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PubMed2005

Tumorigenic heterogeneity in cancer stem cells evolved from long-term cultures of telomerase-immortalized human mesenchymal stem cells.

Long-term cultures of telomerase-transduced adult human mesenchymal stem cells (hMSC) may evolve spontaneous genetic changes leading to tumorigenicity in immunodeficient mice (e.g., hMSC-TERT20). We wished to clarify whether this unusual phenotype reflected a rare but dominant subpopulation or if the stem cell origin allowed most cells to behave as cancer stem cells. Cultures of the hMSC-TERT20 strain at population doubling 440 were highly clonogenic (94%). From 110 single-cell clones expanded by 20 population doublings, 6 underwent detailed comparison. Like the parental population, each clone had approximately 1.2 days doubling time with loss of contact inhibition. All retained 1,25-(OH)(2) vitamin D(3)-induced expression of osteoblastic markers: collagen type I, alkaline phosphatase, and osteocalcin. All shared INK4a/ARF gene locus deletion and epigenetic silencing of the DBCCR1 tumor suppressor gene. Despite in vitro commonality, only four of six clones shared the growth kinetics and 100% tumorigenicity of the parental population. In contrast, one clone consistently formed latent tumors and the other established tumors with only 30% penetrance. Changing the in vitro microenvironment to mimic in vivo growth aspects revealed concordant clonal heterogeneity. Latent tumor growth correlated with extracellular matrix entrapment of multicellular spheroids and high procollagen type III expression. Poor tumorigenicity correlated with in vitro serum dependence and high p27(Kip1) expression. Aggressive tumorigenicity correlated with good viability plus capillary morphogenesis on serum starvation and high cyclin D1 expression. Thus, hMSC-TERT20 clones represent cancer stem cells with hierarchical tumorigenicity, providing new models to explore the stem cell hypothesis for cancer.

Adult↗

PubMed2001

Comparison of deposits of versican, biglycan and decorin in saphenous vein and internal thoracic, radial and coronary arteries: correlation to patency.

BACKGROUND: Matrix proteoglycans versican, biglycan and decorin are important determinants of vessel-wall structure and pathology. Thickened myxoid intimas typical of restenosis and early atherosclerosis are enriched in versican and biglycan, proteoglycans that promote proliferation and migration of smooth muscle cells and bind lipoproteins. In contrast, compact fibrous intimas are characterized by decorin. OBJECTIVE: To compare the distribution patterns of these matrix proteoglycans, and changes induced by organ culture in coronary artery, saphenous vein, internal thoracic artery (ITA), and radial artery, and correlate differences to patency. METHODS: Vessels were collected at the time of bypass surgery and heart transplantation and either fixed for immunohistochemistry or prepared for organ culture. Vessels in culture were labelled with [3H]-glucosamine and processed for autoradiography and immunohistochemistry. Distribution patterns for proteoglycans and radio-labelling were determined morphometrically. RESULTS: Distribution profiles in coronary artery and saphenous vein were similar, with relatively high levels of subendothelial versican and biglycan and low levels of decorin. In culture subendothelial incorporation of [3H]-glucosamine and immunostaining for versican and biglycan, but not decorin, were significantly increased. In contrast, the thin intima of the ITA was relatively enriched in decorin compared with the medial layers and in culture intimal staining for decorin increased markedly compared with a modest increase for biglycan and no change for versican. There was an even distribution in radial artery of all three proteoglycans across the intima without subendothelial accumulations. In culture there was an increase in staining intensity for proteoglycans of the radial artery. Neither the ITA nor radial artery exhibited an increase in subendothelial incorporation of [3H]-glucosamine in culture. CONCLUSIONS: The distributions of proteoglycans, and responses to culture correlate to the known differences in patency between grafted saphenous vein and ITA and predict that the radial artery will outperform the saphenous vein but might not be as good as the ITA for long-term patency.

Adult↗

PubMed2002

Amniotic fluid matrix metalloproteinase-9 and interleukin-6 in predicting intra-amniotic infection.

