Characterization and immunosuppressive properties of mesenchymal stem cells from periapical lesions

AIM

Mesenchymal stem cells (MSCs) isolated from healthy dental tissues are being investigated as an alternative source of MSCs for the treatment of damaged tissues and inflammatory diseases. Here we investigated whether MSCs from periapical lesions (PL-MSCs) also possess multi-lineage differentiation capacity and immunomodulatory properties.

MATERIAL & METHODS

PL-MSCs, isolated by collagenase/DNAse digestion from surgically extracted PLs, were compared with MSCs from non-inflamed dental pulp (DP-MSCs) and dental follicle (DF-MSCs) for their phenotype and multi-potent differentiation potential. The anti-inflammatory and immunomodulatory effects of PL-MSCs were studied in co-culture with peripheral blood mononuclear cells (PB-MNCs) and PL-inflammatory cells (PL-ICs).

RESULTS

PL-MSCs were characterized by typical MSCs phenotype, lower clonogenicity and self-renewal rate, compared to DF-MSCs and DP-MSCs. These cells possess the potential to differentiate into adipocyte-, osteoblast- and chondrocyte-like cells in vitro, which differs from that of DP-MSCs and DF-MSCs. PL-MSCs inhibited phytohemaglutinine-induced proliferation of PB-MNCs and production of IL-2, IFNγ and IL-5 in the co-culture, probably via TGF-β-dependent mechanisms. These cells also suppressed the production of IL-1β, IL-6, and TNF-α by PL-ICs via soluble mediators, whereas the suppression of IL-8 production required a direct cell-to-cell contact.

CONCLUSION

The differentiation potential of PL-MSCs and their immunosuppressive/anti-inflammatory properties could be beneficial for the treatment of chronic periodontal diseases.

Immunomodulatory properties of nanoparticles obtained by ultrasonic spray pirolysis from gold scrap

We prepared 5 different fractions of nanoparticles from the gold scrap, by using a new technology, Ultrasonic Spray Pirolysis (USP). The aim of this study was to characterize the microstructure and cytotoxicity of the nanoparticles along with their immunomodulatory properties, using Concanavaline A (ConA)-treated rat splenocytes as a model of activated immune cells. Fractions 1 and 2, composed of pure gold nanoparticles, although non-cytotoxic, reduced cellular proliferation. Fraction 2, containing particles smaller in size and lesser agglomerated than fraction 1, up- and down-regulated the production of IL-2 and IL-10, respectively, by activated splenocytes. Fraction 3, containing nanoparticles composed of Au and up to 3 at.% Cu, was non-cytotoxic, but reduced IL-2 production and cell proliferation. Fractions 4 and 5, contaminated with alloying elements from the gold scrap, were cytotoxic. The extent of cytotoxicity and subsequent reduction of cytokine production, as well as the mode of cell death, depended on their composition. In conclusion, we showed that USP enables the synthesis of gold nanoparticles, which could be suitable for various biological applications, and that ConA-treated splenocytes represent a reliable model for fast and accurate evaluation of the immunotoxicological profiles of these particles. However, it is necessary to improve this technology and investigate further some of the immunomodulatory mechanisms using more specific immunological tests.

Synchronous bilateral infiltrating syringomatous adenoma of the breast

Infiltrating syringomatous breast adenoma is an uncommon mammary neoplasm composed of angulated glandular structures with a variable amount of epidermoid differentiation which proliferate in a background of dense collagenous stroma. The patient presented with bilateral hardness and oedema of the nipples. Ultrasound and mammography revealed microcalcifications in retromammilary regions of both nipples. Histological examination of the resected specimens showed angulated glands and solid cords, lined by an inner layer of epithelial cells and an outer layer of myoepithelial cells, immersed in desmoplastic stroma. Within the solid cords reminiscent of squamous cells, occasionally aggregated in keratinizing cysts were found. To the best of our knowledge this is the first described case of bilateral infiltrating syringomatous breast adenoma with synchronous presentation. Infiltrating syringomatous adenoma is a rare lesion. A finding of infiltrating syringomatous adenoma in one breast should prompt careful examination of the opposite breast with adequate follow-up.

