Rosiglitazone transiently disturbs calcium homeostasis in monocytic cells

The PPARgamma agonist Rosiglitazone exerts anti-hyperglycaemic effects by regulating the long-term expression of genes involved in metabolism, differentiation and inflammation. In the present study, Rosiglitazone treatment rapidly inhibited (5-30 min) the ER Ca(2+) ATPase SERCA2b in monocytic cells (IC(50)=1.88 microM; p<0.05), thereby disrupting short-term Ca(2+) homeostasis (resting [Ca(2+)](cyto)=121.2+/-2.9% basal within 1h; p<0.05). However, extended Rosiglitazone treatment (72 h) induced dose-dependent SERCA2b up-regulation, and restored calcium homeostasis, in monocytic cells (SERCA2b mRNA: 138.7+/-5.7% basal (1 microM)/215.0+/-30.9% basal (10 microM); resting [Ca(2+)](cyto)=97.3+/-8.3% basal (10 microM)). As unfavourable cardiovascular outcomes, possibly related to disrupted cellular Ca(2+) homeostasis, have been linked to Rosiglitazone, this effect may be of clinical interest. In contrast, in PPRE-luciferase reporter-gene assays, Rosiglitazone induced non-dose-dependent PPARgamma-dependent effects (1 microM: 152.5+/-4.9% basal; 10 microM: 136.1+/-5.1% basal (p<0.05 for 1 microM vs. 10 microM)). Thus, we conclude that Rosiglitazone can exert PPARgamma-independent non-genomic effects, such as the SERCA2b inhibition seen here, but that long-term Rosiglitazone treatment did not perturb resting [Ca](cyto) in this study.

Screening of GABAA-receptor gene mutations in primary dystonia

Several lines of evidence suggest that GABA-ergic neurotransmission plays a role in the pathogenesis of primary dystonia in humans. In this study, we tested the hypothesis that mutations in the GABRA1, GABRB3, and GABRG2 genes encoding the alpha1, beta3, and gamma subunits of the GABA(A) receptor are involved in familial primary dystonia. All exons and exon-intron boundaries of the above genes were amplified by PCR from genomic DNA in 28 patients who had primary dystonia and a positive family history but had no mutation in any other genes known to be involved in primary dystonia. The PCR products were analyzed by single strand conformation polymorphism followed by sequencing of variant conformers compared with normal controls (n = 54). We found no mutations in these genes. We did, however, find a new polymorphism, 559 + 80G>A in intron 5 of GABRA1, and we also confirmed several that were previously reported, including 315C>T in exon 3 and 588C>T in exon 5 of GABRG2, but there were no significant differences between controls and patients in the allele and genotype frequencies of these polymorphisms. In conclusion, mutations of GABRA1, GABRB3, and GABRG2 appear not to play a major role in the development of familial primary dystonia.

Endothelial dysfunction in a murine model of thyroid hormone resistance

BACKGROUND

The development of a knockin mouse model of resistance to thyroid hormone (RTH) has led to a greater understanding of both the molecular and clinical behaviour of this syndrome. We have investigated the vascular response in RTH using a specific (TRbeta PV) knockin mouse model targeting the PV mutation to the thyroid hormone receptor beta gene locus.

MATERIALS AND METHODS

Ring segments of the thoracic aorta were used to assess the response of homozygous, heterozygous and wild-type controls to contractile agents, potassium chloride and phenylephrine. Each genotype after maximal contraction was exposed to increasing concentrations of relaxing agents, acetylcholine (ACh) and sodium nitroprusside (SNP).

RESULTS

The response of these aortic ring segments to ACh and SNP demonstrates that endothelium-dependent relaxation to ACh was significantly impaired in both heterozygous and homozygous mice compared to controls (69.8 +/- 2.0%, 59.7 +/- 1.4% and 75.0 +/- 1.7%, respectively; P < 0.001). However, endothelium independent responses to SNP showed no difference between genotypes (114.4 +/- 3.2%, 116.8 +/- 2.6% and 106.9 +/- 4.9%; P = NS).

CONCLUSION

These data suggest that endothelial function is impaired in the RTH mouse aorta. The respective roles of elevated thyroid stimulating hormone (TSH), elevated thyroid hormone concentrations and the mutated thyroid hormone beta receptor require further elucidation.

