Martha R. Clarke

Fetal grafting for Parkinson's disease: expression of immune markers in two patients with functional fetal nigral implants.

In a number of centers throughout the world, fetal nigral transplantation is being performed for the treatment of Parkinsons disease (PD). Clinical results have been inconsistent. One parameter that differs among transplant studies is the degree and manner by which patients are immunosuppressed following transplantation. Indeed, the role of the immune system following fetal grafting in humans is not well understood. Recently, two patients from our open label trial that received fetal nigral implants have come to autopsy. These patients were immunosuppressed with cyclosporin for 6 mo posttransplantation and survived for a total of 18 mo postgrafting. Robust survival of grafted dopamine-containing cells was observed in both cases. Immunostaining for HLA-DR revealed a dense collection of cells within grafts from both cases. HLA-DR staining was rarely observed within the host including nongrafted regions of the striatum. A more detailed analysis of immune markers was performed in Case 2. Numerous pan macrophages, T-cells, and B-cells were observed within graft sites located in the postcommissural putamen. In contrast, staining for these immune cells was not observed within the ungrafted anterior putamen. These findings suggest that even in healthy appearing functional nigral implants, grafts are invaded by host immune cells that could compromise their long-term viability and function. Alternatively, immune cells are known to secrete trophic factors, which may ultimately favor graft survival and function. Further work is needed to understand the role of the immune system in fetal grafting.

Prognostic markers in pheochromocytoma

Clinical and histopathological features do not reliably distinguish between benign and malignant pheochromocytomas. Additional markers that might be useful prognostic indicators in the pathological assessment of these tumors are sought. Immunohistochemical expression of MIB-1, Bcl-2, cathepsin B, cathepsin D, basic fibroblast growth factor (bFGF), c-met, and type IV collagenase were studied on formalin-fixed tissue from 33 nonconsecutive cases of pheochromocytoma, selected on the basis of reliable long-term follow-up, to determine associations with malignancy. The study group included 33 patients, 19 men and 14 women, with a mean age of 45 years, including five cases of neurofibromatosis (NF), three familial, and one MEN IIb. Mean follow-up was 63.2 months. Ten patients were determined to have malignant pheochromocytomas by the presence of metastatic disease. Features found to be associated with malignancy included MIB-1 labeling index (5% vs 1%) (P = .0009), male gender (90% vs 43%) (P = .008), extra-adrenal location (40% vs 9%) (P = .03), tumor weight (481 g vs 124 g) (P = .05), and young age (38 years vs 49 years) (P = .05). None of the five cases with NF were malignant (P = .04). S-100 positivity showed a significant (P = .02) but nonlinear association with benign tumors. Absent S-100 correlated with greater tumor weight. Malignancy was not associated with right versus left side or bilaterality, although bilateral tumors were smaller. C-met, bFGF, cathepsin B, cathepsin D, and collagenase were strongly expressed in most tumors and were not predictive of outcome, nor was bcl-2, which was variably expressed. Using multiple logistic regression with malignancy as the dependent variable, MIB-1 continued to show a significant association with malignancy (P = .005) independent of any association with sex, age, or extra-adrenal location. Using a cutoff value of MIB-1 labeling of greater than 3% yielded a specificity of 100% and a sensitivity of 50% in predicting malignancy.

Proliferative activity in pancreatic endocrine tumors: Association with function, metastases, and survival

Endocrine tumors of the pancreas are slow-growing lesions, yet one-third to one-half will metastasize. It is generally accepted that histopathologic features do not reliably predict metastatic potential or outcome. We investigated whether proliferative activity, as determined by MIB-1 labeling, correlated with tumor type, metastasis, or patient survival. Formalin-fixed sections of pancreatic endocrine tumors were immunohistochemically stained for the MIB-1 antibody against Ki-67 using the avidin-biotin complex technique. Labeling index (LI) was determined by counting 1000 consecutive tumor cells in an area of greatest staining intensity at ×400 and expressed as a percentage. The study group included 37 patients, including 10 gastrinomas, 9 insulinomas, 4 glucagonomas, 2 VIPomas, and 12 nonfunctioning tumors. Twenty-one patients had metastases, primarily to regional lymph nodes and the liver. Five patients had MEN I. MIB-1 LI was significantly greater in the nonfunctioning tumors (mean 20.9%) than in the functioning tumors (mean 5.1%) (p = 0.01). LI for functional tumors (insulinomas 6.4%, glucagonoma 4.4%, gastrinomas 3.2%, VIPomas 3.2%) were similar to each other. MIB-1 was significantly higher in those tumors that metastasized (mean 15.6%) compared to those that did not (mean 3.1%), (p = 0.04). All tumors with MIB-1 LI≥10% developed metastases. Logistic regression showed that MIB-1 was a significant predictor of metastases (p = 0.003) after adjusting for functional status. MIB-1 LI also correlated with outcome in that those patients with MIB-1 LI ≥10% had a mean survival of 19 mo compared to 72 mo for those with levels <10% (p = 0.0001). Results of the proportional hazards model showed that MIB-1 remained a significant (p = 0.03) and independent predictor of survival times after adjustment for tumor size and functional status. Higher MIB-1 LI values, were significantly associated with shorter survival times. In conclusion, MIB-1 LI appears to be a useful indicator of metastatic potential and is predictive of outcome in PET.

