Student academic performance in non-lecture physiology topics following the abrupt change from traditional on-site teaching to online teaching during COVID-19 pandemic.

BACKGROUND: During the COVID-19 pandemic, pre-clerkship medical education, including all physiology classes, was obliged to change to online teaching due to limitations of on-site (face-to-face) classes. However, the effectiveness of online teaching in non-lecture physiology topics during the COVID-19 pandemic has not been thoroughly investigated. METHOD: We conducted a prospective study to evaluate the students' academic achievement and opinions on online teaching during the COVID-19 academic year. Academic achievement of 312 students in the COVID-19 year was compared with that of 299 students in the pre-COVID-19 year. Student opinions regarding social interactions and the preferred learning method were also collected. RESULTS: We found that student academic achievement in the non-lecture physiology topics, assessed by summative scores, was 4.80±0.92 percent higher in the pre-COVID-19 year than in the COVID-19 year (P < 0.01, Cohen's d = 0.42). Students rated that online classes tended to reduce their interactions with peers and teachers; however, students preferred online learning over traditional on-site learning. CONCLUSIONS: This study pointed out that students' academic performance related to the physiology topics taught by online non-lecture methods during the COVID-19 pandemic was lower than their performance when the topics were taught by the traditional (on-site) methods, although students reported that they preferred the online teaching. Hence, we suggest that medical teachers should deliberately plan and utilise a variety of tools and techniques when developing online non-lecture classes to preserve the interactivity of the classes, which might overcome this gap in students' academic performance.

The effects of oral Aloe vera on the efficacy of transplanted human endothelial cells and the expression of matrix metalloproteinases in diabetic wound healing.

BACKGROUND: Diabetic wounds are characterized by delayed healing and impaired angiogenesis. Aloe vera and human umbilical vein endothelial cells (HUVECs) are reported to facilitate wound healing, and the former also has hypoglycemic property. Matrix metalloproteinases are enzymes that play a role in diabetic wound pathogenesis. OBJECTIVE: To investigate whether oral Aloe vera can enhance the efficacy of HUVEC transplantation and inhibit the expression of matrix metalloproteinases in wound healing of diabetic mice. MATERIALS AND METHODS: BALB/c nude mice were randomly assigned into five groups: normal control group, diabetic group (DM), DM transplanted with HUVECs, DM treated with oral Aloe vera, and DM treated with combined HUVECs and oral Aloe vera. Diabetes was induced by streptozotocin. Bilateral full-thickness excision cutaneous wounds were created. At days 7 and 14 post-wounding, the following parameters were determined: blood glucose, wound area, wound perfusion, capillary vascularity, re-epithelialization rate and tissue VEGF levels. Tissue expressions of MMP-2 and MMP-9 were compared between the DM mice and those treated with oral Aloe vera. RESULTS: Over days 7 and 14, Aloe vera exerted glucose-lowering effect in diabetic mice. Higher wound closure rate, blood flow and capillary vascularity, and lower MMP-2 and MMP-9 expressions were observed at both time points in DM treated with Aloe vera group compared with DM group (P < 0.05). Moreover, combined therapy of HUVECs and oral Aloe vera was more effective than Aloe vera or HUVECs alone in increasing VEGF levels, capillary vascularity and wound perfusion. Blood glucose levels were negatively correlated with angiogenesis (P = 0.000. CONCLUSION: It is suggested that oral Aloe vera enhances the efficacy of HUVEC transplantation on diabetic wound angiogenesis, partly through improving glycemic control. Oral Aloe vera also promotes diabetic wound healing via inhibition of MMP-2 and MMP-9 expressions.

The effects of whole-body vibration on wound healing in a mouse pressure ulcer model.

BACKGROUND: Pressure ulcers are one of the most common complications of immobility resulting from pressure and shear. Whole-body vibration (WBV) has been shown to increase skin blood flow but little information is known about its effect on pressure ulcers. This study investigated the effects of WBV on wound healing in a mouse pressure ulcer model. METHODS: Two cycles of ischemia-reperfusion were performed by external application of two magnetic plates to dorsal skin to induce stage II pressure ulcers characterized by partial-thickness skin loss with exposed dermis. A total of 32 male ICR mice were randomly and equally divided into untreated control and the WBV groups. Immediately after the completion of 2-cycle ischemia-reperfusion injury, mice in the WBV group participated in a WBV program using a vibrator (frequency 45 Hz, peak acceleration 0.4 g, vertical motion) for 30 min/day and 5 consecutive days/week. At days 7 and 14 post-ulceration, wound closure rate was assessed. Wound tissues were harvested for determination of collagen deposition in Masson's trichrome stained sections, neutrophil infiltration and capillary density in hematoxylin and eosin-stained sections, as well as TNF-α and VEGF levels using ELISA. RESULTS: TNF-α levels and neutrophil infiltration were significantly decreased in wounds on days 7 and 14 of WBV treatment. Moreover, wound closure rate and collagen deposition were remarkably accelerated on day 14. Tissue VEGF and capillary density were unaffected by WBV at either time point. CONCLUSIONS: These findings suggest that WBV has the potential to promote the healing process of stage II pressure ulcers, as evidenced by attenuation of wound inflammation and enhancement collagen deposition.

