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1.
Eur Rev Med Pharmacol Sci ; 22(18): 5874-5891, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30280768

RESUMO

OBJECTIVE: Renal Cell Carcinoma (RCC) is the most common malignancy in adult kidneys. The American Cancer Society estimated 62,700 new cases and 14,240 deaths in 2018. Although early detection has improved in recent years, the treatment remains a challenge and reliable biomarkers for poor outcomes become necessary for the prevention of metastases and improve the quality of patients' life during and after treatment. Then, the current status of the search for new RCC biomarkers was discussed, as well as the latest discoveries in the RCC risk and metastatic treatment were discussed in this review. MATERIALS AND METHODS: Extensive research was carried out in the online databases and full-free text articles published in the last 5 years, or more when convenient, were evaluated. Articles were included that addressed the proposed theme and were published in the English language. RESULTS: The present state of knowledge on biomarkers for RCC carcinogenesis and progression is still much to be understood about RCC risk factors and molecular pathways resulting in metastatic progression. Newest RCC target therapies were discussed, mainly in relation to immunological therapy, and vaccines that have been tested in numerous trials with different cancer types. CONCLUSIONS: The development of targeted therapies has revolutionized the treatment of advanced and metastatic cancers or non-responder patients. Combined therapy between classical chemotherapy and adjuvant immunotherapies has been modifying the cancer patients prognosis and bringing the hope of a cure in many cases.


Assuntos
Biomarcadores Tumorais/genética , Carcinoma de Células Renais/genética , Neoplasias Renais/genética , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Carcinoma de Células Renais/tratamento farmacológico , Ensaios Clínicos como Assunto , Progressão da Doença , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Neoplasias Renais/tratamento farmacológico , Metástase Neoplásica
2.
Int J Lab Hematol ; 40(1): 56-65, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28880455

RESUMO

OBJECTIVES: Automated cell counters have replaced manual enumeration of cells in blood and most body fluids. However, due to the unreliability of automated methods at very low cell counts, most laboratories continue to perform labor-intensive manual counts on many or all cerebrospinal fluid (CSF) samples. This multicenter clinical trial investigated if the GloCyte System (Advanced Instruments, Norwood, MA), a recently FDA-approved automated cell counter, which concentrates and enumerates red blood cells (RBCs) and total nucleated cells (TNCs), is sufficiently accurate and precise at very low cell counts to replace all manual CSF counts. METHODS: The GloCyte System concentrates CSF and stains RBCs with fluorochrome-labeled antibodies and TNCs with nucleic acid dyes. RBCs and TNCs are then counted by digital image analysis. Residual adult and pediatric CSF samples obtained for clinical analysis at five different medical centers were used for the study. Cell counts were performed by the manual hemocytometer method and with the GloCyte System following the same protocol at all sites. The limits of the blank, detection, and quantitation, as well as precision and accuracy of the GloCyte, were determined. RESULTS: The GloCyte detected as few as 1 TNC/µL and 1 RBC/µL, and reliably counted as low as 3 TNCs/µL and 2 RBCs/µL. The total coefficient of variation was less than 20%. Comparison with cell counts obtained with a hemocytometer showed good correlation (>97%) between the GloCyte and the hemocytometer, including at very low cell counts. CONCLUSIONS: The GloCyte instrument is a precise, accurate, and stable system to obtain red cell and nucleated cell counts in CSF samples. It allows for the automated enumeration of even very low cell numbers, which is crucial for CSF analysis. These results suggest that GloCyte is an acceptable alternative to the manual method for all CSF samples, including those with normal cell counts.


Assuntos
Líquido Cefalorraquidiano , Contagem de Eritrócitos , Eritrócitos , Leucócitos , Contagem de Eritrócitos/instrumentação , Contagem de Eritrócitos/métodos , Feminino , Humanos , Contagem de Leucócitos/instrumentação , Contagem de Leucócitos/métodos , Masculino , Sensibilidade e Especificidade
3.
J Evol Biol ; 30(9): 1748-1762, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28667661

