Deep learning-based assessment of body composition and liver tumour burden for survival modelling in advanced colorectal cancer

BACKGROUND

Personalized therapy planning remains a significant challenge in advanced colorectal cancer care, despite extensive research on prognostic and predictive markers. A strong correlation of sarcopenia or overall body composition and survival has been described. Here, we explore whether automated assessment of body composition and liver metastases from standard of care CT images can add to clinical parameters in personalized survival risk prognostication.

METHODS

We retrospectively analysed clinical imaging data from 85 patients (50.6% female, mean age 58.9 SD 12.2 years) with colorectal cancer and synchronous liver metastases. Pretrained deep learning models were used to assess body composition and liver metastasis geometry from abdominal CT images before the initiation of systemic treatment. Abdominal muscle-to-bone ratio (MBR) was calculated by dividing abdominal muscle volume by abdominal bone volume. MBR was compared with body mass index (BMI), abdominal muscle volume, and abdominal muscle volume divided by height squared. Differences in overall survival based on body composition and liver metastasis parameters were compared using Kaplan-Meier survival curves. Results were correlated with clinical and biomarker data to develop a machine learning model for survival risk prognostication.

RESULTS

The MBR, unlike abdominal muscle volume or BMI, was significantly associated with overall survival (HR 0.39, 95% CI: 0.19-0.80, P = 0.009). The MBR (P = 0.022), liver metastasis surface area (P = 0.01) and primary tumour sidedness (P = 0.007) were independently associated with overall survival in multivariate analysis. Body composition parameters did not correlate with KRAS mutational status or primary tumour sidedness. A prediction model based on MBR, liver metastasis surface area and primary tumour sidedness achieved a concordance index of 0.69.

CONCLUSIONS

Automated segmentation enables to extract prognostic parameters from routine imaging data for personalized survival modelling in advanced colorectal cancer patients.

Is there a connection between immunohistochemical markers and grading of lung cancer with apparent diffusion coefficient (ADC) and standardised uptake values (SUV) of hybrid 18F-FDG-PET/MRI?

INTRODUCTION

To correlate tumour grading and prognostic immunohistochemical markers of lung cancer with simultaneously acquired standardised uptake values (SUV) and apparent diffusion coefficient (ADC) derived from hybrid PET/MRI.

METHODS

In this retrospective study, 55 consecutive patients (mean age 62.5 ± 9.2 years) with therapy-naïve, histologically proven lung cancer were included. All patients underwent whole-body PET/MRI using 18F-flourdeoxyglucose (18F-FDG) as a radiotracer. Diffusion-weighted imaging of the chest (DWI, b-values: 0, 500, 1000 s/mm² ) was performed simultaneously with PET acquisition. Histopathological tumour grading was available in 43/55 patients. In 15/55 patients, immunohistochemical markers, that is, phospho-AKT Ser473 (pAKTS473), phosphorylated extracellular signal-regulated kinase (pERK), phosphatase and tensin homolog (PTEN), and human epidermal growth factor receptor 2 (erbB2) were available.

RESULTS

The average SUVmax, SUVmean, ADCmin and ADCmean in lung cancer primaries were 12.6 ± 5.9, 7.7 ± 4.6, 569.9 ± 96.1 s/mm² and 825.8 ± 93.2 s/mm² , respectively. We found a significant inverse correlation between the ADCmin and SUVmax (r = -0.58, P < 0.001) as well as between the ADCmin and SUVmean (r = -0.44, P < 0.001). Tumour grading showed a significant positive correlation with SUVmax and SUVmean (R = 0.34 and R = 0.31, both P < 0.05) and a significant inverse correlation with ADCmin and ADCmean (r = -0.30 and r = -0.40, both P < 0.05). In addition, erbB2 showed a significant inverse correlation with SUVmax and SUVmean (r = -0.50 and r = -0.49, both P < 0.05). The other immunohistochemical markers did not show any significant correlation.

