Evaluation of a transbronchial cryoprobe for the ablation of pulmonary nodules: an in vitro pilot study.

BACKGROUND: Ablation of malignant pulmonary nodules is a novel therapeutic option for patients who cannot undergo surgery. Current transthoracic approaches cause pneumothorax and/or bleeding in a significant number of cases. OBJECTIVE: Our purpose with this study was to evaluate cryoablation under in vitro conditions with a commercially available cryosurgery system. METHODS: We used ballistic gelatin to model the thermal conduction of lung tissue. The cryoprobe was inserted in the ballistic gelatin with two thermal sensors, they were placed 0.5 cm and 1.0. cm from the probe, respectively, temperature was measured on both sides. We used single-, double- and triple-freeze protocols to see if we could freeze it to -20 °C. RESULTS: We achieved - 18.6 ± 3.26 °C on the closer sensor (sensor 1) and - 3.7 ± 4.61 °C on the sensor further away (sensor 2) after 15 min using the single-freeze protocol. Using the dual-freeze protocol, we achieved - 23.2 ± 2,23 °C on sensor 1 and - 16.5 ± 2.82 °C on sensor 2. With the triple-freeze protocol we obtained - 23.5 ± 2.38 °C on sensor 1 and - 19.05 ± 3.22 °C on sensor 2. CONCLUSION: With dual-freeze, values above - 20 °C were achieved using nearer sensor data, but a plateau phase occurred as with continuous freezing. Using triple freeze, we reached - 20 °C at a distance of 0.5 cm from the probe, but not at 1 cm; therefore, we did not expand the diameter of the predicted necrosis zone.

The Actigraphy-Based Identification of Premorbid Latent Liability of Schizophrenia and Bipolar Disorder.

(1) Background and Goal: Several studies have investigated the association of sleep, diurnal patterns, and circadian rhythms with the presence and with the risk states of mental illnesses such as schizophrenia and bipolar disorder. The goal of our study was to examine actigraphic measures to identify features that can be extracted from them so that a machine learning model can detect premorbid latent liabilities for schizotypy and bipolarity. (2) Methods: Our team developed a small wrist-worn measurement device that collects and identifies actigraphic data based on an accelerometer. The sensors were used by carefully selected healthy participants who were divided into three groups: Control Group (C), Cyclothymia Factor Group (CFG), and Positive Schizotypy Factor Group (PSF). From the data they collected, our team performed data cleaning operations and then used the extracted metrics to generate the feature combinations deemed most effective, along with three machine learning algorithms for categorization. (3) Results: By conducting the training, we were able to identify a set of mildly correlated traits and their order of importance based on the Shapley value that had the greatest impact on the detection of bipolarity and schizotypy according to the logistic regression, Light Gradient Boost, and Random Forest algorithms. (4) Conclusions: These results were successfully compared to the results of other researchers; we had a similar differentiation in features used by others, and successfully developed new ones that might be a good complement for further research. In the future, identifying these traits may help us identify people at risk from mental disorders early in a cost-effective, automated way.

Correction of overexposure in laser speckle contrast imaging.

Laser speckle contrast imaging (LSCI) is a method to visualize and quantify tissue perfusion and blood flow. A common flaw in LSCI variants is their sensitivity to the optical setup parameters and that they operate well only on statistics of undistorted laser speckle patterns. The signal saturation of the sensors makes the contrast calculation misleading; hence the illumination level must be well controlled. We describe the theoretical explanation for the saturation-caused degradation. We introduce a linear extrapolation method to eliminate the overexposure induced error up to an extent of 60-70% saturated pixel count. This, depending on the contrast value and use case, enables to use 3-8 times higher external illumination level with no deterioration of the contrast calculation and thus the measured blood flow index. Our method enables a higher signal-to-noise ratio in darker areas by allowing the use of higher illumination, utilizing a larger portion of the dynamic range of the sensors, and making the illumination level setting less cumbersome.

Primary Founder Mutations in the PRKDC Gene Increase Tumor Mutation Load in Colorectal Cancer.

