SEARCH · PubMed Health

Results for “computational morphology”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 631 records · Page 35Linked to original sources

PubMed1999

Cross-sectional morphology of the SK 82 and 97 proximal femora.

Computed tomography scans of the proximal femoral shaft of the South African "robust" australopithecine, A. robustus, reveal a total morphological pattern that is similar to the specimen attributed to A. boisei in East Africa but unlike that of Homo erectus or modern human femora. Like femora attributed to H. erectus, SK 82 and 97 have very thick cortices, although they do not have the extreme increase in mediolateral buttressing that is so characteristic of H. erectus. And unlike H. erectus or modern humans, their femoral heads are very small relative to shaft strength. These features are consistent with both increased overall mechanical loading of the postcranial skeleton and a possibly slightly altered pattern of bipedal gait relative to that of H. erectus and modern humans.

Anatomy, Cross-Sectional↗

PubMed2003

Analysis of eggplant ( Solanum melongena)-related germplasm: morphological and AFLP data contribute to phylogenetic interpretations and germplasm utilization.

A total of 94 Solanum accessions, including eggplants and related species, were morphologically characterized based on greenhouse observations, and molecularly analysed by the AFLP technique. Morphological parameters were helpful in assessing similarities or differences among accessions, and molecular data were used to support morphological conclusions. A dendrogram was computed based on the Dice genetic distances using the neighbour-joining method. The analysis was efficient in the assignment of a species name for eight out of nine accessions that were not previously classified, and revealed that 14 further accessions were misnamed in the collection originally received. The results indicate that the taxonomy of Solanum sections and subgenera including several species should be reconsidered. The AFLP technique was revealed as an efficient tool in determining genetic relationships among species. In general, morphological observations were consistent with molecular data, indicating that both approaches complemented to define the phylogenetic status of a large genus like Solanum. In terms of eggplant breeding, the molecular analysis of the Melongena complex, and of the other sections of the subgenus Leptostemonum, establishes useful germplasm relationships in the gene pool available for the genetic improvement of the cultivated species. The results we have provided highlight an urgent necessity to include molecular parameters in handling and characterizing the genebank-deposited germplasm related to cultivated crops.

Breeding↗

PubMed1985

Cellular migration and morphology in corneal endothelial wound repair.

After a mechanical denudation of rabbit corneal endothelial cells, the healing process was followed with wide-field specular microscopy. Individual cell migration and morphologic changes were analyzed by computer-assisted morphometry. The cells surrounding the wound migrated to cover the defect without producing intercellular gaps. The greatest cellular migration and morphologic alterations occurred close to the wound edge. As the cells migrated toward the wound, they elongated and increased their surface area in the direction of the migration. As the healing proceeded, the cells lost their original hexagonal pattern, which returned after coverage was complete. The wound was covered completely by large, irregularly shaped cells showing mitotic figures between 24 and 48 hr. During this period, cellular migration decreased and normal cellular morphology began to recover. When mitosis decreased, the normal cellular pattern rearranged towards a more hexagonal shape. During the healing process, the degree and direction of cellular migration varied from cell to cell. Additionally, changes in cell-to-cell contact (positional changes of neighboring cells) occurred in one-third of migrating cells. Such cellular migration can account for monolayered cells sliding without producing gaps between individual cells.

Animals↗

PubMed2026

Higher Rates of PASS and SCB After Arthroscopic Subspine Decompression Are Associated With a Positive Diagnostic AIIS Injection: A Propensity Score-Matched Cohort Study.

