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1.
Diabetes Res Clin Pract ; 212: 111724, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38821415

RESUMO

This review aims to identify and report epidemiological associations between modifiable lifestyle risk factors for overweight or obesity in children and adolescents with type 1 diabetes (T1D). A systematic literature search of medical databases from 1990 to 2023 was undertaken. Inclusion criteria were observational studies reporting on associations between dietary factors, disordered eating, physical activity, sedentary and sleep behaviours and measures of adiposity in children and adolescents (<18 years) with T1D. Thirty-seven studies met inclusion criteria. Studies were mostly cross-sectional (89 %), and 13 studies included adolescents up to 19 years which were included in this analysis. In adolescents with T1D, higher adiposity was positively associated with disordered eating behaviours (DEB) and a higher than recommended total fat and lower carbohydrate intake. A small amount of evidence suggested a positive association with skipping meals, and negative associations with diet quality and sleep stage. There were no published associations between overweight and physical activity, sedentary behaviours and eating disorders. Overall, the findings infer relationships between DEB, fat and carbohydrate intake and adiposity outcomes in people with T1D. Prospective studies are needed to determine causal relationships and to investigate sleep stages. High quality studies objectively measuring physical activity and include body composition outcomes are needed.


Assuntos
Diabetes Mellitus Tipo 1 , Estilo de Vida , Humanos , Adolescente , Diabetes Mellitus Tipo 1/epidemiologia , Diabetes Mellitus Tipo 1/complicações , Criança , Fatores de Risco , Exercício Físico , Obesidade Infantil/epidemiologia , Obesidade Infantil/complicações , Sobrepeso/epidemiologia , Sobrepeso/complicações , Comportamento Alimentar/fisiologia , Comportamento Sedentário , Feminino
2.
J Am Coll Health ; 71(1): 76-79, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-33577422

RESUMO

Objective: To determine whether university students are aware of the sexual health services offered by the student health center. Participants: 522 undergraduate students at a southeast public university. Methods: Students were given a list of 19 sexual health services and tests and were instructed that for each one to check "offered," "not offered," or "I'm not sure." Results: Students were generally unaware that the health center offered testing for a variety of sexually transmitted infections (13-27.4% aware), the Gardasil vaccine for human papillomavirus (HPV) (15.5% aware), the IUD (8.8% aware), emergency contraception (18.6% aware), and breast (24.9% aware) and pelvic examinations (16.5% aware). The only exceptions were for free male condoms (63% aware) and women's awareness of birth control pills (55.3% aware) and pregnancy testing (50.3% aware). Nearly half the students were not aware that parents/guardians could not obtain health center medical records without the student's permission. Conclusions: Student health centers cannot be effective in reducing unwanted pregnancies and the spread of STIs if students are unaware of the services provided. Health centers must do a better job of educating students.


Assuntos
Infecções Sexualmente Transmissíveis , Serviços de Saúde para Estudantes , Gravidez , Humanos , Masculino , Feminino , Universidades , Estudantes , Inquéritos e Questionários , Comportamento Sexual , Infecções Sexualmente Transmissíveis/prevenção & controle , Conhecimentos, Atitudes e Prática em Saúde
3.
J Clin Endocrinol Metab ; 107(1): e205-e213, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34410410

