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1.
bioRxiv ; 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38659950

RESUMO

Voltage imaging enables high-throughput investigation of neuronal activity, yet its utility is often constrained by a low signal-to-noise ratio (SNR). Conventional denoising algorithms, such as those based on matrix factorization, impose limiting assumptions about the noise process and the spatiotemporal structure of the signal. While deep learning based denoising techniques offer greater adaptability, existing approaches fail to fully exploit the fast temporal dynamics and unique short- and long-range dependencies within voltage imaging datasets. Here, we introduce CellMincer, a novel self-supervised deep learning method designed specifically for denoising voltage imaging datasets. CellMincer operates on the principle of masking and predicting sparse sets of pixels across short temporal windows and conditions the denoiser on precomputed spatiotemporal auto-correlations to effectively model long-range dependencies without the need for large temporal denoising contexts. We develop and utilize a physics-based simulation framework to generate realistic datasets for rigorous hyperparameter optimization and ablation studies, highlighting the key role of conditioning the denoiser on precomputed spatiotemporal auto-correlations to achieve 3-fold further reduction in noise. Comprehensive benchmarking on both simulated and real voltage imaging datasets, including those with paired patch-clamp electrophysiology (EP) as ground truth, demonstrates CellMincer's state-of-the-art performance. It achieves substantial noise reduction across the entire frequency spectrum, enhanced detection of subthreshold events, and superior cross-correlation with ground-truth EP recordings. Finally, we demonstrate how CellMincer's addition to a typical voltage imaging data analysis workflow improves neuronal segmentation, peak detection, and ultimately leads to significantly enhanced separation of functional phenotypes.

2.
Obes Surg ; 34(4): 1217-1223, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38409623

RESUMO

PURPOSE: The utility of routine post-discharge VTE prophylaxis after bariatric surgery remains a matter of debate. While inpatient chemical prophylaxis decreases the risk of fatal pulmonary embolism, most thromboembolic events occur after discharge and carry high morbidity and mortality. To address this risk, apixaban was introduced as extended prophylaxis for 30 days after surgery. MATERIALS AND METHODS: The study ranges between 1/2014 and 7/2022. Apixaban was incorporated as routine extended prophylaxis protocol in 05/2017 and is dosed at 2.5 mg BID for 30 days. There were two study groups: those who received apixaban on discharge (n = 1443; 60%) and those who did not (n = 953; 40%). Patients with concern for postoperative bleeding (hypotension, unexplained tachycardia with hematocrit drop > 6%, hematocrit drop > 9%), or on preoperative anticoagulant/antiplatelet therapy (except aspirin), were not discharged on apixaban. Post-discharge VTE, readmission, transfusion, and reoperation rates were compared between groups. RESULTS: There were 2396 consecutive primary bariatric operations: sleeve gastrectomy (1949; 81%), Roux-en-Y gastric bypass (419; 18%), and duodenal switch (28; 1%). There were no post-discharge VTEs in patients treated with apixaban vs. five (0.5%) VTEs in patients who did not receive treatment; p = 0.02. There was a higher incidence in post-discharge bleeding events in the apixaban group (0.5 vs 0.3%; p = 0.75), mostly requiring readmission for monitoring without intervention or transfusion. In the apixaban group, one patient underwent EGD for bleeding while another required blood transfusion; there were no reoperations for bleeding. CONCLUSION: There were no post-discharge VTEs in patients who received apixaban. Treatment was associated with a higher risk of self-resolving bleeding events. This study adds to the increasing body of evidence supporting the benefit of routine, extended oral chemoprophylaxis after bariatric surgery.


Assuntos
Cirurgia Bariátrica , Obesidade Mórbida , Tromboembolia Venosa , Humanos , Tromboembolia Venosa/etiologia , Assistência ao Convalescente , Alta do Paciente , Complicações Pós-Operatórias/epidemiologia , Obesidade Mórbida/cirurgia , Anticoagulantes , Cirurgia Bariátrica/efeitos adversos , Hemorragia Pós-Operatória/etiologia
3.
Cell Rep ; 42(1): 111988, 2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36640364

RESUMO

The maturation of neurons and the development of synapses, although emblematic of neurons, also relies on interactions with astrocytes and other glia. Here, to study the role of glia-neuron interactions, we analyze the transcriptomes of human pluripotent stem cell (hPSC)-derived neurons, from 80 human donors, that were cultured with or without contact with glial cells. We find that the presence of astrocytes enhances synaptic gene-expression programs in neurons when in physical contact with astrocytes. These changes in neurons correlate with increased expression, in the cocultured glia, of genes that encode synaptic cell adhesion molecules. Both the neuronal and astrocyte gene-expression programs are enriched for genes associated with schizophrenia risk. Our results suggest that astrocyte-expressed genes with synaptic functions are associated with stronger expression of synaptic genetic programs in neurons, and they suggest a potential role for astrocyte-neuron interactions in schizophrenia.


