PubMed Health⌕ Search

Biomedical subjects

T Ziegler

Publications and source records attributed to T Ziegler.

87 records · Page 5Linked to original sources
PubMed1988

Time-resolved fluoroimmunoassay compared with virus isolation for rapid detection of respiratory syncytial virus in nasopharyngeal aspirates.

Two monoclonal antibodies against two distinct conserved epitopes of the respiratory syncytial virus (RSV) nucleocapsid protein were used in a direct time-resolved fluoroimmunoassay (TR-FIA) for the detection of RSV antigens in nasopharyngeal aspirates. The capture antibody was adsorbed to the solid phase of microdilution strip wells, and the indicator antibody was labeled with a europium chelate. Specimens and label were incubated simultaneously for 1 h at 37 degrees C in the coated wells. After the test samples were washed, fluorescence enhancement solution was added, strips were shaken, and the time-resolved fluorescence was measured. The test procedure took only 75 min, and the total time for 20 specimens, with pretreatment by sonication, was 2 to 3 h. We prospectively evaluated the detection of RSV in nasopharyngeal aspirates of pediatric patients by TR-FIA and by virus isolation in human diploid fibroblasts. TR-FIA detected 40 of 42 isolation-positive specimens. Nine additional isolation-negative specimens were positive by TR-FIA; all proved to be true positives by a blocking-type confirmatory assay. The sensitivity, specificity, positive predictive value, and negative predictive value for TR-FIA were 95, 96, 82, and 99%, respectively, of the values obtained by virus isolation and 96, 100, 100, and 99%, respectively, of the values obtained by virus isolation and the confirmatory assay.

Adolescent↗
PubMed1987

Chronic glomerular microangiopathy complicating metastatic carcinoma.

Six cases of metastatic carcinoma associated with chronic glomerular microangiopathy and renal failure are reported. All had prominent subendothelial lucent zones and double-contoured glomerular basement membranes. There was no immunohistologic or ultrastructural evidence for immune complex entrapment in glomeruli. By immunohistology, material antigenically related to fibrin or fibrinogen was identified in glomerular basement membranes despite a paucity of typical fibrillar fibrin. Four patients received mitomycin C before the onset of renal disease, and one patient received chemotherapy other than mitomycin C before development of renal failure. One patient had no chemotherapy but was given radiotherapy, which did not include the kidneys in the irradiated field. These six cases emphasize the diverse pathophysiologic mechanisms by which glomerular microangiopathy may arise in metastatic carcinoma.

Adenocarcinoma↗
PubMed1985

Typing of herpes simplex virus isolates with monoclonal antibodies and by nucleic acid spot hybridization.

Fifty-one clinical isolates of herpes simplex virus (HSV) were typed by an enzyme immunoassay (EIA) using mouse monoclonal antibodies, by DNA spot hybridization, and by restriction enzyme analysis using restriction endonuclease Eco RI. Extracts of VERO cells infected with the isolates were used for coating microtitre plates or denatured and spotted onto nitrocellulose filters. Viral antigens passively adsorbed to microtitre plates were detected by an indirect EIA using mouse monoclonal antibodies specific for HSV type 1 (HSV-1) or HSV type 2 (HSV-2). Spotted DNA was hybridized with 32P-labeled probes containing Hind III/Sal I-fragments of either HSV-1 or HSV-2 DNA and bound radioactivity was detected by autoradiography and counted in a liquid scintillation counter. All the three methods gave identical results for the 51 isolates studied. Twenty-six isolates were identified as HSV-1 and 25 as HSV-2. An additional 30 specimens were tested only by EIA and hybridization. Results by both techniques were in complete agreement.

Animals↗
PubMed1985

Response of alkaline phosphatase to zinc repletion in hypozincemic hemodialysis patients.

The response of serum alkaline phosphatase (AP), a zinc-dependent metalloenzyme, to zinc administration via the dialysate (400 micrograms/l) was examined in 14 hypozincemic (less than 30th percentile of dialysis patients) hemodialysis patients and in 14 placebo-treated matched dialysis control patients. Plasma zinc and serum AP were measured three times: prior to, once weekly during (5 weeks), and 2 weeks after addition of zinc to the dialysate. The serum zinc levels remained stable in placebo-treated controls (initial 87.7 +/- 12.5; final 78.6 +/- 8.3 micrograms/dl) and increased in zinc-treated patients (initial 76.4 +/- 8.3; 5th week 96.9 +/- 13.3; 2 weeks after zinc withdrawal 82.3 +/- 12.2 micrograms/dl). There was a slight increase of AP with time in placebo controls (initial 90.2 +/- 26.5; 5th week 100 +/- 29 U/l) and a more pronounced increase in zinc-treated patients (initial 90.8 +/- 19.9; 5th week 113 +/- 20.9 U/l). The difference between the two groups was marginally significant (p less than 0.05; analysis of variance). It is concluded that zinc repletion via dialysate with documented increase of serum zinc levels in initially hypozincemic dialysis patients causes a reversible increase of serum AP. The result is compatible with some tissue zinc deficiency in hypozincemic dialysis patients.

