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Substance Abuse and Rehabilitation 2022Recreational gamma-hydroxybutyrate (GHB) use, although less common than other substance use, is increasingly recognised and is over-represented in emergency toxicology... (Review)
Review
Recreational gamma-hydroxybutyrate (GHB) use, although less common than other substance use, is increasingly recognised and is over-represented in emergency toxicology presentations. This narrative review summarizes GHB pharmacology, current patterns of use, potential harms and management of GHB toxicity and withdrawal. There is a complex interplay between GHB and GABA as GHB is both a prodrug and metabolite of GABA and GHB activates both GHB and GABA receptors. GHB is rapidly absorbed, with effects seen within minutes of ingestion. Metabolism is non-linear at higher doses. While GHB is listed as a controlled substance, its precursor's gamma-butyrolactone (GBL) and 1,4-butanediol (1,4-BD) are easily available as both have industrial applications. National surveys indicate low rates of GHB use, with identification of high-risk populations in men who have sex with men and polysubstance users. GHB is one of the three drugs most commonly used in chemsex. GHB is often co-ingested with other interacting psychoactive substances. Acute toxicity is dose-dependent, and management is supportive care. Withdrawal management is generally with benzodiazepines with addition of baclofen for more severe withdrawal. Barbiturates may have a role. Titration and tapering of pharmaceutical GHB is commonly used in the Netherlands. Complicated withdrawal with delirium may require intensive care and treatment with intravenous sedation. There are high rates of relapse after withdrawal and medications for longer-term management are currently being investigated. Chronic use is associated with poorer mental, physical and sexual health, social dysfunction and poor work performance. Laboratory detection is complicated as GHB is an endogenous substance with a short half-life, and therefore not often routinely assayed in the clinical setting. Future research should focus on improving GHB detection and management of GHB withdrawal and dependence. Interventions specific for high-risk groups should be developed and assessed.
PubMed: 35173515
DOI: 10.2147/SAR.S315720 -
The American Journal of Surgical... Dec 2023Compared with vulva, precursor lesions of human papillomavirus (HPV)-independent invasive squamous cell carcinoma (SCC) of the penis are insufficiently characterized. We...
Compared with vulva, precursor lesions of human papillomavirus (HPV)-independent invasive squamous cell carcinoma (SCC) of the penis are insufficiently characterized. We analyzed the histologic and immunohistochemical characteristics of 70 peritumoral precursor lesions and correlated them with the histology and mutational profile of the adjacent HPV-negative invasive penile SCC. Atypical basal keratinocyte proliferation with variously elongated epithelial rete with premature squamatiziation, but regular superficial cornification, termed differentiated penile intraepithelial neoplasia (d-PeIN), were identified adjacent to 42/70 (60%) SCC (36/42 keratinizing ( P <0.001); 3 papillary, and 1 each verrucous, clear cell, sarcomatoid SCC). d-PeIN were associated with chronic inflammatory dermatoses (32/42; P <0.001), p53 overexpression (26/42; P <0.001), and hotspot mutations in TP53 (32/42; P <0.001), CDKN2A (26/42; P <0.001) or both (21/42; P =0.003) in the adjacent SCC. Cytoplasmic p16 ink4a overexpression in 5/42 d-PeIN correlated with CDKN2A missense mutations in the adjacent SCC. In all, 21/70 (30%) cornified verrucous or glycogenated verruciform precursors with minimal atypia and wild-type p53 (18/21; P <0.001) occurred adjacent to verrucous or papillary SCC (17/21; P <0.001) and keratinizing (4/21) SCC, which harbored mutations in HRAS and/or PIK3CA (12/21; P <0.004). Undifferentiated p16 ink4a -negative full-thickness precursors were identified in 7/70 (10%) SCC. Four histologically different HPV-independent penile precursor lesions can be assigned to 2 major genetic/biological pathways with characteristic highly differentiated precursors requiring different clinical management decisions. These include d-PeIN in chronic inflammatory dermatoses, with p53 overexpression and TP53/CDKN2A mutations, and the p53 wild-type verrucous and verruciform precursors unassociated with dermatoses, but with mutations in oncogenes PIK3CA and HRAS .
