This is a working overview of Somatotroph, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2026-01-05. 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.
Once reconstituted, the peptide is handled as a solution and is less stable than the lyophilized powder. Aqueous solutions are commonly kept cold and used within a defined period. Buffer composition and pH influence degradation rates, with extremes of acidity or alkalinity accelerating hydrolysis. Preservatives may be added in multi-dose formats to limit microbial growth. Freezing and thawing of solutions is generally avoided because it can cause precipitation or loss of activity.
Identity and purity are assessed by reversed-phase high-performance liquid chromatography, which separates the peptide from related impurities. Mass spectrometry, often coupled to liquid chromatography, confirms molecular mass and detects chemical modifications. Peptide mapping and amino acid analysis can verify sequence integrity. Water content is measured by Karl Fischer titration, and residual solvents may be checked by gas chromatography. These methods together support batch-to-batch consistency and routine quality control.
| 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 |
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.
Stability testing examines how the molecule changes under controlled stress. Thermal stress, light exposure, and extremes of pH are applied separately so that each degradation route can be attributed to a specific cause. The main observed changes are oxidation, deamidation, and aggregation into dimers or higher-order species. Accelerated studies at elevated temperature are used to estimate behavior over longer periods, though such extrapolation carries uncertainty. For a lyophilized powder, residual moisture and the choice of bulking agent strongly influence how quickly these changes appear.
Practical handling centers on limiting moisture, oxygen, and temperature excursions. Lyophilized material is generally held at or below minus twenty degrees Celsius, protected from light and kept sealed until use. Once reconstituted, solutions are typically kept cold and used within a short window because hydrolysis and microbial growth both accelerate in liquid form. Repeated freeze-thaw cycles are avoided, since they promote aggregation. Vial contents should be inspected for particulates and clarity before analysis, and working aliquots are prepared to reduce the number of times the stock is opened.
Pulp degeneration Increasing age Orthodontic treatment Traumatic occlusion Dental caries Pulp stones usually consist of circular layers of mineralised tissues. These layers are made up of blood clots, dead cells and collagen fibres. Occasionally, pulp stones appear surrounded by odontoblast-like cells that contain tubules. Pulp stones can reach as high as 50% in surveyed samples. Pulp stones are estimated to typically range from 8–9%. Pulpal calcifications are more common in females and more frequent in maxillary teeth compared to mandibular teeth. The reason is uncertain. They are more common in molar teeth, especially first molars compared to second molars and premolars. A review suggested this was because the first molars are the first teeth to be located in the mandible (lower jaw) and have longer exposure to degenerative changes. They also have a larger blood supply. In general, pulp stones do not require treatment. Depending on the stones' size and location, they may interfere with endodontic treatment and should be removed.
=== Tax avoidance === In June 2021, the United States Senate Finance Committee, under Chair Ron Wyden (D-OR), began an investigation to determine if the company took advantage of loopholes in the Tax Cuts and Jobs Act of 2017 to significantly reduce its tax liability. In a letter to AbbVie CEO Richard Gonzalez, Wyden noted the company suffered a 2020 pretax loss in the US of $4.5 billion and an overseas pretax profit of $7.9 billion the same year. The report, released in July 2022, showed that AbbVie was able to dodge U.S. taxes by registering intellectual property in offshore jurisdictions such as Bermuda. As a result, while AbbVie received 75% of its sales of Humira in the United States, it only reported 1% of that income for U.S. tax purposes.
lipid bilayer Also phospholipid bilayer. A lamellar structure composed of numerous amphipathic lipid molecules packed together in two back-to-back sheets or layers, with their hydrophobic fatty acid "tails" directed inward and their hydrophilic "heads" exposed on the outer surface. This is the basic structural motif for all biological membranes, including the plasma membrane surrounding all cells as well as the membranes surrounding organelles and vesicles. Though bilayers are sometimes colloquially described as phospholipid bilayers, phospholipids are just one of several classes of membrane lipids which form bilayers; most membranes are actually a fluid, heterogeneous mixture of phospholipids, glycolipids, and cholesterols, interspersed and studded with various other molecules such as integral proteins.
