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1.
Phys Chem Chem Phys ; 26(14): 10610-10621, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38506638

RESUMO

The structure and clustering propensity of a chiral derivative of cis-1,2-cyclohexanediol, namely, 1-phenyl-cis-1,2-cyclohexanediol (cis-PCD), has been studied under supersonic expansion conditions by combining laser spectroscopy with quantum chemistry calculations. The presence of the phenyl substituent induces conformational locking relative to cis-1,2-cyclohexanediol (cis-CD), and only one conformer of the bare molecule is observed by both Raman and IR-UV double resonance spectroscopy. The homochiral preference inferred for the dimer formation at low enough temperature is in line with the formation of a conglomerate in the solid state. The change in clustering propensity in cis-PCD relative to trans-1,2-cyclohexanediol (trans-CD), which shows heterochiral preference, is explained by the presence of the phenyl substituent rather than the effect of cis-trans isomerism. Indeed the transiently chiral cis-CD also forms preferentially heterodimers, whose structure is very close to that of the corresponding trans-CD dimer.

2.
Angew Chem Int Ed Engl ; 63(17): e202401423, 2024 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-38442011

RESUMO

Conformational flexibility and chirality both play a key role in molecular recognition. It is therefore very useful to develop spectroscopic methods that simultaneously probe both properties. It has been theoretically predicted that photoelectron circular dichroism (PECD) should be very sensitive to conformational isomerism. However, experimental proof has been less forthcoming and only exists for a very few favorable cases. Here, we present a new PECD scheme based on resonance-enhanced two-photon ionization (RE2PI) using UV/Vis nanosecond laser excitations. The spectral resolution obtained thereby guarantees conformer-selectivity by inducing resonant conformer-specific ππ* S1←S0 transitions. We apply this experimental scheme to the study of chiral 1-indanol, which exists in two conformers linked by a ring inversion and defined by the position of the hydroxyl group, namely axial and equatorial. We show that the PECD of the equatorial and axial forms considerably differ in sign, magnitude and shape. We also discuss the influence of the total ionization energy, vibronic excitation of intermediate and final states, and relative polarization of the excitation and ionization lasers. Conformer-specificity adds a new dimension to the applications of PECD in analytical chemistry addressing now the general case of floppy systems.

3.
Phys Chem Chem Phys ; 25(33): 22089-22102, 2023 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-37610422

RESUMO

Vibrational spectroscopy in supersonic jet expansions is a powerful tool to assess molecular aggregates in close to ideal conditions for the benchmarking of quantum chemical approaches. The low temperatures achieved as well as the absence of environment effects allow for a direct comparison between computed and experimental spectra. This provides potential benchmarking data which can be revisited to hone different computational techniques, and it allows for the critical analysis of procedures under the setting of a blind challenge. In the latter case, the final result is unknown to modellers, providing an unbiased testing opportunity for quantum chemical models. In this work, we present the spectroscopic and computational results for the first HyDRA blind challenge. The latter deals with the prediction of water donor stretching vibrations in monohydrates of organic molecules. This edition features a test set of 10 systems. Experimental water donor OH vibrational wavenumbers for the vacuum-isolated monohydrates of formaldehyde, tetrahydrofuran, pyridine, tetrahydrothiophene, trifluoroethanol, methyl lactate, dimethylimidazolidinone, cyclooctanone, trifluoroacetophenone and 1-phenylcyclohexane-cis-1,2-diol are provided. The results of the challenge show promising predictive properties in both purely quantum mechanical approaches as well as regression and other machine learning strategies.

