Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
J Endocrinol Invest ; 2018 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-29388053

RESUMO

AIM: Type 1 diabetes mellitus (T1D) is an autoimmune disease characterized by the progressive destruction of ß cells, mediated by the interaction between T cells and several cytokines. The pathogenesis of T1D has established its possible relationship with miRNAs. In this study, we analyze the expression profile of miR-15a and miR-16 in peripheral blood mononuclear cells (PBMCs) and their possible association with apoptosis, inflammation, or autoimmunity markers. PATIENTS AND METHODOLOGY: 38 T1D patients and 41 control subjects were recruited. mRNAs were analyzed by means of qPCR and TaqMan probes. PBMCs were treated with different concentrations of glucose (baseline, 11 and 25 mM) with or without an inflammatory stimulus as TNF-α (10 ng/ml). RESULTS: A decrease in the levels of the miR-15a expression in basal conditions is observed in T1D patients compared to healthy control subjects (relative units 0.5 vs. 1.8, p < 0.05). This change in miR-15a and miR-16 is not affected by the addition of TNF-α. No association is observed with inflammatory markers (IL-6, TNF-α, vCAM) or apoptosis (bcl2 expression). The relationship with immunological markers shows an interaction effect between miR16 and IA-2 (p < 0.03). CONCLUSION: TNF-α does not affect the expression profile of miR-15a and miR16 in PBMCs. A weak correlation is observed between miR-16 and with the autoimmunity profile (IA-2 autoantibody).

2.
J Endocrinol Invest ; 41(9): 1083-1088, 2018 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-29383679

RESUMO

AIM: Type 1 diabetes mellitus (T1D) is an autoimmune disease characterized by the progressive destruction of ß cells, mediated by the interaction between T cells and several cytokines. The pathogenesis of T1D has established its possible relationship with miRNAs. In this study, we analyze the expression profile of miR-15a and miR-16 in peripheral blood mononuclear cells (PBMCs) and their possible association with apoptosis, inflammation, or autoimmunity markers. PATIENTS AND METHODOLOGY: 38 T1D patients and 41 control subjects were recruited. mRNAs were analyzed by means of qPCR and TaqMan probes. PBMCs were treated with different concentrations of glucose (baseline, 11 and 25 mM) with or without an inflammatory stimulus as TNF-α (10 ng/ml). RESULTS: A decrease in the levels of the miR-15a expression in basal conditions is observed in T1D patients compared to healthy control subjects (relative units 0.5 vs. 1.8, p < 0.05). This change in miR-15a and miR-16 is not affected by the addition of TNF-α. No association is observed with inflammatory markers (IL-6, TNF-α, vCAM) or apoptosis (bcl2 expression). The relationship with immunological markers shows an interaction effect between miR16 and IA-2 (p < 0.03). CONCLUSION: TNF-α does not affect the expression profile of miR-15a and miR16 in PBMCs. A weak correlation is observed between miR-16 and with the autoimmunity profile (IA-2 autoantibody).


Assuntos
Apoptose/fisiologia , Autoimunidade/fisiologia , Diabetes Mellitus Tipo 1/metabolismo , Mediadores da Inflamação/metabolismo , MicroRNAs/biossíntese , Adolescente , Adulto , Apoptose/efeitos dos fármacos , Autoimunidade/efeitos dos fármacos , Biomarcadores/metabolismo , Células Cultivadas , Criança , Pré-Escolar , Chile/epidemiologia , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/imunologia , Feminino , Humanos , Leucócitos Mononucleares/efeitos dos fármacos , Leucócitos Mononucleares/imunologia , Leucócitos Mononucleares/metabolismo , Masculino , Fator de Necrose Tumoral alfa/toxicidade , Adulto Jovem
3.
Diabet Med ; 33(10): 1366-73, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-26802741

RESUMO

AIMS: To assess serum oestrogen levels and oestrogenic activity in adolescents with Type 1 diabetes compared with a healthy control group. METHODS: We conducted a cross-sectional study that evaluated adolescents with Type 1 diabetes (n = 38) and healthy adolescents (control group; n = 32). Serum oestrogens, urinary oestrogen metabolites and serum oestrogenic activity were assessed. Oestrogenic activity was evaluated in an in vitro cell proliferation assay using a modified E-screen assay with MCF-7/BUS cells. RESULTS: Adolescents with Type 1 diabetes had lower oestrogenic activity levels in both phases of the menstrual cycle compared with the control group (follicular phase: 76 vs 94%; luteal phase: 97 vs 131%; P < 0.01), even after adjusting for BMI, oestradiol and oestrone levels. Postmenarcheal adolescents with Type 1 diabetes had lower oestradiol levels compared with control subjects in the follicular phase (63.3 pmol/l vs 89.4 pmol/l; P < 0.01) and higher oestrone levels compared with controls in the luteal phase (196 vs 151.9 pmol/l; P < 0.05). CONCLUSIONS: Adolescents with Type 1 diabetes had lower levels of serum oestrogenic activity, and these were lower than expected based on their serum oestradiol levels. We postulate that changes in the serum milieu of oestrogens in patients with Type 1 diabetes may explain their decreased oestrogenic activity and may play a role in their adverse metabolic profile.


