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1.
Eur J Surg Oncol ; 50(7): 108351, 2024 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-38701582

RESUMO

INTRODUCTION: Neoadjuvant chemotherapy (NAC) has a profound impact on surgical management of breast cancer. For this reason, the Italian Association of Breast Surgeons (ANISC) promoted the third national Consensus Conference on this subject, open to multidisciplinary specialists. MATERIALS AND METHODS: The Consensus Conference was held on-line in November 2022, and after an introductory session with five core-team experts, participants were asked to vote on eleven controversial issues, while results were collected in real-time with a polling system. RESULTS: A total of 164 dedicated specialists from 74 Breast Centers participated. Consensus was reached for only three of the eleven issues, including: 1) the indication to assess the response with Magnetic Resonance Imaging (79 %); 2) the need to re-assess the biological factors of the residual tumor if present (96 %); 3) the possibility of omitting a formal axillary node dissection for cN1 patients if a pathologic Complete Response (pCR) was confirmed with analysis of one or more sentinel lymph nodes (82 %). The majority voted in favor of mapping both the breast and nodal lesions pre-NAC (59 %), and against the omission of sentinel lymph node biopsy in cN0 patients in the case of pathologic or clinical Complete Response (69 %). In cases of cT3/cN1+ tumors with pCR, only 8 % of participants considered appropriate the omission of Post-Mastectomy Radiation Therapy. CONCLUSION: There is still a wide variability in surgical approaches after NAC in the "real world". As NAC is increasingly used, multidisciplinary teams should be attuned to conforming their procedures to the rapid advances in this field.

2.
Eur J Surg Oncol ; 50(2): 107954, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38217946

RESUMO

BACKGROUND: De-escalation of axillary surgery in breast cancer (BC) management began when sentinel lymph node biopsy (SLNB) replaced axillary lymph node dissection (ALND) as standard of care in patients with node-negative BC. The second step consolidated ALND omission in selected subgroups of BC patients with up to two macrometastases and recognized BC molecular and genomic implication in predicting prognosis and planning adjuvant treatment. Outcomes from the recent RxPONDER and monarchE trials have come to challenge the previous cut-off of two SLN in order to inform decisions on systemic therapies for hormone receptor-positive (HR+), human epidermal growth factor receptor type-2 (HER2) negative BC, as the criteria included a cut-off of respectively three and four SLNs. In view of the controversy that this may lift in surgical practice, the Italian National Association of Breast Surgeons (Associazione Nazionale Italiana Senologi Chirurghi, ANISC) reviewed data regarding the latest trials on this topic and proposes an implementation in clinical practice. MATERIAL AND METHODS: We reviewed the available literature offering data on the pathological nodal status of cN0 breast cancer patients. RESULTS: The rates of pN2 status in cN0 patients ranges from 3.5 % to 16 %; pre-surgical diagnostic definition of axillary lymph node status in cN0 patients by ultrasound could be useful to inform about a possible involvement of ≥4 lymph nodes in this specific sub-groups of women. CONCLUSIONS: The Italian National Association of Breast Surgeons (ANISC) considers that for HR + HER2-/cN0-pN1(sn) BC patients undergoing breast conserving treatment the preoperative workup should be optimized for a more detailed assessment of the axilla and the technique of SLNB should be optimized, if considered appropriate by the surgeon, not considering routine ALND always indicated to determine treatment recommendations according to criteria of eligibility to RxPONDER and monarch-E trials.


Assuntos
Neoplasias da Mama , Linfonodo Sentinela , Cirurgiões , Humanos , Feminino , Neoplasias da Mama/patologia , Metástase Linfática/patologia , Excisão de Linfonodo , Biópsia de Linfonodo Sentinela/métodos , Axila/patologia , Itália , Linfonodo Sentinela/patologia
3.
Healthcare (Basel) ; 12(2)2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38275547

