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RSC Advances May 2024The current investigation centers on elucidating the intricate molecular architecture and dynamic behavior of four macrolide antibiotics, specifically erythromycin,...
The current investigation centers on elucidating the intricate molecular architecture and dynamic behavior of four macrolide antibiotics, specifically erythromycin, clarithromycin, azithromycin, and roxithromycin, through the application of sophisticated solid-state nuclear magnetic resonance (SSNMR) methodologies. We have measured the principal components of chemical shift anisotropy (CSA) parameters, and the site-specific spin-lattice relaxation time at carbon nuclei sites. To extract the principal components of CSA parameters, we have employed C 2DPASS CP-MAS SSNMR experiments at two different values of magic angle spinning (MAS) frequencies, namely 2 kHz and 600 Hz. Additionally, the spatial correlation between C and H nuclei has been investigated using H-C frequency switched Lee-Goldburg heteronuclear correlation (FSLGHETCOR) experiment at a MAS frequency of 24 kHz. Our findings demonstrate that the incorporation of diverse functional groups, such as the ketone group and oxime group with the lactone ring, exerts notable influences on the structure and dynamics of the macrolide antibiotic. In particular, we have observed a significant decrease in the spin-lattice relaxation time of carbon nuclei residing on the lactone ring, desosamine, and cladinose in roxithromycin, compared to erythromycin. Overall, our findings provide detailed insight into the relationship between the structure and dynamics of macrolide antibiotics, which is eventually correlated with their biological activity. This knowledge can be utilized to develop new and more effective drugs by providing a rational basis for drug discovery and design.
PubMed: 38832242
DOI: 10.1039/d4ra00718b -
Translational Psychiatry Jun 2024Prior regional Cerebral Blood Flow (rCBF) studies in Major Depressive Disorder (MDD) have been limited by small, highly selective, non-representative samples that have...
Prior regional Cerebral Blood Flow (rCBF) studies in Major Depressive Disorder (MDD) have been limited by small, highly selective, non-representative samples that have yielded variable and poorly replicated findings. The aim of this study was to compare rCBF measures in a large, more representative community sample of adults with MDD and healthy control participants. This is a cross-sectional, retrospective multi-site cohort study in which clinical data from 338 patients 18-65 years of age with a primary diagnosis of MDD were retrieved from a central database for 8 privately owned, private-pay outpatient psychiatric centers across the United States. Two Tc-HMPAO SPECT brain scans, one at rest and one during performance of a continuous performance task, were acquired as a routine component of their initial clinical evaluation. In total, 103 healthy controls, 18-65 years old and recruited from the community were also assessed and scanned. Depressed patients had significantly higher rCBF in frontal, anterior cingulate, and association cortices, and in basal ganglia, thalamus, and cerebellum, after accounting for significantly higher overall CBF. Depression severity associated positively with rCBF in the basal ganglia, hippocampus, cerebellum, and posterior white matter. Elevated rCBF was especially prominent in women and older patients. Elevated rCBF likely represents pathogenic hypermetabolism in MDD, with its magnitude in direct proportion to depression severity. It is brain-wide, with disproportionate increases in cortical and subcortical attentional networks. Hypermetabolism may be a reasonable target for novel therapeutics in MDD.
Topics: Humans; Depressive Disorder, Major; Adult; Female; Male; Middle Aged; Cerebrovascular Circulation; Cross-Sectional Studies; Tomography, Emission-Computed, Single-Photon; Young Adult; Retrospective Studies; Adolescent; Technetium Tc 99m Exametazime; Brain; Aged; Radiopharmaceuticals
PubMed: 38830866
DOI: 10.1038/s41398-024-02961-5 -
EFSA Journal. European Food Safety... May 2024The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of amines, di-C14-C18-alkyl, oxidised, renamed by the Panel as amines,...
