Myocardial perfusion after one year of spinal cord stimulation in patients with refractory angina

Aim: Spinal cord stimulation (SCS) is recommended for patients with coronary artery disease (CAD) and refractory angina. We used positron emission tomography (PET) to investigate the long-term effect of SCS on regional myocardial perfusion in patients suffering from angina pectoris refractory to medical treatment and without option for coronary intervention. Patients, methods: We analyzed data of 44 patients with stable CAD (91% three vessel disease). At baseline, we determined coronary flow reserve (CFR) using 13N-ammonia-PET and myocardial viability with 18F-FDG. SCS was performed for one year (Medtronic Itrell III or Synergy, Düsseldorf, Germany). During follow-up, no cardiac interventions were necessary and no myocardial infarctions occurred. At one year follow-up, CFR was measured again. Results: In the majority of patients (77%), SCS led to an improvement of clinical symptoms. CFR did not change significantly during follow-up. Subjective improvement did not correlate with an increase of CFR. Conclusions: Despite its clinical effect, SCS does not have a direct impact on CFR in patients with stable CAD. According to our results, the pain relief is not due to an improvement of the myocardial blood supply.

Myocardial sympathetic innervation in diabetic patients with symptomatic coronary artery disease

Aim: In non-diabetic patients, sympathetic innervation can be preserved even if there is major impairment of myocardial blood supply. Matters may be more complex in diabetic patients because denervation can be caused by cardiac autonomic neuropathy (CAN) or by ischemic injury. Our aim was to determine whether restrictions in myocardial blood supply have a pronounced influence on sympathetic innervation in diabetics and if this effect can be differentiated from CAN. Patients, methods: We analyzed 20 diabetics with advanced coronary artery disease (CAD) and without known CAN. We determined quantitative myocardial blood flow using 13N-ammonia-PET, myocardial viability with 18F-FDG, and cardiac innervation with 11C-HED. We investigated the relationship between regional HED retention, blood flow, and coronary flow reserve (CFR). Attenuated heart rate response to adenosine was taken as indicator for CAN (HR ratio). Results: There was minor correlation of segmental stress flow and HED retention (r2 = 0.063, p <0.0001). Correlation improved when stress flow as well as HED retention were normalized to the individual maximum (r2 = 0.162, p <0.0001). In nine patients, a HR ratio < 1.2 implicated subclinical CAN. Duration of diabetic disease or glycaemic control (HbA1c) did not correlate with mean HED retention in the viable segments, but with its variation coefficient. Conclusions: As in non-diabetic patients, a slight correlation exists between CFR and sympathetic innervation. The sensitivity of sympathetic nerves to reductions in CFR does not seem to be increased as compared to the results reported for non-diabetics. Besides impaired blood supply, long duration of diabetic disease and bad glycaemic control also seem to impair sympathetic innervation provoking higher heterogeneity.

[Exercise training in the therapy of heart diseases: Current evidence and future options]

Exercise training has been firmly established as an additional therapeutic strategy in addition to pharmacological and interventional treatment in patients with cardiovascular disease. Benefits for quality of life as well as prognosis have been confirmed for cardiovascular risk factors, ischemic heart disease, after myocardial infarction, in heart failure with preserved as well as reduced ejection fraction, in atrial fibrillation and in patients after catheter-assisted aortic valve implantation (TAVI), with an implantable cardioverter defibrillator (ICD) or with left ventricular assist devices (VAD). Training programs have to be tailored according to the disease, stage of disease, comorbidities, age of the patient, medication as well as exercise capacity. For prescribing exercise mode and intensity, a maximum exercise test has to be performed. Ideally, this is accompanied by spirometry to assess maximum values such as maximum oxygen consumption. Training intensity will then be prescribed according to the optimal training range and maximum training intensity.

Sentinel Lymph Node Biopsy in Patients with Breast Cancer: Comparison of Peritumoral and Periareolar Injection

Introduction: Intradermal periareolar injection technique for sentinel lymph node biopsy (SLNB) may offer an advantage by including multifocal breast cancer as an additional indication. In May 2008 we changed our standard procedure from peritumoral (PT) to periareolar (PA) injection. We compared the results for corresponding periods before and after the change in procedure. Material and Method: A total of 117 patients (pts.) were investigated the year after we changed our technique; a total of 152 pts were investigated in the reference period 2007. We investigated the identification rates for sentinel lymph nodes (SLN) identified scintigraphically and surgically as well as the rates of metastatic involvement (LN). Results: After PT injection, scintigraphic detection of SLN failed in 5/152 pts., and in a further 10 pts. SLN was not found at surgery. In 7 of 15 pts. in whom SLN was not detected, histology demonstrated nodal involvement. Metastases were found in the SLN of 28 of 137 pts. with successful detection of SLN; no other lymph nodes were affected in 21 of these pts. (75.0 % of pts. with positive SLN detection). With PA injection at least one SLN could always be detected using scintigraphy; only 2/117 SLN could not be found intraoperatively. Metastasis was found in SLN in 34/115 pts.; in 19/34 pts., metastatic involvement was limited to the SLN with no other lymph nodes involved (55.9 % of pts. with positive detection of SLN). Discussion: The detection rate for SLN was significantly higher using PA injection (98.3 % vs. 90.1 %). As axillary dissection was not done in SLN-negative patients, rates of false-negative detection cannot be determined. PA injection not only results in better detection rates, it also offers the advantage that the technique can be performed correctly regardless of tumour localisation.

