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 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.

Changes of vitamin D receptors (VDR) and MAPK activation in cytoplasmic and nuclear fractions following exposure to cigarette smoke with or without filter in rats

Cigarette smoke (CS) is a major cause of obstructive lung disease which is associated with significant disability and mortality. Vitamin D receptor (VDR) together with, mitogen activated protein kinases (MAPKs; ERK, JNK and p38) are the cellular transmission signals that mechanistically respond to CS and are recently found to have a role in lung pathogenesis. There are a few in vitro studies on subcellular VDR distribution involved MAPK but in vivo effects of cigarette smoke exposure with and without filter on this complex remain unclear. This study investigated subcellular VDR distribution and MAPK expression at early stages of both types of cigarette smoke exposure (CSE) in a rat model. Male Wistar rats were randomly divided into no-filter, filter and control groups. After 7 and 14 days of CSE, lung tissues were obtained to determine histopathology and protein expression. Cytoplasmic and nuclear VDR distribution significantly decreased on both CSE groups and corresponded with immunohistochemistry detection. The ratio of phosphorylated ERK to total ERK significantly increased in cytoplasm of both CSE on day 7. In particular, nuclear ERK MAPK significantly escalated in the filter group on day 14. In consistent with changes in intracellular markers, histopathological examination in both CSE groups showed significant increases in tracheal and peribronchiolar epithelial proliferation, alveolar macrophages and an increased trend of parenchymal infiltration. In summary, the evidence of lung injuries along with VDR depletion and MAPK activation observed in both CSE types indicated that there was no benefit of using cigarette filter to prevent protein damage or protect cells against cigarette smoke exposure in this model.

Intermittent hypoxia in rat enhancing peritoneal membrane thickening through HIF-1α-induced cytokines in peritoneum

BACKGROUND

Due to the high prevalence of both obstructive sleep apnea syndrome (OSA) and end-stage renal disease (ESRD), the co-existence of both conditions in peritoneal dialysis is demonstrated. Because OSA-induced chronic intermittent hypoxia is well-known, the hypoxia might worsen peritoneal membrane.

OBJECTIVE

We tested the influence of chronic intermittent hypoxia upon peritoneal membrane in a Sprague-Dawley rat model.

METHODS

Normal saline or 3.86% glucose peritoneal dialysis fluid (PDF) were intra-peritoneally administered twice a day as negative (NSS group) and positive controls (PDF group), respectively. Intermittent hypoxia was induced by using a hypoxic chamber with 10% O2 for 8 hours a day plus twice-daily NSS injection (IH group).

RESULTS

At 12 weeks of the experiments, high serum TNF-α and IL-6 (but not IL-10) with normal renal and liver functions were demonstrated in the IH group (but not the PDF group). In parallel, local cytokines (TNF-α, IL-6, and IL10 in peritoneal membrane) and peritoneal membrane thickness were increased whereas peritoneal membrane hypoxia (hypoxyprobeTM and hypoxia-inducible factor-1α; HIF-1α) was induced in both PDF and IH groups (more prominent in the PDF group). However, the increased vascular density in submesothelial area was established only in the PDF group.

CONCLUSION

Intermittent hypoxia model induced local peritoneal membrane inflammation and enhanced peritoneal membrane thickness, at least in part, through a mechanism of hypoxia-induced HIF-1α. Although peritoneal membrane alterations from PDF were more prominent than intermittent hypoxia, the combination between intermittent hypoxia with PDF utilization might facilitate peritoneal membrane failure, which will need more study.

Exercise intolerance in obese children and adolescents

Background: Abnormal lung function has been reported in the obese population and is associated with the severity of obesity.

Objectives: To identify abnormal lung function in obese children and adolescents, and examine the cardiopulmonary response of those who have abnormal lung functions during exercise, and to reveal predictors of exercise intolerance in this population.

