Thalidomide treatment down-regulates SDF-1 alpha and CXCR4 expression in multiple myeloma patients

The chemokine stromal-derived factor-1 alpha (SDF-1 alpha) and its receptor CXCR4 are critically involved in directional migration and homing of plasma cells in multiple myeloma. Here, we show that the expression of SDF-1 alpha and CXCR4 was significantly down-regulated in patients treated with thalidomide (n = 10) as compared to newly diagnosed MM patients (n = 31) and MM patients treated with other drugs (n = 38). SDF-1 alpha and CXCR4 expression was also significantly decreased in a RPMI 8226 cell line treated with 10 and 20 mu mol/L of thalidomide. Our findings indicate that thalidomide therapy induces down-regulation of CXCR4 and its ligand SDF-1 alpha in multiple myeloma. (c) 2008 Elsevier Ltd. All rights reserved.

Direct evidence for the expression of multiple endogenous retroviruses in the synovial compartment in rheumatoid arthritis

Objective. Circumstantial evidence links retroviruses (RVs) with human autoimmune diseases, The aim of the present study was to obtain direct evidence of RV gene expression in rheumatoid arthritis (RA). Methods. Synovial samples were obtained from patients with RA, patients with osteoarthritis (OA), and normal control subjects, Reverse transcription-polymerase chain reaction (RT-PCR) was performed using synovial RNA and primers to conserved sequences in the polymerase (pol) genes of known RVs. Results. PCR products (n = 857) were cloned and sequenced, Multiple pol transcripts, many with open reading frames, were expressed in every sample, Sequences were aligned and classified into 6 families (F1-F6) that contained 33 groups of known and unknown endogenous RVs (ERVs), each distinguished by a specific, deduced peptide motif, The frequency of sequences in each family was similar between RA, OA, and normal synovial tissue, but differed significantly in RA synovial fluid cells, F1 sequences (undefined, but related to murine and primate type C RVs) were lower in frequency, F2 (ERV-9-related), F4 (HERV-K-related), and F6 (HERV-L-related) sequences were higher in frequency, and F3 (RTVL-H-related) sequences were not detected, in the RA synovial fluid cells compared with the RA synovial tissues. Conclusion. Multiple ERVs are expressed in normal and diseased synovial compartments, but specific transcripts can be differentially expressed in RA.

Factors affecting hematopoietic progenitor cell mobilization: An analysis of 307 patients

We reviewed the data of 307 patients treated with autologous bone marrow transplantation with the aim to identify factors associated with poor hematopoietic stern cell (HSC) mobilization after administration of cyclophosphamide and granulocyte-colony stimulating factor. Success in mobilization was defined when >= 2.0 x 10(6) CD34+ cells/kg weight could be collected with <= 3 leukapheresis procedures. Success was observed in 260 patients (84.7%) and nonsuccess in 47 patients (15.3%). According to the stepwise regression model: diagnosis, chemotherapy load, treatment with mitoxantrone and platelet count before mobilization were found to be independent predictive factors for HSC mobilization. These results could help in the previous recognition of patients at risk for non response to mobilization and allow to plan an alternative protocol for this group of patients. (C) 2008 Elsevier Ltd. All rights reserved.

Proteomic characterization of the multiple forms of the PLAs from the venom of the social wasp Polybia paulista

The phospholipases A(1) (PLA(1)s) from the venom of the social wasp Polybia paulista occur as a mixture of different molecular forms. To characterize the molecular origin of these structural differences, an experimental strategy was planned combining the isolation of the pool of PLAs from the wasp venom with proteomic approaches by using 2-D, MALDI-TOF-TOF MS and classical protocols of protein chemistry, which included N- and C-terminal sequencing. The existence of an intact form of PLA(1) and seven truncated forms was identified, apparently originating from controlled proteolysis of the intact protein; in addition to this, four of these truncated forms also presented carbohydrates attached to their molecules. Some of these forms are immunoreactive to specific-IgE, while others are not. These observations permit to raise the hypothesis that naturally occurring proteolysis of PLA(1), combined with protein glycosylation may create a series of different molecular forms of these proteins, with different levels of allergenicity. Two forms of PLA(2)s, apparently related to each other, were also identified; however, it was not possible to determine the molecular origin of the differences between both forms, except that one of them was glycosylated. None of these forms were immunoreactive to human specific IgE.

