Computer-aided Image Analysis System Research Articles

Thyroid follicular adenomas may display features of follicular carcinoma and follicular variant of papillary carcinoma

Thyroid follicular adenomas (FA) are encapsulated tumors lacking vascular, capsular or lymphatic invasion and the typical nuclear features of papillary carcinoma (PC). However, some FA demonstrate nuclear atypia reminiscent of either follicular carcinomas (FC) or follicular variant of papillary carcinomas (FVPC), suggesting they may represent precursors of malignant transformation. We hypothesized that an objective evaluation of nuclear chromatin patterns could be used to define atypical follicular tumors (AFT) that are likely to be premalignant. To test this hypothesis, we used a computer-aided image analysis system to define the chromatin pattern of nuclei from thyroid tumors. To validate the system, we analyzed 3000 nuclei from 10 FA, 10 FC, and 10 FVPC samples and accurately distinguished between these classes of tumors. Then, we analyzed nine AFT and, in parallel, we analyzed the tumors for activating mutations of N2-RAS and over-expression of RET. The predominant chromatin pattern of AFT was of FA type in two cases, FC type in two cases, and PC type in three cases. One case contained similar numbers of FC and PC nuclei and one was comprised of a mixture of the three nuclear types. Neither RAS mutation nor RET overexpression were detected in FA. N2-RAS mutations were found in 33% of AFT, 20% of FC and 20% of FVPC without correlation with chromatin pattern. Over-expression of RET was detected in 45% of AFT, 20% of FC and 50% of FVPC and was correlated with PC nuclei. These results show that AFT are a heterogeneous group of tumors, containing genuine benign tumors and tumors that share morphological and molecular features with follicular and papillary carcinomas that might be precursors of both types of thyroid carcinomas.

Image analysis as a tool to study deteriorated cabbage (Brassica oleracea L.) seed imbibition under salt stress conditions

Cabbage seeds, aged at 15.8% moisture content and 35°C for 20d, were monitored for germination and swelling during imbibition by combining a standard germination and a salt stress integrated germination test with a computer-aided image analysis system. Exposure of seeds to -2MPa NaCl treatment from 16-24h, 8-24h and 0-24h during imbibition led to an increasing reduction in germination compared with that in a standard germination test. Both the reduction of final germination percentage and an increase of mean germination time were greater in seeds that had been aged for increasing period of time. Image analysis technique was applied to monitor both seed imbibition up to 36h, by measuring variations in seed area and the timing of germination onset under stress conditions. When seeds were transferred to NaCI at 16h or at 8h, the increase in area slowed down slightly up to 24h; upon stress removal, at 24h, a remarkable increase in seed area was detected during the first hour of water imbibition. This increase was less in deteriorated seeds, which also showed an increase in seed leachate conductivity during 24-25h imbibition. Highly significant correlations were established between germination parameters, leachate electrical conductivity and the change in seed area observed between 24 and 25h imbibition. These findings suggest that rapid image processing and recording of seed germination and size may represent an innovative technique for an accurate determination of any variation of seed hydration status. In addition, the measure of seed area may be taken as a good marker of seed vigour and tolerance to both advancing deterioration and salt stress.

The expression of matrix metalloproteinase-2 and -9 in human gliomas of different pathological grades.

