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1.
Urol Int ; 106(5): 431-439, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35144260

RESUMEN

BACKGROUND: Focal therapy (FT) is an option to treat localized prostate cancer (PCa) and preserve healthy prostate tissue in order to reduce known side effects from primary whole-gland treatment. The available FT modalities are manifold. Until now, national and international PCa guidelines have been cautious to propose recommendations regarding FT treatment since data from prospective controlled trials are lacking for most FT modalities. Moreover, none of the international guidelines provides a separate section on FT. In this purpose, we provide a synopsis of the consensus-based German S3 guidelines for a possible international use. SUMMARY: The recently published update of the German S3 guidelines, an evidence- and consensus-based guideline, provides a section on FT with recommendations for diagnostic work-up, indications, modalities, and follow-up. This section consists of 12 statements and recommendations for FT in the treatment of localized PCa. KEY MESSAGE: The German S3 guidelines on PCa are the first to incorporate recommendations for FT based on evidence and expert consensus including indication criteria for FT, pretreatment, and follow-up diagnostic pathways as well as an extended overview of FT techniques and the current supportive evidence.


Asunto(s)
Neoplasias de la Próstata , Crioterapia , Humanos , Masculino , Estudios Prospectivos , Neoplasias de la Próstata/diagnóstico , Neoplasias de la Próstata/terapia
2.
Cancer Med ; 10(19): 6807-6822, 2021 10.
Artículo en Inglés | MEDLINE | ID: mdl-34546000

RESUMEN

Rocaglates are natural compounds that have been extensively studied for their ability to inhibit translation initiation. Rocaglates represent promising drug candidates for tumor treatment due to their growth-inhibitory effects on neoplastic cells. In contrast to natural rocaglates, synthetic analogues of rocaglates have been less comprehensively characterized, but were also shown to have similar effects on the process of protein translation. Here, we demonstrate an enhanced growth-inhibitory effect of synthetic rocaglates when combined with glucose anti-metabolite 2-deoxy-D-glucose (2DG) in different cancer cell lines. Moreover, we unravel a new aspect in the mechanism of action of synthetic rocaglates involving reduction of glucose uptake mediated by downregulation or abrogation of glucose transporter GLUT-1 expression. Importantly, cells with genetically induced resistance to synthetic rocaglates showed substantially less pronounced treatment effect on glucose metabolism and did not demonstrate GLUT-1 downregulation, pointing at the crucial role of this mechanism for the anti-tumor activity of the synthetic rocaglates. Transcriptome profiling revealed glycolysis as one of the major pathways differentially regulated in sensitive and resistant cells. Analysis of synthetic rocaglate efficacy in a 3D tissue context with a co-culture of tumor and normal cells demonstrated a selective effect on tumor cells and substantiated the mechanistic observations obtained in cancer cell lines. Increased glucose uptake and metabolism is a universal feature across different tumor types. Therefore, targeting this feature by synthetic rocaglates could represent a promising direction for exploitation of rocaglates in novel anti-tumor therapies.


Asunto(s)
Benzofuranos/uso terapéutico , Transportador de Glucosa de Tipo 1/metabolismo , Glucosa/metabolismo , Neoplasias/tratamiento farmacológico , Benzofuranos/farmacología , Proliferación Celular , Humanos
3.
J Cancer Res Clin Oncol ; 147(4): 1271-1272, 2021 04.
Artículo en Inglés | MEDLINE | ID: mdl-33507360

RESUMEN

The authors of this "Letter to the Editors" express their major concern about selective and biased reporting in this paper.


Asunto(s)
Braquiterapia , Neoplasias de la Próstata , Humanos , Masculino , Prostatectomía
4.
Cell Rep ; 30(8): 2481-2488.e5, 2020 02 25.
Artículo en Inglés | MEDLINE | ID: mdl-32101697

RESUMEN

Rocaglates are a diverse family of biologically active molecules that have gained tremendous interest in recent years due to their promising activities in pre-clinical cancer studies. As a result, this family of compounds has been significantly expanded through the development of efficient synthetic schemes. However, it is unknown whether all of the members of the rocaglate family act through similar mechanisms of action. Here, we present a comprehensive study comparing the biological activities of >200 rocaglates to better understand how the presence of different chemical entities influences their biological activities. Through this, we find that most rocaglates preferentially repress the translation of mRNAs containing purine-rich 5' leaders, but certain rocaglates lack this bias in translation repression. We also uncover an aspect of rocaglate mechanism of action in which the pool of translationally active eIF4F is diminished due to the sequestration of the complex onto RNA.