RESUMO

CONTEXT: Dietary fat and protein impact postprandial hyperglycemia in people with type 1 diabetes, but the underlying mechanisms are poorly understood. Glucoregulatory hormones are also known to modulate gastric emptying and may contribute to this effect. OBJECTIVE: Investigate the effects of fat and protein on glucagon-like peptide (GLP-1), glucagon-dependent insulinotropic polypeptide (GIP) and glucagon secretion. METHODS: 2 crossover euglycemic insulin clamp clinical trials at 2 Australian pediatric diabetes centers. Participants were 12-21 years (n = 21) with type 1 diabetes for ≥1 year. Participants consumed a low-protein (LP) or high-protein (HP) meal in Study 1, and low-protein/low-fat (LPLF) or high-protein/high-fat (HPHF) meal in Study 2, all containing 30 g of carbohydrate. An insulin clamp was used to maintain postprandial euglycemia and plasma glucoregulatory hormones were measured every 30 minutes for 5 hours. Data from both cohorts (n = 11, 10) were analyzed separately. The main outcome measure was area under the curve of GLP-1, GIP, and glucagon. RESULTS: Meals low in fat and protein had minimal effect on GLP-1, while there was sustained elevation after HP (80.3 ± 16.8 pmol/L) vs LP (56.9 ± 18.6), P = .016, and HPHF (103.0 ± 26.9) vs LPLF (69.5 ± 31.9) meals, P = .002. The prompt rise in GIP after all meals was greater after HP (190.2 ± 35.7 pmol/L) vs LP (152.3 ± 23.3), P = .003, and HPHF (258.6 ± 31.0) vs LPLF (151.7 ± 29.4), P < .001. A rise in glucagon was also seen in response to protein, and HP (292.5 ± 88.1 pg/mL) vs LP (182.8 ± 48.5), P = .010. CONCLUSION: The impact of fat and protein on postprandial glucose excursions may be mediated by the differential secretion of glucoregulatory hormones. Further studies to better understand these mechanisms may lead to improved personalized postprandial glucose management.


Assuntos
Biomarcadores/sangue , Glicemia/análise , Diabetes Mellitus Tipo 1/fisiopatologia , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Hiperglicemia/epidemiologia , Refeições , Adulto , Austrália/epidemiologia , Peptídeo C/sangue , Estudos Cross-Over , Feminino , Seguimentos , Esvaziamento Gástrico , Polipeptídeo Inibidor Gástrico/sangue , Glucagon/sangue , Peptídeo 1 Semelhante ao Glucagon/sangue , Humanos , Hiperglicemia/sangue , Hiperglicemia/patologia , Hiperglicemia/prevenção & controle , Insulina/sangue , Masculino , Prognóstico
4.
J Sex Marital Ther ; 47(1): 80-89, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-32666897

RESUMO

Most men believe that the average length of an erect penis is greater than 6 inches (15.24 cm). This belief is due, in part, to several often-cited studies that relied on self-reported measurements, with means of about 6.2 inches (15.75 cm) for heterosexual men and even greater for gay men. These studies suffered from both volunteer bias and social desirability bias. In this review, the combined mean for 10 studies in which researchers took measurements of erect penises was 5.36 inches (13.61 cm; n = 1,629). For 21 studies in which researchers measured stretched penises, the mean was approximately 5.11 inches (12.98 cm; n = 13,719). Based on these studies, the average length of an erect penis is between 5.1 and 5.5 inches (12.95-13.97 cm), but after taking volunteer bias into account, it is probably toward the lower end of this range. Studies show that a majority of men wish they were larger, with some choosing penile lengthening surgery. These surgeries are considered by the American Urological Association to be risky. Most men seeking surgery have normal sized penises. Counseling with factual information about penis size might be effective in alleviating concerns for the majority of men who worry about having a small penis.


Assuntos
Imagem Corporal/psicologia , Ereção Peniana , Pênis/anatomia & histologia , Aconselhamento , Humanos , Masculino , Tamanho do Órgão
5.
Acta Neuropathol ; 140(6): 907-917, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-32892244

RESUMO

Paragangliomas are neuroendocrine tumors of the autonomic nervous system that are variably clinically functional and have a potential for metastasis. Up to 40% occur in the setting of a hereditary syndrome, most commonly due to germline mutations in succinate dehydrogenase (SDHx) genes. Immunohistochemically, paragangliomas are characteristically GATA3-positive and cytokeratin-negative, with loss of SDHB expression in most hereditary cases. In contrast, the rare paragangliomas arising in the cauda equina (CEP) or filum terminale region have been shown to be hormonally silent, clinically indolent, and have variable keratin expression, suggesting these tumors may represent a separate pathologic entity. We retrospectively evaluated 17 CEPs from 11 male and 6 female patients with a median age of 38 years (range 21-82), none with a family history of neuroendocrine neoplasia. Six of the 17 tumors demonstrated prominent gangliocytic or ganglioneuromatous differentiation. By immunohistochemistry, none of the CEPs showed GATA3 positivity or loss of SDHB staining; all 17 CEPs were cytokeratin positive. Genome-wide DNA methylation profiling was performed on 12 of the tumors and compared with publicly available genome-wide DNA methylation data. Clustering analysis showed that CEPs form a distinct epigenetic group, separate from paragangliomas of extraspinal sites, pheochromocytomas, and other neuroendocrine neoplasms. Copy number analysis revealed diploid genomes in the vast majority of CEPs, whereas extraspinal paragangliomas were mostly aneuploid with recurrent trisomy 1q and monosomies of 1p, 3, and 11, none of which were present in the cohort of CEP. Together, these findings indicate that CEPs likely represent a distinct entity. Future genomic studies are needed to further elucidate the molecular pathogenesis of these tumors.


