Effects of heavy ion particle irradiation on spore germination of bacillus spp. From extremely hot and cold environments

Extremophiles are optimal models in experimentally addressing questions about the effects of cosmic radiation on biological systems. The resistance to high charge energy (HZE) particles, and helium (He) ions and iron (Fe) ions (LET at 2.2 and 200 keV/µm, respectively, until 1000 Gy), of spores from two thermophiles, Bacillus horneckiae SBP3 and Bacillus licheniformis T14, and two psychrotolerants, Bacillus sp. A34 and A43, was investigated. Spores survived He irradiation better, whereas they were more sensitive to Fe irradiation (until 500 Gy), with spores from thermophiles being more resistant to irradiations than psychrotolerants. The survived spores showed different germination kinetics, depending on the type/dose of irradiation and the germinant used. After exposure to He 1000 Gy, D-glucose increased the lag time of thermophilic spores and induced germination of psychrotolerants, whereas L-alanine and L-valine increased the germination efficiency, except alanine for A43. FTIR spectra showed important modifications to the structural components of spores after Fe irradiation at 250 Gy, which could explain the block in spore germination, whereas minor changes were observed after He radiation that could be related to the increased permeability of the inner membranes and alterations of receptor complex structures. Our results give new insights on HZE resistance of extremophiles that are useful in different contexts, including astrobiology

Diagnostic delay and complications for older adults with multiple myeloma

Increased attention to timely diagnosis motivated us to study 5483 patients diagnosed with multiple myeloma using Medicare claims linked to tumor registries in the Surveillance, Epidemiology and End Results programme. We calculated the time between initial visits for anemia or back pain and for myeloma diagnosis, and used logistic regression to predict the likelihood of diagnostic delay, and also the likelihood of renal or skeletal complications. The median time between sign or symptom and myeloma diagnosis was 99 days. Patients with anemia, back pain and comorbidities were more likely to experience diagnostic delay (OR 1.6, 95% CI 1.3-2.0). Diagnosis while hospitalised (OR 2.5, 95% CI 2.2-2.9) and chemotherapy treatment within 6 months of diagnosis (OR 1.4, 95% CI 1.2-1.6) significantly predicted complications; diagnostic delay did not (OR 0.9, 95% CI 0.8-1.1). Our data suggest that complications are more strongly associated with health status and myeloma severity than with diagnostic delays.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94124/1/Diagnostic delay and complications for older adults with multiple myeloma.pd

Delays in referral and diagnosis for chronic hematological malignancies: A literature review

To better understand the extent of diagnostic and referral delays from primary care providers (PCPs) for chronic hematologic malignancies, causes of these delays, and their possible effects on cancer outcomes, an extensive review of the literature was performed. Over 50 studies were reviewed, including many that concern delays in referral and diagnosis for solid tumors, as there was only sparse literature on delays specific to the liquid tumors. Delays for some chronic hematologic malignancies have been documented, mainly in centralized health care systems. Possible reasons for delays include PCPs' lack of exposure to hematologic malignancies, limited knowledge of associated signs and symptoms, and a reliance on patient symptoms to prompt referral (as opposed to signs and screening). Patient characteristics such as age, gender and race-ethnicity are also likely to play a role, although it is unclear if these exert their effect primarily via patient or provider mechanisms. Unfortunately, the outcomes associated with such delays are largely unreported, possibly because delay is complex to define and difficult to measure.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94128/1/Delays in referral and diagnosis for chronic hematological malignancies A literature review.pd

Disaccharide topology induces slow down in local water dynamics

Molecular level insight into water structure and structural dynamics near proteins, lipids and nucleic acids is critical to the quantitative understanding of many biophysical processes. Un- fortunately, understanding hydration and hydration dynamics around such large molecules is challenging because of the necessity of deconvoluting the effects of topography and chemical heterogeneity. Here we study, via classical all atom simulation, water structure and structural dynamics around two biologically relevant solutes large enough to have significant chemical and topological heterogeneity but small enough to be computationally tractable: the disaccharides Kojibiose and Trehalose. We find both molecules to be strongly amphiphilic (as quantified from normalized local density fluctuations) and to induce nonuniform local slowdown in water translational and rotational motion. Detailed analysis of the rotational slowdown shows that while the rotational mechanism is similar to that previously identified in other aqueous systems by Laage, Hynes and coworkers, two novel characteristics are observed: broadening of the transition state during hydrogen bond exchange (water rotation) and a subpopulation of water for which rotation is slowed because of hindered access of the new accepting water molecule to the transition state. Both of these characteristics are expected to be generic features of water rotation around larger biomolecules and, taken together, emphasize the difficulty in transferring insight into water rotation around small molecules to much larger amphiphilic solutes.This work is part of the research program of the “Stichting voor Fundamenteel Onderzoek der Materie (FOM)” which is financially supported by the “Nederlandse organisatie voor Wetenschap- pelijk Onderzoek (NWO)”. Further financial support was provided by a Marie Curie Incoming International Fellowship (RKC). We gratefully acknowledge SARA, the Dutch center for high- performance computing, for computational time and Huib Bakker and Daan Frenkel for useful critical reviews on an earlier version of this work. We thank two anonymous reviewers for their excellent work, especially for bringing to our attention calculations done on the transition state geometry of dimers and the overstructuring of the O-O radial distribution function of SPC/E water