Influence of the incorporation of marine spongin into a Biosilicate®: an in vitro study.

The combination of different biomaterials can be a promising intervention for the composites manufacture, mainly by adding functional and structural characteristics of each material and guarantee the advantages of the use of these composites. In this context, the aim of this study was to develop and evaluated the influence of the incorporation of marine spongin (SPG) into Biosilicate® (BS) in different proportions be used during bone repair. For this purpose, it was to develop and investigate different BS/SPG formulations for physico-chemical and morphological characteristics by pH, loss mass, Fourier transform infrared spectrometer (FTIR) and scanning electron microscope (SEM) analysis. Additionally, the influence of these composites on cell viability, proliferation, and alkaline phosphatase (ALP) activity were investigated. The results revealed that the pH values of all BS groups (with or without SPG) increased over time. A significant mass loss was observed in all composites, mainly with higher SPG percentages. Additionaly, SEM micrographies demonstrated fibers of SPG into BS and material degradation over time. Moreover, FTIR spectral analysis revealed characteristic peaks of PMMA, BS, and SPG in BS/SPG composites. BS/SPG groups demonstrated a positive effect for fibroblast proliferation after 3 and 7 days of culture. Additionally, BS and BS/SPG formulations (at 10% and 20% of SPG) presented similar values of osteoblasts viability and proliferation after 7 days of culture. Furthermore, ALP activity demonstrated no significant difference between BS and BS/SPG scaffolds, at any composition. Based on the present in vitro results, it can be concluded that the incorporation of SPG into BS was possible and produced an improvement in the physical-chemical characteristics and in the biological performance of the graft especially the formulation with 80/20 and 90/10. Future research should focus on in vivo evaluations of this novel composite.

Lactobacillus delbrueckii ssp. bulgaricus OLL1073R-1 feeding enhances humoral immune responses, which are suppressed by the antiviral neuraminidase inhibitor oseltamivir in influenza A virus-infected mice.

Antiviral neuraminidase inhibitors, such as oseltamivir, zanamivir, and peramivir, are widely used for treatment of influenza virus infection. We reported previously that oseltamivir inhibits the viral growth cycle, ameliorates symptoms, and reduces viral antigen quantities. Suppressed viral antigen production, however, induces a reduction of acquired antiviral humoral immunity, and increases the incidence of re-infection rate in the following year. To achieve effective treatment of influenza virus infection, it is necessary to overcome these adverse effects of antiviral neuraminidase inhibitors. Feeding of yogurt fermented with Lactobacillus delbrueckii ssp. bulgaricus (L. bulgaricus) OLL1073R-1 is reported to have immune-stimulatory effects on influenza virus infection in mice and humans. In the present study, we assessed the effect of feeding L. bulgaricus OLL1073R-1 yogurt cultures (YC) on local and systemic humoral immune responses, which were suppressed by oseltamivir treatment, in mice infected with influenza A virus. Yogurt culture (1.14 × 108 cfu/0.4 mL per mouse per day) or sterile water (vehicle) was administered by intragastric gavage for 35 d. At d 22, influenza A virus/Puerto Rico/8/34 (H1N1) (PR8; 0.5 pfu/15 µL per mouse) was instilled intranasally, followed immediately by oral administration of oseltamivir (50 µg/100 µL per mouse, twice daily) or 5% methylcellulose (100 µL/mouse) as a vehicle for 13 d. Titers of anti-PR8-specific IgG and IgA in serum and mucosal secretory IgA (S-IgA) and IgG in bronchoalveolar lavage fluid (BALF) were analyzed by ELISA at 14 d after infection. Oseltamivir significantly suppressed the induction of anti-PR8-specific IgG and IgA in serum and S-IgA and IgG in BALF after infection. Feeding YC mildly but significantly stimulated production of PR8-specific IgA in serum, S-IgA in BALF, and IgG in serum without changing the IgG2a:IgG1 ratio. We analyzed the neutralizing activities against PR8 in serum and BALF and found that oseltamivir also reduced protective immunity, and YC feeding abrogated this effect. The immune-stimulatory tendency of YC on anti-PR8-specific IgA and IgG titers in serum and BALF was also detected in mice re-infected with PR8, but the effect was insignificant, unlike the effect of YC in the initial infection.