Ganciclovir Population Pharmacokinetics in Neonates Following Intravenous Administration of Ganciclovir and Oral Administration of a Liquid Valganciclovir Formulation

Cytomegalovirus (CMV) is the most common viral congenital infection, producing both sensorineural hearing loss and mental retardation. Our objective was to assess the population pharmacokinetics of a research-grade oral valganciclovir solution in neonates with symptomatic congenital CMV disease. Twenty-four neonates received 6 weeks of antiviral therapy. Ganciclovir and valganciclovir were measured by liquid chromatography/tandem mass spectroscopy. NONMEM version VI beta was used for population analyses. All profiles were consistent with a one-compartment model. Postnatal age, body surface area, and gender did not improve the model fit after body weight was taken into account. The typical value of clearance (l/h), distribution volume (l), and bioavailability of ganciclovir were 0.146 x body weight (WT)(1.68), 1.15 x WT, and 53.6%, respectively. Although these results cannot be extrapolated to extemporaneously compounded valganciclovir preparations, they provide the foundation on which a commercial-grade valganciclovir oral solution may be a viable option for administration to neonates.

High- but not low-dose folic acid improves endothelial function in coronary artery disease

BACKGROUND

While folic acid (FA) reduces plasma homocysteine (Hcy), whether the simultaneous improvement in endothelial function is dependent on Hcy lowering per se is questionable. In the present study the relationship between FA dose, Hcy lowering and endothelial function in patients with coronary artery disease (CAD) was investigated.

MATERIALS AND METHODS

Eighty-four patients with CAD received either 400 microg FA or 5 mg placebo daily for a 6-week treatment period. A further 44 patients with CAD received either 100 mg kg(-1) day(-1) of betaine or placebo for a 6-week treatment period. Flow-mediated dilatation (FMD), a measure of endothelial function, was assessed before and after the 6-week periods. Isometric tension and Western blotting were used to investigate the effect of FA on endothelial function and endothelial nitric oxide synthase (eNOS) dimerization in isolated rabbit aortic rings and cultured porcine aortic endothelial cells (PAEC), respectively.

RESULTS

Both 400 micro g day(-1) and 5 mg day(-1) FA significantly increased plasma folate and decreased plasma Hcy. The FMD improved significantly after 6 weeks' treatment of 5 mg day(-1) FA but did not correlate with the reduction in Hcy. There was no change in FMD in either the 400 micro g FA or placebo group. In a subgroup analysis of 11 patients in the betaine group, despite a reduced Hcy, a significant impairment in FMD was observed. In the in vitro studies FA, but not betaine, reversed methionine-induced endothelial dysfunction. Moreover, the FA promoted eNOS dimerization in cultured PAEC.

CONCLUSIONS

These data suggest that FA dose-dependently improves endothelial function in CAD via a mechanism independently of Hcy lowering. It may involve promotion of eNOS dimerization.

Komplikationen bei peripherer Katheterregionalanästhesie

INTRODUCTION

Over a period of 36 months we prospectively documented infectious, neurological and other complications or adverse events occurring during 3,491 peripheral regional anesthesias via a catheter using computer-based data recording.

METHODS

The investigation included 936 axillar plexus catheters, 473 interscalene plexus catheters, 125 vertical infraclavicular plexus catheters, 74 catheters with psoas compartment blocks, 900 femoral nerve catheters, 964 sciatic nerve catheters and 19 catheters in other localizations. The regional anesthesia catheters were inserted under sterile circumstances (hood, facemask, sterile gloves and coat, surgical disinfection and sterile covering of the placement site) and under peripheral nerve stimulation.

RESULTS

3,070 (87.9%) of the regional anesthesias via catheter, were carried out without any complications. Inflammation (two out of three criteria: redness at insertion site, pain on palpation or swelling) was found in 146 patients (4.2% of all cases). Infections (two out of the criteria: CRP elevation, pus on the insertion site, fever, leucocytosis, necessary antibiotic treatment with exclusion of other possible causes) appeared in 2.4% of all cases (83 patients). In 29 patients (0.8%) we observed severe infections (surgical intervention necessary e.g. abscess incision). Risk factors for inflammation or infections included duration of catheter therapy, cervical localization of the catheter and the experience of the anesthesiologist (p<0.05). Bacterial species most frequently found were Staphylococcus aureus (54%) and Staphylococcus epidermidis (38%). In 0.3% (9 patients) we found short lasting neurological deficits and in 6 patients (0.2%) we recorded a nerve lesion that lasted more than 6 weeks. Other complications occurred in 4.2% of all cases.

