The short version of reversed-phase HPLC fits in a sentence. The long version — which is the one that helps — is below.
Reviewed 2025-12-31. Anything still debated is marked as such rather than presented as settled.
Tesamorelin is a synthetic peptide that belongs to the growth hormone-releasing hormone family and contains the same forty-four amino acid sequence as endogenous GHRH, extended at the amino terminus by a trans-3-hexenoyl group. That small fatty acid modification protects the peptide from rapid cleavage by dipeptidyl peptidase-4, the enzyme that shortens the half-life of native GHRH to only a few minutes. Chemically the compound is produced by solid-phase peptide synthesis, purified by chromatography, and supplied as a sterile lyophilized powder for reconstitution.
Regulatory approval in the United States came in 2010, when the Food and Drug Administration cleared the peptide for the reduction of excess abdominal fat in adults with HIV infection and associated lipodystrophy. The decision rested mainly on two randomized phase 3 trials that enrolled roughly eight hundred patients and ran for twenty-six weeks. Participants receiving active drug showed substantially greater declines in visceral adipose tissue than those receiving placebo, while total body weight changed comparatively little. A reformulated presentation was later approved, and the product has remained a niche therapy rather than a general weight-loss agent.
Identity and purity are judged through a combination of chromatographic and mass spectrometric techniques. Reversed-phase high-performance liquid chromatography separates the intact peptide from truncated, oxidized, and deamidated variants, and the resulting peak-area percentages yield a purity figure. Electrospray ionization mass spectrometry confirms the expected molecular mass and can expose unanticipated modifications. Amino acid analysis and peptide mapping support sequence fidelity, while water content, pH, sterility, and bacterial endotoxin testing describe the physical and microbiological attributes of a finished lot.
Regulatory position depends on jurisdiction and on the form in which the material is sold. A branded product holds approval in the United States for a defined indication, and prescribing is confined to that label. Material marketed for laboratory research is not evaluated for human use and carries no such clearance. Independent verification therefore rests on certificates of analysis, third-party testing, and documented chain of custody. The substance also appears on the World Anti-Doping Agency prohibited list within the category covering growth hormone-releasing factors.
| Property | Value | Notes |
|---|---|---|
| Peptide class | Synthetic GHRH analogue | 44 residues; N-terminal trans-3-hexenoyl group |
| First approval year | 2010 | United States; HIV-associated abdominal fat accumulation |
| Administration route | Subcutaneous injection | Abdominal site; clinician-administered or self-injected |
| Common synonyms | TH9507; tesamorelin acetate | Development code and acetate salt form |
| Originator | Canadian biotechnology firm | Original developer and regulatory sponsor |
研究背景集中在特定人群的体成分改变，尤其是与脂肪分布异常相关的内脏脂肪堆积。不同地区对它的监管状态与获批适应症并不一致，部分市场仅限特定诊断人群使用。在一般人群中的长期效应、与其他激素的相互作用以及停药后的维持情况仍属开放问题，现有数据不足以给出普遍结论。
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。
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.
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.
=== Serotypes === H. influenzae isolates were initially characterized as either encapsulated (having an extracellular polysaccharide layer, the bacterial capsule) or unencapsulated. Encapsulated strains were further classified on the basis of the immune response to the type of polysaccharides in their capsule. The six generally recognized types of encapsulated H. influenzae are: a, b, c, d, e, and f. H. Influenzae type b, also known as Hib, is the most common form, recognizable by its polyribosyl ribitol phosphate (PRP) capsule, and found mostly in children. Types a, e, and f have been isolated infrequently, while types d and c are rarely isolated. Unencapsulated strains are more genetically diverse than the encapsulated group. Unencapsulated strains are termed nontypable (NTHi) because they lack capsular serotypes; however, all H. influenzae isolates can now be classified by multilocus sequence typing and other molecular methods. Most NTHi strains are considered to be part of the normal human flora in the upper and lower respiratory tract, genitals, and conjunctivae (mucous membranes of the eye).
Type I – originates in ascending aorta, and propagates at least to the aortic arch and often beyond it distally. It is most often seen in patients less than 65 years of age and is the most lethal form of the disease. Type II – originates in the ascending aorta and is confined to it. Type III – originates in the descending aorta and rarely extends proximally, but will extend distally. It most often occurs in elderly patients with atherosclerosis and hypertension.
Voltage-gated ion channels are capable of producing action potentials because they can give rise to positive feedback loops: the membrane potential controls the state of the ion channels, and the state of the ion channels controls the membrane potential. Thus, in some situations, a rise in the membrane potential can cause ion channels to open, thereby causing a further rise in the membrane potential. An action potential occurs when this positive feedback cycle proceeds explosively. The time and amplitude trajectory of the action potential are determined by the biophysical properties of the voltage-gated ion channels that produce it. Several types of channels capable of producing the positive feedback necessary to generate an action potential do exist. Voltage-gated sodium channels are responsible for the fast action potentials involved in nerve conduction. Slower action potentials in muscle cells and some types of neurons are generated by voltage-gated calcium channels. Each of these types comes in multiple variants, with different voltage sensitivity and different temporal dynamics. The most intensively studied type of voltage-dependent ion channels comprises the sodium channels involved in fast nerve conduction. These are sometimes known as Hodgkin-Huxley sodium channels because they were first characterized by Alan Hodgkin and Andrew Huxley in their Nobel Prize-winning studies of the biophysics of the action potential, but can more conveniently be referred to as NaV channels.