Interleukin-12 Gene Therapy Prevents Establishment of SCC VII Squamous Cell Carcinomas, Inhibits Tumor Growth, and Elicits Long-term Antitumor Immunity in Syngeneic C3H Mice†

Interleukin‐12 (IL‐12) is an immunostimulatory agent with very promising antitumor activity. Using a retroviral expression vector, the authors have successfully transduced the genes encoding the two subunits of murine IL‐12 to the squamous cell carcinoma cell line, SCC VII. Once IL‐12 gene transcription and protein production were successfully verified, IL‐12 expression was found to inhibit the establishment of SCC VII tumors in syngeneic C3H/HeJ mice inoculated with 1 × 106 SCC VII/IL‐12 viable tumor cells. Mice immunized in this manner and rechallenged with parent SCC VII were capable of rejecting tumor up to 40% of the time. Treatment of established SCC VII tumors with irradiated IL‐12‐producing tumors cells led to significant tumor regression in a high percentage of animals.

Near-tetraploidy in adult acute myelogenous leukemia

Tetraploidy and near-tetraploidy are observed infrequently in hematologic malignancies, most commonly seen in cases of childhood acute lymphoblastic leukemia, and are associated with large blast size. Four cases of adult acute myelogenous leukemia (AML) with tetraploid or near-tetra-ploid karyotypes are reported, along with review of the related literature. AML subtypes included M1, M1, M4, and M5b. Tetraploidy was determined cytogenetically and confirmed by image cytometry (DNA index 2.0). The subjective impression of large blast size was confirmed by image cytometry, demonstrating mean blast nuclear areas of 237, 177, 203, and 216 microns2, (mean 208 microns2) in the cases with tetraploidy, compared to a mean of 134 microns2 in 10 control cases of AML with diploid or near diploid chromosome patterns. The clinical course was variable in the four cases reported. When compared with previously published cases, the occurrence of tetraploidy or near-tetraploidy in adult AML, unlike childhood ALL, does not appear to define a distinct subgroup in terms of FAB classification or to carry prognostic implications.

Extracellular matrix expression in metastasizing and nonmetastasizing adenocarcinomas of the lung

Alterations in extracellular matrix, cell-cell and cell-matrix adhesion, and oncogenes are thought to be important in tumor progression and metastasis. Adenocarcinomas of the lung from 31 patients were studied for immunohistochemical expression of basement membrane molecule type IV collagen, type IV collagenase, and integrins alpha2,3,v adhesion molecules to assess their diagnostic and prognostic importance in pathological stage T2 tumors. The results indicate that with decreasing tumor differentiation, there is a progressive loss of type IV basement membrane collagen (P = .06) and decreased integrin alpha2 expression (P = .03). Type IV collagenase expression was significantly associated with the presence of lymph node metastases, with moderate to strong expression present in 53% T2N1 tumors compared with none (0%) of the T2N0 tumors (P = .008). Integrin alpha(v) was increased in tumors with nodal metastases compared with those without (P = .08). Loss of alpha2 and alpha3 integrins was associated with increased alpha v expression (P = .03). Median survival was 48 months for T2N0 and 20 months for T2N1 (P = .07). In correlating expression of the immunohistochemical markers and survival, type IV collagenase expression was found to be a predictor of survival at a level of P = .07. Measurable alterations in integrins and extracellular matrix, and in particular, expression of matrix-degrading enzyme type IV collagenase may be of prognostic importance in resectable adenocarcinoma of the lung.

