ATP Values Research Articles

Identification of Fitness Determinants during Energy-Limited Growth Arrest in Pseudomonas aeruginosa.

ABSTRACTMicrobial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen. Using transposon-insertion sequencing (Tn-seq), we identified fitness determinants in these two energy-limited states. Multiple genes encoding general functions like transcriptional regulation and energy generation were required for fitness during carbon or oxygen limitation, yet many specific genes, and thus specific activities, differed in their relevance between these states. For instance, the global regulator RpoS was required during both types of energy limitation, while other global regulators such as DksA and LasR were required only during carbon or oxygen limitation, respectively. Similarly, certain ribosomal and tRNA modifications were specifically required during oxygen limitation. We validated fitness defects during energy limitation using independently generated mutants of genes detected in our screen. Mutants in distinct functional categories exhibited different fitness dynamics: regulatory genes generally manifested a phenotype early, whereas genes involved in cell wall metabolism were required later. Together, these results provide a new window into how P. aeruginosa survives growth arrest.

Creatine Monohydrate Enhances Energy Status and Reduces Glycolysis via Inhibition of AMPK Pathway in Pectoralis Major Muscle of Transport-Stressed Broilers.

Creatine monohydrate (CMH) contributes to reduce transport-induced muscle rapid glycolysis and improve meat quality of broilers, but the underlying mechanism is still unknown. Therefore, this study aimed to investigate the molecular mechanisms underlying the ameliorative effects of CMH on muscle glycolysis metabolism of transported broilers during summer. The results showed that 3 h transport during summer elevated chicken live weight loss and plasma corticosterone concentration; decreased muscle concentrations of ATP, creatine, and energy charge value; increased muscle AMP concentration and AMP/ATP ratio; and upregulated muscle mRNA expression of LKB1 and AMPKα2, as well as protein expression of p-LKB1Thr189 and p-AMPKαThr172, which subsequently resulted in rapid glycolysis in the pectoralis major muscle and consequent reduction of meat quality. Dietary addition of CMH at 1200 mg/kg ameliorated transport-induced rapid muscle glycolysis and reduction of meat quality via enhancement of the energy-buffering capacity of intramuscular phosphocreatine/creatine system and inhibition of AMPK pathway.

Fracture resistance of rehabilitated flared root canals with anatomically adjustable fiber post

Aim: This study aimed to evaluate the fracture resistance of the rehabilitated overflared canals with anatomically adjustable everStick post. Patients and methods: Thirty extracted human maxillary central incisors with close similarity were selected. The specimens were coronally horizontally sectioned, endodontically treated and randomly divided into three groups (n = 10). Twenty of specimens were overflared, leaving 5 mm gutta percha seal. Group I: overflared specimens were rehabilitated with everStick post. Group II: overflared specimens were rehabilitated with EasyPost/composite. Group III (control group): specimens had normal unflared canals and were restored with EasyPost/core system. Composite resin was used to complete the core building-up for all groups. Fracture resistance of all specimens was measured using Instron testing machine. Statistical analyses were submitted to one-way analysis of variance and a post-hoc test. The level of significance was adopted atP value less than 0.05. Results: The results showed that the control group recorded the highest fracture resistance values, followed by everStick and EasyPost/composite group and the difference was significant among them (P Conclusion: The use of anatomically adjustable everStick post in rehabilitation of compromised teeth with flared canals seems to be significantly effective, promising in the improvement of fracture resistance, and increase the favorable mode of failure.

Actomyosin interaction at low ATP concentrations.

In vitro motility assay (IVMA) experiments were performed to analyze the movement of actin filaments sliding on a pavement of myosin molecules at different [ATP] and [ADP]. In standard experimental conditions at [ATP]=2mM, about 80% of the actin filaments move in unloaded conditions with a constant velocity. However, a fraction of at least 20% static actin filaments is always present. The accepted explanation is the occurrence of damaged "rigor"-like myosin heads that do not undergo the normal ATP-dependent cycling motion. However, in a series of IVMA experiments performed at different [ATP] we observed that the mobility of actin filaments increased with lowering [ATP]. We investigated the influence of [ATP] on the number of mobile actin filaments. IVMA experiments were performed at controlled nucleotide concentrations and the percentage of mobile filaments accurately determined by specific operator-guided software. The value of ΔG ATP involved was determined. Results showed that the number of mobile actin filaments sliding on type 2B heavy meromyosin isoform (2B HMM) increased at very low [ATP] accompanied by less negative ΔG ATP values. Similar results were obtained by increasing [ADP]. Performing experiments at the same [ATP] with different myosin types, we found a higher number of mobile actin filaments on slow type 1 HMM with respect to type 2B HMM while the highest number of mobile actin filaments was found on single-head myosin (S1 fraction). We also found that [ATP] did not influence the percentage of mobile actin filaments sliding on S1. Our results reveal novel aspects of actomyosin interaction.

