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Biomedical subjects

K McIntosh

Publications and source records attributed to K McIntosh.

At least 127 records · Page 7Linked to original sources
PubMed1986

Comparison of washed nasopharyngeal cells and whole nasal secretions for detection of respiratory syncytial virus antigens by enzyme-linked immunosorbent assay.

We compared washed nasal epithelial cells with unfractionated nasal secretions as sources of respiratory syncytial virus (RSV) antigens in an indirect enzyme-linked immunosorbent assay (ELISA). Of 28 infants positive for RSV by virus isolation or direct immunofluorescence or both, 27 (96%) were positive by ELISA with whole nasal secretions, whereas only 19 (68%) were positive by ELISA with the matching washed-cell fractions. Furthermore, the ELISA absorbances obtained with nasal secretions were significantly greater than those seen with washed-cell fractions, indicating that whole nasal secretions contain relatively greater amounts of RSV antigens as measured by ELISA.

Antigens, Viral↗
PubMed1986

Evaluation of a commercially available direct immunofluorescent staining reagent for the detection of respiratory syncytial virus in respiratory secretions.

A commercially-available direct immunofluorescence (IF) reagent (Imagen; Boots-Celltech, Slough, Berkshire, United Kingdom) was similar in sensitivity and specificity to the conventional indirect IF test for the detection of respiratory syncytial virus in respiratory secretions. Both IF tests were more sensitive than culture, particularly for specimens transported from outside the institution.

Antibodies, Monoclonal↗
PubMed1986

Neonatal mastitis.

Forty-one cases of neonatal mastitis seen at Children's Hospital, Boston since 1947 have been analyzed and the literature since 1950 reviewed. All 41, like those in the literature, occurred in full-term infants 1-5 weeks of age, with a sex ratio of 2:1 (females:males). Bilaterality was rare (3) cases in this series, one in the literature review) and systemic spread or extramammary foci even rarer. The incidence has changed little in the past 35 years except for the larger number of cases in the 1950s. In the present series, all but a few cases have been caused by Staphylococcus aureus, and gram-negative enteric bacilli have not been seen. Therapy is surgical incision and drainage when fluctuance is present, but early treatment with appropriate intravenous antibiotics has apparently obviated the need for surgery in many recent cases. The prognosis for cure of the infection is excellent.

Female↗
PubMed1985

Risk of illness after exposure to a pediatric office.

To determine whether well children visiting a pediatrician's office are at risk of acquiring common communicable diseases, we conducted a prospective cohort study during the winter of 1983-1984. The occurrence of respiratory or gastrointestinal illness or fever in young children in the week after a visit to a pediatric office (office group) was compared with the occurrence of these illnesses in a similar group of children (home group) not exposed to the office during the study period. One home comparison subject was matched by age and sex to each of 127 children three years of age and under who were seen for well-child care in a private pediatric office with a common waiting room. The adjusted relative risk of the development of illness during the study week for the office group as compared with the home group was 0.95 (95 per cent confidence interval, 0.66 to 1.37), indicating no effect. We conclude that exposure to a pediatric office is not an important cause of the common infections in young children that have incubation periods of a week or less.

Child Health Services↗
PubMed1985

Monoclonal capture antibody ELISA for respiratory syncytial virus: detection of individual viral antigens and determination of monoclonal antibody specificities.

An enzyme-linked immunosorbent assay (ELISA) for respiratory syncytial virus (RSV) that employs solid-phase monoclonal antibodies was developed. RSV antigens bound by these monoclonal capture antibodies were detected by addition of a polyclonal bovine antiserum, followed anti-bovine enzyme conjugate and enzyme substrate. The sensitivity and specific of the assay were determined by titrations of the solid-phase antibodies and by antigen titrations with both unpurified RSV-infected cell culture material and purified RSV nucleocapsids. The addition of a competitive binding step prior to the addition of antigen to the solid-phase antibody provides further evidence of the assay's specificity. Furthermore, the competitive binding assay enables the antigen specificity of monoclonal antibodies to be determined or compared without the use of purified antigens. Monoclonal capture ELISA is a convenient, rapid, and sensitive assay that can be used to measure specific RSV antigens in unpurified preparations as well as to determine anti-RSV antibody specificity and should prove useful in examining other complex antigen-antibody systems.

Antibodies, Monoclonal↗
PubMed1985

Treatment of experimental myasthenia gravis with cyclosporin A.

