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Grabow N, Schmohl K, Khosravi A, Philipp M, Scharfschwerdt M, Graf B, Stamm C, Haubold A, Schmitz KP, Steinhoff G. Mechanical and Structural Properties of a Novel Hybrid Heart Valve Scaffold for Tissue Engineering. Artif Organs 2004; 28:971-9. [PMID: 15504112 DOI: 10.1111/j.1525-1594.2004.00007.x] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hybrid heart valve scaffolds were fabricated from decellularized porcine aortic heart valve matrices and enhanced with bioresorbable polymers using different protocols: (i) dip coating of lyophilized decellularized matrices, and (ii) impregnation of wet decellularized matrices. The following polymers were evaluated: poly(4-hydroxybutyrate) and poly(3-hydroxybutyrate-co4-hydroxybutyrate). Tensile tests were conducted to assess the biomechanical behavior of valve leaflet strips. Suture retention strength was evaluated for the adjacent conduit. A pulse duplicator system was used for functional testing of the valves under physiological systemic load conditions. The properties of the hybrid structures were compared with native, decellularized, and glutaraldehyde-fixed specimens. Mechanisms of the polymer impregnation process were studied with IR spectroscopy, fluorescent microscopic imaging, and SEM. Altogether this study demonstrates the feasibility and improved biomechanical function of a novel hybrid heart valve scaffold for an application in tissue engineering.
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Abstract
Nitrous oxide has been used in addition to other volatile anaesthetics to provide general anaesthesia and short time sedation for more than 150 years. However, the exact mechanisms of action remain unclear. For decades nitrous oxide was considered to be the ideal anaesthetic because of his favourable physical properties and low cardiovascular side effects. However, the known side effects of nitrous oxide as well as the implementation of new anaesthetic agents and short acting opiates led to more and more criticism about the administration of this gas. Nitrous oxide is still frequently used for mask induction primarily in paediatric anaesthesia and gynaecology. However, recent studies have shown that omitting nitrous oxide can also be a risk factor because of an increased susceptibility to intraoperative awareness. Careful consideration of the illustrated contraindications and side effects as well as the available alternatives, shows that nitrous oxide is still an option in general anaesthesia.
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Abstract
The following article summarizes different aspects of local anesthetic effects that cannot be explained purely by a sodium channel blockade. Particularly remarkable is hereby their antiinflammatory activity, e.g. the inhibition of pathological changes such as excessive stimulation of the inflammatory system, without compromising the host defense system. In contrast to other immunosuppressive drugs commonly used for treating such conditions, local anesthetics look promising for the future as a new therapeutic option. Besides general anesthetic activity, local anesthetics exert cerebroprotective effects and are furthermore, in consideration of their cardiovascular stability, of interest during neuroanesthetic procedures. In addition, local anesthetics are known for their potency to minimize bronchial hyperreactivity, although details of the underlying mechanisms are not yet elucidated. These effects of local anesthetics may represent interesting prospects for which their relevance has to be determined.
