Bladder epithelium is abnormal in patients with neurogenic bladder due to myelomeningocele

OBJECTIVE

To describe the urothelium of the neurogenic bladder in patients with myelomeningocele on clean intermittent catheterization.

SETTING

Outpatient practice.

METHODS

Samples of bladder wall obtained from two groups of patients were examined for urothelium. The first group included 12 children and young adults with myelomeningocele and neurogenic bladder on intermittent catheterization for bladder emptying. The second group included eight children with vesicoureteral reflux and non-neurogenic bladder. Nine patients from the first group and four patients from the second group had urothelium. A contiguous section of each of the 13 samples with urothelium was stained for uroplakin expression, a marker of superficial bladder urothelium by immunohistochemistry.

RESULTS

Samples from children with reflux revealed normal bladder epithelium and a uniform layer of umbrella cells (95% CI: 0-60%). In contrast, the epithelium from all patients with myelomeningocele was abnormal (95% CI: 66-100%). Epithelium from five patients (four children, one adult) revealed chronic inflammation. Three patients (two children, one adult) had squamous metaplasia. The apical surface of the epithelium in all patients with chronic inflammation had some reactivity with anti-uroplakin antibody, but the cells staining positive for uroplakin were scattered along the lumenal surface of the epithelium. The apical surface of patients with squamous metaplasia was negative for uroplakin.

CONCLUSION

The urothelium of the neurogenic bladder in young patients with myelomeningocele is abnormal, with loss of uroplakin expression and altered urothelial proliferation.

Beta-adrenergic receptor subtypes that mediate ractopamine stimulation of lipolysis

Ractopamine HCl is an beta-adrenergic receptor (betaAR) ligand that was recently approved for use in swine to enhance carcass leanness. The RR stereoisomer of ractopamine is the most active of the four stereoisomers exhibiting the highest affinity and signaling response. The RR isomer exhibits selective activation of the porcine beta2AR, which might limit the lipolytic response to ractopamine because the betaAR is the predominant subtype in swine adipocytes and may mediate most of the lipolytic response. Therefore, we determined the betaAR subtypes that mediate the lipolytic response to ractopamine in swine adipocytes. In order to confirm the predominant role of the beta1AR in porcine adipocytes, isoproterenol-stimulated lipolysis was inhibited by increasing doses of subtype-selective antagonists. Inhibition curves were biphasic using beta1AR antagonists (CGP 20712A and bisoprolol) and curve analysis indicated that both beta1AR an beta2AR contributed to lipolysis with 50 to 60% of the response coming from the beta1AR. Inhibition with the beta2AR antagonist clenbuterol revealed only one class of betaAR that closely approximated the kinetics of the beta1AR. When the RR isomer of ractopamine was the lipolytic agent, similar results to isoproterenol were observed, except that the estimated contribution of the beta1AR was 38%. That beta2AR antagonists did not detect a contribution of the beta2AR to lipolysis may indicate that the beta1AR masked the response to the beta2AR. Dose titration with the RR isomer in the presence of a saturating concentration of beta1AR or beta2AR antagonists indicated that each subtype was present in sufficient quantities to stimulate lipolysis near maximally. Data indicate that both the beta1AR and beta2AR are functionally linked to lipolysis in swine adipocytes and that ractopamine activates each subtype. The RR isomer of ractopamine stimulated adenosine 3',5'-cyclic phosphate accumulation with equal efficacy to isoproterenol through the cloned porcine beta2AR, but was only 35% as efficacious through the cloned porcine beta1AR. These data confirm the beta2AR selectivity of the RR stereoisomer, but suggest the partial agonism through the beta1AR is sufficient to activate lipolysis through both subtypes in swine adipocytes.

Stereoselectivity of porcine beta-adrenergic receptors for ractopamine stereoisomers

Ractopamine HCl is a beta-adrenergic receptor ((betaAR) ligand approved for use in swine to enhance carcass leanness. Ractopamine is produced commercially as a mixture of four stereoisomers (RR, RS, SR, SS). In order to determine which stereoisomers are active in the pig and whether they exhibit betaAR subtype selectivity, receptor affinity and adenylyl cyclase activation were determined using cloned porcine beta1- and beta2AR expressed in Chinese hamster ovary (CHO) cells. Dissociation constants (Kd) were determined by competitive displacement of [125I]iodocyanopindolol binding by ractopamine stereoisomers. The RR isomer had the highest affinity for both beta1- and betaAR (Kd of 29 and 26 nM, respectively). Dissociation constants for the other stereoisomers were higher (RS = 463 and 78 nM, SR = 3,230 and 831 nM, SS = 16,600 and 3,530 nM for the beta1- and beta2AR, respectively) relative to the RR stereoisomer. Isoproterenol stimulated adenylyl cyclase activity 600% relative to basal rates in CHO cells, regardless of betaAR subtype. Ractopamine stereoisomers did not significantly (P > 0.05) stimulate adenylyl cyclase through the beta1AR at moderate (near Kd) or high (10(-4) M) concentrations. In contrast, the RR isomer increased adenylyl cyclase activity 200 to 300% relative to basal rates through the beta2AR at moderate and hiconcentrations; the SR stereoisomer increased adenylyl cyclase activity nearly 100%. Neither the RS nor SS stereoisomers were effective in activating adenylyl cyclase activity through the beta2AR. A pattern of stereoselective activation similar to that for adenylyl cyclase also was exhibited for lipolysis using porcine adipocytes. The RR stereoisomer was equal to isoproterenol in stimulating lipolysis, whereas the SR isomer was 50% as effective; the RS and SR stereoisomers did not stimulate lipolysis in porcine adipocytes. The porcine betaAR exhibited stereoselectivity toward ractopamine stereoisomers with the RR isomer exhibiting the highest affinity for the (beta1- and beta2AR. In contrast, ractopamine stereoisomers seemed to be more effective at eliciting adenosine cyclic 3',5'-phosphate responses from beta2AR than beta1AR. The RR isomer ilikely the functional stereoisomer of ractopamine, but its effectiveness may be compromised by the presence of competing isomers, in particular the RS stereoisomer.

Quantitative analysis of beta-adrenergic receptor subtypes in pig tissues

The density and distribution of beta1- and beta2-adrenergic receptors (betaAR) in porcine adipocytes, skeletal muscle, heart, lung, and liver were investigated using competitive displacement of ligand binding with subtype-selective ligands. Three experimental approaches were used to estimate the distribution of betaAR subtypes in adipocytes. Two approaches involved simultaneous linear regression analysis of multiple competitive displacement curves with the beta1AR-selective antagonist CGP 20712A and the beta2AR-selective ligand BRL 37344. For the third approach, radioligand saturation assays were perfomed using a concentration of CGP 20712A that completely blocked the beta1AR. All three approaches indicated the presence of multiple betaAR subtypes in porcine adipocytes and gave similar estimates for the proportion of these subtypes. Saturation assays in the presence of the beta1AR blocker CGP 20712A were conducted to determine the distribution of the betaAR subtypes in skeletal muscle, heart, lung, and liver. The proportions of the beta1AR and beta2AR were 81:19, 59:41, 72:28, 58:42, and 50:50 for adipose, skeletal muscle, heart, lung, and liver, respectively. These estimates based on receptor protein were consistent with published estimates of mRNA abundance in pig tissues but differ from estimates for other species. The predominance of beta1AR in adipocytes and skeletal muscle may contribute to the reduced efficacy of select betaAR agonists in pigs compared to other species because most of the ligands evaluated in growth studies are purported to be beta2AR selective. The density of the betaAR varied among tissues in the following order: heart = lung > adipocytes > skeletal muscle or = liver.

