Fatigue and tensile properties of radicular dentin substrate.

The purpose of this study was to compare the fatigue and tensile strengths of radicular dentin. Forty bovine lower central incisors were used, twenty teeth for the fatigue test and twenty teeth for the tensile test. Bovine teeth were each sectioned into coronal and radicular portions.

Physicochemical and pharmacological characterization of alpha-tocopherol-loaded nano-emulsion system.

The main purpose of the present study is to develop a novel nano-emulsion (NE) formulation of alpha-tocopherol (alpha-TC) with enhanced oral bioavailability and pharmacological effects. Three NE formulations of alpha-TC at different loading amounts (10%, 30% and 50%) were prepared by a mechanochemical method. Physicochemical properties of NE formulations were characterized with a focus on the morphology by transmission electron microscopy (TEM), droplet size distribution and zeta-potential by dynamic light scattering (DLS), and long-term stability.

Novel crystalline solid dispersion of tranilast with high photostability and improved oral bioavailability.

Tranilast (TL) is an anti-allergic agent and widely used in the clinical treatment of bronchial asthma, atopic rhinitis, atopic dermatitis and keloids. However, therapeutic potential of TL could be partly limited because of its poor solubility, bioavailability, and photostability. To overcome these drawbacks, crystalline solid dispersion of TL (CSD/TL) was prepared by wet-milling technique with aim of improving physicochemical and pharmacokinetic properties.

Liposomal formulations of glucagon-like peptide-1: improved bioavailability and anti-diabetic effect.

Glucagon-like peptide-1 (GLP-1), an incretin hormone, is recognized to be potent drug candidate for treatment of diabetes, however its clinical application has been highly limited, because of rapid enzymatic degradation by dipeptidyl-peptidase IV. To protect GLP-1 from enzymatic degradation and improve pharmacological effects, liposomal formulations of GLP-1 were prepared using three types of lyophilized empty liposomes such as anionic, neutral and cationic liposomes. Electron microscopic and dynamic light scattering experiments indicated the uniform size distribution of GLP-1-loaded liposomes with mean diameter of 130-210 nm, and inclusion of GLP-1 did not affect the dispersibility and morphology of each liposome.

Comparison of nanohardness between coronal and radicular intertubular dentin.

This study investigated the hardness and Young's modulus of coronal and radicular intertubular dentin. Ten bovine teeth were each divided into coronal and radicular groups, and the flat surfaces of the coronal and radicular dentin were subsequently processed along the tooth axis. The hardness and Young's modulus of the coronal and radicular intertubular dentin were evaluated using nanoindentation tests, at two locations per tooth.

Is increased fat content of hindmilk due to the size or the number of milk fat globules?

Background: It is known that the fat content of breast milk is higher in hindmilk than in foremilk. However, it has not been determined if this increased fat content results from an increase in the number of milk fat globules (MFGs), an increase in the size of MFGs, or both. This study aims to determine which factor plays the most important role.

Fine structure and mineral components of primary calculi in some human prostates.

The fine structure of prostatic calculi has not been elucidated yet, although the chemical components were reported in detail. We studied the primary or endogenous calculi removed from eight human prostates by secondary scanning electron microscopy, backscattered electron imaging, energy-dispersive X-ray microanalysis and X-ray diffraction. The primary calculi containing Mg, Zn and S, besides Ca and P were basically classified into four stone groups (I-IV) by fine structure and mineral components.

Structural transition of glucagon in the concentrated solution observed by electrophoretic and spectroscopic techniques.

Glucagon, a polypeptide hormone consisting of 29 amino acid residues, tends to form gel-like fibrillar aggregates, and the glucagon fibril, as well as other pathologically related fibrils including prion, amylin, and beta-amyloid, have been found to be cytotoxic through the activation of apoptotic signaling pathways. To understand the aggregation properties of glucagon fibril, we have characterized and compared the physicochemical properties of glucagon, secretin, a member of the glucagon superfamily, and amylin using analytical techniques including capillary electrophoresis (CE), circular dichroism (CD), FT-IR, FT-Raman, transmission electron microscopy (TEM), and beta-sheet-imaging probe. Aging treatment of glucagon resulted in the formation of fibrillar aggregates in time- and concentration-dependent manner, and FT-IR and FT-Raman analyses showed the spectral shift of amide I band, suggesting the conformational changes from alpha-helix to beta-sheet structure.

Mishandling of the therapeutic peptide glucagon generates cytotoxic amyloidogenic fibrils.

Purpose: Some therapeutic peptides exhibit amyloidogenic properties that cause insolubility and cytotoxicity against neuronal cells in vitro. Here, we characterize the conformational change in monomeric therapeutic peptide to its fibrillar aggregate in order to prevent amyloidogenic formation during clinical application.

Methods: Therapeutic peptides including glucagon, porcine secretin, and salmon calcitonin were dissolved in acidic solution at concentrations ranging from 1 mg/ml to 80 mg/ml and then aged at 37 degrees C.

Specific biological functions of vacuolar-type H(+)-ATPase and lysosomal cysteine proteinase, cathepsin K, in osteoclasts.

We report the effects of specific and potent inhibitors of vacular-type H(+)-ATPase and lysosomal cysteine proteinases, cathepsins, on the ultrastructure, expression of these enzymes, and resorptive functions of cultured osteoclasts. Osteoclasts were formed by co-culture of marrow cells and calvarial primary osteoblasts of ddY mice. Formed osteoclasts were cultured on dentine slices for 6-48 hr with either an H(+)-ATPase inhibitor, bafilomycin A1, or a cysteine proteinase inhibitor, E-64.

Scanning electron microscopy and energy-dispersive X-ray microanalysis studies of afibrillar cementum and cementicle-like structures in human teeth.

We examined afibrillar cementum (AFC) and cementicle-like structures (CLS) in human teeth by scanning electron microscopy and energy-dispersive X-ray microanalysis. The AFC showed a spur- or island-, plate- and mass-like structure with appositional laminations, while large masses in the enamel fissures enclosed CLS showing concentric appositional rings. Such AFC was observed in enamel fissures, an abnormal enamel pit, dens invaginatus and root furcations with enamel droplets, as well as on the cervical enamel surfaces, where ameloblasts are differentiated at the later or last stage of enamel formation.

Effects of enamel matrix derivative to titanium implantation in rat femurs.

The effects of enamel matrix derivative (EMD; Emdogain) on new trabecular bone induction after pure bioinert titanium (Ti) implantation in the rat femur were examined by means of routine light and transmission electron microscopy, immunohistochemistry, and backscattered electron image analysis. Newly designed mini-Ti implants (3.5 mm in length and 1.