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At least 163 records · Page 9Linked to original sources

Herpes simplex virus detection in oral mucosa lesions in patients undergoing oncologic therapy.

UNLABELLED: The presence of Herpes Simplex Virus (HSV) has been a frequent detection in gingivitis and ulcerations of oral mucosa in patients undergoing oncologic therapy. In these patients, lesions tend to show atypical clinical patterns, leading to misdiagnosis. OBJECTIVES: To detect HSV, using an ELISA test, in oral lesions of patients under oncologic therapy, to determine localization of these lesions in the oral cavity, to relate their presence with the general diagnosis of the patient and to compare the test results with the previous clinical diagnosis of the lesions. STUDY DESIGN: Thirty lesions where examined in nineteen pediatric patients under oncologic therapy. Direct samples of all lesions were taken and an ELISA test for HSV type I and II was applied to them. General diagnosis of the patients was consigned, as well as localization of the lesions in the oral cavity and clinical diagnosis of them. A database was elaborated with all the information. RESULTS: 33% of lesions were positive to the test, most of them in patients with acute myeloid leukemia. Localization of lesions was not restricted to areas of mucosa attached to periosteum, but also in areas like the dorsum of the tongue. Positive predictivity of clinical diagnosis was 56,25% and negative predictive index was 92,86%. Sensitivity of the test was 90% and specificity was 65%. CONCLUSIONS: It is very important to corroborate clinical diagnosis of gingivitis and ulcerative lesions of the oral cavity of patients under oncologic therapy with laboratory tests, because of the atypical clinical presentation that can lead to misdiagnosis.

Child↗

[A method of preparing antibody erythrocytic diagnostic means for detecting viruses].

It was found possible to use method for preparation of antibody erythrocytic diagnosticums for detection of agents of influenza and arboviral infections. Test systems prepared by the developed method were superior in sensitivity to immunoreagents prepared with previously proposed amidol. Testing of 1387 tick samples collected in various climatic geographical zones of the Republic of Kazakhstan detected arboviral antigens in 4.61% of cases. The highest share of positive results was observed with diagnostic agents for detection of Syrdarya valley fever and Sindbis viruses (37:5 and 32.81%, respectively).

Animals↗

Gene I products of cauliflower mosaic virus detected in extracts of infected tissue.

The product of cauliflower mosaic virus (CaMV) gene I has been characterized from extracts of infected plants. Two size classes of this protein can be identified by the use of specific antiserum. The antiserum was induced against a chimeric protein produced in E. coli from a gene fusion between a fragment of the CaMV genome and the beta-galactosidase gene. A 36-kDa form of the gene I product is associated with virus particles. A 45-kDa form of this product was found only in the insoluble fraction of tissue homogenates. This insoluble fraction, the only fraction found to contain the product of viral gene VI, contains the virally induced inclusion bodies.

Genes, Viral↗

Genetic and antigenic analyses of bovine respiratory syncytial virus detected in Japan.

Genetic and antigenic analyses of bovine respiratory syncytial virus were conducted on 12 field strains from Tohoku and Hokuriku districts in Japan during from 2002 to 2004. On the phylogenetic tree of the nucleotide sequences of the glycoprotein region, the examined strains fell in the same cluster as the strain isolated in Nebraska and were classified as the subgroup III. The examined strains were subdivided into 2 lineages (A, B). Isoleucine 200 of the epitope domain was replaced by threonine as a feature of the lineage B strains. The examined strains showed the nucleotide sequence homologies of 88.3-93.3% with the known Japanese strains classified as the subgroup II and of 86.1-96.6% with those in the subgroup III. No significant difference was found on the neutralization index between the examined strain and the 52-163-13 phylogenetically similar to the Japanese vaccine one. The results suggest that the subgroup III strains have existed in Japan and that epidemics of the strains could be protected due to the present vaccination.

Amino Acid Sequence↗

[New antigenic variants of influenza A(H1N1) virus detected in the USSR in 1979].

