Multi-site reproducibility of a human immunophenotyping assay in whole blood and peripheral blood mononuclear cells preparations using CyTOF technology coupled with Maxpar Pathsetter, an automated data analysis system.

High-dimensional mass cytometry data potentially enable a comprehensive characterization of immune cells. In order to positively affect clinical trials and translational clinical research, this advanced technology needs to demonstrate a high reproducibility of results across multiple sites for both peripheral blood mononuclear cells (PBMC) and whole blood preparations. A dry 30-marker broad immunophenotyping panel and customized automated analysis software were recently engineered and are commercially available as the Fluidigm® Maxpar® Direct™ Immune Profiling Assay™.

Automated Data Cleanup for Mass Cytometry.

Mass cytometry is an emerging technology capable of 40 or more correlated measurements on a single cell. The complexity and volume of data generated by this platform have accelerated the creation of novel methods for high-dimensional data analysis and visualization. A key step in any high-level data analysis is the removal of unwanted events, a process often referred to as data cleanup.

Sometimes simpler is better: VLog, a general but easy-to-implement log-like transform for cytometry.

The fundamental purpose of log and log-like transforms for cytometry is to make measured population variabilities as uniform as possible. The long-standing success of the log transform was its ability to stabilize linearly increasing gain-dependent uncertainties and the success of the log-like transforms is that they extend this notion to include zero and negative measurement values. This study derives and examines a transform called VLog that stabilizes the three general sources of variability: (1) gain-dependent variability, (2) photo-electron counting error, and (3) signal-independent sources of error.

Probability state modeling theory.

As the technology of cytometry matures, there is mounting pressure to address two major issues with data analyses. The first issue is to develop new analysis methods for high-dimensional data that can directly reveal and quantify important characteristics associated with complex cellular biology. The other issue is to replace subjective and inaccurate gating with automated methods that objectively define subpopulations and account for population overlap due to measurement uncertainty.

Iron overload in adults with sickle cell disease who have received intermittent red blood cell transfusions.

Objective: To assess the prevalence of iron overload in adults with sickle cell disease (SCD) not on a chronic transfusion protocol.

Design: Retrospective chart review.

Data Source: University of South Alabama Comprehensive Sickle Cell Center adult outpatient clinic.

Automated analysis of flow cytometric data for CD34+ stem cell enumeration using a probability state model.

Background: Flow Cytometry is widely used for enumeration of hematopoietic stem cell (SC) levels in bone marrow, cord blood, peripheral blood, and apheresis products. The ISHAGE single-platform gating method is considered by many to be the standard for CD34+ SC enumeration. However, attempts at uniform application of this ISHAGE method have met with only partial success.

Misclassification of pulmonary hypertension in adults with sickle hemoglobinopathies using Doppler echocardiography.

Objective: To compare the diagnostic utility of Doppler echocardiography-derived tricuspid regurgitant jet velocity (TRV) ≥ 2.5 m/s to right heart catheterization (RHC) in defining pulmonary hypertension (PH) in adult patients with sickle cell disease (SCD).

Methods: This is a retrospective chart review of adults with SCD who had a TRV ≥ 2.

Severe human metapneumovirus infection in hospitalized children.

Human metapneumovirus is a recently discovered pathogen that causes upper and lower respiratory tract disease in children. This study describes the course of illness in hospitalized children with this infection. During a 6-month period, 11 children were diagnosed with human metapneumovirus infection by reverse transcription-polymerase chain reaction.

Comparison of hospital laboratory serum alcohol levels obtained by an enzymatic method with whole blood levels forensically determined by gas chromatography.

Estimating the equivalent whole blood ethanol level from a serum or plasma determination has been addressed by numerous articles in both the clinical and forensic literature. All previous studies have either involved sample sizes insufficient for adequate statistical evaluation or have utilized gas chromatography for both serum and whole blood analysis. In this study, based on samples from 212 consecutive patients admitted to a hospital trauma center, serum was assayed for ethanol using an enzymatic oxidation method, and the results were compared to whole blood samples taken simultaneously and analyzed by headspace gas chromatography in a forensic toxicology laboratory.

Physicians' attitude and practices in sickle cell disease pain management.

Many physicians believe that patients with sickle cell disease (SCD) are more likely to become addicted to pain medication than are other patient populations. This study hypothesizes that physicians' attitudes towards addiction in patients with SCD affects pain management practices. The Physician Attitudes Survey was sent to 286 physicians at seven National Institutes of Health-funded university-based comprehensive sickle cell centres.

Multiparameter flow cytometry of fluorescent protein reporters.

Reporters based on the green fluorescent protein (GFP) from the jellyfish Aequorea victoria and GFP-like proteins from other marine organisms provide valuable tools to monitor gene transfer and expression noninvasively in living cells. Stable cell lines were generated from the Sp2/0-Ag14 hybridoma that express up to three spectral enhanced versions of GFP, the enhanced cyan fluorescent protein (ECFP), the enhanced green fluorescent protein (EGFP), and the enhanced yellow fluorescent protein (EYFP), and/or a variant of the Discosoma coral red fluorescent protein (DsRed). The panel of lines was used to demonstrate a flow cytometric procedure for simultaneous analysis of all four fluorescent proteins that utilizes dual-laser excitation at 488 nm and 407 nm.

Melatonin increases survival and inhibits oxidative and amyloid pathology in a transgenic model of Alzheimer's disease.

Increased levels of a 40-42 amino-acid peptide called the amyloid beta protein (A beta) and evidence of oxidative damage are early neuropathological markers of Alzheimer's disease (AD). Previous investigations have demonstrated that melatonin is decreased during the aging process and that patients with AD have more profound reductions of this hormone. It has also been recently shown that melatonin protects neuronal cells from A beta-mediated oxidative damage and inhibits the formation of amyloid fibrils in vitro.

Are we doing any good by doing really well? (Where's the Bacon?).

Francis Bacon, who with Rene Decartes laid the intellectual foundations for Western science in the seventeenth century, asserted that the purpose of all knowledge is "action in the production of works for ...

Methodological issues in radiation dose-volume outcome analyses: summary of a joint AAPM/NIH workshop.

This report represents a summary of presentations at a joint workshop of the National Institutes of Health and the American Association of Physicists in Medicine (AAPM). Current methodological issues in dose-volume modeling are addressed here from several different perspectives. Areas of emphasis include (a) basic modeling issues including the equivalent uniform dose framework and the bootstrap method, (b) issues in the valid use of statistics, including the need for meta-analysis, (c) issues in dealing with organ deformation and its effects on treatment response, (d) evidence for volume effects for rectal complications, (e) the use of volume effect data in liver and lung as a basis for dose escalation studies, and (f) implications of uncertainties in volume effect knowledge on optimized treatment planning.