RESUMO

BACKGROUND: Measurements of breast morphology are a determinant of the assessment of any surgical procedure, either reconstructive or cosmetic. This study aims to investigate the association between easy anthropometric measurements and values of quality of life assessed in a sample of asymptomatic women. METHODOLOGY: Healthy asymptomatic women were admitted for this study. The following measurements were assessed: height, weight, nipple to sternal notch distance, areola to infra-mammary fold distance (right vs. left), right-left nipple distance. The Breast Q questionnaire (Italian translation V.1, pre-op breast conservation surgery) in the following domains: satisfaction with breasts; psycho-social satisfaction; physical satisfaction; sexual satisfaction, which was used to assess breast-related quality of life. RESULTS: One hundred and forty-five women responded to the breast Q questionnaire. The mean age of the sample was 44.3 years; the medium BMI was 24.1; Spearman correlation coefficients revealed that all the investigated values were negatively correlated to the "satisfaction with breasts" domain. Psychosexual satisfaction was associated with age; BMI; nipple to sternal notch distance. After normalization for age values, we observed that "satisfaction with breast" was, once again, highly correlated to BMI; nipple to sternal notch distance; areola to IMF distance. In all cases, the higher the values, the lower the scores. CONCLUSIONS: Distances between easy relevant anatomical landmarks are representative of patients' breast-related quality of life in a population of asymptomatic women. These findings allow us to identify an ideal anthropometric framework that can be used as a validated surgical endpoint for cosmetic and oncological procedures.

5.
Aesthet Surg J ; 44(5): 491-498, 2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37738139

RESUMO

BACKGROUND: Nipple-sparing mastectomies (NSMs) and implant-based breast reconstructions have evolved from 2-stage reconstructions with tissue expansion and implant exchange to direct-to-implant procedures. In this study, we tested safety and efficacy of polyurethane-based implants according to standard assessment tools. OBJECTIVES: This study aimed to test safety and feasibility of polyurethane-coated implants with standardized assessment employing internationally acknowledged evaluation criteria. METHODS: Cases of NSMs followed by breast reconstruction in 1 stage with immediate prepectoral polyurethane-coated implant placement were retrospectively reviewed. Preoperative characteristics of the population have been collected. Adherence to quality assurance criteria of the Association of Breast Surgery-British Association of Plastic Reconstructive and Aesthetic Surgeons was verified. Complications were assessed with the Clavien Dindo classification, modified for the breast. Rippling, implant rotation, and malposition were also evaluated. RESULTS: Sixty-three consecutive patients underwent 74 NSMs and immediate breast reconstruction with micro polyurethane foam-coated anatomic implants. In 5 cases we had unplanned readmissions with return to the operating room under general anesthesia (6.7%) and implant loss within 3 months from breast reconstruction (5 implants, 6.7%). Postoperative complications according to Clavien Dindo were grade 1 in 6 cases (8.1%), grade 2 in 3 cases (4%), and 3b in 5 cases (6.7%). CONCLUSIONS: Polyurethane-coated implants may prevent rotation and malposition and capsular contracture in the short term. Unplanned readmission rates and implant loss rates in the short term may be slightly higher.See the abstract translated into Hindi, Portuguese, Korean, German, Italian, Arabic, Chinese, and Taiwanese online here: https://doi.org/10.1093/asj/sjad301.


Assuntos
Implante Mamário , Implantes de Mama , Neoplasias da Mama , Mamoplastia , Humanos , Feminino , Implantes de Mama/efeitos adversos , Implante Mamário/efeitos adversos , Implante Mamário/métodos , Estudos Retrospectivos , Poliuretanos , Mamoplastia/efeitos adversos , Mamoplastia/métodos , Neoplasias da Mama/cirurgia
6.
Breast Care (Basel) ; 18(3): 209-212, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37928810

RESUMO

Introduction: Books and papers are the most relevant source of theoretical knowledge for medical education. New technologies of artificial intelligence can be designed to assist in selected educational tasks, such as reading a corpus made up of multiple documents and extracting relevant information in a quantitative way. Methods: Thirty experts were selected transparently using an online public call on the website of the sponsor organization and on its social media. Six books edited or co-edited by members of this panel containing a general knowledge of breast cancer or specific surgical knowledge have been acquired. This collection was used by a team of computer scientists to train an artificial neural network based on a technique called Word2Vec. Results: The corpus of six books contained about 2.2 billion words for 300d vectors. A few tests were performed. We evaluated cosine similarity between different words. Discussion: This work represents an initial attempt to derive formal information from textual corpus. It can be used to perform an augmented reading of the corpus of knowledge available in books and papers as part of a discipline. This can generate new hypothesis and provide an actual estimate of their association within the expert opinions. Word embedding can also be a good tool when used in accruing narrative information from clinical notes, reports, etc., and produce prediction about outcomes. More work is expected in this promising field to generate "real-world evidence."

