Magnesium exposure increases hip fracture risks in patients with chronic kidney disease: a population-based nested case-control study.

This population-based study demonstrates a strong link between Mg-containing antacid exposure and hip fracture risk in nondialysis CKD and dialysis patients. As an Mg-containing antacid, MgO is also commonly used as a stool softener, which can be effortlessly replaced by other laxatives in CKD patients to maintain bone health. PURPOSE: Bone fracture is a severe complication in chronic kidney disease (CKD) patients, leading to disability and reduced survival. In CKD patients, blood magnesium (Mg) concentrations are usually above the normal range due to reduced kidney excretion of Mg. The present study examines the association between Mg-containing antacid exposure and the risk of hip fracture of CKD patients. METHODS: In this nationwide nested case-control study, we enrolled 44,062 CKD patients with hip fracture and 44,062 CKD matched controls, among which the mean age was 77.1 years old, and 87.9% was nondialysis CKD. RESULTS: As compared to non-users, Mg-containing antacid users were significantly more likely to experience hip fracture (adjusted odds ratio (OR) 1.36, 95% CI, 1.32 to 1.41; p < 0.001). Subgroup analysis showed that such risk exists in both nondialysis CKD patients and long-term dialysis patients. In contrast, aluminum or calcium-containing-antacid use did not reveal such association. Next, we examined the influence of Mg-containing antacid dosage on hip fracture risk, the adjusted ORs in the first quartile (Q1), Q2, Q3, and Q4 were 1.20 (95% CI, 1.15 to 1.25; p < 0.001), 1.35 (95% CI, 1.30 to 1.41; p < 0.001), 1.49 (95% CI, 1.43 to 1.56; p < 0.001), and 1.54 (95% CI, 1.47 to 1.61; p < 0.001), respectively, showing that such risk exists regardless of the antacid dosage. A receiver operating characteristic curve analysis demonstrated that the best cutoff value of the exposed Mg dose to discriminate the hip fracture is 532 mEq during the follow-up period. CONCLUSION: This population-based study demonstrates a strong link between Mg-containing antacid exposure and the hip fracture risk in both nondialysis CKD and dialysis patients.

Isolation and characterization of multipotent stem cells from human cruciate ligaments.

OBJECTIVES: Mesenchymal stem cells have great potential for tissue regeneration, and these cells can be harvested from a variety of tissues; however, up to now it has not been clear whether stem cells could be isolated from cruciate ligaments of the knee joint. The aim of our study was to isolate and characterize stem cells from both anterior and posterior cruciate ligaments (ACL and PCL) of humans. MATERIALS AND METHODS: Cruciate ligaments were obtained from patients receiving total knee arthroplasty for advanced osteoarthritis and plastic-adherent cells were serially passaged. In vitro chondrogenic, osteogenic and adipogenic abilities of the cells were evaluated by reverse transcriptase-polymerase chain reaction and histological study. Karyotyping and surface immunophenotyping of the cells were performed. RESULTS: It was found that a population of ligament-derived cells could be expanded and subcultured extensively. These cells were able to differentiate into osteoblasts, chondrocytes and adipocytes under appropriate inductions. Their phenotypic characteristics were similar to those of bone marrow mesenchymal stem cells. Karyotyping was normal after serial passage. CONCLUSIONS: In summary, our study demonstrates that human multipotent stem cells can be isolated and expanded from human ACL and PCL, which are easily obtained from patients following total knee or cruciate ligament reconstructive surgery. Self-renewal and mesodermal differentiation potential of these cells make them a viable alternative source for use in regenerative medicine.

Thymosin beta-4 upregulates anti-oxidative enzymes and protects human cornea epithelial cells against oxidative damage.

BACKGROUND: The ability to scavenge reactive oxygen species (ROS) is crucial for cornea epithelial cells to resist oxidative damage. The authors previously demonstrated that exogenous thymosin beta-4 (T beta(4)) was able to protect human cornea epithelial (HCE-T) cells against H(2)O(2)-induced oxidative damage, and its cellular internalisation was essential. The aim of this study is to further elucidate its protective mechanism. METHODS: HCE-T cells with or without T beta(4) pretreatment were exposed to H(2)O(2), and the differences in caspase activity, intracellular ROS levels, cell viability, and the expression of anti-oxidative enzymes, were measured and compared. RESULTS: Besides reducing caspase-9 activation and intracellular ROS levels induced by H(2)O(2), treatment of T beta(4) could also increase cell viability and stimulate the expression of manganese superoxide dismutase (SOD) and copper/zinc SOD. Moreover, both transcription and translation levels of catalase were also upregulated by T beta(4) in the presence of exogenous H(2)O(2). Furthermore, it was demonstrated that the addition of catalase inhibitor abrogated the protective effect of T beta(4) against H(2)O(2)-induced oxidative damage. CONCLUSION: To the best of the authors' knowledge, this is the first report to show that T beta(4 )was capable of upregulating anti-oxidative enzymes in human corneal epithelial cells, and these findings further support its role in cornea protection.