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1.
Arch Gynecol Obstet ; 308(3): 935-940, 2023 09.
Article in English | MEDLINE | ID: mdl-36872392

ABSTRACT

PURPOSE: Breast surgery is usually performed under general anesthesia. Tumescent local anesthesia (TLA) offers the possibility to anesthetize large areas with highly diluted local anesthetic. METHODS: In this paper, the implementation, and experiences with TLA in the field of breast surgery are discussed. CONCLUSION: For carefully selected indications, breast surgery in TLA represents an alternative to ITN.


Subject(s)
Anesthesia, Local , Breast Neoplasms , Humans , Female , Anesthetics, Local , Mastectomy , Breast Neoplasms/surgery
2.
NMR Biomed ; 33(12): e4277, 2020 12.
Article in English | MEDLINE | ID: mdl-32124505

ABSTRACT

Multi-compartment T2 mapping has gained particular relevance for the study of myelin water in the brain. As a facilitator of rapid saltatory axonal signal transmission, myelin is a cornerstone indicator of white matter development and function. Regularized non-negative least squares fitting of multi-echo T2 data has been widely employed for the computation of the myelin water fraction (MWF), and the obtained MWF maps have been histopathologically validated. MWF measurements depend upon the quality of the data acquisition, B1+ homogeneity and a range of fitting parameters. In this special issue article, we discuss the relevance of these factors for the accurate computation of multi-compartment T2 and MWF maps. We generated multi-echo spin-echo T2 decay curves following the Carr-Purcell-Meiboom-Gill approach for various myelin concentrations and myelin T2 scenarios by simulating the evolution of the magnetization vector between echoes based on the Bloch equations. We demonstrated that noise and imperfect refocusing flip angles yield systematic underestimations in MWF and intra-/extracellular water geometric mean T2 (gmT2 ). MWF estimates were more stable than myelin water gmT2 time across different settings of the T2 analysis. We observed that the lower limit of the T2 distribution grid should be slightly shorter than TE1 . Both TE1 and the acquisition echo spacing also have to be sufficiently short to capture the rapidly decaying myelin water T2 signal. Among all parameters of interest, the estimated MWF and intra-/extracellular water gmT2 differed by approximately 0.13-4 percentage points and 3-4 ms, respectively, from the true values, with larger deviations observed in the presence of greater B1+ inhomogeneities and at lower signal-to-noise ratio. Tailoring acquisition strategies may allow us to better characterize the T2 distribution, including the myelin water, in vivo.


Subject(s)
Computer Simulation , Magnetic Resonance Imaging , Myelin Sheath/physiology , Spin Labels , Female , Humans , Least-Squares Analysis , Signal-To-Noise Ratio , Water , Young Adult
3.
Int J Hyperthermia ; 35(1): 463-470, 2018.
Article in English | MEDLINE | ID: mdl-30204024

ABSTRACT

PURPOSE: The aim of the study was to evaluate the efficacy of high intensity focused ultrasound (HIFU) in the treatment of symptomatic breast fibroadenomas (FA) after 6 and 12 months. MATERIALS AND METHODS: Between December 2013 and November 2014, 27 patients with histologically confirmed FA received one application of HIFU under local anesthesia (NCT02011919). Follow-up visits occurred after 6 and 12 months measuring the FA volume and clinical symptoms. A volume reduction of more than 65% was defined as success. Core needle biopsy (CNB) was offered after 12 months if indistinct residuals were visible on ultrasound (US). RESULTS: A successful reduction in FA volume after 12 months was achieved in 24/27 patients (89%). At baseline 16 patients (59%) had pain, which was resolved in 63% (10/16). All patients were satisfied with the cosmetic related outcome. Twenty-four patients (89%) would repeat the procedure. After 12 months 21 patients with sonographically indistinct residuals underwent a CNB. There were no vital cells in 86%. Three cases showed vital cells of FA. Retrospectively possible reasons in these three cases were an insufficient treatment due to bad visibility and insufficient fixation of the FA during HIFU and/or a too short follow-up time. CONCLUSION: US-guided HIFU is an effective procedure and a minimally invasive alternative for the treatment of breast FA.


