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Biomedical subjects

D M Davidson

Publications and source records attributed to D M Davidson.

At least 19 recordsLinked to original sources
PubMed2001

Perinuclear antineutrophilic cytoplasmic antibody-positive cutaneous polyarteritis nodosa associated with minocycline therapy for acne vulgaris.

Minocycline is an oral antibiotic widely used for the long-term treatment of acne vulgaris. Unusual side effects of this medication include two overlapping autoimmune syndromes: drug-induced lupus and autoimmune hepatitis. In addition, in a few patients livedo reticularis or subcutaneous nodules have developed in association with arthritis and serum perinuclear antineutrophil cytoplasmic antibodies (P-ANCA) during long-term minocycline therapy. We report the cases of two young women receiving long-term minocycline therapy (>3 years) in whom P-ANCA-positive cutaneous polyarteritis nodosa developed. Both patients presented with a violaceous reticulated pattern on the lower extremities. Histologic examination of biopsy specimens from a reticulated area and a subcutaneous nodule showed necrotizing vasculitis of medium-sized arteries in the deep dermis, consistent with the diagnosis of polyarteritis nodosa. The cutaneous lesions rapidly resolved on discontinuation of minocycline and initiation of prednisone therapy. A high index of suspicion and testing for antineutrophil cytoplasmic antibody in addition to the standard antinuclear antibody panel can facilitate diagnosis of minocycline-related autoimmune disorders.

Acne Vulgaris↗
PubMed2000

NF-kappa B inhibition causes spontaneous apoptosis in Epstein-Barr virus-transformed lymphoblastoid cells.

Epstein-Barr virus (EBV) transforms B lymphocytes into lymphoblastoid cell lines usurping the Notch and tumor necrosis factor receptor pathways to effect transcription including NF-kappaB activation. To determine whether NF-kappaB activity is essential in the growth and survival of EBV-transformed lymphoblastoid cell lines, a nondegradable IkappaBalpha mutant was expressed under tetracycline regulation. Despite continued Bcl-2 and Bcl-x/L expression, NF-kappaB inhibition induced apoptosis as evidenced by poly(ADP-ribose) polymerase cleavage, nuclear condensation and fragmentation, and hypodiploid DNA content. Both caspase 3 and 8 activation and loss of mitochondrial membrane potential were observed in apoptotic cells. However, caspase inhibition failed to block apoptosis. These experiments indicate that NF-kappaB inhibitors may be useful in the therapy of EBV-induced cellular proliferation.

Amino Acid Chloromethyl Ketones↗
PubMed1998

Epstein-Barr virus-transforming protein latent infection membrane protein 1 activates transcription factor NF-kappaB through a pathway that includes the NF-kappaB-inducing kinase and the IkappaB kinases IKKalpha and IKKbeta.

The Epstein-Barr virus oncoprotein latent infection membrane protein 1 (LMP1) is a constitutively aggregated pseudo-tumor necrosis factor receptor (TNFR) that activates transcription factor NF-kappaB through two sites in its C-terminal cytoplasmic domain. One site is similar to activated TNFRII in associating with TNFR-associated factors TRAF1 and TRAF2, and the second site is similar to TNFRI in associating with the TNFRI death domain interacting protein TRADD. TNFRI has been recently shown to activate NF-kappaB through association with TRADD, RIP, and TRAF2; activation of the NF-kappaB-inducing kinase (NIK); activation of the IkappaB alpha kinases (IKKalpha and IKKbeta); and phosphorylation of IkappaB alpha. IkappaB alpha phosphorylation on Ser-32 and Ser-36 is followed by its degradation and NF-kappaB activation. In this report, we show that NF-kappaB activation by LMP1 or by each of its effector sites is mediated by a pathway that includes NIK, IKKalpha, and IKKbeta. Dominant negative mutants of NIK, IKKalpha, or IKKbeta substantially inhibited NF-kappaB activation by LMP1 or by each of its effector sites.

Animals↗
PubMed1997

How intermediate sanctions change the dynamics of healthcare transactions.