Matrix metalloproteinases (MMPs) have been implicated to play a critical role in glioma invasiveness. In this study, we aimed to investigate the expression of MMP-2 and MMP-9 in human gliomas of different degrees of malignancy, and evaluated the correlation between MMP-2 and MMP-9 expression in gliomas. The samples from 65 cases of glioma were divided into four groups according to the WHO classification: there were 16 cases of grade I, 17 cases of grade II, 20 cases of grade III, and 12 cases of grade IV. Normal brain samples served as the control group, and biopsy specimens were obtained from 8 glioma patients with a needle placed into the adjacent brain 1 cm from the margin after tumor resection. All the samples were stained with hematoxylin and eosin and immunohistochemistry. A computer-aided image-analysis system was employed to measure the integral optical density (IOD) of positive slides. No positive staining was found in the control group. The positive staining was localized in the cytoplasm of glioma cells, the extracellular matrix (ECM), the basement membrane (BM), and the endothelial cells of blood vessels. Positive staining rates increased significantly when the degree of malignancy of gliomas was elevated. The IOD value of MMP-2 and MMP-9 also indicated that the intensity of MMP-2 and MMP-9 expression was elevated significantly with the degree of malignancy of the gliomas. There was a positive correlation between MMP-2 and MMP-9 expression in gliomas. Glioma invasion and angiogenesis were particularly seen in the biopsied tissues, and MMP-9 immunostaining seemed to be much more intense and extensive than MMP-2 immunostaining in these samples. These results suggest that MMP-2 and MMP-9 staining in gliomas is localized in the cytoplasm of tumor cells, BM, and endothelial cells, and that MMP-2 and MMP-9 together play an important role in the invasiveness of gliomas, mediating the degradation of the ECM and angiogenesis. MMP-2 and MMP-9 could be molecular targets in the treatment of malignant glioma.

Characterization of cellular motions through direct observation of individual cells at early stage in anchorage-dependent culture

In the monolayer culture of murine fibroblasts, the characterization of cellular motions was performed by morphological observation using a tool consisting of an optical assembly connected to a computer-aided image analysis system. This tool enabled the estimation of the projected area of the cells with sufficient accuracy, being able to follow the serial behavior of the cells on the culture surface. Trypsinization was chosen as an external factor for altering the state of the cells, and the rate of cell spreading ( r S ) and time of first cell division ( t 1 ) were evaluated by subjecting the cells to trypsin treatment for t T=3 and 15 min. During culture of the cells treated for t T=3 min , the r S values of individual cells exhibited a broad variation, ranging from 41 to 321 μm 2/h, and the average r S was 165±78 μm 2/h , which was 1.5 times larger than that of the cells treated for t T=15 min . On the contrary, the average t 1 of the cells treated for t T=3 min was 9.5 h which was y0% reduced as compared with that of the cells treated for t T=15 min . The prolonged time of trypsin treatment was considered to induce the decrease in r S and delay of the first cell division due to the requirement for the recovery from cell surface damage caused by trypsinization. The logarithmic plots of r S and t 1 were found to have an inverse relation regardless of the state of the individual cells.

Inhibition of left ventricular fibrosis by tranilast in rats with renovascular hypertension.

Growth factors such as transforming growth factor-beta (TGF beta) are believed to have an essential role in cardiac fibrosis. Tranilast (N(3,4-dimethoxycinnamoyl) anthranilic acid) attenuates the increased expression of TGF beta mRNA in vitro. To investigate whether tranilast reduces cardiac fibrosis in rats with two-kidney, one-clip (2K1C) renovascular hypertension. In addition, we tested the in-vitro effects of tranilast on cardiac myocytes and non-myocyte cells. We analysed hearts from four groups of rats: sham-operated controls; rats with 2K1C renovascular hypertension; rats with 2K1C renovascular hypertension treated for 12 weeks with the angiotensin converting enzyme (ACE) inhibitor, quinapril (6 mg/kg per day); rats with 2K1C renovascular hypertension treated for 12 weeks with tranilast (400 mg/kg per day). Systolic blood pressure was reduced after quinapril treatment. Tranilast did not alter blood pressure (2K1C: 223 +/- 19 mmHg; 2K1C + quinapril: 149 +/- 15 mmHg (P < 0.01 compared with 2K1C); 2K1C + tranilast: 204 +/- 32 mmHg). Left ventricular weight was likewise reduced significantly by quinapril, but not significantly by tranilast (2K1C: 1.52 +/- 0.2 g; 2K1C + quinapril: 1.26 +/- 0.18 g (P < 0.05 compared with 2K1C); 2K1C + tranilast: 1.37 +/- 0.27 g). Using a computer-aided image analysis system, we demonstrated that tranilast prevented cardiac fibrosis in a blood-pressure-independent manner (P < 0.01 compared with 2K1C). Determination of the cardiac hydroxyproline content similarly revealed a significant reduction in cardiac fibrosis by tranilast (2K1C: 4.92 +/- 0.48 mg/mg; 2K1C + tranilast: 3.97 +/- 0.46 mg/mg; P < 0.05). The effect of tranilast on cardiac fibrosis was comparable to the effects of a blood-pressure-decreasing dose of the ACE inhibitor, quinapril. Cell culture experiments revealed that tranilast significantly decreased the proliferation of cardiac non-myocyte cells. Proliferation of cardiac myocytes was not altered. This study revealed that long-term treatment with tranilast markedly attenuated left ventricular fibrosis in rats with renovascular hypertension. This was most probably the result of an antiproliferative effect of tranilast on cardiac non-myocyte cells. Tranilast thus offers a unique new therapeutic approach to the reduction of TGF beta-mediated cardiac fibrosis in vivo.