Correction to: IL-1b is a key cytokine that induces trypsin upregulation in the influenza virus-cytokine-trypsin cycle.

The original article can be found online.

IL-1ß is a key cytokine that induces trypsin upregulation in the influenza virus-cytokine-trypsin cycle.

Severe influenza is characterized by a cytokine storm, and the influenza virus-cytokine-trypsin cycle is one of the important mechanisms of viral multiplication and multiple organ failure. The aim of this study was to define the key cytokine(s) responsible for trypsin upregulation. Mice were infected with influenza virus strain A/Puerto Rico/8/34 (H1N1) or treated individually or with a combination of interleukin-1ß, interleukin-6, and tumor necrosis factor α. The levels of these cytokines and trypsin in the lungs were monitored. The neutralizing effects of anti-IL-1ß antibodies on cytokine and trypsin expression in human A549 cells and lung inflammation in the infected mice were examined. Infection induced interleukin-1ß, interleukin-6, tumor necrosis factor α, and ectopic trypsin in mouse lungs in a dose- and time-dependent manner. Intraperitoneal administration of interleukin-1ß combined with other cytokines tended to upregulate trypsin and cytokine expression in the lungs, but the combination without interleukin-1ß did not induce trypsin. In contrast, incubation of A549 cells with interleukin-1ß alone induced both cytokines and trypsin, and anti-interleukin-1ß antibody treatment abrogated these effects. Administration of the antibody in the infected mice reduced lung inflammation area. These findings suggest that IL-1ß plays a key role in trypsin upregulation and has a pathological role in multiple organ failure.

Cricoid pressure impedes tracheal intubation with the Pentax-AWS Airwayscope®: a prospective randomized trial.

BACKGROUND: It is unclear how cricoid pressure affects tracheal intubation with the Pentax-AWS Airwayscope(®) (AWS). We conducted a prospective randomized clinical trial in anaesthetized patients. METHODS: Sixty patients were allocated to either the cricoid pressure (CP) group (n=30) or the sham group (n=30). We compared the two groups with regard to intubation time, number of attempts required for insertion of the Intlock blade (disposable blade of the AWS) and tracheal intubation, percentage of glottic opening (POGO) score, and subjective difficulty of both laryngoscopy and passage of a tube through the glottis. RESULTS: Intubation time was significantly longer in the CP group (median 45[IQR40-59] s) than in the sham group (32[28-45] s) (P=0.003, 95% CI for median difference 5-24 s). The number required for insertion of the Intlock blade did not differ between the groups (P=0.08), but the number for tracheal intubation was significantly higher in the CP group (1 attempt in 14 patients, 2 in 7, 3 in 9) than in the sham group (1 attempt in 24 patients, 2 in 6; P=0.002). POGO score did not differ significantly between the groups (P=0.60), nor did the subjective difficulty of laryngoscopy (P=0.06). The visual analogue scale score for passage of a tube through the glottis was significantly higher in the CP group than in the sham group (P<0.001). CONCLUSIONS: Cricoid pressure impedes tracheal intubation using the AWS, and is associated with longer intubation time, which can be attributed to increased difficulty in the passage of a tube through the glottis. CLINICAL TRIAL REGISTRY NUMBER: UMIN000018209.

Influenza A virus infection of vascular endothelial cells induces GSK-3ß-mediated ß-catenin degradation in adherens junctions, with a resultant increase in membrane permeability.

