Search

Agradecimentos: J.B.F. and K.M. participate in the Grant \#2020/09838-0 [São Paulo Research Foundation (FAPESP)]. J.B.F. has also a research grant from FAPESP (\#2020/01984-8). J.B.F., I.L.M., and K.M. have grants from the National Council for Scientific and Technological Development, Brazil (CNPq): J.B.F.: Grants \#306030/2019-5 and \#423292/2018-8; I.L.M.: Grant 305110/2018-7; and K.M.: Grant 309910/2018-8 Abstract: Experimental studies have shown that in small cell neuroendocrine lung carcinomas (SCLC) global opening of the chromatin structure is associated with a higher transcription activity and increase of tumor aggressiveness and metastasis. The study of the fractal characteristics (FD) of nuclear chromatin has been widely used to describe the cell nuclear texture and its changes correspond to changes in nuclear metabolic and transcription activity. Hence, we investigated whether the nuclear fractal dimension could be a prognostic factor in SCLC. Hematoxylin-eosin stained brush cytology slides from 49 patients with SCLC were retrieved from our files. The chromatin (FD) was calculated in digitalized and interactively segmented nuclei using a differential box-counting method. The 3,575 nuclei studied showed a bimodal distribution (peaks at FD1 = 2.115 and FD2 = 2.180). The 75 percentile of the FD was an independent unfavorable prognostic factor for overall survival when tested together with ECOG (Eastern Cooperative Oncology Group) performance status, tumor extension, and therapy in a multivariate Cox regression. Our study corroborates the concept of two main chromatin configurations in small cell neuroendocrine carcinomas and that globally more open chromatin indicates a higher risk of metastasis and therefore a shorter survival of the patient FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQ Fechado

Fractality is omnipresent in medicine and life sciences. In particular, the fractal principle is found simultaneously at different organization levels of the cell nucleus. The aim of this review is to show whether fractal characteristics of chromatin could be related to tumor pathology and pathophysiology. Areas covered: This review provides an overview of the application of fractal measurements of chromatin or DNA for the characterization of physiological or pathological processes, in particular for the detection of preneoplastic changes, the characterization of tumor progression, the differential diagnosis between neoplasms and for prognosis. We used a network-based literature research strategy, i.e. after a systematic investigation by key-words, we looked for all citations (and the citations to these citations) of the selected papers in Scopus and Webofscience. Expert opinion: The fractal dimension (FD) increases during carcinogenesis, thus permitting the diagnosis of malignancy. In various malignant tumors, a higher FD or diminished goodness-of-fit of its regression line indicates a more aggressive behavior and worse prognosis. Applying new spectral techniques, the chromatin FD can be estimated at scales below the light microscopic resolution. The latter also permits the examination of live cells and studies on field carcinogenesis and chemoprophylaxis.

J Oral Pathol Med (2010) 39: 741–746 Background: Oral lesions of lichen planus and chronic graft-vs.-host disease (cGVHD) have similar clinical and histological features, but distinct etiology. Apoptosis induced by cytotoxic T lymphocyte has been proposed as a mechanism of keratinocytes death. Cytotoxicity can be mediated by granules containing granzyme B and perforin. Since common features can reflect similarities in immunological mechanisms, we studied the role of those molecules in both diseases. Methods: We analyzed 29 cases of oral lichen planus and 27 of oral cGVHD. The sections were studied on H&E, perforin and granzyme B staining. Results: The total means (epithelium plus connective tissue number) of the granzyme B- and perforin-positive cells were significantly higher in cGVHD than in oral lichen planus lesions (P

The purpose of this study was to investigate clinical and histomorphometric features of cat skin under long-term solar exposure. Ear skin of 34 Domestic Shorthair cats that were chronically exposed to sun was classified as follows: group 0, normal ( n = 13); group 1, initial stage of photodamage (PD) ( n = 10); group 2, advanced stage of PD ( n = 11). Histologic sections were examined independently by 2 pathologists, and epidermal thickness, adnexal unit area, and dermal cellularity were assessed by morphometry. A positive correlation was obtained between age, degree of edema and sclerosis in the upper dermis, telangiectases, squamatization of basal keratinocytes, and epidermis thickness and the degree of PD. The area occupied by adnexal structures in the dermis diminished with increased PD. Dermal sclerosis and edema best separated the 3 groups. The results indicated a high level of skin hypersensitivity to sun rays in cats. The findings may be useful for clinical testing and in general veterinary pathology and dermatology.