4.
Am J Physiol Heart Circ Physiol ; 320(1): H169-H180, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33095647

RESUMO

Aging is associated with heart and vascular dysfunction that contributes to cardiovascular disease (CVD) risk. Clinical data support a sexual dimorphism in the time course of aging-associated CVD. However, the mechanisms driving sex differences in cardiovascular aging and whether they can be modeled in mice have not been explored. Mineralocorticoid receptors (MRs) regulate blood pressure, and we previously demonstrated in male mice that MR expression increases in aging mouse vessels and smooth muscle cell-specific MR deletion (SMC-MR-KO) protects from cardiovascular aging. This study characterizes sex differences in murine cardiovascular aging and the associated sex-specific role of SMC-MR. Aortic stiffness, measured by pulse wave velocity, increased from 3 to 12 mo of age in males but not until 18 mo in females. The timing of the rise in aortic stiffening correlated with the timing of increased aortic MR expression, and aortic stiffness did not increase with age in SMC-MR-KO mice of both sexes. Vascular fibrosis increased at 12 mo in males and later at 18 mo in females; however, fibrosis was attenuated by SMC-MR-KO in males only. In resistance vessels, angiotensin type 1 receptor (AT1R)-mediated vasoconstriction also increased at 12 mo in males and 18 mo in females. ANG II-induced vasoconstriction was decreased in SMC-MR-KO specifically in males in association with decreased AT1R expression. Cardiac systolic function declined in males and females by 18 mo of age, which was prevented by SMC-MR-KO specifically in females. Cardiac perivascular fibrosis increased with age in both sexes accompanied by sex-specific changes in the expression levels of MR-regulated profibrotic genes.NEW & NOTEWORTHY These data demonstrate that the delayed and steeper decline in cardiovascular function observed in aging females can be modeled in aging mice. Moreover, the mechanisms driving vascular and cardiac aging phenotypes are distinct between males and females. Mineralocorticoid receptors in smooth muscle cells play a significant role in cardiovascular aging in both sexes; however, they do so by distinct mechanisms. Overall, these findings suggest that sex-specific therapies may be necessary to retard the aging process and improve cardiovascular disease outcomes in the aging population.


Assuntos
Envelhecimento/metabolismo , Doenças Cardiovasculares/metabolismo , Músculo Liso Vascular/metabolismo , Miocárdio/metabolismo , Receptores de Mineralocorticoides/metabolismo , Fatores Etários , Animais , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/prevenção & controle , Feminino , Fibrose , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Músculo Liso Vascular/fisiopatologia , Receptores de Mineralocorticoides/genética , Fatores Sexuais , Transdução de Sinais , Fatores de Tempo , Remodelação Vascular , Rigidez Vascular
6.
Analyst ; 143(16): 3829-3840, 2018 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-29999046

RESUMO

Tumor spheroids represent a realistic 3D in vitro cancer model because they provide a missing link between monolayer cell culture and live tissues. While microfluidic chips can easily form and assay thousands of spheroids simultaneously, few commercial instruments are available to analyze this massive amount of data. Available techniques to measure spheroid response to external stimuli, such as confocal imaging and flow cytometry, are either not appropriate for 3D cultures, or destructive. We designed a wide-field hyperspectral imaging system to analyze multiple spheroids trapped in a microfluidic chip in a single acquisition. The system and its fluorescence quantification algorithm were assessed using liquid phantoms mimicking spheroid optical properties. Spectral unmixing was tested on three overlapping spectral entities. Hyperspectral images of co-culture spheroids expressing two fluorophores were compared with confocal microscopy and spheroid growth was measured over time. The system can spectrally analyze multiple fluorescent markers simultaneously and allows multiple time-points assays, providing a fast and versatile solution for analyzing lab on a chip devices.


Assuntos
Dispositivos Lab-On-A-Chip , Imagem Óptica , Esferoides Celulares , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Feminino , Humanos
7.
Angew Chem Int Ed Engl ; 57(12): 3228-3232, 2018 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-29393563

RESUMO

The borrowing hydrogen strategy has been applied to the ethylation of imines with an air-stable iron complex as precatalyst. This approach opens new perspectives in this area as it enables the synthesis of unsymmetric tertiary amines from readily available substrates and ethanol as a C2 building block. A variety of imines bearing electron-rich aryl or alkyl groups at the nitrogen atom could be efficiently reductively alkylated without the need for molecular hydrogen. The mechanism of this reaction, which shows complete selectivity for ethanol over other alcohols, has been studied experimentally and by means of DFT computations.

