Molecular phylogeography of the asp viper Vipera aspis (Linnaeus, 1758) in Italy: evidence for introgressive hybridization and mitochondrial DNA capture.

Owing to its temperature dependence and low vagility, the asp viper (Vipera aspis) is an interesting model species to study the effects of Pleistocene climatic fluctuations on vertebrate genomes. We genotyped 102 specimens from the whole Italian distribution range at three mitochondrial DNA regions (2278 characters, total) and six microsatellite DNA loci (Short Tandem Repeats, STR). The molecular phylogeny was constructed according to Bayesian, Neighbour Joining, Maximum Parsimony and Maximum Likelihood procedures. All methods grouped individuals of the three morphological subspecies (V. a. aspis, V. a. francisciredi, V. a. hugyi) into five different haploclades. Specimens assigned to hugyi clustered in two highly differentiated clades, one being sister group to the complex comprising the second clade of hugyi (i.e., a paraphyletic status), plus two clades of francisciredi. The Bayesian clustering of the STR variability disclosed only two groups, the first including aspis and francisciredi, the second all hugyi. Introgressive hybridization and capture of francisciredi-like lineages in the hugyi mitochondrial genome were suggested to explain the discordance between mitochondrial and nuclear data. The phylogeographic pattern was compatible with population contractions in three glacial refuges. Plausibility of derived hypothesis was checked using coalescence simulations as post hoc tests. Long-term drift and serial founder effects, rather than selection, appeared the main factors affecting the genetic make-up of the Italian asp viper.

Maternal allocation strategies and differential effects of yolk carotenoids on the phenotype and viability of yellow-legged gull (Larus michahellis) chicks in relation to sex and laying order.

Egg quality may mediate maternal allocation strategies according to progeny sex. In vertebrates, carotenoids have important physiological roles during embryonic and post-natal life, but the consequences of variation in yolk carotenoids for offspring phenotype in oviparous species are largely unknown. In yellow-legged gulls, yolk carotenoids did not vary with embryo sex in combination with egg laying date, order and mass. Yolk lutein supplementation enhanced the growth of sons from first eggs but depressed that of sons from last eggs, enhanced survival of daughters late in the season, and promoted immunity of male chicks and chicks from small eggs. Lack of variation in egg carotenoids in relation to sex and egg features, and the contrasting effects of lutein on sons and daughters, do not support the hypothesis of optimal sex-related egg carotenoid allocation. Carotenoids transferred to the eggs may rather result from a trade-off between opposing effects on sons or daughters.

Little Egrets (Egretta garzetta) and trace-metal contamination in wetlands of China.

The rapidly developing Asian countries may face threatening environmental contamination, that however remains largely unassessed. We studied persistent trace elements in three wetlands, Poyang Lake, relatively unpolluted, and Tai Lake, and Pearl River Delta, selected as hotspots of pollution in Central China. We adopted as indicator the Little Egret, a widespread colonial waterbird, and during 1999 and 2000 we collected and analysed the same samples as for a parallel study we conducted in Pakistan, e.g. eggs, body feathers of chicks, prey spontaneously regurgitated by the chicks, and sediments at the areas most used by foraging egrets. The levels of trace-metals at our three study areas were similar, or within the range, of those found in the few other studies for East Asia, with few exceptions. The concentrations of the various elements were below the threshold that may affect the survival or reproduction of the birds, and even the highest concentrations relative to background, i.e. Se in eggs, and Hg in feathers at Pearl Delta, do not pose toxic hazards. In sediments, the levels of trace elements were lower than the critical levels assumed for contaminated soil, except for alarming high levels of As at Poyang. These results do not confirm our expectation, that Poyang was relatively uncontaminated, while Tai and Pearl were polluted. Although trace metal concentration differed significantly among the three study areas, these differences were minor and were not consistent among elements and samples. The bioaccumulation ratios from sediments through prey, feather and egg, were consistent with our previous findings for Pakistan. Only Hg exhibited high bioaccumulation, while Se and Zn had low accumulation, and the other elements no accumulation. This reasserts that feathers of predators such as egrets, may be more sensitive indicators of environmental contamination for the elements subject to bioaccumulation, whereas the sediments or the organisms low in the food chain are better indicators for the other elements.

Tissue damage after acute intoxication by polychlorinated biphenyls in cockroaches.