Cyclosporin A (CsA) is an immunosuppressive agent that has recently been used to prevent rejection of transplanted tissues. The effects of CsA treatment of rats with experimental autoimmune myasthenia gravis (EAMG), an antibody-mediated autoimmune disorder of acetylcholine receptors (AChRs) at neuromuscular junctions, have been studied. CsA treatment at the time of primary immunization suppressed the antibody responses to AChR virtually completely. Following 12 weeks of CsA, the AChR-immunized rats responded like naive controls to a further challenge of AChR. Treatment of ongoing EAMG resulted in a reduction of AChR antibody by more than 50%. The secondary response to a challenge of AChR was prevented by CsA treatment, but a very large challenge dose in adjuvant partially overwhelmed the effect of CsA. CsA treatment also prevented the loss of AChRs at neuromuscular junctions, as compared with untreated EAMG controls (P less than 0.02). The efficacy of CsA in suppressing ongoing and secondary hetero- and autoimmune responses against AChR in EAMG encourages its ultimate application in autoimmune diseases of man, such as MG. Its usefulness will depend on the ability to determine effective doses of CsA that are well tolerated.

Animals↗
PubMed1985

Antigenic characterization of respiratory syncytial virus strains with monoclonal antibodies.

To study the antigenic characteristics of respiratory syncytial virus (RSV), we developed and evaluated monoclonal antibodies (MAbs) to three strains of RSV: 11 to Long, 4 to 18537, and 9 to A2. Six of these MAbs immunoprecipitated the nucleoprotein, six the large glycoprotein, and 11 the fusion protein. By the pattern of the reactions of these MAbs to 16 strains of RSV in an indirect immunofluorescence assay or enzyme-linked immunosorbent assay, we were able to distinguish three subgroups. With a panel of 10 of these 24 MAbs, we tested 26 strains isolated between 1979 and 1982 in Boston and found that 22 belonged to group 1, 4 to group 2, and none to group 3. The pattern of the reactions of the MAbs against representative strains from the three groups identified nine epitopes by indirect immunofluorescence assay: three of each on the nucleoprotein, the large glycoprotein, and the fusion protein. These results, along with those of previous studies, suggest that groups 1 and 3 are antigenically similar and group 2 is antigenically more distinct.

Antibodies, Monoclonal↗
PubMed1985

Quantification of respiratory syncytial virus polypeptides in nasal secretions by monoclonal antibodies.

An indirect enzyme-linked immunosorbent assay (ELISA) which uses monoclonal antibody as solid-phase immunosorbent was developed to measure specific polypeptides of respiratory syncytial virus (RSV). The assay was used to examine 43 nasopharyngeal (NP) aspirates from RSV-positive infants that had been examined previously for RSV by culture, direct immunofluorescence, and polyclonal antibody ELISA. Frozen NP aspirates were serially diluted and examined for the 66K mol. wt. fusion glycoprotein (F), the 84K large surface glycoprotein (G) and the 41K nucleoprotein (N) by monoclonal capture ELISA. F protein was detected in all 43 specimens, G protein was detectable in 20 (47%) and N protein in 22 (51%) of 43 NP aspirates. In specimens with detectable G and N proteins, F was detected by endpoint titration at approximately tenfold greater dilutions than either G or N. In 19 sequential NP aspirates from five patients with RSV infection, F was present in higher titre throughout infection. In 20 cases, matching cell culture isolates were examined by immunofluorescence with strain-specific monoclonal antibodies. Three of 20 isolates showed strain-specific differences by their lack of reaction with anti-G monoclonal antibody. Titration of the 20 cell culture isolates by monoclonal antibody capture ELISA showed the relative amount of F and N proteins to be equal in all cases, whereas levels of G protein tended to be slightly lower. Reconstruction experiments with NP aspirates demonstrated that degradation of F and N proteins did not occur in NP aspirates, but that G protein antigenicity appeared to be affected by nasal secretions. When compared with cell culture-grown material, nasal secretions contained abundant F protein but a surprisingly low concentration of N protein.

Antibodies, Monoclonal↗
PubMed1984

Treatment of respiratory viral infection in an immunodeficient infant with ribavirin aerosol.

An infant with severe combined immunodeficiency syndrome (SCIDS) secondary to adenosine deaminase deficiency had pneumonitis and combined infection with respiratory syncytial virus (RSV) and parainfluenza virus type 3 (PIV3). Four separate courses of ribavirin were delivered by small-particle aerosol. The PIV3 disappeared during the first course, and RSV disappeared after the fourth course on the 58th hospital day. Neither virus returned during profound immunosuppression for bone marrow transplantation. Secretory antibody to both viruses was found and may have assisted in recovery. Strains of RSV from the 9th, 15th, 29th, and 55th hospital days showed similar sensitivities to ribavirin in vitro. Ribavirin can be a useful drug in the treatment of respiratory viral infections in patients with SCIDS.

Adenosine Deaminase↗
PubMed1984

Monoclonal antibodies for the rapid diagnosis of respiratory syncytial virus infection by immunofluorescence.

