Comparison of Cine-MRI and Transthoracic Echocardiography for the Assessment of Aortic Root Diameters in Patients with Suspected Marfan Syndrome.

PURPOSE: Patients with Marfan syndrome require repeated imaging for monitoring of aortic root aneurysms. Therefore, we evaluated the agreement and reproducibility of cine-MRI and echocardiography measurements of the sinuses of Valsalva in patients with suspected Marfan syndrome. MATERIALS AND METHODS: 51 consecutive patients with suspected Marfan syndrome were prospectively examined using cine-MRI and echocardiography. Two readers independently measured aortic root diameters at the level of the sinuses of Valsalva in both cine-MRI and echocardiography. Statistics included intraclass correlation coefficient, Pearson correlation coefficient, Bland-Altman analysis, and two-sided t-test. RESULTS: In 38 of the 51 individuals (74.5 %), the diagnosis of Marfan syndrome was established according to the criteria of the Ghent-2 nosology. Cine-MRI measurements of the sinuses of Valsalva revealed a strong correlation with echocardiography (r = 0.929), but a statistically significant bias of -1.0  mm (p < 0.001). The mean absolute diameter for sinuses of Valsalva obtained by cine-MRI was 32.3  ±  5.8 mm as compared to 33.4  ±  5.4 mm obtained by echocardiography. Interobserver agreement of measurements of the sinuses of Valsalva was higher for cine-MRI than for echocardiography (p = 0.029). CONCLUSION: Despite small, but statistically significant differences in terms of agreement and reproducibility, cine-MRI and echocardiographic measurements of aortic root diameters provide comparable results without a significant clinical difference. Therefore both techniques may be used for monitoring of the aortic root in patients with Marfan syndrome.

Quantitative assessment of bone marrow attenuation values at MDCT: an objective tool for the detection of bone bruise related to occult sacral insufficiency fractures.

OBJECTIVES: To prove the feasibility of using Hounsfield attenuation values at MDCT to detect bone bruises related to sacral insufficiency fractures. METHODS: Twenty-two patients with acute sacrum trauma and no fracture findings at MDCT were included in our prospective study. Two observers independently reviewed CTs regarding visual signs of bone bruises in 132 defined regions of the sacral alae. Interobserver agreement was tested by κ statistics. Subsequently, HU values were obtained in the same regions, and attenuation differences between the two sides were calculated. Validity and reliability were assessed by intraclass correlation coefficient and Bland-Altman analysis. HU differences were subjected to ROC curve analysis to determine sensitivity, specificity, PPV and NPV. MRI served as standard reference. RESULTS: MRI revealed 19 regions with bone bruises and associated sacral insufficiency fractures. HU measurements demonstrated good validity and reliability (r = 0.989). ROC curve analysis exhibited an ideal cutoff value of 35.7 HU density difference between affected and non-affected regions. Visual evaluation revealed moderate agreement (κ = 0.48); diagnostic accuracy was inferior to objective evaluation. CONCLUSIONS: Assessment of differences in bone marrow density by HU measurements is an objective and reliable tool for detection of bone bruises associated with occult sacral insufficiency fractures. KEY POINTS : • Bone bruising is associated with occult sacral insufficiency fractures. • Assessment of differences in bone marrow CT attenuation appears valid and reliable. • Comparative HU measurements of bone marrow allow detection of bone bruises. • Comparative HU measurements have high specificity and negative predictive values. • Comparative HU measurements may make further diagnostic workup with MRI unnecessary.

Dimensions of socioeconomic position related to body mass index and obesity among Danish women and men.

AIMS: The aim of this study was to examine the association between different dimensions of socioeconomic position, body mass index (BMI) and obesity in the Danish population. Possible interactions between the different dimensions and gender differences were also investigated. METHODS: This was a cross-sectional survey conducted in 2000-2002 including a simple random sample from the civil registration system, comprising 1953 males and 2167 females aged 4-75 years. Information about different dimensions of socioeconomic position, height and weight was obtained by face-to-face interview. Associations between dimensions of socioeconomic position and weight status were examined by use of linear multiple regression analysis and logistic regression analysis. RESULTS: BMI and prevalence of obesity were significantly associated with education for both men and women. Odds ratios (ORs) for obesity were 2.9 (95% confidence interval (CI) 1.4-5.9) and 6.5 (95% CI 2.3-18.7) for those with basic school as compared with those with long higher education for men and women, respectively. Women outside the labour market had higher BMIs and a greater prevalence of obesity (OR 2.5 (95% CI 1.6-3.9)) after adjustment for educational level. CONCLUSIONS: Education was the dimension most consistently associated with BMI and obesity, indicating the importance of cultural capital for weight status. The gender-specific pattern showed a stronger social gradient for women, and indicated that a high relative body weight was associated with less favourable social and material conditions for women, but not for men. A public health strategy to prevent and reduce obesity should be gender-specific, focus on groups with short education, and incorporate cultural norms.

