bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of portal pressure in the severity of bleeding in portal hypertensive rats
Authors: Castañeda Beatriz , Debernardi-Venon Wilma , Bandi Juan-Carlos , Andreu Victoria , Pérez-del-Pulgar Sofía , Moitinho Eduardo , Pizcueta Pilar , Bosch Jaime
Published: July 2004

The aim of this study was to investigate the role of portal hypertension determining the severity of bleeding in portal hypertensive rats. The effects of section of branches of the ileocolic vein were studied in sham-operated (SO), partial portal vein-ligated (PPVL), and common bile duct-ligated (CBDL) rats. The ensuing hemorrhage was compared with that caused by section of femoral vein, where the portal hypertensive factor is excluded. In PPVL rats, section of branches of increasing size (divided into fourth, third, second, and first order) resulted in increasingly severe bleeding (arterial pressure: ↓ ± 4%, ↓6 ± 12%, ↓15 ± 8%, and ↓28 ± 13%; P < .005; hematocrit ↓4 ± 2%, ↓6 ± 1%, ↓7 ± 2%, and ↓10 ± 4%; P < .005). Bleeding from first-order branches was mild in SO, moderate in PPVL, and severe in CBDL rats, as shown by increasing changes in arterial pressure (↓3 ± 3%, ↓12 ± 16% and, ↓43 ± 23%; P < .01), hematocrit (↓4 ± 1%, ↓12 ± 2%, and ↓32 ± 19%; P < .01), and mortality (0%, 0%, and 56%; P < .001). Greater blood loss in CBDL rats was associated with higher portal pressure (16.6 ± 2.7 vs. 13.1 ± 1.1 mm Hg in PPVL; P < .01) and more prolonged bleeding time (70 ± 4 vs. 35 ± 3 seconds in PPVL; P < .001). Vessels were similarly dilated in CBDL and PPVL (0.7 ± 0.2 and 0.7 ± 0.1 vs. 0.4 ± 0.1 mm in SO; P < .05). Section of femoral vein caused equal blood loss in SO, PPVL, and CBDL rats, assessed by falls in hematocrit (↓8 ± 2%, ↓7 ± 1%, ↓8 ± 1%, respectively; NS) and by the blood loss (3.6 ± 0.7, 3.5 ± 0.9, and 3.8 ± 0.7 g; NS). The study shows that the degree of portal pressure elevation is a major determinant of the severity of portal hypertension-related bleeding in PPVL and CBDL rats.
Gene therapy of hepatocellular carcinoma in vitro and in vivo in nude mice by adenoviral transfer of the escherichia coli purine nucleoside phosphorylase gene
Authors: Mohr Leonhard , Shankara Srinivas , Yoon Seung-Kew , Krohne Tim U. , Geissler Michael , Roberts Bruce , Blum Hubert E. , Wands Jack R.
Published: July 2004

Expression of viral or bacterial enzymes in tumor cells to convert nontoxic prodrugs into highly toxic metabolites is an attractive gene-therapeutic approach for the treatment of hepatocellular carcinoma (HCC). The Escherichia coli purine nucleoside phosphorylase (PNP) converts purine analogs into freely diffusible metabolites, which are highly toxic to dividing and nondividing cells. We investigated the antitumor effects of PNP in the human HCC cell lines, HepG2, Hep3B, and HuH-7, and performed a comparison with herpes simplex thymidine kinase (TK). The genes for PNP, TK, and enhanced green fluorescent protein (EGFP) were delivered to HCC cells by identical adenoviral vectors. Fludarabine and ganciclovir (GCV) served as prodrugs for PNP and TK, respectively. Expression of PNP highly sensitized HCC cells to fludarabine treatment. Fludarabine concentrations between 0.5 and 1 μg/mL killed 100% of the cells expressing PNP with no detectable toxicity in control cells expressing EGFP. Expression of PNP in as few as 10% of HCC cells induced efficient killing of most bystander cells. Expression of TK followed by GCV treatment produced a potent growth inhibition but failed to kill all TK-expressing HCC cells. More importantly, the TK system exhibited a lower degree of bystander effect. Adenoviral delivery of PNP followed by fludarabine administration prevented subcutaneous and intrahepatic tumor formation in nude mice and was also effective for the treatment of established tumors. These results demonstrate the potential of the PNP/fludarabine system for the treatment of HCC.
Clonal expansion in evolution of chronic hepatitis to hepatocellular carcinoma as seen at an X-chromosome locus
Authors: Ochiai Toshiya , Urata Yoji , Yamano Takeshi , Yamagishi Hisakazu , Ashihara Tsukasa
Published: July 2004

Clonal analysis has shown that hepatocellular carcinoma arises from a single cell. However, the clonality of precancerous lesions and adjacent nonneoplastic tissues is not clear. We analyzed a human androgen receptor locus to elucidate the clonal state of liver tissues including post-hepatitic lesions associated with hepatocarcinogenesis. The analysis was based on a restriction fragment length polymorphism involving an androgen receptor locus on the X chromosome, taking advantage of physiologic random inactivation by methylation of 1 of 2 X chromosomes in females during embryogenesis. Clonality was assessed in 79 randomly located tissue samples microdissected from noncirrhotic liver, including a total of 40 morphologically normal sites in 4 normal livers and 39 sites from a single HCV-infected liver. In addition, 51 regenerative nodules, 4 areas of adenomatous hyperplasia, and 18 hepatocellular carcinomas were sampled. All samples were obtained from livers involved by various neoplasms. Eight of forty samples (20.0%) from the four normal livers and 20 of the 39 samples (51.3%) from the single HCV-infected liver showed a monoclonal pattern. Moreover, 30 of 51 regenerative nodules (58.9%) showed a monoclonal pattern. No histologic differences were evident between mono- and polyclonal nodules. On the other hand, the 18 carcinomas and 4 areas of adenomatous hyperplasia all were monoclonal. Mean calculated monoclonal areas of normal liver and liver with chronic hepatitis were 1.1 and 3.3 mm2. Our results suggest that areas representing a single clone of hepatocytes are present in normal liver, and these progressively expand as changes advance from chronic hepatitis to hepatocellular carcinoma.
In situ determination by surface chemiluminescence of temporal relationships between evolving warm ischemia-reperfusion injury in rat liver and phagocyte activation and recruitment
Authors: Cutrìn Juan Carlos , Boveris Alberto , Zingaro Barbara , Corvetti Giovanna , Poli Giuseppe
Published: July 2004

