Effect of alcohol on cellular membranes

Complexity in a Simple Self-Assembling System: Lecithin-Water-Ethanol Mixtures Exhibit a Re-Entrant Phase Transition and a Vesicle-Micelle Transition (VMT) on Heating

We report surprising results for the self-assembly of lecithin (a common phospholipid) in water-ethanol mixtures. Lecithin forms vesicles (∼100 nm diameter) in water. These vesicles are transformed into small micelles (∼5 nm diameter) by a variety of destabilizing agents such as single-tailed surfactants and alcohols. In a surfactant-induced vesicle-micelle transition (VMT), vesicles steadily convert to micelles upon adding the surfactant─thereby, the turbidity of the solution drops monotonically. Instead, when an alcohol like ethanol is added to lecithin vesicles, we find a new, distinctive pattern in phase behavior as the ethanol fraction feth in water is increased. The turbidity first decreases (from feth = 0 to 37%), then rises sharply (feth = 37 to 50%), and then eventually decreases again (feth > 55%). Concomitant with the turbidity rise, the vesicles separate into two phases around feth = 50% before a single phase reappears at higher feth─in other words, there is a "re-entrant" phase transition from 1-phase to 2-phase and back to 1-phase with increasing feth. Vesicles near the phase boundary (∼feth = 45%) also show a VMT upon heating. Similar patterns are seen with other alcohols such as methanol and propanol. We ascribe these complex trends to the dual role played by alcohols: (a) first, alcohols reduce the propensity for flat lipid bilayers to bend and form closed spherical vesicles; and (b) second, alcohols diminish the tendency of lipids to self-assemble in the solvent mixture. At low alcohol fractions, (a) dominates, causing the initially unilamellar vesicles to grow into multilamellar vesicles (MLVs), which eventually phase-separate. Thereafter, (b) dominates, and the vesicles convert into micelles. Support for our hypothesis comes from scattering (SANS) and microscopy (cryo-TEM). Thus, we have uncovered a general paradigm for lipid self-assembly in solvent mixtures, and this may even have physiological relevance.

Design and Fabrication of Sustained Bacterial Release Scaffolds to Support the Microbiome

Fibres in the micro- and nanometre scale are suited to a broad range of applications, including drug delivery and tissue engineering. Electrospinning is the manufacturing method of choice, but it has some limitations. Novel pressure-driven fibre-forming techniques, like pressurised gyration (PG), overcome these limitations; however, the compatibility of PG with biological materials has not yet been evaluated in detail. For the first time, this limitation of PG was investigated by optimising PG for microbial cell processing and incorporating bacterial cultures into fibrous polymeric scaffolds for sustained release. Multiple polymer-solvent systems were trialled, including polyvinylpyrrolidone (PVP)/phosphate-buffered saline (PBS) 25% w/v, polyethylene oxide (PEO)/PBS 20% w/v, and PVP/ethanol 20% w/v. Rheological studies revealed the surface tension of the PVP/PBS, PEO/PBS, and PVP/ethanol polymer-solvent systems to be 73.2, 73.9, and 22.6 mN/m, respectively. Scanning electron microscopy showed the median fibre diameters to be between 9.8 μm and 26.1 μm, with PVP producing larger fibres. Overnight Bacillus subtilis cultures were then incorporated into the chosen polymeric solutions and processed into fibres using PG. The produced cell-loaded fibres were incubated in LB broth to assess the cell viability of the encapsulated cells. Colony counts post-incubation showed the PVP/PBS 25% fibres resulted in 60% bacterial growth, and PEO/PBS 20% fibres led to 47% bacterial growth, whereas PVP/ethanol 20% fibres did not lead to any bacterial growth. Based on the results gathered during this study, it can be concluded that PG offers a promising way of encapsulating cells and other sensitive biological products while having many notable advantages compared to electrospinning. This research demonstrates proof of concept research-based evidence and showcases the potential of pressurised gyration as a key disruptive innovation in probiotic delivery system design and manufacturing.

Optimization of long-term incubation of precision-cut kidney slices

Precision-cut kidney slices (PCKS) provide a powerful model to close the gap between in vivo and in vitro research. Publications by various authors favor different incubation conditions, media and antibiotics, that have not yet been compared in a standardized manner. After preparation, rat-PCKS were incubated in a total of nine combinations of incubation media and antibiotics for 4 days. We found that a combination of DMEM/F-12 and gentamicin showed the highest levels of viability. Utilizing both qualitative and quantitative methods, we observed stable levels of cellular viability for ten days when incubated in the most suitable medium combination of DMEM and gentamicin. Additionally, a Calcein Acetoxymethyl/Ethidium Homodimer-1 based live/dead Staining, analysis of total protein content and lactate dehydrogenase (LDH) were explored to assess both short- and long-term tissue viability. PCKS showed a significant decrease in total protein content, leveling off at around 60% over the duration of 10 days. To be able to evaluate viability irrespective of decreases in total protein detected, we chose to utilize the alamarBlue Cell Viability Assay. Quantifying both intra- and extracellular activity of LDH, while using different concentrations of ethanol as a positive control, we explored enzyme content as a parameter for cell membrane damage and cytotoxicity in PCKS. Overall, we showed that PCKS are suitable for both short- and long-term observation by optimizing incubation parameters, with numerous possibilities for other assays and methods in future studies.

Direct effects of alcohol on gut-epithelial barrier: Unraveling the disruption of physical and chemical barrier of the gut-epithelial barrier that compromises the host-microbiota interface upon alcohol exposure

The development of alcohol-associated diseases is multifactorial, mechanism of which involves metabolic alteration, dysregulated immune response, and a perturbed intestinal host-environment interface. Emerging evidence has pinpointed the critical role of the intestinal host-microbiota interaction in alcohol-induced injuries, suggesting its contribution to disease initiation and development. To maintain homeostasis in the gut, the intestinal mucosa serves as the first-line defense against exogenous factors in the gastrointestinal tract, including dietary contents and the commensal microbiota. The gut-epithelial barrier comprises a physical barrier lined with a single layer of intestinal epithelial cells and a chemical barrier with mucus trapping host regulatory factors and gut commensal bacteria. In this article, we review recent studies pertaining to the disrupted gut-epithelial barrier upon alcohol exposure and examine how alcohol and its metabolism can affect the regulatory ability of intestinal epithelium.

Ethanol-induced changes to the gut microbiome compromise the intestinal homeostasis: a review

The intestine is the largest organ in terms of surface area in the human body. It is responsible not only for absorbing nutrients but also for protection against the external world. The gut microbiota is essential in maintaining a properly functioning intestinal barrier, primarily through producing its metabolites: short-chain fatty acids, bile acids, and tryptophan derivatives. Ethanol overconsumption poses a significant threat to intestinal health. Not only does it damage the intestinal epithelium, but, maybe foremostly, it changes the gut microbiome. Those ethanol-driven changes shift its metabolome, depriving the host of the protective effect the physiological gut microbiota has. This literature review discusses the impact of ethanol consumption on the gut, the gut microbiota, and its metabolome, providing a comprehensive overview of the mechanisms through which ethanol disrupts intestinal homeostasis and discussing potential avenues for new therapeutic intervention.