The present work reports the synthesis, characterization and properties of magnetic iron oxide nanoparticles for biomedical applications, correlating the nanoscale tunabilities in terms of size, structure, and magnetism. Magnetic nanoparticles in different conditions were prepared through thermal decomposition of Fe(acac)3 in the presence of 1,2 hexadecanodiol (reducing agent) and oleic acid and oleylamine (ligands) in a hot organic solvent. The 2,3-dimercaptosuccinic acid (DMSA) was exchanged onto the nanocrystal surface making the particles stable in water. Nanoparticles were characterized by X-ray diffraction (XRD) measurements, small angle X-ray scattering (SAXS) and transmission electron microscopy (TEM). Preliminary tests of incorporation of these nanoparticles in cells and their magnetic resonance image (MRI) were also carried out. The magnetization characterizations were made by isothermal magnetic measurements.

Recently, a controlled double-blind study in patients with photo-aged facial skin demonstrated the beneficial role of oral intake of silanol for skin, hair and nails. The aim of our pilot study was to investigate histologic alterations in human skin after injection of silanol. Seven healthy female caucasian volunteers with a moderate degree of photoaged skin received ten sessions of weekly injections of 0.1% salicylate silanol in the left ventral lateral forearm. The histologic features of punch biopsies of the treated area and the nontreated contralateral arm were compared and the collagen and elastic fibers quantified. Texture analysis was performed on digitalized microscopic images by analyzing the Sarkar fractal dimension or amplitudes (inertia values) after Fast Fourier transformation. The treated area revealed a statistically significant increase of the density of both collagen and elastic fibers. Texture analysis showed more compact and homogeneously distributed collagen fibers after silicon injection. Our results suggest that the application of silicon may stimulate the production of collagen and elastic fibers leading to remodeling of the dermal fiber architecture, which may explain the improvement of the skin surface observed in clinical studies.

To the Editor In their interesting publication Arora et al. [1] postulate that benign thyroid nodules, such as follicular adenomas, particularly the Hurthle cell variant, but not hyperplastic nodules, might have malignant potential. Thus in the thyroid an adenoma–carcinoma sequence was postulated not only for Hurthle cell tumors [2] but also for follicular adenomas, much like that described in colon or salivary glands[3–5]. If this were the case, we would expect, in analogy to colon tumors [3], that (pre)-malignant transformations of nuclei would be more common and accentuated in larger follicular adenomas. Because epigenetic and genetic alterations related to patient prognosis may modify the chromatin texture in routine slides [3, 6–9], we tried to find out whether nuclear texture features would change with increasing size of follicular adenomas. For this purpose, we routinely reanalyzed hematoxylin & eosin-stained paraffin sections from a previous study based on the WHO Histological Classification of Tumors [10, 11]: 11 hyperplastic nodules, 18 follicular adenomas, and 24 microinvasive follicular carcinomas. Analyses were based on digitalized images of 100 randomly captured nuclei [6, 7, 9, 11–13]. We compared texture features derived from the gray value co-occurrence matrix [11–14] and the Minkowski fractal dimension [6, 11] between the three groups and then looked for correlations between texture features and the size of the nodules. Patients of all groups were of similar age with a mean of 46 years (range: 17–88 years; analysis of variance [ANOVA] p [ .0.10). The results are summarized in Table 1. Whereas the chromatin of the hyperplastic nodules is relatively homogeneous (local homogeneity) and ‘‘smooth’’ (angular second moment), its architecture in minimally invasive carcinomas is more complex (fractal dimension), with a more irregular (diagonal moment) and contrasted (entropy) chromatin arrangement. Nuclei of follicular adenomas showed intermediate texture features that were significantly correlated with the size of the nodules. In larger adenomas the entropy values (r = 0.626; p = 0.0054; Fig. 1), the fractal dimension (r = 0.482; p = 0.042; Fig. 2), and the diagonal moment (r = 0.59; p = 0.01) were increased, whereas the second angular moment (r = -0.603; p = 0.008), and local homogeneity (r = -0.627; p = 0.0053; Fig. 3) decreased. Thus the nuclear texture of smaller adenomas was more like that of hyperplastic nodules, and the chromatin of larger adenomas resembled more closely that of minimally invasive carcinomas. Nevertheless there were no significant correlations between texture and the size of hyperplastic nodules. Our results are comparable with the findings in colon tumors [3], where an increasing irregularity and loss of nuclear texture homogeneity during the adenoma–carcinoma progression was described and was supposed to be influenced by accumulated alterations in cancer-associated genes. By analogy, we believe that larger follicular adenomas might have suffered more genetic alterations than smaller ones, thus supporting the hypothesis of Arora et al. [1] positing an adenoma–carcinoma sequence for follicular K. Metze (&) R. C. Ferreira P. S. de Matos Department of Pathology, Faculty of Medicine, University of Campinas, P.O. Box 6111, 13083-887 Campinas, SP, Brazil e-mail: kmetze@fcm.unicamp.br

