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At least 613 records · Page 34Linked to original sources
PubMed1992

Lens regeneration in juvenile and adult rabbits measured by image analysis.

Secondary cataract growth commonly occurs after extracapsular cataract extraction. The proliferation of this regrowth occurs at rates related to many factors. In this study, the authors analyzed the amount of lens regeneration after endocapsular lens extraction that leaves the anterior and posterior capsules relatively intact. The analysis was performed in New Zealand albino rabbits with the aid of image analysis measurements in young and adult animals. The effect of low vacuum suction of the anterior capsule on the growth was determined. Lens regeneration was used as a measure of the growth potential of the leftover epithelial cells in the capsule bag. The results showed that lens regeneration was significantly faster in younger rabbits. However, low vacuum suction had no effect on the growth rate. Potential therapeutic agents for preventing secondary cataracts may be better analyzed with image analysis processing of lens regeneration, a precise and rapid measurement technique.

Aging↗
PubMed2001

Improved diagnostic yield of endoscopic biliary brush cytology by digital image analysis.

OBJECTIVE: To evaluate the accuracy of digital image analysis (DIA) for distinguishing between benign and malignant strictures of the biliary tract. PATIENTS AND METHODS: Our pathology databank was used to identify all biliary brush cytology specimens obtained during endoscopic retrograde cholangiopancreatography between June 1997 and June 1999. Corresponding medical records were reviewed to determine whether patients had benign or malignant strictures. Strictures were further classified into benign strictures with negative routine cytology, malignant strictures with negative routine cytology, and malignant strictures with positive routine cytology. Papanicolaou-stained smears of available brush cytology specimens were destained and then restained with Feulgen dye. Nuclear images were quantified for DNA content without knowledge of stricture type. DNA histograms were generated and ploidy results compared with the class of stricture. RESULTS: We analyzed 27 specimens from 69 confirmed benign or malignant strictures. Assuming that the presence of any aneuploid cells indicated malignancy, the sensitivity of DIA was 85%. Furthermore, aneuploid cells were detected by DIA in 13 of 16 specimens in which routine cytology was unrevealing. CONCLUSION: Ploidy assessment by DIA has potential to enhance the sensitivity of diagnosing malignant strictures compared with routine cytology alone.

Adult↗
PubMed1996

DNA measurement in pituitary adenomas assessed on imprints by image analysis.

OBJECTIVE: To determine the DNA content and S-phase fraction (SPF) of pituitary adenomas by image analysis and to correlate them with clinical and morphologic parameters. STUDY DESIGN: The study group consisted of 26 prospectively collected cases of operated pituitary adenomas (3 microadenomas and 23 macroadenomas). The tumors were classified by histology, immunocytochemistry and electron microscopy. DNA measurement was performed on imprints from fresh pituitary tissue. Samples of nontumorous adenohypophysial parenchyma served as normal controls. RESULTS: Overall, 31% of adenomas, all but one functioning one, were aneuploid. The remaining nonfunctioning aneuploid tumor was a null cell adenoma with glycoprotein differentiation. All aneuploid tumors were macroadenomas, mostly at advanced stages, III and IV. Dural invasion, although frequent in macroadenomas (78%), was not correlated with DNA ploidy and SPF. An increased number of hyperpentaploid aneuploid cells was noted primarily in aneuploid tumors. The mean SPF was < 2.50%, with a statistically significant difference between aneuploid and diploid adenomas (3.60% vs. 1.70%). CONCLUSION: The results suggest that quantitative assessment of DNA content may provide important information, particularly in functioning adenomas. In addition, fresh tissue imprints represent excellent material for optimum cytometric measurements by image analysis systems, even for microadenomas.

Adenoma↗
PubMed1996

Immunohistochemical localization and quantitative analysis of cellular glutathione peroxidase in foetal and neonatal rat tissues: fluorescence microscopy image analysis.

