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1.
J Racial Ethn Health Disparities ; 9(4): 1210-1224, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-34128216

RESUMO

Few studies have assessed how the intersection of social determinants of health and environmental hazards contributes to racial disparities in COVID-19. The aim of our study was to compare COVID-19 disparities in testing and positivity to cumulative environmental health impacts, and to assess how unique social and environmental determinants of health relate to COVID-19 positivity in Seattle, King County, WA, at the census tract level. Publicly available data (n = 397 census tracts) were obtained from Public Health-Seattle & King County, 2018 ACS 5-year estimates, and the Washington Tracking Network. COVID-19 testing and positive case rates as of July 12, 2020, were mapped and compared to Washington State Environmental Health Disparities (EHD) Map cumulative impact rankings. We calculated odds ratios from a series of univariable and multivariable logistic regression analyses using cumulative impact rankings, and community-level socioeconomic, health, and environmental factors as predictors and having ≥ 10% or < 10% census tract positivity as the binary outcome variable. We found a remarkable overlap between Washington EHD cumulative impact rankings and COVID-19 positivity in King County. Census tracts with ≥ 10 % COVID-19 positivity had significantly lower COVID-19 testing rates and higher proportions of people of color and faced a combination of low socioeconomic status-related outcomes, poor community health outcomes, and significantly higher concentrations of fine particulate matter (PM2.5). King County communities experiencing high rates of COVID-19 face a disproportionate cumulative burden of environmental and social inequities. Cumulative environmental health impacts should therefore systematically be considered when assessing for risk of exposure to and health complications resulting from COVID-19.


Assuntos
COVID-19 , Teste para COVID-19 , Humanos , Renda , Pobreza , Washington/epidemiologia
2.
Artigo em Inglês | MEDLINE | ID: mdl-33353095

RESUMO

Individual-level Coronavirus Disease 2019 (COVID-19) case data suggest that certain populations may be more impacted by the pandemic. However, few studies have considered the communities from which positive cases are prevalent, and the variations in testing rates between communities. In this study, we assessed community factors that were associated with COVID-19 testing and test positivity at the census tract level for the Seattle, King County, Washington region at the summer peak of infection in July 2020. Multivariate Poisson regression was used to estimate confirmed case counts, adjusted for testing numbers, which were associated with socioeconomic status (SES) indicators such as poverty, educational attainment, transportation cost, as well as with communities with high proportions of people of color. Multivariate models were also used to examine factors associated with testing rates, and found disparities in testing for communities of color and communities with transportation cost barriers. These results demonstrate the ability to identify tract-level indicators of COVID-19 risk and specific communities that are most vulnerable to COVID-19 infection, as well as highlight the ongoing need to ensure access to disease control resources, including information and education, testing, and future vaccination programs in low-SES and highly diverse communities.


Assuntos
Teste para COVID-19 , COVID-19/diagnóstico , COVID-19/epidemiologia , Fatores Socioeconômicos , Etnicidade , Disparidades em Assistência à Saúde , Humanos , Pandemias , Pobreza , Meios de Transporte , Washington/epidemiologia
4.
Med Teach ; 42(3): 291-298, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31633998

RESUMO

Purpose: Current medical education models maintain that competencies such as professionalism and communication can be taught; however, some argue that certain attributes that make up these competencies, such as empathy, are fixed. Teachers' implicit theories, or mindsets (beliefs about the fixed versus learnable nature of human attributes) have been shown to impact their teaching and assessment practices; but little work has explored mindsets in medical education. We examined clinical supervisors' mindsets of two cognitive attributes (intelligence and clinical reasoning) and two affective attributes (moral character and empathy).Methods: Clinical supervisors (n = 40) from three specialities completed a survey designed to measure mindsets using two existing instruments for intelligence and moral character and 18 new items for clinical reasoning and empathy. Participants completed the survey twice for test-retest reliability (n = 25).Results: New items had satisfactory psychometric properties. Clinical supervisors' mindsets were mixed. Only 8% of participants saw clinical reasoning as fixed while more saw empathy (45%), intelligence (53%), and moral character (53%) as fixed - running counter to current educational models that characterize these attributes as learnable.Conclusion: This study provides evidence supporting the use of these new tools to measure mindsets that may help to better understand the impact of mindsets on medical education.


