Serine residues 994 and 1023/25 are important for insulin receptor kinase inhibition by protein kinase C isoforms beta2 and theta

AIMS/HYPOTHESIS: Inhibition of the signalling function of the human insulin receptor (HIR) is one of the principle mechanisms which induce cellular insulin resistance. It is speculated that serine residues in the insulin receptor beta-subunit are involved in receptor inhibition either as inhibitory phosphorylation sites or as part of receptor domains which bind inhibitory proteins or tyrosine phosphatases. As reported earlier we prepared 16 serine to alanine point mutations of the HIR and found that serine to alanine mutants HIR-994 and HIR-1023/25 showed increased tyrosine autophosphorylation when expressed in human embryonic kidney (HEK) 293 cells. In this study we examined whether these mutant receptors have a different susceptibility to inhibition by serine kinases or an altered tyrosine kinase activity. METHODS: Tyrosine kinase assay and transfection studies. RESULTS: In an in vitro kinase assay using IRS-1 as a substrate we could detect a higher intrinsic tyrosine kinase activity of both receptor constructs. Additionally, a higher capacity to phosphorylate the adapter protein Shc in intact cells was seen. To test the inhibition by serine kinases, the receptor constructs were expressed in HEK 293 cells together with IRS-1 and protein kinase C isoforms beta2 and theta. Phorbol ester stimulation of these cells reduced wild-type receptor autophosphorylation to 58 % or 55 % of the insulin simulated state, respectively. This inhibitory effect was not observed with HIR-994 and HIR-1023/25, although all other tested HIR mutants showed similar inhibition induced by protein kinase C. CONCLUSION/INTERPRETATION: The data suggest that the HIR-domain which contains the serine residues 994 and 1023/25 is important for the inhibitory effect of protein kinase C isoforms beta2 and theta on insulin receptor autophosphorylation.

Sleep quality, the neglected outcome variable in clinical studies focusing on locomotor system; a construct validation study

In addition to general health and pain, sleep is highly relevant to judging the well-being of an individual. Of these three important outcome variables, however, sleep is neglected in most outcome studies.Sleep is a very important resource for recovery from daily stresses and strains, and any alteration of sleep will likely affect mental and physical health, especially during disease. Sleep assessment therefore should be standard in all population-based or clinical studies focusing on the locomotor system. Yet current sleep assessment tools are either too long or too specific for general use.

Efficacy of experimental treatments compared with standard treatments in non-inferiority trials: a meta-analysis of randomized controlled trials

Background There is concern that non-inferiority trials might be deliberately designed to conceal that a new treatment is less effective than a standard treatment. In order to test this hypothesis we performed a meta-analysis of non-inferiority trials to assess the average effect of experimental treatments compared with standard treatments. Methods One hundred and seventy non-inferiority treatment trials published in 121 core clinical journals were included. The trials were identified through a search of PubMed (1991 to 20 February 2009). Combined relative risk (RR) from meta-analysis comparing experimental with standard treatments was the main outcome measure. Results The 170 trials contributed a total of 175 independent comparisons of experimental with standard treatments. The combined RR for all 175 comparisons was 0.994 [95% confidence interval (CI) 0.978–1.010] using a random-effects model and 1.002 (95% CI 0.996–1.008) using a fixed-effects model. Of the 175 comparisons, experimental treatment was considered to be non-inferior in 130 (74%). The combined RR for these 130 comparisons was 0.995 (95% CI 0.983–1.006) and the point estimate favoured the experimental treatment in 58% (n = 76) and standard treatment in 42% (n = 54). The median non-inferiority margin (RR) pre-specified by trialists was 1.31 [inter-quartile range (IQR) 1.18–1.59]. Conclusion In this meta-analysis of non-inferiority trials the average RR comparing experimental with standard treatments was close to 1. The experimental treatments that gain a verdict of non-inferiority in published trials do not appear to be systematically less effective than the standard treatments. Importantly, publication bias and bias in the design and reporting of the studies cannot be ruled out and may have skewed the study results in favour of the experimental treatments. Further studies are required to examine the importance of such bias.

How reliable are Hounsfield-unit measurements in forensic radiology?

