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1.
Am J Transplant ; 17(11): 2803-2809, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28744966

RESUMO

As the organ shortage continues to grow, the creation of social media communities by transplant hospitals and the public is rapidly expanding to increase the number of living donors. Social media communities are arranged in myriad ways and without standardization, raising concerns about transplant candidates' and potential donors' autonomy and quality of care. Social media communities magnify and modify extant ethical issues in deceased and living donation related to privacy, confidentiality, professionalism, and informed consent, and increase the potential for undue influence and coercion for potential donors and transplant candidates. Currently, no national ethical guidelines have been developed in the United States regarding the use of social media to foster organ transplantation. We provide an ethical framework to guide transplant stakeholders in using social media for public and patient communication about transplantation and living donation, and offer recommendations for transplant clinical practice and future research.


Assuntos
Consentimento Livre e Esclarecido/ética , Doadores Vivos , Transplante de Órgãos , Educação de Pacientes como Assunto , Guias de Prática Clínica como Assunto/normas , Mídias Sociais , Obtenção de Tecidos e Órgãos/ética , Humanos , Estados Unidos
2.
Am J Transplant ; 15(5): 1180-6, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25833728

RESUMO

New approaches to address the kidney scarcity in the United States are urgently needed. The greatest potential source of kidneys is from living donors. Proposals to offer financial incentives to increase living kidney donation rates remain highly controversial. Despite repeated calls for a pilot study to assess the impact of financial compensation on living kidney donation rates, many fear that financial incentives will exploit vulnerable individuals and cast the field of transplantation in a negative public light, ultimately reducing donation rates. This paper provides an ethical justification for conducting a pilot study of a federally regulated approach to providing financial incentives to living kidney donors, with the goal of assessing donors' perceptions.


Assuntos
Transplante de Rim/métodos , Doadores Vivos/ética , Motivação , Nefrectomia/economia , Insuficiência Renal/cirurgia , Obtenção de Tecidos e Órgãos/economia , Ética Médica , Humanos , Transplante de Rim/economia , Transplante de Rim/ética , Relações Médico-Paciente , Projetos Piloto , Projetos de Pesquisa , Coleta de Tecidos e Órgãos/economia , Coleta de Tecidos e Órgãos/ética , Obtenção de Tecidos e Órgãos/ética , Estados Unidos , Populações Vulneráveis
3.
Am J Transplant ; 14(5): 1164-72, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24725967

RESUMO

There are no minimally invasive diagnostic metrics for acute kidney transplant rejection (AR), especially in the setting of the common confounding diagnosis, acute dysfunction with no rejection (ADNR). Thus, though kidney transplant biopsies remain the gold standard, they are invasive, have substantial risks, sampling error issues and significant costs and are not suitable for serial monitoring. Global gene expression profiles of 148 peripheral blood samples from transplant patients with excellent function and normal histology (TX; n = 46), AR (n = 63) and ADNR (n = 39), from two independent cohorts were analyzed with DNA microarrays. We applied a new normalization tool, frozen robust multi-array analysis, particularly suitable for clinical diagnostics, multiple prediction tools to discover, refine and validate robust molecular classifiers and we tested a novel one-by-one analysis strategy to model the real clinical application of this test. Multiple three-way classifier tools identified 200 highest value probesets with sensitivity, specificity, positive predictive value, negative predictive value and area under the curve for the validation cohort ranging from 82% to 100%, 76% to 95%, 76% to 95%, 79% to 100%, 84% to 100% and 0.817 to 0.968, respectively. We conclude that peripheral blood gene expression profiling can be used as a minimally invasive tool to accurately reveal TX, AR and ADNR in the setting of acute kidney transplant dysfunction.


Assuntos
Biomarcadores/sangue , Perfilação da Expressão Gênica , Rejeição de Enxerto/sangue , Rejeição de Enxerto/classificação , Falência Renal Crônica/cirurgia , Transplante de Rim , Complicações Pós-Operatórias/genética , Adulto , Área Sob a Curva , Reações Falso-Negativas , Feminino , Seguimentos , Rejeição de Enxerto/etiologia , Humanos , Falência Renal Crônica/complicações , Masculino , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Complicações Pós-Operatórias/sangue , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Sensibilidade e Especificidade
5.
Arch Physiol Biochem ; 113(1): 13-24, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17522981

RESUMO

There seems to be an association between increased concentrations of malonyl coenzyme A (malonyl CoA) in skeletal muscle and diabetes and/or insulin resistance. The purpose of the current study was to test the hypothesis that treatments designed to manipulate malonyl CoA concentrations would affect insulin-stimulated glucose transport in cultured C2C12 myotubes. We assessed glucose transport after polyamine-mediated delivery of malonyl CoA to myotubes, after incubation with dichloroacetate (which reportedly increases malonyl CoA levels), or after exposure of myotubes to 2-bromopalmitate, a carnitine palmitoyl transferase I inhibitor. All three of these treatments prevented stimulation of glucose transport by insulin. We also assayed glucose transport after 30 min of inhibition of acetyl coenzyme A carboxylase (ACC), the enzyme which catalyzes the production of malonyl CoA. Three unrelated ACC inhibitors (diclofop, clethodim, and Pfizer CP-640186) all enhanced insulin-stimulated glucose transport. However, none of the treatments designed to manipulate malonyl CoA concentrations altered markers of proximal insulin signaling through Akt. The findings support the hypothesis that acute changes in malonyl CoA concentrations affect insulin action in muscle cells but suggest that the effects do not involve alterations in proximal insulin signaling.


