Kirsten Utpatel

B Cell Development Undergoes Profound Modifications and Adaptations During Pregnancy in Mice

ABSTRACT Pregnancy hides an immunological riddle combining two antagonistic characteristics of immunology: the existence of a tolerance that allows the gestation of a semiallogeneic fetus and proper protection against pathogens threatening the health of the immunocompromised mother. Despite the fundamental role that B cells play in orchestrating an immune response, their behavior in the context of pregnancy has been barely investigated. Here we demonstrate that numbers of pre/pro and immature B cells were progressively diminished in the bone marrow (BM) of pregnant mice, leading to a reduced influx of B cells in blood and spleen. Correspondingly, lower levels of B cell-activating factor of the TNF family were observed in serum of pregnant mice. In contrast to immature B cells, mature B cells were accumulated in the BM during pregnancy. Accordingly, higher numbers of mature B cells were observed in the lymph nodes draining the uterus as well as in the peritoneal cavity of pregnant mice, both tissues in close contact with the fetuses. Despite an increase in spleen size, pregnant mice showed lower numbers of splenic B cells, which was mirrored by lower numbers of immature and FO B cells. However, marginal zone B cells in the spleen increased during pregnancy. Additionally, serum IgM, IgA, and IgG3 titers were elevated in pregnant mice. Collectively, our data show how the B cell compartment adapts to the presence of the semiallogeneic fetus during gravidity.

Liver fibrosis and Gd-EOB-DTPA-enhanced MRI: A histopathologic correlation.

Gadolinium ethoxybenzyl-diethylenetriaminepentaacetic acid (Gd-EOB-DTPA) is a hepatocyte-specific MRI contrast agent. Because the hepatic uptake of Gd-EOB-DTPA depends on the integrity of the hepatocyte mass, this uptake can be quantified to assess liver function. We report the relationship between the extent of Gd-EOB-DTPA uptake and the degree of liver fibrosis. T1-weighted volume-interpolated breath-hold examination (VIBE) sequences with fat suppression were acquired before and 20 minutes after contrast injection. Strong correlations of the uptake characteristics of Gd-EOB-DTPA with the relative enhancement (RE) of the liver parenchyma and the grade of fibrosis/cirrhosis, classified using the Ishak scoring system, were observed. The subdivisions between the grades of liver fibrosis based on RE were highly significant for all combinations, and a ROC revealed sensitivities ≥82% and specificities ≥87% for all combinations. MR imaging is a satisfactorily sensitive method for the assessment of liver fibrosis/cirrhosis.

Ductoscopic Detection of Intraductal Lesions in Cases of Pathologic Nipple Discharge in Comparison with Standard Diagnostics: The German Multicenter Study

SummaryBackground: According to the literature, ductoscopy is gaining increasing importance in the diagnosis of intraductal anomalies in cases of pathologic nipple discharge. In a multicenter study, the impact of this method was assessed in comparison with that of standard diagnostics. Patients and Methods: Between 09/2006 and 05/2009, a total of 214 patients from 7 German breast centers were included. All patients underwent elective ductoscopy and subsequent ductal excision because of pathologic nipple discharge. Ductoscopy was compared with the following standard diagnostics: breast sonography, mammography, magnetic resonance imaging (MRI), galactography, cytologic nipple swab, and ductal lavage cytology. The histological and imaging results were compared and contrasted to the results obtained from the nipple swab and cytologic assessment. Results: Sonography had the highest (82.9%) sensitivity, followed by MRI (82.5%), galactography (81.3%), ductoscopy (71.2%), lavage cytology (57.8%), mammography (57.1%), and nipple swab (22.8%). Nipple swabs had the highest (85.5%) specificity, followed by lavage cytology (85.2%), ductoscopy (49.4%), galactography (44.4%), mammography (33.3%), sonography (17.9%), and MRI (11.8%). Conclusion: Currently, ductoscopy provides a direct intraoperative visualization of intraductal lesions. Sensitivity and specificity are similar to those of standard diagnostics. The technique supports selective duct excision, in contrast to the unselective technique according to Urban. Therefore, ductoscopy extends the interventional/diagnostic armamentarium.

Nipple Discharge: Role of Ductoscopy in Comparison with Standard Diagnostic Tests

Background: This study aims to assess the role of ductoscopy for detecting intraductal anomalies in patients with nipple discharge in comparison to conventional tests and to find an effective combination of both approaches. Materials and Methods: Prior to duct excision, ductoscopy was performed in 97 women. Histologic and all other diagnostic results were compared. Sensitivity, specificity, and efficiency were calculated for all methods. These parameters were also calculated for all possible test combinations in 12 patients who had completed all tests. Results: Breast sonography reached the highest sensitivity (64.1%) and efficiency (64%); mammography had the highest specificity (100%). The sensitivity of ductoscopy was 53.2%, its specificity 60%, and its efficiency 55.1%. Among combinations of all methods, the combination ductoscopy + galactography was the most sensitive (80%). Mammography, magnetic resonance imaging, and ductoscopy were each 100% specific. Ductoscopy was the most efficient (75%) single method. Conclusion: Ductoscopy is a valuable test for diagnosing intraductal lesions in patients with nipple discharge. It is more efficient than conventional tests in patients undergoing all tests.