Infectious agents after liver transplant: etiology, timeline and patients' cell-mediated immunity responses.

Infections continue to be one of the leading causes of morbidity and mortality in liver transplant recipients. We retrospectively reviewed the symptomatic infectious episodes that occurred during the first year post-transplant to determine time of onset, causative pathogens and cell-mediated immunity response patterns. Ninety-eight of the 202 (48.5%) recipients enrolled developed at least one infectious episode. The total number of infectious episodes was 135: 77 (57.1%) bacterial, 45 (33.3%) viral and 13 (9.6%) fungal. The most frequently isolated bacteria were Escherichia coli (21 isolates) and Klebsiella pneumoniae (19 isolates). Overall, extended-spectrum beta lactamase-producing and methicillin-resistant organisms were responsible for 29 (29/77; 37.7%) infectious episodes. Members of the herpes virus group, in particular cytomegalovirus (34/45 viral infections, 75.5%), were detected. Candida species (9 isolates) followed by Aspergillus species (4 isolates) were isolated. The majority of infections (63%) occurred during the early post-transplant phase (<1month), whereas only 8/135 episodes (5.9%) were detected after the sixth month (late phase). Significantly lower median ImmuKnow® intracellular ATP values in patients who developed bacterial and fungal infections compared to infection-free patients were observed (P<0.0001 and P=0.0016, respectively), whereas patients who developed a viral infection had a median intracellular ATP level not statistically different compared to uninfected patients (P=0.4). Our findings confirm that bacteria are responsible for the majority of symptomatic infections and occur more frequently during the first month post-transplant. The ImmuKnow® measurements can be a useful tool for identifying patients at high risk of developing infection, particularly of fungal and bacterial etiology.

Strategy of mitigating ammonium-rich waste inhibition on anaerobic digestion by using illuminated bio-zeolite fixed-bed process

Intermittent illumination combined with bio-zeolite fixed-bed process was utilized to improve the efficiency of anaerobic digestion with ammonium-rich substrate. The batch experiments were carried out at NH4+-N concentration of 2211mg/L under intermittent illumination and dark (as control) conditions, respectively. The illuminated bioreactor achieved higher methane production (287mL/g-DOC) and ATP value (0.38μmol/L) than that under dark condition. Then the bio-zeolite fixed-bed bioreactor (NH4+-N concentration: 3000mg/L) was used to study the additional efficiency on the illuminated ammonium-rich anaerobic digestion process. The result showed that the illuminated fixed-bed bioreactor presented the greatest methane concentration (70%), methane yield (283mL/g-DOC) and quantity of methanogens comparing with no-bed bioreactor. Furthermore, the illuminated fixed-bed bioreactor achieved better performance during 118-day semi-continuous fermentation. The combination of the intermittent illumination and bio-zeolite fixed-bed strategy contributed to the higher efficiency and stability of the ammonium-rich anaerobic digestion process.

Assessment of terminal cleaning in pediatric isolation rooms: Options for low-resource settings.