Assuntos
Diabetes Mellitus Tipo 1/sangue , Estradiol/sangue , Adolescente , Estudos de Casos e Controles , Células Cultivadas , Criança , Estudos Transversais , Feminino , Humanos , Células MCF-7 , Ciclo Menstrual/sangue , Ciclo Menstrual/fisiologia
4.
Diabet Med ; 33(1): 70-6, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26043285

RESUMO

AIMS: To evaluate C-reactive protein, insulin growth factor 1 and lipid levels during the follicular and luteal phases in adolescents with Type 1 diabetes. METHODS: Adolescents with Type 1 diabetes (N = 40) and healthy controls (C; N = 43) were studied during the follicular and luteal phases of their menstrual cycles. C-Reactive protein, insulin growth factor 1 and lipid levels were measured. RESULTS: Adolescents with Type 1 diabetes exhibited higher C-reactive protein levels than the C group during the follicular (P < 0.0001) and luteal phases (P < 0.01). The elevation of C-reactive protein levels was more pronounced in overweight adolescents with Type 1 diabetes than in adolescents in the C group. More adolescents with Type 1 diabetes were classified as having an elevated risk of cardiovascular disease (C-reactive protein > 3 mg/l) in the luteal phase than in the follicular phase (37.5% and 17.5%, respectively); half of the overweight adolescents with Type 1 diabetes in the luteal phase reached this level. BMI was the only significant factor affecting follicular and luteal phase C-reactive protein levels in adolescents with Type 1 diabetes. Lower insulin growth factor 1 levels were observed during both phases of the menstrual cycle in adolescents with Type 1 diabetes compared with controls. An elevation in insulin growth factor 1 levels in the luteal phase relative to the follicular phase was observed in controls, but not in adolescents with Type 1 diabetes. Luteal insulin growth factor 1 and C-reactive protein exhibited an inverse correlation (r = -0.4, P = 0.01). CONCLUSIONS: Adolescents with Type 1 diabetes have higher C-reactive protein levels and lower insulin growth factor 1 levels relative to controls, especially during the luteal phase. Type 1 diabetes diminishes the natural elevation in insulin growth factor 1 levels observed during the luteal phase in controls. Excess weight exacerbates the subclinical inflammatory state observed during both phases of the menstrual cycle in adolescents with Type 1 diabetes.


Assuntos
Proteína C-Reativa/análise , Diabetes Mellitus Tipo 1/sangue , Fase Folicular/sangue , Hiperlipidemias/complicações , Fator de Crescimento Insulin-Like I/análise , Fase Luteal/sangue , Sobrepeso/complicações , Adolescente , Biomarcadores/sangue , Índice de Massa Corporal , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/epidemiologia , Chile/epidemiologia , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/imunologia , Angiopatias Diabéticas/epidemiologia , Cardiomiopatias Diabéticas/epidemiologia , Regulação para Baixo , Feminino , Hospitais Públicos , Hospitais Urbanos , Humanos , Hiperlipidemias/epidemiologia , Lipídeos/sangue , Risco , Regulação para Cima
5.
Hum Reprod Update ; 18(5): 568-85, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22709979

RESUMO

BACKGROUND: The functional reproductive alterations seen in women with type 1 diabetes (T1D) have changed as therapy has improved. Historically, patients with T1D and insufficient metabolic control exhibited a high prevalence of amenorrhea, hypogonadism and infertility. This paper reviews the impact of diabetes on the reproductive axis of female T1D patients treated with modern insulin therapy, with special attention to the mechanisms by which diabetes disrupts hypothalamic-pituitary-ovarian function, as documented mainly by animal model studies. METHODS: A comprehensive MEDLINE search of articles published from 1966 to 2012 was performed. Animal model studies on experimental diabetes and human studies on T1D were examined and cross-referenced with terms that referred to different aspects of the gonadotropic axis, gonadotrophins and gonadal steroids. RESULTS: Recent studies have shown that women with T1D still display delayed puberty and menarche, menstrual irregularities (especially oligomenorrhoea), mild hyperandrogenism, polycystic ovarian syndrome, fewer live born children and possibly earlier menopause. Animal models have helped us to decipher the underlying basis of these conditions and have highlighted the variable contributions of defective leptin, insulin and kisspeptin signalling to the mechanisms of perturbed reproduction in T1D. CONCLUSIONS: Despite improvements in insulin therapy, T1D patients still suffer many reproductive problems that warrant specific diagnoses and therapeutic management. Similar to other states of metabolic stress, T1D represents a challenge to the correct functioning of the reproductive axis.


