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Dive into the research topics where Robert L. Zimmerman is active.

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Featured researches published by Robert L. Zimmerman.


Human Pathology | 2000

Distinction between dysplasia-associated lesion or mass (DALM) and adenoma in patients with ulcerative colitis

Franz Fogt; Stefan J. Urbanski; Melinda E. Sanders; Emma E. Furth; Robert L. Zimmerman; Julius J. Deren; Amy Noffsinger; Alexander O. Vortmeyer; Christopher J. Hartmann; Robert L. Odze; Charlotte A. Brown

Polyps with epithelial dysplasia in ulcerative colitis (UC) represent either dysplasia-associated lesions or masses (DALMs) or sporadic adenomas. DALMs are frequently associated with associated carcinoma and are an indication for colectomy. Removal of the polyp is treatment of choice for sporadic adenomas. Differentiating between these 2 lesions is not always easy. The goal of this study was to distinguish DALMs from adenomas in patients with UC on a genetic basis. We evaluated genetic alterations in DALMs and compared them with a previously published set of dysplastic polyps in patients with UC that were considered adenomas for the following reasons: (1) polyps were located outside of current active disease; (2) polyps had histological features of sporadic adenomas; and (3) patients displayed a uneventful follow-up after polypectomy (UC-adenomas). In addition, adenomas not associated with UC were studied. Genetic alterations on chromosome 3p were assessed for the markers D3S1766, D3S2409, and D3S2387. LOH with or without microsatellite instability was found in 70%, 37%, and 57% of cases of DALM, respectively. In contrast, UC-adenomas lesions exhibited genetic alterations in 8.3%, 11.7%, and 15.3% for the respective markers. Spontaneous adenomas exhibited genetic alterations in 10.5%, 7.1%, and 0% of cases, which were not significantly different from the UC-adenoma results. These results indicate that UC-adenomas are genetically and biologically similar to sporadic adenomas and that UC-adenomas may biologically represent sporadic adenomas, supporting on a genetic basis the criteria chosen to diagnose adenomas in UC. Genetic markers on chromosome 3p may be useful in the differential diagnosis between DALM and UC-adenomas.


The American Journal of Gastroenterology | 2001

Dieulafoy's lesion of the small bowel causing massive gastrointestinal bleeding: two case reports and literature review

Daniel Blecker; Meena Bansal; Robert L. Zimmerman; Franz Fogt; James D. Lewis; Robert Stein; Michael L. Kochman

Dieulafoys lesions are an often unrecognized cause of obscure, massive GI hemorrhage. Their diagnosis may elude conventional investigations, including upper and lower endoscopy, arteriography, and even laparotomy. In this paper, we report two cases of small-bowel Dieulafoy lesions. The first, a jejunal lesion, occurred in a young patient and was discovered at laparotomy. The second was an ileal Dieulafoys malformation in an older patient. An intraoperative endoscopy with surgical guidance may be needed for definitive localization of this lesion.


Applied Immunohistochemistry & Molecular Morphology | 2001

Expression of survivin, YB-1, and KI-67 in sporadic adenomas and dysplasia-associated lesions or masses in ulcerative colitis.

Franz Fogt; Christopher Poremba; Kazunori Shibao; Hideaki Itoh; Kimitoshi Kohno; Robert L. Zimmerman; Helmut G. Görtz; Barbara Dockhorn-Dworniczak; Stefan J. Urbanski; Nada Alsaigh; David Heinz; Amy Noffsinger; Kenneth R. Shroyer

Sporadic adenomas are said to exhibit an orderly growth pattern with a reversal of proliferative and apoptotic cell distribution as compared with normal colonic crypts. Dysplastic polyps of patients with ulcerative colitis (UC) may represent dysplasia-associated lesions or masses (DALM) with a high associated cancer risk, or, alternatively, may represent sporadic adenomas. Histologic criteria to differentiate between sporadic adenomas and DALM have not focused on the balance between cell renewal and cell loss. The expression of the novel antiapoptosis gene product, survivin, and the proliferation markers, Ki-67 and Y-box binding protein (YB-1), were investigated by immunohistochemical localization in sporadic adenomas and DALM lesions of patients with UC. In adenomas, KI-67 was expressed preponderantly at the luminal aspect of the polyp, whereas its expression was diffuse in DALM. Survivin was detected diffusely in both adenomas and DALM. YB-1 showed positive staining in the deep aspect of adenomatous glands but only to a minor degree at the surface, whereas both deep and diffuse expression patterns of YB-1 were seen in DALM. The authors conclude that DALM and sporadic adenomas exhibit different patterns of cellular proliferation and that molecular markers of cell proliferation, Ki-67 and YB-1, may be useful to distinguish sporadic adenomas from DALM. However, the similar expression of survivin suggests that the underlying mechanisms that regulate apoptotic cell death are uniform in these lesions.