Morphometric characterization and classification of alpaca sperm heads using the Sperm-Class Analyzer ® computer-assisted system

Sperm morphology has been identified as one characteristic which can be useful in the prediction of sperm fertility, therefore, we hope that this study aimed at establishing standardized morphological criteria might serve in future studies dealing with the search for sperm parameters which facilitate an estimation of sperm quality. For this purpose, ejaculates from fertile alpacas were used to evaluate sperm head morphometry by means of the Sperm-Class Analyzer ® (SCA) computer-aided image analysis system. We defined three morphological categories according to sperm head size (normal 50%, small 26%, large 24%) and five categories according to sperm head shape (normal 47%, pyriform 3%, short 20%, round 1%, long 29%). Sperm classification according to shape was performed by first morphometrically characterizing sperm heads clearly falling into each of the shape categories. Thereafter, discriminant analysis was performed on the data from these typical sperm heads and the resulting classification functions were used to categorize 2200 spermatozoa from 11 alpacas. Classification of sperm heads by this method agreed in 88% of the cases with most of the misclassifications being due to pyriform heads classified as long heads. Morphometric values obtained from samples of 50, 100, 150, 175 and 200 sperm heads were compared. At least 150 sperm heads should be evaluated to overcome sample size influence on sperm measurements. Significant differences in sperm morphometry were found between individuals (CV for morphometric parameters ranging from 1.3 to 13.0) and there were marked differences in the sperm morphological composition of the ejaculates. Within-animal CV ranged from 4.7 to 17.8 thus showing the high degree of sperm polymorphism present in the alpaca ejaculate.

Characterization of Cellular Motions through Direct Observation of Individual Cells at Early Stage in Anchorage-Dependent Culture

In the monolayer culture of murine fibroblasts, the characterization of cellular motions was performed by morphological observation using a tool consisting of an optical assembly connected to a computer-aided image analysis system. This tool enabled the estimation of the projected area of the cells with sufficient accuracy, being able to follow the serial behavior of the cells on the culture surface. Trypsinization was chosen as an external factor for altering the state of the cells, and the rate of cell spreading (r(S)) and time of first cell division (t1) were evaluated by subjecting the cells to trypsin treatment for t(T)=3 and 15 min. During culture of the cells treated for t(T)=3 min, the r(S) values of individual cells exhibited a broad variation, ranging from 41 to 321 microm2/h, and the average r(S) was 165+/-78 microm2/h , which was 1.5 times larger than that of the cells treated for t(T)=15 min. On the contrary, the average t1 of the cells treated for t(T)=3 min was 9.5 h which was 60% reduced as compared with that of the cells treated for t (T)=15 min. The prolonged time of trypsin treatment was considered to induce the decrease in r(S) and delay of the first cell division due to the requirement for the recovery from cell surface damage caused by trypsinization. The logarithmic plots of r(S) and t1 were found to have an inverse relation regardless of the state of the individual cells.

