5E10: a prostate-specific surface-reactive monoclonal antibody

We created mAb that reacted solely with prostate epithelial cells. The strategy involved immunizing mice with a mixture of six different prostatic carcinoma cell lines and selecting by flow cytometry only those antibodies that bind whole cells. The primary screening was performed using a mixture of all six prostate cell lines used in immunization together with six non-prostate cell lines in the same tube. Antibodies that gave a bimodal pattern of surface staining were selected for further evaluation. The most attractive clone, designated 5E10, produced IgG1 mAb that recognized four of the six prostatic cell lines and did not react with non-prostate tumor cell lines, peripheral blood and bone marrow mononuclear cells and endothelial and bone marrow stromal cells. 5E10 mAb reacted with both benign and malignant prostate in eight of eight histological samples and no reactivity was noted with non-prostate normal tissues. The 5E10 antigen is a transmembrane glycoprotein with a molecular weight of 110 kDa and the epitope recognized by 5E10 is extracellular. Ongoing studies are exploring the nature of this antigen in more depth.

Rhabdomyosarcoma presenting as a parotid gland mass in pediatric patients: fine-needle aspiration biopsy findings

BACKGROUND

The head and neck region is one of the most common locations of rhabdomyosarcoma. Salivary gland involvement is usually secondary to advanced disease, and presentation as a primary salivary gland tumor is very rare.

METHODS

Three cases of rhabdomyosarcoma presenting as parotid masses, in 2 boys (ages 3 and 7 years) and a girl (age 5 years), were retrieved from the files of 2 institutions.

RESULTS

The three patients presented with parotid gland enlargement. Clinically, the enlargements appeared to be inflammatory, and they were treated unsuccessfully with antibiotics. Fine-needle aspiration biopsy (FNAB) was performed on all three patients. The cytologic features varied from one case to another; one case had features of a small round cell tumor, another was composed of a monomorphic population of spindle cells in a metachromatic stroma, and the third case was composed mostly of spindle cells with moderate cellular pleomorphism. Immunohistochemical studies performed in two of the cases confirmed the diagnosis of rhabdomyosarcoma, and ultrastructural studies were confirmatory in the other case. The patients are alive; 2 of them have had no evidence of disease after 6 and 9 years of follow-up, and the third, the most recent patient, has just finished adjuvant chemotherapy.

CONCLUSIONS

With the increased use of FNAB for the evaluation of salivary gland masses in children, the authors believe that it is important to recognize the occurrence of rhabdomyosarcoma in this location. Immunohistochemical studies have proved helpful in differentiating rhabdomyosarcoma from other parotid gland tumors and can be readily done on cytologic preparations.

Cytology of metastatic cutaneous basal cell carcinoma

Although basal cell carcinoma is the most common malignant skin tumor, it rarely metastasizes. Because of the infrequency of basal cell carcinoma metastases, the cytomorphologic findings have not been well documented. We retrospectively reviewed the cytologic findings of six cases of metastatic basal cell carcinoma from two patients. Five of these specimens were fine-needle aspiration biopsies, and one was a bronchial brush specimen. All cases were confirmed by and compared to either the concurrent tissue biopsy or to a previous surgical specimen. The microscopic findings of these specimens reveal tight clusters of cells with high nuclear to cytoplasmic ratio. The nuclei were crowded and overlapping, and on Diff Quik stain, peripheral palisading of nuclei could be appreciated. The small hyperchromatic nuclei were round to oval with finely granular chromatin. Nucleoli were inconspicuous. Basophilic cytoplasm was scant with indistinct borders. Cytologic findings of basal cell carcinoma have not been well documented in the English literature. Our experience suggests that there are unique cytormorphologic features of metastatic basal cell carcinoma and that in the right setting such a diagnosis can be rendered.

Bone tumor radiograph review by pathologists prior to pathologic diagnosis: a receiver operator curve analysis of diagnostic utility

Radiologic-pathologic correlation has long been considered a prerequisite for the accurate diagnosis of bone lesions. We investigated using receiver-operating characteristic analysis the accuracy of histopathologic diagnoses with and without pathologist review of radiographs. While accuracy of diagnosis did improve when the radiographs were reviewed by the pathologist, this increase did not reach statistical significance (P=0.1311). Potential reasons for this finding including case selection and reviewer expertise are discussed. Based on our study, the review of radiographs did not result in a statistically significant difference in accuracy of the pathologic diagnosis of bone tumors. However, our data suggest that there may be a difference particularly in selected cases and among certain observers.