DISCUSSION

Special complications such as infections in peripheral catheter regional anesthesia are rare but can pose severe problems. A close postoperative supervision of all regional catheters has to be ensured under careful consideration of the risk factors for infections and the accompanying symptoms.

[Large artery wall properties -- what is relevant for the classic management of hypertension?]

Decisions about the management of patients with hypertension should not be based on the level of blood pressure alone but also on the presence of target organ damage. Apart of classical sites of target organ damage - kidney and heart - the assessment of functional and structural alterations of large arteries is of increasing clinical importance. Modern non-invasive procedures allow the assessment of large artery wall properties within the clinical routine. Hypertension associated large artery damage may present as structural and functional alterations. Structural alterations comprise intima-media thickening, plaque formation, stenosis of the artery and formation of aneurysms. Functional alterations comprise endothelial dysfunction and alterations of the mechanical properties of the arterial wall with increasing stiffness and loss of the Windkessel function. Loss of central artery elastic properties will ensue an early reflection of the pulse wave with a resulting increase in central systolic and central diastolic pressure. This causes an increase in left ventricular afterload and a reduction in diastolic perfusion of the myocardium. In the last decade the relevance of large artery structural alterations, endothelial dysfunction and arterial stiffness for the risk of cardiovascular morbidity and mortality in hypertensive patients could be demonstrated convincingly. Measurement of intima-media-thickness therefore is part of the standard evaluation of hypertensive patients. Because of the equal prognostic relevance of functional properties of the arterial wall, assessment of large artery functional alterations is helpful for the risk stratification of hypertensive patients. Modern antihypertensive drugs have favourable effects on arterial wall properties. Therefore, the quantification of large artery wall properties should be part of the management of hypertensive patients.

Functional expression of the renin-angiotensin system in human podocytes

Experimental and clinical studies impressively demonstrate that angiotensin-converting enzyme inhibitors (ACEI) and angiotensin receptor blockers (ARB) significantly reduce proteinuria and retard progression of glomerular disease. The underlying intraglomerular mechanisms are not yet fully elucidated. As podocyte injury constitutes a critical step in the pathogenesis of glomerular proteinuria, beneficial effects of ACEI and ARB may partially result from interference with a local renin-angiotensin system (RAS) in podocytes. The knowledge of expression and function of a local RAS in podocytes is limited. In this study, we demonstrate functional expression of key components of the RAS in differentiated human podocytes: podocytes express mRNA for angiotensinogen, renin, ACE type 1, and the AT(1) and AT(2) angiotensin receptor subtypes. In Western blot experiments and immunostainings, expression of the AT(1) and AT(2) receptor was demonstrated both in differentiated human podocytes and in human kidney cortex. ANG II induced a concentration-dependent increase in cytosolic Ca(2+) concentration via AT(1) receptors in differentiated human podocytes, whereas it did not increase cAMP. Furthermore, ANG II secretion was detected, which was blocked by neither the ACEI captopril nor the renin inhibitor remikiren nor the chymase inhibitor chymostatin. ANG II secretion of podocytes was not increased by mechanical stress. Finally, ANG II was found to increase staurosporine-induced apoptosis in podocytes. We speculate that ACEI and ARB exert their beneficial effects, in part, by interfering with a local RAS in podocytes. Further experiments are required to identify the underlying molecular mechanism(s) of podocyte protection.

