Hodgkin lymphoma: hypodense lesions in mediastinal masses.

Hypodense volumes (HDV) in mediastinal masses can be visualized in a computed tomography scan in Hodgkin lymphoma. We analyzed staging CT scans of 1178 patients with mediastinal involvement from the EuroNet-PHL-C1 trial and explored correlations of HDV with patient characteristics, mediastinal tumor volume and progression-free survival. HDV occurred in 350 of 1178 patients (29.7%), typically in larger mediastinal volumes. There were different patterns in appearance with single lesions found in 243 patients (69.4%), multiple lesions in 107 patients (30.6%). Well delineated lesions were found in 248 cases (70.1%), diffuse lesions were seen in 102 cases (29.1%). Clinically, B symptoms occurred more often in patients with HDV (47.7% compared to 35.0% without HDV (p = 0.039)) and patients with HDV tended to be in higher risk groups. Inadequate overall early-18F-FDG-PET-response was strongly correlated with the occurrence of hypodense lesions (p < 0.001). Patients with total HDV > 40 ml (n = 80) had a 5 year PFS of 79.6% compared to 89.7% (p = 0.01) in patients with HDV < 40 ml or no HDV. This difference in PFS is not caused by treatment group alone. HDV is a common phenomenon in HL with mediastinal involvement.

Safety and Effectiveness of Ethylene Vinyl Alcohol Copolymer Embolization of Peripheral High-Flow Arteriovenous Malformations: Results of a Prospective Study.

PURPOSE: To prospectively evaluate the efficacy and safety of a new ethylene vinyl alcohol (EVOH) copolymer-based embolic agent in the treatment of symptomatic peripheral arteriovenous malformations (AVMs). MATERIALS AND METHODS: This prospective single-center study evaluated EVOH embolization with 3 different formulations of EVOH (Squid Peri 12 cP, 18 cP, and 34 cP; BALT Germany GmbH, Düsseldorf, Germany) in patients with symptomatic AVMs. Between April 2018 and October 2019, 36 embolization procedures in 21 patients (3 males and 18 females; mean age, 34.7 years) were performed (inclusion criteria: symptomatic peripheral AVM, ≥14 years of age, and elective embolization). Symptoms, technical aspects (transarterial, transvenous, or percutaneous approach; plug or balloon occlusion), clinical and technical success (defined as the improvement of symptoms and complete angiographic eradication of the AVM nidus), adverse events, and short-term outcomes were assessed. RESULTS: The mean volume of the embolic agent used per session was 3.4 mL of EVOH 34 cP (standard deviation [SD], ± 5.4), 6.2 mL ± 8.1 of EVOH 18 cP, and 4.6 mL ± 10.1 of EVOH 12 cP. Angiographic success was achieved in 18 patients (85.7%). The mean follow-up was 190 days (range, 90-538 days; median, 182 days). In the follow-up assessment, findings of magnetic resonance imaging showed that 19 patients (90.5%) had a persistent state of devascularization compared with postinterventional angiography. Amelioration or complete elimination of pain was achieved in 90.0% of the patients. One patient experienced a major adverse event; minor adverse events developed in 2 patients. CONCLUSIONS: In this study, EVOH appeared to be a safe and effective embolic agent in peripheral AVMs and had a low rate of adverse events in a limited number of patients.

Assessment of Waldeyer's ring in pediatric and adolescent Hodgkin lymphoma patients-Importance of multimodality imaging: Results from the EuroNet-PHL-C1 trial.

BACKGROUND: In the EuroNet Pediatric Hodgkin Lymphoma (EuroNet-PHL) trials, decision on Waldeyer's ring (WR) involvement is usually based on clinical assessment, that is, physical examination and/or nasopharyngoscopy. However, clinical assessment only evaluates mucosal surface and is prone to interobserver variability. Modern cross-sectional imaging technology may provide valuable information beyond mucosal surface, which may lead to a more accurate WR staging. PATIENTS, MATERIALS, AND METHODS: The EuroNet-PHL-C1 trial recruited 2102 patients, of which 1752 underwent central review including reference reading of their cross-sectional imaging data. In 14 of 1752 patients, WR was considered involved according to clinical assessment. In these 14 patients, the WR was re-assessed by applying an imaging-based algorithm considering information from 18 F-fluorodeoxyglucose positron emission tomography, contrast-enhanced computed tomography, and/or magnetic resonance imaging. For verification purposes, the imaging-based algorithm was applied to 100 consecutive patients whose WR was inconspicuous on clinical assessment. RESULTS: The imaging-based algorithm confirmed WR involvement only in four of the 14 patients. Of the remaining 10 patients, four had retropharyngeal lymph node involvement and six an inconspicuous WR. Applying the imaging-based algorithm to 100 consecutive patients with physiological appearance of their WR on clinical assessment, absence of WR involvement could be confirmed in 99. However, suspicion of WR involvement was raised in one patient. CONCLUSIONS: The imaging-based algorithm was feasible and easily applicable at initial staging of young patients with Hodgkin lymphoma. It increased the accuracy of WR staging, which may contribute to a more individualized treatment in the future.