Validation of a volunteer model of cholera with frozen bacteria as the challenge

To evaluate a standardized inoculum of Vibrio cholerae for volunteer challenge studies, 40 healthy adult volunteers were challenged at three different institutions with a standard inoculum prepared directly from vials of frozen, virulent, El Tor Inaba V. cholerae N16961, with no further incubation. Groups of 5 volunteers, with each group including 2 volunteers with blood group O, were given a dose of 10(5) CFU, and 34 of the 40 volunteers developed diarrhea (mean incubation time, 28 h). Transient fevers occurred in 15 (37.5%) of the volunteers. V. cholerae was excreted by 36 of 40 volunteers. Five additional volunteers received 10(4) CFU, and four developed diarrhea but with a lower average purging rate than required for the model. Of the 40 volunteers, 37 developed rises in their vibriocidal and antitoxin titers similar to those in previous groups challenged with freshly harvested bacteria. We conclude that challenge with frozen bacteria results in a reproducible illness similar to that induced by freshly harvested bacteria. Use of this model should minimize differences in attack rates or severity when groups are challenged at different times and in different institutions.

Is the cytologic diagnosis of esophageal glandular dysplasia feasible?

Barrett's esophagus is a premalignant condition in which the normal stratified squamous epithelium of the esophagus is replaced by metaplastic glandular epithelium. Patients with Barrett's esophagus are at increased risk for the development of esophageal adenocarcinoma. Because dysplasia precedes the development of frank adenocarcinoma, the cytologic detection of esophageal glandular dysplasia represents a potentially inexpensive and efficient means of monitoring disease progression to adenocarcinoma and identifying high-risk patients. This article discusses the current status of exfoliative cytology as a screening test for glandular dysplasia of the esophagus.

Guanylin mRNA expression in human intestine and colorectal adenocarcinoma

Guanylin is a mammalian peptide ligand that binds to the enterocyte receptor guanylyl cyclase C and mediates Cl- and HCO3- efflux via the cystic fibrosis transmembrane conductance regulator. To identify the regional localization of guanylin mRNA in the human intestine, we performed in situ hybridization using a guanylin-specific riboprobe. The pattern of guanylin mRNA distribution is complex and includes all epithelial lineages at various points along the duodenal-to-colonic axis. Guanylin mRNA expression is most prominent in the distal small intestine and colon. In the normal colon, guanylin mRNA is robustly expressed in superficial epithelial cells; in colorectal adenocarcinoma, however, guanylin mRNA expression is absent. Guanylin mRNA is detectable in several intestinal tumor cell lines, although at much lower levels than those seen in the human intestine. The pattern of guanylin expression is consistent with the possibility of region-specific functions for guanylin within the human intestine. Furthermore, the diminished expression of guanylin mRNA in adenocarcinoma of the colon and in colon cancer cell lines, along with the chromosomal localization of guanylin to the tumor modifier region 1p34-35, raises the possibility that loss of guanylin activity leads to or is a result of adenocarcinoma formation.

Prostatic duct adenocarcinoma: a cytologic and histologic case report with review of the literature

Prostatic duct adenocarcinoma is a rare tumor which typically involves the prostatic urethra as its primary site. Due to this unique location, prostatic duct adenocarcinoma may shed cells into urine specimens which may be detected by cytologic techniques. This report describes the cytologic and histologic features of a case of prostatic duct adenocarcinoma involving the prostatic urethra. Key features which differentiate this neoplasm from the more common transitional carcinomas and the potentially confounding prostatic acinar adenocarcinomas include epithelial clusters with prominent nuclear overlap and nuclear grooves. A comparison to the five previously reported cases is presented.

The uroguanylin gene (Guca1b) is linked to guanylin (Guca2) on mouse chromosome 4

Uroguanylin is an endogenous ligand of the intestinal receptor guanylate cyclase-C (GC-C). Both uroguanylin and the related peptide ligand guanylin bind to GC-C and stimulate an increase in cyclic GMP, inducing chloride secretion via the cystic fibrosis transmembrane conductance regulator. We describe the cloning of the complete mouse uroguanylin gene (Guca1b) and show that Guca1b is tightly linked to the mouse guanylin gene on chromosome 4. The two genes are structurally similar, being composed of three short exons; the uroguanylin gene spans 2.4 kb and the guanylin gene spans 1.7 kb. Uroguanylin mRNA is most prominent in proximal small intestine, whereas guanylin mRNA is predominantly expressed in distal small intestine and colon. The upstream promoter sequence of the mouse uroguanylin gene contains a canonical TATA element at the site of transcription initiation and consensus binding sites for several known transcription factors, including HNF-1 and Sp1 within the first 1 kb. Although the gene structure and coding sequences of uroguanylin and guanylin are similar, the 5' flanking sequences and patterns of expression of these two genes in the intestine are different. It is likely that uroguanylin and guanylin represent gene duplications that have evolved to allow overlapping and complementary patterns of expression in the intestine.

