PDF Archive search engine
Last database update: 06 May at 21:36 - Around 76000 files indexed.
Gene expression changes in response to dehydration indicated up-regulation of cellular recycling pathways including the ubiquitin-mediated proteasome and autophagy, with concurrent down-regulation of genes involved in general metabolism and ATP production.
Maintaining life is viewed as the ability to maintain the level of metabolites from intermediate metabolism within discrete and functional ranges (Mishur and Rea, 2012).
Regulation of metabolism by changes in mitochondrial number and capacities often take place during cold acclimation (e.g.
Endocrinology and Metabolic Processes Regulation Athletic Success via Biochemical Supplementation ● ● ● Author: Eva Date: 20160130 Rev: 1.2.1 Note : This is a work in progress for my own purposes. It is currently evolving. Resources are listed in brackets with source links at the end of the document. If otherwise not noted/bracketed, the writing is from the author’s own contextual knowledge. Conclusions are bolded where deemed relevant to a topic. A Quick Intro to Endocrinology and Metabolism Prior to getting into any concepts or useful conclusions there are several background terms and elements that the reader should be familiar with. We’ll start with fundamentals and touch on several core elements before introducing the cyclical elements of endocrinology and the metabolic cycle. These terms, concepts, and cycles are essential to understanding how one’s diet and hormonal balances are controlled by diet, which in turn defines how our physical form is capable of performance, growth, decline, and overall change. Fundamental Terms The following terms will come up occasionally throughout this document and, as such, one would benefit from knowing the context around them prior to continuing. Endogenous Originating from within an organism, not attributable to any external or environmental factor. eg: biologically produced estrogen created by the ovaries. Exogenous Originating from outside an organism, caused by an agent or organism outside the body. eg: hormone replacement medication taken by injection. MacroNutrients The combined requirements of base nutrition required to sustain healthy human existence. There are three primary macronutrients: protein, fat, and carbohydrate.  Macronutrients are defined as a class of chemical compounds which humans consume in the largest quantities (must be above a threshold amount) and which provide humans with the bulk of energy.  CNS, The Central Nervous System The central nervous system is composed of the brain and spinal cord. Your brain and spinal cord serve as the main "processing center" for the entire nervous system, and control all the workings of your body. PSN, The Peripheral Nervous System The peripheral nervous system consists of the nerves that branch out from the brain and spinal cord. These nerves form the communication network between the CNS and the body parts. The peripheral nervous system is further subdivided into the somatic nervous system and the autonomic nervous system. The somatic nervous system consists of nerves that go to the skin and muscles and is involved in conscious activities. The autonomic nervous system consists of nerves that connect the CNS to the visceral organs such as the heart, stomach, and intestines. It mediates unconscious activities. Endocrinology A branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental events proliferation, growth, and differentiation, and the psychological or behavioral activities of metabolism, growth and development, tissue function, sleep, digestion, respiration, excretion, mood, stress, lactation, movement, reproduction, and sensory perception caused by hormones. Metabolism The set of lifesustaining chemical transformations within the cells of living organisms. These enzymecatalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. Pharmacokinetics Sometimes described as what the body does to a drug, refers to the movement of drug into, through, and out of the body the time course of its absorption, bioavailability, tissue distribution, metabolism, and excretion.  Endocrinology: Communication and Message Relays The endocrine system is a collection of glands that secrete hormones directly into the circulatory system to be carried towards distant target organs. The major endocrine glands include the pineal gland, pituitary gland, pancreas, ovaries, testes, thyroid, parathyroid, hypothalamus, gastrointestinal tract, and adrenal glands. The Role of Hormones in Endocrinology Hormones are the body’s signaling molecules that are used to communicate between organs and tissues. They regulate physiological and behavioral activities, such as digestion, metabolism, respiration, tissue function, sensory perception, sleep, excretion, lactation, stress, growth and development, movement, reproduction, and mood. The particulars of each hormone are covered in the section titled “Neurotransmitters, Hormones, and Histamines”. An Overview of Hormonal Biosynthesis Receptors In biochemistry and pharmacology, a receptor is a protein molecule usually found embedded within the plasma membrane surface of a cell that receives chemical signals from outside the cell.
Cold tolerance increases through the accumulation of metabolites with an assumed cryoprotective function and the depression of metabolites involved in energy metabolism.
A recent transcriptomic study suggested that cold tolerance of winter morphs is associated with an upregulation of genes involved in carbohydrates’ metabolism (Shearer et al., 2016).
As an Intern in Veterans General Hospital-Taipei 1974-1975 As an Internist since 1975 up to now As an Endocrinologist since 1980 Fellow, Division of Endocrinology and Metabolism The Johns Hopkins University School of Medicine, Baltimore, MD, USA July 1982-June 1983 Present Appointment :
Metabolic pathway analyses indicated a remodeling of various processes, including purine metabolism and aminoacyl tRNA biosynthesis.
A large set of proteins were modulated during diapause and these were involved in various functions such as remodeling of cytoskeleton and cuticle, stress tolerance, protein turnover, lipid metabolism and various metabolic enzymes.
