Proteomic characterization of high-density lipoprotein particles in patients with non-alcoholic fatty liver disease.

BACKGROUND: Metabolic diseases such as obesity and diabetes are associated with changes in high-density lipoprotein (HDL) particles, including changes in particle size and protein composition, often resulting in abnormal function. Recent studies suggested that patients with non-alcoholic fatty liver disease (NAFLD), including individuals with non-alcoholic steatohepatitis (NASH), have smaller HDL particles when compared to individuals without liver pathologies. However, no studies have investigated potential changes in HDL particle protein composition in patients with NAFLD, in addition to changes related to obesity, to explore putative functional changes of HDL which may increase the risk of cardiovascular complications. METHODS: From a cohort of morbidly obese females who were diagnosed with simple steatosis (SS), NASH, or normal liver histology, we selected five matched individuals from each condition for a preliminary pilot HDL proteome analysis. HDL particles were enriched using size-exclusion chromatography, and the proteome of the resulting fraction was analyzed by liquid chromatography tandem mass spectrometry. Differences in the proteomes between the three conditions (normal, SS, NASH) were assessed using label-free quantitative analysis. Gene ontology term analysis was performed to assess the potential impact of proteomic changes on specific functions of HDL particles. RESULTS: Of the 95 proteins identified, 12 proteins showed nominally significant differences between the three conditions. Gene ontology term analysis revealed that severity of the liver pathology may significantly impact the anti-thrombotic functions of HDL particles, as suggested by changes in the abundance of HDL-associated proteins such as antithrombin III and plasminogen. CONCLUSIONS: The pilot data from this study suggest that changes in the HDL proteome may impact the functionality of HDL particles in NAFLD and NASH patients. These proteome changes may alter cardio-protective properties of HDL, potentially contributing to the increased cardiovascular disease risk in affected individuals. Further validation of these protein changes by orthogonal approaches is key to confirming the role of alterations in the HDL proteome in NAFLD and NASH. This will help elucidate the mechanistic effects of the altered HDL proteome on cardioprotective properties of HDL particles.

Extracolonic gastrointestinal tract morphologic findings in a case of pseudomembranous collagenous colitis.

"Pseudomembranous collagenous colitis" is a morphologic variant of collagenous colitis in which active inflammation with pseudomembrane formation is prominent and which has been associated with infectious, toxic, and ischemic etiologies. However, extracolonic morphologic findings in patients with pseudomembranous collagenous colitis have not been previously described. Here, we present a case of a patient with pseudomembranous collagenous colitis with abnormal extracolonic findings. These include gastric antral mucosa with histologic features reminiscent of ischemic injury and reactive gastropathy with intraepithelial lymphocytosis and partial villous atrophy in the duodenal and ileal biopsies. The findings in the small intestinal biopsies resemble those seen in enteric mucosa in patients with conventional collagenous colitis. Our pathologic findings as well as the clinical course of the patient further emphasize the clinical and histologic similarities shared by pseudomembranous collagenous colitis and conventional collagenous colitis.

Gastrointestinal pathology of autologous graft-versus-host disease following hematopoietic stem cell transplantation: a clinicopathological study of 17 cases.

Graft-versus-host disease is the major complication after allogeneic hematopoietic stem cell transplantation and is attributable to donor T-cell recognition of recipient alloantigens. In patients undergoing autologous hematopoietic stem cell transplantation in which there is no genetic disparity to induce an alloresponse, a syndrome similar to allogeneic graft-versus-host disease has been described. Designated as autologous graft-versus-host disease, it typically involves the skin and has reportedly caused little morbidity in this patient population. Recent data, however, suggest that autologous graft-versus-host disease can cause significant disease in the gastrointestinal tract, but its pathological spectrum of abnormalities and disease incidence are not well established. We report the development of autologous graft-versus-host disease following hematopoietic stem cell transplantation in 17 patients (15 with multiple myeloma) based on 388 autologous stem cell transplants carried out at our institution over a 6-year period. This represents a total incidence rate of 4% and among those transplanted for multiple myeloma, 6%. In all, 16 of the 17 patients had colonic biopsies performed for the diagnostic evaluation of persistent diarrhea. Biopsies in all 16 patients showed pathological evidence for graft-versus-host disease and were graded using standard grading criteria established for allogeneic graft-versus-host disease. Grades ranged from mild (grade 1/4) to severe (grade 4/4). Changes secondary to medication or infection were excluded. Responses to steroid and immunosuppressive therapy were variable but improved with continuing institutional experience. Outcomes ranged from a prompt, complete resolution of symptoms to death. Patients treated with autologous hematopoietic stem cell transplantation, particularly those with multiple myeloma, may develop a potentially life-threatening syndrome pathologically identical to allogeneic graft-versus-host disease. This diagnosis must be considered when interpreting biopsies from patients with gastrointestinal symptoms following autologous hematopoietic stem cell transplantation.

