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Biomedical subjects

M Reindl

Publications and source records attributed to M Reindl.

29 records · Page 2Linked to original sources
PubMed2000

A critical comparison of frequently used methods for the analysis of tumor necrosis factor-alpha expression by human immune cells.

A variety of methods have been developed for the measurement of tumor necrosis factor (TNF)-alpha synthesis by immune cells. Here we have compared the results of the most common used methods, including in vitro stimulation of whole blood or peripheral blood mononuclear cell (PBMC) cultures with phytohaemagglutinin (PHA) or lipopolysaccharide (LPS) and RT-PCR analysis of TNF-alpha transcription in unstimulated PBMC. When we used EDTA treated blood samples we observed a significant correlation between the PHA and LPS stimulated TNF-alpha responses in whole blood or PBMC cultures. In contrast, TNF-alpha concentrations obtained from PHA and LPS stimulated whole blood cultures from citrate-treated blood did not show a correlation. We also found that the PHA stimulated TNF-alpha response was significantly higher in PBMC than in whole blood cultures, whereas the highest LPS stimulated TNF-alpha response was observed in citrate-treated blood. Moreover, the TNF-alpha response in both, citrate and EDTA treated whole blood cultures was significantly higher after LPS than after PHA stimulation. In contrast, in PBMC cultures the PHA stimulated TNF-alpha response was significantly higher than the LPS stimulated response. The results of RT-PCR analysis revealed a significant correlation with the PHA stimulated TNF-alpha response, both in whole blood assays and in PBMC cultures. In addition our results demonstrate that these different methods can only be compared when the influence of external factors such as the immediate processing of blood samples or the use of an appropriate anticoagulant and stimulant is considered.

Biological Assay↗
PubMed2000

Immunopathogenic and clinical relevance of antibodies against myelin oligodendrocyte glycoprotein (MOG) in Multiple Sclerosis.

Recent neuropathological findings identified four distinct immunopathogenic pathways of demyelination and tissue destruction in the most common inflammatory demyelinating central nervous system disorder, Multiple Sclerosis. One of this neuropathological subtypes is characterised by features of antibody-mediated demyelination. A role of anti-myelin antibodies in the disease evolution of multiple sclerosis has been suggested already for a long time, however, their pathogenetic and clinical relevance is not understood yet. This present article will discuss recently published and some preliminary data on the immunopathogenic role of antibodies against myelin oligodendrocyte glycoprotein (MOG) and other myelin/nonmyelin targets in multiple sclerosis, as well as possible clinical implications for prognosis and therapy in the future.

Animals↗
PubMed2000

Expression of Fas and Fas ligand after experimental traumatic brain injury in the rat.

Apoptotic cell death plays an important role in the cascade of neuronal degeneration after traumatic brain injury (TBI), but the underlying mechanisms are not fully understood. However, increasing evidence suggests that expression of Fas and its ligand (FasL) could play a major role in mediating apoptotic cell death in acute and chronic neurologic disorders. To further investigate the temporal pattern of Fas and FasL expression after experimental TBI in the rat, male Sprague Dawley rats were subjected to unilateral cortical impact injury. The animals were killed and examined for Fas and FasL protein expression and for immunohistologic analysis at intervals from 15 minutes to 14 days after injury. Increased Fas and FasL immunoreactivity was seen in the cortex ipsilateral to the injury site from 15 minutes to 72 hours after the trauma, respectively. Immunohistologic investigation demonstrated a differential pattern of Fas and FasL expression in the cortex, respectively: increased Fas immunoreactivity was seen in cortical astrocytes and neurons from 15 minutes to 72 hours after the injury. In contrast, increased expression of FasL was seen in cortical neurons, astrocytes, and microglia from 15 minutes to 72 hours after impact injury. Concurrent double-labeling examinations using terminal deoxynucleotidyl transferase-mediated deoxyuridine-biotin nick end labeling identified Fas- and FasL-immunopositive cells with high frequency in the cortex ipsilateral to the injury site. In contrast, there was no evidence of Fas- and FasL-immunopositive cells in the hippocampus ipsilateral to the injury site up to 14 days after the trauma. Further, Fas and FasL immunoreactivity was absent in the contralateral cortex and hippocampus at all time points investigated. These results reveal induction of Fas and FasL expression in the cortex after TBI in the rat. Further, these data implicate an involvement of Fas and FasL in the pathophysiologic mechanism of apoptotic neurodegeneration after TBI. Last, these data suggest that strategies aimed to repress posttraumatic Fas- and FasL-induced apoptosis may open new perspectives for the treatment of TBI.

