The action of interleukin 6 and leukaemia inhibitory factor on liver cells

The hepatic action of cytokines has generally been analysed in terms of the acute-phase response of the liver. The qualitative and quantitative changes in the expression of plasma proteins serve as defining criteria for cytokine function. Interleukin 6 (IL-6) and leukaemia inhibitory factor (LIF) are representatives of a group of cytokines which display strikingly similar effects in both human and rodent liver cells. Hallmarks of the action of these cytokines are the stimulation of type 2 acute-phase plasma proteins and enhancement of the effect of interleukin 1 (IL-1) or tumour necrosis factor alpha (TNF-alpha) on type 1 acute-phase plasma proteins. The transcriptional activation of the various acute-phase plasma protein genes involves common cis-acting regulatory elements whose sequences and location relative to the transcription start site vary from gene to gene. The activity of the IL-6- and LIF-responsive genes depends in part on transcription factors including several members of the C/EBP family, JunB and the glucocorticoid receptor. The expression of these transcription factors is in turn under cytokine-specific control. In a few cases, expression is temporally correlated with the activation of 'late' acute-phase protein genes. The finding that structurally distinct cytokines interact with separate receptors but elicit an almost identical liver cell response demands a reassessment of the contribution of each factor to the in vivo acute-phase response.

[Intended and actual paths of epidural needles. Investigations with a test tissue model]

Peridural anaesthesia needles (PDA) do not only differ in calibre or gauge but also vary in the design of the needle tip, which shows a special configuration to place a catheter in the epidural space. A laboratory model was performed to determine the influence of different types of virgin epidural needles concerning their path through tissue. In an additional test run we analysed the influence of a previous use on the path through tissue. We investigated 16 G and 18 G Tuohy needles for epidural anaesthesia and two different 18 G Tuohy needles for combined spinal-epidural anaesthesia. The experiments were performed in a standardised way using a precision drill press in order to make the test independent of the investigator. The test tissue was selected because of its close similarity to human tissue of the lumbar region. Every needle tested revealed a distinct deviation even after a 6 cm passage through the test tissue and regularly deviated away from the concave side of the needle tip. The comparison of the CSE needles tested revealed a significant deviation from the axis due to differences in cross-section and configuration of the needle tip. As expected, the average deviation of PDA needles depended on the diameter. No differences in the degree of deviation for virgin needles compared to previously used needles could be found. Thus, more than one application of the same needle in one patient is considered to be safe as long as the needle is not deformed in any way.

Effect of exercise, body composition, and nutritional intake on bone parameters in male elite rock climbers

A low body mass index is considered essential for high performance in rock climbing; however its effect on bone may be negative. In this study we compared the BMD of competitive male rock climbers (n = 20) and age- and BMI-matched non-training controls (n = 11). Subjects with any medication or illness affecting bone metabolism or a family history of osteoporosis were not included in the analysis. Total body BMD was measured by dual-energy X-ray absorptiometry. Quantitative computed tomographic scans were made from the femoral neck and the lumbar spine. Dietary intake was assessed by a 5-day protocol. BMD of the TB-scan was significantly higher in the climbers group for all sub-regions except the skull (p = 0.191) and the lower extremities (p = 0.079). Trabecular and cortical BMD of the LS were significantly higher (p = 0.036 and p = 0.004) in the climbers. The same was true for total (p = 0.005) and cortical (p = 0.002) BMD of the FN. Trabecular BMD (p = 0.054), CSA (p < 0.343) and cortical thickness (p = 0.065) of the FN was non-significantly higher for the climbers. Our study indicates that the effect of climbing on bone parameters PER SE is not detrimental in elite male athletes. Contrarily climbers demonstrated significantly higher BMD values at all loaded regions without "steal effects" at skeletal sites with low mechanical impact. Although we determined a moderately negative effect of low BMI on BMD we could not decide whether a low BMI value should be used as an exclusion criterion in high level climbing competitions as practized by the Austrian Sportclimbing Organization.