Assuntos
Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/fisiopatologia , Reprodução , Amenorreia/etiologia , Animais , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 1/tratamento farmacológico , Feminino , Humanos , Hiperandrogenismo/etiologia , Hipogonadismo/etiologia , Insulina/uso terapêutico , Menarca , Distúrbios Menstruais/etiologia , Oligomenorreia/etiologia , Síndrome do Ovário Policístico/etiologia , Gravidez , Puberdade Tardia/etiologia
6.
Int J Androl ; 34(5 Pt 2): e487-98, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21831236

RESUMO

Male patients with an extra sex chromosome or autosome are expected to present primary hypogonadism at puberty owing to meiotic germ-cell failure. Scarce information is available on trisomy 21, a frequent autosomal aneuploidy. Our objective was to assess whether trisomy 21 presents with pubertal-onset, germ-cell specific, primary hypogonadism in males, or whether the hypogonadism is established earlier and affects other testicular cell populations. We assessed the functional status of the pituitary-testicular axis, especially Sertoli cell function, in 117 boys with trisomy 21 (ages: 2months-20year). To compare with an adequate control population, we established reference levels for serum anti-Müllerian hormone (AMH) in 421 normal males, from birth to adulthood, using a recently developed ultrasensitive assay. In trisomy 21, AMH was lower than normal, indicating Sertoli cell dysfunction, from early infancy, independently of the existence of cryptorchidism. The overall prevalence rate of AMH below the 3rd percentile was 64.3% in infants with trisomy 21. Follicle-stimulating hormone was elevated in patients <6months and after pubertal onset. Testosterone was within the normal range, but luteinizing hormone was elevated in most patients <6months and after pubertal onset, indicating a mild Leydig cell dysfunction. We conclude that in trisomy 21, primary hypogonadism involves a combined dysfunction of Sertoli and Leydig cells, which can be observed independently of cryptorchidism soon after birth, thus prompting the search for new hypotheses to explain the pathophysiology of gonadal dysfunction in autosomal trisomy.


Assuntos
Hormônio Antimülleriano/sangue , Síndrome de Down/fisiopatologia , Hipogonadismo/fisiopatologia , Adolescente , Adulto , Criança , Pré-Escolar , Síndrome de Down/complicações , Hormônio Foliculoestimulante/sangue , Humanos , Hipogonadismo/sangue , Hipogonadismo/etiologia , Lactente , Recém-Nascido , Células Intersticiais do Testículo/fisiologia , Hormônio Luteinizante/sangue , Masculino , Tamanho do Órgão , Células de Sertoli/fisiologia , Testículo/anatomia & histologia , Testosterona/sangue
7.
Hum Reprod ; 26(10): 2861-8, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21784736

RESUMO

BACKGROUND: The significance of polycystic ovarian morphology (PCOM) during adolescence is not clear. The aim of this study was to determine the relationship between PCOM and anti-Müllerian hormone (AMH), inhibin B, testosterone and insulin levels in healthy girls during the second decade of life. We also determined whether AMH could be used as a surrogate marker of PCOM during adolescence. METHODS: Seventy-four non-obese adolescents (age range: 13.5-19.75 years old) with regular menstrual cycles participated in this study. Transabdominal ultrasound and blood samples were obtained during the follicular phase. RESULTS: PCOM was present in 33.8% of the subjects. Girls with PCOM had higher AMH levels than girls without PCOM (72.5 ± 6.1 versus 33.4 ± 2.6 pmol/l; P < 0.0001) and lower FSH levels (5.4 ± 0.3 versus 6.2 ± 0.2 mUI/ml; P < 0.036). Similar levels of inhibin B, androgens and LH were observed in girls with and without PCOM. PCOM prevalence and AMH levels were not associated with age (P = 0.745 and 0.2, respectively) or BMI-SDS (P = 0.951 and 0.096, respectively). AMH levels positively correlated with the of 2-5 mm follicle number. AMH levels ≥ 60.15 pmol/l had a sensitivity and specificity of 64.0 and 89.8%, respectively, to diagnose PCOM (area under the curve = 0.873). CONCLUSIONS: These data confirm that PCOM in healthy non-hyperandrogenic girls with regular menstrual cycles is prevalent and is not associated with hyperandrogenism. The elevated AMH and lower FSH levels observed in healthy girls with regular menses and PCOM suggest that this ovarian pattern is secondary to a larger number of 2-5 mm follicles. An elevated AMH level is suggestive of the presence of PCOM during adolescence.


Assuntos
Hormônio Antimülleriano/sangue , Regulação da Expressão Gênica , Ciclo Menstrual/fisiologia , Síndrome do Ovário Policístico/patologia , Adolescente , Adulto , Feminino , Humanos , Hiperandrogenismo/diagnóstico , Inibinas/sangue , Insulina/sangue , Ovário/diagnóstico por imagem , Curva ROC , Testosterona/sangue , Ultrassonografia
8.
Rev. chil. endocrinol. diabetes ; 3(1): 36-42, ene. 2010. tab, graf
Artigo em Espanhol | LILACS | ID: lil-610310

RESUMO

Nonclassical adrenal hyperplasia (NC-CAH) is caused by a deficiency in the activity of the 21-hydroxylase enzyme and is the most common autosomal recessive disorder. The clinical features of the disease sre highly variable, and therefore the diagnosis may be overseen. The disorder is characterized by hyperandrogenism of adrenal origin that may become evident during childhood, adolescence or adulthood. The symptoms vary from premature pubarche, mestrual disturbances, hirsutism and virilization to those cases without any clinical evidence of the disease, as described in the cryptic form. The diagnostic approach includes an initial measurement of plasmatic 17OH-progesterone (17OHP) and androgen levels, and an ACTH test in those with elevated baseline 17OHP. The definitive diagnosis of this entity is performed with the documentation of abnormalities in both alleles of the CYP21A2 gene. This paper reviews the clinical, molecular and treatment of patients with NC-CAH.


