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1.
Omega (Westport) ; : 302228241252531, 2024 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-38780620

RESUMO

Medical students face elevated risks of depression and suicide due to rigorous training demands. However, comparative research between medical and non-medical students is limited, hindering understanding of specific risks. This study compared 337 students (89 medical) on suicide risk, depression, perfectionism, burnout, loneliness, and internet addiction. Medical students showed significantly higher suicide risk, depression, perfectionism, burnout, and loneliness. Regression analysis identified medical student status, depressive symptoms, and loneliness as significant predictors of suicide risk. Mediation analysis revealed loneliness and depressive symptoms mediating the relationship between medical student status and suicide risk. Strategies to address mental health risks among medical students are crucial, including early screening and interventions. However, this study's limitations include self-report measures and a predominantly non-medical student sample. Further research is needed to explore causal relationships and interventions effectively.

2.
iScience ; 27(3): 109234, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38482495

RESUMO

Bipolar disorder (BD) is marked by fluctuating mood states over months to years, often with elevated cortisol levels. Elevated cortisol can also trigger mood episodes. Here, we combine longitudinal hair cortisol and mood measurements with mathematical modeling to provide a potential mechanistic link between cortisol and mood timescales in BD. Using 12 cm hair samples, representing a year of growth, we found enhanced year-scale cortisol fluctuations whose amplitude averaged 4-fold higher in BD (n = 26) participants than controls (n = 59). The proximal 2 cm of hair correlated with recent mood scores. Depression (n = 266) and mania (n = 273) scores from a longitudinal study of BD showed similar frequency spectra. These results suggest a mechanism for BD in which high emotional reactivity excites the slow timescales in the hypothalamic-pituitary-adrenal (HPA) axis to generate elevated months-scale cortisol fluctuations, triggering cortisol-induced mood episodes.

3.
Omega (Westport) ; : 302228231215841, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-38124326

RESUMO

Death of patients by suicide can have powerful impacts on mental health professionals (MHPs). The National Program for the Prevention of Suicidality and Suicide at Israel's Ministry of Health decided to invest in MHPs who have lost patients by suicide. Two hundred and two MHPs completed an online self-report survey regarding their emotional response, professional identity, and clinical practice, and the aid they felt would be supportive following a patient's suicide. Results indicated that 35% of MHP experienced at least one death of a patient by suicide. Respondents experienced difficult emotional reactions, and many felt responsible for the suicide. Nearly 50% reported that the patient's suicide affected their clinical practice. Most respondents reported the need for a support framework and information about the processes following a patient's suicide. It is important to increase awareness of the possibility of losing a patient by suicide and offer an appropriate supportive framework.

4.
J Clin Med ; 12(17)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37685771

RESUMO

(1) Background: patients who meet current rapid rule-out criteria for myocardial infarction (MI) are considered low risk, yet their management remains nebulous, especially among women. We aimed to examine sex differences in the diagnosis, management, and outcomes of patients meeting the rapid rule-out criteria. (2) Methods: by simulating application of the rapid rule-out MI criteria, we analyzed consecutively triaged men and women with suspected NSTE-ACS who had high-sensitivity cardiac troponin T (hs-cTnT) values that met criteria (n = 11,477), in particular, those who were admitted (n = 3775). (3) Results: men constituted ~55% of triaged patients who met the rule-out criteria, whether admitted or discharged. Men were more likely to be admitted (33.7% vs. 31.9%, p = 0.04), more commonly with hs-cTnT values between level of detection (LOD, 5 ng/ml) and the 99th percentile (59.4% of all admissions vs. 40.5% for women), whereas women were more likely to be admitted with values < level of blank (LOB, 3 ng/mL; 22.9% vs. 9.2% for men). Thirty-day mortality (1 man and 1 woman) and in-hospital MI (9 men vs. 1 woman) were uncommon among admitted patients, yet resource utilization during 3-4 hospitalization days was substantial for both sexes, with men undergoing coronary angiography (6.8% vs. 2.9%) and revascularization (3.4% vs. 1.1%) more commonly. Long-term survival for both men and women, whether admitted or discharged, was significantly worse for hs-cTnT values between LOD and the 99th percentile, even after adjusting for age and cardiovascular comorbidities. (4) Conclusions: reporting actual hs-cTnT values < 99th percentile allows for better risk stratification, especially for women, possibly closing the sex gap.

