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1.
J Environ Qual ; 46(1): 210-218, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28177415

RESUMO

Current understanding of the variability in soil properties and their relationship to processes and spatial patterns in forested landscapes is limited due to the scarcity of datasets providing such information. Here we present a spatially highly resolved dataset () that provides detailed information on the three-dimensional variability of biogeochemical properties in the Wüstebach catchment (western Germany), a long-term environmental observation site of the TERENO (Terrestrial Environmental Observatories) project. High-resolution soil sampling was conducted, and physical and biogeochemical soil parameters were recorded per horizon. The dataset is helpful in the analysis of the spatial heterogeneity in biogeochemical properties within soil horizons and with depth through the soil profile. In addition, it shows links between hydrological and biogeochemical properties and processes within the system. Overall, the dataset provides a high-resolution view into (re)cycling, leaching, and storage of nutrients on the catchment scale in a forested headwater catchment.


Assuntos
Conjuntos de Dados como Assunto , Florestas , Solo/química , Poluentes da Água/química , Monitoramento Ambiental , Alemanha , Poluentes da Água/análise
2.
J Environ Qual ; 46(6): 1510-1518, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-29293837

RESUMO

Quantification and evaluation of elemental distribution in forested ecosystems are key requirements to understand element fluxes and their relationship with hydrological and biogeochemical processes in the system. However, datasets supporting such a study on the catchment scale are still limited. Here we provide a dataset comprising spatially highly resolved distributions of 39 elements in soil profiles of a small forested headwater catchment in western Germany () to gain a holistic picture of the state and fluxes of elements in the catchment. The elements include both plant nutrients and other metals and metalloids that were predominately derived from lithospheric or anthropogenic inputs, thereby allowing us to not only capture the nutrient status of the catchment but to also estimate the functional development of the ecosystem. Soil samples were collected at high lateral resolution (≤60 m), and element concentrations were determined vertically for four soil horizons (L/Of, Oh, A, B). From this, a three-dimensional view of the distribution of these elements could be established with high spatial resolution on the catchment scale in a temperate natural forested ecosystem. The dataset can be combined with other datasets and studies of the TERENO (Terrestrial Environmental Observatories) Data Discovery Portal () to reveal elemental fluxes, establish relations between elements and other soil properties, and/or as input for modeling elemental cycling in temperate forested ecosystems.


Assuntos
Ecossistema , Monitoramento Ambiental , Metaloides , Alemanha , Metais , Solo/química
3.
J Environ Qual ; 39(4): 1451-66, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20830932

RESUMO

In Germany, zero-tension lysimeters are used as part of the registration requirements in case pesticides pose a potential threat to contaminate the groundwater. However, the water regime and the method of pesticide sampling differ between the lysimeters and the field. We monitored the transport of the two herbicides ethidimuron [1-(5- ethylsulfonyl-1,3,4-thiadiazol-2-yl)-1,3-dimethylurea] (ETD) and methabenzthiazuron [1-benzothiazol-2-yl-1,3-dimethyl-urea] (MBT) and their main metabolite, accompanied with bromide as conservative tracer, in zero-tension lysimeters filled with undisturbed soil and in the field. The herbicides were applied as a short pulse to the bare soil surface. Herbicide concentrations were analyzed in the drainage water of the 1.2-m-deep lysimeters and from soil cores taken from the field during six campaigns. Soil coring in the field emphasized matrix flow and allowed us to estimate the field-based dissipation and sorption parameters. Based on mass recovery calculations, the field fate half-life was 870 d for ETD compared with 389 d for its main metabolite. The initially fast field-based dissipation of MBT with a half-life value of approximately 1 mo was followed by a much slower dissipation. The retardation factor was estimated from the concentration profiles by inversely solving the convection-dispersion equation and yielded 18.2 +/- 1.3 for ETD and 36.9 +/- 17.5 for MBT. For the lysimeters, a leaching period of 2 1/2 yr was too short to monitor bulk herbicide mass through the soil matrix. Only 1.7% of the applied EDT and 1.4% of the applied MBT were sampled in the drainage water at 1.2 m depth. Despite contrasting sorption and dissipation properties, both herbicides appeared fast and at the same time in the drainage water, hinting at preferential flow phenomena. Compared with field fate of herbicides measured by soil coring, zero-potential lysimeters emphasize the transport of small amounts of herbicides triggered by preferential flow events.