Assuntos
Humanos , Masculino , Feminino , Hiperplasia Suprarrenal Congênita/diagnóstico , Hiperplasia Suprarrenal Congênita/genética , /análise , Androgênios/análise , /genética , Testes Genéticos , Genótipo , Hiperandrogenismo , Hiperplasia Suprarrenal Congênita/terapia , Hormônio Adrenocorticotrópico , Infertilidade , Mutação , Puberdade Precoce
9.
Rev. chil. endocrinol. diabetes ; 1(1): 7-16, ene. 2008. ilus, tab
Artigo em Espanhol | LILACS | ID: lil-612498

RESUMO

Somatotrophic deficiency (SDMT) can be due to a deficiency of growth hormone releasing hormone(GHRH), growth hormone (GH) or insulin like growth factor I (IGF-I). Although its clinical features have been thoroughly described, the diagnosis is still controversial. Now there is an effective treatment with GH or IGF-I for these patients. AIM: To analyze the main clinical, etiological and laboratory characteristics of 75 SD patients (44 males), aged 9.4 + 4.5 years, with severe growth retardation. The diagnosis was confirmed by the lack of response to two GH stimulation tests (Clonidine, Glugagon or Insulin) and low levels of IGF-I or insulin-like growth factor binding protein- 3 (IGFBP-3). RESULTS: In 34 patients (46 percent), the cause of DSMT was considered idiopathic (DSMT-I), in 31 (41 percent) there was an organic cause (DSMT-O), most commonly caused by malformations or pituitary tumors and in 10 (13 percent), it was genetic (DSMT-G) (three patients with Laron's Syndrome, five with mutations of GH gene and 2 with probable mutations of Prop-1 and Pit-1 genes). IGF-1 levels, were significantly lower in DSMT-O and DSMT-G thanin DSMT-I (21.2 +/- 46.1, 23.4 +/-30.3 ng/mL and 50.2 +/- 48.3 ng/mL, respectively). The lowest height score corresponded to DSMT-G, compared to DSMT-O and DSMT (­5.7 +/- 0.9, -4.0 +/- 1.6 and ­4.3 +/- 1.2 DS, respectively) CONCLUSIONS: The high percentage of organic and genetic etiologies in our patients can be due to the systematic search of these diseases. DSMT-G (Laron, mutations in GH and Pit-1 genes) had the most severe growth retardation.


Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Adulto , Estatura , Hormônio do Crescimento/deficiência , Transtornos do Crescimento/diagnóstico , Transtornos do Crescimento/etiologia , Antropometria , Chile , Nanismo/etiologia , Estudos Retrospectivos , Fator de Crescimento Insulin-Like I/análise , Hormônio do Crescimento/análise , Hormônio do Crescimento/genética , Mutação , Peso Corporal , /análise , Transtornos do Crescimento/genética
10.
Rev. méd. Chile ; 131(8): 857-864, ago. 2003.
Artigo em Espanhol | LILACS | ID: lil-356049

RESUMO

BACKGROUND: During the last decade, the importance of glycemic control in the prevention of the microvascular complications of type 1 Diabetes Mellitus (DM1) was clearly demonstrated. AIM: To evaluate the metabolic and anthropometric results of a multidisciplinary intensified treatment program of DMI in children and adolescents. PATIENTS AND METHODS: Report of 54 patients treated during 2001. The intensified treatment consisted of: multiple daily doses of insulin, frequent glycemic control, nutritional, psychological and educational support, and permanent availability of a diabetes nurse for telephonic support. RESULTS: Thirty one patients were female, their mean age was 10.4 +/- 0.5 years old and 52 per cent were experiencing puberty. Fifty three percent of the patients used 3 insulin doses per day, 95 per cent changed rapid insulin dose based on glucose levels and 18 per cent considered carbohydrates in their rapid insulin dosing. Mean glycosilated hemoglobin was 8.18 +/- 0.23 per cent without differences by sex or pubertal status. Sex, pubertal stage and the number of insulin doses did not contribute to glycosilated hemoglobin changes. There were no differences in weight or BMI, but there was a decrease in height Z score from the admission to the program until the last control (0.1 +/- 0.1 vs--0.3 +/- 0.1 DS; p < 0.01). CONCLUSIONS: A modified intensified modality of DM1 therapy for pediatric patients in a public hospital in Chile is feasible, achieving similar metabolic control, compared to international large centers.


