Waveguide effects and implications for cardiac magnetic resonance elastography: A finite element study.

Magnetic resonance elastography (MRE) is increasingly being applied to thin or small structures in which wave propagation is dominated by waveguide effects, which can substantially bias stiffness results with common processing approaches. The purpose of this work was to investigate the importance of such biases and artifacts on MRE inversion results in: (i) various idealized 2D and 3D geometries with one or more dimensions that are small relative to the shear wavelength; and (ii) a realistic cardiac geometry. Finite element models were created using simple 2D geometries as well as a simplified and a realistic 3D cardiac geometry, and simulated displacements acquired by MRE from harmonic excitations from 60 to 220 Hz across a range of frequencies. The displacement wave fields were inverted with direct inversion of the Helmholtz equation with and without the application of bandpass filtering and/or the curl operator to the displacement field. In all geometries considered, and at all frequencies considered, strong biases and artifacts were present in inversion results when the curl operator was not applied. Bandpass filtering without the curl was not sufficient to yield accurate recovery. In the 3D geometries, strong biases and artifacts were present in 2D inversions even when the curl was applied, while only 3D inversions with application of the curl yielded accurate recovery of the complex shear modulus. These results establish that taking the curl of the wave field and performing a full 3D inversion are both necessary steps for accurate estimation of the shear modulus both in simple thin-walled or small structures and in a realistic cardiac geometry when using simple inversions that neglect the hydrostatic pressure term. In practice, sufficient wave amplitude, signal-to-noise ratio, and resolution will be required to achieve accurate results.

Order-disorder phase transition in an anhydrous pyrazole-based proton conductor: the enhancement of electrical transport properties.

The crystal structure of 1H-pyrazol-2-ium hydrogen oxalate has been studied at 100 K. It consists of two-dimensional layers built with one-dimensional chains that contain pyrazolium and oxalate acids bonded by N-HO and O-HO hydrogen bonds. According to the X-ray data and the Quantum Theory of Atoms in Molecules, it was shown that weak and moderate hydrogen bonds are present in the crystal at room temperature. The thermal stability was studied with the DSC, TGA, and DTG methods: three endothermic peaks are observed at 384, 420, and 469 K. Conductivity measurements have been performed in the temperature range from 300 to 433 K. At 383 K the pyrazole-oxalic acid framework loses its rigidity and the crystal undergoes an ordered-disordered phase transition. At this temperature, the value of the activation energy of proton conductivity changes from 1.14 to 2.31 eV. The proton conduction pathways and the transport mechanism have been studied with theoretical methods.

Predicting the diagnosis of autism in adults using the Autism-Spectrum Quotient (AQ) questionnaire.

BACKGROUND: Many adults with autism spectrum disorder (ASD) remain undiagnosed. Specialist assessment clinics enable the detection of these cases, but such services are often overstretched. It has been proposed that unnecessary referrals to these services could be reduced by prioritizing individuals who score highly on the Autism-Spectrum Quotient (AQ), a self-report questionnaire measure of autistic traits. However, the ability of the AQ to predict who will go on to receive a diagnosis of ASD in adults is unclear. METHOD: We studied 476 adults, seen consecutively at a national ASD diagnostic referral service for suspected ASD. We tested AQ scores as predictors of ASD diagnosis made by expert clinicians according to International Classification of Diseases (ICD)-10 criteria, informed by the Autism Diagnostic Observation Schedule-Generic (ADOS-G) and Autism Diagnostic Interview-Revised (ADI-R) assessments. RESULTS: Of the participants, 73% received a clinical diagnosis of ASD. Self-report AQ scores did not significantly predict receipt of a diagnosis. While AQ scores provided high sensitivity of 0.77 [95% confidence interval (CI) 0.72-0.82] and positive predictive value of 0.76 (95% CI 0.70-0.80), the specificity of 0.29 (95% CI 0.20-0.38) and negative predictive value of 0.36 (95% CI 0.22-0.40) were low. Thus, 64% of those who scored below the AQ cut-off were 'false negatives' who did in fact have ASD. Co-morbidity data revealed that generalized anxiety disorder may 'mimic' ASD and inflate AQ scores, leading to false positives. CONCLUSIONS: The AQ's utility for screening referrals was limited in this sample. Recommendations supporting the AQ's role in the assessment of adult ASD, e.g. UK NICE guidelines, may need to be reconsidered.