Effects of effective stereotactic radiosurgery for brain metastases on the adjacent brain parenchyma.

BACKGROUND: To evaluate whether functional and metabolic MRI can detect radiation-induced alterations in the adjacent areas after effective stereotactic radiosurgery (SRS) for brain metastases. If confirmed, these techniques may be suited for monitoring the timely stratification of patients for neuroprotective treatments after irradiation. METHODS: Inclusion criteria were complete response, partial response, or stable disease on routine follow-up MR-scans. Multiparametric 3T-MRI was performed with diffusion-weighted imaging, dynamic susceptibility perfusion-weighted imaging, and two-dimensional proton MR-spectroscopy. Parameters were measured in the SRS-treated target and in the adjacent parenchyma up to both 0.75 cm and 1.5 cm from the target border. RESULTS: Nineteen lesions in sixteen consecutive patients met the inclusion criteria. The median follow-up time was 39 months (range, 10-142) with 41 multiparametric MR-examinations in total. We found low values of N-acetyl-aspartate up to 1.5 cm from the target borders of SRS (P = 0.043) associated with high values of choline (P = 0.004) at the end of the observation period. Lactate levels in the adjacent tissue declined over time, whereas continuously high apparent-diffusion-coefficient values were noted (P < 0.001). CONCLUSION: Multiparametric MRI can depict radiobiological effects and their time course at a distance from the effectively treated site after SRS for brain metastases, even if conventional MRI findings are inconspicuous.

Safety and effectiveness of percutaneous sclerotherapy for venous disorders of the labia majora in patients with vascular malformations.

OBJECTIVE: The aim of this study was to evaluate the safety and clinical outcomes of percutaneous sclerotherapy of venous disorders of the labia majora in patients with vascular malformations of the lower limbs. METHODS: Thirty percutaneous sclerotherapy treatments were performed over a 6-year period among 17 female patients with symptomatic venous malformation (VM) or secondary varicosis of the labia majora. Four patients were treated with sclerotherapy alone, 13 patients had additional procedures to control the VM before sclerotherapy. Polidocanol was used as sclerosant. Indications for sclerotherapy included pain, bleeding, thrombophlebitis, and swelling. Genitourinary symptoms were recorded. The number of treatments and procedure-related complications were registered. Complications were classified according to the Society of Interventional Radiology (SIR) classification system (grade A-E). The 3-month postintervention follow-up included magnetic resonance imaging, clinical examination, and a symptom-related questionnaire. If no reintervention was necessary, consultation was scheduled biannually. RESULTS: All patients had local swelling and pain; only a fraction of the patients had further symptoms with bleeding or thrombophlebitis (47% each). Eight patients required reintervention. No major complications were observed; minor complications such as postprocedural swelling occurred in 29% (SIR grade A), pain occurred in 17% (SIR grade B), and skin blistering developed in 5% (SIR grade B). Upon follow-up examination after a median of 40 months, 76% showed complete relief of symptoms, and 23% reported partial relief. All patients reported a substantial reduction in pain (75% >5 points in visual analogue scale) and swelling (88% complete cessation). CONCLUSIONS: Percutaneous sclerotherapy is a safe and effective treatment option of VM and secondary varicosis of the labia majora.

Live-cell lipid biochemistry reveals a role of diacylglycerol side-chain composition for cellular lipid dynamics and protein affinities.

Every cell produces thousands of distinct lipid species, but insight into how lipid chemical diversity contributes to biological signaling is lacking, particularly because of a scarcity of methods for quantitatively studying lipid function in living cells. Using the example of diacylglycerols, prominent second messengers, we here investigate whether lipid chemical diversity can provide a basis for cellular signal specification. We generated photo-caged lipid probes, which allow acute manipulation of distinct diacylglycerol species in the plasma membrane. Combining uncaging experiments with mathematical modeling, we were able to determine binding constants for diacylglycerol-protein interactions, and kinetic parameters for diacylglycerol transbilayer movement and turnover in quantitative live-cell experiments. Strikingly, we find that affinities and kinetics vary by orders of magnitude due to diacylglycerol side-chain composition. These differences are sufficient to explain differential recruitment of diacylglycerol binding proteins and, thus, differing downstream phosphorylation patterns. Our approach represents a generally applicable method for elucidating the biological function of single lipid species on subcellular scales in quantitative live-cell experiments.