Minimization of the Risk of Diabetic Microangiopathy in Rats by Nigella sativa.

BACKGROUND: Microangiopathy is a chronic diabetic complication resulting from metabolic derangements, oxidative stress, and increased pro-inflammatory cytokine production. Nigella sativa Linn. is used as an herbal medicine that exerts hypoglycemic, antilipidemic, anti-inflammatory, and antioxidant effects. OBJECTIVE: To examine the effects of N. sativa extract on cutaneous microvascular changes in diabetic rats. MATERIALS AND METHODS: Sprague-Dawley rats were randomly assigned into the following four groups: Untreated and N. sativa-treated normal controls and untreated and N. sativa-treated rats with streptozotocin-induced diabetes. A cold-pressed N. sativa extract was then orally administered (1000 mg/kg/day). After 8 weeks of treatment, the glucose, glycosylated hemoglobin (HbA1c), tumor necrosis factor-alpha (TNF-α), insulin levels, and lipid profile were determined in cardiac blood. Dermal capillary wall thickness was measured in tail skin sections stained with periodic acid-Schiff. Endothelial apoptosis was morphologically evaluated by hematoxylin and eosin staining. RESULTS: Diabetes significantly reduced the circulating insulin and low-density lipoprotein levels and caused elevations in the glucose, HbA1c, and triglyceride levels, accompanied by a slight increase in total cholesterol levels and no change in the high-density lipoprotein and TNF-α levels. Capillary basement membrane thickening and a decreased capillary luminal diameter despite no evidence of endothelial cell apoptosis were also observed. N. sativa treatment of diabetic rats reduced the mean HbA1c concentration by 1.4%, enlarged the capillary lumens, and tended to attenuate dermal capillary basement membrane thickening without affecting the lipid profile or TNF-α level. CONCLUSION: Our results indicate that N. sativa may be used to minimize the risk of diabetic microangiopathy, potentially due in part to its glycemic control activity. SUMMARY: Diabetes causes dermal capillary basement membrane thickening and a decreased capillary luminal diameterNigella sativa treatment of diabetic rats enlarged the capillary lumens and tended to attenuate dermal capillary basement membrane thickeningN. sativa treatment of diabetic rats reduced the mean glycosylated hemoglobin concentration by 1.4%, which exceeds the necessary reduction previously described to decrease the risk of diabetic microangiopathy, without affecting the lipid profile or tumor necrosis factor-alpha levelN. sativa improves rat diabetic microangiopathy, potentially due in part to its glycemic control activity. Abbreviations used: H and E: Hematoxylin and eosin, HbA1c: Glycosylated hemoglobin, HDL-C: High-density lipoprotein cholesterol, LDL-C: Low-density lipoprotein cholesterol, PAS: Periodic acid-Schiff, STZ: Streptozotocin.

Moderate-intensity exercise training elevates serum and pancreatic zinc levels and pancreatic ZnT8 expression in streptozotocin-induced diabetic rats.

AIMS: Diabetes mellitus is associated with disturbed zinc homeostasis and down-regulation of zinc transporter 8 (ZnT8); these changes contribute to the defective biosynthesis, storage, and secretion of insulin. Previous studies have reported an improvement in diabetic status and insulin levels in diabetic rats that underwent moderate exercise training, but the mechanisms underlying this effect remain unclear. Evidence shows that exercise training increases the zinc content in the muscle, liver, and kidney of diabetic rats and increases the expression of several types of zinc transporters in the rat hippocampus. We hypothesised that moderate exercise training may increase serum and pancreatic zinc levels, as well as pancreatic ZnT8 expression, in diabetic rats. MAIN METHODS: Wistar rats were divided into 3 equally sized groups: sedentary normal control, sedentary diabetic, and exercise-trained diabetic groups. Diabetes was induced by an intraperitoneal injection of streptozotocin. The 6-week exercise training intervention involved 30 min of moderate-intensity running on a treadmill once daily (5 days/week). At the end of the study, the concentrations of serum and pancreatic zinc were determined using atomic absorptive spectrophotometry. Pancreatic ZnT8 expression was analysed by quantitative real-time RT-PCR. KEY FINDINGS: Diabetes caused reductions in the serum and pancreatic zinc levels and pancreatic ZnT8 expression. Following moderate exercise training, there was a significant increase in all of these parameters. SIGNIFICANCE: The ability of moderate exercise training to ameliorate the reductions in serum and pancreatic zinc levels and pancreatic ZnT8 expression can partly explain the beneficial effects of exercise training in diabetes.

