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Bachmann D, Krekeler H, Steinrötter H, Wirtz R. Verfahrenstechnische Probleme bei der Entwicklung der Hochtemperatur-Pyrolyse. CHEM-ING-TECH 2004. [DOI: 10.1002/cite.330370905] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Barghorn A, Komminoth P, Bachmann D, Rütimann K, Saremaslani P, Muletta-Feurer S, Perren A, Roth J, Heitz PU, Speel EJ. Deletion at 3p25.3-p23 is frequently encountered in endocrine pancreatic tumours and is associated with metastatic progression. J Pathol 2001; 194:451-8. [PMID: 11523053 DOI: 10.1002/path.886] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
For several reasons, chromosome 3p is thought to be involved in the pathogenesis of sporadic endocrine pancreatic tumours (EPTs): von Hippel-Lindau's disease (VHL gene at 3p25.5) is associated with EPTs; 3p is frequently involved in solid human tumours; and comparative genomic hybridization has identified frequent losses at 3p in EPTs. This study investigated 99 benign and malignant tumours, including 20 metastases, from 82 patients, by microsatellite loss of heterozygosity (LOH) analysis and fluorescence in situ hybridization (FISH) in order to evaluate the importance of chromosome 3p deletions in the molecular pathogenesis and biological behaviour of EPTs, to elaborate a common region of deletion, and to narrow down putative tumour suppressor gene loci. Allelic losses of 3p were found in 58/99 (58.6%) of tumours in 45/82 (54.9%) patients; analysis of seven microsatellite markers (3p26-p21) revealed a common region of LOH at 3p25.3-p23. The LOH frequency was significantly higher in malignant than in benign neoplasms (70.2% versus 28.0%; p=0.001). In addition, a strong correlation was found between the loss of alleles on chromosome 3p and clinically metastatic disease (LOH of 73.7% in metastasizing versus 41.5% in non-metastasizing tumours; p=0.008). EPTs from these patients showed a tendency towards losing large parts or the entire short arm of chromosome 3 with tumour progression. Furthermore, FISH analysis revealed complete loss of chromosome 3 in ten out of 37 EPTs (27%). These results indicate that a putative tumour suppressor gene at 3p25.3-p23 may play a role in the oncogenesis of sporadic EPTs and that losses of larger centromeric regions are associated with metastatic progression.
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Pfenninger J, Bachmann D, Wagner BP. Survivors with bad outcome after hypoxic-ischaemic encephalopathy: full-term neonates compare unfavourably with children. Swiss Med Wkly 2001; 131:267-72. [PMID: 11452865 DOI: 10.4414/smw.2001.09717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
UNLABELLED Hypoxic-ischaemic encephalopathy (HIE) is of major importance in neonatal and paediatric intensive care with regard to mortality and long-term morbidity. Our aim was to analyse our data in full-term neonates and children with special regard to withdrawal of life support and bad outcome. PATIENTS All patients with HIE admitted to our unit from 1992-96 were analysed. Criteria for HIE were presence of a hypoxic insult followed by coma or altered consciousness with or without convulsions. Severity of HIE was assessed in neonates using Sarnat stages, and in children the duration of coma. In the majority of cases staging was completed with electrophysiological studies. Outcome was described using the Glasgow Outcome Scale. Bad outcome was defined as death, permanent vegetative state or severe disability, good outcome as moderate disability or good recovery. RESULTS In the neonatal group (n = 38) outcome was significantly associated with Sarnat stages, presence of convulsions, severely abnormal EEG, cardiovascular failure, and multiple organ dysfunction (MOD). A bad outcome was observed in 27 cases with 14 deaths and 13 survivors. Supportive treatment was withdrawn in 14 cases with 9 subsequent deaths. In the older age group (n = 45) outcome was related to persistent coma of 24-48 h, severely abnormal EEG, cardiovascular failure, liver dysfunction and MOD. A bad outcome was found in 36 cases with 33 deaths and 3 survivors. Supportive treatment was withdrawn in 15 instances, all followed by death. CONCLUSIONS Overall, neonates and older patients did not differ with regard to good or bad outcome. However, in the neonatal group there were significantly more survivors with bad outcome, either overall or after withdrawal of support. Possible explanations for this difference include variability of hypoxic insult, maturational and metabolic differences, and the more compliant neonatal skull, which prevents brainstem herniation.
