Effects of sample handling,processing, storage,and hemolysis on measurements of key energy metabolites in ovine blood

Four experiments were conducted using mature Suffolk ewes to evaluate the effects of blood sample handling, processing and storage on measurements of the energy metabolites, β-hydroxybutyrate, total cholesterol, glucose, l-lactate, nonesterified fatty acid (NEFA), and triacylglycerol. In experiment 1 the effects of anticoagulants on metabolite measurements and packed-cell volume (PCV) were evaluated. Blood samples (n=12) were collected into one of four evacuated blood-collecting tubes: no anticoagulant (SER; yields serum), and plasma-yielding sodium heparin (HEP), sodium fluoride and potassium oxalate (NAF), and tripotassium ethylenediaminetetraacetic acid (K₃EDTA). Anticoagulant affected (P<0.05) metabolite values, with total cholesterol, triacylglycerol, and l-lactate highest in SER, and glucose highest in HEP; NEFA and β-hydroxybutyrate measurements were not affected (P>0.10) by anticoagulant. In addition, among the plasma-yielding tubes, PCV was highest in HEP and lowest in NAF (P<0.01). Experiment 2 investigated the effects of repetitive freezing-thawing cycles of plasma on metabolite levels. Blood samples (n=20) were collected using NAF tubes, and plasma was stored at −20 °C and thawed in a water bath (21 °C) 0, 1, 2, and 3 times within 18 h after collection. Compared with fresh samples (Thaw 0), by thaw 2, l-lactate increased (P<0.01) 5%, and glucose and total cholesterol decreased (P<0.001) 13 and 4%, respectively. Plasma NEFA increased 10% (P<0.01) between thaws 0 and 1, but returned to fresh levels (Thaw 0) with subsequent freeze-thaw cycles (P<0.05). Plasma β-hydroxybutyrate decreased (P<0.01) between thaws 0 and 1, but there was no further decline with subsequent freeze-thaw cycles (P<0.05). Experiment 3 evaluated the effects of plasma storage temperature (−20 °C versus −80 °C) and length (0–180 days) on metabolite levels in blood samples (n=12) collected in NAF tubes. All plasma metabolites were affected by storage length (day effect, P<0.01) but only total cholesterol values were affected by storage temperature, with values being higher in plasma stored at −20 than −80 °C (P<0.01). Glucose measurements were higher in samples stored at −20 °C for up to 30 days, but were higher thereafter in samples stored at −80 °C (storage length × temperature effect, P<0.01). Experiment 4 evaluated the effects of anticoagulant (SER versus NAF) and whole blood storage (4 °C) for 0, 1, 3, and 7 days on metabolite concentrations. Glucose was higher (P<0.0001) in NAF, possibly the result of the presence of the glycolytic inhibitor, sodium fluoride, whereas l-lactate, NEFA, total cholesterol and β-hydroxybutyrate were higher in SER (P<0.01). Total cholesterol, l-lactate, and NEFA increased, whereas β-hydroxybutyrate decreased with days in storage (P<0.01). Development of hemolysis in the samples artifactually elevated glucose and NEFA values by as much as 41 and 230%, respectively. Attention to proper blood handling, processing, and storage procedures, and avoidance of hemolysis are important in blood clinical analyses and in the proper interpretation of experimental results.     

One-month strawberry-rich anthocyanin supplementation ameliorates cardiovascular risk,oxidative stress markers and platelet activation in humans

Strawberries are an important fruit in the Mediterranean diet because of their high content of essential nutrients and beneficial phytochemicals, which seem to exert beneficial effects in human health. Healthy volunteers were supplemented daily with 500 g of strawberries for 1 month. Plasma lipid profile, circulating and cellular markers of antioxidant status, oxidative stress and platelet function were evaluated at baseline, after 30 days of strawberry consumption and 15 days after the end of the study. A high concentration of vitamin C and anthocyanins was found in the fruits. Strawberry consumption beneficially influenced the lipid profile by significantly reducing total cholesterol, low-density lipoprotein cholesterol and triglycerides levels (−8.78%, −13.72% and −20.80%, respectively; P<.05) compared with baseline period, while high-density lipoprotein cholesterol remained unchanged. Strawberry supplementation also significant decreased serum malondialdehyde, urinary 8-OHdG and isoprostanes levels (−31.40%, −29.67%, −27.90%, respectively; P<.05). All the parameters returned to baseline values after the washout period. A significant increase in plasma total antioxidant capacity measured by both ferric reducing ability of plasma and oxygen radical absorbance capacity assays and vitamin C levels (+24.97%, +41.18%, +41.36%, respectively; P<.05) was observed after strawberry consumption. Moreover, the spontaneous and oxidative hemolysis were significant reduced (−31.7% and −39.03%, respectively; P<.05), compared to the baseline point, which remained stable after the washout period. Finally, strawberry intake significant decrease (P<.05) the number of activated platelets, compared to both baseline and washout values. Strawberries consumption improves plasma lipids profile, biomarkers of antioxidant status, antihemolytic defenses and platelet function in healthy subjects, encouraging further evaluation on a population with higher cardiovascular disease risk.     