5.
Curr Biol ; 33(21): 4611-4623.e4, 2023 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-37774707

RESUMO

For most model organisms in neuroscience, research into visual processing in the brain is difficult because of a lack of high-resolution maps that capture complex neuronal circuitry. The microinsect Megaphragma viggianii, because of its small size and non-trivial behavior, provides a unique opportunity for tractable whole-organism connectomics. We image its whole head using serial electron microscopy. We reconstruct its compound eye and analyze the optical properties of the ommatidia as well as the connectome of the first visual neuropil-the lamina. Compared with the fruit fly and the honeybee, Megaphragma visual system is highly simplified: it has 29 ommatidia per eye and 6 lamina neuron types. We report features that are both stereotypical among most ommatidia and specialized to some. By identifying the "barebones" circuits critical for flying insects, our results will facilitate constructing computational models of visual processing in insects.


Assuntos
Himenópteros , Visão Ocular , Animais , Neurônios/fisiologia , Percepção Visual , Neurópilo , Drosophila
6.
Eur Heart J Qual Care Clin Outcomes ; 9(3): 207-215, 2023 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-36694945

RESUMO

AIMS: Many patients with suspected non-ST-elevation (NSTE) acute coronary syndromes (ACS) are admitted, even those with initial high-sensitivity cardiac troponins (hs-cTn) values who meet rapid rule-out criteria for myocardial infarction (MI). We examined the clinical outcomes, resource utilization, and diagnostic yield of suspected NSTE-ACS patients, who presented with hs-cTnT values meeting these criteria but were nevertheless hospitalized. METHODS AND RESULTS: Applying the 2020 European Society of Cardiology (ESC) rapid rule-out MI criteria, we identified consecutive patients with an initial value of hs-cTnT <5 ng/L or an initial value of ≥5 ng/L but <14 ng/L (99th percentile) and a small increment in a subsequent test, who were nevertheless admitted. The majority (85.4%) of patients presented to the emergency department (ED) with suspected NSTE-ACS had an initial hs-cTnT <99th percentile. We examined 3775 admitted patients out of 11 477 patients who were triaged and met MI rule-out criteria. Only 0.32% (12 patients) of admitted patients experienced index MI or overall death within 30 days. Resource utilization in terms of ED stay, hospital stay, noninvasive and invasive tests was substantial, yet revascularization was uncommon (2.5%). Multivariate adjustment for age, gender, and baseline cardiovascular risk factors demonstrates similar survival of admitted vs. discharged patients (P = 0.88). Initial hs-cTnT even below the 99th percentile provided a prognostic stratification for long term mortality. CONCLUSION: Our findings support a policy of ED discharge of suspected NSTE-ACS patients meeting rapid MI rule-out criteria and subsequent ambulatory evaluation, sparing resource-consuming admissions. In-hospital and ensuing prognosis were better with lower initial hs-cTnT values.


Assuntos
Síndrome Coronariana Aguda , Infarto do Miocárdio , Humanos , Síndrome Coronariana Aguda/diagnóstico , Troponina T , Biomarcadores , Hospitais
7.
Front Cardiovasc Med ; 9: 984952, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36523371

