PDE2 is markedly up-regulated in failing hearts and desensitizes against acute β-AR stimulation. This may constitute an important defense mechanism during cardiac stress, for example, by antagonizing excessive β-AR drive. Thus, activating myocardial PDE2 may represent a novel intracellular antiadrenergic therapeutic strategy in HF.
BRCA1/2 mutation status leads to better responses to neoadjuvant chemotherapy in breast cancer. Pathological complete response is the main predictor of disease-free survival and overall survival, independently of BRCA1/2 mutation status.
Recent studies suggest that the signal molecules cAMP and cGMP have antifibrotic effects by negatively regulating pathways associated with fibroblast to myofibroblast (MyoCF) conversion. The phosphodiesterase 2 (PDE2) has the unique property to be stimulated by cGMP, which leads to a remarkable increase in cAMP hydrolysis and thus mediates a negative cross-talk between both pathways. PDE2 has been recently investigated in cardiomyocytes; here we specifically addressed its role in fibroblast conversion and cardiac fibrosis. PDE2 is abundantly expressed in both neonatal rat cardiac fibroblasts (CFs) and cardiomyocytes. The overexpression of PDE2 in CFs strongly reduced basal and isoprenaline-induced cAMP synthesis, and this decrease was sufficient to induce MyoCF conversion even in the absence of exogenous profibrotic stimuli. Functional stress-strain experiments with fibroblast-derived engineered connective tissue (ECT) demonstrated higher stiffness in ECTs overexpressing PDE2. In regard to cGMP, neither basal nor atrial natriuretic peptide-induced cGMP levels were affected by PDE2, whereas the response to nitric oxide donor sodium nitroprusside was slightly but significantly reduced. Interestingly, despite persistently depressed cAMP levels, both cGMP-elevating stimuli were able to completely prevent the PDE2-induced MyoCF phenotype, arguing for a double-tracked mechanism. In conclusion, PDE2 accelerates CF to MyoCF conversion, which leads to greater stiffness in ECTs. Atrial natriuretic peptide- and sodium nitroprusside-mediated cGMP synthesis completely reverses PDE2-induced fibroblast conversion. Thus PDE2 may augment cardiac remodeling, but this effect can also be overcome by enhanced cGMP. The redundant role of cAMP and cGMP as antifibrotic meditators may be viewed as a protective mechanism in heart failure.
We used a shifted-excitation Raman difference spectroscopy method for the ex
vivo classification of resected and formalin-fixed breast tissue samples as
normal (healthy) tissue, fibroadenoma, or invasive carcinoma. We analyzed 8 tissue samples
containing invasive carcinoma that were surrounded by normal tissue and 3 tissue samples
with fibroadenoma only. We made various measurement sites on various tissue samples, in
total 240 measurements for each type of tissue. Although the acquired raw spectra contain
enough information to clearly differentiate between normal and tumor (fibroadenoma and
invasive carcinoma) tissue, the differentiation between fibroadenoma and invasive
carcinoma was possible only after the shifted-excitation Raman difference spectroscopy
isolation of pure Raman spectra from the heavily fluorescence interfered raw spectra. We
used 784 and 785 nm as excitation wavelengths for the shifted-excitation Raman difference
spectroscopy method. The differences in the obtained pure Raman spectra are assigned to
the different chemical compositions of normal breast tissue, fibroadenoma, and invasive
breast carcinoma. Principal component analysis and linear discriminant analysis showed
excellent classification results in the Raman shift range between 1000 and 1800
cm−1. Invasive breast carcinoma was identified with 99.15% sensitivity, and
the absence of invasive carcinoma was identified with 90.40% specificity. Tumor tissue in
tumor-containing tissue was identified with 100% sensitivity, and the absence of tumor in
no-tumor containing tissue was identified with 100% specificity. As gold standard for the
determination of the sensitivity and the specificity, we considered the conventional
histopathological classification. In summary, shifted-excitation Raman difference
spectroscopy could be potentially very useful to support histopathological diagnosis in
breast pathology.
The effect of pregnancies on mammographic density does not appear to become apparent before the age of menopause. The mechanism that drives the effect of pregnancies on mammographic density appears to be counter-regulated by other influences on mammographic density in younger patients.
Aim The combination of different imaging modalities through the use of fusion devices promises significant diagnostic improvement for breast pathology. The aim of this study was to evaluate image quality and clinical feasibility of a prototype fusion device (fusion prototype) constructed from a standard tomosynthesis mammography unit and a standard 3D ultrasound probe using a new method of breast compression.
Materials and Methods Imaging was performed on 5 mastectomy specimens from patients with confirmed DCIS or invasive carcinoma (BI-RADS™ 6). For the preclinical fusion prototype an ABVS system ultrasound probe from an Acuson S2000 was integrated into a MAMMOMAT Inspiration (both Siemens Healthcare Ltd) and, with the aid of a newly developed compression plate, digital mammogram and automated 3D ultrasound images were obtained.
Results The quality of digital mammogram images produced by the fusion prototype was comparable to those produced using conventional compression. The newly developed compression plate did not influence the applied x-ray dose. The method was not more labour intensive or time-consuming than conventional mammography. From the technical perspective, fusion of the two modalities was achievable.
Conclusion In this study, using only a few mastectomy specimens, the fusion of an automated 3D ultrasound machine with a standard mammography unit delivered images of comparable quality to conventional mammography. The device allows simultaneous ultrasound – the second important imaging modality in complementary breast diagnostics – without increasing examination time or requiring additional staff.
The primary objective of the study was to compare a spiral breast computed tomography system (SBCT) to digital breast tomosynthesis (DBT) for the detection of microcalcifications (MCs) in breast specimens. The secondary objective was to compare various reconstruction modes in SBCT. In total, 54 breast biopsy specimens were examined with mammography as a standard reference, with DBT, and with a dedicated SBCT containing a photon-counting detector. Three different reconstruction modes were applied for SBCT datasets (Recon1 = voxel size (0.15 mm)3, smooth kernel; Recon2 = voxel size (0.05 mm)3, smooth kernel; Recon3 = voxel size (0.05 mm)3, sharp kernel). Sensitivity and specificity of DBT and SBCT for the detection of suspicious MCs were analyzed, and the McNemar test was used for comparisons. Diagnostic confidence of the two readers (Likert Scale 1 = not confident; 5 = completely confident) was analyzed with ANOVA. Regarding detection of MCs, reader 1 had a higher sensitivity for DBT (94.3%) and Recon2 (94.9%) compared to Recon1 (88.5%; p < 0.05), while sensitivity for Recon3 was 92.4%. Respectively, reader 2 had a higher sensitivity for DBT (93.0%), Recon2 (92.4%), and Recon3 (93.0%) compared to Recon1 (86.0%; p < 0.05). Specificities ranged from 84.7–94.9% for both readers (p > 0.05). The diagnostic confidence of reader 1 was better with SBCT than with DBT (DBT 4.48 ± 0.88, Recon1 4.77 ± 0.66, Recon2 4.89 ± 0.44, and Recon3 4.75 ± 0.72; DBT vs. Recon1/2/3: p < 0.05), while reader 2 found no differences. Sensitivity and specificity for the detection of MCs in breast specimens is equal for DBT and SBCT when a small voxel size of (0.05 mm)3 is used with an equal or better diagnostic confidence for SBCT compared to DBT.
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