CONCLUSION

18F-FDG-PET/MRI showed weak to moderate correlations between SUV, ADC, tumour grading and erbB2-expression of lung cancer. Hence, 18F-FDG-PET/MRI may, to some extent, offer complementary information to the histopathology of lung cancer, for the evaluation of tumour aggressiveness and treatment response.

Improved survival in metastatic breast cancer: results from a 20-year study involving 1033 women treated at a single comprehensive cancer center

PURPOSE

Diagnosis and treatment of breast cancer have changed profoundly over the past 25 years. The outcome improved dramatically and was well quantified for early stage breast cancer (EBC). However, progress in the treatment of metastatic disease has been less convincingly demonstrated. We have studied survival data of patients with metastatic breast cancer (MBC) from a large academic cancer center over a period of 20 years.

METHODS

Data from 1033 consecutive MBC patients who were treated at the Department of Medical Oncology of the West German Cancer Center from January 1990 to December 2009 were retrospectively analyzed for overall survival (OS) and risk factors. Patients were grouped in 5-year cohorts, and survival parameters of each cohort were compared before and after adjustment for risk factors.

RESULTS

Overall survival of patients with MBC treated at specialized center has significantly improved from 1990 to 2010 (hazard ratio 0.7, 95%CI 0.58-0.84). The increments in OS have become less profound over time (median OS 1990-1994: 24.2 months, 1995-1999: 29.6 months, 2000-2004: 36.5 months, 2005-2009: 37.8 months).

CONCLUSION

Survival of patients with MBC has improved between 1990 and 2004, but less from 2005 to 2009. Either this suggests an unnoticed shift in the patient population, or a lesser impact of therapeutic innovations introduced in the most recent period.

Prospective comparison of 18F-FDG PET/MRI and 18F-FDG PET/CT for thoracic staging of non-small cell lung cancer

OBJECTIVES

To compare the diagnostic performance of ¹⁸F-FDG PET/MRI and ¹⁸F-FDG PET/CT for primary and locoregional lymph node staging in non-small cell lung cancer (NSCLC).

METHODS

In this prospective study, a total of 84 patients (51 men, 33 women, mean age 62.5 ± 9.1 years) with histopathologically confirmed NSCLC underwent ¹⁸F-FDG PET/CT followed by ¹⁸F-FDG PET/MRI in a single injection protocol. Two readers independently assessed T and N staging in separate sessions according to the seventh edition of the American Joint Committee on Cancer staging manual for ¹⁸F-FDG PET/CT and ¹⁸F-FDG PET/MRI, respectively. Histopathology as a reference standard was available for N staging in all 84 patients and for T staging in 39 patients. Differences in staging accuracy were assessed by McNemars chi² test. The maximum standardized uptake value (SUV_max) and longitudinal diameters of primary tumors were correlated using Pearson's coefficients.

RESULTS

T stage was categorized concordantly in ¹⁸F-FDG PET/MRI and ¹⁸F-FDG PET/CT in 38 of 39 (97.4%) patients. Herein, ¹⁸F-FDG PET/CT and ¹⁸F-FDG PET/MRI correctly determined the T stage in 92.3 and 89.7% of patients, respectively. N stage was categorized concordantly in 83 of 84 patients (98.8%). ¹⁸F-FDG PET/CT correctly determined the N stage in 78 of 84 patients (92.9%), while ¹⁸F-FDG PET/MRI correctly determined the N stage in 77 of 84 patients (91.7%). Differences between ¹⁸F-FDG PET/CT and ¹⁸F-FDG PET/MRI in T and N staging accuracy were not statistically significant (p > 0.5, each). Tumor size and SUV_max measurements derived from both imaging modalities exhibited excellent correlation (r = 0.963 and r = 0.901, respectively).

CONCLUSION

¹⁸F-FDG PET/MRI and ¹⁸F-FDG PET/CT show an equivalently high diagnostic performance for T and N staging in patients suffering from NSCLC.

