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1.
Cureus ; 16(8): e66198, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39233973

RESUMO

Breast cancer is the second most common cancer globally, with 2.3 million new cases annually, constituting 11.6% of all cancer cases. It is also the fourth leading cause of cancer deaths, claiming 670,000 lives a year. This high incidence of breast cancer morbidity worldwide has increased the urgent need for standardized and adequate screening methods, including clinical breast examination, self-breast examination, and mammography screening tests for non-symptomatic individuals. Mammography is considered the gold standard for breast cancer screening, with early randomized control trials showing significant reductions in mortality rates in women aged 50 and over (International Agency for Research on Cancer and American College of Radiology). Despite this, discrepancies in mammography practices across different healthcare settings regarding adherence to international standards raise concerns. A comprehensive review of the vast literature looking at the practices and norms of mammography screening worldwide highlighted several domains that present limitations to screening. These include epidemiological data deficits, lack of educational training offered to radiographers and varied image quality indices, exposure technique, method of breast compression, dose calculation, reference levels, screening frequency intervals, and diverse distribution of resources, particularly in developing countries. These factors shed light on the substantial discrepancies in the implementation and efficacy of screening programs, underscoring the necessity for future research endeavors to collaborate in creating coherent, standardized, evidence-based guidelines. Addressing these issues can enhance the feasibility, sensitivity, and accessibility of screening programs, resulting in favorable impacts on the early diagnosis and survival of breast cancer on a global scale.

2.
Cureus ; 16(7): e63889, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39104992

RESUMO

Esophageal varices are life-threatening complications in which the enlargement of the esophageal veins causes bleeding and reduces blood flow to the esophagus. They are complications caused by portal hypertension, renal failure, hepatic dysfunction, and infection. The leading cause of esophageal varices is cirrhosis, as patients with this disease are more susceptible to forming esophageal varices. Bleeding episodes occur due to the rupture of the blood vessels. We present the case of a 45-year-old male patient in the hospital with a history of chronic alcohol use and clinical symptoms of hematemesis, a distended abdomen, and melena. The patient experienced mild symptoms of giddiness and dizziness after undergoing various radiological investigations, laboratory tests, ultrasonography (USG), and CT scans. USG diagnosed portal hypertension, gross ascites, pleural effusion, and hepatosplenomegaly. A CT scan diagnosed the patient with esophageal varices and testicular carcinoma. Laboratory tests diagnosed anemia. The treatment plan included oral and intravenous iron supplements, blood transfusions, vitamin B12, folate supplements, and nonselective beta-blockers to manage portal hypertension and reduce variceal bleeding risk. During acute bleeding episodes, vasoconstrictors and endoscopic band ligation were employed. Regular endoscopies and hepatic venous catheterization were conducted to monitor and manage the condition. Follow-up included regular assessments of hemoglobin levels, iron status, liver function tests, and periodic endoscopies. The patient's adherence to beta-blockers was closely monitored. Esophageal varices, often resulting from portal hypertension because of cirrhosis, require early diagnosis and a combination of pharmacological and endoscopic treatments to prevent complications. Advances in treatment have reduced mortality rates, but effective management of portal hypertension and liver dysfunction remains crucial.

