Zerotree-based stereoscopic video CODEC

Due to the provision of a more natural representation of a scene in the form of left and right eye views, a stereoscopic imaging system provides a more effective method for image/video display. Unfortunately the vast amount of information that must be transmitted/stored to represent a stereo image pair/video sequence, has so far hindered its use in commercial applications. However, by properly exploiting the spatial, temporal and binocular redundancy, a stereo image pair or a sequence could be compressed and transmitted through a single monocular channel’s bandwidth without unduly sacrificing the perceived stereoscopic image quality. We propose a timely and novel framework to transmit stereoscopic data efficiently. We propose a timely and novel framework to transmit stereoscopic data efficiently. We present a new technique for coding stereo video sequences based on discrete wavelet transform DWT technology. The proposed technique particularly exploits zerotree entropy ZTE coding that makes use of the wavelet block concept to achieve low bit rate stereo video coding. One of the two image streams, namely, the main stream, is independently coded by a zerotree video CODEC, while the second stream, namely, the auxiliary stream, is predicted based on disparity compensation. A zerotree video CODEC subsequently codes the residual stream. We compare the performance of the proposed CODEC with a discrete cosine transform DCT -based, modified MPEG-2 stereo video CODEC. We show that the proposed CODEC outperforms the benchmark CODEC in coding both main and auxiliary streams

Inhibiting IRE1α-endonuclease activity decreases tumor burden in a mouse model for hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a liver tumor that usually arises in patients with cirrhosis. Hepatic stellate cells are key players in the progression of HCC, as they create a fibrotic micro-environment and produce growth factors and cytokines that enhance tumor cell proliferation and migration. We assessed the role of endoplasmic reticulum (ER) stress in the cross-talk between stellate cells and HCC-cells. Mice with a fibrotic HCC were treated with the IRE1α-inhibitor 4μ8C, which reduced tumor burden and collagen deposition. By co-culturing HCC-cells with stellate cells, we found that HCC-cells activate IREα in stellate cells, thereby contributing to their activation. Inhibiting IRE1α blocked stellate cell activation, which then decreased proliferation and migration of tumor cells in different in vitro 2D and 3D co-cultures. In addition, we also observed cell-line specific direct effects of inhibiting IRE1α in tumor cells

Stability of hepatitis B virus pregenomic RNA in plasma specimens under various temperatures and storage conditions

Background. Hepatitis B virus (HBV) pregenomic RNA (pgRNA) has gained increasing attention owing to its role in replication of covalently closed circular DNA (cccDNA) in HBV. This marker has the potential to be used in clinical programs aimed to manage HBV infections. However, several reports on HBV pgRNA levels in clinical cases have conflicting results. RNA is easily degraded when exposed to heat and other environmental stressors. However, the stability of HBV pgRNA, during blood sample collection before the standard automated quantification, has never been estimated. This study aimed to demonstrate the effect of two different temperature conditions and storage durations on the stability of HBV pgRNA. Method. Blood from forty patients with chronic hepatitis B infection, who also showed evidence of active HBV DNA replication, was collected and processed within 2 h of collection. Plasma from each patient was divided and stored at 4 ◦C and 25 ◦C (room temperature) for six different storage durations (0, 2, 6, 12, 24, and 48 h) and subsequently transferred to −80 ◦C for storage. The effect of multiple cycles of freezing and thawing of plasma at −20 ◦C or −80 ◦C was evaluated using samples from ten patients. Quantification of pgRNA from the samples was performed simultaneously, using the digital polymerase chain reaction (dPCR) method. The differences in pgRNA levels at baseline and each time point were compared using generalized estimating equation (GEE). A change greater than 0.5 log10 copies/mL of pgRNA is considered clinically significant. Statistical analyses were conducted using Stata 16.0. Results. The mean HBV pgRNA level in the initially collected plasma samples was 5.58 log10 copies/mL (ranging from 3.08 to 8.04 log10 copies/mL). The mean pgRNA levels in samples stored for different time periods compared with the initial reference sample (time 0) significantly decreased. The levels of pgRNA for 6, 12, 24, and 48 h of storage reduced by −0.05 log10 copies/mL (95% confidence interval (CI) −0.095 to −0.005, p = 0.03), −0.075 log10 copies/mL (95% CI [−0.12 to −0.03], p = 0.001), −0.084 log10 copies/mL (95% CI [−0.13 to −0.039], p =< 0.001), and −0.120 log10 copies/mL (95% CI [−0.17 to −0.076], p =< 0.001), respectively. However, these changes were below 0.5 log10 copies/mL and thus were not clinically significant. Compared with the samples stored at 4 ◦C, there were no significant differences in pgRNA levels in samples stored at 25 ◦C for any of the storage durations (−0.01 log10 copies/mL; 95% CI [−0.708 to 0.689], p = 0.98). No significant difference in the levels of pgRNA was observed in the plasma samples, following four freeze-thaw cycles at −20 ◦C and −80 ◦C. Conclusion. The plasma HBV pgRNA level was stable at 4 ◦C and at room temperature for at least 48 h and under multiple freeze-thaw cycles. Our results suggest that pgRNA is stable during the process of blood collection, and therefore results of pgRNA quantification are reliable

