Effect of aerobic and resistance exercise training on vascular function in heart failure

Exercise training of a muscle group improves local vascular function in subjects with chronic heart failure (CHF). We studied forearm resistance vessel function in 12 patients with CHF in response to an 8-wk exercise program, which specifically excluded forearm exercise, using a crossover design. Forearm blood flow (FBF) was measured using strain-gauge plethysmography. Responses to three dose levels of intra-arterial acetylcholine were significantly augmented after exercise training when analyzed in terms of absolute flows (7.0 +/- 1.8 to 10.9 +/- 2.1 ml x 100 ml(-1) x min(-1) for the highest dose, P < 0.05 by ANOVA), forearm vascular resistance (21.5 +/- 5.0 to 15.3 +/- 3.9 ml x 100 ml forearm(-1) x min(-1), P < 0.01), or FBF ratios (P < 0.01, ANOVA). FBF ratio responses to sodium nitroprusside were also significantly increased after training (P < 0.05, ANOVA). Reactive hyperemic flow significantly increased in both upper limbs after training (27.9 +/- 2.7 to 33.5 +/- 3.1 ml x 100 ml(-1) x min(-1), infused limb; P < 0.05 by paired t-test). Exercise training improves endothelium-dependent and -independent vascular function and peak vasodilator capacity in patients with CHF. These effects on the vasculature are generalized, as they were evident in a vascular bed not directly involved in the exercise stimulus.

Slit inhibition of retinal axon growth and its role in retinal axon pathfinding and innervation patterns in the diencephalon

We have analyzed the role of the Slit family of repellent axon guidance molecules in the patterning of the axonal projections of retinal ganglion cells (RGCs) within the embryonic rat diencephalon and whether the slits can account for a repellent activity for retinal axons released by hypothalamus and epithalamus. At the time RGC axons extend over the diencephalon, slit1 and slit2 are expressed in hypothalamus and epithalamus but not in the lateral part of dorsal thalamus, a retinal target. slit3 expression is low or undetectable. The Slit receptors robo2, and to a limited extent robo1, are expressed in the RGC layer, as are slit1 and slit2. In collagen gels, axon outgrowth from rat retinal explants is biased away from slit2-transfected 293T cells, and the number and length of axons are decreased on the explant side facing the cells. In addition, in the presence of Slit2, overall axon outgrowth is decreased, and bundles of retinal axons are more tightly fasciculated. This action of Slit2 as a growth inhibitor of retinal axons and the expression patterns of slit1 and slit2 correlate with the fasciculation and innervation patterns of RGC axons within the diencephalon and implicate the Slits as components of the axon repellent activity associated with the hypothalamus and epithalamus. Our findings suggest that in vivo the Slits control RGC axon pathfinding and targeting within the diencephalon by regulating their fasciculation, preventing them or their branches from invading nontarget tissues, and steering them toward their most distal target, the superior colliculus.

Exploring the role of the district nurse in rehabilitation

This article reviews the available literature to examine the district nurse's contribution to rehabilitation of the older patient in the community. It is argued that policy and demographic changes indicate that there is a demand for nursing care in the home that enables individuals and their carers to live with chronic health problems and develop strategies that maintain and improve their health. The ways in which district nurses incorporate an understanding of patient rehabilitation within their work is discusses. It is suggested that although there is an expectation that district nurses can and should be involved in planning and supporting rehabilitation for their patients, the process is often poorly defined, hampered by contextual problems and dependent on the cooperation and support of others. Furthermore, in specific areas of care such as cardiac rehabilitation and services for those recovering from stroke, there would appear to be an increase in specialist nurses who either undertake or coordinate the rehabilitation process for patients. This raises questions regarding how district nurses should develop their skills in rehabilitation and what strategies could be adopted to develop patterns of work that ensure collaboration and development rather than overlap and duplication.

