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Biomedical subjects

J Jagger

Publications and source records attributed to J Jagger.

At least 19 recordsLinked to original sources
PubMed2006

Ultrasound assessment of spleen size in collegiate athletes.

OBJECTIVES: To determine normal spleen dimensions in a healthy collegiate athletic population. METHODS: 631 Division I collegiate athletes from one university participated in the study. During pre-participation examinations, demographic data collected were collected from volunteer athletes including sex, race, measurement of height and weight, and age. Subjects also completed a medical history form to determine any history of mononucleosis infection, platelet disorder, sickle cell disease (or trait), thalassaemia, or recent viral symptoms. Subjects then underwent a limited abdominal ultrasound examination, where splenic length and width were recorded. RESULTS: Mean (SD) splenic length was 10.65 (1.55) cm and width, 5.16 (1.21) cm. Men had larger spleens than women (p<0.001). White subjects had larger spleens than African-American subjects (p<0.001). A previous history of infectious mononucleosis or the presence of recent cold symptoms had no significant affect on spleen size. In more than 7% of athletes, baseline spleen size met current criteria for splenomegaly. CONCLUSIONS: There is a wide range of normal spleen size among collegiate athletes. Average spleen size was larger in men and white athletes than in women and black athletes. A single ultrasound examination for determination of splenomegaly is of limited value in this population.

Adult↗
PubMed2001

Characterization of a high-gain harmonic-generation free-electron laser at saturation.

We report on an experimental investigation characterizing the output of a high-gain harmonic-generation (HGHG) free-electron laser (FEL) at saturation. A seed CO2 laser at a wavelength of 10.6 microm was used to generate amplified FEL output at 5.3 microm. Measurement of the frequency spectrum, pulse duration, and correlation length of the 5.3 microm output verified that the light is longitudinally coherent. Investigation of the electron energy distribution and output harmonic energies provides evidence for saturated HGHG FEL operation.

Journal Article↗
PubMed2001

Evaluating sharps safety devices: meeting OSHA's intent. Occupational Safety and Health Administration.

The Occupational Safety and Health Administration (OSHA) revised the Bloodborne Pathogen Standard and, on July 17, 2001, began enforcing the use of appropriate and effective sharps devices with engineered sharps-injury protection. OSHA requires employers to maintain a sharps-injury log that records, among other items, the type and brand of contaminated sharps device involved in each injury. Federal OSHA does not require needlestick injury rates to be calculated by brand or type of device. A sufficient sample size to show a valid comparison of safety devices, based on injury rates, is rarely feasible in a single facility outside of a formal research trial. Thus, calculations of injury rates should not be used by employers for product evaluations to compare the effectiveness of safety devices. This article provides examples of sample-size requirements for statistically valid comparisons, ranging from 100,000 to 4.5 million of each device, depending on study design, and expected reductions in needlestick injury rates.

Blood-Borne Pathogens↗
PubMed2000

High-gain harmonic-generation free-electron laser

A high-gain harmonic-generation free-electron laser is demonstrated. Our approach uses a laser-seeded free-electron laser to produce amplified, longitudinally coherent, Fourier transform-limited output at a harmonic of the seed laser. A seed carbon dioxide laser at a wavelength of 10.6 micrometers produced saturated, amplified free-electron laser output at the second-harmonic wavelength, 5.3 micrometers. The experiment verifies the theoretical foundation for the technique and prepares the way for the application of this technique in the vacuum ultraviolet region of the spectrum, with the ultimate goal of extending the approach to provide an intense, highly coherent source of hard x-rays.

Journal Article↗
PubMed2000

A comparison of biochemical and functional alterations of rat and human erythrocytes stored in CPDA-1 for 29 days: implications for animal models of transfusion.

Animal models of transfusion are employed in many research areas yet little is known about the storage-related changes occurring in the blood used in these studies. This study assessed storage-related changes in red blood cell (RBC) biochemistry, function and membrane deformability in rat and human packed RBCs when stored in CPDA-1 at 4 degrees C over a 4-week period. Human blood from five volunteers and five bags of rat RBC concentrates (five donor rats per bag) were collected and stored at 4 degrees C. RBC function was assessed by post-transfusion viability and the ability to regenerate adenosine triphosphate (ATP) and 2,3-diphosphoglycerate (DPG) when treated with a rejuvenation solution. Membrane deformability was determined by a micropipette aspiration technique. ATP in rat RBCs declined more rapidly than human RBCs; after 1 week rat ATP fell to the same level as human cells after 4 weeks of storage (rat, 2.2 +/- 0.2 micromol g(-1) Hb; human, 2.5 +/- 0.3 micromol g(-1) Hb). Baseline DPG concentrations were similar in rat and human RBCs (16.2 +/- 2.3 micromol g(-1) Hb and 13.7 +/- 2.4 micromol g(-1) Hb) and declined very rapidly in both species. Human RBCs fully regenerated ATP and DPG when treated with a rejuvenation solution after 4 weeks of storage. Rat RBCs regenerated ATP but not DPG. Post-transfusion viability in rat cells was 79%, 26% and 5% after 1, 2 and 4 weeks of storage, respectively. In rats, decreased membrane deformability became significant (- 54%) after 7 days. Human RBC deformability decreased significantly by 34% after 4 weeks of storage. The rejuvenation solution restored RBC deformability to control levels in both species. Our results indicate that rat RBCs stored for 1 week in CPDA-1 develop a storage lesion similar to that of human RBCs stored for 4 weeks and underscores significant species-specific differences in the structure and metabolism of these cells.

2,3-Diphosphoglycerate↗
PubMed2000

Safety in the OR.

Explore the source record for details and available documents.

Accidents, Occupational↗