Few studies have evaluated terminal cleaning in low-resource settings. Adequacy of pediatric isolation room terminal cleaning was evaluated using quantitative bacterial surface cultures, ATP bioluminescence assays, and fluorescent high-touch surface markers at Tygerberg Children's Hospital in South Africa (August 1, 2014-October 31, 2015). Cleaning adequacy was assessed by comparing pre- and postcleaning measurements. Influence of verbal feedback was determined by comparing cleaners' first and subsequent cleaning episodes. Cleaning methods were compared for cost, time, and feasibility. Adequacy of terminal cleaning was evaluated in 25 isolation rooms after hospitalization for pulmonary tuberculosis (n = 13), respiratory (n = 5) and enteric viruses (n = 5), pertussis (n = 1), and methicillin-resistant Staphylococcus aureus (n = 1). Mean aerobic colony counts and mean ATP relative light units declined between pre- and postcleaning evaluations (39 ± 41 to 15 ± 30 [P < .001] and 72 ± 40 to 23 ± 11 [P < .001]). Fluorescent marker removal was initially poor, but improved significantly at subsequent cleaning episodes (17 out of 78 [22%] to 121 out of 198 [61%]; P < .001); mean aerobic colony counts and ATP values also declined significantly following feedback. Cost, time, and resources required for ATP and surface cultures far exceeded that required for fluorescent markers. Adequacy of isolation room cleaning improved following feedback to cleaning staff. Fluorescent markers are an inexpensive option for cleaning evaluation and training in low-resource settings.

(Invited) Molecular Mechanisms of Signal Transduction in Heme-Containing Oxygen Sensor Proteins

In heme-based gas sensor proteins, heme acts as the sensing site for binding of gaseous molecules, including O2, NO and CO, and indirectly regulates many physiological functions, including the activities of protein kinases, guanylate cyclase, phosphodiesterase, and transcriptional regulatory factors, in response to gas availability. Conceptually, these proteins are always composed of at least two domains: one is a sensor domain (heme-based gas sensing) and the other is a functional domain. However, the structure-function relationship and mechanisms of communication between these domains have not been fully understood. Therefore, we selected a model system, namely a globin-coupled histidine kinase, AfGcHK, in order to study the signal transduction in heme-containing oxygen sensor proteins. The AfGcHK is a part of the two-component signal transduction system from the soil bacterium Anaeromyxobacter sp. Fw109-5. Once the oxygen molecule (as the first signal) binds to the heme iron complex in the sensor domain of AfGcHK, the functional domain is stimulated, leading to autophosphorylation at a conserved His residue in the functional domain. The phosphate group of phosphorylated AfGcHK is then transferred to the cognate response regulator. Several biochemical approaches were utilized in order to study the signal transduction between the sensor and function domains of AfGcHK: (i) enzyme kinetic study, (ii) hydrogen/deuterium exchange experiments associated with mass spectrometry, (iii) cross-linking studies and (iv) small-angle X-ray scattering technique. Overall our results indicated that the coordination and oxidation state of the sensor domain heme iron profoundly affect the enzyme’s catalytic activity of the function domain because they modulate its ATP binding affinity and thus change its k cat/K m ATP value. The possible contact area between sensor and function domains was reveled by hydrogen/deuterium exchange experiments associated with mass spectrometry and cross-linking studies. Small-angle X-ray scattering results offered low-resolution model of the particular domain orientation in solution. All these data together will be discussed in order to illustrate the mechanism of signal transduction in the globin-coupled histidine kinase as a representative of heme-containing oxygen sensor proteins.

Thermodynamics of proton transport coupled ATP synthesis

The thermodynamic H+/ATP ratio of the H+–ATP synthase from chloroplasts was measured in proteoliposomes after energization of the membrane by an acid base transition (Turina et al. 2003 [13], 418–422). The method is discussed, and all published data obtained with this system are combined and analyzed as a single dataset. This meta-analysis led to the following results. 1) At equilibrium, the transmembrane ΔpH is energetically equivalent to the transmembrane electric potential difference. 2) The standard free energy for ATP synthesis (reference reaction) is ΔG°ref=33.8±1.3kJ/mol. 3) The thermodynamic H+/ATP ratio, as obtained from the shift of the ATP synthesis equilibrium induced by changing the transmembrane ΔpH (varying either pHin or pHout) is 4.0±0.1. The structural H+/ATP ratio, calculated from the ratio of proton binding sites on the c-subunit-ring in F0 to the catalytic nucleotide binding sites on the β-subunits in F1, is c/β=14/3=4.7. We infer that the energy of 0.7 protons per ATP that flow through the enzyme, but do not contribute to shifting the ATP/(ADP·Pi) ratio, is used for additional processes within the enzyme, such as activation, and/or energy dissipation, due e.g. to internal uncoupling. The ratio between the thermodynamic and the structural H+/ATP values is 0.85, and we conclude that this value represents the efficiency of the chemiosmotic energy conversion within the chloroplast H+–ATP synthase.