Asunto(s)
Benzofuranos/farmacología , Factor 4A Eucariótico de Iniciación/genética , Factor 4F Eucariótico de Iniciación/genética , Mutación con Ganancia de Función/genética , Animales , Secuencia de Bases , Bioensayo , Células HEK293 , Humanos , Ratones , Células 3T3 NIH , Biosíntesis de Proteínas/efectos de los fármacos , ARN Mensajero/genética , ARN Mensajero/metabolismo
5.
Cell Chem Biol ; 26(11): 1586-1593.e3, 2019 11 21.
Artículo en Inglés | MEDLINE | ID: mdl-31519508

RESUMEN

Rocaglates share a common cyclopenta[b]benzofuran core that inhibits eukaryotic translation initiation by modifying the behavior of the RNA helicase, eIF4A. Working as interfacial inhibitors, rocaglates stabilize the association between eIF4A and RNA, which can lead to the formation of steric barriers that block initiating ribosomes. There is significant interest in the development and expansion of rocaglate derivatives, as several members of this family have been shown to possess potent anti-neoplastic activity in vitro and in vivo. To further our understanding of rocaglate diversity and drug design, herein we explore the RNA clamping activity of >200 unique rocaglate derivatives. Through this, we report on the identification and characterization of a potent class of synthetic rocaglates called amidino-rocaglates. These compounds are among the most potent rocaglates documented to date and, taken together, this work offers important information that will guide the future design of rocaglates with improved biological properties.


Asunto(s)
Amidinas/química , Antineoplásicos/química , Benzofuranos/química , Factor 4A Eucariótico de Iniciación/antagonistas & inhibidores , Animales , Antineoplásicos/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/uso terapéutico , Benzofuranos/metabolismo , Supervivencia Celular/efectos de los fármacos , ARN Helicasas DEAD-box/química , ARN Helicasas DEAD-box/genética , ARN Helicasas DEAD-box/metabolismo , Diseño de Fármacos , Factor 4A Eucariótico de Iniciación/genética , Factor 4A Eucariótico de Iniciación/metabolismo , Femenino , Humanos , Linfoma/tratamiento farmacológico , Linfoma/metabolismo , Linfoma/patología , Ratones , Ratones Endogámicos C57BL , Biosíntesis de Proteínas/efectos de los fármacos , ARN/química , ARN/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/aislamiento & purificación , Ribosomas/metabolismo , Relación Estructura-Actividad
6.
Food Chem Toxicol ; 123: 162-168, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30352299

RESUMEN

A series of in vitro studies were conducted to assess the genetic toxicity of jelly mushroom glycolipids from Dacryopinax spathularia (herein referred to as "AM-1"). In the bacterial reverse mutation assay (Ames test), there was no evidence of mutagenic activity in any Salmonella typhimurium strains tested or in Escherichia coli strain WP2uvrA, at dose levels up to 5000 µg/plate. In the micronucleus (MN) test using human lymphocytes, AM-1 did not show a statistically significant increase in the number of binucleated cells containing micronuclei when compared to concurrent control cultures at all time points and at any of the concentrations analyzed (up to 900 µg/ml of culture medium). No increase in mutation frequency or numbers of small and large colonies were noted for AM-1 (up to 800 µg/ml) compared to concurrent controls when tested in the mouse lymphoma thymidine kinase assay (MLA). Therefore, AM-1 was concluded to be negative in all three assays performed both in the absence and presence of Aroclor 1254- or phenobarbital/ß-naphthoflavone-induced rat liver (S9 mix) for metabolic activation. These results support the safety assessment of jelly mushroom glycolipids for potential use in food.