Standardization Approaches for Extracellular Vesicle Loading with Oligonucleotides and Biologics

Extracellular vesicles (EVs) are widely recognized for their potential as drug delivery systems. EVs are membranous nanoparticles shed from cells. Among their natural features are their ability to shield cargo molecules against degradation and enable their functional internalization into target cells. Especially biological or bio-inspired large molecules (LMs), like nucleic acids, proteins, peptides, and others, may profit from encapsulation in EVs for drug delivery purposes. In the last years, a variety of loading protocols are explored for different LMs. The lack of standardization in the EV drug delivery field has impeded their comparability so far. Currently, the first reporting frameworks and workflows for EV drug loading are proposed. The aim of this review is to summarize these evolving standardization approaches and set recently developed methods into context. This will allow for enhanced comparability of future work on EV drug loading with LMs.

Neural crest cells and fetal alcohol spectrum disorders: Mechanisms and potential targets for prevention

Fetal alcohol spectrum disorders (FASD) are a group of preventable and nongenetic birth defects caused by prenatal alcohol exposure that can result in a range of cognitive, behavioral, emotional, and functioning deficits, as well as craniofacial dysmorphology and other congenital defects. During embryonic development, neural crest cells (NCCs) play a critical role in giving rise to many cell types in the developing embryos, including those in the peripheral nervous system and craniofacial structures. Ethanol exposure during this critical period can have detrimental effects on NCC induction, migration, differentiation, and survival, leading to a broad range of structural and functional abnormalities observed in individuals with FASD. This review article provides an overview of the current knowledge on the detrimental effects of ethanol on NCC induction, migration, differentiation, and survival. The article also examines the molecular mechanisms involved in ethanol-induced NCC dysfunction, such as oxidative stress, altered gene expression, apoptosis, epigenetic modifications, and other signaling pathways. Furthermore, the review highlights potential therapeutic strategies for preventing or mitigating the detrimental effects of ethanol on NCCs and reducing the risk of FASD. Overall, this article offers a comprehensive overview of the current understanding of the impact of ethanol on NCCs and its role in FASD, shedding light on potential avenues for future research and intervention.

Naltrexone blocks alcohol-induced effects on kappa-opioid receptors in the plasma membrane

Naltrexone (NTX), a homologue of the opiate antidote naloxone, is an orally active long-acting mu-opioid receptor (MOP) antagonist used in the treatment of opiate dependence. NTX is also found to relieve craving for alcohol and is one of the few FDA-approved drugs for alcohol use disorder (AUD). Reports that NTX blocks the actions of endogenous opioids released by alcohol are not convincing, suggesting that NTX interferes with alcohol actions by affecting opioid receptors. MOP and kappa-opioid receptor (KOP) are structurally related but functionally different. MOP is mainly located in interneurons activated by enkephalins while KOP is located in longer projections activated by dynorphins. While the actions of NTX on MOP are well established, the interaction with KOP and addiction is not well understood. We used sensitive fluorescence-based methods to study the influence of alcohol on KOP and the interaction between KOP and NTX. Here we report that alcohol interacts with KOP and its environment in the plasma membrane. These interactions are affected by NTX and are exerted both on KOP directly and on the plasma membrane (lipid) structures ("off-target"). The actions of NTX are stereospecific. Selective KOP antagonists, recently in early clinical trials for major depressive disorder, block the receptor but do not show the full action profile of NTX. The therapeutic effect of NTX treatment in AUD may be due to direct actions on KOP and the receptor environment.

Improved MALDI-TOF MS Identification of Mycobacterium tuberculosis by Use of an Enhanced Cell Disruption Protocol

Mycobacterium tuberculosis is the microorganism that causes tuberculosis, a disease affecting millions of people worldwide. Matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) is a fast, reliable, and cost-effective method for microorganism identification which has been used for the identification of Mycobacterium spp. isolates. However, the mycobacteria cell wall is rich in lipids, which makes it difficult to obtain proteins for MALDI-TOF MS analysis. In this study, two cell preparation protocols were compared: the MycoEx, recommended by MALDI-TOF instrument manufacturer Bruker Daltonics, and the MycoLyser protocol described herein, which used the MagNA Lyser instrument to enhance cell disruption with ethanol. Cell disruption and protein extraction steps with the two protocols were performed using the Mycobacterium tuberculosis H37Rv strain, and the MALDI-TOF MS results were compared. The MycoLyser protocol allowed for improved Biotyper identification of M. tuberculosis since the log(score) values obtained with this protocol were mostly ≥ 1.800 and significantly higher than that underwent MycoEx processing. The identification reliability was increased as well, considering the Bruker criteria. In view of these results, it is concluded that the MycoLyser protocol for mycobacterial cell disruption and protein extraction improves the MALDI-TOF MS method's efficacy for M. tuberculosis identification.

Synergy between Genome Mining, Metabolomics, and Bioinformatics Uncovers Antibacterial Chlorinated Carbazole Alkaloids and Their Biosynthetic Gene Cluster from Streptomyces tubbatahanensis sp. nov., a Novel Actinomycete Isolated from Sulu Sea, Philippines

In this study, a novel actinomycete strain, DSD3025T, isolated from the underexplored marine sediments in Tubbataha Reefs Natural Park, Sulu Sea, Philippines, with the proposed name Streptomyces tubbatahanensis sp. nov., was described using polyphasic approaches and characterized using whole-genome sequencing. Its specialized metabolites were profiled using mass spectrometry and nuclear magnetic resonance analyses, followed by antibacterial, anticancer, and toxicity screening. The S. tubbatahanensis DSD3025T genome was comprised of 7.76 Mbp with a 72.3% G+C content. The average nucleotide identity and digital DNA-DNA hybridization values were 96.5% and 64.1%, respectively, compared with its closest related species, thus delineating the novelty of Streptomyces species. The genome encoded 29 putative biosynthetic gene clusters (BGCs), including a BGC region containing tryptophan halogenase and its associated flavin reductase, which were not found in its close Streptomyces relatives. The metabolite profiling unfolded six rare halogenated carbazole alkaloids, with chlocarbazomycin A as the major compound. A biosynthetic pathway for chlocarbazomycin A was proposed using genome mining, metabolomics, and bioinformatics platforms. Chlocarbazomycin A produced by S. tubbatahanensis DSD3025T has antibacterial activities against Staphylococcus aureus ATCC BAA-44 and Streptococcus pyogenes and showed antiproliferative activity against colon (HCT-116) and ovarian (A2780) human cancer cell lines. Chlocarbazomycin A exhibited no toxicity to liver cells but moderate and high toxicity to kidney and cardiac cell lines, respectively. IMPORTANCE Streptomyces tubbatahanensis DSD3025T is a novel actinomycete with antibiotic and anticancer activities from Tubbataha Reefs Natural Park, a United Nations Educational, Scientific and Cultural Organization World Heritage Site in Sulu Sea and considered one of the Philippines' oldest and most-well-protected marine ecosystems. In silico genome mining tools were used to identify putative BGCs that led to the discovery of genes involved in the production of halogenated carbazole alkaloids and new natural products. By integrating bioinformatics-driven genome mining and metabolomics, we unearthed the hidden biosynthetic richness and mined the associated chemical entities from the novel Streptomyces species. The bioprospecting of novel Streptomyces species from marine sediments of underexplored ecological niches serves as an important source of antibiotic and anticancer drug leads with unique chemical scaffolds.

