Endogenous Agents Research Articles

Apurinic/apyrimidinic endonuclease 1 has major impact in prevention of suicidal covalent DNA-protein crosslink with apurinic/apyrimidinic site in cellular extracts.

DNA-protein crosslinks (DPC) are common DNA lesions induced by various external and endogenous agents. One of the sources of DPC is the apurinic/apyrimidinic site (AP site) and proteins interacting with it. Some proteins possessing AP lyase activity form covalent complexes with AP site-containing DNA without borohydride reduction (suicidal crosslinks). We have shown earlier that tyrosyl-DNA phosphodiesterase 1 (TDP1) but not AP endonuclease 1 (APE1) is able to remove intact OGG1 from protein-DNA adducts, whereas APE1 is able to prevent the formation of DPC by hydrolyzing the AP site. Here we demonstrate that TDP1 can remove intact PARP2 but not XRCC1 from covalent enzyme-DNA adducts with AP-DNA formed in the absence of APE1. We also analyzed an impact of APE1 and TDP1 on the efficiency of DPC formation in APE1-/- or TDP1-/- cell extracts. Our data revealed that APE1 depletion leads to increased levels of PARP1-DNA crosslinks, whereas TDP1 deficiency has little effect on DPC formation.

Methodologies for the detection and sequencing of the epigenetic-like oxidative DNA modification, 8-oxo-7,8-dihydroguanine.

The human genome is constantly threatened by endogenous and environmental DNA damaging agents that can induce a variety of chemically modified DNA lesions including 8-oxo-7,8-dihydroguanine (OG). Increasing evidence has indicated that OG is not only a biomarker for oxidative DNA damage but also a novel epigenetic-like modification involved in regulation of gene expression in mammalian cells. Here we summarize the recent progress in OG research focusing on the following points: (i) the mechanism of OG production in organisms and its biological consequences in cells, (ii) the accurate identification of OG in low-abundance genomes and complex biological backgrounds, (iii) the development of OG sequencing methods. These studies will be helpful for further understanding of the molecular mechanisms of OG-induced mutagenesis and its potential roles in human development and diseases such as cancer.

A-309 Multicenter Performance Evaluation of the ProNephro AKITM Assay and Sample Stability in Pediatric Patients

Abstract Background Acute Kidney Injury (AKI), defined by increased serum creatinine or decreased urine volume, is highly prevalent in critically ill pediatric patients. Those who develop AKI experience worsened outcomes, raising the need for accurate and early biomarkers for AKI. Relying in serum creatinine for AKI diagnosis is unreliable due to its diagnostic inaccuracy and delayed rise in the AKI pathophysiology. Neutrophil Gelatinase-Associated Lipocalin (NGAL) is a novel and widely studied biomarker for early identification of AKI. During pathological progression, NGAL is elevated in blood and urine within two hours of the insult, making it useful for early diagnosis and management of kidney injury in critically ill children. This study aims at evaluating the performance characteristics of a quantitative test for NGAL in urine intended for use in critically ill pediatric patients, and investigating the stability of NGAL in pediatric urine. Methods The ProNephroAKITM is a particle-enhanced turbidimetric immunoassay on the Roche cobas® c501 analyzer to measure NGAL quantitatively in urine in pediatric patients 3 months to 21 years of age. These studies were approved by the respective institutional review boards. The limits of blank (LOB), detection (LOQ) and quantitation (LOQ) were determined following CLSI EP17A2. Linearity was assessed across the measurement range (MR) of 50-3000 ng/mL. The assay repeatability, between-run, between-day and total imprecision were determined in pediatric urine samples (n=9, covering the MR) and controls (n=2) following CLSI EP5-03 guidelines. Likewise, multisite reproducibility was evaluated in pediatric urine (n=7, covering the MR) and controls (n=2) in 3 laboratories and alternating operators. The assay specificity was assessed in the presence of several endogenous and exogeneous substances (e.g. drugs, contrast agents), potential related cross-reactant molecules, and several pH-values. The stability of NGAL in urine was evaluated using freshly collected pediatric urine samples covering the MR from 16 consented patients after storage at ambient (15-30°C), refrigerated (2-8°C), and frozen temperatures (≤-70°C), and following 3 freeze/thaw cycles. Results The ProNephroAKITM is linear across the MR of 50-3000 ng/mL. The LOB, LOD and LOQ were 9, 14 and 18 ng/mL, respectively. The coefficients of variation (CVs) for repeatability, between-run, between-day and total precision were ≤5.0%, ≤3.1%, ≤1.7% and ≤4.9%, respectively in urine and control samples. The reproducibility across 3 independent laboratories was ≤6.6%. The recovery of NGAL was not significantly affected by endogenous substances, contrast agents, pH (3.3-10.3), and common and special pharmaceutical compounds (exception: very high Cefepime concentrations may decrease NGAL), and potential cross-reactants. Freshly collected urine samples spanning concentrations from 71-2,373 ng/mL were stable (±10% recovery) for 2 days at ambient, 4 days refrigerated and 13 months frozen, and after 3 freeze/thaw cycles. Conclusions We report the performance characteristics of the ProNephroAKITM assay, including excellent precision and adequate reproducibility across 3 laboratories, sensitivity, specificity, and urine sample stability. The test was determined to meet the analytical performance required for clinical use in critically ill pediatric patients at risk of developing or having persistent AKI.

