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Biomedical subjects

E N Scott

Publications and source records attributed to E N Scott.

15 recordsLinked to original sources
PubMed1989

Immunoblot analysis of antibody responses to Sporothrix schenckii.

The serologic response to Sporothrix schenckii was investigated in patients with sporotrichosis by solid-phase enzyme-linked immunosorbent assays (ELISAs) and Western immunoblot techniques. A soluble antigen preparation derived from an S. schenckii isolate contained 15 protein staining components ranging in molecular size from 22 to 70 kilodaltons (kDa) by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Sera from 40 patients with sporotrichosis demonstrated Sporothrix immunoglobulin G antibody by ELISA with titers between 128 and 65,200. No sera from 300 healthy individuals or 100 patients with various systemic mycoses other than sporotrichosis had ELISA titers greater than 64. By Western immunoblotting of the antigens separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, sera from 10 patients with cutaneous sporotrichosis reacted with 8 to 10 antigen components (range, 40 to 70 kDa), while sera from 15 patients with extracutaneous sporotrichosis reacted with a greater number of antigen components (15 to 20 bands) over a wider range of molecular sizes (22 to 70 kDa). Antibody to 40- and 70-kDa antigen components was detected by immunoblots in all sera tested from patients with sporotrichosis. Antibody to 22- to 36-kDa antigen components was present in sera from 13 of 15 patients with extracutaneous sporotrichosis, but these lower-molecular-weight components were not detected by sera from patients with cutaneous sporotrichosis. Antibody to these components was not detected by Western blotting in sera from 19 of 20 patients with other fungal diseases or from 30 healthy individuals. Purification of these specific antigen fractions could provide the basis of a sensitive and specific serodiagnostic test to indicate the presence and activity of extracutaneous sporotrichosis.

Antibodies, Fungal↗
PubMed1987

Serologic studies in the diagnosis and management of meningitis due to Sporothrix schenckii.

Eight patients have previously been reported to have central nervous system infections caused by Sporothrix schenckii. In those patients the fungus proved quite difficult to culture, delaying correct diagnosis and treatment. We describe seven additional patients with sporotrichosis meningitis, all of whom had antibody to this fungus in cerebrospinal fluid and serum. The antibody in the cerebrospinal fluid was most likely produced locally, as evidenced by its oligoclonality and the relatively high ratio of immunoglobulin to albumin in the cerebrospinal fluid as compared with the serum. Only one of these seven patients, who had active sporotrichosis of the knee joint, had obvious extrameningeal infection. None of 130 patients with meningitis known to be caused by other agents and none of 170 patients with other neurologic disorders had antibody to S. schenckii in their cerebrospinal fluid. We suggest that cerebrospinal fluid should be tested for S. schenckii antibody (in addition to other fungal agents) in any patient with chronic meningitis for which no cause is discovered by the usual diagnostic tests.

Adult↗
PubMed1986

Activation of the alternative complement pathway by Sporothrix schenckii.

We studied the activation of complement by Sporothrix schenckii yeast cells. Total complement activity, and the effect of various activators on this activity, were assayed on aliquots of fresh nonimmune human serum with and without prior treatment with chelators. Both total hemolytic complement and C3 were consumed (activated) in serum chelated with magnesium ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, which blocks the classical pathway but leaves the alternative pathway intact. Further, C3 was consumed, but C4 (exclusively a component of the classical pathway) was preserved, in nonchelated serum after challenge by S. schenckii yeast cells. Absorption of serum with S. schenckii yeast cells to deplete antibodies did not alter these results. Furthermore, immunofluorescence studies demonstrated that C3, but not immunoglobulin G, was deposited on yeast cells during incubation with nonimmune serum. These data indicate that S. schenckii yeast cells activate the alternative complement pathway in vitro independently of antibody. These data do not define a role for the alternative pathway in in vivo host defenses against infection with this organism but provide a foundation for studies to evaluate such a role.

Chelating Agents↗
PubMed1983

Rapid preparation and purification of alkaline phosphatase and 125I-labeled antibody by minicolumn gel centrifugation chromatography.

Gel centrifugation chromatography was used for the preparation, purification and concentration of enzyme and 125I-labeled antibody. Low-molecular-weight reactants were rapidly and efficiently removed from either 125I-labeled antibody or enzyme-antibody conjugates by centrifugation of the reaction mixture through a minicolumn of Sephadex. Further purification of both radiolabeled and enzyme labeled antibodies were possible by the application and elution of each labeled antibody through a minicolumn of Protein A Sepharose. Minicolumns were constructed from readily available inexpensive components and allowed the rapid preparation and purification of antibody of high specific enzyme, and radioactivity. No difference between the 125I, or enzyme labeled antibody detection limit could be detected by a direct solid-phase immunoassay.