8.
Am J Physiol Renal Physiol ; 306(12): F1499-506, 2014 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-24761000

RESUMO

Oxidative stress promotes vascular dysfunction in chronic kidney disease (CKD). We utilized the cutaneous circulation to test the hypothesis that reactive oxygen species derived from NADPH oxidase and xanthine oxidase impair nitric oxide (NO)-dependent cutaneous vasodilation in CKD. Twenty subjects, 10 stage 3 and 4 patients with CKD (61 ± 4 yr; 5 men/5 women; eGFR: 39 ± 4 ml·min(-1)·1.73 m(-2)) and 10 healthy controls (55 ± 2 yr; 4 men/6 women; eGFR: >60 ml·min(-1)·1.73 m(-2)) were instrumented with 4 intradermal microdialysis fibers for the delivery of 1) Ringer solution (Control), 2) 10 µM tempol (scavenge superoxide), 3) 100 µM apocynin (NAD(P)H oxidase inhibition), and 4) 10 µM allopurinol (xanthine oxidase inhibition). Skin blood flow was measured via laser-Doppler flowmetry during standardized local heating (42°C). N(g)-nitro-l-arginine methyl ester (L-NAME; 10 mM) was infused to quantify the NO-dependent portion of the response. Cutaneous vascular conductance (CVC) was calculated as a percentage of the maximum CVC achieved during sodium nitroprusside infusion at 43°C. Cutaneous vasodilation was attenuated in patients with CKD (77 ± 3 vs. 88 ± 3%, P = 0.01), but augmented with tempol and apocynin (tempol: 88 ± 2 (P = 0.03), apocynin: 91 ± 2% (P = 0.001). The NO-dependent portion of the response was reduced in patients with CKD (41 ± 4 vs. 58 ± 2%, P = 0.04), but improved with tempol and apocynin (tempol: 58 ± 3 (P = 0.03), apocynin: 58 ± 4% (P = 0.03). Inhibition of xanthine oxidase did not alter cutaneous vasodilation in either group (P > 0.05). These data suggest that NAD(P)H oxidase is a source of reactive oxygen species and contributes to microvascular dysfunction in patients with CKD.


Assuntos
Microvasos/metabolismo , Microvasos/fisiopatologia , NADPH Oxidases/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/fisiopatologia , Pele/irrigação sanguínea , Acetofenonas/farmacologia , Adulto , Idoso , Alopurinol/farmacologia , Antioxidantes/farmacologia , Estudos de Casos e Controles , Óxidos N-Cíclicos/farmacologia , Feminino , Sequestradores de Radicais Livres/farmacologia , Humanos , Masculino , Pessoa de Meia-Idade , Fluxo Sanguíneo Regional/efeitos dos fármacos , Fluxo Sanguíneo Regional/fisiologia , Índice de Gravidade de Doença , Marcadores de Spin , Vasodilatação/efeitos dos fármacos , Vasodilatação/fisiologia , Xantina Oxidase/metabolismo
9.
Nat Commun ; 14(1): 6290, 2023 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-37813848

RESUMO

An achiral chromophore can acquire a chiral spectroscopic signature when interacting with a chiral environment. This so-called induced chirality is documented in electronic or vibrational circular dichroism, which arises from the coupling between electric and magnetic transition dipoles. Here, we demonstrate that a chiroptical response is also induced within the electric dipole approximation by observing the asymmetric scattering of a photoelectron ejected from an achiral chromophore in interaction with a chiral host. In a phenol-methyloxirane complex, removing an electron from an achiral aromatic π orbital localised on the phenol moiety results in an intense and opposite photoelectron circular dichroism (PECD) for the two enantiomeric complexes with (R) and (S) methyloxirane, evidencing the long-range effect (~5 Å) of the scattering chiral potential. This induced chirality has important structural and analytical implications, discussed here in the context of growing interest in laser-based PECD, for in situ, real time enantiomer determination.

