Galectin-3 is modulated in pancreatic cancer cells under hypoxia and nutrient deprivation.

Pancreatic ductal adenocarcinoma is one of the most aggressive tumors with a microenvironment marked by hypoxia and starvation. Galectin-3 has been evaluated in solid tumors and seems to present both pro/anti-tumor effects. So, this study aims to characterize the expression of Galectin-3 from pancreatic tumor cells and analyze its influence for cell survive and motility in mimetic microenvironment. For this, cell cycle and cell death were accessed through flow cytometry. Characterization of inside and outside Galectin-3 was performed through Real-Time Quantitative Reverse Transcription PCR (qRT-PCR), immunofluorescence, Western blot, and ELISA. Consequences of Galectin-3 extracellular inhibition were investigated using cell death and scratch assays. PANC-1 showed increased Galectin-3 mRNA expression when cultivated in hypoxia for 24 and 48 h. After 24 h in simultaneously hypoxic/deprived incubation, PANC-1 shows increased Galectin-3 protein and secreted levels. For Mia PaCa-2, cultivation in deprivation was determinant for the increasing in Galectin-3 mRNA expression. When cultivated in simultaneously hypoxic/deprived condition, Mia PaCa-2 also presented increasing for the Galectin-3 secreted levels. Treatment of PANC-1 cells with lactose increased the death rate when cells were incubated simultaneously hypoxic/deprived condition. Therefore, it is possible to conclude that the microenvironmental conditions modulate the Galectin-3 expression on the transcriptional and translational levels for pancreatic cancer cells.

Hypoxia and serum deprivation induces glycan alterations in triple negative breast cancer cells.

Triple negative breast cancer (TNBC) is a major global public health problem. The lack of targeted therapy and the elevated mortality evidence the need for better knowledge of the tumor biology. Hypoxia and aberrant glycosylation are associated with advanced stages of malignancy, tumor progression and treatment resistance. Importantly, serum deprivation regulates the invasive phenotype and favors TNBC cell survival. However, in TNBC, the role of hypoxia and serum deprivation in the regulation of glycosylation remains largely unknown. The effects of hypoxia and serum deprivation on the expression of glycosyltransferases and glycan profile were evaluated in the MDA-MB-231 cell line. We showed that the overexpression of HIF-1α was accompanied by acquisition of epithelial-mesenchimal transition features. Significant upregulation of fucosyl- and sialyltransferases involved in the synthesis of tumor-associated carbohydrate antigens was observed together with changes in fucosylation and sialylation detected by Aleuria aurantia lectin and Sambucus nigra agglutinin lectin blots. Bioinformatic analysis further indicated a mechanism by which HIF-1α can regulate ST3GAL6 expression and the relationship within the intrinsic characteristics of TNBC tumors. In conclusion, our results showed the involvement of hypoxia and serum deprivation in glycosylation profile regulation of TNBC cells triggering breast cancer aggressive features and suggesting glycosylation as a potential diagnostic and therapeutic target.

Branched Amphipathic Peptide Capsules: Different Ratios of the Two Constituent Peptides Direct Distinct Bilayer Structures, Sizes, and DNA Transfection Efficiency.

Branched amphipathic peptide capsules (BAPCs) are biologically derived, bilayer delimited, nanovesicles capable of being coated by or encapsulating a wide variety of solutes. The vesicles and their cargos are readily taken up by cells and become localized in the perinuclear region of cells. When BAPCs are mixed with DNA, the BAPCs act as cationic nucleation centers around which DNA winds. The BAPCs-DNA nanoparticles are capable of delivering plasmid DNA in vivo and in vitro yielding high transfection rates and minimal cytotoxicity. BAPCs share several biophysical properties with lipid vesicles. They are however considerably more stable-resisting disruption in the presence of chaotropes such as urea and guanidinium chloride, anionic detergents, proteases, and elevated temperature (∼95 °C). To date, all of our published results have utilized BAPCs that are composed of equimolar concentrations of the two branched sequences (Ac-FLIVI)2-K-K4-CO-NH2 and (Ac-FLIVIGSII)2-K-K4-CO-NH2. The mixture of sizes was utilized to relieve potential curvature strain in the spherical capsule. In this article, different molar ratios of the two peptides were studied to test whether alternate ratios produced BAPCs with different biological and biophysical properties. Additionally, preparation (annealing) temperature was included as a second variable.