Liver ischemia-reperfusion is characterized by an increased oxygen-dependent free radical chain-reaction rate and an increased steady-state concentration of reactive oxygen species. The aim of this study was to evaluate the in situ generation of reactive oxygen species and its relationship with phagocyte activation and recruitment in reperfused rat liver. Rat livers were subjected to 2 hours of selective lobular ischemia and reperfusion for up to 12 hours. The following parameters were determined: in situ liver chemiluminescence, understood to reflect the tissue steady-state concentration of singlet oxygen (1O2); myeloperoxidase tissue activity; the number of neutrophils; and the degree of necrosis. An early chemiluminescence burst was measured after 30 minutes of blood reflow (early phase of oxidative stress), followed by a relapse and a further increase after 4 to 12 hours of reperfusion (late phase of oxidative stress). Both early and late phases were modified by pretreatment with gadolinium chloride (GdCl3), pointing to a key role of the Kupffer cells. Neutrophils infiltrated into the liver, myeloperoxidase activity, in situ chemiluminescence, and necrosis were found to be strongly correlated over the 4- to 12-hour reperfusion period (r = .960; average of the 4 correlation coefficients). Together with resident phagocytes, neutrophil recruitment and activation appear to provide a major contribution to the increase of oxygen-dependent free-radical reactions and amplification of liver reperfusion damage. Surface chemiluminescence appears to properly describe the in situ and in vivo progressive organization of the acute inflammatory response with phagocyte-mediated liver injury.
Altered hepatic lymphocyte subpopulations in obesity-related murine fatty livers: Potential mechanism for sensitization to liver damage
Authors: Guebre-Xabier Mimi , Yang ShiQi , Lin Hui Zhi , Schwenk Robert , Krzych Ursula , Diehl Anna Mae
Published: July 2004

Although obesity-related fatty livers are vulnerable to damage from endotoxin, the mechanisms involved remain obscure. The purpose of this study was to determine if immunologic priming might be involved by determining if fatty livers resemble normal livers that have been sensitized to endotoxin damage byPropionibacterium acnesinfection. The latter induces interleukin (IL)-12 and -18, causing a selective reduction of CD4+NK T cells, diminished IL-4 production, deficient production of T-helper type 2 (Th-2) cytokines (e.g., IL-10), and excessive production of Th-1 cytokines (e.g., interferon gamma [IFN-γ]). Liver and spleen lymphocyte populations and hepatic cytokine production were compared in genetically obese, ob/ob mice (a model for obesity-related fatty liver) and lean mice. Obese mice have a selective reduction of hepatic CD4+NK T cells. Serum IL-18 is also increased basally, and the hepatic mRNA levels of IL-18 and -12 are greater after endotoxin challenge. Thus, up-regulation of IL-18 and IL-12 in fatty livers may reduce hepatic CD4+NK T cells. In addition, mononuclear cells from fatty livers have decreased expression of the adhesion molecule, leukocyte factor antigen-1 (LFA-1), which is necessary for the hepatic accumulation of CD4+NK T cells. Consistent with reduced numbers of hepatic CD4+NK T cells, mononuclear cells from fatty livers produce less IL-4. Furthermore, after endotoxin treatment, hepatic induction of IL-10 is inhibited, while that of IFN-γ is enhanced. Thus, fatty livers have inherent immunologic alterations that may predispose them to damage from endotoxin and other insults that induce a proinflammatory cytokine response.
Oral tolerization ameliorates liver disorders associated with chronic graft versus host disease in mice
Authors: Nagler Arnon , Pines Mark , Abadi Uri , Pappo Orit , Zeira Michael , Rabbani Elazar , Engelhardt Dean , Ohana Meir , Chowdhury Namita Roy , Chowdhury Jayanta Roy , Ilan Yaron
Published: July 2004

In chronic graft versus host disease (cGVHD), an immune attack by transplanted donor lymphocytes results in damage of host target organs. A disbalance between proinflammatory (Th1) and anti-inflammatory cytokines (Th2) plays an important role in the pathogenesis. Immune hyporesponsiveness induced by oral antigen administration has been shown to suppress autoimmunity. We evaluated the efficacy of oral tolerization in preventing cGVHD in a mouse model. cGVHD was generated by infusing 2.5 × 107 splenocytes from B10.D2 donor mice, to sublethally irradiated (6 Gy) BALB/c recipient mice, which differ in minor histocompatibility antigens. The transplantation resulted in cGVHD, with characteristic hepatic and small bowel inflammation, and increased skin collagen content and fibrosis. Oral tolerance was induced by feeding donor B10.D2 mice with proteins extracted from BALB/c splenocytes at 50 μg/d per mouse for 11 days before transplantation. Tolerization was evidenced by reduction in mixed lymphocyte response of effector splenocytes from tolerized B10.D2 mice against BALB/c target splenocytes. Liver and small bowel biopsy specimens revealed much less inflammation. Oral tolerization prevented weight and subcutaneous fat loss, reduced thickening, and skin collagen deposits. Reduction of collagen α1 (I) gene expression was shown by in situ hybridization. Serum interleukin 10 (IL-10) levels measured significantly higher in tolerized mice than in controls, whereas interferon gamma (IFN-γ), IL-2, and tumor necrosis factor α (TNF-α) were reduced significantly. Oral tolerization of splenocyte donors towards recipient-strain splenocytes ameliorated cGVHD of the liver, small intestine, and skin. A cytokine shift from a proinflammatory to an anti-inflammatory pattern may play a role in down-regulation of the immune-mediated target organ damage.
Activation of nuclear factor κB in hepatitis C virus infection: Implications for pathogenesis and hepatocarcinogenesis
Authors: Tai Dar-In , Tsai Sun-Lung , Chen Young-Mao , Chuang Yen-Ling , Peng Cheng-Yuan , Sheen I-Shyan , Yeh Chau-Ting , Chang Kenneth S. , Huang Shao-Nan , Kuo George C. , Liaw Yun-Fan
Published: July 2004

