Thiol redox control via thioredoxin and glutaredoxin systems

The Trx (thioredoxin) and Grx (glutaredoxin) systems control cellular redox potential, keeping a reducing thiol-rich intracellular state, which on generation of reactive oxygen species signals through thiol redox control mechanisms. Here, we give a brief overview of the human Trx and Grx systems. The main part focuses on our current knowledge about mitochondrial Grx2, which facilitates mitochondrial redox homoeostasis during oxidative stress-induced apoptosis.

Differential expression of chemokine receptors on human IgA+ and IgG+ B cells

Organ-specific lymphocyte homing is dependent on the expression of tissue-specific homing receptors and selected chemokine receptors. During the effector phase of an immune response, IgA and IgG antibody-secreting cells (ASC) are differently distributed in the body. Still, B cell expression of L-selectin and the mucosal homing receptor integrin alpha4beta7 is not related to the isotype produced, but only to the site of antigen encounter. In this study, we examined if differences in chemokine responsiveness between IgA+ and IgG+ B cells could explain their different tissue localization. Circulating CD19+ B cells were isolated and their expression of IgA, IgG, and selected chemokine receptors was determined by flow cytometry. Few Ig+ cells expressed CCR2, CCR3, or CCR9, and there was no difference in the expression of these receptors between IgA+ and IgG+ cells. In contrast, CCR4, CCR5, and CXCR3 was expressed on significantly more IgG+ than IgA+ cells. The function of chemokine receptors on memory B cells and ASC was then tested in the transwell system. IgG+ memory cells migrated to a higher extent than IgA+ cells towards the CXCR3 ligand CXCL11/I-TAC, while there was only a small migration towards the CCR4 ligand CCL17/TARC and the CCR9 ligand CCL25/TECK. ASC migrated poorly to all chemokines tested. In conclusion, this study shows that IgG+ and IgA+ memory B cells have a differential expression of the Th1 associated chemokine receptor CXCR3, as well as of CCR4 and CCR5. In contrast, none of the studied chemokine receptors was preferentially expressed by IgA+ cells.

Measurement of the absolute n p scattering differential cross section at 194 MeV

We describe a double-scattering experiment with a novel tagged neutron beam to measure differential cross sections for np backscattering to better than +/-2% absolute precision. The measurement focuses on angles and energies where the cross section magnitude and angle dependence constrain the charged pion-nucleon coupling constant, but existing data show serious discrepancies among themselves and with energy-dependent partial-wave analyses. The present results are in good accord with the partial-wave analyses, but deviate systematically from other recent measurements.

Helix pomatia a hemagglutinin, a surface marker for bovine T-lymphocytes

Bovine peripheral blood lymphocytes (PBL) were isolated from blood collected from 6 cattle. After treatment with neuraminidase, 40 or 60% of the cells were shown to combine with Helix Pomatia A hemagglutinin (HP) depending whether a direct or indirect fluorescence technique was used. About 20% of the cells were Ig-bearing. With double staining fluorescence technique, it was shown that cells attaching to HP were not Ig-bearing and the reverse. With the aid of HP, covalently bound to Sepharose, Ig-bearing cells could be separated from cell populations attaching to HP. The fraction of cells forming rosettes with sheep erythrocytes was proportional to that of HP attaching cells both before and after fractionation on the HP column. It is therefore concluded that HP is a marker for bovine T-cells, and that this lectin may be used to separate B-cells from T-cells.

Model simulations of NOx and ultrafine particles close to a Swedish highway

Based on the results from a 6-week monitoring campaign in an area close to a major highway north of Stockholm, Sweden, NOx emission factors representative for vehicle speeds of 100-120 km per h were determined to 0.61 g/veh,km for light duty and to 7.1 g/veh,km for heavy duty vehicles. The corresponding factors for particle number were 1.4 x 10(14) and 52 x 10(14) particles/veh,km, determined for an ambient temperature interval of +7 to +17 degrees C. The removal effects of coagulation and dry deposition on total number concentrations were assessed by numerical model simulations. Velocity and turbulence fields, including those produced by the vehicles, were simulated in a Computational Fluid Dynamics (CFD) model. Coagulation was found to be of little importance over the first 100 m downwind of the highway. The high friction velocities over the road surface created by vehicle movements enhanced deposition locally, contributing to the removal of approximately 10% of the particles originally emitted. Beyond a point 10 m downwind of the highway the removal rate was low and the ultrafine particles were almost inert while being advected over the next hundred meters. As a consequence, it seems reasonable to use monitored data from stations close to highways to estimate emission factors for particle number, assuming that the particles are inert. Those "effective" emission factors should be applicable for urban models with a larger spatial resolution.

