Thermal stability of hierarchical microstructural features in additively manufactured stainless steel.

Additive manufacturing of austenitic stainless steel results in an unconventional hierarchical microstructure. This hierarchical microstructure was investigated in detail in the as-built condition. The hierarchical microstructure consists of elongated austenite grains and melt pool fusion boundaries with a spherical cap morphology at the largest length scale. At a smaller length scale elongated columnar cell structures exist with elemental segregation at the cell walls. The cells were found not to be a misorientation structure in themselves as often noted, but rather groups of cells with a specific orientation, which are collected in 3-5 µm domains. At even smaller length scales, amorphous spherical silicates are found along with a high dislocation density along cell walls. The thermal stability of the unconventional features as melt pool boundaries, elongated austenite grains, cell domains, cell structure, amorphous precipitates was investigated systematically in the temperature range 400-1100 °C. The dislocation network forming the cell boundaries dissolves gradually and remains thermally stable up to about 800 °C. The melt pool boundaries are more thermally stable and dissolve above 900 °C. The elongated austenite grains and crystallographic texture are fully stable within the investigated temperature range. The cell domains appear to be pinned by precipitation as the cellular structure is dissolved and gradually straighten and resemble regular low angle grain boundaries. The amorphous silicates act as heterogeneous nucleation sites for the formation of σ-phase in the temperature range 700-800 °C, while at higher treatment temperatures these silicates are replaced by large, oblong Si-Mn oxides and small, round Mn-Cr oxides.

Diagnostic accuracy of ultrasound-guided core biopsy of peripheral nerve sheath tumors.

PURPOSE: To retrospectively evaluate the diagnostic accuracy of and complications from ultrasound-guided core needle biopsy (UGCNB) of suspected peripheral nerve sheath tumors (PNSTs). METHODS: Patients undergoing UGCNB from January 2004 to December 2016, based on the suspicion of PNST, were included in the study. Age, gender, anatomical location, dates of relevant events, and histopathological reports of the UGCNB cores and the resected tumors were retrieved from the patients' medical records. RESULTS: A total of 154 UGCNBs were identified. One hundred and forty (90.9%) of these resulted in a conclusive histopathological report, while 14 were unsuited for histopathological analysis due to insufficient amount of tissue and/or nonrepresentative tissue. The overall diagnostic accuracy of UGCNB with respect to discriminate malignant from benign tumors was 99.3%, while correct specific UGCNB diagnoses were confirmed in 95.1% of the cases. Sensitivity and specificity were 90.9% (95% CI: 58.7-99.8%) and 100% (95% CI: 97.2-100%), respectively. The positive predictive value was 100%, and the negative predictive value was 99.2%. Except for one patient, who reported mild dysesthesia, which resolved 2 days after the UGCNB, no complications were reported. CONCLUSION: This study suggests that UGCNB is accurate and safe in patients suspected for PNST.

Electrified methane reforming: A compact approach to greener industrial hydrogen production.

Electrification of conventionally fired chemical reactors has the potential to reduce CO2 emissions and provide flexible and compact heat generation. Here, we describe a disruptive approach to a fundamental process by integrating an electrically heated catalytic structure directly into a steam-methane-reforming (SMR) reactor for hydrogen production. Intimate contact between the electric heat source and the reaction site drives the reaction close to thermal equilibrium, increases catalyst utilization, and limits unwanted byproduct formation. The integrated design with small characteristic length scales allows compact reactor designs, potentially 100 times smaller than current reformer platforms. Electrification of SMR offers a strong platform for new reactor design, scale, and implementation opportunities. Implemented on a global scale, this could correspond to a reduction of nearly 1% of all CO2 emissions.

Co-Detection of miR-21 and TNF-α mRNA in Budding Cancer Cells in Colorectal Cancer.