Subject(s)
Fibroadenoma/diagnostic imaging , Fibroadenoma/therapy , High-Intensity Focused Ultrasound Ablation/methods , Adolescent , Adult , Female , Fibroadenoma/pathology , Humans , Middle Aged , Treatment Outcome , Young Adult
4.
Neuroimage ; 130: 157-166, 2016 Apr 15.
Article in English | MEDLINE | ID: mdl-26854557

ABSTRACT

Despite the constant improvement of algorithms for automated brain tissue classification, the accurate delineation of subcortical structures using magnetic resonance images (MRI) data remains challenging. The main difficulties arise from the low gray-white matter contrast of iron rich areas in T1-weighted (T1w) MRI data and from the lack of adequate priors for basal ganglia and thalamus. The most recent attempts to obtain such priors were based on cohorts with limited size that included subjects in a narrow age range, failing to account for age-related gray-white matter contrast changes. Aiming to improve the anatomical plausibility of automated brain tissue classification from T1w data, we have created new tissue probability maps for subcortical gray matter regions. Supported by atlas-derived spatial information, raters manually labeled subcortical structures in a cohort of healthy subjects using magnetization transfer saturation and R2* MRI maps, which feature optimal gray-white matter contrast in these areas. After assessment of inter-rater variability, the new tissue priors were tested on T1w data within the framework of voxel-based morphometry. The automated detection of gray matter in subcortical areas with our new probability maps was more anatomically plausible compared to the one derived with currently available priors. We provide evidence that the improved delineation compensates age-related bias in the segmentation of iron rich subcortical regions. The new tissue priors, allowing robust detection of basal ganglia and thalamus, have the potential to enhance the sensitivity of voxel-based morphometry in both healthy and diseased brains.


Subject(s)
Algorithms , Brain Mapping/methods , Brain/anatomy & histology , Image Processing, Computer-Assisted/methods , Adult , Aged , Aged, 80 and over , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Young Adult
5.
Neuroimage ; 103: 280-289, 2014 Dec.
Article in English | MEDLINE | ID: mdl-25264230

ABSTRACT

Evidence from magnetic resonance imaging (MRI) studies shows that healthy aging is associated with profound changes in cortical and subcortical brain structures. The reliable delineation of cortex and basal ganglia using automated computational anatomy methods based on T1-weighted images remains challenging, which results in controversies in the literature. In this study we use quantitative MRI (qMRI) to gain an insight into the microstructural mechanisms underlying tissue ageing and look for potential interactions between ageing and brain tissue properties to assess their impact on automated tissue classification. To this end we acquired maps of longitudinal relaxation rate R1, effective transverse relaxation rate R2* and magnetization transfer - MT, from healthy subjects (n=96, aged 21-88 years) using a well-established multi-parameter mapping qMRI protocol. Within the framework of voxel-based quantification we find higher grey matter volume in basal ganglia, cerebellar dentate and prefrontal cortex when tissue classification is based on MT maps compared with T1 maps. These discrepancies between grey matter volume estimates can be attributed to R2* - a surrogate marker of iron concentration, and further modulation by an interaction between R2* and age, both in cortical and subcortical areas. We interpret our findings as direct evidence for the impact of ageing-related brain tissue property changes on automated tissue classification of brain structures using SPM12. Computational anatomy studies of ageing and neurodegeneration should acknowledge these effects, particularly when inferring about underlying pathophysiology from regional cortex and basal ganglia volume changes.


Subject(s)
Aging/pathology , Brain Chemistry/physiology , Brain Mapping/methods , Brain/pathology , Iron/analysis , Adult , Aged , Aged, 80 and over , Atrophy/metabolism , Atrophy/pathology , Brain/metabolism , Female , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Middle Aged , Young Adult
6.
Breast Cancer Res Treat ; 138(2): 509-17, 2013 Apr.
Article in English | MEDLINE | ID: mdl-23494674

