Bioinspired 3D scaffolds with antimicrobial, drug delivery, and osteogenic functions for bone regeneration

A major clinical challenge today is the large number of bone defects caused by diseases or trauma. The development of three-dimensional (3D) scaffolds with adequate properties is crucial for successful bone repair. In this study, we prepared biomimetic mesoporous bioactive glass (MBG)-based scaffolds with and without ceria addition (up to 3 mol %) to explore the biological structure and chemical composition of the marine sponge Spongia Agaricina (SA) as a sacrificial template. Micro-CT examination revealed that all scaffolds exhibited a highly porous structure with pore diameters primarily ranging from 143.5 μm to 213.5 μm, facilitating bone ingrowth. Additionally, smaller pores (< 75 μm), which are known to enhance osteogenesis, were observed. The undoped scaffold displayed the highest open porosity value of 90.83%. Cytotoxicity assessments demonstrated that all scaffolds were noncytotoxic and nongenotoxic toward osteoblast cells. Moreover, scaffolds with higher CeO2 content promoted osteogenic differentiation of dental pulp stem cells, stimulating calcium and osteocalcin secretion. The scaffolds also exhibited antimicrobial and antibiofilm effects against Staphylococcus aureus (S. aureus) as well as drug delivery ability. Our research findings indicated that the combination of MBG, natural biological structure, and the addition of Ce exhibited a synergistic effect on the structure and biological properties of scaffolds for applications in bone tissue engineering.

Co- and Ni-Doped TiO2 Nanoparticles Supported on Zeolite Y with Photocatalytic Properties

Zeolite Y samples with microporous and hierarchical structures containing Ti-Ni and Ti-Co oxides were obtained as active photocatalysts. Different Ti amounts (5, 10% TiO2) were supported, followed by the loading of Ni or Co oxides (5%). X-ray diffraction evidenced the presence of TiO2 as an anatase. N2 adsorption-desorption results showed type IV isotherms for hierarchical zeolite Y samples, and a combination of type IV and I isotherms for zeolite Y samples. UV-Vis diffuse reflectance spectra showed a shift in the absorption band to visible with increasing Ti loading and especially after Co and Ni addition. A significant effect of the support was evidenced for Ti and its interaction with Co/Ni species. The zeolite Y support stabilized Ti in the 4+ oxidation state while hierarchical zeolite Y support favored the formation of Ti3+ species, Ni0 and Ni2+ and the oxidation of Co to 3+ oxidation state. Photocatalytic activity, under UV and visible light irradiation, was evaluated by the degradation of amoxicillin, used as a model test. The photocatalytic mechanism was investigated using ethanol, p-benzoquinone and KI as ·OH and ·O2- radicals and hole (h+) scavengers. The best results were obtained for the immobilized Ni-Ti species on the hierarchical zeolite Y support.

Pharmacotechnical, Physico-Chemical, and Antioxidant Evaluation of Newly Developed Capsule Formulations

The excess of free radicals causes numerous imbalances in the body that lead to premature aging, the degradation of internal structures, and the appearance of numerous pathologies responsible for the increased risk of premature death. The present work aims to evaluate the physical, chemical, pharmacotechnical, and antioxidant activity of newly achieved capsule formulations. These two formulations were F1_a.i., which contains melatonin:biotin:coenzyme Q10 (weight ratio of 1:2:60), and F2_a.i., which contains quercetin:resveratrol:biotin:coenzyme Q10 (weight ratio of 10:10:1:10). The adequate selection of the excipient types and amounts for final capsule formulations (F1_c.c., F2_c.c.) was based on preformulation studies performed on the powders containing active ingredients. The antioxidant activity assessed using three methods (ABTS, DPPH, and FRAP) compared with acid ascorbic as a positive control demonstrated that the F2_c.c. formulation possesses the strongest antioxidant capacity. The results confirmed the suitable formulation and the accurate selection of the types and amounts of active ingredients, as well as the auxiliary excipients used in newly developed capsule formulations as supplements with an excellent antioxidant effect on the human body.

New Nanostructured Materials Based on Mesoporous Silica Loaded with Ru(II)/Ru(III) Complexes with Anticancer and Antimicrobial Properties

A new series of nanostructured materials was obtained by functionalization of SBA-15 mesoporous silica with Ru(II) and Ru(III) complexes bearing Schiff base ligands derived from salicylaldehyde and various amines (1,2-diaminocyclohexane, 1,2-phenylenediamine, ethylenediamine, 1,3-diamino-2-propanol, N,N-dimethylethylenediamine, 2-aminomethyl-pyridine, and 2-(2-aminoethyl)-pyridine). The incorporation of ruthenium complexes into the porous structure of SBA-15 and the structural, morphological, and textural features of the resulting nanostructured materials were investigated by FTIR, XPS, TG/DTA, zeta potential, SEM, and N₂ physisorption. The ruthenium complex-loaded SBA-15 silica samples were tested against A549 lung tumor cells and MRC-5 normal lung fibroblasts. A dose-dependent effect was observed, with the highest antitumoral efficiency being recorded for the material containing [Ru(Salen)(PPh₃)Cl] (50%/90% decrease in the A549 cells' viability at a concentration of 70 μg/mL/200 μg/mL after 24 h incubation). The other hybrid materials have also shown good cytotoxicity against cancer cells, depending on the ligand included in the ruthenium complex. The antibacterial assay revealed an inhibitory effect for all samples, the most active being those containing [Ru(Salen)(PPh₃)Cl], [Ru(Saldiam)(PPh₃)Cl], and [Ru(Salaepy)(PPh₃)Cl], especially against Staphylococcus aureus and Enterococcus faecalis Gram-positive strains. In conclusion, these nanostructured hybrid materials could represent valuable tools for the development of multi-pharmacologically active compounds with antiproliferative, antibacterial, and antibiofilm activity.