The hepatitis C virus (HCV) core protein is a multifunctional protein. It may bind to the death domain of tumor necrosis factor receptor 1 (TNFR1) and to the cytoplasmic tail of lymphotoxin-β receptor, implying that it may be involved in the apoptosis and anti-apoptosis signaling pathways. In vitro studies have been inconclusive regarding its ability to inhibit or enhance TNF-α-induced apoptosis. To address this issue, electrophoretic mobility shift assay (EMSA) and immunohistochemical studies were used to show the activation of nuclear factor κB (NF-κB) in HCV-infected liver tissues and in HCV core-transfected cells. The activation of NF-κB was correlated with the apoptosis assays. The results showed that NF-κB activation could be shown in HCV-infected livers and HCV core-transfected cells. The data of EMSA correlated with those of immunohistochemical studies, which revealed a higher frequency of NF-κB nuclear staining in HCV-infected than in normal livers. NF-κB activation conferred resistance to TNF-α-induced apoptosis in HCV core-transfected cells. Inhibition of NF-κB activation by pyrrolidine dithiocarbamate sensitized them to TNF-α-induced apoptosis. These findings suggest that HCV infection may cause anti-apoptosis by activation of NF-κB and implicate a mechanism by which HCV may evade the host’s immune surveillance leading to viral persistence and possibly to hepatocarcinogenesis.
Zonal down-regulation and redistribution of the multidrug resistance protein 2 during bile duct ligation in rat liver
Authors: Paulusma Coen C. , Kothe M. J. , Bakker Conny T. , Bosma Piter J. , van Bokhoven Irene , van Marle Jan , Bolder Ulrich , Tytgat Guido N. , Elferink Ronald P.
Published: July 2004

We have studied regulation of the multidrug resistance protein 2 (mrp2) during bile duct ligation (BDL) in the rat. In hepatocytes isolated after 16, 48, and 72 hours of BDL, mrp2-mediated dinitrophenyl-glutathione (DNP-GS) transport was decreased to 65%, 33%, and 33% of control values, respectively. The impaired mrp2-mediated transport coincided with strongly decreased mrp2 protein levels, without any significant changes inmrp2RNA levels. Restoration of bile flow after a 48-hour BDL period resulted in a slow recovery of mrp2-mediated transport and protein levels. Immunohistochemical detection of the protein in livers of rats undergoing BDL showed strongly reduced mrp2 staining after 48 hours, which was initiated in the periportal areas of the liver lobule and progressed toward the pericentral areas after 96 hours. Immunofluorescent detection of mrp2 in livers of rats undergoing 48 hours of BDL revealed decreased staining accompanied by intracellular localization of the protein in pericanalicular vesicular structures. Within this intracellular compartment, mrp2 colocalized with the bile salt transporter (bsep) and was still active as shown by vesicular accumulation of the fluorescent organic anion glutathione-bimane (GS-B). We conclude that down-regulation of mrp2 during BDL-induced obstructive cholestasis is mainly posttranscriptionally regulated. We propose that this down-regulation is caused by endocytosis of apical transporters followed up by increased breakdown of mrp2, probably in lysosomes. This breakdown of mrp2 is more severe in the periportal areas of the liver lobule.
Mutations of the core promoter and response to interferon treatment in chronic replicative hepatitis B
Authors: Erhardt Andreas , Reineke Ulf , Blondin Dirk , Gerlich Wolfram Hubert , Adams Ortwin , Heintges Tobias , Niederau Claus , Häussinger Dieter
Published: July 2004

In chronic replicative hepatitis B the significance of mutations in the basic core promoter (BCP), core upstream regulatory sequences (CURS) and negative regulatory element (NRE) for response to interferon (IFN) is unknown. A sequence analysis of the NRE, CURS, BCP, and precore region was performed from sera of 96 patients with chronic replicative hepatitis B (64 hepatitis B e antigen [HBeAg]-positive patients and 32 HBeAg-negative patients) treated with alfa-IFN (IFN-α). The overall sustained response (SR) rate to IFN was 30% with no significant difference between HBeAg-positive and HBeAg-negative patients. IFN responsiveness correlated to hepatitis B virus (HBV)-DNA levels, hepatitis B surface antigen (HBsAg) levels, the number of mutations in the complete BCP, especially nucleotide (nt) region 1753 to 1766 and mutations at nt 1762 and 1764. In HBeAg-positive hepatitis, SR to IFN was associated with a high number of mutations in the BCP (P < .04) and nucleotide region 1753 to 1766 (P < .015) as well as mutations at nucleotide 1764 (P < .007). In HBeAg-negative hepatitis, SR to IFN correlated with a low number of mutations in the BCP (P < .04) and nucleotide region 1753 to 1766 (P < .02) and a wild-type sequence at nt 1764 (P < .003). Prediction of IFN response was possible on the basis of nt 1764 in 77% of HBeAg-positive patients and 78% of HBeAg-negative patients. IFN response did not correlate with the occurrence of the 1896 mutation, mutations in the CURS or NRE, disease duration, ethnic origin of the patient, alanine transaminase (ALT) levels and HBV genotype. Our data suggest that HBV genome mutations located within the BCP are determinants of a response to IFN therapy.
Iron reduction before and during interferon therapy of chronic hepatitis C: Results of a multicenter, randomized, controlled trial
Authors: Fontana Robert J. , Israel Jonathan , LeClair Paula , Banner Barbara F. , Tortorelli Kristina , Grace Norman , Levine Robert A. , Fiarman Gale , Thiim Michael , Tavill Anthony S. , Bonkovsky Herbert L.
Published: July 2004

