Search PubMed⌕ Search

Biomedical subjects

L J Anderson

Publications and source records attributed to L J Anderson.

At least 163 records · Page 9Linked to original sources
PubMed1986

The role of parvovirus B19 in aplastic crisis and erythema infectiosum (fifth disease).

In 1984, simultaneous outbreaks of aplastic crisis and erythema infectiosum occurred in northeastern Ohio. Sera were analyzed from 26 patients with aplastic crisis: 24 had IgM specific for parvovirus B19, five had B19-like particles by electron microscopy, and 13 had DNA from B19; no sera from 33 controls had evidence of recent infection with B19 (P less than .0001). DNA from B19 was also detected in specimens of throat gargle and urine from two patients with aplastic crisis. Sera from 36 of 51 children with erythema infectiosum had B19-specific IgM, compared with serum from one of 42 susceptible controls (P less than .0001). DNA from B19 was detected in sera from only two of 51 patients who had erythema infectiosum. The secondary attack rates among susceptible contacts decreased with age (overall total, 49.6%). Differential rates of asymptomatic infection were observed among black (68.8%) and white (20.0%) household members (P = .003). These were the first identified simultaneous outbreaks of aplastic crisis and erythema infectiosum. Their occurrence provided an opportunity to study the epidemiology and spectrum of B19 infection with geographically and temporally matched comparison groups; our results support the hypothesis that infection with parvovirus causes these two clinical entities.

Adolescent↗
PubMed1986

Identification of epitopes on respiratory syncytial virus proteins by competitive binding immunoassay.

To characterize the interrelationship of monoclonal antibodies (MAbs) against respiratory syncytial virus (RSV) and their respective epitopes, we developed a competitive binding assay based on the biotin-avidin system and a tissue culture enzyme-linked immunosorbent assay. The competitive binding assay clearly distinguished between competing and noncompeting MAbs. Eight MAbs against the fusion protein (F protein) demonstrated two blocking patterns consistent with two antigenic sites. MAbs reacting at one site neutralized the virus, while those reacting at the other site did not. Eight MAbs against the large glycoprotein (G protein) demonstrated five blocking patterns consistent with three antigenic sites, one with three epitopes and the other two with one each. None of the MAbs against G protein neutralized the virus. The reaction pattern of the MAbs against three strains of RSV identified three additional epitopes on the F protein and no additional epitopes on the G protein. The epitopes on G protein showed the greatest antigenic diversity among the three strains. These results help us better understand the functional and antigenic structure of the two surface glycoproteins of RSV.

Animals↗
PubMed1986

Detection of antibodies and antigens of human parvovirus B19 by enzyme-linked immunosorbent assay.

Acute-phase serum from a patient with aplastic crisis provided sufficient human parvovirus B19 to make a monoclonal antibody against B19 and to develop antigen and immunoglobulin M (IgM) and IgG antibody detection enzyme-linked immunosorbent assays (ELISAs). The indirect capture antibody method was used for all three assays. Antigen was detected in 8 of 29 sera drawn within 2 days of onset of illness from patients with aplastic crisis. These sera had high titers of virus by electron microscopy and DNA hybridization and had no detectable B19 antibody. Antigen was not detected in serum specimens that had low titers of B19 DNA and had B19 antibody. With the IgM ELISA, we detected B19 IgM in over 85% of clinical cases of aplastic crisis and fifth disease and less than 2% of controls. The prevalence of B19 IgG antibodies increased with age. Approximately 2% of children less than 5 years of age and 49% of adults greater than 20 years of age had B19 IgG antibodies. The B19 antibody ELISAs are sensitive and specific tests to detect B19 infections.

Adolescent↗
PubMed1986

Identification of the major structural and nonstructural proteins encoded by human parvovirus B19 and mapping of their genes by procaryotic expression of isolated genomic fragments.