MicroRNA-21 (miR-21) is upregulated in many cancers including colon cancers and is a prognostic indicator of recurrence and poor prognosis. In colon cancers, miR-21 is highly expressed in stromal fibroblastic cells and more weakly in a subset of cancer cells, particularly budding cancer cells. Exploration of the expression of inflammatory markers in colon cancers revealed tumor necrosis factor alpha (TNF-α) mRNA expression at the invasive front of colon cancers. Surprisingly, a majority of the TNF-α mRNA expressing cells were found to be cancer cells and not inflammatory cells. Because miR-21 is positively involved in cell survival and TNF-α promotes necrosis, we found it interesting to analyze the presence of miR-21 in areas of TNF-α mRNA expression at the invasive front of colon cancers. For this purpose, we developed an automated procedure for the co-staining of miR-21, TNF-α mRNA and the cancer cell marker cytokeratin based on analysis of frozen colon cancer tissue samples (n = 4) with evident cancer cell budding. In all four cases, TNF-α mRNA was seen in a small subset of cancer cells at the invasive front. Evaluation of miR-21 and TNF-α mRNA expression was performed on digital slides obtained by confocal slide scanning microscopy. Both co-expression and lack of co-expression with miR-21 in the budding cancer cells was noted, suggesting non-correlated expression. miR-21 was more often seen in cancer cells than TNF-α mRNA. In conclusion, we report that miR-21 is not linked to expression of the pro-inflammatory cytokine TNF-α mRNA, but that miR-21 and TNF-α both take part in the cancer expansion at the invasive front of colon cancers. We hypothesize that miR-21 may protect both fibroblasts and cancer cells from cell death directed by TNF-α paracrine and autocrine activity.

Programmed Death Ligand-1 expression in stage II colon cancer - experiences from a nationwide populationbased cohort.

BACKGROUND: Patients suffering from high risk stage II colon cancer (CC) may benefit from adjuvant onco-therapy, but additional prognostic markers are needed for better treatment stratification. We investigated the prognostic value of Programmed Death Ligand-1 (PD-L1) in a true population-based cohort of patients with stage II CC. METHODS: PD-L1 expression on tumour cells was evaluated by immunohistochemistry in 572 colon cancers. Whole sections from tumour blocks representing the deepest invasive front of the primary tumour were used for analysis. A cut-off of 5% positivity was used for dichotomizing the data. The prognostic value was investigated in Cox proportional hazard models for recurrence-free survival (RFS) and overall survival (OS). RESULTS: Overall, 6% of the tumours were classified as high PD-L1. High PD-L1 was related to female gender (p = 0.028), high malignancy grade (< 0.001), right side localization (p < 0.001) and microsatellite instability (MSI) (p < 0.001). Thirty-one (18%) of the MSI and 4 (1%) of the microsatellite stable tumours were classified as high PD-L1, respectively. PD-L1 expression provided no prognostic value as a single marker. In patients with MSI tumours, high PD-L1 expression had no significant impact regarding OS or RFS. CONCLUSIONS: PD-L1 expression in tumour cells of stage II CC did not provide any prognostic impact, neither in the entire population-based cohort nor in the group of MSI patients. Additional investigations of the immunogenic microenvironment are needed for evaluating the prognostic information in CC.

The Prognostic Value of Tumor-Infiltrating lymphocytes in Stage II Colon Cancer. A Nationwide Population-Based Study.

