Lipids of developing dental plaque in caries-resistant and caries-susceptible adult people

Dental plaque maturation in both caries-resistant (CR) and caries-susceptible (CS) subjects was accompanied by a decrease in total lipid content but was more pronounced with CR subjects; their plaque after 72 h contained 44.6 per cent less lipids than that of CS. At each stage of maturation, differences were also found in the proportion of lipid classes. In 24 h-plaque, the lipids of CR-group, although containing amounts of glycolipids and phospholipids similar to those of CS, contained 1.6 times less neutral lipids. The 48 h-plaque of CS subjects showed 2.5 times more neutral lipids, 1.2 times more phospholipids and 1.4 times less glycolipids. The 72 h-CR plaque contained 1.9 times less neutral lipids, 1.6 times more glycolipids and 1.3 times more phospholipids than CS-plaque. Among the neutral lipids in both groups, the changes with maturation were associated with decrease in free fatty acids and increase in triglycerides, cholesterol and cholesteryl esters. Phospholipids of CR-plaque contained less phosphatidylcholine and more phosphatidylethanolamine than CS-plaque. With plaque maturation both groups showed decreases in the glycolipids characteristic of saliva and an increase in the content of bacterial type of glycolipids. Plaque maturation is evidently accompanied by dynamic changes in lipids reflecting a shift from salivary to bacterial contribution.     

Tooth surface-pellicle lipids and their role in the protection of dental enamel against lactic-acid diffusion in man

The lipid content and composition of the enamel pellicle from caries-resistant (CR) and caries-susceptible (CS) subjects and their effect on its ability to retard the diffusion of lactic acid were investigated. Lipids accounted for 22.2 per cent of the dry weight of CR pellicle and 23.7 per cent of CS pellicle. The content of glycolipids in both groups was similar but CR pellicle contained 42 per cent less neutral lipids and 31 per cent less phospholipids. CR lipids had a higher content of cholesterol, cholesterol esters and sphingomyelin, whereas CS pellicle was richer in free fatty acids and phosphatidylethanolamine. Retardation of lactic-acid diffusion by CR pellicle was 45 per cent higher than by CS. Removal of lipids caused 50 per cent reduction in retardation by CR pellicle and 35 per cent by CS pellicle.     

Postaural apocrine hydrocystoma

Benign apocrine hydrocystoma is a rare lesion, especially in the postauricular region, the commonest site being the lateral orbital rim. It is a slow growing, asymptomatic transluscent swelling whose definitive diagnosis can only be made by histopathological study and the chemical analysis of the fluid. Surgical excision in toto is the treatment of choice. A case of benign apocrine hydrocystoma in the postauricular region is described with review of relevant literature.     

Variation and inheritance of relative length of index finger in man

The length of index finger relative to fourth finger has been measured on parents and children in 190 families belonging to an endogamous Reddy community of Nalgonda District, India. The distribution of relative index finger length among various family groups was unimodal and symmetric. Heritability estimates based on parent-offspring regressions indicate a moderate level (40--70 percent) of additive genetic variance. There was no evidence for the influence of sex-linked additive genes.     

Endoscopic sphenopalatine ganglion block for pain relief

The anaesthetic effect of the sphenopalatine (SPG) block has been well utilized for intranasal topical anaesthesia but the analgesic efficacy of (SPG) block, though well documented in literature, has not been put into practice. The methods available for SPG block till date were blind as they do not visualize the foramen. Nasal endoscopies have been used to visualize the foramen for an effective block. The authors present their experience with the endoscopic sphenopalatine ganglion block for pain relief in head and neck malignancies and neuralgias.     

Ethnic differences in contraceptive use in Sri Lanka

In Sri Lanka in 1975, the majority Sinhalese had a much higher use of contraception than either the Sri Lanka Tamils or the Moors. This study uses a national sample of women of childbearing age gathered by the Sri Lanka World Fertility Survey in 1975 to assess four possible reasons for differential contraceptive use: (1) differences in socioeconomic position; (2) cultural differences; (3) minority status; and (4) differential access to family planning services. The first three explanations focus on differences in the demand for contraception while the fourth explanation focuses on differences in the availability of contraceptives. The socioeconomic, cultural, and minority status hypotheses fail to explain the higher contraceptive use among the Sinhalese. The evidence is consistent with the idea that ethnic differences in contraceptive use were largely caused by differential access to family planning services.     

Drug use in college students: a test of sociodemographic and reference group models of explanation.

This study examined the importance of reference group variables in the understanding of drug use in college students. Other studies have investigated the role of peer orientation, and this study further elaborates on the issue by specifically looking into parents and peers as reference groups for the students. This study supports the importance of reference group variables in understanding the students' use of marijuana and/or hashish. In addition, it shows that the sociodemographic variables cannot predict drug use behavior as well as the reference group variables can.