Fe-Cr-Nb-B Ferrofluid for Biomedical Applications

A ferrofluid based on Fe67.2Cr12.5Nb0.3B20 magnetic particles with a low Curie temperature was prepared. The particles, most of which had dimensions under 60 nm, were dispersed in a calcium gluconate solution, leading to a stable ferrofluid. The obtained ferrofluid had a magnetization of 0.04 to 0.17 emu/cm3, depending on the particles' concentration, and a viscosity that increased nonlinearly with the applied magnetic field. The ferrofluid appeared to be biocompatible, as it showed low cytotoxicity, even at high concentrations and for long intervals of co-incubation with human cells, demonstrating a good potential to be used for cancer therapies through magnetic hyperthermia as well as magneto-mechanical actuation.

Nonlinear Dynamics of Spinning Bosonic Stars: Formation and Stability

We perform numerical evolutions of the fully nonlinear Einstein (complex, massive) Klein-Gordon and Einstein (complex) Proca systems, to assess the formation and stability of spinning bosonic stars. In the scalar (vector) case these are known as boson (Proca) stars. Firstly, we consider the formation scenario. Starting with constraint-obeying initial data, describing a dilute, axisymmetric cloud of spinning scalar or Proca field, gravitational collapse toward a spinning star occurs, via gravitational cooling. In the scalar case the formation is transient, even for a nonperturbed initial cloud; a nonaxisymmetric instability always develops ejecting all the angular momentum from the scalar star. In the Proca case, by contrast, no instability is observed and the evolutions are compatible with the formation of a spinning Proca star. Secondly, we address the stability of an existing star, a stationary solution of the field equations. In the scalar case, a nonaxisymmetric perturbation develops, collapsing the star to a spinning black hole. No such instability is found in the Proca case, where the star survives large amplitude perturbations; moreover, some excited Proca stars decay to, and remain as, fundamental states. Our analysis suggests bosonic stars have different stability properties in the scalar (vector) case, which we tentatively relate to its toroidal (spheroidal) morphology. A parallelism with instabilities of spinning fluid stars is briefly discussed.

Human adipose-derived stem cells loaded with drug-coated magnetic nanoparticles for in-vitro tumor cells targeting

Magnetic nanoparticles (MNPs) functionalized with different therapeutics delivered by mesenchymal stem cells represent a promising approach to improve the typical drug delivery methods. This innovative method, based on the "Trojan horse" principle, faces however important challenges related to the viability of the MNPs-loaded cells and drug stability. In the present study we report about an in vitro model of adipose-derived stem cells (ADSCs) loaded with palmitate-coated MNPs (MNPsPA) as antitumor drug carriers targeting a 3D tissue-like osteosarcoma cells. Cell viability, MNPsPA-drug loading capacity, cell speed, drug release rate, magnetization and zeta potential were determined and analysed. The results revealed that ADSCs loaded with MNPsPA-drug complexes retained their viability at relatively high drug concentrations (up to 1.22 pg antitumor drug/cell for 100% cell viability) and displayed higher speed compared to the targeted tumor cells in vitro. The magnetization of the sterilized MNPsPA complexes was 67 emu/g within a magnetic field corresponding to induction values of clinical MRI devices. ADSCs payload was around 9 pg magnetic material/cell, with an uptake rate of 6.25 fg magnetic material/min/cell. The presented model is a proof-of-concept platform for stem cells-mediated MNPs-drug delivery to solid tumors that could be further correlated with MRI tracking and magnetic hyperthermia for theranostic applications.

Fe-Cr-Nb-B ferromagnetic particles with shape anisotropy for cancer cell destruction by magneto-mechanical actuation

We introduce a new type of magnetic particles (MPs) prepared by wet milling of superferromagnetic Fe-Cr-Nb-B precursor glassy ribbons for cancer treatment by magneto-mechanical actuation in low magnetic fields (1 ÷ 20 Oe). The rectangular shapes of MPs and the superferromagnetism of the glassy alloys of which are made the MPs induce important magnetic shape anisotropies which, in association with a large saturation magnetization, generate an improved torque in a rotating magnetic field, producing important damages on the cellular viability of MG-63 human osteosarcoma (HOS) cells. The specific parameters such as MPs concentration, frequency and intensity of the applied magnetic field, or the time of exposure have a strong influence on the cancer cells viability. The specific behavior of the Fe-Cr-Nb-B MPs offers them destructive effect even in low magnetic fields such as 10 Oe, and this characteristic allows the use of coils systems which provide large experimental spaces. The novel MPs are used for the magneto-mechanical actuation alone or in association with hyperthermia, but also can be transported to the tumor sites by means of stem cells carriers.

