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Resistant and refractory cytomegalovirus (CMV) viremia can limit the provision of chemotherapy due to myelosuppression and end-organ dysfunction. Few therapies are available for children with clinically significant CMV viremia. We successfully used maribavir for a 4-year-old patient with lymphoma to complete his chemotherapy course. Resistance to maribavir did result after many months of therapy.
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Infecções por Citomegalovirus , Diclororribofuranosilbenzimidazol , Neoplasias , Ribonucleosídeos , Pré-Escolar , Humanos , Antivirais/uso terapêutico , Benzimidazóis/uso terapêutico , Infecções por Citomegalovirus/tratamento farmacológico , Diclororribofuranosilbenzimidazol/análogos & derivados , Neoplasias/tratamento farmacológico , Ribonucleosídeos/uso terapêutico , Viremia/tratamento farmacológicoRESUMO
PURPOSE OF REVIEW: Congenital lower urinary tract obstruction (LUTO) is a rare group of conditions characterized by high perinatal morbidity and mortality if associated with oligohydramnios or anhydramnios in early pregnancy. Although foetal intervention has the potential to improve perinatal survival in a select group of foetuses with LUTO, the actual selection of those candidates most likely to benefit from intervention remains challenging. RECENT FINDINGS: Foetuses with LUTO who are potential candidates for prenatal intervention should undergo detailed multidisciplinary evaluation to ensure proper assessment and counselling. Using a combination of multiple ultrasound-based renal parameters, including measurement of foetal bladder volumes before and after vesicocentesis and kidney size and morphology, combined with repeated foetal urine biochemistry may allow for better selection than any single test. SUMMARY: Foetal intervention should be offered to women carrying a foetus with LUTO only after appropriate evaluation and counselling. A combined approach utilizing ultrasound and biochemical measurements of foetal renal function appears best. Research focusing on the development of more accurate markers is needed.
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Doenças Fetais , Oligo-Hidrâmnio , Feminino , Doenças Fetais/diagnóstico por imagem , Doenças Fetais/terapia , Humanos , Rim/diagnóstico por imagem , Oligo-Hidrâmnio/diagnóstico por imagem , Oligo-Hidrâmnio/terapia , Gravidez , Ultrassonografia , Ultrassonografia Pré-NatalRESUMO
OBJECTIVES: To determine the accuracy of ultrasound estimation of fetal weight among fetuses with gastroschisis and how the diagnosis of fetal growth restriction (FGR) affects the timing of delivery. METHODS: This was a retrospective cohort study including all fetuses with a diagnosis of gastroschisis at our institution from November 2012 through October 2017. We excluded multiple gestations, pregnancies with major structural or chromosomal abnormalities, and those for which prenatal and postnatal follow-up were unavailable. Performance characteristics of ultrasound to predict being small for gestational age (SGA) were calculated for the first and last ultrasound estimations of fetal weight. RESULTS: Our cohort included 75 cases of gastroschisis. At the initial ultrasound estimation, 15 of 58 (25.9%) fetuses met criteria for FGR; 48 of 70 (68.6%) met criteria at the time of the last ultrasound estimation (median, 34.7 weeks). Cesarean delivery was performed for 37 of 75 (49.3%), with FGR and concern for fetal distress as the indication for delivery in 17 of 37 (45.9%). Only 6 of 17 (35.3%) of the neonates born by cesarean delivery for an indication of FGR and fetal distress were SGA. The initial ultrasound designation of FGR corresponded to SGA at birth in 8 of 15 (53.3%), whereas the last ultrasound estimation corresponded to SGA in 17 of 48 (35.4%). The initial ultrasound estimation agreed with the last ultrasound estimation before delivery with the diagnosis of FGR in 13 of 15 (86.7%). CONCLUSIONS: Ultrasound in the third trimester was sensitive but had a low positive predictive value and low accuracy for the diagnosis of SGA at birth for fetuses with gastroschisis. A large proportion of fetuses were born by cesarean delivery with indications related to FGR or fetal concerns.