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Verch M, Dollner R, Osswald B, Schweiger P, Graf B, Hagl S. Percutaneous dilatation tracheostomy (PDT) in cardiac surgery patients. Thorac Cardiovasc Surg 2004. [DOI: 10.1055/s-2004-816826] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Pichlmeier E, Böhm H, Graf B, Häfner R, Michels H. Eitrige Spondylodiszitis bei juveniler chronischer Arthritis: Komplikation unter Etanercept-Therapie. AKTUEL RHEUMATOL 2003. [DOI: 10.1055/s-2003-45044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Sievers HH, Dahmen G, Graf B, Stierle U, Ziegler A, Schmidtke C. Midterm results of the Ross procedure preserving the patient's aortic root. Circulation 2003; 108 Suppl 1:II55-60. [PMID: 12970209 DOI: 10.1161/01.cir.0000087443.84392.32] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Since the early 1990s, the pulmonary autograft is predominantly implanted as a freestanding root for less aortic valve regurgitation is reported. However, there is a certain risk of dilatation of the root over time potentially impairing valve function. We favor since 8 years the original subcoronary or inclusion technique to preserve the root of the patient as a restrain to dilatation. METHODS AND RESULTS Between June 1994 and May 2002 the subcoronary (n=228) and inclusion technique (n=17) were performed in 245 patients (191 male, 54 female), mean age 45.7+/-13.4 (15-70) years. The underlying aortic valve disease was an aortic insufficiency in n=83, stenosis in n=48, a combined aortic valve disease in n=111 and an acute endocarditis in n=19 patients. Previous aortic valve surgery was performed in n=23. Last follow-up investigations (within last year) including echocardiography was performed at a mean follow-up of 29.4+/-24.7 months (553.7 patient years). Hospital mortality was n=2, late mortality n=4 (all noncardiac). Two patients were lost to follow-up (99% complete clinical follow-up). Reoperations were necessary in n=7 valves (autograft: endocarditis n=1, malpositioning n=1, leaflet prolapse n=1; homograft: stenosis n=2, insufficiency n=2). Autograft insufficiency (AI) was AI 0 in n=154, AI I n=66, AI II n=8. The maximum/mean pressure gradient across the autograft was 6.6+/-3.4 (2.1 to 25.9)/3.6+/-1.8 (1.2 to 13.2) mm Hg, respectively. Homograft insufficiency was 0 in n=167, I in n=54, II in n=9, and III in n=1. Maximum and mean transhomograft pressure gradients were 11.7+/-6.8 (2.2 to 42.6)/6.2+/-3.8 (1.2 to 24.5) mm Hg. Most patients were NYHA class I (n=214), class II (n=19), class III (n=2). Significant aortic root dilatation was not observed. CONCLUSIONS Aortic valve replacement with a pulmonary autograft in the subcoronary or inclusion technique provides excellent hemodynamics with no root dilatation at least in a mid term postoperative period. Transhomograft pressure gradients are slightly increased. Longer term results with special emphasis on the pulmonary homograft are necessary.
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Schmidtke C, Stierle U, Sievers HH, Graf B. [The Ross procedure (pulmonary autograft) as an alternative for aortic valve replacement]. Dtsch Med Wochenschr 2003; 128:1759-64. [PMID: 12934169 DOI: 10.1055/s-2003-41707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND AND OBJECTIVE The Ross procedure (pulmonary autograft) has since the 1980s attracted growing interest as an alternative to the widely practised insertion of a prosthetic aortic valve. The 12-year experience of a consecutive series from one centre are reported here. PATIENTS AND METHODS Between February 1990 and January 2002 a Ross procedure, predominantly with the subcoronary technique, was performed in 244 consecutive patients with aortic valve disease (244 men, 54 women, mean age 46 +/- 13.5 years). Annual follow-up clinical examinations (mean postoperative period 32.9 +/- 29.5 months in 99 % of the cohort) were performed. RESULTS Perioperative mortality was 0.8 % (n=2), and there were two late deaths unrelated to the aortic valve disease. Seven patients had to be re-operated for failure of the homograft (n=4) or autograft (n=4). According to clinical criteria, 99 % of the followed-up patients were in New York Heart Association (NYHA) functional class I or II, only two patients, with pulmonary comorbidity, were in class III. Echocardiography demonstrated autografts with nearly normal transvalvular gradient (mean maximal pressure gradient 6.5 +/- 3.3 mmHg), while nine patients had second-degree aortic regurgitation. The mean maximal gradient across the homograft valve in the pulmonary position was 12.0 +/- 6.9 mmHg, while ten patients had second-degree and one had third-degree pulmonary regurgitation. CONCLUSION The technically demanding Ross procedure produced excellent clinical and hemodynamic mid-term results. It is thus an appealing alternative to the widely used replacement by a prosthetic valve. Definitive assessment awaits further long-term follow-up.
