Detection of viral DNA in hybridization reactions using two chemiluminescent substrates.
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Cloning, Molecular↗
Biomedical subjects
M Musiani
Publications and source records attributed to M Musiani.
Viral diagnosis using hybridization assays with digoxigenin labeled probes.
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DNA Probes↗
Rapid diagnosis of cytomegalovirus encephalitis in patients with AIDS using in situ hybridisation.
AIMS: To evaluate the presence of cytomegalovirus (CMV) DNA in the cerebrospinal fluid of patients with AIDS and suspected viral encephalitis using an in situ hybridisation assay with digoxigenin labelled CMV DNA probes. METHODS: The presence of CMV DNA was evaluated in cerebrospinal fluid cells of 10 patients with AIDS using in situ hybridisation. The positivity of CMV DNA was confirmed by the presence of CMV induced antigens in the same specimens. The presence of CMV DNA and CMV induced antigens was also analysed in peripheral blood leucocytes. The time required to perform the in situ hybridisation assay was about eight hours. RESULTS: The in situ hybridisation assay was sensitive, specific, and provided good resolution. Six patients proved positive for the presence of CMV DNA in CSF cells and all six also proved positive for CMV DNA in blood leucocytes. Of the six CMV positive patients, five were treated with specific antiviral drugs: of these, one died during the treatment while four clinically recovered after one month of treatment. CONCLUSIONS: The in situ hybridisation assay using digoxigenin labelled CMV DNA probes can be used as a valuable diagnostic test for the detection of CMV DNA in the cerebrospinal fluid cells of patients with suspected CMV encephalitis and can therefore prompt adequate antiviral therapeutic intervention.
AIDS-Related Opportunistic Infections↗
Human papillomavirus type 16-associated periungual squamous cell carcinoma in a patient with acquired immunodeficiency syndrome.
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Acquired Immunodeficiency Syndrome↗
Evaluation of strand-specific RNA probes visualized by colorimetric and chemiluminescent reactions for the detection of B19 parvovirus DNA.
A dot-blot hybridization assay was developed to detect B19 DNA using strand-specific RNA probes labelled with digoxigenin. The sensitivity of the assays was evaluated either using 'plus' and 'minus' sense RNA probes in two different hybridization assays, or in two successive reactions of the same assay. The hybridized probes were revealed immunoenzymatically using anti-digoxigenin Fab fragments conjugated with alkaline phosphatase. The enzyme was visualized by colorimetric reaction. Since 'minus' sense RNA probe gave the best results in the dot-blot procedures, we increased the sensitivity of the hybridization assay visualizing the 'minus' sense digoxigenin-labelled RNA probe by chemiluminescent reaction. In these experimental conditions up to 20 fg of target B19 DNA could be visualized. In the search for B19 DNA, 4656 serum samples were analyzed by chemiluminescent reaction of 'minus' sense digoxigenin-labelled RNA probe and for comparison with the digoxigenin-labelled DNA probe. Positive results were confirmed by Southern blotting. Out of 4656 serum samples analyzed, 4648 gave negative results, 1 resulted positive to all the hybridization assays, 6 only using RNA probe and 1 only by DNA probe.
Adult↗
Nested polymerase chain reaction assay for the detection of B19 parvovirus DNA in human immunodeficiency virus patients.
Persistent B19 parvovirus infection has been recognized in immunocompromised patients, often occurring with a low-titer viremia. In this study, nested polymerase chain reaction (PCR) for the detection of B19 parvovirus DNA was carried out on the sera of 49 human immunodeficiency virus (HIV)-1-seropositive patients, negative for the detection of B19 DNA at dot blot hybridization assay and with different values of serum anti-B19 IgM (27 patients proved positive and 22 negative). Of the 49 HIV-seropositive samples tested by nested PCR, seven were positive for the detection of B19 DNA. All seven belonged to the group of subjects seropositive for specific anti-B19 IgM. The study shows that, in the presence of specific B19 IgM, circulating virus may still be present but can be detected only by PCR. In that B19 infection can occur with low-titer viremia in immunocompromised patients, PCR may be the only method for virus detection.
Adult↗
In situ detection of B19 DNA in bone marrow of immunodeficient patients using a digoxigenin-labelled probe.