The Taxpayer Bill of Rights 2 contains significant reforms relating to tax-exempt organizations, most notably the establishment of intermediate tax sanctions. These changes, which clarify tax rules applicable to tax-exempt HMOs, hospitals, and integrated delivery systems, are of particular interest to entities that are or will be involved in joint ventures or other business alliances with physicians and other for-profit partners, the officers and directors of such entities, and the physicians and for-profit partners in the ventures. For the first time, the legislation imposes monetary penalties on those engaging in transactions with tax-exempt healthcare providers if impermissible private inurement is involved.

Conflict of Interest↗
PubMed1995

Addressing integrated systems' tax-exemption problems.

Integrating for-profit providers with charitable providers raises many questions about tax exemption. The traditional criteria for determining tax-exempt status that apply to hospitals do not necessarily apply to integrated delivery systems because of their hybrid nature. The appropriate Internal Revenue Service (IRS) rulings and issues must be understood and adhered to before an integration can be structured in the most tax-efficient way. Reasonable as such a course of action seems, it is somewhat difficult because both the integrated delivery system concept and the IRS rulings that apply are evolving. In a time of flux, this article serves as a timely if temporary guide.

Community-Institutional Relations↗
PubMed1994

Observations on 200 surgical cases of tarsal tunnel syndrome.

Surgical intervention for tarsal tunnel syndrome has been reported since the mid-1960s. In 1975, the authors published their experiences using nerve conduction studies for the diagnosis and follow-up of tarsal tunnel syndrome. Since that time, the authors have operated on approximately 200 cases when conservative care failed to alleviate symptoms to a sufficient degree. In this article, a brief overview of our findings and follow-up is provided.

Follow-Up Studies↗
PubMed1994

Atrophia maculosa varioliformis cutis. Report of two cases and review of the literature.

Atrophia maculosa varioliformis cutis was initially described in 1918 as an entity in which both linear and punctate scars appeared spontaneously on normal facial skin. To the best of our knowledge, only five additional cases have been described. We describe two patients, 14 and 20 years of age, whose histories and clinical lesions fit the description of atrophia maculosa varioliformis cutis. The histologic findings are also described, and the literature to date is reviewed.

Adolescent↗
PubMed1992

Cardiovascular disease prevention: knowledge and attitudes of graduate nursing students.

Graduate nursing students were surveyed to determine the knowledge and attitudes of cardiovascular disease prevention. Questionnaires were self-administered to first-year graduate nursing students (n = 50) in a school of nursing prior to and following a physiology course with cardiovascular disease prevention content. In general, the results demonstrated that the respondents were least knowledgeable regarding the prevalence of smoking, the gender differences in high-density lipoprotein (HDL)-cholesterol levels, the influence of body weight on lipids and the recommended percentages of calories from dietary fat. A significant improvement in knowledge was noted after the course. Positive attitudes regarding the importance of cardiovascular disease prevention and the partnership between patients and clinicians necessary to manage risk were identified. These attitudes did not change significantly following the course. These results indicate that graduate education which emphasizes cardiovascular disease prevention increases knowledge. Coupled with positive attitudes and healthy personal lifestyle behaviours, knowledge of cardiovascular disease prevention may enhance the ability of nurses to integrate preventive standards into clinical practice and ultimately decrease the risk of cardiovascular disease.

Adult↗
PubMed1992

Television viewing and pediatric hypercholesterolemia.

Cholesterol screening for children is recommended currently only for those with a family history of premature coronary heart disease or hyperlipidemia. The authors report on a pediatric-office-based cholesterol screening program where the predictive values of family history indicators were evaluated along with reported television viewing, physical activity, and dietary habits in 1081 children (aged 2 to 20 years, mean 7.4 +/- 3.6 [SD] years). Eight percent of these children had a total cholesterol value of 200 mg/dL or higher; 53% of such children reported watching 2 or more hours of television daily compared with 34% of children with lower cholesterol levels. Multivariate analyses revealed that excessive television viewing was the strongest predictor for a child to have a cholesterol value of 200 mg/dL or higher, with relative risks of 2.2 for 2 to 4 hours of television viewing per day (P less than .01) and 4.8 for children watching more than 4 hours/day, when compared to those watching less than 2 hours/day (P less than .01). In contrast, a positive family history of a high cholesterol level was only modestly associated with an increased probability of having a high cholesterol level (relative risk = 1.6, P less than .05), and a history of premature myocardial infarction in a parent or grandparent was not associated with a child's cholesterol level. Excessive television viewing was found to be associated with certain dietary and physical activity habits and may prove to be a useful, global marker for several life-style factors predisposing children to hypercholesterolemia.

