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Biomedical subjects

D A Carlson

Publications and source records attributed to D A Carlson.

At least 55 records · Page 3Linked to original sources
PubMed1987

Susceptibility of Campylobacter jejuni and Yersinia enterocolitica to UV radiation.

Two enteric pathogens, Campylobacter jejuni and Yersinia enterocolitica serogroup O:3, together with Escherichia coli, were investigated for susceptibility to UV radiation at 254 nm. The UV dose required for a 3-log reduction (99.9% inactivation) of C. jejuni, Y. enterocolitica, and E. coli was 1.8, 2.7, and 5.0 mWs/cm2, respectively. Using E. coli as the basis for comparison, it appears that C. jejuni and Y. enterocolitica serogroup O:3 are more sensitive to UV than many of the pathogens associated with waterborne disease outbreaks and can be easily inactivated in most commercially available UV reactors. No association was found between the sensitivity of Y. enterocolitica to UV and the presence of a 40- to 50-megadalton virulence plasmid.

Campylobacter fetus↗
PubMed1986

Evaluation of the Sysmex CC-800. An automated eight-parameter hematology instrument.

An evaluation of the Sysmex CC-800 hematology analyzer (TOA Medical Electronics, Kobe, Japan, and distributed by American Scientific Products, Chicago, IL) was performed at University Hospital at Boston University Medical Center to assess the analytic performance and ease of use of the instrument. The Sysmex CC-800 is the first self-contained, fully automated, eight-parameter hematology analyzer. It can handle as many as 100 whole blood specimens without constant operator intervention. Stat and predilute modes are also available. The optional PDA-410 (particle distribution analyzer) was not evaluated in this study. Precision, linearity, carryover, and reproducibility of values over time in the automode were well within the manufacturer's specifications. The correlation study was performed with the existing Coulter S-Plus (Coulter Electronics, Hialeah, FL). The Sysmex CC-800 allowed us to expand the linear range without dilution for white blood cells to 160 X 10(3)/microL, hemoglobin to 26 g/dL, and platelets to 2,000 X 10(3)/microL. The samples on the automode exposed to normal laboratory atmosphere for up to 120 minutes showed no significant difference from baseline. The two instruments correlated well (r greater than 0.99). The authors concluded that the Sysmex CC-800 would be a reliable and time saving instrument in their laboratory.

Automation↗
PubMed1986

Evaluation of the Yellow IRIS. An automated method for urinalysis.

The authors evaluated the Yellow IRIS automated urinalysis instrument (International Remote Imaging Systems, Chatsworth, CA 91311) in terms of its analytic performance as well as its ease of use. The Yellow IRIS is a system using automated intelligence microscopy (AIM), coupled with a dipstick reader and specific gravity module. The instrument can handle up to 30 specimens per hour in the authors' setting as compared with 10 specimens per hour using a full manual urinalysis coupled with microscopic examination. The authors conclude that the Yellow IRIS performed better than the manual method in terms of precision, linearity, and throughput. In addition, the diagnostic yield using this system in terms of abnormal results was higher than would have been picked up by manual analysis alone.

Autoanalysis↗
PubMed1986

Hematology testing in the doctor's office laboratory.

Physicians are performing a greater variety of hematology tests in their offices. Changes in reimbursement by third-party payers have been one factor in this move. Manufacturers are now actively marketing new, smaller, and simpler desktop analyzers to meet this need. This article discusses the requirements for performing hematology tests and the available instrumentation for the doctor's office setting.

Bleeding Time↗
PubMed1982

Sex recognition pheromone in the tsetse fly Glossina pallidipes Austen.

Sexual responses of adult male G. pallidipes towards baited decoys show that a contact sex pheromone for this species is present in the hydrocarbon fraction of the adult female cuticle. Results are consistent with the view that the pheromone is a C35 compound and is present in sufficient quantity in newly emerged females to elicit maximum responses from males. Thus, maturation of sexual responsiveness is considered to be behavioral in females of this species.

Animals↗
PubMed1981

Identification of two West African black flies (Diptera: Simuliidae) of the Simulium damnosum species complex by analysis of cuticular paraffins.

