A search for biogenic trace gases in the atmosphere of Mars

The detection of certain trace gases in the atmosphere of Mars may serve as a possible indicator of microbial life on the surface of Mars. Candidate biogenic gases include methane CH4, ammonia NH3, nitrous oxide N2O, and several reduced sulfur species. Chemical thermodynamic equilibrium and photochemical calculations preclude the presence of these gases in any measurable concentrations in the atmosphere of Mars in the absence of biogenic production. A search for these gases utilizing either high resolution (spectral and spatial) spectroscopy from a Mars orbiter, such as the Observer, and or in situ measurements from a Mars lander or rover, is proposed

Overlapping resonances in the control of intramolecular vibrational redistribution

Coherent control of bound state processes via the interfering overlapping resonances scenario [Christopher et al., J. Chem. Phys. 123, 064313 (2006)] is developed to control intramolecular vibrational redistribution (IVR). The approach is applied to the flow of population between bonds in a model of chaotic OCS vibrational dynamics, showing the ability to significantly alter the extent and rate of IVR by varying quantum interference contributions.Comment: 10 pages, 7 figure

Phase II Trial of IL-12 Plasmid Transfection and PD-1 Blockade in Immunologically Quiescent Melanoma.

PurposeTumors with low frequencies of checkpoint positive tumor-infiltrating lymphocytes (cpTIL) have a low likelihood of response to PD-1 blockade. We conducted a prospective multicenter phase II trial of intratumoral plasmid IL-12 (tavokinogene telseplasmid; "tavo") electroporation combined with pembrolizumab in patients with advanced melanoma with low frequencies of checkpoint positive cytotoxic lymphocytes (cpCTL).Patients and methodsTavo was administered intratumorally days 1, 5, and 8 every 6 weeks while pembrolizumab (200 mg, i.v.) was administered every 3 weeks. The primary endpoint was objective response rate (ORR) by RECIST, secondary endpoints included duration of response, overall survival and progression-free survival. Toxicity was evaluated by the CTCAE v4. Extensive correlative analysis was done.ResultsThe combination of tavo and pembrolizumab was well tolerated with adverse events similar to those previously reported with pembrolizumab alone. Patients had a 41% ORR (n = 22, RECIST 1.1) with 36% complete responses. Correlative analysis showed that the combination enhanced immune infiltration and sustained the IL-12/IFNγ feed-forward cycle, driving intratumoral cross-presenting dendritic cell subsets with increased TILs, emerging T cell receptor clones and, ultimately, systemic cellular immune responses.ConclusionsThe combination of tavo and pembrolizumab was associated with a higher than expected response rate in this poorly immunogenic population. No new or unexpected toxicities were observed. Correlative analysis showed T cell infiltration with enhanced immunity paralleling the clinical activity in low cpCTL tumors

Rapid Assessment Tool for Haemophilus influenzae type b Disease in Developing Countries1

Haemophilus influenzae type b disease prevalence in children provides estimates of national disease prevalence

High resolution gas chromatographic analysis of cytochrome P-448 inducing polychlorinated biphenyl congeners in hazardous waste

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/25011/1/0000438.pd

Lowered-intensity preparative regimen for allogeneic stem cell transplantation delays acute graft-versus-host disease but does not improve outcome for advanced hematologic malignancy

AbstractReduced conditioning intensity has extended the option of allogeneic hematopoietic stem cell transplantation to patients who cannot tolerate fully myeloablative regimens. However, relapse and graft-versus-host disease (GVHD) continue to be major causes of morbidity and mortality. We prospectively tested whether a moderate reduction of the intensity of the preparative regimen would lead to significant reduction in regimen-related toxicity without compromising tumor control in a cohort of 44 patients ineligible for conventional hematopoietic stem cell transplantation. Patients were conditioned with fludarabine, busulfan, mycophenolate, and total lymphoid irradiation. Tacrolimus and methotrexate were given as prophylaxis for GVHD. Donors were 5 of 6 or 6 of 6 matched family members. The median age was 61 years. Eleven patients had comorbid conditions that precluded conventional myeloablative transplantation. Fatal regimen-related organ toxicity occurred in 3 patients. The cumulative incidence of grade 2 to 4 or grade 3 to 4 acute GVHD by day 100 was 38% (95% confidence interval [CI] = 25%, 55%) and 20% (95% CI = 10%, 39%), respectively, with a median time to onset of 66 days. For the entire cohort, 1-year overall survival, disease-free survival, and relapse rates were 54% (95% CI = 41%, 71%), 47% (95% CI = 35%, 65%), and 37% (95% CI = 19%, 51%), respectively. Outcomes differed based on stage of disease at time of transplantation, advanced (n = 19) versus nonadvanced (n = 25). Median survival times were 138 days and 685 days for subjects with advanced and nonadvanced disease, respectively (P = .005). After adjusting for age and comorbidity, disease stage continued to be significantly associated with overall survival (P = .005). In conclusion, a moderate reduction in conditioning dose intensity resulted in delayed onset of acute GVHD (compared with historical controls). A reduction in conditioning intensity is associated with poor survival for patients with advanced-stage disease, highlighting the importance of the conditioning regimen for tumor control. © 2003 American Society for Blood and Marrow TransplantationBiology of Blood and Marrow Transplantation 9:189-197 (2003

