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Biomedical subjects

D W Ziegler

Publications and source records attributed to D W Ziegler.

32 records · Page 2Linked to original sources
PubMed1976

Cytomegalovirus specific IgM and IgG response in humans studied by radioimmunoassay.

An indirect solid phase micro-radioimmunoassay (RIA) was adapted for the measurement of anti-cytomegalovirus class-specific immunoglobulin M (IgM) and immunoglobulin G (IgG). Cytomegalovirus (CMV) antigen (Ag) was added to the wells of microtiter plates and desiccated onto the bottom surface of the wells. Serial dilution of human CMV antisera were added and allowed to react with the Ag. The amount of viral antibody (Ab) was determined by measuring the specific binding of 125I-labeled goat anti-human IgG (125I-AHIgG) and/or IgM (125I-AHIgM). The multiple factors which influence the test were determined. Serial samples of sera from CMV-positive patients showed progressive increases in Ab titers on the basis of specific binding of 125I-AHIgG. The titers of IgM class anti-CMV Ab were also determined with the same sera, and enhancement of the titers was demonstrated when the incubation periods of the first Ag-Ab reaction were extended from 1 to 3 hr. The competition between the different Ig classes of Ab for CMV Ag and the involvement of rheumatoid factor (RF) were investigated. The anti-CMV IgG that may compete with the IgM determination was removed by adsorption of sera with Staphylococcus aureus (Cowan 1). The RF that would cause false anti-CMV IgM results was adsorbed with glutaraldehyde-insolubilized IgG. Our results indicate that this RIA is a practical, specific, and reproducible technique for detection of specific IgG and IgM Ab to CMV.

Antigens, Viral↗
PubMed1975

Detection by radioimmunoassay of antibodies in human smallpox patients and vaccinees.

A radioimmunoassay procedure was developed for determining smallpox and vaccinia antibodies in human sera. The test detected and measured both primary and secondary immune responses in persons infected with variola virus or vaccinia virus. The antibody titers obtained by complement fixation, hemagglutination inhibition, plaque reduction neutralization, and radioimmunoassay methods were compared. In sequential serum specimens, the radioimmunoassay test indicated fourfold or greater increases in all of the smallpox patients and in six of eight vaccinated persons. Both the complement fixation and the hemagglutination inhibition tests were less effective. In persons who had been vaccinated, radioimmunoassay and plaque reduction neutralization tests appeared to measure the same immune response. However, in smallpox patients the immune response was readily detected by radioimmunoassay, whereas an immune response was not detected by the plaque reduction neutralization test when vaccinia virus was the antigen in the test system. Radioimmunoassay is an operationally simple procedure which provides objective and quantitative end-point titers in serological determinations.

Antibodies, Viral↗
PubMed1975

Radioimmunoassay for detection of antibodies to Epstein-Barr virus in human infectious mononucleosis serum specimens.

A rapid microradioimmunoassay (RIA) technique was adapted for quantitatively measuring antibody titers to antigens occurring in Epstein-Barr virus (EBV)-infected lymphoid cells. In these experiments two EBV-infected cell lines, HR1K and EB-3, were used as antigen-positive cells and Molt-4 was used as the negative control cells. The antibody titers of sera from suspected infectious mononucleosis patients were compared by RIA and indirect fluorescent antibody (IFA) methods. As determined by each of the methods, 14 of 19 sera had positive antibody titers and the remainder of the sera had negative antibody titers. Thus, the two methods agreed completely in differentiating sera with antibodies to EBV antigens. To further evaluate the antibody specificity of the RIA, the antibody titers of paired sera, pre- or early infection and postinfection, from five confirmed infectious mononucleosis patients were determined by RIA and IFA. Seroconversion was demonstrated by both RIA and IFA for each of the patients. Thus, the sensitivity and specificity of the two procedures are about the same.

Antibodies, Viral↗
PubMed1974

Interactions of standard antibody with Australia antigens in Au Ag-Ab radioimmunoassay.

