Fast Principal-Component Analysis Reveals Convergent Evolution of ADH1B in Europe and East Asia

Searching for genetic variants with unusual differentiation between subpopulations is an established approach for identifying signals of natural selection. However, existing methods generally require discrete subpopulations. We introduce a method that infers selection using principal components (PCs) by identifying variants whose differentiation along top PCs is significantly greater than the null distribution of genetic drift. To enable the application of this method to large datasets, we developed the FastPCA software, which employs recent advances in random matrix theory to accurately approximate top PCs while reducing time and memory cost from quadratic to linear in the number of individuals, a computational improvement of many orders of magnitude. We apply FastPCA to a cohort of 54,734 European Americans, identifying 5 distinct subpopulations spanning the top 4 PCs. Using the PC-based test for natural selection, we replicate previously known selected loci and identify three new genome-wide significant signals of selection, including selection in Europeans at ADH1B. The coding variant rs1229984^∗T has previously been associated to a decreased risk of alcoholism and shown to be under selection in East Asians; we show that it is a rare example of independent evolution on two continents. We also detect selection signals at IGFBP3 and IGH, which have also previously been associated to human disease.     

Temperature over tumors in hairless mice

The question of whether tumors are warmer or colder than surrounding tissue is considered in these experiments which use a highly suitable animal model, the hairless mouse. Temperatures of skin over induced growing subdermal tumors in these mice were monitored by AGA 680 Color Thermovision. The skin over the tumors does not cool over time but on the contrary becomes warmer. This is probably due to an increase in vascularization rather than increased metabolic rate.     

ON THE SPECIFICITY OF TRYPSIN (EC 3.4.4.4) OF NERVE ENDING PARTICLES TO INHIBIT NOREPINEPHRINE TRANSPORT1,2

The Na⁺ and energy dependent uptake of norepinephrine into cortical rat brain homogenates or purified nerve ending particles (NEP) is reduced by prior trypsin treatment. In contrast, the uptake of dopamine, serotonin, choline and γ-aminobutyric acid is markedly less sensitive to the effect of trypsin. Kinetic analyses indicate that the trypsin-induced decrease of norepinephrine uptake is non-competitive. In the dose range studied, trypsin did not appreciably alter the protein content or morphology of NEP. However, in a dose related fashion, trypsin decreased the glycoprotein content of NEP measured as the loss of protein bound N-acetylneuraminic acid.     

Genetic variation of pancreatic esterase isozyme in Japanese quail

A genetic variation was found in pancreatic esterases of Japanese quail which appeared to be arylesterase. It was found on the cathode side in the agar gel electrophoresis. Three phenotypes, A, B and AB, were observed. These phenotypes were shown to be controlled by one autosomal locus, designated as Es-4 , with co-dominant alleles Es-4^A and Es-4^B.
Es-4 esterase isozymes were detected in all the individuals from about 4 days of age, but the activity was very weak. However, it gradually increased to reach a level almost the same as that of a mature quail from about 15 days of age.     

Long-Term Prognosis of Acute Myocardial Infarction Associated With Metabolic Health and Obesity Status

ObjectiveEmerging evidence supports the favorable cardiovascular health in nonobese subjects with healthy metabolism. However, little is known regarding the prognosis across the range of metabolic phenotypes once cardiovascular disease is established. We examined the prognosis of patients with acute myocardial infarction (AMI) stratified according to metabolic health and obesity status.MethodsThis is a retrospective study on consecutive patients with AMI admitted to a tertiary hospital between 2014 and 2021. Patients were allocated into the following 4 groups based on metabolic and obesity profile: (1) metabolically healthy obese (MHO), (2) metabolically healthy nonobese (MHNO), (3) metabolically unhealthy obese (MUO), and (4) metabolically unhealthy nonobese (MUNO). Metabolic health was defined in accordance to the Biobank Standardisation and Harmonisation for Research Excellence in the European Union Healthy Obese Project. The primary outcome was all-cause mortality. The Cox regression analysis examined the independent association between mortality and metabolic phenotypes, adjusting for age, sex, AMI type, chronic kidney disease, smoking status, and left ventricular ejection fraction.ResultsOf 9958 patients, the majority (68.5%) were MUNO, followed by MUO (25.1%), MHNO (5.6%), and MHO (0.8%). MHO had the lowest mortality (7.4%), followed by MHNO (9.7%), MUO (19.2%), and MUNO (22.6%) (P < .001). Compared with MHNO, MUO (hazard ratio [HR], 1.737; 95% confidence interval [CI], 1.282-2.355; P < .001) and MUNO (HR, 1.482; 95% CI, 1.108-1.981; P = .008) had a significantly higher mortality risk but not MHO (HR, 1.390; 95% CI, 0.594-3.251; P = .447), after adjusting for confounders. The Kaplan-Meier curves showed favorable survival in the metabolically healthy and obesity groups, with the highest overall survival in the MHO, followed by MHNO, MUO, and MUNO (P < .001).ConclusionMetabolically healthy and obese patients with AMI have favorable prognosis compared with metabolically unhealthy and nonobese patients. It is equally important to prioritize intensive metabolic risk factor management to weight reduction in the early phase after AMI.     

Molecular biology-based methods for quantification of bacteria in mixed culture: perspectives and limitations

Species-specific enumeration of mixed community is invaluable as it facilitates a better understanding of the significance of the individual strains, their interactions, and the underlying mechanisms of community dynamics. Mixed microbial community has been characterized by microbiological, biochemical, or molecular biology-based methods. While microbiological and biochemical techniques do not provide adequate quantitative information of the members of the consortia and require additional techniques for a more comprehensive analysis, molecular biology-based methods analyze the microbial consortium based on specific DNA sequences and do not require isolation and culturing of bacteria for quantitative analysis. These methods outshine conventional culture-based techniques in terms of better sensitivity, reproducibility, and reliability. Quantitative molecular biology methods have been classified as PCR-based and probe hybridization methods. The PCR-based methods includes quantitative real-time PCR and terminal restriction fragment length polymorphism, while fluorescent in situ hybridization and DNA microarrays fall under probe hybridization methods. The workflow, the quantification methods, and their potential applications are discussed in this review by highlighting their advantages and possible limitations.