Everything below concerns cjc-1295. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Last reviewed on 2025-10-13. Where a claim depends on a specific study, the study is described rather than over-claimed.
Once in circulation, the peptide binds the growth hormone-releasing hormone receptor displayed on pituitary somatotroph cells. Receptor activation couples to Gs proteins, elevates intracellular cyclic AMP, and drives protein kinase A signaling inside the cell. That cascade increases discharge of growth hormone into the bloodstream. The analog therefore operates through a receptor pathway that already exists for the body's own releasing hormone, rather than through an engineered artificial target.
Clearance profiles diverge sharply between the two versions. The albumin-binding molecule stays in plasma for several days, whereas the unmodified analog is largely gone within about half an hour in reported work. Cleavage by dipeptidyl peptidase IV is a major contributor to the short life of the unmodified sequence. These gaps mean the two versions cannot be substituted for each other in study design or in reading results side by side.
CJC-1295 is a synthetic peptide designed as a long-acting analogue of growth hormone-releasing hormone (GHRH). Its structure derives from the first 29 amino acids of native GHRH, a fragment often called GRF(1-29). Four substitutions were introduced to slow enzymatic breakdown and extend activity relative to the natural sequence. The compound was developed by ConjuChem as part of a broader effort to improve the pharmacokinetic profile of peptide hormones. It is studied in laboratory and clinical research settings rather than appearing as a naturally occurring substance.
Two related forms circulate in technical discussion under the same family name. The original version carries a drug affinity complex (DAC) that binds covalently to serum albumin after administration, and this linkage substantially extends circulation time. A second form, frequently written as modified GRF(1-29) or CJC-1295 without DAC, lacks that linker and clears much faster. The naming is a frequent source of confusion because the shorthand CJC-1295 can refer to either form depending on the source. Reports sometimes fail to specify which variant was studied.
The peptide backbone includes a D-alanine at position two, which resists cleavage by dipeptidyl peptidase IV, and several other substitutions that reduce degradation. Its molecular weight is roughly 3.4 kDa without the linker and about 3.6 kDa with it. The molecule is water soluble and is normally supplied as a lyophilized powder. Precise sequence and mass values depend on which variant is described, so technical documents usually state the exact form being referenced.
| Property | Value | Notes |
|---|---|---|
| Primary target | GHRH receptor | Present on pituitary somatotroph cells |
| Signal pathway | Gs, cyclic AMP, protein kinase A | Sequence follows receptor activation |
| Main measured effect | Growth hormone release | Insulin-like growth factor 1 shifts indirectly |
| Half-life, binding form | Several days | Extended through serum albumin association |
| Half-life, unmodified form | About 30 minutes | Limited mainly by enzymatic cleavage |
CJC-1295 is a synthetic peptide belonging to the growth hormone-releasing hormone analog family. It comprises twenty-nine amino acid residues derived from the N-terminal region of natural GHRH. The molecule incorporates several non-natural substitutions that increase resistance to enzymatic degradation. These modifications extend its activity compared with the native hormone fragment. Researchers use it to study pituitary growth hormone secretion in laboratory and clinical settings. This compound is distinct from native GHRH in its stability profile.
Two principal forms appear in the literature and in research supply. One carries a drug affinity complex, a maleimide-based group that forms a covalent bond with circulating albumin. This linkage slows clearance and produces a long-lasting elevation of peptide levels. The other form lacks that group and is often labeled MOD GRF(1-29). It has a much shorter circulation time. Both variants retain the same core receptor-binding sequence. Reported half-lives differ substantially between the two.
Two related forms appear under the CJC-1295 name. The simpler analogue, commonly written as modified GRF(1-29), carries the four substitutions but no additional conjugation. The second form attaches a maleimidopropionic acid linker to a lysine residue, a modification frequently called the drug affinity complex. That linker reacts with the free thiol on serum albumin to form a covalent bond. Because albumin has a long residence time in blood, the conjugated peptide stays in circulation far longer than the unconjugated analogue.
Receptor level activity follows the canonical GHRH pathway. The peptide binds the GHRH receptor, a class B G protein coupled receptor on somatotroph cells of the anterior pituitary. Binding raises intracellular cyclic AMP, which promotes calcium entry and the release of growth hormone into the bloodstream. Because the molecule acts at the same receptor as the endogenous hormone, its effect is superimposed on the natural pulsatile rhythm rather than replacing it. Whether sustained receptor occupation leads to desensitization is not fully settled.
The second form adds a maleimide-bearing linker to the lysine at the carboxyl end. This group reacts with cysteine-34 on circulating serum albumin, forming a covalent bond that keeps the peptide in the bloodstream for far longer. ConjuChem developed the molecule as a way to extend the action of a peptide without frequent administration. The albumin attachment is the defining structural feature of the drug affinity complex version. Whether continuous exposure produces effects distinct from shorter pulses remains an unresolved research question.