Assuntos
Humanos , Masculino , Feminino , Criança , Adolescente , Antropometria , Chile , Estatísticas não Paramétricas , Glicemia/metabolismo , Hemoglobinas Glicadas/análise , Insulina/administração & dosagem , Resultado do Tratamento
11.
Clin Pharmacol Ther ; 70(1): 91-8, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11452249

RESUMO

Ibutamoren mesylate (MK-0677), an orally active nonpeptide growth hormone (GH) secretagogue, stimulates GH release through a pituitary and hypothalamic receptor that is different from the GH-releasing hormone receptor. We evaluated the safety and tolerability and the GH-insulin-like growth factor (IGF) responses to two dosages of oral ibutamoren mesylate given to children with GH deficiency for 7 to 8 days. The patients, 18 prepubertal children (15 male, 3 female) with idiopathic GH deficiency, had a chronologic age of 10.6 +/- 0.8 years (mean +/- SD), bone age of 7.4 +/- 0.7 years, growth velocity < 10th percentile for age, height < 10th percentile for age, and a maximum GH response of < or = 10 microg/L to two different GH stimulation tests. The children were assigned as follows to one of three treatment groups with ibutamoren mesylate: 0.2 mg/kg per day for 7 days (days 1-7 or 8-14) and matching placebo for the alternate 7 days (groups I and II, respectively) or 0.8 mg/kg per day for 7 days (days 8-14, group III). On day 15 all patients received an 0.8-mg/kg dose of ibutamoren mesylate. Patients in groups I and II were studied first to assess safety at the low dose before advancement to the high dose. Hormonal profiles were evaluated on day -1 (baseline) and day 15, and the results were expressed as the change from baseline within each group. After administration of ibutamoren mesylate 0.8 mg/kg for 8 days (group III), the median increases (on day 15) from baseline were as follows: 3.8 microg/L (range, 0 to 34.3) for serum GH peak concentration (P = .001), 4.3 microg x h/L (range, 1.3 to 35.6) for the GH area under the concentration-time curve from time zero to 8 hours (AUC(0-8)) (P < .001), 12 microg/L (range, -4 to 116) for serum IGF-I (P = .01), and 0.4 microg/L (range, -0.9 to 1.5) for serum IGF-binding protein 3 (IGFBP-3) (P = .01). There was no change in serum prolactin, glucose, triiodothyronine, thyroxine, thyrotropin, peak serum cortisol, and insulin concentrations or 24-hour urinary free cortisol after administration of 0.8 mg/kg per day of ibutamoren mesylate for 8 days. We conclude that short-term administration of ibutamoren mesylate can increase GH, IGF-I, and IGFBP-3 levels in some children with GH deficiency. Thus this compound is applicable for testing its effect on growth velocity.


Assuntos
Hormônio do Crescimento/efeitos dos fármacos , Hormônio do Crescimento/deficiência , Indóis/administração & dosagem , Indóis/farmacologia , Fator de Crescimento Insulin-Like I/efeitos dos fármacos , Erros Inatos do Metabolismo/tratamento farmacológico , Compostos de Espiro/administração & dosagem , Compostos de Espiro/farmacologia , Administração Oral , Criança , Método Duplo-Cego , Feminino , Humanos , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Erros Inatos do Metabolismo/metabolismo , Resultado do Tratamento
12.
Metabolism ; 50(7): 830-4, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11436190

RESUMO

Retinoid X receptor (RXR) is a nuclear receptor that functions as an obligate heterodimeric partner of peroxisome proliferator-activator receptor (PPAR). Studies have shown that the alpha isoform of RXR and PPARgamma act synergistically to regulate gene expression and insulin action. The aim of the current study was to compare the expression and regulation of RXR in the primary insulin-sensitive tissue, skeletal muscle, of various degrees of insulin-resistant states including obese type 2 diabetic (T2D), obese nondiabetic (OND), and lean nondiabetic (LND) subjects. Insulin action/resistance was determined by a 3-hour hyperinsulinemic, euglycemic (5.0 to 5.5 mmol/L) clamp. Percutaneous biopsy of the vastus lateralis muscle was performed before and after the clamp. RXRalpha mRNA was measured using a quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay, while protein was determined by Western blotting. All 3 isoforms of RXR, alpha, beta, and gamma, were present in skeletal muscle. Protein expression of RXR isoforms did not differ between groups; RXR alpha mRNA was also similar between groups. Neither RXR alpha mRNA, RXR -beta nor -gamma protein displayed significant relationships with any of the clinical or laboratory parameters measured, including insulin sensitivity. RXR alpha exhibited a negative correlation with free fatty acids levels (r, -.42, P <.05). There was also no relationship between RXR alpha and PPARgamma protein levels. RXR alpha mRNA was unaltered following insulin infusion. We conclude that RXR isoform (alpha, beta, gamma) expression is not tightly controlled by insulin, insulin resistance or type 2 diabetes. Instead, RXR isoforms are likely constitutive proteins or controlled by other factors.