An in situ hybridization assay using a digoxigenin-labelled probe was developed to detect B19 DNA in bone marrow erythroid elements of immunodeficient patients with hypoplastic anaemia. A 700 bp Bam HI-Hin dIII fragment of B19 DNA was used to construct the probe by incorporating deoxyuridine triphosphate labelled with digoxigenin. The in situ hybridized B19 DNA probe was visualized by an immunoenzymatic reaction using antidigoxigenin Fab fragments labelled with alkaline phosphatase. Dark blue coloured inclusions at the enzyme site were detected in the nuclei of B19 infected erythroid cells at different stages of cell differentiation. Six out of the nine patients studied showed a positive reaction by in situ hybridization assay. The assay we developed proved highly specific and sensitive and it appears to be a suitable diagnostic test for investigating the possible role of B19 infection as a cause of haematopoietic disorders in immunocompromised hosts.
Anemia, Aplastic↗
Microplate capture hybridization of amplified parvovirus B19 DNA fragment labelled with digoxigenin.
A capture hybridization technique in microplate has been developed for the identification of polymerase chain reaction (PCR) amplified B19 DNA fragment in clinical specimens. The amplified 104 bp B19 DNA fragment, located in the gene coding for structural proteins, was directly labelled during the amplification reaction by incorporation of digoxigenin-labelled dUTP. The amplified product was then captured by a probe immobilized on microplate wells. The capture hybridization reaction was visualized as an enzyme-linked immunosorbent assay using anti-digoxigenin Fab fragment labelled with peroxidase. Thirty-five serum samples were tested by our capture hybridization assay and the results were in accordance with the results obtained by Southern blot analysis of PCR amplified product. Our microplate capture hybridization assay showed a high sensitivity and reproducibility and appears to be a practical and reliable test for routine screening of B19 parvovirus DNA in clinical specimens.
Base Sequence↗
Efficient parvovirus B19 DNA purification and molecular cloning.
A simple and efficient method of purification and molecular cloning of Parvovirus B19 DNA directly from small quantities of viremic sera was developed. Purified virions were lysed in annealing conditions, then viral DNA purification in double strand (ds) DNA form was achieved using an affinity DNA binding matrix. Affinity purification yielded a consistently high recovery of viral DNA. Using affinity purified ds viral DNA, we efficiently and stably cloned the complete coding internal unique sequence of B19 DNA. In our cloning strategy AatII and BamHI restriction endonuclease sites were exploited. This permitted cleavage of the 5.0 kbp AatII fragment in two AatII-BamHI fragments which could be efficiently cloned in a directional way in pUC18 plasmid vector. The availability of the two cloned AatII-BamHI fragments thus allowed the construction of a full length clone in a single ligation reaction.
Cloning, Molecular↗
Symptomatic parvovirus B19 infection of one fetus in a twin pregnancy.
Twin pregnancies complicated by infection due to parvovirus B19 are uncommon. We report a case in which only one fetus developed a symptomatic infection, which presented at first as ascites and pleural effusion; later, meconium peritonitis developed. Hydrops spontaneously resolved, and at birth meconium peritonitis was successfully treated with surgery. However, even with the positive outcome of this pregnancy, a long-term follow-up is needed to exclude damage other than injury to the erythropoietic system.
Adult↗
In situ hybridization at the ultrastructural level: localization of cytomegalovirus DNA using digoxigenin labelled probes.
We describe a procedure for detecting and localizing cytomegalovirus DNA sequences based on in situ hybridization at the ultrastructural level. A digoxigenin-labelled probe, identified with an anti-digoxigenin colloidal gold-labelled antiserum, was employed on infected cells embedded in a new acrylic resin (Bioacryl). The silver enhancement method on the same specimen was used to more easily reveal the reaction also at low magnification. The immunolocalization was characterized by high specificity with virtually no background staining and a good maintenance of submicroscopic cell features.
Acrylic Resins↗
Different syndromes associated with B19 parvovirus viraemia in paediatric patients: report of four cases.
