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1.
Article in English | MEDLINE | ID: mdl-38943224

ABSTRACT

INTRODUCTION: Women with systemic lupus erythematosus (SLE) have a higher risk for fetal and maternal complications. We aimed to investigate maternal and fetal complications in pregnant women with SLE compared to a high-risk pregnancy cohort (HR) from a tertiary university center and a standard-risk general population (SR) from the Austrian Birth Registry. MATERIAL AND METHODS: In this retrospective data analysis, we compared the incidence of fetal/neonatal and maternal complications of pregnancies and deliveries of women with SLE to age, body mass index and delivery date-matched high-risk pregnancies from the same department, a progressive tertiary obstetric center and to a group of women, who represent pregnancies with standard obstetric risk from the Austrian Birth Registry. RESULTS: One hundred women with SLE were compared to 300 women with high-risk pregnancies and 207 039 women with standard-risk pregnancies. The incidence of composite maternal complications (preeclampsia, Hemolysis, Elevated Liver enzymes and Low Platelets [HELLP] syndrome, pregnancy-related hypertension, gestational diabetes mellitus, maternal death, thromboembolic events) was significantly higher in the SLE as compared to the SR group (28% vs. 6.28% SLE vs. SR, p = 0.001). There was no difference between the SLE and the HR groups (28% vs. 29.6% SLE vs. HR group, p = 0.80). The incidence of composite fetal complications (preterm birth before 37 weeks of gestation, stillbirths, birth weight less than 2500 g, fetal growth restriction, large for gestational age, admission to neonatal intensive care unit, 5-min Apgar <7) was also higher in the SLE than in the SR group (55% vs. 25.54% SLE vs. SR p < 0.001) while the higher incidence of adverse fetal outcome was detected in the HR than in the SLE group (55% vs. 75% SLE vs. HR group, p = 0.0005). CONCLUSIONS: Although composite fetal risk is higher in the SLE group than in the general population, it is still significantly lower as compared to high-risk pregnant women at a tertiary obstetric center. Prepregnancy counseling of women with SLE should put fetal and maternal risk in perspective, not only in relation to healthy, low risk cohorts, but also compared to mixed HR populations.

2.
Infection ; 2024 Mar 06.
Article in English | MEDLINE | ID: mdl-38446279

ABSTRACT

BACKGROUND: Listeria monocytogenes is a bacterial pathogen known for causing listeriosis, a foodborne illness with a wide spectrum of clinical presentations ranging from mild gastroenteritis to severe invasive disease, particularly affecting immunocompromised individuals, pregnant women, newborns, and the elderly. Successful treatment of patients with recurring listeria episodes due to colonised foreign material is often challenging, typically requiring a combination of antimicrobial treatment and surgical removal. CASE PRESENTATION: Here, we present a particularly complex case of chronic invasive listeriosis with a total of six relapses. After extensive investigations, the patient's ICD device was identified as the focus of infection. CONCLUSION: The confirmation of relapses through cgMLST analysis highlights the persistence of Listeria monocytogenes and the potential for recurrence even after apparent resolution of symptoms in patients with foreign material. It emphasises the necessity for a comprehensive assessment to identify and mitigate the risk of relapses, thereby ensuring optimal management and outcomes.

3.
Chaos ; 34(1)2024 Jan 01.
Article in English | MEDLINE | ID: mdl-38285721

ABSTRACT

We consider reaction-diffusion systems and other related dissipative systems on unbounded domains with the aim of showing that self-similarity, besides the well-known exact self-similar solutions, can also occur asymptotically in two different forms. For this, we study systems on the unbounded real line that have the property that their restriction to a finite domain has a Lyapunov function (and a gradient structure). In this situation, the system may reach local equilibrium on a rather fast time scale, but on unbounded domains with an infinite amount of mass or energy, it leads to a persistent mass or energy flow for all times; hence, in general, no true equilibrium is reached globally. In suitably rescaled variables, however, the solutions to the transformed system converge to so-called non-equilibrium steady states that correspond to asymptotically self-similar behavior in the original system.

4.
Emerg Infect Dis ; 29(11): 2349-2352, 2023 11.
Article in English | MEDLINE | ID: mdl-37877608

ABSTRACT

Tularemia is increasing in Austria. We report Francisella tularensis subspecies holarctica isolated from 3 patients who had been bitten by arthropods. Next-generation sequencing showed substantial isolate similarity. Clinicians should consider bloodstream F. tularensis infections for patients with signs/symptoms of ulceroglandular tularemia, and surveillance of potential vectors should be intensified.