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Gastrosquise , Peso ao Nascer , Feminino , Retardo do Crescimento Fetal/diagnóstico por imagem , Feto , Gastrosquise/diagnóstico por imagem , Idade Gestacional , Humanos , Recém-Nascido , Recém-Nascido Pequeno para a Idade Gestacional , Gravidez , Estudos Retrospectivos , Ultrassonografia Pré-NatalRESUMO
The ability of tumors to escape from immune destruction is attributed to the protein-protein interaction between programmed cell death protein 1 (PD1) and programmed cell death ligand 1 (PDL1) proteins expressed by immune T cells and cancer cells, respectively. Therefore, pharmacological inhibition of the PD1-PDL1 interaction presents an important therapeutic target against a variety of tumors expressing PDL1 on their cell surface. Recently, five antibodies have been approved and several are in clinical trials against the PD1-PDL1 protein-protein interaction target. In contrast, there are very few reports of small-molecule inhibitors of PD1-PDL1 interaction, and most of them have relatively modest or weak inhibition activities, emphasizing the difficulty in designing small-molecule inhibitors against this challenging target. Therefore, we focused our attention on macrocycles that are known to exhibit target activity comparable to large macromolecules despite having molecular weights closer to small, drug-like molecules. In this context, our present study led to the identification of several macrocyclic compounds from the ansamycin antibiotics class to be inhibitors of PD1-PDL1 interaction. Importantly, one of these macrocyclic antibiotics, Rifabutin, showed an IC50 value of ca. 25 µM. This is remarkable considering it has a relatively low molecular weight and still is capable of inhibiting PD1-PDL1 protein-protein interaction whose binding interface spans over ca. 1970 Å2. Thus, these macrocycles may serve as guiding points for discovery and optimization of more potent, selective small-molecule inhibitors of PD1-PDL1 interaction, one of the most promising therapeutic targets against cancer.
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Antibacterianos/química , Antineoplásicos/química , Antígeno B7-H1/antagonistas & inibidores , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Rifabutina/análogos & derivados , Rifabutina/química , Antígeno B7-H1/química , Descoberta de Drogas , Humanos , Modelos Moleculares , Receptor de Morte Celular Programada 1/química , Ligação ProteicaAssuntos
Terapias Fetais/métodos , Anormalidades Congênitas/terapia , Feminino , Doenças Fetais/diagnóstico , Doenças Fetais/terapia , Terapias Fetais/ética , Terapias Fetais/tendências , Fetoscopia/métodos , Humanos , Recém-Nascido , Manejo da Dor/métodos , Assistência Perinatal/métodos , Gravidez , Ultrassonografia de Intervenção , Ultrassonografia Pré-NatalRESUMO
BACKGROUND: Inflammatory myofibroblastic tumor (IMFT) is an uncommon neoplasm in children. METHODS: Retrospective review from 1993 to 2014 of patients ≤18years of age with a histopathologic diagnosis of IMFT treated at two tertiary centers. RESULTS: Thirty-two patients were diagnosed with IMFT. Mean (±SD) age was 9.3±5.7years at diagnosis. Tumor location was variable: abdomen/pelvis (28%), head/neck region (22%), intrathoracic (22%), genitourinary (9%), bowel (6%) liver (6%), and musculoskeletal (6%). Median follow-up was 2.6±4.6years, with 3 recurrences and 2 deaths, which occurred only after recurrence. Positive microscopic margin after resection was associated with recurrence, compared to those that had a negative margin (40% vs. 0%, p=0.04). Recurrence was associated with increased mortality (67% vs 0%, p=0.01). Time from first symptoms to resection was shorter in those with recurrence (25.8±22 vs. 179±275days, p=0.01) and in nonsurvivors (44.0±8.0 vs. 194.3±53.4days, p=0.02). Adjuvant chemotherapy, not including steroid monotherapy, either given before or after resection, was administered more often to nonsurvivors (100% vs 4%, p=0.009), and use of corticosteroids was also higher in the nonsurvivors (100% vs. 15%, p=0.04). CONCLUSIONS: IMFT is a rare pediatric neoplasm with variable locations. Complete excision is critical for cure. Proposed guidelines for diagnosis, treatment and surveillance of theses tumors in children are reported.
