Everything below concerns mass spectrometry. We keep the language plain, cite what the science says, and separate well-supported claims from open questions.
Updated 2025-11-05. Numbers and descriptions here follow the published literature rather than marketing material.
Naming in this area is inconsistent, and readers should treat product labels with care. In much of the literature and in vendor catalogs, the unqualified term refers to the albumin-binding version, while the version lacking the DAC group appears as modified GRF(1-29), mod GRF(1-29), or the same name with a without-DAC qualifier. Because one abbreviation has been applied to both materials, the only reliable way to identify a sample is to check the stated sequence and the presence of the linker.
CJC-1295 is the name used for a synthetic peptide modeled on growth hormone-releasing hormone, the hypothalamic signal that prompts the pituitary to release growth hormone. The compound was described by a Canadian drug discovery company in the mid-2000s as a long-acting research tool. Two closely related molecules share the name in practice: one carries a drug affinity complex, or DAC, group, and one does not. The distinction matters because the two behave differently in circulation.
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.
CJC-1295 belongs to a class of synthetic peptides modeled on growth hormone releasing hormone, a forty-four amino acid signal produced by the hypothalamus. The compound is built from the first twenty-nine residues of the natural sequence, with four substitutions introduced at positions 2, 8, 15 and 27. These changes were designed to slow enzymatic breakdown while preserving receptor activation. The result is a peptide that is shorter than native GHRH and considerably more resistant to ordinary clearance pathways in circulation.
| Property | Value | Notes |
|---|---|---|
| Molecular class | Synthetic peptide | GHRH analog, not a steroid |
| Backbone length | 29 amino acids | Based on GRF(1-29) |
| Substitutions | Four positions | D-Ala2, Gln8, Ala15, Leu27 |
| Appearance | White to off-white powder | Typical lyophilized research material |
| Common synonyms | Modified GRF(1-29) | Usage varies between sources |
Two forms circulate in research settings and are frequently confused. One carries the drug affinity complex and is often written as CJC-1295 with DAC; the other lacks that group and is usually called modified GRF(1-29). The two share the same core sequence but differ sharply in how long they persist in blood. Products labelled only as CJC-1295 normally refer to the version carrying the complex. Documentation that omits the distinction leaves the intended molecule ambiguous.
CJC-1295 is a synthetic peptide built as a long-acting analogue of growth hormone-releasing hormone. Its backbone matches the first twenty-nine residues of the natural human hormone, with four amino acid substitutions added to slow enzymatic breakdown. A reactive maleimide group, commonly termed the drug affinity complex, allows the peptide to attach to circulating albumin after administration. That albumin attachment keeps the molecule in the bloodstream for an extended period instead of being cleared within minutes.
The compound emerged from work at a Canadian biotechnology firm in the early 2000s. Early human studies examined its effect on growth hormone and insulin-like growth factor 1 in healthy volunteers and in people with HIV-associated fat redistribution. Reports described sustained increases in both markers after a single injection. Development did not advance to regulatory approval, and the clinical programme was later discontinued. The molecule is now encountered mainly as a research chemical rather than a marketed medicine.
Enzymatic protection is a separate mechanism from plasma protein binding. The four substitutions in the backbone reduce recognition by dipeptidyl peptidase IV, which normally cleaves the natural hormone within minutes. Without the reactive group, this resistance still yields only a short window of activity, generally reported in the range of tens of minutes. With it, reported half-lives in early human work extended to several days. The size of that gap is the main practical distinction between the two materials.
Both forms act at the pituitary receptor for growth hormone-releasing hormone and increase growth hormone output, which in turn raises insulin-like growth factor 1. A long-acting analog produces sustained rather than pulsatile stimulation, and the physiological consequences of that pattern are not fully settled. Published human data on the extended form remain limited, and much of what circulates in discussion traces to early company reports rather than independent replication. How sustained exposure affects normal feedback remains an open question.
The distinguishing feature of the DAC form is a maleimide-containing group that reacts with the free thiol of cysteine-34 on human serum albumin. This reaction forms a covalent bond without enzymatic assistance, and it takes place after the peptide enters the bloodstream. Because albumin is abundant and long-lived, the attached peptide is carried through circulation far longer than an unmodified fragment would survive. The chemistry is a deliberate pharmacokinetic strategy rather than a change to receptor activity.
