Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 342
Filtrar
1.
Nature ; 604(7906): 457-462, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35444321

RESUMO

Gate-model quantum computers promise to solve currently intractable computational problems if they can be operated at scale with long coherence times and high-fidelity logic. Neutral-atom hyperfine qubits provide inherent scalability owing to their identical characteristics, long coherence times and ability to be trapped in dense, multidimensional arrays1. Combined with the strong entangling interactions provided by Rydberg states2-4, all the necessary characteristics for quantum computation are available. Here we demonstrate several quantum algorithms on a programmable gate-model neutral-atom quantum computer in an architecture based on individual addressing of single atoms with tightly focused optical beams scanned across a two-dimensional array of qubits. Preparation of entangled Greenberger-Horne-Zeilinger (GHZ) states5 with up to six qubits, quantum phase estimation for a chemistry problem6 and the quantum approximate optimization algorithm (QAOA)7 for the maximum cut (MaxCut) graph problem are demonstrated. These results highlight the emergent capability of neutral-atom qubit arrays for universal, programmable quantum computation, as well as preparation of non-classical states of use for quantum-enhanced sensing.

2.
Urologe A ; 59(3): 318-325, 2020 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-31541269

RESUMO

BACKGROUND: Technical advancement and availability of high-throughput analysis has advanced molecular subtyping of most cancers. Thus, new possibilities for precision oncology have emerged. AIM: Therefore, we aimed to collect data regarding availability and use of next generation sequencing (NGS) for urothelial cancer within the uropathology working group of the German Society of Pathology. METHODS: We collected data by questionnaires and additionally asked for sequencing results of bladder cancers in the participating institutions. RESULTS: A total of 13 university-affiliated institutes of pathology took part in the survey. All university institutes offer NGS-based molecular panel diagnostics and provide panels covering between 15 and 170 genes. Altogether, only 20 bladder cancers were sequenced in routine diagnostics and for 10 cancers potential targeted treatment options were available. DISCUSSION: So far, despite availability of NGS diagnostics at university institutes of pathology, only few bladder cancer samples have been sequenced. Based on current data from the molecular subtyping of bladder cancers, we recommend a step-by-step protocol with basic immunohistochemistry analysis and subsequent subtype-dependent analyses, e.g., alterations of the fibroblast growth factor receptors (FGFR) or comprehensive gene panel analyses.


Assuntos
Sequenciamento de Nucleotídeos em Larga Escala , Medicina de Precisão , Humanos , Mutação , Patologia Molecular , Inquéritos e Questionários , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/patologia
3.
Pathologe ; 39(Suppl 2): 193-198, 2018 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-30377787

RESUMO

BACKGROUND: Use of liquid biopsy for minimal invasive follow-up diagnostics of non-small-cell lung carcinomas (NSCLCs). OBJECTIVES: Systematic search for new putative blood-based hypermethylation biomarkers to discriminate NSCLC patients from patients without a malign disease. METHODS: Quantitative analysis of gene promoter DNA methylation of potential biomarkers from cfDNA (plasma) with pyrosequencing. RESULTS: cfDNA hypermethylation in plasma confirmed significant higher methylation frequencies of the candidate gene CFTR of the NSCLC patients compared to the combined control groups and to NSCLC patients after curative therapy of primary NSCLC (post-NSCLC). ROC-analysis of the best discriminatory CpGs of the CFTR promotor (CpG1-2-4) revealed a sensitivity of 52% in NSCLC patients and a specificity of 90% in the post-NSCLC group (AUC: 0.69; p < 0.05). CONCLUSIONS: Promotor hypermethylation of the potential biomarker CFTR shows a discriminatory potential for differentiation of NSCLC patients to patients without a malign disease and should further be investigated.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Metilação de DNA , Humanos , Biópsia Líquida , Regiões Promotoras Genéticas
4.
Pathologe ; 39(4): 308-312, 2018 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-29876651