Combined aerobic and resistance exercise training improves functional capacity and strength in CHF

This study examined the effect of a novel circuit weight training (CWT) program on cardiorespiratory fitness, muscular strength, and body composition in 13 patients with chronic heart failure (CHF), using a prospective randomized crossover protocol. Peak exercise oxygen uptake (VO(2 peak)) increased after the 8-wk CWT program (19. 5 +/- 1.2 vs. 22.0 +/- 1.5 ml. kg(-1). min(-1), P < 0.01), as did exercise test duration (15.2 +/- 0.9 vs. 18.0 +/- 1.1 min, P < 0. 001). Submaximal exercise heart rate was lower after training at 60 and 80 W (121 +/- 3 vs. 134 +/- 5 beats/min, P < 0.01) as was rate pressure product, whereas ventilatory threshold increased, from 52 +/- 3 to 58 +/- 3% of VO(2 peak) (P < 0.05). CWT also increased maximal isotonic voluntary contractile strength for seven different muscle groups, from 392 to 462 kg (P = 0.001). CWT, an exercise prescription specifically targeting peripheral abnormalities in CHF, improves functional capacity and muscular strength in these patients.

Increased pregnancy rates after IVF/ET with intravenous immunoglobulin treatment in women with elevated circulating C56+ cells

Intravenous (IV) immunoglobulin (Ig) has been previously shown to increase pregnancy rates after previously failed in vitro fertilization (IVF) embryo (ET) attempts in women who are efficient embryo producers (fertilize at least 50% of oocytes retrieved and generate at least 3 embryos/cycle). Women experiencing implantation failure have a higher frequency of elevated percentage of circulating CD56+ (natural killer) cells (>12%) than fertile women (3-12%). To evaluate the effects of IVIg on pregnancy rates in women with elevated percentage of circulating CD56+ cells, 32 women who had previously failed IVF/ET (>12 embryos transferred without pregnancy) were studied. Pregnancy and live birth rates with and without IVIg were compared in the same woman. All 32 women had previously failed to conceive after at least 12 ET, were efficient embryo producers and had persistently elevated plasma concentrations of CD56+ cells. Each woman received IVIg 500mg/kg prior to ET. If serum hCG concentrations were positive for pregnancy, IVIg was continued at 500mg/kg/mo until 28 weeks gestation. Pregnancy rates with and without IVIg were 56% and 9% (P<0.0001). The rate of live birth was 38% with IVIg and 0% without IVIg (P<0.0001). IVIg enhances pregnancy and live birth rates in women with elevated circulating CD56+ cells who have a history of implantation failure. Despite technologic advances leading to enhancement of fertilization rates after in vitro fertilization (IVF) (1, 2) implantation rates after embryo transfer (ET) have not increased significantly (3) over the last 20 years (4). Implantation rates after IVF/ET are influenced by the quality of the embryos and receptivity of the endometrium (3-9). Endometrial receptivity involves both hormonal (10-13) and immunologic (14-29) factors. Among the immunologic factors that play a crucial role in successful implantation are natural killer (NK) cells (14-18). NK cells present within the decidua that express CD56(but lack CD 16) have been associated with successful implantation (14-18). A deficiency of decidual CD56+ CD16- cells (18) and an increase in circulating CD56+ cells (25, 26) have been observed in women experiencing implantation failure. Women experiencing implantation failure after IVF and multiple ET have been successfully treated with intravenous (IV) immunoglobulin (Ig) (27). IVIg reduces activation of NK cells and NK killing activity both in vitro (29) and in vivo (30-31). This reduction in activation of NK cells is essential for normal implantation to occur (14). To further define the role of IVIg for treatment of implantation failure, pregnancy and live birth rates were compared before and after IVIg treatment in women undergoing IVF/ET who had elevated levels of circulating CD56+ cells.

