Population genomic analyses of protected incense trees Aquilaria sinensis reveal the existence of genetically distinct subpopulations

The incense tree Aquilaria sinensis (Thymelaeaceae) can produce agarwood with commercial values and is now under threat from illegal exploitation in Hong Kong, impairing the local population and biodiversity. Together with other species of Aquilaria, it is listed in the CITES Appendix II, which strictly regulates its international trade. To understand the population structure of A. sinensis and to make relevant conservation measures, we have sequenced 346 individuals collected in Hong Kong and southern mainland China. Population genomic analyses including principal component analysis, neighbor-joining tree construction, ADMIXTURE, and hierarchical pairwise-FST analyses suggested that genetically distinct populations are contained in certain areas. Genomic scan analyses further detected single-nucleotide polymorphism (SNP) outliers related to plant defense, including the CYP71BE gene cluster. In addition to the population analyses, we have developed a modified hexadecyltrimethyl-ammonium bromide (CTAB) DNA extraction protocol for obtaining DNA from agarwood samples in this study, and resequencing of DNA extracted from two agarwood samples using this method allows us to successfully map to the sample corresponding localities in the phylogenetic tree. To sum up, this study suggested that there is a genetically distinct subpopulation of incense tree in Hong Kong that would require special conservation measures and established a foundation for future conservation measures

Transgenic Mice Over-Expressing ET-1 in the Endothelial Cells Develop Systemic Hypertension with Altered Vascular Reactivity

Endothelin-1 (ET-1) is a potent vasoconstrictor involved in the regulation of vascular tone and implicated in hypertension. However, the role of small blood vessels endothelial ET-1 in hypertension remains unclear. The present study investigated the effect of chronic over-expression of endothelial ET-1 on arterial blood pressure and vascular reactivity using transgenic mice approach. Transgenic mice (TET-1) with endothelial ET-1 over-expression showed increased in ET-1 level in the endothelial cells of small pulmonary blood vessels. Although TET-1 mice appeared normal, they developed mild hypertension which was normalized by the ETA receptor (BQ123) but not by ETB receptor (BQ788) antagonist. Tail-cuff measurements showed a significant elevation of systolic and mean blood pressure in conscious TET-1 mice. The mice also exhibited left ventricular hypertrophy and left axis deviation in electrocardiogram, suggesting an increased peripheral resistance. The ionic concentrations in the urine and serum were normal in 8-week old TET-1 mice, indicating that the systemic hypertension was independent of renal function, although, higher serum urea levels suggested the occurrence of kidney dysfunction. The vascular reactivity of the aorta and the mesenteric artery was altered in the TET-1 mice indicating that chronic endothelial ET-1 up-regulation leads to vascular tone imbalance in both conduit and resistance arteries. These findings provide evidence for the role of spatial expression of ET-1 in the endothelium contributing to mild hypertension was mediated by ETA receptors. The results also suggest that chronic endothelial ET-1 over-expression affects both cardiac and vascular functions, which, at least in part, causes blood pressure elevation

Use of self monitoring of blood glucose in glycaemic control of non-insulin treated type 2 diabetes mellitus patients

published_or_final_versionNursing StudiesMasterMaster of Nursin

Relationship between perceived physical literacy and physical activity levels among Hong Kong adolescents.

This study explores the relationship between the perceived physical literacy (PL) and physical activity (PA) levels of Hong Kong adolescents by using a cross-sectional study design. A total of 1,945 adolescents aged between 12 and 18, (1,028 male and 917 female) with a mean age of 14.98 (±1.65 years), took part in this study. A Perceived Physical Literacy Instrument (PPLI) and an International Physical Activity Questionnaire for Adolescents (IPAQ-A) were distributed to the participants within the first 15 minutes of PE lessons at their schools. The correlation between perceived PL and PA levels was low but significant (r = 0.227, p < 0.01), as was the correlation between the attributes of PL and PA intensity and the domains of PA (r = 0.067-0.292, p < 0.01). A significant linear equation was computed (F (3, 1941) = 35.679, p < 0.01), with an R2 of 0.052. The metabolic equivalent (MET) minutes representing participants' predicted PA levels were -5490 + 366.1 (sense of self and self-confidence) + 221.866 (self-expression and communication with others) + 287.748 (knowledge and understanding). Looking at individual factors, the correlation between perceived PL and PA levels showed no significant difference across gender (r male = 0.234; r female = 0.198) but showed a significant difference across grade level (r junior = 0.302; r senior = 0.197), school bands (r band 1 = 0.31; r band 2 = 0.263; r band 3 = 0.191) and socio-economic status (SES) (rlow = 0.225; rmedium = 0.35; rhigh = 0.191). The relationship between perceived PL and PA levels was significantly low but was closely related to the recreational PA, including individual factors such as gender, grade levels, school band and SES. Future studies could focus on school-based PA intervention programmes for perceived PL and the relationship between perceived PL and objective PA levels