Assuntos
Benzotiazóis/química , Herbicidas/química , Compostos de Metilureia/química , Poluentes do Solo/química , Solo/análise , Monitoramento Ambiental , Alemanha , Temperatura
4.
Anal Bioanal Chem ; 391(3): 1029-38, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18414833

RESUMO

An efficient extraction of sulfadiazine residues from soils is difficult, as sulfadiazine is known to form quickly sequestering residues. The objective of this study was to optimize an exhaustive extraction for aged residues of sulfadiazine and its two major metabolites, N-acetylsulfadiazine and 4-hydroxysulfadiazine, from soil. For this purpose two representative used agricultural soils (Luvisol, Cambisol) were blended with manure derived from [(14)C]sulfadiazine-treated pigs and incubated at 10 degrees C in the laboratory. After different extraction tests with various solvent mixtures (two- to four-component mixtures with water, methanol, acetonitrile, acetone, and/or ethyl acetate), different pH values (pH 4 and 9), and extraction temperatures (up to 200 degrees C), soil extracts were measured by liquid scintillation counting and liquid chromatography coupled to tandem mass spectrometry. With respect to sulfadiazine yields, stability of soil extracts, and the amount of coextracted matrix, a microwave extraction of soil (15 min, 150 degrees C) using acetonitrile/water 1:4 (v/v) is the method of choice for the exhaustive extraction of aged sulfadiazine residues from soils.


Assuntos
Micro-Ondas , Solo/análise , Extração em Fase Sólida/métodos , Sulfadiazina/análise , Sulfadiazina/efeitos da radiação , Espectrometria de Massas em Tandem/métodos , Cromatografia Líquida de Alta Pressão/métodos , Reprodutibilidade dos Testes
5.
J Environ Qual ; 36(6): 1735-48, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17965376

RESUMO

The knowledge of the composition and fluxes of vadose zone water is essential for a wide range of scientific and practical fields, including water-use management, pesticide registration, fate of xenobiotics, monitoring of disposal from mining and industries, nutrient management of agricultural and forest ecosystems, ecology, and environmental protection. Nowadays, water and solute flow can be monitored using either in situ methods or minimally invasive geophysical measurements. In situ information, however, is necessary to interpret most geophysical data sets and to determine the chemical composition of seepage water. Therefore, we present a comprehensive review of in situ soil water extraction methods to monitor solute concentration, solute transport, and to calculate mass balances in natural soils. We distinguished six different sampling devices: porous cups, porous plates, capillary wicks, pan lysimeters, resin boxes, and lysimeters. For each of the six sampling devices we discuss the basic principles, the advantages and disadvantages, and limits of data acquisition. We also give decision guidance for the selection of the appropriate sampling system. The choice of material is addressed in terms of potential contamination, filtering, and sorption of the target substances. The information provided in this review will support scientists and professionals in optimizing their experimental set-up for meeting their specific goals.


Assuntos
Solo , Água , Coloides , Projetos de Pesquisa , Sensibilidade e Especificidade , Soluções
6.
Eur Urol ; 40(3): 241-51, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11684838

RESUMO

The androgen receptor (AR) is the key regulatory element of androgen signaling in the cell. It mediates action of androgens and is therefore essential for growth, function and differentiation of the human male urogenital tract. Genetic alterations in the AR gene may cause impaired development resulting in androgen insensitivity syndromes (AIS) or in neurodegenerative diseases like Kennedy syndrome. Besides the crucial role in the process of virilization during embryogenesis and puberty, the AR also plays an important role in the adult man as the intracellular mediator of androgen action. Androgen withdrawal and/or AR blockade is the main choice of treatment of nonorgan-confined prostate cancer. Unfortunately, this treatment is only palliative and a majority of these tumors recur and progress to an androgen-independent and therapy-resistant stage. Recent findings gave new insight into the molecular structure and function of the AR and improved our understanding about prostate cancer progression, consequently resulting in the development of novel treatments. It has become evident that the AR is a nuclear transcription factor that can be activated ligand-dependently by androgens as well as ligand-independently by other hormones and various growth factors, respectively. Moreover, it was shown that the interaction of the AR with other proteins of the intracellular signal transduction cascade may promote prostate tumor growth. This review will summarize the most important findings about the AR and the androgen signaling pathway to improve the understanding of prostate diseases and novel treatment strategies that may be useful in the clinic.


