Adenocarcinoma of the urachus and bladder expresses a unique colonic epithelial epitope: an immunohistochemical study

PURPOSE: Primary adenocarcinoma of the bladder is a rare neoplasm whose histogenesis is poorly understood. Current data support the concept that adenocarcinoma of the bladder and urachus evolves from zones of intestinal metaplasia that become dysplastic and invasive. To address this hypothesis further we determined the immunoreactivity of benign and malignant epithelial tissue from the bladder and urachus with a monoclonal antibody that is reactive with colonic epithelium to evaluate the presence of a common reactive epitope. MATERIALS AND METHODS: The monoclonal antibody 7E12H12 (IgM isotype), developed against a colonic epithelial protein, was used in an immunoperoxidase assay to survey formalin fixed, paraffin embedded archival tissue specimens. A total of 26 specimens obtained by endoscopic biopsy or extirpative surgery, including benign and malignant bladder and urachal epithelial abnormalities, was chosen for retrospective evaluation. RESULTS: All adenocarcinoma reacted positively regardless of the histological variant, differentiation, or bladder or urachal origin. In contrast, transitional cell and squamous cell carcinomas were nonreactive. Also, the pattern of reactivity in tissues that contained benign epithelial proliferations suggested a stepwise transition with no reactivity in normal urothelium or Brunn's epithelial nests, rare staining of cystitis cystica, and uniformly positive reactivity in cystitis glandularis and frank colonic intestinal metaplasia of the bladder and urachus. CONCLUSIONS: The shared, aberrant phenotypic expression of a unique colonic epitope in benign epithelial metaplasia, and adenocarcinoma of the bladder and urachus suggests a common underlying pathway toward adenocarcinoma in cystic and urachal adenocarcinoma. The implications for diagnostic pathology are discussed.     

Chronic pancreatitis and neoplasia: correlation or coincidence

Renal biopsy specimens from patients with membranous nephropathy (MN) were studied using immunohistochemical labelling to clarify the aetiological significance of Helicobacter pylori antigen in this disease. Sixteen specimens were examined, from 7 male and 9 female MN patients. Renal specimens from patients with diabetic nephropathy and IgA nephropathy, and from autopsied patients without renal diseases were obtained as controls. Immunohistochemical labelling was performed using one polyclonal antibody and three monoclonal antibodies against H. pylori. Specimens from 11 of the MN patients revealed granular deposits along the glomerular capillary walls, which reacted positively with polyclonal antibody after trypsin pretreatment. None of the control specimens revealed positive labelling. The MN specimens showed no positive reaction with the primary antibody, which had been treated for immunoabsorption testing using sonicated H. pylori. We also determined H. pylori status in these MN patients histologically and/or serologically. Of the 11 patients whose glomeruli were positive for anti-H. pylori antibody, 7 were suitable for analysis, and all were regarded as positive for H. pylori infection. These results suggest that the presence of a specific antigen in the glomeruli of patients with MN and H. pylori infection may be involved in the pathogenesis of MN.     

Lipofuscin pigmentation (so-called "melanosis") of the prostate

Although intraepithelial pigment in the prostate gland has been termed melanosis, the nature of the pigment is not entirely clear, and many pathologists are not aware of its existence. We examined 863 hematoxylin and eosin (H + E) stained slides from 150 surgical specimens of prostate (69 needle biopsies, 66 transurethral resections, 14 radical prostatectomies, and 1 suprapubic prostatectomy) from 149 patients (age range, 47 to 90 years; mean 70 years) in an effort to characterize this pigment. The 1-3 microns in diameter, predominantly subnuclear, yellow-brown to gray-brown granules with a dark blue rim (by H + E) stained positively with Fontana-Masson, periodic acid-Schiff with diastase, Congo red, luxol fast blue, and oil-red-O and exhibited yellow autofluorescence consistent with lipofuscin. H + E stained slides revealed pigment in the benign epithelium in 86 of 150 cases (57%), within stromal macrophages in eight cases, and in atypical epithelium in two cases of high-grade prostatic intraepithelial neoplasia. Ten cases of invasive adenocarcinoma without recognizable pigment in H + E stained sections were stained by the Fontana-Masson technique, and pigment was identified in malignant epithelium in three of these cases. Ultrastructural examination of intraepithelial pigment in KII-fixed tissue from three radical prostatectomy specimens demonstrated the typical appearance of lipofuscin. Although intraepithelial pigment in prostatic biopsy or resection specimens is usually considered characteristic of seminal vesicle epithelium, our study demonstrates that lipofuscin is commonly present in epithelial cells of benign prostatic hyperplasia and less frequently in those of prostatic intraepithelial neoplasia and adenocarcinoma. The recognition of this pigment is important in preventing diagnostic confusion with seminal vesicle epithelium and with melanocytic lesions.     