Human Adipose Derived Stem Cells and Osteoblasts Interaction with Fe-Cr-Nb-B Magnetic Nanoparticles

The use of materials at nanoscale is currently of increasing interest for life sciences and medicine. Magnetic nanoparticles (MNPs) are under scrutiny for a large array of applications in nanomedicine as diagnostic and therapeutic tools. Proprietary Fe-Cr-Nb-B MNPs display heating properties that recommends them as potent agents for delivery of local hyperthermia for the treatment of solid tumours. Stem cell mediated delivery represents a safe and accurate modality to target remote or metastatic tumour sites. In this study we investigated the interaction of Fe-Cr-Nb-B nanoparticles with human adipose derived mesenchymal stem cells and human primary osteoblasts. We found that: (a) bare and chitosan coated Fe-Cr-Nb-B are internalized by both cell types, (b) they can be detected up to 28 days inside the cells without signs of membrane disruption and (c) they do not display in vitro toxicity. MNPs are uploaded by cells in a time dependent manner with maximum uptake after 7-8 days cell-particle incubation. Particle internalization do not interfere with proliferative and differentiation potential (osteogenesis and adipogenesis) demonstrating an unaltered cellular phenotype. Further investigation of the potential effect of MNPs internalization on cytoskeleton dynamics and in inducing oxidative stress will be required as it is of interest for predicting cell migration and survival after transplantation. Present results are encouraging for designing a stemcell mediated delivery of Fe-Cr-Nb-B magnetic nanoparticles to solid tumour sites for hyperthermia applications.

Comparative effects of magnetic and water-based hyperthermia treatments on human osteosarcoma cells

INTRODUCTION

Hyperthermia (HT) based on magnetic nanoparticles (MNPs) represents a promising approach to induce the apoptosis/necrosis of tumor cells through the heat generated by MNPs submitted to alternating magnetic fields. However, the effects of temperature distribution on the cancer cells' viability as well as heat resistance of various tumor cell types warrant further investigation.

METHODS

In this work, the effects induced by magnetic hyperthermia (MHT) and conventional water-based hyperthermia (WHT) on the viability of human osteosarcoma cells at different temperatures (37°C-47°C) was comparatively investigated. Fe-Cr-Nb-B magnetic nanoparticles were submitted either to alternating magnetic fields or to infrared radiation generated by a water-heated incubator.

RESULTS

In terms of cell viability, significant differences could be observed after applying the two HT treatment methods. At about equal equilibrium temperatures, MHT was on average 16% more efficient in inducing cytotoxicity effects compared to WHT, as assessed by MTT cytotoxicity assay.

CONCLUSION

We propose the phenomena can be explained by the significantly higher cytotoxic effects initiated during MHT treatment in the vicinity of the heat-generating MNPs compared to the effects triggered by the homogeneously distributed temperature during WHT. These in vitro results confirm other previous findings regarding the superior efficiency of MHT over WHT and explain the cytotoxicity differences observed between the two antitumor HT methods.

Combinatorial approach for improving the outcome of angiogenic therapy in ischemic tissues

Two major populations of endothelial progenitor cells (EPC), namely endothelial colony forming cells (ECFC, or late outgrowth EPC) and circulating angiogenic cells (CAC, or early outgrowth EPC) have been reported to play important roles in vasculogenesis in numerous pathological conditions. However, the poor retention of cells into the ischemic tissue and neovessel fragility are two major flaws that need to be overcome for successful angiogenic therapy. The objective of this study was to explore and exploit the functional properties of EPC populations in order to increase the effectiveness of post-ischemic cell therapy. The results indicate different, still complementary, effects of the two EPC populations on adherence and proliferation of vascular endothelial cells. Matrigel plug assay and mouse hind limb ischemia model showed that concomitant administration of CAC-secreted factors and ECFC resulted in three-fold increase in local cell retention and improved muscle perfusion, vessel maturation and hind limb regeneration, in comparison to either treatment alone. By concluding, factors secreted by CAC co-administered at the time of ECFC transplantation improve tissue regeneration and vascular repair through stabilization of newly-derived blood vessels.

miR-193 expression differentiates telocytes from other stromal cells

Telocytes (TCs) are a particular type of interstitial (stromal) cells defined by very long, moniliform telopodes. Their tissue location, between blood vessels and other cells such as cardiomyocytes (CMC) and neurons, suggests a role in intercellular signalling. In order to define a microRNA (miR) signature in cardiac TCs, we have found that miR-193 is differentially expressed between TCs and other interstitial cells. Because miR-193 regulates c-kit, our data support the previous finding that TCs express c-kit in certain circumstances. In addition, the miRs which are specific to CMC and other muscle cells (e.g. miR-133a, miR-208a) are absent in TCs. Overall the data reinforce the view that TCs are a particular type of interstitial (mesenchymal) cells.

Neuroendocrine transdifferentiation of prostate carcinoma cells and its prognostic significance

Neuroendocrine (NE) cells are a distinct epithelial cell compartment of the normal human prostate gland. Their phenotype and range of endocrine secretion products are similar, but not identical to those of NE-like cells from prostate carcinoma. Neuroendocrine differentiation (NED) is a feature commonly seen in prostate carcinoma and a number of studies pointed out that its extent is associated to hormone therapy refractory and aggressive disease. However, less information is available on the significance of NED in organ-confined prostate cancer, although identification of early predictors of aggressive disease would obviously allow for more adequate therapy. We review here recent advances in understanding the differentiation pathways of normal and malignant neuroendocrine cells as well as current information regarding the prognostic and therapeutic implication of NED assessment.