Effects of interventions on intra- and interobserver agreement on interpretation of nonalcoholic fatty liver disease histology.

Accurate and reproducible interpretation of nonalcoholic fatty liver disease (NAFLD) histology has significant clinical and research-related implications. We evaluated the impact of 2 interventions ([1] review of illustrative histologic images of NAFLD with the study pathologists; [2] use of a scoring sheet with written diagnostic criteria for different NAFLD phenotypes) on intra- and interobserver agreement on interpretation of NAFLD histology. Before and after the interventions, 2 pathologists twice read 65 liver biopsies done for evaluation of suspected NAFLD. The intra- and interobserver agreement was highest on assessment of steatosis and fibrosis. The interventions significantly improved the intraobserver agreement only on assessment of hepatocellular ballooning. The interobserver agreement was only fair on assessment of lobular inflammation, ballooning, and diagnostic classification and did not improve after the interventions. Methods to improve interobserver agreement on assessment of lobular inflammation and ballooning are needed and would likely increase pathologists' agreement on NAFLD diagnostic classification.

Impact of Clostridium difficile on inflammatory bowel disease.

BACKGROUND & AIMS: Clostridium difficile-associated disease has increased significantly in North American medical centers. The impact of C difficile on patients with IBD (Crohn's disease, ulcerative colitis) at the present time is unknown. METHODS: A retrospective, observational study evaluating IBD patients followed in a referral center to evaluate the impact of C difficile was performed. Diagnosis was confirmed with stool toxin analysis. Demographic information, diagnosis, anatomic location, IBD therapy, antibiotic exposure, hospitalizations, and surgeries were recorded. Available endoscopic and histologic data were evaluated. RESULTS: Rate of C difficile infection increased from 1.8% of IBD patients in 2004 to 4.6% in 2005 (P < .01). Proportion of IBD patients within the total number of C difficile infections at our institution increased from 7% in 2004 to 16% in 2005 (P < .01). IBD colonic involvement was found in the majority of C difficile-infected patients in 2005 (91%), and the majority contracted infection as an outpatient (76%). Antibiotic exposure was identified in 61% of IBD patients with C difficile infection in 2005. Pseudomembranes and fibrinopurulent eruptions were not seen endoscopically or histologically. During 2004-2005 more than half of the infected IBD patients required hospitalization, and 20% required colectomy. Univariate and multivariate analysis identified maintenance immunomodulator use and colonic involvement as independent risk factors for C difficile infection in IBD. CONCLUSIONS: C difficile infection has increased significantly in IBD patients and negatively impacts clinical outcome. Increased vigilance regarding this infection in IBD patients with colitis activity is warranted.

Pneumocystis carinii pneumonia with pleural effusion in a non-HIV host.

Pneumocystis carinii pneumonia (PCP) is a life-threatening opportunistic infection that occurs in immunocompromised hosts, especially patients with the acquired immunodeficiency syndrome (AIDS). However, this infection is increasing in frequency in other immunosuppressed patients, including organ transplant recipients and those with malignancy who are treated with chemotherapeutic regimens. It carries a relatively high mortality in the non-human immunodeficiency virus (HIV) population. Pleural involvement is rare with PCP; all reported cases in the literature are associated with HIV disease and characterized as small effusions. We report a case of a renal transplant recipient with PCP and moderate-sized pleural effusion with pneumocystis cysts.

Vascular endothelial growth factor and DPC4 predict adjuvant therapy outcomes in resected pancreatic cancer.

