Terapia hormonal para criptorquidia com hormônio gonadotrofina coriônica humana (HCG): ensaio clínico randomizado duplo-cego placebo controlado

Objetivo: O objetivo deste estudo foi comparar o efeito do tratamento hormonal do hormônio Gonadotrofina Coriônica Humana (HCG), em dois esquemas posológicos diferentes, ao placebo quanto sua efetividade e segurança no tratamento da Criptorquidia. Métodos: Este estudo é um ensaio clínico randomizado, duplo-cego, placebo-controlado de 14 semanas. A amostra de 92 pacientes que foram randomizados para o grupo-HCG dias alternados, denominados de Grupo G1 (N = 29), para o grupo HCG a cada quatro dias, denominados Grupo G4 (N= 33) e o grupo-placebo, denominados como Grupo O(N = 30). 2. Os desfechos clínicos primários para este estudo foram 1) Cura, 2) Melhora, 3) Não Cura. Os desfechos complementares foram: 4) Efeitos adversos, 5) Níveis séricos hormonais. Resultados: Não existiram diferenças entre os grupos HCG dias alternados, HCG a cada quatro dias e placebo para as medidas dos desfechos primários. 1) Cura: G1: 3/29(3,3%), G4: 4/33(4,3%) e O: 3/30(3,3%) 2) Melhora: G1:3/29(3,3%), G4: 1/33(1,1%) e O: 3/30(3,3%). 3) Não Cura: G1: 23/29(25%), G4: 28/33(30,4%) e O: 24/30(26,1%) p=0,815. 4) Os efeitos adversos mais freqüentes em nossa amostra foram: Aumento do numero de ereções: não foi possível avaliar. 5) Níveis séricos hormonais: Testosterona sérica: G1: de 34,15 ± 5,8ng/ml; G4: 49,6± 5,6 ng/ml e O: 7,5± 3,5ng/ml. Hormônio Luteinizante (LH): G1: 0,22± 0,2 , G4: 0,07±0,1 e O: 0,08±0,02 Hormônio Folículo Estimulante (FSH): G1: 0,88±0,16, G4: 0,3±0,1 e O 1,15±0,6. Conclusão: Não foi encontrada nenhuma diferença estatística no tratamento com HCG, independente da posologia adotada, e placebo. Os autores concluem a hormonioterapia com HCG não demonstrou superioridade na eficácia e ou segurança no tratamento da criptorquidia ao placebo.

[Diagnosis and therapy of hyperthyreosis]

Hyperthyreosis, diabetes and calcium disorders are frequent endocrine diseases that are often encountered by the primary care physician. The diagnosis of hyperthyreosis can be established by many different laboratory and analytical tests. However, the clinical context can often guide a specific diagnostic approach. Graves disease and toxic adenomas are the most frequent causes of hyperthyreosis. Diagnosis of Graves disease is most frequent between age 35 and 60 and about 10-20% of patients show already initially signs of endocrine orbithopathy. Measurement of thyroid stimulating immunoglobulins (TSI) is especially valuable in unclear cases. Toxic adenomas are always diagnosed by thyroid uptake studies. Rare causes of hyperthyreosis include thyreoiditis, which is characterized by transient hyperthyreosis (<2 months), and thyrotoxicosis factitia. Here, we discuss diagnosis and therapy of different causes of hyperthyreosis based on three clinical examples.

In vitro maturation: a five-year experience

Although some patients may benefit from reduced follicle-stimulating hormone (FSH) application, in-vitro maturation (IVM) belongs to the rare treatment options in assisted reproduction. We summarize our five-year IVM experience.

Congenital hypothyroidism in a kitten resulting in decreased IGF-I concentration and abnormal liver function tests

A 7-month-old male kitten was presented with chronic constipation and retarded growth. Clinical examination revealed disproportional dwarfism with mild skeletal abnormalities and a palpable thyroid gland. The presumptive diagnosis of congenital hypothyroidism was confirmed by low serum total thyroxine (tT(4)) concentration prior to and after the administration of thyroid stimulation hormone (TSH), increased endogenous TSH concentration and abnormal thyroid scintigraphic scan. The kitten had abnormal liver function tests and decreased insulin-like growth factor 1 (IGF-1) concentration, both of which returned to normal in correspondence with an improvement of the clinical signs after 6 weeks of thyroxine therapy. Congenital hypothyroidism is a rare disease that may present with considerable variation in clinical manifestation. In cases in which clinical signs are ambiguous, disorders such as portosystemic shunt and hyposomatotropism have to be taken into account as differential diagnosis. As hypothyroidism may be associated with abnormal liver function tests and low IGF-1 concentrations, test results have to be interpreted carefully.