MET Expression in Advanced Non-Small-Cell Lung Cancer: Effect on Clinical Outcomes of Chemotherapy, Targeted Therapy, and Immunotherapy

BACKGROUND

The receptor tyrosine kinase MET is implicated in malignant transformation, tumor progression, metastasis, and acquired treatment resistance. We conducted an analysis of the effect of MET expression and MET genomic aberrations on the outcome of patients with advanced or metastatic pulmonary adenocarcinomas prospectively enrolled in an institutional precision oncology program.

PATIENTS AND METHODS

Standardized immunohistochemistry (IHC) analyses of MET and markers of pathway activation were available in 384 patients, and next-generation sequencing-based MET hotspot mutation analyses were available from 892 patients. Clinical data were retrieved with a median follow-up from initial diagnosis of 37 months.

RESULTS

High MET expression, defined as MET IHC 3+ or MET H-Score in the upper quartile, was observed in 102 of 384 patients (26.6%). MET exon 14 mutations were only detected in 7 of 892 patients (0.78%). High MET expression correlated with activation markers of the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) pathways only in cases without Kirsten rat sarcoma viral oncogene homolog (KRAS), epidermal growth factor receptor (EGFR), v-Raf murine sarcoma viral oncogene homolog B (BRAF), anaplastic lymphoma kinase (ALK) and proto-oncogene tyrosine-protein kinase ROS (ROS1) aberrations. There was no association of MET expression with outcome during chemotherapy. High MET expression negatively affected the outcome during EGFR-targeting therapy but was associated with more favorable results with programmed death 1/programmed death ligand 1 (PD-L1)-directed therapy, independent of smoking history, PD-L1 expression or KRAS mutation. Two patients with MET exon 14 mutation and high PD-L1 expression failed to respond to pembrolizumab.

CONCLUSION

MET expression affects the outcomes of targeted therapies in non-small-cell lung cancer, thus supporting the development of biomarker-informed combination strategies. The interaction of MET expression and MET mutation with immune checkpoint inhibitor therapy is novel and merits further investigation.

Curvature estimation from a volume-of-fluid indicator function for the simulation of surface tension and wetting with a free-surface lattice Boltzmann method

The free surface lattice Boltzmann method (FSLBM) is a combination of the hydrodynamic lattice Boltzmann method with a volume-of-fluid (VOF) interface capturing technique for the simulation of incompressible free surface flows. Capillary effects are modeled by extracting the curvature of the interface from the VOF indicator function and imposing a pressure jump at the free boundary. However, obtaining accurate curvature estimates from a VOF description can introduce significant errors. This article reports numerical results for three different surface tension models in standard test cases and compares the according errors in the velocity field (spurious currents). Furthermore, the FSLBM is shown to be suited to simulate wetting effects at solid boundaries. To this end, a new method is developed to represent wetting boundary conditions in a least-squares curvature reconstruction technique. The main limitations of the current FSLBM are analyzed and are found to be caused by its simplified advection scheme. Possible improvements are suggested.

Effects of zeolite supplementation on parameters of intestinal barrier integrity, inflammation, redoxbiology and performance in aerobically trained subjects

BACKGROUND

Zeolites are crystalline compounds with microporous structures of Si-tetrahedrons. In the gut, these silicates could act as adsorbents, ion-exchangers, catalysts, detergents or anti-diarrheic agents. This study evaluated whether zeolite supplementation affects biomarkers of intestinal wall permeability and parameters of oxidation and inflammation in aerobically trained individuals, and whether it could improve their performance.

METHODS

In a randomized, double-blinded, placebo controlled trial, 52 endurance trained men and women, similar in body fat, non-smokers, 20-50 years, received 1.85 g of zeolite per day for 12 weeks. Stool samples for determination of intestinal wall integrity biomarkers were collected. From blood, markers of redox biology, inflammation, and DNA damage were determined at the beginning and the end of the study. In addition, VO2max and maximum performance were evaluated at baseline and after 12 weeks of treatment. For statistical analyses a 2-factor ANOVA was used.