7.
Biomedicines ; 11(11)2023 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-38002091

RESUMO

The neem tree, Azadirachta indica, belongs to the Meliaceae family, and its use in the treatment of medical disorders from ancient times to the present in the traditional medical practices of Asia, Africa and the Middle East is well-documented. Neem oil, extracted from the seeds of the fruit, is widely used, with promising medicinal benefits. Azadiradione, a principal antioxidant component of the seeds of A. indica, is known to reduce oxidative stress and has anti-inflammatory effects. To directly measure the antioxidant ability of neem oil, we used Rotating Ring Disk Electrode (RRDE) hydrodynamic voltammetry to quantify how it can scavenge superoxide radical anions. The results of these experiments show that neem oil is approximately 26 times stronger than other natural products, such as olive oil, propolis and black seed oil, which were previously measured using this method. Next, computational Density Functional Theory (DFT) methods were used to arrive at a mechanism for the scavenging of superoxide radical anions with azadiradione. Our work indicates that azadiradione is an effective antioxidant and, according to our DFT study, its scavenging of the superoxide radical anion occurs through a reaction mechanism in which azadiradione mimics the antioxidant action of superoxide dismutase (SOD). In this mechanism, analogous to the SOD enzymatic reaction, azadiradione is regenerated, along with the production of two products: hydrogen peroxide and molecular oxygen. This antioxidant process provides an explanation for azadiradione's more general and protective biochemical effects.

8.
Molecules ; 28(22)2023 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-38005258

RESUMO

Photodynamic therapy (PDT) is an anticancer/antibacterial strategy in which photosensitizers (PSs), light, and molecular oxygen generate reactive oxygen species and induce cell death. PDT presents greater selectivity towards tumor cells than conventional chemotherapy; however, PSs have limitations that have prompted the search for new molecules featuring more favorable chemical-physical characteristics. Curcumin and its derivatives have been used in PDT. However, low water solubility, rapid metabolism, interference with other drugs, and low stability limit curcumin use. Chemical modifications have been proposed to improve curcumin activity, and metal-based PSs, especially ruthenium(II) complexes, have attracted considerable attention. This study aimed to characterize six Ru(II)-arene curcuminoids for anticancer and/or antibacterial PDT. The hydrophilicity, photodegradation rates, and singlet oxygen generation of the compounds were evaluated. The photodynamic effects on human colorectal cancer cell lines were also assessed, along with the ability of the compounds to induce ROS production, apoptotic, necrotic, and/or autophagic cell death. Overall, our encouraging results indicate that the Ru(II)-arene curcuminoid derivatives are worthy of further investigation and could represent an interesting option for cancer PDT. Additionally, the lack of significant in vivo toxicity on the larvae of Galleria mellonella is an important finding. Finally, the photoantimicrobial activity of HCurc I against Gram-positive bacteria is indeed promising.


Assuntos
Antineoplásicos , Complexos de Coordenação , Curcumina , Fotoquimioterapia , Rutênio , Humanos , Fármacos Fotossensibilizantes/química , Rutênio/farmacologia , Rutênio/química , Curcumina/farmacologia , Diarileptanoides , Complexos de Coordenação/farmacologia , Complexos de Coordenação/química , Antineoplásicos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico
9.
Int J Mol Sci ; 24(13)2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37445927