Influence of the provision of natural light and straw bales on activity levels and leg health in commercial broiler chickens

The aim of this study was to assess the effect of natural light and straw bales on activity levels and leg health in commercial broiler chickens. Houses containing ∼23 000 broiler chickens were assigned to one of four treatments in a 2 × 2 factorial design. Treatments involved two levels of access to natural light (NL) (present ‘+NL’, or absent ‘−NL’) and two levels of access to straw bales (SB) (present (30/house) ‘+SB’, or absent ‘−SB’). All houses were windowed and artificially lit, and windows were shuttered where appropriate. Treatments were applied in one of the two houses on each of the two farms, and were replicated over four production cycles. Behaviour was observed in 2 to 6 weeks of the cycle. This involved observations of general behaviour and activity, gait scores (0 (perfect) to 5 (unable to walk)) and latency to lie (measured in seconds from encouraging a bird to stand). Production performance and environmental parameters were also measured. Average daytime light intensity and UV levels in the +NL treatment were 85.2 lx and 3.37 μW/cm², respectively, and in the −NL treatment were 11.4 lx and 0 μW/cm², respectively. Litter moisture levels were lower with NL treatment (P < 0.05), but were not affected by SB (P > 0.05). The percentage of time spent lying was significantly reduced by the provision of NL (P < 0.01), but not by SB (P > 0.05). There were three-way interactions between NL, SB and bird age on the percentage of time spent in locomotion (P < 0.05) and idling (P < 0.05). Both treatment factors had inconsistent effects on these parameters across different weeks. Levels of preening, resting and aggressive behaviour were not affected by treatment (P > 0.05). There was an interaction between treatments in average gait scores, with higher scores in the −NL−SB treatment than in all other treatments, and higher in the −NL+SB treatment than in the +NL treatments (P < 0.001). Average latency to lie was significantly higher with NL (P < 0.001) and SB (P < 0.05). We conclude that environmental modifications have the potential to increase activity levels and improve the leg health of commercial broilers. The light environment appears to be particularly important in this respect.     

The effect of systemic Isotretinoin on salivary tissue inhibitors of metalloproteinases 1 and 2 and salivary flow rate in periodontal disease

AimsTo evaluate and compare changes in salivary flow rate and salivary levels of TIMP-1 and TIMP-2 in individuals taking oral Isotretinoin (INN) with those who do not take INN. To assess the variation in TIMP-1 and TIMP-2 as well as salivary flow rate observed at different stages of periodontal disease in comparison to those observed in the case of healthy periodontium.Materials and methodsAn examiner-blind case-control study involving 180 human adults divided into six groups based on their periodontal status. Clinical parameters, including pocket depth, clinical attachment level, and bleeding on probing were measured at six sites per tooth. Whole unstimulated saliva samples were collected from all subjects to evaluate salivary flow rate (SFR). Salivary TIMP-1 and TIMP-2 levels were detected using enzyme-linked immunosorbent assay (ELISA). Data were analyzed using IBM SPSS Software. The Kruskal Wallis test and Mann-Whitney U-tests were employed to verify any significant differences between the groups for all parameters. Multi-regression analysis was performed for each parameter tested in each group. All tests were compared at a significance level of 0.05.ResultsSFR was statistically significantly lower among all INN groups in comparison to the control groups (P < 0.001). TIMP-1 and TIMP-2 were significantly higher in all INN groups in comparison to the control groups, in both gingivitis cases (P = 0.004, P < 0.0001 respectively) and periodontitis cases (P < 0.0001).ConclusionAlthough INN reduces salivary flow rate, the findings of the present study revealed that it had an anti-inflammatory effect in periodontal biomarkers. Specifically, it was positively correlated with an elevation of salivary TIMP-1 and TIMP-2. Hence, INN might be a future additive medication to be further evaluated for the treatment of periodontal diseases.     