The significance of radiolucent zones surrounding pedicle screws. Definition of screw loosening in spinal instrumentation

We examined the radiographs from a prospective clinical study of fixation by pedicle screws and those from an experimental study in a sheep model. In the clinical study, instruments were removed from 21 patients after implantation for 11 to 16 months and the extraction torques of the screws were recorded. A structured protocol was used for the radiological examinations. In the experimental study, loaded pedicle screw instrumentations were implanted in the sheep for six or 12 weeks. After radiological examination the pull-out resistance and the histological characteristics were studied. In the clinical study, all screws with radiolucent zones had a significantly reduced mean extraction torque compared with screws without radiolucent zones (16 +/- 10 Ncm v 403 +/- 220 Ncm; p < 0.0001). In the experimental study the mean maximum pull-out resistance for the screws with radiolucent zones was significantly lower than for those with no radiolucency (243 +/- 156 N v2214 +/- 578 N; p = 0.0006) and the mean bone-to-screw contact was reduced for screws with zones compared with those without zones (8 +/- 9% v 55 +/- 29%; p = 0.0002). Our findings showed that all screws with radiolucent zones had low extraction torques or low pull-out resistance. A radiolucent zone is a good indicator of loosening of a pedicle screw.

Bone formation after implantation of autolysed antigen extracted allogeneic bone in ovariectomized rabbits

This study was undertaken to evaluate the bone formation response to AAA bone in healthy and oestrogen deficient animals. Seventeen young healthy New Zealand female rabbits were used. Nine rabbits were subjected to ovariectomy and the remaining eight were sham-operated. Four weeks after ovariectomy standardized round cavities, 5mm in diameter, were made medially in the cortical part of each proximal tibia. To half of the cavities autolysed antigen-extracted allogeneic AAA bone granules were added. After another 8 weeks the animals were sacrificed and sections of the tibial experimental areas were obtained. These were studied in light microscopy and the bone and non-bone areas were measured with computer support. The study showed that the addition of a bone inductive substance such as AAA bone enhances bone formation also in oestrogen deficient animals.

The serotonin transporter promoter repeat length polymorphism, seasonal affective disorder and seasonality

BACKGROUND

Conflicting results have been reported in previous association studies of the serotonin transporter promoter repeat length polymorphism (5-HTTLPR), seasonal affective disorder (SAD) and seasonality (seasonal variations in mood and behaviour). The aim of this study was to test for association in new case-control and population-based materials, and to perform a combined analysis of all published studies of 5-HTTLPR and SAD.

METHOD

One hundred and forty-seven new SAD cases and 115 controls were genotyped for 5-HTTLPR and in total 464 patients and 414 controls were included in the pooled analysis. In addition, 226 individuals selected for unusually high or low seasonality scores from a population based material and 46 patients with non-seasonal depression were analysed. Different genetic models were tested and seasonality was analysed both as a qualitative (high v. low) and as a quantitative trait in the different sample sets.

RESULTS

No association between 5-HTTLPR and SAD was found in the new case-control material, in the combined analysis of all samples, or when only including 316 patients with controls (N = 298) selected for low seasonality. A difference was detected between the population based high and low seasonality groups, when assuming a recessive effect of the short allele (20% and 10% short allele homozygotes, respectively, OR (95% CI): 2.24 (1.03-4.91)). Quantitative analysis of seasonality revealed no association with 5-HTTLPR in any sample set.

CONCLUSIONS

These results do not suggest a major role of the short variant of 5-HTTLPR in susceptibility to SAD, but provide modest evidence for an effect on seasonality.

