Isam Eltoum

SIRT1 Is Significantly Elevated in Mouse and Human Prostate Cancer

Evidence suggests that the histone deacetylase, SIRT1, is a mediator of life span extension by calorie restriction; however, SIRT1 may paradoxically increase the risk of cancer. To better understand the relationship among SIRT1, energy balance, and cancer, two experiments were done. First, a transgenic mouse model of prostate cancer (transgenic adenocarcinoma of mouse prostate; TRAMP) was used to determine the role of energy balance on SIRT1 expression and the effect of cancer stage on SIRT1 and hypermethylated in cancer-1 (HIC-1). Second, immunohistochemistry was done on human prostate tumors to determine if SIRT1 was differentially expressed in tumor cells versus uninvolved cells. Results show that SIRT1 is not increased in the dorsolateral prostate (DLP) of calorie-restricted mice during carcinogenesis. In contrast, when examined in the DLP as a function of pathologic score, SIRT1 was significantly elevated in mice with poorly differentiated adenocarcinomas compared with those with less-advanced disease. HIC-1, which has been shown to regulate SIRT1 levels, was markedly reduced in the same tumors, suggesting that a reduction in HIC-1 may be in part responsible for the increased expression of SIRT1 in prostatic adenocarcinomas. Furthermore, immunostaining of human prostate tumors showed that cancer cells had greater SIRT1 expression than uninvolved cells. In conclusion, DLP SIRT1 expression from calorie-restricted mice was not altered during carcinogenesis. However, SIRT1 expression was increased in mice with poorly differentiated adenocarcinomas and in human prostate cancer cells. Because SIRT1 may function as a tumor promoter, these results suggest that SIRT1 should be considered as a potential therapeutic target for prostate cancer.

Endoscopic ultrasound-guided fine needle aspiration biopsy of patients with suspected pancreatic cancer: diagnostic accuracy and acute and 30-day complications.

OBJECTIVES:The aims of this study were to evaluate the diagnostic accuracy of endoscopic ultrasound–guided fine needle aspiration (EUS-FNA) in patients with suspected pancreatic cancer, and to assess immediate, acute, and 30-day complications related to EUS-FNA.METHODS:All patients with suspected pancreatic cancer were prospectively evaluated. A single gastroenterologist performed all EUS-FNAs in the presence of a cytopathologist. Immediate complications were evaluated in all patients. An experienced nurse called patients 24–72 h and 30 days after the procedure. Reference standard for the classification of the final diagnosis included: surgery (n = 48), clinical or imaging follow-up (n = 63), or death from the disease (n = 47).RESULTS:A total of 158 patients (mean age 62.3 yr) underwent EUS-FNA during the study period. The mean tumor size was 32 × 26 mm. The median number of passes was three (range one to 10). Of these patients, 44% had at least one failed attempt at tissue diagnosis before EUS-FNA. The sensitivity, specificity, PPV, NPV, and accuracy of EUS-FNA in solid pancreatic masses were 84.3%, 97%, 99%, 64%, and 84%, respectively. Immediate self-limited complications occurred in 10 of the 158 EUS-FNAs (6.3%). Of 90 patients contacted at 24–72 h, 78 patients (87%) responded. Of the 90 patients, 20 (22%) reported at least one symptom, all of which were minor except in three cases (one self-limited acute pancreatitis and two emergency room visits, one of which led to admission). In all, 83 patients were contacted at 30 days, and 82% responded. No additional or continued complications were reported.CONCLUSIONS:EUS-FNA is highly accurate in identifying patients with suspected pancreatic cancer, especially when other modalities have failed. Major complications after EUS-FNA are rare, and minor complications are similar to those reported for upper endoscopy. It seems that follow-up at 1 wk might capture all of the adverse events related to EUS-FNA.

Endoscopic Ultrasound-Guided Fine-Needle Aspiration A Cytopathologist's Perspective

Endoscopic ultrasound (EUS) is used to detect and delineate the extent of lesions in the gastrointestinal tract, periluminal lymph nodes, pancreas and hepatobiliary tree, left kidney, spleen, and adrenal glands. EUS-guided fine-needle aspiration (FNA) has added a new dimension to the capabilities of EUS because it permits characterization of the lesion, thereby enabling triage of patients for more efficient and effective management. This review focuses on the advantages and limitations of EUS-FNA, including a discussion of potential pitfalls in the diagnosis of commonly aspirated deep-seated lesions, such as those of the pancreas and lymph nodes. It also addresses the practical considerations associated with establishing an effective service and the importance of an integrated approach in which the cytopathologist undertakes a key role, interacting extensively with the endoscopist and the patient management team. EUS-FNA is a sensitive modality that enables specific and accurate diagnosis of deep-seated lesions. Samples can be obtained effectively from small lesions (< 25 mm), irrespective of the organ site. On-site assessment permits a highly accurate preliminary diagnosis of malignancy for samples obtained by EUS-FNA and provides an opportunity to increase the diagnostic yield of samples.