Effects of alginate and resistant starch on feeding patterns,behaviour and performance in ad libitum-fed growing pigs

This study assessed the long-term effects of feeding diets containing either a gelling fibre (alginate (ALG)), or a fermentable fibre (resistant starch (RS)), or both, on feeding patterns, behaviour and growth performance of growing pigs fed ad libitum for 12 weeks. The experiment was set up as a 2×2 factorial arrangement: inclusion of ALG (yes or no) and inclusion of RS (yes or no) in the control diet, resulting in four dietary treatments, that is, ALG−RS− (control), ALG+RS−, ALG−RS+, and ALG+RS+. Both ALG and RS were exchanged for pregelatinized potato starch. A total of 240 pigs in 40 pens were used. From all visits to an electronic feeding station, feed intake and detailed feeding patterns were calculated. Apparent total tract digestibility of energy, dry matter (DM), and CP was determined in week 6. Pigs’ postures and behaviours were scored from live observations in weeks 7 and 12. Dietary treatments did not affect final BW and average daily gain (ADG). ALG reduced energy and DM digestibility (P<0.01). Moreover, ALG increased average daily DM intake, and reduced backfat thickness and carcass gain : digestible energy (DE) intake (P<0.05). RS increased feed intake per meal, meal duration (P<0.05) and inter-meal intervals (P=0.05), and reduced the number of meals per day (P<0.01), but did not affect daily DM intake. Moreover, RS reduced energy, DM and CP digestibility (P<0.01). Average daily DE intake was reduced (P<0.05), and gain : DE intake tended to be increased (P=0.07), whereas carcass gain : DE intake was not affected by RS. In week 12, ALG+RS− increased standing and walking, aggressive, feeder-directed, and drinking behaviours compared with ALG+RS+ (ALG×RS interaction, P<0.05), with ALG−RS− and ALG−RS+ in between. No other ALG×RS interactions were found. In conclusion, pigs fed ALG compensated for the reduced dietary DE content by increasing their feed intake, achieving similar DE intake and ADG as control pigs. Backfat thickness and carcass efficiency were reduced in pigs fed ALG, which also showed increased physical activity. Pigs fed RS changed feeding patterns, but did not increase their feed intake. Despite a lower DE intake, pigs fed RS achieved similar ADG as control pigs by increasing efficiency in DE use. This indicates that the energy utilization of RS in pigs with ad libitum access to feed is close to that of enzymatically digestible starch.     

Improvement of cardiometabolic markers after fish oil intervention in young Mexican adults and the role of PPARα L162V and PPARγ2 P12A

Polyunsaturated fatty acids (PUFA) contained in fish oil (FO) are ligands for peroxisome proliferator-activated receptors (PPAR) that may induce changes in cardiometabolic markers. Variation in PPAR genes may influence the beneficial responses linked to FO supplementation in young adults. The study aimed to analyze the effect of FO supplementation on glucose metabolism, circulating lipids and inflammation according to PPARα L162V and PPARγ2 P12A genotypes in young Mexican adults. 191 young, non-smoking subjects between 18 and 40 years were included in a one-arm study. Participants were supplemented with 2.7 g/day of EPA + DHA, during six weeks. Dietary analysis, body composition measurements and indicators for glucose metabolism, circulating lipids, and markers for inflammation were analyzed before and after intervention. An overall decrease in triglycerides (TG) and an increase in HS-ω3 index were observed in all subjects [−4.1 mg/dL, (SD:±51.7), P=.02 and 2.6%, (SD:±1.2), P<.001 respectively]. Mean fasting insulin and glycated hemoglobin (HbA1c%) were significantly decreased in all subjects [−0.547mlU/L, (SD:±10.29), P=.034 and−0.07%, (SD:±0.3), P<.001 respectively], whereas there was no change in body composition, fasting glucose, adiponectin and inflammatory markers. Subjects carrying the minor alleles of PPARα L162V and PPARγ2 P12A had higher responses in reduction of TG and fasting insulin respectively. Interestingly, doses below 2.7 g/day (1.8 g/day) were sufficient to induce a significant reduction in fasting insulin and HbA1c% from baseline (P=.019 and P<.001). The observed responses in triglycerides and fasting insulin in the Mexican population give further evidence of the importance of FO supplementation in young people as an early step towards the prevention of cardiometabolic disease.     

