Radiological Density, Atomic Numbers, and Stone Fragmentation of Bego Stones Used for Research in Endourology: Comparison to Real Urinary Stones.

Objective: The aim of the study was to characterize artificial stones used for research in endourology in terms of radiological properties and hardness, based on stone fragmentation, and to compare them with real stones. Materials and Methods: We built artificial stones using BegoStone Plus™ powder (BEGO, Lincoln, RI), with powder (g)-water (mL) ratios ranging from 15:03 to 15:12. The CT Gemstone Spectral Imaging Software® (GE Medical Systems, LLC, Waukesha, WI) was used to evaluate the radiological density in HU and spectral properties. Stone fragmentation was assessed in an in vitro experimental setting. These properties of artificial stones were compared with real urinary calculi. Results: Regarding radiological density in terms of HUs, 15:03 artificial calculi showed similar results when compared with real stones comprising calcium oxalate and calcium phosphate. The 15:03 and 15:04 artificial stones showed similar spectral property results to calcium pyrophosphate stones. The 15:11 artificial stones showed similar stone fragmentation results to real stones comprising uric acid, and 15:03 artificial calculi showed similar results to apatite and cystine stones. Conclusions: Artificial stones are useful for research in endourology. Stones with a powder (g)-water (mL) ratio of 15:03 proved to mimic real hard stones in terms of HUs, atomic number, and stone fragmentation in our study and could be used as artificial hard stones, and 15:11 stones showed similar stone fragmentation to uric acid stones. Our study might suggest that standard Bego stones are useful to investigate different areas in endourology, but not radiological properties because radiological homogeneity is not ensured unless more sophisticated mixing methods are used.

Relationship among age, insulin resistance, and blood pressure.

The effect of age to modify the relationship between insulin resistance and hypertension is unclear. In this retrospective, cross-sectional study, median age was used to create two age groups (<52 vs. ≥52 years), and comparisons were made of metabolic characteristics, including steady-state plasma glucose (SSPG) concentrations measured during the insulin suppression test to quantify insulin resistance. Individuals were stratified into SSPG tertiles and categorized as having normal blood pressure (BP), prehypertension, or hypertension. SSPG concentrations were similar in the two age groups (161 vs. 164 mg/dL). In the most insulin-resistant tertile, distribution of normal BP, prehypertension, and hypertension was equal in those aged <52 years, whereas in those aged ≥52 years, prevalence of hypertension was increased approximately fivefold compared with those with normal BP. Multivariate regression analysis demonstrated significant interaction between age and SSPG in predicting systolic BP (P = .023). In stratified analysis, SSPG, but not age, was an independent predictor of systolic BP and diastolic BP in ≥52 years group, whereas the reverse was true in the younger group. The adverse impact of insulin resistance on BP was accentuated in older individuals and may have a greater impact than further aging.

Statistical review of US macronutrient consumption data, 1965-2011: Americans have been following dietary guidelines, coincident with the rise in obesity.

BACKGROUND: For almost 50 y, the US National Health and Nutrition Examination Survey (NHANES) has measured the caloric consumption, and body heights and weights of Americans. The aim of this study was to determine, based on that data, how macronutrient consumption patterns and the weight and body mass index in the US adult population have evolved since the 1960s. METHODS: We conducted the first comprehensive analysis of the NHANES data, documenting how macronutrient consumption patterns and the weight and body mass index in the US adult population have evolved since the 1960s. RESULTS: Americans in general have been following the nutrition advice that the American Heart Association and the US Departments of Agriculture and Health and Human Services have been issuing for more than 40 y: Consumption of fats has dropped from 45% to 34% with a corresponding increase in carbohydrate consumption from 39% to 51% of total caloric intake. In addition, from 1971 to 2011, average weight and body mass index have increased dramatically, with the percentage of overweight or obese Americans increasing from 42% in 1971 to 66% in 2011. CONCLUSIONS: Since 1971, the shift in macronutrient share from fat to carbohydrate is primarily due to an increase in absolute consumption of carbohydrate as opposed to a change in total fat consumption. General adherence to recommendations to reduce fat consumption has coincided with a substantial increase in obesity.