Effects of hyperoxia and hypoxia on the proliferation of C2C12 myoblasts

Hyperoxic conditions are known to accelerate skeletal muscle regeneration after injuries. In the early phase of regeneration, macrophages invade the injured area and subsequently secrete various growth factors, which regulate myoblast proliferation and differentiation. Although hyperoxic conditions accelerate muscle regeneration, it is unknown whether this effect is indirectly mediated by macrophages. Here, using C2C12 cells, we show that not only hyperoxia but also hypoxia enhance myoblast proliferation directly, without accelerating differentiation into myotubes. Under hyperoxic conditions (95% O2 + 5% CO2), the cell membrane was damaged because of lipid oxidization, and a disrupted cytoskeletal structure, resulting in suppressed cell proliferation. However, a culture medium containing vitamin C (VC), an antioxidant, prevented this lipid oxidization and cytoskeletal disruption, resulting in enhanced proliferation in response to hyperoxia exposure of ≤4 h/day. In contrast, exposure to hypoxic conditions (95% N2 + 5% CO2) for ≤8 h/day enhanced cell proliferation. Hyperoxia did not promote cell differentiation into myotubes, regardless of whether the culture medium contained VC. Similarly, hypoxia did not accelerate cell differentiation. These results suggest that regardless of hyperoxia or hypoxia, changes in oxygen tension can enhance cell proliferation directly, but do not influence differentiation efficiency in C2C12 cells. Moreover, excess oxidative stress abrogated the enhancement of myoblast proliferation induced by hyperoxia. The present research will contribute to basic data for applying the effects of hyperoxia or hypoxia to muscle regeneration therapy.

Transcriptomic response of Campylobacter jejuni following exposure to acidified sodium chlorite

Chemical decontamination during processing is used in many countries to mitigate the Campylobacter load on chicken meat. Chlorine is a commonly used sanitizer in poultry processing to limit foodborne bacterial pathogens but its efficacy is limited by high bacterial loads and organic material. Acidified sodium chlorite (ASC) is a potential alternative for poultry meat sanitization but little is known about its effects on the cellular response of Campylobacter. In this study, the sensitivity of C. jejuni isolates to ASC was established. RNAseq was performed to characterize the transcriptomic response of C. jejuni following exposure to either chlorine or ASC. Following chlorine exposure, C. jejuni induced an adaptive stress response mechanism. In contrast, exposure to ASC induced higher oxidative damage and cellular death by inhibiting all vital metabolic pathways and upregulating the genes involved in DNA damage and repair. The transcriptional changes in C. jejuni in response to ASC exposure suggest its potential as an effective sanitizer for use in the chicken meat industry.

Association of Kidney-Related Safety Events with Incident Chronic Kidney Disease in Veterans

Objective: The impact of Nonsteroidal Anti-Inflammatory Drugs (NSAID) and iodine-based contrast exposures on developing Chronic Kidney Disease (CKD) is controversial. We examined the association of these exposures with the development of CKD in a Veteran population. Methods: A retrospective case-control study of 154,448 veterans from the Veterans Affairs (VA) Corporate Data Warehouse (CDW) database between 2005 and 2014 was conducted to assess the association between incident stage 3 CKD with Acute Kidney Injury (AKI), NSAID use, iodine-based contrast exposures, and comorbid conditions. Stepwise logistic regression was used to determine multivariable adjusted Odds Ratios (OR). Results: The mean age was 59 (SD±13), and the median eGFR was 84 (IQR: 73, 96). AKI was associated with increased odds of CKD (inpatient: OR=3.76, 95% CI: 3.44, 4.11; outpatient: OR=4.73, 95% CI: 4.09, 5.46) and demonstrated escalated odds with >1 episode (inpatient: OR=5.72, 95% CI: 4.71, 6.95; outpatient: OR=8.36, 95% CI: 6.32, 11.06). Months of NSAID prescriptions was associated with CKD, with ORs at >0-6 months, >6-12 months, and >12 months of 1.27 (95% CI: 1.23, 1.32), 1.54 (95% CI: 1.46, 1.63), and 1.69 (95% CI: 1.62, 1.77) respectively. Iodine-based contrast exposure was associated with increased odds of CKD, with ORs for 1-2 Computed Tomography (CT) scans, ≥3CT scans, and left heart catheterization of 1.29 (95% CI: 1.24, 1.35), 1.29 (95% CI: 1.20, 1.28), and 1.38 (95% CI: 1.17, 1.63) respectively. Conclusion: AKI events, NSAID use, and iodine-based contrast exposures are associated with increased odds for developing stage 3 CKD in veterans.