Assessment of myocardial viability in ischemic heart disease by cardiac magnetic resonance imaging.

Assessment of myocardial viability aims at differentiating between viable and non-viable myocardium. The proof of dysfunctional but viable myocardium is crucial to predict outcome of revascularization after acute (AMI) and chronic myocardial infarction (CMI). Cardiac magnetic resonance imaging (CMRI) offers different options to detect viable myocardium: Measurements of end-diastolic wall thickness by cine-CMRI can be used to depict chronically scarred myocardium, but fails to detect acute myocardial necrosis. Low-dose dobutamine stimulation (LDDS) cine-CMRI analyses the contractile reserve of dysfunctional but viable myocardium under pharmacologic stimulus to identify viable myocardium in AMI and CMI with high specificity. Sensitivity of LDDS cine-CMRI is superior to LDDS echocardiography but reduced in patients with severely impaired left ventricular (LV) function. The delayed-enhancement (DE) technique directly visualises non-viable myocardium due to an altered contrast-media distribution in necrotic and fibrotic tissue. DE-CMRI identifies non-viable myocardium with high spatial resolution independently from LV function. The transmural extent of contrast enhancement in DE-CMRI is used to predict functional recovery after revascularization in AMI and CMI. Furthermore, the amount and pattern of contrast enhancement in DE-CMRI provide important prognostic information in both entities. Recent studies demonstrated the superiority of DE-CMRI compared to single photon emission tomography (SPECT) and positron emission tomography (PET) to assess myocardial viability. Therefore, DE-CMRI is currently recognised as the standard of reference for assessment of myocardial viability. The technical background, clinical application and accuracy of the different CMRI techniques to assess myocardial viability in AMI and CMI are discussed in this work.

Epidemiology and management of infectious diseases in international adoptees.

International adoptees represent a group of children with unique health care needs. Data from published studies, along with the recent experience of the Yale International Adoption Clinic, suggest that the risk of serious infections in adoptees is low, although infections associated with institutionalization still occur commonly. Interpretation of these data must be undertaken with caution, however, since many, if not most, international adoptees are not evaluated in specialty clinics. Thus, prospective studies designed to minimize selection and referral bias are needed in order to accurately define the risk of infectious and noninfectious diseases in all international adoptees.

Determination of conformational equilibrium of peptides in solution by NMR spectroscopy and theoretical conformational analysis: application to the calibration of mean-field solvation models.

Peptides occur in solution as ensembles of conformations rather than in a fixed conformation. The existing energy functions are usually inadequate to predict the conformational equilibrium in solution, because of failure to account properly for solvation, if the solvent is not considered explicitly (which is usually prohibitively expensive). NMR data are therefore widely incorporated into theoretical conformational analysis. Because of conformational flexibility, restrained molecular dynamics (with restraints derived from NMR data), which is usually applied to determine protein conformation is of limited use in the case of peptides. Instead, (a) the restraints are averaged within predefined time windows during molecular dynamics (MD) simulations (time averaging), (b) multiple-copy MD simulations are carried out and the restraints are averaged over the copies (ensemble averaging), or (c) a representative ensemble of sterically feasible conformations is generated and the weights of the conformations are then fitted so that the computed average observables match the experimental data (weight fitting). All these approaches are briefly discussed in this article. If an adequate force field is used, conformations with large statistical weights obtained from the weight-fitting procedure should also have low energies, which can be implemented in force field calibration. Such a procedure is particularly attractive regarding the parameterization of the solvation energy in nonaqueous solvents, e.g., dimethyl sulfoxide, for which thermodynamic solvation data are scarce. A method for calibration of solvation parameters in dimethyl sulfoxide, which is based on this principle was recently proposed by C. Baysal and H. Meirovitch (Journal of the American Chemical Society, 1998, Vol. 120, pp. 800--812), in which the energy gap between the conformations compatible with NMR data and the alternative conformations is maximized. In this work we propose an alternative method based on the principle that the best-fitting statistical weights of conformations should match the Boltzmann weights computed with the force field applied. Preliminary results obtained using three test peptides of varying conformational mobility: H-Ser(1)-Pro(2)-Lys(3)-Leu(4)-OH, Ac-Tyr(1)-D-Phe(2)-Ser(3)-Pro(4)-Lys(5)-Leu(6)-NH(2), and cyclo(Tyr(1)-D-Phe(2)-Ser(3)-Pro(4)-Lys(5)-Leu(6)) are presented.

[Trends in dietary habits in Denmark and Sweden since the 1960s]. / Udviklingen i kostvaner i Danmark og Sverige siden 1960'erne.