Eight separate monoclonal antibodies to the Long strain of respiratory syncytial virus (RSV) were tested for their utility as rapid diagnostic reagents in immunofluorescence. Preliminary screening indicated that all 8 reacted with 11 field strains from three previous local RSV outbreaks and with 4 of 5 additional strains chosen because of their antigenic diversity by neutralization. Two monoclonal antibodies, one each directed against a surface glycoprotein and the nucleocapsid protein, were then compared, singly and combined, with a polyclonal antiserum as diagnostic reagents in 209 consecutive samples submitted to our diagnostic laboratory. Agreement between the two monoclonal antibodies was 100% and between them and the polyclonal serum was 98%. Sensitivity in relation to culture was 96-98%. Monoclonal antibodies are excellent immunofluorescent diagnostic reagents; antigenic diversity among RSV strains was not an impediment to their use in this study.

Antibodies, Monoclonal↗
PubMed1984

A simultaneous outbreak of respiratory syncytial virus and parainfluenza virus type 3 in a newborn nursery.

Over a 3-week period, 20 of 34 (59%) infants in a newborn nursery developed nosocomial viral respiratory tract disease. Either respiratory syncytial virus (seven infants) or parainfluenza virus type 3 (five) or both (two) were demonstrated in respiratory secretions from 14 of the 20 symptomatic patients. Symptoms in the 20 infants included rhinitis (15 infants), cough (14), apnea (eight), pulmonary infiltrates (seven), and fever (six). There were no differences in symptoms between children infected with respiratory syncytial virus alone, with parainfluenza virus alone, or with both viruses concurrently. Patients were clustered in the nursery by agent: infants with the same virus tended to share contiguous bed spaces, supporting the concept that parainfluenza virus as well as respiratory syncytial virus can be transmitted from patient to patient. In addition to this risk for contiguous bed spaces, the presence of a nasogastric tube was associated with risk of illness (P less than 0.05). In the presence of a nursery outbreak of respiratory tract disease, more than one virus may circulate concurrently, and an individual patient may be infected simultaneously by more than one virus.

Boston↗
PubMed1983

Comparison of a monoclonal antibody with a polyclonal serum in an enzyme-linked immunosorbent assay for detecting adenovirus.

To develop and evaluate an enzyme-linked immunosorbent assay (ELISA) for detecting adenovirus antigens in which a group-specific monoclonal antibody to the adenovirus hexon is used, we studied two different ELISA test systems. The test system which was the most sensitive and specific was then compared in parallel tests with a similarly constructed ELISA in which a mouse polyclonal serum was used. Both the ELISA with the monoclonal antibody and that with the polyclonal serum detected purified hexon and 15 different adenovirus types with similar sensitivities. The two assays also showed no reaction with 23 heterologous viruses. Both tests detected adenovirus in stool and respiratory tract specimens tested for adenovirus by standard tissue culture techniques with similar sensitivities and specificities, but neither was sufficiently sensitive for routine testing of these types of clinical specimens. However, the ELISA with the monoclonal antibody proved to be a good test for the noncultivatable adenoviruses, detecting 12 of 12 stool samples that were positive by electron microscopy. The monoclonal antibody proved to be as sensitive and specific as the polyclonal serum and has the advantage that it can be produced in unlimited quantities and needs to be characterized only once.

Adenoviridae↗
PubMed1982

Enzyme-linked immunosorbent assay for detection of respiratory syncytial virus infection: development and description.

An indirect enzyme-linked immunosorbent assay for detection of respiratory syncytial virus (RSV) antigens was developed, using commercially available antisera. Horse anti-RSV and calf antiserum to bovine RSV were used as capture and detector antibodies, respectively. The assay could detect as few as 50 PFU of unpurified RSV per ml in infected cell culture supernatant fluids and as little as 10 ng of affinity-purified RSV antigen per ml. No cross-reactions were observed with heterologous virus types. Freeze-thaw treatment had no effect on RSV enzyme-linked immunosorbent assay titers, but viral transport medium inhibited RSV enzyme-linked immunosorbent assay titers from 10- to 100-fold. The assay can be easily performed in 24 h and is a sensitive and specific method for the detection of RSV antigens.

Acetylcysteine↗
PubMed1982

Enzyme-linked immunosorbent assay for detection of respiratory syncytial virus infection: application to clinical samples.

An enzyme-linked immunosorbent assay (ELISA) for respiratory syncytial virus antigens was applied to the rapid diagnosis of acute infections in children and was compared with viral culture and immunofluorescence tests. The ELISA test employed commercially available reagents and was run on a day-to-day basis as specimens were received in the laboratory. Sensitivity and specificity by ELISA were 82 and 95%, respectively, compared with culture. In the same specimens, the sensitivity and specificity by immunofluorescence were 86 and 96%, respectively. Nasopharyngeal aspirates were proven to be a better source of viral antigen than were nasopharyngeal swabs. ELISA-positive samples remained positive even when left unrefrigerated for a week or mailed to the laboratory in plastic containers. Respiratory syncytial virus ELISA, like culture, became negative as the disease progressed and showed no superiority over culture for diagnosis late in the illness.

Antigens, Viral↗