High-throughput fluorescence-activated cell sorting for lipid hyperaccumulating Chlamydomonas reinhardtii mutants.

The genetically tractable microalga Chlamydomonas reinhardtii has many advantages as a model for renewable bioproducts and/or biofuels production. However, one limitation of C. reinhardtii is its relatively low-lipid content compared with some other algal species. To overcome this limitation, we combined ethane methyl sulfonate mutagenesis with fluorescence-activated cell sorting (FACS) of cells stained with the lipophilic stain Nile Red to isolate lipid hyperaccumulating mutants of C. reinhardtii. By manipulating the FACS gates, we sorted mutagenized cells with extremely high Nile Red fluorescence signals that were rarely detected in nonmutagenized populations. This strategy successfully isolated several putative lipid hyperaccumulating mutants exhibiting 23% to 58% (dry weight basis) higher fatty acid contents than their progenitor strains. Significantly, for most mutants, nitrogen starvation was not required to attain high-lipid content nor was there a requirement for a deficiency in starch accumulation. Microscopy of Nile Red stained cells revealed that some mutants exhibit an increase in the number of lipid bodies, which correlated with TLC analysis of triacyglycerol content. Increased lipid content could also arise through increased biomass production. Collectively, our findings highlight the ability to enhance intracellular lipid accumulation in algae using random mutagenesis in conjunction with a robust FACS and lipid yield verification regime. Our lipid hyperaccumulating mutants could serve as a genetic resource for stacking additional desirable traits to further increase lipid production and for identifying genes contributing to lipid hyperaccumulation, without lengthy lipid-induction periods.

Conceptualising and challenging child neglect in humanitarian action: Protecting displaced children in Jordan and Palestine.

BACKGROUND: Humanitarian organisations commonly identify neglect as a specific form of harm from which children should be protected. However, lack of debate about the aetiology of child neglect has left intact a tendency to assume that it is due to a failure of caregivers. Obscured by this assumption are the role of the humanitarian system in supporting or, indeed, undermining the efforts of primary caregivers. OBJECTIVE: To bring together insights from the literature on child neglect in humanitarian settings with findings from empirical research in the Middle East. PARTICIPANTS AND SETTING: Fieldwork involved 38 'peer researchers' from five refugee communities: Sudanese, Somali, Iraqi, Syrian (in Jordan) and Palestinian (in Gaza). These researchers undertook enquiry with a total of around 300 people across their respective communities. METHODS: RESULTS: Fieldwork revealed neglect in three distinct areas: educational participation, access to healthcare, and physical safety. This neglect can be related to the humanitarian system, (including humanitarian agencies, host government, donors, etc.), that is both directly neglectful and undermining of caregivers' efforts. CONCLUSION: Caregivers in our study illustrated the impossibility of exercising constant vigilance over children within conditions of extreme social and economic marginalisation. Thoroughgoing debate about child neglect is needed to address this situation and ensure that caregivers receive adequate support to meet their children's needs. Such support should be offered in a manner that upholds the dignity of displaced people - adults and children alike.

Successful treatment of non-Hodgkin lymphoma associated immune thrombocytopenia with involved field radiotherapy.

Immune thrombocytopenia complicates the course and impacts the outcome of non-Hodgkin lymphoma (NHL-ITP, non-Hodgkin lymphoma-immune thrombocytopenic purpura). The response to corticosteroids and/or intravenous immune globulins is usually short lasting, but NHL-ITP usually responds to anti-lymphoma chemotherapy. It is not clear if this success is due to the elimination of the lymphomatous tissue or to the immunosuppressor/immunomodulator effect of chemotherapy. Myelosuppressive anti-lymphoma chemotherapy carries the risk of severe thrombocytopenia that may not respond adequately to platelet transfusion support. We report on a patient with recurrent diffuse large B-cell lymphoma that coincided with immune thrombocytopenia. Both diseases completely responded to involved field radiation therapy. This supports the hypothesis that at least in some cases of NHL-ITP, the lymphomatous clone secretes the anti-platelet antibodies. This supports the therapeutic decision making for these patients.

