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Results for “morphometry”

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At least 181 records · Page 10Linked to original sources

PubMed1990

Ultrastructural comparative study on endometrium of Chinese women using intrauterine devices of stainless steel ring, copper T220, and releasing levonorgestrel: morphometry of microvessels.

An electron microscopic morphometric study was performed for three kinds of IUDs, the stainless steel ring (SS), the copper T220 (TCu) and the WHO levonorgestrel IUD (LNG), for comparison of their effects on microvessels of the endometrium of women wearing the devices. The morphometry of plasmolemmal vesicles (PV) of the endothelial cell as well as the contracted and degenerated endothelial cell were undertaken. The results showed that all three IUDs led to significant changes in blood vessels, i.e., a higher percentage of contracted and degenerated cells than in the control group (p less than 0.01), and an increase in PV after insertion of the devices (p less than 0.01). The TCu caused more contracted endothelial cells than the SS (p less than 0.01) and the LNG (p less than 0.05). The levonorgestrel-releasing IUD resulted in a higher increase of PV than the SS and the TCu. For the differences between bleeding and non-bleeding groups, only the TCu showed a higher percentage of contracted cells (p less than 0.05).

Adult↗

PubMed1992

Type-specific changes in fiber morphometry following denervation of canine extraocular muscle.

To investigate the changes that occur in extraocular muscle morphometry following denervation, 12 beagles were subjected to intracranial section of the left oculomotor nerve. The inferior and medial rectus muscles were removed from both orbits of four dogs killed at each 4-week postoperative interval. Fiber diameters and fiber-type ratios of denervated muscles were compared with those from paired muscles in the normal orbit. We found significant, persistent atrophy of the singly innervated fibers in both the global and orbital layers of denervated extraocular muscle. The multiinnervated fibers were predominantly spared from denervation atrophy. We also found a significant increase in the proportion of multiinnervated fibers in the orbital layer only. These results suggest a relative neurotrophic independence of multiinnervated fibers in extraocular muscle.

Animals↗

PubMed1977

Computerized image recognition for morphometry of nerve attribute of shape of sampled transverse sections of myelinated fibers which best estimates their average diameter.

A computerized image recognition method was used to measure various attributes of shape of cross-sections of myelinated nerve fibers. Measurements were made at intervals over 1/2 internode of each fiber on 20 fibers from each of 4 sural nerves from rats. Diameters were computed in 6 different ways from the computer measurements and compared for bias, precision, and accuracy between sections and to the diameter of an idealized cylinder reconstructed for each fiber from multiple actual cross sections. The diameter computed from cross-sectional areas of transversely sectioned myelinated fibers, converted into a circle, showed the highest precision, greatest accuracy and least bias. Fibers were classified by shape and the frequency was determined in defined regions (I1 = paranodal, I3= nuclear and I2=region between I1 and I3) of the 1/2 internode. A crenated shape is highly characteristic of the I1 region. The boomerang shape was found most frequently in I3 whereas the circular shape was found most frequently in I2. Epileptical and boomerang shapes of myelinated fibers within fascicles which have been orientated carefully to obtain transverse sections, are not due to obliquity of section. Therefore, using the minor axis to determine the diameter of such profiles, as we had done previously in our laboratory, is in error. We conclude from these studies, that in carefully orientated transverse sections of nerve trucks, the diameter calculated from measurement of area converted to a circular shape is the best among the various estimates of myelinated fiber diameter and is the most suitable one for use in computerized image recognition systems for nerve morphometry. It seems reasonable to extrapolate this general conclusion to myelinated fibers of man.

Animals↗

PubMed1992

Ultrastructural morphometry of membrane-bound intracytoplasmic collagen fibrils in tendon fibroblasts exposed to He:Ne laser beam.