3.
Eur Radiol Exp ; 8(1): 46, 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38594558

RESUMO

BACKGROUND: Monitoring pyruvate metabolism in the spleen is important for assessing immune activity and achieving successful radiotherapy for cervical cancer due to the significance of the abscopal effect. We aimed to explore the feasibility of utilizing hyperpolarized (HP) [1-13C]-pyruvate magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) to evaluate pyruvate metabolism in the human spleen, with the aim of identifying potential candidates for radiotherapy in cervical cancer. METHODS: This prospective study recruited six female patients with cervical cancer (median age 55 years; range 39-60) evaluated using HP [1-13C]-pyruvate MRI/MRS at baseline and 2 weeks after radiotherapy. Proton (1H) diffusion-weighted MRI was performed in parallel to estimate splenic cellularity. The primary outcome was defined as tumor response to radiotherapy. The Student t-test was used for comparing 13C data between the groups. RESULTS: The splenic HP [1-13C]-lactate-to-total carbon (tC) ratio was 5.6-fold lower in the responders than in the non-responders at baseline (p = 0.009). The splenic [1-13C]-lactate-to-tC ratio revealed a 1.7-fold increase (p = 0.415) and the splenic [1-13C]-alanine-to-tC ratio revealed a 1.8-fold increase after radiotherapy (p = 0.482). The blood leukocyte differential count revealed an increased proportion of neutrophils two weeks following treatment, indicating enhanced immune activity (p = 0.013). The splenic apparent diffusion coefficient values between the groups were not significantly different. CONCLUSIONS: This exploratory study revealed the feasibility of HP [1-13C]-pyruvate MRS of the spleen for evaluating baseline immune potential, which was associated with clinical outcomes of cervical cancer after radiotherapy. TRIAL REGISTRATION: ClinicalTrials.gov NCT04951921 , registered 7 July 2021. RELEVANCE STATEMENT: This prospective study revealed the feasibility of using HP 13C MRI/MRS for assessing pyruvate metabolism of the spleen to evaluate the patients' immune potential that is associated with radiotherapeutic clinical outcomes in cervical cancer. KEY POINTS: • Effective radiotherapy induces abscopal effect via altering immune metabolism. • Hyperpolarized 13C MRS evaluates patients' immune potential non-invasively. • Pyruvate-to-lactate conversion in the spleen is elevated following radiotherapy.


Assuntos
Ácido Pirúvico , Neoplasias do Colo do Útero , Humanos , Feminino , Pessoa de Meia-Idade , Ácido Pirúvico/metabolismo , Neoplasias do Colo do Útero/diagnóstico por imagem , Neoplasias do Colo do Útero/radioterapia , Estudos Prospectivos , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13/métodos , Lactatos
4.
Cancers (Basel) ; 16(8)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38672634

RESUMO

There is growing recognition of early-onset gastrointestinal (GI) malignancies in young adults < 50 years of age. While much of the literature has emphasized colorectal cancer, these also include esophageal, gastric, liver, pancreatic, and biliary tract malignancies. Various factors, including lifestyle, hereditary, and environmental elements, have been proposed to explain the rising incidence of GI malignancies in the younger population. This review aims to provide an overview of the recent literature, including global trends and information regarding genetic and environmental risk factors.

5.
Magn Reson Med ; 91(6): 2204-2228, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38441968

RESUMO

MRI with hyperpolarized (HP) 13C agents, also known as HP 13C MRI, can measure processes such as localized metabolism that is altered in numerous cancers, liver, heart, kidney diseases, and more. It has been translated into human studies during the past 10 years, with recent rapid growth in studies largely based on increasing availability of HP agent preparation methods suitable for use in humans. This paper aims to capture the current successful practices for HP MRI human studies with [1-13C]pyruvate-by far the most commonly used agent, which sits at a key metabolic junction in glycolysis. The paper is divided into four major topic areas: (1) HP 13C-pyruvate preparation; (2) MRI system setup and calibrations; (3) data acquisition and image reconstruction; and (4) data analysis and quantification. In each area, we identified the key components for a successful study, summarized both published studies and current practices, and discuss evidence gaps, strengths, and limitations. This paper is the output of the "HP 13C MRI Consensus Group" as well as the ISMRM Hyperpolarized Media MR and Hyperpolarized Methods and Equipment study groups. It further aims to provide a comprehensive reference for future consensus, building as the field continues to advance human studies with this metabolic imaging modality.