RESUMO

BACKGROUND: Over the last 15 years, an estimated 3000 large centralized biobanks have been established worldwide, making important contributions to the further development of precision medicine. In many cases, these biobanks are affiliated with pathological institutes or work closely with them. OBJECTIVE: In which translational research projects, and during which phases in the development of new drugs are human bioprobes being used and can their use be easily traced in the literature? METHODS: PubMed, Internet research, and information from the German Biobank Alliance and the European initiative BBMRI-ERIC. RESULTS: High-quality biosamples from centralized biobanks are increasingly used in clinical research and development projects. Success stories, where bioprobes have contributed to the further development of precision medicine, are shown in this paper using among others the example of RET gene fusion discovery in lung cancer. Interestingly enough, many key publications in the field of precision medicine do not contain exact references to the biobanks involved. CONCLUSIONS: The importance of centralized biobanks in translational research and clinical development is constantly increasing. However, in order to ensure the acceptance and visibility of biobanks, their participation in success stories of biomedical progress must be systematically documented and published.


Assuntos
Bancos de Espécimes Biológicos , Pesquisa Biomédica , Academias e Institutos , Humanos , Medicina de Precisão , Pesquisa Translacional Biomédica
6.
Chem Commun (Camb) ; 54(8): 892-895, 2018 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-29242872

RESUMO

A series of copper complexes bearing new 6-substituted tris(2-pyridylmethyl)amine ligands (LR) appended with NH(p-R-C6H4) groups (R = H, CF3, OMe) were prepared. These ligands are electronically tunable (ΔE1/2 = 160 mV) and CuI(LR)+ complexes react with oxygen to form hydrogen bonded (trans-1,2-peroxo)dicopper species.

7.
Clin Radiol ; 72(8): 693.e9-693.e13, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28388969

RESUMO

AIM: To assess the value of computed tomography (CT) in the diagnosis of symptomatic sacroiliac (SI) joint degeneration. MATERIALS AND METHODS: CT images from 123 patients with clinically diagnosed SI joint pain were compared to age- and gender-matched controls without chronic back pain or previous back surgery. Degeneration was graded assessing joint space narrowing, osteophytes, subchondral sclerosis, cysts, and vacuum phenomena. RESULTS: The mean total score for the patients was 9.6 and for the controls 9.7 (p=0.77). A subgroup analysis of the mean score for the SI joints that were subjected to surgery was 4.3, compared to 4.8 in the conservatively treated SI joints in the patient group (p=0.23) and 4.8 for all SI joints in the control group (p=0.25). For patients with unilateral left-sided pain (n=40), the mean score for the left side was 5.2 and for the right side 4.9 (p=0.49). For patients with right-sided pain (n=41), the mean score for the right side was 4.8 and the left side 4.7 (p=0.55). CONCLUSION: The prevalence of SI joint degeneration on CT is equal in symptomatic and non-symptomatic individuals. This study indicates that the value of CT is limited, but further studies are needed to establish if CT has a place in diagnosing SI joint degeneration.


Assuntos
Artropatias/diagnóstico por imagem , Articulação Sacroilíaca , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto Jovem
8.
Pathologe ; 36(6): 572-8, 2015 Nov.
Artigo em Alemão | MEDLINE | ID: mdl-26395890

RESUMO

Molecular biological analysis of nucleic acids in blood or other bodily fluids (i.e. liquid biopsy analyses) may supplement the pathologists' diagnostic armamentarium in a reasonable way-particularly in cancer precision medicine. Within the field of oncology, liquid biopsy can potentially be used to monitor tumor burden in the blood and to early detect emerging resistance in the course of targeted cancer therapies. An already approved application of liquid biopsy is the detection of epidermal growth factor receptor (EGFR) driver mutations in blood samples of lung cancer patients in those cases where no tissue biopsy is available. However, there is still currently considerable insecurity associated with blood-based DNA analytic methods that must be solved before liquid biopsy can be implemented for broader routine application in the diagnosis of cancer. In this article, the current state of development of liquid biopsy in molecular diagnostics from a pathology point of view is presented.