Regulation of yeast <i>RAD9</i> gene in energy charge, intracellular ROS, and cell cycle arrest in response to DNA damage

In various environmental conditions, eukaryotic cells are exposed to many kinds of exogenous toxic agents as well as to endogenous agents like reactive oxygen species (ROS) generated from oxidative metabolism that can all result in damage to DNA. To cope with these types of damage, yeast cells have evolved a number of mechanisms and specific response systems regulated by key control genes. One of which is RAD9 gene that regulates DNA damage and repair checkpoints, and cell cycle arrest. Thus, a series of methods, e.g. oxygen consumption monitoring, physicochemical analysis, and flow cytometry, were used in the present study to investigate the role of the RAD9 gene by using the BY4742 (wild type) and specific knock-out yeast strains (∆rad9) and elucidate the function of this gene in cellular defense mechanism and metabolic response to DNA damage triggered by methyl methanesulfonate (MMS) treatment. The results indicated that fully functional DNA damage repair and cell cycle checkpoint (RAD9, wild type) significantly enhanced mitochondrial activity and oxygen consumption, reduced intracellular ROS accumulation. Fully functional mitochondria attenuated ROS accumulation, enabled efficient mitochondrial electron transport chain (mtETC) and ATP synthesis, and stabilized cellular energy status. Also, high mitochondrial activity acted as a protective mechanism against oxidative stress. In contrast, deletion of the RAD9 (∆rad9) resulted in high ROS accumulation and damaged to mitochondrial DNA, leading to strong inhibition of mitochondrial activity and oxygen consumption. Furthermore, low mitochondrial activity in cells lacking RAD9 (∆rad9) led to the development of oxidative stress. Subsequently, high ROS accumulation in ∆rad9 cells caused a block of the mtETC, repression of ATP synthesis, fluctuation of cellular energy status, and induction of cell cycle arrest at S and G2/M phases.

Sigma-1 receptor signaling: A potential therapeutic approach for ischemic stroke.

Strokes constitute over 50% of all neurological diseases, standing as the foremost cause of physical and mental disability. Currently, there are no widely accepted gold standard treatments for ischemic strokes beyond intravenous thrombolysis and mechanical thrombectomy applied during the acute therapeutic window. Therefore, the need for novel treatments targeting crucial signaling mediators involved in ischemic stroke is of utmost importance. The sigma-1 receptor (S1R), a molecular chaperone located at mitochondria-associated endoplasmic reticulum membranes (MAM), has exhibited neuroprotective effects when modulated by synthetic and endogenous agents across various cerebrovascular diseases. In this review, we describe the emerging therapeutic role of S1R agonists and antagonists in regulating blood-brain barrier (BBB) dysfunction, neuroinflammation, and neurocognitive impairment following ischemic stroke.