Serum leptin and C-reactive protein levels in the physiological spontaneous menstrual cycle in reproductive age women

OBJECTIVE: Only a few studies have investigated variations of different markers for inflammatory processes during the physiological menstrual cycle. The results are conflicting, particularly concerning the correlation between the marker leptin and steroid hormones. The aim of the study was to investigate the inflammatory markers C-reactive protein (CRP) and leptin in the serum of healthy, normally ovulating women and to correlate these with each other and with the hormones of the gonadal axis. A cycle-dependence of the markers studied would imply an exact timing of the blood sampling for clinical needs. DESIGN: Observational study investigating the two inflammatory markers CRP and leptin in relation to the hormonal pattern of the gonadal axis during the normal cycle. METHODS: Ovulatory cycles of 36 healthy, young, normo-androgenic women, having a normal body mass index were evaluated. Serum concentrations of leptin and CRP, as well as of follicle-stimulating hormone, luteinising hormone, 17beta-oestradiol, progesterone, prolactin (PRL) and free testosterone were measured every 1-2 days during one full cycle. RESULTS: Serum levels of leptin and CRP behaved differently during ovulatory cycles, with higher concentrations for leptin only during certain phases. Significant correlations were found in the follicular phase between leptin and PRL and leptin and free testosterone. CONCLUSIONS: Leptin levels change during the menstrual cycle. Leptin levels are more stable on cycle days 1-5 than later in the cycle. For precise cycle-independent measurements, these fluctuations have to be taken into account. There is no similar cyclic pattern for CRP.

Insulin-like growth factor type-1 receptor down-regulation associated with dwarfism in Holstein calves

Perturbations in endocrine functions can impact normal growth. Endocrine traits were studied in three dwarf calves exhibiting retarded but proportionate growth and four phenotypically normal half-siblings, sired by the same bull, and four unrelated control calves. Plasma 3,5,3'-triiodothyronine and thyroxine concentrations in dwarfs and half-siblings were in the physiological range and responded normally to injected thyroid-releasing hormone. Plasma glucagon concentrations were different (dwarfs, controls>half-siblings; P<0.05). Plasma growth hormone (GH), insulin-like growth factor-1 (IGF-1) and insulin concentrations in the three groups during an 8-h period were similar, but integrated GH concentrations (areas under concentration curves) were different (dwarfs>controls, P<0.02; half-siblings>controls, P=0.08). Responses of GH to xylazine and to a GH-releasing-factor analogue were similar in dwarfs and half-siblings. Relative gene expression of IGF-1, IGF-2, GH receptor (GHR), insulin receptor, IGF-1 type-1 and -2 receptors (IGF-1R, IGF-2R), and IGF binding proteins were measured in liver and anconeus muscle. GHR mRNA levels were different in liver (dwarfs

Androgen and gonadotropin patterns differ in HIV-1-infected men who develop lipoatrophy during antiretroviral therapy: a case-control study

OBJECTIVES: We compared androgen and gonadotropin values in HIV-infected men who did and did not develop lipoatrophy on combination antiretroviral therapy (cART). METHODS: From a population of 136 treatment-naïve male Caucasians under successful zidovudine/lamivudine-based cART, the 10 patients developing lipoatrophy (cases) were compared with 87 randomly chosen controls. Plasma levels of free testosterone (fT), dehydroepiandrosterone (DHEA), follicle-stimulating hormone and luteinizing hormone (LH) were measured at baseline and after 2 years of cART. RESULTS: At baseline, 60% of the cases and 71% of the controls showed abnormally low fT values. LH levels were normal or low in 67 and 94% of the patients, respectively, indicating a disturbance of the hypothalamic-pituitary-gonadal axis. fT levels did not significantly change after 2 years of cART. Cases showed a significant increase in LH levels, while controls showed a significant increase in DHEA levels. In a multivariate logistic regression model, lipoatrophy was associated with higher baseline DHEA levels (P=0.04), an increase in LH levels during cART (P=0.001), a lower body mass index and greater age. CONCLUSIONS: Hypogonadism is present in the majority of HIV-infected patients. The development of cART-related lipoatrophy is associated with an increase in LH and a lack of increase in DHEA levels.