Mandated to fail? Humanitarian agencies and the protection of Palestinian children.

This paper considers the efforts of United Nations and international agencies to address the threats to Palestinian children arising from Israeli occupation. It contains an account of the reasons why agencies have failed, over many years, to prevent systematic violations by the Israeli authorities and settlers. The discussion is organised around two inter-related domains: institutional and political. The paper argues that, in the occupied Palestinian territory (oPt), limitations to the ways in which child protection has been conceptualised and pursued in practice are abundantly evident. Nevertheless, political pressure by Western donor governments serves to constrain an approach to child protection that is more preventative in nature, that addresses more explicitly Israeli violations of international law, and that reflects the experience and aspirations of Palestinian children themselves. Ultimately, therefore, the failure to protect Palestinian children must be seen not only as a result of humanitarian miscalculation but also as a consequence of political strategy.

The Child as Vulnerable Victim: Humanitarianism Constructs Its Object.

Over the last one hundred years, humanitarian agencies have considered children primarily through the lens of vulnerability. Advocacy for attention to children's agency and for their participation has burgeoned since the 1980s without shifting the powerful hold that assumptions of vulnerability have had over the policy and practices of humanitarians. This article seeks to denaturalise the conceptualisation of children in contexts of emergency as primarily vulnerable (would-be) victims, placing it in historical and geopolitical contexts. It offers a critical analysis of both conventional humanitarian thinking about vulnerability per se and the reasons for its continued invocation in settings of displacement and political violence. Drawing upon examples from the Mau Mau rebellion against British colonial rule in 1950s Kenya, and current humanitarian response to the situation of Palestinian children living under Israeli occupation, this article relates the continued dominance of the vulnerability paradigm to the pursuit of self-interest by elites and the survival strategies of humanitarian agencies. It pays particular attention to the uses to which mental health thinking and programming is put in what may be called the 'politics of pathologisation'.

Safety and efficacy of pembrolizumab for advanced nonsmall cell lung cancer: before and during the COVID-19 pandemic.

PURPOSE: The COVID-19 pandemic changed diagnostic and treatment pathways in oncology. We compared the safety and efficacy of pembrolizumab amongst advanced nonsmall cell lung cancer (NSCLC) patients with a PD-L1 tumor proportion score (TPS) ≥ 50% before and during the pandemic. METHODS: Advanced NSCLC patients initiating pembrolizumab between June 2015 and December 2019 ("pre-pandemic cohort") and between March 2020 and March 2021 ("pandemic cohort") at BC Cancer were identified retrospectively. Multivariable logistic regression evaluated risk factors for immune-related adverse events (irAE) ≥ grade 3 at the 6 week, 3 month, and 6 month landmarks. Cox regression models of overall survival (OS) were constructed. RESULTS: The study population comprised 417 patients in the pre-pandemic cohort and 111 patients in the pandemic cohort. Between March and May 2020, 48% fewer advanced NSCLC cases with PD-L1 TPS ≥ 50% were diagnosed compared to similar intervals in 2018-2019. Telemedicine assessment [new patient consultations (p < 0.001) and follow-up (p < 0.001)] and extended interval pembrolizumab dosing (p < 0.001) were more common in the pandemic cohort. Patients initiating pembrolizumab after February 2020 (vs. before January 2020) experienced similar odds of developing severe irAE. 2/111 (1.8%) patients receiving pembrolizumab during the pandemic tested positive for COVID-19. On multivariable analysis, no association between pembrolizumab treatment period (before vs. during the COVID-19 pandemic) and OS was observed (p = 0.18). CONCLUSION: Significant changes in healthcare delivery in response to the pandemic did not result in increased high grade toxicity or lower survival outcomes in patients with advanced NSCLC treated with pembrolizumab.

First-line osimertinib for patients with EGFR-mutated advanced non-small cell lung cancer: efficacy and safety during the COVID-19 pandemic.