ABSTRACT

Overexpression of the HER2-receptor in early breast cancer (EBC) patients is associated with aggressive tumor behavior. However, women suffering from HER2-positive EBC benefit from trastuzumab treatment. As the HER2 status of the primary tumor may differ from that of disseminated tumor cells (DTC) in bone marrow (BM), the aim of this study was (1) to compare the HER2 status of the primary tumor (prim-HER2-status) with that of DTC (DTC-HER2-status) and (2) to analyze the influence of the DTC-HER2-status on patient survival. For this purpose, BM aspirates from 569 EBC patients were analyzed for the presence of DTC. The DTC-HER2-status was identified by a double-staining procedure against cytokeratin and the HER2-receptor. DTC were detected in 151 (27 %) patients. The concordance between the HER2 status of DTC and the primary tumor was 51 %. In patients with detectable DTC, mean disease-free survival was 77.44 (95 % CI 74.72-80.17) months for DTC-HER2-negative and 55.15 (95 % CI 48.57-61.79) months for DTC-HER2-positive patients (p = 0.044). The multivariate analysis showed that the DTC-HER2-status was an independent predictor of disease-free survival. In conclusion, the presence of HER2-positive DTC in EBC patients is associated with an increased risk of relapse. Due to the low concordance between the HER2 status of the primary tumor and DTC, only a minority (13 %) of the DTC-HER2-positive patients was treated with trastuzumab. These patients might, however, benefit from HER2-directed therapy.


Subject(s)
Bone Marrow/pathology , Breast Neoplasms/metabolism , Carcinoma, Ductal, Breast/metabolism , Neoplasm Recurrence, Local/metabolism , Receptor, ErbB-2/metabolism , Antibodies, Monoclonal, Humanized/therapeutic use , Antineoplastic Agents/therapeutic use , Bone Marrow Cells/metabolism , Bone Marrow Cells/pathology , Breast Neoplasms/drug therapy , Breast Neoplasms/mortality , Breast Neoplasms/pathology , Carcinoma, Ductal, Breast/drug therapy , Carcinoma, Ductal, Breast/mortality , Carcinoma, Ductal, Breast/secondary , Disease-Free Survival , Female , Humans , Kaplan-Meier Estimate , Multivariate Analysis , Neoplasm Recurrence, Local/prevention & control , Proportional Hazards Models , Trastuzumab
7.
J Magn Reson Imaging ; 36(6): 1329-38, 2012 Dec.
Article in English | MEDLINE | ID: mdl-22911904

ABSTRACT

PURPOSE: To apply myelin-sensitive quantitative magnetic resonance imaging (MRI) techniques in defined hypomyelinating conditions and to identify spatial patterns of myelination as criteria for characterization of undefined disorders. MATERIALS AND METHODS: Seven patients were included, based on the diagnosis of mitochondrial cytopathy, Pelizaeus-Merzbacher disease, GJA12/GJC2-related Pelizaeus-Merzbacher-like disease, hypomyelination with atrophy of the basal ganglia and cerebellum, and leukoencephalopathy with ataxia, delayed dentition, and hypomyelination. The control group comprised 23 children and adolescents (age range 2.6-22.4 years). The 3T MRI protocol consisted of high-resolution T1- and T2-weighted 3D MRI, diffusion tensor (DTI), and magnetization transfer (MT) imaging. Parameter maps of mean diffusivity, fractional anisotropy, and MT saturation were displayed as pseudocolor overlays and assessed by region-of-interest and histogram analysis. RESULTS: Structural MRI revealed widespread signal alterations in white matter, but were hampered by signal heterogeneity. Quantitative DTI and MT reflected the degree of hypomyelination and discriminative patterns of myelination emerged on MT saturation maps. CONCLUSION: The quantitative parameters in the defined hypomyelination conditions provide additional criteria to further classify undefined white matter disorders.


Subject(s)
Brain/pathology , Demyelinating Diseases/pathology , Diffusion Tensor Imaging/methods , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Nerve Fibers, Myelinated/pathology , Pattern Recognition, Automated/methods , Adolescent , Algorithms , Child , Child, Preschool , Female , Humans , Image Enhancement/methods , Infant , Male , Reproducibility of Results , Sensitivity and Specificity
8.
Neuroimage ; 56(3): 1164-70, 2011 Jun 01.
Article in English | MEDLINE | ID: mdl-21324367

