Raphael Salles S. Medeiros

Biological Applications of a Chimeric Probe for the Assessment of Galectin-3 Ligands:

β1–6 branching of N-linked oligosaccharides has been correlated with the progression of different cancers. The leukoagglutinins of Phaseolus vulgaris (L-PHA) have been used to study this pattern of glycosylation whose biological significance is incompletely understood. The animal lectin, galectin-3, also binds to structures recognized by L-PHA. To develop a functional tool for the in situ identification of this pattern of glycosylation, human galectin-3 was fused to bacterial alkaline phosphatase (gal3/AP). Gal3/AP recognized both A and B blood group saccharides (B>A) and lactosamine derivatives. Gal3/AP recognition depended at least in part on the N-linked oligosaccharides of different glycoproteins. The presence and distribution of galectin-3 ligands were analyzed in both murine and human normal and tumor samples. Loss of apical expression of galectin-3 ligands was commonly found in carcinomas. Endothelial and inflammatory cells were enriched in galectin-3 ligands as compared with tumor cells; thus, gal3/AP is a suitable tool for studying tumor micro-environments. Comparative analysis of both gal3/AP and L-PHA binding patterns indicated that although similar, these patterns are not identical. The probe developed was useful for several immunoenzymatic assays and will allow the physiological and clinical significance of the expression pattern of galectin-3 ligands to be established. This manuscript contains online supplemental material at http:/www.jhc.org. Please visit this article online to view these materials. (J Histochem Cytochem 55: 1015–1026, 2007)

Human Cytomegalovirus DNA Quantification and Gene Expression in Gliomas of Different Grades

Gliomas are the most common type of primary brain tumors. The most aggressive type, Glioblastoma multiforme (GBM), is one of the deadliest human diseases, with an average survival at diagnosis of about 1 year. Previous evidence suggests a link between human cytomegalovirus (HCMV) and gliomas. HCMV has been shown to be present in these tumors and several viral proteins can have oncogenic properties in glioma cells. Here we have investigated the presence of HCMV DNA, RNA and proteins in fifty-two gliomas of different grades of malignancy. The UL83 viral region, the early beta 2.7 RNA and viral protein were detected in 73%, 36% and 57% by qPCR, ISH and IHC, respectively. Positivity of the viral targets and viral load was independent of tumor type or grade suggesting no correlation between viral presence and tumor progression. Our results demonstrate high prevalence of the virus in gliomas from Brazilian patients, contributing to a better understanding of the association between HCMV infection and gliomas worldwide and supporting further investigations of the virus oncomodulatory properties.

Chordoid glioma: Case report and review of the literature

Highlights • We reported the 80th case of chordoid glioma and reviewed the literature.• Clinical outcomes reported have been poor.• If possible, efficient treatment depends upon radical surgical resection, however partial resection with adjuvant radiosurgery can be the most recommend due to local tumor and morbid-mortality relation.• No chemotherapeutic regimen has been shown to be effective for CG.

Guidelines for the management of neuroendocrine tumours by the Brazilian gastrointestinal tumour group

Neuroendocrine tumours are a heterogeneous group of diseases with a significant variety of diagnostic tests and treatment modalities. Guidelines were developed by North American and European groups to recommend their best management. However, local particularities and relativisms found worldwide led us to create Brazilian guidelines. Our consensus considered the best feasible strategies in an environment involving more limited resources. We believe that our recommendations may be extended to other countries with similar economic standards.

Dendritic skin cells

Dendritic cells (DCs) are the most potent antigen-presenting cells of the immune system. To become potent T-cell stimulators, DCs have to mature. Immature DCs reside in peripheral tissues. With antigen uptake and exposure to infl ammatory stimuli, they migrate to peripheral lymph nodes where, as mature DCs, they express additional molecules that can induce T-cell stimulation.