OBJECTIVE: To assess the potential role of amniotic fluid (AF) matrix metalloproteinase-9 and interleukin-6 in predicting intra-amniotic infection. METHODS: Eighty-four women with singleton gestations with preterm contraction, preterm labor, preterm premature rupture of membranes, or clinical suspicion of intra-amniotic infection were studied. Amniotic fluid was obtained by transabdominal amniocentesis before starting any treatment. Intra-amniotic infection was defined as the presence of a positive AF culture. Amniotic fluid glucose concentration, leukocytes, matrix metalloproteinase-9, and interleukin-6 were determined. RESULTS: Amniotic fluid matrix metalloproteinase-9 and interleukin-6 levels were significantly higher in women with intra-amniotic infection than in those without. With intra-amniotic infection, levels of matrix metalloproteinase-9 significantly correlated with interleukin-6 (r = 0.813, P <.001). Each of matrix metalloproteinase-9 and interleukin-6 significantly correlated with AF leukocytes and inversely correlated with AF glucose. Using AF cutoff levels of 13.6 ng/mL for matrix metalloproteinase-9 and 11.4 ng/mL for interleukin-6, the sensitivity, specificity, and positive and negative predictive values for diagnosing intra-amniotic infection were 77% versus 73%, 100% versus 79%, 100% versus 61%, and 90% versus 86%, respectively. Combining AF matrix metalloproteinase-9 with interleukin-6 slightly improved the sensitivity and the negative predictive values in diagnosing intra-amniotic infection. CONCLUSIONS: Amniotic fluid matrix metalloproteinase-9 and interleukin-6 are significantly elevated in women with intra-amniotic infection. Amniotic fluid matrix metalloproteinase-9 is an accurate biochemical marker in predicting intra-amniotic infection with better sensitivity, specificity, and positive and negative predictive values than interleukin-6.

Adolescent↗

PubMed2005

Relationship of chondrocyte apoptosis to matrix degradation and swelling potential of osteoarthritic cartilage.

BACKGROUND AND PURPOSE: Softening of cartilage is the initial degenerative step of osteoarthritic cartilage by matrix degradation and corruption of interconnection of the collagen fibrillar network. The purpose of this study was to investigate the correlation of chondrocyte apoptosis, matrix degradation, and the corruption of collagen architecture in the development of severe swelling of osteoarthritic cartilage. METHODS: Twenty osteoarthritic and 7 normal femoral neck fractured cartilage samples were obtained from patients with knee osteoarthritis and normal patients with femoral neck fracture at the time of total hip joint replacement surgery. Apoptosis was verified by TUNEL (terminal deoxynucleotidyl transferase-mediated deoxyuridine 5-triphosphate nick end-labeling) staining and structural changes were observed under phase-contrast microscopy. Matrix degradation was evaluated by histochemical analysis of proteoglycans. Swelling tests were performed by immersing the cartilage slices in hypotonic solution. The results of ultrastructural study of collagen architecture of osteoarthritic cartilage performed by scanning electron microscopy before and after swelling were compared. RESULTS: Matrix degradation was most prominent in the middle zone of osteoarthritic cartilage. The percentage of chondrocytes in osteoarthritic cartilage showing apoptosis ranged from 15 to 20% (average, 18%; standard deviation (SD) = 3.2%) and was correlated with the extent of structural changes and matrix degradation. The swelling strain of the osteoarthritic cartilage varied from 120 to 200% (average, 160%; SD = 40%) depending on the degree of matrix degradation and structural changes. The loss of interconnectivity of collagen fibrillar architecture was correlated with the increased swelling potential of osteoarthritic cartilage. CONCLUSION: This study demonstrated that chondrocyte apoptosis was correlated with matrix degradation and the corruption of fibrillar architecture and that the extent of these manifestations correlated with the swelling potential of osteoarthritic cartilage. These findings also emphasize the importance of the fibrillar architecture in maintaining the mechanical properties of cartilage.

Aged↗

PubMed2002

Apodization effects in the retrieval of volume mixing ratio profiles.

In remote sensing applications, spectra measured by Fourier-transform spectrometers are routinely apodized. A rigorous analysis approach would explicitly account for correlations induced in the covariance matrix by apodization, but these correlations are often ignored to simplify and speed up the processing. Using spectra measured by the Atmospheric Trace Molecule Spectroscopy missions, we investigated the effect of apodization on the retrieval of volume mixing ratio profiles for the case in which these correlations are ignored. Minor discrepancies occur between results for apodized and unapodized spectra, particularly when lines with a low signal-to-noise ratio are fitted. A set of microwindows is reported for O3 in the range of 1550-3350 cm(-1).

Journal Article↗

PubMed2003

Dykellic acid inhibits phorbol myristate acetate-induced matrix metalloproteinase-9 expression by inhibiting nuclear factor kappa B transcriptional activity.

