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Introduction: We aimed to analyse the changing trends, safety and outcomes associated with the adoption of laparoscopic liver resection (LLR) at a single centre., Methods: A retrospective review of patients who underwent LLR from 2006 to 2014 at our institution was performed. To explore the evolution of LLR, the study was divided into three equal consecutive time periods (Period 1: 2006-2008, Period 2: 2009-2011, and Period 3: 2012-2014)., Results: Among 195 patients who underwent LLR, 24 (12.3%) required open conversions, 68 (34.9%) had resection of tumours in the difficult posterosuperior segments and 12 (6.2%) underwent major (≥ 3 segments) hepatectomies. Median operation time was 210 (range 40-620) minutes and median postoperative stay was 4 (range 1-26) days. Major postoperative morbidity (> Grade II) occurred in 11 (5.6%) patients and 90-day/in-hospital mortality was 1 (0.5%). During the study, the number of LLRs performed showed an increasing trend (Period 1: n = 22; Period 2: n = 19; Period 3: n = 154). Other statistically significant trends were: (a) increase in malignant neoplasms resected; (b) increase in resections of difficult posterosuperior segments; (c) longer median operation time; and (d) decrease in open conversion rates., Conclusion: Over the study period, the number of LLRs increased rapidly. LLR was increasingly performed for malignant neoplasms and lesions located in the difficult posterosuperior segments, resulting in longer operation times. However, open conversion rates decreased, and there was no change in postoperative morbidity and other perioperative outcomes., (Copyright: © Singapore Medical Association)

Respiratory gating has been widely applied for respiratory correction or compensation in image acquisition and image-guided interventions. A novel image-based method is proposed to extract respiratory signal directly from 2D ultrasound liver images. The proposed method utilizes a typical manifold learning method, based on local tangent space alignment based technique, to detect principal respiratory motion from a sequence of ultrasound images. This technique assumes all the images lying on a low-dimensional manifold embedding into the high-dimensional image space, constructs an approximate tangent space of each point to represent its local geometry on the manifold, and then aligns the local tangent spaces to form the global coordinate system, where the respiratory signal is extracted. The experimental results show that the proposed method can detect relatively accurate respiratory signal with high correlation coefficient (0.9775) with respect to the ground-truth signal by tracking external markers, and achieve satisfactory computing performance (2.3s for an image sequence of 256 frames). The proposed method is also used to create breathing-corrected 3D ultrasound images to demonstrate its potential application values., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Purpose:    In model-based respiratory motion estimation for the liver or other abdominal organs, the surrogate respiratory signal is usually obtained by using special tracking devices from skin or diaphragm, and subsequently applied to parameterize a 4D motion model for prediction or compensation. However, due to the intrinsic limits and economical costs of these tracking devices, the identification of the respiratory signal directly from intra-operative ultrasound images is a more attractive alternative., Methods:    We propose a fast and robust method to extract the respiratory motion of the liver from an intra-operative 2D ultrasound image sequence. Our method employs a preprocess to remove speckle-like noises in the ultrasound images and utilizes the normalized cross-correlation to measure the image similarity fast. More importantly, we present a novel adaptive search strategy, which makes full use of the inter-frame dependency of the image sequence. This search strategy narrows the search range of the optimal matching, thus greatly reduces the search time, and makes the matching process more robust and accurate., Results:    The experimental results on four volunteers demonstrate that our method is able to extract the respiratory signal from an image sequence of 256 image frames in 5 s. The quantitative evaluation using the correlation coefficient reveals that the respiratory motion, extracted near the liver boundaries and vessels, is highly consistent with the reference motion tracked by an EM device., Conclusions:    Our method can use 2D ultrasound to track natural landmarks from the liver as surrogate respiratory signal and hence provide a feasible solution to replace special tracking devices.

Objective: The aim of this study was to characterize the population frequency of SLCO1B1 polymorphic variants in three distinct healthy Asian populations, namely Chinese (n = 100), Malay (n = 100) and Indian (n = 100), and to explore the association between haplotype-tagged single nucleotide polymorphisms (htSNPs) on hepatic SLCO1B1 mRNA expression., Methods: The distribution of polymorphic variants in the SLCO1B1 gene at eight loci that spanned approximately 48 kb was investigated in the three different Asian ethnic groups and in 32 non-cancerous liver tissues from Chinese patients., Results: Of the 26 polymorphisms screened, we found eight polymorphic variants that differed in genotypic and allelic frequencies between the Chinese, Malay and Indian populations. Significant interethnic differences were observed in the genotype frequency distributions across the promoter SNP [g.-11187G>A (P = 0.030)] as well as three coding region SNPs [c.388G>A (P < 0.001); c.571T>C (P < 0.001); c.597C>T (P < 0.001)] in the healthy subjects. Haplotype analysis revealed 12 different haplotypes in both the Chinese and Malay populations and 18 haplotypes in the Indian population. In both the Malay and Indian populations, the htSNPs were c.388A>G, c.571T>C and c.597C>T, whereas in the Chinese population they were g.-11187G>A, c.388A>G and c.597C>T. The c.388A>G and c.597C>T htSNPs accounted for more than 70% of the variations between the three major haplotypes in each Asian ethnic group. In terms of the c.388A>G htSNPs, genotypic-phenotypic association analyses revealed that there was no effect on SLCO1B1 expression in hepatic tissues; in addition, no genotypic-phenotypic associations were evident with regards to the c.597C>T htSNP., Conclusion: Future studies should investigate the phenotypic effects of the c.388A>G htSNP on the disposition of OATP1B1 substrates in Asian populations.

