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Biomedical subjects

S M Davis

Publications and source records attributed to S M Davis.

144 records · Page 8Linked to original sources
PubMed1984

Positron imaging in ischemic stroke disease.

Positron emission tomography (PET) is well suited to the study of ischemic stroke disease. It has the potential to help elucidate pathophysiological mechanisms, differentiate viable from nonviable tissue, and provide a more rational basis for developing specific therapies for ischemic lesions. The different tracer strategies that may be applied to the study of ischemic disease, however, all have relative limitations, which may be related to the physical or biological determinants of the tracer distributions, to the tracer half-lives, or to the methods required for quantitation of the data. Determination of blood flow and oxygen metabolism are useful for characterizing stroke lesions, but other parameters, such as the oxygen extraction fraction, blood volume, and glucose metabolism, can provide important interpretative information. Correlation of the physiological PET data with the clinical presentation and course is a primary requisite for the development of the full potential of PET.

Adult↗
PubMed1984

High carboxyhemoglobin level without acute or chronic findings.

The clinical effects of carbon monoxide in humans have been well studied and described. Carboxyhemoglobin levels usually correlate with the degree of symptomatology; however, some investigators have noted that there may be a wide disparity between absolute carboxyhemoglobin levels and clinical status. A case is reported here of a young man with a potentially lethal level of carbon monoxide who developed neither significant symptomatology nor long-term sequelae. Until a more sensitive indicator of clinical outcome is found, clinicians must rely on carboxyhemoglobin levels and clinical history and examination to make treatment decisions, realizing that clinical presentation and absolute carboxyhemoglobin levels may correlate poorly.

Adult↗
PubMed1983

Adolescents' questions about sex.

Male and female Anglo, Hispanic and Native American adolescents from urban and rural areas were given a chance to ask anonymous questions about sex. These questions were then used as the bases for subsequent presentations on sex education. The most popular categories of questions were reproduction, sexuality, and contraception, followed by anatomy, venereal disease, pregnancy, abortion, vocabulary, hygiene, and other diseases. Younger adolescents asked significantly more questions in most categories than older ones. Girls asked significantly more total questions and ones concerning pregnancy, contraception, and anatomy than boys. Students attending rural schools asked more questions about venereal disease than those in urban schools, but no other main effects of urban-rural location were found. There were no ethnic differences found. The adolescents' questions ranged from sophisticated to poignantly ignorant, suggesting that the strategy of adapting sex education sessions to fit the concerns of the specific adolescents involved might be valuable.

Adolescent↗
PubMed1983

Cerebral blood flow and cerebrovascular CO2 reactivity in stroke-age normal controls.

We used the noninvasive 133-xenon inhalation technique to determine cerebral hemodynamics in 55 normal volunteers aged 18 to 88. Values for cerebral blood flow and cerebrovascular CO2 reactivity in fast-clearing tissue (flow gray) and slow-clearing tissue (flow white) were examined as functions of age and in relation to hematocrit, blood pressure, and evidence of extracranial vascular disease. Flow gray declined linearly with age, but no corresponding change was found in flow white or in CO2 reactivity. The data suggest that the progressive fall in flow gray is due to a physiologic aging process.

Adolescent↗
PubMed1982

The effect of amyl nitrite on the mitral valve echocardiogram in presumably healthy young adults.

We analyzed the use of amyl nitrite as a provocative factor in the diagnosis of mitral valve prolapse in a population of healthy young adults. Sixty-five men and 11 women underwent continuous M-mode echocardiographic and phonocardiographic monitoring before, during and after the administration of inhaled amyl nitrite. All of the 76 subjects had normal baseline echocardiograms, and all had a satisfactory hemodynamic response to amyl nitrite. Mitral valve prolapse, defined by echocardiography and phonocardiography, was not provoked in any of the subjects. Therefore, we concluded that, although this technique may be difficult, significant false-positive results should not occur if adherence to strict diagnostic criteria takes place.

Adult↗
PubMed1981

Stimulus-sensitive spinal myoclonus.

Two cases of spinal myoclonus are described; in both patients myoclonus was responsive to stimuli and absent during sleep. The first patient was considered to have viral neuronitis and the condition resolved spontaneously. The second patient had spinal cord ischaemia; there was electro-physiological evidence of abnormal alpha motor neurone activity and histological study of the spinal cord revealed a severe reduction in small and intermediate neurones. This supports the theory that spinal myoclonus may result from abnormal activity of alpha motor neurones released from control by spinal internuncial neurones.

Adult↗
PubMed1980

Biofeedback theory and application in allied health: speech pathology.

The implementation of biofeedback procedures represents a new approach to clinical management of speech disorders. Thus far, results of experiments utilizing biofeedback techniques have suggested positive effects in the remediation of speech disorders. The purpose of this paper is to provide the reader with the principles of biofeedback; to survey areas of clinical application including voice, fluency, and other clinical disorders; and to explore potential applications of biofeedback procedures for the speech and language pathologist.