10.
Cardiovasc Res ; 118(17): 3386-3400, 2023 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35020830

RESUMO

AIMS: Vascular stiffness increases with age and independently predicts cardiovascular disease risk. Epigenetic changes, including histone modifications, accumulate with age but the global pattern has not been elucidated nor are the regulators known. Smooth muscle cell-mineralocorticoid receptor (SMC-MR) contributes to vascular stiffness in ageing mice. Thus, we investigated the regulatory role of SMC-MR in vascular epigenetics and stiffness. METHODS AND RESULTS: Mass spectrometry-based proteomic profiling of all histone modifications completely distinguished 3 from 12-month-old mouse aortas. Histone-H3 lysine-27 (H3K27) methylation (me) significantly decreased in ageing vessels and this was attenuated in SMC-MR-KO littermates. Immunoblotting revealed less H3K27-specific methyltransferase EZH2 with age in MR-intact but not SMC-MR-KO vessels. These ageing changes were examined in primary human aortic (HA)SMC from adult vs. aged donors. MR, H3K27 acetylation (ac), and stiffness gene (connective tissue growth factor, integrin-α5) expression significantly increased, while H3K27me and EZH2 decreased, with age. MR inhibition reversed these ageing changes in HASMC and the decline in stiffness genes was prevented by EZH2 blockade. Atomic force microscopy revealed that MR antagonism decreased intrinsic stiffness and the probability of fibronectin adhesion of aged HASMC. Conversely, ageing induction in young HASMC with H2O2; increased MR, decreased EZH2, enriched H3K27ac and MR at stiffness gene promoters by chromatin immunoprecipitation, and increased stiffness gene expression. In 12-month-old mice, MR antagonism increased aortic EZH2 and H3K27 methylation, increased EZH2 recruitment and decreased H3K27ac at stiffness genes promoters, and prevented ageing-induced vascular stiffness and fibrosis. Finally, in human aortic tissue, age positively correlated with MR and stiffness gene expression and negatively correlated with H3K27me3 while MR and EZH2 are negatively correlated. CONCLUSION: These data support a novel vascular ageing model with rising MR in human SMC suppressing EZH2 expression thereby decreasing H3K27me, promoting MR recruitment and H3K27ac at stiffness gene promoters to induce vascular stiffness and suggests new targets for ameliorating ageing-associated vascular disease.


Assuntos
Epigênese Genética , Peróxido de Hidrogênio , Receptores de Mineralocorticoides , Adulto , Idoso , Animais , Humanos , Camundongos , Envelhecimento/genética , Proteína Potenciadora do Homólogo 2 de Zeste/genética , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Peróxido de Hidrogênio/metabolismo , Músculo Liso/metabolismo , Proteômica , Receptores de Mineralocorticoides/genética , Receptores de Mineralocorticoides/metabolismo
11.
J Physiol ; 590(21): 5519-28, 2012 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-22907057

RESUMO

Animal studies have reported dietary salt-induced reductions in vascular function independent of increases in blood pressure (BP). The purpose of this study was to determine if short-term dietary sodium loading impairs cutaneous microvascular function in normotensive adults with salt resistance. Following a control run-in diet, 12 normotensive adults (31 ± 2 years) were randomized to a 7 day low-sodium (LS; 20 mmol day(-1)) and 7 day high-sodium (HS; 350 mmol day(-1)) diet (controlled feeding study). Salt resistance, defined as a 5 mmHg change in 24 h mean BP determined while on the LS and HS diets, was confirmed in all subjects undergoing study (LS: 84 ± 1 mmHg vs. HS: 85 ± 2 mmHg; P > 0.05). On the last day of each diet, subjects were instrumented with two microdialysis fibres for the local delivery of Ringer solution and 20 mm ascorbic acid (AA). Laser Doppler flowmetry was used to measure red blood cell flux during local heating-induced vasodilatation (42°C). After the established plateau, 10 mm l-NAME was perfused to quantify NO-dependent vasodilatation. All data were expressed as a percentage of maximal cutaneous vascular conductance (CVC) at each site (28 mm sodium nitroprusside; 43°C). Sodium excretion increased during the HS diet (P < 0.05). The plateau % CVCmax was reduced during HS (LS: 93 ± 1 % CVCmax vs. HS: 80 ± 2 % CVCmax; P < 0.05). During the HS diet, AA improved the plateau % CVCmax (Ringer: 80 ± 2 % CVCmax vs. AA: 89 ± 3 % CVCmax; P < 0.05) and restored the NO contribution (Ringer: 44 ± 3 % CVCmax vs. AA: 59 ± 6 % CVCmax; P < 0.05). These data demonstrate that dietary sodium loading impairs cutaneous microvascular function independent of BP in normotensive adults and suggest a role for oxidative stress.