RESUMO

Background: The link between thyroid dysfunction and cardiovascular disease is well established. Hypothyroidism has been significantly associated with increased risk of dyslipidemia, atherosclerosis and heart failure. However, little is known regarding its effect on patients undergoing percutaneous coronary intervention (PCI). Aim: The aim of study was to examine the impact of concomitant hypothyroidism on mortality and major adverse cardiac event (MACE) in patients undergoing PCI. Methods: The Rabin Medical Center PCI registry includes all consecutive patients who have undergone PCI between 2004 and 2020. We identified patients with prior diagnosis of hypothyroidism, and compared rates of mortality and MACE (comprising death, myocardial infarction, target vessel revascularization and/or coronary bypass surgery). Results: Among 28,274 patients, 1,922 (6.8%) were found to have hypothryoidism. These patients were older (70.3 ± 10.4 vs. 66.0 ± 11.8 y.o, P < 0.001) and more likely to be women (34.2% vs. 26.1%, P < 0.001). They had a higher prevalence of atrial fibrillation (10.8% vs. 7.7%, P < 0.001), chronic renal dysfunction (25.1% vs. 18.7%, P = 0.04) and dementia (2.9% vs. 1.8%, P = 0.004). PCI was performed on ACS setting in 52-54% of patients in both groups (p = 0.569). Unadjusted 5-year rates of all-cause mortality (26.9% vs. 20.3%, P < 0.001) and MACE (40.3% vs. 29.4%, P < 0.001) were higher for hypothyroid patients. A propensity match score was able to form 672 matched pairs of HT and control patients, showing similar results. Moreover, following multivariate analysis, TSH as a continuous parameter was associated with a higher risk of mortality and MACE (HR, 1.06 per additional 1 mIU/L; CI, 1.02-1.11; P < 0.001 and HR, 1.07; CI, 1.02-1.12; P < 0.001, respectively) at 5-year follow up. Conclusion: In our study, hypothyroidism confers worse outcomes in patients undergoing PCI. Further research is needed to establish effective ways to mitigate this augmented risk.

8.
Cogn Emot ; 36(8): 1605-1612, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36281536

RESUMO

Reappraisal is an adaptive emotion regulation strategy associated with favourable mental health outcomes. It is unclear whether the adaptive outcomes of habitual reappraisal are associated with better implementation of reappraisal when faced with negative affective situations. The current study aimed to examine whether habitual reappraisal predicts the implementation of instructed reappraisal and to evaluate the potential moderating effects of situational factors, namely - emotional intensity and reappraisal affordance. To address this question, 100 participants reported their habitual reappraisal tendency and were asked to imagine themselves in different hypothetical interpersonal situations. Participants rated emotional intensity levels and reappraisal affordance for each situation, followed by instructions to implement reappraisal. Implementation success was measured by self-reported affect pre-and-post-implementation. Results indicated that habitual reappraisal was associated with greater reappraisal implementation success. While higher intensity scores predicted greater reappraisal implementation success, intensity did not moderate the association between habitual reappraisal and reappraisal implementation success. Reappraisal affordance did not predict reappraisal implementation success, nor did it moderate the association between habitual reappraisal and reappraisal implementation success. Our findings suggest that individual-centred factors play a significant role in reappraisal implementation success, while the effects of situation-centred factors demand further investigation.


Assuntos
Regulação Emocional , Emoções , Humanos , Emoções/fisiologia , Hábitos , Cognição/fisiologia
9.
Neurosurgery ; 90(1): 59-65, 2022 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-34982871

RESUMO

BACKGROUND: Percutaneous cervical cordotomy (PCC), which selectively interrupts ascending nociceptive pathways in the spinal cord, can mitigate severe refractory cancer pain. It has an impressive success rate, with most patients emerging pain-free. Aside from the usual complications of neurosurgical procedures, the risks of PCC include development of contralateral pain, which is less understood. OBJECTIVE: To evaluate whether sensory and pain sensitivity, as measured by quantitative sensory testing (QST), are associated with PCC clinical outcomes. METHODS: Fourteen palliative care cancer patients with severe chronic refractory pain limited mainly to one side of the body underwent comprehensive quantitative sensory testing assessment pre-PPC and post-PCC. They were also queried about maximal pain during the 24 h precordotomy (0-10 numerical pain scale). RESULTS: All 14 patients reported reduced pain postcordotomy, with 7 reporting complete resolution. Four patients reported de novo contralateral pain. Reduced sensitivity in sensory and pain thresholds to heat and mechanical stimuli was recorded on the operated side (P = .028). Sensitivity to mechanical pressure increased on the unaffected side (P = .023), whereas other sensory thresholds were unchanged. The presurgical temporal summation values predicted postoperative contralateral pain (r = 0.582, P = .037). CONCLUSION: The development of contralateral pain in patients postcordotomy for cancer pain might be due to central sensitization. Temporal summation could serve as a potential screening tool to identify those who are most likely at risk to develop contralateral pain. Analysis of PCC affords a unique opportunity to investigate how a specific lesion to the nociceptive system affects pain processes.


