0000000000396714

AUTHOR

S. Walenta

showing 5 related works from this author

Abstract of the 68th Meeting (Spring Meeting) 6–9 March 1990, Heidelberg

1990

0303 health sciencesPhysiologyChemistryClinical BiochemistryTibialis AnteriorHuman physiology030204 cardiovascular system & hematologyPharmacologySpring (mathematics)ArticleAtrial Natriuretic Peptide03 medical and health sciences0302 clinical medicineAtrial natriuretic peptidePhysiology (medical)Spreading DepressionCapsaicinExtensor Digitorum Longus030304 developmental biologyPflugers Archiv
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Comparative imaging of structure and metabolites in tumours.

1991

A novel technique for metabolic imaging using quantitative bioluminescence and single photon imaging was used to measure the distribution of ATP and lactate in two types of human melanoma xenografts with different radiobiologically hypoxic cell fractions (MF: 45 +/- 17% and EE: 6 +/- 3%; mean +/- SD). The tumours were s.c. grown in nude mice and were used for measurement at volumes of 153-3072 mm3. For metabolic imaging the rapidly frozen tumours were serially sectioned, and each cryosection was brought into contact with a frozen bioluminescent enzyme cocktail using a specially designed glass sandwich system. After thawing section and cocktail the luminescence was started, and light was emi…

Pathologymedicine.medical_specialtyMetaboliteTransplantation HeterologousMice NudeBiologychemistry.chemical_compoundMiceAdenosine TriphosphatemedicineBioluminescenceAnimalsHumansRadiology Nuclear Medicine and imagingRadiosensitivityMelanomachemistry.chemical_classificationMice Inbred BALB CRadiological and Ultrasound Technologymedicine.diagnostic_testMelanomaMetabolismmedicine.diseaseMolecular biologyPhoton countingEnzymechemistryPositron emission tomographyLuminescent MeasurementsLactatesInternational journal of radiation biology
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Geographical mapping of metabolites in biological tissue with quantitative bioluminescence and single photon imaging

1993

This article features a novel technique for measuring the spatial distribution of metabolites, such as ATP, glucose, and lactate, in rapidly frozen tissue. Concentration values are obtained in absolute terms and with a spatial resolution of single-cell dimension. The method is based on enzymatic reactions that link the metabolite of interest to luciferase with subsequent light emission. Using a specific array, cryosections are brought into contact with the enzymes in a well-defined, reproducible way inducing a distribution of light across the section with an intensity that is proportional to the metabolite concentration. The emitted light can be visualized through a microscope and an imagin…

Cell SurvivalMetaboliteUterine Cervical NeoplasmsCarbohydrate metabolismBiologyMiceStructure-Activity Relationshipchemistry.chemical_compoundAdenosine TriphosphateNeoplasmsTumor Cells CulturedAnimalsFrozen SectionsHumansBioluminescenceTissue DistributionLuciferaseLactic AcidMelanomaCells Culturedchemistry.chemical_classificationMice Inbred BALB CStaining and LabelingHistocytochemistryMyocardiumCell BiologyPhoton countingRatsLactic acidGlucoseEnzymechemistryBiochemistryLuminescent MeasurementsLactatesBiophysicsFemaleLight emissionAnatomyThe Histochemical Journal
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Response of Chinese Hamster V79 Multicellular Spheroids Exposed to High-Energy Carbon Ions

2004

Chinese hamster V79-379A spheroids 200 +/- 30 microm (+/- SD) in diameter were irradiated in agitated medium in different oxygen atmospheres with (1) 227 MeV/nucleon (12)C(+6) ions (plateau region) to model tissue in the entrance channel during therapy, (2) carbon ions in the extended Bragg peak modeling tissue in the target volume, or (3) X rays as a reference modality. Cell survival curves were similar for modes (1) and (3), indicating the absence of a contact effect and the presence of a pronounced oxygen effect with oxygen enhancement ratios (OERs) of 2.8 and 2.9, respectively. In contrast, the oxygen effect was substantially smaller in mode (2) with an OER of 1.4. Under normal or restr…

Cell SurvivalBiophysicsAnalytical chemistrychemistry.chemical_elementApoptosisBragg peakRadiation DosageOxygenChinese hamsterCell LineIonCricetulusCricetinaeRelative biological effectivenessAnimalsRadiology Nuclear Medicine and imagingCarbon RadioisotopesIrradiationRadiationbiologyX-RaysCell CycleSpheroidDose-Response Relationship Radiationbiology.organism_classificationOxygenchemistryAtomic physicsCarbonCell DivisionRelative Biological EffectivenessRadiation Research
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Low light level in vitro monitoring of cellular and antigen-antibody reactions using a photon detection camera system — New perspectives for clinical…

1990

This article briefly describes the use of a photon counting system (ARGUS-100) in the detection of low levels of light. The ARGUS-100 was used in determining ATP in cell sections from tumor tissues and in measuring a luminescence-enhanced immunoluminometric assay, using ferritin as the analyte, based on the luminol-peroxide-4-iodophenol reaction with peroxidase as the enzyme. The aim is not so much the presentation of data, but rather to show the potentials of the photon counting camera in increasing our knowledge of the cellular and subcellular levels, as well as lowering the detection limits in already sensitive systems, such as immunoassays.

Blood GlucoseAnalyteVideo RecordingNanotechnologyAdenocarcinomaCell Linelaw.inventionAntigen-Antibody ReactionsImmunoenzyme TechniquesAdenosine TriphosphateMicrocomputersComputer SystemslawRhabdomyosarcomaDrug DiscoveryTumor Cells CulturedAnimalsHumansBioluminescenceLactic AcidGenetics (clinical)ChemiluminescenceDetection limitChemistrySignal Processing Computer-AssistedGeneral MedicineIn vitroPhoton countingRatsLow light levelClinical diagnosisLuminescent MeasurementsLactatesBiophysicsMolecular MedicineKlinische Wochenschrift
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