The identification of sulfide oxidation as a potential metabolism driving primary production on late Noachian Mars.

The transition of the martian climate from the wet Noachian era to the dry Hesperian (4.1-3.0 Gya) likely resulted in saline surface waters that were rich in sulfur species. Terrestrial analogue environments that possess a similar chemistry to these proposed waters can be used to develop an understanding of the diversity of microorganisms that could have persisted on Mars under such conditions. Here, we report on the chemistry and microbial community of the highly reducing sediment of Colour Peak springs, a sulfidic and saline spring system located within the Canadian High Arctic. DNA and cDNA 16S rRNA gene profiling demonstrated that the microbial community was dominated by sulfur oxidising bacteria, suggesting that primary production in the sediment was driven by chemolithoautotrophic sulfur oxidation. It is possible that the sulfur oxidising bacteria also supported the persistence of the additional taxa. Gibbs energy values calculated for the brines, based on the chemistry of Gale crater, suggested that the oxidation of reduced sulfur species was an energetically viable metabolism for life on early Mars.

Low rates of endocarditis in healthcare-associated Staphylococcus aureus bacteremia suggest that echocardiography might not always be required.

Healthcare-associated Staphylococcus aureus bacteremia (HA-SAB) is an increasingly frequently observed complication of medical treatment. Current guidelines recommend evaluation with echocardiography and preferably transesophageal echocardiography for the exclusion of infectious endocarditis (IE). We performed a retrospective analysis of all patients with HA-SAB between 1 January 2007 and 31 July 2012. Patients were divided into those with a high degree of clinical suspicion of IE (prosthetic intracardiac device, hemodialysis or positive blood cultures for 4 days or more) or those with a low degree of clinical suspicion of IE (absence of high-risk features based on previous literature as strong indicators of endocarditis). Three hundred and fifty-eight patients with HA-SAB were evaluated to determine the prevalence of IE, including 298 (83 %) who had echocardiography. Fourteen patients (4 %) had a final diagnosis of IE after echocardiography. In the group with a high degree of clinical suspicion 11 out of 84 patients (13 %) had IE. In the group with a low degree of clinical suspicion group 3 out 274 patients (1.1 %) had IE. HA-SAB has a low rate of IE, especially in the absence of high-risk features such as prolonged bacteremia, intracardiac prosthetic devices, and hemodialysis. Echocardiographic imaging in this low-risk population of patients is rarely helpful and may generally be avoided, although careful clinical follow-up is warranted. Patients with HA-SAB who have mechanical valves, intracardiac devices, prolonged bacteremia or dialysis dependency have a high incidence of IE and should be evaluated thoroughly using echocardiography.

Comparative safety of atypical antipsychotics and the risk of pneumonia in the elderly.

PURPOSE: Previous studies have documented increased risk of pneumonia with antipsychotic use in the elderly; however, differential risk across individual atypical antipsychotics remains unaddressed. This study examines the effect of individual atypical antipsychotics on risk of pneumonia in elderly patients. METHODS: This retrospective cohort study was conducted using a large claims database. The study population included new users of atypical antipsychotics (≥65 years). The multiple propensity-score adjusted survival model was used to examine risk of pneumonia within a 1-year follow-up period. RESULTS: A total of 92 234 patients newly prescribed atypical antipsychotic medication were identified. Of these, 41 780 (45.30%) were quetiapine users, 31 048 (33.66%) risperidone users, 11 375 (12.33%) olanzapine users, 6790 (7.36%) aripiprazole users, and 1241 (1.35%) ziprasidone users. Within the 1-year follow-up period, 12 411 (13.46%) patients taking atypical antipsychotics had a diagnosis of pneumonia. The multiple propensity-score-adjusted survival model revealed increased risk of pneumonia with the use of risperidone (hazard ratios (HR) 1.14, 95%CI 1.10-1.18) and olanzapine (HR 1.10, 95%CI 1.04-1.16) compared with the use of quetiapine. CONCLUSION: This large population-based study suggests that use of risperidone and olanzapine increases risk of pneumonia compared with use of quetiapine in elderly patients. This study provides new information on the comparative risk of pneumonia associated with different atypical antipsychotics in the elderly to support optimal treatment decisions.

Non-tuberculous mycobacterial infections after solid organ transplantation: a survival analysis.

