Ketamine inhibits proliferation of neural stem cell from neonatal rat hippocampus in vitro.

BACKGROUND/AIMS: Ketamine is a widely used anesthetic in obstetric and pediatric anesthesia. In the developing brain, the widespread neuron apoptosis triggered by ketamine has been demonstrated. However, little is known about its effect on neural stem cells (NSCs) function. This study aimed to investigate the effect of ketamine on proliferation of NSCs from neonatal rat hippocampus. METHODS: Neural stem cells were isolated from the hippocampus of Sprague-Dawley rats on postnatal day 3. In dose-response experiments, cultured neural stem cells (NSCs) were exposed to different concentrations of ketamine (0-1000 µM) for 24 hrs. The proliferative activity of NSCs was evaluated by 5-Bromo-2'-deoxyuridine (BrdU) incorporation assay. Apoptosis of neural stem cells were assessed using caspase-3 by western blot. The intracellular Ca(2+) concentration ([Ca(2+)]i) in NSCs was analyzed by flow cytometry. The activation of protein kinase C-α (PKCα) and the phosphorylation of extracellular signal-regulated kinases 1/2 (ERK1/2) were measured by western blot analysis. RESULTS: Clinical relevant concentration of ketamine (10, 20 and 50 µM) did not markedly alter the proliferation of NSCs from neonatal rat hippocampus in vitro. However, ketamine (200, 500, 800 and 1000µM) significantly inhibited the proliferation of NSCs and did not affect the expression of caspase-3. Meanwhile, ketamine (200, 500, 800 and 1000µM) also markedly decreased [Ca(2+)]i as well as suppressed PKCα activation and ERK1/2 phosphorylation in NSCs. A combination of subthreshold concentrations of ketamine (100 µM) and Ca(2+) channel blocker verapamil (2.5 µM), PKCα inhibitor chelerythrine (2.5 µM) or ERK1/2 kinase inhibitor PD98059 (5 µM) significantly produced suprathreshold effects on PKCα activation, ERK1/2 phosphorylation and NSC proliferation. CONCLUSION: Ketamine inhibited proliferation of NSCs from neonatal rat hippocampus in vitro. Suppressing Ca(2+)-PKCα-ERK1/2 signaling pathway may be involved in this inhibitory effect of ketamine on NSCs proliferation.

[Clinical features and management of pyothorax due to postoperative cervical anastomotic leakage in esophageal cancer surgery].

OBJECTIVE: To investigate the clinical characteristics and managements of pyothorax due to postoperative cervical anastomotic leakage after esophageal cancer surgery. METHODS: From January 2006 to January 2013, 3342 patients with esophageal carcinoma underwent esophagectomy and cervical esophagogastric anastomosis. Of them, 19 patients developed pyothorax following cervical anastomotic leakage and their clinicopathological data were analyzed retrospectively. RESULTS: All the patients underwent a cervical anastomosis via a three-incisional approach (right cervicothoracic mid-abdominal incision, RT group, n=1094) or a two-incisional approach (left cervicothoracic incision, LT group, n=2248). The total number of cervical anastomotic leakage cases was 237, of which 152 cases were in LT group (6.8%), and 85 cases in RT group (7.8%), respectively (P=0.287). The incidence of pyothorax was 2.0% (n=3) in LT group, and 18.8% (n=16) in RT group, respectively (P<0.01). Fourteen cases develop pyothorax within 3 days after operation. The main symptoms were high fever, dyspnea and chest pain. All the pyothorax patients received conservative treatments, including thoracic closed drainage, nasogastric tube placement, jejunal stoma, nutritional support, antibiotics and symptomatic treatment. Sixteen cases were cured, while 3 cases were dead. CONCLUSIONS: The right thoracotomy approach predisposes the cervical anastomotic leakage-associated pyothorax. Sufficient drainage and sufficient nutritional support are critical to the treatment.

[Gene expression profiling study of HPV-16 positive and HPV-negative esophageal squamous cell carcinoma].

OBJECTIVE: To study the difference in gene expression between human papillomavirus (HPV)16-positive and HPV-negative esophageal squamous cell carcinoma(ESCC) . METHODS: Eight HPV 16-positive and seven HPV-negative ESCC specimens were evaluated by PCR. The samples were then determined for gene expression profiling using Solexa Sequencing Chip followed by bioinformatics analysis. RESULTS: A total of 796 differentially expressed genes between HPV 16-positive and HPV-negative ESCC were observed. Among them, 366 were up-regulated while 430 were down-regulated. Functional classification and pathway analysis showed that the functions of these genes were mostly related to tumor morphology, immune, and inflammatory response, cellular growth and proliferation and cellular movement. Of these, factors related to immune and inflammation were the most representative. CONCLUSION: Differences in immunologic factors may be associated with HPV infection in esophageal cancer.

Matrix metalloproteinases expression correlates with survival in patients with esophageal squamous cell carcinoma.