Asunto(s)
Basidiomycota/química , Glucolípidos/toxicidad , Mutágenos/toxicidad , Animales , Basidiomycota/metabolismo , Escherichia coli/efectos de los fármacos , Escherichia coli/genética , Glucolípidos/química , Glucolípidos/metabolismo , Humanos , Linfocitos/efectos de los fármacos , Masculino , Pruebas de Micronúcleos , Pruebas de Mutagenicidad , Mutágenos/química , Mutágenos/metabolismo , Mutación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Ratas Wistar , Salmonella typhimurium/efectos de los fármacos , Salmonella typhimurium/genética
7.
Histopathology ; 72(3): 449-459, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28851100

RESUMEN

AIMS: Programmed death ligand 1 (PD-L1) immunohistochemistry has become a mandatory diagnostic test in the treatment of lung cancer. Several research initiatives have started to harmonise the five PD-L1 immunohistochemistry assays that have been used in clinical trials. Here, we report data on interlaboratory and interassay concordance for commercial assays ('assays') and laboratory-developed tests (LDTs) at 10 German testing sites. METHODS AND RESULTS: To assess interlaboratory concordance, a tissue microarray containing 21 pulmonary carcinoma specimens was centrally prepared. Pre-cut sections were stained at 10 sites by the use of assays 28-8, 22C3, SP263, and SP142, as well as 11 LDTs. Assay performance was evaluated with a second tissue microarray containing 11 cell lines with defined PD-L1 expression. Quality control was centrally performed by manual and digital analyses. The assays yielded reproducible IHC staining patterns at all sites. In agreement with previous studies, 22C3, 28-8 and SP263 showed similar staining patterns, whereas SP142 was distinct. Among the LDTs, six of 11 protocols showed staining patterns similar to those of assays 22C3 and 28-8. Interlaboratory concordance of tumour cell scoring by use of a six-step system was moderate (Light's κ = 0.43-0.69), whereas the clinically approved cut-offs of ≥1% and ≥50% showed substantial concordance (κ = 0.73-0.89). Immune cell scoring by the use of SP142 yielded moderate concordance (κ = 0.42). CONCLUSIONS: The data confirm the previously described staining patterns of the assays, and show that they can be reproducibly employed at different sites. LDTs with staining results similar to those of the assays are implementable, but have to be carefully validated.


Asunto(s)
Antígeno B7-H1/análisis , Biomarcadores de Tumor/análisis , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Inmunohistoquímica/normas , Neoplasias Pulmonares/diagnóstico , Humanos , Reproducibilidad de los Resultados
8.
Anal Bioanal Chem ; 410(3): 999-1006, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28905087

RESUMEN

A new approach is presented for cell lysate identification which uses SERS-active silver nanoparticles and a droplet-based microfluidic chip. Eighty-nanoliter droplets are generated by injecting silver nanoparticles, KCl as aggregation agent, and cell lysate containing cell constituents, such as nucleic acids, carbohydrates, metabolites, and proteins into a continuous flow of mineral oil. This platform enables accurate mixing of small volumes inside the meandering channels of the quartz chip and allows acquisition of thousands of SERS spectra with 785 nm excitation at an integration time of 1 s. Preparation of three batches of three leukemia cell lines demonstrated the experimental reproducibility. The main advantage of a high number of reproducible spectra is to apply statistics for large sample populations with robust classification results. A support vector machine with leave-one-batch-out cross-validation classified SERS spectra with sensitivities, specificities, and accuracies better than 99% to differentiate Jurkat, THP-1, and MONO-MAC-6 leukemia cell lysates. This approach is compared with previous published reports about Raman spectroscopy for leukemia detection, and an outlook is given for transfer to single cells. A quartz chip was designed for SERS at 785 nm excitation. Principal component analysis of SERS spectra clearly separates cell lysates using variations in band intensity ratios.


