Pathological effects of cyanobacteria on sea fans in southeast Florida.

In early August 2008, observations by divers indicated that sea fans, particularly Gorgonia ventalina, Gorgonia flabellum, and Iciligorgia schrammi, were being covered by benthic filamentous cyanobacteria. From August 2008 through January 2009 and again in April 2009, tissue samples from a targeted G. ventalina colony affected by cyanobacteria and from a nearby, apparently healthy (without cyanobacteria) control colony, were collected monthly for histopathological examination. The primary cellular response of the sea fan to overgrowth by cyanobacteria was an increase in the number of acidophilic amoebocytes (with their granular contents dispersed) that were scattered throughout the coenenchyme tissue. Necrosis of scleroblasts and zooxanthellae and infiltration of degranulated amoebocytes were observed in the sea fan surface tissues at sites overgrown with cyanobacteria. Fungal hyphae in the axial skeleton were qualitatively more prominent in cyanobacteria-affected sea fans than in controls.

Comparing patient, parent, and staff descriptions of fatigue in pediatric oncology patients.

Fatigue in children and adolescents with cancer is a disruptive symptom meriting clinical intervention by nurses, but has eluded definition, measurement, and intervention. Fatigue in these patients exists within a greater context of illness, treatment, and child and family development. Any effort to define, measure, and intervene with fatigue needs to take into consideration the major components of these children and adolescents' treatment context. The purpose of this descriptive study was to learn from three perspectives (patient, parent, and staff) how fatigue is identified and defined in 7- to 12-year-old children and in 13- to 18-year-old adolescents with cancer, and what factors contribute to or alleviate this fatigue. To elicit this information, separate focus groups were conducted with patients, parents, and staff at two pediatric oncology centers. Resulting interview data were analyzed using pragmatic and semantic content analysis techniques and the Wilson concept analysis process. Findings clearly indicated that children, adolescents, parents, and staff define patient fatigue differently. The conceptual definition from the child data emphasizes the physical sensation of the fatigue; alternating and at times merging physical and mental tiredness are emphasized in the adolescent's definition. Parents and staff view themselves as responsible for alleviating patient fatigue; patients viewed rest and distraction as their primary sources of improving fatigue. The conceptual definitions of fatigue as rendered by our three groups of participants can assist pediatric oncology patients, their parents, and staff in identifying fatigue. Factors identified by these participants as contributing or alleviating fatigue could be the basis for future interventions designed to reduce fatigue in pediatric oncology patients.

Fatigue in 7- to 12-year-old patients with cancer from the staff perspective: an exploratory study.

PURPOSE/OBJECTIVES: To document and analyze the perspectives of staff members who provide direct care to 7- to 12-year-old patients with cancer regarding the nature and characteristics of fatigue, causes of fatigue, and effective interventions for this population of young patients. DESIGN: Exploratory. SETTINGS: A pediatric oncology unit at a children's hospital in the southwest and a pediatric research center for childhood catastrophic diseases in the mid-south. SAMPLE: A convenience sample of 38 staff members (8 advanced practice nurses, 23 staff nurses, 2 nurses managers, 3 nutritionists, 1 chaplain, and 1 physician) whose experience in pediatric oncology ranged from two months to 23 years. METHODS: Nine open-ended questions were posed to staff members during focus group sessions. Staff responses were analyzed using content analysis techniques and the Wilson concept analysis technique. MAIN RESEARCH VARIABLE: Staff perceptions of fatigue in 7- to 12-year-old patients with cancer. FINDINGS: Fatigue is a state of diminished to complete loss of energy or will that is influenced by environmental, biochemical, personal, cultural, and treatment-related factors. This state, which may be acute, episodic, or chronic, can be accompanied by a changing emotional or mental state. CONCLUSIONS: Staff perceive fatigue to be a debilitating symptom for these children. When attempting to determine the presence or absence of fatigue, staff primarily compare a child's current state with his or her previous state rather than that of other children. Staff see themselves as having a role in causing and alleviating fatigue in this patient group. IMPLICATIONS FOR NURSING PRACTICE: Staff can use these findings to help them identify the presence of fatigue in these children and to identify contributing and alleviating factors.

Comparison of methods for evaluating exercise-induced changes in thromboxane B2 and beta-thromboglobulin.

