Effect of Deep Margin Elevation on CAD/CAM-Fabricated Ceramic Inlays.

CLINICAL RELEVANCE: Using the deep margin elevation technique in preparations extending beyond the cemento-enamel junction appears to be beneficial in maintaining structural integrity of CAD/CAM-fabricated feldspathic ceramic inlays. SUMMARY: Objective: To evaluate the effect of deep margin elevation on structural and marginal integrity of ceramic inlays.Methods and Materials: Forty extracted human third molars were collected and randomly separated into four groups (n=10/group). In group 1 (enamel margin group), the gingival margin was placed 1 mm supragingival to the cemento-enamel junction (CEJ). In group 2 (cementum margin group), the gingival margin was placed 2 mm below the CEJ. In group 3 (glass ionomer [GI] margin group), the gingival margin was placed 2 mm below the CEJ, and then the margin elevated with GI to the CEJ. In group 4 (resin-modified glass ionomer [RMGI] margin group), the gingival margin was placed 2 mm below the CEJ, and then the margin elevated with RMGI to the CEJ. Standardized ceramic class II inlays were fabricated with computer-aided design/computer-aided manufacturing and bonded to all teeth, and ceramic proximal box heights were measured. All teeth were subjected to 10,000 cycles of thermocycling (5°C/55°C) and then underwent 1,200,000 cycles of vertical chewing simulation at 50 N of force. Ceramic restorations and marginal integrity were assessed with a Hirox digital microscope. The Fisher exact test (two-tailed) with adjusted p-values (α=0.05) and logistic regression were used for statistical analysis.Results: The cementum margin group had a significantly higher ceramic fracture rate (90%) compared to other groups (10% in enamel margin and GI margin groups, p=0.007; 0% in RMGI group, p<0.001). Logistic regression showed that with increased ceramic proximal box heights, the probability of ceramic fracture increased dramatically.Conclusion: Deep marginal elevation resulted in decreased ceramic fracture when preparation margins were located below the CEJ. There was no difference found between margin elevation with GI or RMGI. Increased heights of ceramic proximal box may lead to an increased probability of ceramic fracture.

Regulation of epithelial transport and barrier function by distinct protein kinase C isoforms.

The phorbol ester phorbol 12-myristate 13-acetate (PMA) inhibits Cl(-) secretion (short-circuit current, I(sc)) and decreases barrier function (transepithelial resistance, TER) in T84 epithelia. To elucidate the role of specific protein kinase C (PKC) isoenzymes in this response, we compared PMA with two non-phorbol activators of PKC (bryostatin-1 and carbachol) and utilized three PKC inhibitors (Gö-6850, Gö-6976, and rottlerin) with different isozyme selectivity profiles. PMA sequentially inhibited cAMP-stimulated I(sc) and decreased TER, as measured by voltage-current clamp. By subcellular fractionation and Western blot, PMA (100 nM) induced sequential membrane translocation of the novel PKC epsilon followed by the conventional PKC alpha and activated both isozymes by in vitro kinase assay. PKC delta was activated by PMA but did not translocate. By immunofluorescence, PKC epsilon redistributed to the basolateral domain in response to PMA, whereas PKC alpha moved apically. Inhibition of I(sc) by PMA was prevented by the conventional and novel PKC inhibitor Gö-6850 (5 microM) but not the conventional isoform inhibitor Gö-6976 (5 microM) or the PKC delta inhibitor rottlerin (10 microM), implicating PKC epsilon in inhibition of Cl(-) secretion. In contrast, both Gö-6976 and Gö-6850 prevented the decline of TER, suggesting involvement of PKC alpha. Bryostatin-1 (100 nM) translocated PKC epsilon and PKC alpha and inhibited cAMP-elicited I(sc). However, unlike PMA, bryostatin-1 downregulated PKC alpha protein, and the decrease in TER was only transient. Carbachol (100 microM) translocated only PKC epsilon and inhibited I(sc) with no effect on TER. Gö-6850 but not Gö-6976 or rottlerin blocked bryostatin-1 and carbachol inhibition of I(sc). We conclude that basolateral translocation of PKC epsilon inhibits Cl(-) secretion, while apical translocation of PKC alpha decreases TER. These data suggest that epithelial transport and barrier function can be modulated by distinct PKC isoforms.

Coping with the cost of prescription drugs.

African Americans have higher rates of nonprescription drug utilization than white Americans, but lower rates of prescription drug use. In light of this discrepancy, this study examines 281 lower income African American households in the rural South for access to prescription drugs and coping strategies when households cannot afford prescription drugs. About half of the households could not always afford needed prescriptions, and ability to pay was related positively to Medicaid coverage. Households that could not afford prescriptions employed five strategies: (1) prioritizing, (2) financing, (3) rationing, (4) substituting, and (5) postponing. Financing, postponing, and rationing were cited most frequently. The impact of culture and areas for future research are discussed.

Nominations for excellence: collegial advocacy for nurse practitioners.