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Pfenninger J, Bachmann D, Wagner BP. Survivors with bad outcome after hypoxic-ischaemic encephalopathy: full-term neonates compare unfavourably with children. Swiss Med Wkly 2001; 131:267-72. [PMID: 11452865 DOI: 2001/19/smw-09717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
UNLABELLED Hypoxic-ischaemic encephalopathy (HIE) is of major importance in neonatal and paediatric intensive care with regard to mortality and long-term morbidity. Our aim was to analyse our data in full-term neonates and children with special regard to withdrawal of life support and bad outcome. PATIENTS All patients with HIE admitted to our unit from 1992-96 were analysed. Criteria for HIE were presence of a hypoxic insult followed by coma or altered consciousness with or without convulsions. Severity of HIE was assessed in neonates using Sarnat stages, and in children the duration of coma. In the majority of cases staging was completed with electrophysiological studies. Outcome was described using the Glasgow Outcome Scale. Bad outcome was defined as death, permanent vegetative state or severe disability, good outcome as moderate disability or good recovery. RESULTS In the neonatal group (n = 38) outcome was significantly associated with Sarnat stages, presence of convulsions, severely abnormal EEG, cardiovascular failure, and multiple organ dysfunction (MOD). A bad outcome was observed in 27 cases with 14 deaths and 13 survivors. Supportive treatment was withdrawn in 14 cases with 9 subsequent deaths. In the older age group (n = 45) outcome was related to persistent coma of 24-48 h, severely abnormal EEG, cardiovascular failure, liver dysfunction and MOD. A bad outcome was found in 36 cases with 33 deaths and 3 survivors. Supportive treatment was withdrawn in 15 instances, all followed by death. CONCLUSIONS Overall, neonates and older patients did not differ with regard to good or bad outcome. However, in the neonatal group there were significantly more survivors with bad outcome, either overall or after withdrawal of support. Possible explanations for this difference include variability of hypoxic insult, maturational and metabolic differences, and the more compliant neonatal skull, which prevents brainstem herniation.
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Schüpbach J, Bachmann D, Hotz MA. [Epiglottitis--a pediatric disease?]. SCHWEIZERISCHE MEDIZINISCHE WOCHENSCHRIFT 2001; Suppl 125:35S-37S. [PMID: 11141935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Abstract
Epiglottitis, commonly described as a paediatric disease, also occurs in adults. Early diagnosis and immediate treatment are crucial because of the rapid and possibly lethal course of upper airway obstruction due to swelling. Initial treatment consists in securing the upper airway and in antibiotic treatment. Streptococci and, especially in children, Haemophilus influenzae b are the most common bacteria. Our study focused on clinical and epidemiological changes since children started to be vaccinated against Haemophilus influenzae b in Switzerland (1992). We reviewed patient histories of 31 adults and 88 children who were hospitalised with epiglottitis at the University Hospital of Berne between 1989 and 1999. Our findings show that the incidence of epiglottitis in children, a clinically, epidemiologically and bacteriologically homogeneous disease, has dramatically decreased. Epiglottitis in adults presents as a more heterogeneous disease without change since the beginning of the vaccination programme. Due to the variety of germs it is impossible to recommend vaccination for adults against Haemophilus influenzae b.
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Immer FF, Stocker F, Seiler AM, Pfammatter JP, Bachmann D, Printzen G, Carrel T. Troponin-I for prediction of early postoperative course after pediatric cardiac surgery. J Am Coll Cardiol 1999; 33:1719-23. [PMID: 10334448 DOI: 10.1016/s0735-1097(99)00061-3] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
OBJECTIVES It was the aim of the study to test the prognostic value of cardiac troponin-I (cTnI) concerning the early postoperative course after pediatric cardiac surgery. BACKGROUND Cardiac troponin-I is a very specific and sensitive marker of myocardial damage in adults and children. As perioperative myocardial damage may be a significant factor of postoperative cardiac performance, serial cTnI values were analyzed in children undergoing open heart surgery. METHODS Seventy-three children undergoing elective correction of congenital heart disease including atrial and ventricular surgical manipulation were studied. Cardiac troponin-I levels were measured serially and correlated with intra- and postoperative parameters (such as doses and length of inotropic support, renal and hepatic function, duration of intubation). Patients with prolonged postoperative recovery were analyzed with special attention to the cTnI levels. RESULTS The cutoff point for the definition of a high and a low risk group of cTnI values was set at 25 microg/liter, 4 h after admission to the intensive care unit (ICU) and at 35 microg/liter considering the maximal value of cTnI in the first 24 h in the ICU. The results showed a highly significant correlation between the need for inotropic support, the severity of renal dysfunction and the duration of intubation in relation to the serum levels of cTnI. CONCLUSIONS Cardiac troponin-I serum levels after open heart surgery in children and infants 4 h after admission to the ICU allowed anticipation of the postoperative course and correlated with the incidence of significant postoperative complications.
