bluuebunny/crossref_metadata_2025 huggingface dataset:
Astrocytic reaction predominance in chronic encephalitis of junin virus‐infected rats
Authors: Lascano Eduardo F. , Berría María I. , Avila María M. , Weissenbacher Mercedes C.
Published: March 2007

Junin virus antigen distribution and astrocytic reaction to prolonged infection were characterized in rat brain by the PAP technique. During the acute stage of neurologic disease following intracerebral inoculation, Junin antigen was detected in 100% of animals, strongly in most neurons but also to a much lesser degree in scattered astrocytes, dropping to 20% of rats at 540 days postinfection. Initially labeled in all brain areas, viral antigen gradually disappeared from hippocampus but persisted irregularly in cerebral cortex, basal ganglia, Purkinje cells, pons, and medulla oblongata. Such a pattern suggests that specific neuronal subpopulations, in spite of apparently unaltered cell morphology, may persistently harbor the virus, leading on occasion to a delayed neurologic syndrome. During both the acute and chronic stages of disease, a mild inflammatory exudate was observed, characterized by the presence of T and B lymphocytes, as well as macrophages and unidentified round cells. GFAP immunostaining showed increased astrocytic reaction as infection lapsed into chronicity. Corpus callosum, hippocampus, and cerebellum exhibited the sharpest reactive astrocytosis, followed by basal ganglia, pons, and medulla oblongata, whereas in cerebral cortex it was considerably less. Astrocyte activation, which failed to correlate with viral antigen presence in neurons, seems to result from a generalized condition, possibly including diffusible brain factors triggered by viral infection. Such widespread astroglial reaction may thus contribute to the outcome of the late neurologic syndrome.
Riboprobe assay for HDV RNA: A sensitive method for the detection of the HDV genome in clinical serum samples
Authors: Smedile Antonina , Bergmann Katherine F. , Baroudy Bahige M. , V. Wells Frances , Purcell Robert H. , Bonino Ferruccio , Rizzetto Mario , Gerin John L.
Published: March 2007

We have used a new hybridization assay for the detection of the genome of hepatitis delta virus (HDV) in serum using a strand‐specific RNA probe obtained by transcription of a recombinant riboprobe. This assay was tested on a panel of 30 sera from HBsAg carriers with hepatitis delta antigen (HDAg) in the liver. The riboprobe assay detected HDV RNA in the serum of 83% of the patients, while 63% were positive using the DNA hybridization assay. HDAg was detected in 73% of the same sera by immunoblotting. The riboprobe assay was also compared to other assays on serial samples from an experimentally infected chimpanzee. These results demonstrate that the Northern blot assay using the RNA probe is more sensitive than the homologous DNA probe for the detection of HDV in serum and is also more sensitive than the immunoblot assay for HDAg. The riboprobe assay is the most sensitive of currently available methods to measure HD viremia.
Serological evidence that dry heating of clotting factor concentrates prevents transmission of non‐A, non‐B hepatitis
Authors: Skidmore S. J. , Pasi K. J. , Mawson S. J. , Williams M. D. , Hill F. G. H.
Published: March 2007

A new test for antibodies specific for an agent causing non‐A, non‐B hepatitis (NANBH) was used to screen 45 children with coagulation disorders who received factor concentrates. It was found that the test results correlated with clinical evidence of NANBH and that heat treatment of concentrates (80°C for 72 hours) appears to have prevented transmission of NANBH.
Antibody responses in recipients of varicella vaccine assayed by immunoblotting
Authors: Harper David R. , Kangro Hillar O. , Heath Raymond B.
Published: March 2007

Sera taken from 35 children with cancer who had been vaccinated with live varicella vaccine were assayed using immunoblotting for the presence of IgG class antibodies to proteins present in varicella‐zoster virus (VZV)‐infected cells. Sera from 23 of these patients were also assayed for IgM class antibodies.

The patterns of immunoreactivity observed for these patients following vaccination were substantially weaker and more variable than those detected following natural VZV infection in otherwise healthy individuals. The IgG responses detected following vaccination involved up to 10 protein bands between 28 and 188 kDa. Bands were particularly frequent in the 78–96 kDa region. IgM responses involved up to 10 bands between 28 and 114 kDa, with the bands in the 78–96 kDa region and at 32–36 kDa being detected most frequently.

Repeated vaccination generally produced a stronger IgG antibody response than did single vaccination, and subsequent exposure of vaccinees to natural VZV infection resulted in an increased level of reactivity for IgG antibodies, but not for IgM. Similar reaction patterns were obtained with sera from vaccinees when the vaccine virus and wild‐type VZV were used as antigens.

Immunoblotting showed good correlation with indirect radioimmunoassay for the detection of a vaccine‐induced IgG response.
Mother to infant transmission of hepatitis C virus infection
Authors: Wejstål R. , Hermodsson S. , Iwarson S. , Norkrans G.
Published: March 2007

Eight women with chronic hepatitis C virus (HCV) infection during pregnancy gave birth to 11 children. Five of these children had elevated ALT, but only two had increased levels in more than one sample. All children tested before 6 months of age were positive for anti‐HCV at most up to 7 months of age and then became negative. One child with a maximum ALT level of 8.4 μkat/I however, regained anti‐HCV positivity at 12 months of age, and a liver biopsy at 21 months of age showed resolving hepatitis. Passively acquired HCV antibodies are obviously found in newborns of anti‐HCV‐positive mothers with chronic hepatitis. In 1 of 11 children, active anti‐HCV production and concomitant liver disease suggested mother to infant transmission of hepatitis C virus infection.
Junin virus‐induced suppressor cells are effective only on the efferent limb of the delayed‐type hypersensitivity response
Authors: Campetella Oscar E. , Galassi Nora V. , Barrios Hebe A.
Published: March 2007

