Is Going Beyond Rasch Analysis Necessary to Assess the Construct Validity of a Motor Function Scale?

Objective

To examine whether a Rasch analysis is sufficient to establish the construct validity of the Motor Function Measure (MFM) and discuss whether weighting the MFM item scores would improve the MFM construct validity.

Lower Monoamine Oxidase-A Total Distribution Volume in Impulsive and Violent Male Offenders with Antisocial Personality Disorder and High Psychopathic Traits: An [11C] Harmine Positron Emission Tomography Study

Antisocial personality disorder (ASPD) often presents with highly impulsive, violent behavior, and pathological changes in the orbitofrontal cortex (OFC) and ventral striatum (VS) are implicated. Several compelling reasons support a relationship between low monoamine oxidase-A (MAO-A), an enzyme that regulates neurotransmitters, and ASPD. These include MAO-A knockout models in rodents evidencing impulsive aggression and positron emission tomography (PET) studies of healthy subjects reporting associations between low brain MAO-A levels and greater impulsivity or aggression. However, a fundamental gap in the literature is that it is unknown whether brain MAO-A levels are low in more severe, clinical disorders of impulsivity, such as ASPD. To address this issue, we applied [¹¹C] harmine PET to measure MAO-A total distribution volume (MAO-A V_T), an index of MAO-A density, in 18 male ASPD participants and 18 age- and sex-matched controls. OFC and VS MAO-A V_T were lower in ASPD compared with controls (multivariate analysis of variance (MANOVA): F_2,33=6.8, P=0.003; OFC and VS MAO-A V_T each lower by 19%). Similar effects were observed in other brain regions: prefrontal cortex, anterior cingulate cortex, dorsal putamen, thalamus, hippocampus, and midbrain (MANOVA: F_7,28=2.7, P=0.029). In ASPD, VS MAO-A V_T was consistently negatively correlated with self-report and behavioral measures of impulsivity (r=−0.50 to −0.52, all P-values<0.05). This study is the first to demonstrate lower brain MAO-A levels in ASPD. Our results support an important extension of preclinical models of impulsive aggression into a human disorder marked by pathological aggression and impulsivity.     

Factors predictive of complete resection of operable esophageal cancer: review of 746 patients

OBJECTIVE: Surgery is the treatment of reference for early-stage esophageal cancer, but 5-year survival is only 20% to 25%. After complete resection (R0), survival is significantly longer than after incomplete resection, with microscopic (R1) or macroscopic (R2) penetration. The purpose of this work was to identify retrospectively the factors predictive of complete resection of operable esophageal cancers.PATIENTS AND METHODS: Between January 1982 and March 2001, 746 patients with esophageal cancer underwent curative surgery. R0 resection was performed in 585 patients (78.4%), R1 in 61 (8.2%) and R2 in 100 (13.4%). Univariate and multivariate analysis included 28 preoperative, clinical, tumor and therapeutic parameters.RESULTS: Multivariate analysis showed that factors predictive of complete resection R0 were: absence of any modification of the esophageal axis on the barium swallow (P=0.054), a partial or complete response to preoperative radio-chemotherapy (P=0.042), tumor height<10 cm (P=0.1) and tumor diameter<30 mm (P=0.01). Three groups of patients were identified from the 2 most significant variables. Group 1: no deviation of the axis on the barium swallow (n=501). Group 2: deviation of the axis on the barium swallow and partial or complete response to radiochemotherapy (n=91). Group 3: deviation of the axis on the barium swallow and no response to radiochemotherapy or no preoperative treatment (n=126). For the three groups, rate of R0 resection was 82.6%, 80.1% and 61.1% and 5-year actuarial survival 36%, 27% and 14%, respectively. These rates were significantly different between groups (P<10(- 4)) and two by two (P<0.04).CONCLUSION: Complete resection of esophageal cancer is predictable. After validation with an independent population the findings presented here could be used to establish stratification criteria for future therapeutic trials.     

Immunoaffinity Extraction and Alternative Approaches for the Analysis of Toxins in Environmental,Food or Biological Matrices

The evolution of instrumentation in terms of separation and detection allowed a real improvement of the sensitivity and analysis time. However, the analysis of ultra-traces of toxins in complex samples requires often a step of purification and even preconcentration before their chromatographic analysis. Therefore, immunoaffinity sorbents based on specific antibodies thus providing a molecular recognition mechanism appear as powerful tools for the selective extraction of a target molecule and its structural analogs to obtain more reliable and sensitive quantitative analysis in environmental, food or biological matrices. This review focuses on immunosorbents that have proven their efficiency in selectively extracting various types of toxins of various sizes (from small mycotoxins to large proteins) and physicochemical properties. Immunosorbents are now commercially available, and their use has been validated for numerous applications. The wide variety of samples to be analyzed, as well as extraction conditions and their impact on extraction yields, is discussed. In addition, their potential for purification and thus suppression of matrix effects, responsible for quantification problems especially in mass spectrometry, is presented. Due to their similar properties, molecularly imprinted polymers and aptamer-based sorbents that appear to be an interesting alternative to antibodies are also briefly addressed by comparing their potential with that of immunosorbents.