Sharp-peaked lanthanide nanocrystals for near-infrared photoacoustic multiplexed differential imaging

Photoacoustic tomography offers a powerful tool to visualize biologically relevant molecules and understand processes within living systems at high resolution in deep tissue, facilitated by the conversion of incident photons into low-scattering acoustic waves through non-radiative relaxation. Although current endogenous and exogenous photoacoustic contrast agents effectively enable molecular imaging within deep tissues, their broad absorption spectra in the visible to near-infrared (NIR) range limit photoacoustic multiplexed imaging. Here, we exploit the distinct ultrasharp NIR absorption peaks of lanthanides to engineer a series of NIR photoacoustic nanocrystals. This engineering involves precise host and dopant material composition, yielding nanocrystals with sharply peaked photoacoustic absorption spectra (~3.2 nm width) and a ~10-fold enhancement in NIR optical absorption for efficient deep tissue imaging. By combining photoacoustic tomography with these engineered nanocrystals, we demonstrate photoacoustic multiplexed differential imaging with substantially decreased background signals and enhanced precision and contrast.

Roles of gender in addressing structural inequality: assessment of Borana women’s endogenous institutional agents of gender amelioration in peace, conflict, and post-conflict settings

ABSTRACT The portrayal of women in traditional societies as victims of conflicts and gender inequalities often overlooks their roles as agents of change. This article examined the roles of Borana women in addressing structural inequality during peace, conflict, and post-conflict settings using endogenous institutions. The study utilized an ethnographic research design and a qualitative research approach. Both primary and secondary data were collected for the study. Key informant interviews and focus group discussions were used to collect primary data, while secondary data were obtained from relevant materials through desk review. The primary data were transcribed, translated, and analyzed using thematic analysis. The findings of the study reveal that Borana women play crucial roles in fighting structural inequality through endogenous institutions in preserving peace, protecting the vulnerables, challenging male dominance, maintaining community life and upholding women’s customary laws. The study also revealed the challenges women face in addressing structural inequality. These findings contribute to feminist theories by emphasizing women’s active and diverse roles in combating structural inequality. Consequently, assertive policy options that safeguard women’s customary rights and endogenous peacemaking practices are needed. Furthermore, the study calls for policy interventions and support systems that empower women and enhance their participation in decision-making processes.

Protective effects of lupeol in rats with renal ischemia‑reperfusion injury.

Acute kidney injury (AKI) caused by ischemia and, exogenous or endogenous nephrotoxic agents poses a serious health issue. AKI is seen in 1% of all hospital admissions, 2-5% of hospitalizations and 67% of intensive care unit (ICU) patients. The in-hospital mortality rates for AKI is 40-50, and >50% for ICU patients. Ischemia-reperfusion (I/R) injury in the kidney can activate inflammatory responses and oxidative stress, resulting in AKI. The common endpoint in acute tubular necrosis is a cellular insult secondary to ischemia or direct toxins, which results in effacement of brush border, cell death and decreased function of tubular cells. The aim of the present study was to assess if the reported antioxidant and anti-inflammatory agent lupeol can exert any effects against renal I/R damage. In total, 24 Wistar Albino rats were randomly assigned into four groups of 6, namely Sham, lupeol, ischemia and therapy groups. In the lupeol group, intraperitoneal administration of 100 mg/kg lupeol was given 1 h before laparotomy, whilst only laparotomy was conducted in the sham group. The renal arteries of both kidneys were clamped for 45 min, 1 h after either intraperitoneal saline injection (in the ischemia group) or 100 mg/kg lupeol application (in the therapy group). The blood samples and renal tissues of all rats were collected after 24 h. In blood samples, blood urea nitrogen (BUN) was measured by the urease enzymatic method, and creatinine was measured by the kinetic Jaffe method. Using ELISA method, TNF-α and IL-6 levels were measured in the blood samples, whereas malondialdehyde (MDA), glutathione (GSH), caspase-3 levels were measured in kidney tissues. In addition, kidney histopathological analysis was performed by evaluating the degree of degeneration, tubular dilatation, interstitial lymphocyte infiltration, protein cylinders, necrosis and loss of brush borders. It was determined that renal damage occurred due to higher BUN, creatinine, MDA, TNF-α and caspase-3 values observed in the kidney tissues and blood samples of rats in ischemia group compared with the Sham group. Compared with those in the ischemia group, rats in the therapy group exhibited increased levels of GSH and reduced levels of BUN, TNF-α, MDA. Furthermore, the ischemia group also had reduced histopathological damage scores. Although differences in creatinine, IL-6 and caspase-3 levels were not statistically significant, they were markedly reduced in the treatment group. Taken together, these findings suggest that lupeol can prevent kidney damage as mainly evidenced by the reduced histopathological damage scores, decreased levels of oxidative stress and reduced levels of inflammatory markers. These properties may allow lupeol to be used in the treatment of AKI.

