METHODS: Systemic examination of bulbar signs was carried out according to a predetermined protocol on a cohort of young and elderly healthy subjects.
RESULTS: A total of 206 subjects were recruited in the study, 104 young adults with mean age of 20 years, and 102 elderly with mean age of 73 years. Uvula deviation was seen in 28 (26.9%) young subjects and 22 (21.6%) elderly. Irregular tongue border was seen in 17 subjects, unilateral in 4 subjects. Fourteen (6.8%) subjects had deviation on tongue protrusion. Occasional tremor of tongue on protrusion is common in both young and old. Persistent (severe) tongue tremor on protrusion was seen in 18.6% of the elderly, and 4.8% of the young. None of the subjects had tremor of tongue at rest. In gag reflex, absence of gagging response was common in elderly, seen in two thirds of the subjects on stimulation of the posterior pharyngeal wall. However, all the subjects had uvular movement. Habituation or suppression of gagging response was seen in close to 90% of young males.
CONCLUSION: There is wide range of normality in bulbar signs in normal population, particularly among the elderly.
METHODS: PEPT2 polymorphisms were screened from a cohort of 96 Chinese, 96 Malay and 96 Asian Indian subjects. Cephalexin (1000 mg, orally) pharmacokinetics was characterized in an additional 15 Chinese and 15 Asian Indian healthy subjects. These 30 subjects were subsequently genotyped for their PEPT2 polymorphisms.
RESULTS: In total, ten common single nucleotide polymorphisms (SNPs) were detected in the three populations, forming two PEPT2 haplotypes. There were significant ethnic differences in PEPT2 haplotype distribution: the frequencies of the *1 and *2 alleles were 0.307 and 0.693 in the Chinese population, 0.495 and 0.505 in the Malay population and 0.729 and 0.271 in Asian Indian population, respectively. The C (max) of cephalexin was significantly lower in the Chinese (29.80 +/- 4.09 microg ml(-1)) population than in the Asian Indian one (33.29 +/- 4.97 microg ml(-1); P = 0.045). This difference could be explained by the higher average body weight of the Chinese population. There was no other significant difference in cephalexin pharmacokinetics between either ethnic or PEPT2 genotype groups.
CONCLUSION: PEPT2 polymorphism distributions differ significantly between Chinese, Malay and Asian Indian populations. However, cephalexin pharmacokinetics is not meaningfully different between Chinese and Asian Indians. The association between the PEPT2 haplotype and cephalexin pharmacokinetics could not be confirmed, and future studies under better controlled conditions are needed.