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PubMed2004

A proteomic approach for the analysis of instantly released wound and immune proteins in Drosophila melanogaster hemolymph.

Insects respond to microbial infection by the rapid and transient expression of several genes encoding antibacterial peptides. In this paper we describe a powerful technique, two-dimensional difference gel electrophoresis, that, when combined with mass spectrometry, can be used to study the immune response of Drosophila melanogaster at the protein level. By comparatively analyzing the hemolymph proteome of 2,000 third-instar Drosophila larvae, we identified 10 differential proteins that appear in the fruit fly hemolymph very early after an immune-challenge with lipopolysaccharides. These proteins can be assigned to the immune response, because they are not induced after sterile injury. Reduction of integral variability or quantification problems related to conventional two-dimensional electrophoresis and improvement of image analysis were achieved by the use of two fluorescent dyes to label the two different protein samples. Some of the immune-induced proteins, such as thioester-containing protein 2, can be assigned to specific aspects of the immune response; others were already reported as being involved in stress response. An immune-induced protein (CG18594) is homologous to a mammalian serine protease inhibitor that mediates the mitogen-activated protein kinase and the NF-kappa B signaling pathways. In addition, a number of proteins that had not been associated with the immune response before were isolated and identified, and some of these were still present in the hemolymph 4 h after injury. Determining the function of all of these immune-induced proteins represents an exciting challenge for increasing our knowledge of insect immunity.

Animals↗
PubMed1997

Ex vivo regulation of adrenal cortical cell steroid and protein synthesis, in response to adrenocorticotropic hormone stimulation, by the Ginkgo biloba extract EGb 761 and isolated ginkgolide B.

We previously demonstrated that repeated treatment of rats with the standardized extract of Ginkgo biloba leaves, EGb 761, and its bioactive component ginkgolide B (GKB), specifically reduces the ligand binding, and protein and messenger RNA expression of the adrenal mitochondrial peripheral benzodiazepine receptor (PBR), a key element in the regulation of cholesterol transport, resulting in decreased circulating corticosterone levels. Adrenocortical cells were isolated from rats treated with EGb 761 or GKB and cultured for 2 and 12 days. The effect of ACTH on normal and metabolically labeled cells was examined. Corticosterone levels were measured by RIA, and protein synthesis was analyzed by two-dimensional gel electrophoresis. Ex vivo treatment with EGb 761 and GKB resulted, respectively, in 50% and 80% reductions of ACTH-stimulated corticosterone production by adrenocortical cells cultured for 2 days compared with that by cells isolated from saline-treated rats. Two-dimensional gel electrophoresis analysis revealed that in cells from both control and drug-treated animals, ACTH induced the synthesis, at the same level, of a 29-kDa and pI 6.4-6.7 protein identified as the adrenal steroidogenic acute regulatory protein (StAR). In addition, treatment with EGb 761 and GKB specifically altered the synthesis of seven proteins, including inhibition of synthesis of a 17-kDa, identified as PBR. After 12 days in culture, ACTH-stimulated adrenocortical cell steroid synthesis was maintained, and it was identical among the cells isolated from animals treated with GKB or saline. Under the same conditions, the expression of PBR was recovered, whereas no effect of ACTH on the 29-kDa and 6.4-6.7 pI protein (StAR) or other protein synthesis could be seen. A comparative analysis of the effects of GKB and EGb 761 on adrenocortical steroidogenesis and protein synthesis identified, in addition to the 17-kDa PBR, target proteins of 32 kDa (pI 6.7) and 40 kDa (pI 5.7-6.0) as potential mediators of the effect of EGb 761 and GKB on ACTH-stimulated glucocorticoid synthesis. In conclusion, these results 1) validate and extend our previous in vivo findings on the effect of EGb 761 and GKB on ACTH-stimulated adrenocortical steroidogenesis, 2) demonstrate the specificity and reversibility of EGb 761 and GKB treatment, 3) question the role of the 29-kDa, 6.4-6.7 pI protein (mature StAR) as the sole mediator of ACTH-stimulated steroid production, and 4) demonstrate the obligatory role of PBR in hormone-regulated steroidogenesis.

Adrenal Cortex↗
PubMed2002

Clinical applications of three-dimensional photography in breast surgery.