A single dose of zoledronic acid reverses the deleterious effects of glucocorticoids on titanium implant osseointegration

This study evaluates the effect of zoledronic acid (ZOL) on the osseointegration of titanium implants in rabbits with glucocorticoid (GC)-induced bone loss, and our findings demonstrated that a single dose of ZOL is able to reverse the detrimental effects of GCs on the osseointegration of titanium implants. The purpose of this study is to evaluate the effect of ZOL on the osseointegration of titanium implants in rabbits with GC-induced bone loss. Three groups of six NZW rabbits were treated for 18 weeks with saline (SALINE), GC (methylprednisolone, 0.35 mg/kg three times a week), or GC + ZOL (methylprednisolone + single dose of ZOL, 0.1 mg/kg). The animals received a titanium implant in the left tibia after 6 weeks and were killed at the 18th week. Bone mineral density (BMD) was measured with dual-energy X-ray absorptiometry at baseline, eighth week (W8), and 18th week (W18) after treatment to determine the change upon treatment (a dagger BMD). Histomorphometric and serum bone alkaline phosphatase analysis (BAP) were also performed. At W8, GC group had a significant reduction in lumbar spine and tibia BMD compared with SALINE (p = 0.003 and p = 0.000), as also observed for GC + ZOL group (p = 0.014 and p = 0.003) just 2 weeks after ZOL treatment. In contrast, at W18, the GC + ZOL had an evident BMD rescue with similar lumbar spine and tibia a dagger BMD compared with SALINE (0.043 +/- 0.006 vs. 0.055 +/- 0.009 g/cm(2), p = 0.457 and 0.027 +/- 0.003 vs. 0.041 +/- 0.011 g/cm(2), p = 0.232) and a significantly higher a dagger BMD compared with the GC (p = 0.024 and p = 0.001). Histomorphometry revealed that osseointegration was significantly reduced in GC (tibia cortical thickness and diameter, bone-implant contact, total and peri-implant bone area) whereas GC + ZOL had these parameters similar to SALINE (p > 0.05). Likewise, ZOL reversed the BAP alteration induced by GC. Our findings demonstrated that a single dose of ZOL is able to reverse the detrimental effects of glucocorticoids on the osseointegration of titanium implants, suggesting that ZOL therapy may improve the outcome of bone implants in patients with glucocorticoid-induced osteoporosis.

Endotoxin tolerance: Selective alterations in gene expression and protection against lymphocyte death

Extensive lymphocyte apoptosis may be an important cause of immune suppression in sepsis. Here we investigated the effect of LPS tolerance on lymphocyte apoptosis in an experimental model of polymicrobial infection. Tolerance was induced by the injection of lipopolysaccharide (1.0 mg/kg/subcutaneously) once a day for 5 days. Macroarray analysis of mRNA isolated from T-(CD4) lymphocytes was used to identify genes that are differentially expressed during LPS tolerance. In addition, assessment of the expression of apoptosis-associated lymphocyte gene products and apoptotic events was performed on the 8th day; 6 h after the terminal challenge with polymicrobial infection or high-dose LPS administration. Survival studies with polymicrobial infection were also conducted. LPS tolerance induced a broad reprogramming of cell death pathways, including a suppression of receptor-mediated and mitochondrial apoptotic pathways, inflammatory caspases, alternate apoptotic pathways, as well as reduced expression of genes involved in necrosis. These alterations led to a marked resistance of lymphocytes against cell death during the subsequent period of sepsis. In addition, LPS tolerance produced an increased differentiation of T-lymphocytes to T(H)1 and T(H)2, with a T(H)1 differentiation predominance. Thus, in the current study we provide an evidence for a marked reprogramming of gene expression of multiple cell death pathways during LPS tolerance. These alterations may play a significant role in the observed protection of the animals from a subsequent lethal polymicrobial sepsis challenge. (C) 2009 Elsevier GmbH. All rights reserved.