Prevalence of Premature Ovarian Failure in Women with Tuberous Sclerosis

Tuberous Sclerosis Complex (TSC) is an autosomal dominant tumor suppressor disorder characterized by hamartomas, or benign growths, in various organ systems. Inactivating mutations in either the TSC1 or the TSC2 gene cause most cases of TSC. Recently, the use of ovarian specific conditional knock-out mouse models has demonstrated a crucial role of the TSC genes in ovarian function. Mice with complete deletion of Tsc1 or Tsc2 showed accelerated ovarian follicle activation and subsequent premature follicular depletion, consistent with the human condition premature ovarian failure (POF). POF is defined in women as the cessation of menses before the age of 40 and elevated levels of follicle stimulating hormone (FSH). The prevalence of POF is estimated to be 1%, affecting a substantial number of women in the general population. Nonetheless, the etiology of most cases of POF remains unknown. Based on the mouse model results, we hypothesized that the human TSC1 and TSC2 genes are likely to be crucial for ovarian development and function. Moreover, since women with TSC already have one inactivated TSC gene, we further hypothesized that they may show a higher prevalence of POF. To test this hypothesis, we surveyed 1000 women with TSC belonging to the Tuberous Sclerosis Alliance, a national support organization. 182 questionnaires were analyzed for information on menstrual and reproductive function, as well as TSC. This self-reported data revealed 8 women (4.4%) with possible POF, as determined by menstrual history report and additional supportive data. This prevalence is much higher than 1% in the general population. Data from all women suggested other reproductive pathology associated with TSC such as a high rate of miscarriage (41.2%) and menstrual irregularity of any kind (31.2%). These results establish a previously unappreciated effect of TSC on women’s reproductive health. Moreover, these data suggest that perturbations in the cellular pathways regulated by the TSC genes may play an important role in reproductive function.

Mechanical constraints imposed by 3D cellular geometry and arrangement modulate growth patterns in the Arabidopsis embryo

Morphogenesis occurs in 3D space over time and is guided by coordinated gene expression programs. Here we use postembryonic development in Arabidopsis plants to investigate the genetic control of growth. We demonstrate that gene expression driving the production of the growth-stimulating hormone gibberellic acid and downstream growth factors is first induced within the radicle tip of the embryo. The center of cell expansion is, however, spatially displaced from the center of gene expression. Because the rapidly growing cells have very different geometry from that of those at the tip, we hypothesized that mechanical factors may contribute to this growth displacement. To this end we developed 3D finite-element method models of growing custom-designed digital embryos at cellular resolution. We used this framework to conceptualize how cell size, shape, and topology influence tissue growth and to explore the interplay of geometrical and genetic inputs into growth distribution. Our simulations showed that mechanical constraints are sufficient to explain the disconnect between the experimentally observed spatiotemporal patterns of gene expression and early postembryonic growth. The center of cell expansion is the position where genetic and mechanical facilitators of growth converge. We have thus uncovered a mechanism whereby 3D cellular geometry helps direct where genetically specified growth takes place.

AN INVESTIGATION INTO THE EFFECT OF TESTOSTERONE ON THE QUANTITATIVE MAINTENANCE OF SPERMATOGENESIS IN THE HYPOPHYSECTOMIZED ADULT RAT (PHARMACOKINETICS, MORPHOMETRY, STATISTICS)

Administration of gonadotropins or testosterone (T) will maintain qualitatively normal spermatogenesis and fertility in hypophysectomized (APX) rats. However, quantitative maintenance of the spermatogenic process in APX rats treated with T alone or in combination with follicle stimulating hormone (FSH) has not been demonstrated. Studies reported here were conducted to determine whether it would be possible to increase intratesticular testosterone (ITT) levels in APX rats to those found in normal animals by administration of appropriate amounts of testosterone propionate (TP) and if under these conditions spermatogenesis can be maintained quantitatively. Quantitative analysis of spermatogenesis was performed on stages VI and VII of the spermatogenic cycle utilizing criteria of Leblond and Clermont (1952) all cell types were enumerated. In a series of experiments designed to investigate the effects of T on spermatogenesis, TP was administered to 60 day old APX rats twice daily for 30 days in doses ranging from 0.6 to 15 mg/day or from 0.6 to 6.0 mg/day in combination with FSH. The results of this study demonstrate that the efficiency of transformation of type A to type B spermatogonia and the efficacy of the meiotic prophase are related to ITT levels, and that quantitatively normal completion of the reduction division requires normal ITT levels. The ratio of spermatids to spermatocytes in the vehicle-treated APX rats was 1:1.38; in the APX rats treated with 15 mg of TP it was 1:4.0 (the theoretically expected number). This study is probably the first to demonstrate: (1) the pharmacokinetics of TP, (2) the profile and quantity of T-immunoactivity in both serum and testicular tissue of APX and IC rats as well as APX rats treated with TP alone or in combination with FSH, (3) the direct correlation of serum T and ITT levels in treated APX rats (r = 0.9, p < 0.001) as well as in the IC rats (r = 0.9, p < 0.001), (4) the significant increase in the number of Type B spermatogonia, preleptotene and pachytene spermatocytes and round spermatids in TP-treated APX rats, (5) the correlation of the number of round spermatids formed in IC rats to ITT levels (r = 0.9, p < 0.001), and (6) the correlation of the quantitative maintenance of spermatogenesis with ITT levels (r = 0.7, p < 0.001) in the testes of TP-treated APX rats. These results provide direct experimental evidence for the key role of T in the spermatogenic process. ^

