In-hospital and 6-month outcomes in patients with COVID-19 supported with extracorporeal membrane oxygenation (EuroECMO-COVID): a multicentre, prospective observational study

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has been widely used in patients with COVID-19, but uncertainty remains about the determinants of in-hospital mortality and data on post-discharge outcomes are scarce. The aims of this study were to investigate the variables associated with in-hospital outcomes in patients who received ECMO during the first wave of COVID-19 and to describe the status of patients 6 months after ECMO initiation.

METHODS

EuroECMO-COVID is a prospective, multicentre, observational study developed by the European Extracorporeal Life Support Organization. This study was based on data from patients aged 16 years or older who received ECMO support for refractory COVID-19 during the first wave of the pandemic-from March 1 to Sept 13, 2020-at 133 centres in 21 countries. In-hospital mortality and mortality 6 months after ECMO initiation were the primary outcomes. Mixed-Cox proportional hazards models were used to investigate associations between patient and management-related variables (eg, patient demographics, comorbidities, pre-ECMO status, and ECMO characteristics and complications) and in-hospital deaths. Survival status at 6 months was established through patient contact or institutional charts review. This study is registered with ClinicalTrials.gov, NCT04366921, and is ongoing.

FINDINGS

Between March 1 and Sept 13, 2020, 1215 patients (942 [78%] men and 267 [22%] women; median age 53 years [IQR 46-60]) were included in the study. Median ECMO duration was 15 days (IQR 8-27). 602 (50%) of 1215 patients died in hospital, and 852 (74%) patients had at least one complication. Multiorgan failure was the leading cause of death (192 [36%] of 528 patients who died with available data). In mixed-Cox analyses, age of 60 years or older, use of inotropes and vasopressors before ECMO initiation, chronic renal failure, and time from intubation to ECMO initiation of 4 days or more were associated with higher in-hospital mortality. 613 patients did not die in hospital, and 547 (95%) of 577 patients for whom data were available were alive at 6 months. 102 (24%) of 431 patients had returned to full-time work at 6 months, and 57 (13%) of 428 patients had returned to part-time work. At 6 months, respiratory rehabilitation was required in 88 (17%) of 522 patients with available data, and the most common residual symptoms included dyspnoea (185 [35%] of 523 patients) and cardiac (52 [10%] of 514 patients) or neurocognitive (66 [13%] of 512 patients) symptoms.

INTERPRETATION

Patient's age, timing of cannulation (<4 days vs ≥4 days from intubation), and use of inotropes and vasopressors are essential factors to consider when analysing the outcomes of patients receiving ECMO for COVID-19. Despite post-discharge survival being favourable, persisting long-term symptoms suggest that dedicated post-ECMO follow-up programmes are required.

FUNDING

None.

Outcomes of Extracorporeal Membrane Oxygenation (ECMO) for COVID-19 Patients: A Multi-Institutional Analysis

BACKGROUND

In March 2020, COVID-19 was announced as a global pandemic. The first COVID-19 patient was connected to an ECMO device in Israel during that time. Since then, over 200 patients have required ECMO support due to COVID-19 infection. The present study is a multi-institutional analysis of all COVID-19 patients requiring veno-venous (VV) ECMO in Israel. The aim was to characterize and compare the survivors and deceased patients as well as establish risk factors for mortality.

METHODS

This retrospective multi-institutional study was conducted from March 2020 to March 2021 in eleven of twelve ECMO centers operating in Israel. All COVID-19 patients on VV ECMO support were included in the cohort. The patients were analyzed based on their comorbidities, procedural data, adverse event on ECMO, and outcomes. Univariate and multivariate analyses were used to compare the deceased and the surviving patients.

RESULTS

The study included 197 patients, of which 150 (76%) were males, and the mean age was 50.7 ± 12 years. Overall mortality was 106 (54%). Compared with the deceased subjects, survivors were significantly younger (48 ± 11 vs. 53 ± 12 years), suffered less from ischemic heart disease (IHD) (3% vs. 12%), and were ventilated for a significantly shorter period (≤4 days) prior to cannulation (77% vs. 63%). Patients in the deceased group experienced more kidney failure and sepsis. Rates of other complications were comparable between groups.

CONCLUSIONS

Based on this study, we conclude that early cannulation (≤4 days) of younger patients (≤55 years) may improve overall survival and that a history of IHD might indicate a reduced prognosis.

Complementary and integrative medicine intervention in front-line COVID-19 clinicians

OBJECTIVE

To assess the impact of a multidisciplinary complementary and integrative medicine (CIM) intervention on physical and emotional concerns among front-line COVID-19 healthcare providers (HCPs).