Assuntos
Glucose/metabolismo , Insulina/fisiologia , Malonil Coenzima A/fisiologia , Fibras Musculares Esqueléticas/enzimologia , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Transporte Biológico Ativo/fisiologia , Bovinos , Linhagem Celular , Ácido Dicloroacético/farmacologia , Camundongos , Fibras Musculares Esqueléticas/efeitos dos fármacos , Fibras Musculares Esqueléticas/metabolismo
6.
Endocrinology ; 141(10): 3898-907, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11014247

RESUMO

This study investigated whether neonatal exposure of male rats to estrogenic compounds altered pubertal spermatogenesis (days 18 and 25) and whether the changes observed resulted in long-term changes in testis size, mating, or fertility (days 90-100). Rats were treated neonatally with a range of doses (0.01-10 microg) of diethylstilbestrol (DES; administered on alternate days from days 2-12), a high dose of octylphenol (OP; 2 mg administered daily from days 2-12) or bisphenol A (Bis-A; 0.5 mg administered daily from days 2-12), or vehicle, while maintained on a standard soy-containing diet. The effect on the same parameters of rearing control animals on a soy-free diet was also assessed as was the effect of administering such animals genistein (4 mg/kg/day daily from days 2-18). Testis weight, seminiferous tubule lumen formation, the germ cell apoptotic index (apoptotic/viable germ cell nuclear volume), and spermatocyte nuclear volume per unit Sertoli cell nuclear volume were used to characterize pubertal spermatogenesis. Compared with (soy-fed) controls, DES administration caused dose-dependent retardation of pubertal spermatogenesis on day 18, as evidenced by decreases in testis weight, lumen formation, and spermatocyte nuclear volume per unit Sertoli cell and elevation of the germ cell apoptotic index. However, the two lowest doses of DES (0.1 and 0.01 microg) significantly increased spermatocyte nuclear volume per unit Sertoli cell. Similarly, treatment with either OP or Bis-A significantly advanced this and some of the other aspects of pubertal spermatogenesis. Maintenance of control animals on a soy-free diet also significantly advanced lumen formation and spermatocyte nuclear volume per unit Sertoli cell compared with controls fed a soy-containing diet. Administration of genistein reversed the stimulatory effects of a soy-free diet and significantly retarded most measures of pubertal spermatogenesis. In general, plasma FSH levels in the treatment groups changed in parallel to the spermatogenic changes (reduced when pubertal spermatogenesis retarded, increased when pubertal spermatogenesis advanced). By day 25, although the changes in FSH levels largely persisted, all of the stimulatory effects on spermatogenesis seen on day 18 in the various treatment groups were no longer evident. In adulthood, testis weight was decreased dose dependently in rats treated neonatally with DES, but only the lowest dose group (0.01 microg) showed evidence of mating (3 of 6) and normal fertility (3 litters). Animals treated neonatally with OP or Bis-A had normal or increased (Bis-A) testis weights and exhibited reasonably normal mating/fertility. Animals fed a soy-free diet had significantly larger testes than controls fed a soy-containing diet, and this difference was confirmed in a much larger study of more than 24 litters, which also showed a significant decrease in plasma FSH levels and a significant increase in body weight in the males kept on a soy-free diet. Neonatal treatment with genistein did not alter adult testis weight, and although most males exhibited normal mating and fertility, a minority did not mate or were infertile. It is concluded that 1) neonatal exposure of rats to low levels of estrogens can advance the first wave of spermatogenesis at puberty, although it is unclear whether this is due to direct effects of the estrogen or to associated elevation of FSH levels; 2) the effect of high doses of OP and Bis-A on these processes is essentially benign; and 3) the presence or absence of soy or genistein in the diet has significant short-term (pubertal spermatogenesis) and long-term (body weight, testis size, FSH levels, and possibly mating) effects on males.


Assuntos
Animais Recém-Nascidos/fisiologia , Estrogênios/farmacologia , Fertilidade/efeitos dos fármacos , Espermatogênese/efeitos dos fármacos , Testículo/anatomia & histologia , Envelhecimento/fisiologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Apoptose/fisiologia , Dieta , Exposição Ambiental , Hormônio Foliculoestimulante/sangue , Inibinas/sangue , Masculino , Tamanho do Órgão , Ratos , Ratos Wistar , Túbulos Seminíferos/efeitos dos fármacos , Células de Sertoli/citologia , Glycine max , Testículo/citologia , Testículo/efeitos dos fármacos , Testículo/fisiologia
7.
Endocrinology ; 139(9): 3935-45, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-9724049

RESUMO

Recent data suggest that estrogens play a role in regulating fluid resorption from the efferent ducts, though the biochemical mechanisms involved are unknown. The present study has used immunocytochemistry to localize a water channel protein, Aquaporin-1 (AQP-1), to the efferent ducts of male rats and marmoset monkeys from perinatal life through to adulthood and has then investigated its potential hormonal regulation in neonatal/peripubertal life, via administration of a GnRH antagonist (GnRHa) or diethylstilbestrol (DES) to rats. AQP-1 was immunoexpressed intensely in the apical brush border of the epithelium lining the efferent ducts at all ages studied, from late fetal life through puberty to adulthood. In the marmoset, but not the rat, AQP-1 was also expressed in the epithelium of the rete testis. Once the cell types within the efferent duct epithelium had differentiated, it was clear that only nonciliated cells of the rat localized AQP-1. When gonadotropin secretion was suppressed in rats by neonatal administration of GnRHa, immunoexpression of AQP-1 at age 18 and 25 days was virtually unchanged in intensity, though the efferent ducts were reduced in size. In contrast, when DES was administered neonatally to rats (up to day 12), immunoexpression of AQP-1 was reduced at day 10, virtually abolished at day 18, reduced markedly at day 25 and to a small extent at day 35; these findings were confirmed by Western blot analysis at day 18. The DES-induced decrease in immunoexpression of AQP-1 was accompanied by pronounced distension of the efferent ducts and rete, consistent with reduced fluid resorption. The epithelial cells of the efferent ducts in DES-treated rats were cuboidal rather than columnar in shape as in controls and were reduced significantly in height compared with controls at all ages through to adulthood. These findings suggest that estrogens may play a role in regulating fluid resorption from the efferent ducts during fetal/neonatal development and/or a role in the gross and functional development of the efferent ducts and rete testis. The present data also suggest that AQP-1 is one of the elements involved in the regulation of fluid resorption in the efferent ducts. The importance of fluid flow in fetal/neonatal development of the excurrent duct system of the male is also suggested by these observations.