Association of a common genetic variant of the IGF1 gene with clinical outcome in patients with HER2-positive breast cancer

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Background: Insulin-like growth factor 1 (IGF1) stimulates mitosis and inhibits apoptosis. Circulating IGF1 levels may be linked with an increased risk of colorectal and breast cancer. Further, IGF1 single nucleotide polymorphisms (SNPs), especially variant rs2946834, recently have been associated with a poor clinical outcome in patients with colorectal cancer. However, the influence of IGF1 SNPs on the prognosis of patients with breast cancer is unknown. Therefore, we aimed at investigating the influence of IGF1 tagging polymorphisms associated with IGF1 levels on event-free survival in patients with HER2-positive breast cancer.

Methods: The present study included 161 consecutive white patients with HER2-positive breast cancer treated between 2000 and 2010 at the Department of Gynecology and Obstetrics, Medical University of Innsbruck, Austria. Event-free survival was calculated as the time from cancer diagnosis to either relapse or death from any cause. Genomic DNA was extracted from archived formalin-fixed paraffin embedded tumor tissue samples; five IGF1 tagging polymorphisms (rs2946834, rs6220, rs1520220, rs5742694, and rs5742678) were genotyped by SNaPshot assays.

Results: Mean follow up period was 4.3 (± 2.5) years. Kaplan-Meier analysis showed a poorer clinical outcome for carriers of the rare allele of SNP rs2946834 (log-rank test, p = 0.029). Concordantly, in univariate Cox regression analyses the rare allele of SNP rs2946834 was significantly associated with a decreased event-free survival (HR = 2.87 [1.07 –7.70]; p = 0.036). Multivariate analysis adjusted for age and tumor stage confirmed this result (HR = 2.86 [1.06 –7.71]; p = 0.038). Thus, our results are in concordance with a recent report that the same SNP is associated with poorer clinical outcome in colorectal cancer patients. Other investigated genetic variants of the IGF1 gene were not significantly associated with event-free survival (all p-values > 0.05).

Conclusions: For the first time, our study investigates the influence of IGF1 tagging polymorphisms on the clinical outcome of HER2-positive breast cancer patients suggesting SNP rs2946834 as a predictor for reduced event-free survival.

Clogging of microchannels by nano-particles due to hetero-coagulation in elongational flow

We have investigated the phenomenon of flow-induced aggregation in highly concentrated colloidal dispersions exposed to strongly converging flow fields. This phenomenon is relevant not only for classical technical operations like coating, pumping or filtration, but also for the application of concentrated suspensions in upcoming processing technologies based on microfluidic devices. A ring-slit device (gap height 10-25 μm), which allows for a variation of flow kinematics in a wide range, has been developed in order to investigate this phenomenon. Various polymer dispersions with different particle surface properties have been used as model systems. Our experiments exclude, that channel clogging is due to retention of pre-existing aggregates, fouling or hydrodynamic bridging. Instead, we demonstrate that clogging of the microchannel is induced by hetero-coagulation between primary colloidal particles and micron-sized impurities present at concentrations on the order of 100-1000 ppm. Clogging can occur even if the diameter of these impurities is less than a tenth of the gap height. Aggregation takes place in the converging flow field at the channel entrance, but not in the shear field within the slit. It can be suppressed by appropriate stabilization of the primary particles.

THE ELECTRIC IMPEDANCE OF HEMOLYZED SUSPENSIONS OF MAMMALIAN ERYTHROCYTES

This paper is concerned with the changes in the electric surface capacity and surface resistivity of the membrane surrounding the mammalian red corpuscle, as a result of various types of hemolysis. In the case of hemolysis with water, the cells swell with no apparent change in the electric properties of the membrane. They then hemolyze, but the membrane persists, although showing evidence of injury, as indicated by a change in the frequency dependence of its capacity and resistivity at low frequencies. The fact that a change of the frequency dependence takes place shows that the injury cannot be due merely to a rupture in the membrane, but must be due to changes in the properties (increased permeability) of the membrane as a whole. With chemical lysins (saponin, complement and amboceptor, digitonin, sodium taurocholate) a similar type of injury to the membranes of a certain number of the corpuscles takes place, to an increasing extent as the concentration of lysin is increased. The rest of the corpuscles become completely permeable to the electric current, and as the amount of lysin is increased, this number of completely permeable corpuscles increases until all are affected. This change, presumably associated with a disintegration of the corpuscle membrane, is referred to as stromatolysis, and the method gives a quantitative means of determining percentage stromatolysis. For lysis by freezing and thawing, the results obtained indicate this type of lysis to be different from that of the others studied.