Multiorgan failure with vascular hyperpermeability is the final outcome in the progression of seasonal influenza virus pneumonia and influenza-associated encephalopathy, and it is also common in infection with highly pathogenic avian influenza virus. However, the precise molecular mechanism by which influenza virus infection causes vascular endothelial cell hyperpermeability remains poorly defined. We investigated the mechanisms of hyperpermeability of human umbilical vein endothelial cells infected with influenza A virus (IAV)/Puerto Rico/8/34 (PR8) (H1N1). The levels of ß-catenin, a key regulatory component of the vascular endothelial-cadherin cell adhesion complex, were markedly decreased during infection for 28 h, with increments of vascular hyperpermeability measured by transendothelial electrical resistance. Lactacystin (at 2 µM), a proteasome inhibitor, inhibited the decrease in ß-catenin levels. Since the N-terminal phosphorylation of ß-catenin by glycogen synthase kinase (GSK)-3ß is the initiation step of proteasome-dependent degradation, we examined the effects of GSK-3ß suppression by RNA interference in endothelial cells. IAV-infection-induced ß-catenin degradation was significantly inhibited in GSK-3ß-knockdown cells, and transfection of cells with recombinant ß-catenin significantly suppressed IAV-induced hyperpermeability. These findings suggest that IAV infection induces GSK-3ß-mediated ß-catenin degradation in the adherens junctional complexes and induces vascular hyperpermeability. The in vitro findings of ß-catenin degradation and activation of GSK-3ß after IAV infection were confirmed in lungs of mice infected with IAV PR8 during the course of infection from day 0 to day 6. These results suggest that GSK-3ß-mediated ß-catenin degradation in adherens junctions is one of the key mechanisms of vascular hyperpermeability in severe influenza.

Effect of a new bioactive fibrous glassy scaffold on bone repair.

Researchers have investigated several therapeutic approaches to treat non-union fractures. Among these, bioactive glasses and glass ceramics have been widely used as grafts. This class of biomaterial has the ability to integrate with living bone. Nevertheless, bioglass and bioactive materials have been used mainly as powder and blocks, compromising the filling of irregular bone defects. Considering this matter, our research group has developed a new bioactive glass composition that can originate malleable fibers, which can offer a more suitable material to be used as bone graft substitutes. Thus, the aim of this study was to assess the morphological structure (via scanning electron microscope) of these fibers upon incubation in phosphate buffered saline (PBS) after 1, 7 and 14 days and, also, evaluate the in vivo tissue response to the new biomaterial using implantation in rat tibial defects. The histopathological, immunohistochemistry and biomechanical analyzes after 15, 30 and 60 days of implantation were performed to investigate the effects of the material on bone repair. The PBS incubation indicated that the fibers of the glassy scaffold degraded over time. The histological analysis revealed a progressive degradation of the material with increasing implantation time and also its substitution by granulation tissue and woven bone. Histomorphometry showed a higher amount of newly formed bone area in the control group (CG) compared to the biomaterial group (BG) 15 days post-surgery. After 30 and 60 days, CG and BG showed a similar amount of newly formed bone. The novel biomaterial enhanced the expression of RUNX-2 and RANK-L, and also improved the mechanical properties of the tibial callus at day 15 after surgery. These results indicated a promising use of the new biomaterial for bone engineering. However, further long-term studies should be carried out to provide additional information concerning the material degradation in the later stages and the bone regeneration induced by the fibrous material.

Bioglass/collagen scaffolds combined with bone marrow stromal cells on bone healing in an experimental model in cranial defects in rats.