Vincristine attenuates isoprenaline-induced cardiac hypertrophy in male Wistar rats via suppression of ROS/NO/NF-қB signalling pathways

Vincristine (VCR), a vinca alkaloid with anti-tumor and anti-oxidant properties, is acclaimed to possess cardioprotective action. However, the molecular mechanism underlying this protective effect remains unknown. This study investigated the effects of VCR on isoprenaline (ISO), a beta-adrenergic receptor agonist, induced cardiac hypertrophy in male Wistar rats. Animals were pre-treated with ISO (1 mg/kg) intraperitoneally for 14 days before VCR (25 μg/kg) intraperitoneal injection from days 1 to 28. Thereafter, mechanical, and electrical activities of the hearts of the rats were measured using a non-invasive blood pressure monitor and an electrocardiograph, respectively. After which, the heart was homogenized, and supernatants were assayed for contractile proteins: endothelin-1, cardiac troponin-1, angiotensin-II, and creatine kinase-MB, with markers of oxidative/nitrergic stress (SOD, CAT, MDA, GSH, and NO), inflammation (TNF-a and IL-6, NF-kB), and caspase-3 indicative of VCR reduced elevated blood pressure and reversed the abnormal electrocardiogram. ISO-induced increased endothelin-1, cardiac troponin-1, angiotensin-II, and creatine phosphokinase-MB, which were reversed by VCR. ISO also increased TNF-α, IL-6, NF-kB expression with increased caspase-3-mediated apoptosis in the heart. However, VCR reduced ISO-induced inflammation and apoptosis, with improved endogenous antioxidant agents (GSH, SOD, CAT) relative to ISO controls. Moreso, VCR, protected against ISO-induced histoarchitectural degeneration of cardiac myofibre. The result of this study revealed that VCR treatment significantly reverses ISO-induced cardiac hypertrophic phenotypes, via mechanisms connected to improved levels of proteins involved in excitation-contraction, and suppression of oxido-inflammatory and apoptotic pathways.

In situ study of the effect of endogenous and exogenous agents on color stability, hardness, and surface roughness of an elastomer for facial prostheses.

To evaluate in situ the influence of sweat, oil, sunscreen, and disinfectant solution on the color stability, hardness, and roughness of elastomer for facial prostheses. Standardized and intrinsically pigmented specimens remained in contact with human skin from the same person for 30days, considering exposures (n=36 per group), absent of exposition (Control, C); sweat and oiliness contact (SO); sweat and oiliness associated with sunscreen (SOS); 0.12% chlorhexidine digluconate immersion (CD0.12%); and all agents exposed (SOSCD). The main variables were color change (CIELab and National Standard Bureau system, NBS), Shore A hardness, and surface roughness, measured at baseline and 30days. Qualitative analyses were performed by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The data were analyzed by Kruskal-Wallis tests (color) and two-way ANOVA (hardness and roughness) with Sidak post-test (α=0.05). CD0.12% (1.54±0.49) and SOSCD (2.10±1.03) had similar effects and caused the smallest color changes, considered mild and noticeable (NBS), respectively. SOS promoted the greatest color change (6.99±1.43, NBS: large) and hardness (17.97±0.56); SOS promoted intermediate roughness (3.48±1.05) between SOSCD (2.25±0.53), and two similar groups: C (4.46±0.95), and CD0.12% (4.39±1.26). The qualitative analysis showed an irregular, dense, dry, and whitish layer on the surface of the specimens exposed to sunscreen, which was reduced when in contact with 0.12% chlorhexidine digluconate. Endogenous and exogenous factors are capable of altering elastomer properties. The 0.12% chlorhexidine digluconate minimized the changes caused by sweat, oil, and sunscreen.

