Chronic Continuous Exenatide Infusion Does Not Cause Pancreatic Inflammation And Ductal Hyperplasia In Non-human Primates.

In this study, we aimed to evaluate the effects of exenatide (EXE) treatment on exocrine pancreas of nonhuman primates. To this end, 52 baboons (Papio hamadryas) underwent partial pancreatectomy, followed by continuous infusion of EXE or saline (SAL) for 14 weeks. Histological analysis, immunohistochemistry, Computer Assisted Stereology Toolbox morphometry, and immunofluorescence staining were performed at baseline and after treatment. The EXE treatment did not induce pancreatitis, parenchymal or periductal inflammatory cell accumulation, ductal hyperplasia, or dysplastic lesions/pancreatic intraepithelial neoplasia. At study end, Ki-67-positive (proliferating) acinar cell number did not change, compared with baseline, in either group. Ki-67-positive ductal cells increased after EXE treatment (P = 0.04). However, the change in Ki-67-positive ductal cell number did not differ significantly between the EXE and SAL groups (P = 0.13). M-30-positive (apoptotic) acinar and ductal cell number did not change after SAL or EXE treatment. No changes in ductal density and volume were observed after EXE or SAL. Interestingly, by triple-immunofluorescence staining, we detected c-kit (a marker of cell transdifferentiation) positive ductal cells co-expressing insulin in ducts only in the EXE group at study end, suggesting that EXE may promote the differentiation of ductal cells toward a β-cell phenotype. In conclusion, 14 weeks of EXE treatment did not exert any negative effect on exocrine pancreas, by inducing either pancreatic inflammation or hyperplasia/dysplasia in nonhuman primates.

Diagnostic underestimation of atypical ductal hyperplasia and ductal carcinoma in situ at percutaneous core needle and vacuum-assisted biopsies of the breast in a Brazilian reference institution

Abstract Objective: To determine the rates of diagnostic underestimation at stereotactic percutaneous core needle biopsies (CNB) and vacuum-assisted biopsies (VABB) of nonpalpable breast lesions, with histopathological results of atypical ductal hyperplasia (ADH) or ductal carcinoma in situ (DCIS) subsequently submitted to surgical excision. As a secondary objective, the frequency of ADH and DCIS was determined for the cases submitted to biopsy. Materials and Methods: Retrospective review of 40 cases with diagnosis of ADH or DCIS on the basis of biopsies performed between February 2011 and July 2013, subsequently submitted to surgery, whose histopathological reports were available in the internal information system. Biopsy results were compared with those observed at surgery and the underestimation rate was calculated by means of specific mathematical equations. Results: The underestimation rate at CNB was 50% for ADH and 28.57% for DCIS, and at VABB it was 25% for ADH and 14.28% for DCIS. ADH represented 10.25% of all cases undergoing biopsy, whereas DCIS accounted for 23.91%. Conclusion: The diagnostic underestimation rate at CNB is two times the rate at VABB. Certainty that the target has been achieved is not the sole determining factor for a reliable diagnosis. Removal of more than 50% of the target lesion should further reduce the risk of underestimation.

Spectrum of carcinoembryonic antigen immunoreactivity from isolated ductal hyperplasias to atypical hyperplasias associated with infiltrating ductal breast cancer

Aims - To study the immunohistochemical expression of carcinoembryonic antigen (CEA) in ductal hyperplasia of the breast and to investigate its putative relation with atypia and co-existing infiltrating ductal carcinoma.Methods - Paraffin wax embedded tissue from 37 cases of isolated ductal hyperplasia (five with atypia and 32 without atypia) and 25 cases of ductal hyperplasia associated infiltrating ductal carcinoma (IDC) (seven with atypia and 18 without atypia) was stained with a monoclonal anti-CEA antibody using a standard avidin biotin immunoperoxidase method.Results - CEA immunoreactivity was observed in eight (12.8%) ductal hyperplasia cases. The percentage of CEA positivity in ductal hyperplasia cases with atypia (33.3%) was substantially higher than that observed in cases of ductal hyperplasia without atypia (8.0%). Six cases of ductal hyperplasia associated IDC reacted with CEA; in these six cases the neoplastic cells of the co-existing carcinoma were also CEA positive. The percentage of CEA immunoreactivity in ductal hyperplasia associated IDC was higher than that observed in isolated ductal hyperplasia (24.0 v 5.4%). The percentage of CEA immunoreactivity in atypical ductal hyperplasia associated IDC was similar to that observed in IDC alone (42.9 v 40.0%).Conclusions-The presence of CEA immunoreactivity has been confirmed in benign proliferative breast lesions. The prevalence of such immunoreactivity increases from 3.1% in isolated, nonatypical ductal hyperplasia to 42.9% in atypical ductal hyperplasia associated IDC. This finding and the similarity of the frequency of CEA positivity in atypical ductal hyperplasia associated IDC and in IDC alone suggests that there is a pathogenetic link between ductal hyperplasia and some types of breast cancer.