Detecting liver fibrosis with Gd-EOB-DTPA-enhanced MRI: A confirmatory study

Strong correlations between the grade of fibrosis and cirrhosis, classified using the Ishak scoring system, and the uptake characteristics of Gd-EOB-DTPA with the relative enhancement (RE) of the liver parenchyma have been reported. To confirm the results of a retrospective analysis, patients undergoing liver surgery were prospectively examined with Gd-EOB-DTPA-enhanced liver 3 Tesla MRI to determine the degree of liver fibrosis. Correlations between the grade of fibrosis and cirrhosis, classified using the Ishak scoring system, and RE were investigated and compared with those derived from an initial retrospective study. After validating the cut-off values in the retrospective study (Ishak ≥ 1, RE-cut-off 0.90; Ishak ≥ 2, RE-cut-off 0.79; Ishak ≥ 4, RE-cut-off 0.60; and Ishak = 6, RE-cut-off 0.47), we showed that Gd-EOB-DTPA has a high sensitivity (≥86%) and a high positive predictive value (≥86%). These results support the use of Gd-EOB-DTPA-enhanced liver MRI as a non-invasive method for determining the degree of liver fibrosis and cirrhosis.

Integration of “omics” techniques: Dronedarone affects cardiac remodeling in the infarction border zone

Dronedarone improves microvascular flow during atrial fibrillation and reduces the infarct size in acute models of myocardial infarction. However, dronedarone might be harmful in patients with recent decompensated heart failure and increases mortality in patients with permanent atrial fibrillation. A pathophysiological explanation for these discrepant data is lacking. This study investigated the effects of dronedarone on gene and protein expression in the infarcted area and border zone in pigs subjected to anterior ischemia/reperfusion myocardial infarction. The ischemia/reperfusion myocardial infarction was induced in 16 pigs. Eight pigs were treated with dronedarone for 28 days after myocardial infarction, the remaining pigs served as control. Microarray-based transcriptome profiling and 2D-DIGE-based proteome analysis were used to assess the effects of dronedarone on left ventricular gene expression in healthy (LV), infarcted (MI), and border zone tissue. Selected targets were validated by RT-qPCR or immunoblot analyses, with special emphasize given to the transcriptome/proteome overlap. Combined “omics” analysis was performed to identify most significant disease and function charts affected by dronedarone and to establish an integrated network. The levels of 879 (BZ) or 7 (MI) transcripts and 51 (LV) or 15 (BZ) proteins were significantly altered by dronedarone, pointing to a substantial efficacy of dronedarone in the border zone. Transcriptome and proteome data indicate that dronedarone influences post-infarction remodeling processes and identify matricellular proteins as major targets of dronedarone in this setting. This finding is fully supported by the disease and function charts as well as by the integrated network established by combined “omics”. Dronedarone therapy alters myocardial gene expression after acute myocardial infarction with pronounced effects in the border zone. Dronedarone promotes infarct healing via regulation of periostin and might contribute to the limitation of its expansion as well as cardiac rupture. Thus, there are no experimental hints that dronedarone per se has direct harmful effects after MI in ventricular tissue. Impact statement Dronedarone reduced the infarct size in models of acute myocardial infarction (MI). Here, we show that dronedarone attenuates many of the substantial changes in gene expression that are provoked by acute myocardial infarction (AMI) in pigs. Dronedarone modifies the expression of gene panels related to post-infarction cardiac healing and remodeling processes and, most remarkably, this occurs predominantly in the infarction border-zone and much less so in the vital or infarcted myocardium. Combined “omics” identified matricellular proteins and ECM as major dronedarone-regulated targets and emphasizes their relevance for Disease Charts and Tox Function Charts associated with tissue remodeling and cellular movement. The results demonstrate dronedarone’s capability of regulating cardiac repair and remodeling processes specifically in the infarction border zone and identify underlying mechanisms and pathways that might be employed in future therapeutic strategies to improve long-term cardiac tissue function and stability.

Efficacy of MEK inhibition in a K-Ras-driven cholangiocarcinoma preclinical model

Intrahepatic cholangiocarcinoma (iCCA) is a deadly malignancy with limited treatment options. Gain-of-function mutations in K-Ras is a very frequent alteration, occurring in ~15 to 25% of human iCCA patients. Here, we established a new iCCA model by expressing activated forms of Notch1 (NICD) and K-Ras (K-RasV12D) in the mouse liver (K-Ras/NICD mice). Furthermore, we investigated the therapeutic potential of MEK inhibitors in vitro and in vivo using human CCA cell lines and K-Ras/NICD mice, respectively. Treatment with U0126, PD901, and Selumetinib MEK inhibitors triggered growth restraint in all CCA cell lines tested, with the most pronounced growth suppressive effects being observed in K-Ras mutant cells. Growth inhibition was due to reduction in proliferation and massive apoptosis. Furthermore, treatment of K-Ras/NICD tumor-bearing mice with PD901 resulted in stable disease. At the molecular level, PD901 efficiently inhibited ERK activation in K-Ras/NICD tumor cells, mainly leading to increased apoptosis. Altogether, our study demonstrates that K-Ras/NICD mice represent a novel and useful preclinical model to study K-Ras-driven iCCA development and the effectiveness of MEK inhibitors in counteracting this process. Our data support the usefulness of MEK inhibitors for the treatment of human iCCA.