Collagen fibrils are not found in fibroblast cytoplasm except in certain pathological conditions or in the presence of drugs and other agents that accelerate collagen turnover. Because low energy laser photostimulation is both a non-pathogenic and non-chemical accelerator of collagen synthesis, its effects were studied on four groups of calcaneal tendons from 18 rabbits (1) to test the hypothesis that vacuolar fibrils are not produced exclusively by diseases and chemical agents, and (2) to compare the morphometry of matrical and vacuolar fibrils. The right calcaneal tendons of nine rabbits were surgically tenotomized and repaired; six of these were transcutaneously irradiated with He:Ne laser everyday. The right calcaneal tendon of six of the remaining nine rabbits were similarly irradiated with laser, but without prior tenotomy and repair. 21 days later, all tendons were fixed in situ and processed for electron microscopy. Fibril-bearing vacuoles were found only in fibroblasts of tenotomized laser-irradiated tendons. Similar vacuoles were not seen in non-tenotomized laser-irradiated tendons nor in non-irradiated tendons whether tenotomized or not. Mann-Whitney U tests revealed no statistically significant differences in the cross-sectional areas or diameters of matrical and vacuolar fibrils. These findings suggest (a) that matrical and vacuolar fibrils have a common origin, and (b) that vacuolar fibrils can be induced by a non-pathologic, non-chemical accelerator of collagen synthesis.

Animals↗

PubMed1984

Pulmonary toxicity associated with fly ash from fluidized bed coal combustion. II. Cellular morphometry of distal lung following a single intratracheal instillation.

Fly ash from an experimental fluidized bed coal combustor (FBC) was intratracheally instilled (once) into male Syrian golden hamsters at concentrations of 0 (control), 3, 10, 30, and 100 mg/animal. Thirty days postadministration, lungs were fixed by intratracheal perfusion, and tissues were processed for electron microscopic evaluation. Standard point count morphometry was used to analyze distal lung structures. Significant differences were found in volume density of noncellular interstitial space, with this compartment being increased in a dose-dependent manner. Volume density, numerical density, and average cellular volume of distal lung cells revealed no significant differences between treated and control animals. In addition, diffusion capacity and air-blood barrier thickness were not significantly altered in treated animals. The absence of cellular change at 30 days postexposure suggests a residual effect on noncellular interstitium, which may implicate fibrosis.

Animals↗

PubMed1990

Interactive morphometry of normal and hyperplastic peritoneal mesothelial cells and dysplastic and malignant ovarian cells.

This study used computerized interactive morphometry to evaluate the differential characteristics of mesothelial normal cells, mesothelial hyperplastic cells, and carcinomatous cells, and also compared hyperplastic mesothelial cells with ovarian dysplastic cells from a previous study. The procedure included extraction of multiple descriptors of the nuclear profile: perimeter length, area, longest chord, circularity factors, standard deviations of these characteristics, and a 10-bin size distribution table of the nuclear area. The final classification is achieved by stepwise discriminant analysis of these variables. The analysis classified all cases correctly with high posterior probabilities.

Cystadenocarcinoma↗

PubMed1987

Quantitative morphometry measurements of transitional cell bladder cancer nuclei as indicator of tumor aggression.

Superficial transitional cell carcinomas of the urinary bladder in 30 patients were studied by quantitative morphometry of the initial and subsequent tumor occurrences. Nuclear histograms were constructed and demonstrated narrow base and single modal peak in 9 of 10 patients not exhibiting tumor recurrence or invasion. In contrast, broad-based multimodal nuclear histograms were present in 15 of 20 patients in whom tumor invasion of carcinoma in situ subsequently developed. Nuclear histograms may provide an accurate means of determining invasive/recurrence potential of transitional cell carcinoma.

Carcinoma, Transitional Cell↗

PubMed1992

Nuclear morphometry in prognosis of renal adenocarcinoma.