Studies of influenza A (H1N1) viruses isolated in the spring of 1979 in the USSR showed all the 73 strains to belong to influenza A (H1N1) virus but to be heterogeneous. Apart from the strains identical with the reference A/USSR/90/77 and A/Brazil/11/78 as well as intermediate ones, 14 strains were identified and found to be new drift variants. A composite analysis of representative strains of this group (A/USSR/50/79 and A/USSR/61/79) by HI test with diagnostic rat and ferret sera as well as monoclonal antibody and by immunoadsorption method confirmed their individual natures and showed them not to be identical completely to any one of the previously known drift variants of the A (H1N1) subtype. The neuraminidase of the new strains also acquired some changes in the antigenic composition and resistance to detergents destroying disulfide bonds indicating certain alterations in this subunit as well. Besides, a comparison of the drift variants of influenza A (H1N1) virus variants isolated in 1947-1957 and in 1977-1979 showed the drift of the new A (H1N1) strain to occur in a different way than in those isolated in 1947-1957.

Animals↗

A solvent-free, rapid and simple virus RNA-release method for potato leafroll virus detection in aphids and plants by reverse transcription polymerase chain reaction.

A one-step, rapid and economical method for potato leafroll virus (PLRV) RNA release that is applicable to the use on a microcentrifuge scale is described. Discs (3-6 mm diameter) from leaves, petioles, stems, and tubers of potato plants were incubated in microcentrifuge tubes with detergent solution. The supernatants were used directly for reverse transcription (RT) and polymerase chain reaction (PCR). Of the seven nonionic detergents of the TritonX series evaluated, Triton X405R was the most effective, although X-405 and X-1OOR were also effective in releasing PLRV RNA. Application of the detergent method for detecting PLRV in greenhouse-grown potato organs (leaves, petioles, stems, tubers) and in field-grown tubers was demonstrated and compared to the multi-step phenol method. When individual aphids, Myzus persicae, were ground in 20 microl of detergent solution and supernatants were used for RT-PCR, virus was detected in single aphids in undiluted solutions and up to a dilution of 1:4. The concentration of PLRV RNA released by the detergent method was substantially lower than that released by the phenol method. However, the detergent method was sensitive enough to detect PLRV from potato leaves, petioles, and stems 2 weeks after graft inoculation. The detergent method was rapid and economical, and has potential for large-scale application. The extracts survived over 37 days at room temperature, thus making it possible to mail extracts from remote areas lacking specialised RT-PCR facilities to a central laboratory for PLRV testing.

Animals↗

Evaluation of five methods for respiratory syncytial virus detection.

A total of 117 nasal aspirates were cultured for respiratory syncytial virus (RSV) and tested for RSV antigen by a direct fluorescent-antibody (DFA) test (Bartels Immunodiagnostic Supplies, Inc., Bellevue, Wash.), the Directigen enzyme immunoassay (EIA; Becton Dickinson Microbiology Systems, Cockeysville, Md.), the TestPack EIA (Abbott Laboratories, North Chicago, Ill.), and RSV EIA (Abbott). Agreement of two of five methods or a positive RSV culture were required to validate a result. A total of 57 of 117 (48.7%) specimens were culture positive in HEp-2 cells, A549 cells, or both. A total of 5 of 117 (4.3%) additional specimens met the criteria of a positive specimen; i.e., 62 of 117 (53.0%) specimens were positive. Results obtained from 77 of 117 (65.8%) specimens were concordant for all five methods. The sensitivities, specificities, and positive and negative predictive values for the culture and DFA methods were 91.9, 100, 100, and 91.7% and 91.9, 96.4, 96.6, and 91.4%, respectively. The sensitivities, specificities, and positive and negative predictive values for the three EIA procedures, Directigen, TestPack, and RSV EIA, were 75.8, 80.0, 81.0, and 74.6%; 93.6, 100, 100, and 93.2%; and 71.0, 100, 100, and 75.3%, respectively. New self-contained EIA configurations and the DFA method offer attractive alternatives to the culture method. Technical simplicity, rapid turnaround time, performance, and cost must all be considered when selecting a system for RSV detection.

Antigens, Viral↗

[Production of monoclonal antibodies to Lily symptomless virus and application in lily virus detection].