Assuntos
Cauda Equina/patologia , Neoplasias do Sistema Nervoso Central/genética , Variações do Número de Cópias de DNA/fisiologia , Metilação de DNA/fisiologia , Imuno-Histoquímica , Paraganglioma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Cauda Equina/metabolismo , Feminino , Mutação em Linhagem Germinativa/genética , Mutação em Linhagem Germinativa/fisiologia , Humanos , Imuno-Histoquímica/métodos , Masculino , Pessoa de Meia-Idade , Paraganglioma/genética , Adulto Jovem
6.
Front Public Health ; 6: 270, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30298125

RESUMO

As the use of mobile phone devices is now highly prevalent, many studies have sought to evaluate the effects of the radiofrequency-electromagnetic radiation (RF-EMR) on both human health and biology. While several such studies have shown RF-EMR is capable of inducing cellular stress, the physicobiological origin of this stress remains largely unresolved. To explore the effect of RF-EMR on the male reproductive system, we exposed cultured mouse spermatogonial GC1 and spermatocyte GC2 cell lines, as well as cauda epididymal spermatozoa to a waveguide generating continuous wave RF-EMR (1.8 GHz, 0.15 and 1.5 W/kg). This study demonstrated that a 4 h exposure is capable of inducing the generation of mitochondrial reactive oxygen species (ROS) in populations of GC1 (7 vs. 18%; p < 0.001) and GC2 cells (11.5 vs. 16 %; p < 0.01), identifying Complex III of the electron transport chain (ETC) as the potential source of electrons producing ROS. Assessing the generation of ROS in the presence of an antioxidant, penicillamine, as well as measuring lipid peroxidation via 4-hydroxynonenal levels, indicated that the elevated incidence of ROS generation observed under our exposure conditions did not necessarily induce an overt cellular oxidative stress response. However, exposure to RF-EMR at 0.15 W/kg for 3 h did induce significant DNA fragmentation in spermatozoa (that was no longer significant after 4 h), assessed by the alkaline comet assay (p < 0.05). Furthermore, this fragmentation was accompanied by an induction of oxidative DNA damage in the form of 8-hydroxy-2'-deoxyguanosine, which was significant (p < 0.05) after spermatozoa were exposed to RF-EMR for 4 h. At this exposure time point, a decline in sperm motility (p < 0.05) was also observed. This study contributes new evidence toward elucidating a mechanism to account for the effects of RF-EMR on biological systems, proposing Complex III of the mitochondrial ETC as the key target of this radiation.

