18F-FDG PET/MRI Imaging in a Preclinical Rat Model of Cardiorenal Syndrome-An Exploratory Study.

Cardiorenal syndrome (CRS) denotes the bidirectional interaction of chronic kidney disease and heart failure with an adverse prognosis but with a limited understanding of its pathogenesis. This study correlates biochemical blood markers, histopathological and immunohistochemistry features, and 2-deoxy-2-fluoro-D-glucose positron emission tomography (18F-FDG PET) metabolic data in low-dose doxorubicin-induced heart failure, cardiorenal syndrome, and renocardiac syndrome induced on Wistar male rats. To our knowledge, this is the first study that investigates the underlying mechanisms for CRS progression in rats using 18F-FDG PET. Clinical, metabolic cage monitoring, biochemistry, histopathology, and immunohistochemistry combined with PET/MRI (magnetic resonance imaging) data acquisition at distinct points in the disease progression were employed for this study in order to elucidate the available evidence of organ crosstalk between the heart and kidneys. In our CRS model, we found that chronic treatment with low-dose doxorubicin followed by acute 5/6 nephrectomy incurred the highest mortality among the study groups, while the model for renocardiac syndrome resulted in moderate-to-high mortality. 18F-FDG PET imaging evidenced the doxorubicin cardiotoxicity with vascular alterations, normal kidney development damage, and impaired function. Given the fact that standard clinical markers were insensitive to early renal injury, we believe that the decreasing values of the 18F-FDG PET-derived renal marker across the groups and, compared with their age-matched controls, along with the uniform distribution seen in healthy developing rats, could have a potential diagnostic and prognostic yield in cardiorenal syndrome.

The perception of the educational environment in multinational students from a dental medicine faculty in Romania.

INTRODUCTION: Dental education comes with important challenges for the faculties as well as for the students. Its evolving nature leads to the constant adoption of new practices and techniques. Thus, the learning environment is in continuous development. This study aimed to describe a sample of senior undergraduate student's perceptions of their learning environment. METHODS: Students (both Romanian and international) enrolled in the 6th year at the Faculty of Dental Medicine from a Romanian University completed the Dundee Ready Education Environment Measure (DREEM). The scale measures students' perceptions of the education environment using five domains: Learning, Teaching, Academic self-perception, Atmosphere and Social self-perception. Data were analysed using descriptive statistics, non-parametric and univariate statistics for group comparison. RESULTS: Participants (N = 259, Romanian = 111, International = 148) had a good perception of their learning environment, with a total DREEM score of 117.82 out of 200. Still, they had a lower score in the areas of Academic and Social self-perception. The international students had more negative perceptions of the learning environment compared to the Romanian ones. The French-speaking students had the lowest scores on most of the areas. CONCLUSIONS: Although the perception of medical dentistry education is generally good, international students are not as satisfied with the learning environment. The students' experiences could be improved by providing them with more social support. Also, it is important to address the needs of international students in order to create a more satisfying environment for them.

ColBioS-FlavRC: a collection of bioselective flavonoids and related compounds filtered from high-throughput screening outcomes.

Flavonoids, the vastest class of natural polyphenols, are extensively investigated for their multiple benefits on human health. Due to their physicochemical or biological properties, many representatives are considered to exhibit low selectivity among various protein targets or to plague high-throughput screening (HTS) outcomes. The aim of this study is to highlight reliable, bioselective compounds sharing flavonoidic scaffolds in HTS experiments. A filtering scheme was applied to remove undesired flavonoids (and related compounds) from confirmatory PubChem bioassays. A number of 433 compounds addressing various protein targets form the core of the collection of bioselective flavonoids and related compounds (ColBioS-FlavRC). With an additional set of 2908 inactive related compounds, ColBioS-FlavRC offers the grounds for method optimization and validation. We exemplified the use of ColBioS-FlavRC by pharmacophore modeling, subsequently (externally) validated for virtual screening purposes. The early enrichment capabilities of the pharmacophore hypotheses were measured by means of the median exponential retriever operating curve enrichment (MeROCE), a suited metric in comparative evaluations of virtual screening methods. ColBioS-FlavRC is available in the Supporting Information and is freely accessible for further studies.

