Selective inhibition of prostaglandin biosynthesis by gold salts and phenylbutazone

Gold salts and phenylbutazone selectively inhibit the synthesis of PGF_2α and PGE₂ respectively. Lowered production of one prostaglandin species is accompanied by an increased production of the other. Selective inhibition by these drugs was observed in the presence of adrenaline, reduced glutathione and copper sulphate under conditions when most anti-inflammatory compounds inhibited PGE₂ and PGF_2α syntheses equally. It is postulated that selective inhibitors may have a different mode of action and beneficial effects may be related to the endogenous ratio of PGE to PGF required for normal function.     

Reproducibility of Volumetric Computed Tomography of Stable Small Pulmonary Nodules with Implications on Estimated Growth Rate and Optimal Scan Interval

Purpose

To use clinically measured reproducibility of volumetric CT (vCT) of lung nodules to estimate error in nodule growth rate in order to determine optimal scan interval for patient follow-up.

Methods

We performed quantitative vCT on 89 stable non-calcified nodules and 49 calcified nodules measuring 3–13 mm diameter in 71 patients who underwent 3–9 repeat vCT studies for clinical evaluation of pulmonary nodules. Calculated volume standard deviation as a function of mean nodule volume was used to compute error in estimated growth rate. This error was then used to determine the optimal patient follow-up scan interval while fixing the false positive rate at 5%.

Results

Linear regression of nodule volume standard deviation versus the mean nodule volume for stable non-calcified nodules yielded a slope of 0.057±0.002 (r² = 0.79, p<0.001). For calcified stable nodules, the regression slope was 0.052±0.005 (r² = 0.65, p = 0.03). Using this with the error propagation formula, the optimal patient follow-up scan interval was calculated to be 81 days, independent of initial nodule volume.

Conclusions

Reproducibility of vCT is excellent, and the standard error is proportional to the mean calculated nodule volume for the range of nodules examined. This relationship constrains statistical certainty of vCT calculated doubling times and results in an optimal scan interval that is independent of the initial nodule volume.     

Radiation of the Tnt1 retrotransposon superfamily in three Solanaceae genera

Background  

Tnt1 was the first active plant retrotransposon identified in tobacco after nitrate reductase gene disruption. The Tnt1 superfamily comprises elements from Nicotiana (Tnt1 and Tto1) and Lycopersicon (Retrolyc1 and Tlc1) species. The study presented here was conducted to characterise Tnt1-related sequences in 20 wild species of Solanum and five cultivars of Solanum tuberosum.     

Role of STRAP in regulating GSK3β function and Notch3 stabilization

Glycogen synthase kinase 3β (GSK3β) can regulate a broad range of cellular processes in a variety of cell types and tissues through its ability to phosphorylate its substrates in a cell- and time-specific manner. Although it is known that Axin and presenilin help to recruit β-catenin/Smad3 and tau protein to GSK3β, respectively, it is not clear how many of the other GSK3β substrates are recruited to it. Here, we have established the binding of GSK3β with a novel scaffold protein, STRAP, through its WD40 domains. In a new finding, we have observed that STRAP, GSK3β and Axin form a ternary complex together. We show for the first time that intracellular fragment of Notch3 (ICN3) binds with GSK3β through the ankyrin repeat domain. This binding between STRAP and GSK3β is reduced by small-molecule inhibitors of GSK3β. Further studies revealed that STRAP also binds ICN3 through the ankyrin repeat region, and this binding is enhanced in a proteasomal inhibition-dependent manner. In vivo ubiquitination studies indicate that STRAP reduces ubiquitination of ICN3, suggesting a role of STRAP in stabilizing ICN3. This is supported by the fact that STRAP and Notch3 are co-upregulated and co-localized in 59% of non-small cell lung cancers, as observed in an immunohistochemical staining of tissue microarrays. These results provide a potential mechanism by which STRAP regulates GSK3β function and Notch3 stabilization and further support the oncogenic functions of STRAP.Key words: STRAP, GSK3β, Notch3, axin, lung cancer, ubiquitination     

Methods for peptide and protein quantitation by liquid chromatography-multiple reaction monitoring mass spectrometry

Liquid chromatography-multiple reaction monitoring mass spectrometry of peptides using stable isotope dilution (SID) provides a powerful tool for targeted protein quantitation. However, the high cost of labeled peptide standards for SID poses an obstacle to multiple reaction monitoring studies. We compared SID to a labeled reference peptide (LRP) method, which uses a single labeled peptide as a reference standard for all measured peptides, and a label-free (LF) approach, in which quantitation is based on analysis of un-normalized peak areas for detected MRM transitions. We analyzed peptides from the Escherichia coli proteins alkaline phosphatase and β-galactosidase spiked into lysates from human colon adenocarcinoma RKO cells. We also analyzed liquid chromatography-multiple reaction monitoring mass spectrometry data from a recently published interlaboratory study by the National Cancer Institute Clinical Proteomic Technology Assessment for Cancer network (Addona et al. (2009) Nat. Biotechnol. 27: 633-641), in which unlabeled and isotopically labeled synthetic peptides or their corresponding proteins were spiked into human plasma. SID displayed the highest correlation coefficients and lowest coefficient of variation in regression analyses of both peptide and protein spike studies. In protein spike experiments, median coefficient of variation values were about 10% for SID and 20-30% for LRP and LF methods. Power calculations indicated that differences in measurement error between the methods have much less impact on measured protein expression differences than biological variation. All three methods detected significant (p < 0.05) differential expression of three endogenous proteins in a test set of 10 pairs of human lung tumor and control tissues. Further, the LRP and LF methods both detected significant differences (p < 0.05) in levels of seven biomarker candidates between tumors and controls in the same set of lung tissue samples. The data indicate that the LRP and LF methods provide cost-effective alternatives to SID for many quantitative liquid chromatography-multiple reaction monitoring mass spectrometry applications.     