In 2020, Chen Xiaojiang was appointed as head of the National Ethnic Affairs Commission, the first Han Chinese head of the body since 1954. On 24 June 2022, Pan Yue, another Han Chinese, became the head of the commission, with him reportedly holding assimilationist policies toward ethnic minorities. Xi outlined his official views relations between the majority Han Chinese and ethnic minorities by saying "[n]either Han chauvinism nor local ethnic chauvinism is conducive to the development of a community for the Chinese nation." Xi's policies toward ethnic minorities were codified in the Law on Promoting Ethnic Unity and Progress in 2026.
Sources: en.wikipedia.org
Glycopeptides are peptides that contain carbohydrate moieties (glycans) covalently attached to the side chains of the amino acid residues that constitute the peptide. Over the past few decades it has been recognised that glycans on cell surface (attached to membrane proteins or lipids) and those bound to proteins (glycoproteins) play a critical role in biology. For example, these constructs have been shown to play important roles in fertilization, the immune system, brain development, the endocrine system, and inflammation. The synthesis of glycopeptides provides biological probes for researchers to elucidate glycan function in nature and products that have useful therapeutic and biotechnological applications.
=== Pharmacogenetics === Since amitriptyline is primarily metabolized by CYP2D6 and CYP2C19, genetic variations within the genes coding for these enzymes can affect its metabolism, leading to changes in the concentrations of the drug in the body. Increased concentrations of amitriptyline may increase the risk for side effects, including anticholinergic and nervous system adverse effects, while decreased concentrations may reduce the drug's efficacy. Individuals can be categorized into different types of CYP2D6 or CYP2C19 metabolizers depending on which genetic variations they carry. These metabolizer types include poor, intermediate, extensive, and ultrarapid metabolizers. Most individuals (about 77–92%) are extensive metabolizers, and have "normal" metabolism of amitriptyline. Poor and intermediate metabolizers have reduced metabolism of the drug as compared to extensive metabolizers; patients with these metabolizer types may have an increased probability of experiencing side effects. Ultrarapid metabolizers use amitriptyline much faster than extensive metabolizers; patients with this metabolizer type may have a greater chance of experiencing pharmacological failure. The Clinical Pharmacogenetics Implementation Consortium recommends avoiding amitriptyline in patients who are CYP2D6 ultrarapid or poor metabolizers, due to the risk of a lack of efficacy and side effects, respectively. The consortium also recommends considering an alternative drug not metabolized by CYP2C19 in patients who are CYP2C19 ultrarapid metabolizers.
== Medical uses == In the United States, gemtuzumab ozogamicin is indicated for newly diagnosed CD33-positive acute myeloid leukemia (AML) for adults and children one month and older and for the treatment of relapsed or refractory CD33-positive AML in adults and children two years and older.
Kato K, Kawahara K, Takahashi T, Kakinuma A (1980). "Purification of an α-amino acid ester hydrolase from Xanthomonas citri". Agric. Biol. Chem. 44: 1069–1074. doi:10.1271/bbb1961.44.1069. Kato K, Kawahara K, Takahashi T, Kakinuma A (1980). "Substrate specificity of an α-amino acid ester hydrolase from Xanthomonas citri". Agric. Biol. Chem. 44: 1075–1081. doi:10.1271/bbb1961.44.1075. Takahashi T, Yamazaki Y, Kato K (1974). "Substrate specificity of an α-amino acid ester hydrolase produced by Acetobacter turbidans A.T.C.C. 9325". Biochem. J. 137 (3): 497–503. doi:10.1042/bj1370497. PMC 1166149. PMID 4424889.
Most of its chemistry is nonmetallic; it has a relatively high ionization energy and, compared to most metals, a relatively high electronegativity. Carbon can form anions such as C4− (methanide), C2–2 (acetylide), and C3–4 (sesquicarbide or allylenide), in compounds with metals of main groups 1–3, and with the lanthanides and actinides. Its oxide CO2 forms carbonic acid H2CO3.