Cell internalization of 7-ketocholesterol-containing nanoemulsion through LDL receptor reduces melanoma growth in vitro and in vivo : a preliminary report

Oxysterols are cholesterol oxygenated derivatives which possess several biological actions. Among oxysterols, 7-ketocholesterol (7KC) is known to induce cell death. Here, we hypothesized that 7KC cytotoxicity could be applied in cancer therapeutics. 7KC was incorporated into a lipid core nanoemulsion. As a cellular model the murine melanoma cell line B16F10 was used. The nanoparticle (7KCLDE) uptake into tumor cells was displaced by increasing amounts of low-density-lipoproteins (LDL) suggesting a LDL-receptor-mediated cell internalization. 7KCLDE was mainly cytostatic, which led to an accumulation of polyploid cells. Nevertheless, a single dose of 7KCLDE killed roughly 10% of melanoma cells. In addition, it was observed dissipation of the transmembrane potential, evidenced with flow cytometry; presence of autophagic vacuoles, visualized and quantified with flow cytometry and acridine orange; and presence of myelin figures, observed with ultrastructural microscopy. 7KCLDE impaired cytokenesis was accompanied by changes in cellular morphology into a fibroblastoid shape which is supported by cytoskeletal rearrangements, as shown by the increased actin polymerization. 7KCLDE was injected into B16 melanoma tumor-bearing mice. 7KCLDE accumulated in the liver and tumor. In melanoma tumor 7KCLDE promoted a >50% size reduction, enlarged the necrotic area, and reduced intratumoral vasculature. 7KCLDE increased the survival rates of animals, without hematologic or liver toxicity. Although more pre-clinical studies should be performed, our preliminary results suggested that 7KCLDE is a promising novel preparation for cancer chemotherapy.

Expression of ERCC1, Bcl-2, Lin28a, and Ki-67 as biomarkers of response to first-line platinum-based chemotherapy in patients with high-grade extrapulmonary neuroendocrine carcinomas or small cell lung cancer

Background Small cell lung cancer (SCLC) and high-grade extrapulmonary neuroendocrine carcinomas (EPNEC) share similar histopathological features and treatment, but outcomes may differ. We evaluated in our study the expression of biomarkers associated with response rate (RR) to chemotherapy and overall survival (OS) for these entities. Materials and Methods This is a multicentre retrospective analysis of advanced EPNEC and SCLC patients treated with platinum-based chemotherapy. Paraffin-embedded tumour samples were reviewed by a single pathologist and tested for immunohistochemistry (IHC) expression of Ki-67, ERCC1, Bcl-2, and Lin28a. All images were evaluated by the same radiologist and RR was determined by RECIST 1.1. Results From July, 2006 to July, 2014, 142 patients were identified, being 82 (57.7%) SCLC and 60 (42.3%) EPNEC. Clinical characteristics and median Ki-67 (SCLC: 60%; EPNEC: 50%; p = 0.86) were similar between the groups. RR was higher for SCLC patients (86.8% versus 44.6%; p<0.001), but median OS was similar (10.3 months in SCLC and 11.1 months in EPNEC; HR 0.69, p = 0.07). Bcl-2 expression was higher in SCLC patients (46.3% versus 28.3%, p = 0.03) and was associated with worse prognosis in EPNEC (median OS 8.0 months versus 14.7 months; HR 0.47, p = 0.02). Conclusion EPNEC patients presented inferior RR to platinum-based chemotherapy than SCLC but tended to live longer. Neither ERCC1, Lin28, or Ki-67 were prognostic or predictive for RR in EPNEC or SCLC. High Bcl-2 expression was associated with poor prognosis in EPNEC patients.