New additive solutions for red cells

Shortly after the introduction of component therapy in the 1960s, the first additives for red cell concentrates (RCC) were introduced. This development resulted in prolongation of RCC shelf life from 21 to 35 or 42 days. Over the years, some new solutions were developed, but still SAGM (Europe) and AS‐1 (United States) are the standard, nearly exclusive in combination with CPD as anticoagulant. Most of these new solutions were minor variations on SAGM or AS‐1, with limited improvement of in vitro quality of erythrocytes. Development of new concepts, resulting in improved quality of RCC, was in first instance focused on achieving longer storage time. However, as a result from the concern about possible negative side effects caused by transfusion of older units, the research on new additive solutions is more focused on having a better quality during the currently accepted maximum storage time of 35–42 days. Around 1990, Meryman developed the concept of the so‐called chloride shift. Through replacement of chloride by impermeable solutes, it is possible to manipulate the intracellular pH of erythrocytes, resulting in high 2,3‐DPG and/or ATP values throughout storage. During the past 15–20 years, several research groups, with the group of Greenwalt and Hess as pioneers, developed new additive solutions based on the Meryman concept. Recently, the first commercial product from these studies was launched, with an improved in vitro quality parameter profile and improved in vivo recovery data. Finally, some recent developments are discussed with respect to alkaline additive solutions and anaerobic storage of erythrocyte concentrates.

In Situ Evaluation of Oxidative Stress in Rat Fatty Liver Induced by a Methionine- and Choline-Deficient Diet.

Nonalcoholic fatty liver disease (NAFLD) is a serious health problem in developed countries. We documented the effects of feeding with a NAFLD-inducing, methionine- and choline-deficient (MCD) diet, for 1–4 weeks on rat liver oxidative stress, with respect to a control diet. Glycogen, neutral lipids, ROS, peroxidated proteins, and SOD2 were investigated using histochemical procedures; ATP, GSH, and TBARS concentrations were investigated by biochemical dosages, and SOD2 expression was investigated by Western Blotting. In the 4-week-diet period, glycogen stores decreased whereas lipid droplets, ROS, and peroxidated proteins expression (especially around lipid droplets of hepatocytes) increased. SOD2 immunostaining decreased in poorly steatotic hepatocytes but increased in the thin cytoplasm of macrosteatotic cells; a trend towards a quantitative decrease of SOD expression in homogenates occurred after 3 weeks. ATP and GSH values were significantly lower for rats fed with the MCD diet with respect to the controls. An increase of TBARS in the last period of the diet is in keeping with the high ROS production and low antioxidant defense; these TBARS may promote protein peroxidation around lipid droplets. Since these proteins play key roles in lipid mobilization, storage, and metabolism, this last information appears significant, as it points towards a previously misconsidered target of NAFLD-associated oxidative stress that might be responsible for lipid dysfunction.

Oligodendrocyte survival, proliferation, and maturation is dependent on 3D hydrogel mechanics