Role of capillaries in determining CBF reserve: new insights using myocardial contrast echocardiography

To define the role of capillaries in the control of coronary blood flow (CBF) reserve, we developed a model of the coronary circulation and evaluated experimental data in its context. Our model comprised three compartments connected in series (arterial, capillary, and venous), each with its own resistance. The resistance in each vascular compartment was derived from the model based on hemodynamic data obtained in nine dogs during baseline and stenosis, both at rest and during hyperemia. The capillary hydrostatic pressure was assumed to be constant in all stages. Although in the absence of stenosis, the contribution of capillaries to total myocardial vascular resistance was only 25 +/- 5% at rest, it increased to 75 +/- 14% during hyperemia, despite the total myocardial vascular resistance decreasing by 51 +/- 13%. In the presence of a noncritical stenosis, total myocardial vascular resistance decreased by 22 +/- 10% at rest, with no change in capillary resistance. During hyperemia, total myocardial vascular resistance increased by 58 +/- 50% in the presence of the noncritical stenosis. In this situation, because arteriolar and venular resistances were already minimal, the increase in myocardial vascular resistance was due to increased capillary resistance, making it the predominant source (84 +/- 8%) of total myocardial vascular resistance. Myocardial video intensity (VI) on myocardial contrast echocardiography (MCE), which reflects capillary blood volume, decreased distal to the stenosis during hyperemia. In the presence of a flow-limiting stenosis at rest, myocardial VI also decreased, indicating that decrease in CBF was associated with an increase in capillary resistance. Our findings also provide an alternative explanation for the critical coronary closing pressure. Thus, contrary to previously held notions, capillaries play a vital role in the regulation of CBF.

The effect of intramuscular iron injections on serum ferritin levels and physical performance in elite netballers

The purpose of this study was to determine the effect of iron supplementation by intramuscular injection on both serum ferritin (SF) levels and exercise performance in iron depleted, non-anaemic elite female netballers. Fifteen iron depleted (Serum Ferritin <40 ug x L(-1). Haemoglobin >125 g x L(-1)) subjects (19+/-3 y) first performed their routine test battery: a vertical jump test, a 10s power and 5x6s repeat sprint test on a cycle ergometer and a 20m multi-stage shuttle run. Subjects were matched on the basis of height, mass, and playing position and then assigned to either a Ferritin Group (FG) or Placebo Group (PG) (single blind design). Subjects then underwent a course of 5x2ml intramuscular injections of either Ferrum H (FG) or normal saline (PG) over a period of 8-10 days before repeating the blood and physical performance tests. Five and 10 days following supplementation, SF levels in the FG increased significantly from baseline levels (P<0.05) and were also significantly greater than levels measured in the PG (P<0.01). Haemoglobin levels remained unchanged in both groups. All test scores remained unchanged from baseline values and were not different between the two groups. These results demonstrate that a course of 5x2ml intramuscular iron injections significantly increased SF concentration within 2 weeks without increasing Hb levels, but this rapid elevation did not enhance the physical performance in selected tests of iron depleted, non-anaemic athletes.

Colour Doppler indices of follicular blood flow as predictors of pregnancy after in-vitro fertilization and embryo transfer

Peak systolic velocity (PSV) of individual follicles has been correlated with oocyte recovery, fertilization rate and embryo quality [in women undergoing in-vitro fertilization (IVF) and embryo transfer]. The present study assessed the role of quantitative and qualitative indices of follicular vascularity in predicting pregnancy after IVF and embryo transfer. A total of 106 women undergoing IVF treatment for infertility who were considered to be at risk of failure (>37 years of age, history of low response to gonadotrophin stimulation, or multiple failed IVF cycles) constituted the study group. PSV was measured from the three largest follicles on both the right and left ovaries on the day of human chorionic gonadotrophin (HCG) administration using an Acuson Sequoia with a 4-8 MHz transvaginal probe. The quality of follicular flow was graded from 1 to 4 according to the amount of visible colour flow around the follicle (grade 1 when one-quarter of the follicle, grade 2 when one-half, grade 3 when three-quarters, and grade 4 when the entire follicle was surrounded by colour). Clinical pregnancies resulted in 11 (10%) of the 106 high-risk women. Women who had PSV >/= 10 cm/s in at least one follicle on the day of HCG administration more often became pregnant than those with PSV <10 cm/s (P = 0.05). All pregnancies occurred in women with grade 3 or 4 follicular blood flow. Qualitative as well as quantitative measurements of follicular flow predict pregnancy after IVF and embryo transfer.