Proteolytic degradation of the extracellular matrix and tumor metastasis correlate with expression of endopeptidases known as matrix metalloproteinases (MMPs). Expression of MMPs is regulated by cytokines and signal transduction pathways, including those activated by phorbol myristate acetate. We found that dykellic acid, a fungal metabolite, significantly inhibits the phorbol myristate acetate-induced increase in MMP-9 expression and activity. These effects of dykellic acid are time- and dose-dependent, and correlate with decreased MMP-9 promoter activity and mRNA expression. Whereas this compound does not affect DNA binding activity of nuclear factor kappa B (NF kappa B), dykellic acid does inhibit transactivation of NF kappa B. These data demonstrate a role for NF kappa B in the regulation of MMP-9 expression and the ability of dykellic acid to suppress this action of NF kappa B.

Enzyme Induction↗

PubMed2000

Serum matrix metalloproteinase 3 in early rheumatoid arthritis is correlated with disease activity and radiological progression.

OBJECTIVE: To analyze the clinical significance of serial measurements of serum matrix metalloproteinase 3 (MMP-3) levels in relation to markers of disease activity and radiological progression in early rheumatoid arthritis (RA). METHODS: In a 3 year prospective study of 33 patients with early RA (symptoms < 1 year at entry) monthly measurements of serum MMP-3 were transformed into time integrated values for 6 month periods for comparison with other markers of disease activity like swollen joint count (SJC), tender joint count (TJC), Ritchie articular index (RAI), the disease activity score (DAS), erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and radiological progression, scored according to Sharp's method, in which erosions and joint space narrowing are scored separately and combined to a total Sharp score. RESULTS: Significant correlations were found between serum MMP-3 and SJC, ESR, and CRP during all periods and between 6 and 30 months with the DAS. There were no correlations between serum MMP-3 and TJC or the RAI. During the first 12 months serum MMP-3 was correlated only with the item joint space narrowing of the Sharp score. After 12 months of followup it was also correlated with the total Sharp score and after 18 months it was correlated with all 3 items of the Sharp score. There was a wide interindividual variation in the relation between serum MMP-3 and radiological progression but intraindividually this relation seemed to be rather constant. CONCLUSION: Time integrated values of serum MMP-3 are correlated with time integrated values of other markers of disease activity such as joint swelling, ESR, CRP, and the DAS. Of the radiological scores, as outcome measures, especially joint space narrowing correlated closely with cumulative serum MMP-3.

Adolescent↗

PubMed2006

Effect of initial fMRI data modeling on the connectivity reported between brain areas.

Nearly all neuroimaging data analysis rests upon some form of variance partitioning. Conventional analyses, with a general linear model (GLM), partition the variance in the measured response variable into partitions described by a design matrix of explanatory variables. This approach can also be adopted in the initial modeling of the data in studies using data-led methods to summarize functional connectivity, such as principle component analysis, or studies of effective connectivity, using for example structural equation modeling. The point made in this technical note is that the partition of the original time series has to be precisely described to qualify the sources of variations that are taken into account. For conventional analyses using the GLM, the partition investigated corresponds to the subspaces of the design matrix that are tested. However, in the analyses of functional and effective connectivity, the particular subspaces considered are not always specified explicitly. Here we show that selecting different subspaces, or variance partitions, can have a profound effect, both qualitatively and quantitatively, on the sample covariances and the ensuing inferences about connectivity. We will illustrate this using simulated data that include condition and block-related effects and their interactions. We will use these three subspaces to show how the correlation between two voxels depends on which sub-partitions are examined. We will also show how the partition of the design matrix influences the resulting correlation matrix observed when studying correlations between error terms. We will finally demonstrate, quantitatively, the effect of the variance partitions considered on the correlations between two regions using a real fMRI study of biological motion.

Brain↗

PubMed2006

Induction of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs correlates with outcome of acute experimental pseudomonal keratitis.

