bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of upstream region of hepatitis B virus core gene using in vitro transcription system
Authors: Hiraga Masaharu , Nishizono Akira , Mifune Kumato , Esumi Mariko , Shikata Toshio 
Published: March 2007

AbstractTranscription of the core (C) gene of hepatitis B virus DNA (HBV‐DNA) was studied by an in vitro transcription system using nuclear extracts of human liver cell (HepG2) and non‐liver cell (HeLa) origins. RNA polymerize II‐dependent run‐off transcription of 3.5‐kb (C) mRNA was observed in both nuclear extracts; but the efficiency was much higher in the HepG2 nuclear extract. Analysis of run‐off transcripts using upstream deletion mutants of HBV‐DNA demonstrated that there are two transcription start sites located at approximately nucleotide numbers (nt) 1,797 ± 5 and 1,815 ± 5. This analysis also suggested that the minimum core promoter sequence and a cis‐acting and liver‐specific element for C mRNA transcription are located in the downstream region from ‐80 and ‐110 (Hincll site) of transcription start sites, respectively. DNA‐binding protein assays using synthetic double‐stranded oligonucleotide probes corresponding to three regions in the upstream region (nt from 1,401 to 1,760) of transcription start sites revealed that there are some liver cell‐specific and non‐specific DNA‐binding proteins in both nuclear extracts. The amount of those proteins was generally higher in the HepG2 nuclear extract. However, no obvious correlation was observed in the present study between the presence of DNA‐binding proteins and transcription activity of nuclear extracts in our system. The possible causes of this discrepancy are discussed. © 1994 Wiley‐Liss, Inc.
Novel application of a point mutation assay: Evidence for transmission of hepatitis B viruses with precore mutations and their detection in infants with fulminant hepatitis B
Authors: Hawkins A. E. , Gilson R. J. C. , Beath S. V. , Boxall E. H. , Kelly D. A. , Tedder R. S. , Weller I. V. D. 
Published: March 2007

AbstractMutations of the precore region of hepatitis B virus (HBV) genome have been associated with fulminant and severe chronic hepatitis. However uncertainty remains about the clinical significance and transmissibility of these mutant strains. A point mutation assay (PMA) was developed to identify qualitatively and quantitatively mutations affecting precore amino acids 1 and 28. We have analysed serum samples from six mother‐infant pairs where perinatal transmission of HBV has occurred and where the mothers were HBV carriers without detectable serum HBeAg. In three cases fulminant hepatitis developed in the infant, in two cases acute hepatitis resolved, and in one case the infant was immunised and did not become infected. We also examined serum from a healthcare worker, an anti‐HBe‐seropositive HBV carrier, believed to have transmitted HBV infection to a patient.The PMA results were confirmed in all cases by direct sequencing of polymerase chain reaction (PCR) products using nested and double‐nested PCR with primers to the precore and X region. Precore aa28 mutant‐type virus was detected in the serum of one mother at the time of delivery of three of her children, two of whom developed fulminant hepatitis. Another mother of an infant with fulminant hepatitis had no precore mutations. In one mother‐infant pair a mixed viral population was found; the acute hepatitis B in the infant resolved. The HBV sequence from the healthcare worker was also of aa28 mutant type. No mutations of aa1 were detected in any of the specimens.The study supports the association of precore mutations with some cases of transmission of HBV infection from HBeAg‐negative mothers to their infants. Precore mutations may also be associated with fulminant hepatitis B in infants. Transmission of HBV infection from an HBeAg‐negative healthcare worker may be associated with HBV precore mutation. © 1994 Wiley‐Liss, Inc.
Humoral immune responses and cytomegalovirus excretion in children with asymptomatic infection
Authors: Shen Chen‐Yang , Chang Shu‐Fen , Yang Show‐Lin , Yeh Te‐Shien , Huang Eng‐Shang , Wu Cheng‐Wen 
Published: March 2007

