Minimax Manifold Estimation

We find the minimax rate of convergence in Hausdorff distance for estimating a manifold M of dimension d embedded in R-D given a noisy sample from the manifold. Under certain conditions, we show that the optimal rate of convergence is n(-2/(2+d)). Thus, the minimax rate depends only on the dimension of the manifold, not on the dimension of the space in which M is embedded

COMPUTER-CONTROLLED GAS CHROMATOGRAPH CAPABLE OF ''REAL-TIME'' READOUT OF HIGH-PRECISION DATA.

A gas chromatograph has been assembled which provides computer control of sample injection, column temperature, and flow rate, plus direct computer readout of inlet pressure, mass flow rate, and detector response. Data processing yields, in real-time, a standard deviation of less than 0.05% in retention time, which is comparable to previous results obtained using an off-line computer. However, corrected retention volumes determined in real-time had a standard deviation of about 0.4% which reflected primarily the uncertainty in flow measurement

Design and in vitro study of a dual drug-loaded delivery system produced by electrospinning for the treatment of acute injuries of the central nervous system

Vascular and traumatic injuries of the central nervous system are recognized as global health priorities. A polypharmacology approach that is able to simultaneously target several injury factors by the combination of agents having synergistic effects appears to be promising. Herein, we designed a polymeric delivery system loaded with two drugs, ibuprofen (Ibu) and thyroid hormone triiodothyronine (T3) to in vitro release the suitable amount of the anti-inflammation and the remyelination drug. As a production method, electrospinning technology was used. First, Ibuloaded micro (diameter circa 0.95–1.20 µm) and nano (diameter circa 0.70 µm) fibers were produced using poly(L-lactide) PLLA and PLGA with different lactide/glycolide ratios (50:50, 75:25, and 85:15) to select the most suitable polymer and fiber diameter. Based on the in vitro release results and in-house knowledge, PLLA nanofibers (mean diameter = 580 ± 120 nm) loaded with both Ibu and T3 were then successfully produced by a co-axial electrospinning technique. The in vitro release studies demonstrated that the final Ibu/T3 PLLA system extended the release of both drugs for 14 days, providing the target sustained release. Finally, studies in cell cultures (RAW macrophages and neural stem cell-derived oligodendrocyte precursor cells—OPCs) demonstrated the anti-inflammatory and promyelinating efficacy of the dual drug-loaded delivery platform

Exosomes released by EBV-infected nasopharyngeal carcinoma cells convey the viral Latent Membrane Protein 1 and the immunomodulatory protein galectin 9

BACKGROUND: Nasopharyngeal carcinomas (NPC) are consistently associated with the Epstein-Barr virus (EBV). Their malignant epithelial cells contain the viral genome and express several antigenic viral proteins. However, the mechanisms of immune escape in NPCs are still poorly understood. EBV-transformed B-cells have been reported to release exosomes carrying the EBV-encoded latent membrane protein 1 (LMP1) which has T-cell inhibitory activity. Although this report suggested that NPC cells could also produce exosomes carrying immunosuppressive proteins, this hypothesis has remained so far untested. METHODS: Malignant epithelial cells derived from NPC xenografts – LMP1-positive (C15) or negative (C17) – were used to prepare conditioned culture medium. Various microparticles and vesicles released in the culture medium were collected and fractionated by differential centrifugation. Exosomes collected in the last centrifugation step were further purified by immunomagnetic capture on beads carrying antibody directed to HLA class II molecules. Purified exosomes were visualized by electron microscopy and analysed by western blotting. The T-cell inhibitory activities of recombinant LMP1 and galectin 9 were assessed on peripheral blood mononuclear cells activated by CD3/CD28 cross-linking. RESULTS: HLA-class II-positive exosomes purified from C15 and C17 cell supernatants were containing either LMP1 and galectin 9 (C15) or galectin 9 only (C17). Recombinant LMP1 induced a strong inhibition of T-cell proliferation (IC50 = 0.17 nM). In contrast recombinant galectin 9 had a weaker inhibitory effect (IC50 = 46 nM) with no synergy with LMP1. CONCLUSION: This study provides the proof of concept that NPC cells can release HLA class-II positive exosomes containing galectin 9 and/or LMP1. It confirms that the LMP1 molecule has intrinsic T-cell inhibitory activity. These findings will encourage investigations of tumor exosomes in the blood of NPC patients and assessment of their effects on various types of target cells

