An Update on Management of Adult Patients with Acute Respiratory Distress Syndrome: An Official American Thoracic Society Clinical Practice Guideline

Background: This document updates previously published Clinical Practice Guidelines for the management of patients with acute respiratory distress syndrome (ARDS), incorporating new evidence addressing the use of corticosteroids, venovenous extracorporeal membrane oxygenation, neuromuscular blocking agents, and positive end-expiratory pressure (PEEP). Methods: We summarized evidence addressing four "PICO questions" (patient, intervention, comparison, and outcome). A multidisciplinary panel with expertise in ARDS used the Grading of Recommendations, Assessment, Development, and Evaluation framework to develop clinical recommendations. Results: We suggest the use of: 1) corticosteroids for patients with ARDS (conditional recommendation, moderate certainty of evidence), 2) venovenous extracorporeal membrane oxygenation in selected patients with severe ARDS (conditional recommendation, low certainty of evidence), 3) neuromuscular blockers in patients with early severe ARDS (conditional recommendation, low certainty of evidence), and 4) higher PEEP without lung recruitment maneuvers as opposed to lower PEEP in patients with moderate to severe ARDS (conditional recommendation, low to moderate certainty), and 5) we recommend against using prolonged lung recruitment maneuvers in patients with moderate to severe ARDS (strong recommendation, moderate certainty). Conclusions: We provide updated evidence-based recommendations for the management of ARDS. Individual patient and illness characteristics should be factored into clinical decision making and implementation of these recommendations while additional evidence is generated from much-needed clinical trials.

[Advances in the application of prosthetic reconstruction after tumor resection of the distal tibia:a systematic review]

The limited coverage of soft tissue and complex biomechanical factors make resection and reconstruction of distal tibial tumors extremely challenging. Megaprosthesis can provide good mechanical strength for tumor en bloc resection, but there are many postoperative complications, and the problems of insufficient soft tissue coverage and postoperative ankle instability must be solved. The development of three-dimensional digital technology may provide a new treatment strategy for distal tibial reconstruction. Compared to ankle joint preservation endoprostheses, the rapid osseointegration effect of three dimensional-printed megaprosthesis with ankle arthrodesis provides better ankle joint stability and postoperative function. In addition, the three dimensional-printed megaprosthesis may improve complications such as insufficient soft tissue coverage and talus collapse by reducing the circumference of the prosthesis and matching it with the talus through personalized design. Of course, there are few research reports on distal tibial prostheses, and the safety of three dimensional-printed megaprosthesis with ankle arthrodesis needs to be confirmed through extensive long-term follow-up studies. The selection of proximal and distal fixation methods for prostheses needs to be explored in future research.

Validation of automated data abstraction for SCCM discovery VIRUS COVID-19 registry: practical EHR export pathways (VIRUS-PEEP)

Background

The gold standard for gathering data from electronic health records (EHR) has been manual data extraction; however, this requires vast resources and personnel. Automation of this process reduces resource burdens and expands research opportunities.

Objective

This study aimed to determine the feasibility and reliability of automated data extraction in a large registry of adult COVID-19 patients.

Materials and methods

This observational study included data from sites participating in the SCCM Discovery VIRUS COVID-19 registry. Important demographic, comorbidity, and outcome variables were chosen for manual and automated extraction for the feasibility dataset. We quantified the degree of agreement with Cohen's kappa statistics for categorical variables. The sensitivity and specificity were also assessed. Correlations for continuous variables were assessed with Pearson's correlation coefficient and Bland-Altman plots. The strength of agreement was defined as almost perfect (0.81-1.00), substantial (0.61-0.80), and moderate (0.41-0.60) based on kappa statistics. Pearson correlations were classified as trivial (0.00-0.30), low (0.30-0.50), moderate (0.50-0.70), high (0.70-0.90), and extremely high (0.90-1.00).

Measurements and main results

The cohort included 652 patients from 11 sites. The agreement between manual and automated extraction for categorical variables was almost perfect in 13 (72.2%) variables (Race, Ethnicity, Sex, Coronary Artery Disease, Hypertension, Congestive Heart Failure, Asthma, Diabetes Mellitus, ICU admission rate, IMV rate, HFNC rate, ICU and Hospital Discharge Status), and substantial in five (27.8%) (COPD, CKD, Dyslipidemia/Hyperlipidemia, NIMV, and ECMO rate). The correlations were extremely high in three (42.9%) variables (age, weight, and hospital LOS) and high in four (57.1%) of the continuous variables (Height, Days to ICU admission, ICU LOS, and IMV days). The average sensitivity and specificity for the categorical data were 90.7 and 96.9%.

Conclusion and relevance

Our study confirms the feasibility and validity of an automated process to gather data from the EHR.

Decreased Utilization of Low Tidal Volume Ventilation Outside of the Intensive Care Unit as Compared to Inside

Background: Investigations into the use of low tidal volume ventilation (LTVV) have been performed for patients in emergency departments (EDs) or intensive care units (ICUs). Practice differences between the ICU and non-ICU care areas have not been described. We hypothesized that the initial implementation of LTVV would be better inside ICUs than outside. Methods: This is a retrospective observational study of patients initiated on invasive mechanical ventilation (IMV) between January 1, 2016, and July 17, 2019. Initial recorded tidal volumes after intubation were used to compare the use of LTVV between care areas. Low tidal volume was considered 6.5 cc/kg of ideal body weight (IBW) or less. The primary outcome was the initiation of low tidal volume. Sensitivity analyses used a tidal volume of 8 cc/kg of IBW or less, and direct comparisons were performed between the ICU, ED, and wards. Results: There were 6392 initiations of IMV: 2217 (34.7%) in the ICU and 4175 (65.3%) outside. LTVV was more likely to be initiated in the ICU than outside (46.5% vs 34.2%; adjusted odds ratio [aOR] 0.62, 95% confidence interval [CI] 0.56-0.71, P < .01). The ICU also had more implementation when PaO2/FiO2 ratio was less than 300, (48.0% vs 34.6%; aOR 0.59, 95% CI 0.48-0.71, P < .01). When comparing individual locations, wards had lower odds of LTVV than the ICU (aOR 0.82, 95% CI 0.70-0.96, P  =  .02), the ED had lower odds than the ICU (aOR 0.55, 95% CI 0.48-0.63, P < .01), and the ED had lower odds than the wards (aOR 0.66, 95% CI 0.56-0.77, P < .01). Interpretation: Initial low tidal volumes were more likely to be initiated in the ICU than outside. This finding remained when examining only patients with a PaO2/FiO2 ratio less than 300. Care areas outside of the ICU do not employ LTVV as often as ICUs and are, therefore, a possible target for process improvement.

Long short-term memory model identifies ARDS and in-hospital mortality in both non-COVID-19 and COVID-19 cohort

OBJECTIVE

To identify the risk of acute respiratory distress syndrome (ARDS) and in-hospital mortality using long short-term memory (LSTM) framework in a mechanically ventilated (MV) non-COVID-19 cohort and a COVID-19 cohort.

METHODS

We included MV ICU patients between 2017 and 2018 and reviewed patient records for ARDS and death. Using active learning, we enriched this cohort with MV patients from 2016 to 2019 (MV non-COVID-19, n=3905). We collected a second validation cohort of hospitalised patients with COVID-19 in 2020 (COVID+, n=5672). We trained an LSTM model using 132 structured features on the MV non-COVID-19 training cohort and validated on the MV non-COVID-19 validation and COVID-19 cohorts.