The broad spectrum of clinical manifestations associated with B19 parvovirus often allows the infection to go unrecognized. We tested for the presence of B19 parvovirus and the specific serological response in serum from hospitalized patients submitted for viral investigations without any specific indications for B19 parvovirus. We diagnosed human parvovirus B19 infection in four paediatric patients showing different clinical manifestations. The patients, aged between 5 and 8 years, were admitted to hospital for: (1) petechial rash; (2) mononucleosis-like syndrome; (3) neurological syndrome; and (4) respiratory disease (in an immunodeficient patient).
Child↗
Detection of CMV DNA in clinical samples of AIDS patients by chemiluminescence hybridization.
A sensitive chemiluminescence dot-blot hybridization assay for the detection of CMV DNA in clinical samples of AIDS patients is described. In the chemiluminescence hybridization assay, digoxigenin-labelled CMV DNA probes were used and when hybridized they were detected by anti-digoxigenin Fab fragments conjugated with alkaline phosphatase. Adamantyl 1,2-dioxetane phenyl phosphate was used as the chemiluminescent substrate. The results were recorded by instant photographic films. The results obtained with the chemiluminescence hybridization assay were compared with the results obtained by hybridization with colourimetric detection. The chemiluminescent assay proved specific, sensitive and reliable and thus can be used as a valuable routine diagnostic test for the detection of CMV DNA in clinical samples.
Acquired Immunodeficiency Syndrome↗
Double in situ hybridization for detection of Herpes simplex virus and cytomegalovirus DNA using non-radioactive probes.
We describe a double in situ hybridization assay for the simultaneous detection of Herpes simplex virus (HSV) and cytomegalovirus (CMV) DNA in infected cell cultures using non-radioactive-labeled probes. This work used a biotinylated HSV DNA probe, which can be revealed by an avidin-biotin-peroxidase complex and a digoxigenin-labeled CMV DNA probe, visualized by anti-digoxigenin F(ab) fragments conjugated with alkaline phosphatase. Light microscopy visualization was achieved by the contrasting colors of appropriate peroxidase and alkaline phosphatase reaction products (red and dark blue, respectively). The time required to perform the double hybridization assay was about 3 hr. This double hybridization assay proved to be sensitive, specific, and provided good resolving power.
Acquired Immunodeficiency Syndrome↗
Chemiluminescent assay for the detection of viral and plasmid DNA using digoxigenin-labeled probes.
A dot-blot hybridization immunoenzymatic assay with a chemiluminescent endpoint was developed for the rapid and sensitive detection of viral and plasmid DNAs. Digoxigenin-labeled probes were used to detect cytomegalovirus, parvovirus B19, and plasmid pBR328 DNAs. Hybridized probes were immunoenzymatically visualized by anti-digoxigenin Fab fragments labeled with alkaline phosphatase, and adamantyl 1,2-dioxetane phenyl phosphate was used as chemiluminescent substrate. Results were recorded by instant photographic films. The chemiluminescent hybridization assay was performed in about 8 hr and was able to detect as little as 50-10 fg of homologous target DNA.
Cytomegalovirus↗
Chemiluminescence dot blot hybridization assay for detection of B19 parvovirus DNA in human sera.
A chemiluminescence dot blot hybridization assay was used for the detection of B19 parvovirus DNA in human sera by using digoxigenin-labeled probes. The probes were revealed immunoenzymatically by use of anti-digoxigenin Fab fragments conjugated with alkaline phosphatase. The chemiluminescence signal was obtained by reacting the labeled probe-target complex with an enzyme-triggerable dioxetane substrate. The emitted photons were detected with instant photographic films. In the search for B19 parvovirus DNA, 2,808 serum samples were analyzed.
DNA Probes↗
5-Azacytidine induction of a cellular heat shock protein and expression of the major immediate early protein of human cytomegalovirus in Vero cells.
Human cytomegalovirus can support an abortive infection in Vero cells and only some immediate early events are expressed in a low proportion of the cell population. It has been shown that cellular factors partially remove blocks in cells abortively or latently infected by HCMV, whereas 5-azacytidine is known to act on gene expression and cell differentiation. In this work we present evidence that the treatment of HCMV infected Vero cells with 5-azacytidine induces the expression of the major immediate early protein (68K) of Human cytomegalovirus by enhancing a 72K cellular heat shock protein.
Animals↗
[A case of monolateral pulmonary pathology treated with independent lung ventilation continuous monitoring of mixed venous oxygen saturation].
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Aged↗