Dietary habits in Denmark and Sweden are compared during the period 1965-1998 based on data from Food Balance Sheets. Common trends are an increase in consumption of vegetables, fruits, berries and meat and a decrease in consumption of fats. In the latest ten years percentage of energy from fat has also decreased. Denmark has a higher consumption of fats and meat and a lower consumption of fruits, berries and fish. These differences contribute to a higher percentage of energy from fat in the Danish diet compared to the Swedish. Data consequently indicate that dietary habits in Sweden are healthier than in Denmark. Differences in dietary habits may have contributed to differences in life expectancy between the countries. Disparities in dietary habits are seen in both countries. The tendency is greater social differences in Denmark.

A systematic review of socio-economic differences in food habits in Europe: consumption of fruit and vegetables.

OBJECTIVE: To evaluate the differences in the consumption of fruit and vegetables between groups with different socio-economic status (SES) in the adult population of European countries. DESIGN: A systematic review of published and unpublished surveys of food habits conducted between 1985 and 1999 in 15 European countries. Educational level and occupational status were used as indicators of SES. A pooled estimate of the mean difference between the highest and the lowest level of education and occupation was calculated separately for men and women, using DerSimonian and Laird's random effects model. SETTING: The inclusion criteria of studies were: use of a validated method for assessing intake at the individual level; selection of a nationwide sample or a representative sample of a region; and providing the mean and standard deviation of overall fruit and vegetable consumption for each level of education or occupation, and separately for men and women. SUBJECTS: Participants in the individual surveys had to be adults (18-85 y). RESULTS: Eleven studies from seven countries met the criteria for being included in the meta-analysis. A higher SES was associated with a greater consumption of both fruit and vegetables. The pooled estimate of the difference in the intake of fruit was 24.3 g/person/day (95% confidence interval (CI) 14.0-34.7) between men in the highest level of education and those in the lowest level of education. Similarly, this difference was 33.6 g/person/day for women (95% CI 22.5-44.8). The differences regarding vegetables were 17.0 g/person/day (95% CI 8.6-25.5) for men and 13.4 g/person/day (95% CI 7.1-19.7) for women. The results were in the same direction when occupation instead of education was used as an indicator of SES. CONCLUSIONS: Although we cannot exclude over-reporting of intake by those with highest SES, it is unlikely that this potential bias could fully explain the differences we have found. Our results suggest that an unhealthier nutrition pattern may exist among adults belonging to lower socio-economic levels in Europe. SPONSORSHIP: The present study was supported by the European Union's FAIR programme (FAIR-97-3096).

Design of a knowledge-based force field for off-lattice simulations of protein structure.

Prediction of protein structure from amino-acid sequence still continues to be an unsolved problem of theoretical molecular biology. One approach to solve it is to construct an appropriate (free) energy function that recognizes the native structures of some selected proteins (whose native structures are known) as the ones distinctively lowest in (free) energy and then to carry out a search of the lowest-energy structure of a new protein. In order to reduce the complexity of the problem and the cost of energy evaluation, the so-called united-residue representation of the polypeptide chain is often applied, in which each amino-acid residue is represented by only a few interaction sites. Once the global energy minimum of the simplified chain has been found, the all-atom structure can easily and reliably be constructed. The search of the lowest-energy structure is usually carried out by means of Monte Carlo methods, though use of more efficient global-optimization methods, especially those of deformation of original energy surface is potentially promising. Monte Carlo search of the conformational space can be accelerated greatly, if the chain is superposed on a discrete lattice (the on-lattice approach). On the other hand, the on-lattice approach prohibits the use of many efficient global-optimization methods, because they require both energy and its space derivatives. The on-lattice methods in which the chain is embedded in the continuous 3D space are, therefore, also worth developing. In this paper we summarize the work on the design and implementation of an off-lattice united-residue force field that is underway in our group, in cooperation with Professor HA. Scheraga of Cornell University, U.S.A.

[Diet and health behaviour in Danish children aged 11-15 years]. / Spisevaner og sundhedsadfaerd blandt 11-15 årige.

A total of 1,671 school children aged 11, 13 and 15 years answered a questionnaire on diet, other health behaviour, social background, social network, health and life satisfaction. The proportions who ate fruit, vegetables, and rye bread every day were 77%, 64% and 94%. Moreover, 78% had fibre-containing breakfast every day and 79% had a regular lunch meal every day. 26% of the children received an optimal diet containing all of these five components every day, and 19% received less than three of these components every day. The proportions who consumed five unhealthy diet components every day (candy, chips, French fries, sausages/hamburgers, and sweet long-drinks) were 32%, 12%, 5%, 5% and 18%. 39% received at least one of these unhealthy diet components every day. There was no association between intake of healthy and intake of unhealthy diet components. We found no age differences among boys regarding the healthy diet components but an increasing consumption of unhealthy components with increasing age. Among girls we found a decreasing consumption of both healthy and unhealthy components with increasing age. Healthy diet was associated with high social class, good health, positive life satisfaction, positive school assimilation, and positive health behaviour.