Is low VO2max/kg in obese heart failure patients indicative of cardiac dysfunction?

PURPOSE: Low peak O2 consumption (VO2max/kg) has been widely used as an indirect indicator of poor cardiac fitness, and often guides management of patients with severe heart failure (HF). We hypothesized that it should be as good an indicator of cardiac dysfunction in obese and non-obese HF patients. METHODS: We compared the cardiopulmonary exercise performance and non-invasive hemodynamics of 152 obese (BMI>34 kg.m(-2)) and 173 non-obese (BMI≤32) male HF patients in NYHA classes II and III, with reference to 101 healthy male controls. Their physical and cardiac functional reserves were measured during treadmill exercise testing with standard respiratory gas analyses and CO2 rebreathing to measure cardiac output non-invasively during peak exercise. Data are given as mean ± SD. RESULTS: Obese HF patients with BMI 40.9 ± 7.5 kg·m(-2) (age 56.1 ± 14.0 years, NYHA 2.5 ± 0.5) exercised to acceptable cardiopulmonary limits (peak RER=1.07 ± 0.12), and achieved a mean VO2max/kg of 18.6 ± 5.2 ml·kg(-1)·min(-1), significantly lower than in non-obese HF counterparts (19.9 ± 5.6 ml·kg(-1)·min(-1), P=0.02, age 55.8 ± 10.6 years, BMI 26.6 ± 3.1, NYHA 2.4 ± 0.5, peak RER=1.07 ± 0.09), with both lower than controls (38.5 ± 9.7 ml·kg(-1)·min(-1), P<10(-6)). In contrast, the uncorrected VO2max was higher in obese (2.31 ± 0.69 ml·min(-1)) than non-obese HF patients (1.61 ± 0.49 ml·min(-1), P<10(-6)). When cardiac dysfunction was evaluated directly, peak cardiac power was significantly greater in obese than non-obese HF patients (4.11 ± 1.21 W vs 2.73 ± 0.82 W, P<10(-6)), with both lower than controls (5.42 ± 1.04 W, P<10(-6)). CONCLUSION: These results demonstrate that VO2max/kg is not a generally reliable indicator of cardiac fitness in all patients. Instead, we found that despite having lower VO2max/kg, obese HF patients had stronger hearts capable of generating greater cardiac power than non-obese HF patients of equivalent clinical HF status.

Praziquantel form, dietary application method and dietary inclusion level affect palatability and efficacy against monogenean parasites in yellowtail kingfish.

The bitterness of racemic praziquantel (PZQ) currently constrains its use as an in-feed treatment against monogenean flukes in finfish aquaculture. In an effort to increase the palatability of diets containing racemic PZQ for yellowtail kingfish, the palatability and efficacy of 2 forms of racemic PZQ (powder or powder within microcapsules) against natural infestations of skin and gill flukes were compared using 2 different dietary application methods (incorporated within the pellet mash prior to extrusion or surface-coated after extrusion) at active dietary inclusion levels of 8, 16 and 25 g kg-1 in large (3.5-4 kg) yellowtail kingfish. There was no clear benefit of incorporating PZQ into diets prior to extrusion. PZQ microcapsules improved the palatability of PZQ-containing diets but did not completely mask the bitter flavour. At the lowest active dietary inclusion level of 8 g kg-1, ingestion of the diet containing PZQ microcapsules was equal to the control and significantly better than that containing PZQ powder. At an inclusion level of 16 g kg-1, ingestion of the PZQ microcapsule diet was significantly better than that containing the same inclusion of PZQ powder but significantly lower than the control. Consumption of the diet containing 25 g kg-1 of PZQ microcapsules was poor. All fish consuming medicated feeds had a significant reduction in flukes relative to control fish; however, efficacy data and blood serum analysis suggested that diets containing PZQ microcapsules had lower bioavailability than those containing PZQ powder.

Violation of the Cauchy-Schwarz inequality with matter waves.

The Cauchy-Schwarz (CS) inequality-one of the most widely used and important inequalities in mathematics-can be formulated as an upper bound to the strength of correlations between classically fluctuating quantities. Quantum-mechanical correlations can, however, exceed classical bounds. Here we realize four-wave mixing of atomic matter waves using colliding Bose-Einstein condensates, and demonstrate the violation of a multimode CS inequality for atom number correlations in opposite zones of the collision halo. The correlated atoms have large spatial separations and therefore open new opportunities for extending fundamental quantum-nonlocality tests to ensembles of massive particles.

Prospective randomized trial of laparoscopic (transabdominal preperitoneal-TAPP) versus open (mesh) repair for bilateral and recurrent inguinal hernia: incidence of chronic groin pain and impact on quality of life: results of 10 year follow-up.