It is common knowledge that polychlorinated biphenyls (PCBs) represent a serious threat to the health of both vertebrates and invertebrates. As far as the former are concerned, especially as regards human beings, a broad literature describes the direct and indirect effects induced by the PCBs on their systems and organs. Among invertebrates, the information available is mostly related to arthropods and is, however, very scarce. The aim of this work was to evaluate the effects of polychlorinated biphenyls (PCBs) on tissues and organs of individuals belonging to a species of Blattaria (Blattella germanica) treated with various doses of this toxic material. The pathologies found became more serious as the dosage increased and were present throughout the entire digestive system, in the fat body and in the male gonads: in these areas cell and tissue breakdown and severely damaged spermiogenesis were observed. In particular, the testes, Malpighian tubules and fat body accumulated an amorphous basophilic PAS-positive substance. Furthermore, the NOS-dependent NADPH diaphorase activity pattern in the retina and optic lobes was more evident in the treated than in the control insects.

Residues of organochlorinated pesticides in eggs of water birds from Tai Lake in China.

The levels of organochlorine compounds in eggs of water birds from the colony on Tai Lake in China were studied. The eggs were collected in 2000 and belonged to the following species: 65 samples of black-crowned night heron (Nycticorax nycticorax), 36 samples of little egret (Egretta garzetta), 26 samples of cattle egret (Bubulcus ibis) from 13 clutches and 43 samples of Chinese pond heron (Ardeola bacchus) from 17 clutches. Dichlorodiphenyltrichloroethane (DDT) and its derivates (DDE and DDD), hexachlorocyclohexane (HCH) and its isomers (alpha-HCH, beta-HCH, gamma-HCH, delta-HCH), heptachlor, heptachlor epoxide, aldrin, dieldrin, endrin, endrin aldehyde, alpha-endosulfan, beta-endosulfan, and endosulfan sulfate were determined in the laboratory by gas chromatography. The data showed that DDE had the highest levels in all the samples, followed by beta-HCH. The mean levels of DDE among the water bird species were in the order as follows: black-crowned night heron (5464.26 ng/g, dry weight) > Chinese pond heron (2791.12 ng/g, dry weight) > little egret (1979.97 ng/g, dry weight) > cattle egret (660.11 ng/g, dry weight). DDT and its metabolites accounted for 90% of the total organochlorines, except that it was only 73% for cattle egret. The differences of the residue among the bird species were statistically significant and could be attributed to their variations in prey and habitat. Although the DDE burdens in Tai Lake were much lower than 8 microg/g (wet weight) which are thought to have significant adverse effects on black-crowned night herons, they would be expected to increase the risk of adverse effects on survival of chicks of herons and egrets, particularly black-crowned night heron, based on the critical value of 1 microg/g (wet weight) DDE. The burdens of HCHs in this study were higher and the cyclodienes were lower than those found elsewhere.

Egrets as monitors of trace-metal contamination in wetlands of Pakistan.

Environments in Pakistan are subject to increasing pollution, but previous studies were very scanty. During 1999 and 2000, we assessed trace element contamination at three wetlands, Karachi Harbour (with presumed industrial-urban pollution), Taunsa Barrage (agricultural pollution), and Haleji Lake (relatively unpolluted), using as indicators the eggs and the feathers of colonial waterbirds, particularly Little Egrets, their prey, and the sediments collected within their foraging areas. The concentrations of As, Cd, Cr, Pb, Hg, Mn, Se, and Zn were generally within the normal background level, and mostly below the threshold that may affect bird survival or reproduction. However, somewhat high concentrations were found in fish from Karachi, for Pb that was at levels that may harm fish reproduction, and for Hg that was at limit concentration for human consumption. Alarming concentrations were found for Cr and Se in sediments from Karachi, that were above the critical levels for contaminated soil, and Se in eggs, that may affect egret reproduction. The differences among the three wetlands were less marked than hypothesized. The egret species within the same area differed in the concentration of certain elements in their eggs, possibly because females may have foraged in different habitats before breeding, whereas no interspecies difference was found in chick feathers, presumably because their food had been collected in similar habitats around the colony. High bioaccumulation from sediments to organic samples occurred for Hg, while Cd, Se, and Zn exhibited low accumulation; for all these elements, feathers of predatory birds such as the egrets are the best indicators of environmental contamination. On the other hand, As and Cr did not bioaccumulate, and the sediments, or the organisms low in the food chain, like fish or crustaceans, are better indicators of their presence in the environment than predatory birds.