Neuroendocrine differentiation in prostate adenocarcinoma biopsies and its correlation to histological grading

Prostate adenocarcinoma is frequently diagnosed on needle biopsies in early, organ-confined stages. New prognostic factors would help identifying at this stage patients at risk for unfavorable evolution, that would benefit from alternate therapy. This study aims to find correlations between the extent of neurocrine differentiation (NED), a feature commonly seen in prostate carcinoma, and known factors of disease evolution such as histological grade, malignant cell proliferation and serum PSA levels. Immunohistochemistry for choromogranin A and neuron-specific enaolase (NSE) was used to calculate expression scores in order to asses the extent of NED in prostate biopsies. Tumour proliferative activity was estimated by calculating percentages of Ki-67 immunoreactive cell nuclei. Results show that the presence of numerous clusters of chromogranin A positive cells is a feature that differentiate tumours with Gleason score 9 from those with a score of 6. Also, the same extended neuroendocrine differentiation is associated with high tumour proliferative activity. Multinomial regression analysis showed that high Ki indices, serum PSA values and NSE scores are predictive for moderately and poorly differentiated prostatic adenocarcinoma.

Monte Carlo simulation and patient dosimetry for a kilovoltage cone-beam CT unit

PURPOSE

The purpose of this work is to characterize the x-ray volume imager (XVI), the cone-beam computed tomography (CBCT) unit mounted on the Elekta Synergy linac, with F1 bowtie filter and to calculate the three-dimensional dose delivered to patients using volumetric acquisition.

METHODS

The XVI is modeled in detail using a new Monte Carlo (MC) code, BEAMPP, under development at the National Research Council Canada. In this investigation, a new component module is developed to accurately model the unit's bowtie filter used in conjunction with the available beam collimators at the clinical energy of 120 kV. The modeling is compared against percentage depth dose (PDD) and profile measurements. Kilovoltage radiation beams' phase space files are also analyzed. The authors also describe a method for the absolute dose calibration of the MC model of the CBCT unit when used in a clinical volumetric acquisition mode. Finally, they calculate three-dimensional patient dose from CBCT image acquisition in three clinical cases of interest: Pelvis, lung, and head and neck.

RESULTS

The agreement between measurement and MC is shown to be very good: Within +/- 2% for the PDD and within +/- 3.5% inside the radiation field for all the collimators with the F1 bowtie filter. A full account of the absolute calibration method is given and dose calculation is validated against ion chamber measurements in different locations of a plastic phantom. Calculations and experiments agree within +/- 2% or better in both at the center and the periphery of the phantom, with worst agreement of 4.5% at the surface of the phantom and for one specific combination of collimator and filter. Patient dose from CBCT scan reveals that dose to tissue is between 2 and 2.5 cGy for a pelvis or a lung full acquisition. For H&N dose to tissue is 5 cGy, with the unit presets used in this work. Dose to bony structures can be two to three times higher than dose to tissue.

CONCLUSIONS

The XVI CBCT unit has been fully modeled including the F1 bowtie filter. Absolute dose distribution from the unit has been successfully validated. Full MC patient dose calculation has shown that the three-dimensional dose distribution from CBCT is complex. Patient dose from CBCT exposure cannot be completely accounted for by using a numerical factor as an estimate of the dose at the center of the body. Furthermore, additional dose to bone should be taken into account when adopting any IGRT strategy and weighed vs the unquestionable benefits of the technique in order to optimize treatment. Full three-dimensional dose calculation is recommended if patient dose from CBCT is to be integrated in any adaptive planning strategy.

[Post-cesarean acute aortic dissection in a Marfan syndrome patient]

Marfan syndrome is an uncommon condition in pregnancy. We present the case of 37 years old gravida 1, para 1 with Marfan syndrome. She delivered at term by cesarean section, a healthy male infant weighing 3500 grams with Apgar's of 9. During the postoperative period she developed aortic dissection and was referred to the Cardiovascular Surgery Department. We described such a case and the difficult decisions that we faced.

[Ultrasound of cervix uteri transvaginal in preterm birth]

Premature birth is a social problem due to its implications in the natal mortality and morbidity. This is the reason why it is necessary to establish new methods which could identify pregnant women with high risk of premature birth. Besides the measurable biochemical factors such as fetal fibronectin and salivary estriol, I1-6 sonography is a simple method highly efficient and of reasonable financial costs among all the sonographic means of observing the cervix uteri. The transvaginal sonography is the "golden standard", permitting the most faithful assessment of the pursued parameters--the length of the cervix, the aspect of the internal os (funneling), the cervix index. The experience gathered up to now shows that all of these investigations have a predictive value which is more negative than positive, but when used together they could lead to an improved result.

Cajal-type cells from human mammary gland stroma: phenotype characteristics in cell culture

We report here the in vitro isolation of Cajal-like interstitial cells from human inactive mammary-gland stroma. Primary cell cultures examined in phase-contrast microscopy or after vital methylene-blue staining revealed a cell population with characteristic morphological phenotype: fusiform, triangular or polygonal cell body and the corresponding (very) long, slender, moniliform cytoplasmic processes. Giemsa staining pointed out the typical knobbed aspect of cell prolongations. Immunofluorescence (IF) showed, like in situ immunohistochemistry, that Cajal-type cells in vitro (primary cultures), expressed c-kit/CD117 and vimentin. In conclusion, the images presented here reinforce our previous hypothesis that human mammary glands have a distinct population of Cajal-like cells in non-epithelial tissue compartments.