Assuntos
Dor do Câncer , Neoplasias , Dor Intratável , Dor do Câncer/cirurgia , Cordotomia/efeitos adversos , Cordotomia/métodos , Humanos , Neoplasias/cirurgia , Limiar da Dor , Dor Intratável/cirurgia
10.
Ultraschall Med ; 43(5): e81-e89, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33316836

RESUMO

PURPOSE: To evaluate the relationship between gastrointestinal (GI) symptoms and transvaginal ultrasound (TVUS) findings suggestive of endometriosis. MATERIALS AND METHODS: A prospective design. Women referred for a diagnostic ultrasound due to suspicion of endometriosis completed a Rome III and Pelvic Floor Distress Inventory (PFDI-20) questionnaire for clinical, GI symptoms, before undergoing TVUS. Endometriosis was diagnosed in the presence of endometriomas and/or deeply infiltrative endometriotic (DIE) lesions. Association between lesion sites and GI symptoms was evaluated by univariate and multivariate analysis. RESULTS: The study included 241 women who presented with: dysmenorrhea (89.6 %), dyspareunia (76.3 %), chronic pelvic pain (77.2 %), dyschezia (66 %), hematochezia (15.4 %), subfertility (24.5 %). GI symptoms were present in 25.3-76.8 % and 5.4-55.6 % of Rome III and PFDI-20 questionnaire responses, respectively. TVUS findings were endometriomas (23.2 %), peritoneal adhesions (46.5 %), uterosacral ligament (26.7 %), retrocervical (11.2 %), rectosigmoid (11.2 %), intestinal (4.6 %), and bladder (0.8 %) involvement, and pouch of Douglas (POD) obliteration (15.4 %). There was a high prevalence of peritoneal adhesions, uterosacral ligament involvement, and rectosigmoid and intestinal nodules on TVUS in women with GI symptoms, up to Chi2 = 9.639 (p = 0.013) on univariate and Chi2 = 8.102 (p = 0.005) on multivariate analysis. CONCLUSION: We observed an almost 10-fold increase in DIE lesions in women with GI symptoms. We suggest that the presence of GI symptoms should prompt a referral for endometriosis evaluation and performance of a dedicated TVUS before invasive gastrointestinal procedures.


Assuntos
Endometriose , Doenças Peritoneais , Endometriose/diagnóstico por imagem , Endometriose/patologia , Feminino , Humanos , Doenças Peritoneais/diagnóstico por imagem , Projetos Piloto , Encaminhamento e Consulta , Sensibilidade e Especificidade , Ultrassonografia/métodos
11.
J Org Chem ; 87(4): 1934-1940, 2022 02 18.
Artigo em Inglês | MEDLINE | ID: mdl-34232659

RESUMO

A highly stereoselective synthesis of a cyclic dinucleotide (CDN) STING agonist containing two chiral thiophosphoramidate linkages is described. These rare yet key functional groups were, for the first time, installed efficiently and with high diastereoselectivity using a specially designed P(V) reagent. By utilizing this strategy, the CDN was prepared in greater than 16-fold higher yield than the prior P(III) approach, with fewer hazardous reagents and chromatographic purifications.