An 8-month history of meningitis in an extremely low birth weight infant? - Long-lasting Infection with Ureaplasma parvum.

INTRODUCTION: Ureaplasma spp. have been implicated in the pathogenesis of both preterm labor and neonatal morbidity including pneumonia and sepsis and the development of chronic lung disease of prematurity. Data on Ureaplasma meningitis are limited and partly controversially discussed. PATIENT: We report the unique case of a 9-month-old infant with progressive internal hydrocephalus of unknown origin and developmental delay due to a history of>200 days of inflammation of the central nervous system. The female extremely low birth weight infant had been referred to our hospital for ventriculoperitoneal shunt implantation. She had been born at 26+3 weeks of gestation with a birth weight of 940 g. With the exception of a moderate respiratory distress syndrome, postnatal period had been reported uneventful. However, internal hydrocephalus had become manifest at 4 weeks of postnatal age. Intraventricular hemorrhage had not been documented by cranial ultrasound and magnetic resonance imaging. Cerebrospinal fluid (CSF) analysis had repetitively revealed pronounced inflammation reflected by pleocytosis (50-86 leukocytes/µL, 60% lymphocytes), CSF protein levels of 578-1,026 mg/dL and undetectable CSF glucose. Although suggesting bacterial meningitis, microbial diagnostics had not been indicative, and empirical antibiotics had not affected the CSF findings. On admission to our hospital, CSF analysis still documented significant inflammation (125 leukocytes/µL, CSF protein 565 mg/dL, CSF glucose<2 mg/dL). RESULTS: Due to a prenatal history of cerclage, we initiated microbial diagnostics on Ureaplasma spp. and Mycoplasma hominis. U. parvum was detected in CSF by culture and PCR, no other pathogens were isolated. On intravenous treatment with chloramphenicol, CSF profile continuously normalized, and cultures and PCR became negative. Treatment was continued for 3 weeks, and the infant was discharged after uncomplicated ventriculoperitoneal shunt placement. During a 12-month observation period she has shown encouraging recovery. CONCLUSION: In preterm infants, in particular, internal hydrocephalus of unknown origin and sustained CSF inflammation are highly suggestive of Ureaplasma meningitis. Our case highlights that infection may escape detection if not explicitly considered, since microbial diagnosis requires complex media and PCR.

Multi-omics for studying and understanding polar life.

Polar ecosystems are experiencing amongst the most rapid rates of regional warming on Earth. Here, we discuss 'omics' approaches to investigate polar biodiversity, including the current state of the art, future perspectives and recommendations. We propose a community road map to generate and more fully exploit multi-omics data from polar organisms. These data are needed for the comprehensive evaluation of polar biodiversity and to reveal how life evolved and adapted to permanently cold environments with extreme seasonality. We argue that concerted action is required to mitigate the impact of warming on polar ecosystems via conservation efforts, to sustainably manage these unique habitats and their ecosystem services, and for the sustainable bioprospecting of novel genes and compounds for societal gain.

The impact of atraumatic fibrin sealant vs. staple mesh fixation in TAPP hernia repair on chronic pain and quality of life: results of a randomized controlled study.

