A biological study establishing the endotoxin limit of biomaterials for bone regeneration in cranial and femoral implantation of rats.

The purpose of this study was to accurately quantify the risk of endotoxin contamination in biomaterials for bone regeneration in order to establish the acceptable endotoxin limit. Collagen sheets containing varying amounts of purified endotoxin from Escherichia coli and dried, heat-killed E. coli or Staphylococcus aureus cells were implanted into cranial or femoral defects in rats.

Protective effects of (6R)-5,6,7,8-tetrahydro-l-biopterin on local ischemia/reperfusion-induced suppression of reactive hyperemia in rat gingiva.

We herein investigated the regulatory mechanism in the circulation responsible for rat gingival reactive hyperemia (RH) associated with ischemia/reperfusion (I/R). RH was analyzed using a laser Doppler flowmeter. RH and I/R were elicited by gingival compression and release with a laser Doppler probe.

Contribution of nitrergic nerve in canine gingival reactive hyperemia.

Reactive hyperemia reflects a compensatory vasodilation response of the local vasculature in ischemic tissue. The purpose of this study is to clarify the mechanism of regulation of this response in gingival circulation by using pharmacological analysis of reactive hyperemia and histochemical analysis of gingival tissue. Application of pressure to the gingiva was used to create temporary ischemia, and gingival blood flow was measured after pressure release.

Reactive oxygen species scavenging activity of Jixueteng evaluated by electron spin resonance (ESR) and photon emission.

Jixueteng, the dried stem of Spatholobus suberectus Dunn (Leguminosae), is a traditional Chinese herbal medicine that is commonly classified as a herb that promotes blood circulation and can be used to treat blood stasis. The aim of this study was to examine the reactive oxygen species (ROS) scavenging activity of Jixueteng and other herbal medicines. The ROS scavenging activities of the water extracts of Jixueteng, Cnidium officinale and Salvia miltiorrhiza were examined using an electron spin resonance (ESR) technique and faint luminescence measurement.

Gingival vascular functions are altered in type 2 diabetes mellitus model and/or periodontitis model.

The association of vascular reactivity between diabetes and periodontal disease has not been clarified. Gingival blood flow was measured by laser Doppler flowmetry for 31 weeks in Wistar rats, Wistar rats orally challenged with Porphyromonas gingivalis (Wistar rats + Porphyromonas gingivalis), Goto-Kakizaki rats, and Goto-Kakizaki rats orally challenged with Porphyromonas gingivalis (Goto-Kakizaki rats + Porphyromonas gingivalis). Effects of alveolar bone resorption on periodontal tissue was enhanced in Wistar rats + Porphyromonas gingivalis, and Goto-Kakizaki rats, with this effect being significantly enhanced by Goto-Kakizaki rats + Porphyromonas gingivalis.

Inhibitory effects of Jixueteng on P. gingivalis-induced bone loss and osteoclast differentiation.

Objective: The aim of this study was to investigate the possibility of Jixueteng as a preventive and therapeutic drug for the periodontitis. We investigated the inhibitory effects of Jixueteng on Porphyromonas gingivalis-induced bone loss in mice, antibacterial activity against P. gingivalis and differentiation of osteoclast and viability of cells.

Direct assessments of the antioxidant effects of propofol medium chain triglyceride/long chain triglyceride on the brain of stroke-prone spontaneously hypertensive rats using electron spin resonance spectroscopy.

Background: Antioxidant anesthetics such as propofol (2,6-diisopropylphenol) directly inhibit lipid peroxidation via the generation of reactive oxygen species. Currently, there are no other studies regarding the direct effects of propofol medium chain triglyceride/long chain triglyceride (MCT/LCT) on reactive oxygen species generation or in experimental models of reactive oxygen species-induced oxidative stress in the brain.

Methods: The authors investigated the effects of propofol MCT/LCT on reactive oxygen species (hydroxyl radical or superoxide) by electron spin resonance spin trapping with 5,5-dimethyl-1-pyrroline-N-oxide.

Co-treatment with basic fibroblast growth factor and 17beta-estradiol in the presence of dexamethasone accelerates bone formation by rat bone marrow stromal cell culture.

Purpose: Bone marrow stromal cells (BMSCs) are a promising cell source in applications for tissue engineering and regenerative medicine. Optimization and control of the growth and differentiation of cultivated cells can be achieved by the administration of growth factors and hormones in vitro. This study provided experimental information on the enhancement of the osteogenic potential of rat BMSCs in vitro and in vivo.

Nitric oxide levels in rat hypothalamus are increased by restraint stress and decreased by biting.

Mastication, which includes biting, is of great importance not only for the intake of food but also for the mental, physical and physiological functioning of the body. For example, biting suppresses the stress response. Although biting and nitric oxide (NO) appear to modulate brain dynamics during stress, the underlying mechanisms have not been elucidated.

Real-time monitoring of nitric oxide in ischemic myocardium using an NO-selective electrode calibrated by electron spin resonance.

Using a Langendorff-perfused rat heart preparation and selective electrodes, we determined nitric oxide (NO) and oxygen levels in cardiac tissue. An NO-selective electrode that was calibrated by electron spin resonance (ESR) spectroscopy was inserted into the middle of the myocardium in the left ventricle. Simultaneously, we used an O2-selective electrode to measure the partial pressure of oxygen (pO2) in the perfusate, Krebs-Henseleit (K-H) solution, that was ejected from the heart.

Role of nitric oxide in post-ischemic gingival hyperemia in anesthetized dogs.

The possible involvement of nitric oxide (*NO) in the preservation of blood flow to the canine gingiva after compression of gingival tissue was studied. Gingival blood flow, gingival tissue oxygen partial pressure (PO2), external carotid arterial blood pressure and external carotid arterial blood flow were monitored before, during, and after compression of gingival tissue in the presence and absence of the nitric oxide synthase inhibitor, Nomega-nitro-L-arginine-methyl-ester (L-NAME). Compression of gingival tissue resulted in an immediate decrease in gingival blood flow and tissue PO2.

Endothelium-dependent vasorelaxation induced by black currant concentrate in rat thoracic aorta.

We investigated the effect of black currant (BC) concentrate on smooth muscle in rat thoracic aorta. BC concentrate dose-dependently relaxed the norepinephrine (0.1 microM)-precontracted aorta, and the response was abolished after endothelium removal.