Discovery of BAY-298 and BAY-899: Tetrahydro-1,6-naphthyridine-Based, Potent, and Selective Antagonists of the Luteinizing Hormone Receptor Which Reduce Sex Hormone Levels in Vivo.

The human luteinizing hormone receptor (hLH-R) is a member of the glycoprotein hormone family of G-protein-coupled receptors (GPCRs), activated by luteinizing hormone (hLH) and essentially involved in the regulation of sex hormone production. Thus, hLH-R represents a valid target for the treatment of sex hormone-dependent cancers and diseases (polycystic ovary syndrome, uterine fibroids, endometriosis) as well as contraception. Screening of the Bayer compound library led to the discovery of tetrahydrothienopyridine derivatives as novel, small-molecule (SMOL) hLH-R inhibitors and to the development of BAY-298, the first nanomolar hLH-R antagonist reducing sex hormone levels in vivo. Further optimization of physicochemical, pharmacokinetic, and safety parameters led to the identification of BAY-899 with an improved in vitro profile and proven efficacy in vivo. BAY-298 and BAY-899 serve as valuable tool compounds to study hLH-R signaling in vitro and to interfere with the production of sex hormones in vivo.

Novel TIE-2 inhibitor BAY-826 displays in vivo efficacy in experimental syngeneic murine glioma models.

Targeting the vascular endothelial growth factor signaling axis in glioblastoma inevitably leads to tumor recurrence and a more aggressive phenotype. Therefore, other angiogenic pathways, like the angiopoietin/tunica interna endothelial cell kinase (TIE) signaling axis, have become additional targets for therapeutic intervention. Here, we explored whether targeting the receptor tyrosine kinase TIE-2 using a novel, highly potent, orally available small molecule TIE-2 inhibitor (BAY-826) improves tumor control in syngeneic mouse glioma models. BAY-826 inhibits TIE-2 phosphorylation in vitro and in vivo as demonstrated by suppression of Angiopoietin-1- or Na3 VO4 -induced TIE-2 phosphorylation in glioma cells or extracts of lungs from BAY-826-treated mice. There was a trend toward prolonged survival upon single-agent treatment in two of four models (SMA-497 and SMA-540) and there was a significant survival benefit in one model (SMA-560). Co-treatment with BAY-826 and irradiation was ineffective in one model (SMA-497), but provided synergistic prolongation of survival in another (SMA-560). Decreased vessel densities and increased leukocyte infiltration were observed, but might be independent processes as the effect was also observed in single treatment modalities. These data demonstrate that TIE-2 inhibition may improve tumor response to treatment in highly vascularized tumors such as glioblastoma.

Technique for comprehensive head and neck irradiation using 3-dimensional conformal proton therapy.

Owing to the technical and logistical complexities of matching photon and proton treatment modalities, we developed and implemented a technique of comprehensive head and neck radiation using 3-dimensional (3D) conformal proton therapy. A monoisocentric technique was used with a 30-cm snout. Cervical lymphatics were treated with 3 fields: a posterior-anterior field with a midline block and a right and a left posterior oblique field. The matchline of the 3 cervical nodal fields with the primary tumor site fields was staggered by 0.5cm. Comparative intensity-modulated photon plans were later developed for 12 previously treated patients to provide equivalent target coverage, while matching or improving on the proton plans׳ sparing of organs at risk (OARs). Dosimetry to OARs was evaluated and compared by treatment modality. Comprehensive head and neck irradiation using proton therapy yielded treatment plans with significant dose avoidance of the oral cavity and midline neck structures. When compared with the generated intensity-modulated radiation therapy (IMRT) plans, the proton treatment plans yielded statistically significant reductions in the mean and integral radiation dose to the oral cavity, larynx, esophagus, and the maximally spared parotid gland. There was no significant difference in mean dose to the lesser-spared parotid gland by treatment modality or in mean or integral dose to the spared submandibular glands. A technique for cervical nodal irradiation using 3D conformal proton therapy with uniform scanning was developed and clinically implemented. Use of proton therapy for cervical nodal irradiation resulted in large volume of dose avoidance to the oral cavity and low dose exposure to midline structures of the larynx and the esophagus, with lower mean and integral dose to assessed OARs when compared with competing IMRT plans.

