Using a modified technology acceptance model in hospitals

Purpose

The use of information technology in the health care sector and especially in hospitals offers great potential for improving the quality of services provided and the efficiency and effectiveness of the personnel, but also for reducing the organizational expenses. However, the main question that arises according to the literature is whether hospital personnel are willing to use state of the art information technology while performing their tasks. This study attempts to address this issue by developing and testing a modified technology acceptance model taking into consideration other relevant models found in the literature.

Method

The original TAM has been extended to include some exogenous variables in order to examine HIS acceptance by Greek hospital personnel. Correlation, explanatory and confirmation factor analysis was performed to test the reliability and validity of the measurement model. The structural equation modeling technique has also been used to evaluate the causal model.

Results

The results indicate that perceived usefulness, ease of use, social influence, attitude, facilitating conditions and self-efficacy significantly affect hospital personnel behavioral intention. Training has a strong indirect impact on behavioral intention through the mediators of facilitating condition and ease of use. Furthermore, the existence of significant positive effects between self-efficacy and social influence, perceived usefulness and anxiety, and facilitating conditions and social influence is also supported.

Conclusions

The proposed model can explain 87% of the variance of behavioral intention indicating that the core constructs of the technology acceptance models have a strong and statistically significant influence on hospital personnel usage intention.     

Assessment of fibrosis and cirrhosis in liver biopsies: an update

The liver biopsy specimen represents valuable material for the assessment of fibrosis and cirrhosis. Despite limitations related to sampling and interpretation, histologic examination remains the gold standard for staging chronic liver diseases. Hepatic fibrosis is currently viewed as a dynamic process that may often regress after successful treatment of chronic liver diseases. Even the excess fibrous tissue of cirrhotic livers may sometimes regress over time. Distinguishing between the amount of hepatic fibrosis and the disease stage is important for the assessment of the effects of antifibrotic treatments. Recent studies suggest that the proportion of the liver biopsy specimen occupied by collagen is correlated with the hepatic venous pressure gradient in liver transplant recipients with hepatitis C virus infection, with or without cirrhosis, and represents a predictor of clinical decompensation. This parameter has also been found to correlate with liver stiffness measurements of patients with chronic viral hepatitis obtained by transient elastography. Therefore, quantitative assessment of hepatic fibrosis in liver biopsy specimens holds promise as a prognostic marker, and as a means to validate noninvasive markers of fibrosis.     

Expansion of toll-like receptor 9-expressing B cells in active systemic lupus erythematosus: implications for the induction and maintenance of the autoimmune process

OBJECTIVE: Toll-like receptors (TLRs) are pattern-associated receptors in innate immunity that may be involved in the recognition of self antigens and the production of pathogenic autoantibodies. This study was undertaken to examine the expression and function of various TLRs in subpopulations of peripheral blood mononuclear cells (PBMCs) of patients with systemic lupus erythematosus (SLE). METHODS: The expression of TLRs in PBMCs from 50 SLE patients with active disease (SLE Disease Activity Index [SLEDAI] score >or=8; n = 26) or inactive disease (SLEDAI score <8; n = 24) and 20 healthy controls was studied by flow cytometry. TLR expression was assessed on various subpopulations of PBMCs (TLR-2 and TLR-4 by membrane staining; TLR-3 and TLR-9 by intracellular staining). TLR function was accessed by stimulating PBMCs with specific ligands. RESULTS: The proportion of B cells and monocytes expressing TLR-9 was higher among patients with active SLE (mean +/- SD 49.5 +/- 24.4% and 30.7 +/- 24.1%, respectively) than among patients with inactive disease (22.8 +/- 19.6% and 14.3 +/- 8.4%, respectively; P = 0.02 and P = 0.03). Among B cells, the proportion of plasma cells and memory B cells expressing TLR-9 was increased in patients with active SLE. Increased percentages of TLR-9-expressing B cells correlated with the presence of anti-double-stranded DNA antibodies (P = 0.007). Treatment with serum from patients with active disease increased the percentage of TLR-9-expressing plasma cells in serum from healthy controls. Enhanced induction of HLA-DR after TLR-9 stimulation was documented in B cells from patients with active disease. CONCLUSION: In patients with active SLE, the proportion of peripheral blood memory B cells and plasma cells expressing TLR-9 is increased. Endogenous nucleic acids released during apoptotic cell death may stimulate B cells via TLR-9 and contribute to SLE pathogenesis.     