Animals↗
PubMed1999

Bioavailability of interferon beta 1b in MS patients with and without neutralizing antibodies.

BACKGROUND: Neutralizing antibodies (NAB) to interferon beta (IFNbeta) occur in about one-third of MS patients treated with IFNbeta-1b and there is an association with a loss of clinical and MRI efficacy. However, there are no data regarding the bioavailability of IFNbeta-1b in patients with and without NAB. METHODS: The authors measured MxA in whole blood by ELISA, and serum-binding antibodies (SBA) by Western blot and ELISA in 134 samples of MS patients on IFNbeta-1b and 54 control subjects, and correlated the MxA levels and SBA titers with the NAB titer. RESULTS: In the IFNbeta group 84 samples were NAB negative, 21 were NAB positive (i.e., titer of > or =20), and 29 had detectable NAB (i.e., titer between 10 and 20). The median MxA concentration in NAB-negative patients was 4.09 ng/10(5) peripheral blood leukocytes (PBL), 2.37 ng/10(5) PBL in samples with detectable NAB, 0.36 ng/10(5) PBL in NAB-positive samples, and 0.27 ng/10(5) PBL in control subjects. There was no significant difference between NAB-positive samples and control subjects, otherwise the groups differed significantly from each other. SBA occurred in 49% of NAB-negative samples, in 79% of samples with detectable NAB, and in all NAB-positive samples. With regard to the SBA titer, all groups differed significantly from each other. In none of the control samples were SBA detected. CONCLUSION: The conversion of SBA into NAB depends to some degree on the SBA titer, but other mechanisms may be involved. Once NAB have developed, the bioavailability of IFNbeta as measured by MxA is completely inhibited.

Antibodies↗
PubMed1999

Increased expression of apolipoprotein D following experimental traumatic brain injury.

Increasing evidence suggests that apolipoprotein D (apoD) could play a major role in mediating neuronal degeneration and regeneration in the CNS and the PNS. To investigate further the temporal pattern of apoD expression after experimental traumatic brain injury in the rat, male Sprague-Dawley rats were subjected to unilateral cortical impact injury. The animals were killed and examined for apoD mRNA and protein expression and for immunohistological analysis at intervals from 15 min to 14 days after injury. Increased apoD mRNA and protein levels were seen in the cortex and hippocampus ipsilateral to the injury site from 48 h to 14 days after the trauma. Immunohistological investigation demonstrated a differential pattern of apoD expression in the cortex and hippocampus, respectively: Increased apoD immunoreactivity in glial cells was detected from 2 to 3 days after the injury in cortex and hippocampus. In contrast, increased expression of apoD was seen in cortical and hippocampal neurons at later time points following impact injury. Concurrent histopathological examination using hematoxylin and eosin demonstrated dark, shrunken neurons in the cortex ipsilateral to the injury site. In contrast, no evidence of cell death was observed in the hippocampus ipsilateral to the injury site up to 14 days after the trauma. No evidence of increased apoD mRNA or protein expression or neuronal pathology by hematoxylin and eosin staining was detected in the contralateral cortex and hippocampus. Our results reveal induction of apoD expression in the cortex and hippocampus following traumatic brain injury in the rat. Our data also suggest that increased apoD expression may play an important role in cortical neuronal degeneration after brain injury in vivo. However, increased expression of apoD in the hippocampus may not necessarily be indicative of neuronal death.

Animals↗
PubMed1999

Antibodies against the myelin oligodendrocyte glycoprotein and the myelin basic protein in multiple sclerosis and other neurological diseases: a comparative study.

In experimental animal models of multiple sclerosis demyelinating antibody responses are directed against the myelin oligodendrocyte glycoprotein (MOG). We have investigated whether a similar antibody response is also present in multiple sclerosis patients. Using the recombinant human extracellular immunoglobulin domain of MOG (MOG-Ig) we have screened the sera and CSFs of 130 multiple sclerosis patients, 32 patients with other inflammatory neurological diseases (OIND), 30 patients with other non-inflammatory neurological diseases (ONND) and 10 patients with rheumatoid arthritis. We report that 38% of multiple sclerosis patients are seropositive for IgG antibodies to MOG-Ig compared with 28% seropositive for anti-myelin basic protein (MBP). In contrast, OIND are characterized by similar frequencies of serum IgG antibody responses to MOG-Ig (53%) and MBP (47%), whereas serum IgG responses to MOG-Ig are rare in ONND (3%) and rheumatoid arthritis (10%). Anti-MBP IgG antibodies, however, are a frequent finding in ONND (23%) and rheumatoid arthritis (60%). Our results provide clear evidence that anti-MOG-Ig antibodies are common in CNS inflammation. However, in OIND these antibody responses are transient, whereas they persist in multiple sclerosis. We demonstrate that the serum anti-MOG-Ig response is already established in early multiple sclerosis (multiple sclerosis-R0; 36%). In later multiple sclerosis stages frequencies and titres are comparable with early multiple sclerosis. In contrast, the frequency of anti-MBP antibodies is low in multiple sclerosis-R0 (12%) and increases during disease progression in relapsing-remitting (32%) and chronic progressive multiple sclerosis (40%), thus suggesting that anti-MBP responses accumulate over time. Finally we provide evidence for intrathecal synthesis of IgG antibodies to MOG-Ig in multiple sclerosis.