Combined alcohol and cannabinoid exposure leads to synergistic toxicity by affecting cerebellar Purkinje cells

Combined use of cannabis and alcohol results in greater psychoactive toxicity than either substance alone, but the underlying central mechanisms behind this worsened outcome remain unclear. Here we show that the synergistic effect of Δ⁹-tetrahydrocannabinol (THC) and ethanol on motor incoordination in mice is achieved by activating presynaptic type 1 cannabinoid receptors (CB₁R) and potentiating extrasynaptic glycine receptors (GlyR) within cerebellar Purkinje cells (PCs). The combination of ethanol and THC significantly reduces miniature excitatory postsynaptic current frequency in a CB₁R-dependent manner, while increasing the extrasynaptic GlyR-mediated chronic chloride current, both leading to decreased PC activity. Ethanol enhances THC actions by boosting the blood-brain-barrier permeability of THC and enriching THC in the cell membrane. Di-desoxy-THC, a designed compound that specifically disrupts THC-GlyR interaction without affecting the basic functions of CB₁R and GlyR, is able to restore PC function and motor coordination in mice. Our findings provide potential therapeutic strategies for overcoming the synergistic toxicity caused by combining cannabis and alcohol use.

Estrogenic mixtures induce alterations in lipidomic profiles in the gonads of female oysters

This study aimed to reveal possible alterations to lipidomic profiles in Sydney rock oysters, Saccostrea glomerata, exposed to estrogenic mixtures (i.e., estrone, E1; 17β-estradiol, E2; estriol, E3; 17α-ethinylestradiol, EE2; bisphenol A, BPA; 4-t-octylphenol, 4-t-OP; and 4-nonylphenol, 4-NP) at "low" and "high" concentrations, typical of those detected in Australian and global receiving waters. A seven-day acute exposure window exhibited significantly lower abundances of many non-polar metabolites in digestive gland, gills, and gonads. Overall, there was a strong effect of the carrier solvent ethanol (despite a low exposure of 0.0002%), with all solvent containing treatments exhibiting lower abundances of lipidic metabolites, especially in the gill and digestive gland. No significant changes of the lipidome were exhibited in the male gonad by estrogenic exposure. However, in the female gonad, significant reductions of phospholipids and phosphatidylcholine were associated with exposure to high estrogenic mixtures. We hypothesise that the decreases in these phospholipids in the female gonad may be attributable to 1) lower algal consumption and thus lower uptake of lipidic building blocks; 2) a reduction of available substrates for phospholipid and phosphatidylcholine synthesis; and/or 3) induction of reactive oxygen species via estrogen metabolism, which may cause lipid peroxidation and lower abundance of phospholipids.

Deciphering lipid transfer between and within membranes with time-resolved small-angle neutron scattering

This review focuses on time-resolved neutron scattering, particularly time-resolved small angle neutron scattering (TR-SANS), as a powerful in situ noninvasive technique to investigate intra- and intermembrane transport and distribution of lipids and sterols in lipid membranes. In contrast to using molecular analogues with potentially large chemical tags that can significantly alter transport properties, small angle neutron scattering relies on the relative amounts of the two most abundant isotope forms of hydrogen: protium and deuterium to detect complex membrane architectures and transport processes unambiguously. This review discusses advances in our understanding of the mechanisms that sustain lipid asymmetry in membranes-a key feature of the plasma membrane of cells-as well as the transport of lipids between membranes, which is an essential metabolic process.

Ethanol affects fibroblast behavior differentially at low and high doses: A comprehensive, dose-response evaluation

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Ethanol exhibits hormetic response in terms of cellular activity.

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1 % (v/v) ethanol concentration demarcates non-toxic and toxic range.

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Different types of mitochondrial impairment identified at high dose.

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Cellular toxicity is accompanied by an increase in cellular stiffness.

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Dose-dependent cellular stress response to toxicity is observed.

This study aims to develop a comprehensive understanding of effects of low and high doses of ethanol on cellular biochemistry and morphology. Here, fibroblast cells are exposed to ethanol of varied concentrations [0.005−10 % (v/v)] to investigate cellular activity, cytoskeletal organization, cellular stiffness, mitochondrial structure, and real-time behavior. Our results indicate a sharp difference in cellular behavior above and below 1 % ethanol concentration. A two-fold increase in MTT activity at low doses is observed, whereas at high doses it decreases. This increased activity at low doses does not involve cell proliferation changes or mitochondrial impairment, as seen at higher doses. Moreover, the study identifies different types of mitochondrial structure impairment at high doses. Morphologically, cells demonstrate a gradual change in cytoskeletal organization and an increase in cell stiffness with increase in doses. Cells exhibit adaptation to sub-toxic doses of ethanol, wherein recovery from ethanol-induced stress is a dose-dependent phenomenon. Cell survival at low doses and toxicity at higher doses are attributed to mild and strong oxidative stress, respectively. Overall, the study provides a comprehensive understanding of dose-dependent effects of ethanol, manifesting its biphasic or hormetic response, biochemically, at low doses and illustrating its toxicological effects at higher doses.

A Technical System for the Large-Scale Application of Metabolites From Paecilomyces variotii SJ1 in Agriculture

Compared with endophytes, metabolites from endophytes (MEs) have great potential in agriculture. However, a technique for industrializing the production of MEs is still scarce. Moreover, the establishment of effective methods for evaluating the quality of MEs is hampered by the fact that some compounds with beneficial effects on crops have not been clearly identified. Herein, a system was established for the production, quality control and application of MEs by using the extract from Paecilomyces variotii SJ1 (ZNC). First, the extraction conditions of ZNC were optimized through response surface methodology, after which each batch (500 L) met the consumption requirements of crops in 7,467 hectares. Then, chromatographic fingerprinting and enzyme-linked immunosorbent assay were applied to evaluate the similarity and specificity of unknown effective components in ZNC, ensuring a similarity of more than 90% and a quantitative accuracy of greater than 99.9% for the products from different batches. Finally, the bioactivity of industrially produced ZNC was evaluated in the field, and it significantly increased the potato yields by 4.4–10.8%. Overall, we have established a practical technical system for the large-scale application of ZNC in agriculture.

Plasma membrane integrity: implications for health and disease

Plasma membrane integrity is essential for cellular homeostasis. In vivo, cells experience plasma membrane damage from a multitude of stressors in the extra- and intra-cellular environment. To avoid lethal consequences, cells are equipped with repair pathways to restore membrane integrity. Here, we assess plasma membrane damage and repair from a whole-body perspective. We highlight the role of tissue-specific stressors in health and disease and examine membrane repair pathways across diverse cell types. Furthermore, we outline the impact of genetic and environmental factors on plasma membrane integrity and how these contribute to disease pathogenesis in different tissues.