RESULTS

At baseline both groups showed slightly increased stool zonulin concentrations above normal. After 12 weeks with zeolite zonulin was significantly (p < 0.05) decreased in the supplemented group. IL-10 increased tendentially (p < 0.1) in the zeolite group. There were no significant changes observed in the other measured parameters.

CONCLUSIONS

Twelve weeks of zeolite supplementation exerted beneficial effects on intestinal wall integrity as indicated via decreased concentrations of the tight junction modulator zonulin. This was accompanied by mild anti-inflammatory effects in this cohort of aerobically trained subjects. Further research is needed to explore mechanistic explanations for the observations in this study.

Expression of somatostatin receptor subtype 2 and subtype 5 in thyroid malignancies

AIM

To retrospectively analyse the expression of somatostatin receptor subtypes 2 (SSTR 2) and 5 (SSTR 5) in thyroid malignancies, possibly the most relevant subtypes for targeted therapy with somatostatin peptide radioligands. In addition, findings were also correlated with the course of disease.

PATIENTS, METHODS

87 consecutive patients (59 women, 28 men) with thyroid malignancy were included; 52 had papillary carcinoma, 24 follicular carcinoma, six medullary carcinoma, two poorly differentiated carcinoma and three anaplastic carcinoma. After initial therapy 70 (80.5%) patients showed complete remission, 11 (12.6%) patients partial remission with clinical and biochemical signs of residual disease and six (6.9%) patients progressive disease. The immunohistochemical staining results of the primary malignancy for SSTR 2 and SSTR 5 were semiquantitatively assessed and correlated with various outcome parameters.

RESULTS

In 10 of 87 (11.49%) thyroid cancer samples SSTR 2 showed positive immunohistochemical expression as compared to 75 of 87 (86.20%) for SSTR 5. All SSTR 2-positive cases expressed SSTR 5. Persistent or recurrent disease was found in 17 of 87 cases (19.54%). Fifty percent (6 /12) of SSTR 5-negative patients showed persistent disease as compared to 14.7 % (11 / 75) of SSTR 5-positive patients: seven of these were exclusively SSTR 5-positive, 4 showed dual expression of SSTR 5 and SSTR 2 (p = 0.01). No case showed only SSTR 2 expression.

CONCLUSIONS

SSTR 5 was shown to be the main receptor subtype in the analysed differentiated or anaplastic thyroid malignancies, whereas SSTR 2 was found only in a small percentage. Deficient SSTR expression may indicate higher risk for persistent or recurrent disease after initial therapy. For this reason immunohistochemistry can be considered a prognostic marker which should be further validated in prospective studies.

Immune activation in amyloid-β-related angiitis correlates with decreased parenchymal amyloid-β plaque load

BACKGROUND

Primary angiitis of the central nervous system (PACNS) is a rare but serious condition. A fraction of patients suffering from PACNS concurrently exhibit pronounced cerebral amyloid angiopathy (CAA) which is characterized by deposits of amyloid-β (Aβ) in and around the walls of small and medium-sized arteries of the brain. PACNS with CAA has been identified as a distinct disease entity, termed Aβ-related angiitis (ABRA). Evidence points to an immune reaction to vessel wall Aβ as the trigger of vasculitis.

OBJECTIVE

To investigate whether the inflammatory response to Aβ has (1) any effect on the status of immune activation in the brain parenchyma and (2) leads to clearance of Aβ from brain parenchyma.

METHODS

We studied immune activation and Aβ load by quantitative immunohistochemical analysis in brain parenchyma adjacent to affected vessels in 11 ABRA patients and 10 matched CAA controls.

RESULTS

ABRA patients showed significantly increased immune activation and decreased Aβ loads in the brain parenchyma adjacent to affected vessels.