The clonal composition of a malignant tumor strongly depends on cellular dynamics influenced by the asynchronized loss of DNA repair mechanisms. Here, our aim was to identify founder mutations leading to subsequent boosts in mutation load. The overall mutation burden in 591 colorectal cancer tumors was analyzed, including the mutation status of DNA-repair genes. The number of mutations was first determined across all patients and the proportion of genes having mutation in each percentile was ranked. Early mutations in DNA repair genes preceding a mutational expansion were designated as founder mutations. Survival analysis for gene expression was performed using microarray data with available relapse-free survival. Of the 180 genes involved in DNA repair, the top five founder mutations were in PRKDC (n = 31), ATM (n = 26), POLE (n = 18), SRCAP (n = 18), and BRCA2 (n = 15). PRKDC expression was 6.4-fold higher in tumors compared to normal samples, and higher expression led to longer relapse-free survival in 1211 patients (HR = 0.72, p = 4.4 × 10-3). In an experimental setting, the mutational load resulting from UV radiation combined with inhibition of PRKDC was analyzed. Upon treatments, the mutational load exposed a significant two-fold increase. Our results suggest PRKDC as a new key gene driving tumor heterogeneity.

muTarget: A platform linking gene expression changes and mutation status in solid tumors.

Large oncology repositories have paired genomic and transcriptomic data for all patients. We used these data to perform two independent analyses: to identify gene expression changes related to a gene mutation and to identify mutations altering the expression of a selected gene. All data processing steps were performed in the R statistical environment. RNA-sequencing and mutation data were acquired from The Cancer Genome Atlas (TCGA). The DESeq2 algorithm was applied for RNA-seq normalization, and transcript variants were annotated with AnnotationDbi. MuTect2-identified somatic mutation data were utilized, and the MAFtools Bioconductor program was used to summarize the data. The Mann-Whitney U test was used for differential expression analysis. The established database contains 7876 solid tumors from 18 different tumor types with both somatic mutation and RNA-seq data. The utility of the approach is presented via three analyses in breast cancer: gene expression changes related to TP53 mutations, gene expression changes related to CDH1 mutations and mutations resulting in altered progesterone receptor (PGR) expression. The breast cancer database was split into equally sized training and test sets, and these data sets were analyzed independently. The highly significant overlap of the results (chi-square statistic = 16 719.7 and P < .00001) validates the presented pipeline. Finally, we set up a portal at http://www.mutarget.com enabling the rapid identification of novel mutational targets. By linking somatic mutations and gene expression, it is possible to identify biomarkers and potential therapeutic targets in different types of solid tumors. The registration-free online platform can increase the speed and reduce the development cost of novel personalized therapies.

Ensemble averaging laser speckle contrast imaging: statistical model of improvement as function of static scatterers.

The appearance of the common artifacts of laser speckle contrast imaging (LSCI), namely the granularity in flow rate estimation caused by static scatterers, is a well-known phenomenon. This artifact can be greatly reduced in spatial speckle contrast calculation using interframe decorrelated illumination, forcing true ensemble averaging. We propose a statistical model, which describes the effect of multiple image acquisitions on the contrast map quality when the illumination stable and when the illumination is decorrelated frame by frame. We investigate the improvement as a function of the ratio of dynamic and static scatterers by formulating a statistical distribution based model, using in simulation, flow phantom and in vivo experiments. Our main finding is that the ensemble averaging yields limited improvement in several practical cases due to the highly heterogeneous scatterer structure of living tissues.

The effect of cognitive dysfunction on mid- and long-term mortality after vascular surgery.

BACKGROUND: In recent decades, previous studies have noted the importance of frailty, which is a frequently used term in perioperative risk evaluations. Psychological and socioeconomical domains were investigated as part of frailty syndrome. The aim of this study was to assess the importance of these factors in mortality after vascular surgery. METHODS: In our prospective, observational study (ClinicalTrials.gov Identifier: NCT02224222), we examined 164 patients who underwent elective vascular surgery between 2014 and 2017. At the outpatient anaesthesiology clinic, patients completed a questionnaire about cognitive functions, depression and anxiety, social support and self-reported quality of life were assessed using a comprehensive frailty index, in addition to medical variables. Propensity score matching was performed to analyse the difference between patients and controls in a nationwide population cohort. The primary outcome was 4 year mortality. The Kaplan-Meier method and Cox regression analysis were used for statistical analyses. RESULTS: The patients' mean age was 67.05 years (SD: 9.49 years). Mini-Mental State Examination scores of less than 27 points were recorded for 41 patients. Overall mortality rates were 22.4 and 47.6% in the control and cognitive impairment groups, respectively (p = 0.013). In the univariate Cox regression analysis, cognitive impairment measured using age- and education-adjusted MMSE scores increased the risk of mortality (AHR: 2.842, 95% CI: 1.389-5.815, p = 0.004). CONCLUSION: Even mild cognitive dysfunction measured preoperatively using the MMSE represents a potentially important risk factor for mortality after vascular surgery.

