VEGF(164)-mediated inflammation is required for pathological, but not physiological, ischemia-induced retinal neovascularization

Hypoxia-induced VEGF governs both physiological retinal vascular development and pathological retinal neovascularization. In the current paper, the mechanisms of physiological and pathological neovascularization are compared and contrasted. During pathological neovascularization, both the absolute and relative expression levels for VEGF(164) increased to a greater degree than during physiological neovascularization. Furthermore, extensive leukocyte adhesion was observed at the leading edge of pathological, but not physiological, neovascularization. When a VEGF(164)-specific neutralizing aptamer was administered, it potently suppressed the leukocyte adhesion and pathological neovascularization, whereas it had little or no effect on physiological neovascularization. In parallel experiments, genetically altered VEGF(164)-deficient (VEGF(120/188)) mice exhibited no difference in physiological neovascularization when compared with wild-type (VEGF(+/+)) controls. In contrast, administration of a VEGFk-1/Fc fusion protein, which blocks all VEGF isoforms, led to significant suppression of both pathological and physiological neovascularization. In addition, the targeted inactivation of monocyte lineage cells with clodronate-liposomes led to the suppression of pathological neovascularization. Conversely, the blockade of T lymphocyte-mediated immune responses with an anti-CD2 antibody exacerbated pathological neovascularization. These data highlight important molecular and cellular differences between physiological and pathological retinal neovascularization. During pathological neovascularization, VEGF(164) selectively induces inflammation and cellular immunity. These processes provide positive and negative angiogenic regulation, respectively. Together, new therapeutic approaches for selectively targeting pathological, but not physiological, retinal neovascularization are outlined

Endogenous VEGF Is Required for Visual Function: Evidence for a Survival Role on Müller Cells and Photoreceptors

Vascular endothelial growth factor (VEGF) is well known for its role in normal and pathologic neovascularization. However, a growing body of evidence indicates that VEGF also acts on non-vascular cells, both developmentally as well as in the adult. In light of the widespread use of systemic and intraocular anti-VEGF therapies for the treatment of angiogenesis associated with tumor growth and wet macular degeneration, systematic investigation of the role of VEGF in the adult retina is critical.Using immunohistochemistry and Lac-Z reporter mouse lines, we report that VEGF is produced by various cells in the adult mouse retina and that VEGFR2, the primary signaling receptor, is also widely expressed, with strong expression by Müller cells and photoreceptors. Systemic neutralization of VEGF was accomplished in mice by adenoviral expression of sFlt1. After 14 days of VEGF neutralization, there was no effect on the inner and outer retina vasculature, but a significant increase in apoptosis of cells in the inner and outer nuclear layers. By four weeks, the increase in neural cell death was associated with reduced thickness of the inner and outer nuclear layers and a decline in retinal function as measured by electroretinograms. siRNA-based suppression of VEGF expression in a Müller cell line in vitro supports the existence of an autocrine role for VEGF in Müller cell survival. Similarly, the addition of exogenous VEGF to freshly isolated photoreceptor cells and outer-nuclear-layer explants demonstrated VEGF to be highly neuroprotective.These results indicate an important role for endogenous VEGF in the maintenance and function of adult retina neuronal cells and indicate that anti-VEGF therapies should be administered with caution

Aberrant antigenic expression in extranodal NK/T-cell lymphoma: a multi-parameter study from Thailand