7.
Diabetes Care ; 40(8): 1034-1040, 2017 08.
Artigo em Inglês | MEDLINE | ID: mdl-28546222

RESUMO

OBJECTIVE: Celiac disease (CD) has a recognized association with type 1 diabetes. We examined international differences in CD prevalence and clinical characteristics of youth with coexisting type 1 diabetes and CD versus type 1 diabetes only. RESEARCH DESIGN AND METHODS: Data sources were as follows: the Prospective Diabetes Follow-up Registry (DPV) (Germany/Austria); the T1D Exchange Clinic Network (T1DX) (U.S.); the National Paediatric Diabetes Audit (NPDA) (U.K. [England/Wales]); and the Australasian Diabetes Data Network (ADDN) (Australia). The analysis included 52,721 youths <18 years of age with a clinic visit between April 2013 and March 2014. Multivariable linear and logistic regression models were constructed to analyze the relationship between outcomes (HbA1c, height SD score [SDS], overweight/obesity) and type 1 diabetes/CD versus type 1 diabetes, adjusting for sex, age, and diabetes duration. RESULTS: Biopsy-confirmed CD was present in 1,835 youths (3.5%) and was diagnosed at a median age of 8.1 years (interquartile range 5.3-11.2 years). Diabetes duration at CD diagnosis was <1 year in 37% of youths, >1-2 years in 18% of youths, >3-5 years in 23% of youths, and >5 years in 17% of youths. CD prevalence ranged from 1.9% in the T1DX to 7.7% in the ADDN and was higher in girls than boys (4.3% vs. 2.7%, P < 0.001). Children with coexisting CD were younger at diabetes diagnosis compared with those with type 1 diabetes only (5.4 vs. 7.0 years of age, P < 0.001) and fewer were nonwhite (15 vs. 18%, P < 0.001). Height SDS was lower in those with CD (0.36 vs. 0.48, adjusted P < 0.001) and fewer were overweight/obese (34 vs. 37%, adjusted P < 0.001), whereas mean HbA1c values were comparable: 8.3 ± 1.5% (67 ± 17 mmol/mol) versus 8.4 ± 1.6% (68 ± 17 mmol/mol). CONCLUSIONS: CD is a common comorbidity in youth with type 1 diabetes. Differences in CD prevalence may reflect international variation in screening and diagnostic practices, and/or CD risk. Although glycemic control was not different, the lower height SDS supports close monitoring of growth and nutrition in this population.


Assuntos
Doença Celíaca/epidemiologia , Diabetes Mellitus Tipo 1/epidemiologia , Sistema de Registros , Adolescente , Austrália/epidemiologia , Glicemia/análise , Doença Celíaca/diagnóstico , Criança , Pré-Escolar , Comorbidade , Diabetes Mellitus Tipo 1/diagnóstico , Inglaterra/epidemiologia , Feminino , Seguimentos , Alemanha/epidemiologia , Hemoglobinas Glicadas/análise , Humanos , Masculino , Prevalência , Estudos Prospectivos , País de Gales/epidemiologia
8.
PLoS One ; 4(7): e6446, 2009 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-19649291

RESUMO

BACKGROUND: In recent times there has been some controversy over the impact of electromagnetic radiation on human health. The significance of mobile phone radiation on male reproduction is a key element of this debate since several studies have suggested a relationship between mobile phone use and semen quality. The potential mechanisms involved have not been established, however, human spermatozoa are known to be particularly vulnerable to oxidative stress by virtue of the abundant availability of substrates for free radical attack and the lack of cytoplasmic space to accommodate antioxidant enzymes. Moreover, the induction of oxidative stress in these cells not only perturbs their capacity for fertilization but also contributes to sperm DNA damage. The latter has, in turn, been linked with poor fertility, an increased incidence of miscarriage and morbidity in the offspring, including childhood cancer. In light of these associations, we have analyzed the influence of RF-EMR on the cell biology of human spermatozoa in vitro. PRINCIPAL FINDINGS: Purified human spermatozoa were exposed to radio-frequency electromagnetic radiation (RF-EMR) tuned to 1.8 GHz and covering a range of specific absorption rates (SAR) from 0.4 W/kg to 27.5 W/kg. In step with increasing SAR, motility and vitality were significantly reduced after RF-EMR exposure, while the mitochondrial generation of reactive oxygen species and DNA fragmentation were significantly elevated (P<0.001). Furthermore, we also observed highly significant relationships between SAR, the oxidative DNA damage bio-marker, 8-OH-dG, and DNA fragmentation after RF-EMR exposure. CONCLUSIONS: RF-EMR in both the power density and frequency range of mobile phones enhances mitochondrial reactive oxygen species generation by human spermatozoa, decreasing the motility and vitality of these cells while stimulating DNA base adduct formation and, ultimately DNA fragmentation. These findings have clear implications for the safety of extensive mobile phone use by males of reproductive age, potentially affecting both their fertility and the health and wellbeing of their offspring.