Roundtable discussion. Investigational exclusion, clinical trials, and cancer

Clinical trials are critical for developing and testing new treatments for cancer, but a panel of experts agreed that the state of clinical trials in the United States today is a "mess." How did we get into this situation in the first place, and how can we extricate ourselves? Should the federal government assume greater responsibility for funding and overseeing clinical trials and for establishing a standard health benefit package that defines the right to participate in clinical trials? The panel explored whether decisions to exclude patients are based on medical necessity and scientific merit or on the bottom line; whether insurance companies promise more than they can deliver; whether pharmaceutical companies are doing their share; and why lawyers are getting any share. In the end, the participants expressed hope that we, as a society, can get clinical trials back on track to serve their legitimate scientific and medical purposes.

Emphasizing terminal care as district nursing work: a helpful strategy in a purchasing environment?

This paper describes how within a study on the experiences of district nurses since the introduction of general practitioner purchasing, participants were encouraged to describe and define the district nursing service. The identification of terminal care by district nurses and others as a significant and defining example of district nursing work is explored and the possible reasons for its emphasis over other aspects of patient care. The extent to which terminal care was used within contract and purchasing discussions to aid general practitioner understanding of district nursing work and achieve extra funding is described. The paper concludes by questioning the extent to which terminal care is a helpful and accurate representation of what district nursing work entails, and the implications there may be in emphasizing one aspect of care within a purchasing environment.

The influence of exercise-induced plasma volume changes on the interpretation of biochemical parameters used for monitoring exercise, training and sport

A number of studies have demonstrated considerable plasma volume changes during and after exposure to different environmental and physiological conditions. These changes are thought to result from transient fluid shifts into (haemodilution) and out of (haemoconcentration) the intravascular space. If the levels of plasma constituents are to be routinely measured for research purposes or used as indicators of training adaptation or the health of an athlete, then it is important to consider the dynamic nature of plasma volume. Controversy still exists over the relevance of plasma volume interactions with plasma constituent levels, and while some investigators have taken plasma volume shifts into account, others have chosen to ignore these changes. Bouts of acute exercise have been shown to produce a transient haemoconcentration immediately after long distance running, bicycle ergometry and both maximal and submaximal swimming exercise. While these changes are transient, lasting only a few hours, other studies have reported a longer term haemodilution following acute exercise. In addition, endurance training has been shown to cause long term expansion of the plasma volume. It would, therefore, seem important to consider the influence of plasma volume changes on plasma solutes routinely measured for research, and as markers of training adaptation, prior to arriving at conclusions and recommendations based purely on their measured plasma level. To further confound this issue, plasma volume changes are known to be associated with heat acclimatisation, hydration state, physical training and postural changes, all of which may differ from one experiment or exercise bout to the next, and should thus be taken into account.

Changes in performance, muscle metabolites, enzymes and fibre types after short sprint training

In contrast to endurance training, little research has been carried out to investigate the effects of short (< 10 s) sprint training on performance, muscle metabolism and fibre types. Nine fit male subjects performed a mean of 16 outdoor sprint running training sessions over 6 weeks. Distances sprinted were 30-80 m at 90-100% maximum speed and between 20 and 40 sprints were performed in each session. Endurance (maximal oxygen consumption; VO2max), sprint (10 m and 40 m times), sustained sprint (supramaximal treadmill run) and repeated sprint (6 x 40 m sprints, 24 s recovery between each) performance tests were performed before and after training. Muscle biopsy samples (vastus lateralis) were also taken to examine changes in metabolites, enzyme activities and fibre types. After training, significant improvements were seen in 40 m time (P < 0.01), supramaximal treadmill run time (P < 0.05), repeated sprint performance (P < 0.05) and VO2max (P < 0.01). Resting muscle concentrations of ATP and phosphocreatine did not change. Phosphorylase activity increased (P < 0.025), citrate synthase activity decreased (P < 0.01), but no significant changes were recorded in myokinase and phosphofructokinase activities. The proportion of type II muscle fibres increased significantly (P < 0.05). These results demonstrate that 6 weeks of short sprint training can improve endurance, sprint and repeated sprint ability in fit subjects. Increases in the proportion of type II muscle fibres are also possible with this type of training.