Assuntos
Educação Médica , Inteligência , Empatia , Humanos , Reprodutibilidade dos Testes , Inquéritos e Questionários
5.
Acta Neuropathol ; 138(6): 1013-1031, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31463572

RESUMO

MSTO1 encodes a cytosolic mitochondrial fusion protein, misato homolog 1 or MSTO1. While the full genotype-phenotype spectrum remains to be explored, pathogenic variants in MSTO1 have recently been reported in a small number of patients presenting with a phenotype of cerebellar ataxia, congenital muscle involvement with histologic findings ranging from myopathic to dystrophic and pigmentary retinopathy. The proposed underlying pathogenic mechanism of MSTO1-related disease is suggestive of impaired mitochondrial fusion secondary to a loss of function of MSTO1. Disorders of mitochondrial fusion and fission have been shown to also lead to mitochondrial DNA (mtDNA) depletion, linking them to the mtDNA depletion syndromes, a clinically and genetically diverse class of mitochondrial diseases characterized by a reduction of cellular mtDNA content. However, the consequences of pathogenic variants in MSTO1 on mtDNA maintenance remain poorly understood. We present extensive phenotypic and genetic data from 12 independent families, including 15 new patients harbouring a broad array of bi-allelic MSTO1 pathogenic variants, and we provide functional characterization from seven MSTO1-related disease patient fibroblasts. Bi-allelic loss-of-function variants in MSTO1 manifest clinically with a remarkably consistent phenotype of childhood-onset muscular dystrophy, corticospinal tract dysfunction and early-onset non-progressive cerebellar atrophy. MSTO1 protein was not detectable in the cultured fibroblasts of all seven patients evaluated, suggesting that pathogenic variants result in a loss of protein expression and/or affect protein stability. Consistent with impaired mitochondrial fusion, mitochondrial networks in fibroblasts were found to be fragmented. Furthermore, all fibroblasts were found to have depletion of mtDNA ranging from 30 to 70% along with alterations to mtDNA nucleoids. Our data corroborate the role of MSTO1 as a mitochondrial fusion protein and highlight a previously unrecognized link to mtDNA regulation. As impaired mitochondrial fusion is a recognized cause of mtDNA depletion syndromes, this novel link to mtDNA depletion in patient fibroblasts suggests that MSTO1-deficiency should also be considered a mtDNA depletion syndrome. Thus, we provide mechanistic insight into the disease pathogenesis associated with MSTO1 mutations and further define the clinical spectrum and the natural history of MSTO1-related disease.


Assuntos
Proteínas de Ciclo Celular/genética , Doenças Cerebelares/genética , Proteínas do Citoesqueleto/genética , DNA Mitocondrial , Doenças Mitocondriais/genética , Distrofias Musculares/genética , Mutação , Adolescente , Adulto , Atrofia , Células Cultivadas , Doenças Cerebelares/diagnóstico por imagem , Doenças Cerebelares/patologia , Doenças Cerebelares/fisiopatologia , Criança , Variações do Número de Cópias de DNA , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Mitocondriais/diagnóstico por imagem , Doenças Mitocondriais/patologia , Doenças Mitocondriais/fisiopatologia , Músculos/patologia , Distrofias Musculares/diagnóstico por imagem , Distrofias Musculares/patologia , Distrofias Musculares/fisiopatologia , Fenótipo , Adulto Jovem
9.
Chem Biol Interact ; 258: 21-9, 2016 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-27543423