Artificial neural networks distinguish among subtypes of neoplastic colorectal lesions

BACKGROUND & AIMS: There is a subtle distinction between sporadic colorectal adenomas and cancers (SAC) and inflammatory bowel disease (IBD)-associated dysplasias and cancers. However, this distinction is clinically important because sporadic adenomas are usually managed by polypectomy alone, whereas IBD-related high-grade dysplasias mandate subtotal colectomy. The current study evaluated the ability of artificial neural networks (ANNs) based on complementary DNA (cDNA) microarray data to discriminate between these 2 types of colorectal lesions. METHODS: We hybridized cDNA microarrays, each containing 8064 cDNA clones, to RNAs derived from 39 colorectal neoplastic specimens. Hierarchical clustering was performed, and an ANN was constructed and trained on a set of 5 IBD-related dysplasia or cancer (IBDNs) and 22 SACs. RESULTS: Hierarchical clustering based on all 8064 clones failed to correctly categorize the SACs and IBDNs. However, the ANN correctly diagnosed 12 of 12 blinded samples in a test set (3 IBDNs and 9 SACs). Furthermore, using an iterative process based on the computer programs GeneFinder, Cluster, and MATLAB, we reduced the number of clones used for diagnosis from 8064 to 97. Even with this reduced clone set, the ANN retained its capacity for correct diagnosis. Moreover, cluster analysis performed with these 97 clones now separated the 2 types of lesions. CONCLUSIONS: Our results suggest that ANNs have the potential to discriminate among subtly different clinical entities, such as IBDNs and SACs, as well as to identify gene subsets having the power to make these diagnostic distinctions.     

Immunohistochemical evidence for hepatic progenitor cells in liver diseases

BACKGROUND/AIM: Proliferative bile ductular reactions occur in a variety of liver diseases in humans. It is a matter of debate whether such reactions result from progenitor cell proliferation with biliary and hepatocytic differentiation, versus biliary metaplasia of damaged hepatocytes. We investigated bile ductular reactions in liver diseases, paying particular attention to the presence of cells with intermediate (hepatocytic/biliary) features (oval-like cells). METHODS: Five specimens each were selected of submassive hepatic necrosis and cirrhosis due to hepatitis B, hepatitis C, autoimmune hepatitis, alcohol injury, primary biliary cirrhosis and primary sclerosing cholangitis. Immunohistochemical stains were performed for biliary markers (cytokeratins [CKs] 7 and 19), as well as hepatocytic markers (HepParl and alpha-fetoprotein[AFP]) in sequential sections. The degree of staining of each cell type (biliary, hepatocytic, intermediate) was graded semiquantitatively. RESULTS: Hepatocytes always stained diffusely for HepParl, occasionally for CK7, and rarely for CK19. Biliary cells were always diffusely positive for CK7 and CK19, and rarely for HepParl. Intermediate cells were identified in all cases and showed widespread staining for both HepParl and CK7, and less commonly for CK19. AFP was not expressed in any cell type. The morphologic and immunohistochemical features of bile ductular reactions were similar in the different diseases. CONCLUSIONS: Proliferating hepatic parenchymal cells with intermediate (hepatocytic/biliary) morphologic features and combined immunophenotype can be identified in a variety of acute and chronic liver diseases. The similarity of bile ductular reactions among chronic hepatitic, alcoholic and biliary diseases suggests that they result from proliferation of oval-like progenitor cells.     

Enhancement patterns and signal-intensity characteristics of small hepatocellular carcinoma in cirrhosis: pathologic basis and diagnostic challenges

Recent pathologic studies of hepatic resection and transplantation specimens have elucidated the morphologic features of the precancerous lesions and small hepatocellular carcinomas (HCCs) arising in cirrhotic livers. Small HCCs measuring less than 2 cm in diameter are of two types: vaguely nodular, well-differentiated tumors, also known as "early" HCCs, and distinctly nodular tumors, with histologic features of "classic" HCC. The precancerous lesions include dysplastic foci and dysplastic nodules. "Classic" small HCCs are supplied by nontriadal arteries, whereas early HCCs and dysplastic nodules may receive blood supply from both portal tracts and nontriadal arteries. The similarities in blood supply of these three types of nodular lesions result in significant overlap of findings on dynamic imaging. Nevertheless, small HCCs sometimes display characteristic radiologic features, such as "nodule-in-nodule" configuration and "corona enhancement" pattern. Moreover, various histologic features of these nodular lesions may also be related to a variety of signal intensities and attenuation coefficients, while the presence of cirrhosis is known to limit the sensitivity and specificity of any imaging modality, due to liver inhomogeneity. Because of these reasons, imaging findings of nodular lesions in cirrhotic livers are often inconclusive, emphasizing the need for a better understanding of these imaging features.     

Nomenclature of the finer branches of the biliary tree: canals, ductules, and ductular reactions in human livers

The work of liver stem cell biologists, largely carried out in rodent models, has now started to manifest in human investigations and applications. We can now recognize complex regenerative processes in tissue specimens that had only been suspected for decades, but we also struggle to describe what we see in human tissues in a way that takes into account the findings from the animal investigations, using a language derived from species not, in fact, so much like our own. This international group of liver pathologists and hepatologists, most of whom are actively engaged in both clinical work and scientific research, seeks to arrive at a consensus on nomenclature for normal human livers and human reactive lesions that can facilitate more rapid advancement of our field.