Simulium damnosum is known to be a sibling species complex with at least 24 cytotaxonomically distinct forms in Africa. Of these, six occur in the area of West Africa covered by the World Health Organization Onchocerciasis Control Programme. They are all vectors of Onchocerca volvulus, and several are capable of migrating great distances. We report here a comparatively simple chemical method of species identification using individual adult females of pooled samples that have been collected and stored dry in glass vials. Females of two species, S. sirbanum and S. squamosum, were identified by extraction and analysis of cuticular components using gas chromatography. Statistically significant differences were seen between these two species for each of five sets of consistently appearing peaks that were quantitated and compared. The technique has considerable potential for use in the field since extracts or specimens may be stored indefinitely at ambient temperature before analysis.

Animals↗
PubMed1980

Identification of mosquitoes of Anopheles gambiae species complex A and B by analysis of cuticular components.

Two important vectors of malaria in Africa, Anopheles gambiae and Anopheles arabiensis (Diptera: Culicidae), often occur sympatrically and cannot be distinguished morphologically. A chemical method was developed to identify individual laboratory-reared adult males or females of either species by extraction and analysis of cuticular components with gas chromatography. Statistically significant differences were seen between species when selected pairs of peaks were compared.

Animals↗
PubMed1980

Sensitive gas-liquid chromatographic method for asulam residues in peaches.

The current analytical method for determining residues of the herbicide asulam (methyl (4-amino-benzenesulfonyl) carbamate) is the nonspecific colorimetric procedure based on the coupling reaction of N-1-naphthylethylenediamine with the diazotized amine. A new analytical method for determining the residues of this herbicide and its 2 known major metabolites, acetylasulam and sulfanilamide, in peaches has been developed and evaluated using gas chromatography with an N-P detector. The method is based on the hydrolytic conversion of the parent compound and the known metabolites to the common product sulfanilamide which is then analyzed by gas-liquid chromatography as its per N-methylated derivative. The identity of the derivative has been confirmed by chemical ionization mass spectrometry. The method was tested by using fortified crop extracts and also be analyzing crop treated by post-emergent application of the method is 5 ng and the detection limit in the crop is 0.1 ppm. Recoveries ranged from 70 to 80% from peaches at fortification levels of 1, 5, and 10 ppm. At a fortification level of 0.1 ppm the recovery is 50-60%.

Carbamates↗
PubMed1979

Differentiation between species of the Anopheles gambiae Giles complex (Diptera: Culicidae) by analysis of cuticular hydrocarbons.

Lipids were extracted from 500 female Anopheles gambiae and An. arabiensis in n-hexane and the extracts examined by gas chromatographic analysis using a glass column packed with 3% OV-1 on a 100-200 mesh Gas Chrom Q which was maintained at 225 degrees C. Cuticular hydrocarbons consisted mostly of unbranched paraffins. There were differences between the distribution of compounds with 25-29 carbons. After adjusting the C27 peak to 100%, hydrocarbons C26 and C29 represent heights of 80 and 69% in An. gambiae compared with values of 49 and 95 % in An. arabiensis. Other small but consistent differences were also found. Investigations are being performed on extracts from smaller samples and on other species within the An. gambiae complex.

Animals↗
PubMed1978

Sex pheromone of the tsetse fly: isolation, identification, and synthesis of contact aphrodisiacs.

Sex pheromones isolated from the cuticle of the female tsetse fly, Glossina morsitans morsitans Westwood, release mating behavior in the male fly at ultrashort range or upon contact with baited decoys. Three active components were identified as 15,19-dimethylheptatriacontane, 17,21-dimethylheptatriacontane, and 15,19,23-trimethylheptatriacontane. Chemical and biological comparisons show that the natural and synthetic compounds are identical.

Animals↗
PubMed1977

Dream mirrors.

The mirror is not so rare a dream element as has been thought; and its appearance may mark a critical point in an analysis. Intact mirrors with clear images are reported when the dreamer has made a creative integration of previously threatening material, while mirrors that are shattered or multiplied or without reflection are accompanied by evidence of terror and a lower level of psychological organization. Study of mirror dreams can further clarify the nature of the dream screen and the role of illusion in early interactions and development.

Adult↗