Aerobic Exercise of Low to Moderate Intensity Corrects Unequal Changes in BKCa Subunit Expression in the Mesenteric Arteries of Spontaneously Hypertensive Rats

Accumulating evidence indicates that hypertension is associated with “ion channel remodeling” of vascular smooth muscle cells (VSMCs). The objective of this study was to determine the effects of exercise intensity/volume on hypertension-associated changes in large-conductance Ca2+-activated K+ (BKCa) channels in mesenteric arteries (MAs) from spontaneously hypertensive rats (SHR). Male SHRs were randomly assigned to three groups: a low-intensity aerobic exercise group (SHR-L: 14 m/min), a moderate-intensity aerobic exercise group (SHR-M: 20 m/min), and a sedentary group (SHR). Age-matched Wistar-Kyoto rats (WKYs) were used as normotensive controls. Exercise groups completed an 8-week exercise program. Elevation of the α and β1 proteins was unequal in MA myocytes from SHRs, with the β1 subunit increasing more than the α subunit. BKCa contribution to vascular tone regulation was higher in the myocytes and arteries of SHRs compared to WKYs. SHR BKCa channel subunit protein expression, β1/α ratio, whole cell current density and single-channel open probability was also increased compared with WKYs. Aerobic exercise lowered systemic blood pressure and normalized hypertension-associated BKCa alterations to normotensive control levels in the SHRs. These effects were more pronounced in the moderate-intensity group than in the low-intensity group. There is a dose-effect for aerobic exercise training in the range of low to moderate-intensity and accompanying volume for the correction of the pathological adaptation of BKCa channels in myocytes of MAs from SHR.

The frequency and nature of drug administration error during anaesthesia in a Chinese hospital

BACKGROUND

Throughout the world, drug administration error remains a known and significant threat to patients undergoing anaesthesia. Estimates of the extent of the problem vary, but few are based on large prospectively collected datasets. Furthermore, little is known about whether differences in work culture are important in error rates.

METHODS

A prospective incident monitoring study was conducted at a large tertiary hospital in China to estimate the frequency of drug administration error during anaesthesia. Anaesthetists were asked to return a study form anonymously for every anaesthetic, indicating whether or not a drug administration error had occurred, including incident details if affirmative.

RESULTS

From 24,380 anaesthetics, 16,496 study forms were returned (67.7% response rate), reporting 179 errors. The frequency (95% confidence interval) of drug administration error was 0.73% (0.63% to 0.85%) based on total study anaesthetics and 1.09% (0.93% to 1.26%) based on total forms returned. The largest categories of error were omissions (27%), incorrect doses (23%) and substitutions (20%). Errors resulted in prolonged stay in recovery for 21 patients, transfer to the ICU for five and one case each of haemorrhagic shock and asthmatic attack. More respondents who were not fully rested reported inattention as a contributing factor to error (21%) than those who were fully rested (7%, P = 0.04).

CONCLUSION

Our results are comparable with other international prospective estimates indicating that drug administration error is of concern in China as elsewhere. These results will form a baseline from which to detect the effects of countermeasures.

STUDY OF CHITOSAN COATINGS ON NANOPARTICLES FOR BIOMEDICAL APPLICATIONS

Of late, much work and interest had been generated in the fields involving nanoparticles. Due to their nanometer scale, these particles have been proven to be promising in diverse applications such as electronics and medicine, amongst others. In addition, an emerging and attractive use of nanoparticles as biotherapeutic delivery agents within the body was introduced. However, in order to use these nanoparticles in any biomedical application, they must be rendered biocompatible.

In this paper, we attempt to coat chitosan, a naturally-occurring polymer which is biocompatible, biodegradable and nontoxic, onto the surfaces of nanoparticles. 5 nm gold ( Au ) nanoparticles were chosen for our study as they are commercially available. The presence of a chitosan shell not only renders these nanoparticles biocompatible, the amino and hydroxyl groups of chitosan also allow the immobilization of many biotherapeutic agents. The relationship between the concentration of the chitosan used in the coating process and the thickness of the chitosan shell formed is investigated. It is hoped that the results of this study can also be applied to other nanoparticles, in addition to Au , that are intended to be used in bioapplications.

Biocompatibility and bioactivity of plasma-treated biodegradable poly(butylene succinate)

Poly(butylene succinate) (PBSu), a novel biodegradable aliphatic polyester with excellent processability and mechanical properties, is a promising substance for bone and cartilage repair. However, it typically suffers from insufficient biocompatibility and bioactivity after implantation into the human body. In this work, H(2)O or NH(3) plasma immersion ion implantation (PIII) is conducted for the first time to modify the PBSu surface. Both the treated and control specimens are characterized by X-ray photoelectron spectroscopy, contact angle measurements and atomic force microscopy. The plasma treatments improve the hydrophilicity and roughness of PBSu significantly and the different PIII processes result in similar hydrophilicity and topography. C-OH and C-NH(2) functional groups emerge on the PBSu surface after H(2)O and NH(3) PIII, respectively. The biological results demonstrate that both osteoblast compatibility and apatite formability are enhanced after H(2)O and NH(3) PIII. Furthermore, our results suggest that H(2)O PIII is more effective in rendering PBSu suitable for bone-replacement implants compared to NH(3) PIII.