[Developmental toxicity of Cry1Ab protein in the embryonic stem-cell model]

OBJECTIVE

To evaluate the developmental toxicity of Cry1Ab protein by studying its effects on cell proliferation and differentiation ability using a developmental toxicity assessment model based on embryonic stem-cell.

METHODS

Cry1Ab protein was tested in seven dose groups (31.25, 62.50, 125.00, 250.00, 320.00, 1 000.00, and 2 000.00 μg/L) on mouse embryonic stem cells D3 (ES-D3) and 3T3 mouse fibroblast cells, with 5-fluorouracil (5-FU) used as the positive control and phosphate buffer saline (PBS) as the solvent control. Cell viability was detected by CCK-8 assay to calculate the 50% inhibitory concentration (IC50) of the test substance for different cells. Additionally, Cry1Ab protein was tested in five dose groups (125.00, 250.00, 320.00, 1 000.00, and 2 000.00 μg/L) on ES-D3 cells, with PBS as the solvent control and 5-FU used for model validation. After cell treatment, cardiac differentiation was induced using the embryonic bodies (EBs) culture method. The growth of EBs was observed under a microscope, and their diameters on the third and fifth days were measured. The proportion of EBs differentiating into beating cardiomyocytes was recorded, and the 50% inhibition concentration of differentiation (ID50) was calculated. Based on a developmental toxicity discrimination function, the developmental toxicity of the test substances was classified. Furthermore, at the end of the culture period, mRNA expression levels of cardiac differentiation-related markers (Oct3/4, GATA-4, Nkx2.5, and β-MHC) were quantitatively detected using real-time quantitative polymerase chain reaction (qPCR) in the collected EBs samples.

RESULTS

The IC50 of 5-FU was determined as 46.37 μg/L in 3T3 cells and 32.67 μg/L in ES-D3 cells, while the ID50 in ES-D3 cells was 21.28 μg/L. According to the discrimination function results, 5-FU was classified as a strong embryotoxic substance. There were no statistically significant differences in cell viability between different concentrations of Cry1Ab protein treatment groups and the control group in both 3T3 cells and ES-D3 cells (P>0.05). Moreover, there were no statistically significant differences in the diameter of EBs on the third and fifth days, as well as their morphology, between the Cry1Ab protein treatment groups and the control group (P>0.05). The cardiac differentiation rate showed no statistically significant differences between different concentrations of Cry1Ab protein treatment groups and the control group (P>0.05). 5-FU significantly reduced the mRNA expression levels of β-MHC, Nkx2.5, and GATA-4 (P < 0.05), showing a dose-dependent trend (P < 0.05), while the mRNA expression levels of the pluripotency-associated marker Oct3/4 exhibited an increasing trend (P < 0.05). However, there were no statistically significant differences in the mRNA expression levels of mature cardiac marker β-MHC, early cardiac differentiation marker Nkx2.5 and GATA-4, and pluripotency-associated marker Oct3/4 between the Cry1Ab protein treatment groups and the control group (P>0.05).

CONCLUSION

No developmental toxicity of Cry1Ab protein at concentrations ranging from 31.25 to 2 000.00 μg/L was observed in this experimental model.

[Evaluation of gastric emptying after drinking carbohydrates before cesarean section by gastric ultrasonography]

OBJECTIVE

To investigate the effect of gastric antrum ultrasonography in evaluating gastric emptying after oral administration of 300 mL carbohydrates two hours before cesarean section, and to analyze the risk factors of gastric emptying in pregnant women.