ABSTRACT

Voxel-based morphometry (VBM) is a widely applied method in computational neurosciences but it is currently recommended to compare only data collected at a single MRI scanner. Multi-site VBM would be a desirable approach to increase group size and, thus, statistical power. We aimed to assess if multi-site VBM is feasible on similar hardware and compare the magnitude of inter- and intra-scanner differences. 18 healthy subjects were scanned in two identical 3T MRI scanners using different head coil designs, twice in scanner A and once in scanner B. 3D T1-weighted images were processed with SPM8 and FSL4.1 and compared as paired t-test (scan versus re-scan) on a voxel basis by means of a general linear model (GLM). Additionally, coefficient-of-difference (coeffD) maps were calculated for respective pairs of gray matter segmentations. We found considerable inter-scanner differences clearly exceeding a commonly used GLM significance threshold of p<0.05 (FWE corrected). The spatial pattern of detected differences was dependent on whether SPM8 or FSL4.1 was used. The inclusion of global correcting factors either aggravated (SPM8) or reduced the GLM detected differences (FSL4.1). The coeffD analysis revealed markedly higher variability within the FSL4.1 stream both for the inter- and the intra-scanner comparison. A lowered bias cutoff (30 mm FWHM) in SPM8 improved the comparability for cortical areas. Intra-scanner scan/re-scan differences were generally weaker and did not exceed a p<0.05 (FWE corrected) threshold in the GLM analysis. At 3T profound inter-scanner differences are to be expected that could severely confound an unbalanced VBM analysis. These are like related to the receive bias of the radio-frequency hardware.


Subject(s)
Image Processing, Computer-Assisted/methods , Magnetic Resonance Imaging/methods , Algorithms , Brain Mapping/methods , Humans , Linear Models , Magnetic Resonance Imaging/instrumentation , Magnetic Resonance Imaging/statistics & numerical data , Regression Analysis , Reproducibility of Results , Software
9.
Neuroimage ; 55(4): 1423-34, 2011 Apr 15.
Article in English | MEDLINE | ID: mdl-21277375

ABSTRACT

Normal ageing is associated with characteristic changes in brain microstructure. Although in vivo neuroimaging captures spatial and temporal patterns of age-related changes of anatomy at the macroscopic scale, our knowledge of the underlying (patho)physiological processes at cellular and molecular levels is still limited. The aim of this study is to explore brain tissue properties in normal ageing using quantitative magnetic resonance imaging (MRI) alongside conventional morphological assessment. Using a whole-brain approach in a cohort of 26 adults, aged 18-85years, we performed voxel-based morphometric (VBM) analysis and voxel-based quantification (VBQ) of diffusion tensor, magnetization transfer (MT), R1, and R2* relaxation parameters. We found age-related reductions in cortical and subcortical grey matter volume paralleled by changes in fractional anisotropy (FA), mean diffusivity (MD), MT and R2*. The latter were regionally specific depending on their differential sensitivity to microscopic tissue properties. VBQ of white matter revealed distinct anatomical patterns of age-related change in microstructure. Widespread and profound reduction in MT contrasted with local FA decreases paralleled by MD increases. R1 reductions and R2* increases were observed to a smaller extent in overlapping occipito-parietal white matter regions. We interpret our findings, based on current biophysical models, as a fingerprint of age-dependent brain atrophy and underlying microstructural changes in myelin, iron deposits and water. The VBQ approach we present allows for systematic unbiased exploration of the interaction between imaging parameters and extends current methods for detection of neurodegenerative processes in the brain. The demonstrated parameter-specific distribution patterns offer insights into age-related brain structure changes in vivo and provide essential baseline data for studying disease against a background of healthy ageing.


Subject(s)
Aging/pathology , Brain/cytology , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Magnetic Resonance Imaging/methods , Nerve Fibers, Myelinated/ultrastructure , Neurons/cytology , Adolescent , Adult , Aged , Aged, 80 and over , Female , Humans , Image Enhancement/methods , Male , Middle Aged , Reproducibility of Results , Sensitivity and Specificity , Young Adult
10.
NMR Biomed ; 23(5): 441-5, 2010 Jun.
Article in English | MEDLINE | ID: mdl-20175147

ABSTRACT

Adenylosuccinate lyase (ADSL) deficiency is an inherited metabolic disorder affecting predominantly the central nervous system. The disease is characterized by the accumulation of succinylaminoimidazolecarboxamide riboside and succinyladenosine (S-Ado) in tissue and body fluids. Three children presented with muscular hypotonia, psychomotor delay, behavioral abnormalities, and white matter changes on brain MRI. Two of them were affected by seizures. Screening for inborn errors of metabolism including in vitro high resolution proton MRS revealed an ADSL deficiency that was confirmed genetically in all cases. All patients were studied by in vivo proton MRS. In vitro high resolution proton MRS of patient cerebrospinal fluid showed singlet resonances at 8.27 and 8.29 ppm that correspond to accumulated S-Ado. In vivo proton MRS measurements also revealed a prominent signal at 8.3 ppm in gray and white matter brain regions of all patients. The resonance was undetectable in healthy human brain. In vivo proton MRS provides a conclusive finding in ADSL deficiency and represents a reliable noninvasive diagnostic tool for this neurometabolic disorder.