Association between biofilm-production and antibiotic resistance in Escherichia coli isolates: A laboratory-based case study and a literature review.

Bacteria can enhance their survival by attaching to inanimate surfaces or tissues, and presenting as multicellular communities encased in a protective extracellular matrix called biofilm. There has been pronounced interest in assessing the relationship between the antibiotic resistant phenotype and biofilm-production in clinically-relevant pathogens. The aim of the present paper was to provide additional experimental results on the topic, testing the biofilm-forming capacity of Escherichia coli isolates using in vitro methods in the context of their antibiotic resistance in the form of a laboratory case study, in addition to provide a comprehensive review of the subject. In our case study, a total of two hundred and fifty (n = 250) E. coli isolates, originating from either clean-catch urine samples (n = 125) or invasive samples (n = 125) were included. The colony morphology of isolates were recorded after 24h, while antimicrobial susceptibility testing was performed using the Kirby-Bauer disk diffusion method. Biofilm-formation of the isolates was assessed with the crystal violet tube-adherence method. Altogether 57 isolates (22.8%) isolates were multidrug resistant (MDR), 89 isolates (35.6%) produced large colonies (>3 mm), mucoid variant colonies were produced in 131 cases (52.4%), and 108 (43.2%) were positive for biofilm formation. Biofilm-producers were less common among isolates resistant to third-generation cephalosporins and trimethoprim-sulfamethoxazole (P = 0.043 and P = 0.023, respectively). Biofilms facilitate a protective growth strategy in bacteria, ensuring safety against environmental stressors, components of the immune system and noxious chemical agents. Being an integral part of bacterial physiology, biofilm-formation is interdependent with the expression of other virulence factors (especially adhesins) and quorum sensing signal molecules. More research is required to allow for the full understanding of the interplay between the MDR phenotype and biofilm-production, which will facilitate the development of novel therapeutic strategies.

Biomechanical properties of the bone during implant placement.

BACKGROUND: In this research the biomechanical properties of a bone model was examined. Porcine ribs are used as experimental model. The objective of this research was to investigate and compare the biomechanical properties of the bone model before and after implant placement. METHODS: The bone samples were divided in three groups, Group 1 where ALL-ON-FOUR protocol was used during pre-drilling and placing the implants, Group 2 where ALL-ON-FOUR protocol was used during pre-drilling, and implants were not placed, and Group 3 consisting of intact bones served as a control group. Static and dynamic loading was applied for examining the model samples. Kruskal-Wallis statistical test and as a post-hoc test Mann-Whitney U test was performed to analyze experimental results. RESULTS: According to the results of the static loading, there was no significant difference between the implanted and original ribs, however, the toughness values of the bones decreased largely on account of predrilling the bones. The analysis of dynamic fatigue measurements by Kruskal-Wallis test showed significant differences between the intact and predrilled bones. CONCLUSION: The pre-drilled bone was much weaker in both static and dynamic tests than the natural or implanted specimens. According to the results of the dynamic tests and after a certain loading cycle the implanted samples behaved the same way as the control samples, which suggests that implantation have stabilized the skeletal bone structure.

Wnt pathway markers in low-grade and high-grade gliomas.

BACKGROUND AND PURPOSE: Aberrant activation of the Wnt pathway contributes to differentiation and maintenance of cancer stem cells underlying gliomagenesis. The aim of our research was to determine as to what degrees some Wnt markers are expressed in gliomas of different grades, lineages and molecular subtypes. METHODS: Nine grade II, 10 grade III and 72 grade IV surgically removed, formalin-fixed paraffin-embedded glioma specimens were included. Mutation status of IDH1 codon 132 was defined by immunohistochemistry and pyrosequencing in all tumors. Grade II and III astrocytic and oligodendroglial tumors were further tested for the expression of p53 and ATRX by immunohistochemistry, and codeletion of 1p19q by fluorescent in situ hybridization. Expression levels of the non-canonical Wnt5a and Fzd2, and the canonical Wnt3a and beta-catenin Wnt pathway markers were determined by immunohistochemistry, and compared between subgroups stratified according to grade, lineage and the presence or absence of IDH1 R132H/C mutations. RESULTS: In the normal brain - grade II-IV glioma comparisons, a gradual increase was observed for the expressions of Wnt5a, Wnt3a, Fzd2 and beta-catenin. In the astroglial and oligodendroglial lineages of grade II and III gliomas, only the Wnt5a expression was significantly higher in the astroglial subgroup. Stratification according to the IDH1 status resulted in a significant increase of the Wnt3 expression in the wild type grade II-IV gliomas. CONCLUSION: These data extend previous observations and show a correlation of Wnt pathway activity with glioma grade. Further investigations of the Wnt marker expression regulation according to glioma lineage or IDH gene mutational status are in progress by using more exact molecular approaches.