Angiogenesis is important for pancreatic cancer progression, but its role in predicting response to therapy is not known. We investigated the association of various angiogenic factors and intratumoral microvessel density (IMD) with adjuvant therapy and survival in resected pancreatic cancer. Tissue cores from a multi-institutional retrospective series of resected patients were used to build a pancreatic cancer tissue microarray. Vascular endothelial growth factor (VEGF), platelet-derived endothelial cell growth factor (PD-ECGF), CD31 (for IMD), and DPC4 expression were determined using immunohistochemistry. Expression of VEGF and PD-ECGF, both proangiogenic factors, was observed in 70 (56%) and 75 (59%) of 124 tumors, respectively. Expression of DPC4, an angiogenesis inhibitor, was observed in 59 of 124 (48%) tumors. VEGF expression correlated significantly with increased IMD (P=.03), as did loss of antiangiogenic DPC4 (P=.05). PD-ECGF expression did not correlate with IMD. Use of adjuvant therapy was associated with increased survival in patients with VEGF-positive tumors (18.8 [treated] versus 11.2 [untreated] months; hazard ratio [HR]=0.38, 95% confidence interval [CI], 0.19-0.76; P=.005), but not in patients with VEGF-negative tumors. Similarly, improved survival was observed in patients with high IMD (16.3 [treated] versus 11.2 [untreated] months; HR=0.44, 95% CI, 0.23-0.87; P=.02) and in patients with loss of DPC4 (20.3 [treated] versus 11.2 [untreated] months; HR=0.31, 95% CI, 0.14-0.67; P=.002), but not in those with low IMD or normal DPC4 expression. VEGF (stimulator) and DPC4 (inhibitor) are important regulators of pancreatic tumor angiogenesis and predictive of benefit from adjuvant therapy. Adjuvant therapy may have both antiangiogenic and cytotoxic effects. Addition of anti-VEGF agents to adjuvant regimens may further improve outcomes.

Thymidylate synthase expression predicts the response to 5-fluorouracil-based adjuvant therapy in pancreatic cancer.

PURPOSE: Thymidylate synthase (TS) is the target enzyme for 5-fluorouracil (5-FU), and TS expression may determine clinical response and survival after therapy with 5-FU in colorectal cancer. 5-FU is also widely used in the adjuvant therapy of pancreatic cancer. Therefore, we explored the hypothesis that TS expression was associated with patient prognosis and the response to adjuvant therapy in pancreatic cancer. EXPERIMENTAL DESIGN: Cylindrical tissue cores from a large retrospective, nonrandomized series covering 132 resected patients were used to build a pancreatic cancer tissue microarray. TS expression was determined using immunohistochemistry. RESULTS: High intratumoral TS expression and low intratumoral TS expression were present in 83 of 132 (63%) and 49 of 132 (37%) tumors, respectively. Median survival among patients with low intratumoral TS expression (18 months) was longer than that among patients with high TS expression (12 months). In multivariate analysis, more advanced pathological stage [risk ratio (RR) = 1.70; P = 0.015], poorly differentiated histology (RR = 1.71; P = 0.015), management with adjuvant therapy (RR = 0.49; P = 0.011), and high TS expression [RR = 1.66; 95% confidence interval (CI) = 1.05-2.63; P = 0.029] were independent predictors of mortality. The risk of death was significantly reduced by any adjuvant therapy (RR = 0.40; 95% CI = 0.18-0.90; P = 0.001) among patients with high TS expression. This difference in survival among patients with low- and high-TS-expressing tumors became more significant when the analysis was restricted to the 73 patients receiving 5-FU-based adjuvant therapy (RR = 0.37; 95% CI = 0.16-0.86; P = 0.0006). In contrast, 5-FU-based adjuvant therapy did not influence survival among patients with low-TS-expressing pancreatic cancer. CONCLUSIONS: High TS expression is a marker of poor prognosis in resected pancreatic cancer. Patients with high intratumoral TS expression benefit from adjuvant therapy.

Case report: "Popcorn" dystrophic ileal calcification in a patient with Crohn's disease.

Small bowel calcification is a rare finding, often associated with chronic infection or small intestinal neoplasms. The authors report a patient who developed dystrophic ileal calcification in the setting of medically refractory Crohn's disease. The patient had longstanding, obstructive ileal Crohn's disease, treated with corticosteroids for a 10-year period. Diffuse terminal ileal calcification was evident on radiographic studies, including plain films as well as abdominal CT scan. The patient underwent successful resection of the diseased segment of small bowel and has done well over the ensuing 3-year period. Dystrophic calcification is a rare complication of long-standing chronic inflammation in Crohn's disease that may occur in the absence of adenocarcinoma or chronic infection.

Improved immunohistochemical evaluation of micrometastases in sentinel lymph nodes of cutaneous melanoma with 'MCW melanoma cocktail'--a mixture of monoclonal antibodies to MART-1, Melan-A, and tyrosinase.