METHODS

From August 2020 to February 2021, a total of 80 patients, aged 22-43 years, body mass index (BMI) < 35 kg/m2, gestational age≥36 weeks, falling into American Society of Anesthesiologists (ASA) physical status Ⅰ or Ⅱ, scheduled for cesarean sections in Peking University International Hospital were recruited and divided into two groups: the intervention group (n=40)and the control group (n=40). In the intervention group, solid food was restricted after 22:00, the patients were required to take 300 mL carbohydrates two hours before cesarean section. In the control group, solid food and liquid intake were restricted after 22:00 the night before surgery. All the patients received assessment of preoperative feeling of thirst and starvation with visual analogue scale (VAS). The cross-sectional area (CSA)of gastric antrum was measured in supine position and right supine position before anesthesia, the gastric volume (GV)and the gastric volume/weight(GV/W)of the two groups was further calculated. Perlas A semi-quantitative grading assessments were performed in each patient. The blood pressure and heart rate were recorded at admission(T0), 5 minutes after anesthesia (T1), immediately after fetal delivery (T2) and at the end of the surgery (T3). The occurrence of nausea and vomiting during the operation and 24 hours after the operation were recorded.

RESULTS

One case in each group was excluded because the antrum was not clearly identified during the ultrasound assessments. In the semi-sitting position, the CSA was (5.07±1.73) cm2 in the intervention group vs. (5.24±1.96) cm2 in the control group, respectively; in the right lateral decubitus position, CSA was (7.32±2.17) cm2 in the intervention group vs. (7.25±2.24) cm2 in the control group, GV was (91.74±32.34) mL vs. (90.07±31.68) mL, GV/W was (1.27±0.40) mL/kg vs. (1.22±0.41) mL/kg, respectively; all the above showed no significant difference between the two groups (P > 0.05). Perlas A semi-quantitative grading showed 0 in 20 patients (51.3%), 1 in 16 (41%), 2 in 3 (7.7%)in the intervention group and 0 in 22 (56.4%), 1 in 15 (38.5%), 2 in 2 (5.1%)in the control group, the proportion of Perlas A semi-quantitative grading showed no significant difference between the two groups (P > 0.05). For the patients with Perlas A semi-quantitative grade 2 (3 cases in the intervention group and 2 cases in the control group), metoclopramide 0.2 mg/kg was intravenously injected before anesthesia. No aspiration case was observed in this study. The intervention group was endured less thirst and hunger (P < 0.05). There was no significant difference in blood pressure and heart rate between the two groups at each time point (P > 0.05). There was no significant difference in the incidence of intraoperative hypotension between the two groups (P > 0.05). There was no significant difference in the incidence of nausea intraoperatively and postoperatively between the two groups (P > 0.05).

CONCLUSION

Ultrasonography of gastric antrum can provide objective basis for evaluating gastric emptying of pregnant women perioperatively. 300 mL carbohydrates intake two hours before surgery, which does not increase GV and the risk of reflux aspiration, and is helpful in minimizing disturbance to the patient's physiological status, therefore leading to better clinical outcome.

[Effects of the composite of buckwheat-oat-pea on blood glucose in diabetic rats]

OBJECTIVE

To study the effects of buckwheat-oat-pea (BOP) composite flour [buckwheat ∶ oats ∶ peas=6 ∶ 1 ∶ 1 (quality ratio)] on blood glucose in diabetic rats.

METHODS

In this study, 64 male Sprague-Dawley rats were divided into 8 groups by fasting blood glucose (FBG) and body weight: normal control group, model control group, metformin group, buckwheat group, oats group, BOP low-dose group (BOP-L), medium-dose group (BOP-M), and high-dose group (BOP-H). The rats in the normal control group were fed with normal diet, the rats in the model control group and metformin group were fed with a high-fat diet (HFD), and the rats in the buckwheat group, oats group, and BOP-L, BOP-M, BOP-H groups were fed with HFD containing 10% buckwheat flour, 10% oat flour, 3.3% BOP, 10% BOP, 30% BOP, respectively. The HFD in all the groups had the same percentage of energy from fat (45%). After 30 days, the rats fed with HFD received intraperitoneal injection of streptozotocin (30 mg/kg, once a week for two weeks) to establish diabetes mellitus. After the model was successful established, the rats were fed for another 28 days. During the study, the body weight, food intake/body weight (FI/BW) and water intake/body weight (WI/BW), food utilization rate, 24 h urine volume, FBG, glucose area under curve (GAUC) of oral glucose tolerance test were measured regularly. At the end of the study, the fasting serum glucose and insulin were measured, and homeostasis model assessment of insulin resistance (HOMA-IR) was calculated.

RESULTS

With the inducing of HFD and streptozotocin, compared with the normal control group, the rats in the model control group had higher FI/BW, WI/BW, 24 h urine volume, FBG, GAUC, HOMA-IR (P < 0.05), and lower body weight, food utilization rate (P < 0.05). Compared with the model control group, the rats in the three BOP groups all had higher body weight, food utilization rate (P < 0.05), and lower WI/BW, HOMA-IR (P < 0.05); the rats in the BOP-L and BOP-M groups had lower FI/BW, 24 h urine volume, FBG (P < 0.05), and the rats in the BOP-M group also had lower GAUC (P < 0.05). After the establishment of diabetes, there was no significant difference in blood glucose and the other indicators between the rats in the three BOP groups and the buckwheat group or the oats group (P>0.05).

CONCLUSION

The BOP had the effects of reducing blood glucose, insulin resistance and diabetic symptoms on diabetic rats, and had the value for further development and utilization.

[Analysis of related factors of postoperative complications of Juvenile-onset recurrent respiratory papillomatosis]

Objective:To analyze the causes and related factors of postoperative complications of Juvenile-onset recurrent respiratory papillomatosis（JORRP）. Methods:One hundred and seventy cases of JORRP who underwent surgical treatment in Beijing Tongren Hospital of Capital Medical University from 2017 to 2019 were followed up, and the types of complications, age of first operation, number and frequency of operations, and underwent tracheotomy or not were reviewed. According to the presence or absence of postoperative complications, the patients were divided into a complication group and a control group, and the differences between the two groups and related factors causing postoperative complications were compared. Results:In the 170 cases, 75（44.12%） had postoperative complications, including 52（69.33%） cases of vocal cord adhesion, 37（49.33%） cases of lower airway diffusion, and 25（33.33%） cases of laryngeal stenosis in the complication group. The age of first operation was among 0.3-14 years old, and the total number of surgeries was 14.52（1-54） for each patient during the observation period, with an average annual number of 2.93（0.04-18.39）. Compared with the control group, the complication group had 19.07±13.12 total surgeries, the control group had 10.97±9.41 surgeries（P<0.01）, annual surgeries ≥4 times（P=0.034）, postoperative complications after tracheotomy（P=0.007）, and underwent low temperature plasma radiofrequency ablation and photodynamic therapy were more likely to occur than those treated with CO2laser only（P<0.01）. Conclusion:The postoperative complications of JORRP include vocal cord adhesion, laryngotracheal stenosis, lower airway dissemination, etc. Multiple and frequent operations, tracheotomy, and different surgical methods are closely related to postoperative complications. The risk of postoperative complications may be increased when children are younger in age of initial operation and with more frequency of surgeries.

[Nutritional knowledge, attitudes and dietary behaviors of teachers and students in a medical college in Beijing and their influencing factors]

OBJECTIVE

To investigate nutritional knowledge, attitudes and dietary behaviors of teachers and students in a medical college in Beijing and their influencine factors, and to provide evidence for nutrition education and promotion.

METHODS

The subjects of this study were teachers, as well as first-year and second-year graduate students, and first-year to third-year undergraduate students. The teachers and students were respectively sampled by stratified cluster sampling with equal proportion. t-test or ANOVA was used to compare the means between the groups, and multiple linear regression was used to analyze the influencing factors of knowledge, attitude and practice (KAP) score.

RESULTS

The average score of nutrition knowledge was 5.7±1.5. The knowledge rate of nutrition was 57.3%. The average score of nutritional attitudes was 8.3±3.0. The mean nutritional behavior score was 5.1±2.0. The average nutritional KAP score was 19.1±4.6, with the teachers 19.9±5.2 higher than the students 18.9±4.5; the female 19.5±4.5 higher than the male 18.4±4.5; All the differences were statistically significant (P < 0.05). The scores of nutritional attitudes, nutritional behavior and total KAP scores of doctoral students were significantly higher than those of the undergraduate and postgraduate students (P < 0.01).