AbstractForty‐two seropositive children aged 3 to 5 years attending a kindergarten were followed up for 1 year in order to examine the relationship between humoral immunity and cytomegalovirus (CMV) excretion status. Anti‐CMV antibodies were measured at the beginning and end of the study by enzyme‐linked immunosorbent assay, neutralizing antibody test, and immunoblot techniques. Among these children, 32 persistently shed virus in urine, 2 intermittently shed CMV, and 4 experienced reactivation during the study. Virus was never isolated from 4 seropositive children. The level of anti‐CMV IgG antibody in seropositive children who remained nonshedders was significantly higher than in children who shed virus during follow‐up. On immunoblots, all seropositive nonshedders reacted to a CMV‐specific 65 kD antigen, whereas most shedders (80%) did not. These findings suggest that humoral immunity plays a role in controlling persistent CMV infection in children with asymptomatic infection. However, the humoral immunity measured by the neutralizing test and the presence of antibodies against CMV‐specific envelope antigens (116 kD/55 kD) apparently play a limited role in modifying persistent excretion and regulating reactivation of latent CMV. Immune evasion by CMV to block these antigens may explain these results. © 1994 Wiley‐Liss, Inc.
RB tumor suppressor gene expression in hepatocellular carcinomas from patients infected with the hepatitis B virus
Authors: Hsia Chu Chieh , di Bisceglie Adrian M. , Kleiner David E. , Farshid Mahmood , Tabor Edward 
Published: March 2007

AbstractHepatitis B virus (HBV) infection is closely associated with the development of hepatocellular carcinoma (HCC), but definite mechanisms by which it could play an etiologic role have not yet been identified. Modifications of the function of the RB tumor suppressor gene, which regulates the cell cycle, could provide such a mechanism. In the present study, the expression of the protein product of RB, pRB, was evaluated by immunohistochemical staining in HCC tissues from 25 patients from China and the United States, adjacent nontumorous liver from 19 of those patients, five human HCC cell lines, three human hepatoblastoma cell lines, and five specimens of normal human liver. Representative samples were also evaluated by western blot. Altered expression of RB was detected in eight HCC tissues (pRB undetectable in five HCCs and detected in <1% of nuclei of HCC cells in three others); all eight had detectable hepatitis B surface or core antigen in the adjacent nontumorous liver, indicating active HBV infection. pRB was detected in 10‐‐95% of nuclei (normal expression) in the remaining 17 HCCs, and in many nuclei in all 19 nontumorous livers, and in the 5 normal livers. No pRB staining was detected in the nuclei of three HCC cell lines, but pRB was detected in > 90% of nuclei of the other HCC and hepatoblastoma cell lines. The relationship of pRB expression to mutations of the p53 tumor suppressor gene was also examined. The absence of detectable nuclear pRB by immunohistochemical staining was associated with the presence of presumed mutant p53 detected by immunohistochemical staining in four out of five HCC cases. In addition, all three HCC cell lines lacking detectable pRB also had a p53 mutation or a p53 deletion. HCCs with altered pRB expression included more grade III and IV tumors (8/8,100%) than did HCCs with normal pRB expression (7/17, 41%) (P < 0.02), suggesting that abnormal pRB expression may be associated with more advanced histologic grades of HCC. These data indicate that interference with the normal function of the tumor suppressor gene RB or its product pRB, often with concomitant p53 mutation, may be one of several mechanisms that contribute to the development or progression of HCC in humans infected with HBV. © 1994Wiley‐Liss, Inc.
HTLV‐I/II infection in a high viral endemic area of Zaire, Central Africa: Comparative evaluation of serology, PCR, and significance of indeterminate Western blot pattern
Authors: Garin Benoî , Gosselin Sylvette , de Thé Guy , Gessain Antoine 
Published: March 2007

