Is long-term exercise intervention effective to improve cardiac autonomic control during exercise in subjects with multiple sclerosis? A randomized controlled trial

BACKGROUND

Patients with multiple sclerosis (MS) suffer from a disturbed cardiac autonomic control during exercise (based on heart rate (HR) changes during exercise), which affects exercise tolerance. Whether long-term exercise intervention improves HR changes during exercise in patients with MS remains unknown.

AIM

To examine whether long-term exercise intervention improves HR changes during exercise, and correlates with improvements in exercise tolerance, in patients with MS.

DESIGN

Randomized controlled trial.

SETTING

University rehabilitation facility.

POPULATION

Twenty-three patients with MS were randomly assigned to six months of follow-up (n=9) or six months of exercise training (n=14, 54-60 training sessions).

METHODS

At baseline and after three and six months of follow-up, exercise-onset (first 20 and 60 seconds) and -offset (1-minute recovery) heart rate (HR) change was determined during a constant-load exercise test: these data reflect the (re)activation of the (para)sympathetic nervous system at initiation and/or cessation of exercise. Blood lactate, HR, oxygen uptake, expiratory volume and ratings of perceived exertion (RPE) were assessed during exercise as indicators for exercise tolerance.

RESULTS

Exercise-onset and -offset HR and exercise tolerance did not change during follow-up in the control group (P>0.05). In the exercise intervention group, blood lactate content and RPE during exercise decreased significantly (group/time interaction effect P<0.05), but exercise-onset and -offset HR did not change (P>0.05). No correlations were found between changes in exercise tolerance and changes in exercise-onset and -offset HR (P>0.05).

CONCLUSION

In patients with MS, long-term exercise intervention does not improve HR changes during exercise, despite improvements in exercise tolerance, indicating that cardiac autonomic control during exercise is not easily improved by exercise intervention in patients with MS.

CLINICAL REHABILITATION IMPACT

This study indicates that patients with MS suffer from a disturbed cardiac autonomic control during exercise, based on heart rate changes, which is not easily remediated by exercise intervention. Because a disturbed cardiac autonomic control is related to exercise intolerance in MS, it should further be explored how to remediate this anomaly through exercise intervention or other approaches.

Measurement of the inclusive electron neutrino charged current cross section on carbon with the T2K near detector

The T2K off-axis near detector ND280 is used to make the first differential cross-section measurements of electron neutrino charged current interactions at energies ∼1  GeV as a function of electron momentum, electron scattering angle, and four-momentum transfer of the interaction. The total flux-averaged ν(e) charged current cross section on carbon is measured to be ⟨σ⟩(ϕ)=1.11±0.10(stat)±0.18(syst)×10⁻³⁸ cm²/nucleon. The differential and total cross-section measurements agree with the predictions of two leading neutrino interaction generators, NEUT and GENIE. The NEUT prediction is 1.23×10⁻³⁸ cm²/nucleon and the GENIE prediction is 1.08×10⁻³⁸ cm²/nucleon. The total ν(e) charged current cross-section result is also in agreement with data from the Gargamelle experiment.

Exercise tolerance in obese vs. lean adolescents: a systematic review and meta-analysis

To prescribe feasible and medically safe exercise interventions for obese adolescents, it remains to be determined whether exercise tolerance is altered and whether anomalous cardiopulmonary responses during maximal exercise testing are present. Studies that examined cardiopulmonary responses to maximal exercise testing in obese adolescents were searched: cardiopulmonary exercise tests with respiratory gas exchange measurements of peak oxygen uptake (VO2peak) were performed and comparisons between obese and lean adolescents were made. Study quality was assessed using a standardized item list. By meta-analyses VO2peak, peak cycling power output (Wpeak) and peak heart rate (HRpeak) were compared between groups. Nine articles were selected (333 obese vs. 145 lean adolescents). VO2peak (L min(-1)), HRpeak and Wpeak were not different between groups (P ≥ 0.10), while a trend was found for a reduced VO2peak (mL min(-1) kg(-1) lean tissue mass) (P=0.07) in obese vs. lean adolescents. It remained uncertain whether anomalous cardiopulmonary responses occur during maximal exercise testing in obese adolescents. In conclusion, a trend was found for lowered VO2peak (mL min(-1)kg(-1) lean tissue mass) in obese vs. lean adolescents. Whether cardiopulmonary anomalies during maximal exercise testing would occur in obese adolescents remains uncertain. Studies are therefore warranted to examine the cardiopulmonary response during maximal exercise testing in obese adolescents.