CHIAS-based positioning of recombination hotspots and Giemsa bands in a multireconstructed barley karyotype

Abstract The chromosome complement of reconstructed barley karyotype PK 88 was analyzed by computer-aided Chromosome Image Analysis System (CHIAS). Fine mapping of Giemsa N-bands and regions with increased meiotic recombination activity along each individual chromosome was achieved. It was also found that CHIAS-visualized condensation profiles can be utilized as a reliable criterion for subtle differentiation of hetero- and euchromatin domains within a defined chromosomal regions. Application of CHIAS on karyotypes with distinct chromosome morphology was found to be an appropriate and reliable tool for screening of changes in chromatin compactness and its functional characteristics.

Tumor angiogenesis as a prognostic factor in thick cutaneous malignant melanoma. A quantitative morphologic analysis.

The prognostic value of the extent of neovascularization in cutaneous melanoma is a highly controversial issue. The aim of the current study was to evaluate whether the morphometric analysis of tumor vascularity may be helpful in predicting the clinical outcome of patients with thick cutaneous melanomas. A series of 15 patients with melanoma (>3 mm in thickness) who did not experience disease progression after long-term follow-up (10 years) and 30 matched controls who underwent recurrence and/or metastases were selected for the study. Microvessels were immunohistochemically stained with anti-CD31 antibody. Several parameters, including vessel number, vascular density, vessel area, equivalent circle diameter, perimeter, shape factor, compactness, and the number of vascular ramifications per 100 vessel sections, were quantitatively assessed by a computer-aided semi-automatic image analysis system. Mean vessel area was 341.69 microm2 in cases without progression and 512.55 microm2 in the progressed melanomas (P=0.008, Mann-Whitney U test). The mean equivalent circle diameter was 18.95 microm in non-progressed melanomas and 22.57 microm in progressed melanomas (P=0.009). The mean number of ramifications was 0.8 in cases without progression and 1.9 in the controls (P=0.03). Microvessel count and vascular density were higher in progressed cases (17.37 vs. 11.73 and 28.94/mm2 vs. 19.55/mm2, respectively), but the difference did not reach statistical significance (P=0.06). Our results suggest that neovascularization is a critical event in the progression of thick melanoma. Its prognostic significance is better assessed by quantification of vessel area, equivalent circle diameter, and microvessel branching, whereas microvessel count and vascular density do not provide significant prognostic information.