Phthalate exposure among US women, NHANES 1999--2002: Relationship to serum gonadotropin levels

Phthalates are industrial chemicals used primarily as plasticizers though they and are found in a myriad of consumer goods such as children's toys, food packaging, dental sealants, cosmetics, pharmaceuticals, perfumes, and building materials. US biomonitoring data show more than 75% of the population have exposure to mono-n-butyl phthalate (MBP), mono-ethyl phthalate (MEP), mono-(2-ethyl) hexyl phthalate (MEHP), and mono-benzyl phthalate (MBZP). Reproductive toxicity from phthalate exposure in animal models has raised concerns about similar effects on fertility in humans. This dissertation research focuses on phthalate exposures in the US population and investigates the plausibility of an exposure-response relationship between phthalates and endocrine hormones essential for ovulation among US women. The objective of this research is to determine the relationship between levels of gonadotropins, follicle stimulating hormone (FSH) and leutinizing hormone (LH), and urinary phthalate monoester metabolites: MBP, MEP, MEHP, MBZP among National Health and Nutrition Examination Survey (NHANES) 1999-2002 women aged 35 to 60 years. Using biomarker data from a one-third sub-sample of NHANES participants, log transformed serum FSH and serum LH, respectively were regressed on phthalates controlling for age, body mass index, smoking, and creatinine taking into consideration the complex survey design (n=385). Models were stratified by reproductive status: reproductive (n=185), menopause transition (n=49) and post-menopausal (n=125). A decrease in FSH associated with increasing MBzP (beta=-0.094, p<0.05) was observed for all participants but no statistical association between log FSH and MBP, MEP, or MEHP was seen. A decrease in LH (beta=-0.125, p<0.05) was also observed with increasing MBzP for all participants though there was no relationship between levels of LH and MBP, MEP, or MEHP. The observed associations between FSH, LH and MBzP did not persist when stratified by reproductive status. Thus, the present study shows a change in endocrine hormones related to ovulation with increasing urinary MBzP among a representative sample of US women from 1999-2002 though this observed exposure-response relationship does not remain after stratification by reproductive status. ^

Characterization of genes modulated during pheomelanogenesis using differential display

Molecular and biochemical mechanisms that modulate the production of eumelanin or pheomelanin pigments involve the opposing effects of two intercellular signaling molecules, α-melanocyte stimulating hormone (MSH) and agouti signal protein (ASP). ASP is an antagonist of MSH signaling through the melanocyte-specific MSH receptor, although its mechanism(s) of action is controversial. We previously have reported significant down-regulation of all known melanogenic genes during the eumelanin to pheomelanin switch in murine hair follicle melanocytes and in cultured melanocytes treated with recombinant ASP. To identify factors that might be involved in the switch to pheomelanogenesis, we screened ASP-treated melanocytes by using differential display and identified three up-regulated genes: a DNA replication control protein, a basic helix–loop–helix transcription factor, and a novel gene. We have simultaneously identified six down-regulated genes in ASP-treated melanocytes; two of those encode tyrosinase and TRP2, melanogenic genes known to be down-regulated during pheomelanogenesis, which provide good internal controls for this approach. These results suggest that there are complex mechanisms involved in the switch to pheomelanin production, and that these modulated genes might be involved in the pleiotropic changes seen in yellow mice, including the change in coat color.