Junin virus (JV), the etiological agent of Argentinian hemorrhagic fever, induces high mortality in the suckling BALB/c mouse, which correlates with delayed‐type hypersensitivity (DTH)‐like immune response. In contrast, the adult mouse is resistant to infection, and no DTH response can be detected. An antigen‐nonspecific DTH suppressor T‐cell activity induced by JV has been described that may be related to adult mouse survival. In this report, we present evidence supporting the inability of such cells, identified here as bearing the L3T4 marker, to affect the normal establishment of a DTH reaction. In the same form, virus‐induced suppressor cells were unable to alter the expression of DTH effector cells in the absence of antigen‐specific DTH suppressor cells. Besides, we found that a single high dose (200 mg/kg) of cyclophosphamide before or after JV inoculation was unable to alter the activity of virus‐induced suppressor cells.
Natural killer (NK) cell response after vaccination of volunteers with killed influenza vaccine
Authors: Schapiro J. M. , Segev Y. , Rannon L. , Alkan M. , Rager‐Zisman B.
Published: March 2007

Many experiments have shown convincingly that natural killer (NK) cell activity against viral infections is an important early defence mechanism in mice. Since the NK response occurs soon after infection, often long before clinical signs of disease become manifest, it has been difficult to design studies to monitor accurately NK cell kinetics following infection, without actually administering pathogens to volunteers. There is therefore little data pertaining to the role of NK cells in humans. Nevertheless, a number of studies have shown elevated NK activity in response to herpes simplex and influenza virus infections in humans. Our study was designed to show that NK activity could be provoked in humans by exposure to viral particles without actual live viral infection. The development of NK cell response in the peripheral blood of volunteers shortly after vaccination with killed influenza trivalent vaccine was studied. The results demonstrate that killed virus vaccine induces and augments NK cell activity for relatively long periods. Such data may prove valuable for designing possible modes of augmenting NK activity as a therapeutic tool.
Comparison of enzyme immunoassay with radioimmunoassay for the detection of antibody to hepatitis B core antigen as the only marker of hepatitis b infection in a population with a high prevalence of hepatitis B
Authors: Parkinson Alan J. , McMahon Brian J. , Hall David , Ritter Donald , Fitzgerald Mary Anne
Published: March 2007

Enzyme immunoassay (EIA) and radioimmunoassay (RIA) for the detection of antibody to hepatitis B core antigen (anti‐HBc) were compared using serum specimens from Alaska Natives screened during a hepatitis B control program that were initially positive by EIA for only anti‐HBc. Of 36 specimens from persons previously HBsAg positive but who were now only anti‐HBc positive by EIA, 94.4% were anti‐HBc positive by both assays, with anti‐HBc levels exceeding 93% inhibition. Low‐level antibody to hepatitis B surface antigen (anti‐HBs) (<10 SRU) and antibody to hepatitis Be (anti‐HBe) were also present in 50% and 48% of specimens positive for anti‐HBc, respectively. Of 148 specimens from persons initially positive for only anti‐HBc by EIA who had no previous documentation of any hepatitis B virus (HBV) infection, 64.5% were positive by repeat testing for anti‐HBc by both assays, and anti‐HBc levels in this sample exceeded 70% in 91.6% and 80.2% of specimens by EIA and RIA, respectively. Low‐level anti‐HBs and anti‐HBe were present in 45.8% and 15.6%, respectively. EIA detection of anti‐HBc was found to be less specific than RIA. Of specimens positive for anti‐HBc by EIA, 14.8% were negative by RIA. The specificity of the EIA could be improved with respect to RIA by increasing the cut‐off from 48% to 68%. In samples with lowlevel anti‐HBc (≧70% inhibition) as measured by either method, the anti‐HBc results was less likely to persist upon retesting, whereas sample with anti‐HBc levels of >70% inhibition the anti‐HBc was a reproducible finding frequently accompanied by either low‐level anti‐HBs or anti‐HBe.
History, precedent, and progress in the development of mammalian cell culture systems for preparing vaccines: Safety considerations revisited
Authors: Hilleman Maurice R.
Published: March 2007

The use of cell substrates to propagate viruses or recombinant plasmids for vaccine productions has been the subject of long evolutionary conflict, primarily from the standpoint of product safety, and especially from the viewpoint of cancer induction.

The present concern is for safety of vaccines made using transformed or neoplastic mammalian cells that may contain endogenous contaminating viruses or integrated gene sequences from oncogenic viruses. There is also concern for use of plasmid vectors employing promoter elements from oncogenic viruses. The principal concern for safety lies with retention of residual DNA in the vaccine, especially since induction of cancer is a single‐cell phenomenon, and a single functional unit of foreign DNA integrated into the host cell genome might serve to induce cell transformation as a single event or part of a series of multifactorial events.

Current proposed standards for vaccines would permit contamination with up to 100 pg of heterologous DNA per dose. This is equivalent to about 108 “functional lengths” of DNA. Total safety would seem to require complete absence of DNA from the product.