Assuntos
Astrócitos , Esquizofrenia , Humanos , Astrócitos/metabolismo , Adesão Celular/genética , Esquizofrenia/genética , Esquizofrenia/metabolismo , Neurônios/metabolismo , Neuroglia , Sinapses/fisiologia
4.
Biomicrofluidics ; 16(3): 034104, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35600502

RESUMO

Microfluidics can bring unique functionalities to cell processing, but the small channel dimensions often limit the throughput for cell processing that prevents scaling necessary for key applications. While processing throughput can be improved by increasing cell concentration or flow rate, an excessive number or velocity of cells can result in device failure. Designing parallel channels can linearly increase the throughput by channel number, but for microfluidic devices with multiple inlets and outlets, the design of the channel architecture with parallel channels can result in intractable numbers of inlets and outlets. We demonstrate an approach to use multiple parallel channels for complex microfluidic designs that uses a second manifold layer to connect three inlets and five outlets per channel in a manner that balances flow properties through each channel. The flow balancing in the individual microfluidic channels was accomplished through a combination of analytical and finite element analysis modeling. Volumetric flow and cell flow velocity were measured in each multiplexed channel to validate these models. We demonstrate eight-channel operation of a label-free mechanical separation device that retains the accuracy of a single channel separation. Using the parallelized device and a model biomechanical cell system for sorting of cells based on their viability, we processed over 16 × 106 cells total over three replicates at a rate of 5.3 × 106 cells per hour. Thus, parallelization of complex microfluidics with a flow-balanced manifold system can enable higher throughput processing with the same number of inlet and outlet channels to control.

5.
J Explor Res Pharmacol ; 5(4): 73-80, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34589670

RESUMO

BACKGROUND AND OBJECTIVES: VS-105, a novel vitamin D receptor agonist with significantly less hypercalcemic side effects than calcitriol, is a useful tool to investigate whether or not a vitamin D receptor agonist at non-hypercalcemic doses could improve bone mineral density (BMD). METHODS: VS-105 and calcitriol were evaluated in an ovariectomized (OVX) osteoporosis rat model and in calvariae bone organ culture. RESULTS: Treatment of OVX rats by VS-105 (0.1, 0.2 or 0.5 µg/kg, intraperitoneal, 3×/week, for 90 days) significantly improved BMD in the L3 lumbar vertebra in a dose-dependent manner (sham vs. OVX/vehicle: 324 ± 14 vs. 279 ± 10 mg/cm2; VS-105 at 0.1, 0.2 and 0.5 µg/kg: 306 ± 9, 329 ± 12, and 327 ± 10 mg/cm2, respectively) without affecting serum calcium (Ca). Calcitriol at 0.1 µg/kg significantly increased BMD but it also increased serum Ca. VS-105 and calcitriol at the test doses significantly suppressed serum parathyroid hormone and promoted tibia bone growth. With respect to biomarkers of bone remodeling, calcitriol and VS-105 both significantly elevated serum osteocalcin. In the calvariae bone organ culture, net Ca release was significantly less in VS-105-treated groups (vs. calcitriol). CONCLUSIONS: VS-105 is efficacious in improving BMD in a dose range that does not affect serum Ca in OVX rats; the improvement in BMD by VS-105 is attributable to increased osteoblastic activity and reduced osteoclastic bone resorption.