Assuntos
Biópsia/métodos , Sistema Livre de Células/patologia , Análise Citogenética/métodos , DNA de Neoplasias/análise , Neoplasias/patologia , Patologia Molecular/métodos , Medicina de Precisão , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Humanos , Pulmão/patologia , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Neoplasias/tratamento farmacológico , Neoplasias/genética
11.
Urologe A ; 52(7): 976-81, 2013 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-23831986

RESUMO

Targeted therapies and biomarker validation are key drivers in the advancement of personalized oncology which is a growing topic in all clinical areas. Compared with other professions, such as pulmonology and gynecology, development in urology has so far been retarded but has recently gained increasing momentum. A basis for this is the currently growing and in future accelerated application of new knowledge derived from molecular biology in the field of uropathology. The rapid gain of knowledge is driven by a whole new class of analytical methods, such as massively parallel sequencing (deep sequencing or next generation sequencing), which enables analysis of virtually a new universe of potential biomarkers. This article describes the emerging paradigm shift in molecular pathological diagnostics of urological tumors using the example of prostate cancer.


Assuntos
Técnicas de Diagnóstico Urológico/tendências , Testes Genéticos/tendências , Patologia Molecular/tendências , Medicina de Precisão/tendências , Neoplasias Urogenitais/diagnóstico , Neoplasias Urogenitais/genética , Previsões , Humanos
12.
Reprod Biomed Online ; 26(3): 231-9, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23337421

RESUMO

Much has been written about the ethics of sex selection. This article thoroughly explores the ethical arguments put forth in the literature both for and against non-medical sex selection using sperm sorting. While most of these arguments come from philosophers, feminist scholars, social scientists and members of the healthcare community, they are often echoed in empirical studies that have explored community values. This review is timely because the first efficacious method for sex selection via sperm sorting, MicroSort, is currently in clinical trials and moving closer to FDA approval for marketing in the USA. While the clinical trials are currently focused on the use of MicroSort to avoid X-linked genetic diseases, MicroSort can also be used to satisfy parental preferences.


Assuntos
Citometria de Fluxo/ética , Pré-Seleção do Sexo/ética , Espermatozoides/citologia , Ensaios Clínicos como Assunto , Feminino , Citometria de Fluxo/métodos , Doenças Genéticas Ligadas ao Cromossomo X/prevenção & controle , Direitos Humanos , Humanos , Masculino , Técnicas de Reprodução Assistida , Razão de Masculinidade , Valores Sociais
13.
Toxicol Lett ; 214(3): 268-78, 2012 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-22982764

RESUMO

Trichothecenes are a large family of chemically related mycotoxins. Deoxynivalenol (DON), T-2 and HT-2 toxins belong to this family and are produced by various species of Fusarium. The H295R steroidogenesis assay, regulation of steroidogenic gene expression and reporter gene assays (RGAs) for the detection of androgen, estrogen, progestagen and glucocorticoid (ant)agonist responses, have been used to assess the endocrine disrupting activity of DON, T-2 and HT-2 toxins. H295R cells were used as a model for steroidogenesis and gene expression studies and exposed with either DON (0.1-1000ng/ml), T-2 toxin (0.0005-5ng/ml) or HT-2 toxin (0.005-50ng/ml) for 48h. We observed a reduction in hormone levels in media of exposed cells following radioimmunoassay. Cell viability was determined by four colorimetric assays and we observed reduced cell viability with increasing toxin concentrations partly explaining the significant reduction in hormone levels at the highest toxin concentration of all three trichothecenes. Thirteen of the 16 steroidogenic genes analyzed by quantitative real time PCR (RT-qPCR) were significantly regulated (P<0.05) by DON (100ng/ml), T-2 toxin (0.5ng/ml) and HT-2 toxin (5ng/ml) compared to the control, with reference genes (B2M, ATP5B and ACTB). Whereas HMGR and CYP19 were down-regulated, CYP1A1 and CYP21 were up-regulated by all three trichothecenes. DON further up-regulated CYP17, HSD3B2, CYP11B2 and CYP11B1 and down-regulated NR5A1. T-2 toxin caused down-regulation of NR0B1 and NR5A1 whereas HT-2 toxin induced up-regulation of EPHX and HSD17B1 and down-regulation of CYP11A and CYP17. The expressions of MC2R, StAR and HSD17B4 genes were not significantly affected by any of the trichothecenes in the present study. Although the results indicate that there is no evidence to suggest that DON, T-2 and HT-2 toxins directly interact with the steroid hormone receptors to cause endocrine disruption, the present findings indicate that exposure to DON, T-2 toxin and HT-2 toxin have effects on cell viability, steroidogenesis and alteration in gene expression indicating their potential as endocrine disruptors.