Assuntos
Imageamento por Ressonância Magnética , Ácido Pirúvico , Humanos , Ácido Pirúvico/metabolismo , Imageamento por Ressonância Magnética/métodos , Processamento de Imagem Assistida por Computador , Coração , Fígado/diagnóstico por imagem , Fígado/metabolismo , Isótopos de Carbono/metabolismo
6.
Cardiovasc Diabetol ; 22(1): 294, 2023 10 27.
Artigo em Inglês | MEDLINE | ID: mdl-37891673

RESUMO

BACKGROUND: The PI3K/AKT pathway transduces the majority of the metabolic actions of insulin. In addition to cytosolic targets, insulin-stimulated phospho-AKT also translocates to mitochondria in the myocardium. Mouse models of diabetes exhibit impaired mitochondrial AKT signaling but the implications of this on cardiac structure and function is unknown. We hypothesized that loss of mitochondrial AKT signaling is a critical step in cardiomyopathy and reduces cardiac oxidative phosphorylation. METHODS: To focus our investigation on the pathophysiological consequences of this mitochondrial signaling pathway, we generated transgenic mouse models of cardiac-specific, mitochondria-targeting, dominant negative AKT1 (CAMDAKT) and constitutively active AKT1 expression (CAMCAKT). Myocardial structure and function were examined using echocardiography, histology, and biochemical assays. We further investigated the underlying effects of mitochondrial AKT1 on mitochondrial structure and function, its interaction with ATP synthase, and explored in vivo metabolism beyond the heart. RESULTS: Upon induction of dominant negative mitochondrial AKT1, CAMDAKT mice developed cardiac fibrosis accompanied by left ventricular hypertrophy and dysfunction. Cardiac mitochondrial oxidative phosphorylation efficiency and ATP content were reduced, mitochondrial cristae structure was lost, and ATP synthase structure was compromised. Conversely, CAMCAKT mice were protected against development of diabetic cardiomyopathy when challenged with a high calorie diet. Activation of mitochondrial AKT1 protected cardiac function and increased fatty acid uptake in myocardium. In addition, total energy expenditure was increased in CAMCAKT mice, accompanied by reduced adiposity and reduced development of fatty liver. CONCLUSION: CAMDAKT mice modeled the effects of impaired mitochondrial signaling which occurs in the diabetic myocardium. Disruption of this pathway is a key step in the development of cardiomyopathy. Activation of mitochondrial AKT1 in CAMCAKT had a protective role against diabetic cardiomyopathy as well as improved metabolism beyond the heart.


Assuntos
Diabetes Mellitus , Cardiomiopatias Diabéticas , Proteínas Proto-Oncogênicas c-akt , Animais , Camundongos , Trifosfato de Adenosina/metabolismo , Diabetes Mellitus/metabolismo , Cardiomiopatias Diabéticas/diagnóstico por imagem , Cardiomiopatias Diabéticas/etiologia , Cardiomiopatias Diabéticas/metabolismo , Metabolismo Energético , Insulina/farmacologia , Camundongos Transgênicos , Mitocôndrias Cardíacas/metabolismo , Miocárdio/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo
7.
ArXiv ; 2023 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-37731660

RESUMO

MRI with hyperpolarized (HP) 13C agents, also known as HP 13C MRI, can measure processes such as localized metabolism that is altered in numerous cancers, liver, heart, kidney diseases, and more. It has been translated into human studies during the past 10 years, with recent rapid growth in studies largely based on increasing availability of hyperpolarized agent preparation methods suitable for use in humans. This paper aims to capture the current successful practices for HP MRI human studies with [1-13C]pyruvate - by far the most commonly used agent, which sits at a key metabolic junction in glycolysis. The paper is divided into four major topic areas: (1) HP 13C-pyruvate preparation, (2) MRI system setup and calibrations, (3) data acquisition and image reconstruction, and (4) data analysis and quantification. In each area, we identified the key components for a successful study, summarized both published studies and current practices, and discuss evidence gaps, strengths, and limitations. This paper is the output of the "HP 13C MRI Consensus Group" as well as the ISMRM Hyperpolarized Media MR and Hyperpolarized Methods & Equipment study groups. It further aims to provide a comprehensive reference for future consensus building as the field continues to advance human studies with this metabolic imaging modality.