Asunto(s)
Leucemia/diagnóstico , Técnicas Analíticas Microfluídicas/instrumentación , Espectrometría Raman/instrumentación , Línea Celular Tumoral , Diseño de Equipo , Humanos , Nanopartículas del Metal/química , Técnicas Analíticas Microfluídicas/métodos , Plata/química , Sonicación , Espectrometría Raman/métodos
9.
Contemp Clin Trials ; 56: 46-51, 2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28279782

RESUMEN

BACKGROUND: In patients with suspected prostate cancer (PCa) according to current guidelines systematic transrectal ultrasound (TRUS)-guided biopsy of the prostate is performed to verify or rule out PCa. However, TRUS-guided biopsy can result in underdetection of clinically significant cancers as well as diagnosis of clinically insignificant cancers. Multiparametric MRI (mpMRI) might improve the diagnostic pathway and help to avoid unnecessary biopsies. DESIGN AND METHODS: The PROKOMB (Prostata - Kooperatives MRT-Projekt Berlin) study is a prospective two-arm multicentre study designed to evaluate the potential role of mpMRI as a triage test before biopsy. Up to 600 biopsy-naïve men with suspicion for PCa undergo mpMRI at two dedicated imaging centers. Only patients with equivocal or suspicious lesions on mpMRI undergo prostate biopsy including systematic as well as MRI-guided targeted biopsies at several different community-based urologists or hospitals. The PROKOMB study is designed to evaluate how many biopsies can be avoided, how many clinically insignificant cancers are diagnosed on prostate biopsy in patients with positive findings on mpMRI, and how many clinically significant cancers are missed using this alternative diagnostic pathway. For the purpose of this study clinically significant PCa is defined as Gleason ≥3+4 cancer. In addition, the detection rates of different techniques for MRI-guided biopsy are evaluated as well as psychological distress before mpMRI and after the diagnosis of PCa. CONCLUSION: The PROKOMB study might help in defining the role of mpMRI in biopsy-naïve patients with suspected PCa in an ambulatory care setting.


Asunto(s)
Imagen por Resonancia Magnética/métodos , Neoplasias de la Próstata/diagnóstico , Adolescente , Adulto , Anciano , Biopsia/métodos , Imagen de Difusión por Resonancia Magnética , Reacciones Falso Negativas , Imagen por Resonancia Magnética con Fluor-19 , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Antígeno Prostático Específico , Neoplasias de la Próstata/diagnóstico por imagen , Neoplasias de la Próstata/psicología , Proyectos de Investigación , Estrés Psicológico/epidemiología , Adulto Joven
10.
Pharmacol Res Perspect ; 4(4): e00230, 2016 08.
Artículo en Inglés | MEDLINE | ID: mdl-28116092

RESUMEN

Enhanced expression of the proteinase-activated receptor 2 (PAR2) is linked to cell proliferation and migration in many cancer cell types. The role of PAR2 in cancer progression strongly illustrates the need for PAR2-inhibiting compounds. However, to date, potent and selective PAR2 antagonists have not been reported. The natural product teleocidin A2 was characterized against PAR2-activating peptide SLIGKV-NH 2, and trypsin-induced PAR2-dependent intracellular Ca2+ mobilization in tumor and in primary endothelial or epithelial cells. Further biochemical and cell-based studies were conducted to evaluate teleocidin specificity. The antagonizing effect of teleocidin A2 was confirmed in PAR2-dependent cell migration and rearrangement of actin cytoskeleton of human breast adenocarcinoma cell line (MDA-MB 231) breast cancer cells. Teleocidin A2 antagonizes PAR2-dependent intracellular Ca2+ mobilization induced by either SLIGKV-NH 2 or trypsin with IC 50 values from 15 to 25 nmol/L in MDA-MB 231, lung carcinoma cell line, and human umbilical vein endothelial cell. Half maximal inhibition of either PAR1 or P2Y receptor-dependent Ca2+ release is only achieved with 10- to 20-fold higher concentrations of teleocidin A2. In low nanomolar concentrations, teleocidin A2 reverses both SLIGKV-NH 2 and trypsin-mediated PAR2-dependent migration of MDA-MB 231 cells, and has no effect itself on cell migration and no effect on cell viability. Teleocidin A2 further controls PAR2-induced actin cytoskeleton rearrangement of MDA-MB 231 cells. Thus, for the first time, the small molecule natural product teleocidin A2 exhibiting PAR2 antagonism in the low nanomolar range with potent antimigratory activity is described.