Visual evoked potentials in phenylketonuria: association with brain MRI, dietary state, and IQ

Tumor-associated glycoprotein 72 is a high-molecular-weight sialomucin that is expressed selectively in various adenocarcinomas, including those of the prostate. We utilized the monoclonal antibodies B72.3 and CC49 to examine the expression of TAG-72 in high-grade prostatic intraepithelial neoplasia (PIN), localized adenocarcinomas (pathologic stages B and C), as well as matching primary and nodal lesions from patients with stage D adenocarcinomas. Immunoreactivity within PIN lesions was detected within 20 (87%) and 17 (74%) of 23 specimens immunostained with B72.3 and CC49, respectively. Benign epithelium and stromal tissue did not immunostain with either antibody at the concentrations tested. Immunostaining was detected within the malignant cells in 30 (77%) and 35 (90%) of 39 localized adenocarcinomas using B72.3 and CC49, respectively. Immunostaining was localized to the cytoplasm and cellular membranes of the malignant cells and within the lumen of malignant glands. Seven of 17 (41%) primary lesions from patients with stage D adenocarcinomas demonstrated immunoreactivity when stained with B72.3. Immunoreactivity was detected in 8 of 10 (80%) of these tissues immunostained with CC49. Within nodal lesions obtained from these patients, immunostaining was observed in 3 of 17 (18%) and 6 of 10 (60%) of the specimens immunostained with B72.3 and CC49, respectively. We used a semiquantitative technique to compare the extent of immunoreactivity among well-differentiated (Gleason score < 6), moderately differentiated (Gleason 6-7), and poorly differentiated (Gleason score > 7) tumors. We observed an inverse correlation of TAG-72 expression to Gleason scores. Furthermore, TAG-72 expression was reduced in the matching primary and metastatic lesions of stage D adenocarcinomas as compared to localized lesions.(ABSTRACT TRUNCATED AT 250 WORDS)     

Synchronous and metachronous primary gastric lymphoma and adenocarcinoma: a clinicopathological study of 12 patients

BACKGROUND: The occurrence of both malignant gastric lymphoma and adenocarcinoma in the same patient is very rare. METHODS: The resected specimens from 12 patients who had both primary gastric lymphoma and adenocarcinoma were analyzed using immunohistochemistry and in situ hybridization. RESULTS: Two different tumors were found synchronously in 10 patients (5 with independent tumors and 5 with contiguous/collision tumors) and metachronously in 2. The size of the lymphomas (mean, 7.2 cm) was larger than that of the adenocarcinomas (mean, 3.6 cm) (P < 0.005). Histologically, 9 of the 12 lymphomas (75%) were mucosa-associated lymphoid tissue lymphomas, and all lymphomas invaded the deep portion of the submucosa or deeper. Conversely, 10 of the 12 adenocarcinomas (83%) were early carcinomas. Six adenocarcinomas were intestinal type, whereas the other 6 were diffuse type. The MIB-1 index of the adenocarcinomas (mean, 50.4%) was higher than that of the lymphomas (mean, 29.3%) (P < 0.05). Helicobacter pylori (H. pylori) was documented in all 12 patients, whereas Epstein-Barr virus-encoded RNA 1 was detected in only 2. During the follow-up period after surgery, 6 patients died, 4 due to adenocarcinoma. The survival probability of all 12 patients appeared to be similar to that of previously reported patients with gastric adenocarcinoma alone, and was significantly worse than that of the 217 patients with gastric lymphoma alone (P < 0.05). CONCLUSIONS: An H. pylori infection is considered to be associated with the development of these double malignancies. In many such synchronously observed cases, lymphomas may precede carcinogenesis, while the prognosis appears to be more closely associated with the adenocarcinoma than the lymphoma.     

