Noninvasive Assessment of Diffuse Liver Diseases Using Vibration-Controlled Transient Elastography (VCTE)

Because of the limitations and invasive nature of liver biopsy, other noninvasive means are being tested for the evaluation of diffuse liver diseases. One of these methods is vibration-controlled transient elastography (VCTE). This chapter reviews the principle of VCTE, the examination technique, the normal range for liver stiffness values, the pathological changes that may influence liver stiffness, as well as the diagnostic performance in several diffuse liver diseases, especially chronic hepatitis C, chronic hepatitis B, nonalcoholic steatohepatitis, and alcoholic liver disease. Apart from the assessment of fibrosis stages, we will also discuss the diagnosis of cirrhosis and its complications as well as other applications of VCTE, reviewing its advantages and limitations

Noninvasive Evaluation of Fibrosis and Steatosis in Nonalcoholic Fatty Liver Disease by Elastographic Methods

An increasingly common cause of chronic liver disease in adults and children is nonalcoholic fatty liver disease (NAFLD). The diagnosis of NAFLD was traditionally based on the histopathological changes of the liver, evaluated by needle liver biopsy, an invasive method, with potential adverse effects and great inter and intraobserver variability. The noninvasive methods for the assessment of both fibrosis and steatosis in patients with NAFLD have increasingly been studied lately. Of these noninvasive methods, in this chapter, we will focus on the methods assessing the stiffness of liver parenchyma, i.e. elastographic methods, of which, the most widely used are ultrasound elastography techniques. We will discuss the principal elastographic methods of some utility in NAFLD, i.e. shear wdave elastography (SWE) (quantitative elastography), and especially transient elastography, point SWE (acoustic radiation force impulse elastography, ARFI) and two-dimensional real-time SWE (Supersonic). For each method usable in NAFLD cases, we will review the method principle, examination technique and performance in NAFLD evaluation

Cost-effectiveness of non-invasive methods for assessment and monitoring of liver fibrosis and cirrhosis in patients with chronic liver disease: systematic review and economic evaluation

BACKGROUND: Liver biopsy is the reference standard for diagnosing the extent of fibrosis in chronic liver disease; however, it is invasive, with the potential for serious complications. Alternatives to biopsy include non-invasive liver tests (NILTs); however, the cost-effectiveness of these needs to be established. OBJECTIVE: To assess the diagnostic accuracy and cost-effectiveness of NILTs in patients with chronic liver disease. DATA SOURCES: We searched various databases from 1998 to April 2012, recent conference proceedings and reference lists. METHODS: We included studies that assessed the diagnostic accuracy of NILTs using liver biopsy as the reference standard. Diagnostic studies were assessed using the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Meta-analysis was conducted using the bivariate random-effects model with correlation between sensitivity and specificity (whenever possible). Decision models were used to evaluate the cost-effectiveness of the NILTs. Expected costs were estimated using a NHS perspective and health outcomes were measured as quality-adjusted life-years (QALYs). Markov models were developed to estimate long-term costs and QALYs following testing, and antiviral treatment where indicated, for chronic hepatitis B (HBV) and chronic hepatitis C (HCV). NILTs were compared with each other, sequential testing strategies, biopsy and strategies including no testing. For alcoholic liver disease (ALD), we assessed the cost-effectiveness of NILTs in the context of potentially increasing abstinence from alcohol. Owing to a lack of data and treatments specifically for fibrosis in patients with non-alcoholic fatty liver disease (NAFLD), the analysis was limited to an incremental cost per correct diagnosis. An analysis of NILTs to identify patients with cirrhosis for increased monitoring was also conducted. RESULTS: Given a cost-effectiveness threshold of £20,000 per QALY, treating everyone with HCV without prior testing was cost-effective with an incremental cost-effectiveness ratio (ICER) of £9204. This was robust in most sensitivity analyses but sensitive to the extent of treatment benefit for patients with mild fibrosis. For HBV [hepatitis B e antigen (HBeAg)-negative)] this strategy had an ICER of £28,137, which was cost-effective only if the upper bound of the standard UK cost-effectiveness threshold range (£30,000) is acceptable. For HBeAg-positive disease, two NILTs applied sequentially (hyaluronic acid and magnetic resonance elastography) were cost-effective at a £20,000 threshold (ICER: £19,612); however, the results were highly uncertain, with several test strategies having similar expected outcomes and costs. For patients with ALD, liver biopsy was the cost-effective strategy, with an ICER of £822. LIMITATIONS: A substantial number of tests had only one study from which diagnostic accuracy was derived; therefore, there is a high risk of bias. Most NILTs did not have validated cut-offs for diagnosis of specific fibrosis stages. The findings of the ALD model were dependent on assuptions about abstinence rates assumptions and the modelling approach for NAFLD was hindered by the lack of evidence on clinically effective treatments. CONCLUSIONS: Treating everyone without NILTs is cost-effective for patients with HCV, but only for HBeAg-negative if the higher cost-effectiveness threshold is appropriate. For HBeAg-positive, two NILTs applied sequentially were cost-effective but highly uncertain. Further evidence for treatment effectiveness is required for ALD and NAFLD. STUDY REGISTRATION: This study is registered as PROSPERO CRD42011001561. FUNDING: The National Institute for Health Research Health Technology Assessment programme

