Weight fluctuation, mortality, and cardiovascular disease in adults in 18 years of follow-up: Tehran Lipid and Glucose Study.

PURPOSE: Controversies exist in the effect of body weight loss and fluctuation on cardiovascular disease (CVD) and mortality. This study aims to assess the effect of weight variability on CVD and all-cause and cardiovascular mortality in the Tehran Lipid and Glucose Study (TLGS) cohort. METHOD: Participants aged ≥ 40 year at the baseline period with at least 3 BMI measurements were included in this study. After excluding individuals with cancer, CVD, end-stage renal disease, systemic use of glucocorticoids, pregnancy, and missing covariates at the baseline, a total of 3461 participants were enrolled and followed for 18 years. BMI variability was defined using root mean squared error (RMSE) and average successive variability (ASV). In the RMSE method, BMI variability was calculated using the best-fitting model for BMI trend of each subject. Multivariate Cox proportional hazard models were applied to assess BMI variability's effect on CVD and mortality. RESULTS: Among the 3461 participants in this study, the group with the highest weight variability had an increased risk of death for all-cause (HR 1.65; 95% CI 1.21-2.25), non-cardiovascular (HR 1.77; 95% CI 1.24-2.53), and non-cancer (HR 1.77; 95% CI 1.25-2.50) mortality. However, BMI variability showed to be protective against CVD (HR 0.76; 95% CI 0.6-0.97). These findings were significant in males, non-smokers, participants with age ≤ 60 year, BMI < 30, negative BMI slope, and both diabetic and non-diabetic subjects. CONCLUSION: High BMI variability is associated with increased risk of all-cause, non-CVD, and non-cancer mortality, although protective for the CVD event. Appropriate strategies for body weight maintenance after weight loss could be adopted to avoid weight variability, particularly in non-obese subjects.

Bleaching effects of massecuite on some properties of crystallized sugar beet and milk chocolate bars produced.

Four kinds of bleached, unbleached, second and third crystal sugars (BCS, UCS, SCS and TCS) were made from different massecuites in a sugar-beet factory, and their physiochemical (polarization, invert sugar, colorants, pH, ash and SO2), microbiological and functional properties were measured. While the polarization of UCS, SCS and TCS were lower than BCS; their invert sucrose, colorants, pH and ash contents were significantly higher than BCS. The phenols and betaine of BCS, UCS, SCS, and TCS were 144, 401, 384 and 673 (mg/100 g); and 244, 791, 4662, and 6589 (mg/100 g); respectively. Whereas the phenol of milk chocolate bars (MCB) made with UCS, SCS, and TCS were only 10% higher than MCB completed with BCS; their betaine contents were substantially (up to 16 times) higher than the ones finished with BCS. Sensory evaluation showed that the MCB prepared with three sugars including UCS, SCS and TCS had significantly higher glossiness, brittleness, flavor and mouth feel than those made with BCS. The greater colorants, ash content and inverted sugars of UCS, SCS and TCS (in comparison with BCS) made considerable improvements in the glossiness, flavor and brittleness of MCB, respectively. BCS had 8 ppm of toxic sulfur; whereas, UCS, SCS and TCS had no detectable sulfur and significantly higher beneficial copper content than BCS. No pathogenic microorganism were detected in UCS, SCS, TCS or their subsequent MCB. Our results highly recommend using UCS, SCS and TCS instead of BCS in food products (such as MCB) due to their higher health benefits.

A comparison of direct and iterative finite element inversion techniques in dynamic elastography.