The connective connection: interstitial cells of Cajal (ICC) and ICC-like cells establish synapses with immunoreactive cells. Electron microscope study in situ

We present transmission electron microscope (TEM) evidence that ICC and ICC-like cells frequently establish close contacts (synapses) with several types of immunoreactive cells (IRC): lymphocytes, plasma cells, eosinophils, basophils, macrophages and mast cells. Such synapses were found in various organs: human mammary gland and myometrium, as well as rat stomach, gut, bladder and uterus. Specimens were observed by conventional TEM on ultrathin sections. Based on morphometric analyses and computer-aided 3-D reconstructions from serial sections, we propose an operational definition of ICC-IRC synapses: cell-to-cell close contacts where the two cells are separated by only approximately 15 nm, equivalent to twice the plasmalemmal thickness. Two types of such synapses were found: (i) uniform ('plain') synapses (PS). close contact extending for >200 nm, and (ii) multi-contact ('kiss and run') synapses (MS)--with multiple, focal, close-contact points alternating with regions of wider intermembrane distance. For instance, a typical PS between a rat bladder ICC-like cell and an eosinophil was 2.48 microm long and 11+/-4 nm wide. By contrast, a MS synapse in rat myometrium (between an ICC-like cell and an eosinophil) was 8.64 microm long and had 13 contact points. The synaptic cleft measured 15+/-8 nm at contact points and approximately 100 nm or more in wider areas. These synapses are different from gap junctions usually seen between ICC and between ICC and smooth muscle cells. We previously proposed that ICC-like cells might represent stromal progenitor cells, participate in juxtacrine/paracrine signaling and play a role in immune surveillance. The nanoscopic distances between the two contiguous membranes suggest a juxtacrine cell-to-cell signaling (chemical synapse), via juxtacrinins, a specific case of phenomenins. However, the (micro)vesicles found in the synaptic cleft may correspond to an exosome-based mechanism.

C-kit immunopositive interstitial cells (Cajal-type) in human myometrium

Previous reports describing Cajal-like interstitial cells in human uterus are contradictory in terms of c-kit immunoreactivity: either negative (but vimentin-positive) in pregnant myometrium, or positive, presumably in the endometrium. The aim of this study was to verify the existence of human myometrial Cajal-like interstitial cells (m-CLIC). Six different, complementary approaches were used: 1) methylene-blue supravital staining of tissue samples (cryosections), 2) methylene blue and Janus green B vital staining (m-CLIC and mitochondrial markers, respectively), and 3) extracellular single-unit electrophysiological recordings in cell cultures, 4) non-conventional light microscopy on glutaraldehyde/osmium fixed, Epon-embedded semi-thin sections (less than 1 microm) stained with toluidine blue (TSM), 5) transmission electron microscopy (TEM), and 6) immunofluorescence (IF). We found m-CLIC in myometrial cryosections and in cell cultures. In vitro, m-CLIC represented approximately 7% of the total cell number. m-CLIC had 2-3 characteristic processes which were very long (approximately 60 microm), very thin (< or =0.5 microm) and moniliform. The dilated portions of processes usually accommodated mitochondria. In vitro, m-CLIC exhibited spontaneous electrical activity (62.4+/-7.22 mV membrane potentials, short duration: 1.197+/-0.04 ms). Moreover, m-CLIC fulfilled the usual TEM criteria, the so-called 'gold' or 'platinum' standards (e.g. the presence of discontinuous basal lamina, caveolae, endoplasmic reticulum, and close contacts between each other, with myocytes, nerve fibers and/or capillaries etc.). IF showed that m-CLIC express CD117/c-kit, sometimes associated with CD34, with vimentin along their processes. In conclusion, we describe myometrial Cajal-like interstitial cells that have affinity for methylene blue and Janus green B vital dyes, fulfill (all) TEM criteria, express CD117/c-kit and have spontaneous electric activity.

Novel type of interstitial cell (Cajal-like) in human fallopian tube

We describe here--presumably for the first time--a Cajal-like type of tubal interstitial cells (t-ICC), resembling the archetypal enteric ICC. t-ICC were demonstrated in situ and in vitro on fresh preparations (tissue cryosections and primary cell cultures) using methylene-blue, crystal-violet, Janus-Green B or MitoTracker-Green FM Probe vital stainings. Also, t-ICC were identified in fixed specimens by light microscopy (methylene-blue, Giemsa, trichrome stainings, Gomori silver-impregnation) or transmission electron microscopy (TEM). The positive diagnosis of t-ICC was strengthened by immunohistochemistry (IHC; CD117/c-kit+ and other 14 antigens) and immunofluorescence (IF; CD117/c-kit+ and other 7 antigens). The spatial density of t-ICC (ampullar-segment cryosections) was 100-150 cells/mm2. Non-conventional light microscopy (NCLM) of Epon semithin-sections revealed a network-like distribution of t-ICC in lamina propria and smooth muscle meshwork. t-ICC appeared located beneath of epithelium, in a 10-15 microm thick 'belt', where 18+/-2% of cells were t-ICC. In the whole lamina propria, t-ICC were about 9%, and in muscularis approximately 7%. In toto, t-ICC represent ~8% of subepithelial cells, as counted by NCLM. In vitro, t-ICC were 9.9+/-0.9% of total cell population. TEM showed that the diagnostic 'gold standard' (Huizinga et al., 1997) is fulfilled by 'our' t-ICC. However, we suggest a 'platinum standard', adding a new defining criterion- characteristic cytoplasmic processes (number: 1-5; length: tens of microm; thickness: < or =0.5 microm; aspect: moniliform; branching: dichotomous; organization: network, labyrinthic-system). Quantitatively, the ultrastructural architecture of t-ICC is: nucleus, 23.6+/-3.2% of cell volume, with heterochromatin 49.1+/-3.8%; mitochondria, 4.8+/-1.7%; rough and smooth endoplasmic-reticulum (1.1+/-0.6%, 1.0+/-0.2%, respectively); caveolae, 3.4+/-0.5%. We found more caveolae on the surface of cell processes versus cell body, as confirmed by IF for caveolins. Occasionally, the so-called 'Ca2+-release units' (subplasmalemmal close associations of caveolae+endoplasmic reticulum+mitochondria) were detected in the dilations of cell processes. Electrophysiological single unit recordings of t-ICC in primary cultures indicated sustained spontaneous electrical activity (amplitude of membrane potentials: 57.26+/-6.56 mV). Besides the CD117/c-kit marker, t-ICC expressed variously CD34, caveolins 1&2, alpha-SMA, S-100, vimentin, nestin, desmin, NK-1. t-ICC were negative for: CD68, CD1a, CD62P, NSE, GFAP, chromogranin-A, PGP9.5, but IHC showed the possible existence of (neuro)endocrine cells in tubal interstitium. We call them 'JF cells'. In conclusion, the identification of t-ICC might open the door for understanding some tubal functions, e.g. pace-making/peristaltism, secretion (auto-, juxta- and/or paracrine), regulation of neurotransmission (nitrergic/purinergic) and intercellular signaling, via the very long processes. Furthermore, t-ICC might even be uncommitted bipotential progenitor cells.