BACKGROUND: Mesh reinforcement has become the standard of care in the open and laparoscopic repair of inguinal hernia. Chronic pain after inguinal hernia repair is often due to nerve injury by penetrating mesh fixation devices such as staples (ST), tacks, or sutures. In several studies on hernioplasty, atraumatic mesh fixation with fibrin sealant (FS) proved to be efficient in terms of fixation strength and elasticity. Unfortunately, most of these studies did not provide a standardized follow-up and assessment of the development of chronic pain (CP) and the quality of life (QoL). Therefore, a randomized controlled trial comparing CP and QoL after FS fixation of mesh with ST in transabdominal preperitoneal hernioplasty (TAPP) was performed at our department. The primary end point of our study was to assess the patient outcome by using a visual analog scale (VAS) and the short form 36 (SF-36). The evaluation of recurrence rates was the secondary aim. METHODS: According to the randomization, a macroporous mesh (TiMESH(®)) was fixed in group A (44 patients with 54 inguinal hernias) with FS (TISSEEL) or in group B (45 patients with 56 inguinal hernias) with ST (EMS(®) Stapler). The observation period was 1 year with regular clinical check ups and assessment of VAS and SF-36. RESULTS: Patient characteristics expressed by BMI, ASA scores, and Schumpelick hernia classification were similar in both treatment groups. In each group there was one recurrence within 8 (FS) and 9 months (ST) postsurgery. The mean preoperative pain values scored by VAS were 1.7 (range = 0-7.5) in the FS group and 2.2 (range = 0-6) in the ST group. Postoperative mean VAS scores measured at 1 year postsurgery were 0.4 (range = 0-3) in the FS group and 0.9 (range = 0-7.5) in the ST group. One year postsurgery there was no significant difference between the two groups with respect to the parameter pain in the SF-36 and VAS. CONCLUSION: Fibrin sealant fixation leads to a low rate of hernia recurrence and avoids tissue trauma. ST provide similar results in the hand of the expert but bear inherent risks of complications due to tissue perforation.

Effects of Toxoplasma gondii genotype and absence of host MAL/Myd88 on the temporal regulation of gene expression in infected microglial cells.

The majority of strains of Toxoplasma gondii belong to three distinct clonal lines known as types I, II, and III. The outcome of the immune response to infection is influenced by the parasite strain type. The goal of this study was to examine differences in the kinetics of gene expression in microglial cells infected with types I, II, or III of T. gondii. In addition, a requirement for the integrity of host Toll-like receptor (TLR) signaling in parasite-mediated changes in gene expression was evaluated. Wild type murine microglial cells infected with T. gondii displayed different kinetic patterns of pro-inflammatory cytokine expression that were dependent on the parasite strain type. In general, types II and III elicited higher sustained responses compared to type I which induced fluctuating patterns of cytokine gene expression. Contrary to this, differences in the induction of anti-apoptotic gene expression were minimal among the different type strains throughout infection. Experiments with cells lacking the TLR adaptor molecules MAL and Myd88 showed a dependency on these factors for the pro-inflammatory response but not the anti-apoptotic response. The results show that the outcome of gene expression in T. gondii-infected microglial cells is dependent on the parasite strain type in a time-dependent manner and is selective to particular subsets of genes. The induction of an anti-apoptotic response by T. gondii infection in the absence of TLR signaling reflects a complex level of modulation of host functions by the parasite.

Relationship between Shear Stiffness Measured by MR Elastography and Perfusion Metrics Measured by Perfusion CT of Meningiomas.

BACKGROUND AND PURPOSE: When managing meningiomas, intraoperative tumor consistency and histologic subtype are indispensable factors influencing operative strategy. The purposes of this study were the following: 1) to investigate the correlation between stiffness assessed with MR elastography and perfusion metrics from perfusion CT, 2) to evaluate whether MR elastography and perfusion CT could predict intraoperative tumor consistency, and 3) to explore the predictive value of stiffness and perfusion metrics in distinguishing among histologic subtypes of meningioma. MATERIALS AND METHODS: Mean tumor stiffness and relative perfusion metrics (blood flow, blood volume, and MTT) were calculated (relative to normal brain tissue) for 14 patients with meningiomas who underwent MR elastography and perfusion CT before surgery (cohort 1). Intraoperative tumor consistency was graded by a neurosurgeon in 18 patients (cohort 2, comprising the 14 patients from cohort 1 plus 4 additional patients). The correlation between tumor stiffness and perfusion metrics was evaluated in cohort 1, as was the ability of perfusion metrics to predict intraoperative tumor consistency and discriminate histologic subtypes. Cohort 2 was analyzed for the ability of stiffness to determine intraoperative tumor consistency and histologic subtypes. RESULTS: The relative MTT was inversely correlated with stiffness (P = .006). Tumor stiffness was positively correlated with intraoperative tumor consistency (P = .01), while perfusion metrics were not. Relative MTT significantly discriminated transitional meningioma from meningothelial meningioma (P = .04), while stiffness did not significantly differentiate any histologic subtypes. CONCLUSIONS: In meningioma, tumor stiffness may be useful to predict intraoperative tumor consistency, while relative MTT may potentially correlate with tumor stiffness and differentiate transitional meningioma from meningothelial meningioma.