Assuntos
Envelhecimento/metabolismo , Animais Recém-Nascidos/metabolismo , Aquaporinas , Líquidos Corporais/metabolismo , Epididimo/metabolismo , Estrogênios/fisiologia , Canais Iônicos/metabolismo , Absorção/fisiologia , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Aquaporina 1 , Western Blotting , Callithrix , Dietilestilbestrol/farmacologia , Epididimo/anatomia & histologia , Epididimo/efeitos dos fármacos , Hormônio Liberador de Gonadotropina/agonistas , Imuno-Histoquímica , Canais Iônicos/fisiologia , Masculino , Ratos , Ratos Wistar , Rede do Testículo/efeitos dos fármacos
8.
Endocrinology ; 140(11): 5364-73, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10537168

RESUMO

This study aimed to identify the mechanism(s) for impairment of spermatogenesis in adulthood in rats treated neonatally with estrogens. Rats were treated (days 2-12) with 10, 1, or 0.1 microg diethylstilbestrol (DES), 10 microg ethinyl estradiol (EE), 10 mg/kg of a GnRH antagonist (GnRHa), or vehicle and killed in adulthood. DES/EE caused dose-dependent reductions in testis weight, total germ cell volume per testis, and Sertoli cell volume per testis. Sertoli cell number at 18 days of age in DES-treated rats was reduced dose dependently. GnRHa treatment caused changes in these parameters similar to those in rats treated with 10 microg DES. Plasma FSH levels were elevated (P < 0.001) to similar levels in all treatment groups regardless of differences in Sertoli cell number and levels of inhibin B; the latter reflected Sertoli cell number, but levels were disproportionately reduced in animals treated with high doses of DES/EE. Neonatal estrogen treatment, but not GnRHa, caused dose-dependent reductions (40-80%) in plasma testosterone levels in adulthood, but did not alter LH levels. Preliminary evidence suggests that the decrease in testosterone levels in estrogen-treated rats is not due to reduced Leydig cell volume per testis. GnRHa-treated rats exhibited a significant increase in germ cell volume per Sertoli cell and a reduction in germ cell apoptosis, probably because of the raised FSH levels. Despite similar raised FSH levels, rats treated with DES (10 or 1 microg) or EE (10 microg) had reduced germ cell volume/Sertoli cell and increased germ cell apoptosis, especially when compared with GnRHa-treated animals. The latter changes were associated with an increase in lumen size per testis, indicative of impaired fluid resorption from the efferent ducts, resulting in fluid accumulation in the testis. Rats treated neonatally with 0.1 microg DES showed reduced germ cell apoptosis comparable to that in GnRHa-treated animals. The changes in apoptotic rate among treatment groups occurred across all stages of the spermatogenic cycle. It is concluded that 1) neonatal estrogen treatment results in dose-dependent alterations in Sertoli cell numbers, germ cell volume, efficiency of spermatogenesis, and germ cell apoptosis in adulthood; 2) the relatively poor spermatogenesis in estrogen-treated animals is most likely due to altered testis fluid dynamics and/or altered Sertoli cell function; 3) as indicated by FSH (LH) and testosterone levels, the hypothalamic-pituitary axis and Leydig cells are probably more sensitive than the Sertoli cells to reprogramming by estrogens neonatally; and 4) elevated FSH levels in adulthood may improve the efficiency of spermatogenesis.


Assuntos
Animais Recém-Nascidos , Estrogênios/farmacologia , Hormônio Foliculoestimulante/sangue , Células de Sertoli , Espermatogênese/efeitos dos fármacos , Testosterona/sangue , Animais , Apoptose/efeitos dos fármacos , Contagem de Células , Dietilestilbestrol/farmacologia , Estrogênios/administração & dosagem , Etinilestradiol/farmacologia , Hormônio Liberador de Gonadotropina/antagonistas & inibidores , Antagonistas de Hormônios/farmacologia , Inibinas/sangue , Masculino , Oligopeptídeos/farmacologia , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar , Testículo/crescimento & desenvolvimento
9.
Endocrinology ; 142(2): 874-86, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11159861