New insights in prognostic predictions are urgently needed for papillary thyroid carcinoma (PTC). The present study aimed to investigate whether computerized analysis of chromatin texture allows the identification of PTC patients with a poor prognosis.We randomnly selected paraffin-embedded blocks from surgical specimens of 103 classic cases of PTC. During follow-up, 68 of the patients were classified as free of disease, whereas 35 presented with recurrences. Characteristics of chromatin were obtained from digitized images of at least 100 randomly selected tumor nuclei per patient. An independent series of 30 goiters was used to validate our observations.Stage, age and distant metastases were found to serve as independent prognostic factors for survival. In addition, multivariate Cox regression confirmed variable cluster prominence as an independent prognostic factor. By comparing malignant and benign nodules, we found that the PTC lesions presented with higher nuclear perimeters, nuclear areas, Minkowski fractal dimensions, optical densities and nuclear longest chords.From our results we conclude that, in conjunction with clinical and histopathological data, morphometric data may provide relevant prognostic information in PTC patients.

Collagen fibers are an essential component of the dynamic process of scarring, which accompanies various diseases. Scar tissue may reveal different morphologic expressions, such as hypertrophic scars or keloids. Collagen fibers can be visualized by fluorescent light when stained with eosin. Second Harmonic Generation (SHG) creates a non linear signal that occurs only in molecules without inversion symmetry and is particularly strong in the collagen fibers arranged in triple helices. The aim of this study was to describe the methodology for the analysis of the density and texture of collagen in keloids, hypertrophic scars and conventional scars. Samples were examined in the National Institute of Science and Technology on Photonics Applied to Cell Biology (INFABIC) at the State University of Campinas. The images were acquired in a multiphoton microscopy LSM 780-NLO Zeiss 40X. Both signals, two-photon fluorescence (TPEF) and SHG, were excited by a Mai-Tai Ti:Sapphire laser at 940 nm. We used a LP490/SP485 NDD filter for SHG, and a BP565-610 NDD filter for fluorescence In each case, ten images were acquired serially (512×512 μm) in Z-stack and joined together to one patchwork-image . Image analysis was performed by a gliding-box-system with in-house made software. Keloids, hypertrophic scars and normal scar tissue show different collagen architecture. Inside an individual case differences of the scar process may be found between central and peripheral parts. In summary, the use of nonlinear optics is a helpful tool for the study of scars tissue.

Background Bone marrow (BM) blast count is an essential parameter for classification and prognosis of myelodysplastic syndromes (MDS). However, a high degree of cell atypias in bone marrow hemopoietic cells may be found in this group of clonal disorders, making it difficult to quantify precisely myeloblasts, and to distinguish them from promyelocytes and atypical immature myeloid precursors. Our aim was to investigate whether computerized image analysis of routine cytology would help to characterize these cells. Methods In May-Grünwald-Giemsa stained BM smears of 30 newly diagnosed MDS patients and 19 cases of normal BM, nuclei of blasts and promyelocytes were digitalized and interactively segmented. The morphological classification of the cells was done by consensus of two observers. Immature granulocytic precursors, which could not be clearly classified either as blasts or promyelocytes, were called "atypic myeloid precursors". Nuclear morphometry and texture features derived from the co-occurrence matrix and fractal dimension (FD) were calculated. Results In normal BM, when compared to myeloblasts, nuclei of promyelocytes showed significant increase in perimeter and local texture homogeneity and a decrease in form factor, chromatin gray levels, Haralick's entropy, inertia, energy, contrast, diagonal moment, cluster prominence, the fractal dimension according to Minkowski and its goodness-of-fit. Compared to normal myeloblast nuclei, the chromatin texture of MDS myeloblasts revealed higher local homogeneity and goodness-of-fit of the FD, but lower values of entropy, contrast, diagonal moment, and fractal dimension. The same differences were found between nuclei of normal promyelocytes and those of MDS. Nuclei of atypical myeloid precursors showed intermediate characteristics between those of blasts and promyelocytes according to the quantitative features (perimeter, form factor, gray level and its standard deviation), but were similar to promyelocytes according to the texture variables inertia, energy, contrast, diagonal moment, cluster prominence, and Minkowski's fractal dimension. Conclusion BM atypical immature myeloid precursors are difficult to be correctly classified in routine cytology. Although their cytoplasm is more similar to that of myeloblasts, computerized texture analysis indicates a nuclear chromatin remodeling more close to the promyelocyte, thus indicating an asynchronous intermediate maturation stage between blast and promyelocyte.