While preparation of biologicals used to treat serious disease might demand the use of mammalian cells, this is not the situation with vaccines that are given prophylactically to persons who might be given equally efficacious vaccines produced in bacterial cells or in yeast that have attributes for greater safety. Careful assessment of safety and risk vs. benefit of continuous mammalian cell‐produced vaccines should be made by technically expert scientists in the relevant disciplines and a consensus needs to be evolved in the scientific community at large.
Hepadnaviruses in cirrhotic liver and hepatocellular carcinoma
Authors: Robinson William S. , Klote Linda , Aoki Naoto
Published: March 2007

Hepadnaviruses share properties of virion structure, genome structure and replication, epidemiologic behavior, and pathogenic effects, including an association with hepatocellular carcinoma (HCC). Epidemiologic evidence implicating hepadnavirus infection in HCC includes the observation that the geographic distributions of HBV infection and HCC are similar, that the incidence of HCC is much higher in hepadnavirus infected than uninfected hosts, and that viral DNA sequences are integrated in the cellular DNA of most (e.g., 80–90%) but not all hepadnavirus‐associated HCC. Cirrhosis further increases the risk of HCC in HBV infected humans. The precise role of hepadnaviruses in development of most HCC is unclear, although the finding of viral integrations within or near protooncogenes in a few cases suggests the possibility that these integrations may play a direct role in these HCC. However, in the great majority of HCC associated with HBV infections, viral integrations are in different cellular DNA sites in different HCC, integrations are not within domains of known protooncogenes, and integrations are not found in some 10–15% hepadnavirus‐associated HCC, suggesting that persisting viral sequences are not directly involved in the development of these HCC as viral sequences are for tumors caused by viruses with oncogenes or viruses that act by a “promoter‐insertion” mechanism. It is possible, however, that oncogenic mutations could arise via other mutagenic mechanisms that may operate in chronic hepatitis B and/or cirrhosis and which do not involve persisting viral integrations. For example, liver regeeration, which is a feature of the cirrhosis associated with chronic HBV infection (and sometimes with chronic hepatitis B) involves proliferation of many cells with HBV integrations, and such integrations have been shown to be unstable and may lead to mutations through post‐integration rearrangements of cellular sequences at sites of viral integrations. Viral sequences appear to be lost or deleted at some such sites of rearranged cell DNA. Chronic HBV infection shares pathologic features of liver cell injury and reactive inflammation, liver regeneration, and in man sometimes cirrhosis with other important risk factors for HCC including chronic alcoholic liver disease, chronic non‐A, non‐B hepatitis, hemochromatosis, and crypogenic cirrhosis, suggesting that this common pathologic process may be carcinogenic by a mechanism that does not depend specifically on the factor which initiates liver cell injury. The pathogenetic role of chronic hepadnavirus infection in such a process would be in causing liver cell injury with reactive infammation and hepatocyte proliferation (regeneration). It is important to investigate mutagenic mechanisms in such liver disease, to search for one or a few common oncogenic mutations in hepadnavirus‐associated HCC, and to determine how these viruses may play a role in the carcinogenic process.
Molecular mechanisms of nucleic acid integration
Authors: Coffin John M.
Published: March 2007

There are three known mechanisms by which foreign DNA can be made a permanent part of the genome of an animal cell, and their properties are summarized in this report. Naked DNA introduced into cells is usually rapidly lost, but a small fraction can be integrated by illegitimate recombination, usually accompanied by major and unpredictable rearrangements in both inserted DNA and target. This mechanism, although inefficient and disruptive, accounts for virtually all integrated DNA seen in virus infections, and is often used for making cell lines carrying specific genes as well as transgenic mice. Homologous recombination between inserted and resident DNA is much rarer but can be detected and put to use. The best understood mechanism is that employed by retroviruses and related elements. In contrast to the other mechanisms, retroviral integration results in a predictable, stable association between virus and cell DNA with only minor sequence changes. However, it occurs only when the DNA is derived by reverse transcription of the RNA in an incoming viral particle and contains the correct sequences at its ends. Thus, from a standpoint of vaccine safety, only the first of the three mechanisms is at all relevant. Based on some prior experimentation in animals, the risk of introduction of activated oncogenes or other dangerous sequences by this means is extremely small.
Risk of tumor induction in vivo by residual cellular DNA: Quantitative considerations
Authors: Löwer Johannes
Published: March 2007

Certain genes, termed oncogenes, have the ability to transmit the transformed phenotype from tumor cells to hitherto normal cells in vitro and in vivo. This observation is the basis for the concern that medicinal products derived from tumor cell lines could contain possibly tumorigenic contaminating cellular DNA. A comparison between the number of oncogenes necessary for the induction of tumors in a suitable animal model and the quantity in 100 pg residual cellular DNA was carried out. It is shown that the latter contains less than a billionth of the number needed to induce tumors in half of the animals tested. Some factors implicit to this calculation such as the validity of the model system, the linearity of the dose response curve, the concept of multistep carcinogenesis, the amplification of oncogenes, and the transfection enhancing effect of other constituents of the drug are discussed. In summary, 100 pg residual cellular DNA per dose seems to be a safe and, therefore, an acceptable upper limit provided that some factors such as excessive amplification of oncogenes, co‐purification of oncogenic DNA with the product or some transfection mediating activity can be excluded.
Genome and antigenic analysis of influenza A (H3N2) viruses isolated from an epidemic in a closed community of Carmelite nuns
Authors: Donatelli I. , Takhonova A. M. , Klimov A. I. , Ghendon Y. Z. , Oxford J. S.
Published: March 2007

Eighteen influenza A (H3N2) viruses were isolated during a single outbreak in a closed community of Carmelite nuns. Serological analysis of the virus haemagglutinin (HAs), using a panel of monoclonal antibodies, demonstrated antigenic microheterogeneity. In contrast, no significant biochemical differences were detected in viral genes by RNA:RNA hybridisation or in structural or nonstructural polypeptides analysed by high‐resolution polyacrylamide gel electrophoresis (PAGE) or by limited proteolysis followed by PAGE. Influenza A (H3N2) viruses isolated in the vicinity of the convent were distinguishable from each other and from the epidemic viruses isolated in the convent both antigenically and biochemically.
Recurrent herpes simplex virus type 1 infection precipitated by the impaired production of interleukin‐2, alpha‐interferon, and cell‐mediated cytotoxicity
Authors: Kuo Yuh‐Chi , Lin Ching‐Yuang
Published: March 2007

