This is a working overview of peptidase cleavage, written for readers who want more than a one-paragraph summary but less than a textbook.
Reviewed 2025-11-05. Anything still debated is marked as such rather than presented as settled.
Published research covers ischemic stroke, traumatic brain injury, cognitive impairment, optic nerve conditions and attention-related measures. Much of the human evidence comes from small trials conducted in one country, which limits how far the results generalize. Animal models supply the larger share of the data, and effects seen in rodents do not transfer automatically to people. Reviews have noted that methodological reporting is often incomplete, making it difficult to pool results or compare treatment schedules across studies.
Pharmacokinetic accounts emphasize rapid breakdown. After intravenous dosing the intact peptide disappears from blood within minutes, and nasal delivery produces low but measurable concentrations. Metabolites rather than the parent molecule may account for part of the observed activity, although the relative contribution is unresolved. Dosing in the literature varies widely and no optimal schedule has been agreed. These gaps are regularly cited as a reason the findings have not produced broad clinical adoption beyond the original research setting.
Proposed mechanisms center on neurotrophic signaling rather than on classical melanocortin receptor activation. Rodent experiments have reported shifts in the expression of brain-derived neurotrophic factor and nerve growth factor after administration, together with changes in the associated receptor systems. Several authors argue that the peptide acts largely through its degradation products and their interaction with peptidergic pathways, but this remains a hypothesis rather than a settled finding. No single molecular target has been identified in a way that the field broadly accepts.
Circulation time for the peptide is short because peptidases cleave it readily. The Pro-Gly-Pro tail is thought to slow breakdown compared with the bare ACTH fragment, but the gain appears modest. Absorption after intranasal dosing is limited, and only a fraction of a dose is expected to reach the central nervous system. Laboratory concentrations therefore sit well above levels achieved systemically, a gap that complicates translation from bench findings to clinical claims.
The mechanisms attributed to semax are inferred from animal and cell studies rather than traced to one confirmed target. The most frequently cited pathway involves increased expression of brain-derived neurotrophic factor and nerve growth factor in hippocampal and cortical tissue. Some work points to engagement of melanocortin receptors, particularly MC4, which the parent ACTH fragment can activate. Effects on dopaminergic and serotonergic signalling have also been reported. No single account explains all observed results, and the relative weight of each pathway remains unsettled.
Published studies examine a fairly narrow set of endpoints. Rodent experiments commonly measure maze learning, infarct volume after induced ischemia, and tissue levels of neurotrophic factors. Clinical reports from Russian centres describe attention, memory and recovery scores in patients after stroke or transient ischemic attack. Most of those human studies are small and few have been repeated by independent groups. Outcome measures differ between studies, which limits direct comparison.
| Property | Value | Notes |
|---|---|---|
| Primary research models | Rodent studies | Largest share of published data |
| Reported markers | BDNF and NGF expression | Measured mainly in animal tissue |
| Common administration | Intranasal | Matches the registered formulation |
| Blood residence time | Minutes | Rapid enzymatic degradation |
| Evidence quality | Small trials, limited replication | Noted repeatedly in reviews |
Claims about enhanced focus, memory, or mood in healthy people rest mostly on anecdotal reports and community discussion rather than on controlled data. It remains unclear whether any cognitive benefit observed in patients recovering from brain injury would extend to uninjured users. Dose-response relationships, long-term safety, and interactions with other drugs are not well characterized in the peer-reviewed literature. Questions about optimal route of administration and treatment duration likewise remain open.
Semax binds to melanocortin receptors and is thought to influence neuronal survival and plasticity rather than to act through the adrenal axis. Laboratory work has shown increased expression of brain-derived neurotrophic factor and nerve growth factor in treated tissue. Changes in c-Fos, a marker of neuronal activation, have also been reported. Because the peptide is rapidly degraded by peptidases, its effects are generally attributed to downstream signaling cascades rather than to sustained receptor occupancy.
