ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

EnVision+ (EV+, Dako, Copenhagen, Denmark) is a novel two-layer dextran polymer visualization system for immunohistochemistry. We compared EV+ with two sensitive three-layer techniques: an avidin-biotin complex (ABC) system (Vectastain Elite ABC Kit [VABC], Vector, Burlingame, CA, U.S.A.) and a labeled streptavidin-biotin (LSAB) system (nonkit; Dako). Sections from multitissue and other paraffin blocks of formalin-fixed tissues were stained and 10 selected antibodies applied. Furthermore, in a comparison of EV+ and LSAB, 100 of the most frequently used antibodies were applied. In most of the cases, EV+ and VABC equally enhanced the stainings twofold to fourfold compared with LSAB. After adjusting the primary antibody concentrations, the staining results were practically identical. However, when applying some high-concentration antibodies, a comparable staining intensity with the LSAB system produced unacceptable background staining. With the EV+ technique, the stainings were devoid of false-positive reaction due to endogenous biotin. In a few cases, EV+ produced faint staining of collagen and smooth muscle, as well as faint staining of nuclei in a minority of the cells; however, this never interfered with the interpretation of the stainings. The EV+ system is more expensive than the two other systems; however, because it completely overcomes problems with endogenous biotin, EV+ may allow a more efficient heat-induced epitope retrieval (HIER) and, thus, a further dilution of antibodies. Moreover, savings may be gained from a shorter assay time (40 minutes) and a simplified technique. EV+ appears to be a good alternative to the avidin-biotin-based visualization systems.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Many characteristics of epithelial cells are moderated through interactions with adjacent stromal components. In tumor cells, abnormal interactions between cells and stroma can be important determinants of malignant progression, including invasion and metastasis. Evidence has accumulated for the importance of the interaction between the stromal component hyaluronic acid (HA) and its major cell surface receptor, CD44S, in invasion and metastasis. Because malignant mesotheliomas are characterized by the accumulation of abundant HA, we chose to evaluate this group of tumors for the presence of stromal HA, cellular HA, and CD44S, the CD44 molecule that is principal receptor for HA. For comparison, we also analyzed a group of lung adenocarcinomas and several reactive mesothelial hyperplasias, two entities that are often included in the differential diagnosis of malignant mesothelioma. In 10 of 12 (83%) reactive mesothelial hyperplasias, 14 of 22 (63%) mesotheliomas, and 9 of 26 (34%) adenocarcinomas, membrane immunoreactivity with CD44S could be demonstrated, a difference that was statistically significant between adenocarcinomas and reactive mesothelial hyperplasias (p= 0.0128) and approached significance between adenocarcinomas and mesotheliomas (p= 0.0810). Adenocarcinomas, when positive, were more likely to show more focal staining compared with the more common diffuse staining in mesotheliomas. Although a high percentage of samples from all three groups showed stromal HA, cellular HA was much more common in mesothelioma cells (20 of 22; 91%) than in either adenocarcinomas (4 of 26; 15%,p< 0.0001) or mesothelial hyperplasias (2 of 12; 17%,p= 0.0001). Comparison of HA staining with standard immunohistochemical markers is needed to demonstrate the diagnostic utility of this stain.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