Methods: Fifty obese participants aged 8–18 years (56% male; mean age 13.2 ± 2.0 years; mean BMI 33.0 ± 3.6 kg/m2, mean BMI z score 3.1 ± 0.3) underwent spirometry, lung volume evaluation, and a cardiopulmonary exercise test.

Results: Lung function abnormalities and exercise intolerance because of pulmonary limitations were found in 36% and 74% of the participants, respectively. A comparison of participants with normal and abnormal lung functions revealed a lower breathing reserve and a higher ventilatory equivalent for CO2 production (VE/VCO2) during exercise in those who had lung function abnormalities (18 ± 15 vs 30±10%, P <0.001 and 30.3 ± 3.3 vs 29.6 ± 3.1; P = 0.02, respectively). Exercise intolerant participants had a higher BMI z score compared with those who were not (3.1 ± 0.3 vs 2.9 ± 0.3; P = 0.03). BMI z score ≥ 2.84 had an 80% sensitivity and 67% specificity for predicting exercise intolerance in this population.

Conclusions: Evaluations of lung function and exercise capacity should be included in the follow-up planning for obese children and adolescents. A BMI z score ≥ 2.84 was most sensitive for predicting exercise intolerance in this population.

Resting Energy Expenditure Measured by Indirect Calorimetry in Infants and Young Children with Chronic Lung Disease

OBJECTIVE

To determine resting energy expenditure (REE) by indirect calorimetry and to compare measured resting energy expenditure (mREE) by indirect calorimetry with prediction equations (pREE).

MATERIAL AND METHOD

Infants and young children with chronic lung diseases from King Chulalongkorn Memorial Hospital were enrolled and assessed for nutritional status and severity of chronic lung diseases. For mREE, indirect calorimetry was performed by custom-made airtight canopy with O2 and CO2 sensors, with the patients were in a resting state. Prediction equations were Food and Agriculture/World Health Organization/United Nations University (FAO/WHO/UNU), Schofield-Weight, Schofield-Weight/Height, Harris Benedict, and Harris Benedict-Infant equations. Agreement between mREE and pREE was assessed by Bland-Altman method.

RESULTS

Eighteen patients (median age 6 months, range 1 to 26 months) were recruited. Sixteen children had weight for age Z-score below -2 SD. Median weight for age Z-score, length for age Z-score and weight for length Z-score were -3.0, -3.1, and -1.9, respectively. Median mREE was 53.8 kcal/kg/day (interquartile range 47.5 to 72.6 kcal/kg/day). The Schofield-Weight/Height equation showed the lowest mean of difference at 0.94 kcal/kg/day with 95% confidence interval for the bias -44.4 to 46.3 kcal/kg/day.

CONCLUSION

To ensure optimal nutritional support, REE should be measured by indirect calorimetry in pediatric patients with chronic lung diseases. Based on our finding, the Schofield-Weight/Height equation was the most accurate equation for predicting REE in this group of patients.

Effects of Precooling with Cold Water Ingestion on Thermoregulatory Response of Obese Men during Moderate Intensity Exercise in Hot and Humid Environment

OBJECTIVE

1) To determine rectal temperature (Tre) and fluid loss (FL) of obese men (OM) compared to non-obese men (NM) during exercise in cool conditions (CC) and hot and humid conditions (HC), and 2) to investigate the effects of cold water (CW; 0.5 ± 0.5°C) ingestion before exercise in HC in OM MATERIAL AND METHOD: Twelve OM and 12 NM completed 2 treadmill exercise sessions, in CC and HC, in a randomized order Each session was performed for 30 minutes at 45-50% of heart rate reserve with a 5-minute warm up and 5-minute cool down.