Elastic and collagen fibers are essential components of the aorta, the remodeling of these structures is accompanied with aging in various diseases and life-threatening events. While the elastic fibers confer resilience to major blood vessels collagen confers resistance to the same. Elastic fibers are easily visualized in the fluorescent light when stained with hematoxylin eosin. Second Harmonic Generation (SHG) is a non linear signal that occurs only in molecules without inversion symmetry and is particularly strong in the collagen fibers arranged in triple helices. The aim of this paper is to describe the distribution of collagen in the thickness of the thoracic aorta, and to demonstrate the distribution of between elastic fibers. The images were acquired in a multifoton microscopy and both signals, Two-phtoton excitaded fluorescence (TPEF) and SHG, were excited by a Ti:Sapphire laser. We used a band pass filter to filter the SHG signal from the TPEF signal. The thickness of the aorta varies 2-3 mm, and the image was composed of the juxtaposition of images of 220 x 220 microns. We acquired images of a histological slide of the thoracic aorta stained with picrosirius red (specific for collagen) at a wavelength of 670nm SHG subsequently acquired images with the same region and observed that the images are overlapping. Therefore, the following images were acquired by confocal microscopy (fluorescence of eosin for visualization of elastic fibers) and for collagen SHG. After reconstruction of the images, we observed the distribution of collagen along the aorta.

BackgroundThe use of computerized image analysis for the study of nuclear texture features has provided important prognostic information for several neoplasias. Recently fractal characteristics of the chromatin structure in routinely stained smears have shown to be independent prognostic factors in acute leukemia. In the present study we investigated the influence of the fractal dimension (FD) of chromatin on survival of patients with multiple myeloma.MethodologyWe analyzed 67 newly diagnosed patients from our Institution treated in the Brazilian Multiple Myeloma Study Group. Diagnostic work-up consisted of peripheral blood counts, bone marrow cytology, bone radiograms, serum biochemistry and cytogenetics. The International Staging System (ISS) was used. In every patient, at least 40 digital nuclear images from diagnostic May-Grünwald-Giemsa stained bone marrow smears were acquired and transformed into pseudo-3D images. FD was determined by the Minkowski-Bouligand method extended to three dimensions. Goodness-of-fit of FD was estimated by the R(2) values in the log-log plots. The influence of diagnostic features on overall survival was analyzed in Cox regressions. Patients that underwent autologous bone marrow transplantation were censored at the day of transplantation.Principal findingsMedian age was 56 years. According to ISS, 14% of the patients were stage I, 39% were stage II and 47% were stage III. Additional features of a bad prognosis were observed in 46% of the cases. When stratifying for ISS, both FD and its goodness-of-fit were significant prognostic factors in univariate analyses. Patients with higher FD values or lower goodness-of-fit showed a worse outcome. In the multivariate Cox-regression, FD, R(2), and ISS stage entered the final model, which showed to be stable in a bootstrap resampling study.ConclusionsFractal characteristics of the chromatin texture in routine cytological preparations revealed relevant prognostic information in patients with multiple myeloma.

Background Prognostic factors in malignant melanoma are currently based on clinical data and morphologic examination. Other prognostic features, however, which are not yet used in daily practice, might add important information and thus improve prognosis, treatment, and survival. Therefore a search for new markers is desirable. Previous studies have demonstrated that fractal characteristics of nuclear chromatin are of prognostic importance in neoplasias. We have therefore investigated whether the fractal dimension of nuclear chromatin measured in routine histological preparations of malignant melanomas could be a prognostic factor for survival. Methods We examined 71 primary superficial spreading cutaneous melanoma specimens (thickness ≥ 1 mm) from patients with a minimum follow up of 5 years. Nuclear area, form factor and fractal dimension of chromatin texture were obtained from digitalized images of hematoxylin-eosin stained tissue micro array sections. Clark's level, tumor thickness and mitotic rate were also determined. Results The median follow-up was 104 months. Tumor thickness, Clark's level, mitotic rate, nuclear area and fractal dimension were significant risk factors in univariate Cox regressions. In the multivariate Cox regression, stratified for the presence or absence of metastases at diagnosis, only the Clark level and fractal dimension of the nuclear chromatin were included as independent prognostic factors in the final regression model. Conclusion In general, a more aggressive behaviour is usually found in genetically unstable neoplasias with a higher number of genetic or epigenetic changes, which on the other hand, provoke a more complex chromatin rearrangement. The increased nuclear fractal dimension found in the more aggressive melanomas is the mathematical equivalent of a higher complexity of the chromatin architecture. So, there is strong evidence that the fractal dimension of the nuclear chromatin texture is a new and promising variable in prognostic models of malignant melanomas.