Alkaline Phosphatase↗
PubMed1983

Survival of human parainfluenza viruses in the South Polar environment.

The survival of human parainfluenza virus types 1, 2, and 3 was measured in both indoor and outdoor environments at South Pole Station, Antarctica, in an effort to determine the long-term survival of these viruses in this environment and to identify the possible source of respiratory tract illnesses which occurred in this isolated population in 1978 after 10 and 27 weeks of total social isolation. Viruses were applied to plastic petri plate surfaces which were then stored in indoor (21.4 degrees C; water vapor density, 1.50 g of water per m3) and outdoor environments (-22.4 to -33.2 degrees C; water vapor density, 0.706 and 0.247 g of water per m3). Parainfluenza virus type 1 at an initial titer of 3.75 log10 50% tissue culture infective doses per ml was inactivated after 4 days at room temperature and after 7 days outside. Parainfluenza virus type 2 and 3 at initial titers of 5.58 and 5.38 log10 50% tissue culture infective doses per ml were inactivated after 7 and 12 days, respectively, at room temperature and after 17 days of storage outside. Results indicate that the long-term survival of parainfluenza virus in either environment for up to 10 weeks is unlikely and probably did not provide the source of infectious virus responsible for the midisolation outbreaks of parainfluenza virus-related respiratory tract illnesses observed in this population during the 1978 winter season.

Antarctic Regions↗
PubMed1982

Cryptococcal capsular polysaccharide clearance in nonimmune mice.

Clearance of cryptococcal polysaccharide (CP) from tissues and body fluids of nonimmune mice was studied. Mice were injected intravenously only with one mg of purified CP, and serum, urine and tissues were obtained from each animal at various intervals for a period of 84 days. Tissue extracts, serum and urine were tested for CP content by enzyme-linked immunosorbent assay (ELISA) and latex agglutination. High concentrations of CP were detected by both assays one-half hour after injection in blood (serum), liver, spleen, kidney and lung (extracts). The duration of ELISA detectable CP was longest (70 days) in liver and spleen and shortest (14 days) in lung extract. By 14 days after injection, concentration of CP in the blood fell below that found in the liver and spleen. CP remained detectable (titers 32-64) after all other extracts became negative. These results indicate that CP is stored in tissues (binding mechanism and site unknown), and that the liver and spleen possess greater storage capacity than other tissues. Antibody (IgM) to CP appeared in low titer on the 14th day and thereafter.

Animals↗
PubMed1982

Rapid micromethod for preparation of enzyme-antibody conjugates.

A rapid method is described for labeling antibody with alkaline phosphatase by one-step glutaraldehyde linkage. The method involves the centrifugation of a small volume of an enzyme and antibody mixture through a minicolumn packed with hydrated Sephadex. This procedure rapidly removes ammonium sulfate and glutaraldehyde from the enzyme-antibody mixture and results in the efficient recovery of conjugated antibody without significant dilution.

Alkaline Phosphatase↗
PubMed1981

Persistent parainfluenza virus shedding during isolation at the South Pole.

Persistent parainfluenza virus shedding in healthy young adults occurred throughout the 8 1/2-month winter isolation period at Amundsen-Scott South Pole Station during 1978. Two episodes of respiratory illness were observed after 10 and 29 weeks of complete social isolation. Throat swabs collected both routinely, and during each outbreak of respiratory illness, were directly inoculated into cell cultures. Parainfluenza virus types 1 and 3 were recovered from both symptomatic and asymptomatic subjects throughout the winter. No other viruses were obtained by these efforts. The presence of parainfluenza virus in these subjects long after the accepted incubation period for viral upper respiratory illness, and when the introduction of new virus to this community was impossible, suggests its persistence in man.

Animals↗
PubMed1981

Enzyme-linked immunosorbent assays in murine cryptococcosis.

In this investigation, enzyme-linked immunosorbent assay (ElISA) procedures were used to study the time of appearance and the duration of demonstrable antigen and antibody in body fluids of mice with disseminated cryptococcosis. The ELISA antigen procedure detected cryptococcal capsular polysaccharide (CCP) in the serum and urine of infected mice 3 days after infection--4 days before it could be demonstrated by the latex agglutination procedure. ELISA-reactive antibody was present throughout the course of infection (mean death time, 32 days), whereas antibody was not detected by whole cell agglutination after day 20. High serum concentrations of CCP (titers to 64,000) persisted throughout the course of infection, while antibody declined to low levels with progression of disease. ELISA provides a sensitive system for quantitation and monitoring of antigen (CCP) processing and clearance (or storage), and for cryptococcal antibody formation in progressive cryptococcosis.