Adverse effects of polyvinylidene fluoride-coated polypropylene mesh used for laparoscopic intraperitoneal onlay repair of incisional hernia.

BACKGROUND: Polyvinylidene fluoride-coated polypropylene meshes have been developed specifically for intraperitoneal onlay mesh repair. They combine a macroporous design with biomechanical characteristics compatible with the abdominal wall and are reported to have favourable antiadhesive properties. This retrospective study reports complications related to one of these materials, DynaMesh. METHODS: Twenty-nine patients underwent intraperitoneal onlay mesh repair with DynaMesh at one of two hospitals. Patients characteristics, surgical procedures and postoperative analgesia were comparable at both sites. RESULTS: Six patients developed DynaMesh-related complications that required surgical reintervention by laparotomy within 1 year of operation. Surgical reintervention was for adhesions in five patients and the mesh had to be explanted in three. One mesh was explanted because of early infection. Adhesions to DynaMesh were found in two patients who had surgery for unrelated reasons. CONCLUSION: Laparoscopic intraperitoneal onlay DynaMesh repair was associated with a high rate of complications.

Identification of genes that confer tumor cell resistance to the aurora B kinase inhibitor, AZD1152.

AZD1152 is a highly selective Aurora B kinase inhibitor currently undergoing Phase I and II clinical evaluation in patients with acute myelogenous leukemia and advanced solid malignancies. We have established two AZD1152-resistant cell lines from SW620 colon and MiaPaCa pancreatic carcinoma lines, which are >100-fold resistant to the active metabolite of AZD1152, AZD1152 HQPA and interestingly, cross-resistant to the pan-Aurora kinase inhibitor, VX-680/MK0457. Using whole-genome microarray analysis and comparative genomic hybridization, we were able to identify MDR1 and BCRP as the causative genes that underlie AZD1152 HQPA-resistance in these models. Furthermore, the upregulation of either of these genes is sufficient to render in vivo tumor growth insensitive to AZD1152. Finally, the upregulation of MDR1 or BCRP is predictive of tumor cell sensitivity to this agent, both in vitro and in vivo. The data provide a genetic basis for resistance to Aurora kinase inhibitors, which could be utilized to predict clinical response to therapy.

The epidemiology of primary systemic vasculitides involving small vessels in Crete (southern Greece): a comparison of older versus younger adult patients.

BACKGROUND: The frequency of primary systemic small vessel vasculitides (PSV) varies among different geographic regions and age categories. We studied PSV in patients from middle-eastern Crete (Greece), and compared clinical characteristics in younger (<65 years) versus older (> or = 65 years) adult patients. METHODS: The records of 67 patients (33 younger, 34 older adults) diagnosed with PSV during 1995-2003 who were referred to a mixed secondary/tertiary care University Hospital in Crete were reviewed. Data on clinical manifestations, diagnosis, therapy, and adverse outcomes (end stage renal disease, death) during a median follow-up of 6 (range 0-12) years were recorded. Multivariate regression analysis was applied to identify independent predictors for adverse outcomes. RESULTS: The overall annual incidence of PSV was 19.5/million (95% confidence interval [CI] 15.7-23.4), 48.9/million (95% CI 33.8-63.9) in older and 12.4/million (95% CI 7.7-17) in younger adults. Microscopic polyangiitis was more prevalent in older patients (65%) and Wegener's Granulomatosis in younger patients (52%). Thirty-one percent of older patients developed end-stage renal disease as compared to 11% of younger patients (p=0.103). Mortality rates were 60% in older patients and 19% in younger patients (p=0.001). In multivariate regression analysis age (Beta=0.33 per 1-year, p=0.005), serum creatinine (Beta=0.29 per 1-mg/dL, p=0.011), and lung involvement (Beta=0.36, p=0.002) at the time of diagnosis were independent predictors for end stage renal disease and/or death. CONCLUSION: This study documents increased frequency and significant mortality of PSV among older people in Crete, with MPA being the most prevalent type. Age, serum creatinine, and lung involvement are important predictors for adverse outcome in these patients.