RESULTS

There were no differences in Tre in response to exercise between OM and NM both in CC (OM 37.77 ± 0.08°C, NM 37.68 ± 0.08°C; p = 0.463) and in HC (OM 37.82 ± 0.06°C, NM 37.85 ± 0.06°C; p = 0.725). Heart rate, perceived exertion and thermal sensations were not significantly different between OM and NM. However, compared to NM, fluid loss (FL) was approximately 160 mL greater in OM (OM 443.33 ± 98.65 mL, NM 283.33 ± 108.15 mL; p ≤ 0.001) in CC, and was 194 mL greater (OM 632.50 ± 126.57 mL, NM 438.33 ± 126.62 mL; p ≤ 0.001) in HC. In HC, the 12 OM performed additional 2 bouts of exercise, with CW vs. ambient temperature water (AW; 30.5 ± 0.5°C) ingestions prior to the start of exercise. Precooling with CW ingestion, compared to AW ingestion, showed no significant difference in Tre but CW was able to reduce FL (CW 646.67 ± 139.82 mL, AW 735 ± 126.95 mL; p = 0.010).

CONCLUSION

OM may continuously exercise about 30 minutes at moderate intensity in HC without the increase of Tre to dangerous levels. However, OM should drink approximately 200 mL more water in HC and 160 mL more water in CC than NM. Precooling with CW ingestion is a good method of reducing risk of exertional heat illnesses in obese individuals during exercise in HC, as it decreases the amount of FL induced by exercise.

Effect of a low-carbohydrate diet on respiratory quotient of infants with chronic lung disease

OBJECTIVE

To compare the respiratory quotient in infants with chronic lung disease before and after receiving a modular diet with slightly lower carbohydrate content.

MATERIAL AND METHOD

Infants with chronic lung disease from the King Chulalongkorn Memorial Hospital were enrolled and assessed for nutritional status, severity of chronic lung disease and dietary intake. Indirect calorimetry was performed using a custom-made airtight canopy with O2 and CO2 sensors. Respiratory quotient (RQ) was calculated from VCO2/VO2 during the period they were fed low carbohydrates (37% of total calories) for at least 24 hours vs. a standard diet (47% carbohydrate). These two formulas were similar in terms of caloric density and protein content. Each patient received at least 100-150 kcal/ kg/day during the study period. Respiratory quotients of the same patient receiving the two diets were compared by using Wilcoxon signed-rank test.

RESULTS

A total of 14 patients (median age 7 months, range 1-26 months) were recruited. Twelve children had weight for age Z-score below-2SD. Their median weight for age Z-score, length for age Z-score and weight for length Z-score were -2.89, -3.08 and -1.24, respectively. The median RQ measured during the low carbohydrate diet was 0.96 (interquartile range 0.95-0.97), significantly lower than the median RQ during the standard diet, which was 1.04 (0.97-1.10). However, the respiratory rate revealed no significant difference. Two participants with underlying gastroesophageal reflux disease showed higher RQ after low carbohydrate formula feeding, which might be a result of hypersecretion due to its high fat content.

CONCLUSION

Diet with slightly lower carbohydrate content can reduce the RQ in infants with chronic lung disease compared to the standard enteral formula. A 10-percent reduction of carbohydrate content may provide a sizeable effect in this group of patients. Nevertheless, the clinical significance of this finding requires further investigation.

Pulmonary function and exercise capacity in children following lung resection surgery

PURPOSE

To study lung function and exercise capacity in children following lung resection surgery.

METHODS

Children aged 6-18 years who had lung resection surgery were studied and compared to normal children (age and sex matched). All had spirometry/body plethysmography and exercise stress test (performed by treadmill and modified Balke protocol).

RESULTS

13 Patients and 13 controls were studied (age 13.2 ± 3.3 years; 46.2 % male). The age at the time of lung resection surgery was 6.5 ± 4.7 years. The time interval between post-surgery and the tests was 6.8 ± 4.4 years. The most common indication for lung resection surgery was congenital lung malformations (61.5 %). 76.9 % of the patients had abnormal lung function. Exercise intolerance due to pulmonary limitations was found in 23.1 % of the patients. At the anaerobic threshold, the V(O2) was not different between the patients and the controls. However, at the end of the exercise, the patients demonstrated lower peak V(O2) than the controls (33.6 ± 6.0 vs. 39.3 ± 8.7 ml/min/kg; p < 0.01).