RESUMO

In response to parasite exposure, organisms from a variety of taxa undergo a shift in reproductive investment that may trade off with other life-history traits including survival and immunity. By suppressing reproduction in favour of somatic and immunological maintenance, hosts can enhance the probability of survival and recovery from infection. By plastically enhancing reproduction through terminal investment, on the other hand, hosts under the threat of disease-induced mortality could enhance their lifetime reproductive fitness through reproduction rather than survival. However, we know little about the evolution of these strategies, particularly when hosts can recover and even bequeath protection to their offspring. In this study, we develop a stochastic agent-based model that competes somatic maintenance and terminal investment strategies as they trade off differentially with lifespan, parasite resistance, recovery and transgenerational immune priming. Our results suggest that a trade-off between reproduction and recovery can drive directional selection for either terminal investment or somatic maintenance, depending on the cost of reproduction to lifespan. However, some conditions, such as low virulence with a high cost of reproduction to lifespan, can favour diversifying selection for the coexistence of both strategies. The introduction of transgenerational priming into the model favours terminal investment when all strategies are equally likely to produce primed offspring, but favours somatic maintenance if it confers even a slight priming advantage over terminal investment. Our results suggest that both immune priming and recovery may modulate the evolution of reproductive shift diversity and magnitude upon exposure to parasites.


Assuntos
Aptidão Genética , Interações Hospedeiro-Parasita , Reprodução , Animais , Longevidade
4.
Sci Rep ; 6: 32123, 2016 08 24.
Artigo em Inglês | MEDLINE | ID: mdl-27555217

RESUMO

From visible to mid-infrared frequencies, molecular sensing has been a major successful application of plasmonics because of the enormous enhancement of the surface electromagnetic nearfield associated with the induced collective motion of surface free carriers excited by the probe light. However, in the lower-energy terahertz (THz) region, sensing by detecting molecular vibrations is still challenging because of low sensitivity, complicated spectral features, and relatively little accumulated knowledge of molecules. Here, we report the use of a micron-scale thin-slab metamaterial (MM) architecture, which functions as an amplifier for enhancing the absorption signal of the THz vibration of an ultrathin adsorbed layer of large organic molecules. We examined bovine serum albumin (BSA) as a prototype large protein molecule and Rhodamine 6G (Rh6G) and 3,3'-diethylthiatricarbocyanine iodide (DTTCI) as examples of small molecules. Among them, our MM significantly magnified only the signal strength of bulky BSA. On the other hand, DTTCI and Rh6G are inactive, as they lack low-frequency vibrational modes in this frequency region. The results obtained here clearly demonstrate the promise of MM-enhanced absorption spectroscopy in the THz region for detection and structural monitoring of large biomolecules such as proteins or pathogenic enzymes.


Assuntos
Proteínas/análise , Espectroscopia Terahertz/métodos , Benzotiazóis/análise , Carbocianinas/análise , Rodaminas/análise , Soroalbumina Bovina/análise , Silício/química , Prata/química , Espectroscopia Terahertz/instrumentação , Vibração
5.
Ann Oncol ; 27(7): 1329-36, 2016 07.
Artigo em Inglês | MEDLINE | ID: mdl-27217540

RESUMO

BACKGROUND: While studies have shown that poor oral health status may increase the risk of cancer, evidence of a specific association with the risk of colorectal cancer (CRC) is inconclusive. We evaluated the association between oral health and CRC risk using data from three large cohorts: the Shanghai Men's Health Study (SMHS), the Shanghai Women's Health Study (SWHS), and the Southern Community Cohort Study (SCCS), and carried out a meta-analysis of results from other relevant published studies. PATIENTS AND METHODS: This study applied a nested case-control study design and included 825 cases/3298 controls from the SMHS/SWHS and 238 cases/2258 controls from the SCCS. The association between oral health status (i.e. tooth loss/tooth decay) and CRC risk was assessed using conditional logistic regression models. A meta-analysis was carried out based on results from the present study and three published studies. RESULTS: We found that tooth loss was not associated with increased risk of CRC. ORs and respective 95% CIs associated with loss of 1-5, 6-10, and >10 teeth compared with those with full teeth are 0.87 (0.69-1.10), 0.93 (0.70-1.24), and 0.85 (0.66-1.11) among SMHS/SWHS participants; and 1.13 (0.72-1.79), 0.87 (0.52-1.43), and 1.00 (0.63-1.58) for those with loss of 1-4, 5-10, and >10 teeth among SCCS participants. Data regarding tooth decay were available in the SCCS, but were not associated with CRC risk. Meta-analysis confirmed the null association between tooth loss/periodontal disease and CRC risk (OR 1.05, 95% CI 0.86-1.29). CONCLUSION: In this analysis of three cohorts and a meta-analysis, we found no evidence supporting an association between oral health and CRC risk.