Obstetrics & Gynecology | 2003

Histologic features of uterine leiomyomata treated with microsphere embolization

Franz Fogt; Nicolai Hinds; Robert L. Zimmerman

BACKGROUND Therapeutic embolization is a new treatment for symptomatic leiomyomata. Material available in the United States for uterine embolization includes precisely calibrated hydrophilic microporous microspheres made of a cross-linked acrylic copolymer. CASE A 42-year-old woman with a longstanding history of symptomatic leiomyomatous uterus underwent uterine artery embolization with microspheres. Because of continuous intractable pelvic pain, an abdominal hysterectomy and bilateral salpingo-oophorectomy was performed. The gross and histologic findings included large amounts of microspheres and pus within the uterine cavity, infarcted leiomyomata with microspheres, and intravascular microspheres within hyalinized leiomyomas. CONCLUSION Microsphere embolization leads to hyalinizing and ischemic necrosis with residual microsphere material in the myometrium, uterine cavity, fallopian tubes, and ovaries.


Urology | 1998

Utility of the Bard BTA Test in Detecting Upper Urinary Tract Transitional Cell Carcinoma

Robert L. Zimmerman; Demetrius H. Bagley; Clementine Hawthorne; Marluce Bibbo

OBJECTIVES The Bard BTA test has been shown in early studies to be useful in diagnosing transitional cell carcinoma (TCC) of the bladder. However, the utility of this test has not been evaluated for TCC of the upper urinary tract. We therefore evaluated the clinical utility of the BTA test for upper urinary TCC. METHODS We tested 71 specimens from the ureter and/or renal pelvis in 22 patients with a history or clinical suspicion for TCC and 9 patients with benign disorders. RESULTS When compared to cytologic diagnoses, BTA had a sensitivity of 65%, a specificity of 40% (when correlated with clinical history), a false-positive rate of 33%, and a false-negative rate of 62%. The test had a positive predictive value of 83% and a negative predictive value of 32%. CONCLUSIONS The BTA does not have any clinical value in detecting upper urinary tract TCC.


Journal of Heart and Lung Transplantation | 2003

Evaluation of host stem cell-derived cardiac myocytes in consecutive biopsies in long-term cardiac transplant patients.

Franz Fogt; Kurt Beyser; Christopher Poremba; Robert L. Zimmerman; Josef Rüschoff

BACKGROUND Bone marrow-derived stem cells are involved in tissue formation in transplanted organs. In human renal cell transplants, recipient-specific cells have been shown to participate in regeneration of interstitial tissue. In hepatic transplants, hepatocytes with a recipient sex chromosome pattern have been observed. Recruitment of stem cells in repair and regeneration of cardiac myocytes has been demonstrated in experimental ischemia. Recently, cardiac antral myocytes of recipient origin have been shown to populate transplanted hearts in gender-mismatched transplants. METHODS Using the fluorescence in situ hybridization (FISH) technique we examined serial post-transplant right ventricular biopsies and sections of ventricle (at time of autopsy) of 4 gender-mismatched female-to-male transplanted hearts (graft survival 0.5 to 10 years, mean 5.1 years) for Y chromosomes within cardiac myocytes. RESULTS We detected recipient-specific sex chromosomal patterns in single rare cardiac myocytes in 1 case in a serial biopsy after 7 years of transplant survival. The other serial biopsies, as well as the final sections at autopsy, showed no recipient pattern chromosomes within the myocytes. In addition, 2 cases demonstrated Y chromosomes in the smooth muscle of intracardiac arteries. CONCLUSION Development of recipient marrow-derived stem cells into functional myocytes in the ventricle of transplanted hearts is a rare feature. The higher percentage of stem cell population in the cardiac atria may be a feature of tissue repair and/or an early feature of transplant physiology. Similar to other transplant organs, recipient stem cells are involved in tissue neovascularization.


Acta Cytologica | 1998

Fine needle aspiration diagnosis of a pulmonary metastasis from a cutaneous adenoid cystic carcinoma. A case report.

Robert L. Zimmerman; Marluce Bibbo

BACKGROUND Primary cutaneous adenoid cystic carcinomas (CACC) rarely metastasize to the lung. The few documented cases have been diagnosed by surgical biopsy. CASE An 82-year-old female presented with an enlarging lung mass 15 years after being diagnosed with CACC. The diagnosis of metastatic adenoid cystic carcinoma was made following a computed tomography-guided fine needle aspiration (FNA) biopsy. CONCLUSION Metastatic CACC in the lung can be diagnosed by FNA. Knowledge of the patients clinical history and morphologic variants of CACC is important in making the diagnosis.