Assuntos
Diabetes Mellitus Tipo 2/metabolismo , Músculo Esquelético/metabolismo , Obesidade/metabolismo , Receptores do Ácido Retinoico/biossíntese , Fatores de Transcrição/biossíntese , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/etiologia , Glucose/metabolismo , Humanos , Resistência à Insulina , Metabolismo dos Lipídeos , Pessoa de Meia-Idade , Isoformas de Proteínas/biossíntese , Receptores Citoplasmáticos e Nucleares/metabolismo , Receptores do Ácido Retinoico/agonistas , Receptores X de Retinoides , Fatores de Transcrição/agonistas , Fatores de Transcrição/metabolismo
13.
Rev Med Chil ; 129(12): 1365-72, 2001 Dec.
Artigo em Espanhol | MEDLINE | ID: mdl-12080873

RESUMO

BACKGROUND: McCune-Albright Syndrome (MAS) is characterized by precocious puberty, "cafe au lait" skin lesions and polyostotic fibrous dysplasia. It is caused by 4 post-zygotic mutations of G alpha s protein with a mosaic distribution. AIM: To describe the clinical presentation and to investigate the presence of the Arg by his substitution (R201H) in 14 girls with MAS. PATIENTS AND METHODS: We performed a clinical analysis of the patients and specific allele PCR in DNA obtained from leukocytes. RESULTS: Twelve of 14 patients presented with precocious puberty, one with cyclical vaginal bleeding and one with pathological bone fractures. Eight girls had polyostotic fibrous dysplasia, one had hyperthyroidism, four had pathological fractures, ten had ovarian cysts, six had breast hyperpigmentation and ten had "cafe au lait" skin lesions. We detected the R2O1H mutation in 10 of 14 patients. We found no difference in the severity of symptoms or in the age of presentation between the patients with and without the mutation. CONCLUSIONS: The R201H mutation can be detected in white blood cells, in approximately 70% of cases. Patients exhibit wide clinical variability with the same molecular defect. This suggests that tissues have different proportions of mutant cells.


Assuntos
Manchas Café com Leite/genética , Displasia Fibrosa Poliostótica/genética , Leucócitos , Puberdade Precoce/genética , Adolescente , Estudos de Casos e Controles , Criança , Análise Mutacional de DNA , Feminino , Humanos , Masculino , Reação em Cadeia da Polimerase , Síndrome
14.
J Pediatr Endocrinol Metab ; 13(7): 887-92, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10968476

RESUMO

The biochemical mediators responsible for variations in stature among normal subjects are largely unknown. To obtain some initial information about potential endocrine factors, we measured the serum concentrations of GH, IGF-1, IGFBP-3 and GHBP in healthy young men shorter than 159 cm and taller than 187 cm. We studied 14 volleyball and basketball players (tall group), and 14 jockey students from a horse racetrack (short group). A careful medical history was taken, including dietary intake, and physical examination with special attention to the possible presence of genetic stigmata was performed. Serum prealbumin was determined as an index of nutritional status. A buccal smear was performed to exclude Klinefelter's syndrome. The BMI and serum prealbumin levels were comparable in both groups of individuals. The nutritional survey, however, revealed that the tall subjects had a higher intake of calories (42.2+/-11.2 vs. 30.1+/-15.15 kcal/kg, p<0.05), and protein (1.5+/-0.6 vs. 0.8+/-0.4 mg/kg, p<0.01). Serum concentrations of GHBP did not differ in the two groups (0.95+/-0.37 nmol/l in the tall, and 0.95+/-0.53 nmol/l in the short group), and did not correlate with height, serum IGF-I levels, or BMI. We observed a significant difference in the serum concentrations of IGF-I in the two groups of individuals (42.02+/-9.37 nmol/l in the tall and 31.79+/-3.18 nmol/l in the short group, p<0.05), and this growth factor showed a positive correlation with height (r = 0.5, p<0.01). These preliminary findings suggest that final height differences in young men do not appear to be mediated by variations in GHBP concentrations.


Assuntos
Estatura , Proteínas de Transporte/sangue , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/metabolismo , Humanos , Masculino , Reprodutibilidade dos Testes
15.
Rev Med Chil ; 127(7): 807-13, 1999 Jul.
Artigo em Espanhol | MEDLINE | ID: mdl-10668288