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Granuloma de Células Plasmáticas , Adolescente , Antineoplásicos/uso terapêutico , Quimioterapia Adjuvante , Criança , Pré-Escolar , Feminino , Seguimentos , Granuloma de Células Plasmáticas/diagnóstico , Granuloma de Células Plasmáticas/tratamento farmacológico , Granuloma de Células Plasmáticas/mortalidade , Granuloma de Células Plasmáticas/cirurgia , Humanos , Lactente , Recém-Nascido , Masculino , Estudos Retrospectivos , Resultado do TratamentoRESUMO
Hereditary tyrosinemia type I (HT1) is caused by deficiency in fumarylacetoacetate hydrolase (FAH), an enzyme that catalyzes the last step of tyrosine metabolism. The most severe form of the disease presents acutely during infancy, and is characterized by severe liver involvement, most commonly resulting in death if untreated. Generation of FAH(+/-) pigs was previously accomplished by adeno-associated virus-mediated gene knockout in fibroblasts and somatic cell nuclear transfer. Subsequently, these animals were outbred and crossed to produce the first FAH(-/-) pigs. FAH-deficiency produced a lethal defect in utero that was corrected by administration of 2-(2-nitro-4-trifluoromethylbenzoyl)-1,3 cyclohexanedione (NTBC) throughout pregnancy. Animals on NTBC were phenotypically normal at birth; however, the animals were euthanized approximately four weeks after withdrawal of NTBC due to clinical decline and physical examination findings of severe liver injury and encephalopathy consistent with acute liver failure. Biochemical and histological analyses, characterized by diffuse and severe hepatocellular damage, confirmed the diagnosis of severe liver injury. FAH(-/-) pigs provide the first genetically engineered large animal model of a metabolic liver disorder. Future applications of FAH(-/-) pigs include discovery research as a large animal model of HT1 and spontaneous acute liver failure, and preclinical testing of the efficacy of liver cell therapies, including transplantation of hepatocytes, liver stem cells, and pluripotent stem cell-derived hepatocytes.
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Hidrolases/deficiência , Hepatopatias/enzimologia , Tirosinemias/enzimologia , Animais , Modelos Animais de Doenças , Feminino , Técnicas de Inativação de Genes , Genótipo , Hepatopatias/metabolismo , Masculino , Gravidez , SuínosRESUMO
INTRODUCTION: Internal hernias through the foramen of Winslow are rare events and constitute 8% of internal hernias but only 0.1% of all abdominal hernias. PRESENTATION OF CASE: A 62-year-old man presented with upper abdominal pain, distention and vomiting, and was shown on CT scan to have the right colon and cecum herniating into the lesser sac through the foramen of Winslow. This diagnosis was confirmed at laparotomy as well as a midgut volvulus and right hemicolectomy was performed because of ischemic changes of the cecum. DISCUSSION: Six developmental abnormalities may result in internal herniation of bowel contents in the abdomen: (i) abnormal retroperitoneal fixation of the mesentery resulting in anomalous positioning of the intestine; (ii) incomplete mesenteric surfaces with the presence of abnormal opening through which the intestine herniates, (iii) abnormally large internal foramina or fossae (e.g. foramen of Winslow); (iv) abnormally long small-bowel mesentery; (v) an elongated right hepatic lobe thought to guide bowel into the foramen of Winslow, and (vi) persistence of the ascending mesocolon allowing marked mobility of the right colon. CONCLUSION: We believe that hypermobile cecum was responsible for the internal herniation through the foramen of Winslow and that this served as the lead point allowing for the midgut volvulus. There is no consensus on the surgical management of internal hernias through the Foramen of Winslow when the herniated contents are grossly viable. The literature in this regard is scarce and surgical decision making is based on surgeon preference and the viability of the herniated intraabdominal contents.
