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Endocrine Glands (endocrine + gland)
Selected AbstractsFrontiers in sebaceous gland biology and pathologyEXPERIMENTAL DERMATOLOGY, Issue 6 2008Christos C. Zouboulis Abstract:, The development of experimental models for the in vitro study of human sebaceous gland turned down the theory of a phylogenetic relict and led to the identification of several, unknown or disregarded functions of this organ. Such functions are the production of foetal vernix caseosa, the influence of three-dimensional organization of the skin surface lipids and the integrity of skin barrier and the influence on follicular differentiation. In addition, the sebaceous gland contributes to the transport of fat-soluble antioxidants from and to the skin surface, the natural photoprotection, the pro- and antiinflammatory skin properties and to the innate antimicrobial activity of the skin. It is mainly responsible for skin's independent endocrine function, the hormonally induced skin ageing process, the steroidogenic function of the skin as well as its thermoregulatory and repelling properties and for selective control of the hormonal and xenobiotical actions of the skin. Interestingly, sebocytes, at least in vitro, preserve characteristics of stem-like cells despite their programming for terminal differentiation. This review reports on various sebaceous gland functions, which are currently under investigation, including its role on the hypothalamus,pituitary,adrenal-like axis of the skin, the impact of acetylcholine on sebocyte biology, the activity of ectopeptidases as new targets to regulate sebocyte function, the effects of vitamin D on human sebocytes, the expression of retinoid metabolizing cytochrome P450 enzymes and the possible role of sebum as vehicle of fragrances. These multiple homeostatic functions award the sebaceous gland the role ,brain of the skin' and the most important cutaneous endocrine gland. [source] White Adipose Tissue: Getting NervousJOURNAL OF NEUROENDOCRINOLOGY, Issue 11 2003E. Fliers Abstract Neuroendocrine research has altered the traditional perspective of white adipose tissue (WAT) as a passive store of triglycerides. In addition to fatty acids, WAT produces many hormones and can therefore be designated as a traditional endocrine gland actively participating in the integrative physiology of fuel and energy metabolism, eating behaviour and the regulation of hormone secretion and sensitivity. WAT is controlled by humoral factors, para- and intracrine factors and by neural regulation. Sympathetic nerve fibres innervate WAT and stimulate lipolysis, leading to the release of glycerol and free fatty acids. In addition, recent research in rats has clearly shown a functional parasympathetic innervation of WAT. There appears to be a distinct somatotopy within the parasympathetic nuclei: separate sets of autonomic neurones in the brain stem innervate either the visceral or the subcutaneous fat compartment. We therefore propose that the central nervous system (CNS) plays a major role in the hitherto unexplained regulation of body fat distribution. Parasympathectomy induces insulin resistance with respect to glucose and fatty acid uptake in the innervated fat depot and has selective effects on local hormone synthesis. Thus, the CNS is involved not only in the regulation of hormone production by WAT, but also in its hormone sensitivity. The developments in this research area are likely to increase our insights in the pathogenesis of metabolic disorders such as hypertriglyceridemia, diabetes mellitus type 2 and lipodystrophy syndromes. [source] A Potential Portal Flow in the Inner Ear,THE LARYNGOSCOPE, Issue 2 2007Morten Friis MD Abstract Objectives/Hypothesis: The aim of the present study was to visualize the flow direction of blood in the extraosseous part of the vein of the vestibular aqueduct (VVA) and to explore the effect of an induced obstruction in the distal part of the VVA before it merges with the sigmoid sinus. The endolymphatic sac has been implicated as a potential endocrine gland, which venules drain to the VVA. A reversal of the direction of flow in the VVA toward the inner ear could, through vestibular arteriovenous anastomosis, cause portal circulation in the inner ear. Study Design: The authors conducted an experimental animal study using in vivo fluorescence microscopy. Results: Obstructing the distal part of the VVA just before it empties into the sigmoid sinus immediately reverses the flow of blood in the VVA toward the inner ear. Conclusions: After an obstruction of the VVA, the drained venous blood from the endolymphatic sac may enter a portal circulation in the inner ear, which could cause disturbances in the endolymph homeostasis and potentially symptoms as seen in Meniere disease. [source] On the Structure of the Adrenal Gland of the Common Seal (Phoca vitulina vitulina)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2004H. Bragulla