Therapeutic Hypothermia in Critically Ill Patients: A Systematic Review and Meta-Analysis of High Quality Randomized Trials.

OBJECTIVES: To investigate the effect of the application of therapeutic hypothermia (32-35°C) on survival and major clinical endpoints in critically ill patients. DATA SOURCES: We searched online database and clinical trial registries dated up to April 30, 2019, and references of relevant studies. STUDY SELECTION: Low risk of bias randomized trials which compared hypothermia applied for at least 24 hours and conventional therapy in critically ill patients were included. We excluded trials investigating therapeutic hypothermia in indications already supported by international guidelines (adult cardiac arrest and hypoxic-ischemic encephalopathy of newborns) or intraoperative hypothermia. DATA EXTRACTION: Titles and abstracts were reviewed independently by two authors. If the articles seemed eligible, full-text articles were reviewed, and data were abstracted using a structured template. DATA SYNTHESIS: Our search retained 14 low risk of bias randomized trials (2,670 patients) performed in three different settings: traumatic brain injury, serious infections, and stroke. Therapeutic hypothermia was associated with an increase in mortality at longest follow-up available (432/1,375 [31%] vs 330/1,295 [25%]; risk ratio, 1.24; 95% CI, 1.10-1.39; p = 0.0004; I = 0%). Pooled results showed no difference of good neurologic outcome among survivors between the two treatment arms (493/1,142 [43%] vs 486/1,067 [46%]; risk ratio, 1.04; 95% CI, 0.97-1.12; p = 0.27; I = 1%). Arrhythmias were significantly increased among patients undergoing therapeutic hypothermia. We found no difference between groups in pneumonia, serious infections, any infection, hemorrhage, renal failure, deep vein thrombosis, and uncontrollable intracranial hypertension. CONCLUSIONS: High-quality randomized evidence indicates that therapeutic hypothermia is associated with higher mortality and no difference in good neurologic outcome compared with normothermia in critically ill patients. Although there still might be a possibility that therapeutic hypothermia is beneficial in a specific setting, routine application of therapeutic hypothermia would better be avoided outside the settings indicated by international guidelines (adult cardiac arrest and hypoxic-ischemic encephalopathy of newborns).

Effect of Continuous Epinephrine Infusion on Survival in Critically Ill Patients: A Meta-Analysis of Randomized Trials.

OBJECTIVES: Epinephrine is frequently used as an inotropic and vasopressor agent in critically ill patients requiring hemodynamic support. Data from observational trials suggested that epinephrine use is associated with a worse outcome as compared with other adrenergic and nonadrenergic vasoactive drugs. We performed a systematic review and meta-analysis of randomized controlled trials to investigate the effect of epinephrine administration on outcome of critically ill patients. DATA SOURCES: PubMed, EMBASE, and Cochrane central register were searched by two independent investigators up to March 2019. STUDY SELECTION: Inclusion criteria were: administration of epinephrine as IV continuous infusion, patients admitted to an ICU or undergoing major surgery, and randomized controlled trials. Studies on epinephrine administration as bolus (e.g., during cardiopulmonary resuscitation), were excluded. The primary outcome was mortality at the longest follow-up available. DATA EXTRACTION: Two independent investigators examined and extracted data from eligible trials. DATA SYNTHESIS: A total of 5,249 studies were assessed, with a total of 12 studies (1,227 patients) finally included in the meta-analysis. The majority of the trials were performed in the setting of septic shock, and the most frequent comparator was a combination of norepinephrine plus dobutamine. We found no difference in all-cause mortality at the longest follow-up available (197/579 [34.0%] in the epinephrine group vs 219/648 [33.8%] in the control group; risk ratio = 0.95; 95% CI, 0.82-1.10; p = 0.49; I = 0%). No differences in the need for renal replacement therapy, occurrence rate of myocardial ischemia, occurrence rate of arrhythmias, and length of ICU stay were observed. CONCLUSIONS: Current randomized evidence showed that continuous IV administration of epinephrine as inotropic/vasopressor agent is not associated with a worse outcome in critically ill patients.

