Microleakage and Resin-to-Dentin Interface Morphology of Pre-Etching versus Self-Etching Adhesive Systems.

The purpose of this study was to compare the microleakage and tissue-adhesive interface morphology from Class V restorations using different systems of dentin adhesives. Class V cavities were prepared on buccal surfaces of 27 extracted caries-free molars and premolars. Teeth were randomly assigned to one of three groups: (1) Prime & Bond NT, a 5(th) generation system using an initial step of total etch followed by a second step of application of a self bonding primer (2) Clearfil SE Bond, a 5(th) generation adhesive system employing two separate steps of self-etch priming and subsequent bonding (3) One-up Bond F, a 6(th) generation one step self-etching, self-priming and self-bonding adhesive. Microleakage and interface morphology of teeth restored with these adhesives and a composite resin were evaluated. Kruskal-Wallis Test (p = 0.05) was used to analyze the results. SEM analysis was used to relate interface morphology to microleakage. The mean and (SD) values of microleakage were: Prime and Bond NT: 0.15 (0.33), Clearfil SE Bond: 0.06 (0.17) and One-up Bond F: 2.96 (0.63). The mean microleakage for One-up Bond was significantly higher than for the other groups (p<0.05). Protruding tags in dentin channels were observed in Prime and Bond and Clearfil systems, but not in One-up Bond. The single step adhesive system, although more convenient for the clinician, uses a low viscosity formulation difficult to keep in place on cavity walls. It also tends to be too aggressive and hydrophilic to create an impermeable hybridized tissue-adhesive interfacial layer resistant to microleakage. Two-step adhesive systems, on the other hand, were retained on all segments of the cavosurface during application, and formed a hybridized interfacial layer resistant to microleakage.

The West Nile virus encephalitis outbreak in the United States (1999-2000): from Flushing, New York, to beyond its borders.

Viruses cause most forms of encephalitis. The two main types responsible for epidemic encephalitis are enteroviruses and arboviruses. The City of New York reports about 10 cases of encephalitis yearly. Establishing a diagnosis is often difficult. In August 1999, a cluster of five patients with fever, confusion, and weakness were admitted to a community hospital in Flushing, New York. Flaccid paralysis developed in four of the five patients, and they required ventilatory support. Three, less severe, cases presented later in the same month. An investigation was conducted by the NewYork City (NYC) and New York State (NYS) health departments and the national Centers for Disease Control and Prevention (CDC). The West Nile virus (WNV) was identified as the etiologic agent. WNV is an arthropod-borne flavivirus, with a geographic distribution in Africa, the Middle East, and southwestern Asia. It has also been isolated in Australia and sporadically in Europe but never in the Americas. The majority of people infected have no symptoms. Fever, severe myalgias, headache, conjunctivitis, lymphadenopathy, and a roseolar rash can occur. Rarely, encephalitis or meningitis is seen. The NYC outbreak resulted in the first cases of WNV infection in the Western Hemisphere and the first arboviral infection in NYC since yellow fever in the nineteenth century. The WNV is now a public health concern in the United States.

The West Nile Virus outbreak of 1999 in New York: the Flushing Hospital experience.

West Nile Virus (WNV) is a mosquito-borne flavivirus, which has been known to cause human infection in Africa, the Middle East, and southwestern Asia. It has also been isolated in Australia and sporadically in Europe but never in the Americas. Clinical features include acute fever, severe myalgias, headache, conjunctivitis, lymphadenopathy, and a roseolar rash. Rarely is encephalitis or meningitis seen. During the month of August 1999, a cluster of 5 patients with fever, confusion, and weakness were admitted to the intensive care unit of the same hospital in New York City. Ultimately 4 of the 5 developed flaccid paralysis and required ventilatory support. Three patients with less-severe cases presented shortly thereafter. With the assistance of the New York City and New York State health departments and the Centers for Disease Control and Prevention, these were documented as the first cases of WNV infection on this continent.

Magnetic resonance angiography of dialysis access shunts: initial results.

