visceral adipose tissue raises a handful of sensible questions. This page answers them in order, starting with the fundamentals and moving to applications.
This page was last updated on 2025-12-24 and is reviewed periodically as new material appears.
Tesamorelin is a synthetic analog of growth hormone-releasing hormone, a peptide hormone produced by the hypothalamus. The molecule retains the 44-amino-acid sequence of human GHRH and carries a trans-3-hexenoyl modification at its N-terminus. This modification increases resistance to enzymatic degradation and extends the peptide's functional stability relative to native GHRH. The compound is supplied as a lyophilized powder for reconstitution and subcutaneous administration in clinical settings. Its development code was TH9507, and it belongs to the GHRH analog class. It is not a growth hormone product; instead, it acts upstream to stimulate endogenous growth hormone release.
Clinical interest in tesamorelin arose from the need to address visceral adiposity in people living with HIV. Antiretroviral therapy improved survival but was associated in some patients with central fat accumulation, altered lipid profiles, and metabolic complications. This condition, often called HIV-associated lipodystrophy, involves excess visceral adipose tissue that is difficult to manage through diet and exercise alone. Investigators evaluated tesamorelin because GHRH analogs can stimulate growth hormone secretion and influence fat distribution without direct liposuction or invasive procedures.
Tesamorelin is a synthetic peptide analog of growth hormone-releasing hormone (GHRH). Its sequence corresponds to the 44-amino-acid form of human GHRH with a trans-3-hexenoyl group attached to the N-terminal tyrosine. This modification slows enzymatic cleavage and extends the peptide's activity relative to the native hormone. The compound is produced by solid-phase peptide synthesis and supplied as a lyophilized powder. Researchers classify it as a GHRH receptor agonist. Its structure places it in the same family as other growth hormone secretagogues that act on the pituitary.
Binding of tesamorelin to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and the release of growth hormone into circulation. Because the peptide acts upstream of the growth hormone axis, its effects are partly mediated by hepatic insulin-like growth factor 1 (IGF-1) production. The pulsatile character of endogenous growth hormone secretion is preserved rather than replaced. Whether amplified signaling produces effects beyond those of native GHRH remains an area of ongoing investigation.
A documented effect of tesamorelin is a reduction in visceral adipose tissue in some study populations. Researchers have reported decreases in trunk fat measured by computed tomography alongside changes in lipid markers. The mechanism is thought to involve growth hormone-mediated lipolysis, though the precise contribution of direct versus indirect pathways is not fully resolved. Studies have generally examined defined groups over finite periods, so long-term outcomes are less well characterized. Findings have not been uniform across all trials.
| Property | Value | Notes |
|---|---|---|
| Molecular weight | Approximately 5,136 Da | Based on the 44-amino-acid peptide backbone and N-terminal modification. |
| Appearance | White to off-white lyophilized powder | Usually supplied in single-use vials for reconstitution. |
| Solubility | Freely soluble in water; slightly soluble in some organic solvents | Peptide nature supports aqueous reconstitution. |
| Typical storage | 2–8 °C, protected from light | Refrigeration reduces degradation; avoid freezing unless specified. |
| Common analytical method | Reverse-phase high-performance liquid chromatography | Used for identity, purity, and quantification. |
| Synonyms | Tesamorelin, TH9507, GHRH(1-44) analog | Generic descriptors; avoid proprietary names. |
tesamorelin 是一种人工合成的四十四肽，序列与内源性生长激素释放激素（GHRH）的 1-44 片段一致，区别在于 N 端加接了一个反式-3-己烯酰基。该修饰抑制二肽基肽酶 IV 的快速切割，从而延长分子在循环中的存留时间。作为肽类分子，它难以经胃肠道吸收，文献中讨论的均是注射途径。分类上通常把它归为 GHRH 类似物，以区别于生长激素本身。
作用位置在垂体前叶。tesamorelin 与 GHRH 受体结合后激活腺苷酸环化酶，升高细胞内 cAMP，再经蛋白激酶 A 通路促进生长激素的合成与释放。由于它作用于内源调控节点，生长激素仍以脉冲方式分泌，而不是被持续抬升到固定水平。生长激素随后在肝脏等组织诱导胰岛素样生长因子 1 产生，构成完整的生长激素轴响应。
Receptor-level activity begins when the peptide binds the GHRH receptor, a class B G-protein-coupled receptor found on pituitary somatotroph cells. Occupancy triggers Gs-mediated activation of adenylyl cyclase and a rise in intracellular cyclic AMP, which in turn promotes synthesis and pulsatile release of growth hormone. Because the compound acts upstream of the growth hormone axis rather than supplying hormone directly, its effect depends on intact pituitary function. Binding studies in cell culture and animal models have established this pathway; the detailed kinetics of receptor recycling in humans remain less well characterized.
