This is a working overview of Insulin-like growth factor 1, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-09-29 and is reviewed periodically as new material appears.
Whether the drug improves hard clinical outcomes is not settled. No completed trial has shown a reduction in heart attacks or strokes among treated patients, although a dedicated cardiovascular outcomes study has been discussed in the literature. Investigators have also examined hepatic fat in people with HIV and fatty liver disease, cognitive measures in small cohorts, and changes in bone density. Regulatory labeling emphasizes monitoring of insulin-like growth factor 1 because supraphysiologic levels raise questions about tissue growth, and the clinical significance of that signal remains an open question rather than a demonstrated harm.
Binding of tesamorelin to the growth hormone-releasing hormone receptor on anterior pituitary somatotrophs activates a Gs protein pathway, raises cyclic AMP, and triggers release of stored growth hormone into the bloodstream. Because the analogue resists dipeptidyl peptidase-4, its plasma residence time exceeds that of native GHRH, producing a larger and more sustained secretory signal. The released growth hormone then acts on the liver and peripheral tissues to raise insulin-like growth factor 1, which feeds back on the hypothalamus and pituitary. This axis explains both the intended effects on fat distribution and the biological markers used to track them.
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.
Tesamorelin is a synthetic peptide analog of growth hormone-releasing hormone, built from 44 amino acids. Its sequence follows the natural human GHRH(1-44) backbone, with a trans-3-hexenoyl group attached to the N-terminal tyrosine. This modification blocks recognition by dipeptidyl peptidase IV, the enzyme that rapidly truncates the native hormone in circulation. The result is a molecule with a substantially longer plasma residence time than unmodified GHRH, which makes it practical for clinical and laboratory study.
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.
| Property | Value | Notes |
|---|---|---|
| Appearance | White to off-white powder | Lyophilized cake in single-use vials |
| Solubility class | Freely soluble in water | Reconstituted with sterile diluent before injection |
| Typical storage temperature | 2 to 8 degrees Celsius | Before reconstitution; protect from light |
| Typical analytical method | Reversed-phase high-performance liquid chromatography | Purity and related-substance testing |
| Identity confirmation | Mass spectrometry | Observed mass near 5.1 kDa for the intact peptide |
Pharmacodynamic studies show that tesamorelin reduces visceral adipose tissue more than subcutaneous adipose tissue in the studied population. This selectivity may relate to differences in blood flow and hormone sensitivity between fat depots. Effects on glucose metabolism and insulin sensitivity have been investigated, with some trials reporting modest changes and others showing stability. The precise relationship between growth hormone exposure, IGF-1 levels, and visceral fat loss remains an active area of analysis.
Tesamorelin binds to growth hormone-releasing hormone receptors on somatotroph cells in the anterior pituitary. Receptor activation increases intracellular cyclic AMP and promotes synthesis and secretion of growth hormone. Because the peptide mimics endogenous GHRH, it amplifies the normal pulsatile release of growth hormone rather than providing exogenous growth hormone directly. This upstream action distinguishes tesamorelin from recombinant growth hormone preparations and from growth hormone secretagogues that act at different receptors.
Stimulated growth hormone release leads to hepatic production of insulin-like growth factor 1, a key mediator of many growth hormone effects. In clinical studies, tesamorelin increased IGF-1 levels in a dose-dependent manner, although the response varies among individuals. The drug's effect on visceral fat is thought to involve growth hormone-mediated lipolysis and altered adipocyte metabolism. Muscle mass and lean body mass have also been assessed as secondary outcomes, but changes are generally smaller and less consistent than fat reductions.
Signaling begins at the GHRH receptor, a class B G protein-coupled receptor displayed on somatotroph cells of the anterior pituitary. Receptor occupancy activates Gs proteins, which raise adenylyl cyclase activity and intracellular cyclic AMP, in turn driving protein kinase A dependent pathways. The downstream output is synthesis and pulsatile secretion of growth hormone into the bloodstream. Hepatic tissue and peripheral sites respond by increasing insulin-like growth factor 1 production. Somatostatin and IGF-1 itself supply negative feedback that caps the size and duration of each secretory burst.
Metabolic interest in this compound centers on fat distribution rather than on hormone levels alone. Imaging trials in adults with excess abdominal fat report reductions in visceral adipose tissue, while subcutaneous depots change comparatively little. Growth hormone and IGF-1 are presumed to carry the effect, but the separate contribution of each is not firmly established. Whether these changes persist after treatment stops, and whether they alter longer-term health outcomes, remain open questions that published work does not answer consistently.