8.
Altern Lab Anim ; 51(4): 263-288, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37282515

RESUMO

Animal experimentation has been integral to drug discovery and development and safety assessment for many years, since it provides insights into the mechanisms of drug efficacy and toxicity (e.g. pharmacology, pharmacokinetics and pharmacodynamics). However, due to species differences in physiology, metabolism and sensitivity to drugs, the animal models can often fail to replicate the effects of drugs and chemicals in human patients, workers and consumers. Researchers across the globe are increasingly applying the Three Rs principles by employing innovative methods in research and testing. The Three Rs concept focuses on: the replacement of animal models (e.g. with in vitro and in silico models or human studies), on the reduction of the number of animals required to achieve research objectives, and on the refinement of existing experimental practices (e.g. eliminating distress and enhancing animal wellbeing). For the last two years, Oncoseek Bio-Acasta Health, a 3-D cell culture-based cutting-edge translational biotechnology company, has organised an annual International Conference on 3Rs Research and Progress. This series of global conferences aims to bring together researchers with diverse expertise and interests, and provides a platform where they can share and discuss their research to promote practices according to the Three Rs principles. In November 2022, the 3rd international conference, Advances in Animal Models and Cutting-Edge Research in Alternatives, took place at the GITAM University in Vishakhapatnam (AP, India) in a hybrid format (i.e. online and in-person). These conference proceedings provide details of the presentations, which were categorised under five different topic sessions. It also describes a special interactive session on in silico strategies for preclinical research in oncology, which was held at the end of the first day.


Assuntos
Experimentação Animal , Animais , Humanos , Modelos Animais , Descoberta de Drogas , Índia , Alternativas aos Testes com Animais
9.
Macromol Biosci ; 23(10): e2300075, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37249127

RESUMO

Fibrosis of the filtering bleb is one of the main causes of failure after bleb-forming glaucoma surgery. Intraoperative application of mitomycin C (MMC) is the current gold standard to reduce the fibrotic response. However, MMC is cytotoxic and one-time application is often insufficient. A sustained-release drug delivery system (DDS), loaded with MMC, may be less cytotoxic and equally or more effective. Two degradable (polycaprolactone (PCL) and polylactic-co-glycolic acid (PLGA)) MMC-loaded DDSs are developed. Release kinetics are first assessed in vitro followed by rabbit implants in conjunction with the PRESERFLO MicroShunt. As a control, the MicroShunt is implanted with adjunctive use of a MMC solution. Rabbits are euthanized at postoperative day (POD) 28 and 90. The PLGA and PCL DDSs release (on average) 99% and 75% of MMC, respectively. All groups show functioning blebs until POD 90. Rabbits implanted with a DDS show more inflammation with avascular thin-walled blebs when compared to the control. However, collagen is more loosely arranged. The PLGA DDS shows less inflammation, less foreign body response (FBR), and more complete degradation at POD 90 when compared to the PCL DDS. Further optimization with regard to dosage is required to reduce side effects to the conjunctiva.

10.
ACS Appl Polym Mater ; 4(8): 6148-6155, 2022 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-35991304

RESUMO

Using paperboard as packaging material is more sustainable than using plastic. To be a viable replacement, however, the barrier properties of paperboard need to be improved. Applying a waterborne barrier coating for both oil and water is an attractive method to improve the barrier performance of paperboard food packaging. However, not much is known about the oil and water barrier properties and penetration pathways of such coatings. Here, an alkali-soluble resin (ASR)-stabilized waterborne emulsion polymer was prepared and applied on untreated paperboard. Its performance as oil and water barrier coating was investigated, and the penetration pathways for both oil and water through the coating are discussed. The presence of surface defects in the coating applied on the paperboard strongly affects both the oil and water barrier properties, but the coating's morphology and chemical nature only play a major role in the water barrier performance. The optimal barrier performance for oil and water was achieved when adding 5 wt % isopropanol (IPA) to the dispersion and applying two coating layers on paperboard. The IPA improves film formation and reduces the number of surface defects, which is explained by a more favorable spreading coefficient of the coating over the paperboard substrate. These insights will help to improve the oil and water barrier properties of polymer-coated paperboard for more sustainable packaging applications.

