PubMed Health⌕ Search

Biomedical subjects

M M Williams

Publications and source records attributed to M M Williams.

At least 19 recordsLinked to original sources
PubMed1992

Muscle power predicts freestyle swimming performance.

The purpose of this study was to determine the relationship between non-invasive laboratory measures of 'muscle power' and swim performance over sprint (50 m) and middle-distance (400 m) events. Twenty-two swimmers performed an upper and lower body Wingate Anaerobic Test (WAT) and a maximal sustained power output test (MPO) for the upper body. Peak power (PP) and mean power (MP) were determined for the WAT, while peak sustained workload (WLpeak) was determined for the MPO. Timed swims over 50 m and 400 m were undertaken by all swimmers during which the number of arm strokes per length was recorded. Highly significant relationships were found between sprint-swim speed (S50) and mean power of the arms (MP(arms)) (r = 0.63, P less than 0.01), between S50 and mean power of the legs (MP(legs)) (r = 0.76, P less than 0.001) and between S50 and the distance covered with each arm stroke (DS) (r = 0.91, P less than 0.001). Multiple regression analyses revealed that WAT power indices for the legs did not significantly increase explained variance in S50 above that of the arms. The relationship between WL(peak) and S400 was highly significant (r = 0.70, P less than 0.001) and indicates the importance of arm power in the longer distance swim events.

Adolescent↗
PubMed1992

Subgroup and serotype epidemiology of human rotaviruses recovered at Ga-Rankuwa, southern Africa.

This study analysed human rotaviruses isolated in Ga-Rankuwa, South Africa, using monoclonal antibodies directed at the subgroup-specific and serotype-specific antigens of the virus. The subgroup could be determined for 73pc of the specimens. Subgroup II viruses occurred more commonly than subgroup I viruses (77pc vs 22pc). A serotype specificity could be assigned in 65pc of cases with three serotypes observed to be circulating in this population. Serotype one strains were identified most commonly (43pc) with serotype two (12pc) and serotype four (9pc) strains also present. No serotype three strains were detected. One strain was identified which reacted with both subgroup I and II monoclonal antibodies and with serotype one and two monoclonal antibodies. This study highlights the unpredictable nature of the emergence of new serotypes and importance of surveillance of human rotavirus infection in this sub-continental region.

Antibodies, Monoclonal↗
PubMed1992

Improvement in 'stat' laboratory turnaround time. A model continuous quality improvement project.

BACKGROUND: Continuous quality improvement is being advocated as the process that, if adopted, would improve the efficiency, productiveness, and quality of medical institutions, thereby helping to solve the health care crisis our country is facing. To determine if these techniques could be effective in a tertiary-care multispecialty group practice, a model project was undertaken. The model project chosen was to determine if we could improve the turnaround time for "stat" laboratory examinations performed in our large outpatient facility. METHODS: A 10-member team consisting of everyone involved in the process of laboratory testing was empowered to evaluate the present process and make appropriate changes. With traditional techniques of quality improvement, the process was assessed, data were collected and statistically analyzed, changes were introduced, and data were recollected and analyzed. RESULTS: After intervention, the preanalytic delays were reduced by 76% and the postanalytic delays by 88%. Waiting time for patients was reduced by an average of 62%. By instituting the changes suggested, the institution saved $225,000 on a one-time basis and $40,000 to $50,000 on a recurring basis. CONCLUSION: Adoption of quality improvement techniques appears to be a desirable management paradigm that should be explored by all medical institutions interested in maximizing the quality of care offered while at the same time minimizing its cost.

Ambulatory Care Facilities↗
PubMed1991

Relationship between upper body anaerobic power and freestyle swimming performance.