Subject(s)
Adenylosuccinate Lyase/deficiency , Protons , Purine-Pyrimidine Metabolism, Inborn Errors/diagnosis , Purine-Pyrimidine Metabolism, Inborn Errors/enzymology , Aminoimidazole Carboxamide/analogs & derivatives , Aminoimidazole Carboxamide/cerebrospinal fluid , Aminoimidazole Carboxamide/urine , Child , Child, Preschool , Female , Humans , Hydrogen-Ion Concentration , Infant , Infant, Newborn , Magnetic Resonance Imaging , Magnetic Resonance Spectroscopy , Male , Purine-Pyrimidine Metabolism, Inborn Errors/cerebrospinal fluid , Purine-Pyrimidine Metabolism, Inborn Errors/urine , Ribonucleotides/cerebrospinal fluid , Ribonucleotides/urine , S-Adenosylmethionine/cerebrospinal fluid , S-Adenosylmethionine/urine
11.
Clin Exp Metastasis ; 35(8): 777-783, 2018 12.
Article in English | MEDLINE | ID: mdl-30324492

ABSTRACT

Optimization of axillary staging among patients converting from clinically node-positive disease to clinically node-negative disease through primary systemic therapy is needed. We aimed at developing a nomogram predicting the probability of positive axillary status after chemotherapy based on clinical/pathological parameters. Patients from study arm C of the SENTINA trial were included. Univariable/multivariable analyses were performed for 13 clinical/pathological parameters to predict a positive pathological axillary status after chemotherapy using logistic regression models. Odds ratios and 95%-confidence-intervals were reported. Model performance was assessed by leave-one-out cross-validation. Calculations were performed using the SAS Software (Version 9.4, SAS Institute Inc., Cary, NC, USA). 369 of 553 patients in Arm C were included in multivariable analysis. Stepwise backward variable selection based on a multivariable analysis resulted in a model including estrogen receptor (ER) status (odds ratio (OR) 3.916, 95% confidence interval (CI) 2.318-6.615, p < 0.001), multifocality (OR 2.106, 95% CI 1.203-3.689, p = 0.0092), lymphovascular invasion (OR 9.196, 95% CI 4.734-17.864, p < 0.001), and sonographic tumor diameter after PST (OR 1.034, 95% CI 1.010-1.059, p = 0.0051). When validated, our model demonstrated an accuracy of 70.2% using 0.5 as cut-point. An area under the curve of 0.81 was calculated. The use of individual parameters as predictors of lymph node status after chemotherapy resulted in an inferior accuracy. Our model was able to predict the probability of a positive axillary nodal status with a high accuracy. The use of individual parameters showed reduced predictive performance. Overall, tumor biology was the strongest parameter in our models.


Subject(s)
Breast Neoplasms/pathology , Lymphatic Metastasis/pathology , Neoplasm Staging/methods , Nomograms , Adult , Aged , Antineoplastic Agents/therapeutic use , Area Under Curve , Axilla , Breast Neoplasms/drug therapy , Chemotherapy, Adjuvant , Female , Humans , Lymphatic Metastasis/diagnosis , Middle Aged , Neoadjuvant Therapy , ROC Curve , Sentinel Lymph Node/pathology , Sentinel Lymph Node Biopsy
12.
AJNR Am J Neuroradiol ; 28(6): 1093-4, 2007.
Article in English | MEDLINE | ID: mdl-17569965

ABSTRACT

Reliable identification of the subthalamic nucleus (STN) is a critical step in deep brain stimulation for Parkinson disease but difficult on T1-weighted stereotactic MR imaging. By simultaneous imaging of multiple gradient echoes, susceptibility contrast is added to conventional T1-weighted high-resolution MR image. Thus, the visibility of the STN is enhanced on a second co-localized dataset by exploiting the sensitivity of the T2*-relaxation to local iron deposits. The feasibility is underpinned by quantitative measurements on healthy adults.


