Reduction in maximum pain after surgery in temporomandibular joint patients is associated with decreased beta-endorphin levels - a pilot study

The mechanisms of relief from persistent pain after temporomandibular joint (TMJ) surgery are not well studied. It was hypothesized that if persistent pain is relieved by TMJ surgery, up-regulated parts of the central nervous system will be desensitized and the neuroendocrine opioid release will decrease back to normal levels. Eleven female patients with a mean age of 47.4±19.4 years and with TMJ pain due to chronic closed lock were examined before and 6-24 months after TMJ discectomy. The effects on plasma β-endorphin levels, pain intensity, and pain thresholds were analyzed. Plasma β-endorphin levels (P=0.032), pain at rest (P=0.003), and movement-evoked pain (P=0.008) were all significantly reduced at follow-up. The reduction in plasma β-endorphin levels correlated with a reduction in maximum pain intensity (P=0.024) and with a longer time after surgery (P=0.041). Seven out of eight patients who reported a substantial reduction in maximum pain intensity presented a decrease in β-endorphin levels in the plasma. In conclusion, this pilot study showed a significant reduction in plasma β-endorphin levels and pain intensity at 6-24 months after TMJ surgery; plasma β-endorphin levels were correlated with time after surgery. However, the results must be interpreted with caution since this was a single-centre observational study with a small sample size. If replicated in larger sample sets, the measurement of β-endorphin levels may be of prognostic value for the treatment outcome.

Different expression levels of glycans on leukemic cells-a novel screening method with molecularly imprinted polymers (MIP) targeting sialic acid

Sialic acid (SA) is normally expressed on the cell membranes and is located at the terminal position of the sugar chains. SA plays an important role for regulation of the innate immunity, function as markers of the cells and can be recognized by a variety of receptors. Interestingly, the level of SA expression is increased on metastatic cancer cells. The availability of specific antibodies against SA is limited and, therefore, biomarker tools for detection of SA are lacking. We have recently presented a novel method for specific fluorescence labeling of SA molecular imprinted polymers (MIP). Here, we have performed an extended screening of SA expression by using SA-MIP and included four different chronic lymphocytic leukemia (CLL) cell lines, conveniently analyzed by flow cytometry and fluorescence microscopy. SA expression was detected in four cell lines at different levels, and the SA expression were verified with lectin-FITC. These results show that SA-MIP can be used as a plastic antibody for detection of SA using both flow cytometry and fluorescence microscopy. We suggest that SA-MIP can be used for screening of different tumor cells of various stages, including CLL cells.

Thermal conductivity versus depth profiling of inhomogeneous materials using the hot disc technique

Transient measurements of thermal conductivity are performed with hot disc sensors on samples having a thermal conductivity variation adjacent to the sample surface. A modified computational approach is introduced, which provides a method of connecting the time-variable to a corresponding depth-position. This allows highly approximate-yet reproducible-estimations of the thermal conductivity vs. depth. Tests are made on samples incorporating different degrees of sharp structural defects at a certain depth position inside a sample. The proposed methodology opens up new possibilities to perform non-destructive testing; for instance, verifying thermal conductivity homogeneity in a sample, or estimating the thickness of a deviating zone near the sample surface (such as a skin tumor), or testing for presence of other defects.

Cerebrospinal fluid markers of central nervous system injury in decompression illness - a case-controlled pilot study

INTRODUCTION

Decompression sickness (DCS) may cause a wide variety of symptoms, including central nervous system (CNS) manifestations. The main objective of this study was to examine whether DCS is associated with neuronal injury, and whether DCS could result in altered amyloid metabolism.

METHODS

Seven, male divers with DCS and seven age-matched controls were included in the study. All the divers were treated by recompression but the controls did not receive hyperbaric oxygen. Cerebrospinal fluid (CSF) samples were collected 7-10 days after the diving injury and at three months follow-up. CSF biomarkers of neuronal injury, astroglial Injury/activation, and a range of markers of amyloid β (Aβ) metabolism, as well as two proinflammatory interleukins, were analysed using immunochemical methods.