Retrospective group fusion similarity search based on eROCE evaluation metric.

In this study, a simple evaluation metric, denoted as eROCE was proposed to measure the early enrichment of predictive methods. We demonstrated the superior robustness of eROCE compared to other known metrics throughout several active to inactive ratios ranging from 1:10 to 1:1000. Group fusion similarity search was investigated by varying 16 similarity coefficients, five molecular representations (binary and non-binary) and two group fusion rules using two reference structure set sizes. We used a dataset of 3478 actives and 43,938 inactive molecules and the enrichment was analyzed by means of eROCE. This retrospective study provides optimal similarity search parameters in the case of ALDH1A1 inhibitors.

A New Method for Tungsten Oxide Nanopowder Deposition on Carbon-Fiber-Reinforced Polymer Composites for X-ray Attenuation.

A new method for the synthesis and deposition of tungsten oxide nanopowders directly on the surface of a carbon-fiber-reinforced polymer composite (CFRP) is presented. The CFRP was chosen because this material has very good thermal and mechanical properties and chemical resistance. Also, CFRPs have low melting points and are transparent under ionized radiation. The synthesis is based on the direct interaction between high-power-density microwaves and metallic wires to generate a high-temperature plasma in an oxygen-containing atmosphere, which afterward condenses as metallic oxide nanoparticles on the CFRP. During microwave discharge, the value of the electronic temperature of the plasma, estimated from Boltzmann plots, reached up to 4 eV, and tungsten oxide crystals with a size between 5 nm and 100 nm were obtained. Transmission electron microscopy (TEM) analysis of the tungsten oxide nanoparticles showed they were single crystals without any extended defects. Scanning electron microscopy (SEM) analysis showed that the surface of the CFRP sample does not degrade during microwave plasma deposition. The X-ray attenuation of CFRP samples covered with tungsten oxide nanopowder layers of 2 µm and 21 µm thickness was measured. The X-ray attenuation analysis indicated that the thin film with 2 µm thickness attenuated 10% of the photon flux with 20 to 29 KeV of energy, while the sample with 21 µm thickness attenuated 60% of the photon flux.

The Effects Induced by Microwave Field upon Tungsten Wires of Different Diameters.

The effects induced by microwave field upon tungsten wires of different diameters were investigated. Tungsten wires with 0.5 and 1.0 mm diameters were placed in the focal point of a single-mode cylindrical cavity linked to a microwave generator and exposed to microwave field in ambient air. The experimental results showed that the 0.5 mm diameter wire was completely vaporized due to microwaves strong absorption, while the wire with 1 mm diameter was not ignited. During the interaction between microwaves and tungsten wire with 0.5 mm diameter, a plasma with a high electronic excitation temperature was obtained. The theoretical analysis of the experiment showed that the voltage generated by metallic wires in interaction with microwaves depended on their electric resistance in AC and the power of the microwave field. The physical parameters and dimension of the metallic wire play a crucial role in the ignition process of the plasma by the microwave field. This new and simple method to generate a high-temperature plasma from a metallic wire could have many applications, especially in metal oxides synthesis, metal coatings, or thin film deposition.

Primary cutaneous mantle cell lymphoma: a case report.

Primary cutaneous mantle cell lymphoma (MCL) is a rare cutaneous proliferation of naive pregerminal CD-5 positive B cells in the skin with no extracutaneous involvement. Overexpression of cyclin D1 is pathognomonic of this condition, and surgery and radiation therapy are the most common therapeutic options. In this case, we describe the clinical, histopathological, immunohistochemical, and molecular characteristics of a new case of primary cutaneous MCL.

Determination of DNA synthesis, estrogen receptors, and carcinoembryonic antigen in isolated cellular subpopulations of human breast cancer.