Topics: Male; Female; Humans; Papillomavirus Infections; Tumor Suppressor Protein p53; Human Papillomavirus Viruses; Skin Neoplasms; Carcinoma in Situ; Carcinoma, Squamous Cell; Penile Neoplasms; Penis; Papillomaviridae; Class I Phosphatidylinositol 3-Kinases; Vulvar Neoplasms
PubMed: 37768009
DOI: 10.1097/PAS.0000000000002130 -
International Journal of Hematology Sep 2014The Ikaros family of DNA-binding proteins are critical regulators of lymphocyte differentiation. In multipotent, hematopoietic progenitors, Ikaros supports... (Review)
Review
The Ikaros family of DNA-binding proteins are critical regulators of lymphocyte differentiation. In multipotent, hematopoietic progenitors, Ikaros supports transcriptional priming of genes promoting lymphocyte differentiation. Ikaros targets the Nucleosome Remodeling Deacetylase (NuRD) complex to lymphoid lineage genes, thereby increasing chromatin accessibility and transcriptional priming. After lymphoid lineage specification, Ikaros expression is raised to levels characteristic of intermediate B cell and T cell precursors, which is necessary to support maturation and prevent leukemogenesis. Loss of Ikaros in T cell precursors allows the NuRD complex to repress lymphocyte genes and extends its targeting to genes that support growth and proliferation, causing their activation and triggering a cascade of events that leads to leukemogenesis. Loss of Ikaros in B cell precursors blocks differentiation and perpetuates stromal adhesion by enhancing integrin signaling. The combination of integrin and cytokine signaling in Ikaros-deficient pre-B cells promotes their survival and self-renewal. The stages of lymphocyte differentiation that are highly dependent on Ikaros are underscored by changes in Ikaros transcription, supported by a complex network of stage-specific regulatory networks that converge upon the Ikzf1 locus. It is increasingly apparent that understanding the regulatory networks that operate upstream and downstream of Ikaros is critical not only for our understanding of normal lymphopoiesis, but also in placing the right finger on the mechanisms that support hematopoietic malignancies in mouse and human.
Topics: Animals; Autoantigens; Cell Differentiation; Cell Lineage; Epigenesis, Genetic; Hematopoietic Stem Cells; Humans; Ikaros Transcription Factor; Lymphopoiesis; Mi-2 Nucleosome Remodeling and Deacetylase Complex; Mice; Precursor Cells, B-Lymphoid; Precursor Cells, T-Lymphoid; Protein Isoforms; Signal Transduction
PubMed: 25085254
DOI: 10.1007/s12185-014-1644-5 -
Frontiers in Bioengineering and... 2022Food is essential for human survival. Nowadays, traditional agriculture faces challenges in balancing the need of sustainable environmental development and the rising... (Review)
Review
Food is essential for human survival. Nowadays, traditional agriculture faces challenges in balancing the need of sustainable environmental development and the rising food demand caused by an increasing population. In addition, in the emerging of consumers' awareness of health related issues bring a growing trend towards novel nature-based food additives. Synthetic biology, using engineered microbial cell factories for production of various molecules, shows great advantages for generating food alternatives and additives, which not only relieve the pressure laid on tradition agriculture, but also create a new stage in healthy and sustainable food supplement. The biosynthesis of food components (protein, fats, carbohydrates or vitamins) in engineered microbial cells often involves cellular central metabolic pathways, where common precursors are processed into different proteins and products. Quantitation of the precursors provides information of the metabolic flux and intracellular metabolic state, giving guidance for precise pathway engineering. In this review, we summarized the quantitation methods for most cellular biosynthetic precursors, including energy molecules and co-factors involved in redox-reactions. It will also be useful for studies worked on pathway engineering of other microbial-derived metabolites. Finally, advantages and limitations of each method are discussed.
PubMed: 35360389
DOI: 10.3389/fbioe.2022.849177 -
Inorganic Chemistry Oct 2023Currently, two approaches dominate the large-scale production of MoS: liquid-phase exfoliation, referred to as the top-down approach, and bottom-up colloidal synthesis...
Currently, two approaches dominate the large-scale production of MoS: liquid-phase exfoliation, referred to as the top-down approach, and bottom-up colloidal synthesis from molecular precursors. Known colloidal synthesis approaches utilize toxic precursors. Here, an alternative green route for the bottom-up synthesis of MoS nanoflakes (NFs) is described. The NFs were synthesized by colloidal synthesis using [Mo(CHCOO)] and a series of sulfur (S)-precursors including thioacetamide (TAA), 3-mercaptopropionic acid (3-MPA), l-cysteine (L-CYS), mercaptosuccinic acid (MSA), 11-mercaptoundecanoic acid (MUA), 1-dodecanethiol (DDTH), and di--butyl disulfide (DTBD). While TAA, an S-precursor most commonly used for MoS NF preparation, is a known carcinogen, the other investigated S-precursors have low or no known toxicity. High-resolution scanning transmission electron microscopy (HR-STEM) and grazing incidence wide-angle X-ray scattering (GIWAXS) confirmed that in all cases, the syntheses yielded single-layer MoS NFs with lateral sizes smaller than 15 nm and a well-defined crystal structure. Electronic absorption and Raman spectra showed characteristic features associated with the MoS monolayers. The evolution of the absorption spectra of the growth solution during the syntheses reveals how the kinetics of the NF formation is affected by the S-precursor as well as the nature of the coordinating ligands.