A review of solute encapsulating nanoparticles used as delivery systems with emphasis on branched amphipathic peptide capsules.

Various strategies are being developed to improve delivery and increase the biological half-lives of pharmacological agents. To address these issues, drug delivery technologies rely on different nano-sized molecules including: lipid vesicles, viral capsids and nano-particles. Peptides are a constituent of many of these nanomaterials and overcome some limitations associated with lipid-based or viral delivery systems, such as tune-ability, stability, specificity, inflammation, and antigenicity. This review focuses on the evolution of bio-based drug delivery nanomaterials that self-assemble forming vesicles/capsules. While lipid vesicles are preeminent among the structures; peptide-based constructs are emerging, in particular peptide bilayer delimited capsules. The novel biomaterial-Branched Amphiphilic Peptide Capsules (BAPCs) display many desirable properties. These nano-spheres are comprised of two branched peptides-bis(FLIVI)-K-KKKK and bis(FLIVIGSII)-K-KKKK, designed to mimic diacyl-phosphoglycerides in molecular architecture. They undergo supramolecular self-assembly and form solvent-filled, bilayer delineated capsules with sizes ranging from 20 nm to 2 µm depending on annealing temperatures and time. They are able to encapsulate different fluorescent dyes, therapeutic drugs, radionuclides and even small proteins. While sharing many properties with lipid vesicles, the BAPCs are much more robust. They have been analyzed for stability, size, cellular uptake and localization, intra-cellular retention and, bio-distribution both in culture and in vivo.

Magnetic Parkia pendula seed gum as matrix for Concanavalin A lectin immobilization and its application in affinity purification.

The present work aimed to magnetize Parkia pendula seeds gum and use it as a matrix for Concanavalin A covalent immobilization. This composite was applied in affinity purification of glycoconjugates. Parkia pendula seeds were hydrated and the gum provenient from the supernatant was precipitated and washed with ethanol and dried. The gum was magnetized in co-precipitation using solutions of Fe+2 and Fe+3. Matrix activation was accomplished with NaIO4. Magnetized Parkia pendula seeds gum with covalently immobilized Concanavalin A was used as an affinity matrix for the recognition of bovine serum fetuin glycoprotein. Fetuin elution was carried out with a solution of glucose (300mM) and evaluated through SDS-PAGE. The efficiency of lectin immobilization and fetuin purification were 63% and 14%, respectively. These results indicate that the composite produced is a promising magnetic polysaccharide matrix for lectins immobilization. Thus, such system can be applied for affinity purification allowing an easy recovery by magnetic field.

Carbohydrate profiling of fungal cell wall surface glycoconjugates of Aspergillus species in brain and lung tissues using lectin histochemistry.

The aim of this study was to evaluate, through lectin histochemistry, the expression of N-acetyl-D-glucosamine, L-fucose, D-galactose and glucose/mannose on the cell wall surfaces of Aspergillus species in histopathological specimens of brain (n = 1) and lung (n = 6) tissues obtained during autopsy of patients diagnosed postmortem as having had invasive aspergillosis. Concanavalin A (Con A), wheat germ agglutinin (WGA), Ulex europeus agglutinin I (UEA-I) and peanut agglutinin (PNA), all conjugated with horseradish peroxidase, were employed. Lectin-binding was visualized using 3,3-diaminobendizine (DAB) and hydrogen peroxide in phosphate buffer solution (PBS). We observed expression of N-acetyl-D-glucosamine and methyl-α-D-mannoside on the cell wall surfaces of all evaluated Aspergillus species, while the expression of L-fucose and D-galactose demonstrated inter and intra-specific variations. The results obtained from this study indicate that the use of WGA and Con A lectins permits visualization of Aspergillus structures such as hyphae, conidial heads and conidia in histopathological specimens of brain and lung tissues.

Adherence of Candida albicans and Candida parapsilosis to epithelial cells correlates with fungal cell surface carbohydrates.