Endoscopic Ultrasound–Guided Fine-Needle Aspiration

Endoscopic ultrasound (EUS) is used to detect and delineate the extent of lesions in the gastrointestinal tract, periluminal lymph nodes, pancreas and hepatobiliary tree, left kidney, spleen, and adrenal glands. EUS-guided fine-needle aspiration (FNA) has added a new dimension to the capabilities of EUS because it permits characterization of the lesion, thereby enabling triage of patients for more efficient and effective management. This review focuses on the advantages and limitations of EUS-FNA, including a discussion of potential pitfalls in the diagnosis of commonly aspirated deep-seated lesions, such as those of the pancreas and lymph nodes. It also addresses the practical considerations associated with establishing an effective service and the importance of an integrated approach in which the cytopathologist undertakes a key role, interacting extensively with the endoscopist and the patient management team. EUS-FNA is a sensitive modality that enables specific and accurate diagnosis of deep-seated lesions. Samples can be obtained effectively from small lesions (<25 mm), irrespective of the organ site. On-site assessment permits a highly accurate preliminary diagnosis of malignancy for samples obtained by EUS-FNA and provides an opportunity to increase the diagnostic yield of samples.

Introduction to the Theory and Practice of Fixation of Tissues

Abstract Many approaches to fixation and types of fixatives have been developed and tested over the last-century. The mechanisms by which fixatives act to harden and preserve tissues fall into broad categories, including dehydrants, heat effects, cross-linkers, effects of acids, and combinations of these categories. Each fixative has advantages and disadvantages, including specific molecules retained within “fixed” tissues, swelling or shrinkage of fixed tissues, variations in the qualitv of histochemical and immunohistochemical staining, and varying capabilities to maintain the structures of cellular organelles. One of the major problems with formaldehyde type (cross-linking) fixatives has been the loss of antigen immunorecognition; correcting this usually requires some method of antigen recovery. Similarly, the extraction of mRNA and DNA from formalin fixed tissue in paraffin blocks is problematic. All widely used fixatives are selected by compromise—good aspects are balanced against less desirable features. This article discusses the basics of fixation and provides the formulas for the fixatives currently used in pathology, histology, and anatomy and discusses good and bad aspects of specific fixatives. (The J Histotechnol 24:173, 2001)

Agreement between rapid onsite and final cytologic interpretations of EUS-guided FNA specimens : Implications for the endosonographer and patient management

BACKGROUND:The practice of onsite cytology interpretation varies across endoscopic ultrasound (EUS) programs in the Untied States and Europe. The value, reliability, and agreement of rapid onsite evaluation (ROSE) compared with final interpretation and its impact on patient management remain largely unknown. We compared agreement between ROSE of EUS-FNA (endoscopic ultrasound-guided fine needle aspiration) specimens with final cytology interpretation and their respective operating characteristics.METHODS:We prospectively evaluated consecutive EUS-FNA specimens obtained by a single endosonographer in the presence of an attending cytopathologist (July 2000–November 2002). The “agreement” between ROSE and final cytology interpretation was assessed by the “kappa” statistic. The frequency and possible reasons for discrepancy between ROSE and final cytologic interpretation were determined.RESULTS:A total of 540 patients (median age 63 yr, 77% white) underwent EUS-FNAs of 656 lesions. These included lymph nodes (LNs, N = 248), solid pancreatic masses (SPMs, N = 229), cystic pancreatic masses (CPM, N = 57), mural lesions (41), bile duct/gallbladder (N = 28), liver (N = 17), mediastinum/lung (N = 17), adrenal (N = 15), spleen (N = 3), and kidney (N = 1). Data were available for onsite evaluation in 607 lesions. Intitial cytology was benign (N = 243), atypical (N = 23), suspicious (24), malignant (300), and indeterminate (N = 17). Out of the 243 benign lesions interpreted by onsite evaluation, five lesions (2.1%) were upgraded to be malignant or suspicious for malignancy on final cytology report. Of the 300 lesions initially reported malignant on ROSE, 294 (98%) remained malignant on the final cytology. There was an excellent agreement between ROSE and final cytologic evaluation (kappa = 84.0%, 95% CI 80.2–87.7), Compared with the true final status, accuracy for final interpretation was slightly higher than for ROSE but was not statistically significant (95.8% vs 93.9%). Scant cellularity remained the most frequent reason for discrepancy, accounting for 21 of 51 discrepancies (41%). Other reasons for discrepancy included: cases requiring an intradepartmental consultation (22%), cases requiring ancillary studies (12%), intra-observer variability (10%), and challenging diagnosis (10%). In three cases, (6%) we were unable to determine the possible reason for discrepancy.CONCLUSION:ROSE of EUS-FNA specimens is highly accurate compared with final cytologic evaluation. Because the diagnosis of malignancy rarely changes, informing our patients and their families and our referring physicians of a cancer diagnosis significantly reduces physician work load and expedites patient management. The majority of discrepancies are related to the nature of the lesion either because it sheds few cells, has challenging morphology, and/or requires additional ancillary studies.