Background Th e digitalization of histologic or cytologic slides followed by computerized image analysis is becoming more popular due to technical advances in virtual microscopy and telemedicine. Because of the high information content of a digitalized slide, the application of compression methods is often a necessary step in order to reduce storage or bandwith requirements, but image compression is usually accompanied by a loss of information. Our aim was to investigate to which extent image compression according to the JPEG2000 standard is provoking alterations of image texture features.

Elastic fibers are essential components of the human aorta, and there is an association between elastin fibers remodeling and several diseases. Hypertension is one such example of a disease leading to elastin fibers remodeling. These fibers can be easily seen in eosin-hematoxilin (HE) stained histologic sections when observed by UV-excited fluorescence microscopy or by a much more precise Laser Scanning Confocal Microscope (LSCM). In order to study the effect of the hypertension on the elastin fibers pattern we developed an automatic system (software and hardware) to count the number of elastin fibers and to measure the distance between them in a LSCM and used it compare the statistical distribution of the distance between these fibers in normotensive and hypertensive patients. The full image of the whole sample (2 or 3mm long) was composed by several 220x220μm frames with 512x512 pixels. The software counters fiber and distance between fibers. We compared the elastic fiber texture in routinely HE-stained histologic slides of the aorta ascendens in 24 normotensive and 30 hypertensive adult patients of both sexes and of similar age from our autopsy files. Our results show that the average number of fibers is the same for both cases but the distance between the fibers are larger for hypertensive patients than for normotensive ones.

Entropy may be seen both from the point of view of thermodynamics and from the information theory, as an expression of system heterogeneity. Entropy, a system-specific entity, measures the distance between the present and the predictable end-stage of a biological system. It is based upon statistics of internal characteristics of the system. A living organism maintains its low entropy and reduces the entropy level of its environment due to communication between the system and its environment. Carcinogenesis is characterized by accumulating genomic mutations and is related to a loss of internal cellular information. The dynamics of this process can be investigated with the help of information theory. It has been suggested that tumor cells might regress to a state of minimum information during carcinogenesis and that information dynamics are integrally related to tumor development and growth. The great variety of chromosomal aberrations in solid tumors has limited its use as a variable to measure tumor aggressiveness or to predict prognosis. The introduction of Shannon’s entropy to express karyotypic diversity and uncertainty associated to sample distribution has overcome this problem. During carcinogenesis, mutations of the genome and epigenetic alterations (e.g. changes in methylation or protein composition) occur, which reduce the information content by increasing the randomness and raising the spatial entropy inside the nucleus. Therefore, we would expect a raise of entropy of nuclear chromatin in cytological or histological preparations with increasing malignancy of a tumor. In this case, entropy is calculated based on the co-occurrence matrix or the histogram of gray values of digitalized images. Studies from different laboratories based on various types of tumors demonstrated that entropy derived variables describing chromatin texture are independent prognostic features. Increasing entropy values are associated with a shorter survival. In summary, the entropy concept helped us to create in a parsimonious way a theoretical model of carcinogenesis, as well as prognostic models regarding survival.

OBJETIVO E MÉTODOS: Com o propósito de investigar a contribuição do exame da cromatina nuclear no diagnóstico diferencial das lesões foliculares da glândula tireoide, foram estudadas 76 amostras previamente submetidas à análise de expressão proteica de HBME-1, CK-19 e galectina-3. RESULTADOS: HBME-1 confirmou-se como o mais sensível marcador imunoistoquímico de malignidade. Uma série de variáveis morfométricas, densitométricas e de textura foram úteis na distinção entre os diferentes tipos de lesão folicular. Entre essas variáveis, o r², parâmetro relacionado à granularidade do núcleo, apresentou a melhor acurácia, sensibilidade, especificidade, valor preditivo positivo e negativo, diferenciando lesões benignas de malignas. CONCLUSÃO: A morfometria analítica de imagem da cromatina nuclear pode acrescentar acurácia ao diagnóstico diferencial das lesões de padrão folicular.

To investigate the utility of nuclear chromatin texture assessment in the differential diagnosis of follicular patterned lesions, by means of examining 76 samples previously submitted to the immunohistochemical protein analysis of HBME-1, CK-19 and galectina-3.HBME-1 confirmed to be the most sensitive marker of malignancy. A series of morphometric, densitometric and texture variables were useful in the discrimination of the different types of follicular lesions. Among these variables, r(2), a parameter related to the granularity of the nucleus presented the best accuracy, sensitivity, specificity and positive and negative predictive values, distinguishing benign from malignant lesions.The morphometric analysis of nuclear chromatin images may add accuracy to the differential diagnosis of follicular patterned lesions.

