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1.
Am J Hematol ; 99(4): 586-595, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38317420

RESUMO

Blinatumomab is a BiTE® (bispecific T-cell engager) molecule that redirects CD3+ T-cells to engage and lyse CD19+ target cells. Here we demonstrate that subcutaneous (SC) blinatumomab can provide high efficacy and greater convenience of administration. In the expansion phase of a multi-institutional phase 1b trial (ClinicalTrials.gov, NCT04521231), heavily pretreated adults with relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL) received SC blinatumomab at two doses: (1) 250 µg once daily (QD) for week 1 and 500 µg three times weekly (TIW) thereafter (250 µg/500 µg) or (2) 500 µg QD for week 1 and 1000 µg TIW thereafter (500 µg/1000 µg). The primary endpoint was complete remission/complete remission with partial hematologic recovery (CR/CRh) within two cycles. At the data cutoff of September 15, 2023, 29 patients were treated: 14 at the 250 µg/500 µg dose and 13 at 500 µg/1000 µg dose. Data from two ineligible patients were excluded. At the end of two cycles, 12 of 14 patients (85.7%) from the 250 µg/500 µg dose achieved CR/CRh of which nine patients (75.0%) were negative for measurable residual disease (MRD; <10-4 leukemic blasts). At the 500 µg/1000 µg dose, 12 of 13 patients (92.3%) achieved CR/CRh; all 12 patients (100.0%) were MRD-negative. No treatment-related grade 4 cytokine release syndrome (CRS) or neurologic events (NEs) were reported. SC injections were well tolerated and all treatment-related grade 3 CRS and NEs responded to standard-of-care management, interruption, or discontinuation. Treatment with SC blinatumomab resulted in high efficacy, with high MRD-negativity rates and acceptable safety profile in heavily pretreated adults with R/R B-ALL.


Assuntos
Anticorpos Biespecíficos , Antineoplásicos , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Adulto , Humanos , Indução de Remissão , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico , Anticorpos Biespecíficos/efeitos adversos , Linfoma de Células B/tratamento farmacológico , Resposta Patológica Completa , Doença Aguda , Neoplasia Residual , Leucemia-Linfoma Linfoblástico de Células Precursoras B/tratamento farmacológico , Antineoplásicos/efeitos adversos
2.
Hell J Nucl Med ; 26(3): 194-200, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38085835

RESUMO

OBJECTIVE: Vitamin D (VitD) plays various roles, promotes musculoskeletal health, maintains parathyroid hormone levels and supports the immune processes. Vitamin D deficiency is common among cancer patients including thyroid cancer. Since some data indicate that preoperative VitD levels in cancer patients correlate with the further prognosis of the disease. Therefore, it is worthwhile to investigate this in the most common cancer of the thyroid gland, papillary thyroid cancer (PTC). The aim of this study was to evaluate serum VitD levels in patients with PTC concerning age, gender, body mass index (BMI), cancer stage, thyroid hormone levels, thyroglobulin concentration and the efficiency of VitD3 supplementation in these patients. SUBJECTS AND METHODS: Our cross-sectional study included 105 patients, and 34 healthy subjects in the control group. After 12 weeks of VitD3 supplementation (insufficient patients received1000IJ/day, deficient patients 2000IJ/day, severe deficient patient 5000IJ/day) along with the lifestyle and dietary management, the response was evaluated according to the personal characteristics, levels of VitD, free thyroxine (FT4), freetriiodothyronine (FT3) hormones and thyroglobulin (TG). RESULTS: The responders whose median age was 61-year-old, were mostly women (94%), with BMI below 23.7kg/m3, which indicates that most of the patients were normally nourished. 70% of patients were in the first stage of PTC, 76% had a vitamin D deficiency, while musculoskeletal disorders were present in 30% patients. VitD supplementation improved serum VitD status, FT3 discretely elevated and the TG levels significantly decreased in our PTC patients. CONCLUSION: It should be noted that VitD deficiency is presented in 70% of patients with PTC in our study sample. Dietary recommendation applied as lifestyle changes along with oral VitD3 supplementation, corrected VitD status to the recommended serum level. Although the data from our study is not sufficient to evaluate the VitD level as a prognostic factor for cancer, we have shown that it is necessary to examine its level along with an individual dietary approach for each patient with PTC.