RESULTS

There were no significant differences in the best-established CSF markers of neuronal injury, total tau (T-tau) and neurofilament light, between DCS patients and controls or between the two sampling time points. Also, there were no significant changes in the astroglial or amyloid (Aβ)-related markers between DCS patients and controls. However, the only diver with CNS symptoms had the highest levels of CSF T-tau, Aβ38, Aβ40 and Aβ42.

CONCLUSION

The results of our study speak against subclinical CNS injury or induction of inflammation or amyloid build-up in the brain among the six DCS patients without neurological symptoms. Further research, including on divers with CNS DCS, is justified.

Fe(III) distribution varies substantially within and between atherosclerotic plaques

PURPOSE

Vulnerable atherosclerotic plaques are structurally weak and prone to rupture, presumably due to local oxidative stress. Redox active iron is linked to oxidative stress and the aim of this study was to investigate the distribution of Fe(III) in carotid plaques and its relation to vulnerability for rupture.

METHODS

Atherosclerotic plaques from 10 patients (three asymptomatic and seven symptomatic) were investigated. Plaque vulnerability was classified using ultrasound and immunohistochemistry and correlated to Fe(III) measured by electron paramagnetic resonance spectroscopy.

RESULTS

Large intra-plaque Fe(III) variations were found. Plaques from symptomatic patients had a higher Fe(III) concentration as compared with asymptomatic plaques (0.36 ± 0.21 vs. 0.06 ± 0.04 nmol Fe(III)/mg tissue, P < 0.05, in sections adjoining narrowest part of the plaques). All but one plaque from symptomatic patients showed signs of cap rupture. No plaque from asymptomatic patients showed signs of cap rupture. There was a significant increase in cap macrophages in plaques from symptomatic patients compared with asymptomatic patients (31 ± 11% vs. 2.3 ± 2.3%, P < 0.01).

CONCLUSION

Fe(III) distribution varies substantially within atherosclerotic plaques. Plaques from symptomatic patients had significantly higher concentrations of Fe(III), signs of cap rupture and increased cap macrophage activity.

Relatively high mortality risk in elderly Swedish subjects with low selenium status

Background/Objectives:

The daily dietary intake of selenium (Se), an essential trace element, is still low in Sweden in spite of decades of nutritional information campaigns and the effect of this on the public health is presently not well known. The objective of this study was to determine the serum Se levels in an elderly Swedish population and to analyze whether a low Se status had any influence on mortality.

Subjects/Methods:

Six-hundred sixty-eight (n=668) elderly participants were invited from a municipality and evaluated in an observational study. Individuals were followed for 6.8 years and Se levels were re-evaluated in 98 individuals after 48 months. Clinical examination of all individuals included functional classification, echocardiography, electrocardiogram and serum Se measurement. All mortality was registered and endpoints of mortality were assessed by Kaplan–Meier plots, and Cox proportional hazard ratios adjusted for potential confounding factors were calculated.

Results:

The mean serum Se level of the study population (n=668) was 67.1 μg/l, corresponding to relatively low Se intake. After adjustment for male gender, smoking, ischemic heart disease, diabetes, chronic obstructive pulmonary disease and impaired heart function, persons with serum Se in the lowest quartile had 43% (95% confidence interval (CI): 1.02–2.00) and 56% (95% CI: 1.03–2.36) increased risk for all-cause and cardiovascular mortality, respectively. The result was not driven by inflammatory effects on Se concentration in serum.

Conclusion:

The mean serum Se concentration in an elderly Swedish population was 67.1 μg/l, which is below the physiological saturation level for several selenoprotein enzymes. This result may suggest the value of modest Se supplementation in order to improve the health of the Swedish population.

Silenced B-cell receptor response to autoantigen in a poor-prognostic subset of chronic lymphocytic leukemia