PURPOSE: The incidence of chronic groin pain (CGP) and its impact on quality of life (QoL) after hernia repair are not clear with follow-up either being short or retrospective. We present 10-year prospective follow-up of a randomized trial for bilateral and recurrent hernia repair focusing on CGP and its impact on QoL. METHODS: Patients enrolled between 1997 and 2000 were contacted by telephone and asked about the presence of CGP. Those patients with CGP were sent two validated questionnaires: a SF-12v2 Health Survey and a Pain Impact Questionnaire (PIQ-6) (QualityMetric, USA). RESULTS: One hundred and twenty patients were recruited into the original study, and of these, 14 complained of CGP and were sent a PIQ-6 and a SF-12 v2 health survey. Overall, there was a higher incidence of CGP in the laparoscopic group compared with the open group (15 vs. 8 %, ns), but the severity of the pain in the laparoscopic group was less (2 vs. 3.5, p = 0.0558). QoL was significantly reduced in patients with CGP compared with the US norm. The laparoscopic group scored higher in 5 out of 8 of the QoL categories compared with the open group, but this was not significant. Overall age-adjusted scores revealed those under 65 years of age felt they had poorer physical health, and this reduced their QoL compared to normal values. CONCLUSION: CGP following laparoscopic surgery for inguinal hernia repair is less severe than open repair, but this does not translate into a significant improvement in QoLin this study.

Acoustic analog to the dynamical Casimir effect in a Bose-Einstein condensate.

We have modulated the density of a trapped Bose-Einstein condensate by changing the trap stiffness, thereby modulating the speed of sound. We observe the creation of correlated excitations with equal and opposite momenta, and show that for a well-defined modulation frequency, the frequency of the excitations is half that of the trap modulation frequency.

Metastability in spin-polarized Fermi gases.

We study the role of particle transport and evaporation on the phase separation of an ultracold, spin-polarized atomic Fermi gas. We show that the previously observed deformation of the superfluid paired core is a result of evaporative depolarization of the superfluid due to a combination of enhanced evaporation at the center of the trap and the inhibition of spin transport at the normal-superfluid phase boundary. These factors contribute to a nonequilibrium jump in the chemical potentials at the phase boundary. Once formed, the deformed state is highly metastable, persisting for times of up to 2 s.

Direct and indirect effects of simulated calcareous dredge material on eggs and larvae of pink snapper Pagrus auratus.

The direct and indirect effects of a simulated, calcarenite-based dredge material on eggs and larvae of pink snapper Pagrus auratus were assessed. Direct effects were assessed by measuring hatch rate or survival of eggs and pre-feeding larvae, respectively, over a range of concentrations and exposure durations. Exposure of eggs to suspended solid concentrations up to 10 000 mg l(-1) for 24 h did not affect egg buoyancy or hatch rate, despite sediment adherence occurring at the two highest concentrations tested. Newly hatched larvae, whose mouths were still closed, were relatively tolerant of suspended solids, with a 12 h lethal concentration resulting in 50% mortality, LC(50), of 2020 mg l(-1) and a first observable effect concentration of 150 mg l(-1). Once the larvae's mouths opened, tolerance was significantly reduced, with a 12 h LC(50) of 157 mg l(-1) and a first observable effect concentration of 4 mg l(-1). Tolerance of larvae to suspended solids was negatively correlated with suspended solids concentration and exposure time, with exposure durations of

Spontaneous four-wave mixing of de Broglie waves: beyond optics.

We investigate the atom-optical analog of degenerate four-wave mixing by colliding two Bose-Einstein condensates of metastable helium. The momentum distribution of the scattered atoms is measured in three dimensions. A simple analogy with photon phase matching conditions suggests a spherical final distribution. We find, however, that it is an ellipsoid with radii smaller than the initial collision momenta. Numerical and analytical calculations agree with this and reveal the interplay between many-body effects, mean-field interaction, and the anisotropy of the source condensate.

Sub-poissonian number differences in four-wave mixing of matter waves.

We demonstrate sub-Poissonian number differences in four-wave mixing of Bose-Einstein condensates of metastable helium. The collision between two Bose-Einstein condensates produces a scattering halo populated by pairs of atoms of opposing velocities, which we divide into several symmetric zones. We show that the atom number difference for opposing zones has sub-Poissonian noise fluctuations, whereas that of nonopposing zones is well described by shot noise. The atom pairs produced in a dual number state are well adapted to sub-shot-noise interferometry and studies of Einstein-Podolsky-Rosen-type nonlocality tests.

Factors affecting mark quality of alizarin complexone-stained otoliths in juvenile black bream Acanthopagrus butcheri and a prescription for dosage.