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In utero cell transplantation (IUCT) can lead to the postnatal engraftment of human cells in the xenogeneic recipient. Most reports of IUCT have involved hematopoietic stem cells. It is unknown whether human hepatocytes used for IUCT in fetal pigs will lead to the engraftment of these same cells in the postnatal environment. In this study, fetal pigs received direct liver injections of 1 × 10(7) human hepatocytes in utero and were delivered by cesarean section at term. The piglets received a second direct liver injection of 5 × 10(7) human hepatocytes 1 week after birth. The serum was analyzed for human albumin 2, 4, and 6 weeks after engraftment. Piglet livers were harvested 6 weeks after transplantation and were examined by immunohistochemistry, polymerase chain reaction, and fluorescence in situ hybridization for human-specific sequences. Piglets undergoing IUCT with human hepatocytes that were postnatally engrafted with human hepatocytes showed significant levels of human albumin production in their serum at all postengraftment time points. Human albumin gene expression, the presence of human hepatocytes, and the presence of human beta-2 microglobulin were all confirmed 6 weeks after engraftment. IUCT in fetal pigs with human hepatocytes early in gestation allowed the engraftment of human hepatocytes, which remained viable and functional for weeks after transplantation. IUCT followed by postnatal engraftment may provide a future means for large-scale expansion of human hepatocytes in genetically engineered pigs.
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Hepatócitos/transplante , Fígado/cirurgia , Animais , Animais Recém-Nascidos , Biomarcadores/sangue , Sobrevivência Celular , Feminino , Regulação da Expressão Gênica , Idade Gestacional , Hepatócitos/imunologia , Hepatócitos/metabolismo , Humanos , Imuno-Histoquímica , Hibridização in Situ Fluorescente , Injeções , Fígado/diagnóstico por imagem , Fígado/embriologia , Fígado/imunologia , Fígado/metabolismo , Gravidez , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Albumina Sérica/genética , Albumina Sérica/metabolismo , Albumina Sérica Humana , Suínos , Fatores de Tempo , Transplante Heterólogo , Ultrassonografia de Intervenção , Microglobulina beta-2/genética , Microglobulina beta-2/metabolismoRESUMO
Long-term culture of hepatocyte spheroids with high ammonia clearance is valuable for therapeutic applications, especially the bioartificial liver. However, the optimal conditions are not well studied. We hypothesized that liver urea cycle enzymes can be induced by high protein diet and maintain on a higher expression level in rat hepatocyte spheroids by serum-free medium (SFM) culture and coculture with mesenchymal stromal cells (MSCs). Rats were feed normal protein diet (NPD) or high protein diet (HPD) for 7 days before liver digestion and isolation of hepatocytes. Hepatocyte spheroids were formed and maintained in a rocked suspension culture with or without MSCs in SFM or 10% serum-containing medium (SCM). Spheroid viability, kinetics of spheroid formation, hepatic functions, gene expression, and biochemical activities of rat hepatocyte spheroids were tested over 14 days of culture. We observed that urea cycle enzymes of hepatocyte spheroids can be induced by high protein diet. SFM and MSCs enhanced ammonia clearance and ureagenesis and stabilized integrity of hepatocyte spheroids compared to control conditions over 14 days. Hepatocytes from high protein diet-fed rats formed spheroids and maintained a high level of ammonia detoxification for over 14 days in a novel SFM. Hepatic functionality and spheroid integrity were further stabilized by coculture of hepatocytes with MSCs in the spheroid microenvironment. These findings have direct application to development of the spheroid reservoir bioartificial liver.
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Hepatócitos/citologia , Fígado Artificial , Células-Tronco Mesenquimais/citologia , Animais , Meios de Cultura Livres de Soro , Modelos Animais de Doenças , Hepatócitos/enzimologia , Hepatócitos/metabolismo , Masculino , Células-Tronco Mesenquimais/metabolismo , Ratos , Ratos Sprague-Dawley , Esferoides CelularesRESUMO
BACKGROUND: Significant morbidity associated with acute liver failure (ALF) is from the systemic inflammatory response syndrome (SIRS). Toll-like receptor 4 (TLR4) has been shown to play an integral role in the modulation of SIRS. However, little is known about the mechanistic role of TLR4 in ALF. Also, no cell type has been identified as the key mediator of the TLR4 pathway in ALF. This study examines the role of TLR4 and Kupffer cells (KCs) in the development of the SIRS following acetaminophen (APAP)-induced ALF. MATERIALS AND METHODS: Five groups of mice were established: untreated wild-type, E5564-treated (a TLR4 antagonist), gadolinium chloride -treated (KC-depleted), clodronate-treated (KC-depleted), and TLR4-mutant. Following APAP administration, 72-h survival, biochemical and histologic liver injury, extent of lung injury and edema, and proinflammatory gene expression were studied. Additionally, TLR4 expression was determined in livers of wild-type and KC-depleted mice. RESULTS: Following APAP administration, wild-type, TLR4-mutant, E5564-treated, and KC-depleted mice had significant liver injury. However, wild-type mice had markedly worse survival compared with the other four treatment groups. TLR4-mutant, E5564-treated, and KC-depleted mice had less lung inflammation and edema than wild-type mice. Selected proinflammatory gene expression (interleukin 1ß, interleukin 6, tumor necrosis factor) in TLR4-mutant, E5564-treated, and KC-depleted mice was significantly lower compared with wild-type mice after acute liver injury. CONCLUSION: This study demonstrates that survival in APAP-induced ALF potentially correlates with the level of proinflammatory gene expression. This study points to a link between TLR4 and KCs in the APAP model of ALF and, more importantly, demonstrates benefits of TLR4 antagonism in ALF.