Subject(s)
Bites and Stings , Francisella tularensis , Tularemia , Humans , Tularemia/diagnosis , Tularemia/epidemiology , Francisella tularensis/genetics , Austria/epidemiology
5.
Euro Surveill ; 27(24)2022 06.
Article in English | MEDLINE | ID: mdl-35713023

ABSTRACT

We describe a gonorrhoea case with ceftriaxone plus high-level azithromycin resistance. In April 2022, an Austrian heterosexual male was diagnosed with gonorrhoea after sexual intercourse with a female sex worker in Cambodia. Recommended treatment with ceftriaxone (1 g) plus azithromycin (1.5 g) possibly failed. Worryingly, this is the second strain in an Asian Neisseria gonorrhoeae genomic sublineage including high-level azithromycin-resistant strains that developed ceftriaxone resistance by acquisition of mosaic penA-60.001. Enhanced resistance surveillance and actions are imperative to prevent spread.


Subject(s)
Gonorrhea , Sex Workers , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Austria , Azithromycin/pharmacology , Azithromycin/therapeutic use , Ceftriaxone/pharmacology , Ceftriaxone/therapeutic use , Drug Resistance, Bacterial/genetics , Female , Gonorrhea/diagnosis , Gonorrhea/drug therapy , Gonorrhea/epidemiology , Humans , Male , Microbial Sensitivity Tests , Neisseria gonorrhoeae/genetics , Treatment Failure
7.
J Psychiatr Pract ; 21(4): 275-80, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26164053

ABSTRACT

BACKGROUND: In patients with affective disorders, the full-blown symptomatology of a depressive episode can develop very fast (e.g., within 1 d) or slowly over weeks or months. These differences in the speed of onset of depression are likely to reflect stable intraindividual differences in neurobiological pathomechanisms. This article presents available data on this issue from published studies and from a recently unpublished study and discusses the relevance of these data for diagnostic, therapeutic, and research purposes. METHODS: On the basis a database search, we reviewed the literature on speed of onset of depressive episodes. Results of a study for which only some of the data have previously been published involving 205 patients with unipolar or bipolar depression were also considered. RESULTS: Five older studies produced data concerning the speed of onset of depressive episodes. In addition, our research group has conducted 2 other more recent studies that used the Onset of Depression Inventory to assess the speed of onset of depressive episodes. The major findings of the studies we examined were that depression developed within 1 week in 50% to 58% of patients with a bipolar disorder, whereas only in 7.4% to 21.4% of those with unipolar depression. Different depressive episodes appeared to develop at a similar speed within individual subjects (correlation coefficients: 0.46 to 0.66). CONCLUSIONS: Consistent evidence from 2 studies that used the Onset of Depression Inventory revealed that rapid onset of a depressive episode is more common in patients with bipolar disorder than in those with unipolar major depressive disorder and may be an indication of a latent, not yet expressed, bipolar disorder. The neurobiology of the speed of onset of depressive episodes is a topic for future research.


Subject(s)
Bipolar Disorder , Depressive Disorder , Adult , Bipolar Disorder/diagnosis , Bipolar Disorder/psychology , Depressive Disorder/diagnosis , Depressive Disorder/psychology , Female , Humans , Male , Middle Aged , Psychiatric Status Rating Scales , Psychometrics/methods , Recurrence , Time Factors
8.
ALTEX ; 30(2): 169-208, 2013.
Article in English | MEDLINE | ID: mdl-23665806

ABSTRACT

Threats of pyrogenicity were discovered more than a century ago. Measures to determine the safety of parenterals and, more recently, medical devices and cell therapies for human use have been in place for 70 years. Currently, there are three testing possibilities available: the Rabbit Pyrogen Test, the Limulus Amebocyte Lysate test (Bacterial Endotoxin Test), and test systems using human whole blood or human monocytes, called Monocyte Activation Test (MAT). The MAT is based on the human fever reaction and thus most closely reflects the human situation. Unfortunately, regulations and testing guidelines are not fully harmonized, despite formal international validation. Furthermore, data showing that the MAT is capable of covering the totality of possible pyrogens relevant to humans were not included in the MAT validations of the last decade. For this review we collate evidence from published literature, unpublished data of our own, and results from the international validation study to show that there is overwhelming scientific evidence to conclude that the whole blood MAT reliably detects non-endotoxin pyrogens. Therefore, further validation exercises do not seem warranted.


