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Biomedical subjects

J W Yates

Publications and source records attributed to J W Yates.

At least 37 records · Page 2Linked to original sources
PubMed1987

Recovery of dynamic muscular endurance.

Recovery of the rate of dynamic muscular endurance was measured in two groups of college-aged males. Subjects were required to perform elbow flexion (between the angles of 70 and 170 degrees) for as long as possible at the rate of 38 contractions/min while loaded with 1/6 of their maximum isometric strength (MVC). The task was terminated when the subject fell four contractions behind the required cadence or failed to complete two successive contractions. Subsequent to the task the subject was given a predetermined rest period after which a second fatigue bout to failure was performed. The rest intervals for Gp I (n = 22) were 5, 15, 45, 135, 405, and 1215 seconds, while the rest intervals for Gp II (n = 17) were 10, 30, 90, 270, 810, and 2550 s. Each subject completed six recovery intervals with the order of administration assigned at random. The percentage of recovery was calculated by dividing the exercise time of the first bout into the time of the second bout. These normalized data for the two groups were combined for analysis providing a 12 point recovery curve. The percentage of recovery ranged from 15.4% after 5 s to 91.8% after 2550 s. Analysis of the data revealed that the recovery pattern of dynamic muscular endurance progressed very rapidly initially, reached 50% at approximately 2 min and 15 s and was slightly less than 90% complete at 20 min. Exponential analysis of these data yielded a three-component curve.

Adolescent↗
PubMed1987

Maximum acceptable lifting loads during seated and standing work positions.

The psychophysical method was used to determine the maximal acceptable load that eight males (age 22-30 years) would lift in each of four different positions: (1) seated, two-handed, symmetrical lift from a table, to a position 38 cm forward of the edge, (2) a seated lift from a position at the subject's side, on to a table in front of the subject involving a 90 degree twist of the torso, (3) standing, two-handed, symmetrical lift from the table, to a position 38 cm forward of the edge, and (4) standing, vertical lift from 86 above the floor. Subsequent to a training period, subjects lifted a tray with slotted handles at the rate of 1 or 4 lifts/min. Each subject chose the weight of the tray which was acceptable to him by adding or removing flat pieces of lead over a 45 min period. The weight of the tray, heart rate, and the perceived exertion were measured at 15, 30 and 45 min. Oxygen consumption was measured during the last 5 min of the 45 min experiment. Statistical analysis revealed a significant frequency and position effect. An increase in frequency from 1 to 4 lifts/min resulted in a decrease of 1.6 to 2.1 kg in the maximum acceptable weight for the various tasks. On average, the maximum acceptable weight of lift for standing positions was 16% greater than for sitting positions. Oxygen consumption and heart rate were significantly higher for 4 lifts/min than for 1 lift/min; however, the rating of perceived exertion did not differ for any factor.

Journal Article↗
PubMed1986

Legionnaires' disease in patients with cancer.

A 4-year experience with Legionella pneumophila (LD) diagnosed in 36 patients with cancer was reviewed. Cancer patients represented 24% of the total population of patients acquiring LD during that time. Hematologic neoplasms (42%) and lung cancer (22%) accounted for the majority of afflicted patients. Nosocomial infections occurred in 42% of the patients evaluated. Several risk factors were assessed, and only neutropenia, and previous steroid therapy played a causal role (p less than .05) when assessed in a retrospective case control fashion. Overall mortality in oncology patients with LD (53%) was high and underscores the need rapidly to diagnose and treat this entity. This mortality decreased after 1977 when an effective antibiotic was utilized. Mixed infections also played a major role in outcome and occurred in 31% of the 36 patients studied. The mortality in these cancer patients was 73%, and this emphasizes the need to exclude and treat concomitant bacterial or fungal infections.

Adult↗
PubMed1986

Ovarian cancer in the elderly: an analysis of Surveillance, Epidemiology, and End Results Program data.