Assuntos
Neoplasias da Glândula Tireoide , Deficiência de Vitamina D , Humanos , Feminino , Pessoa de Meia-Idade , Masculino , Colecalciferol/uso terapêutico , Tireoglobulina , Câncer Papilífero da Tireoide , Estudos Transversais , Vitamina D , Deficiência de Vitamina D/complicações , Neoplasias da Glândula Tireoide/complicações , Suplementos Nutricionais
3.
Acta Pharm ; 73(4): 601-616, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-38147483

RESUMO

Olive leaves as a main byproduct of olive oil and fruit industry are a valuable source of phytochemicals such as polyphenols, with multiple biomedical effects. Apart from leaves, olive branches and stems make up a significant amount of olive waste. It is well known that the drying process and long-term storage affect the stability and concentration of polyphenols present in raw materials. For that matter, two different means of storing olive waste, at room temperature and +4 °C, were compared by determining the content of the polyphenol oleuropein (OLE) in olive leaf, branch, and stem extracts (LE, BE, and SE) by HPLC-DAD method. Total phenols (TPC), o-diphenols (o-DPC), and total flavonoids (TFC) content in extracts were assessed by UV-Vis measurements. LE prepared from leaves stored at +4 °C had the highest OLE content, 30.7 mg g-1 of dry extract (DE). SE from stems stored at +4 °C was the richest in TPC and TFC (193 mg GAE/g DE and 82.9 mg CE/g DE, respectively), due to the higher purity of the extract. The biological activity of extracts was determined on cervical cancer (HeLa), melanoma (A375), metastatic melanoma (A375M) tumor cell lines, and on spontaneously immortalized cell line of keratinocytes (HaCaT), using the MTT assay. The data show that all extracts had a similar dose-dependent effect on cell viability in HeLa cells, while the effect of LE on melanoma A375 and A375M, and HaCaT cells was cell-line dependent.


Assuntos
Melanoma , Olea , Neoplasias do Colo do Útero , Feminino , Humanos , Melanoma/tratamento farmacológico , Células HeLa , Iridoides/farmacologia , Iridoides/química , Polifenóis/farmacologia , Olea/química , Antioxidantes/análise , Folhas de Planta/química , Extratos Vegetais/química
4.
Chem Biol Interact ; 386: 110772, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37898285

RESUMO

Having continued our recent study on the synthesis and DNase I inhibition of several monosquaramides, two new chloro-substituted pyridine squaramates were synthesized and their structure was identified by X-ray. Their inhibitory properties towards deoxyribonuclease I (DNase I) and xanthine oxidase (XO) were evaluated in vitro. 3-(((6-Chloropyridin-3-yl)methyl)amino)-4-ethoxycyclobut-3-ene-1,2-dione (compound 3a) inhibited DNase I with an IC50 value of 43.82 ± 6.51 µM, thus standing out as one of the most potent small organic DNase I inhibitors tested to date. No cytotoxicity to human tumor cell lines (HL-60, MDA-MB-231 and MCF-7) was observed for the tested compounds. In order to investigate the drug-likeness of the squaramates, the ADME profile and pharmacokinetic properties were evaluated. Molecular docking was performed to reveal the binding mode of the studied compounds on DNase I.


Assuntos
Desoxirribonuclease I , Piridinas , Humanos , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Linhagem Celular Tumoral , Piridinas/farmacologia , Desoxirribonuclease I/metabolismo , Estrutura Molecular , Inibidores Enzimáticos/química
5.
Molecules ; 28(9)2023 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-37175156