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Dollner R, Verch M, Schweiger P, Graf B, Wallner F. Long-term outcome after Griggs tracheostomy. THE JOURNAL OF OTOLARYNGOLOGY 2002; 31:386-9. [PMID: 12593553 DOI: 10.2310/7070.2002.34489] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The purpose of this study was to evaluate laryngotracheal stenoses in the long-term outcome after percutaneous tracheostomy. METHODS Between 1997 and 2000, 162 patients were tracheostomized during their postoperative stay at the intensive care unit of the Department of Cardiac Surgery, University of Heidelberg. Thirty-eight of 80 long-term surviving patients (mean follow-up: 22 months, range: 7-50 months) gave their informed consent to follow-up laryngotracheoscopy. By using this technique, we localized the tracheostomy site, evaluated the laryngotracheal morphology, and quantified laryngotracheal stenosis planimetrically. RESULTS Clinically relevant stenoses were found in one patient. Another patient had undergone surgical revision of the percutaneous dilatational tracheostomy (PDT) prior to our examination. The endoscopic examination revealed that 89.5% (34/38) of the patients exhibited tracheal stenosis, less than 25% without clinical symptoms. Despite endoscopic guidance during PDT, the location of the puncture site was found to vary greatly. Cricoidal lesions were identified in 15 patients. In only 12 patients (31.6%), the PDT had been placed at the optimal location between the first and the second tracheal ring. In these patients, we found the lowest rate of tracheal stenosis in tracheotomies without fractured tracheal rings. CONCLUSION Since clinically relevant tracheal stenosis has been found to depend mainly on the puncture site of the PDT and tracheal fractures during PDT, we want to emphasize the importance of adequate endoscopic guidance during and the careful performance of the PDT. Further follow-up studies are necessary to improve and ensure the quality of PDT techniques.
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Dollner R, Verch M, Schweiger P, Deluigi C, Graf B, Wallner F. Laryngotracheoscopic findings in long-term follow-up after Griggs tracheostomy. Chest 2002; 122:206-12. [PMID: 12114360 DOI: 10.1378/chest.122.1.206] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
Abstract
OBJECTIVE Analysis of laryngotracheoscopic findings of the upper airway tract following percutaneous tracheostomy using the technique according to Griggs. DESIGN Retrospective cohort study PATIENTS Nineteen of 32 long-term surviving patients (mean follow-up duration, 17 months; range, 11 to 23 months) underwent a modified Griggs tracheostomy during their stay in the ICU following cardiothoracic surgery. INTERVENTIONS Nineteen patients gave their informed consent for laryngotracheoscopy to localize and assess the percutaneous dilatational tracheostomy (PDT) puncture site, to evaluate the laryngotracheal morphology, and to quantify tracheal stenosis if present. In addition, specific symptoms of the upper airway tract were evaluated. RESULTS At the time of examination, no clinically relevant cases of stenoses were found, although one patient had undergone surgical revision of the PDT for extensive granulation prior to our examination. The endoscopic examination revealed that 12 of 19 patients (63%) had tracheal stenoses > 10%, and 2 patients had tracheal stenoses > 25%. In 7 of 19 patients (32%), the cricoid cartilage was affected by the PDT site. Despite endoscopic guidance during PDT, the location of the puncture site was found to vary greatly. CONCLUSION In contrast to recent reports on the long-term outcome after Griggs PDT, we found tracheal stenoses > 10% in 63% of our patients. The grade of stenosis depended mainly on the puncture site of the PDT. Based on these results, we would emphasize the importance of adequate endoscopic guidance during PDT. Further studies are required in order to clarify the risk of long-term complications arising after PDT using the technique of Griggs.
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Eucker J, Sezer O, Graf B, Possinger K. Mucormycoses. Mycoses 2002; 44:253-60. [PMID: 11714058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Over recent years the clinical importance of mucormycosis has significantly increased. Most frequently mucormycosis occurs in neutropenic patients with haematological diseases. It is caused by fungi of the order Mucorales. The clinical patterns of the disease produced by different genera or species of Mucorales are virtually identical. Rhizopus, Absidia, Rhizomucor and Mucor are the organisms most commonly isolated from patients who suffer from mucormycosis. Diagnosis of mucormycosis is difficult as it is based on culture methods or microscopy of clinical specimens. The diagnosis is often only made after a delay or even post-mortem. Therapy includes surgical intervention if possible and is based on systemic amphotericin B (conventional or liposomal).