Agglutination Tests↗
PubMed1980

Development of an enzyme immunoassay for cryptococcal antibody.

An enzyme immunoassay (ELISA) for measurement of cryptococcal IgG antibody in human serum is described. Clinical studies indicate that the assay is a useful addition to the currently available techniques for measuring antibodies in cryptococcosis. IgG-specific antibody (titers 4 to 1,024) was detected in the serum of 78% of the cryptococcosis patients tested and in 61% of the serum from healthy individuals with positive delayed skin hypersensitivity to cryptococcin. The micro-ELISA for cryptococcal antibody is of potential value in patient management, and in epidemiological studies.

Animals↗
PubMed1980

Comparison of enzyme immunoassay and latex agglutination methods for detection of Cryptococcus neoformans antigen.

An enzyme immunoassay for the measurement of cryptococcal capsular polysaccharide in human body fluids is described. The enzyme immunoassay detects cryptococcal capsular polysaccharide at a concentration of 6 ng/ml, compared with 35 ng/ml detectable by the latex agglutination test. The enzyme immunoassay detects cryptococcal capsular polysaccharide in body-fluid specimens that are negative by the latex agglutination test. Titers by enzyme immunoassay are generally higher and persist longer into the treatment period than those determined by latex agglutination. No cryptococcal capsular polysaccharide is detected by the enzyme immunoassay procedure in fluids from subjects not known to have cryptococcosis. The enzyme immunoassay procedure presented here provides earlier detection of cryptococcal material in body fluids, and thereby diagnosis and treatment of cryptococcosis can be made earlier in the course of disease.

Antigens, Fungal↗
PubMed1980

Cryptococcus neoformans serotype groups encountered in Oklahoma.

Eighty clinical and 28 soil isolates of C. neoformans obtained in Oklahoma were separated into A-D and B-C serotype groups utilizing creatinine-dextrose agar with bromthymol blue. Previously, serotype B-C clinical isolates have been frequent only in patients from Southern California where as many as 50% of the isolates are of this type. In contrast, in patients from the rest of the United States the B-C frequency has been only 6%. Of the 80 C. neoformans isolates from Oklahoma patients, 12 (15%) were serotype B-C. One-half of these 12 Oklahoma patients with serotype B-C isolates had no history of any travel to California, and were long-time residents of Oklahoma. All 28 soil isolates of C. neformans from Oklahoma in this study were serotype A-D. Since serotype B-C recovery from a soil sample has never been reported, attempts are in progress to isolate serotype B-C from the environments of these patients from Oklahoma.

Adult↗
PubMed1978

Rapid presumptive identification of Cryptococcus neoformans.

Carbohydrate-containing extracts were prepared from mature yeast colonies grown on Sabouraud dextrose agar by mixing a 0.001-ml loopful of yeast cells for 30 s in phenolized saline and removing the cells by centrifugation. Extracts were prepared from 54 Cryptococcus neoformans isolates, 29 isolates of other Cryptococcus species, 16 isolates of Candida species, 2 Rhodotorula, 2 Torulopsis, and 1 Saccharomyces species. Initially the carbohydrate content of each extract was estimated (Molisch method) and adjusted to 1, 5, and 10 microgram/ml. Twofold dilutions of each extract were tested for reactivity with the cryptococcal latex agglutination reagent of Bloomfield et al. (N. Bloomfield, M.A. Gordon, and D.F. Elmendorf, Jr., Proc. Soc. Exp. Biol. Med. 114:64-67, 1963). All 54 C. neoformans extracts gave strong agglutinations (3+ to 4+) in dilutions of 1:4 or greater. None of the other yeasts produced any agglutination, except for 1 of 15 C. laurentii isolates, which showed a 1+ reaction that disappeared at a dilution of 1:4 and above. Subsequent testing established that a single extract made from 0.001 ml of yeast cells in 6 ml of phenolized saline contained less than 5 microgram of carbohydrate per ml, was suitable for a single rapid screening dilution, and eliminated any cross-reaction from the C. laurentii isolates. In our hands this method has provided a reliable differentiation of C. neoformans from other unknown yeast colonies in less than 20 min exclusive of a Molisch determination.

Candida↗