Human antisera against Australia (Au) antigen have been characterized by liquid-phase radioimmunoassay (RIA) for their precipitation of (125)I-labeled Au antigen. The end-point dilutions of sera (anti-Au) which precipitated 50% of (125)I-Au antigen by RIA correlated well with complement fixation titers but had a much wider range, indicating a greater precision and perhaps a better sensitivity of assay. Anti-Au serum diluted to precipitate 50% of (125)I-labeled Au antigen was used as standard antibody in RIA tests to detect either inhibition or enhancement of the reaction by preincubated mixtures of Au antigen and antibody specimens. Without free Au antigen or antibody in the resultant mixtures there was no inhibition or enhancement; the mixtures presumably contained immunoreactively equivalent proportions of Au antigen and antibody. RIA data for diagnostic specimens indicated an end-point sensitivity which was proportional to the dilution of the standard anti-Au sera used in the test. High concentrations of the standard antibody permitted detectable inhibition of (125)I-Au antigen precipitation at lower antigen specimen concentrations. Similarly, low concentrations of the standard antibody permitted detectable enhancement of (125)I-Au antigen precipitation at lower antibody specimen concentrations. Omitting the standard antibody altogether resulted in a more sensitive RIA for Au antibody in test sera.

Antibodies, Viral↗
PubMed1974

Criteria for preparing, evaluating, and standardizing iodinated globulins for radioimmunoassay procedures.

Procedures were examined for labeling immune globulins with radioactive iodine using chloramine-T as the oxidizing agent. The chloramine-T method was critically evaluated to establish the optimal conditions for preparing iodinated globulins with high specific radioactivities without impairing their immunospecificities for use in in vitro radioimmunoassays. The results showed that the use of 100 mug of chloramine-T per ml, 500 to 1,000 muCi of Na (125)I per mg of protein, and a 10-min oxidation reaction time produced globulins of both high specific radioactivities and immunospecificities. Criteria were established for evaluating and determining optimal concentrations of iodine-labeled globulin for use in radioimmunoassays. The results of this investigation indicated that the amount of labeled indicator globulin used in radioimmunoassays should be based upon protein concentration rather than radioactivity.

Animals↗
PubMed1972

Coupled-enzyme system for measuring viral neuraminidase activity.

A coupled-enzyme assay for determining viral neuraminidase activity is described. All reactants-viral neuraminidase, the initial substrate (fetuin), N-acetylneuraminic acid aldolase, lactic acid dehydrogenase, and reduced nicotinamide adenine dinucleotide-are combined in a single cuvette. Thus, in a single coupled system neuraminidase releases N-acetylneuraminic acid, which is cleaved to N-acetyl-D-mannosamine and pyruvic acid; finally, pyruvate is reduced to lactate as reduced nicotinamide adenine dinucleotide is oxidized. The rate of change of absorbance at 340 nm, as reduced nicotinamide adenine dinucleotide is oxidized, is a measure of the rate of reaction of the coupled system. This procedure, which measures the rate of release of N-acetylneuraminic acid by neuraminidase, is an alternate method for those procedures which require multistep, colorimetric determinations.

Alpha-Globulins↗
PubMed1972

Simplified radioimmunoassay for diagnostic serology.

A simplified, indirect radioimmunoassay is described for Escherichia coli, vaccinia virus, and herpesvirus. The antigens were affixed to glass cover slips; thus both the primary and secondary reactions take place on the cover slips, and the unbound antiserum is easily separated from the bound antiserum by rinsing. Rabbit or human immune sera were reacted with the antigens, and the primary immune complex was quantitated by a secondary reaction with (125)I-indicator globulin (anti-rabbit or anti-human). A direct relationship between the antiserum concentration and the (125)I absorption was established. Variations in titers were detectable, and the titers were comparable to complement fixation titers. Homologous and heterologous reactions were distinguishable. The method affords an objective, quantitative, and qualitative evaluation of antibody, and results are reproducible.

Absorption↗
PubMed1971

Nonspecific precipitation of serum proteins by sodium lauryl sulfate in agar diffusion and immunoelectrophoresis.

The anionic detergent sodium lauryl sulfate (SLS), in a final concentration of 0.1% and greater, reacted with whole serum in agar diffusion and immunoelectrophoresis to form artifactual precipitin lines. These lines occurred when either Ionagar or agarose was used as the supporting gel and were not affected by the presence of urea and 2-mercaptoethanol. Analytic chemical tests confirmed that the precipitating agent is SLS, and staining techniques showed that the detergent precipitates both protein and lipoprotein components of whole serum. Multiple artifactual precipitin lines occurred with a wide variety of animal sera, and a single line formed with human 7S immunoglobulin. Hence, in agar diffusion studies in which SLS is present in the test system, these artifactual lines may be easily misinterpreted as true antigen-antibody precipitin reactions.

Agar↗
PubMed1971

Induction of xanthine oxidase by virus infections in newborn mice.

