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PubMed1996

The regulation of follicle growth: some clinical implications in reproductive endocrinology.

OBJECTIVE: To review the literature concerning the regulation of follicle growth, to describe a model for unifollicular ovulation based upon the information gleaned, and to discuss some clinical implications in reproductive endocrinology underscored by this expanding knowledge. DESIGN: Studies relating to follicular growth in lower animals and primates were reviewed. From the most pertinent articles the individual agents playing a significant role in the regulation of follicle growth were identified along with their mechanisms of action. A model for unifollicular development was proposed based upon the results of the review of these studies. Refinements in the management of some clinical problems in reproductive endocrinology were discussed based upon this model. RESULTS: From a review of these studies it appears that in the human and primate menstrual cycle one follicle is selected because it has adequate FSH receptors when plasma FSH levels are high. This follicle becomes dominant despite falling FSH levels because of increased sensitivity of the follicle to FSH brought about by intraovarian growth regulators. CONCLUSIONS: Improved care of patients requiring ovulation induction for differing indications should be possible with this more comprehensive knowledge of natural follicle growth.

Amenorrhea↗
PubMed1987

A cytogenetic and endocrinologic study of a set of monozygotic isokaryotic 45,X/46,XY twins discordant for phenotypic sex: mosaicism versus chimerism.

Newborn monozygotic twins with phenotypic sexual discordance were diagnosed with 45,X/46,XY gonadal dysgenesis. Cytogenetic studies of peripheral blood (serial), skin, and gonad were performed. Serial comparative gonadotropin data and luteinizing hormone-releasing hormone stimulation tests were obtained. A phenotypically normal male twin was found to have a significant number of 45,X cells only in lymphocytes and was considered endocrinologically intact. The sexually ambiguous twin sister demonstrated a significant number of 45,X cell lines in all tissues and was considered endocrinologically agonadal. These data demonstrate the role of the 45,X karyotype on abnormal gonadal formation and function and make possible different etiologies for the 45,X cell line in both twins. While mosaicism is likely for both, chimerism is possible for the normal male.

Adolescent↗
PubMed2003

Effects of different forms of environmental enrichment on behavioral, endocrinological, and immunological parameters in male mice.

This study investigated effects of different forms of environmental enrichment on behavioral, endocrinological, and immunological parameters in male mice. For this purpose, animals of the inbred strain CS were kept in groups of four males under three different housing conditions: (A) nonstructured Makrolon type III laboratory cages ("standard-housing" = S); (B) equivalent laboratory cages that were enriched with a box and a scaffolding ("enriched-housing" = E); and (C) spacious terraria that were structured richly ("super-enriched-housing" = SE). Both forms of enrichment caused a sharp rise in aggressive behavior, though play behavior was increased in E and SE mice, too. Levels of sociopositive behaviors in S and SE mice were higher than those in E mice. Plasma corticosterone concentrations and adrenal tyrosine hydroxylase activities were significantly increased in male mice kept in both forms of enriched cages, indicating an activation of the pituitary-adrenocortical and the adrenomedullary systems. The behavioral and endocrinological differences were partly reflected by immunological parameters: SE mice had levels of IgG1 and ratios of IFN-gamma/IL-10 and IL-2/IL-10 significantly lower than those of S mice. Ratios of IgG2a/IgG1 were significantly higher in SE mice. The absolute percentages of CD8 cells in E-mice were significantly lower than those in S mice. Despite the elevated levels of stress hormones under both forms of enriched housing, the behavioral parameters also indicate positive effects of the enrichment, especially on SE animals. Obviously, an environmental enrichment is beneficial for male mice as long as the spatial conditions are generous enough to allow coping with the increased aggression brought about by the enrichment.

Aggression↗
PubMed2002

Application of comparative genomics in fish endocrinology.