To determine if phenotypic subtypes of acute lymphoblastic leukemia (ALL) are associated with different nuclear textures.In 49 newly diagnosed patients, diagnostic work-up was made by routinely Giemsa-stained smears and immunophenotyping. B-precursor ALL was further subdivided by European Group for the Immunological Classification of Leukemias criteria. T-ALL was analyzed as a whole group. One hundred nuclear images were acquired; standard morphometric variables and texture features derived from the co-occurrence matrix were calculated.In T-ALL, nuclei presented higher mean and minimal gray levels and higher local homogeneity and angular second moment but lower entropy values, contrast, diagonal moment and cluster prominence than did nuclei in B-derived ALL. In T-ALL, peripheral blood (PB) leukocyte count showed significant positive correlation with minimal gray level and inverse correlation with nuclear area. In B-ALL, peripheral leukocyte count showed positive correlation with mean fluorescence intensity of CD45. In T-ALL but not in B-ALL, inverse correlation existed among age and PB leukocyte count and mean gray levels, and direct correlation existed with nuclear area and mean optical density.ALL of B- or T-origin presented significant differences in nuclear texture features, probably reflecting different molecular events associated with cell differentiation, gene methylation pattern, apoptosis, and lineage-specific functional events.

The regeneration of compact bone involves the deposition of a poorly organized connective tissue template that remodels into compact lamellar bone. An objective description of this process is difficult because classical histomorphometry is unable to correctly characterize qualitative changes in tissue complexity. In this study, we demonstrated the use of two distinct methods of image texture analysis, the Shannon's entropy [standard error (SE)], and the fractal dimension (FD) to characterize the formation and remodeling of newly formed compact bone within two different polyanionic collagen-elastin matrices. The matrices were implanted in defects created into parietal bones of rats. The SE and FD were calculated for histological images of the experimental groups collected 3, 7, 15, 30, 60, and 365 days postsurgery and for the original bone only at day 365. Results showed that the SE and the FD initially increased and then diminished for all groups from day 3 to day 365 approaching the values of the original bone. These results are consistent with poor tissue organization during early osteogenesis that remodels into an organized lamellar structure, showing that these methods can be valuable tools to describe bone tissue remodeling during the regeneration process of compact bones. Microsc. Res. Tech., 2008. © 2008 Wiley-Liss, Inc.

To investigate whether image analysis of routine hematoxylin-eosin (H-E) skin sections using fast Fourier transformation (FFT) could detect structural alterations in patients with Sjögren-Larsson syndrome (SLS) diagnosed by molecular biology.Skin punch biopsies of 9 patients with SLS and 17 healthy volunteers were obtained. Digital images of routine histologic sections were taken, and their gray scale luminance was analyzed by FFT. The inertia values were determined for different ranges of the spatial frequencies in the vertical and horizontal direction. To get an estimation of anisotropy, we calculated the resultant vector of the designated frequency ranges.In the prickle cell layer, SLS patients showed more intense amplitudes in spatial structures with periods between 1.2 and 3.6 microm in the vertical direction, which correlated in part with accentuated nuclei and nucleoli and perinucleolar halos in the H-E sections. In a linear discriminant analysis, the variables derived from the FFT images correctly discriminated 84.6% of the patients. Texture features derived from the gray level cooccurrence matrix were not able to separate the groups.Exploratory texture analysis by FFT was able to detect discrete alterations in the prickle cell layer in routine light microscopy slides of SLS patients. The structural changes identified by FFT may be related to abnormal cellular components associated with aberrant lipid metabolism.

The polyanionic collagen-elastin matrices (PCEMs) are osteoconductive scaffolds that present high biocompatibility and efficacy in the regeneration of bone defects. In this study, the objective was to determine if these matrices are directly mineralized during the osteogenesis process and their influence in the organization of the new bone extracellular matrix. Samples of three PCEMs, differing in their charge density, were implanted into critical-sized calvarial bone defects created in rats and evaluated from 3 days up to 1 year after implantation. The implanted PCEMs were directly biomineralized by osteoblasts as shown by ultrastructural, histoenzymologic, and morphologic analysis. The removal of the implants occurred during the bone remodeling process. The organization of the new bone matrix was evaluated by image texture analysis determining the Shannon's entropy and the fractal dimension of digital images. The bone matrix complexity decreased as the osteogenesis progressed approaching the values obtained for the original bone structure. These results show that the PCEMs allow faster formation of new bone by direct biomineralization of its structure and skipping the biomaterial resorption phase.