Four hybridoma cell lines, 2A2, 5H9, 5H2 and 5E12, secreting monoclonal antibodies (MAbs) against Lily symptomless virus (LSV) were produced by fusing mouse myeloma cells (SP2/0) with spleen cells from BALB/C immunized by the LSV particles. The four MAbs could specifically react with LSV. The titres of ascitic fluids of the four MAbs are up to 10(-6) in ELISA. Isotypes and subclasses of 5H9 and 5E12 belong to IgG1 while those of 2A2 and 5H2 belong to IgG3. Isotypes of light strains of the four MAbs all belong to kappa. The four MAbs were used in antigen-coated plate (ACP)-ELISA for LSV detection, and ACP-ELISA could successfully detect 1.8 ng of purified LSV or virus in plant sap diluted 1:300. The presence of LSV in field lily tissues was investigated with ACP-ELISA.

Animals↗

Contamination with PCR detectable virus in a virus isolation quality assurance panel.

External quality control schemes are an essential part of the quality assurance of all diagnostic virology laboratories. There are a few providers of nucleic acid detection quality control panels. Consequently, diagnostic laboratories may test panels that are developed specifically for virus isolation by nucleic acid detection methods. Here, we report on a recent simulated eye swab panel from a National external quality assessment service, which was meant for virus isolation but which we tested by polymerase chain reactions assays. The results suggest that the samples had been contaminated at source leading to difficulty in interpretation of the panel and a poor score.

False Positive Reactions↗

Antigenic variation among human strains of influenza C virus detected with monoclonal antibodies to gp88 glycoprotein.

Antigenic variation among influenza C virus strains was investigated with monoclonal antibodies against gp88 glycoprotein. Seven monoclonal antibodies obtained were tentatively classified into two groups, A and B. The group A antibodies had hemagglutination inhibition (HI), hemolysis inhibition and neutralization activities whereas the group B antibodies possessed none of them. A comparison of antigenicity among 15 human strains with these antibodies in radioimmunoprecipitation and HI tests showed that the regions recognized by the group A antibodies undergo considerable changes, whereas those by group B are conserved among the strains.

Animals↗

Human immunodeficiency virus detected in bowel epithelium from patients with gastrointestinal symptoms.

Infectious human immunodeficiency virus (HIV) was recovered from two out of four bowel biopsy specimens from acquired immunodeficiency syndrome (AIDS) patients with chronic diarrhoea of unknown aetiology. In-situ hybridisation of biopsy specimens from rectum and duodenum of other AIDS patients with gastrointestinal complaints showed the presence of HIV-infected cells in both the base of the bowel crypts and the lamina propria. The type(s) of epithelial cell(s) infected could not be determined definitively. However, the association of in-situ labelling of HIV RNA in argentaffin staining cells strongly suggests that enterochromaffin cells derived from neural crest tissue are among the target cells. This evidence that HIV can directly infect the bowel raises the possibility that the virus causes some of the gastrointestinal disorders of AIDS patients.

Acquired Immunodeficiency Syndrome↗

Homologous interference of lymphocytic choriomeningitis virus: detection and measurement of interference focus-forming units.

Lymphocytic choriomeninigitis (LCM) virus defective interfering (DI) particles form foci of protected cells in a monolayer under an agarose-containing overlay medium. Foci originate from one cell dually infected with at least 1 interference focus-forming unit and infectious virus. As a result, an interfering factor is produced and released which interacts with neighboring cells, thereby protecting them against cytopathic lysis by challenge virus. The property of individual LCM virus DI particles to induce countable foci has been made the basis of quantitative assay that is comparable in every respect to the plaque assay of infectious virus and is much more sensitive and probably more accurate than other procedures used to measure LCM virus DI particles. LCM virus was passaged, undiluted, 10 times in cell cultures. When yields were analyzed as to concentrations of PFU and interference focus-forming units, both entities were found to fluctuate with the pattern expected from theoretical considerations.

Cell Line↗

Intrahepatic transfusion-transmitted virus detected by in situ hybridization in patients with liver diseases.