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Bergemann C, Löken C, Becker C, Graf B, Hamidizadeh M, Fischer Y. Inhibition of glucose transport by cyclic GMP in cardiomyocytes. Life Sci 2001; 69:1391-406. [PMID: 11531163 DOI: 10.1016/s0024-3205(01)01222-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Recent evidence points to a potential role of cyclic GMP (cGMP) in the control of cardiac glucose utilization. The present work examines whether the glucose transport system of cardiac myocyte is a site of this cGMP-dependent regulation. Treatment of isolated rat cardiomyocytes (for 10 min) with the membrane-permeant cGMP analogue 8-(4-chlorophenylthio)-cGMP (8-p-CPT-cGMP, 200 microM) caused a decrease in glucose transport in non-stimulated (basal) myocytes, as well as in cells stimulated with insulin or with the mitochondrial inhibitor oligomycin B by up to 40%. An inhibitory effect was also observed with another cGMP analogue (8-bromo-cGMP), and in cells stimulated by hydrogen peroxide or anoxia. In contrast, 8-p-CPT-cAMP (200 microM), or the beta-adrenergic agonist isoprenaline (which increases cAMP levels) did not depress glucose transport, and even potentiated the effect of insulin. Blockade of endogenous cGMP formation with the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ, 10 microM) significantly increased basal and insulin-dependent glucose transport (by 25%), whereas addition of the guanylate cyclase activator 3-(5'-hydroxymethyl-2'furyl)-1-benzylindazol (YC-1, 30 microM) produced a depression of glucose transport (by 20%). Confocal laser scanning microscopic studies revealed that cGMP partially prevents the insulin-induced redistribution of the glucose transporter GLUT4 from intracellular stores to the cell surface. These observations suggest that the glucose transport system of cardiomyocytes represents a metabolic target of inhibition by cGMP, and that this regulation occurs at the level of the trafficking of glucose transporters.
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Graf B, Mendenhall R, Suero M, Wiggins R. Study status consistency and duplicate-read protection in a distributed architecture. J Digit Imaging 2001; 14:60-2. [PMID: 11442124 PMCID: PMC3452666 DOI: 10.1007/bf03190298] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
UNLABELLED This presentation will discuss the benefits and pitfalls of implementing a study status and duplicate-read protection mechanism within a distributed picture archiving and communication system (PACS) architecture. There are many advantages to a distributed PACS network in which image studies are proactively pushed to reading stations before they are required by a radiologist. The absence of a central server, which serves on demand, makes managing study status and protecting against duplicate reads challenging. The system to manage study status and read access must be efficient, robust, and easy to administer. A system is presented that accomplishes these goals while maintaining the advantages of a distributed architecture. METHODS The basic workflow of the system is that image studies acquired at a modality device are automatically sent to an archive server. Using a set of advanced routing rules, the archive automatically routes studies to diagnostic workstations where studies are candidates for diagnostic read. The workstations display a list of all local studies available for reading. A monitor application running on the workstations coordinates access to studies for diagnostic read. Once the status of a study has been changed, the workstations on the networks and the archive are notified, which causes the study to be automatically removed from any list on a workstation where it might be a read candidate. RESULTS Implementation of this system provides a balanced workflow throughout the system while minimizing the need for costly high-speed network hardware. Additionally studies are read as soon as they are available by the next available radiologist. This workflow is enabled without the need for specific interaction by any of the radiologists on the network. By having the images available at the workstation in an organized worklist, this methodology increases the efficiency of the radiologist. CONCLUSION The implementation of this system enables a radiology department, or even a specialty group within a department, to gain the benefit of a distributed system as well as the benefits provided by a central-server architecture. This can be done very cost effectively with minimal configuration overhead and hardware requirements.
