A randomized, rater-blinded, crossover study comparing the clinical efficacy of Ritalin® LA (methylphenidate) treatment in children with attention-deficit hyperactivity disorder under different breakfast conditions over 2 weeks

Several extended-release methylphenidate medications are available for treatment of children with ADHD. Pharmacokinetic investigations suggest that the serum levels of methylphenidate are partially altered when the medication is taken without breakfast. Clinical data comparing different breakfast situations are missing. In this study, different breakfast compositions and their influence on treatment with Ritalin LA are investigated. A total of 150 patients were enrolled in a rater-blinded, randomized crossover trial that compared a minimal breakfast with a standard breakfast in patients under stable treatment with Ritalin LA. Ratings for clinical efficacy were carried out after 1 week by teachers and parents (FBB-ADHS), as well as physicians (CGI). Additionally, a math test was administered to the patients. Of the total patients, 144 finished the trial with a breakfast compliance of 93%. All of the clinical rating scales showed consistently no difference between the two breakfast conditions. Non-inferiority of minimal breakfast versus standard breakfast was shown to be statistically significant (FBB-AHDS(Teacher): 0.97 with minimal breakfast, 1.01 with standard breakfast, P < 0.0001). The clinical efficacy of Ritalin LA is not influenced by breakfast and works independently of food intake.     

Novel cationic vesicle platform derived from vernonia oil for efficient delivery of DNA through plant cuticle membranes

Novel cationic amphiphilic compounds were prepared from vernonia oil, a natural epoxidized triglyceride, and studied with respect to vesicle formation, encapsulation of biomaterials such as DNA, and their physical stability and transport through isolated plant cuticle membranes. The amphiphiles studied were a single-headed compound III (a quaternary ammonium head group with two alkyl chains) and a triple-headed compound IV, which is essentially three molecules of compound III bound together through a glycerol moiety. Vesicles of the two amphiphiles, prepared by sonication in water and solutions of uranyl acetate or the herbicide 2,4-D (2,4-dichloropenoxy acetic acid), were examined by TEM, SEM, AFM, and confocal laser systems and had a spherical shape which encapsulated the solutes with diameters between 40 and 110 nm. Vesicles from amphiphile IV could be made large enough to encapsulate a condensed 5.2kb DNA plasmid (pJD328). Vesicles of amphiphile IV were also shown to pass intact across isolated plant cuticle membranes and the rate of delivery of encapsulated radio-labeled 2,4-D through isolated plant cuticle membranes obtained with these vesicles was clearly greater in comparison to liposomes prepared from dipalmitopyl phosphatidylcholine (DPPC) and the control, nonencapsulated 2,4-D. Vesicles from amphiphiles III and IV were found to be more stable than those of liposomes from DPPC. The data indicate the potential of vesicles prepared from the novel amphiphile IV to be a relatively efficient nano-scale delivery system to transport DNA and other bioactive agents through plant biological barriers. This scientific approach may open the way for further development of efficient in vivo plant transformation systems.     

The likely impact of elevated [CO2], nitrogen deposition, increased temperature and management on carbon sequestration in temperate and boreal forest ecosystems: a literature review

Temperate and boreal forest ecosystems contain a large part of the carbon stored on land, in the form of both biomass and soil organic matter. Increasing atmospheric [CO2], increasing temperature, elevated nitrogen deposition and intensified management will change this C store. Well documented single-factor responses of net primary production are: higher photosynthetic rate (the main [CO2] response); increasing length of growing season (the main temperature response); and higher leaf-area index (the main N deposition and partly [CO2] response). Soil organic matter will increase with increasing litter input, although priming may decrease the soil C stock initially, but litter quality effects should be minimal (response to [CO2], N deposition, and temperature); will decrease because of increasing temperature; and will increase because of retardation of decomposition with N deposition, although the rate of decomposition of high-quality litter can be increased and that of low-quality litter decreased. Single-factor responses can be misleading because of interactions between factors, in particular those between N and other factors, and indirect effects such as increased N availability from temperature-induced decomposition. In the long term the strength of feedbacks, for example the increasing demand for N from increased growth, will dominate over short-term responses to single factors. However, management has considerable potential for controlling the C store.     

The structure of the regulatory domain of the adenylyl cyclase Rv1264 from Mycobacterium tuberculosis with bound oleic acid