Prediction of psychological adjustment to multiple sclerosis

This study examined the utility of self-efficacy as a predictor of social activity and mood control in multiple sclerosis (MS). Seventy-one subjects with MS were recruited from people attending an MS centre or from a mailing list and were examined on two occasions that were two months apart. Clinic patients were more disabled than patients who completed assessments by post, but they were of higher socioeconomic status and were less dysphoric; We attempted to predict self-reported performance of mood control and social activity at two months, from self-efficacy or performance on these tasks at pretest. Demographic variables, disorder status, disability, self-esteem and depression were also allowed to compete for entry into multiple regressions. Substantial stability in mood, performance and disability was observed over the two months. In both mood control and social activity, past performance was the strongest predictor of later performance, but self-efficacy also contributed significantly to the prediction. The disability level entered a prediction of social activity; but no other variables predicted either type of performance. A secondary analysis predicting self-esteem at two months also included self-efficacy for social activity, illustrating the contribution of perceived capability to later assessments of self-worth. The study provided support for self-efficacy as a predictor of later behavioural outcomes and self-esteem in multiple sclerosis. (C) 1997 Elsevier Science Ltd.

IMAGE QUANTIFICATION FOR RADIATION DOSE CALCULATIONS-LIMITATIONS AND UNCERTAINTIES

Radiation dose calculations in nuclear medicine depend on quantification of activity via planar and/or tomographic imaging methods. However, both methods have inherent limitations, and the accuracy of activity estimates varies with object size, background levels, and other variables. The goal of this study was to evaluate the limitations of quantitative imaging with planar and single photon emission computed tomography (SPECT) approaches, with a focus on activity quantification for use in calculating absorbed dose estimates for normal organs and tumors. To do this we studied a series of phantoms of varying complexity of geometry, with three radionuclides whose decay schemes varied from simple to complex. Four aqueous concentrations of (99m)Tc, (131)I, and (111)In (74, 185, 370, and 740 kBq mL(-1)) were placed in spheres of four different sizes in a water-filled phantom, with three different levels of activity in the surrounding water. Planar and SPECT images of the phantoms were obtained on a modern SPECT/computed tomography (CT) system. These radionuclides and concentration/background studies were repeated using a cardiac phantom and a modified torso phantom with liver and ""tumor"" regions containing the radionuclide concentrations and with the same varying background levels. Planar quantification was performed using the geometric mean approach, with attenuation correction (AC), and with and without scatter corrections (SC and NSC). SPECT images were reconstructed using attenuation maps (AM) for AC; scatter windows were used to perform SC during image reconstruction. For spherical sources with corrected data, good accuracy was observed (generally within +/- 10% of known values) for the largest sphere (11.5 mL) and for both planar and SPECT methods with (99m)Tc and (131)I, but were poorest and deviated from known values for smaller objects, most notably for (111)In. SPECT quantification was affected by the partial volume effect in smaller objects and generally showed larger errors than the planar results in these cases for all radionuclides. For the cardiac phantom, results were the most accurate of all of the experiments for all radionuclides. Background subtraction was an important factor influencing these results. The contribution of scattered photons was important in quantification with (131)I; if scatter was not accounted for, activity tended to be overestimated using planar quantification methods. For the torso phantom experiments, results show a clear underestimation of activity when compared to previous experiment with spherical sources for all radionuclides. Despite some variations that were observed as the level of background increased, the SPECT results were more consistent across different activity concentrations. Planar or SPECT quantification on state-of-the-art gamma cameras with appropriate quantitative processing can provide accuracies of better than 10% for large objects and modest target-to-background concentrations; however when smaller objects are used, in the presence of higher background, and for nuclides with more complex decay schemes, SPECT quantification methods generally produce better results. Health Phys. 99(5):688-701; 2010

Measurement of radiation dose received by the hands and thyroid of staff performing gridless fluoroscopic procedures in children

The aim of this study was to confirm that the radiation doses received by attendants who manually restrain infants during fluoroscopic procedures are low. Doses to the hands and neck of three radiologists and three nurses performing or assisting at all the fluoroscopic procedures in a children's hospital were measured for 1 month using thermoluminescent dosemeters. All fluoroscopy on children at this hospital is performed without an antiscatter grid. Total doses for the neck ranged from 20 to 50 mu Sv per week and for hands from 40 to 210 mu Sv per week. These doses were shared by the three radiologists and the three nurses. Individual doses received per staff member are very small when compared with the doses received by interventional radiology staff. Doses received by staff in this study were of the order of 5% of the limit advised by the National Health and Medical Research Council of Australia (NHMRC) for radiation workers. Nurses received larger doses than radiologists and steps will be taken to reduce this dose further.

