OBJECTIVETo evaluate the transdermal permeability of glucosamine sulfate solution across ex vivo rabbit dermis under ultrasound and optimize the ultrasound conditions.

METHODSThe ultrasound-assisted transdermal permeation of glucosamine sulfate solution across ex vivo rabbit dermis was tested using a simple Franz diffuse. The transdermal permeation volume and rate were calculated by measuring the concentration of glucosamine sulfate in the receptor fluid with ultraviolet spectrophotometry, and the impact of different sound intensities, irradiation time and solution concentration on solution permeation was analyzed.

RESULTSAt the ultrasound intensity of 0.2 W/cm(2), the permeation volume and rate of glucosamine sulfate both reached the maximum; no glucosamine sulfate was detected in the receptor fluid after a 5-min ultrasound irradiation. The permeation volume and rate of glucosamine sulfate increased as the irradiation time prolonged and also with increased glucosamine sulfate concentration. The dorsal and lateral skin thickness (2.0∓0.1 and 1.2∓0.1 mm, respectively) did not significantly affect the transdermal permeation of glucosamine sulfate (P>0.05).

CONCLUSIONUltrasound irradiation at 1.0 MHz for over 5 min allows glucosamine sulfate to permeate rabbit dermis, and the volume and rate of permeation increase with the irradiation time and concentration of the solution and are not affected by variations of the dermal thickness.

Administration, Cutaneous ; Animals ; Dermis ; diagnostic imaging ; drug effects ; Glucosamine ; metabolism ; In Vitro Techniques ; Permeability ; Rabbits ; Skin Absorption ; Ultrasonics ; Ultrasonography

Objective To investigate the difference between self-perceived risk and objective risk of stroke in the elderly population in Haikou area and explore the related factors in order to deter-mine the role of stroke knowledge in self-perceived risk.Methods A cross-sectional questionnaire survey was conducted on 584 elderly patients who were selected by convenience sampling from those taking physical examination in the First Affiliated Hospital of Hainan Medical College from September 2022 to April 2023.According to the accuracy of self-perceived risk of stroke,they were divided into an under-estimation group(170 cases),an accurate-estimation group(329 cases)and an over-estimation group(85 cases).Their self-perceived risk of stroke was assessed with the Stroke Risk Perception Questionnaire,and the objective risk of stroke was assessed with the Screening Criteria of Stroke High-Risk Group Screening Intervention Project of National Health Commission.Multivariate logistic regression model was used to analyze the factors related to the accuracy of self-perceived risk of stroke.One-way ANOVA was used to analyze the correlation be-tween the accuracy of self-perceived stroke risk and stroke knowledge.Results The participants with low,moderate,and high self-perceived risk of stroke accounted for 75.5％,20.5％and 3.9％,respectively.Compared with the objective risk assessment,the percentages of the participants with self-perceived stroke risk were 29.1％,56.3％and 14.6％,respectively,in the under-,accurate-and over-estimation groups.Significant differences were observed in gender,education level,smoking,drinking,exercise,fatty diet,fruit,overweight or obesity,and dyslipidemia among all groups(P＜0.05,P＜0.01).Multivariate logistic regression analysis showed that smoking,regular exercise,overweight or obesity and dyslipidemia were associated with accuracy of stroke risk perception in the accurate and the over-estimation groups when the under-estimation group was regarded as control(P＜0.01).The total score of stroke knowledge was 6.81±3.63,7.17±3.47 and 8.07± 3.24,respectively in the 3 estimation groups.The accuracy of self-perceived stroke risk was corre-lated with stroke knowledge(F=3.756,P=0.024).Conclusion Targeted health education should be implemented to make the elderly establish correct awareness of stroke risk,promote healthy behaviors and habits,and achieve the goal of early stroke prevention.