RESUMO

This study in rats sought to 1) characterize immunoexpression of estrogen receptor alpha (ERalpha) and ERss in the efferent ducts, epididymis, and vas deferens during postnatal development; 2) establish whether ER expression changed after neonatal treatment with diethylstilbestrol (DES); and 3) determine whether ER changes coincided with abnormal epididymal/vas development. Rats were administered 10 microg DES or vehicle on days 2, 4, 6, 8, 10, and 12 and were sampled on days 10, 18, 25, 35, and 90+. At all ages, ERalpha was immunoexpressed intensely in the efferent ducts. On day 10, immunoexpression of ERalpha was absent from the epididymis and vas, but was detectable on day 18 in epithelial cells in the caput, corpus, and proximal cauda. Epithelial expression of ERalpha was absent from the distal cauda and in the proximal and distal vas was confined to a band of periductal stromal cells. Thus, on day 18, the site of ERalpha expression delineated the epididymis-vas boundary. On days 25-35, epithelial expression of ERalpha was absent, but stromal expression persisted in the vas and distal cauda. In adults, immunoexpression of ERalpha in the epididymis and vas was absent. In contrast, ERbeta was immunoexpressed in epithelial cells and some stromal cells in the efferent ducts, epididymis, and vas at all ages. In the vas, stromal expression of ERalpha and ERbeta was in different layers. DES treatment caused 1) underdevelopment of the epididymal duct and reduced epithelial height in epididymis and vas; 2) coiling of the extraepididymal vas; 3) thickening of the periductal actin-free stromal layer in the distal cauda and vas; and 4) reduced cell proliferation on day 18 in the epididymis and vas, based on incorporation of bromodeoxyuridine, especially in the epithelium. These changes coincided with abnormalities in cell- and region-specific immunoexpression of ERalpha, but not ERbeta. Thus, in DES-treated rats on day 18, epithelial expression of ERalpha occurred in all regions of the epididymis and vas instead of being confined to the caput, corpus, and proximal cauda as in controls. Similarly, stromal ERalpha expression in the vas of DES-treated rats was not confined to a periductal layer as in controls, but occurred diffusely in the muscle layer. It is suggested that 1) estrogens play a role in peripubertal development of the epididymis and vas; 2) the cellular site of expression of ERalpha either plays a role in or reflects demarcation of the epididymal/vas boundary; and 3) blurring of this boundary in DES-treated rats coincides with altered ERalpha immunoexpression.


Assuntos
Envelhecimento/metabolismo , Animais Recém-Nascidos/metabolismo , Dietilestilbestrol/farmacologia , Epididimo/metabolismo , Estrogênios não Esteroides/farmacologia , Receptores de Estrogênio/metabolismo , Ducto Deferente/metabolismo , Animais , Animais Recém-Nascidos/crescimento & desenvolvimento , Divisão Celular/efeitos dos fármacos , Epididimo/efeitos dos fármacos , Epididimo/crescimento & desenvolvimento , Epididimo/patologia , Receptor alfa de Estrogênio , Receptor beta de Estrogênio , Imuno-Histoquímica , Masculino , Ratos , Ratos Wistar , Distribuição Tecidual , Ducto Deferente/efeitos dos fármacos , Ducto Deferente/crescimento & desenvolvimento , Ducto Deferente/patologia
10.
J Clin Endocrinol Metab ; 85(4): 1498-504, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10770188

RESUMO

The aim of this study was to evaluate in premenopausal women (10 sedentary obese women) the effects of 10 days of exercise on the suppression of whole body and regional lipolysis by insulin. Lipolysis was determined using 2H5-glycerol infusion and microdialysis of sc adipose tissue during a two-stage hyperinsulinemic-euglycemic clamp [10 (LO) and 20 (MO) mU/m x min]. Microdialysis probes were positioned in abdominal and femoral sc adipose tissue to monitor interstitial glycerol and blood flow. Basal plasma glycerol was 86.7 +/-17.0 and 100.3 +/- 19.8 micromol/L before and after training, respectively (P < 0.05). Plasma glycerol was suppressed to a greater extent after [to 47 +/- 5% (LO) and 42 +/- 5% (MO) of basal] than before [to 62 +/- 8% (LO) and 55 +/- 8% (MO) of basal] training. The rate of appearance of glycerol was suppressed to 49 +/- 7% and 40 +/- 5% of basal during LO and to 38 +/- 5% and 30 +/- 4% of basal during MO (P < 0.05) before and after training, respectively. There were no differences in the suppression of lipolysis in abdominal as well as femoral sc adipose tissue as evidenced by similar reductions in dialysate glycerol levels before and after training in each of these tissues. The results indicate that the antilipolytic response to insulin can be improved through endurance exercise training. Intraabdominal adipose tissue or skeletal muscle may be the site of improved antilipolytic response to insulin after training, as improvement was not evident in abdominal or femoral sc adipose tissue.


Assuntos
Exercício Físico , Insulina/farmacologia , Lipólise/efeitos dos fármacos , Resistência Física , Tecido Adiposo/irrigação sanguínea , Tecido Adiposo/metabolismo , Glicemia/metabolismo , Composição Corporal , Deutério , Feminino , Técnica Clamp de Glucose , Glicerol/sangue , Humanos , Microdiálise , Obesidade/metabolismo , Consumo de Oxigênio , Pré-Menopausa
11.
J Clin Endocrinol Metab ; 84(11): 3886-95, 1999 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-10566624

RESUMO

The aim of this study was to evaluate in premenopausal women (six endurance-trained nonobese, six sedentary nonobese, and five sedentary obese) the suppression of whole body and regional lipolysis by insulin. Lipolysis was determined using 2H5-glycerol infusion and microdialysis of sc adipose tissue (AT) during a two-stage [6-10 (low; LO) and 12-20 (moderate; MOD) mU/m x min] hyperinsulinemic-euglycemic clamp. Microdialysis probes were positioned in abdominal and femoral sc AT to monitor interstitial glycerol and nutritive blood flow. Basal plasma glycerol was 102 +/- 9, 52 +/- 6, and 143 +/- 30 micromol/L in endurance-trained nonobese, sedentary nonobese, and sedentary obese, respectively (P < 0.05, sedentary nonobese < endurance-trained nonobese, sedentary obese). The plasma glycerol concentration was decreased (P < 0.05) to a greater extent in endurance-trained nonobese and sedentary nonobese [both to approximately 50% (LO) and approximately 45% (MOD) of basal] than in sedentary obese [to 72% (LO) and 63% (MOD) of basal]. The rate of appearance of glycerol was suppressed to 36 +/- 7%, 44 +/- 10%, and 62 +/- 7% of basal during LO in endurance-trained nonobese, sedentary nonobese, and sedentary obese, respectively (P < 0.05, endurance-trained nonobese < sedentary obese), and to 34 +/- 3%, 36 +/- 5%, and 53 +/- 8% of basal during MOD, respectively (P < 0.05, endurance-trained nonobese < sedentary obese). There were no between-group differences in the suppression of lipolysis in abdominal sc AT, as evidenced by similar reductions in dialysate glycerol levels [all to approximately 65% (LO) and approximately 55% (MOD) of basal]. Femoral dialysate glycerol was reduced (P < 0.05) more in sedentary nonobese and endurance-trained nonobese (to approximately 75% of basal) than in sedentary obese (to 90% of basal) during LO, but to a similar extent (to approximately 60% of basal) in all groups during MOD. The results indicate that the sedentary obese women had whole body resistance to the suppression of lipolysis by insulin. Intraabdominal AT may be the site of resistance, as resistance was not evident in abdominal or femoral sc AT.