Adult↗
PubMed1984

Detection of varicella-zoster viral antigens in clinical specimens by solid-phase enzyme immunoassay.

Forty-two vesicular specimens from patients with a clinical diagnosis of varicella-zoster virus (VZV) infection were tested in a four-layer solid-phase enzyme immunoassay (EIA) for VZV antigens. Guinea pig and rabbit immunoglobulins to purified VZV nucleocapsids and a commercially obtained conjugate were used as immunoreagents. Thirty-nine specimens were positive by EIA, and the results were verified by a confirmatory test with normal guinea pig immunoglobulins as a first layer. None of 20 specimens reacted in a similar EIA for herpes simplex virus (HSV) antigens. One of 60 specimens from which HSV had veen isolated gave a weak positive reaction in the VZV assay; no reaction was detected after further dilution of the specimen. Of 24 specimens from which VZV isolation was attempted, virus was isolated from eight, but 21 were shown to contain VZV antigen by EIA. Thus this EIA enables a rapid and specific diagnosis of VZV infections.

Antigens, Viral↗
PubMed1983

Solid-phase enzyme-immunoassay for the detection of herpes simplex virus antigens in clinical specimens.

An indirect solid-phase enzyme-immunoassay (EIA) for the detection of herpes simplex virus (HSV) antigens in clinical specimens was developed. Rabbits and guinea pigs were hyperimmunized with highly purified nucleocapsids of HSV type 1. Microtitre plates were coated with 0.25 microgram of guinea pig anti-herpes simplex type 1 immunoglobulins per well. Clinical specimens, diluted in phosphate buffered saline containing fetal calf serum and detergents, were sonicated and incubated in the test wells overnight at 37 degrees C. Rabbit anti-HSV immunoglobulins were added as a secondary antibody at a concentration of 3.2 micrograms per well, and peroxidase conjugated swine antibodies against rabbit immunoglobulins, diluted 1:1,000, were used as a fourth layer. Clinical specimens which were sent for virus isolation or for isolation of Chlamydia trachomatis were tested by the developed assay and 20 out of 27 isolation positive specimens were found positive by EIA. Five out of 67 specimens negative by isolation gave positive results by EIA. The specificity of the results was confirmed by a control test using wells coated with normal guinea pig immunoglobulins. The test detected antigens from both serotypes of HSV. Cross reactions with varicella-zoster- or with cytomegalovirus were not found, and antigens from uninfected cells did not result in false positive results.

Animals↗
PubMed1982

Determination of IgG- and IgM-class antibodies to mumps virus by solid-phase enzyme immunoassay.

An indirect enzyme immunoassay (EIA) for the determination of IgG and IgM antibodies to mumps virus is described. Viral antigens and control antigens were adsorbed onto polystyrene microtiter plates, and antibodies attached to the antigens were detected by subsequent binding of commercial peroxidase-labeled antibodies to the heavy chains of human IgG and IgM immunoglobulins. A comparison of antibody titers obtained by the EIA and by indirect immunofluorescence test showed a close concordance between these two tests, with EIA, however, being more sensitive. Occasional cross-reactions between mumps and parainfluenza antibodies were detected in the IgG antibody test but not in the IgM antibody test. In sera from 84 patients with mumps infection, all cases were diagnosed by the EIA IgM antibody assay, 96% from the first serum specimen. Mumps was diagnosed by complement fixation (CF) in 71% of these cases: unclear or erroneous results with parainfluenza titer increases in 10% and no diagnosis in 18% of the cases. The EIA IgM antibody assay was thus better than the CF test for the diagnosis of acute mumps infection.

Adolescent↗
PubMed1980

Solid-phase enzyme immunoassay for determination of antibodies to cytomegalovirus.

A solid-phase enzyme immunoassay for the determination of immunoglobulin H (IgG) and IgM antibodies to cytomegalovirus is described. The enzyme immunoassay gave reliable and consistent results which were in concordance with those obtained by the complement fixation test and the indirect immunofluorescence test. Antibodies to herpes simplex and varicella-zoster viruses did not interfere in the enzyme immunoassay for cytomegalovirus IgM antibodies. In a few patients with IgM antibodies to Epstein-Barr virus, cytomegalovirus IgM antibodies were also detected. False-positive cytomegalovirus IgM antibody results were observed in sera containing both the rheumatoid factor and cytomegalovirus IgG antibodies. This rheumatoid factor interference was overcome by the absorption of sera with polymerized human gamma globulin. The absorption did not affect true cytomegalovirus IgM antibody titers. Also described is a simple enzyme immunoassay that makes possible a more sensitive detection of the rheumatoid factor than the latex agglutination test.

Antibodies, Viral↗
PubMed1979

Hypertension with mineralocorticoid administration to the Long-Evans rat.

