Organic Catalytic Activity as a Method for Agnostic Life Detection

An ideal life detection instrument would have high sensitivity but be insensitive to abiotic processes and would be capable of detecting life with alternate molecular structures. In this study, we propose that catalytic activity can be the basis of a nearly ideal life detection instrument. There are several advantages to catalysis as an agnostic life detection method. Demonstrating catalysis does not necessarily require culturing/growing the alien life and in fact may persist even in dead biomass for some time, and the amplification by catalysis is large even by minute amounts of catalysts and, hence, can be readily detected against abiotic background rates. In specific, we propose a hydrolytic catalysis detection instrument that could detect activity in samples of extraterrestrial organic material from unknown life. The instrument uses chromogenic assay-based detection of various hydrolytic catalytic activities, which are matched to corresponding artificial substrates having the same, chromogenic (preferably fluorescent) upon release, group; D- and L-enantiomers of these substrates can be used to also answer the question whether unknown life is chiral. Since catalysis is a time-proportional product-concentration amplification process, hydrolytic catalytic activity can be measured on a sample of even a minute size, and with instruments based on, for example, optofluidic chip technology.

'Do we know if we need to reduce head impact exposure?': A mixed-methods study highlighting the varied understanding of the long-term risk and consequence of head impact exposure across all stakeholders at the highest level of rugby union

Background

One strategy to prevent and manage concussion is to reduce head impacts, both those resulting in concussion and those that do not. Because objective data on the frequency and intensity of head impacts in rugby union (rugby) are sparse, stakeholders resort to individual perceptions to guide contact training. It is unknown whether there is a level of contact training that is protective in preparing elite players for contact during matches.

Objectives

This study aimed to describe how contact training is managed in elite male rugby, and how staff and players perceive contact training load and head impact load.

Methods

This was a sequential explanatory mixed-methods study. Forty-four directors of rugby, defence coaches, medical and strength/conditioning staff and 23 players across all 13 English Premiership Rugby Union clubs and the National senior team participated in semi-structured focus groups and completed two bespoke questionnaires.

Results

The study identified the varied understanding of what constitutes head impact exposure across all stakeholder groups, resulting in different interpretations and a range of management strategies. The findings suggest that elite clubs conduct low levels of contact training; however, participants believe that some exposure is required to prepare players and that efforts to reduce head impact exposure must allow for individualised contact training prescription.

Conclusion

There is a need for objective data, possibly from instrumented mouthguards to identify activities with a high risk for head impact and possible unintended consequences of reduced exposure to these activities. As data on head impact exposure develop, this must be accompanied with knowledge exchange within the rugby community.

ThermoBase: A database of the phylogeny and physiology of thermophilic and hyperthermophilic organisms

Thermophiles and hyperthermophiles are those organisms which grow at high temperature (> 40°C). The unusual properties of these organisms have received interest in multiple fields of biological research, and have found applications in biotechnology, especially in industrial processes. However, there are few listings of thermophilic and hyperthermophilic organisms and their relevant environmental and physiological data. Such repositories can be used to standardize definitions of thermophile and hyperthermophile limits and tolerances and would mitigate the need for extracting organism data from diverse literature sources across multiple, sometimes loosely related, research fields. Therefore, we have developed ThermoBase, a web-based and freely available database which currently houses comprehensive descriptions for 1238 thermophilic or hyperthermophilic organisms. ThermoBase reports taxonomic, metabolic, environmental, experimental, and physiological information in addition to literature resources. This includes parameters such as coupling ions for chemiosmosis, optimal pH and range, optimal temperature and range, optimal pressure, and optimal salinity. The database interface allows for search features and sorting of parameters. As such, it is the goal of ThermoBase to facilitate and expedite hypothesis generation, literature research, and understanding relating to thermophiles and hyperthermophiles within the scientific community in an accessible and centralized repository. ThermoBase is freely available online at the Astrobiology Habitable Environments Database (AHED; https://ahed.nasa.gov), at the Database Center for Life Science (TogoDB; http://togodb.org/db/thermobase), and in the S1 File.

Outcome after surgical resection for duodenal adenocarcinoma in the UK

BACKGROUND

Factors influencing long-term outcome after surgical resection for duodenal adenocarcinoma are unclear.

