Faculty Bibliography

The associations of inflammation/immune responses with clinical presentations of Alzheimer's disease (AD) remain unclear. We hypothesized that TNF-alpha and elevated antibodies to periodontal bacteria would be greater in AD compared to normal controls (NL) and their combination would aid clinical diagnosis of AD. Plasma TNF-alpha and antibodies against periodontal bacteria were elevated in AD patients compared with NL and independently associated with AD. The number of positive IgG to periodontal bacteria incremented the TNF-alpha classification of clinical AD and NL. This study shows that TNF-alpha and elevated numbers of antibodies against periodontal bacteria associate with AD and contribute to the AD diagnosis.

STUDY OBJECTIVES: Regularity of respiration is characteristic of stable sleep without sleep disordered breathing. Appearance of respiratory irregularity may indicate onset of wakefulness. The present study examines whether one can detect transitions from sleep to wakefulness using only the CPAP flow signal and automate this recognition. DESIGN: Prospective study with blinded analysis SETTING: Sleep disorder center, academic institution. PARTICIPANTS: 74 subjects with obstructive sleep apnealhypopnea syndrome (OSAHS) INTERVENTIONS: n/a. MEASUREMENTS AND RESULTS: 74 CPAP titration polysomnograms in patients with OSAHS were examined. First we visually identified characteristic patterns of ventilatory irregularity on the airflow signal and tested their relation to conventional detection of EEG defined wake or arousal. To automate recognition of sleep-wake transitions we then developed an artificial neural network (ANN) whose inputs were parameters derived exclusively from the airflow signal. This ANN was trained to identify the visually detected ventilatory irregularities. Finally, we prospectively determined the accuracy of the ANN detection of wake or arousal against EEG sleep/wake transitions. A visually identified irregular respiratory pattern (IrREG) was highly predictive of appearance of EEG wakefulness (Positive Predictive Value [PPV] = 0.89 to 0.98 across subjects). Furthermore, we were able to automate identification of this irregularity with an ANN which was highly predictive for wakefulness by EEG (PPV 0.66 to 0.86). CONCLUSIONS: Despite not detecting all wakefulness, the high positive predictive value suggests that analysis of the respiration signal alone may be a useful indicator of CNS state with potential utility in the control of CPAP in OSAHS. The present study demonstrates the feasibility of automating the detection of IrREG

The relationship between chewing gum and short-term learning was investigated as prior studies had reported conflicting results. Incoming 1st-yr dental students were assigned by stratified randomization to either a group who chewed gum during lectures and examinations or a group that did not chew gum. The research subjects listened to a taped lecture on dental anatomy and then completed 2 examinations: a test of specific knowledge which was a multiple-choice test on the dental anatomy lecture material; and a test of generalized knowledge which was a standardized reading comprehension exam. Statistical analysis of the results showed that in a group of graduate students with a history of high academic performance, there was no difference in learning between research subjects who chewed gum compared with those who did not chew gum, as measured by performance on either test

The purpose of this study was to determine the treatment preferences amongst dental faculty and dental students for either retention of teeth by endodontic and restorative treatment or extraction and implant placement. A survey of 134 general dentistry faculty and 253 senior (fourth-year) dental students was conducted in a university college of dentistry. Participants completed a survey consisting of questions for which one of two choices could be selected. For questions describing specific clinical situations, dental faculty and dental students more frequently selected endodontic and restorative treatment over extraction and implant placement. However, dental students selected implants more frequently than dental faculty, and more recent graduates on the dental faculty selected implants more frequently than less recent graduates on the dental faculty. In addition, there was an increase in the selection of implants, for all participant groups, as the prosthetic and endodontic complexities of the clinical situations increased. Participants were more likely to select endodontics rather than implants for medically compromised patients, and an implant was overwhelmingly selected over a fixed bridge for the replacement of a single tooth unit. In conclusion, the findings of this study indicate that retention of teeth is preferred, but there may be an increased preference toward implants in the future.

This paper presents a series of experiments, both in patients and computer models, investigating the transition from acute to chronic hypercapnia in OSA. The data demonstrate that acute hypercapnia during periodic breathing occurs due to either reduction in magnitude of inter-event ventilation and/or reduction in inter-event ventilatory duration relative to duration of the preceding event. The transition between acute hypercapnia during sleep and chronic sustained hypercapnia during wakefulness may be determined by an interaction between respiratory control and renal handling of HCO3-.

Streptococcus mutans is one of several members of the oral indigenous biota linked with severe early childhood caries (S-ECC). Because most humans harbor S. mutans, but not all manifest disease, it has been proposed that the strains of S. mutans associated with S-ECC are genetically distinct from those found in caries-free (CF) children. The objective of this study was to identify common DNA fragments from S. mutans present in S-ECC but not in CF children. Using suppressive subtractive hybridization, we found a number of DNA fragments (biomarkers) present in 88 to 95% of the S-ECC S. mutans strains but not in CF S. mutans strains. We then applied machine learning techniques including support vector machines and neural networks to identify the biomarkers with the most predictive power for disease status, achieving a 92% accurate classification of the strains as either S-ECC or CF associated. The presence of these gene fragments in 90 to 100% of the 26 S-ECC isolates tested suggested their possible functional role in the pathogenesis of S. mutans associated with dental caries.

In previous cross-sectional or case-control studies, clinical periodontal disease has been associated with gestational diabetes mellitus. To test the hypothesis that, in comparison with women who do not develop gestational diabetes mellitus, those who do develop it will have had a greater exposure to clinical and other periodontal parameters, we measured clinical, bacteriological (in plaque and cervico-vaginal samples), immunological, and inflammatory mediator parameters 7 weeks before the diagnosis of gestational diabetes mellitus in 265 predominantly Hispanic (83%) women in New York. Twenty-two cases of gestational diabetes mellitus emerged from the cohort (8.3%). When the cases were compared with healthy control individuals, higher pre-pregnancy body mass index (p=0.004), vaginal levels of Tannerella forsythia (p=0.01), serum C-reactive protein (p=0.01), and prior gestational diabetes mellitus (p=0.006) emerged as risk factors, even though the clinical periodontal disease failed to reach statistical significance (50% in those with gestational diabetes mellitus vs. 37.3% in the healthy group; p=0.38).