Identity and purity are established with reversed phase high performance liquid chromatography coupled to mass spectrometry. The chromatographic step separates the target peptide from truncated sequences and deletion products, while the mass measurement confirms the expected molecular weight to within a fraction of a dalton. Because the two common variants differ by the presence of the linker, mass alone can distinguish them in the unconjugated state. Amino acid analysis and peptide mapping are used when sequence level confirmation is required.
Lyophilized material is generally stable for extended periods when held at minus twenty degrees Celsius or below and protected from moisture and light. In solution the peptide is more labile; bond hydrolysis, aggregation and oxidation of susceptible residues all proceed faster at ambient temperature. Repeated freeze and thaw cycles should be avoided because they promote clumping and loss of soluble material. The conjugated variant adds a further consideration, since the maleimide group can hydrolyze in aqueous buffer and lose its ability to react with albumin.
CJC-1295 acts at the growth hormone-releasing hormone receptor, a G-protein-coupled receptor found on somatotroph cells in the anterior pituitary. Binding triggers a rise in cyclic AMP and calcium entry, which promotes release of stored growth hormone. Because the peptide mimics the body's own releasing hormone, it amplifies existing secretory pulses rather than driving continuous output. The size of the response therefore depends partly on the subject's own hormonal rhythm and feedback state.
The attached maleimide group explains the unusual duration of the DAC version. After injection it reacts with the thiol of cysteine-34 on serum albumin, forming a stable covalent bond. The resulting conjugate is too large for rapid kidney filtration and is shielded from many peptidases. Reported half-lives for this form reach several days, whereas the version without the group is cleared in roughly half an hour. That gap is the main pharmacological difference between the two.
Downstream of growth hormone, the liver and other tissues increase production of insulin-like growth factor 1, a mediator of many growth-promoting effects. Studies have documented elevated levels of both hormones after dosing, and the rise from the long-acting form persists longer than that produced by shorter-acting analogues. What remains unclear is whether sustained elevation of these markers translates into meaningful clinical benefit, and whether prolonged exposure carries risks that short trials could not detect.
=== Table I === acetic anhydride N-Acetylanthranilic acid ephedrine ergometrine ergotamine isosafrole lysergic acid 3,4-methylenedioxyphenyl-2-propanone norephedrine phenylacetic acid 1-phenyl-2-propanone alpha-phenylacetoacetonitrile (APAAN) piperonal potassium permanganate pseudoephedrine safrole The salts of the substances listed in this Table whenever the existence of such salts is possible.
Higher blood pressure will require higher external pressure on the nerve to disrupt its microvascular environment. The critical pressure necessary to disrupt the blood supply of a nerve is approximately 30mm Hg below diastolic blood pressure or 45mm Hg below mean arterial pressure. For normohypertensive (normal blood pressure) adults, the average values for systolic blood pressure is 116mm Hg diastolic blood pressure is 69mm Hg. Using this data, the average person would become symptomatic with approximately 39mm Hg of pressure in the wrist (69 - 30 = 39 and 69 + (116 - 69)/3 - 45 ~ 40). Carpal tunnel syndrome patients tend to have elevated carpal tunnel pressures (12-31mm Hg) compared to controls (2.5 - 13mm Hg). Applying pressure to the carpal tunnel of normal subjects in a lab can produce mild neurophysiological changes at 30mm Hg with a rapid, complete sensory block at 60mm Hg. Carpal tunnel pressure may be affected by wrist movement/position, with flexion and extension capable of raising the tunnel pressure as high as 111mm Hg. Many of the activities associated with carpal tunnel symptoms such as driving, holding a phone, etc. involve flexing the wrist and it is likely due to an increase in carpal tunnel pressure during these activities. Nerve compression can result in various stages of nerve injury. The majority of carpal tunnel syndrome patients have a degree I nerve injury (Sunderland classification), also called neuropraxia. This is characterized by a conduction block, segmental demyelination, and intact axons.