THE ELECTRIC CAPACITY OF SUSPENSIONS WITH SPECIAL REFERENCE TO BLOOD

1. The specific capacity of a suspension is that capacity which) combined in parallel with a certain resistance, electrically balances 1 cm. cube of the suspension. 2. The following formula holds for the specific capacity of a suspension of spheroids, each of which is composed of a well conducting interior surrounded by a thin membrane of a comparatively high resistance: See PDF for Equation C, specific capacity of suspension; C_o, static capacity of one sq. cm. of membrane; r, r₁ specific resistances respectively of suspension and of suspending liquid; 2 q major axis of spheroid, α constant tabulated in Table I. 3. The following formula holds practically for any suspension whatever the form of the suspended particle. See PDF for Equation C = C₁₀₀ being the specific capacity of a suspension with a concentration of 100 per cent. Formulæ (1a) and (1b) hold only for the case, when the frequency is so low, that the impedance of the static capacity of the membrane around a single particle is high as compared with the resistance of the interior of the particle. The formulae hold also for a suspension of homogeneous particles, when polarization takes place at the surface of each particle, provided the polarization resistance is low as compared with the impedance of the polarization capacity. 4. A description is given of a method for measuring the capacity of a suspension at frequencies between 800 and 4½ million cycles. By means of a specially designed bridge, a substitution method is employed, by which in the last analysis the suspension is compared with the suspending liquid which is so diluted as to have the same specific resistance as the suspension, consecutive measurements being made in the same electrolytic cell. 5. Formula (1b) is verified by measurements of the capacity of suspensions of varying volume concentrations of the red corpuscles of a dog. 6. By means of the above measurements, the value of C_o is calculated by equation (1a). 7. It is found that C_o is independent of the frequency up to 4½ million cycles and that it is also independent of the suspending liquid. These results furnish considerable evidence of the validity of the theory, that C_o represents the static capacity of a corpuscle membrane. 8. On this assumption and using a probable value for the dielectric constant of the membrane, the thickness of the membrane is calculated to be 3.3·10^–7cm.

THE ELECTRIC RESISTANCE AND CAPACITY OF BLOOD FOR FREQUENCIES BETWEEN 800 AND 4(1/2) MILLION CYCLES

1. The variation of the experimental values (R (ω)), (C (ω)) of the resistance and capacity of blood for increasing frequencies is approximately represented by the equation: See PDF for Equation in which R_o and C_o are the resistance and capacity of the blood at low frequency and See PDF for Equation is the resistance of the blood at infinite frequency. Formulæ (1) and (2) are derived by considering the blood as equivalent to the system shown in the diagram (a) of Fig. 1. 2. By the application of formula (1) to our experimental data the value of R(∞) can be extrapolated with high accuracy. R(∞) represents the resistance) which would have been obtained at low frequency, if the membranes around the corpuscles could have been removed. 3. The specific resistance of the corpuscle interior can be calculated by equation (5), using experimental values for R(∞), for the volume concentration of the blood and for the specific resistance of the serum. 4. The specific resistance of the interior of the red corpuscle of the calf is found to be 3.5 ± 10 per cent times the specific resistance of the serum.

THE RATE OF ESCAPE OF HEMOGLOBIN FROM THE HEMOLYZED RED CORPUSCLE

A theoretical treatment is given of the rate of escape of hemoglobin from the hemolyzed red corpuscle. For complete permeability of the surface, as may perhaps be produced by strong lysins, the time taken for the hemoglobin to decrease to 10 per cent of its original concentration is calculated to be 0.16 seconds (for the human cell). For dilute saponin, giving complete lysis of human cells in 3 minutes, Ponder found a time of escape of 4 seconds, from which the permeability of the membrane to the pigment is calculated to be micro(H) = 5 x 10(-5) cm./sec.

Secondary structure binding motifs of the jet cooled tetrapeptide model Ac–Leu–Val–Tyr(Me)–NHMe

In this paper the structure of the isolated tetrapeptide model Ac-Leu-Val-Tyr(Me)-NHMe (Leu = leucine, Val = valine, Tyr = tyrosine) is investigated by mass- and isomer-selective IR/UV double resonance spectroscopy. Two isomers of this peptide are observed and in combination with force field, ab initio, and DFT calculations these structures are assigned to folded arrangements presenting two different secondary structure binding motifs: (a) a combined gamma-turn/beta-turn structure and (b) a triple gamma-turn structure, which is described for the first time for an isolated model system in the gas phase.

Structure of a β-sheet model system in the gas phase: Analysis of the fingerprint region up to 10 µm

In this communication we report on the conformational analysis of side-chains in the beta-sheet model system (Ac-Phe-OMe)(2) by applying IR/R2PI (infrared/resonant 2-photon ionisation) spectroscopy in the fingerprint region up to 10 microm, where in order to get information in this spectral region an extension of our new high energy and narrow band-width nanosecond IR laser system is presented.