BACKGROUND: Hip arthroscopy effectively treats femoroacetabular impingement syndrome (FAIS), but persistent pain may be related to concomitant extra-articular pathology such as subspine impingement syndrome (SSI). Standard diagnosis of SSI often relies on 3-dimensional computed tomography (3D-CT) morphology (Hetsroni type II/III), although this morphology is common in individuals who are asymptomatic and correlates poorly with symptoms. PURPOSE: To compare minimum 2-year clinical outcomes after arthroscopic subspine decompression in patients with concurrent FAIS and type II/III anterior inferior iliac spine (AIIS) morphology, stratified by diagnostic method: 3D-CT morphology alone versus 3D-CT morphology plus a positive ultrasound-guided diagnostic injection. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: This study included patients aged 18 to 55 years with type II/III AIIS morphology who underwent primary hip arthroscopy for FAIS and SSI between January 2021 and November 2023 and had minimum 2-year follow-up. Patients diagnosed by CT morphology alone (CT classification group) were propensity score matched 1:1 to patients with a positive ultrasound-guided AIIS injection (injection group), with 57 patients per group. Matching variables were age, sex, body mass index, lateral center-edge angle, alpha angle, Tönnis grade, and Beighton score. All patients underwent arthroscopic subspine decompression. Patient-reported outcomes and rates of achieving the minimal clinically important difference, Patient Acceptable Symptom State (PASS), and substantial clinical benefit (SCB) were compared. RESULTS: Preoperative patient-reported outcome scores were similar between groups (all P > .05). At minimum 2-year follow-up, the injection group had significantly better scores on the modified Harris Hip Score (90.8 vs 84.2), Hip Outcome Score-Activities of Daily Living (88.4 vs 82.4), Hip Outcome Score-Sports Subscale (71.9 vs 64.1), 12-item International Hip Outcome Tool (83.9 vs 76.1), and visual analog scale for pain (1.2 vs 2.0) (all P < .001). Minimal clinically important difference rates were high in both groups, with higher rates in the injection group for modified Harris Hip Score (93% vs 77%; P = .033) and Hip Outcome Score-Activities of Daily Living (91% vs 75%; P = .042). PASS and SCB rates were significantly higher in the injection group across all patient-reported outcome measures (all P < .05). Revision and complication rates were low and did not differ significantly between groups. CONCLUSION: Both groups improved significantly after arthroscopic subspine decompression. However, patients with a positive ultrasound-guided diagnostic AIIS injection achieved higher PASS and SCB rates than those selected by CT morphology alone, suggesting that injection-confirmed SSI may improve patient selection for subspine decompression.

Humans↗

PubMed1989

Morphology of fibroblasts in collagen gels: a study using 400 keV electron microscopy and computer graphics.

We have used 400 kilovolt intermediate voltage electron microscopy (IVEM) to examine thick sections of fibroblasts cultured in collagen gels. In these 3D collagen lattices, the long, narrow pseudopodial extensions that extend out and make contact with the collagen matrix exhibit a complex topography not seen in the processes put out by cells moving on planar substrata. For this reason, sections 1 to 2 microns thick that enclose a whole cell process are more informative of the overall morphology of the interaction between cells and the collagen than are thin sections. To aid the discrimination of topography of cell processes in stereo views of micrographs, some cells were labeled with antibodies and protein A-colloidal gold conjugates. The gold particles provided clear 3D reference points for computer-aided reconstructions of membrane topography from tilt series of IVEM images. Our results confirm that cells that move through collagen lattices lack the well-spread morphology of their counterparts moving on glass. They are generally rather spindly with several long branching anterior pseudopodia. We found that the cell bodies and major pseudopodial processes were cylindrical, as one might expect of cells in a 3D environment, but at the leading edge of advancing pseudopodia there are small flat extensions similar to those seen in cells on glass. This similarity suggests that the lamellipodium is a basic type of protrusive structure used by fibroblasts during locomotion on all types of substratum. The flattened shape of lamellipodia may be part of the mechanism by which cells sense the orientation of fibrillar extracellular matrices during embryonic morphogenesis.

Animals↗

PubMed2002

Pulmonary iron overload in thalassemia major presenting as small airway disease.

Lung function abnormalities that are associated with thalassemia major are variable with etiology that is yet undetermined. Some studies have suggested that pulmonary iron deposition is a probable cause for these lung defects although there has been no antemortem histopathological and radiological evidence for this. We report a case of thalassemia major with biopsy-proven pulmonary iron overload, in which thoracic high-resolution computed tomography revealed a morphological-functional correlation consistent with small airway disease.