RESULTS

Applying LSTM (model score 0.9) on the MV non-COVID-19 validation cohort had a sensitivity of 86% and specificity of 57%. The model identified the risk of ARDS 10 hours before ARDS and 9.4 days before death. The sensitivity (70%) and specificity (84%) of the model on the COVID-19 cohort are lower than MV non-COVID-19 cohort. For the COVID-19 + cohort and MV COVID-19 + patients, the model identified the risk of in-hospital mortality 2.4 days and 1.54 days before death, respectively.

DISCUSSION

Our LSTM algorithm accurately and timely identified the risk of ARDS or death in MV non-COVID-19 and COVID+ patients. By alerting the risk of ARDS or death, we can improve the implementation of evidence-based ARDS management and facilitate goals-of-care discussions in high-risk patients.

CONCLUSION

Using the LSTM algorithm in hospitalised patients identifies the risk of ARDS or death.

Assessing a standardized decision-making algorithm for blood culture collection in the intensive care unit

PURPOSE

Blood cultures are commonly ordered for patients with low risk of bacteremia. Indications for obtaining blood cultures are often broad and ill defined, and decision algorithms for appropriate blood cultures have not been comprehensively evaluated in critically-ill populations.

METHODS

We conducted a retrospective analysis to assess the frequency of inappropriate blood cultures in the ICUs at Montefiore Medical Center based on an evidence-based guidance algorithm. Blood cultures were reviewed against this algorithm to determine their appropriateness. We calculated the prevalence of inappropriate blood culture and explored the reasons for these collected cultures.

RESULTS

300 patients were randomly selected from an initial cohort of 3370 patients. 294 patients were included and of these, 167 patients had at least 1 blood culture drawn. 125 patients had one or more inappropriate blood culture. 61.4% of blood cultures drawn were assessed to be inappropriate. The most common reason for inappropriate cultures was a culture drawn as a result of isolated fever or leukocytosis.

CONCLUSION

In a cohort of critically-ill patients, inappropriate blood cultures were common. The indications for blood cultures are often not evidence-based, and evidence-based algorithms to guide the collection of blood cultures may offer a way to decrease inappropriate culture orders.

Wellness and Coping of Physicians Who Worked in ICUs During the Pandemic: A Multicenter Cross-Sectional North American Survey

OBJECTIVES

Few surveys have focused on physician moral distress, burnout, and professional fulfilment. We assessed physician wellness and coping during the COVID-19 pandemic.

DESIGN

Cross-sectional survey using four validated instruments.

SETTING

Sixty-two sites in Canada and the United States.

SUBJECTS

Attending physicians (adult, pediatric; intensivist, nonintensivist) who worked in North American ICUs.

INTERVENTION

None.

MEASUREMENTS AND MAIN RESULTS

We analysed 431 questionnaires (43.3% response rate) from 25 states and eight provinces. Respondents were predominantly male (229 [55.6%]) and in practice for 11.8 ± 9.8 years. Compared with prepandemic, respondents reported significant intrapandemic increases in days worked/mo, ICU bed occupancy, and self-reported moral distress (240 [56.9%]) and burnout (259 [63.8%]). Of the 10 top-ranked items that incited moral distress, most pertained to regulatory/organizational ( n = 6) or local/institutional ( n = 2) issues or both ( n = 2). Average moral distress (95.6 ± 66.9), professional fulfilment (6.5 ± 2.1), and burnout scores (3.6 ± 2.0) were moderate with 227 physicians (54.6%) meeting burnout criteria. A significant dose-response existed between COVID-19 patient volume and moral distress scores. Physicians who worked more days/mo and more scheduled in-house nightshifts, especially combined with more unscheduled in-house nightshifts, experienced significantly more moral distress. One in five physicians used at least one maladaptive coping strategy. We identified four coping profiles (active/social, avoidant, mixed/ambivalent, infrequent) that were associated with significant differences across all wellness measures.

CONCLUSIONS

Despite moderate intrapandemic moral distress and burnout, physicians experienced moderate professional fulfilment. However, one in five physicians used at least one maladaptive coping strategy. We highlight potentially modifiable factors at individual, institutional, and regulatory levels to enhance physician wellness.

SWEAT ICU-An Observational Study of Physician Workload and the Association of Physician Outcomes in Academic ICUs

The optimal staffing model for physicians in the ICU is unknown. Patient-to-intensivist ratios may offer a simple measure of workload and be associated with patient mortality and physician burnout. To evaluate the association of physician workload, as measured by the patient-to-intensivist ratio, with physician burnout and patient mortality.

DESIGN

Cross-sectional observational study.

SETTING

Fourteen academic centers in the United States from August 2020 to July 2021.

SUBJECTS

We enrolled ICU physicians and collected data on adult ICU patients under the physician's care on the single physician-selected study day for each physician.

MEASUREMENTS and MAIN RESULTS

The primary exposure was workload (self-reported number of patients' physician was responsible for) modeled as high (>14 patients) and low (≤14 patients). The primary outcome was burnout, measured by the Well-Being Index. The secondary outcome measure was 28-day patient mortality. We calculated odds ratio for burnout and patient outcomes using a multivariable logistic regression model and a binomial mixed effects model, respectively. We enrolled 122 physicians from 62 ICUs. The median patient-to-intensivist ratio was 12 (interquartile range, 10-14), and the overall prevalence of burnout was 26.4% (n = 32). Intensivist workload was not independently associated with burnout (adjusted odds ratio, 0.74; 95% CI, 0.24-2.23). Of 1,322 patients, 679 (52%) were discharged alive from the hospital, 257 (19%) remained hospitalized, and 347 (26%) were deceased by day 28; 28-day outcomes were unknown for 39 of patients (3%). Intensivist workload was not independently associated with 28-day patient mortality (adjusted odds ratio, 1.33; 95% CI, 0.92-1.91).

CONCLUSIONS

In our cohort, approximately one in four physicians experienced burnout on the study day. There was no relationship be- tween workload as measured by patient-to-intensivist ratio and burnout. Factors other than the number of patients may be important drivers of burnout among ICU physicians.

Quantifying Utilitarian Outcomes to Inform Triage Ethics: Simulated Performance of a Ventilator Triage Protocol under Sars-CoV-2 Pandemic Surge Conditions

BACKGROUND

Equitable protocols to triage life-saving resources must be specified prior to shortages in order to promote transparency, trust and consistency. How well proposed utilitarian protocols perform to maximize lives saved is unknown. We aimed to estimate the survival rates that would be associated with implementation of the New York State 2015 guidelines for ventilator triage, and to compare them to a first-come-first-served triage method.

METHODS

We constructed a simulation model based on a modified version of the New York State 2015 guidelines compared to a first-come-first-served method under various hypothetical ventilator shortages. We included patients with SARs-CoV-2 infection admitted with respiratory failure requiring mechanical ventilation to three acute care hospitals in New York from 3/01/2020 and 5/27/2020. We estimated (1) survival rates, (2) number of excess deaths, (3) number of patients extubated early or not allocated a ventilator due to capacity constraints, (4) survival rates among patients not allocated a ventilator at triage or extubated early due to capacity constraints.

RESULTS

807 patients were included in the study. The simulation model based on a modified New York State policy did not decrease mortality, excess death or exclusion from ventilators compared to the first-come-first-served policy at every ventilator capacity we tested using COVID-19 surge cohort patients. Survival rates were similar at all the survival probabilities estimated. At the lowest ventilator capacity, the modified New York State policy has an estimated survival of 28.5% (CI: 28.4-28.6), compared to 28.1% (CI: 27.7-28.5) for the first-come-first-served policy.

CONCLUSIONS

This simulation of a modified New York State guideline-based triage protocol revealed limitations in achieving the utilitarian goals these protocols are designed to fulfill. Quantifying these outcomes can inform a better balance among competing moral aims.

