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Selected AbstractsMulticontrast black-blood MRI of carotid arteries: Comparison between 1.5 and 3 tesla magnetic field strengthsJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 5 2006Vasily L. Yarnykh PhD Abstract Purpose To compare black-blood multicontrast carotid imaging at 3T and 1.5T and assess compatibility between morphological measurements of carotid arteries at 1.5T and 3T. Materials and Methods Five healthy subjects and two atherosclerosis patients were scanned in 1.5T and 3T scanners with a similar protocol providing transverse T1 -, T2 -, and proton density (PD)-weighted black-blood images using a fast spin-echo sequence with single- (T1 -weighted) or multislice (PD-/T2 -weighted) double inversion recovery (DIR) preparation. Wall and lumen signal-to-noise ratio (SNR) and wall/lumen contrast-to-noise ratio (CNR) were compared in 44 artery cross-sections by paired t -test. Interscanner variability of the lumen area (LA), wall area (WA), and mean wall thickness (MWT) was assessed using Bland-Altman analysis. Results Wall SNR and lumen/wall CNR significantly increased (P < 0.0001) at 3T with a 1.5-fold gain for T1 -weighted images and a 1.7/1.8-fold gain for PD-/T2 -weighted images. Lumen SNR did not differ for single-slice DIR T1 -weighted images (P = 0.2), but was larger at 3T for multislice DIR PD-/T2 -weighted images (P = 0.01/0.03). The LA, WA, and MWT demonstrated good agreement with no significant bias (P 0.5), a coefficient of variation (CV) of <10%, and intraclass correlation coefficient (ICC) of >0.95. Conclusion This study demonstrated significant improvement in SNR, CNR, and image quality for high- resolution black-blood imaging of carotid arteries at 3T. Morphologic measurements are compatible between 1.5T and 3T. J. Magn. Reson. Imaging 2006. © 2006 Wiley-Liss, Inc. [source] Encapsulation of a Single Metal Nanoparticle with Tunable Size in a Monodisperse Polymer MicrocapsuleMACROMOLECULAR RAPID COMMUNICATIONS, Issue 3 2009Haiqing Li Abstract A versatile approach to fabricate monodisperse poly[styrene- co -(divinyl benzene)] (PS- co -DVB) microcapsules that contain a single gold nanoparticle (AuNP) has been demonstrated. Using the PS- co -DVB microcapsule as a microreactor, aqueous HAuCl4 and NaBH4 solutions are subsequently infiltrated. The size of the resulting AuNP inside of the PS- co -DVB microcapsules is easily tunable by controlling the repeated infiltration cycles of aqueous HAuCl4 and NaBH4. PS- co -DVB microcapsules that contain a single silver and palladium nanoparticle are also obtained by following a similar protocol. [source] Influence of sexual stimulation on sperm parameters in semen samples collected via masturbation from normozoospermic men or cryptozoospermic men participating in an assisted reproduction programmeANDROLOGIA, Issue 3 2000Y. Yamamoto Summary. To evaluate the influence of sexual stimulation via sexually stimulating videotaped visual images (VIM) on sperm function, two semen samples were collected from each of 19 normozoospermic men via masturbation with VIM. Two additional samples were collected from each man via masturbation without VIM. The volume of seminal plasma, total sperm count, sperm motility, percentage of morphologically normal spermatozoa, outcome of hypo-osmotic swelling test and zona-free hamster oocyte sperm penetration assay, and markers of the secretory function of prostate were significantly larger in semen samples collected via masturbation with VIM than masturbation without VIM. The improved sperm parameters in the samples collected via masturbation with VIM may reflect an enhanced prostatic secretory function and increased loading of the vas deferens at that time. In a similar protocol, two semen samples were collected via masturbation with VIM from each of 22 non-obstructed azoospermic men. Semen samples from these men had been occasionally positive in the past for a very small number of spermatozoa (cryptozoospermic men). Two additional samples were collected from each cryptozoospermic man via masturbation without VIM. The volume of seminal plasma, total sperm count, sperm motility, and a marker of the secretory function of prostate were significantly larger in semen samples collected via masturbation with VIM. Fourteen out of the 22 men were negative for spermatozoa in both samples collected via masturbation without VIM. These men demonstrated spermatozoa in both samples collected via masturbation with VIM. Six men with immotile spermatozoa in both samples collected via masturbation without VIM exposed motile spermatozoa in both