BACKGROUND: MART-1, Melan-A, and Tyrosinase have shown encouraging results for evaluation of melanoma micrometastases in sentinel lymph nodes, as compared to conventionally used S-100 protein and HMB-45. To achieve higher sensitivity, some studies recommend evaluation of three sections, each at intervals of 200 micron. This would mean, routine staining of three adjacent sections in each of the three clusters at intervals of 200 micron, requiring nine slides resulting in added expense. If a cocktail of these antibodies could be used, only one section would be required instead of three generating significant cost savings. METHODS: We prepared a combination of monoclonal antibodies to these three immunomarkers in optimized dilutions (MART-1, clone M2-7C10, dilution 1:500; Melan-A, clone A103, dilution 1:100; and Tyrosinase, clone T311, dilution 1:50) and designated it as 'MCW melanoma cocktail'. Formalin-fixed paraffin-embedded tissue sections of sentinel lymph nodes from patients with cutaneous melanoma, without macro-metastases were evaluated with this cocktail. RESULTS: Melanoma micrometastases were easily detectable with the cocktail in 41 out of 188 slices (8/24 cases). The diagnostic accuracy amongst five pathologists did not show statistically significant difference. Out of 188 slices, 78 had adjacent sections immunostained individually with MART-1 and Melan-A during our previous study. Of these 78 slices, 21 were positive for melanoma micrometastases with MART-1 and Melan-A individually. However, the adjacent section of these slices immunostained with the cocktail detected metastases in four additional slices. Thus, MART-1 and Melan-A could not detect melanoma micrometastases individually in 16% (4/25) of slices positive with the cocktail. Benign capsular nevi were immunoreactive for the cocktail in 4.8% (9/188) slices. All 81 slices of negative test controls (sentinel lymph nodes of mammary carcinoma) were interpreted correctly as negative for melanoma micrometastases. CONCLUSIONS: The melanoma cocktail facilitated easy interpretation of melanoma micrometastases in sentinel lymph nodes with high interobserver agreement. There was improvement in detection rate with the cocktail as compared to MART-1 and Melan-A individually. Furthermore, this approach facilitates cost savings.

Intraoperative cytology increases the diagnostic accuracy of frozen sections for the confirmation of various tissues in the parathyroid region.

The identification of parathyroid gland tissue and its distinction from adjacent structures such as thyroid gland, lymphoid, fibroadipose, and, rarely, thymic tissues on frozen section (FS) may be challenging owing to freezing artifact. Intraoperative cytology (IC) provides valuable complementary morphologic details. We evaluated 72 specimens with IC alone (group 1), followed by interpretation with FS to reach a final interpretation using IC and FS together (group 2). An additional 105 specimens were evaluated by FS alone (group 3). Permanent section diagnosis was used as the "gold standard." Sensitivity and specificity were 100% for group 2, compared with lower values for group 1 (98% and 100%, respectively) and group 3 (94% and 94%, respectively). IC is a valuable adjunct to FS during intraoperative consultation for evaluation of tissue in a parathyroid location.

Cystic pancreatic neuroendocrine tumors: is preoperative diagnosis possible?

Pancreatic neuroendocrine tumors rarely undergo cystic degeneration leading to a radiologic appearance, which is often interpreted as a pancreatic mucinous cystadenoma or pseudocyst. We reviewed our experience with 38 neuroendocrine tumors, four of which were cystic, and 24 other cystic pancreatic tumors (mucinous cystadenoma [n = 5], cystadenocarcinoma [n = 6], serous cystadenoma [n = 3], solid/cystic papillary neoplasm [n = 3], intraductal papillary mucinous tumor [n = 6], and mucinous adenocarcinoma [n = 1]) managed operatively between 1990 and 2000. This review was undertaken to identify clinical and pathologic features useful for preoperative diagnosis of cystic neuroendocrine tumors. Two of the four patients with cystic neuroendocrine tumors presented with abdominal pain, one patient was asymptomatic, and one patient had hypoglycemia. Three of the four cystic neuroendocrine tumors were identified by CT scan, and none were biopsied preoperatively. Preoperative diagnoses included mucinous cystadenoma in two patients (n = 2), pancreatic cystic neoplasm in one patient, (n = 1) and insulinoma in one patient (n = 1). All four cystic neuroendocrine tumors were benign and were completely resected (distal pancreatectomy [n = 2], enucleation [n = 2]). Cystic neuroendocrine tumors are difficult to diagnose preoperatively because the majority of these tumors are nonfunctional, and CT does not differentiate these tumors from other cystic neoplasms. Cystic neuroendocrine tumors represent a subgroup of pancreatic cystic and neuroendocrine tumors with malignant potential. Their high resectability rate further supports the role of surgical exploration and resection in the treatment of pancreatic cystic neoplasms.

