HBV整合的致癌性研究

HBV的4个亚基因产物中,HBx具有反式激活、介导细胞凋亡作用,HBs具有反式激活因子的作用。肝细胞癌(HCC)的发生与HBV的整合及整合后染色体重排有关。为探讨HBV整合及HBx、HBs亚基因在HCC发生中的可能作用,我们制备了HBV亚基因探针,并以此对肝细胞癌中HBV整合及亚基因转录进行了研究,以期为阐明HBV感染后HCC发生机制提供一定的实验资料和依据。本研究中,首先以BamHⅠ、BglⅡ酶切扩增回收的HBVDNA ,回收其HBV亚基因HBx、HBc、HBs、PreSDNA片段,以地高辛甙元随机引物法标记成敏感性与特异性俱佳的HBV亚基因探针,再以HBV探针点杂交检测HCC标本中HBVDNA的阳性率,对阳性的标本,继以Southern转膜杂交检测其整合情况,最后取HBVDNA阳性的HCC标本,按经典方法抽提其mRNA ,分别以HBV亚基因探针Northern转膜杂交检测亚基因的表达率。结果显示:4 4例HCC标本中,75 %的标本显示有HBVDNA的存在;Southern杂交分析,HBV纯整合型HCC为6 3.6 % ,混合型HCC为36 .4 % ,未见单纯游离型HCC标本存在;17例HBVDNA阳性..

Surgical management of pharyngoesophageal tumours

Pharyngoesophageal (PE) tumours are tumours involving simultaneously the hypopharynx and the cervical oesophagus. The challenge in its surgical management lies in its deep-seated location behind the manubrium bone in the cervicothoracic region, in close proximity to great vessels in the lower neck and superior mediastinum. Classically curative surgery is in the form of total pharyngo-laryngo-oesophagectomy (PLO) and gastric pull-up (GPU) via a three-phase one-stage operation. However PLO and GPU is a major undertaking associated with high operative morbidity and reported in-hospital mortality rates of up to 10%. With a comprehensive preoperative work-up we demonstrated accurate tumour diagnosis and staging, with a 100% negative predictive rate. Together with vigilant postoperative surveillance and compliant follow-up, incidence of synchronous and metachronous tumours were low at 11.9% and 1.7% respectively. Manubrial resection (MR) provided access to PE tumours in the cervicothoracic region enabling resection under direct vision with adequate resection margins - pharyngo-laryngo-cervico-oesophagectomy (PLCO). The trachea was resected and re-sited as a mediastinal tracheostoma in case of posterior tracheal wall invasion. Paratracheal and paraoesophageal lymph node dissection was performed in case of nodal metastasis. MR provided ample space for reconstruction of the resultant defect. Furthermore, it enabled access to vessels in the superior mediastinum to support microvascular tissue transfer. Intra-thoracic volume changes on maximal inspiration and expiration measured using computed tomography scan did not show significant difference pre- and post- MR. With attention to operative details, MR proved to be safe with minimal functional disturbance. Free jejunal (FJ) flap was the preferred reconstructive modality as it offered the lowest pharyngocutaneous fistula and anastomotic stricture rates, and donor site morbidities. All patients resumed unrestricted oral diet postoperation. Videofluoroscopic swallowing studies (VFSS) and high resolution manometry (HRM) demonstrated significantly prolonged transit times for all bolus consistencies compared with normal subjects due to asynchronous contractions between the FJ and the oesophageal remnant, presence of retrograde propulsion and residue accumulation within the FJ. However, patients reported significant improvement in swallowing outcomes and associated quality of life (QOL) compared with preoperation (65.3% vs. 42.7%, p=0.02). Majority of patients were able to speak conveniently with a modality of their choice. MR, PLCO and FJ flap showed significantly lower operative morbidities (58.3% vs. 85.7%, p=0.05), shorter hospital stay (42.5 vs. 50.7 days, p=0.37), and lower in-hospital mortality (8.3% vs. 9.5%, p=0.52) compared with PLO and GPU. None required intensive care unit postoperation. In resecting less, oncological outcomes and survival were not inferior to PLO and GPU. FJ patients were able to resume oral diet sooner than GPU with a higher functional oral intake scale (FOIS) at 6 months (100.0% vs. 92.8%). Shorter transit times for all bolus consistencies were demonstrated in VFSS and HRM of GPU patients due to the lack of contractions within the gastric tube. Swallowing, speech and associated QOL outcomes were comparable between the 2 groups. In conclusion, MR, PLCO and FJ flap should be adopted in the surgical management of patients with isolated PE tumours.published_or_final_versionSurgeryMasterMaster of Surger