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Biomedical subjects

A M Wilson

Publications and source records attributed to A M Wilson.

175 records · Page 10Linked to original sources
PubMed1966

Hexose-, inositol-, and nucleoside phosphate esters in germinating seeds of crested wheatgrass.

Net synthesis of phosphate esters was measured in crested wheatgrass seeds [Agropyron desertorum (Fisch.) Schult.] to learn what phosphorylating reactions occur in early stages of germination. Phosphate esters were separated on ion exchange columns and identified by cochromatography and chemical analyses. Synthesis of adenosine triphosphate and UDP-hexose was detected 6 hours after the beginning of water absorption. This synthesis occurred during the period of rapid increase in water potential. Synthesis of hexose phosphate and uridine triphosphate was detected 12 hours after the beginning of water absorption. The concentrations of these esters increased during 48 hours. Increases in concentration of inositol di-, tri-, and tetraphosphate suggested that hydrolysis of inositol hexaphosphate began after 12 hours.

Journal Article↗
PubMedDate not supplied

ATP loss with exercise in muscle fibres of the gluteus medius of the thoroughbred horse.

Muscle ATP loss with exercise has implications both to the causes of fatigue and muscle damage. To study this at the single muscle fibre level, five trained thoroughbred horses performed consecutive 90 second gallops on an inclined treadmill followed by a final gallop to fatigue. Biopsies of the m. gluteus medius were taken at rest, post-exercise and during 24 hour recovery. Blood lactate was 20.0 mmol litre-1 or more, and plasma NH3 300-800 mumol litre-1, following the final gallop. Minimal changes occurred in the plasma markers, CK and AST. ATP loss with exercise was 32.2 (SD 12.2) per cent. Following exercise single fibre ATP contents showed a much broader distribution than at rest, with contents in some close to zero. Following five and 24 hour recovery, however, frequency distribution curves were close to those seen at rest. There was no difference in the ATP contents of types I, IIa and IIb at rest of with exercise or recovery. The results pointed to marked heterogeneity between individual fibres in their biochemical response with exercise, independent of fibre type.

Adenosine Triphosphate↗
PubMedDate not supplied

Horses damp the spring in their step.

The muscular work of galloping in horses is halved by storing and returning elastic strain energy in spring-like muscle-tendon units.These make the legs act like a child's pogo stick that is tuned to stretch and recoil at 2.5 strides per second. This mechanism is optimized by unique musculoskeletal adaptations: the digital flexor muscles have extremely short fibres and significant passive properties, whereas the tendons are very long and span several joints. Length change occurs by a stretching of the spring-like digital flexor tendons rather than through energetically expensive length changes in the muscle. Despite being apparently redundant for such a mechanism, the muscle fibres in the digital flexors are well developed. Here we show that the mechanical arrangement of the elastic leg permits it to vibrate at a higher frequency of 30-40 Hz that could cause fatigue damage to tendon and bone. Furthermore, we show that the digital flexor muscles have minimal ability to contribute to or regulate significantly the 2.5-Hz cycle of movement, but are ideally arranged to damp these high-frequency oscillations in the limb.

Animals↗
PubMedDate not supplied

Persistence of phonological processing deficits in college students with dyslexia who have age-appropriate reading skills.

This study investigated the phonological processing skills of university students with dyslexia. Fifty-nine students participated in this study: 28 with reading disabilities based on recent psychological assessments and a history of early and persistent reading problems; and 31 controls. The two groups did not differ on estimates of verbal and nonverbal abilities. The dyslexia group performed significantly less well on standardized measures of reading and spelling. However, the dyslexia group scores on these measures fell within the average range. The main dependent variables were subsumed under three areas of phonological processing: phonological awareness, phonological recoding in lexical access, and phonological recoding in working memory. The control group performed significantly better on all phonological processing measures, particularly those measures involving accuracy and response times. Despite age-appropriate performances on standardized reading and spelling measures, phonological processing deficits persisted in the dyslexia group. These findings support the causal role of phonological awareness in the acquisition of reading skills and indicate that differences in phonological processing skills are still evident in a sample of university students with dyslexia compared a group matched on age and education.

Adolescent↗
PubMedDate not supplied

Health promoting behaviors of African-American registered nurses.

The purposes of this study were: (1) to describe the health promoting behaviors of African-American nurses, (2) to add to the health promotion data base for African-American women, and (3) to pilot test a self-administered questionnaire developed by the investigators for use in a larger study of the health-promoting behaviors of middle class African-American women. The sample consisted of 49 African-American registered nurses recruited from members of a nursing sorority. Selected criteria for the subjects were female, college graduate, and a middle class standard of living. A self-administered questionnaire was used to assess the likelihood of engaging in health-promoting behaviors. Descriptive statistics were used to describe the findings in terms of frequency and percentage distribution. The results indicated that the African-American nurses had high percentages of adherence to the following health-promoting behaviors: minimal alcohol consumption, avoidance of smoking, cholesterol screening, assessment of blood sugar levels, monthly breast self-examination, pap smears, mammogram screening and regular measurement of blood pressure. Lower percentages of adherence were reported for two health-promoting behaviors: diet and exercise. Results of this study support the need for the incorporation of diet and exercise into all health promotion intervention programs for African-American women. Implications include additional research to validate the findings of this study.

Adult↗