The correlation of urodynamic findings with cranial magnetic resonance imaging findings in multiple sclerosis

PURPOSE

To our knowledge there are no studies of the correlation between urinary complaints or urodynamic findings in multiple sclerosis and magnetic resonance imaging (MRI) findings. We investigated the correlation of urodynamic results in multiple sclerosis patients with voiding complaints to the cranial MRI findings. We also sought to correlate urodynamic results in these patients with International Prostate Symptom Scores (IPSS).

MATERIALS AND METHODS

We retrospectively reviewed urodynamic results and cranial MRI findings in 90 multiple sclerosis patients (64 women, 26 men, mean age 44.5 years) with voiding complaints. The most recent urodynamic study and cranial MRI for each patient were reviewed. The interval between the 2 studies and MRI was no more than 6 months. Detrusor contractions were categorized as areflexic, hyporeflexic, hyperreflexic or hyperreflexic with impaired contractility. The presence of impaired compliance or detrusor-external sphincter dyssynergia was recorded. The cranial MRI findings were categorized on the basis of the presence of atrophy or enhancing lesions, total number of lesions and size of largest lesion. The urodynamic and MRI findings were correlated. Of the patients 40 who had urodynamic studies done within the last 6 months completed the IPSS, and severity of cranial MRI findings in these patients was correlated with the IPSS results. In addition, the presence of irritative findings of detrusor hyperreflexia or detrusor hyperreflexia with impaired contractility was correlated with the irritative score (sum of questions 1, 2, 4, 7), and the presence of detrusor-external sphincter dyssynergia was correlated with the obstructive score (sum of questions 3, 5, 6).

RESULTS

There was no correlation between urodynamic category, presence of impaired compliance or presence of detrusor-external sphincter dyssynergia and any of the MRI findings of atrophy or enhancing lesions, total number of lesions or size of the largest lesions. In the patients who completed the IPSS there was no correlation between total number of lesions and IPSS score. There was no correlation between the presence of detrusor-external sphincter dyssynergia and obstructive score on the IPSS or between the presence of detrusor hyperreflexia and irritative score.

CONCLUSIONS

Although patients with multiple sclerosis often are followed closely with urodynamic studies and cranial MRI, there appears to be no correlation between these 2 studies. Symptom scores also do not appear to correlate with urodynamic findings. Therefore, urodynamic studies appear to be warranted and irreplaceable in the evaluation of voiding dysfunction in multiple sclerosis patients.

Can luteal phase serum estradiol concentrations predict karyotypes of spontaneous abortions?

Low serum estradiol concentrations during pregnancy have been associated with spontaneous abortions. A large proportion of abortuses have chromosomal abnormalities. To determine whether serum estradiol during the luteal phase of conception cycles can predict the karyotype of spontaneous abortions, serum estradiol samples were drawn 11 days after embryo transfer from 52 women who subsequently had spontaneous abortions and chromosomal analysis was performed on the products of conception. The frequency of estradiol levels < 100 pg/ml was compared between normal and abnormal karyotypic spontaneous abortions. Chromosomal analyses among 52 spontaneous abortions revealed 14 (27%) to be normal and 38 (73%) abnormal. Among the 38 karyotypic abnormalities 30 were aneuploidy and eight were polyploidy. Serum estradiol levels were < 100 pg/ml in eight women (15%) and > 100 pg/ml in 44 women (85%). The frequencies of estradiol < 100 pg/ml in spontaneous abortions with normal (7%) and abnormal (18%) karyotypes were not significantly different. Thus, serum estradiol cannot predict the karyotype of spontaneous abortions.