Adult↗

PubMed2005

Usefulness of helical computed tomography in diagnosing pulmonary vein stenosis in infants.

We investigated the usefulness of helical computed tomography(CT)in the morphological diagnosis of pulmonary vein stenosis, particularly that in infants and small children. In total, 20 helical CT examinations were performed in 10 post-operative cases of Total Anomalous Pulmonary Venous Drainage(TAPVD), 3 cases of single right ventricle, and 1 case of single left ventricle. In all cases, distinct morphological imaging was possible. Pulmonary vein stenosis could be categorized into three types: (1)stenosis from the anastomosis of the common pulmonary vein (CPV)-the left atrium (LA) to the peripheral pulmonary vein; (2) stenosis only at the anastomosis of CPV-LA; and (3) stenosis due to compression by nearby organs. Coronal views by multiplanar reconstruction (MPR) provided morphological information along the up-down direction of the body axis. Morphological diagnosis of pulmonary vein stenosis is important in deciding prognosis and therapeutic regimens, and helical CT was considered useful for such diagnosis in our 14 young patients.

Child, Preschool↗

PubMed2005

3D morphology of cell cultures: a quantitative approach using micrometer synchrotron light tomography.

Current issues in both tissue engineering and cell biology deal with cell behavior extensively in 3D. Here, we explore synchrotron radiation micro-computed tomography as a tool for morphological characterization of such 3D cellular constructs, providing micrometer resolution in soft and hard tissues. Novel image processing techniques allowed quantification of local and global cell distributions, cell density, adhesive cell culture surface, and scaffold geometry. For proof of concept, we applied this technique to characterize the morphology of two cell cultures of different phenotypes, namely human dermal fibroblasts and mouse calvarial osteoblast-like cells, both seeded on a polymer multifilament yarn. From 3D visualizations in these case studies, we saw that the fibroblasts spanned between the yarn filaments and in this way encapsulated the yarn, whereas the osteoblast-like cells lined the filament surfaces and did not span between them. Differences found in cell distribution as a function of distance to the median yarn axis and the closest filament surface, respectively, quantified these qualitative impressions gained from 3D visualizations. Moreover, the volume-normalized adhesive surface differed by one order of magnitude between the two phenotypes. Our approach allows quantitative correlation of local scaffold geometry and cell morphology. It can be used to investigate the influence of cell phenotype as well as various biochemical agents on tissue engineering constructs and the behavior of cells in culture.

Animals↗

PubMed1996

The relative effect of carotid plaque heterogeneity and echogenicity on ipsilateral cerebral infarction and symptoms of cerebrovascular disease.

OBJECTIVE: To determine the relative effect of carotid plaque heterogeneity and echogenicity as measured by computer on the incidence of ipsilateral cerebral infarction and symptoms of cerebrovascular disease. MATERIALS AND METHODS: 138 patients with 209 carotid plaques producing > 50% stenosis were studied. 110 plaques were from symptomatic sides. All patients had computer tomography (CT) brain scans. Images of the carotid plaques obtained by duplex scanner were transferred to a computer. Using an image analysis program plaque echogenicity, measured as the grey scale median (GSM) and heterogeneity, evaluated as the heterogeneity index (HI) was calculated. RESULTS: 42% of plaques were associated with cerebral infarction. Symptomatic plaques and those associated with cerebral infarction were more echolucent and less heterogeneous than asymptomatic plaques and those not associated with cerebral infarction. Plaques with GSMs below or equal to 32 were associated with a significantly higher incidence of cerebral infarction. Plaques with GSMs below or equal to 32 were associated with a significantly higher incidence of cerebral infarction and symptoms of cerebrovascular disease than those with GSMs above this level (p < 0.01). Plaques with HIs below or equal to 20 were associated with a significantly higher incidence of symptoms of cerebrovascular disease as compared to those with HIs above this level (p < 0.01). CONCLUSIONS: Computer analysis of carotid plaque morphology is an objective tool that can identify high risk plaques. The potential of such analysis in the identification of asymptomatic patients with advanced carotid stenosis at a high risk of stroke should be explored in a natural history study.