Subject(s)
Algorithms , Echo-Planar Imaging/methods , Image Enhancement/methods , Image Interpretation, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Subthalamic Nucleus/anatomy & histology , Adult , Female , Humans , Male , Reproducibility of Results , Sensitivity and Specificity
13.
Dtsch Tierarztl Wochenschr ; 113(1): 24-7, 2006 Jan.
Article in German | MEDLINE | ID: mdl-16475551

ABSTRACT

Total hip endoprotheses are a good possibility for treatment degenerative wear and pathologic damage of the hip joint in man as well as in dogs. However, aseptic loosening of the protheses, especially in the area of the shaft, is still a problem in conventional total hip endoprotheses. The purpose of the present study was to use the finite-element-analysis (FEA), to enhance endoprothetic design and to prevent loosening of protheses. In order to simulate the femur of the dog for numerical analysis, a material law for the compacta in the femur of the dog was developed. The elastic properties of the compacta were experimentally determined by using compression tests of bone samples of euthanised dogs. The results show constant denseness and a constant axial elastic modul in the compacta.


Subject(s)
Femur/physiology , Animals , Compressive Strength , Dogs , Elasticity , Prosthesis Design
14.
Geobiology ; 14(6): 588-598, 2016 11.
Article in English | MEDLINE | ID: mdl-27384343

ABSTRACT

Bacteria in nature often live within biofilms, exopolymeric matrices that provide a favorable environment that can differ markedly from their surroundings. Biofilms have been found growing on mineral surfaces and are expected to play a role in weathering those surfaces, but a clear understanding of how environmental factors, such as trace-nutrient limitation, influence this role is lacking. Here, we examine biofilm development by Pseudomonas putida in media either deficient or sufficient in Fe during growth on biotite, an Fe rich mineral, or on glass. We hypothesized that the bacteria would respond to Fe deficiency by enhancing biotite dissolution and by the formation of binding sites to inhibit Fe leaching from the system. Glass coupons acted as a no-Fe control to investigate whether biofilm response depended on the presence of Fe in the supporting solid. Biofilms grown on biotite, as compared to glass, had significantly greater biofilm biomass, specific numbers of viable cells (SNVC), and biofilm cation concentrations of K, Mg, and Fe, and these differences were greater when Fe was deficient in the medium. Scanning electron microscopy (SEM) confirmed that biofilm growth altered the biotite surface, smoothing the rough, jagged edges of channels scratched by hand on the biotite, and dissolving away small, easy-to-access particles scattered across the planar surface. High-resolution magic angle spinning proton nuclear magnetic resonance (HRMAS 1 H NMR) spectroscopy showed that, in the Fe-deficient medium, the relative amount of polysaccharide nearly doubled relative to that in biofilms grown in the medium amended with Fe. The results imply that the bacteria responded to the Fe deficiency by obtaining Fe from biotite and used the biofilm matrix to enhance weathering and as a sink for released cation nutrients. These results demonstrate one mechanism by which biofilms may help soil microbes overcome nutrient deficiencies in oligotrophic systems.


Subject(s)
Aluminum Silicates/metabolism , Bacterial Physiological Phenomena , Biofilms/growth & development , Ferrous Compounds/metabolism , Iron/metabolism , Magnetic Resonance Spectroscopy , Microscopy, Electron, Scanning , Pinus/microbiology , Plant Roots/microbiology
15.
Toxicol Sci ; 88(1): 95-102, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16093524

ABSTRACT

Air pollution is positively associated with increased daily incidence of myocardial infarction and cardiovascular mortality. We hypothesize that air pollutants, primarily vapor phase organic compounds, cause an enhancement of coronary vascular constriction. Such events may predispose susceptible individuals to anginal symptoms and/or exacerbation of infarction. To develop this hypothesis, we studied the effects of nonparticulate diesel exhaust constituents on (1) electrocardiographic traces from ApoE-/- mice exposed whole-body and (2) isolated, pressurized septal coronary arteries from ApoE-/- mice. ApoE-/- mice were implanted with radiotelemetry devices to assess electrocardiogram (ECG) waveforms continuously throughout exposures (6 h/day x 3 days) to diesel exhaust (0.5 and 3.6 mg/m3) in whole-body inhalation chambers with or without particulates filtered. Significant bradycardia and T-wave depression were observed, regardless of the presence of particulates. Pulmonary inflammation was present only in the whole exhaust-exposed animals at the highest concentration. Fresh diesel exhaust or air was bubbled through the physiologic saline tissue bath prior to experiments to enable the isolated tissue exposure; exposed saline contained elevated levels of several volatile carbonyls and alkanes, but low to absent levels of polycyclic aromatic hydrocarbons. Vessels were then assayed for constrictive and dilatory function. Diesel components enhanced the vasoconstrictive effects of endothelin-1 and reduced the dilatory response to sodium nitroprusside. These data demonstrate that nonparticulate compounds in whole diesel exhaust elicit ECG changes consistent with myocardial ischemia. Furthermore, the volatile organic compounds in the vapor phase caused enhanced constriction and reduced dilatation in isolated coronary arteries caused by nonparticulate components of diesel exhaust.


