The Ulnar Nerve at Elbow Extension and Flexion: Assessment of Position and Signal Intensity on MR Images.

Purpose To assess the position and signal intensity of the ulnar nerve at elbow extension and flexion by using magnetic resonance imaging. Materials and Methods Institutional review board approval and written informed consent were obtained. Transverse T2-weighted images were obtained perpendicular to the upper arm in 100 healthy elbows of 50 volunteers (23 men, 27 women; age range, 21-57 years) and nine elbows with ulnar neuropathy (five men, four women; age range, 24-59 years) with extension and 130° of flexion. Ulnar nerve position was classified into three types: no dislocation, subluxation, or dislocation. One-way analysis of variance, paired t tests, Student t tests, and multiple regression analysis were used to analyze correlations between ulnar nerve movement angle during flexion and age, sex, presence of the anconeus epitrochlearis muscle, and ulnar neuropathy and to compare the contrast-to-noise ratio of nerve to muscle between extension and flexion. Results Nerve positions in healthy elbows were as follows: All had no dislocation at extension, and at flexion, 51 of 100 elbows (51.0%) had no dislocation, 30 of 100 elbows (30.0%) had subluxation, and 19 of 100 elbows (19.0%) had dislocation. Nerve movement angle was smaller in elbows with the anconeus epitrochlearis muscle than in those without the muscle (P = .045, .015). Presence of the muscle was the only significant factor associated with nerve movement angle (P = .047, .013). Only dominant elbows with nerve movement angle of less than 15° and nondominant elbows with nerve movement angle of less than 10° showed contrast-to-noise ratio increase at flexion (P = .021-.030). Conclusion Ulnar nerve movement during flexion was apparent in approximately half of healthy elbows and was similar between healthy elbows and elbows with ulnar neuropathy. Nerve signal intensity increased during flexion only in elbows without apparent nerve movement. (©) RSNA, 2016 Online supplemental material is available for this article.

Protecting group free synthesis of urea-linked glycoconjugates: efficient synthesis of ß-urea glycosides in aqueous solution.

A method for the protecting group free synthesis of ß-urea-linked glycoconjugates has been developed. The one step process, involving reactions between urea and D-glucose, N-acetyl-D-glucosamine or D-xylose in acidic aqueous solution, furnishes the corresponding ß-urea glycosides in modest yields. This simple and efficient procedure is applicable to the synthesis of ß-urea tethered amino acid-carbohydrate conjugates.

Lipids in human parotid saliva with regard to caries experience.

It has been reported that saliva may play an important role in the prevention and development of enamel caries and that both lipids and protein contents in saliva may be relevant to this role. This study examined the lipid and protein levels in saliva from individuals differing in caries experience. Female subjects (20 to 21 years old) were used divided equally into two groups, caries-susceptible group (CSG) and caries-resistant group (CRG). Stimulated parotid saliva and stimulated whole saliva were collected from the subjects. After centrifugation, each saliva sample was analyzed for the concentrations of lipids and proteins and for the compositions of lipids and fatty acids. The lipid and protein contents in parotid saliva increased in proportion to increase of the flow rate. The lipid content was slightly correlated with the protein one (r = 0.33). Total lipid and protein concentrations were higher in the samples from CSG than those from CRG. The lipid composition was similar in the samples from the two groups; more than half in total lipids was neutral lipids, followed by glycolipids and phospholipids. Neutral lipids and free fatty acid and triacylglyceride concentrations were significantly higher in the samples from CSG than those from CRG (p<0.01 for each). Also stearic, linoleic and docosahexaenoic acids were significantly higher in the former group than the latter one (p<0.05 and p<0.01). In summary, the lipid concentrations in parotid saliva from caries susceptible subjects were higher than those from caries resistant ones, and the difference in fatty acid composition was detected between them. The variations in the lipid levels and fatty acid composition may be associated with those in caries development.

Phospholipid profiles in the salivary glands of rats of different ages.

It has been reported that diabetes and Sjögren's syndrome patients exhibit variations in the amount of salivation and in the lipid components in saliva and salivary glands. We examined whether lipid compositions, especially phospholipid ones in the salivary glands of rats varied with aging. We analyzed phospholipid and fatty acid compositions in the salivary glands of young (5 to 6 weeks), adult (20 weeks), and old (50 weeks) rats and biochemical components in their blood. The aging (adult and old) rats had higher triacylglycerol, total lipid, total cholesterol and glucose contents in the plasma than the young one. The aging ones also had higher total lipid contents in the major salivary glands (parotid, submandibular and sublingual glands). They had higher wet weights of the major salivary glands and epididymal fat pads than the young ones, but had lower ratios of the major salivary glands to body weight. All of them had high phospholipid contents in the parotid and submandibular glands as compared to sublingual gland, but the aging ones had lower percentage of phospholipid contents of all salivary glands. Phosphatidylcholine and phosphatidylethanolamine were predominant among the phospholipids in the major salivary glands, and little difference was observed in phospholipid composition among the three groups. Palmitic and stearic acids (saturated acids), and linoleic, oleic and arachidonic acids (unsaturated acids) were major components of fatty acids of phospholipids in the major salivary glands. The aging ones had higher linoleic and lower arachidonic acid contents in the glands than the young one. In summary, the aging rats had higher total lipid contents than the young ones and had lower phospholipid contents of the major salivary glands. The n-6 fatty acid contents differed between aging and young ones. The results suggest that phospholipids in the major salivary glands change with the development of rat.

Potential role for astroglial D-amino acid oxidase in extracellular D-serine metabolism and cytotoxicity.

D-amino acid oxidase (DAO) is a flavoenzyme that catalyzes the oxidation of D-amino acids. In the brain, gene expression of DAO is detected in astrocytes. Among the possible substrates of DAO in vivo, D-serine is proposed to be a neuromodulator of the N-methyl-D-aspartate (NMDA) receptor. In a search for the physiological role of DAO in the brain, we investigated the metabolism of extracellular D-serine in glial cells. Here we show that after D-serine treatment, rat primary type-1 astrocytes exhibited increased cell death. In order to enhance the enzyme activity of DAO in cells, we established stable rat C6 glial cells overexpressing mouse DAO designated as C6/DAO. Treatment with a high dose of D-serine led to the production of hydrogen peroxide (H(2)O(2)) followed by apoptosis in C6/DAO cells. Among the amino acids tested, D-serine specifically exhibited a significant cell death-inducing effect. DAO inhibitors, i.e., sodium benzoate and chlorpromazine, partially prevented the death of C6/DAO cells treated with D-serine, indicating the involvement of DAO activity in d-serine metabolism. Overall, we consider that extracellular D-serine can gain access to intracellular DAO, being metabolized to produce H(2)O(2). These results support the proposal that astroglial DAO plays an important role in metabolizing a neuromodulator, D-serine.