Atopy patch test reactions to Malassezia allergens differentiate subgroups of atopic dermatitis patients

BACKGROUND

The yeast Malassezia is considered to be one of the factors that can contribute to atopic dermatitis (AD).

OBJECTIVES

To investigate the reactivity to Malassezia allergens, measured as specific serum IgE, positive skin prick test and positive atopy patch test (APT), in adult patients with AD.

METHODS

In total, 132 adult patients with AD, 14 with seborrhoeic dermatitis (SD) and 33 healthy controls were investigated for their reactions to M. sympodialis extract and three recombinant Malassezia allergens (rMal s 1, rMal s 5 and rMal s 6).

RESULTS

Sixty-seven per cent of the AD patients, but only one of the SD patients and none of the healthy controls, showed a positive reaction to at least one of the Malassezia allergens (extract and/or recombinant allergens) in at least one of the tests. The levels of M. sympodialis-specific IgE in serum correlated with the total serum IgE levels. Elevated serum levels of M. sympodialis-specific IgE were found in 55% and positive APT reactions in 41% of the AD patients with head and neck dermatitis. A relatively high proportion of patients without head and neck dermatitis and patients with low total serum IgE levels had a positive APT for M. sympodialis, despite lower proportions of individuals with M. sympodialis-specific IgE among these groups of patients.

CONCLUSIONS

These results support that Malassezia can play a role in eliciting and maintaining eczema in patients with AD. The addition of an APT to the test battery used in this study reveals a previously overlooked impact of Malassezia hypersensitivity in certain subgroups of AD patients.

Titanium implants and BMP-7 in bone: an experimental model in the rabbit

This study evaluates the effect of rhBMP-7/OP-1 on the osseointegration of commercially pure titanium implants in an experimental implant model in rabbits. Threaded titanium implants with two transverse parallel canals were inserted in the femur and tibia of rabbits. The canals were filled with, 10 microg of BMP-7/collagen carrier, pure collagen carrier or were left empty as a control. The stiffness of the implant fixation was evaluated by Resonance Frequency Analysis (RFA) at baseline and four weeks postoperatively. Percentage of bone ingrowth in the canals was measured on microradiographs. Histomorphometry along the threaded part of the implants was performed on 15 microm thin sections. The results from the RFA demonstrated a higher mean value for the BMP-7 treated implants in the tibia than the carrier treated implants but not compared to the control implants. The control implants in the tibia demonstrated more bone ingrowth in the upper canal than to the carrier or the BMP-7 treated implants. Apart from these differences there were no significant effects of BMP. In this study BMP-7 did not contribute to any substantially improved bone anchorage of titanium implants.

Prevention of severe hypoglycaemia in type I diabetes: a randomised controlled population study

AIMS

To investigate use of targeted self study material in type I diabetes patient education regarding dissemination, perceived patient benefit, and prevention of severe hypoglycaemia.

METHODS

In a randomised 1:1:1 controlled study, 332 patients with type I diabetes (aged 2.6-18.9 years) were studied; 313 completed clinical follow up, 261 completed endpoint questionnaire. The intervention group received videotapes and a brochure designed to review skills for self control and treatment, aimed at preventing severe hypoglycaemia. Two control groups received a videotape and brochure with general diabetes information, or traditional treatment only, respectively.

RESULTS

Yearly incidence of severe hypoglycaemia decreased from 42% to 27% in the intervention group, but not in controls. HbA1c remained unchanged. Levels of use ranged from 1 to 20 times (median 2); 40-49% had shown the materials to friends, relatives, school staff, sports coaches, etc (there was little difference between intervention and control groups). Higher benefit and learning levels resulted from the intervention material, especially in patients with severe hypoglycaemia.

CONCLUSIONS

Mass distributed pedagogical devices such as high quality video programmes and brochures may contribute to the prevention of severe hypoglycaemia. Such self study materials can reach high dissemination levels and constitute a cost effective complement to regular visits to a diabetes team and to other types of education. The findings may have implications for other topics, other ages, and other diagnosis groups.