To quantitate the developmental changes in selenium-dependent cellular glutathione peroxidase during the perinatal period, tissue sections from foetal (day 12 to day 22) and neonatal (day 6) rats were stained immunohistochemically using specific polyclonal antiserum. The intensity of the staining was quantified by fluorescence microscopy image analysis. There was a general trend of enriched glutathione peroxidase in the epithelial linings and metabolically active sites. Significant fluorescence was detected in cardiomyocytes, hepatocytes, renal tubular epithelium, bronchiolar epithelium and intestinal epithelium at day 15. The intensity increased in a stepwise manner thereafter. The overall increase in the intensity of staining in the heart, liver, kidneys, lungs and intestine was 1.5-, 2.3-, 1.6-, 1.7- and 3.0-fold, respectively. The phase of most rapid increase occurred during the foetal period in the liver, intestine and heart. In the kidneys and lungs, glutathione peroxidase increased significantly during foetal life, and to a similar extent postnatally. These results suggest that the intracellular H2O2-scavenging system develops during the foetal period as an essential mechanism for living under atmospheric oxygen conditions. The late development observed in the kidneys and lungs is consistent with the relative biological immaturity of these organs in full-term neonates.

Animals↗
PubMed1998

Rapid determination of bacterial abundance, biovolume, morphology, and growth by neural network-based image analysis

Annual bacterial plankton dynamics at several depths and locations in the Baltic Sea were studied by image analysis. Individual bacteria were classified by using an artificial neural network which also effectively identified nonbacterial objects. Cell counts and frequencies of dividing cells were determined, and the data obtained agreed well with visual observations and previously published values. Cell volumes were measured accurately by comparison with bead standards. The survey included 690 images from a total of 138 samples. Each image contained approximately 200 bacteria. The images were analyzed automatically at a rate of 100 images per h. Bacterial abundance exhibited coherent patterns with time and depth, and there were distinct subsurface peaks in the summer months. Four distinct morphological classes were resolved by the image analyzer, and the dynamics of each could be visualized. The bacterial growth rates estimated from frequencies of dividing cells were different from the bacterial growth rates estimated by the thymidine incorporation method. With minor modifications, the image analysis technique described here can be used to analyze other planktonic classes.

Journal Article↗
PubMed2001

Evaluation of diagnostic efficiency of computerized image analysis based quantitative nuclear parameters in papillary and follicular thyroid tumors using paraffin-embedded tissue sections.

Computerized image analysis (IA) system has emerged in recent years as a very powerful tool for objective and reproducible quantification of histological features. It has shown considerable potential for diagnostic application in diverse histological situations. The objectives of the present study were to evaluate the discriminatory diagnostic efficiency of computerized image analysis based quantitative subvisual nuclear parameters in papillary and follicular neoplasms of thyroid. A total of 60 cases were studied. Forty-four cases belonged to training set and 16 cases belonged to a test set. A minimum of 100 nuclei was analyzed in each case using uniform 5 m mm thick hematoxylin stained sections. The IA workstation comprised of an Olympus microscope, a 10 bit digital video camera, an image grabber card and a pentium 120 MHz computer. Optimas 5.2 software was utilized for data collection on 8 morphometric and 8 densitometric parameters. Multivariate stepwise discriminant statistical analysis of data was done with the help of BMDP statistical software release 7.0. Results from a training set revealed correct classification rates of 98.0%, 84.5% and 61.2% for the histological groups of hyperplastic papillae versus papillae of papillary carcinoma (group I), follicular variant of papillary carcinoma versus the broad category of follicular neoplasms consisting of both follicular adenoma and follicular carcinoma (group II) and follicular adenoma versus follicular carcinoma (group III), respectively. Results of test set revealed correct classification rates of 100%, 80% and 50% for groups I, II and III respectively. It was concluded that computerized nuclear IA parameters have potential usefulness for discriminating benign versus malignant papillary lesions of thyroid, follicular variant of papillary carcinoma versus follicular adenoma and/or follicular carcinoma but are of no value in discriminating between follicular adenoma and follicular carcinoma.