With use of a unique data set from the Surveillance, Epidemiology, and End Results Program of the National Cancer Institute for 11,062 women diagnosed with ovarian cancer from 1973 to 1982, this study focuses on the impact of old age on this malignancy. Aspects of ovarian cancer as it pertains especially to elderly women (those 65 years or older) are examined according to age/stage relationships at initial diagnosis and age variations in treatment and survival. Elderly women are more likely than younger women to be in advanced stages of ovarian cancer at initial diagnosis, and they constitute about 42% of this group. In the stage-unknown category, over 50% are 65 years or older. Data suggest that elderly women are treated more conservatively than younger patients. The National Cancer Institute data also illustrate the increased preference to treat this neoplasm with surgical procedures and chemotherapy rather than surgical procedures and radiation. For Stages III and IV disease, 5-year relative survival rates for elderly women are almost one half of the rate observed for women under 65. Although the prognosis of patients with advanced ovarian tumors is poor for all, it is even worse as age progresses.

Age Factors↗
PubMed1986

An investigation of Jellinek's phases as they apply to both men and women.

Data comparing the symptom progressions reported by a group of 115 male alcoholics and 41 female alcoholics were correlated with the symptom progression described by Jellinek in 1952. Correlations were obtained for the phase marker symptoms, the phase markers and their phases, and for the overall progression. Results did not support Jellinek's model for the phase markers as reported by the men and by the entire group. Women, however, were shown to correlate perfectly with the phase markers as described by Jellinek. Significant correlations were obtained for the phase markers and their phases, and for the overall progression. Even though the correlations were significant, their values were not very great and this was taken as an indication of only modest support for Jellinek's symptom progression.

Alcoholism↗
PubMed1985

Multicentric reticulohistiocytosis and cancer: a case report and review of the literature.

Multicentric reticulohistiocytosis (MR) is a syndrome characterized by papulonodular skin lesions, a debilitating polyarthritis, and characteristic histologic findings. It is a rare disorder with only 82 cases reported. Twenty-eight percent had an associated neoplasm. Hematologic malignancies (four) and neoplasms arising from the breast (four), cervix (three), stomach (three), ovary (two), colon (two), lung (one), pleura (one), and from an unknown source (two) were all seen associated with MR. Eleven cases (including our own) were available for review. The papulonodular skin involvement was the initial manifestation (alone or concurrent with the polyarthritis) in 90% of our cases. The diagnosis of MR preceded that of the associated neoplasm in 73% of the cases. A case report is presented illustrating the relapse of MR before the clinical relapse of the associated tumor, and the response of both the tumor and MR to combination chemotherapy with cyclophosphamide, methotrexate, 5-fluorouracil, and prednisone when prednisone and aspirin alone failed to relieve the symptoms of MR. Steroids were not beneficial in the patients reviewed. The best management of MR associated with a neoplasm is the best management of the primary neoplasm. Cytotoxic chemotherapy including cyclophosphamide should be considered if there is progression of the MR in order to control the symptoms of MR and prevent a progressive debilitating arthritis.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1985

Gas exchange and lactate anaerobic thresholds: inter- and intraevaluator agreement.

Twenty-four coded graph sets of gas exchange variables and blood lactate concentration (LA) plotted against time at 15-s intervals were analyzed by nine evaluators who determined the gas exchange (ATGE) and LA (ATLA) anaerobic thresholds. In addition, ATGE and ATLA were determined by a linear regression computer program. Agreement between ATGE and ATLA was poor; the median intraclass correlation coefficient (ri) was 0.53. Among evaluators, ATLA agreement (median ri = 0.81) was better than ATGE agreement (median ri = 0.70). In general, the ability of any evaluator to choose similar values from duplicate plots for either ATGE (median ri = 0.97) or ATLA (median ri = 0.995) was good. There was better agreement between the mean ATLA of the evaluators and the computer ATLA (ComLA) (ri = 0.88) than between the mean ATGE of the evaluators and the computer ATGE (ComVE), (ri = 0.58). Agreement between ComVE and ComLA was poor (ri = 0.29). These results suggest that ATGE does not accurately predict ATLA and that different evaluators choose different thresholds from the same data. Further assessment of the validity and precision of ATGE based on breath-by-breath and minute-by-minute data is needed.