11.
Membranes (Basel) ; 12(8)2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36005721

RESUMO

The effect of layer spacing and halogenation on the gas separation performances of free-standing smectic LC polymer membranes is being investigated by molecular engineering. LC membranes with various layer spacings and halogenated LCs were fabricated while having a planar aligned smectic morphology. Single permeation and sorption data show a correlation between gas diffusion and layer spacing, which results in increasing gas permeabilities with increasing layer spacing while the ideal gas selectivity of He over CO2 or He over N2 decreases. The calculated diffusion coefficients show a 6-fold increase when going from membranes with a layer spacing of 31.9 Å to membranes with a layer spacing of 45.2 Å, demonstrating that the layer spacing in smectic LC membranes mainly affects the diffusion of gasses rather than their solubility. A comparison of gas sorption and permeation performances of smectic LC membranes with and without halogenated LCs shows only a limited effect of LC halogenation by a slight increase in both solubility and diffusion coefficients for the membranes with halogenated LCs, resulting in a slightly higher gas permeation and increased ideal gas selectivities towards CO2. These results show that layer spacing plays an important role in the gas separation performances of smectic LC polymer membranes.

12.
Cureus ; 14(6): e26427, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35915695

RESUMO

INTRODUCTION: The Surgical Care Improvement Project (SCIP) added the SCIP-Inf-10 measure to mandate that all surgical patients have perioperative temperature management to reduce surgical site infection. While the basis of this measure originated in colorectal surgery, we hypothesized that this would also apply to thoracic surgery patients. METHODS: This was a retrospective single-center pilot study reviewing two years of thoracic surgery cases for the incidence and duration of hypothermia during the operation and surgical site infection occurring within 30 days. Hypothermia was defined as a core temperature of < 36° C.  Results: A total of 317 patients were included in the study. Sixty-two percent of patients were identified as hypothermic. The average intraoperative temperature was 35.4°C ± 0.8°C in the hypothermic group and 36.4°C ± 0.3°C in the normothermic group. There were four surgical site infections in the study with three cases from the <36°C group (p = 1). There was no difference in average post-anesthesia care unit length of stay between the groups. The average hospital length of stay was 5.5 ± 5.2 days for the hypothermic group and 8.6 ± 12.8 days for the normothermic group (p=0.0024). CONCLUSION: Perioperative hypothermia was common in thoracic surgery and did not have a negative impact on surgical site infection.

13.
N Am Spine Soc J ; 9: 100097, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35141661

RESUMO

The ability to navigate the anterior lumbar disc space may improve clinical outcomes and implant longevity. However, no robotic navigation systems are presently authorized by the U.S. Food and Drug Administration to assist with anterior retroperitoneal lumbar interbody surgery. Furthermore, no studies to date have investigated such an application of this technology. This study examines the application of robotic navigation to anterior lumbar total disc replacement surgery to improve retroperitoneal exposure and orientation of the anterior lumbar spine, enhance coronal plane centralization of the implant, optimize surgical trajectory, and mitigate radiologic exposure. Postoperative outcomes of a small cohort of patients undergoing anterior lumbar total disc replacement surgery using robotic navigation were analyzed. The results of the study revealed that a modified use of the aforementioned robot-assisted surgical technology enhances coronal plane centralization and trajectory, all while mitigating radiologic exposure, resulting in more accurate placement of the implant within the intervertebral space at each level.