Patients with chronic hepatitis C and low serum and hepatic iron stores may have an improved response to interferon (IFN). We tested whether iron reduction before and during IFN therapy would lead to an improved sustained biochemical and virological response compared with IFN alone. Eighty-two previously untreated patients with chronic hepatitis C were randomized to either: group A IFN-α2b 3 MU 3 times per week for 6 months, or group B iron reduction before and during IFN-α2b 3 MU 3 times per week for 6 months. Group B patients had lower mean serum alanine transaminase (ALT) levels than group A patients during treatment and follow-up. Group B patients had significantly lower mean hepatitis C virus (HCV)-RNA levels at treatment weeks 4 and 12 (P < .05). Serum HCV RNA was undetectable at the end of treatment in 15 group B patients compared with 7 group A patients (P = .03); 7 group B patients and 3 group A patients had persistently undetectable serum HCV RNA 24 weeks after the end of therapy (P = .20). Paired pre- and posttreatment liver biopsies in 18 group B patients demonstrated significant improvements in 2 of the 3 inflammation scores of the Knodell histological activity index (P < .05). No changes occurred in the paired biopsies from 15 group A patients. We conclude that iron reduction via therapeutic phlebotomy improves the end-of-treatment virological and histological response to short-term IFN therapy. Additional studies are needed to determine if iron reduction in combination with higher doses or longer duration of IFN may be of benefit.
Characteristics of hepatitis C viral genome associated with disease progression
Authors: Nagayama Kazuyoshi , Kurosaki Masayuki , Enomoto Nobuyuki , Miyasaka Yuka , Marumo Fumiaki , Sato Chifumi
Published: July 2004

The clinical presentations of chronic hepatitis C are not uniform. Some patients show persistently high serum alanine transaminase (ALT) values and develop liver cirrhosis and hepatocellular carcinoma (HCC), whereas serum ALT values stay normal in other patients. The mechanism causing this diversity remains to be elucidated. The aim of this study was to identify genomic characteristics of hepatitis C virus (HCV) genotype 1b associated with disease progression. Full length sequences of HCV were determined in 14 patients who showed persistently normal serum ALT values (normal ALT group) and 13 cirrhotics with HCC (HCC group). Residues in which amino acid usage was different between these 2 groups were extracted, and Progression score was defined as the total number of residues with 7 amino acids, more frequently present in the HCC group than in the normal ALT group. In the validation of this Progression score in 9 patients with normal ALT and 25 with HCC, the score was significantly higher in the HCC group (3.1 ± 1.1 vs. 2.0 ± 0.9, P= .019). Finally, the correlation between the score and clinical markers related to disease progression was analyzed. In a total of 107 patients with chronic HCV infection, the Progression score was correlated significantly with platelet counts (r= −0.31, P= .0024) by multivariate analysis. In conclusion, high Progression scores were associated with the presence of HCC and low platelet counts. Sequences of the HCV-1b genome may be related to the progression of chronic hepatitis C.
Prevalence and clinical course of chronic hepatitis C virus (HCV) infection and rate of HCV vertical transmission in a cohort of 15,250 pregnant women
Authors: Conte Dario , Fraquelli Mirella , Prati Daniele , Colucci Alice , Minola Eliseo
Published: July 2004

The prevalence and natural course of chronic hepatitis C virus (HCV) infection was evaluated in 15,250 consecutive pregnant women. The rate of HCV vertical and perinatal transmission was also assessed. The presence of anti-HCV was tested by means of EIA III and confirmed by recombinant immunoblot assay III. Alanine transaminase (ALT), anti-human immunodeficiency virus (HIV), and HCV-RNA were tested during the first month and third trimester of pregnancy, and 6 months after delivery; the same tests were made in all of the newborns of anti-HCV-positive mothers at birth (on cord blood samples) and then at 4-month intervals. Anti-HCV positivity was found in 370 cases (2.4%), 72% of whom were also HCV-RNA-positive. The proportion of women with hypertransaminases decreased from 56.4% at the first examination during the first month of pregnancy to 7.4% in the last trimester, and then increased again after delivery (54.5%), without any concomitant changes in the proportion of those with viremia. The proportion of anti-HCV- and HCV-RNA-positive newborns was 5.1% after 1 year (8 of 155), all of whom had the same genotype as their mother. The rate of HCV transmission was not affected by the type of delivery or feeding, or the HIV status of the mother. The results of this large-scale study confirm previous data in smaller series concerning the prevalence of HCV infection in pregnant women, and strongly support the hypothesis of a favorable (possibly immunomediated) effect of pregnancy on liver cell necrosis in anti-HCV-positive women.
Risk factors for hepatitis C virus infection in United States blood donors
Authors: Murphy Edward L. , Bryzman Stephen M. , Glynn Simone A. , Ameti Dannie I. , Thomson Ruth A. , Williams Alan E. , Nass Catharie C. , Ownby Helen E. , Schreiber George B. , Kong Fanhui , Neal Keith R. , Nemo George J.
Published: July 2004