Assuntos
Telefone Celular , Dano ao DNA , Espécies Reativas de Oxigênio/metabolismo , Espermatozoides/efeitos da radiação , Fragmentação do DNA/efeitos da radiação , Campos Eletromagnéticos , Humanos , Masculino , Estresse Oxidativo
9.
Am J Kidney Dis ; 53(3): 492-502, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19150156

RESUMO

BACKGROUND: Catheter-restricted antimicrobial lock (AML) use reduces catheter-associated bloodstream infection (CA-BSI) in clinical trial settings, but may not be as effective in clinical settings and may increase bacterial resistance. DESIGN: Quality improvement report analyzed using a cross-sectional time series (unbalanced panel) design. SETTING & PARTICIPANTS: The study cohort comprised all prevalent adults treated with hemodialysis through a tunneled catheter for any, but not necessarily all, of the time from January 1, 2003, to June 30, 2006, in Manukau City, New Zealand (135,346 catheter-days, 404 tunneled catheters, 320 patients). QUALITY IMPROVEMENT PLAN: Catheter-restricted AMLs (heparin plus gentamicin) for all tunneled catheters from July 1, 2004. MEASURES: Repeated observations of CA-BSI, hospitalization, tunneled catheter removal, and death from CA-BSI analyzed by using generalized estimating equations with a single level of clustering for each tunneled catheter and patterns of bacterial resistance analyzed by using simple descriptive statistics. RESULTS: AML use was associated with reductions in rates of CA-BSI and hospitalization for CA-BSI by 52% and 69% for patients with tunneled catheters locked continuously with AMLs since their insertion compared with those with tunneled catheters that were not, respectively. AML exposure also was associated with a trend to increased gentamicin resistance amongst coagulase-negative staphylococci isolates, a pattern similar to that observed for BSIs in our general hemodialysis population in which tunneled catheters were not the source of BSI, but different from that in the general non-end-stage renal disease population in the region. LIMITATIONS: This is an uncontrolled observational study and cannot prove causality. The follow-up period of 18 months is longer than for other studies, but still too short to definitely answer whether AML use drives bacterial resistance. CONCLUSIONS: A change to use of AMLs may improve clinical outcomes; however, additional study of associated bacterial resistance is needed before AML use becomes standard care.


Assuntos
Antibacterianos/uso terapêutico , Infecções Relacionadas a Cateter/prevenção & controle , Cateteres de Demora , Farmacorresistência Bacteriana , Gentamicinas/uso terapêutico , Diálise Renal , Sepse/prevenção & controle , Idoso , Estudos Transversais , Desenho de Equipamento , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
Front Biosci ; 12: 581-90, 2007 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-17127319

RESUMO

Glucocorticoids inhibit corticotrophin-releasing hormone (CRH) gene expression in the hypothalamic paraventricular nucleus (PVN), but stimulate expression in the placenta. In AtT20 cells (a model of PVN CRH production) cAMP produces a high level of promoter activity. Cyclic AMP stimulation occurs through the cAMP response element (CRE) and the caudal type homeobox protein response element (CDXARE). The CRE acts as part of a cAMP response unit that includes the hybrid steroid response element (HRE), ecdysone response element (EcRE), metal-responsive transcription factor-1 response element (MTFRE), ying yang 1 response element (YY1RE) and negative glucocorticoid response element (nGRE). Cyclic AMP acts on the HRE, EcRE and MTFRE to block YY1RE mediated inhibition of the CRE. Glucocorticoids acting at the nGRE inhibit cAMP activation of the CRE. In placental cells the CRH promoter has low intrinsic basal activity and cAMP causes a modest increase in activity. Stimulation by glucocorticoids and cAMP and inhibition by estrogen and estrogen receptor alpha occurs through the CRE. In AtT20 cells multiple response elements coordinate a response to cAMP and glucocorticoids while in placental cells the CRE acts in isolation. These differences in promoter function lead to responses that meet specific physiological needs.


Assuntos
Hormônio Liberador da Corticotropina/genética , Regulação da Expressão Gênica , Elementos de Resposta , Animais , Hormônio Liberador da Corticotropina/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Placenta/metabolismo , Regiões Promotoras Genéticas
11.
Am J Physiol Regul Integr Comp Physiol ; 291(5): R1201-14, 2006 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-16778067