Neuroendocrine neoplasms of the lung

Neuroendocrine tumors of the lung continue to be difficult nosologic and diagnostic problems, centering on the time-honored terms of "carcinoid," "atypical carcinoid," and "small cell carcinoma." Problems that are encountered in the classification of such neoplasms revolve around the differing criteria that have been advanced for their definition and variable application of such criteria in common practice. This review considers the epithelial and nonepithelial lesions of the lung that may demonstrate neuroendocrine and neuroectodermal differentiation. A proposal is made for a simplified system of classifying the epithelial tumors, dividing them into 3 grades with appended descriptive modifiers.

Effects of conjugated linoleic acid on the belly firmness and fatty acid composition of genetically lean pigs

A study of the effects of conjugated linoleic acid (CLA) on the belly firmness and fatty acid composition of genetically lean pigs was conducted. From 75 to 120 kg live weight, 30 gilts were allowed ad libitum access to a corn-soybean meal diet supplemented with either 1% CLA oil (CLA-60) or 1% sunflower oil (SFO) or were fed the sunflower oil-supplemented diet restricted to the amount consumed by pigs fed the CLA-60 diet (RSFO). Conjugated linoleic acid oil consists of 60% positional and geometric isomers of CLA. Pigs fed SFO exhibited higher average daily gains (0.98 vs 0.80 kg/d, P < 0.01) than RSFO-fed pigs, but there were no effects of dietary treatment on feed intake or feed efficiency. Dietary treatment did not affect (P > 0.05) backfat thickness or longissimus muscle area. Bellies of gilts fed CLA-60 were subjectively evaluated to be firmer (2.91 vs 2.43 or 2.07 +/- 0.13, P < 0.01) than those of SFO- or RSFO-fed gilts, respectively. The longissimus muscle of gilts fed CLA-60 contained more saturated fatty acids (39.77 vs. 36.04 or 36.73 +/- 0.74%, P < 0.001) and less unsaturated fatty acids (60.23 vs 63.96 or 63.27 +/- 0.74%, P < 0.001) than that of gilts fed SFO or RSFO, respectively. The belly fat of gilts fed CLA-60 contained more saturated fatty acids (44.45 vs. 37.50 or 36.60 +/- 0.46%, P < 0.001) and less unsaturated fatty acids (54.78 vs. 61.75 or 62.47 +/- 0.46%, P < 0.001), resulting in lower iodine values (57.69 vs 66.37 or 65.62 +/- 0.91, P < 0.001) than that of gilts fed SFO or RSFO, respectively. Gilts fed CLA-60 accumulated more CLA in the longissimus muscle (0.55 vs 0.09 or 0.09 +/- 0.03%, P < 0.01) and belly fat (1.56 vs. 0.13 or 0.13 +/- 0.15%, P < 0.001) than did gilts fed SFO or RSFO, respectively. Dietary treatment did not affect (P > 0.05) 24-h pH, drip loss or subjective quality evaluations of the longissimus muscle. The effect of supplemental CLA to improve belly firmness is of practical significance and may provide a nutritional solution to carcass fat and belly firmness problems, thereby enhancing the overall value of extremely lean carcasses.

Immunohistochemical differential diagnosis of pleural effusions, with emphasis on malignant mesothelioma

The immunohistochemical diagnosis of atypical epithelial proliferations in pleural fluid is a challenging topic in cytopathology and surgical pathology. Mesothelioma may be simulated clinically and radiologically by several other nonneoplastic and neoplastic disorders, mandating that strict histologic, histochemical, immunohistochemical, and ultrastructural guidelines be followed for its diagnosis. Because of its availability to most laboratories, immunohistochemistry has emerged as the most commonly used procedure for the diagnosis of pleural malignancies. This review considers the current status of that investigative modality, with particular attention to lesions that are suspected to be mesothelial.

Mucoepidermoid carcinoma: a clinicopathologic study of 80 patients with special reference to histological grading

We sought to review our experience with salivary mucoepidermoid carcinoma (MEC) over two decades to confirm the validity and reproducibility of histologic grading and to investigate MIB-1 index as a prognosticator. Diagnosis was confirmed on 80 cases, and chart review or patient contact was achieved for 48 patients, with follow-up from 5 to 240 months (median 36 months). Immunohistochemistry with citrate antigen retrieval for MIB-1 was performed on a subset of cases. Kaplan-Meier survival curves were generated for each stage, site, and grade according to our proposed grading system. To address the issue of grading reproducibility, 20 slides were circulated among five observers, without prior discussion; slides were categorized as low-, intermediate-, or high-grade according to one's "own" criteria, and then according to the AFIP criteria proposed by Goode et al.10 Weighted kappa (kappa) estimates were obtained to describe the extent of agreement between pairs of rating. The Wilcoxon signed rank test or the Friedman test as appropriate tested variation across ratings. There was no gender predominance and a wide age range (15-86 years, median 49 years). The two most common sites were parotid and palate. All grade 1 MECs presented as Stage I tumors, and no failures were seen for this category. The local disease failure rates at 75 months for grades 2 and 3 MEC were 30% and 70%, respectively. Tumor grade, stage, and negative margin status all correlated with disease-free survival (DFS) (p = 0.0091, 0.0002, and 0.048, respectively). The MIB index was not found to be predictive of grade. Regarding the reproducibility of grading, the interobserver variation for pathologists using their "own" grading, as expressed by the kappa value, ranged from good agreement (kappa = 0.79) to poor (kappa = 0.27) (average kappa = 0.49). A somewhat better interobserver reproducibility was achieved when the pathologists utilized the standardized AFIP criteria (average kappa = 0.61, range 0.38-0.77). This greater agreement was also reflected in the Friedman test (statistical testing of intraobserver equality), which indicated significant differences in using one's own grading systems (p = 0.0001) but not in applying the AFIP "standardized" grading (p = 0.33). When one's own grading was compared with the AFIP grading, there were 100 pairs of grading "events," with 46 disagreements/100 pairs. For 98% of disagreements, the AFIP grading "downgraded" tumors. This led us to reanalyze a subset of 31 patients for DFS versus grade, for our grading schema compared with the AFIP grading. Although statistical significance was not achieved for this subset, the log rank value revealed a trend for our grading (p = 0.0993) compared with the Goode schema (p = 0.2493). This clinicopathologic analysis confirms the predictive value of tumor staging and three-tiered histologic grading. Our grading exercise confirms that there is significant grading disparity for MEC, even among experienced ENT/oral pathologists. The improved reproducibility obtained when the weighted AFIP criteria were used speaks to the need for an accepted and easily reproducible system. However, these proposed criteria have a tendency to downgrade MEC. Therefore, the addition of other criteria (such as vascular invasion, pattern of tumor infiltration [i.e., small islands and individual cells vs cohesive islands]) is necessary. We propose a modified grading schema, which enhances predictability and provides much needed reproducibility.