Safety and Outcome of Revascularization Treatment in Patients With Acute Ischemic Stroke and COVID-19: The Global COVID-19 Stroke Registry

BACKGROUND AND OBJECTIVES

COVID-19-related inflammation, endothelial dysfunction, and coagulopathy may increase the bleeding risk and lower the efficacy of revascularization treatments in patients with acute ischemic stroke (AIS). We aimed to evaluate the safety and outcomes of revascularization treatments in patients with AIS and COVID-19.

METHODS

This was a retrospective multicenter cohort study of consecutive patients with AIS receiving intravenous thrombolysis (IVT) and/or endovascular treatment (EVT) between March 2020 and June 2021 tested for severe acute respiratory syndrome coronavirus 2 infection. With a doubly robust model combining propensity score weighting and multivariate regression, we studied the association of COVID-19 with intracranial bleeding complications and clinical outcomes. Subgroup analyses were performed according to treatment groups (IVT-only and EVT).

RESULTS

Of a total of 15,128 included patients from 105 centers, 853 (5.6%) were diagnosed with COVID-19; of those, 5,848 (38.7%) patients received IVT-only and 9,280 (61.3%) EVT (with or without IVT). Patients with COVID-19 had a higher rate of symptomatic intracerebral hemorrhage (SICH) (adjusted OR 1.53; 95% CI 1.16-2.01), symptomatic subarachnoid hemorrhage (SSAH) (OR 1.80; 95% CI 1.20-2.69), SICH and/or SSAH combined (OR 1.56; 95% CI 1.23-1.99), 24-hour mortality (OR 2.47; 95% CI 1.58-3.86), and 3-month mortality (OR 1.88; 95% CI 1.52-2.33). Patients with COVID-19 also had an unfavorable shift in the distribution of the modified Rankin score at 3 months (OR 1.42; 95% CI 1.26-1.60).

DISCUSSION

Patients with AIS and COVID-19 showed higher rates of intracranial bleeding complications and worse clinical outcomes after revascularization treatments than contemporaneous non-COVID-19 patients receiving treatment. Current available data do not allow direct conclusions to be drawn on the effectiveness of revascularization treatments in patients with COVID-19 or to establish different treatment recommendations in this subgroup of patients with ischemic stroke. Our findings can be taken into consideration for treatment decisions, patient monitoring, and establishing prognosis.

TRIAL REGISTRATION INFORMATION

The study was registered under ClinicalTrials.gov identifier NCT04895462.

In Vitro Anticancer Activity of Mucoadhesive Oral Films Loaded with Usnea barbata (L.) F. H. Wigg Dry Acetone Extract, with Potential Applications in Oral Squamous Cell Carcinoma Complementary Therapy

Oral squamous cell carcinoma (OSCC) is the most frequent oral malignancy, with a high death rate and an inadequate response to conventional chemotherapeutic drugs. Medical research explores plant extracts’ properties to obtain potential nanomaterial-based anticancer drugs. The present study aims to formulate, develop, and characterize mucoadhesive oral films loaded with Usnea barbata (L.) dry acetone extract (F-UBA) and to investigate their anticancer potential for possible use in oral cancer therapy. U. barbata dry acetone extract (UBA) was solubilized in ethanol: isopropanol mixture and loaded in a formulation containing hydroxypropyl methylcellulose (HPMC) K100 and polyethylene glycol 400 (PEG 400). The UBA influence on the F-UBA pharmaceutical characteristics was evidenced compared with the references, i.e., mucoadhesive oral films containing suitable excipients but no active ingredient loaded. Both films were subjected to a complex analysis using standard methods to evaluate their suitability for topical administration on the oral mucosa. Physico-chemical and structural characterization was achieved by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and atomic force microscopy (AFM). Pharmacotechnical evaluation (consisting of the measurement of specific parameters: weight uniformity, thickness, folding endurance, tensile strength, elongation, moisture content, pH, disintegration time, swelling rate, and ex vivo mucoadhesion time) proved that F-UBAs are suitable for oral mucosal administration. The brine shrimp lethality (BSL) assay was the F-UBA cytotoxicity prescreen. Cellular oxidative stress, caspase 3/7 activity, nuclear condensation, lysosomal activity, and DNA synthesis induced by F-UBA in blood cell cultures and oral epithelial squamous cell carcinoma (CLS-354) cell line were investigated through complex flow cytometry analyses. Moreover, F-UBA influence on both cell type division and proliferation was determined. Finally, using the resazurin-based 96-well plate microdilution method, the F-UBA antimicrobial potential was explored against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27353, Candida albicans ATCC 10231, and Candida parapsilosis ATCC 22019. The results revealed that each UBA-loaded film contains 175 µg dry extract with a usnic acid (UA) content of 42.32 µg. F-UBAs are very thin (0.060 ± 0.002 mm), report a neutral pH (7.01 ± 0.01), a disintegration time of 146 ± 5.09 s, and an ex vivo mucoadhesion time of 85 ± 2.33 min, and they show a swelling ratio after 6 h of 211 ± 4.31%. They are suitable for topical administration on the oral mucosa. Like UA, they act on CLS-354 tumor cells, considerably increasing cellular oxidative stress, nuclear condensation, and autophagy and inducing cell cycle arrest in G0/G1. The F-UBAs inhibited the bacterial and fungal strains in a dose-dependent manner; they showed similar effects on both Candida sp. and higher inhibitory activity against P. aeruginosa than S. aureus. All these properties lead to considering the UBA-loaded mucoadhesive oral films suitable for potential application as a complementary therapy in OSCC.