METHODS

A prospectively created database was reviewed for patients undergoing surgery for duodenal adenocarcinoma in six UK hepatopancreaticobiliary centres from 2000 to 2013. Factors influencing overall survival and disease-free survival (DFS) were identified by regression analysis.

RESULTS

Resection with curative intent was performed in 150 (84·3 per cent) of 178 patients. The postoperative morbidity rate for these patients was 40·0 per cent and the in-hospital mortality rate was 3·3 per cent. Patients who underwent resection had a better median survival than those who had a palliative surgical procedure (84 versus 8 months; P < 0·001). The 1-, 3- and 5-year overall survival rates for patients who underwent resection were 83·9, 66·7 and 51·2 per cent respectively. Median DFS was 53 months, and 1- and 3-year DFS rates were 80·8 and 56·5 per cent respectively. Multivariable analysis revealed that node status (hazard ratio 1·73, 95 per cent c.i. 1·07 to 2·79; P = 0·006) and lymphovascular invasion (hazard ratio 3·49, 1·83 to 6·64; P = 0·003) were associated with overall survival.

CONCLUSION

Resection of duodenal adenocarcinoma in specialist centres is associated with good long-term survival. Lymphovascular invasion and nodal metastases are independent prognostic indicators.

[Prokaryotic community of subglacial bottom sediments of Antarctic Lake Untersee: detection by cultural and direct microscopic techniques]

The heterotrophic mesophilic component was studied in microbial communities of the samples of frozen regolith collected from the glacier near Lake Untersee collected in 2011 during the joint Russian-American expedition to central Dronning Maud Land (Eastern Antarctica). Cultural techniques revealed high bacterial numbers in the samples. For enumeration of viable cells, the most probable numbers (MPN) method proved more efficient than plating on agar media. Fluorescent in situ hybridization with the relevant oligonucleotide probes revealed members of the groups Eubacteria (Actinobacteria, Firmicutes) and Archaea. Application of the methods of cell resuscitation, such as the use of diluted media and prevention of oxidative stress, did not result in a significant increase in the numbers of viable cells retrieved form subglacial sediment samples. Our previous investigations demonstrated the necessity for special procedures for efficient reactivation of the cells from microbial communities of preserved fossil soil and permafrost samples collected in the Arctic zone. The differences in response to the special resuscitation procedures may reflect the differences in the physiological and morphological state of bacterial cells in microbial communities subject to continuous or periodic low temperatures and dehydration.

Midlatitude ice-rich ground on mars as a target in the search for evidence of life and for in situ resource utilization on human missions

Midlatitude ground ice on Mars is of significant scientific interest for understanding the history and evolution of ice stability on Mars and is relevant for human exploration as a possible in situ resource. For both science and exploration, assessing the astrobiological potential of the ice is important in terms of (1) understanding the potential for life on Mars and (2) evaluating the presence of possible biohazards in advance of human exploration. In the present study, we review the evidence for midlatitude ground ice on Mars, discuss the possible explanations for its occurrence, and assess its potential habitability. During the course of study, we systematically analyzed remote-sensing data sets to determine whether a viable landing site exists in the northern midlatitudes to enable a robotic mission that conducts in situ characterization and searches for evidence of life in the ice. We classified each site according to (1) presence of polygons as a proxy for subsurface ice, (2) presence and abundance of rough topographic obstacles (e.g., large cracks, cliffs, uneven topography), (3) rock density, (4) presence and abundance of large boulders, and (5) presence of craters. We found that a suitable landing site exists within Amazonis Planitia near ground ice that was recently excavated by a meteorite impact.