METHODS

A multimodality CIM treatment intervention was provided by integrative practitioners to HCPs in three isolated COVID-19 departments. HCPs' two main concerns were scored (from 0 to 6) before and following the CIM intervention using the Measure Yourself Concerns and Wellbeing questionnaire. Postintervention narratives identified reflective narratives specifying emotional and/or spiritual keywords.

RESULTS

Of 181 HCPs undergoing at least one CIM treatment, 119 (65.7%) completed post-treatment questionnaires. While HCPs listing baseline emotional-related concerns benefited from the CIM intervention, those who did not express emotional or spiritual concerns improved even more significantly following the first session, for both leading concerns (p=0.038) and emotional-related concerns (p=0.023). Nevertheless, it was shown that following subsequent treatments HCPs who expressed emotional and spiritual concerns improved more significantly than those who did not for emotional-related concerns (p=0.017).

CONCLUSIONS

A CIM intervention for front-line HCPs working in isolated COVID-19 departments can significantly impact emotional-related concerns, more so after the first treatment and among HCPs not using emotional-spiritual keywords in post-treatment narratives. Referral of HCPs to CIM programmes for improved well-being should avoid referral bias to those not expressing emotional/spiritual concerns.

Sensing the lightness: a narrative analysis of an integrative medicine program for healthcare providers in the COVID-19 department

Objectives

The research addressing physical and emotional exhaustion among healthcare providers (HCPs) in COVID-19 departments is limited. We examined the impact of integrative medicine (IM) intervention for HCPs working in isolated COVID-19 in-patient departments, addressing concerns and well-being.

Methods

HCPs working in 3 isolated COVID-19 in-patient departments underwent 40-min IM treatment sessions (including acupuncture, manual movement, and/or mind–body modalities) provided by integrative oncology practitioners. The MYCAW (Measure Yourself Concerns and Well-being) questionnaire examined HCP concerns and free-text narratives following IM treatments. Data were qualitatively analyzed using ATLAS.Ti software for systematic coding.

Results

A total of 181 HCPs underwent 305 IM treatments. Narrative themes focused on physical symptoms (primarily pain and fatigue) and emotional concerns, including perceived communication barriers with patients, and reflections on well-being and insights following IM treatments. HCPs reported feeling a sense of “relief” which was likely related to the 3 main effects of the IM intervention: a sense of “being cared for” and treated; experiencing emotional, sometimes spiritual effects of the treatment; and the feeling of relaxation, combined with the relief of pain. Qualitative analysis identified clusters of emotional and spiritual-related keywords such as “calming,” “release,” “relaxation,” and “disengagement” following the first IM session (119 of 181 narratives, 65.7%).

Conclusions

HCPs working in isolated COVID-19 departments reported improved well-being and the addressing of their concerns following IM treatment sessions provided during their work shift. Further research is needed to explore the impact of IM on HCP burnout and resilience in palliative care settings.

COVID-19: minimising risk to healthcare workers during aerosol-producing respiratory therapy using an innovative constant flow canopy

Noninvasive ventilation (NIV), continuous positive airway pressure (CPAP) and high-flow nasal cannula (HFNC) can be used as the first line of treatment in coronavirus disease 2019 (COVID-19) patients with respiratory failure, postponing and maybe even avoiding the need for intubation and mechanical ventilation [1]. Recent systematic review and meta-analysis demonstrated that HFNC reduces the need for intubation compared with conventional oxygen, with no change in the death risk or length of stay in the intensive care unit [2, 3]. No direct evidence supports the use of NIV, due to a high failure rate [4]. However, when resources become limited, with no option of invasive ventilation, the use of NIV may be justified. The major caveat of using noninvasive respiratory support in the face of the COVID-19 pandemic is the generation of aerosols, composed of small virus-containing particles, which may remain suspended in the air, with increased risk for healthcare workers [5, 6]. The risk of aerosolisation depends on many variables, including duration of use, flow velocity, mask leakage and patient coughing and cooperation.

An innovative constant flow canopy enables noninvasive respiratory support with minimal risk of healthcare worker infectionhttps://bit.ly/3eqgoVZ

Empty SV40 capsids increase survival of septic rats by eliciting numerous host signaling networks that participate in a number of systemic functions

Sepsis is an excessive, dysregulated immune response to infection that activates inflammatory and coagulation cascades, which may lead to tissue injury, multiple organ dysfunction syndrome and death. Millions of individuals die annually of sepsis. To date, the only treatment available is antibiotics, drainage of the infection source when possible, and organ support in intensive care units. Numerous previous attempts to develop therapeutic treatments, directed at discreet targets of the sepsis cascade, could not cope with the complex pathophysiology of sepsis and failed. Here we describe a novel treatment, based on empty capsids of SV40 (nanocapsids - NCs). Studies in a severe rat sepsis model showed that pre-treatment by NCs led to a dramatic increase in survival, from zero to 75%. Transcript analyses (RNAseq) demonstrated that the NC treatment is a paradigm shift. The NCs affect multiple facets of biological functions. The affected genes are modified with time, adjusting to the recovery processes. The NCs effect on normal control rats was negligible. The study shows that the NCs are capable of coping with diseases with intricate pathophysiology. Further studies are needed to determine whether when applied after sepsis onset, the NCs still improve outcome.

