Effect of Different Calcium Supplements on Bone Metabolism in Rats

Osteoporosis, characterized by loss of bone mass and microarchitectural deterioration of bone tissue, results in enhanced bone fragility and increases risk of fractureIll. In China, the incidence of primary osteoporosis is as high as 50%-70% in 60-69 years old females and approximately 30% in 60-69 years old males[21, which is closely related with the low intake of calcium. According to the nationwide nutrition and health survey in 2002 in China, the average daily calcium intake of Chinese residents is 391 mg, accounting for 41% of the recommended calcium intake.

Long-Term Animal Feeding Trial of the Refined Konjac Meal Ⅰ. Effects of the Refined Konjac Meal on the Calcium and Phosphorus Metabolism and the Bone in Rat

Effects of refined konjac meal (RKM) on the calcium and phosphorus metabolism and bone parameters were observed in rats of both sexes fed with food containing 1% of RKM for 18 months. A comparable group of rats fed on basic diet only was used as a control.Results obtained indicate that all the measured parameters (serum calcium and phosphorus level, femur weight and its calcium and phesphorus content, and the osteometry of the tibia) showed no significant difference between the experimental and the control groups.Thus there is no adverse effect either on the calcium and phosphorus metabolism or on the bone after a long-term intake at a moderate dosage.

EXPERIMENTAL STUDY ON THE BLOOD BIOCHEMICAL PARAMETERS FOR THE PROMOTION OF FRACTURE HEALING BY MS

This paper describes an experimental study about magnetic stimulation (MS) effects on the fracture healing of 120 fresh fractures and their blood biochemical parameters during their recovery. The mechanism of promoting the recovering process by MS is discussed and analysed. The experiments show that MS can advance calcium deposit on fractured bones and metabolism of calcium and phosphorus, which promote the process of fracture healing.

Research Progresses on Physiological Functions of Vitamin D

Vitamin D is a fat soluble vitamin that is foundin a variety of forms , amongwhich 1,25-（0H） 2D3 is themain active form. It not only exhibits a major physiological function to regulate the metabolism of calcium and phosphorus, but also relates to the prevention and treatment of a variety of diseases such as lung diseases, cancers, diabetes, tuberculosis, lupus erythematosus, autoimmune diseases and liver damage. In this paper, the latest research progresses of the physiological function of vitamin D were summarized and discussed, aiming at providing the solid basis for utilization and application of vitamin D.

Effect of combining different calcium concentration dialysate on calcium balance in peritoneal dialysis patients

Background Calcium and phosphorus metabolic disturbance are common in dialysis patients and associated with increased morbidity and mortality. Therefore, maintaining the balance of calcium and phosphate metabolism and suitable intact parathyroid hormone （iPTH） level has become the focus of attention. We investigated the effects of different peritoneal dialysate calcium concentrations on calcium phosphate metabolism and iPTH in continuous ambulatory peritoneal dialysis （CAPD） patients. Methods Forty stable CAPD patients with normal serum calcium were followed for six months of treatment with 1.25 mmol/L calcium dialysate （DCa1.25, PD4, 22 patients） or a combination of 1.75 mmol/L calcium dialysate （DCa1.75, PD2） and PD4 （18 patients） twice a day respectively. Total serum calcium （after albumin correction）, serum phosphorus, iPTH, alkaline phosphatase （ALP） and blood pressure were recorded before and 1, 3 and 6 months after treatment commenced. Results No significant difference was found in baseline serum calcium, phosphorus between the two patient groups, but the levels of iPTH were significantly different. No significant changes were found in the dosage of calcium carbonate and active vitamin D during 6 months. In the PD4 group, serum calcium level at the 1st, 3rd, 6th months were significantly lower than the baseline （P 〈0.05）. There was no significant difference in serum phosphorus after 6 months treatment. iPTH was significantly higher （P 〈0.001） at the 1st, 3rd, and 6th months compared with the baseline. No differences were seen in ALP and blood pressure. In the PD4＋PD2 group, no significant changes in serum calcium, phosphorus, iPTH, ALP and BP during the 6-month follow-up period. Conclusions Treatment with 1.25 mmol/L calcium dialysate for six months can decrease serum calcium, increase iPTH, without change in serum phosphorus, ALP, and BP. The combining of PD4 and PD2 can stabilize the serum calcium and avoid fluctuations in iPTH levels.

Cloning and Characterization of a Homologous Ca^(2+)/Calmodulin-Dependent Protein Kinase PSKH1 from Pearl Oyster Pinctada fucata

Many of the effects of Ca^2＋ signaling are mediated through the Ca^2＋/calmodulin complex and its acceptors, the Ca^2＋/calmodulin-dependent protein kinases, including PSKHI. Studies of the proteins involved in the calcium metabolism in oysters will help elucidate the pearl formation mechanism. This paper describes a full-length PSKH1 cDNA isolated from pearl oyster Pinctada fucata. Oyster PSKH1 shares 65% homology with human PSKH1 and 48% similarity with rat CaM kinase I in the amino acid sequence, and contains a calmodulin-binding domain. The results of semi-quantitative reverse transcription-polymerase chain reaction and in situ hybridization revealed that oyster PSKH1 mRNA is highly expressed in the outer epithelial cells of the mantle pallial and in the gill epithelial cells. These studies provide important information describing the complex Ca^2＋ signaling mechanism in oyster calcium metabolism.