Perioperative Low Tetraiodothyronine Levels and Adverse Outcomes After Heart Transplantation: A Retrospective, Observational Study.

OBJECTIVES: Thyroid dysfunction has been shown to be associated with increased all-cause mortality and severity of chronic heart failure in critical illness and severe cardiac diseases. The present study was conducted to ascertain the relationship between perioperative free triiodothyronine and free tetraiodothyronine (fT4) levels and postoperative adverse outcomes after heart transplantation (HTX). DESIGN: Retrospective, observational study. SETTING: Single-center study in a quaternary care university clinical center. PARTICIPANTS: The study comprised adult patients who underwent HTX between 2015 and 2019 and had at least 1 perioperative thyroid hormone laboratory test on the day of surgery or in the 24 hours before/after the procedure (free triiodothyronine, fT4, and thyroid-stimulating hormone). INTERVENTIONS: No interventions were applied. MEASUREMENTS AND MAIN RESULTS: The primary outcome was primary graft dysfunction (PGD), defined by the consensus conference of the International Society for Heart and Lung Transplantation. A total of 151 patients were included in the final analyses. Twenty-nine (19.2%) patients had PGD. Fourteen (9.3%) patients had low fT4 levels. An independent association was found between fT4 and PGD (odds ratio 6.49; 95% confidence interval 2.26-18.61; p = 0.001), with adjusted multivariate Cox regression models. CONCLUSION: The perioperative fT4 level could be a prognostic marker of adverse outcomes in HTX. The authors suggest appropriate perioperative monitoring of fT4 levels. Additional research is warranted to examine the optimal timing, dosage, and method of replacement.

The Impact of l-Thyroxine Treatment of Donors and Recipients on Postoperative Outcomes After Heart Transplantation.

OBJECTIVE: The effect of thyroid dysfunction on adverse outcomes has been studied in many different patient populations. The objective of this study was to investigate the effect of thyroid hormone supplementation of donors and recipients on postoperative outcomes after orthotopic heart transplantation. DESIGN: Retrospective. SETTING: Single center, university hospital. PARTICIPANTS: Two-hundred and sixty-six consecutive patients undergoing heart transplantation. INTERVENTIONS: No interventions. MEASUREMENTS AND MAIN RESULTS: Demographic, hemodynamic, and clinical characteristics; donor and recipient United Network for Organ Sharing scores; and information on thyroid hormone support of donors and recipients were recorded. During the median follow-up of 4.59 years (interquartile range 4.26-4.92 y), 70 patients (26.3%) died. After adjustments were made for the United Network for Organ Sharing score, recipients who were treated preoperatively with l-thyroxine had a lower risk for all-cause mortality (adjusted hazard ratio [HR] 0.24, 95% confidence interval [CI] 0.06-0.98; p = 0.047) compared with recipients who were not treated with l-thyroxine. In addition, l-thyroxine treatment of donors was associated with a better recipient survival (HR 0.31, 95% CI 0.11-0.87; p = 0.025). CONCLUSIONS: Pretransplantation thyroid hormone supplementation of donors and recipients was associated with improved long-term survival after heart transplantation.

Versatility of microglial bioenergetic machinery under starving conditions.

Microglia are highly dynamic cells in the brain. Their functional diversity and phenotypic versatility brought microglial energy metabolism into the focus of research. Although it is known that microenvironmental cues shape microglial phenotype, their bioenergetic response to local nutrient availability remains unclear. In the present study effects of energy substrates on the oxidative and glycolytic metabolism of primary - and BV-2 microglial cells were investigated. Cellular oxygen consumption, glycolytic activity, the levels of intracellular ATP/ADP, autophagy, mTOR phosphorylation, apoptosis and cell viability were measured in the absence of nutrients or in the presence of physiological energy substrates: glutamine, glucose, lactate, pyruvate or ketone bodies. All of the oxidative energy metabolites increased the rate of basal and maximal respiration. However, the addition of glucose decreased microglial oxidative metabolism and glycolytic activity was enhanced. Increased ATP/ADP ratio and cell viability, activation of the mTOR and reduction of autophagic activity were observed in glutamine-supplemented media. Moreover, moderate and transient oxidation of ketone bodies was highly enhanced by glutamine, suggesting that anaplerosis of the TCA-cycle could stimulate ketone body oxidation. It is concluded that microglia show high metabolic plasticity and utilize a wide range of substrates. Among them glutamine is the most efficient metabolite. To our knowledge these data provide the first account of microglial direct metabolic response to nutrients under short-term starvation and demonstrate that microglia exhibit versatile metabolic machinery. Our finding that microglia have a distinct bioenergetic profile provides a critical foundation for specifying microglial contributions to brain energy metabolism.