Cystic pancreatic neoplasms: enucleate or resect?

Asymptomatic cystic pancreatic neoplasms are being detected by abdominal imaging with increasing frequency. Enucleation of small cystic neoplasms can be performed without recurrence but has been associated with a higher incidence of pancreatic fistula. Thus the procedure has been modified to include intraoperative ultrasound imaging and closure of the pancreatic defect. This analysis was performed to determine whether these modifications have improved operative outcome. Thirty patients with mucinous cystic neoplasms (n=16), serous cystadenomas (n=10), and cystic islet cell tumors (n=4) were studied. Enucleation was performed in 11 patients (7 with mucinous cystic neoplasms, 2 with serous cystadenomas and 2 with islet cell tumors), whereas 19 underwent resection of cystic tumors (pancreatoduodenectomy in 8 and distal pancreatectomy in 11). The mean groups did not differ with regard to age (57 years), gender (73% female), presentation (63% incidental), or site (43% head, neck, or uncinate). Patients undergoing enucleation had smaller tumors (2.2 vs. 4.7 cm, P<0.01) that were less likely to be in the tail (9% vs. 42%). Operative time was significantly shorter in the enucleation group (199 vs. 298 minutes, P<0.01). Blood loss also was significantly reduced in the enucleation group (114 vs. 450 ml, P<0.001). Pancreatic fistula rates (27% vs. 26%) and length of hospital stay (12.6 vs. 15.7 days) were similar in the two groups. Enucleation of benign cystic pancreatic neoplasms reduces operative time and blood loss without increasing postoperative complications or length of stay. Therefore enucleation should be the standard operation for small benign cystic neoplasms in the uncinate, head, neck, and body of the pancreas.

Adrenal cortical adenoma with adrenalin-type neurosecretory granules clinically mimicking a pheochromocytoma.

Adrenal tumors often present with clinical features that are specific and unique to their endocrine metabolism. When these features are in conflict with the pathologic appearance of the tumor, there can be great consternation for both the pathologist and the surgeon. In the case reported herein, an adrenalectomy was performed for clinical features of pheochromocytoma that on gross and histologic examination had the pathologic features of an adrenal cortical adenoma. Electron microscopy subsequently revealed that the tumor cells contained adrenalin-type granules, explaining the clinical outcome. It is crucial for both the surgeon and the surgical pathologist to be aware of this possibility when the clinical and pathologic features of an adrenal tumor are not congruent.

Fatty metamorphosis and other patterns in fibrous dysplasia.

BACKGROUND: Interpretation of small biopsy fragments from suspected lesions of fibrous dysplasia with unusual clinical and/or radiological features may be challenging due to wide histomorphological spectrum of stromal appearances. Awareness of these variations should improve diagnostic confidence. METHODS: We retrospectively studied 26 cases of fibrous dysplasia (F- 19, M- 7; Ages ranged from 10 to 53 years) with confirmed diagnosis. The sites of the lesions were skull bones (9), humerus (1), femur (8), tibia (2), fibula (3), talus (1), mandible (1), and maxilla (1). RESULTS: Different stromal patterns, variably admixed with the classical pattern, were observed in 58%(15/26) of the cases. 20%(3/15) of these had more than one pattern. Focal fatty metamorphosis as groups of fat cells in the central portion of the lesion in the stroma of fibrous dysplasia between osseous trabeculae was observed in 23%(6/26) cases. Other patterns included myxoid stroma in 16%(4/26), collagenization of stroma in 12%(3/26), stroma rich pattern (with paucity of trabeculae) in 12%(3/26), foci of few foam cells in 23% (6/26), and calcified spherules in 12%(3/26). Focal osteoblastic rimming of trabeculae was observed only in 4%(1/26). CONCLUSIONS: Various stromal variations and previously unreported fatty metamorphosis were frequently observed in fibrous dysplasia.

Accuracy of cytologic interpretation of pancreatic neoplasms by fine needle aspiration and pancreatic duct brushings.