Three-dimensional imaging in breast surgery has several uses clinically. The most practical applications are for the evaluation of breast asymmetries, both congenital and acquired, and for the evaluation of factors affecting breast shape in augmentation mammaplasty. Other uses of three-dimensional imaging that we have found clinically helpful are for evaluation of patients desiring reduction mammaplasty and for evaluation of patients undergoing unilateral breast reconstruction to determine the expander and permanent implant size that gives the best symmetry with the contralateral breast. We present five cases in which we investigate the use of three-dimensional imaging clinically by using the images to determine quantitative information about the breast, such as volume or projection. Overall, three-dimensional imaging is very helpful in providing objective information about the breast for use in preoperative planning. In addition, by analyzing clinical cases, it can provide objective data about the breast and surgical mammaplasty (especially augmentation mammaplasty) that may help surgeons better understand those factors that contribute to breast shape and influence surgical outcomes. There are currently some limitations of this system, influenced by patients with significant ptosis or obesity, which may introduce errors into the three-dimensional data, making them unreliable. However, we believe three-dimensional imaging has great clinical potential in surgical mammaplasty.

Adolescent↗
PubMed2001

Computer-assisted fracture reduction: novel method for analysis of accuracy.

Anatomic reduction of displaced fractures is limited by the chosen surgical approach and intraoperative visualization. Preoperative Computed Tomography (CT) enhances the analysis of the fracture pattern and provides accurate spatial relationships. Computer Assisted Surgery (CAS) was introduced to increase the accuracy of specific surgical procedures. CAS systems can be used for implant placement or osteotomies in intact bone or reduced situations prior to obtaining the CT data, as differentiation into different datasets related to specific fragments is not yet possible. We present a model that allows "virtual" controlled reduction, providing computer assistance during the fracture reduction. Prior to clinical application, the accuracy of the process of virtual reduction must be proven in an experimental setting. An in vitro fracture model with two body fragments and a motion tracking system for three-dimensional (3D) control (accuracy 0.1 mm and 0.1 degrees ) was used. Two methods were employed: direct visualization and reduction by the examiner, and "virtual" reduction, performed solely with the use of a computer image, in which the examiner lacks any direct visualization of the fragments. The results of this very simplified "fracture" model indicate that the overall difference between direct and virtual controlled reduction was very small. A significant difference of 0.3 mm (0-1.8 mm) was seen for the residual displacement represented by the Euclidean distance (p < 0.01), whereas the difference in the residual angulation was not significant (p > 0.05). The methods tested revealed that virtual controlled reduction is nearly as accurate as direct visualization. Reduction control utilizing a motion tracker system reveals accurate 3D information in this simplified reduction setup, and is now used as a standard setup for analyzing realistic fracture models.

Fracture Fixation↗
PubMed2005

Three dimensional stress analysis of diabetic insole: a finite element approach.

Current research in foot biomechanics includes studies on prevention of recurrence of neuropathic foot ulcers. This paper attempts to prescribe accommodative insoles, which reduce plantar pressure levels particularly under the hallux. There is little quantitative information available regarding the effects of insole materials on reduction of plantar pressure. The insole models available in the literature are mostly two-dimensional (2-D). Hence, there is a need to develop a 3-D model with actual geometry which includes sufficient details. In this study a three-dimensional (3-D) model of the insole was constructed. A linear and non-linear static analysis using finite element method (FEM) was performed. Results were compared for different materials such as Silicon Gel, Plastozot, Polyfoam, and Ethinil Vinyl Acetate (EVA). Our 3-D finite element model was constructed using 16170 ten-node tetrahedral, mixed U-P (displacement-pressure), hyperelastic, solid elements. Four different hyperelastic and foam materials were used and compared and the loading condition was based on the mid-stance phase of the gait. This research has shown that most of these materials are very effective in terms of reduction of plantar stress concentrations. The technique used in this research provides a promising approach to understanding of behavior of insole materials and suggests a design guideline for therapeutic footwear and orthoses.

Biomechanical Phenomena↗
PubMed2001

Desmin integrates the three-dimensional mechanical properties of muscles.