Higher Transaminase Levels in the Postoperative Period After Orthotopic Heart Transplantation Are Associated With Worse Survival.

OBJECTIVE: Preoperative liver function in heart failure patients is associated with extensive functional, structural, and hemodynamic abnormalities. The authors hypothesized that perioperative liver dysfunction is associated with worse 2-year survival after orthotopic heart transplantation. DESIGN: Retrospective study. SETTING: Single-center, university hospital. PARTICIPANTS: The study comprised 209 consecutive patients undergoing heart transplantation. INTERVENTIONS: No interventions. MEASUREMENTS AND MAIN RESULTS: Hepatobiliary markers, hemodynamic parameters, echocardiographic parameters, the need for mechanical cardiac support, demographic parameters, and United Network for Organ Sharing and Model for End-Stage Liver Disease (MELD) scores were investigated. Fifty-five patients (26.3%) died, and the mean survival time was 3.61 years after transplantation. In multivariate Cox regression analysis, in addition to the preoperative modified MELD score, the 4th quartiles of the maximum aspartate transaminase (AST) and alanine transaminase levels on the 4th through 7th postoperative days were independently associated with mortality (odds ratio [OR] 2.46, 95% confidence interval [CI] 1.09-5.55; p = 0.031 and OR 2.41, 95% CI 1.13-5.18; p = 0.024, respectively). By expressing the transaminase values as the multiplier of the sex-specific top normal value, the maximum AST and alanine transaminase levels (OR 1.02, 95% CI 1.01-1.02; p < 0.001 and OR 1.02, 95% CI 1.01-1.03; p = 0.001, respectively) were linked to worse survival. Among the postdischarge parameters, the modified MELD score (OR 1.17, 95% CI 1.09-1.27; p < 0.001) and the AST level were associated with postdischarge mortality (OR 1.002, 95% CI 1.001-1.003; p < 0.001 as a continuous variable; OR 1.07, 95% CI 1.05-1.10; p < 0.001, expressed as the multiplier of the sex-specific normal value, respectively). CONCLUSIONS: The severity of postoperative liver dysfunction negatively influences survival after heart transplantation, and liver function should be closely assessed in these patients.

Isocitrate dehydrogenase mutations in defining the biology of and supporting clinical decision making in glioblastoma.

BACKGROUND AND PURPOSE: Oncogenesis is related to a sequential accumulation of somatic mutations. Comprehensive characterizations of the genomic landscapes have been completed recently for several tumors, glioblastoma being among the first ones. Our own translational research studies have been focused on defining molecular subtypes of glioblastoma in the clinical setting because of an expected prognostic and therapeutic utility of the information. Somatic mutations in genes of the isocitrate dehydrogenase (IDH) enzyme family appear to be among the best-defined biomarkers that also influence tumor behavior and confer clinical utility. METHODS: We have reviewed the literature including our own results to summarize basic science and clinical correlates of IDH mutations. RESULTS: The surveyed data reveal genomic, transcriptomic, epigenomic and biochemical consequences of IDH mutations in the context of glioblastoma biology and phenotype. In addition, a few studies highlight the therapeutic potential of targeting IDH, although thus far all tests have only been conducted in the preclinical setting. CONCLUSION: Somatic mutations in isoforms of IDH genes represent important biomarkers that correlate with biochemical, biological and phenotypic features of glioblastoma, and may also facilitate the development of new therapeutic strategies complementing the currently available approved protocols.

KRAS driven expression signature has prognostic power superior to mutation status in non-small cell lung cancer.