Injection drug use (IDU) is a known risk factor for hepatitis C virus (HCV) infection, but the strength of other parenteral and sexual risk factors is unclear. In 1997, we performed a case-control study of 2,316 HCV-seropositive blood donors and 2,316 seronegative donors matched on age, sex, race/ethnicity, blood center, and first-time versus repeat-donor status. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated using conditional logistic regression. Questionnaires were returned by 758 (33%) HCV+ and 1,039 (45%) control subjects (P = .001). The final multivariate model included only the following independent HCV risk factors: IDU (OR = 49.6; 95% CI: 20.3-121.1), blood transfusion in non-IDU (OR = 10.9; 95% CI: 6.5-18.2), sex with an IDU (OR = 6.3; 95% CI: 3.3-12.0), having been in jail more than 3 days (OR = 2.9; 95% CI: 1.3-6.6), religious scarification (OR = 2.8; 95% CI: 1.2-7.0), having been stuck or cut with a bloody object (OR = 2.1; 95% CI: 1.1-4.1), pierced ears or body parts (OR = 2.0; 95% CI: 1.1-3.7), and immunoglobulin injection (OR = 1.6; 95% CI: 1.0-2.6). Although drug inhalation and a high number of lifetime sex partners were significantly more common among HCV seropositives, they were not associated with HCV after controlling for IDU and other risk factors. IDU, blood transfusion among non-IDU, and sex with an IDU are strong risk factors for HCV among United States blood donors. Weaker associations with incarceration, religious scarification, being stuck or cut with a bloody object, pierced ears or body parts, and immunoglobulin injection must be interpreted with caution.
Hepatitis B e antigen-negative chronic hepatitis b in Hong Kong
Authors: Chan Henry L. Y. , Leung Nancy W. Y. , Hussain Munira , Wong May L. , Lok Anna S. F.
Published: July 2004

Hepatitis B e antigen-negative chronic hepatitis B (e−CHB) has been reported in Asia but its prevalence and clinical significance have not been determined. The aims of this study were to determine the prevalence of e−CHB in Hong Kong and the frequency of precore and core promoter mutations in these patients. A cross-sectional study was performed in 350 consecutive Chinese patients (230 men and 120 women; mean age ±SD, 42 ± 13 years) with chronic hepatitis B virus infection. A total of 243 (69%) patients were hepatitis B e antigen (HBeAg)-negative of whom 15% had clinical cirrhosis. In the remaining 85% of patients, 63% had normal and 22% had elevated transaminases. Serum hepatitis B virus (HBV) DNA was detectable using branched DNA assay in 46% of HBeAg-negative patients with clinical cirrhosis/elevated transaminases. Forty-five percent of the patients with e−CHB had the precore stop codon mutation, and an additional 41% had core promoter changes. There was no correlation between the presence of precore/core promoter mutations and liver disease or HBV-DNA levels. Overall, 17% of HBeAg-negative patients were viremic and had evidence of chronic liver disease (e−CHB) with mean HBV-DNA levels comparable with that in HBeAg-positive patients. In summary, we found that e−CHB may be present in up to 17% of HBeAg-negative patients seen in a tertiary referral center in Hong Kong. e−CHB may be a heterogenous condition and is not invariably associated with the precore HBV mutant. Population studies are needed to determine the true prevalence of e−CHB in Asia and to assess its natural course and response to treatment.
Inhibition of hepatitis C virus (HCV)-RNA-dependent translation and replication of a chimeric HCV poliovirus using synthetic stabilized ribozymes
Authors: Macejak Dennis G. , Jensen Kristi L. , Jamison Sharon F. , Domenico Kristal , Roberts Elisabeth C. , Chaudhary Nilabh , von Carlowitz Ira , Bellon Laurent , Tong Myron J. , Conrad Andrew , Pavco Pamela A. , Blatt Lawrence M.
Published: July 2004

Ribozymes are catalytic RNA molecules that can be designed to cleave specific RNA sequences. To investigate the potential use of synthetic stabilized ribozymes for the treatment of chronic hepatitis C virus (HCV) infection, we designed and synthesized hammerhead ribozymes targeting 15 conserved sites in the 5′ untranslated region (UTR) of HCV RNA. This region forms an internal ribosome entry site that allows for efficient translation of the HCV polyprotein. The 15 synthetic ribozymes contained modified nucleotides and linkages that stabilize the molecules against nuclease degradation. All 15 ribozymes were tested for their ability to reduce expression in an HCV 5′ UTR/luciferase reporter system and for their ability to inhibit replication of an HCV-poliovirus (HCV-PV) chimera. Treatment with several ribozymes resulted in significant down-regulation of HCV 5′ UTR/luciferase reporter expression (range 40% to 80% inhibition, P < .05). Moreover, several ribozymes showed significant inhibition (>90%, P < .001) of chimeric HCV-PV replication. We further show that the inhibitory activity of ribozymes targeting site 195 of HCV RNA exhibits a sequence-specific dose response, requires an active catalytic ribozyme core, and is dependent on the presence of the HCV 5′ UTR. Treatment with synthetic stabilized anti-HCV ribozymes has the potential to aid patients who are infected with HCV by reducing the viral burden through specific targeting and cleavage of the viral genome.
The past incidence of hepatitis C virus infection: Implications for the future burden of chronic liver disease in the United States
Authors: Armstrong Gregory L. , Alter Miriam J. , McQuillan Geraldine M. , Margolis Harold S.
Published: July 2004