Imunoexpressão do c-erbB-2 nas lesões epiteliais proliferativas intraductais da mama de mulheres

OBJETIVOS: Alterações genéticas são relacionadas à gênese e progressão do câncer. Neoplasias de vários órgãos expressam o oncogene c-erbB-2. Nas proliferações intraductais da mama tem sido avaliado como fator de risco para o desenvolvimento de câncer. Foram avaliadas a imunoexpressão do c-erbB-2 em lesões epiteliais proliferativas intraductais e as possíveis correlações com características anatomopatológicas do carcinoma ductal in situ (CDIS). MÉTODOS: Foi utilizado material de arquivo, amostras teciduais fixadas em formalina e incluídas em blocos de parafina de 88 mulheres. Destas, 51 com CDIS e 37 com hiperplasia ductal sem atipias (HDT). A idade variou de 35 a 76 anos. Revisados todos os casos, verificou-se: o grau nuclear, a presença de necrose, o subtipo histológico predominante e sua extensão. Obteve-se material suficiente para o estudo imunohistoquímico do c-erbB-2 de 84 sujeitos do estudo. RESULTADOS: Não foi observada a expressão do oncogene nas hiperplasias sem atipias e nos tecidos adjacentes a todas amostras teciduais. A expressão do c-erbB-2 foi verificada em nove (19,1%) dos CDIS (p= 0,0001). A imunoexpressão não se relacionou à extensão das lesões. A imunoexpressão do c-erbB-2 no CDIS correlacionou-se com subtipo histológico (p=0,019), com a presença de necrose (p=0,0066), com o grau nuclear (p=0,0084) e com a Classificação de Van Nuys (p=0,039). CONCLUSÕES: A expressão do c-erbB-2 foi estatisticamente significante nas lesões proliferativas de risco (CDIS) e correlacionou-se com características histopatológicas: alto grau nuclear, presença de necrose, subtipo comedo. Não houve expressão nas hiperplasias sem atipias e tecidos adjacentes.

Anatomo-histopatologia de fígados bovinos: relação entre as lesões e os sistemas de produção

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

14-3-3 zeta overexpression in early stage breast disease and tumor progression

Recent progress in diagnostic tools allows many breast cancers to be detected at an early pre-invasive stage. Thus, a better understanding of the molecular basis of early breast cancer progression is essential. 14-3-3 is a family of highly conserved and ubiquitously expressed proteins that are expressed in all eukaryotic organisms. In mammals there are seven isoforms, which bind to phosphor-serine/threonine residues regulating essential cellular processes such as signal transduction, cell cycle progression, and apoptosis. Our laboratory has discovered that a particular 14-3-3 family member, Zeta, is overexpressed in over 40% of breast tumor tissues. Furthermore, I examined the stage of breast disease in which 14-3-3ζ overexpression occurs and found that increased expression of 14-3-3ζ begins at the stage of atypical ductal hyperplasia, a very early stage of breast disease that confers increased risk for progress toward breast cancer. To determine whether 14-3-3ζ overexpression is a decisive early event in breast cancer, I overexpressed 14-3-3ζ in MCF10A cells, a non-transformed mammary epithelial cell (MEC) line and examined its impact on acini formation in a three dimensional (3D) culture model which simulates a basic unit of structure in the mammary gland. I discovered that 14-3-3ζ overexpression severely disrupted the acini architecture resulting in the disruption of polarity and luminal filling. Both are critical morphological events in the pre-neoplastic breast disease. This thesis focuses on the molecular mechanism of luminal filling. Proper lumen formation is a result of anoikis, a specific type apoptosis of cells not attached to the basement membrane. I found that 14-3-3ζ overexpression conferred a resistance to anoikis. Additionally, 14-3-3ζ overexpression in MCF10A cells and in MECs from 14-3-3ζ transgenic mice reduced expression of p53, which is known to mediate anoikis. Mechanistically, 14-3-3ζ induced hyperactivation of the PI3K/Akt pathway which led to phosphorylation and translocation of the MDM2 to the nucleus resulting in increased p53 degradation. Ectopic expression of p53 restored luminal apoptosis in 14-3-3ζ overexpressing MCF10A acini in 3D cultures. These data suggest that 14-3-3ζ overexpression is a critical event in early breast disease and down-regulation of p53 is one of the mechanisms by which 14-3-3ζ alters MEC acini structure and may increase the risk of progression to breast cancer. ^