Adolescent↗
PubMed1980

Disordered pigmentation, spastic paraparesis and peripheral neuropathy in three siblings: a new neurocutaneous syndrome.

Three siblings in a Jordanian family presented with a distinctive syndrome consisting of disordered skin and hair pigmentation, progressive spastic paraparesis and peripheral neuropathy. Sural nerve biopsy revealed axonal degeneration and skin biopsy showed abnormal epidermal pigmentation. Skin fibroblast repair studies were normal. No underlying biochemical defect has been found in this previously undescribed neurocutaneous syndrome.

Adolescent↗
PubMed1980

Auditory fusion in children.

"Auditory fusion" was defined in terms of a listener's ability to distinguish paired acoustic events from single acoustic events. Children from the ages of 3-12 years listened to 270 pairs of tones controlled for frequency, intensity, and duration. Stimuli consisted of numerous pairs of tone pulses, separated by interpulse intervals that varied systematically from 0 through 40 msec. Results indicate that (a) auditory fusion improves rapidly and in an orderly fashion between 3 and 8 years of age, (b) signal intensity affects the fusion point, and (c) stimulus frequency--253 hertz through 4,000 hertz, at 5-octave intervals--does not affect the fusion point.

Auditory Perception↗
PubMedDate not supplied

Methodological advances and plans for improving regulatory success for confirmatory studies.

Regulatory success for new medical products requires convincing statistical results from planned analyses for relevant and reliable data from well-designed clinical studies. Statistical methodology has a critical role for such success through strengthening the robustness of study findings to sources of bias, variability and spurious events. Areas of particular importance for statistical methodology include the structure for study design, the schedule and procedures for data collection, and plans for primary data analyses. This paper discusses some challenging statistical issues for these areas and suggests potential strategies for addressing them. The objective of these strategies as well as other methodological advances is the minimization of ambiguity in the findings of confirmatory studies. In this way, their effective use can enhance regulatory success.

Bias↗
PubMedDate not supplied

Enrichment for academic success: helping at-risk students.

Successful retention of at-risk nursing students is best accomplished through an organized system that addresses their individual needs in the areas of academic, cognitive, and self-enhancement skills. The cooperative endeavors of students, faculty, and administrators in the development of one such system, Enrichment for Academic Success, has resulted in a 95% retention rate among participants. The authors describe the incentive, development, implementation, and value of the system which can be adapted to any setting with adequate human and material resources.

Education, Nursing, Baccalaureate↗
PubMedDate not supplied

Body image and weight concerns among Southwestern American Indian preadolescent schoolchildren.

This study was undertaken to determine whether perceptions about body image and size vary by body mass index (BMI) and demographic factors among American Indian children in the Southwestern United States. We surveyed 1,996 American Indian schoolchildren in the fifth grade (mean age 10.5 +/- 0.7 years) at eleven rural elementary schools. Heights and weights were measured using standard protocol. Multiple linear regression models were developed for preferred body shape, desired body shape, and body satisfaction to determine association with demographic and physical factors. Results from multiple linear regression modeling indicated that BMI and gender influence body satisfaction, with heavier children and girls being less satisfied with their bodies (P<.001 and P<.05, respectively). Geographic isolation and lack of amenities in the home did not appear to affect body satisfaction or messages from others about being too fat or thin; however, geographically isolated students were more likely to choose a larger body shape as best looking. Girls of appropriate weight were 2.2 times more likely than boys to have been told they were too fat. Sixty-one percent of all students surveyed had tried to lose weight. These findings, although similar to those for non-Hispanic Whites of the same age, are contrary to prevailing ideas that American Indians value obesity. In fact, we observed a high level of body dissatisfaction among children of appropriate weight, particularly girls, and prevalent dieting across all weight categories and both genders.

Attitude↗
PubMedDate not supplied

Improving the health of Indian teenagers--a demonstration program in rural New Mexico.

The health status of Indian teenagers in the United States is below that of the general population. The usual barriers to the use of health care services that young people, including young Indians, encounter are compounded in rural areas by distance, isolation, and lack of appropriate services. To overcome these barriers in rural New Mexico, a public health demonstration project (a) established a single location where adolescents can receive multiple, integrated health care services free of charge; (b) set up the initial program of services at a rural school; (c) established links with existing agencies; and (d) incorporated community action toward creating change. The project began as a joint effort of three communities, the University of New Mexico (UNM), and the Albuquerque Area Indian Health Service (IHS) of the Public Health Service; a secondary level public school soon became a participant. The project is being replicated in two other communities that have formed separate partnerships with UNM and the area IHS; also the New Mexico Health and Environment Department has joined the effort in one community. Preliminary data suggest that the services are being used by a majority of the target population, with the proportions of boys and girls about equal.

Adolescent↗