Assuntos
Proteínas de Membrana , Indicadores e Reagentes , Proteínas de Membrana/química
12.
J Clin Med ; 10(13)2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-34279456

RESUMO

The study aimed to perform external validation of the International Ovarian Tumor Analysis (IOTA) classification of adnexal masses as benign or malignant in women with suspected endometrioma. A retrospective study including women referred to an endometriosis tertiary referral center for dedicated transvaginal ultrasound (TVUS). Adnexal masses were evaluated using the IOTA classification simple descriptors, simple rules and expert opinion. The reference standard was definitive histology after mass removal at laparoscopy. In total, 621 women were evaluated and divided into four groups: endometrioma on TVUS and confirmed on surgery (Group 1 = 181), endometrioma on TVUS but other benign cysts on surgery (Group 2 = 9), other cysts on TVUS but endometrioma on surgery (Group 3 = 2), masses classified as other findings or suspicious for malignancy on TVUS and confirmed on surgery (Group 4 = 5 potentially malignant, 11 benign). This gave a sensitivity 98.9%, specificity 64%, positive 95.3% and negative 88.9% predictive values, positive 2.74 and negative 0.02 likelihood ratios and 94.7% overall accuracy. The surgical diagnosis for the five masses suspected to be malignant was: borderline serous tumor (2), borderline mucinous tumor (2), and endometrioid lesion with complex hyperplasia without atypia (1). The conclusions were that the IOTA classification simple descriptors, simple rules and expert opinion performs well for classifying adnexal masses suspected to be endometrioma. The most common potentially malignant masses in these women were borderline ovarian tumors.

13.
iScience ; 24(3): 102140, 2021 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-33665559

RESUMO

Tobacco smoking is a risk factor for several human diseases. Conversely, smoking also reduces the prevalence of Parkinson's disease, whose hallmark is degeneration of substantia nigra dopaminergic neurons (DNs). We use C. elegans as a model to investigate whether tobacco-derived nicotine activates nicotinic acetylcholine receptors (nAChRs) to selectively protect DNs. Using this model, we demonstrate conserved functions of DN-expressed nAChRs. We find that DOP-2, a D3-receptor homolog; MCU-1, a mitochondrial calcium uniporter; PINK-1 (PTEN-induced kinase 1); and PDR-1 (Parkin) are required for nicotine-mediated protection of DNs. Together, our results support involvement of a calcium-modulated, mitochondrial stress-activated PINK1/Parkin-dependent pathway in nicotine-induced neuroprotection. This suggests that nicotine-selective protection of substantia nigra DNs is due to the confluence of two factors: first, their unique vulnerability to mitochondrial stress, which is mitigated by increased mitochondrial quality control due to PINK1 activation, and second, their specific expression of D3-receptors.

14.
Int J Mol Sci ; 21(22)2020 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-33213002

RESUMO

Photoreceptor disc component (PRCD) is a small protein which is exclusively localized to photoreceptor outer segments, and is involved in the formation of photoreceptor outer segment discs. Mutations in PRCD are associated with retinal degeneration in humans, mice, and dogs. The purpose of this work was to identify PRCD-binding proteins in the retina. PRCD protein-protein interactions were identified when implementing the Ras recruitment system (RRS), a cytoplasmic-based yeast two-hybrid system, on a bovine retina cDNA library. An interaction between PRCD and tubby-like protein 1 (TULP1) was identified. Co-immunoprecipitation in transfected mammalian cells confirmed that PRCD interacts with TULP1, as well as with its homolog, TUB. These interactions were mediated by TULP1 and TUB highly conserved C-terminal tubby domain. PRCD localization was altered in the retinas of TULP1- and TUB-deficient mice. These results show that TULP1 and TUB, which are involved in the vesicular trafficking of several photoreceptor proteins from the inner segment to the outer segment, are also required for PRCD exclusive localization to photoreceptor outer segment discs.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas do Olho/metabolismo , Proteínas de Membrana/metabolismo , Células Fotorreceptoras de Vertebrados/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Células COS , Chlorocebus aethiops , Proteínas do Olho/genética , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout
15.
Int Immunopharmacol ; 83: 106381, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32179243