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Michetti P, Kreiss C, Kotloff KL, Porta N, Blanco JL, Bachmann D, Herranz M, Saldinger PF, Corthésy-Theulaz I, Losonsky G, Nichols R, Simon J, Stolte M, Ackerman S, Monath TP, Blum AL. Oral immunization with urease and Escherichia coli heat-labile enterotoxin is safe and immunogenic in Helicobacter pylori-infected adults. Gastroenterology 1999; 116:804-12. [PMID: 10092302 DOI: 10.1016/s0016-5085(99)70063-6] [Citation(s) in RCA: 219] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
BACKGROUND & AIMS Oral immunization with Helicobacter pylori urease can cure Helicobacter infection in animals. As a step toward therapeutic immunization in humans, the safety and immunogenicity of oral immunization with recombinant H. pylori urease were tested in H. pylori-infected adults. METHODS Twenty-six H. pylori-infected volunteers were randomized in a double-blind study to four weekly oral doses of 180, 60, or 20 mg of urease with 5 microg heat-labile enterotoxin of Escherichia coli (LT), LT alone, or placebo. Side effects and immune responses were evaluated weekly after immunization, and gastric biopsy specimens were obtained after 1 month and 6 months for histology and quantitative cultures. RESULTS Diarrhea was noted in 16 of 24 (66%) of the volunteers who completed the study. Antiurease serum immunoglobulin A titers increased 1. 58-fold +/- 0.37-fold and 3.66-fold +/- 1.5-fold (mean +/- SEM) after immunization with 60 and 180 mg urease, respectively, whereas no change occurred in the placebo +/- LT groups (P = 0.005). Circulating antiurease immunoglobulin A-producing cells increased in volunteers exposed to urease compared with placebo (38.9 +/- 13. 6/10(6) vs. 5.4 +/- 3.1; P = 0.018). Eradication of H. pylori infection was not observed, but urease immunization induced a significant decrease in gastric H. pylori density. CONCLUSIONS H. pylori urease with LT is well tolerated and immunogenic in H. pylori-infected individuals. An improved vaccine formulation may induce curative immunity.
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Kapral S, Gollmann G, Bachmann D, Prohaska B, Likar R, Jandrasits O, Weinstabl C, Lehofer F. The effects of thoracic epidural anesthesia on intraoperative visceral perfusion and metabolism. Anesth Analg 1999; 88:402-6. [PMID: 9972765 DOI: 10.1097/00000539-199902000-00034] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
UNLABELLED After institutional approval and informed consent, we studied the effect of epidural bupivacaine 0.5% on visceral perfusion and metabolism by using gastric mucosal tonometry in 30 patients in a placebo-controlled fashion. The maximal intramucosal pH (pHi) decrease was significantly (P < 0.001) greater in the control group (0.16 +/- 0.04) than in the thoracic epidural anesthesia (TEA) group (0.07 +/- 0.05). There were 10 patients in the control group and 2 patients in the TEA group who had evidence of gastric mucosal ischemia (pHi <7.32) at the end of the study (P< 0.01). The differences in pHi and intramucosal CO2 (PiCO2) became statistically significant between the groups after 180 and 240 min. The study data show that TEA prevents the decrease of pHi during major abdominal surgery, perhaps as an effect of stable visceral perfusion. We conclude that TEA may be a valuable method for intra- and postoperative treatment of surgical stress. IMPLICATIONS The present study shows that thoracic epidural anesthesia prevents a decrease of intramucosal pH during major abdominal surgery, which suggests that thoracic epidural anesthesia may be a valuable tool for the treatment of surgical stress.
