Aleksandra Knezevic

Risk factors for hepatocellular carcinoma: a case-control study in Belgrade (Serbia).

Aims and background The objective of this case-control study was to test the existing hypotheses about factors related to the occurrence of hepatocellular carcinoma in the population of Belgrade (Serbia). Methods and study design The investigation was conducted between 2004 and 2007 and consisted of 45 newly diagnosed, histologically confirmed hepatocellular carcinoma patients and 90 individually gender- and age-matched hospital controls. Conditional univariate and multivariate logistic regression analyses were applied. Results A highly statistically significant association (P = 0.001) was demonstrated between hepatocellular carcinoma and HBsAg positivity and the presence of hepatitis C virus antibodies. Diabetes mellitus was significantly (P = 0.018) associated with an increased risk of hepatocellular carcinoma. A statistically significant inverse association was shown between low parity and the risk of hepatocellular carcinoma (P = 0.033). The risk increased significantly with a longer history of cigarette smoking (P = 0.044), as well as the daily consumption of hard liquor (P = 0.049). A weekly intake of fish (P = 0.003) and yogurt (P = 0.003) and daily intake of boiled vegetables (P = 0.001) were reported more frequently by controls than hepatocellular carcinoma cases. In the current study, a high intake of salty food also significantly increased the risk of hepatocellular carcinoma (P = 0.027). Based on multivariate analysis, the presence of hepatitis C virus antibodies (OR = 24.6, P = 0.001) and duration of smoking ≥25 years (OR = 3.8, P = 0.020) were significantly related to hepatocellular carcinoma, whereas the daily consumption of boiled vegetables (OR = 0.1, P = 0.011) was inversely associated with the risk of hepatocellular carcinoma. Conclusions The findings obtained in the current study support the hypotheses that non-viral factors, such as lifestyle factors, reproductive factors, and a history of diabetes, might be involved in the etiology of hepatocellular carcinoma. Free full text available at www.tumorionline.it

Prevalence of oral herpes simplex virus reactivation in cancer patients: a comparison of different techniques of viral detection.

BACKGROUND Oral reactivation of latent Herpes simplex virus (HSV) infection may easily occur in cancer patients. Virus reactivation can cause oral mucosa damage, worsen already existing lesions caused by stomatotoxic effect of cancer therapy and, whether symptomatic or asymptomatic, ample spreading and promote viral transmission. METHODS Polymerase chain reaction (PCR), cell-culture and direct immunofluorescence have been used to determine the frequency of oral HSV reactivation in 60 patients undergoing chemotherapy for different malignancies. RESULTS By means of PCR, the presence of viral DNA was detected in 71.7% of patients prior to chemotherapy and in 85.0% after chemotherapy. 33.3% of patients before and 40.0% after chemotherapy were viral-culture positive, while 3.3% of patients before and 11.7% after chemotherapy were positive as shown by direct immunofluorescence. No significant difference in HSV-1 reactivation was found before and after chemotherapy. In addition, no significant difference was found when comparing HSV-1 reactivation in patients with and without mucositis. HSV-2 was not detected in any of the patients. CONCLUSIONS Reactivation of latent HSV is exceptionally frequent in cancer patients. The results of this study suggest that virus reactivation occurs independently of cancer chemotherapy. The potential role of HSV reactivation in oral mucosa damage remains unclear.

mTOR-independent autophagy counteracts apoptosis in herpes simplex virus type 1-infected U251 glioma cells.

We investigated the role of autophagy, a stress-inducible lysosomal self-digestion of cellular components, in modulation of herpes simplex virus type 1 (HSV-1)-triggered death of U251 human glioma cells. HSV-1 caused apoptotic death in U251 cells, characterized by phosphatidylserine externalization, caspase activation and DNA fragmentation. HSV-1-induced apoptosis was associated with the induction of autophagic response, as confirmed by the conversion of cytosolic LC3-I to autophagosome-associated LC3-II, increase in intracellular acidification, presence of autophagic vesicles, and increase in proteolysis of the selective autophagic target p62. HSV-1-triggered autophagy was not associated with the significant increase in the expression of proautophagic protein beclin-1 or downregulation of the major autophagy suppressor mammalian target of rapamycin (mTOR). Moreover, the phosphorylation of mTOR and its direct substrate p70 S6 kinase was augmented by HSV-1 infection, while the mTOR stimulator Akt and inhibitor AMPK-activated protein kinase (AMPK) were accordingly activated and suppressed, respectively. An shRNA-mediated knockdown of the autophagy-essential LC3β, as well as pharmacological inhibition of autophagy with bafilomycin A1 or 3-methyladenine, markedly accelerated apoptotic changes and ensuing cell death in HSV-1-infected glioma cells. These data indicate that AMPK/Akt/mTOR-independent autophagy could prolong survival of HSV-1-infected U251 glioma cells by counteracting the coinciding apoptotic response.

Disseminated Neonatal Herpes Caused by Herpes Simplex Virus Types 1 and 2

Disseminated neonatal herpes simplex virus (HSV) infection is characterized by progressive multiple organ failure and high mortality rates. It can result from infection with either HSV-1 or HSV-2. We report a case of disseminated neonatal herpes that was caused by HSV-1 and HSV-2.