Assuntos
Carcinoma Adrenocortical/tratamento farmacológico , Disruptores Endócrinos/toxicidade , Antagonistas de Hormônios/toxicidade , Hormônios/metabolismo , Receptores de Esteroides/efeitos dos fármacos , Tricotecenos/toxicidade , Carcinoma Adrenocortical/metabolismo , Carcinoma Adrenocortical/patologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Meios de Cultivo Condicionados/química , Meios de Cultivo Condicionados/metabolismo , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Genes Reporter , Humanos , Luciferases/genética , Luciferases/metabolismo , Glândulas Mamárias Humanas/citologia , Glândulas Mamárias Humanas/metabolismo , Receptores de Esteroides/genética , Receptores de Esteroides/metabolismo , Toxina T-2/análogos & derivados , Toxina T-2/toxicidade , Transfecção
14.
Aliment Pharmacol Ther ; 36(7): 619-26, 2012 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-22908905

RESUMO

BACKGROUND: Vaptans may correct hyponatraemia and mobilise ascites through an increased excretion of water. The effect on clinical outcomes is debated. AIM: To determine the effects of vaptans (tolvaptan, satavaptan and lixivaptan) on patients with cirrhosis and hyponatraemia or ascites. METHODS: Systematic review of randomised controlled trials. The primary outcome measure was mortality. Electronic and manual searches were combined (April 2012). Data were extracted from published reports, online information from the Food and Drug Administration website or obtained through correspondence with authors and pharmaceutical companies. The primary meta-analyses were performed using random effects models due to an expected clinical diversity. RESULTS: Twelve trials with a total of 2266 patients were included. Randomisation was adequate in all trials. Eight trials were double-blind. Random effects meta-analyses found no clear differences between vaptans and control groups regarding mortality (RR = 1.06, 95% CI = 0.90-1.26, I(2) = 0%), variceal bleeding, hepatic encephalopathy, spontaneous bacterial peritonitis, hepatorenal syndrome, or renal failure. Vaptans increased serum sodium levels (WMD = 1.8 mmol/L, 95% CI = 0.79-2.96) and lead to reductions in weight and the time to the first paracentesis. Vaptans increased the risk of adverse events (RR = 3.97, 95% CI = 1.78-8.83), including an excessive urine volume (RR = 9.96, 95% CI = 1.38-71.68). CONCLUSIONS: Vaptans have a small beneficial effect on hyponatraemia and ascites, but do not affect mortality, complications to cirrhosis or renal failure. The data do not support the routine use of vaptans in cirrhosis.


Assuntos
Antagonistas dos Receptores de Hormônios Antidiuréticos , Ascite/tratamento farmacológico , Benzamidas/uso terapêutico , Benzazepinas/uso terapêutico , Hiponatremia/tratamento farmacológico , Cirrose Hepática/tratamento farmacológico , Morfolinas/uso terapêutico , Pirróis/uso terapêutico , Compostos de Espiro/uso terapêutico , Benzamidas/efeitos adversos , Benzazepinas/efeitos adversos , Humanos , Hiponatremia/sangue , Morfolinas/efeitos adversos , Pirróis/efeitos adversos , Ensaios Clínicos Controlados Aleatórios como Assunto , Receptores de Vasopressinas/administração & dosagem , Sódio/sangue , Compostos de Espiro/efeitos adversos , Tolvaptan , Resultado do Tratamento
15.
Artigo em Inglês | MEDLINE | ID: mdl-22891979

