This is a working overview of visceral adipose tissue, written for readers who want more than a one-paragraph summary but less than a textbook.
This page was last updated on 2025-10-21 and is reviewed periodically as new material appears.
监管记录显示,特沙莫瑞林于 2010 年在美国首次获得批准,用于人类免疫缺陷病毒感染相关的脂肪营养不良患者。批准依据来自降低内脏脂肪的临床试验,而非体重或瘦体重的普遍改善。后续出现了不同制剂版本,但其核心适应症保持一致。关于长期心血管结局和死亡率影响,现有证据仍不充分。
在临床研究之外,特沙莫瑞林常被讨论为生长激素分泌促进剂,但这一说法需要限定。它并不等同于生长激素本身,也不属于普通减重药物。部分研究关注其减少腹部脂肪和改善脂质谱的潜力,另一些研究则关注胰岛素抵抗和 IGF-1 升高等信号。这些效应的临床意义仍在评估中,尚未形成统一结论。
特沙莫瑞林是一种合成肽,其序列与人生长激素释放激素的 44 个氨基酸形式相关。它在 N 端带有反式-3-己烯酰基修饰,这一改动可减缓二肽基肽酶 IV 的降解。该化合物属于生长激素释放激素受体激动剂,可刺激垂体释放生长激素。研究文献通常将其归入合成肽类药物,而非小分子化合物。
Published work tends to frame tesamorelin as a tool for studying the GHRH axis and as a compound with measurable effects on body composition. Reports often describe visceral adipose tissue as an endpoint, assessed by imaging rather than by inference. Analytical sections commonly describe liquid chromatography with tandem mass spectrometry to confirm identity and purity, because immunoassays may cross-react with related fragments. Where results diverge between studies, differences in assay choice, sampling timing, and population are frequent explanations offered. Whether effects persist after treatment stops remains an open question.
Tesamorelin binds the growth hormone–releasing hormone receptor on pituitary somatotroph cells. The receptor signals through the Gs protein, raising intracellular cAMP and activating protein kinase A. That cascade triggers release of stored growth hormone in pulses rather than a steady stream. Because the drug acts at the receptor that normally controls this process, its effect depends on the body's own signaling architecture rather than on a synthetic pathway. The resulting hormone profile reflects the timing of each pulse, not only its size.
| Property | Value | Notes |
|---|---|---|
| 分子类型 | 合成肽 | 含 44 个氨基酸残基的 GHRH 类似物 |
| N 端修饰 | 反式-3-己烯酰基 | 用于抵抗二肽基肽酶 IV 降解 |
| 首次批准 | 2010 年,美国 | 用于 HIV 相关脂肪营养不良 |
| 作用靶点 | 生长激素释放激素受体 | 位于垂体前叶 |
| 主要研究终点 | 内脏脂肪变化 | 非总体重或瘦体重 |
Development work on the compound, originally designated TH9507, focused on conditions in which reduced growth hormone signaling is thought to contribute to altered body composition. The United States Food and Drug Administration approved it in 2010 for the treatment of excess visceral abdominal fat in adults with human immunodeficiency virus infection and lipodystrophy. Later research examined other populations, including adults with mild cognitive impairment, where a large trial did not meet its primary endpoints. This mixed record illustrates how a single mechanism can produce clear effects in one setting and inconclusive results in another.
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.
Storage claims vary across suppliers, and published stability data for specific formulations are limited. Extrapolating from related peptides is common but not a substitute for direct measurement. For research use, documentation such as a certificate of analysis is often requested to confirm identity and purity. What constitutes an acceptable purity threshold depends on the intended application. Open questions remain about how temperature excursions during shipping affect long-term peptide integrity. Independent verification by an end user is not routinely reported.
Lyophilized tesamorelin is generally stored refrigerated at 2 to 8 degrees Celsius, protected from light and moisture. Peptides in this class are often kept frozen at minus 20 degrees Celsius for longer periods. Reconstituted solutions are typically used within a defined window because hydrolysis and oxidation proceed faster in liquid form. Container material and headspace also influence how long a preparation retains its expected profile. Specific stability figures depend on concentration and buffer composition.