14.
Drug Metab Dispos ; 50(2): 140-149, 2022 02.
Artigo em Inglês | MEDLINE | ID: mdl-34750194

RESUMO

We report here a novel in vitro experimental system, the metabolism-dependent cytotoxicity assay (MDCA), for the definition of the roles of hepatic drug metabolism in toxicity. MDCA employs permeabilized cofactor-supplemented cryopreserved human hepatocytes (MetMax Human Hepatocytes, MMHH), as an exogenous metabolic activating system, and human embryonic kidney 293 (HEK293) cells, a cell line devoid of drug-metabolizing enzyme activity, as target cells for the quantification of drug toxicity. The assay was performed in the presence and absence of cofactors for key drug metabolism pathways known to play key roles in drug toxicity: NADPH/NAD+ for phase 1 oxidation, uridine 5'-diphosphoglucuronic acid (UDPGA) for uridine 5'-diphospho-glucuronosyltransferase (UGT) mediated glucuronidation, 3'-phosphoadenosine-5'-phosphosulfate (PAPS) for cytosolic sulfotransferase (SULT) mediated sulfation, and glutathione (GSH) for glutathione S-transferase (GST) mediated GSH conjugation. Six drugs with clinically significant hepatoxicity, resulting in liver failure or a need for liver transplantation: acetaminophen, amiodarone, cyclophosphamide, ketoconazole, nefazodone, and troglitazone were evaluated. All six drugs exhibited cytotoxicity enhancement by NADPH/NAD+, suggesting metabolic activation via phase 1 oxidation. Attenuation of cytotoxicity by UDPGA was observed for acetaminophen, ketoconazole, and troglitazone, by PAPS for acetaminophen, ketoconazole, and troglitazone, and by GSH for all six drugs. Our results suggest that MDCA can be applied toward the elucidation of metabolic activation and detoxification pathways, providing information that can be applied in drug development to guide structure optimization to reduce toxicity and to aid the assessment of metabolism-based risk factors for drug toxicity. GSH detoxification represents an endpoint for the identification of drugs forming cytotoxic reactive metabolites, a key property of drugs with idiosyncratic hepatotoxicity. SIGNIFICANCE STATEMENT: Application of the metabolism-dependent cytotoxicity assay (MDCA) for the elucidation of the roles of metabolic activation and detoxification pathways in drug toxicity may provide information to guide structure optimization in drug development to reduce hepatotoxic potential and to aid the assessment of metabolism-based risk factors. Glutathione (GSH) detoxification represents an endpoint for the identification of drugs forming cytotoxic reactive metabolites that may be applied toward the evaluation of idiosyncratic hepatotoxicity.


Assuntos
Amiodarona , Doença Hepática Induzida por Substâncias e Drogas , Acetaminofen/metabolismo , Ativação Metabólica , Amiodarona/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/metabolismo , Ciclofosfamida/metabolismo , Sistema Enzimático do Citocromo P-450/metabolismo , Glutationa/metabolismo , Células HEK293 , Hepatócitos/metabolismo , Humanos , Cetoconazol/metabolismo , Piperazinas , Triazóis , Troglitazona
15.
Chem Mater ; 33(21): 8323-8333, 2021 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-34776611

RESUMO

To prevent greenhouse emissions into the atmosphere, separations like CO2/CH4 and CO2/N2 from natural gas, biogas, and flue gasses are crucial. Polymer membranes gained a key role in gas separations over the past decades, but these polymers are often not organized at a molecular level, which results in a trade-off between permeability and selectivity. In this work, the effect of molecular order and orientation in liquid crystals (LCs) polymer membranes for gas permeation is demonstrated. Using the self-assembly of polymerizable LCs to prepare membranes ensures control over the supramolecular organization and alignment of the building blocks at a molecular level. Robust freestanding LC membranes were fabricated that have various, distinct morphologies (isotropic, nematic cybotactic, and smectic C) and alignment (planar and homeotropic), while using the same chemical composition. Single gas permeation data show that the permeability decreases with increasing molecular order while the ideal gas selectivity of He and CO2 over N2 increases tremendously (36-fold for He/N2 and 21-fold for CO2/N2) when going from randomly ordered to the highly ordered smectic C morphology. The calculated diffusion coefficients showed a 10-fold decrease when going from randomly ordered membranes to ordered smectic C membranes. It is proposed that with increasing molecular order, the free volume elements in the membrane become smaller, which hinders gasses with larger kinetic diameters (Ar, N2) more than gasses with smaller kinetic diameters (He, CO2), inducing selectivity. Comparison of gas sorption and permeation performances of planar and homeotropic aligned smectic C membranes shows the effect of molecular orientation by a 3-fold decrease of the diffusion coefficient of homeotropic aligned smectic C membranes resulting in a diminished gas permeation and increased ideal gas selectivities. These results strongly highlight the importance of molecular order and orientation in LC polymer membranes for gas separation.