BACKGROUND: Additional prognostic markers are needed for better treatment stratification of stage II colon cancer (CC). We investigated the prognostic value of tumor-infiltrating lymphocytes (TILs) in a true population-based cohort of patients with stage II CC. MATERIAL AND METHODS: A total of 573 patients were included. Tumor blocks representing the deepest invasive part of the primary tumor were used for analysis. CD3+ and CD8+ TILs at the invasive front were evaluated by immunohistochemistry on whole tumor sections. The invasive area was manually outlined, and Visiopharm Integrator System software was used for quantification. Data were dichotomized for comparison with clinical data. The prognostic value was investigated in Cox proportional-hazard models for recurrence-free survival (RFS) and overall survival (OS). RESULTS: Low CD3+ or CD8+ TILs were significantly associated with poor RFS and OS (P = .0021 and P ≤ .0009, respectively, log-rank test). In multiple Cox regression analysis, low CD3+ and CD8+ TILs were associated with reduced RFS with hazard ratio (HR) = 1.386 (95% CI 1.039-1.850), P = .026, and HR = 1.394 (95% CI 1.029-1.890), P = .032, respectively, independent of age, T-stage, localization, perforation, and microsatellite instability (MSI). In the subgroups of patients with low CD3+ or CD8+ TILs, there was no difference in survival between patients with MSI and microsatellite-stable tumors, (P = .821 and P = .907, respectively). CONCLUSION: Low CD3+ and CD8+ TILs in the invasive area are both related to inferior prognosis of stage II CC, and we recommend either of these parameters to be considered as additional high-risk factor.

The prognostic value of tumour stroma ratio and tumour budding in stage II colon cancer. A nationwide population-based study.

PURPOSE: High-risk patients with stage II colon cancer (CC) may benefit from adjuvant chemotherapy, but additional prognostic markers are needed for better stratification. We investigated the prognostic value of tumour stroma ratio (TSR) and tumour budding (TB). METHODS: A nationwide population-based cohort of 573 patients with stage II CC was included. TSR was scored on hematoxylin and eosin sections as low TSR (> 50% stroma) and high TSR (≤ 50% stroma). TB was evaluated in hotspots on pan-cytokeratin stained sections in 10 high power fields (HPF) at the invasive front and classified by the mean number of buds per HPF as high grade budding (≥ 10 buds) or low-grade budding (< 10 buds). The prognostic value was investigated in Cox proportional hazard models for recurrence-free survival (RFS) and overall survival (OS). RESULTS: Low TSR was associated with worse RFS (HR = 1.342 (95% CI 1.006-1.791), p = 0.045) and OS (HR = 1.376 (95% CI 1.016-1.862), p = 0.039). Furthermore, an association was found between low TSR and microsatellite stabile tumours (p < 0.001). The mean number of buds per HPF was associated to TSR with increasing number of buds related to a lower TSR (p = 0.026). No statistically significant prognostic impact of TB regarding OS or RFS was detected. CONCLUSIONS: TSR provided valuable prognostic information, and adding TSR to the current risk stratification may contribute to better patient selection. The estimates of TSR and TB were found to be associated, but no prognostic value of TB was documented.

Does heterogeneity matter in the estimation of tumour budding and tumour stroma ratio in colon cancer?

BACKGROUND: Tumour budding (TB) and Tumour Stroma Ratio (TSR) may be rewarding in the treatment stratification of patients with stage II colon cancer. However, lack of standardization may exclude these parameters from being used in a clinical setting. The purpose of this methodologic study was to compare stereology with semi-quantitative estimations of TSR, to investigate the intra-tumoural heterogeneity of TB and TSR, and to assess the intra- and inter-observer agreement. METHODS: Three paraffin embedded tumour blocks, one of them representing the deepest invasive front, were selected from each of 43 patients treated for stage II colon cancer. TSR was estimated in H&E sections semi-quantitatively using conventional microscopy, and stereologically on scanned slides, using the newCAST stereology platform. TB was scored across 10 high power fields at the invasive front in cytokeratin AE1/AE3 stained sections. RESULTS: Subjective, semi-quantitative estimates of TSR significantly correlated to the stereological estimates, with the best correlation found for sections with the deepest invasive tumour penetration (σ = 0.621, p < 0.001). Inter-observer agreement was moderate to substantial for both TB (Κappa = 0.46-0.73) and TSR (Κappa = 0.70-0.75). The Intraclass correlation coefficient (ICC) for TSR varied from 0.322 based on stereological hotspot estimation to 0.648 for the semi-quantitative evaluation. For TB, ICC varied from 0.646 based on continuous data to 0.698 based on categorical data (cut-off: 10 buds). Thus, the intra-tumoural heterogeneity for both TB and the semi-quantitative estimation of TSR was low. CONCLUSION: We recommend using only one tissue section representing the deepest invasive tumour area for estimation of TSR. For TB we recommend using one tissue section; however due to low representation of high-budding tumours, results must be considered with caution.