The EFSA Panel on Food Contact Materials, Enzymes and Processing Aids (CEP) assessed the safety of amines, di-C14-C18-alkyl, oxidised, renamed by the Panel as amines, di-C14-C20-alkyl, oxidised, from hydrogenated vegetable oil. The substance amines, bis(hydrogenated tallow alkyl) oxidised, consisting of the same components, but originating from tallow, is currently authorised as FCM substance No 768. The vegetable-sourced substance is intended to be used at up to 0.1% w/w as antioxidant and/or stabiliser in the manufacture of polyolefin food contact materials (FCM) and articles intended for contact with dry, aqueous and acidic foods. The substance is a mixture consisting of linear N,N-dialkyl hydroxylamines and their corresponding amine, nitrone and oxime derivatives, as well as further components: tert-N-oxides, secondary amides and carboxylic acids. Specific migration was tested from polyethylene samples in 10% ethanol and 3% acetic acid for 2 h at 100°C followed by 10 days at 60°C. None of the non-authorised components were detected to migrate at detection limits (LoD) in the range 0.003-0.029 mg/kg. The LoD of authorised carboxylic acids was 0.35 mg/kg. The Panel reassessed the genotoxicity studies carried out on FCM No 768 and evaluated two new bacterial reverse mutation tests on the nitrone and oxime derivatives as well as new (qualitative/quantitative) structure-activity relationship (Q)SAR analyses on other components. The Panel concluded that the substance did not raise a concern for genotoxicity. The Panel concluded that the substance is not of safety concern for the consumers if it is used as an additive at 0.1% w/w in the manufacture of polyolefin FCM intended to be in contact with foods simulated by food simulants A, B, C and E, except for infant formula and human milk, for storage above 6 months at room temperature and below, including hot-fill conditions and heating up to 100°C for 2 h.
PubMed: 38799480
DOI: 10.2903/j.efsa.2024.8769 -
International Journal For Parasitology.... May 2024Heartworm disease caused by the nematode Dirofilaria immitis is one of the most important parasitoses of dogs. The treatment of the infection is long, complicated, risky...
Heartworm disease caused by the nematode Dirofilaria immitis is one of the most important parasitoses of dogs. The treatment of the infection is long, complicated, risky and expensive. Conversely, prevention is easy, safe, and effective and it is achieved by the administration of macrocyclic lactones (MLs). In recent years, D. immitis strains resistant to MLs have been described in Southern USA, raising concerns for possible emergence, or spreading in other areas of the world. The present study describes the first case of ML-resistant D. immitis in a dog in Europe. The dog arrived in Rome, Italy, from USA in 2023. Less than 6 months after its arrival in Italy, the dog tested positive for D. immitis circulating antigen and microfilariae, despite it having received monthly the ML milbemycin oxime (plus an isoxazoline) after arrival. The microfilariae suppression test suggested a resistant strain. Microfilariae DNA was examined by droplet digital PCR-based duplex assays targeting four marker positions at single nucleotide polymorphisms (SNP1, SNP2, SNP3, SNP7) which differentiate resistant from susceptible isolates. The genetic analysis showed that microfilariae had a ML-resistant genotype at SNP1 and SNP7 positions, compatible with a resistant strain. It is unlikely that the dog acquired the infection after its arrival in Europe, while it is biologically and epidemiologically plausible that the dog was already infected when imported from USA to Europe. The present report highlights the realistic risk of ML-resistant D. immitis strains being imported and possibly transmitted in Europe and other areas of the world. Monitoring dogs travelling from one area to another, especially if they originate from regions where ML-resistance is well-documented, is imperative. Scientists, practitioners, and pet owners should be aware of the risk and remain vigilant against ML-resistance, in order to monitor and reduce the spreading of resistant D. immitis.
PubMed: 38795510
DOI: 10.1016/j.ijpddr.2024.100549 -
Journal of Clinical Medicine May 2024: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and...