11.
Mod Pathol ; 28(12): 1528-34, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26403781

RESUMEN

Recently the American Society of Clinical Oncology and the College of American Pathologists have updated their clinical practice guidelines for HER2 testing in breast cancer. In order to evaluate these new recommendations, we have re-assessed the HER2 status of 6018 breast cancer cases of the screening population for the HERceptin adjuvant (HERA) trial that were originally centrally tested by fluorescence in situ hybridization based on the FDA-released test guidelines. According to the most recent 2013 ASCO/CAP recommendations, 3380 (56.2%) cases were classified as HER2 positive compared with 3359 (55.8%) applying the HERA/FDA scheme and 3339 (55.5%) applying the 2007 ASCO/CAP guidelines. Twenty-one cases switched from negative (HERA/FDA scheme) to positive (2013 ASCO/CAP guidelines). This group is characterized by a mean HER2 gene copy number of ≥6.0, polysomy or co-amplification of CEP17 with an average CEP17 count of 5, and with HER2 receptor overexpression in 75% of cases. On the basis of the HER2 gene copy number alone, we observe 494 cases (8.2%) that are in the equivocal range. Most of these cases (>80%) were also nondecisive by immunohistochemistry (score 2+) irrespective of whether ratio was <2.0>. The number of equivocal cases that would require HER2 reflex testing decreases to 113 (1.9%) if in addition to the HER2 gene copy number also the ratio of HER2 and CEP17 copy numbers is considered via dual-color in situ hybridization. The combination of applying the HER2 mean gene copy number as well as the HER2/CEP17 ratio to define equivocal test decisions by fluorescence in situ hybridization as proposed by the current ASCO/CAP guidelines appears to be a more optimum approach to adopt in order to avoid or minimize reporting of false negative results. Using the mean HER2 gene copy number alone for decision making results in a significant increase of equivocal cases.


Asunto(s)
Biomarcadores de Tumor/análisis , Neoplasias de la Mama/genética , Hibridación Fluorescente in Situ/métodos , Guías de Práctica Clínica como Asunto , Receptor ErbB-2/análisis , Antineoplásicos/uso terapéutico , Biomarcadores de Tumor/genética , Neoplasias de la Mama/tratamiento farmacológico , Femenino , Humanos , Trastuzumab/uso terapéutico
12.
J Thorac Oncol ; 10(7): 1049-57, 2015 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26102443

RESUMEN

INTRODUCTION: The Network Genomic Medicine Lung Cancer was set up to rapidly translate scientific advances into early clinical trials of targeted therapies in lung cancer performing molecular analyses of more than 3500 patients annually. Because sequential analysis of the relevant driver mutations on fixated samples is challenging in terms of workload, tissue availability, and cost, we established multiplex parallel sequencing in routine diagnostics. The aim was to analyze all therapeutically relevant mutations in lung cancer samples in a high-throughput fashion while significantly reducing turnaround time and amount of input DNA compared with conventional dideoxy sequencing of single polymerase chain reaction amplicons. METHODS: In this study, we demonstrate the feasibility of a 102 amplicon multiplex polymerase chain reaction followed by sequencing on an Illumina sequencer on formalin-fixed paraffin-embedded tissue in routine diagnostics. Analysis of a validation cohort of 180 samples showed this approach to require significantly less input material and to be more reliable, robust, and cost-effective than conventional dideoxy sequencing. Subsequently, 2657 lung cancer patients were analyzed. RESULTS: We observed that comprehensive biomarker testing provided novel information in addition to histological diagnosis and clinical staging. In 2657 consecutively analyzed lung cancer samples, we identified driver mutations at the expected prevalence. Furthermore we found potentially targetable DDR2 mutations at a frequency of 3% in both adenocarcinomas and squamous cell carcinomas. CONCLUSION: Overall, our data demonstrate the utility of systematic sequencing analysis in a clinical routine setting and highlight the dramatic impact of such an approach on the availability of therapeutic strategies for the targeted treatment of individual cancer patients.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/genética , Carcinoma de Pulmón de Células no Pequeñas/terapia , Neoplasias Pulmonares/genética , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/genética , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Estudios de Cohortes , ADN de Neoplasias/análisis , ADN de Neoplasias/genética , ADN de Neoplasias/aislamiento & purificación , Humanos , Neoplasias Pulmonares/diagnóstico , Neoplasias Pulmonares/terapia , Reacción en Cadena de la Polimerasa/métodos , Análisis de Secuencia de ADN/métodos
13.
Bioorg Med Chem ; 22(18): 5110-6, 2014 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-24530033