Early and late effect of infliximab on circulating dendritic cells phenotype in rheumatoid arthritis patients

The aim of this study was to analyze the phenotype of circulating dendritic cells (DCc) in rheumatoid arthritis (RA) patients before and after treatment with infliximab (at 24 h and 6 months) and the correlation between these changes and the clinical response to treatment. Sixteen patients with RA were recruited and clinical status was determined using the Disease Activity Score 28 (DAS28). All patients had active disease (mean DAS28 = 5.96) and were suitable for treatment with infliximab. Samples of peripheral venous blood were obtained before administration of the first dose of infliximab and again at 24 h and 6 months after treatment. DCc populations were analyzed by flow cytometry. At 24 h, there were no differences in the clinical status of the patients. However, we found a decrease in CD11c+ and, to a lesser extent, CD123+ DCc percentages. The expression of CD83, the most important activation marker for DC, was also shown to be decreased 24 h after infliximab therapy. After 6 months of treatment, all patients showed significant clinical improvement (mean DAS28 = 3.64, p < 0.001) and expression of the activation marker on DCc remained low. In conclusion, this study supports the role of tumor necrosis factor (TNF)-alpha blockade in preventing the maturation of DCc and in reducing the expression of their activation markers. Although the clinical response to infliximab was not observed after 24 h, DCc activation was strongly reduced by anti-TNF-alpha therapy. After 6 months of treatment, current data show a less active phenotype of DCc associated with clinical improvement in all patients in the study.

[Expression of stem cell markers on fetal and tumoral human liver cells in primary culture]

Hepatic stem cells can be identified by the expression of putative markers such as CD117 (c-kit), CD90 (Thy-1), CD34, and HLA-DR. We have identified populations expressing these markers in both fetal and tumoral human liver by flow cytometry, using monoclonal antibodies against CD90, CD117, CD34, and HLA-DR. In tumoral liver CD117+/CD90+ cells were found in decreasing number from the neoplastic (2.48 +/- 0.67) and peritumoral region (0.88 +/- 0.12) to the area of para-tumoral (normal) parenchyma (0.13 +/- 0.04). The CD117+/CD34+ cells showed the following distribution: 0.35 +/- 0.05% in the tumoral region, 1.01 +/- 0.23% in the peritumoral region and 0.35 +/- 0.01 in the para-tumoral region. Using the same markers on fetal liver cells we have also identified small populations of CD117+/CD90+ cells (0.28 +/- 0.07%) and CD117+/CD34+ cells (1.13 +/- 0.24%), presumably resident stem cells or hematopoietic stem cells. Immunomagnetic negative separation was then performed on fetal liver cells using monoclonal antibodies against specific markers of hematopoietic lineages such as CD3, 14, 16, 19, 22, and CD56 to eliminate this population. The remaining cells were then incubated with fluorescently labeled monoclonal antibodies against CD90 and CD117 and analyzed using fluorescence microscopy. As expected these markers were expressed on the majority of the selected cells (89.28 +/- 9.56%). Isolation using appropriate markers and initiation of primary cultures is a first step to the therapeutic use of fetal stem cells and for the study of adult liver stem cells involvement in carcinogenesis.

Correlation between the immunophenotypical presentation of dendritic cells and the clinical response to anti-rheumatic treatment in rheumatoid arthritis

BACKGROUND

Dendritic cells (DCs) are potent antigen-presenting cells (APC) that are deeply implicated in the initiation and exacerbation of rheumatoid arthritis (RA). Active RA is associated with an activated DCs population as demonstrated by high expression of adhesion and co-stimulatory molecules.

PURPOSE

To compare the expression of adhesion and co-stimulatory molecules on DCs from synovial tissue (ST) in patients (pts) with RA and the clinical status before and after treatment with disease modifying antirheumatic drugs (DMARDs).

METHODS

Samples of ST were obtained from RA patients at the time of hip or knee replacement or arthroscopy. Clinical status (assessed by the American College of Rheumatology - ACR - core set and the DAS28) and co-stimulatory and adhesion molecules on DCs were evaluated before and after treatment. Immunophenotype of DCs was analyzed by two-color immunofluorescence microscopy.