WHO Needs High FIO2?

World Health Organization and the United States Center for Disease Control have recently recommended the use of 0.8 FIO₂ in all adult surgical patients undergoing general anaesthesia, to prevent surgical site infections. This recommendation has arisen several discussions: As a matter of fact, there are numerous studies with different results about the effect of FIO₂ on surgical site infection. Moreover, the clinical effects of FIO₂ are not limited to infection control. We asked some prominent authors about their comments regarding the recent recommendations.

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine: Brussels, Belgium. 15-18 March 2016

[This corrects the article DOI: 10.1186/s13054-016-1208-6.].

[Recurrent bilateral anterior uveitis due to Leishmania infantum in a patient with immune deficiency related to HIV infection: a case report and literature review]

We report the case of a 56-year-old patient, presenting with bilateral hypertensive anterior uveitis due to Leishmania infantum, in the setting of immune deficiency related to HIV infection. The etiology of the uveitis was diagnosed following detection of L. infantum DNA on anterior chamber paracentesis. Initially, the patient received an intravitreal injection of liposomal amphotericin B, systemic antiparasitic treatment, topical steroid and ocular hypotensive treatment. Due to unfavourable disease progression in the right eye, we re-evaluated the anti-inflammatory, antiretroviral and antiparasitic medications (beginning meglumine antimoniate): the uveitis in the left eye was thus able to be controlled. We followed the efficacy of treatment with weekly quantification of Leishmania DNA in the aqueous humor. Uveitis secondary to leishmaniasis is rare and serious. Physicians must be aware of this cause of uveitis, particularly in immunodeficient patients. The quantitation of Leishmania DNA in the aqueous humor is an indispensible tool for monitoring the disease.

Loss of IGFBP7 expression and persistent AKT activation contribute to SMARCB1/Snf5-mediated tumorigenesis

SMARCB1 (Snf5/Ini1/Baf47) is a potent tumor suppressor, the loss of which serves as the diagnostic feature in malignant rhabdoid tumors (MRT) and atypical teratoid/rhabdoid tumors (AT/RT), two highly aggressive forms of pediatric neoplasms. SMARCB1 is a core subunit of Swi/Snf chromatin remodeling complexes, and loss of SMARCB1 or other subunits of these complexes has been observed in a variety of tumor types. Here, we restore Smarcb1 expression in cells derived from Smarcb1-deficient tumors, which developed in Smarcb1 heterozygous p53(-/-) mice. We find that while re-introduction of Smarcb1 does not induce growth arrest, it restores sensitivity to programmed cell death and completely abolishes the ability of the tumor cells to grow as xenografts. We describe persistent activation of AKT signaling in Smarcb1-deficient cells, which stems from PI3K (phosphatidylinositol 3'-kinase)-mediated signaling and which contributes to the survival and proliferation of the tumor cells. We further demonstrate that inhibition of AKT is effective in preventing proliferation of Smarcb1-deficient cells in vitro and inhibits the development of xenografted tumors in vivo. Profiling Smarcb1-dependent gene expression, we find genes that require Smarcb1 and Swi/Snf for their expression to be enriched for extracellular matrix and cell adhesion functions. We find that Smarcb1 is required for transcriptional activation of Igfbp7, a member of the insulin-like growth factor-binding proteins family and a tumor suppressor in itself, and show that re-introduction of Igfbp7 alone can hinder tumor development. Our results define a novel mechanism for Smarcb1-mediated tumorigenesis and highlight potential therapeutic targets.

Hypotension during gradual blood loss: waveform variables response and absence of tachycardia

BACKGROUND

Variation in arterial pressure and plethysmographic waveforms has been shown to be predictors of cardiac output response to fluid challenge. The objective of this study was to evaluate the ability of arterial and plethysmographic waveform variables to predict hypotension during blood loss.

METHODS

Patients undergoing autologous haemodilution were studied. After anaesthesia induction, blood was withdrawn in steps of 2% of estimated circulating blood volume (ECBV). Arterial and plethysmographic waveforms were recorded and analysed offline at each step of blood withdrawal.

