Where will the genome lead us? Dentistry in the 21st century.

BACKGROUND: Recent announcements of the deciphering and analysis of the human genome signal the inception of a new era of gene-based medicine. During the 21st century, patient treatment will be transformed and dentistry will be affected profoundly. METHODS: The author explains the importance of the decoding of the genome and how--based on this now completely depicted molecular structure--genes build, maintain and control all the biological functions of humans and all other living organisms. The potential application of this knowledge to the practice of dentistry is addressed, as well as the ethical, legal and moral challenges to the profession engendered by this new technology. CONCLUSION: During the next several decades, many of the current materials and methods will be abandoned in favor of emerging bioengineered technologies, genetically programmed for the prevention and treatment of oral disease as well as for the repair of damaged dental tissues. PRACTICE IMPLICATIONS: The development and implementation of these innovative dental therapies will require intensive education of current practitioners. Considerable restructuring of dental school curricula will need to take place, and the emergence of a new dental specialty is anticipated.

Early return to REM sleep after nocturnal awakening in depression.

Sixteen male outpatients with major depression and 20 age-equated healthy controls were awakened from rapid eye movement (REM) sleep between 1:30 and 3:30 AM, and the rapidity of return to REM sleep was determined. The time it took to return to REM sleep was reduced in depressives compared with controls: 61.6 (17.9 SD) min versus 80.6 (24.9 SD) min, respectively (p = 0.01). The time elapsed until the return to REM sleep was significantly correlated with baseline REM latency in controls (but not depressives). In contrast, return to REM time was significantly correlated with depression severity scores in depressives (but not controls). There was no evidence to support the hypothesis that the more rapid return to REM sleep in depression was caused by a slow wave sleep deficit. The mechanism underlying the rapid return of REM sleep in depression thus may be related to a severity-linked disturbance, such as a proposed increase in REM "pressure."

Quantification of subjective sleep quality in healthy elderly men and women using the Pittsburgh Sleep Quality Index (PSQI)

Subjective sleep quality deteriorates with aging, but the extent to which this is a product of age itself, as opposed to the medical or psychiatric problems associated with aging, has not been carefully studied. To investigate this issue, we examined the subjective sleep quality of 44 healthy subjects over 80 years of age (20 men, 24 women), and 35 healthy subjects [corrected] between the ages of 20 and 30 (23 men, 12 women) using the Pittsburgh Sleep Quality Index (PSQI). All subjects underwent rigorous medical and psychiatric evaluations to verify that they were in excellent physical and psychological health. Significant age effects were noted for the global PSQI score and several PSQI component scores, but overall sleep quality for the majority (68.1%) of 80-yr-olds fell within a categorically defined range for "good" sleepers. Measures of habitual sleep quality did not correlate strongly with most polysomnographic sleep measures, number of medications used or circadian measures in elderly subjects. These results show that subjective sleep quality does deteriorate in the healthy elderly, but not to the level seen in patients with sleep disorders. Extremely healthy elderly subjects appear to adapt in their perception of objectively disturbed sleep.

Sleep disturbances in survivors of the Nazi Holocaust.

OBJECTIVE AND METHOD: Sleep disturbances are commonly reported by victims of extraordinary stress and can persist for decades. This study was designed to test the hypothesis that survivors of the Nazi Holocaust would have significantly more and different sleep problems than depressed and healthy comparison subjects and that the severity of the survivors' problems would be correlated with length of time spent in a concentration camp. Forty-two survivors, 37 depressed patients, and 54 healthy subjects of about the same age, all living in the community, described their sleep patterns over the preceding month on the Pittsburgh Sleep Quality Index, a self-rating instrument that inquires about quality, latency, duration, efficiency, and disturbances of sleep, use of sleep medication, and daytime dysfunction. RESULTS: The survivors had significantly greater sleep impairment than the healthy comparison subjects, as measured by all subscales of the index, but had less impairment than the depressed patients except on the sleep disturbances and daytime dysfunction subscales. However, for specific items within these subscales, survivors had significantly more frequent awakenings due to bad dreams and had less loss of enthusiasm than the depressed subjects. Sleep disturbances and frequency of nightmares were significantly and positively correlated with the duration of the survivors' internment in concentration camps. CONCLUSIONS: These findings suggest that for some Holocaust survivors, impaired sleep and frequent nightmares are considerable problems even 45 years after liberation.

S-mephenytoin 4-hydroxylation in older Americans.

To examine whether a drug-metabolizing enzyme changes with normal aging, the S:R index of S-mephenytoin 4-hydroxylation was determined in 150, unmedicated elderly Americans (mean age 75.4). Ten (6.7%) were identified as categorically slow metabolizers (S:R ratios greater than or equal to .95). This increased incidence of slow metabolizers was accounted for by a significant and previously unreported, increased proportion of slow metabolizers among the black (18.5%) as compared to the white subjects (4.1%) (P = .017). There was no relationship found between S:R ratios and age or creatinine clearance.

Comparison of sleep-disordered breathing among healthy elderly in the seventh, eighth, and ninth decades of life.

We investigated the prevalence of sleep-disordered breathing (SDB) in healthy 80 year-old subjects (n = 38) as compared with healthy 70-(n = 33) and 60-year-old subjects (n = 34). The apnea-hypopnea index (AHI) increased significantly across decades: 39.5% (15 of 38) of 80 year olds, 33.3% (11 of 33) of 70 year olds, and 2.9% (1 of 34) of 60 year olds had an AHI greater than or equal to 5 (chi 2 = 14.0, p less than 0.001). The prevalence of SDB as measured by a more stringent apnea index criterion of greater than or equal to 5 was 18.9% of those in their 80s, 12.1% in their 70s, and 0% in their 60s (chi 2 = 6.63, p less than 0.05). Significant gender differences were noted in the proportion of subjects with AHI greater than or equal to 10: 22.4% of men versus 5.4% of women (chi 2 = 4.25, p less than 0.05). These data suggest that SDB increases with advancing age even in the healthy elderly and may be more marked in healthy men than women.