Improved bone-screw interface with hydroxyapatite coating: an in vivo study of loaded pedicle screws in sheep

STUDY DESIGN

An in vivo sheep model with loaded pedicle screws was used, wherein each animal served as its own control.

OBJECTIVES

To examine the effects of hydroxyapatite (HA) coating on the bone-to-implant interface in loaded spinal instrumentations.

SUMMARY OF BACKGROUND DATA

Spinal instrumentation improves the healing rate in spinal fusion, but screw loosening constitutes a problem. HA coating of other implants has resulted in favorable effects on the bone-to-implant interface.

METHODS

Nine sheep were operated on with destabilizing laminectomies at two levels: L2-L3 and L4-L5. Each level was stabilized separately with a four-screw instrumentation. Uncoated screws (stainless steel) or the same type of screws coated with plasma-sprayed HA were used in either the upper or the lower instrumentation in a randomized fashion. The animals were killed at 6 or 12 weeks after surgery. The specimens were embedded in resin, ground to approximately 10 microm, and stained with toluidine blue. Histomorphometric evaluation was carried out in a Leitz Aristoplan (Wetzlar, Germany) light microscope equipped with a Leitz Microvid unit.

RESULTS

The average percentage of bone-to-implant contact after 6 weeks was 69 +/- 10 for the HA-coated screws and 18 +/- 11 for the uncoated screws (P < 0.03), and after 12 weeks 64 +/- 31 (HA-coated) and 9 +/- 13 (uncoated, P < 0.02). The average bone volume in the area close to the screw was significantly higher for the HA-coated screws at both 6 and 12 weeks.

CONCLUSIONS

HA coating improved the bone-to-implant interface significantly, indicating that HA coating can become useful for improving the purchase of pedicle screws.

Ablation of TRalpha2 and a concomitant overexpression of alpha1 yields a mixed hypo- and hyperthyroid phenotype in mice

Thyroid hormone governs a diverse repertoire of physiological functions through receptors encoded in the receptor genes alpha and beta, which each generate variant proteins. In mammals, the alpha gene generates, in addition to the normal receptor TRalpha1, a non-hormone-binding variant TRalpha2 whose exact function is unclear. Here, we present the phenotype associated with the targeted ablation of TRalpha2 expression. Selective ablation of TRalpha2 resulted in an inevitable, concomitant overexpression of TRalpha1. Both TRalpha2 +/- and -/- mice show a complex phenotype with low levels of free T3 and free T4, and have inappropriately normal levels of TSH. The thyroid glands exhibit mild morphological signs of dysfunction and respond poorly to TSH, suggesting that the genetic changes affect the ability of the gland to release thyroid hormones. However, the phenotype of the mutant mice also has features of hyperthyroidism, including decreased body weight, elevated heart rate, and a raised body temperature. Furthermore, TRalpha2-/- and TRalpha2+/- mice are obese and exhibit skeletal alterations, associated with a late-onset growth retardation. The results thus suggest that the overexpression of TRalpha1 and the concomitant decrease in TRalpha2 expression lead to a mixed hyper- and hypothyroid phenotype, dependent on the tissue studied. The phenotypes suggest that the balance of TRalpha1:TRalpha2 expressed from the TRalpha gene provides an additional level of tuning the control of growth and homeostasis in mammalian species.

T cell responses to recombinant isoforms, synthetic peptides and a mutant variant of Lep d 2, a major allergen from the dust mite Lepidoglyphus destructor

BACKGROUND

The dust mite Lepidoglyphus destructor is an important cause of allergic reactions to dust, especially in farming environments. Two isoforms, recombinant (r)Lep d 2.01 and rLep d 2.02, of the major allergen Lep d 2, have previously been expressed as recombinant proteins. These isoforms differ 10.4% at the amino acid level. Furthermore, a mutant form of Lep d 2.01 (rLep d 2.6Cys) with a highly reduced IgE reactivity, has also been produced.

OBJECTIVE

To investigate the T cell responses to the recombinant isoforms of Lep d 2, the Lep d 2.6Cys mutant and peptides of Lep d 2, in allergic and non-allergic individuals.