Assuntos
Neoplasias Colorretais/epidemiologia , Saúde Bucal , Higiene Bucal/efeitos adversos , Perda de Dente/epidemiologia , China/epidemiologia , Neoplasias Colorretais/patologia , Feminino , Humanos , Modelos Logísticos , Masculino , Fatores de Risco , Perda de Dente/patologia
7.
Gene Ther ; 21(7): 629-37, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24784448

RESUMO

Recombinant adenoviruses are one of the most common vehicles for efficient in vitro and in vivo gene deliveries. Here, we investigate whether exogenous precursor terminal protein (pTP) expression in 293 cells improves the efficiency of adenovirus packaging and amplification. We used a piggyBac transposon-based vector and engineered a stable 293 line that expresses high level of Ad5 pTP, designated as 293pTP. Using the AdBMP6-GLuc that expresses green fluorescent protein (GFP), BMP6 and Gaussia luciferase, we found that the infectivity of AdBMP6-GLuc viral samples packaged in 293pTP cells was titrated up to 19.3 times higher than that packaged in parental 293 cells. AdBMP6-GLuc viral samples packaged in 293pTP cells exhibited significantly higher transduction efficiency in 143B and immortalized mouse embryonic fibroblast (iMEF) cells, as assessed by fluorescence-activated cell sorting analysis of GFP-positive cells, the luciferase activity assay and BMP6-induced osteogenic marker alkaline phosphatase activities in iMEFs. When adenovirus amplification efficiency was analyzed, we found that 293pTP cells infected with AdBMP6-GLuc yielded up to 12.6 times higher titer than that in parental 293 cells, especially at lower multiplicities of infection. These results strongly suggest that exogenous pTP expression may accelerate the packaging and amplification of recombinant adenoviruses. Thus, the engineered 293pTP cells should be a superior packaging line for efficient adenovirus production.


Assuntos
Adenoviridae/fisiologia , Fosfoproteínas/metabolismo , Precursores de Proteínas/metabolismo , Proteínas Virais/metabolismo , Montagem de Vírus , Adenoviridae/genética , Infecções por Adenoviridae/virologia , Animais , Linhagem Celular Tumoral , Embrião de Mamíferos/metabolismo , Fibroblastos/citologia , Fibroblastos/virologia , Vetores Genéticos , Células HEK293 , Humanos , Células-Tronco Mesenquimais/virologia , Camundongos , Recombinação Genética , Transdução Genética
8.
Br J Cancer ; 108(5): 1173-7, 2013 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-23422755

RESUMO

BACKGROUND: Although the independent effects of smoking status and HAART are reported as lower risks against KS, their combined effects have not been explored. We examined whether there is an interaction between smoking status and HAART use on the risk of KS development in an on-going US cohort of HIV-infected men. METHODS: Cox proportional hazards regression was used to analyse a total sample of 2736 participants of the Multicenter AIDS Cohort Study (MACS). RESULTS: We identified 530 incident KS cases with a total follow-up time of 26 594 person-years (incidence rate: 2.00 out of 100 person-years). Current smoking status and HAART use were independently associated with a lower risk of KS development (hazard ratio - HR=0.56, 95% CI: 0.35-0.90, P=0.02 and HR=0.27, 95% CI: 0.16-0.48, P<0.0001, respectively). There was no evidence of multiplicative interaction between current smoking status and HAART use on KS risk (HR=2.14, 95% CI: 0.97-4.73, Pinteraction=0.06). Lower effect of smoking was only present among those not on HAART (HR=0.57, 95% CI: 0.35-0.92, P=0.02). CONCLUSION: The inverse association of cigarette smoking on KS risk may be limited to those not on HAART. The biological mechanism of smoking in KS carcinogenesis should be elucidated.