Evaluation of Usnea barbata (L.) Weber ex F.H. Wigg Extract in Canola Oil Loaded in Bioadhesive Oral Films for Potential Applications in Oral Cavity Infections and Malignancy

Usnea lichens are known for their beneficial pharmacological effects with potential applications in oral medicine. This study aims to investigate the extract of Usnea barbata (L.) Weber ex F.H. Wigg from the Călimani Mountains in canola oil as an oral pharmaceutical formulation. In the present work, bioadhesive oral films (F-UBO) with U. barbata extract in canola oil (UBO) were formulated, characterized, and evaluated, evidencing their pharmacological potential. The UBO-loaded films were analyzed using standard methods regarding physicochemical and pharmacotechnical characteristics to verify their suitability for topical administration on the oral mucosa. F-UBO suitability confirmation allowed for the investigation of antimicrobial and anticancer potential. The antimicrobial properties against Staphylococcus aureus ATCC 25923, Pseudomonas aeruginosa ATCC 27353, Candida albicans ATCC 10231, and Candida parapsilosis ATCC 22019 were evaluated by a resazurin-based 96-well plate microdilution method. The brine shrimp lethality assay (BSL assay) was the animal model cytotoxicity prescreen, followed by flow cytometry analyses on normal blood cells and oral epithelial squamous cell carcinoma CLS-354 cell line, determining cellular apoptosis, caspase-3/7 activity, nuclear condensation and lysosomal activity, oxidative stress, cell cycle, and cell proliferation. The results indicate that a UBO-loaded bioadhesive film’s weight is 63 ± 1.79 mg. It contains 315 µg UBO, has a pH = 6.97 ± 0.01, a disintegration time of 124 ± 3.67 s, and a bioadhesion time of 86 ± 4.12 min, being suitable for topical administration on the oral mucosa. F-UBO showed moderate dose-dependent inhibitory effects on the growth of both bacterial and fungal strains. Moreover, in CLS-354 tumor cells, F-UBO increased oxidative stress, diminished DNA synthesis, and induced cell cycle arrest in G0/G1. All these properties led to considering UBO-loaded bioadhesive oral films as a suitable phytotherapeutic formulation with potential application in oral infections and neoplasia.

New Hybrid Nanofiltration Membranes with Enhanced Flux and Separation Performances Based on Polyphenylene Ether-Ether-Sulfone/Polyacrylonitrile/SBA-15

This study presents the preparation of hybrid nanofiltration membranes based on poly(1,4-phenylene ether ether sulfone), polyacrylonitrile, poly(vinyl pyrrolidone), and SBA-15 mesoporous silica. Laser treatment of polymeric solutions to enhance the hydrophilicity and performance of membranes was investigated. The membranes’ structure was characterized using scanning electron (SEM) and atomic force (AFM) microscopy and contact angle measurements. The addition of PAN in the casting solution produced significant changes in the membrane structure, from finger-like porous structures to sponge-like porous structures. Increased PAN concentration in the membrane composition enhanced the hydrophilicity of the membrane surface, which also accounted for the improvement in the antifouling capabilities. The permeation of apple pomace extract and the content of polyphenols and flavonoids were used to evaluate the efficacy of the hybrid membranes created. The results showed that the hybrid nanofiltration membranes based on PPEES/PAN/PVP/SBA-15: 15/5/1/1 and 17/3/1/1 exposed to laser for 5 min present a higher rejection coefficient to total polyphenols (78.6 ± 0.7% and 97.8 ± 0.9%, respectively) and flavonoids (28.7 ± 0.2% and 50.3 ± 0.4%, respectively) and are substantially better than a commercial membrane with MWCO 1000 Da or PPEES-PVP-based membrane.