AbstractThe frequency of indeterminate Western blot (WB) seroreactivities against HTLV‐I “gag encoded proteins” only, and the use of low specific diagnostic WB criteria led to the overestimation of HTLV‐I seroprevalence in initial studies in intertropical Africa and Papua New Guinea. In order to clarify the meaning of such seroreactivity, 98 blood samples of individuals from a high HTLV‐I endemic area in Zaire, Central Africa were studied by a WB assay containing HTLV‐I disrupted virions enriched with a gp 21 recombinant protein and a synthetic peptide from the gp 46 region (MTA‐1), and by the polymerase chain reaction (PCR) with 3 primers pairs and 4 different HTLV‐I and or HTLV‐II‐specific probes. These 98 samples were taken mainly from patients with neurological diseases and from their relatives. Using stringent WB criteria, 28 sera (29%) were considered as HTLV‐I‐positive, 3 as negative and 67 (68%) as indeterminate. A large proportion of these indeterminate sera would have been considered as HTLV‐I‐positive samples according to previous low specific WB diagnostic criteria. After PCR, 35 samples (36%) were considered as positive for the presence of HTLV‐I proviral DNA. Out of the 67 WB seroindeterminate, 10 (15%) were found HTLV‐I‐positive by PCR. These 10 individuals exhibited in WB multiple band reactivity with p19 and/or p24 (7 cases of both) associated in 6 cases with rgp 21, but never with MTA‐1. No samples were found PCR‐positive for HTLV‐II despite the findings of 11 sera suggestive of HTLV‐II by WB. These findings demonstrate that even in a high HTLV‐I endemic area, only a minority (about 15%) of the WB‐seroinde‐terminate individuals could be considered as infected by HTLV‐I, and that very stringent WB criteria could lead to overlooking some infected individuals. © 1994 Wiley‐Liss, Inc.
Laboratory study of HIV‐1 and HTLV‐I/II coinfection
Authors: Beilke Mark A. , Greenspan Debra L. , Impey Ann , Thompson Jane , Didier Peter J. 
Published: March 2007

AbstractA Retroviral Coinfection Clinic was established in 1991 at Charity Hospital Medical Center of Louisiana to study patients dually infected with human immunodeficiency virus (HIV) and human T lymphotropic virus (HTLV‐I, HTLV‐II). Eight patients were evaluated clinically, and by immunological and virological studies. Multiple neuromuscular diseases were observed, including tropical spastic paraparesis, polymyositis, and polyneuropathies. Only one patient developed AIDS. HIV‐1 infected patients with HTLV‐I, but not HTLV‐II, coinfection have maintained stable CD4 counts, despite the fact that quantitative HIV DNA PCR suggests a relatively high copy number. HTLV‐I/II antigens were detected in lymphocyte cultures from four patients, and lymphoblastoid cell lines have been established from two. These results support the contention that upregulated HTLV‐I/II virus expression and disease manifestations occur during coinfection with HIV, sometimes in association with normal CD4 counts. © 1994 Wiley‐Liss, Inc.
Protective efficacy of hepatitis B vaccines in neonates
Authors: André Francis E. , Zuckerman Arie J. 
Published: March 2007

AbstractA literature search was carried out to investigate the factors that influence the protective efficacy (PE) of hepatitis B vaccines when given to neonates of hepatitis B surface antigen and e antigen positive mothers. Hepatitis B vaccines with either high or low antigen doses are very effective in preventing chronic hepatitis B infection in neonates at risk, but there is evidence that with lower dosages simultaneous use of hepatitis B immune globulin (HBIG) administration is more important than with higher dosages to elicit good protection (PE ≧ 90%). There is also a tendency for lower dosages to confer high PE less consistently, with noticeably greater numbers of chronic surface antigen carriers in neonates who received a complete vaccination course. Furthermore vaccination courses with higher vaccine dosages give high PEs, without concomitant HBIG administration at birth, provided that the first vaccine dose is given at birth and that the second dose follows within 2 months. © 1994 Wiley‐Liss, Inc.
Detection of cytomegalovirus‐matrix protein (pp65) in leukocytes of HIV‐infected patients with painful peripheral neuropathy
Authors: Mastroianni Claudio Maria , Sebastiani Gabriella , Folgori Filippo , Ajassa Camilla , Vullo Vincenzo , Volpi Antonio 
Published: March 2007