Because chronic liver disease may develop many years after acute hepatitis C virus (HCV) infection, the past incidence of acute infections is a major determinant of the future burden of HCV-associated complications. We estimated past incidence of acute HCV infection using national seroprevalence data and relative age-specific incidence data from a sentinel counties surveillance system. Projections of the future prevalence of HCV-infected patients were derived from models that included an 85% drop in HCV infection incidence as observed for reported cases in the early 1990s. The models showed a large increase in the incidence of HCV infections from the late 1960s to the early 1980s. The degree of increase was dependent on the assumed rate of antibody loss; a model with 2.5% annual antibody loss showed annual incidence increasing from 45,000 infections (95% confidence interval [95% CI]: 0-110,000) in the early 1960s to 380,000 infections (95% CI: 250,000 to 500,000) in the 1980s. Projections showed that although the prevalence of HCV infection may be declining currently because of the decline in incidence in the 1990s, the number of persons infected for ≥20 years could increase substantially before peaking in 2015. If the incidence of new HCV infections does not increase in the future, persons born between 1940 and 1965 will be at highest lifetime risk of acquiring the infection.
Local properties of a functionally graded interphase between cementum and dentin
Authors: Ho Sunita P. , Balooch Mehdi , Marshall Sally J. , Marshall Grayson W.
Published: July 2004

The study of natural interfaces may provide information necessary to engineer functionally graded biomaterials for bioengineering applications. In this study, the mechanical, structural, and chemical composition variations associated with a region between cementum and dentin were studied with the use of nanoindentation, microindentation, optical microscopy, and Raman microspectroscopy techniques. Three‐millimeter‐thick transverse sections (N = 5) were obtained from the apical one‐third of the roots of sterilized human molars. The samples were ultrasectioned at room temperature with the use of a diamond knife and an ultramicrotome. Longitudinal ground sections of 100 μm thickness were prepared and stained with von Kossa stain to determine the mineralized regions within the molar roots. Raman microspectroscopy was used to determine the relative inorganic content, mainly apatite (POν1 mode at 960 cm−1) and organic content, mainly collagen (CH stretch at 2940 cm−1) between cementum and dentin bulk tissues. The microindentation and nanoindentation results indicated a gradual transition in hardness from cementum to dentin over a width ranging from 100 to 200 μm. However, the variation in hardness data for cementum and dentin by nanoindentation was larger (0.62 ± 0.21, 0.77 ± 0.14 GPa) than from microindentation (0.49 ± 0.03, 0.69 ± 0.07 GPa). Within the 100 to 200 μm region there was a 10 to 50 μm fibrillar hydrophilic cementum–dentin junction (CDJ) with mechanical properties significantly lower than either the cementum or the dentin side of CDJ. Light microscopy revealed a 100 to 200 μm translucent region between cementum and dentin. Raman microspectroscopy results showed a variation in organic and inorganic composition 80 to 140 μm wide. It was concluded that a morphologically and biomechanically different CDJ lies within a wider cementum–dentin interphase. Hence, cementum, dentin, and the interphase can be classified as a functionally graded dental tissue within the root of a tooth. © 2004 Wiley Periodicals, Inc. J Biomed Mater Res 70A: 480–489, 2004
Effects of culture pH on the production of bioactive polysaccharides by Agaricus blazei in batch cultures
Authors: Shu Chin‐Hang , Lin Ko‐Jung , Wen Bor‐Jiun
Published: July 2004

The effects of culture pH on the production, molecular weight distribution and the bioactivity of polysaccharides produced by Agaricus blazei were evaluated by four pH‐controlled batch cultures. As the culture pH of each batch was controlled from 4.0 to 7.0, the maximum polysaccharide concentration increased from 561 to 1252 mg dm−3, but the average molecular weight of the polysaccharides decreased monotonically from 1080 kDa to 600 kDa, the relative amount of β‐glucan from 56% to 33%, and the TNF‐α release by macrophage cells from 1440 to 760 pg per 5 × 104 cells. Polysaccharides with higher molecular weights, β‐glucan contents and bioactivities were obtained in the submerged cultures of Agaricus blazei at lower culture pH but with lower yields. Copyright © 2004 Society of Chemical Industry
Modelling and optimisation of a chemical industry wastewater treatment plant subjected to varying production schedules
Authors: Van Hulle Stijn WH , Vanrolleghem Peter A
Published: July 2004

Industrial wastewater treatment plants (WWTPs) have to provide 100% reliability and availability for the discharging facilities at an industrial site. Varying production schedules at these facilities and specific components occurring in the industrial wastewater considerably hinder the optimisation of industrial WWTPs. In this context it is shown in this paper that model‐based optimisation is an efficient and cost‐reducing way to ensure that an industrial WWTP functions well. The aim of the study presented was two‐fold. The first step was to show the usefulness of a proposed procedure to build and calibrate a model for the industrial WWTP. The second objective was to use the model for optimisation of the WWTP. As an example, a large set of possible production schedules in the different discharging facilities was simulated. Based on these simulations it could be predicted which schedules allow the effluent standards to be met and which do not. The calibrated and validated model was also used to investigate different operating strategies such as the in‐series operation of the two available aeration tanks. In fact, with the model it was shown that a 20% reduction of the degradable COD concentration in the effluent could be achieved by operating the tanks in series instead of in parallel. This case study shows how the approach presented can lead to fast and cost effective modelling and optimisation of an industrial WWTP. Copyright © 2004 Society of Chemical Industry
Analysis of carbon dioxide gas/liquid mass transfer in aerated stirred vessels using non–Newtonian media
Authors: Gómez‐Díaz Diego , Navaza José M
Published: July 2004