Colour polymorphism in birds: causes and functions.

We studied polymorphism in all species of birds that are presently known to show intraspecific variation in plumage colour. At least three main mechanisms have been put forward to explain the maintenance of polymorphism: apostatic, disruptive and sexual selection. All of them make partly different predictions. Our aims were to investigate evolutionary causes and adaptive functions of colour polymorphism by taking into account a number of ecological and morphological features of polymorphic species. Overall, we found 334 species showing colour polymorphism, which is 3.5% of all bird species. The occurrence of colour polymorphism was very high in Strigiformes, Ciconiiformes, Cuculiformes and Galliformes. Phylogenetically corrected analysis using independent contrasts revealed that colour polymorphism was maximally expressed in species showing a daily activity rhythm extended to day/night, living in both open and closed habitats. All these findings support the hypothesis that colour polymorphism probably evolved under selective pressures linked to bird detectability as affected by variable light conditions during activity period. Thus, we conclude that selective agents may be prey, predators and competitors, and that colour polymorphism in birds may be maintained by disruptive selection.

Bacteriocyte population growth in Blattella germanica.

The number of bacteriocytes with nucleus in the M or S phase was analysed in relation to their rate of increase, throughout two nymphal instars (N1 and N6) of Blattella germanica Linnaeus (Blattaria, Blattellidae). We treated the experimental specimens with colcemid in order to visualize C-metaphases, and with labelled thymidine in order to evidence DNA synthesis in these bacteria-carrying cells. In both young and old nymphs, the C-metaphases showed a similar trend: their average number was only 0.3 per 100 bacteriocytes counted throughout the entire instars. In the young nymphs, the number of bacteriocytes in the S phase was congruent with the frequencies of the C metaphases. Since the number of M or S bacteriocytes was not sufficient to account for the observed increase in number of these endosymbiotic cells during nymphal development, we hypothesize a mechanism of bacterial transmission from bacteriocytes to other fat body cells that may explain the numerical growth of the bacteriocyte population.

Persistent organic pollutants in little egret eggs from selected wetlands in Pakistan.

The main goal of the present work has been to study the use of egret eggs to assess environmental pollution by POPs (HCB, HCHs, cyclodienes, DDTs and PCBs) in three Pakistani wetlands that are presumed to be affected by different types of pollution. Taunsa Barrage, affected mainly by agricultural pollutants; Karachi Harbor because of the supposed exposure to industrial activity-related POPs; and Haleji Lake as a relatively pristine area because of its location in a stony desert. Taunsa Barrage and Haleji Lake are wetlands of international importance according to the Ramsar Convention, while the Karachi Harbor is of interest because of the large human population living there. Eggs of the white ( Egretta garzetta garzetta) and dark ( Egretta garzetta gularis) morphs of Little Egrets were used as monitoring tools. Concentrations were also determined in several prey in this species' diet and in the sediments collected in their foraging areas. Differences in egg pollutant content among the three localities were significant for all the compounds. Overall, the eggs from Haleji Lake and Karachi showed, respectively, the lowest and highest percentages of detection and organochlorine concentrations. Biomagnification from sediments to prey and then to eggs has been documented in the three areas studied and is accompanied by higher percentages of detection of different compounds through the compartments. Differences in the biomagnification factor among the areas were small, even when differences in pollutant concentrations were high, suggesting that eggs are reliable indicators of POPs in the environment. The values found were generally lower than those reported for the eggs of large herons from North America or the Mediterranean basin, and are about the same order of magnitude that those of other medium-sized egrets from other parts of the world.

[Organochlorine residues in eggs of night heron breeding in Yuantouzhu, Wuxi and their functions as bioindicator].

This study analyzed chlorinated pesticides in eggs of night heron breeding in Yuantouzhu, Tai lake. The HCH isomers, DDT, DDD, DDE, endrine and heptachlor epoxide were detected out in egg samples. The residue level and the percent of detection of beta-HCH and p,p'-DDE were significantly high. The mean value of p,p'-DDE was 0.906 microgram/g dry weight. Most of the chlorinated pesticides in samples from Wuxi were higher than those of Gongqing city, Jiangxi province. Oppositely, the hatching rate of night heron egg in Wuxi region was lower than that in Gongqing city. It may be related to the difference of DDE residual levels. Using organochlorine residue in eggs of water-fowls as an indicator for environmental quality assessment is feasible.