Assuntos
Microvasos/efeitos dos fármacos , Estresse Oxidativo , Sódio na Dieta/farmacologia , Adulto , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Pressão Sanguínea , Feminino , Humanos , Masculino , Microvasos/fisiologia , Estresse Oxidativo/efeitos dos fármacos
12.
BMC Med Imaging ; 12: 35, 2012 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-23253859

RESUMO

BACKGROUND: To determine the general appearance of normal axillary lymph nodes (LNs) in real-time tissue sonoelastography and to explore the method's potential value in the prediction of LN metastases. METHODS: Axillary LNs in healthy probands (n=165) and metastatic LNs in breast cancer patients (n=15) were examined with palpation, B-mode ultrasound, Doppler and sonoelastography (assessment of the elasticity of the cortex and the medulla). The elasticity distributions were compared and sensitivity (SE) and specificity (SP) were calculated. In an exploratory analysis, positive and negative predictive values (PPV, NPV) were calculated based upon the estimated prevalence of LN metastases in different risk groups. RESULTS: In the elastogram, the LN cortex was significantly harder than the medulla in both healthy (p=0.004) and metastatic LNs (p=0.005). Comparing healthy and metastatic LNs, there was no difference in the elasticity distribution of the medulla (p=0.281), but we found a significantly harder cortex in metastatic LNs (p=0.006). The SE of clinical examination, B-mode ultrasound, Doppler ultrasound and sonoelastography was revealed to be 13.3%, 40.0%, 14.3% and 60.0%, respectively, and SP was 88.4%, 96.8%, 95.6% and 79.6%, respectively. The highest SE was achieved by the disjunctive combination of B-mode and elastographic features (cortex >3mm in B-mode or blue cortex in the elastogram, SE=73.3%). The highest SP was achieved by the conjunctive combination of B-mode ultrasound and elastography (cortex >3mm in B-mode and blue cortex in the elastogram, SP=99.3%). CONCLUSIONS: Sonoelastography is a feasible method to visualize the elasticity distribution of LNs. Moreover, sonoelastography is capable of detecting elasticity differences between the cortex and medulla, and between metastatic and healthy LNs. Therefore, sonoelastography yields additional information about axillary LN status and can improve the PPV, although this method is still experimental.


Assuntos
Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/secundário , Técnicas de Imagem por Elasticidade/estatística & dados numéricos , Interpretação de Imagem Assistida por Computador/métodos , Linfonodos/diagnóstico por imagem , Linfonodos/fisiopatologia , Ultrassonografia Mamária/estatística & dados numéricos , Axila , Neoplasias da Mama/fisiopatologia , Sistemas Computacionais , Módulo de Elasticidade , Feminino , Humanos , Metástase Linfática , Pessoa de Meia-Idade , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
J Obstet Gynaecol Can ; 34(6): 567-574, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22673173