Immunohistochemical detection of sialosyl-Tn antigen in carcinoma of the prostate

OBJECTIVE: To investigate the expression of sialosyl-Tn antigen (STn) in human benign and malignant prostate. MATERIALS AND METHODS: The expression of STn was investigated immunohistochemically in formalin-fixed and paraffin-embedded tissue specimens from 56 patients with primary prostatic adenocarcinoma (median age 74.3 years, range 47-89) and 20 patients with benign prostatic hyperplasia (median age 73.4 years, range 60-87). RESULTS: STn was expressed in only three (4%) of the 20 hyperplastic glands and the benign areas adjacent to the 54 carcinomas; by contrast, STn was expressed in 34 (61%) of the 56 carcinomas. The frequency of STn positivity was much higher in well-differentiated carcinomas than in those poorly differentiated. CONCLUSION: STn is expressed with malignant transformation of the prostatic epithelial cells and immunohistochemical methods using commercially available STn monoclonal antibody may be useful as an adjunct for distinguishing carcinoma from benign tissue.     

Morphology of brain stem lesion and bera findings after 60Co irradiation

BACKGROUND: We assessed the frequency and molecular basis of p53 mutations in clinically localized prostatic adenocarcinoma. METHODS: Prostate specimens were examined from 100 patients with clinically localized prostatic adenocarcinoma and 13 patients with benign prostatic hyperplasia (BPH). Mutations producing nuclear accumulation of p53 were detected immunohistochemically. Exon-specific mutations were analyzed by polymerase chain reaction amplification and single strand conformation polymorphism (PCR-SSCP) and sequenced. RESULTS: p53 accumulation was detected in 5 tumors using antibody DO-1, and in 4 of these using antibody PAb 1801, but not in BPH. PCR-SSCP detected mutations in all 5 tumors, with alterations in exon 5 for 1 tumor, exon 6 for 3 tumors, and exon 7 for 1 tumor. An exon 6 mutation was also found in a tumor with no anti-p53 staining. CONCLUSIONS: p53 mutations are uncommon in clinically localized prostatic adenocarcinoma and absent from BPH. 5 of the 6 mutations were derived from locally invasive, prostate carcinomas, supporting the hypothesis that mutation of p53 is a late event in prostate carcinoma progression.     

A chicken anti-conoid monoclonal antibody identifies a common epitope which is present on motile stages of Eimeria, Neospora, and Toxoplasma

The chicken monoclonal antibody (mAb) 6D12-G10, raised against Eimeria acervulina sporozoites, has previously been shown to recognize the conoid of E. acervulina sporozoites and inhibit sporozoite invasion of lymphocytes in vitro. In indirect immunofluorescent assay, the mAb 6D12-G10 also reacted with merozoites from E. acervulina and identified a 21-kDa merozoite protein on western blots. By confocal laser scanning microscopy, the conoid of sporozoites from 6 different avian Eimeria species (E. brunetti, E. maxima, E. mitis, E. necatrix, E. praecox, and E. tenella) were reactive with 6D12-G10 mAb. Furthermore, the 6D12-G10 mAb also showed cross-reactivity with motile stages of 2 closely related apicomplexans, Neospora, and Toxoplasma. These results indicate that the mAb 6D12-G10 identifies a conserved epitope on the conoid that is important in host cell invasion by the apicomplexan parasites.     