In order to understand whether immunosuppression due to the primary host defense defect provokes the reactivation of herpes simplex virus type 1 (HSV‐1), 11 healthy persons were evaluated immunologically after recurrence of herpes. A decrease was found in the production of interleukin‐2 (IL‐2) and alpha‐interferon (IFN‐α) to HSV‐1 antigen stimulation in the recrudescent stage (0 to 3 days after onset of the lesion). The cell‐mediated cytotoxicity also decreased. To clarify the relationship between the immunosuppression and the occurrence of herpes recurrence, a further longitudinal study was undertaken measuring IL‐2, IFN‐α production, and cell mediated cytotoxicity every other week in 12 persons who suffered frequently from recurrent HSV‐1 infection. IL‐2 and IFN‐α production after HSV‐1 antigen stimulation and cell‐mediated cytotoxicity before recurrence of herpes were lower than those without recurrence. These defective immunologic responses were persistent and became more pronounced during the recrudescent phase. The results suggest that the defect in the immunologic responses to HSV‐1 antigen is related to the recurrence of herpes simplex.
Typing of hepatitis B virus genomes by a simplified polymerase chain reaction
Authors: Norder Helene , Hammas Berit , Magnius Lars O.
Published: March 2007

The amplification of hepatitis B virus (HBV) DNA sequences in sera for molecular epidemiology of HBV is an important application of the polymerase chain reaction (PCR) with regard to HBV. To simplify the PCR for this purpose, the optimal concentrations of SDS and detergents for carrying out the proteinase K digestion and the amplification of DNA by Taq polymerase were evaluated. It was found that by using 1% deoxycholic acid as detergent for the proteinase K step and diluting the digest 10 times before carrying out the PCR, the phenol extraction of DNA became superfluous. The sensitivity of this procedure equalled that of PCR after phenol extraction on comparable amounts of serum.

Four pairs of oligonucleotide primers were compared for amplification of HBV DNA sequences in 48 sera previously subtyped with respect to hepatitis B surface antigen (HBsAg), and in eight sera with different genotypes of HBV, representing the subtypes of HBsAg P1 to P8, defined at an international meeting [Couroucé‐Pauty et al.: “HBs Antigen Subtypes.” Basel: Karger, 1976]. Two primer pairs, selected from conserved regions in the X and S genes of HBV, gave a positive PCR with sera harbouring all the eight different strains of HBV, resulting in DNA fragments consistent with the sizes deduced from genome sequence data. Two other primer pairs were selected in order to discriminate genotypes with regard to differences between d/y and w/r strains. With these primer sets total agreement was obtained with previous results from subtyping with regard to d/y and w/r with all 48 sera, but more complex results were obtained with P1 to P8, which partially, however, confirm a recent grouping of HBV genomes based on genetic relatedness [Okamoto et al.: Journal of General Virology 69:2575, 1988].
Relation of maternal CMV viremia and antibody response to the rate of congenital infection and intrauterine growth retardation
Authors: Harrison C. J. , Myers M. G.
Published: March 2007

Pregnancy outcome after maternal primary CMV infection initiated at different times during gestation was investigated by using the inbred Strain‐2 guinea pig model of congenital CMV infection. The highest vertical transmission rates occurred in pups from dams that were initially viremic in late gestation presumably because delivery occurred prior to detectable maternal CMV‐specific immune response. In contrast, conceptus loss was highest with maternal CMV infection initiated at conception. Intrauterine resorptions, intrauterine growth retardation, and disseminated neonatal CMV infection with CNS involvement were more frequent in pups born to mothers that were initially viremic prior to rather than after midgestation. Maternal viremia was prolonged and antibody responses were delayed after CMV inoculation in early gestation compared to late gestation. Prolonged maternal viremia plus early gestational virus exposure/infection of the fetus appeared to be associated with the most severe outcome. These findings suggest that the timing of initial maternal viremia and immune responses, the stage of fetal development, and the length of in utero exposure to CMV are important factors in subsequent disease expression and rates of congenital infection.
5‐bromodeoxyuridine enhancement of Inoue‐Melnick virus synthesis in human colon carcinoma cell lines
Authors: Inoue Y. K. , Nishibe Y. , Kimura T.
Published: March 2007

Inoue‐Melnick virus (IMV) synthesis in naturally infected human colon carcinoma cell lines can be enhanced by 5‐bromodeoxyurdine (BUDR). The optimal conditions for BUDR enhancement differed between two cell lines, SW‐480 and DLD‐1, SW‐480 cells produced 100 times more infectious IMV than DLD‐1 cells by BUDR treatment. A clonal difference in IMV synthesis in SW‐480 cells was also observed. The highest titer of virus was found in the culture fluid of clone H (SW‐480/H) cells treated with BUDR, and a herpes‐like virus was detected by negativestaining electron microscopy of concentrates of the culture fluid. One nonproducer clone (SW‐480/B) was also activated to produce virus when treated with BUDR.
Nucleotide sequence comparison of homologous genomic regions from variola, monkeypox, and vaccinia viruses
Authors: Cowley R. , Greenaway P. J.
Published: March 2007