RESUMO

Lesions of the amygdala have long been known to produce hyperphagia and obesity in cats, dogs, and monkeys, but only recently have studies with rats determined that the effective site is the posterodorsal amygdala (PDA)-the posterodorsal medial amygdaloid nucleus and the intra-amygdaloid bed nucleus of the stria terminalis. There is a sex difference; female rats with PDA lesions display greater weight gain than male rats. In the brains of female rats with obesity-inducing PDA lesions, there is a dense pattern of axonal degeneration in the capsule of the ventromedial hypothalamus (VMH) and other targets of the stria terminalis. Transections of the dorsal component of the stria terminalis also result in hyperphagia and obesity in female rats. Similar to rats with VMH lesions, rats with PDA lesions are hyperinsulinemic during food restriction and greatly prefer high-carbohydrate diets. The PDA is also a critical site for some aspects of rodent sexual behavior, particularly those that depend on olfaction, and the pattern of degeneration observed after obesity-inducing PDA lesions is remarkably parallel to the circuit that has been proposed to mediate sexual behavior. Medial amygdaloid lesions disrupt the normal feeding pattern and result in impaired responses to caloric challenges, and there is evidence that these behavioral changes are also due to a disruption of olfactory input. With its input from the olfactory bulbs and connections to the VMH, the PDA may be a nodal point at which olfactory and neuroendocrine stimuli are integrated to affect feeding behavior.


Assuntos
Tonsila do Cerebelo/patologia , Neoplasias Encefálicas/complicações , Hipotálamo Médio/fisiologia , Obesidade/etiologia , Comportamento Sexual Animal/fisiologia , Olfato/fisiologia , Animais , Neoplasias Encefálicas/fisiopatologia , Gatos , Cães , Comportamento Alimentar/fisiologia , Feminino , Haplorrinos , Humanos , Masculino , Obesidade/fisiopatologia , Condutos Olfatórios/fisiologia , Ratos , Caracteres Sexuais
12.
Biochem Cell Biol ; 84(1): 9-19, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16462885

RESUMO

We describe a unique family of human proteins that are capable of binding to the cAMP regulatory element (CRE) and that are homologous to RNA splicing proteins. A human cDNA was isolated that encodes a protein with a distinctive combination of modular domain structures: 2 leucine-zipper-like domains, a DNA-binding zinc-finger-like domain, an RNA-binding zinc-finger-like domain, and 2 coiled-coil protein-protein interaction domains. It also has a serine-arginine-rich domain, commonly found in proteins involved in RNA splicing. The protein was discovered using the CRE as bait in a yeast 1-hybrid assay. It was then shown to bind specifically to the CRE in vitro using gel shift assays. We have named the protein CRE-associated protein (CREAP). We show that it is widely expressed in human tissues but is highly expressed in several fetal tissues and in several regions of the adult brain. CREAP is closely related to 2 human proteins of unknown function. CREAP shows significant homology with a small nuclear ribonucleoprotein of yeast, Luc7p, involved in 5' splice site recognition. The 3 human CREAP proteins form a unique family with the potential to act as transcription factors that link to RNA processing.


Assuntos
Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/metabolismo , Proteínas Nucleares/metabolismo , Splicing de RNA/fisiologia , Homologia de Sequência de Aminoácidos , Sequência de Aminoácidos , Animais , Sequência de Bases , Sequência Consenso/genética , AMP Cíclico/genética , Proteínas de Ligação a DNA/genética , Proteínas Fúngicas/metabolismo , Perfilação da Expressão Gênica , Humanos , Zíper de Leucina/genética , Camundongos , Dados de Sequência Molecular , Proteínas Nucleares/química , Proteínas Nucleares/genética , Ligação Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Elementos Reguladores de Transcrição/genética , Alinhamento de Sequência
13.
J Clin Endocrinol Metab ; 89(5): 2312-8, 2004 May.
Artigo em Inglês | MEDLINE | ID: mdl-15126558

RESUMO

Placental CRH plays a major role in the mechanisms controlling human pregnancy and parturition. Understanding how placental CRH production is regulated is therefore of importance. Previously we have shown that placental expression of CRH peptide and mRNA are inhibited by estrogens, in contrast to the stimulatory effects of estrogen on hypothalamic CRH production. Our current study found that in placental cells cotransfected with a CRH promoter construct and an estrogen receptor-alpha expression vector results in a differential regulation whereby 17beta-estradiol (E2) decreased and the putative pure estrogen antagonist, ICI 182780, increased CRH promoter activity. Sequential deletion of the CRH promoter indicated that the region between -248 and -213 bp was essential for the effect of both E2 and ICI 182780. This region contains a consensus cAMP regulatory element (CRE) that is a requirement for E2- and ICI 182780-mediated activity because the CRE motif can confer E2 inhibition on a heterologous promoter such as rabbit beta-globin. Mutation of the CRE resulted in a complete reversal of E2 and ICI 182780 regulatory effects. In summary, our results demonstrate that a consensus CRE is required for the action of estrogen receptor ligands in human placental syncytiotrophoblast cells.