RESUMO

Nicotinic acetylcholine receptors (nAChRs) are ligand-gated ion channels having many functions including inflammation control, as part of the cholinergic anti-inflammatory pathway. Genome wide association studies implicated RIC3, a chaperone of nAChRs, in multiple sclerosis (MS), a neuroinflammatory disease. To understand the involvement of RIC3 in inflammatory diseases we examined its expression, regulation, and function in activated immune cells. Our results show that immune activation leads to dynamic changes in RIC3 expression, in a mouse model of MS and in human lymphocytes and macrophages. We also show similarities in the expression dynamics of RIC3 and CHRNA7, encoding for the α7 nAChR subunit. Homomeric α7 nAChRs were shown to mediate the anti-inflammatory effects of cholinergic agonists. Thus, similarity in expression dynamics between RIC3 and CHRNA7 is suggestive of functional concordance. Indeed, siRNA mediated silencing of RIC3 in a mouse macrophage cell line eliminates the anti-inflammatory effects of cholinergic agonists. Furthermore, we show increased average expression of RIC3 and CHRNA7 in lymphocytes from MS patients, and a strong correlation between expression levels of these two genes in MS patients but not in healthy donors. Together, our results are consistent with a role for RIC3 and for the mechanisms regulating its expression in inflammatory processes and in neuroinflammatory diseases.


Assuntos
Encefalomielite Autoimune Experimental/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Linfócitos/imunologia , Macrófagos/imunologia , Esclerose Múltipla/metabolismo , Inflamação Neurogênica/metabolismo , Receptor Nicotínico de Acetilcolina alfa7/metabolismo , Animais , Anti-Inflamatórios , Células Cultivadas , Colinérgicos , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Transdução de Sinais
16.
J Psychiatr Res ; 115: 21-28, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31082653

RESUMO

Na+, K+-ATPase is an essential membrane transporter. In the brain, the α3 isoform of Na+, K+-ATPase is vital for neuronal function. The enzyme and its regulators, endogenous cardiac steroids (ECS), were implicated in neuropsychiatric disorders. GABAergic neurotransmission was also studied extensively in diseases such as schizophrenia and bipolar disorder (BD). Post mortem brain samples from subjects with depression, schizophrenia or BD and non-psychiatric controls were provided by the Stanley Medical Research Institute. ECS levels were determined by ELISA. Expression levels of the three Na+, K+-ATPase-α isoforms, α1, α2 and α3, were determined by Western blot analysis. The α3 levels in GABAergic neurons in different regions of the brain were quantified by fluorescence immunohistochemistry. The results show that Na+, K+ -ATPase α3 isoform levels were lower in GABAergic neurons in the frontal cortex in BD and schizophrenia as compared with the controls (n = 15 subjects per group). A study on a 'mini-cohort' (n = 3 subjects per group) showed that the α3 isoform levels were also lower in GABAergic neurons in the hippocampus, but not amygdala, of bipolar and schizophrenic subjects. In the temporal cortex, higher Na+, K+ -ATPase α3 protein levels were found in the three psychiatric groups. No significant differences in ECS levels were found in this brain area. This is the first report on the distribution of α3 in specific neurons in the human brain in association with mental illness. These results strengthen the hypothesis for the involvement of Na+, K+ -ATPase in neuropsychiatric diseases.


Assuntos
Transtorno Bipolar/enzimologia , Transtorno Depressivo/enzimologia , Neurônios GABAérgicos/enzimologia , Interneurônios/enzimologia , Córtex Pré-Frontal/enzimologia , Esquizofrenia/enzimologia , ATPase Trocadora de Sódio-Potássio/metabolismo , Bancos de Tecidos , Adulto , Tonsila do Cerebelo/enzimologia , Hipocampo/enzimologia , Humanos , Córtex Pré-Frontal/patologia , Isoformas de Proteínas , Lobo Temporal/enzimologia
17.
Mater Sci Eng C Mater Biol Appl ; 97: 451-460, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30678932