A great number of software tools for protein structure prediction exist. Approaches include homology modeling, protein threading, ab initio methods, secondary structure prediction, and transmembrane helix and signal peptide prediction. In particular, deep learning based on long short-term memory has been used for this purpose since 2007, when it was successfully applied to protein homology detection and to predict subcellular localization of proteins. Some recent successful methods based on the CASP experiments include I-TASSER, HHpred and AlphaFold. In 2021, AlphaFold was reported to perform best. Knowing the structure of a protein often allows functional prediction as well. For instance, collagen is folded into a long-extended fiber-like chain and it makes it a fibrous protein. Recently, several techniques have been developed to predict protein folding and thus protein structure, for example, Itasser, and AlphaFold.
Sources: en.wikipedia.org
Citrus greening disease (Chinese: 黃龍病; pinyin: huánglóngbìng abbr. HLB) is a disease of citrus trees caused by bacteria of the genus Liberibacter. These microbes are transmitted by two species of bug: the Asian citrus psyllid Diaphorina citri and the African citrus psyllid Trioza erytreae. It has no known cure. It is graft-transmissible. There are three different types of the disease: a heat-tolerant Asian form, and the heat-sensitive African and American forms. It was first described and reported in southern China in 1919. The African variation was first reported in 1937 in South Africa, where it is still widespread. It reached Florida in 2005, and within three years had spread to the majority of citrus farms. The rapid increase in this disease has threatened the citrus industry in the entire US. As of 2009, 33 countries had reported the infection in their citrus crop.
== Education and career == Hong grew up in China and completed her B.A. degree in chemistry from Mount Holyoke College (summa cum laude) in 1992 and a Ph.D. degree from the University of California, Berkeley in 1996. There she worked in the laboratory of Alexander Pines to investigate phospholipid structure and dynamics using variable-angle-spinning NMR. After a one-year postdoctoral stint in the laboratory of Robert G. Griffin at the Massachusetts Institute of Technology, she went to University of Massachusetts Amherst and developed biosynthetic isotopic labeling approaches to advance protein structure determination by ssNMR. She started an assistant professorship at Iowa State University in 1999, became an associate professor in 2002 and full professor in 2004, and held the first John D. Corbett Professorship from 2007 to 2010. In 2014, she returned to the Massachusetts Institute of Technology as a professor of chemistry.
RAMP2 KO mice also recapitulate the same phenotype, showing that major physiological effects of AM are transduced by the AM1 receptor. Even the heterozygote RAMP 2 mice have disturbed physiology with unusual bone and mammary gland defects, and very aberrant endocrinology, leading to poor fertility and lactation problems. What is very surprising is that the effect of deletion of RAMP3 has no deleterious effects and seems to confer advantages due to higher than normal bone mass, and reduced weight gain in older age.
== Treatment == The treatment for hyperprolactinemia is usually dependent upon its cause. There are many underlying factor that can cause hyperprolactinemia, some of them are hypothyroidism (disorder in which thyroid glands has a reduced thyroid hormone production), drug-induced hyperprolactinemia (such as antidepressant medication, antihypertensive medication and medication that can promotes bowel motility), hypothalamic disease(disorder caused by damage in the hypothalamus), idiopathic hyperprolactinemia (no recognized cause are present since there is no pituitary or central nervous disease present), macroprolactin (complex form of prolactin in the blood), or prolactinoma (non-cancerous tumor in the pituitary gland). Because there are so many underlying factors, to provide the proper management of hyperprolactinemia, the pathological form and physiological increase in prolactin levels are differentiated, and the correct cause of hyperprolactinemia must be identified before treatment. There are two types of functional hyperprolactinemia: symptomatic and asymptomatic. For functional asymptomatic hyperprolactinemia, the treatment of choice is removing the associated cause, including antipsychotic therapy. However, prolactin levels should be drawn and monitored both before any discontinuation or changes to therapy and afterwards.