Gd-EOB-DTPA-enhanced MR relaxometry for the detection and staging of liver fibrosis

Gd-EOB-DTPA, a liver-specific contrast agent with T1-shortening effects, is routinely used in clinical routine for detection and characterization of focal liver lesions and has recently received increasing attention as a tool for the quantitative analyses of liver function. We report the relationship between the extent of Gd-EOB-DTPA- induced T1 relaxation and the degree of liver fibrosis, which was assessed according to the METAVIR score. For the T1 relaxometry, a transverse 3D VIBE sequence with inline T1 calculation was acquired prior to and 20 minutes after Gd-EOB-DTPA administration. The reduction rates of the T1 relaxation time (rrT1) between the pre- and postcontrast images were calculated, and the optimal cutoff values for the fibrosis stages were determined with receiver operating characteristic (ROC) curve analyses. The rrT1 decreased with the severity of liver fibrosis and regression analysis revealed a significant correlation of the rrT1 with the stage of liver fibrosis (r = −0.906, p < 0.001). ROC analysis revealed sensitivities ≥78% and specificities ≥94% for the differentiation of different fibrosis stages. Gd-EOB-DTPA–enhanced T1 relaxometry is a reliable tool for both the detection of initial hepatic fibrosis and the staging of hepatic fibrosis.

The Epidermal Growth Factor Receptor (EGFR) Inhibitor Gefitinib Reduces but Does Not Prevent Tumorigenesis in Chemical and Hormonal Induced Hepatocarcinogenesis Rat Models

Activation of the epidermal growth factor receptor (EGFR) signaling pathway promotes the development of hepatocellular adenoma (HCA) and carcinoma (HCC). The selective EGFR inhibitor Gefitinib was found to prevent hepatocarcinogenesis in rat cirrhotic livers. Thus, Gefitinib might reduce progression of pre-neoplastic liver lesions to HCC. In short- and long-term experiments, administration of N-Nitrosomorpholine (NNM) or intrahepatic transplantation of pancreatic islets in diabetic (PTx), thyroid follicles in thyroidectomized (TTx) and ovarian fragments in ovariectomized (OTx) rats was conducted for the induction of foci of altered hepatocytes (FAH). Gefitinib was administered for two weeks (20 mg/kg) or three and nine months (10 mg/kg). In NNM-treated rats, Gefitinib administration decreased the amount of FAH when compared to controls. The amount of HCA and HCC was decreased, but development was not prevented. Upon all transplantation models, proliferative activity of FAH was lower after administration of Gefitinib in short-term experiments. Nevertheless, the burden of HCA and HCC was not changed in later stages. Thus, EGFR inhibition by Gefitinib diminishes chemical and hormonal also induced hepatocarcinogenesis in the initiation stage in the non-cirrhotic liver. However, progression to malignant hepatocellular tumors was not prevented, indicating only a limited relevance of the EGFR signaling cascade in later stages of hepatocarcinogenesis.

Dronedarone does not affect infarct volume as assessed by magnetic resonance imaging in a porcine model of myocardial infarction

Dronedarone has been demonstrated to be harmful in patients with recent decompensated heart failure. Furthermore, a PALLAS study reported that dronedarone therapy increases mortality rates in patients with permanent atrial fibrillation. Although a pathophysiological explanation for these finding remains to be elucidated, the long term effects of dronedarone on myocardial structure and stability have been suggested. The aim of the present study was to determine whether dronedarone therapy affects left ventricular (LV) function in a chronic model of myocardial infarction (MI). An anterior MI was induced in 16 pigs. Of these animals, eight pigs were then treated with dronedarone for 1 week prior to, and 4 weeks following MI, the remaining pigs served as controls. LV angiography was performed 4 weeks after MI to determine the LV ejection fraction (LVEF). A post‑mortem magnetic resonance imaging scan of the LV was then performed on the two groups (n=6) to determine the volume and size of the induced MI. Dronedarone therapy did not affect systemic and intracardiac hemodynamic parameters or LVEF during the follow‑up assessment. Of note, dronedarone had no negative effect on the total infarct volume and size and did not induce lethal proarrhythmic effects following the induced anterior MI. Therefore, the results suggested that dronedarone did not increase the volume or size of induced anterior MI and did not affect LV performance. Thus, dronedarone therapy was observed to be safe in a porcine model of anterior MI.