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Association between calcium-phosphorus balance and adolescent idiopathic scoliosis: A meta-analysis.
Zhu, Q, Chen, J, Chen, C, Wang, H, Yang, S
Acta orthopaedica et traumatologica turcica. 2019;(6):468-473
Abstract
STUDY DESIGN A systematic review and meta-analysis. OBJECTIVE The objective of this meta-analysis was to evaluate the association between calcium-phosphorus balance and adolescent idiopathic scoliosis (AIS). METHODS Databases, including PubMed, OVID database, Web of Science, CBM database and CNKI database were searched for the relevant case control studies and cross-sectional studies. Two authors selected studies and extracted data independently. Data analysis was performed by Review Manager Software 5.0. Subgroup analysis was performed on the serum level of vitamin D according to gender and menstruation. RESULTS Five studies were included, with a total of 646 cases of AIS and 791 controls. AIS group had a lower serum level of vitamin D compared to control group [MD = -6.74, 95% CI (-9.47, -4.00)]. Gender and menstruation condition were thought to have no effect on the primary outcome of vitamin D level by subgroup analysis [MD = -5.97, 95% CI (7.61, -4.34)]. The AIS group had a lower calcium level [SMD= -0.77, 95% CI (-1.51, -0.02)] and calcitonin level compared to control group. There was no statistical difference in phosphorus level [SMD=0.5, 95% CI (-0.46, 0.57)] and parathyroid hormone level [SMD = -0.11, 95% CI (-0.54, -0.31)]. Meanwhile, the observational indexes, including serum levels of calcium, phosphorus, parathyroid hormone and calcitonin were within normal limits. CONCLUSION Vitamin D deficiency may be involved in the pathogenesis of AIS by influencing the regulation of calcium-phosphors metabolism on human bone. Therefore, we suggest to screen vitamin D level in AIS patients. LEVEL OF EVIDENCE Level III, Therapeutic Study.
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Evidence for calpains in cancer metastasis.
Chen, J, Wu, Y, Zhang, L, Fang, X, Hu, X
Journal of cellular physiology. 2019;(6):8233-8240
Abstract
Metastatic dissemination represents the final stage of tumor progression as well as the principal cause of cancer-associated deaths. Calpains are a conserved family of calcium-dependent cysteine proteinases with ubiquitous or tissue-specific expression. Accumulating evidence indicates a central role for calpains in tumor migration and invasion via participating in several key processes, including focal adhesion dynamics, cytoskeletal remodeling, epithelial-to-mesenchymal transition, and apoptosis. Activated after the increased intracellular calcium concentration ( [Ca2+]i ) induced by membrane channels and extracellular or intracellular stimuli, calpains induce the limited cleavage or functional modulation of various substrates that serve as metastatic mediators. This review covers established literature to summarize the mechanisms and underlying signaling pathways of calpains in cancer metastasis, making calpains attractive targets for aggressive tumor therapies.
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The Association Between Calcium, Magnesium, and Ratio of Calcium/Magnesium in Seminal Plasma and Sperm Quality.
Liang, H, Miao, M, Chen, J, Chen, K, Wu, B, Dai, Q, Wang, J, Sun, F, Shi, H, Yuan, W
Biological trace element research. 2016;(1):1-7
Abstract
The study aimed to examine the relationships between calcium, magnesium, and calcium/magnesium ratio in semen plasma and sperm quality. It was a cross-sectional study based on a program aiming at promoting the reproductive health in less-developed areas. A total of 515 men aged between 18 and 55 years provided semen specimens at family planning clinics in Sandu County, Guizhou Province, China. Total calcium and magnesium concentrations in semen plasma were measured with flame atomic absorption spectrometry. Sperm quality, including sperm motility and concentration, was evaluated by using a computer-assisted sperm analysis method. The medians of seminal plasma calcium, magnesium, and zinc concentrations were 9.61, 4.41, and 2.23 mmol/l, respectively. Calcium concentration and calcium/magnesium ratio were negatively associated with sperm concentrations (β = -0.47, P = 0.0123 for calcium; β = -0.25, P = 0.0393 for calcium/magnesium ratio) after adjusting for zinc and other covariates. In stratified analyses, the association between calcium and sperm concentrations only persisted among subjects with a calcium/magnesium ratio of ≤2.5 (β = -0.71, P = 0.0268). In the same stratum, magnesium was associated with increased sperm concentration (β = 0.73, P = 0.0386). Among subjects with a calcium/magnesium ratio of >2.5, neither calcium nor magnesium was associated with sperm concentration. In conclusion, total calcium and magnesium concentrations were associated with sperm concentration among subjects with a lower calcium/magnesium ratio. The calcium and magnesium ratio had a modifying effect on the associations of calcium and magnesium with sperm concentration.
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Calcium signaling during reproduction and biotrophic fungal interactions in plants.