Facial and abdominal hair growth in hirsutism: A computerized evaluation

Methods of objectively assessing the growth rate of hairs in hirsute women have generally required some form of shaving and have focused on studying hairs affecting the face, which has reduced the number of patients willing or able to participate in such studies. A possible solution is to assess the terminal hairs on the lower abdomen (ie, the male escutcheon) because these two body areas are the most frequently affected with excess hair growth in hirsute patients. Nonetheless, it is unclear how the growth characteristics (density, diameter, and growth rate) of the hairs on the abdomen and face differ in these patients. We hypothesize that the growth characteristics of terminal hairs on the abdomen and face are similar and that evaluation of either area may be sufficient in assessing the hair growth rate of these patients. To objectively evaluate hair growth in the face and abdomen in hirsute patients, we developed a computer-aided image analysis system capable of measuring several growth parameters. Twenty hirsute women (12 white and 8 black), aged 31.2 ± 6.1 years, were studied. Facial and abdominal skin areas were shaved, and 3 to 5 days later the areas were photographed through a calibrated glass plate and 5 terminal hairs were plucked from each area. The daily hair growth rate (assessed by photography and by direct measurement of the plucked hair), the density of hairs (number of hairs per surface area assessed by photography), and hair diameter (of the plucked hairs) were determined. The extent of hirsutism was also measured, albeit subjectively, by a modification of the Ferriman-Gallwey method, with each area given a score of 0 (no terminal hairs seen) to 4 (terminal hairs in a pattern similar to that of a very hirsute man). Facial, abdominal, and total Ferriman-Gallwey scores were 1.3 ± 0.6, 1.8 ± 0.9, and 12.5 ± 5.4, respectively. Our results indicated that facial hairs were distributed in greater density and had a greater diameter than abdominal hairs (15.6 ± 14.2 hairs/cm2 vs 5.4 ± 1.9 hairs/cm2, and 84.5 ± 19.5 μm and 66.2 ± 17.5 μm, respectively, P < .005). Alternatively, the growth rates of facial and abdominal hairs were similar, whether determined photographically (0.36 ± 0.18 mm/day vs 0.43 ± 0.19 mm/day, respectively) or from plucked hairs (1.2 ± +0.2 mm/d vs 1.4 + 0.4 mm/d, respectively). We conclude that although the density and diameter of facial hairs are greater than that of lower abdominal hairs, these areas have very similar growth rates. Hence evaluation of either of the body areas, using an objective method of assessing hair growth, should provide equivalent results. (J Am Acad Dermatol 2001;45:846-50.)

The red macroalga Delesseria sanguinea as a UVB-sensitive model organism: selective growth reduction by UVB in outdoor experiments and rapid recording of growth rate during and after UV pulses

The sublittoral red alga Delesseria sanguinea was pre-cultivated in the laboratory in a predominantly green light field at 10 µmol m−2 s−1 (10 °C), with an approximately 0.5% daily increase in blade area. Such pre-cultivated blades were exposed horizontally in flow-through chambers for 5–6 days in April and May to solar radiation reduced to 19% and 11%, respectively, by neutral density screens. In all three experiments, the full solar spectrum (UVB + UVA + PAR) reduced growth rate significantly to 0–50% of values obtained in PAR alone, while this occurred with UVA + PAR in only one experiment. The growth rate of a Delesseria blade may thus be used as a sensitive and reliable biological indicator of UVB in natural solar radiation at a pre-chosen, neutral reduction level. Rapid measurements of growth rate of apical parts of Delesseria blades during and after UVB + UVA pulses of 2, 3 or 6 h duration were performed in the laboratory by measuring thallus area every 2 min by means of a CCD camera coupled to an on-line, computer-aided image analysis system. A single pulse of 2 or 3 h duration administered during the light phase caused a temporary drop in growth rate during and after the pulse, with recovery starting 2.5 h after the end of the pulse and completed by the end of the light phase. A single 6 h pulse at a biologically effective UVB dose (BEDDN A300 nm) of only 0.5 kJ m−2 reduced growth rate by 55% if administered around noon, but halted growth almost completely if supplied at night, when no photoreactivation was possible. The UVB-sensitive behaviour of Delesseria compares well with the highly sensitive phytoplankton alga Emiliania huxleyi whose growth was reported to be halted at a daily, weighted BEDDN A300 nm of 0.4 kJ m−2 administered during 4 days for 3 h in the middle of the light period.

The red macroalga Delesseria sanguinea as a UVB-sensitive model organism: selective growth reduction by UVB in outdoor experiments and rapid recording of growth rate during and after UV pulses

