Prebiotics protect against acute graft-versus-host disease and preserve the gut microbiota in stem cell transplantation.

Acute graft-versus-host disease (aGVHD) is a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (allo-HSCT). Therefore, management of aGVHD is important for successful transplantation. Mucosal damage and alteration of the gut microbiota after allo-HSCT are key factors in the development of aGVHD. We conducted a prospective study to evaluate the ability of prebiotics, which can alleviate mucosal damage and manipulate the gut microbiota, to mitigate posttransplantation complications, including aGVHD. Resistant starch (RS) and a commercially available prebiotics mixture, GFO, were administered to allo-HSCT recipients from pretransplantation conditioning to day 28 after allo-HSCT. Prebiotic intake mitigated mucosal injury and reduced the incidence of all aGVHD grades combined and of aGVHD grades 2 to 4. The cumulative incidence of skin aGVHD was markedly decreased by prebiotics intake. Furthermore, the gut microbial diversity was well maintained and butyrate-producing bacterial population were preserved by prebiotics intake. In addition, the posttransplantation fecal butyrate concentration was maintained or increased more frequently in the prebiotics group. These observations indicate that prebiotic intake may be an effective strategy for preventing aGVHD in allo-HSCT, thereby improving treatment outcomes and the clinical utility of stem cell transplantation approaches. This study was registered on the University Hospital Medical Information Network (UMIN) clinical trials registry (https://www.umin.ac.jp/ctr/index.htm) as #UMIN000027563.

Variation among individual bulls in the distribution of acrosomal tyrosine-phosphorylated proteins in epididymal and ejaculated spermatozoa.

In Japanese black cattle, AI severely subfertile males have occasionally been found. In order to solve this problem, we previously asserted the need for exact examinations of acrosomal tyrosine-phosphorylated proteins and acrosome morphology in cryopreserved spermatozoa. In the present study, we further investigated acrosomal tyrosine-phosphorylated proteins in spermatozoa before cryopreservation and examined possible relationships between these phosphoproteins and acrosome stability. Ejaculated, epididymal and cryopreserved spermatozoa were subjected to examinations of general characteristics (motility, shape and acrosome morphology) and indirect immunofluorescence of acrosomal phosphoproteins. Unlike all general characteristic parameters, the distribution of acrosomal tyrosine-phosphorylated proteins in ejaculated and cauda epididymal spermatozoa varied considerably among bulls and was linked to the maintenance of morphologically normal acrosomes in cryopreserved spermatozoa or ejaculated spermatozoa after 270min incubation. Moreover, the distribution of these phosphoproteins was arranged in the spermatozoa of the proximal epididymides. These findings indicate that acrosomal tyrosine-phosphorylated proteins are distributionally arranged during early process of sperm maturation, that their distribution of cauda epididymal and ejaculated spermatozoa are largely different among bulls, and that varied states of acrosomal phosphoproteins may result in individual differences in acrosome stability among bulls.

Changes in the distribution and molecular mass of boar sperm acrosome-associated 1 proteins during the acrosome reaction; their validity as indicators for occurrence of the true acrosome reaction.

The aims of this study were to investigate changes in the distribution and molecular mass of boar sperm acrosome-associated 1 (SPACA1) proteins during the acrosome reaction and to discuss validity of SPACA1 proteins as indicators for occurrence of the true acrosome reaction. Boar ejaculated spermatozoa were used for induction of the extracellular Ca(2+)-dependent acrosome reaction (true acrosome reaction) or acrosomal damages (false acrosome reaction) and then subjected to double staining with the anti-SPACA1 protein antibody and FITC-PNA and Western blotting. Extracellular Ca(2+)-dependently acrosome-reacted spermatozoa were characterized by appearance of SPACA1 proteins in the postacrosomal region (; these spermatozoa were classified into SP-3&AR pattern of double staining). However, SPACA1 proteins were not observed in the postacrosomal region of frozen-thawed spermatozoa with severely damaged acrosomes (; these spermatozoa were classified into SP-2&AR pattern). Moreover, the spermatozoa in which acrosomes were severely damaged by incubation with cyclodextrins and without CaCl2 were classified into either SP-2&AR or SP-3&AR pattern. Although SPACA1 proteins were detected mainly as 36-42kDa proteins in the spermatozoa with intact acrosomes, small types of SPACA1 proteins (15-28kDa) increased in extracellular Ca(2+)-dependently acrosome-reacted spermatozoa as well as frozen-thawed spermatozoa with damaged acrosomes. These results show the increase of boar spermatozoa classified into SP-3&AR pattern after incubation in the medium with CaCl2 and without cyclodextrins indicates occurrence of the true acrosome reaction. Moreover, we suggest the increase of small types of SPACA1 proteins is a valid indicator for occurrence of the acrosomal disintegration arising from the true and false acrosome reactions.

Effect of warm air-drying on dentin bond strength of single-step self-etch adhesives.

The effect of warm air-drying on the dentin bond strengths of the single-step self-etch adhesives was determined. The adhesives were applied to bovine dentin followed by drying in a stream of warm air for 5, 10, and 15 s at 37°C. Resin composites were condensed into a mold and polymerized. Specimens were stored in distilled water at 37°C for 24 h, then shear tested. The surface free-energies were determined by measuring the contact angles of three test liquids placed on the cured adhesives. The dentin bond strengths varied according to the air-drying time. The value of the acid component increased slightly when drying was performed with a stream of warm air, whereas that of the base component decreased significantly. These data suggested that warm air-drying was essential to obtain adequate bond strengths, although increasing the drying time did not significantly influence the bond strength.

Influence of refractive index on optical parameters of experimental resin composites.

OBJECTIVE: Color characteristics of the experimental resin composites were determined to know the influence of different refractive index (RI) on optical parameters. MATERIALS AND METHODS: Four experimental light-cured resin composites of the same shade but with different RI were used. The colorimetric values of the specimens were measured against black and white backgrounds using spectrophotometry. The results were converted to CIE L*a*b* color-space values. The chroma (C*ab), color difference (ΔE), translucency parameter (TP) and opacity (OP, opposite property of TP) values were calculated. Surface gloss (GS) of the specimen was also measured. RESULTS: The L* coordinate, a* coordinate and ΔE*ab values increased as the difference in RI increased. The OP and GS values increased and the TP values decreased as the refractive-index difference increased. The L* and C*ab values increased as the value of the RI increased. The TP, OP and GS values were highly correlated with the RI value. The TP value decreased and the OP and GS values increased, as the RI value increased. CONCLUSIONS: Refractive index of resin composites is important when thinking about improving the color appearance of esthetic restorations.

Influence of power density and primer application on polymerization of dual-cured resin cements monitored by ultrasonic measurement.

We used ultrasonic measurements to monitor the influence of power density and primer application on the polymerization reaction of dual-cured resin cements. The ultrasonic equipment comprised a pulser-receiver, transducers, and an oscilloscope. Resin cements were mixed and inserted into a transparent mould, and specimens were placed on the sample stage, onto which the primer, if used, was also applied. Power densities of 0 (no irradiation), 200, or 600 mW cm(-2) were used for curing. The transit time through the cement disk was divided by the specimen thickness to obtain the longitudinal sound velocity. When resin cements were light-irradiated, each curve displayed an initial plateau of approximately 1,500 m s(-1), which rapidly increased to a second plateau of 2,300-2,900 m s(-1). The rate of sound velocity increase was retarded when the cements were light-irradiated at lower power densities, and increased when the primer was applied. The polymerization behaviour of dual-cured resin cements was therefore shown to be affected by the power density of the curing unit and the application of self-etching primer.