The relationship of non-tuberculous mycobacterial (NTM) infections and survival among solid organ transplant recipients is unknown. We conducted a retrospective cohort study to measure the impact of NTM infection on survival in this patient population, comparing the effect of Mycobacterium abscessus infection with that of infections due to other pathogenic NTM species. We identified 33 patients with NTM infection post-transplantation, 18 with infection that was diagnosed within the first year. Although drug resistance was common among M. abscessus isolates, patients with M. abscessus infection did not have increased mortality compared with patients with other types of NTM infections (p 0.64). In contrast, we observed a significant association overall between early NTM infection and 3-year mortality post-transplantation (hazard ratio 8.76, 95% CI 2.69-28.57). The mortality burden of NTM infection following transplantation may be due to factors other than the virulence of the organisms. Multicentre studies are needed to identify the optimal approach for diagnosing and treating these uncommon but serious infections.

Development of the CASH assessment tool to address existential concerns in patients with serious illness.

INTRODUCTION: Existential suffering in patients with serious illness significantly impacts quality of life, yet it remains a challenge to define, assess, and manage adequately. Improving upon understanding and practice in the existential domain is a topic of interest for palliative care providers. METHODS: As a quality improvement project, our palliative care team created an existential assessment tool utilizing a dialogue-oriented approach with four questions designed to identify sources of existential distress as well as strengths and challenges in coping with this distress. The tool utilized the mnemonic CASH, with each letter representing the core objective of the question. Providers who requested the palliative care consult were asked to evaluate the CASH assessment. On completion of the project, palliative care consultants evaluated the appropriateness of the CASH assessment tool. RESULTS: Patient responses to the CASH questions were insightful and reflected their beliefs, priorities, and concerns. Eight of nine providers found that the assessment enabled understanding of their patient. Seven noted a positive impact on their practice, and five reported an improvement in patient care after the assessment. The palliative care consultants who used the tool enjoyed using it, and half of them suggested changes to patient care based on their assessment. The most common reasons for not using the CASH assessment were inappropriateness to the consult, lack of perceived patient/caregiver receptiveness, or consultation service too busy. CONCLUSION: Our quality improvement project demonstrated that the CASH assessment tool is useful in ascertaining existential concerns of patients with serious illness. It enhances patient care by the primary team as well as the palliative care team. As a brief set of questions with an easy-to-remember mnemonic, the CASH assessment tool is feasible for a busy palliative consult service. Furthermore, the positive results of this project merit more rigorous evaluation of the CASH assessment tool in the future.

Reattachment of the proximal hamstring origin: outcome in patients with partial and complete tears.

PURPOSE: To assess the subjective and functional outcome in complete and partial injuries, both acute and chronic. METHODS: One hundred and thirty-two consecutive proximal hamstring reattachments were performed by a single surgeon between 1999 and 2009. The mean age at the time of operation was 42.5 years (SD 12.2), the mean duration of follow-up was 53.8 months (SD 19.5), and all patients with a minimum 2-year follow-up were included in the study. Patients were reviewed independently. Functional outcome was evaluated using quantitative assessments of pre-operative and postoperative hamstring strength and endurance, while subjective outcome was undertaken at the latest follow-up using a three-tier questionnaire. RESULTS: The most common cause of injury was waterskiing (29 patients). There were 96 complete injuries and 36 partial injuries. Overall, 112 of 132 patients rated their result as good/excellent, 91 had returned to their pre-injury level of sporting activity, and 114 said that they would undergo surgery again. Mean postoperative hamstring strength was 83 %, and mean hamstring endurance was 108 % compared to the contralateral limb. Patients with complete injuries and those operated and those operated on acutely (<6 weeks) were more likely to have a good/excellent result. There was no significant correlation between time to repair, type of injury (partial vs. complete) and functional outcome. CONCLUSION: Good to excellent results can be expected in the majority of patients, following surgical reattachment. Surgery is well tolerated with the vast majority of patients, reporting that they would undergo surgery again. LEVEL OF EVIDENCE: IV.

Risk factors for nontuberculous mycobacterial infections in solid organ transplant recipients: a case-control study.

BACKGROUND: The epidemiology of nontuberculous mycobacteria (NTM) disease in solid organ transplant recipients is poorly defined. METHODS: We identified all solid organ transplant recipients with NTM disease at a single center over a 7.5-year period, and collected data on patient demographics, co-morbidities, immunosuppressive medications, and rejection. We conducted a case-control study to identify risk factors for disease, matching 3 control patients to each case patient by date of transplantation. RESULTS: A total of 34 cases of NTM disease occurred during the study period, involving 6 single lung, 13 bilateral lung, 8 heart, 4 liver, 2 kidney, and 1 pancreas-kidney recipients. Cases were predominantly male (24/34), with a median age of 55 years (interquartile range [IQR]: 46-61 years), and developed after a median of 8 months post transplantation (IQR: 2-87 months). Mycobacterium abscessus and Mycobacterium avium complex were the most common pathogens, and the lung (including pleura) was the most common site of disease. In the adjusted case-control analysis, lung transplant recipients had the highest risk of NTM disease. CONCLUSIONS: Additional studies are needed to evaluate the role of targeted surveillance measures for NTM disease in high-risk patients, particularly lung transplant recipients, and to characterize the mechanisms of disease acquisition.