AbstractPainful peripheral neuropathy (PPN) in HIV‐infected patients has been increasingly associated with cytomegalovirus (CMV) infection at other sites. In the last few years, the detection of CMV lower matrix phosphoprotein (pp65) antigen in leukocytes has become a major tool in the diagnosis of CMV systemic infection in immunocompromised patients.In this study, CMV antigen detection was assessed in 13 HIV‐infected patients with PPN and, as controls, in 82 HIV seropositive patients without any evidence of peripheral nerve syndromes (10 with CMV retinitis and 72 without CMV endorgan disease). CMV antigenemia was found in 10 (76.9%) patients with PPN, in 5 (6.9%) without CMV disease, and in all 10 patients (100%) with CMV retinitis. Of the 10 PPN patients with CMV antigenemia, only 3 presented with CMV retinitis, while the remaining 7 had no clinical evidence of overt CMV infection at other sites. CMV pp65‐positive cells were also found in three of the four cerebrospinal fluid (CSF) samples collected from PPN patients. Ganciclovir was effective in improving neurological symptoms in two of the four treated patients.The findings suggest that active CMV infection may be associated with PPN in HIV infection even in the absence of CMV disease at other sites. The detection of CMV‐matrix pp65 antigen in the blood and CSF leukocytes could represent a simple and rapid tool of selecting PPN patients for antiviral therapy.
Expression and characterization of a soluble rubella virus E1 envelope protein
Authors: Seto Nina O. L , Gillam Shirley 
Published: March 2007

AbstractIndividual specific antigenic rubella virus (RV) structural proteins are required for accurate serological diagnosis of acute and congenital rubella infections as well as rubella immune status. The RV envelope glycoprotein E1 is the major target antigen and plays an important role in viral‐specific immune responses. The native virion is difficult to produce in large quantities and the protein subunits are also difficult to isolate without loss of antigenicity. The production of a soluble RV E1 (designated E1ΔTm) using the baculovirus‐insect cell expression system is described. In contrast to wild‐type RV E1, the genetically engineered E1ΔTm protein lacks a transmembrane anchor. It behaved as a secretory protein and was secreted abundantly from insect cells. Pulse‐chase studies were used to examine the synthesis, glycosylation, and secretion of E1ΔTm by the insect cells. The secreted E1ΔTm protein was purified from serum‐free medium by onestep immunochromatography. The purified E1ΔTm protein retained full antigenicity and may be a convenient source of E1 protein for use in diagnostic assay and rubella vaccine development.
Analysis of deletion of the integrated human papillomavirus 16 sequence in cervical cancer: A rapid multiplex polymerase chain reaction approach
Authors: Chen Chuan‐Mu , Shyu Mei‐Pyng , Au Lo‐Chun , Chu Hoi‐Weng , Cheng Winston T. K. , Choo Kong‐Bung 
Published: March 2007

AbstractA protocol for a rapid physical mapping of the integrated type 16 human papillomavirus (HPV16) sequences in biospied and paraffin‐embedded archival cervical cancer samples is described. The procedure involves the use of an anchor primer and a mixture of indicator primers in a multiplex polymerase chain reaction (PCR). A minimal conserved region of viral integration of 2,745 bp in length has been mapped between nucleotide (nt) 6102‐941, containing the entire regulatory region and the E6 and E7 open reading frames (ORFs). A general deletion domain of 1,465 bp in the integrated viral genome has been defined between nt 1417–2881, covering most of the E1 ORF at the 3′‐half and 60 bp at the 5′ terminus of the E2 ORF. This common deleted sequence contains an ATPase active domain speculated to be associated with a DNA helicase function essential for the viral replication, and it also falls within the actively spliced E1‐E2 segment of the primary RNA transcripts. Detection of the loss of the 3′‐half of the E1 ORF would be an ideal marker for PCR‐based rapid determination of HPV integration in cervical cancer cells.
Presence of infective Epstein‐Barr virus in the urine of patients with infectious mononucleosis
Authors: Landau Zvi , Gross Raz , Sanilevich Anka , Friedmann Adam , Mitrani‐Rosenbaum Stella 
Published: March 2007