As part of tissue elasticity imaging or elastography, an inverse problem needs to be solved to find the elasticity distribution from the measured displacements. The finite element method (FEM) is a common method for solving the inverse problem in dynamic elastography. This problem has been solved with both direct and iterative FEM schemes. Each of these methods has its own advantages and disadvantages which are examined in this paper. Choosing the data resolution and the excitation frequency are critical for achieving the best estimation of the tissue elasticity in FEM methods. In this paper we investigate the performance of both direct and iterative FEMs for different ranges of excitation frequency. A new form of iterative method is suggested here which requires a lower mesh density compared to the original form. Also two forms of the direct method are compared in this paper: one using the exact fit for derivatives calculation and the other using the least squares fit. We also perform a study on the spatial resolution of these methods using simulations. The comparison is also validated using a phantom experiment. The results suggest that the direct method with least squares fit is more robust to noise compared to other methods but has slightly lower resolution results. For example, for the homogenous region with 20 dB noise added to the data, the RMS error for the direct method with least squares fit is approximately half of the iterative method. It was observed that the ratio of voxel size to the wavelength should be within a specific range for the results to be reliable. For example for the direct method with least squares fit, for the case of 20 dB noise level, this ratio should be between 0.1 to 0.2. On balance, considering the much higher computational cost of the iterative method, the dependency of the iterative method on the initial guess, and the greater robustness of the direct method to noise, we suggest using the direct method with least squares fit for linear elasticity cases.

Direct vibro-elastography FEM inversion in Cartesian and cylindrical coordinate systems without the local homogeneity assumption.

To produce images of tissue elasticity, the vibro-elastography technique involves applying a steady-state multi-frequency vibration to tissue, estimating displacements from ultrasound echo data, and using the estimated displacements in an inverse elasticity problem with the shear modulus spatial distribution as the unknown. In order to fully solve the inverse problem, all three displacement components are required. However, using ultrasound, the axial component of the displacement is measured much more accurately than the other directions. Therefore, simplifying assumptions must be used in this case. Usually, the equations of motion are transformed into a Helmholtz equation by assuming tissue incompressibility and local homogeneity. The local homogeneity assumption causes significant imaging artifacts in areas of varying elasticity. In this paper, we remove the local homogeneity assumption. In particular we introduce a new finite element based direct inversion technique in which only the coupling terms in the equation of motion are ignored, so it can be used with only one component of the displacement. Both Cartesian and cylindrical coordinate systems are considered. The use of multi-frequency excitation also allows us to obtain multiple measurements and reduce artifacts in areas where the displacement of one frequency is close to zero. The proposed method was tested in simulations and experiments against a conventional approach in which the local homogeneity is used. The results show significant improvements in elasticity imaging with the new method compared to previous methods that assumes local homogeneity. For example in simulations, the contrast to noise ratio (CNR) for the region with spherical inclusion increases from an average value of 1.5-17 after using the proposed method instead of the local inversion with homogeneity assumption, and similarly in the prostate phantom experiment, the CNR improved from an average value of 1.6 to about 20.

Sparsity regularization in dynamic elastography.

We consider the inverse problem of continuum mechanics with the tissue deformation described by a mixed displacement-pressure finite element formulation. The mixed formulation is used to model nearly incompressible materials by simultaneously solving for both elasticity and pressure distributions. To improve numerical conditioning, a common solution to this problem is to use regularization to constrain the solutions of the inverse problem. We present a sparsity regularization technique that uses the discrete cosine transform to transform the elasticity and pressure fields to a sparse domain in which a smaller number of unknowns is required to represent the original field. We evaluate the approach by solving the dynamic elastography problem for synthetic data using such a mixed finite element technique, assuming time harmonic motion, and linear, isotropic and elastic behavior for the tissue. We compare our simulation results to those obtained using the more common Tikhonov regularization. We show that the sparsity regularization is less dependent on boundary conditions, less influenced by noise, requires no parameter tuning and is computationally faster. The algorithm has been tested on magnetic resonance elastography data captured from a CIRS elastography phantom with similar results as the simulation.

Review of the relationship between milk urea nitrogen and days in milk, parity, and monthly temperature mean in Iranian Holstein cows.