Many studies have described the adherence of Candida albicans to epithelial cells but little is known about Candida parapsilosis adhesion and its role in host cell surface recognition. This study was designed to evaluate the correlation between the adherence of 20 C. albicans and 12 C. parapsilosis strains to human buccal epithelial cells and the expression of fungal cell surface carbohydrates using lectin histochemistry. Adherence assays were carried out by incubating epithelial cells in yeast suspensions (10(7) cells ml(-1) ) and peroxidase conjugated lectins (Con A, WGA, UEA I and PNA at 25 µg ml(-1) ) were used for lectin histochemistry. The results showed that adherence was overall greater for C. albicans than for C. parapsilosis (P < 0.01) and that the individual strain differences correlated with a high content of cell surface α-l-fucose residues as indicated by the UEA I staining pattern. Based on the saccharide specificity of the lectins used, these results suggest that l-fucose residues on cell surface glycoconjugates may represent recognition molecules for interactions between the yeast strain studied and the host (r = 0.6985, P = 0.0045). In addition, our results indicated the presence of α-d-glucose/α-d-mannose, N-acetyl-D-glucosamine/N-acetylneuraminic acid and D-galactose/N-acetyl-D-galactosamine in fungal cell wall.

Histochemical evaluation of human prostatic tissues with Cratylia mollis seed lectin.

Lectins, proteins which selectively recognize carbohydrates, have been used in histochemistry for the evaluation of changes in glycosylation in processes of cellular differentiation and/or dedifferentiation. Cratylia mollis seed lectins (Cramoll 1,4 and Cramoll 3), conjugated to horseradish peroxidase, were used as histochemical probes in human prostate tissues: normal (NP), hyperplasia (BPH), and prostate carcinoma (PCa). The staining pattern of Con-A and Cramoll 1,4 in BPH was more intense than in NP. These lectins also showed staining differences between BPH and PCa; the latter showing decreased staining intensity with an increased degree of malignancy. PNA and Cramoll 3 stained epithelial cells similarly in all diagnoses although they did present intense staining of PCa glands lumen. Corpora amylacea were not differentially recognized by any of the lectins. Cramoll 1,4 and Cramoll 3 seed lectins present themselves as candidates for histochemical probes for prostate pathologies when compared to commercial lectins such as Con-A and PNA.

Social determinants of health associated with topical repellent use in pregnancy: a cross-sectional study during a Zika outbreak in Brazil.

Background: Repellent use during pregnancy was strongly recommended after uncovering Zika virus (ZIKV) involvement with congenital malformations. In this context, Pernambuco, Brazil played a key role since it was the epicentre for the main studies suggesting ZIKV teratogenicity and one of Brazil's most affected states during the 2014-2016 epidemics. Thus we aimed to identify possible associations between social determinants of health and repellent use in pregnancy during the ZIKV outbreak in Pernambuco. Methods: We conducted a cross-sectional study (July-December 2016) with 539 pregnant women residing in Pernambuco and estimated the associations by prevalence ratio and multivariable logistic regression. Results: Repellents were associated with pregnant women ≥30 y; graduates, employed, health professionals, private health system users and with a monthly income per person greater than two minimum wages. Women whose domiciles favour mosquitoes (ground-floor houses, intermittent water supply from general distribution or water trucks and for ≤6 d/week, cesspools/open wastewater, indoor household water storage) were less likely to use repellents. There was no association for peridomiciles. Conclusions: Repellents were not associated with ZIKV in most vulnerable pregnant women, despite all the general recommendations made during the Pernambuco epidemic. This study observed a demand for public policies focused on health, education and sanitation problems related to deprived social groups along with their co-responsibility rather than focusing on individual attitudes against mosquitoes.

Lectin staining patterns in human gastric mucosae with and without exposure to Helicobacter pylori.

The aim of the present study was to evaluate qualitative changes in the glycoconjugate expression in human gastric tissue of positive and negative patients for Helicobacter pylori, through lectins: Wheat Germ Agglutinin (WGA) and Concanavalin A (Con A). The lectins recognized differently the glycoconjugates in the superficial mucous layer at the gastric tissues. The results suggest a significant change in the carbohydrate moieties present on the surface of the gastric cells during infection.

Molecular profile of mannan-binding lectin in hepatitis C patients with MBL gene polymorphisms by a modified mannan-coated nitrocellulose assay.

The aim of this study was to develop an assay to analyze the serum profile of Mannose-binding lectin (MBL) through a simple and "in-house" method (called "dot-N-man"). Furthermore, the study attempted to associate molecular masses of MBL to the profile of MBL gene polymorphisms in patients with hepatitis C. Heterogeneity in molecular masses of MBL is due to the impairment of oligomers formation, which is linked to genetic polymorphisms in the MBL gene. Individuals with AA genotype (wild-type) produce high-molecular-mass proteins, whereas AO and OO individuals produce intermediate and low-molecular-mass proteins, respectively. Sera of thirty patients carrying the hepatitis C virus (HCV) were investigated using MBL binding assay with mannan-coated nitrocellulose (dot-N-man). Purified MBL was evaluated by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting. Dot-N-Man assay yielded MBL with molecular masses ranging between 55 and 320 kDa, comparable to low and high molecular mass forms of MBL. Nonreducing SDS-PAGE showed high molecular mass bands in all AA individuals while bands of 270 and 205 kDa were observed in sera for a number of patients with AO and OO genotypes, respectively. Immunoblotting confirmed the MBL samples obtained from the dot-N-man. These results provide new insights to understand the MBL molecular forms profile in patients infected with HCV- which could be useful in future investigations on the influence of the MBL structure/genotype on both the progression of infection and the response to hepatitis C therapy.

Glycomic profile of the human parotid gland between 18th and 26th week of fetal development.

The formation of new and functional structural components of several organs, such as parotid glands, can be influenced by the glycocode. This study analyzed the glycobiology of parotid salivary gland tissue during fetal development using specific biochemical probes (lectins and antibodies). Eleven parotid gland samples from human fetuses were obtained from spontaneous abortions at 14-28 weeks of gestation, and tissue sections were analyzed for lectin histochemistry and immunohistochemistry. From the 18th to 26th week, Canavalia ensiformis agglutinin, wheat germ agglutinin, Ulex europaeus agglutinin-I, peanut agglutinin, Sambucus nigra agglutinin, and Vicia villosa agglutinin lectin staining were predominantly observed in the apical and/or basement membranes of the ducts and tubulo-acinar units. Moreover, the presence of galectin-1 was found in the membrane, cytoplasm, and nucleus of both structures. Conversely, Gal-3 and mucin-1 were restricted to the glandular ducts. The lectin staining pattern changed during the weeks evaluated. Nevertheless, the carbohydrate subcellular localization represented a key factor in the investigation of structural distribution profiles and possible roles of these glycans in initial parotid gland development. These findings are defined by their high biological value and provide an important base for the development of subsequent studies. (J Oral Sci 58, 353-360, 2016).

Evaluation of glycophenotype in breast cancer by quantum dot-lectin histochemistry.

Cell surface glycoconjugates play an important role in differentiation/dedifferentiation processes and lectins are employed to evaluate them by several methodologies. Fluorescent probes are considered a valuable tool because of their ability to provide a particular view, and are more detailed and sensitive in terms of cell structure and molecular content. The aim of this study was to evaluate and compare the expression and distribution of glycoconjugates in normal human breast tissue, and benign (fibroadenoma), and malignantly transformed (invasive ductal carcinoma) breast tissues. For this, we used mercaptosuccinic acid-coated Cadmium Telluride (CdTe) quantum dots (QDs) conjugated with concanavalin A (Con A) or Ulex europaeus agglutinin I (UEA I) lectins to detect α-D-glucose/mannose and L-fucose residues, respectively. The QD-lectin conjugates were evaluated by hemagglutination activity tests and carbohydrate inhibition assays, and were found to remain functional, keeping their fluorescent properties and carbohydrate recognition ability. Fluorescence images showed that different regions of breast tissue expressed particular types of carbohydrates. While the stroma was preferentially and intensely stained by QD-Con A, ductal cells were preferentially labeled by QD-UEA I. These results indicate that QD-lectin conjugates can be used as molecular probes and can help to elucidate the glycoconjugate profile in biological processes.

Beta 1 integrin predicts survival in breast cancer: a clinicopathological and immunohistochemical study.

BACKGROUND: The main focus of several studies concerned with cancer progression and metastasis is to analyze the mechanisms that allow cancer cells to interact and quickly adapt with their environment. Integrins, a family of transmembrane glycoproteins, play a major role in invasive and metastatic processes. Integrins are involved in cell adhesion in both cell-extracellular matrix and cell-cell interactions, and particularly, ß1 integrin is involved in proliferation and differentiation of cells in the development of epithelial tissues. This work aimed to investigate the putative role of ß1 integrin expression on survival and metastasis in patients with breast invasive ductal carcinoma (IDC). In addition, we compared the expression of ß1 integrin in patients with ductal carcinoma in situ (DCIS). METHODS: Through tissue microarray (TMA) slides containing 225 samples of IDC and 67 samples of DCIS, ß1 integrin expression was related with several immunohistochemical markers and clinicopathologic features of prognostic significance. RESULTS: ß1 integrin was overexpressed in 32.8% of IDC. In IDC, ß1 integrin was related with HER-2 (p = 0.019) and VEGF (p = 0.011) expression and it had a significant relationship with metastasis and death (p = 0.001 and p = 0.05, respectively). Kaplan-Meier survival analysis showed that the overexpression of this protein is very significant (p = 0.002) in specific survival (number of months between diagnosis and death caused by the disease). There were no correlation between IDC and DCIS (p = 0.559) regarding ß1 integrin expression. CONCLUSIONS: Considering that the expression of ß1 integrin in breast cancer remains controversial, specially its relation with survival of patients, our findings provide further evidence that ß1 integrin can be a marker of poor prognosis in breast cancer. VIRTUAL SLIDES: The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/6652215267393871.

ConA and UEA-I lectin histochemistry of parotid gland mucoepidermoid carcinoma.

Mucoepidermoid carcinoma (MEC) corresponds to 5-12% of all salivary gland tumours, and is classified as low, intermediate or high grade. Traditionally, immunohistochemistry was considered as the complementary tool for diagnosis of salivary gland neoplasia. Lectin histochemistry has also been increasingly used in recent years. In this work, lectins were used as histochemical markers for normal and transformed parotid glands. Biopsy specimens of 15 cases diagnosed as MEC (low, intermediate and high grade) of the parotid gland were trypsin- and methanol-H(2)O(2)-treated and incubated with horseradish peroxidase (HRP)-conjugated lectins, Concanavalin A (Con A-HRP) and Ulex europeus I (UEA-I-HRP). Con A stained the neoplasic cells of MEC (all grades). In high and intermediate cases, ductal cells were weakly stained by Con A. UEA-I weakly stained normal cells of the excretory duct and neoplasic cells in high grade. Neoplasic cells in intermediate grade were moderately stained and in low grade, the cell membrane was intensely stained with UEA-I. Stroma presented a direct relation between malignancy and staining intensity for UEA-I. The results indicated that lectin histochemistry distinguished the cell biology among histological grades of MEC.

Detection of S100 protein from prostatic cancer patients using anti-S100 protein antibody immobilized on POS-PVA discs.

The S100 proteins have been extensively used as cancer biomarkers. The objectives of the present work were to immobilize the antibody anti-protein S100 to a net of semi-interpenetrated of polysiloxane and polyvinyl alcohol (POS-PVA discs), to investigate its capacity to capture S100 protein from serum and to quantify it by ELISA in sera from patients with prostatic adenocarcinoma (n = 15) and healthy individuals (n = 10). Also these values were compared to the S100 protein expression in the prostatic tissue through immunohistochemistry. The POS-PVA discs fixed about 92.8% of the offered antibody (7.75 microg of antibody per disc). The best values of the immobilized no-marked antibody anti-S100 and serum dilution were found to be 10 microg and 1:400, respectively. Optical density (OD) values for the sera of patients (0.425 +/- 0.042) with prostatic adenocarcinoma were significantly lower (P < 0.05) compared to those established for the healthy individuals (1.034 +/- 0.124). In the immunohistochemistry study no significant variations were observed in the number of positive S100 cells between prostatic adenocarcinoma (153.45 +/- 16.82) and normal prostate (147.04 +/- 18.98). These results showed a clear difference between S100 proteins expressed in tissue and presented in serum during the prostatic tissue neoplasic transformation. Sera analysis was more sensitive than immunohistochemistry S100 protein detection in the prostate tissue besides the advantage to be less invasive method.

Histochemical Localization of Carbohydrates in Morphological Stages of Developing Human Minor Salivary Glands: A Comparative Study with Cytoskeletal Markers / Localización Histoquímica de Carbohidratos en el Desarrollo de Glándulas Salivales Menores Humanas: un Estudio Comparativo con los Marcadores del Citoesqueleto

Carbohydrates play a critical role in many cellular processes like disease, growth and development. In this work lectins, proteins that recognizes carbohydrate free or conjugated, were used as histochemical probes for carbohydrates localization in developing human minor salivary gland. Immunohistochemistry for traditional cytoskeleton markers (Cks 7, 8, 13, 14, 19, SMA and Vimentin) was performed and then compared whit lectin histochemistry for PNA, WGA, ConA and UEA-I, specifics for D-galactose, N-acetyl-glucosamine, glucose/mannose and L-fucose respectively. For this, specimens were obtained from tongues and lips of 15 human foetuses at 10-28 weeks of gestation. None of immune cytoskeleton markers were identified in the first stage of development differing from carbohydrate markers. UEA-I, WGA and PNA recognized their specific carbohydrate residues in all stages analyzed varying the staining intensity and cell types. Ck8 and N-acetyl-glucosamine were expressed in canalicular, branching and cytodifferentiation stages while SMA and glucose/mannose were observed in the cytodifferentiation stage one. ConA only recognized myoepithelial cells on cytodifferentiation stages because of this specificity ConA could be used as biomarker of myoepithelial cells on cytodifferentiation. Lectin histochemistry suggests that L-fucose, D-galactose e N-acetyl-glucosamine are intensily and previously expressed than traditional cytoskeletal markers in human minor salivary gland during development.

Los hidratos de carbono tienen un papel crítico en muchos procesos celulares, como la enfermedad, el crecimiento y el desarrollo. Fueron utilizadasas lectinas, proteínas que reconocen los hidratos de carbono libres o conjugados, como sondas de localización histoquímica de los carbohidratos en el desarrollo humano de la glándula salival menor. Se realizó inmunohistoquímica de los marcadores tradicionales del citoesqueleto (CKs 7, 8, 13, 14, 19, SMA y vimentina) y posterior comparación con la histoquímica de lectinas para PNA, WGA, ConA y la UEA-I, específicas para D-galactosa, N-acetil-glucosamina, glucosa/manosa y L-fucosa, respectivamente. Para ello, se obtuvieron muestras de la lengua y de los labios de 15 fetos humanos entre 10-28 semanas de gestación. Ninguno de los marcadores inmunológicos del citoesqueleto se identificaron en la primera etapa del desarrollo, diferente de los marcadores de hidratos de carbono. UEA-I, WGA y PNA reconocen sus residuos específicos de hidratos de carbono en todas las etapas analizadas variando la intensidad de la tinción y los tipos de células. CK8 y N-acetil-glucosamina se expresaron en etapas de canalización, ramificación y citodiferenciación mientras que SMA y la glucosa/manosa se observaron solamente en la etapa de citodiferenciación. ConA sólo se reconoció en las células mioepiteliales en etapas de citodiferenciación. Así, debido a esta especificidad, ConA podría utilizarse como marcador biológico de las células mioepiteliales en la citodiferenciación. La histoquímica de lectinas sugiere que L-fucosa, D-galactosa y N-acetil-glucosamina son intensamente expresadas durante el desarrollo como los marcadores tradicionales del citoesqueleto humanos en las glándulas salivales menores .

Lectin staining patterns in human gastric mucosae with and without exposure to Helicobacter pylori / Padrões de ligação de lectinas em mucosa gástrica humana com e sem exposição a Helicobacter pylori

The aim of the present study was to evaluate qualitative changes in the glycoconjugate expression in human gastric tissue of positive and negative patients for Helicobacter pylori, through lectins: Wheat Germ Agglutinin (WGA) and Concanavalin A (Con A). The lectins recognized differently the glycoconjugates in the superficial mucous layer at the gastric tissues. The results suggest a significant change in the carbohydrate moieties present on the surface of the gastric cells during infection.

O objetivo do presente estudo foi avaliar as mudanças qualitativas na expressão de glicoconjugados em tecidos gástrico humano de pacientes infectados ou não pelo Helicobacter pylori, através das lectinas: Wheat germ agglutinin (WGA) e Concanavalina A (Con A). As lectinas reconheceram diferentemente os glicoconjugados nas camadas mucosas superficiais do tecido gástrico. Os resultados sugerem mudanças significantes nas porções de carboidratos presentes nas células gástricas durante a infecção.

Análise digital de imagens da pele avaliadas pela histoquímica com lectinas: marcador potencial para alterações bioquímicas e diagnóstico diferencial de tumores / Digital image analysis of skin neoplasms evaluated by lectin histochemistry: potential marker to biochemical alterations and tumour differential diagnosis

The present study aims to evaluate, through lectin histochemistry, the alterations in the expression of cell surface carbohydrate between benign and malignant lesions of skin using computer image analysis. Skin fragments were obtained through biopsies and diagnosed as basal cell carcinoma (BCC), epidermoid carcinoma (EpC), trichoepithelioma (TE), keratoacanthoma (KA), seborrheic keratosis (SK) and actinic keratosis (AK). Lectins Con A, WGA, PNA, UEA-I and LTA were used in histochemistry study. Image analysis was carried out in a workstation using OPTIMAS TM software system. PNA strong binding pattern to studied tumours evidenced the high expression of D-galactose residues in the epidermal neoplasms when compared to other sugars recognized by the other lectins. Among benign neoplasms, KA presented a high expression of glucose/mannose, alpha-fucose and D-galactose residues evidenced by the intense staining of Con A (94.7 percent), LTA (84.2 percent) and PNA (89.4 percent), respectively. Malignant tumours showed distinct binding patterns. EpC presented significant binding only by PNA lectin. BCC was differentially stained in comparison to the staining pattern observed in benign lesions such as TE. Qualitative (lectin histochemistry) and quantitative (digital image analysis) data obtained in this study evidenced those lectins are potential markers to biochemical alterations in skin neoplasms.

O presente estudo objetivou avaliar, através da histoquímica com lectinas, as alterações na expressão dos carboidratos da superfície celular entre lesões benignas e malignas da pele usando análise de imagens computadorizadas. Fragmentos de pele foram obtidos através de biópsias e diagnosticados como carcinoma basocelular (CBC), carcinoma epidermóide (EpC), tricoepitelioma (TE), cerato acantoma (KA), ceratose seborreica (CS) e ceratose actínica (CA). As lectinas Con A, WGA, PNA, UEA-I e LTA foram usadas no estudo histoquímico. A análise de imagens foi realizada numa estação de análise usando o sistema OPTIMAS TM de análises. A PNA tem sido largamente utilizada no estudo de tumores, evidenciando a expressão de D-galactose nas neoplasias epidérmicas; esse açúcar apresenta alta expressão quando comparado com os outros reconhecidos pelas demais lectinas. Entre as neoplasias benignas, KA apresentou alta expressão glucose/manose; resíduos de alfa-fucose e D-galactose apresentaram intensa marcação com ConA (94,7%) LTA (84,2%) e PNA (89,4 %), respectivamente. Os tumores malignos mostraram marcações distintas: EpC apresentou marcaçã significativa somente com a lectina PNA; CBC apresentou diferente padrão de marcação quando comparado ao observado nas lesõs benignas assim como no TE. Os resultados qualitativos (análise de imagens) e quantitativos (histoquímica com lectinas) desse estudo evidenciaram que as lectinas têm grande potencial como marcadores de alterações bioquímicas nas neoplasias da pele.

Altered lectin-binding sites in normal colon and ulcerative colitis

O presente trabalho objetivou, através de histoquímica com lectinas e análise digital de imagens, avaliar a expressão de carboidratos em amostras de colo normal e com colite ulcerativa. A partir de fragmentos de mucosa intestinal foram obtidos cortes histológicos (4mm) que foram incubados com lectinas (Con A, WGA, LTA e PNA), e os resultados das marcações foram avaliados através de microscopia óptica e sistema de análise de imagens. Os resultados obtidos revelaram uma intensa marcação para as células inflamatórias, principalmente neutrófilos infiltrados no tecido de reto e sigmóide, bem como células das glândulas intestinais. As lectinas WGA e LTA exibiram padrões distintos de marcação entre o epitélio normal e os casos de colite ulcerativa. As lectinas PNA e Con A falharam em reconhecer os carboidratos celulares nos casos estudados em ambos os grupos. Os resultados obtidos foram confirmados pela análise de imagem. As observações obtidas sugerem que as lectinas WGA e LTA são marcadores promissores para diferenciar o epitélio normal do padrão inflamatório da colite ulcerativa, indicando uma expressão distinta de N-acetilglicosamina e L-fucose nos respectivos casos estudados.