Development of a novel equine whole transcript oligonucleotide GeneChip microarray and its use in gene expression profiling of normal articular-epiphyseal cartilage.

REASONS FOR PERFORMING STUDY: No large scale equine microarray is available commercially to allow genomic and transcriptional profiling of the majority of genes that would define the genetic basis of equine disease. OBJECTIVES: To generate a whole transcript target labelled GeneChip to interrogate the equine transcriptome and validate chip performance using RNA samples derived from organs, articular cells and normal cartilage. METHODS: Equine mRNA and selected equine gene sequences derived from perfect cross-hybridisation of equine RNA on human microarray GeneChips, were used to design a custom equine gene microarray. Sequence data were used as a template for generation of a glass-slide based 5'-3' multi-exon-encompassing gene chip. The microarray was characterised using RNA derived from organs including spleen, liver, brain and kidney, and RNA from cultured chondrocytes, cartilage, synovial tissue and stem cells, employing a whole transcript target labelling assay to sample mRNA across the 5'-3' spectrum. RESULTS: The custom microarray simultaneously interrogated over 12,300 equine specific genes. Probing the chip with mixtures of total RNA derived from parenchymatous organs and articular tissues resulted in 61.7 and 62.8% present calls, respectively. This gene chip provided expression information on up to 90% of the key molecules in important signalling, metabolic and development pathways. Cartilage specific matrix genes were abundantly expressed in normal articular cartilage, but surprisingly high levels of collagen types I, III, V and XI, reflected expression from the epiphyseal layers of maturing articular epiphyseal cartilage. CONCLUSION: An oligonucleotide microarray with over 12,300 probe sets was generated by uniquely combining a labelling strategy incorporating expressed sequence tags from the entire transcriptome and supplementing selected human sequences that cross-hybridised with the horse. Validation showed robust performance of the microarray. POTENTIAL RELEVANCE: This array may be a useful tool to elucidate the pathogenesis of equine diseases.

Paid employment and common mental disorders in 50-64-year olds: analysis of three cross-sectional nationally representative survey samples in 1993, 2000 and 2007.

AIMS: Associations between employment status and mental health are well recognised, but evidence is sparse on the relationship between paid employment and mental health in the years running up to statutory retirement ages using robust mental health measures. In addition, there has been no investigation into the stability over time in this relationship: an important consideration if survey findings are used to inform future policy. The aim of this study is to investigate the association between employment status and common mental disorder (CMD) in 50-64-year old residents in England and its stability over time, taking advantage of three national mental health surveys carried out over a 14-year period. METHODS: Data were analysed from the British National Surveys of Psychiatric Morbidity of 1993, 2000 and 2007. Paid employment status was the primary exposure of interest and CMD the primary outcome - both ascertained identically in all three surveys (CMD from the revised Clinical Interview Schedule). Multivariable logistic regression models were used. RESULTS: The prevalence of CMD was higher in people not in paid employment across all survey years; however, this association was only present for non-employment related to poor health as an outcome and was not apparent in those citing other reasons for non-employment. Odds ratios for the association between non-employment due to ill health and CMD were 3.05 in 1993, 3.56 in 2000, and 2.80 in 2007, after adjustment for age, gender, marital status, education, social class, housing tenure, financial difficulties, smoking status, recent physical health consultation and activities of daily living impairment. CONCLUSIONS: The prevalence of CMD was higher in people not in paid employment for health reasons, but was not associated with non-employment for other reasons. Associations had been relatively stable in strength from 1993 to 2007 in those three cross-sectional nationally representative samples.

Vibration safety limits for magnetic resonance elastography.