Breast cancer risk with aromatase inhibition and phytoestrogen-free diet

In this thesis a mouse model was used to examine the effect of pubertal estrogen inhibition and a phytoestrogen-free diet on the development of mammary glands. The study question was does treatment with aromatase inhibitor during puberty increase susceptibility to breast cancer among cohorts that consumed a diet free of phytoestrogens. The study design consisted of a cohort of mice treated with aromatase inhibitor, letrozole, during puberty and a vehicular group that was used as a control. Both groups were fed a diet free of phytoestrogens from the time of weaning until sacrifice during adulthood. The study aimed to assess mammary gland development in terms of breast cancer risk. The methods employed in this research included morphological and histological analysis of mammary glands, as well as estradiol, RNA and protein analysis. The main finding of the study was that mice exposed to aromatase inhibitor during puberty developed mammary glands with specific characteristics suggestive of vulnerability to oncogenesis such as increased lateral branching, increased number of glands, increase ductal hyperplasia, and diminished expression of TGFβ and p27 protein levels. The conclusions suggest that puberty is a critical period in which the mammary gland is susceptible to environmental threats that may result in deleterious epigenetic effects leading to an increased breast cancer risk in adulthood. This study has several public health implications; the most significant is that environmental threats during puberty may result in adverse mammary gland development and that phytoestrogen sources in the diet are necessary for normal maturation of the mammary glands.^

Mammary tumor suppression by transforming growth factor beta 1 transgene expression.

In cell culture, type alpha transforming growth factor (TGF-alpha) stimulates epithelial cell growth, whereas TGF-beta 1 overrides this stimulatory effect and is growth inhibitory. Transgenic mice that overexpress TGF-alpha under control of the mouse mammary tumor virus (MMTV) promoter/enhancer exhibit mammary ductal hyperplasia and stochastic development of mammary carcinomas, a process that can be accelerated by administration of the chemical carcinogen 7,12-dimethylbenz[a]anthracene. MMTV-TGF-beta 1 transgenic mice display mammary ductal hypoplasia and do not develop mammary tumors. We report that in crossbreeding experiments involving the production of mice carrying both the MMTV-TGF-beta 1 and MMTV-TGF-alpha transgenes, there is marked suppression of mammary tumor formation and that MMTV-TGF-beta 1 transgenic mice are resistant to 7,12-dimethylbenz[a]anthracene-induced mammary tumor formation. These data demonstrate that overexpression of TGF-beta 1 in vivo can markedly suppress mammary tumor development.

Molecular evolution of breast cancer

Molecular analysis of invasive breast cancer and its precursors has furthered our understanding of breast cancer progression. In the past few years, new multi-step pathways of breast cancer progression have been delineated through genotypic-phenotypic correlations. Nuclear grade, more than any other pathological feature, is strongly associated with the number and pattern of molecular genetic abnormalities in breast cancer cells. Thus, there are two distinct major pathways to the evolution of low- and high-grade invasive carcinomas: whilst the former consistently show oestrogen receptor (ER) and progesterone receptor (PgR) positivity and 16q loss, the latter are usually ER/PgR-negative and show Her-2 over-expression/amplification and complex karyotypes. The boundaries between the evolutionary pathways of well-differentiated/low-grade ductal and lobular carcinomas have been blurred, with changes in E-cadherin expression being one of the few distinguishing features between the two. In addition, lesions long thought to be precursors of breast carcinomas, such as hyperplasia of usual type, are currently considered mere risk indicators, whilst columnar cell lesions are now implicated as non-obligate precursors of atypical ductal hyperplasia (ADH) and well-differentiated ductal carcinoma in situ (DCIS). However, only through the combination of comprehensive morphological analysis and cutting-edge molecular tools can this knowledge be translated into clinical practice and patient management. Copyright (C) 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley Sons, Ltd.

Modelo experimental de lesões intra-epiteliais e de adenocarcinoma ductal pancreático induzidos por 7,12-dimetilbenzantraceno em camundongos

INTRODUÇÃO: O adenocarcinoma de pâncreas apresenta um mau prognóstico. A utilização de modelos experimentais é necessária para a compreensão do comportamento biológico tumoral, principalmente das lesões precoces (neoplasias intra-epiteliais pancreáticas - NIPan) e para o desenvolvimento de opções terapêuticas. OBJETIVO: Avaliar a carcinogênese pancreática induzida por 7,12-dimetilbenzantraceno (DMBA), em camundongos, aplicando a classificação das neoplasias intra-epiteliais pancreáticas. MÉTODOS: 90 camundongos machos, mus musculus, da cepa CF1, foram submetidos à laparotomia mediana e 1 mg de DMBA foi implantado na porção cefálica do pâncreas. Os animais foram divididos em dois grupos, com eutanásia em 30 e 60 dias. Em seguida, o pâncreas foi retirado, fixado em formalina e foram confeccionadas lâminas coradas com hematoxilina eosina. Os cortes histológicos foram avaliados por dois patologistas de acordo com os seguintes critérios: pâncreas normal, hiperplasia reacional, NIPan 1A, NIPan 1B, NIPan 2, NIPan 3 e carcinoma. As alterações inflamatórias também foram analisadas. RESULTADOS: A avaliação patológica evidenciou, no grupo de 30 dias: 4 (16,7%) animais com hiperplasia reativa, 16 (66,6%) com NIPan e 4 (16,7%) com adenocarcinoma. No grupo de 60 dias: 10 (27,1%) animais com hiperplasia reativa, 13 (35,1%) com NIPan e 14 (37,8%) com adenocarcinoma. A diferença entre os grupos apresentou significância estatistística (P < 0,05 – teste exato de Fisher). A prevalência de alterações inflamatórias em 30 dias foi: pancreatite aguda (n=11), pancreatite crônica (n=5) e inflamação dependente da bolsa (n=8). No grupo de 60 dias 11 espécimes apresentavam pancreatite aguda e 26 pancreatite crônica. CONCLUSÕES: O modelo experimental com DMBA em camundongos, induz neoplasia intra-epitelial pancreática e adenocarcinoma ductal histologicamente semelhantes ao carcinoma pancreático em humanos. Este modelo pode ser utilizado na investigação da carcinogênese com enfoque na progressão molecular das lesões precursoras até o adenocarcinoma.

Pseudoangiomatous hyperplasia of mammary stroma associated with gynaecomastia

Aims-To evaluate the prevalence of pseudoangiomatous hyperplasia of mammary stroma in gynaecomastia and its immunohistochemical profile in this setting.Methods-Eighty eight cases of gynaecomastia recovered from the files of the department of pathology, Botucatu School of Medicine from 1976 to 1996 were studied. In the cases associated with pseudoangiomatous hyperplasia of mammary stroma, immunoreactivity for cytokeratins (CAM 5.2), vimentin, CD34, factor VIII related antigen, and the oestrogen and progesterone receptors were studied.Results-Pseudoangiomatous hyperplasia of mammary stroma was found in 21 of 88 cases of gynaecomastia (23.8%). In all cases, the cells lining the spaces were positive for vimentin, whereas CAM 5.2 and factor VIII related antigen were consistently negative. Nineteen of the 21 cases showed immunoreactivity for CD34. Ductal epithelial cells were positive for both the oestrogen receptor and the progesterone receptor, whereas stromal cells were negative.Conclusions-Pseudoangiomatous hyperplasia of mammary stroma was present in approximately one quarter of the cases of gynaecomastia. This immunohistochemical study confirms the mesenchymal origin of the stromal cells that line the pseudovascular spaces, as has been found in female cases of pseudoangiomatous hyperplasia of mammary stroma.

Repercussions of castration and vasectomy on the ductal system of the rat ventral prostate

Diseases. such as cancer and benign prostatic hyperplasia, are related to disruption of the mechanism regulating the balance between cell proliferation and apoptosis in prostatic cells. Since castration and vasectomy might alter that balance, this study evaluates the cell proliferation, apoptosis and height of the secretory epithelium of the ventral-prostate ductal system post-castration and vasectomy. Immunohistochemical (PCNA and Ki67), cytochemical (Fuelgen reaction) and morphometric investigation have been carried out. Cell proliferation indices decreased significantly in both regions of the ventral-prostate ductal system after castration compared to the sham-operated group. The apoptotic index increased significantly after 48 h, declining 7 days post-castration. The cell proliferation indices did not differ after 48 h significantly; however, they increased 7 days post-vasectomy in both regions. The apoptotic index did not differ significantly in either time post-vasectomy. Castration caused an imbalance in favor of apoptosis, whereas vasectomy caused an imbalance in favor of cell proliferation. (c) 2005 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.

Shorter CAG repeat in the AR gene is associated with atypical hyperplasia and breast carcinoma

Background: Previous reports into the role of [CAG]n repeat lengths in the androgen receptor (AR) gene indicate that these may play an important part in the development and progression of breast cancer, however, knowledge regarding benign breast lesions is limited. Patients and Methods: PCR-based GeneScan analysis was used to investigate the [CAG]n repeat length at exon 1 of the AR gene in 59 benign breast lesions (27 fibroadenomas, 18 atypical hyperplasias, and 14 hyperplasias without atypia) and 54 ductal breast carcinomas. Seventy-two cancer-free women were used as a control group. In addition, [CAG]n repeats were evaluated for the presence of loss of heterozygosity (LOH) and microsatellite instability (MSI) in a subset of these samples (27 fibroadenomas, 14 hyperplasias without atypia and 22 breast carcinomas). Results: Shorter [CAG]n repeat lengths were strongly correlated with atypical hyperplasias (p=0.0209) and carcinomas (p<0.0001). LOH was found in 1/12 and 4/20 informative cases of hyperplasias without atypia and breast carcinomas, respectively. Three patients with breast carcinoma who had previously presented atypical hyperplasia showed a reduction in the [CAG]n repeat length in their carcinomas. Conclusion: Short [CAG]n repeat length (≤20) polymorphisms are strongly associated with breast carcinomas and atypical hyperplasias. Although non-significant, a subgroup of patients with breast carcinoma and genotype SS showed an association with parameters of worse outcome.

Impact Of Benign Prostatic Hyperplasia Pharmacological Treatment On Transrectal Prostate Biopsy Adverse Effects.

Background. Benign prostatic hyperplasia (BPH) pharmacological treatment may promote a decrease in prostate vascularization and bladder neck relaxation with theoretical improvement in prostate biopsy morbidity, though never explored in the literature. Methods. Among 242 consecutive unselected patients who underwent prostate biopsy, after excluding those with history of prostate biopsy/surgery or using medications not for BPH, we studied 190 patients. On the 15th day after procedure patients were questioned about symptoms lasting over a week and classified according to pharmacological BPH treatment. Results. Thirty-three patients (17%) were using alpha-blocker exclusively, five (3%) 5-alpha-reductase inhibitor exclusively, twelve (6%) patients used both medications, and 140 (74%) patients used none. There was no difference in regard to age among groups (P = 0.5). Postbiopsy adverse effects occurred as follows: hematuria 96 (50%), hematospermia 53 (28%), hematochezia 22 (12%), urethrorrhagia 19 (10%), fever 5 (3%), and pain 20 (10%). There was a significant negative correlation between postbiopsy hematuria and BPH pharmacological treatment with stronger correlation for combined use of 5-alpha-reductase inhibitor and alpha-blocker over 6 months (P = 0.0027). Conclusion. BPH pharmacological treatment, mainly combined for at least 6 months seems to protect against prostate biopsy adverse effects. Future studies are necessary to confirm our novel results.

Structural aspects of the p.P222Q homozygous mutation of HSD3B2 gene in a patient with congenital adrenal hyperplasia

Type II 3β-hydroxysteroid dehydrogenase/Δ5-Δ4-isomerase (3β-HSD2), encoded by the HSD3B2 gene, is a key enzyme involved in the biosynthesis of all the classes of steroid hormones. Deleterious mutations in the HSD3B2 gene cause the classical deficiency of 3β-HSD2, which is a rare autosomal recessive disease that leads to congenital adrenal hyperplasia (CAH). CAH is the most frequent cause of ambiguous genitalia and adrenal insufficiency in newborn infants with variable degrees of salt losing. Here we report the molecular and structural analysis of the HSD3B2 gene in a 46,XY child, who was born from consanguineous parents, and presented with ambiguous genitalia and salt losing. The patient carries a homozygous nucleotide c.665C>A change in exon 4 that putatively substitutes the proline at codon 222 for glutamine. Molecular homology modeling of normal and mutant 3β-HSD2 enzymes emphasizes codon 222 as an important residue for the folding pattern of the enzyme and validates a suitable model for analysis of new mutations.