RESUMO

This review article describes studies published over the past five years on the combination of polyphenols, which are the most studied in the field of anticancer effects (curcumin, quercetin, resveratrol, epigallocatechin gallate, and apigenin) and chemotherapeutics such as cisplatin, 5-fluorouracil, oxaliplatin, paclitaxel, etc. According to WHO data, research has been limited to five cancers with the highest morbidity rate (lung, colorectal, liver, gastric, and breast cancer). A systematic review of articles published in the past five years (from January 2018 to January 2023) was carried out with the help of all Web of Science databases and the available base of clinical studies. Based on the preclinical studies presented in this review, polyphenols can enhance drug efficacy and reduce chemoresistance through different molecular mechanisms. Considering the large number of studies, curcumin could be a molecule in future chemotherapy cocktails. One of the main problems in clinical research is related to the limited bioavailability of most polyphenols. The design of a new co-delivery system for drugs and polyphenols is essential for future clinical research. Some polyphenols work in synergy with chemotherapeutic drugs, but some polyphenols can act antagonistically, so caution is always required.


Assuntos
Curcumina , Polifenóis , Polifenóis/uso terapêutico , Curcumina/farmacologia , Curcumina/uso terapêutico , Resveratrol , Antioxidantes , Quimioterapia Combinada
6.
Pediatr Blood Cancer ; : e30435, 2023 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-37246348

RESUMO

We analyzed changes in laboratory parameters, including blood counts, liver enzymes, inflammation and coagulation markers, and cytokines, from 70 blinatumomab-treated pediatric patients (NCT01471782). Overall, trends were consistent in responders and nonresponders. Platelets and lymphocytes peaked on day (D) 10 in cycle 1 and returned to baseline on D42 and D29, respectively. Neutrophils peaked on D2 and returned to baseline on D42. Alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, and bilirubin peaked on D17, reversing to baseline on D29; total protein levels were constant. These findings indicate that blinatumomab-induced changes in laboratory parameters were transient, reversible, and not requiring treatment interruptions in responders and nonresponders.

7.
Chem Biol Interact ; 381: 110542, 2023 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-37224992

RESUMO

A library of 43 thiazole derivatives, including 31 previously and 12 newly synthesized in the present study, was evaluated in vitro for their inhibitory properties against bovine pancreatic DNase I. Nine compounds (including three newly synthesized) inhibited the enzyme showing improved inhibitory properties compared to that of the reference crystal violet (IC50 = 346.39 µM). Two compounds (5 and 29) stood out as the most potent DNase I inhibitors, with IC50 values below 100 µM. The 5-LO inhibitory properties of the investigated derivatives were also analyzed due to the importance of this enzyme in the development of neurodegenerative diseases. Compounds (12 and 29) proved to be the most prominent new 5-LO inhibitors, with IC50 values of 60 nM and 56 nM, respectively, in cell-free assay. Four compounds, including one previously (41) and three newly (12, 29 and 30) synthesized, have the ability to inhibit DNase I with IC50 values below 200 µM and 5-LO with IC50 values below 150 nM in cell-free assay. Molecular docking and molecular dynamics simulations were used to clarify DNase I and 5-LO inhibitory properties of the most potent representatives at the molecular level. The newly synthesized compound 29 (4-((4-(3-bromo-4-morpholinophenyl)thiazol-2-yl)amino)phenol) represents the most promising dual DNase I and 5-LO inhibitor, as it inhibited 5-LO in the nanomolar and DNase I in the double-digit micromolar concentration ranges. The results obtained in the present study, together with our recently published results for 4-(4-chlorophenyl)thiazol-2-amines, represent a good basis for the development of new neuroprotective therapeutics based on dual inhibition of DNase I and 5-LO.


Assuntos
Fármacos Neuroprotetores , Tiazóis , Animais , Bovinos , Relação Estrutura-Atividade , Tiazóis/farmacologia , Tiazóis/química , Simulação de Acoplamento Molecular , Fármacos Neuroprotetores/farmacologia , Araquidonato 5-Lipoxigenase , Desoxirribonuclease I , Inibidores de Lipoxigenase/farmacologia , Estrutura Molecular
8.
Genes Dev ; 37(5-6): 171-190, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36859339