This study compared the effects of exercise or TXB2 and beta-TG when evaluated by four methods: 1) not adjusted; 2) adjusted for plasma volume changes (PV); 3) standardized per 10(5) platelets (PC); 4) or both PC and PV (PC-PV). Blood was collected from 16 men (41.3 +/- 8.1 yr) at rest after 30 min of exercise (IPE) and after 30 min recovery. Resting TXB2 and beta-TG concentrations were 62.0 +/- 6.2 pg.mL-1 and 129.8 +/- 12.5 ng.mL-1, respectively. When expressed on a per 10(5) platelet basis, resting PCTXB2 was 23.8 +/- 2.8 pg.mL-1.10(5-1) platelets and PC beta-TG was 50.77 +/- 6.0 ng.mL-1. 10(5-1) platelets. At IPE, TXB2 decreased 20.5% and beta-TG increased 13.6%. Thirty minutes after exercise TXB2 was 4.2% lower than resting values, whereas beta-TG was 26% higher. TXB2, beta-TG, PVTXB2, and PV beta-TG were not significantly altered by exercise. The only significant changes in TXB2 occurred at IPE when values were adjusted for changes in platelet count. At IPE, PCTXB2, and PC-PVTXB2 decreased 32.8% and 33.6%, respectively (P < 0.05). Similarly, beta-TG were not altered significantly by exercise except when the samples taken after 30 min of recovery were adjusted for changes in platelet count. At 30 min post-exercise PC beta-TG and PC-PV beta-TG were 21.2% and 28.4% greater (P < 0.05) than the resting beta-TG values. These data suggest that methods used to adjust concentrations of platelet derived substances for changes owing to exercise may influence conclusions about the effect of exercise on platelet function. Thus, it is imperative that researchers consider the purpose for which they are collecting TXB2 and beta-TG, as well as other constituents derived from blood cells, before they determine which methods of analysis to use.

Short-term changes in 10-km race pace aerobic demand and gait mechanics following a bout of high-intensity distance running.

Following treadmill accommodation and a 3-day period of tapered running, ten well-trained male distance runners [x maximum oxygen uptake (VO2max) = 71.3 ml.kg-1.min-1] performed two 10-min level treadmill runs designed to assess running economy at 90% VO2max. Video recordings were obtained during the last minute of each run to quantify selected gait descriptors. Two to 3 days following the second economy run, each subject completed 30 min of high-intensity (HI) running at 90% VO2max. One 2, and 4 days after the HI run, subjects repeated the 10-min economy runs. Compared to pre HI-run values, no significant change (P > 0.05) in running economy was observed during the post-HI runs. Biomechanical analyses also revealed that running style remained unaltered after the HI run. These results support earlier findings obtained on moderately trained subjects featuring measurement of running economy and gait mechanics at less-demanding intensities and suggest that among well-trained athletes, 30 min of HI running does not elicit an increase in VO2 or disrupt gait mechanics over the short term in subsequent distance runs performed at near-maximal speeds.

Effects of feed additives and veterinary drugs on aldosterone production and release by porcine adrenal cells in vitro.

The preparation of suspensions of porcine adrenocortical cells is described. Within the conditions adopted, the cell suspension responded to various agents as expected. It was possible to screen drugs (standard range 0.3-100 microM, incubation period 1 h) for actions on the production/release of aldosterone by the cortical cells using 1 microM deoxycorticosterone as substrate. Progesterone, pregnenolone or corticosterone were also used as substrates. Feed additives of the quinoxaline type induced a slowly developing inhibition of aldosterone production/release by the cell suspension, which was virtually irreversible. During the standard 1 h incubation period inhibitions of up to 22 +/- 2% of control were observed, which increased upon prolongation of the incubation by 2 h. With 100 microM cyadox the inhibition increased from 19 +/- 2% to 35 +/- 2% with prolonged incubation. Ten nitrofuran compounds exerted a more rapidly developing inhibition (by up to 79 +/- 1% of control) of aldosterone production/release, which was reversible. A submaximal inhibition with 10 microM furazolidone of 21 +/- 5% increased to 40 +/- 1% with longer incubation. The concentrations at which these compounds exerted this effect in vitro were well below the peak blood plasma concentrations encountered after administration of the drugs in therapeutic doses. Polyether-antibacterials/ionophores rapidly inhibited aldosterone production/release (to 26 +/- 1% of control) and this effect was completely reversible. The nitroimidazole compounds tested did not affect aldosterone production/release when deoxycorticosterone or progesterone were used as substrates. With use of corticosterone and to a lesser extent with pregnenolone as substrates a clear inhibition (to 73 +/- 3% of control) of aldosterone production was obtained. Amprolium in concentrations up to 100 microM, with deoxycorticosterone as substrate, did not induce a significant change in aldosterone production/release by the suspension of adrenocortical cells. In the same dose range tylosin and roxarsone induced a small but significant inhibition (by up to 10 +/- 3% of control) of aldosterone production/release, which was not dose-dependent. It is concluded that a wide range of growth-promoting drugs may be able to change aldosterone production/release in the animal.