Tesamorelin is a synthetic peptide of forty-four amino acids whose sequence reproduces human growth hormone-releasing hormone. Its distinguishing feature sits at the amino terminus, where a trans-3-hexenoyl group replaces the free amine. That acylation slows cleavage by dipeptidyl peptidase IV, an enzyme that otherwise removes the first two residues and inactivates the natural hormone quickly. The modified peptide therefore persists longer in circulation while keeping the same receptor target. It is handled as a lyophilized solid and dissolved shortly before use.
质量控制项目一般包括外观、身份、纯度、含量、有关物质、水分和微生物限度。身份确认可通过肽图谱、氨基酸分析和质谱完成，纯度则用面积归一化法计算。研究级材料与药品级材料的要求不同，前者常缺少完整药典验证。不同批次间杂质谱是否影响活性，仍是一个需要具体数据回答的问题。
特沙莫瑞林的检测通常依赖反相高效液相色谱和质谱联用。反相色谱可分离肽主峰与缺失序列、氧化产物等杂质，质谱则提供精确质量以确认身份。对于复杂基质中的定量，常采用液相色谱-串联质谱，并配合固相萃取或蛋白沉淀。生物样品中的肽易降解，因此采集和处理条件会影响结果。
Dubnium is a synthetic chemical element; it has symbol Db and atomic number 105. It is highly radioactive: the most stable known isotope, dubnium-268, has a half-life of about 16 hours. This greatly limits extended research on the element. Dubnium does not occur naturally on Earth and is produced artificially. The Soviet Joint Institute for Nuclear Research (JINR) claimed the first discovery of the element in 1968, followed by the American Lawrence Berkeley Laboratory in 1970. Both teams proposed their names for the new element and used them without formal approval. The long-standing dispute was resolved in 1993 by an official investigation of the discovery claims by the Transfermium Working Group, formed by the International Union of Pure and Applied Chemistry and the International Union of Pure and Applied Physics, resulting in credit for the discovery being officially shared between both teams. The element was formally named dubnium in 1997 after the town of Dubna, the site of the JINR. Theoretical research establishes dubnium as a member of group 5 in the 6d series of transition metals, placing it under vanadium, niobium, and tantalum. Dubnium should share most properties, such as its valence electron configuration and having a dominant +5 oxidation state, with the other group 5 elements, with a few anomalies due to relativistic effects. A limited investigation of dubnium chemistry has confirmed this.
Certain mutations in rRNA that were able to trigger rRNA degradation in eukaryotes were unable to do so in prokaryotes. Point mutations in a 23S rRNA would cause both 23S and 16S rRNAs to be degraded, in comparison to eukaryotes, in which mutations in one subunit would only cause that subunit to be degraded. Researchers found that removal of a whole helix structure (H69) from the 23S rRNA did not trigger its degradation. This led them to believe that H69 was critical for endonucleases to recognize and degrade the mutated rRNA.
Ultraviolet light detectors, fixed or variable wavelength, which includes diode array detectors. The ultraviolet light absorption of the effluent is continuously measured at single or multiple wavelengths. These are by far most popular detectors for liquid chromatography. Fluorescence detector. Irradiates the effluent with a light of set wavelength and measure the fluorescence of the effluent at a single or multiple wavelength. Refractive index detector. Continuously measures the refractive index of the effluent. The lowest sensitivity of all detectors. Often used in size exclusion chromatography for polymer analysis. Radio flow detector. Measures radioactivity of the effluent. This detector can be destructive if a scintillation cocktail is continuously added to the effluent. Chiral detector continuously measures the optical angle of rotation of the effluent. It is used only when chiral compounds are being analyzed. Conductivity monitor. Continuously measures the conductivity of the effluent. Used only when conductive eluents (water or alcohols) are used. Non-destructive detectors in gas chromatography:
Drugs administered through topical application can act locally or systemically. However, the drug molecules must first be retained in and penetrate the surface layer of the skin. Absorption of the drug through the skin surface is a passive process of diffusion. Skin penetration of the drug can take place by passive diffusion directly through the epidermis (via transcellular or intercellular routes), or absorption through shunt routes (diffusion through hair follicles and sweat glands). Initially, drug absorption may take place via the transfolliar route. After the drug reaches a steady state, transepidermal absorption may replace transfolliar absorption as the main pathway for absorption. Drug absorption through the skin varies depending on the concentration gradient between the surface of the skin and the body, with a higher rate of absorption resulting from a greater concentration gradient. The rate of drug absorption can be maintained at a constant level by ensuring that the drug concentration at the surface of the skin remains consistently and substantially greater than that in the body. The rate of penetration of the drug across the skin barrier depends on the physiological factors, physicochemical properties of the drug, and gel characteristics. Physiological factors include skin properties, size of application area, frequency and force of application. Physicochemical properties of the drug include drug solubility, affinity for the skin, and metabolism. Gel characteristics include stability, thermodynamic activity, and occlusive properties.