Assuntos
Exercício Físico/fisiologia , Insulina/farmacologia , Lipólise/efeitos dos fármacos , Obesidade/metabolismo , Abdome , Tecido Adiposo/irrigação sanguínea , Adulto , Glicemia/metabolismo , Composição Corporal , Constituição Corporal , Deutério , Feminino , Fêmur , Técnica Clamp de Glucose , Glicerol/sangue , Humanos , Insulina/administração & dosagem , Insulina/sangue , Cinética , Microdiálise , Consumo de Oxigênio , Resistência Física
12.
J Clin Endocrinol Metab ; 84(10): 3726-31, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10523021

RESUMO

Insulin-induced leptinemia in humans appears to be blunted by insulin resistance. We therefore examined the relationship between insulin action and plasma leptin by monitoring regional and whole body lipolysis and plasma leptin levels in 15 premenopausal women (body fat range, 14-59%) during a two-stage euglycemic clamp (insulin was infused 90 min each at 6-10 and 12-20 mU/m2 x min). Microdialysis probes were placed in abdominal and femoral sc adipose tissue. Subjects were given a primed, constant infusion of a stable isotope tracer (2H5-glycerol), and plasma glycerol isotope enrichments were analyzed by mass spectrometry to determine glycerol kinetics. Although there was no mean change in plasma leptin during the clamp (baseline, 16.6 +/- 4.5 ng/mL; final, 16.3 +/- 4.3 ng/mL), there was large interindividual variability in the changes in plasma leptin (range, -18% to +19%). Changes in plasma leptin during the clamp stages were correlated with abdominal dialysate glycerol concentrations (r = -0.44; P < 0.05), but not femoral dialysate glycerol concentrations (r = -0.15), the rate of appearance of glycerol in plasma (r = 0.005), or plasma insulin levels (r = 0.16). The results suggest that insulin-induced changes in plasma leptin are more related to the lipolytic state (i.e. low leptin response when lipolysis is high) of abdominal sc adipose tissue than that of other fat depots.


Assuntos
Abdome , Tecido Adiposo/metabolismo , Insulina/farmacologia , Leptina/sangue , Lipólise , Adulto , Circulação Sanguínea/fisiologia , Feminino , Glicerol/sangue , Humanos , Hiperinsulinismo/sangue , Hiperinsulinismo/induzido quimicamente , Hiperinsulinismo/metabolismo , Hiperinsulinismo/fisiopatologia , Insulina/sangue , Fatores de Tempo
13.
J Clin Endocrinol Metab ; 52(6): 1057-61, 1981 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-6262360

RESUMO

Spironolactone, a mineralocorticoid antagonist, may also inhibit aldosterone biosynthesis. In vitro studies suggest that spironolactone and its major metabolites inhibit adrenal 18- and 11 beta-hydroxylase activity. We examined various adrenal corticosteroids and their precursors, plasma renin activity, aldosterone excretion rate, and serum and urine electrolytes in normal subjects before and on days 5 and 10 of spironolactone administration (400 mg/day). Plasma corticosteroids were also examined 60 min after ACTH (Cortrosyn) 0.25-mg iv bolus. RIAs were performed after extensive chromatography; there was no interference of spironolactone and its metabolites in the assays. All studies were performed in supine subjects in metabolic balance on a constant 120-meq sodium intake. Plasma renin activity was increased (P less than 0.001) on both days 5 and 10 of spironolactone. Plasma aldosterone (PA) and the aldosterone excretion rate increased (P less than 0.01) on day 5 of spironolactone but decreased (P less than 0.01) from day 5 to 10. Both 11-deoxycorticosterone and 18-hydroxycorticosterone were increased from day 5 to 10. Corticosterone, progesterone, and dehydroepiandrosterone did not increase significantly during spironolactone administration. Incremental PA response to ACTH was less than control on day 10 of spironolactone, but other corticosteroid responses to ACTH were not different during control and days 5 or 10 of treatment. Reduction in PA and further elevation in its precursors during the second 5-day period of spironolactone therapy suggests inhibition of aldosterone biosynthesis during this phase of treatment in normal man. The disproportionate increments in 18-hydroxycorticosterone and 11-deoxycorticosterone suggest biosynthetic inhibition at the 18-dehydrogenase and 11 beta-hydroxylase sites.