Primary breast adenocarcinomas obtained from ten patients were enzymatically digested using collagenase (1 mg/ml), hyaluronidase (1 mg/ml), elastase (0.1 mg/ml) and DNAse (0.2 mg/ml). The tumor cells were labeled with 3H-thymidine and, in some cases, with 3H-estradiol. The isolated cells were submitted successively to a Ficoll-Hypaque and a bovine serum albumin gradient, from which 12 fractions were obtained. In each fraction, several characteristics were determined: carcinoembryonic antigen (CEA), thymidine (dThd) incorporation, and estrogen receptors (ER). Three main cellular subpopulations were characterized: An intermediate density subpopulation (1.046-1.054 g/ml), in which the proliferating cells are concentrated. In this subpopulation a small number of CEA-positive cells are present, but ER containing cells are virtually absent. A high-density, small cell subpopulation that concentrates most of the ER-containing cells. This subpopulation lacks proliferating cells, but CEA-containing cells are abundant. A low-density subpopulation, lacking proliferating cells and with scarce ER-positive cells, although CEA-positive cells are frequent. These findings strongly suggest that proliferating cells lack ER.

DNA synthesis in estrogen receptor-positive human breast cancer takes place preferentially in estrogen receptor-negative cells.

The primary breast tumors of 27 patients were analyzed for the expression of estrogen receptors (ER) and DNA synthesis. Seventeen tumors were ER-positive, and the simultaneous expression of ER and DNA synthesis could be analyzed in 14 ER-positive tumors. DNA synthesis was measured through the thymidine labeling index (TLI). ER expression was detected by immunohistochemistry with monoclonal antibodies. In these tumors, 38.6% +/- 13.1% of the cells were ER-positive (average TLI = 0.60% +/- 0.70%), as opposed to the presence of 61.4% +/- 13.1% of ER-negative cells (average TLI = 0.65% +/- 0.53%). In 12 of 14 tumors, both ER-positive and ER-negative cells were found to be engaged in DNA synthesis, whereas in two tumors only ER-negative cells were synthesizing DNA. On the basis of the TLI and the proportion of ER-negative and ER-positive cells in the total population, it is suggested that the ER-positive and ER-negative compartments are interrelated in most tumors. In five tumors, the ER-negative compartment would be a precursor of the ER-positive segment, whereas in six tumors the ER-positive segment appears to be a precursor of the ER-negative one. In three tumors, no evidence of an interrelationship between both segments could be found. In the 14 tumors analyzed, it also was found that 69.1% +/- 21.3% of the DNA-synthesizing cells were ER-negative; this probably accounts for the temporary remissions observed after hormonal treatment in breast cancer.

The expression of progesterone receptors coincides with an arrest of DNA synthesis in human breast cancer.

Two main models to account for the heterogeneous expression of estrogen receptors (ER) and progesterone receptors (PR) in human breast cancer have been proposed: the clonal model and the stem cell model. The authors previously provided evidence supporting the stem cell model since it was found that most of the proliferating cells in ER-positive (ER+) human breast cancer lack ER and that the ER-negative (ER-) and ER+ subpopulations are interrelated. The authors have analyzed in eighteen ER+/PR+ primary breast tumors the simultaneous expression of ER or PR (by immunohistochemistry) and DNA synthesis (by autoradiography) after 30 minutes of 3H-thymidine incorporation. The authors demonstrated that: (1) the average numbers of ER+ and PR+ cells were similar (36.8 +/- 10.7% and 39.3 +/- 17.6%, respectively); (2) The thymidine-labeling indexes of the ER+, ER-, PR+, and PR- subpopulations were 0.53 +/- 0.69%, 0.74 +/- 0.49%, 0.21 +/- 0.21 and 0.94 +/- 0.54%, respectively; and (3) 75.2% of the DNA-synthesizing cells were ER-, and 88.8% of them were PR-. The authors conclude that the cellular subpopulations expressing ER and PR were not identical, and the expression of PR was associated with a lower rate of cellular proliferation than was ER expression.