Necrophages (also known as carrion feeders) are animals that feed on decomposing dead animal biomass, such as the muscle and soft tissue of carcasses or corpses. The term derives from Greek nekros, meaning 'dead', and phagein, meaning 'to eat'. Many hundreds of necrophagous species have been identified including invertebrates in the insect, malacostracan and gastropod classes and vertebrates such as vultures, hyenas, quolls and wolves. Necrophagous insects are important in forensic science as the presence of some species (e.g. Calliphora vomitoria) in a body, coupled with information on their development stage (e.g. egg, larva, pupa), can yield information on time of death. Information on the insect species present can also be used as evidence that a body has been moved, and analysis of insect tissue can be used as evidence that drugs or other substances were in the body. Necrophages are useful for other purposes too. In healthcare, green bottle fly larvae are sometimes used to remove necrotic (dead) tissue from non-healing wounds, and in waste management, black soldier fly larvae are used to convert decomposing organic waste into animal feed. Biotechnological applications for necrophage-derived genes, molecules and microbes are also being explored.
Sources: en.wikipedia.org
== External links == DASH7 Alliance Low Power Wide Area Network Technology Comparison OSS-7 Open Source Stack Archived 2019-12-24 at the Wayback Machine OpenTag wiki Archived 2019-12-06 at the Wayback Machine DASH7-LoRaWAN Comparison
Aspergillus luchuensis was first described in 1901 by Tamaki Inui at the University of Tokyo. Genichiro Kawachi isolated a colourless mutant of A. luchuensis (black kōji) in 1918 and named it Aspergillus kawachii (white kōji). Aspergillus sojae was first described as a distinct species in kōji in 1944. Initially, Aspergillus sojae was considered a variety of Aspergillus parasiticus because, unlike the other fungi of kōji, it had never been isolated from the soil.
First Reverse Aging Trial in Humans ° The biopharmeceutical company Life Biosciences, founded by David A. Sinclair, announced the start of a phase 1 clinical trial for ER-100, a novel therapy intended to reverse age-related vision loss via the activation of three genes in retinal ganglion cells, marking the first time a cellular reprogramming therapy was given to humans.
===== Vildagliptin ===== Vildagliptin (Galvus)(Figure 6) was first synthesized in May 1998 and was named after Edwin B. Villhauer. It was discovered when researchers at Novartis examined adamantyl derivatives that had proven to be very potent. The adamantyl group worked as a steric bulk and slowed intramolecular cyclization while increasing chemical stability. Furthermore, the primary metabolites were highly active. To avoid additional chiral center a hydroxylation at the adamantyl ring was carried out (Figure 6). The product, vildagliptin, was even more stable, undergoing intramolecular cyclization 30-times slower, and having high DPP-4 inhibitory activity and longer-lasting pharmacodynamic effect.
For a high score, or pretest probability, a D-dimer will make little difference and anticoagulant therapy will be initiated regardless of test results, and additional testing for DVT or pulmonary embolism may be performed. For a moderate or low score, or pretest probability: A negative D-dimer test will virtually rule out thromboembolism: the degree to which the D-dimer reduces the probability of thrombotic disease is dependent on the test properties of the specific test used in the clinical setting: most available D-dimer tests with a negative result will reduce the probability of thromboembolic disease to less than 1% if the pretest probability is less than 15-20%. Chest computed tomography (CT angiography) should not be used to evaluate pulmonary embolism for persons with negative results of a D-dimer assay. A low pretest probability is also valuable in ruling out PE. If the D-dimer reads high, then further testing (ultrasound of the leg veins or lung scintigraphy or CT scanning) is required to confirm the presence of thrombus. Anticoagulant therapy may be started at this point or withheld until further tests confirm the diagnosis, depending on the clinical situation. In some hospitals, they are measured by laboratories after a form is completed showing the probability score and only if the probability score is low or intermediate. This reduces the need for unnecessary tests in those who are high-probability. Performing the D-dimer test first can avoid a significant proportion of imaging tests and is less invasive.
