Are mindfulness treatments effective for pain in cancer patients? A systematic review and meta-analysis.

BACKGROUND AND OBJECTIVE: Mindfulness-based interventions (MBIs) have been recently applied in pain management and cancer care. However, inconsistencies exist concerning the effectiveness of MBIs on pain control among cancer patients. Therefore, this study aimed to examine the efficacy of MBIs on pain in cancer patients via a systematic review and meta-analysis of randomized controlled trials (RCTs). METHODS: Databases (MEDLINE, PubMed, Embase, CINAHL, PsycINFO, Cochrane Central Register of Controlled Trials and ClinicalTrials.gov) were searched using key terms related to pain, cancer and mindfulness. The primary outcome was pain intensity. Standardized mean difference (SMD) of each outcome with 95% confidence interval (95% CI) was calculated. The quality of evidence was assessed by GRADE assessment. RESULTS: Ten RCTs with 843 participants were included. Significant pooled effects of MBIs on pain intensity were found at both short-term (SMD = -0.19, 95% CI [-0.33 to -0.04]) and long-term (SMD = -0.20, 95% CI [-0.35 to -0.05]) follow-up, whereas no significance was observed for pain interference. In subgroup analyses, significant intervention effects were only seen in clinic-based MBIs compared to remote MBIs, and pooled effects of MBIs in attenuating pain were discovered relative to passive rather than active comparators. GRADE ratings showed moderate certainty of evidence in MBIs for pain intensity but low for pain interference. CONCLUSIONS: The efficacy of MBIs in reducing pain intensity among cancer patients was revealed in this meta-analysis, albeit with a small effect size. Future research is warranted to optimize mindfulness treatment for pain control in cancer patients with high methodological quality and a large sample size. SIGNIFICANCE: The effect of MBIs on pain in cancer patients was demonstrated in our analysis, albeit with small effect sizes. High-quality RCTs are needed to verify the efficacy of MBIs on cancer patients or survivors with pain complaints. Future trials should take into account the specific pain outcome measures (pain intensity or pain interference), the approach of intervention provision (clinic-based or remote MBI, group or individual practice), the duration and frequency of interventions and the comparators (passive or active control arms).

A GABAergic neural circuit in the ventromedial hypothalamus mediates chronic stress-induced bone loss.

Homeostasis of bone metabolism is regulated by the central nervous system, and mood disorders such as anxiety are associated with bone metabolism abnormalities, yet our understanding of the central neural circuits regulating bone metabolism is limited. Here, we demonstrate that chronic stress in crewmembers resulted in decreased bone density and elevated anxiety in an isolated habitat mimicking a space station. We then used a mouse model to demonstrate that GABAergic neural circuitry in the ventromedial hypothalamus (VMH) mediates chronic stress-induced bone loss. We show that GABAergic inputs in the dorsomedial VMH arise from a specific group of somatostatin neurons in the posterior region of the bed nucleus of the stria terminalis, which is indispensable for stress-induced bone loss and is able to trigger bone loss in the absence of stressors. In addition, the sympathetic system and glutamatergic neurons in the nucleus tractus solitarius were employed to regulate stress-induced bone loss. Our study has therefore identified the central neural mechanism by which chronic stress-induced mood disorders, such as anxiety, influence bone metabolism.

Multifunctional Nanoengineered Hydrogels Consisting of Black Phosphorus Nanosheets Upregulate Bone Formation.

Tissue-engineered hydrogels have received extensive attention as their mechanical properties, chemical compositions, and biological signals can be dynamically modified for mimicking extracellular matrices (ECM). Herein, the synthesis of novel double network (DN) hydrogels with tunable mechanical properties using combinatorial screening methods is reported. Furthermore, nanoengineered (NE) hydrogels are constructed by addition of ultrathin 2D black phosphorus (BP) nanosheets to the DN hydrogels with multiple functions for mimicking the ECM microenvironment to induce tissue regeneration. Notably, it is found that the BP nanosheets exhibit intrinsic properties for induced CaP crystal particle formation and therefore improve the mineralization ability of NE hydrogels. Finally, in vitro and in vivo data demonstrate that the BP nanosheets, mineralized CaP crystal nanoparticles, and excellent mechanical properties provide a favorable ECM microenvironment to mediate greater osteogenic cell differentiation and bone regeneration. Consequently, the combination of bioactive chemical materials and excellent mechanical stimuli of NE hydrogels inspire novel engineering strategies for bone-tissue regeneration.

Strontium-calcium coadministration stimulates bone matrix osteogenic factor expression and new bone formation in a large animal model.

Strontium (Sr) has become increasingly attractive for use in the prevention and treatment of osteoporosis by concomitantly inhibiting bone resorption and enhancing bone formation. Strontium shares similar chemical, physical, and biological characteristics with calcium (Ca), which has been widely used as a dietary supplement in osteoporosis. However, the effects of Sr-Ca coadministration on bone growth and remodeling are yet to be extensively reported. In this study, 18 ovariectomized goats were divided into four groups: three groups of five goats each treated with 100 mg/kg/day Ca, Ca plus 24 mg/kg/day Sr (Ca + 24Sr), or Ca plus 40 mg/kg/day Sr (Ca + 40Sr), and three untreated goats fed low calcium feed. Serum Sr levels increased 6- and 10-fold in the Ca + 24Sr and Ca + 40Sr groups, respectively. Similarly, Sr in the bone increased four- and sixfold in these two groups. Sr-Ca coadministration considerably increased bone mineral apposition rate (MAR). The expression of insulin-like growth factor (IGF)-1 and runt-related transcription factor 2 (Runx2) was significantly upregulated within the Ca + 40Sr treatment group; tumor necrosis factor (TNF)-agr; expression was significantly downregulated in the Ca and Ca + 40Sr groups. The results indicate that Sr-Ca coadministration increases osteogenic gene expression and stimulates new bone formation.