幽门螺杆菌感染在胃癌发病中的作用研究

幽门螺杆菌(helicobacter pylori,Hp)感染是目前已知的最常见且作用力最强的胃癌危险因素之一,其感染率在世界范围内存在差异,种族、饮食习惯、年龄等均会对其造成影响。Hp借助自身脲酶、鞭毛、粘附素等因子定植于宿主,并通过Ⅳ型分泌系统(T4SS)、机体自噬系统以及毒力因子破坏,共同诱导机体产生胃炎、胃溃疡、胃癌等疾病。相关研究数据显示,约75%的胃癌是由Hp感染引起的炎症和损伤所致,但具体调节机制尚不明确。本文中,笔者将Hp感染在胃癌发病中的作用研究予以综述,以期为胃癌发生机制的进一步深入研究提供思路和帮助。     

幽门螺杆菌与慢性胃炎的相关性分析

幽门螺杆菌(Helicobacter pylori,Hp)在胃炎、消化性溃疡、胃癌等疾病中起着相当重要的作用,从慢性胃炎发病到胃癌的发生,它们之间的相关性是当前研究的热点;感染Hp后胃粘膜病变的发生和变化一直为国内外学者所关注。我们对1996～2000年经胃镜检出的559例慢性胃炎进行分析,并取粘膜组织活检,以研究幽门螺杆菌(Hp)与慢性胃炎不同的病理类型的相关性,并分析其特点如下:     

表观遗传调控对幽门螺杆菌阳性胃癌致病作用的研究进展

幽门螺杆菌(Hp)是一种常见的致癌因素,与胃癌的发病密切相关。幽门螺杆菌通过多种机制影响宿主基因的表达,包括表观遗传调控。随着对表观遗传学的深入研究,它与Hp阳性胃癌之间相互作用的证据也逐渐增多,靶向表观遗传学的改变有望成为Hp阳性胃癌的一种治疗策略。因此,该文对表观遗传调控在Hp阳性胃癌致病机制的影响及相互作用作一简要综述。     

幽门螺杆菌感染、RUNX3甲基化与胃癌血管生成及淋巴结转移的研究进展

幽门螺杆菌(Hp)感染与胃癌的发生、发展密切相关,已被世界卫生组织列为I类致癌原。RUNX3是近年来新发现的一种抑癌基因,参与多种癌症的发生、发展,其与胃癌的关系尤为近年来的研究热点,众多研究表明RUNX3甲基化与胃癌的发生有关,认为RUNX3是胃癌发生的早期事件,但对进展期胃癌的研究较少,本文就Hp感染、RUNX3甲基化与胃癌血管生成及淋巴结转移作一综述。     

驻高原官兵幽门螺杆菌感染与非酒精性脂肪性肝病研究进展

由于高原地区特殊的地理环境及气候变化,驻高原部队官兵成为幽门螺杆菌(Hp)的易感人群,Hp感染相关性疾病的发病率也相应增加,其中非酒精性脂肪性肝病(NAFLD)的发生发展与缺氧及Hp感染密切相关,根除Hp对降低高原地区部队官兵NAFLD的发病率具有重要作用。该文综述了高原地区官兵Hp感染的现状及其与NAFLD发病的相关性,重点分析了高原缺氧在官兵Hp感染及NAFLD发生、发展中的作用机制。     

Hp培养滤液诱导下抑制hTERT基因对SGC7901细胞bcl-2蛋白表达的影响

目的:探讨bcl-2表达与端粒酶活性二者之间的调控关系,了解Hp的致癌机制。方法:在Hp培养滤液诱导前后,采用流式细胞仪检测抑制hTERT基因之后SGC7901胃癌细胞bcl-2蛋白的表达。结果:对照组SGC7901胃癌细胞24 h、36 h和48 h表达bcl-2蛋白的阳性细胞率和荧光指数显著低于经Hp培养滤液诱导的SGC7901胃癌细胞组(P<0.05)。在Hp滤液诱导下,抑制hTERT基因的SGC791胃癌细胞24 h、36 h和48 h表达bcl-2蛋白的阳性细胞率和荧光指数与SGC7901胃癌细胞无显著差异(P>0.05)。结论:Hp感染可以促进bcl-2蛋白表达,这可能是Hp感染致胃癌的重要机制之一。端粒酶活化不参与调控bcl-2蛋白表达。     

幽门螺杆菌的研究进展

自1983年Warren.Marshall首先从胃炎病人胃内分离出幽门螺杆菌(Helicobacter pylori,Hp)后,各国学者经过广泛深入的研究发现Hp与慢性活动性胃炎、胃十二指肠溃疡、胄粘膜相关性淋巴瘤(MALT)及胃癌的发病有密切关系,1994年国际癌症研究中心将其归为I类致癌因子[1]。虽其具体机制     