16.
Metabolites ; 11(8)2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34436459

RESUMO

Alterations in metabolism following radiotherapy affect therapeutic efficacy, although the mechanism underlying such alterations is unclear. A new imaging technique-named dynamic nuclear polarization (DNP) carbon-13 magnetic resonance imaging (MRI)-probes the glycolytic flux in a real-time, dynamic manner. The [1-13C]pyruvate is transported by the monocarboxylate transporter (MCT) into cells and converted into [1-13C]lactate by lactate dehydrogenase (LDH). To capture the early glycolytic alterations in the irradiated cancer and immune cells, we designed a preliminary DNP 13C-MRI study by using hyperpolarized [1-13C]pyruvate to study human FaDu squamous carcinoma cells, HMC3 microglial cells, and THP-1 monocytes before and after irradiation. The pyruvate-to-lactate conversion rate (kPL [Pyr.]) calculated by kinetic modeling was used to evaluate the metabolic alterations. Western blotting was performed to assess the expressions of LDHA, LDHB, MCT1, and MCT4 proteins. Following irradiation, the pyruvate-to-lactate conversion rates on DNP 13C-MRI were significantly decreased in the FaDu and the HMC3 cells but increased in the THP-1 cells. Western blot analysis confirmed the similar trends in LDHA and LDHB expression levels. In conclusion, DNP 13C-MRI non-invasively captured the different glycolytic alterations among cancer and immune systems in response to irradiation, implying its potential for clinical use in the future.

17.
J Neurooncol ; 152(3): 551-557, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33740165

RESUMO

BACKGROUND: Stereotactic radiosurgery (SRS) is used to manage intracranial metastases in a significant fraction of patients. Local progression after SRS can often only be detected with increased volume of enhancement on serial MRI scans which may lag true progression by weeks or months. METHODS: Patients with intracranial metastases (N = 11) were scanned using hyperpolarized [Formula: see text]C MRI prior to treatment with stereotactic radiosurgery (SRS). The status of each lesion was then recorded at six months post-treatment follow-up (or at the time of death). RESULTS: The positive predictive value of [Formula: see text]C-lactate signal, measured pre-treatment, for prediction of progression of intracranial metastases at six months post-treatment with SRS was 0.8 [Formula: see text], and the AUC from an ROC analysis was 0.77 [Formula: see text]. The distribution of [Formula: see text]C-lactate z-scores was different for intracranial metastases from different primary cancer types (F = 2.46, [Formula: see text]). CONCLUSIONS: Hyperpolarized [Formula: see text]C imaging has potential as a method for improving outcomes for patients with intracranial metastases, by identifying patients at high risk of treatment failure with SRS and considering other therapeutic options such as surgery.


Assuntos
Neoplasias Encefálicas , Radiocirurgia , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/radioterapia , Neoplasias Encefálicas/cirurgia , Humanos , Lactatos , Imageamento por Ressonância Magnética , Estudos Retrospectivos
18.
J Pharm Sci ; 110(1): 376-387, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33122051

