Validity of the SenseWear Armband to assess energy expenditure during intermittent exercise and recovery in rugby union players.

Portable wearable devices that assess energy expenditure during intermittent exercise and recovery would be useful in team sports. Fourteen state-level male rugby union players (mean ± SD: age, 22 ± 4 years; body mass, 88.8 ± 11.2 kg; height, 1.81 ± 0.07 m, body fat, 18 ± 6%) participated in this study. Energy expenditure was measured by the SenseWear Armband (SWA) and validated against indirect calorimetry as the criterion measure during a 42-minute rugby-specific intermittent exercise test and an immediate postexercise 10-minute recovery period. Energy expenditure measurements from indirect calorimetry and the SWA were only moderately correlated during both the exercise test (r = 0.55, ±0.34; mean, ±90% confidence limits) and recovery period (r = 0.58, ±0.33). The SWA estimate of energy expenditure during exercise was unclear, with a mean bias of -1.9% (±5.3%), and during recovery energy expenditure was overestimated, with a mean bias of 17% (±12%) at the mean estimated energy expenditure. Typical error of SWA energy expenditure estimates expressed as a coefficient of variation (±90% confidence interval) was 10% (8-16%) during exercise and 19% (14-30%) during recovery. The SWA did not provide a valid measure of energy expenditure during rugby-specific intermittent exercise or 10-minute postexercise recovery. Further improvements are required in the performance of the SWA before it can be used routinely in intermittent sports and provide worthwhile information in relation to workloads of athletes for sport scientists and coaches.

Modification of agility running technique in reaction to a defender in rugby union.

Three-dimensional kinematic analysis examined agility running technique during pre-planned and reactive performance conditions specific to attacking ball carries in rugby union. The variation to running technique of 8 highly trained rugby union players was compared between agility conditions (pre-planned and reactive) and also agility performance speeds (fast, moderate and slow). Kinematic measures were used to determine the velocity of the centre of mass (COM) in the anteroposterior (running speed) and mediolateral (lateral movement speed) planes. The position of foot-strike and toe-off was also examined for the step prior to the agility side- step (pre-change of direction phase) and then the side-step (change of direction phase). This study demonstrated that less lateral movement speed towards the intended direction change occurred during reactive compared to pre-planned conditions at pre-change of direction (0.08 ± 0.28 m·s(-1) and 0.42 ± 0.25 m·s(-1), respectively) and change of direction foot-strikes (0.25 ± 0.42 m·s(-1) and 0.69 ± 0.43 m·s(-1), respectively). Less lateral movement speed during reactive conditions was associated with greater lateral foot displacement (44.52 ± 6.10% leg length) at the change of direction step compared to pre-planned conditions (41.35 ± 5.85%). Importantly, the anticipation abilities during reactive conditions provided a means to differentiate between speeds of agility performance, with faster performances displaying greater lateral movement speed at the change of direction foot- strike (0.52 ± 0.34 m·s(-1)) compared to moderate (0.20 ± 0.37 m·s(-1)) and slow (-0.08 ± 0.31 m·s(-1)). The changes to running technique during reactive conditions highlight the need to incorporate decision-making in rugby union agility programs. Key pointsChanges to running technique occur when required to make a decision.Fast agility performers use different stepping strategies in reactive conditions.Decision-making must be incorporated in agility training programs.

Small molecule selectin ligand inhibition improves outcome in ischemic acute renal failure.

BACKGROUND: The pathophysiologic and potential therapeutic role of selectins in renal ischemia-reperfusion injury (IRI) is not fully understood, due in part to redundancy in the roles of individual selectins. We hypothesized that blockade of ligands for all three selectins using a novel small molecule (TBC-1269) would improve the course of renal IRI by overcoming redundancy issues. This was investigated in a rat model of renal IRI. METHODS: Rats were treated with TBC-1269 either during or post-IRI. The effects of TBC-1269 were investigated in two models of renal IRI: moderate IRI (30 minutes bilateral renal artery clamping) and severe IRI (45 minutes clamping). The combination of anti-E- and anti-P-selectin antibodies also was investigated in rats subjected to moderate IRI. Renal function, histological injury and mortality were assessed. RESULTS: Rats treated with TBC-1269 during moderate IRI showed significantly reduced serum creatinine (SCr) and tubular necrosis post-ischemia compared to control animals. By contrast, delayed treatment (post-IRI) did not show a reduction in SCr. In rats with severe IRI, TBC-1269 treatment during IRI significantly reduced mortality at 48 hours post-ischemia. Rats with moderate IRI and treated with the combination of anti-E- and anti-P-selectin antibodies showed significantly reduced SCr compared to control rats at 24 hours post-ischemia. CONCLUSIONS: Small molecule selectin ligand inhibition provides a novel and effective approach to attenuate ischemic acute renal failure. Timing of treatment is crucial to success.