Physicochemical behavior is dominated by the peptide backbone. The molecule is hydrophilic and carries a net positive charge near neutral pH, owing to several arginine and lysine residues. In solution it adopts a largely unstructured conformation, and aggregation is a known concern for peptide products of this size. Oxidation of methionine and deamidation of asparagine or glutamine residues are the principal chemical degradation routes. These liabilities shape how the material is formulated, handled, and analyzed, and they explain why lyophilized presentations are common in research settings.
Clinical study of tesamorelin has centered on adults with HIV-associated lipodystrophy, a condition in which abdominal fat accumulates while peripheral fat is lost. In controlled trials, treated participants showed reductions in visceral adipose tissue measured by imaging, alongside modest shifts in some lipid values. Effects on subcutaneous fat were smaller and less consistent across studies. Whether these changes translate into fewer cardiovascular events remains an open question, because the trials were not designed or powered to answer it.
Tesamorelin is a synthetic peptide that acts as an analog of growth hormone-releasing hormone, a natural hypothalamic signal. Its sequence corresponds to the forty-four amino acid form of the human hormone, with a small acyl group attached near the amino terminus. That modification slows enzymatic breakdown and extends the time the peptide remains active in circulation. The compound was developed as a pharmacological way to raise endogenous growth hormone output rather than supplying the hormone directly.
After injection, the peptide binds receptors on somatotroph cells in the anterior pituitary. Receptor activation raises intracellular cyclic AMP and triggers release of stored growth hormone into the bloodstream. Because the compound works through the body's own regulatory system, growth hormone pulses retain much of their normal feedback control. Repeated administration also raises insulin-like growth factor 1, a hormone produced mainly in the liver. Investigators treat that rise as a marker that the pituitary axis has been engaged.
Several related peptides act on the same receptor, including sermorelin, a shorter GHRH fragment, and modified analogs such as CJC-1295 and modified GRF(1-29) that are common in research settings rather than approved products. Tesamorelin differs from growth hormone itself in that it acts upstream, prompting the pituitary to release the hormone through physiological signaling rather than supplying it directly. Terminology in the literature distinguishes GHRH analogs, growth hormone secretagogues, and recombinant growth hormone, although popular discussion often blurs these categories together. Precise naming matters when comparing study results.
Tesamorelin is a synthetic peptide of 44 amino acids that reproduces the sequence of human growth hormone-releasing hormone (GHRH) and carries a trans-3-hexenoyl group on its N-terminal tyrosine. That small fatty-acid modification blocks cleavage by dipeptidyl peptidase-4, the enzyme that rapidly degrades native GHRH in plasma. The result is a molecule with a longer circulating half-life than the natural hormone while retaining the same receptor target. It is supplied as a lyophilized powder for reconstitution and belongs to the broader class of GHRH analogs studied for effects on pituitary growth hormone secretion.
=== Particles and bacteria === Particles in UPW can cause defects in semiconductors, especially in photolithographic processes that define nanometer-sized features. Particulates can interfere with etching processes and bridge nanometer-scale features in final circuits causing electrical failures. Particles can be controlled by filtration for larger particles and ultrafiltration for nanometer scale particles. Particle sources can include bacterial fragments or particles from the walls of the fluid handling system. Bacteria have been referred to as one of the most obstinate on this list to control as certain bacteria can still grow, even in low-nutrient environments. Bacteria can be controlled by sanitization or ultrafiltration (found in some pharmaceutical, but mostly semiconductor industries). Chemical sanitization can be performed using ozone or hydrogen peroxide.
== Overview == The process that converts the chemical energy of food into ATP (which can release energy) is not dependent on oxygen availability. During exercise, the supply and demand of oxygen available to muscle cells is affected by duration and intensity and by the individual's cardio respiratory fitness level. It is also affected by the type of activity, for instance, during isometric activity the contracted muscles restricts blood flow (leaving oxygen and blood borne fuels unable to be delivered to muscle cells adequately for oxidative phosphorylation). Three systems can be selectively recruited, depending on the amount of oxygen available, as part of the cellular respiration process to generate ATP for the muscles. They are ATP, the anaerobic system and the aerobic system.