METHODS

Peripheral blood mononuclear cells from 18 allergic and 16 non-allergic individuals were stimulated with the different antigens and the proliferative responses were measured. The cytokine production (interleukin (IL)-4, IL-5 and interferon (IFN)-gamma) were measured by ELISA.

RESULTS

Higher T cell proliferation was measured to isoform 01 than to 02 in 28/34 subjects. The responses to rLep d 2.6Cys were lower than to isoform 01 in most subjects, but higher than to Lep d 2.02. Two immuno-dominant peptides, corresponding to amino acid residue 11-25 and 61-75 were identified. The atopic subjects produced significantly lower IFN-gamma in response to Lep d 2.01 as compared to the non-atopics.

CONCLUSIONS

There was a significant difference in T cell response between the two isoforms of rLep d 2. The hypoallergenic mutant rLep d 2.6Cys was able to evoke a T cell response with a magnitude which is between the two isoforms. Amino acid residue 11-25 and 61-75 are the most frequently recognized parts of Lep d 2 and are likely to contain the immuno-dominant T cell epitopes.

Genetics of affective disorders

Despite substantial evidence for heritability in affective disorders the contributing genes have proven elusive. Here we discuss the genetic epidemiology of depression, as well as methodological issues and results from molecular genetic studies. There has been rapid advances in genetics, genomics and statistical modelling, facilitating the search for molecular mechanisms underlying affective disorders and several strategies reviewed in this paper hold promise to provide progress in the field. Considering the poorly understood biological basis of vulnerability to affective disorders, the identification of genes involved in the pathophysiology will unravel mechanisms and pathways that could permit more personalized therapeutic strategies and result in new targets for pharmacological intervention.

Synthesis and structure elucidation of some new thioether derivatives of 1,2,4-triazoline-3-thiones and their antimicrobial activities

5-(4-Pyridinyl)-4-substituted-2.4-dihydro-3H-1,2,4-triazole-3-thiones and 5-(4-pyridinyl)-4-substituted-3-(benzoylmethyl)thio-4H-1,2,4-triazoles were synthesized. The structures of original nine compounds were confirmed by IR, 'H NMR, mass spectral methods and elemental analysis. The antibacterial, antifungal and antimycobacterial activities, together with those of known intermediate 1,4-disubstituted thiosemicarbazides, were reported.

Osteoinduction, osteoconduction and osseointegration

Osteoinduction is the process by which osteogenesis is induced. It is a phenomenon regularly seen in any type of bone healing process. Osteoinduction implies the recruitment of immature cells and the stimulation of these cells to develop into preosteoblasts. In a bone healing situation such as a fracture, the majority of bone healing is dependent on osteoinduction. Osteoconduction means that bone grows on a surface. This phenomenon is regularly seen in the case of bone implants. Implant materials of low biocompatibility such as copper, silver and bone cement shows little or no osteoconduction. Osseointegration is the stable anchorage of an implant achieved by direct bone-to-implant contact. In craniofacial implantology, this mode of anchorage is the only one for which high success rates have been reported. Osseointegration is possible in other parts of the body, but its importance for the anchorage of major arthroplasties is under debate. Ingrowth of bone in a porous-coated prosthesis may or may not represent osseointegration.

Growth of costochondral grafts in reconstruction of the mandibular condyle: an experimental study in domestic pigs

Reconstruction of the mandibular condyle with costochondral grafts (CCGs) in children may result in overgrowth at the reconstructed side of the mandible. In this study we report on the effects of functional stimuli on growth and morphology of growth plates of CCGs used for immediate mandibular condyle replacement in 10 juvenile pigs. The mandibular condyles were resected unilaterally and immediately reconstructed with autogenous CCGs. Another CCG was placed submuscularly on one tibia. The lengths of both CCGs and of one rib before resection were measured at operation and 12 weeks later. The grafts were labelled with intraperitoneal injections of oxytetracycline and alizarin eight and 12 weeks postoperatively, respectively. The extent of growth of the CCGs in the two environments was similar, so we concluded that the functional stimuli in the TMJ environment had only a minor influence on the extent of growth of the CCGs. The morphology of the growth plate of the CCGs had changed considerably.

