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Biomedical subjects

R Young

Publications and source records attributed to R Young.

394 records · Page 22Linked to original sources

Vascular injury associated with naturally occurring strangulating obstructions of the equine large colon.

Ten horses were euthanatized before, during, or after surgery to correct severe volvulus of the large colon. At surgery, the colonic serosa changed from blue-gray, blue or purple toward a more normal pink in seven horses after the volvulus was corrected. The mucosa consistently remained black or dark red. Results of postmortem colonic microangiography revealed perfusion of the serosa and the circular and longitudinal muscle layers, but mucosal perfusion was limited by thrombosis in the muscularis mucosae and submucosa. There was evidence of thrombosis of the mesenteric colic vessels in six horses. Damage to the colonic vascular system, especially thromboembolism in the submucosa, may be an important limitation to colonic viability after surgical correction of volvulus of the large colon.

Angiography↗

Simultaneous pulmonary leiomyosarcoma and leiomyoma in pediatric HIV infection.

The case of a 7-year-old girl with acquired immunodeficiency syndrome treated for 5 years with AZT and intravenous gamma globulin is reported. Shortly before her demise she developed a pulmonary leiomyosarcoma and leiomyoma. Does prolonged survival in pediatric acquired immune deficiency syndrome increase the incidence of secondary malignancies?

Child↗

An evaluation of knowledge and skill retention following an in-house advanced life support course.

The aim of the study was to explore advanced life support (ALS) skills and knowledge retention, in 10 registered nurses, at 6 and 12 weeks following an in-house core ALS course. Data was collected by structured interview and structured observation at 6 and 12 weeks following the course. A sharp decline in the number of subjects attaining the 84% pass level at the 6 and 12 week interviews was noted. A modest increase in ALS theoretical knowledge and a decrease in practical skill performance between 6 and 12 weeks was identified. Implications for future practice and research are proposed.

Cardiopulmonary Resuscitation↗

IMRT (intensity modulated radiation therapy): progress in technology and reimbursement.

For a new treatment technology to become widely accepted in today's healthcare environment, the technology must not only be effective but also financially viable. Intensity modulated radiation therapy (IMRT), a technology that enables radiation oncologists to precisely target and attack cancerous tumors with higher doses of radiation using strategically positioned beams while minimizing collateral damage to healthy cells, now meets both criteria. With IMRT, radiation oncologists for the first time have obtained the ability to divide the treatment field covered by each beam angle into hundreds of segments as small as 2.5 mm by 5 mm. Using the adjustable leaves of an MLC to shape the beam and by controlling exposure times, physicians can deliver a different dose to each segment and therefore modulate dose intensity across the entire treatment field. Development of optimal IMRT plans using conventional manual treatment planning methods would take days. To be clinically practical, IMRT required the development of "inverse treatment planning" software. With this software, a radiation oncologist can prescribe the ideal radiation dose for a specific tumor as well as maximum dose limits for surrounding healthy tissue. These numbers are entered into the treatment planning program which then calculates the optimal delivery approach that will best fit the oncologist's requirements. The radiation oncologist then reviews and approves the proposed treatment plan before it is initiated. The most recent advance in IMRT technology offers a "dynamic" mode or "sliding window" technique. In this more rapid delivery method, the beam remains on while the leaves of the collimator continually re-shape and move the beam aperture over the planned treatment area. This creates a moving beam that saturates the tumor volume with the desired radiation dose while leaving the surrounding healthy tissue in a protective shadow created by the leaves of the collimator. In the dynamic mode, an IMRT treatment session generally can be initiated and completed within the traditional 15-minute appointment window for radiation oncology clinics. In addition to being comforting for the patient, this rapid treatment delivery mode satisfies a key financial issue for hospitals and clinics by giving them the ability to handle high patient loads and achieve a more rapid return on their investment in an IMRT system. New IMRT reimbursement codes have been issued under the pass-through provisions of Medicare's Outpatient Prospective Payment System (OPPS), which authorize special or increased reimbursement levels for promising new developments in healthcare technology that previous reimbursement procedures did not address. These pass-through payments are generally applicable for defined periods during a promising new technology's early stage of adoption. In the case of codes G0174 and G0178, the effective period has been left open-ended. While the CMS adoption of these new IMRT reimbursement codes certainly paves the economic road for the diffusion of this technology by flattening out some of the economic obstacles, there are still bumps to overcome. The most obvious one is the investment in hardware and software that may be required. However, the added demands on staff and the cost of training cannot be ignored. IMRT is a treatment process involving FDA-approved medical devices, offering the hope of improved treatment outcomes with fewer complications for patients and higher reimbursement rates for hospital providers. By the end of the year 2001, there will probably be more than 75 hospitals with IMRT capabilities in place.