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Acetaminofen/toxicidade , Analgésicos não Narcóticos/toxicidade , Células de Kupffer/efeitos dos fármacos , Falência Hepática Aguda/induzido quimicamente , Receptor 4 Toll-Like/fisiologia , Animais , Células HEK293 , Humanos , Lipopolissacarídeos/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C3H , Síndrome de Resposta Inflamatória Sistêmica/etiologia , Receptor 4 Toll-Like/agonistas , Receptor 4 Toll-Like/análiseRESUMO
Cell therapies, which include bioartificial liver support and hepatocyte transplantation, have emerged as potential treatments for a variety of liver diseases. Acute liver failure, acute-on-chronic liver failure, and inherited metabolic liver diseases are examples of liver diseases that have been successfully treated with cell therapies at centers around the world. Cell therapies also have the potential to be widely applied to other liver diseases, including noninherited liver diseases and liver cancer, and to improve the success of liver transplantation. Here we briefly summarize current concepts of cell therapy for liver diseases.
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Terapia Baseada em Transplante de Células e Tecidos/métodos , Hepatopatias/terapia , Animais , Modelos Animais de Doenças , Hepatócitos/transplante , Humanos , Fígado Artificial , Transplante de Células-Tronco/métodos , SuínosRESUMO
UNLABELLED: Hereditary tyrosinemia type I (HT1) results in hepatic failure, cirrhosis, and hepatocellular carcinoma (HCC) early in childhood and is caused by a deficiency in the enzyme fumarylacetoacetate hydrolase (FAH). In a novel approach we used the chimeric adeno-associated virus DJ serotype (AAV-DJ) and homologous recombination to target and disrupt the porcine Fah gene. AAV-DJ is an artificial chimeric AAV vector containing hybrid capsid sequences from three naturally occurring serotypes (AAV2, 8, and 9). The AAV-DJ vector was used to deliver the knockout construct to fetal pig fibroblasts with an average knockout targeting frequency of 5.4%. Targeted Fah-null heterozygote fibroblasts were used as nuclear donors for somatic cell nuclear transfer (SCNT) to porcine oocytes and multiple viable Fah-null heterozygote pigs were generated. Fah-null heterozygotes were phenotypically normal, but had decreased Fah transcriptional and enzymatic activity compared to wildtype animals. CONCLUSION: This study is the first to use a recombinant chimeric AAV vector to knockout a gene in porcine fibroblasts for the purpose of SCNT. In using the AAV-DJ vector we observed targeting frequencies that were higher than previously reported with other naturally occurring serotypes. We expect that the subsequent generation of FAH-null homozygote pigs will serve as a significant advancement for translational research in the areas of metabolic liver disease, cirrhosis, and HCC.