6.
Proc Natl Acad Sci U S A ; 116(26): 12710-12719, 2019 06 25.
Artigo em Inglês | MEDLINE | ID: mdl-31182572

RESUMO

Despite significant research efforts, clinical practice for arterial bypass surgery has been stagnant, and engineered grafts continue to face postimplantation challenges. Here, we describe the development and application of a durable small-diameter vascular graft with tailored regenerative capacity. We fabricated small-diameter vascular grafts by electrospinning fibrin tubes and poly(ε-caprolactone) fibrous sheaths, which improved suture retention strength and enabled long-term survival. Using surface topography in a hollow fibrin microfiber tube, we enable immediate, controlled perfusion and formation of a confluent endothelium within 3-4 days in vitro with human endothelial colony-forming cells, but a stable endothelium is noticeable at 4 weeks in vivo. Implantation of acellular or endothelialized fibrin grafts with an external ultrathin poly(ε-caprolactone) sheath as an interposition graft in the abdominal aorta of a severe combined immunodeficient Beige mouse model supports normal blood flow and vessel patency for 24 weeks. Mechanical properties of the implanted grafts closely approximate the native abdominal aorta properties after just 1 week in vivo. Fibrin mediated cellular remodeling, stable tunica intima and media formation, and abundant matrix deposition with organized collagen layers and wavy elastin lamellae. Endothelialized grafts evidenced controlled healthy remodeling with delayed and reduced macrophage infiltration alongside neo vasa vasorum-like structure formation, reduced calcification, and accelerated tunica media formation. Our studies establish a small-diameter graft that is fabricated in less than 1 week, mediates neotissue formation and incorporation into the native tissue, and matches the native vessel size and mechanical properties, overcoming main challenges in arterial bypass surgery.


Assuntos
Materiais Biocompatíveis/química , Endotélio Vascular/fisiologia , Regeneração , Enxerto Vascular/métodos , Animais , Artérias/fisiologia , Artérias/cirurgia , Feminino , Fibrina/química , Camundongos , Poliésteres/química , Fluxo Sanguíneo Regional , Engenharia Tecidual/métodos
7.
J Am Acad Child Adolesc Psychiatry ; 57(4): 288-289, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29588055

RESUMO

Avoidant and restrictive food intake disorder (ARFID) is a newly classified disorder in the DSM-5 that describes a pattern of restrictive eating across the lifespan that results in significant weight loss, nutritional deficiency, dependence on enteral feeding or nutritional supplements, or marked interference in psychosocial functioning.1 Currently, there are no evidence-based treatment approaches or medications for this disorder.2 We have administered a range of psychoactive medications to those with ARFID in our treatment program in an attempt to find an effective medication. One medication of interest has been mirtazapine because it promotes appetite and weight gain, decreases nausea and vomiting, and improves gastric emptying. Although mirtazapine is an off-label approach in a pediatric population and carries a black box warning for an increased risk of suicide, it is an effective treatment for depression and anxiety symptoms in adults and is generally well tolerated.3,4 There are no studies to date reporting on the use of mirtazapine in patients with ARFID.


Assuntos
Antidepressivos/uso terapêutico , Transtornos da Alimentação e da Ingestão de Alimentos/tratamento farmacológico , Mirtazapina/uso terapêutico , Uso Off-Label , Aumento de Peso/fisiologia , Adolescente , Adulto , Transtornos de Ansiedade/psicologia , Criança , Feminino , Humanos , Masculino , Transtornos do Humor/psicologia , Estudos Retrospectivos , Adulto Jovem
9.
Alcohol Clin Exp Res ; 40(3): 518-28, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26858005

RESUMO

BACKGROUND: Obesity and the metabolic syndrome occur in approximately one-third of patients with alcoholic liver disease (ALD). The increased consumption of fructose parallels the increased prevalence of obesity and the metabolic syndrome in the United States and worldwide. In this study, we investigated whether dietary high fructose potentiates chronic alcohol-induced liver injury, and explored potential mechanism(s). METHODS: Six-week-old male C57BL/6J mice were assigned to 4 groups: control, high fructose, chronic ethanol (EtOH), and high fructose plus chronic alcohol. The mice were fed either control diet or high-fructose diet (60%, w/w) for 18 weeks. Chronic alcohol-fed mice were given 20% (v/v) ethanol (Meadows-Cook model) ad libitum as the only available liquid from the 9th week through the 18th week. Liver injury, steatosis, hepatic inflammatory gene expression, and copper status were assessed. RESULTS: High-fructose diet and chronic alcohol consumption alone each induce hepatic fat accumulation and impair copper status. However, the combination of dietary high fructose plus chronic alcohol synergistically induced liver injury as evidenced by robustly increased plasma alanine aminotransferase and aspartate aminotransferase, but the combination did not exacerbate hepatic fat accumulation nor worsen copper status. Moreover, FE-fed mice were characterized by prominent microvesicular steatosis. High-fructose diet and chronic alcohol ingestion together led to a significant up-regulation of Kupffer cell (KC) M1 phenotype gene expression (e.g., tumor necrosis factor-α and monocyte chemoattractant protein-1), as well as Toll-like receptor 4 (TLR4) signaling gene expression, which is also associated with the up-regulation of KCs and activation marker gene expression, including Emr1, CD68, and CD163. CONCLUSIONS: Our data suggest that dietary high fructose may potentiate chronic alcohol consumption-induced liver injury. The underlying mechanism might be due to the synergistic effect of dietary high fructose and alcohol on the activation of the TLR4 signaling pathway, which in turn leads to KC activation and phenotype switch toward M1 polarization. This study suggests that alcohol-fructose combination contributes to ALD progression.