Experimental and Theoretical Approaches to Describing Interactions in Natural Cell Membranes Occurring as a Result of Fatal Alcohol Poisoning

We propose herein a theoretical model describing the effect of fatal ethanol poisoning on the equilibria between cell membranes and the surrounding ions. Using this model, we determined the parameters characterizing the interaction between the electrolyte solution’s ions and the functional groups on the blood cells’ surface. Via the application of mathematical equations, we calculated the total surface concentrations of the acidic and basic groups, c_A and c_B, and their association constants with solution ions, K_AH and K_BOH. Using the determined parameters and mathematical equations’ values, we calculated the theoretical surface charge density values. We verified the proposed model by comparing these values with experimental data, which were selected based on measurements of the electrophoretic mobility of erythrocyte and thrombocyte membranes. Compatibility of the experimental and theoretical surface charge density values was observed in the range of pH 2–8, while deviations were observed at higher pH values.

Extracellular microvesicles promote microglia-mediated pro-inflammatory responses to ethanol

Alcohol use disorder (AUD) pathology features pro-inflammatory gene induction and microglial activation. The underlying cellular processes that promote this activation remain unclear. Previously considered cellular debris, extracellular vesicles (EVs) have emerged as mediators of inflammatory signaling in several disease states. We investigated the role of microvesicles (MVs, 50 nm-100 µm diameter EVs) in pro-inflammatory and microglial functional gene expression using primary organotypic brain slice culture (OBSC). Ethanol caused a unique immune gene signature that featured: temporal induction of pro-inflammatory TNF-α and IL-1β, reduction of homeostatic microglia state gene Tmem119, progressive increases in purinergic receptor P2RY12 and the microglial inhibitory fractalkine receptor CX3CR1, an increase in the microglial presynaptic gene C1q, and a reduction in the phagocytic gene TREM2. MV signaling was implicated in this response as reduction of MV secretion by imipramine blocked pro-inflammatory TNF-α and IL-1β induction by ethanol, and ethanol-conditioned MVs (EtOH-MVs) reproduced the ethanol-associated immune gene signature in naïve OBSC slices. Depletion of microglia prior to ethanol treatment prevented pro-inflammatory activity of EtOH-MVs, as did incubation of EtOH-MVs with the HMGB1 inhibitor glycyrrhizin. Ethanol caused HMGB1 secretion from cultured BV2 microglia in MVs through activation of PI3 kinase. In summary, these studies find MVs modulate pro-inflammatory gene induction and microglial activation changes associated with ethanol. Thus, MVs may represent a novel therapeutic target to reduce neuroinflammation in the setting of alcohol abuse or other diseases that feature a neuroimmune component. [Correction added on 5 April 2021, after first online publication: The copyright line was changed.].

Staphylococcus aureus Extracellular Vesicles: A Story of Toxicity and the Stress of 2020

Staphylococcus aureus generates and releases extracellular vesicles (EVs) that package cytosolic, cell-wall associated, and membrane proteins, as well as glycopolymers and exoproteins, including alpha hemolysin, leukocidins, phenol-soluble modulins, superantigens, and enzymes. S. aureus EVs, but not EVs from pore-forming toxin-deficient strains, were cytolytic for a variety of mammalian cell types, but EV internalization was not essential for cytotoxicity. Because S. aureus is subject to various environmental stresses during its encounters with the host during infection, we assessed how these exposures affected EV production in vitro. Staphylococci grown at 37 °C or 40 °C did not differ in EV production, but cultures incubated at 30 °C yielded more EVs when grown to the same optical density. S. aureus cultivated in the presence of oxidative stress, in iron-limited media, or with subinhibitory concentrations of ethanol, showed greater EV production as determined by protein yield and quantitative immunoblots. In contrast, hyperosmotic stress or subinhibitory concentrations of erythromycin reduced S. aureus EV yield. EVs represent a novel S. aureus secretory system that is affected by a variety of stress responses and allows the delivery of biologically active pore-forming toxins and other virulence determinants to host cells.

Alcohol Ablation of Cardiac Tissues Quantified and Evaluated Using CIELAB Euclidean Distances

Ethanol solubilizes cell membranes, making it useful for various ablation applications. We examined the effect of time and alcohol type on the extent of ablation, quantified as Euclidean distances between color coordinates. We obtained biopsy punch samples (diameter, 6 mm) of left atrial appendage, atrial, ventricular, and septal tissue from porcine hearts and placed them in transwell plates filled with ethanol or methanol for 10, 20, 30, 40, 50, or 60 min. Control samples were taken for each time point. At each time point, samples were collected, cut transversely, and photographed. With use of a custom MATLAB program, all images were analyzed in the CIELAB color space, which is more perceptually uniform than the red-green-blue color space. Euclidean distances were calculated from CIELAB coordinates. The mean and standard error of these distances were analyzed. Two-way analysis of variance was used to test for differences among time points, and 2-tailed t tests, for differences between the alcohol datasets at each time point. Generally, Euclidean distances differed significantly between all time points, except for those immediately adjacent, and methanol produced larger Euclidean distances than ethanol did. Some tissue showed a plateauing effect, potentially indicating transmurality. Mean Euclidean distances effectively indexed alcohol ablation in cardiac tissue. Furthermore, we found that methanol ablated tissue more effectively than ethanol did. With ethanol, the extent of ablation for atrial tissue was largest at 60 min. We conclude that to achieve full transmurality in clinical applications, ethanol must remain in contact with atrial tissue for at least one hour.

Mitochondrial fusion and Bid-mediated mitochondrial apoptosis are perturbed by alcohol with distinct dependence on its metabolism

Environmental stressors like ethanol (EtOH) commonly target mitochondria to influence the cell’s fate. Recent literature supports that chronic EtOH exposure suppresses mitochondrial dynamics, central to quality control, and sensitizes mitochondrial permeability transition pore opening to promote cell death. EtOH-induced tissue injury is primarily attributed to its toxic metabolic products but alcoholism also impairs tissues that poorly metabolize EtOH. We embarked on studies to determine the respective roles of EtOH and its metabolites in mitochondrial fusion and tBid-induced mitochondrial apoptosis. We used HepG2 cells that do not metabolize EtOH and its engineered clone that expresses EtOH-metabolizing Cytochrome P450 E2 and alcohol dehydrogenase (VL-17A cells). We found that fusion impairment by prolonged EtOH exposure was prominent in VL-17A cells, probably owing to reactive oxygen species increase in the mitochondrial matrix. There was no change in fusion protein abundance, mitochondrial membrane potential or Ca²⁺ uptake. By contrast, prolonged EtOH exposure promoted tBid-induced outer mitochondrial membrane permeabilization and cell death only in HepG2 cells, owing to enhanced Bak oligomerization. Thus, mitochondrial fusion inhibition by EtOH is dependent on its metabolites, whereas sensitization to tBid-induced death is mediated by EtOH itself. This difference is of pathophysiological relevance because of the tissue-specific differences in EtOH metabolism.