The sublittoral red alga Delesseria sanguinea was pre-cultivated in the laboratory in a predominantly green light field at 10 µmol m−2 s−1 (10 °C), with an approximately 0.5% daily increase in blade area. Such pre-cultivated blades were exposed horizontally in flow-through chambers for 5–6 days in April and May to solar radiation reduced to 19% and 11%, respectively, by neutral density screens. In all three experiments, the full solar spectrum (UVB + UVA + PAR) reduced growth rate significantly to 0–50% of values obtained in PAR alone, while this occurred with UVA + PAR in only one experiment. The growth rate of a Delesseria blade may thus be used as a sensitive and reliable biological indicator of UVB in natural solar radiation at a pre-chosen, neutral reduction level. Rapid measurements of growth rate of apical parts of Delesseria blades during and after UVB + UVA pulses of 2, 3 or 6 h duration were performed in the laboratory by measuring thallus area every 2 min by means of a CCD camera coupled to an on-line, computer-aided image analysis system. A single pulse of 2 or 3 h duration administered during the light phase caused a temporary drop in growth rate during and after the pulse, with recovery starting 2.5 h after the end of the pulse and completed by the end of the light phase. A single 6 h pulse at a biologically effective UVB dose (BEDDN A300 nm) of only 0.5 kJ m−2 reduced growth rate by 55% if administered around noon, but halted growth almost completely if supplied at night, when no photoreactivation was possible. The UVB-sensitive behaviour of Delesseria compares well with the highly sensitive phytoplankton alga Emiliania huxleyi whose growth was reported to be halted at a daily, weighted BEDDN A300 nm of 0.4 kJ m−2 administered during 4 days for 3 h in the middle of the light period.

Effects of Endothelin Receptor Antagonists on the Progression of Diabetic Nephropathy

Background: Diabetic nephropathy is the leading cause of end-stage renal disease in European countries and is associated with an enhanced renal synthesis of endothelin (ET)-1. ETs are – beside its potent vasoconstrictor properties – very potent profibrotic acting paracrine hormones especially in the kidney. Methods: We analyzed in rats with streptozotocin-induced diabetes the effects of an ETA-type (ETA) receptor antagonist (LU 135252) in comparison to a combined ETA/ETB receptor antagonist (LU 224332) on the expression of interstitial and glomerular collagen type I, III and IV as well as on fibronectin and laminin by quantitative immunohistochemistry using a computer-aided image analysis system. Global glomerular matrix deposition was analyzed after PAS staining. In addition to the morphometric examination of the kidneys, we also investigated GFR, urinary albumin and total protein excretion. The diabetic rats were treated for 36 weeks. Results: Treatment with either LU 135252 or LU 224332 normalized the amount of PAS-positive material within the glomeruli. The expression of glomerular fibronectin and type IV collagen was increased 36 weeks after induction of diabetes. The overexpression of these two matrix proteins within the glomeruli of diabetic rats was completely abolished by both ET receptor antagonists, whereas protein excretion was only reduced by about 50% as compared to diabetic rats without treatment. Conclusion: The present study indicates that ETA receptor antagonists as well as combined ETA/ETB receptor antagonists reduce proteinuria and completely normalize the renal matrix protein expression in hyperglycemic rats with streptozotocin-induced diabetes. The antifibrotic effect seems to be mediated via the ETA receptor. ET receptor antagonists might be a new approach in the treatment of diabetic nephropathy.

Extraction of tumor region in color images using wavelets

In this paper, a wavelet-based method is proposed to extract the tumor region from a color medical image. In the past, the diagnosis of tumors usually relied upon the tissue section stained by methylene blue. However, traditional approaches have relied primarily on manual processes and erroneous assessment may arise from subjective judgement and eye measurement. Instead of the previous method, we propose an improved radial search technique to increase the accuracy of the extraction of the tumor border. Experimental results show that the proposed method is fast and can extract the tumor region successfully. Moreover, the results of this research will be helpful in the development of a computer-aided image analysis system that will automate visual feature extraction for tumor evaluation.

Design guidelines for dealing with breakdowns and repairs in collaborative work settings

We present the results of an investigation into collaborative work within UK breast screening centres. In particular, we focus on the ways in which the organization of breast screening work and the design of artefacts such as report forms afford the detection of breakdowns—i.e. situations calling for departures from the “standard” procedures—and their safe and efficient repair. We use this to devise a framework for classifying different breakdown–repair scenarios. These scenarios are distinctive in their repair costs and impacts and can be used to highlight the implications of design decisions in collaborative work settings. Finally, we show how, via a set of derived guidelines, the results of this analysis were applied to the design of artefacts, including a user interface and computer-generated documents, for a computer-aided image analysis system intended for application in the UK breast screening programme.