The effects of a novel pilates exercise prescription method on people with non-specific unilateral musculoskeletal pain: a randomised pilot trial

Background: Pain alters the neuromuscular activation and results in altered movement adaptations. A new exercise prescription method proposes that we can restore the neuromuscular control by rehabilitating the deficient neural drive through Pilates exercises. This is done by identifying the postural control deficits using single-leg tests such as hopping, half squats and heel raises. The aim of this study was to find out if this method of prescribing exercises results in clinically relevant outcomes. Methods: Fifteen patients with chronic non-specific low back pain with unilateral musculoskeletal pain were recruited. Following consent, all patients were randomly assigned either to perform gym or Pilates-based individualised exercises once weekly for six weeks. The primary outcome was to measure the pain intensity using a 0–10 numerical rating scale. The secondary outcome measures were: the global perceived effect scale (GPE; 0–10), the patient-specific functional scale (PSFS; the patient-generated measure of disability) and the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC; the condition-specific measure of disability). Results: There were statistically significant differences noted after intervention within the control group in the numerical rating scale ( P =0.041), GPE ( P =0.024), PSFS ( P =0.039) and within the experimental group in the WOMAC ( P =0.008), GPE ( P =0.007) and PSFS ( P =0.007). However, as there were clinically significant baseline differences, the within-group difference could be due to regression to the mean. There were no statistically significant results between the two groups after intervention. Conclusion: This new prescription method for Pilates-based exercises may improve disability and global perception of recovery. However, the outcomes are not different from a regular gym-based exercise programme

Inhibitory effect of nonsteroidal anti-inflammatory drugs on adenosine transport in vascular smooth muscle cells

It is generally accepted that the clinical efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) arises mainly from the inhibition of cyclooxygenase (COX). However, more evidence has suggested that certain pharmacological actions of NSAIDs may be mediated by COX-independent mechanisms. The present study investigated the effects of NSAIDs on adenosine uptake in human aortic smooth muscle cells (HASMCs). Among the NSAIDs tested (all at 100 µM), aspirin, ibuprofen and naproxen had no effect on [3H]adenosine uptake. Piroxicam inhibited [3H]adenosine uptake by 30%, while etodolac, indomethacin, ketoprofen, mefenamic acid and sulindac inhibited [3H]adenosine by 13–18%. Sulindac sulfide, an active metabolite of sulindac, inhibited [3H]adenosine uptake and [3H]nitrobenzylmercaptopurine ribonucleoside (NBMPR) binding of HASMCs with IC50 values of 40.67 ± 4.82 and 24.19 ± 3.76 μM, respectively. Kinetic studies revealed that sulindac sulfide was a competitive inhibitor of adenosine uptake. Using the nucleoside-transporter-deficient PK15NTD cells that stably express equilibrative nucleoside transport (ENT) 1 and ENT2, it was found that the inhibitory effect of sulindac sulfide on ENT1 was greater than that on ENT2. Sulindac sulfide increased the extracellular adenosine level. In addition, it inhibited the proliferation of HASMCs and this anti-proliferative effect could be abolished by adenosine A2B receptor antagonist. Our results suggest that sulindac sulfide may exert pharmacological effects through the inhibition of adenosine uptake, which modulates the availability of adenosine in the vicinity of adenosine receptors

Relaxation effect of narirutin on rat mesenteric arteries via nitric oxide release and activation of voltage-gated potassium channels

Narirutin is one of the most common flavanones found in citrus fruits. The vascular effects of its analogues naringenin and naringin have been reported but its effects on the cardiovascular system are largely unknown. In this study, relaxation effect of narirutin and its mechanisms of action were investigated by measuring isometric tension in rat mesenteric arteries. Patch-clamping was also used to study the effect of narirutin on potassium channels in vascular smooth muscle cells. Moreover, its effects on phosphorylation of endothelial nitric oxide synthase, cAMP level and phosphodiesterase activity in rat mesenteric arteries were studied by Western blot and biochemical assays. The results showed that pre-incubation of rat mesenteric arteries with narirutin had no influence on acetylcholine-induced endothelial-dependent relaxation. However, narirutin caused a direct concentration-dependent relaxation in rat mesenteric arteries. This relaxation effect was comparable to that of narirutin's structural analogue naringenin. Narirutin-induced relaxation was reduced by the removal of endothelium, NG-nitro-L-arginine methyl ester (a nitric oxide synthase inhibitor), and 4-aminopyridine (a voltage-gated potassium channel blocker). In addition, narirutin increased the phosphorylation of endothelial nitric oxide synthase and increased the voltage-dependent potassium current in mesenteric arterial smooth muscle cells. These effects were abolished by protein kinase A inhibitor. Furthermore, narirutin could increase cAMP level and inhibit phosphodiesterase activity in rat mesenteric arteries. In conclusion, narirutin has vasorelaxing effect and the mechanism involves the inhibition of phosphodiesterase, which increases intracellular cAMP, thereby stimulating the endothelial nitric oxide synthase and activating the voltage-gated potassium channels in vascular smooth muscle cells