The nucleotide sequences of homologous regions from the genomes of variola major strain Harvey, variola minor strains Butler and Garcia, and monkeypox strain Denmark were determined. The nucleotide sequences were compared to the homologous region in vaccinia virus which contains part of one of the genes involved in determining host range. Two major differences were detected; these corresponded to a deletion in the promoter region and the presence of a premature stop codon. It was concluded that this region of the genome may not be actively expressed in either variola‐ or monkeypox‐virus‐infected cells. It was also concluded that diagnostic nucleic acid hybridisation probes for differentiating between these members of the Orthopoxviridae may be difficult to identify.
Recombinant proteins VP1 and VP3 of hepatitis A virus prime for neutralizing response
Authors: Gauss‐Müller Verena , Mingquan Zhou , von der Helm Klaus , Deinhardt Friedrich
Published: March 2007

Six overlapping genomic regions of capsid proteins VP1 and VP3 of hepatitis A virus (HAV) inserted into the expression vectors pBD or pUR respectively expressed β‐galactosidase‐HAV fusion proteins. The recombinant proteins were poorly soluble so they were difficult to detect by human anti‐HAV sera in radioimmunoassay, but the fusion proteins dissolved in sodium dodecyl sulfate reacted with human and rabbit anti‐HAV‐positive sera in immunoblots. Antisera against VP1 and VP3 recombinant proteins reacted with the respective structural proteins of HAV in immunoblots. Two recombinant proteins, one including the first 120 amino acids of the N‐terminus of VP1 and the other containing all of VP1 except for the first 60 N‐terminal amino acids, induced a transient neutralizing antibody response in rabbits. Antisera directed against other regions of VP1 and VP3 neither neutralized viral infectivity nor recognized native virus in a competitive radioimmunoassay. However, when immunized animals were challenged with a subimmunogenic dose of HAV, all animals responded with stable virus‐neutralizing antibodies.
Hepatitis B virus clearance from serum and liver after acute hepatitis delta virus superinfection in chronic HBsAg carriers
Authors: Pastore G. , Monno L. , Santantonio T. , Angarano G. , Milella M. , Giannelli A. , Fiore J. R.
Published: March 2007

Clinical, virological, and histological findings in four HBsAg chronic carriers who cleared HBV markers from both serum and liver following HDV superinfection are described. The patients were long‐term HBsAg carriers and all were HBV‐DNA/HBeAg positive. Liver biopsy, obtained from three of the patients between 5 and 15 months prior to HDV superinfection, showed chronic persistent hepatitis in two and chronic active hepatitis in one. During the follow‐up of 9–19 months, the patients completely recovered from acute delta hepatitis with termination of HBsAg carriage and regression of the histological feature of chronic liver damage.

These data demonstrate that sometimes HDV is able to induce a permanent inhibition of its helper virus. HDV superinfection probably enhances the immune clearance of infected cells during the replicative phase of chronic HBV infection.
High genomic variability in the pre‐C region of hepatitis B virus in anti‐HBe, HBV DNA‐positive chronic hepatitis
Authors: Fiordalisi Gianfranco , Cariani Elisabetta , Mantero Giovanni , Zanetti Alessandro , Tanzi Elisabetta , Chiaramonte Maria , Primi Daniele
Published: March 2007

Some chronic HBV carriers have circulating HBV DNA despite the presence of anti‐HBeAg antibodies. This observation has recently been related to the presence, in the HBV pre‐C region, of a translational stop codon that prevents HBeAg synthesis. In the present study, we analyzed, at the nucleotide level, the pre‐C/C region of HBV isolated from the sera of 11 anti‐HBe, HBV DNA‐positive chronic carriers. Nucleotide sequence analysis of 25 independent clones revealed that the pre‐C sequence is highly variable, even among clones derived from the same serum sample. Moreover, our data show that HBeAg synthesis can also be prevented by as yet undescribed T‐C substitution at position 1815 that eliminates the start codon of the pre‐C transcript. These results suggest that the HBV genome contains segments of high variability that have probably been selected during evolution to favor the segregation of functionally advantaged mutants capable of avoiding host immunity.
Cytopathogenicity, drug susceptibility, and thymidine kinase activity of a retinovirulent herpes simplex virus type 2
Authors: Langford M. P. , Colacino J. M. , Kaiwar R. , Mahjoub S. B. , Ganley J. P.
Published: March 2007

We investigated some of the biological and biochemical characteristics of a neurovasive, retinovirulent herpes simplex virus type 2 strain SL (HSV‐2[SL]) and compared them with those of a neurovirulent, nonretinovirulent HSV‐2(186). HSV‐2(SL) was shown to spread rapidly and produce large syncytium in vitro. HSV‐2(SL) and HSV‐2(186) were equally susceptible to acyclovir (ACV) and thymine arabinoside (Ara‐T). However, HSV‐2(SL) was fourfold and 44‐fold more susceptible than HSV‐2(186) to iododeoxyuridine (IUdR) and bromovinyldeoxyuridene (BVDU), respectively. In addition, cytosolic TK from HSV‐2(SL)‐infected cells phosphorylated 4, 20, and 23,000 times more IUdR, iododeoxycytidine (IdCyD), and Ara‐T than the TK of HSV‐2(186), respectively. Further, HSV‐2(186) replication was inhibited by Ara‐T. These studies indicate that the retinovirulent HSV‐2(SL) has a syn phenotype and a TK with broad substrate activity.
Defined epitope blocking with Murray Valley encephalitis virus and monoclonal antibodies: Laboratory and field studies
Authors: Hawkes R. A. , Roehrig J. T. , Boughton C. R. , Naim H. M. , Orwell R. , Anderson‐Stuart P.
Published: March 2007

In an attempt to develop a specific serological test for Murray Valley encephalitis (MVE) virus antibodies, a panel of MVE monoclonal antibodies was utilised in defined‐epitope blocking ELISA tests. In sera of mice immunised singly and in combinations of MVE, Alfuy (ALF), and Kunjin (KUN) viruses, blocking patterns usually distinguished MVE infections from those of the other flaviviruses.