Background: The FLAURA trial demonstrated improved overall survival (OS) with first-line osimertinib for patients with epidermal growth factor receptor (EGFR)-mutated advanced non-small cell lung cancer (NSCLC). We studied the efficacy and safety of osimertinib in a cohort treated during the coronavirus disease 2019 (COVID-19) pandemic. Methods: Patients diagnosed with EGFR-mutated advanced NSCLC between 11 March 2020 to 31 December 2021 who received first-line osimertinib in British Columbia, Canada were identified retrospectively. Kaplan-Meier curves of OS and progression-free survival (PFS) from the start of osimertinib were plotted. The associations of baseline characteristics with PFS, and development of pneumonitis or dose reductions due to toxicity with OS were evaluated with hazard ratios estimated using univariable and multivariable Cox models. Results: The cohort comprised 231 individuals. 58.7% of patients with de novo advanced NSCLC were initially diagnosed after presentation to the Emergency Room. At osimertinib initiation, 31.6% were aged ≥75 years and 45.5% had an Eastern Cooperative Oncology Group performance status (ECOG PS) ≥2. Median PFS and OS were 18.0 months [95% confidence interval (CI): 16.1-26.2] and 25.4 months (95% CI: 20.3-not reached), respectively. On multivariable analysis, age ≥75 years (vs. <75), ECOG PS 2/3 (vs. 0/1), ECOG PS 4 (vs. 0/1), current smokers (vs. never smokers), programmed death ligand 1 (PD-L1) expression ≥50% (vs. <1%), and L858R mutation (vs. exon 19 deletion) were associated with shorter PFS. Among 110 patients who progressed, 33.6% received subsequent therapy. A proportion of 16.5% of the cohort developed grade ≥3 adverse events. Pneumonitis from osimertinib (3.9% incidence) was weakly associated with shorter OS (hazard ratio: 2.59, 95% CI: 0.94-7.12, P=0.066); dose reductions were not associated with worse OS. 10.8% of patients developed COVID-19. Conclusions: In a cohort receiving first-line osimertinib during the COVID-19 pandemic, ECOG PS ≥2 was observed in nearly half of patients at treatment initiation contributing to a median OS shorter than in FLAURA. The incidence of severe adverse events was low and dose reduction for drug toxicity did not impact OS. Identifying and reducing barriers to the diagnosis of NSCLC during the COVID-19 pandemic are required.

Sexually transmitted penile amoebiasis in Iran: a case series.

OBJECTIVES: Four cases of penile amoebiasis (PA) presenting as genital ulceration seen among men who practiced unprotected insertive anal intercourse in Tehran are described. METHODS: PA was confirmed by observation of motile trophozoites of Entamoeba histolytica from lesions examined by wet mount microscopy. RESULTS: Ulcers were solitary, painful, irregular, discharging and increasing in size. Three heterosexuals and one bisexual had practised insertive anal intercourse in the 2 weeks before diagnosis. Bilateral inguinal lymphadenitis occurred in one case. Direct examination of lesions was positive for the presence of amoebic trophozoites. Complete resolution occurred after treatment with oral metronidazole 800 mg three times daily for 7-10 days. CONCLUSIONS: Clinicians need to be aware of cutaneous amoebiasis in sexually active men who practice unprotected insertive anal sex where intestinal amoebiasis is endemic. Wet mount microscopy is a rapid and useful diagnostic test.

Locoregional Treatments for Metastatic Gastrointestinal Stromal Tumor in British Columbia: A Retrospective Cohort Study from January 2008 to December 2017.

