Search results for "densitometry"
showing 10 items of 38 documents
Specific inflammatory response of Anemonia sulcata (Cnidaria) after bacterial injection causes tissue reaction and enzymatic activity alteration
2015
The evolution of multicellular organisms was marked by adaptations to protect against pathogens. The mechanisms for discriminating the ’’self’’ from ’’non-self” have evolved into a long history of cellular and molecular strategies, from damage repair to the co-evolution of host-pathogen interactions. We investigated the inflammatory response in Anemonia sulcata (Cnidaria: Anthozoa) following injection of substances that varied in type and dimension, and observed clear, strong and specific reactions, especially after injection of Escherichia coli and Vibrio alginolyticus. Moreover, we analyzed enzymatic activity of protease, phosphatase and esterase, showing how the injection of different ba…
Scientific Merits and Analytical Challenges of Tree‐Ring Densitometry
2019
X-ray microdensitometry on annually resolved tree-ring samples has gained an exceptional position in last-millennium paleoclimatology through the maximum latewood density (MXD) parameter, but also increasingly through other density parameters. For 50 years, X-ray based measurement techniques have been the de facto standard. However, studies report offsets in the mean levels for MXD measurements derived from different laboratories, indicating challenges of accuracy and precision. Moreover, reflected visible light-based techniques are becoming increasingly popular, and wood anatomical techniques are emerging as a potentially powerful pathway to extract density information at the highest resol…
Zymographic analysis of circulating and tissue forms of colon carcinoma gelatinase A (MMP-2) and B (MMP-9) separated by mono- and two-dimensional ele…
2001
Gelatinase A (MMP-2) and gelatinase B (MMP-9) play a key role in the proteolytic cascade leading to ECM degradation during invasion and metastasis. The enzyme activity is regulated both at the intra- and extra-cellular level. Extracellular regulation is achieved mainly through the balance between proenzyme activation and inhibition, which appears to be altered in cancer patients. One of the mechanisms of MMP inhibition is the binding of the enzymes to appropriate tissue inhibitors (TIMP). In the recent literature, it has been suggested that MMP-2 and/or MMP-9 are indeed over-produced in many carcinomas, while the identity of the various enzymatic forms (latent, activated and enzyme/inhibito…
Pulmonary emphysema in cystic fibrosis detected by densitometry on chest multidetector computed tomography.
2013
BackgroundHistopathological studies on lung specimens from patients with cystic fibrosis (CF) and recent results from a mouse model indicate that emphysema may contribute to CF lung disease. However, little is known about the relevance of emphysema in patients with CF. In the present study, we used computationally generated density masks based on multidetector computed tomography (MDCT) of the chest for non-invasive characterization and quantification of emphysema in CF.MethodsVolumetric MDCT scans were acquired in parallel to pulmonary function testing in 41 patients with CF (median age 20.1 years; range 7-66 years) and 21 non-CF controls (median age 30.4 years; range 4-68 years), and subj…
Measuring corneal clouding in patients suffering from mucopolysaccharidosis with the Pentacam densitometry programme
2013
Aim To identify a means to objectively measure corneal clouding in patients with mucopolysaccharidosis in a prospective controlled clinical trial. Methods Corneal haze was assessed by slit lamp examination and measured using the densitometry programme of the Pentacam, a rotating Scheimpflug camera in 33 mucopolysaccharidoses (MPS) patients and 32 controls. Results Pentacam measurements were available in 31 right and 31 left eyes of 32 patients and in 32 left and right eyes of 32 subjects in the control group. Slit lamp findings correlated very well with corneal density measurements (Spearman correlation right eye (OD)/left eye (OS)=0.782/0.791). MPS patients had higher density units (median…
Parametric assessment of myocardial perfusion during interventional cardiac catheterization by means of X-ray densitometry-short-and long-term result…
1990
X-ray densitometric evaluation of digital subtraction angiocardiograms allows an assessment of myocardial perfusion by means of the parameter 'MEAN RISE TIME' (MRT), defined as the time from the onset of local myocardial contrast medium opacification to the point of maximum opacification. Best results are obtained when the response of that parameter is compared before and after stimulation of coronary flow by papaverine. A prolongation of this parameter, especially after papaverine, was indicative of an impairment of myocardial perfusion, when compared to the results of TL-201 scintigraphy. In 50 patients with single vessel coronary artery disease the results of MRT pre and post papaverine …
The effect of balloon dilatation on post-stenotic myocardial perfusion before and after stimulation of coronary flow reserve: evaluation by the densi…
1988
From densitometric evaluation of digital subtraction cineangiocardiograms the parameter 'Mean Rise Time' (MRT), defined as the time from the onset of local myocardial contrast medium opacification to the point of maximal opacification can be derived; this parameter revealed a close correlation with the results on myocardial perfusion obtained by Thallium-201 scintigraphy. A prolonged 'Mean Rise Time' was indicative of an impairment of myocardial perfusion. We have developed a heart-phase gated real-time digitization procedure and computer-supported method for the densitometric estimation of the MRT to obtain information about the effect of coronary balloon dilatation on myocardial perfusion…
Early diagnosis of osteoporosis by means of orthopantomograms and oral x-rays: a systematic review.
2011
Osteoporosis is a systemic bone disease that is characterized by a generalized reduction of the bone mass. It is the main cause of fractures in elderly women. Bone densitometry is used in the lumbar spine and hip in order to detect osteoporosis in its early stages. Different studies have observed a correlation between the bone mineral density of the jaw (BMD) and that of the lumbar spine and/or hip. On the other hand, there are studies that evaluate the findings in the orthopantomograms and perapical X-rays, correlating them with the early diagnosis of osteoporosis and highlighting the role of the dentist in the early diagnosis of this disease. Materials and methods: A search was carried ou…
Valutazione quantitativa tridimensionale del parenchima polmonare affetto da fibrosi cistica : risultati preliminari
2007
Purpose. The aim of this study was to assess the feasibility of three-dimensional (3D) reconstructions and quantitative analysis of the volume of each component of the lung with cystic fibrosis (CF). Materials and methods. Twenty-two patients with CF (mean age 17±8 yeas) were included in the study. The patients underwent an unenhanced single-slice spiral computed tomography (CT) chest scan with the following parameters: collimation 3 mm, table feed 6 mm×rot-1, reconstruction interval 1 mm, soft tissue reconstruction kernel. Four image data sets were obtained: native axial slices, cine-mode display, virtual bronchographic volumerendered images with algorithm for tissue transition display and…
A Sensitive Method for Identification of DNA Dependent DNA Polymerases in Acrylamide Gels after Seperation by Micro Disc Electrophoresis
1973
Abstract DNA polymerase, disc electrophoresis, template affinity Two sensitive methods are described for detection of DNA dependent DNA polymerase activities in polyacrylamide gels after their fractionation by micro-disc electrophoresis. One technique is based on the increase in fluorescence of the ethidium bromide complex with template polydeoxyribonucleotides brought about by the action of the polymerases. The sensitivity of the previously described technique has been enhanced. Another method, 14 fold as sensitive, uses radioactive precursors in the enzyme assay after electrophoretic separation; washing, slicing and counting allows to evaluate incorporation into acid insoluble polymer, re…