Assuntos
Consumo de Bebidas Alcoólicas/metabolismo , Alcoolismo/metabolismo , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/metabolismo , Frutose/toxicidade , Hepatopatias Alcoólicas/metabolismo , Consumo de Bebidas Alcoólicas/efeitos adversos , Animais , Frutose/administração & dosagem , Masculino , Síndrome Metabólica/metabolismo , Camundongos , Camundongos Endogâmicos C57BL
10.
J Cosmet Sci ; 67(2): 93-100, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-29394012

RESUMO

Consumer perception of longitudinal striations of the nail is one of the drivers of nail cosmetic purchase and use. The following work investigates the use of objective instrumental methods for the characterization of longitudinal striations. Striations are quantified by Ra (the average maximum height of the profile), Rq (the root mean square average of the roughness profile), and Rz (the mean roughness depth), industrial roughness parameters, which are calculated using optical profilometry of the three-dimensional surface structure of the nail. A visual assessment is conducted by cosmetologists in vivo and on images captured in several lighting conditions. With this evaluation, the cosmetologists provide ratings of surface ridges on a 0­5 scale to complement and validate the instrumental method. Both the optical profilometry and the cosmetologist-graded methods are used to evaluate 33 nails of visually-varying levels of ridges from female volunteers. The evaluations from these methods yield well-correlated and repeatable results, and these preliminary findings suggest that this new instrumental method can be used to objectively measure longitudinal striations of the nail.


Assuntos
Unhas/diagnóstico por imagem , Fotometria/métodos , Adolescente , Adulto , Idoso , Cosméticos/administração & dosagem , Feminino , Humanos , Pessoa de Meia-Idade , Unhas/anatomia & histologia , Fotometria/instrumentação , Reprodutibilidade dos Testes , Propriedades de Superfície
11.
Dermatoendocrinol ; 5(2): 319-24, 2013 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-24194973

RESUMO

This study was conducted to compare lipid components of sebum from persons from three ethnic backgrounds-Caucasian, African American and Northern Asian. Men and women with no acne in two age groups (18‒25 y and 35‒45 y) were recruited. Skin surface hydration (SkiCon 200EX and NovaMeter), barrier function (Delfin VapoMeter), high-resolution clinical imaging, self-assessments and two pairs of sebutapes on the forehead that extracted the lipids on the surface of their skin were used. Significant differences (p < 0.05) in skin hydration between African Americans and Caucasians in both age groups were noted, with the order from highest to lowest absolute values: African American > Northern Asian > Caucasian. Transepidermal water loss (TEWL) measurements demonstrated that African Americans and Caucasians were significantly different (p < 0.05), with the trend being the inverse of the hydration trend-Caucasian > Northern Asian > African American, which would indicate better barrier function for African Americans with a lower TEWL. African American women had more total lipid production than Northern Asian or Caucasian women. When analyzing the three lipid classes (free fatty acids, triglycerides and wax esters), the trend became significant (p < 0.05) in the wax ester fraction when directly comparing African Americans with Caucasians. Additionally, six lipids were identified in the wax ester fractions that were significantly different in quantity (p < 0.05) between African Americans and Caucasians. These results identified significant differences in sebaceous lipid profiles across ethnic groups and determined that the differences correlated with skin barrier function.