The purpose of this study was to examine the role of upper body anaerobic power, as measured by the Wingate Anaerobic Arm Test (WAAT), in 50-m sprint swim performance. Thirty competitive age-group swimmers (14 males and 16 females) participated in this investigation. Subjects had been training daily for 5 months prior to the study, swimming an average of 6,000 m.d-1, 6 d.wk-1. Swimmers performed a WAAT and a 50-m time-trial. Peak power (PP), mean power (MP) and fatigue index (FI) were determined for the WAAT. Subjects also reported their current competition performances for all distances up to 400 m. Significant relationships were obtained between swim speed over 50 m (S50) and PP (r = 0.82, p less than 0.001), S50 and MP (r = 0.83, p less than 0.001), and S50 and FI (r = 0.41, p less than 0.05). PP and MP showed significant but generally decreasing correlations with swim speed as distance increased. Substantial relationships (r = 0.74-0.96, p less than 0.001) were found between S50 and swim speeds over distances up to and including 400 m. This study shows a strong relationship exists between upper body anaerobic power, as measured by the WAAT, and performance in both sprint and longer distance (400 m) swim events. The WAAT may serve as a useful tool for coaches to objectively evaluate and monitor the upper body anaerobic power of competitive swimmers.

Acceleration↗
PubMed1991

A comparison of the effects of two sitting postures on back and referred pain.

This study compared the effects of sitting with portable supports in either a kyphotic or lordotic posture on low-back and referred pain. Two hundred ten patients with low-back and/or referred pain were randomly assigned to either a kyphotic posture or lordotic posture group. The kyphotic and lordotic postures were facilitated by the use of a flat foam cushion or lumbar roll, respectively. Pain location, back pain, and leg pain intensity were assessed over a 24-48-hour period under both standardized clinical settings and general sitting environments. When sitting with a lordotic posture, back and leg pain were significantly reduced and referred pain shifted towards the low back. This study demonstrates that in general sitting environments a lumbar roll results in: 1) reductions in back and leg pain; and 2) centralization of pain. These findings do not apply to patients with stenosis or spondylolisthesis, whose symptoms may be aggravated by use of a lumbar roll.

Adult↗
PubMed1991

Dietary intakes of age-group swimmers.

The purposes of this study were to collect information regarding the dietary habits of male and female age-group swimmers and report the energy consumptions of these athletes in relation to their daily training demands. Twenty competitive swimmers, who were training 6000 m per day 6 days a week, recorded all fluid and food consumed during a 4-day period. Dietary analysis revealed that 11 swimmers (55%) had calcium intakes below recommended dietary allowances (RDA), while 13 (65%) had iron intakes lower than RDA. Despite identical training loads and body mass, male swimmers had significantly greater (P = 0.004) daily mean (s.d.) energy consumption (3072(732) kcal, 12.9(3.1) MJ) than females (2130(544) kcal, 8.9(2.3) MJ) and were maintaining energy balance. Although the contribution of carbohydrate to total daily energy intake was the same for male (55%) and female swimmers (56%), the females ingested significantly less (P = 0.011) carbohydrate (292(87) g) than the males (404(88) g) and could be considered deficient in dietary carbohydrate with respect to their daily training demands.

Adolescent↗
PubMed1991

Regulation of interleukin-1 and tumour necrosis factor gene expression in myelomonocytic cell lines by 1,25-dihydroxyvitamin D3.

1,25-dihydroxyvitamin D3[1,25-(OH)2D3] is capable of regulating cells in the immune system and affects cytokine production by both T lymphocytes and by monocytes. We examined the effects of 1,25-(OH)2D3 on the regulation of interleukin-1 beta (IL-1 beta) and tumour necrosis factor-alpha (TNF-alpha) genes in HL-60 and U937 cells. 1,25-(OH)2D3 alone only induced low level expression of the genes for these cytokines. Phorbol 12-myristate 13-acetate (PMA) strongly induced the transcription of these genes, whilst the addition of 1,25-(OH)2D3 to PMA-stimulated cells caused a further dose-dependent synergistic increase in the mRNA for both cytokines in U937 cells. In PMA-stimulated HL-60 cells, 1,25-(OH)2D3 increased the mRNA for IL-1 beta but not that for TNA-alpha, These differences may be related to the different stage of myeloid differentiation in HL-60 and U937 cells.

Blotting, Northern↗
PubMed1989

Effects of a task-specific warm-up on anaerobic power.

