Transcriptional analysis of the mouse beta-casein gene.

These studies were designed to further elucidate the relative contributions of transcriptional and posttranscriptional mechanisms involved in beta-casein gene regulation in the mammary epithelial cell line designated COMMA-D and a clonal subline desginated HC-11. Primary transcripts were mapped under various hormonal and substratum conditions using the technique of nuclear run-on transcription and single stranded sense and antisense probes spanning the beta-casein gene. In the presence of insulin alone very little sense transcription is detectable, but antisense transcription is observed, which originates at least 150 basepairs upstream of the normal start site of transcription and is present regardless of hormonal, cell substratum, cell type, or gene activity. Antisense transcription is also detectable in the 3' end of the gene. Insulin, glucocorticoids, and PRL are all necessary for a maximal increase in transcription. A 2- to 4-fold increase in transcriptional activity is observed in the presence of insulin and PRL compared to insulin alone, and this is accompanied by a 125-fold increase in the level of beta-casein mRNA. All three hormones act synergistically to induce a 10-fold increase in transcriptional activity, but the transcriptional increase across the gene is not equimolar. The 5' half of the gene is transcribed at a level that is 2- to 10-fold lower than that of the 3' half of the gene. These studies reveal a significant transcriptional component to beta-casein gene regulation which was not heretofore detected using double stranded cDNA probes representative of only the 3' half of the gene.

Sterilization of dental instruments and devices: an update.

Dental sterilization techniques have become a focus of attention as a result of disclosure of occupational HIV transmission from an infected dentist to a cluster of patients. Although there has never been a confirmed report of a patient acquiring an infectious blood-borne disease from a dental instrument or device, recommendations for universal sterilization of dental handpieces and other devices have recently been implemented. Because of the higher rate of hepatitis B virus transmissability in the dental health care environment, an upgrade in sterilization protocols may be warranted. Stringent sterilization standards are especially necessary in higher-risk institutional dental care settings. However, a high rate of dental sterilization errors has been reported and traced to operator error. Recent institutional dental sterilization policy changes have been developed to reduce the chance of sterilization error, further diminishing the risk of cross contamination.

Role of cytology in the intraoperative diagnosis of central demyelinating disease.

OBJECTIVE: To determine the usefulness of cytology in the intraoperative diagnosis of central demyelinating disorders. STUDY DESIGN: Smears of three multiple sclerosis (MS) plaques and two progressive multifocal leukoencephalopathy (PML) lesions prepared intraoperatively were examined and compared. The cytologic features were contrasted with those of infiltrating astrocytomas. RESULTS: The preparations of demyelinating lesions revealed normal or reactive astrocytes and large numbers of foamy macrophages, the key diagnostic finding. The preparations of the lesions of PML contained virally infected oligodendrocytes. The specific cell types were identified easily because cytoplasmic margins could be distinguished. CONCLUSION: Cytologic preparations of lesions of PML and MS permitted rapid identification of the diagnostic features and distinguished them from infiltrating astrocytomas, the most important lesion in the differential diagnosis. The findings demonstrated the utility of cytology in the diagnosis of central demyelinating diseases.

Dental health personnel planning: a review of the literature.

Dental personnel planning is important in formulating policy in dental education, dental public health programs, and dental care delivery systems. The purpose of this literature review is to illustrate the use of dentist-to-population ratios, need-based models, and demand-based models in the determination of appropriate supply of dental personnel. A historical perspective is provided that demonstrates how political manipulation and subjectivity have characterized the use of these models by organized dentistry, the federal government, and others. The lack of pertinent data and the inability to predict economic, social, political, and epidemiologic trends weaken the applicability of each model in determining future personnel levels. Considering the long-term consequences of the use of each model in personnel planning, caution is urged in using any of the presently available models.

Maryland adults' knowledge of oral cancer and having oral cancer examinations.

OBJECTIVES: This study sought to determine (1) knowledge of risk factors for oral cancer, (2) knowledge of signs and symptoms of oral cancers, and (3) factors associated with having had an oral cancer examination among 916 Maryland adults 18 years of age and older. METHODS: A statewide, random-digit dial, computer-assisted telephone survey was conducted. The pretested instrument consisted of 32 questions that required 12 minutes to complete. RESULTS: Overall, level of knowledge about risk factors for and signs and symptoms of oral cancers was low; misinformation was high. Although 85 percent reported hearing about oral or mouth cancer, only 28 percent of the respondents reported having had an oral cancer examination. Of these, 20 percent had the exam during the past year--the recommended frequency for persons 40 years of age or older. In logistic regression analysis, adults more likely to have had an oral cancer examination included those who thought personal behavior causes more cancer than environmental factors; had more knowledge about risk factors for oral cancer; and were 40-64 years of age, white, and better educated than their counterparts (P < .05). The primary reasons for not having an exam were "no reason/didn't know I should" and "doctor/dentist didn't recommend." CONCLUSIONS: These results demonstrate a need for interventions designed to increase knowledge levels of risk factors for, signs, and symptoms of oral cancers and the need for oral cancer examinations; and to increase oral cancer examinations.