Characterization of mice deficient in aromatase (ArKO) because of targeted disruption of the cyp19 gene

The formation of estrogens from C19 steroids is catalyzed by aromatase cytochrome P450 (P450arom), the product of the cyp19 gene. The actions of estrogen include dimorphic anatomical, functional, and behavioral effects on the development of both males and females, considerations that prompted us to examine the consequences of deficiency of aromatase activity in mice. Mice lacking a functional aromatase enzyme (ArKO) were generated by targeted disruption of the cyp19 gene. Male and female ArKO mice were born with the expected Mendelian frequency from F1 parents and grew to adulthood. Female ArKO mice at 9 weeks of age displayed underdeveloped external genitalia and uteri. Ovaries contained numerous follicles with abundant granulosa cells and evidence of antrum formation that appeared arrested before ovulation. No corpora lutea were present. Additionally the stroma were hyperplastic with structures that appeared to be atretic follicles. Development of the mammary glands approximated that of a prepubertal female. Examination of male ArKO mice of the same age revealed essentially normal internal anatomy but with enlargement of the male accessory sex glands because of increased content of secreted material. The testes appeared normal. Male ArKO mice are capable of breeding and produce litters of approximately average size. Whereas serum estradiol levels were at the limit of detection, testosterone levels were elevated, as were the levels of follicle-stimulating hormone and luteinizing hormone. The phenotype of these animals differs markedly from that of the previously reported ERKO mice, in which the estrogen receptor α is deleted by targeted disruption.

Adenosine acts by A1 receptors to stimulate release of prolactin from anterior-pituitaries in vitro

Adenosine has been identified in the anterior pituitary gland and is secreted from cultured folliculostellate (FS) cells. To determine whether adenosine controls the secretion of anterior pituitary hormones in vitro, adenosine was incubated with anterior pituitaries. It stimulated prolactin (PRL) release at the lowest concentration used (10−10 M); the stimulation peaked at 10−8 M with a threefold increase in release and declined to minimal stimulation at 10−4 and 10−3 M. Follicle-stimulating hormone release was maximally inhibited at 10−8 M, whereas luteinizing hormone release was not significantly inhibited. Two selective A1 adenosine receptor antagonists (10−7 or 10−5 M) had no effect on basal PRL release, but either antagonist completely blocked the response to the most effective concentration of adenosine (10−8 M). In contrast, a highly specific A2 receptor antagonist (10−7 or 10−5 M) had no effect on basal PRL release or the stimulation of PRL release induced by adenosine (10−8 M). We conclude that adenosine acts to stimulate PRL release in vitro by activating A1 receptors. Since the A1 receptors decrease intracellular-free calcium, this would decrease the activation of nitric oxide synthase in the FS cells, resulting in decreased release of nitric oxide (NO). NO inhibits PRL release by activating guanylate cyclase that synthesizes cGMP from GTP; cGMP concentrations increase in the lactotrophs leading to inhibition of PRL release. In the case of adenosine, NO release from the FS cells decreases, resulting in decreased concentrations of NO in the lactotrophs, consequent decreased cGMP formation, and resultant increased PRL release.

Mahogany (mg) stimulates feeding and increases basal metabolic rate independent of its suppression of agouti

The mahogany (mg) locus originally was identified as a recessive suppressor of agouti, a locus encoding a skin peptide that modifies coat color by antagonizing the melanocyte-stimulating hormone receptor or MC1-R. Certain dominant alleles of agouti cause an obesity syndrome when ectopic expression of the peptide aberrantly antagonizes the MC4-R, a related melanocyte-stimulating hormone receptor expressed in hypothalamic circuitry and involved in the regulation of feeding behavior and metabolism. Recent work has demonstrated that mg, when homozygous, blocks not only the ability of agouti to induce a yellow coat color when expressed in the skin of the lethal yellow mouse (AY), but also the obesity resulting from ectopic expression of agouti in the brain. Detailed analysis of mg/mg AY/a animals, presented here, demonstrates that mg/mg blocks the obesity, hyperinsulinemia, and increased linear growth induced by ectopic expression of the agouti peptide. Remarkably, however, mg/mg did not reduce hyperphagia in the AY/a mouse. Furthermore, mg/mg induced hyperphagia and an increase in basal metabolic rate in the C57BL/6J mouse in the absence of AY. Consequently, although mahogany is broadly required for agouti peptide action, it also appears to be involved in the control of metabolic rate and feeding behavior independent of its suppression of agouti.