[The clinical value of oral robotic surgery in the treatment of oropharyngeal squamous cell carcinoma]

Objective: To explore the therapeutic effects of transoral robotic surgery (TORS) and traditional surgical modes in oropharyngeal squamous cell carcinoma (OPSCC). Methods: The clinicopathological data of patients with oropharyngeal squamous cell carcinoma treated at Sun Yat-sen University Cancer Center from 2010 to 2018 were retrospectively analyzed. 135 cases were treated with traditional surgery (non-TORS group), while 52 cases were treated with TORS (TORS group). The prognosis of the two groups of patients were analyzed by Kaplan-Meier method and Log rank test, the influencing factors were analyzed by Cox regression model. Results: The 2-year overall survival (OS, 94.2%) and 2-year progression-free survival (PFS, 93.8%) of patients in the TORS group were better than those in the non-TORS group (71.4% and 71.4%, respectively, P<0.05). The 2-year OS (93.3%) and 2-year PFS (92.8%) of TORS group patients in T1-2 stage were better than those of non-TORS group (73.1% and 72.8%, respectively, P<0.05). The 2-year OS (95.8%) and 2-year PFS (95.2%) of patients with stage Ⅰ to Ⅱ in the TORS group were not significantly different from those in the non-TORS group (84.1% and 83.9%, respectively, P>0.05). The 2-year OS (92.9%) and 2-year PFS rate (92.7%) of patients with stage Ⅲ to Ⅳ in the TORS group were better than those in the non-TORS group (64.7% and 63.9%, respectively, P<0.05). The 2-year OS (94.4%) of HPV-positive patients in the TORS group was not significantly different from that in the non-TORS group (83.3%, P=0.222). The 2-year OS of HPV-negative patients in the TORS group (94.1%) was significantly different from that in the non-TORS group (43.7%, P<0.001). HPV status was an independent prognostic factor (P=0.008). Conclusions: TORS has a better prognosis in the treatment of oropharyngeal squamous cell carcinoma compared with the traditional treatment methods. The patients with T1-T2 can achieve better survival benefits after TORS treatment. The HPV-positive OPSCC patients has a better prognosis than that of HPV-negative OPSCC patients, and regardless of HPV status, OPSCC patients in the TORS group could obtain a better survival prognosis.

[Application of transoral robotic surgery in treatment of oropharyngeal squamous cell carcinoma]

Objective: To evaluate the therapeutic and prognostic outcomes of transoral robotic surgery (TORS) for oropharyngeal squamous cell carcinoma (OSCC). Methods: A retrospective study of 99 OSCC patients treated with TORS in Department of Head and Neck Surgery, Sun Yat-sen University Cancer Center between April 2017 and May 2021 was conducted. There were 84 males and 15 females, with an age range of 35-85 years. Patients' clinical characteristics, including clinical staging, HPV infection status, perioperative management and postoperative adjuvant treatment, were recorded. The overall survival (OS) and progression-free survival (PFS) were analyzed. The survival outcomes were analyzed with Kaplan-Meier method and Log-rank test. Results: The hospital stay of OSCC patients with TORS was (5.3±2.9) days and the average time of postoperative nasal feeding tube indwelling was (15.2±10.8) days. Among the 99 patients, 21 (21.2%) received tracheotomy and the average time of tracheotomy tube indwelling was (11.9±11.4) days. The two-year OS and PFS in patients with follow-up over two years were 94.0% and 87.7%, respectively and the three-year OS and PFS of patients with follow-up over three years were 94.0% and 78.9%, respectively. The two-year OS and PFS were respectively 97.4% and 88.9%, for patients with stages I-II and 86.8% and 88.9% for patients with stages III-IV. HPV-negative and HPV-positive patients had respectively two-year OS (100.0% vs. 91.5%) and PFS (88.9% vs. 87.2%). There was no significantly statistical difference in survival between patients with and without adjuvant radiotherapy after TORS (82.6% vs. 90.5%, HR=0.52, 95%CI: 0.12-2.23, P=0.400). Conclusions: TORS is more suitable for the treatment of patients with early (Ⅰ-Ⅱ) or HPV-positive oropharyngeal squamous cell carcinoma, and the recovery after TORS treatment is good.

Variation in Early Management Practices in Moderate-to-Severe ARDS in the United States: The Severe ARDS: Generating Evidence Study

BACKGROUND

Although specific interventions previously demonstrated benefit in patients with ARDS, use of these interventions is inconsistent, and patient mortality remains high. The impact of variability in center management practices on ARDS mortality rates remains unknown.

RESEARCH QUESTION

What is the impact of treatment variability on mortality in patients with moderate to severe ARDS in the United States?

STUDY DESIGN AND METHODS

We conducted a multicenter, observational cohort study of mechanically ventilated adults with ARDS and Pao2 to Fio2 ratio of ≤ 150 with positive end-expiratory pressure of ≥ 5 cm H2O, who were admitted to 29 US centers between October 1, 2016, and April 30, 2017. The primary outcome was 28-day in-hospital mortality. Center variation in ventilator management, adjunctive therapy use, and mortality also were assessed.

RESULTS

A total of 2,466 patients were enrolled. Median baseline Pao2 to Fio2 ratio was 105 (interquartile range, 78.0-129.0). In-hospital 28-day mortality was 40.7%. Initial adherence to lung protective ventilation (LPV; tidal volume, ≤ 6.5 mL/kg predicted body weight; plateau pressure, or when unavailable, peak inspiratory pressure, ≤ 30 mm H2O) was 31.4% and varied between centers (0%-65%), as did rates of adjunctive therapy use (27.1%-96.4%), methods used (neuromuscular blockade, prone positioning, systemic steroids, pulmonary vasodilators, and extracorporeal support), and mortality (16.7%-73.3%). Center standardized mortality ratios (SMRs), calculated using baseline patient-level characteristics to derive expected mortality rate, ranged from 0.33 to 1.98. Of the treatment-level factors explored, only center adherence to early LPV was correlated with SMR.

INTERPRETATION

Substantial center-to-center variability exists in ARDS management, suggesting that further opportunities for improving ARDS outcomes exist. Early adherence to LPV was associated with lower center mortality and may be a surrogate for overall quality of care processes. Future collaboration is needed to identify additional treatment-level factors influencing center-level outcomes.

TRIAL REGISTRY

ClinicalTrials.gov; No.: NCT03021824; URL: www.clinicaltrials.gov.

Therapeutic Anticoagulation with Heparin in Noncritically Ill Patients with Covid-19

BACKGROUND

Thrombosis and inflammation may contribute to the risk of death and complications among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation may improve outcomes in noncritically ill patients who are hospitalized with Covid-19.

METHODS

In this open-label, adaptive, multiplatform, controlled trial, we randomly assigned patients who were hospitalized with Covid-19 and who were not critically ill (which was defined as an absence of critical care-level organ support at enrollment) to receive pragmatically defined regimens of either therapeutic-dose anticoagulation with heparin or usual-care pharmacologic thromboprophylaxis. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge. This outcome was evaluated with the use of a Bayesian statistical model for all patients and according to the baseline d-dimer level.

RESULTS

The trial was stopped when prespecified criteria for the superiority of therapeutic-dose anticoagulation were met. Among 2219 patients in the final analysis, the probability that therapeutic-dose anticoagulation increased organ support-free days as compared with usual-care thromboprophylaxis was 98.6% (adjusted odds ratio, 1.27; 95% credible interval, 1.03 to 1.58). The adjusted absolute between-group difference in survival until hospital discharge without organ support favoring therapeutic-dose anticoagulation was 4.0 percentage points (95% credible interval, 0.5 to 7.2). The final probability of the superiority of therapeutic-dose anticoagulation over usual-care thromboprophylaxis was 97.3% in the high d-dimer cohort, 92.9% in the low d-dimer cohort, and 97.3% in the unknown d-dimer cohort. Major bleeding occurred in 1.9% of the patients receiving therapeutic-dose anticoagulation and in 0.9% of those receiving thromboprophylaxis.