Evaluation of the premier EHEC assay for detection of Shiga toxin-producing Escherichia coli

An enzyme-linked immunosorbent assay for the detection of Shiga toxins (Premier EHEC assay; Meridian Diagnostics, Inc.) was compared to conventional sorbitol-MacConkey culture for the recovery of enterohemorrhagic Escherichia coli. A total of 74 enteric pathogens, including 8 E. coli O157:H7 isolates, were recovered from 974 stool specimens. Two of these specimens were not tested by Premier assaying due to insufficient sample and are not considered in the data analysis. The Premier EHEC assay detected the 6 evaluable specimens which were culture positive for E. coli O157:H7 and identified an additional 10 specimens as containing Shiga toxin. Seven isolates were recovered from these 10 specimens by an immunoblot assay and were confirmed as toxin producers by a cytotoxin assay. Of these seven, four isolates were serotype O157:H7, one was O26:NM, one was O6:H-, and one was O untypeable:H untypeable. Three specimens contained Shiga toxin by both EHEC immunoassaying and cytotoxin testing; however, no cytotoxin-producing E. coli could be recovered. The sorbitol-MacConkey method had a sensitivity and a specificity of 60 and 100%, respectively, while the Premier EHEC assay had a sensitivity and a specificity of 100 and 99.7%, respectively, for E. coli O157:H7 only. The Premier EHEC assay also detected an additional 20% Shiga toxin-producing E. coli (STEC) that were non-O157:H7. Thus, the Premier EHEC assay is a sensitive and specific method for the detection of all STEC isolates. Routine use would improve the detection of E. coli O157:H7 and allow for determination of the true incidence of STEC other than O157:H7. The presence of blood in the stool and/or the ages of the patients were poor predictors of the presence of STEC. Criteria need to be determined which would allow for the cost-effective incorporation of this assay into the routine screen for enteric pathogens in high-risk individuals, especially children.     

Anorectal miscellany: pilonidal disease, anal cancer, Bowen''s and Paget''s diseases, foreign bodies, and hidradenitis suppurativa

BACKGROUND: Metastatic adenocarcinoma in the liver with an unidentified primary tumor site is a common clinical problem. Pathologists often are asked to identify the primary tumor site. The histologic picture itself usually is not helpful, because the histology may be similar in the metastases of tumors with different primary localizations. Immunohistochemistry can be helpful, but the previously recommended antibody panels are too complicated for everyday use. METHODS: A simple immunohistochemical algorithm with two monoclonal cytokeratin (CK) antibodies, CK20 and CK7, was tested on 93 autopsy cases of adenocarcinomas metastatic to the liver. Sections of the liver metastases were stained automatically and evaluated as negative (no staining), focally positive, or diffusely positive. Statistical comparison of the staining results for a single antibody was calculated as an odds ratio. RESULTS: Thirty-six of 93 (39%) metastases proved to be CK20 positive (+). In this group, the CK20+/CK7 negative (-) pattern was highly characteristic for colorectal localization of the primary tumor, having been observed 17 of 21 of the cases (81%). The CK20+/CK7+ pattern of the metastatic liver adenocarcinomas was highly suggestive of primary localization in the pancreas or biliary tract (11 of 14 cases; 79%). Exclusion of the tumors originating in the stomach raised these values to 94% and 92%, respectively. The statistically calculated predicted probability of primary tumor site being in the colon or rectum for CK20+/CK7- metastasis was 78,41%, the probability of a primary tumor being located in the pancreas or biliary tract was 74,85%, if calculated for the whole study group. CONCLUSIONS: The tested simple algorithm proved to be useful in CK20 positive (+) cases, predicting a primary tumor localization in the colon, rectum, pancreas, or biliary tract with high accuracy. The CK20- group was too heterogeneous to be classified adequately by these two antibodies.     