Centers for Medicare and Medicaid Services, U.S.↗

Stability and purity profile of gonadorelin acetate: a high-purity gonadotropin-releasing hormone.

Recently, several reports of adverse reactions after pulsatile GnRH (gonadorelin hydrochloride) infusion therapy have appeared in the medical literature. Although the cause of these reactions has been associated with GnRH itself, the contributions of impurities and degradation products in the administered drug have not been determined, suggesting that the use of high-purity material may be advantageous in controlling unwanted side effects. This study evaluates the purity and long-term stability of a new GnRH product, gonadorelin acetate (Lutrepulse, Ortho Pharmaceutical Corporation). Both the purity and potency of the drug substance, the lyophilized product for injection, and the reconstituted material that would be transferred to the infusion pump system were monitored using high-performance liquid chromatography. The gonadorelin acetate drug substance was found to be stable for at least 12 months when stored at 24 degrees C in 50% relative humidity, and showed no degradation even under accelerated storage conditions. Similarly, the lyophilized product also showed excellent stability for at least 18 months when stored at 24 degrees C in 50% relative humidity. Upon reconstitution, gonadorelin acetate was found to be stable for at least 45 days when stored at 24 degrees C or 37 degrees C.

Chromatography, High Pressure Liquid↗

Continuous quality improvement in the classroom.

This article describes the use of continuous quality improvement (CQI) techniques, such as use of customer focus and the promotion of group interaction and problem solving, in an introductory nursing course. The use of CQI techniques resulted in satisfied students who met the course objectives.

Education, Nursing, Baccalaureate↗

Interlaboratory evaluation of an off-line supercritical fluid extraction/infrared spectrometric method for determination of petroleum hydrocarbons in solid matrixes.

A collaborative study was conducted, with 14 laboratories participating, to determine the method accuracy and precision of the proposed U.S. Environmental Protection Agency Methods 3560 and 8440. These methods involve the extraction of petroleum hydrocarbons from solid matrixes with supercritical carbon dioxide at 340 atm and 80 degrees C for 30 min (dynamic), collection of the extracted materials in tetrachloroethene (Method 3560), and analysis of the extracts by infrared (IR) spectrometry (Method 8440). The study design was based on the AOAC blind replicate design with balanced replicates. The study samples consisted of 4 solid matrixes that had petroleum hydrocarbon contents ranging from 614 to 32,600 mg/kg. Each of the 4 matrixes was extracted in triplicate, and the extracts were analyzed with 2 different IR spectrometers. In addition, each of the participating laboratories extracted a sample of unspiked clay soil, the same clay soil spiked with corn oil and reference oil at 1000 mg/kg each, and the same clay soil wetted to 30% water content and spiked with motor oil at 10,000 mg/kg (the latter 3 samples were extracted only once). Results indicated that the overall method accuracy for concentrations ranging from 614 to 32,600 mg/kg was 82.9%; the mean recoveries of petroleum hydrocarbons for each of the 4 solid matrixes ranged from 77.9 to 107% for analyses performed with the Perkin-Elmer Fourier transform IR spectrometer and from 75.9 to 101% for analyses performed with the Buck-Scientific IR spectrometer; the differences between the 2 instruments on a sample-by-sample basis were less than 17% for the total petroleum hydrocarbon determinations. The interlaboratory method precisions (RSDR) appeared to be matrix-dependent and ranged from 17.3 to 45.4% for analyses performed with the Perkin-Elmer Fourier transform IR spectrometer and from 16.7 to 47.9% for the Buck-Scientific IR spectrometer. The intralaboratory method precisions (RSDr) appeared to be less matrix-dependent and ranged from 11.5 to 17.0% for analyses performed with the Perkin-Elmer FTIR spectrometer and from 11.1 to 18.2% for the Buck-Scientific IR spectrometer. Method accuracy and precision data are also presented for the 5 laboratories that used Isco supercritical fluid extraction systems and for the 7 laboratories that used vessels with volumes of 3.5 mL or less with different supercritical fluid extraction systems.

Aluminum Silicates↗