The need for health promotion in oral cancer prevention and early detection.

OBJECTIVES: This review paper provides a rationale for using health promotion to help reduce morbidity and mortality due to oral cancers by identifying barriers to prevention and early detection of these cancers and discussing strategies for change. METHODS: A literature review of the following areas was conducted: epidemiology of and risk factors for oral cancers; knowledge, opinions, and practices of health care providers and the public regarding prevention, early detection, and control of oral cancers; and policies and regulations that either enhance or act as barriers to the prevention and early detection of oral cancers. RESULTS: Overall, the public is ill-informed about risk factors for and signs and symptoms of oral cancers and relatively few US adults have had an oral cancer examination. Further, health care providers are remiss in providing oral cancer examinations and detecting early oral cancers. CONCLUSIONS: To achieve the 13 oral cancer objectives contained in "Healthy People 2000," health care providers and the public must know the risk factors for these cancers as well as their signs and symptoms. Further, health care providers need to provide oral cancer examinations routinely and competently. Equally important, the public needs to know that an examination for oral cancer is available and that they can request one routinely. Thus, a vigorous agenda that includes education, policy, and research initiatives is needed to enhance oral cancer prevention and early detection.

Assessing physicians' and dentists' oral cancer knowledge, opinions and practices.

Oral cancer is responsible for more than 8,000 deaths each year. This mortality may be attributed to lack of effective oral examinations by dental and medical primary care clinicians. This pilot project assessed the knowledge, opinions and practices of a group of Maryland physicians and dentists in oral cancer prevention, diagnosis and detection. Dentists performed more oral cancer examinations, although physicians saw more high-risk patients.

Managing patients with Alzheimer's: the primary care role of dentists.

The primary care role of a dentist in the comprehensive care and management of a patient with Alzheimer's disease and the caregiver is described. As part of a geriatric assessment team, the dentist can contribute to a strategy addressing these patients' complex needs.

Oral pharyngeal cancer prevention and early detection. Dentists' opinions and practices.

BACKGROUND: The five-year survival rate for patients in the United States diagnosed with oral pharyngeal cancer is 52 percent, which suggests that these cancers are diagnosed at late stages. The authors conducted this study to determine U.S. dentists' opinions and practices regarding oral cancer prevention and early detection. METHODS: The authors mailed a pretested survey to 7,000 randomly selected general practitioners. A total of 3,200 dentists provided information on how they conduct oral cancer examinations, their use of health history questions to assess patients' oral cancer risks and their oral cancer training and practices. The authors carried out analyses using unweighted data; both bivariate and logistic analytical techniques at a P < or = .01 level of significance were used. RESULTS: On average, dentists assessed about five of the eight health history items on the survey. Eighty-six percent indicated that they did not conduct oral cancer examinations on edentulous patients 18 years of age or older; 81 percent, however, reported that they conducted oral cancer examinations for 100 percent of their patients 40 years of age or older on their initial appointment. CONCLUSIONS: The reported practices of these dentists regarding oral cancer, in conjunction with their opinions about key aspects of these practices and their training, point to a need for systematic educational updates in oral cancer prevention and early detection. CLINICAL IMPLICATIONS: Dentists need to determine their patients' risks for oral cancers and provide routine and comprehensive oral cancer examinations.

Survey of U.S. dentists' knowledge and opinions about oral pharyngeal cancer.

BACKGROUND: Oral pharyngeal cancer constitutes the most life-threatening of all dental and craniofacial conditions. The U.S. five-year survival rate of 52 percent for these cancers is one of the lowest and has not changed in decades. METHODS: The authors mailed a pretested survey to 7,000 randomly selected general dentists. They obtained information on 3,200 dentists' levels of knowledge about oral pharyngeal cancer risks and diagnostic procedures for providing an oral cancer examination, as well as about related opinions and interest in continuing education, or CE, courses on the topic. The authors carried out analyses using unweighted data; they used both bivariate and logistic analytical techniques and evaluated at a significance level of P < or = .01. RESULTS: Based on responses to 14 questions, the average knowledge of oral cancer risks score was 8.4. About one-half of dentists surveyed knew the two most common sites of intraoral cancer and that most oral cancers are diagnosed at a late stage. CONCLUSIONS: The reported knowledge of these dentists regarding oral cancer suggests that they are not as knowledgeable as they could be about cancer prevention and early detection and that they recognize these deficiencies. Most of the dentists were interested in oral cancer CE. CLINICAL IMPLICATIONS: Dentists need to know where in the mouth to look and what types of lesions to look for to provide a comprehensive oral cancer examination.