Response of monocyte-derived dendritic cells to rapidly solidified nickel-titanium ribbons with shape memory properties

Ni-Ti Shape Memory Alloys (SMAs) have attracted considerable attention as biomaterials for medical devices. However, the biocompatibility of Ni-Ti SMAs is often unsatisfactory due to their poor surface structure. Here we prepared Rapidly Solidified (RS) Ni-Ti SMA ribbons by melt-spinning and their surface was characterised by Auger-electron spectroscopy, X-ray photoelectron spectrometry and scanning electron microscopy. The biocompatibility of the produced ribbons and their immunomodulatory properties were studied on human monocyte-derived dendritic cells (MoDCs). We showed that melt-spinning of Ni-Ti SMAs can form a thin homogenous oxide layer, which improves their corrosion resistance and subsequent toxicity to MoDCs. Ni-Ti RS ribbons stimulated the maturation of MoDCs, as detected by changes in the cells' morphology and increased expression of HLA-DR, CD86, CD40 and CD83 molecules. However, Ni-Ti RS ribbons enhanced the tolerogenic properties of immature MoDCs, which produced higher levels of IL-10 and IL-27, driving the differentiation of IL-10- and TGF-β-producing CD4+T cells. On the other hand, in the presence of lipopolysaccharide, an important pro-inflammatory biomolecule, Ni-Ti RS ribbons enhanced the allostimulatory and Th1 polarising capacity of MoDCs, whereas the production of Th2 and Th17 cytokines was down-regulated. In conclusion, Ni-Ti RS ribbons possess substantial immunomodulatory properties on MoDCs. These findings might be clinically relevant, because implanted Ni-Ti SMA devices can induce both desired and adverse effects on the immune system, depending on the microenvironmental stimuli.

Parallel implementation of the ab initio CRYSTAL program: electronic structure calculations for periodic systems

CRYSTAL is an ab initio electronic structure program, based on the linear combination of atomic orbitals, for periodic systems. This paper concerns the ability of CRYSTAL to exploit massively parallel computer hardware. A brief review of the theory, numerical implementations and parallel solutions will be given and some of the functionalities and capabilities highlighted. Some features that are unique to CRYSTAL will be described and development plans outlined.

Manning free counterion fraction for a rodlike polyion: aqueous solutions of short DNA fragments in presence of very low added salt

We quantified the Manning free (uncondensed) counterions fraction θ for dilute aqueous solutions of rodlike polyions: 150 bp DNA fragments, in the presence of a very low concentration of monovalent salt c(salt)<0.05 mM. Conductivity measurements of these solutions for DNA base pair concentration range 0.015≤c≤8 mM were complemented by fluorescence correlation spectroscopy (FCS) measurements of the DNA polyion diffusion coefficient D(p)(c). We observed a crossover in the normalized conductivity σ(c)/c that nearly halved across the c=0.05-1 mM range, while D(p)(c) remained rather constant, as we established by FCS. Analyzing these data we extracted θ(c)=0.30-0.45, and taking the Manning asymmetry field effect on polyelectrolyte conductivity into account we got θ(c)=0.40-0.60. We relate the θ(c) variation to gradual DNA denaturation occurring, in the very low salt environment, with the decrease in DNA concentration itself. The extremes of the experimental θ(c) range occur toward the highest, above 1 mM, and the lowest, below 0.05 mM, DNA concentrations and correspond to the theoretical θ values for dsDNA and ssDNA, respectively. Therefore, we confirmed Manning condensation and conductivity models to be valuable in description of dilute solutions of rodlike polyions.