The structures of anthranilate synthase of Serratia marcescens crystallized in the presence of (i) its substrates, chorismate and glutamine, and a product, glutamate, and (ii) its end-product inhibitor, L-tryptophan

The crystal structure of anthranilate synthase (AS) from Serratia marcescens, a mesophilic bacterium, has been solved in the presence of its substrates, chorismate and glutamine, and one product, glutamate, at 1.95 A, and with its bound feedback inhibitor, tryptophan, at 2.4 A. In comparison with the AS structure from the hyperthermophile Sulfolobus solfataricus, the S. marcescens structure shows similar subunit structures but a markedly different oligomeric organization. One crystal form of the S. marcescens enzyme displays a bound pyruvate as well as a putative anthranilate (the nitrogen group is ambiguous) in the TrpE subunit. It also confirms the presence of a covalently bound glutamyl thioester intermediate in the TrpG subunit. The tryptophan-bound form reveals that the inhibitor binds at a site distinct from that of the substrate, chorismate. Bound tryptophan appears to prevent chorismate binding by a demonstrable conformational effect, and the structure reveals how occupancy of only one of the two feedback inhibition sites can immobilize the catalytic activity of both TrpE subunits. The presence of effectors in the structure provides a view of the locations of some of the amino acid residues in the active sites. Our findings are discussed in terms of the previously described AS structure of S. solfataricus, mutational data obtained from enteric bacteria, and the enzyme's mechanism of action.

Impact of second opinion pathology in the definitive management of patients with bladder carcinoma

BACKGROUND

The accurate diagnosis, staging, and grading of bladder neoplasms depend heavily on the interpretation of biopsies and transurethral resection (TUR) specimens. Although many centers require review of outside pathologic material before definitive treatment such as radical cystectomy, the authors are unaware of data supporting the utility of this approach in urothelial (transitional cell) carcinoma. The authors therefore examined the clinical and cost impact of pathologic review on patients referred to an academic urology department for treatment of bladder neoplasia.

METHODS

The pathologic material from 97 patients referred to an academic center for evaluation of urothelial carcinoma of the bladder from July 1996 to July 1999 was reviewed. This material was received from 30 community hospitals and 4 academic centers. The 97 patients had undergone 131 (mean, 1.35; range, 1-10) biopsies or TUR procedures before referral. Surgical pathologists at the authors' institution reviewed all outside patient material, and discordant cases were rereviewed by one of the authors (S.E.M), an experienced genitourinary pathologist. Follow-up chart review was performed in discordant cases to determine clinical and pathologic outcomes.

RESULTS

Upon review at the authors' institution, 24 of 131 (18%) specimens with a referring diagnosis of urothelial carcinoma exhibited significant discrepancies with regard to the diagnosis, stage, grade, or tumor histologic type made at the outside institution. Four tumors (3%) were found to be nonurothelial neoplasms. Five specimens (4%) were judged inadequate for staging because they contained no muscularis propria. Three patients were upstaged, including two patients shown to have muscle invasive disease. Eight patients were downstaged, including two patients referred with purported muscle invasive disease who were determined to have only superficial disease on pathology review. Two patients initially thought to have carcinoma in situ (tumor in situ [Tis]) showed no evidence of Tis on pathology review. One patient with purported muscle invasive disease was shown to have only metaplasia, and one patient had a highly significant change in tumor grade. As a result of the pathology review, five radical cystectomies were avoided, whereas five repeat TUR procedures were recommended for inadequate staging. One patient shown to have muscle invasion on pathology review proceeded directly to cystectomy, avoiding a planned repeat TUR. A cystectomy also was recommended to a second patient who was shown to have invasive disease by the pathology review. Pathology review of 131 specimens resulted in net savings of $86,176 or $658 per TUR reviewed.

CONCLUSIONS

The review of bladder pathologic materials before definitive therapy can impact clinical decisions significantly and can reduce overall expenditures for the management of this cohort of bladder carcinoma patients.

Sinonasal undifferentiated carcinoma: immunohistochemical profile and lack of EBV association

The role of Epstein-Barr virus (EBV) in the development of sinonasal undifferentiated carcinoma (SNUC) remains unresolved. Reports of EBV-positivity in SNUC may reflect inclusion of lymphoepithelioma-like carcinomas within this group. In addition, SNUC have been incompletely characterized immunohistochemically, and their undifferentiated appearance often requires such ancillary studies to aid in their distinction from other high-grade neoplasms. To address these two issues, 25 cases of SNUC diagnosed between the years 1983 and 1999 were selected from our files. EBER in situ hybridization (ISH) was performed on the paraffin-embedded tissue by using 3H-labeled EBER-1 RNA probes. Neoplasms with sufficient tissue (22 of 25) were evaluated immunohistochemically for Ki-67, p53, chromogranin, synaptophysin, placental alkaline phosphatase (PLAP), CD99, carcinoembryonic antigen (CEA), epithelial membrane antigen (EMA), neuron-specific enolase (NSE), and latent membrane protein-1 (LMP-1). The median patient age was 58 years (range, 20-81 years), with a male-to-female ratio of approximately 3:1. The most common tumor location was the nasal cavity (18 cases), followed by the ethmoid and maxillary sinuses. Median survival was 18 months. All 25 tumors were negative for EBER-I by ISH. Ki-67 was negative in one case, 1+ in nine, 2+ in six, 3+ in five, and 4+ in one. P53 was negative in nine, 1+ in five, 2+ in two, 3+ in none, and 4+ in six. CD99 expression was strongly positive in 3 of 22 (14%) and completely negative in the remainder. Variably intense focal staining for EMA was present in 4 of 22 (18%). NSE faintly stained 4 of 22 (18%). Chromogranin, synaptophysin, PLAP, CEA, and LMP-1 were negative (0 of 22). Our results suggest that EBV does not play a role in the development of SNUC. Strict histologic criteria are necessary to avoid confusion with lymphoepithelioma-like carcinoma or other high-grade malignancies in this region. The finding of occasional CD99-positive cases adds SNUC to the growing list of CD99-positive neoplasms.

Nonneoplastic endometrial signet-ring cells. Vacuolated decidual cells and stromal histiocytes mimicking adenocarcinoma

We describe 5 patients (mean age, 50 years; all had uterine bleeding) whose routine endometrial biopsy and curettage specimens contained prominent signet-ring cells. Each specimen contained loose aggregates of signet-ring cells scattered within the endometrial stroma that were characterized by peripherally displaced, small, uniform nuclei with indistinct nucleoli and showed no mitotic activity. The central portion of the cytoplasm was occupied by single or multiple cytoplasmic vacuoles. In all cases, the signet-ring cells were reactive for vimentin and negative for epithelial membrane antigen and cytokeratin. Four cases were focally positive for muscle-specific actin or smooth muscle actin and negative for CD68, Mac387, periodic acid-Schiff, mucicarmine, and alcian blue. In these 4 cases, the surrounding endometrial stroma showed decidual changes, and the signet-ring cells demonstrated a morphologic continuum with more typical decidualized stroma. As such, the signet-ring cells in these cases were vacuolated, decidualized endometrial stromal cells. In the remaining case, the vacuolar contents of the signet-ring cells were periodic acid-Schiff-positive and resistant to diastase predigestion, and the cells reacted with Mac387 and CD68. The surrounding stroma showed no decidual reaction. Thus, the signet-ring cells in this case were of histiocytic differentiation. Endometrial stroma occasionally may contain nonneoplastic signet-ring cells that closely mimic adenocarcinoma. At least 2 directions of differentiation, decidual and histiocytic, are possible.

