Sex differences in factors associated with poor subjective sleep quality in athletes.

BACKGROUND: Sleep is an important recovery period for athletes. In general, women are not satisfied with their sleep quality, which is also true for female soccer players, although the reasons remain to be elucidated. This study aimed to confirm sex difference in sleep quality among athletes from various fields of sport, and to investigate factors related to poor subjective sleep quality in male and female athletes. METHODS: We collected data concerning subjective sleep quality, measured by Pittsburgh Sleep Quality Index (PSQI), from athletes who were 16 to 40 years of age and played various types of sports. Data concerning their sports, lifestyle, and sleep issues and sleep environments, and also menstrual issues for females, were collected. RESULTS: Data from 207 male athletes and 215 female athletes were assessed. Among them, 31.4% of men and 48.8% of women had poor subjective sleep quality (i.e., PSQI≥6). In male athletes, witnessed apnea, episodes of disorientation or confusion during the time of sleep, long time gap between dinner and bedtime, and turning on the heating in the winter, were identified as factors associated with poor sleep quality by multivariate analysis, whereas in female athletes, bathing close to bedtime, habitual drinking, and being annoyed by noises at bedtime were identified. CONCLUSIONS: In both populations, females had poorer subjective sleep quality than males. Sex differences exist in factors associated with poor subjective sleep quality. Thus, different approaches should be considered to improve their sleep quality.

The use of blood vessel-derived stem cells for meniscal regeneration and repair.

PURPOSE: Surgical repairs of tears in the vascular region of the meniscus usually heal better than repairs performed in the avascular region; thus, we hypothesized that this region might possess a richer supply of vascular-derived stem cells than the avascular region. METHODS: In this study, we analyzed 6 menisci extracted from aborted human fetuses and 12 human lateral menisci extracted from adult human subjects undergoing total knee arthroplasty. Menisci were immunostained for CD34 (a stem cell marker) and CD146 (a pericyte marker) in situ, whereas other menisci were dissected into two regions (peripheral and inner) and used to isolate meniscus-derived cells by flow cytometry. Cell populations expressing CD34 and CD146 were tested for their multilineage differentiation potentials, including chondrogenic, osteogenic, and adipogenic lineages. Fetal peripheral meniscus cells were transplanted by intracapsular injection into the knee joints of an athymic rat meniscal tear model. Rat menisci were extracted and histologically evaluated after 4 wk posttransplantation. RESULTS: Immunohistochemistry and flow cytometric analyses demonstrated that a higher number of CD34- and CD146-positive cells were found in the peripheral region compared with the inner region. The CD34- and CD146-positive cells isolated from the vascular region of both fetal and adult menisci demonstrated multilineage differentiation capacities and were more potent than cells isolated from the inner (avascular) region. Fetal CD34- and CD146-positive cells transplanted into the athymic rat knee joint were recruited into the meniscal tear sites and contributed to meniscus repair. CONCLUSIONS: The vascularized region of the meniscus contains more stem cells than the avascular region. These meniscal-derived stem cells were multipotent and contributed to meniscal regeneration.

Biophysical evaluation of fractional laser skin resurfacing with an Er:YSGG laser device in Japanese skin.

BACKGROUND: Ablative fractional laser skin resurfacing (FLSR) has recently been used for the amelioration of acne scars, and previous studies have shown clinical effectiveness. Despite its extensive use, few studies have focused on the associated changes in biophysical properties of the epidermis. Herein, we evaluate transepidermal water loss, sebum levels, skin hydration, and skin elasticity, following FLSR treatments with an Er:YSGG laser device (Pearl FractionalTM, Cutera Inc., Brisbane, CA), employing non-invasive measurements. METHODS: Five Japanese patients with facial acne scars underwent one FLSR session. Some acne scars appeared to become less obvious as a consequence of the treatment. All patients were aware of a feeling of skin tightness in treated areas. RESULTS: Objective measurements on the lower lateral angle of the eye and on the inner cheeks were evaluated at baseline and at 3 days, 1 week, and 4 weeks after FLSR. Transepidermal water loss showed a significant two-fold (100%) increase at day 3, but had returned to almost the baseline level at week 4 in both areas. Sebum secretion showed a 50% increase at day 3, but had returned to the baseline level after day 7. Skin hydration showed a significant decrease at day 3, but had returned to the baseline level by day 7, and showed significant improvement at the end of the study. Skin elasticity (R2) was still at baseline on day 3, but showed some improvement--an increase of at least 30%--at the end of the study. CONCLUSIONS: Based on our findings, we believe that FLSR should be performed no more than once a month to allow sufficient time for the damaged skin to recover its barrier function in most areas of the face.