Assuntos
Dependovirus/genética , Técnicas de Inativação de Genes/métodos , Hidrolases/genética , Hidrolases/metabolismo , Técnicas de Transferência Nuclear , Suínos/genética , Animais , Animais Recém-Nascidos , Southern Blotting , Quimera , Feto/citologia , Fibroblastos/citologia , Fibroblastos/fisiologia , Vetores Genéticos , Heterozigoto , Recombinação Homóloga/genética , Recombinação Homóloga/fisiologia , Modelos Animais , Oócitos/citologia , Oócitos/fisiologia , Reação em Cadeia da Polimerase , Sensibilidade e Especificidade , Tirosinemias/genética , Tirosinemias/fisiopatologiaRESUMO
BACKGROUND: Hepatic resection of metastatic carcinoid cancer can prolong survival and control symptomatic endocrinopathy. Decompensated carcinoid heart disease (CHD) can develop in some patients with metastatic carcinoid cancers, which can preclude operation for resectable hepatic metastases. We hypothesized that outcomes after hepatic resection for patients with the carcinoid syndrome after valve replacement for CHD would be similar to carcinoid patients without CHD. STUDY DESIGN: We compared the survival and symptom control after hepatic resection for patients undergoing valve replacement for CHD to carcinoid patients without CHD matched for age, sex, and extent of hepatectomy. RESULTS: Fourteen patients with earlier valve replacement for CHD were compared with 28 carcinoid patients without CHD. All patients had hepatic resection for metastatic carcinoid disease and carcinoid syndrome. Mean age, sex distribution, and extent of hepatectomy (major hepatectomy, 78%) was similar between groups. Mean interval from valve replacement to hepatectomy was 101 days. There was no operative mortality. Major operative morbidity, inclusive of operative blood loss and cardiorespiratory events, occurred in 28.5% and 14.2% for CHD and non-CHD groups, respectively (p = 0.16). Symptom-free survival for CHD and non-CHD groups was 69% and 81% at 1 year (p = 0.22) and 61% and 44% (p = 0.17) at 5 years, respectively. Octreotide-free survival after hepatectomy 69% and 84% (p = 0.15) at 1 year and 62% and 52% (p = 0.29) 5 years, respectively. Overall survival CHD and non-CHD groups 100% at 1 year and 100% and 70% (p = 0.002) 5 years. CONCLUSIONS: Valve replacement for severe CHD is safe and hepatic resection is associated with similar outcomes as patients without CHD undergoing hepatic resection for carcinoid syndrome. Identifying resectable hepatic metastases from carcinoids in patients with severe CHD should prompt valve replacement and interval hepatic resection.
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Doença Cardíaca Carcinoide/patologia , Doença Cardíaca Carcinoide/cirurgia , Implante de Prótese de Valva Cardíaca , Hepatectomia , Neoplasias Hepáticas/secundário , Neoplasias Hepáticas/cirurgia , Adulto , Idoso , Doença Cardíaca Carcinoide/mortalidade , Estudos de Casos e Controles , Estudos de Coortes , Feminino , Humanos , Neoplasias Hepáticas/mortalidade , Masculino , Pessoa de Meia-Idade , Taxa de Sobrevida , Resultado do TratamentoRESUMO
Hepatocyte spheroids have been proposed for drug metabolism studies and in bioartificial liver devices. However, the optimal conditions required to meet the aerobic demands of mitochondria-rich hepatocyte spheroids is not well studied. We hypothesized that an optimal concentration of oxygen could be identified and that the health of hepatocyte spheroids might be further improved by antioxidant therapy. Rat hepatocyte spheroids were maintained in suspension culture for 7 days under a mixture of 5% CO(2) plus O(2):N(2) to achieve fractional oxygen contents of 6%(C1), 21%(C2), 58%(C3), and 95%(C4). Spheroid health was assessed under each condition by vital staining, TEM, oxygen consumption, and mitochondrial counts. Hepatocyte differentiation was assessed by expression of 10 liver-related genes (HNF4a, HNF6, Cyp1A1, albumin, Nags, Cps1, Otc, Ass, Asl, Arg1). Functional markers (albumin and urea) were measured. The influence of oxygen tension and antioxidant treatment on the production of reactive oxygen species (ROS) was assessed by confocal microscopy. We observed that the hepatocyte spheroids were healthiest under normal atmospheric (C2) conditions with antioxidants ascorbic acid and L-carnitine. Cell death and reduced functionality of hepatocyte spheroids correlated with the formation of ROS. Normal atmospheric conditions provided the optimal oxygen tension for suspension culture of hepatocyte spheroids. The formation and deleterious effects of ROS were further reduced by adding antioxidants to the culture medium. These findings have direct application to development of the spheroid reservoir bioartificial liver and the use of hepatocyte spheroids in drug metabolism studies.