RESUMO

The relationship between oxidative stress and inflammation is well known, and exogenous antioxidants, primarily phytochemical natural products, may assist the body's endogenous defense systems in preventing diseases due to excessive inflammation. In this study, we evaluated the antioxidant properties of ethnomedicines from Peru that exhibit anti-inflammatory activity by measuring the superoxide scavenging activity of ethanol extracts of Maytenus octogona aerial parts using hydrodynamic voltammetry at a rotating ring-disk electrode (RRDE). The chemical compositions of these extracts are known and the interactions of three methide-quinone compounds found in Maytenus octogona with caspase-1 were analyzed using computational docking studies. Caspase-1 is a critical enzyme triggered during the activation of the inflammasome and its actions are associated with excessive release of cytokines. The most important amino acid involved in active site caspase-1 inhibition is Arg341 and, through docking calculations, we see that this amino acid is stabilized by interactions with the three potential methide-quinone Maytenus octogona inhibitors, hydroxytingenone, tingenone, and pristimerin. These findings were also confirmed after more rigorous molecular dynamics calculations. It is worth noting that, in these three compounds, the methide-quinone carbonyl oxygen is the preferred hydrogen bond acceptor site, although tingenone's other carbonyl group also shows a similar binding energy preference. The results of these calculations and cyclovoltammetry studies support the effectiveness and use of anti-inflammatory ethnopharmacological ethanol extract of Maytenus octogona (L'Héritier) DC.


Assuntos
Maytenus , Superóxidos , Maytenus/química , Caspase 1 , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Antioxidantes/farmacologia , Quinonas , Anti-Inflamatórios/farmacologia , Inflamação , Etanol
10.
Eur J Surg Oncol ; 49(11): 106988, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37500311

RESUMO

This study reports on feasibility and applicability of totally autologous primary breast reconstructions based on TDAP flaps using a standard set of internationally approved reporting scales. We reviewed 15 cases in patients with a good donor area in the back not suitable for implant or free flaps reconstructions. Complications according to Clavien Dindo were: 1 Grade 1 (seroma in the back). The ABS-BAPRAS quality assurance indicators 10, 11, and 12 were entirely fulfilled. No pedicled flap loss occurred; no unplanned return to theatre and no unplanned readmission within 3 months. Breast-related quality of life values are reported at 3 months and one year in four domains of the BREAST Q v. 2.0 (breast reconstruction post-op questionnaire). At 1 year the mean Q-score for satisfaction with breast was 70.5, for psychosocial well-being was 72.3; for sexual well-being was 58.8; for physical well-being (chest wall) was 70.60. The TDAP based totally autologous breast reconstruction reported to be a feasible and safe alternative to implant based or free flaps reconstructions according to consolidate international outcome reporting measures.


Assuntos
Neoplasias da Mama , Mamoplastia , Retalho Perfurante , Humanos , Feminino , Estudos de Viabilidade , Qualidade de Vida , Artérias , Neoplasias da Mama/cirurgia
11.
J Acoust Soc Am ; 153(3): 1934, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-37002078

RESUMO

The echolocation clicks of free-ranging Indo-Pacific finless porpoises (IPFPs, Neophocaena phocaenoides) have been rarely studied in the wild. This paper aims at describing the echolocation-click characteristics of IPFPs and examining whether IPFPs adapt their sonar system to the habitats in Hainan waters, China. The echolocation clicks were recorded using a 13 elements star-shaped array of hydrophones. A total of 65 on-axis clicks were identified and analyzed. IPFPs use echolocation clicks with a source level (SL) of 158 ± 9 dB re: 1 µPa peak-peak, mean peak, and centroid frequency of 134 ± 3 kHz, -3 dB bandwidth of 14 ± 2 kHz and produce at inter-click intervals of 104 ± 51 ms. The results relative to other porpoises show that finless porpoises in Hainan waters produce clicks with moderate SLs and high peak frequency. These results could be useful in detecting the presence and estimating the density of IPFPs during passive acoustic monitoring in the study area and serve to shed light on the interpopulation variation of click characteristics of finless porpoises as well.


Assuntos
Ecolocação , Toninhas , Animais , Som , China
12.
Antioxidants (Basel) ; 12(3)2023 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-36978853