Circulating immunoglobulin G1 antibody in patients with ulcerative colitis against the colonic epithelial protein detected by a novel monoclonal antibody

Autoimmunity has been implicated in the pathogenesis of ulcerative colitis (UC). Several studies have shown amplified immunoglobulin G1 (IgG1) antibody response in UC; however the immunoreactive antigen(s) is unknown. To study this antigen(s), mucosal colonic extract was prepared by sonication, ultracentrifugation followed by ion exchange chromatography in fast protein liquid chromatography. The fraction (enriched colonic peptide), that was most reactive to a novel monoclonal antibody, 7E12H12 (IgM isotype), was isolated and used to examine the immunoreactivity against the patients' serum samples. Two hundred and thirteen coded samples from 111 patients with UC (symptomatic and untreated (63), symptomatic and treated (26), remission (22)); 47 with Crohn's disease (CD) (40 were symptomatic and untreated, and 30 had colonic disease); 29 with acute diarrhoea caused by specific pathogen(s); 10 with systemic lupus erythematosus, and 16 normal subjects were examined against the enriched colonic peptide by IgG subtype specific enzyme linked immunosorbent assays (ELISAs). Total IgG antibody reactivity was significantly (p < 0.01) higher only in symptomatic and untreated UC patients compared with each of the non-UC group, but the sensitivity was only 50%. IgG2 and IgG3 reactivities were not different among various groups. The IgG1 antibody reactivity against the enriched colonic peptide, however, differentiated UC patients from CD and each of the other non-UC groups. Seventy nine per cent of the patients with UC, treated or untreated, symptomatic or in remission, had significantly (p < 0.0001) higher IgG1 antibody against the enriched colonic peptide when compared with each of the other non-UC groups. Only 12% of CD serum samples and none of the other control serum samples reacted. Using purified serum IgG1 and 7E12H12-IgM, by 7E12H12 reactive peptide indeed reacts with UC-IgG1 antibody but not with control IgG1.     

Cytogenetic and ploidy analysis of prostatic adenocarcinoma

The cytogenetic evaluation of prostatic adenocarcinoma has shown no consistent cytogenetic abnormalities. Despite manipulation of culture conditions, the majority of low-stage, untreated prostatic adenocarcinomas show a normal karyotype. We have performed cytogenetic analysis on eight primary prostate adenocarcinomas, using several control measures to increase the probability that any normal karyotype was derived from neoplastic cells rather than accompanying normal cells. Tumors were grown in media that encourages epithelial growth; DNA ploidy studies were performed before and after tissue culture; and immunohistochemical confirmation of the prostatic and epithelial nature of the cells was done following culture. Percentage of tumor on tissue sections adjacent to those submitted for culture was > 75% in all cases. Seven of eight cases were evaluable, and six cases showed no clonal abnormalities and were diploid. One tumor showed a population of tetraploid cells, without structural abnormalities. Three additional tumors showed evidence of tetraploidy by DNA analysis. One case showed nonclonal marker chromosomes and was aneuploid. This patient was pathologic Stage D. We conclude that the majority of prostatic adenocarcinomas at their inception may not show routinely detectable cytogenetic abnormalities. However, tetraploidy may play a role in the evolution of prostatic adenocarcinoma.     

Analysis of common antigen of flagella in Bacillus cereus and Bacillus thuringiensis

Flagellar antigen of Bacillus cereus H.1 was purified and tested for serodiagnostic antigen by ELISA. The antibody against the flagellar antigen of B. cereus H.1 reacted not only with the homologous specific antigen but also reacted with the flagellar antigens of 23 strains of B. cereus. This common flagellar antigen of B. cereus was found to be due to 61-kDa protein by SDS-PAGE and immunoblot assay. Monoclonal antibody H15A5 against common antigenic epitope of B. cereus also reacted with flagellar antigens of 21 strains of Bacillus thuringiensis by ELISA. This monoclonal antibody reacted with the 61-kDa protein of the flagella of B. cereus H.1 and H.2 and B. thuringiensis Kurstaki HD1, Alesti and Aizawai juroi by immunoblot analysis. These results indicated that the common antigenic epitope of the 61-kDa protein existed in the flagella both of B. cereus and B. thuringiensis.     