Studies on the Mechanisms of Pollen Embryogenesis (II) : Effects of Varied Saccharide Concetrations on the Plantlet Formation in Tobacco Anther Culture

1) 葯培養における花粉起源幼植物体の形成に対する糖類の効果を明らかにするために糖の種類及び濃度を変えた培地でタバコ(Nicotiana tabacum L. cv. Bright Yellow, 2n=48)の葯を培養し, 幼植物体の形成を調査した。すなわち, 幼植物体を形成した葯の全培養葯に対する割合を植物体形成率とし, 1葯から形成された植物体数の平均を葯当り形成植物体数とした。さらにこの両者をかけ合わせた値, すなわち, 培養葯1個から期待される植物体数を葯の植物体生産能力として算定した。2) 蔗糖濃度については1/256Mから1/4Mで植物体の形成がみられ, 0M及び1/2Mでは全く認められなかった。植物体形成率については1/8Mが, 葯当り形成植物体数及び葯の植物体生産能力については1/16Mがそれぞれ最適濃度であった。また, 形成された植物体は低濃度区と高濃度区とでその形態が異なる傾向がみられた。3) ブドウ糖及び果糖についても蔗糖と同様に, 1/64Mから1/4Mまで植物体の形成がみられた。いずれの糖も植物体形成率については1/8Mの濃度が, 葯の植物体生産能力については, 1/16Mの濃度がそれぞれ最適であった。1/2Mではいずれの糖の場合も植物体形成がみられなかったので, 糖類濃度の上限が1/4Mから1/2Mの間にあるものと推察される。ブドウ糖は蔗糖とほぼ同等の効果を示したが, 果糖はやや効果が低く, 有効な濃度範囲も狭かった。 / Anthers of tobacco plants (Nicotiana tabacum L. cv. Bright Yellow, 2n=48) were cultured on agar media containing different kinds of saccharides in varied concentrations to elucidate the effects of saccharides on the plantlet formation. A summary of the results obtained is given in the following. 1) The plantlet formation was found in anther cultures on media with sucrose in concentrations varying from 1/256 to 1/4M, but not in those not only on media containing no sucrose but also on media containing it in 1/2M. The most favorable sucrose concentration was 1/8M for 'anther response', which denotes the occurrence frequency of anthers from which plantlets emerged, and 1/16M for 'expected productivity', which denotes the expected number of plantlets emerging from one anther. Morphological differences were observed between relatively low (1/256M, 1/128M, 1/64M and 1/32M) and high (1/8M and 1/4M) sucrose concentrations. 2) In glucose and fructose, the plantlet formation was found in anther cultures on media with these saccharides in concentrations varying from 1/64 to 1/4M, but not on media containing them in 1/2M. The most favorable concentration was 1/8M for 'anther response' and 1/16M for 'expected productivity'. In their effects on the plantlet formation, glucose was similar to sucrose, but fructose was of lower order and had narrower range of effectiveness than the former two saccharides

Ultrasonographic assessment of the cutaneous changes induced by topical flavonoid therapy

Ultrasonography allows the quantification of dermal density and echogenicity changes during the physiological senescence process. Some active ingredients are able to slow down the tissular degeneration and disorganization process. The purpose of this study was to assess the cutaneous changes induced by the topical use of products containing Viniferol® as active ingredient, using high-frequency ultrasound. The study was performed over 12 weeks and included 80 healthy Caucasian female subjects, aged 22–75 years, divided into two groups: the study group and the control group. The product was applied according to a predetermined protocol. The measurements performed for each subject were: the thickness of the epidermis and dermis (mm), the number of low, medium, and high echogenic pixels, and the number of low echogenic pixels in the upper dermis/number of low echogenic pixels in the lower dermis. All the parameters showed a significant improvement. Ultrasound measurements showed an increase of the mean thickness of the epidermis (P < 0.0001) and dermis (P < 0.0001) following the application of the Viniferol product as compared to the control group. The changes in the dermal echogenicity confirm the efficacy and direct action of Viniferol upon the cutaneous fibroblasts. No side effects related to the treatment were recorded. The study proves the efficacy of this active ingredient in the cutaneous senescence process as well, as the fact that anti-aging prophylaxis should be initiated in the 20–40 year critical age group. This interval involves specific changes in dermal echogenicity that quantify intense molecular, biochemical and structural changes, being thus mostly and highly responsive to the anti-aging therapy

Abdominal Tumor Characterization and Recognition Using Superior-Order Cooccurrence Matrices, Based on Ultrasound Images

The noninvasive diagnosis of the malignant tumors is an important issue in research nowadays. Our purpose is to elaborate computerized, texture-based methods for performing computer-aided characterization and automatic diagnosis of these tumors, using only the information from ultrasound images. In this paper, we considered some of the most frequent abdominal malignant tumors: the hepatocellular carcinoma and the colonic tumors. We compared these structures with the benign tumors and with other visually similar diseases. Besides the textural features that proved in our previous research to be useful in the characterization and recognition of the malignant tumors, we improved our method by using the grey level cooccurrence matrix and the edge orientation cooccurrence matrix of superior order. As resulted from our experiments, the new textural features increased the malignant tumor classification performance, also revealing visual and physical properties of these structures that emphasized the complex, chaotic structure of the corresponding tissue