Assuntos
Corticosteroides/sangue , Espironolactona , 18-Hidroxicorticosterona/sangue , Hormônio Adrenocorticotrópico , Adulto , Aldosterona/metabolismo , Desoxicorticosterona/sangue , Feminino , Humanos , Cinética , Masculino , Potássio/metabolismo , Progesterona/sangue , Renina/sangue , Sódio/metabolismo
14.
Transplantation ; 70(1): 100-5, 2000 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-10919582

RESUMO

BACKGROUND: Preexisting renal dysfunction has been reported to significantly increase the morbidity and mortality associated with orthotopic liver transplantation (OLT). OLT alone has been recommended for adults and children with end-stage liver disease and reversible causes of renal failure (i.e., hepatorenal syndrome), whereas combined liver and kidney transplantation (LKT) has been shown to be an effective treatment for adults with combined end-stage liver and kidney disease. The purpose of this study was to examine the role of LKT in children. METHODS: Between October of 1984 and 1997, 385 children less than 18 years of age underwent OLT at the University of Chicago. During this same time period 12 patients underwent LKT. Data were gathered by retrospective review of the patients medical records and by interviews conducted with the patients' families. RESULTS: Actuarial patient survival was comparable for children who underwent OLT alone and LKT (69% versus 67% at 5 years). All allograft losses in the LKT group were the result of patient death and occurred within the first 90 postoperative days. Factors associated with decreased patient survival included severity of illness as reflected by United Network of Organ Sharing status and LKT after failed OLT or cadaveric renal transplant. CONCLUSIONS: In children with concomitant endstage liver and kidney disease, LKT can be considered an effective therapeutic option in selected patients. Long-term patient survival in patients undergoing LKT is comparable to that of patients with normal renal function undergoing OLT alone.


Assuntos
Transplante de Rim , Transplante de Fígado , Criança , Pré-Escolar , Rejeição de Enxerto , Humanos , Lactente , Transplante de Rim/mortalidade , Transplante de Fígado/mortalidade , Transplante Homólogo
15.
J Endocrinol ; 156(3): R13-7, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9582517

RESUMO

The identification of a second oestrogen receptor (beta) has prompted a re-evaluation of the potential sites of action of oestrogens. The aim of the present study was to characterize immunoexpression of ER beta expression in the testis to complement earlier data which had demonstrated that expression of ER alpha is confined to testicular interstitial Leydig cells. In all testes studied, including those from both fetal (day 20.5 p.c.) and adult rats, ER beta was found to be expressed in multiple cell types. Sertoli cell nuclei were immunopositive at all ages. In adult testes expression in Sertoli cells was not stage dependent and was unaffected by ablation of Leydig cells. In fetal testes ER beta was also expressed in peritubular cells, fetal Leydig cells and gonocytes. In the pubertal and adult testis ER beta was detected in the nuclei of spermatogonia and most pachytene spermatocytes. Weak immunopositive staining was present in the cytoplasm of spermatocytes undergoing the second meiotic division. In conclusion the widespread expression of ER beta in the testis is consistent with a role for oestrogens in modulating spermatogenesis, and hence fertility, in the male.


Assuntos
Receptores de Estrogênio/análise , Testículo/química , Animais , Núcleo Celular/química , Imuno-Histoquímica , Células Intersticiais do Testículo/química , Masculino , Ratos , Células de Sertoli/química , Espermatozoides/química , Testículo/embriologia
16.
J Endocrinol ; 153(3): 485-95, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9204003

RESUMO

The sites of action and the physiological role of oestrogens in the male reproductive tract are poorly understood. We have undertaken a systematic study of the immunoexpression of oestrogen receptor-alpha (ER alpha) in the male rat from late fetal life through to adulthood and compared the findings with results obtained in the marmoset monkey (Callithrix jacchus) from neonatal to adult life. The testes, rete testis, efferent ducts and epididymis were examined from normal male rats (aged 4, 8, 10, 15, 20, 25, 38, 48 and 90 days) and from male rat fetuses on days 17.5 and 18.5 of gestation; comparable tissues were examined from neonatal, infantile, peripubertal and adult marmosets aged 8, 18-24, 54-62 and 92-112 weeks respectively. Immunolocalisation of ER alpha used antigen retrieval and a monoclonal antibody directed to the N-terminus, which had proved superior to six other antisera tested. ER alpha was immunoexpressed in interstitial cells, including the fetal/ neonatal generation of Leydig cells, in both the rat and marmoset. In the rat, the adult generation of Leydig cells were also immunopositive for ER alpha whereas the comparable cells in the marmoset were only weakly immunopositive. ER alpha was not expressed in Sertoli cells, peritubular myoid cells, blood vessels or germ cells at any time in either species. In late fetal life in the rat, ER alpha was immunoexpressed in cells surrounding the mesonephric tubules, whereas postnatally it was expressed in the epithelium of the rete testis and efferent ducts at all ages from 4 to 90 days; this immunoexpression was most pronounced in the efferent ducts. In the marmoset, the efferent ducts, but not the rete testis, also showed intense immunoexpression of ER alpha. Apart from sporadic immunostaining for ER alpha in the epididymal duct of the rat in the neonatal period, the caput, corpus and cauda epididymis were negative for immunoexpression of ER alpha at all ages in both species. These findings suggest that the main actions of oestrogens in the male reproductive tract, mediated by ER alpha, are related to the development and function of the efferent ducts and the Leydig cells. In consideration of data from this and previous studies of oestrogen binding, we predict possible sites of expression of other oestrogen receptors (e.g. ER beta) in Sertoli cells and the epididymis. Interactive effects, related to the relative levels of androgens and oestrogens, could be physiologically important in the excurrent ducts of the adult testis.