RESUMO

OBJECTIVE: To investigate biomarkers and clinical parameters to distinguish ovarian cancers from benign ovarian tumours. METHODS: Serum biomarkers (CA 125, human epididymis protein 4 [HE 4], interleukin-18 [IL-18], leptin, macrophage migration inhibitory factor [MIF], fibroblast growth factor 2 [FGF-2], insulin-like growth factor, osteopontin, prolactin) and the risk of malignancy indexes I and II (RMI-I and RMI-II) scores were obtained prior to surgery in 52 patients with ovarian tumours (37 malignant and 15 benign). ROC curves were built for each individual marker, for logistic regression models using all markers, and for models combining both biomarkers and RMI scores. RESULTS: The model with nine biomarkers performed well (specificity 93%, sensitivity 84%) and was more reliable than the RMI-I or RMI-II alone. A regression model combining RMI-II and six of the biomarkers (CA 125, HE  4, IL-18, leptin, MIF, and FGF-2) allowed differentiation between the cancer and non-cancer cases in this pilot study. CONCLUSION: The regression models using biomarkers combined with clinical scoring systems warrant further investigation to improve triage of patients with ovarian tumours to enhance utilization of resources and optimize patient care.


Assuntos
Neoplasias Ovarianas/sangue , Neoplasias Ovarianas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , Antígeno Ca-125/sangue , Feminino , Fator 2 de Crescimento de Fibroblastos/sangue , Humanos , Interleucina-18/sangue , Leptina/sangue , Fatores Inibidores da Migração de Macrófagos/sangue , Pessoa de Meia-Idade , Osteopontina/sangue , Prolactina/sangue , Proteínas/metabolismo , Curva ROC , Somatomedinas/metabolismo , Proteína 2 do Domínio Central WAP de Quatro Dissulfetos , Adulto Jovem
14.
J Phys Chem Lett ; 13(10): 2313-2320, 2022 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-35245057

RESUMO

Chirality plays a fundamental role in the molecular recognition processes. Molecular flexibility is also crucial in molecular recognition, allowing the interacting molecules to adjust their structures and hence optimize the interaction. Methods probing simultaneously chirality and molecular conformation are therefore crucially needed. Taking advantage of a possible control in the gas phase of the conformational distribution between the equatorial and axial conformers resulting from a ring inversion in jet-cooled 1-indanol, we demonstrate here the sensitivity of valence-shell photoelectron circular dichroism (PECD) to both chirality and subtle conformational changes, in a case where the photoelectron spectra of the two conformers are identical. For the highest occupied orbital, we observe a dramatic inversion of the PECD-induced photoelectron asymmetries, while the photoionization cross-section and usual anisotropy (ß) parameter are completely insensitive to conformational isomerism. Such a sensitivity is a major asset for the ongoing developments of PECD-based techniques as a sensitive chiral (bio)chemical analytical tool in the gas phase.


Assuntos
Indanos , Dicroísmo Circular , Indanos/química , Conformação Molecular , Estereoisomerismo
15.
Oncogene ; 41(3): 309-320, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34743206

RESUMO

While aneuploidy is a main enabling characteristic of cancers, it also creates specific vulnerabilities. Here we demonstrate that Ran inhibition targets epithelial ovarian cancer (EOC) survival through its characteristic aneuploidy. We show that induction of aneuploidy in rare diploid EOC cell lines or normal cells renders them highly dependent on Ran. We also establish an inverse correlation between Ran and the tumor suppressor NR1D1 and reveal the critical role of Ran/NR1D1 axis in aneuploidy-associated endogenous DNA damage repair. Mechanistically, we show that Ran, through the maturation of miR4472, destabilizes the mRNA of NR1D1 impacting several DNA repair pathways. We showed that NR1D1 interacts with both PARP1 and BRCA1 leading to the inhibition of DNA repair. Concordantly, loss of Ran was associated with NR1D1 induction, accumulation of DNA damages, and lethality of aneuploid EOC cells. Our findings suggest a synthetic lethal strategy targeting aneuploid cells based on their dependency to Ran.


