Fraction estimation of small, dense LDL using autocorrelation function of dynamic light scattering

Small, dense low-density lipoprotein (sdLDL) in total LDL is strongly related with the cardiovascular risk level. An optical technique using dynamic light scattering (DLS) measurement is useful for point-of-care testing of sdLDL. However, the sdLDL fraction estimated from the particle size distribution in DLS data is sensitive to noise and artifacts. Therefore, we derived analytical solutions in a closed form to estimate the fraction of scatterers using the autocorrelation function of scattered light from a polydisperse solution. The effect of the undesired large particles can be eliminated by the pre-processing of the autocorrelation function. The proposed technique was verified using latex standard particles and LDL solutions. Results suggest the feasibility of this technique to estimate the sdLDL fraction using optical scattering measurements

Measurement of lipoprotein particle sizes using dynamic light scattering

Background: A simple method for the measurement of LDL particle sizes is needed in clinical laboratories because a predominance of small dense LDL (sd LDL) has been associated with coronary heart disease. We applied dynamic light scattering (DLS) to measure lipoprotein particle sizes, with special reference to sd LDL. Methods: Human serum lipoproteins isolated by a combination of ultracentrifugation and gel chromatography, or by sequential ultracentrifugation, were measured for particle size using DLS. Results: The sizes of polystyrene beads, with diameters of 21 and 28 nm according to the manufacturer, were determined by DLS as 19.3 ± 1.0 nm (mean ± SD, n = 11) and 25.5 ± 1.0 nm, respectively. The coefficients of variation for the 21-nm and 28-nm beads were 5.1% and 3.8% (within-run, n = 11), and 2.9% and 6.2% (between-run, n = 3), respectively. The lipoprotein sizes determined by DLS for lipoprotein fractions isolated by chromatography were consistent with the elution profile. Whole serum, four isolated lipoprotein fractions (CM + VLDL + IDL, large LDL, sd LDL, and HDL) and a non-lipoprotein fraction isolated by sequential ultracentrifugation were determined by DLS to be 13.1 ± 7.5 nm, 37.0 ± 5.2 nm, 21.5 ± 0.8 nm, 20.3 ± 1.1 nm, 8.6 ± 1.5 nm, and 8.8 ± 2.0 nm, respectively. Conclusions: The proposed DLS method can differentiate the sizes of isolated lipoprotein particles, including large LDL and sd LDL, and might be used in clinical laboratories in combination with convenient lipoprotein separation

Standard Identification Certificate for Legal Legislation of a Unique Gene Pool of Thai Domestic Elephants Originating from a Male Elephant Contribution to Breeding

Illegal wildlife trade is a major threat to global biodiversity. Asian elephants (Elephas maximus) are highly valued by various cultures as religious symbols and tourist attractions, which has led to a high demand for captive elephants. Owing to the unviability of captive breeding programs, several captive elephant populations are maintained by illegally obtaining wild Asian elephants. Morbidity and mortality rates among captive populations are high, whereas reproduction is low. In this study, we examined the genetic diversity among elephants using microsatellite genotyping and mitochondrial D-loop sequences of three captive elephant populations. The study results showed very low nucleotide diversity D-loop sequences and high variations in microsatellite genotyping, with an extensive variation of the gene pool estimates from different populations. This suggests that the optimal male selection during breeding could aid in maintaining the genetic diversity among captive populations. Forward genetic simulation revealed a decreasing genetic diversity in the fixed state within 50 generations. However, largely different gene pools can be effectively used to infer original elephant sources; this would facilitate the development of an identification certificate integration with machine learning and image processing to prevent illegal legislation owing to registration fraud between wild and domestic elephants. Implementing the proposed approaches and recommendations would aid in the mitigation of the illegal capture and domestic trade of wild elephants in Thailand and contribute to the success of future conservation plans in the blueprint of sustainable development goals