Assuntos
Hormônio Liberador da Corticotropina/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/fisiologia , Regulação da Expressão Gênica , Placenta/metabolismo , Receptores de Estrogênio/fisiologia , Trofoblastos/metabolismo , 8-Bromo Monofosfato de Adenosina Cíclica/farmacologia , Células Cultivadas/metabolismo , Regulação para Baixo/fisiologia , Estradiol/farmacologia , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Estrogênios/fisiologia , Feminino , Humanos , Ligantes , Placenta/citologia , Gravidez , Regiões Promotoras Genéticas/efeitos dos fármacos , Receptores de Estrogênio/metabolismo , Elementos de Resposta/genética
14.
Front Biosci ; 9: 32-9, 2004 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-14766341

RESUMO

Glucocorticoids inhibit corticotrophin releasing hormone (CRH) production in the hypothalamus but stimulate production from the placenta. To identify key elements regulating the CRH gene, mouse pituitary tumor-derived cells (AtT20 cells) were used as a hypothalamic model in an analysis of the CRH promoter. Two cAMP responsive elements were identified: (I) a consensus cAMP response element (CRE) and (II) a previously unrecognized caudal-type homeobox response element (CDXRE). Glucocorticoids inhibit only the component of cAMP-stimulation occurring via the CRE through an action involving a negative glucocorticoid response element (nGRE). We also identified two regions that, in the absence of the nGRE, can be stimulated by glucocorticoids: (I) the CRE and (II) a region between -213 to -99bps. Electrophoretic mobility shift assays identified binding of the transcription factors CREB and Fos at the CRE in AtT20 cells, whereas CREB and cJun were detected in placental cells. In addition, a novel CRE-binding transcription factor has been identified that is expressed in the brain and in placenta. A model is presented whereby CRH gene regulation is mediated via tissue specific expression of transcription factors.


Assuntos
Hormônio Liberador da Corticotropina/metabolismo , Regulação da Expressão Gênica/fisiologia , Elementos de Resposta/fisiologia , Animais , Encéfalo/metabolismo , Hormônio Liberador da Corticotropina/genética , Camundongos , Placenta/metabolismo , Células Tumorais Cultivadas
15.
Am J Physiol Regul Integr Comp Physiol ; 284(4): R965-82, 2003 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-12433673

RESUMO

Small lesions centered in the posterodorsal region of the medial amygdala resulted in excessive weight gains in female rats. Unilateral lesions were nearly as effective as bilateral lesions in the first 48 h after surgery (+21 to +32 g). Assessment of lesion damage was done by both qualitative evaluation and by a quantitative grid-point counting method. The critical sites for weight gain were the intra-amygdaloid bed nucleus of the stria terminalis and the posterodorsal medial amygdaloid nucleus. Incidental damage to the overlying globus pallidus was negatively related to weight gain. The cupric silver method for demonstrating axonal degeneration was applied to brains with obesity-inducing lesions. A dense pattern of degenerating terminals was found in the lateral septum, amygdala, ventral striatum, and ventromedial hypothalamus. Degeneration in the paraventricular nucleus of the hypothalamus was scarce or absent. Small retrograde tracer injections made in either the intra-amygdaloid bed nucleus of the stria terminalis or in the posterodorsal medial amygdaloid nucleus labeled cells in the amygdala, lateral septum, and hypothalamus, reciprocating the anterograde projections from the amygdala to these areas. The data suggest that subdivisions of the posterodorsal amygdala participate in the regulation of feeding in a manner that is similar to the better-known role of this part of the brain in mediating reproductive behavior. Although topographical differences may exist within the amygdaloid and hypothalamic subdivisions regulating these two sexually dimorphic behaviors, the relays engaged by feeding-related connections and those related to reproduction are remarkably parallel.