RESUMO

The accumulation of phycotoxins in bivalve mussels associated with mussels feeding on toxic phytoplankton is a well-known phenomenon in Norway. Regular monitoring for 25 years has revealed that accumulation of Diarrhetic Shellfish poisoning (DSP) toxins in mussels is the main phycotoxin problem along the Norwegian coast. The aim of this study was to evaluate possible trends over time of Dinophysis spp. and DSP as well as possible correlation between abundance of Dinophysis spp. and toxin accumulation in mussels, as based on intensive and regular monitoring at the southern coast of Norway at Flødevigen Bay. The main source organism causing a risk of DSP in Norway is Dinophysis acuta. However, it cannot be excluded that other Dinophysis spp., e.g. D. acuminata and D. norvegica, may contribute to the total accumulation of toxins. The variability in the occurrence of these species is high at both short- and long-term; between days and between years. There are, however, some important overall patterns in the occurrence of the species during the last decades. Dinophysis acuminata and D. norvegica have mainly been abundant from March to December, whereas D. acuta has typically occurred in late summer and autumn (August-December). For all three species we have observed a narrowing of the peak season since 2002 at the same time as they have become less abundant. Coincident with these changes, the problem of the accumulation of DSP toxins in mussels along the southern coast of Norway has declined significantly, but it is still mainly restricted to the autumn. Why the cell concentration of Dinophysis spp. has declined after 2002 is not obvious, but this has occurred in a period with relatively high summer temperatures. The relatively simultaneous changes in physical, chemical and biological factors of the pelagic ecosystem along the southern coast of Norway indicate that complicated ecological interactions may be involved.


Assuntos
Mudança Climática , Dinoflagellida/crescimento & desenvolvimento , Toxinas Marinhas/análise , Mytilus edulis/química , Fitoplâncton/crescimento & desenvolvimento , Água do Mar , Frutos do Mar/análise , Animais , Dinoflagellida/isolamento & purificação , Dinoflagellida/metabolismo , Ecossistema , Monitoramento Ambiental , Contaminação de Alimentos , Inspeção de Alimentos , Proliferação Nociva de Algas , Humanos , Toxinas Marinhas/biossíntese , Mytilus edulis/crescimento & desenvolvimento , Mar do Norte , Noruega , Fitoplâncton/isolamento & purificação , Fitoplâncton/metabolismo , Reprodutibilidade dos Testes , Estações do Ano , Intoxicação por Frutos do Mar/prevenção & controle , Especificidade da Espécie
16.
J Evol Biol ; 25(6): 1066-76, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22587843

RESUMO

Chronic stress often affects growth and development negatively, and these effects are often mediated via glucocorticoid hormones, which elevate during stress. We investigated latitudinal variation in corticosterone (CORT) response to chronic predator stress in Rana temporaria tadpoles along a 1500-km latitudinal cline in Sweden tadpoles, in a laboratory experiment. We hypothesized that more time-constrained high-latitude populations have evolved a lower CORT response to chronic stress to maintain higher growth under stressful conditions. Southern tadpoles had higher CORT content in response to predators after 1 day of exposure, whereas there was no increase in CORT in the northern populations. Two weeks later, there were no predator-induced CORT elevations. Artificially elevated CORT levels strongly decreased growth, development and survival in both northern and southern tadpoles. We suggest that the lower CORT response in high-latitude populations can be connected with avoidance of CORT-mediated reduction in growth and development, but also discuss other possible explanations.


Assuntos
Corticosterona/metabolismo , Geografia , Comportamento Predatório , Rana temporaria/fisiologia , Estresse Fisiológico , Animais , Tamanho Corporal , Corticosterona/análise , Meio Ambiente , Insetos/fisiologia , Larva/crescimento & desenvolvimento , Larva/metabolismo , Larva/fisiologia , Densidade Demográfica , Radioimunoensaio , Rana temporaria/crescimento & desenvolvimento , Rana temporaria/metabolismo , Especificidade da Espécie , Suécia
17.
Oncogene ; 31(16): 2101-14, 2012 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-21909132