CJC-1295 belongs to a family of synthetic peptides modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound is built from the first twenty-nine amino acids of the natural human sequence, a fragment that retains full receptor binding capacity. Native growth hormone-releasing hormone is degraded quickly in circulation, so the fragment alone has limited practical value. Early work therefore focused on chemical modifications that preserve receptor binding while slowing enzymatic breakdown. The result is a molecule described in the literature as a long-acting analog of the natural hormone.
CJC-1295 is a synthetic analogue of growth hormone-releasing hormone, built on the 29-amino-acid GHRH(1-29) fragment. Four substitutions distinguish it from the natural sequence: D-alanine at position 2, glutamine at position 8, alanine at position 15, and leucine at position 27. These changes reduce enzymatic cleavage and extend the peptide's persistence in circulation. The compound is discussed in two forms, one carrying a drug affinity complex and one without it.
The drug affinity complex is a maleimidopropionic acid group attached to a lysine side chain. It reacts with the free thiol of cysteine-34 on circulating albumin, forming a covalent bond. This conjugation keeps the peptide in the bloodstream and shields it from rapid renal filtration and proteolysis. Reported circulation half-lives for the albumin-bound form fall in the range of roughly six to nine days in early human studies.
Binding to GHRH receptors on pituitary somatotroph cells triggers cyclic AMP signaling and stimulates growth hormone synthesis and release. Because the peptide acts upstream of the pituitary, effects are mediated through endogenous growth hormone rather than direct receptor activation in peripheral tissues. Increases in insulin-like growth factor 1 are generally described as a downstream consequence. Most published human exposure data come from small early-stage studies, and the clinical significance of the pharmacokinetic profile remains incompletely characterized.
Barbara Seliger Larsen is a mass spectrometrist, with a career in instrumentations and applications of mass spectrometry in industry, and served on the board of the American Society for Mass Spectrometry for several terms.
For example, most crustose lichens have intracellular haustoria, whereas foliose and fruticose lichens tend to have intraparietal ones. In lichens whose Trebouxia partner bears a sporopollenin-rich wall, the fungus cannot penetrate and resorts to the intraparietal strategy. The interface therefore records co-evolution, and haustorial type may flag evolutionary shifts or delimit higher taxa. Scanning-electron microscopy (SEM) and freeze-etching next exposed the outer surfaces of lichen hyphae. Honegger (1984) freeze-fractured thalli to reveal successive wall layers and surface textures. She showed that symbiotic hyphae develop characteristic coatings: Peltigera species carry dense protein rodlets, whereas genera such as Parmelia and Cladonia display patchy, maze-like mosaics. Cultured (non-symbiotic) isolates lack these coatings, confirming their symbiotic origin. Because wall textures are consistent within genera or families, they became additional diagnostic traits. Functionally, the coatings likely improve adhesion to the algal partner. Freeze-etch images also revealed matching pits or projections in the algal wall, forming an interlocking contact surface. These precise contact structures demonstrate how symbiotic integration can produce distinctive morphological characters. Together with haustorial form, these ultrastructural characters aid genus- or family-level delimitation and illuminate how often particular symbiotic mechanisms evolved—issues now revisited with molecular datasets.
As well as being extracted from nuclear waste, radioisotopes can be produced deliberately with nuclear reactors, exploiting the high flux of neutrons present. These neutrons activate elements placed within the reactor. A typical product from a nuclear reactor is iridium-192, from activation of iridium targets. The elements that have a large propensity to take up neutrons in the reactor are said to have a high neutron cross-section, but even at low cross-sections this process is generally economical. Particle accelerators such as cyclotrons accelerate particles to bombard a target to produce radionuclides. Cyclotrons accelerate (most often) protons at a target to produce positron-emitting radionuclides, e.g. fluorine-18. Radionuclide generators, standard for many medical isotopes, contain a parent radionuclide that decays to produce a shorter-lived radioactive daughter. A typical example is the technetium-99m generator, which employs molybdenum-99 produced in a reactor.
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== Development and regulation in the United States == The solid filiform needle used in dry needling is regulated by the FDA as a Class II medical device described in the code titled "Sec. 880.5580 Acupuncture needle is a device intended to pierce the skin in the practice of acupuncture". Per the Food and Drug Act of 1906 and the subsequent amendments to said act, the FDA definition applies to how the needles can be marketed and does not mean that acupuncture is the only medical procedure where these needles can be used. Dry needling using such a needle contrasts with the use of a hollow hypodermic needle to inject substances such as saline solution, botox or corticosteroids to the same point. The founder of Integrative Systemic Dry Needling (ISDN), Yun-Tao Ma, has spearheaded the "dry needling" movement in the United States. Ma states, "Although ISDN originated in traditional Chinese methods, it has developed from the ancient empirical approach to become modern medical art rooted in evidence-based thinking and practice." Ma also states that, "Dry needling technique is a modern Western medical modality that is not related to traditional Chinese acupuncture in any way. Dry needling has its own theoretical concepts, terminology, needling technique, and clinical application."