Subject(s)
Monocytes/drug effects , Pyrogens/chemistry , Pyrogens/toxicity , Toxicity Tests/methods , Animals , Drug Contamination/prevention & control , Humans , Pharmaceutical Preparations/standards
9.
Eur J Pharm Biopharm ; 84(2): 251-4, 2013 Jun.
Article in English | MEDLINE | ID: mdl-23499778

ABSTRACT

The introduction of the animal's dignity as a concern in animal welfare legislation in Switzerland is unique worldwide. Naturally, this measure has raised hopes and fears in those concerned with animal welfare and animal use. For the past several years, a lively debate has focused on the question of whether the addition is merely a declaration of intent or an explicit demand with, possibly, a profound impact on everyday practice. What the implications may be in the latter case is not clear. In the area of research, it has yet to be seen how this concept may be incorporated feasibly, for example, into the harm-benefit analysis, which is the prerequisite for the approval of an animal experiment. It is foreseeable, therefore, that this addition might have direct implications on research. Unfortunately, in the legislative text, there are some inconsistencies in wording, at least in the German version, that complicate interpretation. This article provides a short overview of some aspects of the controversy, which is far from settled at this time. The commentary will be restricted to the situation of experimental animals in Switzerland.


Subject(s)
Animal Experimentation/ethics , Animal Experimentation/legislation & jurisprudence , Animal Welfare , Animals, Laboratory , Animals , Biomedical Research/ethics , Biomedical Research/legislation & jurisprudence , Language , Research Design , Switzerland
10.
Open Biomed Eng J ; 4: 190-8, 2010.
Article in English | MEDLINE | ID: mdl-21625373

ABSTRACT

Current strategies for tissue engineering of bone rely on the implantation of scaffolds, colonized with human mesenchymal stem cells (hMSC), into a recipient. A major limitation is the lack of blood vessels. One approach to enhance the scaffold vascularisation is to supply the scaffolds with endothelial cells (EC).The main goal of this study was to establish a coculture system of hMSC and EC for the purposes of bone tissue engineering. Therefore, the cell behaviour, proliferation and differentiation capacity in various cell culture media as well as cell interactions in the cocultures were evaluated.The differentiation capacity of hMSC along osteogenic, chondrogenic, and adipogenic lineage was impaired in EC medium while in a mixed EC and hMSC media, hMSC maintained osteogenic differentiation. In order to identify and trace EC in the cocultures, EC were transduced with eGFP. Using time-lapse imaging, we observed that hMSC and EC actively migrated towards cells of their own type and formed separate clusters in long term cocultures. The scarcity of hMSC and EC contacts in the cocultures suggest the influence of growth factor-mediated cell interactions and points to the necessity of further optimization of the coculture conditions.

11.
Electrophoresis ; 30(21): 3674-81, 2009 Nov.
Article in English | MEDLINE | ID: mdl-19862747

ABSTRACT

Alternative splicing is capable of generating multiple mRNA variants from a single gene and is hence a key mediator of molecular diversity generated at the transcript level. Consequently, delivering quantitative information on the fractions of splice variants is essential for the understanding of their biological roles. Here we compare techniques for subtle splice variant quantification that are able to resolve length differences as small as one nucleotide: PAGE with ethidium-bromide densitometry, pyrosequencing, and CE-LIF. We give comprehensive descriptions of assay designs and calibration procedures and present an evaluation of these methods in terms of accuracy, reproducibility and applicability. We also examined template concentrations and reverse transcription-coupled PCR conditions as potential cause of biased results as they were observed for extreme low template concentrations and/or PCR amplicons with size differences of 195 nt. As proof of concept, we determine the splice ratios of variants differing by 3 and 12 nt in five human tissues. We demonstrate that CE-LIF is the most precise and also the most labor- and time-efficient method.


