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D Dean

Publications and source records attributed to D Dean.

At least 127 records · Page 7Linked to original sources
PubMed1989

Time study.

Explore the source record for details and available documents.

Humans↗
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↗
PubMed1988

Long-term survival of patients with low ejection fraction: surgical versus medical management.

From May 1974 to December 1982, 3,592 patients underwent cardiac catheterization at the Buffalo Veterans' Administration Medical Center. Three hundred sixty-three patients (10.2%) presented with ejection fractions (EFs) < 40%. Of these, 194 had significant coronary artery disease. Follow-up data for retrospective analysis of survival rates were available for 173 of the 194 patients. Fifty-eight of these 173 had undergone coronary artery bypass surgery, while the remaining 115 had received medical treatment. The cumulative survival rates at 8 years for patients with EFs < 25% reveal a significantly better survival rate (61% vs. 29%, p <.03) for surgically treated patients. We conclude that coronary artery bypass surgery yields higher 8-year survival rates than does medical treatment for patients with compromised left ventricular function and significantly low EFs (< 25%).

Journal Article↗
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↗