Assuntos
Terapia Antirretroviral de Alta Atividade , Infecções por HIV/tratamento farmacológico , Sarcoma de Kaposi/epidemiologia , Fumar , Adulto , Idoso , Estudos de Coortes , Infecções por HIV/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Sarcoma de Kaposi/complicações , Estados Unidos/epidemiologia
9.
Nat Prod Commun ; 8(11): 1507-8, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24427927

RESUMO

Three new sodium salts of iridoid acids, deacetylasperulosidic acid sodium salt (1), teneoside D (2), and teneoside E (3) were isolated from the leaves of Hedyotis tenelliflora Blume (Rubiaceae), together with seven known iridoids, 6alpha-hydroxygeniposide (4), 6beta-hydroxygeniposide (5), 6-O-methyldeacetylasperulosidic acid methyl ester (6), 6-O-methylscandoside methyl ester (7), 6alpha-methoxygeniposidic acid (8), daphylloside (9), and mollugoside methyl ester (10). Their chemical structures were elucidated by 1D and 2D NMR spectroscopy, as well as HR-ESI-MS analysis.


Assuntos
Glucosídeos/isolamento & purificação , Hedyotis/química , Iridoides/isolamento & purificação , Glucosídeos/química , Iridoides/química , Espectroscopia de Ressonância Magnética , Espectrometria de Massas por Ionização por Electrospray , Vietnã
10.
Int J STD AIDS ; 23(11): 792-8, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23155099

RESUMO

While the association between smoking and human papillomavirus infection, cervical cancer, and anal cancer has been well studied, evidence on the association between cigarette smoking and anal warts is limited. The purpose of this study was to investigate if cigarette smoking status influences the size of anal warts over time in HIV-infected women in a sample of 976 HIV-infected women from the Women's Interagency HIV Study (WIHS). A linear mixed model was used to determine the effect of smoking on anal wart size. Even though women who were currently smokers had larger anal warts at baseline and slower growth rate of anal wart size after each visit than women who were not current smokers, there was no association between size of anal wart and current smoking status over time. Further studies on the role of smoking and interaction between smoking and other risk factors, however, should be explored.


Assuntos
Neoplasias do Ânus/epidemiologia , Neoplasias do Ânus/patologia , Infecções por HIV/complicações , Fumar/efeitos adversos , Verrugas/epidemiologia , Verrugas/patologia , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Adulto Jovem
11.
Oncogene ; 30(37): 3907-17, 2011 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-21460855

RESUMO

Osteosarcoma (OS) is the most common primary malignancy of bone. There is a critical need to identify the events that lead to the poorly understood mechanism of OS development and metastasis. The goal of this investigation is to identify and characterize a novel marker of OS progression. We have established and characterized a highly metastatic OS subline that is derived from the less metastatic human MG63 line through serial passages in nude mice via intratibial injections. Microarray analysis of the parental MG63, the highly metastatic MG63.2 subline, as well as the corresponding primary tumors and pulmonary metastases revealed insulin-like growth factor binding protein 5 (IGFBP5) to be one of the significantly downregulated genes in the metastatic subline. Confirmatory quantitative RT-PCR on 20 genes of interest demonstrated IGFBP5 to be the most differentially expressed and was therefore chosen to be one of the genes for further investigation. Adenoviral mediated overexpression and knockdown of IGFBP5 in the MG63 and MG63.2 cell lines, as well as other OS lines (143B and MNNG/HOS) that are independent of our MG63 lines, were employed to examine the role of IGFBP5. We found that overexpression of IGFBP5 inhibited in vitro cell proliferation, migration and invasion of OS cells. Additionally, IGFBP5 overexpression promoted apoptosis and cell cycle arrest in the G1 phase. In an orthotopic xenograft animal model, overexpression of IGFBP5 inhibited OS tumor growth and pulmonary metastases. Conversely, siRNA-mediated knockdown of IGFBP5 promoted OS tumor growth and pulmonary metastases in vivo. Immunohistochemical staining of patient-matched primary and metastatic OS samples demonstrated decreased IGFBP5 expression in the metastases. These results suggest 1) a role for IGFBP5 as a novel marker that has an important role in the pathogenesis of OS, and 2) that the loss of IGFBP5 function may contribute to more metastatic phenotypes in OS.