STAT signaling pathways in immune cells and their associated mechanisms in cancer pathogenesis

Introduction: Signal transducer and activator of transcriptions (STATs) factors as critical proteins in cell signaling regulate diverse biological processes such as differentiation and proliferation of cells. STATs have been shown to play distinct roles in modulating immune responses mediated by innate and adaptive immune cell subsets due to their significant roles in cytokine signaling. Methods: In the current study, we review recent studies on the contribution of individual STAT proteins to cytokine signaling, development, and activity of diverse immune cells that constitute the whole immune system and help its performance against endogenous or exogenous agents with a particular focus on meaningful STAT factor in each of innate and adaptive immune cells’ subsets to clarify their function in favor of the tumor or against it. Results: Dysregulation of signaling pathways in the immune cells is associated with various immune disorders, such as the inability of immune system cells in the effective destruction of cancerous cells. Increase of knowledge about these pathways’ functions is essential to understand how they can be effectively targeted to eliminate tumors. Conclusion: The majority of immune cells use the Jak/STAT signaling pathway, which is one of the most important signaling pathways with a role in induction of proper immune responses. Since each of the STAT factors has a specific role in diverse immune cells’ subsets, appropriate targeting of them can be a promising strategy for patients who suffer from immune system disorders; specifically it can be beneficial as an approach for cancer immunotherapy.

Inability to rescue stalled ribosomes results in overactivation of the integrated stress response

Endogenous and exogenous chemical agents are known to compromise the integrity of RNA and cause ribosome stalling and collisions. Recent studies have shown that collided ribosomes serve as sensors for multiple processes, including ribosome quality control (RQC) and the integrated stress response (ISR). Since RQC and the ISR have distinct downstream consequences, it is of great importance that organisms activate the appropriate process. We previously showed that RQC is robustly activated in response to collisions and suppresses the ISR activation. However, the molecular mechanics behind this apparent competition were not immediately clear. Here we show that Hel2 does not physically compete with factors of the ISR, but instead its ribosomal-protein ubiquitination activity, and downstream resolution of collided ribosomes, is responsible for suppressing the ISR. Introducing a mutation in the RING domain of Hel2 – which inhibits its ubiquitination activity and downstream RQC but imparts higher affinity of the factor for collided ribosomes – resulted in increased activation of the ISR upon MMS-induced alkylation stress. Similarly, mutating Hel2’s lysine targets in uS10, which is responsible for RQC activation, resulted in increased Gcn4 target induction. Remarkably, the entire process of RQC appears to be limited by the action of Hel2, as the overexpression of this one factor dramatically suppressed activation of the ISR. Collectively, our data suggest that cells evolved Hel2 to bind collided ribosomes with a relatively high affinity, but kept its concentration relatively low, ensuring that it gets exhausted under stress conditions that cannot be resolved by quality control processes.

Quantum-Chemistry Study of the Photophysical Properties of 4-Thiouracil and Comparisons with 2-Thiouracil.

DNA in living beings is constantly damaged by exogenous and endogenous agents. However, in some cases, DNA photodamage can have interesting applications, as it happens in photodynamic therapy. In this work, the current knowledge on the photophysics of 4-thiouracil has been extended by further quantum-chemistry studies to improve the agreement between theory and experiments, to better understand the differences with 2-thiouracil, and, last but not least, to verify its usefulness as a photosensitizer for photodynamic therapy. This study has been carried out by determining the most favorable deactivation paths of UV-vis photoexcited 4-thiouracil by means of the photochemical reaction path approach and an efficient combination of the complete-active-space second-order perturbation theory//complete-active-space self-consistent field (CASPT2//CASSCF), (CASPT2//CASPT2), time-dependent density functional theory (TDDFT), and spin-flip TDDFT (SF-TDDFT) methodologies. By comparing the data computed herein for both 4-thiouracil and 2-thiouracil, a rationale is provided on the relatively higher yields of intersystem crossing, triplet lifetime and singlet oxygen production of 4-thiouracil, and the relatively higher yield of phosphorescence of 2-thiouracil.