The relationships among the severity of spinal cord injury,motor and somatosensory evoked potentials and spinal cord blood flow

To characterize the changes in axonal function in the motor and somatosensory tracts of the cord after spinal cord injury (SCI) and to correlate these changes with spinal cord blood flow (SCBF), the relationships among the severity of SCI, motor and somatosensory evoked potentials (MEPs and SSEPs) and SCBF were examined. Fifteen rats received a 1.5 g (n = 5), 20 g (n = 5) or 56 g (n = 5) clip compression injury of the cord at C8. SCBF at the injury site was measured by the hydrogen clearance technique 35 min before and 30 min after SCI. Concomitantly MEPs from the cord at T10 (MEP-C) and from the sciatic nerve (MEP-N) and SSEPs were recorded.A linear relationship (r = −0.89, P < 0.002) was found between the severity of SCI and the reduction in SCBF at the injury site. Linear discriminant analysis revealed that both the MEP (P < 0.0001) and SSEP (P < 0.003) were significantly related to the severity of SCI. Furthermore, the amplitude of the MEP (r = 0.65, P < 0.0001) and SSEP (r = 0.58, P < 0.0011) was significantly correlated with the posttraumatic SCBF. Multiple regression revealed that both the severity of cord injury and the degree of posttraumatic ischemia were significantly related to axonal dysfunction after SCI. While the MEP was more sensitive to injury than the SSEP, the SSEP more accurately distinguished between mild and moderate severities of cord injury.Axonal conduction in the motor and somatosensory tracts of the cord was significantly correlated with the reduction in posttraumatic SCBF and, therefore, these data provide quantitative evidence linking posttraumatic ischemia to axonal dysfunction following acute cord injury. Furthermore, this study validates the hypothesis that the combined recording of MEPs and SSEPs is an accurate technique to assess the physiological integrity of the cord after injury.     

Associations of anthropometry and lifestyle factors with HDL subspecies according to apolipoprotein C-III

The presence of apoC-III on HDL impairs HDL's inverse association with coronary heart disease (CHD). Little is known about modifiable factors explaining variation in HDL subspecies defined according to apoC-III. The aim was to investigate cross-sectional associations of anthropometry and lifestyle with HDL subspecies in 3,631 participants from the Diet, Cancer, and Health study originally selected for a case-cohort study (36% women; age 50–65 years) who were all free of CHD. Greater adiposity and less activity were associated with higher HDL containing apoC-III and lower HDL lacking apoC-III. Per each 15 cm higher waist circumference, the level of HDL containing apoC-III was 2.8% higher (95% CI: 0.4, 5.3; P = 0.024) and the level of HDL not containing apoC-III was 4.7% lower (95% CI: −6.0, −3.4; P = <0.0001). Associations for physical activity were most robust to multivariable modeling. Each 20 metabolic equivalent task hours per week reported higher physical activity was associated with 0.9% (95% CI: −1.7, −0.1; P = 0.031) lower HDL containing apoC-III and 0.5% higher (95% CI: 0.1, 1.0; P = 0.029) HDL lacking apoC-III. Lower alcohol consumption was associated with lower HDL lacking apoC-III (percent difference per 15 g/day: 1.58 (95% CI: 0.84, 2.32; P = <0.0001). Adiposity and sedentary lifestyle were associated with a less favorable HDL subspecies profile.     

Effect of dehydroepiandrosterone sulfate on carnitine acetyl transferase activity and l-carnitine levels in oophorectomized rats

Alteration in energy metabolism of postmenopausal women might be related to the reduction of dehydroepiandrosterone sulfate (DHEAS). DHEA and DHEAS decline with age, leveling at their nadir near menopause. DHEA and DHEAS modulate fatty acid metabolism by regulating carnitine acyltransferases and CoA. The purpose of this study was to determine whether dietary supplementation with DHEAS would also increase tissue l-carnitine levels, carnitine acetyltransferase (CAT) activity and mitochondrial respiration in oophorectomized rats. Plasma l-carnitine levels rose following oophorectomy in all groups (P<0.0001). Supplementation with DHEAS was not associated with further elevation of plasma l-carnitine levels, but with increased hepatic total and free l-carnitine (P=0.021 and P<0.0001, respectively) and cardiac total l-carnitine concentrations (P=0.045). In addition, DHEAS supplementation increased both hepatic and cardiac CAT activities (P<0.0001 and P=0.05 respectively). CAT activity positively correlated with the total and free carnitine levels in both liver and heart (r=0.764, r=0.785 and r=0.700, r=0.519, respectively). Liver mitochondrial respiratory control ratio, ADP:O ratio and oxygen uptake were similar in both control and supplemented groups. These results demonstrate that in oophorectomized rats, dietary DHEAS supplementation increases the liver and heart l-carnitine levels and CAT activities. In conclusion, DHEAS may modulate l-carnitine level and CAT activity in estrogen deficient rats. The potential role of DHEAS in the regulation of fatty acid oxidation in postmenopausal women is worthy of investigation.     

