Efficacy of heat-killed <Emphasis Type="Italic">Lactococcus lactis</Emphasis> JCM 5805 on immunity and fatigue during consecutive high intensity exercise in male athletes: a randomized,placebo-controlled,double-blinded trial

Background

Lactococcus lactis JCM 5805 (LC-Plasma) is a unique lactic acid bacteria (LAB) which activates plasmacytoid dendritic cells (pDC). We aimed to evaluate the effect of LC-Plasma on dendritic cell (DC) activity and subjective indices of upper respiratory tract infections (URTI) and fatigue in athletes under high intensity exercise.

Methods

We conducted a randomized, placebo-controlled, double-blinded trial. Fifty-one male subjects belonging to a university sports club were randomized into placebo (n?=?25) and LC-Plasma (n?=?26) groups. Individuals ingested placebo capsules containing cornstarch or LC-Plasma capsules containing 100 billion cells of heat-killed LC-Plasma per day for 13 days. During the intervention period, subjects performed high intensity exercise according to their sports club training regime. Blood and saliva sampling were obtained at days 1 and 14, and physical conditions were recorded in a diary. We investigated expression of maturation markers on DCs, muscle damage and stress markers and used student’s t test adjusted by Bonferoni’s method for multiple comparison between groups. These data were presented as mean?±?SD. We also investigated cumulative days of symptoms regarding infections and fatigue and used Chi-square test for comparison between groups. These data were presented as cumulative number.

Results

CD86 as maturation marker on pDC was significantly increased in the LC-Plasma group at day 14 (Placebo: 296?±?70 vs. LC-Plasma: 365?±?115; Mean Fluorescent Intensity; p?=?0.013). Cumulative days of URTI were significantly lower in the LC-Plasma group (Placebo: URTI positive 56, URTI negative 256 vs. LC-Plasma: URTI positive 39, URTI negative 299; days; p?=?0.028) and symptoms like sneeze or running nose were significantly lower in the LC-Plasma group (Placebo: Symptom positive 52, Symptom negative 258, vs. LC-Plasma: Symptom positive 36, Symptom negative 301; days; p?=?0.032). Moreover, the cumulative days of fatigue were significantly fewer in the LC-Plasma group (Placebo: Symptom positive 128, Symptom negative 182, vs. LC-Plasma: Symptom positive 110, Symptom negative 225; days; p?=?0.032). Markers of muscle damage and stress markers were not significantly different between groups.

Conclusion

We consider that heat-killed LC-Plasma supplementation relieves morbidity and symptoms of URTI via activation of pDC and decreases fatigue accumulation during consecutive high intensity exercise in athletes. However, LC-Plasma ingestion did not affect markers of muscle damage and stress.

Trial registration

UMIN-CTR, UMIN000020372. Registered 28 December 2015.

     

Nutrient Supply to Seawater from Steelmaking Slag: The Coupled Effect of Gluconic Acid Usage and Slag Carbonation

Metallurgical and Materials Transactions B - Vanishing of seaweeds in coastal areas has become a serious environmental problem. Part of the reason is nutrient deficiency in seawater, especially...     

Hamilton–Jacobi–Bellman Quasi-Variational Inequality arising in an environmental problem and its numerical discretization

A Hamilton–Jacobi–Bellman Quasi-Variational Inequality (HJBQVI) for a river environmental restoration problem with wise-use of sediment is formulated and its mathematical properties are analyzed. A finite difference scheme with a penalization technique is then established for solving the HJBQVI. The scheme is free from any iterative solvers and is unconditionally stable and convergent in the viscosity sense under certain conditions. A demonstrative application example of the HJBQVI is finally presented.     