In the liver tissue of newborn mice, xanthine oxidase activity is very low during the first 7 to 14 days of life. Infection of mice with several different viruses prematurely induced xanthine oxidase activity 2- to 10-fold in the liver tissue. Generally, overt signs of illness appeared after xanthine oxidase induction; however, some viruses induced the enzyme activity without causing morbidity or deaths. The elevated enzyme activity could not be correlated with alteration of either lactate dehydrogenase or glutamate-pyruvate transaminase. Likewise, there were no histological changes in the livers of infected animals when xanthine oxidase levels were abnormally elevated. These observations suggest that measurement of xanthine oxidase may be an effective method for the detection of subclinical or inapparent viral infections in either naturally infected newborn mice or in newborn mice inoculated with suspected virus-containing materials.

Journal Article↗
PubMed1969

Micro radiometric method for study of acid-insoluble materials in monolayer cell cultures.

A simple radiometric procedure for study of acid-insoluble products synthesized in monolayer cell cultures is described. Cell cultures were produced directly on the bottom surface of scintillation vials or on glass cover slips (8 X 30 mm). The cells were labeled and extracted; the radioactivity was determined while the cells remained affixed to the glass surface upon which they were grown. This procedure enabled rapid investigations of certain biosynthetic processes to be carried out by using many individual cell cultures. The method was applied to an investigation of (3)H-thymidine incorporation induced by vaccinia virus in a 5-bromodeoxyuridine-resistant cell line. (14)C-labeling was evaluated as an alternate procedure for cell quantitation.

Amino Acids↗
PubMed1969

Vaccinia neutralization test using a radioisotope assay for virus-induced enzyme activity.

Vaccinia virus induction of a metabolic activity in host cell cultures forms the basis of a new assay for neutralizing antibodies. A direct relationship between the amount of vaccinia virus infecting cell cultures and the induced incorporation of tritium-labeled thymidine into the acid-insoluble fraction of the cells provided an indicator system. A liquid scintillation spectrometer was used to determine radioactivity associated with cell materials, and it provided a method for partial automation of an immunological procedure. Reproducibility of the method was satisfactory, and agreement with conventional vaccinia serum neutralization tests was demonstrated.

Amino Acids↗
PubMedDate not supplied

Optimizing arthroscopic knots using braided or monofilament suture.

Surgeons need to know how the material properties of a suture affect the security of a surgical knot. The purpose of this study was to compare the security of some clinically important arthroscopic knots when tied using a braided multifilament suture and to draw comparisons with results of similar knots tied with monofilament suture. Permanent braided polyester suture was used to test 10 knot configurations. Eight of the knots included (1) two types of initial cinching knots followed by (2) one of four combinations of half-hitches. We also tested the taut-line hitch locked with half-hitches and the original Revo knot. Each knot was subjected to cyclic loading followed by an ultimate load to failure. Clinical failure was defined as the maximum force that resulted in 3 mm of loop displacement. Force versus displacement data were obtained, and the maximal loop holding capacities were compared statistically. The Duncan loop with switched-post half-hitches and the Revo knot (Linvatec, Largo, FL) showed the highest knot-holding capacities (mean, 87N and 92N, respectively) when compared with all other configurations (P < .0001) for braided suture. A similar knot-holding capacity was described for monofilament suture using the Duncan loop locked with switched-post, reversed-direction half-hitches (mean, 81 N). All knots without post switching slipped completely at significantly lower loads than knots with post switching (monofilament, P < .001; braided, P < .0001). When compared with results of knots tied with monofilament suture, the braided switched-post configurations had smaller cyclic displacements (braided, 0.7 mm; monofilament, 1.7 mm). Although the Revo knot showed good strength for braided suture, it was significantly weaker than other configurations when tied with monofilament suture. Therefore, it is important to test the knot strength for a given suture material before applying it clinically.

Arthroscopy↗
PubMedDate not supplied

Patient self-assessment of health status and function in glenohumeral degenerative joint disease.

One hundred three consecutive patients with primary glenohumeral degenerative joint disease completed standard questionnaires regarding their general health status (Short Form-36) and the function of their shoulder (Simple Shoulder Test). These patients' self-assessed health status indicated overall bodily pain, physical functioning, and physical role fulfillment scores that were significantly below those of population-based control groups. Self-assessed shoulder functions were likewise consistently below those of patients with normal shoulders. These deficits clearly indicated the problems that the patients desired to have resolved by treatment. The use of self-assessment questionnaires to routinely characterize patients with shoulder conditions is practical in the context of a busy practice. These data enable surgeons to understand the condition from the patient's perspective. This understanding should be central to the planning of treatment and to the evaluation of treatment effectiveness.

Female↗