A polymorphism in the IL11 gene is associated with ulcerative colitis

Inflammatory bowel diseases (IBD) are multifactorial disorders characterised by the host's inability to limit the inflammatory response to luminal antigens. The association of polymorphisms in the CARD15 gene with Crohn's disease (CD) demonstrates the relevance of activated transcription factor NF(kappa)B in mononuclear cells. Interleukin 11 (IL11) mediates anti-inflammatory effects and is able to downregulate LPS-induced NF(kappa)B activation. The IL11 gene is therefore a good candidate involved in genetic predisposition to IBD. To evaluate the role of the IL11 gene in IBD, two polymorphisms, including a dinucleotide repeat in the promoter region, have been genotyped in 222 patients with CD, 152 patients with ulcerative colitis (UC) and 400 healthy controls. PCR-SSCP analysis of the coding region revealed a single polymorphism in exon 4 leading to an amino acid exchange (G335A; R112H), not significantly associated with either disease. Dinucleotide repeat frequencies of the IL11.A1 allele and of IL11.A1 homozygous individuals were significantly increased among the patients with UC (P < 0.002 and (P < 0.003, respectively) but not with CD. Altered expression of IL11 appears to be involved in the genetic predisposition of UC.

A polymorphism in the CD14 gene is associated with Crohn disease

BACKGROUND

Inflammatory bowel diseases (IBD) are multifactorial disorders, characterized by failure to limit the inflammatory response to luminal antigens. Although genetic factors play an important role in the pathogenesis, little is known about the genes accountable. Immune response to intestinal bacteria seems to be crucial in the pathogenesis of IBD.

METHODS

To evaluate the role of the CD14 gene in IBD, a functionally relevant polymorphism in the promoter region (T/C at position -159) has been genotyped in 219 patients with Crohn disease (CD), 142 patients with ulcerative colitis (UC) and 410 healthy controls by RFLP analysis.

RESULTS

T allele and TT genotype frequencies were found increased in CD patients compared to controls (Pc=0.044 and 0.005, respectively).

CONCLUSION

An altered immune response to LPS seems to play a role in the genetic predisposition to CD but not to UC.

Monitoring isotretinoin therapy in thyroid cancer using 18F-FDG PET

Treatment with isotretinoin (13-cis-retinoic acid, 13-cis-RA) is a recent additional option in advanced, otherwise intractable differentiated thyroid cancers. The aim of this study was to evaluate fluorine-18 fluorodeoxyglucose positron emission tomography (18F-FDG PET) in the prediction and the monitoring of response to 13-cis-RA therapy. Twenty-one patients with advanced differentiated thyroid cancers were investigated using 18F-FDG PET and iodine-131 whole-body scans before and 3, 6 and 9 months after initiation of 13-cis-RA therapy. After 9 months, 13-cis-RA treatment was discontinued and imaging procedures repeated 3 months later. Average 18F-FDG uptake (SUV) decreased significantly during 13-cis-RA therapy but subsequently increased in five of eight patients after withdrawal of 13-cis-RA. 18F-FDG uptake (SUV) 3 months after onset of 13-cis-RA therapy was significantly lower in patients who developed increased 131I uptake in their tumour sites than in patients with no subsequent increase in 131I uptake. There was no relationship between serum thyroglobulin level on the one hand and simultaneously measured 131I or 18F-FDG uptake on the other hand. There was a tendency towards lower 18F-FDG uptake in tumour manifestations with a better outcome. Therefore, 18F-FDG PET at 3 months after the start of treatment promises to differentiate between those patients who will eventually benefit from 13-cis-RA and those who will not. In conclusion, these data indicate that 18F-FDG PET is a useful tool for the evaluation and monitoring of adjuvant therapy with 13-cis-RA in thyroid cancer.

Resting regional cerebral glucose metabolism in advanced Parkinson's disease studied in the off and on conditions with [(18)F]FDG-PET

Studies of resting regional cerebral glucose consumption (rCMRGlc) in nondemented patients with Parkinson's disease (PD) have produced conflicting results, reporting both reduced and normal metabolism in advanced disease and reduced or normal metabolism after dopaminergic therapy. To investigate these issues, [(18)F]fluorodeoxyglucose (FDG) positron emission tomography (PET) was performed in 11 nondemented PD patients with advanced disease and 10 age-matched controls. PD patients were studied after withdrawal of all dopaminergic medication to produce a practically defined off condition, and a second time 1 hour after levodopa, resulting in a clinical on state. Dynamic PET scans and simultaneous arterialised venous blood samples of [(18)F] activity were obtained. A graphical approach was used to generate parametric images of rCMRGlc and statistical parametric mapping to localise significant metabolic changes in PD. Compared with controls, global rCMRGlc was reduced in the on but not in the off condition in PD. In both states, significant regional reductions of glucose uptake were found in the parietal, frontal, temporal cortex, and caudate nucleus. Reductions correlated with the severity of disability in frontal and temporal cortex. Direct comparison between on and off conditions revealed relatively greater reductions of uptake in the ventral/orbital frontal cortex and the thalamus during on. Results suggest that cortical and caudate hypometabolism are common in advanced PD and that caution is mandatory if [(18)F]FDG PET is being used to differentiate advanced PD from dementia and progressive supranuclear palsy where similar reductions are seen. Furthermore, in PD, administration of levodopa is associated with further hypometabolism in orbitofrontal cortex; an area known to be relevant for reversal learning where performance is typically impaired after dopaminergic treatment.