Oral ketamine for sickle cell crisis pain refractory to opioids.

There is literature demonstrating that the N-methyl-d-aspartate (NMDA) receptor antagonist ketamine has analgesic properties that can be used as an adjuvant to opiates for pain relief in multiple various conditions and pain states. However, there is a lack of published information on ketamine used in persons with sickle cell disease in acute pain crises. The Virginia Commonwealth University Palliative Care team was consulted on a 38-year-old African American female with sickle cell thalassemia in severe acute pain crisis overlying chronic pain related to her disease. Pain control was unable to be achieved with escalating doses of opiates and other adjuvant medications. The patient responded well to an intravenous test dose of ketamine and was subsequently placed on an oral regimen of ketamine in addition to opiates. In the 24-hour period following ketamine initiation, the patient's pain was able to be controlled on decreased amounts of opiates. She was eventually transitioned to an oral opiate and ketamine regimen, which allowed her to be discharged home with pain levels close to her baseline and the ability to function and perform all activities of daily living.

Comparison of custom-moulded ankle orthosis with hinged joints and off-the-shelf ankle braces in preventing ankle sprain in lateral cutting movements.

BACKGROUND: A custom moulded ankle orthosis with hinged joints potentially offers a better control over the subtalar joint and the ankle joint during lateral cutting movements, due to total contact design and increase in material strength. OBJECTIVES: To test the above hypothesis by comparing it to three other available orthoses. STUDY DESIGN: Repeated measures. METHODS: Eight subjects with a history of ankle sprains (Grade 2), and 11 subjects without such history performed lateral cutting movements in four test conditions: 1) non-orthotic, 2) custom-moulded ankle orthosis with hinges, 3) Sport-Stirrup, and 4) elastic ankle sleeve with plastic support. A VICON motion analysis system was used to study the motions at the ankle and subtalar joints. RESULTS: The custom-moulded ankle orthosis significantly lowered the inversion angle at initial contact (p = 0.006) and the peak inversion angle (p = 0.000) during lateral cutting movements in comparison to non-orthotic condition, while the other two orthoses did not. The three orthoses did not affect the plantarflexion motions, which had been suggested by previous studies to be important in shock wave attenuation. CONCLUSIONS: The custom-moulded ankle orthosis with hinges could better control inversion and thus expected to better prevent ankle sprain in lateral cutting movements. CLINICAL RELEVANCE: Custom-moulded ankle orthoses are not commonly used in preventing ankle sprains. This study raises the awareness of the use of custom-moulded ankle orthoses which are expected to better prevent ankle sprains.

Risk factors and clinical outcomes of cytomegalovirus disease occurring more than one year post solid organ transplantation.

BACKGROUND: Cytomegalovirus (CMV) disease typically occurs during the first year after solid organ transplantation, after cessation of antiviral prophylaxis. CMV occurring after the first year is uncommon and not well described. METHODS: We conducted a case-control study to identify potential risk factors and a retrospective cohort study to evaluate 1-month mortality in solid organ transplant (SOT) recipients who developed CMV disease after the first year post transplant, or "very late CMV" (VLCMV), compared with those developing CMV within the first year (CMV Y1), adjusting for demographics, donor and recipient CMV serostatus, immunosuppression, rejection, and co-morbidities. RESULTS: We identified 85 SOT recipients with CMV disease at a single transplant center between January 2006 and October 2008: 23 (27%) had VLCMV and 62 (73%) had CMV Y1. Heart transplantation was independently associated with increased risk (adjusted odd ratio [OR] 4.11; 95% confidence interval [CI] 1.34-12.61; P = 0.01) for VLCMV. Patients with VLCMV had increased 1-month mortality (unadjusted OR 5.39; 95% CI 1.06-27.48; P = 0.02). Mortality was uncommonly attributable to CMV. CONCLUSIONS: CMV disease continues to occur after the first year post solid organ transplantation, particularly in heart transplant recipients, and can be associated with poor outcomes. CMV should be suspected in patients with symptoms or laboratory findings consistent with CMV, even if the patients present >1 year post transplant.

The role of Plantaris Longus in Achilles tendinopathy: a biomechanical study.