RESUMO

Both the presence of an abnormal complement of chromosomes (aneuploidy) and an increased frequency of chromosome missegregation (chromosomal instability) are hallmarks of cancer. Analyses of cancer genome data have identified certain aneuploidy patterns in tumors; however, the bases behind their selection are largely unexplored. By establishing time-resolved long-term adaptation protocols, we found that human cells adapt to persistent spindle assembly checkpoint (SAC) inhibition by acquiring specific chromosome arm gains and losses. Independently adapted populations converge on complex karyotypes, which over time are refined to contain ever smaller chromosomal changes. Of note, the frequencies of chromosome arm gains in adapted cells correlate with those detected in cancers, suggesting that our cellular adaptation approach recapitulates selective traits that dictate the selection of aneuploidies frequently observed across many cancer types. We further engineered specific aneuploidies to determine the genetic basis behind the observed karyotype patterns. These experiments demonstrated that the adapted and engineered aneuploid cell lines limit CIN by extending mitotic duration. Heterozygous deletions of key SAC and APC/C genes recapitulated the rescue phenotypes of the monosomic chromosomes. We conclude that aneuploidy-induced gene dosage imbalances of individual mitotic regulators are sufficient for altering mitotic timing to reduce CIN.


Assuntos
Pontos de Checagem da Fase M do Ciclo Celular , Neoplasias , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Aneuploidia , Neoplasias/genética , Instabilidade Cromossômica/genética , Cariótipo , Fuso Acromático/genética , Mitose
9.
Molecules ; 28(2)2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36677597

RESUMO

Three new monosquaramides (3a-c) were synthesized, characterized by IR, NMR and X-ray, and evaluated for inhibitory activity against deoxyribonuclease I (DNase I) and xanthine oxidase (XO) in vitro. The target compounds inhibited DNase I with IC50 values below 100 µM, being at the same time more potent DNase I inhibitors than crystal violet, used as a positive control. 3-Ethoxy-4-((1-(pyridin-3-yl)propan-2-yl)amino)cyclobut-3-ene-1,2-dione (3c) stood out as the most potent compound, exhibiting a slightly better IC50 value (48.04 ± 7.98 µM) compared to the other two compounds. In order to analyze potential binding sites for the studied compounds with DNase I, a molecular docking study was performed. Compounds 3a-c are among the most potent small organic DNase I inhibitors tested to date.


Assuntos
Desoxirribonuclease I , Inibidores Enzimáticos , Relação Estrutura-Atividade , Simulação de Acoplamento Molecular , Inibidores Enzimáticos/farmacologia , Inibidores Enzimáticos/química , Desoxirribonuclease I/química , Desoxirribonuclease I/metabolismo , Xantina Oxidase
10.
Acta Chim Slov ; 69(3): 571-583, 2022 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-36196811

RESUMO

Chemical modifications of natural monoterpenoids to various derivatives have been reported to result in enhancement of biological activities when compared to parent compounds. In this context a well-known biocide and food additive, carvacrol, served as a basic scaffold onto which a phenolic functionality transformation by introducing acyl groups was performed. By using this simple methodology, we obtained a small series of 25 esters. For each of the obtained compounds we have performed structural characterization, in vitro antimicrobial testing and in silico calculation of physico-chemical, pharmacokinetic and toxicological properties. Despite numerous data on the synthesis and bioactivity of carvacryl ester lower homologues, there are scarce data on esters with acid components higher than C9, so that among 25 compounds, 10 were reported for the first time (spectral characterization for 12 are herein the first reported). Our research is also the first comprehensive study of carvacryl esters antifungal and of medium/long chain fatty acid esters antibacterial activities. Interesting result is that all the synthesized esters, regardless the nature of the R residue, have shown activity on fungal strain Aspergilus niger and on yeast Candida albicans comparable to carvacrol. Besides presented experimental data, implementation of in silico calculation of physico-chemical, pharmacokinetic and toxicological properties on the prepared compounds, may be valuable information in further research.