This review discusses the ways in which comparative genomics can contribute to the study of fish endocrinology. First, the phylogenetic position of fish and an overview of their specific endocrine systems are presented. The emphasis will be on teleosts because they are the most abundant fishes and because most data are available for this group. Second, the complexity of fish genomics is reviewed. With the vast array of genome sizes and ploidy levels, assignment of gene orthology is more difficult in fish, but this is an absolute prerequisite in functional analysis and it is important to be aware of such genome plasticity when cloning genes. The ease with which a gene is cloned at the genomic level is directly related to genome size and complexity, a factor that is not known in the majority of fish species. Finally, the methodology is presented along with specific examples of parathyroid hormone-related protein (PTHrP) (a previously unidentified hormone in fish), calcium-sensing receptor, and calcitonin (with a duplication of this particular ligand in Fugu rubripes). Preliminary data also suggest that there are further duplicated genes in the calcium regulatory system. Comparative genomics has provided a valuable approach for isolating and characterizing a range of fish genes involved in calcium regulation. However, for understanding the physiology and endocrine regulation of this system, particularly with regard to gene duplication, an alternative approach is required in which conventional endocrinology techniques will play a significant role.

Animals↗
PubMed2001

[Referral to endocrinology because of thyroid pathology. Quality and justification].

OBJECTIVES: To describe the content of the form for referring patients to endocrinology because of thyroid pathology, to compare this form with the specialist report and to analyse the justification for the referral and its association with its origin. DESIGN: Descriptive. SETTING: Primary/specialist care. PARTICIPANTS: All the patients (412) referred to 4 endocrinology clinics for undefined thyroid pathology. RESULTS: 81% of the 273 cases without history on the form had this history in the report. The symptoms were recorded more often in the report than on the form except for local compression (23 cases, of which the endocrinologist confirmed 5). 59.3% of the forms included the analysis results, and 31% the physical examination of the thyroid. Consistency, size and nodularity of the goitre were only indicated in a minority of forms. Diagnostic concordance was low (kappa = 31%). 15.2% were cases of simple goitre. Cases whose referral according to an established protocol was justified amounted to 51% when the reason was taken into account, and 39% when the diagnosis was taken into account. These figures bore no relation to the zone or centre originating the referral. Most patients, including those whose referral was not necessary, had further tests (PAAF, echography, gammagraphy). CONCLUSIONS: Compliance with the form is insufficient, although it is difficult to decide if this implies incorrect handling of the patient. Physical examination of the thyroid needs to be improved. The referral of many patients is not justifiable, although the pathology that predominates is one that may pose diagnostic difficulties without the specific examinations that are in fact requested in the specialist clinics.

Family Practice↗
PubMed2002

Inhibition of aromatase activity by green tea extract catechins and their endocrinological effects of oral administration in rats.

We orally administered polyphenone-60 (P-60), green tea extract catechins, in the diet (0, 1.25 and 5%) to male rats for 2, 4 and 8 weeks initiated at 5 weeks old. It was found that a 5% dose to male rats for 2-8 weeks induced goiters and decreased weights of the body, testis and prostate gland. Endocrinologically, elevating plasma thyroid stimulating hormone (TSH), luteinizing hormone (LH) and testosterone levels and decreasing tri-iodothyronine (T(3)) and thyroxine (T(4)) levels were induced by this treatment. We also found that P-60 as a whole and some of its constituents exhibited inhibitory effects on human placental aromatase activity by in vitro assay. The concentration of P-60 that required producing 50% inhibition of the aromatase activity (IC(50) value) was 28 microg/ml. The IC(50) values of (-)-catechin gallate (Cg), (-)-epigallocatechin (EGC), (-)-epigallocatechin gallate (EGCg) and (-)-gallocatechin gallate (GCg) were 5.5 x 10(-6), 1.0 x 10(-4), 6.0 x 10(-5) and 1.5 x 10(-5) M, respectively. (-)- Epicatechin gallate (ECg) at 1.0 x 10(-4) M produced 20% inhibition. (-)-Epicatechin (EC) and (+)-catechin (CT) exhibited no effects on aromatase activity. The endocrinological changes observed in vivo were in conformity with antithyroid effects and aromatase inhibition effects of P-60 and its constituents.

Administration, Oral↗
PubMed2000

Sex-role reversal in vertebrates: behavioural and endocrinological accounts.

Sex-role reversal occurs when females compete more intensely than males for access to mates. In this paper, we survey the occurrence of sex-role reversal in vertebrates: we focus on behavioural aspects of sex-role reversal and we examine possible endocrinological correlates of this phenomenon. The best documented cases among vertebrates of sex-role reversal occur in fish and birds. In nearly all sex-role reversed species or populations, females have higher potential reproductive rates than males. Some species in which females were previously thought to be the predominant competitors for mates (for instance seahorses and a dendrobatid frog), appear not to be sex-role reversed according to recent studies. The endocrinology of sex-role reversal has been studied in only a few species and therefore remains poorly understood. In birds, which probably have been studied the most in this respect, steroid hormones appear to follow the typical ancestral conditions (for instance no reversal of testosterone levels) in sex-role reversed species, whereas prolactin, a principal regulator of the onset and maintenance of incubation, departs from the usual avian pattern in that it is higher in males than in females. The study of sex-role reversed behaviour offers unique opportunities not only to test sexual selection theory, but also to enhance our understanding of the neuroendocrine mechanisms mediating behavioural sex differences.