Archives of Pathology & Laboratory Medicine | 2000

Cytologic Atypia in a 53-Year-Old Man With Finasteride-Induced Gynecomastia

Robert L. Zimmerman; Franz Fogt; Dennis Cronin; Randall Lynch

Finasteride has been associated with the development of gynecomastia. Although cytoplasmic vacuolization has been noted in prostatic epithelium in men taking this drug, we found no documentation of the cytologic changes in finasteride-associated gynecomastia. We present the case of a 53-year-old man who developed unilateral gynecomastia following finasteride therapy for alopecia. A fine-needle aspiration biopsy of the mass was diagnosed as adenocarcinoma on the basis of nuclear atypia and particularly because of cytoplasmic vacuolization. Subsequent excisional biopsy revealed benign gynecomastia with no evidence of malignant change. The ductal epithelium did exhibit cytoplasmic vacuolization similar to that described in the prostate following finasteride therapy. We believe this is the first reported case documenting the cytologic changes seen in gynecomastia secondary to finasteride therapy. Cytoplasmic vacuolization in this setting should not be considered evidence of malignancy in men with gynecomastia. As with gynecomastia in general, extreme caution should be used before rendering a cytologic diagnosis of malignancy.


Modern Pathology | 2001

Glucose Transporter Glut-1 Is of Limited Value for Detecting Breast Carcinoma in Serous Effusions

Robert L. Zimmerman; Shanth Goonewardene; Franz Fogt

Diagnosing breast carcinoma that has metastasized to body cavity fluids can be difficult. Recently, immunostaining for the facultative glucose transporter Glut-1 has been described as a sensitive and specific means of detecting carcinomas in effusions. However, only five cases of breast carcinoma were studied. We examined Glut-1 specifically as a means of detecting breast carcinoma in effusion cytology. Using avidin-biotin immunocytochemistry, cell block material from 31 cases of breast carcinoma metastatic to body cavity effusions and 33 cases of benign effusions were studied. All cases were immunostained with the Glut-1 antibody. An additional set of slides from these same cases was stained for mucin using the Mayers mucicarmine technique. Slides were graded for percentage of cells exhibiting immunoreactivity for Glut-1 or for the presence of mucin. Results of staining for both Glut-1 alone and in combination with mucicarmine were compared between the benign and malignant groups. Of the breast cancer cases, 19 of 31 (61%) were immunoreactive for Glut-1, and 25 of 31 (81%) were positive for either Glut-1 or mucicarmine. One of the 33 (3%) benign cases was immunoreactive for Glut-1, and none were positive for mucin. These data suggest that using Glut-1 as a single immunostain or in conjunction with mucicarmine is a specific but modestly sensitive means of detecting breast carcinoma in this cytologic setting.


The American Journal of Gastroenterology | 2004

Low prevalence of loss of heterozygosity and SMAD4 mutations in sporadic and familial juvenile polyposis syndrome-associated juvenile polyps.

Franz Fogt; Charlotte A. Brown; Kamrari Badizadegan; Robert L. Zimmerman; Robert D. Odze

BACKGROUND:Juvenile polyps (JP) may develop sporadically or may be associated with the familial juvenile polyposis syndrome (FJPS). In FJPS, the epithelium is susceptible to dysplasia and, ultimately adenocarcinoma. However, the mechanisms involved in this transformation are unknown. Since the epithelium in colorectal carcinogenesis undergoes a stepwise genetic progression, the purpose of this study was to determine if loss of heterozygosity (LOH) abnormalities can aid in the differentiation between sporadic and FJPS-associated polyps.DESIGN:Ninety-one routinely-processed JP from three groups of patients were evaluated for this study. Group 1 included 39 polyps from 39 patients with a single JP and no personal or family history of FJPS; group 2 consisted of 24 polyps from 15 patients with 2–5 JP and no history of FJPS; and group 3 included 29 polyps from 22 patients with ≥5 polyps either with (7) or without (15) a family history of FJPS. Epithelium from typical, atypical, and overtly dysplastic polyps, when present (2 cases in group 3 only), were evaluated separately by microdissection and PCR analysis for LOH of APC, p53, 3p, 9p, and mutations in exon 9 of the SMAD4 gene.RESULTS:SMAD4 mutations were observed in 3 polyps from 2 patients in group 3 (10% of informative cases; p < 0.05 vs group 1), but not in any of the polyps from the other two groups. Overall, LOH of APC, p53, 3p, and 9p were detected in 1%, 15%, 10%, and 4% of JPs, but no differences were observed between the three clinical groups. Two polyps, both in group 3, with definite dysplasia did not show any genetic alterations. The morphologic appearance of the polyps was not a reliable feature in helping to differentiate sporadic from FJPS-associated polyps.CONCLUSIONS:LOH of APC, p53, 3p, and 9p may not be involved in the carcinogenic pathway of FJPS-associated polyps. SMAD4 gene mutations show a low sensitivity but a high specificity for FJPS.

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Franz Fogt

University of Pennsylvania

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Marluce Bibbo

Thomas Jefferson University Hospital

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Melissa Burke

Thomas Jefferson University

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