AB0693 EFFECTIVENESS OF RITUXIMAB IN PATIENTS WITH SYSTEMIC SCLEROSIS – EXPERIENCE IN A TERTIARY MEDICAL CENTER

Background

There is ample evidence of B cell involvement in the pathogenesis of fibrosis in systemic sclerosis (SSc), making it a promising target for the treatment of skin and lung fibrosis in SSc. However, data regarding the long-term use of B cell depletion in the treatment of this life-threatening connective tissue disease is scarce.

Objectives

The primary aim of this study was to evaluate the safety and efficacy of long-term B cell depletion and to define the changes on both cutaneous and visceral organ involvement after rituximab (RTX) therapy in SSc patients over time, in a tertiary hospital.

Methods

A prospective observational case-control study, conducted between 2016 and 2021, enrolled 10 SSc patients, who fulfilled the ACR/EULAR 2013 classification criteria for scleroderma and who had received RTX infusions at least once. All patients had been taking immunosuppressive therapy previously.The following clinical data were included into the analysis: disease activity by the EUSTAR activity index, skin fibrosis by the modified Rodnan Skin Score (mRSS), interstitial lung disease by lung function tests including forced vital capacity (FVC), diffusing capacity of the lung for carbon monoxide (DLCO) and high-resolution CT (HRCT). For the comparison of non-parametric data at two time points, Wilcoxon matched paired Student’s t-test was used.

Results

The study included 10 patients (all female), with a mean age of 52.9 years, most of them with diffuse subset (9/10), treated with RTX between 2016 and 2021. Average duration of disease before the RTX therapy was 27.6 months. Mean baseline mRSS was 19.3 and mean EUSTAR activity index was 4.48. Seven patients received 2 courses of RTX for at least 6 months, four of which were evaluated 1 year after the beginning of RTX therapy. We found a statistically significant improvement in mRSS (p=0.02) and EUSTAR activity index values (p=0.02), when comparing baseline levels with those found at each follow-up visit. Furthermore, all the patients who were treated with RTX early in the disease course achieved better results at 6 months follow-up. There was no significant change in PFT’s, DLCO and chest HRCT lesions in all patients, neither in the subgroup with early disease, nor in the subgroup with worsening, progressing pulmonary function, during the follow up period.

Conclusion

Our results suggest that B cell depletion, in patients with SSc, leads mainly to a clinically relevant decrease in skin involvement and to a stabilization of disease activity after 6 and 12 months of use. The study did not find a clear beneficial effect on pulmonary function during short-term follow-up. Despite these considerations, our results indicate that the course of lung disease did not worsen in our patients. At 6-year follow-up the safety of single and repeated courses of the drug was confirmed. While the study provides important insights into the use of RTX in SSc, it is limited by the low number of patients, the lack of a sufficient control arm and the single center design.

References

[1]Bosello SL, De Luca G, Rucco M, Berardi G, Falcione M, Danza FM, Pirronti T, Ferraccioli G. Long-term efficacy of B cell depletion therapy on lung and skin involvement in diffuse systemic sclerosis. Semin Arthritis Rheum. 2015 Feb;44(4):428-36. doi: 10.1016/j.semarthrit.2014.09.002. Epub 2014 Sep 8. PMID: 25300701.

Disclosure of Interests

None declared

AB0713 Calcinosis cutis - independent risk factor for all-cause mortality in SSc patients

Background

Calcinosis is a common and disabling complication of systemic sclerosis (SSc) with poorly understood pathogenesis and no effective treatment. Little is known about the etiology of this condition and management is essentially based on case studies and series.

Objectives

The objectives of this study were to describe the prevalence and characteristics of calcifications, and to investigate the relationships between calcinosis and clinical features in a population of patients with SSc.

Methods

This was a single center descriptive and retrospective study of patients treated at “Saint Mary” Clinical Hospital in Bucharest since January 2000 for SSc. Demographic and clinical features, including duration of disease progression, symptoms and parameters related to a specific organ involvement according to MEDS evaluation sheets, were evaluated in all patients. For testing the association between nominal variables chi-square test was performed while independent t test was used to compare the differences between subgropus.Logistic regression analysis was used to predict the risk of all-cause mortality.

Results

154 SSc patients were selected in the database, from which we identified a final group of 31 (20%) patients with calcinosis related to systemic sclerosis. The calcinosis cohort comprised 25 females and 6 males, with a mean age of 52.6 (±14.3) years, most of them with diffuse subset (16/31). Mean disease duration was 5.6 years (±3.1). Mean modified Rodnan skin score (mRSS) was 9.46 (±3.4) and mean adjusted EScSG activity index in the subgroup with calcinosis was 3.6 (±1.9). 45.16% (14/31) patients from the calcinosis subgroup developed interstitial lung disease (ILD) vs 43.9%; pulmonary hypertension was seen in 51.6% (16/31) cases vs 10.5% (13/123).

As expected, calcifications were closely associated with vascular (p=0.004) and gastrointestinal (p=0.001) involvement and pulmonary hypertension (p=0.049). Moreover, associations were stronger for severe gastrointestinal involvement defined as chronic intestinal pseudo-obstruction (p=0.001). Females (p=0.024), patients with digital ulcers (p=0.004), those with disease duration longer than 10 years (p=0.001), those with pulmonary hypertension (p=0.049) and patients with gastrointestinal involvement (p=0.044) presented significantly more calcinosis. There were no significant associations between calcinosis and disease activity, myositis, interstitial lung disease, type of scleroderma or autoantibodies.