When blocking tests with selected MAbs were applied to 468 flavivirus antibody positive sera collected from human subjects throughout New South Wales, sera with blocking patterns consistent with previous MVE infection were found in 18 subjects. All were long‐term residents of areas previously frequented by MVE, and all were of an age to have been exposed to the virus in past epidemics. No such sera were found in subjects living in coastal areas of NSW where MVE has never been reported.
Human monoclonal antibodies to human cytomegalovirus derived from peripheral blood lymphocytes of healthy adults
Authors: Kitamura Kunio , Yamada Kazumasa , Kuzushima Kiyotaka , Morishima Tsuneo , Morishima Yasuo , Yamamoto Naohiko , Nishiyama Yukihiro , Ohya Kenichi , Yamaguchi Hiroshi
Published: March 2007

Immunoglobulin G class human monoclonal antibodies to human cytomegalovirus (HCMV) were produced by the fusion of Epstein‐Barr virus‐transformed B cells and a murine myeloma cell line. The B cells were derived from the peripheral blood lymphocytes of healthy adult volunteers. Four hybridomas producing HCMV‐specific monoclonal antibodies were established and each of four antibodies immunoprecipitated an HCMV‐specific protein with a molecular weight of 68 kDa. However, the antibodies differed in some of their properties as characterized by indirect immunofluorescence assay and immunoblotting studies, due to the detection of different epitopes on the reacting antigen. None of the four antibodies had any virus neutralizing activity.
Rapid recovery in mice after combined nasal/oral immunization with killed respiratory syncytial virus
Authors: Reuman Peter D. , Keely Scott P. , Schiff Gilbert M.
Published: March 2007

Based on the concept of a common mucosal immune system, the murine gastrointestinal tract was inoculated (oral) with three doses (5, 20, and 40 μg) of UV‐inactivated respiratory syncytial virus (RSV) in order to elicit a virus‐specific immune response in the respiratory tract. Only the 40 μg dose induced significant (P < 0.01) anti‐RSV‐IgG rises in serum and lung wash compared to controls. To improve the immune response, mice were immunized intranasally under light anesthesia with the same 40 μg dosage regimen of killed RSV so that each dose passed through the nose and was swallowed. This combined nasal/oral immunization stimulated anti‐RSV‐IgG in serum, lung wash and nasal wash (P < 0.001) and anti‐RSV‐IgA in lung and nasal wash (P < 0.001) that were comparable to levels after infection with live RSV. Three days after challenge with live RSV, mice given combined nasal/oral immunization showed suppressed nasal virus shedding (P = 0.025). Nasal virus shedding correlated inversely with concentrations of anti‐RSV‐Ig in nasal secretions but did not correlate with concentrations in serum.
Hepatitis C virus in a prospective study of posttransfusion non‐A, non‐B hepatitis in Taiwan
Authors: Wang Jin‐Town , Wang Teh‐Hong , Lin Jaw‐Town , Sheu Jin‐Chuan , Sung Juei‐Low , Chen Ding‐Shinn
Published: March 2007

Using an enzyme‐linked immunosorbant assay for antibody against hepatitis C virus (anti‐HCV), serial serum samples from 26 non‐A, non‐B (NANB) posttransfusion hepatitis (PTH) patients were studied in a prospective study in Taiwan. Sixteen (61.5%) of the 26 patients were positive for anti‐HCV antibodies. Two of the 16 patients were positive for anti‐HCV before transfusion. The remaining 10 patients were negative for anti‐HCV antibodies. The rate of anti‐HCV seroconversion is, therefore, 58.5%. Of the 14 patients with anti‐HCV seroconversion, three were hepatitis B surface antigen (HBsAg) carriers. The time of seroconversion for anti‐HCV ranges from 2 to 24 weeks after the first elevation of ALT (mean: of 8.7 weeks,) or 6–32 weeks from the date of transfusion (mean: 13 weeks). Twelve (85.7%) of the 14 anti‐HCV seroconverted patients had persistent abnormal ALT 6 months after the onset of hepatitis in contrast to 30% of chronicity in the anti‐HCV‐negative patients. The results suggest that HCV is the major causative agent in NANB PTH in Taiwan, and patients positive for anti‐HCV have a higher risk of chronicity.
Protein analysis of newly isolated variants of echovirus type 18 by electrophoresis and Western blotting
Authors: Hayase Yukiharu , Toya Kazuo , Tanaka Toshinori , Tobita Kiyotake
Published: March 2007

The protein patterns of two newly isolated antigenic variants of echovirus type 18 were compared with those of the prototype strain. Electrophoretic mobilities of VP1 and VP2 of the variants differed from those of the prototype strain. The antiserum against the prototype strain reacted to VP0 and VP2 in the Western blotting experiment. In addition, the variants differed from the prototype strain in growth behavior in the cultured cells.
Immune response to guinea pig cytomegalovirus polypeptides and cross reactivity with human cytomegalovirus
Authors: Kacica Marilyn A. , Harrison Christopher J. , Myers Martin G. , Bernstein David I.
Published: March 2007