Cytotoxicity of gold nanoparticles prepared by ultrasonic spray pyrolysis

The aim of this work was to study the cytotoxicity of different fractions of gold nanoparticles prepared by ultrasonic spray pyrolysis from gold scrap. The target cells were rat thymocytes, as a type of nonproliferating cells, and L929 mouse fibroblasts, as a type of continuous proliferating cells. Fractions 1 and 2, composed of pure gold nanoparticles, as determined by scanning electron microscopy with a combination of energy dispersive X-ray analysis, were nontoxic for thymocytes, but reduced moderately the proliferative activity of L929 cells. The inhibitory effect of fraction 2, containing particles smaller in size than fraction 1, was stronger. Fraction 3, composed of Au and up to 3% Cu was noncytotoxic for thymocytes, but was cytotoxic for L929 cells. Fraction 4, composed of Au and Ag nanoparticles, and fraction 5, composed of Au together with Cu, Ni, Zn, Fe, and In were cytotoxic for both thymocytes and L929 cells. These results suggest that USP enables the synthesis of pure gold nanoparticles with controlled size, even from gold scrap. However, microstructural analyses and biocompatibility testing are necessary for their proper selection from more cytotoxic gold nanoparticles, contaminated with other elements of gold alloys.

Structure and dynamics of hyaluronic acid semidilute solutions: a dielectric spectroscopy study

Dielectric spectroscopy is used to investigate fundamental length scales describing the structure of hyaluronic acid sodium salt (Na-HA) semidilute aqueous solutions. In salt-free regime, the length scale of the relaxation mode detected in MHz range scales with HA concentration as c(HA)(-0.5) and corresponds to the de Gennes-Pfeuty-Dobrynin correlation length of polyelectrolytes in semidilute solution. The same scaling was observed for the case of long, genomic DNA. Conversely, the length scale of the mode detected in kilohertz range also varies with HA concentration as c(HA)(-0.5) which differs from the case of DNA (c(DNA)(-0.25)). The observed behavior suggests that the relaxation in the kilohertz range reveals the de Gennes-Dobrynin renormalized Debye screening length, and not the average size of the chain, as the pertinent length scale. Similarly, with increasing added salt the electrostatic contribution to the HA persistence length is observed to scale as the Debye length, contrary to scaling pertinent to the Odijk-Skolnick-Fixman electrostatic persistence length observed in the case of DNA. We argue that the observed features of the kilohertz range relaxation are due to much weaker electrostatic interactions that lead to the absence of Manning condensation as well as a rather high flexibility of HA as compared to DNA.

QSAR analysis of antitumor active amides and quinolones from thiophene series

QSAR models for predicting antitumor activity of heterocyclic amides and quinolones from benzo[b]thiophene-, thieno[3,2-b]thiophene- and thieno[2,3-b], thiophene series against MiaPaCa-2 and MCF-7 cells were built. Complete dataset consisted of 59 compounds and several QSAR models with different predictive ability were derived. Beside standard approaches for building QSAR models, the approach based on a small dataset of 10 compounds selected regarding the results of principal component analysis was tested. The latter approach was shown as successful and can be useful for planning future experiments in order to speed up and simplify the search for new drug candidates. Based on the derived QSAR models, the most important properties for compound's antitumor activity against MiaPaCa-2 and MCF-7 cells were identified. Volume, sum of the hydrophobic surfaces and presence of the group that can be easily ionized in the pH range from 4 to 9, were found to be highly important for successful antitumor activity of the examined heterocyclic amides and quinolones. New compounds, with potentially higher biological activity against MiaPaCa-2 and MCF-7 cells, were proposed. Their activities were predicted using the derived QSAR models and the proposed compounds were shown as promising antitumor candidates.

Collective excitations in the charge-ordered phase of α-(BEDT-TTF)2I3

The charge response of a charge-ordered state in the organic conductor α-(BEDT-TTF)2I3 is characterized by dc resistivity, dielectric and optical spectroscopy in different crystallographic directions within the two-dimensional conduction layer. Two dielectric modes are detected. The large mode is related to the phasonlike excitation of the 2k(F) bond-charge density wave which forms in the ab plane. The small dielectric mode is associated with the motion of domain-wall pairs along the a and b axes between two types of domains which are created due to inversion symmetry breaking.