OBJECTIVE: To assess the reliability of computed tomography (CT) numbers, also known as Hounsfield-units (HU) in the differentiation and identification of forensically relevant materials and to provide instructions to improve the reproducibility of HU measurements in daily forensic practice. MATERIALS AND METHODS: We scanned a phantom containing non-organic materials (glass, rocks and metals) on three different CT scanners with standardized parameters. The t-test was used to assess the influence of the scanner, the size and shape of different types of regions-of-interest (ROI), the composition and shape of the object, and the reader performance on HU measurements. Intra-class correlation coefficient was used to assess intra- and inter-reader reliability. RESULTS: HU values did not change significantly as a function of ROI-shape or -size (p>0.05). Intra-reader reliability reached ICC values >0.929 (p<0.001). Inter-reader reliability was also excellent with an ICC of 0.994 (p<0.001). Four of seven objects yielded significantly different CT numbers at different levels within the object (p<0.05). In 6/7 objects the HU changed significantly from CT scanner to CT scanner (p<0.05). CONCLUSION: Reproducible CT number measurements can be achieved through correct ROI-placement and repeat measurements within the object of interest. However, HU may differ from CT-scanner to CT-scanner. In order to obtain comparable CT numbers we suggest that a dedicated Forensic Reference Phantom be developed.

Expression patterns of Bmi-1 and p16 significantly correlate with overall, disease-specific, and recurrence-free survival in oropharyngeal squamous cell carcinoma

BACKGROUND: The objective of this study was to link expression patterns of B-cell-specific Moloney murine leukemia virus integration site 1 (Bmi-1) and p16 to patient outcome (recurrence and survival) in a cohort of 252 patients with oral and oropharyngeal squamous cell cancer (OSCC). METHODS: Expression levels of Bmi-1 and p16 in samples from 252 patients with OSCC were evaluated immunohistochemically using the tissue microarray method. Staining intensity was determined by calculating an intensity reactivity score (IRS). Staining intensity and the localization of expression within tumor cells (nuclear or cytoplasmic) were correlated with overall, disease-specific, and recurrence-free survival. RESULTS: The majority of cancers were localized in the oropharynx (61.1%). In univariate analysis, patients who had OSCC and strong Bmi-1 expression (IRS >10) had worse outcomes compared with patients who had low and moderate Bmi-1 expression (P = .008; hazard ratio [HR], 1.82; 95% confidence interval [CI], 1.167-2.838); this correlation was also observed for atypical cytoplasmic Bmi-1 expression (P = .001; HR, 2.164; 95% CI, 1.389-3.371) and for negative p16 expression (P < .001; HR, 0.292; 95% CI, 0.178-0.477). The combination of both markers, as anticipated, had an even stronger correlation with overall survival (P < .001; HR, 8.485; 95% CI, 4.237-16.994). Multivariate analysis demonstrated significant results for patients with oropharyngeal cancers, but not for patients with oral cavity tumors: Tumor classification (P = .011; HR, 1.838; 95%CI, 1.146-2.947) and the combined marker expression patterns (P < .001; HR, 6.254; 95% CI, 2.869-13.635) were correlated with overall survival, disease-specific survival (tumor classification: P = .002; HR, 2.807; 95% CI, 1.477-5.334; combined markers: P = .002; HR, 5.386; 95% CI, 1.850-15.679), and the combined markers also were correlated with recurrence-free survival (P = .001; HR, 8.943; 95% CI, 2.562-31.220). CONCLUSIONS: Cytoplasmic Bmi-1 expression, an absence of p16 expression, and especially the combination of those 2 predictive markers were correlated negatively with disease-specific and recurrence-free survival in patients with oropharyngeal cancer. Therefore, the current results indicate that these may be applicable as predictive markers in combination with other factors to select patients for more aggressive treatment and follow-up. Cancer 2011;. © 2011 American Cancer Society.

Occurrence, finger printing and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in the Chenab River, Pakistan

Seventeen polycyclic aromatic hydrocarbons (PAHs) were studied in surface waters (including particulate phase) from the Chenab River, Pakistan and ranged from 289-994 and 437-1290 ng l-1 in summer and winter (2007-09), respectively. Concentrations for different ring-number PAHs followed the trend: 3-rings > 2-rings > 4-rings > 5-rings > 6-rings. The possible sources of PAHs are identified by calculating the indicative ratios; appropriating petrogenic sources of PAHs in urban and sub-urban regions with pyrogenic sources in agricultural region. Factor analysis based on principal component analysis identified the origins of PAHs from industrial activities, coal and trash burning in agricultural areas and municipal waste disposal from surrounding urban and sub-urban areas via open drains into the riverine ecosystem. Water quality guidelines and toxic equivalent factors highlighted the potential risk of low molecular weight PAHs to the aquatic life of the Chenab River. The flux estimated for PAHs contaminants from the Chenab River to the Indus River was >50 tons/year.