Nuclear morphometry was carried out on 95 parenchymatous adenocarcinomas of the kidney treated by radical nephrectomy and hilar lymphadenectomy and followed up for at least five years. The study assessed nuclear area, nuclear perimeter, major diameter, nucleolar area, nuclear shape factor, and nuclear size. There was a significant statistical correlation between survival and the morphometric parameters and between the parameters themselves except for nuclear shape factor. The multiple regression proved that nuclear area is the factor which shows the greatest statistical significance for prognosis. Taking a mean nuclear area of 35 microns 2 allowed two prognostic groups to be established regardless of stage, with those below the threshold having a good prognosis and those above it having a poor prognosis: 96.7 percent of patients with a good prognosis survived after five years (60 months) compared with 17.2 percent of those with a poor prognosis.

Actuarial Analysis↗

PubMedDate not supplied

Methodological problems in placental morphometry: apologia for the use of stereology based on sound sampling practice.

Several problem areas in morphometry of human and animal placentae are reviewed. Attention is given to methods of tissue processing (handling, mode of fixation, embedding, shrinkage) and sampling (of organs, tissue blocks, sections, micrographs). Principal sources of bias and sampling variability are identified and the crucial importance of randomized sampling is emphasized. Methods for obtaining structural quantities from sections are compared. The case is made for estimating absolute values (volumes, surface areas, lengths, numbers, thicknesses) using stereological principles rather than relying on planar data (profile areas, perimeter lengths, numbers, apparent thicknesses). Absolute values may be obtained simply and efficiently without resort to expensive measuring devices. Finally, morphological descriptors suitable for correlating with functional data or for comparing normal and diseased organs are surveyed.

Delivery, Obstetric↗

PubMed1991

A useful programme in BASIC for axonal morphometry with introduction of new cytoskeletal parameters.

Interest in the structure of axons and quantification of their components has been growing over the last years. However, the existing literature contains few reports of available computer programmes to facilitate such studies. This paper presents a fully comprehensive BASIC programme for the morphometric analysis of electron micrographs of cross-sectional nerve fibres. From drawings of fibre and axonal contours and dots of the microtubules and neurofilaments, the programme calculates the following parameters: area, diameter and form factor of the fibres and axons, number and density of microtubules and neurofilaments, proportion between microtubules and neurofilaments (R-proportion), myelin thickness and the diameter of the axon relative to its sheath (g-ratio). The programme also introduces three new parameters to analyse the degree of uniformity of microtubule and neurofilament distribution: distances between microtubules and between neurofilaments, equilateral index and cytoskeletal intermingling index. The programme is written in Microsoft BASIC Interpreter for Apple Macintosh (Microsoft Corporation) but can be used on other computers. Although the programme has been tested on adult rat optic nerve fibres, it can be used for different projects concerning axonal morphometry.

Animals↗

PubMed1989

Intrinsic and extrinsic factors collaborate to generate driving forces for neural tube formation in the chick: a study using morphometry and computerized three-dimensional reconstruction.

The formation of the neural tube, the rudiment of the entire central nervous system, is one of the earliest morphogenetic movements. The origin of the driving forces for this process remains uncertain, but recent studies suggest the involvement of both intrinsic and extrinsic factors. In the present study, we have used morphometry, analysis of stereopair photographs of whole embryos, and computerized three-dimensional reconstruction to investigate the factors which constitute the bulk of the driving forces for neural tube formation in the developing midbrain of Hamburger and Hamilton stages 5-9 chick embryos. Results support the notion that neural tube formation is driven by a coordinated interplay of intrinsic and extrinsic forces. Initial bending of the neural plate along the midline of the embryo and uplifting of the neural folds is accomplished primarily through the combined action of intrinsic forces (resulting from apical constriction of neuroepithelial cells) and extrinsic forces (mostly a passive consequence of head-fold formation). However, once in the uplifted position, curling over of neural folds and closure of the neural tube is driven largely by apical constriction-mediated (intrinsic) forces that are generated by cells in the midlateral walls of the forming neural tube.

Animals↗

PubMed1995

DATAPLOT: a graphical display package for bacterial morphometry and fluorimetry data.