Plasma from a child with homozygous sickle-cell disease, sampled during the early phase of an aplastic crisis, contained human parvovirus B19 virions. Plasma taken 10 days later (during the convalescent phase) contained both immunoglobulin M and immunoglobulin G antibodies directed against two viral polypeptides with apparent molecular weights of 83,000 and 58,000 which were present exclusively in the particulate fraction of the plasma taken during the acute phase. These two protein species comigrated at 110S on neutral sucrose velocity gradients with the B19 viral DNA and thus appear to constitute the viral capsid polypeptides. The B19 genome was molecularly cloned into a bacterial plasmid vector. Restriction endonuclease fragments of this cloned B19 genome were treated with BAL 31 and shotgun cloned into the open reading frame expression vector pJS413. Two expression constructs containing B19 sequences from different halves of the viral genome were obtained, which directed the synthesis, in bacteria, of segments of virally encoded protein. These polypeptide fragments were then purified and used to immunize rabbits. Antibodies against a protein sequence specified between nucleotides 2897 and 3749 recognized both the 83- and 58-kilodalton capsid polypeptides in aplastic plasma taken during the acute phase and detected similar proteins in the tissues of a stillborn fetus which had been infected transplacentally with B19. Antibodies against a protein sequence encoded in the other half of the B19 genome (nucleotides 1072 through 2044) did not react specifically with any protein in plasma taken during the acute phase but recognized three nonstructural polypeptides of 71, 63, and 52 kilodaltons present in the liver and, at lower levels, in some other tissues of the transplacentally infected fetus.

Adolescent↗
PubMed1986

Meniscal injuries: detection using MR imaging.

Both retrospective and blinded analyses of thin-section, high-resolution magnetic resonance (MR) images of the knee joint, produced using a solenoid surface coil, indicate that MR imaging is an effective technique for evaluating meniscal injuries. Images of 49 patients were evaluated, and the results were correlated with those of subsequent arthroscopy. A grading scale was developed to rate the index of suspicion of a meniscal tear based on the MR images. Overall, approximately 80% of menisci rated grade 4 (definite tear) or 3 (probable tear) were found to have corresponding tears at arthroscopy. In many other patients with a grade 4 or 3 meniscus in whom a corresponding tear was not found arthroscopically, meniscal tears at other sites or other abnormalities were correctly diagnosed using MR. A majority of the false-positive MR images involved the posterior horns of the menisci, the sites of most false-negative arthroscopic diagnoses. The predictive value of a negative MR image was almost 100%. Even in patients with moderate-to-large effusions, the menisci were accurately evaluated. The results imply that MR imaging is useful in the preoperative evaluation of suspected meniscal tears.

Adolescent↗
PubMed1986

McArdle's disease heterozygotes. Metabolic adaptation assessed using 31P-nuclear magnetic resonance.

Two daughters of a propositus with documented McArdle's disease were shown by enzyme assay, gel electrophoresis, and immunoblotting to be partially deficient in skeletal muscle phosphorylase and, presumably, heterozygous for the trait. Both exhibited only the adult form of the skeletal muscle isozyme. By 31P-nuclear magnetic resonance, both heterozygotes showed a greater production of acid during fully aerobic exercise than when blood flow was occluded in ischemic exercise. This pattern is in contrast to that of control subjects, where there is significantly greater acid production in ischemic versus aerobic exercise, and distinct from that of phosphorylase-negative patients in which no acid is produced in either circumstance. We suggest that these heterozygotes may have adapted to their diminished phosphorylase by enhancing utilization of plasma glucose. If so, this mechanism could account for the observation that most of the symptoms of McArdle's disease are often manifest only in adulthood. These studies also show that although there are very high concentrations of phosphorylase in skeletal muscle (approximately 2% of the soluble protein), such a high level is essential for normal muscle glycogenolysis.

Adult↗
PubMed1986

A positioning seat for the neonate and infant with high tone.

Positioning and seating are important for premature and young infants with tonal problems. Positioning with pillows and sandbags, the use of special handling techniques (Bobath's neural developmental treatment), as well as other specialized approaches, have not proved satisfactory in reducing tone or spasticity in these infants. We developed an adaptive seat designed to reduce extensor tone through proper positioning. This seat has also been helpful in diminishing agitation. Without these benefits, infants are often immobilized in extension and cannot actively explore their environments. Diminution in agitation has also been important in increasing interaction with nurses.

Female↗
PubMed1986

Human parvovirus B19-induced epidemic acute red cell aplasia in patients with hereditary hemolytic anemia.