OBJECTIVE: To investigate the accuracy of fine needle aspiration (FNA) specimens and pancreatic duct brushings in the detection of pancreatic lesions and to compare the results with follow-up biopsy and/or surgical interpretation. STUDY DESIGN: We reviewed a total of 57 specimens (37/20), 37 FNA specimens and 20 pancreatic duct brushings, from 45 patients treated at Froedtert Memorial Lutheran Hospital, affiliated with the Medical College of Wisconsin, Milwaukee, over a 4-year period. The FNA and brushing samples were categorized as follows: positive for malignancy (21/3 = 24), suspicious for malignancy (8/7 = 15) and atypical (8/10 = 18). The results were then correlated with the tissue diagnosis. RESULTS: The 24 cytologic samples positive for malignancy included 23 (20/3) pancreatic ductal carcinoma (CA) and 1 (1/0) neuroendocrine CA; in the suspicious category, 11 (6/5) were pancreatic ductal CA; 2 (0/2) mucinous neoplasms and (2/0) neuroendocrine neoplasms; in the atypical category; 2 (2/0) suggestive of mucinous neoplasia, 1 (1/0) suggestive of serous neoplasia and 9 (2/7) favor reactive; and 6 (3/3) without further categorization. Tissue diagnoses were available in 26 cases: 12 (10/2) cases positive for malignancy, 8 (5/3) suspicious for malignancy and 6 (5/1) atypical. The 12 cytologically positive cases confirmed by histology showed 10 ductal CA, 1 neuroendocrine CA and 1 negative. All 8 cases (100%) suspicious for malignancy revealed positive results, including 5 ductal CA, 1 neuroendocrine neoplasm, 1 mucinous cystic neoplasm and 1 lymphoma. Of the 6 atypical lesions, 1 showed ductal CA, 2 mucinous cystic neoplasm and 3 chronic pancreatitis. CONCLUSION: Pancreatic FNA and duct brushings [table: see text] are accurate methods in identifying pancreatic lesions, particularly ductal CA. Accuracy can be improved in the case of mucinous and other lesions with adequate cellularity of the smear and recognizing the limitations of brush samples in the case of mucinous cystic lesions. False negative results may occur in cases of poor representation of malignant cells or poor sampling.

PTTG1 overexpression in adrenocortical cancer is associated with poor survival and represents a potential therapeutic target.

BACKGROUND: Adrenocortical carcinoma (ACC) is associated with poor survival rates. The objective of the study was to analyze ACC gene expression profiling data for prognostic biomarkers and therapeutic targets. METHODS: We profiled 44 ACC and 4 normal adrenals on Affymetrix U133 Plus 2 expression microarrays. Pathway and transcriptional enrichment analysis was performed. Protein levels were determined by Western blot. Drug efficacy was assessed against ACC cell lines. Previously published expression datasets were analyzed for validation. RESULTS: Pathway enrichment analysis identified marked dysregulation of cyclin-dependent kinases and mitosis. Overexpression of PTTG1, which encodes securin, a negative regulator of p53, was identified as a marker of poor survival. Median survival for patients with tumors expressing high PTTG1 levels (log2 ratio of PTTG1 to average ß-actin <-3.04) was 1.8 years compared with 9.0 years if tumors expressed lower levels of PTTG1 (P < .0001). Analysis of a previously published dataset confirmed the association of high PTTG1 expression with a poor prognosis. Treatment of 2 ACC cell lines with vorinostat decreased securin levels and inhibited cell growth (median inhibition concentrations of 1.69 µmol/L and 0.891 µmol/L, for SW-13 and H295R, respectively). CONCLUSION: Overexpression of PTTG1 is correlated with poor survival in ACC. PTTG1/securin is a prognostic biomarker and warrants investigation as a therapeutic target.

Cardiac injury after 10 gy total body irradiation: indirect role of effects on abdominal organs.

