The role of intravascular ultrasound imaging in vascular brachytherapy

Intracoronary brachytherapy has recently emerged as a new therapy to prevent restenosis. Initial experimental work was achieved in animal models and the results were assessed by histomorphometry. Initial clinical trials used angiography to guide dosimetry and to assess efficacy. Intravascular ultrasound (IVUS) permits tomographic examination of the vessel wall, elucidating the true morphology of the lumen and transmural components, which cannot be investigated on the lumenogram obtained by angiography. This paper reviews the use of IVUS in the clinical studies of brachytherapy conducted to date. IVUS allows clinicians to make a thorough assessment of the remodeling of the vessel and appears to have a major role to play in facilitating understanding of the underlying mechanisms of action in this emerging field. The authors propose that state-of-the-art IVUS techniques should be employed to further knowledge of the mechanisms of action of brachytherapy in atherosclerotic human coronary arteries.     

Improving model construction of profile HMMs for remote homology detection through structural alignment

Background  

Remote homology detection is a challenging problem in Bioinformatics. Arguably, profile Hidden Markov Models (pHMMs) are one of the most successful approaches in addressing this important problem. pHMM packages present a relatively small computational cost, and perform particularly well at recognizing remote homologies. This raises the question of whether structural alignments could impact the performance of pHMMs trained from proteins in the Twilight Zone, as structural alignments are often more accurate than sequence alignments at identifying motifs and functional residues. Next, we assess the impact of using structural alignments in pHMM performance.     

SNP-SNP Interactions Discovered by Logic Regression Explain Crohn's Disease Genetics

In genome-wide association studies (GWAS), the association between each single nucleotide polymorphism (SNP) and a phenotype is assessed statistically. To further explore genetic associations in GWAS, we considered two specific forms of biologically plausible SNP-SNP interactions, ‘SNP intersection’ and ‘SNP union,’ and analyzed the Crohn''s Disease (CD) GWAS data of the Wellcome Trust Case Control Consortium for these interactions using a limited form of logic regression. We found strong evidence of CD-association for 195 genes, identifying novel susceptibility genes (e.g., ISX, SLCO6A1, TMEM183A) as well as confirming many previously identified susceptibility genes in CD GWAS (e.g., IL23R, NOD2, CYLD, NKX2-3, IL12RB2, ATG16L1). Notably, 37 of the 59 chromosomal locations indicated for CD-association by a meta-analysis of CD GWAS, involving over 22,000 cases and 29,000 controls, were represented in the 195 genes, as well as some chromosomal locations previously indicated only in linkage studies, but not in GWAS. We repeated the analysis with two smaller GWASs from the Database of Genotype and Phenotype (dbGaP): in spite of differences of populations and study power across the three datasets, we observed some consistencies across the three datasets. Notable examples included TMEM183A and SLCO6A1 which exhibited strong evidence consistently in our WTCCC and both of the dbGaP SNP-SNP interaction analyses. Examining these specific forms of SNP interactions could identify additional genetic associations from GWAS. R codes, data examples, and a ReadMe file are available for download from our website: http://www.ualberta.ca/~yyasui/homepage.html.     

Perioperative oxygen fraction – effect on surgical site infection and pulmonary complications after abdominal surgery: a randomized clinical trial. Rationale and design of the PROXI-Trial

Background

Infants born at extreme prematurity (below 28 weeks' gestation) are at high risk of developmental disability. A major risk factor for disability is having a low level of thyroid hormone which is recognised to be a frequent phenomenon in these infants. At present it is unclear whether low levels of thyroid hormone are a cause of disability, or a consequence of concurrent adversity.

Methods

We propose an explanatory multi-centre double blind randomised controlled trial of thyroid hormone supplementation in babies born below 28 weeks' gestation. All infants will receive either levothyroxine or placebo until 32 weeks' corrected gestational age. The primary outcome will be brain growth. This will be assessed by the width of the sub-arachnoid space measured using cranial ultrasound and head circumference at 36 weeks' corrected gestational. The secondary outcomes will be (a) thyroid hormone concentrations measured at increasing postnatal age, (b) status of the hypothalamic pituitary axis, (c) auxological data between birth and 36 weeks' corrected gestational age, (d) thyroid gland volume, (e) volumes of brain structures (measured by magnetic resonance imaging), (f) determination of the extent of myelination and white matter integrity (measured by diffusion weighted MRI) and brain vessel morphology (measured by magnetic resonance angiography) at expected date of delivery and (g) markers of morbidity including duration of mechanical ventilation and chronic lung disease. We will also examine how activity of the hypothalamic-pituitary-adrenal axis modulates the effects of thyroid supplementation. This will contribute to decisions about which confounding variables to assess in large-scale studies.

Trial registration

Current Controlled Trials ISRCTN89493983     

Rhythmic cyclic AMP changes in Chlamydomonas cells synchronized by temperature and light cycles in chemostat culture

Division in chemostat cultures of Chlamydomonas reinhardi was synchronized by daily cycles of both temperature and light. In response to 8 h cool (20 degrees C) - dim light/16 h warm (28 degrees C) - bright light cycles and continuous dilution that removed half the cells daily, the cells replicated nuclear DNA late in the warm-bright phase; released an average of two daughter zoospores early in the warm-bright phase of the next cycle. In these synchronized green algal cultures all ATP and most cAMP were intracellular; most cGMP (approximately 91%) was extracellular. Early in the warm-bright phase ATP doubled after which cAMP level fell 25%. During DNA replication cAMP level doubled, rising to a modest peak reached as replication ended.     

The characterization of aluminium — alanine complex

The potentiometric titration curves and computer modelling studies indicated that aluminium complexes with alanine at-C00^– moiety and also altered the proton affinity at⁺NH₃ and-CH₃ moiety.²⁷Al NMR spectra broadening also confirmed the interaction.     

Evaluation of the alleviative role of Chlorella vulgaris and Spirulina platensis extract against ovarian dysfunctions induced by monosodium glutamate in mice

Microalgae provide a wealthy natural resource of bioactive compounds, which have many biological activities. Monosodium glutamate is a food additive that acts either as food preservatives or as tastiness enhancer. It was confirmed that monosodium glutamate poses a serious responsibility in the pathogenesis of anovulatory infertility. Therefore, the idea of this research was directed to reveal efficiency of Chlorella vulgaris and Spirulina platensis extracts against the ovarian dysfunction resulted due to monosodium glutamate consumption. Adult female albino mice were gavages orally monosodium glutamate alone or with either Chlorella vulgaris or Spirulina platensis aqueous extracts for 28?days. Female mice were subjected to superovulation to study the oocytes nuclear maturation stages. Histological and quantitative investigation was carried on ovaries. Biochemical assessment to measure the sex hormones level and ovarian enzymatic antioxidants was done. In addition, ovarian antioxidant mRNA genes were determined using quantitative PCR and Glyceraldehyde-3-phosphate dehydrogenase was used as an internal control. The result revealed that monosodium glutamate reduced the oocytes quality and maturation rate, while, both algae improve the oocyte quality and maturation rate than in monosodium glutamate group. Chlorella vulgaris and Spirulina platensis improved the monosodium glutamate ovarian tissue histological alteration, sex hormones content and raised the ovarian enzymatic antioxidants level. In addition, monosodium glutamate markedly diminished the Glutathione peroxidase, superoxide dismutase and catalase mRNA expressions, However, Chlorella vulgaris or Spirulina platensis upregulated the expression of genes close to control. In conclusion, Chlorella vulgaris and Spirulina platensis showed potential alleviative role against the monosodium glutamate ovarian dysfunction.