RESUMEN

Natural products represent compound classes with high chemical and structural diversity and various biological activities. Libraries based on natural products are valuable starting point in the search for novel biologically active substances. Here we report on the identification of the natural product podoverine A from the plant Podophyllum versipelle Hance as a novel tubulin-acting agent. A natural product compound collection was subjected to a high-content screen that monitors changes in cytoskeleton and DNA and podoverine A was identified as inhibitor of mitosis. This natural product causes mitotic arrest and inhibits microtubule polymerization in vitro and in cells by targeting the vinca binding site on tubulin.


Asunto(s)
Antineoplásicos Fitogénicos/farmacología , Productos Biológicos/farmacología , Flavonas/farmacología , Microtúbulos/efectos de los fármacos , Podophyllum/química , Moduladores de Tubulina/farmacología , Animales , Antineoplásicos Fitogénicos/química , Antineoplásicos Fitogénicos/aislamiento & purificación , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Ciclo Celular/efectos de los fármacos , Línea Celular , Proliferación Celular/efectos de los fármacos , Chlorocebus aethiops , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Flavonas/química , Flavonas/aislamiento & purificación , Células HeLa , Humanos , Células MCF-7 , Microtúbulos/metabolismo , Estructura Molecular , Polimerizacion/efectos de los fármacos , Relación Estructura-Actividad , Moduladores de Tubulina/química , Moduladores de Tubulina/aislamiento & purificación
14.
J Hand Surg Am ; 38(5): 999-1005, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23618456

RESUMEN

Arthrodesis of a painful and destroyed wrist is one of the key operations in patients with rheumatoid arthritis. Clayton is given credit for the first description of an operative technique of wrist arthrodesis by means of an intramedullary Steinmann pin. Mannerfelt popularized this technique by using a Rush pin and additional fixation with staples. The aim of the present article is to give a detailed description of the operative technique used in our hospital. Over a period of 13 years, 104 modified Clayton-Mannerfelt arthrodeses were performed in 87 patients with rheumatoid arthritis. Ninety-three wrists were reviewed clinically and radiographically. The patients had high fusion rates and a reliable reduction in preoperative pain, with a low rate of complications. The pin technique is more versatile than standard wrist arthrodesis plates, and the wrist can be positioned according to the needs of the patient. This technique seems to be a good alternative to conventional wrist arthrodesis using an arthrodesis plate in wrists destroyed by rheumatoid arthritis, even in situations with difficult bone stock. In most cases, it is not necessary to remove the hardware.


Asunto(s)
Artritis Reumatoide/cirugía , Artrodesis/métodos , Articulación de la Muñeca/cirugía , Adulto , Anciano , Huesos del Carpo/cirugía , Femenino , Humanos , Cápsula Articular/cirugía , Masculino , Persona de Mediana Edad , Estudios Retrospectivos , Técnicas de Sutura
15.
Anal Bioanal Chem ; 405(8): 2743-6, 2013 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-23371531

RESUMEN

Three important technical innovations are reported here towards Raman-activated cell sorting. Firstly, a microfluidic chip made of quartz is introduced which integrates injection of single cells, trapping by laser fibres and sorting of cells. Secondly, a chip holder was designed to provide simple, accurate and stable adjustment of chips, microfluidic connections and the trapping laser fibres. The new setup enables to the collection of Raman spectra of single cells at 785 nm excitation with 10 s exposure time. Lastly, a new type of modelling the various background contributions is described, improving Raman-based cell identification by the classification algorithm linear discriminant analysis. Mean sensitivity and specificity determined by iterated 10-fold cross validation were 96 and 99 %, respectively, for the distinction of leucocytes extracted from blood, breast cancer cells BT-20 and MCF-7, and leukaemia cells OCI-AML3.