RESULTS

Thirty-four (29%) out of 118 studied patients tolerated 20% ECBV withdrawal without hypotension. Patients who tolerated 20% ECBV withdrawal were younger than those who did not [mean (sd): 53.8 (11.1) vs 62.7 (10.7); P<0.0001]. Patients with hypertension developed hypotension earlier than healthier patients did. There were no differences at the baseline in arterial and plethysmographic waveform variables between those who did and those who did not tolerate 20% of ECBV withdrawal. All values of variables increased significantly from the baseline after the withdrawal of 4% of ECBV (P<0.005). There were no changes in heart rate (HR), 73 (12) at the baseline and 76 (13) after 20% of ECBV withdrawal (P=0.4).

CONCLUSIONS

Arterial and plethysmographic waveform variables were augmented with increasing blood loss in all patients. Older patients, patients who received anti-hypertensive drugs, or both developed hypotension earlier than others. Baseline values were weak predictors of hypotension during stepwise blood withdrawal. No clinically significant increase in HR was observed, regardless of tolerance of arterial pressure to blood withdrawal.

Hand-assisted laparoscopic surgery for liver tumors

BACKGROUND

The surgical treatment for liver tumors, whether metastatic or hepatic in origin, traditionally used the open approach through large incisions. In recent years the laparoscopic approach became popular but few centers use this method routinely.

OBJECTIVES

To assess the results of our initial experience with liver resection using the laparoscopic approach, in terms of patient safety and oncologic surgical outcome.

METHODS

Between August 2007 and April 2008 we performed 10 liver resections in 9 patients using the hand-assisted laparoscopic surgery technique.

RESULTS

The main indication for surgery was metastatic colorectal carcinoma in seven patients and hepatocellular carcinoma in two. The mean age was 67 +/- 11 years. The tumor was solitary in seven patients. Five patients had neoadjuvant chemotherapy. Altogether, 12 lesions with an average size of 17 +/- 9 mm were resected. The mean operative time was 180 +/- 52 minutes. Average postoperative stay was 6.5 +/- 3.5 days. There was no perioperative mortality. There was one conversion to open surgery due to bleeding from the left hepatic vein. No major perioperative complications were encountered. All resected margins were free of malignancy.

CONCLUSIONS

Liver resection using HALS is safe and feasible and should be considered in selected patients.

[Evolution of third-generation cephalosporin resistance in Enterobacteriaceae from 2000 to 2008 in a Perpignan hospital]

The aim of this work was to evaluate the evolution of Enterobacteriaceae resistance to third generation cephalosporin (3CG) from 2000 to 2008 at Perpignan hospital. Were observed: the percentage of strains isolated from short stay wards, intensive care unit and medium and long-term care facility. The percentage of strains isolated from: urine, suppuration, tracheal aspiration, and blood have been evaluated. The proportion of Escherichia coli (E. coli) strains among the Enterobacteriaceae strains intermediate (I) or resistant (R) to 3GC was also evaluated.The number of Enterobacteriaceae intermediated (I) or resistant (R) to 3GC increased (402 %).The distribution of species I or R to 3GC has changed, decrease of Klebsielle pneumoniae and Enterobacter aeorogenes species, Escherichia.coli and Enterobacter cloacae became dominant in 2008. We noted the change of isolated species distribution, urines represent the main source of multiresistant Enterobacteriaceae (MRE), 72 % of strains. The profile of patients colonised or infected by MRE has changed. Patients mainly infected with hospital acquirred MRE changed to MRE colonised patients carrying the strain into the hospital. The association of fluorinated quinolone resistance and Extended-Spectrum Beta-Lactamase Enterobacteriaceae represented 51 % in 2000, became stable at 73 % from 2002. The association of fluorinated quinolone resistance and high-level Enterobacteriaceae cephalosporinase has increased from 21 % in 2000 to be stable at 50 % since 2006. The mesures to contain the spread of MRE strains remained inefficient because of outpatients circulation, multiresistant E. coli being community species.

The impact of an electronic reminder on the use of alarms after separation from cardiopulmonary bypass

INTRODUCTION

During cardiopulmonary bypass (CPB) monitor alarms are routinely disabled. Failure to reactivate these alarms after CPB may jeopardize patient safety. We have produced an electronic reminder that automatically alerts clinicians to reactivate alarms after CPB and have evaluated the alarm reactivation rate after its implementation.

METHODS

We developed and implemented an algorithm that identifies separation from CPB by the return of pulsatile flow and of mechanical ventilation, and checks alarm status (activated, disabled or silenced). If alarms have not been reactivated after separation from CPB, an electronic reminder appears. Data were collected during three time periods: Stage I (304 patients)--baseline period before implementation of the electronic reminder; Stage II (256 patients)--after implementation; Stage III-(435 patients) after a single educational departmental meeting, at the end of Stage II. Incidence of proper alarm reactivation and the number of electronic reminders per patient were compared among stages.

RESULTS

The rate of alarm reactivation at baseline (Stage I) was 22%, increased to 63% (Stage II), and again to 83% during Stage III (P < 0.001). The spontaneous alarm reactivation rate before the appearance of the electronic reminder on the anesthesia information management system screen increased from 19% at Stage II to 42% at stage III (P < 0.001).