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Antioxidantes/farmacologia , Pressão Atmosférica , Hepatócitos/efeitos dos fármacos , Oxigênio/metabolismo , Esferoides Celulares/efeitos dos fármacos , Animais , Ácido Ascórbico/metabolismo , Carnitina/metabolismo , Técnicas de Cultura de Células , Sobrevivência Celular , Células Cultivadas , Hepatócitos/fisiologia , Masculino , Mitocôndrias Hepáticas/metabolismo , Consumo de Oxigênio , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Esferoides Celulares/fisiologiaRESUMO
PURPOSE: Gemcitabine, a pyrimidine nucleoside, is approved for the treatment of non-small cell lung cancer, pancreatic carcinoma, and breast cancer. Chemotherapy regimens are determined experimentally with static tissue culture systems, animal models, and in Phase I clinical trials. The aim of this study was to assess for gemcitabine-induced cell death following infusion of drug under clinically-relevant conditions of infusion rate and drug exposure in an in vitro bioreactor system. METHODS: To estimate an appropriate harvest time for cells from the bioreactor after drug treatment, we estimated the temporal relationship between gemcitabine treatment for 1 h and cell death at a later time point with monolayer growth assays (i.e., static culture). Afterward, 5.3 mg gemcitabine was infused over 0.5 h in the bioreactor, followed by mono-exponential decay, simulating patient concentration-time profiles (n = 4). Controls were run with drug-free media (n = 4). Cells were harvested from the bioreactor at a later time point and assessed for cell death by flow cytometry. RESULTS: According to monolayer growth assay results, cytotoxicity became more apparent with increasing time. The E Max for cells 48 h after treatment was 50% and after 144 h, 93% (P = 0.022; t test), while flow cytometry showed complete DNA degradation by 120 h. Gemcitabine was infused in the bioreactor. The gemcitabine area under the concentration-time curve (AUC) was 56.4 microM h and the maximum concentration was 87.5 +/- 2.65 microM. Flow cytometry results were as follows: the G1 fraction decreased from 65.1 +/- 4.91 to 28.6 +/- 12% (P = 0.005) and subG1 increased from 14.1 +/- 5.28 to 42.6 +/- 9.78% (P = 0.004) relative to control. An increase in apoptotic cells was observed by TUNEL assay. CONCLUSIONS: The in vitro bioreactor system will be expanded to test additional cell lines, and will serve as a useful model system for assessing the role of drug pharmacokinetics in delivery of optimized anticancer treatment.
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Antimetabólitos Antineoplásicos/farmacocinética , Antimetabólitos Antineoplásicos/toxicidade , Desoxicitidina/análogos & derivados , Área Sob a Curva , Reatores Biológicos , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , DNA de Neoplasias/metabolismo , Desoxicitidina/farmacocinética , Desoxicitidina/toxicidade , Citometria de Fluxo , Humanos , Marcação In Situ das Extremidades Cortadas , Sais de Tetrazólio , Tiazóis , GencitabinaRESUMO
Five-year survival for non-small cell lung cancer is 15%. Gemcitabine is a nucleoside analogue that inhibits ribonucleotide reductase and interferes with DNA replication. In this study, we sought to compare short versus continuous infusion gemcitabine in an in vitro bioreactor system using pharmacokinetic-guided dosing. Gemcitabine was infused over either 0.5 or 2.5h to produce concentration-time profiles that mimic those measured in biological samples (i.e., patient plasma). The effects of gemcitabine on the growth and survival of H2009 cells were examined using trypan blue staining, cell cycle analysis, TUNEL assay, and clonogenic assay. Data were analyzed with two ways analysis of variance. Maximum gemcitabine (Cmax) concentrations during the short infusion were 51.2+/-10.4 microM and for the continuous, 14.8+/-2.93 microM. Steady-state concentrations during the continuous infusions were 14.9+/-2.90 microM. Gemcitabine treatment resulted in a decrease for G1 fraction relative to controls. G2/M, subG1 and TUNEL were higher following gemcitabine relative to controls. Survival was approximately 20-fold higher following the short infusion compared with the continuous infusion (p = 0.0085). In conclusion, gemcitabine infused by this novel method induced apoptosis after both the short and continuous infusions, and long-term survival was significantly diminished following continuous compared with the short infusion.