Journal Article↗
PubMed1988

Mandibular atrophy and metabolic bone loss. Endocrinology, radiology and histomorphometry.

In 11 edentulous patients with a severe atrophy of the mandible and submitted for ridge augmentation, endocrinological, radiological and histomorphometrical studies were carried out. The results showed that metabolic bone loss, histologically in nearly all patients characterized as a disturbance in mineralization and endocrinologically in 55-73% of the patients as a secondary hyperfunction of the parathyroid glands, plays a rôle in the etiology of mandibular atrophy.

Atrophy↗
PubMed2001

Elemental anomalies in hair as indicators of endocrinologic pathologies and deficiencies in calcium and bone metabolism.

Analytical results obtained by ICP-MS of hair samples from a group of women from Rio de Janeiro city show that abnormal Ca and P concentrations in this compartment can be an indication of pathologies affecting the metabolism of these elements. The study was conducted initially on 900 women (outpatients, >40 years). From this group, approx. 24% showed anomalously high or low Ca concentrations in hair, in some cases correlated to anomalies of other elements. In 144 cases (16%), very high concentrations of Ca (up to 8,285 mg/kg) were measured, frequently correlated with a high concentration of P (up to 4,720 mg/kg), exceeding by far the reference intervals for this age/sex group. Follow-up studies of a few individuals from this group gave first indications that their abnormal hair compositions were related to endocrinologic pathologies affecting calcium/bone metabolism. Very low hair Ca-concentrations were observed in older women (72 cases, age >60 years) and related to senile osteoporosis. Complementary investigations of patients with recognized endocrinologic pathologies (hyperthyroidism, hyper- and hypoparathyroidism) and osteomalacia gave statistical support for the hypothesis that hair concentrations of Ca, P and various other trace elements are influenced characteristically by these diseases. In patients with hyperparathyroidism and hyperthyroidism, both elements showed significant increase in hair, whereas patients with rickets/osteomalacia had only elevated Ca concentrations, together with suspiciously high toxic levels of Cd and various other elements (Fe, Mn, Mg, Sr, Ba). Patients with hypoparathyroidism had significantly decreased Ca and P concentrations in hair. Statistical evaluation of these data by multivariant analysis (MANOVA) using a contrast matrix and by discriminant analysis showed that elemental hair anomalies can be used to diagnose correctly the above-mentioned pathologies, demonstrating the usefulness of hair analysis as a complementary tool for the detection of disturbances in calcium/bone metabolism.

Adult↗
PubMed2003

Endocrinological activities of ghrelin: new insights.

Ghrelin is a potent endogenous growth hormone secretagogue in supraphysiological doses. It also exhibits several other endocrinological (e.g. lactotrophic and corticotrophic) activities when given intravenously. However, the significance of these effects in a normal physiological situation is still unknown, and subcutaneous administration of ghrelin seems to only increase growth hormone secretion. Interest in ghrelin research is currently focused on energy metabolism; the link between ghrelin and the regulation of both growth and energy metabolism is missing. In this paper we present an up-to-date review of the endocrinological activities of ghrelin.

Journal Article↗
PubMed1975

[Endocrinological and histomorphological studies of testicular atrophy in myotonic dystrophy (author's transl)].

Testicular atrophy in myotonic dystrophy is caused by a primary and progressive atrophy of the seminiferous tubules. Endocrinological studies with synthetic LH(ICSH)-RH in two patients demonstrated the complete absence of FSH feed back mechanism. Glycogen content was markedly diminished or completely absent, as demonstrated histochemically, both in the morphologically intact and in damaged tubules. The endocrinological and morphological results both demonstrate that insufficiency of the Sertoli cells is the primary damage in the pathogenesis of testicular atrophy in myotonic dystrophy.

Adrenocorticotropic Hormone↗
PubMed2005

[Biological hypotheses of schizophrenia: possible influences of immunology and endocrinology].

