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Biomedical subjects

M Aono

Publications and source records attributed to M Aono.

At least 145 records · Page 8Linked to original sources

In-vitro biosynthesis of sulphatoglycosphingolipids by rat submandibular salivary glands.

A sulphotransferase activity, concentrated mainly in the microsomal fraction, which catalyses the transfer of sulphate group from 3'-phosphoadenosine-5'-phosphosulphate to galactosylceramide and lactosylceramide was demonstrated in rat submandibular and sublingual glands. However, the sulphotransferase activity of this fraction in submandibular glands was about ten times higher than in sublingual glands. Optimum enzyme activity was obtained using the detergent Triton X-100, F-, and Mg2+ at a pH of 6.8. The enzyme did not catalyse the transfer of sulphate to glucosylceramide, trihexosylceramide and triglucosyl glyceroglucolipid. The sulphotransferase exhibited similar affinity for both galactosyl- and lactosylceramide. The apparent Km of the enzyme for galactosylceramide was 3.8 X 10(-5) M, and for lactosylceramide, 4.3 X 10(-5) M. The results of compositional analysis and periodate-oxidation studies of the 35S-labelled products of the enzyme reactions established that in both [35S]-sulphatoglycosphingolipids the sulphate-ester group is located at C-3 of the galactose residue.

Animals↗

Lipids of supragingival calculus.

The matrix of supragingival calculus constitutes 15.7% of the calculus dry weight and contains 54.9% protein and 10.2% lipids. Of the total lipids, 61.8% are represented by neutral lipids, 28% by glycolipids, and 10.2% by phospholipids. The neutral lipids exhibit a high content of free fatty acids (63.9%) and triglycerides (15.8%). The glycolipids are comprised of simple glycosphingolipids (17.2%), mainly lactosyl- and glucosylceramides, and of neutral and sulfated glyceroglucolipids (82.8%). The phospholipids contain large quantities of phosphatidylethanolamine (34.2%) and diphosphatidylglycerol (25.5%). Comparison with salivary and submandibular stone lipids indicates that both saliva and bacteria contribute to the lipid content of supragingival calculus.

Chromatography, Gas↗

Lipid composition of human parotid salivary gland stones.

The parotid gland stone matrix constitutes 20.2% of the stone dry weight and contains 8.5% of lipids. Of the total lipids, 74% are represented by neutral lipids, 17% by glycolipids, and 9% by phospholipids. The neutral lipids exhibit a high content of free fatty acids (52.7%) and cholesteryl esters (31.1%). The glycolipids are composed of simple glycosphingolipids (7.1%), and of neutral and sulfated glyceroglucolipids (92.9%). Phosphatidylethanolamine and diphosphatidylglycerol are the principal constituents of the phospholipid fraction.

Chromatography, Gas↗

Lipid composition of tracheobronchial secretions from normal individuals and patients with cystic fibrosis.

The lipid composition of tracheobronchial secretions from normal individuals and patients with cystic fibrosis was investigated. Lipids were extracted from he dialyzed and lyophilized samples, and fractionated on silicic acid columns into neutral lipids, glycolipids and phospholipids. The lipids contained each fraction were separated into individual components by thin-layer chromatography and quantified. The secretions of patients with cystic fibrosis and were found to contain about 30% more lipids than that of normal individuals and exhibited elevated levels of cholesterol, phospholipids and glycosphingolipids. The level of free fatty acids and glyceroglucolipids was higher in the normal secretions. The phospholipids of cystic fibrosis secretions exhibited higher content of sphingomyelin and phosphatidylserine, while the normal samples contained more lysophosphatidylcholine. The glycosphingolipids of both types of samples consisted mainly of glucosyl- and lactosylceramides. The major glyceroglucolipid of the normal tracheobronchial secretions was tetraglucosyl glyceroglucolipid, whereas hexa-and octaglucosyl glyceroglucolipids were the predominant compounds of the cystic fibrosis secretions.

Bronchi↗

Lipid composition of human parotid and submandibular saliva from caries-resistant and caries-susceptible adults.

The lipid content and composition of parotid and submandibular saliva from caries-resistant (DMFS of 0) and caries-susceptible (DMFS greater than 15) adults was investigated. Lipids were extracted from dialysed and lyophilized saliva, collected from 10 subjects in each group, and fractionated into neutral lipids, glycolipids and phospholipids. The lipids in each fraction were separated into individual components by thin-layer chromatography and quantitated. The parotid and submandibular saliva of caries-resistant subjects contained 37 and 35 per cent fewer lipids/100 ml of saliva than that of the caries-susceptible group, and had less (p less than 0.001) neutral lipids and phospholipids. The neutral lipids of caries-resistant saliva contained (mg/100 ml of saliva) considerably (p less than 0.001) fewer free fatty acids, triglycerides and cholesterol esters. The glycolipids consisted exclusively of glyceroglucolipids and their content was similar in both groups. The content of phospholipids in the salivas of the caries-resistant was 25 and 33 per cent lower than that of the caries-susceptible. The data suggest a relationship between the level of lipids in salivary secretions and resistance to caries.

Adult↗

Lipid composition of the matrix of human submandibular salivary gland stones.

The lyophilized stone matrix, prepared by exhaustive dialysis of pulverized stones against 10 per cent EDTA and water, yielded 9.6 +/- 0.9 mg per cent of lipids. Following fractionation of the lipid extract on silicic acid columns, 57 per cent of lipids were found in the neutral lipid fraction, 40 per cent in the glycolipid fraction and 3 per cent in the phospholipid fraction. Of the total neutral lipids, 77.3 per cent were represented by free fatty acids, 14.7 per cent by cholesterol, 4.1 per cent by triglycerides and 3.2 per cent by cholesterol esters. The glycolipid fraction was comprised of simple glycosphingolipids (11.3 per cent), mainly lactosyl- and glucosylceramides, and of neutral and sulphated glyceroglucolipids (88.7 per cent). The sulphated glyceroglucolipids consisted of tri- and tetraglucosyl glyceroglucolipids, whereas hexa- and octaglucosyl glyceroglucolipids were the predominant constituents of the neutral glyceroglucolipid fraction. The phospholipids exhibited a high content of sphingomyelin (22.3 per cent), phosphatidylcholine (12.1 per cent), phosphatidylethanolamine (11.4 per cent), phosphatidylserine (10.5 per cent) and lysophosphatidylcholine (13.3 per cent). The major fatty acids of the neutral lipid fraction were hexadecanoate, octadecanoate and octadecenoate. The glycolipids contained large quantities of hexadecanoate and tetracosanoate, while the hexadecanoate, octadecanoate and tetracosanoate were the principal fatty acids of the phospholipid fraction.

Adult↗

Lipid composition of submandibular saliva from normal and cystic fibrosis individuals.

The submandibular saliva of patients with cystic fibrosis was found to contain about 66% more lipids/100 ml of saliva than that of normal individuals and exhibited elevated levels of neutral lipids, phospholipids, and glycolipids. No significant differences were noted in the proportions of individual neutral lipid and phospholipid components present in both types of samples. The glycolipids of normal saliva consisted entirely of glyceroglucolipids, whereas those of cystic fibrosis saliva, in addition to glyceroglucolipids, also contained small amounts of glycosphingolipids. These quantitative and qualitative differences may affect the physicochemical properties of the secretion.

Adolescent↗