bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative assessment of antiretrovirals in human monocyte‐macrophages and lymphoid cell lines acutely and chronically infected with the human immunodeficiency virus
Authors: Crowe Suzanne M. , McGrath Michael S. , Elbeik Tarek , Kirihara Jean , Mills John 
Published: March 2007

AbstractWe compared the efficacy of 3 antiretrovirals in cultured human peripheral blood monocyte‐derived macrophages and lymphoid cells infected with the human immunodeficiency virus (HIV). Zidovudine (>0.01 μg/ml) orfoscarnet (100 μg/ml) consistently inhibited HIV replication (p24 antigen production) in acutely infected macrophages by more than 90%; alpha interferon, (1,000 units/ml) inhibited HIV replication by 88–99%. Drug efficacy was equal in lymphoid cells and monocyte‐derived macrophages. However, these antiretrovirals even in high concentration only minimally inhibited chronic, established HIV infection: while zidovudine (0.01 μg/ml) inhibited infection by over 90% in acutely infected macrophages and lymphoid cells, 50 μg/ml of this antiretroviral produced only 19–55% inhibition of HIV in chronically infected cells. Slot‐blot analysis of HIV RNA was concordant with the p24 antigen data. Acutely infected macrophages are as susceptible to the inhibitory effects of antiretrovirals as lymphoid cells; however, chronically infected macrophages (which probably constitute the main in vivo reservoir for HIV) are several orders of magnitude more resistant.
Mutants of the hepatitis b virus surface antigen that define some antigenically essential residues in the immunodominant a region
Authors: Ashton‐Rickardt Philip G. , Murray Kenneth 
Published: March 2007

AbstractThe nature of the immunodominant a region of hepatitis B virus surface antigen (HBsAg) has been examined by mutation of specific amino acid residues. Proline 142 was required for the exhibition of full antigenicity. Replacement of cysteines 124 and 147 by serines drastically reduced or eliminated reactivity with antibodies to HBsAg, which implicates these two residues in stabilising the conformation of the antigen. The a region of HBsAg has also been shown to influence both the immunoreactivity of the adjacent subtype antigenic region, despite being immunologically distinct from it, and the ability of the antigen to interact with a subtype‐specific monoclonal antibody. These results emphasise the importance of the polypeptide region between cysteine residues 124 and 147 in determining a antigenicity, as well as manifestation of the subtype of HBsAg, and reinforce the view that these are conformational epitopes.
Formalin inactivated junin virus: Immunogenicity and protection assays
Authors: Videla Cristina , Carballal Guadalupe , Remorini Patricia , Torre José La 
Published: March 2007

AbstractThe aim of this study was to determine if Junin virus inactivated with formalin (FA) was immunogenic and able to elicit a protective response in the guinea pig. The XJ‐Clone 3 strain of Junin virus grown in Vero cells was exposed to FA at 0°C. The following inactivated antigens were prepared: A1, 0.1% FA for 50 hr; A2, 0.1% FA for 50 hr followed by concentration with polyethylene glycol (PEG); B1, 0.05% FA for 70 hr; B2, 0.05% FA for 70 hr plus PEG concentration; C, 0.1% FA for 50 hr followed by ultracentrifugation and purification by sucrose gradient. No residual infectivity was detected in any inactivated antigen either after two passages in newborn mice or by coculture with Vero cells.After immunization, high‐neutralizing and low‐immunofluorescent antibody titers were obtained in adult mice and guinea pigs, thus showing that antigenicity was preserved. However, in spite of the presence of neutralizing antibodies, guinea pigs gained no protection against challenge with the highly pathogenic XJ strain.These results suggest that antibody amount and/or quality may be inadequate; alternatively, mechanisms other than humoral immunity, such as cellular response, not elicited by inactivated antigens may be essential for protection against Junin virus.
Efficiency of the polymerase chain reaction for the detection of human immunodeficiency virus type (HIV‐1) DNA in the lymphocytes of infected persons: Comparison to antigen‐enzyme‐linked immunosorbent assay and virus isolation
Authors: Stoeckl Elisabeth , Barrett Noel , Heinz Franz X. , Banekovich Michael , Stingl Georg , Guggenberger Klaus , Dorner Friedrich , Kunz Christian 
Published: March 2007