A microbiological image processing system has been developed, which is used to determine both morphometry and fluorimetry data on (mainly faecal) bacteria. A special program for display of these data has been developed for this system. Besides probability density estimates of any one or two parameters and scatter plots of any two or three parameters in the distribution, it can generate scatter plots using the actual bacterial shapes, rather than arbitrary symbols. A particularly powerful feature of the program is the possibility to overlay a contour plot of the probability density distribution of the bacteria in parameter space, with a scatter plot of the actual bacterial shapes involved. In this paper, the program's organization, options, and the algorithms used are discussed.

Algorithms↗

PubMed1988

Vertebral morphometry in diagnosis of spinal fractures.

Vertebral morphometry was performed on lateral thoracic and lumbar radiographs of 153 women with a preliminary diagnosis of spinal osteoporosis. Measurements included anterior and posterior vertebral height, width, area, wedge angle, percent reduction of anterior to posterior height (PRH) and percent difference in anterior height between adjoining vertebrae (PDAH). A vertebral fracture was identified if any of the measurements which control for interindividual variation in vertebral size (wedge angle, PRH, PDAH) were below the normal range. Among individuals with mild osteoporosis (0-2 fractures) PDAH identified 86% of the fractures and 95% of the individuals with fractures. Other measurements identified less than 71% of the fractures and less than 80% of the individuals with fractures. Although the results reflect a relative rather than a true sensitivity it appears that PDAH is the better diagnostic measurement for fractures in the earlier stages of spinal osteoporosis.

Aged↗

PubMed1984

Ready evaluation of lung alveolar toxic damage with histological sections morphometry.

In this experiment we aimed at developping a method of ready evaluation of lung alveolar toxic damage using morphometric measurements. Swiss-Webster mice were treated with different doses of diquat (i.p.) and the left lung was fixed at 0, 3, and 5 days after treatment. The technique of morphometry of histological sections embedded in glycol methacrylate (GMA) was used to quantify possible modifications of alveolar cells. Quantitative evaluation includes: alveolar macrophages, polymorphonuclear cells, type II and intermediate pneumocytes. The results indicate a lung dose-dependent response, observed in both inflammatory and epithelial regeneration components of the alveolar primary reaction. This method could be used to readily evaluate the pulmonary toxic potential of any substance.

Animals↗

PubMed1987

Changes in the distribution of extracellular matrix vesicles during healing of rat tibial bone (computerized morphometry and electron microscopy).

A study of the distribution of extracellular matrix vesicles during the first 3 weeks of healing of adult rat tibial bone was performed by transmission electron microscopy in combination with computerized morphometry. Bone injury comprised removal of the marrow followed by regeneration of the tissue via a phase of primary mineralization. A total number of 39,498 vesicles were traced on electron micrographs and sorted according to their diameters, distance from the calcified front and types. The different vesicular types were defined as follows: (a) vesicles with electron lucent contents, i.e. "empty", (b) vesicles with amorphous electron opaque contents, i.e. "amorphic", (c) vesicles containing crystalline depositions, i.e. "crystal", and (d) vesicles containing crystalline structures with ruptured membranes i.e. "rupture". The vesicles were studied on the days 3, 6, 14 and 21 after bone injury. Most of the vesicles were concentrated between diameters of 0.07 and 0.17 micron. Most of the vesicles were found in a distance less than 3 microns from the calcified front. The sequence of changes of distances from the calcified front and of the vesicular diameters were recorded as follows: "rupture", "crystal", "amorphic" and "empty", the "rupture" type being the closet to the front and of the largest diameter in each day. The results of the present study confirm the accepted hypothesis on calcification via extracellular matrix vesicles. It is thought that the cell secretes "empty" vesicles that accumulate Ca and Pi forming amorphous calcium phosphate that is then converted to hydroxyapatite. This is followed by rupture of the vesicular membrane.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Differences in cortical bone in overloaded and underloaded femurs from ovariectomized rats: comparison of bone morphometry with torsional testing.