Adolescent↗
PubMed1991

Family history fails to detect the majority of children with high capillary blood total cholesterol.

To examine the predictive value of family history in detecting children with high blood cholesterol, finger-stick screening was done in 1,118 children ages 9-10 whose parents provided parental and grandparental history of cardiovascular disease events and risk factors. Mean blood total cholesterol was 167.7 mg/dl with no significant gender or ethnic differences. Of 157 children with blood cholesterol 200 mg/dl or greater, only 61 (38.9%) had a family history of early myocardial infarction or hyperlipidemia; however, the prevalence of a positive family history varied from 2.8% in Vietnamese-Americans to 38.5% in Spanish-surnamed students to 52.6% in all other children. Adherence to current policies recommending screening only children with a positive family history will result in failing to detect a majority of children whose blood cholesterol levels exceed desirable levels for adults, particularly those from ethnic families recently arrived in the U.S.

Analysis of Variance↗
PubMed1990

Risk factors for cardiovascular disease in U.S. medical students: the Preventive Cardiology Academic Award Collaborative Data Project.

Risk factors for cardiovascular disease are commonly obtained in freshman medical students for the purpose of increasing interest and awareness in preventive cardiology. What would be a normal range of values for this select group? This paper describes the major cardiovascular risk factors for 3,811 male and female freshman medical students from eight U.S. medical schools that were obtained in a standardized fashion as part of the Preventive Cardiology Academic Award (PCAA) programs at these institutions. The distributions of height, weight, Quetelet index, systolic and diastolic blood pressures, total cholesterol, triglycerides, high-density lipoprotein cholesterol, and calculated low-density lipoprotein cholesterol are presented for male and female medical students stratified by race into white, black, Asian, and Hispanic groups. The sex and race distributions of cardiovascular risk factors such as previously diagnosed hypertension, diabetes mellitus, smoking, lack of regular exercise (three times a week or more), oral contraceptive use in women, and family history of coronary heart disease are presented. The cardiovascular risk of freshman medical students is compared to other epidemiologic studies of young adults. The use and limitations of these race- and sex-specific data on cardiovascular risk, including physiologic measurements, are discussed in the context of educational programs for medical students and house staff in preventive cardiology.

Adult↗
PubMed1990

Teaching preventive cardiology through community programs.

Entering medical students currently report positive attitudes toward the concept of preventive cardiology but express a lack of confidence in the physician's ability to change unhealthful habits of their patients. One approach to this problem has been the involvement of medical students and house staff physicians in cardiovascular health programs offered in the community. With the goal of enhancing the knowledge, attitudes, and skills of the trainees, these programs have been carried out in educational institutions at all levels, in churches, and at work sites, shopping malls, and health fairs. Informal assessment of these programs suggests that medical trainees develop an increased sense of confidence in their ability to influence positively the health habits of children and adults.

Attitude of Health Personnel↗
PubMed1989

Cardiovascular effects of alcohol.

The effects of alcohol on the heart include modification of the risk of coronary artery disease, the development of alcoholic cardiomyopathy, exacerbation of conduction disorders, atrial and ventricular dysrhythmias, and an increased risk of hypertension, hemorrhagic stroke, infectious endocarditis, and fetal heart abnormalities.

Alcohol Drinking↗
PubMed1988

Attitudes toward prevention of cardiovascular diseases among first-year students at eight American medical schools, 1983-1985.