CONCLUSION

Our results are in line with the hypothesis of ABRA being the result of an excessive immune response to Aβ and show that this can lead to enhanced clearance of Aβ from the brain parenchyma by immune-mediated mechanisms.

Probiotic supplementation affects markers of intestinal barrier, oxidation, and inflammation in trained men; a randomized, double-blinded, placebo-controlled trial

Background

Probiotics are an upcoming group of nutraceuticals claiming positive effects on athlete’s gut health, redox biology and immunity but there is lack of evidence to support these statements.

Methods

We conducted a randomized, double-blinded, placebo controlled trial to observe effects of probiotic supplementation on markers of intestinal barrier, oxidation and inflammation, at rest and after intense exercise. 23 trained men received multi-species probiotics (10¹⁰ CFU/day, Ecologic®Performance or OMNi-BiOTiC®POWER, n = 11) or placebo (n = 12) for 14 weeks and performed an intense cycle ergometry over 90 minutes at baseline and after 14 weeks. Zonulin and α1-antitrypsin were measured from feces to estimate gut leakage at baseline and at the end of treatment. Venous blood was collected at baseline and after 14 weeks, before and immediately post exercise, to determine carbonyl proteins (CP), malondialdehyde (MDA), total oxidation status of lipids (TOS), tumor necrosis factor-alpha (TNF-α), and interleukin-6 (IL-6). Statistical analysis used multifactorial analysis of variance (ANOVA). Level of significance was set at p < 0.05, a trend at p < 0.1.

Results

Zonulin decreased with supplementation from values slightly above normal into normal ranges (<30 ng/ml) and was significantly lower after 14 weeks with probiotics compared to placebo (p = 0.019). We observed no influence on α1-antitrypsin (p > 0.1). CP increased significantly from pre to post exercise in both groups at baseline and in the placebo group after 14 weeks of treatment (p = 0.006). After 14 weeks, CP concentrations were tendentially lower with probiotics (p = 0.061). TOS was slightly increased above normal in both groups, at baseline and after 14 weeks of treatment. There was no effect of supplementation or exercise on TOS. At baseline, both groups showed considerably higher TNF-α concentrations than normal. After 14 weeks TNF-α was tendentially lower in the supplemented group (p = 0.054). IL-6 increased significantly from pre to post exercise in both groups (p = 0.001), but supplementation had no effect. MDA was not influenced, neither by supplementation nor by exercise.

Conclusions

The probiotic treatment decreased Zonulin in feces, a marker indicating enhanced gut permeability. Moreover, probiotic supplementation beneficially affected TNF-α and exercise induced protein oxidation. These results demonstrate promising benefits for probiotic use in trained men.

Clinical trial registry

http://www.clinicaltrials.gov, identifier: NCT01474629

P5-11-15: Should HER-2 Score 0/1+ Breast Cancer Cases Be Retested by In-Situ Hybridisation? Results of a Multicenter Retesting Study

Background: HER-2 status is vital for selection of appropriate therapy for breast cancer patients. Accuracy of immunohistochemistry (IHC) varies with a major problem of false negative testing. To assess the false negative rate retesting by in situ hybridisation was performed on a group of primary breast cancers in which according to guidelines routine retesting is not recommended.

Material and Methods: 570 breast cancers from 5 pathology departments scored 0/1+ by IHC (HercepTest or 4B5-antibody) were retested by HER2−Dual-SISH (BDISH) in a central laboratory. CAP/ASCO guidelines were applied. Cases showing ratios in the amplified or equivocal range by BDISH were further analysed by fluorescence in situ hybridisation (FISH) using Pathvysion® and ZytoLight® and retested centrally by IHC using 4B5 antibody (Ventana).