Effect of nonionic and amphoteric surfactants on salivary pellicles reconstituted in vitro

Surfactants are important components of oral care products. Sodium dodecyl sulfate (SDS) is the most common because of its foaming properties, taste and low cost. However, the use of ionic surfactants, especially SDS, is related to several oral mucosa conditions. Thus, there is a high interest in using non-ionic and amphoteric surfactants as they are less irritant. To better understand the performance of these surfactants in oral care products, we investigated their interaction with salivary pellicles i.e., the proteinaceous films that cover surfaces exposed to saliva. Specifically, we focused on pentaethylene glycol monododecyl ether (C12E5) and cocamidopropyl betaine (CAPB) as model nonionic and amphoteric surfactants respectively, and investigated their interaction with reconstituted salivary pellicles with various surface techniques: Quartz Crystal Microbalance with Dissipation, Ellipsometry, Force Spectroscopy and Neutron Reflectometry. Both C12E5 and CAPB were gentler on pellicles than SDS, removing a lower amount. However, their interaction with pellicles differed. Our work indicates that CAPB would mainly interact with the mucin components of pellicles, leading to collapse and dehydration. In contrast, exposure to C12E5 had a minimal effect on the pellicles, mainly resulting in the replacement/solubilisation of some of the components anchoring pellicles to their substrate.

MO345LIFESAVING BIOMARKERS IN CONTRAST-INDUCED ACUTE KIDNEY INJURY IN ADULT CRITICAL ICU PATIENTS

Background : - Intravenous administration of radiocontrast media is referred to as contrast-induced kidney injury (CI-AKI).CI-AKI is described as the third most common cause of new AKI in hospitalized patients. The occurrence of CI-AKI is reported up to 55% in these high-risk patients.: NGAL (Neutrophil gelatinase-associated Lipocalin)and Cystatin C have been found an early and sensitive marker of acute kidney injury (AKI). Aims To evaluate biomarkers in plasma (P) and urine (U) after intravenous contrast in adult ICU patients. Method Total of 36 patients recruited as per inclusion criteria. ICU patients who were >18 years with radiographic contrast for diagnostic or interventional computed tomography (CT scan), were included. After ethical approval, samples of 5 ml blood and 5 ml urine were collected before contrast exposure and at 4 h, 24 h, and 48 h after contrast exposure. NGAL and Cystatin C assay was done by ELISA, and urinary levels were normalized as per urine creatinine (UCr) values for each sample. In the present study, CI-AKI is defined as a rise in SCr of ≥0.3 mg/dl within 48 hrs. Data presented in a mean or median analysis performed. Results In this study, 30 CT scan episodes requiring intravenous contrast in 25 ICU patients were included. Median age was 36 yrs and 13 (43%) were male. On day of inclusion, median SOFA score was 3; 16% In patients having CI-AKI, mean values changes from pre-contrast to at 4 h, 24 h and 48 h after contrast are presented..Kinetics of plasma (P) and urine (U) NGAL and Cystatin C levels (Mean±SD) with p value among patients having CI-AKI P NGAL (ng/ml), Before Contrast(BC)( 708.5±201.76) , 04hrC(851.5±332.05, p=0.07), 24hrC(1093.25±225.03, p=0.02), 48hrC(788±323.4, p=0.21), UNGAL (ng/mg of U Cr)BC(67.63±48.09) , 04hrC(39.69±19.79, p=0.07) , 24hrC(101.97±90, p=0.12) , 48hrC(59.87±56.85, p=0.73) , P Cystatin C (ng/ml) BC(4698.85±574.71), 04hrC(4704.57±1144.87) , p=0.02) , 24hrC(4428.85±1135.73, p=0.03), 48hrC(4288.85±435.8, p=0.17), U Cystatin C (ng/mg of UCr) BC(3 46.06±224.7), 04hrC(219.66±72.18, p=0.91), 24hrC (470.21±536.28, p=0.99), 48hrC(633.61±811.77, p=0.23). Conclusion ROC curve analysis during pre-contrast exposure: NGAL, and Cystatin C), both plasma and urine level AUC was significantly higher in patients who develop CI-AKI and Post-contrast exposure Plasma levels AUC significantly higher than Urine levels.