AbstractSeventy‐one human immunodeficiency virus type (HIV‐1)‐positive patients were investigated by polymerase chain reaction (PCR), virus isolation, and antigen detection for the existence of HIV in blood. The identification of HIV DNA by PCR, using three different pairs of primers, yielded a clearly higher detection rate (86%) than with two primer pairs (75%) and was far more sensitive than virus isolation (45%) and antigen ELISA (14%). The PCR‐negative results were clearly correlated to asymptomatic clinical stages. However, there was a limited correlation between the clinical stage of disease and the amount of HIV DNA that could be detected in equal numbers of CD4+ cells from different patients, which might be due to their treatment with azido‐thymidine (AZT).
Pig erythrocyte ghost cells used for concentration of enteric viruses from experimentally contaminated clinical specimens
Authors: Armon R. , Neeman I. , Kott Y. 
Published: March 2007

AbstractA simple, rapid and efficient procedure of virus concentration from urine, cerebrospinal fluid (CSF), and feces was developed. Pig erythrocyte ghost cells were used to adsorb and elute such viruses as poliovirus LSC‐1, echovirus 6, and human rotavirus (clinical isolate). In urine and CSF, the adsorption efficiency range was 80–100% and elution was from 85% to >100%. In addition, poliovirus LSC‐1 was used as an experimental model to examine this procedure under various clinical conditions, such as calcium, glucose, amino acids, and urea at high concentrations. These were added to normal urine specimens to simulate pathological conditions. The results suggest that pig erythrocyte ghost cells are an efficient matrix for adsorption and elution of enteric viruses found in clinical specimens of urine, CSF, and feces. This method might be useful in virus concentration from clinical specimens and for preparative microscopy and other clinical laboratory methods that require subsequent virus concentration.
Preliminary evidence that azidothymidine does not affect hepatitis B virus replication in acquired immunodeficiency syndrome (AIDS) patients
Authors: Farraye Francis A. , Mamish Diaa M. , Zeldis Jerome B. 
Published: March 2007

AbstractThe effect of azidothymidine (AZT) on hepatitis B virus (HBV) replication was determined in three patients with the acquired immunodeficiency syndrome (AIDS). Serum viral DNA was present, and its concentration either remained the same or increased in two patients. Since AIDS patients may be infected with a variety of viral agents in addition to the human immunodeficiency virus (HIV), the effects of the antiviral agents and biological modifiers on other common viral infections should also be determined in developing new approaches to HIV infection. Our results give preliminary evidence that AZT does not affect HBV viral replication in vivo.
Improved Sensitivity of Detection by Avidin—Biotin Complex (ABC) Immunocytochemistry in Epstein‐Barr Virus Serology
Authors: Se Thoe S. Y. , Sam C. K. , Cheng H. M. , Prasad U. 
Published: March 2007

AbstractSerum antibodies against Epstein‐Barr virus (EBV)‐determined antigens have traditionally been titrated by the indirect immunofluorescence (IIF) technique. The avidin—biotin complex (ABC) immunocytochemical technique was used to determine the serum levels of IgA against EBV viral capsid antigen (IgA/VCA) and IgA against EBV early antigen (IgA/EA) in sera of 106 nasopharyngeal carcinoma (NPC) patients prior to treatment and 100 normal individuals. The sensitivity of the ABC technique is enhanced by an amplification of the antigen—antibody reaction, which involves the binding of the enzyme‐linked ABC to the second biotinylated antibody. There was a good correlation (r = 0.9988) between ABC and IIF‐determined IgA/VCA‐positive titres, with the ABC technique being more sensitive than IIF in the detection of IgA/VCA in NPC sera: 94% (99/106) and 76% (80/106), respectively. The frequency of IgA/EA reactivity in NPC sera was also markedly increased by immunodetection with the ABC technique as compared with IIF technique: 63% (69/106) and 28% (30/106) respectively. Both the immunocytochemical techniques were equally specific in discriminating between elevated serum titres of IgA/VCA and IgA/EA in NPC sera from normal human sera.
Herpes simplex virus infections in male and female mice following pinna inoculation: Responses to primary infection and artificially induced recurrent disease
Authors: Blondeau Joseph M. , Embil Juan A. , Sandra McFarlane E. 
Published: March 2007