RESUMO

Black cumin seeds and seed oil have long been used in traditional foods and medicine in South Asian, Middle Eastern and Mediterranean countries and are valuable flavor ingredients. An important ingredient of black cumin is the small molecule thymoquinone (TQ), which manifests low toxicity and potential therapeutic activity against a wide number of diseases including diabetes, cancer and neurodegenerative disorders. In this study, the antioxidant activities of black seed oil, TQ and a related molecule found in black cumin, thymohydroquinone (THQ), were measured using a direct electrochemical method to experimentally evaluate their superoxide scavenging action. TQ and the black seed oil showed good superoxide scavenging ability, while THQ did not. Density Functional Theory (DFT) computational methods were applied to arrive at a chemical mechanism describing these results, and confirmed the experimental Rotating Ring Disk Electrode (RRDE) findings that superoxide oxidation to O2 by TQ is feasible, in contrast with THQ, which does not scavenge superoxide. Additionally, a thorough inquiry into the unusual cyclic voltammetry pattern exhibited by TQ was studied and was associated with formation of a 1:1 TQ-superoxide radical species, [TQ-O2]-•. DFT calculations reveal this radical species to be involved in the π-π mechanism describing TQ reactivity with superoxide. The crystal structures of TQ and THQ were analyzed, and the experimental data reveal the presence of stacking intermolecular interactions that can be associated with formation of the radical species, [TQ-O2]-•. All three of these methods were essential for us to arrive at a chemical mechanism that explains TQ antioxidant activity, that incorporates intermolecular features found in the crystal structure and which correlates with the measured superoxide scavenging activity.

13.
Int J Mol Sci ; 24(4)2023 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-36835226

RESUMO

Isoflavones are plant-derived natural products commonly found in legumes that show a large spectrum of biomedical activities. A common antidiabetic remedy in traditional Chinese medicine, Astragalus trimestris L. contains the isoflavone formononetin (FMNT). Literature reports show that FMNT can increase insulin sensitivity and potentially target the peroxisome proliferator-activated receptor gamma, PPARγ, as a partial agonist. PPARγ is highly relevant for diabetes control and plays a major role in Type 2 diabetes mellitus development. In this study, we evaluate the biological role of FMNT, and three related isoflavones, genistein, daidzein and biochanin A, using several computational and experimental procedures. Our results reveal the FMNT X-ray crystal structure has strong intermolecular hydrogen bonding and stacking interactions which are useful for antioxidant action. Cyclovoltammetry rotating ring disk electrode (RRDE) measurements show that all four isoflavones behave in a similar manner when scavenging the superoxide radical. DFT calculations conclude that antioxidant activity is based on the familiar superoxide σ-scavenging mode involving hydrogen capture of ring-A H7(hydroxyl) as well as the π-π (polyphenol-superoxide) scavenging activity. These results suggest the possibility of their mimicking superoxide dismutase (SOD) action and help explain the ability of natural polyphenols to assist in lowering superoxide concentrations. The SOD metalloenzymes all dismutate O2•- to H2O2 plus O2 through metal ion redox chemistry whereas these polyphenolic compounds do so through suitable hydrogen bonding and stacking intermolecular interactions. Additionally, docking calculations suggest FMNT can be a partial agonist of the PPARγ domain. Overall, our work confirms the efficacy in combining multidisciplinary approaches to provide insight into the mechanism of action of small molecule polyphenol antioxidants. Our findings promote the further exploration of other natural products, including those known to be effective in traditional Chinese medicine for potential drug design in diabetes research.


Assuntos
Produtos Biológicos , Isoflavonas , Superóxido Dismutase , Humanos , Antioxidantes/química , Produtos Biológicos/química , Diabetes Mellitus Tipo 2 , Peróxido de Hidrogênio , Isoflavonas/química , PPAR gama/química , Superóxido Dismutase/química , Superóxidos/química
15.
Environ Pollut ; 316(Pt 2): 120527, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36334777