Asunto(s)
Células/química , Microfluídica/métodos , Espectrometría Raman/métodos , Línea Celular Tumoral , Humanos , Microfluídica/instrumentación , Pinzas Ópticas , Cuarzo , Espectrometría Raman/instrumentación
16.
Lab Chip ; 13(6): 1109-13, 2013 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-23344502

RESUMEN

An all-fibre based Raman-on-chip setup is introduced which enables analysis of solutions and trapped particles without microscopes or objectives. Beside the novel quartz microfluidic chip, innovative multi-core single-mode fibres with integrated fibre Bragg gratings are used for detection. The limit of quantitation is 7.5 mM for urea and 2.5 mM for nicotine with linear Raman spectroscopy. This is an improvement of more than two orders of magnitude compared with previous fibre-based microfluidic Raman detection schemes. Furthermore, our device was combined with optical traps to collect Raman-on-chip spectra of spherical polymer beads.


Asunto(s)
Técnicas Analíticas Microfluídicas/métodos , Nicotina/análisis , Espectrometría Raman , Urea/análisis , Calibración , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/normas , Nicotina/normas , Soluciones/química , Urea/normas
17.
Lab Chip ; 11(8): 1484-90, 2011 Apr 21.
Artículo en Inglés | MEDLINE | ID: mdl-21340095

RESUMEN

Raman spectroscopy has been recognized to be a powerful tool for label-free discrimination of cells. Sampling methods are under development to utilize the unique capabilities to identify cells in body fluids such as saliva, urine or blood. The current study applied optical traps in combination with Raman spectroscopy to acquire spectra of single cells in microfluidic glass channels. Optical traps were realized by two 1070 nm single mode fibre lasers. Microflows were controlled by a syringe pump system. A novel microfluidic glass chip was designed to inject single cells, modify the flow speed, accommodate the laser fibres and sort cells after Raman based identification. Whereas the integrated microchip setup used 514 nm for excitation of Raman spectra, a quartz capillary setup excited spectra with 785 nm laser wavelength. Classification models were trained using linear discriminant analysis to differentiate erythrocytes, leukocytes, acute myeloid leukaemia cells (OCI-AML3), and breast tumour cells BT-20 and MCF-7 with accuracies that are comparable with previous Raman experiments of dried cells and fixed cells in a Petri dish. Implementation into microfluidic environments enables a high degree of automation that is required to improve the throughput of the approach for Raman activated cell sorting.


Asunto(s)
Separación Celular/instrumentación , Técnicas Analíticas Microfluídicas/instrumentación , Pinzas Ópticas , Espectrometría Raman/instrumentación , Línea Celular Tumoral , Vidrio/química , Humanos , Rayos Láser
18.
J Biophotonics ; 2(4): 232-42, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19367591

RESUMEN

In this contribution a new approach for quantitative measurements using surface-enhanced Raman spectroscopy (SERS) is presented. Combining the application of isotope-edited internal standard with the advantages of the liquid-liquid segmented-flow-based approach for flow-through SERS detection seems to be a promising means for quantitative SERS analysis. For the investigations discussed here a newly designed flow cell, tested for ideal mixing efficiency on the basis of grayscale-value measurements, is implemented. Measurements with the heteroaromatics nicotine and pyridine using their respective deuterated isotopomers as internal standards show that the integration of an isotopically labeled internal standard in the used liquid-liquid two-phase segmented flow leads to reproducible and comparable SERS spectra independent from the used colloid. With the implementation of an internal standard into the microfluidic device the influence of the properties of the colloid on the SERS activity can be compensated. Thus, the problem of a poor batch-to-batch reproducibility of the needed nanoparticle solutions is solved. To the best of our knowledge these are the first measurements combining the above mentioned concepts in order to correct for differences in the enhancement behaviour of the respective colloid.