INTRODUCTION: The role of surgery and non-surgical locoregional treatments (LRT) such as radiation therapy (RT) and local ablation techniques in patients with metastatic gastrointestinal stromal tumor (GIST) is unclear. This study examines LRT practice patterns in metastatic GIST and their clinical outcomes in British Columbia (BC). METHODS: Patients diagnosed with either recurrent or de novo metastatic GIST from January 2008 to December 2017 were identified. Clinical characteristics and outcomes were analyzed in patients who underwent LRT, including surgical resection of the primary tumor or metastectomy, RT, or other local ablative procedures. RESULTS: 127 patients were identified: 52 (41%) had de novo metastasis and 75 (59%) had recurrent metastasis. Median age was 67 (23-90 years), 58.2% were male, primary site was 33.1% stomach, 40.2% small intestine, 11% rectum/pelvis, and 15.7% others. 37 (29.1%) of patients received palliative surgery, the majority of which had either primary tumor removal only (43.3%) or both primary tumor removal and metastectomy (35.1%). A minority of patients underwent metastectomy only (21.6%). A total of 12 (9.5%) patients received palliative RT to metastatic sites only (58.3%) or primary tumors only (41.7%), mostly for symptomatic control (n = 9). A few patients (n = 3) received local ablation for liver metastatic deposits with 1 patient receiving microwave ablation (MWA) and 2 receiving radiofrequency ablation (RFA). Most patients (n = 120, 94.5%) received some type of systemic treatment. It is notable that prolonged progression free survival (PFS) was observed for the majority of patients who underwent surgery in the metastatic setting with a median PFS of 20.5 (95% confidence interval (CI): 14.29-40.74) months. In addition, significantly higher median overall survival (mOS) was observed in patients who underwent surgery (97.15 months; 95% CI: 77.7-not reached) and LRT (78.98 months; 95% CI: 65.58-not reached) versus no surgery (45.37 months; 95% CI: 38.7-64.69) and no LRT (45.27 months; 95% CI: 33.25-58.66). Almost all patients (8 out of 9) achieved symptomatic improvement after palliative RT. All 3 patients achieved partial response and 2 out of 3 patients had relatively durable responses of 1 year or more after local ablation. DISCUSSION: This study is among the first to systematically examine the use of various LRT in metastatic GIST management. Integration of LRT with systemic treatments may potentially provide promising durable response and prolonged survival for highly selected metastatic GIST patients with low volume disease, limited progression and otherwise well controlled on systemic treatments. These observations, consistent with others, add to the growing evidence that supports the judicious use of LRT in combination with systemic treatments to further optimize the care of metastatic GIST patients.

Utilization of Mutational Analysis (MA) in Gastrointestinal Stromal Tumor (GIST) Management in British Columbia (BC) Between January 2008 to December 2017: a Retrospective Population-Based Study.

PURPOSE: To examine oncologists' practice pattern of ordering MA in localized and metastatic GISTs in British Columbia (BC). METHODS: Patients diagnosed with GIST from January 2008 to December 2017 in BC were identified. Chart review was performed to determine clinical characteristics and the use of MA as part of their oncologic care. RESULTS: The cohort included 411 patients: median age 64 (18-94 years), 49.1% male, primary site included stomach (53%), small intestine (32%), and others (15%). Sixty-nine percent had localized disease, while 13% presented with de novo metastatic disease and 18% had recurrent metastatic disease. MA was ordered in 41% of the patients overall, 28% in localized, and 70% in metastatic settings (63% in de novo metastasis and 78% in recurrent metastasis). Among patients with localized disease, higher MA use rates were observed among those undergoing neoadjuvant/adjuvant treatment (45%) compared to those not receiving systemic therapy (18%). While MA use rates in localized GIST did not change over time (28.5% before 2015 and 28% after 2015), MA use in metastatic disease increased from 54% before 2015 to 79% after 2015. Among all MA ordered for metastatic disease, 82.4% were ordered at the time of de novo metastatic diagnosis, and 77.4% were ordered either at the time of recurrent metastatic diagnosis or earlier when the disease was localized. CONCLUSION: MA use has remained stable for localized disease but has increased after 2015 in the metastatic setting which may be due to evolving sequencing technology, expansion of metastatic treatment options, and enhanced awareness of MA.