Hepatitis C virus (HCV) in lymphocyte subsets and in B lymphocytes expressing rheumatoid factor cross-reacting idiotype in type II mixed cryoglobulinaemia.

The IgMk rheumatoid factors (RF) of type II mixed cryoglobulinaemia (MC) react, in 95% of cases, with MoAbs against the cross-reactive idiotypes (CRI) Cc1 or Lc1 (corresponding to the products of the VH1 and VH4 genes). MC is closely associated with HCV infection, a virus which infects lymphocytes and may replicate in B cells. It has been suggested that HCV may induce clonal selection of B cells producing monoclonal IgMk RF in type II MC. To verify whether HCV is enriched in B cells, and in the subsets expressing Cc1 and Lc1 CRI, we studied peripheral blood lymphocytes from eight patients with MC and HCV RNA-positive sera. Seven patients had RF reacting with anti-Cc1, the other with anti-Lc1 CRI. Total lymphocytes, T cells, B cells, and Cc1+ or Lc1+, Cc1- or Lc1- B cells were purified using MoAb-coated magnetic beads. Lymphocyte subsets were then diluted to give a range of 1 x 106-1 x 103 cells and tested for HCV RNA by reverse transcriptase-polymerase chain reaction. HCV was found exclusively in B cells in seven out of eight patients. In three patients HCV was enriched in the Cc1+ cells. In one of these patients, HCV was found exclusively in Cc1+ cells, with Cc1- cells being HCV-. The data indicate that B cells from type II MC patients are almost constantly infected by HCV. In selected cases, B cell subsets expressing IgMk RF CRI are the prevalent cell type infected by HCV. Our data suggest HCV involvement in B cell dysregulation leading to cryoprecipitable IgMk RF production.

Reproduction and population density affect humoral immunity in bank voles under field experimental conditions.

Density dependence is a common feature in the dynamics of animal populations. Availability of food resources critical to immunity is likely to be one of the mechanisms mediating the effect of population density on individual fitness. The ability to mount an immune response to an antigen is also affected by levels of immunosuppressive hormones associated with reproduction or mediating the response to ecological and social stress. We assessed variation in condition and intensity of humoral immune response to a T-cell-dependent antigen in bank voles (Clethrionomys glareolus) by experimentally altering population density before immunisation. Consistent with our prediction, males had lower humoral immunocompetence in the breeding than in the non-breeding season. Contrary to our expectation, males did not show enhanced immunocompetence and females showed depressed humoral immune response under experimentally lowered population density. Variation of immune response in relation to population density depended on sex, with females but not males showing lower immune response under experimentally reduced density. We conclude that humoral immunity of bank voles was affected by reproduction and social environment rather than by population density.

A case-control study on family history of liver cancer as a risk factor for hepatocellular carcinoma in North Italy. Brescia HCC Study.

OBJECTIVES: We carried out a case-control study to investigate the role of history of liver cancer in a first-degree relative as a risk factor for hepatocellular carcinoma (HCC). METHODS: Two hundred eighty-seven HCC incident cases and 450 subjects unaffected by liver disease (controls) were enrolled in the study. Family history of liver cancer and other malignancies and history of alcohol intake were collected by face-to-face interview. Blood samples were analyzed for HBsAg, anti-HCV and HCV RNA positivity. RESULTS: Family history of liver cancer was associated with HCC (odds ratio [OR] = 2.4; 95% confidence interval [CI] = 1.2-4.7), whereas family history of other malignancies was not (OR = 1.0; 95% CI = 0.61.5). An increased OR for family history of liver cancer was found among subjects negative for the other risk factors (OR = 2.0; 95% CI = 0.6-6.9). A synergism of family history of liver cancer was also evident with hepatitis B and hepatitis C virus infection and with heavy alcohol intake. CONCLUSIONS: This study suggests a role of family history independent from and interacting with known risk factors for hepatocellular carcinoma.

A case-control study on a novel DNA virus (TT virus) infection and hepatocellular carcinoma. The Brescia HCC Study.

