IDGH-CURRENT DIRECT INJECTION TO A CW RFQ USING AN ECR PROTON SOURCE"

Abstract The results of a direct injection experiment on the cw RFQl-1250 proton accelerator are reported. The experiment was made possible by a high-current low-emittance electron cyclotron resonance ion source, with a 70 to 90 % proton fraction and a gas efficiency of up to 60 %. A beam transport system, consisting only of drift spaces and a solenoid lens, matched the beam to the radiofrequency quadrupole. A relatively high pressure in the low energy beam transport system ensured a high degree of neutralization to counteract space charge forces

The development of a 16S rRNA gene based PCR for the identification of Streptococcus pneumoniae and comparison with four other species specific PCR assays

<p>Abstract</p> <p>Background</p> <p><it>Streptococcus pneumoniae </it>is one of the most frequently encountered pathogens in humans but its differentiation from closely related but less pathogenic streptococci remains a challenge.</p> <p>Methods</p> <p>This report describes a newly-developed PCR assay (Spne-PCR), amplifying a 217 bp product of the 16S rRNA gene of <it>S. pneumoniae</it>, and its performance compared to other genotypic and phenotypic tests.</p> <p>Results</p> <p>The new PCR assay designed in this study, proved to be specific at 57°C for <it>S. pneumoniae</it>, not amplifying <it>S. pseudopneumoniae </it>or any other streptococcal strain or any strains from other upper airway pathogenic species. PCR assays (psaA, LytA, ply, spn9802-PCR) were previously described for the specific amplification of <it>S. pneumoniae</it>, but <it>psaA</it>-PCR was the only one found not to cross-react with <it>S. pseudopneumoniae</it>.</p> <p>Conclusion</p> <p>Spne-PCR, developed for this study, and psaA-PCR were the only two assays which did not mis-identify <it>S. pseudopneumoniae </it>as <it>S. pneumoniae</it>. Four other PCR assays and the AccuProbe assay were unable to distinguish between these species.</p

Identification of Streptococcus pneumoniae by a real-time PCR assay targeting SP2020.

Real-time PCR targeting lytA (the major autolysin gene) and piaB (permease gene of the pia ABC transporter) are currently used as the gold-standard culture-independent assays for Streptococcus pneumoniae identification. We evaluated the performance of a new real-time PCR assay - targeting SP2020 (putative transcriptional regulator gene) - and compared its performance with the assays previously described. A collection of 150 pneumococci, 433 non-pneumococci and 240 polymicrobial samples (obtained from nasopharynx, oropharynx, and saliva; 80 from each site) was tested. SP2020 and lytA-CDC assays had the best performance (sensitivity of 100% for each compared to 95.3% for piaB). The specificity for lytA and piaB was 99.5% and for SP2020 was 99.8%. Misidentifications occurred for the three genes: lytA, piaB and SP2020 were found in non-pneumococcal strains; piaB was absent in some pneumococci including a serotype 6B strain. Combining lytA and SP2020 assays resulted in no misidentifications. Most polymicrobial samples (88.8%) yielded concordant results for the three molecular targets. The remaining samples seemed to contain non-typeable pneumococci (0.8%), and non-pneumococci positive for lytA (1.7%) or SP2020 (8.7%). We propose that combined detection of both lytA-CDC and SP2020 is a powerful strategy for the identification of pneumococcus either in pure cultures or in polymicrobial samples

Reversible Sympathetic Overactivity in Hypertensive Patients with Primary Aldosteronism

Context: Aldosterone has been shown to exert a central sympathoexcitatory action in multiple animal models, but evidence in humans is still lacking

Efficacy of a Swab Transport System in Maintaining Viability of Neisseria gonorrhoeae and Streptococcus pneumoniae

The efficacy of swab transport systems in maintaining viability of Neisseria gonorrhoeae and Streptococcus pneumoniae is crucial both for establishing definitive diagnosis and for monitoring emerging resistance. We tested the efficacy of a newly modified Amies charcoal swab transport system, the StarSwab SP131X (Starplex Scientific, Inc., Etobicoke, Ontario, Canada), by using a combined total of 31 clinical and American Type Culture Collection stock reference strains of N. gonorrhoeae and S. pneumoniae in 46 suspensions of concentrations ranging from 10(5) to 10(8) CFU/ml. Triplicate swabs per strain held at room temperature for 0, 24, and 48 h were plated without prior vortexing, and their growths were graded. All 31 strains were viable at 0 and 24 h. Gonococcal viability at 48 h varied considerably, even among strains with comparable inoculum sizes, suggesting that viability might be strain dependent and confirming the different structural and growth profiles of gonococcal strains. S. pneumoniae strains showed consistent viability, with all strains recovered at all holding periods. This study demonstrates that the StarSwab SP131X is capable of maintaining the viability of N. gonorrhoeae and S. pneumoniae for at least 24 and 48 h, respectively, and reinforces the need for adequate sampling and for timely processing of specimens to maintain optimum performance

Functional sympatholysis is impaired in hypertensive humans

In healthy individuals, sympathetic vasoconstriction is markedly blunted in exercising muscles to optimize blood flow to the metabolically active muscle fibres. This protective mechanism, termed functional sympatholysis, is impaired in rat models of angiotensin-dependent hypertension. However, the relevance of these findings to human hypertension is unknown. Therefore, in 13 hypertensive and 17 normotensive subjects we measured muscle oxygenation and forearm blood flow (FBF) responses to reflex increases in sympathetic nerve activity (SNA) evoked by lower body negative pressure (LBNP) at rest and during moderate-intensity rhythmic handgrip exercise. In the normotensives, LBNP caused decreases in oxygenation and FBF (−16 ± 2% and −23 ± 4%, respectively) in resting forearm but not in exercising forearm (−1 ± 2% and −1 ± 3%, respectively; P < 0.05 vs. rest). In the hypertensives, LBNP evoked decreases in oxygenation and FBF that were similar in the resting and exercising forearm (−14 ± 2%vs.−12 ± 2% and −20 ± 3%vs.−13 ± 2%, respectively; P > 0.05), indicating impaired functional sympatholysis. In the hypertensives, SNA was unexpectedly increased by 54 ± 11% during handgrip alone. However, when SNA was experimentally increased during exercise in the normotensives, sympatholysis was unaffected. Treatment for 4 weeks with the angiotensin receptor blocker irbesartan, but not with the thiazide-type diuretic chlorthalidone, restored sympatholysis in the hypertensives. These data provide the first evidence that functional sympatholysis is impaired in hypertensive humans by a mechanism that appears to involve an angiotensin-dependent increase in sympathetic vasoconstriction in the exercising muscles