Memory-specific correlated neuronal activity in higher-order auditory regions of a parrot

Male budgerigars (Melopsittacus undulatus) are open-ended learners that can learn to produce new vocalisations as adults. We investigated neuronal activation in male budgerigars using the expression of the protein products of the immediate early genes zenk and c-fos in response to exposure to conspecific contact calls (CCs: that of the mate or an unfamiliar female) in three subregions (CMM, dNCM and vNCM) of the caudomedial pallium, a higher order auditory region. Significant positive correlations of Zenk expression were found between these subregions after exposure to mate CCs. In contrast, exposure to CCs of unfamiliar females produced no such correlations. These results suggest the presence of a CC-specific association among the subregions involved in auditory memory. The caudomedial pallium of the male budgerigar may have functional subdivisions that cooperate in the neuronal representation of auditory memory.

Role of Sonographic Imaging Findings in Evaluation of Cases Presenting with History of Blunt Abdominal Trauma in UCMS-TH

INTRODUCTION Physical examination is often unreliable. Computed tomography scan is costly, time consuming, requires injection of contrast, exposure to radiation and patient transport thereby limiting its use. With the usage of sonography, it is possible to evaluate and help in the management of patients with blunt abdominal trauma. The proposed study enables sonographic technique in assessing and accurately detecting the presence of free fluid and to pin point the injured organ, thereby helping the clinicians and surgeons in appropriate management MATERIAL AND METHODS Our study was cross sectional conducted on UCMS-TH, Bhairahawa, Nepal. Total 150 cases with history of blunt abdominal trauma were included and scanned by GE LOGIQ6 PRO ultrasound scanner for the duration of one year. RESULTS A total of 150 patients were evaluated 121 were males and 29 were females. Free fluid was detected in total 112 cases (74.66%) out of which with most common injured solid organs were Liver and spleen in total 31 cases (20.7%) each, which were further confirmed on CT scan. CONCLUSION Ultrasonography is easy to perform, quick, cost effective and is highly sensitive in detecting free fluid and solid organ injuries however insignificant in patients with bowel or mesenteric injuries in cases of blunt abdominal trauma and demand CT scan.

Multi-omic approach provides insights into osmoregulation and osmoconformation of the crab Scylla paramamosain

Osmoregulation and osmoconformation are two mechanisms through which aquatic animals adapt to salinity fluctuations. The euryhaline crab Scylla paramamosain, being both an osmoconformer and osmoregulator, is an excellent model organism to investigate salinity adaptation mechanisms in brachyurans. In the present study, we used transcriptomic and proteomic approaches to investigate the response of S. paramamosain to salinity stress. Crabs were transferred from a salinity of 25 ppt to salinities of 5 ppt or 33 ppt for 6 h and 10 days. Data from both approaches revealed that exposure to 5 ppt resulted in upregulation of ion transport and energy metabolism associated genes. Notably, acclimation to low salinity was associated with early changes in gene expression for signal transduction and stress response. In contrast, exposure to 33 ppt resulted in upregulation of genes related to amino acid metabolism, and amino acid transport genes were upregulated only at the early stage of acclimation to this salinity. Our study reveals contrasting mechanisms underlying osmoregulation and osmoconformation within the salinity range of 5–33 ppt in the mud crab, and provides novel candidate genes for osmotic signal transduction, thereby providing insights on understanding the salinity adaptation mechanisms of brachyuran crabs.