AbstractThe pathogenesis of herpes simplex virus (HSV) infection is now well understood. After humans or experimental animals recover from primary infection, the virus remains latent in sensory ganglia of the peripheral nervous system. Latency, for the most part, remains unresolved, and elucidating the mechanisms involved with latency has proved difficult. The requirement for unravelling HSV latency is the availability of a reproducible animal model. Previously, the mouse ear model has been extensively characterized; however, many studies using this model have involved female mice only despite evidence that recurrent HSV infection in humans may vary by gender. We inoculated male and female mice subcutaneously in the pinna with varying amounts of one of four strains of HSV and monitored the mice for signs of primary infection. Following recovery from primary infection, mice were induced to develop recurrent disease. In addition, we attempted to isolate virus from dorsal root ganglia of mice suspected of harboring latent virus. There were no differences in the response of male and female mice to either primary infection or artificially induced recurrent disease when inoculated with the same virus. Differences were noted when female mice were inoculated with different strains of virus.
In vivo administration of monoclonal antibody to the NK 1.1 antigen of natural killer cells: Effect on acute murine cytomegalovirus infection
Authors: Shanley John D. 
Published: March 2007

AbstractMonoclonal antibody to the NK 1.1 antigen, found on the natural killer cells of a number of strains of mice, specifically suppresses NK cell function when given in vivo. Using this monoclonal antibody, we have examined the effects of specific suppression of natural killer (NK) cells in vivo on acute murine cytomegalovirus (MCMV) infection in C57BL/10ScN mice. Administration of antibody to NK 1.1 substantially lowered the resistance of C57BL/10ScN mice to lethal virus challenge. In addition, antibody administration prior to intraperitoneal infection significantly increased MCMV replication in salivary glands, lungs, and spleens. In C3H/HeN mice, a strain that lacks the NK 1.1 antigen, antibody to NK 1.1 had no effect on virus replication or lethal infection. Thus, in vivo administration of monoclonal antibody to NK 1.1 alters the course of acute MCMV infection. These findings further substantiate the role of NK cells in defense against acute MCMV infection.
Nested polymerase chain reaction assay for the detection of cytomegalovirus overcomes false positives caused by contamination with fragmented DNA
Authors: Porter‐Jordan Kathleen , Rosenberg Eric I. , Keiser John F. , Gross Jeffrey D. , Ross Allan M. , Nasim Suhail , Garrett Carleton T. 
Published: March 2007

AbstractThe polymerase chain reaction (PCR) technique offers a promising alternative to tissue culture for the rapid and sensitive detection of cytomegalovirus (CMV) infection. However, high levels of background amplification detected in samples containing water but no DNA make interpretation of borderline positive samples extremely difficult and reduce the sensitivity of the assay. The signal from amplification of water or positive samples can be eliminated by DNase treatment, but not by filtration through anisotropic membrane, autoclaving, or ultraviolet irradiation. A lag time of 10 to 12 cycles is observed before the reactions with water will show product formation by liquid hybridization detection. The use of nested PCR eliminates the background and, in serial dilutions of a positive sample, shows a 500‐ to 1000‐fold increase in sensitivity by liquid hybridization detection. We suggest that the background signal is arising from small fragments of DNA, which may be produced by autoclaving viral culture material. Such fragments would escape filtration, and overlapping fragments of DNA can prime one another to form complete mosaic sequences that will then amplify. Nested PCR, appropriately controlled for the number of cycles at each step, should successfully overcome such false positives caused by fragmented DNA, no matter if the contamination occurs at the collection site, in processing, or at the facility performing the test.
Detection of human cytomegalovirus early and late antigen and DNA production in cell culture and the effects of dimethyl sulfoxide, dexamethasone, and DNA inhibitors on early antigen induction
Authors: Li S. B. , Fong C. K. Y. 
Published: March 2007

