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

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

One hundred forty-seven human neuroendocrine tumors were immunocytochemically screened with antibodies directed against several portions of peptidylglycine α-amidating monooxygenase, the enzyme responsible for the amidation of neurohormonal peptides. A subset of 23 tumors was then studied by enzyme assay and immunoblotting. Although the enzyme was present in all neuroendocrine cell types, the specimens with the highest content were from well-differentiated tumors known to produce amidated peptides, such as intestinal and bronchial carcinoids, gastrinomas, medullary thyroid carcinomas, and pancreatic polypeptide-producing tumors. A high enzyme content also was observed in well-differentiated tumors not known to contain amidated products (e.g., gastric carcinoids). A good correlation was observed between staining intensity of the enzyme on protein blots and immunocytochemical signal. Tumor-specific differences in cleavage of the less active high-molecular-weight forms may contribute to discrepancies between enzyme activity level and immunochemical expression. Although no clear-cut association was found between enzyme immunoreactivity and expression of a single granin, canonic secretory granule markers, all enzyme-reactive tumors were found to contain high levels of at least one of the three granins (chromogranin A, chromogranin B, or secretogranin II).

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The role of cathepsin D and androgen (AR), estrogen (ER), and progesterone receptor (PR) status in prostate tumor growth and invasion was investigated using immunohistochemistry in 60 paraffin-embedded sections from radical prostatectomy specimens. Results were assessed by semiquantitative image analysis in prostate cancers, benign prostatic hyperplasia (BPH), and areas of prostatic intraepithelial neoplasia (PIN) adjacent to tumor. Of the 60 prostatic sections, 73% expressed cathepsin D,90% AR, 30% ER, and 18.3% PR. Antibodies exhibited heterogeneous immunostaining and distribution patterns. In epithelial cells, cathepsin D immunoreactivity was predominantly cytoplasmic; that of AR, ER, and PR was mainly nuclear. In PIN tissue, cathepsin D and steroid receptors concentrated in the basal layer, in BPH in the secretory luminal cells. Cathepsin D, AR, and ER histologic scores progressively increased from BPH to PIN to prostate cancer, whereas PR histologic scores were higher in BPH than in prostate cancer or PIN. AR, ER, and PR histologic scores did not correlate significantly with the histologic grade of malignancy, whereas cathepsin D protein levels were significantly higher in Gleason score sum 7 tumors than in Gleason score sum 5 and 6. Spearman rank's analysis showed that cathepsin D correlated significantly with ER and PR H-scores, but not with AR. Densitometric analysis of immunostained antigens is a valid method for assessing cathepsin D and steroid receptor status in prostate tumors. The heterogeneity of cathepsin D and steroid receptor expression reflects the heterogeneity of prostatic tissue. The expression of cathepsin D could be modulated by estrogens in the prostate, as suggested by the positive correlation between cathepsin D and ER. Cathepsin D may intervene in the progression of prostate cancer and acts independently of AR.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

The pathogenetic and prognostic role ascribed by several studies to p53 alterations and the availability of antibodies that recognize p53 protein in paraffin-embedded tissue prompted translational research on the clinical role of p53 accumulation, mainly in breast cancer. However, few studies evaluated the possible interference of fixation time and use of antigen retrieval on p53 detection. In this study, the comparative analysis of immunoreactivity, detected by three p53-specific antibodies (PAb1801, DO7, and CM1), on 87 6-hour formalin-fixed breast carcinomas showed a remarkable agreement in qualitative and quantitative evaluations. The interference of fixation time and microwave oven (MWO) irradiation was analyzed in a subset of 40 randomly selected cases, in which specular specimens were formalin fixed for 6 or 24 hours. Among the 20 cases in which p53 accumulation was detectable after 6 hours of fixation, p53 immunoreactivity disappeared in 14 (70%) after 24-hour fixation without antigen retrieval and was restored in 13 (93%) by MWO irradiation. MWO treatment significantly increased the number of p53-immunoreactive cells compared with those detected after a short-term (6-hour) fixation but did not affect the lack of immunoreactivity of p53-negative cases. These results could have practical implications in the presence of a significant relation between the fraction of p53-positive cells, considered as a continuous variable, and clinical outcome. Moreover, they support the need for a methodologic standardization to guarantee interlaboratory reproducibility of p53 immunostaining and to allow interinstitutional comparison of results.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Hormone receptor status in neoplasms such as breast adenocarcinoma has been well established as providing valuable prognostic and therapeutic information. Analogous data regarding the significance of the androgen receptor (AR) in prostatic adenocarcinoma are less well documented. A retrospective study correlating AR expression in prostatic adenocarcinoma with clinical outcome would be greatly facilitated if formalin-fixed, paraffin-embedded archival tissue could be used. However, we had anecdotally noted that formalin-fixed, paraffin-embedded prostate tissue older than 10 years demonstrated virtually no immunoreactivity for the AR, whereas recent cases processed in a similar fashion invariably demonstrated immunoreactivity when using the monoclonal antibody F39.4.1. We hypothesized that AR immunoreactivity decayed over time in formalin-fixed, paraffin-embedded material, making retrospective studies of such archived tissue unreliable with this particular monoclonal antibody. Formalin-fixed, paraffin-embedded archival tissue from nine prostatic adenocarcinomas was examined at four points in time. Multiple sections from the paraffin block were cut for each case at time A (December 1995), time B (A + 15 months, March 1997), time C (A + 18 months, June 1997), and time D (A + 22 months, October 1997). The avidin-biotin-peroxidase method was used to immunostain these sections with an immunoglobulin G (IgG) kappa monoclonal antibody directed against the AR (F39.4.1 supplied by BioGenex, San Ramon, CA, U.S.A.). A methyl-green counterstain was used to identify the background tissue and highlight nuclei. Image acquisition and analysis were performed by using a CAS 200 image analyzer (Becton Dickinson Cell Analysis Systems, Mountain View, CA, U.S.A.). AR was quantitated by measuring the percentage of the nuclear area demonstrating immunostaining. At least 50 high-power fields of adenocarcinoma for each case at each point in time were evaluated for AR reactivity. Immunoreactivity declined markedly at each data set retrieved from successive points in time. The positive areas averaged for all cases at each time revealed an overall decrease in AR positivity of 12.2% from time A to time B (15 months), a 38% decrease from time A to time C (18 months), and a 39.8% decrease from time A to time D (22 months). AR immunoreactivity in archived, formalin-fixed, paraffin-embedded tissue appears to decay in a continuous manner when assayed by using the monoclonal antibody F39.4.1. This decay excludes the use of this antibody for retrospective studies that correlate AR status with prognosis or therapeutic response.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