Transformation of follicular lymphoma to diffuse large B-cell lymphoma may occur by divergent evolution from a common progenitor cell or by direct evolution from the follicular lymphoma clone.

To investigate the cell of origin linking follicular (FL) and transformed (t-FL) lymphomas, we analyzed the somatic hypermutation (SHM) pattern of the variable region of the immunoglobulin heavy gene (IgH-VH) in 18 sequential FL/t-FL samples and a father (donor) and son (recipient), who developed FL and t-FL, after transplantation. Genealogic trees showed a pattern compatible with a common progenitor cell (CPC) origin in 13 cases. The identification of the t-FL clonotype in the previous FL sample and of the putative CPC sequence in both the FL/t-FL biopsies showed that the intraclonal diversity of FL and t-FL germinal centers (GCs) is more intricate than previously described, and all 3 clonotypes (CPC, FL, t-FL) may occur simultaneously within the same lymph node. On the basis of the father/son model, this CPC must be long-lived, providing a possible explanation for the incurable nature of this disease.

Rituximab for management of refractory pregnancy-associated immune thrombocytopenic purpura.

BACKGROUND: Rituximab is a novel therapy for immune thrombocytopenic purpura (ITP); however, information about its safety in pregnancy is limited. This case illustrates the successful use of rituximab to treat pregnancy-associated ITP. CASE: A 34-year-old woman presented with severe ITP at 23 weeks' gestation. Standard treatment with corticosteroids, intravenous immune globulin, and splenectomy failed to raise the platelet count. Due to ongoing bleeding, rituximab was given in the 26th week of pregnancy. The platelet count rose to over 100 × 10(9)/L after four weeks. The neonatal B-lymphocyte count normalized at four months after delivery. There were no neonatal complications of rituximab therapy. CONCLUSION: Rituximab may be safe for use in treating pregnancy-associated ITP. This case highlights the need to investigate further the safety and efficacy of rituximab in pregnancy.

On coffee talk and break-room chatter: perceptions of women who gossip in the workplace.

The present study examined perceptions of female gossipers in the workplace. Male and female participants (N=129) were asked to think of a woman who either frequently or rarely contributed negative information about other people during conversation. Participants then completed ratings on the target using the six dimensions of the FIRO-B. As predicted, high gossipers were perceived as having a greater need to exert control of others, but less need for others to control them, than low gossipers. Higher gossipers were also perceived as less emotionally warm than low gossipers. The implications of these findings for gossip research are presented.

Treatment and outcomes in adult patients with primary cardiac sarcoma: the British Columbia Cancer Agency experience.

BACKGROUND: To evaluate treatment and survival in a cohort of patients referred to a Canadian institution with newly diagnosed primary cardiac sarcoma. METHODS: Between 1990 and 2006, 16 patients were referred to the British Columbia Cancer Agency with pathologically confirmed sarcoma of cardiac origin. Retrospective chart review was performed to document patient, tumor, and treatment characteristics. Disease-free survival and overall survival (OS) were calculated by Kaplan-Meier methods and compared in different subgroups by log rank statistics. RESULTS: The cohort comprised 10 female and 6 male patients. The mean age was 51 years (range, 27-81 years). The most common histologic subtype was angiosarcoma. Surgical resection, alone or in combination with chemotherapy or radiotherapy, was undertaken in 10 of 12 patients with localized and 3 of 4 patients with metastatic disease. At a median follow-up of 8 months, all patients had died of disease. In the entire cohort, mean disease-free survival and OS were 6 months and 14 months, respectively. Patients with localized disease had significantly longer survival compared to metastatic disease (mean OS 18 months vs. 2 months, P = 0.001). Patients treated with complete resection had improved OS compared to incompletely resected disease (25 months vs. 6 months, P = 0.042). Age, sex, tumor grade, location, and subtype were not associated with statistically significant survival differences. CONCLUSIONS: Patients with nonmetastatic cardiac sarcoma amenable to complete resection experienced improved survival. However, the high overall rates of disease progression and mortality highlight the need for more effective local and systemic treatments that may be used in conjunction with surgery to improve patient outcomes.

Altering the Substrate Specificity of Acetyl-CoA Synthetase by Rational Mutagenesis of the Carboxylate Binding Pocket.

Acetyl-CoA synthetase (ACS) is a member of a large superfamily of enzymes that display diverse substrate specificities, with a common mechanism of catalyzing the formation of a thioester bond between Coenzyme A and a carboxylic acid, while hydrolyzing ATP to AMP and pyrophosphate. As an activated form of acetate, acetyl-CoA is a key metabolic intermediate that links many metabolic processes, including the TCA cycle, amino acid metabolism, fatty acid metabolism and biosynthetic processes that generate many polyketides and some terpenes. We explored the structural basis of the specificity of ACS for only activating acetate, whereas other members of this superfamily utilize a broad range of other carboxylate substrates. By computationally modeling the structure of the Arabidopsis ACS and the Pseudomonas chlororaphis isobutyryl-CoA synthetase using the experimentally determined tertiary structures of homologous ACS enzymes as templates, we identified residues that potentially comprise the carboxylate binding pocket. These predictions were systematically tested by mutagenesis of four specific residues. The resulting rationally redesigned carboxylate binding pocket modified the size and chemo-physical properties of the carboxylate binding pocket. This redesign successfully switched a highly specific enzyme from using only acetate, to be equally specific for using longer linear (up to hexanoate) or branched chain (methylvalerate) carboxylate substrates. The significance of this achievement is that it sets a precedent for understanding the structure-function relationship of an enzyme without the need for an experimentally determined tertiary structure of that target enzyme, and rationally generates new biocatalysts for metabolic engineering of a broad range of metabolic processes.

Therapeutic Implication of Genomic Landscape of Adult Metastatic Sarcoma.

PURPOSE: This study investigated therapeutic potential of integrated genome and transcriptome profiling of metastatic sarcoma, a rare but extremely heterogeneous group of aggressive mesenchymal malignancies with few systemic therapeutic options. METHODS: Forty-three adult patients with advanced or metastatic non-GI stromal tumor sarcomas of various histology subtypes who were enrolled in the Personalized OncoGenomics program at BC Cancer were included in this study. Fresh tumor tissues along with blood samples underwent whole-genome and transcriptome sequencing. RESULTS: The most frequent genomic alterations in this cohort are large-scale structural variation and somatic copy number variation. Outlier RNA expression as well as somatic copy number variations, structural variations, and small mutations together suggest the presence of one or more potential therapeutic targets in the majority of patients in our cohort. Point mutations or deletions in known targetable cancer genes are rare; for example, tuberous sclerosis complex 2 provides a rationale for targeting the mammalian target of rapamycin pathway, resulting in a few patients with exceptional clinical benefit from everolimus. In addition, we observed recurrent 17p11-12 amplifications, which seem to be a sarcoma-specific event. This may suggest that this region harbors an oncogene(s) that is significant for sarcoma tumorigenesis. Furthermore, some sarcoma tumors carrying a distinct mutational signature suggestive of homologous recombination deficiency seem to demonstrate sensitivity to double-strand DNA-damaging agents. CONCLUSION: Integrated large-scale genomic analysis may provide insights into potential therapeutic targets as well as novel biologic features of metastatic sarcomas that could fuel future experimental and clinical research and help design biomarker-driven basket clinical trials for novel therapeutic strategies.

Storage of partly used closed-circuit rebreather carbon dioxide absorbent canisters.