Abietic acid dermatitis Acid-induced Acrylic monomer dermatitis Adhesive dermatitis African blackwood dermatitis Airbag dermatitis (airbag burn) Alkali-induced Allergic Antifungal agent-induced Antimicrobial agent-induced Arsenic dermatitis Artificial nail-induced Axillary antiperspirant-induced Axillary deodorant-induced Baboon syndrome Black dermatographism Bleaching cream-induced Capsaisin-induced Chemical burn Chloracne Chrome dermatitis Clothing-induced Cobalt dermatitis Contact stomatitis (contact lichenoid reaction, lichenoid amalgam reaction, oral mucosal cinnamon reaction) Contact urticaria Corticosteroid-induced Cosmetic dermatitis Cosmetic intolerance syndrome Dentifrice-induced Dermatitis from metals and metal salts Dust-induced Epoxy resin dermatitis Ethylenediamine-induced Eye makeup-induced Fiberglass dermatitis Flower-induced Formaldehyde-induced Formaldehyde-releasing agent-induced Fragrance-induced Gold dermatitis Hair bleach-induced Hair dye-induced Hair lotion-induced Hair spray-induced Hair straightener-induced Hair tonic-induced Houseplant-induced Hydrocarbon-induced Irritant folliculitis Lacquer dermatitis (lacquer sensitivity) Lanolin-induced Lipstick-induced Local anesthetic-induced Makassar ebony dermatitis Marine plant-induced Mechanical irritant dermatitis Mercury dermatitis Mouthwash-induced Nail lacquer-induced Nail polish remover-induced Nickel dermatitis Occupation-induced p-Chloro-meta-xylenol-induced Paraben-induced Paraphenylenediamine dermatitis Permanent wave preparation-induced Phenothiazine drug-induced Photoallergic Photoirritant Plant derivative-induced Pollen-induced Polyester resin dermatitis Propylene glycol-induced Protein contact dermatitis Quaternium-15 hypersensitivity Reed dermatitis Rosewood dermatitis Rosin dermatitis Rubber dermatitis Seed-induced Shoe dermatitis Solvent-induced Sorbic acid-induced Subjective irritant contact dermatitis (sensory irritant contact dermatitis) Sunscreen-induced Systemic contact dermatitis Tear gas dermatitis Textile dermatitis Traumatic irritant contact dermatitis Tree-associated plant-induced Tree-induced Tulip fingers Urushiol-induced Vegetable-induced
=== Size and hands === A study investigating the relationship with digit ratio and found men with longer ring fingers than index fingers had longer penises, and it was the only significant predictor of both stretched and erect penis length. However, the common misconception that overall hand size predicts penis size has been widely discredited.
Isotretinoin, also known as 13-cis-retinoic acid and sold under the brand name Accutane among others, is a medication used to treat skin diseases like harlequin-type ichthyosis, lamellar ichthyosis, and severe cystic acne or moderate acne that is unresponsive to antibiotics. Isotretinoin is used off-label to treat basal cell carcinoma and squamous cell carcinoma, although clinical evidence suggests it is not effective in this setting. It is a retinoid, meaning it is related to vitamin A, and is found in small quantities naturally in the body. Its isomer, tretinoin, is also an acne drug. In its pure form, isotretinoin is an orange powder. The most common adverse effects are dry lips (cheilitis), dry and fragile skin (xeroderma), dry eyes and an increased susceptibility to sunburn. Uncommon and rare side effects include muscle aches and pains (myalgias), headaches, and depression in some users. Some of those side effects can persist long after the discontinuation of the use of the drug. Isotretinoin may cause liver failure, therefore the patient's blood levels should be regularly tested. It is known to cause birth defects due to in-utero exposure because of the molecule's close resemblance to retinoic acid, a natural vitamin A derivative that controls normal embryonic development. It is associated with psychiatric side effects, most commonly depression, and more rarely, psychosis and unusual behaviors. Other rare side effects include hyperostosis and premature epiphyseal closure, which have been reported to be persistent.
Graphite oxide (GO), formerly called graphitic oxide or graphitic acid, is a compound of carbon, oxygen, and hydrogen in variable ratios, obtained by treating graphite with strong oxidizers and acids for resolving of extra metals. The maximally oxidized bulk product is a yellow solid with C:O ratio between 2.1 and 2.9, that retains the layer structure of graphite but with a much larger and irregular spacing. The bulk material spontaneously disperses in basic solutions or can be dispersed by sonication in polar solvents to yield monomolecular sheets, known as graphene oxide by analogy to graphene, the single-layer form of graphite. Graphene oxide sheets have been used to prepare strong paper-like materials, membranes, thin films, and composite materials. Initially, graphene oxide attracted substantial interest as a possible intermediate for the manufacture of graphene. The graphene obtained by reduction of graphene oxide still has many chemical and structural defects which is a problem for some applications but an advantage for some others.
