Cristin Constantin Vere

Nonalcoholic fatty liver disease, metabolic risk factors, and hepatocellular carcinoma: an open question.

Non-alcoholic liver disease (NAFLD) defines liver abnormalities ranging from simple steatosis to nonalcoholic steatohepatitis with or without cirrhosis development, occurring in the absence of significant alcohol consumption, use of teratogenic medication, or hereditary disorders. The association between NAFLD and metabolic syndrome is well documented and widely recognized. Obesity, type 2 diabetes mellitus (T2DM), and dyslipidemia are the most common metabolic risk factors associated with NAFLD. Among the components of metabolic syndrome, current evidence strongly indicates obesity and diabetes as hepatocellular carcinoma (HCC) risk factors. There is also growing evidence that suggests an increased risk of HCC in NAFLD patients, even surpassing other etiologies in some high-income countries. Epidemiologic data demonstrate a parallel rise in prevalence of obesity, diabetes, NAFLD, and HCC. As obesity and its related diseases have steadily afflicted larger populations, HCC incidence is expected to increase in the future. Pathophysiologic mechanisms that underlie NAFLD development and subsequent progression to nonalcoholic steatohepatitis and cirrhosis (insulin resistance and hyperinsulinemia, oxidative stress, hepatic stellate cell activation, cytokine/adipocytokine signaling pathways, and genetic and environmental factors) appear to play a significant role in the development of NAFLD-related HCC. However, a comprehensive view of molecular mechanisms linking obesity, T2DM, and NAFLD-related HCC, as well as the exact sequence of molecular events, is still not understood in its entirety. Good-quality data are still necessary, and efforts should continue towards better understanding the underlying carcinogenic mechanisms of NAFLD-related HCC. In this paper, we aimed to centralize the most important links supporting these relationships, focusing on obesity, T2DM, and NAFLD-related HCC, as well as point out the major gaps in knowledge regarding the underlying molecular mechanisms behind them.

Lipid Serum Profile in Patients with Viral Liver Cirrhosis

Objective: Our main aim was to investigate the serum lipid levels in a series of patients with liver cirrhosis of viral origin. Subjects and Methods: The study comprised 90 patients, 60 with viral liver cirrhosis, equally divided between hepatitis virus C (HCV) and B (HBV) etiologies, and 30 control patients with no known liver pathology. Patients were investigated during a 5-year period in the 1st Medical Clinic of the Emergency County Hospital of Craiova, Romania. The following series of serum lipid parameters were recorded: lipemia, total cholesterol and cholesteryl ester, high-density lipoprotein (HDL) cholesterol, low-density lipoprotein (LDL) cholesterol, very-low-density lipoprotein (VLDL) cholesterol and triglyceride (TG) values. Statistical analysis of these parameters was performed using the ANOVA test followed by Tukey multiple comparison tests to compare replicate means; p < 0.05 was considered statistically significant. Results: We observed significantly lower values for serum lipids (543.5 and 549.37 mg/dl in the HBV and HCV cirrhosis subgroups, compared with 649.9 mg/dl in controls), total cholesterol (143.6 and 147.9 vs. 198.0 mg/dl, respectively), cholesteryl esters (83.6 and 80, compared to 147.9 mg/dl, respectively), LDL cholesterol (91.6 and 88.5 vs. 132.4 mg/dl) in both cirrhosis groups when compared with controls (p < 0.001), as well as HDL cholesterol (32.1 and 36.9 vs. 47.3 mg/dl, p < 0.05). However, TG and VLDL cholesterol values of controls and cirrhosis groups were similar (p > 0.05). We did not register any differences between the two cirrhosis groups (p > 0.05). Conclusion: Our data showed that both HCV and HBV cirrhosis severely impaired liver lipid metabolism. Late stages of the disease resulted in a pseudonormalization of VLDL cholesterol and TG values.

