Biomedical subjects
W K Metcalf
Publications and source records attributed to W K Metcalf.
Reliability of quantitative muscle testing in healthy children and in children with Duchenne muscular dystrophy using a hand-held dynamometer.
The purpose of this study was to examine intratester and test-retest reliability using a hand-held dynamometer for the measurement of isometric muscle strength in 28 healthy children and children with Duchenne muscular dystrophy. The Dystrophic Group consisted of 14 children diagnosed with Duchenne muscular dystrophy, and the Healthy Group consisted of 14 age-matched children with no history of orthopedic or neuromuscular disorders. One physical therapist tested hip and knee extension, elbow flexion, and shoulder abduction in each child bilaterally. A two-way analysis of variance for repeated measures was used to analyze differences between measurements taken within and across the testing sessions. Pearson product-moment correlation coefficients were determined on mean values across the testing sessions for each variable. No significant differences (p greater than .05) between measurements taken within or across testing sessions were found in either the Dystrophic Group or the Healthy Group. Correlation coefficients for the Dystrophic Group ranged from .83 to .99 for the variables tested. Correlation coefficients for the Healthy Group ranged from .74 to .99. The results suggest that the hand-held dynamometer can be used as a reliable instrument in measuring the isometric strength of selected muscles in children.
The kinetic differences between sodium nitrite, amyl nitrite and nitroglycerin oxidation of hemoglobin.
The effect of sodium nitrite, amyl nitrite and nitroglycerin (glyceryl trinitrate) on the hemoglobin of adult erythrocytes was examined in vitro. Both amyl nitrite and nitroglycerin reacted immediately with oxyhemoglobin to effect oxidation into methemoglobin while sodium nitrite required an inductionary period (lag phase) prior to the reaction. Kinetic studies of the biomolecular rate law for each of the preceding reaction's reactionary periods (log phases) allowed rate constant calculations to be made. The values are 1.14 x 10(4) M-1 min-1, 7.45 x 10(4) M-1 min-1, and 3.50 x 10(1) M-1 min-1 for sodium nitrite, amyl nitrite and nitroglycerin, respectively. A comparison of the amyl nitrite and nitroglycerin rate constants reveals that amyl nitrite is approximately 2000-fold more toxic to oxyhemoglobin than nitroglycerin. These oxidant's effect on in vitro hemoglobin solutions are comparable since both reactions approximate to rectangular hyperbolae. Sodium nitrite reacts about 300-fold faster with oxyhemoglobin than does nitroglycerin. However, the sodium nitrite reaction proceeds in a sigmoidal fashion which makes a strict comparison between these compounds relative toxicities less clear cut.
Kinetics of amyl nitrite-induced hemoglobin oxidation in cord and adult blood.
The effect of amyl nitrite on the erythrocytes of adult and cord hemoglobin was examined in vitro. This study revealed that amyl nitrite caused oxyhemoglobin to become oxidized to methemoglobin wherein a rectangular hyperbolic curve was generated as the reaction progressed. This curve consisted of a reactionary log phase, and a terminal asymptotic phase only, with no inductionary lag phase. A comparative study of human cord blood oxidation times and adult blood was undertaken. It was revealed that cord blood erythrocytes were oxidized by amyl nitrite at a 5-6-fold greater rate than adult blood erythrocytes. Based on an independent Student's t-test, the time taken for cord blood erythrocytes to undergo oxidation was significantly shorter (P less than 0.05) than adult controls. This greatly enhanced reactivity of cord blood erythrocytes parallels earlier findings when sodium nitrite was used instead of amyl nitrite. However, this difference defies a simple explanation and must be attributed to many factors which may include pH, structural differences, and solubility phenomenon.
Lymphocyte fluorescent profiles (LFP): a possible screening technique in neoplasia.
A technique involving fluorescent protein staining and microfluorometry has been developed for measuring the lymphocyte fluorescent profile (LFP) of peripheral blood lymphocytes. In contrast to normal humans who display a regular bell-shaped curve, the profile from patients with cancer is irregular, showing a bimodal distribution of fluorescence, with a significant population of cells fluorescing at a higher relative intensity. It is suggested that this elevation in protein concentration is due to an immune response to the presence of a neoplasm, and thus this technique may prove to be a useful indicator of malignancy.
Lymphocyte cytoplasmic refractive index (LCRI).
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Protein changes in lymphocyte cytoplasm: an indicator of immunological activity? [proceedings].
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Functional-clinical anatomy for physician's assistant students.
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Stereoscopic anatomy: evaluation of a new teaching system in human gross anatomy.
Traditionally, human gross anatomy teaching has revolved around anatomical dissection. Unfortunately, during the last decade a number of medical schools have experienced a decrease in the number of hours allotted to gross anatomy instruction compounded by a shortage of anatomical donors. This, in turn, has served to increase the difficulties of providing students with truly effective anatomical instruction. To help overcome this problem, a stereoscopic slide-based auto-instructional program has been developed as a substitute for dissection. Evaluation data suggest that this program, while having minor limitations in terms of anatomical orientation, does provide a viable alternative to dissection.
Development and application of the technique of auto-instruction to medical gross anatomy at Nebraska.
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Training teachers in the anatomical sciences.
A number of medical schools have initiated workshops to improve faculty teaching skills. Little effort, however, has been directed toward the pedagogical training of graduate students who are destined to become future medical science teachers. To help solve this problem, the faculty of the Department of Anatomy in the University of Nebraska College of Medicine recently developed a prototype teacher training program for graduate students in anatomy. Through formal course work and practical classroom experience, students are developing the skills requisite for effective teaching of the anatomical sciences. Student and faculty response to the training program has been enthusiastic, and the objectives and structure of the program can be applied to the production of competent and skilled teachers in other areas of the basic and clinical sciences.
Effects of hypophysectomy on DNCB-induced contact sensitivity in rats.
Cell-mediated immunity in hypophysectomized (HYX) and non-hypophysectomized (NHYX) rats was assessed by measuring lymph node weight and lymph node cellular proliferation responses to cutaneous application of the skin sensitizer dinitrochlorobenzene (DNCB). Differences were found in the lymph node weight assay, with the responses of the HYX rats being significantly lower than the responses of the NHYX rats. There were, however, no significant differences as measured by the lymph node cellular proliferation assay. An explanation for these contradictory results was sought by examining dose-responsiveness to DNCB. It was found that, over a range of doses of DNCB, HYX rats showed a linear dose-response relationship in terms of both lymph node weight and lymph node cellular proliferation. No dose-responsiveness was observed in NHYX rats. Since HYX rats required a greater degree of antigenic stimulation to achieve a response level equivalent to that of NHYX rats, it may be concluded that HYX rats are immunodeficient at lower antigen levels.
Undergraduate grade point average, science grade point average, and science hours as predicators of medical, physical therapy and physician's assistant students performance in gross anatomy.
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Proceedings: Auto-instruction in histology and cell biology as a substitute for traditional laboratory activities.
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Letter: Pulled elbow: evidence for a genetic factor.
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A systematic approach to the quantitative description of musculo-skeletal geometry.
1. A systematized computer technique of centroid analysis has been developed to evaluate the precise geometric relationship between a muscle and a bone and it has been applied to the abductor mechanism of the human hip joint. 2. The validity of the traditional use of straight lines for displaying the line of action of a muscle is open to serious question, although in the case of the gluteus medius the straight line simplification is not unmeasurable. 3. The determination of the precise interactions of muscles and bones is of major importance in the consideration of various orthopaedic procedures.
The Nebraska approach to quality medical education.
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Cancer case-finding in gross anatomy to stimulate student interest.
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