RESUMO

Hepatic uptake clearance has been measured in suspended human hepatocytes (SHH). Plated human hepatocytes (PHH) after short-term culturing are increasingly employed to study hepatic transport driven mainly by its higher throughput. To know pros/cons of both systems, the hepatic uptake clearances of several organic anion transporting polypeptide 1B substrates were compared between PHH and SHH by determining the initial uptake velocities or through dynamic model-based analyses. For cerivastatin, pitavastatin and rosuvastatin, initial uptake clearances (PSinf) obtained using PHH were comparable to those using SHH, while cell-to-medium concentration (C/M) ratios were 2.7- to 5.4-fold higher. For pravastatin and dehydropravastatin, hydrophilic compounds with low uptake/cellular binding, their PSinf and C/M ratio in PHH were 1.8- to 3.2-fold lower than those in SHH. These hydrophilic substrates are more prone to wash-off during the uptake study using PHH, which may explain the apparently lower uptake than SHH. The C/M ratios obtained using PHH were stable over an extended time, making PHH suitable to estimate the C/M ratios and hepatocyte-to-medium unbound concentration ratios (Kp,uu). In conclusion, PHH is useful in evaluating hepatic uptake/efflux clearances and Kp,uu of OATP1B substrates in a high-throughput manner, however, a caution is warranted for hydrophilic drugs with low uptake/cellular binding.


Assuntos
Hepatócitos , Transportadores de Ânions Orgânicos , Transporte Biológico , Hepatócitos/metabolismo , Humanos , Fígado/metabolismo , Transportadores de Ânions Orgânicos/metabolismo , Pravastatina/metabolismo
19.
Commun Biol ; 3(1): 703, 2020 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-33239738

RESUMO

Restless legs syndrome (RLS) is a common neurological sensorimotor disorder often described as an unpleasant sensation associated with an urge to move the legs. Here we report findings from a meta-analysis of genome-wide association studies of RLS including 480,982 Caucasians (cases = 10,257) and a follow up sample of 24,977 (cases = 6,651). We confirm 19 of the 20 previously reported RLS sequence variants at 19 loci and report three novel RLS associations; rs112716420-G (OR = 1.25, P = 1.5 × 10-18), rs10068599-T (OR = 1.09, P = 6.9 × 10-10) and rs10769894-A (OR = 0.90, P = 9.4 × 10-14). At four of the 22 RLS loci, cis-eQTL analysis indicates a causal impact on gene expression. Through polygenic risk score for RLS we extended prior epidemiological findings implicating obesity, smoking and high alcohol intake as risk factors for RLS. To improve our understanding, with the purpose of seeking better treatments, more genetics studies yielding deeper insights into the disease biology are needed.


Assuntos
Predisposição Genética para Doença , Polimorfismo de Nucleotídeo Único/genética , Síndrome das Pernas Inquietas , Adulto , Idoso , Predisposição Genética para Doença/epidemiologia , Predisposição Genética para Doença/genética , Estudo de Associação Genômica Ampla , Humanos , Desequilíbrio de Ligação , Pessoa de Meia-Idade , Síndrome das Pernas Inquietas/epidemiologia , Síndrome das Pernas Inquietas/genética
20.
R Soc Open Sci ; 7(7): 200580, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32874649

RESUMO

Corrosion is clearly one of the more common causes of materials failure in stainless steel. To manage corrosion, chemical inhibitors are often used for prevention and control. Ionic liquids due to their hydrophobic and corrosion-resistant property are being explored as alternative protective coatings and anti-corrosion materials. In this particular study, ionic liquids containing functionalized imidazolium cations and tris(pentafluoroethyl)trifluorophosphate (FAP) anions were investigated for their ability to inhibit corrosion on stainless steel surfaces in acidic environment. Using surface characterization techniques, specifically scanning electron microscopy and energy-dispersive X-ray (EDX), the morphology and the elemental composition of the steel surfaces before and after corrosion were determined. Contact angle measurements were also performed to determine how these ionic liquids were able to wet the stainless steel surface. In addition, potentiodynamic studies were carried out to ensure that corrosion inhibition has occurred. Results show that these ionic liquids were able to inhibit corrosion on the stainless steel surfaces. This indicates promise in the use of these FAP-based ionic liquids for corrosion management in stainless steel.

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