Mammary lipogenic enzyme activity, trans fatty acids and conjugated linoleic acids are altered in lactating dairy cows fed a milk fat-depressing diet

The objectives of the present study were to examine the effect of a milk fat-depressing (MFD) diet on: 1) the activity of mammary acetyl-CoA carboxylase (ACC) and fatty acid synthase (FAS), 2) ACC mRNA relative abundance and 3) distributions of conjugated linoleic acids (CLA) and trans-18:1 fatty acids (tFA) in milk fat. Twelve lactating Holstein cows were used in a single reversal design. Two diets were fed: a control diet (60:40% forage/concentrate) and an MFD diet (25:70% forage/concentrate, supplemented with 5% soybean oil). The MFD diet decreased (P: < 0 0.001) milk fat by 43% and ACC and FAS activity by 61 and 44%, respectively. A reduced ACC mRNA relative abundance (P: < 0.001) corresponded with the lower ACC activity. The fatty acids synthesized de novo were decreased (P: < 0. 002), whereas tFA were increased from 1.9 to 15.6% due predominantly to a change in trans-10-18:1 isomer (P: < 0.001). With the MFD diet, the trans-7, cis-9 and trans-10, cis-12 CLA isomers were elevated (P: < 0.001), in contrast to the decrease in trans-11-18:1 (P: < 0. 001) and cis-9, trans-11-18:2. The data were consistent with a dietary effect on mammary de novo FA synthesis mediated through a reduction in ACC and FAS activity and in ACC mRNA abundance. The results were compatible with a role of trans-10, cis-12 CLA in milk fat depression, but alterations noted in tFA and other CLA isomers suggest that they also may be important during diet-induced milk fat depression.

The dental unit waterline controversy: defusing the myths, defining the solutions

BACKGROUND AND OVERVIEW

This article reviews the literature on the subject of dental unit waterline contamination. It has been expanded from the text of a lecture given at the Scientific Frontiers in Dentistry program sponsored by the National Institute for Dental and Craniofacial Research in Bethesda, Md., in July 1999. The author examines the underlying biological causes of waterline colonization by microorganisms, the evidence of potential health consequences and possible means of improving the quality of dental water. He also describes examples of devices currently marketed to improve and maintain the quality of dental treatment water.

CONCLUSIONS

Microorganisms colonize dental units and contaminate dental treatment water. While documented instances of related illness are few, water that does not meet potable-water standards is inappropriate for use in dentistry.

CLINICAL IMPLICATIONS

Exposure to water containing high numbers of bacteria violates basic principles of clinical infection control. Dentists should consider available options for improving the quality of water used in dental treatment.

Pathology residents' use of a Web-based tutorial to improve Gleason grading of prostate carcinoma on needle biopsies

Little is known about pathology residents' ability to Gleason grade or their ability to learn surgical pathology using Internet-based technology. A free Web-based program (available at www.pathology. jhu.edu/prostate) was developed that consisted of 20 pretutorial images for grading, 24 tutorial images, and the same 20 posttutorial images for Gleason grading. The grading images were selected from cases that had a consensus Gleason grade from 10 uropathology experts. In 2.5 months, 255 residents visited the website, and 151 (59%) completed it. Of those who completed the website, their year in training was known in 85 (56%): 1st year, 25.8%; 2nd year, 20%; 3rd year, 22.3%; 4th year, 14.1%; 5th year, 15.3%; and 6th year, 2.4%. Eighty percent learned Gleason grading in residency versus being self-taught, and 66% were male. In a multivariate analysis, higher pretutorial scores were associated with both their year in training (P = .001) and their hospital size (P = .003). Improvements in grading posttutorial were not related to the residents' year in training. Overall, the website significantly improved grading in 11 of 20 images and had no effect in 9 of 20 images. Improvements were noted in 1 of 1 Gleason score 4; 2 of 7 Gleason score 5 to 6; 2 of 6 Gleason score 7; and 6 of 6 Gleason score above 7 tumors. In summary, a Web-based tutorial improved Gleason grading accuracy by pathology residents to an equal extent regardless of their year in training. It is more difficult to teach residents to grade Gleason scores 5 to 7 tumors, and additional training should be concentrated in this area.

Expression of the porcine beta2-adrenergic receptor in Chinese hamster ovary cells

The gene for the porcine beta2-adrenergic receptor (pbeta2AR) was transfected into Chinese hamster ovary (CHO) cells for expression. Fourteen stable cell lines were obtained and exhibited receptor densities ranging from 12 to 2,371 fmol/mg membrane protein. The receptor density was not correlated with estimates of gene copy number obtained by Southern hybridization. The pbeta2AR in CHO cells exhibited saturable binding of [125I]CYP (Kd = 14.5 pM) and stereospecificity for (-)- and (+)-isoproterenol. The relative affinities for (-)-isoproterenol (ISO), (-)-epinephrine (EPI), and (-)-norepinephrine (NEPI) were ISO > EPI > NEPI, which are characteristic of beta2AR. The affinity values for these ligands were similar to those in other species. Binding of ISO, EPI, and NE revealed two affinity states of the betaAR; the high-affinity state was eliminated by adding Gpp(NH)p, a nonhydrolyzable GTP analogue. Binding of the antagonist propranolol modeled to only one affinity state, and Gpp(NH)p did not affect binding. Multiple affinity states are characteristic of agonist-induced coupling of betaAR with G-proteins, and the data suggest that the cloned pbetaAR is functionally competent. Data confirm that the pbeta2AR is the pig version of beta2AR. Stable CHO cell lines will be useful for characterization of pbeta2AR and screening and designing potential drugs that may be used to enhance pig production.

Delayed death owing to blunt cardiac injury

Two cases of blunt myocardial injury to the region of the anterior descending branch of the left coronary artery causing death are described. In one case, direct injury appeared to have resulted in myocardial infarction, whereas in the other, cardiac arrhythmia (possibly secondary to coronary artery spasm) was implicated. Although apparently uncommon, deaths following blunt injury to the coronary arteries may cause death, but are difficult to predict and prevent.

Further analysis of maize C(4) pyruvate,orthophosphate dikinase phosphorylation by its bifunctional regulatory protein using selective substitutions of the regulatory Thr-456 and catalytic His-458 residues

In C(4) plants such as maize, pyruvate,orthophosphate dikinase (PPDK) catalyzes the regeneration of the initial carboxylation substrate during C(4) photosynthesis. The primary catalytic residue, His-458 (maize C(4) PPDK), is involved in the ultimate transfer of the beta-phosphate from ATP to pyruvate. C(4) PPDK activity undergoes light-dark regulation in vivo by reversible phosphorylation of a nearby active-site residue (Thr-456) by a single bifunctional regulatory protein (RP). Using site-directed mutagenesis of maize recombinant C(4) dikinase, we made substitutions at the catalytic His residue (H458N) and at this regulatory target Thr (T456E, T456Y, T456F). Each of these affinity-purified mutant enzymes was assayed for changes in dikinase activity. As expected, substituting His-458 with Asn results in a catalytically incompetent enzyme. Substitutions of the Thr-456 residue with Tyr and Phe reduced activity by about 94 and 99%, respectively. Insertion of Glu at this position completely abolished activity, presumably by the introduction of negative charge proximal to the catalytic His. Furthermore, neither the T456Y nor inactive H458N mutant enzyme was phosphorylated in vitro by RP. The inability of the former to serve as a phosphorylation substrate indicates that RP is functionally a member of the Ser/Thr family of protein kinases rather than a "dual-specificity" Ser-Thr/Tyr kinase, since our previous work showed that RP effectively phosphorylated Ser inserted at position 456. The inability of RP to phosphorylate its native target Thr residue when Asn is substituted for His-458 documents that RP requires the His-P catalytic intermediate form of PPDK as its protein substrate. For these latter studies, synthetic phosphopeptide-directed antibodies specific for the Thr(456)-P form of maize C(4) PPDK were developed and characterized.