samples collected via masturbation with VIM. High sexual stimulation during masturbation with VIM results in recovery of spermatozoa of greater fertilizing potential both in normozoospermic and cryptozoospermic men. The appearance of spermatozoa after masturbation with VIM in the vast majority of cryptozoospermic men is of clinical significance in programmes applying intracytoplasmic sperm injections for the management of severe male infertility and obviates the need for testicular biopsy. [source] The short-term effects of air pollution on daily mortality in four Australian citiesAUSTRALIAN AND NEW ZEALAND JOURNAL OF PUBLIC HEALTH, Issue 3 2005Rod Simpson Objective: To examine the short-term health effects of air pollution on daily mortality in four Australian cities (Brisbane, Melbourne, Perth and Sydney), where more than 50% of Australians reside. Methods: The study used a similar protocol to APHEA2 (Air Pollution and Health: A European Approach) study and derived single-city and pooled estimates. Results: The results derived from the different approaches for the 1996-99 period showed consistent results for different statistical models used. There were significant effects on total mortality, (RR=1.0284 per 1 unit increase in nephelometry [10 -4. m -1], RR=1.0011 per 1ppb increase in NO2), and on respiratory mortality (RR=1.0022 per 1ppb increase in O3). No significant differences between cities were found, but the NO2 and particle effects may refer to the same impacts. Meta-analyses carried out for three cities yielded estimates for the increase in the daily total number of deaths of 0.2% (-0.8% to 1.2%) for a 10 ,g/m3 increase in PM10 concentration, and 0.9% (-0.7% to 2.5%) for a 10 ,g/m3 increase in PM2.5 concentration. Conclusions: Air pollutants in Australian cities have significant effects on mortality. [source] Local lung responses following local lung challenge with recombinant lungworm antigen in systemically sensitized sheepCLINICAL & EXPERIMENTAL ALLERGY, Issue 10 2001D. D. S. Collie Background Chronic mast cell-mediated inflammation may contribute significantly towards the extensive tissue remodelling that is a feature of lungworm infection in ruminants. Understanding the factors that control tissue remodelling is a necessary step toward effective management and treatment of conditions that feature such pathology. Objective We sought to define in a novel ovine model system, the cellular, immune and mast cell phenotypic events that occur following local lung challenge with a recombinant protein antigen, DvA-1, derived from the ruminant lungworm nematode, Dictyocaulus viviparus. Methods Two spatially disparate lung segments in systemically sensitized sheep were challenged on three occasions with DvA-1 (3xDVA) and two further segments were challenged with saline (3xSAL). Two months after the third challenge, one of the two segments previously repeatedly challenged with DvA-1 was challenged again with DvA-1 (3xDVA:DVA) whilst the other was challenged with saline (3xDVA:SAL). A similar protocol was followed with the saline challenged segments (3xSAL:SAL and 3xSAL:DVA). Bronchoalveolar lavage fluid (BALF) (n = 16) and tissue (n = 3) were collected after the last challenge. Results Cellular changes 24 h after the fourth challenge were characterized by an increase in the absolute numbers of neutrophils and eosinophils in BALF from 3xDVA:DVA and 3xSAL:DVA segments. Local antibody production was implied through increased levels of antibody in both 3xDVA:DVA and 3xDVA:SAL segments, with the latter being unaffected by inflammation. Levels of active transforming growth factor beta-1 (TGF-,1) were significantly increased in 3xDVA:SAL segments and a trend towards an increase was apparent in 3xDVA:DVA segments. Total TGF-,1 levels were significantly correlated with eosinophil counts in all except the 3xDVA:SAL segments. Such changes in the bronchoalveolar space were complemented by increased ratios of sheep mast cell proteinase-1 expressing cells and tryptase expressing cells, to toluidine blue positive cells in airways from 3xDVA:DVA segments. Conclusion Mast cell phenotypic events occurring as a consequence of antigen challenge were limited to segments in which changes in BALF were characterized by neutrophil influx and increased local antibody production. [source] Radiation technique influence on percutaneous endoscopic gastrostomy tube dependence: Comparison between two radiation schemesHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 7 2009Georges F. Hatoum MD Abstract Background. Our aim was to determine whether percutaneous endoscopic gastrostomy (PEG) dependence