RESUMO

Nanoscale supramolecular systems have been increasingly gaining importance as drug release vehicles due to their ability to target tumor cells. In this work, we have developed a new class of nanoassemblies derived from the phytosterol 24-EpiBrassinolide (EpiB) for the development of nanocarriers for the anticancer drug Doxorubicin (DOX). EpiB is a biocompatible cholesterol mimic, and has inherent apoptotic properties toward cancer cells. Thus, by encapsulating DOX within a nanocarrier with innate anticancer ability we have developed a targeting system that can enhance the uptake and efficacy of DOX in tumor cells. The nanocarriers were formed by self-assembly of EpiB. The morphologies of assemblies formed were dependent upon the concentration of EpiB used. While at low concentrations, spherical nanoassemblies were formed, at higher concentration, lamellar aggregates with birefringence properties were observed. Our results indicated that the drug loaded nanocarriers showed diffusion controlled release of the drug, and demonstrated antiproliferative effects, cellular uptake and were apoptotic against HeLa cervical cancer cells. Furthermore, EpiB loaded DOX enhanced both apoptosis and uptake into the cell's nuclei. These supramolecular assemblies may have potential applications for enhancing efficacy of chemotherapeutic drugs through passive targeting.


Assuntos
Antibióticos Antineoplásicos/química , Doxorrubicina/química , Portadores de Fármacos/química , Nanoestruturas/química , Fitosteróis/química , Antibióticos Antineoplásicos/metabolismo , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Brassinosteroides/química , Doxorrubicina/metabolismo , Doxorrubicina/farmacologia , Liberação Controlada de Fármacos , Células HeLa , Humanos , Microscopia Confocal , Espectroscopia de Infravermelho com Transformada de Fourier , Esteroides Heterocíclicos/química
18.
J Cardiovasc Pharmacol Ther ; 24(1): 78-89, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30033751

RESUMO

Cardiac steroids (CSs), such as ouabain and digoxin, increase the force of contraction of heart muscle and are used for the treatment of congestive heart failure (CHF). However, their small therapeutic window limits their use. It is well established that Na+, K+-ATPase inhibition mediates CS-induced increase in heart contractility. Recently, the involvement of intracellular signal transduction was implicated in this effect. The aim of the present study was to test the hypothesis that combined treatment with ouabain and Akt inhibitor (MK-2206) augments ouabain-induced inotropy in mammalian models. We demonstrate that the combined treatment led to an ouabain-induced increase in contractility at concentrations at which ouabain alone was ineffective. This was shown in 3 experimental systems: neonatal primary rat cardiomyocytes, a Langendorff preparation, and an in vivo myocardial infarction induced by left anterior descending coronary artery (LAD) ligation. Furthermore, cell viability experiments revealed that this treatment protected primary cardiomyocytes from MK-2206 toxicity and in vivo reduced the size of scar tissue 10 days post-LAD ligation. We propose that Akt activity imposes a constant inhibitory force on muscle contraction, which is attenuated by low concentrations of MK-2206, resulting in potentiation of the ouabain effect. This demonstration of the increase in the CS effect advocates the development of the combined treatment in CHF.


Assuntos
Cardiotônicos/farmacologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Contração Miocárdica/efeitos dos fármacos , Infarto do Miocárdio/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Ouabaína/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Função Ventricular Esquerda/efeitos dos fármacos , Animais , Células Cultivadas , Modelos Animais de Doenças , Sinergismo Farmacológico , Quimioterapia Combinada , Preparação de Coração Isolado , Masculino , Infarto do Miocárdio/enzimologia , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Wistar , Transdução de Sinais
19.
Brain Res Bull ; 137: 356-362, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29374602

RESUMO

OBJECTIVES: Bipolar disorder (BD) is a severe mental illness characterized by episodes of mania and depression. Numerous studies have implicated the involvement of endogenous cardiac steroids (CS), and their receptor, Na+, K+ -ATPase, in BD. The aim of the present study was to examine the role of brain oxidative stress in the CS-induced behavioral effects in mice. METHODS: Amphetamine (AMPH)-induced hyperactivity, assessed in the open-field test, served as a model for manic-like behavior in mice. A reduction in brain CS was obtained by specific and sensitive anti-ouabain antibodies. The level of oxidative stress was tested in the hippocampus and frontal cortex by measuring the activity of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx), as well as the levels of antioxidant non-protein thiols (NPSH) and oxidative damage biomarkers thiobarbituric acid reactive substances (TBARS) and protein carbonyl (PC). RESULTS: AMPH administration resulted in a marked hyperactivity and increased oxidative stress, as manifested by increased SOD activity, decreased activities of CAT and GPx, reduced levels of NPSH and increased levels of TBARS and PC. The administration of anti-ouabain antibodies, which reduced the AMPH-induced hyperactivity, protected against the concomitant oxidative stress in the brain. CONCLUSIONS: Our results demonstrate that oxidative stress participates in the effects of endogenous CS on manic-like behavior induced by AMPH. These finding support the notion that CS and oxidative stress may be associated with the pathophysiology of mania and BD.