Biochemical and ultrastructural indices of muscle damage after a twenty-one kilometre run

Increased serum concentrations of intracellular proteins are generally accepted as good indicators of muscle damage. The mechanism of this damage is, however, poorly understood. Twenty male runners completed a 21 km run in as fast a time as possible. Blood samples were obtained from each subject just prior to, immediately after, and 24 hr after the run. Samples were analysed for haemoglobin, haematocrit, creatine kinase (CK), myoglobin (Mb) and malondialdehyde (MDA) concentrations and corrected for percentage change in plasma volume (PV). Percutaneous muscle biopsies were taken from the lateral gastrocnemius muscle of 6 of the subjects 24 hr before and 24 hr after the run and examined by electron microscopy. Mb levels in the serum increased significantly (p < 0.001) immediately post-exercise, while CK levels increased significantly (p < 0.001) at 24 hours post-exercise. The PV corrected serum MDA levels were very close (p = 0.06) to a significant increase immediately post-exercise. Ultrastructural examination of pre-exercise samples revealed evidence of muscle changes consistent with endurance exercise training, but no further damage was evident at 24 hr post-exercise. It is thus suggested that the increased serum levels of CK and Mb after the 21 km run may be a result of free radical induced cell membrane damage and increased permeability, as evidenced by elevated serum MDA levels, and not due to mechanical muscle damage.

Water budget during ultra-endurance exercise

We examined water gains and water losses in a group of athletes after an ultra-endurance event. Thirteen male triathletes competed in a triathlon consisting of 21 km canoeing, 97 km cycling, and 42 km running. Water loss determinations included sweat rate (940 +/- 163 g.h-1), urine output (41 +/- 38 g.h-1), and respiratory water loss (88 +/- 10 g.h-1). Water gain measurements included water intake (737 +/- 137 g.h-1) and the water content of the food intake (10 +/- 7 g.h-1), and we estimated the water of metabolism for carbohydrate (49 +/- 5 g.h-1) and fat (41 +/- 5 g.h-1) and the water released after glycogen utilization (104 +/- 64 g.h-1). Total water gain averaged 940 +/- 160 g.h-1, while the total water loss averaged 1069 +/- 163 g.h-1. Body weight changed from 69.87 +/- 7.14 kg before the race to 66.65 +/- 6.75 kg after the race (-4.61 +/- 2.94%). The sum of the exogenous water gains and the endogenous water gains (940 g.h-1) replaced almost 90% of the total water loss (1069 g.h-1). The difference (1334 g) represented a loss of about 1.9% of the initial body mass (69.87 kg). The exogenous water gains alone (747 g.h-1) replaced about 70% of the total water loss, and the difference represented a loss of over 4% of the initial body mass. Because of the nature of the endogenous sources of water gain, the total amount of water gain almost replaces the total amount of water loss (difference approximately 12%) even in the presence of a reduction in body mass (> 4%).

Muscle phosphocreatine repletion following single and repeated short sprint efforts

Phosphocreatine (PCr) repletion following either single (1x6 s, n=7) or repeated (5x6 s, departing every 30 s, n=8) maximal short sprint cycling efforts was measured in separate groups of trained subjects. Muscle biopsies (vastus lateralis) were taken pre-exercise before warming up, and then at 10 s, 30 s and 3 min post-exercise. After the 1 x 6 s sprint PCr concentration was respectively, 55% (10 s; P<0.01), 69% (30 s; P<0.01) and 90% (3 min; NS) of the pre-exercise value (mean+/-SD) (81.1+/-7.4 mmol x kg(-1) DM), whereas after the 5x6 s sprints, PCr concentration was, respectively, 27% (10 s; P<0.01), 45% (30 s; P<0.01) and 84% (3 min; P<0.01) of the pre-exercise value (77.1+/-4.9 mmol x kg(-1) DM). PCr concentration was correlated with muscle lactate at 30 s (r=-0.82; P<0.05) and 3 min of recovery (r=-0.94; P<0.01) for the 1x6 s sprint, but not for the 5x6 s sprints. The extent of PCr repletion was significantly greater after the 5x6 s sprints than the 1x6 s sprint between both 10 s and 30 s and 30 s and 3 min, despite lower PCr levels at 10 s, 30 s and 3 min following the 5x6 s sprints. Full repletion of PCr is likely to take longer after repeated sprints than single short sprints because of a greater degree of PCr depletion, such that replenishment must commence from lower PCr levels rather than because of slower rates of repletion.

