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Biomedical subjects

D Dean

Publications and source records attributed to D Dean.

At least 37 records · Page 2Linked to original sources
PubMed1989

Use of a Chlamydia trachomatis DNA probe for detection of ocular chlamydiae.

We examined the efficacy of a Chlamydia trachomatis DNA probe in detecting ocular chlamydiae by comparing it with tissue culture isolation, direct fluorescent-antibody cytology, and clinical eye exams. In a trachoma-endemic area of Nepal, 430 Nepalese villagers were examined according to the World Health Organization trachoma grading scale. Upper tarsal conjunctival specimens from each subject were obtained for DNA probing, tissue culture, and fluorescent-antibody screening. Moderate to severe intensity of inflammation was found in 85 (21%) of 430 people studied. An additional 25 (7.2%) of 345 people with low or no intensity of inflammation also had microbiologically proven infection, which may reflect asymptomatic carriage. Compared with culture, the DNA probe had a sensitivity of 86.9% and a specificity of 91%. For direct fluorescent antibody versus culture, the values were 47.8 and 96.9%, respectively. Results from this study indicate that the DNA probe for C. trachomatis might be considered a valuable epidemiologic tool in screening trachoma-endemic populations for ocular chlamydiae.

Adolescent↗
PubMed1989

A method of uniform stratification of risk for evaluating the results of surgery in acquired adult heart disease.

The purpose of the study was to devise a method of stratifying open-heart operations into levels of predicted operative mortality, using objective data that are readily available in any hospital. Following univariate regression analysis of 3,500 consecutive operations, 14 risk factors were chosen that met these conditions. A few factors were excluded because they were insufficiently objective or not always available. An additive model was constructed, using the factors chosen, to calculate the probability of mortality within 30 days. The method was then tested prospectively in 1,332 open-heart procedures at the Newark Beth Israel Medical Center. Patients were categorized in five groups of increasing risk: good (0-4%), fair (5-9%), poor (10-14%), high (15-19%), and extremely high (greater than or equal to 20%). The correlation coefficient of anticipated and observed operative mortality, using the additive model, was 0.99. The operative mortality also correlated closely with complication rates and length of hospital stay. The additive model was compared with a second model based on logistic multiple regression; the resulting correlation coefficient was 0.85. The method was also tested at two other hospitals; although their sample sizes were smaller, the outcomes in each risk group were comparable with those at this institution. The collection of data proved to be acceptably simple for all three centers. This study demonstrates that it is possible to design a simple method of risk stratification of open-heart surgery patients that makes it feasible to analyze operative results by risk groups and to compare results in similar groups between institutions. Wider application of the system is recommended.

Adult↗
PubMed1988

Oxygen consumption and feeding rates of the sabellid polychaete, Myxicola infundibulum (Renier).

1. Rates of respiration and feeding were measured for the sabellid polychaete, Myxicola infundibulum. 2. Basal rates of respiration were 1.5 times lower than routine rates. 3. Clearance and irrigation rates were independent of cell type when the worms were fed on monocultures of algae; however, preferential selection was seen when the algal species were offered simultaneously. 4. Calculations indicate that this species can meet its energetic needs at rather low cell densities. 5. It is suggested that these low energy requirements, coupled with the capacity for high pumping/clearing rates may be of adaptive significance in reducing competition for food resources.

Animals↗
PubMed1987

Comparative organization of nitrogen fixation-specific genes from Azotobacter vinelandii and Klebsiella pneumoniae: DNA sequence of the nifUSV genes.

In the facultative anaerobe Klebsiella pneumoniae 17 nitrogen fixation-specific genes (nif genes) have been identified. Homologs to 12 of these genes have now been isolated from the aerobic diazotroph Azotobacter vinelandii. Comparative studies have indicated that these diverse microorganisms share striking similarities in the genetic organization of their nif genes and in the primary structure of their individual nif gene products. In this study the complete nucleotide sequence of the nifUSV gene clusters from both K. pneumoniae and A. vinelandii were determined. These genes are identically organized on their respective genomes, and the individual genes and their products exhibit a high degree of interspecies sequence homology.

Aerobiosis↗
PubMed1985

Aleurain: a barley thiol protease closely related to mammalian cathepsin H.

We have isolated and sequenced a 1400-base-pair cDNA derived from gibberellic acid-treated aleurone cell mRNA. This sequence contains an open reading frame that would code for a protein of 361 amino acids. The carboxyl-terminal two-thirds of the predicted amino acid sequence is closely related to that of the rat lysosomal thiol protease cathepsin H; the initial 143 amino acids may code for a secretory peptide plus a prosegment. The expression of this aleurone thiol protease mRNA is unusual in that, in aleurone cells, its abundance is regulated by the plant hormones gibberellic acid and abscisic acid, but it is also expressed at high levels in leaf and root tissue. This protease may represent the equivalent of a plant lysosomal thiol protease.

Amino Acid Sequence↗