RESUMO

This study determined the anti-neoplastic activity and nephrotoxicity of epigenetic inhibitors in vitro. The therapeutic efficacy of epigenetic inhibitors was determined in human prostate cancer cells (PC-3 and LNCaP) using the DNA methyltransferase inhibitor 5-aza-2'-deoxycytidine (5-Aza) and the histone deacetylase inhibitor trichostatin A (TSA). Cells were also treated with carbamazepine (CBZ), an anti-convulsant with histone deacetylase inhibitor-like properties. 5-Aza, TSA or CBZ alone did not decrease MTT staining in PC-3 or LNCaP cells after 48 h. In contrast, docetaxel, a frontline chemotherapeutic induced concentration-dependent decreases in MTT staining. Pretreatment with 5-Aza or TSA increased docetaxel-induced cytotoxicity in LNCaP cells, but not PC-3 cells. TSA pretreatment also increased cisplatin-induced toxicity in LNCaP cells. Carfilzomib (CFZ), a protease inhibitor approved for the treatment of multiple myeloma had minimal effect on LNCaP cell viability, but reduced MTT staining 50% in PC-3 cells compared to control, and pretreatment with 5-Aza further enhanced toxicity. Treatment of normal rat kidney (NRK) and human embryonic kidney 293 (HEK293) cells with the same concentrations of epigenetic inhibitors used in prostate cancer cells significantly decreased MTT staining in all cell lines after 48 h. Interestingly, we found that the toxicity of epigenetic inhibitors to kidney cells was dependent on both the compound and the stage of cell growth. The effect of 5-Aza and TSA on DNA methyltransferase and histone deacetylase activity, respectively, was confirmed by assessing the methylation and acetylation of the CDK inhibitor p21. Collectively, these data show that combinatorial treatment with epigenetic inhibitors alters the efficacy of chemotherapeutics in cancer cells in a compound- and cell-specific manner; however, this treatment also has the potential to induce nephrotoxic cell injury.


Assuntos
Antineoplásicos/efeitos adversos , Antineoplásicos/uso terapêutico , Epigênese Genética/efeitos dos fármacos , Rim/patologia , Neoplasias/tratamento farmacológico , Neoplasias/genética , Acetilação/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Azacitidina/efeitos adversos , Azacitidina/farmacologia , Azacitidina/uso terapêutico , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Cisplatino/efeitos adversos , Cisplatino/farmacologia , Cisplatino/uso terapêutico , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Docetaxel , Células HEK293 , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/efeitos adversos , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/uso terapêutico , Rim/efeitos dos fármacos , Masculino , Metilação/efeitos dos fármacos , Neoplasias/patologia , Oligopeptídeos/efeitos adversos , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Neoplasias da Próstata/genética , Ratos , Taxoides/efeitos adversos , Taxoides/farmacologia , Taxoides/uso terapêutico
10.
J Dairy Sci ; 99(1): 701-17, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26627861

RESUMO

Overfeeding energy in the dry period can affect glucose metabolism and the energy balance of transition dairy cows with potential detrimental effects on the ability to successfully adapt to early lactation. The objectives of this study were to investigate the effect of different dry cow feeding strategies on glucose tolerance and on resting concentrations of blood glucose, glucagon, insulin, nonesterified fatty acids (NEFA), and ß-hydroxybutyrate (BHB) in the peripartum period. Cows entering second or greater lactation were enrolled at dry-off (57 d before expected parturition) into 1 of 3 treatment groups following a randomized block design: cows that received a total mixed ration (TMR) formulated to meet but not exceed energy requirements during the dry period (n=28, controlled energy); cows that received a TMR supplying approximately 150% of energy requirements during the dry period (n=28, high energy); and cows that were fed the same diet as the controlled energy group for the first 28 d, after which the TMR was formulated to supply approximately 125% of energy requirements until calving (n=28, intermediate energy). Intravenous glucose tolerance tests (IVGTT) with rapid administration of 0.25 g of glucose/kg of body weight were performed 28 and 10d before expected parturition, as well as at 4 and 21 d after calving. Area under the curve for insulin and glucose, maximal concentration and time to half-maximal concentration of insulin and glucose, and clearance rates were calculated. Insulin resistance (IR) indices were calculated from baseline samples obtained during IVGTT and Spearman rank correlations determined between IVGTT parameters and IR indices. Treatment did not affect IVGTT parameters at any of the 4 time points. Correlation between IR indices and IVGTT parameters was generally poor. Overfeeding cows energy in excess of predicted requirements by approximately 50% during the entire dry period resulted in decreased postpartum basal plasma glucose and insulin, as well as increased glucagon, BHB, and NEFA concentrations after calving compared with cows fed a controlled energy diet during the dry period. In conclusion, overfeeding energy during the entire dry period or close-up period alone did not affect glucose tolerance as assessed by IVGTT but energy uptake during the dry period was associated with changes in peripartal resting concentrations of glucose, as well as postpartum insulin, glucagon, NEFA, and BHB concentrations.