The immune response to guinea pig cytomegalovirus (gpCMV) was evaluated by immunoblotting. Preinoculation guinea pig plasma did not react with gpCMV antigen, whereas convalescent plasma reacted to at least 18 gpCMV‐specific polypeptides. The initial immune response was primarily directed at polypeptides with MWs of 100, 75, and 56 kDa. Over 80% of plasma collected more than 29 days after viral inoculation reacted to these polypeptides and also to those with MW of 54, 52, and 38 kDa. In this report, we also demonstrate cross reactivity between gpCMV and human CMV (HCMV). Human immunoglobulin (IVIG) reacted to at least 20 HCMV polypeptides and cross reacted with six gpCMV polypeptides. GpCMV convalescent plasma also reacted with HCMV polypeptides.
Major antigenic domain recognized by monoclonal antibodies maps within the carboxy‐terminal moiety of a recombinant human immunodeficiency virus‐1 p24 protein
Authors: Gallina A. , Rossi F. , Mariani M. , Bonelli F. , Achilli G. , Cattaneo E. , Milanesi G.
Published: March 2007

Antigenicity in mice of a recombinant polypeptide including the complete amino acid sequence of mature human immunodeficiency virus type 1 p24 protein was studied by induction of monoclonal antibodies (MAbs). A panel of nine recloned hybridomas secreting MAbs with anti‐p24 reactivity was isolated and further characterized. Competitive inhibition experiments suggested that the MAbs could be grouped into four epitopic classes corresponding to at least two distinct determinants. Analysis of reactivity to recombinant p24 deletion variants indicated that all the recognized epitopes are localized within a carboxy‐terminal domain (amino acids 168–208) which should be largely exposed in recombinant as well as authentic antigen. Lack of response to N‐terminal and central portions of p24 suggests that the antigenicity of those regions in the natural polypeptide is strongly conformation‐dependent.
Prevalence of human T‐cell leukemia virus antibody among heterosexuals living in Amsterdam, the Netherlands
Authors: van Doornum G. J. J. , Hooykaas C. , Huisman J. G. , van der Linden M. M. D. , Coutinho R. A.
Published: March 2007

To determine the heterosexual spread of human T‐cell leukemia virus (HTLV‐I) infections, a cohort of 472 individuals with more than 5 heterosexual partners in the 6 months before entry was studied. They were recuited from visitors to the Clinic for Sexually Transmitted Diseases of the Municipal Health Service. Half of the study group was born in the Netherlands, 13% in Surinam or the Dutch Antilles, and 8% in Turkey or Morocco. Seventy percent were involved in commercial sex.

Three persons were positive for HTLV‐I, with serum antibodies against p19, p24, p28, gp46, and gp61 in Western immunoblot (WIB) and radio‐immunoprecipitation assay (RIPA). Two of them originated from Surinam and the third was a Dutch woman. Two other individuals were HIV‐positive, 19% had hepatitis B virus (HBV)‐markers and 6% Treponema pallidum reacted in the hemagglutination assay (TPHA). It is concluded that HTLV‐I ciruclates in the Surinamese population in Amsterdam and there was no evidence of appreciable heterosexual transmission.
Enterovirus‐specific serum IgA antibody responses in patients with acute infections, chronic cardiac disease, and recently diagnosed insulin‐dependent diabetes mellitus
Authors: Muir Peter , Singh N. Brajachand , Banatvala Jangu E.
Published: March 2007

Employing an antibody class capture ELISA, we assessed the significance of enterovirus (EV)‐specific serum IgA (EV‐IgA) as a marker of EV infection. EV‐IgA was detectable in 64% of sera from patients with acute illnesses which may be attributable to EV infection who also had EV‐IgM, but also in 30% of sera from patients without evidence of EV infection. High EV‐IgA levels were more closely associated with the presence of EV‐IgM and were demonstrable in 39% of patients with acute infections who were EV‐IgM positive, compared to 3% of those who were EV‐IgM negative. Among patients with acute EV infection confirmed by virus isolation, EV‐IgA was present in 67% and EV‐IgM was present in 83%. As a marker of acute EV infection, EV‐IgA is less sensitive and less specific than EV‐IgM. EV‐IgA responses in patients with chronic cardiac disease paralleled EV‐IgM responses in some cases but there was no significant association between these two antibody responses in this group as a whole. High EV‐IgA responses were present in 20% of EV‐IgM positive and 21% of EV‐IgM negative patients, and may persist as a result of an immunoregulatory defect leading to virus or antigen persistence at mucosal surfaces. High EV‐IgA levels were also detectable in 33% of EV‐IgM positive newly diagnosed insulin‐dependent diabetics but in none who were EV‐IgM negative, which suggests that most EV infections in these patient were acute rather than persistent.
HIV‐1 variability and progression to AIDS: A longitudinal study
Authors: Fiore Josè Ramòn , Calabró Maria Luisa , Angarano Gioacchino , De Rossi Anita , Fico Cecilia , Pastore Giuseppe , Bianchi Luigi Chieco
Published: March 2007

HIV‐1 replicative activity and its relation to the clinical and immunological evolution of infection was studied in a group of 150 HIV‐1 seropositive Italian i.v. drug abusers over a 1 year period. HIV‐1 was isolated from 91 (60%) subjects; two groups of isolates were distinguished, according to replicative activity “in vitro” and ability to induce cytopathic effects in cell cultures, and were termed “rapid‐high” and “slow‐low” viruses, in agreement with other workers. Rapid‐high viruses were recovered more frequently from patients with ARC/AIDS, while slow‐low viruses seemed related to the asymptomatic period of infection. The replicative properties of HIV‐1 seem to affect strongly the course of disease. In fact, an important CD4 cell decline occurred in asymptomatic subjects with rapid‐high virus infection; asymptomatic subjects with negative viral cultures or with slow‐low viruses showed no such decline. Asymptomatic subjects with negative viral cultures had no signs of disease during the observation period, while 9% with slow‐low virus and 45% with rapid‐high virus progressed to AIDS.
Serum hepatitis B virus DNA in healthy HBsAg‐negative Chinese adults evaluated by polymerase chain reaction
Authors: Shih Ling‐Na , Sheu Jin‐Chuan , Wang Jin‐Town , Huang Guan‐Tarn , Yang Pei‐Ming , Lee Hsuan‐Shu , Sung Juei‐Low , Wang Teh‐Hong , Chen Ding‐Shinn
Published: March 2007