CONCLUSIONS

In noncritically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin increased the probability of survival to hospital discharge with reduced use of cardiovascular or respiratory organ support as compared with usual-care thromboprophylaxis. (ATTACC, ACTIV-4a, and REMAP-CAP ClinicalTrials.gov numbers, NCT04372589, NCT04505774, NCT04359277, and NCT02735707.).

Therapeutic Anticoagulation with Heparin in Critically Ill Patients with Covid-19

BACKGROUND

Thrombosis and inflammation may contribute to morbidity and mortality among patients with coronavirus disease 2019 (Covid-19). We hypothesized that therapeutic-dose anticoagulation would improve outcomes in critically ill patients with Covid-19.

METHODS

In an open-label, adaptive, multiplatform, randomized clinical trial, critically ill patients with severe Covid-19 were randomly assigned to a pragmatically defined regimen of either therapeutic-dose anticoagulation with heparin or pharmacologic thromboprophylaxis in accordance with local usual care. The primary outcome was organ support-free days, evaluated on an ordinal scale that combined in-hospital death (assigned a value of -1) and the number of days free of cardiovascular or respiratory organ support up to day 21 among patients who survived to hospital discharge.

RESULTS

The trial was stopped when the prespecified criterion for futility was met for therapeutic-dose anticoagulation. Data on the primary outcome were available for 1098 patients (534 assigned to therapeutic-dose anticoagulation and 564 assigned to usual-care thromboprophylaxis). The median value for organ support-free days was 1 (interquartile range, -1 to 16) among the patients assigned to therapeutic-dose anticoagulation and was 4 (interquartile range, -1 to 16) among the patients assigned to usual-care thromboprophylaxis (adjusted proportional odds ratio, 0.83; 95% credible interval, 0.67 to 1.03; posterior probability of futility [defined as an odds ratio <1.2], 99.9%). The percentage of patients who survived to hospital discharge was similar in the two groups (62.7% and 64.5%, respectively; adjusted odds ratio, 0.84; 95% credible interval, 0.64 to 1.11). Major bleeding occurred in 3.8% of the patients assigned to therapeutic-dose anticoagulation and in 2.3% of those assigned to usual-care pharmacologic thromboprophylaxis.

CONCLUSIONS

In critically ill patients with Covid-19, an initial strategy of therapeutic-dose anticoagulation with heparin did not result in a greater probability of survival to hospital discharge or a greater number of days free of cardiovascular or respiratory organ support than did usual-care pharmacologic thromboprophylaxis. (REMAP-CAP, ACTIV-4a, and ATTACC ClinicalTrials.gov numbers, NCT02735707, NCT04505774, NCT04359277, and NCT04372589.).

[Drug-resistant gene polymorphisms in Plasmodium falciparum isolated from Bioko Island, Equatorial Guinea in 2018 and 2019]

OBJECTIVE

To investigate the genetic polymorphisms of Plasmodium falciparum multidrug resistance protein 1 (PfMDR1), chloroquine resistance transporter (PfCRT) and Kelch 13 (PfK13) genes in Bioko Island, Equatorial Guinea, so as to provide insights into the development of the malaria control strategy in local areas.

METHODS

A total of 85 peripheral blood samples were collected from patients with Plasmodium falciparum infections in Bioko Island, Equatorial Guinea in 2018 and 2019, and genomic DNA was extracted. The PfMDR1, PfCRT and PfK13 genes were amplified using a nested PCR assay. The amplification products were sequenced, and the gene sequences were aligned.

RESULTS

There were no mutations associated with artemisinin resistance in PfK13 gene in Bioko Island, Equatorial Guinea, while drug-resistant mutations were detected in PfMDR1 and PfCRT genes, and the proportions of PfMDR1_N86Y, PfMDR1_Y184F and PfCRT_K76T mutations were 35.29% (30/85), 72.94% (62/85) and 24.71% (21/85), respectively.

CONCLUSIONS

There are mutations in PfMDR1, PfCRT and PfK13 genes in P. falciparum isolates from Bioko Island, Equatorial Guinea.

Practice, Outcomes, and Complications of Emergent Endotracheal Intubation by Critical Care Practitioners During the COVID-19 Pandemic

Background

For patients with COVID-19 who undergo emergency endotracheal intubation, data are limited regarding the practice, outcomes, and complications of this procedure.

Research Question

For patients with COVID-19 requiring emergency endotracheal intubation, how do the procedural techniques, the incidence of first-pass success, and the complications associated with the procedure compare with intubations of critically ill patients before the COVID-19 pandemic?

Study Design and Methods

We conducted a retrospective study of adult patients with COVID-19 at Montefiore Medical Center who underwent first-time endotracheal intubation by critical care physicians between July 19, 2019, and May 1, 2020. The first COVID-19 patient was admitted to our institution on March 11, 2020; patients admitted before this date are designated the prepandemic cohort. Descriptive statistics were used to compare groups. A Fisher exact test was used to compare categorical variables. For continuous variables, a two-tailed Student t test was used for parametric variables or a Wilcoxon rank-sum test was used for nonparametric variables.

Results

One thousand two hundred sixty intubations met inclusion criteria (782 prepandemic cohort, 478 pandemic cohort). Patients during the pandemic were more likely to be intubated for hypoxemic respiratory failure (72.6% vs 28.1%; P < .01). During the pandemic, operators were more likely to use video laryngoscopy (89.4% vs 53.3%; P < .01) and neuromuscular blocking agents (86.0% vs 46.2%; P < .01). First-pass success was higher during the pandemic period (94.6% vs 82.9%; P < .01). The rate of associated complications was higher during the pandemic (29.5% vs 15.2%; P < .01), a finding driven by a higher rate of hypoxemia during or immediately after the procedure (25.7% vs 8.2%; P < .01).

Interpretation

Video laryngoscopy and neuromuscular blockade were used increasingly during the COVID-19 pandemic. Despite a higher rate of first-pass success during the pandemic, the incidence of complications associated with the procedure was higher.

The Impact of High-Flow Nasal Cannula Use on Patient Mortality and the Availability of Mechanical Ventilators in COVID-19

Rationale: How to provide advanced respiratory support for coronavirus disease (COVID-19) to maximize population-level survival while optimizing mechanical ventilator access is unknown.Objectives: To evaluate the use of high-flow nasal cannula for COVID-19 on population-level mortality and ventilator availability.Methods: We constructed dynamical (deterministic) simulation models of high-flow nasal cannula and mechanical ventilation use for COVID-19 in the United States. Model parameters were estimated through consensus based on published literature, local data, and experience. We had the following two outcomes: 1) cumulative number of deaths and 2) days without any available ventilators. We assessed the impact of various policies for the use of high-flow nasal cannula (with or without "early intubation") versus a scenario in which high-flow nasal cannula was unavailable.Results: The policy associated with the fewest deaths and the least time without available ventilators combined the use of high-flow nasal cannula for patients not urgently needing ventilators with the use of early mechanical ventilation for these patients when at least 10% of ventilator supply was not in use. At the national level, this strategy resulted in 10,000-40,000 fewer deaths than if high-flow nasal cannula were not available. In addition, with moderate national ventilator capacity (30,000-45,000 ventilators), this strategy led to up to 25 (11.8%) fewer days without available ventilators. For a 250-bed hospital with 100 mechanical ventilators, the availability of 13, 20, or 33 high-flow nasal cannulas prevented 81, 102, and 130 deaths, respectively.Conclusions: The use of high-flow nasal cannula coupled with early mechanical ventilation when supply is sufficient results in fewer deaths and greater ventilator availability.