A great number of studies show biological alterations in patients with schizophrenia, but many of these data are conflicting. Schizophrenia is a vastly heterogeneous disorder, most likely not caused by one etiological factor, but rather due to a complex network of different, interacting pathogenic influences. Variable clinical pictures may reflect different etiological factors. In a comprehensive theory of the origin of schizophrenic disorders, genetic and environmental influences cause changes in neuronal development which result in functional alterations of different neurotransmitter systems. Immunological research in schizophrenia was initially based on the "infection hypothesis" which was triggered by observing schizophrenia-like psychoses after influenza pandemic. Numerous immunological studies focusing on antibodies against specific viruses, unspecific antibodies and different other immune-phenomena were carried out in schizophrenia patients. Although the variability of the results from these studies is strikingly high, subgroups of patients with schizophrenia show an activated inflammatory response system with increased levels of proinflammatory cytokines and acute phase proteins. Furthermore, some investigations find changing activities in the T-cell system with a shift of TH-1 to an increased TH-2 activity. Endocrinological factors which may play a relevant role in the etiopathogenesis of schizophrenia include sex hormones and all changes caused by stress or other influences which are directly related to the HPA-axis. Alterations of the immune and the endocrinological systems might be caused by environmental factors like infections or exogenous stress. Due to the intensive interaction between the central nervous system, the immune system and different hormones the "development of a pathology" like schizophrenia can be seen in an integrative but multifactorial fashion. The clinical manifestation, the severity and the course of the disease might then be modulated by genetic vulnerability, the time of the "primary insult" -- which could be an infection, or psychological stress -- and its neuronal localisation and intensity. Different compensatory and decompensatory mechanisms in later life very likely play a crucial role for the further course of the disorder.

Endocrine Glands↗
PubMed2006

Endocrinology of recurrent pregnancy loss.

Following implantation, the maintenance of the pregnancy is dependent on a multitude of endocrinological events that will eventually aid in the successful growth and development of the fetus. Although the great majority of pregnant women have no pre-existing endocrine abnormalities, a small number of women can have certain endocrine alterations that could potentially lead to recurrent pregnancy losses. It is estimated that approximately 8 to 12% of all pregnancy losses are the result of endocrine factors. During the preimplantation period, the uterus undergoes important developmental changes stimulated by estrogen, and more importantly, progesterone. Progesterone is essential for the successful implantation and maintenance of pregnancy. Therefore, disorders related to inadequate progesterone secretion by the corpus luteum are likely to affect the outcome of the pregnancy. Luteal phase deficiency, hyperprolactinemia, and polycystic ovarian syndrome are some examples. Several other endocrinological abnormalities such as thyroid disease, hypoparathyroidism, uncontrolled diabetes, and decreased ovarian reserve have been implicated as etiologic factors for recurrent pregnancy loss.

Abortion, Habitual↗
PubMed1994

[The value of MR tomography after transsphenoidal hypophyseal resection. A retrospective comparison between endocrinology, operation and MRT].

Postoperative magnetic resonance images of 40 patients after transsphenoidal surgery for pituitary adenoma were evaluated retrospectively. The signal intensities of packing material and residual tumour were analysed. T1-weighted spin-echo sequences were obtained in coronal and sagittal views with and without intravenous injection of contrast media. Residual tumour demonstrated homogeneous or inhomogeneous signal intensity on the native scan with homogeneous or inhomogeneous enhancement. Packing material demonstrated a homogeneous signal intensity on the images obtained without injection of contrast media with a peripheral enhancement or alternate layers of low and intermediate signal intensity with alternate enhancement after injection of contrast media. In 5 of 54 examinations different results were found in MRI, endocrinology and surgery (two false negative and one false positive MRI in correlation with endocrinology; two residual tumours on MRI where surgery was supposed to be complete). Application of intravenous contrast media facilitates the interpretation of postoperative examination of the pituitary gland as well as comparison with preoperative examinations and the knowledge of the intraoperative procedure.

Adenoma↗
PubMed1978

Endocrinologically incomplete transethmoidal trans-sphenoidal hypophysectomy with relief of bone pain in breast cancer.