PubMed: 37751900
DOI: 10.1021/acs.inorgchem.3c02420 -
Frontiers in Aging Neuroscience 2023Dementias and mild cognitive impairment (MCI) are associated with variously combined changes in the neurotransmitter system and signaling, from neurotransmitter...
Several dementia subtypes and mild cognitive impairment share brain reduction of neurotransmitter precursor amino acids, impaired energy metabolism, and lipid hyperoxidation.
OBJECTIVE
Dementias and mild cognitive impairment (MCI) are associated with variously combined changes in the neurotransmitter system and signaling, from neurotransmitter synthesis to synaptic binding. The study tested the hypothesis that different dementia subtypes and MCI may share similar reductions of brain availability in amino acid precursors (AAPs) of neurotransmitter synthesis and concomitant similar impairment in energy production and increase of oxidative stress, i.e., two important metabolic alterations that impact neurotransmission.
MATERIALS AND METHODS
Sixty-five demented patients (Alzheimer's disease, AD, = 44; frontotemporal disease, FTD, = 13; vascular disease, VaD, = 8), 10 subjects with MCI and 15 control subjects (CTRL) were recruited for this study. Cerebrospinal fluid (CSF) and plasma levels of AAPs, energy substrates (lactate, pyruvate), and an oxidative stress marker (malondialdehyde, MDA) were measured in all participants.
RESULTS
Demented patients and subjects with MCI were similar for age, anthropometric parameters, biohumoral variables, insulin resistance (HOMA index model), and CSF neuropathology markers. Compared to age-matched CTRL, both demented patients and MCI subjects showed low CSF AAP tyrosine (precursor of dopamine and catecholamines), tryptophan (precursor of serotonin), methionine (precursor of acetylcholine) limited to AD and FTD, and phenylalanine (an essential amino acid largely used for protein synthesis) ( = 0.03 to <0.0001). No significant differences were found among dementia subtypes or between each dementia subtype and MCI subjects. In addition, demented patients and MCI subjects, compared to CTRL, had similar increases in CSF and plasma levels of pyruvate (CSF: = 0.023 to <0.0001; plasma: < 0.002 to <0.0001) and MDA (CSF: < 0.035 to 0.002; plasma: < 0.0001). Only in AD patients was the CSF level of lactate higher than in CTRL ( = 0.003). Lactate/pyruvate ratios were lower in all experimental groups than in CTRL.
CONCLUSION
AD, FTD, and VaD dementia patients and MCI subjects may share similar deficits in AAPs, partly in energy substrates, and similar increases in oxidative stress. These metabolic alterations may be due to AAP overconsumption following high brain protein turnover (leading to phenylalanine reductions), altered mitochondrial structure and function, and an excess of free radical production. All these metabolic alterations may have a negative impact on synaptic plasticity and activity.
PubMed: 37655338
DOI: 10.3389/fnagi.2023.1237469 -
Biochemical and Biophysical Research... Apr 2024Nicotinamide adenine dinucleotide (NAD) is the fundamental molecule that performs numerous biological reactions and is crucial for maintaining cellular homeostasis.... (Review)
Review
Nicotinamide adenine dinucleotide (NAD) is the fundamental molecule that performs numerous biological reactions and is crucial for maintaining cellular homeostasis. Studies have found that NAD decreases with age in certain tissues, and age-related NAD depletion affects physiological functions and contributes to various aging-related diseases. Supplementation of NAD precursor significantly elevates NAD levels in murine tissues, effectively mitigates metabolic syndrome, enhances cardiovascular health, protects against neurodegeneration, and boosts muscular strength. Despite the versatile therapeutic functions of NAD in animal studies, the efficacy of NAD precursors in clinical studies have been limited compared with that in the pre-clinical study. Clinical studies have demonstrated that NAD precursor treatment efficiently increases NAD levels in various tissues, though their clinical proficiency is insufficient to ameliorate the diseases. However, the latest studies regarding NAD precursors and their metabolism highlight the significant role of gut microbiota. The studies found that orally administered NAD intermediates interact with the gut microbiome. These findings provide compelling evidence for future trials to further explore the involvement of gut microbiota in NAD metabolism. Also, the reduced form of NAD precursor shows their potential to raise NAD, though preclinical studies have yet to discover their efficacy. This review sheds light on NAD therapeutic efficiency in preclinical and clinical studies and the effect of the gut microbiota on NAD metabolism.