Asunto(s)
Técnicas Analíticas Microfluídicas/métodos , Sistemas en Línea , Espectrometría Raman/instrumentación , Espectrometría Raman/normas , Marcaje Isotópico , Nicotina/análisis , Piridinas/análisis , Estándares de Referencia , Reproducibilidad de los Resultados , Propiedades de Superficie , Factores de Tiempo
19.
ChemMedChem ; 3(4): 619-26, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18246567

RESUMEN

Natural products have provided the majority of lead structures for marketed antibacterials. In addition, they are biological guide principles to new therapies. Nevertheless, numerous "old" classes of antibiotics such as the longicatenamycins have never been explored by chemical postevolution. Longicatenamycin A is the first defined longicatenamycin congener that has been totally synthesized and tested in pure form. This venture required the de novo syntheses of the non-proteinogenic amino acids (2S,3R)-beta-hydroxyglutamic acid (HyGlu), 5-chloro-D-tryptophan (D-ClTrp), and (S)-2-amino-6-methylheptanoic acid (hhLeu). In the key step, the sensitive HyGlu building block was coupled as a pentafluorophenyl active ester to the unprotected H-D-ClTrp-Glu-hhLeu-D-Val-D-(Cbz)Orn-OH fragment. This first total synthesis of longicatenamycin A provided new congeners of the natural product (deacetyllongicatenamycin, dechlorolongicatenamycin, and longicatenamycin-A-amide).


Asunto(s)
Antibacterianos/síntesis química , Péptidos/síntesis química , Ciclización , Modelos Moleculares , Péptidos/química , Péptidos/farmacología , Relación Estructura-Actividad
20.
Int J Radiat Oncol Biol Phys ; 71(1): 28-35, 2008 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-18037588

RESUMEN

PURPOSE: To demonstrate how postimplantation analysis is useful for improving permanent seed implantation and reducing toxicity. PATIENTS AND METHODS: We evaluated 197 questionnaires completed by patients after permanent seed implantation (monotherapy between 1999 and 2003). For 70% of these patients, a computed tomography was available to perform postimplantation analysis. The index doses and volumes of the dose-volume histograms (DVHs) were determined and categorized with respect to the date of implantation. Differences in symptom scores relative to pretherapeutic status were analyzed with regard to follow-up times and DVH descriptors. Acute and subacute toxicities in a control group of 117 patients from an earlier study (June 1999 to September 2001) by Wust et al. (2004) were compared with a matched subgroup from this study equaling 110 patients treated between October 2001 and August 2003. RESULTS: Improved performance, identifying a characteristic time dependency of DVH parameters (after implantation) and toxicity scores, was demonstrated. Although coverage (volume covered by 100% of the prescription dose of the prostate) increased slightly, high-dose regions decreased with the growing experience of the users. Improvement in the DVH and a reduction of toxicities were found in the patient group implanted in the later period. A decline in symptoms with follow-up time counteracts this gain of experience and must be considered. Urinary and sexual discomfort was enhanced by dose heterogeneities (e.g., dose covering 10% of the prostate volume, volume covered by 200% of prescription dose). In contrast, rectal toxicities correlated with exposed rectal volumes, especially the rectal volume covered by 100% of the prescription dose. CONCLUSION: The typical side effects occurring after permanent seed implantation can be reduced by improving the dose distributions. An improvement in dose distributions and a reduction of toxicities were identified with elapsed time between 1999 and 2003.


Asunto(s)
Braquiterapia/normas , Neoplasias de la Próstata/radioterapia , Dosificación Radioterapéutica , Braquiterapia/efectos adversos , Braquiterapia/métodos , Encuestas Epidemiológicas , Humanos , Masculino , Neoplasias de la Próstata/patología , Encuestas y Cuestionarios , Factores de Tiempo , Carga Tumoral
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