Influence of intra-tumoral heterogeneity on the evaluation of BCL2, E-cadherin, EGFR, EMMPRIN, and Ki-67 expression in tissue microarrays from breast cancer.

INTRODUCTION: The influence of intra-tumoral heterogeneity on the evaluation of immunohistochemical (IHC) biomarker expression may affect the analytical validity of new biomarkers substantially and hence compromise the clinical utility. The aim of this study was to examine the influence of intra-tumoral heterogeneity as well as inter-observer variability on the evaluation of various IHC markers with potential prognostic impact in breast cancer (BCL2, E-cadherin, EGFR, EMMPRIN and Ki-67). MATERIAL AND METHODS: From each of 27 breast cancer patients, two tumor-containing paraffin blocks were chosen. Intra-tumoral heterogeneity was evaluated (1) within a single tumor-containing paraffin block ('intra-block agreement') by comparing information from a central, a peripheral tissue microarray (TMA) core and a whole slide section (WS), (2) between two different tumor-containing blocks from the same primary tumor ('inter-block agreement') by comparing information from TMA cores (central/peripheral) and WS. IHC markers on WS and TMA cores were evaluated by two observers independently, and agreements were estimated by Kappa statistics. RESULTS: For BCL2, E-cadherin and EGFR, an almost perfect intra- and inter-block agreement was found. EMMPRIN and Ki-67 showed a more heterogeneous expression with moderate to substantial intra-block agreements. For both stainings, there was a moderate inter-block agreement that improved slightly for EMMPRIN, when using WS instead of TMA cores. Inter-observer agreements were found to be almost perfect for BCL2, E-cadherin and EGFR (WS: κ > 0.82, TMAs: κ > 0.90), substantial for EMMPRIN (κ > 0.63), but only fair to moderate for Ki-67 (WS: κ = 0.54, TMAs: κ = 0.33). CONCLUSIONS: BCL2, E-cadherin and EGFR were found to be homogeneously expressed, whereas EMMPRIN and Ki-67 showed a more pronounced degree of intra-tumoral heterogeneity. The results emphasize the importance of securing the analytical validity of new biomarkers by examining the intra-tumoral heterogeneity of immunohistochemical stainings applied to TMA cores individually in each type of cancer.

Computer-assisted stereology and automated image analysis for quantification of tumor infiltrating lymphocytes in colon cancer.

BACKGROUND: Precise prognostic and predictive variables allowing improved post-operative treatment stratification are missing in patients treated for stage II colon cancer (CC). Investigation of tumor infiltrating lymphocytes (TILs) may be rewarding, but the lack of a standardized analytic technique is a major concern. Manual stereological counting is considered the gold standard, but digital pathology with image analysis is preferred due to time efficiency. The purpose of this study was to compare manual stereological estimates of TILs with automatic counts obtained by image analysis, and at the same time investigate the heterogeneity of TILs. METHODS: From 43 patients treated for stage II CC in 2002 three paraffin embedded, tumor containing tissue blocks were selected one of them representing the deepest invasive tumor front. Serial sections from each of the 129 blocks were immunohistochemically stained for CD3 and CD8, and the slides were scanned. Stereological estimates of the numerical density and area fraction of TILs were obtained using the computer-assisted newCAST stereology system. For the image analysis approach an app-based algorithm was developed using Visiopharm Integrator System software. For both methods the tumor areas of interest (invasive front and central area) were manually delineated by the observer. RESULTS: Based on all sections, the Spearman's correlation coefficients for density estimates varied from 0.9457 to 0.9638 (p < 0.0001), whereas the coefficients for area fraction estimates ranged from 0.9400 to 0.9603 (P < 0.0001). Regarding heterogeneity, intra-class correlation coefficients (ICC) for CD3+ TILs varied from 0.615 to 0.746 in the central area, and from 0.686 to 0.746 in the invasive area. ICC for CD8+ TILs varied from 0.724 to 0.775 in the central area, and from 0.746 to 0.765 in the invasive area. CONCLUSIONS: Exact objective and time efficient estimates of numerical densities and area fractions of CD3+ and CD8+ TILs in stage II colon cancer can be obtained by image analysis and are highly correlated to the corresponding estimates obtained by the gold standard based on stereology. Since the intra-tumoral heterogeneity was low, this method may be recommended for quantifying TILs in only one histological section representing the deepest invasive tumor front.