Event Abstract Back to Event Oligodendrocyte survival, proliferation, and maturation is dependent on 3D hydrogel mechanics Lauren N. Russell1 and Kyle Lampe1 1 University of Virginia, Chemical Engineering, United States Introduction: Millions of people suffer from damage or disease to the central nervous system (CNS), such as through a spinal cord injury or multiple sclerosis, resulting in a loss of myelin. In the CNS, oligodendrocytes extend processes which wrap around neuronal axons to generate myelin, an electrically insulating layer conducive to rapid, controlled neuronal signaling. Diminished myelin distorts and slows neuronal communication and causes neuronal degeneration and death. Cell loaded biomaterials are a potential method of repair, but have rarely been investigated for oligodendroglial specification[1]. Here, we investigate how mechanical properties of a polyethylene glycol based hydrogel affect proliferation and differentiation of two oligodendrocyte precursor cell (OPC) lines. Materials and Methods: Hydrogels with controllable storage moduli were formed by photoinitiation of methacrylated polyethylene glycol (PEG) with molecular weights and concentrations ranging from 4600 to 8000 g/mol and 7.5% to 20% (wt/v), respectively. Gelation was accomplished by photoinitiation of LAP at 365 nm and 4 mW/cm2 with OPCs[2],[3] encapsulated at 1x107 cells/ml. Both GFP+ MADM and N20.1 OPC cell lines were studied. ATP and DNA were quantitatively analyzed at discrete time points using high throughput luminescence and fluorescence assays to determine the viability and proliferation. LIVE/DEAD confocal microscopy verified ATP and DNA results. Results and Discussion: PEG molecular weights of 4600, 6000, and 8000 g/mol at 7.5% (wt/v) yielded hydrogels with storage moduli of 1,420 Pa, 795 Pa, and 418 Pa, respectively, similar to different regions of native brain tissue. LIVE/DEAD staining at 1 through 7 days indicated highest viability in the 4600 g/mol condition with high viability for all conditions at 7 days (Figure 1). DNA, cell number, and presence of colonies revealed that proliferation occurred in all conditions with the largest colonies present in less stiff hydrogels. When laminin was incorporated at 25 μg/ml, OPCs spread and extended processes, indicating maturation. Viability and proliferation was also impacted by hydrogel mechanics as the most compliant materials (lowest % wt/v) led to greatest ATP and DNA values with a significant increase over time (Figure 2). Conclusions: The material properties of PEG hydrogels influence oligodendrocyte-like cell proliferation, indicating their potential use in controlled growth of oligodendrocytes for CNS regeneration. In particular, these cell lines favor the more compliant matrices found with either the higher molecular weight conditions (Figure 1) or the lower weight percents of macromer during polymerization (Figure 2). Cellular morphology and process extension is also impacted by these features (Figure 1) and is being investigated toward maturation and oligodendrocyte regeneration. This is the first research to date showing a specific effect of hydrogel modulus on OPC proliferation and maturation. Current research is focused on incorporating topographical cues and degradable subunits into the hydrogel to promote a favorable intracellular redox state. UVA Biotechnology Training Program for fellowship to LNR; Zong and Gaultier labs at UVA for OPC cell lines

ATP bioluminescence values are significantly different depending upon material surface properties of the sampling location in hospitals.

BackgroundOur previous study into assessing hospital cleanliness in Japan by two common methods, ATP bioluminescence and the stamp agar method, revealed considerable variability in the data of both methods (BMC Research Notes, 7: 121, 2014). To investigate the reason(s) for the variability, we reanalyzed the data (n = 752) from the point of view of the material surface properties of sampling sites.MethodsData obtained from surfaces with unknown properties and different purposes such as floor were omitted, and the remaining data (n = 488) were used for this study. The material surface properties on sampling sites were divided into six categories: melamine coated (n = 216), vinyl chloride (n = 16), stainless steel (n = 144), wood (n = 63), and acrylonitrile-butadiene styrene resin coated (n = 48). The data between individual material properties were compared.ResultsThe ATP values of high-touch places were significantly different depending on the type of surface, but no significant difference in stamp values between material properties was seen, indicating that in contrast to stamp values, ATP-accumulation more depends on the physical properties of the material surface such as electronic charges or roughness. To confirm this, we assessed a degree of roughness on vinyl chloride material surface (disutilized floor samples actually used for each of the hospitals) by observation with scanning electron microscope (SEM). As a result, SEM observation similarly revealed considerable roughness on the materials, which may allow microbes to contaminate the materials without noticing it.ConclusionMaterial properties must be considered when evaluating hospital cleanliness with ATP values, and provide a strong warning into evaluating hospital cleanliness.

Black berry juice attenuates neurological disorders and oxidative stress associated with concurrent exposure of aluminum and fluoride in male rats