This study examined physician nomination data submitted for Syntex Nurse Practitioner of the Year Awards for 1988, 1989, and 1990. The physicians identified nurse practitioner contributions to patient care, community service/outreach, and education and research. A content analysis of the text data yielded themes within four major domains that described outstanding nurse practitioners in mutual practice relationships with physicians. The domains were clinical expertise, holistic caring, patient-centered activism, and leadership. The findings in this study indicated that physicians value the contributions of nurse practitioners that enhance the quality and scope of health care for patients within a mutual practice.

Measurements of heart scores and heart weights in horses of two different morphic body types.

Heart scores (the arithmetic mean of the QRS durations of the three bipolar limb leads for 10 cycles) and heart weights were determined from five draft type horses and five racing type horses, and evaluated for relationships between heart score and heart size within and between the two different types of horses. Horses were killed using a captive bolt gun, and actual heart weights were recorded using an electronic digital scale. The linear regression equation for heart weight versus heart score had a significant (P < 0.05) negative slope for racing types. The regression coefficients for heart weight versus heart score for draft types were not significantly (P > 0.05) different than zero. There was no significant (P > 0.05) difference found between draft and racing types. Significant (P < 0.01) differences were found between the heart ratios (heart weight as a percentage of live body weight) of racing and draft types. Heart scores were not found to be significantly (P > 0.05) different between racing and draft type horses.

The 1990s and beyond: determining the need for community health and primary care nurses for rural populations.

Increased numbers of primary care and advanced practice nurses with unique generalist skills will be required to meet the accelerating physiologic and sociocultural health care needs of rural populations. Several factors have been identified that will influence the demands and position of community-based nurses in rural practice settings during the next decade. A back-to-basics type of health care offered out of a growing elderly population; technological breakthroughs that make it possible for more chronically ill patients to live at home; serious substance abuse and other adolescent problems; AIDS; and high infant morbidity and mortality statistics are only some of the concerns that will demand nursing intervention. These changes speak to the need for improved nursing coordination, stronger collegial relationships, and better communication between physicians and nurses. Health care is moving in new directions to offer more efficient and technologically sophisticated care. These changes enhance the need for clinically expert educators who teach and jointly practice in programs with a rural focus. Telecommunications, and heightened computer literacy, will play a major role both in nursing education and clinical practice. The goals of kindergarten through 12th grade health promotion and disease prevention strategies in school health will be the norm and will require better prepared, and positions for, school nurses. More midwives and public health nurses will be needed to care for the growing population of sexually active adolescents who are in need of family planning and prenatal care. Underinsured and indigent populations will continue to fall within the purview of midlevel practitioners, as will providing anesthesia services in small rural hospitals. The transition of some rural hospitals into expanded primary care units (e.g., EACHs and RPCHs), and new models of case management will greatly influence nursing demands. This paper will further identify critical areas of advanced practice nursing within community settings, including new relationships with other health care providers, and will introduce strategies upon which rural health policy recommendations for the 1990s can be addressed.

Factors related to job satisfaction and autonomy as correlates of potential job retention for rural nurses.

This study of 167 nurses in 10 rural Georgia agencies examines the relationships among personal characteristics, factors of job satisfaction, autonomy, and job retention. The findings indicate that, contrary to expectations, personal characteristics (e.g., age, education, salary, marital status, and number of dependents) are not strong predictors of job retention in this sample. Some of the factors of job satisfaction do correlate negatively with indicators of impending job change, but the strongest relationships were those related to nursing autonomy. The study concludes that, of the variables studied, autonomy was the most effective predictor of job satisfaction and intention to remain in the current position.

Fc receptors for IgE (Fc epsilon R) on human lymphoid cells: inducible expression of Fc epsilon RII (CD23) on lymphocytes and detection by monoclonal anti-Fc epsilon RII antibody.

The studies presented herein describe (1) a sensitive, quantitative, and objective assay for detecting cell membrane-bound form of Fc receptors for IgE displayed on human lymphoid cells based on measuring unlabeled Fc epsilon R-bound IgE by a solid-phase RIA of cell lysate fluids; (2) the development and characterization of an IgM monoclonal antibody, termed 7E4, which is specific for human lymphocyte Fc epsilon RII (CD23) molecules; and (3) a system for reproducibly inducing de novo synthesis and expression of Fc epsilon RII proteins on human lymphocytes following exposure to the mitogenic lectin, pokeweed mitogen. The Fc epsilon RII molecules induced by exposure to PWM were proven to be present on lymphocytes, and not on other cell types in several ways, including (1) documenting sensitivity of such proteins to both acid pH and trypsin treatment, the latter manipulation being ineffective in removing Fc epsilon RII molecules on basophils and mast cells; (2) demonstrating specific reactivity of the expressed Fc epsilon RII molecules with the 7E4 monoclonal antibody, which is specific for human lymphocyte Fc epsilon RII molecules and does not react with Fc epsilon R molecules on other cell types; and (3) observing the required concomitant presence of both T and B lymphocytes during the induction process and proving that the induced Fc epsilon R+ cells are indeed B cells of the Leu-12+ phenotype by fluorescence analysis. The ability to induce expression of Fc epsilon RII molecules on human lymphocytes exposed to a mitogen such as PWM requires special technical attention to the method of preparation and isolation of human lymphoid cells from peripheral blood. This in vitro system for up-regulating Fc epsilon RII expression on human lymphocytes should provide us with an important new tool to analyze the participation of such cells in the regulatory mechanisms controlling the human IgE antibody system.