Prehospital intravenous fentanyl to patients with hip fracture: an observational cohort study of risk factors for analgesic non-treatment.

BACKGROUND: Patients with proximal femoral neck fracture have a high short-term mortality, a high risk of postoperative complications, and impaired quality of life. One of the challenges related to the prehospital treatment of these patients is to administer systemic opioids fast and properly. Effective analgesic prehospital treatment ought be initiated rapidly in order to alleviate the stress that follows acute pain, to facilitate transportation, and to improve quality of care. The objectives of this study were to explore the prevalence of prehospital administration of intravenous fentanyl to patients with proximal femoral neck fracture in the ambulances and to assess risk factors for analgesic non-treatment. METHODS: This was a register-based observational cohort study of patients with proximal femoral neck fracture from the North Denmark Region transported by ambulance. The patients were identified via the Danish Interdisciplinary Hip Fracture Registry over a 3-year period from 1 July 2011 to 30 June 2014. This hospital registry contains data on several patient characteristics used for the risk factor analysis. Data on prehospital treatment (intravenous fentanyl) and patient monitoring were registered in an electronic prehospital patient record. A modified Poisson regression with robust standard errors was carried out with intravenous fentanyl as the primary binary outcome and the following explanatory variables: age, sex, Charlson Comorbidity Index score, housing, body mass index, type of fracture, fracture displacement, prior consultation with general practitioner, dispatch triage level, and time with ambulance personnel. RESULTS: In total, 2,140 patients with proximal femoral neck fracture were transported by ambulance, of which 584 (27.3%, 95% CI: 25.4-29.2) were treated with intravenous fentanyl. Risk factors for non-treatment were: older age, male sex (RR 0.77, 95% CI: 0.64-0.91), institutional housing (RR 0.72, 95% CI: 0.56-0.92), medial fracture (RR 0.74, 95% CI: 0.60-0.92), short time with ambulance personnel, Charlson Comorbidity Index score > 1, year of fracture (2011), low levels of urgency at dispatch, and if seen by general practitioners prior to transport. DISCUSSION: Education of ambulance personnel in assessing and treating patients with hip fracture seems to be required. Also, future studies should consider alternative or supportive pain treatment options with suitable analgesic effects and side effects. CONCLUSIONS: Few patients with proximal femoral neck fracture were treated with intravenous fentanyl, and several risk factors were associated with prehospital analgesic non-treatment. Future prospective studies should explore covariates of socioeconomic, cultural, and psychological origin to provide further insight into the multifactorial causes of non-treatment of acute pain.

On the formation of current ripples.

For grain sizes finer than coarse sand, the first flow-transverse bedforms to develop are current ripples. Although numerous studies have analysed different aspects of bedform morphodynamics, to date no comprehensive physical explanation for the formation of ripples has been given. We offer such an explanation based on a virtual boundary layer concept, and present a model predicting ripple height on the basis of grain size, current velocity and water depth. The model contradicts the conventional view of current ripples as bedforms not scaling with flow depth. Furthermore, it confirms the dependence of ripple dimensions on grain size, and their relative insensitivity to flow strength.

How bold is blood oxygenation level-dependent (BOLD) magnetic resonance imaging of the kidney? Opportunities, challenges and future directions.