Sources: en.wikipedia.org
In 1981, a commercial involving a train was made, the musical theme was "La Colegiala" composed by Rodolfo Aicardi. Due to the enormous popularity of Nescafé, during the Second World War, "all the production of the American plant was reserved only for the use of the military". In Ecuador, a Boeing 737-200 from the AeroGal company was painted red to promote the brand. In Chile, since 2009 the brand has sponsored and helped to restore a well-known Chilean theater that was in decline, making it the first Nescafé theater in the world and naming it the Nescafé Theater of the Arts. In previous years, the brand was sponsoring different stars of Canal 13, such as Esta Noche Fiesta and Tuesday 13, the 123 Nescafé competition and was for some time the sponsor of different campaigns of the Chilean Telethon, returning as sponsor to the campaign in 2011. In turn, its variant Nescafé Dolca was sponsor of Una Vez Más of Canal 13. In the Philippines, an advertising commercial was released in 2020 with their newest jingle and slogan, "Babangon tayo, susulong tayo" ("We will rise, we will advance"). English rock band Muse successfully sued Nescafé in 2003 when their song "Feeling Good" was used in a television ad without permission and donated the £500,000 compensation to Oxfam.
The term diabetes is derived from the Ionic for 'siphon', meaning "to pass or run through". It reflects the dominant notion at the time that fluids consumed by the diabetic patient passed through the body unchanged, as if flowing through a tube or siphon. A number of conflicting accounts exist as to the first use of this term, placing the originator as either Apollonius of Memphis (fl. 3rd century BC), Demetrius of Apamea (fl. 100 BC), or Aretaeus of Cappadocia (fl. early 2nd century AD). In-depth probes of Greek etymology agree that the term came from Demetrius of Apamea, C. L. Gemmill (1972) states:Caelius Aurelianus prepared a Latin version of the works of Soranus. In the index of the Drabkin edition there is a subject heading "Diabetes," but on examination of the text this section could not be found (footnote 3, p. 776) except for a short paragraph. In this paragraph Caelius quotes Apollonius of Memphis as separating two forms of dropsy, one marked by retention of fluid and the other by the inability to retain fluid; the patient discharges whatever he drinks as if it were passed through a pipe. Apollonius lived in the second half of the third century B.C. Caelius Aurelianus continues by stating that Demetrius of Apamea distinguishes this disease from dropsy in which any fluid that is drunk is discharged as urine. Demetrius calls this condition diabetes. The time of Demetrius of Apamea is given as the first century B.C. None of his works have come down to us; we have only quotations in later authors.
Alchemists burned zinc metal in air and collected the resulting zinc oxide (ZnO) on a condenser. Some alchemists called this zinc oxide lana philosophica, Latin for "philosopher's wool", because it collected in woolly tufts, whereas others thought it looked like white snow and named it nix album. The name of the metal was probably first documented by Paracelsus, a Swiss-born German alchemist, who referred to the metal as "zincum" or "zinken" in his book Liber Mineralium II, in the 16th century. The word is probably derived from the German zinke, and supposedly meant "tooth-like, pointed or jagged" (metallic zinc crystals have a needle-like appearance). Zink could also imply "tin-like" because of its relation to German zinn meaning tin. Yet another possibility is that the word is derived from the Persian word سنگ seng meaning stone. The metal was also called Indian tin, tutanego, calamine, and spinter. German metallurgist Andreas Libavius received a quantity of what he called "calay" (from the Malay or Hindi word for tin) originating from Malabar off a cargo ship captured from the Portuguese in the year 1596. Libavius described the properties of the sample, which may have been zinc. Zinc was regularly imported to Europe from the Orient in the 17th and early 18th centuries, but was at times very expensive.
With the dissolution of the Soviet Union and the Fall of Communism, there was a split among Marxist–Leninists between those hardline Marxist–Leninists, sometimes referred to in the media as neo-Stalinists, which remained committed to orthodox Marxism–Leninism, and those democratic Marxist–Leninists which continued to work within the liberal-democratic process for a democratic road to socialism, while many other ruling Marxist–Leninist parties became closer to democratic socialist and social democratic parties. Outside Communist states, reformed Marxist–Leninist communist parties have led or been part of left-leaning coalitions, including in the former Eastern Bloc. In Nepal, Marxist–Leninists (CPN UML and Nepal Communist Party) were part of the 1st Nepalese Constituent Assembly, which abolished the monarchy in 2008 and turned the country into a federal liberal-democratic republic, and have democratically shared power with Maoists (CPN Maoist), social democrats (Nepali Congress), and others as part of their People's Multiparty Democracy.
Sources: en.wikipedia.org
It is a laboratory-made peptide of forty-four amino acids whose sequence matches human growth hormone-releasing hormone, with a modified amino terminus. The modification is a short unsaturated fatty acid chain attached to the first residue. This change slows enzymatic breakdown and lengthens the time the peptide stays active in circulation.
The clinical program was designed around HIV-associated lipodystrophy, a condition in which fat accumulates abnormally around the internal organs. Trials enrolled that specific population, so the evidence base covers it rather than the general population. Regulators approved the drug for the studied indication only, and promotion outside it is not permitted.
Growth hormone therapy supplies the finished hormone directly, while this peptide acts upstream and asks the pituitary to secrete its own. That difference means the response depends on a functioning pituitary and on the body's normal feedback loops. It also means the circulating hormone profile is pulsatile rather than a flat, injected level.
Reconstituted solutions are kept cold and used within the period stated on the label or certificate. Repeated warming and cooling cycles should be avoided because they encourage aggregation and gradual loss of potency.