Impact of disease activity on thyroid diseases in patients with acromegaly: basal evaluation and follow-up

In patients with acromegaly, the exact incidence of thyroid disorders is still controversial and less is known about the impact of disease activity and successful treatment. To address this issue, we investigated 73 acromegalic patients (age 55 +/- 13 yr; mean +/- SD) by ultrasonography in comparison to an age-matched control group (54 +/- 1 yr) in the same moderate iodine deficient area (retrospective study). These non-acromegalic volunteers (n = 199) were examined in the same clinic during a thyroid screening test. At the time of examination, 52 (71.2 %) of the acromegalic patients were active, 17 (23.3 %) were cured, and 4 (5.5 %) were controlled with somatostatin analogues. The prevalence of goiter (normal range < 18 ml female, < 25 ml male) was significantly higher (82.2 %) in the mixed group of acromegalics (active, well controlled, cured; n = 73) and in the active group (90.4 %) than in the control group (n = 199, 18.1 %, p < 0.001). Thyroid nodules were found in 63.0 % of the mixed group of acromegalics and in 71.2 % of patients with active disease (33.1 % in controls, p < 0.001). (99 m)Tc scintigraphy revealed thyroid autonomy in 9/73 (12.3 %) and cold nodules in 19/73 (26.0 %) patients. Thyroid cancer was diagnosed in 4 (5.5 %) of acromegalic patients (3 papillary and 1 follicular carcinoma). We found a weak correlation between the disease duration and the initial thyroid volume (r = 0.54, p < 0.0056). Thirty-seven newly diagnosed acromegalics were followed over a period of 7.3 +/- 4.1 years. 5 (13.5 %) of these patients remained active, 8 (21.6 %) were controlled with somatostatin analogues, and 24 (64.9 %) were cured. The mean age, sex distribution, disease duration, prevalence of TSH-deficiency, and initial thyroid volume (46 +/- 11 ml in active, 42 +/- 7 ml in controlled, and 45 +/- 5 ml in cured patients) did not differ statistically between the three groups. In patients with active acromegaly, thyroid volume increased by 19.5 +/- 8.1 %. In contrast, thyroid volume decreased in the group of medically controlled and cured acromegalics (- 21.5 +/- 7.1 %; p < 0.005 and - 24.2 +/- 5.7 %; p < 0.002, respectively). No correlation was found between thyroid volume and TSH levels, levothyroxine and/or iodide administration neither in TSH sufficient nor in TSH insufficient patients. In conclusion, successful treatment of patients with active acromegaly decreases thyroid volume. Cold nodules and thyroid cancer frequently occur in acromegalic patients.

Role of cytokines in photodynamic therapy-induced local and systemic inflammation

Photodynamic therapy (PDT) of tumour results in the rapid induction of an inflammatory response that is considered important for the activation of antitumour immunity, but may be detrimental if excessive. The response is characterised by the infiltration of leucocytes, predominantly neutrophils, into the treated tumour. Several preclinical studies have suggested that suppression of long-term tumour growth following PDT using Photofrin((R)) is dependent upon the presence of neutrophils. The inflammatory pathways leading to the PDT-induced neutrophil migration into the treated tumour are unknown. In the following study, we examined, in mice, the ability of PDT using the second-generation photosensitiser 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (HPPH) to induce proinflammatory cytokines and chemokines, as well as adhesion molecules, known to be involved in neutrophil migration. We also examined the role that these mediators play in PDT-induced neutrophil migration. Our studies show that HPPH-PDT induced neutrophil migration into the treated tumour, which was associated with a transient, local increase in the expression of the chemokines macrophage inflammatory protein (MIP)-2 and KC. A similar increase was detected in functional expression of adhesion molecules, that is, E-selectin and intracellular adhesion molecule (ICAM)-1, and both local and systemic expression of interleukin (IL)-6 was detected. The kinetics of neutrophil immigration mirrored those observed for the enhanced production of chemokines, IL-6 and adhesion molecules. Subsequent studies showed that PDT-induced neutrophil recruitment is dependent upon the presence of MIP-2 and E-selectin, but not on IL-6 or KC. These results demonstrate a PDT-induced inflammatory response similar to, but less severe than obtained with Photofrin((R)) PDT. They also lay the mechanistic groundwork for further ongoing studies that attempt to optimise PDT through the modulation of the critical inflammatory mediators.