BACKGROUND: The Plantaris Longus Tendon (PLT) may be implicated in Achilles (AT) tendinopathy. Different mechanical characteristics may be the cause. This study is designed to measure these. METHODS: Six PLT and six AT were harvested from frozen cadavers (aged 65-88). Samples were stretched to failure using a Minimat 2000™ (Rheometric Scientific Inc.). Force and elongation were recorded. Calculated tangent stiffness, failure stress and strain were obtained. Averaged mechanical properties were compared using paired, one-tailed t-tests. RESULTS: Mean stiffness was higher (p<0.001) in the PLT, measuring 5.71 N/mm (4.68-6.64), compared with 1.73 N/mm (1.40-2.22) in AT. Failure stress was also higher (p<0.01) in PLT: 1.42 N/mm(2) (0.86-2.23) AT: 0.20 N/mm(2) (0.16-0.25). Failure strain was less (p<0.05) in PLT: 14.1% (11.5-16.8) than AT: 21.8% (14.9-37.9). CONCLUSIONS: The PLT is stiffer, stronger than AT, demonstrating potential for relative movement under load. The stiffer PLT could tether AT and initiate an inflammatory response.

Impact of phlebotomine sand flies on United State military operations at Tallil Air Base, Iraq: 6. Evaluation of insecticides for the control of sand flies.

We conducted a series of field experiments in 2003 and 2004 to evaluate the efficacy of a variety of insecticides and insecticide application technologies for the control of phlebotomine sand flies at Tallil Airbase, Iraq. During the experiments, 53,263 sand flies were collected. The experiments evaluated the following: (1) routine sand fly control operations using a variety of residual and area-wide insecticides; (2) a combination of five different insecticide application methods in and around tents; (3) residual application of lambda-cyhalothrin and ultra-low volume application of pyrethrins in houses; (4) carbaryl and lambda-cyhalothrin applied as barrier sprays; (5) a deltamethrin-impregnated fence; (6) lambda-cyhalothrin applied as a residual spray in concrete manholes; (7) deltamethrin-treated flooring in tents; and 8) ultra-low volume-applied malathion. Although some of the experiments resulted in limited reductions in the number of sand flies collected in light traps, in no instance did we completely eliminate sand flies or reduce populations for a sustained period. The implications of these findings are discussed.

When cancer pain breaks through, what can you do?

Breakthrough pain in cancer patients can be very difficult to manage, primarily because of its heterogeneous and fleeting nature, so careful assessment is imperative to finding an adequate treatment regimen. Only a paucity of good research exists to support current interventions, and additional viable options need to be discovered. Oncology nurses must play an integral role in improving the treatment of breakthrough pain-one patient, one in-service for colleagues, and one clinical research study at a time.

A comparison of patient based outcome following knee arthrodesis for failed total knee arthroplasty and revision knee arthroplasty.

Arthrodesis of the knee is an infrequently performed operation perceived by both patient and surgeon to have a poor outcome. This study compares functional outcome of knee arthrodesis following failed primary arthroplasty with that of revision knee arthroplasty in a matched patient group. Outcome was measured using the SF12 and Oxford Knee Score. Twelve patients underwent arthrodesis, of which eight were available for functional review at a mean of 53 months. No significant difference was found between the outcome scores of the two groups, although it is recognised that the numbers involved were low. Arthrodesis of the knee may be considered as a surgical option following failed arthroplasty when factors are present that may mitigate against an optimal result following revision knee arthroplasty.

Student nurse practitioners--a rite of passage? The universality of Van Gennep's model of social transition.

Whilst much has been written on the competence and clinical effectiveness of qualified nurse practitioners, the literature reveals little on the educational experience of student nurse practitioners. This paper reviews an ethnography that examined, over a two-year period, the experiences of student nurse practitioners undertaking a clinical degree programme (B.Sc. (Hons) Nurse Practitioner). The findings revealed the student nurse practitioner experience as a composite of social and cultural transitions, and subsequently Van Gennep's (Van Gennep, A., 1960. The Rites of Passage (Trans). Routledge & Kegan Paul, London) rite of passage model was found to have similarity with this emergent model. Finally, it was noted that, whilst social transition is modelled in the literature in many ways, the stages of a rite of passage had universal application.

Impact of phlebotomine sand flies on U.S. Military operations at Tallil Air Base, Iraq: 2. Temporal and geographic distribution of sand flies.