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Tönz M, Bachmann D, Mettler D, Kaiser G. Pulmonary function after one-lung ventilation in newborns: the basis for neonatal thoracoscopy. Ann Thorac Surg 1998; 66:542-6. [PMID: 9725400 DOI: 10.1016/s0003-4975(98)00453-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
BACKGROUND To maintain good exposure during major video-assisted thoracic surgery it is necessary to deflate completely the ipsilateral lung. However, little is known about the effects of one-lung ventilation (OLV) on pulmonary function in newborn patients. METHODS Ten neonatal domestic pigs with a mean age of 6+/-0.6 days were intubated and ventilated in pressure-controlled mode (inspired oxygen fraction=1.0). One-lung ventilation was maintained for 120 minutes. Serial measurements of hemodynamics and gas exchange were done before, during, and until 90 minutes after OLV. Pulmonary function testing was performed before and after OLV for each lung separately. RESULTS With the inspired oxygen fraction set at 1.0, arterial oxygen saturation remained stable at 100% during OLV. Venous admixture and alveolar-arterial oxygen tension gradient increased slightly from the baseline value of 2.6% +/-0.3% to 3.8%+/-0.3% during OLV (mean+/-standard error of the mean; p=0.02), and from 358+/-28 to 407+/-18 mm Hg (not significant), respectively. Both values returned to baseline during the subsequent ventilation of both lungs. Static compliance and resistance of the ventilated lung did not change. Compliance of the collapsed lung decreased after reexpansion from 0.42+/-0.07 to 0.29+/-0.06 mL x cm H2O(-1) x kg(-1), p=0.008). Resistance remained unchanged (0.22+/-0.02 versus 0.25+/-0.05 cm H2O x L(-1) x s(-1); not significant). CONCLUSIONS There were only minor effects on pulmonary function during and after OLV in the neonatal piglet. Alterations in gas exchange during OLV were minimal. Prolonged collapse of the lung with subsequent reexpansion was associated with a slight decrease in compliance, indicating some mild lung injury.
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Corthésy-Theulaz IE, Hopkins S, Bachmann D, Saldinger PF, Porta N, Haas R, Zheng-Xin Y, Meyer T, Bouzourène H, Blum AL, Kraehenbuhl JP. Mice are protected from Helicobacter pylori infection by nasal immunization with attenuated Salmonella typhimurium phoPc expressing urease A and B subunits. Infect Immun 1998; 66:581-6. [PMID: 9453612 PMCID: PMC113500 DOI: 10.1128/iai.66.2.581-586.1998] [Citation(s) in RCA: 100] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/1997] [Accepted: 11/28/1997] [Indexed: 02/06/2023] Open
Abstract
Live Salmonella typhimurium phoPc bacteria were tested as mucosal vaccine vectors to deliver Helicobacter pylori antigens. The genes encoding the A and B subunits of H. pylori urease were introduced into S. typhimurium phoPc and expressed under the control of a constitutive tac promoter (tac-ureAB) or a two-phase T7 expression system (cT7-ureAB). Both recombinant Salmonella strains expressed the two urease subunits in vitro and were used to nasally immunize BALB/c mice. The plasmid carrying cT7-ureAB was stably inherited by bacteria growing or persisting in the spleen, lungs, mesenteric or cervical lymph nodes, and Peyer's patches of immunized mice, while the plasmid carrying tac-ureAB was rapidly lost. Spleen and Peyer's patch CD4+ lymphocytes from mice immunized with S. typhimurium phopc cT7-ureAB proliferated in vitro in response to urease, whereas cells from mice given S. typhimurium phoPc alone did not. Splenic CD4+ cells from mice immunized with phoPc cT7-ureAB secreted gamma interferon and interleukin 10, while Peyer's patch CD4+ cells did not secrete either cytokine. Specific H. pylori anti-urease immunoglobulin G1 (IgG1) and IgG2A antibodies were detected following immunization, confirming that both Th1- and Th2-type immune responses were generated by the live vaccine. Sixty percent of the mice (9 of 15) immunized with S. typhimurium phoPc cT7-ureAB were found to be resistant to infection by H. pylori, while all mice immunized with phoPc tac-ureAB (15 of 15) or phoPc (15 of 15) were infected. Our data demonstrate that H. pylori urease delivered nasally by using a vaccine strain of S. typhimurium can trigger Th1- and Th2-type responses and induce protective immunity against Helicobacter infection.