RESUMO

Marine litter pollution, particularly plastics pollution, is an increasing global concern. While various studies have contributed useful information on this topic, there has been a scarcity of data on floating marine macro-litter (FMML) in poorly monitored areas such as the South China Sea (SCS). This paper describes a large-scale FMML assessment research in the northern SCS. Our data indicated the ubiquitous presence, abundant quantity, spatiotemporal variability, complex composition, and potential sources of FMML in the investigated region during boreal spring-summer periods over multiple years. According to observer-based records, the average FMML density was estimated to be 131.0 ± 91.8 items/km2 (mean ± SD), with anthropogenic FMML density of 118.7 ± 86.2 items/km2. Anthropogenic and natural items accounted for 90.6% and 5.5% of the total, respectively. Plastics (72.0%) and styrofoam (9.3%) dominated the recorded items. The great majority of items (92.1%) were characterized by small size of ≤20 cm. Labels of plastic bottle/packaging litter indicated that identifiable sources included surrounding countries of the SCS. Fishing activities were recognized as key sources of FMML, with 15.3% of FMML items likely being fishing-related. Globally, known estimates of FMML densities could vary from 0.002 to 578 items/km2, with plastics accounting for 34.8-99.0%. Therefore, marine pollution from anthropogenic FMML in our investigated area ranked at a medium-to-high level around the globe. To conclude, this study demonstrated that the SCS is one of the world's hotspot areas with FMML pollution and sheds light on marine litter pollution, especially plastics pollution, in this intensively human-exploited but poorly monitored region. In future research, FMML pollution in other sections of SCS and possible negative impacts of FMML on marine ecosystems and megafauna should be further examined.


Assuntos
Monitoramento Ambiental , Resíduos , Humanos , Resíduos/análise , Ecossistema , Plásticos , Poluição da Água/análise , Mar Mediterrâneo
16.
Pharmaceuticals (Basel) ; 17(1)2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-38256900

RESUMO

Pimpinella anisum L., or anise, is a plant that, besides its nutritional value, has been used in traditional medical practices and described in many cultures in the Mediterranean region. A possible reason for anise's therapeutic value is that it contains coumarins, which are known to have many biomedical and antioxidant properties. HPLC analysis in our laboratory of the anise extract shows the presence of the coumarin esculetin. We used a hydrodynamic voltammetry rotating ring-disk electrode (RRDE) method to measure the superoxide scavenging abilities of anise seeds and esculetin, which has marked scavenging activity. A related coumarin, 4-methyl-esculetin, also showed strong antioxidant activity as measured by RRDE. Moreover, this study includes the X-ray crystal structure of esculetin and 4-methyl-esculetin, which reveal the H-bond and the stacking intermolecular interactions of the two coumarins. Coordinates of esculetin crystal structure were used to perform a DFT study to arrive at the mechanism of superoxide scavenging. Besides performing a H(hydroxyl) abstraction in esculetin position 6 by superoxide, the scavenging also includes the presence of a second superoxide radical in a π-π approach. Both rings of esculetin were explored for this attack, but only the pyrone ring was effective. As a result, one product of esculetin scavenging is H2O2 formation, while the second superoxide remains π-π trapped within the pyrone ring to form an esculetin-η-O2 complex. Comparison with other coumarins shows that subtle structural differences in the coumarin framework can imply marked differences in scavenging. For instance, when the catechol moiety of esculetin (position 6,7) is shifted to position 7,8 in 4-methyl-7,8-dihydroxy coumarin, that coumarin shows a superoxide dismutase action, which, beside H2O2 formation, includes the formation and elimination of a molecule of O2. This is in contrast with the products formed through esculetin superoxide scavenging, where a second added superoxide remains trapped, and forms an esculetin-η-O2 complex.

17.
Curr Issues Mol Biol ; 44(11): 5209-5220, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36354666

RESUMO

Polyphenols are valuable natural antioxidants present in our diet that likely mitigate aging effects, neurodegenerative conditions, and other diseases. However, because of their poor absorption in the gut and consequent low concentration in biological fluids (µM range), reservations about polyphenol antioxidant efficiency have been raised. In this review, it is shown that after scavenging superoxide radicals, coumarin, chalcone, and flavonoid polyphenols can reform themselves, becoming ready for additional cycles of scavenging, similar to the catalytic cycle in superoxide dismutase (SOD) action. The π-π interaction between one polyphenol ring and superoxide is associated with oxidation of the latter due to transfer of its unpaired electron to a polyphenolic aromatic ring, and consequent formation of a molecule of O2 (one product of SOD action). Mechanistically, it is very difficult to establish if this π-π interaction proceeds before or after the most common mode of scavenging superoxide, e.g., abstraction of an aromatic polyphenol H(hydroxyl), which then is used to form H2O2 (the other molecule produced by SOD action). At the end of this cycle of superoxide scavenging, 4-methyl-7,8-di-hydroxy-coumarin and the flavonoid galangin reform themselves. An alternative mechanistic pathway by galangin forms the η-(H2O2)-galangin-η-O2 complex that includes additional H2O2 and O2 molecules. Another mode of action is seen with the chalcone butein, in which the polyphenol system incorporates a molecule of O2, e.g., a η-O2-butein complex is formed, ready for additional scavenging. Of the several families of polyphenols analyzed in this review, only butein was able to circumvent an initial π-π interaction, directing the superoxide towards H(hydroxyl) in position 4, e.g., acting as a typical polyphenol scavenger of superoxide. This fact did not impede an additional superoxide to later react with the aromatic ring in π-π fashion. It is concluded that by mimicking SOD enzyme action, the low concentration of polyphenols in biological fluids is not a limiting factor for effective scavenging of superoxide.