Metabolic pathogenesis of cardiorenal disease.

Clinical data have established microalbuminuria/proteinuria as an independent risk factor for the development and progression of renal disease in patients with either diabetes or essential hypertension. Decreased kidney function is associated with increased cardiovascular risk, even at modest reductions in estimated creatinine clearance (to approximately 60 mL/min/1.73 m(2)) or modest elevations in serum creatinine (>1.4 mg/dL). Treatment with angiotensin-converting enzyme inhibitors has been shown in clinical trials to delay or stabilize the rate of progression of renal disease. Reduction in cardiovascular events, such as stroke and myocardial infarction, also has been shown in these high-risk individuals. These effects are dependent and independent of blood pressure control, suggesting a nonhemodynamic effect in blockade of the renin-angiotensin system. In conjunction with other therapeutic interventions, such as dietary modification and control of serum lipids, it appears that for at least a subgroup of patients it is possible to delay or prevent progression of kidney failure. There frequently is a clustering of risk factors in these individuals, including insulin resistance, salt sensitivity, hypertension, and dyslipidemia. The mechanism of the relationship between albuminuria and cardiovascular disease is unclear but may be related to endothelial cell dysfunction. Nonetheless, the presence of microalbuminuria/proteinuria as a marker for cardiovascular disease has important implications for the identification and treatment of individuals at risk.

[Effect of losartan on renal and cardiovascular complications of patients with type 2 diabetes and nephropathy]. / Effekt af losartan på nyre- og kardiovaskulaere komplikationer hos patienter med type 2-diabetes og nefropati.

INTRODUCTION: Diabetic nephropathy is the leading cause of end-stage renal disease. Interruption of the renin-angiotensin system slows the progression of renal disease in type 1 diabetic patients, but similar data are not available for type 2, the most common form of diabetes. We assessed the role of the angiotensin II receptor antagonist, losartan, in type 2 diabetic patients with nephropathy. MATERIAL AND METHODS: One thousand five hundred and thirteen patients were enrolled in this randomised, placebo-controlled study of losartan (50 to 100 mg, once daily) or placebo, in addition to conventional antihypertensive treatment (calcium antagonists, diuretics, alpha- and beta-blockers, centrally acting agents) for a mean of 3.4 years. The primary outcome was the composite of doubling of baseline serum creatinine, end-stage renal disease, or death. Secondary end points included a composite of cardiovascular morbidity and mortality, proteinuria, and the progression rate of renal disease. RESULTS: Baseline demographics in the two groups were similar. Three hundred and twenty-seven patients receiving losartan reached the primary end point, as compared with 359 on placebo (risk reduction = 16 per cent, p = 0.02). Losartan reduced the incidence of doubling of serum creatinine (risk reduction = 25 per cent, p = 0.006) and end-stage renal disease (risk reduction = 28 per cent, p = 0.002), but had no effect on death. Benefits exceeded that attributable to changes in blood pressure. The composite of cardiovascular morbidity and mortality was similar in the two groups, except hospitalisation for heart failure, which was reduced with losartan (risk reduction = 32 per cent, p = 0.005). Proteinuria declined by 35 per cent with losartan (p < 0.001). DISCUSSION: Losartan conferred significant renal benefits in type 2 diabetic patients with nephropathy and was generally well tolerated.

The urgent call of albuminuria/proteinuria. Heeding its significance in early detection of kidney disease.