Non-invasive tests for liver fibrosis assessment in patients with chronic liver diseases: a prospective study

There is an urgent need of non-invasive tests (NITs) for monitoring treatment response and disease progression in chronic liver disease. Liver stiffness (LS) evaluated by transient elastography (TE), shear wave elastography (SWE), and magnetic resonance elastography (MRE) and serum markers e.g. APRI and FIB-4 scores were assessed at baseline and the 1-year follow-up. In all, 89 chronic hepatitis C virus (HCV) patients with sustained virological response and 93 non-alcoholic fatty liver disease (NAFLD) patients were included. There was a significantly strong correlation among imaging techniques. Using MRE as the reference standard, the area under the receiver operating characteristics curves for TE, SWE, APRI, and FIB-4 in detecting stage1–4 fibrosis were 0.88–0.95, 0.87–0.96, 0.83–0.89, and 0.79–0.92, respectively. In chronic HCV patients, the values of TE, SWE, MRE, APRI and FIB-4 significantly decreased from baseline to the 1-year follow-up. Liver steatosis did not significantly change over time. In NAFLD, compared to obese patients, non-obese patients had less LS and steatosis at baseline, and these values did not show significant changes at the 1-year follow-up. Our study suggests that the current NITs have a good correlation and accuracy in monitoring the treatment outcomes in patients with chronic liver diseases

Validation and prognostic value of EZ-ALBI score in patients with intermediate-stage hepatocellular carcinoma treated with trans-arterial chemoembolization

Background: Heterogeneity of liver function and tumor burden in intermediate-stage hepatocellular carcinoma (HCC) results in different outcomes after transarterial chemoembolization (TACE). Easy albumin-bilirubin (EZ-ALBI), a simplified albumin-bilirubin (ALBI) score, has recently been proposed as a new prognostic score for HCC. This study aimed to validate the EZ-ALBI score and evaluate the impact of dynamic changes in patients with intermediate-stage HCC undergoing TACE. Methods: All patients with HCC treated with TACE at King Chulalongkorn Memorial Hospital, Bangkok, Thailand, between January 2015 and December 2019 were prospectively enrolled. Intermediate-stage HCC was defined as Barcelona Clinic Liver Cancer (BCLC) stage B or unresectable single HCC with size > 5 cm in BCLC stage A. EZ-ALBI and ALBI scores were calculated and stratified into three different grades. Overall survival (OS) and prognostic factors were assessed using the Kaplan–Meier curve and Cox proportional hazard model. Decision analysis curves were used to evaluate the clinical utility of the predictive scores. Results: Among 672 patients with HCC treated with TACE, 166 patients with intermediate-stage HCC who met the eligibility criteria were enrolled. The median OS of all patients in the cohort was 21 months. A good correlation between the EZ-ALBI and ALBI scores was observed (correlation coefficient 1.000, p 20 ng/ml were significantly associated with OS [hazard ratio (HR) 2.20 (95% confidence interval [CI] 1.24–3.88, p = 0.007), 3.26 (95% CI 1.24–8.57, p = 0.016), and 1.77 (95% CI 1.10–2.84, p = 0.018), respectively]. Following TACE, 42 (29.6%) patients had a worsening EZ-ALBI grade. However, the EZ-ALBI grade migration was not significantly correlated with OS. EZ-ALBI and ALBI score provided improved discriminatory ability (Harrell’s concordance index 0.599 and 0.602, respectively) and better net benefit compared with Child-Turcotte-Pugh and Model for End-stage Liver Disease scores. Conclusions: The baseline EZ-ALBI score demonstrated good predictive performance for survival and a strong correlation with conventional ALBI scores. Both the EZ-ALBI and ALBI scores outperformed other prognostic models in patients with intermediate-stage HCC receiving TACE. However, the dynamic change in the EZ-ALBI grade after TACE was not associated with postprocedural survival