CONCLUSION

Introducing an automatic electronic reminder significantly increased the rate of alarm reactivation after separation from CPB. Real-time computerized decision-support tools can be developed within anesthesia information management system and may be useful for improving safety during anesthesia.

DNA-free recombinant SV40 capsids protect mice from acute renal failure by inducing stress response, survival pathway and apoptotic arrest

Viruses induce signaling and host defense during infection. Employing these natural trigger mechanisms to combat organ or tissue failure is hampered by harmful effects of most viruses. Here we demonstrate that SV40 empty capsids (Virus Like Particles-VLPs), with no DNA, induce host Hsp/c70 and Akt-1 survival pathways, key players in cellular survival mechanisms. We postulated that this signaling might protect against organ damage in vivo. Acute kidney injury (AKI) was chosen as target. AKI is critical, prevalent disorder in humans, caused by nephrotoxic agents, sepsis or ischemia, via apoptosis/necrosis of renal tubular cells, with high morbidity and mortality. Systemic administration of VLPs activated Akt-1 and upregulated Hsp/c70 in vivo. Experiments in mercury-induced AKI mouse model demonstrated that apoptosis, oxidative stress and toxic renal failure were significantly attenuated by pretreatment with capsids prior to the mercury insult. Survival rate increased from 12% to >60%, with wide dose response. This study demonstrates that SV40 VLPs, devoid of DNA, may potentially be used as prophylactic agent for AKI. We anticipate that these finding may be projected to a wide range of organ failure, using empty capsids of SV40 as well as other viruses.

Activation and transposition of endogenous retroviral elements in hypomethylation induced tumors in mice

Genomewide DNA hypomethylation is a consistent finding in human tumors, but the importance of this change for human tumorigenesis remains an open question. We have previously reported that mice carrying a hypomorphic allele for the maintenance DNA methyltransferase (Dnmt1(chip/-)) are hypomethylated and develop thymic lymphomas, demonstrating that genomewide DNA hypomethylation can induce tumors. Hypomethylated cells exhibit inherent chromosomal instability, which is revealed in the lymphomas as a consistent trisomy of chromosome 15. We now report another aspect of the molecular basis for tumor development upon DNA hypomethylation. Seven out of 16 hypomethylation-induced lymphomas were found to contain an intracisternal A particle (IAP) somatic insertion in the middle of the Notch1 genomic locus, leading to generation of an oncogenic form of Notch1 in the tumors. This finding suggests that the molecular basis for hypomethylation-induced tumors in this model involves chromosomal instability events accompanied by activation of endogenous retroviral elements. Our findings validate the proposed role of DNA methylation in suppression of transposable elements in mammalian cells and demonstrate the importance of DNA methylation for normal cell function as well as the potential consequences of spontaneously occurring or chemically induced DNA hypomethylation.

The implementation of an anesthesia information management system

BACKGROUND AND OBJECTIVE

Anaesthesia information management systems, though still not used widely, will inevitably replace handwritten records and may eventually serve as a core for the development of computerized decision support. We investigated staff expectations and the accuracy of data entry in a recently implemented commercially available anaesthesia information management system.

METHODS

A structured questionnaire was administered to the staff before and 1 week and 3 months after implementation in order to assess their opinion. The quality of manual data entry, and of automatic data record was evaluated by looking for missing data and the prevalence of artefacts.

RESULTS

Despite initial fears the users quickly accepted the system. Both automatic and manual data entry were found to be accurate and reliable while the prevalence of artefacts was relatively low.

CONCLUSIONS

A commercially available anaesthesia information management system can be easily implemented and used instead of paper charts.

The effects of intrathecal morphine on patients undergoing minimally invasive direct coronary artery bypass surgery

OBJECTIVE

To evaluate the effects of intrathecal morphine (ITM) on the perioperative use of opiates and the fast-track pathway in patients undergoing minimally invasive direct coronary artery bypass grafting (MIDCAB).

DESIGN

Retrospective cohort study.

SETTINGS

University teaching hospital.

PARTICIPANTS

Twenty-two elective consecutive patients who underwent MIDCAB surgery.

INTERVENTIONS

Eleven patients received an intrathecal injection of morphine, 7 microg/kg (ITM group, n=11), and the control group (n=11) received standard anesthesia care.