RESULTS

In patients with active RA we found a highly differentiated subpopulation of DCs that expressed an activated phenotype. After treatment, the expression of adhesion and co-stimulatory molecules on ST DCs was correlated with the ACR and DAS28 clinical response.

CONCLUSION

Clinical outcome and the immunophenotypical presentation of ST DCs after DMARDs treatment are closely correlated in pts with RA. The co-stimulatory activity in the synovium is important in determining the course of the disease and provide new therapeutic targets for immune intervention.

Stem cells (p63(+)) in keratinocyte cultures from human adult skin

Epidermal stem cells (ESC) are responsible for maintaining skin cellular homeostasis, as they give rise to fast-dividing transit amplifying cells committed to terminal differentiation, while retaining their self-renewal capacity. However, no pure ESC cultures are available and no highly specific cytochemical marker was identified. We report here the experimental conditions allowing the selective enrichment in ESC, using cultured adult human keratinocytes. The main step was the selection of cells able to rapidly adhere to human collagen type IV in vitro. Thus, an increased proportion of putative ESC of about 65% was obtained, as demonstrated by p63 expression.

Co-stimulatory and adhesion molecules of dendritic cells in rheumatoid arthritis

Dendritic cells (DCs) in the rheumatoid arthritis (RA) joint mediate the immunopathological process and act as a potent antigen presenting cell. We compared the expression of co-stimulatory and adhesion molecules on DCs in RA patients versus controls with traumatic joint lesions and evaluated the correlation between the immunophenotypical presentation of DCs and the clinical status of the disease. Samples of peripheral venous blood, synovial fluid (SF) and synovial tissue (ST) were obtained from 10 patients with RA at the time of hip or knee replacement and from 9 control patients with knee arthroscopy for traumatic lesions. Clinical status was appreciated using the DAS28 score. Blood, SF and dissociated ST cell populations were separated by centrifugation and analyzed by flow cytometry. Cells phenotypes were identified using three-color flow cytometry analysis for the following receptors HLA-DR, CD80, CD83, CD86, CD11c, CD18, CD54, CD58, CD3, CD4, CD8, CD19, CD20, CD14, CD16, CD56. HLA-DR molecules, co-stimulatory receptors CD80, CD86, CD83 and adhesion molecules CD18, CD11c, CD54, CD58, were analyzed by two-color immunofluorescence microscopy on ST serial sections. In patients with active RA (DAS28>5.1) we found a highly differentiated subpopulation of DCs in the ST and SF that expressed an activated phenotype (HLA-DR, CD86+, CD80+, CD83+, CD11c+, CD54+, CD58+). No differences were found between circulating DCs from RA patients and control patients. Our data suggest an interrelationship between clinical outcome and the immunophenotypical presentation of DCs. Clinical active RA (DAS28>5.1) is associated with high incidence of activated DCs population in the ST and SF as demonstrated by expression of adhesion and co-stimulatory molecules.

Apoptosis in the immune system: 1. Fas-induced apoptosis in monocytes-derived human dendritic cells

Dendritic cells (DC) are cells of the hematopoietic system specialized in capturing antigens and initiating T cell-mediated immune responses. We show here that human DC generated from adherent peripheral blood mononuclear cells (PBMC) after in vitro stimulation with granulocyte macrophage colony stimulating factor (GM-CSF) and interleukin-4 (IL-4) express Fas antigen (APO-1, CD95) and can undergo apoptosis upon triggering of Fas by monoclonal antibodies. Immature monocytes-derived dendritic cells (MDDC) upregulate CD86 and HLA-DR expression and develop dendrites and veiled processes. Flow cytometry analysis revealed CD95 expression in approx. 40% of these MDDC and incubation with anti-CD95 mAb (0.5 microg/ml) induced apoptosis when compared to untreated controls. The extent of apoptosis induced by the agonist anti-Fas antibody strongly related to the percentage of cells expressing CD 95. Upon tumor necrosis factor alpha (TNF-alpha) additional stimulation, MDDC assumed a characteristic mature dendritic cells morphology showing prolonged veils, CD83 expression, and high levels of HLA-DR. These cells have downregulated their Fas receptors (to approx. 20%) and undergo apoptosis to a lesser extent when treated with anti-CD 95, as demonstrated by the hardly noticeable effect of this antibody on the viability of cultured cells as compared to controls. Thus, upon TNF-alpha induced maturation, MDDC became resistant to Fas-induced apoptosis. The apoptotic episodes surrounding the earlier stage of DC differentiation appeared to be mediated by Fas. In contrast, a Fas independent pathway is probably responsible for the apoptotic events associated with terminally differentiated DC.

Apoptosis in human embryo development: 3. Fas-induced apoptosis in brain primary cultures

Fas (APO-1/CD95) is an important apoptotic mediator for both immune and nervous systems. In the present study, we have investigated the expression and function of Fas in human embryonic/fetal brain primary cultures from 12 human embryos and fetuses with gestational ages between 5 to 22 weeks. Anti-Fas fluorescent antibody was used for labeling of Fas positive cells and for quantitation of Fas expression in brain cultures. To demonstrate that Fas receptor is functional in human embryonic/fetal brain cells, anti-Human-Fas monoclonal antibody (0.5 microg/ml) was used to induce apoptosis in brain primary cultures. Apoptosis was investigated by flow-cytometry and fluorescent microscopy using TUNEL and annexin V labeling. Fas was found to be expressed in the embryonic/fetal human primary brain cultures, on neuronal and glial cells or their precursors, varying with gestational ages. Cross-linking of Fas induced apoptosis in brain cultures indicating that Fas receptor functions as a death receptor. We also showed that cell death triggered through Fas receptor was caspase dependent, hence it was blocked by a selective caspase-8 inhibitor (IETD-fmk). These results suggest that Fas is involved in neuronal apoptosis in the developing human brain.