Human CST complex restricts excessive PrimPol repriming upon UV induced replication stress by suppressing p21.

DNA replication stress, caused by various endogenous and exogenous agents, halt or stall DNA replication progression. Cells have developed diverse mechanisms to tolerate and overcome replication stress, enabling them to continue replication. One effective strategy to overcome stalled replication involves skipping the DNA lesion using a specialized polymerase known as PrimPol, which reinitiates DNA synthesis downstream of the damage. However, the mechanism regulating PrimPol repriming is largely unclear. In this study, we observe that knockdown of STN1 or CTC1, components of the CTC1/STN1/TEN1 complex, leads to enhanced replication progression following UV exposure. We find that such increased replication is dependent on PrimPol, and PrimPol recruitment to stalled forks increases upon CST depletion. Moreover, we find that p21 is upregulated in STN1-depleted cells in a p53-independent manner, and p21 depletion restores normal replication rates caused by STN1 deficiency. We identify that p21 interacts with PrimPol, and STN1 depletion stimulates p21-PrimPol interaction and facilitates PrimPol recruitment to stalled forks. Our findings reveal a previously undescribed interplay between CST, PrimPol and p21 in promoting repriming in response to stalled replication, and shed light on the regulation of PrimPol repriming at stalled forks.

Modulation of gut microbiota with probiotics as a strategy to counteract endogenous and exogenous neurotoxicity.

The existing data demonstrate that probiotic supplementation affords protective effects against neurotoxicity of exogenous (e.g., metals, ethanol, propionic acid, aflatoxin B1, organic pollutants) and endogenous (e.g., LPS, glucose, Aβ, phospho-tau, α-synuclein) agents. Although the protective mechanisms of probiotic treatments differ between various neurotoxic agents, several key mechanisms at both the intestinal and brain levels seem inherent to all of them. Specifically, probiotic-induced improvement in gut microbiota diversity and taxonomic characteristics results in modulation of gut-derived metabolite production with increased secretion of SFCA. Moreover, modulation of gut microbiota results in inhibition of intestinal absorption of neurotoxic agents and their deposition in brain. Probiotics also maintain gut wall integrity and inhibit intestinal inflammation, thus reducing systemic levels of LPS. Centrally, probiotics ameliorate neurotoxin-induced neuroinflammation by decreasing LPS-induced TLR4/MyD88/NF-κB signaling and prevention of microglia activation. Neuroprotective mechanisms of probiotics also include inhibition of apoptosis and oxidative stress, at least partially by up-regulation of SIRT1 signaling. Moreover, probiotics reduce inhibitory effect of neurotoxic agents on BDNF expression, on neurogenesis, and on synaptic function. They can also reverse altered neurotransmitter metabolism and exert an antiamyloidogenic effect. The latter may be due to up-regulation of ADAM10 activity and down-regulation of presenilin 1 expression. Therefore, in view of the multiple mechanisms invoked for the neuroprotective effect of probiotics, as well as their high tolerance and safety, the use of probiotics should be considered as a therapeutic strategy for ameliorating adverse brain effects of various endogenous and exogenous agents.

Strand-specific PCR-competitive replication and adduct bypass assay for assessing how DNA adducts perturb DNA replication in mammalian cells.

Human genomes are susceptible to damage by a variety of endogenous and exogenous agents. If not repaired, the resulting DNA lesions can potentially lead to mutations, genome instability, and cell death. While existing in vitro experiments allow for characterizing replication outcomes from the use of purified translesion synthesis (TLS) DNA polymerases, such studies often lack the sophistication and dynamic nature of cellular contexts. Here, we present a strand-specific PCR-based Competitive Replication and Adduct Bypass (ssPCR-CRAB) assay designed to investigate quantitatively the impact of DNA lesions on replication efficiency and fidelity in mammalian cells. Combined with genetic manipulation, this approach facilitates the revelation of diverse functions of TLS polymerases in replication across DNA lesions.