Assuntos
Anti-Infecciosos , Desinfetantes , Antibacterianos , Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Antifúngicos , Candida albicans , Cimenos , Ésteres/farmacologia , Ácidos Graxos , Aditivos Alimentares , Testes de Sensibilidade Microbiana , Monoterpenos/química , Monoterpenos/farmacologia , Fenóis , Timol
11.
Pediatr Blood Cancer ; 68(12): e29323, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34519430

RESUMO

Blinatumomab is a BiTE® (bispecific T-cell engager) immuno-oncology therapy, which has demonstrated significant activity in patients with relapsed or refractory B-cell precursor acute lymphoblastic leukemia (R/R B-ALL); however, a subset of patients relapse. Monitoring expression of cluster of differentiation (CD)19 in relapsed patients is critical to inform sequencing of subsequent therapies. The expression of CD19 in 59 pediatric patients with R/R B-ALL was analyzed on the day of diagnosis of R/R B-ALL and on days 15 and 29 of cycle 1 of blinatumomab. Most patients treated with one cycle of blinatumomab retained expression of CD19, and would therefore be eligible for subsequent anti-CD19 CAR T-cell therapy.


Assuntos
Anticorpos Biespecíficos , Antineoplásicos , Linfoma de Células B , Leucemia-Linfoma Linfoblástico de Células Precursoras , Doença Aguda , Antígenos CD19/metabolismo , Antineoplásicos/efeitos adversos , Criança , Humanos , Linfoma de Células B/tratamento farmacológico , Leucemia-Linfoma Linfoblástico de Células Precursoras/tratamento farmacológico
12.
Foods ; 9(10)2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32977641

RESUMO

Virgin olive oil (VOO) is a functional food specific to the Mediterranean diet and related to human health, especially as a protector of cardiovascular health, in the prevention of several types of cancers, and in modification of immune and inflammatory response. Phenolic compounds have central importance for these extraordinary health benefits. In the production of high-quality olive oils, it is very important to process freshly picked olives and avoid any storage of fruits. However, in Croatia there is a very traditional and environmentally friendly method of olive oil production, where olive fruits are stored in seawater for some time prior to processing. This practice is also notable nowadays since there are people who prefer the characteristic flavor of the "seawater olive oil", although some people argue against its quality and biomedical relevance. In this study, the phenolic contents of VOO prepared from the immediately processed fresh olives and olives processed after storage in seawater were compared with the use of high-performance liquid chromatography-mass spectrometry (HPLC-MS) and spectrophotometric analysis. The results suggest that "seawater olive oil" should be considered as a safe food of biomedical relevance, as it still contains a significant proportion of important phenolics like hydroxytyrosol, tyrosol and oleacein (e.g., 63.2% of total phenols in comparison to VOO).

13.
Antioxidants (Basel) ; 9(5)2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32456297

RESUMO

The roles of phenolics from olive oils as effective anticancer agents have been documented in various in vitro studies of different cancer cells lines, but the relationship between the phenolic profile of olive oil and its biological activity needs more elucidation. In this study, we analysed phenolic profiles of extra virgin olive oils (EVOOs) from different autochthonous cultivars from Croatia (Oblica, Bjelica, Buza, Zizolera) and investigated the biological effect of EVOO phenolic extracts (EVOO-PEs) on human cervical (HeLa) and human colon (SW48) cancer cell lines alone and in combination with cisplatin (cDDP), carboplatin (CBP), 5-fluorouracil (5-FU) and irinotecan. The quantitative evaluation of olive oil polyphenols was performed by HPLC-DAD and spectrophotometric analysis. The biological effect of EVOO-PEs alone and in combination with anticancer drugs was measured by MTT assay. Analysed EVOO-PEs differ in phenolic profile and inhibited HeLa and SW48 cells in a dose-dependent manner. Further, it is shown that EVOO-PEs (Oblica-Sea, Buza and Zizolera), in combination with anticancer drugs, increase the metabolic activity of HeLa and SW48 cells and have a protective role. These data imply careful consummation of olive oil during chemotherapy of cancer patients.