Current laboratory assays and in vitro intracellular Th1 and Th2 cytokine synthesis in monitoring antiretroviral therapy of pediatric HIV infection

In 42 HIV-infected children, 8-10 years old, belonging to the category A state of infection, combined antiretroviral therapy (cART) was applied, consisting of AZT, ddC and Saquinavir. At 6 and 12 weeks following the start of cART, the efficacy of treatment was assessed, both by means of current parameters (blood CD4+ cell levels, virus load) and by measuring the intracellular synthesis of some Th1 (interleukin (IL)-2, interferon-gamma) and Th2 (IL-4, IL-10) cytokines, in CD4+ lymphocytes, respectively. Before cART, low values of blood CD4+ cell counts and a mean of about 8000 virus RNA copies ml(-1) of serum were detected, and in addition decreased levels of production of both intracellular Th1 cytokines, associated with increased levels of one of the Th2 cytokines (IL-10), but not of the other (IL-4), were noticed. After cART, earlier improvement of intracellular IL-2, interferon-gamma and IL-10 synthesis in CD4+ cells occurred compared to CD4+ counts and virus load. The usefulness of scoring the rates at which CD4+ lymphocytes are able to synthesize intracellular Th1 or Th2 cytokines, as an additional immune parameter during combined antiretroviral therapy monitoring in pediatric AIDS, is discussed.

Multi-way flow cytometric immune monitoring of antiretroviral therapy in HIV-infected children

In 40 HIV-infected children, 8-10 years old, belonging to the category A state of infection, the following flow-cytometric parameters were scored: percentage levels of different blood lymphocytes; surface expression of some activation and memory markers in CD4+ cells; switch to Th1 or Th2 of in vitro -stimulated CD4+ cell, tested by intracellular production of interleukin-2 or interleukin-4. Each investigation was carried out both before and 3 months after antiretroviral therapy (AZT and ddC). Some post-therapy changes concerning blood lymphocyte percentages were noticed, not only within CD4+ subpopulation, but also within CD8+, HLA-DR+/CD3 (T-activated) and CD16+CD56+ cells, respectively. On the other hand, following antiretroviral treatment, in HIV- originated CD4+ fresh cells, an improvement of pre-therapy increased values of surface activation (CD69, CD25) markers on memory (CD45RO+) cells, as well as of pre-therapy reduced rate of switching to Th1, revealed by intracellular interleukin-2 synthesis, was found. The significance of data obtained in the multi-way immune monitoring of antiretroviral therapy, in pediatric AIDS, as an additional investigation panel, is discussed.

Expression of activation surface markers, interleukin-2 synthesis and apoptosis rate in fresh or cultured lymphocytes from HIV-infected children

In 2 groups of HIV-infected children aged from 7 to 10 years (ARC and AIDS, respectively) the following immune markers: % expression of CD69, CD25, HLA-DR activation surface determinants, IL-2 synthesis, rate of apoptosis were tested in non stimulated, PHA-stimulated or PHA and IL-12-stimulated T cell cultures. In all HIV-originated cells a decrease of CD69 expression and an increase of CD25 and HLA-DR expression were found. A strong correlation could be noticed between the clinical stage of the AIDS infection and the in vitro IL-2 production and the percentages of apoptotic cultured cells. IL-12 supplementation of PHA-stimulated cell samples restored the IL-2 synthesis and reduced the apoptosis rates only in the ARC-group, but not in the AIDS-group. The significance of the present data in the clinical and therapeutic monitoring of HIV infection among low-aged people are discussed.

Immune monitoring of surgical colorectal malignancies through carcinoembryonic antigen and alpha-fetoprotein serum levels, flow-cytometric blood lymphocyte phenotyping and tumor DNA analysis

67 patients with operable colorectal adenocarcinomas were divided into two groups based on criteria referring to DNA flow-cytometric models and the histopathological type and stage of intraoperatively harvested tumor samples: low-aggressive tumor group and highly aggressive tumor group. Two kinds of immunological markers were investigated: humoral (carcinoembryonic antigen and alpha-fetoprotein serum levels were measured by ELISA) and cellular (blood lymphocyte counts of the following subpopulations: CD3+, CD4+, CD8+/CD11b+, CD19+, CD16+/CD56+, HLA-DR+/CD3+, measured by means of flow cytometry). All assays were similarly performed before and 2, 4, 6 and 8 weeks after tumor exeresis. Results seem to reveal a relationship between patients without immunological recovering and a bad postoperative clinical evolution of the highly aggressive colorectal malignant tumors. The significance of multiway immune monitoring of colorectal cancer is discussed.