Adult↗
PubMed1997

The thymus and self-tolerance: co-existence of encephalitogenic S100 beta-specific T cells and their nominal autoantigen in the normal adult rat thymus.

The adoptive transfer of auto-reactive T cells specific for S100 beta protein mediates experimental autoimmune panencephalomyelitis, an inflammatory autoimmune disease of the nervous system and eye. However, unlike classical encephalitogenic autoantigens which are components of the myelin membrane and restricted to the nervous system, S100 beta is expressed by many different cell types in a wide variety of peripheral tissues. We now report that S100 beta is also expressed within the rat thymus from embryonic day 16 through to adulthood at which time point the protein is localized within stroma cells of the thymic medulla. However, despite the continued expression of this autoantigen within the thymic microenvironment it proved possible to isolate encephalitogenic, S100 beta-specific CD4+ alpha beta TCR T cell lines from the naive adult rat thymus. These T cell lines were highly specific for S100 beta, and following activation in vitro and adoptive transfer initiate an inflammatory response in the central nervous system and eye of naive syngeneic recipients. These observations provide additional evidence that clonal deletion of autoaggressive T cell clones in the thymus is leaky. In this case allowing potentially autoaggressive T cell clones specific for S100 beta, a non-myelin autoantigen expressed in the nervous system, thymus and many peripheral tissues, to become an intrinsic component of the normal immune repertoire.

Animals↗
PubMed1995

Cloning, structural organization and regulation of expression of the Penicillium chrysogenum paf gene encoding an abundantly secreted protein with antifungal activity.

An abundantly secreted, highly basic 12-kDa protein (PAF) was purified from the culture medium of Penicillium chrysogenum (Pc). Based on the N-terminal amino acid (aa) sequence of the protein, an oligodeoxyribonucleotide probe was derived and used for amplification of the encoding cDNA by PCR. This cDNA fragment encodes a Cys-rich preproprotein of 92 aa which appears to be processed to a mature product of 55 aa. The deduced aa sequence of the preproprotein reveals 42.6% identity to an antifungal protein (AFP) of Aspergillus giganteus. Agar diffusion tests confirmed that the Pc protein exhibits antifungal activity. In order to investigate the promoter region and the structural organization of the paf gene, a genomic 6-kb fragment was isolated and partially sequenced. Comparison of the nucleotide sequence of the genomic fragment and the cDNA clone revealed the presence of a coding region of 279 bp which is interrupted by two introns of 76 and 68 bp in length. In the promoter region, a typical TATA box, a motif resembling the fungal carbon catabolite repression element, as well as several putative GATA factor binding motifs, were found. Northern blot analysis indicated that the regulation of paf expression occurs at the level of mRNA transcription and is under control of carbon catabolite and nitrogen metabolite repression regulatory circuits.

Amino Acid Sequence↗
PubMed1993

Isolation and analysis of a linear plasmid-located gene of Borrelia burgdorferi B29 encoding a 27 kDa surface lipoprotein (P27) and its overexpression in Escherichia coli.

Using an antiserum of a patient with cutaneous manifestations of Lyme borreliosis we have isolated the gene encoding a 27 kDa protein antigen (P27) of Borrelia burgdorferi B29 from a lambda-gt11 expression library. Nucleotide sequence analysis revealed that it is a basic protein of 248 amino acids with a typical prokaryotic leader sequence of 17 amino acid residues at the N-terminus of the proposed translation product. Biochemical investigations showed that P27 is a surface-exposed lipoprotein. From pulsed-field gel electrophoresis and subsequent Southern blot analysis it is evident that the p27 gene is located on a linear plasmid of a size of approximately 55 kb. It was overexpressed in Escherichia coli and the purified recombinant protein was used for biochemical and serological studies. Northern and Western blot analysis demonstrated that p27 is expressed in the European B. burgdorferi strain B29, but not in the American strain B31.

Amino Acid Sequence↗