The objective of this study was the feasibility of imaging hemodialysis fistulae with magnetic resonance angiography (MRA). MRA was performed in eight Brescia-Cimino fistulae and seven goretex loop grafts, five of which were stenosed and 10 normal. We compared two MRA methods: a 2D magnetization prepared turbo field echo (MPTFE) and a 3D phase contrast (PC) sequence. Digital subtraction angiography served as the gold standard. MPTFE MRA provided satisfactory quality images of the entire fistula in 14 out of 15 cases, and PC MRA in 9 of 15 cases (p < .05). MPTFE MRA identified all eight stenoses with one false-positive result. PC MRA identified seven of eight stenoses with two false positives. It is feasible to obtain diagnostic images of dialysis fistulae with MRA.

Regional diastolic wall motion dynamics in anterior myocardial infarction: analysis and quantification with magnetic resonance imaging.

BACKGROUND: Regional variability in systolic and diastolic cardiac function occurs in most cardiac disorders. The influence of this regional functional heterogeneity on global function is not well understood and is difficult to study with the common imaging modalities. METHODS: A midventricular short axis slice of the left ventricle was obtained with ECG-triggered magnetic resonance imaging in eight infarct patients and 10 control volunteers. The variation in wall thickness and slice cavity volume during the cycle was studied using the centreline method. RESULTS: The peak filling rate was significantly decreased in the infarct group (96 versus 58 cm3/s, P < 0.005). In addition, a small contribution of other parameters, such as the time to end systole, the isovolumic relaxation time, and the duration and extent of early filling, was also shown by linear discriminant analysis. Analysis of the regional parameters demonstrated an increased asynchronicity of contraction (64 versus 37 ms, P < 0.01) as well as relaxation (88 versus 51 ms, P < 0.01) in patients with myocardial infarction. On comparison of the anterior (infarcted) and inferior (non-infarcted) parts of the left ventricle, the difference was present only in the infarct region. CONCLUSION: Magnetic resonance imaging of the heart allows evaluation of the relationship between regional differences in wall motion dynamics and global parameters of diastolic function in infarct patients.

Low-dosage dobutamine magnetic resonance imaging as an alternative to echocardiography in the detection of viable myocardium after acute infarction.

The objective of this study was the evaluation of the feasibility of magnetic resonance (MR) imaging of the heart with low-dosage dobutamine stimulation for the detection of viability after acute myocardial infarction. Gradient echo MR images were obtained in 37 patients with recent myocardial infarction. Images of wall motion abnormalities and their reaction to low-dosage dobutamine stimulation were analyzed and compared with two-dimensional echocardiograms. Follow-up echocardiography at 3 to 6 months was available in 24 patients. Concordant diagnosis of viability between the two techniques was obtained in 30 (81%) of 37 patients. MR correctly predicted evolution of wall motion in 19 (79%) of 24 patients, a result not significantly different from echocardiography: 20 (83%) of 24. It was concluded that low-dosage dobutamine MR imaging is a safe alternative to echocardiography to predict recovery of wall motion abnormalities after myocardial infarction.

Left ventricular wall motion analysis in patients with acute myocardial infarction using magnetic resonance imaging.

Dynamic magnetic resonance (MR) imaging of the left ventricle was performed in 13 patients with acute myocardial infarction and in 11 healthy volunteers. Visual assessment of cine MR video loops correctly located the infarction of 12 of 13 patients. Quantitative analysis of absolute and relative wall thickening, area ejection fraction, and radial shortening fraction accurately distinguished hearts with and without infarction (p < .001). This distinction could also be made using the number of segments with decreased and the number of segments with decreased + increased wall motion (p < .001). Localization of the infarction by quantitative MR methods was limited, probably due to relative low temporal resolution. Combined evaluation of qualitative and quantitative MR imaging data provides useful information on wall motion dynamics after acute myocardial infarction.

Mortality among workers in the Florida phosphate industry. I. Industry-wide cause-specific mortality patterns.

