Direct effects of caffeine on osteoblastic cells metabolism: the possible causal effect of caffeine on the formation of osteoporosis

BACKGROUND: Caffeine consumption has been reported to decrease bone mineral density (BMD), increase the risk of hip fracture, and negatively influence calcium retention. In this study, we investigated the influence of caffeine on the osteoblasts behaviour. METHOD: Osteoblasts derived from newborn Wistar-rat calvaria was used in this study. The effects of various concentrations of caffeine on bone cell activities were evaluated by using MTT assay. Alkaline phosphatase (ALP) staining, von Kossa staining and biochemical parameters including ALP, lactate dehydrogenase (LDH), prostaglandin E(2 )(PGE(2)) and total protein were performed at day 1, 3, and 7. DNA degradation analysis under the caffeine influence was also performed. RESULTS AND DISCUSSION: The results showed that the viability of the osteoblasts, the formation of ALP positive staining colonies and mineralization nodules formation in the osteoblasts cultures decreased significantly in the presence of 10 mM caffeine. The intracellular LDH, ALP and PGE(2 )content decreased significantly, the LDH and PGE(2 )secreted into the medium increased significantly. The activation of an irreversible commitment to cell death by caffeine was clearly demonstrated by DNA ladder staining. CONCLUSION: In summary, our results suggest that caffeine has potential deleterious effect on the osteoblasts viability, which may enhance the rate of osteoblasts apoptosis

Isokinetic eccentric exercise can induce skeletal muscle injury within the physiologic excursion of muscle-tendon unit: a rabbit model

BACKGROUND AND PURPOSE: Intensive eccentric exercise can cause muscle damage. We simulated an animal model of isokinetic eccentric exercise by repetitively stretching stimulated triceps surae muscle-tendon units to determine if such exercise affects the mechanical properties of the unit within its physiologic excursion. METHODS: Biomechanical parameters of the muscle-tendon unit were monitored during isokinetic eccentric loading in 12 rabbits. In each animal, one limb (control group) was stretched until failure. The other limb (study group) was first subjected to isokinetic and eccentric cyclic loading at the rate of 10.0 cm/min to 112% (group I) or 120% (group II) of its initial length for 1 hour and then stretched to failure. Load-deformation curves and biomechanical parameters were compared between the study and control groups. RESULTS: When the muscle-tendon unit received eccentric cyclic loading to 112%, changes in all biomechanical parameters – except for the slope of the load-deformation curve – were not significant. In contrast, most parameters, including the slope of the load-deformation curve, peak load, deformation at peak load, total energy absorption, and energy absorption before peak load, significantly decreased after isokinetic eccentric cyclic loading to 120%. CONCLUSION: We found a threshold for eccentrically induced injury of the rabbit triceps surae muscle at between 12% and 20% strain, which is within the physiologic excursion of the muscle-tendon units. Our study provided evidence that eccentric exercise may induce changes in the biomechanical properties of skeletal muscles, even within the physiologic range of the excursion of the muscle-tendon unit

Isoflavones prevent bone loss following ovariectomy in young adult rats

Soy protein, a rich source of phytoestrogens, exhibit estrogen-type bioactivity. The purpose of this study was to determine if ingestion of isoflavones before ovariectomy can prevent bone loss following ovariectomy. Twenty-four nulliparous Wistar rats were randomly divided into four groups. In the normal diet groups, a sham operation was performed on Group A, while ovariectomy was performed on Group B. For Groups C and D, all rats were fed with an isoflavone-rich (25 mg/day) diet for one month, then bilateral ovariectomy were performed. In the rats in Group C, a normal diet was begun following the ovariectomy. The rats in Groups D continued to receive the isoflavone-rich diet for two additional months postoperatively. All rats were sacrificed 60 days after surgery. The weight of bone ash of the long bones and whole lumbar spine were determined. A histological study of cancellous bone was done and biochemical indices of skeletal metabolism were performed and analyzed. The markers of bone metabolism exhibited no significant changes. When compared with the sham-operated rats fed a normal diet, the bone mass of ovariectomized rats decreased significantly; pre-ovariectomy ingestion of an isoflavone-rich diet did not prevent bone loss. The bone mass of rats treated with an isoflavone-rich diet for three months was higher than controls two months after ovariectomy

Studies of Photokilling of Bacteria Using Titanium Dioxide Nanoparticles

Metal pins used to apply skeletal traction or external fixation devices protruding through skin are susceptible to the increased incidence of pin site infection. In this work, we tried to establish the photokilling effects of titanium dioxide (TiO2) nanoparticles on an orthopedic implant with an in vitro study. In these photocatalytic experiments, aqueous TiO2 was added to the tested microorganism. The time effect of TiO2 photoactivation was evaluated, and the loss of viability of five different bacteria suspensions ( Escherichia coli, Pseudomonas aeruginosa, Staphylococus aureus, Enterococcus hirae, and Bacteroides fragilis) was examined by the viable count procedure. The bactericidal effect of TiO2 nanoparticle-coated metal plates was also tested. The ultraviolet (UV) dosage used in this experiment did not affect the viability of bacteria, and all bacteria survived well in the absence of TiO2 nanoparticles. The survival curve of microorganisms in the presence of TiO2 nanoparticles showed that nearly complete killing was achieved after 50 min of UV illumination. The formation of bacterial colonies above the TiO2 nanoparticle-coated metal plates also decreased significantly. In this study, we clearly demonstrated the bactericidal effects of titanium dioxide nanoparticles. In the presence of UV light, the titanium dioxide nanoparticles can be applicable to medical facilities where the potential for infection should be controlled