Dental unit waterline antimicrobial agents' effect on dentin bond strength

BACKGROUND

In response to concerns of bacterial biofilm colonization of dental unit waterlines, a wide range of commercial intermittent and continuous chemical treatments for dental unit waterlines have been developed and marketed. There has been little research on the possible effect of continuous chemical treatment regimens on dentin-bonding agents. The authors evaluate the effect of four proposed antimicrobial agents used in dental unit waterlines on dentin bond strength.

METHODS

The authors used a fifth-generation dentin-bonding agent to bond composite cylinders to molar dentin surfaces. They then used selected antimicrobial agents as rinsing agents after conditioning. The composite cylinders were shear tested, and their fracture strengths were compared statistically.

RESULTS

All proposed antimicrobial agents reduced dentin bond strength. Proposed waterline treatment regimens of a diluted mouthrinse and chlorhexidine significantly reduced dentin bond strength compared with sodium hypochlorite and citric acid regimens.

CONCLUSION

Dental professionals should be aware of potential interactions between dental unit waterline antimicrobial agents and dentin-bonding agents. Further research in this area is warranted, as the clinical implications are uncertain at this time.

CLINICAL IMPLICATIONS

Dental unit waterline antimicrobial agents may adversely affect dentin bonding strength.

Regulation of porcine adipocyte metabolism by insulin and adenosine

The acute effects of insulin and adenosine on rates of lipolysis and lipogenesis in pig adipocytes were investigated to determine what limits the expression of the insulin response in vitro. Adenosine and insulin independently inhibited isoproterenol-stimulated lipolysis. Adenosine, acting through the pertussis toxin-sensitive G-protein Gi, was more effective than insulin and could completely inhibit lipolysis. Fatty acid synthesis from glucose was increased by both adenosine and insulin. Neutralization of endogenous adenosine with adenosine deaminase decreased basal rates of lipogenesis and increased the insulin response from 30 to 60% above basal. Neutralization of Gi with pertussis toxin further decreased the basal rate and increased the insulin response to 160% above basal. These data indicate that Gi, and the ligands that signal through Gi, stimulate glucose incorporation into fatty acids and can attenuate the insulin response. It seems likely that an exaggerated rate of glucose metabolism in the absence of insulin contributes to the inconsistent insulin responses exhibited in pig adipose tissue in vitro. These data also demonstrate that insulin and adenosine have major roles in regulating pig adipose tissue metabolism.

Combining periodic and continuous sodium hypochlorite treatment to control biofilms in dental unit water systems

BACKGROUND

This study evaluated the efficacy of combined intermittent and continuous treatment with diluted sodium hypochlorite, or NaClO, to improve dental unit water quality in a clinical setting.

METHODS

In this prospective study, 10 dental units were fitted with separate water reservoir systems. Dental units were maintained with weekly rinses with 1:10 NaClO. Treatment water consisted of 750 milliliters of tap water and one drop of undiluted commercial bleach. Bacterial contamination in the effluent coolant water was assayed via microbiologic culture on a weekly basis. At the end of the study, scanning electron microscopy of the inner surfaces of the dental unit waterlines corroborated the results.

RESULTS

All 10 dental units consistently delivered water with less than 10 colony-forming units per milliliter, or CFU/mL, with a mean bacterial contamination of less than 1 CFU/mL. Baseline scanning electron microscopy demonstrated biofilm formation. Scanning electron microscopy at the end of the study demonstrated the lack of features consistent with biofilm formation. Although tri-halomethanes were detected in output water, all samples were below Environmental Protection Agency limits for drinking water.

CONCLUSIONS

Weekly treatment with 5.25 percent NaClO diluted 1:10, and concomitant use of chlorinated treatment water (3 parts per million chlorine) consistently attained the proposed American Dental Association goal of fewer than 200 CFU/mL in the unfiltered output. The effects of continuous treatment on dentin and enamel bond strength may require further evaluation.

CLINICAL IMPLICATIONS

The success of this protocol suggests that optimal attainment of dental water quality goals may require a combination of approaches.

Postoperative/posttraumatic spindle cell nodule of the skin: the dermal analogue of nodular fasciitis

Spindle cell proliferations of the skin are diverse, both morphologically and mechanistically. The authors have encountered four examples of a distinctive reactive/reparative cutaneous spindle cell lesion that shows homology with ones seen in the genitourinary tract and oral cavity and that is known as "postoperative/posttraumatic spindle cell nodule" (PSCN). These occurred in the skin of the face and scalp (2 cases), arm (1 case), and vulvar skin (one case), and were clearly related historically to prior episodes of trauma. The proliferations were characterized by variably-apposed and cytologically-bland spindle cells with numerous mitotic figures, set in a highly vascular stroma containing extravasated erythrocytes and inflammatory cells. All lesions were immunoreactive for vimentin, actin, and desmin, with no labeling for keratin. Postoperative/posttraumatic spindle cell nodule of the skin is a significant pseudoneoplastic lesion that is related (and perhaps identical pathogenetically) to nodular fasciitis; as such, it may be mistaken for a sarcoma or a spindle cell carcinoma. Careful attention to clinicopathologic and histologic details should result in its accurate recognition.

Histologic transformation of polymorphous low-grade adenocarcinoma of salivary gland

Polymorphous low-grade adenocarcinoma of salivary gland origin (PLGA) was initially described in 1984 and has since become an established clinicopathologic entity. Owing to the indolent nature of PLGA and its relatively recent description, the full clinicopathologic spectrum of this entity has not been elucidated fully. Transformation to a histologically different-appearing lesion or progression to a higher histologic grade has not been reported. We describe 2 PLGAs arising in the palate and associated with multiple locoregional recurrences that were treated with excision and radiation therapy. This was followed by histologic transformation to a higher grade neoplasm after 17 and 26 years, respectively. The histologic appearance after transformation was characterized by a predominantly solid and cystic growth pattern, nuclear atypia with prominent nucleoli, and foci of necrosis. High-grade transformation of PLGA may occur after a protracted clinical course with multiple recurrences of typical PLGA. The possible role of radiation therapy as an initiator of this transformation merits further study. Tumors with these histologic features should not be included under the rubric of typical PLGA. Segregation of these neoplasms will allow further study of their biologic potential, particularly with regard to possible increased rates of local recurrence and metastasis.

