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Evaluation and Investigation of Pituitary Disease
Published in R James A England, Eamon Shamil, Rajeev Mathew, Manohar Bance, Pavol Surda, Jemy Jose, Omar Hilmi, Adam J Donne, Scott-Brown's Essential Otorhinolaryngology, 2022
Hypopituitarism is suggested where both the target hormone (e.g. T4) and the tropic hormone (e.g. TSH) are low. In most cases, dynamic testing is also required to prove that pituitary reserve is affected. Multiple dynamic tests can be performed simultaneously.
Basic medicine: physiology
Published in Roy Palmer, Diana Wetherill, Medicine for Lawyers, 2020
There are two main sorts of gland in the body. Exocrine glands, such as the salivary and sweat glands, secrete their juice into a duct, whereas endocrine or ductless glands secrete hormones directly into the bloodstream. Hormones are proteins that act as chemical messengers, travelling in the blood to modulate the activity of a target organ that possesses the relevant hormone receptor. Endocrine tissue is found in many different organs, but it is concentrated in certain glands of which the pituitary is the most important. The pituitary gland is located inside the skull just below the brain and contains two main lobes. The anterior lobe secretes tropic hormones that control the activity of several other glands, including the thyroid, adrenal, breast, ovary and testis; it also secretes growth hormone, which affects the growth of many organs. The posterior pituitary secretes vasopressin and oxytocin, which act on the kidney and uterus, respectively. Pituitary insufficiency therefore has widespread effects. Pituitary secretion is controlled by a feedback system: rising blood levels of hormones secreted by the target organ in response to the pituitary hormone inhibit the secretion of that tropic hormone.
Hypothalamic Neuroendocrine Regulation
Published in George H. Gass, Harold M. Kaplan, Handbook of Endocrinology, 2020
Prolactin is an anterior pituitary hormone that acts directly on target tissue rather than as a tropic hormone. Although prolactin plays many physiologic roles in other animals, its known function in humans is postpartum stimulation of milk production. It is, however, present in males and nonpregnant females, where its function is unknown. In addition, bursts of prolactin release occur in sleep and during stress.95 Unlike other pituitary hormones, prolactin is regulated mainly by tonic inhibition rather than by intermittent stimulation. The neurotransmitter dopamine appears to fit the criteria of a prolactin releasing inhibitory factor. Hence, prolactin’s principal inhibitor is dopamine. Prolactin enhances dopamine secretion and thus inhibits its own secretion. Other known physiologic inhibitors are somatostatin and triiodothyronine. Prolactin release is stimulated by serotonin, acetylcholine, opiates, estrogens, TRH, and angiotensin-II. Which of these is physiologically important is not known.
A systematic review and meta-analysis of the correlation between polycystic ovary syndrome and irritable bowel syndrome
Published in Gynecological Endocrinology, 2023
Zhaokang Wei, Zuhui Chen, Wenle Xiao, Gangjie Wu
Psychiatric disturbances, such as anxiety and depressive disorders are common in IBS and PCOS patients and may have a role in the pathogenesis of IBS in PCOS patients, potentially acting as a bidirectional factor [46]. A recent review reported that mood disorders are prevalent in adult and adolescent women with PCOS [47, 48]. In addition, a previous case-control study indicated that PCOS women have an elevated risk of psychiatric disturbances [14]. The brain-gut axis may account for the relationship between psychological disorders and IBS. There is also evidence suggesting that estrogen and progesterone are associated with the increase in pain modulation and the release of stress-related adreno-cortico-tropic-hormone (ACTH), related to the higher stress responses as well as anxiety in women with IBS with activating the hypothalamic-pituitary-adrenal axis [25]. Therefore, it can be inferred that the high incidence of mood disorders in patients with PCOS may be attributed to a certain extent to the involvement of sex hormones in pain regulation and increased stress, which may promote the development of IBS.
Risk of osteoporosis in microscopic colitis
Published in Postgraduate Medicine, 2018
Signe Wildt, Lars K. Munck, Sabine Becker, Helle Brockstedt, Ole K. Bonderup, Mette F. Hitz
Bone mineral status was evaluated by measuring BMD by Dual Energy X-ray Absorptiometry (DXA) in hip and spine and measuring bone turnover markers in blood. Bone-specific alkaline phosphatase, procollagen type I N-terminal propeptide (PINP), and osteocalcin as bone formation markers, cross-linked C-telopeptide (CTX) as bone resorption marker. The adrenocortical axis was evaluated by measuring adrenocortico-tropic hormone (ACTH) in patients and controls at inclusion, and an ACTH stimulation test was performed in all patients. For all patients, disease activity score, quality of life score and data concerning budesonide use, and concomitant medication were registered at inclusion and every 3 months, and DXA scan and measurement of bone turnover markers were repeated one year after inclusion. Patients and controls diagnosed with vitamin D deficiency, osteopenia, or osteoporosis were offered treatment according to national treatment recommendations [5]. Participants provided written informed consent, and the study was approved by the local ethical committee (SJ-301) and the local data management committee (39-2016).
Potential of dry powder inhalers for tuberculosis therapy: facts, fidelity and future
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2018
Piyush Mehta, C. Bothiraja, Shivajirao Kadam, Atmaram Pawar
Numerous therapeutic proteins, peptides and vaccine have been utilized in day-to-day clinical practice. More than 60 proteins and peptides based formulations are approved across the globe and continue to enter into various clinical phases [88]. To name few, insulin to treat diabetes, adrenocorticotropic hormone (a polypeptide tropic hormone) used as diagnostic agent, human growth hormone (hGH) to supplement hormone deficiency, leuprorelin to treat prostate and breast cancer as well as calcitonin (linear polypeptide hormone) and parathyroid hormone (PTH) to treat osteoporosis. Because of the recent advances in molecular/cell biology and biotechnology with better understanding of the physiopathology of many diseases, cellular components are expected to become of growing importance. But a major problem of these components is the need to use parenteral route for administration. This is primarily because of the existence of various proteases enzymes and harsh gastrointestinal environment, leading to physico-chemical degradations and consequently loss of therapeutic activity. Pulmonary delivery of these therapeutic components could represent an option to parenteral delivery. Direct administration to the pulmonary airways for local treatment permits high doses of protein or peptides drugs to be delivered while preventive systemic adverse side effects. Pulmonary delivery can be utilized to provide systemic action of few proteins and peptides. Furthermore, some enzymes present at the thin epithelial membrane and the air-lung interface allow permits effective absorption of inhaled biomolecules. But, administration of proteins or peptides to the pulmonary airways represents few major challenges. An initial problem with any inhaled therapeutics is the need to supply the drug as solid or liquid microparticles (<5 µm) to reach the pulmonary airways. Another important problem, which is specific to inhaled proteins and peptides, is that they can experience physicochemical degradation during handing or tailoring microparticles such as, exposure to extreme pH, temperatures and diverse stresses. These physicochemical degradations can lead to loss of therapeutic activity. Another concern with these biomolecules is their large molecular weight, hydrophilicity of proteins and pulmonary biological fate [89–91]. To surpass these all issues, various researchers tried and tested different strategies for pulmonary delivery of proteins and peptides. An overview of these strategies along with their key achievements is listed in Table 7.