: Since metabolic diseases and atherosclerotic vascular events are firmly associated, herein we investigate changes in central microcirculation and atherosclerosis-related body fat distribution in patients with type 2 diabetes mellitus and obesity. Resting brain perfusion single-photon emission computed tomography (SPECT) imaging with Technetium-99m hexamethylpropylene amine oxime ([Tc]Tc-HMPAO SPECT) was performed, and the breath-holding index (BHI) and carotid intima-media thickness (cIMT) were measured to characterise central microcirculation. Besides CT-based abdominal fat tissue segmentation, C-peptide level, glycaemic and anthropometric parameters were registered to search for correlations with cerebral blood flow and vasoreactivity. : Although no significant difference was found between the resting cerebral perfusion of the two patient cohorts, a greater blood flow increase was experienced in the obese after the breath-holding test than in the diabetics ( < 0.05). A significant positive correlation was encountered between resting and provocation-triggered brain perfusion and C-peptide levels ( < 0.005). BMI and cIMT were negatively correlated (rho = -0.27 and -0.23 for maximum and mean cIMT, respectively), while BMI and BHI showed a positive association (rho = 0.31 and rho = 0.29 for maximum and mean BHI, respectively), which could be explained by BMI-dependent changes in fat tissue distribution. cIMT demonstrated a disproportional relationship with increasing age, and higher cIMT values were observed for the men. Overall, C-peptide levels and circulatory parameters seem to be strong applicants to predict brain microvascular alterations and related cognitive decline in such patient populations.
PubMed: 38792441
DOI: 10.3390/jcm13102900 -
Science Advances May 2024State-of-the-art technology for cyclohexanone oxime production typically demands elevated temperature and pressure, along with the utilization of expensive hydroxylamine...
State-of-the-art technology for cyclohexanone oxime production typically demands elevated temperature and pressure, along with the utilization of expensive hydroxylamine sulfate or oxidants. Here, we propose an electrochemistry-assisted cascade strategy for the efficient cyclohexanone ammoximation under ambient conditions by using in situ cathode-generated green oxidants of reactive oxygen species (ROS) such as OOH* and HO. This electrochemical reaction can take place at the cathode, achieving over 95% yield, 99% selectivity of cyclohexanone oxime, and an electron-to-oxime (ETO) efficiency of 96%. Mechanistic analysis reveals that, in addition to the direct ammoximation by in situ-generated OOH* by electrocatalytic ORR, Ti-MOR also play a major role in capturing OOH* directly and converting the in situ-generated HO to OOH*, thus accelerating the ORR-coupled cascade production of cyclohexanone oxime. This work paves a mild, economical, and sustainable energy-efficient electrocatalytic route for the oxime production using oxygen, ammonium bicarbonate, and cyclohexanone.
PubMed: 38787946
DOI: 10.1126/sciadv.ado1755 -
Biomolecules May 2024Olesoxime, a cholesterol derivative with an oxime group, possesses the ability to cross the blood-brain barrier, and has demonstrated excellent safety and tolerability...
Olesoxime, a cholesterol derivative with an oxime group, possesses the ability to cross the blood-brain barrier, and has demonstrated excellent safety and tolerability properties in clinical research. These characteristics indicate it may serve as a centrally active ligand of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), whose disruption of activity with organophosphate compounds (OP) leads to uncontrolled excitation and potentially life-threatening symptoms. To evaluate olesoxime as a binding ligand and reactivator of human AChE and BChE, we conducted kinetic studies with the active metabolite of insecticide parathion, paraoxon, and the warfare nerve agents sarin, cyclosarin, tabun, and VX. Our results showed that both enzymes possessed a binding affinity for olesoxime in the mid-micromolar range, higher than the antidotes in use (i.e., 2-PAM, HI-6, etc.). While olesoxime showed a weak ability to reactivate AChE, cyclosarin-inhibited BChE was reactivated with an overall reactivation rate constant comparable to that of standard oxime HI-6. Moreover, in combination with the oxime 2-PAM, the reactivation maximum increased by 10-30% for cyclosarin- and sarin-inhibited BChE. Molecular modeling revealed productive interactions between olesoxime and BChE, highlighting olesoxime as a potentially BChE-targeted therapy. Moreover, it might be added to OP poisoning treatment to increase the efficacy of BChE reactivation, and its cholesterol scaffold could provide a basis for the development of novel oxime antidotes.
Topics: Humans; Butyrylcholinesterase; Acetylcholinesterase; Ligands; Oximes; Cholinesterase Reactivators; Cholinesterase Inhibitors; Cholestenones; Kinetics; Sarin; GPI-Linked Proteins; Antidotes; Cholesterol; Organophosphorus Compounds
PubMed: 38785995
DOI: 10.3390/biom14050588 -
RSC Medicinal Chemistry May 2024A simple assay involving the measurement of IL-6 production in human synovial fibroblasts from rheumatoid arthritis patients has been utilised to select candidates from...
