Search PubMed⌕ Search

Biomedical subjects

N M Burdash

Publications and source records attributed to N M Burdash.

At least 37 records · Page 2Linked to original sources
PubMed1981

Group identification of streptococci. Evaluation of three rapid agglutination methods.

The clinical need to rapidly and correctly differentiate beta-hemolytic streptococci into Lancefield groups has prompted the commercialization of rapid agglutination methods. Three serogrouping kits, Phadebact, Sero STAT, and Streptex, were compared with the classic precipitin technic. One hundred and fifty beta-hemolytic streptococci and 75 alpha-hemolytic streptococci isolated from clinical specimens were used. Phadebact grouped all beta-hemolytic strains correctly while Sero STAT and Streptex were 96.7% and 99.3% accurate, respectively. Phadebact and Streptex correctly identified all group D streptococci. Commercial agglutination reagents represent a simple and reliable method for grouping streptococci.

Agglutination Tests↗
PubMed1981

Evaluation of an automated, computerized system (automicrobic system) for Enterobacteriaceae identification.

The automated and computerized AutoMicrobic system (AMS; Vitek Systems, Inc., subsidiary of McDonnell Douglas, Hazelwood, Mo.) was evaluated as a means of identifying the Enterobacteriaceae. The Micro-ID system (General Diagnostics, Morris Plains, N.J.) and, when necessary, conventional tubed media were used for comparison. Identification by AMS and Micro-ID differed in only 12 of 1,528 isolates (0.8%). Disagreements occurred primarily with Enterobacter spp. Precision testing of the AMS showed only 1 of 72 tests (1.4%) deviating from the expected. The AMS was found to be an accurate and precise method for the identification of Enterobacteriaceae.

Autoanalysis↗
PubMed1981

Effect of refrigeration on inoculated Micro-ID strips.

Since reading results after 4 h with the Micro-ID system is not always convenient, a study of 500 isolates indicated that identification at the species level is essentially unchanged when inoculated strips are refrigerated overnight and then incubated or incubated and then refrigerated overnight before reading.

Bacteriological Techniques↗
PubMed1980

A quantitative immunofluorescence test for the detection of anti-Candida antibodies.

A quantitative immunofluorescence assay for anti-Candida antibodies has been developed using a recently introduced system that includes an automatic fluorometer and a special immunoadsorbent for antigen coating. A commercially available cytoplasmic antigen preparation was adsorbed into the substrate, and after incubation with sera from patients with systemic candidiasis or from normal controls, the antibodies bound to the antigen-coated immunoadsorbent were revealed by the use of fluorescein-labeled antisera to human immunoglobulins. Using doubling dilutions of a high titer serum, a positive relation was found between antibody concentration and the logarithm of the intensity of fluorescence. Quantitative assays of unknown samples were performed using a calibration curve constructed from dilutions of that strongly positive sample; the results of antibody determinations were expressed as percentages of the control. Seven of 9 sera from patients with systemic candidiasis, and only 2 of 42 from asymptomatic individuals, had antibody levels considered significant in this assay. Precipitating antibodies were detected by counterimmunoelectrophoresis in all patients and in 18 of the asymptomatic controls; measurable antibody levels were also found in 14 controls showing no precipitating antibodies. This assay is simple, sensitive and inexpensive, and its quantitative nature makes it useful in the investigation of the immune response to C. albicans.

Antibodies, Fungal↗
PubMed1980

A comparison of four commercial systems for the identification of nonfermentative gram-negative bacilli.

Four commercial systems for the identification of glucose nonfermentative, gram-negative bacilli and the conventional system used in our laboratory were compared. The API 20E, Roche Oxi/Ferm Tube, BBL Minitek, Flow N/F System, and our system were compared for accuracy, time needed for identification and number of isolates needing additional testing. A total of 241 different isolates were used. The API 20E identified 86.7% correctly; Oxi/FermTube, 83.0%; Minitek, 93.4%; N/F System, 90.5%; and our system, 90.0%. Within 24 hours after isolation, the API 20E identified 25.7%; Oxi/Ferm Tube and Minitek, 0%; N/F System 27.3%; and our system, 35.7%. After 48 hours, the API 20E identified 74.7%; Oxi/Ferm Tube, 35.7%; Minitek, 45.2%; N/F System, 83.0%; and our system, 94.6%. The number of isolates that required additional testing for identification by the API 20E was 119; Oxi/Ferm Tube, 161; Minitek, 88; N/F System, 43; and our system, 36. Ease of performance, technologist time, and level of identification required by individual laboratories are discussed.

Bacteriological Techniques↗
PubMed1979

Immuno-heterogeneity of the calcitonins of hypercalcemia, breast and lung cancers and medullary carcinoma of thyroid.