Revascularisation of costochondral grafts: an experimental study in domestic pigs

Mandibular condyles are reconstructed immediately with costochondral grafts (CCGs) in children for several temporomandibular conditions, including ankylosis, benign neoplasia, and chronic arthritis. A prerequisite for growth of CCGs is that they are properly revascularised, but the revascularisation process has not to our knowledge so far been examined. The aim of the present study was therefore to investigate the revascularisation of CCGs when they were used for immediate reconstruction of the mandibular condyle in juvenile domestic pigs. Eleven mandibular condyles were experimentally resected and immediately reconstructed with CCGs. Microangiograms with an Indian ink solution were done 2, 4, 8, and 12 weeks after the reconstructions. The density of vessels was higher in measurement zones facing soft tissues than in those facing mandibular bone at all time points. Revascularisation of the growth plate originated from the surrounding recipient soft tissues and not from an endosteal blood supply from the host mandible ramus.

Altered dopaminergic transmission in the anorexic anx/anx mouse striatum

We demonstrate abnormal dopaminergic neurotransmission in anorexic mice, homozygous for a recessive mutation (anx) causing starvation and motor disturbances. Isolated neurons from anx/anx striatum displayed a markedly increased activity of the Na+,K+-ATPase compared with normal littermates. Dopamine down-regulates Na+,K+-ATPase activity in striatal medium spiny neurons in rat, mouse and guinea pig. However, addition of dopamine in vitro failed to suppress the increased activity in anx/anx striatal neurons. Striatal dopamine and its metabolites, but not norepinephrine, were slightly but significantly lower in anx/anx mice than in normal littermates. We suggest that abnormal dopaminergic transmission may contribute to the anx phenotype.

Photopheresis at onset of type 1 diabetes: a randomised, double blind, placebo controlled trial

BACKGROUND

In recent years photopheresis, an extracorporeal form of photochemotherapy using psoralen and ultraviolet A irradiation of leucocytes, has been claimed to be an effective form of immunomodulation.

AIM

To evaluate its effect in type 1 diabetes we performed a double blind, controlled study using placebo tablets and sham pheresis in the control group.

METHODS

A total of 49 children, aged 10-18 years of age at diagnosis of type 1 diabetes were included; 40 fulfilled the study and were followed for three years (19 received active treatment with photopheresis and 21 placebo treatment).

RESULTS

The actively treated children secreted significantly more C peptide in urine during follow up than control children. C peptide values in serum showed corresponding differences between the two groups. The insulin dose/kg body weight needed to achieve satisfactory HbA1c values was always lower in the photopheresis group; there was no difference between the groups regarding HbA1c values during follow up. The treatment was well accepted except for nausea (n = 3) and urticaria (n = 1) in the actively treated group. There were no differences regarding weight or height, or episodes of infection between the two groups during follow up.

CONCLUSION

Photopheresis does have an effect in addition to its possible placebo effect, shown as a weak but significant effect on the disease process at the onset of type 1 diabetes, an effect still noted after three years of follow up.

Salmonella typhimurium-induced cytokine production and surface molecule expression by murine macrophages

The influence of Salmonella enterica serovar Typhimurium (S. typhimurium) on co-stimulatory molecule expression, cytokine production and induction of nitric oxide synthase (iNOS) by murine macrophages (Mphi), as well as the influence of the phoP locus on these aspects of S. typhimurium-Mphi interaction, was characterized. Pulsing Mphi with S. typhimurium resulted in increased surface expression of MHC-I, MHC-II, CD86 and CD54. Furthermore, co-incubating S. typhimurium with Mphi resulted in interleukin (IL)-12p40, IL-6 and tumor necrosis factor-alpha production as well as iNOS induction while IL-12p70 was not detectable. Finally, although phoP did not influence the level of surface molecule expression or cytokine production by S. typhimurium-pulsed Mphi phoP did influence the level of iNOS induction. Together these data show that S. typhimurium interaction with Mphi activates these cells in ways that may enhance their ability to productively stimulate Salmonella-specific T cells following phagocytic processing and presentation of Salmonella antigens.