Furthermore, in the logistic regression equation we identified calcinosis as a risk factor for all-cause mortality in SSc patients [OR:2.607 (CI:1.062,6,397), p=0.037].

Conclusion

Calcinosis cutis is a common manifestation is patients with SSc regardless of skin subset and type of autoantibodies. It seems to occur more often in patients with long-standing disease and is more commonly associated with vascular involvement such as digital ulcers and pulmonary hypertension. Furthermore, the present study has demonstrated that calcinosis could be an important prognostic factor when it comes to predict mortality. Given the fact that the management of calcinosis in scleroderma is an unmet need in almost half of patients with long-standing disease duration, systematic clinical trials are required to find effective measures to prevent this complication.

References

[1]Richardson C, Plaas A, Varga J. Calcinosis in Systemic Sclerosis: Updates in Pathophysiology, Evaluation, and Treatment. Curr Rheumatol Rep. 2020 Aug 27;22(10):73. doi: 10.1007/s11926-020-00951-2. PMID: 32856128.

[2]Jinnin M. ‘Narrow-sense’ and ‘broad-sense’ vascular abnormalities of systemic sclerosis. Immunol Med. 2020 Sep;43(3):107-114. doi: 10.1080/25785826.2020.1754692. Epub 2020 Apr 23. PMID: 32324110.

[3]Chander S, Gordon P. Soft tissue and subcutaneous calcification in connective tissue diseases. Curr Opin Rheumatol. 2012 Mar;24(2):158-64. doi: 10.1097/BOR.0b013e32834ff5cd. PMID: 22227955

Disclosure of Interests

None declared

Influence of Ceria Addition on Crystallization Behavior and Properties of Mesoporous Bioactive Glasses in the SiO2–CaO–P2O5–CeO2System

Knowledge of the crystallization stability of bioactive glasses (BGs) is a key factor in developing porous scaffolds for hard tissue engineering. Thus, the crystallization behavior of three mesoporous bioactive glasses (MBGs) in the 70SiO₂-(26-x)CaO-4P₂O₅-xCeO₂ system (x stands for 0, 1 and 5 mol. %, namely MBG(0/1/5)Ce), prepared using the sol–gel method coupled with the evaporation-induced self-assembly method (EISA), was studied. A thermal analysis of the multiple-component crystallization exotherms from the DSC scans was performed using the Kissinger method. The main crystalline phases of Ca₅(PO₄)2.823(CO₃)_0.22O, CaSiO₃ and CeO₂ were confirmed to be generated by the devitrification of the MBG with 5% CeO₂, MBG5Ce. Increasing the ceria content triggered a reduction in the first crystallization temperature while ceria segregation took place. The amount of segregated ceria of the annealed MBG5Ce decreased as the annealing temperature increased. The optimum processing temperature range to avoid the crystallization of the MBG(0/1/5)Ce powders was established.

Cerium-Containing Mesoporous Bioactive Glasses (MBGs)-Derived Scaffolds with Drug Delivery Capability for Potential Tissue Engineering Applications

Finding innovative solutions to improve the lives of people affected by trauma, bone disease, or aging continues to be a challenge worldwide. Tissue engineering is the most rapidly growing area in the domain of biomaterials. Cerium-containing MBG-derived biomaterials scaffolds were synthesized using polymethyl methacrylate (PMMA) as a sacrificial template. The obtained scaffolds were characterized by X-ray powder diffraction (XRPD), infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). The Ce4+/Ce3+ ratio in the scaffolds was estimated. In vitro testing revealed good cytocompatibility of the investigated scaffolds in mouse fibroblast cell line (NCTC clone L929). The results obtained regarding bioactivity, antibacterial activity, and controlled drug delivery functions recommend these scaffolds as potential candidates for bone tissue engineering applications.

Manufacturing and Assessing the New Orally Disintegrating Tablets, Containing Nimodipine-hydroxypropyl-β-cyclodextrin and Nimodipine-methyl-β-cyclodextrin Inclusion Complexes

The aim of the present study was to manufacture new orally disintegrating tablets containing nimodipine-hydroxypropyl-β-cyclodextrin and nimodipine-methyl-β-cyclodextrin inclusion complexes. For obtaining a better quality of the manufactured tablets, three methods of the preparation of inclusion complexes, in a 1:1 molar ratio, were used comparatively; namely, a solid-state kneading method and two liquid state coprecipitation and lyophilization techniques. The physical and chemical properties of the obtained inclusion complexes, as well as their physical mixtures, were investigated using Fourier transformed infrared spectroscopy, scanning electron microscopy, X-ray diffraction analyses, and differential scanning calorimetry. The results showed that the lyophilization method can be successfully used for a better complexation. Finally, the formulation and precompression studies for tablets for oral dispersion, containing Nim-HP-β-CD and Nim-Me-β-CD inclusion complexes, were successfully assessed.