Laterale Ischiadikusblockaden

In the present study we examined 41 volunteers using magnetic resonance imaging to obtain biometric data of the thigh used for a planned blockade of the sciatic nerve via the lateral approach. At a needle entry point 12 cm proximal to the gap of the knee joint at the posterior border of the M. vastus lateralis, the sciatic nerve lies on average at a depth of 5.2 cm (39% of the femoral diameter at this site) with an angle of 10.9 degrees to the horizontal in a dorsal direction. Here the popliteal artery lies on average at a depth of 6.4 cm (48% of the femoral diameter) with an angle of 4.7 degrees to the horizontal in a ventral direction. At the marked point in the middle between the gap of the knee joint and the trochanter major at the posterior border of the M. vastus lateralis, the sciatic nerve is at an average depth of 6.2 cm (40% of the femoral diameter at this site) with an angle of 8.2 degrees in a dorsal direction. At a marked point 5 cm distal of the trochanter major at the posterior border of the M. vastus lateralis, the sciatic nerve is at a depth of 9.1 cm at a dorsal angle of 15.5 degrees (49% of the femoral diameter). The lateral blockade of the sciatic nerve at different sites of the thigh is a technique which is easy to plan with the presented biometric data. The popliteal artery could be reached only at the distal puncture point using a deep puncture and an angle in the ventral direction.

Large-scale analysis of 73 329 physcomitrella plants transformed with different gene disruption libraries: production parameters and mutant phenotypes

Gene targeting in the moss Physcomitrella patens has created a new platform for plant functional genomics. We produced a mutant collection of 73 329 Physcomitrella plants and evaluated the phenotype of each transformant in comparison to wild type Physcomitrella. Production parameters and morphological changes in 16 categories, such as plant structure, colour, coverage with gametophores, cell shape, etc., were listed and all data were compiled in a database (mossDB). Our mutant collection consists of at least 1804 auxotrophic mutants which showed growth defects on minimal Knop medium but were rescued on supplemented medium. 8129 haploid and 11 068 polyploid transformants had morphological alterations. 9 % of the haploid transformants had deviations in the leaf shape, 7 % developed less gametophores or had a different leaf cell shape. Other morphological deviations in plant structure, colour, and uniformity of leaves on a moss colony were less frequently observed. Preculture conditions of the plant material and the cDNA library (representing genes from either protonema, gametophore or sporophyte tissue) used to transform Physcomitrella had an effect on the number of transformants per transformation. We found correlations between ploidy level and plant morphology and growth rate on Knop medium. In haploid transformants correlations between the percentage of plants with specific phenotypes and the cDNA library used for transformation were detected. The number of different cDNAs present during transformation had no effect on the number of transformants per transformation, but it had an effect on the overall percentage of plants with phenotypic deviations. We conclude that by linking incoming molecular, proteome, and metabolome data of the transformants in the future, the database mossDB will be a valuable biological resource for systems biology.

Representation and high-quality annotation of the Physcomitrella patens transcriptome demonstrates a high proportion of proteins involved in metabolism in mosses

To gain insight into the transcriptome of the well-used plant model system Physcomitrella patens, several EST sequencing projects have been undertaken. We have clustered, assembled, and annotated all publicly available EST and CDS sequences in order to represent the transcriptome of this non-seed plant. Here, we present our fully annotated knowledge resource for the Physcomitrella patens transcriptome, integrating annotation from the production process of the clustered sequences and from a high-quality annotation pipeline developed during this study. Each transcript is represented as an entity containing full annotations and GO term associations. The whole production, filtering, clustering, and annotation process is being modelled and results in seven datasets, representing the annotated Physcomitrella transcriptome from different perspectives. We were able to annotate 63.4 % of the 26 123 virtual transcripts. The transcript archetype, as covered by our clustered data, is compared to a compilation based on all available Physcomitrella full length CDS. The distribution of the gene ontology annotations (GOA) for the virtual transcriptome of Physcomitrella patens demonstrates consistency in the ratios of the core molecular functions among the plant GOA. However, the metabolism subcategory is over-represented in bryophytes as compared to seed plants. This observation can be taken as an indicator for the wealth of alternative metabolic pathways in moss in comparison to spermatophytes. All resources presented in this study have been made available to the scientific community through a suite of user-friendly web interfaces via www.cosmoss.org and form the basis for assembly and annotation of the moss genome, which will be sequenced in 2005.