Hp培养滤液诱导下抑制hTERT基因对SGC27901细胞bcl-2蛋白表达的影响

目的：探讨bcl-2表达与端粒酶活性二者之间的调控关系，了解Hp的致癌机制。方法：在Hp培养滤液诱导前后，采用流式细胞仪检测抑制hTERT基因之后SGC7901胃癌细胞bcl-2蛋白的表达。结果：对照组SGC7901胃癌细胞24h、36h和48h表达bcl-2蛋白的阳性细胞率和荧光指数显著低于经Hp培养滤液诱导的SGC7901胃癌细胞组（P〈0．05）。在Hp滤液诱导下，抑制hTERT基因的SGC791胃癌细胞24h、36h和48h表达bcl-2蛋白的阳性细胞率和荧光指数与SGC7901胃癌细胞无显著差异（P〉0．05）。结论：Hp感染可以促进bcl-2蛋白表达，这可能是Hp感染致胃癌的重要机制之一。端粒酶活化不参与调控bcl-2蛋白表达。     

幽门螺杆菌耐药机制的研究进展

幽门螺杆菌(Hp)寄生在人类胃黏膜,与胃十二指肠溃疡、慢性活动性胃炎、胃淋巴瘤及胃癌的发生、发展密切相关。世界上超过半数的人感染了Hp,但是临床治疗上对Hp根除率却不高,首次治疗根除率仅约70%,主要原因是患者对药物的依从性差和日益突出的抗生素耐药问题,本文就有关Hp对抗生素耐药机制的研究近况进行了综述。     

青海高原地区三个民族胃炎性病变及胃癌与Hp关系的分析

目的：分析幽门螺杆菌（Helicobacter Pylori,Hp）在青海高原地区回、藏、汉三个民族的感染状况以及与胃癌及各种胃炎性病变之间的关系分析。方法：分析我院连续10年内回、藏、汉三个民族被病理证实为胃癌及炎性病变的病理组织检查结果及Hp的感染状况。结果：Hp总阳性率为49.2%;回族54.8%,藏族49.8%,汉族44.5%,三者之间比较有非常显著性差异。各种炎性病变与胃癌之间的Hp阳性率比较有非常显著性差异。结论：Hp感染与民族、经济文化、饮食卫生等综合因素密切相关。Hp是慢性胃炎的重要致病因素,它与慢性炎症的程度以及肠化生和不典型增生等癌前病变的发生密切相关。     

CT Arthrography and Virtual Arthroscopy in the Diagnosis of the Anterior Cruciate Ligament and Meniscal Abnormalities of the Knee Joint

Objective

To determine the diagnostic accuracy of CT arthrography and virtual arthroscopy in the diagnosis of anterior cruciate ligament and meniscus pathology.

Materials and Methods

Thirty-eight consecutive patients who underwent CT arthrography and arthroscopy of the knee were included in this study. The ages of the patients ranged from 19 to 52 years and all of the patients were male. Sagittal, coronal, transverse and oblique coronal multiplanar reconstruction images were reformatted from CT arthrography. Virtual arthroscopy was performed from 6 standard views using a volume rendering technique. Three radiologists analyzed the MPR images and two orthopedic surgeons analyzed the virtual arthroscopic images.

Results

The sensitivity and specificity of CT arthrography for the diagnosis of anterior cruciate ligament abnormalities were 87.5%-100% and 93.3-96.7%, respectively, and those for meniscus abnormalities were 91.7%-100% and 98.1%, respectively. The sensitivity and specificity of virtual arthroscopy for the diagnosis of anterior cruciate ligament abnormalities were 87.5% and 83.3-90%, respectively, and those for meniscus abnormalities were 83.3%-87.5% and 96.1-98.1%, respectively.

Conclusion

CT arthrography and virtual arthroscopy showed good diagnostic accuracy for anterior cruciate ligament and meniscal abnormalities.     

CT and US of the pancreas

The diagnostic capabilities of pancreatic imaging continue to improve with technological advancements in computed tomography (CT), ultrasound (US), and magnetic resonance imaging (MRI). To update the practicing radiologist, this article summarizes the current literature on pancreatic imaging, with particular emphasis on CT and US. Pertinent clinical considerations of the disease entities are included, along with illustrative material from the authors' experience.     