Effects of Shock Waves on Tenocyte Proliferation and Extracellular Matrix Metabolism

The shock wave is an effective noninvasive modality for resolving various tendon pathologies. However, scientific rationale and mechanism of shock wave therapy remains limited. This study aims to investigate the effects of shock waves and their biochemical mechanisms on tenocyte proliferation and collagen synthesis. Tenocytes harvested from Achilles tendons of Sprague-Dawley rats were used in this study. Cell viability was assayed by trypan blue exclusion methods. The colorimetric assay was determined to evaluate the mitochondria activity of the tenocytes after shock wave exposure. Synthesis of collagen, nitric oxide (NO ) and. transforming growth factor-beta 1 (TGF-beta 1) were determined and their gene expression was also studied. The results showed that there was a dose- dependent impairment of cell viability observed in 0.36 mJ/mm(2) and 0.68 mJ/mm(2) stimulation. In the proliferation assay, low energy level with low impulses (0.36 mJ/mm(2) with 50 and 100 impulses) showed positive stimulatory effects, whereas the high energy level with high impulses (0. 68 mJ/mm(2) with 250 and 500 impulses) had significant inhibitory effects. At 0.36 mJ/mm( 2), 100 impulse shock waves treatment, up-regulation of proliferating cell nuclear antigen (PCNA) (at 6 and 24 h) and collagen type I, collagen type III and TGF-beta 1 gene expression (at 24 h) were observed; these were followed by the increases in NO production (at 24 h), TGF-beta 1 release (at 48 and 96 h) and collagen synthesis (at the 7th day). This study revealed that shock waves can stimulate tenocyte proliferation and collagen synthesis. The associated tenocyte proliferation is mediated by early up-regulation of PCNA and TGF-beta 1 gene expression, endogenous NO release and synthesis and TGF-beta 1 protein and then collagen synthesis

Effect of Dynamic Compression on in Vitro Chondrocyte Metabolism

BACKGROUND: Chondrocytes can detect and respond to the mechanical environment by altering their metabolism. This study was designed to explore the effects of dynamic compression on chondrocyte metabolism. METHODS: Chondrocytes were harvested from newborn Wistar rats. After 7 days of expansion, chondrocytes embedded in agarose discs underwent uniaxial unconfined dynamic compression loads at different amplitudes (5%, 10%, and 15%) and frequencies (0.5 Hz, 1.0 Hz, 2.0 Hz, and 3.0 Hz) with a duration of 24 hours. The delayed effects on the chondrocytes were studied at 1, 3, and 7 days after the experiment. RESULTS: The results showed that at 10% strain, higher-frequency compression pressure can enhance the proliferation of chondrocytes. The synthesis of glycosaminoglycan (GAG) increased at 10%-15% strain and a 1-Hz load. The synthesis of nitric oxide (NO) increased at the 0.5-Hz load; while decreasing at the 15% strain. With 10% strain, 1 Hz dynamic compression, the proliferation of chondrocytes and GAG synthesis increased and persisted for 7 days, and NO synthesis decreased at the third and seventh days of culture. CONCLUSIONS: This study showed that chondrocytes respond metabolically to compressive loading, which is expected to modulate the growth and the resultant biomechanical properties of these tissue- engineered constructs during culture

Neuroprotective Effect of Schisandra Chinensis on Methyl-4-Phenyl-1,2,3,6-Tetrahydropyridine-Induced Parkinsonian Syndrome in C57BL/6 Mice

Schisandra chinensis (Turcz.) Baill. (S. chinensis) is a well-known botanical medicine and nutritional supplement that has been shown to have potential effects on neurodegeneration. To investigate the potential neuroprotective effect of S. chinensis fruit extract, 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) was used to induce behavioral disorders and dopaminergic neuronal damage in mice, and biochemical indicators were examined. Male C57BL/6 mice were used to establish the MPTP-induced parkinsonian syndrome model. Open field and rotarod tests were performed to evaluate the overall manifestation of motor deficits and rodent motor coordination. The mice were divided into 8 groups as follows: normal control; MPTP alone (25 mg/kg, i.p.); S. chinensis extract pretreatment (0.5, 1.5, 5 g/kg, p.o.); and S. chinensis extract treatment (0.5, 1.5, 5 g/kg, p.o.). Liquid chromatography coupled to electrochemical detection was used to monitor neurochemicals in the striatum. Tyrosine hydroxylase content was measured by immunohistochemistry, and biochemical antioxidative indicators were used to evaluate the potential neuroprotective effects of S. chinensis fruit extract. The results demonstrated that treatment with S. chinensis fruit extract ameliorated MPTP-induced deficits in behavior, exercise balance, dopamine level, dopaminergic neurons, and tyrosine hydroxylase-positive cells in the striatum of mice. Among the pretreated and treatment groups, a high dose of S. chinensis fruit extract was the most effective treatment. In conclusion, S. chinensis fruit extract is a potential herbal drug candidate for the amelioration and prevention of Parkinson’s disease

Gouty Arthropathy of the Cervical Spine in a Young Adult

We report a young man with gouty discitis of the cervical spine. To our knowledge, our patient is the youngest patient with cervical gouty discitis reported in the literature. The clinical manifestation was similar to that of cervical spondylosis with radiculopathy. Gouty discitis was diagnosed only when tophi in the disc were found during surgery and proved by pathologic study. Surgical decompression followed by optimization of pharmacologic treatment enabled good recovery from neurologic complications