Assuntos
GTP Fosfo-Hidrolases/metabolismo , Membro 1 do Grupo D da Subfamília 1 de Receptores Nucleares/metabolismo , Neoplasias Ovarianas/genética , Aneuploidia , Animais , Feminino , Humanos , Camundongos
16.
Exp Physiol ; 96(7): 674-80, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21571814

RESUMO

We tested the hypothesis that microdialysis of hypertonic saline would attenuate the skin blood flow response to local heating. Seventeen healthy subjects (23 ± 1 years old) were studied. In one group (n = 9), four microdialysis fibres were placed in the forearm skin and infused with the following: (1) Ringer solution; (2) normal saline (0.9% NaCl); (3) hypertonic saline (3% NaCl); and (4) 10 mm l-NAME. A second group (n = 8) was infused with the following: (1) normal saline; (2) hypertonic saline; (3) normal saline + l-NAME; and (4) hypertonic saline + l-NAME. Red blood cell flux was measured via laser Doppler flowmetry during local heating to 42°C. Site-specific maximal vasodilatation was determined by infusing 28 mm sodium nitroprusside while the skin was heated to 43°C. Data were expressed as the percentage of maximal cutaneous vascular conductance (%CVC(max)). The local heating response at the Ringer solution and normal saline sites did not differ (n = 9; initial peak Ringer solution, 69 ± 6 versus normal saline, 66 ± 2%CVC(max); plateau Ringer solution, 89 ± 4 versus normal saline, 89 ± 5%CVC(max)). Hypertonic saline reduced the initial peak (n = 9; normal saline, 66 ± 2 versus hypertonic saline, 54 ± 4%CVC(max); P < 0.05) and plateau (normal saline, 89 ± 5 versus hypertonic saline, 78 ± 2%CVC(max); P < 0.05) compared with normal saline. Plateau %CVC(max) was attenuated to a similar value at the normal saline + l-NAME and hypertonic saline + l-NAME sites (n = 8; normal saline + l-NAME, 39 ± 6 and hypertonic saline + l-NAME, 39 ± 5%CVC(max)). The nitric oxide contribution (plateau %CVC(max) - l-NAME plateau %CVC(max)) was lower at the hypertonic saline site (normal saline, 55 ± 6 versus hypertonic saline, 35 ± 4; P < 0.01). These data suggest an effect of salt on the cutaneous response to local heating, which may be mediated through a decreased production and/or availability of nitric oxide.


Assuntos
Temperatura Alta , Solução Salina Hipertônica/farmacologia , Pele/irrigação sanguínea , Vasodilatação/fisiologia , Feminino , Humanos , Injeções Intradérmicas , Masculino , Microcirculação/efeitos dos fármacos , Microdiálise , NG-Nitroarginina Metil Éster/farmacologia , Óxido Nítrico/fisiologia , Adulto Jovem
17.
Cancers (Basel) ; 13(16)2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34439362

RESUMO

Predicting patient responses to anticancer drugs is a major challenge both at the drug development stage and during cancer treatment. Tumor explant culture platforms (TECPs) preserve the native tissue architecture and are well-suited for drug response assays. However, tissue longevity in these models is relatively low. Several methodologies have been developed to address this issue, although no study has compared their efficacy in a controlled fashion. We investigated the effect of two variables in TECPs, specifically, the tissue size and culture vessel on tissue survival using micro-dissected tumor tissue (MDT) and tissue slices which were cultured in microfluidic chips and plastic well plates. Tumor models were produced from ovarian and prostate cancer cell line xenografts and were matched in terms of the specimen, total volume of tissue, and respective volume of medium in each culture system. We examined morphology, viability, and hypoxia in the various tumor models. Our observations suggest that the viability and proliferative capacity of MDTs were not affected during the time course of the experiments. In contrast, tissue slices had reduced proliferation and showed increased cell death and hypoxia under both culture conditions. Tissue slices cultured in microfluidic devices had a lower degree of hypoxia compared to those in 96-well plates. Globally, our results show that tissue slices have lower survival rates compared to MDTs due to inherent diffusion limitations, and that microfluidic devices may decrease hypoxia in tumor models.