== Human health == In addition to its significance for the field of evolutionary biology, de novo gene birth has implications for human health. It has been speculated that novel genes, including de novo genes, may play an outsized role in species-specific traits; however, many species-specific genes lack functional annotation. Nevertheless, there is evidence to suggest that human-specific de novo genes are involved in diseases such as cancer. NYCM, a de novo gene unique to humans and chimpanzees, regulates the pathogenesis of neuroblastomas in mouse models, and the primate-specific PART1, an lncRNA gene, has been identified as both a tumor suppressor and an oncogene in different contexts. Several other human- or primate-specific de novo genes, including PBOV1, GR6, MYEOV, and ELFN1-AS1, are also linked to cancer. Some have even suggested considering tumor-specifically expressed, evolutionary novel genes as their own class of genetic elements, noting that many such genes are under positive selection and may be neofunctionalized in the context of tumors. The specific expression of many de novo genes in the human brain also raises the intriguing possibility that de novo genes influence human cognitive traits. One such example is FLJ33706, a de novo gene that was identified in GWAS and linkage analyses for nicotine addiction and shows elevated expression in the brains of Alzheimer's patients. Further research, however, showed that FLJ33706 and other de novo gene candidates expressed in the human brain are either not translated or are diverged duplicates.
Sources: en.wikipedia.org
=== David Healy === David Maurice Healy is played by Johnny Galecki. David is Mark Healy's younger brother. He first appeared in "The Bowling Show" (episode 4.14). Whereas Mark was initially a rebellious delinquent, David is friendly and respectful to the Conners. He is shy, polite, thoughtful, sensitive, soft-spoken, artistic, and intelligent. Much of his passive behavior results from his difficult home life and his mother's abusive behavior. He is romantically involved with Darlene, becoming the submissive partner. They also collaborate artistically, with David illustrating graphic novels that Darlene writes. His sweet manner endears him to the Conners, who eventually consider him as part of the family and jokingly refer to him as being more welcome than Darlene. He moves in with the Conners after Roseanne, herself a victim of child abuse, witnesses how abusive David's mother is. David and Darlene break up three times throughout the series, each for a successively longer period of time, but always reunite. After Darlene becomes pregnant, she and David married. In the series finale, Roseanne reveals in her writing that David had actually been dating Becky in "real life", and that Roseanne simply wrote his relationship as being with Darlene because she felt it made more sense. The series finale is retconned for season 10, where it is revealed that David and Darlene have been separated for some years and David has been away, traveling and doing volunteer work abroad, leaving Darlene to raise their two children, Harris and Mark, as a single mother.
This rearrangement demonstrates that similar to the Michaelis–Menten equation, the maximal rate of reaction depends on the proportion of the enzyme population interacting with its substrate. fraction of the enzyme population bound by substrate
The expansion of Toronto in the east, in the 19th century, led to the development of housing stock along the Kingston Road and Danforth Road corridors in Scarborough. This led to the creation of a transit line. In 1893, the Toronto and Scarboro' Electric Railway, Light and Power Company built a single-track radial line along Kingston Road to Blantyre. Over the next 13 years this was extended to West Hill. In 1904, the line became the Scarboro Division of the Toronto and York Radial Railway. Service continued along this line until 1936 when it was replaced by bus service.
January 3, 2013: Decree establishing an interministerial mission for the protection of women against violence and the fight against human trafficking. January 3, 2013: Decree establishing the High Council for Gender Equality. January 31, 2013: Law repealing Law No. 2010-1127 of September 28, 2010, aimed at combating school absenteeism. May 17, 2013: Law on the election of departmental, municipal, and community councillors and modifying the electoral calendar. May 17, 2013: Law opening marriage to same-sex couples. June 19, 2013: National interprofessional agreement "Toward a policy of improving quality of life at work and professional equality." July 8, 2013: Orientation and programming law for the refoundation of the Republic's school system. July 22, 2013: Law on higher education and research, notably requiring gender parity in elections and appointments to governance bodies of institutions. August 2, 2013: Law on the election of senators, introducing measures to increase female representation. August 5, 2013: Law on various adjustments in justice according to EU law and France's international commitments. November 2013: Fourth interministerial plan for preventing and combating violence against women. December 2013: Bill on combating the prostitution system. December 27, 2013: Decree on the annual report on professional equality in the civil service. January 20, 2014: Law ensuring the future and fairness of the pension system. April 16, 2014: Decree on the responsibilities of the Minister for Women's Rights, Cities, Youth, and Sports.
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.
Refrigeration between 2 and 8 degrees Celsius is typical, with protection from moisture and light. Dry, sealed containers help maintain stability over the labeled shelf life. Temperature cycling is usually minimized.