The evolutionary diversification of parrots supports a taxon pulse model with multiple trans-oceanic dispersal events and local radiations

Vicariance is thought to have played a major role in the evolution of modern parrots. However, as the relationships especially of the African taxa remained mostly unresolved, it has been difficult to draw firm conclusions about the roles of dispersal and vicariance. Our analyses using the broadest taxon sampling of old world parrots ever based on 3219 bp of three nuclear genes revealed well-resolved and congruent phylogenetic hypotheses. Agapornis of Africa and Madagascar was found to be the sister group to Loriculus of Australasia and Indo-Malayasia and together they clustered with the Australasian Loriinae, Cyclopsittacini and Melopsittacus. Poicephalus and Psittacus from mainland Africa formed the sister group Of the Neotropical Arini and Coracopsis from Madagascar and adjacent islands may be the closest relative of Psittrichas from New Guinea. These biogeographic relationships are best explained by independent colonization of the African continent via trans-oceanic dispersal from Australasia and Antarctica in the Paleogene following what may have been vicariance events in the late Cretaceous and/or early Paleogene. Our data support a taxon pulse model for the diversification of parrots whereby trans-oceanic dispersal played a more important role than previously thought and was the prerequisite for range expansion into new continents. (C) 2009 Elsevier Inc. All rights reserved

Do invasive species perform better in their new ranges?

A fundamental assumption in invasion biology is that most invasive species exhibit enhanced performance in their introduced range relative to their home ranges. This idea has given rise to numerous hypotheses explaining “invasion success” by virtue of altered ecological and evolutionary pressures. There are surprisingly few data, however, testing the underlying assumption that the performance of introduced populations, including organism size, reproductive output, and abundance, is enhanced in their introduced compared to their native range. Here, we combined data from published studies to test this hypothesis for 26 plant and 27 animal species that are considered to be invasive. On average, individuals of these 53 species were indeed larger, more fecund, and more abundant in their introduced ranges. The overall mean, however, belied significant variability among species, as roughly half of the investigated species (N = 27) performed similarly when compared to conspecific populations in their native range. Thus, although some invasive species are performing better in their new ranges, the pattern is not universal, and just as many are performing largely the same across ranges.

The Forensic Reference Phantom-a new tool for quality assurance of attenuation measurements in forensic radiology

Introduction The purpose of this paper is to present the technical specifications of the Forensic Reference Phantom (FRP), to test its behavior relative to organic test materials, and discuss potential applications of the phantom in forensic radiology. Materials and method The FRP prototype is made of synthetic materials designed to simulate the computed tomography (CT) attenuation of water. It has six bore holes that accommodate multiuse containers. These containers were filled with test materials and scanned at 80 kVp, 120 kVp, and 140 kVp. X-ray attenuation was measured by two readers. Intra- and inter-reader reliability was assessed using the intra-class correlation coefficient (ICC). Significance levels between mean CT numbers at 80 kVp, 120 kVp, and 140 kVp were assessed with the Friedman-test. The T-test was used to assess significance levels between the FRP and water. Results Overall mean CT numbers ranged from −3.0–3.7HU for the FRP; −1000.3–−993.5HU for air; −157.7– −108.1HU for oil; 35.5–42.0HU for musle tissue; and 1301.5–2354.8HU for cortical bone. Inter-reader and intra-reader reliability were excellent (ICC>0.994; and ICC=0.999 respectively). CT numbers were significantly different at different energy levels. There was no significant difference between the attenuation of the FRP and water. Conclusions The FRP is a new tool for quality assurance and research in forensic radiology. The mean CT attenuation of the FRP is equivalent to water. The phantom can be scanned during routine post-mortem CT to assess the composition of unidentified objects. In addition, the FRP may be used to investigate new imaging algorithms and scan protocols in forensic radiology.