Assessment of preclinical students' academic motivation before and after a three-day academic affair program.

BACKGROUND: Medical students' motivation is an important driving factor for academic performance, and therefore medical teachers and educators are often highly interested in this topic. This study evaluated the impact of an academic affair program upon preclinical year medical students' motivation to study. DESIGN AND METHODS: An intervention study was conducted using a pretest-posttest study design. A total of 296 preclinical year medical students who had just passed their first year and were about to attend their second year at the Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand, participated in the study. The intervention comprised of dialogues for personality development, pictorial expression in groups, as well as small group lectures delivered by senior students giving information on how to prepare for the forthcoming classes. Students' academic motivation was measured before and after the intervention program, applying the transculturally translated Academic Motivation Scale (AMS). Cronbach's alpha of Thai version AMS was 0.8992. The average scores in seven scales of AMS were compared between the pre- and posttest results, using the Wilcoxon signed-rank test. The differences were confirmed by using the multivariate analysis of variance. RESULTS: Students' academic motivation increased after participation in the three-day academic program. There was also a significant increase in introjected extrinsic motivation, which can enhance the students' self-esteem and feeling of self-worth (P<0.001). Moreover, intrinsic motivation toward accomplishment increased significantly (P<0.001). This is related to the enjoyment of passing academic milestones, and a step ahead of autonomous motivation. Amotivation level declined significantly (P<0.001). The change of academic motivational constructs before and after the intervention was altogether significant (P=0.036, multivariate analysis of variance). CONCLUSION: After experiencing a three-day intervention, the new students' motivation advanced along the continuum of self-determination toward autonomous motivation. Therefore, it is considered to be worthwhile conducting an academic intervention to catalyze the evolution of preclinical year medical students' academic motivation. Moreover, educators and faculties should evaluate the impact of interventions in evidence-based approaches to secure both controlled and autonomous types of motivation.

Core temperature changes and sprint performance of elite female soccer players after a 15-minute warm-up in a hot-humid environment.

Warm-up session should be modified according to the environmental conditions. However, there is limited evidence regarding the proper soccer warm-up time for female players in the heat. The purpose of this study was to examine the rise in core body temperature and the sprint performance after a 15-minute warm-up in a hot-humid environment using female soccer players during the different phases of their menstrual cycle. Thirteen eumenorrheic national female soccer players (aged 18.8 ± 1.3 years, (Equation is included in full-text article.)53.05 ± 6.66 ml·kg·min) performed a 15-minute warm-up protocol at an ambient temperature of 32.5 ± 1.6° C with a relative humidity of 53.6 ± 10.2% during their early follicular and midluteal phases of their cycle. The warm-up protocol is composed of jogging, skipping by moving the legs in various directions, and sprinting alternated with jogging, followed by a 45-minute recovery period. Rectal temperatures were recorded during the rest period and every 5 minutes throughout the warm-up and recovery phases of the study. Heart rate was monitored at rest and every 5 minutes during the warm-up. Forty-yard sprint time was assessed immediately after the completion of warm-up, which was later compared with the time at baseline. The value for the baseline was obtained at least 2 days before the experiment. During the early follicular and midluteal phases, the rectal temperatures obtained at the end of the warm-up period were significantly (p < 0.05) higher by 1.26° C (95% confidence interval [CI] = +0.46 to +2.06° C) and 1.18° C (95% CI = +0.53 to +1.83° C), whereas the heart rates increased to 153.67 ± 20.34 and 158.38 ± 15.19 b·min, respectively. After 20 minutes of the recovery period, the rectal temperature decreased by approximately 50%. The sprint times were significantly (p < 0.05) faster post-warm-up during both the early follicular (5.52 seconds; 95% CI = 5.43-5.60 seconds) and midluteal phases (5.51 seconds; 95% CI = 5.41-5.60 seconds) compared with the baseline time (5.66 seconds; 95% CI = 5.58-5.74 seconds). There were no significant differences in any parameters assessed after warm-up between the 2 phases. In conclusion, a 15-minute warm-up increased the core temperature by approximately 1° C and improved the 40-yd sprint time for elite female soccer players in a hot environment regardless of menstrual phase.