COVID-19 in breast cancer patients: a subanalysis of the OnCovid registry

BACKGROUND: Cancer patients are at higher risk of COVID-19 complications and mortality than the rest of the population. Breast cancer patients seem to have better prognosis when infected by SARS-CoV-2 than other cancer patients. METHODS: We report a subanalysis of the OnCovid study providing more detailed information in the breast cancer population. RESULTS: We included 495 breast cancer patients with a SARS-CoV-2 infection. Mean age was 62.6 years; 31.5% presented more than one comorbidity. The most frequent breast cancer subtype was luminal-like (n = 245, 49.5%) and 177 (35.8%) had metastatic disease. A total of 332 (67.1%) patients were receiving active treatment, with radical intent in 232 (47.6%) of them. Hospitalization rate was 58.2% and all-cause mortality rate was 20.3%. One hundred twenty-nine (26.1%) patients developed one COVID-19 complication, being acute respiratory failure the most common (n = 74, 15.0%). In the multivariable analysis, age older than 70 years, presence of COVID-19 complications, and metastatic disease were factors correlated with worse outcomes, while ongoing anticancer therapy at time of COVID-19 diagnosis appeared to be a protective factor. No particular oncological treatment was related to higher risk of complications. In the context of SARS-CoV-2 infection, 73 (18.3%) patients had some kind of modification on their oncologic treatment. At the first oncological reassessment (median time: 46.9 days ± 36.7), 255 (51.6%) patients reported to be fully recovered from the infection. There were 39 patients (7.9%) with long-term SARS-CoV-2-related complications. CONCLUSION: In the context of COVID-19, our data confirm that breast cancer patients appear to have lower complications and mortality rate than expected in other cancer populations. Most breast cancer patients can be safely treated for their neoplasm during SARS-CoV-2 pandemic. Oncological treatment has no impact on the risk of SARS-CoV-2 complications, and, especially in the curative setting, the treatment should be modified as little as possible

Mechanism of Dinitrochlorobenzene-Induced Dermatitis in Mice: Role of Specific Antibodies in Pathogenesis

Dinitrochlorobenzene-induced contact hypersensitivity is widely considered as a cell-mediated rather than antibody-mediated immune response. At present, very little is known about the role of antigen-specific antibodies and B cells in the development of dinitrochlorobenzene-induced hypersensitivity reactions, and this is the subject of the present investigation.Data obtained from multiple lines of experiments unequivocally showed that the formation of dinitrochlorobenzene-specific Abs played an important role in the development of dinitrochlorobenzene-induced contact hypersensitivity. The appearance of dinitrochlorobenzene-induced skin dermatitis matched in timing the appearance of the circulating dinitrochlorobenzene-specific antibodies. Adoptive transfer of sera containing dinitrochlorobenzene-specific antibodies from dinitrochlorobenzene-treated mice elicited a much stronger hypersensitivity reaction than the adoptive transfer of lymphocytes from the same donors. Moreover, dinitrochlorobenzene-induced contact hypersensitivity was strongly suppressed in B cell-deficient mice with no DNCB-specific antibodies. It was also observed that treatment of animals with dinitrochlorobenzene polarized Th cells into Th2 differentiation by increasing the production of Th2 cytokines while decreasing the production of Th1 cytokines.In striking contrast to the long-held belief that dinitrochlorobenzene-induced contact hypersensitivity is a cell-mediated immune response, the results of our present study demonstrated that the production of dinitrochlorobenzene-specific antibodies by activated B cells played an indispensible role in the pathogenesis of dinitrochlorobenzene-induced CHS. These findings may provide new possibilities in the treatment of human contact hypersensitivity conditions

Compound A, a Dissociated Glucocorticoid Receptor Modulator, Inhibits T-bet (Th1) and Induces GATA-3 (Th2) Activity in Immune Cells

Background: Compound A (CpdA) is a dissociating non-steroidal glucocorticoid receptor (GR) ligand which has antiinflammatory properties exerted by down-modulating proinflammatory gene expression. By favouring GR monomer formation, CpdA does not enhance glucocorticoid (GC) response element-driven gene expression, resulting in a reduced side effect profile as compared to GCs. Considering the importance of Th1/Th2 balance in the final outcome of immune and inflammatory responses, we analyzed how selective GR modulation differentially regulates the activity of T-bet and GATA-3, master drivers of Th1 and Th2 differentiation, respectively. Results: Using Western analysis and reporter gene assays, we show in murine T cells that, similar to GCs, CpdA inhibits T-bet activity via a transrepressive mechanism. Different from GCs, CpdA induces GATA-3 activity by p38 MAPK-induction of GATA-3 phosphorylation and nuclear translocation. CpdA effects are reversed by the GR antagonist RU38486, proving the involvement of GR in these actions. ELISA assays demonstrate that modulation of T-bet and GATA-3 impacts on cytokine production shown by a decrease in IFN-c and an increase in IL-5 production, respectively. Conclusions: Taken together, through their effect favoring Th2 over Th1 responses, particular dissociated GR ligands, fo