Chiu K Y, Loke S L, Ho F C
Department of Pathology, University of Hong Kong, Queen Mary Hospital Compound, Hong Kong.
J Clin Pathol. 1994 Feb;47(2):117-21. doi: 10.1136/jcp.47.2.117.
To investigate the effects of fixation on the immunohistochemical demonstration of c-erbB-2 oncoprotein using paraffin wax and cryostat sections; to compare c-erbB-2 expression in non-neoplastic and neoplastic gastric tissues.
Adjacent blocks of tumour and non-neoplastic tissue from four gastrectomy specimens were put into a panel of 10 fixatives including acetone, B5, Bouin's fluid, Carnoy's fluid, buffered formalin, formol dichromate, zinc formalin, 4% paraformaldehyde, periodate-lysine-paraformaldehyde (PLP) and periodate-lysine-paraformaldehyde-dichromate (PLPD) before embedding in paraffin wax for sectioning. Similar tissue blocks were snap frozen and cryostat sections were postfixed in these fixatives, either alone or in combination, before immunostaining.
In paraffin wax embedded sections the best fixative was PLP, and in frozen tissues the best results were obtained after fixation of cryostat sections in buffered formalin followed by cold methanol and acetone. Applying these fixatives to samples from a further 16 gastrectomy specimens, strong membrane staining of c-erbB-2 protein was found in the tumour in eight of 16 cases (50%) using paraffin wax sections, and staining was stronger in the better differentiated carcinomas. For frozen tissues, positive membrane staining was found in all gastric adenocarcinomas, but differential staining intensity associated with tumour differentiation could not be detected.
These results indicate that fixation and paraffin wax embedding affect the results of immunohistochemical demonstration of c-erbB-2 in gastric cancer. The choice of fixative is critical in the demonstration and evaluation of c-erbB-2 protein expression by immunohistochemistry in gastric carcinomas. Staining results also vary depending on whether frozen or paraffin wax embedded tissues are studied.
研究固定对石蜡切片和冰冻切片免疫组化检测c-erbB-2癌蛋白的影响；比较非肿瘤性和肿瘤性胃组织中c-erbB-2的表达。
将取自4例胃切除标本的肿瘤及非肿瘤组织相邻块置于10种固定剂中，包括丙酮、B5、波因氏液、卡诺氏液、缓冲福尔马林、甲醛重铬酸钾、锌福尔马林、4%多聚甲醛、高碘酸盐-赖氨酸-多聚甲醛（PLP）和高碘酸盐-赖氨酸-多聚甲醛-重铬酸钾（PLPD），然后石蜡包埋切片。将相似的组织块速冻，冰冻切片在免疫染色前单独或联合使用这些固定剂进行后固定。
在石蜡包埋切片中，最佳固定剂是PLP；在冰冻组织中，冰冻切片经缓冲福尔马林固定后再用冷甲醇和丙酮处理，效果最佳。将这些固定剂应用于另外16例胃切除标本的样本，石蜡切片检测发现，16例中有8例（50%）肿瘤组织中c-erbB-2蛋白呈强膜染色，且在高分化癌中染色更强。对于冰冻组织，所有胃腺癌均发现阳性膜染色，但未检测到与肿瘤分化相关的染色强度差异。
这些结果表明，固定和石蜡包埋会影响胃癌中c-erbB-2免疫组化检测结果。在胃癌中，通过免疫组化检测和评估c-erbB-2蛋白表达时固定剂的选择至关重要。根据研究的是冰冻组织还是石蜡包埋组织，染色结果也会有所不同。