Value of cytokeratin 5/6 immunostaining in distinguishing epithelial mesothelioma of the pleura from lung adenocarcinoma

The immunohistochemical diagnosis of mesothelioma is commonly made by using a battery of antibodies that reacts with lung adenocarcinomas but not with epithelial mesotheliomas. Only recently have markers that are often expressed in mesotheliomas but not in adenocarcinomas been recognized. Some of these markers, however, require frozen tissue sections, whereas others are not commercially available, or their value remains controversial. In a recent publication, it was suggested that immunostaining for cytokeratin 5/6 could assist in distinguishing epithelial mesothelioma from lung adenocarcinoma. To determine the practical value of cytokeratin 5/6 immunostaining in the diagnosis of mesothelioma, 40 formalin-fixed, paraffin-embedded epithelial pleural mesotheliomas, 30 pulmonary adenocarcinomas, 93 nonpulmonary adenocarcinomas, 15 squamous carcinomas of the lung, 5 large cell undifferentiated carcinomas of the lung, and 12 metastatic transitional cell carcinomas to the lung were stained with the same antibody, which was obtained from a commercial source. Cytokeratin 5/6 reactivity was observed in all 40 mesotheliomas, but there was none in any of the 30 pulmonary adenocarcinomas. Focal or weak reactivity was observed in 14 of 93 nonpulmonary adenocarcinomas (10 of 30 ovarian, 2 of 10 endometrial, 1 of 18 breast, I of 7 thyroid, 0 of 10 kidney, 0 of 10 colonic, and 0 of 8 prostatic). All 15 squamous carcinomas of the lung, 6 of 12 transitional cell carcinomas metastatic to the lung, and 3 of 5 large cell undifferentiated carcinomas of the lung expressed cytokeratin 5/6. It is concluded that cytokeratin 5/6 immunostaining is not only useful in separating epithelial pleural mesotheliomas from pulmonary adenocarcinomas but also can assist in distinguishing epithelial mesotheliomas from nonpulmonary adenocarcinomas metastatic to the pleura.     

Application of multiplex PCR for detection of non-O157 verocytotoxin-producing Escherichia coli in bloody stools: identification of serogroups O26 and O111

Primers were designed to amplify sequences of verocytotoxin genes and eaeA genes of Escherichia coli O26:H11, O111:H8, and O157:H7 in a multiplex PCR assay. This assay successfully detected E. coli O26:H11 in bloody stool specimens in which other enteric pathogens were not detected by culture-based methods. Rapid assays to detect non-O157:H7 verocytotoxin-producing E. coli is important to improve methods for the etiologic diagnosis of hemorrhagic colitis.     

Orthopedic and interventional applications at low field MRI with horizontally open configuration. A review

Two monoclonal antibodies (MAbs), designated as H9 (IgG2a) and H20 (IgM), directed against heat-shock protein 60 (HSP60) of Helicobacter pylori strain TK1029 were established. Affinity-purified antigens cross-reacted in immunoblots with MAb H9 and MAb H20 respectively. These antigens also reacted with the 3C8 MAb previously established in this laboratory, which recognised Yersinia enterocolitica HSP60. By amino-acid sequence analysis, the N-terminal amino-acid sequence of the protein recognised by both H9 and H20 MAbs was confirmed as the amino-acid sequence of H. pylori HSP60 reported previously. Both MAbs reacted with nine strains of H. pylori in enzyme-linked immunosorbent assay (ELISA) and immunoblot analysis. In addition, MAb H9 reacted with extracts of other bacteria including H. mustelae, Pseudomonas aeruginosa, Vibrio cholerae, Serratia marcescens, Proteus mirabilis, Escherichia coli and Shigella sonnei. In contrast, MAb H20 reacted only with strains H. pylori. These results suggest that both the species-specific epitope recognised by MAb H20 and the common epitope recognised by MAb H9 exist on HSP60 of the bacterial cell. Both MAbs also reacted with the 60-kDa protein in the lysate of human gastric carcinoma (MKN45) cells. It was shown by immunohistochemical staining that gastric epithelial cells of four out of six biopsy specimens examined stained positively with MAb H20. These results suggest that there is a common epitope in H. pylori HSP60 and human gastric epithelial cells.     