The effect of sulfur dioxide addition at crush on the fungal and bacterial communities and the sensory attributes of Pinot gris wines

Modern day winemaking often involves the addition of sulfur dioxide (SO₂) at crush to act as both an antioxidant and an antimicrobial agent. While the effects of SO₂ on microbial communities and particularly on spoilage microorganisms has been well-studied, the advent of culture-independent molecular technologies, such as Illumina sequencing, allows the subject to be re-visited in a new context. High-throughput amplicon sequencing allows for a more thorough evaluation of microbial communities, as thousands of microbial sequences per sample can be identified and even rare microorganisms can be studied. This research investigated whether the addition of different levels of SO₂ at crush (0, 20, or 40 mg/L) would affect the composition of fungal and bacterial communities, as well as the sensory attributes of the resulting wines. Samples were taken from uninoculated fermentations of Pinot gris and analyzed via high-throughput amplicon sequencing using the Illumina MiSeq platform. Yeast relative abundance and overall fungal community composition differed among the SO₂ additions. Notably, a Hanseniaspora yeast appeared in all treatments and persisted until the end of alcoholic fermentation, although its relative abundance was significantly higher in the fermentations to which low or no SO₂ had been added. Two key wine sensory attributes (citrus aroma and pome fruit flavor) differed among the SO₂ treatments. This research provides an in-depth look into the fungal and bacterial communities during alcoholic fermentation and gives a better understanding of the microbial community response to SO₂ additions during the crush period.

Modeling the complex etiology of holoprosencephaly in mice

Holoprosencephaly (HPE) is a common developmental defect caused by failure to define the midline of the forebrain and/or midface. HPE is associated with heterozygous mutations in Nodal and Sonic hedgehog (SHH) pathway components, but clinical presentation is highly variable, and many mutation carriers are unaffected. It is therefore thought that such mutations interact with more common modifiers, genetic and/or environmental, to produce severe patterning defects. Modifiers are difficult to identify, as their effects are context-dependent and occur within the complex genetic and environmental landscapes that characterize human populations. This has made a full understanding of HPE etiology challenging. We discuss here the use of mice, a genetically tractable model sensitive to teratogens, as a system to address this challenge. Mice carrying mutations in human HPE genes often display wide variations in phenotypic penetrance and expressivity when placed on different genetic backgrounds, demonstrating the existence of silent HPE modifier genes. Studies with mouse lines carrying SHH pathway mutations on appropriate genetic backgrounds have led to identification of both genetic and environmental modifiers that synergize with the mutations to produce a spectrum of HPE phenotypes. These models favor a scenario in which multiple modifying influences-both genetic and environmental, sensitizing and protective-interact with bona fide HPE mutations to grade phenotypic outcomes. Despite the complex interplay of HPE risk factors, mouse models have helped establish some clear concepts in HPE etiology. A combination of mouse and human cohort studies should improve our understanding of this fascinating and medically important issue.

Ethanol itself is a holoprosencephaly-inducing teratogen

Ethanol is a teratogen, inducing a variety of structural defects in developing humans and animals that are exposed in utero. Mechanisms of ethanol teratogenicity in specific defects are not well understood. Oxidative metabolism of ethanol by alcohol dehydrogenase or cytochrome P450 2E1 has been implicated in some of ethanol's teratogenic effects, either via production of acetaldehyde or competitive inhibition of retinoic acid synthesis. Generalized oxidative stress in response to ethanol may also play a role in its teratogenicity. Among the developmental defects that ethanol has been implicated in is holoprosencephaly, a failure to define the midline of the forebrain and midface that is associated with a deficiency in Sonic hedgehog pathway function. Etiologically, holoprosencephaly is thought to arise from a complex combination of genetic and environmental factors. We have developed a gene-environment interaction model of holoprosencephaly in mice, in which mutation of the Sonic hedgehog coreceptor, Cdon, synergizes with transient in utero exposure to ethanol. This system was used to address whether oxidative metabolism is required for ethanol's teratogenic activity in holoprosencephaly. We report here that t-butyl alcohol, which is neither a substrate nor an inhibitor of alcohol dehydrogenases or Cyp2E1, is a potent inducer of holoprosencephaly in Cdon mutant mice. Additionally, antioxidant treatment did not prevent ethanol- or t-butyl alcohol-induced HPE in these mice. These findings are consistent with the conclusion that ethanol itself, rather than a consequence of its metabolism, is a holoprosencephaly-inducing teratogen.

Ethanol-dependent expression of the NKG2D ligands MICA/B in human cell lines and leukocytes

Alcohol consumption affects the human immune system, causing a variety of disorders. However, the mechanisms of development of these changes are not fully understood. We hypothesized that ethanol may influence the expression of MICA and MICB, stress-induced molecules capable of regulating the activity of cytotoxic lymphocytes through the interaction with receptor NKG2D, which substantially affects the functionality of cellular immunity. We analyzed the effects of ethanol on MICA/B expression in tumor cell lines and human leukocytes. In the cell line models, ethanol caused different changes in the surface expression of MICA/B; in particular, it induced the translocation of intracellular proteins MICA/B to the cell surface and shedding of MICA (in soluble and microparticle-associated forms) from the plasma membrane. The observed results are not linked with cell death in cultures, taking place only under higher doses of ethanol. Ethanol at physiologically relevant concentrations (and higher) stimulated expression of MICA/B genes in different cell types. The effect of ethanol was more pronounced in hepatocyte line HepG2 compared with hematopoietic cell lines K562, Jurkat, and THP-1. Among the tested leukocytes, the most sensitive to ethanol action were T cells activated ex vivo with IL-2, in which the increase of MICA/B mRNA expression was registered with the smallest dose of ethanol (0.125%). In human monocytes, ethanol may lead to elevations in surface MICA/B levels. Presumably, changes in MICA/B expression caused by ethanol can affect the functions of NKG2D-positive cytotoxic lymphocytes, modulating immune reactions at excessive alcohol consumption.

Observation on the ultrastructure morphology of HeLa cells treated with ethanol: Statistical analysis

It is estimated that 5.9% of all human deaths are attributable to alcohol consumption and that the harmful use of ethanol ranks among the top five risk factors for causing disease, disability, and death worldwide. Ethanol is known to disrupt phospholipid packing and promote membrane hemifusion at lipid bilayers. With the exception of mitochondria involved in hormone synthesis, the sterol content of mitochondrial membranes is low. As membranes that are low in cholesterol have increased membrane fluidity and are the most easily disordered by ethanol, we hypothesize that mitochondria are sensitive targets for ethanol damage. HeLa cells were exposed to 50 mM ethanol and the direct effects of ethanol on cellular ultrastructure were examined utilizing transmission electron microscopy. Our ultramicroscopic analysis revealed that cells exposed to ethanol harbor fewer incidence of apoptotic morphology; however, significant alterations to mitochondria and to nuclei occurred. We observed statistical increases in the amount of irregular cells and cells with multiple nuclei, nuclei harboring indentations, and nuclei with multiple nucleolus-like bodies. Indeed, our analysis revealed that mitochondrial damage is the most extensive type of cellular damage. Rupturing of cristae was the most prominent damage followed by mitochondrial swelling. Ethanol exposure also resulted in increased amounts of mitochondrial rupturing, organelles with linked membranes, and mitochondria localizing to indentations of nuclear membranes. We theorize that these alterations could contribute to cellular defects in oxidative phosphorylation and, by extension, the inability to generate regular levels of cellular adenosine triphosphate.