Sclerosing haemangioma is a rare variant of hepatic haemangioma. The radiological features on computed tomography and magnetic resonance imaging may not be typical for haemangioma and can be confused with hepatocellular carcinoma. We report sclerosing haemangioma occurring in a 65-year-old woman where the radiological features raise the possibility of hepatocellular carcinoma.

We report the identification of a novel cDNA fragment that shows significantly reduced expression in cancerous tissue compared with paired non-cancerous liver tissue in patients with hepatocellular carcinoma (HCC). The full-length transcript of 1733 bp encodes a protein of 308 amino acids that has all the hallmark features of mitochondrial carrier proteins. We designate the novel protein as HDMCP (HCC-down-regulated mitochondrial carrier protein). The HDMCP orthologs in human, mouse, and rat are found to exhibit close similarity in protein sequence and gene organization, as well as exclusive expression in the liver. Moreover, conserved syntenic regions have been demonstrated at the HDMCP gene locus in the human, mouse, and rat genome. Taken together, we suggest that HDMCP might have a conserved and unique biological function in the liver. Overexpression of HDMCP in transiently transfected cancer cells results in the loss of staining by MitoTracker dye, indicating that HDMCP could induce the dissipation of mitochondrial membrane potential (DeltaPsim). However, HDMCP-mediated disruption of DeltaPsim is not related to mitochondrial permeability transition or apoptosis. In addition, we further demonstrate that the dissipation of DeltaPsim is accompanied by significant reduction of cellular ATP in 293T cells overexpressing HDMCP or uncoupling protein 2 (UCP2). Our present findings suggest that HDMCP might be one of the long postulated uncoupling proteins that catalyze the physiological "proton leak" in the liver. The down-regulation of HDMCP in HCC cancer cells might result in the elevation of DeltaPsim, a common phenomenon found in cancer cells.

Introduction: We compare the breath-hold fast recovery fast spin echo (BHFRFSE) T2-weighted and non-breath-hold fast spin echo (NBHFSE) T2-weighted sequences in image quality and lesion characterisation of focal liver lesions., Materials and Methods: Fat-suppressed T2-weighted magnetic resonance (MR) images obtained with the 2 sequences (BHFRFSE and NBHFSE) in 79 patients with 113 liver lesions were analysed retrospectively. The image quality and nature of the lesions were evaluated by 2 experienced radiologists., Results: Based on receiver operating characteristic curve analysis, lesion characterisation was comparable for both sequences. The image quality of BHFRFSE was significantly better than that of NBHFSE. The NBHFSE missed 4 malignant lesions while BHFRFSE missed 2 malignant lesions., Conclusion: BHFRFSE performs similarly to NBHFSE in image quality and liver lesion characterisation.

The recognition of hepatic stellate cells (HSC) around and within hepatocellular carcinoma (HCC) in human livers has generated interest in the interactions between HSC and HCC. We explored the possibility of creating an animal model to allow in vivo investigations of this interaction. Eighteen adult Buffalo rats were inoculated with 1 x 10(6) cells obtained from cultures of Morris 7777 hepatoma cell line (ATCC). The rats were sacrificed at 2-, 3-, and 4-week intervals. Identification of activated HSC was with immunohistochemistry for alpha-smooth muscle actin (alpha-SMA). There was 100% survival of all animals until sacrifice. Tumour formation occurred in 94.4% of rats, and was of a good size by two weeks. Expression of alpha-SMA was observed around and within all HCC, but absent from normal tissue, and this showed colocalisation with collagen deposition. These findings are consistent with those previously reported in resected HCC in humans. The high survival, good tumour yield, consistent generation of activated HSC around the tumours, and similarities in histological appearance to the human HSC-HCC distribution pattern, make this a reliable animal model for in vivo studies on HSC-HCC interaction.

In vitro studies designed to examine the mechanisms of immune tolerance after liver transplantation in humans have been hampered by the difficulty in obtaining sufficient numbers of donor liver-associated leukocytes (LALs). We have investigated whether the ex vivo perfusion of donor livers releases a population of LALs that can be readily retrieved from the waste fluid. The mean number of cells recovered after Ficoll-Hypaque density-gradient separation was 2.6 +/- 0.5 x 10(8) cells, with a viability of 94% +/- 2%. The perfusate lymphocytes comprised mainly T cells (39% +/- 2%) with a very low CD4/CD8 ratio and natural killer (NK) cells (56% +/- 6%) with an increase in the proportion of the CD3-CD56+CD16- subset. The activation marker CD69 was present on the majority of the perfusate lymphocytes. These are the phenotypic characteristics that have been previously reported for lymphocytes isolated from hepatic sinusoids. In mixed lymphocyte reactions, the perfusate cells showed a marked increase in the ability to stimulate allogeneic responder cells, resulting in 353% +/- 78% (P = .003) greater incorporation of [3H]thymidine in responder cells when compared with stimulation by donor peripheral blood mononuclear cells. The results show that large numbers of viable donor lymphocytes can be readily isolated from the liver perfusate solution. These cells have the characteristics of liver-associated lymphocytes with a predominance of activated NK and CD8+ T cells. This population can now be used in in vitro assays to elucidate the influence of donor leukocytes on the development of graft acceptance.