Adenocarcinoma, Follicular↗
PubMed2002

From pixels to picograms: a beginners' guide to genome quantification by Feulgen image analysis densitometry.

The study of genome size variation is important from a number of practical and theoretical perspectives. For example, the long-standing "C-value enigma" relating to the more than 200,000-fold range in eukaryotic genome sizes is best studied from a broad comparative standpoint. Genome size data are also required in detailed analyses of genome structure and evolution. The choice of future genome sequencing projects will be dependent on knowledge regarding the sizes of genomes to be sequenced, and so on. To date, genome size data have been acquired primarily by Feulgen microdensitometry or flow cytometry. Each has several advantages but also important limitations. In this review, we provide a practical guide to the new technique of Feulgen image analysis densitometry. The review is designed for those interested in genome size measurements but not extensively experienced in histochemistry, densitometry, or microscopy. Therefore, relevant historical and technical background information is included. For easy reference, we provide recipes for required reagents, guidelines for cell staining, and a checklist of steps for successful image analysis. We hope that the accuracy, rapidity, and cost-effectiveness of Feulgen image analysis demonstrated here will stimulate further surveys of genome sizes in a variety of taxa.

Animals↗
PubMed1995

Quantitative image analysis of cell proliferation after balloon catheter injury in the rabbit carotid artery.

OBJECTIVE: To perform color image analysis to assess the course of morphometric and proliferative changes in the intima and media of rabbit carotid arteries following balloon injury. STUDY DESIGN: Proliferating smooth muscle cells were labeled with proliferating cell nuclear antigen and vizualized by immunohistochemical staining of histologic sections. Morphometry was performed on histologic cross-sections of injured arteries stained with hematoxylin. RESULTS: The development of intimal hyperplasia following an acute mechanical injury was detectable early on and was accompanied by a burst of cell proliferation. Medial cell proliferation peaked on day 3 after balloon injury, and the maximum of intimal cell proliferation was noted on day 7. CONCLUSION: The color image analysis method described here could be a useful tool in evaluating drugs for their ability to prevent restenosis.

Animals↗
PubMed1997

Automated image analysis DNA cytometry to predict the pathological stage in clinical stage I nonseminomatous testicular germ cell tumors.

OBJECTIVE: Automated image analysis DNA cytometry was used to predict the pathological stage in clinical stage I nonseminomatous testicular germ cell tumor patients. METHODS: Orchiectomy specimens of 74 patients (41 pathological stage I, 33 pathological stage II) were analyzed by modular image analysis computer, and several mathematical indices from the DNA histogram were calculated. RESULTS: The 5c-exceeding rate (rate of hyperpentaploid nuclei) was found to be significantly higher in patients with pathological stage II disease as compared with patients without metastases (p = 0.0174). Tumor tissue from lymph node metastases showed even higher amounts of hyperpentaploid nuclei (p < 0.0005). In this study, all patients with a 5c-exceeding rate above 3.1% had metastatic disease. CONCLUSIONS: Single-cell cytophotometry was able to show significant differences in 5c-exceeding rates between patients with and without tumor metastases. Because of high standard deviations, however, it was not possible to use this parameter for correct staging in all patients.

Analysis of Variance↗
PubMed1993

Image analysis DNA cytometry of bladder cancer.

In a retrospective analysis, the DNA histograms of 65 paraffin-embedded bladder carcinomas from radical cystectomy specimens (stage pT1-pT4a, pN0, pN1, pN2) were analyzed using an automated image analysis system (Leytas 2). Automated image analysis was able to characterize invasive bladder carcinoma as being either diploid, polyploid, or aneuploid. Within the group of aneuploid tumors, the DNA content of the stem-cell line allowed further subtyping of the tumors; hypotriploid, hypertriploid, hypertetraploid, and even hyperpentaploid tumors could be distinguished. Comparing different sites of identical tumors, the DNA histogram was found to be a stable and reproducible tumor characteristic. The various tumor types differed significantly in prognosis. This technique can also be applied to smears of urine sediment or transurethrally resected tumor chips. In the case of superficial tumors, DNA cytometry defines those tumors which are potentially invasive, requiring careful follow-up and/or early aggressive treatment.