Microalbuminuria, one of the earliest indicators of kidney injury, could be a harbinger of progressive kidney failure. Similarly, it can also be one of the early signs that a patient at risk for cardiovascular disease is in fact developing the disease. If so, the patient's therapy is failing. Discussion of specific appropriate interventions are beyond the scope of this article. However, publications referred to in this work have recently discussed such interventions in substantial practical detail. Ample evidence shows that factors that are kidney-protective are also cardiovascular-protective.

Proteinuria and cardiovascular disease.

In the last few decades, clinical and experimental data have established microalbuminuria/proteinuria as an independent risk factor for renal disease and for progression of renal disease in patients with diabetes and in those with essential hypertension. Reduction of proteinuria with the use of angiotensin-converting enzyme inhibitors has been shown in clinical trials to delay or stabilize the rate of progression of renal disease. This effect appears to be independent of any effect on blood pressure control. In conjunction with other therapeutic interventions such as dietary modification and control of serum lipids, it appears that for at least a subgroup of patients, it is possible to delay or prevent progression of kidney failure. More recently, evidence has accumulated that establishes microalbuminuria/proteinuria as an independent risk factor for cardiovascular morbidity and mortality even in those without other clinical evidence of kidney disease. There is frequently a clustering of risk factors in these individuals that includes insulin resistance, salt-sensitivity, hypertension, and dyslipidemia. The mechanism of this relationship of proteinuria and cardiovascular disease is unclear, but the presence of proteinuria as a marker for cardiovascular disease has important implications for the identification and treatment of individuals at risk.

Effects of losartan on renal and cardiovascular outcomes in patients with type 2 diabetes and nephropathy.

BACKGROUND: Diabetic nephropathy is the leading cause of end-stage renal disease. Interruption of the renin-angiotensin system slows the progression of renal disease in patients with type 1 diabetes, but similar data are not available for patients with type 2, the most common form of diabetes. We assessed the role of the angiotensin-II-receptor antagonist losartan in patients with type 2 diabetes and nephropathy. METHODS: A total of 1513 patients were enrolled in this randomized, double-blind study comparing losartan (50 to 100 mg once daily) with placebo, both taken in addition to conventional antihypertensive treatment (calcium-channel antagonists, diuretics, alpha-blockers, beta-blockers, and centrally acting agents), for a mean of 3.4 years. The primary outcome was the composite of a doubling of the base-line serum creatinine concentration, end-stage renal disease, or death. Secondary end points included a composite of morbidity and mortality from cardiovascular causes, proteinuria, and the rate of progression of renal disease. RESULTS: A total of 327 patients in the losartan group reached the primary end point, as compared with 359 in the placebo group (risk reduction, 16 percent; P=0.02). Losartan reduced the incidence of a doubling of the serum creatinine concentration (risk reduction, 25 percent; P=0.006) and end-stage renal disease (risk reduction, 28 percent; P=0.002) but had no effect on the rate of death. The benefit exceeded that attributable to changes in blood pressure. The composite of morbidity and mortality from cardiovascular causes was similar in the two groups, although the rate of first hospitalization for heart failure was significantly lower with losartan (risk reduction, 32 percent; P=0.005). The level of proteinuria declined by 35 percent with losartan (P<0.001 for the comparison with placebo). CONCLUSIONS: Losartan conferred significant renal benefits in patients with type 2 diabetes and nephropathy, and it was generally well tolerated.

The national epidemic of chronic kidney disease. What we know and what we can do.

The alarming increase in the incidence and mortality rate of end-stage renal disease (ESRD) over the past several years has prompted concerned physicians to ask why--and to ponder what can be done to ameliorate the situation. This article, the first in a seven-part series coordinated by the National Kidney Foundation, examines the factors surrounding the epidemic of chronic kidney disease and introduces readers to the organization's new clinical practice guidelines developed through its Kidney Disease Outcomes Quality Initiative. These recommendations emphasize early detection and treatment and offer a new avenue of communication between primary care physicians and nephrologists.

A novel IL-18BP ELISA shows elevated serum IL-18BP in sepsis and extensive decrease of free IL-18.