RESUMO

BACKGROUND: The diagnosis of GH deficiency (GHD) is based upon the results of GH stimulation tests, which have several drawbacks. AIM: To evaluate the usefulness of IGF-1 and IGFBP-3 for the diagnosis of GHD in prepuberal children. MATERIAL AND METHODS: We measured IGF-I and IGFBP-3 in three group of subjects: I. GHD (n: 24), height < -2SD for age (Z score, average +/- SD: -4.2 +/- 1.2), growth velocity < p10 (3.4 +/- 1.0 cm/year) and peak GH level on two GH stimulation tests < 7 ng/ml (1.2 +/- 0.6 ng/ml); II. Short non-GHD (NGHD, n: 32), height of -2.7 +/- 0.9 SD for age, growth velocity < p 25 (3.9 +/- 1.2 cm/year), and peak GH level on two GH stimulation tests > 7 ng/ml (15.3 +/- 6.9 ng/ml), y III. Normal school children (n: 35) with normal heights (-0.17 +/- 0.12 SD) were studied as controls. RESULTS: IGF-1 and IGFBP-3 were significantly lower in GHD than in NGHD and controls (p < 0.001), and in NGHD than in C (p < 0.001). We defined the normal range of both proteins as +/- 2 SD of the mean of the control group. Using this criteria, IGF-I was low in 21/24 GHD, and in 12/32 NGHD. IGFBP-3 was low in 22/24 GHD, and in 6/32 NGHD. Only 1 GHD patient had both exams in the normal range, suggesting that he is probably NGHD. 4/32 of the NGHD and both exams below normal range, suggesting that they are probably GHD. CONCLUSIONS: IGF-1 and IGFBP-3 are important tools for the diagnosis of GHD.


Assuntos
Transtornos do Crescimento/diagnóstico , Hormônio do Crescimento Humano/deficiência , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/sangue , Fator de Crescimento Insulin-Like I/análise , Criança , Feminino , Humanos , Masculino
16.
J Pediatr Endocrinol Metab ; 12(3): 381-7, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10821217

RESUMO

Hypersecretion of GH is usually caused by a pituitary adenoma and about 40% of these tumors exhibit missense gsp mutations in Arg201 or Gln227 of the Gs, gene. We studied 20 pituitary tumors obtained from patients with GH hypersecretion. One tumor was resected from an 11 year-old boy with a 3 year history of accelerated growth, associated with increased concentrations of serum GH and IGF-I, which were not suppressed by glucose administration. The remaining 19 tumors were obtained from adult acromegalic patients, who had elevated baseline serum GH levels that did not show evidence of suppression after administration of glucose. The gsp mutations were studied by enzymatic digestion of the amplified PCR fragment of exon 8 (Arg201) and exon 9 (Gln227) with the enzymes NlaIII and NgoAIV, respectively. The tumors obtained from the boy and from nine of the 19 patients with acromegaly exhibited the gsp mutation R201H. None of the tumors had the Gln227 mutation. The gsp positive patients tended to be older, had smaller tumors, and had preoperative basal serum GH levels which were significantly lower (21 +/- 6 vs 56 +/- 16 microg/l, p<0.05) than the gsp negative patients. In this study, we documented the presence of a gsp mutation in Arg201 in a boy with gigantism and in approximately half of 19 Chilean adult patients with acromegaly, similar to other populations.


Assuntos
Adenoma/genética , Adenoma/metabolismo , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Hormônio do Crescimento Humano/metabolismo , Mutação de Sentido Incorreto/genética , Proteínas Oncogênicas/genética , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/metabolismo , Adenoma/complicações , Criança , Chile , Códon/genética , DNA/genética , DNA/isolamento & purificação , Gigantismo/etiologia , Gigantismo/genética , Gigantismo/fisiopatologia , Teste de Tolerância a Glucose , Crescimento/fisiologia , Humanos , Imuno-Histoquímica , Imageamento por Ressonância Magnética , Masculino , Neoplasias Hipofisárias/complicações , Reação em Cadeia da Polimerase Via Transcriptase Reversa
17.
Horm Res ; 48 Suppl 5: 16-20, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9434040

RESUMO

During puberty, growth hormone (GH)-deficient children may experience difficulties achieving an appropriate pubertal growth spurt. We review the complex hormonal interactions which occur during puberty. At least two therapeutic strategies have been developed to optimize GH therapy during puberty. In the first strategy, the GH dose administered per kilogram of body weight is increased during puberty, in an attempt to mimic the physiological increase of GH which occurs during puberty. In the second strategy, luteinizing hormone-releasing hormone (LHRH) analogs are administered concomitantly with GH with the aim of delaying epiphyseal fusion. The efficacy of these strategies to increase final height has not previously been clearly demonstrated.


Assuntos
Transtornos do Crescimento/tratamento farmacológico , Hormônio do Crescimento/administração & dosagem , Hormônio do Crescimento/uso terapêutico , Puberdade/fisiologia , Adolescente , Criança , Hormônio do Crescimento/deficiência , Humanos
18.
J Am Vet Med Assoc ; 206(6): 812-6, 1995 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-7759333