Methanococcus igneus sp. nov., a novel hyperthermophilic methanogen from a shallow submarine hydrothermal system

A novel hyperthermophilic strictly chemolithoautotrophic member of the genus Methanococcus was isolated from a shallow (depth: 106 m) submarine vent system at the Kolbeinsey ridge, Iceland. The isolate grew between 45 and 91 degrees C with an optimum around 88 degrees C (doubling time: 25 min). It differs from Methanococcus jannaschii in its 16S rRNA sequence, its non-hybridizing DNA, and its selenium-independent growth. Therefore, the isolate represents a new species which we name Methanococcus igneus. Type strain is isolate "Kol 5" (DSM 5666).

Novel SNPs in the CD18 gene validate the association with MPO-ANCA+ vasculitis

Wegener granulomatosis (WG), microscopic polyangiitis (MP), and Churg-Strauss syndrome (CSS) are characterized by the presence of anti-neutrophil cytoplasmic antibodies (ANCA). Anti-myeloperoxidase (MPO)-ANCA are a typical feature of MP and CSS, while anti-proteinase 3 (PRTN3)-ANCA are highly specific for WG. Several reports indicate that ANCA may directly contribute to pathological processes, ie, through an increase of adhesivity between polymorphonuclear (PMN) and endothelial cells (EC). PMN interact and endothelium interact via the adhesion cascade (AC). CD18 is a key molecule of the AC, as CD18 defects abrogate the adhesion of PMN and cause leukocyte adhesion deficiency, an immunodeficient trait. We have screened the entire coding and regulatory regions of the CD18 gene. Ten single nucleotide polymorphisms (SNP) were identified, four of them showing significant associations with MPO-ANCA(+) vasculitis. One of these SNP's was localized in an alternate transcription initiation site. This polymorphism may influence CD18 gene expression, resulting in dose-dependent increase in adhesion and consecutively facilitated degranulation and respiratory burst. In this manner the pro-adherent genotype may predispose to MPO-ANCA(+) vasculitis.

Interleukin-4 and interleukin-4 receptor gene polymorphisms in inflammatory bowel diseases

Imbalances in the regulation of Th1 and Th2 lymphocytes are crucial in inflammatory bowel diseases. Interleukin-4 is secreted by Th2 lymphocytes and downregulates cytokine production from Th1 lymphocytes. Functionally relevant polymorphisms have been described in the interleukin-4 and the interleukin-4 receptor alpha genes. Association of inflammatory bowel diseases with these polymorphisms has been reported recently suggesting high transcription and enhanced signalling activity in Crohn's disease. Our study, comprising 211 patients with Crohn's disease, 147 patients with ulcerative colitis and 446 healthy controls revealed significant association of Crohn's disease with the -590 T allele of the interleukin-4 gene (P = 0.03). This allele entails reduced expression of IL-4. The reason for these contrasting findings may be discussed in the context of a putatively predisposing allele in linkage disequilibrium with the alleles of the interleukin-4 gene.

[1-(11)C]Acetate as a quantitative perfusion tracer in myocardial PET

Our objective was to investigate the properties of [1-(11)C]acetate as a quantitative perfusion tracer for myocardial PET studies.

METHODS

We determined the flow dependence of the effective acetate extraction by a comparison with [(13)N]ammonia in 24 patients at rest (n = 8) and under pharmacologic vasodilation (n = 16). Furthermore, we compared the statistical quality of the perfusion values derived with both tracers. Quantification was based on an irreversible 2-compartment model for [(13)N]ammonia and a reversible 1-compartment model for [1-(11)C]acetate. Area-conserving polar maps were used to determine the correlation between the unidirectional uptake parameters of both tracers on a pixel-by-pixel basis for the whole left ventricular myocardium.

RESULTS

A fit of a generalized Renkin-Crone formula to the data yielded the unidirectional acetate extraction fraction E(f) = 1 - 0.64e(-1.20/f). An extraction correction based on this formula led to good quantitative agreement of perfusion values derived with [(13)N]ammonia and [1-(11)C]acetate over the whole observed flow range (average difference of flow values, 3%; correlation coefficient, 0.96). This agreement proved the applicability of acetate as a quantitative perfusion tracer even under stress conditions. An analysis of the statistical properties of the parameter estimates showed, moreover, that statistical errors were reduced by a factor of nearly 2 in comparison with ammonia.