1. The Carworth Long-Evans rat has been reported to develop adrenal-regeneration hypertension but not deoxycorticosterone acetate (DOCA) hypertension. Deficiency of a hypothalamic receptor for deoxycorticosterone which mediates saline polydipsia has been postulated to underlie this resistance. Since a mineralocorticoid etiology for adrenal-regeneration hypertension has been postulated and all mineralocorticoids are thought to act on common receptors, these previous reports are difficult to reconcile. 2. To determine if an absolute or relative resistance to mineralocorticoids is present, Charles River Long-Evans and Sprague-Dawley rats were given 40 mg (107 micromol) of DOCA pellets/rat or 250 microgrms (0.65 micromol) of 2 alpha-methyl-9-alpha-fluorocortisol/day subcutaneously. 3. Saline polydipsia occurred with both steroids with both rat strains, though significantly less with the Long-Evans rats. Both types of rats became hypertensive and developed cardiac and renal enlargement with both steroids. Hypertension developed more rapidly with 2 alpha-methyl-9 alpha-fluorocortisol. 4. Thus mineralocorticoid hypertension can be produced in the Charles River Long-Evans rat, and the development of adrenal-regeneration hypertension in this rat strain is not incompatible with a mineralocorticoid etiology for adrenal-regeneration hypertension.

Adrenalectomy↗
PubMedDate not supplied

Interactions between aldehyde derivatives and the aldehyde binding site of bacterial luciferase.

The interaction of triazine aldehydes with the aldehyde binding site of bacterial luciferases was investigated using a series of triazine aldehydes with different aldehyde chain length, and substituents on the s-triazine ring. Substrate activity was determined using luciferase from Photobacterium fischeri and Vibrio harveyi in a dithionite-based luciferases assay. The chain length optimum was determined for two triazine aldehyde classes to be C-10 and C-11, respectively. Only the substrate activity of 10-(4-chloro-6-methylthio-s-triazine-2-yl)aminodecanal (5) was as high as n-decanal, the reference aldehyde. All other triazine derivatives reduced light emission, probably by hindered binding of the substrates. The degree of activity reduction correlated with the volume of the triazine ring moiety. The triazine moiety volume of compound 5 was estimated to be 200 x 10(-30) m3. Triazine aldehydes which showed reduced light emission had an estimated volume of 228 x 10(-30) m3 or greater. All triazine aldehydes showed approximately 10-fold lower activities for Vibrio harveyi than for Photobacterium fischeri luciferase. Substrate specificity was the same for both luciferases. A schematic superposition of quinone aldehydes and triazine aldehydes which showed substrate activities equivalent to n-decanal, indicated potential interaction sites of aldehyde substrates with the aldehyde binding site of bacterial luciferases. The in vivo relevance of the results is discussed.

Aldehydes↗
PubMedDate not supplied

An endothelial cell-smooth muscle cell co-culture model for use in the investigation of flow effects on vascular biology.

Flow and the associated shear stress have been shown to play an active role in the regulation of the structure and function of endothelial cells (EC) in vitro. Although cultured EC subjected to flow exhibit an elongated morphology and a decreased cell growth rate rather like those observed in vivo, there are differences in morphology and growth rate, as well as other characteristics, between in vitro and in vivo EC. This suggests that flow is only one of the many factors affecting EC differentiation in vivo. In this study, a co-culture model system was designed, which includes smooth muscle cells (SMC), a matrix of collagen type I, and a confluent monolayer of EC, and this simplified model of the arterial wall was subjected to a steady, laminar shear stress of 10 and 30 dyn/cm2. Under non-flow conditions, EC exhibited an elongated shape, but with a random orientation. In response to flow, there was an alignment with the direction of flow. This alignment occurred more rapidly at 30 dyn/cm2 than at 10 dyn/cm2. The collagen matrix was found to be primordial in the maintenance of a quiescent endothelium, even in the absence of SMC and flow, suggesting the importance of an organized extracellular matrix (ECM) in the differentiation of cells in vivo.

Animals↗
PubMedDate not supplied

A working in-house computer system for a general ophthalmology practice.

The authors describe their computer system, which was designed to support all of the information needs of their office and utilize the capabilities of the computer in every aspect of the practice. The system is now intricately involved in both clerical and medical activities. Problems of implementation were alleviated by the participation of the physicians and staff in designing the portions of the system with which they would be working; thus, the system is tailored to fit the needs of each individual.

Computers↗
PubMedDate not supplied

Time-resolved detection of singlet oxygen luminescence in red-cell ghost suspensions: concerning a signal component that can be attributed to 1O2 luminescence from the inside of a native membrane.

For about ten years, it has been debated whether in principle it is possible to detect 1O2 located within the cell membrane by performing experiments with cell suspensions or even in tissue. In this paper we present our investigations on photosensitized red-cell ghost suspensions (RCGSs) and our strategy for the detection of luminescence of singlet oxygen (1O2) from the inside of the cell membrane. Using a very sensitive apparatus for time-resolved 1O2 detection, a very promising sensitizer and an adequate experimental strategy, a very small amount of the detected luminescence indeed can be attributed to 1O2 from the inside of the ghost membrane.

Erythrocyte Membrane↗