Lymphoepithelial cyst of the pancreas: radiological and pathological findings

We report a case of a rare lymphoepithelial cyst of the body of the pancreas that developed in a woman complaining of constipation for 15 years. Ultrasonography revealed a homogeneous isoechoic lesion, while CT demonstrated a polycystic homogeneous mass with central scar and calcification. Cytological investigation of a CT-guided biopsy permitted diagnosis of lymphoepithelial cyst. The patient was operated on and had an uneventful recovery. The histological finding was of a cyst wall lined with keratinised squamous epithelium surrounded by lymphoid tissue with reactive follicular hyperplasia. The radiological findings and differential diagnosis are discussed. Correspondence to: D. Regge     

Effect of joint position and ligament tension on the MR signal intensity of the cruciate ligaments of the knee

Six cadaveric lower extremities were imaged with T1-weighted spin-echo pulse sequences with the knees extended and flexed to 90°. Magnetic resonance signal intensities of the anterior cruciate ligament (ACL) and posterior cruciate ligament (PCL) were compared. Changing from extension to flexion resulted in decreased signal intensity in six of six ACLs and five of six PCLs. Two of the knees were then imaged with and without tension applied to the ACL. Both specimens showed a decrease in signal intensity with tension, followed by an increase in signal intensity with release of the tension. Finally, in three of the limbs the ACL was surgically reconstructed and then imaged with and without tension applied to the tension graft. Signal intensity decreased with tension and increased with release of the tension in all three specimens. Thus, joint position and changes in ligament tension affect the signal intensity of the ACL and PCL, generally resulting in a signal intensity decrease with tension.     

CT and MR assessment of tumors of the nose and paranasal sinuses,the nasopharynx and the parapharyngeal space using ROC methodology

Summary Neoplastic disease of the nose and paranasal sinuses, the nasopharynx and the parapharyngeal space requires thorough assessment of location and extension in order to plan appropriate treatment. This study evaluates computer tomography and magnetic resonance imaging in the workup of malignant and non-malignant tumors of the nose and paranasal sinuses, the nasopharynx and the parapharyngeal space in 76 patients. An attempt is made to characterize histopathology on magnetic resonance images by analyzing the signal intensities on T1- and T2-weighted images relative to muscle and brain tissue. The test performance of computer tomography and magnetic resonance imaging in the assessment of tumor extension are compared with receiver operating characteristic methodology. Although no definitive conclusions can be made as to the histopathology on the basis of the signal intensities on magnetic resonance imaging, some tumors show characteristic images. Receiver operating characteristic analysis of the performance of computer tomography and magnetic resonance imaging in the assessment of extension of neoplastic disease of the nose and paranasal sinuses, the nasopharynx and the parapharyngeal space, demonstrates no statistically significant difference in overall test performance. However, in evaluating regions involving predominantly soft tissue structures and comparatively large bony structures magnetic resonance imaging is superior to computer tomography, whereas in evaluating regions involving thin bony structures, computer tomography performs better than magnetic resonance imaging.     

Cysticercosis of the masseter: MRI and sonographic correlation

Cysticercal involvement of the masseter is an uncommon manifestation of a relatively common parasitic infestation. Sonographic evaluation of many isolated cases of cysticercosis has been extensively described. However, there are scanty reports on MRI appearance of cysticercal involvement of the masseter. This report presents classical imaging appearance of cysticercal involvement of the masseter on sonography and MRI. The pattern of the disease and MRI appearance of lesions in the masseter, highlighting the role of diffusion-weighted images, are described.     

Nodular sarcoidosis of the liver and spleen: Appearance on MR images

Small nodular lesions in the liver and spleen have been reported as an infrequent manifestation of sarcoidosis. Five patients with this appearance on either dynamic contrast material—enhanced computed tomographic (CT) or ultrasound scans underwent magnetic resonance (MR) imaging with and without dynamic gadolinium enhancement. The lesions were relatively uniform in size, ranging from 0.5 to 1.5 cm. On CT scans, they were hypoattenuating relative to surrounding parenchyma. On MR images, the lesions were hypointense relative to background parenchyma with all sequences. No substantial enhancement was observed in the lesions, although lesion conspicuity decreased over time on serial postcontrast images. Lesion conspicuity was greatest on either T2-weighted fat-suppressed (T2FS) images or early-phase dynamic contrast-enhanced images. Abdominal adenopathy was seen in three of the five patients and was hyperintense relative to liver on T2FS images in two and intermediate in intensity in one patient.     

Subgaleal and epidural metastases of the undifferentiated embryonal sarcoma of the liver

Undifferentiated embryonal sarcoma of the liver (UESL) is very rare and has a very poor prognosis. UESL metastases have been reported in 5%-13% of the children with UESL and most metastases reported in the literature are present at diagnosis. Metastases reported in the literature belong to the lungs, pleura, and peritoneum. Radiological diagnosis of the UESL remains a poorly understood problem due to its rarity. Most of the reports published in the literature are also based on a relatively small number of patients. Approximately 200 cases have been reported regarding imaging features of this tumor. We reported a girl with UESL, who applied to the emergency department with abdominal pain. The lesion was solid and had cystic areas on ultrasound and there were peripherally enhanced serpenginous vessels in the lesion on Computed Tomography and MRI. Immunohistochemical diagnosis of the lesion was UESL. 26 months after surgery and adjuvant chemotherapy extradural and subcutaneus metastases were detected. These metastasis sites were first described for UESL.