Novel REST Truncation Mutations Causing Hereditary Gingival Fibromatosis

Hereditary gingival fibromatosis (HGF) is a rare genetic disorder featured by nonsyndromic pathological overgrowth of gingiva. The excessive gingival tissues can cause dental, masticatory, and phonetic problems, which impose severe functional and esthetic burdens on affected individuals. Due to its high recurrent rate, patients with HGF have to undergo repeated surgical procedures of gingival resection, from childhood to adulthood, which significantly compromises their quality of life. Unraveling the genetic etiology and molecular pathogenesis of HGF not only gains insight into gingival physiology and homeostasis but also opens avenues for developing potential therapeutic strategies for this disorder. Recently, mutations in REST (OMIM *600571), encoding a transcription repressor, were reported to cause HGF (GINGF5; OMIM #617626) in 3 Turkish families. However, the functions of REST in gingival homeostasis and pathogenesis of REST-associated HGF remain largely unknown. In this study, we characterized 2 HGF families and identified 2 novel REST mutations, c.2449C>T (p.Arg817*) and c.2771_2793dup (p.Glu932Lysfs*3). All 5 mutations reported to date are nonsenses or frameshifts in the last exon of REST and would presumably truncate the protein. In vitro reporter gene assays demonstrated a partial or complete loss of repressor activity for these truncated RESTs. When coexpressed with the full-length protein, the truncated RESTs impaired the repressive ability of wild-type REST, suggesting a dominant negative effect. Immunofluorescent studies showed nuclear localization of overexpressed wild-type and truncated RESTs in vitro, indicating preservation of the nuclear localization signal in shortened proteins. Immunohistochemistry demonstrated a comparable pattern of ubiquitous REST expression in both epithelium and lamina propria of normal and HGF gingival tissues despite a reduced reactivity in HGF gingiva. Results of this study confirm the pathogenicity of REST truncation mutations occurring in the last exon causing HGF and suggest the pathosis is caused by an antimorphic (dominant negative) disease mechanism.

The Face of COVID-19: Facial Pressure Wounds Related to Prone Positioning in Patients Undergoing Ventilation in the Intensive Care Unit

In the setting of COVID-19 (coronavirus disease 2019)-associated moderate and severe acute respiratory distress, persistently hypoxemic patients often require prone positioning for >16 hours. We report facial pressure wounds and ear necrosis as a consequence of prone positioning in patients undergoing ventilation in the intensive care unit in a tertiary medical center in New York City.

Effect of Systemic Glucocorticoids on Mortality or Mechanical Ventilation in Patients With COVID-19

The efficacy of glucocorticoids in COVID-19 is unclear. This study was designed to determine whether systemic glucocorticoid treatment in COVID-19 patients is associated with reduced mortality or mechanical ventilation. This observational study included 1,806 hospitalized COVID-19 patients; 140 were treated with glucocorticoids within 48 hours of admission. Early use of glucocorticoids was not associated with mortality or mechanical ventilation. However, glucocorticoid treatment of patients with initial C-reactive protein (CRP) ≥20 mg/dL was associated with significantly reduced risk of mortality or mechanical ventilation (odds ratio, 0.23; 95% CI, 0.08-0.70), while glucocorticoid treatment of patients with CRP <10 mg/dL was associated with significantly increased risk of mortality or mechanical ventilation (OR, 2.64; 95% CI, 1.39-5.03). Whether glucocorticoid treatment is associated with changes in mortality or mechanical ventilation in patients with high or low CRP needs study in prospective, randomized clinical trials.

Metabolites: Reductive Dechlorination of DDT to DDD and Isomeric Transformation of o,p’-DDT to p,p’-DDT In Vivo

Feeding p,p’-DDT and o,p’-DDT separately at a level of 50 ppm in the diet of rats causes reductive dechlorination of DDT to DDD in the liver. No DDD was found in the fat. DDE is not involved in the metabolic pathway. Feeding o,p’-DDT yields evidence of isomeric conversion to p,p’-DDT in the fat stores. The proportion of the p,p’-DDT found to the o,p’-isomer observed is approximately 7:1.

Optimal acquisition time to discriminate between breast cancer subtypes with contrast-enhanced cone-beam CT

PURPOSE

To identify the optimal acquisition time to best discriminate between benign and malignant breast lesions on contrast-enhanced cone beam CT (CE-CBCT) and evaluate the potential of CE-CBCT to differentiate between breast cancer subtypes.

MATERIAL AND METHOD

A total of 98 women with a mean age of 49±10 (SD) years (range: 29-77 years) with 100 BI-RADS 4 or 5 breast lesions were prospectively included. CE-CBCT images were obtained at 1- and 2-min after intravenous administration of iodinated contrast material. Contrast enhancement of breast lesions on CE-CBCT were evaluated and compared between different subtypes. Cut-off values for best discriminating between benign and malignant breast lesions with CE-CBCT were obtained from receiver operating characteristic curves.

RESULTS

Malignant breast lesions showed greater enhancement than benign ones at 1-min (67.28±39.79 [SD] HU vs. 42.27±40.31 [SD] HU, respectively; P=0.007) and 2-min (70.93±38.05 [SD] HU vs. 48.94±41.83 [SD] HU, respectively; P=0.016) after intravenous administration of contrast material. At 1-min after intravenous administration of contrast material, an optimal cut-off value of 54.43 HU was found to best discriminate between malignant and benign breast lesions (AUC=0.681; 95%CI: 0.558-0.805; P=0.006) yielding 69.0% sensitivity (95%CI: 56.9-79.5%) and 69.2% specificity (95% CI: 48.2-85.7%). At 2-min, an optimal cut-off value of 72.65 HU was found to best discriminate between malignant and benign breast lesions (AUC=0.654; 95%CI: 0.535-0.774; P=0.020) yielding 50.7% sensitivity (95%CI: 38.6-62.8%) and 80.8% specificity (95%CI: 60.6-93.4%). CE-CBCT helped differentiate between immunohistochemical subtypes of breast lesions with lowest enhancement for triple negative lesions. No differences in enhancement were found among histopathological subtypes lesions at 1-min (P=0.478) and 2-min (P=0.625).

CONCLUSION

CE-CBCT helps discriminate between malignant and benign breast lesions, with best capabilities obtained at 1-min after intravenous administration of contrast material. For malignant lesions, quantitative analysis of enhancement on CE-CBCT helps differentiate between immunohistochemical subtypes.

[Effect of skin soft tissue expansion on repair of large area of scars on extremities]

Objective: To investigate the effect of skin soft tissue expansion on repair of large area of scars on extremities. Methods: Twenty-five patients with large area of scars on extremities were admitted to our department from June 2007 to October 2014. There were 14 males and 11 females, aged 4 to 36 years. Operations were performed under local infiltration anesthesia or general anesthesia. In the first stage, 1 to 5 cylindrical expanders with capacities of 250 to 600 mL were placed at left or right sides or at upper or lower parts of the scars. In the second stage, scars of 21 patients were repaired with expanded transverse propulsive and lateral flaps, and scars of 4 patients were repaired with expanded perforator flaps whose pedicles were perforators of brachial artery, superior ulnar collateral artery, or posterior interosseous artery according to areas and shapes of the scars. The secondary wound areas ranged from 13 cm×7 cm to 34 cm×18 cm after dissolution or excision of scars. The areas of flaps ranged from 13 cm×7 cm to 20 cm×12 cm. The donor sites were sutured directly. The flaps after operation and follow-up of patients were observed and recorded. Results: All expanded flaps survived after operation. And the superficial distal part of flap whose pedicle was perforator of posterior interosseous artery in one patient was with necrosis, and other flaps survived well. During follow-up of 3 to 15 months after operation of the second stage, color and texture of flaps were similar to surrounding skin, while extremities of donor sites were thinner and auxiliary incisional scars formed after expansion. Conclusions: Expanded flap is a good way to repair large area of scar on extremities. Bilateral skin of scar is the first choice of donor site of expanded flap. If there isn't enough skin for expanding on bilateral sides, expanded perforator flap designed at upper or lower part of the scar is another choice to repair the scar.

