[Radiological embolization procedures in acute gastrointestinal, peritoneal and muscular hemorrhage]. / Radiologische Embolisationsverfahren akuter gastrointestinaler, peritonealer und muskulärer Blutungen.

BACKGROUND: Treatment of acute hemorrhage is particularly challenging due to its sudden onset and the fact that it is often life-threatening. Potential causes include bleeding ulcerations of the gastrointestinal tract or tumor bleeding, but acute bleeding can also occur spontaneously or be traumatic, iatrogenic, or inflammatory. OBJECTIVE: To demonstrate the basic principles of catheter embolization, as well as various embolic materials and their properties. RESULTS: Today there are a wide range of embolization materials available. Ultimately the duration and extent of the desired occlusion are decisive when selecting an embolic material. Mechanical occlusion devices, particulates, and liquid embolic agents are available. CONCLUSION: Irrespective of the wide range of different etiologies, radiological embolization therapy is a very safe treatment option in cases of computed tomographic evidence of active hemorrhage. Ultimately, the interventionalist's comprehensive knowledge of the relevant characteristics is crucial for the success of therapy.

MR lymphangiography of lymphatic abnormalities in children and adults with Noonan syndrome.

Noonan syndrome is associated with complex lymphatic abnormalities. We report dynamic-contrast enhanced MR lymphangiography (DCMRL) findings in children and adults with Noonan syndrome to further elucidate this complex disease spectrum. A retrospective evaluation of patients with confirmed Noonan syndrome and clinical signs of lymphatic dysfunction undergoing DCMRL between 01/2019 and 04/2021 was performed. MRL included T2-weighted imaging (T2w) and DCMRL. Clinical history/presentation and genetic variants were recorded. T2w-imaging was evaluated for central lymphatic abnormalities and edema distribution. DCMRL was evaluated regarding the presence of cisterna chyli/thoracic duct, lymphatic leakages, pathological lymphatic reflux and abnormal lymphatic perfusion. The time from start of contrast-injection to initial enhancement of the thoracic duct venous junction was measured to calculate the speed of contrast propagation. Eleven patients with Noonan syndrome with lymphatic abnormalities (5 female, 6 male; 7 infants, 4 adults; mean age 10.8 ± 16.4 years) were identified (PTPN11 n = 5/11 [45.5%], RIT1 n = 5/11 [45.5%], KRAS n = 1/11 [9%]). Patients had a chylothorax (n = 10/11 [91%]) and/or pulmonary lymphangiectasia [dilated pulmonary lymph vessels] (n = 9/11 [82%]). Mediastinal/pulmonary edema was depicted in 9/11 (82%) patients. The thoracic duct (TD) was (partially) absent in 10/11 (91%) cases. DCMRL showed lymphatic reflux into intercostal (n = 11/11 [100%]), mediastinal (n = 9/11 [82%]), peribronchial (n = 8/11 [73%]), peripheral (n = 5/11 [45.5%]) and genital lymphatics (n = 4/11 [36%]). Abnormal pulmonary/pleural lymphatic perfusion was seen in 8/11 patients (73%). At infancy peripheral/genital edema was more prevalent in patients with RIT1 than PTPN11 (n = 3/5 vs. n = 0/5). Compared to patients with PTPN11 who had fast lymphatic enhancement in 4/5 patients, enhancement took markedly longer in 4/5 patients with RIT1-mutations. Thoracic duct dysplasia, intercostal reflux and pulmonary/pleural lymphatic perfusion are characteristic findings in patients with Noonan syndrome presenting with chylothorax and/or pulmonary lymphangiectasia. Central lymphatic flow abnormalities show possible phenotypical differences between PTPN11 and RIT1-mutations.

Ultrasound-guided needle positioning for nodal dynamic contrast-enhanced MR lymphangiography.

The aim of the study was to assess injection needle positioning for contrast-enhanced MR-lymphangiography (MRL) by ultrasound-guided injection of saline-solution. 80 patients (33 male, mean age 43.1 years) were referred for MRL. The injection needle position was assessed by injection of saline-solution. Consecutive lymph node distension was observed on sonography followed by MRL. Transpedal MRL was performed when no inguinal lymph nodes could be identified. The inguinal lymph node detection rate was recorded. MR-lymphangiograms were assessed regarding primary (i.e. enhancement of draining lymph vessels) and secondary technical success (i.e. lymph vessel enhancement after repositioning of the needle). MRL was considered as clinically successful if enhancement of the central lymphatic system and/or a lymphatic pathologies were observed. For a total of 92 MRLs 177 groins were evaluated sonographically. In 171/177 groins (96.6%) lymph nodes were identified. After needle placement lymph node distension was observed in 171/171 cases (100%) on saline injection. MR-contrast injection demonstrated enhancement of draining lymph vessels in 163/171 cases (95.3%). In 6/171 cases (3.5%) in-bore needle retraction lead to lymphatic enhancement. In one patient [2/171 nodes (1.1%)] no lymphatic enhancement was seen despite repeated needle repositioning. Overall contrast application was technically successful in 169/171 cases (98.8%). In the 6 groins in which no nodes were identifiable, transpedal MRL was successful. So overall 91/92 MRLs (98.9%) were clinically successful. No complications were recorded. Confirmation of the needle position for nodal MRL by sonographically controlled saline injection is a reliable technique with a high success rate of MRL.