<p>Abstract</p> <p>Background</p> <p>Extranodal NK/T-cell lymphoma, nasal type (ENKTL) is not common worldwide, but it is the most common T- and NK-cell lymphomas in many Asian countries. Immunophenotypic profiles were studied based on limited series. The authors, therefore, studied on ENKTL according to characterize immunophenotypic profiles as well as the distribution of EBV subtype and LMP-1 gene deletion.</p> <p>Methods</p> <p>By using tissue microarray (TMA), immunohistochemical study and EBV encoded RNA (EBER) in situ hybridization were performed. T-cell receptor (TCR) gene rearrangement, EBV subtyping, and LMP-1 gene deletion were studied on the available cases.</p> <p>Results</p> <p>There were 22 cases eligible for TMA. ENKTL were positive for CD3 (91%), CD5 (9%), CD7 (32%), CD4 (14%), CD56 (82%), TIA-1 (100%), granzyme B (95%), perforin (86%), CD45 (83%), CD30 (75%), Oct2 (25%), and IRF4/MUM1 (33%). None of them was positive for βF1, CD8, or CD57. TCR gene rearrangement was negative in all 18 tested cases. EBV was subtype A in all 15 tested cases, with 87% deleted LMP-1 gene. Cases lacking perforin expression demonstrated a significantly poorer survival outcome (p = 0.008).</p> <p>Conclusions</p> <p>The present study demonstrated TIA-1 and EBER as the two most sensitive markers. There were a few CD3 and/or CD56 negative cases noted. Interestingly, losses of CD45 and/or CD7 were not uncommon while Oct2 and IRF4/MUM1 could be positive in a subset of cases. Based on the present study in conjunction with the literature review, determination of PCR-based TCR gene rearrangement analysis might not be a useful technique for making diagnosis of ENKTL.</p

The spin label amino acid TOAC and its uses in studies of peptides: chemical, physicochemical, spectroscopic, and conformational aspects

We review work on the paramagnetic amino acid 2,2,6,6-tetramethyl-N-oxyl-4-amino-4-carboxylic acid, TOAC, and its applications in studies of peptides and peptide synthesis. TOAC was the first spin label probe incorporated in peptides by means of a peptide bond. In view of the rigid character of this cyclic molecule and its attachment to the peptide backbone via a peptide bond, TOAC incorporation has been very useful to analyze backbone dynamics and peptide secondary structure. Many of these studies were performed making use of EPR spectroscopy, but other physical techniques, such as X-ray crystallography, CD, fluorescence, NMR, and FT-IR, have been employed. The use of double-labeled synthetic peptides has allowed the investigation of their secondary structure. A large number of studies have focused on the interaction of peptides, both synthetic and biologically active, with membranes. In the latter case, work has been reported on ligands and fragments of GPCR, host defense peptides, phospholamban, and β-amyloid. EPR studies of macroscopically aligned samples have provided information on the orientation of peptides in membranes. More recent studies have focused on peptide–protein and peptide–nucleic acid interactions. Moreover, TOAC has been shown to be a valuable probe for paramagnetic relaxation enhancement NMR studies of the interaction of labeled peptides with proteins. The growth of the number of TOAC-related publications suggests that this unnatural amino acid will find increasing applications in the future

Pediatric gastrointestinal PEComas: a diagnostic challenge.

Perivascular epithelioid cell tumors (PEComas) in the pediatric population are very rare and frequently arise in the gastrointestinal tract. These tumors are characterized by variable morphological and immunohistochemical features, which may pose significant problems in differential diagnosis with other gastrointestinal mesenchymal tumors in pediatric patients. In presenting an unusual pediatric case of gastrointestinal PEComa, we also discuss the possible differential diagnosis of this rare entit

LEIOMYOMATOSIS WITH VASCULAR INVASION - A UNIFIED PATHOGENESIS REGARDING LEIOMYOMA WITH VASCULAR MICROINVASION, BENIGN METASTASIZING LEIOMYOMA AND INTRAVENOUS LEIOMYOMATOSIS

6Three uterine leiomyomas with vascular invasion (LWVI), two of which were associated with pulmonary leiomyomatous nodules, and a case of intravenous leiomyomatosis (IVL) invading the vena cava and extending to the right atrium, are described. Despite their histological benignity, these lesions have a strong tendency to metastasize and are closely related to the so-called benign metastasizing leiomyoma (BML). From a clinical point of view, the pulmonary nodules of LWVI are stable or slowIy-growing. The IVL was a ''worm-like'' tumour that presented as a cardiac mass. On the basis of their histological and immunohistological features, a unified histogenetic view of LWVI, IVL and BML of the uterus is proposed. LWVI and BML may be the same pathological entity and microscopic vascular invasion may represent the metastatic mechanism of BML. Alternatively, LWVI may be the initial stage of TVL. In rare instances, IVL may be associated with distant parenchymal (pulmonary) metastases. LWVI seems to be the precursor of both BML and IVL.nonenoneCanzonieri, V; Damore, Esg; Bartoloni, G; Piazza, M; Blandamura, S; Carbone,

