Transcription in yeast: separation and properties of multiple FNA polymerases

Four peaks of DNA-directed RNA polymerase activity are resolved by salt gradient elution of a sonicated yeast cell extract on DEAE-Sephadex. The enzymes, which are named IA, IB, II, and III in order of elution, all appear to come from cell nuclei. Only enzyme II is sensitive to alpha-amanitin. All enzymes are more active with Mn(++) than with Mg(++) as divalent ion. Enzymes IB and II have salt optima in the range 0.05-0.10 M (NH(4))(2)SO(4), whereas enzyme III is maximally active at 0.20-0.25 M (NH(4))(2)SO(4). With optimal salt concentration and saturating DNA, the template preference ratio, activity on native calfthymus DNA divided by activity on denatured calf-thymus DNA, is 2.2 for IB, 0.4 for II, and 3.5 for III. None of the yeast polymerases was inhibited by rifamycin SV. Rifamycin AF/013 effectively inhibited polymerases IB, II, and III.     

Neural evidence for an association between social proficiency and sensitivity to social reward

Data from developmental psychology suggests a link between the growth of socio-emotional competences and the infant''s sensitivity to the salience of social stimuli. The aim of the present study was to find evidence for this relationship in healthy adults. Thirty-five participants were recruited based on their score above the 85th or below the 15th percentile of the empathy quotient questionnaire (EQ, Baron-Cohen and Wheelwright, 2004). Functional magnetic resonance imaging (fMRI) was used to compare neural responses to cues of social and non-social (monetary) reward. When compared to the high-EQ group, the low-EQ group showed reduced activity of the brain s reward system, specifically the right nucleus accumbens, in response to cues predictive of social reward (videos showing gestures of approval)—but increased activation in this area for monetary incentives. Our data provide evidence for a link between self-reported deficits in social proficiency and reduced sensitivity to the motivational salience of positive social stimuli.     

Cardiac Platypnea‐Orthodeoxia Syndrome: An Often Unrecognized Malady

Platypnea‐orthodeoxia syndrome (POS) is a rare but clinically important form of dyspnea. The syndrome is characterized by dyspnea and arterial oxygen desaturation that occurs in the upright position and improves with recumbency. In cardiac POS, an atrial septal defect or patent foramen ovale allows communication between the right‐ and left‐sided circulations. A second defect, such as a dilated aorta, prominent eustachian valve, or pneumonectomy, then contributes to right‐to‐left shunting through the interatrial connection. Diagnosis is made through pulse oximetry to confirm orthodeoxia and through transesophageal echocardiography with bubble study to visualize the shunt. Although data are limited for this rare syndrome, percutaneous closure has thus far proven safe and effective.     

Trajectories of the cortisol awakening responses during weight gain in anorexia nervosa patients with severe and less severe symptoms

The aim of this study was to examine the features and changes of the cortisol awakening response (CAR) in patients with anorexia nervosa (AN) with severe and less severe symptoms over the course of inpatient treatment.     

Evaluation of a novel strain of infectious bronchitis virus emerged as a result of spike gene recombination between two highly diverged parent strains

The emergence of new variant strains of the poultry pathogen infectious bronchitis virus (IBV) is continually reported worldwide, owing to the labile nature of the large single-stranded RNA IBV genome. High resolution melt curve analysis previously detected a variant strain, N1/08, and the present study confirmed that this strain had emerged as a result of recombination between Australian subgroup 2 and 3 strains in the spike gene region, in a similar manner reported for turkey coronaviruses. The S1 gene for N1/08 had highest nucleotide similarity with subgroup 2 strains, which is interesting considering subgroup 2 strains have not been detected since the early 1990s. SimPlot analysis of the 7.2-kb 3′ end of the N1/08 genome with the same region for other Australian reference strains identified the sites of recombination as immediately upstream and downstream of the S1 gene. A pathogenicity study in 2-week-old chickens found that N1/08 had similar pathogenicity for chicken respiratory tissues to that reported for subgroup 2 strains rather than subgroup 3 strains. The results of this study demonstrate that recombination is a mechanism utilized for the emergence of new strains of IBV, with the ability to alter strain pathogenicity in a single generation.