Results: 25/570 cases (4.38%) were amplified by BDISH, the majority with low level amplification (ratios ≤ 3.26). Only two cases showed high level ratios (6.35 and 6.48). 17/570 cases (2.98%) showed ratios by BDISH in the equivocal range (1.8 — 2.2). 24 amplified and 17 equivocal cases underwent further retesting. In one case no tumor tissue was available for further testing.

On further testing 17/24 (71%) BDISH-amplified cases showed IHC scores 2+/3+ and 7/24 (29%) cases showed IHC scores 0/1+. Subsequently 3/13 score 2+ cases were amplified by Pathvysion® and 9/13 by ZytoLight®. 3/4 score 3+ cases were amplified by both FISH assays. In case of amplification ratios of BDISH and both FISH assays appeared to be in the same range. Only 2/17 BDISH-equivocal carcinomas were confirmed equivocal by Pathvysion® and 6/17 were confirmed equivocal by ZytoLight®. All other BDISH-equivocal cases were non-amplified by both FISH assays. Discrepant results between different methods could partly be caused by interobserver variability. This question is currently under investigation. Overall, after multistep retesting amplification occurred in only 17 cases (2.98%).

Discussion: Amplification is rare in immunohistochemically HER-2 negative breast carcinomas and occurred predominantly at low level in our study. Low level amplification seemed to be diagnosed more frequently by BDISH compared with FISH. Since clinical data demonstrate a benefit of therapy even in carcinomas with low level amplification the identification of these carcinomas might be of interest.

Conflicts of Interest: The study was supported by Roche Austria GmbH.

Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P5-11-15.

Intraoperative frozen section examination of the sentinel lymph node in breast cancer

AIM OF THE STUDY

Intraoperative frozen section (FS) examination of the Sentinel node (SN) in breast cancer patients is questioned due to the relatively high number of positive SN(s) found in the permanent histological examination. This study reviews the data of the Austrian sentinel node study group on FS examination of the SN and tries to identify patients with a high risk of incorrect negative results.

METHODS

2326 breast cancer patients of the Austrian Sentinel node study group who underwent SN biopsy and intraoperative FS examination of the SN were further analysed for incorrect negative results and clinicopathologic factors indicating a higher rate of incorrect negative results.

RESULTS

The FS of the SN was positive in 513 of 2326 patients (22.1%) and negative in 1813 of 2326 patients (77.9%). Permanent histological examination revealed a metastatic SN in 282 of 1813 patients. (incorrect negative rate 15.6%). 158 of 282 patients (56%) were found through H&E serial sectioning, whereas 124 of 282 patients (44%) were only seen in immunohistochemistry. Micrometastases, lobular histology and preoperative chemotherapy were associated with a higher rate of incorrect negative results.

CONCLUSION

Incorrect negative results of FS examination are seen in 15% of patients and require a secondary axillary lymph node dissection. The disadvantage of missing a positive SN through FS is by far outweighed by the advantage of a single stage operation in case of a positive SN.

Prediction of non-sentinel lymph node status in breast cancer with a micrometastatic sentinel node

Background

Axillary lymph node dissection (ALND) may not be necessary in women with breast cancer who have micrometastasis in a sentinel node (SN), owing to the low risk of non-SN (NSN) involvement. The aim of this study was to identify a subgroup of women with a micrometastatic SN and a negligible risk of positive NSNs in whom ALND may be avoided.

Methods

Some 237 of 241 women with a macrometastatic SN and 122 of 138 with a micrometastatic SN underwent completion ALND and were compared with respect to NSN involvement. The 122 patients with SN micrometastasis were further analysed to determine factors that could predict the risk of positive NSNs.

Results

A total of 121 (51·1 per cent) of 237 women with SN macrometastasis had positive NSNs compared with 22 (18·0 per cent) of 122 with SN micrometastasis (P &lt; 0·001). Multivariate analysis showed that size of SN micrometastasis (odds ratio 3·49 (95 per cent confidence interval (c.i.) 1·32 to 9·23); P = 0·012) and presence of lymphovascular invasion (odds ratio 0·23 (95 per cent c.i. 0·05 to 1·00); P = 0·050) were significantly associated with positive NSNs. SN micrometastasis less than 0·5 mm in diameter combined with absence of lymphovascular invasion was associated with an 8·5 per cent risk of NSN involvement.