Gas/liquid mass transfer has been investigated in an aerated stirred tank using non‐Newtonian media and carbon dioxide as absorbent and gas phase respectively. The volumetric mass transfer coefficients at different operational variables have been measured. The non‐Newtonian media (liquid phases) used were aqueous solutions of two polymers, carboxymethyl cellulose and alginate sodium salts. The influence upon the mass transfer of the rheological properties, polymer concentration, stirring rate and gas flow rate was studied. Kinematic viscosity and density experimental data were used to calculate the average molecular weight corresponding to the polymers employed. Reasonable agreement was found between the predictions of proposed models and the experimental data. The results shown in the present paper allow us to understand carbon dioxide transfer to a non‐Newtonian liquid phase and to evaluate the effect of the liquid phase characteristics. The equations used in this paper allow accurate simulation of the transfer of a pure gas to a rheologically complex solution. Copyright © 2004 Society of Chemical Industry
Batch production of L(+) lactic acid from whey by Lactobacillus casei (NRRL B‐441)
Authors: Büyükkileci Ali O , Harsa Sebnem
Published: July 2004

The effects of temperature, pH, and medium composition on lactic acid production by Lactobacillus casei were investigated. The highest lactic acid productivity values were obtained at 37 °C and pH 5.5. The productivity was 1.87 g dm−3 h−1 at 37 °C in shake flasks. In the fermenter, a productivity of 3.97 g dm−3 h−1 was obtained at pH 5.5. The most appropriate yeast extract concentration was 5.0 g dm−3. Whey yielded a higher productivity value than the analytical lactose and glucose. Initial whey lactose concentration did not affect lactic acid productivity. MnSO4 ·H2O was necessary for lactic acid production by L casei from whey. Product yields were approximately 0.93 g lactic acid g lactose−1. Copyright © 2004 Society of Chemical Industry
The Mts1/S100A4 protein is a neuroprotectant
Authors: Pedersen Martin V. , Køhler Lene B. , Grigorian Mariam , Novitskaya Vera , Bock Elisabeth , Lukanidin Eugine , Berezin Vladimir
Published: July 2004

Mts1 (S100A4) is a calcium‐binding protein of the EF‐hand type, belonging to the S100 family of proteins. The mts1/S100A4 gene was originally isolated from tumor cell lines, and the protein is believed to play an important role in tumor progression. More recently, oligomeric, but not dimeric, forms of Mts1 have been shown to have a neuritogenic effect when added extracellularly to hippocampal neurons. Here we show increased neurite outgrowth in two other cell types, dopaminergic and cerebellar neurons, in response to treatment with Mts1 oligomers. Moreover, we demonstrate that Mts1 acts as a neuroprotectant in primary cerebellar, dopaminergic, and hippocampal neurons induced to undergo cell death. Interestingly, the survival of the cerebellar and hippocampal neurons increased as a result of treatment with Mts1 not only in oligomeric form but also—although to a lesser extent—in dimeric form. The inhibition of death in cerebellar neurons by Mts1 was accompanied by an inhibition of DNA fragmentation, but Mts1 did not affect the activity of caspases‐3 and ‐6. In hippocampal neurons, cell death induced by the amyloid‐β peptide (Aβ25–35) was characterized by an increase in caspase‐3 and ‐6 activity, but no DNA fragmentation was observed. As in cerebellar neurons, the induced increase in caspase activity in hippocampal neurons was not affected by Mts1. © 2004 Wiley‐Liss, Inc.
Delayed neurotrophic treatment preserves nerve survival and electrophysiological responsiveness in neomycin‐deafened guinea pigs
Authors: Yamagata Takahiko , Miller Josef M. , Ulfendahl Mats , Olivius N. Petri , Altschuler Richard A. , Pyykkö Ilmari , Bredberg Göran
Published: July 2004

Benefits of cochlear prostheses for the deaf are dependent on survival and excitability of the auditory nerve. Degeneration of deafferented auditory nerve fibers is prevented and excitability maintained by immediate replacement therapy with exogenous neurotrophic factors, in vivo. It is important to know whether such interventions are effective after a delay following deafness, typical for the human situation. This study evaluated the efficacy of brain‐derived neurotrophic factor (BDNF) and ciliary neurotrophic factor axokine‐1 analogue (CNTFAx1) application, 2 or 6 weeks postdeafening, in preventing further degeneration and a decrease in excitability. Guinea pigs were deafened and implanted with intracochlear stimulating electrodes, a scala tympani cannula‐osmotic pump system, and auditory brainstem response (ABR) recording electrodes. Subjects received BDNF + CNTFAx1 or artificial perilymph (AP) treatment for 27 days, beginning at 2 or 6 weeks following deafening. Electrical (E) ABR thresholds increased following deafening. After 1 week, in the 2‐weeks‐delayed neurotrophic factor treatment group, EABR thresholds decreased relative to AP controls, which were statistically significant at 2 weeks. In the 6‐week delay group, a tendency to enhanced EABR sensitivity began at 2 weeks of treatment and increased thereafter, with a significant difference between neurotrophic factor‐ and AP‐treated groups across the treatment period. A clear, statistically significant, enhanced survival of spiral ganglion cells was seen in both neurotrophic factor treatment groups relative to AP controls. These findings demonstrate that BDNF + CNTFAx1 can act to delay or possibly even reverse degenerative and, likely apoptotic, processes well after they have been activated. These survival factors can rescue cells from death and enhance electrical excitability, even during the period of degeneration and cell loss when the spiral ganglion cell population is reduced by >50% (6 weeks). It is noteworthy that this same degree of ganglion cell loss, secondary to receptor damage, is typically observed after a period equivalent to some years of deafness in humans. © 2004 Wiley‐Liss, Inc.
Ferulic acid: pharmaceutical functions, preparation and applications in foods
Authors: Ou Shiyi , Kwok Kin‐Chor
Published: July 2004