Assuntos
Neoplasias da Próstata/genética , Receptores Androgênicos/genética , Síndrome de Resistência a Andrógenos/genética , Humanos , Masculino , Mutação Puntual , Neoplasias da Próstata/terapia , Sequências Repetidas Terminais
7.
Prostate ; 45(2): 124-31, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-11027411

RESUMO

BACKGROUND: Androgen receptor (AR) transcriptional activity is modulated by cofactor proteins. They act as costimulators, corepressors, or bridging proteins, and a disbalanced expression may contribute to the altered activity of the AR in advanced prostate cancer. We investigated the expression of a series of steroid receptor cofactors in prostate cancer cell lines, including several LNCaP sublines, and in prostate stromal cells. METHODS: Expression of cofactors was analyzed by means of RT-PCR in PC-3, Du-145, LNCaP, three sublines of LNCaP established after long-term androgen deprivation, and two strains of primary prostate stroma cells. Expression in LNCaP and LNCaP-abl cells (which represented an advanced tumor cell) was analyzed employing semiquantitative RT-PCR. RESULTS: Ten of the 12 cofactors tested were expressed in all cells analyzed (AIB1, ARA54, ARA70, CBP, cyclin D1, Her2/neu/erbB2, BAG-1/M/L, SRC-1, SMRT, and TIF2). Only ARA55 and FHL2 mRNAs were not detected in all cells. ARA55 mRNA was absent in LNCaP cells, LNCaP sublines, and DU-145 cells; FHL2 was not expressed in LNCaP cells and its derivatives. The expression pattern was identical in LNCaP cells, and the long-term androgen ablated LNCaP sublines. Moreover, comparison of expression levels in LNCaP and LNCaP-abl cells revealed a slight reduction in LNCaP-abl cells but no gross differences. CONCLUSIONS: Prostatic cells express a great number of steroid receptor cofactors. AR activity thus seems to be modulated in a very complex way in prostate cells.


Assuntos
Neoplasias da Próstata , Receptores Androgênicos/metabolismo , Células Tumorais Cultivadas , Adenocarcinoma , Células Cultivadas , Progressão da Doença , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Modelos Biológicos , Neoplasias da Próstata/metabolismo , Células Estromais/citologia , Células Estromais/metabolismo
8.
Cancer Gene Ther ; 7(7): 997-1007, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10917202

RESUMO

Currently available methods for treatment of human prostatic carcinoma aim to inactivate the androgen receptor (AR) by androgen deprivation or blockade with anti-androgens. Failure of endocrine therapy and tumor progression is characterized by androgen-independent growth despite high levels of AR expression in metastatic disease. We inhibited AR expression in LNCaP prostate tumor cells by using antisense AR oligodeoxynucleotides (ODNs) and explored whether antisense AR treatment would be conceivable as a therapy for advanced prostate cancer. Among the various AR antisense ODNs tested, a 15-base ODN targeting the CAG repeats encoding the poly-glutamine region of the AR (as750/15) was found to be most effective. Treatment of LNCaP cells with as750/15 reduced AR expression to approximately 2% within 24 hours compared with mock-treated controls. AR down-regulation resulted in significant cell growth inhibition, strongly reduced secretion of the androgen-regulated prostate-specific antigen, reduction of epidermal growth factor receptor expression, and an increase in apoptotic cells. Mis-sense and mismatched control ODNs had no or only slight effects. Antisense inhibition was also very efficient in LNCaP-abl cells, a subline established after long-term androgen ablation of LNCaP cells, resulting in inhibition of AR expression and cell proliferation that was similar to that seen for parental LNCaP cells. This study shows that inhibition of AR expression by antisense AR ODNs may be a promising new approach for treatment of advanced human prostate cancer.