A new class of 7-deazaguanine agents targeting autoimmune diseases: dramatic reduction of synovial fibroblast IL-6 production from human rheumatoid arthritis patients and improved performance against murine experimental autoimmune encephalomyelitis.
A simple assay involving the measurement of IL-6 production in human synovial fibroblasts from rheumatoid arthritis patients has been utilised to select candidates from a targeted library of queuine tRNA ribosyltransferase (QTRT) substrates for subsequent screening in murine experimental autoimmune encephalomyelitis (EAE - a model of multiple sclerosis). The activity assay discriminated between poor and excellent 7-deazaguanine QTRT substrates and allowed the identification of several structures which subsequently outperformed the previous lead in EAE. Two molecules were of significant promise: one rigidified analogue of the lead, and another considerably simpler structure incorporating an oxime motif which differs structurally from the lead to a considerable extent. These studies provide data from human cells for the first time and have expanded both the chemical space and current understanding of the structure-activity relationship underpinning the remarkable potential of 7-deazguanines in a Multiple Sclerosis disease model.
PubMed: 38784475
DOI: 10.1039/d4md00028e -
Cell Communication and Signaling : CCS May 2024Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance...
Extracellular vesicles (EVs) constitute a vital component of intercellular communication, exerting significant influence on metastasis formation and drug resistance mechanisms. Malignant melanoma (MM) is one of the deadliest forms of skin cancers, because of its high metastatic potential and often acquired resistance to oncotherapies. The prevalence of BRAF mutations in MM underscores the importance of BRAF-targeted therapies, such as vemurafenib and dabrafenib, alone or in combination with the MEK inhibitor, trametinib. This study aimed to elucidate the involvement of EVs in MM progression and ascertain whether EV-mediated metastasis promotion persists during single agent BRAF (vemurafenib, dabrafenib), or MEK (trametinib) and combined BRAF/MEK (dabrafenib/trametinib) inhibition.Using five pairs of syngeneic melanoma cell lines, we assessed the impact of EVs - isolated from their respective supernatants - on melanoma cell proliferation and migration. Cell viability and spheroid growth assays were employed to evaluate proliferation, while migration was analyzed through mean squared displacement (MSD) and total traveled distance (TTD) measurements derived from video microscopy and single-cell tracking.Our results indicate that while EV treatments had remarkable promoting effect on cell migration, they exerted only a modest effect on cell proliferation and spheroid growth. Notably, EVs demonstrated the ability to mitigate the inhibitory effects of BRAF inhibitors, albeit they were ineffective against a MEK inhibitor and the combination of BRAF/MEK inhibitors. In summary, our findings contribute to the understanding of the intricate role played by EVs in tumor progression, metastasis, and drug resistance in MM.
Topics: Melanoma; Extracellular Vesicles; Proto-Oncogene Proteins B-raf; Humans; Cell Movement; Cell Line, Tumor; Protein Kinase Inhibitors; Cell Proliferation; Vemurafenib; Pyrimidinones; Pyridones; Imidazoles; Oximes
PubMed: 38778340
DOI: 10.1186/s12964-024-01660-4 -
Thoracic Cancer Jun 2024Although dabrafenib plus trametinib has been approved for BRAF V600E mutation positive advanced non-small cell lung cancer (NSCLC), data on its efficacy against uncommon...
Although dabrafenib plus trametinib has been approved for BRAF V600E mutation positive advanced non-small cell lung cancer (NSCLC), data on its efficacy against uncommon BRAF mutations are still limited due to their rare frequency. We report a case of 70-year-old woman with BRAF V600_W604 deletion-insertion R-positive stage IVA lung adenocarcinoma, who was successfully treated with dabrafenib plus trametinib. Herein, we discuss the oncogenic role of uncommon BRAF mutations and highlight the importance of performing comprehensive genomic profiling on patients without any targetable gene alterations in companion diagnostics.
Topics: Humans; Pyridones; Oximes; Pyrimidinones; Proto-Oncogene Proteins B-raf; Imidazoles; Female; Aged; Carcinoma, Non-Small-Cell Lung; Lung Neoplasms; Mutation; Antineoplastic Combined Chemotherapy Protocols
PubMed: 38766698
DOI: 10.1111/1759-7714.15330