Venous Admixture in COPD: Pathophysiology and Therapeutic Approaches

Chronic obstructive and interstitial lung diseases impair pulmonary gas exchange leading to wasted ventilation (alveolar dead space) and wasted perfusion (venous admixture). These two fundamental types of abnormality represent opposite ends of the spectrum of ventilation-perfusion mismatch with V˙/Q˙ ratios of infinity and zero. Treatment approaches that improve airway function, reduce air trapping and hyperinflation have received much attention and might be successful at ameliorating the problems associated with high V˙/Q˙. However, in patients with low V˙/Q˙ abnormality in whom venous admixture leads to hypoxemia, there are few therapeutic options. Indeed, some patients are refractory to treatment with supplemental oxygen particularly during exercise. Theoretically these patients could benefit from an intervention that increased mixed venous oxygen content thereby ameliorating the deleterious effects of venous admixture. In this perspective article we discuss the mechanisms whereby venous admixture contributes to hypoxemia and reduced oxygen delivery to tissues. We explore methods which could potentially increase mixed venous oxygen content thus ameliorating the deleterious effects of venous admixture. One such intervention that warrants further investigation is the therapeutic creation of an arterio-venous fistula. Such an approach would be novel, simple and minimally invasive. There is reason to believe that complications would be minor leading to a favorable risk-benefit analysis. This approach to treatment could have significant impact for patients with COPD but should also benefit any patient with chronic hypoxemia that impairs exercise performance

Can We Calculate Mean Arterial Pressure in Humans?

Mean arterial pressure (MAP) is either measured with an oscillometric cuff and then systolic (SBP) and diastolic (DBP) blood pressures are estimated from an unknown algorithm; or SBP and DBP are measured via auscultation and MAP calculated using measures of systolic pressure (SBP), diastolic pressure (DBP), and a form-factor (FF; equation: [(SBP-DBP)*FF]+DBP). The typical FF used is 0.33 though others (0.4) have been proposed. Recent work indicates that estimation of aortic MAP via a FF leads to inaccurate values and should therefore be interpreted with caution, whether this is the case for local MAP is unknown. While the implications for hypertension (HTN) diagnosis are minimal, the calculation of local MAP is essential to the study of blood pressure regulation and exercise hemodynamics in patient populations (e.g. heart failure). PURPOSE: To compare the calculation of local MAP using catheter waveforms and a FF, against MAP derived from the pressure-time integral (PTI; i.e. average pressure across the cardiac cycle) measured via radial arterial catheterization. METHODS: We analyzed radial arterial catheter waveforms from 39 patients (Age: 71±7 years; BMI: 38.4±6.7; Female: 66%; HTN prevalence: 97%) with heart failure with preserved ejection fraction (HFpEF) at rest and during cycling exercise at 20 Watts. We compared the PTI (from the catheter waveform) with the calculation of MAP from the peak and nadir of the same waveforms (5-beat averages) using the 0.33 and 0.4 FF’s in the FF equation. RESULTS: Compared to the PTI (91±13 mmHg), resting MAP was not significantly different when calculated using the 0.33 FF (91±11 mmHg, P\u3e0.999) but was higher when using the 0.4 FF (96±12 mmHg, PCONCLUSION:While the 0.33 FF provides an accurate assessment of MAP on average during rest and exercise in the radial artery in patients with HFpEF, the limits of agreement are large reflecting a lack of precision in measurement at an individual level. Indirect calculations of MAP via a FF may lead to inaccurate conclusions regarding the mechanisms of blood pressure regulation both at rest and during exercise testing in this population

Multicenter Study of High-Dose Daptomycin for Treatment of Enterococcal Infections

Enterococci are among the leading pathogens isolated in hospital-acquired infections. Current antimicrobial options for vancomycin-resistant enterococci (VRE) are limited. Prior data suggests that daptomycin \u3e 6mg/kg/day may be used to treat enterococcal infections. We retrospectively evaluated the effectiveness and safety of high-dose daptomycin (HD-daptomycin) therapy (\u3e 6 mg/kg) in a multicenter cohort of adult patients with enterococcal infections to describe the characteristics and outcomes. Two-hundred and forty-five patients were evaluated. Enterococcus faecium was identified in 175 (71%), followed by 49 (20%) Enterococcus faecalis and 21 (9%) Enterococcus spp., overall 204 (83%) were VRE. Enterococcal infections included bacteremia (173, 71%), intra-abdominal (35, 14%) and bone/joint (25, 10%). The median dose and duration of HD-daptomycin was 8.2 mg/kg/day (IQR 7.7-9.7) and 10 days (IQR 6-15), respectively. Overall clinical success rate was 89% (193/218) and microbiological eradication was observed in 93% (177/191) of patients. The median time to clearance of blood cultures on HD-daptomycin was 3 days (IQR 2-5). Thirty-day all cause mortality rate was 27% and 5 (2%) patients developed daptomycin nonsusceptible enterococcal strains while on HD-daptomycin. Seven patients (3%) had creatine phosphokinase (CPK) elevation, yet no HD-daptomycin regimen was discontinued due to an elevated CPK and all patients were asymptomatic. Overall, there was a high frequency of clinical success and microbiological eradication in patients treated with HD-daptomycin for enterococcal infections, even in patients with complicated and difficult to treat infections. No adverse event-related discontinuation of HD-daptomycin was noted. HD-daptomycin may be an option for the treatment of enterococcal infections