Abstract P4-01-11: Diagnostic performance of supplemental screening with molecular breast imaging in women with dense breast tissue

Purpose: The aim of this study was to retrospectively assess the diagnostic performance of molecular breast imaging (MBI) as a supplementary screening tool for women with dense breast tissue. We had previously reported excellent cancer detection rates and positive predictive values, whereas in this report we present 1-year follow up data and present sensitivity, specificity and negative predictive values. Methods: Molecular Breast Imaging (MBI) was implemented in routine clinical practice at a large, community-based breast imaging center. Women 25 to 90 years of age with dense breasts and negative mammogram results who underwent subsequent screening with 300 MBq (8 mCi) 99mTc-sestamibi MBI were retrospectively analyzed. Outcome measures included sensitivity, specificity, and positive and negative predictive values. Results: In 1,376 women with a complete reference standard, 17 (1.2%) were diagnosed with cancer. MBI detected cancer in 15 subjects such that 2 interval cancers occurred and were considered false negatives. Of those 17 cancers, 1 (5.9%) were ductal carcinoma in situ only, 13 were invasive tumors (76.5%); 1 (5.9%) patient was diagnosed with bilateral disease. Overall sensitivity of MBI in this sample was 88.2% (95% CI 63.6 – 98.5), while specificity was also high at 92.4% (95% CI 90.9 – 93.8). Positive predictive value for recall (PPV1) was 12.7% (95% CI 7.3 – 20.1), while negative predictive value for recall (NPV1) was calculated as 99.8% (95% CI 99.4 – 100.0). Conclusions: When incorporated into a community-based clinical practice environment, MBI demonstrated high sensitivity, specificity and negative predictive value. These results demonstrate the utility of MBI as a supplementary screening tool to mammography for women with dense breasts.

Citation Format: Redfern RE, Shermis RB, Chen JT, Kudrolli H. Diagnostic performance of supplemental screening with molecular breast imaging in women with dense breast tissue [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-01-11.

Computation of scattering of a plane wave from multiple prolate spheroids using the collocation multipole method

The collocation multipole method is presented to solve three-dimensional acoustic scattering problems with multiple prolate spheroids subjected to a plane sound wave. To satisfy the three-dimensional Helmholtz equation in prolate spheroidal coordinates and the radiation condition at infinity, the scattered field is formulated in terms of radial and angular prolate spheroidal wave functions. Instead of using the complicated addition theorem of prolate spheroidal wave functions, the multipole method, the directional derivative, and the collocation technique are combined to solve multiple scattering problems semi-analytically. For the sound-hard or Neumann conditions, the normal derivative of the acoustic pressure with respect to a non-local prolate spheroidal coordinate system is developed without any truncation error for multiply connected domain problems. By truncating the higher order terms of the multipole expansion, a finite linear algebraic system is obtained and the scattered field is determined from the given incident acoustic wave. Once the total field is calculated as the sum of the incident field and the scattered field, the near field acoustic pressure and the far field scattering pattern are determined. Numerical experiments for convergence are performed to provide the guide lines for the proposed method. The proposed results of acoustic scattering by one, two, and three prolate spheroids are compared with those of an available analytical method and the boundary element method to validate the proposed method. Finally, the effects of the eccentricity of a prolate spheroidal scatterer, the separation between scatterers and the incident wave number on the near-field acoustic pressure and the far-field scattering pattern are investigated.

Potential role of heat-shock proteins in giant cell tumors

We investigated the differential expression protein profile of giant cell tumors (GCTs), which can be used to monitor the tumor's recurrence and metastasis, to provide preliminary results for further study. We also explored heat-shock protein (HSP) inhibitor that prevents tumors from recurring and migrating. A stable isotope-labeling strategy using isobaric tags for relative and absolute quantitation coupled with two-dimensional liquid chromatography tandem mass spectrometry was used to separate and identify differentially expressed proteins. A total of 467 differentially expressed proteins were identified in GCT tissues. Up to 311 proteins were upregulated, whereas 156 proteins were downregulated in GCT tissues. Three of the differentially expressed HSPs, namely HP90A, HSPB1, and HSPB2, were upregulated. The differentially expressed proteins of GCT tissues will provide a scientific foundation for tumor prognosis, and for further studies exploring HSP inhibitor to prevent tumor recurrence and migration.

Nonadverse effects on allergenicity of isopentenyltransferase-transformed broccoli

BACKGROUND

Genetically modified organisms (GMOs) provide modern agriculture with improvements in efficiency and the benefits of enhanced food production; however, the potential impact of GMOs on human health has not yet been clarified.

OBJECTIVE

To investigate the allergenicity of isopentenyltransferase (ipt)-transformed broccoli compared with non-GM broccoli.

METHODS

Sera from allergic individuals were used to identify the allergenicity of GM and non-GM broccoli. Immunoglobulin (Ig) binding of different lines of GM and non-GM broccoli was identified using immunoblotting, enzyme-linked immunosorbent assay, and the histamin release assay.

RESULTS

Positive reactions to broccoli (Brassica Oleracea) were observed in 7.02% of individuals. Specific IgE to broccoli and total IgE fro allergic individuals were well correlated. The different tests performed showed no significant differences in the allergenicity of conventionally raised and GM broccoli, indicating the absence of unexpected effects on allergenicity in ipt-transformed plants. Using Western blot analysis we detected heterogeneous IgE-reactive allergenic components in broccoli-allergic sera, but no significant differences between GM an non-GM broccoli were observed in serum from the same patients.

CONCLUSIONS

Our study demonstrates that there are no differences between GM (ipt-transformed) broccoli and non-GM broccoli, as determined by specific IgE in sera from broccoli-allergic patients. This indicates that there were no unexpected effects on allergenicity in this GM broccoli.

EMG-guided salpingopharyngeus Botox injection for palatal myoclonus

Palatal myoclonus (PM) is a rare neurological disorder characterized by involuntary movements of the soft palate musculature causing objective clicking tinnitus. Two forms are recognized as distinct clinical entities, with poorly understood pathogenesis: essential and symptomatic PM. The intrusive nature of the tinnitus prompts patients to seek medical advice. Conventional medical treatments with anxiolytics, antidepressants, and anticonvulsants have limited efficacy in these patients. In this case report, electromyography-guided injection of botulinum toxin type A (Botox; Allergan, Irvine, CA, USA) to the involved salpingopharyngeus and tensor veli palatini yielded satisfactory results with minimal temporary adverse effects.

Intracellular oxidative stress and cadmium ions release induce cytotoxicity of unmodified cadmium sulfide quantum dots

OBJECTIVE

To fully understand the cytotoxicity of after-degradation QDs, we synthesized CdS QDs and investigated its toxicity mechanism.

METHODS

Biomimetic method was proposed to synthesize cadmium sulfide (CdS) QDs. Thereafter MTT (3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyl tetrazolium bromide) assay was conducted to evaluate their cytotoxicity. To investigate the toxicity mechanism, we subsequently conducted intracellular reactive oxygen species (ROS) measurement with DCFH-DA, glutathione (GSH) measurement with DTNB, and cellular cadmium assay using atomic absorption spectrometer. Microsized CdS were simultaneously tested as a comparison.