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Corthésy-Theulaz IE, Bergonzelli GE, Henry H, Bachmann D, Schorderet DF, Blum AL, Ornston LN. Cloning and characterization of Helicobacter pylori succinyl CoA:acetoacetate CoA-transferase, a novel prokaryotic member of the CoA-transferase family. J Biol Chem 1997; 272:25659-67. [PMID: 9325289 DOI: 10.1074/jbc.272.41.25659] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Sequencing of a fragment of Helicobacter pylori genome led to the identification of two open reading frames showing striking homology with Coenzyme A (CoA) transferases, enzymes catalyzing the reversible transfer of CoA from one carboxylic acid to another. The genes were present in all H. pylori strains tested by polymerase chain reaction or slot blotting but not in Campylobacter jejuni. Genes for the putative A and B subunits of H. pylori CoA-transferase were introduced into the bacterial expression vector pKK223-3 and expressed in Escherichia coli JM105 cells. Amino acid sequence comparisons, combined with measurements of enzyme activities using different CoA donors and acceptors, identified the H. pylori CoA-transferase as a succinyl CoA:acetoacetate CoA-transferase. This activity was consistently observed in different H. pylori strains. Antibodies raised against either recombinant A or B subunits recognized two distinct subunits of Mr approximately 26,000 and 24, 000 that are both necessary for H. pylori CoA-transferase function. The lack of alpha-ketoglutarate dehydrogenase and of succinyl CoA synthetase activities indicates that the generation of succinyl CoA is not mediated by the tricarboxylic acid cycle in H. pylori. We postulate the existence of an alternative pathway where the CoA-transferase is essential for energy metabolism.
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Tönz M, Bachmann D, Mettler D, Kaiser G. Effects of one-lung ventilation on pulmonary hemodynamics and gas exchange in the newborn. Eur J Pediatr Surg 1997; 7:212-5. [PMID: 9297515 DOI: 10.1055/s-2008-1071095] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
For major thoracoscopic surgery, one-lung ventilation is mandatory. This is reasonably well tolerated in adults and children. The effects of one-lung ventilation on hemodynamics and gas exchange in newborns, however, are not known yet. Eight neonatal domestic pigs with a median age of 6 days (range: 3-9 days), and a mean body weight of 2.3 kg (1.7-2.8 kg) were intubated and ventilated in pressure-controlled mode (FIO2 = 1). Anesthesia was maintained with i.v. fentanyl/metomidate. After tracheotomy an endotracheal tube was positioned in the trachea, and a second tube in the left mainstem bronchus. One-lung ventilation was maintained for 120 min. Serial measurements were done before, during, and until 90 min. after one-lung ventilation. During one-lung ventilation, pulmonary artery pressure and intrapulmonary shunt increased from 15 +/- 1 to 18 +/- 1 mmHg (p = 0.004), and from 2.6 +/- 0.3 to 3.7 +/- 0.4% (p = 0.02), respectively. Arterial oxygen saturation remained unchanged at 100%. A slight increase in arterial PCO2 could easily be treated by increasing the respiratory rate. In conclusion, one-lung ventilation was not associated with major side effects in regard to hemodynamics and gas exchange in the neonatal pig.
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Brandl M, Tardi C, Drechsler M, Bachmann D, Reszka R, Bauer K, Schubert R. Three-dimensional liposome networks: freeze fracture electron microscopical evaluation of their structure and in vitro analysis of release of hydrophilic markers. Adv Drug Deliv Rev 1997. [DOI: 10.1016/s0169-409x(96)00455-3] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Abstract
The antiepileptic drug vigabatrin has shown efficacy in the treatment of patients with refractory epilepsy. Unlike many other antiepileptics it is not bound to plasma protein and mainly eliminated by the kidney. Although the therapeutic and toxic serum concentration range is not clearly defined and efficacy and toxicity are not closely correlated with the dose, factors decreasing vigabatrin elimination such as advanced age or renal failure may pose risk of untoward effects. Thus far there are no dose recommendations available for patients on haemodialysis. We report on an epileptic patient who experienced severe, partially reversible renal failure as a consequence of near-drowning. In this patient serum concentrations of vigabatrin were measured repeatedly both during haemodialysis and after partial recovery of renal function. The terminal elimination half-life in this patient was 41 hours during the period of severe renal failure (creatinine clearance < 5 ml/min). As about 60% of vigabatrin was removed from the blood pool by haemodialysis in these patients the antiepileptic should be administered after dialysis. To maintain serum concentrations in the usual range and to control seizure activity only 500 mg vigabatrin every 3 days were necessary.
