Machine learning guided aptamer refinement and discovery.

Aptamers are single-stranded nucleic acid ligands that bind to target molecules with high affinity and specificity. They are typically discovered by searching large libraries for sequences with desirable binding properties. These libraries, however, are practically constrained to a fraction of the theoretical sequence space. Machine learning provides an opportunity to intelligently navigate this space to identify high-performing aptamers. Here, we propose an approach that employs particle display (PD) to partition a library of aptamers by affinity, and uses such data to train machine learning models to predict affinity in silico. Our model predicted high-affinity DNA aptamers from experimental candidates at a rate 11-fold higher than random perturbation and generated novel, high-affinity aptamers at a greater rate than observed by PD alone. Our approach also facilitated the design of truncated aptamers 70% shorter and with higher binding affinity (1.5 nM) than the best experimental candidate. This work demonstrates how combining machine learning and physical approaches can be used to expedite the discovery of better diagnostic and therapeutic agents.

Effects of winter skiing on stress, heart rate, apprehension, and enjoyment in collegiate students: a single randomized controlled trial.

This study investigated the effect of winter skiing on stress levels in collegiate students and also observed psychological factors related to heart rate, apprehension, and enjoyment. Two hundred thirty-eight male students were randomly classified into the control group (n=117) or the ski group (n=121). The control group received lectures on skiing; however, the ski group received practical ski training. Psychological measures included stress, apprehension, and enjoyment; physical measures included heart rate at pre- and postday. There were significant correlations between stress and apprehension (r=0.366) and stress and enjoyment (r=-0.441). Specifically, apprehension negatively correlated with enjoyment (r=-0.599). Between both groups, a significant interaction effect was found among stress, apprehension, and enjoyment. Moreover, compared with the control group, the ski group's stress and apprehension were significantly reduced, whereas the enjoyment was significantly enhanced. This study suggests that winter skiing is a suitable sport for reducing stress and providing a high level of enjoyment for collegiate students.

Analysis of ipsilateral and bilateral ratios in male amateur golfers.

The number of injuries that force golfers to quit is also increasing. In particular, the upper body injuries are concerns for amateur golfers. This study was conducted not only to investigate muscular balance, such as ipsilateral and bilateral ratios of the upper body, but to also evaluate the possible problems of muscular joints in amateur golfers. Male golfers (n=10) and a healthy control group (n=10) were recruited for the assessment of muscular function in the upper body, which was measured by an isokinetic dynamometer at 60°/sec. The tested parts were trunk, wrist, forearm, elbow, and shoulder joints. Mann-Whitney U-test was used to evaluate the significance of the differences between groups. The ipsilateral ratios of peak torque or work per repetition (WR) of trunk flexor and extensor in the golfers were not significantly different compared to those of the control group. These results were similar to the shoulder horizontal abductor and adductor. However, there were significant differences in the ipsilateral and bilateral ratios of the wrist, forearm, and elbow joints. Especially, the WR of the wrist flexor, forearm pronator, and elbow flexor on the left side of amateur golfers showed imbalances in bilateral ratios. Moreover, the WR of the wrist and elbow flexors on the left side of amateur golfers were lower than those of the wrist and elbow extensors. Therefore, amateur golfers should strive to prevent injuries of the wrist, forearm, and elbow joints and to reinforce the endurance on those parts of the left side.

Frequency-effect of playing screen golf on body composition and golf performance in middle-aged men.

There are many studies showing that physical training improves body composition including bone mineral density (BMD) in almost all subjects. However, the frequency-dependent effect of playing golf on body composition is still not clearly comprehended. Moreover, the effect of screen golf in relations with exercise-frequency on body composition and golf performance has not been documented. Forty year old men participated and were classified into 4 groups: Control group (n= 10), BMD1 group (n= 10) played screen golf less than 1 day per a week, BMD2-3 group (n= 10) played screen golf 2-3 days per a week, and BMD5 group (n= 10) played screen golf 5 days per week. Dual-energy X-ray absorptiometry (DXA) was performed on 30 male recreational golfers and 10 sedentary individuals. The data gained through DXA were fat mass, lean mass, regional (head, rib, arm, leg, pelvis, spine and trunk) BMD level, and total BMD level summed by regional scores. The club speeds were measured using the Golfzon Vision machine and the handicap points were measured using a simple questionnaire. The present results suggest that the long-frequency of playing screen golf does not improve bone mineral density, lean mass, and handicap point yet improves fat mass and club speed in the middle-aged men.

Signal detection of methylphenidate by comparing a spontaneous reporting database with a claims database.

Data mining is critical for signal detection in pharmacovigilance systems. In this study, we compared signals between spontaneous reporting data and health insurance claims data for a socially issued drug, methylphenidate. We implemented data-mining tools for signal detection in both databases: Reporting Odds Ratios (ROR), Proportional Reporting Ratios (PRR), Chi-squared test, and Information Component (IC), in addition to a Relative Risk (RR) tool in the claims database. The claims database generated 15, 15, 36, 1, and 1 adverse drug reactions (ADRs) by ROR, PRR, chi-square, IC, and RR, respectively. The World Health Organization (WHO) spontaneous database generated 91, 91, 137, and 96 ADRs by ROR, PRR, chi-square, and IC, respectively. We found seven potential matching associations from the claims and WHO databases, but only one of them was present in the Korean spontaneous reporting database. In Korea, spontaneous reporting is still underreported and there is a small amount of data for Koreans. Signal comparison between the claims and WHO databases can provide additional regulatory insight.

Assessment of heavy metal exposure via the intake of oriental medicines in Korea.

Oriental medical herbs are mainly natural products that are generated by simple processes, and therefore there is the possibility of contamination with various pollutants, including heavy metals. Heavy metals produce adverse effects in humans, and the toxicities of lead (Pb) and cadmium (Cd) are well established. This study evaluated the effects of exposure to Pb and Cd via the intake of the frequent prescriptions of oriental medicines, and assessed the risk to the Korean population based on domestic data. The average daily exposures to Pb and Cd were estimated. This is the first study to evaluate exposure and risk of heavy metal intoxication through intake of oriental medicines in Korea. Despite the uncertainties and limits of the data, these results simulate realistic exposure levels.

Prevalence of bone mineral density loss in Korean patients with schizophrenia: a cross-sectional study.

OBJECTIVE: This study investigates bone mineral density (BMD) and the association between BMD and hormonal changes in Korean patients with schizophrenia. METHOD: This cross-sectional study was conducted from January 2005 to June 2005; 195 inpatients with schizophrenia (DSM-IV) were screened. Among them, 51 patients aged 18 to 45 years who had taken haloperidol monotherapy for at least 2 years participated in this study. The control group consisted of normal healthy volunteers who were of similar ages (N = 57). Bone mineral density was determined by a GE Lunar 4500 scanner. Hormone levels were measured by using commercial kits. The Student t test, the Pearson chi2 test, the Wilcoxon rank sum test, and logistic regression analysis were used for data analysis. RESULTS: Female patients, but not male patients, showed significantly lower BMD than the normal controls as seen in all bone regions studied. Among 18 female patients with BMD loss, 17 patients showed hyperprolactinemia, and 7 showed combined hypoestrogenemia. Prolactin levels were significantly higher in the female patients with BMD loss compared to those with normal bone density; however, other hormone levels were not different between the 2 groups. There was no significant difference in hormonal levels between bone loss and normal bone density groups. CONCLUSIONS: Bone mineral density loss in patients with schizophrenia tended to differ by gender. Decreased BMD compared to normal controls was seen in female patients; however, this was not observed in men.