18.
Front Endocrinol (Lausanne) ; 13: 961744, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36213288

RESUMO

Thyroid hormones, T3 (triiodothyronine) and T4 (thyroxine), induce a variety of long-term effects on important physiological functions, ranging from development and growth to metabolism regulation, by interacting with specific nuclear or cytosolic receptors. Extranuclear or nongenomic effects of thyroid hormones are mediated by plasma membrane or cytoplasmic receptors, mainly by αvß3 integrin, and are independent of protein synthesis. A wide variety of nongenomic effects have now been recognized to be elicited through the binding of thyroid hormones to this receptor, which is mainly involved in angiogenesis, as well as in cell cancer proliferation. Several signal transduction pathways are modulated by thyroid hormone binding to αvß3 integrin: protein kinase C, protein kinase A, Src, or mitogen-activated kinases. Thyroid hormone-activated nongenomic effects are also involved in the regulation of Na+-dependent transport systems, such as glucose uptake, Na+/K+-ATPase, Na+/H+ exchanger, and amino acid transport System A. Of note, the modulation of these transport systems is cell-type and developmental stage-dependent. In particular, dysregulation of Na+/K+-ATPase activity is involved in several pathological situations, from viral infection to cancer. Therefore, this transport system represents a promising pharmacological tool in these pathologies.


Assuntos
Neoplasias , Tri-Iodotironina , Adenosina Trifosfatases/metabolismo , Sistema A de Transporte de Aminoácidos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Glucose , Humanos , Integrinas/metabolismo , Mitógenos , Neoplasias/metabolismo , Proteína Quinase C/metabolismo , Hormônios Tireóideos/metabolismo , Tiroxina/metabolismo , Tri-Iodotironina/fisiologia
19.
Int J Mol Sci ; 23(17)2022 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-36077005

RESUMO

The unprecedented COVID-19 pandemic showed up during the latter part of 2019 in Wuhan, China [...].


Assuntos
COVID-19 , China/epidemiologia , Humanos , Pandemias , SARS-CoV-2
20.
PLoS One ; 17(5): e0267624, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35584109

RESUMO

Propolis is produced by honeybees and used to seal their hives for defensive purposes and has been used in ethnopharmacology since ancient times. It is a lipophilic material containing a large collection of naturally produced plant organic molecules, including flavonoids. The flavonoid galangin is consistently found in propolis, independent of the hive geographical location and its X-ray crystal and molecular structure is reported. The antioxidant scavenging of superoxide by galangin and propolis is here presented. Using a cyclic voltammetry technique developed in our lab, we show that galangin is an excellent scavenger of the superoxide radical, perhaps even better than quercetin. Our results show that galangin displays a Superoxide Dismutase (SOD) function. This is described experimentally and theoretically (DFT). Two modes of scavenging superoxide are seen for galangin: (1) superoxide radical extraction of H atom from the hydroxyl moieties located in position 3 and 5 of galangin, which are also associated with proton incorporation defining the SOD action; (2) π-π interaction among several superoxide radicals and the galangin polyphenol ring that evolve towards release of O2 and H2O2. We describe these two actions separately as their relative sequence, and/or combination, cannot be defined; all these processes are thermodynamically spontaneous, or subjected to mild barriers.


Assuntos
Própole , Animais , Antioxidantes/farmacologia , Flavonoides/farmacologia , Hidrodinâmica , Peróxido de Hidrogênio , Própole/química , Superóxido Dismutase , Superóxidos , Raios X
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