Modulation of gamma oscillations by endogenous adenosine through A1 and A2A receptors in the mouse hippocampus.

Adenosine serves as a homeostatic factor, regulating hippocampal activity through A(1) receptor-mediated inhibition. Gamma frequency oscillations, associated with cognitive functions, emerge from increased network activity. Here we test the hypothesis that hippocampal gamma oscillations are modulated by ambient adenosine levels. In mouse hippocampal slices exogenous adenosine suppressed the power of both kainate-induced gamma oscillations and spontaneous gamma oscillations, observed in a subset of slices in normal aCSF. Kainate-induced gamma oscillation power was suppressed by the A(1) receptor agonist PIA and potentiated by the A(1) receptor antagonist 8-CPT to three times matched control values with an EC(50) of 1.1microM. 8-CPT also potentiated spontaneous gamma oscillation power to five times control values. The A(2A) receptor agonist CGS21680 potentiated kainate-induced gamma power to two times control values (EC(50) 0.3nM), but this effect was halved in the presence of 8-CPT. The A(2A) receptor antagonist ZM241385 suppressed kainate-induced gamma power. The non-selective adenosine receptor antagonist caffeine induced gamma oscillations in slices in control aCSF and potentiated both kainate-induced gamma and spontaneous gamma oscillations to three times control values (EC(50) 28muM). Decreasing endogenous adenosine levels with adenosine deaminase increased gamma oscillations. Increasing endogenous adenosine levels with the adenosine kinase inhibitor 5-iodotubericidin suppressed gamma oscillations. Partial hypoxia-induced suppression of gamma oscillations could be prevented by 8-CPT. These observations indicate that gamma oscillation strength is powerfully modulated by ambient levels of adenosine through A(1) receptors, opposed by A(2A) receptors. Increased gamma oscillation strength is likely to contribute to the beneficial cognitive effects of caffeine.

Lip service.

Questionnaires addressing the attitudes of football officials toward National Collegiate Athletic Association (NCAA) mouthguard rules were developed and distributed to officials in the Big East Football Conference, the Southeastern Conference, and to head football coaches at Division 1-A colleges. Response rates, which ranged from 92.45% to 100%, showed that all groups agreed that football officials are less accountable for player compliance than are coaches, trainers and players. However, officials not only observed a lower rate of compliance with NCAA mouthguard regulations than coaches, they also expressed reluctance to enforce NCAA-sanctioned penalties for failure to comply with mouthguard regulations.

Attitudes of college football coaches regarding NCAA mouthguard regulations and player compliance.

OBJECTIVES: The purpose of this study was to assess the attitudes of Division 1-A college head football coaches regarding the NCAA mouthguard regulations, current patterns of use by players, and responsibility for enforcement; and to compare the coaches' responses with those of officials studied previously. METHODS: A 15-item questionnaire was mailed to all 106 Division 1-A football coaches to assess their attitudes. Percent frequency distributions of coaches' responses to each item were computed and compared to the officials' responses. RESULTS: Responses were received from 98 coaches (92.45%). While 87 percent of coaches reported having a team dentist, the majority reported that the team trainer was responsible for selecting the type of mouthguard used. Most coaches (53%) reported that all players wore mouthguards, but that quarterbacks were least compliant. Most coaches reported that mouthguard rules were beneficial in determining player compliance and resulted in more frequent use. Seventy-four percent would warn the player of a violation themselves, yet only 26 percent felt the coach had the greatest influence on players wearing mouthguards. Seventy-six percent felt the current enforcement of the rules is appropriate. Coaches opinions varied from those of officials. CONCLUSIONS: Coaches view themselves, the players, or the trainer as most responsible for players wearing mouthguards, not referees. This finding coincides with the officials' opinion that the coaches should be accountable.

HIV-1 antibody positive hepatitis B surface antigen serum in a dental school patient population.

Testing for human immunodeficiency virus antibody (anti-HIV-1) in patients positive for hepatitis B surface antigen has never been performed in a dental school patient population. In this population there was a 2.8% positive reactivity for HIV-1 antibodies in subjects who were also positive for hepatitis B surface antigen. An enzyme-linked immunoassay with a repeat test and confirmation with a Western blot technique were used.

In vitro torque-deformation characteristics of orthodontic polycarbonate brackets.

The purpose of this study was to investigate the torque-deformation characteristics of the following four types of polycarbonate brackets: (1) pure polycarbonate, PPC (anterior Miura, RMO, Denver, Colo.), (2) ceramic reinforced polycarbonate, CRPC (Silkon bracket, American, Sheboygan, Wis.), (3) metal slot reinforced polycarbonate, MRPC (Plastic bracket, Tella Tech, Miami, Fla.), and (4) metal slot and ceramic reinforced polycarbonate, MCRPC (Spirit, Ormco, Glendora, Calif.). A stainless steel bracket, (Mini Diamond, Ormco, Glendora, Calif.), was used as a control. Ten brackets of each type were tested. Each bracket was bonded to a porcelain tooth and engaged in a torquemeter. The tooth-bracket assembly was made stationary by embedding it in die stone. Torsion was applied to the bracket at 4 degrees per minute and the resultant torque (grams.centimeters) and deformation (degree) were measured. For optimum labiolingual tooth movement for a maxillary incisor at 175 grams . centimeters, the amount of angular deflection necessary for the different polycarbonate brackets was the following: (a) 15 degrees for MRPC, (b) 17 degrees for MRPC, (c) 24 degrees for CRPC, and (d) > 30 degrees for PPC. The amount of deformation at this deflection was the least for MRCP followed by MCRPC, CRCP, and PPC. When compared with the stainless steel bracket, all polycarbonate brackets showed significantly (p < 0.0001) higher deformation and lower torque. Within the polycarbonate group, there was a significant difference (p < 0.0001) between each bracket for both measurements. The MRPC produced the highest torque and lowest deformation values followed by the MCRPC, CRCP, and PPC. It appears that only the metal slot reinforced brackets are clinically capable of torquing teeth sufficiently.

Cancer education curriculum at the Louisiana State University School of Dentistry.

The cancer education curriculum at Louisiana State University School of Dentistry provides students didactic and experiential learning throughout their dental training. Freshman are presented concepts of early detection of cancer in an oral diagnosis course. Later courses in oral diagnosis, medicine, and pathology include diagnostic and treatment decision making and rehabilitative information. Junior students attend a head-and-neck-tumor board composed of dentists and physicians that decides cancer treatment and rehabilitation. Juniors also participate in a biopsy service that includes observing or performing the biopsy, examining the tissue microscopically, and reporting their findings. Additionally, a required, medical and dental, multidisciplinary course in oral oncology provides instruction in diagnosis, treatment, and rehabilitation of cancer patients. Seniors participate in an oral cancer screening service as part of their community dentistry rotation. The postgraduate dental programs and the dental hygiene programs also participate in this curriculum.

Comparative evaluation of college football officials' attitudes toward NCAA mouthguard regulations and player compliance.

A 12-item questionnaire addressing attitudes of football officials toward the 1990 National Collegiate Athletic Association (NCAA) mouthguard regulation was sent to all officials in the Southeastern Conference (N = 62). The response rate was 95% (59). Twenty-seven per cent of officials reported that all players were in compliance; 74% believed the new rule to be at least somewhat beneficial in determining player compliance, and 20% reported that the rule had resulted in more frequent player use. Twenty-two per cent reported they would ignore a mouthguard violation and none had charged a time-out or called a penalty during the 1991 season. Significant differences in the responses of Big East officials surveyed in a previous study were noted by the authors, when compared to the SEC, but both groups of officials strongly supported the idea that wearing mouthguards should be the responsibility of coaches rather than officials.

Attitudes of college football officials regarding NCAA mouthguard regulations and player compliance.

The National Collegiate Athletic Association (NCAA) mandates the use of brightly colored, intraoral mouthguards by football players to reduce the frequency and severity of craniofacial and intraoral morbidity and mortality, and to enhance the ability of officials to observe player compliance. The purpose of this 12-question mail survey was to determine the attitudes of on-field game officials regarding current NCAA mouthguard regulations and patterns of utilization by college football players. The sample consisted of all 50 Big East Football Conference officials; a response rate of 100 percent was achieved. Only 42 percent of the officials reported observing all players in compliance, and quarterbacks were identified by others as the least compliant group (52%). The majority (88%) indicated that the 1990 rule for brightly colored mouthguards had been beneficial to them in determining player compliance, and 52 percent reported that this rule had resulted in more frequent use by these athletes. Nearly all officials (96%) indicated that they would issue a warning for noncompliance to the player or coach, rather than charging a timeout for a violation as prescribed by NCAA regulations. The majority (70%) believe current enforcement is appropriate, but expressed the opinion that coaches should be held more accountable for player compliance.

Public knowledge about AIDS: a survey of dental school patients. Part I.

Surveys have demonstrated that the general public has many misconceptions about acquired immunodeficiency syndrome (AIDS) and human immunodeficiency virus (HIV) infection. Education has been the mainstay of the public health effort to combat the spread of HIV and AIDS. Some studies have shown an increase in the public's understanding of this disease. A survey of dental patients at a dental school clinic revealed that although misconceptions continue to exist, particularly with regard to AIDS and the dentist, this population had higher levels of knowledge about AIDS than did those in earlier studies.

Public knowledge about AIDS: a survey of dental school patients. Part II.

Responses to a questionnaire on acquired immunodeficiency syndrome (AIDS) returned by patients of the Louisiana State University School of Dentistry were compared with responses to an AIDS questionnaire administered by the National Center for Health Statistics (NCHS). Although the questionnaire in this study was not patterned after that used by NCHS, some of the questions were either similar or directly opposite in content. Response patterns were compared and contrasted. In addition, those response patterns in Part I which are significantly different on the basis of demographic characteristics were compared with their counterparts in the NCHS survey.

Subgingival bacteria associated with hydroxylapatite-coated dental implants: morphotypes and trypsin-like enzyme activity.

This study investigated the colonization of teeth and hydroxylapatite-coated dental implants by different groups of oral bacteria. Periodontal and gingival health were assessed and subgingival plaque samples were taken. Bacterial morphotypes in subgingival plaque samples were enumerated and expressed as percent of bacteria counted, and presence of trypsin-like enzymes was detected by hydrolysis of benzoyl-arginine naphthylamide (BANA). For both pooled and separate implant and teeth data, positive correlations were found between pocket depth and both BANA hydrolysis and percent spirochetes, and a negative correlation was found between pocket depth and percent cocci. With one exception, analysis of variance revealed no significant differences between implants and teeth for presence of bacterial morphotypes when considering both periodontal and gingival health.

Dental implants: a survey of patients' attitudes.

This study measured the psychologic attitudes of patients to implant prostheses and compared their status before and after therapy. Questionnaires were mailed to 95 patients with implants placed and restored at a university dental school. The implants had been in position for an average of 2.2 years. The patients had previously worn removable complete or partial dentures. Different questions addressed eating, speaking, relationships, employment, social life, esthetics, maintenance, and overall dental health. Sixty-one questionnaires were returned (64%). Satisfaction with the implant prosthesis was significantly greater than for the denture (p less than 0.0001). Responses to individual questions indicated that confidence was improved (88%), implants were worth the trouble (97%), the procedure would be worth repeating (89%), and overall dental health was improved (98%). This survey suggests that patients' attitudes toward their dental health improve significantly after treatment with implant prostheses.

Dental students' class attitudes: a four year study.

Students in a professional school develop class attitudes that may differ from their individual attitudes and from the educational ideals of faculty. They may be affected positively through the cooperation engendered by the shared attitudes. However, the shared attitudes may be detrimental to student learning. Peer pressure may encourage average performance and unacceptable methods of acquiring information. A survey of class attitudes was designed and administered to the Class of 1988 at Louisiana State University School of Dentistry during each of their four years of training. Percentages of agreement were calculated for each item and chi square analysis was used to compare differences over the four years. Fifty-six students completed the initial administration and 30 of the 50 seniors completed the last administration. The results suggest that although many class attitudes remained stable over the four years, there were some significant changes. The students indicated that as a class they became more likely to take short cuts, to cheat on exams, and to get by with as little effort as possible. As seniors the students showed more positive class attitudes than they had as juniors, but there was a steady deterioration of class attitudes toward the school and faculty over the four years.