gamma-Interferon increases metaiodobenzylguanidine incorporation and retention in human neuroblastoma cells.

Iodine-labeled m-iodobenzylguanidine (MIBG) is a widely used radiopharmaceutical for both diagnosis and biologically targeted radiotherapy of neuroblastoma. However, resistance to the radiotherapeutic effects of MIBG is often encountered, mainly due to lack of MIBG accumulation by neoplastic cells. We have investigated whether the induction of neuroblastoma cell differentiation modifies MIBG incorporation and retention. LAN-5 cells were selected, due to their moderate ability to take up MIBG. Treatment of these cells with gamma-interferon (IFN-gamma) resulted in morphological changes accompanied by a significant increase in overall cell-associated MIBG. Desimipramine, but not reserpine, easily depleted IFN-gamma-treated LAN-5 cells of their MIBG content. This suggests that the mechanism involved is an uptake enhancement rather than an improved storage ability. Indeed, IFN-gamma induces de nov synthesis of MIBG receptor-transporters, as demonstrated by polymerase chain reaction amplification and semiquantitative analysis. Our results suggest that pretreating neuroblastoma patients with IFN-gamma before MIBG administration may enhance the efficacy of both biologically targeted radioimaging and therapy of this tumor.     

Lack of CD 29 (beta1 integrin) and CD 54 (ICAM-1) adhesion molecules in intravascular lymphomatosis

Intravascular Lymphomatosis (IL) is a rare and usually aggressive form of non-Hodgkin's lymphoma characterized by the growth of neoplastic cells within vascular lumina that usually presents with skin or central nervous system (CNS) involvement. The mechanism(s) for the selective intravascular growth of this neoplasm remain(s) unexplained. We now report clinical and immunohistologic data on surgical material from 6 cases of IL; in 4 of 6 cases, autopsies were performed. Our IL cases shared the following features: (1) B-cell lineage; (2) lack of skin involvement at presentation; (3) aggressive behavior; and (4) lack of extravascular lymphomatous masses; in addition, 1 case had an associated gastric low-grade MALT lymphoma. We studied by immunohistochemistry formalin-fixed, paraffin-embedded sections with monoclonal antibodies to molecules known to be involved in lymphocyte and endothelial adhesion phenomena, that is, CD29 (beta1 integrin subunit), CD43 (leukosialin), CD44 (H-CAM), CD54 (ICAM-1), embryonal N-CAM (e-NCAM), and EMA (episialin). In all cases, the surfaces of IL aggregates reacted for CD44 but were consistently negative for CD29; also absent was CD54. Conversely, the integrity of the endothelial cells was underscored by their even reactivity for CD29, CD44, and CD54. Given that CD29 is currently regarded as critical for lymphocyte trafficking in general and for transvascular migration in particular, and CD54 is also involved in transvascular lymphocyte migration, we conclude that their consistent absence in IL may contribute to its intravascular and disseminated distribution pattern. The rather frequent association of IL with various conventional lymphomas is known; yet, one of our cases appears to be the first report of IL associated with a low-grade MALT lymphoma.     

Intracellular lectin-binding sites in symbiont-bearingCrithidia species

Crithidia oncopelti, C. deanei, andC. desouzai are flagellates of the Trypanosomatidae family that present bacterium-like endosymbionts in their cytoplasm. Direct and indirect lectin-gold labeling techniques were used at the electron microscopic level in Lowicryl K4M-embedded cells to demonstrate the presence of intracellular lectin-binding sites. We used the lectinsUlex europaeus I, Griffonia simplicifolia II, Ricinus communis I, Arachis hypogaea, G. simplicifolia I, Wistaria floribunda, Limulus polyphemus, andCanavalia ensiformis, which recognize -l-fucose, - and -N-acetylglucosamine, -galactose and -N-acetylgalactosamine, -galactose, -galactose, -N-acetylgalactosamine, sialic acid and -d-mannose, and -d-glucose residues, respectively. The nucleus was the cellular structure most frequently labeled by the lectins. The Golgi complex was seldom labeled, whereas the endoplasmic reticulum and the flagellar pocket presented a large number of binding sites. Symbionts had their two unit membranes weakly labeled by the different lectins but displayed no labeling of the space between the membranes.     

