Important Protective Properties Research Articles

Melatonin in the regulation of human life and its role in development pathology

The aim of our study was to research the literature data available for analysis of the melatonin role in the neurological and mental disorders origin. Materials and methods: to compile a literature review by keywords, articles there were selected and analyzed in the MEDLINE / PubMed and e-library databases from 1993 to 2021. For a detailed analysis, 42 literature sources were selected for the melatonin role in the development of neurological and mental disorders. Results: Melatonin is a hormone with unique adaptive capabilities. Violation of its production, both quantitatively and its rhythm, is the starting point, leading at the initial stages to desynchronizes, followed by the emergence of organic pathology. Consequently, the very fact of a violation of melatonin production can be the cause of various diseases. It was found that the volume of the pineal gland can change with the development of various types of neurological and psychiatric diseases, which is associated with a violation of the synthesis of melatonin and serotonin. Melatonin has been found to have important protective properties in Alzheimer's disease - the ability to inhibit the formation of beta-amyloid peptide in the brain, which is the morphological basis of this disease. The same correlation was found in patients with autism, psychosis and obsessive-compulsive disorder compared with healthy volunteers. Regarding the neuroprotective properties of melatonin, it should be noted its effectiveness in age-related diseases (Alzheimer's, Parkinson's, vascular diseases) Conclusion: Melatonin can be considered as a unique bioregulator, adaptogen and stabilizer of the whole organism and, in particular, the functions of the central nervous system. It has been proven that disruption of melatonin metabolism leads to various neurological and mental disorders.

Polyglycerol-Based Mucus-Inspired Hydrogels.

The mucus layer is a hydrogel network that covers mucosal surfaces of the human body. Mucus has important protective properties that are related to its unique rheological properties, which are based on mucins being the main glycoprotein constituents. Mucin macromolecules entangle with one another and form a physical network that is instrumental for many important defense functions. Mucus derived from various human or animal sources is poorly defined and thus not suitable for many application purposes. Herein, a synthetic route is fabricated to afford a library of compositionally defined mucus-inspired hydrogels (MIHs). MIHs are synthesized by thiol oxidation to render disulfide bonds between the crosslinker ethoxylated trimethylolpropane tri(3-mercaptopropionate) (THIOCURE ETTMP 1300) and the linear precursors, dithiolated linear polyglycerol (LPG(SH)2 ) or polyethylene glycol (PEG(SH)2 ) of different molecular weights. The mixing ratio of linear polymers versus crosslinker and the length of the linear polymer are varied, thus delivering a library of compositionally defined mucin-inspired constructs. Their viscoelastic properties are determined by frequency sweeps at 25 and 37 °C and compared to the corresponding behavior of native human mucus. Here, MIHs composed of a 10:1 ratio of LPG(SH)2 and ETTMP 1300 are proved to be the best comparable to human airway mucus rheology.

Natural Food Supplements Reduce Oxidative Stress in Primary Neurons and in the Mouse Brain, Suggesting Applications in the Prevention of Neurodegenerative Diseases.

Neurodegenerative diseases pose a major health problem for developed countries, and stress has been identified as one of the main risk factors in the development of these disorders. Here, we have examined the protective properties against oxidative stress of several bioactive natural food supplements. We found that MecobalActive®, Olews®, and red and white grape seed polyphenol extracts may have a neuroprotective effect in vitro, both in the SH-SY 5Y cell line and in hippocampal neuron cultures, mainly by reducing reactive oxygen species levels and decreasing caspase-3 activity. In vivo, we demonstrated that oral administration of the supplements reduces the expression of genes involved in inflammation and oxidation mechanisms, whereas it increments the expression of genes related to protection against oxidative stress. Furthermore, we found that preventive treatment with these natural extracts increases the activity of antioxidant enzymes and prevents lipid peroxidation in the brain of stressed mice. Thus, our results indicate that some natural bioactive supplements may have important protective properties against oxidative stress processes occurring in the brain.

Impact of Repeated Exposure and Cleaning on Protective Properties of Structural Firefighting Turnout Gear

The US fire service has become acutely aware of the need to clean PPE after fires. However, there is concern that damage from repeated cleaning may impact critical protection from fireground risk. Using a protocol that included repeated simulated fireground exposures (between 0 cycles and 40 cycles) and/or repeated cleaning with techniques common in the fire service, we found that several important protective properties of NFPA 1971 compliant turnout gear are significantly changed. Outer shell and thermal liner tear strength showed a statistically significant reduction when laundered as compared to wet or dry decontamination. Larger changes in outer shell tear strength resulted when the coat closure incorporated hook & dee clasps as compared with garments using zippered closures. Total Heat Loss was reduced for all samples that underwent any form of cleaning while Thermal Protective Performance was only increased in the gear that was laundered. These results suggest that some important protective properties of bunker gear can be decreased after repeated exposure/cleaning cycles relative to their levels when tested in a new condition. For the specific materials tested, outer shell trap tear strength in the fill direction and seam strength dropped below NFPA 1971 requirements after 40 laundering cycles. The findings for this study may have utility for setting preconditions for the measurement of certain performance properties in future editions of NFPA 1971.

