Amelioration of soils contaminated with radionuclides:Exploiting biodiversity to minimise or maximise soilto plant transfer

Objective: Computed Tomography (CT) is the leading contributor to medical exposure to ionizing radiation. Although the use of CT brain scans for patients with head injuries and convulsions has shown a tremendous growth, it has raised substantial concerns in the general public because of the risk of radiation-induced cataracts: the current available strategies to reduce the radiation dose to the eye lens region are limited. Therefore, the present research project was initiated with the aim of evaluating the potential benefit of the combined use of bolus and a bismuth shield on reducing the radiation dose to the eye lens region during CT brain examination.Materials and methods: We conducted a series of phantom studies to measure the entrance surface dose (ESD) that is delivered to the eye lens region during CT brain examination under the effect of different scanning and shielding setups.Results: Our results indicated, during CT brain examination: (1) a drastic reduction of 92.5% in the ESD to the eye lens region was found when the CT gantry was tilted from 0 degrees (overall ESD = 30.7 mGy) to 30 degrees cranially (overall ESD = 2.4 mGy), and (2) when the CT gantry was positioned at 0 degrees (the common practice in the clinical setting), the setups with the application of a) a bismuth shield, b) a bismuth shield with a face shield (air gap), c) a bismuth shield with bolus, and d) a bismuth shield with bolus and an air gap can result in an acceptable level of image quality with a smaller overall ESD delivered to the eye lens region (overall ESD = 23.2 mGy, 24 mGy, 21 mGy and 19.9 mGy, respectively) than the setup without the bismuth shield applied (overall ESD = 30.7 mGy).Conclusion: When the primary beam scanning through the eye lens region is unavoidable during CT brain examination, the combined use of a bismuth shield with bolus and a face shield is an easy-to-use and inexpensive shielding setup to reduce the radiation dose delivered to the eye lens region while maintaining the correct CT number and a low degree of image noise in the resultant image.Department of Health Technology and Informatic

Reliability and validity of alternate step test times in subjects with chronic stroke

OBJECTIVE: (i) To investigate the intra-rater, inter-rater and test-retest reliability and minimal detectable change of the Alternate Step Test (AST) when assessing people with chronic stroke. (ii) To quantify the correlation between AST times and stroke-specific impairments. DESIGN: Cross-sectional study. SETTING: University-based rehabilitation centre. PARTICIPANTS: A convenience sample of 86 participants: 45 with chronic stroke, and 41 healthy elderly subjects. METHODS: The AST was administered along with the Fugl-Meyer Lower Extremity Assessment (FMA-LE), the Five Times Sit-To-Stand Test (FTSTS), limits of stability (LOS) measurements, Berg Balance Scale (BBS) scores, Chinese-translated Activities-specific Balance Confidence Scale (ABC-C) ratings, and the Timed “Up and Go” test (TUG). RESULTS: Excellent intra-rater, inter-rater and test-retest reliability were found, with a minimal detectable change of 3.26 s. AST times were significantly associated with FMA-LE assessment, FTSTS times, LOS in the forward and backward directions and to the affected side, BBS ratings and TUG times. CONCLUSION: AST time is a reliable assessment tool that correlates with different stroke-specific impairments in people with chronic stroke.published_or_final_versio

Mammographic breast density in Chinese women : spatial distribution and autocorrelation patterns

2015-2016 > Academic research: refereed > Publication in refereed journal201810_a bcmaVersion of RecordPublishe

Growth factors in continuous ambulatory peritoneal dialysis effluent: their relation with peritoneal transport of small solutes

Recent studies reveal conflicting results on the change of solute transfer with time on continuous ambulatory peritoneal dialysis (CAPD) and recurrent peritonitis. Herein, we performed a cross-sectional study of 76 patients on CAPD to examine their peritoneal permeability by measuring the dialysate to serum ratio of creatinine (D/P) and the mass transfer area coefficients of creatinine (MTACCr) or glucose (MTACGlu). Transforming growth factor-β1 (TGF-β1), platelet-derived growth factor (PDGF), and epidermal growth factor (EGF) were measured in the dialysate by ELISA. TGF-β1 mRNA in peritoneal macrophages were determined by a quantitative polymerase chain reaction. We failed to observe any correlation between the duration on dialysis and the peritoneal permeability in those patients with no previous peritonitis. Frequency of peritonitis episode did not affect the MTACCr, MTACGlu, or D/P. The MTACCr correlated well with MTACGlu (r = 0.78, p = 0.001) and with D/P (r = 0.98, p < 0.0001). No inverse correlation was demonstrated between dialysate PDGF or EGF and the peritoneal permeability. A positive correlation was demonstrated between the dialysate TGF-β1 and MTACCr, MTACGlu or D/P (r = 0.64, 0.54, and 0.64 respectively, p < 0.001). The dialysate TGF-β1 levels in patients with low D/P (≤ 0.5) were only half of that in patients with normal or high DIP (p = 0.0002). The dialysate levels of TGF-β1 did not correlate with PDGF or EGF. These findings raise the possibility that, other than diffusion across the peritoneal membrane from circulation, there could also be an intrinsic production of TGF-β1 by peritoneal cells in these CAPD patients. Our findings raise the speculation that TGF-β1 in dialysate from stable CAPD patients may exert an inhibitory action to fibroblast. Such action of TGF-β1 could reduce the risk of peritoneal sclerosis and hence, maintains a satisfactory peritoneal permeability to small solutes.link_to_subscribed_fulltex