T-cell-rich B-cell lymphoma (TCRBCL), a variant of B-cell non-Hodgkin's lymphoma associated with an extensive nonneoplastic infiltrate of T cells, may be difficult to distinguish from other lymphoproliferative disorders, particularly when only limited biopsy specimens are available. The differential diagnosis usually includes lymphocyte predominance Hodgkin's disease (LPHD), which, although typically associated with nodular infiltrates, may exhibit a mixed nodular and diffuse or diffuse pattern of infiltration, with large neoplastic cells interspersed with small lymphocytes in a pattern that resembles TCRBCL. LPHD typically has a well-defined dendritic reticulum cell (DRC) network associated with the neoplastic infiltrate, but the presence of DRC in TCRBCL has not been well studied. To determine whether DRC staining is a useful marker to distinguish TCRBCL from LPHD, we examined formalin-fixed, paraffin-embedded tissue from lesions that fulfill the histologic and immunophenotypic criteria for TCRBCL for DRC staining with antibodies for CD21 and low-affinity nerve growth factor (LNGFR) receptor and compared this staining with that seen in typical cases of LPHD. As expected, 17 of 17 cases (100%) of LPHD exhibited DRC staining in an expanded follicular meshwork pattern. In contrast, none of the 15 cases of TCRBCL, including cases rich in histiocytes, exhibited DRC staining associated with the neoplastic infiltrate, except in residual, nonneoplastic germinal centers. We conclude that DRC staining is helpful for distinguishing TCRBCL from LPHD.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Immunocytochemical studies on fine needle aspiration (FNA) material often yield inconsistent results. We undertook this study to determine the influence of variation in specimen preservation and processing on results of immunocytochemical staining. Multiple cytospin slides were made from material obtained by FNA of 15 surgical specimens of carcinomas. Variables studied included transport medium/initial preservative (50% ethanol versus CytoLyt), time (CytoLyt or PreservCyt for up to 5 days), slide fixative (acetone, 95% ethanol, or alcohol: formalin 50: 50 vol: vol), and time in fixative (1, 5, 10, or 20 minutes). Slides were stained with a cocktail of antibodies recognizing cytokeratin. Formalin-fixed tissue sections of corresponding surgical specimens served as positive controls; cytospin slides stained with mouse myeloma protein served as negative controls. The stained slides were evaluated using a semi quantitative system for intensity of staining (i.e., 1, 2, or 3, in which 3 equals the same intensity as the tissue sections), background staining (clean versus dirty/obscuring), and cellular preservation (cell morphology: 1, poor; 2, fair; 3, good). CytoLyt and 50% ethanol are comparable in all three aspects (staining intensity, background, and cellular preservation) evaluated. Fixation with formol alcohol gave suboptimal immunocytochemical staining, whereas acetone and 95% ethanol are comparable in this regard. Five minutes appears to be the optimal duration for cellular preservation on slides fixed in acetone or 95% ethanol. Other than these findings, none of the procedural variations made a detectable difference in the results. Antigenicity was well preserved in cells maintained in CytoLyt or PreservCyt for up to 5 days.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Malignant cells are characterized by abnormalities of the cytoskeleton, and actin filaments in particular show marked disturbances of this normally well-organized network. Of the many actin-binding proteins, gelsolin plays a particularly important role in the remodeling of the actin cytoskeleton. Gelsolin expression is lost in transformed cells and in carcinomas of the breast and bladder, suggesting a role for gelsolin as a tumor suppressor. Because other human cancers have not yet been studied, we analyzed carcinomas of the endometrium and ovary for changes in gelsolin expression. Normal endometrial glands were positive in the secretory phase, whereas proliferative glands had lost expression. Although both simple and complex endometrial hyperplasias without atypia expressed gelsolin, some complex hyperplasias with atypia lost gelsolin expression. Expression in endometrial adenocarcinomas was related to grade; 11 of 14 grade II and III tumors were negative compared with 0 of 2 grade I tumors. However, grade I foci within the grade II and III tumors retained gelsolin expression, as did areas exhibiting squamous differentiation, regardless of the grade of the glandular component. Normal ovarian surface epithelium and all 4 ovarian cystadenomas expressed gelsolin, whereas 13 of 13 serous and mucinous carcinomas were negative. In contrast, 3 of 4 ovarian clear cell carcinomas were positive. The loss of gelsolin expression in ovarian and endometrial carcinomas is consistent with a tumor suppressor function for gelsolin, although its absence in proliferative glands and expression in squamous differentiation suggests a more complex relation than that previously reported for other tumors. Further investigation is needed to establish whether or not gelsolin expression provides diagnostic or prognostic information.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

It has been repeatedly shown that exposure to formaldehyde produces progressive loss of tissue epitopes. In the past few years, different physical methods-for example, techniques based on ultrasound (US), microwave (MW), and pressure cooker (PC) technology-have been developed for recovering masked antigens and allowing immunohistochemical (IHC) staining. Taking into account that many antigens were recovered using these retrieval methods after deparaffination of tissue sections, we wanted to test whether it is possible to recover muscular desmin, as an antigen model, before tissue embedding in paraffin (i.e., preembedding epitope retrieval [PRER]). For this purpose, the three physical retrieval methods already mentioned were employed and statistically compared, and a comparison with the conventional postembedding epitope retrieval (POER) techniques was also made. We have found that preembedding treatment with MW and PC methods was entirely inappropriate for the recovery of desmin in tissue blocks, whereas the US PRER was able to unmask desmin in most formalinfixed skeletal muscle pieces and the combination of US PRER and different POER methods allowed a greater amount of desmin to be unmasked. Additionally, no overheating of tissue blocks or detachment of tissue sections was observed; thus, this approach could be suitable to obtain enough material for hundreds of sections to work with as many unmasked epitopes as possible in a few seconds of sonication.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The lack of specific immunohistochemical markers for adrenocortical tumors often causes problems in pathologic diagnosis of adrenal neoplasms. Inhibin is a glycoprotein that is normally expressed in gonadal sex cord stromal elements and tumors and in normal adrenocortical cells. The immunohistochemical expression of inhibin A was studied in a series of 58 adrenal tumors, which included pheochromocytomas, adrenocortical adenomas and carcinomas, and metastatic carcinomas. Twelve renal cell carcinomas were also evaluated. Normal adrenal cortex showed a moderately uniform staining pattern: weak staining in the glomerular layer, moderate in the fascicular layer, and a strong and diffuse reactivity in the reticular zone. All 20 adrenocortical adenomas were strongly and diffusely positive, although those associated with hyperaldosteronism exhibited a patchy staining distribution. Seven of 8 adrenocortical carcinomas were strongly and diffusely positive, whereas 10 of 11 pheochromocytomas were negative. Conversely, inhibin was not detected in any adrenal metastases and renal cell carcinomas. The results suggest that inhibin A may be a good marker for adrenocortical tumors and may be of great interest in the differential diagnosis with pheochromocytomas, metastatic tumors, and renal cell carcinomas that spread into the retroperitoneum.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We describe a patient with an incidental finding of prostatic tissue in the uterine cervix. There was immunohistochemical evidence of its prostatic nature, as shown by its positivity to prostate-specific antigen (PSA) and prostate acid phosphatase (PAP), and female genetic profile was confirmed by the fluorescence in situ hybridization (FISH) technique. To our knowledge this is the first report of prostatic tissue in the uterine cervix, and of the use of the FISH technique to exclude mismatching of the biopsy material with a male prostate.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID