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Endmayr V, Tunc C, Ergin L, De Rosa A, Weng R, Wagner L, Yu TY, Fichtenbaum A, Perkmann T, Haslacher H, Kozakowski N, Schwaiger C, Ricken G, Hametner S, Klotz S, Dutra LA, Lechner C, de Simoni D, Poppert KN, Müller GJ, Pirker S, Pirker W, Angelovski A, Valach M, Maestri M, Guida M, Ricciardi R, Frommlet F, Sieghart D, Pinter M, Kircher K, Artacker G, Höftberger R, Koneczny I. Anti-Neuronal IgG4 Autoimmune Diseases and IgG4-Related Diseases May Not Be Part of the Same Spectrum: A Comparative Study. Front Immunol 2022; 12:785247. [PMID: 35095860 PMCID: PMC8795769 DOI: 10.3389/fimmu.2021.785247] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 12/15/2021] [Indexed: 12/18/2022] Open
Abstract
Background IgG4 is associated with two emerging groups of rare diseases: 1) IgG4 autoimmune diseases (IgG4-AID) and 2) IgG4-related diseases (IgG4-RLD). Anti-neuronal IgG4-AID include MuSK myasthenia gravis, LGI1- and Caspr2-encephalitis and autoimmune nodo-/paranodopathies (CNTN1/Caspr1 or NF155 antibodies). IgG4-RLD is a multiorgan disease hallmarked by tissue-destructive fibrotic lesions with lymphocyte and IgG4 plasma cell infiltrates and increased serum IgG4 concentrations. It is unclear whether IgG4-AID and IgG4-RLD share relevant clinical and immunopathological features. Methods We collected and analyzed clinical, serological, and histopathological data in 50 patients with anti-neuronal IgG4-AID and 19 patients with IgG4-RLD. Results A significantly higher proportion of IgG4-RLD patients had serum IgG4 elevation when compared to IgG4-AID patients (52.63% vs. 16%, p = .004). Moreover, those IgG4-AID patients with elevated IgG4 did not meet the diagnostic criteria of IgG4-RLD, and their autoantibody titers did not correlate with their serum IgG4 concentrations. In addition, patients with IgG4-RLD were negative for anti-neuronal/neuromuscular autoantibodies and among these patients, men showed a significantly higher propensity for IgG4 elevation, when compared to women (p = .005). Last, a kidney biopsy from a patient with autoimmune paranodopathy due to CNTN1/Caspr1-complex IgG4 autoantibodies and concomitant nephrotic syndrome did not show fibrosis or IgG4+ plasma cells, which are diagnostic hallmarks of IgG4-RLD. Conclusion Our observations suggest that anti-neuronal IgG4-AID and IgG4-RLD are most likely distinct disease entities.
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Affiliation(s)
- Verena Endmayr
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Cansu Tunc
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Lara Ergin
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Anna De Rosa
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Rosa Weng
- Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Lukas Wagner
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Thin-Yau Yu
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Andreas Fichtenbaum
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Thomas Perkmann
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | - Helmuth Haslacher
- Department of Laboratory Medicine, Medical University of Vienna, Vienna, Austria
| | | | - Carmen Schwaiger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Gerda Ricken
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Simon Hametner
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Sigrid Klotz
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Lívia Almeida Dutra
- Department of Neurology and Neurosurgery, Hospital Israelita Albert Einstein, São Paulo, Brazil
| | - Christian Lechner
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
- Pediatric Neurology, Department of Pediatric and Adolescent Medicine, Medical University of Innsbruck, Innsbruck, Austria
| | - Désirée de Simoni
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
- Department of Neurology, University Hospital St. Poelten, St. Poelten, Austria
| | - Kai-Nicolas Poppert
- Department of Neurology, Christian Doppler University Hospital, Paracelsus Medical University, Salzburg, Austria
| | - Georg Johannes Müller
- Department of Neurology and Karl Landsteiner Institute for Neuroimmunological and Neurodegenerative Disorders, Klinik Donaustadt, Vienna, Austria
| | - Susanne Pirker
- Department of Neurology, Klinik Hietzing, Vienna, Austria
| | - Walter Pirker
- Department of Neurology, Klinik Ottakring, Vienna, Austria
| | | | - Matus Valach
- Department of Pathology, Klinik Landstrasse, Vienna, Austria
| | - Michelangelo Maestri
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Melania Guida
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Roberta Ricciardi
- Department of Clinical and Experimental Medicine, Neurology Unit, University of Pisa, Pisa, Italy
| | - Florian Frommlet
- Center for Medical Statistics, Informatics and Intelligent Systems, Section for Medical Statistics, Medical University of Vienna, Vienna, Austria
| | - Daniela Sieghart
- Division of Rheumatology, Department of Internal Medicine III, Medical University of Vienna, Vienna, Austria
| | - Miklos Pinter
- Wiener Privatklinik – Health Center, Vienna, Austria
| | - Karl Kircher
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Gottfried Artacker
- Department of Pediatrics and Adolescent Medicine, Klinik Donaustadt, Vienna, Austria
| | - Romana Höftberger
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
| | - Inga Koneczny
- Division of Neuropathology and Neurochemistry, Department of Neurology, Medical University of Vienna, Vienna, Austria
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Müller GJ, Hasseldam H, Rasmussen RS, Johansen FF. Dexamethasone enhances necrosis-like neuronal death in ischemic rat hippocampus involving μ-calpain activation. Exp Neurol 2014; 261:711-9. [PMID: 25135859 DOI: 10.1016/j.expneurol.2014.08.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Revised: 08/07/2014] [Accepted: 08/12/2014] [Indexed: 11/29/2022]
Abstract
Transient forebrain ischemia (TFI) leads to hippocampal CA1 pyramidal cell death which is aggravated by glucocorticoids (GC). It is unknown how GC affect apoptosis and necrosis in cerebral ischemia. We therefore investigated the co-localization of activated caspase-3 (casp-3) with apoptosis- and necrosis-like cell death morphologies in CA1 of rats treated with dexamethasone prior to TFI (DPTI). In addition, apoptosis- (casp-9, casp-3, casp-3-cleaved PARP and cleaved α-spectrin 145/150 and 120kDa) and necrosis-related (calpain-specific casp-9 cleavage, μ-calpain upregulation and cleaved α-spectrin 145/150kDa) cell death mechanisms were investigated by Western blot analysis. DPTI expedited CA1 neuronal death from day 4 to day 1 and increased the magnitude of CA1 neuronal death from 66.2% to 91.3% at day 7. Furthermore, DPTI decreased the overall (days 1-7) percentage of dying neurons displaying apoptosis-like morphology from 4.7% to 0.3% and, conversely, increased the percentage of neurons with necrosis-like morphology from 95.3% to 99.7%. In animals subjected to TFI without dexamethasone (ischemia-only), 7.4% of all dying CA1 neurons were casp-3-immunoreactive (IR), of which 3.1% co-localized with apoptosis-like and 4.3% with necrosis-like changes. By contrast, DPTI decreased the percentage of dying neurons with casp-3 IR to 1.4%, of which 0.3% co-localized with apoptosis-like changes and 1.1% with necrosis-like changes. Western blot analysis from DPTI animals showed a significant elevation of μ-calpain, a calpain-produced necrosis-related casp-9 fragment (25kDa) and cleavage of α-spectrin into 145/150kDa fragments at day 4, whereas in ischemia-only animals a significant increase of casp-3-cleaved PARP, cleavage of α-spectrin into 145/150 and 120kDa fragments was detected at day 7. We conclude that DPTI, in addition to augmenting and expediting CA1 neuronal death, causes a shift from apoptosis-like cell death to necrosis involving μ-calpain activation.
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Affiliation(s)
- Georg Johannes Müller
- Department of Biomedical Sciences, University of Copenhagen, Ole Maaloesvej 5, Copenhagen 2200, Denmark; Department of Neurology, Donauspital, Langobardenstrasse 122, A-1220 Vienna, Austria.
| | - Henrik Hasseldam
- Department of Biomedical Sciences, University of Copenhagen, Ole Maaloesvej 5, Copenhagen 2200, Denmark
| | - Rune Skovgaard Rasmussen
- Department of Biomedical Sciences, University of Copenhagen, Ole Maaloesvej 5, Copenhagen 2200, Denmark
| | - Flemming Fryd Johansen
- Department of Biomedical Sciences, University of Copenhagen, Ole Maaloesvej 5, Copenhagen 2200, Denmark
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Smedema JP, Müller GJ. Coronary spasm and thrombosis in a bodybuilder using a nutritional supplement containing synephrine, octopamine, tyramine and caffeine. S Afr Med J 2008; 98:372-373. [PMID: 18637307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023] Open
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Müller GJ, Lassmann H, Johansen FF. Anti-apoptotic signaling and failure of apoptosis in the ischemic rat hippocampus. Neurobiol Dis 2007; 25:582-93. [PMID: 17207631 DOI: 10.1016/j.nbd.2006.11.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2006] [Revised: 10/03/2006] [Accepted: 11/03/2006] [Indexed: 11/18/2022] Open
Abstract
Several anti-apoptotic proteins are induced in CA1 neurons after transient forebrain ischemia (TFI), but fail to protect the majority of these cells from demise. Correlating cell death morphologies (apoptosis-like and necrosis-like death) with immunohistochemistry (IHC), we investigated whether anti-apoptosis contributes to survival, compromises apoptosis effector functions and/or delays death in CA1 neurons 1-7 days after TFI. As surrogate markers for bioenergetic failure, the IHC of respiratory chain complex (RCC) subunits was investigated. Dentate granule cell (DGC) apoptosis following colchicine injection severed as a reference for classical apoptosis. Heat shock protein 70 (Hsp70), neuronal apoptosis inhibitory protein (NAIP) and manganese superoxide dismutase (MnSOD) were upregulated in the majority of intact CA1 neurons paralleling the occurrence of CA1 neuronal death (days 3-7) as well as in a proportion of apoptosis-(<50%) and necrosis-like (<30%) CA1 neurons. Colchicine did not provoke an anti-apoptotic response in DGC at all. In addition, more than 70% of apoptosis- and necrosis-like CA1 neurons had completely lost their RCC subunits suggesting bioenergetic failure; by contrast, following colchicine injection, 88% of all apoptotic DGC presented RCC subunits. Thus, anti-apoptotic proteins may, in a subset of ischemic CA1 neurons, prevent cell death, while in others, affected by pronounced energy failure, they may cause secondary necrosis.
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Affiliation(s)
- Georg Johannes Müller
- Molecular Neuropathology Group, University of Copenhagen, 11, Frederik V's vej, 2100-Copenhagen-O, Denmark
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Müller GJ, Dogonowski AM, Finsen B, Johansen FF. Expression of glutamic acid decarboxylase and identification of GABAergic cells in the ischemic rat dentate gyrus. Exp Brain Res 2006; 175:556-66. [PMID: 16906421 DOI: 10.1007/s00221-006-0572-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2006] [Accepted: 05/24/2006] [Indexed: 11/26/2022]
Abstract
We have investigated the glutamic acid dexcarboxylase (GAD) mRNA and protein isoforms as markers for ischemic loss of GABAergic neurons in the dentate hilus. Stereological counts of these neurons were performed in rats surviving 8 days after 10 min of transient forebrain ischemia, and in control rats (sham-operated and naïve). GAD65 and GAD67 were detected by both in situ hybridization and immunocytochemistry. No differences (three-way ANOVA, P > 0.05) were found between treatments (ischemia, sham-operated or naïve) when cell counts of identical GAD isoforms were compared at the same level (mRNA or protein). However, irrespective of treatments, the number of neurons expressing GAD65 mRNA was significantly higher than the number of neurons expressing GAD65 protein, and the number of neurons expressing GAD67 mRNA was significantly lower than the number of neurons expressing GAD67 protein. In parallel, we investigated the colocalization of the cell death marker Fluorojade B (FJB) with somatostatin- or GAD67-immunoreactivity in hilus of control and ischemic rats. Although the majority of FJB positive cells also contained somatostatin, a small number of GAD67 immunoreactive neurons contained FJB, suggesting that a small number of GABAergic neurons die after ischemia. In conclusion, this study provides direct evidence that a small proportion of GABAergic hilar neurons succumbs to ischemia. Stereological counts of neurons identified from their expression of either GAD isoform of mRNA or protein revealed a high inter-animal variation at any detection level in both naïve, sham-operated and ischemic rats. Therefore, counts of GABAergic neurons should be carefully interpreted in accordance with the marker used for identification.
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Affiliation(s)
- Georg Johannes Müller
- Molecular Neuropathology Group, Institute of Molecular Pathology, University of Copenhagen, 11, Frederik V vej, 2100 Copenhagen, Denmar
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6
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Müller GJ, Geist MA, Veng LM, Willesen MG, Johansen FF, Leist M, Vaudano E. A role for mixed lineage kinases in granule cell apoptosis induced by cytoskeletal disruption. J Neurochem 2006; 96:1242-52. [PMID: 16478524 DOI: 10.1111/j.1471-4159.2005.03590.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Microtubule disruption by colchicine induces apoptosis in selected neuronal populations. However, little is known about the upstream death signalling events mediating the neurotoxicity. We investigated first whether colchicine-induced granule cell apoptosis activates the c-Jun N-terminal kinase (JNK) pathway. Cultured murine cerebellar granule cells were exposed to 1 microm colchicine for 24 h. Activation of the JNK pathway was detected by western blotting as well as immunocytochemistry using antibodies against phospho-c-Jun (p-c-Jun). Next, adult male rats were injected intracerebroventricularly with colchicine (10 microg), and JNK pathway activation in dentate granule cells (DGCs) was detected by antibodies against p-c-Jun. The second part of the study tested the involvement of mixed lineage kinases (MLK) as upstream activators of the JNK pathway in colchicine toxicity, using CEP-1347, a potent MLK inhibitor. In vitro, significant inhibition of the JNK pathway, activated by colchicine, was achieved by 100-300 nm CEP-1347, which blocked both activation of cell death proteases and apoptosis. Moreover, CEP-1347 markedly delayed neurite fragmentation and cell degeneration. In vivo, CEP-1347 (1 mg/kg) significantly prevented p-c-jun increase following injection of colchicine, and enhanced survival of DGCs. We conclude that colchicine-induced neuronal apoptosis involves the JNK/MLK pathway, and that protection of granule cells can be achieved by MLK inhibition.
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Müller GJ, Stadelmann C, Bastholm L, Elling F, Lassmann H, Johansen FF. Ischemia leads to apoptosis--and necrosis-like neuron death in the ischemic rat hippocampus. Brain Pathol 2005; 14:415-24. [PMID: 15605989 PMCID: PMC8095808 DOI: 10.1111/j.1750-3639.2004.tb00085.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Morphological evidence of apoptosis in transient forebrain ischemia is controversial. We therefore investigated the time sequence of apoptosis-related antigens by immunohistochemistry and correlated it with emerging nuclear patterns of cell death in a model of transient forebrain ischemia in CA1 pyramidal cells of the rat hippocampus. The earliest ischemic changes were found on day 2 and 3, reflected by an upregulation of phospho-c-Jun in a proportion of morphologically intact CA1 neurons, which matched the number of neurons that succumbed to ischemia at later time points. At day 3 and later 3 ischemic cell death morphologies became apparent: pyknosis, apoptosis-like cell death and necrosis-like cell death, which were confirmed by electron microscopy. Activated caspase-3 was present in the vast majority of cells with apoptosis-like morphology as well as in a small subset of cells undergoing necrosis; its expression peaked on days 3 to 4. Silver staining for nucleoli, which are a substrate for caspase-3, revealed a profound loss of nucleoli in cells with apoptosis-like morphology, whereas cells with necrosis-like morphology showed intact nucleoli. Overall, cells with apoptosis-like morphology and/or caspase-3 expression represented a minor fraction (<10%) of ischemic neurons, while the vast majority followed a necrosis-like pathway. Our studies suggest that CA1 pyramidal cell death following transient forebrain ischemia may be initiated through c-Jun N-terminal kinase (JNK) pathway activation, which then either follows an apoptosis-like cell death pathway or leads to secondary necrosis.
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Affiliation(s)
| | | | - Lone Bastholm
- Institute of Molecular Pathology, University of Copenhagen, Denmark
| | - Folmer Elling
- Institute of Molecular Pathology, University of Copenhagen, Denmark
| | - Hans Lassmann
- Brain Research Institute, Medical University of Vienna, Austria
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Müller GJ. Paracetamol (acetaminophen) overdose. SADJ 2004; 59:286-7. [PMID: 15537031] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
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9
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Müller GJ. Aspirin, other salicylates and non-steroidal anti-inflammatory agents. SADJ 2004; 59:283. [PMID: 15537029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Affiliation(s)
- G J Müller
- Tygerberg Poison Information Centre, PO Box 19063, Tygerberg, 7505.
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Müller GJ, Møller A, Johansen FF. Stereological cell counts of GABAergic neurons in rat dentate hilus following transient cerebral ischemia. Exp Brain Res 2001; 141:380-8. [PMID: 11715083 DOI: 10.1007/s002210100879] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2001] [Accepted: 08/08/2001] [Indexed: 11/30/2022]
Abstract
We have previously demonstrated a 60-80% ischemic loss of somatostatinergic neurons in the dorsal dentate hilus of the rat. However, several studies have failed to demonstrate ischemic loss of GABAergic neurons in hilus, although one study reports that 96% of the somatostatinergic neurons in the dorsal hilus colocalize GABA. In order to understand this paradox, we have now estimated, using unbiased stereology, the total number of neurons immunohistochemically stained against glutamic acid decarboxylase-65 (GAD65) and GAD67 in the dorsal dentate hilus. Rats were divided into groups subjected to either sham operation (n=8) or 8 min of transient global ischemia during systemic hypotension (n=8) and allowed to survive for 7-9 days. Results from cell counts (mean +/- SD) in sham rats demonstrated that the dorsal hilus contains 9,189+/-3,957 GAD65 neurons and 6,991+/-2,784 GAD67 neurons. After ischemia, corresponding cell counts demonstrated 10,216+/-4,866 GAD65 neurons and 10,119+/-5,906 GAD67 neurons, and these results were not significantly different (P>0.05) from results in sham rats. Power analysis of the t-test informs that losses less than 80% are not significant and reflects the excessive variance in our material. For comparison, we estimated a total of 21% ischemic neuron death in the dorsal hilus on cresyl violet-stained sections from other corresponding sham (n=7) and ischemic rats (n=7). This explains why ischemic loss of hilar GABAergic neurons can only be detected by counts of the vulnerable subpopulation colocalizing somatostatin. Our investigation has demonstrated a surprisingly high variation between rats in a number of GAD-immunopositive neurons located in the dorsal dentate hilus, which is related to variations between the individual rats and neurons in their endogenous GAD expression.
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Affiliation(s)
- G J Müller
- Laboratory of Neuropathology, University of Copenhagen, 11 Frederik V's vej, 2100 Copenhagen, Denmark
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Tytgat J, Debont T, Rostoll K, Müller GJ, Verdonck F, Daenens P, van der Walt JJ, Possani LD. Purification and partial characterization of a 'short' insectotoxin-like peptide from the venom of the scorpion Parabuthus schlechteri. FEBS Lett 1998; 441:387-91. [PMID: 9891977 DOI: 10.1016/s0014-5793(98)01589-0] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A disulfide-rich, low-molecular-mass toxin-like peptide has been isolated from Parabuthus schlechteri venom using gel filtration, ion exchange, and reversed phase chromatography. Partial characterization of this peptide reveals a relationship with four-disulfide bridge proteins belonging to the family of 'short' insectotoxins (44% residue identity). In recognition hereof, the peptide was named PBITx1 (sITx10). Our work also reports on the deduced sequences of two other 'short' insectotoxins from Buthus eupeus, I3 and I4, and it provides a consensus sequence and nomenclature for all known 'short' insectotoxins. Finally, sequence similarities with K+ channel blockers (charybdotoxin, kappa-conotoxin), and a Cl- channel blocker (chlorotoxin) are highlighted.
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Affiliation(s)
- J Tytgat
- Laboratory of Toxicology, University of Leuven, Belgium.
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Debont T, Swerts A, Van der Walt JJ, Müller GJ, Verdonck F, Daenens P, Tytgat J. Comparison and characterization of the venoms of three Parabuthus scorpion species occurring in southern Africa. Toxicon 1998; 36:341-52. [PMID: 9620581 DOI: 10.1016/s0041-0101(97)00099-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Parabuthus transvaalicus, P. granulatus, and P. villosus are three medically important scorpion species occurring in southern Africa which can cause severe envenoming among people. In contrast to many other genera, no data is available on the venom composition of scorpions belonging to the genus Parabuthus. Here we have investigated the components which may contribute to the venomous potential. The constancy of venom composition within each of the three species and between the three species was investigated by means of gel filtration chromatography. The venoms of the three species each were characterized by a constant and typical elution pattern, resulting in a 'gel filtration fingerprint' which allows distinction between each species. It appears that certain components in the venoms are common to either all three species, or to two of the three species. This points to a clear interspecies relationship within the genus. We also describe the isolation and characterization of some of the polypeptide toxins present in the venoms of P. villosus, P. transvaalicus and P. granulatus by means of reversed phase chromatography and screening of the toxic components on voltage-activated potassium and sodium channels. Our results confirm that toxins which inhibit potassium channels and alter sodium channel gating are present in the venoms studied.
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Affiliation(s)
- T Debont
- Laboratory of Toxicology, University of Leuven, Belgium
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Abstract
BACKGROUND AND OBJECTIVE The aim of the present study was to clarify which of the presently available continuous-wave laser systems are best suited for application in stapes surgery. STUDY DESIGN/MATERIALS AND METHODS Isolated human stapes and bovine compact-bone platelets were used to investigate the connections between the parameters of various laser systems and their effects on bone tissue. The purpose was to optimize the laser parameters required to achieve a perforation measuring 500 microns to 600 microns in diameter. Three different laser systems were applied: the argon and CO2 laser in continuous wave (cw) mode and the CO2 laser in superpulse mode. RESULTS The suitability of the argon laser for stapedotomy is doubtful in view of the lower absorption coefficient of the stapes for the argon beam and the considerable influence which the degree of pigmentation of the irradiated medium exerts on its effect with the resultant poor reproducibility of the perforation diameter. The beam of the CO2 laser is far better absorbed at the footplate than that of the argon laser. This results in higher effectivity, lower thermic side effects, and better reproducibility of the perforation. The two modes of the CO2 laser do not show any appreciable differences. CONCLUSION The experimental results presented indicate that the CO2 laser in cw and superpulse mode is the most suitable of the systems now clinically applied in stapes surgery.
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Affiliation(s)
- S Jovanovic
- ENT Department, Benjamin Franklin Medical Center, Free University of Berlin, Germany
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Gannot I, Schründer S, Dror J, Inberg A, Ertl T, Tschepe J, Müller GJ, Croitoru N. Flexible waveguides for Er-YAG laser radiation delivery. IEEE Trans Biomed Eng 1995; 42:967-72. [PMID: 8582726 DOI: 10.1109/10.464370] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Flexible plastic waveguides (FPW) were devised for the delivery of Er-YAG laser radiation. The FPW characteristics were studied under various conditions. In vitro studies were carried out to explore the drilling procedure on extracted teeth and the FPW-tissue mutual effects. The results which were obtained proved that the FPW as a delivery device might be a substitute hand applicator for the pneumatic turbine for drilling in teeth.
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Affiliation(s)
- I Gannot
- Department of Electrical Engineering-Physical Electronics, Faculty of Engineering, Tel-Aviv University, Israel
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Müller GJ, Hoffman BA, Lamprecht JH. Drug and poison information--the Tygerberg experience. S Afr Med J 1993; 83:395-9. [PMID: 8211455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
This report is based on an analysis of 6,411 consultations processed by the Tygerberg Pharmacology and Toxicology Consultation Centre. Seventy-five per cent of the consultations were of a toxicological nature: 47% related to non-drug chemicals, 37% to drugs and 16% to plants and animals. Pesticides utilised in the home environment featured most prominently in the non-drug chemical group, while queries about paracetamol overdose topped the list in the drug group. The most frequent queries in the biological category concerned potentially poisonous plants. Twenty-five per cent of the consultations related to pharmacotherapeutics. Most potentially toxic exposures to non-drug chemicals occurred in the household setting. Contrary to popular belief, few acute pesticide poisonings were encountered as a result of exposures during farming activities. Another important finding was that there is a frustrating lack of reliable and readily available information in respect of potentially toxic ingredients contained in household and industrial preparations. The large number of household exposures high-lights the need for education in the safe storage and usage of non-drug chemicals. Legislation on the inclusion of basic toxicological information and warnings on labels of household and industrial non-drug chemical products should be considered. In addition, the Government should take responsibility for centralizing information on all potentially toxic non-drug chemicals and make this information available to poison centres at all times. It is also imperative that more attention be given to the training of health care professionals in applied pharmacokinetics and toxicology.
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Affiliation(s)
- G J Müller
- Department of Pharmacology, Tygerberg Hospital, Parowvallei, CP
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Müller GJ. Black and brown widow spider bites in South Africa. A series of 45 cases. S Afr Med J 1993; 83:399-405. [PMID: 8211456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Cases of black widow (Latrodectus indistinctus) and brown widow (L. geometricus) spider bites referred to the Tygerberg Pharmacology and Toxicology Consultation Centre from the summer of 1987/88 to the summer of 1991/92 were entered into this series. Of a total of 45 patients, 30 had been bitten by black and 15 by brown widow spiders. It was evident that black widow spider bites caused a more severe form of envenomation than brown widow bites, characterised by generalised muscle pain and cramps, abdominal muscle rigidity, profuse sweating, raised blood pressure and tachycardia. The symptoms and signs of brown widow bites were mild and tended to be restricted to the bite site and surrounding tissues. Conditions which should be considered in the differential diagnosis include cytotoxic spider bite, scorpion sting, snakebite, acute abdominal conditions, myocardial infarction, alcohol withdrawal and organophosphate poisoning. To prevent the development of complications, the administration of black widow spider antivenom is recommended in severe cases because untreated latrodectism could become protracted, without improvement, for several days.
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Affiliation(s)
- G J Müller
- Department of Pharmacology, University of Stellenbosch, Parowvallei, CP
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Müller GJ. Scorpionism in South Africa. A report of 42 serious scorpion envenomations. S Afr Med J 1993; 83:405-11. [PMID: 8211457] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Forty-two cases of serious scorpion envenomation, of which 4 had a fatal outcome, are presented. The clinical profile, differential diagnosis and management of scorpionism are discussed. Most envenomations occurred in the summer months, peaking in January and February. An immediate local burning pain was the most prominent symptom. Systemic symptoms and signs developed within 4 hours of the sting in most instances, characterised by general paraesthesia, hyperaesthesia, muscle pain and cramps. Other striking features included dysphagia, dysarthria and sialorrhoea with varying degrees of loss of pharyngeal reflexes. The blood pressure and the temperature were often raised and the tendon reflexes increased, while motor power was often impaired. In a considerable number of patients the course was complicated by varying degrees of respiratory dysfunction, which tended to be more serious in children. The oustanding feature in children was an extreme form of restlessness characterised by excessive neuromuscular activity. Victims of scorpion sting, particularly in high-risk localities, should be closely observed for 12-24 hours. Children and other high-risk patients should be hospitalised. All patients with symptoms and signs of systemic envenomation should receive antivenom. Parabuthus granulatus (Hemprich & Ehrenberg, 1828) has been identified as the most important venomous species in the western Cape. The antivenom is produced from the venom of the medically less important P. transvaalicus Purcell, 1899. A strong case can therefore be made for the inclusion of P. granulatus venom in the production of a polyvalent antivenom.
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Affiliation(s)
- G J Müller
- Department of Pharmacology, University of Stellenbosch, Parowvallei, CP
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Stolzenburg S, Müller-Stolzenburg N, Kresse S, Müller GJ. [Contact cyclophotocoagulation with the continuous wave Nd:YAG laser with quartz fiber. Optimizing coagulation parameters]. Ophthalmologe 1992; 89:210-7. [PMID: 1303704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Transscleral cyclo-photocoagulation with a cw-Nd:YAG-laser was studied in enucleated porcine eyes with application times of between 10 ms and 1.5 s. Contact coagulation via a quartz fiber (core 600 microns) required about 32% less power to create visible ciliary body coagulation compared to non-contact coagulation via a focusing handpiece. Application of focusing fiber tips led to a further reduction in the coagulation threshold by a factor of 0.6. The energy per laser application required for ciliary body coagulation increased with application time. During contact coagulation using plane fiber tips a pronounced temperature rise was sometimes observed at the fiber tip due to deposits of carbonized tissue with the subsequent risk of scleral damage. In a pilot study five eyes with secondary glaucoma were treated under coagulation conditions found to be optimal (8 W at 0.2 s).
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Müller GJ, Lamprecht JH, Barnes JM, De Villiers RV, Honeth BR, Hoffman BA. Scombroid poisoning. Case series of 10 incidents involving 22 patients. S Afr Med J 1992; 81:427-30. [PMID: 1566220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Scombroid poisoning is a form of ichthyosarcotoxism caused by the consumption of 'spoiled' fish of the dark meat varieties. It can be considered a mild-to-moderate form of 'food poisoning' and it occurs world-wide. Ten incidents, involving 22 patients, were reported to Tygerberg Hospital Pharmacology and Toxicology Consultation Centre in the first quarter of 1990. Cape yellowtail (Seriola lalandii) was involved in all the cases. The presenting symptoms and signs (in order of frequency) were: skin rash, diarrhoea, palpitations, headache, nausea and abdominal cramps, paraesthesia, an unusual taste sensation and breathing difficulties. The patients responded well to anti-histamines and, in most, the condition resolved within 12-24 hours. Although histamine plays an important role in the pathogenesis of scombroid poisoning, the exact mechanism is still unresolved. The condition should be recognised and not confused with a true seafood allergy. Health workers are urged to alert the authorities when outbreaks of suspected cases of scombroid poisoning are encountered in order to establish the possible cause and to prevent further cases.
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Affiliation(s)
- G J Müller
- Department of Pharmacology, University of Stellenbosch, Parowvallei, CP
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Müller-Stolzenburg NW, Müller GJ, Buchwald HJ, Schründer S. UV exposure of the lens during 193-mm excimer laser corneal surgery. Arch Ophthalmol 1990; 108:915-6. [PMID: 2369344 DOI: 10.1001/archopht.1990.01070090017005] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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Müller-Stolzenburg N, Müller GJ. Transmission of 308 nm excimer laser radiation for ophthalmic microsurgery--medical, technical and safety aspects. BIOMED ENG-BIOMED TE 1989; 34:131-8. [PMID: 2667650 DOI: 10.1515/bmte.1989.34.6.131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A surgical system using 308 nm excimer laser radiation transmitted by quartz fibers is described. In-vitro surgery has been performed on the cornea, in the anterior chamber angle, on the lens and in the vitreous with a special application tip for each procedure. Possible damage of ocular structures by 308 nm radiation is discussed. In-vitro experiments showed that UV exposure of intraocular structures sensitive to 308 nm radiation can be reduced by appropriate design of the application tips and by the application of UV absorbing drugs.
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Spruyt LL, Kirsten GF, Parkin DP, Müller GJ, Kriegler A. Therapeutic monitoring as an aid in rationalizing aminoglycoside dosage techniques in the neonate. S Afr Med J 1987; 72:463-5. [PMID: 3660149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
General pharmacokinetic parameters applicable to adults are not suitable in neonatal practice owing to wide interpatient variations in respect of fluid balance, renal clearance and metabolic rates. We attempted to determine whether acceptable blood levels of gentamicin or tobramycin are obtained with dosage regimens and dosage techniques which are generally recommended. Forty neonates receiving aminoglycosides were studied. After administration of the drug as a slow, constant intravenous infusion into the 'Y' connection of the infusion set, peak levels were found to be subtherapeutic. Trough levels were also very low. After administration of the same dose of gentamicin or tobramycin as a bolus into the butterfly connection of the infusion set, however, high therapeutic levels were obtained. We therefore recommend that gentamicin and tobramycin be administered as an intravenous bolus injection and that blood levels be monitored constantly in order to individualize therapy.
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Affiliation(s)
- L L Spruyt
- Department of Pharmacology, University of Stellenbosch, Parowvallei, CP
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Senz R, Berlien HP, Müller GJ, Ringelhan H. [Safety in using lasers in medicine]. BIOMED ENG-BIOMED TE 1987; 32:74-9. [PMID: 3593866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Müller GJ. [Lasers in medicine... yesterday--today--tomorrow]. BIOMED ENG-BIOMED TE 1987; 32:66-8. [PMID: 3593864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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Spruyt LL, Müller GJ, Pienaar ED, Kriegler AB. Organophosphate alert. S Afr Med J 1986; 69:409. [PMID: 2421420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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Eberhagen D, Müller GJ, Plette G, Wiedemann B. [In vitro studies of lipid metabolism in the stimulated rat adrenal gland. 5]. Hoppe Seylers Z Physiol Chem 1971; 352:683-8. [PMID: 4325501] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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