Application of magnetic resonance imaging in transgenic and chemical mouse models of hepatocellular carcinoma

<p>Abstract</p> <p>Background</p> <p>Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. The molecular mechanisms underlying hepatocarcinogenesis are still poorly understood. Genetically modified mice are powerful tools to further investigate the mechanisms of HCC development. However, this approach is limited due to the lack of non-invasive detection methods in small rodents. The aim of this study was to establish a protocol for the non-invasive analysis of hepatocarcinogenesis in transgenic mice using a clinical 1.5 Tesla Magnetic Resonance Imaging scanner.</p> <p>Results</p> <p>As a model system we used hepatocyte-specific c-myc transgenic mice developing hepatocellular carcinoma at the age of 12-15 months. The scans of the murine livers included axial T2-weighted turbo-spin echo (TSE) images, axial T1-weighted and contrast enhanced T1-weighted gradient echo (fast field echo, FFE) and sagittal true Fast Imaging with Steady state Precession (true-FISP) images. Application of contrast agent was performed via tail vein-catheter and confirmed by evaluation of the altered longitudinal relaxation T1 time before and after application. Through technical adaptation and optimization we could detect murine liver lesions with a minimum diameter of approximately 2 mm and provided histopathological evidence that these MR findings correspond to hepatocellular carcinoma. Tumor growth was repeatedly measured using sequential MRI with intervals of 5 weeks and subsequent volumetric analysis facilitating direct comparison of tumor progression between individual animals. We finally demonstrated that our protocol is also applicable in the widely- used chemical model of N-nitrosodiethylamine-induced hepatocarcinogenesis.</p> <p>Conclusion</p> <p>Our protocol allows the non-invasive, early detection of HCC and the subsequent continuous monitoring of liver tumorgenesis in transgenic mice thereby facilitating future investigations of transgenic tumor mouse models of the liver.</p

Kombinasi Format Factory, U-lead dan Microsoft Office Powerpoint dalam Upaya Meningkatkan Kualitas Media Pembelajaran

Peserta didik mempunyai gaya belajar yang berbeda-beda. Gaya belajar tersebut meliputi auditori, visual dan kinestetik (VAK). Seorang guru harus mampu memenuhi kebutuhan masing-masing gaya belajar peserta didik tersebut. Salah satu cara yang dapat dilakukan adalah dengan menggunakan media pembelajaran berbasis VAK. Media pembelajaran berbasis VAK dapat dipenuhi dengan menyisipkan file video di dalamnya. Selain itu, penggunaan file video sebagai media pembelajaran mendukung implementasi pembelajaran saintifik pada kurikulum 2013. Namun, belum semua guru memiliki kemampuan untuk mengemas file video tersebut dalam bentuk media pembelajaran. Tujuan penelitian ini adalah untuk meningkatkan kemampuan guru-guru di SMA Negeri 1 Teras dan SMA Negeri 1 Boyolali dalam membuat media pembelajaran berbasis VAK dengan kombinasi software Format Factory, U-Lead dan PowerPoint. Hasil penelitian menunjukkan bahwa terjadi peningkatan kemampuan para guru di SMA Negeri 1 Teras dan SMA Negeri 1 Boyolali dalam membuat media pembelajaran. Peningkatan kemampuan guru-guru tersebut berada di atas target yang direncanakan. Rerata peningkatan kemampuan guru-guru di SMA Negeri 1 Teras 7,87% di atas target, sedangkan di SMA Negeri 1 Boyolali 9,58% di atas target. Kata kunci: Media Pembelajaran, Format Factory, U-Lead, PowerPoint Students have different learning styles. Learning styles include visual learners, auditory learners, and kinesthetic learners. A teacher must be able to fulfill the needs of individual students\u27 learning styles. One way that can be applied is using Visual, Audio and Kinesthetic (VAK) learning media based. VAK-learning media based can be created by inserting video files on it. In addition, using video file as a learning media can support the implementation of scientific learning on the 2013 curriculum. However, not all teachers have the ability to use video files into a learning media. The purpose of this study is to improve the teachers\u27 ability at SMA Negeri 1 Teras and SMAN 1 Boyolali on making VAK-learning media based with a combination of Format Factory, U-Lead and PowerPoint software. The results showed that the teachers\u27 ability on making VAK-learning media based was increased. Increased the teachers\u27 ability was above planned target score. The mean score of the teachers\u27 ability at SMA Negeri 1 Teras 7.87% above the target, while at SMAN 1 Boyolali 9.58% above the target

Molecular analysis of the role of Caspase-8 during liver regeneration and tumorigenesis