Mapping Epitopes of a Novel Peptidoglycan Cross-Linking Enzyme Cwp22 Recognized by Human Sera Obtained from Patients with Clostridioides difficile Infection and Cord Blood.

Clostridioides difficile (CD) cause a severe diarrhea which can lead to pseudomembranous colitis and even patient death. CD infection (CDI) is connected mainly with changes in intestinal microbiota as a consequence of antibiotic treatment. The growing resistance to antibiotics, justifies the search for new methods of combating CD. Despite of ongoing research on the immunity against the pathogen, there is still lack of any reliable vaccine. Most recently, Cwp22, that is a cross-linking enzyme involved in the production of CD peptidoglycan, seems to be a promising target to prevent CDI in high-risk patients. In this paper, the Cwp22 protein polypeptide-specific epitopes were mapped in silico and using PEPSCAN procedure. They were recognized not only by antibodies from CDI patients’ but also by umbilical cord blood sera. We identified three epitopes 54EFRVAT59, 201KVNGKM206 and 268WQEKNGKKYY277 of Cwp22 protein. Since Cwp22 protein has key functionality and the described above epitopes are also recognized by umbilical cord blood serum, we postulate that they could have important protective properties. In this paper, we propose Cwp22 protein as a good antigen candidate for CDI preventive vaccine. Our results open the possibility to use 54EFRVAT59, 201KVNGKM206 and 268WQEKNGKKYY277, epitopes as suitable anti-CD vaccine antigens.

Resolution of Parenteral Nutrition–associated Jaundice on Changing From a Soybean Oil Emulsion to a Complex Mixed‐Lipid Emulsion

Resolution of parenteral nutrition (PN)-associated jaundice has been reported in children given a reduced dose of intravenous fat using a fish oil-derived lipid emulsion. The aim of the present study was to examine the effect on PN-associated jaundice of changing from a soybean oil-derived lipid to a mixed lipid emulsion derived from soybean, coconut, olive, and fish oils without reducing the total amount of lipid given. Retrospective cohort comparison examining serum bilirubin during 6 months in children with PN-associated jaundice who changed to SMOFlipid (n=8) or remained on Intralipid (n=9). At entry, both groups received most of their energy as PN (SMOFlipid 81.5%, range 65.5-100 vs Intralipid 92.2%, range 60.3-100; P=0.37). After 6 months, both tolerated increased enteral feeding but still received large proportions of their energy as PN (SMOFlipid 68.4%, range 36.6-100 vs Intralipid 50%, range 37.6-76; P=0.15). The median bilirubin at the outset was 143 μmol/L (range 71-275) in the SMOFlipid group and 91 μmol/L (range 78-176) in the Intralipid group. After 6 months, 5 of 8 children in the SMOFlipid and 2 of 9 children in the Intralipid group had total resolution of jaundice. The median bilirubin fell by 99 μmol/L in the SMOFlipid group but increased by 79 μmol/L in the Intralipid group (P=0.02). SMOFlipid may have important protective properties for the liver and may constitute a significant advance in PN formulation. Randomised trials are needed to study the efficacy of SMOFlipid in preventing PN liver disease.

Bioactivation of 7-hydroxymethyl-12-methylbenz[a]anthracene by rat liver bile acid sulfotransferase I.

The bioactivation of 7-hydroxymethyl-12-methylbenz[a]anthracene (HMBA) to an electrophilic sulfuric acid ester metabolite has been shown to be catalyzed by rat liver bile acid sulfotransferase I (BAST I). The sulfation and activation of HMBA by BAST I was determined by the ability of sulfated HMBA to form DNA adducts. The BAST I was also shown to react with rabbit anti-human dehydroepiandrosterone sulfotransferase antisera and to represent a major form of hydroxysteroid/bile acid sulfotransferase in female rat liver cytosol. Higher levels of BAST I activity and immunoreactivity as well as HMBA-DNA adduct formation were detected in female rat liver cytosol than in male rat liver cytosol. The bioactivation of HMBA by pure BAST I was dependent on the presence of 3'-phosphoadenosine 5'-phosphosulfate (PAPS) in the reaction and was inhibited by dehydroepiandrosterone, a physiological substrate for BAST I. Glutathione, a cellular nucleophile with important protective properties, decreased DNA adduct formation in the HMBA sulfation reaction in the absence of glutathione S-transferase activity. These results indicate the usefulness of BAST I to investigate the sulfation and activation of HMBA and probably other hydroxymethylated polyaromatic hydrocarbons to electrophilic and mutagenic metabolites under defined reaction conditions.