Do mature pulmonary lobes grow after transplantation into an immature recipient?

Background. The use of reduced-size adult lung transplants could help solve the profound pediatric donor lung shortage. However, adequate long-term function of the mature grafts requires growth in proportion to the recipient’s development. Methods. Mature left lower lobes from adult mini-pigs (age: 7 months; mean body weight: 30 kg) were transplanted into 14-week-old piglets (mean body weight: 15 kg). By the end of the 14-week holding period, lungs of the recipients (n = 4) were harvested. After volumetric measurements, the lung morphology was studied using light microscopy, scanning, and transmission electron microscopy. Changes of alveolar airspace volume were determined using a computer aided image analysis system. Comparisons were made to age- and weight-matched controls. Results. Volumetric studies showed no significant differences ( p = 0.49) between the specific volume (mL/kg body weight) of lobar grafts and left lower lobes of adult controls. Morphologic studies showed marked structural differences between the grafts and the right native lungs of the recipients, with increased average alveolar diameter of the grafts. On light microscopy and scanning electron microscopy, alveoli appeared dilated and rounded compared to the normal polygonal shape in the controls. The computer generated semi-quantitative data of relative alveolar airspace volume tended to be higher in transplanted lobes. Conclusions. The mature pulmonary lobar grafts have filled the growing left hemithorax of the developing recipient. Emphysema-like alterations of the grafts were observed without evidence of alveolar growth in the mature lobar transplants. Thus, it can be questioned whether mature pulmonary grafts can guarantee sufficient long-term gas exchange in growing recipients.

The prognostic significance of p53 expression quantitated by computerized image analysis in epithelial ovarian cancer.

The prognostic significance of p53 expression in 316 archival epithelial ovarian cancers was assessed using a static, computer-aided image analysis system (CAS 200). Using a 10% cut-off point, 26% of primary tumors and 35% of their metastases were positive for p53 protein. p53 positivity closely correlated with tumor grade (p < 0.001), stage (p < 0.001), residual tumor (p < 0.001), serous histologic type (p = 0.005), and tumor recurrence (p = 0.007). The overall 5-year survival was 37%. In univariate survival analysis, high grade, advanced stage, older age at diagnosis, and residual tumor > 2 cm were significant predictors of poor overall survival. In both the overall (p < 0.001) and recurrence-free (p < 0.001) survival, p53 immunopositivity predicted poor prognosis. p53 expression was a significant prognostic factor of multivariate recurrence-free survival (RR 1.93, p = 0.03), but not of overall multivariate survival. In addition, p53 positivity was a marker of poor overall survival in patients with well or moderately differentiated tumors, early stage tumors, or residual tumor. Quantitation of p53 immunoexpression by CAS may offer an objective means to identify patients who need more aggressive adjuvant therapy or new treatment strategies.

Tumor angiogenesis as a prognostic factor in ovarian carcinoma

The growth of a malignant tumor requires the formation of new capillaries. Quantification of these microvessels is difficult. The purpose of this study was to establish an objective technique for quantifying angiogenesis and to evaluate whether microvessel quantity may predict tumor aggressiveness in patients with ovarian carcinoma. Endothelial area was used to quantify microvessel density in immunohistochemically stained sections of 28 International Federation of Gynecology and Obstetrics Stage IIIC ovarian carcinomas. The endothelial area was measured with a computer-aided image analysis system in the subepithelial stroma of highest vascularization. The endothelial area in the specimens of 14 patients who survived for > or =6 years was compared with that of 14 patients matched for stage and treatment who died of the disease. The mean tumor area analyzed was 5.04 +/- 0.23 mm2. The mean endothelial area per mm2 of stroma from survivors and dead patients was 0.038 +/- 0.026 mm2 and 0.110 +/- 0.034 mm2, respectively (P < 0.0001). No significant differences were found in histology, tumor grade, status of lymph nodes, and amount of residual tumor. Image analysis was used to overcome the potential subjectivity of manual counts. Computer-assisted image analysis can evaluate accurately the angiogenic potential in ovarian carcinomas. Tumor angiogenesis may prove to be a prognostic factor in patients with ovarian carcinoma. This study suggests that the measurement of the endothelial area would be clinically useful in determining microvessel density [See editorial on pages 2219-21, this issue.]