This study aimed to investigate expressions and sources of matrix metalloproteinases (MMP)-2 and MMP-9, and of tissue inhibitors of MMP (TIMP)-1 and TIMP-2 in experimental Pseudomonas aeruginosa keratitis in rabbits. Pseudomonal keratitis was induced in New Zealand white rabbits, and macroscopic and microscopic examinations were performed at appropriate time points (3, 9, 12, 18, 24, 72 h). Expressions and sources of MMP-2, 9, and TIMP-1, 2 were determined using immunohistochemistry, gelatin zymography, ELISA, and RT-PCR. A typical corneal ulcer with a ring abscess was observed 12-72 h post-infection (p.i.) with P. aeruginosa. In microscopic examinations, massive inflammatory cell (mostly polymorphonuclear leukocytes, PMNs) infiltration and liquefactive necrosis were characteristic features. MMP-2 was constitutively expressed in keratocytes, and its expression was not apparently enhanced after pseudomonal infection as evidenced by zymography, immunostaining, and RT-PCR. However, MMP-9 and its activated form were induced, and were significantly enhanced 12-24 h p.i. MMP-9 appeared to derive from PMNs rather than from resident corneal cells. TIMP-1 was expressed in PMNs, macrophages, and keratocytes, and its expression was enhanced 72 h p.i. Although TIMP-2 was constitutively expressed as seen by immunostaining and RT-PCR, its concentration was below detection limits during the experiments. We demonstrated that MMP-9 was one of the important factors for corneal tissue destruction, because it was induced and significantly expressed in keratocytes and inflammatory cells after pseudomonal infection. Although TIMP-1 was expressed in later stages of infection, enhancement and activation of MMP-9 were much faster and stronger than those of TIMP-1, thereby facilitating tissue destruction leading to corneal ulceration.

Acute Disease↗

PubMed1997

Release of apoptogenic proteins from the mitochondrial intermembrane space during the mitochondrial permeability transition.

The Bcl-2-sensitive release of proteins such as cytochrome c from the mitochondrial intermembrane space into the cytosol is a critical early event in apoptosis. The mitochondrial permeability transition is also an important event in many forms of apoptotic cell death. To determine whether the permeability transition led to the release of apoptogenic proteins from mitochondria we induced the permeability transition in isolated rat liver mitochondria and characterised the proteins which were released. The permeability transition led to a generalised, non-specific release of proteins, including cytochrome c, from the mitochondrial intermembrane space which was prevented by an inhibitor of the permeability transition. To determine the mechanism of this protein release we measured both mitochondrial matrix swelling and protein release during the permeability transition in media of different osmolarities. Protein release correlated with mitochondrial matrix swelling, therefore the permeability transition causes release of proteins from the intermembrane space by rupturing the mitochondrial outer membrane. Supporting an apoptotic role for the proteins released by this mechanism, supernatants from mitochondria undergoing the permeability transition caused apoptotic changes in isolated nuclei. These data support the proposal that the mitochondrial permeability transition can induce apoptosis by releasing apoptogenic proteins into the cytoplasm [Skulachev, V.P., FEBS Lett. 397 (1996) 7-10].

Animals↗

PubMed2006

Expression of Smad1 is directly associated with mesangial matrix expansion in rat diabetic nephropathy.

Diabetic nephropathy is the leading cause of end-stage renal disease, and glomerular mesangial matrix expansion is the hallmark in diabetic nephropathy. However, the precise mechanism for the development of mesangial matrix expansion has remained unknown. The key component involved in mesangial matrix expansion is type IV collagen (Col4). Recently, we have reported that Smad1 transcriptionally regulates expression of Col4 under diabetic conditions in vitro. Here we show that this direct regulator of Col4 also plays a crucial role for mesangial matrix expansion in vivo. Streptozotocin-induced diabetic rats are the model of incipient diabetic nephropathy, and showed various levels of mesangial matrix expansion at 24 weeks. The glomerular expression of Smad1 was significantly increased in diabetic rats with more mesangial matrix expansion by Western blot and immunohistochemical analysis. Furthermore, the glomerular expression of Smad1 was closely correlated with the glomerular expression of Col4 and smooth muscle alpha actin (alpha-SMA), while albuminuria or glomerular filtration rate was not correlated with mesangial matrix expansion. We also found that urinary excretion of Smad1 was closely associated with the severity of mesangial matrix expansion. In cultured mesangial cells expression of Smad1 upregulated the transcriptional activity of key molecules in mesangial matrix expansion, such as Col4 and alpha-SMA. These data indicate the critical involvement of Smad1 in mesangial matrix expansion in the early phase of diabetic nephropathy. Our data imply that urinary Smad1 might be a representative diagnostic marker for mesangial matrix expansion in diabetic nephropathy.

Actins↗

PubMed2004

[Biological markers of osteoarthritis: data from the ECHODIAH cohort].