Striated muscle is a linear motor whose properties have been defined in terms of uniaxial structures. The question addressed here is what contribution is made to the properties of this motor by extramyofilament cytoskeletal structures that are not aligned in parallel with the myofilaments. This question arose from observations that transverse loads increase muscle force production in diaphragm but not in the hindlimb muscle, thereby indicating the presence of structures that couple longitudinal and transverse properties of diaphragmatic muscle. Furthermore, we find that the diaphragms of null mutants for the cytoskeletal protein desmin show 1) significant reductions in coupling between the longitudinal and transverse properties, indicating for the first time a role for a specific protein in integrating the three-dimensional mechanical properties of muscle, 2) significant reductions in the stiffness and viscoelasticity of muscle, and 3) significant increases in tetanic force production. Thus desmin serves a complex mechanical function in diaphragm muscle by contributing both to passive stiffness and viscoelasticity and to modulation of active force production in a three-dimensional structural network. Our finding changes the paradigm of force transmission among cells by placing our understanding of the function of the cytoskeleton in the context of the structural and mechanical complexity of muscles.

Animals↗
PubMed1996

A Decomposition Principle for Complexity Reduction of Artificial Neural Networks.

A decomposition principle is developed for systematic determination of the dimensionality and the connections of Hopfield-type associative memory networks. Given a set of high dimensional prototype vectors of given memory objects, we develop decomposition algorithms to extract a set of lower dimensional key features of the pattern vectors. Every key feature can be used to build an associative memory with the lowest complexity, and more than one key feature can be simultaneously used to build networks with higher recognition accuracy. In the latter case, we further propose a "decomposed neural network" based on a new encoding scheme to reduce the network complexity. In contrast to the original Hopfield network, the decomposed networks not only increase the network's storage capacity, but also reduce the network's connection complexity from quadratic to linear growth with the network dimension. Both theoretical analysis and simulation results demonstrate that the proposed principle is powerful. Copyright 1996 Elsevier Science Ltd

Journal Article↗
PubMed1993

Improved in vitro angiogenesis model by collagen density reduction and the use of type III collagen.

Angiogenesis was examined by a three-dimensional model in vitro, using human umbilical vein endothelial cells (HUVECs) cultured in a collagen gel. An abundant capillary-like network with a lumen structure was identified histologically and shown to have formed at a collagen density of 0.05% or 0.10% instead of 0.15%, for either type I or type III collagen. At the same density, type III collagen induced a capillary-like network with HUVECs at an earlier stage of culture than type I collagen. In a two-dimensional culture, HUVECs were viable and proliferated to a great extent on the culture dish coated with collagen. This was particularly so in the case of type III collagen at lower density (5 ng/cm2). Type III collagen at a sufficiently low density is thus shown useful for studying angiogenesis in vitro. The capillary-like network that formed in the three-dimensional culture appeared somewhat labile, but became stable with the continuous addition of endothelial cell growth supplement and increase in the plating number of HUVECs.

Capillaries↗
PubMed2006

Inactivation of the group A Streptococcus regulator srv results in chromosome wide reduction of transcript levels, and changes in extracellular levels of Sic and SpeB.

Group A Streptococcus is characterized by the ability to cause a diverse number of human infections including pharyngitis, necrotizing fasciitis, toxic shock syndrome, and acute rheumatic fever, yet the regulation of streptococcal genes involved in disease processes and survival in the host is not completely understood. Genome scale analysis has revealed a complex regulatory network including 13 two-component regulatory systems and more than 100 additional putative regulators, the majority of which remain uncharacterized. Among these is the streptococcal regulator of virulence, Srv, the first Group A Streptococcus member of the Crp/Fnr family of transcriptional regulators. Previous work demonstrated that the loss of srv resulted in a significant decrease in Group A Streptococcus virulence. To begin to define the gene products influenced by Srv, we combined microarray and two-dimensional gel electrophoresis analysis. Loss of srv results in a chromosome wide reduction of gene transcription and changes in the production of the extracellular virulence factors Sic (streptococcal inhibitor of complement) and SpeB (cysteine proteinase). Sic levels are reduced in the srv mutant, whereas the extracellular concentration and activity of SpeB is increased. These data link Srv to the increasingly complex GAS regulatory network.