18.
PLoS One ; 15(8): e0236649, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32797058

RESUMO

The Western North-Pacific (WNP) gray whale feeding grounds are off the northeastern coast of Sakhalin Island, Russia and is comprised of a nearshore and offshore component that can be distinguished by both depth and location. Spatial movements of gray whales within their foraging grounds were examined based on 13 years of opportunistic vessel and shore-based photo-identification surveys. Site fidelity was assessed by examining annual return and resighting rates. Lagged Identification Rates (LIR) analyses were conducted to estimate the residency and transitional movement patterns within the two components of their feeding grounds. In total 243 individuals were identified from 2002-2014, among these were 94 calves. The annual return rate over the period 2002-2014 was 72%, excluding 35 calves only seen one year. Approximately 20% of the individuals identified from 2002-2010 were seen every year after their initial sighting (including eight individuals that returned for 13 consecutive years). The majority (239) of the WNP whales were observed in the nearshore area while only half (122) were found in the deeper offshore area. Within a foraging season, there was a significantly higher probability of gray whales moving from the nearshore to the offshore area. No mother-calf pairs, calves or yearlings were observed in the offshore area, which was increasingly used by mature animals. The annual return rates, and population growth rates that are primarily a result of calf production with little evidence of immigration, suggest that this population is demographically self-contained and that both the nearshore and offshore Sakhalin feeding grounds are critically important areas for their summer annual foraging activities. The nearshore habitat is also important for mother-calf pairs, younger individuals, and recently weaned calves. Nearshore feeding could also be energetically less costly compared to foraging in the deeper offshore habitat and provide more protection from predators, such as killer whales.


Assuntos
Migração Animal , Estações do Ano , Comportamento Espacial , Baleias , Animais , Ecossistema , Comportamento Alimentar , Feminino , Densidade Demográfica , Federação Russa
19.
Cancers (Basel) ; 12(8)2020 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-32784519

RESUMO

Cancer cell lines are amongst the most important pre-clinical models. In the context of epithelial ovarian cancer, a highly heterogeneous disease with diverse subtypes, it is paramount to study a wide panel of models in order to draw a representative picture of the disease. As this lethal gynaecological malignancy has seen little improvement in overall survival in the last decade, it is all the more pressing to support future research with robust and diverse study models. Here, we describe ten novel spontaneously immortalized patient-derived ovarian cancer cell lines, detailing their respective mutational profiles and gene/biomarker expression patterns, as well as their in vitro and in vivo growth characteristics. Eight of the cell lines were classified as high-grade serous, while two were determined to be of the rarer mucinous and clear cell subtypes, respectively. Each of the ten cell lines presents a panel of characteristics reflective of diverse clinically relevant phenomena, including chemotherapeutic resistance, metastatic potential, and subtype-associated mutations and gene/protein expression profiles. Importantly, four cell lines formed subcutaneous tumors in mice, a key characteristic for pre-clinical drug testing. Our work thus contributes significantly to the available models for the study of ovarian cancer, supplying additional tools to better understand this complex disease.

20.
Br J Pharmacol ; 176(21): 4208-4225, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-30767200

RESUMO

Arterial stiffness progressively increases with aging and is an independent predictor of cardiovascular disease (CVD) risk. Evidence supports that there are sex differences in the time course of aging-related arterial stiffness and the associated CVD risk, which increases disproportionately in postmenopausal women. The association between arterial stiffness and mortality is almost twofold higher in women versus men. The differential clinical characteristics of the development of arterial stiffness between men and women indicate the involvement of sex-specific mechanisms. This review summarizes the current literature on sex differences in vascular stiffness induced by aging, obesity, hypertension, and sex-specific risk factors as well as the impact of hormonal status, diet, and exercise on vascular stiffness in males and females. An understanding of the mechanisms driving sex differences in vascular stiffness has the potential to identify novel sex-specific therapies to lessen CVD risk, the leading cause of death in males and females. LINKED ARTICLES: This article is part of a themed section on The Importance of Sex Differences in Pharmacology Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.21/issuetoc.


Assuntos
Caracteres Sexuais , Rigidez Vascular , Animais , Doenças Cardiovasculares , Hormônios Esteroides Gonadais , Humanos , Estilo de Vida , Fatores de Risco
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