Background: The established pathologic criteria for minor salivary gland (MSG) involvement in chronic graft-vs.-host disease (cGVHD) could play a role in monitoring response to therapy. Methods: We evaluated MSG sequential biopsies during cGVHD therapy in 14 allogeneic bone marrow transplantation (BMT) patients. Nine patients that did not develop GVHD after BMT entered the control group. Biopsies were examined using hematoxylin-eosin, Periodic acid-Schiff (PAS) and leukocyte common antigen staining. Results: A significant loss of PAS+ acinar volume was observed at the diagnosis of cGVHD as much as at the end of treatment when compared with the control group. In the second evaluation, the inflammatory infiltrate was still greater than control group. Conclusions: The results suggest that persistent xerostomia after cGVHD treatment is because of maintenance of lymphocytic infiltrate and consequent absence of MSG secretory unit recovery. This data may be useful to provide improved insight into the histopathology of this organ involvement.

There is no consensus for grading when more than one grade is present in bladder carcinoma. We propose a grading system that considers the primary (most common) and secondary (second most common) grade of bladder cancer. Grade was correlated with stage of the tumors.We studied 293 bladder transurethral resections or radical cystectomies. Grade was considered as 1, 2 or 3 according to the 1999 World Health Organization system. The number was repeated when only one grade was seen. A final score was obtained which ranged from 2 to 6. All cases were also graded according to the highest grade area even if it was focal.According to the highest grade area, the distribution was 80 (74.07%), 27 (25.00%) and 1 (0.92%) for grade 1; 31 (24.03%), 69 (53.48%) and 29 (22.48%) for grade 2; and 0 (0%), 17 (30.35%) and 39 (69.64%) for grade 3, corresponding to the stages Ta, T1 and T2-T3, respectively. Using the system of combined numbers, grade 2 was stratified into subgroups 1 + 2 and 2 + 2 which are statistically different (p0.05) when considering stage. In grade 3, there was also a trend for statistical difference (p = 0.066) between grades 2 + 3 and 3 + 3.The grading system of combined numbers, stratifies grade 2 into subgroups 1 + 2 and 2 + 2, and grade 3 into subgroups 2 + 3 and 3 + 3 which are statistically different when considering stage. This grading system of combined numbers takes into consideration tumor heterogeneity and may be of value in prospective studies for analysis of prognosis and therapeutic response.

In their interesting contribution, Wang et al. (1) described an automated system for the diagnosis of follicular thyroid lesions, which was based on the analysis of nuclear texture features in histologic slides. According to the authors, the method was able to classify with 100% accuracy between normal thyroid tissue, follicular adenomas, and follicular carcinomas. However, the system had been trained with digitalized images of only few neoplasias, five follicular adenomas (mean lesion size of 4.8 cm), and five follicular carcinomas (a mean lesion size of 2.8 cm) as well as with images of nontumoral tissue. Recently, it had been demonstrated that in follicular adenomas the chromatin texture was size dependent, when analyzing digitalized, gray-value transformed images of nuclei in routinely hematoxylin-eosin (HE)-stained paraffin sections. In nuclei of larger adenomas, the entropy values, the fractal dimension, and the diagonal moment were significantly increased, whereas the values of the second angular moment and local homogeneity were decreased, when compared with the nuclei of smaller adenomas (2). Therefore, we would like to ask whether the considerable size differences between follicular adenomas and carcinomas in the study of Wang et al. (1) might have contributed to the extraordinary classification success claimed by the authors. To test our hypothesis, we made the following simulation study based on adenomas and carcinomas from previous studies on thyroid neoplasias in our laboratory (2,3,4). From each tumor, digitalized images of 100 randomly selected nuclei had been captured in bitmap format from routinely HE-stained 5-μm thick histologic sections (2,3). The nuclei were interactively segmented and then converted to an eight-bit gray scale by calculating the luminance. The material comprised 18 follicular adenomas and 24 microinvasive follicular carcinomas. The final diagnosis had always been done by a meticulous examination of serial step sections. From this collection, we choose a combination of eight folicular carcinomas, so that their mean diameter of 2.78 cm had approximated well with that of the carcinomas from the study of Wang and coworkers (2.8 cm) (1). Then we selected with the help of random numbers, 100 sets of eight follicular adenomas each. The mean lesion size of these random sets varied between 1.98 and 5.21 cm. If our previously mentioned hypothesis was correct, then the ability to discriminate between nuclei of adenomas and carcinomas should vary with changing diameters of the adenoma cases. We calculated nuclear texture features using variables of the gray-level co-occurrence matrix (second angular moment, entropy, energy, peak prominence, standard deviation, cluster shade, and cluster prominence) as well as Shannon's entropy of the gray level histogram and the fractal dimension according to Sarkar. All these variables had shown to be useful for texture analysis in previous studies (1,4–10). In a further step, we created 100 pairs composed of (a) always the aforementioned group of eight carcinomas with a mean diameter of 2.78 cm and (b) one of the 100 randomly choosen adenoma sets with, of course, varying mean lesion size (see Supporting Information). For each pair, we compared the nine texture features with the help of the t-test (P < 0.05 for significant differences) and recorded, for each comparison, the percentage of statistically significant texture features by plotting these data versus the mean diameter of the adenoma set in a diagram (Fig. 1). Figure 1 Box and Whiskers diagram showing relationship between mean lesion diameter of the adenoma group and the number of nuclear texture features separating significantly adenomas and carcinomas. Nine texture variables had been tested in each case. The number ... As we can easily notice, in very large adenomas nearly all nuclear texture features were significantly different from those of the carcinoma group. But these differences were rapidly vanishing, when we compared the carcinomas with smaller adenomas. With a mean adenoma lesion size of 4.8 cm, as in the study under discussion (1), approximately 80% of the texture parameters showed significant differences. However, when the mean diameters of adenomas and carcinomas were very similar (∼2.8 cm), this number had dropped below 20%. There was a highly significant direct correlation (Spearman's correlation coefficient r = 0.72; P < 0.0001) between the mean lesion size of the adenoma cases and the percentage of significant different texture features between adenomas and carcinomas. We believe that the extraordinary good discrimination results reported in the study of Wang et al. (1) might largely be based on this effect and would have been worse, if smaller adenomas had been included in the investigation. Therefore, the data presented in the study of Wang et al. (1) are not able to test the quality of the program. To get a realistic view of the diagnostic power of the proposed automated system, the authors should repeat the evaluation with a considerably larger data set, after increasing the number of adenomas and carcinomas, both comprising a large spectrum of tumor diameters.