Antigens, Bacterial↗
PubMed1990

Clinical application of echocardiographic imaging to diagnosis of coronary artery disease.

Ergometer two-dimensional echocardiography was performed in 28 subjects complaining of chest pain but without myocardial infarction. Sequential ergometer loading was initiated at 50 or 75 watts, and increased in several stages. Apical four-chamber view two-dimensional echocardiograms were recorded onto video tape, and video images were converted into digital computer signals. After cine-loop display, computer image processing included noise reduction and edge enhancement, M-mode measurements were made at a designated level on the two-dimensional echo images. Wall motion was also analyzed directly from the two-dimensional echo images, using an auto-edge detection method. The derived data were compared with results from coronary angiograms. No echo abnormality was observed at rest, whereas during exercise wall motion was depressed at the diseased site of the angiogram; the amplitude of excursion and the changes in systolic and diastolic velocity were disturbed at the septum in LAD-involved patients, and in the posterolateral wall in both Cx and RCA patients. The imaging success rate using the computer-aided analysis was found to be 92.9%. Sensitivity for diagnosis of coronary artery disease was 82.1% and specificity 89.3%. Ergometer two-dimensional echocardiography with assisted computer image processing appears to be one of the most valuable tools for clinical real time evaluation of coronary artery disease.

Coronary Disease↗
PubMed2005

Noise suppression of point spread functions and its influence on deconvolution of three-dimensional fluorescence microscopy image sets.

The point spread function (PSF) is of central importance in the image restoration of three-dimensional image sets acquired by an epifluorescent microscope. Even though it is well known that an experimental PSF is typically more accurate than a theoretical one, the noise content of the experimental PSF is often an obstacle to its use in deconvolution algorithms. In this paper we apply a recently introduced noise suppression method to achieve an effective noise reduction in experimental PSFs. We show with both simulated and experimental three-dimensional image sets that a PSF that is smoothed with this method leads to a significant improvement in the performance of deconvolution algorithms, such as the regularized least-squares algorithm and the accelerated Richardson-Lucy algorithm.

Algorithms↗
PubMed1999

Kinematics of the chest cage and spine during breathing in healthy individuals and in patients with adolescent idiopathic scoliosis.

STUDY DESIGN: The lung function test by a Plethysmograph enabled calculations to be made of the total lung capacity and vital capacity. A Motion Analysis System (Elite, BTS Inc., Milano, Italy) was used to observe and record chest cage and spinal movements and as to correlate lung function with the chest cage and spine kinematics. OBJECTIVES: To determine the three-dimensional kinematics and the shape and size changes of the chest cage and thoracic spine motion during deep breathing in healthy and scoliotic individuals. SUMMARY OF BACKGROUND DATA: Lateral flexion plus rotation of the involved vertebrae around a vertical axis causing a decrease in lung function is the main disfigurement of scoliosis. Reports show that even after spinal fusion, reduced vital capacity associated with an increased residual volume are detected. Factors such as angle of scoliosis, length of the spinal column involved, and duration of the deformity influence pulmonary function but do not significantly affect its reduction. Mechanical inefficiency during breathing has not been studied. METHODS: Three-dimensional kinematics of the chest cage and spine during breathing were studied in 41 scoliotic patients and in 20 healthy individuals. Three-dimensional chest cage motions relative to the spine and thoracic spine motions relative to T12 were calculated. To examine stiffness of the spine, lateral bending angles were calculated. The lung function test, which including spirometry and lung subdivision, also was performed for the scoliotic patients. RESULTS: Significant differences (P < 0.05) were found in the movements of the upper level of the chest cage in anteroposterior and vertical directions, ranging from 16.7 to 28.6 mm in healthy individuals and from 12.1 to 24.2 mm in scoliotic patients. The thoracic spine displayed two-dimensional movements posteriorly and vertically during breathing, whereas less movement was seen in scoliotic patients. In addition, overall the scoliotic spine showed signs of stiffness in lateral bending. CONCLUSIONS: The range of movement of the chest cage and spine is more limited in the scoliotic cases. This overall stiffness of the chest cage and the spine may contribute to the mechanical inefficiency and impairment of pulmonary function found in scoliotic patients.

Adolescent↗
PubMed2000

Patient positioning in prostate radiotherapy: is prone better than supine?