Haptoglobin directly affects T cells and suppresses T helper cell type 2 cytokine release

T helper cell type 1 (Th1) and type 2 (Th2) immune responses are characterized by a different pattern of cytokine expression following T-cell activation. Alterations of the ratio of Th1 to Th2 cells are important determinants of susceptibility to viral and parasitic infections, allergies, anti-tumour responses, and autoimmunity. In this work we bring new evidence for an effect of haptoglobin (Hp), a positive acute-phase protein, on T-lymphocyte functions. We show that Hp specifically interacts with both resting and activated CD4+ and CD8+ T cells. This specific binding results in a strong suppression of induced T-cell proliferation. In addition, Hp exhibits a strong in vitro inhibitory effect on Th2 cytokine release, while the production of interferon-gamma (IFN-gamma) and interleukin-2 (IL-2) is only slightly inhibited at high Hp doses. As a result, the presence of Hp promotes Th1 activation over Th2 activation in vivo as evidenced in Hp-deficient mice. Anti-CD3 monoclonal antibody injection indeed resulted in predominant IL-4 production in Hp-/- mice, in contrast to predominant IFN-gamma production in Hp+/+ mice. We conclude that Hp plays a modulating role on the Th1/Th2 balance by promoting a dominant Th1 cellular response. This points to a role of acute-phase proteins in balancing immune responses.

Diffusion studies in non-oxide ceramics: analytical aspects of the use of ion implanted stable tracers and SIMS

The physical and chemical properties of complex non-oxide ceramic materials require advanced methods of diffusivity determination. In this study, we present a method based on the high-dose ion implantation of stable tracers in combination with secondary ion mass spectroscopy for depth profiling. The analytical basics, advantages and problems of the method are discussed for two examples of complex materials, the Si-B-C-N precursor ceramics and the Ti-based transition metal diborides. We demonstrate that is possible to measure the temperature dependence of diffusivities, especially for ceramic systems with low diffusivities, for systems that contain elements for which no suitable radioactive tracers exist for extended measurements.

Overexpression of alpha(1)-acid glycoprotein in transgenic mice leads to sensitisation to acute colitis

BACKGROUND

alpha(1)-Acid glycoprotein (alpha(1)-AGP) is an acute phase protein in most mammalian species whose concentration rises 2-5-fold during an acute phase reaction. Its serum concentration has often been used as a marker of disease, including inflammatory bowel disease (IBD). High alpha(1)-AGP levels were found to have a prognostic value for an increased risk of relapse in IBD.

AIMS

To investigate a possible role for increased serum levels of alpha(1)-AGP in the development of IBD.

METHODS

Dextran sodium sulphate (DSS) 2% was added to the drinking water of transgenic mice, overexpressing the rat alpha(1)-AGP gene, to induce acute colitis, thus mimicking the conditions of relapse. Clinical parameters, inflammatory parameters, and histological analyses on colon sections were performed.

RESULTS

Homozygous alpha(1)-AGP-transgenic mice started losing weight and showed rectal bleeding significantly earlier than heterozygous transgenic or wild-type mice. Survival time of homozygous transgenic mice was significantly shorter compared with heterozygous and wild-type mice. The higher susceptibility of homozygous alpha(1)-AGP-transgenic mice to DSS induced acute colitis was also reflected in higher local myeloperoxidase levels, higher inflammation scores of the colon, and higher systemic levels of interleukin 6 and serum amyloid P component. Local inflammatory parameters were also significantly different in heterozygous transgenic mice compared with wild-type mice, indicating a local dosage effect. In homozygous transgenic mice, significantly higher amounts of bacteria were found in organs but IgA levels were only slightly lower than those of control mice.

CONCLUSION

Sufficiently high serum levels of alpha(1)-AGP result in a more aggressive development of acute colitis.