Patterns of exochorion ornaments on eggs of seven South American species of Lutzomyia sand flies (Diptera: Psychodidae)

The patterns of exochorion ornaments on eggs of seven South American Lutzomyia sand fly species were analyzed by scanning electron microscopy (SEM): Lutzomyia (Lutzomyia) cruzi (Mangabeira 1938), Lutzomyia (Micropygomyia) evandroi (Costa Lima and Antunes 1936), L. (Nyssomyia) intermedia (Lutz and Neiva 1912), L. longipalpis (Lutz and Neiva 1912), L. migonei (Franca 1920), L. (Nyssomyia) neivai (Pinto 1926), and L. renei (Martins, Falcao, and Silva 1957). Different patterns were observed, which showed the distinction between some species. Egg ornaments in L. cruzi and L. longipalpis appear as single, parallel, unconnected ridges, whereas eggs of L. migonei appear as single, parallel, connected ridges. Eggs of L. (Nyssomyia) intermedia and L. (N.) neivai present a new variation of the single, unconnected, parallel ridges pattern: small tubercles are present, distributed between the ridges. Eggs of L. renei present an elliptical pattern, with most structures connected by straight ridges. Eggs of L. (M.) evandroi present a polygonal pattern, with alternate rows of small and large hexagons. Our data emphasize the advantages of the SEM approach in the study of the exochorion patterns of Lutzomyia eggs and in the distinction of the sand fly species.     

Phase I trial and pharmacokinetics of fenretinide in children with neuroblastoma.

PURPOSE: Fenretinide (4HPR), a synthetic retinoid, induces apoptosis in neuroblastoma cells. A Phase I study in children with neuroblastoma was designed to determine maximum tolerated dose, toxicity, and pharmacokinetics. EXPERIMENTAL DESIGN: Fifty-four patients received oral 4HPR, once daily, for 28 days, followed by a 7-day interruption, for up to 6 courses. The starting dose was 100 mg/m(2)/day. At least 3 patients were entered at each escalating 4HPR dose level. Pharmacokinetic sampling was performed on days 1 and 28 of the first course. RESULTS: Fifty-four patients, of whom 53 were evaluable, received doses between 100 and 4000 mg/m(2)/day for a total of 168 courses. Additional dose escalation was precluded by capsule number intake. A total of 34 of 53 evaluable patients showed manageable, reversible toxicities, which were not dose related. One dose-limiting toxicity (nyctalopia grade 3) occurred after the 1000 mg/m(2)/day dose. Twelve patients showed grade 2 toxicity: skin xerosis (6 cases); nyctalopia (3 cases); hepatic toxicity (1 case); diarrhea (1 case); and headache (1 case). Stable disease was observed in 41 patients for a median period of 23 months (range 2-35+). After first administration, average 4HPR peak plasma levels ranged from 0.6 to 6 micro M (after 100 and 4000 mg/m(2)/day, respectively) and increased 2-fold (to 1.3 and 12.9 micro M, respectively) after the 28-day treatment. 4HPR half-life increased from 17 h after the first administration to 25 h after the 28(th) administration. Incidence of grade 2-3 toxicity was 0 of 12 (0%), 7 of 22 (31%), and 4 of 8 (50%) with peak 4HPR concentrations <3 micro M, 3-10 micro M, and >10 micro M, respectively. After repeated treatment, retinol levels decreased from 20 to 10% of pretreatment levels after all of the doses. CONCLUSIONS: In children, 4HPR administration up to 4000 mg/m(2)/day over 28 days, followed by a 7-day interruption, results in manageable toxicity and in drug plasma concentrations comparable with those that induce apoptosis in neuroblastoma cell lines.     

Targeted liposomal c-myc antisense oligodeoxynucleotides induce apoptosis and inhibit tumor growth and metastases in human melanoma models.