Chemometric Analysis of a Ternary Mixture of Caffeine, Quinic Acid, and Nicotinic Acid by Terahertz Spectroscopy

Caffeine, quinic acid, and nicotinic acid are among the significant chemical determinants of coffee quality. This study develops a chemometric model to quantify these compounds in ternary mixtures analyzed by terahertz time-domain spectroscopy (THz-TDS). A data set of 480 THz spectra was obtained from 80 samples. Combinations of data preprocessing methods, including normalization (Z-score, min-max scaling, Mie baseline removal) and dimensionality reduction (principal component analysis (PCA), factor analysis (FA), independent component analysis (ICA), locally linear embedding (LLE), non-negative matrix factorization (NMF), isomap), and prediction models (partial least-squares regression (PLSR), support vector regression (SVR), multilayer perceptron (MLP), convolutional neural network (CNN), gradient boosting) were analyzed for their prediction performance (totaling to 4,711,685 combinations). Results show that the highest quantification performance was achieved at a root-mean-square error of prediction (RMSEP) of 0.0254 (dimensionless mass ratio), using min-max scaling and factor analysis for data preprocessing and multilayer perceptron for prediction. Effects of preprocessing, comparison of prediction models, and linearity of data are discussed

Immunogenicity, Immune Dynamics, and Subsequent Response to the Booster Dose of Heterologous versus Homologous Prime-Boost Regimens with Adenoviral Vector and mRNA SARS-CoV-2 Vaccine among Liver Transplant Recipients: A Prospective Study

BACKGROUND: Heterologous prime-boost vaccination potentially augments the immune response against SARS-CoV-2 in liver transplant (LT) recipients. We investigated immunogenicity induced by different primary prime-boost vaccination protocols and the subsequent response to the booster vaccine among LT recipients. METHODS: LT recipients, who received primary immunisation with ChAdOx1/ChAdOx1 or ChAdOx1/BNT162b2, were administered the third dose of mRNA-1273 three months following the primary vaccination. Blood samples were collected before and after primary vaccination and post-booster. The levels of receptor binding domain antibody (anti-RBD) and neutralising antibody (sVNT) and spike-specific T-cell responses were assessed. RESULTS: Among the 89 LT recipients, patients receiving ChAdOx1/BNT162b2 had significantly higher anti-RBD titres, sVNT, and cellular response after primary vaccination than those receiving ChAdOx1/ChAdOx1 (p 90% of LT patients, with only 12.3% positive against the Omicron variant. CONCLUSIONS: ChAdOx1/BNT162b2 evoked a significantly higher immunological response than ChAdOx1/ChAdOx1 in LT recipients. The booster strategy substantially induced robust immunity against wild type in most patients but was less effective against the Omicron strain

Optimization and validation of a novel three-dimensional co-culture system in decellularized human liver scaffold for the study of liver fibrosis and cancer

The introduction of new preclinical models for in vitro drug discovery and testing based on 3D tissue-specific extracellular matrix (ECM) is very much awaited. This study was aimed at developing and validating a co-culture model using decellularized human liver 3D ECM scaffolds as a platform for anti-fibrotic and anti-cancer drug testing. Decellularized 3D scaffolds obtained from healthy and cirrhotic human livers were bioengineered with LX2 and HEPG2 as single and co-cultures for up to 13 days and validated as a new drug-testing platform. Pro-fibrogenic markers and cancer phenotypic gene/protein expression and secretion were differently affected when single and co-cultures were exposed to TGF-β1 with specific ECM-dependent effects. The anti-fibrotic efficacy of Sorafenib significantly reduced TGF-β1-induced pro-fibrogenic effects, which coincided with a downregulation of STAT3 phosphorylation. The anti-cancer efficacy of Regorafenib was significantly reduced in 3D bioengineered cells when compared to 2D cultures and dose-dependently associated with cell apoptosis by cleaved PARP-1 activation and P-STAT3 inhibition. Regorafenib re-versed TGF-β1-induced P-STAT3 and SHP-1 through induction of epithelial mesenchymal marker E-cadherin and downregulation of vimentin protein expression in both co-cultures engrafting healthy and cirrhotic 3D scaffolds. In their complex, the results of the study suggest that this newly proposed 3D co-culture platform is able to reproduce the natural physio-pathological microenvi-ronment and could be employed for anti-fibrotic and anti-HCC drug screening