MEASUREMENTS AND MAIN RESULTS

The intraoperative dose of fentanyl was 0.55+/-0.2 mg in the ITM group and 1.1+/-0.2 mg in the control group (p<0.0001). Four patients in the ITM group and none in the control group were extubated in the operating room. Extubation time was 3.2+/-4.7 hours in the ITM group and 6.3+/-3.4 hours in the control group (p=0.016). Morphine requirements in 24 hours after surgery were 2.0+/-3.5 mg in the ITM and 16.1+/-4.8 mg in the control group (p<0.0001). There were no differences in ischemic time, intraoperative fluid requirements, postoperative blood loss, and duration of surgical procedure. Hospital length of stay was shorter in the ITM group compared with the control group (3.9+/-1.7 days v 4.9+/-1.4 days, respectively, p=0.047).

CONCLUSIONS

ITM has to be considered in MIDCAB surgery as an effective component of the perioperative analgesia. The safety and effects of ITM in the patients recovery after MIDCAB surgery should be evaluated in further prospective studies.

Lack of association between B19 or V9 erythrovirus infection and ANCA-positive vasculitides: a case-control study

OBJECTIVES

To examine the potential association of human B19 or V9 erythrovirus infection and onset of ANCA-positive vasculitides.

METHODS

We tested the sera of 13 adults with newly diagnosed ANCA-positive vasculitides. Each was age- and sex-matched to three sera obtained from healthy controls. All samples were tested for B19- and V9-specific immunoglobulin (Ig) G and IgM antibodies (Ab) (third-generation ELISA), and B19 or V9 DNA was sought with the polymerase chain reaction. Statistical analysis was performed by conditional logistic regression.

RESULTS

Patient diagnoses comprised six cases of Wegener's granulomatosis, six of microscopic polyangiitis and one of Churg-Strauss syndrome. IgG Ab to B19 were detected equally in patient and control sera (77 and 79% respectively) (odds ratio=0.84, P=0.84). All 13 cases and 39 controls were negative for IgM Ab and viral DNA.

CONCLUSION

These results suggest that neither acute nor chronic B19 or V9 infection is an aetiological factor in ANCA-associated vasculitides.

Airway management by physicians wearing anti-chemical warfare gear: comparison between laryngeal mask airway and endotracheal intubation

BACKGROUND AND OBJECTIVE

To evaluate the ease with which successful insertion of a laryngeal mask airway can be performed in comparison with endotracheal intubation by medical personnel wearing chemical protective equipment.

METHODS

Anaesthetists and non-anaesthetists (each n = 20) participated in the prospective comparative trial in an animal laboratory. The time and success rates of laryngeal mask airway vs. endotracheal tube insertions were measured as performed on anaesthetized monkeys.

RESULTS

The results showed that the laryngeal mask airway was inserted more rapidly than the endotracheal tube by both groups (3.6 s and 28.6 s, P < 0.0001). Failed intubation occurred in 35% (anaesthetists) vs. 55% (non-anaesthetists) (P = 0.17).

CONCLUSIONS

In view of the 100% success rate of insertion even in unfavourable conditions, the possible role of the laryngeal mask airway in the scenario of a toxic mass casualty event should be considered.

Quantitation of soluble and skeletal alkaline phosphatase, and insoluble alkaline phosphatase anchor-hydrolase activities in human serum

BACKGROUND

The current studies were intended to compare the circulating levels of total and anchorless (soluble) skeletal and hepatic ALP isoenzyme activities, and insoluble ALP anchor-hydrolase activity in serum of postmenopausal women.

METHODS

Preliminary studies of the insoluble ALP anchor-hydrolase activity in serum revealed a pH optimum of pH 5-6.5, a sensitivity to inactivation by heat at temperatures >45 degrees C (t(1/2)=8-9 min at 60 degrees C), and an apparent K(M) (at pH 7.5) of 40-45 mU/ml of insoluble skeletal ALP activity.

RESULTS

Serum analyses showed that 94.5+/-0.5% (mean+/-SEM) of the ALP activity in serum was in the anchorless, soluble form. The data were also consistent with the notion that the amount of insoluble ALP anchor-hydrolase activity in serum, 52.8+/-0.8 U/l (mean+/-SEM), was sufficient for the conversion of anchor-intact (insoluble) ALP into the anchorless, soluble form, assuming activation by serum lipids and/or bile salts. Distributions of results for total, skeletal, hepatic, and insoluble ALP anchor-hydrolase activity were skewed toward the higher range and leptokurtotic (p<0.01 for each). Total ALP activity ranged from 42% to 208% of the group mean value; skeletal, hepatic, and insoluble ALP anchor-hydrolase activities ranged from 5% to 306%, 33% to 277%, and 2% to 325%, respectively. In contrast, the soluble ALP fraction only ranged from 71% to 106% of the group mean value.

CONCLUSIONS

The correlations between the total and both skeletal (r=0.711, p<0.001) and hepatic (r=0.782, p<0.001) ALP isoform activities were predictive. Although correlations were also observed between insoluble ALP anchor-hydrolase activity and total (r=0.197, p<0.001), hepatic (r=0.184, p<0.001) and skeletal ALP activities (r=0.118, p<0.05), those relationships were not predictive (r(2)<0.04).