PURPOSE: To assess potential dose reductions to the rectum and to the bladder with three-dimensional conformal radiotherapy (3D-CRT) to the prostate in the prone as compared with the supine position; and to retrospectively evaluate treatment position reproducibility without immobilization devices. METHODS AND MATERIALS: Eighteen patients with localized prostate cancer underwent pelvic CT scans and 3D treatment planning in prone and supine positions. Dose-volume histograms (DVHs) were constructed for the clinical target volume, the rectum and the bladder for every patient in both treatment positions. "Comparative DVHs" (cDVHs) were defined for the rectum and for the bladder: cDVH was obtained by subtracting the organ volume receiving a given dose increment in the prone position from the corresponding value in the supine position. These values were then integrated over the entire dose range. The prescribed dose to the planning target volume (PTV) was 74 Gy using a 6-field technique. To evaluate reproducibility, portal films were subsequently reviewed in 12 patients treated prone and 10 contemporary patients treated supine (controls). No immobilization devices were used. Deviations in the anterio-posterior (X) and cranio-caudal (Y) axes were measured. Mean treatment position variation, total setup variation, systematic setup variation, and random setup variation were obtained. RESULTS: Prone position was associated with a higher dose to the rectum or to the bladder in 6 (33%) and 7 (39%) patients, respectively. A simultaneously higher dose to rectum and bladder was noted in 2 (11%) patients in prone and in 7 (39%) patients in supine. Rectal and bladder volumes were frequently larger in prone than in supine: mean prone/supine volume ratios were 1.21 (SD, 0.68) and 1.03 (SD, 1.32), respectively. In these cases cDVH analysis more often favored the prone position. Mean treatment position variation and total setup variation were similar for both prone and supine plans. A higher systematic setup variation was observed in prone positioning: 2.7 mm vs. 1.9 mm (X axis) and 4.1 mm vs. 2.2 mm (Y axis). The random variation was similar for both prone and supine: 4. 0 mm vs. 3.6 mm (X axis) and 3.7 mm vs. 3.6 mm (Y axis). CONCLUSIONS: Prone position 3D-CRT is frequently, but not always, associated with an apparent dose reduction to the rectum and/or to the bladder for prostate cancer patients. As suggested by the increased mean prone/supine rectal volume ratio, the advantage of prone positioning for the rectum may be artifactual, at least partly reflecting a position-dependent rectal air volume, which may significantly vary from treatment to treatment. In the absence of immobilization devices, daily setup reproducibility appears less accurate for the prone position, primarily due to systematic setup variations.

Aged↗
PubMed1997

Fast three dimensional sodium imaging.

An efficient scheme for fast three dimensional acquisition of sodium MR images is described. This scheme relies on the use of three dimensional k-space trajectories with constant sample density to achieve significant (60-70%) reductions in total data acquisition time over conventional projection imaging schemes. The performance of this data acquisition scheme is demonstrated with acquisition of sodium data sets on phantoms and normal human volunteers at 1.5 and 3.0 Tesla. The experimental results demonstrate that high quality three dimensional sodium images (0.2 cc voxel size, 10:1 signal-to-noise ratio) can be acquired at clinical field strengths (1.5 Tesla) in under 10 min.

Computer Simulation↗
PubMed2004

[Hystero-salpingo-contrast-sonography with 3-d-ultrasound -- a pilot study].