CONCLUSION

[1-(11)C]acetate allows accurate quantification of myocardial perfusion with PET at rest as well as under stress conditions. The use of acetate leads to distinctly improved statistical accuracy for the perfusion estimates in comparison with ammonia. This accuracy facilitates the generation of reliable parametric polar maps, which are especially useful for clinical application of myocardial perfusion quantification.

The IL-10 gene is not involved in the predisposition to inflammatory bowel disease

Although genetic predisposition for inflammatory bowel disease (IBD) is well established, little is known about the accountable genes. The pathogenesis of IBD is characterized by an imbalanced activation of Th1- and Th2-lymphocytes. IL-10 represents an anti-inflammatory cytokine which downregulates the production of Th1-derived cytokines. To evaluate the role of the IL-10 gene in IBD, two polymorphisms in the promoter region (G/A at position -1082 and C/A at position -592) were genotyped in 142 patients with Crohn's disease (CD), 104 patients with ulcerative colitis (UC), and 400 healthy controls. Significant differences were not apparent, neither in the allele frequencies of either polymorphism, nor in the haplotype frequencies. Screening of the coding region of the IL-10 gene by polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) analysis revealed a rare sequence variation in exon 1 leading to an amino acid exchange (G-->A; G15R) in two patients with CD and five healthy controls. Therefore, polymorphisms of the IL-10 gene are not demonstrably involved in the predisposition of IBD in our cohorts of patients.

A linkage disequilibrium between genes at the serine protease inhibitor gene cluster on chromosome 14q32.1 is associated with Wegener's granulomatosis

The frequency of carriers of the alpha1-antitrypsin (alpha1-AT) deficiency allele PI*Z is increased in patients with Wegener's granulomatosis (WG). The polymorphic protease inhibitor (PI) gene is part of a cluster of serine protease inhibitor (serpin) genes (AACT; alpha1-antichymotrypsin, PCI; protein C inhibitor, CBG; corticosteroid binding globulin, PIL; PI-like pseudogene) at chromosome 14q32.1. In this study we investigated whether the serpin gene cluster contributes to the background of Wegener's granulomatosis. Therefore, phenotyping of alpha1-AT was performed and simple tandem repeat polymorphisms (STRP) in the genes for CBG, PI, and PCI as well as two STRP (D14S55 and D14S48) flanking the centromeric and one (D14S51) flanking the telomeric region of the gene cluster were examined in a population of 79 patients with WG and 128 unrelated healthy controls. In WG patients an increased frequency of the PI*Z defective allele is demonstrated as well as a linkage disequilibrium between all members of this gene cluster plus the centromeric and telomeric STRP. These results indicate an involvement of the serpin genes in the pathogenesis of Wegener's granulomatosis and it is possible that other genes located in the vicinity of D14S55 or D14S51 contribute to the genetic background of the disease.

The polymorphism at position -174 of the IL-6 gene is not associated with inflammatory bowel disease

OBJECTIVE

Inflammatory bowel diseases (IBD) are multifactorial disorders, characterized by failure to limit the inflammatory response to luminal antigens. Genetic factors play an important role in the pathogenesis, but little is known about the accountable genes. Increased secretion of pro-inflammatory cytokines appears crucial in the initiation of the inflammatory response.

METHODS

To evaluate the role of the IL-6 gene in IBD, a functionally relevant polymorphism in the promoter region (G/C at position -174) has been genotyped in 169 patients with Crohn's disease (CD), 133 patients with ulcerative colitis (UC) and 440 healthy controls by using restriction fragment length polymorphism (RFLP) analysis.

RESULTS

No significant differences were apparent in the allele, genotype and carrier frequencies between patients and controls.

CONCLUSION

High secretion of IL-6 does not seem to play a major role in the genetic predisposition to IBD.

Proteinase 3 gene polymorphisms and Wegener's granulomatosis

BACKGROUND

Wegener's granulomatosis (WG) is a rare systemic autoimmune disease characterized by small-vessel vasculitis leading to organ damage and the presence of antineutrophil cytoplasmic autoantibodies (ANCAs). ANCAs were shown to be involved in the pathogenesis of the disease by increasing adhesion of polymorphonuclear cells (PMNs) to endothelial cells and through activation of primed PMN. The main autoantigen of ANCA in WG is proteinase 3 (PR3), a neutrophil- and monocyte-derived neutral serine protease. The association of WG with individuals continuously expressing a high level of PR3 on the surface of PMNs suggests that PR3 variants or altered regulation of PR3 expression might be directly involved in the pathogenesis of the disease.

METHODS

We screened the entire coding and promoter sequences of the PR3 gene for polymorphisms by means of polymerase chain reaction single-strand conformation polymorphism (PCR-SSCP). Allelic, genotypic, and haplotype frequencies were compared between 79 WG patients and a cohort of 129 healthy controls.

RESULTS

Seven single-nucleotide polymorphisms (SNPs), one amino acid change (Val119Ile), one 84 bp insertion/deletion, and a microsatellite were identified. An association with WG could be demonstrated for the A-564G polymorphism in the PR3 promoter affecting a putative transcription factor-binding site.