Arteriosclerosis↗

PubMed1996

Value of high-resolution computed tomography in routine evaluation of lung transplantation recipients during development of bronchiolitis obliterans syndrome.

BACKGROUND: Chronic rejection is a major long-term complication after lung transplantation. The purpose of our study was to evaluate the role of repeated high-resolution computed tomographic examinations in monitoring the development of bronchiolitis obliterans syndrome after lung transplantation. METHODS: A total of 126 high-resolution computed tomographic examination in 13 lung transplant recipients was analyzed. During a mean follow-up period of 23 months, bronchiolitis obliterans syndrome developed in eight of the patients. A scoring system from 0 to 10 based on the number of chronic changes on high-resolution computed tomography was developed, and the score of each patient was compared with decline in the forced expiratory volume in 1 second and maximal forced expiratory flow rate of 50% of the forced vital capacity. RESULTS: The score of chronic changes, measured at 1 year after transplantation, correlated inversely with the values of forced expiratory volume in 1 second and maximal forced expiratory flow rate at 50% of the forced vital capacity (p < 0.05). Stage I bronchiolitis obliterans syndrome was associated with scores of 4 to 6 (mean 5.0), stage 2 with scores of 6 to 9 (mean 7.0), and stage 3 with scores of 6 to 9 (mean 7.7). The sensitivity of high-resolution computed tomography was 93% and its specificity was 92% when five chronic changes were used as a cutoff level. CONCLUSIONS: The progress of chronic changes on high-resolution computed tomography occurs concurrently with the development of bronchiolitis obliterans syndrome. High-resolution computed tomography may provide additional morphologic information for noninvasive evaluation of chronic lung rejection.

Adult↗

PubMed2006

Cortical bone development under the growth plate is regulated by mechanical load transfer.

Longitudinal growth of long bones takes place at the growth plates. The growth plate produces new bone trabeculae, which are later resorbed or merged into the cortical shell. This process implies transition of trabecular metaphyseal sections into diaphyseal sections. We hypothesize that the development of cortical bone is governed by mechanical stimuli. We also hypothesize that trabecular and cortical bone share the same regulatory mechanisms for adaptation to mechanical loads. To test these hypotheses, we monitored the development of the tibial cortex in growing pigs, using micro-computer tomography and histology. We then tested the concept that regulatory mechanisms for trabecular bone adaptation can also explain cortical bone development using our mechanical stimulation theory, which could explain trabecular bone (re)modelling. The main results showed that, from the growth plate towards the diaphysis, the pores of the trabecular structure were gradually filled in with bone, which resulted in increased density and cortical bone. The computer model largely predicted this morphological development. We conclude that merging of metaphyseal trabeculae into cortex is likely to be governed by mechanical stimuli. Furthermore, cortex development of growing long bones can be explained as a form of trabecular bone adaptation, without the need for different regulatory mechanisms for cortical and trabecular bone.

Adaptation, Physiological↗

PubMed1991

Effect of geometrical irregularities on propagation delay in axonal trees.

Multiple successive geometrical inhomogeneities, such as extensive arborization and terminal varicosities, are usual characteristics of axons. Near such regions the velocity of the action potential (AP) changes. This study uses AXONTREE, a modeling tool developed in the companion paper for two purposes: (a) to gain insights into the consequence of these irregularities for the propagation delay along axons, and (b) to simulate the propagation of APs along a reconstructed axon from a cortical cell, taking into account information concerning the distribution of boutons (release sites) along such axons to estimate the distribution of arrival times of APs to the axons release sites. We used Hodgkin and Huxley (1952) like membrane properties at 20 degrees C. Focusing on the propagation delay which results from geometrical changes along the axon (and not from the actual diameters or length of the axon), the main results are: (a) the propagation delay at a region of a single geometrical change (a step change in axon diameter or a branch point) is in the order of a few tenths of a millisecond. This delay critically depends on the kinetics and the density of the excitable channels; (b) as a general rule, the lag imposed on the AP propagation at a region with a geometrical ratio GR greater than 1 is larger than the lead obtained at a region with a reciprocal of that GR value; (c) when the electronic distance between two successive geometrical changes (Xdis) is small, the delay is not the sum of the individual delays at each geometrical change, when isolated. When both geometrical changes are with GR greater than 1 or both with GR less than 1, this delay is supralinear (larger than the sum of individual delays). The two other combinations yield a sublinear delay; and (d) in a varicose axon, where the diameter changes frequently from thin to thick and back to thin, the propagation velocity may be slower than the velocity along a uniform axon with the thin diameter. Finally, we computed propagation delays along a morphologically characterized axon from layer V of the somatosensory cortex of the cat. This axon projects mainly to area 4 but also sends collaterals to areas 3b and 3a. The model predicts that, for this axon, areas 3a, 3b, and the proximal part of area 4 are activated approximately 2 ms before the activation of the distal part of area 4.