Adult↗
PubMed1984

Effect of a mandibular orthopedic repositioning appliance on muscular strength.

Three tests of large-muscle group strength were performed on 14 football players from the University of Louisville. Strength tests were performed with no mouthpiece, with a placebo mouthpiece, and with a MORA mouthpiece. A repeated measures ANOVA showed no significant differences between any of the tests, suggesting that the MORA has no effect on muscular strength.

Dental Occlusion↗
PubMed1983

A comparison of peak and constant angle torque-velocity curves in fast and slow-twitch populations.

Peak and constant angle torque-velocity (T-V) curves were measured on a group of fast-twitch (FT, n = 10) and slow-twitch (ST, n = 6) subjects using a Cybex dynamometer. The T-V curve was plotted from 10 randomly assigned velocities ranging from 0.52 to 5.24 rad s-1 (30 to 300 degrees s-1). Each subject was tested four times with at least 24 h between testing sessions. Torque-velocity curves were plotted from the peak torque generated throughout the range of motion and from torque produced at a constant angle (150 degrees). When all subjects were combined into a single group, no significant difference existed between the normalized T-V curves even though they differed significantly in absolute amounts. When subjects were grouped according to muscle fiber type the T-V curves produced from constant angle torque differed significantly while those generated from peak torque did not. This finding suggests that T-V curves generated from peak torque are not as sensitive to influences produced by muscle fiber type as those curves generated from constant angle torque.

Adult↗
PubMed1983

Lactic acid infusion in dogs: effects of varying infusate pH.

This study had two purposes: 1) to determine the effects of varying the pH of lactic acid infusion solutions on the acid-base status of anesthetized dogs, and 2) to determine the effect of elevated blood lactate concentration on muscle lactate concentration. The experiments were performed on the in situ gastro cnemius-plantaris muscle group in 14 mongrel dogs. The infusions increased the arterial blood lactate concentration to 11.0 +/- 0.5 (SE) mM after 20 min. Above an infusate pH of 4.4, the arterial pH increased by 0.118-0.167 during infusion; the arterial pH was unchanged when the infusate pH was between 3.4 and 4.0; and the arterial pH decreased as infusate pH decreased below 3.0. The effect of lactic acid infusion on blood pH appears to be the result of two opposing effects: 1) an acidifying effect due to its weak acid properties, and 2) an alkalinizing effect due to the metabolism of sodium lactate. The estimated ratio between intracellular muscle lactate and venous plasma water lactate averaged 0.647 +/- 0.038, indicative of a substantial gradient between blood and muscle. The infusion produced a significant change from lactate output to lactate uptake by the muscles. The infusion also transiently increased muscle blood flow and oxygen uptake.

Acid-Base Equilibrium↗
PubMed1983

Effects of prior dynamic leg exercise on static effort of the elbow flexors.

The isometric endurance of the elbow flexors was determined in a control condition and subsequent to a maximal effort exercise bout on a cycle ergometer in seven subjects. Maximum voluntary contraction (MVC), peak rate of tension development (+dP/dt), peak rate of tension relaxation (-dP/dt), one-half contraction time, and one-half relaxation time were also measured. Each subject was tested on four occasions: two control and two experimental sessions. During the control sessions each subject held 40% of MVC to exhaustion, whereas the experimental session included a 1-min maximal effort exercise bout on a cycle ergometer 6 min prior to the isometric endurance task. Arterialized blood samples were drawn and analyzed for lactate, pH, PCO2, and PO2. Plasma bicarbonate was calculated from the Henderson-Hasselbalch equation. Subsequent to the cycle ergometer bout, blood lactate concentration rose from 0.8 to 11 mM, pH decreased from 7.43 to 7.20, PCO2 decreased from 40 to 32 Torr, and plasma bicarbonate decreased from 26 to 12 mM. When compared with the control values, no significant changes were evident for any muscle contractile properties following the cycle ergometer bout. However, isometric endurance was significantly reduced from 115.0 +/- 7.2 to 86.3 +/- 7.3 s.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