The objective of this study was to determine whether radiation-induced injury to the heart after 10 Gy total body irradiation (TBI) is direct or indirect. Young male WAG/RijCmcr rats received a 10 Gy single dose using TBI, upper hemi-body (UHB) irradiation, lower hemi-body (LHB) irradiation, TBI with the kidneys shielded or LHB irradiation with the intestines shielded. Age-matched, sham-irradiated rats served as controls. The lipid profile, kidney injury, heart and liver morphology and cardiac function were determined up to 120 days after irradiation. LHB, but not UHB irradiation, increased the risk factors for cardiac disease as well as the occurrence of cardiac and kidney injury in a way that was quantitatively and qualitatively similar to that observed after TBI. Shielding of the kidneys prevented the increases in risk factors for cardiac disease. Shielding of the intestines did not prevent the increases in risk factors for cardiac disease. There was no histological evidence of liver injury 120 days after irradiation. Injury to the heart from irradiation appears to be indirect, supporting the notion that injury to abdominal organs, principally the kidneys, is responsible for the increased risk factors for and the occurrence of cardiac disease after TBI and LHB irradiation.

Invasion in follicular thyroid cancer cell lines is mediated by EphA2 and pAkt.

BACKGROUND: EphA2 is a tyrosine kinase receptor that is overexpressed in many cancers and is associated with poor prognosis and increased metastasis. Phosphorylated Akt (pAkt) plays a role in the regulation of thyroid cancer invasion and metastasis. We investigated the role of EphA2 and Akt in FTC-133 and FTC-238, 2 closely related human cell lines with differing invasive phenotypes. METHODS: Western blot was used to measure the total protein expression in cell lines, and immunohistochemistry was performed on thyroid tissue microarrays. Thyroid cell lines were transfected with siRNA or cDNA. Invasion assays were performed using Matrigel chambers, and invaded cells were assayed with (3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide (MTT). RESULTS: EphA2 protein was expressed in thyroid cancer cell lines and in benign and malignant human thyroid tumors but not in normal thyroid. Compared with FTC-133, FTC-238 expressed fivefold more EphA2 protein and had a fivefold increase in invasion (P < .001). In FTC-238, EphA2 siRNA decreased EphA2 levels and reduced invasion, with a decrease in pAkt protein. Overexpression of EphA2 in FTC-133 increased invasion and increased pAkt protein. Akt siRNA and Akt inhibitors decreased pAkt levels and invasion without changing EphA2 levels. CONCLUSION: EphA2 is expressed in human thyroid cancer and mediates invasion in the follicular thyroid cell lines FTC-133 and -238. Phosphorylated Akt (pAkt), an important regulator of thyroid cancer metastasis, is attenuated by EphA2 knockdown, providing evidence that EphA2 may act through pAkt to mediate invasion. EphA2 and pAkt may be candidates for targeted therapy against metastatic thyroid cancer.

10 Gy total body irradiation increases risk of coronary sclerosis, degeneration of heart structure and function in a rat model.

PURPOSE: To determine the impact of 10 Gy total body irradiation (TBI) or local thorax irradiation, a dose relevant to a radiological terrorist threat, on lipid and liver profile, coronary microvasculature and ventricular function. MATERIALS AND METHODS: WAG/RijCmcr rats received 10 Gy TBI followed by bone marrow transplantation, or 10 Gy local thorax irradiation. Age-matched, non-irradiated rats served as controls. The lipid profile and liver enzymes, coronary vessel morphology, nitric oxide synthase (NOS) isoforms, protease activated receptor (PAR)-1 expression and fibrinogen levels were compared. Two-dimensional strain echocardiography assessed global radial and circumferential strain on the heart. RESULTS: TBI resulted in a sustained increase in total and low density lipoprotein (LDL) cholesterol (190 +/- 8 vs. 58 +/- 6; 82 +/- 8 vs. 13 +/- 3 mg/dl, respectively). The density of small coronary arterioles was decreased by 32%. Histology revealed complete blockage of some vessels while cardiomyocytes remained normal. TBI resulted in cellular peri-arterial fibrosis whereas control hearts had symmetrical penetrating vessels with less collagen and fibroblasts. TBI resulted in a 32 +/- 4% and 28 +/- 3% decrease in endothelial NOS and inducible NOS protein, respectively, and a 21 +/- 4% and 35 +/- 5% increase in fibrinogen and PAR-1 protein respectively, after 120 days. TBI reduced radial strain (19 +/- 8 vs. 46 +/- 7%) and circumferential strain (-8 +/- 3 vs. -15 +/- 3%) compared to controls. Thorax-only irradiation produced no changes over the same time frame. CONCLUSIONS: TBI with 10 Gy, a dose relevant to radiological terrorist threats, worsened lipid profile, injured coronary microvasculature, altered endothelial physiology and myocardial mechanics. These changes were not manifest with local thorax irradiation. Non-thoracic circulating factors may be promoting radiation-induced injury to the heart.