Chronic Hyponatremia Causes Neurologic and Psychologic Impairments

Hyponatremia is the most common clinical electrolyte disorder. Once thought to be asymptomatic in response to adaptation by the brain, recent evidence suggests that chronic hyponatremia may be linked to attention deficits, gait disturbances, risk of falls, and cognitive impairments. Such neurologic defects are associated with a reduction in quality of life and may be a significant cause of mortality. However, because underlying diseases such as adrenal insufficiency, heart failure, liver cirrhosis, and cancer may also affect brain function, the contribution of hyponatremia alone to neurologic manifestations and the underlying mechanisms remain unclear. Using a syndrome of inappropriate secretion of antidiuretic hormone rat model, we show here that sustained reduction of serum sodium ion concentration induced gait disturbances; facilitated the extinction of a contextual fear memory; caused cognitive impairment in a novel object recognition test; and impaired long-term potentiation at hippocampal CA3–CA1 synapses. In vivo microdialysis revealed an elevated extracellular glutamate concentration in the hippocampus of chronically hyponatremic rats. A sustained low extracellular sodium ion concentration also decreased glutamate uptake by primary astrocyte cultures, suggesting an underlying mechanism of impaired long-term potentiation. Furthermore, gait and memory performances of corrected hyponatremic rats were equivalent to those of control rats. Thus, these results suggest chronic hyponatremia in humans may cause gait disturbance and cognitive impairment, but these abnormalities are reversible and careful correction of this condition may improve quality of life and reduce mortality.     

Effect of oxygen inhibition of self-etching adhesives on enamel-dentin polymer bond

PURPOSE: To determine effects of light curing of self-etching adhesives under ambient air or nitrogen on inhibition depths, enamel and dentin bond strengths, and marginal adaptation in dentin cavities. MATERIALS AND METHODS: The adhesives investigated were: AQ Bond (AQB, Sun Medical; Kyoto, Japan), iBond (IBO, Heraeus Kulzer; Hanau, Germany), One-Up Bond F II (OUB, Tokuyama; Tokyo, Japan), and Prompt L-Pop (PLP, 3M/ESPE; Seefeld, Germany). Inhibition layer thickness (ILT) was microscopically measured on 3 disk-shaped specimens each. Shear bond strengths (SBS) on enamel and dentin (n = 8) were determined after 10 min and 24 h water storage of bonded composite specimens (Venus, Heraeus Kulzer). The marginal adaptation of bonded Venus restorations in cylindrical dentin cavities was microscopically evaluated after 10 min of specimen storage (n = 8) in water. The data were statistically analyzed using parametric and nonparametric ANOVA and post-hoc tests at p < 0.05. RESULTS: Adhesive curing under air revealed significant ILT (microm) differences: IBO (4) < AQB (8) < PLP (12) < OUB (23). Upon curing in nitrogen atmosphere, no inhibition occurred with AQB, IBO, and PLP, and < 3 microm for OUB. SBSs on enamel after 10 min or 24 h did not differ according to curing atmospheres (p > 0.05). On dentin, SBSs were higher after curing under N2 (p < 0.05). Irrespective of the curing atmosphere, marginal adaptation was good for AQB and IBO and poor for PLP; OUB revealed significantly smaller gaps under N2 than under air curing. CONCLUSION: Oxygen inhibition of the four self-etching adhesives investigated had no or only moderate effects on bonding efficacy to enamel and dentin.     

Condylar movements of temporomandibular disorder patients with intermittent lock: a pilot study

The purpose of this study was to clarify which direction of the condylar path is advantageous for releasing TMJ intermittent lock. The subjects were ten patients with temporomandibular disorders (TMD) and intermittent lock caused by anterior displacement of disks without obvious medial or lateral displacement. The patients could not open their mouths fully in habitual opening but could open fully in an intentional winding opening with reduction of the anteriorly displaced disks (winding opening). The two kinds of movement at the kinematic condylar point were measured in each subject and compared. The length of the condylar path in winding opening was significantly larger than that in habitual opening. The affected side condyle of winding opening traced medio-inferior paths in the early part of the condylar translation in comparison with habitual opening. From the viewpoint of the condylar path, the medio-inferior direction of condylar translation is thought to be advantageous for releasing intermittent lock.     

Protein-bound polysaccharide K induced apoptosis of the human Burkitt lymphoma cell line, Namalwa.

Protein-bound polysaccharide K (PSK), which is derived from mushrooms belonging to the Basidiomycetes genus, has been clinically used as a biological response modifier (BRM) for the treatment of epithelial cancer patients in Japan and other Asian countries. There are a large number of studies on the biological activities of PSK as regards the activation of immunocompetent cells and the potential cytotoxic effects on epithelial cancer cells. However, only a few studies have been conducted to see the direct cytotoxic effects of PSK on hematological malignant cells. In this study, we investigated whether or not PSK was able to induce cellular apoptosis in hematological malignant cells. PSK was found to inhibit cell growth, and induced subsequent cellular apoptosis in the Burkkit lymphoma cell line (Namalwa), out of 33 hematological malignant cell lines tested. This PSK-induced apoptosis was neutralized by the addition of galactose to the culture medium, whereas apoptosis was augmented by treatment with beta-galactosidase, indicating the inhibitory involvement of galactose in the mechanism of action. These results provide initial evidence of the direct cytotoxic activity of PSK in a hematological malignant cell line, thus encouraging further molecular-level study of PSK-mediated apoptosis in malignant hematological cells.     

TRPV2 Promotes Cell Migration and Invasion in Gastric Cancer via the Transforming Growth Factor-β Signaling Pathway

Annals of Surgical Oncology - Transient receptor potential vanilloid 2 (TRPV2) is a highly Ca2+-permeable ion channel that is involved in a number of cellular processes. It is expressed in various...