KRAS is the most frequently mutated oncogene in non-small cell lung cancer (NSCLC). However, the prognostic role of KRAS mutation status in NSCLC still remains controversial. We hypothesize that the expression changes of genes affected by KRAS mutation status will have the most prominent effect and could be used as a prognostic signature in lung cancer. We divided NSCLC patients with mutation and RNA-seq data into KRAS mutated and wild type groups. Mann-Whitney test was used to identify genes showing altered expression between these cohorts. Mean expression of the top five genes was designated as a "transcriptomic fingerprint" of the mutation. We evaluated the effect of this signature on clinical outcome in 2,437 NSCLC patients using univariate and multivariate Cox regression analysis. Mutation of KRAS was most common in adenocarcinoma. Mutation status and KRAS expression were not correlated to prognosis. The transcriptomic fingerprint of KRAS include FOXRED2, KRAS, TOP1, PEX3 and ABL2. The KRAS signature had a high prognostic power. Similar results were achieved when using the second and third set of strongest genes. Moreover, all cutoff values delivered significant prognostic power (p < 0.01). The KRAS signature also remained significant (p < 0.01) in a multivariate analysis including age, gender, smoking history and tumor stage. We generated a "surrogate signature" of KRAS mutation status in NSCLC patients by computationally linking genotype and gene expression. We show that secondary effects of a mutation can have a higher prognostic relevance than the primary genetic alteration itself.

Abolition of mitochondrial substrate-level phosphorylation by itaconic acid produced by LPS-induced Irg1 expression in cells of murine macrophage lineage.

Itaconate is a nonamino organic acid exhibiting antimicrobial effects. It has been recently identified in cells of macrophage lineage as a product of an enzyme encoded by immunoresponsive gene 1 (Irg1), acting on the citric acid cycle intermediate cis-aconitate. In mitochondria, itaconate can be converted by succinate-coenzyme A (CoA) ligase to itaconyl-CoA at the expense of ATP (or GTP), and is also a weak competitive inhibitor of complex II. Here, we investigated specific bioenergetic effects of increased itaconate production mediated by LPS-induced stimulation of Irg1 in murine bone marrow-derived macrophages (BMDM) and RAW-264.7 cells. In rotenone-treated macrophage cells, stimulation by LPS led to impairment in substrate-level phosphorylation (SLP) of in situ mitochondria, deduced by a reversal in the directionality of the adenine nucleotide translocase operation. In RAW-264.7 cells, the LPS-induced impairment in SLP was reversed by short-interfering RNA(siRNA)-but not scrambled siRNA-treatment directed against Irg1. LPS dose-dependently inhibited oxygen consumption rates (61-91%) and elevated glycolysis rates (>21%) in BMDM but not RAW-264.7 cells, studied under various metabolic conditions. In isolated mouse liver mitochondria treated with rotenone, itaconate dose-dependently (0.5-2 mM) reversed the operation of adenine nucleotide translocase, implying impairment in SLP, an effect that was partially mimicked by malonate. However, malonate yielded greater ADP-induced depolarizations (3-19%) than itaconate. We postulate that itaconate abolishes SLP due to 1) a "CoA trap" in the form of itaconyl-CoA that negatively affects the upstream supply of succinyl-CoA from the α-ketoglutarate dehydrogenase complex; 2) depletion of ATP (or GTP), which are required for the thioesterification by succinate-CoA ligase; and 3) inhibition of complex II leading to a buildup of succinate which shifts succinate-CoA ligase equilibrium toward ATP (or GTP) utilization. Our results support the notion that Irg1-expressing cells of macrophage lineage lose the capacity of mitochondrial SLP for producing itaconate during mounting of an immune defense.

[Pathogenic alterations within the neurofibromin gene in various cancers]. / A neurofibromin-1 gén kóros elváltozásai daganatos betegségekben.

The product of the neurofibromin gene (NF1) belongs to the family of tumor suppressor proteins. Neurofibromin plays important roles in the negative regulation of signaling pathways where the Ras oncogen is involved. The protein and gene names were derived from the disease, neurofibromatosis type 1 that is caused by germline mutations in NF1 and inherited by an autosomal dominant manner. Besides germline mutations, acquired, somatic mutations are also observed in NF1 in several malignant and benign tumors. NF1 mutations have been identified in a great number of solid tumors, leukemias and malignant skin lesions (e.g. melanoma). Such mutations define certain subsets of gliomas. More specifically, a molecular subset of glioblastomas, termed the mesenchymal subtype, is most frequently associated with somatic NF1 deletions and mutations. The aim of this survey is to provide an overview of the most frequent alterations in the NF1 gene with their effects on the function of the protein and the biology of the cell, as well as of the resultant diseases. Simultaneously, we give some insight into ongoing research studies investigating abnormalities of NF1.