== Pronunciation == Pronunciation follows convention outside the medical field, in which acronyms are generally pronounced as if they were a word (JAMA, SIDS), initialisms are generally pronounced as individual letters (DNA, SSRI), and abbreviations generally use the expansion (soln. = "solution", sup. = "superior"). Abbreviations of weights and measures are pronounced using the expansion of the unit (mg = "milligram") and chemical symbols using the chemical expansion (NaCl = "sodium chloride"). Some initialisms deriving from Latin may be pronounced either as letters (qid = "cue eye dee") or using the English expansion (qid = "four times a day").
Biography at the Biographical Directory of the United States Congress Financial information (federal office) at the Federal Election Commission Legislation sponsored at the Library of Congress Profile at Vote Smart Campaign contributions at OpenSecrets.org Follow the Money – John Kennedy 2007 2005 2003 1999 Louisiana Treasurer campaign contributions
Sources: en.wikipedia.org
The measured value of a parameter is displayed and recorded locally and/or in a control room. If the measured variable exceeds pre-defined limits an alarm warns the operating personnel of a potential problem. Automatic executive action is taken by the instrumentation to close or open shutdown valves and dampers, or to trip (stop) pumps and compressors, to move the plant to a safe condition. Correct operation of the petrochemical process plant is achieved through the action of control loops. These automatically maintain and control the pressure, temperature, liquid level and flowrate of fluid in vessels and piping. Control loops compare the measured value of a parameter on the plant, eg. pressure, with a pre-determined set point. A difference between the measured variable and the set point generates a signal which modulates the position of a control valve (the final element) to maintain the measured variable at the set point. Valves are actuated by an electric motor, hydraulic fluid or air. For air-operated control valves, electrical signals from the control system are converted to an air pressure for the valve actuator in a current/pneumatic I/P converter. Upon loss of pneumatic or hydraulic pressure valves may fail to an open (FO) or fail to a closed (FC) position. Some instrumentation is self actuating. For example, pressure regulators maintain a constant pre-set pressure, and rupture discs and pressure safety valves open at pre-set pressures. Instrumentation includes facilities for operating personnel to intervene in the plant either locally or from a control room.
Chondrocytes will proliferate too quickly and disrupt the assembly at the cartilage anlage and detrimentally alter the formation of bone. This mutation acts in a dosage fashion, meaning that when only one copy is present, there is still an uptake in FGF expression, but less so than when there are two copies of the mutation.
=== Stem cells === There is a bioengineering technique that uses stem cells to create corneas or part of corneas that can be transplanted into the eyes. Corneal stem cells are removed from a healthy cornea. They are collected and, through laboratory procedures, made into five to ten layers of cells that can be stitched into a patient's eye. The stem cells are placed into the area where the damaged cornea tissue has been removed. This is a good alternative for those that cannot gain vision through regular cornea transplants. A new development, announced by the University of Cincinnati Medical School in May 2007, would use bone marrow stem cells to regrow the cornea and its cells. This technique, which proved successful in mouse trials, would be of use to those with inherited genetic degenerative conditions of the cornea, especially if other means like a transplant are not feasible. It works better than a transplant because these stem cells keep their ability to differentiate and replicate, and so keep the disease from recurring, longer and better.
All of astatine's isotopes are short-lived; the most stable is astatine-210, with a half-life of 8.1 hours. There are 41 known isotopes of astatine, with mass numbers of 188 and 190–229. Theoretical modeling suggests that about 37 more isotopes could exist. No stable or long-lived astatine isotope has been observed, nor is one expected to exist. Astatine's alpha decay energies follow the same trend as for other heavy elements. Lighter astatine isotopes have quite high energies of alpha decay, which become lower as the nuclei become heavier. Astatine-211 has a significantly higher energy than the previous isotope, because it has a nucleus with 126 neutrons, and 126 is a magic number corresponding to a filled neutron shell. Despite having a similar half-life to the previous isotope (8.1 hours for astatine-210 and 7.2 hours for astatine-211), the alpha decay probability is much higher for the latter: 41.81% against only 0.18%. The two following isotopes release even more energy, with astatine-213 releasing the most energy. For this reason, it is the shortest-lived astatine isotope. Even though heavier astatine isotopes release less energy, no long-lived astatine isotope exists, because of the increasing role of beta decay (electron emission). This decay mode is especially important for astatine; as early as 1950 it was postulated that all isotopes of the element undergo beta decay, though nuclear mass measurements indicate that 215At is in fact beta-stable, as it has the lowest mass of all isobars with A = 215.
Sources: en.wikipedia.org
It acts on the growth hormone-releasing hormone receptor found on pituitary somatotroph cells. Activation of that receptor triggers growth hormone release through a cyclic AMP dependent pathway.
It links the peptide to serum albumin after administration, which delays removal from circulation. Reported half-life shifts from roughly half an hour to several days as a result.
Most published work tracks serum growth hormone and insulin-like growth factor 1 over time. Sampling schedules and assay methods vary enough that figures are not directly comparable across reports.
No. It is a synthetic analogue modeled on the first 29 residues of human GHRH. The substitutions and any linker are laboratory modifications rather than features of the endogenous peptide.