A retrospective cohort mortality study was conducted on 17,601 white and 4,722 nonwhite male workers in the Florida phosphate mining and chemical processing industry. Concerns about potential risks from naturally-occurring sources of ionizing radiation and anecdotal reports of lung cancer among workers prompted this investigation. Historical follow-up was conducted for the years 1949 to 1978. In comparison with U.S. rates, small excess of mortality rates of lung cancer were observed for white (standardized mortality ratio [SMR] equals 1.22) and nonwhite workers (SMR = 1.24); however, these excesses disappeared when contrasts were made with prevailing rates in Florida. Emphysema mortality was also slightly elevated in comparison with U.S. rates; the SMRs were 1.48 and 1.73 for white and nonwhite workers, respectively. Neither disease was related to overall length of employment. Detailed analyses of mortality in relation to work assignments are presented in the companion article.

Mortality among workers in the Florida phosphate industry. II. Cause-specific mortality relationships with work areas and exposures.

Small excesses of lung cancer and emphysema mortality had been detected among an historical cohort of 17,601 white and 4,722 nonwhite Florida phosphate industry workers. Internal mortality rate comparisons were made between worker subcohorts classified according to length of employment in 16 work areas and according to employment duration in jobs grouped by potential exposures to 10 agents, including alpha radiation. The only consistent associations seen were increased lung cancer mortality rates among long-term workers in plant-wide services and skilled crafts jobs. There was no evidence to support causal associations with exposures characteristic of the phosphate industry.

Assessing the possible extent of confounding in occupational case-referent studies.

Case-referent studies nested within occupational cohort studies are efficient designs for estimating relative risks associated with exposures and for obtaining data on nonoccupational confounding factors. Frequently, however, only incomplete data on confounders can be obtained from sources such as next-of-kin or co-workers. A method for assessing the potential extent of confounding in cohort studies described previously by Axelson [Scand J Work Environ Health 4 (1978) 98-102] can be adapted for use in nested case-referent studies. An example is shown to illustrate that the adapted Axelson method is preferable to the usual confounder adjustment techniques when data on the confounder are incomplete.

Nutrient intakes among selected North American populations in the Lipid Research Clinics Prevalence Study: composition of fat intake.

Components of fat and their relationship to total energy are described for 2,368 white male and 2,200 white female adults, aged 20-59 years, for whom 24-hour dietary recalls were completed between 1972 and 1975 in nine North American populations as a part of the Lipid Research Clinics (LRC) Program Prevalence Study. Men had higher absolute intakes of total fat and cholesterol than women, although both sexes consumed diets similar in relative composition of polyunsaturated, saturated, and monounsaturated fatty acids. Marked geographical differences in intakes of energy, total fat, and dietary cholesterol were observed. Compared with data from dietary surveys conducted in the 1960's the LRC data showed that consumption of cholesterol had decreased by the early 1970's, whereas consumption of polyunsaturated fatty acids appears to have increased, resulting in a higher ratio of polyunsaturated to saturated fatty acids. However, comparison of current dietary guidelines with these data, which are based on a single dietary recall, showed that few LRC participants met the recommendations of the Senate Select Committee on Nutrition and Human needs for dietary fat intake.

Miliary pustular syphilid.

A case of secondary syphilis is presented in which a dramatic generalized eruption of pustules and an elevated temperature were prominent features. Biopsy of the skin lesions showed dermal granulomata, which are occasionally seen in the papulopustular lesions of secondary syphilis. The classification of pustular syphilids is reviewed.

Relationships of nutrient intake to lipids and lipoproteins in 1234 white children. The Lipid Research Clinics Prevalence Study.

Using the geographically and socioeconomically varied collaborative Lipid Research Clinics Prevalence Study data, this report focuses upon relationships between dietary intake and plasma lipids and lipoproteins in 1234 white children, 661 boys and 573 girls, aged 6-19 years who were sampled in a random recall (Visit 2) from large populations in six Lipid Research Clinics. Using multiple regression analysis, we found that in 6- to 12-year-old boys the dietary polyunsaturated-to-saturated fat ratio was inversely associated with plasma total and low density lipoprotein cholesterol and dietary cholesterol was positively associated with plasma high density lipoprotein cholesterol. In 13- to 19-year-old boys, high density lipoprotein cholesterol and the ratio of high density lipoprotein cholesterol to total cholesterol were inversely related to sucrose intake. In 6- to 12-year-old girls, plasma triglycerides were positively related to dietary sucrose. Using analysis of covariance in children having the lowest, middle, and top decile nutrient intakes, we found that higher carbohydrate intakes were associated with lower plasma total cholesterol in boys. The highest polyunsaturated fat intake (in 6- to 12-year-old girls) was associated with the lowest plasma cholesterol and very low density lipoprotein cholesterol. The highest cholesterol intake (in 6- to 12-year-old boys) was associated with the highest high density lipoprotein cholesterol levels. In girls, the highest sucrose intakes were associated with the highest plasma triglyceride levels. We conclude that the weak, but statistically significant, associations that we observed were meaningful relative to etiologies of nutrient-lipoprotein interrelationships, and should be useful in forming new hypotheses for focused metabolic ward studies.