AbstractThe presence of Epstein‐Barr virus (EBV) in the blood and urine of 20 patients with infectious mononucleosis (IM) was investigated together with the clinical course of the disease, and in 9 patients up to 2–7 months after recovery. EBV DNA, analyzed by the polymerase chain reaction (PCR), was detected in the blood of all 20 patients from the first sample obtained and detected between 3 to 42 days from the beginning of symptoms and up to 2–3 months after recovery. In the urine, EBV DNA was detected in 15 out of 16 (93%) patients in the first sample obtained and detected between 3 to 50 days during the clinical course of the disease. In four patients EBV DNA was detected in the urine up to 3 months after full recovery. Seventeen out of 26 (65%) urine samples including 3 which were obtained 2–7 months after recovery infected B cells as assessed by PCR. Nine out of 12 (75%) urine samples tested induced Epstein‐Barr nuclear antigen (EBNA) in the infected B‐cell line. In addition to the persistence of EBV in the blood of IM patients, these studies show for the first time the presence of infective EBV in the urine during the clinical course of the disease and up to 7 months after full clinical recovery. © 1994 Wiley‐Liss, Inc.
Genotypes of hepatitis C virus in chronic liver disease in Taiwan
Authors: Chen Chien‐Hung , Sheu Jin‐Chuan , Wang Jin‐Town , Huang Guang‐Tarn , Yang Pel‐Ming , Lee Hsuan‐Shu , Lee Chia‐Za , Chen Ding‐Shinn 
Published: March 2007

AbstractThe genotypes of hepatitis C virus (HCV) infection in 81 patients with liver cirrhosis (LC) or hepatocellular carcinoma (HCC) were investigated by the polymerase chain reaction using type‐specific primers. All the patients were positive for HCV RNA in the serum. Forty‐two patients had LC with HCC, while the remaining 39 patients had LC without HCC. Genotype II was detected in 47 samples (58.0%), type III in 6 samples (7.4%), and type IV in 4 (6.2%). No evidence of genotype I was found. Mixed infection was detected in 11 samples (13.6%). The prevalence of genotype II in LC with HCC patients (69.0%) was significantly higher (P < 0.05) than in the LC without HCC patients (46.2%). It is concluded that genotype II is the most predominant type in patients with LC or HCC in Taiwan, and is found more frequently in patients who had LC with HCC than in those who had LC alone. © 1994 Wiley‐Liss, Inc.
Hepatitis C virus infection in patients with chronic liver disease or chronic renal failure and blood donors in Thailand
Authors: Luengrojanakul Pairoj , Vareesangthip Kriengsak , Chainuvati Termchai , Murata Kazumoto , Tsuda Fumio , Tokita Hajime , Okamoto Hiroaki , Miyakawa Yuzo , Mayumi Makoto 
Published: March 2007