Inhibin is not an immunohistochemical marker for hepatocellular carcinoma. An example of the potential pitfall in diagnostic immunohistochemistry caused by endogenous biotin

Inhibin is a heterodimeric glycoprotein originally detected in gonadal tissues. One report described inhibin immunopositivity in 17 of 19 hepatocellular carcinomas (HCCs) and the hepatocytes of the surrounding nonneoplastic parenchyma. The reported immunohistochemical method, which used avidin-biotin complex, did not describe blocking endogenous biotin. Since liver tissue may contain high levels of biotin, endogenous biotin may result in false-positive immunostaining. We wondered whether this reported immunopositivity represented a false-positive result due to unblocked endogenous biotin. By using a similar antigen retrieval technique and the same specificity, titer, and clonal source of primary antibody as the aforementioned study, we performed immunostaining for inhibin with and without an endogenous biotin blocking step on 23 cases of HCC and the surrounding cirrhotic liver. In all cases, the HCC and the hepatocytes in the cirrhotic nodules were negative for inhibin when the endogenous biotin blocking step was used. When the blocking step was omitted, apparent immunostaining was noted in 20 of 23 HCCs and in the hepatocytes in all cases. Accordingly, HCC and the hepatocytes of the surrounding cirrhotic liver are immunohistochemically negative for inhibin. The previously reported immunopositivity of HCC and nontumoral hepatocytes for inhibin represents a false-positive result due to endogenous biotin.

Incidence of loss of heterozygosity at p53 and BRCA1 loci in serous surface carcinoma

Serous surface carcinoma (SSC) is a neoplasm histologically indistinguishable from typical serous carcinomas that arise from the ovary but has a distinct clinical presentation. It is characterized by widespread peritoneal dissemination at presentation, but the ovaries are grossly normal in size and shape. If the carcinoma involves the ovaries microscopically, the tumor is confined to the surface or is minimally invasive. The recognition of this entity is important, because in some studies it appears to have a poorer prognosis than stage-matched serous cancers of the ovary. Loss of heterozygosity (LOH) of the p53 (17p) and BRCA1 (17q) tumor suppressor genes has been frequently identified in sporadic ovarian carcinomas. Although 17p LOH is correlated with common p53 gene mutations, inactivating mutations of the BRCA1 gene are uncommon in sporadic ovarian cases. In contrast, germline BRCA1 mutations are responsible for some hereditary forms of ovarian cancer, where it has been suggested that germline BRCA1 mutations confer a more favorable prognosis. In this study, 12 sporadic SSC were assessed for the presence of allelic deletions on the p53 and BRCA1 gene loci. DNA from both tumor and normal cells was obtained for LOH studies using tissue microdissection. Polymerase chain reaction (PCR) amplification was performed with the polymorphic DNA markers TP53 (17p13.1/p53 gene) and D17S579 (17q/BRCA1 gene). LOH in the p53 and BRCA1 loci was detected in 62.5% and 66.6% of the cases, respectively. In 50% of tumors informative for both markers, it is possible that an entire chromosome may be lost. In conclusion, we have shown that LOH of the p53 and BRCA1 loci is a frequent event in sporadic SSC, similar to what has been described in the usual form of serous ovarian carcinoma. Mutational analysis will be necessary to determine the exact role of these genes in this group of tumors.

Determination of optimal freezing parameters of human prostate cancer in a nude mouse model

BACKGROUND

We sought to determine whether more than one freeze/thaw cycle is required and what minimum temperature reliably kills prostate cancer in vivo.

METHODS

Two human prostate cancer cell lines (LNCaP and PC3) were implanted subcutaneously in male nude BALB/c mice. Tumors were frozen with contemporary cryosurgery equipment and monitored for temperature, size, and serum prostate-specific antigen (PSA) measurements. The tumors were subjected to one or two freeze/thaw cycles through a wide range of temperatures from 0 - -80 degrees C.

RESULTS

These experiments show that a single freeze/thaw to a temperature < -40 degrees C is adequate to kill most tumor cells in this mouse model of prostate cancer.

CONCLUSIONS

Freezing prostate cancer to < -40 degrees C and ensuring that the entire tumor is frozen is more important than additional freeze/thaw cycles in this experimental model.

Comparison of methods to enumerate bacteria in dental unit water lines

Millipore HPC samplers are simple, self-contained test devices that can be used by personnel in dental offices who do not have microbiologic training to easily and economically monitor dental unit water quality without laboratory support. This study evaluated the correlation of HPC samplers to R2A agar for enumerating planktonic bacteria in dental unit treatment water. Eight different dental units were sampled. Five replicates were performed for each media at each dilution. The Pearson correlation coefficient between the R2A agar and HPC sampler is 0.89. These data suggest HPC samplers correlate with conventional laboratory-based R2A culture techniques for determining dental unit water line contamination.

Detection of the alpha-subunit of inhibin in trophoblastic neoplasia

Placental trophoblasts are the primary source of serum inhibin during pregnancy. We sought to characterize inhibin immunolabeling in trophoblastic neoplasms and compare the results with those for established markers of trophoblastic differentiation. Formalin-fixed, paraffin-embedded tissues from three normal term placentas, 13 hydatidiform moles (HM), five choriocarcinomas (CC) (three gestational, one testicular, one mediastinal), and five placental site trophoblastic tumors (PSTT) were immunolabeled with antibodies to the alpha-subunit of inhibin, hPL, and beta-hCG. Additionally, six first-trimester placentas were immunolabeled with antibody to inhibin alone. Trophoblastic subpopulations were assessed for the number of positive cells (1% to 24% = 1+,25% to 49% = 2+,50% to 74% = 3+, 75% to 100% = 4+). Immunolabeling in term placenta and HM was similar, because beta-hCG was the most sensitive marker (4+) of syncytiotrophoblasts followed by inhibin (3-4+) and hPL (2-3+). Immunolabeling of syncytiotrophoblasts in CC was similar to that in term placenta and HM, except for negative hPL staining in two cases. In HM, inhibin labeling of intermediate trophoblasts (2-3+) was less than that for hPL (3-4+). In CC, inhibin and hPL labeling of intermediate trophoblasts was more variable with negative hPL reactivity in two cases. Inhibin and hPL did not stain cytotrophoblasts. In PSTT, inhibin immunolabeling was a better marker than hPL in two cases, inferior in two, and similar in one. Inhibin labeling of syncytiotrophoblasts was less than that for beta-hCG, but did not have the often marked background staining that was present with beta-hCG. Immunolabeling of trophoblast subpopulations for inhibin was similar between first-trimester placenta, term placenta, and HM. We conclude that inhibin is a useful immunohistochemical marker of trophoblastic neoplasia and should be included in the antibody panel with beta-hCG and hPL.

Expression of androgen receptors in nasopharyngeal angiofibroma: an immunohistochemical study of 24 cases

Angiofibromas are uncommon benign tumors that typically occur in the lateral portion of the nasopharynx of adolescent boys. Numerous reports showed indirect evidence for the presence of sex-hormone receptors, i.e., androgen (AR), estrogen (ER), and progesterone (PR) receptors, in these tumors. The goal of the current study was to show direct evidence of sex hormone receptor expression in angiofibromas with use of sensitive immunocytochemical techniques and to document which cell populations express the receptor. Twenty-four nasopharyngeal angiofibromas were obtained from archived tissue, and immunocytochemical studies were performed with antibodies to AR, PR, and ER. Positive stromal and endothelial nuclear immunostaining, implying the presence of ARs, was seen in 18 (75%) of 24 cases, whereas 2 (8.3%) of 24 cases were positive with antibodies to PR. None of the 24 cases examined was positive with antibodies to ER. These results provide the first direct evidence for the presence of ARs in angiofibromas, which might help to explain the unique clinicopathologic features of these tumors.