Osteopenia and mechanical incompetence are the defining features of osteoporosis, yet the effects of changes in bone structure on mechanical properties are not completely understood. The primary objective of this study was to determine if in a rodent model, changes in cortical bone structure, as measured by static morphometry, would correlate with functional properties, as measured by torsional testing. For this, cortical bone structure and stiffness were determined in overloaded and underloaded limbs in rats rendered ovarian hormone-deficient by ovariectomy (OVX). Rats were OVX and six weeks later a hind limb was immobilized by casting for an additional six weeks. In all cases the femur from the underloaded, casted limb was compared with that from the contralateral, overloaded limb. The success of this experimental protocol was confirmed by differences in femoral cancellous bone volume by microradiography and single photon absorptiometry, with the overloaded limb having a greater bone volume and bone mineral density than the contralateral, immobilized controls. Morphometric differences in the femoral diaphyseal cortical bone included greater endocortical perimeter and endocortical osteoclast surface, less cortical area, less minimum cortical width, and less minimum cortical width at fracture planes when the bones were tested for stiffness in the underloaded, compared with the contralateral, overloaded limbs. Using a torsional test, the ultimate torque to failure and stiffness were less in the underloaded femurs compared with the contralateral, overloaded femurs. These results emphasize the importance of mechanical loading on bones from a gonad-deficient animal.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1993

Standardization of specimen preparation, staining, and sampling methods improves automated sperm-head morphometry analysis.

OBJECTIVES: To evaluate the accuracy and performance of the CellForm-Human automated sperm morphometry instrument (Motion Analysis Corp., Santa Rosa, CA) using different specimen preparation, staining, and analysis techniques. SETTING: Clinical and research andrology and in vitro fertilization laboratories. PATIENTS: Individuals who were undergoing semen evaluation and infertility work-up. RESULTS: The percentage of normal sperm detected by CellForm-Human was not different for washed specimens compared with nonwashed controls. Washing and resuspension to a standard concentration in medium significantly increased spermatozoan density and homogeneity on the slide. Comparison of digitization errors and morphometric measures of sperm stained by the Papanicolaou (PAP) method, the hematoxylin portion of the PAP method, and a new method developed by us, GZIN (pronounced Gee-ZIN), showed that GZIN produced larger measures for length, width, area, and perimeter, but not for width/length, and also produced less variability for most measures than PAP or hematoxylin. The number of digitization errors was significantly less for GZIN than for PAP. Visual inspection revealed that GZIN produced a more consistent stain over the entire sperm head than hematoxylin. The number of sperm analyzed affected the percentage of normal sperm detected. The % normal stabilized only after at least 200 sperm had been analyzed for each man. CONCLUSIONS: Technical variability arising from semen preparation and slide staining methods can be reduced when specimens are washed and resuspended to a standard concentration before smearing. At least 200 sperm should be analyzed to obtain a stable estimate of the percentage of normal sperm. More sperm should be analyzed if the % normal is < 50%. Morphometric measurements are more accurate and precise when sperm are stained with GZIN than when stained with PAP or hematoxylin.

Cytological Techniques↗

PubMed1991

Histology and morphometry of Strongylus vulgaris-mediated equine mesenteric arteritis.

Histological and morphometric evaluation of equine cranial mesenteric arteries was performed on 239 and 89 arteries, respectively. Histological examination revealed that thrombosis and the severity of inflammation varied on a seasonal basis and were directly associated with larval presence. Intimal and adventitial fibrosis were generally of greater severity than medial fibrosis. Fibrosis of the vasa vasorum was less frequent than fibrosis of the artery itself. Morphometry revealed a significant increase in intimal, adventitial and, to a lesser extent, medial area in affected as compared with normal arteries. This change was due to the accumulation of collagen and was considered to result in decreased arterial elasticity. The luminal area varied widely among affected arteries.

Animals↗