AbstractHepatitis C virus (HCV) RNA and genotypes, as well as markers of hepatitis B virus infection, were surveyed in 171 patients with chronic liver disease, 276 patients with chronic renal failure, and 961 blood donors in Thailand. HCV RNA was detected in 30 (23%) of 128 patients with nonalcoholic chronic liver disease and hepatitis B surface antigen (HBsAg) in 60 (47%), and both HCV RNA and HBsAg in 3; the cause of liver disease was not established in 41 (32%) patients. HCV RNA was detected in 44 (20%) of 221 patients on maintenance hemodialysis or with kidney transplantation, but in none of 55 patients on peritoneal dialysis. Antibodies to synthetic HCV core peptides were detected in 39 (4.1%) of sera from 961 blood donors, and HCV RNA was detected in 8 (0.8%). Of the 90 HCV RNA samples from patients and donors, genotype V prevailed (46%) followed by II (22%), I (14%), III (3%), and VI (2%); genotypes were not classifiable into any of I‐VI in the remaining 10%. There were six sera which contained HCV RNA, but were without antibody to HCV detectable by the second‐generation enzyme immunoassay. HCV RNA titers were high in four patients with kidney transplantation, but low in one patient with chronic liver disease and one patient on maintenance hemodialysis. HCV RNA at high titer (≥104/ml) was not classifiable in one patient. These results indicate HCV of novel genotypes in Thailand, seronegative HCV infection in patients with kidney transplantation, and a low risk of HCV infection in patients treated by peritoneal dialysis. © 1994 wiiey‐Liss, Inc.
Molecular epidemiology of enterovirus outbreaks in Canada during 1991–1992: Identification of echovirus 30 and coxsackievirus B1 strains by amplicon sequencing
Authors: Drebot Michael A. , Nguan Christopher Y. , Campbell Janice J. , Lee Spencer H. S. , Forward Kevin R. 
Published: March 2007

AbstractThe relatedness of enteroviral isolates associated with two recent outbreaks in Canada was assessed using direct sequencing of amplicons derived from a large portion of the 5′ nontrans‐lated region (NTR) of the viral genome. The amplicons of 60 echovirus 30 isolates originating from seven different provinces in 1991 were found to share 99% or greater sequence identity. Recent coxsackievirus B1 isolates characterised in the same manner were identical to each other. When the 5′ NTR sequence of these isolates was compared to prototype strains a difference of 11–15% in nucleotide composition was observed. These results indicate that the variability of nucleotide sequence found in 5′ NTRs can be utilized to identify rapidly enteroviral strains associated with particular outbreaks and distinguish them from other strains and serotypes. © 1994 Wiley‐Liss, Inc.
Development and preliminary evaluation of an enzyme immunosorbent assay for the detection of adenovirus type 8
Authors: Wood S. R. , Sharp I. R. , de Jong J. C. , Verweij‐Uijterwaal M. W. 
Published: March 2007

AbstractEpidemic keratoconjunctivitis (EKC) is a highly contagious adenoviral ocular infection which can occur in outbreaks and is predominantly caused by adenovirus type 8 (Ad8). Detection and typing of this virus after isolation is generally by serum neutralisation or more complex molecular techniques. These methods can be time consuming particularly during outbreaks. Therefore, an Ad8 specific antigen capture enzyme immunosorbent assay (EIA) was developed as a rapid and cost effective diagnostic method for laboratories.An Ad8 type‐specific monoclonal antibody was used in a direct antigen capture method and an anti‐hapten fluorescein isothiocyanate (FITC)‐anti‐FITC system. Assay configuration studies indicate that the system in which a type specific capture antibody and a group specific detector antibody are used provides greater sensitivity to the assay than a system using a group specific monoclonal or polyclonal capture antibody. Also, this allows the use of the same detector antibody with varying type specific capture antibodies on the solid phase.In a preliminary evaluation of the two formats, the direct antigen capture assay and the FITC‐anti‐FITC system had a sensitivity of 98.75% and 100%, respectively, with a specificity of 100%. However, these results are not statistically significant due to the low numbers of Ad8 and other viral isolates obtained from eye swabs.The direct EIA format has been shown to be able to detect different Ad8 genome types including four isolated from four epidemics of EKC in Brest, France, the Ad8 prototype strain, and some DNA‐variant isolates which had not been typed by restriction endonuclease analysis (REA). © 1994 Wiley‐Liss, Inc.