Comparison of Five Antibodies as Markers in the Diagnosis of Melanoma in Cytologic Preparations

We determined the sensitivity and specificity of 3 novel antibodies (microphthalmia transcription factor [Mitf], Melan-A, and tyrosinase) as markers for melanoma in cytologic preparations and compared the results with those of commonly used markers (S-100 protein [S-100] and HMB-45). We stained 72 cell blocks from 40 patients with melanoma and 32 with nonmelanocytic malignant neoplasms with antibodies against S-100, HMB-45, Mitf, Melan-A, and tyrosinase. Histologic correlation was available in more than 95% of cases. Nuclear stainingfor Mitf and cytoplasmic stainingfor S-100, HMB-45, Melan-A, and tyrosinase in more than 10% of tumor cells was considered positive. All 3 novel markers demonstrated sensitivity superior to S-100 and HMB-45. HMB-45, Melan-A, and Mitf demonstrated specificities of 97%. S-100 protein and tyrosinase were less specific. Sensitivity and specificity for the combination Mitf+/Melan-A+ were 95% and 100%, respectively, whereas they were 80% and 100%, respectively, for S-100+/HMB-45+. Mitf Melan-A, and tyrosinase are sensitive markersfor epithelioid melanoma. Mitf and Melan-A seem more specific than S-100 and tyrosinase. An antibody panel consisting of Mitf and Melan-A is superior to a panel of S-100 and HMB-45 in the diagnosis of melanoma in cytologic specimens.

Microdissection of histologic sections: past, present, and future.

Histologic and cytologic changes are central to the diagnosis and classification of many disease processes, particularly neoplasms. The correlation of these changes with genomics, proteomics, and molecular pathways entails refined microdissection techniques that are frequently used to procure a pure population of cells from complex tissue. Here we review the past, present, and future of some of these new advances in microdissection techniques including manual techniques, laser microdissection, laser capture microdissection, and laser catapulting.

Biomarkers in Diagnosis of pancreatic carcinoma in fine-needle aspirates.

This study was undertaken to determine whether recently identified proteins could be translated to clinical practice as markers to distinguish pancreatic adenocarcinoma from chronic pancreatitis on fine-needle aspirate (FNA) samples. Resected pancreatic tissue sections (n = 40) and FNA samples (n = 65) were stained for clusterin-beta, MUC4, survivin, and mesothelin. For each biomarker, the staining patterns in adenocarcinoma and in reactive ductal epithelium were evaluated and compared. Clusterin-beta stained reactive ductal epithelium significantly more frequently than pancreatic adenocarcinoma (P < .001). In comparison, MUC4 and mesothelin were expressed more frequently in pancreatic adenocarcinoma on tissue sections. Positive staining for MUC4 (91% vs 0%; P < .001) and mesothelin (62% vs 0%; P = .01) and absence of staining for clusterin-beta (90% vs 7%; P < .001) were noted significantly more frequently in adenocarcinoma cells than in reactive cells in FNA samples. Clusterin-beta and MUC4 can help distinguish reactive ductal epithelial cells from the cells of pancreatic adenocarcinoma in FNA samples.

In Utero Exposure to Bisphenol A Shifts the Window of Susceptibility for Mammary Carcinogenesis in the Rat

Background Bisphenol A (BPA) is a ubiquitous environmental chemical with reported endocrine-disrupting properties. Objective Our goal in this study was to determine whether prenatal exposure to BPA predisposes the adult rat mammary gland to carcinogenesis. Methods Pregnant rats were treated orally with 0, 25, or 250 μg BPA/kg body weight (BW) from gestation day (GD) 10 to GD21. For tumorigenesis experiments, prenatally exposed female offspring received a single gavage of 7,12-dimethylbenz(a)anthracene (DMBA; 30 mg/kg BW) on postnatal day (PND) 50, or PND100. Results Prenatal exposure of the dam to 250 μg BPA/kg BW combined with a single exposure of female offspring to DMBA on PND100, but not on PND50, significantly increased tumor incidence while decreasing tumor latency compared with the control group. Prenatal exposure of the dam to 250 μg BPA/kg BW, in the absence of DMBA to the female offspring, increased cell proliferation and elicited differential effects at the protein level at PND100 compared with PND50. Differentially regulated proteins in the mammary gland included estrogen receptor-α, progesterone receptor-A, Bcl-2, steroid receptor coactivators, epidermal growth factor receptor, phospho-insulin-like growth factor 1 receptor, and phospho-Raf. Conclusions Our study demonstrates that oral prenatal exposure to BPA increases mammary cancer susceptibility in offspring and shifts the window of susceptibility for DMBA-induced tumorigenesis in the rat mammary gland from PND50 to PND100. These changes are accompanied by differential effects of prenatal BPA exposure on the expression of key proteins involved in cell proliferation.