Sources: en.wikipedia.org
In lichenology, where many genera are small (the average genus has approximately 19 species, and a quarter of genera are monospecific), changes at genus level can particularly cause fragmentation. Discussions continue on how best to balance the need for monophyletic groups with the practical need for taxa that are reasonably diagnosable and useful. Nimis's five‑point checklist, although written for generic splits, provided an early blueprint for balancing lineage evidence with the practical need for taxonomic stability. Emerging technologies offer new tools for lichen systematics. Long-read sequencing is making it feasible to assemble complete genomes of lichen fungi and their photobionts, providing extensive character data and resolving complex structural variants. Environmental metagenomics can detect lichen DNA in soil and air samples, potentially allowing surveys of overlooked microlichen diversity. Machine learning models show promise for identifying lichens from photographs and detecting patterns in multidimensional datasets. However, these technologies require robust reference databases and high-quality baseline taxonomy to be effective. As Lücking (2020) notes, incomplete or flawed taxonomy will simply be perpetuated more rapidly by automated systems. The principle of the "minimum adequate method" remains relevant—traditional methods like culture experiments and careful morphological observation continue to answer questions that sequencing alone cannot.
=== Other compounds === Francium nitrate, sulfate, hydroxide, carbonate, acetate, and oxalate, are all soluble in water, while the iodate, picrate, tartrate, chloroplatinate, and silicotungstate are insoluble. The insolubility of these compounds are used to extract francium from other radioactive products, such as zirconium, niobium, molybdenum, tin, antimony, the method mentioned in the section above. Francium oxide is believed to disproportionate to the peroxide and francium metal. The CsFr molecule is predicted to have the heavier element (francium) at the negative end of the dipole, unlike all known heterodiatomic alkali metal molecules. Francium superoxide (FrO2) is expected to have a more covalent character than its lighter congeners; this is attributed to the 6p electrons in francium being more involved in the francium–oxygen bonding. The relativistic destabilisation of the 6p3/2 spinor may make francium compounds in oxidation states higher than +1 possible, such as [FrVF6]−; but this has not been experimentally confirmed.
Orforglipron — brand name Foundayo — is an oral, non-peptide, small-molecule GLP-1 receptor agonist developed as a weight loss drug by Eli Lilly and Company. It was discovered by Chugai Pharmaceutical Co., then was licensed to Lilly in 2018. Orforglipron was approved for medical use in the United States in April 2026. It was approved for use in the UK in August 2026.
The People's Armed Police Forestry Corps (Chinese: 武警森林部队) was a former branch of the PAP which did tasks such as fighting Wildfires and law enforcement in forest areas, along with protecting wildlife, disaster relief. When it was active, it was the only military branch on Earth whose task was fighting wildfires. It was nicknamed the "Fearless Red Boys". The Forestry Corps was officially disbanded on 10 October 2018.
Sources: en.wikipedia.org
It mimics a natural hypothalamic signal that tells the pituitary to release growth hormone. The result is a rise in circulating growth hormone and, indirectly, in insulin-like growth factor 1. Over weeks of treatment this shift is associated with a selective decrease in fat stored inside the abdomen.
The primary measure is usually a cross-sectional abdominal scan that separates internal fat from fat just under the skin. Waist circumference and body weight are recorded as secondary measures because they are easy to obtain but do not distinguish the two fat compartments. Hormone and metabolic blood tests are collected alongside the imaging.
Available follow-up data indicate that visceral fat drifts back toward pretreatment levels once injections stop. The change is therefore best described as treatment-dependent rather than permanent. Investigators continue to debate whether intermittent or repeated courses would preserve any benefit.
The principal difference is a chemical cap on the N-terminal tyrosine that prevents rapid enzymatic cleavage. Native GHRH is degraded within minutes in plasma, whereas the modified peptide persists considerably longer. The amino acid backbone otherwise mirrors the natural hormone.