The Effects of Angiotensin I-Converting Enzyme (ACE) I/D and Alpha-Actinin-3 (ACTN3) R/X Gene Polymorphisms on Human Physical Performance and Health within Malaysian Population

A disparity population data set in the current literature with limited reports among Asian samples, coupled with the inconsistent findings among different ethnic groups, and lack of information for the involvement of angiotensin I-converting enzyme (ACE) I/D and alpha-actinin-3 (ACTN3) R/X gene polymorphisms in training adaptation have limited the ability of researchers to draw meaningful conclusions pertaining to the effects of these polymorphisms on human physical performance and health. Therefore, this doctoral research implemented three series of studies to examine the effects of ACE I/D and ACTN3 R/X gene polymorphisms on human physical performance and health within the Malaysian population. In the first study, DNA samples were retrieved via buccal cell from 180 Asians from Malaysia (70 males, 110 females) aged 20.4 ± 1.6 years, and 180 Caucasians from Australia (62 males, 118 females) aged 23.3 ± 3.6 years. In the second study, DNA samples were retrieved from 180 well-trained Malaysian athletes (148 males, 32 females) aged 20.5 ± 1.9 years, 180 Malaysian sedentary controls, and 33 intermittent Australian athletes (all males) aged 20.7 ± 4.0 years. Endurance and muscular performances of Malaysian athletes were evaluated with 20 meters Yo-Yo intermittent recovery level 2 and maximal voluntary contraction tests, respectively. In the third study, thirty normotensive, untrained males (ACE genotype: II = 10, ID = 10, and DD = 10), undergone isometric handgrip training (four sets of 2 minutes isometric contractions at 30% of maximal voluntary contraction, with 1 minute resting interval) 3 days per week for 8 weeks. The result from the first study indicated that the distribution of ACE I/D gene polymorphism varied among different ethnic groups, but not to ACTN3 R/X gene polymorphism. The findings obtained from the second study demonstrated that: a) The effects of these polymorphisms on endurance and strength/power performances did not vary by ethnicity, b) The ACE D allele and ACTN3 R allele conferred an advantage in activities that require strength/power, and c) The ACE I allele and ACTN3 X allele did not influence endurance performance. Finding from the final study demonstrated that ACE I/D gene polymorphism had a positive influence in cardiovascular and muscular adaptations following isometric handgrip training among normotensive men. Overall, this research reaffirms the notion that strength/power performance is influenced by the ACE D allele and ACTN3 R allele. In addition, this research concludes that the ACE I/D gene polymorphism modulates response to isometric handgrip training in normotensive men

Alpha-Actinin-3 (ACTN3) R/X Gene Polymorphism and Physical Performance of Multi-Ethnic Malaysian Population

A disparity population data set in the current literature with limited reports among Asian samples and the inconsistent findings among different ethnic groups warrant further investigation on the association between alpha-actinin-3 (ACTN3) R/X gene polymorphism and human physical performance in Asian population. This study was designed to examine the association between ACTN3 R/X gene polymorphism and physical performance of multi-ethnic Malaysian population. One hundred eighty well-trained athletes (34 endurance, 41 strength, and 105 intermittent) and 180 controls were drawn from four ethnic groups in Malaysia (Malay, Chinese, Indian, and Other Bumiputra). A sample of deoxyribonucleic acid (DNA) was retrieved from a buccal swab from each participant and the ACTN3 R/X genotype was identified through polymerase chain reaction and restriction fragment length polymorphism analysis. The strength and endurance performances of the athletes were evaluated with maximal voluntary contraction and Yo-Yo intermittent recovery level 2 tests, respectively. The independent t-test, chi-square, multivariate, and one-way analysis of variance were used for data analysis. ACTN3 R/X alleles (p = 0.672) and genotype (p = 0.355) frequencies did not vary much between the multi-ethnic groups of Malaysian athletes. These small variations did not have any influence on handgrip strength (p = 0.334), leg strength (p = 0.256), and Yo-Yo intermittent recovery level 2 performance (p = 0.425) between these ethnic groups. The RR and XX genotypes were more frequent among strength and intermittent athletes, respectively. Athletes with the RR genotype had greater handgrip than those with the RX genotype (p = 0.031), but not different from athletes with the XX genotype (p = 0.228)

The Efficacy of Ingesting Water on Thermoregulatory Responses and Running Performance in a Warm-Humid Condition