Conclusion

Size of micrometastasis and presence of lymphovascular invasion were significantly related to the risk of finding additional positive axillary lymph nodes when the SN contained only micrometastasis.

[Congo red-negative light chain disease with intractable diarrhea]

A 56-year-old man was admitted due to chronic diarrhea with progressive weight loss (30 kg within 1 year). All results of medical investigations were normal. The suspected diagnosis of a neuroendocrinological neoplasm could not be established; there was also no evidence for a lymphoma or amyloidosis. Chronic diarrhea and weight loss persisted over the ensuing weeks. Additionally, impairment of renal function and heart insufficiency with consecutive pericardial effusion as well as peripheral facial paralysis and peripheral neuropathy could be observed. Six months after hospital admission, the patient died due to progressive multiple organ failure. Postmortem examination revealed normal bone marrow. Only with additional immunohistochemical investigations of all organs could the diagnosis of a systemic Congo red-negative light chain disease be established.

Closure of the cystic duct during laparoscopic cholecystectomy with a new feedback-controlled bipolar sealing system in case of biliary obstruction--an experimental study in pigs

BACKGROUND/AIMS

The excellent results of new devices like the new bipolar feedback-controlled sealing system (LigaSure) for closure of blood vessels encouraged surgeons to use these instruments for other structures like bile ducts. The aim of this study was to evaluate the feasibility of closure of cystic duct in case of biliary obstruction.

METHODOLOGY

Ten domestic pigs underwent laparoscopic cholecystectomy sealing the cystic duct with LigaSure. The common bile duct was closed with an endoclip to create a biliary hypertension. On the 12th postoperative day blood samples were taken for liver enzymes. At autopsy on day 15 the pigs were investigated for bile leaks or biliary peritonitis. The cystic duct was resected for histological examination.

RESULTS

Seven pigs survived, one pig died during introduction of anesthesia, one on the 1st and one on the 2nd postoperative day without any findings at the autopsy. One pig out of 7 had a bile leak; the other 6 were without any sign of leakage. Histologically 3 pigs had a regular coagulation zone at the cystic duct, 3 had a total necrosis, one a partial necrosis of the mucosa only.

CONCLUSIONS

Though there was only one insufficiency, the feedback-controlled bipolar vessel sealer cannot be recommended for biliary surgery with regard to the high rate of necrosis stated in our experiment.

Is there a glass transition in planar vortex systems?

The criteria for the existence of a glass transition in a planar vortex array with quenched disorder are studied. Applying a replica Bethe ansatz, we obtain for self-avoiding vortices the exact quenched average free energy and effective stiffness which is found to be in excellent agreement with recent numerical results for the related random bond dimer model [C. Zeng, P. L. Leath, and T. Hwa, Phys. Rev. Lett. 83, 4860 (1999)] Including a repulsive vortex interaction and a finite vortex persistence length xi, we find that for xi-->0 the system is at all temperatures in a glassy phase; a glass transition exists only for finite xi. Our results indicate that planar vortex arrays in superconducting films are glassy at presumably all temperatures.