Transfusion-transmitted virus (TTV) has been identified from patients with post-transfusion hepatitis of unknown aetiology, but the clinical relevance remains unclear. The aim of this study was to evaluate TTV in liver. We studied 15 patients with hepatitis non-A-E and 44 with hepatitis B virus (HBV). The nested polymerase chain reaction (PCR) with primers corresponding to the conserved region of the published TTV genome was employed to amplify TTV fragments in serum, and in situ hybridization was used to detect TTV in biopsied liver specimens. TTV DNA was detected in serum from six (40%) of 15 patients with hepatitis of unknown aetiology and from 16 (36.4%) of 44 patients with chronic hepatitis B, respectively. The intrahepatic viral fragment was detected in 17 (77.3%) of 22 patients with TTV in serum. There was no statistical difference in the prevalence of TTV infection between the two groups (hepatitis non-A-E 40% vs HBV 25%, P > 0.75). When patients in both groups, with and without TTV, were compared, no differences were found in serum alanine aminotransferase (ALT) levels (hepatitis non-A-E: 131.5 +/- 66.6 vs 244.2 +/- 257.4, P=0.955; HBV: 240.1 +/- 418.9 vs 214.6 +/- 276.7 U l(-1), P=0.761) or histological activity index (grade) score (hepatitis non-A-E: 6.4 +/- 5.5 vs 5.6 +/- 5.9, P=0.689; HBV: 5.6 +/- 3.7 vs 5.5 +/- 3.7, P=0.345). HBV DNA levels in patients with and without TTV co-infection did not differ significantly (300 +/- 776.4 microg ml(-1) vs 97.1 +/- 160.5 microg ml(-1), P=0.980). Hence, TTV does exist in liver, but plays no role in hepatitis or aggravation of liver damage when co-infected with HBV.

Adult↗

Identification and sequence analysis of hepatitis A virus detected in market and environmental bivalve molluscs.

In Italy in 1998, hepatitis A virus (HAV) was responsible for an infectious disease transmitted by contaminated bivalve molluscs. To determine the presence of HAV in the bivalves collected during a 1-year follow-up study, hepatitis A RNA was extracted and amplified by a nested reverse transcriptase-PCR method overlapping the VP1/2A region. The HAV genome was detected in 24 (14.1%) of 170 samples: 19 clams (Tapes decussates and Tapes semidecussatus), 1 oyster (Crossostea gigas), and 4 mussels (Mytillus galloprovincialis). Eleven positive samples were collected from marketing areas, and 13 positive samples were collected from growing areas. Seventeen of the 24 positive samples had been taken from domestic products, and 7 had been imported. Sequence analysis showed the presence of genotypes IA and IB. Our results suggest significant presence of HAV in bivalves from both marketing (public consumption) and environmental (growing) areas.

Animals↗

[Significance of antibodies to herpesviridae viruses detectable in rheumatic diseases].

AIM: To assay antibodies to cytomegalovirus (CMV), herpes simplex virus type 1 and 2 (HSV-1, HSV-2) and Epstein-Barr virus (EBV) in rheumatic patients and to clarify clinical correlations. MATERIALS AND METHODS: A total of 66 patients were examined: 7, 19, 6, 3, 5, 2 and 24 with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), reactive arthritis (ReA), scleroderma systematica (SS), erythema nodosum (EN), hemorrhagic vasculitis (HV), active or chronic viral infection (A/CVI), respectively. Clinical, laboratory tests, tests for specific IgM- and IgG-antibodies to CMV, HSV-1, HSV-2, EBV, x-ray examinations were performed. RESULTS: IgG-antibodies to CMV were detected in 79%, VCA-IgG-antibodies to EBV in 70.3%, EA-IgG-antibodies to EBV in 56.6%, IgG-antibodies to HSV-1 in 42.1% of patients. Active CMV infection was diagnosed in 27.8%, active EBV infection in 56.6%, combination of CMV and EBV infection in 46.9% of cases. High titers of antibodies to CMV and EBV correlated with such symptoms as fever, arthritis, myalgia, carditis, hepatomegalia, migrating erythematous eruption. Acute-phase indices were related to high titers of antibodies to CMV and EBV. Elevated titers of antibodies to CMV and EBV were registered both in untreated patients and in patients treated with corticosteroids, nonsteroid antiinflammatory drugs and aminoquinoline drugs. CONCLUSION: In differential diagnosis of rheumatic diseases it is necessary to consider possibility of CMV and EBV infections. If these are detected, antiviral measures should be taken.

Antibodies, Viral↗

Neutralizing antibodies to type 1 and 2 bovine viral diarrhea viruses: detection by inhibition of viral cytopathology and infectivity by immunoperoxidase assay.