Assuntos
Anfetamina/toxicidade , Transtorno Bipolar/induzido quimicamente , Encéfalo/efeitos dos fármacos , Estimulantes do Sistema Nervoso Central/toxicidade , Fármacos Neuroprotetores/farmacologia , Ouabaína/antagonistas & inibidores , Transtornos Relacionados ao Uso de Anfetaminas/tratamento farmacológico , Transtornos Relacionados ao Uso de Anfetaminas/metabolismo , Animais , Anticorpos/administração & dosagem , Antioxidantes/farmacologia , Transtorno Bipolar/metabolismo , Encéfalo/metabolismo , Modelos Animais de Doenças , Masculino , Camundongos Endogâmicos BALB C , Atividade Motora/efeitos dos fármacos , Atividade Motora/fisiologia , Ouabaína/imunologia , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/fisiologia , Distribuição Aleatória
20.
Retin Cases Brief Rep ; 11(4): 310-315, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27315323

RESUMO

PURPOSE: To demonstrate unusual retinal findings in a patient with progressive renal failure due to idiopathic monoclonal immunoglobulin light chain deposition disease, using multimodal imaging. METHODS: Observational case report of a 43-year-old white man with renal failure due to light chain deposition disease. His course over 6 years was documented with multimodal imaging including fundus photography, fundus autofluorescence, fluorescein angiography, and spectral domain optical coherence tomography. Additional evaluations included ocular ultrasound, electroretinography, positron emission tomography, serum protein electrophoreses, skeletal surveys to detect osteolytic lesions, and renal, liver, and rectal biopsies in search of amyloid. RESULTS: The patient's ocular course mirrored the severity of his renal dysfunction for which he required a renal transplant. Changes observed in the native kidney recurred in the transplant 2 years later, as evidenced by immunohistochemistry, revealing thick linear deposits of kappa chains, with no complement, overlying the glomerular basement membrane. The systemic workup was negative for amyloid but showed an overwhelming ratio of kappa to lambda light chains on serum protein electrophoreses and no clinical signs of plasma cell dyscrasias, all consistent with idiopathic light chain deposition disease. The patient presented with a generalized, bilateral "leopard-spot" fundus appearance on fundus autofluorescence, striking globular subretinal deposits on spectral domain optical coherence tomography, and subfoveal subretinal fluid without retinal pigment epithelium detachment or choroidal effusions. The subfoveal fluid did not respond to intravitreal injections of antiangiogenic agents or steroids but resolved after renal transplantation. A temporary posttransplant visual improvement was associated with lessening of the subretinal drusenoid deposits demonstrated by multimodal imaging. The terminal vision deterioration was associated with amorphous, vitelliform-like material deposition and atrophic changes. CONCLUSION: This case may illustrate a resemblance in the renal glomerulus basement membrane and retinal pigment epithelium-Bruch membrane complex, because the authors observed deposits of excess monoclonal kappa chains manifesting as extracellular, proteinaceous aggregates on the basement membrane of the glomerulus, and striking, globular subretinal deposits that overlay a thickened retinal pigment epithelium-Bruch membrane complex. The ocular lesions' refractoriness to intravitreal treatments could be attributed to the fact that they represent proteinaceous aggregates similar to those documented in the glomeruli. This is the first report of generalized, large, subretinal drusenoid deposits and their course, as documented through multimodal imaging, paralleling the chronology of systemic changes in a patient with light chain deposition disease.


Assuntos
Cadeias Leves de Imunoglobulina/análise , Paraproteinemias/complicações , Doenças Retinianas/etiologia , Adulto , Humanos , Falência Renal Crônica/complicações , Masculino
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