Haptoglobin, an inflammation-inducible plasma protein

Sterile tissue injury or infection initiates a local inflammatory response that mobilizes a systemic acute phase reaction resulting in, among other things, the induction of genes encoding the acute phase plasma proteins (APPs). In all vertebrates, a common set of APPs is increased and exerts essential protective functions. Haptoglobin (HP), one of the major APPs, acts as a high-affinity hemoglobin-binding protein and antioxidant. Liver is the major site of HP synthesis; however, regulated, low level expression is also detected in other organs. Induction of the Hp gene is mediated by interleukin-6-type cytokines and is synergistically enhanced by glucocorticoids. Growth stimulation of hepatic cells in vivo or in vitro suppresses the Hp gene-inducing effects of inflammatory cytokines. Receptors for IL-6 cytokines mediate induction of the Hp gene by the transcription factors signal transducer and activator of transcription-3 (STAT3) and CAAT/enhancer binding protein beta (C/EBPbeta), but attenuate the stimulation through co-activated STAT5 and mitogen-activated protein kinases, ERK-1 and ERK-2. The specificity by which the related cytokines, IL-6, oncostatin M, and leukemia inhibitory factor, regulate Hp gene transcription is determined by the profile of the cytokine receptor subunits expressed on the target cells and the relative extents by which these receptors activate the intracellular signaling pathways. The current hypothesis is that HP exerts an anti-inflammatory activity and that by the degree with which HP attenuates the inflammatory process, including the production of IL-6 cytokines, it determines the level and duration of acute phase expression of the Hp gene.

Haptoglobin, inflammation, and tumorigenesis in the MIN mouse

We have determined that the MIN mouse, which is predisposed to adenomas of the small and large intestine, exhibits chronic inflammation characterized by the induction of haptoglobin (HP), as well as other acute phase proteins. Inflammation is initiated at about 40-70 days of age, and is maintained throughout the life of the animal. Delayed onset of inflammation brought on by dietary means is associated with a reduction in tumor number and longer life-span. Knockout mice that lack haptoglobin exhibit an increase in tumor number, indicating that the acute phase reactant suppresses tumorigenesis, perhaps through inhibition of the inflammatory response. The MIN mouse is, therefore, a useful model for studying the roles of HP and inflammation in tumorigenesis in vivo.

Haptoglobin and the Th1/Th2 balance: hints from in vitro and in vivo studies

A variety of immunomodulatory effects have previously been attributed to haptoglobin (Hp). These are supposed to be partly mediated through binding of Hp to CD11b. In the present study, we assessed its effects on T-helper (Th) cytokine production following both in vitro and in vivo stimulation of T-cells. Hp exhibits a dose-dependent inhibitory effect on human T lymphocyte release of the Th2 cytokines (IL-4, IL-5, IL-10 and IL-13) in vitro, whereas it has no clear effect on Th1 cytokine (IL-2 and IFN-gamma) release. When administered an anti-CD3 monoclonal antibody, Hp knockout mice produced more IL-4 and less IFN-gamma than did their wild-type litter-mates. Our findings imply that Hp may be regarded as a regulator of the Th1/Th2 balance in both human and murine immune systems.

Phylogeny and geographical differentiation of zucchini yellow mosaic virus isolates (Potyviridae) based on molecular analysis of the coat protein and part of the cytoplasmic inclusion protein genes

DNA sequences for the coat protein (CP) and part of the cytoplasmic inclusion (CI) protein genes after reverse transcriptase-polymerase chain reaction (RT-PCR) were reported for the first time for isolates of zucchini yellow mosaic virus (ZYMV) from Austria, Germany, Italy and Slovenia. Comparison of the DNA sequences of 30 isolates from different geographical regions worldwide revealed highest similarities of the Austrian isolates to those from Slovenia and Hungary. Isolates from Germany and Italy were only distantly related and clustered with isolates from other parts of the world. Our results indicate that a specific isolate can spread rapidly to geographically adjacent areas but may not be directly related to isolates found in other neighboring countries.