== Features == Under CRDD, numerous resources related to computer-aided drug design have been collected and compiled. These resources are organized and presented on CRDD so users may locate resources from a single source.
Sources: en.wikipedia.org
The Arbrans inaugurate a second "Reconstitution", revising many of the rules that had restricted the work and lifestyle of the avout. Erasmas and his friends begin to build a new concent, open to the outside world and dedicated to Saunt Orolo.
In the 13th and 14th centuries, some pilgrims to Canterbury journeyed via Billericay. Some of them may have spent the night in the town before crossing the river Thames at Tilbury; this may account for the large number of inns. The town's most notable historical episode was the Battle of Billericay during the Peasants' Revolt of 1381.
=== Other antibiotics === Alternatives to fosfomycin include nitrofurantoin, pivmecillinam, and co-amoxiclav in oral treatment of urinary-tract infections associated with extended-spectrum beta-lactamase. In a separate study, CRE were treated with colistin, amikacin, and tigecycline, and emphasizes the importance of using gentamicin in patients undergoing chemotherapy or stem-cell therapy procedures. While colistin had shown promising activity against carbapenemase-producing isolates, more recent data suggest a resistance to it is already emerging and it will soon become ineffective. Using another antibiotic concomitantly with carbapenem can help prevent the development of carbapenem resistance. One specific study showed a higher rate of carbapenem resistance when using meropenem alone compared with combination therapy with moxifloxacin. In addition, several drugs were tested to gauge their effectiveness against CRE infections. In vitro studies have shown that rifampin has synergistic activity against carbapenem-resistant E. coli and K. pneumoniae. However, more data are needed to determine if rifampin is effective in a clinical setting. Several new agents are in development. The main areas where scientists are focusing is new β-lactamase inhibitors with activity against carbapenemases. Some of these include MK-7655, NXL104, and 6-alkylidenepenam sulfones. The exact way they affect the carbapenemases is unknown. Another experimental agent with activity against CRE is eravacycline.
== German Empire (1871–1918) == The German Empire was born out of the North German Confederation as result of the Franco-Prussian War (1870/71). The Präsidium (the Prussian king), which now had also the title Emperor, named the chancellor. Political parties: None Centre
== S == Sac6 Sla1p Srv2 (CAP) S-adenosyl-L-homocysteine hydrolase, (SAHH) Sla2p Synaptopodin Scinderin (adseverin) Synapsins Scruin Spectrin Severin Spectraplakins SVSII Shot (Short stop) Spire Shroom Smitin (Smooth Musc.Titin) Supervillin SipA Smoothelin Sucrose synthetase SipC Sra-1 Spinophilin Ssk2p Swinholide
Sources: en.wikipedia.org
=== Numbers of new drugs === Under the ODA and EU legislation, many orphan drugs have been developed, including drugs to treat glioma, multiple myeloma, cystic fibrosis, phenylketonuria, snake venom poisoning, and idiopathic thrombocytopenic purpura. The Pharmaceutical Executive opines that the "ODA is nearly universally acknowledged to be a success". Before the US Congress enacted the ODA in 1983, only 38 drugs were approved in the US specifically to treat orphan diseases. In the US, from January 1983 to June 2004, 249 orphan drugs received marketing authorization and 1,129 received different orphan drug designations, compared to fewer than ten such products in the decade prior to 1983. From 1983 until May 2010, the FDA approved 353 orphan drugs and granted orphan designations to 2,116 compounds. As of 2010, 200 of the roughly 7,000 officially designated orphan diseases have become treatable. Critics have questioned whether orphan drug legislation was the real cause of this increase, claiming that many of the new drugs were for disorders which were already being researched anyway, and would have had drugs developed regardless of the legislation, and whether the ODA has truly stimulated the production of non-profitable drugs; the act also has been criticised for allowing some pharmaceutical companies to make a large profit off drugs which have a small market but sell for a high price.