Electrical Conduction at the Interface between Insulating van der Waals Materials

Emergent properties of 2D materials attract considerable interest in condensed matter physics and materials science due to their distinguished features that are missing in their bulk counterparts. A mainstream in this research field is to broaden the scope of material to expand the horizons of the research area, while developing functional interfaces between different 2D materials is another indispensable research direction. Here, the emergence of electrical conduction at the interface between insulating 2D materials is demonstrated. A new class of van der Waals heterostructures consisting of two sets of insulating transition‐metal dichalcogenides, group‐VI WSe₂ and group‐IV TMSe₂ (TM = Zr, Hf), is developed via molecular‐beam epitaxy, and it is found that those heterostructures are highly conducting although all the constituent materials are highly insulating. The WSe₂/ZrSe₂ interface exhibits more conducting behavior than the WSe₂/HfSe₂ interface, which can be understood by considering the band alignments between constituent materials. Moreover, by increasing Se flux during heterostructure fabrication, the WSe₂/ZrSe₂ interface becomes more conducting, reaching nearly metallic behavior. Further improvement of the crystalline quality as well as exploring different material combinations are expected to lead to metallic conduction, providing a novel functionality emerging at van der Waals heterostructures.     

Transient shift of local oxygen potential in nonstoichiometric oxides upon application of mechanical stress

Effect of mechanical stress on defect equilibrium was studied with an oxygen nonstoichiometric compound, La_0.6Sr_0.4Co_0.2Fe_0.8O_3-δ . In general, formation of oxygen vacancy in an oxide causes lattice expansion, which leads to stabilization of oxygen vacancy in the material under a tensile stress, and vice versa. Oxygen vacancy concentration is thus expected to increase under a tensile stress and decrease under a compressive stress. However, the change in defect concentration would not proceed spontaneously so that the material just after the application of stress would stay out of equilibrium. On this assumption, attempts were made to detect the shift of oxygen potential under stress using a potentiometric method. A ball-shaped yttria stabilized zirconia (YSZ) of 9.5 mm in diameter was utilized as an oxygen potential sensor as well as a pushing rod which was pressed onto the sample surface. In the measurements at 873 K to 1073 K, a clear shift of emf to the negative direction was observed depending on the magnitude of load and loading speed. It was followed by a relaxation to the initial value under the stress. On unloading operation, the shift of emf to the positive direction was observed. Those behaviors were well explained by the assumption that the oxygen vacancy concentration varies under mechanical stress.     

Striking effects of cobalt (III) nuclearity in fused salphen complexes on their electroconductivity and thin film transistor activity

Dinuclear and trinuclear cobalt (III) complexes were prepared using fused salphen ligands that have the same number of benzene rings along the major axis of the molecules. The two compounds were used as organic thin film formed on a glass or a SiO₂/n-Si substrate for investigating electronic conductivity and transistor characteristics, respectively. The conductivity of di- and trinuclear complexes were 8.5 × 10⁻⁵ and 5.8 × 10⁻³ S cm⁻¹, meaning that the increment of the nuclearity from two to three resulted in multiplication of 70 times. The thin film of the trinuclear complex showed a faint transistor activity, where the thin film act as n-type semiconductor. In contrast, the dinuclear complex did not afford a detectable response to the gate voltage.     

Neutrophil Elastase Deficiency Ameliorates Myocardial Injury Post Myocardial Infarction in Mice

Neutrophils are recruited into the heart at an early stage following a myocardial infarction (MI). These secrete several proteases, one of them being neutrophil elastase (NE), which promotes inflammatory responses in several disease models. It has been shown that there is an increase in NE activity in patients with MI; however, the role of NE in MI remains unclear. Therefore, the present study aimed to investigate the role of NE in the pathogenesis of MI in mice. NE expression peaked on day 1 in the infarcted hearts. In addition, NE deficiency improved survival and cardiac function post-MI, limiting fibrosis in the noninfarcted myocardium. Sivelestat, an NE inhibitor, also improved survival and cardiac function post-MI. Flow cytometric analysis showed that the numbers of heart-infiltrating neutrophils and inflammatory macrophages (CD11b⁺F4/80⁺CD206^low cells) were significantly lower in NE-deficient mice than in wild-type (WT) mice. At the border zone between intact and necrotic areas, the number of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL)-positive apoptotic cells was lower in NE-deficient mice than in WT mice. Western blot analyses revealed that the expression levels of insulin receptor substrate 1 and phosphorylation of Akt were significantly upregulated in NE-knockout mouse hearts, indicating that NE deficiency might improve cardiac survival by upregulating insulin/Akt signaling post-MI. Thus, NE may enhance myocardial injury by inducing an excessive inflammatory response and suppressing Akt signaling in cardiomyocytes. Inhibition of NE might serve as a novel therapeutic target in the treatment of MI.