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.
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.
Studies of the compound rely on imaging and laboratory endpoints rather than on symptoms alone. Visceral adipose tissue is usually quantified by computed tomography or magnetic resonance imaging at the level of the abdomen, with waist circumference serving as a cheaper but less specific proxy. Blood work tracks insulin-like growth factor 1, fasting glucose, glycated hemoglobin, and lipid fractions. In the pivotal trials the imaging endpoint fell by roughly fifteen to twenty percent over six months, subcutaneous fat changed little, and the visceral fat returned toward baseline after treatment stopped, a pattern that shapes how clinicians discuss durability.
the alternation of late wood and early wood increments within the annual ring; the influence of wood rays on the radial direction; the features of the cell wall structure such as microfibril angle modifications and pits; the chemical composition of the middle lamella. Wood drying may be described as the art of ensuring that gross dimensional changes through shrinkage are confined to the drying process. Ideally, wood is dried to that equilibrium moisture content as will later (in service) be attained by the wood. Thus, further dimensional change will be kept to a minimum. It is probably impossible to completely eliminate dimensional change in wood, but elimination of change in size may be approximated by chemical modification. For example, wood can be treated with chemicals to replace the hydroxyl groups with other hydrophobic functional groups of modifying agents. Among all the existing processes, wood modification with acetic anhydride has been noted for the high anti-shrink or anti-swell efficiency (ASE) attainable without damage to wood. However, acetylation of wood has been slow to be commercialised due to the cost, corrosion and the entrapment of the acetic acid in wood. There is an extensive volume of literature relating to the chemical modification of wood. Drying timber is one method of adding value to sawn products from the primary wood processing industries.
In the 17th century Guillaume Amontons discovered a regular relationship between the pressure and temperature of a gas at constant volume. Some introductory physics textbooks still define the pressure-temperature relationship as Gay-Lussac's law. Gay-Lussac primarily investigated the relationship between volume and temperature and published it in 1802, but his work did cover some comparison between pressure and temperature. Given the relative technology available to both men, Amontons could only work with air as a gas, whereas Gay-Lussac was able to experiment with multiple types of common gases, such as oxygen, nitrogen, and hydrogen.
The different forms of MSH belong to a group called the melanocortins. This group includes ACTH, α-MSH, β-MSH, and γ-MSH; these peptides are all cleavage products of a large precursor peptide called proopiomelanocortin (POMC). α-MSH is the most important melanocortin for pigmentation. The different forms of MSH have the following amino acid sequences:
=== Ligand-based === Ligand-based drug design (or indirect drug design) relies on knowledge of other molecules that bind to the biological target of interest. These other molecules may be used to derive a pharmacophore model that defines the minimum necessary structural characteristics a molecule must possess in order to bind to the target. A model of the biological target may be built based on the knowledge of what binds to it, and this model in turn may be used to design new molecular entities that interact with the target. Alternatively, a quantitative structure-activity relationship (QSAR), in which a correlation between calculated properties of molecules and their experimentally determined biological activity, may be derived. These QSAR relationships in turn may be used to predict the activity of new analogs.
Eigen et al. and Woese proposed that the genomes of early protocells were composed of single-stranded RNA, and that individual genes corresponded to separate RNA segments, rather than being linked end-to-end as in present-day DNA genomes. A protocell that was haploid (one copy of each RNA gene) would be vulnerable to damage, since a single lesion in any RNA segment would be potentially lethal to the protocell (e.g., by blocking replication or inhibiting the function of an essential gene). Vulnerability to damage could be reduced by maintaining two or more copies of each RNA segment in each protocell, i.e., by maintaining diploidy or polyploidy. Genome redundancy would allow a damaged RNA segment to be replaced by an additional replication of its homolog. However, for such a simple organism, the proportion of available resources tied up in the genetic material would be a large fraction of the total resource budget. Under limited resource conditions, the protocell reproductive rate would likely be inversely related to ploidy number. The protocell's fitness would be reduced by the costs of redundancy. Consequently, coping with damaged RNA genes while minimizing the costs of redundancy would likely have been a fundamental problem for early protocells. A cost-benefit analysis was carried out in which the costs of maintaining redundancy were balanced against the costs of genome damage.
