3,985 research outputs found
Unexpected Metastasis of High Grade Serous Ovarian Cancer to Breast: Case Report and Literature Review
Introduction: Metastasis of ovarian serous carcinoma to breast and/or axillary lymph nodes represents an unusual event. Nevertheless, their detection and distinction from mammary carcinoma are of huge clinical importance because the treatment and prognosis diverge significantly. Case presentation: We report a case of a 47 year-old Caucasian female patient with unforeseen metastasis to the breast and to axillary lymph nodes due to ovarian serous carcinoma. Conclusion: In patients with history of OSC who present with axillary or breast mass, an accurate histological diagnosis should be obtained since this has a great impact on treatment outcomes
Structural determinants in ApoA-I amyloidogenic variants explain improved cholesterol metabolism despite low HDL levels.
Twenty Apolipoprotein A-I (ApoA-I) variants are responsible for a systemic hereditary amyloidosis in which protein fibrils can accumulate in different organs, leading to their failure. Several ApoA-I amyloidogenic mutations are also associated with hypoalphalipoproteinemia, low ApoA-I and high-density lipoprotein (HDL)-cholesterol plasma levels; however, subjects affected by ApoA-I-related amyloidosis do not show a higher risk of cardiovascular diseases (CVD). The structural features, the lipid binding properties and the functionality of four ApoA-I amyloidogenic variants were therefore inspected in order to clarify the paradox observed in the clinical phenotype of the affected subjects. Our results show that ApoA-I amyloidogenic variants are characterized by a different oligomerization pattern and that the position of the mutation in the ApoA-I sequence affects the molecular structure of the formed HDL particles. Although lipidation increases ApoA-I proteins stability, all the amyloidogenic variants analyzed show a lower affinity for lipids, both in vitro and in ex vivo mouse serum. Interestingly, the lower efficiency at forming HDL particles is compensated by a higher efficiency at catalysing cholesterol efflux from macrophages. The decreased affinity of ApoA-I amyloidogenic variants for lipids, together with the increased efficiency in the cholesterol efflux process, could explain why, despite the unfavourable lipid profile, patients affected by ApoA-I related amyloidosis do not show a higher CVD risk
Protein-DNA/RNA Interactions: An Overview of Investigation Methods in the -Omics Era
The fields of application of functional proteomics are not limited to the study of protein-protein interactions; they also extend to those involving protein complexes that bind DNA or RNA. These interactions affect fundamental processes such as replication, transcription, and repair in the case of DNA, as well as transport, translation, splicing, and silencing in the case of RNA. Analytical or preparative experimental approaches, both in vivo and in vitro, have been developed to isolate and identify DNA/RNA binding proteins by exploiting the advantage of the affinity shown by these proteins toward a specific oligonucleotide sequence. The present review proposes an overview of the approaches most commonly employed in proteomics applications for the identification of nucleic acid-binding proteins, such as affinity purification (AP) protocols, EMSA, chromatin purification methods, and CRISPR-based chromatin affinity purification, which are generally associated with mass spectrometry methodologies for the unbiased protein identification
Lysines Acetylome and Methylome Profiling of H3 and H4 Histones in Trichostatin A-Treated Stem Cells
Trichostatin A ([R-(E,E)]-7-[4-(dimethylamino) phenyl]-N-hydroxy- 4,6-dimethyl- 7-oxo-2,4-heptadienamide, TSA) affects chromatin state through its potent histone deacetylase inhibitory activity. Interfering with the removal of acetyl groups from lysine residues in histones is one of many epigenetic regulatory processes that control gene expression. Histone deacetylase inhibition drives cells toward the differentiation stage, favoring the activation of specific genes. In this paper, we investigated the effects of TSA on H3 and H4 lysine acetylome and methylome profiling in mice embryonic stem cells (ES14), treated with trichostatin A (TSA) by using a new, untargeted approach, consisting of trypsin-limited proteolysis experiments coupled with MALDI-MS and LC-MS/MS analyses. The method was firstly set up on standard chicken core histones to probe the optimized conditions in terms of enzyme:substrate (E:S) ratio and time of proteolysis and, then, applied to investigate the global variations of the acetylation and methylation state of lysine residues of H3 and H4 histone in the embryonic stem cells (ES14) stimulated by TSA and addressed to differentiation. The proposed strategy was found in its simplicity to be extremely effective in achieving the identification and relative quantification of some of the most significant epigenetic modifications, such as acetylation and lysine methylation. Therefore, we believe that it can be used with equal success in wider studies concerning the characterization of all epigenetic modifications
Dielectric spectroscopy of PP/MWCNT nanocomposites: Relationship with crystalline structure and injection molding condition
In this paper, we study the correlation between the dielectric behavior of polypropylene/multi-walled carbon nanotube (PP/MWCNT) nanocomposites and the morphology with regard to the crystalline structure, nanofiller dispersion and injection molding conditions. As a result, in the range of the percolation threshold the dielectric behavior shifts to a more frequency-independent behavior, as the mold temperature increases. Moreover, the position further from the gate appears as the most conductive. This effect has been associated to a modification of the morphology of the MWCNT clusters induced by both the flow of the molten polymer during the processing phase and the variation of the crystalline structure, which is increasingly constituted by γ-phase as the mold temperature increases. The obtained results allow one to understand the effect of tuning the processing condition in the frequency-dependent electrical behavior of PP/MWCNT injection-molded nanocomposites, which can be successfully exploited for an advanced process/product design