A controlled trial of circuit weight training on aerobic capacity and myocardial oxygen demand in men after coronary artery bypass surgery

BACKGROUND

Cardiovascular benefits of resistance training in cardiac patients have been suggested but not studied in a randomized, controlled trial of circuit weight training (CWT) without an aerobic exercise component. The purpose of the current study was to examine the effects of 10 weeks of CWT on muscular strength, peak oxygen consumption (peak VO2), and myocardial oxygen demand (mVO2) in men after coronary artery bypass surgery.

METHODS

Twenty-six, post-coronary bypass male subjects (mean 19 months after bypass), aged 60 +/- 8.5 years, were randomly allocated to 10 weeks of CWT at 40 to 60% of maximum voluntary contraction (n = 12) or to a control group (n = 14). Muscular strength was assessed using a modified one repetition maximum technique. Peak VO2 was recorded during symptom-limited treadmill exercise. Rate pressure product, as an indirect measure of mVO2, was measured during isometric, isodynamic, and dynamic exercise.

RESULTS

No ischemic symptoms nor electrocardiographic changes were recorded during testing or training. Strength increased by 18% (P < 0.005) in five out of seven exercises in the training group, but was unchanged in the control group. Training did not improve peak VO2. Rate pressure product during isometric and isodynamic exercise decreased from pre- to post-testing (P < 0.05) but was equivalent to that seen in the control group.

CONCLUSIONS

Moderate intensity CWT is safe and can improve strength in selected low-risk patients after coronary artery bypass surgery. However, it does not significantly increase peak VO2 nor reduce mVO2 during isometric, isodynamic, and dynamic exercise.

Influence of exercise-induced plasma volume changes on the interpretation of biochemical data following high-intensity exercise

OBJECTIVE

To assess the effects that exercise-induced plasma volume changes (PVCs) have on the interpretation of biochemical and hormonal parameters in the blood of athletes after high-intensity exercise. It was hypothesized that two unrelated high-intensity exercise protocols, performed by two separate subject groups each using different exercise modes, would result in similar percentage changes in plasma volume (% delta PV). It was further hypothesized that the % delta PV, measured in both protocols, would comparably influence the interpretation of biochemical variables measured following exercise.

DESIGN

An experimental before-after trial on volunteers was performed. Two different exercise modes employing two different high-intensity acute exercise protocols were investigated. Eight male swimmers performed an interval training session (ITS) consisting of 15 x 100-m freestyle efforts at 95% of their maximal exercise intensity, and eight male runners performed a multistage discontinuous treadmill test (MSD) to volitional exhaustion.

SETTING

The Human Performance Laboratory at the Department of Human Movement at the University of Western Australia.

MAIN OUTCOME MEASURES

Blood samples obtained before, immediately after, and 30, 60, and 120 min during recovery were analyzed for plasma volume changes, urea, uric acid, creatinine, albumin, calcium, iron, transferrin, testosterone, cortisol, and sex hormone-binding globulin (SHBG).

MAIN RESULTS

The ITS and MSD protocols produced similar and significant alterations (p < 0.01) in plasma volume. Both protocols also elicited significant fluctuations (p < 0.01) in the concentration of most of the parameters measured (excluding iron). When albumin, transferrin, testosterone, and SHBG values were adjusted for the significant % delta PV, their concentrations did not change over the experimental period, suggesting that the changes in measured concentration of these parameters may be, in part, due to changes in plasma volume. However, urea, uric acid, creatinine, calcium, and cortisol, when corrected for % delta PVC, still demonstrated significant changes (p < 0.01).

CONCLUSIONS

It is recommended, when sampling biochemical and hormonal parameters in blood following an acute bout of exercise, that corrections for PVCs should be conducted. Apparent changes in blood solutes may reflect PVCs. PVCs should be taken into consideration when interpreting results regardless of exercise protocol and exercise mode performed.