Subject(s)
Densitometry/methods , Electrophoresis, Capillary/methods , Electrophoresis, Polyacrylamide Gel/methods , Protein Isoforms/genetics , Reverse Transcriptase Polymerase Chain Reaction/methods , Sequence Analysis, DNA/methods , Ethidium/chemistry , Humans , Least-Squares Analysis , Nuclear Proteins/genetics , Nuclear Proteins/metabolism , RNA-Binding Proteins/genetics , RNA-Binding Proteins/metabolism , Reproducibility of Results , Research Design , Reverse Transcriptase Polymerase Chain Reaction/standards , Tissue Distribution
12.
ALTEX ; 26(4): 265-77, 2009.
Article in English | MEDLINE | ID: mdl-20383472

ABSTRACT

Microorganisms such as Gram-negative or Gram-positive bacteria, viruses and fungi contain components that activate the innate immune system. These components, called pyrogens (Greek: pyros=fire), can occur independently of viable microorganisms and are a major safety concern in parenterally administered drugs, since they can cause severe reactions such as fever, organ failure, and shock in the recipient. So far these drugs have been tested by injecting them intravenously into rabbits and measuring their fever reaction or, alternatively, by the Limulus Amoebocyte Lysate (LAL) test, employing the coagulation of the hemolymph lysate of Limulus polyphemus. Both tests have inherent limitations. A new in vitro monocyte activation test (MAT) based on human whole blood, capable of measuring all pyrogens relevant to the human patient, introduced in this journal in 1995, was validated and recently accepted by European Pharmacopoeia and US FDA. This review describes its principle, development, validation and the wide spectrum of applications, such as for testing of medical devices, blood products, toxic or immunomodulatory drugs, dialysis liquids, lipidic parenterals, and air quality. This alternative method promises to replace the rabbit pyrogen test fully and to overcome several limitations of the LAL assay.


Subject(s)
Monocytes/drug effects , Pyrogens/toxicity , Animal Testing Alternatives , Animals , Bacteria/metabolism , Blood , Cryopreservation , Humans , Pharmaceutical Preparations/analysis , Pharmaceutical Preparations/blood , Pyrogens/metabolism , Rabbits , Reagent Kits, Diagnostic , Reproducibility of Results
13.
BMC Genomics ; 9: 202, 2008 Apr 30.
Article in English | MEDLINE | ID: mdl-18447903

ABSTRACT

BACKGROUND: The splicing of pre-mRNAs is conspicuously often variable and produces multiple alternatively spliced (AS) isoforms that encode different messages from one gene locus. Computational studies uncovered a class of highly similar isoforms, which were related to tandem 5'-splice sites (5'ss) and 3'-splice sites (3'ss), yet with very sparse anecdotal evidence in experimental studies. To compare the types and levels of alternative tandem splice site exons occurring in different human organ systems and cell types, and to study known sequence features involved in the recognition and distinction of neighboring splice sites, we performed large-scale, stringent alignments of cDNA sequences and ESTs to the human and mouse genomes, followed by experimental validation. RESULTS: We analyzed alternative 5'ss exons (A5Es) and alternative 3'ss exons (A3Es), derived from transcript sequences that were aligned to assembled genome sequences to infer patterns of AS occurring in several thousands of genes. Comparing the levels of overlapping (tandem) and non-overlapping (competitive) A5Es and A3Es, a clear preference of isoforms was seen for tandem acceptors and donors, with four nucleotides and three to six nucleotides long exon extensions, respectively. A subset of inferred A5E tandem exons was selected and experimentally validated. With the focus on A5Es, we investigated their transcript coverage, sequence conservation and base-paring to U1 snRNA, proximal and distal splice site classification, candidate motifs for cis-regulatory activity, and compared A5Es with A3Es, constitutive and pseudo-exons, in H. sapiens and M. musculus. The results reveal a small but authentic enriched set of tandem splice site preference, with specific distances between proximal and distal 5'ss (3'ss), which showed a marked dichotomy between the levels of in- and out-of-frame splicing for A5Es and A3Es, respectively, identified a number of candidate NMD targets, and allowed a rough estimation of a number of undetected tandem donors based on splice site information. CONCLUSION: This comparative study distinguishes tandem 5'ss and 3'ss, with three to six nucleotides long extensions, as having unusually high proportions of AS, experimentally validates tandem donors in a panel of different human tissues, highlights the dichotomy in the types of AS occurring at tandem splice sites, and elucidates that human alternative exons spliced at overlapping 5'ss posses features of typical splice variants that could well be beneficial for the cell.