European experts consensus statement on cystic tumours of the pancreas

Cystic lesions of the pancreas are increasingly recognized. While some lesions show benign behaviour (serous cystic neoplasm), others have an unequivocal malignant potential (mucinous cystic neoplasm, branch- and main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm). European expert pancreatologists provide updated recommendations: diagnostic computerized tomography and/or magnetic resonance imaging are indicated in all patients with cystic lesion of the pancreas. Endoscopic ultrasound with cyst fluid analysis may be used but there is no evidence to suggest this as a routine diagnostic method. The role of pancreatoscopy remains to be established. Resection should be considered in all symptomatic lesions, in mucinous cystic neoplasm, main duct intraductal papillary mucinous neoplasm and solid pseudo-papillary neoplasm as well as in branch duct intraductal papillary mucinous neoplasm with mural nodules, dilated main pancreatic duct >6mm and possibly if rapidly increasing in size. An oncological partial resection should be performed in main duct intraductal papillary mucinous neoplasm and in lesions with a suspicion of malignancy, otherwise organ preserving procedures may be considered. Frozen section of the transection margin in intraductal papillary mucinous neoplasm is suggested. Follow up after resection is recommended for intraductal papillary mucinous neoplasm, solid pseudo-papillary neoplasm and invasive cancer.

Service provision and training for endoscopic ultrasound in the UK

Endoscopic ultrasound (EUS) is a standard procedure that plays an important role in the management of both malignant and benign disease. The development of EUS services in the UK has been haphazard and training inconsistent. The British Society of Gastroenterology has charged a working group with the task of laying down a national framework for how such services might be commissioned, structured and regulated; with particular attention to defining how endoscopist skills might be acquired, assessed and maintained. This report lays out a map for this process and its future revision.

Accuracy of endoscopic ultrasound elastography used for differential diagnosis of focal pancreatic masses: a multicenter study

BACKGROUND AND STUDY AIMS

Endoscopic ultrasound (EUS) elastography represents a new imaging procedure that might characterize the differences of hardness and strain between diseased tissue and normal tissue. The aim of this study was to assess the efficiency of EUS elastography for the differentiation of focal masses in chronic pancreatitis and pancreatic cancer.

PATIENTS AND METHODS

The study group comprised 258 patients with focal pancreatic masses included prospectively at 13 participating centers. Qualitative analysis of the diagnoses made by two expert doctors using all recorded video clips was performed in order to test the interobserver variability. A post-processing software analysis was used to examine the EUS elastography videos by calculating average-hue histograms of individual elastography images. The quantitative information was used to calculate intra-observer variability and the accuracy of the method.

RESULTS

Qualitative analysis of the recorded videos revealed a kappa value of 0.72. Intra-observer variability analysis revealed that the single measure intraclass correlation ranged between 0.86 and 0.94. The average-hue histogram analysis of the data indicated a sensitivity of 93.4 %, a specificity of 66.0 %, a positive predictive value of 92.5 %, a negative predictive value of 68.9 %, and an overall accuracy of 85.4 %, based on a cut-off value of 175. Area under the receiver operating characteristic curve (AUROC) was 0.854 ( P < 0.0001) with a confidence interval of 0.804 - 0.894.

CONCLUSION

The value of quantitative analysis of EUS elastography recordings was proven by good reproducibility of the videos, as well as good parameters of the AUROC analysis. (Clinical Trials.gov identifier: CT00909103).

Microbial colonization of Ca-sulfate crusts in the hyperarid core of the Atacama Desert: implications for the search for life on Mars

The scarcity of liquid water in the hyperarid core of the Atacama Desert makes this region one of the most challenging environments for life on Earth. The low numbers of microbial cells in the soils suggest that within the Atacama Desert lies the dry limit for life on our planet. Here, we show that the Ca-sulfate crusts of this hyperarid core are the habitats of lithobiontic micro-organisms. This microporous, translucent substrate is colonized by epilithic lichens, as well as endolithic free-living algae, fungal hyphae, cyanobacteria and non photosynthetic bacteria. We also report a novel type of endolithic community, "hypoendoliths", colonizing the undermost layer of the crusts. The colonization of gypsum crusts within the hyperarid core appears to be controlled by the moisture regime. Our data shows that the threshold for colonization is crossed within the dry core, with abundant colonization in gypsum crusts at one study site, while crusts at a drier site are virtually devoid of life. We show that the cumulative time in 1 year of relative humidity (RH) above 60% is the best parameter to explain the difference in colonization between both sites. This is supported by controlled humidity experiments, where we show that colonies of endolithic cyanobacteria in the Ca-sulfate crust undergo imbibition process at RH >60%. Assuming that life once arose on Mars, it is conceivable that Martian micro-organisms sought refuge in similar isolated evaporite microenvironments during their last struggle for life as their planet turned arid.