== Places == Šip (Pale), Bosnia and Herzegovina Šip (Višegrad), Bosnia and Herzegovina Novi Sip, Serbia Simferopol International Airport (IATA: SIP), an airport in Crimea Suzhou Industrial Park, in Suzhou, China
Fu's Subcutaneous Needle (FSN), invented by Dr. Zhonghua Fu in 1996, is a method for the treatment of myofascial pain and trigger points related to Traditional Chinese Medicine (TCM) and invented by Dr. D. Simons and Dr. Janet G. Travell. FSN does not follow the rules and principles of TCM and the chosen insertion points do not coincide with traditional acupuncture points. The similarities are limited to the distal insertion of the needle to the affected area, the needle itself being a non-injection needle, and the fact that both needles are manipulated and act on soft connective tissue. FSN abstains from the muscle and deep fascia layers and is confined to only the subcutaneous layer where collagen fibers are most abundant. As the subcutaneous layer is poorly innervated, pain is less than other needling therapies. FSN is also currently being used to treat non-musculoskeletal conditions; however more research is to be carried out to conclude its effectiveness.
Scottish scientist James W. Black developed propranolol in the 1960s. It was the first beta blocker effectively used in the treatment of coronary artery disease and hypertension. Black received the Nobel Prize in Physiology or Medicine in 1988 for this discovery. Propranolol is on the WHO Model list of essential medicines. Newer, more cardio-selective beta blockers (such as bisoprolol, nebivolol, carvedilol, or metoprolol) are used preferentially in the treatment of hypertension.
Sources: en.wikipedia.org
== Dosage and imaging == The typical adult dose for a lung imaging study is 40-150 Megabecquerels (1-4 mCi) (containing between 100,000 - 200,000 albumin particles). The particle burden should be lowered for most pediatric patients and lowered to 50,000 for infants. The use of more than 250,000 particles in a dose is controversial as little extra data is acquired from such scans while there is an increased risk of toxicity. Patients with pulmonary hypertension should be administered a minimum number of particles to achieve a lung scan (i.e. 60,000). In any patient by administering a greater quantity of particles than necessary for the diagnostic procedure increases the risks of toxicity. Because of gravity effects, people administered 99mTc MAA should be in the supine position to ensure as even a distribution of particles throughout the lungs as possible. The total percentage of particles trapped in the lungs can be determined through a whole body scan after the administration of 99mTc MAA through the equation:
== Reactions == Hippuric acid is readily hydrolysed by hot caustic alkalis to benzoic acid and glycine. Nitrous acid converts it into benzoyl glycolic acid, C6H5C(=O)OCH2CO2H. Its ethyl ester reacts with hydrazine to form hippuryl hydrazine, C6H5CONHCH2CONHNH2, which was used by Theodor Curtius for the preparation of hydrazoic acid. Hippuric acid has also been used in Erlenmeyer–Plöchl synthesis of phenylalanine and other amino acids, the reaction proceeding via an oxazolone or "azlactone" intermediate.
== Early life == Smolková-Keulemansová was born on 27 April 1927 in Prague, Czechoslovakia (now the Czech Republic) to a Jewish family. She had a normal childhood in Czechoslovakia as an only child to her parents Alice and Oskar. She finished primary school and had started grammar school but was taken out of school by her father after anti-Jewish laws started applying to grammar schools. She was employed at various Jewish workshops after leaving school.