RESUMO

Fifty dogs underwent intradermal allergy testing with housedust mite and house dust extracts, using concentrations recommended by the manufacturer. Twelve dogs (group I) were healthy dogs obtained from a pound; 12 dogs (group II) were healthy, privately owned dogs; 15 dogs (group III) were suspected of being atopic and had had multiple positive reactions to intradermal injections of allergens of specific trees, weeds, grasses, or molds; and 11 dogs (group IV) were suspected of being atopic, but only had had positive reactions to intradermal injections of housedust mite, house dust, and flea antigen extracts. Use of the concentrations of housedust mite and house dust extracts currently recommended for intradermal allergy testing resulted in false-positive reactions in 14 of 24 (58%) and 12 of 24 (50%) healthy dogs tested, respectively. Differences in number of dogs with positive reactions or grade of reaction to housedust mite or house dust allergens were not detected between groups of healthy dogs (groups I vs II), between groups of suspected atopic dogs (groups III vs IV), or between healthy dogs and dogs suspected of being atopic (groups I and II vs III and IV). Therefore, clinical importance of positive results of intradermal allergy testing of house dust or housedust mite allergens was equivocal for dogs suspected of being atopic. Threshold concentrations for intradermal allergy testing were determined in 24 healthy dogs (group I and II) by intradermal administration of 5 dilutions each of housedust mite extract and house dust extract.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Alérgenos/imunologia , Doenças do Cão/diagnóstico , Poeira/efeitos adversos , Hipersensibilidade Imediata/veterinária , Ácaros/imunologia , Animais , Cães , Reações Falso-Positivas , Hipersensibilidade Imediata/diagnóstico , Testes Intradérmicos/normas , Testes Intradérmicos/veterinária
19.
J Am Vet Med Assoc ; 202(7): 1106-10, 1993 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8473224

RESUMO

Computed tomography was evaluated as a noninvasive technique for the diagnosis of chronic nasal disease in dogs. Computed tomographic images, radiographs, and histopathologic findings were compared in 11 dogs with chronic nasal disease. Definitive diagnosis was made following traumatic nasal flush, exploratory surgery, or necropsy. The study included 8 dogs with intranasal tumors, 2 dogs with bacterial rhinitis (Pasteurella sp), and 1 dog with mycotic rhinitis (Aspergillus sp). Computed tomography was superior to radiography in defining the extent of the disease process and in differentiating infectious rhinitis from nasal neoplasms. It defined lesions in the palate, nasopharyngeal meatus, maxillary sinus, caudal ethmoturbinates, and periorbital tissues that were difficult to demonstrate by use of conventional radiography. Tumors appeared as space-occupying lesions that obliterated the turbinates, caused deviation of the nasal septum, and eroded bone. Rhinitis appeared as a cavitating lesion that spared the paranasal sinuses, thickened and distorted the turbinates, and widened the meatus. Although morphologically distinct on computed tomographic images, infectious rhinitis and nasal neoplasms could not be differentiated by attenuation measurements or degree of contrast enhancement. Computed tomography appeared to be a reliable, noninvasive technique for the diagnosis of chronic nasal disease in dogs, and a promising alternative to diagnostic techniques currently in use.


Assuntos
Doenças do Cão/diagnóstico por imagem , Doenças Nasais/veterinária , Tomografia Computadorizada por Raios X/veterinária , Animais , Aspergilose/diagnóstico por imagem , Aspergilose/veterinária , Doença Crônica , Diagnóstico Diferencial , Cães , Doenças Nasais/diagnóstico por imagem , Neoplasias Nasais/diagnóstico por imagem , Neoplasias Nasais/veterinária , Infecções por Pasteurella/diagnóstico por imagem , Infecções por Pasteurella/veterinária , Rinite/diagnóstico por imagem , Rinite/veterinária , Conchas Nasais/diagnóstico por imagem
20.
J Am Vet Med Assoc ; 202(5): 739-43, 1993 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-8454505

RESUMO

Results of an ELISA for allergen-specific IgE were compared with results of an intradermal (ID) allergy test in 5 clinically normal dogs and 36 dogs referred for evaluation of allergic dermatitis. The ELISA had a sensitivity of 100% and a specificity of 0%. Agreement between ID allergy test and ELISA for positive and negative results ranged from 44 to 56% for pollens, 39% for house dust/dust mite, 22% for fungi, and 54% for fleas. Agreement between ID allergy test and ELISA scores for all pollens was only 10% greater than that expected by chance alone, and a kappa value of 0.17 confirmed poor test agreement. The greatest disparity in results was seen in dogs with negative ID and positive ELISA results. Median ELISA absorbance values for 15 groups of related allergens were compared in 4 groups of dogs: clinically normal dogs, atopic dogs with positive ID reactivity, suspected atopic dogs with negative ID reactivity, and flea-allergic dogs. There was no significant difference in median ELISA values between clinically normal dogs and flea-allergic dogs, or clinically normal dogs and atopic dogs for any allergen group. Although the ELISA absorbance value for fungal antigens was significantly higher in dogs suspected of being atopic than in clinically normal dogs, there was no significant difference in median ELISA values for any other allergen group. These findings suggested the disparity between ID allergy test and ELISA results was primarily attributable to false-positive ELISA reactions rather than greater ELISA sensitivity.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Dermatite Atópica/veterinária , Doenças do Cão/diagnóstico , Ensaio de Imunoadsorção Enzimática/veterinária , Imunoglobulina E/sangue , Testes Intradérmicos/veterinária , Animais , Dermatite Atópica/diagnóstico , Cães , Poeira , Ácaros/imunologia , Pólen/imunologia , Sensibilidade e Especificidade , Sifonápteros/imunologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...