Assuntos
Oligodesoxirribonucleotídeos Antissenso/uso terapêutico , Neoplasias da Próstata/terapia , Receptores Androgênicos/genética , Apoptose , Divisão Celular , Primers do DNA/química , Regulação para Baixo , Ensaio de Imunoadsorção Enzimática , Receptores ErbB/metabolismo , Terapia Genética , Humanos , Immunoblotting , Masculino , Antígeno Prostático Específico/análise , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , RNA Mensageiro/análise , Receptores Androgênicos/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Tempo , Células Tumorais Cultivadas
9.
Eur Urol ; 35(5-6): 413-9, 1999.
Artigo em Inglês | MEDLINE | ID: mdl-10325498

RESUMO

Androgens are pivotal regulators of prostate cell growth, differentiation and function, and their actions are believed to be involved in prostate cancer development. The androgen-signaling pathway in the prostate gland is therefore one of the possible sites of intervention in prostate cancer prevention efforts. The central element of androgen signaling in the cell is the androgen receptor (AR), a member of the superfamily of nuclear receptors. Binding of androgen to its ligand-binding domain transforms the receptor to an active transcription factor that regulates gene expression by interacting with specific regulatory elements in the promoters of genes. In addition to this genomic action, the AR also interacts with other signaling pathways through protein-protein interaction, for example with AP-1 or Ets transcription factors. It is not only the action of androgenic hormones, but also the interactions with growth factor and protein kinase A-signaling pathways that can induce activation of AR. Moreover, these ligand-independent activators act synergistically together with low concentrations of androgens. The effects of long-term androgen deprivation on androgen signaling have been investigated in the LNCaP cell culture system. Long-term culture in a steroid-free medium results in a subline showing a hyperreactive AR characterized by increased AR expression and enhanced AR transcriptional activity in an environment with low levels of androgen hormones. It is not yet clear if similar changes also occur in normal or premalignant prostate epithelial cells and are thus relevant for prevention trials which interfere with androgen hormone signaling.


Assuntos
Antineoplásicos/administração & dosagem , Neoplasias da Próstata/prevenção & controle , Receptores Androgênicos/efeitos dos fármacos , Biotransformação/efeitos dos fármacos , Ensaios Clínicos como Assunto , Humanos , Masculino , Neoplasias da Próstata/fisiopatologia , Receptores Androgênicos/metabolismo , Sensibilidade e Especificidade , Células Tumorais Cultivadas
10.
Cancer Res ; 59(1): 227-33, 1999 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-9892211

RESUMO

Epidermal growth factor (EGF) and insulin-like growth factor I (IGF-I) are potent mitogens that regulate proliferation of prostate cancer cells via autocrine and paracrine loops and promote tumor metastasis. They exert their action through binding to the corresponding cell surface receptors that initiate an intracellular phosphorylation cascade, leading to the activation of mitogen-activated protein kinases (MAPKs), which recruit transcription factors. We have studied the effects of EGF, IGF-I, and the protein kinase A (PKA) activator forskolin on the activation of p42/ extracellular signal-regulated kinase (ERK)2, which is a key kinase in mediation of growth factor-induced mitogenesis in prostate cancer cells. The activity of p42/ERK2 was determined by immune complex kinase assays and by immunoblotting using a phospho p44/p42 MAPK-specific antibody. EGF, IGF-I, and forskolin-induced PKA activity stimulate intracellular signaling pathways converging at the level of p42/ERK2. In the androgen-insensitive DU145 cell line, there is a constitutive basal p42/ ERK2 activity that is not present in androgen-sensitive LNCaP cells. Constitutive p42/ERK2 activity is abrogated by blockade of the EGF receptor. Hence, it is obviously caused by an autocrine loop involving this receptor. The effects of EGF on p42/ERK2 are potentiated by forskolin in both cell lines. The blockade of PKA by the specific inhibitor H89 attenuates this synergism. This finding is in contrast to those obtained in several other systems studied thus far, in which PKA activators inhibited MAPKs. p42/ERK2 in DU145 cells is highly responsive to IGF-I stimulation, whereas no effect of IGF-I on p42/ERK2 can be measured in LNCaP cells. Moreover, our results demonstrate that selective blockade of the EGF receptor in prostate cancer cells does not only inhibit the action of EGF, but also IGF-I-induced activation of the MAPK pathway and the interaction with the PKA pathway. In conclusion, these findings offer new possibilities for a therapeutical intervention in prostate cancer by targeting signaling pathways of growth factors and PKA.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Fator de Crescimento Epidérmico/farmacologia , Receptores ErbB/metabolismo , Fator de Crescimento Insulin-Like I/farmacologia , Neoplasias da Próstata/metabolismo , Transdução de Sinais/efeitos dos fármacos , Ativação Enzimática/efeitos dos fármacos , Receptores ErbB/antagonistas & inibidores , Humanos , Masculino , Células Tumorais Cultivadas
11.
Cancer Res ; 58(20): 4640-5, 1998 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-9788616