Assuntos
Neoplasias Ósseas/metabolismo , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Neoplasias Pulmonares/metabolismo , Osteossarcoma/metabolismo , Adolescente , Adulto , Animais , Apoptose , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Criança , Regulação para Baixo , Feminino , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/secundário , Masculino , Camundongos , Camundongos Nus , Osteossarcoma/genética , Osteossarcoma/secundário , Adulto Jovem
12.
Haemophilia ; 16(6): 866-77, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20579113

RESUMO

Postauthorization safety surveillance of factor VIII (FVIII) concentrates is essential for assessing rare adverse event incidence. We determined safety and efficacy of ADVATE [antihaemophilic factor (recombinant), plasma/albumin-free method, (rAHF-PFM)] during routine clinical practice. Subjects with differing haemophilia A severities and medical histories were monitored during 12 months of prophylactic and/or on-demand therapy. Among 408 evaluable subjects, 386 (95%) received excellent/good efficacy ratings for all on-demand assessments; the corresponding number for subjects with previous FVIII inhibitors was 36/41 (88%). Among 276 evaluable subjects receiving prophylaxis continuously in the study, 255 (92%) had excellent/good ratings for all prophylactic assessments; the corresponding number for subjects with previous FVIII inhibitors was 41/46 (89%). Efficacy of surgical prophylaxis was excellent/good in 16/16 evaluable procedures. Among previously treated patients (PTPs) with >50 exposure days (EDs) and FVIII≤2%, three (0.75%) developed low-titre inhibitors. Two of these subjects had a positive inhibitor history; thus, the incidence of de novo inhibitor formation in PTPs with FVIII≤2% and no inhibitor history was 1/348 (0.29%; 95% CI, 0.01-1.59%). A PTP with moderate haemophilia developed a low-titre inhibitor. High-titre inhibitors were reported in a PTP with mild disease (following surgery), a previously untreated patient (PUP) with moderate disease (following surgery) and a PUP with severe disease. The favourable benefit/risk profile of rAHF-PFM previously documented in prospective clinical trials has been extended to include a broader range of haemophilia patients, many of whom would have been ineligible for registration studies.


Assuntos
Inibidores dos Fatores de Coagulação Sanguínea/análise , Fator VIII/uso terapêutico , Hemofilia A/tratamento farmacológico , Adolescente , Adulto , Criança , Pré-Escolar , Fator VIII/efeitos adversos , Feminino , Hemofilia A/sangue , Hemorragia/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Vigilância de Produtos Comercializados , Proteínas Recombinantes , Estados Unidos
13.
Haemophilia ; 10 Suppl 2: 10-6, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15385041

RESUMO

The development of neutralizing antibodies to factor VIII or IX therapeutic concentrates remains the most serious and challenging complication in the management of patients with haemophilia A and B. FEIBA, Anti-Inhibitor Coagulant Complex, is an activated prothrombin complex concentrate that has been used to treat patients with such complications for almost 30 years. The mechanism of action of FEIBA has been proposed to involve simultaneous FVIII/FIX inhibitor bypassing action in the common, intrinsic and extrinsic coagulation pathways. FEIBA is derived from human plasma that undergoes stringent viral screening followed by significant viral inactivation and removal. To date, there have been no confirmed reports of transmission of hepatitis A, B or C, or of human immunodeficiency viruses associated with the use of the current, vapour-heat-treated FEIBA concentrate. The incidence of thrombotic adverse events recorded in the Baxter pharmacovigilance database for the 10-year postmarket period (1990-99) was approximately 4 : 100,000 infusions of FEIBA. Almost all documented thrombotic events with FEIBA occurred with doses that exceeded dosing recommendations, and known risk factors for cardiovascular disease were evident in more than 80% of the patients involved. Overall, clinical data have shown FEIBA to be safe and well-tolerated for use in a wide variety of clinical settings, including treatment of bleeding episodes, management of surgical procedures, home therapy, long-term prophylaxis, and prophylaxis during immune tolerance induction, when used according to dosing guidelines.


