Search

Time-resolved pump-probe measurements were made at variable heat accumulation in Co/Pd superlattices. Heat accumulation increases the baseline temperature and decreases the equilibrium magnetization. Transient ultrafast demagnetization first develops with higher fluence in parallel with strong equilibrium thermal spin fluctuations. The ultrafast demagnetization is then gradually removed as the equilibrium temperature approaches the Curie temperature. The transient magnetization time-dependence is well fit with the spin-flip scattering model.

Objectives: To study feasibility and validity of a new software application for intraprocedural assessment of perfusion during chemoembolisation of melanoma metastases., Methodology: In a prospective phase-II trial, ten melanoma patients with liver-only metastases underwent chemoembolisation with doxorubicin-eluting beads (DEBDOX-TACE). Tumour perfusion was evaluated immediately before and after treatment at cone beam computer tomography (CBCT) using a new software application. For control and comparison, patients underwent perfusion measurement via contrast-enhanced multidetector CT (MDCT) before and after treatment., Results: CBCT showed 94.7 % reduction in perfusion in metastases after DEBDOX-TACE, whereas MDCT showed 96.8 %. Reduction in perfusion after treatment was statistically significant (p < 0.01) for both methods. The additional time needed for data acquisition during treatment was 5 min per case or less; the post-processing data analysis was 10 min or less. Perfusion imaging was associated with additional contrast agent and patient exposure to radiation (dose-length product [DLP]): 18 ml and 394 mGy*cm in CBCT and 100 ml and 446 mGy*cm in MDCT, respectively., Conclusions: Reduction in perfusion of melanoma metastases after DEBDOX-TACE can be reliably assessed during the intervention via perfusion software at CBCT. Data acquisition and analysis require additional time but can be easily performed during the treatment., Key Points: • Tumour perfusion of melanoma metastases can be assessed at cone beam CT. • The software shows a significant decrease of tumour perfusion after DEBDOX-TACE. • Data acquisition and analysis require an acceptable additional time during the procedure. • CBCT requires less radiation exposure and contrast for perfusion study than MSCT. • This software can monitor the course of DEBDOX-TACE in melanoma metastases.

A model of demagnetizing fields and micromagnetic simulations are applied to examine the evolution of a demagnetized cylinder. In addition to three expected final magnetic structures, a fourth switched state is obtained over a range of magnetic energy densities. The switched state is absent when demagnetizing fields are neglected. The connection to all-optical switching of materials with perpendicular magnetic anisotropy is discussed.

All-optical switching by domain wall motion has been obtained in Co/Pd superlattices with a TiS oscillator. Heat accumulation is part of the switching process for our experimental conditions. Numerical calculations point to a connection between domain wall motion and in-plane heat diffusion.

Background and Aims: Intermediate stage hepatocellular carcinoma (HCC) can be treated by transarterial chemoembolization (TACE). However, there appear to be side effects, such as induction of proangiogenic factors, e.g. vascular endothelial growth factor (VEGF), which have been shown to be associated with a poor prognosis. This prospective study was designed to compare serum VEGF level response after TACE with different embolic agents in patients with HCC. Methods: Patients were assigned to one of three different TACE regimens: degradable starch microspheres (DSM) TACE, drug-eluting bead (DEBDOX) TACE or Lipiodol TACE (cTACE). All patients received 50 mg doxorubicin/m 2 body surface area (BSA) during TACE. Serum VEGF levels were assessed before TACE treatment, 24 h post-treatment and 4 weeks later. Results: Twenty-two patients with 30 TACE treatments were enrolled. Compared to baseline VEGF levels, a marked increase was observed for 24 h post-TACE (164% of baseline level) and during the 4-week follow-up (170% of baseline level) only for the cTACE arm ( p < 0.05). In contrast, the increase of serum VEGF levels were only 114% and 123% for DEBDOX and 121% and 124% for DSM, respectively. Conclusions: Conventional TACE using Lipiodol shows marked increase in blood levels of the proangiogenic factor VEGF, while DEBDOX and DSM TACE induce only a moderate VEGF response., Competing Interests: None

Purpose: This study was designed to evaluate the clinical efficacy of CT-guided bipolar and multipolar radiofrequency ablation (RF ablation) of renal cell carcinoma (RCC) and to analyze specific technical aspects between both technologies., Methods: We included 22 consecutive patients (3 women; age 74.2 ± 8.6 years) after 28 CT-guided bipolar or multipolar RF ablations of 28 RCCs (diameter 2.5 ± 0.8 cm). Procedures were performed with a commercially available RF system (Celon AG Olympus, Berlin, Germany). Technical aspects of RF ablation procedures (ablation mode [bipolar or multipolar], number of applicators and ablation cycles, overall ablation time and deployed energy, and technical success rate) were analyzed. Clinical results (local recurrence-free survival and local tumor control rate, renal function [glomerular filtration rate (GFR)]) and complication rates were evaluated., Results: Bipolar RF ablation was performed in 12 procedures and multipolar RF ablation in 16 procedures (2 applicators in 14 procedures and 3 applicators in 2 procedures). One ablation cycle was performed in 15 procedures and two ablation cycles in 13 procedures. Overall ablation time and deployed energy were 35.0 ± 13.6 min and 43.7 ± 17.9 kJ. Technical success rate was 100 %. Major and minor complication rates were 4 and 14 %. At an imaging follow-up of 15.2 ± 8.8 months, local recurrence-free survival was 14.4 ± 8.8 months and local tumor control rate was 93 %. GFR did not deteriorate after RF ablation (50.8 ± 16.6 ml/min/1.73 m(2) before RF ablation vs. 47.2 ± 11.9 ml/min/1.73 m(2) after RF ablation; not significant)., Conclusions: CT-guided bipolar and multipolar RF ablation of RCC has a high rate of clinical success and low complication rates. At short-term follow-up, clinical efficacy is high without deterioration of the renal function.