Psoasabszess bei Psoaskompartmentkatheter

A 27-year-old female patient was continuously treated with a psoas compartment catheter for pain therapy. The catheter was placed under strictly aseptic conditions. After 5 days a painful swelling and erythema were observed at the catheter introduction site and the catheter was removed. At the tip of the catheter a staphylococcus aureus infection was detected. A few days after removing the catheter, the patient showed signs of a general infection such as fever and an increase of CRP. An abscess of the psoas muscle was diagnosed via computer tomography. After treatment with antibiotics the abscess was healed and the patient was discharged after 21 days. An abscess of the psoas muscle is a rare complication of psoas compartment catheters. Erythema, pain or swelling at the site of introduction can be a sign of infection and the catheter must be removed immediately. In addition to the case report a review of the literature is given with data on risk management and own infection rates by 2304 peripheral pain catheters.

Clinical and molecular genetic evaluation of patients with primary dystonia

Primary dystonia is a movement disorder characterized by involuntary and sustained muscle contractions causing twisting or abnormal postures and mutations in several genes have been identified. Our goal was to investigate, whether the clinical presentation would differ between patients with a positive family history, and patients without. Furthermore, we have performed mutation analysis in the subgroup of patients with a positive family history. A total of 175 patients with primary dystonia were evaluated. Data on gender, presence and frequency of pain and tremor, age of onset, and the distribution of affected body parts were compared between patients with positive and negative family history. All exons of the torsion dystonia 1, GTP cyclohydrolase 1 and epsilon-sarcoglycan genes were examined in 40 patients by SSCP analysis of PCR products followed by sequencing of variant conformers. Dystonia patients with a positive family history of dystonia had an earlier age of onset and those with a positive family history of tremor more often associated tremor than those with a negative family history. Four new polymorphisms in the epsilon-sarcoglycan gene were found and others confirmed, but no known or new mutations could be detected. Our study supports the notion that primary dystonia is a genetically heterogeneous disease.

[Management of patients with chronic renal failure]

Terminal renal failure has an incidence of approximately 60 persons per million population, and is on the increase. Victims suffer from an appreciably compromised quality of life and life expectancy. The financial burden on the health service imposed by the need for renal replacement therapy (dialysis or renal transplantation) is considerable. To achieve a therapeutic impact, the underlying kidney disease, as well as the factors driving progression and injury need to be identified as early as possible. Of particular importance in this connection is the rigorous management of arterial hypertension with the use of ACE inhibitors, dietetic measures and normalization of hemoglobin levels.

Radial glial cells, proliferating periventricular cells, and microglia might contribute to successful structural repair in the cerebral cortex of the lizard Gallotia galloti

Reptiles are the only amniotic vertebrates known to be capable of spontaneous regeneration of the central nervous system (CNS). In this study, we analyzed the reactive changes of glial cells in response to a unilateral physical lesion in the cerebral cortex of the lizard Gallotia galloti, at 1, 3, 15, 30, 120, and 240 days postlesion. The glial cell markers glial fibrillary acidic protein (GFAP), glutamine synthetase (GS), S100 protein, and tomato lectin, as well as proliferating cell nuclear antigen (PCNA) were used to evaluate glial changes occurring because of cortical lesions. A transitory and unilateral upregulation of GFAP and GS in reactive radial glial cells were observed from 15 to 120 days postlesion. In addition, reactive lectin-positive macrophage/microglia were observed from 1 to 120 days postlesion, whereas the expression of S100 protein remained unchanged throughout the examined postlesion period. The matricial zones closest to the lesion site, the sulcus lateralis (SL) and the sulcus septomedialis (SSM), showed significantly increased numbers of dividing cells at 30 days postlesion. At 240 days postlesion, the staining pattern for PCNA, GFAP, GS, and tomato lectin in the lesion site became similar to that observed in unlesioned controls. In addition, ultrastructural data of the lesioned cortex at 240 days postlesion indicated a structural repair process. We conclude that restoration of the glial framework and generation of new neurons and glial cells in the ventricular wall play a key role in the successful structural repair of the cerebral cortex of the adult lizard.

Multi-channel magnetocardiography for detecting beat morphology variations in fetal arrhythmias

OBJECTIVE

Over the last few years, a number of studies have shown that fetal magnetocardiography (fMCG) is useful in describing fetal cardiac activity. A 55-channel MCG system in Ulm was used to record fetal cardiac activity in 12 pregnant women (with normal fetal heart activity in echocardiography) and in 5 pregnant women in whom the echocardiography showed fetal arrhythmias.