Independent effects of food intake and insulin status on insulin-like growth factor-I in young pigs

The independent effects of decreased food intake and diabetic hyperglycemia on serum GH, serum IGF-I and tissue IGF-I expression were examined in young streptozotocin-diabetic pigs. Each of three treatments (control, diabetic, and insulin-treated diabetic) were represented within three levels of regulated food intake (FI) provided as three meals per day equivalent to 100, 50, and 10% of the voluntary FI consumed by the untreated diabetics. Reduction of food intake was associated with decreased body weight gains, decreased serum IGF-I concentrations, and increased serum GH concentrations. Nutrient restriction also tended to decrease the relative abundance of IGF-I mRNA in liver and skeletal muscle. Diabetic pigs with hyperglycemia and hypoinsulinemia had higher serum concentrations of IGF-I than pair-fed controls, but exogenous insulin treatment of these diabetic pigs increased serum IGF-I even further and also tended to increase the relative abundance of IGF-I mRNA in liver and skeletal muscle. When the statistical effects of reduced FI were eliminated, neither the present form of diabetes nor exogenous insulin affected serum GH. In summary, diabetes-induced changes in IGF-I in these pigs depended primarily on the reduced level of food intake occurring in these hypoinsulinemic, hyperglycemic subjects.

Pulmonary clear cell carcinoid tumor: another entity in the differential diagnosis of pulmonary clear cell neoplasia

A clear cell variant of primary pulmonary carcinoid tumor is described. The tumor arose in a 53-year-old woman who was incidentally found to have a solitary pulmonary nodule in the left upper lobe during routine chest roentgenography. Histologically, the tumor was composed of predominantly clear to lightly eosinophilic, polygonal cells with bland nuclei arranged in sheets and nests. Nuclear pleomorphism, necrosis, vascular invasion, and mitotic figures were not seen. The tumor cells were negative for oil-red-O and periodic acid-Schiff stains with and without diastase pretreatment on frozen and formalin-fixed sections, respectively. During immunohistochemical evaluation, the tumor cells were focally positive for cytokeratin and diffusely positive for neuron-specific enolase and chromogranin. Electron microscopy performed on paraffin block-retrieved tissue showed the presence of electron-dense, neurosecretory-type granules and variably sized vacuolated areas within the cytoplasm. the nature of which remained unclear. Intracytoplasmic glycogen or lipid were not identified. To our knowledge, this is the first report of pulmonary clear cell carcinoid tumor.

The alpha subunit of inhibin in adrenal cortical neoplasia

We analyzed 23 adrenal adenomas and 15 adrenal cortical carcinomas by immunolabeling for the alpha subunit of inhibin, and we then compared the results with the functional status of the neoplasms. We also studied 19 pheochromocytomas, 30 renal cell carcinomas, and 5 extra-adrenal paragangliomas, tumors posing differential diagnostic problems with adrenal cortical neoplasms. Immunolabeling was performed using automated immunohistochemical methods and an antibody directed against the alpha subunit. Tumors were semiquantitatively assessed for the number of positive cells. Immunopositivity was obtained in 18 (78%) of 23 adrenal cortical adenomas, 12 (80%) of 15 adrenal cortical carcinomas, 2 (11%) of 19 pheochromocytomas, 0 of 5 extra-adrenal paragangliomas, and 0 of 30 renal cell carcinomas. Immunoreactivity was strong in 7 (78%) of 9 adrenal cortical tumors from patients with Cushing's-related or virilizing symptoms. In contrast, only 4 (14%) of 29 tumors that were clinically nonfunctioning or associated with hyperaldosteronism demonstrated strong staining (P < .001). In clinically nonfunctioning tumors, there was a tendency for increased immunopositivity in tumors from patients with elevated levels of cortisol, androgen, or their precursors, with four of six tumors having at least moderate immunopositivity. Similar reactivity was present in only one of eight tumors from patients with normal laboratory values (P=.091). Moderate or strong immunopositivity was present in 9 (60%) of 15 adrenal cortical carcinomas, whereas of the pheochromocytomas, extra-adrenal paragangliomas, and renal cell carcinomas, only 1 (1.9%) of 54 showed moderate-to-strong reactivity. We conclude that moderate or strong immunoreactivity for the alpha subunit of inhibin occurs in adrenal cortical tumors from patients with Cushing's-related or virilizing symptoms. Immunolabeling for the inhibin alpha subunit is potentially useful in the differential diagnosis of neoplasms that include adrenal cortical carcinomas.

The diagnostic utility of inhibin staining in ovarian neoplasms

Previous immunohistologic studies have suggested that the antibody to the alpha subunit of inhibin is a sensitive marker of sex cord-stromal differentiation. However, detection has also been reported within both ovarian epithelial and germ cell tumors. To further study the normal tissue distribution of inhibin and the utility of its detection for the differential diagnosis of ovarian sex cord-stromal neoplasms, normal tissues and 225 lesions including sex cord-stromal lesions, ovarian epithelial and stromal cancers, ovarian and testicular germ cell tumors, metastases to the ovary, and non-ovarian cancers were analyzed using semi-automated immunohistochemistry. In normal tissues, immunostaining was found in cell subsets of the ovary, testis, adrenal gland, placenta, and kidney. All sex cord-stromal tumors were inhibin-positive and 37 of 50 (74%) cases exhibited at least moderate to strong immunostaining. Two cases originally diagnosed as adult granulosa cell tumors that were inhibin-negative were reassessed; diagnoses of endometrioid stromal sarcoma and endometrioid carcinoma with sertoliform features were rendered. In other primary or metastatic ovarian lesions or metastases to the ovary, weak to moderate immunostaining was found in only 4 of 84 (4.8%) cases, including ovarian clear cell carcinoma (2/2), uterine clear cell carcinomas metastatic to the ovary (1/3), and serous papillary carcinoma (1/2). Similarly, only 4 of 66 (6.1%) non-ovarian neoplasms exhibited weak immunostaining, including melanoma (1/5), uterine endometrioid carcinoma (1/2), transitional cell carcinoma (1/3), and breast adenocarcinoma (1/8). Only one case of a non-sex cord-stromal tumor had moderate or strong immunostaining. Based on these results, immunohistologic detection of the alpha subunit of inhibin is a useful adjunct in the differential diagnosis of sex cord-stromal neoplasms.

Validation of an in-office dental unit water monitoring technique

The authors conducted a study to determine the sensitivity, specificity and accuracy of HPC Samplers (Millipore Corp.) as compared with that of R2A agar and HPC agar when used to monitor dental unit water, or DUW, quality. Results were either a pass (200 colony-forming units per milliliter, or CFU/mL, or less) or a fail (greater than 200 CFU/mL). Of the 408 tests conducted, the results of the HPC Sampler agreed with R2A agar 377 times, for an accuracy rate of 92.6 percent. The authors recommend that clinicians consider using HPC Samplers, as they are a user-friendly, economical means of monitoring compliance of DUW quality.

Serous and mesothelial proliferations of the extraovarian peritoneum and pelvic lymph nodes

With rare exceptions, serous proliferations of the peritoneum are limited to women, whereas proliferations of mesothelial differentiation arise predominantly in men. The authors focus on the various types of serous and mesothelial proliferations of the peritoneum and pelvic lymph nodes. Discussion of each type focuses on clinical and morphologic features, histogenesis, differential diagnosis, and clinical outcome.