DNA, Neoplasm↗
PubMed2004

Relationship between computed tomographic image analysis and histomorphometry for microarchitectural characterization of human calcaneus.

The present study aimed to characterize the relationships between several variables reflecting bone microarchitecture assessed by both computed tomographic (CT) image analysis and histomorphometry (conventional CT system) at the calcaneus. A total of 24 cadaveric specimens were studied. The mean age at death was 78 +/- 10 years (range, 53-93 years). A total of 15 sagittal sections (1 mm in width and spaced 2 mm apart) were selected for CT analysis; 6 undecalcified sections (7 microm) were analyzed for histomorphometry. The histomorphometric analysis was performed on a Leica Quantimet Q570 image analyzer. Features measured by both methods were: bone volume/tissue volume (BV/TV), trabecular thickness (Tb.Th), trabecular separation (Tb.Sp), trabecular number (Tb.N), interconnectivity index (ICI), number of nodes (N Nd), number of terminus (N Tm), node-to-node strut count (NNS), node-to-terminus strut count (NTS), terminus-to-terminus strut count (TTS), marrow space star volume (SV), Euler number (EN), and fractal dimension (FD). The coefficient of correlations' values (simple linear regression) between histomorphometry and CT image analysis varied according to the parameters selected. R values were high for BV/TV, Tb.N, and Tb.Sp (range, 0.69-0.90; P < 0.01). R values were less significant for some variables also obtained from the binary image: SV (0.5, P < 0.05) and EN (0.43, P < 0.05). Finally R values were also significant for (two) variables obtained from skeletonized images, i.e., N Nd (0.4, P < 0.05) and N Tm (0.61, P < 0.01). Other correlations were not statistically significant. Moreover, for some variables the relationships between the two methods (CT analysis and histomorphometry) seemed best-described by using nonlinear models. For example, a logarithmic model was more appropriate for SV (r = 0.71, P < 0.01), N Nd (r = 0.52, P < 0.01). Finally the relationship between apparent (App) N Tm and N Tm was most satisfying when using an exponential model (r = 0.64, P < 0.01). In conclusion, trabecular bone structure measures determined on CT images show highly significant correlations with those determined using histomorphometry. The level of correlation varies according to the type of method used for characterizing bone structure, however, and the strongest correlations were found for the most basic features (Parfitt's parameters). Finally, for some variables, nonlinear models seem more appropriate.

Absorptiometry, Photon↗
PubMed2004

Noninvasive monitoring of hemoglobin. The effects of WBC counts on measurement.

The efficacy of a noninvasive hemoglobin monitoring device (Astrin, Sysmex, Kobe, Japan) was evaluated for healthy volunteers and for patients with hematologic disorders. At the same time, the effects of WBC counts on noninvasive monitoring were studied by clinical evaluation and in ex vivo experiments. The hemoglobin levels determined by the device (Ast-Hb) and a conventional analyzer (T-Hb) were compared. The coefficient of correlation between findings with the Ast-Hb and the T-Hb for healthy volunteers was r = 0.626, whereas that for patients with hematologic disorders was r = 0.762. A comparison of the ratios of measurement errors in hemoglobin levels by Ast-Hb and T-Hb indicated that the number of WBCs had no effect on hemoglobin monitoring. Moreover, ex vivo studies using isolated WBCs and an optical model that imitates blood vessels and tissue in human fingers confirmed these results. Therefore, this new hemoglobin monitoring device can be expected to be useful for continuous hemoglobin monitoring.

Female↗
PubMed1991

Hepatic uptake of fluorescein, investigated by video fluorescence microscopy and digital image analysis.

