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PubMed2006

The determination of relative path length as a measure for tortuosity in compacts using image analysis.

Tortuosity is defined as the ratio of the actual path length from start to goal through the pores to the Euclidean distance (shortest linear distance). However, traditional methods to calculate tortuosity, such as the calculation of tortuosity out of the results from dissolution experiments, do not determine path length directly. In this paper we describe the application of image analysis for direct measurement of path length in order to obtain quantitative information on tortuosity. Several planes in cubic sodium chloride compacts, made by uni-axial compression, were imaged using scanning electron microscopy (SEM). In these images the average path length from top-to-bottom and from left-to-right was calculated, using the gray-weighted distance transform (GDT). As the direct, straight forward path was defined as having a length of unity, the relative path length could be taken as a quantitative measure for the tortuosity. The relative path length through the pores was found to be 1.4-1.6 and the relative path length over the grains was significantly lower (1.0-1.2). In most cases, the relative path length through the pores was significantly higher for the compacts containing small particles than for the compacts made of large particles. The relative path length was also dependent on the direction of the measurement, i.e. in the direction of compression of the compact or perpendicular to it. This indicates anisotropy in structure with the pores preferentially oriented in the direction of compression. It was concluded that this method is a valuable tool for the determination of path length in compacts as a direct measure for tortuosity. It can also be used to evaluate the anisotropy in structure.

Image Processing, Computer-Assisted↗
PubMed1997

Nuclear image analysis of p53-positive and -negative cells in breast carcinoma.

OBJECTIVE: To detect differences in nuclear morphology in breast carcinoma cells with different p53 expression. STUDY DESIGN: Immunohistochemical reactions were performed on paraffin sections from 88 breast cancers with the monoclonal antibody DO-1. By means of an image cytometry workstation, 500 nuclei were localized and categorized in an immunohistochemical staining scoring system in each case. After destaining and Feulgen staining, the nuclei were relocated and measured by means of the workstation. RESULTS: P53-positive nuclei showed greater irregularity of the chromatin pattern and stronger granularity of the chromatin. There were also differences in the chromatin texture and nuclear shape between tumors different in their p53 expression. The p53-negative nuclear population from the p53-positive tumors and the whole nuclear population of the p53-negative tumors were morphologically different, also. CONCLUSION: Nuclear image analysis of immunohistochemically characterized cells allows further insight into the relationship of structure and function in malignant tumor cells.

Adult↗
PubMed1993

Endothelial cell adhesion in real time. Measurements in vitro by tandem scanning confocal image analysis.

Real time measurements of cell-substratum adhesion in endothelial cells were obtained by tandem scanning confocal microscopy of sites of focal contact (focal adhesions) at the abluminal cell surface. Focal contact sites were sharply defined (low radiance levels) in the living cell such that the images could be enhanced, digitized, and isolated from other cellular detail. Sites of focal contact are the principal determinant of cell-substratum adhesion. Measurements of (a) the focal contact area and (b) the closeness of contact (inverse radiance) were used to nominally define the adhesion of a single cell or field of cells, and to record spontaneous and induced changes of cell adhesion in real time. The topography of focal contacts was estimated by calculating separation distances from radiance values using a calibration technique based on interference ring optics. While slightly closer contact was noted between the cell membrane and substratum at or near the center of each focal contact, separation distances throughout the adhesion regions were always < 50 nm. Subtraction of consecutive images revealed continuous spontaneous remodeling of individual focal adhesions in unperturbed cells during periods of < 1 min. Despite extensive remodeling of focal contact sites, however, cell adhesion calculated for an entire cell over extended periods varied by < 10%. When cytoskeletal stability was impaired by exposure to cytochalasin or when cells were exposed to proteolytic enzyme, endothelial adhesion declined rapidly. Such changes were recorded at the level of single cells, groups of cells, and at single focal adhesions. In both unperturbed and manipulated cells, the dynamics of remodeling and cell adhesion characteristics varied greatly between individual sites within the same cell; disappearance of existing sites and appearance of new ones often occurred within minutes while adjacent sites underwent minimal remodelling. Tandem scanning confocal microscopy image analysis of living cells in real time provides repetitive spatial, temporal, and quantitative information about cell adhesion. Such an approach should allow more precise quantitative analyses to be made of the interactions between extracellular matrix, adhesion proteins, integrins, and the cytoskeleton in the living cell.

Actins↗
PubMed1989

Vascular architecture of melanocytic skin tumors. A quantitative immunohistochemical study using automated image analysis.

The present study examines the distribution of blood vessels in melanocytic skin tumors. Fresh frozen sections of 11 cases each of benign nevocellular nevus, primary malignant melanoma and metastatic malignant melanoma were stained with the endothelium-specific monoclonal antibody BMA 120 and evaluated by an automated image analysis system. Additionally, the proliferative activity was assessed in parallel sections using Ki 67 monoclonal antibody. There were only slight differences between the diagnostic groups as to the vascular distribution in the tumor center, but there were remarkable differences in the connective tissue at the base of the lesions: The area occupied by small vessels (minimum diameter less than 20 microns) was 0.3 +/- 0.05% in benign nevi, 0.6 +/- 0.05% in primary malignant melanoma, and 1.2 +/- 0.10% in metastatic malignant melanoma (U-test: p less than or equal to 0.05). The proliferative activity within each lesion showed a strong positive correlation with the number of small vessels at the base of the tumor (linear regression analysis: r = 0.86; p less than or equal to 0.0001). The findings demonstrate that neovascularization in malignant melanocytic tumors takes place predominantly in the surrounding host tissue and is closely related to the proliferative activity.

Adolescent↗
PubMed2006

Application of Photoshop and Scion Image analysis to quantification of signals in histochemistry, immunocytochemistry and hybridocytochemistry.

OBJECTIVE: To describe a simple method to achieve the differential selection and subsequent quantification of the strength signal using only one section. STUDY DESIGN: Several methods for performing quantitative histochemistry, immunocytochemistry or hybridocytochemistry, without use of specific commercial image analysis systems, rely on pixel-counting algorithms, which do not provide information on the amount of chromogen present in the section. Other techniques use complex algorithms to calculate the cumulative signal strength using two consecutive sections. To separate the chromogen signal we used the "Color range" option of the Adobe Photoshop program, which provides a specific file for a particular chromogen selection that could be applied on similar sections. The measurement of the chromogen signal strength of the specific staining is achieved with the Scion Image software program. CONCLUSION: The method described in this paper can also be applied to simultaneous detection of different signals on the same section or different parameters (area of particles, number of particles, etc.) when the "Analyze particles" tool of the Scion program is used.

Animals↗
PubMed1994

Echographic evaluation with image analysis of normal skin: variations according to age and sex.

In order to identify and characterize the sonographic variations between different age groups, 48 subjects, 24 aged 27-30, and 24 over 60, were studied with a 20-MHz B scanner on six skin sites. Images were evaluated by the instrument's standard programme and by a new image analysis software package enabling the characterization of steady structures or transitory functional aspects of skin reactions, by highlighting areas in which the echo amplitudes are included within selected values, and by calculating their extension. Three bands were selected as intervals of interest, respectively, highlighting hyporeflecting parts of the dermis, tissue reflecting with intermediate amplitude values and hyperreflecting epidermis and dermis. This method was employed to assess skin thickness, demonstrating its decrease in elderly skin, to characterize and quantify the hypoechogenic subepidermal band appearing in the elderly at volar and dorsal forearm skin, and to evaluate echogenicity of the upper and lower dermis. Our data show that there is a great regional variation in the behaviour of ultrasound reflection of elderly skin in respect to the skin of young subjects. However, a general trend can be identified, consisting in a shift from low-intensity ultrasound echoes, characteristic in the dermis of young subjects, to intermediate or high reflection amplitudes, which are more frequent in elderly skin. Thus, the echographic method provides two parameters for the evaluation of skin aging.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1987

Quantitative image analysis of the density and pattern of adrenergic innervation of blood vessels of rat spinal cord.

The density and pattern of the noradrenergic innervation of the main extramedullary blood vessels of the rat spinal cord was studied using combined glyoxylic acid histofluorescence and quantitative image analysis techniques. The anterior spinal artery has a perivascular plexus of fine noradrenergic nerves rich in varicosities; the central artery has nerve fibers of various sizes; and the posterior spinal vein has a limited plexus of noradrenergic nerve fibers. The possible significance of the noradrenergic innervation of extramedullary spinal cord blood vessels is discussed.

Animals↗
PubMed1990

Non-specific cholinesterase activity in mouse spinal ganglia. The usefulness of histochemical study and image analysis for simple characterization of neuron subclasses.

Non-specific cholinesterase (ChE) activity was studied histochemically at light and electron microscopical levels in dorsal root ganglia (DRG) of adult mice. The reaction staining and diameter of neuron cells perykaria were measured by using an image analysis system. The methodological approach enable to distinguish 8 subclasses of primary sensory neurons. The proportion of individual subclasses was mapping in three subsequent cervical, thoracal and lumbar DRG. The populations of small-sized neurons increased towards lumbar level similarly as medium and small neurons exhibiting high ChE reactivity. The variations in ChE-containing neurons among DRG from different area may reflect differences in modality-specific primary sensory neurons at each spinal cord level. In addition, the effect of 3 week sciatic nerve transection on the percentage of the subclasses in L4-L6 DRG has been investigated. The number of large neurons was reduced and a decrease of ChE reactivity in medium-size neurons was found in DRG on the operated side. Thus, the present results demonstrate a selective affectation of primary sensory neurons in mouse DRG by the peripheral nerve transection. Different amounts of the reaction product corresponding with ChE activity were found in the nuclear envelope and the cisternae of rough endoplasmic reticulum.

Animals↗
PubMed1991

DNA ploidy by image analysis of individual foci of prostate cancer: a preliminary report.

The malignant potential of an individual focus of prostate cancer is difficult to determine. The established pathological features associated with malignant behavior include tumor volume, grade, and invasiveness (local extension or metastasis). We used nuclear image analysis to determine the DNA ploidy value of each cancer in a series of 30 radical prostatectomy specimens from patients with early stage prostate cancer in order to further explore the malignant potential of each separate focus of cancer. The volume, grade, invasiveness (extracapsular extension or seminal vesicle invasion), and zone of origin of each of the 63 separate cancers were determined. The DNA ploidy histogram of 200 cancer cells was compared with 50 normal epithelial nuclei on the same Feulgen-stained tissue sections. Sixty % of the cancers were diploid, and 40% were nondiploid. Ploidy correlated with volume and grade. All cancers less than 0.02 cm3 were diploid; 26% of foci 0.02 to 2.0 cm3 and 82% of foci greater than 2.0 cm3 were nondiploid. There were 16 cancers of transition zone origin ranging in size from 0.02 to 12.1 cm3 and only one (7.3 cm3) was nondiploid. There were 47 cancers of peripheral zone origin (range, 0.01 to 18.98) and 24 (51%) were nondiploid. Eight of the 24 nondiploid cancers were small (less than 1.0 cm3), and two were only 0.03 cm3. We conclude that some very small prostate cancers are nondiploid and that progression of prostate cancer is not a function of volume alone, whereby tumors only acquire full malignant potential at large volumes. Cancers of peripheral zone origin acquire a nondiploid cell population at a smaller volume than do cancers of transition zone origin, further supporting a fundamental difference between cancers arising in these zones.

Cell Differentiation↗
PubMed1994

Assessment of the conventional criteria of semen quality by computer-assisted image analysis: evaluation of the Hamilton-Thorn motility analyser in the context of a service andrology laboratory.

A comparative assessment of the conventional criteria of semen quality (sperm concentration, motility and morphology) was undertaken by standard laboratory techniques and by means of a computer-assisted image analysis system (the Hamilton-Thorn HTM-S 2030) in an open prospective study, in the context of a service andrology laboratory. A total of 1435 semen samples submitted by couples in the course of routine infertility investigations were examined by both methods, and the results compared. It was observed that the method did not provide comparable data on semen quality, either in respect of sperm concentration or graded motility, while the morphometric data generated by the HTM-S did not appear to be related to conventional morphology assessment. The clinical value of such systems in the assessment of the classical determinants of semen quality requires formal assessment in properly conducted large scale prospective studies.

Evaluation Studies as Topic↗
PubMed2000

Intracellular pH determination of pristinamycin-producing Streptomyces pristinaespiralis by image analysis.

Intracellular pH (pH(i)) is an essential parameter in the regulation of intracellular processes. Thus, its measurement might provide clues regarding the physiological state of cells cultivated in vitro. pH(i) of the filamentous, pristinamycin-producing Streptomyces pristinaespiralis was determined by epifluorescence microscopy and image analysis using the pH-sensitive fluorescent probe BCECF-AM [2', 7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein, acetoxymethyl ester]. Staining cell culture samples (OD(660)=1) of S. pristinaespiralis with 20 microM BCECF at 28 degrees C for 30 min yielded a green/red fluorescence ratio (R:(527/600)) that correlated with the pH(i) of the cells for values ranging from 6.5 to 8.5. When S. pristinaespiralis was cultivated in pristinamycin-producing conditions (in batch mode, with a constant external pH of 6.8), the measured pH(i) varied between 6.3 and 8.7. In fact, pH(i) correlated with the excretion of pristinamycins and glucose consumption during the production process.

Anti-Bacterial Agents↗
PubMedDate not supplied

Morphometric image analysis of neuropil threads in Alzheimer's disease.

Neuropil threads were quantitated in the neuropil (excluding senile plaques) of the superior frontal gyrus of 6 late stage patients with Alzheimer's disease (AD) and 6 age-matched control subjects using tau immunocytochemistry and computerized morphometric image analysis. The mean percent of the area of the neuropil occupied by neuropil threads was 10.6 for AD and 0.19 for controls (p < 1 x 10(-10)). The mean length of neuropil threads in AD was 21.9 mu compared with 19.7 mu for controls (p < 1 x 10(-10)). The mean area of neuropil threads was 25.3 mu 2 for AD and 21.3 mu 2 for controls (p < 1 x 10(-10)). In AD, the threads were most prominent in mid cortex (lamina 2 and 3) and least prominent in the lower cortex (lamina 5 and 6). Neuropil threads appear to lead to severe disorganization of intracortical and corticocortical connectivity and probably play a role in the cognitive failure in AD.

Aged↗
PubMed1993

Image analysis of dendritic cells in the human fetal thymus.

The distribution and evolution of thymic dendritic cells (DC) were studied during human ontogeny. Immunochemical techniques were used to detect S100 protein-positive cells on fetal thymus sections, at different post-fecundation (PF) ages; an image analysis of these positive cells was then carried out. Variations in the percentage of these cells in the medulla were determined according to age: the higher percentages were seen at 12 and 16 weeks PF. Dendritic cells were present at an early stage in the thymic rudiment (7 weeks PF), a finding consistent with an origin of these cells in the fetal liver, and with the possible existence of local attraction and/or maturation factors. The expression of the CD54 adhesion molecule revealed the existence of particular interactions between DC and lymphocytes in the medullary area, and at the cortico-medullar junction. Diffuse CD11a (LFA-1) expression on lymphocytes was consistent throughout gestation. The monocyte/macrophage markers (CD11b, CD14) and the reaction of non-specific esterases showed that the distribution pattern of these cells differed from the DC pattern. These ontogenic data are related to the significant role played by DC throughout the different stages of thymopoiesis.

Antigens, CD↗
PubMed2006

RetCam image analysis of optic disc morphology in premature infants and its relation to ischaemic brain injury.

AIMS: To assess optic disc characteristics in premature infants with and without ischaemic brain injury and to evaluate the role of optic disc morphology in dating the injury. METHODS: RetCam fundal images, cranial ultrasounds and magnetic resonance imaging (MRI) of 109 premature infants were analysed. The study cohort was divided into subgroups depending on the presence or absence of periventricular leucomalacia (PVL) and intraventricular haemorrhage (IVH). The control group consisted of infants with normal neuroimaging at term and 2 years of age. Using the image analysis software of the RetCam, optic disc diameter (ODD), optic disc area (ODA), and optic cup area (OCA) were measured at 33-34 weeks gestational age. As serial cranial ultrasonography had been performed, it was possible to date the brain injury in those infants with periventricular white matter (PVWM) damage. RESULTS: Although there was a trend towards reducing ODD, ODA, and OCA with increasing severity of IVH, only the IVH 4 group differed significantly from the controls for these parameters (p = 0.002, p = 0.02, and p = 0.04, respectively). 44.4% of infants with grade 4 IVH had small discs. Only one patient had a large cup in a normal sized disc; this patient had IVH 4. In patients with PVWM damage, the median time of insult was 27 weeks in those with small discs and 28 weeks in those with normal discs. This difference was not significant (p = 0.23). CONCLUSIONS: Premature infants with IVH 4 have an increased incidence of optic nerve hypoplasia. We found no association between disc morphology and timing of brain injury.

Brain Ischemia↗
PubMed2004

Structure of the rotor of the bacterial flagellar motor revealed by electron cryomicroscopy and single-particle image analysis.

The FliF ring is the base for self-assembly of the bacterial flagellum and the FliF/FliG ring complex is the core of the rotor of the flagellar motor. We report the structures of these two ring complexes obtained by electron cryomicroscopy and single-particle image analysis at 22A and 25A resolution, respectively. Direct comparison of these structures with the flagellar basal body made by superimposing the density maps on the central section reveals many interesting features, such as how the mechanically stable connection between the ring and the rod is formed, how directly FliF domains are involved in the near axial density of the basal body forming the proximal end of the central channel for a potential gating mechanism, some indication of flexibility in the connection of FliF and FliG, and structural and functional similarities to the head-to-tail connectors of bacteriophages.

Bacteria↗
PubMed2000

Sensitivity of Seescan TV image analysis in discriminating between normal, dysplastic and malignant oral smears.

OBJECTIVE: Smears from premalignant and malignant lesions may contain large proportions of normal cells together with atypical cells; that could reduce the sensitivity of cytologic diagnosis. The present study assessed the performance of the Seescan TV image analysis system (TVIAS) in distinguishing between normal, premalignant and malignant oral smears. The sensitivity of Seescan TVIAS was tested using both white and monochromatic light. STUDY DESIGN: Nuclear area (NA) and corrected integrated optical density (IOD) of 50 Feulgen-stained nuclei were measured in smears collected from normal oral mucosa (n = 6), lesions displaying epithelial dysplasia (n = 5) and invasive squamous cell carcinoma (n = 5) using a Seescan TVIAS with both white and monochromatic light. RESULTS: There was a significant increase (P < .001) in mean IOD for nuclei in smears from dysplastic lesions and carcinomas as compared with normal smears. For smears from carcinomas, the mean NA was significantly elevated as compared with dysplastic (P < .001) and normal smears (P < .01). Mean NA for dysplastic smears was significantly reduced as compared with normal smears. While all smears from premalignant and malignant lesions contained mostly normal nuclei, a significant proportion of abnormal nuclei was identified in each smear. CONCLUSION: Although oral smears contain large amounts of normal cells, the Seescan TVIAS could successfully identify dysplastic and malignant cells on the basis of both IOD and NA values with or without the use of a monochromatic filter.

Carcinoma, Squamous Cell↗
PubMed1990

Quantitative ultrastructural immunocytochemistry using a computerized image analysis system.

Secretory granules in human pituitary adenoma cells have been examined indirectly for hormone epitopes by immunogold labelling of resin-embedded ultrathin sections. The specific binding of different immunoglobulin-gold complexes to the antigrowth hormone antibodies over the secretory granules was measured using a computerized image analysis system. This facilitated the assessment of the preferential binding to the target granules of gold particles with three different average particle diameters (Au7, Au11, Au17). The time of pretreatment of sections with H2O2 or a buffer was found to influence the staining considerably. The scanning electron microscopic findings of protruded secretory granules with a mountain-like surface might be relevant to the uneven distribution of immunolabels seen over the secretory granules in the adenohypophysis.

Adenoma↗
PubMed1994

Quantitative image analysis study of the cerebral vasodilatory activity of nicardipine in spontaneously hypertensive rats.

The effect of the Ca2+ channel blocker nicardipine on the circle of Willis and the different sized pial arteries was assessed in 20-week-old spontaneously hypertensive rats (SHR) using quantitative image analysis techniques. Normotensive Wistar Kyoto (WKY) rats were also used as a normotensive reference group. In SHR a significant increase of systolic blood pressure (SBP) is noticeable in comparison with WKY rats. The media-to-lumen ratio was increased in the circle of Willis arteries, large sized (diameter > than 150 microns), medium sized (diameter between 150 and 50 microns) and small sized (diameter < than 50 microns), pial artery branches. An increase in the thickness of the tunica media and a luminal narrowing was also seen in medium and small sized pial arteries of SHR in comparison with WKY rats. Treatment with an oral dose of 10 mg/Kg of nicardipine 3 h before the sacrifice significantly reduced SBP in SHR. The drug was without effect on circle of Willis and on large sized pial arteries. Moreover, treatment with nicardipine reduced the thickness of the tunica media, the media-to-lumen ratio and increased the luminal area in medium and small sized pial artery branches. These findings show that treatment of SHR with nicardipine significantly reduces SBP and causes a moderate vasodilatation of arteries regulating cerebrovascular resistance. This property may be useful in avoiding generalized or exaggerated cerebrovascular dilatation which could be accompanied by impaired brain perfusion in hypertension.

Animals↗