Isolation and characterization of human anterior cruciate ligament-derived vascular stem cells.

The anterior cruciate ligament (ACL) usually fails to heal after rupture mainly due to the inability of the cells within the ACL tissue to establish an adequate healing process, making graft reconstruction surgery a necessity. However, some reports have shown that there is a healing potential of ACL with primary suture repair. Although some reports showed the existence of mesenchymal stem cell-like cells in human ACL tissues, their origin still remains unclear. Recently, blood vessels have been reported to represent a rich supply of stem/progenitor cells with a characteristic expression of CD34 and CD146. In this study, we attempted to validate the hypothesis that CD34- and CD146-expressing vascular cells exist in hACL tissues, have a potential for multi-lineage differentiation, and are recruited to the rupture site to participate in the intrinsic healing of injured ACL. Immunohistochemistry and flow cytometry analysis of hACL tissues demonstrated that it contains significantly more CD34 and CD146-positive cells in the ACL ruptured site compared with the noninjured midsubstance. CD34+CD45- cells isolated from ACL ruptured site showed higher expansionary potentials than CD146+CD45- and CD34-CD146-CD45- cells, and displayed higher differentiation potentials into osteogenic, adipogenic, and angiogenic lineages than the other cell populations. Immunohistochemistry of fetal and adult hACL tissues demonstrated a higher number of CD34 and CD146-positive cells in the ACL septum region compared with the midsubstance. In conclusion, our findings suggest that the ACL septum region contains a population of vascular-derived stem cells that may contribute to ligament regeneration and repair at the site of rupture.

A longitudinal study of the relationship between the status of bone marrow abnormalities and progression of knee osteoarthritis.

BACKGROUND: Bone marrow abnormalities (BMAs) detected on magnetic resonance imaging (MRI) are suggested to be involved in the pathogenesis of osteoarthritis (OA), and the size of the BMAs is associated with the progression of OA. However, it still remains unclear as to whether the associations of BMA size and OA severity are observed equally or whether they differ from early to advanced stages of OA. In the present study we examined whether BMA enlargement and OA progression differed according to the severity of OA. METHODS: One hundred and eighty patients with knee OA were enrolled in the present study, and 122 of these patients completed this study. Radiography and knee MRI were done two times in all patients, at the baseline and 6 months or later at the time of patient follow-up. The severity of OA was evaluated by radiography using the Kellgren-Lawrence (K-L) grade. The patients who showed a deterioration in the K-L grade during the follow-up examination (59/122) were defined as the deterioration group. T2-weighted fat-suppressed MR images were used to score the size of the BMAs according to the whole-organ magnetic resonance imaging score (WORMS). A new scoring system, the spacial BMA score (s-score) was defined to assess the size of the BMAs three-dimensionally. RESULTS: In patients with K-L grade 2, the s-score changes during the follow-up period in the deterioration group were significantly increased in comparison to those in the no-change group (P = 0.04), and no significant s-score changes were observed in patients with either K-L grade 1 or 3 (P = 0.07 and 0.57) between the deterioration group and the no-change group during the follow-up examination. In patients with K-L grade 3, the s-score at the baseline in the deterioration group was higher than that in the no-change group (P = 0.05). CONCLUSIONS: The relationship between the size and enlargement of BMAs and the progression of OA changed depending upon the severity of OA.