14.
Molecules ; 25(6)2020 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-32210039

RESUMO

Recent experimental studies of kinetic isotope effects (KIE-s) and hydrogen tunnelling comprising three proton-coupled electron transfer (PCET) oxidations of ascorbate monoanion, (a) in aqueous reaction solutions, (b) in the mixed water-organic cosolvent systems, (c) in aqueous solutions of various salts and (d) in fairly diluted aqueous solutions of the various partial hydrophobes are reviewed. A number of new insights into the wealth of the kinetic isotope phenomena in the PCET reactions have been obtained. The modulation of KIE-s and hydrogen tunnelling observed when partially hydrophobic solutes are added into water reaction solution, in the case of fairly diluted solutions is revealed as the strong linear correlation of the isotopic ratios of the Arrhenius prefactors Ah/Ad and the isotopic differences in activation energies ΔEa (D,H). The observation has been proposed to be a signature of the involvement of the collective intermolecular excitonic vibrational dynamics of water in activation processes and aqueous chemistry.


Assuntos
Ácido Ascórbico/química , Hidrogênio/química , Modelos Químicos , Água/química , Isótopos/química , Cinética , Oxirredução
15.
Acta Pharm ; 69(4): 461-482, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31639094

RESUMO

Cancer presents one of the leading causes of death in the world. Current treatment includes the administration of one or more anticancer drugs, commonly known as chemotherapy. The biggest issue concerning the chemotherapeutics is their toxicity on normal cells and persisting side effects. One approach to the issue is chemoprevention and the other one is the discovery of more effective drugs or drug combinations, including combinations with polyphenols. Olive oil polyphenols (OOPs), especially hydroxytyrosol (HTyr), tyrosol (Tyr) and their derivatives oleuropein (Ole), oleacein and oleocanthal (Oc) express anticancer activity on different cancer models. Recent studies report that phenolic extract of virgin olive oil may be more effective than the individual phenolic compounds. Also, there is a growing body of evidence about the combined treatment of OOPs with various anticancer drugs, such as cisplatin, tamoxifen, doxorubicin and others. These novel approaches may present an advanced strategy in the prevention and treatment of cancer.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias/tratamento farmacológico , Azeite de Oliva/uso terapêutico , Polifenóis/uso terapêutico , Antioxidantes/uso terapêutico , Quimioterapia Combinada , Humanos
16.
Molecules ; 24(10)2019 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-31137753

RESUMO

The Mediterranean diet and olive oil as its quintessential part are almost synonymous with a healthy way of eating and living nowadays. This kind of diet has been highly appreciated and is widely recognized for being associated with many favorable effects, such as reduced incidence of different chronic diseases and prolonged longevity. Although olive oil polyphenols present a minor fraction in the composition of olive oil, they seem to be of great importance when it comes to the health benefits, and interest in their biological and potential therapeutic effects is huge. There is a growing body of in vitro and in vivo studies, as well as intervention-based clinical trials, revealing new aspects of already known and many new, previously unknown activities and health effects of these compounds. This review summarizes recent findings regarding biological activities, metabolism and bioavailability of the major olive oil phenolic compounds-hydroxytyrosol, tyrosol, oleuropein, oleocanthal and oleacein-the most important being their antiatherogenic, cardioprotective, anticancer, neuroprotective and endocrine effects. The evidence presented in the review concludes that these phenolic compounds have great pharmacological potential, however, further studies are still required.


Assuntos
Saúde , Álcool Feniletílico/análogos & derivados , Antineoplásicos/farmacologia , Cardiotônicos/farmacologia , Humanos , Fármacos Neuroprotetores/farmacologia , Álcool Feniletílico/química , Álcool Feniletílico/farmacologia
17.
Molecules ; 25(1)2019 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-31906197