12.
Front Immunol ; 4: 132, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23761791

RESUMO

BACKGROUND: There is no cure for autoimmune chronic inflammatory bowel disease (IBD). IBD patients commonly use complementary and alternative medications of which the safety, efficacy, and interaction with standard-of-care therapies are not fully known. Thus the consequences can become life-threatening. Sulfasalazine commonly used in IBD, potentially has severe adverse effects, including infertility, pulmonary fibrosis, lack of response, and ultimately patients may require intestinal resection. We hypothesized that green tea polyphenols (GrTP, EGCG) and sulfasalazine have similar anti-inflammatory properties. METHODS: BALB/c mice received Dextran sodium sulfate (DSS) to induce colitis (ulcerative colitis model). Exposure of IL-10 deficient mice (BALB/c-background) to normal microbiota provoked enterocolitis (mimics Crohn's disease). Animals were treated with agents incorporated into daily diets. Control animals received sham treatment. RESULTS: DSS-treated animals developed severe bloody diarrhea and colitis (score 0-4, 3.2 ± 0.27). IL-10 deficient mice developed severe enterocolitis as manifested by diarrhea, rectal prolapse, and colonic lesions. Animals tolerated regimens (GrTP, EGCG, sulfasalazine) with no major side effects, and further developed less severe colitis. IL-10 deficient animals became moribund on high dose, while tolerated low and Mid doses with significant improved symptoms of enterocolitis. GrTP, EGCG, and sulfasalazine significantly ameliorated colonic damage and histological scores in treated animals in a similar manner (GrTP vs. DSS p < 0.05; EGCG, sulfasalazine vs. DSS p < 0.01). The inflammatory markers TNFα (3-fold), IL-6 (14-fold), and serum amyloid A (40-fold) increased in colitic animals and significantly decreased with treatment regiments. In contrast, circulatory leptin levels decreased in colitic animals (twofold). EGCG additionally reduced leptin levels (p < 0.01) while GrTP and sulfasalazine had no effect on leptin levels (p < 0.05). Hepatic and colonic antioxidants were significantly depleted in colitic animals and treatment regiments significantly restored antioxidants levels. CONCLUSION: GrTP and EGCG improved antioxidants levels and attenuated severity of colitis analogous to sulfasalazine. Future studies will reveal whether polyphenols can become an alternative/additive therapy for IBD therapy in humans.

13.
Obesity (Silver Spring) ; 21(8): 1669-75, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23512597

RESUMO

OBJECTIVE: Dietary fructose and copper interaction may play an important role in the pathogenesis of nonalcoholic fatty liver disease. In this study, whether or not modest fructose consumption (3% fructose, w/v) (which is more closely related to the American lifestyle with regard to sugar beverage consumption) affects copper status, and causes liver injury and fat accumulation in marginal copper deficient rats was investigated. DESIGN AND METHODS: Male weanling Sprague-Dawley rats were fed either an adequate copper (6 ppm) or a marginally copper deficient (1.6 ppm) diet for 4 weeks. Deionized water or deionized water containing 3% fructose (w/v) was given ad lib. RESULTS: Modest fructose consumption further impaired copper status in the marginal copper deficient rats and increased hepatic iron accumulation. Liver injury and fat accumulation were significantly induced in the marginal copper deficient rats exposed to fructose. CONCLUSIONS: Our data suggest that modest fructose consumption can impair copper status and lead to hepatic iron overload, which in turn, may lead to liver injury and fatty liver in marginal copper deficient rats. This study provides important information on dietary fructose and copper interaction, suggesting that dietary fructose-induced low copper availability might be an important mechanism underlying fructose-induced fatty liver.


Assuntos
Bebidas , Cobre/deficiência , Fígado Gorduroso/patologia , Frutose/efeitos adversos , Fígado/patologia , Animais , Disponibilidade Biológica , Quimiocina CCL2/metabolismo , Cobre/administração & dosagem , Cobre/sangue , Cobre/farmacocinética , Fígado Gorduroso/induzido quimicamente , Frutose/administração & dosagem , Glutationa/metabolismo , Dissulfeto de Glutationa/metabolismo , Imuno-Histoquímica , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/patologia , Masculino , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Superóxido Dismutase/metabolismo , Superóxido Dismutase-1 , Triglicerídeos/metabolismo
14.
J Hepatol ; 56(2): 433-40, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21781943