Assuntos
Receptores de Estrogênio/análise , Testículo/química , Fatores Etários , Animais , Animais Recém-Nascidos , Callithrix , Epididimo/química , Epididimo/embriologia , Epididimo/crescimento & desenvolvimento , Epitélio/química , Imuno-Histoquímica , Células Intersticiais do Testículo/química , Masculino , Ratos , Ratos Wistar , Rede do Testículo/química , Rede do Testículo/embriologia , Rede do Testículo/crescimento & desenvolvimento , Testículo/embriologia , Testículo/crescimento & desenvolvimento
17.
Environ Health Perspect ; 107(5): 397-405, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10210696

RESUMO

Neonatal exposure to diethylstilbestrol (DES) can alter the structure of the testicular excurrent ducts in rats. We characterized these changes according to dose and time posttreatment and established whether potent estrogens (ethinyl estradiol), environmental estrogens (genistein, octylphenol, bisphenol A, parabens), and tamoxifen induce such changes. Rats were administered these compounds neonatally and assessed at several time points during (day 10, or day 18 for some treatments) and after (days 18, 25, 35, and 75) the treatment period to detect any changes in testis weight, distension of the rete testis and efferent ducts, epithelial cell height in the efferent ducts, and immunoexpression of the water channel aquaporin-1 (AQP-1). Treatment with DES (10, 1, or 0.1 microg/injection; equivalent to 0.37, 0.037, or 0.0037 mg/kg/day, respectively) induced dose-dependent changes in testis weight and all parameters. These effects were most pronounced at days 18 and 25 and appeared to lessen with time, although some persisted into adulthood. Neonatal treatment with ethinyl estradiol (10 microg/injection; equivalent to 0.37 mg/kg/day) caused changes broadly similar to those induced by 10 mg DES. Administration of tamoxifen (2 mg/kg/day) caused changes at 18 days that were similar to those induced by 1 microg DES. Treatment with genistein (4 mg/kg/day), octylphenol (2 mg/injection; equivalent to 150 mg/kg/day), or bisphenol A (0.5 mg/injection; equivalent to 37 mg/kg/day) caused minor but significant (p<0.05) decreases in epithelial cell height of the efferent ducts at days 18 and/or 25. In animals that were followed through to 35 days and/or adulthood, these changes were no longer obvious; other parameters were either unaffected or were affected only marginally and transiently. Administration of parabens (2 mg/kg/day) had no detectable effect on any parameter at day 18. To establish whether these effects of estrogens were direct or indirect (i.e., resulting from reduced follicle-stimulating hormone/luteinizing hormone secretion), the above end points were assessed in animals in which gonadotropin secretion was suppressed neonatally by administration of a gonadotropin-releasing hormone antagonist. This treatment permanently reduced testis weight, but did not affect any of the other end points, apart from a minor transient reduction in efferent duct epithelial cell height at 18 days. This study suggests that structural and functional (expression of AQP-1) development of the excurrent ducts is susceptible to impairment by neonatal estrogen exposure, probably as a consequence of direct effects. The magnitude and duration of adverse changes induced by treatment with a range of estrogenic compounds was broadly comparable to their estrogenic potencies reported from in vitro assays.


Assuntos
Estrogênios/farmacologia , Maturidade Sexual , Testículo/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Compostos Benzidrílicos , Dietilestilbestrol/farmacologia , Congêneres do Estradiol/farmacologia , Antagonistas de Estrogênios/farmacologia , Estrogênios não Esteroides/farmacologia , Etinilestradiol/farmacologia , Genisteína/farmacologia , Masculino , Parabenos/farmacologia , Fenóis/farmacologia , Ratos , Ratos Wistar , Tamoxifeno/farmacologia , Testículo/crescimento & desenvolvimento
18.
Environ Health Perspect ; 103(12): 1136-43, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8747020

RESUMO

This study assessed whether exposure of male rats to two estrogenic, environmental chemicals, 4-octylphenol (OP) and butyl benzyl phthalate (BBP) during gestation or during the first 21 days of postnatal life, affected testicular size or spermatogenesis in adulthood (90-95 days of age). Chemicals were administered via the drinking water or concentrations of 10-1000 micrograms/l (OP) or 1000 micrograms/l (BBP), diethylstilbestrol (DES; 100 micrograms/l) and an octylphenol polyethoxylate (OPP; 1000 micrograms/l), which is a weak estrogen or nonestrogenic in vitro, were administered as presumptive positive and negative controls, respectively. Controls received the vehicle (ethanol) in tap water. In study 1, rats were treated from days 1-22 after births in studies 2 and 3, the mothers were treated for approximately 8-9 weeks, spanning a 2-week period before mating throughout gestation and 22 days after giving birth. With the exception of DES, treatment generally had no major adverse effect or body weight: in most instances, treated animals were heavier than controls at day 22 and at days 90-95. Exposure to OP, OPP, or BBP at a concentration of 1000 micrograms/1 resulted in a small (5-13%) but significant (p < 0.01 or p < 0.0001) reduction in mean testicular size in studies 2 and 3, an effect that was still evident when testicular weight was expressed relative to body, weight or kidney weight. The effect of OPP is attributed to its metabolism in vivo to OP. DES exposure caused similar reductions in testicular size but also caused reductions in body weight, kidney weight, and litter size. Ventral prostate weight was reduced significantly in DES-treated rats and to minor extent in OP-treated rats. Comparable but more minor effects of treatment with DES or OP on testicular size were observed in study 1. None of the treatments had any adverse effect on testicular morphology or on the cross-sectional area of the lumen or seminiferous epithelium at stages VII-VIII of the spermatogenic cycle, but DES, OP, and BBP caused reductions of 10-21% (p < 0.05 to p < 0.001) in daily sperm production. Humans are exposed to phthalates, such as BBP, and to alkylphenol polyethoxylates, such as OP, but to what extent is unknown. More detailed studies are warranted to assess the possible risk to the development of the human testis from exposure to these and other environmental estrogens.