CONCLUSIONS

This study excludes certain PR3 epitope variants as autoantigenic stimuli in WG, since the Val119Ile polymorphism showed no differences between patients and controls. Overexpression of PR3, however, might predispose the patient to the development of autoimmune ANCA-associated vasculitis.

The IL-10 gene is not involved in the predisposition to inflammatory bowel disease

Although genetic predisposition for inflammatory bowel disease (IBD) is well established, little is known about the accountable genes. The pathogenesis of IBD is characterized by an imbalanced activation of Th1- and Th2-lymphocytes. IL-10 represents an anti-inflammatory cytokine which downregulates the production of Th1-derived cytokines. To evaluate the role of the IL-10 gene in IBD, two polymorphisms in the promoter region (G/A at position -1082 and C/A at position -592) were genotyped in 142 patients with Crohn's disease (CD), 104 patients with ulcerative colitis (UC), and 400 healthy controls. Significant differences were not apparent, neither in the allele frequencies of either polymorphism, nor in the haplotype frequencies. Screening of the coding region of the IL-10 gene by polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) analysis revealed a rare sequence variation in exon 1 leading to an amino acid exchange (G-->A; G15R) in two patients with CD and five healthy controls. Therefore, polymorphisms of the IL-10 gene are not demonstrably involved in the predisposition of IBD in our cohorts of patients.

Water-soluble cooling lubricants induce airway hyperresponsiveness in rabbits

Airway hyperresponsiveness (AHR) to water-soluble cooling lubricants (CL) induced by aerosol administered by tracheal tube was studied in a rabbit model of occupational lung disease. Two commercial CL were examined: the first was of the boric acid amine ester type without biozide (CL-BAE), the second was of the sulfonate type with biozide (CL-SB). 50, 5.0 or 0.5 mg/m3 CL was administered over a period of twice 2 h to six different groups of rabbits. Airway responsiveness (AR) to aerosols of 0.2% and 2.0% acetylcholine solution (ACH) was measured before and after each exposure to CL. A control group A of nine animals not exposed to CL showed no significant respiratory responses following inhalation of 0.2% ACH for 1 min. Conversely, inhalation of 2.0% ACH almost doubled the dynamic elastance (Edyn) in the ACH challenge test in this animal group. Airway resistance (RI), Edyn, slope of inspiratory pressure generation (delta Pes/tI), arterial pressure (Pa) and arterial blood gas tensions (PaO2, PaCO2) were not significantly altered during and after exposures to CL. However, after CL-BAE inhalation of 50 and 5 mg/m3 over 4 h, the amplitude of the ACH-induced airway obstruction indicated by the changes in Edyn rose significantly to almost five times the control response before exposure (group C, D, p < 0.005). Similar changes in RI and delta Pes/tI were obtained. After inhalation of 0.5 mg/m3 CL-BAE (group D), no significant changes in AR were observed. Similar to CL-BAE inhalation of 50 mg/m3, CL-SB caused enlarged AR in the ACH challenge test (group E), whereas no significant changes were found after exposure to 5.0 and 0.5 mg/m3 in groups F and G. In summary, CL aerosols with and without biozide in the range of 50 and 5 mg/m3 applied via tracheal tubes increased AR to ACH within 4 h of exposure in a time- and concentration-dependent manner. It has to be assumed that this augmented AR indicates an increased risk of developing lubricant-induced obstructive lung diseases.

Endothelial cell autoantibodies are a marker of disease susceptibility in inflammatory bowel disease but apparently not linked to persistent measles virus infection

Intestinal vasculitis caused by persistent measles virus infection of intestinal endothelial cells was described in Crohn's disease. Furthermore, endothelial cell autoantibodies have been demonstrated in inflammatory bowel disease (IBD). Autoantibodies against intestinal endothelial cells were visualized by indirect immunofluorescence in patients with IBD, in their healthy first-degree relatives, in patients with infectious enterocolitis, and in healthy, unrelated controls. In intestinal tissue specimens of 22 antibody-positive IBD patients a search for the measles virus genome was performed. Endothelial cell autoantibodies were significantly more frequent in patients with IBD, in both groups of first-degree relatives, and in patients with infectious enterocolitis than in the healthy controls (P = 0.0002 or less). The measles virus genome was found in none of the intestinal biopsies. Endothelial cell autoantibodies are not a genetic but rather an epigenetic (infectious) marker of disease susceptibility. The expression of these autoantibodies is unlikely to be triggered by a persistent measles virus infection.