Chronic lymphocytic leukemia B cells express auto/xeno antigen-reactive antibodies that bind to self-epitopes and resemble natural IgM antibodies in their repertoire. One of the antigenic structures recognized is oxidation-induced malonedialdehyde that is present on low-density lipoprotein, apoptotic blebs, and on certain microbes. The poor-prognostic stereotyped subset #1 (Clan I IGHV genes-IGKV1(D)-39) express IgM B-cell receptors that bind oxidized low-density lipoprotein. In this study, we have used for the first time this authentic cognate antigen for analysis of downstream B-cell receptor-signal transduction events, since it is more faithful to B-cell physiology than anti-IgM. Multivalent oxidized low-density lipoprotein showed specific binding to subset #1 IgM/IgD B-cell receptors, whereas native low-density lipoprotein did not. The antigen binding induced prompt receptor clustering followed by internalization. However, the receptor-signal transduction was silenced, revealing no Ca(2+) mobilization or cell-cycle entry, while phosphorylated extracellular-regulated kinase 1/2 basal levels were high and could not be elevated further by oxidized low-density lipoprotein. Interestingly, B-cell receptor responsiveness was recovered after 48-h culture in the absence of antigen in half of the cases. Toll-like receptor 9-ligand was found to breach the B-cell receptor-signaling incompetence in 5 of 12 cases pointing to intra-subset heterogeneity. Altogether, this study supports B-cell receptor unresponsiveness to cognate self-antigen on its own in poor-prognostic subset #1 chronic lymphocytic leukemia, indicating that these cells proliferate by other mechanisms that may override B-cell receptor silencing brought about in a context of self-tolerance/anergy. These novel findings have implications for the understanding of chronic lymphocytic leukemia pathobiology and therapy.

Molecular characterization of neoplastic and normal "sister" lymphoblastoid B-cell lines from chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) B-cells resemble self-renewing CD5 + B-cells carrying auto/xeno-antigen-reactive B-cell receptors (BCRs) and multiple innate pattern-recognition receptors, such as Toll-like receptors and scavenger receptors. Integration of signals from BCRs with multiple surface membrane receptors determines whether the cells will be proliferating, anergic or apoptotic. To better understand the role of antigen in leukemogenesis, CLL cell lines producing monoclonal antibodies (mAbs) will facilitate structural analysis of antigens and supply DNA for genetic studies. We present here a comprehensive genotypic and phenotypic characterization of available CLL and normal B-cell-derived lymphoblastoid cell lines (LCLs) from the same individuals (n = 17). Authenticity and verification studies of CLL-patient origin were done by IGHV sequencing, fluorescence in situ hybridization (FISH) and DNA/short tandem repeat (STR) fingerprinting. Innate B-cell features, i.e. natural Ab production and CD5 receptors, were present in most CLL cell lines, but in none of the normal LCLs. This panel of immortalized CLL-derived cell lines is a valuable reference representing a renewable source of authentic Abs and DNA.

A protein disulfide isomerase/thioredoxin-1 complex is physically attached to exofacial membrane tumor necrosis factor receptors: overexpression in chronic lymphocytic leukemia cells

AIMS

The 3D structures and functions of cysteine-rich receptors such as tumor necrosis factor receptors (TNFRs) are redox-modulated by dithiol-disulfide exchange. TNFR superfamily members participate in growth regulation in B-cell chronic lymphocytic leukemia (CLL), and tissue stromal cells interact with leukemia cells, profoundly affecting their viability via release of redox-active components, including cysteine, thioredoxin-1 (Trx1), and Trx reductase. Trx1 was previously shown to enhance release of TNF, which acts as an autocrine/paracrine growth factor in CLL. The nature of the mechanism is not known, however. Here, we investigated whether Trx1 and protein disulfide isomerase (PDI), a chaperone and Trx-family member, may interact with TNFRs.

RESULTS

We found direct physical association between PDI and TNFR1 or TNFR2 by coclustering and affinity isolation. PDI (57 kDa) formed covalent/reduction-sensitive 69-kDa complexes with Trx1 (12 kDa) in a majority of CLL cell samples, detected at low levels only in control B-cells. Functionally, the TNF/TNFR signaling via the nuclear factor kappa B-driven autocrine loop was disrupted in a dose-dependent fashion by PDI-inhibitors bacitracin, anti-PDI, or anti-Trx1 antibodies, resulting in reduced viability. PDI was significantly overexpressed in immunoglobulin heavy-chain variable (IGHV) unmutated versus mutated CLL (p=0.0102), and amplified TNF release was observed in the former group.

INNOVATION

This study points out a previously unrecognized physical and functional association of TNFRs with the redox-active proteins PDI and Trx1.

CONCLUSION

We describe here a new level of TNF regulation, in which membrane TNFRs are redox controlled at the exofacial surface by PDI/Trx1. These findings shed new light on the observed survival benefit in CLL B-cells exerted by TNFR-superfamily ligands and point at potential therapeutic strategies.