RESUMO

Tumorigenesis and tumor progression are associated with dysfunction of the nuclear transport machinery at the level of import and export receptors (karyopherins). Recent studies have shown that the nuclear import factor karyopherin-α2 (KPNA2) is a novel prognostic marker for poor prognosis in human breast cancer. Based on the well-defined hallmarks of cancer progression, we performed a detailed in vitro characterization of the phenotypic effects caused by KPNA2 overexpression and KPNA2 silencing in benign and malignant human breast cells. KPNA2 overexpression clearly increased proliferation of MCF7 tumor cells and further led to a reduction of cell-matrix adhesion in benign MCF10A cells, whereas cell migration was significantly increased (P<0.0001) in both tumor models. Remarkably, these individual effects of KPNA2 overexpression on proliferation, cell-matrix adhesion and migration resulted in an increased colony spreading of benign MCF10A breast cells and malignant MCF7 tumor cells (P<0.001), which is a hallmark of cancer progression. Conversely, RNA interference-mediated KPNA2 silencing caused a complete inhibition of MCF7 tumor cell proliferation and migration (P<0.0001). In addition, in these experiments apoptosis was increased (P<0.05) and formation of tumor cell colonies was reduced (P<0.01). Thus, KPNA2 overexpression provoked increased aggressiveness of malignant MCF7 breast tumor cells and induced a shift in benign MCF10A breast cells toward a malignant breast cancer phenotype. In conclusion, we demonstrate for the first time in experimental tumor models that forced KPNA2 expression drives malignant features relevant for breast cancer progression, while its silencing is required for the remission of those progressive phenotypes. This study gives clear evidence that KPNA2 acts as a novel oncogenic factor in human breast cancer, in vitro.


Assuntos
Neoplasias da Mama/genética , Movimento Celular , alfa Carioferinas/fisiologia , Neoplasias da Mama/metabolismo , Adesão Celular , Linhagem Celular Tumoral , Proliferação de Células , Feminino , Humanos , Fenótipo , Interferência de RNA , Regulação para Cima
18.
Toxicol Lett ; 206(2): 210-7, 2011 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-21803136

RESUMO

The mycotoxin zearalenone (ZEN) is a secondary metabolite of fungi which is produced by certain species of the genus Fusarium and can occur in cereals and other plant products. Reporter gene assays incorporating natural steroid receptors and the H295R steroidogenesis assay have been implemented to assess the endocrine disrupting activity of ZEN and its metabolites α-zearalenol (α-ZOL) and ß-zearalenol (ß-ZOL). α-ZOL exhibited the strongest estrogenic potency (EC(50) 0.022±0.001 nM), slightly less potent than 17-ß estradiol (EC(50) 0.015±0.002 nM). ZEN was ~70 times less potent than α-ZOL and twice as potent as ß-ZOL. Binding of progesterone to the progestagen receptor was shown to be synergistically increased in the presence of ZEN, α-ZOL or ß-ZOL. ZEN, α-ZOL or ß-ZOL increased production of progesterone, estradiol, testosterone and cortisol hormones in the H295R steroidogenesis assay, with peak productions at 10 µM. At 100 µM, cell viability decreased and levels of hormones were significantly reduced except for progesterone. ß-ZOL increased estradiol concentrations more than α-ZOL or ZEN, with a maximum effect at 10 µM, with ß-ZOL (562±59 pg/ml)>α-ZOL (494±60 pg/ml)>ZEN (375±43 pg/ml). The results indicate that ZEN and its metabolites can act as potential endocrine disruptors at the level of nuclear receptor signalling and by altering hormone production.