Assuntos
Fatores de Coagulação Sanguínea/uso terapêutico , Hemofilia A/tratamento farmacológico , Hemofilia B/tratamento farmacológico , Anticorpos/imunologia , Fatores de Coagulação Sanguínea/efeitos adversos , Fatores de Coagulação Sanguínea/imunologia , Fator IX/imunologia , Fator VIII/imunologia , Hemofilia A/imunologia , Hemofilia B/imunologia , Serviços de Assistência Domiciliar , Humanos , Tolerância Imunológica , Hemorragia Pós-Operatória/prevenção & controle , Trombose/etiologia
14.
Gene Ther ; 11(17): 1312-20, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15269709

RESUMO

Efficacious bone regeneration could revolutionize the clinical management of bone and musculoskeletal disorders. Although several bone morphogenetic proteins (BMPs) (mostly BMP-2 and BMP-7) have been shown to induce bone formation, it is unclear whether the currently used BMPs represent the most osteogenic ones. Until recently, comprehensive analysis of osteogenic activity of all BMPs has been hampered by the fact that recombinant proteins are either not biologically active or not available for all BMPs. In this study, we used recombinant adenoviruses expressing the 14 types of BMPs (AdBMPs), and demonstrated that, in addition to currently used BMP-2 and BMP-7, BMP-6 and BMP-9 effectively induced orthotopic ossification when either AdBMP-transduced osteoblast progenitors or the viral vectors were injected into the quadriceps of athymic mice. Radiographic and histological evaluation demonstrated that BMP-6 and BMP-9 induced the most robust and mature ossification at multiple time points. BMP-3, a negative regulator of bone formation, was shown to effectively inhibit orthotopic ossification induced by BMP-2, BMP-6, and BMP-7. However, BMP-3 exerted no inhibitory effect on BMP-9-induced bone formation, suggesting that BMP-9 may transduce osteogenic signaling differently. Our findings suggest that BMP-6 and BMP-9 may represent more effective osteogenic factors for bone regeneration.


Assuntos
Adenoviridae/genética , Doenças Ósseas/terapia , Proteínas Morfogenéticas Ósseas/genética , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Osteogênese/genética , Animais , Proteína Morfogenética Óssea 2 , Proteína Morfogenética Óssea 6 , Proteína Morfogenética Óssea 7 , Linhagem Celular , Vetores Genéticos/genética , Fator 2 de Diferenciação de Crescimento , Injeções Intramusculares , Masculino , Camundongos , Camundongos Nus , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fator de Crescimento Transformador beta/genética
15.
Toxicol Ind Health ; 20(1-5): 41-50, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15807407

RESUMO

The distribution of 14C-bisphenol A (BPA) in plasma and neuroendocrine organs was determined in Fischer 344 female rats following three oral doses (0.1, 10 or 100mg/kg). Plasma and tissue maximum concentrations (Cmax) were reached within 15-30 min of dosing. Plasma areas-under-the-curve (AUC) ranged from 0.06 to 53.9 microg-h/mL. The AUCs of the pituitary gland and uterus/gonads were 16-21% higher than that of plasma. The AUCs of hypothalamus and the rest of the brain were 43.7% and 77% of the plasma AUCs, respectively. In the brain tissue, the exposure increased linearly with the oral dose, as the dose was increased from 0.1 to 10 and 100 mg/kg; the exposure in the brain relative to the plasma increased by factors of 1, 1.19 and 1.24. This indicates that the brain barrier systems do not limit the access of the lipophilic BPA to the brain. The increases of the uterus/gonads relative to the plasma were 1, 1.07 and 1.04. Tissue partitioning was also examined in vitro by the uptake of 14C-BPA. The BPA tissue/blood partition coefficients were as follows: heart, 7.5; liver, 6.1; kidney, 6.4; fat, 3.6; muscle, 2.6; breast, 3.6; ovaries, 9.1; uterus, 5.9; stomach, 5.1; and small intestine, 6.7. The tissue/cerebrospinal fluid partition coefficients were as follows: pituitary gland, 12.8; brain stem, 6.1; cerebellum, 6.4; hippocampus, 7.1; hypothalamus, 6.1; frontal cortex, 4.9; and caudate nucleus, 6.8.