We performed a case-control study to evaluate the association of a new human DNA virus named TT virus (TTV) with hepatocellular carcinoma (HCC). We recruited 174 subjects hospitalized for HCC (84% males; mean age: 64 years) and 118 patients hospitalized for non-liver diseases in Brescia, northern Italy, as controls (94% males; mean age: 66 years). TTV DNA was found in serum by polymerase chain reaction (PCR) in 26 cases (15%) and 11 controls (9.3%) (P >. 1). TTV group 2 infection was identified in 16 cases (61.5%) and 4 controls (36.4%) (P >.1) using a type-specific PCR method. Sequence analysis of 222 nt of TTV DNA demonstrated that the remaining 10 cases and 7 controls were all infected by group 1. The odds ratio (OR) for TTV-DNA positivity, adjusted for demographic variables, hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) RNA, and heavy alcohol intake was 1.8 (95% CI: 0.7-4.8; P >.1). The OR did not change when the analysis was restricted to 14 HCC cases and 56 controls who were negative for each known risk factor for HCC (OR = 1.7; 95% CI: 0.8-4.0). TTV-DNA positivity was not associated with transfusion history. The prevalence of TTV DNA was higher among HCC cases positive for HBsAg (10 of 38 [26.3%]) than among those positive for HCV RNA (8 of 62 [12.9%]) or negative for hepatitis B virus (HBV), HCV, and hepatitis G virus (HGV) infections (5 of 62 [8. 1%]) (P =.02). This study does not support the hypothesis of an association between TTV infection and HCC.

Case-control study on hepatitis C virus (HCV) as a risk factor for hepatocellular carcinoma: the role of HCV genotypes and the synergism with hepatitis B virus and alcohol. Brescia HCC Study.

We performed a case-control study to evaluate the risk of hepatocellular carcinoma (HCC) for hepatitis C virus (HCV) infection. A total of 305 newly diagnosed HCC cases (80% males) and 610 subjects (81% males) unaffected by clinically evident hepatic disease admitted to the 2 main hospitals in Brescia, North Italy, were recruited as cases and controls, respectively. Among the 122 HCC cases positive for HCV RNA, genotype 1b was found in 83 patients (68%), genotype 2 in 36 (29.5%) and genotype 1a in 3 (2.5%). Among the controls, 15 were infected with genotype 1b and 15 with type 2. Analysis of HCV envelope 1 nucleotide sequence among 25 cases and 8 controls infected with genotype 2 showed subtype 2c in 96% of cases and in all controls, and subtype 2a in 1 HCC case. The odds ratio (OR) for HCV RNA positivity adjusted for hepatitis B virus (HBV) markers and alcohol intake was 26.3 [95% confidence interval (CI): 15.8-44], and it was higher for genotype 1b (OR = 34.2) than type 2 (OR = 14.4). The OR for HCV RNA was 35.6 (95% CI: 14.5-87.1) when the HBV markers were all negative and 132 (15.3-890) when HBsAg positivity was present; the OR was 26.1 (95% CI: 12.6-54.0) among subjects with alcohol intake of 0-40 g/day and increased to 62.6 (23.3-168) and 126 (42.8-373) with an alcohol intake of 41-80 and >80 g/day, respectively. In conclusion, synergism was found between HCV infection and HBV infection and alcohol intake in causing HCC.

Influence of GB virus-C/hepatitis G virus infection on the long-term course of chronic hepatitis B.

AIMS/BACKGROUND: The clinical significance of GB virus-C/hepatitis G virus (GBV-C/HGV) infection in chronic hepatitis B is not well known and its role in the outcome of liver disease was investigated. METHODS: HGV-RNA and antibody to HGV (anti-E2) were studied in 125 patients with chronic hepatitis B (41 with multiple hepatitis virus exposure), 82 asymptomatic HBsAg carriers and 103 healthy adults. RESULTS: In chronic hepatitis B, HGV-RNA was more frequent in patients with HDV infection and/or anti-HCV positivity than in those without (29% vs 6%, p<0.0001), mainly in drug addicts (38%). At diagnosis the overall prevalence of any marker (HGV-RNA plus anti-E2) was similar in chronic hepatitis due to HBV alone (17%), in HBsAg carriers (16%) and in healthy adults (17%) and increased to 58% in those exposed to HDV and/or HCV. During 1-11 years of follow-up, HGV infection persisted in 70% of patients with chronic hepatitis B. About 400% of HGV persistently coinfected patients underwent sustained biochemical remission, whereas continuing disease activity was observed in 80% of patients who cleared HGV-RNA. CONCLUSIONS: In chronic HBV infection the rate of exposure to HGV is similar to that in healthy adults, except for high risk patients. Long lasting HGV coinfection or anti-E2 seroconversion did not modify the course of chronic hepatitis B.