The objectives of this study were to determine the relationships between milk urea N and days in milk, parity, and season in Iranian Holstein cows. Twelve Iranian commercial dairy herds participated in a 13-mo study from December 1, 2008, to December 31, 2009. All cows were milked 3 times daily, housed in freestalls, and fed a total mixed ration twice a day. Mean milk urea N over the study period was 16.0mg/dL. Mean milk urea N, categorized by 30-d increments of days in milk, paralleled changes in milk values and followed a curvilinear shape. However, milk urea N concentration reached a maximum at the fifth month of days in milk, but milk production reached a maximum at the third month. The concentration of milk urea N was lower during the first 30 d in milk category compared with all other days in milk categories. Overall mean milk urea N concentration of Holstein cows in the third and greater lactations was lower than in the first or second lactation. Milk urea N was at its lowest level in December (13 mg/dL), increased in the spring and summer months, and reached a maximum in July (18.8 mg/dL). From that point, milk urea N concentration progressively diminished to the autumn-winter level. In this study, milk urea N concentration was positively correlated with monthly temperature mean and may be a reason for the lower reproductive performance during the summer months. It has been recommended that milk urea N concentration should be evaluated in association with parity, days in milk, and season (or month). These variables should be considered potential sources of misinterpretation when exploring the relationship between milk urea N and nutritional management or measures of performance.

Bio-economic model to evaluate twinning rate using sexed embryo transfer in dairy herds.

A stochastic bio-economic model has been used to determine the effects of new reproductive technologies over a 15-year period. A strategy of using conventional artificial insemination (AI) or embryo transfer (ET) using two sex-controlled embryos at different conception rates (CRs) and herd sizes resulted in a 24 state model. The genetic means of AI population increased over the years, and the genetic means of milk production for all of the embryo strategies were greater than those of AI. In addition, the genetic means of milk yield using different embryo-based scenarios in the expanding herds were greater than those for the fixed herds. The net profit of using sexed ET in the expanding herds was greater (P < 0.05) than that of fixed size herds. In general, there was a roughly consistent trend in net profit per cow for sexed ET strategies in the expanding herds over the years, but there was an increasing trend in net profit per cow for sexed ET strategies in the fixed herds over the years. Medium to high CRs for ET and the use of sex-controlled embryo systems, especially for induction of twin births to produce dairy replacements, will be critical elements of a system that produces significant numbers of female calves. The greater number of female calves produced in the sex-controlled scenarios allows the farmer to select animals with the best genetic potential as dairy replacement heifers; therefore, the rate of genetic gain increased in the dairy herd. Results of sensitivity analyses showed that a significant decrease in the production costs and increase in the ET performance are essential for embryo-based technologies to be profitable.

Manual removal or spontaneous placental delivery and postcesarean endometritis and bleeding.

OBJECTIVES: To compare the effect of manual removal and spontaneous delivery of placenta on postcesarean bleeding and endometritis. METHODS: In this prospective study 400 pregnant women undergoing elective cesarean delivery were randomly assigned to two groups: spontaneous placental delivery (200 women) and manual placental delivery (200). No antibiotic prophylaxis was administered in either group. The significance of blood loss due to cesarean delivery was defined by a drop in hemoglobin concentration of more than 1 g/dl 24 h after delivery in comparison with preoperative hemoglobin concentration. Endometritis was diagnosed in patients who developed clinical signs of fever and suprapubic tenderness 48 h after delivery. We analyzed the data using a t-test. RESULTS: The overall endometritis rate was 27%, in 40 women in the spontaneous placental delivery group (20%) and 68 women in the manual placental removal group (34%). There was a statistically significant difference between the two groups (P=0.001). Significant blood loss was experienced by 52 women (26%) in the spontaneous placental delivery group vs. 100 women (50%) in the manual placental delivery group. There was a statistically significant difference in blood loss between the two groups (P=0.000; RR=1.92). CONCLUSION: Endometritis and blood loss in cesarean delivery is increased by manual removal of the placenta compared with the spontaneous method of placental removal.

Assessment of fetal weight based on ultrasonic femur length after the second trimester.