Magnetic resonance elastography (MRE) has been demonstrated to have potential as a clinical tool for assessing the stiffness of tissue in vivo. An essential step in MRE is the generation of acoustic mechanical waves within a tissue via a coupled mechanical driver. Motivated by an increasing volume of human imaging trials using MRE, the objectives of this study were to audit the vibration amplitude of exposure for our IRB-approved human MRE studies, to compare these values to a conservative regulatory standard for vibrational exposure and to evaluate the applicability and implications of this standard for MRE. MRE displacement data were examined from 29 MRE exams, including the liver, brain, kidney, breast and skeletal muscle. Vibrational acceleration limits from a European Union directive limiting occupational exposure to whole-body and extremity vibrations (EU 2002/44/EC) were adjusted for time and frequency of exposure, converted to maximum displacement values and compared to the measured in vivo displacements. The results indicate that the vibrational amplitudes used in MRE studies are below the EU whole-body vibration limit, and the EU guidelines represent a useful standard that could be readily accepted by Institutional Review Boards to define standards for vibrational exposures for MRE studies in humans.

Visualizing nuclei in skin cryosections: viable options to 4'6-diamidino-2-phenylindol for confocal laser microscopy.

BACKGROUND: Visualization of nuclei in skin (cryo-) sections is essential for both, rapid overview and reliable orientation within skin samples. Therefore, nuclear staining is a very common counterstain for immunohistochemical studies of human skin as this nuclear staining precisely depicts the cellular distribution within the epidermis. Moreover, it clearly shows the epidermal-dermal border as well as the transition zone between the living and the cornified layers of the epidermis. For standard epifluorescence microscopy, 4'6-diamidino-2-phenylindol (DAPI) is commonly used. For confocal laser scanning microscopy (CLSM), however, DAPI is often not suitable because its excitation maximum is in the ultraviolet (UV) range (Ex(max) 359 nm) when bound to DNA, and UV lasers and the corresponding optics are not part of CLSM standard configuration. METHODS: In order to find an adequate DAPI substitute that is excitable with standard visible light lasers, the following nuclear stains were tested: LOLOt-1 iodide (Ex(max) 565 nm), TOTO s -3 iodide (Ex(max) 642 nm), LO-PROt-1 iodide (Ex(max) 567 nm), SYTO s 84 (Ex(max) 567 nm), SYTO s 85 (Ex(max) 567 nm), SYTOX s Green (Ex(max) 488 nm) and SYTOX s Orange (Ex(max) 547 nm), Propidium iodide (Ex(max) 535 nm). Besides optimal concentration and incubation time, following criteria were also evaluated: photobleaching, background, e.g. cytoplasmic staining of RNA, and sensitivity to different fixation conditions (unfixed, IEM fixation, PLP fixation and PFA fixation). RESULTS: According to these criteria Sytox s Green showed the best overall staining score and can be used for variously fixed skin samples and shows a distinct and stable green nuclear fluorescence.

The assessment of quality of life in a trial on lightweight mesh fixation with fibrin sealant in transabdominal preperitoneal hernia repair.

BACKGROUND: Chronic pain is a major concern in open and laparoscopic hernia repair. Study groups have adopted a variety of tools to assess postoperative (postOP) pain and quality of life (QoL). Unfortunately, modifications of existing tests and self-designed questionnaires are common, yielding unvalidated results and making comparison of data difficult. The aim of this study was to assess the QoL in transabdominal preperitoneal mesh repair (TAPP) with fibrin sealant (FS) for lightweight mesh fixation, applying the standardised Short Form 36 (SF36) questionnaire in its unmodified design. The SF36 has already been validated and implemented in a large number of studies. In this trial the physical-health-component summary measure (PHM), summarising the physical health-related scales, served as the primary outcome parameter. MATERIALS AND METHODS: After informed written consent was obtained, TAPP with fibrin mesh sealing was performed in 11 non-selected consecutive patients by a single surgeon. A direct control group (e.g. TAPP with staples) was not enrolled, because a favourable change in the QoL in patients subjected to the mesh sealing approach was the tested hypothesis and not the comparison of techniques. The macroporous mesh (TI-Mesh, GfE, Germany) was fixed with 1 ml of FS (FS, Tisseel, Tissucol, Baxter Biosciences, Austria), and the QoL and pain were assessed preoperatively and 1 year postOP using the SF36 survey and the visual analogue score (VAS). RESULTS: After 12 months, recurrences or complications were observed. The analysis of the unmodifed SF36 revealed a highly significant improvement in the PHM, based on significant changes of all physical-health-related scales. The scale 'social functioning' (SOCIAL), which belongs to the mental-health-related scale, had also significantly improved. The VAS was significantly reduced after 1 year. CONCLUSIONS: Despite a small number of patients (n = 11), a strikingly significant improvement in physical health and reduction of pain was detected with the unmodified SF36 and the VAS 1 year after TAPP repair with fibrin-sealed lightweight meshes. We suggest the use of the unmodified SF36 for QoL in hernia repair in order to assess all aspects of recovery (physical and mental) and to facilitate comparison of data.