=== qEV columns === Size exclusion chromatography-based qEV columns contain porous polysaccharide resins, which enable extracellular vesicles to be isolated in preparation for a range of downstream analytical methods. The range of qEV columns facilitate the separation of particles in the ranges of 35-350 and 70-1000 nm and accommodate sample loading volumes between ≤150 μL and 100 mL. The manual and time-consuming work previously associated with SEC is reduced by the qEV Automatic Fraction Collector (AFC). The AFC utilizes a rotational carousel for holding collection tubes and has an in-built computer that can be programmed to automate the void volume and purified collection volume. During sample collection, the carousel detects the weight of each purified collection volume and automatically advances to the next collection tube.
Sources: en.wikipedia.org
Lactic acid bacteria are fastidious organisms that cannot synthesize on their own all of their complex nutritional requirements. For LAB to grow and complete malolactic fermentation, the constitution of the wine medium must provide for their nutritional needs. Like wine yeast, LAB require a carbon source for energy metabolism (usually sugar and malic acid), nitrogen source (such as amino acids and purines) for protein synthesis, and various vitamins (such as niacin, riboflavin, and thiamine) and minerals to assist in the synthesis of enzymes and other cellular components. The source for these nutrients is often found in the grape must itself, though MLF inoculations that run concurrent with alcoholic fermentation risk the yeast outcompeting the bacteria for these nutrients. Towards the end of fermentation, while most of the original grape must resources have been consumed, the lysis of dead yeast cells (the "lees") can be a source for some nutrients, particularly amino acids. Plus, even "dry" wines that have been fermented to dryness still have unfermentable pentose sugars (such as arabinose, ribose and xylose) left behind that can be used by both positive and spoilage bacteria. As with wine yeast, manufacturers of cultured LAB inoculum usually offer specially prepared nutritional additives that be used as a supplement. However, unlike wine yeast, lactic acid bacteria can not use the supplement diammonium phosphate as a nitrogen source.
When the foreign insulin binds with the antibodies, it does cannot work as intended. Insulin-dependent diabetes mellitus (IDDM) An out-of-date term for Type 1 diabetes mellitus. See: Type 1 diabetes mellitus. Insulin-induced atrophy Small dents that form on the skin when a person keeps injecting a needle in the same spot. They are harmless. See also: Lipoatrophy; injection site rotation. Insulin-induced hypertrophy Small lumps that form under the skin when a person keeps injecting a needle in the same spot. See also: Lipodystrophy; injection site rotation. Insulin pen An insulin injection device the size of a pen that includes a needle attached to a vial of insulin. It can be used instead of syringes for giving insulin injections. Insulin pump a device which provides a steady (or intermittent, depending on design and adjustments) infusion of insulin. Pumps can be implantable (see implantable insulin pump) or external. the latter use a subcutaneous catheter. Insulin reaction Too low a level of blood glucose (i.e., 'sugar') in the blood; also called hypoglycemia. This occurs when a person with diabetes has injected too much insulin, eaten too little food, or exercised without compensating for the increased glucose uptake caused by exercise. The person may feel hungry, nauseated, weak, nervous, shaky, confused, and sweaty. Eating small amounts of glucose converting sugar or starch (glucose, sucrose (1/2 glucose) or starch (all glucose)), sweet juice with glucose or sucrose, or food with such sugar will usually help the person feel better within 10–15 minutes.
=== Radiological hazards === Available evidence suggests that the radiation risk is small relative to the chemical hazard. The primary radiation from pure depleted uranium is due to alpha particles, which do not travel far through air and do not penetrate clothing and skin. However, as uranium-238 decays into its daughter nuclei from its decay series, pure depleted uranium will generate thorium-234 (half-life of ~24 days) followed by protactinium-234 (half life of ~7 hours), which emit more penetrating beta particles at almost the same rate as the uranium emits alpha particles. Total activity then settles to a plateau as the more stable isotope uranium-234 accumulates. A quasi-steady state of roughly 3 times the initial activity is reached within months. Once an equilibrium level of uranium-234 (and its 11 shorter-lived daughter nuclei) has built up after about a million years there will be another radiation plateau at about 14 times the initial activity, finally reaching levels comparable to natural uranium. According to the World Health Organization, radiation dose from DU would be about 60% of that from purified natural uranium with the same mass; the radiological dangers are lower due to its longer half-life and the removal of the more radioactive isotopes. Surveying the veteran-related evidence pertaining to the Gulf War, a 2001 editorial in the BMJ concluded that it was not possible to justify claims of radiation-induced lung cancer and leukaemia in veterans of that conflict.