Rearing on high-sugar doses induced system-wide metabolic alteration associated with carbohydrate metabolism imbalance, a developmental delay and a fresh mass reduction.
The reduced mortality under FTR was associated with up-regulation of several proteins playing key roles in energy metabolism (glycolysis, TCA cycle, synthesis and conversion of ATP), protein chaperoning (Hsp70/Hsp90), and protein degradation (proteasome).
melanogaster, and thereby affect both lipid and carbohydrate metabolism (Ridley et al., 2012;
doi:10.1242/jeb.164806 Loss of ion homeostasis Restoration of ion gradients Loss of metabolic homeostasis Restoration of metabolic homeostasis Cell death Dysfunctional membranes and bound enzymes Accumulation of toxic compounds ATP deficiency Metabolic (enzyme) inhibition Alteration of membranes Unfolding of proteins Boost of energy metabolism Detoxification Protective (stabilizing) solutes Protein chaperoning Restoration of membrane properties DNA damage Cytoskeleton disassembly CLT/cold injury zone Cytoskeleton remodeling FTR recovery period (e.g.
Drew Lyons Micah Mansfield Animal Design Project #1 Thrinaxodon Thrinaxodon, a synapsid cynodont, was a small, mammallike reptile that lived 253 million years ago in the late Permian. It disappeared during the extinction event 245 million years ago at the end of the Olenekian portion of the Triassic period. The discovery of Thrinaxodon was important as a transitional fossil in the evolution of mammals. Cladogram showing the relationship of Thrinaxodon to mammals (Botha and Chinsamy, 2005). Fossils of Thrinaxodon were found in modern day South Africa and Antarctica, providing strong evidence that Thrinaxodon once roamed an area that combined these land masses because the physiology of Thrinaxodon suggests it could neither swim long distances nor fly. Current day separation of fossils by a vast ocean helped scientists understand plate tectonics and the existence of a supercontinent called Pangea. Pangea: Image taken http://www.metafysica.nl/wings/wings_3a.html. The inserted black box shows the location where Thrinaxodon fossils were found and where it likely lived during the Late Permian and Early Triassic periods. Thrinaxodon was 30 to 50 cm in length, 10 cm tall, had a large, flat head and legs somewhat characteristic of fossorial animals that splayed out slightly from the torso, creating a 15 cm wide stance. Indentations in fossils of its skull provide strong evidence that Thrinaxodon had whiskers. Whiskers are a very beneficial adaptation for predators at night because it would allow the animal to better sense its surroundings in low light conditions, giving it a competitive advantage over its prey and other predators that compete for similar resources. If it had whiskers then there may have been fur as well, indicating that it was homeothermic since fur functions to insulate the animal from the outside conditions, so the animal’s temperature is being driven more by internal processes. Being one of the earliest mammallike organisms with fur, it was most likely less dense than the fur modern mammals have (prehistoricwildlife.com, 2011). Thrinaxodon had many mammalianlike adaptations that in ways allowed it to function in similar ways as modern day mammals, suggesting it was a distant ancestor of mammals. Key morphological innovations allowed for increased metabolic rates and its survival through the PermianTriassic extinction event. These included features in Thrinaxodon’s skeleton such as the addition of lumbar vertebrae on the spine and the shortening of thoracic vertebrae, one additional occipital condyle, the presence of a masseteric fossa, and a hardened secondary palate. The segmentation of the spine allowed for increased weight bearing and movement in the lower back. Segmentation, in combination with the absence of ribs in the lower abdomen, suggests the presence of a diaphragm. The ribs now form a chest cavity that houses the lungs and provides an attachment surface for the diaphragm, which allows for increased respiration efficiency and minimum energy expenditure due to breathing (Cowen, 2000). The addition of an occipital condyle functioned to increase articulation with the atlas vertebrae and permitted more movement, which allowed it to be more aware of its surroundings and potential predators. The masseteric fossa presented a larger surface area for muscle attachment on the dentary bone to make chewing and processing food more efficient, which in turn leads to a faster metabolism. One of the most important adaptations, especially for carnivores, is the presence of the hardened secondary palate that allowed for breathing through the nose while chewing, which is important in order to take down struggling prey or chew for a longer period of time while still maintaining the ability to breathe (prehistoricwildlife.com, 2011). Thrinaxodon also possesses the beginnings of a brain case, which is shown by the epipterygoid bone expanding to alisphenoidlike proportions, as well as nasal turbinates, which are “convoluted bones in the nasal cavity that are covered by olfactory sense organs” (Cynodontia). The teeth of Thrinaxodon display the mammalian traits of thecodontia (teeth present in the socket of the dentary) and differentiated teeth. In its tooth differentiation, the three cusped post canines that Thrinaxodon was named after were important so it could thoroughly chew its food and decrease the time of digestion. This also suggests a faster metabolism that was more like modern mammals, as well as an important evolutionary step towards the tribosphenic molar (Estes, 1961). Due to this increased metabolism, Thrinaxodon was eurythermic, meaning it was able to function in a broad range of temperatures, and was essentially homeothermic.