Assuntos
Estrogênios não Esteroides/farmacocinética , Sistemas Neurossecretores/metabolismo , Fenóis/farmacocinética , Administração Oral , Animais , Área Sob a Curva , Compostos Benzidrílicos , Relação Dose-Resposta a Droga , Feminino , Ratos , Ratos Endogâmicos F344 , Distribuição Tecidual
16.
Environ Health Perspect ; 109(11): 1095-101, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11712992

RESUMO

We developed a physiologically based pharmacokinetic (PBPK) model to predict the target organ doses of octamethylcyclotetrasiloxane (D(4)) after intravenous (IV), inhalation, or implantation exposures. The model used (14)C-D(4) IV disposition data in rats to estimate tissue distribution coefficients, metabolism, and excretion parameters. We validated the model by comparing the predicted blood and tissues concentrations of D(4) after inhalation to experimental results in both rats and humans. We then used the model to simulate D(4) kinetics after single and/or repeated D(4) exposures in rats and humans. The model predicted bioaccumulation of D(4) in fatty tissues (e.g., breast), especially in women. Because of its high lipid solubility (Log P(oct/water) = 5.1), D(4) persisted in fat with a half life of 11.1 days after inhalation and 18.2 days after breast implant exposure. Metabolism and excretion remained constant with repeated exposures, larger doses, and/or different routes of exposure. The accumulation of D(4) in fatty tissues should play an important role in the risk assessment of D(4) especially in women exposed daily to multiple personal care products and silicone breast implants.


Assuntos
Adjuvantes Imunológicos/farmacocinética , Modelos Teóricos , Siloxanas/farmacocinética , Tecido Adiposo/química , Adjuvantes Imunológicos/administração & dosagem , Animais , Disponibilidade Biológica , Implantes de Mama , Cosméticos/química , Exposição Ambiental , Humanos , Infusões Intravenosas , Exposição por Inalação , Cinética , Ratos , Medição de Risco , Fatores Sexuais , Silicones/administração & dosagem , Silicones/efeitos adversos , Siloxanas/administração & dosagem , Distribuição Tecidual
17.
J Mol Biol ; 313(1): 181-95, 2001 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-11601855

RESUMO

In order to identify new transmembrane helix packing motifs in naturally occurring proteins, we have selected transmembrane domains from a library of random Escherichia coli genomic DNA fragments and screened them for homomultimerization via their abilities to dimerize the bacteriophage lambda cI repressor DNA-binding domain. Sequences were isolated using a modified lambda cI headpiece dimerization assay system, which was shown previously to measure transmembrane helix-helix association in the E. coli inner membrane. Screening resulted in the identification of several novel sequences that appear to mediate helix-helix interactions. One sequence, representing the predicted sixth transmembrane domain (TM6) of the E. coli protein YjiO, was chosen for further analysis. Using site-directed mutagenesis and molecular dynamics, a small set of models for YjiO TM6 multimerization interface interactions were generated. This work demonstrates the utility of combining in vivo genetic tools with computational systems for understanding membrane protein structure and assembly.


Assuntos
Membrana Celular/metabolismo , Proteínas de Ligação a DNA , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Escherichia coli , Biblioteca Genômica , Proteínas de Membrana/química , Modelos Moleculares , Motivos de Aminoácidos , Sequência de Aminoácidos , Substituição de Aminoácidos , Bacteriófago lambda/imunologia , Bacteriófago lambda/fisiologia , Sequência de Bases , Sítios de Ligação , Membrana Celular/química , Clonagem Molecular/métodos , Dimerização , Escherichia coli/citologia , Escherichia coli/genética , Escherichia coli/imunologia , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Genes Bacterianos/genética , Vetores Genéticos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Dados de Sequência Molecular , Ligação Proteica , Sinais Direcionadores de Proteínas/genética , Sinais Direcionadores de Proteínas/fisiologia , Estrutura Quaternária de Proteína , Estrutura Terciária de Proteína , Subunidades Proteicas , Transporte Proteico , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteínas Repressoras/química , Proteínas Repressoras/metabolismo , Proteínas Virais , Proteínas Virais Reguladoras e Acessórias
18.
ASAIO J ; 47(5): 522-7, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11575830