This study aimed to develop bone regenerative therapeutic strategies, based on the addition of bone marrow stromal cells (BMSC) on bioglass/collagen (BG/COL) scaffolds. For this purpose, an in vivo study was conducted using tissue response of the BG/COL scaffolds combined with BMSC in a critical-size defects. Wistar rats were submitted to the surgical procedure to perform the cranial critical size bone defects and distributed in four groups (20 animals per group): Control Group (CG) (rats submitted to the cranial bone defect surgery without treatment), Bioglass Group (BG) (rats treated with BG), BG/COL Group (rats treated with BG/COL) and Bioglass/Collagen and BMSC Group (BG/COL/BMSC) (rats treated with BG/COL scaffolds enriched with BMSCs). Animals were euthanized 15 and 30 days after surgery. Scanning electron microscopy, histopathological and immunohistochemistry analysis were used. SEM analysis demonstrated that porous scaffolds were obtained, and Col fibers were successfully impregnated to BG matrices. The implantation of the BMSC on BG/COL based scaffolds was effective in stimulating newly bone formation and produced an increased immunoexpression of markers related to the bone repair. These results highlight the potential of BG/COL scaffolds and BMSCs to be used as a therapeutic approach for bone regeneration.

Salvage of infarcted myocardium by angiogenic action of basic fibroblast growth factor.

Coronary collateral vessels reduce damage to ischemic myocardium after coronary obstruction. Factors that stimulate collateral formation are expected to have ameliorating effects on myocardial infarction. In a canine experimental myocardial infarct model, intracoronary injection of basic fibroblast growth factor (bFGF) improved cardiac systolic function and reduced infarct size. Treatment with bFGF increased the number of arterioles and capillaries in the infarct. Thus, the angiogenic action of bFGF might lead to a reduction in infarct size. The application of bFGF might bring about a therapeutic modality for the salvage of infarcted myocardium.

Characterization and Cytotoxicity Evaluation of a Marine Sponge Biosilica.

Bone fractures characterize an important event in the medical healthcare, being related to traumas, aging, and diseases. In critical conditions, such as extensive bone loss and osteoporosis, the tissue restoration may be compromised and culminate in a non-union consolidation. In this context, the osteogenic properties of biomaterials with a natural origin have gained prominence. Particularly, marine sponges are promising organisms that can be exploited as biomaterials for bone grafts. Thus, the objectives of this study were to study the physicochemical and morphological properties of biosilica (BS) from sponges by using scanning electron microscopy, Fourier-transform infrared, X-ray diffraction (SEM, FTIR and XRD respectively), mineralization, and pH. In addition, tests on an osteoblast precursor cell line (MC3T3-E1) were performed to investigate its cytotoxicity and proliferation in presence of BS. Bioglass (BG) was used as gold standard material for comparison purposes. Sponge BS was obtained, and this fact was proven by SEM, FTIR, and XRD analysis. Calcium assay showed a progressive release of this ion from day 7 and a more balanced pH for BS was maintained compared to BG. Cytotoxicity assay indicated that BS had a positive influence on MC3T3-E1 cells viability and qRT-PCR showed that this material stimulated Runx2 and BMP4 gene expressions. Taken together, the results indicate a potential use of sponge biosilica for tissue engineering applications.

Phase I/II study of irinotecan and UFT for advanced or metastatic colorectal cancer.

UNLABELLED: The aim of this study was to determine the recommended dose of irinotecan in combination with the fixed dose of oral UFT as first-line therapy in patients with advanced or recurrent colorectal cancer, and to evaluate the response rate and overall survival as a phase II study. PATIENTS AND METHODS: Thirteen patients were recruited into a phase I trial. Four doses of irinotecan ranging from 60 to 150 mg/m2/day were administered intravenously on day 1 and day 16 in combination with UFT given orally from day 2 to day 15. In a phase II study, 53 patients received at least one cycle of this therapy. RESULTS: The recommended dose of this combination was determined as irinotecan 120 mg/m2/day and UFT 400 mg/m2/day. Dose-limiting toxicities were neutropenia and prolonged leucopenia. On an intent-to-treat analysis, the response rate in the phase II study was 24.5% (95% confidence interval 13.8% to 38.2%). The median overall survival time was 20.3 months (95% confidence interval, 15.0-22.8 months). Out of 20 patients with stable disease, 17 who received more than 4 cycles of the regimen lived longer than the other 3 patients who received fewer than 3 cycles (p = 0.0353). Hematological adverse events were mainly grade 3/4 neutropenia observed in 6 out of 53 patients. Grade 3 non-hematological toxicities, such as diarrhea, anorexia, nausea/vomiting and alopecia were observed in 6 patients. CONCLUSION: Irinotecan combined with oral UFT was effective and well-tolerated. This regimen may be considered as a first-line therapy for advanced or metastatic colorectal cancer and may result in fairly long survival, even for patients with stable disease.