Assuntos
Glicemia/metabolismo , Bovinos/fisiologia , Dieta/veterinária , Metabolismo Energético , Teste de Tolerância a Glucose/veterinária , Ácido 3-Hidroxibutírico/sangue , Animais , Peso Corporal , Ácidos Graxos não Esterificados/sangue , Feminino , Glucagon/sangue , Insulina/sangue , Lactação , Necessidades Nutricionais , Parto , Período Periparto/sangue
11.
Int J Environ Res Public Health ; 12(1): 300-21, 2014 Dec 25.
Artigo em Inglês | MEDLINE | ID: mdl-25547399

RESUMO

Health impact assessments (HIA) promote the consideration of health in a wide range of public decisions. Although each HIA is different, common pathways, evidence bases, and strategies for community engagement tend to emerge in certain sectors, such as urban redevelopment, natural resource extraction, or transportation planning. To date, a limited number of HIAs have been conducted on decisions affecting water resources and waterfronts. This review presents four recent HIAs of water-related decisions in the United States and Puerto Rico. Although the four cases are topically and geographically diverse, several common themes emerged from the consideration of health in water-related decisions. Water resource decisions are characterized by multiple competing uses, inter-institutional and inter-jurisdictional complexity, scientific uncertainty, long time scales for environmental change, diverse cultural and historical human values, and tradeoffs between private use and public access. These four case studies reveal challenges and opportunities of examining waterfront decisions through a "health lens". This review analyzes these cases, common themes, and lessons learned for the future practice of HIA in the waterfront zone and beyond.


Assuntos
Planejamento em Saúde Comunitária/métodos , Política Ambiental , Avaliação do Impacto na Saúde/métodos , Abastecimento de Água , Meio Ambiente , Política de Saúde , Humanos , Saúde Pública , Porto Rico , Rios , Estados Unidos
12.
Mol Pharm ; 11(10): 3443-51, 2014 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-25189995

RESUMO

The M-type phospholipase A2 receptor (PLA2R1) is a member of the C-type lectin superfamily and can internalize secreted phospholipase A2 (sPLA2) via endocytosis in non-cancer cells. sPLA2 itself was recently shown to be overexpressed in prostate tumors and to be a possible mediator of metastasis; however, little is known about the expression of PLA2R1 or its function in prostate cancers. Thus, we examined PLA2R1 expression in primary prostate cells (PCS-440-010) and human prostate cancer cells (LNCaP, DU-145, and PC-3), and we determined the effect of PLA2R1 knockdown on cytotoxicity induced by free or liposome-encapsulated chemotherapeutics. Immunoblot analysis demonstrated that the expression of PLA2R1 was higher in prostate cancer cells compared to that in primary prostate cells. Knockdown of PLA2R1 expression in PC-3 cells using shRNA increased cell proliferation and did not affect the toxicity of cisplatin, doxorubicin (Dox), and docetaxel. In contrast, PLA2R1 knockdown increased the in vitro toxicity of Dox encapsulated in sPLA2 responsive liposomes (SPRL) and correlated with increased Dox and SPRL uptake. Knockdown of PLA2R1 also increased the expression of Group IIA and X sPLA2. These data show the novel findings that PLA2R1 is expressed in prostate cancer cells, that PLA2R1 expression alters cell proliferation, and that PLA2R1 modulates the behavior of liposome-based nanoparticles. Furthermore, these studies suggest that PLA2R1 may represent a novel molecular target for controlling tumor growth or modulating delivery of lipid-based nanomedicines.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Lipossomos/administração & dosagem , Neoplasias da Próstata/enzimologia , Receptores da Fosfolipase A2/metabolismo , Western Blotting , Linhagem Celular Tumoral , Humanos , Masculino , Nanopartículas/química , Receptores da Fosfolipase A2/genética , Células Tumorais Cultivadas
13.
Toxicol Sci ; 141(2): 432-40, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25015661