Isothermal Oxidation Behavior of Novel Al2O3 / NiCrAlY / Ti3Al System at 850�C

The novel Al2O3 / NiCrAlY /alfa2-Ti3Al system obtained by APS technique was tested against long (500h) isothermal oxidation at 850�C in air for prospective use in aerospace applications. EDX-SEM, X-ray diffraction (XRD) and Raman investigations were conducted to substantiate structural, textural and mass gain modifications underwent by the Al2O3 / NiCrAlY /alfa2-Ti3Al system in comparison with bare alfa2-Ti3Al and NiCrAlY /alfa2-Ti3Al system. Improved oxidation resistance of the double-coated system is based on moderate oxygen and thermal barrier role played by the mixture of delta - and alfa-Al2O3 present in the top ceramic coat.

Cellulose defibrillation and functionalization by plasma in liquid treatment

Submerged liquid plasma (SLP) is a new and promising method to modify powder materials. Up to now, this technique has been mostly applied to carbonaceous materials, however, SLP shows great potential as a low-cost and environmental-friendly method to modify cellulose. In this work we demonstrate the modification of microcrystalline cellulose (MCC) by applying the SLP combined with ultrasonication treatments. The plasma generated either in an inert (argon) or reactive (argon: oxygen or argon:nitrogen) gas was used in MCC dispersions in water or acetonitrile:water mixtures. An enhanced defibrillation of MCC has been observed following the application of SLP. Furthermore, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy have been applied to investigate the surface functionalization of MCC with oxygen or nitrogen moieties. Depending on the plasma treatment applied, poly (3-hydroxybutyrate) composites fabricated with the plasma modified cellulose fibers showed better thermal stability and mechanical properties than pristine PHB. This submerged liquid plasma processing method offers a unique approach for the activation of cellulose for defibrillation and functionalization, aiming towards an improved reinforcing ability of biopolymers.

Antimicrobial Features of Organic Functionalized Graphene-Oxide with Selected Amines

(1) Background: Graphene oxide is a new carbon-based material that contains functional groups (carboxyl, hydroxyl, carbonyl, epoxy) and therefore can be easily functionalized with organic compounds of interest, yielding hybrid materials with important properties and applications. (2) Methods: Graphene oxide has been obtained by a modified Hummers method and activated by thionyl chloride in order to be covalently functionalized with amines. Thus obtained hybrid materials were characterized by infrared and Raman spectroscopy, elemental analysis and scanning electron microscopy and then tested for their antimicrobial and anti-biofilm activity. (3) Results: Eight amines of interest were used to functionalize grapheme oxide and the materials thus obtained were tested against Gram-negative (Escherichia coli, Pseudomonas aeruginosa) and Gram-positive (Staphylococcus aureus) bacterial strainsin plankonic and biofilm growth state. Both amines, as well as the functionalized materials, exhibited anti-microbial features. Three to five functionalized graphene oxide materials exhibited improved inhibitory activity against planktonic strains as compared with the respective amines. In exchange, the amines alone proved generally more efficient against biofilm-embedded cells. (4) Conclusions: Such hybrid materials may have a wide range of potential use in biomedical applications.

CT vs. MRCP in choledocholithiasis jaundice

RATIONALE

Obstructive jaundice can raise problems to diagnostic imaging. The radiologist must choose the most appropriate examination that delivers the most important diagnostic information because the differences between a lithiasic obstruction and a tumoral one are vital. This information helps the surgeon speed up the process of decision-making, because the treatment may be very different in relation to the nature of the obstruction.

OBJECTIVE

This study tries to demonstrate the diagnostic accuracy of computed tomography (CT) and magnetic resonance cholangiopancreatography (MRCP) in detecting the obstacle in the common bile duct (CBD) and the possibility of establishing the lithiasic nature of the obstruction.

METHODS AND RESULTS

A retrospective analysis was analyzed during an interval of 18 months that included jaundice patients admitted in the General Surgery Department of "Coltea" Clinical Hospital. They were examined by CT scanning and by MRCP, being suspected of choledocholithiasis. 63 patients were included in the study, 34 females and 29 males. 33 CT scans and 30 MRCP exams were performed.

DISCUSSION

CT scan is useful in detecting residual or iterative choledocholithiasis in patients after cholecystectomy, contrast enhanced CT (CECT), being able to differentiate between lithiasic and non-lithiasic obstruction. MRCP delivers important anatomic details of the biliary tree; it is superior to CT in diagnosing the hepatocholedochal lithiasis; MRCP tends to replace endoscopic retrograde cholangiopancreatography (ERCP)--the diagnostic "gold standard" reducing the number of unnecessary invasive diagnostic procedures.

Growth hormone response to clonidine administration for evaluation of autonomic dysfunction in multiple sclerosis patients

OBJECTIVES

Our objective was to assess the dynamic serum growth hormone (GH) response to clonidine administration in multiple sclerosis patients, looking for a possible biomarker of degenerative process and to correlative with disability.