The relationships between otolith score, a function of increasing stain visibility, and the ratio of alizarin complexone (mg) to fish biomass (g) for 0.1, 0.6 and 7 g black bream Acanthopagrus butcheri show that acceptable marks are produced in all size classes using a stain-to-biomass ratio of 3.3 mg g(-1) following an immersion period of 24 h.

Deformation of a trapped Fermi gas with unequal spin populations.

The real-space densities of a polarized strongly interacting two-component Fermi gas of 6Li atoms reveal two low-temperature regimes, both with a fully paired core. At the lowest temperatures, the unpolarized core deforms with increasing polarization. Sharp boundaries between the core and the excess unpaired atoms are consistent with a phase separation driven by a first-order phase transition. In contrast, at higher temperatures the core does not deform but remains unpolarized up to a critical polarization. The boundaries are not sharp in this case, indicating a partially polarized shell between the core and the unpaired atoms. The temperature dependence is consistent with a tricritical point in the phase diagram.

Influence of an Escherichia coli-derived phytase on nutrient utilization in broiler starters fed diets containing varying concentrations of phytic acid.

The influence of an Escherichia coli-derived phytase, on nutrient utilization was investigated in broilers fed starter diets containing different concentrations of phytate. The study was conducted as a 3 x 4 factorial arrangement of treatments with 3 concentrations of phytic acid (10.4, 11.8, and 13.6 g/kg; equivalent to 2.8, 3.3, and 3.8 g of phytate P/kg) and phytase (0, 500, 750, and 1,000 FTU/kg). One unit of phytase (FTU) is defined as the quantity of enzyme that releases 1 micromol of inorganic phosphorus/min from 0.00015 mol/L of sodium phytate at pH 5.5 at 37 degrees C. The dietary phytic acid concentrations were manipulated by the inclusion of rice bran. Increasing dietary concentrations of phytic acid resulted in reductions (P < 0.01) in AME. Phytase additions tended to increase AME (P = 0.07), regardless of dietary phytate concentrations. Apparent ileal digestibility coefficients of protein and most amino acids were influenced by phytate (P < 0.05 to 0.001) and phytase (P < 0.001). Phytase improved ileal protein and amino acid digestibility at all phytate concentrations, but the trend in responses to increasing phytase additions was different at different phytate concentrations as shown by significant phytate x phytase interactions (P < 0.01 to 0.001). At the lowest phytate concentration, the ileal digestibility coefficients increased with increasing phytase supplementation. At the medium and high phytate concentrations, the greatest responses were observed at 500 FTU/kg of phytase, with little improvement attributable to further additions. Ileal digestibility of P was lowered (P < 0.01) by increasing phytate concentrations and increased (P < 0.001) with increasing additions of phytase. A significant phytate x phytase interaction (P < 0.05) was also observed, where the improvements in P absorption with added phytase were found to be greater at high phytate concentrations. These data demonstrate the anti-nutritive effects of phytic acid and the potential of microbial phytase to improve energy utilization and the availability of P and amino acids in broilers fed starter diets.

Molecular probe of pairing in the BEC-BCS crossover.

We have used optical molecular spectroscopy to probe the many-body state of paired 6Li atoms near a broad Feshbach resonance. The optical probe projects pairs of atoms onto a vibrational level of an excited molecule. The rate of excitation enables a precise measurement of the closed-channel contribution to the paired state. This contribution is found to be quite small, supporting the concept of universality for the description of broad Feshbach resonances. The dynamics of the excitation provide clear evidence for pairing across the BEC-BCS crossover and into the weakly interacting BCS regime.

Skeletal myopathy in juvenile barramundi, Lates calcarifer (Bloch), cultured in potassium-deficient saline groundwater.

Saline groundwater is being pumped from a number of locations in rural Western Australia to prevent secondary salinity impacting farmland, rural infrastructure and areas with high conservation value. Aquaculture may offset the costs of groundwater pumping, and the suitability of groundwater for finfish aquaculture is being assessed through bioassays. There are marked spatial variations in the ionic composition of saline ground water in Western Australia and this paper describes two bioassays investigating a saline, potassium-deficient water source that resulted in mortalities in juvenile barramundi, Lates calcarifer (Bloch). Histopathological examination revealed severe degeneration and necrosis of skeletal muscles, marked hyperplasia of branchial chloride cells and renal tubular necrosis. Clinical chemistry findings included hypernatraemia and hyperchloridaemia of the blood plasma and lowered muscle potassium levels. It is concluded that the principal cause of death was skeletal myopathy induced by low water potassium levels.

Bright soliton trains of trapped Bose-Einstein condensates.

We variationally determine the dynamics of bright soliton trains composed of harmonically trapped Bose-Einstein condensates with attractive interatomic interactions. In particular, we obtain the interaction potential between two solitons. We also discuss the formation of soliton trains due to the quantum mechanical phase fluctuations of a one-dimensional condensate.

