Endocrine organs

The ‘Endocrine organs’ chapter focuses on the major endocrine systems of the body, including the pituitary, thyroid, pancreas, and adrenal glands, as well as other sites of hormone productions such as the gastrointestinal tract, adipose tissue, heart, and kidneys. The normal roles and functions of the hormones are considered, including hormones influencing calcium, phosphate, and bone, along with pathologies such as diabetes, Cushing’s syndrome, and hyperaldosteronism. Finally, coordinated hormonal responses are discussed, in terms of the response to stress, including the alarm reaction (‘fight or flight’), and the physiological effects of chronic stress.

Probability Model for Stress Condition Assessment

The article presents a model giving consideration to probability nature of the transition from one stage to another based on the conceptual approach to understanding stress as stages: an alarm reaction, resistivity and exhaustion stages suggested by H. Selye. The author examined some features of its formalization in the framework of open system theory. The arguments for analytical expressions determining probability nature of the transition from one stress condition to another have been presented. The author determined time intervals of the transition to a resistivity stage depending on the stress tolerance index of a subject. The article gives factors establishing stress parameters in terms of its destructive impact upon a subject. The author suggested an analytical framework providing probability assessment indicating the presence of a subject at a certain stage of a stress condition. The article suggests some ways to apply the results obtained.

Evaluation of Low-Cost Hydrogen Sulfide Monitors for Use in Livestock Production

Direct-reading gas monitors warn workers of the risk of potentially fatal hydrogen sulfide (H2S) exposures that may arise during manure handling. Low-cost, low-maintenance H2S monitors are available from many manufacturers, but differences in their features and performance make selection challenging for farmers. Moreover, little information is available on the practical maintenance and performance of these devices in agricultural environments. The objective of this study was to provide information to agricultural workers to aid in the selection, maintenance, and use of low-cost H2S monitors. This laboratory study evaluated the performance of several low-cost monitors over a simulated period of use of one year in a swine barn. Four models were exposed to H2S concentrations of 1 to 10 ppm over 18 weeks to examine the drift in reported concentration and changes in the alarm reaction time. Over the simulated barn year, the performance of alarm-only monitors declined faster than that of monitors displaying the H2S concentration. Of concern was the high-level (20 ppm) alarm failures after an equivalent of 139 days (Altair) and 289 days (BW Clip) in a swine barn, well within the monitor’s reported shelf-life. Models displaying concentration exhibited fewer failures but were inaccurate in the displayed concentration when challenged with 20 ppm of H2S. The T40 Rattler provided consistently higher readings (+2.3 ppm), and the Pac 3500 showed consistently lower readings (-3.4 ppm) when challenged with 20 ppm. This study confirms the need for routine bump tests for these low-cost monitors to ensure that the monitor reacts to the presence of H2S, even if the manufacturer does not recommend this procedure. Most importantly, agricultural workers should inspect and bump test these monitors prior to any potentially high-risk activity, such as manure agitation, pumping, or pressure washing, to ensure that the monitor appropriately detects and warns users. Keywords: Calibration, Direct-reading monitors, H2S, Hydrogen sulfide monitors, Manure gas, Safety, Sensors.

Egy „furcsa ember” – Selye Jánosról magyar kapcsolatainak tükrében

Hans Selye made a great impact on the Hungarian medical, scientific and public life. His first Hungarian publication about the alarm-reaction appeared 1938 in the Orvosi Hetilap. His Hungarian relationship was quite extensive after the war as he published, gave lectures, and accepted Hungarian students for specialized training in his Canadian institute saw. The rich documents in archives about Selye are currently being processed and those will surely shed light on Selye’s life in further details. Orv. Hetil., 2015, 156(35), 1436–1440.

PENDEKATAN PSIKONEUROIMUNOLOGI

AbstrakPsikoneuroimunologi merupakan konsep terintegrasi mengenai fungsi regulasi-imun untuk mempertahankan homeostasis. Untuk mempertahankan homeostasis, sistem imun berintegrasi dengan proses psikofisiologik otak, dan karena itu mempengaruhi dan dipengaruhi otak. Melalui pendekatan ini telah mulai dipahami mekanisme interaksi antara perilaku, sistem saraf, sistem endokrin, dan fungsi imun. Komponen perilaku dari interaksi ini melibatkan kondisioning Pavlov pada peningkatan maupun penekanan antibodi dan respon imun seluler. Kondisioning ini berekspresi sebagai efek pengalaman stress terhadap fungsi imun. Selanjutnya diketahui bahwa mekanisme terintegrasi ini berlangsung dalam ritme yang berkaitan dengan ritme lingkungan seperti ritme Sirkadian. Respon stress berkelanjutan berekspresi sebagai sindroma adaptasi umum. Sebagai respon akut dimulai dengan initial brief alarm reaction. Dalam tahap ini peningkatan sekresi cortisol pada aksis Hypothalamic-Pituitary-Adrenal (HPA) menimbulkan supresi pada sebagian besar fungsi imun dan peningkatan aktifitas sistem simpatis. Bila stress tidak dapat diatasi secara efektif, tahap kedua prolonged resistance period akan dimulai, dimana aktivasi aksis HPA akan menurun tetapi tidak pernah mencapai kondisi basal. Kegagalan berkelanjutan untuk mengatasi stress akan berakhir pada terminal stage of exhaustion and death. Aplikasi medis psikoneuroimunologi akan meningkatkan efektifitas terapi penyakit keganasan, gangguan kardiovaskular, penyakit infeksi, trauma fisik, transplantasi, dan gangguan jiwa.Kata kunci: aksis HPA, antibodi, aplikasi medis, cortisol, homeostasis, melawan atau lari, otak, Pavlov, perilaku, psikofisiologik, psikoneuroimunologi, sindroma adaptasi umum, sistem imun, sistem LS-NA, respon stress, ritme SirkadianAbstractPsychoneuroimmunology is an integrated concept of immune-regulatory function. To maintain homeostasis, the immune system is integrated with psychophysiological processes of the brain, and is therefore influenced by and capable of influencing the brain. Mechanism of interaction among behavior, neural, endocrine, and immune functions in adaptation to environmental stressors have come to light. The behavioral components of this interaction involve the Pavlov conditioning both in the enhancement and supression of antibody-and cell-mediated immune responses. This conditioning expressed as effects of stressful experiences on immune function. This integrated mechanism operated in a rhythmTINJAUAN PUSTAKA91related to environmental rhythm such as Circadian rhythm. Prolonged stress response will be expressed as general adaptation syndrome. As an acute response it will begin with initial brief alarm reaction. In this stage increased cortisol secretion in Hypothalamic-pituitary-adrenal (HPA) axis resulted in supression of main immune function and arousal of sympathetic system If the stress can not be coped effectivelly, a second stage of prolonged resistance period will begin, in which HPA axis activation will be decreased but never reach the basal condition. Continued failure to cope with the stress will end in terminal stage of exhaustion and death.Medical application of psychoimmunology can enchance the effectivity of the treatment of malignancy, cardiovascular disorder, infectious diseases, physical trauma, transplantation, and mental disorder.Key word : antibody, behavioral, brain, Circadian rhythm, cortisol, fight or flight, general adaptation syndrome, homeostasis, HPA axis, immune system, LC-NA system, medical application, Pavlov, psychoneuroimmunology, psychophysiological, stress responses