Purpose: This study aimed to compare retrospectively bipolar RF ablation with multipolar RF ablation for the treatment of renal cell carcinoma., Materials and Methods: Between March 2009 and June 2012, 12 tumours (nine patients) treated with bipolar RF ablation (one applicator) and 14 tumours (11 patients) treated with multipolar RF ablation (two applicators) were compared systematically. Selection between bipolar RF ablation and multipolar RF ablation was operator choice considering tumour size. Study goals included differences in tumour and coagulation extent, and technical parameters (total RF energy delivery and RF ablation time per coagulation volume)., Results: Tumour maximum diameter was significantly larger for multipolar RF ablation compared with bipolar RF ablation (27.0 mm versus 19.4 mm; p < 0.01). This difference is partially dependent on operator choice. Coagulation length, width and volume were significantly larger for multipolar RF ablation compared with bipolar RF ablation (35.0 mm versus 26.5 mm, 27.5 mm versus 23.0 mm and 14.3 cm(3) versus 8.1 cm(3); p < 0.01, p < 0.05 and p < 0.05, respectively). Coagulation circularity was not significantly different between both study groups (0.8 versus 0.8; not significant). Total RF energy delivery was significantly higher and RF ablation time per coagulation volume was significantly shorter for multipolar RF ablation compared with bipolar RF ablation (52.0 kJ versus 28.6 kJ and 2.4 min/cm(3) versus 4.1 min/cm(3); p < 0.05 and p < 0.05, respectively)., Conclusions: Multipolar RF ablation creates a significantly larger coagulation width, but identical coagulation shape, compared with bipolar RF ablation. Additionally, multipolar RF ablation coagulates faster according to the shorter RF ablation time per coagulation volume.

Background: Epidermodysplasia verruciformis (EV) is a rare autosomal-recessive disorder characterized by widespread and persistent infection with human papilloma virus (HPV) and a risk of malignant degeneration. Most cases of EV are caused by mutations in the two EV genes, EVER1/TMC6 and EVER2/TMC8. The clinical presentation of EV takes two different forms, which coexist in most cases. Over a period of years, patients develop plane warts and pityriasis versicolor-like lesions. Sixteen cases of EV in HIV-positive patients have been clinically investigated and reported in the literature. However, different inherited susceptibilities towards HPV infection in immunodeficient patients, like HIV-positive patients, have only rarely been addressed., Observation: We describe a 22-year-old female patient with a congenital HIV infection, who presented with slowly progressing and confluent erythematous papules on her hands and hypopigmented macules on her extremities. The histopathology was typical for EV, and HPV5 was detected by PCR and reverse hybridization. The 44-year-old HIV-positive mother has no typical EV lesions. The patient is homozygous for an A to T single nucleotide polymorphism (SNP) at position 917 of the TMC8/EVER2 gene. The mother of the patient is heterozygous for this SNP., Conclusion: These results support the hypothesis that the combination of immunodeficiency and a susceptibility allele may contribute to the differences in occurrence of EV in HIV-positive patients., (Copyright (c) 2008 S. Karger AG, Basel.)

Objective: To report a case of lichenoid drug eruption (LDE) after starting antihypertensive treatment with nebivolol, a cardioselective beta-blocker., Case Summary: Five weeks after starting treatment with nebivolol, a 62-year-old woman presented with erythematous papules on both extremities and skin lesions spreading over the back. She was not being treated with any other drugs. Because the administration of levocetirizine, topical methylprednisolone, and systemic prednisone was unsuccessful, the treatment was stopped and the lesions were biopsied. The histopathological features of the lesions were consistent with LDE. After withdrawal of nebivolol and subsequent readministration of topical methylprednisolone and systemic prednisone, the skin lesions resolved within 12 days. Assessment of the causality revealed a probable relationship between nebivolol and the lichenoid eruptions., Discussion: Although beta-blockers can be associated with LDE, as of July 7, 2006, this has not been previously reported with nebivolol. T cells invading the dermis are considered to be responsible for epidermal destruction associated with LDE, as has been described for lichenoid forms of chronic graft versus host disease and idiopathic lichen ruber planus., Conclusions: Nebivolol can cause LDE, as has been reported with other beta-blockers. The underlying mechanism appears to be T cell-mediated. Cross-reactivity with other beta-blockers cannot be excluded; therefore, the risk of recurrent LDE should be weighed carefully against the clinical benefit before switching to another beta-blocker.