Renal tissue hypoperfusion and hypoxia are key elements in the pathophysiology of acute kidney injury and its progression to chronic kidney disease. Yet, in vivo assessment of renal haemodynamics and tissue oxygenation remains a challenge. Many of the established approaches are invasive, hence not applicable in humans. Blood oxygenation level-dependent (BOLD) magnetic resonance imaging (MRI) offers an alternative. BOLD-MRI is non-invasive and indicative of renal tissue oxygenation. Nonetheless, recent (pre-) clinical studies revived the question as to how bold renal BOLD-MRI really is. This review aimed to deliver some answers. It is designed to inspire the renal physiology, nephrology and imaging communities to foster explorations into the assessment of renal oxygenation and haemodynamics by exploiting the powers of MRI. For this purpose, the specifics of renal oxygenation and perfusion are outlined. The fundamentals of BOLD-MRI are summarized. The link between tissue oxygenation and the oxygenation-sensitive MR biomarker T2∗ is outlined. The merits and limitations of renal BOLD-MRI in animal and human studies are surveyed together with their clinical implications. Explorations into detailing the relation between renal T2∗ and renal tissue partial pressure of oxygen (pO2 ) are discussed with a focus on factors confounding the T2∗ vs. tissue pO2 relation. Multi-modality in vivo approaches suitable for detailing the role of the confounding factors that govern T2∗ are considered. A schematic approach describing the link between renal perfusion, oxygenation, tissue compartments and renal T2∗ is proposed. Future directions of MRI assessment of renal oxygenation and perfusion are explored.

Early effects of an x-ray contrast medium on renal T(2) */T(2) MRI as compared to short-term hyperoxia, hypoxia and aortic occlusion in rats.

AIM: X-ray contrast media (CM) can cause acute kidney injury (AKI). Medullary hypoxia is pivotal in CM-induced AKI, as indicated by invasively and pin-point measured tissue oxygenation. MRI provides spatially resolved blood oxygenation level-dependent data using T2 * and T2 mapping. We studied CM effects on renal T2 */T2 and benchmarked them against short periods of hyperoxia, hypoxia and aortic occlusion (AO). METHODS: Rats were equipped with carotid artery catheters (tip towards aorta) and supra-renal aortic occluders. T2 */T2 mapping was performed using a 9.4-T animal scanner. CM (1.5 mL iodixanol) was injected into the thoracic aorta with the animal in the scanner followed by 2 h of T2 */T2 mapping. For T2 */T2 assessment, regions of interest in the cortex (C), outer medulla (OM), inner medulla (IM) and papilla (P) were determined according to morphological features. RESULTS: Hyperoxia increased T2 * in C (by 17%) and all medullary layers (25-35%). Hypoxia decreased T2 * in C (40%) and all medullary layers (55-60%). AO decreased T2 * in C (18%) and all medullary layers (30-40%). Upon injection of CM, T2 * increased transiently, then decreased, reaching values 10-20% below baseline in C and OM and 30-40% below baseline in IM and P. CONCLUSION: T2 * mapping corroborates data previously obtained with invasive methods and demonstrates that CM injection affects renal medullary oxygenation. CM-induced T2 * decrease in OM was small vs. hypoxia and aortic occlusion. T2 * decrease obtained for hypoxia was more pronounced than for AO. This indicates that T2 * may not accurately reflect blood oxygenation under certain conditions.

Multiple functional polymorphisms in the G6PC2 gene contribute to the association with higher fasting plasma glucose levels.