Contrast-enhanced ultrasonography parameters in neural network diagnosis of liver tumors

AIM To study the role of time-intensity curve (TIC) analysis parameters in a complex system of neural networks designed to classify liver tumors. METHODS We prospectively included 112 patients with hepatocellular carcinoma (HCC) (n = 41), hypervascular (n = 20) and hypovascular (n = 12) liver metastases, hepatic hemangiomas (n = 16) or focal fatty changes (n = 23) who underwent contrast-enhanced ultrasonography in the Research Center of Gastroenterology and Hepatology, Craiova, Romania. We recorded full length movies of all contrast uptake phases and post-processed them offline by selecting two areas of interest (one for the tumor and one for the healthy surrounding parenchyma) and consecutive TIC analysis. The difference in maximum intensities, the time to reaching them and the aspect of the late/portal phase, as quantified by the neural network and a ratio between median intensities of the central and peripheral areas were analyzed by a feed forward back propagation multi-layer neural network which was trained to classify data into five distinct classes, corresponding to each type of liver lesion. RESULTS The neural network had 94.45% training accuracy (95% CI: 89.31%-97.21%) and 87.12% testing accuracy (95% CI: 86.83%-93.17%). The automatic classification process registered 93.2% sensitivity, 89.7% specificity, 94.42% positive predictive value and 87.57% negative predictive value. The artificial neural networks (ANN) incorrectly classified as hemangyomas three HCC cases and two hypervascular metastases, while in turn misclassifying four liver hemangyomas as HCC (one case) and hypervascular metastases (three cases). Comparatively, human interpretation of TICs showed 94.1% sensitivity, 90.7% specificity, 95.11% positive predictive value and 88.89% negative predictive value. The accuracy and specificity of the ANN diagnosis system was similar to that of human interpretation of the TICs (P = 0.225 and P = 0.451, respectively). Hepatocellular carcinoma cases showed contrast uptake during the arterial phase followed by wash-out in the portal and first seconds of the late phases. For the hypovascular metastases did not show significant contrast uptake during the arterial phase, which resulted in negative differences between the maximum intensities. We registered wash-out in the late phase for most of the hypervascular metastases. Liver hemangiomas had contrast uptake in the arterial phase without agent wash-out in the portal-late phases. The focal fatty changes did not show any differences from surrounding liver parenchyma, resulting in similar TIC patterns and extracted parameters. CONCLUSION Neural network analysis of contrast-enhanced ultrasonography - obtained TICs seems a promising field of development for future techniques, providing fast and reliable diagnostic aid for the clinician.

Focus on alcoholic liver disease:From nosography to treatment

Abusive alcohol intake currently ranks as a major cause of liver disease, and is associated with significant mortality worldwide. Alcoholic liver disease (ALD) generically defines liver abnormalities ranging from liver steatosis to the end-stages of disease such as liver cirrhosis. Information regarding the precise incidence and prevalence of ALD is still limited by a lack of large population-based studies and by the absence of large systematic reviews of all epidemiological data available. However, existing collected data show an overall increase in the number of alcohol abusers and alcohol-related liver disease. The burden exerted on medical systems worldwide is significant, with hospitalization and management costs rising constantly over the years. A great number of all cirrhosis-related deaths in Europe and a significant percentage worldwide are associated with alcohol consumption. The main possible risk factors for ALD are the amount and duration of alcohol abuse, patterns of drinking and the type of alcoholic beverage consumed. However, ALD does not progress to cirrhosis in all patients, therefore a series of additional factors are implicated. Even though insufficiently studied, genetic factors are generally regarded as highly important, and the presence of comorbidities and dietary habits seem to play a role in disease onset and progression. This lack of clear pathophysiological data further translates in the absence of definite treatment for ALD and shall prove challenging in the coming years. In this article, we aimed to briefly review epidemiologic data on the burden of ALD, risk factors, clinical and nosographic as well as therapeutic aspects of this disease. Without attempting to be exhaustive, this short topic highlight emphasizes each point and may serve as a general guidance tool in the complicated literature related to ALD.