Action Potentials↗

PubMed1988

Growth factor- and phorbol ester-induced changes in cell morphology analyzed by digital image processing.

We have developed the computer-aided image processing analysis to visualize and quantitate the cell motility and morphological changes in living cultured cells. The effect of growth factors on cell motility and morphology has been analyzed by this method. Insulin, insulin-like growth factor-I (IGF-I), and epidermal growth factor (EGF) elicited membrane rufflings in rat embryo fibroblast 3Y1 cells as well as in human epidermoid carcinoma KB cells. Insulin and IGF-I also induced ruffling membranes in Balb/c-3T3 cells. The quantitative analysis by the programmed trace mode of the AVEC system has shown that the motion of the membrane rufflings was observed within 2 min, reached the maximum level within 4-8 min, and rapidly decreased within 10-15 min after the addition of these growth factors. The analysis also revealed the temperature- and growth factor concentration-dependent changes in the motion of membrane rufflings elicited by these growth factors. 12-O-Tetradecanoylphorbol-13-acetate, one of the well-known tumor promoters, rapidly induced cell rounding in Balb/c-3T3 cells. This change of cell morphology could be also quantified by the trace mode analysis. The fluorescent phalloidin staining experiment indicated that these growth factor- or phorbol ester-induced morphological changes were accompanied by the reorganization of filamentous actin. Furthermore, we were able to visualize actin stress fibers in living EBTr cells by enhancing the video image and to follow the reduction of stress fibers induced by cytochalasin B without any fixation or fluorescent probes.

Actins↗

PubMed1977

[Clinical and morphological correlational analysis of different forms of myocardial infarct].

On the basis of a mathematical analysis carried out by a "Minsk--220" computer, the correlation between the most essential morphological changes in the coronary arteries, the peculiarities of myocardial infarction, history and its clinical manifestations were studied in 320 myocardial infarction cases (148 males and 172 females over 50 years of age) with the distinction of 276 clinical and morphological signs. The numerical assessment of the conjugation indices of the morphological changes and the clinical-laboratory data permitted to evaluate the role of each of the examined factors in the genesis of primary and secondary myocardial infarctions, their spreading in the heart muscle, and their clinical manifestations. It has been demostrated that similar changes in the coronary arteries that create a background for a relative circulatory insufficiency are realized in different forms of myocardial infarction. Relative coronary insufficiency varies widely and becomes the leading cause of myocardial ischaemia. The effect of other factors is interpreted as modifying, and some of them--as triggering. The presented correlations analysis proves the rationale of assessing each case of myocardial infarction in terms of the probability theory of patho- and morphogenesis of ischaemic heart disease.

Aged↗

PubMed2001

Endocast of Sambungmacan 3 (Sm 3): a new Homo erectus from Indonesia.