A systematic approach to improve oral and maxillofacial surgery education

To improve teaching quality and student satisfaction, a new curriculum in Oral Surgery was implemented at Karolinska Institutet in 2007. This paper describes the curriculum change as well as the results regarding quality, satisfaction, cost-effectiveness and workload for teachers and staff. To design the new curriculum, all members of the teaching staff participated in a series of group discussions where problems with the previous curriculum were identified and ideas on how to improve the curriculum were discussed. Cost-effectiveness was evaluated by comparing the number of teaching sessions between the new and the old curriculum. A questionnaire was used to investigate the staffs' perceived change in workload and teaching quality. The students' satisfaction and attitudes to learning was screened for by on-line questionnaires. The large amount of passive observational teaching was considered as the main problem with the old curriculum. Half of these sessions were replaced by either clinical seminars or demonstrations performed in an interactive form. Students rated the new curriculum as a clear improvement. Analyses of time and cost-effectiveness showed a decrease in teaching sessions by almost 50%. Generally, the teachers were more positive towards the changes compared to the non-teaching staff. The students rated the new type of learning activities relatively high, whilst the traditional observational teaching was seen as less satisfactory. They preferred to learn in a practical way and few indicated analytic or emotional preferences. The majority of the students reported a good alignment between the new course curriculum and the final exam.

Orthognathic bimaxillary surgery in two patients with osteogenesis imperfecta and a review of the literature

Orthognathic surgery in patients with osteogenesis imperfecta is rare. Most cases result in a successful outcome with stable and good occlusion. Two patients with, probably severe types III and IV, and malocclusion class III with retrognathic maxilla and prognathic mandible, were treated with orthodontic treatment and bimaxillary surgical correction. The surgical outcome and follow up are presented together with a review of published cases of orthognathic surgery in patients with different types of osteogenesis imperfecta. The authors conclude that it is possible to perform combined orthodontic and orthognathic surgery in patients with osteogenesis imperfecta despite the greater risk of complications. The treatments were successful with follow up times of 5-6 years.

Antigens in chronic lymphocytic leukemia--implications for cell origin and leukemogenesis

Several types of B cell tumors, particularly MALT lymphomas, are known to have an antigen-driven component in tumor development. Over the past two decades substantial data have accumulated regarding the restricted immunoglobulin (IG) gene repertoire in chronic lymphocytic leukemia (CLL) and its potential implications for antigenic drive in the disease development and progression. Herein we discuss how evidence first illustrated a link between certain B cell receptor (BCR) specificities and disease outcome and the subsequent large-scale IG analyses which revealed the extent of "stereotyped" BCRs in CLL. More recent studies on CLL antibody reactivity have gradually provided clues as to which antigens may be involved in the tumor development. Significantly, CLL monoclonal antibodies have been shown to resemble natural antibodies recognizing molecular motifs both on apoptotic cells (e.g. modified cytoskeletal proteins and oxidation-specific epitopes), as well as exogenous bacteria, indicating that CLL clones possibly arise from B cells which have dual function as scavengers of apoptotic debris, while also having the ability to bind conserved bacterial cell structures. Such revelations have led us to re-evaluate both the phenotypic and functional characteristics of the tumor B cells and the pathway by which CLL arises and develops.

Myelin protein zero is naturally processed in the B cells of monoclonal gammopathy of undetermined significance of immunoglobulin M isotype: aberrant triggering of a patient's T cells

BACKGROUND

Monoclonal gammopathy of undetermined significance of immunoglobulin M isotype is a condition with clonally expanded B cells, recently suggested to have an infectious origin. This monoclonal gammopathy is frequently associated with polyneuropathy and antibodies against myelin protein zero, whereas the role of the T cells remains largely unknown. We analyzed protein zero-specific B cells, as antigen-presenting cells, and their capacity to activate T helper cells.

DESIGN AND METHODS

We used a well-characterized monoclonal gammopathy of undetermined significance-derived B-cell line, TJ2, expressing anti-protein zero immunoglobulin M. The ability of TJ2 cells to bind, endocytose, process, and present protein zero was investigated by receptor-clustering and immunofluorescence. The activation of protein zero-specific autologous T cells was studied by measuring interleukin-2 and interferon-gamma with flow cytometry, immunobeads, and enzyme-linked immunospot assays.