Cloning of cDNA coding for low-affinity Fc receptors for IgE on human T lymphocytes.

Using a cDNA probe corresponding to the membrane-bound form of the B cell receptor for IgE, we have isolated, sequenced, and expressed a cDNA clone which codes for a human T lymphocyte Fc epsilon R from HUT-78 cells. This T cell Fc epsilon R cDNA codes for 320 amino acid residues, and shows high homology to the B cell Fc epsilon R sequence. The major differences between this T cell and the B cell Fc epsilon R cDNA sequences are (i) a limited stretch of nucleotides at the 5' segment of the coding region which encodes a putative cytoplasmic region of the Fc epsilon R molecule and the untranslated 5' end; and (ii) an additional 64 bp segment in the untranslated 3' end containing two repeats in tandem with three existing repeats in the same region. The expression of Fc epsilon R on T lymphocytes may reflect involvement of the Fc epsilon R in regulation of IgE-mediated responses. The cytoplasmic difference implies functional activity of the Fc epsilon R in T lymphocytes that is mechanistically different from the Fc epsilon R of B lymphocytes.

Faculty mentorship: support for nurse practitioner students and staff within the rural community health setting.

As pointed out in the introduction, there are certain practical concepts within our base of nursing knowledge that can only be taught through experience. Many things are easier to teach by example. As we turn back the clock in nursing, we can see how Florence Nightingale, Clara Barton, and Lillian Wald were role models to their nursing peers in their era. They taught nursing by example, by role modeling their clinical expertise. Today, this model is still effective and faculty mentoring of nurse practitioner students and CHNs in a compassionate and collegial leadership results in higher quality of health care for our nation's needy clients and their families. But greater yet are the opportunities for flexible nurse practitioner faculty practice and personal interactions on many levels for nursing faculty who wish to share their expertise. Mentorship by nurse practitioner faculty for nurse practitioner students and CHNs in a rural clinical setting has revealed many positive aspects in providing quality care for rural clients and growth for nurses. Exposure to the rural community health system helps us, as nurses, to identify the many strengths it possesses for innovative rural nursing practice.

Glaucoma screening: an important role for NPs.

Glaucoma continues to be a major cause of blindness and visual impairment in the United States today. However, with early detection through screening followed by prompt treatment, sight can be spared. This article discusses the pathophysiology of both acute open-angle and acute and chronic angle-closure glaucoma and describes the high-risk population. The rationale behind obtaining an accurate intraocular pressure reading and converting the scale reading to mm Hg is explored. A step-by-step outline of the procedure for Schiotz tonometry is presented. Nurse practitioners who are functioning within primary care settings can provide valuable early detection screening to high-risk clients and make timely referrals for further evaluation.

Education of health care providers for the rural setting: a family nurse practitioner demonstration program.

Spurred by mass concern over shortages of health care providers, the country's educational system has, over the past ten years, produced an ample supply (in some areas a near glut) of health care professionals. Studies demonstrate, however, that these professionals tend to cluster in the affluent metropolitan and suburban areas. Residents of rural areas are still significantly underserved. In the healthy rural southern half of Georgia, this problem has reached a critical peak. Georgia Southern College (GSC) is a rural based college located in the heart of rural south Georgia. In order to address some of the health care problems of its constituency, GSC, with federal support, established a Nursing Department and a Family Nurse Practitioner program with a commitment to recruit nursing students from the rural area, educate them in rural settings, and provide appropriate preparation for the unique experience of working in the rural environment. The program has been very successful in producing highly skilled graduates who do stay and work in the rural areas, providing health care at reasonable costs. This paper describes the setting (rural south Georgia), the need, the program implementation, and the impact (number of graduates actually working in rural settings, and innovative projects initiated by graduates).

A preliminary analysis of accreditation criteria for surgical procedures by orthopedic residents.

The study reported here represented a preliminary evaluation of the accreditation criteria for orthopedic operative procedures. Because selection of the criteria has not been guided by empirical data, the extent to which they accurately reflect resident clinical experience is of concern. To examine this question, residents in an orthopedic residency program were tracked for one year, and their activities were compared with the procedure requirements established by the Residency Review Committee (RRC) for Orthopaedic Surgery. The results indicated that the RRC categories unduly emphasized activities for which there was little patient demand and failed to distinguish or require some frequently performed procedures. In their present form, therefore, the designated categories were not found to cover adequately the content of current clinical practice and thus may not appropriately reflect educational needs.