We evaluated fluorescence microscopy combined with digitized image analysis for the investigation of fluorescein transport in the intact rat liver. The images of the surface of isolated rat livers which were perfused directly under a microscope were projected onto a silicone-intensified target camera, stored on a video tape and analyzed with a microcomputer equipped with an image digitizer. It was shown that, after correction of the day-to-day variability of the optical and electronical system, the increase in fluorescence intensity of the liver surface following fluorescein infusion depended linearly on the fluorescein concentration in the perfusion medium up to 1 mM. Since, under the conditions used, biliary secretion and metabolic influences were found to be insignificant the uptake mechanism is probably predominantly simple diffusion.

Animals↗
PubMed2005

Quantitative atomic force microscopy image analysis of unusual filaments formed by the Acanthamoeba castellanii myosin II rod domain.

We describe a quantitative analysis of Acanthamoeba castellanii myosin II rod domain images collected from atomic force microscope experiments. These images reveal that the rod domain forms a novel filament structure, most likely requiring unusual head-to-tail interactions. Similar filaments are seen also in negatively stained electron microscopy images. Truncated myosins from Acanthamoeba and other model organisms have been visualized before, revealing laterally associated bipolar minifilaments. In contrast, the filament structures that we observe are dominated by axial rather than lateral polymerization. The unusually small features in this structure (1-5 nm) required the development of quantitative and statistical techniques for filament image analysis. These techniques enhance the extraction of features that hitherto have been difficult to ascertain from more qualitative imaging approaches. The heights of the filaments are observed to have a bimodal distribution consistent with the diameters of a single rod domain and a pair of close-packed rod domains. Further quantitative analysis indicates that in-plane association is limited to at most a pair of rod domains. Taken together, this implies that the filaments contain no more than four rod domains laterally associated with one another, somewhat less than that seen in bipolar minifilaments. Analysis of images of the filaments decorated with an anti-FLAG antibody reveals head-to-tail association with mean distances between the antibodies of 75 +/- 15 nm. We consider a set of molecular models to help interpret possible structures of the filaments.

Acanthamoeba castellanii↗
PubMed2006

Image analysis as an adjunct to sodium rhodizonate test in the evaluation of gunshot residues: an experimental study.

It is important to investigate the clothing, as well as the body, to determine the range of fire of entry wounds in firearm injuries. Clothing can affect the amount of gunshot residues (GSR) reaching the body and their distribution. The amount and distribution of the GSR also vary according to the distance between the firearm and the target. Sodium rhodizonate test provides valuable data when clothing is available for examination. In the absence of clothing, light microscopic examinations may add additional information regarding the range of fire. In this study, a sodium rhodizonate test was done on 80 garment samples containing the bullet entrance. The 80 calfskin samples were processed histologically and were stained using Alizarin Red S. These were also evaluated with computer-assisted image analysis. Gross residues were seen on military camouflage clothing in samples from < or = 45-cm group. White flannel undershirts under the military camouflage contained rhodizonate-positive particles only around the contact wounds. With image analysis, however, the residues could be detected also in the skin samples of the 2.5-cm- and 5-cm-range groups. We suggest that the image analysis can be combined with other techniques and it can provide valuable data in the determination of entry wounds and also in the estimation of firing distance.

Clothing↗
PubMed1995

Image analysis in comparative genomic hybridization.

Comparative genomic hybridization (CGH) is a new technique by which genomic imbalances can be detected by combining in situ suppression hybridization of whole genomic DNA and image analysis. We have developed software for rapid, quantitative CGH image analysis by a modification and extension of the standard software used for routine karyotyping of G-banded metaphase spreads in the Magiscan chromosome analysis system. The DAPI-counterstained metaphase spread is karyotyped interactively. Corrections for image shifts between the DAPI, FITC, and TRITC images are done manually by moving the three images relative to each other. The fluorescence background is subtracted. A mean filter is applied to smooth the FITC and TRITC images before the fluorescence ratio between the individual FITC- and TRITC-stained chromosomes is computed pixel by pixel inside the area of the chromosomes determined by the DAPI boundaries. Fluorescence intensity ratio profiles are generated, and peaks and valleys indicating possible gains and losses of test DNA are marked if they exceed ratios below 0.75 and above 1.25. By combining the analysis of several metaphase spreads, consistent findings of gains and losses in all or almost all spreads indicate chromosomal imbalance. Chromosomal imbalances are detected either by visual inspection of fluorescence ratio (FR) profiles or by a statistical approach that compares FR measurements of the individual case with measurements of normal chromosomes. The complete analysis of one metaphase can be carried out in approximately 10 minutes.