The objective of this study was to assess the protective effect of black berry juice (BBJ) on the neurological disorders and oxidative stress induced by co-exposure to ALCL3 and NaF in male albino rats. Administration of either AlCl3 (200 mg/kg bw) or NaF (10 mg/kg bw) or both of them caused a significant increase in serum and brain TL, TC, TG as well as serum LDLC and VLDLC levels while serum HDLC level was decreased significantly. Additionally, brain neurotransmitter (DA and 5-HT) levels, AChE, Na-K ATPase activity and ATP values were decreased significantly but NE level was increased in rats administered Al or F alone or in combination. Moreover, a significant increase in brain MDA, NO, H2O2 and free radical enzyme (xanthine oxidase (XO)) and a significant decrease in the level of TAC, SOD and GSH were recorded in AlCl3 or NaF intoxicated rats. In addition, the levels of serum Na, Ca, Cu and zinc (Zn) were significantly diminished, while the level of K was significantly increased. However ALCL3 appears to enhance the neurotoxic hazards caused by NaF. On the other hand, the administration of BBJ (1.6 g/kg bw) showed a marked neuroprotective effect against the biochemical abnormalities that occurred and oxidative stress of the brain induced by co-exposure to AlCl3 and NaF. So, it can be concluded that the consumption of BBJ might be useful for alleviating the neurological disorders and oxidative stress associated with concurrent exposure of ALCL3 and NaF indicating its free radical scavenging and potent antioxidant activity.

Assessment of contamination using an ATP bioluminescence assay on doorknobs in a university-affiliated hospital in Japan.

BackgroundDoorknobs are inevitable points of hand contact. We monitored doorknob contamination in a university hospital using an ATP bioluminescence assay and stamp agar method. We selected grip-, lever-, push-, insert-, and two-pull-type doorknobs in staff lavatories and break rooms, a linen closet, dirty utility rooms, a newborn care unit, clinical lavatories and examination rooms, dressing rooms for radiological tests, and lavatories for health examination, as monitoring points in wards and clinics. Sequential monitoring with an ATP assay (six times) and culture (once) were performed at the same time of day in autumn, winter, and summer. We provided contamination data to appropriate healthcare providers and housekeepers, and queried the staff regarding decontamination of doorknobs.ResultsWhen comparing ATP values on the same type of doorknobs, significant differences in contamination were demonstrated among several clinical rooms and several rooms in wards during all three seasons. No correlation was observed between ATP values on clinical-examination-room doorknobs and outpatient numbers, or between ATP values at any monitoring point and microbial colony-forming units. ATP values on clinical-examination-room doorknobs were reduced after cleaning according to instructions.ConclusionsATP assay is useful for measuring baseline doorknob contamination in clinical rooms. Our findings confirm the need to improve routine decontamination in clinical departments. We need to analyze further the relationship between hospital-acquired infections and doorknob contamination, as assessed by ATP assay in clinics.

Glutamatergic dysfunction linked to energy and membrane lipid metabolism in frontal and anterior cingulate cortices of never treated first-episode schizophrenia patients

BackgroundGlutamatergic dysfunction and altered membrane lipid and energy metabolism have been repeatedly demonstrated in the frontal/prefrontal and anterior cingulate cortex (ACC) in schizophrenia. Though having been already studied in animals, the presumed link between glutamatergic function and structural plasticity has not been investigated directly in the human brain yet. We measured glutamate (Glu), focal energy metabolism, and membrane phospholipid turnover to investigate main pathologies in those key brain regions of schizophrenia. Methods1H- and 31P-Chemical Shift Imaging (CSI) was combined in a single session to assess Glu and markers of energy (PCr, ATP) and membrane lipid (PME, PDE) metabolism in 31 neuroleptic-naïve first acute onset psychosis patients and 31 matched healthy controls. Multivariate analyses of covariance were used to assess disease effects on Glu and to investigate the impact of Glu alterations on phospholipid and energy metabolites. ResultsGlu levels of patients were increased in the frontal and prefrontal cortex bilaterally and in the ACC. Higher Glu was associated with increased left frontal/prefrontal PME and right frontal/prefrontal PDE in patients, which was not observed in healthy controls. In contrast, higher Glu levels were associated with lower PCr or ATP values in the frontal/prefrontal cortex bilaterally and in the right ACC of controls. This was not observed in the right ACC and left frontal/prefrontal cortex of patients. ConclusionFrontal glutamatergic hyperactivity is disconnected from physiologically regulated energy metabolism and is associated with increased membrane breakdown in right and increased membrane restoration in left frontal and prefrontal cortical regions. As indicated by previous findings, this pathology is likely dynamic during the course of first acute illness and possibly associated with negative symptoms and cognitive impairment. Our findings underline the importance of further research on neuroprotective treatment options during the early acute or even better for the ultra-high risk state of psychotic illness.