IL-18 binding protein (IL-18BP) is a circulating antagonist of the proinflammatory Th1 cytokine IL-18. It effectively blocks IL-18 by forming a 1:1 high affinity (Kd=400 pM) complex, exhibiting a very low dissociation rate. We have developed a sandwich ELISA for IL-18BPa and determined its limit of detection (62 pg/ml). Interference by IL-18 and related cytokines, as well as cross reactivity with other IL-18BP isoforms (b, c, and d) were determined. Using this ELISA, we measured serum IL-18BPa in large cohorts of healthy individuals and in septic patients. Serum IL-18BPa in healthy individuals was 2.15+/-0.15 ng/ml (range 0.5-7 ng/ml). In sepsis, the level rose to 21.9+/-1.44 ng/ml (range 4-132 ng/ml). Total IL-18 was measured in the same sera by an electrochemiluminescence assay and free IL-18 was calculated based on the mass action law. Total IL-18 was low in healthy individuals (64+/-17 pg/ml) and most of it ( approximately 85%) was in its free form. Total IL-18 and IL-18BPa were both elevated in sepsis patients upon admission (1.5+/-0.4 ng/ml and 28.6+/-4.5 ng/ml, respectively). At these levels, most of the IL-18 is bound to IL-18BPa, however the remaining free IL-18 is still higher than in healthy individuals. We conclude that IL-18BPa considerably inhibits circulating IL-18 in sepsis. Yet, exogenous administration of IL-18BPa may further reduce circulating IL-18 activity.

Node counts in neck dissection: are they useful in outcomes research?

OBJECTIVES: We studied the unilateral nodal yields for procedures reported as standard or modified radical neck dissection (RND) to determine their applicability in outcomes research. METHODS: We analyzed the unilateral nodal yields for all procedures reported as RND for carcinoma of the oral cavity, pharynx, and larynx at our institution from 1985 to 1997 (n = 64, no prior treatment). These included both standard and modified techniques, encompassing levels I through V of the neck. Each side of a bilateral RND was treated as a separate case. This sample was compared with a similar population from the National Cancer Institute's Surveillance, Epidemiology, and End-Results (SEER) registry. Nodal yield was obtained for RND alone and for unspecified neck dissection with primary excision for the same diseases and time period (n = 1499). RESULTS: The mean nodal yield from 64 RND was 30 vs 27 in the SEER data. The standard deviation was 14.7 compared with 17.2 in the SEER data. Values ranged from 7 to 66 nodes whereas the SEER range was from 1 to 97 nodes. Although the SEER data contain nodal yields from regional or selective neck dissection, we corroborate our findings of large variance in nodal yield from our RND sample. CONCLUSIONS: Large variance in nodal yields from RND may have undefined effects on quality of life, cure rate, and survival. Until correlation of nodal yields with outcomes is examined, we cannot know how to relate RND to outcomes.

The CHORUS (Cerivastatin in Heart Outcomes in Renal Disease: Understanding Survival) protocol: a double-blind, placebo-controlled trial in patients with esrd.

The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor (statin)-mediated lowering of serum cholesterol has been associated with a significant reduction in cardiovascular morbidity and mortality. Recent studies suggest that additional non-lipid lowering effects (eg, endothelial stabilization, anti-inflammatory, antithrombogenic) may be important in modulating their effectiveness. Dyslipidemia is common in end-stage renal disease (ESRD), and hemodialysis patients have increased cardiovascular morbidity and mortality. Cerivastatin, a new statin with powerful low-density lipoprotein-cholesterol (LDL-C) lowering capabilities, possesses some unique non-LDL-C-mediated properties that may contribute to a reduction of coronary events in the patient with ESRD. The primary objective of this multicenter multinational study of 1,054 hemodialysis patients is to compare 2 years of treatment with cerivastatin (0.4 mg/d) versus placebo on the composite clinical event rate of myocardial infarction, sudden cardiac death, ischemic stroke, and the need for coronary arterial bypass graft (CABG) or percutaneous transluminal coronary angioplasty (PTCA) procedures in these patients. Changes in lipids, inflammatory proteins including heat stable C-reactive protein (hsCRP), interleukin-6 (IL-6), oncostatin-M, intracellular adhesion molecule-1 (ICAM-1) and monocyte-chemoattractant protein-1 (MCP-1), as well as markers of cardiac muscle pathology, such as troponin I and troponin T, will be assessed in a subset of patients. This study is the first of its kind to assess the effect of a statin on the reduction of cardiovascular morbidity and mortality in an incident hemodialysis population. It will determine whether treatment with cerivastatin can effectively reduce the significant cardiovascular morbidity and mortality.