RESUMO

BACKGROUND & AIMS: Dietary copper deficiency is associated with a variety of manifestations of the metabolic syndrome, including hyperlipidemia and fatty liver. Fructose feeding has been reported to exacerbate complications of copper deficiency. In this study, we investigated whether copper deficiency plays a role in fructose-induced fatty liver and explored the potential underlying mechanism(s). METHODS: Male weanling Sprague-Dawley rats were fed either an adequate copper or a marginally copper deficient diet for 4 weeks. Deionized water or deionized water containing 30% fructose (w/v) was also given ad lib. Copper and iron status, hepatic injury and steatosis, and duodenum copper transporter-1 (Ctr-1) were assessed. RESULTS: Fructose feeding further impaired copper status and led to iron overload. Liver injury and fat accumulation were significantly induced in marginal copper deficient rats exposed to fructose as evidenced by robustly increased plasma aspartate aminotransferase (AST) and hepatic triglyceride. Hepatic carnitine palmitoyl-CoA transferase I (CPT I) expression was significantly inhibited, whereas hepatic fatty acid synthase (FAS) was markedly up-regulated in marginal copper deficient rats fed with fructose. Hepatic antioxidant defense system was suppressed and lipid peroxidation was increased by marginal copper deficiency and fructose feeding. Moreover, duodenum Ctr-1 expression was significantly increased by marginal copper deficiency, whereas this increase was abrogated by fructose feeding. CONCLUSIONS: Our data suggest that high fructose-induced nonalcoholic fatty liver disease (NAFLD) may be due, in part, to inadequate dietary copper. Impaired duodenum Ctr-1 expression seen in fructose feeding may lead to decreased copper absorption, and subsequent copper deficiency.


Assuntos
Cobre/deficiência , Fígado Gorduroso/etiologia , Fígado Gorduroso/metabolismo , Frutose/administração & dosagem , Obesidade/complicações , Obesidade/metabolismo , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Proteínas de Transporte de Cátions/metabolismo , Cobre/administração & dosagem , Transportador de Cobre 1 , Modelos Animais de Doenças , Ácidos Graxos/metabolismo , Frutose/efeitos adversos , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/metabolismo , Lipogênese , Fígado/lesões , Fígado/metabolismo , Masculino , Hepatopatia Gordurosa não Alcoólica , Estresse Oxidativo , Ratos , Ratos Sprague-Dawley , Edulcorantes/administração & dosagem , Edulcorantes/efeitos adversos
15.
J Biochem Mol Toxicol ; 26(2): 71-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22162043

RESUMO

Acetaminophen (APAP) is hepatotoxic and can cause toxicity in Jurkat T cells. p-Aminophenol (PAP), an industrial chemical and APAP metabolite, is nephrotoxic and hepatotoxic. Its potential toxicity in Jurkat T cells was investigated. PAP (10-250 µM) caused toxicity (decreased survival and increased LDH activity in incubation medium) and GSH depletion. At a concentration of 100 µM but not 250 µM, PAP increased DNA fragmentation. It decreased p-Akt levels (Elisa) and at higher concentrations decreased p-Akt expression (Western blotting). It had no effect on FasL expression. The cysteine precursor 2(RS)-n-propylthiazolidine-4(R)-carboxylic acid (250 µM) attenuated the PAP (100 µM)-induced decrease in viability and prevented GSH depletion and increased DNA fragmentation. It attenuated the PAP-induced decrease in p-Akt levels and protected against the decrease in p-Akt expression. The results demonstrate PAP-induced toxicity and suggest that it is due at least in part to apoptosis and involves GSH depletion and p-Akt inactivation.


Assuntos
Aminofenóis/toxicidade , Citoproteção , Oxidantes/toxicidade , Linfócitos T/efeitos dos fármacos , Tiazóis/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Ativação Enzimática , Proteína Ligante Fas/genética , Proteína Ligante Fas/metabolismo , Expressão Gênica/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Células Jurkat , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linfócitos T/enzimologia , Linfócitos T/metabolismo
16.
J Pharmacol Exp Ther ; 339(1): 298-306, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21784888