Reduced connectivity of the auditory cortex in patients with auditory hallucinations: a resting state functional magnetic resonance imaging study

BACKGROUND

Previous research has reported auditory processing deficits that are specific to schizophrenia patients with a history of auditory hallucinations (AH). One explanation for these findings is that there are abnormalities in the interhemispheric connectivity of auditory cortex pathways in AH patients; as yet this explanation has not been experimentally investigated. We assessed the interhemispheric connectivity of both primary (A1) and secondary (A2) auditory cortices in n=13 AH patients, n=13 schizophrenia patients without auditory hallucinations (non-AH) and n=16 healthy controls using functional connectivity measures from functional magnetic resonance imaging (fMRI) data.

METHOD

Functional connectivity was estimated from resting state fMRI data using regions of interest defined for each participant based on functional activation maps in response to passive listening to words. Additionally, stimulus-induced responses were regressed out of the stimulus data and the functional connectivity was estimated for the same regions to investigate the reliability of the estimates.

RESULTS

AH patients had significantly reduced interhemispheric connectivity in both A1 and A2 when compared with non-AH patients and healthy controls. The latter two groups did not show any differences in functional connectivity. Further, this pattern of findings was similar across the two datasets, indicating the reliability of our estimates.

CONCLUSIONS

These data have identified a trait deficit specific to AH patients. Since this deficit was characterized within both A1 and A2 it is expected to result in the disruption of multiple auditory functions, for example, the integration of basic auditory information between hemispheres (via A1) and higher-order language processing abilities (via A2).

Substance P activates a non-selective cation channel in murine pacemaker ICC

Interstitial cells of Cajal (ICC) associated with Auerbach's plexus in the small intestine, provide pacemaker activity to orchestrate peristalsis and mixing. Despite the close apposition between ICC and enteric nerves, little is known about the neural regulation of pacemaker activity. The present study pursues the hypothesis that substance P can affect pacemaker activity through action on non-selective cation channels. Cell-attached and inside-out patch clamp studies were performed on isolated ICC in short-term cultures that provided evidence that substance P increases open probability or initiates activity in non-selective cation channels in ICC. The single-channel conductance is approximately 25 pS and in the on-cell configuration the activity can occur in a rhythmic fashion. Patches contained 1-10 channels and were most often accompanied by a approximately 12 pS chloride channel that was also activated by substance P. In a recently developed preparation that allows patch clamping in ICC in their natural environment within tissue, i.e. in situ, the presence of the channel and substance P activation was confirmed. The non-selective cation channel is one of the channels that initiate intestinal pacemaker activity and the present study provides further single-channel data on this critical channel. Because of the close proximity of enteric motor and sensory nerves to ICC, these data provide a potential mechanism underlying neural regulation of pacemaker activity. The data also indicate that neurokinergic pharmacology is a promising avenue for excitation of the intestinal pacemaker system.

The Greater Involvement of People Living with AIDS principle: theory versus practice in Ontario's HIV/AIDS community-based research sector

Drawing on the Greater Involvement of People with HIV/AIDS (GIPA) principle, the HIV/AIDS movement began to "democratize" research in Canada in the mid-1990s. To date, there is little evidence about the success of the community-based research (CBR) movement in relation to the implementation of GIPA. We draw on findings from a larger study examining barriers and facilitating factors in relation to HIV-related CBR in Ontario, Canada. An online survey was completed by 39 senior managers in Ontario AIDS service organizations (ASOs). Twenty-five in-depth, semi-structured interviews were then conducted to further explore the survey findings. Survey respondents reported that, compared to researchers and frontline service providers, people living with HIV/AIDS (PLWHA) tended to be the least involved in all stages (input, process and outcome) of CBR projects. AIDS service organizations with a mandate that included serving rural and urban communities reported even lower levels of PLWHA involvement in CBR. Qualitative data reveal complex barriers that make meaningful PLWHA engagement in CBR difficult, including: HIV-related stigma; health-related challenges; "credentialism"; lack of capacity to engage in research; other issues taking priority; and mistrust of researchers. Facilitating factors included valuing lived experience; training and mentoring opportunities; financial compensation; trust building; and accommodating PLWHA's needs. While there is strong support for the GIPA principles in theory, practice lags far behind.