Biomechanical analysis of movement strategies in human forward trunk bending. II. Experimental study

 The large mass of the human upper trunk, its elevated position during erect stance, and the small area limited by the size of the feet, stress the importance of equilibrium control during trunk movements. The objective of the present study was to perform a biomechanical analysis of fast forward trunk movements in order to understand the coordination between movement and posture. The analysis is based on a comparison between experimentally observed bending and hypothetical “optimal bending” performed on an infinitely narrow support, as presented in a companion paper. The experimental data were obtained from 16 subjects who performed fast forward bending while standing on a wide platform or on a narrow beam. The analysis is performed by decomposition of the movement into three dynamically independent components, each representing a movement along one of the three eigenvectors of the motion equation. The eigenmovements are termed “hip”, “ankle”, and “knee” eigenmovements, according to the dominant joint. The experimentally observed movement is characterized mainly by the hip and ankle eigenmovements, whereas the knee eigenmovement is negligible. Similarly to the “optimal bending” the ankle eigenmovement starts earlier and lasts longer than the hip eigenmovement. An early forward acceleration of the center of gravity in the ankle eigenmovement is caused by anticipatory changes in the ankle joint torque. This clarifies the role of the early tibialis anterior burst and/or soleus inhibition usually observed in electromyographic recordings during forward bending. The results suggest that the hip and the ankle eigenmovements can be treated as independently controlled motion units aimed at functionally different behavioral goals: the bending per se and postural adjustment. It is proposed that the central nervous system has to control these motion units sequentially in order to perform the movement and maintain equilibrium. It is also suggested that the hip and ankle eigenmovements can be regarded as a biomechanical background for the hip and ankle strategies introduced by Horak and Nashner (1986) on the basis of electromyographic recordings and kinematic patterns in response to postural perturbations. Received: 1 July 1999 / Accepted in revised form: 23 October 2000     

Recurrent Genomic Gains in Preinvasive Lesions as a Biomarker of Risk for Lung Cancer

Lung carcinoma development is accompanied by field changes that may have diagnostic significance. We have previously shown the importance of chromosomal aneusomy in lung cancer progression. Here, we tested whether genomic gains in six specific loci, TP63 on 3q28, EGFR on 7p12, MYC on 8q24, 5p15.2, and centromeric regions for chromosomes 3 (CEP3) and 6 (CEP6), may provide further value in the prediction of lung cancer. Bronchial biopsy specimens were obtained by LIFE bronchoscopy from 70 subjects (27 with prevalent lung cancers and 43 individuals without lung cancer). Twenty six biopsies were read as moderate dysplasia, 21 as severe dysplasia and 23 as carcinoma in situ (CIS). Four-micron paraffin sections were submitted to a 4-target FISH assay (LAVysion, Abbott Molecular) and reprobed for TP63 and CEP 3 sequences. Spot counts were obtained in 30–50 nuclei per specimen for each probe. Increased gene copy number in 4 of the 6 probes was associated with increased risk of being diagnosed with lung cancer both in unadjusted analyses (odds ratio = 11, p<0.05) and adjusted for histology grade (odds ratio = 17, p<0.05). The most informative 4 probes were TP63, MYC, CEP3 and CEP6. The combination of these 4 probes offered a sensitivity of 82% for lung cancer and a specificity of 58%. These results indicate that specific cytogenetic alterations present in preinvasive lung lesions are closely associated with the diagnosis of lung cancer and may therefore have value in assessing lung cancer risk.     

Static and dynamic postural control in long-term microgravity: evidence of a dual adaptation

The adaptation of dynamicmovement-posture coordination during forward trunk bending wasinvestigated in long-term weightlessness. Three-dimensionalmovement analysis was carried out in two astronauts during a 4-momicrogravity exposure. The principal component analysis was applied tojoint-angle kinematics for the assessment of angular synergies. Theanteroposterior center of mass (CM) displacement accompanying trunkflexion was also quantified. The results reveal that subjects kepttypically terrestrial strategies of movement-posture coordination. Thetemporary disruption of joint-angular synergies observed at subjects'first in-flight session was promptly recovered when repetitive sessionsin flight were analyzed. The CM anteroposterior shift was consistently<3-4 cm, suggesting that subjects could dynamically control theCM position throughout the whole flight. This is in contrast to theobserved profound microgravity-induced disruption of the quasi-staticbody orientation and initial CM positioning. Although this study wasbased on only two subjects, evidence is provided that static anddynamic postural control might be under two separate mechanisms,adapting with their specific time course to the constraints of microgravity.