INTRODUCTION: Diving rebreathers use "scrubber" canisters containing soda lime to remove carbon dioxide (CO2) from the expired gas. Soda lime has a finite ability to absorb CO2. We undertook an experiment to determine whether the manner of storage of a partly used scrubber affected subsequent CO2 absorption. METHODS: An Evolution Plus™ rebreather was mechanically ventilated in a benchtop circuit. Respiratory minute volume was 45 L·min-1 and CO2 was introduced to the expiratory limb at 2 L·min-1. The scrubber canister was packed with 2.64 kg of Sofnolime 797™. Scrubbers were run in this circuit for 90 minutes then removed from the rebreather and stored in packed form under one of three conditions: "open" (unsealed) for 28 days (n = 4); vacuum "sealed" in an airtight plastic bag for 28 days (n = 5); or open overnight (n = 5). Following storage the scrubber canisters were placed back in the rebreather and run as above until the PCO2 in the inspired gas exceeded 1 kPa. The total duration of operation to reach this end-point in each storage condition was compared. RESULTS: The mean run times to reach an inspired CO2 of 1 kPa were 188, 241, and 239 minutes in the open-28-day, the sealed-28-day and the open-overnight storage conditions, respectively. CONCLUSION: Rebreather divers should consider placing partially used soda lime scrubber canisters in vacuum-sealed plastic bags if storing them for longer periods than overnight. If a partially used scrubber canister is to be used again the next day then the storage modality is unlikely to influence scrubber efficacy.

The duration of two carbon dioxide absorbents in a closed-circuit rebreather diving system.

INTRODUCTION: Diving rebreathers use canisters containing sodalime preparations to remove carbon dioxide (CO2) from the expired gas. These preparations have a limited absorptive capacity and therefore may limit dive duration. The Inspiration™ rebreather is designed for use with Sofnolime 797™ but some divers use Spherasorb™ as an alternative. There are no published data comparing the CO2-absorbing efficacy of these sodalime preparations in an Inspiration rebreather. METHODS: An Inspiration rebreather was operated in a benchtop circuit under conditions simulating work at 6 metabolic equivalents (MET). Ventilation was maintained at 45 L·min⁻¹ (tidal volume 1·5 L; respiratory rate 30 min⁻¹) with CO2 introduced to the expiratory limb at 2·L·min⁻¹. The PiCO2 was continuously monitored in the inspiratory limb. The rebreather canister was packed to full volume with either Sofnolime or Spherasorb and 10 trials were conducted (five using each absorbent), in which the circuit was continuously run until the PiCO2 reached 1 kPa ('breakthrough'). Peak inspiratory and expiratory pressures during tidal ventilation of the circuit were also recorded. RESULTS: The mean operating duration to CO2 breakthrough was 138 ± 4 (SD) minutes for 2.38·kg Spherasorb and 202 ± minutes for 2.64·kg Sofnolime (P < 0.0001). The difference between peak inspiratory and expiratory pressures was 10% less during use of Spherasorb, suggesting lower work of breathing. CONCLUSIONS: Under conditions simulating work at 6 MET during use of an Inspiration rebreather a canister packed with Spherasorb reached CO2 breakthrough 32% earlier with 10% less mass than Sofnolime packed to similar volume. Divers cannot alternate between these two preparations and expect the same endurance.

Comparative evaluation of matrix-assisted laser desorption ionisation-time of flight mass spectrometry and conventional phenotypic-based methods for identification of clinically important yeasts in a UK-based medical microbiology laboratory.

AIMS: Performance of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) was compared in a side-by side-analysis with conventional phenotypic methods currently in use in our laboratory for identification of yeasts in a routine diagnostic setting. METHODS: A diverse collection of 200 clinically important yeasts (19 species, five genera) were identified by both methods using standard protocols. Discordant or unreliable identifications were resolved by sequencing of the internal transcribed spacer region of the rRNA gene. RESULTS: MALDI-TOF and conventional methods were in agreement for 182 isolates (91%) with correct identification to species level. Eighteen discordant results (9%) were due to rarely encountered species, hence the difficulty in their identification using traditional phenotypic methods. CONCLUSIONS: MALDI-TOF MS enabled rapid, reliable and accurate identification of clinically important yeasts in a routine diagnostic microbiology laboratory. Isolates with rare, unusual or low probability identifications should be confirmed using robust molecular methods.