Subject(s)
Air Pollutants/toxicity , Coronary Vessels/drug effects , Inhalation Exposure , Organic Chemicals/toxicity , Vasoconstriction/drug effects , Vehicle Emissions/toxicity , Animals , Bradycardia/chemically induced , Bradycardia/physiopathology , Coronary Vessels/physiopathology , Dose-Response Relationship, Drug , Electrocardiography , Heart Conduction System/drug effects , Heart Rate/drug effects , In Vitro Techniques , Male , Mice , Mice, Inbred C57BL , Mice, Knockout , Organic Chemicals/chemistry , Pneumonia/chemically induced , Pneumonia/pathology , Pneumonia/physiopathology , Telemetry , Vehicle Emissions/analysis , Volatilization
16.
Biomed Tech (Berl) ; 50(6): 174-80, 2005 Jun.
Article in German | MEDLINE | ID: mdl-16003918

ABSTRACT

UNLABELLED: PURPOSE. This work aims to present a preparation technique for ex-vivo MR examination of SPIO (superparamagnetic iron oxide) containing solutions or SPIO labeled cells. Accumulations of SPIO particles and labeled cells were prepared in different concentrations using agar gel phantoms. Signal extinction around accumulations of magnetic material was examined systematically by gradient echo sequences with variable echo times and spatial resolution. The correlation between local iron concentration and diameter of signal extinction in MR gradient echo images was investigated. METHODS: Resovist, (SHU 555A) was used as superparamagnetic contrast medium. Different concentrations of SPIO-containing solutions (0.75 - 15 mg Fe/10 ml) and magnetically labeled SK-Mel28 cells (25,000-1,000,000 cells/10 ml) were accommodated inside a defined volume in an agar matrix. Diameters of signal void were assessed in dependence on local iron concentration, echo time (5-25 ms) and isotropic spatial resolution (length of voxel 0.25 - 0.60 mm). Measurements were performed on a clinical MR whole body scanner (3 Tesla) using a spoiled gradient echo sequence (FLASH). RESULTS: For the present experimental conditions sensitivity to detect the magnetic label was maximized using TE 25 ms. In contrast, the area of signal cancellation was minimized using TE 5 ms and isotropic resolution of 0.25 mm. In the latter case the image indicated the area of magnetic material most precisely. Diameter of signal cancellation was a logarithmic function on local iron concentration. In the presented set-up detection of concentrations as low as 0.75 mg Fe/10 ml in SPIO-containing solution or 1.25 mg Fe/10 ml in SPIO-labeled SK-Mel28 cells was certainly possible. CONCLUSION: The proposed preparation strategy with a well defined spatial distribution of the magnetic material in an agar gel phantom produced reliable results and appears clearly superior compared to set-ups with randomly distributed material in glass tubes. The diameter of the signal extinction in gradient echo images was significantly affected by the choice of echo time and spatial resolution. The calibration of signal cancellation versus iron concentrations may be valuable to assess SPIO concentrations and possibly numbers of labeled cells under specific conditions in vitro or even in vivo.


Subject(s)
Complex Mixtures/analysis , Contrast Media/chemistry , Image Enhancement/methods , Iron/chemistry , Magnetic Resonance Imaging/methods , Melanoma/pathology , Oxides/chemistry , Cell Line, Tumor , Complex Mixtures/chemistry , Contrast Media/analysis , Contrast Media/chemical synthesis , Ferrosoferric Oxide , Humans , Iron/analysis , Materials Testing , Oxides/analysis , Oxides/chemical synthesis , Solutions , Staining and Labeling/methods
17.
Geburtshilfe Frauenheilkd ; 75(9): 935-940, 2015 Sep.
Article in English | MEDLINE | ID: mdl-26500370