The Effects of Ethanol on the Morphological and Biochemical Properties of Individual Human Red Blood Cells

Here, we report the results of a study on the effects of ethanol exposure on human red blood cells (RBCs) using quantitative phase imaging techniques at the level of individual cells. Three-dimensional refractive index tomograms and dynamic membrane fluctuations of RBCs were measured using common-path diffraction optical tomography, from which morphological (volume, surface area, and sphericity); biochemical (hemoglobin (Hb) concentration and Hb content); and biomechanical (membrane fluctuation) parameters were retrieved at various concentrations of ethanol. RBCs exposed to the ethanol concentration of 0.1 and 0.3% v/v exhibited cell sphericities higher than those of normal cells. However, mean surface area and sphericity of RBCs in a lethal alcoholic condition (0.5% v/v) are not statistically different with those of healthy RBCs. Meanwhile, significant decreases of Hb content and concentration in RBC cytoplasm at the lethal condition were observed. Furthermore, dynamic fluctuation of RBC membranes increased significantly upon ethanol treatments, indicating ethanol-induced membrane fluidization.

Comparison of the Spasmolytic Effects of Jakyak-Gamcho Decoctions Derived via Different Extractants

Aim. To investigate whether differences in the amounts of effective index components in Jakyak-Gamcho decoctions derived via extraction with either water or ethanol were associated with differential spasmolytic effectiveness. Methods. The amounts of effective index components (paeoniflorin, benzoic acid, glycyrrhizin, and isoliquiritin) contained in water-extracted Jakyak-Gamcho decoction and 70% ethanol-extracted Jakyak-Gamcho decoction were compared by high-performance liquid chromatography. Muscle cramp reduction rates were compared between the two decoctions by comparing the degrees of muscle contraction, measured as the tension developed during electrical stimulation, before and 1 and 2 h after injection in rats. Results. The relative amounts of effective index components were, on average, about 43% higher in the 70% ethanol-extracted decoction than in the water-extracted decoction. Two hours after injection, 0.25 g/kg of 70% ethanol-extracted decoction produced a significantly greater spasmolytic effect than 0.25 g/kg of water-extracted Jakyak-Gamcho decoction or distilled water (both p < 0.05). Conclusion. Differences in the amounts of effective index components resulting from the use of different extractants were associated with differences in spasmolytic effectiveness. Hence, it may be worthwhile to investigate alternative extraction methods in terms of extraction efficiency and in vivo effectiveness for various herbal medicines in the future.

Mycofumigation by the volatile organic compound-producing Fungus Muscodor albus induces bacterial cell death through DNA damage

Muscodor albus belongs to a genus of endophytic fungi that inhibit and kill other fungi, bacteria, and insects through production of a complex mixture of volatile organic compounds (VOCs). This process of mycofumigation has found commercial application for control of human and plant pathogens, but the mechanism of the VOC toxicity is unknown. Here, the mode of action of these volatiles was investigated through a series of genetic screens and biochemical assays. A single-gene knockout screen revealed high sensitivity for Escherichia coli lacking enzymes in the pathways of DNA repair, DNA metabolic process, and response to stress when exposed to the VOCs of M. albus. Furthermore, the sensitivity of knockouts involved in the repair of specific DNA alkyl adducts suggests that the VOCs may induce alkylation. Evidence of DNA damage suggests that these adducts lead to breaks during DNA replication or transcription if not properly repaired. Additional cytotoxicity profiling indicated that during VOC exposure, E. coli became filamentous and demonstrated an increase in cellular membrane fluidity. The volatile nature of the toxic compounds produced by M. albus and their broad range of inhibition make this fungus an attractive biological agent. Understanding the antimicrobial effects and the VOC mode of action will inform the utility and safety of potential mycofumigation applications for M. albus.

Alcohol stress, membranes, and chaperones

Ethanol, which affects all body organs, exerts a number of cytotoxic effects, most of them independent of cell type. Ethanol treatment leads to increased membrane fluidity and to changes in membrane protein composition. It can also interact directly with membrane proteins, causing conformational changes and thereby influencing their function. The cytotoxic action may include an increased level of oxidative stress. Heat shock protein molecular chaperones are ubiquitously expressed evolutionarily conserved proteins which serve as critical regulators of cellular homeostasis. Heat shock proteins can be induced by various forms of stresses such as elevated temperature, alcohol treatment, or ischemia, and they are also upregulated in certain pathological conditions. As heat shock and ethanol stress provoke similar responses, it is likely that heat shock protein activation also has a role in the protection of membranes and other cellular components during alcohol stress.

Comparison of the relative propensities of isoamyl nitrite and sodium nitrite to ameliorate acute cyanide poisoning in mice and a novel antidotal effect arising from anesthetics

Isoamyl nitrite has previously been considered acceptable as an inhaled cyanide antidote; therefore, the antidotal utility of this organic nitrite compared with sodium nitrite was investigated. To facilitate a quantitative comparison, doses of both sodium nitrite and isoamyl nitrite were given intraperitoneally in equimolar amounts to sublethally cyanide-challenged mice. Righting recovery from the knockdown state was clearly compromised in the isoamyl nitrite-treated animals, the effect being attributable to the toxicity of the isoamyl alchol produced during hydrolysis of the isoamyl nitrite to release nitrite anion. Subsequently, inhaled aqueous sodium nitrite aerosol was demonstrated to ameliorate sublethal cyanide toxicity, when provided to mice after the toxic dose, by the more rapid recovery of righting ability compared to that of the control animals given only the toxicant. Aerosolized sodium nitrite has thus been shown by these experiments to have promise as a better alternative to organic nitrites for development as an inhaled cyanide antidote. The inhaled sodium nitrite led to the production of NO in the bloodstream as determined by the appearance of EPR signals attributable to nitrosylhemoglobin and methemoglobin. The aerosol delivery was performed in an unmetered inhalation chamber, and in this study, no attempt was made to optimize the procedure. It is argued that administration of an effective inhaled aqueous sodium nitrite dose in humans is possible, though just beyond the capability of current individual metered-dose inhaler designs, such as those used for asthma. Finally, working at slightly greater than LD50 NaCN doses, it was fortuitously discovered that (i) anesthesia leads to significantly prolonged survival compared to that of unanesthetized animals and that (ii) the antidotal activity of nitrite anion was completely abolished under anesthesia. Plausible explanations for these effects in mice and their practical consequences in relation to testing putative cyanide antidotes are discussed.

Erythrocyte glutathione depletion impairs resistance to haemolysis in women consuming alcohol

Alcohol abuse is known to cause an array of ethanol induced abnormalities in men but very few reports are available on the effect of alcohol in women. None of them discuss the effect of ethanol consumption on erythrocyte membrane. In the present study, erythrocytes in women who consume alcohol showed significant decrease in their ability to resist haemolysis with HPLC studies. Erythrocyte membrane indicates decreased phospholipid (p<0.05) levels, which increased the cholesterol/phospholipid ratio significantly (p<0.01) in women who consume alcohol. This can decrease the fluidity of membrane, which appears to be related to the effect of ethanol on erythrocyte membrane. Also the protection against exogenous and endogenous peroxides in the erythrocytes of alcoholic women is considerably affected due to decreased (p<0.05) activity of catalase, glucose-6-phosphate dehydrogenase, protein-SH group and glutathione (GSH). Enhanced free radical generation induced oxidation of oxyHb to metHb in alcoholics. Increased methemoglobin leads to significant reduction in membrane GSH, which may cause protein thiol oxidation. Thus peroxidative damage to membrane lipids and oxidation of membrane protein thiols potentially harmful to membrane fluidity and flexibility is responsible for decreased resistance to haemolysis as demonstrated in women who consume alcohol.