The Response of Macrophages to a Cu-Al-Ni Shape Memory Alloy

Cu—Al—Ni shape memory alloys (SMAs) have been investigated as materials for medical devices, but little is known about their biocompatibility. The aim of this work was to study the response of rat peritoneal macrophages (PMØ) to a Cu—Al—Ni SMA in vitro, by measuring the functional activity of mitochondria, necrosis, apoptosis, and production of proinflammatory cytokines. Rapidly solidified (RS) thin ribbons were used for the tests. The control alloy was a permanent mold casting of the same composition, but without the shape memory effect. Our results showed that the control alloy was severely cytotoxic, whereas RS ribbons induced neither necrosis nor apoptosis of PMØ. These findings correlated with the data that RS ribbons are significantly more resistant to corrosion compared to the control alloy, as judged by the lesser release of Cu and Ni in the conditioning medium. However, the ribbons generated intracellular reactive oxygen species and upregulated the production of IL-6 by PMØ. These effects were almost completely abolished by conditioning the RS ribbons for 5 weeks. In conclusion, RS significantly improves the corrosion stability and biocompatibility of Cu—Al—Ni SMA. The biocompatibility of this functional material could be additionally enhanced by conditioning the ribbons in cell culture medium.

How to prevent lateral thermal damage to tissue using the harmonic scalpel: experimental study on pig small intestine and abdominal wall

INTRODUCTION

When using a harmonic scalpel, the lower amount of energy that is transduced to the tissue reduces the chance of lateral thermal damage.

METHODS

Pigs (weight: 40 kg) were used as the experimental model. After anesthesia, tissue was coagulated using different application regimens for each group. The width of tissue necrosis was measured from the point of incision by the harmonic scalpel.

RESULTS

The pig abdominal tissues suffered mean thermal damage of 0.0825 (output power 3) and 0.2969 mm (output power 5) when used for 5 s; at 10 s these values were 0.3850 and 0.4793 mm, respectively. In a third experimental condition, with 10 s of application broken down into 2 parts of 5 s with a 5-second pause in-between, these values were 0.1876 and 0.2013 mm, respectively. The small intestine tissues suffered mean thermal damage of 0.1302 (output power 3) and 0.1771 mm (output power 5) at a duration of 5 s. After 10 s of application, these values changed to 0.2655 (output power 3) and 0.2983 mm (output power 5). In the third condition (activity for 5 s, pause for 5 s, activity for 5 s), they were 0.2011 and 0.2258 mm, respectively.

CONCLUSION

Coagulation necrosis is bigger if the usage is continuous rather than if it is disconnected/reconnected.

[Rare case of quadricuspid aortic valve]

Quadricuspid aortic valve is rare congenital anomaly. There are only 197 cases published in literature so far. That includes clinical and autopsy reports. This congenital anomaly occurs more often in pulmonary valve but function stays normal in 10 of lies. On the other side, in aortic position valve is malfunctioning in 50% of cases. Valve regurgitation is more likely to occur than stenosis In this kind of malformation, valves are prone to early dysfunction and endocarditis due to different valve architecture and unequal distribution of mechanical stress along valve cusps. Aortic valve replacement is indicated in younger population of these patients. This is a case report of rare congenital anomaly of big blood vessels--aortic valve with four cusps. This anomaly produced significant aortic regurgitation so this patient was indicated for aortic valve replacement.

Optimisation of an extraction procedure and chemical characterisation of Croatian propolis tinctures

Three spectrophotometric methods for the quantitative determination of different flavonoid groups and total phenolics in Croatian propolis samples were optimised and validated. The assay based on the formation of aluminium chloride complex (with galangin as a standard) was applied to the quantification of flavones and flavonols, while the 2,4-dinitrophenylhydrazine method (with pinocembrine as a reference) was used for the quantification of flavanones. Total phenolic content was measured by the Folin-Ciocalteau method using reference solution of caffeic acid:galangin:pinocembrine (1:1:1). Through analytical validation, the most suitable extraction conditions (with respect to time, temperature and concentration of extraction solvent) were determined, and final conditions for the extraction were established (80% ethanol, 1 h at the room temperature). The appropriate ratio between the mass of raw propolis and the extraction solvent volume was also established. By the application of the optimised method of extraction, 10 propolis tinctures were prepared and subjected to the analysis of general pharmacopoeial parameters, which are fundamental for the creation of quality specification (relative density, dry residue of extract, content of ethanol, methanol and 2-propanol). Additionally, the content of waxes as the main inactive constituents was determined in order to observe the level of their migration from crude propolis to the prepared tinctures.