Diagnosis System for Hepatocellular Carcinoma Based on Fractal Dimension of Morphometric Elements Integrated in an Artificial Neural Network

Background and Aims. Hepatocellular carcinoma (HCC) remains a leading cause of death by cancer worldwide. Computerized diagnosis systems relying on novel imaging markers gained significant importance in recent years. Our aim was to integrate a novel morphometric measurement—the fractal dimension (FD)—into an artificial neural network (ANN) designed to diagnose HCC. Material and Methods. The study included 21 HCC and 28 liver metastases (LM) patients scheduled for surgery. We performed hematoxylin staining for cell nuclei and CD31/34 immunostaining for vascular elements. We captured digital images and used an in-house application to segment elements of interest; FDs were calculated and fed to an ANN which classified them as malignant or benign, further identifying HCC and LM cases. Results. User intervention corrected segmentation errors and fractal dimensions were calculated. ANNs correctly classified 947/1050 HCC images (90.2%), 1021/1050 normal tissue images (97.23%), 1215/1400 LM (86.78%), and 1372/1400 normal tissues (98%). We obtained excellent interobserver agreement between human operators and the system. Conclusion. We successfully implemented FD as a morphometric marker in a decision system, an ensemble of ANNs designed to differentiate histological images of normal parenchyma from malignancy and classify HCCs and LMs.

Role of intrahepatic innervation in regulating the activity of liver cells

Liver innervation comprises sympathetic, parasympathetic and peptidergic nerve fibers, organized as either afferent or efferent nerves with different origins and roles. Their anatomy and physiology have been studied in the past 30 years, with different results published over time. Hepatocytes are the main cell population of the liver, making up almost 80% of the total liver volume. The interaction between hepatocytes and nerve fibers is accomplished through a wealth of neurotransmitters and signaling pathways. In this short review, we have taken the task of condensing the most important data related to how the nervous system interacts with the liver and especially with the hepatocyte population, how it influences their metabolism and functions, and how different receptors and transmitters are involved in this complex process.