Assuntos
Disruptores Endócrinos/toxicidade , Hormônios Esteroides Gonadais/metabolismo , Hidrocortisona/metabolismo , Receptores de Esteroides/metabolismo , Transdução de Sinais/efeitos dos fármacos , Zearalenona/toxicidade , Zeranol/análogos & derivados , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Disruptores Endócrinos/química , Disruptores Endócrinos/metabolismo , Estrogênios não Esteroides/química , Estrogênios não Esteroides/metabolismo , Estrogênios não Esteroides/toxicidade , Genes Reporter/efeitos dos fármacos , Humanos , Concentração Inibidora 50 , Isomerismo , Concentração Osmolar , Regiões Promotoras Genéticas/efeitos dos fármacos , Receptores de Esteroides/agonistas , Receptores de Esteroides/antagonistas & inibidores , Receptores de Esteroides/genética , Transcrição Gênica/efeitos dos fármacos , Zearalenona/metabolismo , Zeranol/química , Zeranol/toxicidade
19.
Theriogenology ; 76(6): 1058-69, 2011 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-21719084

RESUMO

Breed differences in steroidogenic activity between primary Leydig cells derived from neonatal purebred Duroc and Norwegian Landrace boars were investigated in vitro. Concentrations of testosterone, estradiol, androstenone, cortisol and progesterone produced into the medium were determined. To explore underlying mechanisms the cellular expression of a suite of genes relevant in steroidogenesis was measured using reverse transcription and quantitative PCR (RT-qPCR). Basal steroid concentrations indicated a larger production capacity for steroids in unstimulated Duroc cells. Stimulation of the cells with LH increased steroid hormone secretion significantly in both breeds in a dose dependent manner. Testosterone and androstenone concentrations increased approximately 50- and 15-fold, respectively, whereas concentrations of estradiol, cortisol and progesterone increased to a lesser extent. At levels of maximal LH stimulation, absolute steroid concentrations were higher in Duroc. However, the relative increase in hormone concentrations was significantly lower in Duroc cells for estradiol, progesterone and cortisol when compared to basal levels. LH exposure was associated with a general up-regulation of mRNA levels for steroidogenic genes, stronger in Duroc than in Norwegian Landrace. This was in agreement with the higher absolute concentrations of steroid hormones measured in culture medium from the LH-stimulated Duroc Leydig cells, but did not concur with the fact that the relative increase in hormone production was lower in Duroc than in Norwegian Landrace Leydig cells for some hormones. It was concluded that breed differences in steroid hormone concentrations and gene expression between Norwegian Landrace and Duroc are complex and cannot be explained by a simple mechanism of action.


Assuntos
Hormônios Esteroides Gonadais/metabolismo , Células Intersticiais do Testículo/metabolismo , Suínos , Androsterona/metabolismo , Animais , Meios de Cultura , Estradiol/metabolismo , Expressão Gênica/efeitos dos fármacos , Hidrocortisona/metabolismo , Células Intersticiais do Testículo/efeitos dos fármacos , Hormônio Luteinizante/farmacologia , Masculino , Progesterona , Testosterona/metabolismo
20.
Food Chem Toxicol ; 49(9): 2328-35, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21722693

RESUMO

Crude cod liver oil and liver oil supplements are consumed as a source of vitamin A, D and polyunsaturated fatty acids; during winter and early pregnancy. Crude cod liver oil however constitutes a considerable source of persistent organic pollutants (POPs). This paper aimed at characterizing and quantifying the influence of POP mixtures extracted from three different steps in the cod liver oil industrial process on hormone production and the expression of steroidogenesis-related genes in H295R cells. Exposure to extracts from crude cod liver oil and from its industrial waste increased progesterone (P4), cortisol (Cort), testosterone (T) and estradiol (E2) production; and among others, the expression of MC2R, CYP11B1 and HSD3B2 genes. Observed effects after exposure to pharmaceutical cod liver oil extract were considerably lower. The type of effects on gene expression and hormone production were similar to those induced by forskolin and PCBs, the latter being the major contaminants within the extracts. Additional research is required to further unveil the mechanisms behind the observed steroidogenic effects and to assess whether the potential risk might outweigh the potential benefits of crude and processed cod liver oil consumption.


Assuntos
Óleo de Fígado de Bacalhau/química , Esteroides/biossíntese , Poluentes Químicos da Água/farmacologia , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Cromatografia Gasosa-Espectrometria de Massas , Reação em Cadeia da Polimerase em Tempo Real , Poluentes Químicos da Água/isolamento & purificação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA