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PubMed2006

How much is there really? Why stereology is essential in lung morphometry.

Quantitative data on lung structure are essential to set up structure-function models for assessing the functional performance of the lung or to make statistically valid comparisons in experimental morphology, physiology, or pathology. The methods of choice for microscopy-based lung morphometry are those of stereology, the science of quantitative characterization of irregular three-dimensional objects on the basis of measurements made on two-dimensional sections. From a practical perspective, stereology is an assumption-free set of methods of unbiased sampling with geometric probes, based on a solid mathematical foundation. Here, we discuss the pitfalls of lung morphometry and present solutions, from specimen preparation to the sampling scheme in multiple stages, for obtaining unbiased estimates of morphometric parameters such as volumes, surfaces, lengths, and numbers. This is demonstrated on various examples. Stereological methods are accurate, efficient, simple, and transparent; the precision of the estimates depends on the size and distribution of the sample. For obtaining quantitative data on lung structure at all microscopic levels, state-of-the-art stereology is the gold standard.

Animals↗
PubMed2005

Geometrical model of the pulmonary root.

BACKGROUND AND AIM OF THE STUDY: The renaissance of the Ross procedure has attracted much attention to the clinical anatomy of the pulmonary valve. Within the reviewed literature which emphasizes the morphology of the pulmonary root, no detailed anatomy has been reported. The study aim was to describe the cardiosurgical-orientated anatomy of the pulmonary valve. METHODS: Morphometric measurements were made on 20 fixed normal pulmonary roots. The roots were fixed under diastolic pressure (5 mmHg) with closed leaflets. The distances between the commissures, and between the intervalvular triangles, were measured. The heights of the sinuses and of the intervalvular triangles were also defined. RESULTS: The mean (+/- SD) of each parameter was calculated. The distances of the right, left and anterior sinus commissures were approximately similar, as were the distances of the intervalvular triangles at the root base. The mean height of the left coronary sinus was maximal, followed by the right and anterior pulmonary sinuses. The left intervalvular triangle was highest, followed by the posterior and right intervalvular triangles. The difference between the height of the left sinus and right intervalvular triangle indicated a tilt angle of 16.26 degrees between the root base and sinotubular junction. CONCLUSION: Based on these measured parameters, a spatial geometrical model was constructed which clearly described the asymmetrical structure of the pulmonary root.

Adult↗
PubMed1994

Volume and surface area measurement of viable chondrocytes in situ using geometric modelling of serial confocal sections.

This study describes a technique for noninvasive determination of the surface area and volume of chondrocytes using the confocal scanning laser microscope, and the fundamental limitations associated with its application. Using geometric modelling principles, an isointensity surface contour was formed from a series of optical sections recorded with the confocal microscope. Using a combined surface- and volume-based algorithm, the surface area, volume and other morphometric descriptions were calculated from a polygonal description of the cell surface. The high image contrast required for repeatable identification of the cell border was achieved through the use of a fluorescent dye, which was excluded from cells by an intact membrane. Calibration results indicated that the theoretical modelling algorithm is relatively precise when applied to simulated convex (ellipsoidal) cells, with overall errors of less than 0.5% in surface area and volume measurements. When applied to low-noise, high-contrast volume data recorded on the confocal microscope, typical coefficients of variation of 2-4% were determined for length measurements, 2-5% for volume measurements and 3-6% for surface area measurements either for latex microspheres or for chondrocytes. While the precision of the method is comparable to standard histological techniques, its accuracy is difficult to assess, as systematic errors are unpredictable and may be introduced from several sources.

Calibration↗
PubMed2001

Modeling advection and diffusion of oxygen in complex vascular networks.

A realistic geometric model for the three-dimensional capillary network geometry is used as a framework for studying the transport and consumption of oxygen in cardiac tissue. The nontree-like capillary network conforms to the available morphometric statistics and is supplied by a single arterial source and drains into a pair of venular sinks. We explore steady-state oxygen transport and consumption in the tissue using a mathematical model which accounts for advection in the vascular network, nonlinear binding of dissolved oxygen to hemoglobin and myoglobin, passive diffusion of freely dissolved and protein-bound oxygen, and Michaelis-Menten consumption in the parenchymal tissue. The advection velocity field is found by solving the hemodynamic problem for flow throughout the network. The resulting system is described by a set of coupled nonlinear elliptic equations, which are solved using a finite-difference numerical approximation. We find that coupled advection and diffusion in the three-dimensional system enhance the dispersion of oxygen in the tissue compared to the predictions of simplified axially distributed models, and that no "lethal corner," or oxygen-deprived region occurs for physiologically reasonable values for flow and consumption. Concentrations of 0.5-1.0 mM myoglobin facilitate the transport of oxygen and thereby protect the tissue from hypoxia at levels near its P50, that is, when local oxygen consumption rates are close to those of delivery by flow and myoglobin-facilitated diffusion, a fairly narrow range.

Animals↗
PubMed2002

Three-dimensional reconstruction and fractal geometric analysis of serrated adenoma.

Serrated adenoma (SA) is a relatively newly defined entity of colorectal neoplasm first characterized by Longacre and Fenoglio-Preiser in 1990. This lesion is characterized by a complicated serrated edge of crypts. In this study, we performed three-dimensional (3-D) reconstruction, including 3-D distribution patterns of Ki-67-positive cells and fractal dimension of SA, in order to evaluate the nature of the complicated architecture, including its possible morphogenesis. We studied nine colonoscopic polypectomy specimens including three SAs, three tubular adenomas (TAs), and three hyperplastic polyps (HPs). Sixty serial tissue sections per case were stained alternately with hematoxylin and eosin (H&E) and Ki-67 immunostain. Each serial image was then digitized for 3-D computer analysis and the distribution pattern of Ki-67-positive cells was evaluated. Ki-67-immunostained sections were also subjected to 2-D quantitative morphometric study. In addition, the fractal dimensions of images from H&E-stained sections were examined using a box-counting method. Results of the 3-D reconstruction study demonstrated that glandular budding and branching were more frequent in SA than in TA or HP. These findings were confirmed quantitatively by the results of fractal geometric analysis of these polyps (fractal dimension:1.34 +/- 0.08 for SA, 1.23 +/- 0.07 for TA, and 1.28 +/- 0.12 for HP). Ki-67-positive cells in HP were localized mainly in the bottom of crypts and those in TA were diffusely distributed, while Ki-67-positive cells in SA were mainly aggregated in the depressed sites of serrated epithelia. These findings were also confirmed quantitatively using 2-D morphometry. These distribution patterns of the proliferative zone of SA are considered to contribute to the formation of the characteristic serrated epithelia and the complicated morphological appearance of SA.

Adenoma↗
PubMed1996

Morphometry in histopathology. An image analysis workstation for the pathology laboratory.

OBJECTIVE: To investigate the value of morphometry in comparative histologic analysis of diseases, fixing a set of parameters suitable for analysis and to create a general strategy for data storage and economical data management. STUDY DESIGN: To establish the following fundamental principles for morphometric measurements: (1) linear measurements to determine the distance between two points by using an eyepiece graticule with an engraved scale or alternatively with a ruler on a projected microscopic image or photograph; (2) Stereology based on geometric probability, allowing features in three dimensions to be measured from two-dimensional images; and (3) a computerized image processing and analysis system for image capture, storage and analysis using specialized software and hardware. RESULTS: Measurement procedures were demonstrated in different parameters using regenerative nodules of alcoholic cirrhosis as a model. Comparative analysis between primary biliary cirrhosis, alcoholic cirrhosis, posthepatitic cirrhosis and hepatocellular carcinoma showed the highest regenerative activity in posthepatitic cirrhosis. CONCLUSION: With current advances in computer technology, rapid, automatic measurements can be made from tissue sections and a variety of practical applications for the pathology laboratory, such as nuclear morphometry for comparison of different kinds of liver diseases, including classification of hepatocellular carcinoma.

Humans↗
PubMed2003

Effect of a fucose-rich polysaccharide preparation on the age-dependent evolution of the skin surface micro-relief.

It was demonstrated previously that the evaluation of the microdepressionary skin surface relief by semi-automated computerised morphometry enables the determination of several of its geometrical parameters, such as, the average number of polygons in a given microscopic field, and/or the average surface of the polygons. Using this procedure, it could be shown in a study on about 100 persons, males and females, aged from 6 months to 89 years that these parameters undergo age-related alterations. These alterations are faster at younger ages, slow down at middle ages and accelerate after 50-60 years again. Taken at a sun-protected site, the interior face of the forearm, close to the elbow, this test reflects the effect of chronological ageing of the skin surface micro-relief. In the present work we tested the effect of a preparation containing a fucose-rich polysaccharide as active principle on the microdepressionary skin surface micro-relief evaluated by a morphometric method, comparing results before treatment and after 4 weeks of treatment. We could demonstrate on 20 female volunteers, aged from 39 to 71 years, that after 4 weeks of treatment with the abovementioned preparation there was a significant improvement of the skin surface relief, as shown by the displacement of geometrical characteristics of 17 treated skins out of 20, towards a "younger" pattern, as for instance the increase of the average number of polygons in a given microscopic field. This improvement was less than 15% of the untreated value for two persons, and more than 15% for 15 women out of 20. The average improvement was 37.16%, and for the 15 persons showing more than 15% improvement, it was nearly 50%, corresponding to a decrease of apparent age by 10-15 years. These results suggest that a treatment with the fucose-rich polysaccharide preparation can slow down human skin ageing and even can reverse age-dependent skin alterations.

Adult↗
PubMed1991

Three-D muscular arrangement at the ureteropelvic junction and its changes in congenital hydronephrosis: a stereo-morphometric study.

Ureteral walls were obtained from twelve autopsies without urological diseases and from surgical material of twelve patients operated for congenital hydronephrosis. The specimens were submitted to computer-assisted analysis of 3-D muscular architecture at the ureteropelvic junction (UPJ). Serial histologic sections in parallel with the wall were prepared. A geometric model was introduced to simplify the muscular layer, replacing bundles with vectors of corresponding size and direction. The vector distribution visualized that normally, the ureteral muscles change their arrangement with age, from a circular pattern in neonates to an oblique mesh in adults. In addition, longitudinal muscles emerged at the age of two years in the subepithelial layer. In patients with congenital hydronephrosis, not only were such growth-related changes ambiguous or lacking, but there also were various abnormalities; segmental muscular hypoplasia, disarrangement of bundles or lack of longitudinal fibers. These were considered to closely correlate with the urinary obstruction in patients with this disease.

Adolescent↗
PubMed1977

Multiparameter geometric and densitometric analysis of the G0-G1 transition of WI-38 cells.

Automated image analyses were performed using Feulgen stained smears of WI-38 cells that were either confluent, or that had received a nutritional stimulus to proliferate 3 hr before collection. These experiments show that it is possible to observe changes in morphometric and densitometric parameters of nuclei that correlate with structural and functional differences in isolated chromatins from quiescent G0 and proliferation G1 cells that have been demonstrated by other means. Scatter plot analyses of the data indicated the presence of nuclear images from the stimulated G1 population that had the same deoxyribonucleic acid content as the confluent G0 cells, but had greater areas, perimeters and horizontal projections and smaller mean free paths, form factors, and average optical densities. Multiparameter cluster analysis permits, even minimally, an objective, model-independent identification of G0 from G1 cells that present an increased nuclear dispersion (i.e., lower average optical density) systematically accompanied by increased nuclear convolution (i.e., lower form factor), both compatible with the reported increase in available binding sites with respect to G0 cells.

Autoanalysis↗
PubMed2003

Measurement of the orbitofrontal cortex: a validation study of a new method.

The orbital frontal cortex (OFC) plays a critical role in the pathophysiology of several neuropsychiatric disorders. Few morphometric neuroimaging studies have examined the OFC using different methodologies and have reported discrepant values. Substantial variability in gyri and sulci across individuals as well as unclear landmarks underline the difficulties in obtaining accurate and reliable measurements. We propose a new geometrical method for measuring the OFC taking into account individual brain variability. The OFC was defined by using the intercommissural line and the inferior edge of the frontal lobe as the main landmarks. The medial and lateral subdivisions of OFC were also separately measured using the olfactory sulcus as the boundary to distinguish between them. After resampling and refitting, 10 scans were independently traced by two trained researchers using BRAINS software. Talairach coordinates were identified on each scan from the OFC and surrounding adjacent brain regions to assess the validity of this method. Brain regions were assigned using Talairach Daemon system. OFC volumes were comparable with those previously reported. Sensitivity and specificity for OFC gray matter were 87.6 and 84.8%, respectively. Intraclass coefficients (ICCs) for gray, white, and total OFC were 0.995, 0.994, and 0.997, respectively. ICCs for OFC medial and lateral subdivisions ranged between 0.996 and 0.998. This method appears to be a valid method for measuring the OFC with excellent reliability. This uncomplicated approach is easy to apply and has the potential to be a valuable alternative to the previously published methods.

Adult↗
PubMed2004

Early bone formation adjacent to rough and turned endosseous implant surfaces. An experimental study in the dog.

OBJECTIVE: To validate a proposed model (Berglundh et al. 2003) and to evaluate the rate and degree of osseointegration at turned (T) and sand blasted and acid etched (SLA) implant surfaces during early phases of healing. MATERIAL AND METHODS: The devices used for the study of early healing had a geometry that corresponded to that of a solid screw implant with either a SLA or a T surface configuration. A circumferential trough had been prepared within the thread region (intra-osseous portion) that established a geometrically well-defined wound chamber. Twenty Labrador dogs received totally 160 experimental devices to allow the evaluation of healing between 2 h and 12 weeks. Both ground and decalcified sections were prepared from mesial/distal and buccal/lingual device sites. Histometric and morphometric analyses of the ground sections and morphometric analysis of the tissue components in decalcified sections were performed. RESULTS: The ground sections provided an overview of the various phases of tissue formation, while the decalcified, thin sections enabled a more detailed study of events involved in bone tissue modeling and remodeling for both SLA and T surfaces. The initially empty wound chamber became occupied with a coagulum and a granulation tissue that was replaced by a provisional matrix. The process of bone formation started already during the first week. The newly formed bone present at the lateral border of the cut bony bed appeared to be continuous with the parent bone, but on the SLA surface woven bone was also found at a distance from the parent bone. Parallel-fibered and/or lamellar bone as well as bone marrow replaced this primary bone after 4 weeks. In the SLA chambers, more bone-to-device contact, more initial woven bone and earlier lamellar bone formation was found than in the T chambers. CONCLUSION: Osseointegration represents a dynamic process both during its establishment and its maintenance. While healing showed similar characteristics with resorptive and appositional events for both SLA and T surfaces, the rate and degree of osseointegration were superior for the SLA compared with the T chambers.

Animals↗
PubMed1999

Proliferation index and karyometric features of pancreatic intraductal proliferative lesions.

The increasing frequency and poor prognosis in pancreatic cancer prompt us to search for morphological lesions being a substrate for its development. Studies of autopsy and surgically resected material as well as recent molecular studies have proved that one of the possible pathways of pancreatic neoplasia is the intraepithelial proliferation--dysplasia--cancer sequence. In the present paper we studied the proliferative activity (Ki-67 index) in pancreatic intraepithelial proliferative lesions and its correlation with geometric features of cell nuclei as signs of increasing dysplasia. The studies were carried out in a group of 35 patients operated on for pancreatic cancer, chronic pancreatitis and other conditions not associated with the pancreas. We used immunohistochemical methods and basic morphometric parameters. The results of our studies indicate that the cell proliferative activity depends both on the type of epithelial proliferation and underlying pancreatic disease. The values of Ki-67 index are significantly different in low-grade proliferation (flat and papillary hyperplasia) and high-grade proliferation (atypical papillary hyperplasia and carcinoma in situ). A set of karyometric features correlates with Ki-67 index but there is no single feature which would have a diagnostic value.

Aged↗
PubMed1999

A three-dimensional model for arterial tree representation, generated by constrained constructive optimization.

The computational method of constrained constructive optimization (CCO) has been generalized in two important respects: (1) arterial model trees are now grown within a convex, three-dimensional piece of tissue and (2) terminal flow variability has been incorporated into the model to account for the heterogeneity of blood flow observed in real vascular beds. Although no direct information from topographic anatomy enters the model, computer-generated CCO trees closely resemble corrosion casts of real arterial trees, both on a visual basis and with regard to morphometric parameters. Terminal flow variability was found to induce transitions in the connective structure early in the trees' development. The present generalization of CCO offers--for the first time--the possibility to generate optimized arterial model trees in three dimensions, representing a realistic geometrical substrate for hemodynamic simulation studies. With the implementation of terminal flow variability the model is ready to simulate processes such as the adaptation of arterial diameters to changes in blood flow rate or the formation of different patterns of angiogenesis induced by changing needs of blood supply.

Algorithms↗
PubMed1984

Cholinergic responses in the human lung parenchymal strip: a structure-function correlation.

We have examined the contractile response of the human lung parenchymal strip to carbachol. Responses were highly variable both within and between subjects. In only 50 of the 72 strips studied could a measurable cumulative concentration-response relationship to carbachol be elicited (geometric mean EC50 3.1 x 10(-7) mol/l, 95% confidence limits 2.2, 4.2 x 10(-7) mol/l). In 22 strips, no such response could be elicited. Fifteen lung strips, including some which contracted to carbachol and others which did not, were subjected to morphometric analysis, using a point-counting procedure, to estimate volume proportions of tissue components of the lung strips. There was a significant correlation (r = 0.71, P less than 0.01) between maximal contraction of a strip to carbachol and its volume proportion of airways. These results suggest that the contractile response to carbachol in the human lung parenchymal strip originates from airway smooth muscle.

Aged↗
PubMed1992

Pattern of arborization of the motor nerve terminals in the fast and slow mammalian muscles.

A silver impregnation method and a morphometric approach were used to define differences existing in the motor nerve terminal branching pattern between a fast-twitch muscle (extensor digitorum longus) and a slow-twitch one (soleus) of the normal adult rat. Because no single measure can describe precisely all geometrical properties (ie both topology and metrics) of the nerve terminals, we evaluated morphologic parameters defining length and angular characteristics in the different terminal segments classified according to their centrifugal order. The main results indicate that the distal free-end segments in the extensor digitorum longus muscle are shorter and less divergent than in the soleus nerve terminals. The endings in the two muscles have different fractal dimensions. Findings are discussed in the context of the hypothetical mechanisms governing motor nerve terminal size and complexity.

Animals↗
PubMedDate not supplied

[Objective criteria for determining the degree of radiation injury of nerve cells in a cerebral syndrome].

The automatized morphometric technique was used to estimate the degree of injury to spinal nervous cells of rats exposed to 360 Gy radiation. It was shown that the compression coefficient and the volume of neuron nuclei considerably diminished as the CNS-syndrome developed, and the geometrical dimensions of the nervous cells themselves underwent phase changes.

Animals↗
PubMed2000

Biomechanical and morphological properties in rat large intestine.

Intestinal stress-strain distributions are important determinants of intestinal function and are determined by the mechanical properties of the intestinal wall, the physiological loading conditions and the zero-stress state of the intestine. In this study the distribution of morphometric measures, residual circumferential strains and stress-strain relationships along the rat large intestine were determined in vitro. Segments from four parts of the large intestine were excised, closed at both ends, and inflated with pressures up to 2kPa. The outer diameter and length were measured. The zero-stress state was obtained by cutting rings of large intestine radially. The geometric configuration at the zero-stress state is of fundamental importance because it is the basic state with respect to which the physical stresses and strains are defined. The outer and inner circumferences, wall thickness and opening angle were measured from digitised images. Subsequently, residual strain and stress-strain distributions were calculated. The wall thickness and wall thickness-to-circumference ratio increased in the distal direction. The opening angle varied between approximately 40 and approximately 125 degrees with the highest values in the beginning of proximal colon (F=1.739, P<0.05). The residual strain at the inner surface was negative indicating that the mucosa-submucosal layers of the large intestine in no-load state are in compression. The four segments showed stress-strain distributions that were exponential. All segments were stiffer in longitudinal direction than in the circumferential direction (P<0.05). The transverse colon seemed stiffest both in the circumferential and longitudinal directions. In conclusion, significant variations were found in morphometric and biomechanical properties along the large intestine. The circumferential residual strains and passive elastic properties must be taken into account in studies of physiological problems in which the stress and strain are important, e.g. large intestinal bolus transport function.

Animals↗
PubMed2005

A comparison of morphometric characteristics of sperm from fertile Bos taurus and Bos indicus bulls in Brazil.

The current work has as main objective the systematic investigation of sperm morphometric characteristics of fertile Bos taurus and Bos indicus bulls living in Brazil by using several traditional as well as more modern and advanced computer vision concepts and methodologies. Ten smears of B. taurus semen and ten smears of B. indicus semen have been evaluated. Sperm morphology was quantified in terms of the following morphological features: head area, perimeter, width, length, width:length ratio, ellipticity, shape factor, width of sperm basis, the three first Fourier values, symmetry and hydrodynamics. Morphometric differences have been observed between the sperm cell of B. taurus and B. indicus bulls. The sperm cells of Zebu bulls tend to be smaller and less elliptic, however without modifying hydrodynamic, side symmetry and width of sperm head base. These differences clearly indicate that the geometrical characterization of bull sperm cells should take into account morphological peculiarities that are specific to each subspecies. Another important contribution is the identification that morphological differences implied by bulls of different fertility, as characterized by other authors, were found to be less as compared with those obtained in the current study where highly fertile animals from the two subspecies were studied.

Animals↗