Administration frequency as well as dosage of PTH are associated with development of cortical porosity in ovariectomized rats

To investigate whether the administration frequency of parathyroid hormone(PTH) is associated with the development of cortical porosity, this study established 15 dosage regimens of teriparatide [human PTH(1–34), TPTD] with four distinct concentrations and four distinct administration frequencies of TPTD to 16-week-old ovariectomized rats. Our analyses demonstrated that the bone mineral density, mechanical properties, and bone turnover were associated with the total amount of TPTD administered. Our observations further revealed that the cortical porosity was markedly developed as a result of an increased administration frequency with a lower concentration of total TPTD administration in our setting, although the highest concentration also induced cortical porosity. Deconvolution fluorescence tiling imaging on calcein-labeled undecalcified bone sections also demonstrated the development of cortical porosity to be closely associated with the bone site where periosteal bone formation took place. This site-specific cortical porosity involved intracortical bone resorption and an increased number and proximity of osteocytic lacunae,occasionally causing fused lacunae. Taken together, these findings suggested the involvement of local distinctions in the rate of bone growth that may be related to the site-specific mechanical properties in the development of cortical porosity induced by frequent and/or high doses of TPTD.

New simulation model for bone formation markers in osteoporosis patients treated with once-weekly teriparatide

Daily 20-mg and once-weekly 56.5-mg teriparatide（parathyroid hormone 1–34） treatment regimens increase bone mineral density（BMD） and prevent fractures, but changes in bone turnover markers differ between the two regimens. The aim of the present study was to explain changes in bone turnover markers using once-weekly teriparatide with a simulation model. Temporary increases in bone formation markers and subsequent decreases were observed during once-weekly teriparatide treatment for 72 weeks. These observations support the hypothesis that repeated weekly teriparatide administration stimulates bone remodeling, replacing old bone with new bone and leading to a reduction in the active remodeling surface. A simulation model was developed based on the iterative remodeling cycle that occurs on residual old bone. An increase in bone formation and a subsequent decrease were observed in the preliminary simulation. For each fitted time point, the predicted value was compared to the absolute values of the bone formation and resorption markers and lumbar BMD. The simulation model strongly matched actual changes in bone turnover markers and BMD. This simulation model indicates increased bone formation marker levels in the early stage and a subsequent decrease. It is therefore concluded that remodeling-based bone formation persisted during the entire treatment period with once-weekly teriparatide.

The Novel cPLA2 Inhibitor AK106-001616 Has a Protective Effect on SOD1G93A-Induced Cell Death in NSC34 Murine Motor Neuron-Like Cell

The expression of cytosolic phospholipase A2 (cPLA2) expression is up-regulated in animal model of ALS and in patients with familial amyotrophic lateral sclerosis (fALS). Inhibition of cyclooxygenase 2 (COX2), which is a downstream enzyme of cPLA2, ameliorates the impairment of motor function in the ALS model mice. Therefore, the arachidonic acid cascade, including the cPLA2-COX2 pathway, is an important therapeutic target of ALS. The current study was designed to investigate the potential of AK106-001616, an inhibitor of cPLA2, in protection of motor neuron cell death induced by mutant superoxide dismutase (SOD1G93A). AK106-001616 (1 - 10 μM) protected NSC34 cells (mouse motor neuron like cells) against SOD1G93A-induced motor neuron cell death. Furthermore, aspirin, an inhibitor of COX1/2, reduced the SOD1G93A-induced motor neuron cell death at a concentration that inhibited COX2. Celecoxib, a selective COX2 inhibitor, also reduced the SOD1G93A-induced motor neuron cell death. These results suggest that the arachidonic acid cascade is important for SOD1G93A-induced motor neuron cell death and AK106-001616 has a potent neuroprotective effect against it. AK106-001616 may be a useful therapeutic agent against SOD1G93A-induced ALS.

法舒地尔对急性缺血性卒中的疗效:一项前瞻性安慰剂对照的双盲试验结果

Background: A multicenter, double-blind, placebo-controlled study was conducted to assess the efficacy and safety of fasudil, a Rhokinase inhibitor (RKI), in the treatment of acute ischemic stroke. Methods: A total of 160 patients, who were able to receive drug treatment within 48 h of acute ischemic stroke onset were enrolled. Patients received either 60 mg fasudil or a placebo (saline) by intravenous injection over 60 min, twice daily for 14 days. The primary end points were neurological status at 2 weeks after the start of treatment, and clinical outcome at 1 month after the onset of symptoms. Results: Fasudil treatment resulted in significantly greater improvements in both neurological functions (p = 0.0013), and clinical outcome (p = 0.0015). There were no serious adverse events reported in the fasudil group. The average trough value (12 h values)of active metabolite hydroxyfasudil, another RKI, in healthy elderl y volunteers receiving 60 mg of fasudil was 0.077 μM a concentration well above that needed to inhibit Rho-kinase (0.025-0.05 μM). Conclusion: Treatment wit h fasudil within 48 h of acute ischemic stroke onset significantly improved the patient’s clinical outcome. This study found fasudil to be a useful and safe dr ug for patients with acute ischemic stroke. Further evaluations, for example, 3 -month functional outcomes in a larger clinical trial, may help to define the e fficacy of fasudil in acute ischemic stroke.