Warty dyskeratoma.

A 43-year-old man with a crusted papule on the cheek was found to have a squamous cell carcinoma of the lung. Histologic examination of the skin lesion showed the characteristic features of warty dyskeratoma. A rare clinical photograph is presented and the clinical and histopathologic features are reviewed.

Grouping and linear regression.

With a large number of observations, the method of grouping is often employed to provide simpler graphs or tables. When one investigates the relationship between two variables, one usually groups based on the magnitude of the independent variable, and then plots the dependent variable averages against independent variable averages to get a clearer graph. If grouping is based on the magnitude of the dependent variable, the plot of group means as indicated above does not appropriately describe the relationship of the dependent variable to the independent variable. These results are demonstrated theoretically for the special case of bivariate normality (and thus linear regression), but would be expected to be similar for other distribution assumptions. An example is given from an epidemiological study.

Lichen striatus with onychodystrophy.

Two case reports of lichen striatus with nail dystrophy are presented herein. Review of the literature suggests a more protracted course for the cutaneous eruption if there is nail involvement. Biopsy is important to differentiate this condition from other linear lesions that may interfere with normal nail growth.

Common methods, different populations. The Lipid Research Clinics Program Prevalence Study.

The salient characteristics of the Lipid Research Clinics (LRC) Program Prevalence Study are presented, including an overview of its structure, the populations included and the common procedures used. Highlighted are the two sequential screening examinations that included 68,317 participants in 12 LRCs in the U.S. Canada and the U.S.S.R. for the first examination and 15,816 for the second. Several thousand more will be added as the thirteenth LRC completes its screening in Israel. Major data items are described briefly, as are data quality enhancement procedures. Procedures for plasma lipid determination, lipoprotein cholesterol, other clinical chemistries, nutritional intake assessment, and resting and stress electrocardiography are discussed. A discussion of the methodologic strengths and weaknesses of the findings of the LRC Program Prevalence Study is also included. This paper provides a frame of reference for the individual papers in this volume.

Associations of plasma high-density lipoprotein cholesterol with clinical chemistry data.

We examined data from the participants in the Lipid Research Clinics Program Prevalence Study for associations between high-density lipoprotein (HDL) cholesterol and clinical chemistry tests. There is a negative relationship between serum thyroxine and HDL cholesterol: men 20-69 years and women 20-44 years with low thyroxine levels have significantly higher HDL cholesterol than those with high thyroxine levels. Women 45-69 years with hyperglobulinemia (> 3.2 g/dl) have significantly lower HDL cholesterol levels than those with lower globulin levels. There is a weak negative association between HDL cholesterol and serum uric acid in men 20-44 years and a stronger association in women. A weak negative association between HDL cholesterol and plasma glucose is present only in men 20-44 years and women 45-69 years. Subjects with high serum bilirubin or serum aspartate aminotransferase (AST, SGOT) values have higher HDL cholesterol levels that are statistically significant in men 20-69 years and women 20-44 years (bilirubin) and men 45-69 years and women 45-69 years (AST). There is a negative association between alkaline phosphatase and HDL cholesterol in women and young men. These results suggest that thyroid hormones may be involved in the regulation of HDL cholesterol, and that there are associations between HDL cholesterol and the clinical chemistry tests that are not necessarily explained by disease. However, in the whole population, the plasma constituents measured as clinical chemistry tests, or the mechanisms that regulate their levels, are not important determinants of plasma HDL cholesterol levels.