Among the S100 proteins, S100A12 is the most significant marker for psoriasis disease activity.

BACKGROUND: Psoriasis is a chronic skin disease with deregulation of proteins in the immune system. These proteins include members of the heterogeneous S100 family, which have been discussed as potential biomarkers for disease severity. OBJECTIVE: The aim of this study was to evaluate the impact of S100A7, S100A8, S100A9 and S100A12 as possible markers for disease activity in patients with psoriasis skin disease. PATIENTS AND METHODS: S100A7, S100A8, S100A9 and S100A12 mRNA expression was determined in the skin of patients with psoriasis and controls (N = 341) by gene expression analyses. In addition, S100 serum levels were investigated by ELISA in an independent cohort of psoriasis patients (i) untreated, with different manifestations (skin/joints), (ii) under treatment (etanercept) and (iii) healthy controls, (N = 55). RESULTS: All S100-subtypes included are significantly upregulated in psoriasis skin lesions when compared with atopic dermatitis, lichen ruber and healthy donors. In untreated psoriasis patients, S100A12-serum levels showed the closest association with disease activity (PASI) (r = 0.542; P < 0.01). Serum levels decreased under treatment with etanercept (P < 0.05). CONCLUSION: Among the investigated S100-proteins, S100A12 showed the closest association with disease activity and therapeutic response and might therefore provide a valuable biomarker for psoriasis.

Modeling the LPS-induced effects on transcription factor activation and gene expression in murine macrophages.

Macrophages within the liver are of particular importance for a functional defense against bacterial infection. They exhibit a complex response to lipopolysaccharide and secrete a variety of pro-inflammatory cytokines and chemokines that both coordinate the immune response and regulate activity of the macrophages, themselves. In this context, the dynamic of pathway activation and gene expression is important for a better understanding of the role of activated macrophages in healthy and diseased states. Therefore, we present a representative model of LPS-induced macrophage activation that covers the principle regulatory motifs. Based on that, we propose a simplified model with a reduced number of states and parameters that allows estimation of transcription factor activity from gene expression data and can be easily extended to describe the full spectrum of gene regulation in LPS-activated macrophages.

Finite-element-modeling of egg white as a substitute for tissue coagulation during bipolar radiofrequency-induced thermofusion.

Radiofrequency-induced thermofusion is a frequently used electrosurgical procedure for the sealing of blood vessels. A disadvantage of vessel sealing instruments is that the generated thermal energy spreads to the surrounding tissue and may irreversibly damage it. This is particularly problematic when operating close to sensitive structures such as nerves. Given their advantages, there is nonetheless a lot of interest in using bipolar vessel sealing for surgical procedures. To select instruments that may be safely used in such cases, it is important to reliably quantify the thermal spread to the surrounding tissue. Mathematical models can help to evaluate the transient behavior, that is the evolution of the thermal spread over time, more precisely. A finite element model allows for a detailed analysis of inhomogeneities in the spatial temperature distribution. As a first step towards a finite model of the bipolar vessel sealing process, a model of the coagulation of chicken egg white is presented here. Egg white has thermal and electrical properties that are very similar to tissue, making it suitable as a substitute for the analysis of the coagulation process. It has the additional advantage, that the spatial and temporal evolution of the thermal spread can be visually gauged. The presented model describes the experimentally observed spatial temperature distribution, the shape of the coagulated egg white, and the formation of hotspots. Furthermore, it is shown that the model can correctly predict the shape of the coagulated egg white in further experiments.

A mathematical model of bipolar radiofrequency-induced thermofusion.

Bipolar radiofrequency-induced thermofusion has become a widely accepted method successfully used in open and particularly in minimally-invasive surgery for the sealing of blood vessels and tissue of up to several millimeters diameter. Despite its wide-spread application, the thermofusion process itself is not well understood on a quantitative and dynamic level, and manufacturers largely rely on trial-and-error methods to improve existing instruments. To predict the effect of alternative generator control strategies and to allow for a more systematic approach to improve thermofusion instruments, a mathematical model of the thermofusion process is developed. The system equations describe the spatial and temporal evolution of the tissue temperature due to Joule heating and heat transfer, and the loss of tissue water due to vaporization. The resulting effects on the tissue properties, most importantly the electrical resistivity, heat capacity and thermal conductivity, are considered as well. Experimental results indicate that the extent of the lateral thermal damage is directly affected by Joule heating of the lateral tissue. The experimental findings are supported by simulation results using the proposed mathematical model of thermofusion.