Neutralizing antibodies to type 1 and 2 bovine viral diarrhea virus (BVDV) strains were measured by a microtiter virus neutralization test (MVNT) in cell culture. Antibodies (neutralizing) were detected by inhibition of viral infectivity, by the absence of viral cytopathology for cytopathic strains, or by immunoperoxidase staining for noncytopathic strains. The immunoperoxidase-stained monolayers could be detected without the aid of light microscopy. Twenty BVDV strains were used as challenge viruses in the in vitro MVNT, including 14 type 1 and 6 type 2 strains. Representative noncytopathic and cytopathic strains of both types were used. Positive control serum samples available for diagnostic testing contained both type 1 and type 2 BVDV antibodies. There did not appear to be major differences in antibody titers among the respective type strains, regardless of biotype (cytopathic or noncytopathic). In a study with sera from calves receiving a modified live virus or inactivated BVDV vaccine, the calves receiving type 1 strains responded with higher antibody titers to type 1 strains than to type 2 strains.

Animals↗

Prospective comparison of R-mix shell vial system with direct antigen tests and conventional cell culture for respiratory virus detection.

BACKGROUND AND OBJECTIVES: Conventional cell culture (CC) has limited clinical utility as a result of the extended incubation period often required for virus isolation. Alternative methodologies have been introduced in an effort to improve turnaround times. One such system, the R-mix shell vial is discussed herein. The study objectives were: (a) to establish R-mix testing parameters as compared to direct antigen testing (DAT) and CC, and (b) to assess technical aspects and cost of R-mix in a high volume clinical virology laboratory. STUDY DESIGN: A prospective analysis of respiratory samples submitted to the clinical virology laboratory between November 2004 and April 2005 was performed. All specimens were inoculated onto R-mix shell vials (SV) and CC tubes; and a subset also underwent DAT for influenza A and B and/or RSV. A retrospective estimated cost analysis was made. RESULTS: A total of 563 samples were included in the study, which collectively revealed a total of 207 viruses. Sensitivity of R-mix for seven major respiratory viruses ranged from 45% to 83% compared to CC and DAT, while mean time to detection (TTD) varied from 1.1 to 1.4 days. In addition to these viruses, 23 picornaviruses, 11 CMV isolates and 5 HSV isolates were detected by CC alone. CONCLUSIONS: The R-mix system has similar sensitivity as CC for the detection of parainfluenza 1-3 and influenza A/B while dramatically reducing the TTD. Furthermore, it is significantly more sensitive and produces more timely results for RSV than CC; yet, neither method offers a diagnostic benefit over rapid DAT for RSV detection. The sensitivity of R-mix for adenovirus appears to be significantly lower than that of CC. Lastly, methodologies other than R-mix must remain in place under circumstances where identification of other potential viral respiratory pathogens, including herpesviruses and picornaviruses, is desired.

Adenoviruses, Human↗

Natural selection for rash-forming genotypes of the varicella-zoster vaccine virus detected within immunized human hosts.

The Oka vaccine strain is a live attenuated virus that is routinely administered to children in the United States and Europe to prevent chickenpox. It is effective and safe but occasionally produces a rash. The vaccine virus has accumulated mutations during its attenuation, but the rashes are not explained by their reversion, unlike complications reported for other viral vaccines. Indeed, most of the novel mutations distinguishing the Oka vaccine from the more virulent parental virus have not actually become fixed. Because the parental alleles are still present, the vaccine is polymorphic at >30 loci and therefore contains a mixture of related viruses. The inoculation of >40 million patients has consequently created a highly replicated evolutionary experiment that we have used to assess the competitive ability of these different viral genotypes in a human host. Using virus recovered from rash vesicles, we show that two vaccine mutations, causing amino acid substitutions in the major transactivating protein IE62, are outcompeted by the ancestral alleles. Standard interpretations of varicella disease severity concentrate on the undeniably important effects of host genotype and immune status, yet our results allow us to demonstrate that the viral genotype is associated with virulence and to identify the key sites. We propose that these loci have pleiotropic effects on the immunogenic properties of the virus, rash formation, and its epidemiological spread, which mould the evolution of its virulence. These findings are of practical importance for reducing the incidence of vaccine-associated rash and promoting public acceptance of the vaccine.

Chickenpox Vaccine↗