The universal secondary messenger cAMP is produced by adenylyl cyclases (ACs). Most bacterial and all eukaryotic ACs belong to class III of six divergent classes. A class III characteristic is formation of the catalytic pocket at a dimer interface and the presence of additional regulatory domains. Mycobacterium tuberculosis possesses 15 class III ACs, including Rv1264, which is activated at acidic pH due to pH-dependent structural transitions of the Rv1264 dimer. It has been shown by X-ray crystallography that the N-terminal regulatory and C-terminal catalytic domains of Rv1264 interact in completely different ways in the active and inhibited states. Here, we report an in-depth structural and functional analysis of the regulatory domain of Rv1264. The 1.6 A resolution crystal structure shows the protein in a tight, disk-shaped dimer, formed around a helical bundle, and involving a protein chain crossover. To understand pH regulation, we determined structures at acidic and basic pH values and employed structure-based mutagenesis in the holoenzyme to elucidate regulation using an AC activity assay. It has been shown that regulatory and catalytic domains must be linked in a single protein chain. The new studies demonstrate that the length of the linker segment is decisive for regulation. Several amino acids on the surface of the regulatory domain, when exchanged, altered the pH-dependence of AC activity. However, these residues are not conserved amongst a number of related ACs. The closely related mycobacterial Rv2212, but not Rv1264, is strongly activated by the addition of fatty acids. The structure resolved the presence of a deeply embedded fatty acid, characterised as oleic acid by mass spectrometry, which may serve as a hinge. From these data, we conclude that the regulatory domain is a structural scaffold used for distinct regulatory purposes.     

Cleavage of recombinant proteins at poly-His sequences by Co(II) and Cu(II)

Improved ways to cleave peptide chains at engineered sites easily and specifically would form useful tools for biochemical research. Uses of such methods include the activation or inactivation of enzymes or the removal of tags for enhancement of recombinant protein expression or tags used for purification of recombinant proteins. In this work we show by gel electrophoresis and mass spectroscopy that salts of Co(II) and Cu(II) can be used to cleave fusion proteins specifically at sites where sequences of His residues have been introduced by protein engineering. The His residues could be either consecutive or spaced with other amino acids in between. The cleavage reaction required the presence of low concentrations of ascorbate and in the case of Cu(II) also hydrogen peroxide. The amount of metal ions required for cleavage was very low; in the case of Cu(II) only one to two molar equivalents of Cu(II) to protein was required. In the case of Co(II), 10 molar equivalents gave optimal cleavage. The reaction occurred within minutes, at a wide pH range, and efficiently at temperatures ranging from 0 degrees C to 70 degrees C. The work described here can also have implications for understanding protein stability in vitro and in vivo.     

Post-mating disparity between potential and realized immune response in Drosophila melanogaster

Reproductive costs are an essential component of evolutionary theory. For instance, an increase in reproduction is generally coupled with a decrease in immunocompetence shortly after mating. However, recent work in Drosophila melanogaster suggests that the potential to mount an immune response, as measured by the levels of immune gene expression, increases after mating. These data are in contrast to previous studies, which suggest that mating can reduce a fly's ability to survive an actual bacterial challenge (realized immunity). This pattern may be driven by some aspect of mating, independent of resource limitation, which reduces immune function by inhibiting the effective deployment of immune gene products. Though several studies have examined both the potential and the realized immunity after mating, none have examined these immune measures simultaneously. Here, we examined the link between the potential and the realized immunity in a sterile mutant of D. melanogaster. Shortly after mating, we found that female immune gene expression was high, but survival against infection was low. Surprisingly, this pattern was reversed within 24 h. Thus, estimates of immunity based on gene expression do not appear to reflect an actual ability to defend against pathogens in the hours following copulation. We discuss the possible mechanisms that may account for this pattern.     

Computational modeling of factors that modulate the unique FeNO bonding in {FeNO}6 heme–thiolate model complexes

A density functional theory account of the changes in FeNO bonding that occur in response to both bonded and nonbonded structural perturbations is reported for a series of {FeNO}(6) heme-thiolate model complexes. Using [Fe(porphine)(SCH(3))NO] as the reference complex, we constructed models to mimic equatorial (cis), distal, and proximal influences of protein environments. Overall, the results from these calculations reveal that the Fe-NO and N-O bond strengths change in the same direction upon variations in structure and environment. These bonding changes are manifested in unique direct correlations between the Fe-NO and N-O vibrational frequencies and bond lengths, as evidenced by their positive slopes (slopes of the familiar inverse or backbonding correlations are negative). The electronic origin of the direct correlations appears to derive from the electron density distribution in high-energy molecular orbitals. This variability modulates the FeNO antibonding character throughout the triatomic FeNO moiety. The results of this study suggest that the stabilities and reactivities of {FeNO}(6) centers in heme-thiolate enzymes can be modulated over a significant range through a variety of bonded and nonbonded means.     