Measurement of 2,4-toluenediamine in urine and serum samples from women with Même or Replicon breast implants

The objective of this matched case-control study was to determine whether women with Même or Replicon polyurethane-covered silicone breast implants are exposed to clinically significant levels of free 2,4-TDA from biodegradation of the polyurethane foam. Urine and serum samples were obtained from 61 patients with Même or Replicon breast implants and 61 controls on two separate occasions separated by 10 +/- 3 days. Free TDA was analyzed by gas chromatography combined with negative chemical ionization mass spectrometry with lower limit of quantitation in both urine and serum of 10 pg/ml. The results were correlated with the length of time since implantation. No patients or controls had detectable free 2,4-TDA in their sera. Thirty patients had quantifiable levels of free 2,4-TDA, and 18 had detectable levels in their urine. Controls had no quantifiable levels, but 7 subjects had detectable levels. The biodegradative half-life of the polyurethane foam was estimated to be 2 years. A risk assessment using the cancer potency estimate calculated by the FDA from rat data and the National Academy of Sciences methodology provided a theoretical lifetime risk of approximately one in one million. It was concluded that the polyurethane foam cover on the Même and Replicon breast implants biodegrades. The risk assessment of approximately one in one million derived from this study strengthens earlier conclusions by the Health Protection Branch (Canada) that there is no significant risk of cancer from exposure to the 2,4-TDA formed from this biodegradation.

Significant reduction in the rate of false-negative cervical smears with neural network-based technology (PAPNET Testing System)

False-negative cervical Pap smears may lead to disability or death from carcinoma of the uterine cervix. New computer technology has led to the development of an interactive, neural network-based vision instrument to increase the accuracy of cervical smear screening. The instrument belongs to a new class of medical devices designed to provide computer-aided diagnosis (CADx). To test the instrument's performance, 487 archival negative smears (index smears) from 228 women with biopsy-documented high-grade precancerous lesions or invasive cervical carcinoma (index women) were retrieved from the files of 10 participating laboratories that were using federally mandated quality assurance procedures. Samples of sequential negative smears (total 9,666) were retrieved as controls. The instrument was used to identify evidence of missed cytological abnormalities, including atypical squamous or glandular cells of undetermined significance (ASCUS, AGUS), low-grade or high-grade squamous intraepithelial lesions (LSIL, HSIL) and carcinoma. Using the instrument, 98 false-negative index smears were identified in 72 of the 228 index women (31.6%, 95% confidence interval [CI]: 25% to 38%). Disregarding the debatable categories of ASCUS or AGUS, there were 44 women whose false-negative smears disclosed squamous intraepithelial lesions (SIL) or carcinoma (19.3%; 95% CI: 14.2% to 24.4%). Unexpectedly, SILs were also identified in 127 of 9,666 control negative smears (1.3%; 95% CI: 1.1% to 1.5%). Compared with historical performance data from several participating laboratories, the instrument increased the detection rate of SILs in control smears by 25% and increased the yield of quality control rescreening 5.1 times (P < 0.0001). These data provide evidence that conventional screening and quality control rescreening of cervical smears fail to identify a substantial number of abnormalities. A significant improvement in performance of screening of cervical smears could be achieved with the use of the instrument described in this report.

Hepatocyte nuclear factor-1alpha regulates transcription of the guanylin gene

To study the molecular mechanisms controlling guanylin expression, we have cloned the mouse guanylin gene, including 2.7 kb of upstream sequence. We show that the first 133 base pairs (bp) of the upstream guanylin promoter are sufficient to drive near maximal (6-fold over basal) luciferase reporter gene expression in Caco-2 intestinal cells; at least 300 bp of upstream promoter are required for reporter gene expression in HT-29 intestinal cell lines. Using electromobility shift assays, we demonstrate that nuclear proteins bind to the hepatocyte nuclear factor-1 (HNF-1) consensus sequence in the guanylin promoter. The HNF-1 consensus sequence, located in the immediate 5' flanking region, is required for transcriptional activation of the guanylin gene in both intestinal cell lines. Mutagenesis of the HNF-1 consensus sequence abolishes transcriptional activation of guanylin promoter-luciferase reporter gene constructs. Cotransfection of these constructs with HNF-1alpha augments transcriptional initiation of the reporter gene. In contrast, HNF-1beta has no significant effect on transcription of the reporter gene. These experiments demonstrate that HNF-1alpha is an important regulatory element in the transcriptional activation of guanylin.