First-year medical students at eight U.S. medical schools were surveyed by written questionnaire in 1983-1985 to determine their attitudes toward cardiovascular diseases prevention at medical school entry. An overall response rate of 92% was achieved (2,654 questionnaires), and 97% of responders provided complete and analyzable survey data. Response rates at five of eight medical schools were 98-100%, and one school each had rates of 67, 84, or 90%. Differences in mean attitude responses from school to school were small, as were differences between men and women or between blacks and whites. This survey found that entering medical students have generally positive attitudes toward the effectiveness of preventive cardiology practice as well as toward the importance of research efforts in cardiovascular disease prevention. Students frequently indicated, however, that it is "extremely difficult" to change patients' unhealthful habits and that "physician encouragement" may not be sufficient to help patients achieve more healthful behaviors. These findings could be helpful in directing educational efforts for medical students. The data suggest that major emphasis should be placed on conveying facts regarding the physicians' efficacy in clinical preventive cardiology and on teaching the skills of preventive cardiology practice. Less emphasis appears to be necessary on encouraging positive attitudes about the importance of prevention since current students' attitudes appear to be already positive in this dimension.

Attitude of Health Personnel↗
PubMed1988

Oat bran as a cholesterol-reducing dietary adjunct in a young, healthy population.

In a study to examine the effects of dietary oat bran on serum lipids, subjects who ate two oat bran muffins a day for 28 days showed a 5.3% reduction in serum total cholesterol and an 8.7% reduction in low-density-lipoprotein-cholesterol levels, while no changes were noted in subjects consuming wheat or mixed wheat and oat bran muffins. Similarly, those who ingested oat bran muffins showed an 8.3% reduction in serum triglyceride values as contrasted with an overall increase of 6.4% in the other groups combined. These findings suggest that oat bran taken daily can significantly lower serum cholesterol and triglyceride levels in a young, healthy population.

Adult↗
PubMed1987

Relationship between age, body size, gender, and blood pressure and Doppler flow measurements in the aorta and pulmonary artery.

Previous studies have demonstrated a relationship between both age and body surface area (BSA) and M-mode echocardiographic measurements of left ventricular, left atrial, and aortic root dimensions and left ventricular wall thickness. We evaluated the relationships between age, BSA, gender and blood pressure, and Doppler aortic and pulmonary artery (PA) flow velocity measurements in 97 adults, aged 21 to 78 years, without clinical evidence of cardiac disease. No significant relationship was found between gender or blood pressure and aortic or PA flow velocity measurements. Aortic peak flow velocity, flow velocity integral, and average acceleration decreased with increasing age (all p less than 0.001), whereas ejection time (corrected for heart rate) increased, and acceleration time did not change. In contrast, there was no relationship between age and Doppler PA flow velocity measurements. Although there was no relationship between BSA and Doppler aortic flow measurements, PA peak flow velocity and average acceleration increased, while acceleration time decreased with increasing BSA (all p less than 0.02). Decreases in aortic peak flow velocity and flow velocity integral may be partly related to known increases in aortic root diameter with aging. The relationship between PA flow velocity measurements and BSA is not readily explained.

Adult↗
PubMed1986

Defective gamma-interferon production in peripheral blood leukocytes of patients with acute tuberculosis.

Production of interferon (IFN)-gamma by peripheral blood leukocytes (PBL) was examined in cultures of unseparated fresh whole blood exposed to phytohemagglutinin (PHA), concanavalin A (Con A), or pokeweed mitogen (PWM). The yield of IFN-gamma was measured by a newly developed immunoradiometric assay. Nine of 14 patients with acute pulmonary tuberculosis (TB) showed a depressed IFN-gamma response to Con A and/or PWM. Only four of these TB patients also showed a depressed IFN-gamma response to PHA. Stimulation of the patients' PBL cultures with PHA in the presence of exogenous interleukin 2 (IL 2) produced normal IFN-gamma yields in all but the most severely depressed patients. PBL cultures of TB patients with defective IFN-gamma production in response to mitogenic lectins also produced less IFN-gamma after stimulation with tuberculin PPD. Although some patients showed a moderate degree of lymphopenia, their OKT4/T8 lymphocyte ratios were mostly normal or close to normal, with the notable exception of one TB patient who has been diagnosed to have the acquired immune deficiency syndrome (AIDS).

Adult↗