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Reatores Biológicos , Carcinoma Pulmonar de Células não Pequenas/patologia , Técnicas de Cultura de Células/instrumentação , Desoxicitidina/análogos & derivados , Neoplasias Pulmonares/patologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Desoxicitidina/metabolismo , Desoxicitidina/farmacologia , Citometria de Fluxo , Humanos , Marcação In Situ das Extremidades Cortadas , Fatores de Tempo , Ensaio Tumoral de Célula-Tronco , GencitabinaRESUMO
Triglycerides are increasingly being recognized as a risk factor for cardiovascular disease. Research efforts to identify sources of variability in triglyceride-lowering response to the lipid-lowering drug fenofibrate require quantification of the active acidic form of this PPAR-alpha agonist. Anion-exchange solid-phase extraction, in combination with reverse-phase high-performance liquid chromatography (HPLC), rapidly and accurately determines steady-state fenofibric acid serum concentrations. Chromatographic separation under isocratic conditions, with use of ultraviolet detection at 285 nm, provides clean baseline and sharp peaks for clofibric acid, 1-napthyl acetic acid (internal standards), and fenofibric acid. Commonly prescribed and over-the-counter nonsteroidal anti-inflammatory drugs (NSAIDs) were screened for assay interference, and the assay was employed to quantify fenofibric acid in more than 800 human subject specimens. Fenofibric acid analysis was found to be linear over the range of 0.5 to 40 mg/L and was validated with either internal standard. Accuracies ranged from 98.65% to 102.4%, whereas the within- and between-day precisions ranged from 1.0% to 2.2% and 2.0% to 6.2%, respectively. NSAIDs had minimal interference with the assay, which succeeded in quantifying fenofibric acid in more than 843 of 846 serum samples from human subjects, many taking a variety of coadministered medications. Anion-exchange solid-phase extraction in combination with reverse-phase HPLC accurately determines steady-state fenofibric acid serum concentrations in humans without interference from NSAIDs or commonly administered medications. This method is suitable for quantification of fenofibric acid for clinical pharmacokinetic studies in patients with dyslipidemia.
Assuntos
Fenofibrato/análogos & derivados , Hipolipemiantes/sangue , Resinas de Troca Aniônica , Anti-Inflamatórios não Esteroides/sangue , Cromatografia Líquida de Alta Pressão/métodos , Estabilidade de Medicamentos , Fenofibrato/sangue , Humanos , Sensibilidade e Especificidade , Extração em Fase Sólida/métodosRESUMO
Gemcitabine, a pyrimidine antimetabolite undergoes metabolism by plasma and liver cytidine deaminase to form the inactive compound, 2',2'-difluorodeoxyuridine (dFdU). The parent molecule is activated by intracellular phosphorylation. To evaluate the population pharmacokinetics in patients receiving gemcitabine, and to test the relation between gemcitabine infusion rate and antitumor activity in an in vitro bioreactor cell culture system, we developed and validated a sensitive and specific HPLC-UV method for gemcitabine and dFdU. Deproteinized plasma is vortexed, centrifuged, and 25 microL of the acidified extract sample is injected onto a Waters Spherisorb 4.6 mm x 250 mm, 5 microm C18 column at 40 degrees C. The mobile phase (flow rate, 1.0 mL/min) consists of 10:90 (v/v) acetonitrile-aqueous buffer (50 mM sodium phosphate and 3.0 mM octyl sulfonic acid, pH 2.9). Gemcitabine, dFdU, and the internal standard, 2'-deoxycytidine (2'dC) were detected with UV wavelength set at 267 nm. The standard curves for gemcitabine in both matrices ranged from 2 to 200 microM, and for dFdU in plasma, from 2 to 100 microM. Within-run and between-run component precision (CV%) was Assuntos
Cromatografia Líquida de Alta Pressão/métodos
, Desoxicitidina/análogos & derivados
, Floxuridina/análogos & derivados
, Reatores Biológicos
, Meios de Cultura/química
, Desoxicitidina/análise
, Desoxicitidina/sangue
, Estabilidade de Medicamentos
, Floxuridina/análise
, Floxuridina/sangue
, Humanos
, Reprodutibilidade dos Testes
, Espectrofotometria Ultravioleta
, Gencitabina