RESUMO

Our study of tunnelling in proton-coupled electron transfer (PCET) oxidation of ascorbate with hexacyanoferrate(III) follows the insights obtained from ultrafast 2D IR spectroscopy and theoretical studies of the vibrational water dynamics that led to the proposal of the involvement of collective intermolecular excitonic vibrational water dynamics in aqueous chemistry. To test the proposal, the hydrogen tunnelling modulation observed in the PCET reaction studied in the presence of low concentrations of various partial hydrophobic solutes in the water reaction system has been analyzed in terms of the proposed involvement of the collective intermolecular vibrational water dynamics in activation process in the case. The strongly linear correlation between common tunnelling signatures, isotopic values of Arrhenius prefactor ratios ln AH/AD and isotopic differences in activation enthalpies ΔΔH‡ (H,D) observed in the process in fairly diluted water solutions containing various partial hydrophobic solutes (such as dioxane, acetonitrile, ethanol, and quaternary ammonium ions) points to the common physical origin of the phenomenon in all the cases. It is suggested that the phenomenon can be rooted in an interplay of delocalized collective intermolecular vibrational dynamics of water correlated with vibrations of the coupled transition configuration, where the donor-acceptor oscillations, the motions being to some degree along the reaction coordinate, lead to modulation of hydrogen tunnelling in the reaction.


Assuntos
Hidrogênio/química , Água/química , Acetonitrilas/química , Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/química , Dioxanos/química , Elétrons , Etanol/química , Ferricianetos/química , Ligação de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Cinética , Oxirredução , Prótons , Soluções/química , Termodinâmica , Vibração
18.
Clin Cancer Res ; 23(17): 5162-5175, 2017 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-28522603

RESUMO

Purpose: We previously demonstrated an association between decreased SMAD4 expression and cetuximab resistance in head and neck squamous cell carcinoma (HNSCC). The purpose of this study was to further elucidate the clinical relevance of SMAD4 loss in HNSCC.Experimental Design: SMAD4 expression was assessed by IHC in 130 newly diagnosed and 43 patients with recurrent HNSCC. Correlative statistical analysis with clinicopathologic data was also performed. OncoFinder, a bioinformatics tool, was used to analyze molecular signaling in TCGA tumors with low or high SMAD4 mRNA levels. The role of SMAD4 was investigated by shRNA knockdown and gene reconstitution of HPV-negative HNSCC cell lines in vitro and in vivoResults: Our analysis revealed that SMAD4 loss was associated with an aggressive, HPV-negative, cetuximab-resistant phenotype. We found a signature of prosurvival and antiapoptotic pathways that were commonly dysregulated in SMAD4-low cases derived from TCGA-HNSCC dataset and an independent oral cavity squamous cell carcinoma (OSCC) cohort obtained from GEO. We show that SMAD4 depletion in an HNSCC cell line induces cetuximab resistance and results in worse survival in an orthotopic mouse model in vivo We implicate JNK and MAPK activation as mediators of cetuximab resistance and provide the foundation for the concomitant EGFR and JNK/MAPK inhibition as a potential strategy for overcoming cetuximab resistance in HNSCCs with SMAD4 loss.Conclusions: Our study demonstrates that loss of SMAD4 expression is a signature characterizing the cetuximab-resistant phenotype and suggests that SMAD4 expression may be a determinant of sensitivity/resistance to EGFR/MAPK or EGFR/JNK inhibition in HPV-negative HNSCC tumors. Clin Cancer Res; 23(17); 5162-75. ©2017 AACR.


Assuntos
Resistencia a Medicamentos Antineoplásicos/genética , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Recidiva Local de Neoplasia/tratamento farmacológico , Proteína Smad4/genética , Idoso , Animais , Anticorpos Monoclonais Humanizados/administração & dosagem , Linhagem Celular Tumoral , Cetuximab/administração & dosagem , Receptores ErbB/genética , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/patologia , Humanos , MAP Quinase Quinase 1/genética , Camundongos , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/genética , Recidiva Local de Neoplasia/patologia , Papillomaviridae/patogenicidade , Inibidores de Proteínas Quinases/administração & dosagem , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Ann Nucl Med ; 28(8): 736-45, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24947176