Comparing ATP values with bacterial contamination in a nursing home

Bacterial surface contamination is an important reservoir for micro-organisms and a potential route for transmission. ATP bioluminescence is a relatively new method to assess environmental contamination, and gives direct results.

Make Reporting of Confidence Intervals de Rigueur

Editors’ Note: In this extended edition of Making Sense of Methods and Measurement, our guest columnist, Greg Gilbert, presents the convincing argument for adopting confidence intervals (CIs) for reporting research results. Traditionally, when researchers report whether outcomes from two interventions were significantly different, they use P values. However, we support the use of CIs to communicate not only whether differences were significant but also what the magnitude of the difference was. If you want to compare whether using simulation first to teach concepts versus using simulation to reinforce concepts is more effective (i.e., produces better learning outcomes), it is helpful to know the magnitude of the effect. A P value can only tell you if there is a significant difference between modalities. A CI allows you to state that if an infinite number of samples were taken, 95% of the time the population mean difference would be between the lower confidence bound and the upper confidence bound. That is a pretty powerful statement. Quantification of the magnitude of the effect lies at the heart of the P valueeCI controversy. For over 30 years, statisticians have been advocating the use of CIs when reporting results; it is time, practitioners heeded this call. This column will discuss a straightforward, simplistic argument for including CIs in your articles. Why notP values?AP value is the probability that random sampling leads to a difference between two statistics, such as samplemeans, that is as extreme ormore extreme than the one observed. Another way of looking atP values is that if another sample of data were taken from the same population, what is the probability of the new test statistic being as extreme or more extreme than the one calculated in the first experiment? P values only provide information regarding statistical

Responses of solid tumor cells in DMEM to reactive oxygen species generated by non-thermal plasma and chemically induced ROS systems.

In this study, we assessed the role of different reactive oxygen species (ROS) generated by soft jet plasma and chemical-induced ROS systems with regard to cell death in T98G, A549, HEK293 and MRC5 cell lines. For a comparison with plasma, we generated superoxide anion (O2−), hydroxyl radical (HO·), and hydrogen peroxide (H2O2) with chemicals inside an in vitro cell culture. Our data revealed that plasma decreased the viability and intracellular ATP values of cells and increased the apoptotic population via a caspase activation mechanism. Plasma altered the mitochondrial membrane potential and eventually up-regulated the mRNA expression levels of BAX, BAK1 and H2AX gene but simultaneously down-regulated the levels of Bcl-2 in solid tumor cells. Moreover, a western blot analysis confirmed that plasma also altered phosphorylated ERK1/2/MAPK protein levels. At the same time, using ROS scavengers with plasma, we observed that scavengers of HO· (mannitol) and H2O2 (catalase and sodium pyruvate) attenuated the activity of plasma on cells to a large extent. In contrast, radicals generated by specific chemical systems enhanced cell death drastically in cancer as well as normal cell lines in a dose-dependent fashion but not specific with regard to the cell type as compared to plasma.

Monitoring Serial CD4+ T-Cell Function After Liver Transplantation Can Be Used to Predict Hepatocellular Carcinoma Recurrence

BackgroundAfter liver transplant (LT), the risk of hepatocellular carcinoma (HCC) recurrence is partially dependent on the degree of immunosuppression. We aimed to determine whether assessing net state of CD4+ T-cell function after LT could determine those at risk for HCC recurrence. MethodsOne hundred thirty-seven patients with cirrhosis who underwent LT for HCC were followed for recurrence of HCC. All patients had serial CD4+ assay performed prospectively. Cox regression analysis was used to assess factors associated with HCC recurrence. Kaplan-Meier plots were used to assess the association between CD4+ ATP values and hazard of HCC recurrence. ResultsThe mean follow-up time was 3.1 ± 1.5 years, during which 14 patients (10%) had HCC recurrence. Patients with combined post-LT CD4+ T-cell function area under curve (AUC) <675 had 6.9 (95% CI 2.0–22.0) times greater hazard of HCC recurrence than those with CD4+ T-cell function AUC ≥675 (P < .001). Less immunosuppression (ATP AUC ≥675) in those beyond Milan conferred a similar risk of recurrence as patients transplanted within Milan (P = .064). ConclusionLower cumulative CD4+ T-cell function post-LT predicted a higher risk of HCC recurrence. These findings may have implications toward management of HCC patients after LT.