The influence of sex on the chondrogenic potential of muscle-derived stem cells: implications for cartilage regeneration and repair.

OBJECTIVE: To explore possible differences in muscle-derived stem cell (MDSC) chondrogenic differentiation in vitro and articular cartilage regeneration in vivo between murine male MDSCs (M-MDSCs) and female MDSCs (F-MDSCs). METHODS: Three different populations of M- and F-MDSCs (n = 3 of each sex) obtained via preplate technique, which separates cells based on their variable adhesion characteristics, were compared for their in vitro chondrogenic potential using pellet culture. Cells were assayed with and without retroviral transduction to express bone morphogenetic protein 4 (BMP-4). The influence of both expression of stem cell marker Sca1 and in vitro expansion on the chondrogenic potential of M- and F-MDSCs was also determined. Additionally, BMP-4-transduced M- and F-MDSCs were applied to a full-thickness articular cartilage defect (n = 5 each) on the femur of a nude rat, and the quality of the repaired tissue was evaluated by macroscopic and histologic examination. RESULTS: With and without BMP-4 gene transduction, M-MDSCs produced significantly larger pellets with a richer extracellular matrix, compared with F-MDSCs. Sca1 purification influenced the chondrogenic potential of MDSCs, especially M-MDSCs. Long-term culture did not affect the chondrogenic potential of M-MDSCs but did influence F-MDSCs. M-MDSCs repaired articular cartilage defects more effectively than did F-MDSCs at all time points tested, as assessed both macroscopically and histologically. CONCLUSION: Our findings demonstrate that sex influences the chondrogenic differentiation and articular cartilage regeneration potential of MDSCs. Compared with female MDSCs, male MDSCs display more chondrogenic differentiation and better cartilage regeneration potential.

Additive effects of glucosamine or risedronate for the treatment of osteoarthritis of the knee combined with home exercise: a prospective randomized 18-month trial.

We have previously demonstrated the efficacy of therapeutic exercise for osteoarthritis (OA) of the knee. This study was performed to examine the additive effects of glucosamine or risedronate on the exercise therapy. In this study, 142 female patients with moderate OA of the knee, who had been recommended to undergo home exercise at the first visit to the hospital, were randomly given glucosamine hydrochloride, risedronate, or no additive. Although improvement after 18 months was observed in all groups using individual scales for evaluation of pain and function of the knee, no significant differences were observed between the groups regarding any of the scales, indicating no significant additive effect of glucosamine or risedronate. One reason for the lack of effect of glucosamine or risedronate on OA of the knee may be that the effect of these agents was occluded by the effect of therapeutic exercise to improve pain and function of the knee. This finding means that even if glucosamine and risedronate were to have an effect on OA of the knee, the effect would not be greater than the effect of knee exercise to improve the symptoms.

Activation of genes for growth factor and cytokine pathways late in chondrogenic differentiation of ATDC5 cells.

The mouse embryonal carcinoma cell line ATDC5 provides an excellent model system for chondrogenesis in vitro. To understand better the molecular mechanisms of endochondral bone formation, we investigated gene expression profiles during the differentiation course of ATDC5 cells, using an in-house microarray harboring full-length-enriched cDNAs. For 28 days following chondrogenic induction, 507 genes were up- or down-regulated at least 1.5-fold. These genes were classified into five clusters based on their expression patterns. Genes for growth factor and cytokine pathways were significantly enriched in the cluster characterized by increases in expression during late stages of chondrocyte differentiation. mRNAs for decorin and osteoglycin, which have been shown to bind to transforming growth factors-beta and bone morphogenetic proteins, respectively, were found in this cluster and were detected in hypertrophic chondrocytes of developing mouse bones by in situ hybridization analysis. Taken together with assigned functions of individual genes in the cluster, interdigitated interaction between a number of intercellular signaling molecules is likely to take place in the late chondrogenic stage for autocrine and paracrine regulation among chondrocytes, as well as for chemoattraction and stimulation of progenitor cells of other lineages.