RESUMO

OBJECTIVE: The aim was quantitative assessment of parathyroid adenoma (PTA) uptake in dual tracer dynamic scintigraphy. METHODS: In 78 patients, median age 58 (19-80) years, surgically treated for primary hyperparathyroidism (PHPT), with parathyroid hormone median 125 (70-658) pg/ml, we performed preoperative parathyroid scintigraphy, following EANM guidelines of subtraction and double-phase protocol (2009) using two tracers: Tc-99m pertechnetate and Tc-99m MIBI. In addition to standard subtraction processing and visual interpretation of delayed MIBI planar images of neck and mediastinum in oblique sections (positions according to ultrasound PTA localisation), we developed Submarine processing software that enables selecting custom regions grid sizes ≥6 mm (as this solution was not present in commercial software) to follow time activity curve changes in thyroid tissue and PTA. Histopathology in 53/78 patients revealed PHPT and in 25/78 patients thyroid nodular disease only, and thyroid malignancy occurred in total of 15/78 (19 %) patients. PHPT group included 44 solitary PTA, 8 patients with hyperplasia and one parathyroid carcinoma. The median macroscopic volume of PTA was 717.5 (15-6125) mm(3). Concomitant PHPT and thyroid nodular disease occurred in 24/53 patients and among them 8 patients had thyroid malignancies. RESULTS: PTA showed typical pattern of late peak on time activity curves characterized by median start time on 15 (10-25) min, the peak amplitude mean 19 (±5) % above thyroid declining washout curve, and duration of peak 6 (4-10) min, allowing PTA to "emerge" like submarine, independent from thyroid tissue and lesions. The ratio of PTA-to-normal thyroid uptake at peak maximum was 1.35 (±0.21). The thyroid TACs results of normal 29/78 (37 %) patients, benign nodular 34/78 (44 %) patients, and malignancy in 15 (19 %) patients were all presented by declining exponential curves. The slope analysis of TACs in normal thyroid tissue, thyroid benign and malignant lesions (linear fitted logarithm of TAC) showed no difference (the same negative slope: -0.04). Submarine processing was sensitive in detection of small lesions, in hyperplasia, and concomitant thyroid nodular disease. CONCLUSIONS: The novel Submarine processing confirmed specific PHPT pattern and was effective in the group with potential pitfalls of standard interpretation, increasing sensitivity and specificity of standard processing subtraction algorithm. Prolonged MIBI accumulation was present in malignant as well as benign thyroid nodules with identical TAC slope.


Assuntos
Adenoma/diagnóstico por imagem , Neoplasias das Paratireoides/diagnóstico por imagem , Cintilografia/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Variações Dependentes do Observador , Hormônio Paratireóideo/metabolismo , Reprodutibilidade dos Testes , Pertecnetato Tc 99m de Sódio , Software , Tecnécio Tc 99m Sestamibi , Adulto Jovem
20.
Comput Biol Med ; 50: 97-106, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24845020

RESUMO

We designed the GammaKey system for the acquisition, storage and analysis of images from semi-analogue gamma scintillation cameras (GSCs). The GammaKey system, operating on a standard PC, replicates the functionality of earlier dedicated computer systems, allows the exchange of data in the DICOM format and has an open architecture enabling the development of new diagnostic techniques. The main purpose of the GammaKey is to enable the continued use of old GSCs which have functional scintillation crystals, but also to permit data exchange with new digital GSCs. The GammaKey has been technically validated by standards established by the National Electrical Manufacturers Association. The GammaKey has been used for seven years in two leading centres for nuclear medicine in Serbia (the Clinical Center of Serbia, Belgrade, and the Clinical Center of Vojvodina, Novi Sad) in approximately 30,000 patients. Clinical application proves that the GammaKey is a robust and reliable system with high-quality image output. Data processing can be upgraded with non-standard features added on request as shown in two examples: (1) the testing of splenectomy efficacy in the case of thrombocytopenia with normal production; and (2) the detection and localisation of parathyroid adenomas.


Assuntos
Câmaras gama , Processamento de Imagem Assistida por Computador/métodos , Informática Médica/métodos , Algoritmos , Automação , Sistemas Computacionais , Humanos , Pulmão/diagnóstico por imagem , Medicina Nuclear/métodos , Neoplasias das Paratireoides/diagnóstico por imagem , Perfusão , Cintilografia , Saliva/metabolismo , Sérvia , Software , Esplenectomia/métodos , Trombocitopenia/cirurgia
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