METHOD

The recorded MCG data were treated in order to eliminate the maternal signal and three MCG channels with the best signals were used to emulate a standard electrocardiogram (ECG) recording so that standard MCG analysis could be performed.

RESULTS

The results in assessing fetal electrophysiology, demonstrating its potential, are presented here for two fetuses with recorded supraventricular extrasystoles (SVES) and for one with ventricular extrasystoles (VES). Concerning the SVES, the analysis software OMEGA was able to separate three different beat morphologies. The VES could be detected exactly and have been confirmed by postnatal ECG.

CONCLUSION

The beat morphology and the beat-to-beat variations allow new insights into the electrophysiology of the fetal heart.

[Prenatal diagnosis and outcome of fetal bradyarrhythmias]

BACKGROUND

The purpose of this study was to evaluate the clinical outcome of fetuses with bradyarrhythmias or complete heart block (CHB) in the setting of fetal structural heart disease (CHD) or of maternal collagenosis with and without treatment.

METHODS

A retrospective analysis of echocardiographic studies performed in 14 fetuses (mean gestational age 25.5, range 19 - 36 weeks) referred for exclusion or diagnosis of bradyarrhytmias was performed. Maternal SS-A/Ro and SS-B/La antibodies were measured by ELISA.

RESULTS

14 fetuses showed bradyarrhythmias or complete heart block in combination with severe cardiac malformations (n = 7) or with positive maternal antibodies (n = 7). Only one of the fetuses with CHD survived infancy as opposed to 5/7 fetuses with complete atrioventricular block in the setting of maternal collagenosis. Maternal treatment with corticosteroids did not seem to influence the rhythm disorder.

CONCLUSION

Fetal echography is a safe method to detect bradyarrhythmias or complete atrioventricular block. When associated with structural heart defects, fetal prognosis is poorer than in combination with maternal collagenosis.

Influence of hemodialysis membrane permeability on serum levels of advanced glycation end products (AGEs) and homocysteine metabolites

BACKGROUND

[corrected] Advanced glycation end products (AGEs), total homocysteine (tHcy) and the homocysteine metabolites cystathionine (Cysta) and dimethylglycine (DMG) are increased in serum of patients with end-stage renal disease. The aim of this prospective randomized study was to compare the efficacy of polysulfone high-flux vs. polysulfone low-flux hemodialysis (HD) treatment regarding removal of AGEs, tHcy, Cysta and DMG.

PATIENTS AND METHODS

Twenty-nine patients on chronic HD treatment were randomly assigned to 2 groups in a 3-period 2-treatment design with low flux (A)--high flux (B)--low flux (A) for group I and B-A-B for group II, 6 weeks each period. The following parameters were measured in pre- and postdialytic serum samples at baseline and the end of each period: total serum fluorescence, Nepsilon-carboxymethyllysine (CML), free and protein-bound pentosidine, tHcy, Cysta and DMG.

RESULTS

There was increased removal of free pentosidine during high-flux HD treatment compared to low-flux HD treatment, attaining significance between the second and third treatment periods (group 1: 86.0 +/- 4.7% vs. 79.2 +/- 8.8%, p = 0.007; group II: 84.0 +/- 6.3% vs. 79.8 +/- 9.8%, p = 0.049 for high vs. low flux). The intradialytic reduction rates for total serum fluorescence, tHcy, Cysta, DMG did not differ between high- and low-flux HD treatment. Protein-bound pentosidine and CML did not decrease during the dialysis sessions, neither with high-flux nor with low-flux HD membrane. Despite a strong decrease during single HD session, the predialytic levels of free pentosidine, tHcy, Cysta and DMG remained unchanged during the study period both for high- and low-flux HD treatment.

CONCLUSION

The more pronounced effect of high-flux dialysis on the removal rate of free pentosidine, found in this randomized crossover study, could not translate into a significant difference in predialysis levels after a 6-week treatment period. We could not find any differences between polysulfone high- and low-flux membranes for lowering predialytic serum concentrations of the measured AGEs, which are mainly bound on albumin.