Sir,In his interesting review article in Pathology, Tadrous1 comments on the use of the term ‘objective’ and addresses several technical and conceptual problems in image analysis. We totally agree ...

Extended abstract of a paper presented at Microscopy and Microanalysis 2009 in Richmond, Virginia, USA, July 26 – July 30, 2009

Abstract 4850 Introduction: The WHO 2008 classification of acute myeloid leukemia (AML) is based on morphology, cytogenetics and molecular features. Among them, mutations and internal tandem duplications of FLT3 in AML with a normal karyotype have been associated to a poor prognosis. Mutated NPM1 in the absence of FLT3-ITD is associated to a favorable. On the other hand, variables of nuclear chromatin texture have been described as independent risk factors in several malignancies (ALL, melanoma and multiple myeloma). Aim: To compare the influence on overall survival of the chromatin fractal dimension and molecular features in adult patients with AML. Patients and Methods: We analyzed 106 consecutive cases diagnosed at our Institution between 2007 and 2009. Diagnosis was made by bone marrow (BM) cytology and karyotype, and cases were classified by WHO criteria. Genomic DNA was extracted by phenol-chloroform. Genotyping was made with the MegaBACE 1000 equipment and analyzed in the Fragment Profiler v1.2. For detection of the FLT3-TKD mutation, genomic DNA was amplified by PCR followed by restriction analysis. Blasts from the diagnostic BM cytology were digitalized, segmented and nuclear morphometric variables were examined. Their influence on overall survival was analyzed in the Cox model. Results: Median age: 52 years; peripheral blood (PB) leukocytes: 24.0×109/l (0.7-281.3). In the univariate analysis were significant: PB leukocyte count (p=0.005), low-risk karyotype (p=0.002), FLT3 ITD+ (p=0.002), FLT3+NPM1- (p=0.029) and “goodness of fit” (R245) of the chromatin fractal dimension (Minkowski) (p=0.03). Age, fractal dimension and methylation status of p15, p16, p57, p73, ER and MDR1 were not significant. In the multivariate analyses including age, PB leukocytes, R245 and mutations, high leukocyte counts (p=0.03) and low R245 (p=0.01) were independent unfavorable and FLT3-NPM1- (p=0.04) and FLT3-NPM1+ (p=0.02) were favorable prognostic variables. Conclusions: The blast chromatin texture measured by R245 was an independent prognostic factor together with known risk variables in AML. Supported by: FAPESP and CNPq Disclosures: No relevant conflicts of interest to declare.