Observation of Fermi pressure in a gas of trapped atoms.

We report the attainment of simultaneous quantum degeneracy in a mixed gas of bosons (lithium-7) and fermions (lithium-6). The Fermi gas has been cooled to a temperature of 0.25 times the Fermi temperature by thermal collisions with the evaporatively cooled bosons. At this temperature, the spatial size of the gas is strongly affected by the Fermi pressure resulting from the Pauli exclusion principle and gives clear experimental evidence for quantum degeneracy.

Nutritional consequences of radiotherapy in early laryngeal carcinoma.

In treating patients with malignant head and neck disease, radiotherapy may compromise their oral intake and, thus, their nutritional status. This study aimed to assess a subgroup of patients who received small field radiotherapy, where their early primary tumour itself would not be expected to affect swallowing and where significant nutritional problems are not traditionally identified. A retrospective analysis of hospital records was undertaken on 61 patients, treated for T1 and T2 N0 laryngeal squamous cell carcinoma with primary radical radiotherapy over a three year period (1993-1995 inclusive). At presentation, 97% had their weight and height recorded, enabling calculation of their body mass index (BMI); 13% presented with a BMI < 20 kg/m2 and the 26% of patients who complained of weight loss at presentation had a mean percentage weight loss of 5.35%. During treatment, 79% of patients had their weight recorded and 49% had a documented mean percentage weight loss of 6.4%. The mean BMI at the end of treatment was significantly lower than at presentation (P = 0.03). These effects occurred despite 80% of patients having at least one dietetic consultation (mean 3.5 consults), and 75% having received high protein/high calorie supplementation. The percentage weight loss during treatment correlated significantly with the gamma-glutamyl transpeptidase (gamma-GT) level at presentation. The biochemical markers, haemoglobin and albumin, were normal in the great majority at presentation and fell non-specifically during treatment in 82% and 56% of patients, respectively. We conclude that significant numbers of patients with early laryngeal malignancy are undernourished at presentation and, despite dietetic support, endure considerable nutritional problems during radiotherapy. Attention to nutritional issues is mandatory even in this group of patients previously considered to be less at risk because of the site and early stage of their disease.

Effects of naloxone, metaclopramide and domperidone on plasma levels of prolactin and LH following suckling in the female rabbit.

Saline, naloxone, domperidone or metaclopramide was injected into lactating rabbits immediately before suckling. Blood samples were taken prior to injection (0 minutes) and then at 15, 30, 45 and 60 minutes after the start of suckling, after which the samples were assayed for plasma prolactin and LH concentrations. In all the does there was a significant increase in prolactin concentration, which was highest 15 minutes after the start of suckling, and which declined exponentially thereafter to levels significantly higher than before suckling. The increase in prolactin concentration was similar in does given saline and naloxone, but it was significantly enhanced in does given metaclopramide; with domperidone the increase was intermediate and not significantly different from that following treatment with saline. In does given saline, domperidone, and metaclopramide plasma LH concentrations declined slowly during the hour after suckling but the concentration was increased significantly in does given naloxone. The inverse correlations between prolactin and LH were low weak and were not significant.

Effects of reducing the remating interval after parturition on the fertility and plasma concentrations of luteinizing hormone, prolactin, oestradiol-17 beta and progesterone in lactating domestic rabbits.

Primiparous crossbred does were remated on Day 1 (n = 15) or 14 (n = 25) post partum and killed on Day 10 post coitum to assess their fertility. Blood samples were taken during the pre- (0-12 h post coitum) and post- (1-10 days post coitum) ovulatory periods and plasma was assayed for luteinizing hormone (LH), prolactin, oestradiol-17 beta and progesterone. Ovulation response was significantly greater (P less than 0.01) and ovulation rate significantly lower (P less than 0.001) in does mated on Day 1 than in those mated on Day 14 post partum. Does failing to ovulate on Day 14 post partum exhibited no preovulatory LH surge and had significantly lower (P less than 0.05) premating concentrations of oestradiol-17 beta and prolactin than those ovulating at this time. No significant differences in hormone concentrations were observed during the preovulatory period between does ovulating on Days 1 and 14 post partum, with the exception of oestradiol-17 beta. Concentrations of this hormone were significantly lower (P less than 0.01) in does mated on Day 1, at 1 h post coitum. We conclude that (i) fertility was affected by the remating interval after parturition, (ii) ovulation failure was associated with an absence of the preovulatory LH surge and a reduction in premating concentrations of oestradiol-17 beta and prolactin and (iii) the lower ovulation rate in early lactation was apparently caused by a reduction in ovarian competence to respond to the gonadotrophic stimulus.