The association of CD18 alleles with anti-myeloperoxidase subtypes of ANCA-associated systemic vasculitides

Wegener granulomatosis (WG), microscopic polyangiitis (MP), and Churg Strauss syndrome (CSS) are rare systemic autoimmune disorders. Common features are anti-neutrophil cytoplasmic antibodies (ANCA) in patient sera. Whereas WG patients show mainly anti-proteinase 3 ANCA, MP and CSS patients typically present anti-myeloperoxidase (MPO) ANCA. ANCA play an important role in the pathogenesis in the vessel wall by activating polymorphonuclear cells (PMN) and increased adhesivity between PMN and endothelial cells via adhesion molecules. Here we investigated major adhesion molecules as predisposition factors via common polymorphisms in or in the vicinity of the candidate genes ICAM-1, e-selectin, PLAUR, CD11b, and CD18. A restriction fragment-length polymorphism in exon 11 of the CD18 gene was associated with MPO-ANCA(+) systemic vasculitis. Our data indicate that a common variant of the CD18 gene confers increased risk for CSS and MP, supporting that genetic factors are involved in the etiology and pathogenesis of ANCA-associated systemic vasculitides.

Performance evaluation of PET scanners: testing of geometric arc correction by off-centre uniformity measurement

The aim of this study was to demonstrate the necessity of an off-centre uniformity measurement during performance evaluation and acceptance testing of a positron emission tomography (PET) system. To this end, the effect of different methods of geometric arc correction on image uniformity was considered. The arc correction routine of the system software of a particular PET scanner family was tested in computer simulations, phantom measurements and a patient study. Various methods of geometric arc correction--nearest neighbour interpolation, linear interpolation and cubic smoothing spline interpolation--were applied to the same data. Uniformity was evaluated both visually and quantitatively using intensity profiles and regions of interest. The arc correction routine of the PET scanner family produced significant ring artefacts and led to overestimation of tracer uptake by up to 15%. Since uniformity measurements are usually performed using a cylindrical phantom at the centre of the transverse field of view, these artefacts are not detected. In conclusion, the standards for performance evaluation of a PET scanner should be extended by inclusion of an off-centre uniformity measurement at the edge of the transverse field of view. On the basis of our comparison of different methods for geometric arc correction, we suppose that cubic smoothing spline interpolation might improve the relation between statistical noise reduction and spatial resolution as compared with conventional linear interpolation.

Immunogenetic risk factors for anti-neutrophil cytoplasmic antibody (ANCA)-associated systemic vasculitis

Wegener's granulomatosis (WG) and microscopic polyangiitis are systemic autoimmune diseases characterized by the presence of ANCA in the sera of patients. Little is known about the aetiologic factors and genetic predisposition as well as the pathogenesis of these disease entities. A slightly decreased representation of HLA-DRB1*13 and HLA-DQB1*0603 individuals was observed in our cohort of ANCA-associated systemic vasculitis (AASV) patients compared with controls. In addition, HLA-DRB1*04 individuals were over-represented in a subgroup of patients with WG in end-stage renal disease as a result of renal vasculitis. In order to identify other genes relevant for these diseases, we investigated highly polymorphic markers in the vicinity of several immunorelevant genes, i.e. tumour necrosis factor (TNF)alpha, IL-2, IL-5 receptor alpha (IL-5RA), in a group of 102 patients with AASV and compared the representation with controls. Furthermore, functional polymorphisms were directly analysed in the promotor region of TNFalpha as well as in the coding region of the FcgammaIIRA genes. Polymorphisms of the TNFalpha promotor (TNF-308) as well as in the FcgammaIIRA gene were excluded as risk factors for the disease in our cohort. No major phenotype distribution differences were observed between patients and controls for the IL-2 and IL-5RA microsatellites. Most importantly, several haplotypes on chromosome 6p appeared strongly associated with proteinase 3 (PR3)-ANCA+ AASV. Thus, as in other autoimmune diseases, different predisposing factors play differential aetiopathogenic roles in various groups of AASV patients.

Soluble CD40 in the serum of healthy donors, patients with chronic renal failure, haemodialysis and chronic ambulatory peritoneal dialysis (CAPD) patients

CD40 and its ligand CD40L are key players in T cell-B cell interaction and T cell-antigen-presenting cell (APC) interaction. Inhibition of CD40-CD40L interaction leads to severe humoral and cellular immunodeficiency. In this study we examined the presence of soluble CD40 (sCD40) in the serum of haemodialysis (HD) patients, CAPD patients, chronic renal failure (CRF) patients and healthy donors in order to evaluate the possible involvement of CD40 in uraemic immunodeficiency. Soluble CD40 was detected in the serum of healthy donors (n = 41) with a mean of 0.14 +/- 0.12 ng/ml and in the urine of healthy donors with a mean of 1.80 +/- 0.74 ng/ml. Soluble CD40 was highly elevated in all patients with impaired renal function. HD patients (n = 22) had up to 100-fold elevated sCD40 levels with a mean concentration of 8.32 +/- 4.11 ng/ml, whereas CAPD patients (n = 10) had considerably lower levels of sCD40 with a mean of 3.58 +/- 2.40 ng/ml. A strong correlation between sCD40 and serum creatinine levels was noted in CRF patients (n = 66). The highly elevated levels of sCD40 may point to the involvement of CD40 and its ligand CD40L in the clinical manifestation of uraemic immunodeficiency.