Exposure to noise in orthopaedic theatres--do we need protection?

AIM

To detect noise levels, generated by high-powered tools in orthopaedic theatres at varying distances from the operating site, and its impact on hearing in staff and patients.

METHODS

Sound-level meter was used to measure the sound level generated by various high-powered tools in routine orthopaedic procedures, at varying distances from the operating site. These recorded noise levels were compared against the UK noise safety guidelines.

RESULT

We found that the noise generated was often significantly higher than the safety guidelines.

CONCLUSION

Noise levels in orthopaedic theatres can be at unacceptable levels, which could potentially lead to hearing problems in the staff and patients. We believe that all patients, especially the elderly patients, (who are more prone to hearing problems) should have hearing protection during orthopaedic operations that use high-powered tools. Surgeons and scrubbed theatre staff should take precautions.

Drilling systems for extraterrestrial subsurface exploration

Drilling consists of 2 processes: breaking the formation with a bit and removing the drilled cuttings. In rotary drilling, rotational speed and weight on bit are used to control drilling, and the optimization of these parameters can markedly improve drilling performance. Although fluids are used for cuttings removal in terrestrial drilling, most planetary drilling systems conduct dry drilling with an auger. Chip removal via water-ice sublimation (when excavating water-ice-bound formations at pressure below the triple point of water) and pneumatic systems are also possible. Pneumatic systems use the gas or vaporization products of a high-density liquid brought from Earth, gas provided by an in situ compressor, or combustion products of a monopropellant. Drill bits can be divided into coring bits, which excavate an annular shaped hole, and full-faced bits. While cylindrical cores are generally superior as scientific samples, and coring drills have better performance characteristics, full-faced bits are simpler systems because the handling of a core requires a very complex robotic mechanism. The greatest constraints to extraterrestrial drilling are (1) the extreme environmental conditions, such as temperature, dust, and pressure; (2) the light-time communications delay, which necessitates highly autonomous systems; and (3) the mission and science constraints, such as mass and power budgets and the types of drilled samples needed for scientific analysis. A classification scheme based on drilling depth is proposed. Each of the 4 depth categories (surface drills, 1-meter class drills, 10-meter class drills, and deep drills) has distinct technological profiles and scientific ramifications.

Safety and efficacy of retreating follicular non-Hodgkin’s lymphoma (NHL) with 90Y ibritumomab tiuxetan

17528

Background: There is no data regarding safety and efficacy of treating follicular NHL patients with a second course of 90Y ibritumomab tiuxetan (Zevalin). Methods: Patients with follicular NHL who received 2 courses of Zevalin therapy were identified nationally, and data was retrospectively collected. Results: 10 patients (pts) (mean age 62.5 years, 48–91) were identified. Prior to the first Zevalin, all pts received chemotherapy (mean 2.4 courses, 1–5), 3/10 auto-PBSCT, and 4/10 external beam radiotherapy(ebRT). After the initial course of treatment, the mean time to nadir for the anemia was 7.9 weeks (wks)(4–13), neutropenia was 6.7 wks (4–10); and thrombocytopenia was 5.2 wks (4–8). 1 pt required growth factor support and transfusions; 2 had an incomplete recovery of platelet count at 23 and 30 wks (76,000 and 126,000/μl). Hematologic toxicity and grades are in the table below. Prior to the second course of Zevalin 2 pts received ebRT, 1 received 131I tositumomab, and 3 received chemotherapy (1–5 regimens). The median time to the second Zevalin course was 613 days (183–1,300). After the second course of Zevalin, the mean time to nadir for the anemia was 8.2 wks (2–25); neutropenia was 6.7 wks (4–10); and thrombocytopenia was 5.5 wks (4–7). 4/10 pts required growth factor support, 2 required transfusions, 3 had incomplete recovery of platelet count and early progression, 2 pts had a maximum recovery of their platelet count at 29 and 40 wks (143,000 and 144,000/μl). There were no infectious or bleeding complications with either course of Zevalin. No secondary myelodysplastic syndrome or acute leukemia were reported. Conclusions: Retreating patients with follicular NHL with a second course of Zevalin is tolerable with substantial evidence of clinical efficacy. This data warrants further evaluation of Zevalin retreatment in a clinical trial.