RESUMO

Copper levels are elevated in a variety of liver fibrosis conditions. Lowering copper to a certain level protects against fibrosis. However, whether severe copper deficiency is protective against liver fibrosis is not known. The purpose of the present study is to evaluate this question by inducing severe copper deficiency using the copper chelator, tetrathiomolybdate (TM), in a bile duct ligation (BDL) rat model. Male Sprague-Dawley rats were divided into four groups: sham, sham plus TM, BDL, and BDL plus TM. TM was given in a daily dose of 10 mg/kg by body weight by means of intragastric gavage, beginning 5 days after BDL. All animals were killed 2 weeks after surgery. Severe copper deficiency was induced by TM overdose in either sham or BDL rats, as shown by decreased plasma ceruloplasmin activity. Liver injury and fibrosis were exacerbated in BDL rats with TM treatment, as illustrated by robustly increased plasma aspartate aminotransferase and hepatic collagen accumulation. Iron stores, as measured by plasma ferritin, were significantly increased in copper-deficient BDL rats. Moreover, hepatic heme oxygenase-1 expression was markedly down-regulated by copper deficiency in BDL rats. In addition, hepatic gene expression involving mitochondrial biogenesis and ß-oxidation was significantly up-regulated in BDL rats, and this increase was abolished by copper deficiency. In summary, severe copper deficiency exacerbates BDL-induced liver injury and liver fibrosis, probably caused by increased iron overload and decreased antioxidant defenses and mitochondrial dysfunction.


Assuntos
Ductos Biliares/fisiologia , Cobre/deficiência , Cirrose Hepática/patologia , Lesão Pulmonar/patologia , Inibidores da Angiogênese/toxicidade , Animais , Western Blotting , Peso Corporal/fisiologia , Colestase/patologia , Cobre/metabolismo , Glutationa/metabolismo , Heme Oxigenase-1/metabolismo , Imuno-Histoquímica , Ferro/metabolismo , Ligadura , Fígado/efeitos dos fármacos , Fígado/enzimologia , Masculino , Molibdênio/toxicidade , Estado Nutricional , Tamanho do Órgão/fisiologia , RNA/biossíntese , RNA/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase Via Transcriptase Reversa , S-Adenosilmetionina/metabolismo
18.
Biochim Biophys Acta ; 1812(5): 613-8, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21296661

RESUMO

Methionine metabolism is disrupted in patients with alcoholic liver disease, resulting in altered hepatic concentrations of S-adenosylmethionine (SAM), S-adenosylhomocysteine (SAH), and other metabolites. The present study tested the hypothesis that reductive stress mediates the effects of ethanol on liver methionine metabolism. Isolated rat livers were perfused with ethanol or propanol to induce a reductive stress by increasing the NADH/NAD(+) ratio, and the concentrations of SAM and SAH in the liver tissue were determined by high-performance liquid chromatography. The increase in the NADH/NAD(+) ratio induced by ethanol or propanol was associated with a marked decrease in SAM and an increase in SAH liver content. 4-Methylpyrazole, an inhibitor the NAD(+)-dependent enzyme alcohol dehydrogenase, blocked the increase in the NADH/NAD(+) ratio and prevented the alterations in SAM and SAH. Similarly, co-infusion of pyruvate, which is metabolized by the NADH-dependent enzyme lactate dehydrogenase, restored the NADH/NAD(+) ratio and normalized SAM and SAH levels. The data establish an initial link between the effects of ethanol on the NADH/NAD(+) redox couple and the effects of ethanol on methionine metabolism in the liver.


Assuntos
Etanol/farmacologia , Fígado/efeitos dos fármacos , NAD/metabolismo , S-Adenosil-Homocisteína/metabolismo , S-Adenosilmetionina/metabolismo , 1-Propanol/farmacologia , Animais , Anti-Infecciosos Locais/farmacologia , Fígado/metabolismo , Masculino , Oxirredução , Perfusão , Ratos , Ratos Sprague-Dawley
19.
Photodermatol Photoimmunol Photomed ; 27(1): 30-4, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21198880

RESUMO

BACKGROUND: High sun protection factor (SPF) sunscreens have multiple benefits but there has not been validation of the test method for determining SPF values higher than 50. This study addresses specifically the accuracy and reproducibility of the high SPF test. METHODS: Two high SPF formulations with a standard reference (SPF 15) were tested at four independent test facilities according to the 2007 FDA proposed amendments to the sunscreen monograph. Statistical analysis was performed to compare the SPF results within each lab as well as the SPF results between different labs. RESULTS: The test formulations have overall mean values of 90.5 and 70.7. There was no statistically significant difference between the labs for either formulation and all four labs were able to statistically differentiate these two levels of SPF values. The coefficients of variance (CV) for the high SPF formulations were comparable to those of the corresponding SPF 15 reference within each lab. CONCLUSIONS: The data show that SPF values above 50 and up to at least 90 can be measured by multiple laboratories with accuracy and reproducibility.


Assuntos
Laboratórios/normas , Proteção Radiológica/normas , Protetores Solares/química , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Queimadura Solar/prevenção & controle , Adulto Jovem
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