Recombinant erythropoietin rapidly treats anemia in ischemic acute renal failure.

BACKGROUND: The anemia associated with acute renal failure (ARF) is currently treated with blood transfusions, while the anemia of chronic renal failure is treated with recombinant erythropoietin (EPO). We hypothesized that EPO treatment during ARF could rapidly improve hemoglobin levels and be a useful therapeutic approach. In addition, as tubular epithelial cells have EPO receptors that can mediate proliferation, enhanced recovery of renal function may occur with EPO use. METHODS: An established rat model of ischemic ARF was studied, using either moderate or severe ischemia. EPO was administered in a dose of 500 or 3000 U/kg starting at time of ischemia. Hematocrit (Hct), serum creatinine, reticulocyte count, and mortality rate were measured. RESULTS: EPO treatment led to a rapid and significant increase in Hct at 48 and 72 hours after moderate ischemic renal reperfusion injury (IRI) in EPO (500 U/kg)-treated rats compared with control (saline treated) rats (mean +/- SE; 45.6 +/- 0.3% vs. 42.0 +/- 1.0%, P < 0.01) and (46.6 +/- 0.3 vs. 41.0 +/- 1.0, P < 0.01, N = 3 per group). In severe renal IRI, EPO treatment also led to significantly increased Hct at 48 (40.0 +/- 4.4% vs. 36.8 +/- 0.3%, P < 0.01, N = 3 per group) and 72 hours (43.5 +/- 1.5% vs. 34.7 +/- 2.3%, P < 0.01, N = 3 per group). Higher dose (3000 U/kg) EPO led to a more pronounced Hct increase after severe IRI at 48 hours compared with the 500 U/kg dose (43.5 +/- 0.3 vs. 40.3 +/- 0.3, P < 0.01, N = 3 per group). EPO treatment during moderate or severe renal IRI did not change the course of the renal dysfunction. EPO treatment (N = 19) had a significant protective effect on mortality during severe IRI. In addition, loss of body weight during ARF was not affected by EPO therapy. CONCLUSIONS: Recombinant EPO can rapidly increase Hct and improve mortality during ARF. Human studies are warranted to evaluate the clinical applicability of this important finding.

Pathophysiological role of T lymphocytes in renal ischemia-reperfusion injury in mice.

Mononuclear cell infiltrates are found in human renal ischemia-reperfusion injury (IRI), and peritubular T lymphocytes have been identified in experimental IRI. However, the role of T cells in the pathogenesis of renal IRI is unknown. We hypothesized that T cells are one of the important mediators of renal IRI. To test this hypothesis, we used an established mouse model of renal IRI, and evaluated mice with genetically engineered deficiency of both CD4+ and CD8+ T cells. At 48 h postischemia, CD4/CD8-knockout (KO) mice had marked improvement in renal function compared with control C57BL/6 mice (serum creatinine: 0.7 +/- 0.4 vs. 2.5 +/- 0.3 mg/dl, respectively; P < 0.05). Neutrophil infiltration into postischemic kidney was reduced in CD4/CD8 KO mice, compared with control mice, at both 24 h [polymorphonuclear neutrophils (PMNs)/10 high power fields: 714 +/- 354 vs. 3,514 +/- 660, respectively; P < 0.05] and 48 h (88 +/- 32 vs. 1,979 +/- 209, respectively; P < 0.05). Tubular necrosis score in CD4/CD8 KO mice, compared with control mice, was significantly less at 48 h (0.4 +/- 0.1 vs. 2.4 +/- 0.2, respectively; P < 0.05). Because adhesion between T cells and renal tubular epithelial cells (RTECs) may underlie the pathophysiological role of T cells in renal IRI, we also measured T cell adhesion to primary murine RTECs in vitro. Exposure of RTECs to 2 h of hypoxia followed by 1 h of reoxygenation increased T cell adhesion more than twofold. Phorbol ester treatment, which activates integrins, increased T cell adhesion threefold. These data suggest that T lymphocytes can mediate experimental renal IRI. Moreover, adhesion of infiltrating T cells to renal tubular cells may provide a potential mechanism underlying postischemic tubular dysfunction.