Tumor angiogenesis as a prognostic factor in ovarian carcinoma

BACKGROUND The growth of a malignant tumor requires the formation of new capillaries. Quantification of these microvessels is difficult. The purpose of this study was to establish an objective technique for quantifying angiogenesis and to evaluate whether microvessel quantity may predict tumor aggressiveness in patients with ovarian carcinoma. METHODS Endothelial area was used to quantify microvessel density in immunohistochemically stained sections of 28 International Federation of Gynecology and Obstetrics Stage IIIC ovarian carcinomas. The endothelial area was measured with a computer-aided image analysis system in the subepithelial stroma of highest vascularization. The endothelial area in the specimens of 14 patients who survived for ≥6 years was compared with that of 14 patients matched for stage and treatment who died of the disease. RESULTS The mean tumor area analyzed was 5.04 ± 0.23 mm2. The mean endothelial area per mm2 of stroma from survivors and dead patients was 0.038 ± 0.026 mm2 and 0.110 ± 0.034 mm2, respectively (P < 0.0001). No significant differences were found in histology, tumor grade, status of lymph nodes, and amount of residual tumor. CONCLUSIONS Image analysis was used to overcome the potential subjectivity of manual counts. Computer-assisted image analysis can evaluate accurately the angiogenic potential in ovarian carcinomas. Tumor angiogenesis may prove to be a prognostic factor in patients with ovarian carcinoma. This study suggests that the measurement of the endothelial area would be clinically useful in determining microvessel density [See editorial on pages 2219-21, this issue.] Cancer 1997; 80:2257-62. © 1997 American Cancer Society.

Experimental study on high-pressure droplet evaporation using microgravity conditions

Evaporation of an individual fuel droplet at high pressures and high temperatures has been studied experimentally under microgravity conditions. A suspended n -heptane droplet was used in the experiments at pressures in the range of 0.1–5.0 MPa and temperatures varying from 400 to 800 K. Temporal variations of the droplet diameter were measured with a computer-aided image analysis system. Microgravity conditions, which were produced by using 5-m and 110-m drop towers and parabolic flights, were employed to prevent natural convection that complicates the phenomena. It was observed that dense fuel vapor surrounded a droplet and the droplet surface became obscure at high pressures and high temperatures. The slope of the temporal variations of the squared droplet diameter initially increases but later becomes approximately constant at ambient pressures below the critical pressure of the fuel. At a pressure of 5.0 MPa and temperatures below the critical temperature, the slope becomes less in the latter half of the evaporation lifetime. The ratio of the initial heat-up time to the evaporation lifetime was used as a measure of unsteadiness of droplet evaporation. The ratio is almost independent of ambient temperature at an ambient pressure of 0.1 MPa, but, as ambient pressure is increased, its tendency to rise with ambient temperature becomes noticeable. Corrected evaporation lifetime t c decreases monotonically as ambient temperature is increased. The slope of its curve becomes steeper as ambient pressure increases. Dependence of t c on ambient pressure changes according to ambient temperature. Above 550 K, t c decreases as ambient pressure is increased. Below 450 K, t c tends to increase as ambient pressure is increased. It is suggested that there exists a certain ambient temperature at which ambient pressure has little effect on t c .