Wound healing activities of different extracts of Centella asiatica in incision and burn wound models: an experimental animal study.

BACKGROUND: The efficacy of Centella asiatica for incision and burn wounds are not fully understood. Here, we report the wound healing activities of sequential hexane, ethyl acetate, methanol, and water extracts of Centella asiatica in incision and partial-thickness burn wound models in rats. METHODS: Male Sprague-Dawley rats weighing 250-300 g were randomly divided into incision and burn wound groups. Each group was stratified into seven subgroups: (1) untreated; (2) NSS-; (3) Tween 20®- (vehicle control); (4) hexane extract-; (5) ethyl acetate extract-; (6) methanol extract-; and (7) aqueous extract-treated groups. The test substances were applied topically once daily. The tensile strength of the incision wound was measured on the seventh day after wound infliction. The general appearance and degree of wound healing of the burn wound were assessed on Days 3, 7, 10 and 14 after burn injury and prior to histopathological evaluation. RESULTS: On the seventh day after wound infliction, the tensile strength of incision wound in all extract-treated groups was significantly higher than that of the vehicle control (Tween 20®), but comparable to the NSS-treated group. The degrees of healing in the burn wound with the four extracts were significantly higher than that of the control on Days 3, 10 and 14. Histopathological findings on Day 14 after burn injury revealed prominent fibrinoid necrosis and incomplete epithelialization in the control and untreated groups, whereas fully developed epithelialization and keratinization were observed in all extract-treated groups. Analysis by thin layer chromatography demonstrated that the phyto-constituents ß-sitosterol, asiatic acid, and asiaticoside and madecassocide were present in the hexane, ethyl acetate and methanol extracts, respectively. CONCLUSIONS: All extracts of Centella asiatica facilitate the wound healing process in both incision and burn wounds. Asiatic acid in the ethyl acetate extract seemed to be the most active component for healing the wound.

Heat illness surveillance in schoolboys participating in physical education class in tropical climate: an analytical prospective descriptive study.

OBJECTIVES: This study aimed to determine thermoregulatory and cardiovascular responses as well as the occurrence of heat illness in children exercising outdoors in physical education class under hot and humid climate. Little information regarding this issue under real-life situation is available, especially in the Southeast Asia. DESIGN: Analytical, prospective descriptive study. SETTING: A primary school in Bangkok, Thailand. PARTICIPANTS: A total of 457 schoolboys (aged 5.5-12 years) were observed while exercising outdoors during their physical education classes throughout the academic year of 2009, including semester 1 (between July and September 2009) and semester 2 (between November 2009 and February 2010). PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcome measure was tympanic temperature. Secondary outcome measures included blood pressure, heart rate, hydration status and the occurrence of heat-related illness. RESULTS: Outdoor physical activity consisted of skill practice (duration 24.11±11.04 min, intensity <3 metabolic equivalent of tasks) and playing sports (duration 11.48±5.53 min, intensity 2.6-8.8 metabolic equivalent of tasks). After exercise, tympanic temperature increased by 0.66±0.41°C. There were 20 (4.4%) students whose ear temperature exceeded 38°C, 18 of whom did not consume water. The RR of increasing body temperature up to 38°C in overweight students was 2.1-fold higher than normal-weight students. The per cent change in mean arterial pressure and heart rate increased by 20.16±15.34% and 23.94±19.78%, respectively. Sweat and dehydration rates were 391.16±186.75 ml/h and 0.63±0.26%, respectively. No evidence of heat illness was found. Wet bulb globe temperatures of semesters 1 and 2 were 29.95±1.87°C and 28.32±2.39°C, respectively. CONCLUSIONS: There is an increased risk for heat illness during outdoor activities in physical education class in primary school children, especially those who are overweight and have poor hydration status.

The therapeutic efficacy and properties of topical Aloe vera in thermal burns.

Aloe vera has been used as a popular herbal medicine since ancient times for many conditions including burns. Much evidence has reported the efficacy of topical Aloe vera gel in the treatment of thermal burns through its different pharmacological actions. This review article consists of pathophysiology of the thermal burns, the botany and chemical constituents of Aloe vera, and therapeutic properties of Aloe vera on thermal burns. The mechanisms that may underlie its action include: anti-inflammation, antimicrobials, wound healing promotion, and biological/immunological modulation.