AbstractRecently a conventional method for the laboratory diagnosis of human cytomegalovirus (HCMV) infection was improved by using centrifugation culture to enhance viral adsorption and by detecting HCMV early antigen and DNA. Comparison of the sensitivity of three rapid methods using commercial diagnostic reagents for the detection of HCMV early antigen (EA), late antigen (LA), and DNA was quantitatively evaluated in centrifugation cultures of human fibroblast cells (MRC‐5) infected with HCMV. HCMV‐EA was first detected 4 hours after infection, and the number of antigen‐positive cells increased rapidly thereafter. Using biotinylated DNA probe, viral DNA was first detected 12 hours postinfection; the number of DNA‐positive cells increased slowly. HCMV‐LA was first seen 48 hours postinfection, and the number of LA‐positive cells also increased thereafter. Thus detection of HCMV‐EA was the most rapid and sensitive method for HCMV diagnosis.Several chemical compounds have been used to enhance HCMV replication. The effect of dimethyl sulfoxide (DMSO), dexamethasone (DEX), 5‐bromo‐2‐deoxyuridine (BrdU), 5‐fluoro‐deoxyuridine (FdU), and cytosine arabinoside (Ara‐C) on HCMV‐EA induction was evaluated in centrifugation cultures of MRC‐5 cells infected with HCMV. Infected cells treated with 1% DMSO alone or with DMSO plus DEX (10−5 M) have been shown to increase the number of HCMV‐EA—positive cells three‐ to fivefold over the untreated control cultures. The enhancing effects of Ara‐C, BrdU, and BrdU plus FdU were demonstrated only occasionally.
Human papillomavirus types in anogenital warts of children
Authors: Gibson Patricia E. , Gardner Sylvia D. , Best Susan J. 
Published: March 2007

AbstractTissue from anogenital warts of 25 children, 10 of whom were suspected of being victims of sexual abuse, was investigated by dot blot and Southern blot techniques for human papillomavirus (HPV) types. HPV DNA was detected in 22 children, two of whom had double infections. The genital HPV types 6 and/or 11 were detected in 20 children, and in three children other HPV types were found. One had HPV 18 (as well as 11); in a second child a possible skin type, HPV 2, was detected; and the third child was infected with an unidentified type.In three cases genital wart material was available from one of the parents, and in all three the HPV type was the same as that of the child. For nine other children one or both parents were reported to have genital warts. The source of infection appeared to be the adult genital tract, but sexual contact might not be the only means of transmission.
Detection of hepatitis B viral DNA by polymerase chain reaction in patients with hepatitis B surface antigen
Authors: Shih Ling‐Na , Sheu Jin‐Chuan , Wang Jin‐Town , Huang Guan‐Tarn , Chen Juei‐Suei , Sung Juei‐Low , Wang Teh‐Hong , Chen Ding‐Shinn 
Published: March 2007

AbstractHepatitis B virus (HBV) DNA was assayed using the polymerase chain reaction in serum samples of 116 hepatitis B surface antigen (HBsAg) carriers, including 30 positive for hepatitis B e antigen (HBeAg) and 86 negative for HBeAg. In the HBeAg‐positive group, all were positive for HBV DNA. In the HBeAg‐negative group, 80.2% were positive for HBV DNA (80.0% in the healthy carrier group, 90.0% in the chronic active liver disease group, and 69.2% in patients with cirrhosis). This study indicated that every HBeAg‐positive carrier as well as the majority of HBeAg‐negative carriers were infectious and, in the latter group, that viral replication is most active in patients with chronic active liver disease.
Diagnostic significance of IgM antibody to hepatitis delta virus in fulminant hepatitis B
Authors: Tassopoulos Nicolaos C. , Koutelou Maria G. , Macagno Silvina , Zorbas Panayiotis , Rizzetto Mario 
Published: March 2007

AbstractThe prevalence of hepatitis delta virus (HDV) infection was studied in 25 adult patients with fulminant hepatitis who were admitted consecutively to our unit from February, 1986, to September, 1988. Enzyme and radioimmunoassays were used for the detection of serological markers of HAV, HBV, and HDV (HDAg, IgM anti‐HD, total [IgG] anti‐HD) infections. Two hundred twenty‐nine serum samples (three to 19 samples/patient) were tested for serological markers of HDV infection. Of the 25 patients, 17 (68%) were HBsAg‐positive, and the remaining eight (32%) were HBsAg‐negative on admission to the hospital. All patients were seropositive for IgM anti‐HBc. Serological markers of HDV infection were detected in 13 (52%) of the 25 patients. In particular, HDV infection was observed in nine (53%) of the 17 HBsAg‐positive and in four (50%) of the eight HBsAg‐negative patients with type B fulminant hepatitis. Survival was 16.7% for patients with hepatitis B and 57.8% for patients with B and D coinfection. Coinfections were responsible for fulminant hepatitis in 100% of drug addicts and 40% in patients who were not drug addicts. All patients with HBV/HDV coinfections became seropositive for IgM anti‐HD. The results show that HDV infection has a significant role (52%) in type B fulminant hepatitis in an area with a moderate prevalence of HBV infections, that it should be tested in cases with early clearance of HBsAg, and that it does not seem to be accompanied by a high fatality rate. Testing for IgM anti‐HD is mandatory for accurate evaluation of the incidence of HBV/HDV coinfections in patients with fulminant hepatitis.
Blocking‐ELISA for detection of specific antibodies to the glycoproteins of the human immunodeficiency virus type 1 (HIV‐1)
Authors: Tardy J. C. , Basson J. , Douglas A. , Aymard M. 
Published: March 2007