Diastolic suction in heart failure: Impact of left ventricular geometry,untwist, and flow mechanics

Aims

Vector flow mapping (VFM) can be used to assess intraventricular hemodynamics quantitatively. This study assessed the magnitude of the suction flow kinetic energy with VFM and investigated the relation between left ventricular (LV) function and geometry in patients with an estimated elevated LV filling pressure.

Materials and methods

We studied 24 subjects with an elevated LV filling pressure (EFP group) and 36 normal subjects (normal group). Suction was defined as flow directed toward the apex during the period from soon after systolic ejection to before mitral inflow. The flow kinetic energy index was quantified as the sum of the product of the blood mass and velocity vector and its magnitude to the peak value was measured.

Key findings

Suction flow was observed in 12 (50%) EFP-group patients and 36 (100%) normal-group subjects. The magnitude of the suction kinetic energy index was significantly smaller in EFP versus normal group (2.7 ± 3.8 vs. 5.7 ± 4.4 g/s/cm², P < 0.01). The EFP-group patients with suction had a smaller LV end-systolic volume (ESV) (P < 0.01), greater ellipsoidal geometry (P < 0.05) and untwisting rate (P < 0.01) than the EFP-group patients without suction. A regression analysis indicated a significant linear relation between the suction kinetic energy index and LVEF (r = 0.43, P = 0.04), ESV (r = − 0.40, P = 0.05), eccentricity index (r = 0.44, P = 0.04), and untwisting rate (r = 0.51, P = 0.04).

Significance

The magnitude of the suction flow kinetic energy index derived from VFM may allow the quantitative assessment of the suction flow, which correlates with LV systolic function, geometry, and untwisting mechanics.     

Quantitative measurement of sympathetic neuropathy in patients with diabetes mellitus

Vasoconstriction occurs in the skin capillary blood flow of the healthy subject when posture changes from supine to standing. Using frequency analysis of the optical photoplethysmograph signal, a statistically significant difference (P<0.01) may be demonstrated between supine and standing positions in the lower frequency band (0.01–0.5 Hz) in the foot of normal subjects. This allowed us to develop a simple index: sympathetic power band change (SPBC). Patients with diabetes mellitus often suffer from degeneration in the sympathetic nervous system. This impairs the normal vasoconstrictor response to standing. We have applied the SPBC ‘blind’ to a group of diabetic patients. Such patients may be divided into three groups according to their SPBC indices: normals with SPBC> 2.6 (group A), intermediates with 2.6 ⩾ SPBC ⩾ 0.26 (group B) and poor with SPBC < 0.26 (group C). All patients with retinopathy were in group C and five out of the six patients with electrophysiologically confirmed peripheral neuropathy were in group C. Frequency analysis of the photoplethysmograph signal has produced an index of sympathetic tone change when subjects move from supine to standing position. The application of this index to patients with diabetes mellitus shows some patients to have sympathetic vascular tone failure.     

Short- and long-term effects of temporary early cow–calf separation or restricted suckling on well-being and performance in zebu cattle

Information on weaning techniques in the tropics is scarce, particularly regarding the long-term effect of temporary early cow–calf separation or restricted suckling. Therefore, we studied the effects of these two handling practices on well-being and performance at 150 days postpartum in fifteen zebu cow–calf pairs randomly assigned to three treatments. Continuous suckling (CS) where calves remained with their dams from birth to weaning; restricted suckling (RS) calves were allowed to suckle 30 min/day from Day 34 until weaning at Day 150 and kept separated the rest of the time; temporary separation (TS) calves were separated for 72 h from their dams from Day 33 to 36 but remained with their dams the rest of the time. Blood samples and behavioral data were collected on Days 32–36 (1st period) and 149–153 (2nd period). In the 1st period, a greater percentage of RS and TS calves were observed close to the fence line (< 10 m) that separated them from their dams (P < 0.0001) and vocalized more than CS calves (P < 0.0001), while in the 2nd period, RS calves had the highest cortisol concentration and vocalization rate (P < 0.05). Similarly, during the 1st period, a greater percentage of RS and TS cows were observed close to the fence line than CS cows (P < 0.0001), with TS cows vocalizing the most (P = 0.001). In the 2nd period, RS cows had greater cortisol concentration than TS (P = 0.037) and CS cows (P = 0.003). More TS and CS cows than RS were observed close to the fence line (P = 0.03 and P = 0.05). On Day 150, TS calves and cows vocalized more than RS and CS animals (P < 0.0001). Before calf–cow separation, 27 out of 45 cows were cycling (CS = 10; RS = 6; TS = 11). After separation, 12 of the remaining 18 cows resumed ovarian activity (CS = 3; RS = 5; TS = 4), and all cows were cycling after estrous synchronization treatment. The pregnancy rate was similar between CS, RS, and TS (60, 53, and 60% respectively). In conclusion, temporary separation increased calf distress response to definitive weaning even four months later, while restricted suckling seemed to reduce it.     