Sources: en.wikipedia.org
Rhodiola rosea (commonly golden root, rose root, roseroot, Aaron's rod, Arctic root, king's crown, lignum rhodium, orpin rose) is a perennial flowering plant in the family Crassulaceae. It grows naturally in wild Arctic regions of Europe (including Britain), Asia, and North America (New Brunswick, Newfoundland and Labrador, Nova Scotia, Quebec; Alaska, Maine, New York, North Carolina, Pennsylvania, Vermont), and can be propagated as a groundcover. Although Rhodiola rosea has been used in traditional medicine, there is no high-quality clinical evidence of its effectiveness to treat any disease. The United States Food and Drug Administration has issued several warnings to manufacturers of R. rosea based dietary supplements for making false health claims about safety and efficacy. The plant is threatened in many countries due to rapidly growing demand. R. rosea has been identified by various farmers and researchers as a potential cash crop naturally suited for cultivation in Arctic climates. Supply comes mostly from wild harvesting on an industrial scale, and a combination of growing scarcity and a lack of regulation has led to environmental degradation, substitution or adulteration in the market, and illegal harvesting in protected areas.
With oral administration, progesterone accounts for less than 20% of the dose in circulation while 5α- and 5β-reduced products like allopregnanolone and pregnanolone account for around 80%. With vaginal administration, progesterone accounts for around 50% of the dose and 5α- and 5β-reduced metabolites for around 40%. A small amount of progesterone is converted by 21-hydroxylase into 11-deoxycorticosterone. Increases in levels of 11-deoxycorticosterone are markedly higher when progesterone is given orally as opposed to via parenteral routes like vaginal or intramuscular injection. The conversion of progesterone into 11-deoxycorticosterone occurs in the intestines (specifically the duodenum) and in the kidneys. 21-Hydroxylase appears to be absent in the liver, so conversion of progesterone into 11-deoxycorticosterone is thought not to occur in this part of the body. Endogenous progesterone is metabolized approximately 50% into 5α-dihydroprogesterone in the corpus luteum, 35% into 3β-dihydroprogesterone in the liver, and 10% into 20α-dihydroprogesterone. Metabolites of progesterone with one or more available hydroxyl groups are conjugated via glucuronidation and/or sulfation and excreted. The biological half-life of progesterone in the circulation is very short; with intravenous injection, its half-life has ranged widely from 3 to 90 minutes in various studies. The metabolic clearance rate of progesterone ranges between 2,100 and 2,800 L/day, and is constant across the menstrual cycle.
, is the probability, after time t, that there is a base j at a given position, conditional on there being a base i in that position at time 0. When the model is time reversible, this can be performed between any two sequences, even if one is not the ancestor of the other, if you know the total branch length between them. The asymptotic properties of Pij(t) are such that Pij(0) = δij, where δij is the Kronecker delta function. That is, there is no change in base composition between a sequence and itself. At the other extreme,
1. Information gathered at the beginning of a study from which variations found in the study are measured. 2. A known value or quantity with which an unknown is compared when measured or assessed. 3. The initial time point in a clinical trial, just before a participant starts to receive the experimental treatment which is being tested. At this reference point, measurable values such as CD4 count are recorded. Safety and efficacy of a drug are often determined by monitoring changes from the baseline values. (NLM) An initial measurement that is taken at an early time point to represent a beginning condition, and is used for comparison over time to look for changes. For example, the size of a tumor will be measured before treatment (baseline) and then afterwards to see if the treatment had an effect. (NCI) Bayesian approaches
Sources: en.wikipedia.org
It is a synthetic peptide analog of human growth hormone-releasing hormone. It is used clinically to reduce excess visceral abdominal fat in adults with HIV-associated lipodystrophy. It works by stimulating pituitary growth hormone release.
Pivotal trials enrolled adults with HIV and excess visceral abdominal fat, often in the context of antiretroviral therapy. Participants were assessed mainly by computed tomography for visceral adipose tissue. The approved indication remains specific to that population.
Long-term effects on cardiovascular events, mortality, and sustained fat distribution are not well established. Most trials measured changes over months rather than years. Open questions also include whether benefits persist after treatment stops.
It mirrors the 44-residue form of human growth hormone-releasing hormone. A hexenoyl group on the N-terminal tyrosine distinguishes it from the unmodified hormone. The change is intended to improve resistance to enzymatic breakdown.