Pre- and post-therapy blood lymphocyte levels in IgE-negative urticaria, associated with several parasitic or fungal diseases

115 patients with non-immune (IgE-negative) urticaria, related to parasitic (lambliasis, oxyuriasis, ascaridiasis) or fungal (candidiasis) associations were investigated-both before and one month after specific and antihistaminic therapy-concerning different percentage levels of blood lymphocyte sets and subsets, by means of flow cytometry. Before therapy, three kinds of immune deficiency patients were obtained, one in lambliasis and oxyuriasis, the second in ascaridiasis, and the third in candidiasis, respectively. Clinical, biological and immunological recovering after therapy exhibited some differences related to the presumed non-allergic etiology, i.e. better in lambliasis and oxyuriasis and worse in ascaridiasis and candidiasis.

Different patterns of some systemic immunological cell markers in HIV only, and HIV/hepatitis C-infected children

In three groups of children, aged 4-6 years (i.e., human immunodeficiency virus [HIV]-negative controls, HIV-seropositive, and dually HIV/hepatitis C virus (HCV)-seropositive), two types of immunological investigations in blood cells were performed: (a) numerical assays, consisting of flow cytometric measurement of different lymphocyte sets or subsets, as follows: CD3+, CD19+, CD4+, CD16+/CD56+; (b) functional assays, consisting of interleukin-1 (IL-1) levels as well as natural killer (NK)-cell dependent cytotoxicity, in CD14+, or CD16+/CD56+ sorted cells, respectively. Results revealed, in addition to the classic markers (i.e., lower numbers of CD4+ cells and a decreased CD4+/CD8+ ratio in both infected groups of subjects) other findings, as follows: increased numbers of CD8+ cells in dually infected children, accompanied by a lower CD4+/CD8+ ratio, as compared to HIV-infected alone; diminished numbers of CD16+/CD56+ cells in both groups of infected patients were correlated with a lower NK-cell cytotoxicity rate; a reduced capacity for IL-1 synthesis of sorted macrophages both in HIV-only and in HIV/HCV-seropositive subjects, but significantly more marked in dually infected children. The importance of the present data in the immune monitoring of AIDS disease in a pediatric population is discussed.

Growth parameters and rate of expression of some CD markers in sorted and not sorted macrophage cultures

Several parameters of in vitro culturing were investigated for two kinds of human macrophages cell fractions, i.e. sorted by flow cytometry and not sorted, as follows:--growth ability during serial in vitro passages, and--percent rate of CD13, CD14 and CD33 expression at different in vitro passage levels. Results point out the ability of sorted cells to survive to a higher number of serial passages. A dramatical loss of CD13 and especially CD33 markers was noticed during culturing within the not sorted cells, as compared to homologous sorted ones.

Blood amounts and suppressive in vitro activity of CD8+11b(+)-lymphocytes from HIV-infected children, related to hepatitis B or C virus association

In HIV only, as well as in HIV/hepatitis B- and HIV/hepatitis C-infected children (6 to 8 years of age), with moderate altered clinical and immune cell markers, the total amounts of CD8(+)-set and of CD8+11b(+)-subset (T-suppressor) blood lymphocytes, by means of flow cytometry, were determined. On the other hand, within several mixtures of autologous sorted CD3+/CD8+11b(+)-cells, the per cent reduction of HLA-DR+ expression on T-cells, at different effector/responder cell ratios, was appreciated. Significant higher levels of CD8+11b(+)-cells, especially in HIV/hepatitis B virus groups, were found, that correlated with a stronger suppressive activity. The strongest alteration of immune markers, within HIV-seropositive, HBs+, HBe+ patients, was noticed. A possible usefulness of these data in HIV only, and in HIV-associated hepatitis B or C virus contamination, during pediatric AIDS monitoring, was commented.

Changes of blood CD16/CD56 (NK) and HLA-DR/CD3-positive lymphocyte amounts in HIV-infected children, as related to clinical progression and p24-antigen/p24-antibody presence

This study describes a series of immunological investigations carried out on a group of 37 HIV-seropositive children, aged 3-4 years, in two different stages of disease defined according to the CDC classification; the Primary stage, an asymptomatic one, showing abnormal immune function (P1-Class, B-Subclass) and the Secondary stage, 6-8 months later, in which patients exhibited non-specific findings, i.e., loss of weight, persistent generalized lymphadenopathy and hepatosplenomegaly, associated with abnormal immune function (P2-Class, A-Subclass). In both stages, immune function was considered 'abnormal' when lymphopenia and a decrease of the CD4/CD8-cell ratio were found. The phenotypes CD16+/56+ (NK) and HLA-DR+/CD3+ (T-activated?)-positive cells, were assessed by flow cytometry, and the following supplementary systemic humoral markers were investigated in homologus serum samples; total HIV(gp)-antibody, HIV(p24)-antibody and p24-antigen presence. If at the primary stage, no significant difference from to the reference values corresponding to the age was noticed, at the Secondary stage the obtained data is presented separately in two subgroups, namely the A-subgroup characterized by the presence of total HIV(gp)-antibody, the presence of HIV(p24)-antibody and the absence of p24-antigenaemia, and the B-subgroup, where total HIV(gp)-antibody was present, HIV(p24)-antibody absent and p24-antigenaemia present. A significant decrease of CD16+/56+ (NK)-cells was found within the two subgroups. As far as HLA-DR+ from CD(3+)-cells was concerned, only those within the B-subgroup showed a high percentage level, compared to the reference values. The importance of the present findings, linked to immune monitoring of HIV infection among children, is discussed.