Development of kinematic graphs of median nerve during active finger motion : implications of smartphone use

2016-2017 > Academic research: refereed > Publication in refereed journal201804_a bcmaVersion of RecordPublishe

Increased production of hyaluronan by peritoneal cells and its significance in patients on CAPD

Hyaluronan (HA) is a polysaccharide that forms a critical component of extracellular matrices. HA is present in high concentrations in tissues undergoing remodeling and morphogenesis, and it appears to have an important role in the early stages of wound healing. Here, we studied the level of HA in the peritoneal dialysate effluent (PDE) from 116 stable continuous ambulatory peritoneal dialysis (CAPD) patients. Longitudinal studies over a period of 6 weeks were performed in seven of these patients who developed peritonitis. The median HA level in PDE from these patients was 154.6 μg/L (range, 29.7 to 820.2 μg/L). Dialysate level of HA increased with age of the patients, but no such correlation was shown between HA level in PDE and duration of CAPD treatment or previous episodes of peritonitis. Patients with high or average peritoneal membrane transport of small solutes had a higher HA level in the PDE than those with a low peritoneal membrane transport (P = 0.046). A significant correlation was observed between PDE level of HA and interleukin-1β (IL-1β) or IL-6. The plasma level of HA in these patients was significantly greater than that of healthy controls (P < 0.0001), yet the plasma concentration of HA was only 85% that of the PDE concentration. In CAPD patients with peritonitis, there was a sharp increase in the PDE levels of HA, IL-1β, and IL-6. These values decreased progressively with resolution of peritonitis. The changes in the PDE levels of HA closely followed those of IL-1β or IL-6. In vitro [3H]-glucosamine incorporation studies suggest that the main bulk of HA is derived from synthesis by the peritoneal mesothelial cells, whereas the amount synthesized by macrophages is trivial. We conclude that elevated levels of HA found in the PDE of stable CAPD patients originate from increased synthesis by peritoneal mesothelial cells. This event may serve as a marker of regeneration and remodeling of the peritoneal lining.link_to_subscribed_fulltex

Diabetic nephropathy and endothelial dysfunction : current and future therapies, and emerging of vascular imaging for preclinical renal-kinetic study

2016-2017 > Academic research: refereed > Publication in refereed journal201812_a bcmaVersion of RecordPublishe

Cardiovascular protective effects of salvianic acid a on db/db mice with elevated homocysteine level

2017-2018 > Academic research: refereed > Publication in refereed journal201811_a bcmaVersion of RecordPublishe

Complement and renal ischemia-reperfusion injury

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Longitudinal study of peritoneal membrane function in continuous ambulatory peritoneal dialysis: Relationship with peritonitis and fibrosing factors

◆ Background: The peritoneal equilibration test (PET) is a useful assessment of peritoneal function in continuous ambulatory peritoneal dialysis (CAPD) patients. However, the natural course of longitudinal change in peritoneal transport is not well defined. ◆ Patients: We studied 105 unselected CAPD patients. Average age at enrollment was 50.7 ± 11.3 years. ◆ Methods: A PET was performed at enrollment. Peritoneal transport was expressed as dialysate-to-plasma creatinine ratio at 4 hours (D/P). Fibrosing factors and mesothelial cell markers, including TGFβ, epidermal growth factor (EGF), platelet-derived growth factor (PDGF), hyaluronan, and cancer antigen 125 (CA125), were measured in overnight peritoneal dialysate effluent (PDE). Patients were followed for two years. Peritonitis episodes were recorded. Severe peritonitis was defined as an episode that required catheter removal or antibiotic therapy for more than 3 weeks. After two years, 75 patients were still alive and on CAPD. ◆ Results: The PET was repeated in 64 patients, of whom 35 were male and 9 had diabetes. The change in D/P over two years was represented as ΔD/P. No significant change in peritoneal transport was seen after two years (D/P: 0.56 ± 0.12 vs 0.55 ± 0.13). A centripetal pattern of change in D/P was observed. The ΔD/P had normal distribution and was inversely correlated with D/P at baseline (r = -0.427, p < 0.005). Both results suggest a regression-to-mean phenomenon. The ΔD/P had no significant correlation with the total number of peritonitis episodes (Spearman r = 0.052, p = 0.74), but after severe peritonitis, affected patients had higher ΔD/P than patients who experienced no severe infection (0.040 ± 0.136 vs -0.032 ± 0.120, p < 0.05). For patients with no episodes of severe peritonitis (n = 47), ΔD/P was weakly correlated with baseline TGFβ level (r = -0.506, p < 0.01). No correlation was seen between the levels of other fibrosing factors and change in peritoneal transport. ◆ Conclusions: Our findings suggest that the centripetal change of peritoneal transport probably reflects a regression-to-mean phenomenon. Peritoneal transport increases after severe peritonitis. The role of TGFβ levels in PDE with regard to longitudinal change in peritoneal transport requires further study.link_to_subscribed_fulltex