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Cavalli G, Bachmann D, Thoma F. Inactivation of topoisomerases affects transcription-dependent chromatin transitions in rDNA but not in a gene transcribed by RNA polymerase II. EMBO J 1996; 15:590-7. [PMID: 8599942 PMCID: PMC449977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Previous studies on a chromatin reporter gene (GAL-URARIB) in yeast showed that nucleosomes were maintained but rearranged during transcription in galactose, which was consistent with local dissociation of histones at the site of the RNA polymerase. Furthermore, repositioning of nucleosomes occurred rapidly after glucose repression. Because nucleosomal disruption and transcription produce topological changes in the chromatin substrate, the effect of topoisomerase activity was tested by the insertion of GAL-URABIB in topoisomerase mutant strains. The chromatin structure was analysed by nuclease digestion and psoralen crosslinking, and compared with that of the rDNA locus. In GAL-URARIB, neither the inactivation of topoisomerases I, II or I and II generated nucleosomal loss during transcription, nor was topoisomerase activity required for repositioning of the nucleosomes after repression. In contrast, the inactivation of topoisomerase I promoted an enhanced psoralen accessibility of the transcribed rDNA, possibly because of altered supercoiling, and the inactivation of topoisomerases I and II disrupted the chromatin structure of the whole rDNA locus by redistribution of the nucleosomes. The inactivation of topoisomerase II alone had no effect. These observations substantiate a differential participation of topoisomerases in the modulation of the chromatin structures of rDNA genes and of a single copy polymerase II gene. It is suggested that topological stress in genes transcribed by RNA polymerase II might diffuse away into flanking regions.
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Cavalli G, Bachmann D, Thoma F. Inactivation of topoisomerases affects transcription-dependent chromatin transitions in rDNA but not in a gene transcribed by RNA polymerase II. EMBO J 1996. [DOI: 10.1002/j.1460-2075.1996.tb00391.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Pfammatter JP, Paul T, Bachmann D, Weber JW, Stocker FP, Kallfelz HC. [Therapeutic efficacy and diagnostic potential of adenosine in infants and children]. ZEITSCHRIFT FUR KARDIOLOGIE 1995; 84:243-9. [PMID: 7732718] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
In an open study a total of 53 episodes of supraventricular reentrant tachycardia in 31 infants and children were treated with intravenous adenosine at two centers. Adenosine was given as a rapid intravenous bolus injection beginning with a dose of 0.1 mg/kg. If there was persistence of the dysrhythmia dosage was increased in 0.05 mg/kg-steps up to a maximum dose of 0.3 mg/kg if necessary. The median dose required for successful termination of the tachycardias was 0.15 mg/kg. In 26 patients with 48 episodes of regular narrow-QRS-complex tachycardia adenosine was used as the therapeutic agent of first choice. In all patients a shortlasting atrioventricular block occurred within seconds after the administration of adenosine. In 42 of 48 episodes of tachycardia (87%) the dysrhythmias were converted to a stable sinus rhythm. In six episodes (13%) recurrence of the tachycardia was observed immediately. In five children adenosine was used for diagnostic purpose: in three children with wide-QRS-complex tachycardia successful termination with adenosine proved the supraventricular origin of the dysrhythmia. In two children with suspected atrial flutter adenosine-induced atrioventricular block allowed identification of flutter waves in one patient while in the other patient no effect of adenosine was seen. Side-effects such as flush, chest-pain or abdominal pain were frequent but mild and only of a few seconds' duration. No influence of adenosine on blood pressure was noted. Only in one child with previously unknown sinus node dysfunction was a relevant electrophysiologic side effect seen: a prolonged sinus arrest with asystole of 12 seconds' duration occurred after adenosine administration.(ABSTRACT TRUNCATED AT 250 WORDS)
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Lutz J, Augustin AJ, Jäger LJ, Bachmann D, Brandl M. Acute toxicity and depression of phagocytosis in vivo by liposomes: influence of lysophosphatidylcholine. Life Sci 1995; 56:99-106. [PMID: 7823764 DOI: 10.1016/0024-3205(94)00419-s] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Small unilamellar phospholipid vesicles (liposomes), intended as drug carriers, have recently been demonstrated to reversibly depress phagocytic activity in rats when injected in a single high dose (2g of lipid per kg body weight) as revealed by the carbon clearance test. Depression of the phagocytic function was found to vary widely depending on the lipid used [M. Brandl et al., Pharm. Pharmacol. Lett., 4 (1) 1-4, 1994]. This study has now been extended in two directions: Firstly, liposomes made of the same type of lipid but different batches of raw material were compared in terms of their influence on phagocytosis as well as for their contents of impurities. The test revealed great variability of RES suppression between different batches of hydrogenated soy PC, whereas the reproducibility of the carbon clearance test was satisfactory with liposomes made of a single batch of raw material. Thin layer chromatographic analyses of the used phosphatidylcholines (PCs) and limulus tests on lipopolysaccharides revealed lysophosphatidylcholine (lysoPC) as the only impurity which showed parallels with the observed differences in phagocytosis. Secondly by "spiking" phosphatidylcholine with increasing amounts of lysoPC the latter could be proven to enhance RES depression by liposomes in a dose-dependent manner. At the same time a strong and dose-limiting increase in acute toxicity of PC vesicles was observed with increasing contents of lysoPC. However, in cholesterol-containing vesicles lysoPC-spiking did not significantly alter their behaviour, for lysoPC contents of up to 10%. Only PC/cholesterol-vesicles containing lysoPC contents as high as 15% provoked enhanced RES depression and toxicity compared to lysoPC-free vesicles. LysoPC and cholesterol in liposomes are known to play a destabilizing and stabilizing role respectively within liposomal bilayers which might influence recognition and uptake of vesicles by macrophages and thus modulation of phagocytosis.