To assess endocrinologic completeness of transethmoidal trans-sphenoidal hypophysectomy and the relation between postoperative pituitary hormone levels and relief of bone pain, we tested pituitary reserve by measuring base-line values of follicle-stimulating hormone and luteinizing hormone, thyrotropin-relasing-factor-stimulated thyrotropin and prolactin, and levodopa-stimulated growth hormone after hypophysectomy in 15 menopausal women with metastatic breast cancer. In all 15 bone pain diminished or disappeared within 24 hours of operation. Pituitary-function testing identified only one patient as having had an endocrinologically complete hypophysectomy. Base-line gonadotropin levels and thyrotropin-releasing-factor-stimulated prolactin were the most reliable measures of residual pituitary function. We conclude that transethmoidal trans-sphenoidal hypophysectomy may not totally ablate pituitary endocrine function; effective relief of bone pain in patients with metastic breast cancer can follow this procedure despite residual pituitary function and the lack of objective tumor remission.

Bone Neoplasms↗
PubMedDate not supplied

Reproductive endocrinology and toxicological pathology over the life span of the female rodent.

Understanding the pathology of the female reproductive system with respect to toxicology requires a basic understanding of morphology and function of the system over time because the nature of the female reproductive system is cyclical. Thus, the morphology and the endocrinology is dependent on age and time, as form follows function and function follows form. The life span of the rodent is used as an outline to present an overview of key morphological and endocrinological events important for toxicologic pathologists to consider in study evaluations. Environmental and pharmaceutical compounds differentially impact the organs individually and/or the system in its entirety in a time- and dose-dependent way. Examples are used to illustrate the consequences of exposures at different times and with different outcomes.

Animals↗
PubMedDate not supplied

Endocrinologic studies in men exposed occupationally to carbon disulfide.

The effect of long-term occupational exposure to CS2 on various endocrinologic parameters was studied in 15 exposed men and 16 age-matched controls. Duration of exposure varied between 10 and 36 yr. The CS2 concentrations in the viscose rayon plant have been below the Finnish threshold limit value of 30 mg/m3 (10 ppm) under normal operating conditions for the past 10 yr. Before this the exposure was considerably greater. Of the various endocrinologic parameters, serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) were significantly increased in the exposed group, seven workers having values above the reference limit. This was taken as a sign of primary gonadal insufficiency, which was considered only latent as serum testosterone values were unaffected. No changes were seen in serum prolactin values before or after stimulation with thyrotropin releasing hormone (TRH). No disturbance was seen in thyroid function as evaluated by serum thyroxine (T4), free thyroxine index (FT1), triiodothyronine (T3), and the thyrotropin response to TRH. Serum cortisol was also unchanged. These results may reflect high exposure during past decades rather than exposure to the present low CS2 concentrations.

Adult↗
PubMed2005

Expression of the reproductive female-specific vitellogenin gene in endocrinologically induced male and intersex Cherax quadricarinatus crayfish.

In oviparous females, the synthesis of the yolk precursor vitellogenin is an important step in ovarian maturation and oocyte development. In decapod Crustacea, including the red-claw crayfish (Cherax quadricarinatus), this reproductive process is regulated by inhibitory neurohormones secreted by the endocrine X-organ-sinus gland (XO-SG) complex. In males, the C. quadricarinatus vitellogenin gene (CqVg), although present, is not expressed under normal conditions. We show here that endocrine manipulation by removal of the XO-SG complex from male animals induced CqVg transcription. The CqVg gene was expressed differentially during the molt cycle in these induced males: no expression was seen in the intermolt stages, but expression was occasionally detected in the premolt stages and always detected in the early postmolt stages. Relative quantitation with a real-time reverse transcriptase-polymerase chain reaction showed that expression of CqVg in induced early postmolt males was an order of magnitude lower than that in reproductive females, a finding that was consistent with RNA in situ hybridization results. The SDS-PAGE of high-density lipoproteins from the hemolymph of endocrinologically induced early postmolt males did not show the typical vitellogenin-related polypeptide profile found in reproductive females. On the other hand, removal of the XO-SG complex from intersex individuals, which are chromosomally female but functionally male and possess an arrested female reproductive system, induced the expression, translation, and release of CqVg products into the hemolymph, as was the case for vitellogenic females. The expression of CqVg in endocrinologically manipulated molting males and intersex animals provides an inducible model for the investigation and understanding of the endocrine regulation of CqVg expression and translation in Crustacea as well as the relationship between the endocrine axes regulating molt and reproduction.

Animals↗