Knowledge, opinions and practices of general dentists regarding oral cancer: a pilot survey.

The authors mailed a pilot survey to 500 randomly selected general dentists. Although most dentists reported their knowledge of oral cancer to be current, their actual knowledge of oral cancer risk factors and signs and symptoms was inconsistent. Conflicting data were also found between their level of knowledge and their provision of oral cancer examinations. Most respondents agreed that patients should undergo an oral cancer examination annually, yet many do not provide this service.

Assessment of alcohol and tobacco use in dental schools' health history forms.

Health history forms are an integral component of students' clinical and didactic training in physical assessment and often serve as a model for students to use in their future practices. This study examined how alcohol and tobacco use are assessed in patient health history forms used in the dental schools of the United States and Canada (n = 63). Deans of schools were requested to send a copy of their health history and other supplemental forms used for patient care. The response rate was 98 percent. Almost 25 percent of the schools' forms did not address either alcohol or tobacco use; 37 percent failed to address one or both risk behaviors; 25 percent did not request tobacco information; and 36 percent did not address alcohol use. Major inconsistencies regarding the inclusion, content, and quantity of alcohol and tobacco questions were noted. Consensus among dental schools as to which questions to include in their health forms was not apparent.

A review of chlorhexidine and its use in special populations.

The purpose of this paper is to review the mechanism of the action, safety, and side-effects of chlorhexidine, and to provide guidelines for its use in special populations. Chlorhexidine has been used orally since 1959, primarily for the control of dental plaque. Chlorhexidine is a safe material, with low toxicity potential when used correctly. The most conspicuous side-effects are the development of yellow-brown stains on the teeth, tongue, and at the margins of anterior restorations, and an alteration in taste sensation. The use of chlorhexidine is indicated in developmentally disabled, medically compromised patients, and in dependent elderly populations, since these groups are often physically unable to remove plaque by mechanical means. Clinicians should not prescribe chlorhexidine indiscriminately for all patients, however, until analyzing its efficacy, safety, and side-effects.

Knowledge, opinions, and practices related to oral cancer: results of three elderly racial groups.

A study of 204 inner-city, senior center participants (ages ranged from 41-96 years) was conducted to assess their knowledge, opinions, and practices related to oral cancer. Participants were either White, African-American, or of Korean descent. The interview/questionnaire revealed this cohort to lack correct knowledge of the signs, symptoms, and risk factors of oral cancer, and to have had risk behaviors associated with oral cancer. Given that oral cancer is most frequently diagnosed in those aged 65 years and older, and that this cohort tends not to obtain routine preventive oral health care, it is imperative that these seniors be educated about the risks associated with oral cancer and their need for routine oral examinations.

Oral health knowledge, practices, and status among outpatient veterans at the VA Maryland Health Care System.

Poor oral health can have a significant impact on overall health and quality of life. Yet few studies have established the oral health needs of outpatient veterans. The purpose of this study was to assess the oral health knowledge and practices, the dental status, and the periodontal treatment needs of outpatient veterans seeking primary care services at a statewide healthcare system. Veterans were interviewed and received an oral examination by a trained examiner using NIDCR criteria for dental caries detection and the Community Periodontal Index of Treatment Needs (CPITN). The mean age of the study participants' (n = 135) was 57.7 (SD = 14.1) years. Ninety-five percent of the sample was male and 44% African-American. Untreated coronal and root caries was present in 57% and 36% of veterans, respectively. Sixty-nine participants received the periodontal examination, with 29% of them in Category III. An interpretation of these findings shows a high need for preventive and restorative oral health care among outpatient veterans receiving primary services in an integrated and comprehensive VA health care system.

Oral cancer mortality in Maryland.

Oral cancer mortality is one of the most preventable types of cancer deaths when the lesion is detected early. The survival rate is quite low, however, when oral cancer is diagnosed at an advanced stage. While the Maryland oral cancer incidence rate is lower than the US average, the state ranks fourth in the country for overall age-adjusted oral cancer mortality; Maryland's African-American population has the highest oral cavity and pharyngeal mortality rate. Delayed diagnosis may explain this occurrence since groups at high risk for developing oral cancer, such as the elderly and minority groups, do not have ready access to the Maryland oral health care system. As the elderly annually use physicians' services almost twice as much as they use dentists' services, physicians are encouraged to routinely complete an oral cavity and pharyngeal examination. Inclusion of oral health services into a Maryland health system reform benefits package would also improve routine screening frequency for oral cancer.