METHODS

21 patients with relapsing remitting multiple sclerosis, who were evaluated clinically by expanded disability status scale (EDSS) score and multiple sclerosis functional composite (MSFC) score and for whom we measured the GH before and one hour after oral clonidine administration.Different cut-off values of EDSS score were chosen for observation of GH serum dynamics after clonidine administration. All patients had normal IGF1 values.

RESULTS

There was a significant positive correlation between EDSS and time to walk 25 feet (r = 0.5, p = 0.002) and EDSS and nine holes peg tests for dominant and non dominant hands (r = 0.37, p = 0.024 and r = 0.53, p = 0.001, respectively).There was a moderate negative correlation, significant statistically, between EDSS and paced auditory serial additional test (PASAT) (r= -0.36, p= 0.046).4 out of 7 patients with EDSS score over 3.0 failed to increase serum GH levels after clonidine administration, as compared to 4 out of 14 patients with EDSS < 3 (r = 1.6; p=0.02), revealed by means of the Pearson chi square test.

CONCLUSION

Despite the small number of subjects enrolled in this pilot study, there is a tendency of blunted GH response in patients with more severe physical disability (stated by an increased value of EDSS), suggesting that GH response to clonidine could assess central autonomic dysfunction in MS patients.

Optic nerve assessment identifies biomarkers of axonal pathology in multiple sclerosis

Our aim was to identify possible correlations between physical disabilities assessed by expanded disability status score (EDSS) and neurodegenerative process measured by retinal nerve fibers thickness, and also with demyelization process measured by visual evoked potential with P100 wave latency at optic nerve level on patients diagnosed with multiple sclerosis (MS). This study aimed to find a structural biomarker at central nerve system (CNS) level which could correlate with clinical disability. The optic nerve is an accessible structure of CNS easy to investigate. We analyzed a population of 111 patients diagnosed with different clinical forms of multiple sclerosis based on 2005 revised Mc Donald criteria, for whom we assessed clinical disability by EDSS, and by different subscales of multiple sclerosis composite (MSFC) as timed to walk 25 foot (TW25F) and nine hole peg test (9HPT). Optic nerve involvement was assessed for each eye measuring visual acuity (VA) (Snellen chart), P100 wave latency by visual evoked potential (VEP) and retinal nerve fiber layer thickness (RNFL) by optical coherence tomography (OCT). The medium age of our population was 38.09 and the medium EDSS was 3.3. – 76 out of 111 were women. 79 patients were diagnosed with relapsing remitting (RR) MS, 7 with clinically isolated syndrome (CIS), the other were diagnosed with progressive form of MS: 7 with primary progressive MS and one with primary progressive with relapse MS. We obtained positive correlations, and statistically significant between EDSS and 9HPT for dominant hand (r=0.58, p = 0.0001) and also for non dominant hand (r = 0.66, p = 0.0001) using Pearson correlation. EDSS score correlates statistically significant with P100 wave latency and visual acuity for both eyes using Pearson correlation, so we obtained negative correlation between EDSS and VA for right eye (r = -0.45, p = 0.0001), and for left eye (r = -0.49, p = 0.0001). We also observed statistically significant positive correlation between EDSS and P100 wave latency for right eye (r = 0.405, p = 0.0001), and left eye (r = 0.400, p = 0.0001). RNFL doesn’t correlate with EDSS, VA or P100 wave latency. Using chi square correlation between EDSS score (we choose a cut of value of 3) and pathological value of RNFL by OCT we didn’t obtain a statistical significant result. The results were : for right eye phi = 0.01, p = 0.9), and for left eye (phi = -0.1, p = 0.3). Similar results were obtained for EDSS of 4.0. The results were: for right eye (phi=-0.009, p= 0.9), and for left eye (phi = 0.017, p = 0.8). In conclusion, in order to understand the pathology of multiple sclerosis the anterior optic nerve pathway offers an attractive model. Optic nerve assessment can be realized through non-invasive complementary methods. Functional and structural data of optic nerve can be obtained by VA measurement, VEP and OCT assessments. Our study showed that axonal pathology of the optic nerve (part of CNS exclusively composed by white matter) correlates with clinical disability measured by EDSS, suggesting that P100 latency is a functional biomarker of the disease. A prospective study to validate such a marker of the progression of the disease is needed.

[Optic neuropathy in multiple sclerosis]

The inflammation of the optic nerve called optic neuropathy could be an onset marker of multiple sclerosis. The authors review the place of optic neuropathy (neuritis) in the inflammatory demyelinating disease continuum, especially as the onset symptom of multiple sclerosis. We present the clinical symptoms, the aetiology of optic neuritis and the adjacent methods used to investigate optic neuritis. In the article are presented the actual criteria used to establish the multiple sclerosis diagnosis and the revised criteria for optic neuromyelitis, with emphasis on the differential diagnosis between these diseases.