Modulation of chromatin structure regulates cytokine gene expression during T cell differentiation

Brachytherapy boost with external radiation therapy (RT) allows safer delivery to the prostate than conventional techniques. We measured the degree of radiation effect of adenocarcinoma cells in post-RT biopsy specimens and the association with biochemical failure. Forty-six patients with T2b-3c adenocarcinomas underwent 18-month post-RT biopsies, of whom 22 had adenocarcinoma. All biopsy specimens without obvious adenocarcinoma were stained with antibodies to prostate-specific antigen and keratins AE1/AE3 and 34 beta E12. The RT effect to adenocarcinoma cells was scored by adding the scores of the nuclear and cytoplasmic changes. Each adenocarcinoma was assigned 2 scores; the most-common and the least-amount RT effect. Treatment for 7 of the 46 patients failed; 6 of these had residual adenocarcinoma on the post-RT biopsy specimen. Sixteen of 22 patients with adenocarcinoma on the post-RT biopsy specimen did not experience biochemical failure. The presence of adenocarcinoma on the post-RT biopsy specimen was significantly associated with failure. The mean most-common RT-effect score for the 16 patients without failure was 5.2 compared with 4.2 for the 6 patients with failure. The mean least-amount RT-effect score in patients without failure was 4.4 compared with 2.8 (range, 2-4; SD, 0.75) in the failure group. These relatively radiation-resistant foci may be the source of failure. Scoring the RT-effect of adenocarcinoma in post-RT biopsy specimens may be clinically useful in predicting subsequent biochemical failure.     

The value of antibodies 44-3A6, SM3, HBME-1, and thrombomodulin in differentiating epithelial pleural mesothelioma from lung adenocarcinoma: a comparative study with other commonly used antibodies

The distinction between pleural mesothelioma and peripheral pulmonary adenocarcinoma involving the pleura continues to be a diagnostic problem in surgical pathology. In recent years, the use of various immunohistochemical markers to facilitate this differential diagnosis has become common. In this study, the value of monoclonal antibodies 44-3A6, SM3, HBME-1, and thrombomodulin is compared in the differentiation of these conditions. Fifteen (68.2%) of 22, and 10 (52.6%) of 19 mesotheliomas stained positively with 44-3A6 and SM3, respectively, whereas all 23 (100%) adenocarcinomas reacted with both antibodies. Sixteen (80%) of 20 mesotheliomas and 14 (63.6%) of 22 lung adenocarcinomas reacted with HBME-1, whereas 16 (80%) of 20 mesotheliomas and only three (11.1%) of 27 adenocarcinomas were positive for thrombomodulin. Because thrombomodulin was expressed in most mesotheliomas but in only a few lung adenocarcinomas, this marker may have some diagnostic value when it is included in the standard immunohistochemical panel of markers used in the evaluation of mesotheliomas, especially when a positive marker for mesothelioma is needed. Antibodies 44-3A6, SM3, and HBME-1 have no practical value in discriminating epithelial pleural mesothelioma from lung adenocarcinoma.     

Prostate-specific membrane antigen: a novel folate hydrolase in human prostatic carcinoma cells