The tyrosine-225 to phenylalanine mutation of Escherichia coli aspartate aminotransferase results in an alkaline transition in the spectrophotometric and kinetic pKa values and reduced values of both kcat and Km.

Tyrosine-225 is hydrogen-bonded to the 3'-hydroxyl group of pyridoxal 5'-phosphate in the active site of aspartate aminotransferase. Replacement of this residue with phenylalanine (Y225F) results in a shift in the acidic limb of the pKa of the kcat/KAsp vs pH profile from 7.1 (wild-type) to 8.4 (mutant). The change in the kinetic pKa is mirrored by a similar shift in the spectrophotometrically determined pKa of the protonated internal aldimine. Thus, a major role of tyrosine-225 is to provide a hydrogen bond that stabilizes the reactive unprotonated form of the internal aldimine in the neutral pH range. The Km value for L-aspartate and the dissociation constant for alpha-methyl-DL-aspartate are respectively 20- and 37-fold lower in the mutant than in the wild-type enzyme, while the dissociation constant for maleate is much less perturbed. These results are interpreted in terms of competition between the Tyr225 hydroxyl group and the substrate or quasi-substrate amino group for the coenzyme. The value of kcat in Y225F is 450-fold less than the corresponding rate constant in wild type. The increased affinity of the mutant enzyme for substrates, combined with the lack of discrimination against deuterium in the C alpha position of L-aspartate in Y225F-catalyzed transamination [Kirsch, J. F., Toney, M. D., & Goldberg, J. M. (1990) in Protein and Pharmaceutical Engineering (Craik, C. S., Fletterick, R., Matthews, C. R., & Wells, J., Eds.) pp 105-118, Wiley-Liss, New York], suggests that the rate-determining step in the mutant is hydrolysis of the ketimine intermediate rather than C alpha-H abstraction which is partially rate-determining in wild type.

An assessment of oral cancer prevention curricula in U.S. medical schools.

BACKGROUND: Oral cancer is readily detectable through routine examination, but five-year survival rates remain low. Physicians bear the same responsibilities as dentists in the early detection of oral cancers, because high-risk patients utilize medical services more often than dental services. METHODS: Because physicians' practices are largely influenced by their training, this study assessed the level of oral cancer education provided to undergraduate U.S. medical students. Health history and physical diagnosis course curricula were assessed for relevant content. RESULTS: The response rate from the U.S. medical schools was 63.2%. When compared with the "gold standard," the average score was 43% of the optimum. Seven percent of the schools did not require inspection of the mouth, 29% required inspection of all oral structures, and intraoral palpation was advocated by 43% of the schools. Although most schools included questions about alcohol and tobacco use, only 13% asked about sunlight exposure. CONCLUSION: Preliminary oral cancer training in medical schools regarding physical assessment and elicitation of signs, symptoms, and high-risk behaviors lacks both adequacy and comprehensiveness.

Maryland veterans' knowledge of risk factors for and signs of oral cancers and their use of dental services.

OBJECTIVES: The purpose of this study was to evaluate outpatient veteran'í knowledge about risk factors for and signs of oral cancers, and their utilization of dental services. DESIGN: Patients receiving primary health care services were surveyed during August 1997. SETTING: Primary health care services at three medical centres within the VA Maryland Health Care System (VAMHCS). SUBJECTS: A total of 135 outpatient veterans were interviewed. INTERVENTION: Questionnaire administered by trained interviewers. MAIN OUTCOME MEASURES: Fifteen percent of the sample were eligible for dental care at the VA, while over 40% of those veterans participating in the study were unaware of their VA eligibility for dental services. Fifty six percent of the total sample received dental services from a private dentist, while 13% reported they had no provider of dental care. Of those not eligible for dental care at the VA (n = 115), the majority (67%) received dental care from a private dentist. Current use of tobacco and alcohol was reported by 27% of the sample. Nonsmokers were more likely to visit the dentist in the previous year than smokers (OR = 2.39, 95% C.I. 1.11,5.12). Although 84% correctly identified tobacco use as a risk factor, only 39% correctly identified regular alcohol use as a risk factor. CONCLUSIONS: Veterans at higher risk for oral cancers were less likely to have visited the dentist in the previous year, and, overall, were ill informed and misinformed about these cancers.