OBJECTIVE: The ultrasonic measurement of the fetal femur length is a sensitive and precise variable for estimation of fetal growth and development. The objective of this study is to predict fetal weight in fetuses of more than 24 weeks gestation by ultrasound measurement of the femur length. METHOD: In this study, pregnant mothers were identified by the criteria of normalities, such as: well-known LMP, regular menstrual cycles, no use of OCP for the last 3 months, no use of alcohol or cigarettes, no drug abuse, no history of diabetes or chronic HTN. Multiple gestations, congenital anomalies and still-births were excluded. Birth-weight measurements (adjusted for maternal age, baby's sex, parity and week of gestation) were taken immediately after birth. RESULT: The relation between fetal weight and fetal femur length has been determined by cross-sectional analysis of 900 normal fetuses (> or = 25 weeks gestation) using real time ultrasonography. Mathematical modeling of the data has demonstrated that the femur growth curve is non-linear beyond 24 weeks gestation. With the aid of a scientific calculator the data were analyzed and a simple second-grade equation has been derived: EFW (kg) = 0.042FL(2) (cm)+0.32FL-1.36, S.D. approximately +/-235 g (Honarvar's Formula 2). With the use of this data, the error in estimation of EFW given FL is +/-235 g. CONCLUSION: This simple, new and accurate equation appears to be clinically reliable and easy to use and suggests that previous normal ultrasonic fetal femur length curves for another population may underestimate or overestimate normal fetal weight for the Iranian population. Thus, our formula is an excellent means to estimate true fetal weight.

Assessment of gestational age based on ultrasonic femur length after the first trimester: a simple mathematical correlation between gestational age (GA) and femur length (FL).

OBJECTIVE: The ultrasonic measurement of the fetal femur length is a sensitive and precise variable for estimation of fetal growth and development. The objective of this study was to predict gestational age in fetuses more than 13 weeks of gestation by ultrasound measurement of the femur length. METHOD: In this study, pregnant mothers were identified by the criteria of normalities such as: well-known LMP, regular menstrual cycles, no use of OCP for the last 3 months, no smoking, no history of diabetes, etc. RESULT: The relation between gestational age and fetal femur length has been determined by cross-sectional analysis of 900 normal fetuses (> or = 14 weeks of gestation) using real time ultrasonography. Mathematical modeling of the data has demonstrated that the femur growth curve is non-linear beyond 13 weeks of gestation. With the aid of a scientific calculator the data were analyzed and a simple second grade equation has been derived: GA (weeks) = 0.262(2) FL (cm) + 2 FL + 11.5, S.D. approximately +/- 5 days(Honarvar's Formula 3). With the use of this data, the error in the estimation of GA given as FL is +/-5 days. CONCLUSION: This simple, new and accurate equation appears to be clinically reliable and easy to use and suggests that previous normal ultrasonic fetal femur length curves for another population may under- or overestimate normal fetal age for the Iranian population. Thus, our formula is an excellent means of estimating true gestational age.

A simple estimated fetal weight equation for fetuses between 24 and 34 weeks of gestation.

OBJECTIVE: To develop a mathematical equation that is simple, accurate and easy to use when applied to low-birth weight or preterm fetuses (< 35 weeks) and to assess previous normal ultrasonic fetal weight curves and make a comparison with normal fetal delivery weight curves. METHOD: In a large teaching hospital, 269 pregnant mothers were identified by the criteria of normalities, such as: well known LMP, regular menstrual cycles, no use of OCP for the last 3 months, no smoking and no history of diabetes. Birth-weight measurements (adjusted for maternal age, baby's sex, parity and week of gestation) were taken immediately after birth. RESULTS: Mean gestational age and mean birth' weight + S.D. were 29.5 + 3.02 weeks and 1530.238 237.856 g, respectively. With the aid of a scientific calculator the data were analyzed and a simple regression equation has been derived: EFW (kg) = 0.17 (G.A. - 20), S.D. - 235 g (Honarvar's Formula 1). CONCLUSION: For estimating weights of preterm or low-birth weight fetuses of less than 2500 g, this simple equation appears to be clinically reliable and easy to use and suggests that previous normal ultrasonic fetal weight curves may underestimate or overestimate normal fetal delivery weight between the 24th and 34th week of gestation. Our formula approximates actual birth weight better and recommends Ott's ultrasonic weight curve for Iranian population.