Human Cytomegalovirus and Epstein-Barr Virus Genotypes in Apical Periodontitis Lesions

INTRODUCTION Different genotypes of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) possess specific pathogenic abilities because of various interactions with the hosts immune system and differences in cell tropism. The aim of this study was to determine the distribution of HCMV and EBV genotypes in apical periodontitis lesions in relation to their clinical and histopathologic features. METHODS One hundred samples of apical periodontitis lesions and 25 control samples (healthy pulp tissue) were collected. The presence of HCMV glycoprotein B (gB) and EBV nuclear antigen-2 genotypes was analyzed by nested polymerase chain reaction and restriction fragment length polymorphisms analysis. RESULTS EBV and HCMV were detected in apical periodontitis lesions at significantly higher frequencies than in healthy pulp controls (P = .020 and P = .020, respectively). HCMV gB type II was significantly more frequent compared with gB type I in the examined groups (P = .036). No HCMV gB type III or IV products were found. In both periapical lesions and controls, EBV-1 occurred more often compared with EBV-2 (P = .001). Dual EBV and HCMV coinfection was more frequently detected in large-size periapical lesions (P = .038). CONCLUSIONS Both HCMV and EBV are associated with inflammatory processes of periapical bone destruction. HCMV gB type II and EBV-1 are the most prevalent genotypes in apical periodontitis lesions.

Pro-inflammatory cytokine levels in human apical periodontitis: Correlation with clinical and histological findings

This study aimed to compare the levels of tumour necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and interleukin-6 (IL-6) between apical periodontitis lesions with different clinical and histological features. Based on clinical data and history of disease, 100 human apical periodontitis lesions were categorised as either asymptomatic or symptomatic lesions. According to histological examination, lesions were divided into periapical granulomas and radicular cysts. Pulp tissues of 25 impacted wisdom teeth were used as controls. Homogenised tissue samples were centrifuged and supernatants were used for the determination of cytokine levels by enzyme-linked immunosorbent assay. Significantly higher levels of IL-1β and IL-6 were found in symptomatic lesions compared with asymptomatic lesions and control tissues (P < 0.001, P < 0.001, respectively). The concentration of IL-1β was significantly higher in radicular cysts compared with periapical granulomas (P = 0.003). Symptomatic lesions, as judged by high local production of IL-1β and IL-6, represent an immunologically active stage of the disease.

Epstein-Barr virus infection induces bone resorption in apical periodontitis via increased production of reactive oxygen species

Chronic inflammatory processes in periapical tissues caused by etiological agents of endodontic origin lead to apical periodontitis. Apart from bacteria, two herpesviruses, Epstein-Barr virus (EBV) and Human cytomegalovirus (HCMV) are recognized as putative pathogens in apical periodontitis. Although previous reports suggest the involvement of EBV in the pathogenesis of apical periodontitis, its exact role in periapical bone resorption has not yet been fully elucidated. We hypothesize that EBV infection in apical periodontitis is capable of inducing periapical bone resorption via stimulation of reactive oxygen species (ROS) overproduction. Increased levels of ROS induce expression of receptor activator of nuclear factor kappa B (NF-κB) ligand (RANKL). RANKL binding to receptor activator of nuclear factor κB (RANK) present on the surface of preosteoclasts induces their maturation and activation which consequently leads to bone resorption. The potential benefit of antiviral and antioxidant-based therapies in periapical bone resorption treatment remains to be assessed.

Distribution of JC Virus Genotypes Among Serbian Patients Infected With HIV and in Healthy Donors

Certain factors lead to increased reactivation of JC virus (JCV) and immunodeficiency seems to be the most important. JCV isolates can be classified into eight different genotypes and several subtypes based on nucleotide difference in the VP1 gene. JCV genotypes are strongly associated with particular ethnic groups and frequently used as genetic markers for human evolution and migration. The aim of this study was to determine the frequency of JCV urinary shedding and genotype distribution in Serbia among patients infected with HIV and healthy donors. Urine samples from 107 healthy donors and 93 patients infected with HIV were collected. PCR followed by sequence analysis was carried out using primers specific for VP1 and NCRR of the virus genome. Excretion rate of JCV‐DNA in urine was higher in patients infected with HIV than in healthy donors (44.1% vs. 31.7%) although statistical significance was not found. Within the group infected with HIV, the degree of immunosuppression (measured by CD4+ cell count) did not influence JCV excretion rate. Sequence analysis of JCV NCRR from both patients infected with HIV and healthy donors showed a pattern identical to archetype structure. In healthy Serbian donors the predominant genotype was 1 (41.2%), followed by 4 (32.4%) and 2 (26.4%). On the other hand, genotype distribution pattern was different in patients infected with HIV: 2 (43.9%), 1 (31.7%), and 4 (24.4%). This study showed that European, Eurasian, and Indian types are circulating in Serbia and that distribution corresponds to the origin of the inhabitants of Serbia. J. Med. Virol. 86:411–418, 2014.

Herpesviral Infection in Periapical Periodontitis

Purpose of ReviewThis review describes the most recent findings on herpesviral infections and offers current concepts of herpesviral role in the pathogenesis of periapical periodontitis.Recent FindingsThirty articles reported data on herpesviral infection in periapical periodontitis. Epstein-Barr virus and human cytomegalovirus are the most frequently detected herpesviruses in periapical samples. The main hypothesis postulates a bidirectional herpesviral-bacterial relationship in the etiopathogenesis of periapical periodontitis. A high heterogeneity of herpesviruses incidence was registered within the studies, in part, due to various methodological approaches used in laboratory testing, different inclusion criteria, study design, seroprevalence of herpesviruses, and sociodemographic characteristics of investigated populations.SummaryHerpesviruses have been shown to potentially impair local host defense in periapical tissue. Although it has been demonstrated that endodontic pathogenic bacteria are able to reactivate herpesviruses, further, in vitro studies should provide more data on herpesviruses as a factor in the pathogenesis of the periapical pathoses. It is, therefore, necessary to investigate potential benefits of antiviral therapy in well-designed controlled longitudinal studies.