Ferulic acid (4‐hydroxy‐3‐methoxycinnamic acid), an effective component of Chinese medicine herbs such as Angelica sinensis, Cimicifuga heracleifolia and Lignsticum chuangxiong, is a ubiquitous phenolic acid in the plant kingdom. It is mainly conjugated with mono‐ and oligosaccharides, polyamines, lipids and polysaccharides and seldom occurs in a free state in plants. Ferulic acid is a phenolic acid of low toxicity; it can be absorbed and easily metabolized in the human body. Ferulic acid has been reported to have many physiological functions, including antioxidant, antimicrobial, anti‐inflammatory, anti‐thrombosis, and anti‐cancer activities. It also protects against coronary disease, lowers cholesterol and increases sperm viability. Because of these properties and its low toxicity, ferulic acid is now widely used in the food and cosmetic industries. It is used as the raw material for the production of vanillin and preservatives, as a cross‐linking agent for the preparation of food gels and edible films, and as an ingredient in sports foods and skin protection agents. Ferulic acid can be prepared by chemical synthesis and through biological transformation. As polysaccharide ferulate is a natural and abundant source of ferulic acid, preparation of ferulic acid from plant cell wall materials will be a prospective pathway. Copyright © 2004 Society of Chemical Industry
Laparoscopic surgery after orthotopic liver transplantation
Authors: Merenda Roberto , Gerunda Giorgio E. , Neri Daniele , Barbazza Franco , Di Marzio Enrico , Meduri Franco , Valmasoni Michele , Faccioli Alvise Maffei
Published: July 2004

Laparoscopic surgery is currently a widely accepted approach to several surgical fields because of its advantages in terms of postoperative pain reduction and easy patient recovery. This approach may be useful even in solid-organ transplantation surgery as a diagnostic or treatment procedure in some surgical complications. From July 1991 to December 1998, we performed 142 liver transplantations on 129 patients. During the postoperative period, many complications occurred. Here we report two cases of intestinal occlusion caused by adhesions and three cases of lymphocele, all approached with laparoscopic surgery. In all cases but one, we were able to complete the surgery by laparoscopic means; in one of the two occlusions, the procedure was switched to laparotomy because of a choledochojejunal anastomosis lesion. The three cases of lymphocele must be considered in a particular manner because such cases, to our knowledge, have never been described in the literature. They always presented with a late-onset right pleural effusion and were located in the retrohepatic, retrogastric, and left paracaval areas, close to the esophageal hiatus. In conclusion, we believe a laparoscopic approach is a useful strategy to solve some surgical complications in patients who underwent orthotopic liver transplantation; however, the use of laparoscopic surgery in this field is strictly connected to the surgeon’s experience and versatility.
Needle-tract implantation from hepatocellular cancer: Is needle biopsy of the liver always necessary?
Authors: Takamori Ryan , Wong Linda L. , Dang Collin , Wong Livingston
Published: July 2004

Percutaneous needle biopsies are frequently used to evaluate focal lesions of the liver. Needle-tract implantation of hepatocellular cancer has been described in case reports, but the true risk for this problem has not been clearly defined. We retrospectively reviewed 91 cases of hepatocellular cancer during a 4-year period from 1994 to 1997. Data on diagnostic studies, therapy, and outcome were noted. Of 91 patients with hepatocellular cancer, 59 patients underwent percutaneous needle biopsy as part of their diagnostic workup for a liver mass. Three patients (5.1%) were identified with needle-tract implantation of tumor. Two patients required en bloc chest wall resections for implantation of hepatocellular cancer in the soft tissues and rib area. The third patient, who also received percutaneous ethanol injection of his tumor, required a thoracotomy and lung resection for implanted hepatocellular cancer. Percutaneous needle biopsy of suspicious hepatic lesions should not be performed indiscriminately because there is a significant risk for needle-tract implantation. These biopsies should be reserved for those lesions in which no definitive surgical intervention is planned and pathological confirmation is necessary for a nonsurgical therapy.

(Liver Transpl 2000;6:67-72.)
Influence of human fulminant hepatic failure sera on endogenous retroviral expression in pig hepatocytes
Authors: Nyberg Scott L. , Hibbs Jonathan R. , Hardin Joseph A. , Germer Jeffrey J. , Platt Jeffrey L. , Paya Carlos V. , Wiesner Russell H.
Published: July 2004

A porcine endogenous retrovirus (PERV) has been shown to infect human embryonic kidney 293 (HEK293) cells in vitro. The PERV proviral sequence exists in the genome of all porcine cells, including hepatocytes used in a bioartificial liver (BAL). We examined the possibility of PERV infection in HEK293 cells during exposure to supernatant from cultured pig hepatocytes. Pig hepatocytes were cultured in media supplemented with serum from patients in fulminant hepatic failure (FHF) to simulate conditions of an extracorporeal BAL. Pig hepatocytes were cultured in serum-free media for 24 hours and then exposed to fresh medium containing serum from a patient with FHF (22 patients tested). Twenty-four hours later, supernatant was collected and analyzed by polymerase chain reaction (PCR), with and without reverse transcriptase. Primers targeting the pol gene of PERV were used for PCR. Products of amplification were detected by an enzyme-linked immunosorbent assay-based technique using an internal capture probe also targeting the pol gene. Levels of PERV sequences were estimated by serial dilution. All positive samples were tested for infectivity in HEK293 cells. Porcine kidney 15 cell supernatant and fresh culture media were studied as positive and negative controls, respectively. Pig hepatocytes were also studied in the absence of FHF sera and in the presence of mitogenic stimulation with phytohemagglutinin (PHA) and phorbol 12-myristate-13-acetate (PMA). PERV DNA and PERV RNA were detected in all supernatants of cultured pig hepatocytes. The level of PERV RNA in the supernatant of pig hepatocytes was not altered by exposure to human FHF serum or stimulation with PHA and PMA. In addition, PERV RNA was undetectable in the supernatant of HEK293 cells for up to 50 days after exposure to pig hepatocyte supernatant (with or without FHF sera). These findings show that production of PERV by cultured pig hepatocytes was unaffected by exposure to growth factors and cytokines present in human FHF sera.