Oxidative damage in rat erythrocyte membranes following ethanol intake: effect of ethyl pyruvate

Alcoholic patients and experimental animals exposed to ethanol display biochemical signs of oxidative damage, suggesting a possible role of free radicals in causing some of the toxic effects of alcohol. The ester derivative, ethyl pyruvate (EP) is stable in solution and should function as an antioxidant and energy precursor. In the present study, the effect of ethanol intake on plasma membrane fluidity, lipid oxidation and antioxidant enzyme activities (GPx, CAT and SOD) were first evaluated. Secondly, the consequences of ethyl pyruvate treatment on the physico-chemical properties of erythrocyte plasma membranes were investigated. The results obtained demonstrate that ethanol induces an increase in lipid peroxidation, a reduction of GPx activity and fluidity in the hydrophilic-hydrophobic region of the bilayer, moreover an increase of fluidity in hydrophobic part of the plasma membrane was measured. When rats were treated with ethyl pyruvate a partially protective effect can be observed for the hydrophilic-hydrophobic region tested by Laurdan, while EP cannot restore the DPH anisotropy values to the control values. In summary, our data indicate that treatment with EP can only partially reduce ethanol plasma membrane perturbation. Since this study shows an ethyl pyruvate dose-dependent effect, it is important to consider the amount of EP required to maintain the right level of membrane fluidity and polarity. These results could be interesting in order to investigate if EP, due to its radical scavenging effect, can prevent oxidative damage induced by ethanol intake and can protect against injure related with ethanol intake.

Alcoholic muscle disease and biomembrane perturbations (review)

Excessive alcohol ingestion is damaging and gives rise to a number of pathologies that influence nutritional status. Most organs of the body are affected such as the liver and gastrointestinal tract. However, skeletal muscle appears to be particularly susceptible, giving rise to the disease entity alcoholic myopathy. Alcoholic myopathy is far more common than overt liver disease such as cirrhosis or gastrointestinal tract pathologies. Alcohol myopathy is characterised by selective atrophy of Type II (anaerobic, white glycolic) muscle fibres: Type I (aerobic, red oxidative) muscle fibres are relatively protected. Affected patients have marked reductions in muscle mass and impaired muscle strength with subjective symptoms of cramps, myalgia and difficulty in gait. This affects 40-60% of chronic alcoholics (in contrast to cirrhosis, which only affects 15-20% of chronic alcohol misuers).Many, if not all, of these features of alcoholic myopathy can be reproduced in experimental animals, which are used to elucidate the pathological mechanisms responsible for the disease. However, membrane changes within these muscles are difficult to discern even under the normal light and electron microscope. Instead attention has focused on biochemical and other functional studies. In this review, we provide evidence from these models to show that alcohol-induced defects in the membrane occur, including the formation of acetaldehyde protein adducts and increases in sarcoplasmic-endoplasmic reticulum Ca(2+)-ATPase (protein and enzyme activity). Concomitant increases in cholesterol hydroperoxides and oxysterol also arise, possibly reflecting free radical-mediated damage to the membrane. Overall, changes within muscle membranes may reflect, contribute to, or initiate the disturbances in muscle function or reductions in muscle mass seen in alcoholic myopathy. Present evidence suggest that the changes in alcoholic muscle disease are not due to dietary deficiencies but rather the direct effect of ethanol or its ensuing metabolites.

Interaction of alcohol and drugs in fatal poisonings

In Finnish data from 1995-2000, 1006 fatal poisonings due to alcohol (ethanol), a single drug or both were statistically analysed in retrospect to evaluate the interaction between alcohol and drugs. In 53% of these cases, low concentrations of some common benzodiazepines were present. The median postmortem blood alcohol concentration (BAC) was 3.3 percent per thousand (w/w) in the 615 alcohol poisonings, but significantly lower, ranging from 1.3 to 1.7 percent per thousand, when promazine, doxepin, amitriptyline or propoxyphene were found together with alcohol. When levomepromazine, temazepam or zopiclone were present, the median BAC was also significantly lower, 2.5-2.7 percent per thousand. Citalopram and diltiazem did not exhibit a significant effect. The median BAC was significantly lower in cases with high concentrations than in those with low concentrations of a drug (excluding citalopram), suggesting a positive concentration-effect relationship. Fatal toxicity indices (FTIs) were calculated by relating the number of deaths caused by a drug to the corresponding sales figures. Promazine had an extremely high FTI, followed by levomepromazine, propoxyphene, doxepin and amitriptyline. The other drugs had relatively low FTIs. The results reflect not only the acute toxicity of a given drug-alcohol combination but also the manners of use and abuse of these drugs.

Substance abuse and withdrawal in the intensive care unit. Contemporary issues

Because 36% of intentional injury victims are drug dependent, the association between drug abuse and violence, especially in urban settings, is high. Withdrawal syndromes in ICU patients confuse their clinical management, may be extremely difficult to diagnose, are often lethal, need to be suspected, and should be prophylaxed against; therefore, all ICU patients should be considered to be at high risk for drug or alcohol dependence, should be tested for evidence of such drugs, and should be interviewed (together with their family members) for the presence of drug dependence traits. Appropriate patients should be referred for formal evaluation and treatment. Withdrawal syndromes must be promptly recognized, differentiated from traumatic or metabolic deterioration, and immediately treated. As patients are unique, so is their drug dependence. Individualized withdrawal therapy, not a "one method fits all" approach, works best. The mainstay of most withdrawal therapy is supportive care and benzodiazepine therapy. Also, considering the high rate of multiple intoxicants present in trauma patients, withdrawal can occur from multiple agents in a single patient, further compounding these difficulties. Withdrawal from unusual substances, such as GHB, or from therapeutic interventions (e.g., prolonged opioid or benzodiazepine administration) also must be considered.

The role of dietary fat in alcohol's prenatal effects

Pregnant rats were fed a control diet or high saturated fat diet (lard) for 6 weeks prior to breeding and continued to consume these diets during pregnancy. Beginning on gestation day 8, rats in each diet group were intubated with 5.5 or 0 g/kg alcohol. Rats in the 0 g/kg group were pair-fed to those in their respective 5.5 g/kg groups. Offspring were weighed at birth. On postnatal days 18 and 20, they were tested for passive avoidance learning and locomotor activity, respectively. Animals prenatally exposed to alcohol weighed less at birth and at weaning time (21 days of age) and required more trials to reach criterion in the passive avoidance test but did not differ in activity. Diet did not affect any of these measures significantly nor were there any significant interactions. We conclude that high saturated fat from lard does not influence alcohol's prenatal effects.