Homologous carcinomas of the breasts, skin, and salivary glands. A histologic and immunohistochemical comparison of ductal mammary carcinoma, ductal sweat gland carcinoma, and salivary duct carcinoma

Morphologic mimicry among human malignant neoplasms is a well-known phenomenon in surgical pathology; both undifferentiated and "committed" neoplasms may exhibit this trait. One particularly common group of histologic simulants includes ductal carcinomas of the breasts, the cutaneous appendages, and the salivary glands. One hundred three tumors in this structural cluster were analyzed microscopically and immunohistologically to codify points of potential pathologic similarity and difference. All the lesions were typified by irregularly permeative clusters and cords of atypical polygonal cells with variable luminal differentiation. A proportion of primary neoplasms in each site demonstrated in situ ductal components; in the absence of the latter elements, however, it was not possible to make topography-related morphologic distinctions among them. Immunostains for gross cystic disease fluid protein-15 (GCDFP-15), carcinoembryonic antigen, S100 protein, c-erbB-2 oncoprotein, estrogen receptor protein, and progesterone receptor protein also showed largely overlapping phenotypes in each of the three tumor categories, with selected exceptions. These differences were elucidated through paired chi 2 analysis and included a statistically significant infrequency of GCDFP-15 in eccrine sweat gland carcinomas, a paucity of carcinoembryonic antigen in breast cancers, and an absence of estrogen receptor protein in salivary duct carcinomas. Such findings may be useful in predefined differential diagnostic settings involving the distinction between primary and metastatic ductal cancers of the breasts, skin, and salivary glands. Nevertheless, because of the striking homologies between such tumors at structural and protein-synthetic levels of comparison, it is mandatory that all available clinicopathologic information be used in this context.

Cathepsin D and chromogranin A as predictors of long term disease specific survival after radical prostatectomy for localized carcinoma of the prostate

BACKGROUND

The accumulation of chromogranin A (Chr A) and cathepsin D (Cath D) gene products may be important in prostate carcinoma progression. This study assessed whether the levels of immunoreactivity for Chr A and Cath D are better predictors of disease specific survival than conventional pathologic parameters of the primary tumor such as Gleason score, capsular penetration, seminal vesicle invasion, and percent tumor in the specimen for patients with clinically localized prostate carcinoma managed by radical prostatectomy.

METHODS

Seventy-one patients with modified Jewett clinical stages A1 to B2 adenocarcinoma of the prostate underwent a radical prostatectomy after a negative metastatic workup. No neoadjuvant or adjuvant treatments were given and all disease recurrences and causes of death were recorded. Analysis of prostatectomy specimens was undertaken to determine the conventional pathologic parameters of the primary tumor and Chr A and Cath D immunohistochemical staining. Univariate and multivariate analyses were performed to determine the independent contributions of Chr A and Cath D in predicting survival.

RESULTS

On univariate analysis Chr A was the only variable that reached statistical significance for disease specific survival (P = 0.035). Cath D nearly reached significance with a P value of 0.079 for disease specific survival. On multivariate analysis, the only independent factor predicting disease specific survival was the Chr A staining score (P < 0.05). In patients with unequivocal foci of Chr A immunoreactivity, the 14-year disease specific survival was 50% compared with 68% for patients lacking such foci.

CONCLUSIONS

The level of Chr A immunohistochemical staining is a strong predictor of disease specific survival and is superior to standard pathologic prognostic factors. Such findings lay the groundwork for future prospective study of the utility of such markers on biopsy specimens to predict patient outcome.

Clear cell tumors of the lower respiratory tract

Clear cell tumors of the lower respiratory tract comprise a diverse group of lesions. The prototypical lesion is the benign clear cell tumor or "sugar tumor," a tumor of enigmatic histogenesis, whose name derives from the high glycogen content of the cells. Analogous to the salivary gland lesion of the same name, acinic cell tumors may also occur in the tracheobroncheal tree. The topic of "clear cell carcinoma" is discussed, which in the opinion of the authors does not constitute a distinct tumor entity. A discussion of potential lesion metastatic to the lung with clear cell histology is also presented. Histological details of the various entities are discussed, as well as the significant histochemical, immunohistological, and electron microscopic features; in particular, such findings that are relevant to differential diagnosis are stressed, including the distinction of primary and metastatic lesions.

Clear cell tumors of the alimentary tract and abdominal cavity

Clear cell neoplasms of the abdominal organs are represented by a variety of epithelial and mesenchymal neoplasms, of varying malignant potential. Several varieties of clear cell carcinomas, including those with tubulopapillary, hepatoid, colloid, or neuroendocrine features, have been described, as well as several benign epithelial neoplasms. These epithelial tumors have been reported in the gastrointestinal hollow viscera, as well as the liver, pancreas, and biliary tract. A second major consideration is the mesenchymal-derived gastrointestinal stromal tumors, which also may feature clear cells, and comprise a spectrum of biological behavior. Miscellaneous lesions include clear cell variants of melanoma and mesothelioma. This review includes histological details of the various entities, as well as important histochemical, immunohistological, and ultrastructural features. Pertinent differential diagnostic points are stressed, including distinction of the primary clear lesions from relevant metastatic neoplasms.

Clear cell tumors of unknown nature and origin: a systematic approach to diagnosis

Not infrequently, surgical pathologists encounter malignant neoplasms composed of clear cells, the sources and natures of which are indeterminate on the basis of conventional morphological study. In this context, it is frustrating that tumors of completely dissimilar lineage can show strikingly similar microscopic appearances; moreover, anatomic location provides few if any definitive clues to the likely final diagnosis in many cases of clear cell neoplasia. Because of these factors, it is necessary to systematically pursue the same approach to the pathological assessment of clear cell tumors, routinely considering not only clinical and radiologic details but also the possible application of immunohistology, electron microscopy, and cytogenetics. This review provides algorithmic schemes by which such techniques can be applied, as well as their potential drawbacks and limitations.

p53, bcl-2 and retinoblastoma proteins as long-term prognostic markers in localized carcinoma of the prostate

PURPOSE

The accumulation of p53 and bcl-2 gene products as well as the loss of the retinoblastoma (Rb) gene product have been associated with prostate cancer progression. We assessed whether the levels of immunoreactivity for p53, Rb and bcl-2 are better long-term predictors of disease specific survival than conventional pathological parameters of the primary tumor, such as Gleason score, capsular penetration, seminal vesicle invasion and percent tumor in the specimen, in patients with clinically localized prostate cancer treated with radical prostatectomy.

MATERIALS AND METHODS

A total of 71 patients with clinical stages A1 to B2 adenocarcinoma of the prostate underwent radical prostatectomy after a negative metastatic evaluation. No neoadjuvant or adjuvant treatments were given and causes of death were recorded. Prostatectomy specimens were analyzed to determine the conventional pathological parameters, and p53, Rb and bcl-2 immunohistochemical staining. Univariate and multivariate analyses were done to determine the independent contributions of p53, Rb and bcl-2 in predicting survival.

RESULTS

On multivariate analysis the independent factors predicting disease specific survival were p53 staining score (p < 0.001) and Rb staining score (p < 0.001). In patients with p53 immunoreactive tumors the 15-year disease specific survival was 38% compared to 87% for those with less immunoreactivity. Analysis of Rb immunoreactivity for 15-year disease specific survival yielded 92 and 66% high and low staining levels, respectively. Best subset analysis revealed that the combination of p53 score and Rb score yielded the best predictive value for disease specific survival.

CONCLUSIONS

p53 and Rb immunohistochemical staining scores were independent predictors of disease specific survival and were superior to conventional pathological prognostic factors of the primary tumor. These findings lay the groundwork for the prospective study of these markers in patients treated with radical prostatectomy.