Characterization and biological evaluation of the introduction of PLGA into biosilicate®.

The aims of this study were to characterize different BS/PLGA composites for their physicochemical and morphological characteristics and evaluate the in vitro and in vivo biological performance. The physicochemical and morphological modifications were analyzed by pH, mass loss, XRD, setting time, and SEM. For in vitro analysis, the osteoblast and fibroblast viability was evaluated. For in vivo evaluations, histopathology and immunohistochemistry were performed in a tibial defect in rats. After incubation, all composites presented lower values in pH and mass loss over time. Moreover, XRD and SEM analysis confirmed that the composites degraded over time. Additionally, pore formation was observed by SEM analysis after incubation mainly in BS/PLGA groups. BS/PLGA showed significantly increased in osteoblast viability 24 h. Moreover, BS/PLGA composites demonstrated an increase in fibroblast viability in all periods analyzed when compared to BS. In the in vivo study, after 2 and 6 weeks of implantation of biomaterials, histopathological findings revealed that the BS/PLGA composites degrades over time, mainly at periphery. Moreover, can be observed the presence of granulation tissue, bone formation, Runx-2, and RANKL immunoexpression in all groups. In conclusion, BS/PLGA composites present appropriate physicochemical characteristics, stimulate the cellular viability, and enhance the bone repair in vivo. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1063-1074, 2017.

Characterization and biocompatibility of a fibrous glassy scaffold.

Bioactive glasses (BGs) are known for their ability to bond to living bone and cartilage. In general, they are readily available in powder and monolithic forms, which are not ideal for the optimal filling of bone defects with irregular shapes. In this context, the development of BG-based scaffolds containing flexible fibres is a relevant approach to improve the performance of BGs. This study is aimed at characterizing a new, highly porous, fibrous glassy scaffold and evaluating its in vitro and in vivo biocompatibility. The developed scaffolds were characterized in terms of porosity, mineralization and morphological features. Additionally, fibroblast and osteoblast cells were seeded in contact with extracts of the scaffolds to assess cell proliferation and genotoxicity after 24, 72 and 144 h. Finally, scaffolds were placed subcutaneously in rats for 15, 30 and 60 days. The scaffolds presented interconnected porous structures, and the precursor bioglass could mineralize a hydroxyapatite (HCA) layer in simulated body fluid (SBF) after only 12 h. The biomaterial elicited increased fibroblast and osteoblast cell proliferation, and no DNA damage was observed. The in vivo experiment showed degradation of the biomaterial over time, with soft tissue ingrowth into the degraded area and the presence of multinucleated giant cells around the implant. At day 60, the scaffolds were almost completely degraded and an organized granulation tissue filled the area. The results highlight the potential of this fibrous, glassy material for bone regeneration, due to its bioactive properties, non-cytotoxicity and biocompatibility. Future investigations should focus on translating these findings to orthotopic applications. Copyright © 2015 John Wiley & Sons, Ltd.

Biosilicate/PLGA osteogenic effects modulated by laser therapy: In vitro and in vivo studies.