Evaluation of treatment response after chemoembolisation (TACE) in hepatocellular carcinoma using real time image fusion of contrast-enhanced ultrasound (CEUS) and computed tomography (CT)--preliminary results.

OBJECTIVE: To evaluate treatment response of hepatocellular carcinoma (HCC) after transarterial chemoembolization (TACE) with a new real-time imaging fusion technique of contrast-enhanced ultrasound (CEUS) with multi-slice detection computed tomography (CT) in comparison to conventional post-interventional follow-up. MATERIAL AND METHODS: 40 patients with HCC (26 male, ages 46-81 years) were evaluated 24 hours after TACE using CEUS with ultrasound volume navigation and image fusion with CT compared to non-enhanced CT and follow-up contrast-enhanced CT after 6-8 weeks. Reduction of tumor vascularization to less than 25% was regarded as "successful" treatment, whereas reduction to levels >25% was considered as "partial" treatment response. Homogenous lipiodol retention was regarded as successful treatment in non-enhanced CT. RESULTS: Post-interventional image fusion of CEUS with CT was feasible in all 40 patients. In 24 patients (24/40), post-interventional image fusion with CEUS revealed residual tumor vascularity, that was confirmed by contrast-enhanced CT 6-8 weeks later in 24/24 patients. In 16 patients (16/40), post-interventional image fusion with CEUS demonstrated successful treatment, but follow-up CT detected residual viable tumor (6/16). Non-enhanced CT did not identify any case of treatment failure. Image fusion with CEUS assessed treatment efficacy with a specificity of 100%, sensitivity of 80% and a positive predictive value of 1 (negative predictive value 0.63). CONCLUSIONS: Image fusion of CEUS with CT allows a reliable, highly specific post-interventional evaluation of embolization response with good sensitivity without any further radiation exposure. It can detect residual viable tumor at early state, resulting in a close patient monitoring or re-therapy.

The SNAP-25 linker as an adaptation toward fast exocytosis.

The assembly of four soluble N-ethylmaleimide-sensitive factor attachment protein receptor domains into a complex is essential for membrane fusion. In most cases, the four SNARE-domains are encoded by separate membrane-targeted proteins. However, in the exocytotic pathway, two SNARE-domains are present in one protein, connected by a flexible linker. The significance of this arrangement is unknown. We characterized the role of the linker in SNAP-25, a neuronal SNARE, by using overexpression techniques in synaptosomal-associated protein of 25 kDa (SNAP-25) null mouse chromaffin cells and fast electrophysiological techniques. We confirm that the palmitoylated linker-cysteines are important for membrane association. A SNAP-25 mutant without cysteines supported exocytosis, but the fusion rate was slowed down and the fusion pore duration prolonged. Using chimeric proteins between SNAP-25 and its ubiquitous homologue SNAP-23, we show that the cysteine-containing part of the linkers is interchangeable. However, a stretch of 10 hydrophobic and charged amino acids in the C-terminal half of the SNAP-25 linker is required for fast exocytosis and in its absence the calcium dependence of exocytosis is shifted toward higher concentrations. The SNAP-25 linker therefore might have evolved as an adaptation toward calcium triggering and a high rate of execution of the fusion process, those features that distinguish exocytosis from other membrane fusion pathways.

Comparative analysis of the uterine and mammary gland effects of drospirenone and medroxyprogesterone acetate.

The role of progestins in combined hormone therapy is the inhibition of uterine epithelial cell proliferation. The Women's Health Initiative study provided evidence for an increased risk of breast cancer in women treated with conjugated equine estrogens plus the synthetic progestin medroxyprogesterone acetate (MPA), compared with conjugated equine estrogens-only treatment. These findings continue to be discussed, and it remains to be clarified whether the results obtained for MPA in the Women's Health Initiative study are directly applicable to other progestins used in hormone therapy. In this study we compared in a mouse model the effects of the synthetic progestins, MPA, and drospirenone in two major target organs: the uterus and mammary gland. As quantitative measures of progestin activity, we analyzed maintenance of pregnancy, ductal side branching in the mammary gland, and proliferation of mammary and uterine epithelial cells as well as target gene induction in both organs. The outcome of this study is that not all synthetic progestins exhibit the same effects. MPA demonstrated uterine activity and mitogenic activity in the mammary gland at the same doses. In contrast, drospirenone behaved similarly to the natural hormone, progesterone, and exhibited uterine activity at doses lower than those leading to considerable proliferative effects in the mammary gland. We hypothesize that the safety of combined hormone therapy in postmenopausal women may be associated with a dissociation between the uterine and mammary gland activities of the progestin component.

Protein-structure-based prediction of animal model suitability for pharmacodynamic studies of subtype-selective estrogens.