Humans↗
PubMed2004

Quantification of cortical bone loss and repair for therapeutic evaluation in collagen-induced arthritis, by micro-computed tomography and automated image analysis.

OBJECTIVE: Ex vivo and in vivo micro-computed tomography (micro-CT) combined with a novel image analysis algorithm were used to quantify cortical bone loss and periosteal new bone formation for therapeutic evaluation in a murine model of collagen-induced arthritis. METHODS: An automated algorithm was created to locate 5 metatarsophalangeal and 3 metacarpophalangeal joints in 3-dimensional micro-CT images of mouse paws for evaluation of joint cortical bone volume (JCBV) within close proximity of the joints as well as cortical bone mineral density and periosteal new bone formation within the paws. For validation, automated estimates of JCBV were compared with radiographic visual scores (RVS) in 4 treatment groups (n = 9 per group): rat anti-mouse CD11a monoclonal antibody, methotrexate (MTX), anti-CD11a plus MTX, and saline only. In a separate study, serial images of hind limbs were evaluated in 2 treatment groups: murine tumor necrosis factor receptor II-Fc fusion protein (mTNFRII; n = 10) and control antibody (n = 7). RESULTS: Automated estimates of the JCBV were significantly correlated with the RVS (hind paws R = -0.94, front paws R = -0.81, combined R = -0.87). The anti-CD11a group had significantly higher JCBV compared with controls. In the serial study, the automated estimate of JCBV detected significant treatment effects in the mTNFRII-Fc group compared with controls. Cortical bone mineral density was significantly higher in all treatment groups compared with controls. CONCLUSION: Micro-CT combined with a novel image analysis technique (estimation of JCBV) provides a fully automated means to quantify bone destruction in a mouse model of rheumatoid arthritis.

Algorithms↗
PubMed1999

Quick-staining urinary cytology and bladder wash image analysis with an integrated risk classification: a worthwhile improvement in the follow-up of bladder cancer?

BACKGROUND: With an end toward an increase in patient quality of life, morphologic methods were tested for their combinatory value in expanding the effectiveness of follow-up appointments and finding a more specific supervision of patients with bladder cancer. METHODS: Voided urine and bladder washing specimens were gathered in 223 follow-up sessions of 124 patients with a history of bladder cancer. Hemacolor (Merck, Darmstadt, Germany)-stained cytospin preparations of voided urine specimens were ready for diagnosis within 15 minutes, and results were available shortly before cystoscopy. Feulgen-Schiff-stained cytospin preparations of bladder washings entered the image analysis system. A special software was used to classify the DNA histogram by a risk factor for bladder cancer. RESULTS: Follow-up of patients revealed 83 tumor recurrences. Depending on the grade of the underlying tumor, the sensitivity of quick-staining cytology was 86.4%, 46.2%, or 13.6% for grade 3 to grade 1 TCC, respectively. Cytology and image analysis data demonstrated complementary potency. The combination of methods increased sensitivity to 90.9%, 66.7%, and 31.8%, respectively. Although 24 of 140 image analyses denoted high risk for bladder cancer without simultaneously visible tumor, correct evidence of high risk could be found for 92.2%. CONCLUSIONS: The combinatory use of quick-staining urinary cytology and bladder wash image analysis was demonstrated to be most valuable in diagnosing recurrent bladder cancer and selecting patients needing more intensive follow-up. At a minimum of patients discomfort, the tested combination also seems helpful to surpass diagnostic limits in cystoscopy and cytology caused by therapeutic effects on the bladder epithelium. Cancer (Cancer Cytopathol)

Adolescent↗