RESUMO

This study tested the hypothesis that bromate (KBrO3)-induced renal cell death is mediated by epigenetic mechanisms. Global DNA methylation, as assessed by 5-methylcytosine staining, was not changed in normal rat kidney cells treated with acute cytotoxic doses of KBrO3 (100 and 200 ppm), as compared with controls. However, KBrO3 treatment did increase p38, p53 and histone 2AX (H2AX) phosphorylation, and p21 expression. Treatment of cells with inhibitors of DNA methyltransferase (5-azacytidine or 5-Aza) and histone deacetylase (trichostatin A or TSA) in addition to KBrO3 increased cytotoxicity, as compared with cells exposed to KBrO3 alone. 5-Aza and TSA co-treatment did not alter p38 or p53 phosphorylation, but slightly decreased H2AX phosphorylation and significantly decreased p21 expression. We also assessed epigenetic changes in cells treated under sub-chronic conditions with environmentally relevant concentrations of KBrO3. Under these conditions (0-10ppm KBrO3 for up to 18 days), we detected no increases in cell death or DNA damage. In contrast, slight alterations were detected in the phosphorylation of H2AX, p38, and p53. Sub-chronic low-dose KBrO3 treatment also induced a biphasic response in p21 expression, with lower concentrations increasing expression, but higher concentrations decreasing expression. Methylation-specific PCR demonstrated that sub-chronic KBrO3 treatment altered the methylation of cytosine bases in the p21 gene, as compared with controls, correlating to alterations in p21 protein expression. Collectively, these data show the novel finding that KBrO3-induced renal cell death is altered by inhibitors of epigenetic modifying enzymes and that KBrO3 itself induces epigenetic changes in the p21 gene.


Assuntos
Bromatos/toxicidade , Inibidor de Quinase Dependente de Ciclina p21/genética , Epigênese Genética/efeitos dos fármacos , Rim/efeitos dos fármacos , Animais , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Metilases de Modificação do DNA/antagonistas & inibidores , Metilases de Modificação do DNA/metabolismo , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica , Células HEK293 , Inibidores de Histona Desacetilases/toxicidade , Histonas/metabolismo , Humanos , Rim/metabolismo , Rim/patologia , Fosforilação , Ratos , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
14.
Clin Oncol (R Coll Radiol) ; 26(8): 473-87, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24721444

RESUMO

Squamous cell cancer of the anal canal is a rare tumour for which there remains uncertainty regarding optimal therapy. A systematic review was conducted to summarise the evidence examining concurrent chemotherapy and radiotherapy or different chemotherapy regimens in combination with radiotherapy. MEDLINE, EMBASE and conference proceedings were searched for relevant randomised controlled trials. Outcomes of interest were colostomy rate, local failure, overall survival, disease-free survival, adverse effects and quality of life. Six randomised controlled trials were identified. Two trials reported lower colostomy and local failure rates for concurrent 5-fluorouracil (5-FU) plus mitomycin C (MMC) and radiotherapy compared with radiotherapy alone. The omission of MMC from this regimen resulted in higher colostomy and local failure rates and lower disease-free survival. Induction chemotherapy followed by concurrent 5-FU plus cisplatin and radiotherapy resulted in a higher colostomy rate than concurrent 5-FU plus MMC and radiotherapy. Haematological toxicity rates were lower in patients who received radiotherapy with 5-FU alone or 5-FU plus cisplatin compared with 5-FU plus MMC. No benefit was seen for the addition of induction or maintenance chemotherapy to concurrent chemoradiotherapy. The available evidence continues to support the use of radiotherapy with concurrent 5-FU and MMC as standard treatment for cancer of the anal canal to decrease colostomy and local failure rates.