Measuring macromolecular diffusion using heteronuclear multiple-quantum pulsed-field-gradient NMR

We have previously shown that H-1 pulsed-field-gradient (PFG) NMR spectroscopy provides a facile method for monitoring protein self-association and can be used, albeit with some caveats, to measure the apparent molecular mass of the diffusant [Dingley et al. (1995) J. Biomol. NMR, 6, 321-328]. In this paper we show that, for N-15-labelled proteins, selection of H-1-N-15 multiple-quantum (MQ) coherences in PFG diffusion experiments provides several advantages over monitoring H-1 single-quantum (SQ) magnetization. First, the use of a gradient-selected MQ filter provides a convenient means of suppressing resonances from both the solvent and unlabelled solutes. Second, H-1-N-15 zero-quantum coherence dephases more rapidly than H-1 SQ coherence under the influence of a PFG. This allows the diffusion coefficients of larger proteins to be measured more readily. Alternatively, the gradient length and/or the diffusion delay may be decreased, thereby reducing signal losses from relaxation. In order to extend the size of macromolecules to which these experiments can be applied, we have developed a new MQ PFG diffusion experiment in which the magnetization is stored as longitudinal two-spin order for most of the diffusion period, thus minimizing sensitivity losses due to transverse relaxation and J-coupling evolution.

An isolated perfused human placental lobule model for multiple indicator dilution studies

We describe a method for multiple indicator dilution studies in the isolated perfused human placental lobule developed to investigate the relationships between changes in pressure and flow and solute clearance. A peripheral lobule of a human placenta is perfused with a tissue culture-based medium and the perfusate oxygen tension, arterial and venous pressures, pH and perfusion temperature continuously monitored by a computerized system. Flow rates are readily changed. Bolus injections of vascular, extracellular and water space markers, and study compounds can be made into either maternal or fetal circulations, and precisely timed outflow fractions can be collected with computer-controlled fraction collectors, allowing simultaneous determination of concentration-time profiles of each marker. (C) 1997 Elsevier Science Inc.

Modeling of subcutaneous absorption kinetics of infusion solutions in the elderly using technetium

Absorption kinetics of solutes given with the subcutaneous administration of fluids is ill-defined. The gamma emitter, technitium pertechnetate, enabled estimates of absorption rate to be estimated independently using two approaches. In the first approach, the counts remaining at the site were estimated by imaging above the subcutaneous administration site, whereas in the second approach, the plasma technetium concentration-time profiles were monitored up to 8 hr after technetium administration. Boluses of technetium pertechnetate were given both intravenously and subcutaneously on separate occasions with a multiple dosing regimen using three doses on each occasion. The disposition of technetium after iv administration was best described by biexponential kinetics with a V-ss of 0.30 +/- 0.11 L/kg and a clearance of 30.0 +/- 13.1 ml/min. The subcutaneous absorption kinetics was best described as a single exponential process with a half-life of 18.16 +/- 3.97 min by image analysis and a half-life of 11.58 +/- 2.48 min using plasma technetium time data. The bioavailability of technetium by the subcutaneous route was estimated to be 0.96 +/- 0.12. The absorption half-life showed no consistent change with the duration of the subcutaneous infusion. The amount remaining at the absorption site with time was similar when analyzed using image analysis, and plasma concentrations assuming multiexponential disposition kinetics and a first-order absorption process. Profiles of fraction remaining at the absorption sire generated by deconvolution analysis, image analysis, and assumption of a constant first-order absorption process were similar. Slowing of absorption from the subcutaneous administration site is apparent after the last bolus dose in three of the subjects and can De associated with the stopping of the infusion. In a fourth subject, the retention of technetium at the subcutaneous site is more consistent with accumulation of technetium near the absorption site as a result of systemic recirculation.