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Keppler D, Waridel P, Abrahamson M, Bachmann D, Berdoz J, Sordat B. Latency of cathepsin B secreted by human colon carcinoma cells is not linked to secretion of cystatin C and is relieved by neutrophil elastase. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1226:117-25. [PMID: 8204657 DOI: 10.1016/0925-4439(94)90018-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
The lysosomal cysteine proteinase cathepsin B is shown to be secreted by ten human colon carcinoma cell lines and to accumulate in culture media as a latent enzyme. The cell lines also secrete a physiological inhibitor of cathepsin B, cystatin C. A significant correlation was found between secretion of the latent enzyme and the inhibitor (r = 0.755, P < 0.01). The aim of the present study was to modulate the respective secretion of the two antagonists to test whether or not latency of cathepsin B was due to the concomitant secretion of the inhibitor. SW480 colon carcinoma cells were treated with the acidotropic agent ammonium chloride, phorbol 12-myristate 13-acetate, and the inflammatory cytokines TGF-beta, TNF-alpha, and IL-1 beta. Ammonium chloride significantly increased latent cathepsin B levels without affecting the constitutive secretion of cystatin C. Phorbol 12-myristate 13-acetate induced a 4- to 5-fold increase in secreted latent cathepsin B, but did not alter significantly the accumulation of cystatin C in media. The cytokines, TGF-beta, TNF-alpha, and IL-1 beta, had no major effect on the expression of these two antagonists. Latent cathepsin B released from human carcinoma cells could be efficiently activated by neutrophil elastase at neutral pH. It is concluded that latent cathepsin B is a true proenzyme rather than an enzyme-inhibitor complex. In addition, our data from neutrophil elastase activation experiments indicate that a proteolytic system for activation of the tumor cell-secreted latent enzyme may exist in vivo.
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Huang GS, Bachmann D, Taylor JA, Marcelis S, Haghighi P, Resnick D. Calcium pyrophosphate dihydrate crystal deposition disease and pseudogout of the acromioclavicular joint: radiographic and pathologic features. J Rheumatol 1993; 20:2077-82. [PMID: 8014936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
OBJECTIVE To correlate the radiographic and pathologic findings in calcium pyrophosphate dihydrate (CPPD) crystal deposition disease and the pseudogout syndrome in the acromioclavicular (AC) joint, a relatively infrequent, but clinically important site. METHODS We describe a case with a definite diagnosis of CPPD crystal deposition leading to pseudogout of the AC joint. We also identified 17 other patients with CPPD crystal deposition disease who showed intraarticular or periarticular calcification in this joint and investigated the radiographic findings in 26 AC joints in these 17 patients. We then correlated the results with the pathologic findings in 2 cadavers with AC joint manifestations of the disease. RESULTS Intradiscal calcification, mainly linear or punctate in configuration, was found between adjacent bony margins in 9 of 26 AC joints (35%) or between the bony margins and extending above the upper articular bony margin in 14 AC joints (54%). Two joints (8%) showed diffuse calcification within the discs between, above, and below the articular bony margins. The remaining joint (3%) had intradiscal calcification only above the upper bony margins of the AC joint. All the joints with calcifications above the articular margins had associated globular or tumor-like soft tissue masses. A pseudogout attack at the AC joint may have nonspecific shoulder pain as its presenting symptom. CONCLUSION CPPD crystal deposition disease leading to pseudogout syndrome of the AC joint is a clinically significant condition. We emphasize that careful assessment of the AC joint and adjacent soft tissue using intensive bright light on routine shoulder radiographs may increase the sensitivity of detecting discal and capsular calcifications in patients with pseudogout of the shoulder.
