Neural stem/progenitor cells transit from fibroblast growth factor-responsive to epidermal growth factor (EGF)-responsive stem cells in the subventricular zone (SVZ). Here, we provide evidences that Pax6 plays a crucial role in the regulation of the EGF-responsive stem cell pool of the SVZ. Using Pax6 homozygous mutant mice (E18.5d), we found that the neurospheres were formed less than that from the wild-type mice, and the expression of EGF receptor in these neurospheres is downregulated very much. The amount of EGF-responsive cells in the mutant dorsal cortex SVZ (E18.5d) was also decreased from 16.8 (wild) to 4.5% (mutant), by flow cytometry method. Immunostaining of the cortex showed a downregulation of EGF receptor expression. All these results suggest that Pax6 regulate the EGF-responsive stem cells in the SVZ.

Intraoperative ingestion of blood, cerebrospinal fluid, and irrigation fluid can lead to an increase in gastric volume, resulting in the potential risk of aspiration in patients after endoscopic endonasal transsphenoidal surgery (EETS). In this prospective observational study, we aimed to assess the volume of gastric contents in patients undergoing this neurosurgical procedure using ultrasound, and to determine the factors associated with volume change. Eighty-two patients diagnosed with pituitary adenoma were recruited consecutively. Semi-quantitative (Perlas scores: 0, 1 and 2) and quantitative (cross-sectional area, CSA) ultrasound assessments of the gastric antrum were performed immediately before and after surgery in the semi-recumbent and semi-recumbent right-lateral positions. Seven (8.5%) patients had antrum scores from preoperative grade 0 to postoperative grade 2; nine (11%) patients had antrum scores from preoperative grade 0 to postoperative grade 1. The mean ± standard deviation (SD) of increased gastric volume was 71.0 ± 33.1 mL and 236.5 ± 32.4 mL in postoperative grade 1 and 2 groups, respectively. Subgroup analysis showed that 11 (13.4%) patients (4 in grade 1 and all in grade 2) had postoperative estimated gastric volume > 1.5 mL kg−1 (mean ± SD 3.08 ± 1.67, range 1.51–5.01 mL kg−1). Logistic regression analysis revealed that older age, diabetes mellitus, and long surgical duration were independent risk factors for significant volume change (all P < 0.05). Our results showed a significant increase in gastric volume in some patients who underwent EETS. Bedside ultrasound measurements of gastric volume can be used to assess the postoperative aspiration risk, particularly in older diabetic patients with a longer surgical duration.

Surgical procedures may affect the changes in gastric contents and volume, resulting in a potential risk of pulmonary aspiration. We aimed to assess the differences in preoperative and postoperative gastric contents and volume in patients undergoing endoscopic endonasal transsphenoidal surgery using ultrasound and determine the potential factors associated with intraoperative volume changes. This prospective study enrolled 71 adult patients diagnosed with pituitary adenoma. Semi-quantitative (Perlas score: grade 0, 1, or 2) and quantitative (cross-sectional area, CSA) ultrasound scans of the gastric antrum were performed before anaesthetic induction and postoperatively in semirecumbent and semirecumbent-right lateral positions. The postoperative median (interquartile [range]) antral CSA in both positions were 3.5 cm2 (3.3–3.7 [2.9–12.1]) and 3.7 cm2 (3.4–4.6 [2.9–26.6]), significantly higher than the preoperative values of 3.3 cm2 (3.1–3.4 [2.7–3.9]) and 3.4 cm2 (3.2–3.7 [2.8–5.7]), respectively (P=0.001). The postoperative estimated gastric volume was 20.2 ml (2.2–42.7 [0–316.7]), significantly larger than the preoperative value of 14.5 ml (0–32.6 [0–66.4]) (P=0.001). Seven (9.9%) patients showed significant volume changes, from preoperative grade 0 to postoperative grade 2 (estimated volume >1.5 ml.kg-1) (P=0.02). Logistic regression analysis revealed that gastroesophageal reflux, intraoperative irrigation volume, and anaesthesia duration were independent risk factors for significant intraoperative volume changes (P<0.05). Our results show that significant change in gastric volume was presented in some patients during transsphenoidal surgery because of the special surgical procedures and comorbidities. Perioperative ultrasound could facilitate assessing aspiration risk in patients undergoing transsphenoidal neurosurgical procedures.Trial registration: This prospective observational study was registered at http://www.chictr.org.cn (ChiCTR2100045110) on 7 April 2021.

Surgical procedures may affect the changes in gastric contents and volume, resulting in a potential risk of pulmonary aspiration. We aimed to assess the differences in preoperative and postoperative gastric contents and volume in patients undergoing endoscopic endonasal transsphenoidal surgery using ultrasound and determine the potential factors associated with intraoperative volume changes. This prospective study enrolled 71 adult patients diagnosed with pituitary adenoma. Semi-quantitative (Perlas score: grade 0, 1, or 2) and quantitative (cross-sectional area, CSA) ultrasound scans of the gastric antrum were performed before anaesthetic induction and postoperatively in semirecumbent and semirecumbent-right lateral positions. The postoperative median (interquartile [range]) antral CSA in both positions were 3.5 cm2 (3.3–3.7 [2.9–12.1]) and 3.7 cm2 (3.4–4.6 [2.9–26.6]), significantly higher than the preoperative values of 3.3 cm2 (3.1–3.4 [2.7–3.9]) and 3.4 cm2 (3.2–3.7 [2.8–5.7]), respectively (P = 0.001). The postoperative estimated gastric volume was 20.2 ml (2.2–42.7 [0–316.7]), significantly larger than the preoperative value of 14.5 ml (0–32.6 [0–66.4]) (P = 0.001). Seven (9.9%) patients showed significant volume changes, from preoperative grade 0 to postoperative grade 2 (estimated volume > 1.5 ml.kg− 1) (P = 0.02). Logistic regression analysis revealed that gastroesophageal reflux, intraoperative irrigation volume, and anaesthesia duration were independent risk factors for significant intraoperative volume changes (P<0.05). Our results show that significant change in gastric volume was presented in some patients because of the special surgical procedures and comorbidities. Anesthesiologists could use antral ultrasonography to prevent this potential risk of aspiration in patients after transsphenoidal procedures.

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