relatively high levels of IgG, whereas that with a low sample volume in the luteal phase had relatively low levels of IgG. IgA in vaginal fluid was present at levels 10-fold less than those of IgG. The IgA concentrations of many of the vaginal fluid samples were near the assay's lower limit of sensitivity, making it difficult to reach any conclusions about cyclic changes. The lowest vaginal fluid IgA concentrations were observed around the middle of the luteal phase.


Assuntos
Líquidos Corporais/análise , Imunoglobulina A/análise , Imunoglobulina G/análise , Ciclo Menstrual , Vagina/fisiologia , Líquidos Corporais/imunologia , Muco do Colo Uterino/análise , Muco do Colo Uterino/imunologia , Feminino , Humanos , Hormônio Luteinizante/sangue
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