Relaxation effect of abacavir on rat basilar arteries

Background: The use of abacavir has been linked with increased cardiovascular risk in patients with human immunodeficiency virus infection; however, the mechanism involved remains unclear. We hypothesize that abacavir may impair endothelial function. In addition, based on the structural similarity between abacavir and adenosine, we propose that abacavir may affect vascular contractility through endogenous adenosine release or adenosine receptors in blood vessels. Methods: The relaxation effect of abacavir on rat basilar arteries was studied using the myograph technique. Cyclic GMP and AMP levels were measured by immunoassay. The effects of abacavir on nucleoside transporters were studied using radiolabeled nucleoside uptake experiments. Ecto-5′ nucleotidase activity was determined by measuring the generation of inorganic phosphate using adenosine monophosphate as the substrate. Results: Abacavir induced the relaxation of rat basilar arteries in a concentration-dependent manner. This relaxation was abolished when endothelium was removed. In addition, the relaxation was diminished by the nitric oxide synthase inhibitor, L-NAME, the guanylyl cyclase inhibitor, ODQ, and the protein kinase G inhibitor, KT5820. Abacavir also increased the cGMP level in rat basilar arteries. Abacavir-induced relaxation was also abolished by adenosine A2 receptor blockers. However, abacavir had no effect on ecto-5’ nucleotidase and nucleoside transporters. Short-term and long-term treatment of abacavir did not affect acetylcholine-induced relaxation in rat basilar arteries. Conclusion: Abacavir induces acute endothelium-dependent relaxation of rat basilar arteries, probably through the activation of adenosine A2 receptors in endothelial cells, which subsequently leads to the release of nitric oxide, resulting in activation of the cyclic guanosine monophosphate/protein kinase G-dependent pathway in vascular smooth muscle cells. It is speculated that abacavir-induced cardiovascular risk may not be related to endothelial dysfunction as abacavir does not impair relaxation of blood vessels. The most likely explanation of increased cardiovascular risk may be increased platelet aggregation as suggested by other studies

Relaxation effect of abacavir on rat basilar arteries.

BACKGROUND:The use of abacavir has been linked with increased cardiovascular risk in patients with human immunodeficiency virus infection; however, the mechanism involved remains unclear. We hypothesize that abacavir may impair endothelial function. In addition, based on the structural similarity between abacavir and adenosine, we propose that abacavir may affect vascular contractility through endogenous adenosine release or adenosine receptors in blood vessels. METHODS:The relaxation effect of abacavir on rat basilar arteries was studied using the myograph technique. Cyclic GMP and AMP levels were measured by immunoassay. The effects of abacavir on nucleoside transporters were studied using radiolabeled nucleoside uptake experiments. Ecto-5' nucleotidase activity was determined by measuring the generation of inorganic phosphate using adenosine monophosphate as the substrate. RESULTS:Abacavir induced the relaxation of rat basilar arteries in a concentration-dependent manner. This relaxation was abolished when endothelium was removed. In addition, the relaxation was diminished by the nitric oxide synthase inhibitor, L-NAME, the guanylyl cyclase inhibitor, ODQ, and the protein kinase G inhibitor, KT5820. Abacavir also increased the cGMP level in rat basilar arteries. Abacavir-induced relaxation was also abolished by adenosine A2 receptor blockers. However, abacavir had no effect on ecto-5' nucleotidase and nucleoside transporters. Short-term and long-term treatment of abacavir did not affect acetylcholine-induced relaxation in rat basilar arteries. CONCLUSION:Abacavir induces acute endothelium-dependent relaxation of rat basilar arteries, probably through the activation of adenosine A2 receptors in endothelial cells, which subsequently leads to the release of nitric oxide, resulting in activation of the cyclic guanosine monophosphate/protein kinase G-dependent pathway in vascular smooth muscle cells. It is speculated that abacavir-induced cardiovascular risk may not be related to endothelial dysfunction as abacavir does not impair relaxation of blood vessels. The most likely explanation of increased cardiovascular risk may be increased platelet aggregation as suggested by other studies