CORRELATIONS OF BIOLOGICAL MARKERS: Ten biological markers collected from blood or urine were analysed in the ECHODIAH cohort (patients with hip OA with a 3 Years follow up). In multivariate analysis, after adjustment for age, gender, and body mass index, some markers were found to be significantly correlated with clinical and radiological parameters. C-telopeptide of type II collagen (CTX-II) was correlated with pain, functional impairment, joint space narrowing, and subchondral sclerosis. C-reactive protein was correlated with pain. N-propeptide of type I collagen (PINP) was correlated with functional impairment, and cartilage oligomeric matrix protein (COMP) was correlated with inflammation. PREDICTIVE VALUE OF BIOLOGICAL MARKERS: High levels of urinary C-telopeptide of type II collagen (uCTX-II), a marker of cartilage degradation, and serum hyaluronic acid (sAH), a marker of synovial inflammation, were associated with higher risk of structure degeneration in osteoarthritis patients. Combined assay of these two markers could help identify patients with a higher risk of radiological progression, but many questions remain to be resolved.

Activities of Daily Living↗

PubMed2003

[Role of matrix metalloproteinases in the pathogenesis and therapy of leukemia].

The invasion and metastasis of malignant tumor cells are important factors causing the death of cancer patients. The proteolytic activity of proteinases to most of the extracellular matrix macromolecules is closely correlated with the invasion and metastasis of malignant tumor cells. Matrix metalloproteinases (MMP) are key proteinases involved in these processes. MMP is a type of Zn(2+)-depended proteinases. MMP2 and MMP9 are the unique types of proteinase that hydrolyze the bone structure of excellulary matrix (type IV collagen). So they are particularly correlated with leukemia cells infiltration and metastasis. This review aims to introduce the function of MMP and the regulation of matrix gene expression, as well as their roles in leukemia cell invasion and metastasis. A new strategy that MMP may be a therapeutic target in the treatment of leukemia is particularly introduced.

Antineoplastic Agents↗

PubMed2006

A new method to estimate relatedness from molecular markers.

Four major problems can affect the efficiency of methods developed to estimate relatedness between individuals from information of molecular markers: (i) some of them are dependent on the knowledge of the true allelic frequencies in the base population; (ii) they assume that all loci are unlinked and in Hardy-Weinberg and linkage equilibrium; (iii) pairwise methods can lead to incongruous assignations because they take into account only two individuals at a time; (iv) most are usually constructed for particular structured populations (only consider a few relationship classes, e.g. full-sibs vs. unrelated). We have developed a new approach to estimate relatedness that is free from the above limitations. The method uses a 'blind search algorithm' (actually simulated annealing) to find the genealogy that yield a co-ancestry matrix with the highest correlation with the molecular co-ancestry matrix calculated using the markers. Thus (i and ii) it makes no direct assumptions about allelic frequencies or Hardy-Weinberg and linkage equilibrium; (iii) it always provide congruent relationships, as it considers all individuals at a time; (iv) degrees of relatedness can be as complex as desired just increasing the 'depth' (i.e. number of generations) of the proposed genealogies. Computer simulations have shown that the accuracy and robustness against genotyping errors of this new approach is comparable to that of other proposed methods in those particular situations they were developed for, but it is more flexible and can cope with more complex situations.

Algorithms↗

PubMed2003

[Correlation between tumor necrosis factor alpha and matrix metalloproteinases levels in serum of patients with rheumatic arthritis].

Tumour necrosis factor alpha (TNF-alpha) and matrix metalloproteinases (MMPs) play an important role in the pathogenesis of rheumatoid arthritis (RA). The present study was conducted to investigate whether the serum level of TNF-alpha is correlated with MMPs and tissue inhibitors of metalloproteinases (TIMPs) in RA patients. Serum concentrations of TNF-alpha, interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), gelatinase B (MMP-9), TIMP-1 and TIMP-2 were measured by ELISA in 34 patients with RA. We found the TNF-alpha to correlate with MMP-1, MMP-3, MMP-9 and total measured MMPs serum concentrations (p < 0.05 for all comparisons). Furthermore, serum TNF-alpha, MMP-1 MMP-3, MMP-9 and TIMP-1 levels correlated with markers of disease activity such as the erythrocyte sedimentation rate, C reactive protein level and the number of swollen joints. No associations were observed between TNF-alpha and TIMPs serum concentrations. Our results support the concept of the regulation of the MMPs synthesis by cytokines such as TNF-alpha. We conclude that the measurement of the serum TNF-alpha, MMPs and TIMP-1 concentrations may be useful in the assessment of RA activity.

Arthritis, Rheumatoid↗

PubMed1992

Behavioural strategies, sensorial processes and hippocampal mossy fibre distribution in radial maze performance in mice.