Dominant nature of the resistance to Fas- and tumor necrosis factor-alpha-mediated apoptosis in human prostatic carcinoma cell lines

We have recently found (O. W. Rokhlin et al., Cancer Res., 57: 1758-1768, 1997) that, although Fas ligation induced apoptosis in two of six human prostatic carcinoma cell lines investigated, the apoptotic machinery involved in Fas-mediated killing is already in place in Fas-resistant cell lines. Here, we investigated Fas- and tumor necrosis factor-alpha (TNF-alpha)-mediated apoptosis in cell hybrids between resistant (DU145 and JCA1) and sensitive (ALVA31 and PC3) cell lines. All three types of hybrid cells investigated, F1(DU145 x PC3), F1(JCA1 x PC3), and F1(JCA1 x ALVA31), were found to be resistant to Fas- and TNF-alpha-mediated apoptosis at the same level as the corresponding parental resistant cell lines. These results indicate that resistance to Fas- and TNF-alpha-mediated apoptosis dominates over sensitivity in cell hybrids and suggest that resistance may be regulated by an apoptosis suppressor factor or factors acting in resistant but not in sensitive cells.

Uroguanylin and guanylin: distinct but overlapping patterns of messenger RNA expression in mouse intestine

BACKGROUND & AIMS

Uroguanylin and guanylin, endogenous ligands of the guanylate cyclase C receptor, are presumed to mediate fluid and electrolyte secretion in the intestine. The aim of this study was to characterize the expression patterns of uroguanylin and guanylin messenger RNA (mRNA) in the mouse intestine.

METHODS

A mouse uroguanylin complementary DNA was amplified from a partial genomic clone, and Northern analyses and in situ hybridization were performed to localize guanylin and uroguanylin mRNA along the duodenal-colonic and crypt-villus axes.

RESULTS

Uroguanylin mRNA was expressed throughout the mouse intestine and also in the kidney. Signal intensity was greatest in the small intestine for uroguanylin and in the distal small intestine and colon for guanylin. In situ hybridization showed uroguanylin mRNA localized predominantly in intestinal villi and the corticomedullary junction of the kidney, whereas guanylin mRNA was localized in both crypts and villi in the small intestine and to superficial epithelial cells in the colon.

CONCLUSIONS

Mouse uroguanylin mRNA expression is discrete from guanylin expression in the intestine. The patterns of distribution in the intestine and the known pH optima of these ligands suggest a complementary role for these secretagogues.

Expression of antioxidant enzymes in human prostatic adenocarcinoma

BACKGROUND

Antioxidant enzymes (AEs), which catalyze the conversion of reactive oxygen species (ROS) to water, include catalase (CAT), manganese-containing superoxide dismutase (MnSOD), and copper and zinc-containing superoxide dismutase (CuZnSOD). Previous work has indicated that MnSOD, CAT, and CuZnSOD levels are nearly always low in cancer cells.

METHODS

Formalin-fixed, paraffin-embedded tissue from 31 radical prostatectomy specimens was immunohistochemically stained with polyclonal antibodies to CAT, MnSOD, and CuZnSOD.

RESULTS

Malignant glands are typically stained with less intensity than benign/ hyperplastic glands. Marked heterogeneity of staining intensity was seen in the malignant glands for each of the three enzymes. A similar, though less marked, spectrum of heterogeneity of staining intensity was observed in the benign/hyperplastic epithelium contained in the specimens. No statistically significant correlation was found between intensity of staining for any of the three antioxidant enzymes and Gleason score, tumor stage, or preoperative prostate-specific antigen (PSA).

CONCLUSIONS

Cellular levels of CAT, MnSOD, and CuZnSOD in prostatic adenocarcinoma reveal that many tumors appear to have decreased levels of expression. The finding that malignant prostate epithelium may have lowered expression of AEs suggests that further study of the role of AEs in malignant transformation in the prostate is warranted.

Fine structural studies of induced tumors arising within the prostatic complex of Lobund-Wistar rats

BACKGROUND

Morris Pollard, Phyllis Luckert, and colleagues have reported the occurrence of spontaneously arising tumors of the prostatic complex in aged Lobund-Wistar (L-W) rats, and have also shown that the genesis of such tumors may be accelerated by means of intravenous administration of methylnitrosourea, followed by androgen supplementation.

METHODS

Light and electron microscopic investigations of the tumors arising under this regime were conducted, with the objective of documenting morphological changes attending the transformation process; 10 tumor samples were used for the electron microscopic studies.

RESULTS

All tumors studied were adenocarcinomas arising within the prostatic complex of induced animals. These tumors varied in size, degree of differentiation, and invasiveness. Foci of prostatic intraepithelial neoplasia were noted in light microscopic studies as well. Consistent fine structural features exhibited by cells of the induced adenocarcinomas included a large nuclear to cytoplasmic ratio; large irregular nuclei with heavily marginated chromatin; conspicuous nucleoli; abundant ribosomes and polysomes and a paucity of rough endoplasmic reticulum; and numerous cytoplasmic vesicles and lipid inclusions. Numerous, short microvilli extended from the cell surface into a copious surrounding extracellular matrix.

CONCLUSIONS

Thus, these tumors shared many of the fine structural features characteristic of the Dunning (rat) and human prostatic adenocarcinomas.