Subject(s)
RNA Splice Sites , Alternative Splicing , Animals , Base Sequence , Conserved Sequence , DNA/genetics , DNA, Intergenic/genetics , Databases, Nucleic Acid , Exons , Humans , Mice , Molecular Sequence Data , Tandem Repeat Sequences
14.
BMC Genomics ; 9: 159, 2008 Apr 10.
Article in English | MEDLINE | ID: mdl-18402682

ABSTRACT

BACKGROUND: Several recent studies indicate that alternative splicing in Arabidopsis and other plants is a common mechanism for post-transcriptional modulation of gene expression. However, few analyses have been done so far to elucidate the functional relevance of alternative splicing in higher plants. Representing a frequent and universal subtle alternative splicing event among eukaryotes, alternative splicing at NAGNAG acceptors contributes to transcriptome diversity and therefore, proteome plasticity. Alternatively spliced NAGNAG acceptors are overrepresented in genes coding for proteins with RNA-recognition motifs (RRMs). As SR proteins, a family of RRM-containing important splicing factors, are known to be extensively alternatively spliced in Arabidopsis, we analyzed alternative splicing at NAGNAG acceptors in SR and SR-related genes. RESULTS: In a comprehensive analysis of the Arabidopsis thaliana genome, we identified 6,772 introns that exhibit a NAGNAG acceptor motif. Alternative splicing at these acceptors was assessed using available EST data, complemented by a sequence-based prediction method. Of the 36 identified introns within 30 SR and SR-related protein-coding genes that have a NAGNAG acceptor, we selected 15 candidates for an experimental analysis of alternative splicing under several conditions. We provide experimental evidence for 8 of these candidates being alternatively spliced. Quantifying the ratio of NAGNAG-derived splice variants under several conditions, we found organ-specific splicing ratios in adult plants and changes in seedlings of different ages. Splicing ratio changes were observed in response to heat shock and most strikingly, cold shock. Interestingly, the patterns of differential splicing ratios are similar for all analyzed genes. CONCLUSION: NAGNAG acceptors frequently occur in the Arabidopsis genome and are particularly prevalent in SR and SR-related protein-coding genes. A lack of extensive EST coverage can be compensated by using the proposed sequence-based method to predict alternative splicing at these acceptors. Our findings indicate that the differential effects on NAGNAG alternative splicing in SR and SR-related genes are organ- and condition-specific rather than gene-specific.


Subject(s)
Alternative Splicing , Arabidopsis Proteins/genetics , Arabidopsis/genetics , Arabidopsis/metabolism , RNA Splice Sites , beta Karyopherins/genetics , Cold Temperature , Gene Expression Regulation, Plant , Genome, Plant , Hot Temperature
15.
Genome Biol ; 8(8): R154, 2007.
Article in English | MEDLINE | ID: mdl-17672918

ABSTRACT

BACKGROUND: Despite some degeneracy of sequence signals that govern splicing of eukaryotic pre-mRNAs, it is an accepted rule that U2-dependent introns exhibit the 3' terminal dinucleotide AG. Intrigued by anecdotal evidence for functional non-AG 3' splice sites, we carried out a human genome-wide screen. RESULTS: We identified TG dinucleotides functioning as alternative 3' splice sites in 36 human genes. The TG-derived splice variants were experimentally validated with a success rate of 92%. Interestingly, ratios of alternative splice variants are tissue-specific for several introns. TG splice sites and their flanking intron sequences are substantially conserved between orthologous vertebrate genes, even between human and frog, indicating functional relevance. Remarkably, TG splice sites are exclusively found as alternative 3' splice sites, never as the sole 3' splice site for an intron, and we observed a distance constraint for TG-AG splice site tandems. CONCLUSION: Since TGs splice sites are exclusively found as alternative 3' splice sites, the U2 spliceosome apparently accomplishes perfect specificity for 3' AGs at an early splicing step, but may choose 3' TGs during later steps. Given the tiny fraction of TG 3' splice sites compared to the vast amount of non-viable TGs, cis-acting sequence signals must significantly contribute to splice site definition. Thus, we consider TG-AG 3' splice site tandems as promising subjects for studies on the mechanisms of 3' splice site selection.