Intraoperative imprint cytology for evaluation of mediastinal lymphadenopathy

Frozen-section (FS) analysis of mediastinal lymph nodes is commonly used in the staging of lung cancer and the evaluation of diagnostic tissue at mediastinoscopy. This approach facilitates definitive surgical intervention in a single operation and reduces costs. However, FS analysis can be labor intensive for the pathology department and time-consuming while the patient is anesthetized. Imprint cytology is more rapid than the FS procedure (average, 2 minutes versus 11 minutes per node) and allows more extensive sampling of the specimen. In this prospective study, we compared the diagnostic accuracy of imprint cytology and permanent sections on 121 mediastinal lymph nodes from 38 patients. There were no false-positive results and one false-negative result, although that patient was correctly classified based on positive cytology from another node. The sensitivity was 96.6%, the specificity was 100%, and the predictive value of a positive result was 100%, as no false-positives results were observed. The predictive value of a negative result was 98.9%, and the overall efficiency was 99.2%. These results compare favorably with those in other studies comparing the diagnostic accuracy of imprint cytology with that of FS analysis and with reported accuracy rates of FS technique. Our findings confirm the usefulness of this technique as an adjunct or substitute for FS analysis in the intraoperative pathologic evaluation of mediastinal lymphadenopathy.

Retroperitoneal bronchogenic cyst masquerading clinically and radiologically as a phaeochromocytoma

Abstract Bronchogenic cysts are relatively rare congenital anomalies that represent malformations of the embryonic foregut and are morphologically expressed as maldevelopments of the respiratory system. Anatomically, they can be positioned at any location along the central axis of the respiratory system, but are more commonly discovered in the thorax. Infradiaphragmatic bronchogenic cysts are rare and retroperitoneal ones distinctly unusual. We report a retroperitoneal bronchogenic cyst clinically masquerading as a phaeochromocytoma.

PARATHYROMATOSIS: A CAUSE FOR RECURRENT HYPERPARATHYROIDISM

OBJECTIVE To report a case of parathyromatosis as a cause for recurrent hyperparathyroidism. METHODS We present the case history, laboratory results, operative interventions, and pathologic findings in a 36-year-old woman. Relevant reports from the literature are reviewed. RESULTS Our patient, who had been undergoing long-term hemodialysis because of renal failure, presented with secondary hyperparathyroidism and progressive bone pain. After an uneventful subtotal parathyroidectomy (removal of 3-1/2 glands), her symptoms resolved in conjunction with normalization of parathyroid hormone levels. Subsequently, however, recurrent hyperparathyroidism and severe bone pain necessitated second and third neck explorations, during which parathyromatosis was discovered. A total thyroidectomy was performed because of the bilateral nature of the disease. Postoperatively, the patients bone pain resolved substantially, although her parathyroid hormone levels remained high. CONCLUSION Parathyromatosis is a rare cause of recurrent hyperparathyroidism after parathyroidectomy. It consists of hyperfunctioning parathyroid tissues scattered throughout the neck, due either to intraoperative tissue spillage and subsequent implantation or to hyperplasia of parathyroid rests from embryologic development. This is one of the few case reports of parathyromatosis and the first case report of a mixed form of the disease, consisting of features of both subcapsular parathyroid rests and extracapsular implantation.

Pyruvate inhibits clofibrate-induced hepatic peroxisomal proliferation and free radical production in rats

In an effort to identify the effects of the 3-carbon compound pyruvate on free radical production, we measured hepatic total peroxisomal beta-oxidation and catalase activity and the production of lipofuscin-like products in male Sprague-Dawley rats consuming an adequate diet supplemented with pyruvate, vitamin E, or the peroxisome proliferator and free radical enhancer clofibrate for 22 days (n = 5 in each group). Clofibrate feeding induced hepatomegaly, a fivefold increase in total peroxisomal beta-oxidation activity, and a threefold increase in hepatic lipofuscin-like products (P < .05). Pyruvate but not vitamin E inhibited the increase in liver size by 70% (P < .05). Both pyruvate and vitamin E completely inhibited clofibrate-induced increases in lipofuscin-like products (P < .05). Pyruvate but not clofibrate or vitamin E increased plasma concentrations of the nitric oxide metabolites nitrite and nitrate (P < .05). We conclude that with clofibrate-induced peroxisomal proliferation and free radical production, pyruvate will inhibit peroxisomal proliferation and free radical production, inhibit free radical-induced lipid peroxidation, and enhance metabolism of nitric oxide.