The future of clinical trials in chronic renal disease: outcome of an NIH/FDA/Physician Specialist Conference. Evaluation of Clinical Trial Endpoints in Chronic Renal Disease Study Group.

For people with chronic renal insufficiency, the therapeutic goal is to prevent progression to end-stage renal disease, a serious condition that can only be treated with dialysis and kidney transplantation. Although restriction of dietary protein slows the progression of renal disease somewhat, the principal treatment to slow chronic renal disease is appropriate reduction of blood pressure. Antihypertensive agents, particularly those that produce sustained, long-term reductions in proteinuria, such as angiotensin-converting enzyme inhibitors, not only decrease blood pressure but also preserve renal function. Clinical trials to evaluate these and other drug therapies in renal disease progression have used both "hard end points" (e.g., dialysis, transplantation, death) and intermediate end points of renal disease progression (e.g., doubling of serum creatinine concentration, reductions in proteinuria). Trials that have used hard end points typically recruited patients with advanced renal disease to demonstrate a difference in therapies within a period of 2 to 5 years. However, proteinuria reduction, along with a decrease in the time to doubling of serum creatinine in very early diabetic renal disease, could demonstrate an altered natural history of renal disease. Although hard end points are indicators of a drug's efficacy in reducing cardiovascular events or preserving renal function, they do not assess the impact of a treatment on altering the natural history of early renal disease. For clinical trials of people with all but the most advanced renal disease, use of intermediate end points of renal disease progression is the only practical option for assessment of treatment efficacy and effectiveness. Given the available data on proteinuria reduction and doubling of serum creatinine from clinical trials, these end points, taken together, appear to provide an acceptable means of assessing a treatment's impact on slowing renal disease progression.

Xanthoma of the temporal bone: a unique case of this rare condition.

Xanthoma of the temporal bone is extremely rare; we describe only the fourteenth reported case. Our case is further remarkable because it is the first report of such an occurrence in a patient with familial type III hyperlipoproteinemia. Moreover, while otalgia, infection, hearing loss, and tinnitus were the most common initial symptoms in the previous 13 cases, our patient reported only diplopia, vertigo, and unstable gait. The patient underwent a simple mastoidectomy and debulking, and his diplopia, vertigo, and unstable gait resolved.

Pharmacokinetics and blood pressure response of losartan in end-stage renal disease.

BACKGROUND: Losartan is a selective angiotensin AT1 receptor antagonist currently employed in the management of essential hypertension. This compound is in common use in populations with renal failure and end-stage renal disease (ESRD). OBJECTIVE: To investigate the pharmacokinetics and pharmacodynamics of losartan in patients with ESRD in order to establish administration guidelines. METHODS: Patients were administered losartan 100 mg/day for 7 days, and after the seventh and final dose pharmacokinetic parameters were determined for both losartan and its active metabolite E-3174. During the study, the haemodialytic clearances of losartan and E-3174 were measured during a standard 4-hour dialysis session. Neurohumoral and biochemical changes were assessed during losartan administration. RESULTS: The pharmacokinetics of losartan and E-3174 in haemodialysis patients did not alter to a clinically significant level. Losartan administration was accompanied by a decline in plasma aldosterone level as well as by an increase in plasma renin activity. Losartan administration resulted in a decline in plasma uric acid level, despite the fact that the study participants had no residual renal function. Losartan and E-3174 were not dialysable. CONCLUSIONS: The pharmacokinetics of losartan and E-3174 are minimally altered in ESRD; thus, dosage adjustment is not required in the presence of advanced dialysis-dependent renal failure. In addition, postdialysis supplementation is not required for losartan because of the negligible dialysability of losartan and E-3174.