[Chondrofibrosis of adolescent hip]

Authors present 420 hips with slipped capital epiphysis treated in the IOHB "Banjica", during the period between 1970 and 2005. Research includes the analysis of incidence, diagnostics and causes which contribute to the genesis of hip chondrofibrosis. Risk factors are shown, as well as the approach to eliminate them. 39 hips in which this complication occured were individually analyzed. Every hip was separately studied with intent to determine the cause of the condition's genesis, it's evolution, treatment and it's final functionality result. Synovia biopsy was performed in 7 cases, as well as the biopsy of the capsule, articular hyaline cartilage and subchondral bone of the femoral head, which enabled detailed description of both microscopic and macroscopic changes that follow this condition. Regardless of still hypothetical comprehension of the inception of chondrofibrosis, authors clearly state all the risky procedures during treatment that can contribute to the development of chondrofibrosis. The importance of early diagnostics and well-timed treatment are highlighted in this article, for they are crucial. Results of treated hip chondrofibrosis presented here give hope for the destiny of the ill joint, which was considered highly uncertain for a long time.

[Effect of resection of the lateral retinaculum of the knee in surgical treatment of symptomatic patello-femoral incongruency]

Biomechanical malfunction of the knee extensor mechanism in the patello femoral joint is regarded as patella malalignment but major patients complaints are anterior knee pain and patellar slipping. Lateral retinacular release is one of the basic surgical procedures in the treatment of patellar malalignment. The aim of the study was to estimate the achievements of the lateral retinacular release in solving particular biomechanical disorders of the patello femoral joint, as well as individual patients complaints. Evaluation of objective parameters x-ray and clinical findings before and after the operation, shows statistically highly significant difference, thus confirming implementation of the fore mentioned surgical procedure. Despite the fact that anterior knee pain subsided postoperatively in the number of patients, statistically significant values, comparing to the preoperative findings, could not be obtained. Incidence of the patellar slipping has shown statistically significant reduction two years following the surgery. Achieving proper biomechanical alignment of the patello femoral joint is obviously not sufficient to provide relief of subjective complaints, especially concerning anterior knee pain, although considerable improvements were registered in the number of patients.

Dielectric relaxation of DNA aqueous solutions

We report on a detailed characterization of complex dielectric response of Na-DNA aqueous solutions by means of low-frequency dielectric spectroscopy (40 Hz-110 MHz). Results reveal two broad relaxation modes of strength 20<Deltaepsilon(LF)<100 and 5<Deltaepsilon(HF)<20, centered at 0.5 kHz<nu(LF)<70 kHz and 0.1 MHz<nu(HF)<15 MHz. The characteristic length scale of the low-frequency (LF) process, 50<L(LF)<750 nm, scales with DNA concentration as c(DNA)(-0.29+/-0.04) and is independent of the ionic strength in the low added salt regime. Conversely, the measured length scale of the LF process does not vary with DNA concentration but depends on the ionic strength of the added salt as I(s)(-1) in the high added salt regime. On the other hand, the characteristic length scale of the high-frequency (HF) process, 3<L(HF)<50 nm, varies with DNA concentration as c(DNA)(-0.5) for intermediate and large DNA concentrations. At low DNA concentrations and in the low added salt limit the characteristic length scale of the HF process scales as c(DNA)(-0.33). We put these results in perspective regarding the integrity of the double stranded form of DNA at low salt conditions as well as regarding the role of different types of counterions in different regimes of dielectric dispersion. We argue that the free DNA counterions are primarily active in the HF relaxation, while the condensed counterions play a role only in the LF relaxation. We also suggest theoretical interpretations for all these length scales in the whole regime of DNA and salt concentrations and discuss their ramifications and limitations.

[Ilizarov reconstruction of the distal radius after resection of a giant-cell tumor: a case report]

We present a case of Ilizarov reconstruction after en bloc resection of the distal radius. An 8-cm resection was required to remove a giant-cell tumor. Reconstruction was based on the ascension technique using an Ilizarov external fixator after corticotomy of the proximal fragment of the radius. Satisfactory reconstruction with formation of a neoarticulation between the radius and the carpus was achieved. Satisfactory wrist function was achieved and the patient was recurrence free at five years. The arguments leading to this therapeutic option are discussed.