CONCLUSIONS

Abnormal lung functions and exercise intolerance were found in children following lung resection surgery. Children who had lung resection surgery had lower exercise capacity than normal children if the exercise was beyond the anaerobic threshold.

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.

Comparison of treatment outcomes between squamous cell carcinoma and adenocarcinoma in locally advanced cervical cancer

OBJECTIVE

To compare the treatment outcomes between squamous cell carcinoma (SCC) and adenocarcinoma (ACA) in locally advanced cervical cancer patients.

METHODS

All medical records of stages IIB-IVA of cervical cancer patients who had completed treatment between 1995 and 2008 were reviewed. ACA 1 case was matched for SCC 2 cases with clinical stage, tumor size, treatment modalities (radiation therapy (RT) vs concurrent chemoradiation (CCRT)). Treatment outcomes including response to RT/CCRT, time to complete response (CR), patterns of treatment failure and survival outcomes were analyzed.

RESULTS

A total of 423 patients with stages IIB-IVA (141 ACA: 282 SCC) were included. Most of the patients (about 60%) had stage IIB. The overall complete responses (CR) between ACA and SCC were 86.5% and 94.7%, respectively (p=0.004). Median time to clinical CR from RT/CCRT of ACA were 2 months (0-5 months) compared with 1 month (0-4 months) for SCC (p=0.001). Pelvic recurrence and distant failure were found in 2.1% and 14.9% in ACA, and corresponding with 3.9% and 15.6% in SCC. The 5-year overall survival rates of ACA compared to SCC were 59.9% and 61.7% (p=0.191), respectively. When all prognostic factors are adjusted, clinical staging was the only factor that influenced overall survival.

CONCLUSION

ACA in locally advanced cervical cancer had poorer response rate from treatment and also used longer time to achieve CR than SCC. However, these effects were not determinants of survival outcomes.

Low dose creatine supplementation enhances sprint phase of 400 meters swimming performance

This study demonstrated the effect of low dose creatine supplement (10 g. per day) on the sprinting time in the last 50 meters of 400 meters swimming competition, as well as the effect on exertion. Nineteen swimmers in the experimental group received creatine monohydrate 5 g with orange solution 15 g, twice per day for 7 days and nineteen swimmers in the control group received the same quantity of orange solution. The results showed that the swimmers who received creatine supplement lessened the sprinting time in the last 50 meters of 400 meters swimming competition than the control group. (p<0.05). The results of Wingate test (anaerobic power, anaerobic capacity and fatigue index) compared between pre and post supplementation. There was significant difference at p<0.05 in the control group from training effect whereas there was significant difference at p<0.000 from training effect and creatine supplement in the experiment group. Therefore, the creatine supplement in amateur swimmers in the present study enhanced the physical performance up to the maximum capacity.

Changes of immune system in military recruits after the training program

The aim of the exercise was to improve body health including the immune system function. However, several studies have observed the suppression of immune response in athletes who were trained with strenuous exercise. Recruits who have been in the recruitment-training program for 8 weeks might also have immune suppression. Twenty males, aged from 21 to 23 years in Chulachomklao Royal Military Academy infantry battalion volunteered to participate in this study. They were asked to wear a Polar Accurex Plus Telemetric heart rate monitor during the training period. Tuberculin skin test which is the screening method for cellular immune responses was significantly decreased at post-training compared to the pre-training (p<0.02). The levels of serum IgG and IgM at pre-training, 4th week, 8th week and one week post-training were significantly decreased at the initiation period, which were compared with pre-training and 4th week of training (p<0.01), and returned to normal at the 8th week of training and one week post-training. The level of circulating immune cells and number of CD markers (CD3, CD4, CD8, and CD56) were not significantly changed throughout the training period. This study demonstrated that subjects who underwent the recruit-training program were able to improve their health after the period of training i.e., in the adaptation period. The decrease in the initiation period could be compensated with proper diet and enough rest.