Twenty-four untrained (UT) males (age 21 +/- 2.5 yr, height 1.77 +/- 0.05 m, weight 75.3 +/- 10.1 kg, values mean +/- SD) performed the Wingate Anaerobic Test (WT) under two conditions, cold (C) and following a warm-up (WU). Trials were separated by a minimum of 48 h. A modified Monark 818 cycle ergometer was interfaced with an Apple IIE microcomputer and peak power (PEAK), mean power (MEAN) and fatigue index (FI) determined. The WU trial consisted of an 8 min incremental continuous cycling bout (cadence 90 rev.min-1) with 5 min rest before the WT. During the C trial subjects completed only the WT. A repeated measures design was employed with order of trials counterbalanced. ANOVA revealed no significant differences for PEAK or MEAN between WU or C conditions. However FI was significantly greater (p less than 0.05) following the WU. A significant correlation (r = 0.45, p = 0.03) was obtained between WU intensity and FI. These findings suggest that our UT subjects were fatiguing themselves during the WU. Future studies are needed to assess whether a task-specific WU in which FI is not impaired would lead to improvements in PEAK and MEAN. Investigators should be aware that a self-spaced WU may increase FI in the WT in UT subjects.

Adult↗
PubMed1989

Early regulation of c-myc mRNA by 1,25-dihydroxyvitamin D3 in human myelomonocytic U937 cells.

The effects of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3; 10 nmol/l) on the human monomyelocytic cell line U937 were investigated. Addition of 1,25-(OH)2D3 led to a decrease in cell proliferation which fell at 72 h to 67.8 +/- 4.3% (mean +/- S.E.M.) of control values. The presence of CD14, a surface marker found on mature monocytes/macrophages but not on U937 cells, was detectable as early as 18 h and peaked at 48 h, when 63.6 +/- 4.2% of the cells were positive. However, changes in c-myc mRNA levels were detected earlier, starting within 4 h of exposure to the hormone and being reduced to 38 +/- 8.2% of control values of 24 h. These effects were reversible after removal of the hormone, with the same sequence of events seen following addition of the hormone. There was first an increase in c-myc mRNA levels, starting within 2 h and reaching control values by 24 h. These changes were followed by loss of CD14 which became undetectable after 72 h. Proliferation recovered slowly and incompletely, since it was 81.7 +/- 0.7% of control after 72 h. A constant reciprocal relationship between c-myc mRNA and CD14 levels was found both in the presence and after removal of 1,25-(OH)2D3. Regulation of U937 cell proliferation and maturation by 1,25-(OH)2D3 is thus preceded by early modulation of c-myc mRNA.

Blotting, Northern↗
PubMed1989

1,25-Dihydroxyvitamin D3, but not retinoic acid, induces the differentiation of U937 cells.

We have examined the effects of vitamin D3 metabolites and retinoic acid on the myelomonocyte cell line U937. Inhibition of proliferation, measured by incorporation of 125iodo-deoxyuridine was seen at 72 h with 1,25-(OH)2D3 but not 25(OH)D3 or 24, 25(OH)2D3 metabolites. CD14 molecules, not normally present on U937 cells, were induced on the cell surface. However, Class II major histocompatibility complex (MHC) molecules were not induced and Class I MHC molecules not increased in density as determined by flow cytometry. Retinoic acid inhibited proliferation but failed to induce CD14 molecules. These data suggest that both 1,25(OH)2D3 and retinoic acid act as an antiproliferation signal to U937 cells; only 1,25-(OH)2D3 induces the differentiation towards a more mature phenotype.

Calcitriol↗
PubMed1987

Relation of alveolar size to forced vital capacity in professional divers.

Eight cases have been studied in which both lung function and histological morphometric data was available on divers' lungs. A correlation was found between the increase in forced vital capacity measured at routine annual medical examination and the morphometric measurement of alveoli by mean cord length. The results suggest that reduction of forced expiratory volume in one second may be due to narrowing of small airways by distention of the alveoli.

Adult↗
PubMed1974

The third decade.

Explore the source record for details and available documents.

History of Nursing↗