Four antisera raised in the goat have very different properties: all recognized the immunoreactive calcitonin (iCT) of medullary carcinoma of the thyroid (MCT), one the response of normal subjects to induced or endogenous hypercalcemia and 2 others a different molecular species which occurs in half the patients with cancer of breast and 3/4 of patients with cancer of the lung. The latter two antisera are most sensitive to the 22-32 sequence of human calcitonin. Depending on the antiserum used, 4 or 7 peaks of immunoreactivity are found in eluates by column chromatography or stimulated serum from MCT. Not all elevated levels of iCT in serum are diagnostic of MCT and ectopic production by lung and breast cancer must be considered. Presence of higher levels of iCT with greater amounts of cancer tissue and undetectable levels after surgery or radiotherapy when using antisera which require intact molecule of calcitonin for recognition suggest the possibility that sequential calcitonin levels with differentiating antisera may be helpful in assessing the extent of disease and response to therapy.

Breast Neoplasms↗
PubMed1978

An identification scheme for gram-negative nonfermentative bacilli.

A series of six flow charts have been developed to identify the Gram-negative nonfermentative bacilli most commonly isolated from clinical specimens. Colonial morphology and oxidase reactivity determine the pathway to be followed on the flow chart which then indicates the specific test to be performed. Most isolates can be identified within 24 hours using 3 to 5 tests. Each pathway was selected on the basis of 94-100 per cent confidence limits otherwise an alternate pathway is shown. Results of 2,788 nonfermenters identified by this scheme are discussed.

Bacteria↗
PubMed1977

Simplified silver-plating stain for flagella.

Rhodes' silver-plating technique for staining flagella was tested for its reliability and convenience as a routine procedure in the clinical laboratory. Modifications were made in the stain preparation and the procedure of staining and were tested with smears of known motile gram-negative nonfermentative bacilli. The stain has proved to be accurate and reliable and can be easily utilized with a minimum of training.

Alcaligenes↗
PubMed1977

Bacterial gram staining by conventional and strip methods.

Conventional gram staining was compared with a method which uses dye impregnated paper strips for staining. The paper strip technique was judged accurate and reproducible and is recommended for use in the small laboratory and hospital ward.

Bacteriological Techniques↗
PubMed1976

Carcinoembryonic antigen and cystic fibrosis protein in blood from cystic fibrosis homozygotes and heterozygote carriers.

Carcinoembryonic antigen (CEA) activity was measured by radioimmunoassay in blood from cystic fibrosis (CF) homozygotes, heterozygote carriers of CF, normal healthy controls, and other patient controls with carcinomas involving gastrointestinal organs. All samples were also screened by electrofocusing for cystic fibrosis protein (CFP), a metabolic marker previously shown to be associated with the CF gene. Significantly increased levels of CEA activity were found in all CFP-positive groups; however, with one exception all patient controls with marked increases in CEA activity were CFP-negative. Immunodiffusion of perchloric acid extracts of CEA-like material from heterozygote carrier blood indicated that the CEA-like material, which was elevated in homozygotes and heterozygotes for CF, showed only partial identity with two separate CEA preparations obtained from colon carcinomas and was not identical to either A, B, or O(H) blood group substances. This glycoprotein material did, however, react with three different anti-CEA antisera. Our finding of an abnormally increased glycoprotein in cystic fibrosis, taken together with previous reports demonstrating abnormalities in the carbohydrate portion of glycoproteins found in various exocrine secretions in CF, further suggests that the primary defect in this disease is manifested partly as a defect in glycoprotein metabolism. This defect may result from an abnormality in one or more of the glycosyltransferases, possibly caused by a more primary defect in polyamine metabolism.

Adolescent↗
PubMed1976

Alpha-1-antitrypsin (Pi) types in Down's syndrome.

Alpha-1-antitrypsin (Pi) phenotypes have been determined in 40 patients suffering from Down's syndrome. Thirty-six of the patients were found to have a normal M phenotype, whereas two deficient phenotypes of the MS variety were observed. In addition, two M variants were noted. The significance of an M variant phenotype in some patients with Down's syndrome is not completely understood and is currently under investigation. Since the majority of the patients had a normal alpha-1-antitrypsin phenotype, the results of this study indicate that a deficiency in alpha-1-antitrypsin plays no role in the respiratory fragility of individuals with Down's syndrome.

Adolescent↗
PubMed1976

Evaluation of the acid-fast smear.

A retrospective analysis of the data involving all specimens submitted to the mycobacteriology laboratory over the past 20 months supports the continued use of the acid-fast smear as an aid in the detection of tuberculosis.

Diagnosis, Differential↗
PubMed1976

Automatic gram-staining with the microstainer II.

A comparison was made between the Microstainer II, an automatic staining machine, and the traditional, manual gram-staining method using clinical material and known organisms in a double blind study. Gram-reactions were in agreement with 98.4% of the organisms. The machine-stained microorganisms were generally found to be of the same or better quality than manually-stained organisms. Transfer of bacteria from slide to slide or smear to smear was not a significant problem. The Microstainer II would appear to be a useful addition to the large volume bacteriology laboratory.

Automation↗