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Pfenninger J, Aebi C, Bachmann D, Wagner BP. Lung mechanics and gas exchange in ventilated preterm infants during treatment of hyaline membrane disease with multiple doses of artificial surfactant (Exosurf). Pediatr Pulmonol 1992; 14:10-5. [PMID: 1437337 DOI: 10.1002/ppul.1950140104] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Eight premature infants ventilated for hyaline membrane disease and enrolled in the OSIRIS surfactant trial were studied. Lung mechanics, gas exchange [PaCO2, arterial/alveolar PO2 ratio (a/A ratio)], and ventilator settings were determined 20 minutes before and 20 minutes after the end of Exosurf instillation, and subsequently at 12-24 hour intervals. Respiratory system compliance (Crs) and resistance (Rrs) were measured by means of the single breath occlusion method. After surfactant instillation there were no significant immediate changes in PaCO2 (36 vs. 37 mmHg), a/A ratio (0.23 vs. 0.20), Crs (0.32 vs. 0.31 mL/cm H2O/kg), and Rrs (0.11 vs. 0.16 cmH2O/mL/s) (pooled data of 18 measurement pairs). During the clinical course, mean a/A ratio improved significantly each time from 0.17 (time 0) to 0.29 (time 12-13 hours), to 0.39 (time 24-36 hours) and to 0.60 (time 48-61 hours), although mean airway pressure was reduced substantially. Mean Crs increased significantly from 0.28 mL/cmH2O/kg (time 0) to 0.38 (time 12-13 hours), to 0.37 (time 24-38 hours), and to 0.52 (time 48-61 hours), whereas mean Rrs increased from 0.10 cm H2O/mL/s (time 0) to 0.11 (time 12-13 hours), to 0.13 (time 24-36 hours) and to (time 48-61 hours) with no overall significance. A highly significant correlation was found between Crs and a/A ratio (r = 0.698, P less than 0.001). We conclude that Exosurf does not induce immediate changes in oxygenation as does the instillation of (modified) natural surfactant preparations. However, after 12 and 24 hours of treatment oxygenation and Crs improve significantly.(ABSTRACT TRUNCATED AT 250 WORDS)
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Schaad UB, Bachmann D. [Prospective comparison of miconazole gel and nystatin suspension in the treatment of oral candidiasis]. SCHWEIZERISCHE MEDIZINISCHE WOCHENSCHRIFT 1983; 113:1356-62. [PMID: 6356343] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Miconazole gel and nystatin suspension were compared in a prospective randomised therapeutic trial including 51 cases of oral candidiasis in hospitalised pediatric patients. Clinical evaluations, microscopic examinations and adequate cultures were the basis for diagnosis and follow-up over 3-4 weeks. Miconazole oral gel therapy resulted in an optimal cure rate of 100% and in a relapse rate of only 4%, whereas for nystatin suspension these values were 75% and 22% respectively. However, apart from producing a better effect compared to nystatin suspension, miconazole gel also involved a higher rate of minor gastrointestinal side effects and worse acceptance. Older children often tolerated poorly the sweet taste of miconazole gel. It is recommended that the gel form of the potent antimycotic agent miconazole be mainly used in infants and young children.
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Lombeck I, Kasperek K, Bachmann D, Feinendegen LE, Bremer HJ. Selenium requirements in patients with inborn errors of amino acid metabolism and selenium deficiency. Eur J Pediatr 1980; 134:65-8. [PMID: 7408912 DOI: 10.1007/bf00442405] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The diets of 5 patients with phenylketonuria of maple-syrup-urine disease were supplemented with yeast which was rich in selenium. For 120 days the patients received 45 micrograms Se/day to increase the Se content of their diets to 10--12 ng Se/Kjoule. Before supplementation the selenium content of serum (5--15 ng/ml) and whole blood (10--27 ng/ml), and the activity of the erythrocyte glutathione peroxidase (0.19--2.69 U37/g Hb), amounted to only 10--20% of normal. The serum selenium content reached normal values within 4 weeks of supplementation, followed by normalisation of the selenium content of whole blood within 4--8 weeks. Restoration of the activity of erythrocyte glutathione peroxidase took 9 to 15 weeks--the red cell life span. There was a significant positive correlation between the selenium content of the erythrocytes and the activity of erythrocyte glutathione peroxidase.
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Zimmermann B, Neubert D, Bachmann D, Merker HJ. Induction of skeletal malformations in organ cultures of mouse limb buds. EXPERIENTIA 1975; 31:227-8. [PMID: 1112364 DOI: 10.1007/bf01990719] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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