Impulse-response studies on tracer doses of [C-14]lignocaine and its multiple metabolites in the perfused rat liver

The outflow-concentration-time profiles for lignocaine (lidocaine) and its metabolites have been measured after bolus impulse administration of [C-14]lignocaine into the perfused rat liver. Livers from female Sprague-Dawley rats were perfused in a once-through fashion with red-blood-cell-free Krebs-Henseleit buffer containing 0 or 2% bovine serum albumin. Perfusate flow rates of 20 and 30 mL min(-1) were used and both normal and retrograde flow directions were employed. Significant amounts of metabolite were detected in the effluent perfusate soon after lignocaine injection. The early appearance of metabolite contributed to bimodal outflow profiles observed for total C-14 radioactivity. The lignocaine outflow profiles were well characterized by the two-compartment dispersion model, with efflux rate << influx rate. The profiles for lignocaine metabolites were also characterized in terms of a simplified two-compartment dispersion model. Lignocaine was found to be extensively metabolized under the experimental conditions with the hepatic availability ranging between 0.09 and 0.18. Generally lignocaine and metabolite availability showed no significant change with alterations in perfusate flow rate from 20 to 30 mt min(-1) or protein content from 0 to 2%. A significant increase in lignocaine availability occurred when 1200 mu M unlabelled lignocaine was added to the perfusate. Solute mean transit times generally decreased with increasing flow rate and with increasing perfusate protein content. The results confirm that lignocaine pharmacokinetics in the liver closely follow the predictions of the well-stirred model. The increase in lignocaine availability when 1200 mu M unlabelled lignocaine was added to the perfusate is consistent with saturation of the hydroxylation metabolic pathways of lignocaine metabolism.

Use of multiple channel pH monitoring for evaluation of ultra-distal reflux in patients after fundoplication for treatment of Barrett`s esophagus

Dysplasia and esophageal adenocarcinoma may arise in patients with Barrett`s esophagus after fundoplication esophageal pH monitoring showing no acid in esophagus. This suggests the need to develop methodology to evaluate the occurrence of ultra-distal reflux (1 cm above the LES). The objective of the study was to compare acid exposition in three different levels: 5 cm above the upper border of the LES, 1 cm above the LES and in the intrasphincteric region. Eleven patients with Barrett`s esophagus after Nissen fundoplication with no clinical, endoscopic and radiologic evidence of reflux were selected. Four-channel pH monitoring took place: channel A, 5 cm above the upper border of the LES; channel B, 1 cm above the LES; channel C, intrasphincteric; channel D, intragastric. The results of channels A, B and C were compared. There was significant increase in number of reflux episodes and a higher fraction of time with pH <4.0 in channel B compared to channel A. There was significant decrease in fraction of time with pH <4.0 in channel B compared to channel C. Two cases of esophageal adenocarcinoma were diagnosed in the studied patients. The region 1 cm above the upper border of the LES is more exposed to acid than the region 5 cm above the upper border of the LES, although this exposure occurred in reduced levels. The region 1 cm above the upper border of the LES is less exposed to acid than the intrasphincteric region.

Novel gene containing multiple epidermal growth factor-like motifs transiently expressed in the papillae of the ascidian tadpole larvae

We have investigated molecular mechanisms of the embryonic development of an ascidian, a primitive chordate which shares features of both invertebrates and vertebrates, with a view to identifying genes involved in development and metamorphosis, We isolated 12 partial cDNA sequences which were expressed in a stage-specific manner using differential display, We report here the isolation of a full-length cDNA sequence for one of these genes which was specifically expressed during the tailbud and larval stages of ascidian development, This cDNA, 1213 bp in length, is predicted to encode a protein of 337 amino acids containing four epidermal growth factor (EGF)-like repeats and three novel cysteine-rich repeats, Characterization of its spatial expression pattern by in situ hybridisation in late tailbud and larval embryos demonstrated strong expression localised throughout the papillae and anteriormost trunk and weaker expression in the epidermis of the remainder of the embryo, As recent evidence indicates that the signal for metamorphosis originates in the anterior trunk region, these results suggest that this gene may have a role in signalling the initiation of metamorphosis. (C) 1997 Wiley-Liss, Inc.