RESUMO

A previous investigation by our laboratory linked cellulose acetate degradation with adverse health effects in hemodialysis patients. To establish the accumulation of degradation products with time, a Monte Carlo model of degradation kinetics was developed. The model tracks changes in a population of molecules representative of the dialyzer membrane during the degradation process. The degradation calculation is a two step process: First, the model uses a random number to select an individual polymer molecule out of the population, and then a second random number is used to identify a site on the selected molecule for the degradation reaction to occur. After the reaction calculation, the resulting degraded molecules are redistributed into the population. The course of the reaction is determined by recalculating the molecular weight averages in the changing population as the calculations proceed. The model was validated using gel permeation chromatography molecular weight results and total acetyl content measurements on dialyzers stored up to 13.3 years after manufacture. It was found that the degradation reactions can be accurately modeled as random events and that the chain scissions and deacetylation events occur at constant rates. The shelf life of these devices was estimated using the model predictions and animal test results.


Assuntos
Celulose , Celulose/análogos & derivados , Rins Artificiais , Membranas Artificiais , Celulose/efeitos adversos , Celulose/química , Estabilidade de Medicamentos , Humanos , Técnicas In Vitro , Rins Artificiais/efeitos adversos , Modelos Químicos , Peso Molecular , Método de Monte Carlo , Segurança , Fatores de Tempo
19.
J Biol Chem ; 276(47): 44078-82, 2001 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-11535607

RESUMO

Protein phosphatase-1 (PP1) plays a key role in dephosphorylation in numerous biological processes such as glycogen metabolism, cell cycle regulation, smooth muscle contraction, and protein synthesis. Microorganisms produce a variety of inhibitors of PP1, which include the microcystin class of inhibitors and okadaic acid, the latter being the major cause of diarrhetic shellfish poisoning and a powerful tumor promoter. We have determined the crystal structure of the molecular complex of okadaic acid bound to PP1 to a resolution of 1.9 A. This structure reveals that the acid binds in a hydrophobic groove adjacent to the active site of the protein and interacts with basic residues within the active site. Okadaic acid exhibits a cyclic structure, which is maintained via an intramolecular hydrogen bond. This is reminiscent of other macrocyclic protein phosphatase inhibitors. The inhibitor-bound enzyme shows very little conformational change when compared with two other PP1 structures, except in the inhibitor-sensitive beta12-beta13 loop region. The selectivity of okadaic acid for protein phosphatases-1 and -2A but not PP-2B (calcineurin) may be reassessed in light of this study.


Assuntos
Carcinógenos/química , Ácido Okadáico/química , Fosfoproteínas Fosfatases/química , Carcinógenos/farmacologia , Cristalografia por Raios X , Estrutura Molecular , Ácido Okadáico/farmacologia , Fosfoproteínas Fosfatases/antagonistas & inibidores , Proteína Fosfatase 1
20.
J Biomed Mater Res ; 53(3): 276-86, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-10813768

RESUMO

4, 4'-Methylenedianiline (MDA) is a hydrolysis degradation product that can be released from polyurethanes commonly used in medical device applications. MDA is mutagenic and carcinogenic in animals. In humans, it is hepatotoxic, a known contact and respiratory allergen, and a suspected carcinogen. A physiologically based pharmacokinetic (PBPK) model was developed to estimate the absorption, distribution, metabolism, and excretion of MDA in patients exposed to MDA leached from the potting materials of hemodialyzers. A worst-case reuse situation and a single use case were investigated. The PBPK model included five tissue compartments: liver, kidney, gastrointestinal tract, slowly perfused tissues, and richly perfused tissues. Physiological and chemical parameters of a healthy individual used in the model were obtained from the literature. The model was calibrated using previously published kinetic studies of IV administered doses of (14) C-MDA to rats. The model was validated using independent data published for MDA-exposed workers. The PBPK results indicated that dialysis patients who are exposed to MDA released from dialyzers (new or reused) could accumulate low levels of MDA and metabolites (total MDA) over time.


Assuntos
Compostos de Anilina/farmacocinética , Materiais Biocompatíveis/farmacocinética , Carcinógenos/farmacocinética , Equipamentos e Provisões/efeitos adversos , Poliuretanos/metabolismo , Animais , Humanos , Modelos Biológicos , Poliuretanos/farmacocinética , Ratos
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