Low-grade tubular-mucinous renal neoplasms: morphologic, immunohistochemical, and genetic features

The current classification system of renal tumors is based on morphologic criteria, as supported by genetic findings. We present a group of previously unclassified tumors with similar morphologic and genetic features, suggesting a new entity within renal neoplasms. Seven renal tumors from five patients (ages 31-67 years) were analyzed. All cases were stained with periodic acid-Schiff, Hale's colloidal iron (HCI), and Alcian blue (AB) at pH 2.5/1.0 with and without hyaluronidase (HA) digestion. Immunohistochemical (IHC) stains were performed for CK8, CK18, CK19, vimentin, villin, Tamm-Horsfall protein (THP), renal cell carcinoma marker (RCC), epithelial membrane antigen (EMA), ulex europaeus agglutinin (UEA-1), soy bean agglutinin (SBA), peanut agglutinin (PNA), and MIB-1. Comparative genomic hybridization (CGH) and loss of heterozygosity (LOH) studies were performed on all cases. All tumors showed circumscribed growth, a tubular growth pattern with focal solid areas, no significant nuclear atypia and absence of necrosis, desmoplasia, or inflammation. Abundant extracellular mucin was present. Immunohistochemistry stains support collecting duct origin (EMA+, PNA+, SBA+/-, CK 8/18/19+, vimentin+/-, UEA-1-, RCC-, villin-, THP-). The proliferative rate was low (<1%). CGH showed multiple consistent chromosomal losses (-1,-4, -6, -8, -9, -13, -14, -15, -22). Clinical outcome was favorable, with recurrences but no known distant metastases or death of disease. These findings are distinct from all previously classified renal neoplasms. Our data suggest the presence of a unique tumor entity within tumors of probable collecting duct origin: tubular-mucinous renal tumors of low malignant potential.

A new bipolar feedback-controlled sealing system for closure of the cystic duct and artery

BACKGROUND

Bile leaks are serious complications after laparoscopic cholecystectomy. The aim of this study was to evaluate the feasibility of closure of the cystic duct with a new feedback-controlled bipolar sealing system (LigaSure).

METHODS

Ten domestic pigs underwent open cholecystectomy with the cystic duct and artery dissected and sealed with the new bipolar sealing system (LigaSure). Four and 8 days postoperatively, 5 pigs each were sacrificed and the closure of the cystic duct was evaluated. The cystic stump and the common bile duct were excised for histological examination.

RESULTS

None of the pigs had a bile leak or a biliary peritonitis. There were no signs of postoperative bleeding or inflammation in Calot's triangle. Histology showed total necrosis of the cystic duct in the first two pigs due to too much energy used. The remaining specimens showed a regularly scaling zone without necrosis in 7 cases, and in one case a partial necrosis in the mucosa only was found.

CONCLUSION

Cystic artery and cystic duct closure with the new device may be an alternative to the clip. Further trials should evaluate the feasibility and safety of the new device in the clinical setting.

Inducible cyclooxygenase-2 gene expression in the human thyroid epithelial cell line Nthy-ori3-1

OBJECTIVE

To investigate whether the genes encoding Cyclooxygenase-1 and -2 are expressed in thyroid epithelial cells, in vitro.

MATERIALS AND METHODS

COX-1/-2 gene expression was examined in the thyroid epithelial cell line Nthy-ori3-1 using semi-quantitative RT-PCR and Western blot analysis. ELISAs were employed to assess whole cell COX-enzyme activity, PGE2 and IL-6 formation.

RESULTS

In response to IL-1beta and TNF-alpha combined cells of the thyroid epithelial cell line Nthy-ori3-1 secreted marked amounts of PGE2 in a time-dependent fashion. This is attributed to increased levels of COX-2 specific mRNA, increased amounts of COX-2 protein and COX enzyme activity in the absence of detectable COX-1 protein. The inhibition of the induced COX enzyme activity by the selective COX-2 inhibitor NS-398 demonstrated the presence of COX-2 pharmacologically. The expression of the COX-2 gene was also accompanied by a marked induction of IL-6 formation, a well described inflammatory response of thyroid epithelial cells.

CONCLUSIONS

Our observation presents first evidence that COX-2 gene expression is inducible in thyroid epithelial cells, in vitro, upon stimulation with the pro-inflammatory cytokines IL-1beta and TNF-alpha. This finding may indicate that thyroid epithelial cells could play an inflammatory controlling role perhaps during auto-immune thyroid diseases.