Leukoencephalopathy resolution after atypical mycobacterial treatment: a case report

BackgroundAssociation of leukoencephalopathy and atypical mycobacteriosis has been rarely reported. We present a case that is relevant for its unusual presentation and because it may shed further light on the pathogenic mechanisms underlying reversible encephalopathies.Case reportWe report the case of a Hispanic 64-year-old woman with cognitive decline and extensive leukoencephalopathy. Magnetic resonance imaging revealed white-matter lesions with increased water diffusivity, without blood–brain-barrier disruption. Brain biopsy showed tissue rarefaction with vacuolation, mild inflammation, few reactive astrocytes and decreased aquaporin water-channel expression in the lesions. Six months later, she was diagnosed with atypical mycobacterial pulmonary infection. Brain lesions resolved after antimycobacterial treatment.ConclusionWe hypothesize leukoencephalopathic changes and vasogenic edema were associated with decreased aquaporin expression. Further studies should clarify if reversible leukoencephalopathy has a causal relationship with decreased aquaporin expression and atypical mycobacterial infection, and mechanisms underlying leukoencephalopathy resolution after antimycobacterial treatment. This article may contribute to the understanding of pathogenic mechanisms underlying magnetic resonance imaging subcortical lesions and edema, which remain incompletely understood.

OCULAR MELANOMA WITH MULTIPLE GASTROINTESTINAL METASTASES

Malignant melanoma is one of the most common malignancies associated with metastatic disease of the gastrointestinal tract. Gastric metastases are frequently seen in cutaneous melanoma. In ocular malignant melanoma, the most commom site of metastasis was the liver in autopsies series. We report here a case of ocular melanoma with multiple gastrointestinal metastases. A 52-year-old man with a history of choroid ocular melanoma and liver metastasis was submitted for surgical resection of primary neoplasia in 2007. Two years later the patient related intense epigastric pain associated with recent weight loss. Upper digestive endoscopy was carried out and multiple black polypoid sessile lesions, varying from 3 to 15 mm in the proximal stomach and subtle black flat lesions in the gastric antrum and duodenum were found. Biopsy specimens demonstrated metastatic malignant melanoma (Fig. 1). Colonoscopy revealed a 5-mm, subpediculated hardened and yellowish polyp in the sigmoid colon (Fig. 2). Polypectomy was carried out and revealed intestinal mucosa infiltrated by malignant undifferentiated neoplasia (signet ring cells). Immunohistochemical analysis was positive for S100, melanin-A and melanosoma specific antigen (HMB-45 clone), confirming metastatic melanoma. This is a rare case of an ocular melanoma that evolved to metastasis in the gastrointestinal tract. The patient started palliative chemotherapy, but died 5 months later.

Ação da pentoxifilina nos dendrócitos dérmicos FXIIIa de placas de psoríase

FUNDAMENTOS: Nao ha consenso sobre o papel dos dendrocitos dermicos (DD) nos eventos fisiopatologicos nos periodos de exacerbacao e de acalmia da doenca. A pentoxifilina (PTX) e uma metilxantina que inibe varios mecanismos inflamatorios. OBJETIVO: Estudar os efeitos da PTX sobre os dendroticos dermicos de placas de psoriase com tecnicas imuno-histoquimicas. MATERIAL E METODOS: Trinta biopsias de placas de psoriase antes e apos oito semanas de uso oral diario de 1.200mg de PTX foram incubadas com anticorpo primario de coelho antiFator XIIIa e anticorpo de ligacao conjugado com fosfatase alcalina. RESULTADOS: As celulas imunomarcadas Fator XIIIa+ foram proeminentes com morfologia dendritica arborescente na derme papilar formando linha celular logo abaixo da epiderme e exibindo arranjo nodular ao redor dos vasos. Apos tratamento, as celulas apresentaram-se com morfologia dendritica e fusiforme, distribuidas ao redor dos vasos da derme papilar e predominantemente fusiformes dispostas paralelamente a juncao dermoepidermica retificada. CONCLUSOES: A PTX promove aumento do fluxo sanguineo e diminuicao da adesividade endotelial, com aumento dos mastocitos e DD FXIIIa. A PTX inibe o TNF-alfa, que implica a diminuicao da expressao de receptores pelos DDs, como CCR7 e a manutencao do estimulo tecidual para sinalizacao e migracao dos precursores, uma vez que os processos etiopatogeneticos nao sao afetados pela droga.