A new fossil calvaria, Sambungmacan 3 (Sm 3), described in New Fossil Hominid Calvaria From Indonesia--Sambungmacan 3 by Márquez et al., this volume, yields one of the most advanced and complete endocasts yet recovered from Java. This communication provides a thorough interpretation of the external anatomical landmarks observable on Sm 3. Using computer tomography (CT) and traditional morphological measurements, our comparative paleoneurological analyses show that while Sm 3 has a mosaic of features that are similar to both Indonesian and Chinese H. erectus, it also possesses significant characters reminiscent of later hominins. These include a greater degree of asymmetry characterized by a possible left-occipital, right-frontal petalial pattern, left-right volumetric cerebral asymmetry, and marked asymmetry in Broca's cap. Moreover, the frontal lobe offers a more rounded, shortened appearance in contrast to the flat, elongated appearance of other Indonesian fossils (e.g., Sangiran 17). Another unique trait is exhibited in the transverse plane where the widest breadth of Sm 3 occurs more superiorly than in other Indonesian H. erectus. Thus, the endocast of Sm 3 presents a unique morphology not seen previously in the hominin fossil record. While the strong modern human characteristics in this endocast may not represent a particular ancestry, they do allow us to recognize a new dimension of the remarkable variation in Indonesian Homo erectus.

Animals↗

PubMed1980

Cranial computerized tomography in cerebral palsy. An attempt at anatomo-clinical and radiological correlations.

Eighty infants with cerebral palsy including monoplegia, diplegia, quadriplegia, hemiplegia, choreoathetosis, hypotonia with mental retardation and cerebellar ataxia, underwent Computed Cranial Tomography (CCT). Specific morphological anomalies such as ventricular dilatation with or without diverticulum, cortical atrophy, low density areas and calcifications, occur with varying frequency in each clinical groups. There exists a good correlation between the pathogenesis of the lesions, clinical data and CCT pictures.

Athetosis↗

PubMedDate not supplied

The morphology of residual acetabular deficiency in childhood hip dysplasia: three-dimensional computed tomographic analysis.

Seventy hips (in 48 patients) in children with residual dysplasia resulting from developmental dysplasia of the hip (DDH) were evaluated by using three-dimensional computed tomographic (3DCT) imaging to clarify the nature and degree of acetabular and femoral head deformity. We noted four types of dysplastic acetabulae: type I, subtle deficiency of the acetabulum with a mild break in Shenton's line (24%); type II, anterosuperior deficiency (29%); type III, midsuperior deficiency (38%); and type IV, global deficiency (9%). In untreated DDH with complete dislocation, the deficiency was predictably midsuperior (type III). Isolated posterosuperior deficiency, which is common in neuromuscular conditions, was not seen in these normal children with DDH. The 3DCT method used produced a topographic "contact map" that replicates the contact relation between the acetabulum and the femoral head. Analyzing the femoral head-acetabular contact relation and the type of acetabular deficiency allows the surgeon to plan better surgical correction of hip dysplasia in children.

Acetabulum↗

PubMed1993

Comparison of measured and computed epicardial potentials from a patient-specific inverse model.

This study reports the first direct comparison of measured and computed epicardial potentials in which the specific anatomy of a test subject has been used to calculate the inverse electrocardiographic model. It is now feasible to obtain low-noise body surface potential maps and to incorporate accurate anatomic data into inverse procedures for the purpose of computing epicardial potential distributions. The direct verification of computed human epicardial distributions remains an important goal. The experiment reported here obtained direct measurements from six transcutaneous pacing wires that were attached to points on the epicardial surface of the human heart in an intact subject. From the same subject, a magnetic resonance scan was used to produce a specific thoracic model consisting of 5-mm cubes. The forward model uses the finite difference method to compute a forward transfer matrix that relates each of 26 epicardial regions to body surface measurements. The inverse computation was performed by zero-order Tikhonov regularization. Body surface potentials were used in the inverse procedure to compute epicardial potentials, which were then compared with direct epicardial measurements. The computed epicardial potentials were compared to the measured ones by correlation, which gave an amplitude-independent measure of similarity. Amplitude differences and time delays in computed potentials were observed, but the morphologic trend was generally well recovered. The results obtained indicate the sensitivity of the inverse model to a number of factors. The robustness of computed epicardial distributions to errors in assumed lung conductivity is shown. Results from a nonpatient-specific, but realistic, torso model are presented.(ABSTRACT TRUNCATED AT 250 WORDS)

Cardiac Pacing, Artificial↗