BIOMECHANICAL OPTIMIZATION OF CO2ANGIOGRAPHY
Carbon dioxide (CO2) angiography represents an important technique to overcome most clinical problems related to the use of iodine contrast medium. The recent technologic advancements in the fields of gas injection and image reconstructions made CO2 angiography a very efficient method for clinical evaluation of peripheral cardiovascular system. Despite that, some challenges are still open and a better knowledge of the biomechanical behavior of CO2 and its interactions with blood flowing into the vessels is necessary to optimize this technology and to expand its field of application. This paper presents a quick overview about biomechanical behavior of carbon dioxide during injection, suggesting possible optimization tricks to make CO2 angiography procedures more effective to improve imaging and reduce the patients' radiological dose. Particular attention has been also paid to 3D imaging techniques, which can certainly be opened to the use of carbon dioxide
Unravelling molecular mechanisms in the fluorescence spectra of doxorubicin in aqueous solution by femtosecond fluorescence spectroscopy
International audienceDoxorubicin (DOX) is a potent anti-tumoral agent widely used for cancer therapy. Despite numerous studies, the fluorescence properties of DOX, usually exploited for the characterization of the interaction with biological media, have until now led to controversial interpretations, mainly due to self-association of the drug in aqueous solution. We present here the first femtosecond study of DOX based on measurements with the fluorescence up-conversion technique in combination with time-correlated single photon counting using the same laser source. We provide evidence that fluorescence signals of DOX stem from monomers and dimers. DOX dimerization induces a dramatic decrease in the fluorescence quantum yield from 3.9 × 10−2 to 10−5 associated with the red shift of the fluorescence spectrum by [similar]25 nm. While the fluorescence lifetime of the monomer is 1 ns, the dimer fluorescence is found to decay with a lifetime of about 2 ps. In contrast to monomers, the fluorescence anisotropy of dimers is found to be negative. These experimental observations are consistent with an ultrafast internal conversion (<200 fs) between two exciton states, possibly followed by a charge separation process
Quasi-equilibrium states in thermotropic liquid crystals studied by multiple quantum NMR
We study the nature of the quasiinvariants in nematic 5CB and measure their
relaxation times by encoding the multiple quantum coherences of the states
following the JB pulse pair on two orthogonal bases, Z and X. The experiments
were also performed in powder adamantane at 301 K which is used as a reference
compound having only one dipolar quasiinvariant. We show that the evolution of
the quantum states during the build up of the quasi-equilibrium state in 5CB
prepared under the S condition is similar to the case of adamantane and that
their quasi-equilibrium density operators have the same tensor structure. In
contrast, the second constant of motion, whose explicit operator form is not
known, involves a richer composition of multiple quantum coherences on the X
basis of even order, in consistency with the truncation inherent in its
definition. We exploited the exclusive presence coherences 4, 6, 8, besides 0
and 2 under the W condition to measure the spin-lattice relaxation time T_{W}
accurately, so avoiding experimental difficulties that usually impair dipolar
order relaxation measurement such as Zeeman contamination at high fields, and
also superposition of the different quasiinvariants. This procedure opens the
possibility of measuring the spin-lattice relaxation of a quasiinvariant
independent of the Zeeman and S reservoirs, so incorporating a new relaxation
parameter useful for studying the complex molecular dynamics in mesophases. In
fact, we report the first measurement of T_{W} in a liquid crystal at high
magnetic fields. The comparison of the obtained value with the one
corresponding to a lower field (16 MHz) points out that the relaxation of the
W-order strongly depends on the intensity of the external magnetic field,
similarly to the case of the S reservoir, indicating that the relaxation of the
W-quasiinvariant is also governed by the cooperative molecular motions.Comment: 7 figures. http://www.famaf.unc.edu.ar/series/AFis2005.ht
Recurrent Non-Hodgkin’s lymphoma in the uterine cervix: a case report and a review of the literature
Background. Lymphomas are a heterogeneous group of malignant lymphoproliferative diseases. As primary localization, the most common histological subtype of female genital lymphomas is a Non-Hodgkin Lymphoma (NHL), the diffuse large B-cell type. However cervical relapse of NHL is a very rare condition (0.3%). Case presentation. A 42-year-old Peruvian woman experienced relapse of NHL with uterine localization. She complained at first of abnormal vaginal bleeding and stranguria. The cervical biopsy performed showed a diffuse large B-cell lymphoma in the uterine cervix. The lack of clinical studies on this topic and its rarity make this type of recurrence very difficult to treat. Conclusions. In case of a woman with vaginal bleeding and history of NHL, a disease relapse should always be considered, and a biopsy should be performed to confirm the diagnosis. © 2023, EDRA S.p.A. All rights reserved
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