Searching for sleep in all the right places: My career in sleep research.

My research has always focused on sleep, whether monitoring neural activity (microwires, c-Fos, calcium imaging), triggering it with optogenetics or pharmacologically (anandamide, cholinergic agonists), or measuring levels of endogenous sleep agents such as adenosine. A recurring theme of my research is to use new tools to find the sweet spot in the brain where the signal to sleep begins. My goal is to identify the circuit, determine whether it degrades with age or disease, and repair the circuit when it fails. I am deeply grateful to my mentors for introducing me to the science of sleep, to my students and colleagues for helping me in my quest, and to the NIH and VA Research for supporting the research. Because of the collective efforts of sleep researchers, the public is more aware of the importance of sleep to a healthy lifestyle.

Nurition and Mechanical Ventilation: a Review article

Patients with critical illnesses frequently need mechanical ventilation as part of their care. Patients who are extremely sick frequently need mechanical ventilation in addition to or instead of spontaneous breathing. In certain situations, poor CO2 elimination (ventilation failure) is the primary issue. Malnutrition is one of the issues that can occur in patients on mechanical ventilation. Patients in critical condition typically cannot consume enough food to meet their own metabolic needs. Enteral nutrition, parenteral nutrition, or a mix of the two can be used to provide nutritional intake. Enteral nutrition can help maintain the intestinal wall's functional integrity by protecting intraepithelial cells, increasing blood flow, and encouraging the production of endogenous trophic agents. In the meantime, parenteral nutrition (PN) must be administered if the patient's nutritional needs are not satisfied within three days, as malnutrition typically develops eight to twelve days following surgery and/or ICU admission. Numerous studies comparing the effects of (enteral nutrition) versus PN nutrition on ICU LOS and mechanical ventilation have found no discernible differences between the two. When comparing EN to PN nutrition, there is a noticeable difference in how well EN reduces infectious complications.

Nurition and Mechanical Ventilation: a Review Article

Patients with critical illnesses are frequently need mechanical ventilation as part of their care, in addition to or instead of spontaneous breathing. In certain situation, poor CO2 elimination (ventilation failure) is the primary issue. Malnutrition is one of the issues that can occur in patients on mechanical ventilation. Patients in critical condition are typically incapable of consuming enough food to meet their metabolic needs. Enteral nutrition, parenteral nutrition, or mix of two are able to provide nutritional intake. Enteral nutrition can help maintain the intestinal wall's functional integrity by protecting intraepithelial cells, increasing blood flow, and encouraging the production of endogenous trophic agents. In the meantime, parenteral nutrition (PN) must be administered if the patient's nutritional needs are not satisfied within three days, as malnutrition typically develops eight to twelve days following surgery and/or ICU admission. Numerous studies comparing the effects of (enteral nutrition) versus PN nutrition on ICU LOS and mechanical ventilation have found no discernible differences between the two. When comparing EN to PN nutrition, there is a noticeable difference in how well EN reduces infectious complications.

Chemoproteomic Profiling of 8-Oxoguanosine-Sensitive RNA-Protein Interactions.

Cellular nucleic acids are subject to assault by endogenous and exogenous agents that can perturb the flow of genetic information. Oxidative stress leads to the accumulation of 8-oxoguanine (8OG) in DNA and RNA. 8OG lesions on mRNA negatively impact translation, but their effect on global RNA-protein interactions is largely unknown. Here, we apply an RNA chemical proteomics approach to investigate the effect of 8OG on RNA-protein binding. We find proteins that bind preferentially to 8OG-modified RNA, including IGF2BP1-3 and hnRNPD, and proteins that are repelled by 8OG such as RBM4. We characterize these interactions using biochemical and biophysical assays to quantify the effect of 8OG on binding and show that a single 8OG abolishes the binding of RBM4 to its preferred CGG-containing substrate. Taken together, our work establishes the molecular consequences of 8OG on cellular RNA-protein binding and provides a framework for interrogating the role of RNA oxidation in biological systems.