MR Elastography Analysis of Glioma Stiffness and IDH1-Mutation Status.

BACKGROUND AND PURPOSE: Our aim was to noninvasively evaluate gliomas with MR elastography to characterize the relationship of tumor stiffness with tumor grade and mutations in the isocitrate dehydrogenase 1 (IDH1) gene. MATERIALS AND METHODS: Tumor stiffness properties were prospectively quantified in 18 patients (mean age, 42 years; 6 women) with histologically proved gliomas using MR elastography from 2014 to 2016. Images were acquired on a 3T MR imaging unit with a vibration frequency of 60 Hz. Tumor stiffness was compared with unaffected contralateral white matter, across tumor grade, and by IDH1-mutation status. The performance of the use of tumor stiffness to predict tumor grade and IDH1 mutation was evaluated with the Wilcoxon rank sum, 1-way ANOVA, and Tukey-Kramer tests. RESULTS: Gliomas were softer than healthy brain parenchyma, 2.2 kPa compared with 3.3 kPa (P < .001), with grade IV tumors softer than grade II. Tumors with an IDH1 mutation were significantly stiffer than those with wild type IDH1, 2.5 kPa versus 1.6 kPa, respectively (P = .007). CONCLUSIONS: MR elastography demonstrated that not only were gliomas softer than normal brain but the degree of softening was directly correlated with tumor grade and IDH1-mutation status. Noninvasive determination of tumor grade and IDH1 mutation may result in improved stratification of patients for different treatment options and the evaluation of novel therapeutics. This work reports on the emerging field of "mechanogenomics": the identification of genetic features such as IDH1 mutation using intrinsic biomechanical information.

Comparison of structural, thermal and proton conductivity properties of micro- and nanocelluloses.

Our search for a cellulose-based proton conducting material is continued. This paper presents selected physicochemical properties of cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs) together with cellulose microcrystals (CMCs) and cellulose microfibrils (CMFs), determined by X-ray diffraction (XRD), thermogravimetric analysis (TGA + DTA), differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FT-IR), and electrical impedance spectroscopy (EIS). The CNCs and CNFs were studied in the forms of powder and film. They were produced in the process of transition metal catalyzed oxidative process or by TEMPO-mediated oxidation. It has been shown that regardless of the production method and the form of the sample the celluloses retained the cellulose Iß crystalline structure, the cellulose films showed similar thermal properties in the relevant temperature range from room temperature to about 200 °C, and the TEMPO-oxidized CNF film showed the highest proton conductivity when compared with those of the other samples studied.

Adaptation to bacterial lipopolysaccharide controls lipopolysaccharide-induced tumor necrosis factor production in rabbit macrophages.

These experiments provide an explanation for the observation that two intravenous injections of lipopolysaccharide (LPS) spaced 5 h apart in rabbits cause tumor necrosis factor/cachectin (TNF) levels to rise in the blood only after the first LPS injection. Herein we show that treatment of elicited peritoneal exudate rabbit macrophages (PEM) with two doses of LPS given 9 h apart results in a marked reduction in TNF production by the second LPS exposure. This state of hyporesponsiveness is a result of adaptation to LPS, is induced by LPS concentrations that are 1,000-fold less than required to induce TNF production (picograms vs. nanograms), is characterized by a decrease in LPS-induced TNF mRNA without any change in TNF mRNA half-life, is not changed by including indomethacin in cultures, and is specific for LPS since LPS-adapted cells display a TNF response to heat-killed Staphylococcus aureus that is at least as good as that observed in control PEM.