CONCLUSION

The nutrition attitudes of teachers and students is relatively correct, the nutrition knowledge needs to be further strengthened, and there are some unreasonable aspects in the nutrition behaviors. Gender, identity and degree are the main influencing factors of the nutrition score of knowledge, attitudes and behaviors. It is necessary to carry out nutritional education in schools to improve the nutrition knowledge of teachers and students, correct bad eating habits, and promote the construction of healthy China action.

[Nutritional knowledge, attitudes and dietary behaviors of teachers and students in a medical college in Beijing and their influencing factors]

OBJECTIVE

To investigate nutritional knowledge, attitudes and dietary behaviors of teachers and students in a medical college in Beijing and their influencine factors, and to provide evidence for nutrition education and promotion.

METHODS

The subjects of this study were teachers, as well as first-year and second-year graduate students, and first-year to third-year undergraduate students. The teachers and students were respectively sampled by stratified cluster sampling with equal proportion. t-test or ANOVA was used to compare the means between the groups, and multiple linear regression was used to analyze the influencing factors of knowledge, attitude and practice (KAP) score.

RESULTS

The average score of nutrition knowledge was 5.7±1.5. The knowledge rate of nutrition was 57.3%. The average score of nutritional attitudes was 8.3±3.0. The mean nutritional behavior score was 5.1±2.0. The average nutritional KAP score was 19.1±4.6, with the teachers 19.9±5.2 higher than the students 18.9±4.5; the female 19.5±4.5 higher than the male 18.4±4.5; All the differences were statistically significant (P < 0.05). The scores of nutritional attitudes, nutritional behavior and total KAP scores of doctoral students were significantly higher than those of the undergraduate and postgraduate students (P < 0.01).

CONCLUSION

The nutrition attitudes of teachers and students is relatively correct, the nutrition knowledge needs to be further strengthened, and there are some unreasonable aspects in the nutrition behaviors. Gender, identity and degree are the main influencing factors of the nutrition score of knowledge, attitudes and behaviors. It is necessary to carry out nutritional education in schools to improve the nutrition knowledge of teachers and students, correct bad eating habits, and promote the construction of healthy China action.

[Long-term effectiveness of vascularized fibula flap in radiocarpal joint reconstruction following excision of Campanacci grade giant cell tumor]

OBJECTIVE

To evaluate the long-term effectiveness of vascularized fibula flap in radiocarpal joint reconstruction following excision of Campanacci grade Ⅲ giant cell tumor (GCT) of distal radius.

METHODS

Between December 2010 and December 2014, 10 patients with Campanacci grade Ⅲ GCT of distal radius were treated with en bloc excision and inradiocarpal joint reconstruction using vascularized fibula flap. They were 6 males and 4 females, with an average age of 39.9 years (range, 22-65 years). The disease duration was 1.5-6.0 months (mean, 2.6 months). The length of distal radius defect was 6.0-12.5 cm (mean, 8.4 cm) after en bloc excision of GCT. Vascularized fibula flap with inferior lateral genicular vessels were performed in 6 patients and with inferior lateral genicular vessels and peroneal vessels in 4 cases.

RESULTS

All incisions healed by first intention. All patients were followed up 4.4-8.3 years (mean, 6.0 years). There was no tumor recurrence during follow-up. At last follow-up, the mean ranges of motion of wrist joint were 55.0° (range, 25-85°) in extension, 26.5° (range, 15-40°) in flexion, 12.0° (range, 5-25°) in radial deviation, 19.6° (range, 10-30°) in ulnar deviation, 50.5° (range, 5-90°) in pronation, and 66.5° (range, 20-90°) in supination. The mean grip strength of effected wrist was 75% (range, 60%-85%) of the healthy wrist. The mean Musculoskeletal Tumor Society (MSTS) score was 82.7% (range, 75%-90%). X-ray films showed that the fibula flap healed at 12-16 weeks after operation (mean, 14.1 weeks) and there were 9 cases of radiological complications.

CONCLUSION

For Campanacci grade Ⅲ GCT of distal radius, application of the vascularized fibula flap in radiocarpal joint reconstruction after en bloc excision of GCT can obtain good wrist function.