Assuntos
Tonsila do Cerebelo/patologia , Transporte Axonal , Obesidade/fisiopatologia , Tonsila do Cerebelo/fisiopatologia , Tonsila do Cerebelo/cirurgia , Animais , Gânglios da Base/patologia , Peso Corporal , Feminino , Hipotálamo/patologia , Vias Neurais/patologia , Ratos , Ratos Long-Evans , Núcleos Septais/patologia , Aumento de Peso
16.
Mol Cell Endocrinol ; 194(1-2): 19-28, 2002 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-12242024

RESUMO

Glucocorticoids inhibit corticotrophin releasing hormone (CRH) production in the hypothalamus but stimulate production from the placenta. We have sought to identify the key elements regulating the CRH gene. Mouse pituitary tumour-derived cells (AtT20 cells) were used in deletion and mutational analyses of the CRH promoter. Two cAMP responsive elements were identified: (I) a consensus cAMP response element (CRE) and (II) a previously unrecognised caudal-type homeobox response element (CDXRE). Glucocorticoids inhibit only the component of cAMP-stimulation occurring via the CRE through an action involving a negative glucocorticoid response element (nGRE). We also identified two regions that, in the absence of the nGRE, can be stimulated by glucocorticoids: (I) the CRE and (II) a region between -213 and -99 bps. Electrophoretic mobility shift assays (EMSAs) identified binding of the transcription factors CREB and Fos at the CRE in AtT20 cells while CREB and cJun were detected in placental cells. Tissue specific expression of transcription factors may mediate regulation of the CRH gene.


Assuntos
Hormônio Liberador da Corticotropina/genética , AMP Cíclico/farmacologia , Glucocorticoides/farmacologia , Regiões Promotoras Genéticas/genética , Animais , Hormônio Liberador da Corticotropina/efeitos dos fármacos , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Mutagênese Sítio-Dirigida , Hipófise/citologia , Placenta/citologia , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Proteínas Proto-Oncogênicas c-jun/genética , Proteínas Proto-Oncogênicas c-jun/metabolismo , Elementos de Resposta , Transfecção , Células Tumorais Cultivadas
17.
J Clin Endocrinol Metab ; 87(8): 3774-8, 2002 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-12161509

RESUMO

CRH and estrogens, produced by placental trophoblasts, have been suggested to play pivotal roles in the control of human parturition. Estrogen has been shown to affect hypothalamic CRH expression. Therefore, we evaluated 17 beta-estradiol (E2) in the regulation of CRH gene expression in placental cells. E2 inhibited CRH mRNA expression in a dose-dependent manner, which paralleled the decrease in CRH protein levels in culture media. A complete estrogen receptor (ER) antagonist, ICI 182780, not only blocked repression of CRH mRNA levels by E2, but up-regulated CRH mRNA and protein synthesis. An ER alpha-mixed agonist/antagonist and ER beta antagonist, 4-hydroxytamoxifen, also down-regulated CRH gene expression. Using quantitative RT-PCR, we found that placental trophoblasts express predominantly the ER alpha form of the receptor. Transient transfection assays conducted in the choriocarcinoma cell line JEG-3 demonstrated that E2 repressed CRH promoter activity, whereas the antagonist ICI 182780 up-regulated CRH promoter activity when ER alpha was cotransfected. These studies demonstrate that E2 represses placental CRH gene expression through an ER alpha-mediated mechanism. Estrogen may therefore modulate placental CRH production, influencing the rate of rise of maternal plasma CRH concentrations and potentially the length of gestation.


Assuntos
Hormônio Liberador da Corticotropina/genética , Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Estrogênios/farmacologia , Placenta/efeitos dos fármacos , Células Cultivadas , Hormônio Liberador da Corticotropina/análise , Estradiol/análogos & derivados , Receptor alfa de Estrogênio , Feminino , Fulvestranto , Expressão Gênica/efeitos dos fármacos , Humanos , Placenta/química , Placenta/citologia , Gravidez , Regiões Promotoras Genéticas/efeitos dos fármacos , RNA Mensageiro/análise , Receptores de Estrogênio/metabolismo
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