Sources: en.wikipedia.org
== Veterinary use == Paroxetine may be useful in the treatment of canine or feline behavioral diagnoses and is effective in the treatment of social anxiety, depression, and agitation associated with depression.
In June 2020, HHS announced an unusual agreement with Gilead in which HHS agreed to Gilead's wholesale acquisition price, HHS would continue to work together with state governments and drug wholesaler AmerisourceBergen to allocate shipments of remdesivir vials to American hospitals through the end of September 2020, and in exchange, during that three-month timeframe (July, August, and September), American patients would be allocated over 90% of Gilead's projected remdesivir output of more than 500,000 treatment courses. Absent from these announcements was any discussion of allocation of remdesivir production to the approximately 70 countries omitted from Gilead's generic drug licensing agreements—including much of Europe and countries as populous as Brazil, China, and Mexico—or the 127 countries listed on those agreements (during the time it will take for Gilead's generic licensees to ramp up their own production). As the implications of this began to sink in, several countries publicly confirmed the next day that they already had adequate supplies of remdesivir to cover current needs, including Australia, Germany, and the United Kingdom. In August 2020, the FDA broadened the Emergency Use Authorization (EUA) for remdesivir to include all hospitalized patients with suspected or laboratory-confirmed COVID‑19, irrespective of the severity of their disease. The Fact Sheet was updated to reflect the new guidance.
=== Industrial production of chemicals === The dominant use for sulfuric acid is in the "wet method" for the production of phosphoric acid, used for manufacture of phosphate fertilizers. In this method, phosphate rock is used, and more than 100 million tonnes are processed annually. This raw material is shown below as fluorapatite, though the exact composition may vary. This is treated with 93% sulfuric acid to produce calcium sulfate, hydrogen fluoride (HF) and phosphoric acid. The HF is removed as hydrofluoric acid. The overall process can be represented as:
There are also intra-country zones such as the Cactus Curtain surrounding the Guantanamo Bay Naval Base in Cuba, the Korean Demilitarised Zone along the North Korea-South Korea demarcation line and the Frontier Closed Area in Hong Kong. Important historical examples are the Wire of Death set up by the German Empire to control the Belgium–Netherlands border and the Iron Curtain, a set of border zones maintained by the Soviet Union and its satellite states along their borders with Western states. One of the most militarised parts was the restricted zone of the inner German border. While the zone was initially and officially for border security, it was eventually engineered to prevent escape from the Soviet sphere into the West. Ultimately, the Eastern Bloc governments resorted to using lethal countermeasures against those trying to cross the border, such as mined fences and orders to shoot anyone trying to cross into the West. The restrictions on building and habitation made the area a "green corridor", which today is known as the European Green Belt. In the area stretching inwards from its internal border with the mainland, Hong Kong maintains a Frontier Closed Area out of bounds to those without special authorisation. The area was established in the 1950s, when Hong Kong was under British administration, as a result of the Convention for the Extension of Hong Kong Territory before the transfer of sovereignty over Hong Kong in 1997. The area's purpose was to prevent illegal immigration and smuggling; smuggling had become prevalent as a consequence of the Korean War.
Sources: en.wikipedia.org
A general synthetic route to organomercury compounds entails alkylation with Grignard reagents and organolithium compounds. Diethylmercury results from the reaction of mercury chloride with two equivalents of ethylmagnesium bromide, a conversion typically conducted in diethyl ether solution. Similarly, diphenylmercury can be prepared by reaction of mercury chloride and phenylmagnesium bromide. A related preparation entails formation of phenylsodium in the presence of mercury(II) salts. Hg(II) can be alkylated by treatment with diazonium salts in the presence of copper metal. In this way 2-chloromercuri-naphthalene has been prepared. 4-Chloromercuritoluene is obtained by the chloromercuration of sodium toluenesulfinite:
=== 27 June === In Donetsk Oblast, two people were killed by Russian shelling in Kurakhove, while one person was killed in a separate attack in Toretsk. The Ukrainian military claimed to have driven out Russian forces from the Kanal neighborhood of Chasiv Yar. Russian media reported that an explosion occurred at a chemical plant in Tver Oblast following a drone strike. The plant is believed to manufacture aviation fuel. According to local residents four drones struck the plant, damaging a workshop, pipeline and roof. No casualties were reported and Russian authorities claimed all four drones were destroyed.