Serum hepatitis B virus (HBV) DNA was assayed using polymerase chain reaction, in 107 HBsAg‐negative normal Chinese subjects. The results showed that eight subjects (7.5%) had HBV DNA. In the subgroup with antibody to hepatitis B surface antigen (anti‐HBs) and to hepatitis B core antigen (anti‐HBc), 7.3% (5/68) were positive for HBV DNA; HBV DNA was not detected in six individuals with anti‐HBs only and in nine with anti‐HBc only. In four persons with anti‐HBc and anti‐HBe, one had HBV DNA. In 20 subjects negative for all hepatitis B serological markers, two (10%) were found to have HBV DNA. This study indicates that serological markers are not adequate to rule out HBV infection, and it further implies that present blood donor screening methods may need improving.
Identification of hantavirus serotypes by testing of post‐infection sera in immunofluorescence and enzyme‐linked immunosorbent assays
Authors: Groen J. , Jordans H. G. M. , Clement J. P. G. , Rooijakkers E. J. M. , UytdeHaag F. G. C. M. , Dalrymple J. , Van Der Groen G. , Osterhaus A. D. M. E.
Published: March 2007

Serum samples were collected from 27 individuals who had been infected with a member of the genus Hantavirus in the Netherlands or Belgium during the last 15 years. These samples were tested in an immunofluorescence assay (IFA) and two enzyme‐linked immunosorbent assay (ELISA) systems, using different virus strains that represented each of the four recently proposed serotypes of this genus. The serum samples from 11 individuals who had been infected through contacts with laboratory rats showed the highest reactivities with Hantaan virus (serotype I) and SR‐11 (serotype 11) in the IFA and ELISA systems. The samples of 16 individuals who had probably been infected through contacts with wild rodents showed the highest reactivities with Hällnäs virus (serotype III) in the IFA. All except two of these also showed the highest reactivity with Hällnäs virus in the two different ELISA systems.
Correlation between HBV DNA detection by polymerase chain reaction and pre‐S1 antigenemia in symptomatic and asymptomatic hepatitis B virus infections
Authors: Chemin I. , Baginski I. , Petit M. A. , Zoulim F. , Pichoud C. , Capel F. , Hantz O. , Trepo C.
Published: March 2007

The presence of hepatitis B virus (HBV) genome in sera from 73 symptomatic and asymptomatic HBsAg carriers was studied by the polymerase chain reaction (PCR) with primers specific for the S and C regions. Pre‐S proteins of the HBV envelope were detected in serum by a specific monoclonal antibody in a double immunoradiometric assay.

Out of twenty‐five symptomatic patients with chronic active hepatitis (14 with HBeAg and 11 with anti‐HBe), all were positive for HBV DNA by PCR, while 14/14 HBeAg and 2/11 (18%) of the anti‐HBe patients were positive by dot blot hybridization. All but one anti‐HBe patient (96%) carried Pre‐S1 proteins. Among the asymptomatic HBsAg carriers, HBV DNA was detected by PCR in 14/14 (100%) HBeAg positive patients and in 25/34 (73%) anti‐HBe positive patients. Pre‐S1 proteins were found, respectively, in 14/14 (100%) and 11/22 (50%) of the same cases tested in parallel. The 20 healthy blood donors devoid of HBV markers and with normal transaminases tested were found negative for HBV DNA using PCR.

Out of 12 patients who recovered from acute hepatitis 6, all were found negative by PCR analysis after a mean follow up of 1 year after seroconversion to anti‐HBs. When serial samples from 2 patients (one with acute hepatitis 6, the other with chronic hepatitis 6) were tested for the presence of HBV DNA and of Pre‐S1 proteins, both markers showed parallel development.

The results indicate that HBV DNA detected by PCR is associated significantly with the presence of Pre‐S1 proteins (P < 0.0001) and does reflect the presence of complete virions in sera from patients negative for HBV DNA by the conventional hybridization technique. The results also suggest a slower clearance of infectious particles than assumed previously.
Acute sporadic hepatitis in Sudanese children
Authors: Hyams K. C. , Hussain M. A. M. , Al‐Arabi M. A. , Atallah N. Al‐Huda , El‐Tigani A. , McCarthy M. C.
Published: March 2007

Eighty consecutive cases of acute viral hepatitis and 80 controls selected from a public pediatric clinic were entered into a study of acute sporadic hepatitis in Khartoum, Sudan. Study subjects were 14 years of age or younger and were mainly from a low socioeconomic level. Non‐A, non‐B hepatitis was diagnosed by exclusion in 35 (43.8%) patients, hepatitis A in 27 (33.8%), acute hepatitis B in 8 (10.0%), possible Epstein‐Barr virus (EBV) hepatitis in 1 patient; and dual hepatitis A and B infection in 1 patient. Eight acute cases were positive for HBsAg but negative for anti‐HBc IgM and anti‐HAV IgM. Delta hepatitis was not identified in any study subject. A household case of jaundice and acquaintance with an individual outside of the household with jaundice during the prior 6 months were associated with non‐A, non‐B hepatitis. There was no association between parenteral exposure and non‐A, non‐B hepatitis. These findings suggest that enterically transmitted non‐A, non‐B hepatitis may be a major cause of acute sporadic hepatitis in children in this area, as well as a cause of epidemic hepatitis.