Should we report Breslow density, a new concept in cutaneous melanoma?

INTRODUCTION: Breslow density is a newly defined biomarker, independent of Breslow thickness. We aimed to investigate the relationship of Breslow density with other clinicopathological prognostic factors and its effect on the overall survival and disease-free survival in patients with cutaneous melanomas. MATERIALS & METHODS: This was a single-centre retrospective study of patients (n = 19) diagnosed with cutaneous malignant melanomas in our hospital between 2011 and 2019 were included in the study. The exclusion criteria were in situ melanomas, punch or incisional biopsies and metastasis at the time of the diagnosis. Breslow density was determined by reevaluating slides obtained at the time of the initial diagnoses. The effect of Breslow density on survival was determined using univariate and multivariate Cox proportional risk analyses. RESULTS: In terms of the overall survival, mortality risk increased as Breslow density increased (p = 0.044). Breslow density was not significantly associated with the overall survival in the multivariate model (p = 0.078). In terms of disease-free survival, the risk of metastasis or recurrence increased 1.229- fold in accordance with an increase in Breslow thickness (CI: 1.057-1.428), whereas increased Breslow density increased the metastasis or recurrence risk 1.059-fold (CI: 1.008-1.112). In the multivariate model, only Breslow density was statistically significant (p = 0.046). CONCLUSIONS: As a semi-quantitative and subjective measurement, Breslow density is not a completely accurate representation of the invasive tumour load. However, the measurement is practical and low cost and requires no additional equipment. Therefore, Breslow density can be measured in every laboratory. Considering the value of Breslow density in predicting the prognosis in patients with cutaneous melanomas and strong inter-observer compliance observed in the present study, we believe that it would be useful to include this measurement in pathology reports.

Iterative reconstruction of magnetic induction using Lorentz transmission electron tomography.

Intense ongoing research on complex nanomagnetic structures requires a fundamental understanding of the 3D magnetization and the stray fields around the nano-objects. 3D visualization of such fields offers the best way to achieve this. Lorentz transmission electron microscopy provides a suitable combination of high resolution and ability to quantitatively visualize the magnetization vectors using phase retrieval methods. In this paper, we present a formalism to represent the magnetic phase shift of electrons as a Radon transform of the magnetic induction of the sample. Using this formalism, we then present the application of common tomographic methods particularly the iterative methods, to reconstruct the 3D components of the vector field. We present an analysis of the effect of missing wedge and the limited angular sampling as well as reconstruction of complex 3D magnetization in a nanowire using simulations.

Anisotropic conductivity tensor imaging using magnetic induction tomography.

Magnetic induction tomography aims to reconstruct the electrical conductivity distribution of the human body using non-contact measurements. The potential of the method has been demonstrated by various simulation studies and a number of phantom experiments. These studies have all relied on models having isotropic distributions of conductivity, although the human body has a highly heterogeneous structure with partially anisotropic properties. Therefore, whether the conventional modeling approaches used so far are appropriate for clinical applications or not is still an open question. To investigate the problem, we performed a simulation study to investigate the feasibility of (1) imaging anisotropic perturbations within an isotropic medium and (2) imaging isotropic perturbations inside a partially anisotropic background. The first is the case for the imaging of anomalies that have anisotropic characteristics and the latter is the case e.g. in lung imaging where an anisotropic skeletal muscle tissue surrounds the lungs and the rib cage. An anisotropic solver based on the singular value decomposition was used to attain conductivity tensor images to be compared with the ones obtained from isotropic solvers. The results indicate the importance of anisotropic modeling in order to obtain satisfactory reconstructions, especially for the imaging of the anisotropic anomalies, and address the resolvability of the conductivity tensor components.

Reconstruction artefacts in magnetic induction tomography due to patient's movement during data acquisition.

Magnetic induction tomography (MIT) attempts to obtain the distribution of passive electrical properties inside the body. Eddy currents are induced in the body using an array of transmitter coils and the magnetic fields of these currents are measured by receiver coils. In clinical usage, the relative position of the coils to the body can change during data acquisition because of the expected/unexpected movements of the patient. Especially in respiration monitoring these movements will inevitably cause artefacts in the reconstructed images. In this paper, this effect was investigated for both state and frequency differential variants of MIT. It was found that a slight shift of the body in the transverse plane causes spurious perturbations on the surface. In reconstructions, this artefact on the surface propagates towards the centre in an oscillatory manner. It was observed that the movement can corrupt all the valuable information in state differential MIT, while frequency differential MIT seems more robust against movement effects. A filtering strategy is offered in order to decrease the movement artefacts in the images. To this end, monitoring of the patient's movement during data acquisition is required.

Frequent detection of hepatitis B core antibodies in heart transplant recipients without preceding hepatitis B infection.

It is unclear whether heart donors positive for hepatitis B core antibodies (anti-HBc) can transfer hepatitis B virus (HBV) infection to immunosuppressed heart recipients, or whether passive transfer of anti-HBc simulates a hepatitis B infection. Therefore, we performed a case-controlled study in 46 heart recipients who all tested negative for hepatitis B antigen (HbsAg), antiHBc, and hepatitis B surface antibodies before heart transplantation. Twenty-three patients (group 1) received hearts from anti-HBc-positive donors, while 23 other patients (group 2) received hearts from anti-HBc-negative donors. After heart transplantation, anti-HBc were present in 65.0% of blood samples among group 1 and 47.8% of the blood samples among group 2 (P > .05). HbsAg was undetectable in blood samples of all patients of both study groups. The immunoglobulin preparation that we regularly use for immune suppression immediately after heart transplantation contained a relatively high concentration of anti-Hbc antibodies. The nearly identical presence of anti-HBc in both study groups indicated that passive transfer via immunoglobulin preparations rather than HBV infection is the cause for the anti-HBc detected in heart recipients. Since only a small volume of blood is transferred with the donor heart, it seems to be rather unlikely that the donor heart might be the source of anti-HBc. In summary, we observed no evidence for HBV infection in those heart recipients who received organs from anti-HBc-positive donors. Moreover, our data demonstrated that the presence of anti-HBc in heart recipients frequently occurs but does not necessarily indicate a preceding HBV infection.