STATINS IN THE TREATMENT OF HEPATITIS C

Hepatitis C virus (HCV) infection is an important health issue because it affects about 3% of the world population.It is estimated that 65–80% of HCV infections progress to chronic disease, and more than 20–50% of patients with chronic hepatitis develop hepatic cirrhosis. Hepatocellular carcinoma complicates 5% of the chronic hepatitis C cases [1][2]. Combination therapy with peginterferon-ribavirin, which is currently the standard treatment for chronic hepatitis C, shows a sustained virological response in 55% of patients. The remaining 45% of patients do not respond to antiviral therapy and are at risk of the HCV infection progressing to hepatic cirrhosis and hepatocellular carcinoma [3]. In addition, because of the numerous adverse effects and possible contraindications to the use of combination therapy with peginterferon and ribavirin, the administration of this antiviral therapy is limited to only some patients with chronic hepatitis C [4]. Because of these limitations, it is necessary to discover new therapeutic agents for eradicating HCV infection. Several recent studies have shown that statins, commonly used as cholesterol-lowering medication, can inhibit the replication of HCV [3][5][6]. Ikeda et al. [2] have reported in their 2006 study that statins can inhibit in vitro HCV replication. Using OR6 cells infected with HCV, the authors evaluated the antiviral activity of 5 statins: atorvastatin, fluvastatin, lovastatin, pravastatin, and simvastatin. All statins, except pravastatin, that were tested as monotherapy inhibited viral replication. Fluvastatin exhibited the strongest antiviral effect, whereas atorvastatin and simvastatin showed moderate inhibitory effects, and lovastatin exhibited a weak inhibitory effect on HCV replication. All of these statins exert a cholesterol-lowering effect by inhibiting the activity of 3-hydroxy3-methyl-glutaryl coenzyme A (HMG-CoA) reductase, an enzyme involved in cholesterol synthesis. Pravastatin, unlike the other tested statins, has no antiviral activity; hence, it inhibits HCV replication not by a direct action on HMG-CoA reductase, but by a specific antiviral mechanism [3]. In order to emphasize the presence of an existing antiviral mechanism, the authors showed that the antiviral activity of statins is not due to hepatotoxicity; they proved so by demonstrating that HCV replication is not inhibited by the destruction of hepatocytes [3]. Several in vivo studies have shown that the administration of statins in patients with chronic HCV infection is safe and has no severe adverse effects [7][8][9]. For its replication, HCV requires a number of proteins, which are involved in cholesterol synthesis. Statins are considered to exert their antiviral activity by blocking these proteins. Thus,by inhibiting HMG-CoA reductase activity, statins reduce the intracellular concentration of geranylgeranyl pyrophosphate, which lowers the level of mevalonate necessary in cholesterol synthesis. A strong argument in favor of this theory is the fact that adding geranylgeraniol and mevalonate in cell cultures treated with statins leads to the restoration of viral replication. In the same study, Ikeda et al. [2] evaluated the possibility of replacing ribavirin with statins in the treatment of chronic hepatitis C. The efficacy of each tested statin was evaluated in combination therapy with interferon. All the statins, except pravastatin, showed higher inhibition of HCV replication when used in combination with interferon than when used as monotherapy. Interferon–fluvastatin combination therapy had the strongest antiviral effect, and the authors consider that this treatment is superior to standard therapy with interferon and ribavirin [3]. Another recently published study [10], which evaluated in vitro anti-HCV activity of 5 statins, confirmed the Japanese authors’ findings. According to these authors, mevastatin and simvastatin administered as mono-therapy have the strongest antiviral activity; lovastatin and fluvastatin have a moderate antiviral effect, while pravastatin has no antiviral activity. In addition, mevastatin and simvastatin enhance the antiviral activity of interferon α and of drugs that inhibit viral replication; mevastatin also prevents or reduces resistance to therapy with viral replication inhibitors [10]. Results of in vivo studies are controversial. According to the Initiating Dialysis Early and Late (IDEAL) study published in 2009, statins combined with peginterferon–ribavirin therapy significantly increase the sustained virological response rate, which is independent of serum lipid levels before the initiation of antiviral therapy. The findings of this retrospective study were not conclusive because of the small sample size; only 66 of the 3070 patients infected with HCV genotype 1 received treatment with statins [11]. Another prospective study [12] on 31 patients with chronic hepatitis C infection has shown that fluvastatin alone (in commonly used doses) has a moderate, variable, and short-term antiviral effect. However, the findings of the in vivo studies were not consistent with those of the in vitro studies. In 2007, o’Leary et al. published a prospective study on 10 patients and reported that atorvastatin (in commonly used doses) does not inhibit viral replication [13]. In 2009, Forde et al. [4] published a retrospective study including 6463 HCV seropositive patients; this study showed that statins do not inhibit viral replication in vivo. According to these authors, the discrepancy between the results of the in vivo and in vitro studies may be attributable to several factors; one such factor is the low level of statins in the serum than in the cell cultures, because of the pharmacokinetic properties of statins. All statins, except pravastatin, are largely retained in the first pass through the liver. The in vitro anti-HCV action may be because of an adaptation of the cell cultures that makes the cells sensitive to interferon action and increases their sensitivity to statins. As an adaptive mechanism, HCV could undergo in vivo mutations and become resistant to statins; paradoxically, statins could exert proviral effects by promoting the expression of low-density lipoprotein (LDL) receptors, thereby facilitating HCV penetration into noninfected hepatocytes [4]. Further, the same study showed that triglyceride-reducing agents, such as niacin, may have anti-HCV activity in vivo. There may be a direct relationship between triglyceride level and virus titer, considering that triglycerides metabolism is an intermediate step in the life cycle of HCV. The virus is released together with very low-density lipoprotein (VLDL) particles, and therefore, drugs such as niacin inhibit viral replication by lowering serum triglyceride levels [14][15][16]. Elucidating the role of statins in the treatment of chronic hepatitis C is important, and can be achieved by conducting prospective studies in large groups of patients. extensive research is required to determine the effectiveness of triglyceride-reducing agents for inhibiting HCV replication. Until the approval of new therapeutic agents, the peginterferon–ribavirin combination represented the therapy of choice for chronic viral hepatitis C. Recent data have shown that the addition of protease inhibitors such as boceprevir or telaprevir to the classic peginterferon-ribavirin combination therapy decreases the duration of treatment, thereby reducing the cost of treatment and the number of adverse effects [17][18]. Further, an increase of up to 30% was observed in the sustained virological response rates in non-responders, with naive and genotype 1 HCV infection, and a corresponding increase of up to 40–50% was observed in patients showing relapse [19][20]. These recent advances have shown that statins play a role in improving treatment outcome and increasing the quality of life of HCV patients; however, the exact mechanism underlying their role is yet to be determined.