The main purpose of the present work was to evaluate if low laser level therapy (LLLT) can improve the effects of Biosilicate®/PLGA (BS/PLGA) composites on cell viability and bone consolidation using a tibial defects of rats. The composites were characterized by scanning electron microscope (SEM) and reflection Fourier transform infrared spectrometer (FTIR). For the in vitro study, fibroblast and osteoblast cells were seeded in the extract of the composites irradiated or not with LLLT (Ga-Al-As, 808nm, 10J/cm2) to assess cell viability after 24, 48 and 72h. For the in vivo study, 80 Wistar rats with tibial bone defects were distributed into 4 groups (BS; BS+LLLT; BS/PLGA and BS/PLGA+LLLT) and euthanized after 2 and 6weeks. Laser irradiation Ga-Al-As (808nm, 30J/cm2) in the rats was performed 3 times a week. The SEM and FTIR results revealed that PLGA were successfully inserted into BS and the microparticles degraded over time. The in vitro findings demonstrated higher fibroblast viability in both BS/PLGA groups after 24h and higher osteoblast viability in BS/PLGA+LLLT in all periods. As a conclusion, animals treated with BS/PLGA+LLLT demonstrated an improved material degradation and an increased amount of granulation tissue and newly formed bone.

Amplification of growth inhibition by glucocorticoid on L5178Y and L1210 lymphoblasts in vivo.

One component of a factor in Proteus mirabilis (Factor 1) which specifically amplifies the induction of several liver enzymes by glucocorticoid in target cells also increases the growth inhibition of glucocorticoid on the ascitic form of L1210 cells and solid tumors of L5178Y lymphoblasts in vivo. The growth of L5U78Y and L1210 lymphoblasts was inhibited by a triamcinolone acetonide dose of over 0.5 to 1.0 mg/kg body weight. Factor 1 increased the inhibitory effect of a triamcinolone acetonide dose of less than 4.0 mg/kg bodyweight but had little effect on the effects of doses of over 4.0 mg. Factor 1 (10 biological units/kg body weight) itself also caused marked inhibition of the growth of these lymphoblasts without affecting the body weight or adrenal gland weight, its effect being equivalent to that of 3- to 4-mg/kg body weight doses of triamcinolone acetonide alone. There was no significant difference in the level of plasma total corticoids or that of plasma adrenocorticotropic hormone between rats treated with 0.9% NaCl solution or those treated with Factor 1, and Factor 1 had no cytotoxic effec on cultured L5178Y lymphoblasts. Thus, Factor 1 may amplify the effect of physiological level of glucocorticoid in mice sufficiently to inhibit the growth of these lymphoblasts without causing any significant side effects to the host animal.

Interaction of hepatitis B virus X protein with a serine protease, tryptase TL2 as an inhibitor.

X protein of hepatitis B virus (HBV) transactivates transcription of various viral and cellular genes. It has been suggested that X protein plays a major role in hepatocarcinogenesis by HBV. The protein possesses amino acid sequence homology to the functionally essential domain of Kunitz-type serine protease inhibitors. This Kunitz domain-like sequence in X protein is indispensable for the transactivation function. To clarify whether X protein has a serine protease inhibitor activity, a search was made for serine proteases which interact with, but not degrade X protein. Tryptase TL2, one of serine proteases in hepatic cells, was found to directly interact with X protein without degradation. Moreover, the activities of tryptase TL2 and an analogous protease were substantially inhibited by X protein. These results suggest that transactivation function of X protein is exerted by modulation of the hepatic serine protease activity, giving rise to quantitative or qualitative change of cellular transcription factor(s) through protection from proteolytic degradation and/or suppression of processing.

Cloning and expression of novel mosaic serine proteases with and without a transmembrane domain from human lung.

Two cDNAs encoding novel mosaic proteins with a serine protease domain and potential regulatory modules, consisting of a protein kinase substrate and a low-density lipoprotein receptor, were cloned from a human lung cDNA library by PCR. One with a transmembrane domain (MSPL) and the other without one (MSPS) comprise 581 and 537 amino acids, respectively. Except for the C-terminal ends, the two isoforms had an identical serine protease domain exhibiting 42, 39 and 43% identity with those of plasma kallikrein, hepsin and transmembrane protease serine 2, respectively. Both genes were predominantly expressed in human lung, placenta, pancreas and prostate.