was significantly different between 2 prospective trials with different radiation fractionation schemes. Methods. Stage III or IV locally advanced head and neck squamous cell carcinomas arising from the oral cavity, hypopharynx, oropharynx, nasopharynx, paranasal sinuses, or larynx were treated using hyperfractionation (A-3 protocol) or accelerated fractionation (A-4 protocol) with chemotherapy. Amifostine was administered 15 to 30 minutes preradiation, at a dose of 500 mg/day in both protocols. It was given as an infusion over 5 to 7 minutes (A-3 protocol) or subcutaneously (A-4 protocol). Data regarding PEG placement and removal were collected prospectively. Results. Thirty-five evaluable A-3 protocol patients, 14 evaluable A-4 protocol patients, and 6 patients treated per A-4 protocol guidelines, but without amifostine as they refused the medication, were included in the analysis. Pretreatment characteristics, such as sex, age, race, T classification, N classification, American Joint Committee on Cancer (AJCC) stage, were compared between the 2 groups of patients. The only significant difference between the 2 groups was AJCC stage. Thirty-five A-3 patients and 20 A-4 patients had overall survivals of 88% versus 80%, 82% versus 75%, and 66% versus 67.5% at 1, 2, and 3 years, respectively (p = .958). With regard to PEG dependence, no significant differences were seen between the 2 groups at 6, 12, or 18 months. Conclusion. PEG dependence was not significantly different between the 2 study groups. Type of altered fractionation scheme may not influence PEG dependence in patients treated with similar protocols. Future randomized studies are needed to confirm these findings. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source] ISOLATION AND CHARACTERIZATION OF A CELL WALL-DEFECTIVE MUTANT OF CHLAMYDOMONAS MONOICA (CHLOROPHYTA),JOURNAL OF PHYCOLOGY, Issue 6 2003Cesar Fuentes Cell wall,defective strains of Chlamydomonas have played an important role in the development of transformation protocols for introducing exogenous DNA (foreign genes or cloned Chlamydomonas genes) into C. reinhardtii. To promote the development of similar protocols for transformation of the distantly related homothallic species, C. monoica, we used UV mutagenesis to obtain a mutant strain with a defective cell wall. The mutant, cw-1, was first identified on the basis of irregular colony shape and was subsequently shown to have reduced plating efficiency and increased sensitivity to lysis by a non-ionic detergent as compared with wild-type cells. Tetrad analysis of crosses involving the cw-1 mutant confirmed 2:2 segregation of the cw:cw+ phenotypes, indicating that the wall defect resulted from mutation of a single nuclear gene. The phenotype showed incomplete penetrance and variable expressivity. Although some cells had apparently normal cell walls as viewed by TEM, many cells of the cw-1 strain had broken cell walls and others were protoplasts completely devoid of a cell wall. Several cw-1 isolates obtained from crosses involving the original mutant strain showed a marked enhancement of the mutant phenotype and may prove especially useful for future work involving somatic cell fusions or development of transformation protocols. [source] High-level cell-free synthesis yields of proteins containing site-specific non-natural amino acidsBIOTECHNOLOGY & BIOENGINEERING, Issue 2 2009Aaron R. Goerke Abstract We describe an E. coli -based cell-free system for the production of proteins with a non-natural amino acid (nnAA) incorporated site-specifically (modified protein). The mutant Methanococcus jannaschii tyrosyl-tRNA synthetase (mTyrRS) and tRNATyr pair were used as orthogonal elements. The mTyrRS experienced proteolysis and modified protein yields improved with higher synthetase addition (200,300 µg/mL). Product yields were also improved by increasing levels of total protein to 20 mg protein/mL and available vesicle surface area to 0.5 m2/mL. This new E. coli -based cell-free procedure produced up to 400 µg/mL of eCAT109pAz, 660 µg/mL of eDHFR10pAz, and 210 µg/mL of mDHFR31pAz with p -azido- L -phenylalanine (pAz) incorporated site-specifically at the amber nonsense codon. O -methyl- L -tyrosine and p -acetyl- L -phenylalanine were incorporated by similar protocols. The desired specificity for incorporation of the nnAA by the cell-free system was confirmed. Additionally, the modified proteins were enzymatically active and reactive for copper(I)-catalyzed (3,+,2) cycloadditions (click chemistry). Biotechnol. Bioeng. 2009;102: 400,416. © 2008 Wiley Periodicals, Inc. [source] | |||||||||||||