The influence of blood volume changes on leucocyte and lymphocyte subpopulations in elite swimmers following interval training of varying intensities

The effect that exercise induced blood volume (BV) changes may have on the concentrations of leucocyte and lymphocyte subpopulations following exercise is controversial. Eight nationally ranked swimmers undertook 15 x 100 m swimming intervals (ITS) at 70% and 95% of maximal exercise intensity separated by 2 min recovery periods. Venous blood samples were collected prior to exercise (PRE), immediately post exercise (POST) and at 30, 60, 120 and 150-min post exercise. Control samples were taken on a rest day (R). Only the 95% ITS induced a significant (p < 0.01) reduction in PV (-7.3 +/- 1.1%) and BV (-4.0 +/- 0.6%) POST as calculated according to changes in haemoglobin and haematocrit. Total leucocyte and subset numbers (neutrophils, lymphocytes, monocytes), with the exception of eosinophils, increased significantly (p < 0.01) POST following the 95% ITS, and total leucocyte and neutrophils remained elevated (30% and 114% respectively) (p < 0.01) while lymphocytes progressively decreased by 36% (p < 0.01) at 150-min after exercise. The 70% ITS elicited a decrease (30%) (p < 0.01) only in lymphocyte cell numbers at 60 and 120-min post exercise. The 95% ITS induced significant increases (p < 0.01) in most lymphocyte cell subsets [CD19+ (27%); CD16+ (525%); CD16+ CD25+ (58%); CD4+ (48%); CD8+ (65%)] POST, with a significant reduction (32%) (p < 0.01) in the CD4+:CD8+ lymphocyte ratio. Numbers of CD19+; CD16+; CD5+; CD4+ and CD8+ lymphocytes, while not significantly changed POST following the 70% ITS, were significantly depressed (p < 0.01) during the recovery period. No significant changes were seen in leucocyte or lymphocyte subset numbers during R. All measured leucocyte and lymphocyte subset cell numbers at each ITS were corrected for changes in BV, and there were no significant differences between measured or BV corrected values for any of the cell populations at either of the ITS. Results suggest that while high intensity swimming exercise stress caused significant changes in the numbers and proportions of leucocytes, lymphocytes and their sub-classes, BV changes did not contribute significantly to the changes which occurred. The cell changes therefore, were truly representative of cell movements into and out of the peripheral blood circulation.

Comparison of ultrasonographic findings in spontaneous abortions with normal and abnormal karyotypes

To determine whether ultrasonographic findings can predict the karyotype of spontaneous abortions, 137 pregnancies (54 spontaneous, 83 assisted ovulatory cycles) that subsequently aborted and had chromosome analysis performed on the products of conception were studied ultrasonographically. Transvaginal ultrasound was performed using an Acuson 128XP/10 with 7.5 MHz probe. The numbers of empty gestational sacs, small and normal for gestational size, embryonic poles and embryos with documented cardiac activity were calculated. The frequency of each of these findings in pregnancies with normal and abnormal karyotypes was compared. Of the 137 spontaneous abortions, 51 had normal chromosome analyses and 86 had abnormal karyotypes (68 aneuploidies and 18 polyploidies). Ultrasonographic findings in the 51 karyotypically normal pregnancies included 16 (31%) with empty gestational sacs, and 35 (69%) with embryonic poles, of which 24 (69%) were at least 1 week smaller than expected for gestational age and 11 (31%) were the expected size. Embryonic cardiac activity was documented in 22 (63%) of the 35 embryonic poles. Amongst 86 pregnancies with abnormal karyotypes, similar frequencies of ultrasound findings were found: 23 (27%) with empty gestational sacs, 42 (67%) with embryonic poles smaller than expected for gestational age, and 50 (79%) embryos lost after documentation of embryonic cardiac activity. No differences in the frequency of ultrasonographic findings of empty gestational sacs, small embryonic pole and embryonic cardiac activity were observed between karyotypically normal and abnormal spontaneous abortions. Ultrasonographic findings cannot predict the karyotype of spontaneous abortions.

District nursing and the National Health Service reforms: a case for clarification

The challenges to the district nurse's role within the purchaser/provider culture of the National Health Service (NHS) are discussed. The inherent problems of describing community working and the seeming invisibility of what district nurses do is placed in the context of GP fundholding, contracting and commissioning. The paper concludes that district nursing's history of not being involved in policy development and change may lead to it losing aspects of patient care that is well placed and qualified to deliver.