CDC miniature light traps were used to evaluate the general biology of phlebotomine sand flies from April 2003 to November 2004 at Tallil Air Base, Iraq. Factors evaluated include species diversity and temporal (daily and seasonal) and geographic distribution of the sand flies. In addition, the abundance of sand flies inside and outside tents and buildings was observed. In total, 61,630 sand flies were collected during 1,174 trap nights (mean 52 per trap, range 0-1,161), with 90% of traps containing sand flies. Sand fly numbers were low in April, rose through May, were highest from mid-June to early September, and dropped rapidly in late September and October. More than 70% of the sand flies were female, and of these sand flies, 8% contained visible blood. Phlebotomus alexandri Sinton, Phlebotomus papatasi Scopoli, Phlebotomus sergenti Parrot, and Sergentomyia spp. accounted for 30, 24, 1, and 45% of the sand flies that were identified, respectively. P. alexandri was more abundant earlier in the season (April and May) than P. papatasi, whereas P. papatasi predominated later in the season (August and September). Studies on the nocturnal activity of sand flies indicated that they were most active early in the evening during the cooler months, whereas they were more active in the middle of the night during the hotter months. Light traps placed inside tents with and without air conditioners collected 83 and 70% fewer sand flies, respectively, than did light traps placed outside the tents. The implications of these findings to Leishmania transmission in the vicinity of Tallil Air Base are discussed.

A comparison between subjective outcome score and moderate radial shortening following a fractured distal radius in patients of mean age 69 years.

Radial shortening has been associated with a poor functional outcome following a fractured distal radius. This paper reports the results of evaluation by the patient rated wrist evaluation (PRWE) score of 60 patients (mean age 69) who underwent closed reduction and K-wire fixation of distal radial fractures. In this patient group, no association was found between moderate radial shortening, either at injury or fracture union, and this subjective outcome score. A significant association was found between the assessment of these fractures by the Frykman classification and the PRWE score (P=0.01).

Impact of phlebotomine sand flies on U.S. Military operations at Tallil Air Base, Iraq: 1. background, military situation, and development of a "Leishmaniasis Control Program".

One of the most significant modern day efforts to prevent and control an arthropod-borne disease during a military deployment occurred when a team of U.S. military entomologists led efforts to characterize, prevent, and control leishmaniasis at Tallil Air Base (TAB), Iraq, during Operation Iraqi Freedom. Soon after arriving at TAB on 22 March 2003, military entomologists determined that 1) high numbers of sand flies were present at TAB, 2) individual soldiers were receiving many sand fly bites in a single night, and 3) Leishmania parasites were present in 1.5% of the female sand flies as determined using a real-time (fluorogenic) Leishmania-generic polymerase chain reaction assay. The rapid determination that leishmaniasis was a specific threat in this area allowed for the establishment of a comprehensive Leishmaniasis Control Program (LCP) over 5 mo before the first case of leishmaniasis was confirmed in a U.S. soldier deployed to Iraq. The LCP had four components: 1) risk assessment, 2) enhancement of use of personal protective measures by all personnel at TAB, 3) vector and reservoir control, and 4) education of military personnel about sand flies and leishmaniasis. The establishment of the LCP at TAB before the onset of any human disease conclusively demonstrated that entomologists can play a critical role during military deployments.

A prospective cross-sectional study of BK virus infection in non-renal solid organ transplant recipients with chronic renal dysfunction.

BACKGROUND: Polyomavirus (primarily BK virus [BKV]) infection is an important cause of chronic renal dysfunction in renal transplant recipients, but its possible contribution to chronic renal dysfunction in non-renal solid organ transplant (NRSOT) recipients has not been fully explored. METHODS: We performed a prospective, cross-sectional study of consecutive NRSOT recipients with unexplained chronic renal dysfunction of at least a 3 months duration. Medical records were reviewed, and polymerase chain reaction was used to amplify BKV-specific sequences from serum and urine samples. The potential associations between various demographic and transplant variables and BKV infection were assessed. RESULTS: Thirty-four consecutive NRSOT recipients (23 lung, 8 liver, 2 heart, 1 heart-lung) with chronic renal dysfunction were enrolled at a median of 3.5 years (range 0.3-12.5 years) post transplantation. Five of the 34 (15%) patients had BKV viruria (range 1040-1.8 x 10(6) copies/mL), but none had BKV viremia. BK viruria was associated with mycophenolate mofetil use (5 of 19 [26%] vs. 0 of 15, P = 0.03) and a history of cytomegalovirus disease (3 of 4 [75%] vs. 2 of 30 [7%], P < 0.01). However, the mean estimated creatinine clearance was similar in patients with or without BKV viruria (49 vs. 47 mL/min). CONCLUSIONS: BKV viruria was present in a proportion of NRSOT patients with otherwise unexplained chronic renal dysfunction. The possibility that BKV infection might contribute to chronic renal dysfunction in this setting warrants further investigation.