Daily variability in exercise ventilation.

The purpose of this study was to quantify daily variability in ventilation (VE) during submaximal exercise and establish the number of testing sessions required to produce stable exercise ventilation measures. Following 60 min of treadmill accommodation, four male (M) and four female (F) distance runners completed 5 weeks of daily treadmill testing at the same time of day while engaged in a normal routine of training and racing. During each test session, subjects completed three 6-min level treadmill runs at either 3.13, 3.57, and 4.02 m.sec-1 for F or 3.57, 4.02, and 4.47 m.sec-1 for M. Measures of VE were obtained during the last 2 min of each 6-min run. Results indicated that the mean coefficient of variation (CV) for VE across speeds was 4.33%. Reliability analyses examining all possible combinations of testing days over the 5-week period revealed that 97% of the variation in mean VE was accounted for in either 2 consecutive or non-consecutive days, while 98% of the variation in mean VE was accounted for in 5 consecutive days. These data suggest that when treadmill exposure and circadian variation are controlled, intraindividual differences in exercise VE are relatively small in male and female subjects following an unrestricted program of training and competitive racing. Additionally, acceptably stable VE values in this cohort can be derived by averaging duplicate measures obtained from consecutive or non-consecutive testing sessions.

Combined effects of age and exercise on thromboxane B2 and platelet activation.

Nine healthy young (27.8 +/- 0.8 yr old, YM) and nine healthy older men (55.4 +/- 1.3 yr old, OM) ran on a treadmill at 70-75% of maximal O2 consumption for 30 min to determine the combined effects of age and acute exercise on plasma thromboxane B2 (TxB2) and beta-thromboglobulin (beta-TG). Blood samples (10 ml) were collected in tubes containing 0.5 ml of 4.5 mM EDTA, 30 mM acetylsalicylic acid, and 1 microM prostaglandin E1 after 15 min of rest, immediately after exercise, and at 30 min of recovery. Concentrations of TxB2 and beta-TG were determined by radioimmunoassay. Samples were adjusted for hemoconcentration and changes in platelet count not accounted for by plasma volume shifts. Data were analyzed with repeated-measures analysis of variance and Tukey's post hoc technique. Resting TxB2 was 53.3 +/- 9.6 and 79.0 +/- 18.2 pg/ml for the YM and OM, respectively. beta-TG at rest was 152.5 +/- 13.9 and 114.0 +/- 10.9 ng/ml for the YM and OM, respectively. No significant age group or exercise-induced differences for TxB2 or beta-TG were found immediately after exercise. TxB2 in the OM (101.7 +/- 16.4 pg/ml) 30 min after exercise was significantly (P = 0.05) higher than that in the YM (54.4 +/- 6.2 pg/ml). beta-TG values 30 min after exercise were not significantly different: 183.3 +/- 26.9 and 169.9 +/- 17.0 ng/ml in the OM and YM, respectively. These data suggest that OM may experience greater increases in TxB2 than YM 30 min after exercise and may be more predisposed to platelet activation.

Daily variation in step length of trained male runners.

The purpose of this study was to quantify daily intra-individual variability in mean step length, a basic descriptor for the running pattern. Following 60 minutes of treadmill accommodation, nine trained male subjects (X age = 34.2 yrs +/- 7.2, X VO2max = 57.0 +/- 4.8 ml.kg-1.min-1) performed daily (Mon-Fri) 6-minute treadmill runs at three submaximal speeds (2.68, 3.13 and 3.58 m.s-1) over a 4-week period. To minimize extraneous influences, subjects refrained from road racing and completed the 20 running sessions (5 d.wk-1.4 weeks for each speed) at the same time of day and in the same footwear. Treadmill velocity was calibrated for each 6-minute running bout and step length was determined during the last 2 minutes of each run. Results indicated that mean step length and coefficient of variation values were 0.984 m and 2.50% at 2.68 m.s-1, 1.124 m and 2.22% at 3.13 m.s-1, and 1.254 m and 2.26% at 3.58 m.s-1. Reliability analyses indicated that the percentage of variation accounted for in step length across all speeds was high and improved very little as test number increased (range = 96% for two days vs 99% for five days). Taken together, these findings suggest that when testing conditions are controlled, within-subject variability in step length measures obtained at multiple submaximal running speeds is small in trained subjects and that criterion step length values can be obtained by averaging duplicate measurements.