Subject(s)
Genome, Human , Guanine Nucleotides/metabolism , Introns , RNA Splice Sites , RNA, Small Nuclear/metabolism , Thymine Nucleotides/metabolism , Base Sequence , Humans , Molecular Sequence Data , Spliceosomes/metabolism
16.
J Biomed Mater Res A ; 80(2): 276-82, 2007 Feb.
Article in English | MEDLINE | ID: mdl-16958052

ABSTRACT

Medical devices manufactured for implantation into humans must be free of any contamination with viable bacteria. However, remnants of dead bacteria and bacterial components alone may induce an inflammatory immune response. Pyrogen tests for such inflammatory contaminations are generally performed either by determining the content of lipopolysaccharide in rinsing solutions of batch samples by limulus amoebocyte lysate assay, by injecting the rinsing solutions into rabbits or by implanting batch samples into rabbits and measuring change of body temperature. In this study, we show that the in vitro pyrogen test (IPT), which measures the release of the inflammatory cytokine IL-1beta in fresh or cryopreserved human whole blood, can be used to assess the pyrogenic contamination of implantable medical devices. This test was used to check neurosurgical implants, namely aneurysm clips, as a proof of principle. Owing to the direct contact of the test material with the blood cells, this test does not require rinsing procedures, which have variable efficacy. The use of human blood ensures the detection of all substances that are pyrogenic for humans and reflects their relative potency. The safety of the products as delivered could be confirmed. The effects of sterilization and depyrogenization procedures on intentional pyrogenic contaminations of samples could be followed. This new application of the already internationally validated method promises to replace further rabbit pyrogen tests. It generates extremely sensitive results with an extended range of detectable pyrogenic contaminants.


Subject(s)
Equipment and Supplies/microbiology , Prostheses and Implants/microbiology , Pyrogens/analysis , Equipment and Supplies/standards , Humans , Interleukin-1beta/blood , Methods , Microbiological Techniques/methods , Prostheses and Implants/standards , Sterilization , Surgical Instruments/microbiology
17.
J Immunol Methods ; 316(1-2): 42-51, 2006 Oct 20.
Article in English | MEDLINE | ID: mdl-16996078

ABSTRACT

Pyrogens as fever-inducing agents can be a major health hazard in parenterally applied drugs. For the control of these contaminants, pyrogen testing for batch release is required by pharmacopoeias. This has been done either by the in vivo rabbit pyrogen test (since 1942) or the limulus amoebocyte lysate test (LAL), since 1976. New approaches include cell-based assays employing in vitro culture of human immune cells which respond e.g. by cytokine production (IL-1beta; IL-6) upon contact with pyrogens. Six variants of these assays have been validated in a collaborative international study. The recent successful development of cryopreservation methods promises to make standardized immunoreactive primary human blood cells available for widespread use. Furthermore, the pretesting of donors for infectious agents such as HIV or hepatitis has made it possible to develop a safe and standardised reagent for pyrogen testing. Using a total of 13 drugs, we have validated the pyrogen test based on fresh and cryopreserved human whole blood in four laboratories. The test reached >90% sensitivity and specificity. In contrast to the LAL, the test was capable of detecting non-endotoxin pyrogens derived from Gram-positive bacteria or fungi.


Subject(s)
Lipopolysaccharides/blood , Pharmaceutical Preparations/blood , Pyrogens/blood , Animal Testing Alternatives , Blood , Cryopreservation , Humans , Lipopolysaccharides/analysis , Pharmaceutical Preparations/analysis , Pyrogens/analysis , Reproducibility of Results , Sensitivity and Specificity
18.
Pediatr Res ; 60(2): 210-5, 2006 Aug.
Article in English | MEDLINE | ID: mdl-16864706

ABSTRACT

Mortality and long-term sequelae rates are high among adults and children with acute bacterial meningitis. Adjunctive treatment with dexamethasone has been shown to reduce systemic complications in bacterial meningitis patients, but corticosteroid treatment may have detrimental effects on hippocampal function. We evaluated the effect of dexamethasone treatment in addition to antibiotic therapy in a rabbit model of Escherichia coli meningitis. A moderate anti-inflammatory effect of dexamethasone could be demonstrated with respect to the inflammatory mediator prostaglandin E2, whereas no significant effect of dexamethasone on tumor necrosis factor-alpha, cerebrospinal fluid pleocytosis, protein, lactate, indicators of global neuronal damage, or blood gas analysis was found. Dexamethasone, however, increased the rate of apoptotic neurons in the granular layer of the hippocampal dentate gyrus. In view of the proapoptotic effect of adjunctive dexamethasone on hippocampal neuronal cells in animal models of Gram-positive and Gram-negative meningitis, the application of dexamethasone should be considered carefully in those forms of bacterial meningitis for which no evidence-based data of beneficial effect in humans are available, such as neonatal meningitis, bacillary Gram-negative meningitis or nosocomial forms of meningitis (e.g. following neurosurgery).