Assuntos
Neoplasias do Ânus/radioterapia , Neoplasias de Células Escamosas/radioterapia , Neoplasias do Ânus/tratamento farmacológico , Quimiorradioterapia/métodos , Humanos , Neoplasias de Células Escamosas/tratamento farmacológico
15.
Clin Oncol (R Coll Radiol) ; 26(4): 203-9, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24462333

RESUMO

AIMS: To determine the efficacy of induction gemcitabine followed by biweekly gemcitabine concurrent with radiotherapy for locally advanced pancreatic cancer. MATERIALS AND METHODS: Between March 2001 and August 2009, 90 patients with unresectable (78) or resected (12) pancreatic cancer were treated with a standard treatment policy of induction gemcitabine (seven doses of weekly gemcitabine at 1000 mg/m(2)) followed by concurrent radiotherapy (52.5 Gy) and biweekly gemcitabine (40 mg/m(2)). RESULTS: After induction gemcitabine, 17.8% of patients did not proceed to chemoradiotherapy, due to either disease progression, performance status deterioration or gemcitabine toxicity. Of the patients who received chemoradiotherapy, 68.9% completed the course of 52.5 Gy, whereas 79.7% received more than 45 Gy. Chemoradiotherapy was stopped early due to treatment toxicity in 22.9% of patients. On intention to treat analysis, the median overall survival was 12.7 months in the locally advanced group and 18.2 months in the resected group. On multivariate analysis for the unresectable patients, a larger gross tumour volume was a significant poor prognostic factor for overall survival and local progression-free survival. CONCLUSION: This large series confirms, in a standard practice setting, similar efficacy and tolerability of treatment as previously reported in our phase I-II study. The benefit to patients with a gross tumour volume >48 cm(3) may be limited.


Assuntos
Antimetabólitos Antineoplásicos/administração & dosagem , Desoxicitidina/análogos & derivados , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/radioterapia , Radiossensibilizantes/administração & dosagem , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia , Desoxicitidina/administração & dosagem , Intervalo Livre de Doença , Esquema de Medicação , Feminino , Humanos , Quimioterapia de Indução , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Análise de Sobrevida , Gencitabina , Neoplasias Pancreáticas
16.
Eur J Surg Oncol ; 40(6): 739-46, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24246611

RESUMO

BACKGROUND: The role of curative-intent surgery for retroperitoneal recurrence (RPR) of colorectal cancer (CRC) remains controversial. We previously showed 0% mortality and acceptable morbidity in patients who underwent resection of RPR.(1) Here we examine long-term overall and disease-free survival (OS, DFS). METHODS: We identified patients who underwent resection for RPR of CRC between 01/1999 and 02/2010 from two prospective CRC databases. RESULTS: The study cohort was composed of 48 patients (26 women) whose median age was 60 (36-80) years. Eleven patients had previously undergone resection of a different focus of disease recurrence, and 8 patients had additional site(s) of distant metastatic disease at the time of RPR resection. Following surgery for RPR, 5 patients were left with gross residual disease, and 6 had microscopically positive margins. Median follow-up was 32 (3-127) months. At last follow-up, 13 patients had died of cancer and 1 of other causes. For the entire cohort of 48 patients, 5-year OS was 70% (median 80 mo). In univariate analysis, OS was reduced in younger patients (p = 0.003) and in those with gross residual disease (p = 0.033). In patients who had grossly complete resection, 5-year DFS was 49% (median 38 mo). Predictors of reduced DFS on multivariable analysis were young age and R1 resection. CONCLUSION: OS and DFS after resection of RPR in well-selected patients were favorable. Patients with RPR of CRC should be considered for curative-intent surgery with careful discussion at multidisciplinary cancer conference.