Energy expenditure and physical activity of obese and non-obese Thai children

The objective of this study was to assess the energy expenditure and physical activity in obese (n=21) and non-obese (n=21) children (aged 9-12 years) in Bangkok. Anthropometric measurements were performed. Energy expenditure and physical activity were determined by indirect calorimetry (based on oxygen consumption) and the heart rate monitoring method. Physical activity index was calculated by the ratio of total energy expenditure (TEE) to sedentary energy expenditure (SEE). The results showed that obese children had significantly greater (p<0.05) body weight, body mass index, relative weight, body fat (%), fat mass except for height, and fat free mass than the non-obese group. The TEE, SEE, and activity energy expenditure (AEE) were higher (p<0.05) in the obese children when compared with the non-obese ones. The mean values of respiratory quotient (RQ) were 0.91+/-0.06 in obese and 0.89+/-0.08 in the non-obese group, respectively, indicating the contribution of carbohydrate substrate to energy production. Both obese and non-obese children were similar in the physical activity index level of 1.48+/-0.17 and 1.51+/-0.22, respectively, which was lower than that recommended by the World Health Organization (1.7). In conclusion, energy expenditure of obese children was higher than non-obese children because of greater body weight. Furthermore, the physical activity of both groups was lower than that recommended by WHO. To prevent obesity in children, programmimg of exercise and activities as well as nutritional education should be emphasized for school children and parents.

Poor physical fitness of adolescents with mental retardation at Rajanukul School, Bangkok

OBJECTIVE

To study the physical condition of adolescents with mild to moderate mental retardation (MR), twenty-eight MR students from Rajanukul school were evaluated for their fitness components compared to 14 normal students.

METHOD

Per cent body fat (%BF) was calculated from three sites of skinfold thickness. The cardiorespiratory endurance was assessed using graded exercise testing and Quinton gas analyzer. Isometric leg strength was measured with dynamometer, and flexibility was measured by sit and reach test.

RESULTS

Compared between MR and normal subjects, %BF was higher in the MR group without statistic significance. Five MR females had %BF > 30. The mean VO2peak was about 70 per cent of normal. The leg strength and flexibility were very poor.

CONCLUSION

The MR adolescents had a significantly lower level of physical fitness and more prevalence of obesity than normal students. Appropriate physical activities should be emphasized for health promotion and disease prevention.

Acute effect of Russell's viper (Vipera russelli siamensis) venom on renal hemodynamics and autoregulation of blood flow in dogs

Renal hemodynamics and autoregulation of blood flow were investigated following intravenous injection of Russell's viper venom (0.1 mg/kg) in dogs anesthetized with sodium pentobarbital. After venom injection, the glomerular filtration rate fell significantly throughout the experimental period of three hr. Urine flow rate and renal blood flow also decreased and the filtered load of electrolytes declined significantly. The fractional excretion of sodium, potassium and phosphorus increased following venom administration. These data suggest that the venom may depress both glomerular and tubular functions. The renal autoregulation of blood flow was maintained during the experimental reduction of renal arterial pressure. We conclude that the ability of renal vasculature to autoregulate renal blood flow is not inhibited by Russell's viper venom, even though renal function is depressed.

Angiotensin II-induced depression of Purkinje cell firing and possible modulatory action on GABA responses

Effects of octapeptide angiotensin II (AII) were tested on cortical neurons of rat's cerebellum by means of microiontophoresis. It was observed that AII consistently depressed spontaneous firing of Purkinje cell, whereas other unidentified neurons were unaffected. When tested against responses of Purkinje cell to depressant putative neurotransmitters, namely, GABA, glycine, taurine, 5-hydroxytryptamine and noradrenaline, it was observed that AII specifically enhanced depressant action of GABA, while the responses to other substances were unaffected. Both AII-induced depression of cell firing and the AII-induced enhancement of GABA depression were antagonized by a specific GABA antagonist, bicuculline methochloride. We therefore suggest that AII exerts an inhibitory action on Purkinje cells through its modulatory action on bicuculline-sensitive GABA receptors.