From March to August 1984, 26 patients with hereditary hemolytic anemia in northeastern Ohio developed acute, profound red cell aplasia. The patients included 14 males and 12 females 2 to 23 years old, with sickle cell anemia (20 cases), hemoglobin SC-disease (4 cases), sickle-beta-thalassemia (1 case), or hereditary spherocytosis (1 case). All had an acute onset of severe reticulocytopenia and anemia and prodromal symptoms of illness including fever, abdominal symptoms, headache, and arthralgias. Twenty-two received transfusions. Reticulocytosis occurred spontaneously within 2 to 14 days of presentation. In five acute-phase sera, 10(8) to 10(12) viral particles/mL were detected by electron microscopy. Human parvovirus B19 DNA was demonstrated in high concentration by hybridization in the same five acute-phase sera and in low concentration in sera of eight additional patients. The five highly viremic sera inhibited erythroid colony formation in vitro. B19-specific IgM was detected in sera of 24/26 patients, and B19-specific IgG in 21 of 22 patients tested. Our results indicate that human parvovirus B19 was the etiologic agent in this large epidemic of life-threatening acute red cell aplasia in patients with hereditary hemolytic anemia.

Adolescent↗
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

Roaring in Clydesdales.

An endoscopic survey was performed to assess arytenoid cartilage movement during quiet respiration in 48 Clydesdale horses. Physical characteristics which could influence the length of the recurrent laryngeal nerves were also recorded from these horses and the relationship of these characteristics to the presence of abnormal left arytenoid cartilage movements was assessed statistically. Some degree of abnormal arytenoid movement was observed in 50% of the animals over one year of age. No significant correlation between sex, age, estimated weight, height, or neck length could be found although affected animals were, on average, slightly taller, lighter and longer necked.

Journal Article↗
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↗
PubMed1985

Detection of Norwalk virus antibodies and antigen with a biotin-avidin immunoassay.

Biotin-avidin immunoassays (BAIs) were developed to detect Norwalk virus antigen and to measure Norwalk virus antibody. The BAI detected Norwalk virus infections by a fourfold titer rise in antibody in sera or by antigen in stool, with a sensitivity similar to or greater than that of the radioimmunoassay (RIA), and the BAI appeared to be more sensitive than the RIA for detecting antibody in single serum specimens. The BAI antigen test detected Norwalk antigen in all stools that were positive by the RIA, and in two stools negative by the RIA. Of 106 serum pairs tested by both the RIA and BAI, 94 demonstrated seroconversion, or lack of seroconversion, in both assays; 12 gave discordant results. Titers by the BAI generally exceeded those by the RIA by two- or fourfold. The BAI had advantages over the RIA in that it had added sensitivity in the detection of Norwalk antibody, was less time consuming, did not require frequent labeling of antibody, and did not have the problems associated with the use of isotopes.

Antibodies, Viral↗
PubMed1985

Microneutralization test for respiratory syncytial virus based on an enzyme immunoassay.

Virus infectivity and antibody neutralization titers for respiratory syncytial virus were determined in cell cultures in microtiter plates. After an appropriate incubation period, the cells were fixed, and an enzyme-linked immunosorbent assay was performed directly in the microtiter plates for detection of virus. Results could be read and recorded automatically, which is especially helpful when running large numbers of tests.

Antibodies, Monoclonal↗
PubMed1984

Spectrophotometric quantitation of peroxidase-stained protein bands following gel electrophoresis and the western blot transfer technique with respiratory syncytial virus.

A procedure is described for spectrophotometrically measuring the position and intensity of ELISA-stained protein bands after western blot analyses. Partially purified virus proteins separated by acrylamide gel electrophoresis and electrophoretically transblotted onto nitrocellulose paper were identified by ELISA reactions according to established procedures. The nitrocellulose paper strips were then rendered transparent on glass slides by treatment with a plastics solvent (Gelman Sepra-Clear). The slides were then scanned at 480 nm to obtain the precise migration distance and area under the curve (i.e., quantity) of each band, thus allowing accurate comparison of the proteins from different virus strains.

Electrophoresis, Polyacrylamide Gel↗
PubMed1984

Use of the biotin-avidin system to study the specificity of antibodies against respiratory syncytial virus.

To characterize the specificity of monoclonal antibodies against respiratory syncytial virus, we developed a technique which combined the biotin-avidin system, immunoprecipitation, and transblot electrophoresis. The viral proteins were first biotinylated and then immunoprecipitated with a monoclonal antibody or respiratory syncytial virus immune serum, separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and electrophoretically transferred to nitrocellulose paper. The protein bands were located on the paper with avidin-peroxidase plus a precipitable substrate. This procedure gave reproducible results qualitatively similar to those obtained by radioimmunoprecipitation but without the cost, risk of radiation exposure, or disposal problems of radioisotopes. This procedure should have widespread applications.

Antibodies, Monoclonal↗