Videocapsule Endoscopy of the Small Bowel

The most difficult to examine segment of the digestive tract is the small bowel. However, examining the distal portions that follow the duodeno-jejunal junction is vital when trying to diagnose an important number of pathologies, most of them with vital implications for the patient. Until recently, standard diagnostic techniques were limited to radiological barium-enhanced investigations, “push-enteroscopy” and intraoperatory enteroscopy, selective arteriography, scintigraphy or computer tomography. All these methods were either too intrusive, such as the case with intraoperatory enteroscopy, or did not provide sufficient data for an accurate diagnostic. Technological progresses in recent years allowed for the rapid development of novel, more patient-friendly and diagnostically competent investigation techniques dedicated to this particular GI segment. Videocapsule endoscopies (VCE), along with balloon (single or double) enteroscopy are currently considered the two most valuable tools available to the gastroenterologist. (Iddan et al, 2000; Swain P, 2003) The VCE system is currently the most widespread investigation technique for the small bowel, due to its convenience of use and slightly better affordability. It has been tested in a large number of studies, being compared to all other investigatory techniques, currently a large number of high-impact papers existing on the subject. It is estimated that over one million such devices have been swallowed over the course of almost ten years since its first introduction on a global scale.

Comparative study of contour detection methods for intestinal sessile polyps

The past decade represented a step forward in a new direction in the exploration of the small bowel, with the introduction of the wireless capsule endoscopy (WCE). Lesions like intestinal polyps became easier to diagnose in early stages, reducing thus the risk of small bowel cancer. Since the curved shape of polyps represents the most important feature in their automatic identification, proper edge detection techniques are necessary for emphasizing their contour. This paper presents a comparative study of three edge detection methods applied on a set of original and noise processed WCE images containing sessile polyps, based on correct edge localization and a proper contour detection. The oriented Gabor phase congruency method presented better results compared to Sobel and Canny operators, both for original and processed images, recommending it for further use in computer-aided diagnostic systems.

The importance of circulating tumor products as „liquid biopsies” in colorectal cancer

Liquid biopsies represent an array of plasma analysis tests that are studied to evaluate and identify circulating tumor products, especially circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA). Examining such biomarkers in the plasma of colorectal cancer patients has attracted attention due to its clinical significance in the treatment of malignant diseases. Given that tissue samples are sometimes challenging to procure or unsatisfactory for genomic profiling from patients with colorectal cancer, trustworthy biomarkers are mandatory for guiding treatment, monitoring therapeutic response, and detecting recurrence. This review considers the relevance of flowing tumor products like circulating tumor cells (CTCs), circulating tumor DNA (ctDNA), circulating messenger RNA (mRNA), circulating micro RNA (miRNA), circulating exosomes, and tumor educated platelets (TEPs) for patients with colorectal cancer.