ABSTRACT

Introduction: Detection of sentinel lymph nodes (SLN) is the standard procedure to evaluate axillary lymph node status in breast cancer. In addition to known and established procedures such as the blue dye method and scintigraphy, this study investigated the efficacy of a method based on use of the fluorescent dye indocyanine green (ICG). Patients and Method: A total of 126 women with breast cancer histologically verified by punch biopsy were studied during surgical removal of SLN. In addition to SLN marking with technetium and scintigraphy, intra-individual comparison was done using indocyanine green (ICG) for marking instead of the standard blue dye. Results: Scintigraphy had a detection rate of 96 %; the detection rate with ICG was just under 89 %. A body mass index (BMI) > 40 was found to be a limiting factor for the fluorescent method. Investigation into potential toxicities associated with the use of the fluorescent dye ICG revealed no systemic or even local side effects. The fluorescent method was found to be significantly less expensive than the scintigraphy method. Conclusion: The ICG fluorescence technique for the detection of SLN was found to be a valid and feasible method in clinical practice when compared directly with the blue dye method and scintigraphy.

18.
FEBS Lett ; 499(1-2): 182-6, 2001 Jun 15.
Article in English | MEDLINE | ID: mdl-11418136

ABSTRACT

To facilitate evaluation of enzyme-ligand complexes in solution, we have isolated the 26-kDa N-terminal domain of 5-enolpyruvylshikimate-3-phosphate (EPSP) synthase for analysis by NMR spectroscopy. The isolated domain is capable of binding the substrate shikimate-3-phosphate (S3P), and this letter reports the localization of the S3P binding site using chemical shift mapping. Based on the NMR data, we propose that Ser23, Arg27, Ser197, and Tyr200 are directly involved in S3P binding. We also describe changes in the observed nuclear Overhauser effects (NOEs) that are consistent with a partial conformational change in the N-terminal domain upon S3P binding.


Subject(s)
Alkyl and Aryl Transferases/chemistry , Alkyl and Aryl Transferases/metabolism , Shikimic Acid/analogs & derivatives , Shikimic Acid/metabolism , 3-Phosphoshikimate 1-Carboxyvinyltransferase , Amino Acid Sequence , Binding Sites , Models, Molecular , Molecular Sequence Data , Nuclear Magnetic Resonance, Biomolecular , Protein Binding , Protein Structure, Secondary , Protein Structure, Tertiary , Shikimic Acid/chemistry
19.
Phytochemistry ; 54(2): 183-9, 2000 May.
Article in English | MEDLINE | ID: mdl-10872209

ABSTRACT

(E,Z,Z)-1-Acetoxy-2-hydroxy-4-oxo-heneicosa-5,12,15-triene was isolated from avocado, Persea americana Mill., idioblast cells. It inhibited spore germination of the fungal pathogen Colletotrichum gloeosporioides. Full characterization is also reported for two additional compounds that have been described and partially characterized previously.


Subject(s)
Antifungal Agents/isolation & purification , Fatty Acids/isolation & purification , Lauraceae/chemistry , Antifungal Agents/chemistry , Antifungal Agents/pharmacology , Chromatography, High Pressure Liquid , Colletotrichum/drug effects , Fatty Acids/chemistry , Fatty Acids/pharmacology , Lauraceae/cytology , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Molecular Structure , Spectrophotometry, Infrared
20.
Phytochemistry ; 49(8): 2397-401, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9887532

ABSTRACT

Extracts of sclerotia from Sclerotinia sclerotiorum, a fungal phytopathogen, contain two electrochemically-active constituents, D-glycero-pent-2-enono-1,4-lactone (trivial name: D-erythroascorbic acid), and a previously unidentified compound, here characterized as 5-O-(alpha-D-galactopyranosyl)-D-glycero-pent-2-enono-1,4-lactone on the basis of its physical and chemical properties and its two hydrolytic products, D-galactose and D-erythroascorbic acid. Treatment of this galactoside with alkaline hydrogen peroxide produces oxalic acid as observed earlier with erythroascorbic acid.


Subject(s)
4-Butyrolactone/analogs & derivatives , Ascomycota/chemistry , Galactosides/isolation & purification , 4-Butyrolactone/chemistry , 4-Butyrolactone/isolation & purification , Galactosides/chemistry , Hydrogen Peroxide/chemistry , Hydrolysis , Magnetic Resonance Spectroscopy , Mass Spectrometry , Molecular Structure , Oxidation-Reduction
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