A novel monoclonal antibody has been developed that reacts strongly with human prostatic cancer, especially tumors of high grade. This antibody (7E11C-5) is currently in Phase 3 trials as an imaging agent for metastatic disease. We have cloned the gene that encodes the antigen that is recognized by the 7E11C-5 monoclonal antibody and have designated this unique protein prostate-specific membrane (PSM) antigen. PSM antigen is a putative class II transmembranous glycoprotein exhibiting a molecular size of Mr 94,000. Functionally, class II membrane proteins serve as transport or binding proteins or have hydrolytic activity. Preliminary studies have demonstrated binding of pteroylmonoglutamate (folate) to membrane fractions that also cross-reacted with the PSM monoclonal antibody. We observed substantial carboxypeptidase activity as folate hydrolase associated with PSM antigen. The purpose of our study was to demonstrate that human prostatic carcinoma cells expressing PSM antigen exhibit folate hydrolase activity using methotrexate triglutamate (MTXGlu3) and pteroylpentaglutamate (PteGlu5) as substrates. Isolated membrane fractions from four human prostate cancer cell lines (LNCaP, PC-3, TSU-Prl, and Duke-145) were examined for folate hydrolase activity using capillary electrophoresis. After timed incubations at various pH ranges and in the presence and absence of thiol reagents, separation of pteroyl(glutamate)n derivatives was achieved with an electrolyte of sodium borate and SDS, while absorbance was monitored at 300 nm. The results demonstrate clearly that LNCaP cells, which highly express PSM, hydrolyze gamma-glutamyl linkages of MTXGlu3. The membrane-bound enzyme is an exopeptidase, because it progressively liberates glutamates from MTXGlu3 and PteGlu5 with accumulation of MTX and PteGlu1, respectively. The semipurified enzyme has a broad activity from pH 2.5 to 9.5 and exhibits activity maxima at pH 5 and 8. Enzymatic activity is maintained in the presence of reduced glutathione, homocysteine, and p-hydroxymercuribenzoate (0.05-0.5 mm) but was inhibited weakly by DTT (>/=0.2 mm). By contrast to LNCaP cell membranes, membranes isolated from other human prostate adenocarcinoma cells (PC-3, Duke-145, and TSU-Pr1) did not exhibit comparable hydrolase activity, nor did they react with 7E11-C5 monoclonal antibody. After transfection of PC-3 cells with a full-length 2.65-kb PSM cDNA subcloned into a pREP7 eukaryotic expression vector, non-PSM antigen-expressing PC-3 cells developed immunoreactivity to 7E11-C5 monoclonal antibody and demonstrated folate hydrolase activities and optimum pH activity profiles identical to those of LNCaP cells. The membrane-bound enzymes from both LNCaP- and PC-3-transfected cells also have a capacity to hydrolyze an alpha-linked glutamyl moiety from N-acetyl-alpha-aspartylglutamate. We have identified that PSM antigen is a pteroyl poly-gamma-glutamyl carboxypeptidase (folate hydrolase) and is expressed strongly in human prostate cancer. Cancer cells that express this enzyme are resistant to methotrexate therapy. Those developing future therapeutic strategies in the treatment of prostate cancer that utilize folate antagonists need to consider this mechanism of resistance.     

q analogs of the radial Schr?dinger equation in N space dimensions

Native parvovirus B19 was used as antigen to produce a mouse monoclonal antibody, R92F6, which reacted with B19 VP1 and VP2, neutralised the virus in bone marrow culture, and labelled infected cells in paraffin-embedded tissues from cases of B19-related fetal hydrops. The B19 epitope recognised by R92F6 (amino acids 328-344 from the amino terminal region of B19 VP2) appears to be highly conserved, since these tissue specimens were obtained over a 13 year period from widely spaced locations in the UK. This epitope was synthesised as a peptide (S7b) which was used as antigen to produce a mouse monoclonal antibody, 3H8, which specifically reacted with the B19 capsid proteins VP1 and VP2 in immunofluorescence and immunoblot assays. 3H8 was also capable of labelling formalin-fixed, paraffin-embedded, B19-infected fetal tissue and was shown to be of the same isotype as R92F6 (IgG1). Highly conserved epitopes derived from conserved amino acid sequences are valuable in the diagnosis of infectious disease. If these can be recognised and accurately synthesised, the production of specific mouse monoclonal antibodies may be possible for many human pathogens. Considering the vast amount of sequence data available in the literature, this approach seems to be both feasible and of wide potential.