Objective: Identification of the genes specially expressed in tumor cell but not in normal cell is important for understanding the molecular mechanisms of carcinogencsis. This study will focus on identification of differentially expressed gene fragments in human stomach cancer. Methods: By using the new developing mRNA differential display (DD) technique, genes fragments differentially expressed in stomach cancer tissues from a patient and the adjacent normal tissues beyond the tumor mass were studied. Results: Two differentially displayed complementary DNA fragments from stomach cancer tissues, scgl and scg2 (stomach cancer-associated gene, scg), cofirmed by Northern Blot, were cloned and sequenced. The nucleotide length of scgl is 194 base pairs and that of scg2 is 343 base pairs. After searching against GenBank databases by BLASTN, neither scgl nor scg2 had significant homological gene sequences with the known genes. Conclusion: These results suggested scgl and scg2 might be complementary DNA fragments of novel genes expressed in stomach cancer tissues, but not in normal tissues and may play a role in the occurrence and development of stomach cancer. Further characterization of full-length of these two complementary DNA fragments will be continued.

Objective To investigate the clinical efficacy of endoscopic surgery for extensive osteoradionecrosis (ORN) of skull base in patients with nasopharyngeal carcinoma (NPC) after radiotherapy.Methods Seventeen patients diagnosed as ORN of skull base after radiotherapy for NPC and underwent endoscopic surgery were retrospectively studied with their clinic data.Results Based on the CT and endoscopic examination,all patients had large skull base defects with bone defects averaged 7.02 cm2 (range,3.60-14.19 cm2).Excepting for curetting the sequestra,endoscopic surgery was also used to repair the wound or to protect the internal carotid artery with flap in 12 patients.No bone reconstructions were conducted in all patients with the bone defects of skull base.CT examinations were taken after endoscopic surgery when required.The postoperative follow-up ranged from 8 months to 6 years (average,14 months).Aside from 1 patient with delayed cerebrospinal fluid (CSF),others had no related complications.Conclusions The patients with extensive ORN can be treated with endoscopic surgery to curette the necrotic bone of skull base,and endoscopic reconstruction provides an alternative technique.It may not be necessary to reconstruct the bone defects at skull base,however,the exposed important structures of skull base,such as internal carotid artery,need to repair with soft tissue such as flap.