Induced neuronal differentiation of human embryonic stem cells

Human embryonic stem (ES) cells are pluripotent cells capable of forming differentiated embryoid bodies (EBs) in culture. We examined the ability of growth factors under controlled conditions to increase the number of human ES cell-derived neurons. Retinoic acid (RA) and nerve growth factor (betaNGF) were found to be potent enhancers of neuronal differentiation, eliciting extensive outgrowth of processes and the expression of neuron-specific molecules. Our findings show that human ES cells have great potential to become an unlimited cell source for neurons in culture. These cells may then be used in transplantation therapies for neural pathologies.

Involvement of branched-chain amino acid aminotransferases in the production of fusel alcohols during fermentation in yeast

Organoleptic compounds produced by yeast during the fermentation of wort have a great impact on beer smell and taste. Among them, fusel alcohols are the major abundant volatile compounds. The availability of Saccharomyces cerevisiae mutants in which the genes coding for the two branched-chain amino acid aminotransferases have been deleted offers the possibility of further defining the role of these enzymes in the formation of higher alcohols. Comparing the production profiles of different strains, it is clear that they are not all influenced in the same way by branched-chain amino acid aminotransferase mutations. First of all, as propanol is synthesised from alpha-ketobutyrate, the first metabolic intermediate in the anabolic pathway of isoleucine, neither the eca39 nor eca40 mutations have any effect on the production of this higher alcohol. On the other hand, it can be concluded that the eca40 mutation has a drastic effect on the production of isobutanol. To a certain extent, the same conclusion can be made for the production of active amyl alcohol and isoamyl alcohol, although the results suggest that another route could lead to the formation of these two higher alcohols.

Differentiation of human embryonic stem cells into embryoid bodies compromising the three embryonic germ layers

BACKGROUND

Embryonic stem (ES) cells are lines of cells that are isolated from blastocysts. The murine ES cells were demonstrated to be true pluripotent cells as they differentiate into all embryonic lineages. Yet, in vitro differentiation of rhesus ES cells was somewhat inconsistent and disorganized. The recent isolation of human ES cells calls for exploring their pluripotential nature.

MATERIALS AND METHODS

Human ES cells were grown in suspension to induce their differentiation into embryoid bodies (EBs). The differentiation status of the human ES cells and EBs was analyzed by following the expression pattern of several lineage-specific molecular markers using reverse transcription polymerase chain reaction (RT-PCR) and in situ hybridization.

RESULTS

Here we report the induction in vitro of cystic embryoid bodies from human ES cells. Our findings demonstrate induction of expression of cell-specific genes during differentiation of the human ES cells into EBs. In the human EBs, we could show a characteristic regional expression of embryonic markers specific to different cellular lineages, namely, zeta-globin (mesoderm), neurofilament 68Kd (ectoderm), and alpha-fetoprotein (endoderm). Moreover, we present a synchronously pulsing embryoid body that expresses the myocardium marker alpha-cardiac actin. In addition, dissociating the embryoid bodies and plating the cells as monolayers results in multiple morphologies, among them cells with neuronal appearance that express neurofilament 68Kd chain.

CONCLUSION

Human ES cells can reproducibly differentiate in vitro into EBs comprising the three embryonic germ layers. The ability to induce formation of human embryoid bodies that contain cells of neuronal, hematopoietic and cardiac origins will be useful in studying early human embryonic development as well as in transplantation medicine.

Involvement of branched-chain amino acid aminotransferase (Bcat1/Eca39) in apoptosis

The branched-chain amino acid aminotransferase, Bcat1/Eca39, catalyzes the first step of branched-chain amino acid catabolism. Bcat1/Eca39 was originally isolated from a c-myc-induced tumor and was proven to be a direct target for c-Myc regulation. The gene is highly conserved in evolution and disruption of its yeast homolog affects cell growth. To assess the role of Bcat1/Eca39 in mammalian cells, we overexpressed Bcat1/Eca39 in murine cells and studied effects on cell growth. Overexpression of Bcat1/Eca39 had no apparent effect on the proliferation of cells grown with high serum concentrations, but under serum deprivation conditions, led to a decrease in cell viability. Cell death under these conditions displayed apoptotic features. The branched-chain keto acid, alpha-ketoisocaproate, a metabolite of leucine catabolism produced by BCAT1/ECA39, was previously found to inhibit cell growth. We show that alpha-ketoisocaproate can induce rapid apoptotic cell death. This observation suggests that the growth inhibitory effect of BCAT1/ECA39 and its apoptosis promoting effect may be mediated by the levels of the products of BCAT1/ECA39 activity, namely, branched-chain keto acids.