== Functions == There are currently ten known prostaglandin receptors on various cell types. Prostaglandins ligate a sub-family of cell surface seven-transmembrane receptors, G-protein-coupled receptors. These receptors are termed DP1-2, EP1-4, FP, IP1-2, and TP, corresponding to the receptor that ligates the corresponding prostaglandin (e.g., DP1-2 receptors bind to PGD2). The diversity of receptors means that prostaglandins act on an array of cells and have a wide variety of effects such as:
Treatment of osteoporosis or non-malignant bone disease with oral bisphosphonates for <5 years (not taking systemic glucocorticoids) Treatment of osteoporosis or non-malignant bone disease with quarterly/yearly infusions of intravenous bisphosphonates for <5 years (not taking systemic glucocorticoids) Treatment of osteoporosis or non-malignant bone disease with denosumab (not taking systemic glucocorticoids) High:
Sources: en.wikipedia.org
To fix carbon dioxide into sugar molecules in the process of photosynthesis, chloroplasts use an enzyme called RuBisCO. RuBisCO has trouble distinguishing between carbon dioxide and oxygen, so at high oxygen concentrations, RuBisCO starts accidentally adding oxygen to sugar precursors. This has the result of ATP energy being wasted and CO2 being released, all with no sugar being produced. This is a big problem, since O2 is produced by the initial light reactions of photosynthesis, causing issues down the line in the Calvin cycle which uses RuBisCO. C4 plants evolved a way to solve this—by spatially separating the light reactions and the Calvin cycle. The light reactions, which store light energy in ATP and NADPH, are done in the mesophyll cells of a C4 leaf. The Calvin cycle, which uses the stored energy to make sugar using RuBisCO, is done in the bundle sheath cells, a layer of cells surrounding a vein in a leaf. As a result, chloroplasts in C4 mesophyll cells and bundle sheath cells are specialized for each stage of photosynthesis. In mesophyll cells, chloroplasts are specialized for the light reactions, so they lack RuBisCO, and have normal grana and thylakoids, which they use to make ATP and NADPH, as well as oxygen. They store CO2 in a four-carbon compound, which is why the process is called C4 photosynthesis. The four-carbon compound is then transported to the bundle sheath chloroplasts, where it drops off CO2 and returns to the mesophyll.
With Robert J. Flaherty's Nanook of the North in 1922, documentary film embraced romanticism. Flaherty filmed a number of heavily staged romantic documentary films during this time period, often showing how his subjects would have lived 100 years earlier and not how they lived right then. For instance, in Nanook of the North, Flaherty did not allow his subjects to shoot a walrus with a nearby shotgun, but had them use a harpoon instead. Some of Flaherty's staging, such as building a roofless igloo for interior shots, was done to accommodate the filming technology of the time. Paramount Pictures tried to repeat the success of Flaherty's Nanook and Moana with two romanticized documentaries, Grass (1925) and Chang (1927), both directed by Merian C. Cooper and Ernest Schoedsack.
=== Disintermediation === Disintermediation occurs when manufacturers or service providers eliminate intermediaries from the distribution network and deal directly with purchasers. Disintermediation is found in industries where radically new types of channel intermediaries displace traditional distributors. The widespread public acceptance of online shopping has been a major trigger for disintermediation in some industries. Certain types of traditional intermediaries are dropping by the wayside.
Active sonar uses the reflection of sound emitted from the search equipment to detect submarines. It has been used since WWII by surface ships, submarines and aircraft (via dropped buoys and helicopter "dipping" arrays), but it reveals the emitter's position, and is susceptible to counter-measures. A concealed military submarine is a real threat, and because of its stealth, can force an enemy navy to waste resources searching large areas of ocean and protecting ships against attack. This advantage was vividly demonstrated in the 1982 Falklands War when the British nuclear-powered submarine HMS Conqueror sank the Argentine cruiser General Belgrano. After the sinking the Argentine Navy recognized that they had no effective defense against submarine attack, and the Argentine surface fleet withdrew to port for the remainder of the war. An Argentine submarine remained at sea, however.
Sources: en.wikipedia.org
No. It is a laboratory-made analog of growth hormone-releasing hormone. The natural hormone is a 44-residue peptide, while the analog is built on a shorter 29-residue fragment.
The original material included a linker that binds serum albumin. A later variant removed that linker to reduce the duration of action. Catalogs and papers did not consistently adopt separate names, so both remain widely labeled with the same term.
The amino acid sequence and the presence or absence of the linker group. Mass measured by spectrometry gives an independent check that separates the two forms.
The names are often used interchangeably in casual writing, but they are not strictly identical. Modified GRF(1-29) refers to the unconjugated analogue carrying only the four substitutions. The version sold as CJC-1295 with DAC includes the albumin binding linker and clears much more slowly.