RESUMO

Interleukin-6 (IL-6) levels are frequently elevated in sera of patients with metastatic prostate cancer. IL-6 receptors are expressed in prostate cancer cell lines, as well as in benign prostate hyperplasia and prostate cancer tissue specimens. The androgen receptor (AR) is a key transcription factor that is present in all stages of prostate carcinoma, even in therapy-refractory tumors. In an attempt to investigate possible cross-talk between IL-6 and androgen signal transduction cascades, we tested the effects of this cytokine on AR transcriptional activity. The regulation of AR activity by IL-6 was studied in DU-145 cells, which were cotransfected with the androgen-responsive reporter plasmid ARE2TATACAT and the AR expression vector pSG5AR. We show that IL-6 up-regulates AR activity in a ligand-independent manner, as well as synergistically, with very low doses of the synthetic androgen methyltrienolone (5-10 pM). Therefore, AR activation by IL-6 may be operative in prostate cancer patients who have decreased androgen levels because of androgen ablation therapy. The maximal induction of reporter gene activity by IL-6 alone (50 ng/ml) was 67% of that stimulated by 1 nM of methyltrienolone. The nonsteroidal antiandrogen bicalutamide (Casodex) nearly completely inhibited AR activation by IL-6. IL-6 effects on AR activity were also abolished or greatly reduced by inhibitors of protein kinase A and C and mitogen-activated protein kinase pathways. In concordance with the results obtained in DU-145 cells, IL-6 induced AR-regulated prostate-specific antigen mRNA and protein in LNCaP cells. Stimulation of prostate-specific antigen protein secretion by IL-6 was antagonized by bicalutamide and inhibitors of protein kinase A and mitogen-activated protein kinase signaling pathways. Taken together, our data show for the first time that IL-6 is a nonsteroidal activator of the AR and that this activation is implicated in the regulation of prostate-specific proteins. Keeping in mind that IL-6, its receptor, and the AR are expressed in prostate cancers, cross-talk between IL-6 and AR signaling pathways may have clinical significance.


Assuntos
Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Interleucina-6/farmacologia , Antígeno Prostático Específico/genética , Neoplasias da Próstata/metabolismo , Receptores Androgênicos/efeitos dos fármacos , Regulação para Baixo , Humanos , Masculino , Antígeno Prostático Específico/biossíntese , Inibidores de Proteínas Quinases , Transfecção , Células Tumorais Cultivadas
12.
Int Surg ; 77(4): 235-7, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1478801

RESUMO

A randomized controlled trial was conducted on 142 adult male and female patients for primary inguinal hernias by the Shouldice or the Bassini-Kirschner surgical technique. Follow-up after one year revealed 7 recurrences out of 72 patients having had Bassini-Kirschner's operation and three recurrences out of 70 patients having had Shouldice's operation (p = 0.326, NS). Six patients died during the follow-up period and two were lost to the study. At two years follow-up examination nine recurrences out of 63 patients having had Bassini-Kirschner's operation and seven recurrences out of 65 patients having had Shouldice's operation were found (p = 0.792, NS). Both operations gave the same results when performed by either a consultant surgeon or a surgeon in training. The complication rate was high but similar for both techniques (18%). Although surgical literature abounds with excellent low recurrence rates using the Shouldice surgical technique, we were unable to reproduce these results. This might be due to lack of experience.


Assuntos
Hérnia Inguinal/cirurgia , Adolescente , Adulto , Idoso , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Recidiva , Procedimentos Cirúrgicos Operatórios/métodos
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