PURPOSE: Melanoma is a highly malignant and increasingly common tumor. Because the cure rate of metastatic melanoma by conventional treatment is very low, new therapeutic approaches are needed. We previously reported that coated cationic liposomes (CCL) targeted with a monoclonal antibody against the disialoganglioside (GD(2)) and containing c-myb antisense oligodeoxynucleotides (asODNs) resulted in a selective inhibition of the proliferation of GD(2)-positive neuroblastoma cells in vitro. EXPERIMENTAL DESIGN: Here, we tested the in vivo antitumor effects of this novel antisense liposomal formulation by targeting the c-myc oncogene on melanoma, a neuroectodermal tumor sharing with neuroblastoma the expression of GD(2). RESULTS: Our methods produced GD(2)-targeted liposomes that stably entrapped 90% of added c-myc asODNs. These liposomes showed a selective binding for GD(2)-positive melanoma cells in vitro. Melanoma cell proliferation was inhibited to a greater extent by GD(2)-targeted liposomes containing c-myc asODNs (aGD(2)-CCL-myc-as) than by nontargeted liposomes or free asODNs. The pharmacokinetic results obtained after i.v. injection of [(3)H]-myc-asODNs, free or encapsulated in nontargeted CCLs or GD(2)-targeted CCLs, showed that free c-myc-asODNs were rapidly cleared, with less than 10% of the injected dose remaining in blood at 30 min after injection. c-myc-asODNs encapsulated within either CCL or aGD(2)-CCL demonstrated a more favorable profile in blood, with about 20% of the injected dose of each preparation remaining in vivo at 24 h after injection. In an in vivo melanoma experimental metastatic model, aGD(2)-CCL-myc-as, at a total dose of only 10 mg of asODN per kilogram, significantly inhibited the development of microscopic metastases in the lung compared with animals treated with myc-asODNs, free or entrapped in nontargeted liposomes, or aGD(2)-CCL encapsulating scrambled asODNs (P < 0.01). Moreover, mice bearing established s.c. human melanoma xenografts treated with aGD(2)-CCL-myc-as exhibited significantly reduced tumor growth and increased survival (P < 0.01 versus control mice). The mechanism for the antitumor effects appears to be down-regulation of the expression of the c-myc protein and interruption of c-myc-mediated signaling: induction of p53 and inhibition of Bcl-2 proteins, leading to extensive tumor cell apoptosis. CONCLUSION: These results suggest that inhibition of c-myc proto-oncogene by GD(2)-targeted antisense therapy could provide an effective approach for the treatment of melanoma in an adjuvant setting.     

Scaffolds for cartilage repair of the ankle joint: The impact on surgical practice

BackgroundIdeal management of osteochondral lesions in the ankle joint is still theme of debate. Scaffold-based repair is emerging as a new approach for regenerative treatment.MethodsArticles published in PubMed from 2000 to January 2012 addressing cartilage scaffold-based treatment were identified, including levels I–IV evidence clinical trials with measures of functional, clinical or imaging outcome.ResultsThe analysis showed a progressively increasing number of articles from 2000. The number of selected papers was 19:15 focusing on two-step and 4 on one-step procedures; no randomized studies, 3 comparative studies, 11 case series and 5 case reports were identified.ConclusionsRegenerative surgical approach with scaffold-based procedures is emerging as a potential therapeutic option for the treatment of chondral lesions of the ankle. One step treatments simplify the procedure and the results reported are very close to the previous techniques. However, well-designed studies are lacking, and randomized long-term trials are necessary to confirm the potential of these techniques.Level of evidenceReview – IV.     

Nitrogen‐containing bisphosphonate therapy: assessment of the alveolar bone structure in rats – a blind randomized controlled trial

This study aimed to assess the effect of zoledronic acid exposure on structures of the alveolar bone of rats. The sample was composed of 42 male Wistar rats. Animals in the T1 and T2 groups received weekly doses of 0.2 mg/kg intraperitoneal zoledronic acid for 3 weeks, while animals in the T3 group received the same treatment for 8 weeks. The control groups C1, C2 and C3 received equivalent doses of saline. The first upper molars of Wistar rats in the C2, T2, C3 and T3 groups were extracted. Cone‐beam computerized tomography scans were performed, and the image density was analysed by grey levels. The presence and type of inflammatory infiltrate, vascularization and bone necrosis were assigned by histological qualitative scores. Histomorphometric analysis of bone density was performed in the groups without extraction. No significant differences were found in the bone grey density estimated by grey‐level value and histomorphometric analysis between the C1 and T1 groups (P > 0.05). The grey levels in the T3 group were lower (P < 0.05) than in the C3 group, corresponding to the bone defect. Histological assessments showed the presence of bone necrosis in the T3 group and lower levels of bone remodelling in the test groups (T2 and T3) compared to the control groups (C2 and C3). The results of qualitative analyses did not differ significantly between the groups (P > 0.05). Zoledronic acid‐exposed animals showed maxillary changes including reduced grey levels, the presence of bone necrosis and a higher prevalence of inflammatory signs.