Assuntos
Dietilestilbestrol/toxicidade , Estrogênios não Esteroides/toxicidade , Estrogênios/agonistas , Fenóis/toxicidade , Ácidos Ftálicos/toxicidade , Efeitos Tardios da Exposição Pré-Natal , Espermatogênese/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Animais Lactentes , Feminino , Lactação , Masculino , Gravidez , Ratos , Ratos Wistar , Testículo/patologia
19.
Environ Health Perspect ; 109(12): 1227-35, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11748029

RESUMO

In this study we evaluated the effect of manipulating the estrogen and androgen environment of the neonatal male rat on subsequent immunoexpression of sex steroid receptors in the seminal vesicles (SVs) at age 18 days. The aim was to establish to what extent such changes were associated with and predictive of changes in SV structure/composition. Treatments were either diethylstilbestrol (DES; 10, 1, or 0.1 microg/injection), ethinyl estradiol (EE; 10 microg/injection), tamoxifen (2 mg/kg/day), flutamide (50 mg/kg), a gonadotropin-releasing hormone antagonist (GnRHa; 10 mg/kg), genistein (4 mg/kg/day), octylphenol (2 mg/injection), or bisphenol A (0.5 mg/injection). Compared with controls, treatment with DES (10 microg) induced loss of epithelial and stromal androgen receptor (AR) immunoexpression coincident with induction of stromal progesterone receptor (PR) immunoexpression and upregulation of stromal immunoexpression of estrogen receptor-alpha (ERalpha). These changes were associated with gross distortion (increase) of the normal stromal:epithelial tissue proportions in the SVs. DES (1 microg) and EE induced similar but less pronounced changes, and DES (0.1 microg) had no noticeable effect. Tamoxifen and flutamide induced PR and slightly upregulated ERalpha immunoexpression but had only a minor or no effect on AR expression and the stromal:epithelial ratio, though flutamide retarded normal development of the SVs. The latter was also evident in GnRHa-treated males, but otherwise this treatment had no effect on AR and PR immunoexpression. None of the foregoing treatments had any detectable effect on the immunoexpression of ERss in stromal or epithelial cells. The major treatment-induced changes in immunoexpression of AR, PR, and ERalpha and lack of change in ERss were confirmed by Western blots of SV protein extracts. None of the three weak (environmental) estrogens tested caused any detectable change in sex steroid receptor immunoexpression or SV tissue composition. We conclude that treatment-induced loss of AR is a prerequisite for altered stromal:epithelial proportions in the SVs and that such loss is always associated with induction of PR and upregulation of ERalpha; the latter two changes are insufficient on their own to bring about such a change. Nevertheless, induction of PR expression was always associated with altered SV development and is a potentially useful marker because it is not normally expressed in male reproductive tissues.


Assuntos
Poluentes Ambientais/efeitos adversos , Estrogênios/farmacologia , Regulação da Expressão Gênica , Receptores de Esteroides/biossíntese , Glândulas Seminais/ultraestrutura , Animais , Animais Recém-Nascidos , Biomarcadores/análise , Masculino , Ratos , Ratos Wistar , Glândulas Seminais/efeitos dos fármacos , Regulação para Cima
20.
Mol Cell Endocrinol ; 164(1-2): 117-31, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11026564

RESUMO

Oestrogen exposure of the male during fetal/neonatal life can fundamentally alter the structure and function of the reproductive system, though how is unknown. This study examined whether such treatment was able to induce a 'female' characteristic, namely immunoexpression of progesterone receptor (PR), in the reproductive system of the male. Rats were treated on postnatal days 2, 4, 6, 8, 10 and 12 with either 10, 1 or 0.1 microg diethystilbestrol (DES) or with the vehicle (20 microl corn oil). Groups of control and treated rats were killed on days 18, 25, 35 and 90 (= adults) and tissues fixed in Bouins for immunolocalisation studies using antisera to PR (recognises A and B forms) and oestrogen receptor-beta (ER beta). PR immunoexpression was absent from all tissues studied in control rats at all ages with the exception of the parasympathetic ganglia of the prostate. In rats treated with 10 microg DES, intense immunoexpression of PR was detected in the nuclei of stromal, but not epithelial, cells of the caput and cauda epididymis, the vas deferens, seminal vesicles and at the base of the dorsolateral prostatic complex (DLPC) at day 18, but was absent from the ventral prostate and from the testis. DES induction of PR immunoexpression was evident after a single injection (on day 3) and at 18-35 days the intensity of immunoexpression was DES dose-dependent; rats treated neonatally with 0.1 microg DES showed no detectable PR immunoexpression at any age. These findings were confirmed by Western analysis which indicated that most of the PR induced was probably the B form. Co-localisation studies, using confocal microscopy, demonstrated that PR and ER beta frequently co-localised to the same stromal cells in the DLPC, epididymis and seminal vesicles of DES-treated rats at day 18, whereas epithelial cells, which also expressed ER beta, did not express PR. In the tissues studied, only occasional stromal cells expressed ER alpha in comparison to the more widespread expression of ER beta, although epithelial cell expression of ER alpha was also detected in the epididymis on day 18 (but not on day 10). In DES-treated rats, immunoexpression of PR in the reproductive tract decreased progressively in intensity from days 18-35 and was non-detectable in adulthood. In conclusion, these findings are interpreted as evidence that neonatal oestrogen treatment exerts pervasive 'reprogramming' effects throughout the reproductive system of the developing male as indicated by the induction of PR immunoexpression. This induction was restricted to stromal tissue even though both stromal and epithelial cells at most sites expressed ER beta and/or ER alpha.


Assuntos
Dietilestilbestrol/administração & dosagem , Estrogênios não Esteroides/administração & dosagem , Genitália Masculina/fisiologia , Receptores de Progesterona/biossíntese , Envelhecimento/fisiologia , Animais , Imuno-Histoquímica , Masculino , Ratos , Células Estromais/fisiologia
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