[Table: see text]

[Table: see text]

Urinary trypsinogen activation peptide as a marker of severe acute pancreatitis

BACKGROUND

Trypsinogen activation peptide (TAP) may be an early marker of severe pancreatitis. Previous studies have included all patients with organ failure in the group with severe pancreatitis, although patients with transient organ failure may have a good prognosis. The aim of this study was to determine the value of urinary TAP estimation for prediction of severity of acute pancreatitis, and to validate use of several markers of prediction of severity against a new, stringent definition of severity.

METHODS

Patients with acute pancreatitis were recruited within 24 h of onset of symptoms. Urine and blood samples were collected for 24 h, and Acute Physiology And Chronic Health Evaluation (APACHE) II (24 h), Ranson (48 h) and Glasgow (48 h) scores were calculated. Severe acute pancreatitis was defined by the presence of a local complication or the presence of organ failure for more than 48 h.

RESULTS

Urinary TAP levels were significantly greater in patients with severe pancreatitis than in those with mild disease during the first 36 h of admission. The highest of three estimations of TAP in the first 24 h was as effective as APACHE II at 24 h in predicting severity. At 24 h after admission, urinary TAP was better than C-reactive protein (CRP) in predicting severity. The combination of TAP and CRP at 24 h allowed identification of high- and low-risk groups. The new definition of severity excluded 24 of 190 patients with transient organ failure; none of these patients died.

CONCLUSION

Use of TAP improved early prediction of the severity of acute pancreatitis. Organ failure that resolves within 48 h does not signify a severe attack of acute pancreatitis.

An iterative approach to novel polyamines via nucleophilic ring-opening of aziridinium ions with β-amino alcohols

An iterative procedure for the synthesis of a novel class of synthetic polyamines has been developed, utilising the regioselective ring-opening of aziridinium ion intermediates; facile N-allyl deprotection of intermediate polyamines allows the rapid construction of high molecular weight, stereochemically defined compounds in a convergent manner.

Estimation of fruit and vegetable intake using a two-item dietary questionnaire: a potential tool for primary health care workers

BACKGROUND AND AIM

High fruit and vegetable intake is associated with health benefits for cancer and cardiovascular disease. An increase is therefore integral in recommendations for the prevention of chronic disease. However, measuring intake requires either extensive dietary assessment or the measurement of specific bio-markers which is neither cheap nor feasible for the routine assessment of an individual's diet in a community or primary care setting. Within the context of a study evaluating a dietary counselling programme to increase fruit and vegetable intake our aim was to assess the use of a simple tool to estimate fruit and vegetable intake.

METHODS AND RESULTS

We studied associations between bio-markers [plasma ascorbic acid, beta-carotene and alpha-tocopherol 24-hour urinary potassium excretion] and a two-item fruit and vegetable consumption questionnaire in 271 subjects (105 men and 166 women), aged 18 to 70 years. After controlling for age, sex, vitamin supplement use, smoking and body mass, those reporting a daily intake of > or = 5 portions of fruit and vegetables had higher potassium excretion (difference 15.6 [95% confidence interval: 6.2 to 25.0] mmol/24 h), urinary potassium/creatinine ratio (1.2 [0.5 to 2.0]) and plasma vitamin C (10.0 [-0.9 to 20.8] mumol/L) than those reporting < or = 2.5 portions per day. beta-carotene (p = 0.04), vitamin C (p = 0.01) and potassium excretion (p < 0.001) were associated with fruit rather than vegetable intake. The two-item questionnaire had high specificity; over 3/4 of participants who reported low intake also had bio-markers below the upper third of the distribution.

CONCLUSION

Self report of fruit and vegetable intake through a simple questionnaire is confirmed by bio-markers for those eating less than five portions of fruit and vegetables a day. Although the tool is amenable to improvements for the detection of vegetable portions, it may prove useful for monitoring dietary preventive approaches in primary care without the use of invasive and costly biochemical measurements.