Summary The adrenal gland is a vitally important endocrine gland that occupies a central role in the regulatory mechanisms of the body metabolism. Environmental stress factors lead to permanent strain and overload of the body resulting in structural alterations of the adrenals that in turn are followed by hormonal imbalances. This leads to an increased susceptibility to bacterial and viral diseases. The recurrence of numerous fatalities in the different seal populations of the North Sea (during the years 1988, 1989 and 2002), of the Baikal Lake and Caspian Sea (during the years 2000 and 2001) were the motive for a morphological investigation of the species-specific structure of the adrenal gland of the common seal in order to differentiate environmental stress-induced pathological alterations from the physiological structure of this organ. The study was based on adrenals of 112 common seals (Phoca vitulina vitulina) using light microscopic and transmission and scanning electron microscopic methods. The phocine adrenal gland displays several structural characteristics. Originating from the connective tissue organ capsule, narrow and broad septa intersperse the adrenal cortex. These septa contain blastemata as a reserve for the regeneration of hormone-producing cortical cells. Such blastemata are also occurring in the form of an intermediate zone in between the zona glomerulosa and zona fasciculata in the phocine adrenal cortex. Another species-specific characteristic is an inverse part of the adrenal cortex encircling the central vein of the organ. These structural features have to be considered in assessment and definition of pathological alterations of the adrenals as observed in the form of exhausted blastema cell pools in the adrenocortex of seals perished in the mentioned phocine mass mortalities. [source] Effects of in utero exposure to 2,2,,4,4,,5,5,-hexachlorobiphenyl (PCB 153) on somatic growth and endocrine status in rat offspringCONGENITAL ANOMALIES, Issue 4 2008Kenichi Kobayashi ABSTRACT Exposure to polychlorobiphenyl (PCB) mixtures at an early stage of development has been reported to affect endocrine glands; however, little is known about the precise toxicological properties of individual PCB. The present study was undertaken to determine whether prenatal exposure to 2,2,,4,4,,5,5,-hexachlorobiphenyl (PCB 153), a di- ortho -substituted non-coplanar congener, affects postnatal development in rat offspring. Pregnant Sprague-Dawley rats (Crj: CD (SD) IGS) were given PCB 153 (0, 16, or 64 mg/kg/day) orally from gestational day (GD) 10 through GD 16, and developmental parameters in the male and female offspring were examined. We found no dose-dependent changes in body weight, body length (nose,anus length), tail length, or the weights of kidneys, testes, ovaries and uterus in offspring at 1 or 3 weeks of age. Liver weights were increased in the PCB 153,treated groups, although we observed a significant difference only in males. Anogenital distance was unaffected in the PCB 153,treated groups. We observed a significant dose-dependent decrease in the plasma concentrations of thyroxine and tri-iodothyronine, whereas those of thyroid-stimulating hormone were not significantly changed. In addition, there were no dose-dependent changes in plasma concentrations of growth hormone and insulin-like growth factor-I in any dose group. These findings suggest that prenatal exposure to PCB 153 (GD 10,16, 16,64 mg/kg/day) may alter the thyroid status in rat offspring to some extent without affecting somatic growth or its related hormonal parameters. [source] Environmental and heritable causes of cancer among 9.6 million individuals in the Swedish family-cancer databaseINTERNATIONAL JOURNAL OF CANCER, Issue 2 2002Kamila Czene Abstract The genetic and environmental components in 15 common cancers were estimated using the nationwide Swedish Family-Cancer Database. Tetrachoric correlations were used to describe similarity in cancer liability among family members. Structural equation modeling was used to derive estimates of the importance of genetic and environmental effects. Statistically significant estimates of proportion of cancer susceptibility, accounted for by genetic effects, were obtained for all studied cancers except for leukemia. The estimate was highest in thyroid cancer (53%), followed by tumors at endocrine glands (28%), testis (25%), breast (25%), cervix (22%), melanoma (21%), colon (13%), nervous system (12%), rectum (12%), non-Hodgkin lymphoma (10%), lung (8%), kidney (8%), urinary bladder (7%), stomach (1%) and leukemia (1%). The estimates of shared environmental effects ranged from 0% (cervix) to 15% (stomach). The childhood shared environmental effects were most important in testicular cancer (17%), stomach cancer (13%) and cervix in situ (13%). Our results indicate that environment has a principal causative role in cancer at all studied sites except for thyroid. The relatively