Apple and blackcurrant polyphenol-rich drinks decrease postprandial glucose,insulin and incretin response to a high-carbohydrate meal in healthy men and women

Postprandial glycemic responses to meals are inhibited by polyphenol-rich plant foods. Combinations of polyphenols may be particularly effective through complementary mechanisms. A randomized, controlled, double-blinded cross-over trial was conducted in healthy volunteers to test the hypothesis that apple and blackcurrant polyphenol-rich drinks would reduce postprandial blood glucose concentrations. Secondary outcomes included insulin and glucose-dependent insulinotropic polypeptide (GIP) secretion. Twenty men (mean age 26 y, SD 8) and 5 postmenopausal women (mean age 57 y, SD 3) consumed a placebo drink (CON) and 2 polyphenol-rich drinks containing fruit extracts: either 1200 mg apple polyphenols (AE), or 600 mg apple polyphenols+600 mg blackcurrant anthocyanins (AE+BE), in random order with a starch and sucrose meal. Incremental areas under the curve (iAUC) for plasma glucose concentrations were lower following AE+BE over 0–30 and 0–120 min compared with CON; mean differences (95% CI) −32 mmol/L·min (−41, −22, P<.0005) and −52 mmol/L min (−94, −9, P<.05), respectively. AE significantly reduced iAUC 0–30 min (mean difference −26 mmol/L min, −35, −18, P<.0005) compared with CON, but the difference over 120 min was not significant. Postprandial insulin, C-peptide and GIP concentrations were significantly reduced relative to CON. A dose response inhibition of glucose transport was demonstrated in Caco-2 cells, including total and GLUT-mediated transport, and SGLT1-mediated glucose transport was strongly inhibited at all doses in Xenopus oocytes, following 10 min incubation with 0.125–4 mg apple polyphenols/ml. In conclusion, ingestion of apple and blackcurrant polyphenols decreased postprandial glycemia, which may be partly related to inhibition of intestinal glucose transport.     

Plasma metabolic profile in COPD patients: effects of exercise and endurance training

The study examines plasma metabolic profiles of patients with chronic obstructive pulmonary disease (COPD) to prove whether the disease influences metabolism at rest and after endurance training. This is based on the hypothesis that metabolome levels should reflect impaired skeletal muscle bioenergetics in COPD. The study aims to test this hypothesis by evaluating plasma metabolic profiles in COPD patients before and after 8?weeks of endurance exercise training. We studied blood samples from 18 COPD patients and 12 healthy subjects. Pre- and post-training blood plasma samples at rest and after constant-work rate exercise (CWRE) at 70% of pre-training Watts peak were analyzed by ¹H-nuclear magnetic resonance spectroscopy to assess metabolite profiles. The two groups presented training-induced physiological changes in the VO₂ peak and in blood lactate levels (P?<?0.01 each). Before training, the two groups also showed differences in metabolic profiles at rest (P?<?0.05). Levels of valine (r?=?0.51, P?<?0.01), alanine (r?=?0.45, P?<?0.05) and isoleucine (r?=?0.51, P?<?0.01) were positively associated with body composition (Fat Free Mass Index). While training showed a significant impact on the metabolic profile in healthy subjects (P?<?0.001), with changes in levels of amino acids, creatine, succinate, pyruvate, glucose and lactate (P?<?0.05 each), no equivalent training-induced effects were seen in COPD patients in whom only lactate decreased (P?<?0.05). This study shows that plasma metabolic profiling contributes to the phenotypic characterization of COPD patients.     