AbstractA blocking ELISA was developed to confirm the specificity of screening tests for anti‐HIV‐1 antibodies. A murine monoclonal antibody (McAb) raised against recombinant gp 160 was used in combination with a commercial technique (ELAVIA‐1). After determining the optimal experimental conditions, the assay was applied to 92 samples presenting different reactivities by Western blot (WB) analysis. All the sera containing antibodies to gp160/gp120 (53) were positive in our assay. The six patients who sero converted showed a low positivity by ELAVIA‐1 (optical density near the cutoff value) reacted by blocking‐ELAVIA‐1 with an McAb binding inhibition greater than 85%. By contrast, negative samples (29) and specimens that exhibited reactivity only against gag‐proteins (10) were not detected (McAb binding inhibition smaller than 15%).This sensitive and specific blocking‐ELAVIA‐1 represents a convenient alternative to WB as a confirmatory test. The technique is time‐saving and inexpensive and can easily be integrated with a screening test for diagnostic or epidemiologic studies on HIV‐1 infection.
Inhibition of rate of tumour growth in rodent species by inoculation of herpesviruses and encephalomyocarditis virus
Authors: Cowan M. , Davies J. , Brookes K. , Billstrom M. , McLeish P. , Buchan A. , Skinner G. R. B. 
Published: March 2007

AbstractInoculation of herpesviruses and encephalomyocarditis virus into subcutaneous tumours in hamsters and mice reduced the rate of tumour growth compared to untreated tumours or secondary tumours which had arisen following surgical excision of the primary tumour; in addition, survival times were increased in animals whose tumours were inoculated with virus. It is suggested that the role of virus in the modification of tumour growth merits further exploration.
Detection of measles virus genomic sequences in sspe brain tissue by the polymerase chain reaction
Authors: Godec Mark S. , Asher David M. , Swoveland Peggy T. , Eldadah Zayd A. , Feinstone Stephen M. , Goldfarb Lev G. , Gibbs C. J. , Carleton Gajdusek D. 
Published: March 2007

AbstractThe polymerase chain reaction (PCR) was modified to detect RNA genomic sequences by generating cDNA copies of those sequences as a preliminary step. Oligonucleotide primer pairs complementary to sequences in each of the five major structural protein genes of the measles virus (nucleocapsid protein, phosphoprotein, matrix protein, fusion protein, and hemagglutinin protein) were synthesized. PCR products were tentatively identified by visualization of bands of the appropriate size by ethidium bromide staining after gel electrophoresis, and identity was confirmed by subsequent restriction enzyme cleavage of the products at predetermined sites to yield fragments of predicted size. This method successfully amplified 400–500 base regions from each of these five genes in RNA extracts of wild measles virus cultured in Vero cells and in RNA extracted from most of the SSPE brain tissues tested, but not in RNA from any control brain tissues. Measles virus genome was detected in SSPE brain tissues stored frozen for as long as 27 years and formalin‐fixed paraffin‐embedded subacute sclerosing panencephalitis (SSPE) brain tissues as old as 9 years. This method provides a simple, rapid and highly sensitive means of detecting and identifying sequences of RNA genomes by PCR. The success of this method in detecting measles virus in SSPE brain tissues suggest that PCR is appropriate to investigate the possible presence of RNA viruses in other neurological disorders of unknown etiology.
Case report: Electron microscopic detection of human parvovirus (B19) in a patient with HIV infection
Authors: Chrystie Ian L. , Almeida June D. , Welch Jan 
Published: March 2007

AbstractWe report the findings on an HIV‐positive patient found to be infected with human parvovirus B19. In a comparative study of sequential sera, direct electron microscopy (EM) had the same sensitivity as DNA hydridisation for the detection of the virus. EM did not require specific reagents and also yielded information on the state of the virus; i.e., whether random or complexed, and the type of antibody involved. The presence of parvovirus complicated the judgement as to drug treatment. This case also highlighted the importance of diagnosing the presence of opportunistic viral infections that have no, or lowgrade, pathogenic activity.