Omental mesenteric myxoid hamartoma, a subtype of inflammatory myofibroblastic tumor? Considerations based on the histopathological evaluation of four cases

Omental mesenteric myxoid hamartoma (OMH) is a distinctive myxoid lesion of infancy, characterized by a benign clinical behavior. In the current World Health Organization (WHO) classification of soft tissue tumors, it is considered as part of the morphologic spectrum of inflammatory myofibroblastic tumors (IMT), but this relationship with IMT is still subject to debate. Four lesions with histologic features of OMH occurring in newborns and toddlers are described and compared with classic, ALK-positive IMT. All OMH showed a peculiar dot-like immunostaining for ALK, which, in one of the cases, was cytogenetically found to be associated with an inversion of the ALK gene. While OMHs were positive for smooth muscle actin (SMA), desmin, WT1, podoplanin, and cytokeratins (CAM5.2 and AE1-3), IMT were consistently positive only for SMA (10 cases). ALK-1 displayed cytoplasmic staining in IMT and characteristic paranuclear dot-like staining in OMH. © 2015, Springer-Verlag Berlin Heidelberg

Combination of rituximab, bendamustine, and cytarabine for patients with mantle-cell non-Hodgkin lymphoma ineligible for intensive regimens or autologous transplantation.

PURPOSE: The combination of bendamustine (B) and rituximab (R) is efficacious, with favorable toxicity in mantle-cell lymphoma (MCL). In this phase II study, we combined cytarabine with R and B (R-BAC) in patients with MCL age ≥ 65 years who were previously untreated or relapsed or refractory (R/R) after one prior immunochemotherapy treatment. PATIENTS AND METHODS: In stage one, we established the maximum-tolerated dose (MTD) of cytarabine in R-BAC. In stage two, patients received R (375 mg/m(2) intravenously [IV] on day 1), B (70 mg/m(2) IV on days 2 and 3), and cytarabine (MTD IV on days 2 to 4) every 28 days for four to six cycles. The primary end point (overall response rate [ORR]) was evaluated by positron emission tomography. Secondary end points included safety, progression-free survival (PFS), response duration, and overall survival. RESULTS: Forty patients (median age, 70 years; 20 previously untreated patients) were enrolled; 93% had Ann Arbor stage III/IV disease; 49% had high Mantle Cell International Prognostic Index scores, with 15% blastoid histology. All R/R patients (35% refractory) had previously received R-containing regimens. The cytarabine MTD used in stage two was 800 mg/m(2), and R-BAC was well tolerated, with an 85% treatment completion rate. The major toxicity was transient grades 3 to 4 thrombocytopenia (87% of patients); febrile neutropenia occurred in 12%. The ORR was 100% (95% complete response [CR]) for previously untreated and 80% (70% CR) for R/R patients. The 2-year PFS rate (± standard deviation) was 95% ± 5% for untreated and 70% ± 10% for R/R patients. CONCLUSION: R-BAC is well tolerated and active against MCL

Prevalence and clinical implications of bone marrow involvement in pediatric anaplastic large cell lymphoma

Anaplastic large cell lymphoma (ALCL) harbors the reciprocal chromosomal translocation t(2;5)(p23;q35) in approximately 80% of the cases. The genes involved are nucleophosmin (NPM) and anaplastic lymphoma kinase (ALK) and the resulting chimeric NPM\u2013ALK protein is thought to play a key role in the pathogenesis of t(2;5) positive ALCL. Few data on bone marrow (BM) involvement in ALCL have been published and they mostly rely on morphological examination of BM smears. We studied 52 ALCL for NPM\u2013ALK expression by RT-PCR: 47/52 biopsies were positive. In 41 of the 47 cases we obtained the BM at diagnosis and investigated the prevalence of minimal BM infiltration by RT-PCR and real-time PCR. Minimal disseminated disease was positive in 25/41 patients (61%), of whom six had morphologically infiltrated BM. Survival analysis demonstrated a 5-year progression-free survival of 41plusminus11% for patients with molecularly positive BM vs 100% for patients with negative BM (P= 0.001). These results suggest that minimal BM involvement at diagnosis is a common event in pediatric ALCL and that minimal BM disease monitoring could identify patients at risk of relapse