A common substrate used in this type of system is glass. Depending if the system is open or closed, there would be either one or two layers of glass. The bottom layer of the device contains a patterned array of individually controllable electrodes. When looking at a closed system, there is usually a continuous ground electrode found through the top layer made usually of indium tin oxide (ITO). The dielectric layer is found around the electrodes in the bottom layer of the device and is important for building up charges and electrical field gradients on the device. A hydrophobic layer is applied to the top layer of the system to decrease the surface energy where the droplet will actually be in contact with. The applied voltage activates the electrodes and allows changes in the wettability of droplet on the device's surface. In order to move a droplet, a control voltage is applied to an electrode adjacent to the droplet, and at the same time, the electrode just under the droplet is deactivated. By varying the electric potential along a linear array of electrodes, electrowetting can be used to move droplets along this line of electrodes. Modifications to this foundation can also be fabricated into the basic design structure. One example of this is the addition of electrochemiluminescence detectors within the indium tin oxide layer (the ground electrode in a closed system) which aid in the detection of luminophores in droplets. In general, different materials may also be used to replace basic components of a DMF system such as the use of PDMS instead of glass for the substrate.
=== Intermediate host === In addition to direct spillover, another pathway, considered highly likely by scientists, is that of transmission through an intermediate host. Specifically, this implies that a cross species transmission occurred prior to the human outbreak and that it had pathogenic results on the animal. This pathway has the potential to allow for greater adaptation to human transmission via animals with more similar protein shapes to humans, though this is not required for the scenario to occur. The evolutionary separation from bat viruses is explained in this case by the virus's presence in an unknown species with less viral surveillance than bats. The virus's ability to easily infect and adapt to additional species (including mink) provides evidence that such a route of transmission is possible. A 2024 study of samples collected from Huanan Seafood Wholesale Market found genetic material of various possible intermediate hosts. The most likely were raccoon dogs. Additionally, the study suggests the raccoon dogs may have come from southern China, where the closest-known relatives to SARS-CoV-2 were found in bats.
== Signs and symptoms == The only sign of vitiligo is the presence of pale, patchy areas of depigmented skin, which tend to occur on the extremities. Some people may experience itching before a new patch appears. The patches are initially small, but often grow and change shape. When skin lesions occur, they are most prominent on the face, hands, and wrists. The loss of skin pigmentation is particularly noticeable around body orifices, such as the mouth, eyes, nostrils, genitalia and umbilicus. Some lesions have increased skin pigment around the edges. Additionally, the hair of affected areas can turn white or gray due to the loss of melanin. Those affected by vitiligo who are stigmatized for their condition may experience depression and similar mood disorders. Vitiligo also appears in other mammals, being conspicuous for instance on Arabian horses.
Sources: en.wikipedia.org
特沙莫瑞林是国际非专利名称,指一种经过 N 端修饰的生长激素释放激素类似物。它被归类为合成肽,序列与 GHRH(1-44) 密切相关。该名称不指代任何特定品牌或剂型。
监管批准集中于 HIV 感染相关的脂肪营养不良,目的是减少内脏脂肪。它未被批准用于普通肥胖或一般体重管理。不同国家的批准状态和标签范围可能不同。
长期心血管获益、死亡率影响以及停药后的持续性仍缺乏确证。部分研究提示 IGF-1 和血糖参数可能变化,但个体差异较大。这些开放问题需要更长期、更大规模的试验来回答。
It acts on the growth hormone–releasing hormone receptor, a Gs-coupled receptor found on pituitary somatotroph cells. Activation raises cAMP and prompts pulsatile hormone release.