Binding of the cytokine TNF-alpha to TNF-Receptor 1 mediates pleiotropic effects via two different signaling complexes. Complex-I triggers activation of NF-kappaB and activation of c-Jun N-terminal kinases (JNK) leading to inflammation and/ or cell proliferation, whereas complex-II induces apoptosis through Caspase-8. TNF signaling is crucial for the priming phase of liver regeneration following partial hepatectomy (PH) which directly contributes to gene activation of Cyclin D via NF-kappaB, c-Jun/ AP-1 and E2F1. The aim of the present study was to investigate the consequences of Caspase-8 deletion for TNF signaling during liver regeneration and termination as well as the role of Caspase-8 for initiation and development of hepatocellular carcinoma. Consequently, animals expressing Caspase-8 (f/f) on a regular level or mice deleted (delta) in Caspase-8 were generated to define the role of Caspase-8 during TNF-mediated signaling and subjected to 2/3 PH. Cessation of liver regeneration was observed in the same manner in both genotypes at equal time points clearly indicating that the function of Caspase-8 is dispensable for the process of termination. Surprisingly, animals with deleted Caspase-8 were more prone to TNF-mediated NF-kappaB and c-Jun/ AP-1 activation due to advantageous formation of complex-I subsequently leading to earlier onset of cell cycle progression. For the characterization of Casp8deltahep mice in genetic models of hepatocarcinogenesis, a standardized protocol for the application of magnetic resonance imaging (MRI) on genetically modified mice was established. Using this technique and conventional methods it was demonstrated that concomitant Caspase-8 ablation and c-myc over-expression in murine livers (Casp8deltahepalb-myctg) caused delayed tumor development but accelerated progression of HCC when compared to alb-myctg mice. These findings provide strong evidence for a protective function of Caspase-8 in hepatocellular carcinogenesis. In summary, it was demonstrated that Caspase-8 mediates not only pro-apoptotic, but also non-apoptotic functions as it contributes to the proper assembly of TNF- complex-I formation. Thus, ablation of Caspase-8 results in aberrant complex-I formation and subsequently accelerated NF-kappaB and JNK activation eventually leading to earlier Cyclin D expression and induction of cell cycle activity

Complexities of TGF-β targeted cancer therapy.

Many advanced tumors produce excessive amounts of Transforming Growth Factor-β (TGF-β) which, in normal epithelial cells, is a potent growth inhibitor. However, in oncogenically activated cells, the homeostatic action of TGF-β is often diverted along alternative pathways. Hence, TGF-β signaling elicits protective or tumor suppressive effects during the early growth-sensitive stages of tumorigenesis. However, later in tumor development when carcinoma cells become refractory to TGF-β-mediated growth inhibition, the tumor cell responds by stimulating pathways with tumor progressing effects. At late stages of malignancy, tumor progression is driven by TGF-β overload. The tumor microenvironment is a target of TGF-β action that stimulates tumor progression via pro-tumorigenic effects on vascular, immune, and fibroblastic cells. Bone is one of the richest sources of TGF-β in the body and a common site for dissemination of breast cancer metastases. Osteoclastic degradation of bone matrix, which accompanies establishment and growth of metastases, triggers further release of bone-derived TGF-β. This leads to a vicious positive feedback of tumor progression, driven by ever increasing levels of TGF-β released from both the tumor and bone matrix. It is for this reason, that pharmaceutical companies have developed therapeutic agents that block TGF-β signaling. Nonetheless, the choice of drug design and dosing strategy can affect the efficacy of TGF-β therapeutics. This review will describe pre-clinical and clinical data of four major classes of TGF-β inhibitor, namely i) ligand traps, ii) antisense oligonucleotides, iii) receptor kinase inhibitors and iv) peptide aptamers. Long term dosing strategies with TGF-β inhibitors may be ill-advised, since this class of drug has potentially highly pleiotropic activity, and development of drug resistance might potentiate tumor progression. Current paradigms for the use of TGF-β inhibitors in oncology have therefore moved towards the use of combinatorial therapies and short term dosing, with considerable promise for the clinic