Subtype-selective estrogens are of increasing importance as tools used to unravel physiological roles of the estrogen receptors, ERalpha and ERbeta, in various species. Although human ERalpha and ERbeta differ by only two amino acids within the binding pockets, we and others recently succeeded in generating subtype-selective agonists. We have proposed that the selectivity of the steroidal compounds 16alpha-lactone-estradiol (16alpha-LE(2), hERalpha selective) and 8beta-vinyl-estradiol (8beta-VE(2), hERbeta selective) is based on the interaction of certain substituents of these compounds with essentially one amino acid in the respective ER binding pockets. For in vitro and ex vivo pharmacological experiments with these compounds we intended to use bovine tissues available from slaughterhouses in larger quantities. Using homology modeling techniques we determined that the amino acid conferring high hERbeta-selectivity to 8beta-VE(2) is not exchanged between human and bovine ERalpha and bovine ERbeta. Thus, we predicted our steroidal hERbeta-selective compound to exhibit only weak agonistic activity at bERbeta and that bovine tissue is therefore not suited for investigation of ERbeta functions. The situation is presumably identical for pig, sheep, and the common marmoset, whereas rats, mice, and rhesus macaques are appropriate animal models to study pharmacological effects of 8beta-VE(2) in vivo. This prediction was confirmed in transactivation studies assessing estradiol (E(2)) and the two subtype-selective ligands on bovine ERbeta and on a series of hERalpha and hERbeta with mutations in their respective ligand-binding pockets. We have shown that the detailed understanding of the interactions of a compound with its target protein enables the identification of relevant species for pharmacological studies.

Dissecting physiological roles of estrogen receptor alpha and beta with potent selective ligands from structure-based design.

The distinct roles of the two estrogen receptor (ER) isotypes, ERalpha and ERbeta, in mediating the physiological responses to estrogens are not completely understood. Although knockout animal experiments have been aiding to gain insight into estrogen signaling, additional information on the function of ERalpha and ERbeta will be provided by the application of isotype-selective ER agonists. Based on the crystal structure of the ERalpha ligand binding domain and a homology model of the ERbeta-ligand binding domain, we have designed steroidal ligands that exploit the differences in size and flexibility of the two ligand binding cavities. Compounds predicted to bind preferentially to either ERalpha or ERbeta were synthesized and tested in vitro using radio-ligand competition and transactivation assays. This approach directly led to highly ER isotype-selective (approximately 200-fold) and potent ligands. To unravel physiological roles of the two receptors, in vivo experiments with rats were conducted using the ERalpha- and ERbeta-selective agonists in comparison to 17beta-estradiol. The ERalpha agonist induced uterine growth, caused bone-protective effects, reduced LH and FSH plasma levels, and increased angiotensin I, whereas the ERbeta agonist did not at all or only at high doses lead to such effects, despite high plasma levels. It can thus be concluded that estrogen effects on the uterus, pituitary, bone, and liver are primarily mediated via ERalpha. Simultaneous administration of the ERalpha and ERbeta ligand did not lead to an attenuation of ERalpha-mediated effects on the uterus, pituitary, and liver parameters.

Impact of isotype-selective estrogen receptor agonists on ovarian function.

Other isotype-selective estrogen receptor (ER) agonists, the selective ERalpha agonist 3,17-dihydroxy-19-nor-17alpha-pregna-1,3,5 (10)-triene-21,16alpha-lactone and the selective ERbeta agonist 8-vinylestra-1,3,5 (10)-triene-3,17beta-diol, were used in hypophysectomized rats, gonadotropin-releasing hormone antagonist-treated mice, as well as intact rats to elucidate the effects of isotype-selective estrogens on the physiology of folliculogenesis and ovulation. In hypophysectomized rats and gonadotropin-releasing hormone antagonist-treated mice, the ERbeta agonist caused stimulation of early folliculogenesis, a decrease in follicular atresia, induction of ovarian gene expression, and stimulation of late follicular growth, accompanied by an increase in the number of ovulated oocytes similar to 17beta-estradiol (E2). In contrast, the ERalpha agonist had little or no effect on these parameters, implying that direct estrogen effects on ovarian follicular development are mediated by ERbeta. In intact rats, E2 and the ERalpha agonist dose-dependently inhibited ovulation, in contrast to the ERbeta agonist. On the other hand, the ERbeta agonist did not stimulate uterine weight in intact rats, in contrast to E2 and the ERalpha agonist. This finding is in line with the assumption that estrogen mediated ovulation inhibition and stimulation of uterine growth are mediated by ERalpha but not by ERbeta