Eight isogenic mice groups (6 inbred strains and 2 F1 hybrid generations) were tested on an eight-arm radial maze, using either a procedure of confinement (C) or a non-confinement (NC) to the central platform between trials, in order to control for the use of response strategies in learning. On the 6th day of training, the spatial surrounding was impoverished by removing the most salient visual cues of the room; thus allowing testing for the effective use of spatial cues during learning. Results showed that learning profiles and performance levels varied between strains within each procedure. These variations could correspond to a heterogeneity of the underlying perceptual processes involved in learning, since only some strains in each procedure were disturbed by the removal of spatial cues. Correlations between behavioural results and the distribution of mossy fibres in the hippocampus were analysed. The intercorrelation matrix revealed that correlations between the size of the infra-intrapyramidal synaptic field (IIP-MF) and some behavioural indices occurred only during the first trial on the maze, whatever the procedure. Learning performances on the 5th day of training did not correlate with any hippocampal measure. When the spatial surrounding was impoverished, on the 6th day of training, correlations with mossy fibres appeared only in the confinement procedure.

Animals↗

PubMed1990

Conversion of ouabain-induced ventricular tachycardia in dogs with epicardial lidocaine: pharmacodynamics and functional effects.

Epicardial antiarrhythmic drug administration was studied as a therapeutic approach for experimental ventricular tachycardia (VT) in an open-chest dog model. Lidocaine-polyurethane matrices (28%, w/w) were formulated as a model system. Matrices were placed on the left ventricular epicardium in each of 23 anesthetized open-chest dogs with ouabain-induced VT, to evaluate effectiveness in restoring sinus rhythm. Conversion occurred in all animals treated with matrices containing 300 mg or more of lidocaine after 1.5 to 7.0 min. The matrix lidocaine content correlated linearly with the time required for conversion to sinus rhythm (r = 0.75, P = 0.0002); irrespective of matrix size the myocardial/plasma lidocaine ratio was 20.1 +/- 4.2 (mean +/- SD) at the time of conversion. In a separate series of five dogs without ventricular tachycardia, systolic wall thickening measured with sonomicrometers after 5 min of controlled-release lidocaine administration (500- to 1000-mg matrix lidocaine content, 7.48 +/- 3.49-mg/kg dose) was only minimally diminished (-14.1%) and this effect was observed only at the site of matrix placement on the anterior-apical epicardium. In contrast, intracoronary injection of 0.3 or 1.0 mg/kg of lidocaine-HCl resulted in complete elimination of wall thickening or replacement by systolic thinning. Thus epicardial administration of lidocaine from polyurethane matrices was an effective means of treating ouabain-induced ventricular tachycardia. Regional myocardial function in the vicinity of the matrices was modified to a very limited degree, supporting the view that the matrices can be used safely, without serious risk to ventricular contractile performance.

Animals↗

PubMed2000

Faculty evaluation by residents in an emergency medicine program: a new evaluation instrument.

OBJECTIVE: Evaluation of preceptors in training programs is essential; however, little research has been performed in the setting of the emergency department (ED). The goal of this pilot study was to determine the validity and reliability of a faculty evaluation instrument-the Emergency Rotation (ER) scale-developed specifically for use in emergency medicine (EM). METHODS: A prospective study comparing the ER scale with two alternative faculty evaluation instruments was completed in three of the five EDs affiliated with an EM teaching program, where emergency physicians are members of the clinical teaching faculty. The participants were 18 residents (postgraduate years 1, 2, and 3) who were completing four-week clinical rotations in EM. Residents at the end of the rotation recorded their evaluations of each emergency physician with whom they had clinical encounters on the following evaluation tools: the ER scale, a longer validated scale (Irby), and a global assessment scale (GAS). Domain scores were correlated with the previously validated scale and the GAS to determine validity using a multitrait-multimethod matrix. The reliability of the ER scale was measured using a Chronbach's alpha coefficient. RESULTS: Forty-eight preceptor evaluations were completed on 29 individual preceptors. The rating of preceptors was high using the ER scale (median: 16 of 20; IQR: 13, 18), Irby (median: 300 of 378; IQR: 267, 321), or GAS (mean: 7.8 of 10; SD: 1.3). Domain scores for each tool were used in the multitrait-multimethod matrix and the correlations between a previously validated tool and the ER scale were found to be high (>0.70) in the various domains. The internal consistency of the ER scale was also high (r = 0.85). CONCLUSIONS: The ER scale appears to be valid and reliable. It performs well when compared with previously psychometrically tested tools. It is a sensible, well-adapted tool for the teaching environment offered by EM.

Alberta↗