Subject(s)
Dentate Gyrus/drug effects , Dexamethasone/toxicity , Meningitis, Escherichia coli/drug therapy , Neurons/drug effects , Animals , Apoptosis , Dentate Gyrus/pathology , Dexamethasone/therapeutic use , Dinoprostone/cerebrospinal fluid , Disease Models, Animal , Hippocampus/drug effects , Hippocampus/pathology , Leukocytosis/cerebrospinal fluid , Neurons/pathology , Rabbits , Tumor Necrosis Factor-alpha/cerebrospinal fluid
19.
J Immunol Methods ; 298(1-2): 161-73, 2005 Mar.
Article in English | MEDLINE | ID: mdl-15847806

ABSTRACT

It is a requirement that parenteral medicines be tested for pyrogens (fever causing agents) using one of two animal-based tests: the rabbit pyrogen test and the bacterial endotoxin test. Understanding the human fever reaction has led to novel non-animal alternative tests based on in vitro activation of human monocytoid cells in response to pyrogens. Using 13 prototypic drugs, clean or contaminated with pyrogens, we have validated blindly six novel pyrogen tests in ten laboratories. Compared with the rabbit test, the new tests have a lower limit of detection and are more accurate as well as cost and time efficient. In contrast to the bacterial endotoxin test, all tests are able to detect Gram-positive pyrogens. The validation process showed that at least four of the tests meet quality criteria for pyrogen detection. These validated in vitro pyrogen tests overcome several shortcomings of animal-based pyrogen tests. Our data suggest that animal testing could be completely replaced by these evidence-based pyrogen tests and highlight their potential to further improve drug safety.


Subject(s)
Biological Assay , Monocytes/metabolism , Pyrogens/analysis , Animals , Biological Assay/economics , Biological Assay/methods , Humans , Rabbits , Reproducibility of Results , Sensitivity and Specificity , Time Factors
20.
J Immunol Methods ; 294(1-2): 89-100, 2004 Nov.
Article in English | MEDLINE | ID: mdl-15604019

ABSTRACT

Human whole blood assays are increasingly employed to test immune function or detect pyrogenic contamination, since they offer advantages, such as ease of performance, few preparation artifacts and a physiological cell environment. However, the approach is often limited by the availability of freshly drawn blood, putative safety concerns in the case of infected donors and interindividual donor differences. To overcome these limitations, a method was developed and optimized to produce batches of cryopreserved blood that can be used directly after thawing without any washing steps. Mononuclear cells remained intact as shown by FACS analysis. Cytokine release could be induced by a variety of immunological stimuli. The cell preparation released higher amounts of interleukin-1beta (IL-1beta) and IL-6 compared to fresh blood, but no TNF. These differences could be attributed to the presence of the cryoprotectant dimethylsulfoxide (DMSO) alone by addition of DMSO to fresh blood. Large batches of cryopreserved blood could be produced by mixing blood donations of up to 10 donors, independent of differing blood groups. The detection limit for the World Health Organization (WHO) lipopolysaccharides (endotoxin, LPS) reference preparation (EC-6) with regard to the induction of IL-1beta release was at least 0.5 endotoxin equivalent units (EU)/ml. Endotoxin spikes at the limit concentrations prescribed in the European Pharmacopoeia could be detected in a series of drugs, showing that the In vitro Pyrogen Test (IPT) can also be run with cryopreserved blood. Further possible applications include high-throughput screening for immunomodulators or toxins as well as preservation of patient samples for later analysis of cell functions.


Subject(s)
Blood , Cryopreservation , Cytokines/metabolism , Leukocytes, Mononuclear/metabolism , Lipopolysaccharides/analysis , Pyrogens/analysis , Blood Group Antigens , Cryoprotective Agents/chemistry , Dimethyl Sulfoxide/chemistry , Europe , Humans , Leukocytes, Mononuclear/cytology , Lipopolysaccharides/pharmacology , Pharmaceutical Preparations/analysis , Pharmacopoeias as Topic/standards , Pyrogens/pharmacology , Reference Standards , Reproducibility of Results , Sensitivity and Specificity , World Health Organization
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