[Diagnostic criteria in acute neuromyelitis]

Neuromyelitis optica, also known as Devic disease, was identified in the 19th century, is one of the inflammatory idiopathic demyelinating diseases of the central nervous system, often mistaken for severe multiple sclerosis. In 1999 it had been proposed diagnostic criteria for neuromyelitis optica, but in 2006 these criteria were revised by Dean Wingerchuck. These criteria are 99% sensitive and 90% specific for differentiating neuromyelitis optica from multiple sclerosis that present with optic neuritis or a myelitis syndrome. In the following article we present clinical, spinal and cerebral MR imaging, serological and aspects of cerebrospinal fluid examination features of neuromyelitis optica and the revised criteria of neuromyelitis optica established in 2006. The recently identified serum antibody biomarker: neuromyelitis optica immunoglobulin G (NMO Ig G), which target aquaporin 4 water channel, distinguish neuromyelitis optica from multiple sclerosis, is one of the revised criteria of neuromyelitis optica.

The solution NMR structure of glucosylated N-glycans involved in the early stages of glycoprotein biosynthesis and folding

Glucosylated oligomannose N-linked oligosaccharides (Glc(x)Man9GlcNAc2 where x = 1-3) are not normally found on mature glycoproteins but are involved in the early stages of glycoprotein biosynthesis and folding as (i) recognition elements during protein N-glycosylation and chaperone recognition and (ii) substrates in the initial steps of N-glycan processing. By inhibiting the first steps of glycan processing in CHO cells using the alpha-glucosidase inhibitor N-butyl-deoxynojirimycin, we have produced sufficient Glc3Man7GlcNAc2 for structural analysis by nuclear magnetic resonance (NMR) spectroscopy. Our results show the glucosyl cap to have a single, well-defined conformation independent of the rest of the saccharide. Comparison with the conformation of Man9GlcNAc2, previously determined by NMR and molecular dynamics, shows the mannose residues to be largely unaffected by the presence of the glucosyl cap. Sequential enzymatic cleavage of the glucose residues does not affect the conformation of the remaining saccharide. Modelling of the Glc3Man9GlcNAc2, Glc2Man9GlcNAc2 and Glc1Man9GlcNAc2 conformations shows the glucose residues to be fully accessible for recognition. A more detailed analysis of the conformations allows potential recognition epitopes on the glycans to be identified and can form the basis for understanding the specificity of the glucosidases and chaperones (such as calnexin) that recognize these glycans, with implications for their mechanisms of action.

Immunoaffinity chromatography on antibodies immobilized on nitrocellulose powder

A method is described for the use of nitrocellulose powder as a solid phase in a chromatographic procedure, for the immunoaffinity isolation of proteins. Two different immunoglobulins (Igs), anti-Datura innoxia lectin and anti-tyrosinase, were coupled to particulate nitrocellulose. A single step was then needed for purification to homogeneity of both D. innoxia lectin and mouse tyrosinase. Chaotropic and acidic agents proved to be effective in eluting antigens from Ig-nitrocellulose columns. The binding capacity of particulate nitrocellulose was around 3 mg Ig per milliliter of nitrocellulose, while the purification yields of the two proteins investigated under various eluting conditions were higher than 75%. The applicability of this method in the identification of metabolically labeled proteins in crude extracts is also demonstrated. Purification of proteins by affinity chromatography on their specific Igs linked to nitrocellulose matrices could be performed in both batch and column. The major advantages of this new method for purification of proteins are its rapidity, the reusability of the affinity matrices, and the high yields of purified protein obtained. The method could be seen as an alternative to the widely used immunoprecipitation technique.

[Methodological considerations regarding the applicative study of the dietary level and state of health indicators in the rural population]

The authors present their own experience on the methodology used for investigating the rural dietary phenomenon. The epidemiological investigations were qualitative-quantitative using a personally deviced card to which it was arrived after successive improvements. The aspects connected with the food consumption, criteria of choosing the unities of consumption, reference type and selection of the used clinical indicators are discussed.

[Current data on the biology and response to insecticides of Anopheles mosquitoes in former endemic zones of southern Romania]

In the 1976-1980 period biological and ecologic investigations were carried out on the Anopheles fauna in the former endemic malarial areas in the Danube plains and the Dobrogea. Due to the changes in the ecology of the region new aspects were observed among this fauna: 1) reduced anopheles density as compared to previous years; 2) change in the proportion of the Anopheles species; 3) resistance of the Anopheles to organochloride insecticides and sensitivity to organophosphoric and carbamate insecticides. The authors recommend the use of the Ficam W insecticide in doses of 0.3 g active substance per square meter for disinfestation against mosquitoes in houses.

[Action of some chemical products--insecticides and detergents--on the larvae of mosquitoes of Anopheles labranchiae atroparvus and Culex pipiens autogenicus species]

The larvicide effects of some insecticides and detergents on the Anopheles labranchiae atroparvus species--laboratory colonie--and Culex pipiens autogenicus species, living in flooded basements of some block-houses in the town of Slobozia, were estimated. These products were classified in some categories, depending on their effects: 1. knock-down effect products ; 2. products having a relatively strong effect ; 3. products having a slow effect ; 4. products with a slight effect. Remanence tests were performed on Culex pipiens autogenicus, which showed that Toxid and Lindatox have a longer remanence than the other substances used. In mosquito larvae field control 1 ppm pyrethrum products like Decis and Isathrine, trichlorfon products like Clorofos, Dipterex and Dimetox and organophosphorus carbetox on both species are recommended.