Physiological changes induced by pre-adaptation to high altitude

To study the physiological effects of pre-adaptation to high altitude, seven subjects were submitted to acclimatization at 4350 m followed by intermittent acclimation in a low barometric pressure chamber (5000 m to 8500 m). The subjects then spent 25 days in the Himalayas. Ventilatory and cardiac responses were studied during a hypobaric poikilocapnic hypoxic test performed both at rest and during exercise (100 W) in normoxia and in hypoxia (barometric pressure: 589 hPa, altitude: 4500 m). Haemoglobin, erythrocytes, reticulocytes, packed cell volume, 2,3-diphosphoglycerate (2,3-DPG) and erythropoietin (EPO) were measured. All variables were studied before pre-adaptation to high altitude (A), after the acclimatization period (B), after the acclimation period (C) and after the expedition (D). The ventilatory and cardiac responses were characterized by an increased tidal volume in hypoxia (+ 33% during exercise in B,P < 0.05; + 100% at rest and + 33% during exercise in C,P < 0.05) without any change in respiratory frequency, whereas an increased systolic blood pressure was only observed in C during exercise in hypoxia [+23 mmHg (3.07 kPa),P<0.01]. Arterial O2 saturation was higher in hypoxia in C and D, both at rest (+8.2% and +4.7%,P<0.01, respectively), and during exercise (+6.3% and +6.3%,P<0.01, respectively). Erythrocytes, haemoglobin and packed cell volume did not vary significantly. The number of reticulocytes was higher in B (+172%,P<0.05) and in C (+249%,P<0.05). EPO and 2,3-DPG increased only in C (+ 770%,P<0.01 and +23%,P<0.05, respectively). These results showed that a combination of continuous pre-acclimatization on Mont Blanc and intermittent acclimation in the hypobaric chamber triggered efficient pre-adaptation mechanisms allowing climbers to save 1 to 2 weeks of acclimatization on the mountain without clinical inconvenience.     

The effect of gender on left ventricular function immediately after the wingate test

The effect of gender on left ventricular systolic function and exercise haemodynamics in healthy young subjects was studied during 30-s all-out sudden strenuous dynamic exercise. A group of 22 men [19.3 (SD 1) years] 20 women [19.1 (SD 1) years] volunteered to participate in this study. Two-dimensional direct M-mode and Doppler echocardiograph studies were performed with the subject in the sitting position. The Doppler examination of flow was located with continuous-wave, interrogating ascending aorta measurements. The subjects completed the study without showing any electrocardiograph abnormalities. An interaction effect with stroke volume (P < 0.05) was characterized by a decrease in the men and an increase of stroke volume in the women. Cardiac output rose significantly (P < 0.05) up to 14.5 (SD 6) l · min⁻¹) for the men and 12.1 (SD 4) l · min⁻¹ for the women compared to the rest values [5.8 (SD 0.4) and 4.7 (SD 0.5) l · min⁻¹, respectively]. Flow velocity integral and acceleration time differed significantly between the two groups at rest (P < 0.05). During exercise these differences showed an interaction effect (P < 0.05). These results would indicate that normal men and women respond to sudden strenuous exercise by reducing their left ventricular systolic function, with a significantly greater decrease in women (P < 0.05). The gender differences in the haemodynamic responses during the present study, may, as suggested by others, be attributable to differences in energy metabolism. In addition, changes in Doppler parameters of aortic flow, haemodynamics and blood pressure responses during sudden strenuous exercise differed markedly from those seen before with endurance exercise. Accepted: 8 January 1997     

Altered preparatory pelvic control during the sit-to-stance-to-sit movement in people with non-specific low back pain

People with non-specific low back pain (LBP) show hampered performance of dynamic tasks such as sit-to-stance-to-sit movement. However, the underlying mechanisms remain obscure. Therefore, the aim of this study was to assess if proprioceptive impairments influence the performance of the sit-to-stance-to-sit movement.First, the proprioceptive steering of 20 healthy subjects and 106 persons with mild LBP was identified during standing using muscle vibration. Second, five sit-to-stance-to-sit repetitions on a stable support and on foam were performed as fast as possible. Total duration, phase duration, center of pressure (COP) displacement, pelvic and thoracic kinematics were analyzed.People with LBP used less lumbar proprioceptive afference for postural control compared to healthy people (P < 0.0001) and needed more time to perform the five repetitions in both postural conditions (P < 0.05). These time differences were determined in the stance and sit phases (transition phases), but not in the focal movement phases. Moreover, later onsets of anterior pelvic rotation initiation were recorded to start both movement sequences (P < 0.05) and to move from sit-to-stance on foam (P < 0.05).Decreased use of lumbar proprioceptive afference in people with LBP seemed to have a negative influence on the sit-to-stance-to-sit performance and more specifically on the transition phases which demand more control (i.e. sit and stance). Furthermore, slower onsets to initiate the pelvis rotation to move from sit-to-stance illustrate a decrease in pelvic preparatory movement in the LBP group.     

The relationship between disease activity, sleep, psychiatric distress and pain sensitivity in rheumatoid arthritis: a cross-sectional study

Introduction

Cell stimulation leads to the shedding of phosphatidylserine (PS)-rich microparticles (MPs). Because autoimmune diseases (AIDs) are characterized by cell activation, we investigated level of circulating MPs as a possible biomarker in primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA).

Methods

We measured plasma levels of total, platelet and leukocyte MPs by prothrombinase capture assay and flow cytometry in 43 patients with pSS, 20 with SLE and 24 with RA and in 44 healthy controls (HCs). Secretory phospholipase A2 (sPLA2) activity was assessed by fluorometry. Soluble CD40 ligand (sCD40L) and soluble P-selectin (sCD62P), reflecting platelet activation, were measured by ELISA.

Results

Patients with pSS showed increased plasma level of total MPs (mean ± SEM 8.49 ± 1.14 nM PS equivalent (Eq), P < 0.0001), as did patients with RA (7.23 ± 1.05 n PS Eq, P = 0.004) and SLE (7.3 ± 1.25 nM PS Eq, P = 0.0004), as compared with HCs (4.13 ± 0.2 nM PS Eq). Patients with AIDs all showed increased level of platelet MPs (P < 0.0001), but only those with pSS showed increased level of leukocyte MPs (P < 0.0001). Results by capture assay and flow cytometry were correlated. In patients with high disease activity according to extra-glandular complications (pSS), DAS28 (RA) or SLEDAI (SLE) compared with low-activity patients, the MP level was only slightly increased in comparison with those having a low disease activity. Platelet MP level was inversely correlated with anti-DNA antibody level in SLE (r = -0.65; P = 0.003) and serum β2 microglobulin level in pSS (r = -0.37; P < 0.03). The levels of total and platelet MPs were inversely correlated with sPLA2 activity (r = -0.37, P = 0.0007; r = -0.36, P = 0.002, respectively). sCD40L and sCD62P concentrations were significantly higher in pSS than in HC (P ≤ 0.006).

Conclusions

Plasma MP level is elevated in pSS, as well as in SLE and RA, and could be used as a biomarker reflecting systemic cell activation. Level of leukocyte-derived MPs is increased in pSS only. The MP level is low in case of more severe AID, probably because of high secretory phospholipase A2 (sPLA2) activity, which leads to consumption of MPs. Increase of platelet-derived MPs, sCD40L and sCD62P, highlights platelet activation in pSS.     

Effects of Dietary Copper on Nutrient Digestibility,Tissular Copper Deposition and Fur Quality of Growing-Furring Mink (Mustela vison)

The present study investigated the effects of dietary copper (Cu) on growth performance and fur quality in growing-furring minks. One hundred and five standard dark female minks were randomly assigned to seven groups with the following dietary treatments: basal diet with no supplemental Cu (control) and basal diet supplemented with either 6, 12, 24, 48, 96 or 192 mg/kg Cu from copper sulphate, respectively. Our data showed that final body weight (P?=?0.033), daily gain (P?=?0.029) and fat digestibility (P?=?0.0006) responded to increasing levels of Cu. The activity of glutamic-oxalacetic transaminase (GOT) and glutamic-pyruvic transaminase (GPT) in serum increased (linear and quadratic, P?<?0.05) as Cu increased in the diet. Increasing Cu improved total protein (TP) and albumin (ALB) (quadratic, P?<?0.05). The level of ceruloplasmin (CER) responded in a linear (P?<?0.0001) and quadratic (P?<?0.0001) form with increasing level of Cu. Colour intensity of those minks pelted suggested that relatively high levels of supplemental Cu have a beneficial effect on intensifying hair colour of dark mink but did not affect leather thickness. Liver Cu and plasma Cu concentrations of the mink linearly (P?<?0.0001) responded to increasing levels of Cu. Our results indicate that growing-furring mink can efficiently utilize added dietary fat and that Cu plays an important role in the digestion of dietary fat in growing-furring mink, and supplemental dietary Cu in growing-furring mink promotes fat digestion and improve hair colour.