Characterization of a branched-chain amino-acid aminotransferase from Schizosaccharomyces pombe

The Saccharomyces cerevisiae genes for the cytosolic and mitochondrial branched-chain amino-acid aminotransferases (BCAT) were isolated recently. These genes show significant homology to mammalian ECA39, originally isolated as a gene regulated by the c-myc oncogene. We now report the isolation of the Schizosaccharomyces pombe eca39/BCAT gene. The S. pombe protein shows 47-52% identity to other eukaryotic BCAT proteins isolated from S. cerevisiae, nematode, mouse and man. A genetic growth assay for BCAT activity was established using an S. cerevisiae strain disrupted in both BCAT isoenzymes. Consequently, the activity of the S. pombe BCAT was demonstrated by genetic and biochemical means. Possible applications of BCAT-encoding genes as selection markers in yeast transformation are proposed.

Erythroblastic inclusions in dominantly inherited beta thalassemias

While the precipitation of unstable variant beta-globin chains has been implicated as a major pathogenic mechanism in dominantly inherited beta thalassemia, their instability and presence in intra-erythroblastic inclusions have not been conclusively shown. We report the investigation of two cases of dominantly inherited beta thalassemia due to heterozygosity for the beta-codon 121 G-T mutation. In one case, we were able to demonstrate the presence of an abnormal beta-globin chain in both peripheral blood reticulocytes and bone marrow erythroblasts, and to assess its stability in relation to the substantial amounts of mutant beta mRNA transcript. The serum transferrin receptor (TfR) level was markedly increased, an indication of increased erythropoietic activity. In both cases, we could show by immunoelectron microscopy that the intra-erythroblastic inclusion bodies, a prominent feature of diseases in this category, contained not only precipitated alpha-globin chains, but also beta chains. The data confirm previous suggestions that the cellular pathology underlying this group of beta thalassemias is related to the synthesis of highly unstable beta-globin chain variants, which fail to form functional tetramers and precipitate intracellularly with the concomitant excess alpha chains, leading to increased ineffective erythropoiesis.

Two yeast homologs of ECA39, a target for c-Myc regulation, code for cytosolic and mitochondrial branched-chain amino acid aminotransferases

ECA39 was isolated as a target gene for c-Myc regulation in mice. We identified two homologs for the murine ECA39 in the yeast Saccharomyces cerevisiae, ECA39 and ECA40, as well as two human homologs. These genes show a significant homology to prokaryotic branched-chain amino acid aminotransferase (BCAT) (EC). To understand the function of eukaryotic ECA39 and ECA40, we deleted either gene from the yeast genome. Activity of branched-chain amino acid aminotransferase was measured in the wild-type and mutants with either leucine, isoleucine, or valine as substrates. The results demonstrate that in S. cerevisiae ECA39 and ECA40 code for mitochondrial and cytosolic branched-chain amino acid aminotransferases, respectively. ECA39 is highly expressed during log phase and is down-regulated during the stationary phase of growth, while ECA40 shows an inverse pattern of gene expression. In agreement with these results, while we previously showed that deletion of ECA39 affected the cell cycle in proliferating cells, we do not observe a growth phenotype in eca40Delta cells. We suggest that BCAT is a target for c-Myc activity and discuss the evolutionary conservation of prokaryotic and eukaryotic BCATs and their possible involvement in regulation of cell proliferation.

ECA39, a conserved gene regulated by c-Myc in mice, is involved in G1/S cell cycle regulation in yeast

The c-myc oncogene has been shown to play a role in cell proliferation and apoptosis. The realization that myc oncogenes may control the level of expression of other genes has opened the field to search for genetic targets for Myc regulation. Recently, using a subtraction/coexpression strategy, a murine genetic target for Myc regulation, called EC439, was isolated. To further characterize the ECA39 gene, we set out to determine the evolutionary conservation of its regulatory and coding sequences. We describe the human, nematode, and budding yeast homologs of the mouse ECA39 gene. Identities between the mouse ECA39 protein and the human, nematode, or yeast proteins are 79%, 52%, and 49%, respectively. Interestingly, the recognition site for Myc binding, located 3' to the start site of transcription in the mouse gene, is also conserved in the human homolog. This regulatory element is missing in the ECA39 homologs from nematode or yeast, which also lack the regulator c-myc. To understand the function of ECA39, we deleted the gene from the yeast genome. Disruption of ECA39 which is a recessive mutation that leads to a marked alteration in the cell cycle. Mutant haploids and homozygous diploids have a faster growth rate than isogenic wild-type strains. Fluorescence-activated cell sorter analyses indicate that the mutation shortens the G1 stage in the cell cycle. Moreover, mutant strains show higher rates of UV-induced mutations. The results suggest that the product of ECA39 is involved in the regulation of G1 to S transition.