UNLABELLED: Hystero-salpingo-contrast sonography (HyCoSy) is a sensitive method of assessing tubal patency but cannot completely substitute diagnostic laparoscopy with blue dye and hysteroscopy. Three-dimensional sonography has new imaging facilities which could lead to a reduction of invasive diagnostic procedures. AIM: The aim of this pilot study was to analyse the feasibility of HyCoSy by 3D- and 3D-Doppler-sonography. METHODS: In a prospective setting conventional (2D) HyCoSy was performed in 21 patients with an ultrasound device designed for 3D-ultrasound. After the completion of the 2D procedure, 3D-ultrasound was carried out. In five patients an additional 3D-Doppler-HyCoSy was performed. The generated 3D-volumina were then examined. Laparoscopy with blue dye was performed immediately after the ultrasound examination. RESULTS: A total of 42 Fallopian tubes was assessed. On 2D-ultrasound, visibility of the tubes was excellent in 28 and limited in seven tubes. Of the seven tubes not visible on 2D-ultrasound, four were not patent on laparoscopy. On 3D-ultrasound, visibility of the tubes was excellent in 15 and limited in twelve tubes. 15 tubes were not visible on 3D-ultrasound. 3D-Doppler-HyCoSy revealed excellent assessment in eight of ten tubes, even in one of those with limited visibility on 2D- and 3D-HyCoSy. In 19 patients the assessment of the uterine cavity was excellent by 2D- and 3D-HyCoSy, whereas it was limited in two patients. CONCLUSION: It is possible to visualise the full length of the tubes in a very detailed way from the uterine cavity to the fimbrial end in some patients, but the diagnostic power of HyCoSy is not improved by adding 3D-imaging. The accuracy of 3D-ultrasound seemed to be improved by 3D-Doppler-ultrasound.

Fallopian Tubes↗
PubMed1997

Diagnosis of congenital malformations using two-dimensional and three-dimensional ultrasonography.

Three-dimensional ultrasonography is a promising new method for the prenatal diagnosis of fetal malformations, which offers several potential advantages, including the reduction of scanning time and the ability to store images that can be reviewed and reconstructed at a later date. Three-dimensional ultrasonography, however, has many of the same limitations as the conventional two-dimensional version.

Anthropometry↗
PubMed2004

Speckle reduction in optical coherence tomography images by use of a spatially adaptive wavelet filter.

A spatially adaptive two-dimensional wavelet filter is used to reduce speckle noise in time-domain and Fourier-domain optical coherence tomography (OCT) images. Edges can be separated from discontinuities that are due to noise, and noise power can be attenuated in the wavelet domain without significantly compromising image sharpness. A single parameter controls the degree of noise reduction. When this filter is applied to ophthalmic OCT images, signal-to-noise ratio improvements of >7 dB are attained, with a sharpness reduction of <3%.

Algorithms↗
PubMed2006

Intensity-modulated radiotherapy improves lymph node coverage and dose to critical structures compared with three-dimensional conformal radiation therapy in clinically localized prostate cancer.

PURPOSE: The aim of this study was to quantify gains in lymph node coverage and critical structure dose reduction for whole-pelvis (WP) and extended-field (EF) radiotherapy in prostate cancer using intensity-modulated radiotherapy (IMRT) compared with three-dimensional conformal radiotherapy (3DCRT) for the first treatment phase of 45 Gy in the concurrent treatment of lymph nodes and prostate. METHODS AND MATERIALS: From January to August 2005, 35 patients with localized prostate cancer were treated with pelvic IMRT; 7 had nodes defined up to L5-S1 (Group 1), and 28 had nodes defined above L5-S1 (Group 2). Each patient had 2 plans retrospectively generated: 1 WP 3DCRT plan using bony landmarks, and 1 EF 3DCRT plan to cover the vascular defined volumes. Dose-volume histograms for the lymph nodes, rectum, bladder, small bowel, and penile bulb were compared by group. RESULTS: For Group 1, WP 3DCRT missed 25% of pelvic nodes with the prescribed dose 45 Gy and missed 18% with the 95% prescribed dose 42.75 Gy, whereas WP IMRT achieved V(45 Gy) = 98% and V(42.75 Gy) = 100%. Compared with WP 3DCRT, IMRT reduced bladder V(45 Gy) by 78%, rectum V(45 Gy) by 48%, and small bowel V(45 Gy) by 232 cm3. EF 3DCRT achieved 95% coverage of nodes for all patients at high cost to critical structures. For Group 2, IMRT decreased bladder V(45 Gy) by 90%, rectum V(45 Gy) by 54% and small bowel V(45 Gy) by 455 cm3 compared with EF 3DCRT. CONCLUSION: In this study WP 3DCRT missed a significant percentage of pelvic nodes. Although EF 3DCRT achieved 95% pelvic nodal coverage, it increased critical structure doses. IMRT improved pelvic nodal coverage while decreasing dose to bladder, rectum, small bowel, and penile bulb. For patients with extended node involvement, IMRT especially decreases small bowel dose.

Aged↗