Immunolabeling is commonly used to localize antigens within frozen or paraffin tissue sections. We modified existing immunolabeling techniques to allow the detection of three antigens simultaneously within the one tissue section. The approach relies on the use of three monoclonal antibodies in sequential immunoperoxidase staining steps, each with colored substrates, resulting in the deposition of black, brown, and rose stains. The method is rapid and does not require novel techniques or materials. In this report, we demonstrate the colocalization of mast cell tryptase, neurofilament protein, and CD31 (platelet-endothelial cell adhesion molecule) or laminin in normal human skin and normal buccal mucosa, as an illustration of the power and simplicity of the multiple antigen localization technique.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

A large panel of cytokeratin (CK) subset antibodies was tested in a variety of sarcomas to evaluate their specificity in the differential diagnosis of sarcoma versus spindle cell carcinoma. Seventy-five different sarcomas were immunostained with AE1/3, CAM5.2, 34BE12, and antibodies against CK5/6, CK7, CK8, CK13, CK14, CK19, and CK20 on paraffin sections. Two other epithelial markers, epithelial membrane antigen and desmosomal glycoprotein, were also tested. Fifteen of 75 (20%) sarcomas showed immunoreactivity with one or more antibodies tested in the panel. Forty-seven percent of CK-positive sarcomas showed immunoreactivity with more than one antibody. Except for CK8, CK subset immunoreactivity was focal and weak in most instances. Among the sarcomas tested, gastrointestinal stromal tumor most frequently showed CK reactivity (50%), with CK8 being the most frequent (38%). Compared with the immunoreactivity with CK8 or CAM5.2 (13% and 9%, respectively), the new subset antibodies (CK5/6, CK7, CK13, CK14, and CK20) showed a low incidence of focal and weak aberrant expression (2%-5%). These new CK subset antibodies may be useful in the differential diagnosis of spindle cell carcinoma versus sarcoma, given the low frequency of aberrant reactivity in nonepithelial tumors.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID

摘要:

We compared a novel monoclonal antibody to progesterone receptor, said to result in no cytoplasmic immunostain, with the polyclonal antibody we presently use, with three different detection systems. Fixed embedded sections from 58 consecutive cases were immunostained with an avidin/streptavidin-biotin complex technique, steam antigen retrieval, and an automated immunostaining system. Progesterone receptor polyclonal antibody (1/50; Dako, Carpinteria, CA, U.S.A.) was used with BioTek (BioTek Solutions, Tucson, AZ, U.S.A.) and Signet (Dedham, MA, U.S.A.) Detection Kits, and anti-progesterone receptor (1/40; BioGenex, San Ramon, CA, U.S.A.) with Signet and BioGenex Detection Systems. Immunostain was assessed as 0 to 3+ intensity, percentage of nuclei immunopositive, amount of background (0-3+), and ease of interpretation 1-4). In 49 (85%; seven negative, 42 positive) cases, concordant results were obtained with all four methods; in six, the percentage of nuclei expressing progesterone receptor was ⩾20% lower with the Dako than the BioGenex antibody. The nine discordant cases were the result of false negatives with the Dako (five) and BioGenex (four) antiserum. There was no background in 27 Dako/BioTek, 27 Dako/Signet, 46 BioGenex/Signet, and 53 BioGenex/BioGenex, and 1+/2++ background in 22/9 Dako/BioTek, 27/4 Dako/Signet, 11/1 BioGenex/Signet, and 5/0 BioGenex/BioGenex. Ease of interpretation was optimal (1) in seven Dako/BioTek, nine Dako/Signet, 42 BioGenex/Signet, and 34 BioGenex/BioGenex. The new BioGenex progesterone receptor monoclonal antibody gives sharp, easily interpreted nuclear immunostain with no to minimal background with both Signet and BioGenex detection kits. The Dako progesterone-receptor polyclonal antibody results in cytoplasmic immunostain with the BioTek and Signet Detection Kits, which makes interpretation of 0 to 1+ intensity nuclear immunostain difficult.

ISSN:1062-3345    

出版商:OVID    

年代:1998

数据来源: OVID