Precise measurement of the neutrino mixing parameter θ23 from muon neutrino disappearance in an off-axis beam

New data from the T2K neutrino oscillation experiment produce the most precise measurement of the neutrino mixing parameter θ23. Using an off-axis neutrino beam with a peak energy of 0.6 GeV and a data set corresponding to 6.57×10(20) protons on target, T2K has fit the energy-dependent νμ oscillation probability to determine oscillation parameters. The 68% confidence limit on sin(2)(θ23) is 0.514(-0.056)(+0.055) (0.511±0.055), assuming normal (inverted) mass hierarchy. The best-fit mass-squared splitting for normal hierarchy is Δm32(2)=(2.51±0.10)×10(-3)  eV(2)/c(4) (inverted hierarchy: Δm13(2)=(2.48±0.10)×10(-3)  eV(2)/c(4)). Adding a model of multinucleon interactions that affect neutrino energy reconstruction is found to produce only small biases in neutrino oscillation parameter extraction at current levels of statistical uncertainty.

Observation of electron neutrino appearance in a muon neutrino beam

The T2K experiment has observed electron neutrino appearance in a muon neutrino beam produced 295 km from the Super-Kamiokande detector with a peak energy of 0.6 GeV. A total of 28 electron neutrino events were detected with an energy distribution consistent with an appearance signal, corresponding to a significance of 7.3σ when compared to 4.92±0.55 expected background events. In the Pontecorvo-Maki-Nakagawa-Sakata mixing model, the electron neutrino appearance signal depends on several parameters including three mixing angles θ12, θ23, θ13, a mass difference Δm(32)(2) and a CP violating phase δ(CP). In this neutrino oscillation scenario, assuming |Δm(32)(2)|=2.4×10(-3)  eV(2), sin(2)θ(23)=0.5, and Δm322>0 (Δm(32)(2)<0), a best-fit value of sin(2)2θ(13)=0.140(-0.032)(+0.038) (0.170(-0.037)(+0.045)) is obtained at δ(CP)=0. When combining the result with the current best knowledge of oscillation parameters including the world average value of θ(13) from reactor experiments, some values of δ(CP) are disfavored at the 90% C.L.

Measurement of neutrino oscillation parameters from muon neutrino disappearance with an off-axis beam

The T2K Collaboration reports a precision measurement of muon neutrino disappearance with an off-axis neutrino beam with a peak energy of 0.6 GeV. Near detector measurements are used to constrain the neutrino flux and cross section parameters. The Super-Kamiokande far detector, which is 295 km downstream of the neutrino production target, collected data corresponding to 3.01×10(20) protons on target. In the absence of neutrino oscillations, 205±17 (syst) events are expected to be detected while only 58 muon neutrino event candidates are observed. A fit to the neutrino rate and energy spectrum, assuming three neutrino flavors and normal mass hierarchy yields a best-fit mixing angle sin2(θ23)=0.514±0.082 and mass splitting |Δm(32)(2)|=2.44(-0.15)(+0.17)×10(-3) eV2/c4. Our result corresponds to the maximal oscillation disappearance probability.

152 EVALUATION OF POMEGRANATE (PUNICA GRANATUM) AS REPLICATION INHIBITOR OF BoHV-1 COLORADO STRAIN DURING IN VITRO MATURATION OF INFECTED BOVINE OOCYTES

The widespread use of biotechnologies in animal breeding in Brazil has enabled greater control over the transmission of pathogens. Nevertheless, disease transmission continues to be a significant concern and justifies the search for better control agents. The objective of this study was to evaluate whether the detrimental effects of the experimental infection of oocytes with BoHV-1 (Colorado strain, 108 TCID 50 mL–1) during in vitro maturation (24 h) could be reduced by the viral inhibitor ethanolic extract of Punica granatum (PG). Cattle ovaries were obtained from a local slaughterhouse (unknown breed), and transported to the laboratory. Cumulus–oocyte complexes (COC) were aspirated from follicles and allocated into four groups, which were exposed to: 10 µL of sterile physiological solution (G1 [control], n = 125); 10 µL of PG extract in 0.01% sterile saline solution (G2, n = 149); 10 µL of BoHV-1 virus (G3, n = 151); or 10 µL of PG extract in 0.01% and 10 µL of BoHV-1 virus (G4, n = 144). All groups were matured in 100 mL of IVM for 24 h at 37.5°C, 5% CO2 in air. After in vitro maturation, we evaluated COC expansion and presence of a polar body by optical microscope, and viral replication by titration (Reed and Muench test) after 72 h co-culture with Madin-Darby bovine kidney (MDBK) cells. Differences among groups in maturation rates were compared by chi-square test, and in titration by t-test. The G1, G2, and G4 showed steady expansion of the cumulus cells and ooplasm with uniform appearance. The G3 did not show expansion of the cumulus cells and ooplasma showed degenerative appearance. The maturation rates were as follows: G1 52% (65/125); G2 45.63% (68/149); G3 27.81% (42/151); G4 41.66% (60/144). We used the χ2 test (P ≤ 0.05) for the rate of maturation and the t-test (P ≤ 0.05) for the titration data. A reduction (P ≤ 0.05) in maturation rate was observed in G3, when compared to the G1 [control]. Oocytes exposed to BoHV-1 virus and matured in the presence of PG extract (G4) had lower (P ≤ 0.05) rates of viral replication than those matured in the absence of PG (G3). These results support the conclusion that PG extract reduces the viral rate of replication without interfering in oocyte maturation, and may be an alternative to sanitary control protocols.

Prolonged exercise training increases intramuscular lipid content and perilipin 2 expression in type I muscle fibers of patients with type 2 diabetes

The aim of the present study was to investigate changes in intramuscular triglyceride (IMTG) content and perilipin 2 expression in skeletal muscle tissue following 6 mo of endurance-type exercise training in type 2 diabetes patients. Ten obese male type 2 diabetes patients (age 62 ± 1 yr, body mass index BMI 31 ± 1 kg/m²) completed three exercise sessions/week consisting of 40 min of continuous endurance-type exercise at 75% V(O₂ peak) for a period of 6 mo. Muscle biopsies collected at baseline and after 2 and 6 mo of intervention were analyzed for IMTG content and perilipin 2 expression using fiber type-specific immunofluorescence microscopy. Endurance-type exercise training reduced trunk body fat by 6 ± 2% and increased whole body oxygen uptake capacity by 13 ± 7% (P < 0.05). IMTG content increased twofold in response to the 6 mo of exercise training in both type I and type II muscle fibers (P < 0.05). A threefold increase in perilipin 2 expression was observed from baseline to 2 and 6 mo of intervention in the type I muscle fibers only (1.1 ± 0.3, 3.4 ± 0.6, and 3.6 ± 0.6% of fibers stained, respectively, P < 0.05). Exercise training induced a 1.6-fold increase in mitochondrial content after 6 mo of training in both type I and type II muscle fibers (P < 0.05). In conclusion, this is the first study to report that prolonged endurance-type exercise training increases the expression of perilipin 2 alongside increases in IMTG content in a type I muscle fiber-type specific manner in type 2 diabetes patients.

Suppressed increase in blood endothelial progenitor cell content as result of single exhaustive exercise bout in male revascularised coronary artery disease patients

Endothelial progenitor cells (EPCs) significantly affect endothelial repair capacity and, hence, cardiovascular disease incidence. In healthy subjects, blood EPC content increases significantly as result of a single maximal exercise test, hereby stimulating endothelial repair capacity. It remains to be shown whether a single exercise positively affects blood EPCs in revascularised coronary artery disease (CAD) patients. From male revascularised CAD patients (n = 60) and healthy volunteers (n = 25) blood samples were collected before and immediately after a maximal cardiopulmonary exercise test. Blood samples were analyzed by optimised flow cytometry methodology for EPC content (CD34+, CD34+ CD133+, CD34+VEGFR2+, CD34+CD133+VEGFR2+, and CD34+CD133-VEGFR2+ cells) and compared between groups. CFU-Hill colonies were additionally assessed. As a result of a maximal exercise test, blood CD34+, CD34+VEGFR2+ (all EPCs), CD34+CD133+, and CD34+ CD133-VEGFR2+ (mature EPCs) cells increased significantly in CAD patients (p < 0.05), but less than in healthy subjects (p < 0.05, and p = 0.06 for CD34+VEGFR2+). CD34+CD133+VEGFR2+ cells (immature EPCs) did not change as result of exercise (p > 0.05). No changes in CFU-Hill colonies as result of exercise were observed. This study shows that blood mature EPCs (CD34+CD133-VEGFR2+) increase significantly as result of a single exercise bout in revascularised CAD patients, but with smaller magnitude compared to healthy subjects. Blood immature EPCs (CD34+CD133+VEGFR2+) did not change significantly as result of exercise.

Indication of electron neutrino appearance from an accelerator-produced off-axis muon neutrino beam

The T2K experiment observes indications of ν(μ) → ν(e) appearance in data accumulated with 1.43×10(20) protons on target. Six events pass all selection criteria at the far detector. In a three-flavor neutrino oscillation scenario with |Δm(23)(2)| = 2.4×10(-3)  eV(2), sin(2)2θ(23) = 1 and sin(2)2θ(13) = 0, the expected number of such events is 1.5±0.3(syst). Under this hypothesis, the probability to observe six or more candidate events is 7×10(-3), equivalent to 2.5σ significance. At 90% C.L., the data are consistent with 0.03(0.04) < sin(2)2θ(13) < 0.28(0.34) for δ(CP) = 0 and a normal (inverted) hierarchy.

Square-wave retarder for polarization computer-generated holography

An etched calcite square-wave retarder is designed, fabricated, and demonstrated as an illuminator for an interlaced polarization computer-generated hologram (PCGH). The calcite square-wave retarder enables alternating columns of orthogonal linear polarizations to illuminate the interlaced PCGH. Together, these components produce a speckled, tangentially polarized PCGH diffraction pattern with a measured ratio of polarization of 84% and a degree of linear polarization of 0.81. An experimental alignment tolerance analysis is also reported.