AIMS/HYPOTHESIS: We previously identified the G6PC2 locus as a strong determinant of fasting plasma glucose (FPG) and showed that a common G6PC2 intronic single nucleotide polymorphism (SNP) (rs560887) and two common G6PC2 promoter SNPs (rs573225 and rs13431652) are highly associated with FPG. However, these promoter SNPs have complex effects on G6PC2 fusion gene expression, and our data suggested that only rs13431652 is a potentially causative SNP. Here we examine the effect of rs560887 on G6PC2 pre-mRNA splicing and the contribution of an additional common G6PC2 promoter SNP, rs2232316, to the association signal. METHODS: Minigene analyses were used to characterise the effect of rs560887 on G6PC2 pre-mRNA splicing. Fusion gene and gel retardation analyses characterised the effect of rs2232316 on G6PC2 promoter activity and transcription factor binding. The genetic association of rs2232316 with FPG variation was assessed using regression adjusted for age, sex and BMI in 4,220 Europeans with normal FPG. RESULTS: The rs560887-G allele was shown to enhance G6PC2 pre-mRNA splicing, whereas the rs2232316-A allele enhanced G6PC2 transcription by promoting Foxa2 binding. Genetic analyses provide evidence for association of the rs2232316-A allele with increased FPG (ß = 0.04 mmol/l; p = 4.3 × 10(-3)) as part of the same signal as rs560887, rs573225 and rs13431652. CONCLUSIONS/INTERPRETATION: As with rs13431652, the in situ functional data with rs560887 and rs2232316 are in accord with the putative function of G6PC2 in pancreatic islets, and suggest that all three are potentially causative SNPs that contribute to the association between G6PC2 and FPG.

Linking non-invasive parametric MRI with invasive physiological measurements (MR-PHYSIOL): towards a hybrid and integrated approach for investigation of acute kidney injury in rats.

Acute kidney injury of various origins shares a common link in the pathophysiological chain of events: imbalance between renal medullary oxygen delivery and oxygen demand. For in vivo assessment of kidney haemodynamics and oxygenation in animals, quantitative but invasive physiological methods are established. A very limited number of studies attempted to link these invasive methods with parametric Magnetic Resonance Imaging (MRI) of the kidney. Moreover, the validity of parametric MRI (pMRI) as a surrogate marker for renal tissue perfusion and renal oxygenation has not been systematically examined yet. For this reason, we set out to combine invasive techniques and non-invasive MRI in an integrated hybrid setup (MR-PHYSIOL) with the ultimate goal to calibrate, monitor and interpret parametric MR and physiological parameters by means of standardized interventions. Here we present a first report on the current status of this multi-modality approach. For this purpose, we first highlight key characteristics of renal perfusion and oxygenation. Second, concepts for in vivo characterization of renal perfusion and oxygenation are surveyed together with the capabilities of MRI for probing blood oxygenation-dependent tissue stages. Practical concerns evoked by the use of strong magnetic fields in MRI and interferences between MRI and invasive physiological probes are discussed. Technical solutions that balance the needs of in vivo physiological measurements together with the constraints dictated by small bore MR scanners are presented. An early implementation of the integrated MR-PHYSIOL approach is demonstrated including brief interventions of hypoxia and hyperoxia.

Histiocytic disorders of the gastrointestinal tract.

The morphologic diagnosis of histiocytic lesions of the gastrointestinal tract can be challenging, and several disorders have to be considered in their differential diagnosis. We present one of the most widespread examples of xanthomatosis of the gastrointestinal tract published so far and give a short review on histiocytic disorders of the gastrointestinal tract in general. The primary histiocytic disorders of uncertain origin, Rosai-Dorfman disease, Langerhans cell histiocytosis, and Erdheim-Chester disease, are addressed. Reactive and infectious conditions such as xanthomatosis, xanthogranulomatous inflammation, juvenile xanthogranuloma, Whipple's disease and malacoplakia are discussed as well. We also briefly go into primary histiocytic disorders of neoplastic origin, systemic diseases with secondary gastrointestinal tract involvement like the lysosomal storage disorders, and pigmented lesions. Using a panel of histochemical stains and immunohistochemical markers, together with conventional microscopy, clinical information, and imaging studies, the diagnosis of histiocytic disorders of the gastrointestinal tract can be established in most instances.