large effect of heritability in cancer at some sites, on the other hand, indicates that even though susceptibility genes have been described at many cancer sites, they are likely to explain only part of the genetic effects. © 2002 Wiley-Liss, Inc. [source] Gs, Mutations in Fibrous Dysplasia and McCune-Albright Syndrome,JOURNAL OF BONE AND MINERAL RESEARCH, Issue S2 2006Lee S Weinstein Abstract Fibrous dysplasia (FD) is a focal bone lesion composed of immature mesenchymal osteoblastic precursor cells. Some FD patients also have hyperpigmented skin lesions (café-au-lait spots), gonadotropin-independent sexual precocity, and/or other endocrine and nonendocrine manifestations (McCune-Albright syndrome [MAS]). MAS results from somatic mutations occurring during early development, resulting in a widespread mosaic of normal and mutant-bearing cells, which predicts that the clinical presentation of each patient is determined by the extent and distribution of abnormal cells. These mutations encode constitutively active forms of Gs,, the ubiquitously expressed G protein ,-subunit that couples hormone receptors to intracellular cAMP generation. These mutations lead to substitution of amino acid residues that are critical for the intrinsic GTPase activity that is normally required to deactivate the G protein. This leads to prolonged activation of Gs, and its downstream effectors even with minimal receptor activation. This explains why MAS patients have stimulation of multiple peripheral endocrine glands in the absence of circulating stimulatory pituitary hormones and increased skin pigment, which is normally induced by melanocyte-stimulating hormone through Gs,/cAMP. Similar mutations are also present in 40% of pituitary tumors in acromegaly patients and less commonly in other endocrine tumors. FD results from increased cAMP in bone marrow stromal cells, leading to increased proliferation and abnormal differentiation. Parental origin of the mutated allele may also affect the clinical presentation, because Gs, is imprinted and expressed only from the maternal allele in some tissues (e.g., pituitary somatotrophs). [source] Cranial magnetic resonance imaging of Wolfram (DIDMOAD) syndromeJOURNAL OF MEDICAL IMAGING AND RADIATION ONCOLOGY, Issue 2 2005E Pakdemirli Summary Wolfram syndrome is a rare neurodegenerative disorder characterized by diabetes insipidus, diabetes mellitus, optic atrophy and deafness (DIDMOAD). A wide spectrum of abnormalities of the central nervous system, urinary tract and endocrine glands is also observed. We report cranial MRI findings in a 32-year-old female patient with Wolfram syndrome. In addition to the classical features, including absence of the normal high signal of the neurohypophysis, atrophy of visual pathways, the brainstem, cerebellum and cerebral cortex, we observed bilateral hyperintensity on proton density- and T2- weighted images related to the optic radiations in the periventricular white matter of the temporal and parieto-occipital lobes, which may reflect gliosis pathologically. [source] Role of adrenocorticotropic hormone in the development and maintenance of the adrenal cortical vasculatureMICROSCOPY RESEARCH AND TECHNIQUE, Issue 3 2003Michaël Thomas Abstract The adrenal cortex is a highly vascularized endocrine tissue. A dense network of blood capillaries centripetally irrigates the adrenal gland, allowing every endocrine cell to be in contact with an endothelial cell. The pituitary hormone ACTH controls the coordinated development of the vasculature and the endocrine tissue mass. This suggests that paracrine secretions between steroidogenic adrenocytes and capillary endothelial cells participate in the control of adrenocortical homeostasis. Besides its effect on the vascular tone of arteries, ACTH induces the expression of the angiogenic cytokine VEGF-A (vascular endothelial growth factor-A) in primary cultures of adrenocortical cells. This growth factor is a specific mitogen for endothelial cells and is likely to mediate the hormonal control of adrenocortical vascularization through a paracrine mechanism. The newly discovered angiogenic factor EG-VEGF (endocrine-gland-derived vascular endothelial growth factor), the expression of which is restricted to endocrine glands and which is preferentially mitogenic for endocrine tissue-derived endothelial cells, is another candidate mediator of great potential interest. Microsc. Res. Tech. 61:247,251, 2003. © 2003 Wiley-Liss, Inc. [source] Microarray analysis of liver gene expression in iron overloaded patients with sickle cell anemia and beta-thalassemia,AMERICAN JOURNAL OF HEMATOLOGY, Issue 6 2009Jonathan M. Flanagan Chronic transfusion therapy is used clinically to supply healthy erythrocytes for patients with sickle cell anemia (SCA) or beta-thalassemia major (TM). Despite the benefits of red blood cell transfusions, chronic transfusions lead to iron accumulation in key tissues such as the heart, liver, and endocrine