RESULTS

Surface-receptor clustering and endocytosis of receptor-ligand (immunoglobulin M/protein zero) complexes were pronounced after exposure to protein zero. Naturally processed or synthetic protein zero peptide (194-208)-pulsed TJ2 cells significantly induced interleukin-2 secretion from autologous T cells compared to control antigen-pulsed cells (P<0.001). The numbers of interferon-gamma-producing T helper cells, including CD4(+)/CD8(+) cells, were also significantly increased (P=0.0152). Affinity-isolated naturally processed myelin peptides were potent interferon-gamma stimulators for autologous peripheral blood mononuclear cells, but not for control peripheral blood mononuclear cells.

CONCLUSIONS

We show for the first time that myelin protein zero is naturally processed in B cells from monoclonal gammopathy of undetermined significance of immunoglobulin M isotype, acting as aberrant antigen-presenting cells in activation of a patient's T helper cells. Our findings cast new light on the important role of autoreactive protein zero-specific B cells in the induction of the pathogenic T-cell responses found in nerve lesions of patients with monoclonal gammopathy of undetermined significance with peripheral neuropathy.

4-thiouridine induces dose-dependent reduction of oedema, leucocyte influx and tumour necrosis factor in lung inflammation

Recent reports demonstrate a role for nucleotides as inflammatory modulators. Uridine, for example, reduces oedema formation and leucocyte infiltration in a Sephadex-induced lung inflammation model. Tumour necrosis factor (TNF) concentration was also reduced. Previous in vivo observations indicated that 4-thiouridine might have similar effects on leucocyte infiltration and TNF release. The aim of this study was thus to investigate the effects of 4-thiouridine in greater detail. We used a Sephadex-induced acute lung inflammation model in Sprague-Dawley rats. The dextran beads were instilled intratracheally into the lungs, which were excised and examined after 24 h. Sephadex alone led to massive oedema formation and infiltration of macrophages, neutrophils and eosinophils. Microgranulomas with giant cell formations were clearly visible around the partially degraded beads. A significant increase in bronchoalveolar lavage fluid (BALF) content of TNF and leukotrienes was also seen. 4-Thiouridine co-administration affected all variables investigated in this model, i.e. oedema, microscopic and macroscopic appearance of lung tissue, total leucocyte and differential leucocyte counts in BALF, TNF and leukotrienes C(4) (LTC(4)), LTD(4 )and LTE(4) in BALF, indicating a reproducible anti-inflammatory effect. In conclusion, we have demonstrated that 4-thiouridine has anti-inflammatory effects similar to those of uridine. To our knowledge, this is the first demonstration of pharmacological 4-thiouridine effects in vivo. The results suggest nucleoside/nucleotide involvement in inflammatory processes, warranting further studies on nucleoside analogues as attractive new alternatives in the treatment of inflammatory diseases.

Positive MRI contrast enhancement in THP-1 cells with Gd2O3 nanoparticles

There is a demand for more efficient and tissue-specific MRI contrast agents and recent developments involve the design of substances useful as molecular markers and magnetic tracers. In this study, nanoparticles of gadolinium oxide (Gd2O3) have been investigated for cell labeling and capacity to generate a positive contrast. THP-1, a monocytic cell line that is phagocytic, was used and results were compared with relaxivity of particles in cell culture medium (RPMI 1640). The results showed that Gd2O3-labeled cells have shorter T1 and T2 relaxation times compared with untreated cells. A prominent difference in signal intensity was observed, indicating that Gd2O3 nanoparticles can be used as a positive contrast agent for cell labeling. The r1 for cell samples was 4.1 and 3.6 s(-1) mm(-1) for cell culture medium. The r2 was 17.4 and 12.9 s(-1) mm(-1), respectively. For r1, there was no significant difference in relaxivity between particles in cells compared to particles in cell culture medium, (p(r1) = 0.36), but r2 was significantly different for the two different series (p(r2) = 0.02). Viability results indicate that THP-1 cells endure treatment with Gd2O3 nanoparticles for an extended period of time and it is therefore concluded that results in this study are based on viable cells.