The influence of tissue ischemia on biomarker expression in colorectal cancer.

The aim of the present study was to investigate the influence of fixation delay and the perioperative ischemia on hypoxia inducible factor (HIF)-1α gene expression, HIF-1α protein expression, and immunohistochemical (IHC) expression of HIF-1α, GLUT-1, Bcl-2, and Ki-67 in colorectal cancer. The study included 25 surgically removed colorectal tumors. Three sets of samples were collected readily after removal and exposed to 0, 30, and 60 minutes of delay of fixation or freezing. The perioperative ischemia time was registered. In each set of the samples, HIF-1α gene expression was analyzed by quantitative real time polymerase chain reaction, protein concentration of HIF-1α was assessed by enzyme-linked immunosorbent assay, and IHC staining of HIF-1α, GLUT-1, Bcl-2, and Ki-67 was performed. Preoperative formalin-fixed paraffin-embedded biopsies and whole sections of the entire tumor were analyzed by IHC. We found that the HIF-1α gene expression, HIF-1α protein concentration, and IHC expression of HIF-1α, GLUT-1, Ki-67, and Bcl-2 were not systematically affected by either the fixation or freezing delay of the tissue, the perioperative ischemia time, or the total ischemia time (perioperative ischemia+delay of fixation or freezing) in colorectal tumors. However, the intraindividual variation was quite large, which may question the use of individually, non-standardized-handled single biopsies or small tissue samples for analysis of often rather heterogenously expressed biomarkers.

Estimation of immunohistochemical expression of VEGF in ductal carcinomas of the breast.

Vascular endothelial growth factor A (VEGF-A) is a very important growth factor in angiogenesis and holds potential as both a predictive marker for anti-angiogenic cancer treatment and a prognostic variable. Consequently, reliable estimation of VEGF expression is crucial. Investigators immunostained whole tumor sections for VEGF-A, VEGF-B, and VEGFR-1 of invasive ductal carcinomas of the breast and scored the tumors manually with staining intensity as the only parameter and by a combination of qualitative and quantitative information. The investigators also introduce an automated method for analyzing VEGF expression (so-called AI score) using the same tumor sections. Analysis of 100% of the tumor area was performed and the results were compared with the reduced analysis of 25% of the tumor area. These analyses were performed at ×5 and ×10 magnification, and each analysis was repeated in a second run with a new delineation of the tumor area. The AI scores were correlated to the manual scoring of VEGF intensity, but reproducibility of manual IHC scores was rather poor. The AI scores were reproducible, and the restricted analysis of 25% of the tumor area at ×5 magnifications was the most efficient considering time consumption and data load.

Expression level, tissue distribution pattern, and prognostic impact of vascular endothelial growth factors VEGF and VEGF-C and their receptors Flt-1, KDR, and Flt-4 in different subtypes of non-Hodgkin lymphomas.

The aim of the study was to investigate the expression of angio- and lymphangiogenic molecules (vascular endothelial growth factors VEGF and VEGF-C and their receptors Flt-1, KDR, and Flt-4) in non-Hodgkin lymphomas (NHL) treated in the pre-rituximab era. Pre-therapeutic lymph-node biopsies from 155 patients with NHL (64 follicular lymphomas (FLs), 47 de novo diffuse large B-cell lymphomas (DLBCL) and 44 peripheral T-cell lymphomas (PTCL)) were stained by in situ hybridization and immunohistochemistry. Tumor cell expression of VEGF, VEGF-C and their receptors was detected in most of the analyzed biopsies. In FL, diffuse intratumoral VEGF staining correlated with shorter overall survival (OS) (p = 0.008) and diffuse KDR staining was associated with a higher risk of histologic transformation (p = 0.05). In DLBCL, high KDR expression predicted poor treatment response (p = 0.03) and had a significant adverse impact on OS (p < 0.001). In PTCL, diffuse tissue distribution of VEGF mRNA correlated with an unfavorable 5-year OS (p = 0.004).