Topics: Mice; Animals; NAD; Dietary Supplements; Aging; Niacinamide; Nicotinamide Mononucleotide
PubMed: 38340651
DOI: 10.1016/j.bbrc.2024.149590 -
ACS Omega Mar 2021Organoselenium compounds with perspective application as Se precursors for atomic layer deposition have been reviewed. The originally limited portfolio of available Se... (Review)
Review
Organoselenium compounds with perspective application as Se precursors for atomic layer deposition have been reviewed. The originally limited portfolio of available Se precursors such as HSe and diethyl(di)selenide has recently been extended by bis(trialkylsilyl)selenides, bis(trialkylstannyl)selenides, cyclic selenides, and tetrakis(,-dimethyldithiocarbamate)selenium. Their structural aspects, property tuning, fundamental properties, and preparations are discussed. It turned out that symmetric four- and six-membered cyclic silyl selenides possess well-balanced reactivity/stability, facile and cost-effective synthesis starting from inexpensive and readily available chlorosilanes, improved resistance toward air and moisture, easy handling, sufficient volatility, thermal resistance, and complete gas-to-solid phase exchange reaction with MoCl, affording MoSe nanostructures. These properties make them the most promising Se precursor developed for atomic layer deposition so far.
PubMed: 33748567
DOI: 10.1021/acsomega.1c00223 -
ACS Omega Sep 2018In mass spectrometry (MS)-based proteomics, protein and peptide sequences are determined by the isolation and subsequent fragmentation of precursor ions. When an...
In mass spectrometry (MS)-based proteomics, protein and peptide sequences are determined by the isolation and subsequent fragmentation of precursor ions. When an isolation window captures only part of a precursor's isotopic distribution, the isotope distributions of the fragments depend on the subset of isolated precursor isotopes. Approximation of the expected isotope distributions of these fragments prior to sequence determination enables MS2 deisotoping, monoisotopic mass calculation, charge assignment of fragment peaks, and deconvolution of chimeric spectra. However, currently such methods do not exist, and precursor isotope distributions are often used as a proxy. Here, we present methods that approximate the isotope distribution of a biomolecule's fragment given its monoisotopic mass, the monoisotopic mass of its precursor, the set of isolated precursor isotopes, and optionally sulfur atom content. Our methods use either the Averagine model or splines, the latter of which have similar accuracy to the Averagine approach, but are 20 times faster to compute. Theoretical and approximated isotope distributions are consistent for fragments of in silico digested peptides. Furthermore, mass spectrometry experiments with the angiotensin I peptide and HeLa cell lysate demonstrate that the fragment methods match isotope peaks in MS2 spectra more accurately than the precursor Averagine approach. The algorithms for the approximation of fragment isotope distributions have been added to the OpenMS software library. By providing the means for analyzing fragment isotopic distributions, these methods will improve MS2 spectra interpretation.
PubMed: 30288463
DOI: 10.1021/acsomega.8b01649 -
Genes & Development Jan 2017The ability to maintain and expand the pool of adipocytes in adults is integral to the regulation of energy balance, tissue/stem cell homeostasis, and disease... (Review)
Review
The ability to maintain and expand the pool of adipocytes in adults is integral to the regulation of energy balance, tissue/stem cell homeostasis, and disease pathogenesis. For decades, our knowledge of adipocyte precursors has relied on cellular models. The identity of native adipocyte precursors has remained unclear. Recent studies have identified distinct adipocyte precursor populations that are physiologically regulated and contribute to the development, maintenance, and expansion of adipocyte pools in mice. With new tools available, the properties of adipocyte precursors can now be defined, and the regulation and function of adipose plasticity in development and physiology can be explored.
Topics: Adipocytes, Brown; Adipocytes, White; Adipogenesis; Animals; Cell Differentiation; Humans; Research
PubMed: 28202540
DOI: 10.1101/gad.293704.116