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L Hubbard

Publications and source records attributed to L Hubbard.

11 recordsLinked to original sources

Cloning, nucleotide sequence, and expression of the nitroreductase gene from Enterobacter cloacae.

The "classical" nitroreductases of enteric bacteria are flavoproteins which catalyze the reduction of a variety of nitroaromatic compounds to metabolites which are highly toxic, mutagenic, or carcinogenic. The gene for the nitroreductase Enterobacter cloacae has now been cloned using an antibody specific to this protein. The nucleotide sequence of the structural gene and flanking regions are reported. Sequence analysis indicates that this gene belongs to a gene family of flavoproteins which have not been previously described. Analysis of the 5'-untranslated region reveals the presence of putative regulatory elements which may be involved in the modulation of the expression of this enzyme. The cloned gene was placed under the control of a T7 promoter for overexpression of the protein in Escherichia coli. The expressed recombinant protein was purified to homogeneity and exhibited physical, spectral, and catalytic properties identical to the protein isolated from E. cloacae.

Amino Acid Sequence

Development of an acute pain service monitoring and evaluation system.

In 1990, Schumpert Medical Center, Shreveport, Louisiana--a 625-bed acute care hospital--established an acute pain service (APS) department and implemented the ten-step monitoring and evaluation process as recommended by the Joint Commission to facilitate the quality assurance program for pain management therapy. The program, which entails the cooperative effort of anesthesiologists and registered nurses, is intended to provide individualized pain management therapy to qualified APS patients on a 24-hour, seven-day-a-week basis. Through continuous, systematic monitoring and evaluation of six aspects of care and their indicators and thresholds, the quality of APS patient care can be determined and improved.

Academic Medical Centers

The Wisconsin age-related maculopathy grading system.

A new system for grading age-related maculopathy is described and measures of reliability are reported. A number of characteristics of age-related maculopathy are graded in a semiquantitative fashion from stereoscopic 30 degrees color fundus photographs, using a grid to define subfields, standard circles printed on plastic to assess size and area, and a specially designed lightbox to allow better discrimination of subtle drusen. The degree of exact agreement achieved between two trained graders across a variety of lesions ranged from 67.1% for drusen size to 99.6% for geographic atrophy. Kappa scores ranged from 0.55 (for drusen confluence) to 0.95 for geographic atrophy. This system will be useful in epidemiologic studies and clinical trials.

Aging

Detection of diabetic macular edema. Ophthalmoscopy versus photography--Early Treatment Diabetic Retinopathy Study Report Number 5. The ETDRS Research Group.

Clinical and photographic methods were used to assess retinopathy during the examinations of diabetic patients enrolled in the Early Treatment Diabetic Retinopathy Study (ETDRS). In analyzing available data from eyes randomly selected for deferral of treatment, the authors compare the clinical detection (including contact lens biomicroscopy) with photographic detection (30 degrees stereoscopic color fundus photographs) of diabetic macular edema. Based on clinical detection, 53% (1778 patients) had hard exudates within 1 disc diameter (DD) of the center of macula, 56% (1868 patients) had retinal thickening within this region, and 31% (1027 patients) had thickening at the center of macula. These analyses show agreements of 83, 78, and 83% between retinal specialists and photographic graders when assessing these three characteristics, respectively. Agreement was 81% in the detection of macular edema for which treatment is indicated (clinically significant macular edema). Each method has its advantages but in general there was close agreement between these methods, particularly for clinically significant macular edema, which supports the reliability of each method.

Diabetic Retinopathy

Urinary and hematologic indexes of hypohydration.

As part of a large-scale field feeding system test we were able to collect and study hundreds of aliquots of overnight urine samples obtained immediately prior to a fasting blood sample on days 1, 20, and 44 of the field test. The large number of experimental samples (greater than 650) and concomitant collection of blood and urine aliquots along with data on body weights gave us the opportunity to assess and quantitate the sensitivity of commonly used criteria of hypohydration. Urine aliquots for all test days were initially categorized by specific gravity (SG) greater than or equal to 1.03 (n = 124) or less than 1.03 (n = 540). Creatinine levels were elevated (P less than 0.001) in the concentrated urine samples, but a decreased trend in sodium-to-potassium ratios in these samples failed to achieve statistical significance (P greater than 0.05). However, when individuals with high SG urine were subclassified by a criterion of weight loss greater than 3% from original body weight, then creatinine concentrations were elevated (P = 0.05), whereas sodium-to-potassium ratios were decreased (P = 0.05) when subjects also with high SG but weight loss less than 3% were compared. Because of the moderate altitude (2,000 m) of the field site and the time of sojourn (44 days), there occurred a slight, but significant (P less than 0.001), erythropoietic response. Hematocrit and serum osmolality were not significantly different when examined by the criteria of high or low SG urine and weight loss greater than or less than 3% original body weight.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Urea Nitrogen

Men at the top.

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Nurses, Male