Complexities of TGF-β Targeted Cancer Therapy

Many advanced tumors produce excessive amounts of Transforming Growth Factor-β (TGF-β) which, in normal epithelial cells, is a potent growth inhibitor. However, in oncogenically activated cells, the homeostatic action of TGF-β is often diverted along alternative pathways. Hence, TGF-β signaling elicits protective or tumor suppressive effects during the early growth-sensitive stages of tumorigenesis. However, later in tumor development when carcinoma cells become refractory to TGF-β-mediated growth inhibition, the tumor cell responds by stimulating pathways with tumor progressing effects. At late stages of malignancy, tumor progression is driven by TGF-β overload. The tumor microenvironment is a target of TGF-β action that stimulates tumor progression via pro-tumorigenic effects on vascular, immune, and fibroblastic cells. Bone is one of the richest sources of TGF-β in the body and a common site for dissemination of breast cancer metastases. Osteoclastic degradation of bone matrix, which accompanies establishment and growth of metastases, triggers further release of bone-derived TGF-β. This leads to a vicious positive feedback of tumor progression, driven by ever increasing levels of TGF-β released from both the tumor and bone matrix. It is for this reason, that pharmaceutical companies have developed therapeutic agents that block TGF-β signaling. Nonetheless, the choice of drug design and dosing strategy can affect the efficacy of TGF-β therapeutics. This review will describe pre-clinical and clinical data of four major classes of TGF-β inhibitor, namely i) ligand traps, ii) antisense oligonucleotides, iii) receptor kinase inhibitors and iv) peptide aptamers. Long term dosing strategies with TGF-β inhibitors may be ill-advised, since this class of drug has potentially highly pleiotropic activity, and development of drug resistance might potentiate tumor progression. Current paradigms for the use of TGF-β inhibitors in oncology have therefore moved towards the use of combinatorial therapies and short term dosing, with considerable promise for the clinic

Uptake Rates of Risk-Reducing Surgeries for Women at Increased Risk of Hereditary Breast and Ovarian Cancer Applied to Cost-Effectiveness Analyses: A Scoping Systematic Review

Simple Summary For women who have tested positive for BRCA mutations, the decision to make use of preventive surgical options, such as risk-reducing mastectomy (RRM) or risk-reducing bilateral salpingo-oophorectomy (RRSO), depends on the women's personal preferences and the cultural/social context. Among others, the cost-effectiveness of RRM and RRSO can be affected by the uptake rate of these preventive surgical options. Uptake rates of surgery should be given more attention in the conceptualization of health economic modeling studies for RRM and RRSO. Prospective multicenter studies are recommended to reflect regional and national variations in women's preferences for preventive surgery. The cost-effectiveness of genetic screen-and-treat strategies for women at increased risk for breast and ovarian cancer often depends on the women's willingness to make use of risk-reducing mastectomy (RRM) or salpingo-oophorectomy (RRSO). To explore the uptake rates of RRM and RRSO applied in health economic modeling studies and the impact of uptake rates on the incremental cost-effectiveness ratios (ICER), we conducted a scoping literature review. In addition, using our own model, we conducted a value of information (VOI) analysis. Among the 19 models included in the review, the uptake rates of RRM ranged from 6% to 47% (RRSO: 10% to 88%). Fifty-seven percent of the models applied retrospective data obtained from registries, hospital records, or questionnaires. According to the models' deterministic sensitivity analyses, there is a clear trend that a lower uptake rate increased the ICER and vice versa. Our VOI analysis showed high decision uncertainty associated with the uptake rates. In the future, uptake rates should be given more attention in the conceptualization of health economic modeling studies. Prospective studies are recommended to reflect regional and national variations in women's preferences for preventive surgery

Uptake Rates of Risk-Reducing Surgeries for Women at Increased Risk of Hereditary Breast and Ovarian Cancer Applied to Cost-Effectiveness Analyses: A Scoping Systematic Review

The cost-effectiveness of genetic screen-and-treat strategies for women at increased risk for breast and ovarian cancer often depends on the women&rsquo;s willingness to make use of risk-reducing mastectomy (RRM) or salpingo-oophorectomy (RRSO). To explore the uptake rates of RRM and RRSO applied in health economic modeling studies and the impact of uptake rates on the incremental cost-effectiveness ratios (ICER), we conducted a scoping literature review. In addition, using our own model, we conducted a value of information (VOI) analysis. Among the 19 models included in the review, the uptake rates of RRM ranged from 6% to 47% (RRSO: 10% to 88%). Fifty-seven percent of the models applied retrospective data obtained from registries, hospital records, or questionnaires. According to the models&rsquo; deterministic sensitivity analyses, there is a clear trend that a lower uptake rate increased the ICER and vice versa. Our VOI analysis showed high decision uncertainty associated with the uptake rates. In the future, uptake rates should be given more attention in the conceptualization of health economic modeling studies. Prospective studies are recommended to reflect regional and national variations in women&rsquo;s preferences for preventive surgery