OBJECTIVES: The matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases capable of degrading the extracellular matrix and play important roles in malignancies. We evaluated the expression of four MMPs in esophageal squamous cell carcinoma (ESCC), and assessed the association between MMP expression and clinicopathologic characteristics and disease-free survival time. METHODS: We evaluated MMP1, MMP7, MMP9, and MMP13 expression in tissues from 208 patients with ESCC using immunohistochemistry (IHC), and correlated MMP expression to clinicopathologic characteristics and disease-free survival time. To confirm MMP9 expression at different levels, we simultaneously performed RT-PCR, Western blotting, and IHC on tissues from a separate cohort of 23 patients with ESCC. RESULTS: IHC analysis showed that 63.0%, 41.8%, 49.0%, and 32.2% of 208 ESCC samples were positive for MMP1, MMP7, MMP9, and MMP13, respectively. MMPs were strongly expressed in the cytoplasm of cancer cells, especially in the invasive margin, and weakly expressed in stromal cells. No immunostaining was detected in non-cancerous esophageal mucosa. MMP9 expression was positively associated with poor tumor cell differentiation (p= 0.001), vessel permeation (p= 0.027), and lymph node metastasis (p= 0.027). MMP9 expression was a negative, independent predictor of disease-free survival time (Hazard ratio, 1.470; 95% CI, 1.105 approximately 1.955; p= 0.008). The expression of MMP7 (median survival time: 23 months for MMP7 positive patients, >77 months for MMP7 negative patients; p= 0.001) and MMP13 (median survival time: 18 months for MMP13 positive patients, 39 months for MMP13 negative patients; p= 0.014) correlated negatively with disease-free survival in relatively early stage ESCC patients. Co-expression of MMP7, MMP9, and MMP13 in relatively early stage ESCC samples identified patients with a poor prognosis (13 months median survival time) compared to those lacking MMP7, MMP9, and MMP13 expression (58 months median survival time, p < 0.001). CONCLUSIONS: MMP9 expression is a negative, independent prognostic factor in ESCC and correlates with tumor cell differentiation, vessel permeation, and lymph node metastasis. MMP7, MMP9, and MMP13 may function in early stage ESCC, and their co-expression predicts poor outcome for relatively early stage ESCC patients.

Expression of 11 HOX genes is deregulated in esophageal squamous cell carcinoma.

PURPOSE: HOX genes are vital for all aspects of mammalian growth and differentiation, and recent data have shown that their deregulated expression is related to carcinogenesis. To date, there has been no systemic study on expression of HOX genes in esophageal carcinoma. We investigated the expression pattern of 39 known HOX genes in cancerous and noncancerous tissue from 36 patients with esophageal squamous cell carcinoma to determine whether their expression is altered in esophageal cancer. EXPERIMENTAL DESIGN: Thirty-six patients with resectable esophageal squamous cell carcinoma (ESCC) were enrolled in this study. Specific primers were designed for each of 39 HOX genes, and reverse transcription-PCR was done in cancerous and noncancerous samples of these 36 patients. Furthermore, the expression of HOXA9 protein was subjected to Western blot analysis in all 36 paired tissue samples. RESULTS: Eight of 39 HOX genes were expressed in cancerous but not in noncancerous tissue. Five of 39 HOX genes were expressed both in cancerous and noncancerous tissue. Of the latter, expression of HOXA7, HOXA9, and HOXC6 was significantly higher in cancerous tissue (P < 0.05). The remaining 26 HOX genes were not detected in either types of tissue. HOXA9 protein was expressed in both kinds of tissue (cancer tissue versus noncancerous mucosa: 0.34 +/- 0.32 versus 0.24 +/- 0.27, P = 0.121). CONCLUSIONS: This is the first comprehensive survey of 39 HOX gene expression in ESCC and noncancerous mucosa. Five of the 39 HOX genes were expressed in both types of tissue indicating their possible role in maintaining normal structure and function of adult esophageal mucosa. Eleven of the 39 HOX genes were deregulated in cancer tissue. These genes possibly participate in the carcinogenesis of ESCC.

Congenital expression of mdr-1 gene in tissues of carcinoma and its relation with pathomorphology and prognosis.

AIM:To detect the congenital expression patterns of mdr-1 gene in commonly encountered malignant tumors in clinic, and the relationship between the expression of mdr-1 gene and the prognostic morphology in esophageal carcinomas.METHODS:A total of 151 resected samples of malignant tumors without preoperative treatment were taken from Anyang City Tumor Hospital.The congenital expression of their mdr-1 gene was detected with reverse transcription polymerase chain reaction (RT-PCR) and was compared with each other.The positive incidence of mdr-1 gene in 46 samples of esophageal carcinoma was compared with their differentiated grades, TNM stages and macroscopic types, and the precautions and advantages of RT-PCR were evaluated.RESULTS:All the 151 samples were confirmed to be malignant histopathologically, including cancers of stomach and gastric cardia (n = 51), esophagus (n = 46), colorectum (n = 16),breast (n = 15), thyroid (n = 10), lung (n = 9) and uterine cervix (n = 24). The positive expression rate of their mdr-1 gene was 33.3%, 37%, 31.3%, 13.2%, 40%, 55%, and 0% respectively. All the 46 samples of esophageal carcinoma were pathologically confirmed to be squamous cell carcinoma. The total expression rate of their mdr-1 gene was 37% (17/46), 35% (6/17), 40% (8/20), and 33% (3/9) for differentiation grade I, II and III respectively. The expression rate of TNM classification was 33% (6/18), 40% (5/12) and 37% (6/16) in stage IIa, IIb andIII. The expression rate was 33% (3/9) in ulcerous type, 37% (3/8) in constrictive types, 33% (5/15) in fungoid types, and 40% (6/14) in medullary types.No statistically significant difference was found.CONCLUSION:Compared with other methods, RT-PCR is more simple, reliable and accurate in detecting mdr-1 gene expression in tissues of tumor. The overexpression of mdr-1 gene in these neoplasms suggested that cases should be handled differently for chemotherapy with rational use of drugs. Excision is the chief treatment for carcinoma of esophagus. The expression of mdr-1 gene in tissues of esophageal cancer is correlated with the parameters of tumor molecular biology which are independent of histopathological morphology.