Proteomic analysis of high-grade dysplastic cervical cells obtained from ThinPrep slides using laser capture microdissection and mass spectrometry

The purpose of this discovery phase study was to identify candidate protein biomarkers for high-grade dysplastic cervical cells using mass spectrometry. Laser Capture Microdissection (LCM) was utilized to isolate high-grade dysplastic and normal cells from ThinPrep slides prepared from cervical cytological specimens. Following cell capture, samples were solubilized and proteins separated by gel electrophoresis in preparation for enzymatic digestion and liquid chromatography mass spectrometry analysis (LC-MS). Processed samples were subsequently analyzed using a linear ion trap coupled with a Fourier transform mass spectrometer (LTQ-FT MS). It was determined that both PreservCyt Solution and ThinPrep Pap Stain (Cytyc Corporation) were compatible with the sample processing and LC-MS analysis. In total, from 9 normal and 9 abnormal cervical cytological specimens, more than 1000 unique proteins were identified with high confidence, based on approximately 12,000 captured cells per specimen. Quantitative protein differences between HSIL (High-Grade Squamous Intraepithelial Lesion) and NILM (Negative for Intraepithelial Lesions or Malignancy) samples were determined by comparing the intensities of the representative (label-free) peptide ions. More than 200 proteins were found to exhibit a 3-fold difference in protein level. Interestingly, significant up-regulation of nuclear and mitochondrial proteins in HSIL specimens was noted. In several cases, the increased protein abundance observed in high-grade cells, as determined by quantitative LC-MS, was validated by immunocytochemical methods using ThinPrep cervical specimens. With the study of additional clinical specimens, the differential abundance of proteins in high-grade dysplastic cells versus morphologically normal cervical cells may lead to validated novel biomarkers for cervical disease.     

Relationship of aerobic and anaerobic parameters with 400 m front crawl swimming performance

The aims of the present study were to investigate the relationship of aerobic and anaerobic parameters with 400 m performance, and establish which variable better explains long distance performance in swimming. Twenty-two swimmers (19.1±1.5 years, height 173.9±10.0 cm, body mass 71.2±10.2 kg; 76.6±5.3% of 400 m world record) underwent a lactate minimum test to determine lactate minimum speed (LMS) (i.e., aerobic capacity index). Moreover, the swimmers performed a 400 m maximal effort to determine mean speed (S400m), peak oxygen uptake (V.O2PEAK) and total anaerobic contribution (C_ANA). The C_ANA was assumed as the sum of alactic and lactic contributions. Physiological parameters of 400 m were determined using the backward extrapolation technique (V.O2PEAK and alactic contributions of C_ANA) and blood lactate concentration analysis (lactic anaerobic contributions of C_ANA). The Pearson correlation test and backward multiple regression analysis were used to verify the possible correlations between the physiological indices (predictor factors) and S400m (independent variable) (p < 0.05). Values are presented as mean ± standard deviation. Significant correlations were observed between S400m (1.4±0.1 m·s^-1) and LMS (1.3±0.1 m·s^-1; r = 0.80), V.O2PEAK (4.5±3.9 L·min^-1; r = 0.72) and C_ANA (4.7±1.5 L·O₂; r= 0.44). The best model constructed using multiple regression analysis demonstrated that LMS and V.O2PEAK explained 85% of the 400 m performance variance. When backward multiple regression analysis was performed, C_ANA lost significance. Thus, the results demonstrated that both aerobic parameters (capacity and power) can be used to predict 400 m swimming performance.     

Serum metalloproteinase-9 is related to COPD severity and symptoms - cross-sectional data from a population based cohort-study

Background

Chronic obstructive pulmonary disease, COPD, is an increasing cause of morbidity and mortality worldwide, and an imbalance between proteases and antiproteases has been implicated to play a role in COPD pathogenesis. Matrix metalloproteinases (MMP) are important proteases that along with their inhibitors, tissue inhibitors of metalloproteinases (TIMP), affect homeostasis of elastin and collagen, of importance for the structural integrity of human airways. Small observational studies indicate that these biomarkers are involved in the pathogenesis of COPD. The aim of this study was to investigate serum levels of MMP-9 and TIMP-1 in a large Swedish population-based cohort, and their association with disease severity and important clinical symptoms of COPD such as productive cough.

Methods

Spirometry was performed and peripheral blood samples were collected in a populations-based cohort (median age 67 years) comprising subjects with COPD (n = 594) and without COPD (n = 948), in total 1542 individuals. Serum MMP-9 and TIMP-1 concentrations were measured with enzyme linked immunosorbant assay (ELISA) and related to lung function data and symptoms.

Results

Median serum MMP-9 values were significantly higher in COPD compared with non-COPD 535 vs. 505 ng/ml (P = 0.017), without any significant differences in serum TIMP-1-levels or MMP-9/TIMP-1-ratio. In univariate analysis, productive cough and decreasing FEV₁% predicted correlated significantly with increased MMP-9 among subjects with COPD (P = 0.004 and P = 0.001 respectively), and FEV₁% predicted remained significantly associated to MMP-9 in a multivariate model adjusting for age, sex, pack years and productive cough (P = 0.033).

Conclusion

Productive cough and decreasing FEV₁ were each associated with MMP-9 in COPD, and decreasing FEV₁ remained significantly associated with MMP-9 also after adjustment for common confounders in this population-based COPD cohort. The increased serum MMP-9 concentrations in COPD indicate an enhanced proteolytic activity that is related to disease severity, and further longitudinal studies are important for the understanding of MMP-9 in relation to the disease process and the pathogenesis of different COPD phenotypes.