== Isotopic abundance == The monoisotopic peak is sometimes not observable for two primary reasons. First, the monoisotopic peak may not be resolved from the other isotopic peaks. In this case, only the average molecular mass may be observed. In some cases, even when the isotopic peaks are resolved, such as with a high-resolution mass spectrometer, the monoisotopic peak may be below the noise level and higher isotopes may dominate completely. If a piece of iron was put into a mass spectrometer to be analyzed, the mass spectra of iron (Fe) would result in multiple mass spectral peaks due to the existence of the iron isotopes, 54Fe, 56Fe, 57Fe, 58Fe. The mass spectrum of Fe represents that the monoisotopic mass is not always the most abundant isotopic peak in a spectrum despite it containing the most abundant isotope for each atom. This is because as the number of atoms in a molecule increases, the probability that the molecule contains at least one heavy isotope atom also increases. If there are 100 carbon atoms 12C in a molecule, and each carbon has a probability of approximately 1% of being a heavy isotope 13C, the whole molecule is highly likely to contain at least one heavy isotope atom of carbon-13 and the most abundant isotopic composition will no longer be the same as the monoisotopic peak.
He headed the School of Pharmacy at Manchester on two occasions, 1988-1991 and 1998-2001, periods involving the move to clinical pharmacy and moving Pharmacy from the Faculty of Science and Engineering to the Faculty of Medicine, in recognition of the changing professional role of pharmacists from fabricator to health care advisor on medicines. Rowland has trained 90 Ph.D. students and scientists from a variety of disciplines. He also established ongoing annual postgraduate workshops in basic pharmacokinetics with Tomas Tozer (1977), and in advanced methods in pharmacokinetics and pharmacodynamics with Lewis Sheiner (1981). Rowland was president of EUFEPS (European Federation for Pharmaceutical Sciences, 1996-1999), and a Vice-President of FIP (International Pharmaceutical Federation, 2001-2009).
== Research == Bifidobacterium animalis subspecies lactis BB-12 administered in combination with other probiotics has shown "a trend toward increased remission" in a study of 32 patients with ulcerative colitis. Research on Bifidobacterium animalis supplementation in preterm infants, as detailed in the systematic review by Szajewska et al., a meta-analysis of four randomized controlled trials (RCTs) involving a total of 324 infants, has shown promising results. These include increased fecal bifidobacteria counts, reduced Enterobacteriaceae and Clostridium spp counts, as well as improvements in stool pH, fecal calprotectin concentrations, fecal immunoglobulin A levels, and short-chain fatty acid concentrations. However, the analysis did not find significant effects on the risk of necrotizing enterocolitis stage ≥2, risk of sepsis, or use of antibiotics compared to controls.
=== CNO-I === The first proposed catalytic cycle for the conversion of hydrogen into helium was initially called the carbon–nitrogen cycle (CN-cycle), also referred to as the Bethe–Weizsäcker cycle in honor of the independent work of Carl Friedrich von Weizsäcker in 1937–38 and Hans Bethe. Bethe's 1939 papers on the CN-cycle drew on three earlier papers written in collaboration with Robert Bacher and Milton Stanley Livingston and which came to be known informally as Bethe's Bible. It was considered the standard work on nuclear physics for many years and was a significant factor in his being awarded the 1967 Nobel Prize in Physics. Bethe's original calculations suggested the CN-cycle was the Sun's primary source of energy. This conclusion arose from a belief that is now known to be mistaken, that the abundance of nitrogen in the sun is approximately 10%; it is actually less than half a percent. The CN-cycle, named as it contains no stable isotope of oxygen, involves the following cycle of transformations:
Sources: en.wikipedia.org
The main proposal is modulation of neurotrophic factors such as brain-derived neurotrophic factor, supported largely by animal experiments. Receptor-level targets have not been firmly established. Most reviews describe the mechanism as only partially characterized.
The compound is registered as a medicine in Russia, so clinical work has concentrated there. Trials elsewhere are few and generally small. This geographic concentration is a recognized limitation in evidence reviews.
Some fraction may reach the central nervous system through olfactory pathways, and this is often cited as the rationale for the nasal route. The size of that fraction in humans is not well quantified. Blood concentrations after nasal dosing are low, which complicates measurement.
It consists mainly of animal experiments and small clinical reports, with much of the clinical material published in Russian-language journals. Large independent trials are scarce. Separating reliable effects from chance findings is consequently difficult.