Clinical significance of hepatic HCV RNA in patients with chronic hepatitis C demonstrating long-term sustained response to interferon-alpha therapy.

Whether sustained biochemical response and absence of serum HCV RNA in the 6-12 months following suspension of interferon-alpha (IFN-alpha) therapy reflect definitive viral clearance in patients with chronic hepatitis C virus (HCV) infection is controversial. To obtain more information on this topic, HCV RNA was sought in both liver and serum samples of 25 long-term responders who were followed for a median period of 39 months (range 21-79) after discontinuation of IFN-alpha. Liver biopsy was undertaken before and 6 to 12 months after IFN-alpha withdrawal. Liver and serum HCV RNA were tested by a nested polymerase chain reaction. Twenty-two patients (88%) tested negative for both liver and serum HCV RNA, two patients had detectable HCV RNA in both liver and serum, and one patient showed persistent HCV RNA only in the liver. Post-treatment liver histology improved markedly in all patients, including those with viral persistence. During further follow-up, biochemical remission was maintained in all patients except one in whom both serum and liver specimens remained HCV RNA positive. The data indicate that the large majority of long-term responders test negative for HCV RNA in the liver, which suggests definitive eradication of HCV RNA infection.

Heavy metal, organochlorine pesticide, and PCB residues in eggs and feathers of herons breeding in northern Italy.

We report on organochlorine pesticide and PCB concentrations in eggs of the little egret, Egretta garzetta, and the black-crowned night-heron, Nycticorax nycticorax, collected in 1993-1994, and on mercury, cadmium, and lead concentrations in feathers of 20-day-old nestlings collected from the same nests in 1994, from heronries near Pavia, northern Italy. Organochlorine pesticide and PCB residues were lower than those commonly associated with mortality and reduced reproductive success. As population levels of the species studied are not declining, these contaminants appear to have no significant adverse effect on reproduction in the heronries studied. DDE levels have decreased markedly in heron eggs since 1978. However, the presence of both DDT and beta-HCH, albeit at low levels, is notable, given that these compounds were banned in Italy in 1978 and 1988, respectively. Relatively high levels of Hg, Cd, and Pb in feathers suggest birds in their colonies are exposed to these contaminants, although both Cd and Pb may relate more to external than to internal contamination.

A case-control study on GB virus C/hepatitis G virus infection and hepatocellular carcinoma. Brescia HCC Study.

A new hepatitis-associated RNA virus of the Flaviviridae family has been identified and named GB virus C/ hepatitis G virus (HGV). We carried out a case-control study to evaluate the association of HGV infection with hepatocellular carcinoma (HCC). We recruited 170 patients hospitalized for HCC (143 male and 27 female, mean age 64 years) and 306 patients hospitalized for nonliver diseases (controls) in Brescia, Italy. HGV RNA was detected by reverse transcription-polymerase chain reaction (RT-PCR) and antibodies against HGV E2 protein (anti-E2) by an immunoassay test. HGV RNA was found in 8 cases (4.7%) and 4 controls (1.3%). The relative risk (RR) for HGV RNA positivity adjusted for demographic variables and hepatitis B surface antigen (HBsAg), hepatitis C virus (HCV) RNA, and alcohol was 7.3 (95% confidence interval, 1.7-30.6; P = .009). No HGV RNA-positive subject was also positive for anti-E2. Anti-E2 prevalence did not differ significantly between cases (20%) and controls (15.3%), and no RR increase was found by this marker. Among subjects with HGV exposure (HGV RNA plus anti-E2 positive), a greater proportion of cases (40%) than controls (14%) had transfusion history. The possible role of HGV in HCC etiology seems modest because the population-attributable risk is lower (4%) than those for HBsAg (22%), HCV RNA (36%), and heavy alcohol intake (52%). This study supports the hypothesis of an association between HGV infection and HCC, although at present there are insufficient data on the causality of the association.