RESULTS

MTT assay results indicated that CdS QDs are more toxic than microsized CdS especially at concentrations below 40 microg/ml. While microsized CdS did not trigger ROS elevation, CdS QDs increase ROS by 20-30% over control levels. However, they both deplete cellular GSH significantly at the medium concentration of 20 microg/ml. In the presence of NAC, cells are partially protected from CdS QDs, but not from microsized particles. Additionally, nearly 20% of cadmium was released from CdS nanoparticles within 24h, which also accounts for QDs' toxicity.

CONCLUSION

Intracellular ROS production, GSH depletion, and cadmium ions (Cd(2+)) release are possible mechanisms for CdS QDs' cytotoxicity. We also suggested that with QD concentration increasing, the principal toxicity mechanism changes from intracellular oxidative stress to Cd(2+) release.

Nanoparticles and 3D sponge-like porous networks of manganese oxides and their microwave absorption properties

Hydrohausmannite nanoparticles (approximately 10 nm) were prepared by the hydrothermal method at 100 degrees C for 72 h. Subsequent annealing was done in air at 400 degrees C and 800 degrees C for 10 h, Mn(3)O(4) nanoparticles (approximately 25 nm) and 3D Mn(2)O(3) porous networks were obtained, respectively. The products were characterized by XRD, TEM, SAED and FESEM. Time-dependent experiments were carried out to exhibit the formation process of the Mn(2)O(3) networks. Their microwave absorption properties were investigated by mixing the product and paraffin wax with 50 vol%. The Mn(3)O(4) nanoparticles possess excellent microwave absorbing properties with the minimum reflection loss of -27.1 dB at 3.1 GHz. In contrast, the Mn(2)O(3) networks show the weakest absorption of all samples. The absorption becomes weaker with the annealing time increasing at 800 degrees C. The attenuation of microwave can be attributed to dielectric loss and their absorption mechanism was discussed in detail.

Epitaxial Growth of InN Films by Molecular-Beam Epitaxy Using Hydrazoic Acid (HN3) as an Efficient Nitrogen Source

Epitaxial InN films have been successfully grown on c-plane GaN template by gas-source molecular-beam epitaxy with hydrazoic acid (HN3) as an efficient nitrogen source. Results in residual-gas analyzer show that the HN3 is highly dissociated to produce nitrogen radicals and can be controlled in the amounts of active nitrogen species by tuning HN3 pressure. A flat and high-purity InN epifilm has been realized at the temperature near 550 degrees C, and a growth rate of 200 nm/hr is also achieved. Moreover, the epitaxial relationship of the InN(002) on the GaN(002) is reflected in the X-ray diffraction, and the full-width at half-maximum of the InN(002) peak as narrow as 0.05 degrees is related to a high-quality crystallinity. An infrared photoluminescence (PL) emission peak at 0.705 eV and the integrated intensity increasing linearly with excitation power suggest that the observed PL can be attributed to a free-to-bound recombination.

Voxel-based analysis of the evolution of magnetization transfer ratio to quantify remyelination and demyelination with histopathological validation in a multiple sclerosis lesion

We present a new method for advanced image processing to separately quantify significant decreases and increases in the magnetization transfer ratio (MTR) of individual voxels of MS lesions as markers of demyelination and remyelination. We used this method to analyze the evolution of MTR in individual voxels of an acute, Gadolinium (Gd)-enhancing lesion that was available for pathology. Over 6.5 months following enhancement, MTR was low and stable in the lesion center (81% of the initially Gd-enhancing lesion volume (GdLV)) and MTR increased at the lesion border with normal-appearing white matter (14%GdLV). The estimated error of these measurements was less than 1.8%GdLV based on scan/rescan analysis. Histopathological analysis confirmed a demyelinated lesion centre with diffuse presence of macrophages/microglia and marked loss of oligodendrocytes and a partially remyelinated lesion border with diffuse presence of macrophages/microglia and relatively more oligodendrocytes compared to the lesion centre. The correlation of imaging and histopathological findings support the validity and sensitivity of our method of voxel-based MTR image processing for monitoring demyelination and remyelination in vivo.

Multiple sclerosis conference synopsis and discussion: cellular therapy for treatment of autoimmune diseases (October 2005)

At a conference held in October 2005, participants presented studies on high dose immunosuppression with hematopoietic cell transplant (HCT) for multiple sclerosis (MS), including neuroimmunological and magnetic resonance imaging (MRI) mechanistic approaches, clinical registry reports, and ongoing or newly-designed protocols. A discussion panel considered questions on how to define success, timing of controlled clinical trials, difficulty in patient recruitment, and future direction of high dose therapy.

The relation of focal white matter signal abnormality and focal volume loss in multiple sclerosis

There were two aims to this study. First, to explore how the reduction in the volume of abnormal T2-signal intensity associated with white matter (WM) lesions in multiple sclerosis (MS) relates to tissue loss resulting from focal pathology inside lesions. Second, to demonstrate that this volume of abnormal T2-signal intensity underestimates the actual size of the region to which the direct effects of lesion activity extend. For these purposes, we used deformation field analysis to quantify the evolution of local atrophy associated with a chronic peri-ventricular lesion in a patient with secondary progressive MS. This subject had particular features that may not necessarily co-exist in a group of unselected patients, which enabled interesting observations to be made. We show, quantitatively, that the focal WM lesion was associated with adjacent regional WM volume loss, which was disproportionate to concurrent diffuse atrophy in the rest of the normal appearing brain tissue, and that the loss of volume associated with the lesion was partially reciprocated by local ventricular expansion. Our observations re-emphasise the complex relationship between the change in the volume of abnormal signal intensity on magnetic resonance images and the tissue volume change directly related to lesion pathology. Multiple Sclerosis 2007; 13: 809-813. http:// msj.sagepub.com

Comparing individual- and area-based socioeconomic measures for the surveillance of health disparities: A multilevel analysis of Massachusetts births, 1989-1991

The absence of individual-level socioeconomic information in most US health surveillance data necessitates using area-based socioeconomic measures (ABSMs) to monitor health inequalities. Using the 1989-1991 birth weight data from Massachusetts, the authors compared estimates of health disparities detected with census tract- and block group-level ABSMs pertaining to poverty and education, as well as parental education, both independently and together. In separate models, adjusted for infant's sex, mother's age, and parents' race/ethnicity, worst-off categories of census tract ABSMs and parental education had a comparable birth weight deficit of approximately 70 g. Similar results were observed for low birth weight (<2,500 g), with worst-off categories of census tract ABSMs and parental education having an odds ratio of approximately 1.37 (p < 0.001). In mutually adjusted models for birth weight and low birth weight, census tract ABSMs still detected an effect estimate nearly 50% of that detected by parental education. Additionally, census tract ABSMs detected socioeconomic gradients in birth weight among births to mothers aged less than 25 years, an age group in which educational attainment is unlikely to be completed. These results suggest that aptly chosen ABSMs can be used to monitor socioeconomic inequalities in health. The risk, if any, in the absence of individual-level socioeconomic information is a conservative estimate of socioeconomic inequalities in health.