glands. Transfusion-acquired iron overload is recognized as a cause of morbidity and mortality among patients receiving chronic transfusions. At present, there is little understanding of molecular events that occur during transfusional iron loading and the reasons for the large inter-individual variation observed clinically in transfusion-acquired iron accumulation. To address these issues, we examined whether any liver-expressed genes in SCA or TM patients with transfusional iron overload were associated with the degree of iron accumulation. Specifically, we performed microarray analysis on liver biopsy specimens comparing SCA patients with mild or severe iron overload and also compared SCA with TM patients. Fifteen candidate genes were identified with significantly differential expression between the high and low liver iron concentrations. SCA patients and 20 candidate genes were detected between the SCA and TM patient comparison. Subsequent quantitative PCR experiments validated 12 candidate genes; with GSTM1, eIF5a, SULF2, NTS, and HO-1 being particularly good prospects as genes that might affect the degree of iron accumulation. Future work will determine the baseline expression of these genes prior to transfusional iron overload and elucidate the full impact of these genes on the inter-individual variation observed clinically in transfusion-acquired iron accumulation. Am. J. Hematol. 2009. © 2009 Wiley-Liss, Inc. [source] Parthenium hysterophorus induced changes in neurotransmitter levels in mouse brainPHYTOTHERAPY RESEARCH, Issue 2 2007Sabita Verma Abstract Parthenium hysterophorus (10 mg/0.1 ml/kg body weight) was administered daily to 20 adult male mice and levels of 5-hydroxytryptamine, noradrenaline and dopamine in total brain were quantified on days 31 and 61 after administration. All neurotransmitter levels were decreased significantly, with the effects more prominent in the later part of the experiment. The results suggest that Parthenium hysterophorus interferes in the functioning of the hypothalamo,hypophyseal axis by impairing the biogenic amine levels which may in turn affect the physiology of the peripheral endocrine glands. Copyright © 2006 John Wiley & Sons, Ltd. [source] Red blood cell transfusions and iron overload in the treatment of patients with myelodysplastic syndromesCANCER, Issue 5 2008Elias Jabbour MD Abstract BACKGROUND Approximately 15,000 new cases of myelodysplastic syndromes (MDS) are expected in the United States each year. METHODS The mainstay for the management of myelodysplastic syndromes (MDS) is supportive therapy with red blood cell (RBC) transfusions to improve the patient's quality of life. RBC transfusions enable adequate tissue oxygenation and increase hemoglobin levels, improve fatigue, and improve the physical and intellectual activity of patients. Up to 90% of patients with MDS will receive RBC transfusions during the course of their disease, and many will become chronically dependent on transfusions to manage their anemia. These transfusions lead to an accumulation of excess iron that, in turn, can develop into a condition known as iron overload, causing clinical consequences like hypertransaminasemia and cirrhosis, dilated cardiomyopathy, and progressive dysfunction of the endocrine glands. RESULTS Studies in patients with MDS have indicated that iron overload because of RBC transfusions was an independent, adverse prognostic factor for overall survival (OS) and leukemia-free survival (LFS): OS and LFS were significantly shorter in transfusion-dependent patients with MDS than in those who were not transfusion dependent. CONCLUSIONS Although the National Comprehensive Cancer Network guidelines for the treatment of patients with MDS recommend the use of RBC transfusions as supportive care, they further recommend that the iron burden of transfused patients be monitored regularly and that iron chelation therapy be considered to maintain serum ferritin levels of <1000 ng/mL. Cancer 2008. © 2008 American Cancer Society. [source] Effects of calcitriol on the immune system: new possibilities in the treatment of glomerulonephritisCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 11 2003Vincenzo Panichi Summary 1.,1,25-Dihydroxyvitamin D3 (1,25(OH)2D3), the hormonal form of vitamin D, is widely appreciated to play a central role in calcium and phosphate homeostasis. However, it is becoming increasingly clear that the sterol also play an important role in the regulation of cellular growth, haematopoietic tissues and the immune system, as well as in the modulation of hormone secretion by several endocrine glands. 2.,In the present review, some of the mechanisms by which 1,25(OH)2D3 regulates immune function are highlighted. Moreover, a number of studies on the effects of calcitriol in several experimental animal models of renal disease are reported, suggesting new possibilities in the therapy of glomerulonephritis. [source] | ||||||||||||||||||||||