Chen, J, Gutjahr, C, Bleckmann, A, Dresselhaus, T
Molecular plant. 2015;(4):595-611
Abstract
Many recent studies have indicated that cellular communications during plant reproduction, fungal invasion, and defense involve identical or similar molecular players and mechanisms. Indeed, pollen tube invasion and sperm release shares many common features with infection of plant tissue by fungi and oomycetes, as a tip-growing intruder needs to communicate with the receptive cells to gain access into a cell and tissue. Depending on the compatibility between cells, interactions may result in defense, invasion, growth support, or cell death. Plant cells stimulated by both pollen tubes and fungal hyphae secrete, for example, small cysteine-rich proteins and receptor-like kinases are activated leading to intracellular signaling events such as the production of reactive oxygen species (ROS) and the generation of calcium (Ca(2+)) transients. The ubiquitous and versatile second messenger Ca(2+) thereafter plays a central and crucial role in modulating numerous downstream signaling processes. In stimulated cells, it elicits both fast and slow cellular responses depending on the shape, frequency, amplitude, and duration of the Ca(2+) transients. The various Ca(2+) signatures are transduced into cellular information via a battery of Ca(2+)-binding proteins. In this review, we focus on Ca(2+) signaling and discuss its occurrence during plant reproduction and interactions of plant cells with biotrophic filamentous microbes. The participation of Ca(2+) in ROS signaling pathways is also discussed.
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Effects and safety of calcimimetics in end stage renal disease patients with secondary hyperparathyroidism: a meta-analysis.
Zhang, Q, Li, M, You, L, Li, H, Ni, L, Gu, Y, Hao, C, Chen, J
PloS one. 2012;(10):e48070
Abstract
PURPOSE Secondary hyperparathyroidism (SHPT) is one of the most common abnormalities of mineral metabolism in patients with chronic kidney disease. We performed a meta-analysis to determine the effect and safety of cinacalcet in SHPT patients receiving dialysis. METHODS The meta-analysis was performed to determine the effect and safety of cinacalcet in SHPT patients receiving dialysis by using the search terms 'cinacalcet' or 'mimpara' or 'sensipar' or 'calcimimetic' or 'R586' on MEDLINE and EMBASE (January 1990 to February 2012). RESULTS Fifteen trials were included, all of which were performed between 2000 and 2011 enrolling a total of 3387 dialysis patients. Our study showed that calcimimetic agents effectively ameliorated iPTH levels(WMD, -294.36 pg/mL; 95% CI, -322.76 to -265.95, P<0.001) in SHPT patients and reduced serum calcium (WMD, -0.81 mg/dL; 95% CI, -0.89 to -0.72, P<0.001) and phosphorus disturbances(WMD, -0.29 mg/dL; 95% CI, -0.41 to -0.17, P<0.001). The percentage of patients in whom there was a 30% decrease in serum iPTH levels by the end of the dosing was higher in cinacalcet group than that in control group(OR = 10.75, 95% CI: 6.65-17.37, P<0.001). However, no significant difference was found in all-cause mortality and all adverse events between calcimimetics and control groups(OR = 0.86, 95% CI: 0.46-1.60, P = 0.630; OR = 1.30, 95% CI: 0.78-2.18, P = 0.320, respectively). Compared with the control therapy, there was a significant increase in the episodes of hypocalcemia (OR = 2.46, 95% CI: 1.58-3.82, P<0.001), nausea (OR = 2.45, 95% CI: 1.29-4.66, P = 0.006), vomiting(OR = 2.78, 95% CI: 2.14-3.62, P<0.001), diarrhea(OR = 1.51, 95% CI: 1.04-2.20, P = 0.030) and upper respiratory tract infection (OR = 1.79, 95% CI: 1.20-2.66, P = 0.004)in calcimimetics group. CONCLUSIONS Calcimimetic treatment effectively improved biochemical parameters of SHPT patients receiving dialysis without increasing all-cause mortality and all adverse events.
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Effects of diltiazem on platelet activation and cytosolic calcium during percutaneous transluminal coronary angioplasty.
Dai, H, Chen, J, Tao, Q, Zhu, J, Zhang, F, Zheng, L, Qiu, Y
Postgraduate medical journal. 2003;(935):522-6
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Abstract
AIMS: To evaluate effects of diltiazem on platelet hyper-reactivity in situations associated with endothelial injury and their possible relationship to cytosolic calcium concentration. METHODS Blood samples were collected at seven time points from 35 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) who received combined diltiazem and aspirin/ticlopidine therapy or aspirin/ticlopidine therapy alone. Platelet expression of glycoprotein IIb/IIIa and P-selectin, production of thromboxane B(2), and cytosolic calcium concentration were measured, respectively, by whole blood flow cytometry, radioimmunoassay, and fluorospectrophotometry. The effects of diltiazem of different concentrations on expression of glycoprotein IIb/IIIa and P-selectin were also studied in vitro in blood samples from patients with chronic stable angina. RESULTS Of the two treatments, aspirin/ticlopidine therapy did not prevent an acute increase of expression of glycoprotein IIb/IIIa and P-selectin and plasma thromboxane B(2) five minutes and 10 minutes after first inflation and 10 minutes after PTCA, whereas combined diltiazem and aspirin/ticlopidine therapy had a significant inhibitory effect. In the group receiving aspirin/ticlopidine therapy, there was a short term increase of platelet [Ca(2+)](i) immediately after PTCA which was significantly reduced by diltiazem treatment. Expression of glycoprotein IIb/IIIa and P-selectin was significantly inhibited in vitro by diltiazem in the concentration of 200 ng/ml or higher, but not 50 ng/ml. CONCLUSIONS Combined diltiazem and aspirin/ticlopidine therapy significantly inhibited platelet activation that continued in the presence of conventional aspirin/ticlopidine treatment. Antiplatelet effects of diltiazem were probably a consequence of reduction of platelet [Ca(2+)](i) and may only be achieved in higher than therapeutic concentrations.