Rat erythrocyte susceptibility to lipid peroxidation after chronic ethanol intake

Erythrocytes, from 2- and 7-month-old rats chronically fed with a liquid diet containing ethanol, were analyzed for their susceptibility to lipid peroxidation estimated as thiobarbituric acid reactive substance (TBARS) products. In spite of a lower alcohol consumption, adult rats were the more affected by the ethanol treatment. Erythrocyte membranes prepared from alcoholic animals were more sensitive to lipid peroxidation than those prepared from control rats. In both age groups lipid analysis revealed similar changes: 1) an increased cholesterol/phospholipid molar ratio mainly derived from a higher content of cholesterol that accounts for the lower membrane fluidity and the higher tolerance to the disordering effect exerted by ethanol in vitro; 2) an increase of phospholipid unsaturated fatty acids, especially C20:4; 3) a modification of the phospholipid pattern, characterized in the ethanol group by an increase of PE and decrease of PE and decrease of PC levels; moreover, significant increases of the anionic phospholipids were detected in the adult group.

Prenatal high saturated fat diet modifies behavioral effects of prenatal alcohol exposure in rats

Pregnant rats were fed a control diet, a high saturated fat diet, or a high polyunsaturated diet lacking in vitamin E and zinc, for 6 weeks prior to breeding and continued to consume these diets during pregnancy. Beginning on gestation day 8, rats in each diet group were intubated with 5.3 or 0 g/kg alcohol. Rats in the 0 and 3 g/k group were pair fed to those in their respective 5 g/kg groups. A fourth group received one of the three diets ad lib, and was not intubated. On postnatal day 20, offspring were tested for locomotor activity and head-dipping behavior. Animals prenatally exposed to alcohol were more active and made more head dips than pair-fed controls, but only if their mothers consumed the control diet. Alcohol had an opposite effect on offspring whose mothers consumed the high saturated fat diet, and had no effect on animals consuming the high polyunsaturated/no vitamin E or zinc diet. These preliminary results suggest that dietary fat may modify the behavioral effects of prenatal alcohol exposure. This effect may be the result of the stabilizing effect of saturated fats on cell membranes which increases their resistance to perturbation by alcohol.

Oxidation of circulating proteins in alcoholics: role of acetaldehyde and xanthine oxidase

BACKGROUND/AIMS

This study aimed to evaluate the protein and lipid redox status in plasma erythrocytes and erythrocyte ghosts of alcoholics and of patients with non-alcoholic liver disease; we also investigated the relation to glutathione levels and the role of acetaldehyde and xanthine oxidase activity in plasma.

METHODS

Carbonyl and sulfhydryl proteins, glutathione and malondialdehyde levels and the activity of the circulating xanthine oxidase were determined in: active and abstinent alcoholics, patients with chronic viral hepatitis and healthy controls.

RESULTS

Active alcoholics showed a decrease of sulfhydryl protein and glutathione concentrations in plasma, erythrocytes and ghosts compared to the other groups. Also, an increase of the carbonyl protein and malondialdehyde levels and of the activity of circulating xanthine oxidase (9.2 +/- 1.8 nmol.min.ml, p < 0.001) were observed. Significant correlations between carbonyl protein and malondialdehyde concentrations in plasma (r = 0.775, p < 0.001), as well as between daily alcohol intake and carbonyl protein content in plasma (r = 0.879, p < 0.001) and erythrocytes (r = 0.605, p < 0.01) were observed. However, carbonyl protein levels did not correlate with the degree of liver injury. Incubation of plasma with acetaldehyde, but not with ethanol, significantly increased the carbonyl protein formation. Administration of N-Ethylmaleimide, a thiol depletor, or glutathione significantly increased or delayed, respectively, the carbonyl protein formation.

CONCLUSIONS

Proteins are oxidatively modified in plasma and erythrocytes of active alcoholics, whereas no such alterations are detectable in patients with non-alcoholic liver disease. Protein oxidation in alcoholics does not seem to result directly from ethanol; circulating xanthine oxidase, delivered from injured cells, may play a contributory role and glutathione appears to be directly involved in the protection of plasma proteins against acetaldehyde toxicity.

Alcohol modulates alveolar macrophage tumor necrosis factor-alpha, superoxide anion, and nitric oxide secretion in the rat

We investigated the effect of alcohol (ethanol) on the ability of the alveolar macrophage to produce tumor necrosis factor-alpha (TNF-alpha), superoxide anion (O2-), and nitric oxide (NO)--three critical components of pulmonary host defense. Male rats were treated with alcohol either acutely (priming dose 175 mg/100 g of body weight, followed by a 7-hr continuous intravenous infusion of 30 mg/100 g of body weight/hr) or chronically (12-14 weeks of feeding ethanol in a liquid diet). Three hours before sacrifice, the rats received an intravenous injection of saline or lipopolysaccharide (LPS; Escherichia coli, 026:B6, 100 micrograms/100 g of body weight). Alveolar macrophages (AMs) were then isolated by bronchoalveolar lavage and assessed for their in vitro capacity to produce TNF-alpha, O2-, and NO spontaneously and in response to different stimuli. Acute alcohol administration suppressed in vitro LPS-stimulated AM TNF-alpha secretion by 52%. AMs from both pair-and alcohol-fed rats secreted TNF-alpha spontaneously in culture. However, the AMs from chronic alcohol-fed group secreted 42-53% less TNF-alpha spontaneously and in response to LPS, interferon-gamma (IFN-gamma) or IFN-gamma + LPS compared with the AMs from pair-fed group. Systemic LPS treatment inhibited in vitro LPS-stimulated AM TNF-alpha secretion (50%) only in the control rats. Acute alcohol administration enhanced significantly in vitro phorbol 12-myristate 13-acetate (PMA)- and opsonized zymosan (OPZ)-induced AM O2- secretion (4-and 1.8-fold, respectively). Systemic LPS treatment primed the AMs from control rats to secrete 83% more O2- in response to PMA but not OPZ; however, in the acute alcohol-treated group, it suppressed both PMA (54%)- and OPZ (66%)-induced AM O2- release (loss of priming effect of LPS). Chronic alcohol feeding suppressed PMA-induced AM O2- secretion (40%) without affecting the OPZ-induced release. Although systemic LPS treatment had no significant effect on PMA or OPZ-induced AM O2- secretion in the pair-fed group, it enhanced the PMA-stimulated AM O2- release (88%) in the alcohol-fed group. AMs recovered from control or acute alcohol-treated rats did not secrete NO spontaneously in vitro. However, AMs from both pair and chronic alcohol-fed rats secreted NO spontaneously with AMs from chronic alcohol-fed group secreting 34% less. Both acute and chronic alcohol treatment inhibited AM NO secretion in response to IFN-gamma, LPS, and IFN-gamma + LPS significantly. Systemic LPS had no effect on AM NO production in response to different in vitro stimuli in any of the treatment groups. These data suggest that (1) both acute and chronic alcohol administration to rats inhibit AM TNF-alpha and NO secretion; (2) acute and chronic alcohol treatment have differential effects on AM O2- secretion; and (3) alcohol-induced alteration in AM TNF-alpha, O2-, and NO secretion may in part explain the increased susceptibility of alcohol-consuming individuals to pulmonary infections.