Assuntos
Neoplasias Colorretais/cirurgia , Recidiva Local de Neoplasia/cirurgia , Neoplasias Retroperitoneais/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Colorretais/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/patologia , Reoperação/estatística & dados numéricos , Neoplasias Retroperitoneais/patologia , Estudos Retrospectivos , Taxa de Sobrevida , Resultado do Tratamento
17.
Toxicol In Vitro ; 27(3): 1018-24, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23376802

RESUMO

Aberrant major histocompatibility complex class II (MHC-II) surface expression on antigen presenting cells (APCs) is associated with dysregulated immune homeostasis. Lead (Pb) is known to increase MHC-II surface expression on murine peritoneal macrophages ex vivo at concentrations exceeding 25 µM. Little data exist examining this effect at physiologically relevant concentrations. To address this deficit, we examined the effects of Pb on MHC-II surface expression, secondary T-cell activation markers (CD80, CD86, CD40), cell viability, cellular metabolic activity, and ß-hexosaminidase activity in RAW 267.4 macrophage cell lines, with changes in cell ultrastructure evaluated by electron and confocal microscopy. Pb induced an increase in MHC-II, CD86, and lysosome-associated LAMP-1 and LAMP-2 surface mean expression during one doubling cycle (17 h), which was mirrored by increased ß-hexosaminidase activity. Although cell viability was unaffected, cellular metabolism was inhibited. Electron microscopy revealed evidence of lipid vacuolization, macroautophagy and myelin figure formation in cells cultured with either Pb or LPS. Confocal microscopy with antibodies against LC3B showed a punctate pattern consistent with the presence of mature autophagosomes. Collectively, these data suggest that 2.5-5.0 µM Pb increased MHC-II surface expression by inhibiting metabolic activity, inducing autophagy, and increasing MHC-II trafficking in a macrophage cell line.


Assuntos
Poluentes Ambientais/toxicidade , Antígenos de Histocompatibilidade Classe II/metabolismo , Chumbo/toxicidade , Animais , Antígenos CD/metabolismo , Autofagia/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Exocitose/efeitos dos fármacos , Proteína 2 de Membrana Associada ao Lisossomo/metabolismo , Proteínas de Membrana Lisossomal/metabolismo , Camundongos , beta-N-Acetil-Hexosaminidases/metabolismo
18.
Diabetologia ; 56(4): 803-13, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23404441

RESUMO

AIMS/HYPOTHESIS: Previous studies on isolated islets have demonstrated tight coupling between calcium (Ca(2+)) influx and oxygen consumption rate (OCR) that is correlated with insulin secretion rate (ISR). To explain these observations, we have proposed a mechanism whereby the activation of a highly energetic process (Ca(2+)/metabolic coupling process [CMCP]) by Ca(2+) mediates the stimulation of ISR. The aim of the study was to test whether impairment of the CMCP could play a role in the development of type 2 diabetes. METHODS: Glucose- and Ca(2+)-mediated changes in OCR and ISR in isolated islets were compared with the time course of changes of plasma insulin concentrations observed during the progression to hyperglycaemia in a rat model of type-2 diabetes (the University of California at Davis type 2 diabetes mellitus [UCD-T2DM] rat). Islets were isolated from UCD-T2DM rats before, 1 week, and 3 weeks after the onset of hyperglycaemia. RESULTS: Glucose stimulation of cytosolic Ca(2+) and OCR was similar for islets harvested before and 1 week after the onset of hyperglycaemia. In contrast, a loss of decrement in islet OCR and ISR in response to Ca(2+) channel blockade coincided with decreased fasting plasma insulin concentrations observed in rats 3 weeks after the onset of hyperglycaemia. CONCLUSIONS/INTERPRETATION: These results suggest that phenotypic impairment of diabetic islets in the UCD-T2DM rat is downstream of Ca(2+) influx and involves unregulated stimulation of the CMCP. The continuously elevated levels of CMCP induced by chronic hyperglycaemia in these islets may mediate the loss of islet function.