The understanding that fluid ingestion attenuates thermoregulatory and circulatory stress during exercise in the heat was based on studies conducted in relatively dry (∼50% RH) environments. It remains undetermined whether similar effects occur during exercise in a warm and more humid environment, where evaporative capacity is reduced. Nine well-trained, unacclimatised male runners were randomly assigned to perform four experimental trials where they ran for 60 min at an intensity of 70% VO2max followed by an incremental exercise test until volitional exhaustion. The four trials consisted of non-fluid ingestion (NF) and fluid ingestion (FI) in a warm-dry (WD) and warm-humid condition (WH). Time to exhaustion (TTE), body temperature (Tb), whole body sweat rate, partitional calorimetry measures, heart rate and plasma volume were recorded during exercise. There was no significant difference in Tb following 60 min of exercise in FI and NF trial within both WD (37.3°C ± 0.4 vs. 37.4°C ± 0.3; p > 0.05) and WH conditions (38.0°C ± 0.4 vs. 38.1°C ± 0.4; p > 0.05). The TTE was similar between FI and NF trials in both WH and WD, whereas exercise capacity was significantly shorter in WH than WD (9.1 ± 2.8 min vs. 12.7 ± 2.4 min, respectively; p = 0.01). Fluid ingestion failed to provide any ergogenic benefit in attenuating thermoregulatory and circulatory stress during exercise in the WH and WD conditions. Consequently, exercise performance was not enhanced with fluid ingestion in the warm-humid condition, although the humid environment detrimentally affected exercise endurance

Scaffolds for cartilage regeneration: to use or not to use?

Joint cartilage has been a significant focus on the field of tissue engineering and regenerative medicine (TERM) since its inception in the 1980s. Represented by only one cell type, cartilage has been a simple tissue that is thought to be straightforward to deal with. After three decades, engineering cartilage has proven to be anything but easy. With the demographic shift in the distribution of world population towards ageing, it is expected that there is a growing need for more effective options for joint restoration and repair. Despite the increasing understanding of the factors governing cartilage development, there is still a lot to do to bridge the gap from bench to bedside. Dedicated methods to regenerate reliable articular cartilage that would be equivalent to the original tissue are still lacking. The use of cells, scaffolds and signalling factors has always been central to the TERM. However, without denying the importance of cells and signalling factors, the question posed in this chapter is whether the answer would come from the methods to use or not to use scaffold for cartilage TERM. This paper presents some efforts in TERM area and proposes a solution that will transpire from the ongoing attempts to understand certain aspects of cartilage development, degeneration and regeneration. While an ideal formulation for cartilage regeneration has yet to be resolved, it is felt that scaffold is still needed for cartilage TERM for years to come

The effects of two relaxation techniques on psychomotor, psychological and physiological variables following repeated submaximal intensity exercise among school athletes

The present study was undertaken with an objective to investigate the effects of two relaxation techniques on selected psychomotor (choice reaction time), psychological (rating of perceived exertion (RPE) and physiological (heart rate, oxygen consumption (V02)) variables following repeated sub-maximal intensity exercise. Twenty four physically active young males with the mean age of 14.1 ± 1.3 years, height 157.3 ± 6.1 em, weight 45.6 ± 7.2 kg, V02max 45.7 ± 4.2 ml.kg-1.min-1 and HRmax 205.9 ± 1.3 participated in this study. They were randomly divided into one of the three groups: Autogenic relaxation {AGR), progressive muscle rela'l(ation {PMR.) and a control group. AGR and PMR group were tested in two experimental sessions; prior to and after relaxation training. However, the control group performed the same experimental procedures except the relaxation training. Each experimental session consists of four trials, where they had to cycle at 60% V02max for I 0 minutes followed by 90% V02max for 2 minutes in each trial. Then, it is followed by 3-minute resting interval where choice reaction time (CRT) was tested. Furthermore, RPE, heart rate, and V02 were recorded at the end of each trial. The results of two-way repeated measure ANOV A revealed a non significant (p > .05) interaction between the groups across the experimental trials in all of the selected parameters. However, results of the main effect revealed a significant (p < .05) difference for experimental sessions for RPE and V02. Pair wise comparison analysis revealed a significant (p < .05) reduction in RPE value from prexi to post-intervention sessions for PMR group and a significant (p < .05) decrease in the value ofV02 from pre- to post-intervention exercise for AGR and control groups. Thus, this study concluded that both relaxation techniques did not differ in terms of choice reaction time, RPE, V02 and heart rate following repeated sub-maximal intensity exercise. However, when analysed separately, PMR appears to reduce RPE while AGR appears to reduce vo2

The role of trustee in Malaysia: comparative study between common law and Islamic law / Amirah Mohd Alias ...[et al.]

This research elucidates the concept of trustee comprehensively in both common law and Islamic law which comprises the appointment and removal of the trustee, delegation and remuneration of trustee, as well as the duty of the trustee towards the beneficiary. Furthermore, this research deals with the constitutional conflict with regards to the jurisdictional issues between common law and Islamic law in matters pertaining to trust and trustee in Malaysia. The legal position on Muslims trust and trustee in Malaysia has became a matter of controversy following the civil judicial scrutiny in matter concerning Islamic trust, inheritance, gift, and wakaf'm spite of the express provision declaring that those matters fall within the state and Syariah court jurisdiction. Thus, this research is designed to ascertain the inconsistency of the existing Trustee Act 1949 with Hukum Syara by comparing and contrasting the role of trustee under common law and Islamic law in Malaysia along with emphasizing the lacunae and the ambiguity of the statutory provisions that may adversely affect the process of Muslims trusteeship and the purpose of Muslims trust with a view to recommend possible solutions to the current legal conflict in Malaysia