Comparing individual- and area-based socioeconomic measures for the surveillance of health disparities: A multilevel analysis of Massachusetts births, 1989-1991

The absence of individual-level socioeconomic information in most US health surveillance data necessitates using area-based socioeconomic measures (ABSMs) to monitor health inequalities. Using the 1989-1991 birth weight data from Massachusetts, the authors compared estimates of health disparities detected with census tract- and block group-level ABSMs pertaining to poverty and education, as well as parental education, both independently and together. In separate models, adjusted for infant's sex, mother's age, and parents' race/ethnicity, worst-off categories of census tract ABSMs and parental education had a comparable birth weight deficit of approximately 70 g. Similar results were observed for low birth weight (<2,500 g), with worst-off categories of census tract ABSMs and parental education having an odds ratio of approximately 1.37 (p < 0.001). In mutually adjusted models for birth weight and low birth weight, census tract ABSMs still detected an effect estimate nearly 50% of that detected by parental education. Additionally, census tract ABSMs detected socioeconomic gradients in birth weight among births to mothers aged less than 25 years, an age group in which educational attainment is unlikely to be completed. These results suggest that aptly chosen ABSMs can be used to monitor socioeconomic inequalities in health. The risk, if any, in the absence of individual-level socioeconomic information is a conservative estimate of socioeconomic inequalities in health.

Brain atrophy after immunoablation and stem cell transplantation in multiple sclerosis

The authors measured brain atrophy in nine patients undergoing immunoablation and autologous hematopoietic stem cell transplantation for multiple sclerosis. From baseline to 1 month after treatment, atrophy was 10 times faster than before treatment. A patient with non-CNS lymphoma showed comparable acute brain atrophy after analogous therapy. These observations suggest that brain atrophy after immunoablation may not be due entirely to the resolution of edema but may be related to chemotoxicity.

Lead inhibited N-methyl-D-aspartate receptor-independent long-term potentiation involved ryanodine-sensitive calcium stores in rat hippocampal area CA1

Lead exposure is known to be associated with cognitive dysfunction in children. Impairment of the induction of long-term potentiation (LTP) has been reported in area CA1 of rat hippocampus following lead exposure in vivo and in vitro. The present study was carried out to investigate whether the alterations of N-methyl-d-aspartate (NMDA) receptor-independent LTP following lead exposure involve internal calcium stores in hippocampus CA1 synapses. Monosynaptic field excitatory postsynaptic potentials in hippocampal slice area CA1 were recorded using the whole-cell patch-clamp upon acute lead treatment, and these studies were coupled with calcium imaging experiments to observe internal calcium changes in cultured hippocampal neurons. Inhibiting calcium release by ryanodine significantly reduced NMDA receptor-independent LTP, and depletion of internal calcium stores with thapsigargin blocked this form of LTP. Caffeine, an agonist of ryanodine receptors, enhanced this form of LTP. However, caffeine-enhanced NMDA receptor-independent LTP was depressed after bath application of lead. Moreover, lead further decreased ryanodine- and thapsigargin-reduced NMDA receptor-independent LTP. Calcium imaging also confirmed that lead had an effect on internal calcium release and uptake. Taken together, these results demonstrated that lead inhibited NMDA receptor-independent LTP by action on calcium release and uptake by ryanodine-sensitive stores in rat hippocampal area CA1.

Local magnetization transfer ratio signal inhomogeneity is related to subsequent change in MTR in lesions and normal-appearing white-matter of multiple sclerosis patients

Multiple sclerosis (MS) lesions show differing degrees of demyelination and remyelination. Changes in myelin content are associated with changes in magnetization transfer on MRI. Since acute inflammation and demyelination are spatially and temporally inhomogeneous, we hypothesized that local magnetic transfer ratio (MTR) heterogeneity might be predictive of subsequent changes in MTR. To test this hypothesis, we analyzed MTR images obtained in 14 subjects, at baseline and after 2 months follow-up. We segmented lesions and normal-appearing white-matter (NAWM), calculated MTR signal inhomogeneity maps at baseline and MTR lesion difference maps between baseline and follow-up. We found that regions with low MTR inhomogeneity at baseline experienced little further change in MTR on follow-up. The mean change in lesion MTR between baseline and follow-up was 0.10 +/- 3.70; in NAWM it was -0.09 +/- 2.02. We found that regions with high MTR inhomogeneity at baseline would change MTR on follow-up: (1) voxels with significantly high MTR in regions of high MTR inhomogeneity at baseline showed a mean decrease in MTR between baseline and follow-up of -2.51 +/- 4.68 in lesions and -1.41 +/- 3.00 in NAWM; (2) voxels with low MTR in regions of high MTR inhomogeneity at baseline showed a mean increase in MTR between baseline and follow-up of 2.61 +/- 6.07 in lesions. These changes in MTR were significantly different (P < 0.001). These results suggest that calculation of MTR signal inhomogeneity may provide a method for quantifying the potential for remyelination and demyelination, and thus could provide an important MRI biomarker for assessing the efficacy of therapies targeting remyelination.

CO(2) sensitivity of voltage gating and gating polarity of gapjunction channels--connexin40 and its COOH-terminus-truncated mutant

The CO(2) sensitivity of transjunctional voltage ( V(j)) gating was studied by dual voltage clamp in oocytes expressing mouse Cx40 or its COOH terminus (CT)-truncated mutant (Cx40-TR). V(j) sensitivity, determined by a standard V(j) protocol (20 mV V(j) steps, 120 mV maximal), decreased significantly with exposure to 30% CO(2). The Boltzmann values of control versus CO(2)-treated oocytes were: V(0) = 36.3 and 48.7 mV, n = 5.4 and 3.7, and G(j min) = 0.21 and 0.31, respectively. CO(2) also affected the kinetics of V(j)-dependent inactivation of junctional current ( I(j)); the time constants of two-term exponential I(j) decay, measured at V(j) = 60 mV, increased significantly with CO(2) application. Similar results were obtained with Cx40-TR, suggesting that CT does not play a role in this phenomenon. The sensitivity of Cx40 channels to 100% CO(2) was also unaffected by CT truncation. There is evidence that CO(2) decreases the V(j) sensitivity of Cx26, Cx50 and Cx37 as well, whereas it increases that of Cx45 and Cx32 channels. Since Cx40, Cx26, Cx50 and Cx37 gate at the positive side of V(j), whereas Cx45 and Cx32 gate at negative V(j), it is likely that V(j) behavior with respect to CO(2)-induced acidification varies depending on gating polarity, possibly involving the function of the postulated V(j) sensor (NH(2)-terminus).

Relating neocortical pathology to disability progression in multiple sclerosis using MRI

Cortical grey matter (cGM) develops a substantial burden of pathology in multiple sclerosis (MS). Previous cross-sectional studies have suggested a relationship between measures of cortical atrophy and disability. Our objective was to develop a method for automatically measuring the apparent cGM thickness as well as the integrity of the interface between cGM and subcortical white matter (GM/WM) both globally and regionally on T(1)-weighted MRI, and use this method in a longitudinal investigation of how these measures differed between patients with stable MS and patients with progressing disability. Measurements were made over the whole brain and for anatomically specified cortical regions, both cross-sectionally at baseline and longitudinally on two MRI scans performed on average 1 year apart. We found a higher average rate of apparent loss of cGM thickness across the whole brain in the group that progressed over the interscan interval compared to the group that remained stable (progressing = -3.13 +/- 2.88%/year, stable = 0.06 +/- 2.31%/year, P = 0.002). This difference was detected with regional measures in parietal and precentral cortex. In contrast, change in the GM/WM interface integrity did not show detectable regional differences, although the group of MS patients whose disability progressed showed a significant decrease in GM/WM interface integrity compared to the stable group (P = 0.003). Regional measures of apparent loss of cGM thickness enhance sensitivity to cortical pathological changes. A measure of integrity offers a new index of disease-associated cortical changes at the GM/WM interface. The results suggest that progression of disability in MS is associated with the progression of MRI-detectable cortical pathology.