Assuntos
Cálcio/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Hiperglicemia/metabolismo , Insulina/metabolismo , Animais , Citocromos c/metabolismo , Citosol/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/patologia , Glucose/metabolismo , Secreção de Insulina , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Masculino , Consumo de Oxigênio , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
19.
Integr Biol (Camb) ; 5(1): 172-82, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22890797

RESUMO

Secretory phospholipase A(2) (sPLA(2)) cleave phospholipids at sn-2 ester bonds, releasing lysophospholipids and fatty acids, and are over expressed in several pathologies, including inflammation, arthritis, sepsis and breast and prostate cancers. Herein we evaluated the therapeutic activity of liposomes engineered to be responsive to different sPLA(2) isoforms compared to clinically used long-circulating (pegylated) sterically stabilized liposomes (SSL) in vitro and in vivo, and assessed differences in roles of sPLA(2) in the mechanism of uptake and delivery of these nanoparticles. Exposing sPLA(2) responsive liposomes (SPRL) to sPLA(2) increased the release of intraluminal entrapped contents in a time-dependent manner that was inhibited by the sPLA(2) inhibitor LY3117273. Treatment of prostate cancer cells with doxorubicin encapsulated in SSL and SPRL resulted in cytotoxicity in LNCaP, DU-145 and PC-3 cells lines comparable to free drug. Interestingly, cytotoxicity was not altered by sPLA(2) inhibition. Tracking of drug and liposome delivery using fluorescence microscopy and flow cytometry, we demonstrated that drug uptake was liposome-dependent, as encapsulation of doxorubicin in SPRL resulted in 1.5 to 2-fold greater intracellular drug levels compared to SSL. Liposome uptake was cell-dependent and did not correlate to doxorubicin uptake; however, doxorubicin uptake was generally greatest in PC-3 cells, followed by DU-145 cells and then LNCaP cells. In almost all cases, uptake of one of our formulations, SPRL-E, was greater than SSL. The therapeutic activity of SPRL in vivo was demonstrated using a mouse xenograft model of human prostate cancer, which showed that doxorubicin entrapped within SPRL decreased tumor growth compared to SSL, suggesting that SPRL are more effective at slowing tumor growth than a SSL formulation similar to the FDA approved DOXIL™. Collectively, these data show the therapeutic activity of SPRL compared to SSL, yield insights into the mechanisms of action of these nanoparticles and suggest that SPRL could be useful for treatment of other pathologies that over express sPLA(2).


Assuntos
Lipossomos/farmacocinética , Lipossomos/uso terapêutico , Nanopartículas/uso terapêutico , Fosfolipases A2 Secretórias/antagonistas & inibidores , Fosfolipases A2 Secretórias/metabolismo , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/metabolismo , Animais , Linhagem Celular Tumoral , Humanos , Masculino , Camundongos , Camundongos Nus , Neoplasias da Próstata/patologia , Resultado do Tratamento
20.
Diabetes Obes Metab ; 15(7): 607-12, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23216672

RESUMO

There is a pressing need for new effective therapeutic strategies for addressing the epidemic of type 2 diabetes. Leptin has been shown to reduce hyperglycaemia in rodent models of type 1 diabetes and has recently been shown to normalize fasting plasma glucose concentrations in a rodent model of polygenic obesity and type 2 diabetes. Overall, these findings suggest that leptin may be an effective therapeutic option for both type 1 and type 2 diabetes. However, short-term human clinical studies in overweight and obese patients with recently diagnosed type 2 diabetes have reported minimal efficacy of leptin administration to lower blood glucose levels. Herein, the role of leptin in the maintenance of glucose homeostasis and the potential use of leptin in the treatment of type 2 diabetes are discussed.


Assuntos
Diabetes Mellitus Tipo 2/tratamento farmacológico , Hipoglicemiantes/uso terapêutico , Leptina/uso terapêutico , Animais , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Hipoglicemiantes/química , Hipoglicemiantes/metabolismo , Leptina/análogos & derivados , Leptina/metabolismo , Obesidade/complicações
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