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Sievers HH, Schmidtke C, Graf B. Hemodynamics of semilunar valves at rest and exercise at an average of more than two years after the Ross procedure. THE JOURNAL OF HEART VALVE DISEASE 2001; 10:166-169; discussion 169-70. [PMID: 11297202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/19/2023]
Abstract
BACKGROUND AND AIM OF THE STUDY Rest, and especially exercise, hemodynamics are valuable determinants to assess outcome of the Ross procedure. In this study, the degree of insufficiency and pressure gradients at rest across the autograft and homograft, as well as the pressure gradients at exercise, were measured. METHODS Among 115 patients operated on between February 1990 and February 1999, 67 were evaluated echocardiographically at rest and moderate exercise. The mean patient age at subcoronary implantation was 52 +/- 13 years. The mean interval between surgery and investigation was 27.3 +/- 17.4 months. The exercise level was 100 W (n = 47), 75 W (n = 14) or 50 W (n = 6). RESULTS Fifty-two patients had no or trace aortic insufficiency, 23 were grade I/IV, and two were grade II/IV. Pulmonary insufficiency was graded as none (n = 45), mild (n = 21), and moderate (n = 1). Heart rate increased from 70 +/- 12 beats/min at rest to 108 +/- 19 beats/min at exercise. The maximal pressure gradient across the autograft increased from 6.1 +/- 2.3 mmHg at rest to 8.7 +/- 4.1 mmHg at exercise. The maximal pressure gradient across the homograft increased from 11.8 +/- 5.3 mmHg at rest to 17.7 +/- 8.2 mmHg at exercise. A pressure gradient across the homograft >25 mmHg was measured in 13 patients. CONCLUSION In most patients, hemodynamics at rest and moderate exercise at an average of more than two years after the Ross procedure were excellent. Some homografts developed pressure gradients at exercise; this finding will form the target of future surgical and scientific investigations.
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Graf B, Bähler M, Hilpelä P, Böwe C, Adam T. Functional role for the class IX myosin myr5 in epithelial cell infection by Shigella flexneri. Cell Microbiol 2000; 2:601-16. [PMID: 11207612 DOI: 10.1046/j.1462-5822.2000.00084.x] [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: 11/20/2022]
Abstract
Efficient control of Shigella-induced, rho-dependent cytoskeletal rearrangements seems to be required to shape the delicate cellular structures associated with bacterial invasion of epithelial cells. We therefore studied a class IX myosin and rho antagonist, the GTPase-activating protein (GAP) myr5, for a potential role in the bacterial entry process. We show that myr5 is recruited into bacterial entry spots. The recruitment pattern resembled that of rhoC or ezrin, but not rhoA, rac or CDC42, while in vitro GAP activity of myr5 was similar for rhoA, B or C. Analysis of myr5 mutants suggested that GTPase- or ATP-binding activites are not required for Shigella-induced recruitment of this atypical myosin to the bacterial entry site. Functional studies revealed a potential dual role of the myosin functions and the GAP module of myr5 for bacterial internalization.
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Juckel G, Vogel M, Präßl A, Graf B, Mavrogiorgou P, Hegerl U. S04.04 Facial expressions and personality. Eur Psychiatry 2000. [DOI: 10.1016/s0924-9338(00)93926-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Bartels C, Bechtel JF, Tölg R, Graf B, Walenda C, Leyh R, Nötzold A, Richardt G, Sievers HH. [Intermediate term clinical results after endoaneurysmorrhaphy in left ventricular aneurysm]. ZEITSCHRIFT FUR KARDIOLOGIE 2000; 89:754-60. [PMID: 11077684 DOI: 10.1007/s003920070178] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Endoaneurysmorrhaphy (EAR) in postinfarct ventricular aneurysms leads to excellent short-term results. However, the temporal response of EAR is widely unknown. Thus, the indication for surgical treatment of patients with ventricular aneurysms is not well defined. EAR was performed in 157 patients (6/1993-6/1999) with symptomatic ventricular aneurysms (median NYHA III). Factors influencing cardiac mortality and morbidity during follow-up were determined by univariate and multivariate analysis. Perioperative mortality was low: 5%. Mortality during follow-up was 3.3% per year, resulting in a 5-year survival rate of 78%. NYHA classification ameliorated significantly from the preoperative status compared to the follow-up period (median NYHA II; p < 0.001). Multivariate analysis identified preexisting arterial occlusive disease and advanced age (> 70 years) as significant factors influencing medium-term mortality. Implantation of the left internal mammary artery was associated with a better survival rate. Endoaneurysmorrhaphy can be performed with low perioperative mortality, will result in a significant amelioration of the cardiac clinical status and offers low medium-term mortality. Our data indicate that EAR seems to be the procedure of choice for patients with symptomatic ventricular aneurysms.
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Eucker J, Sezer O, Lehmann R, Weber JR, Graf B, Denkert C, Brück W, Schweigert M, Possinger K. Disseminated mucormycosis caused by Absidia corymbifera leading to cerebral vasculitis. Infection 2000; 28:246-50. [PMID: 10961535 DOI: 10.1007/s150100070047] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
An 18-year-old woman was admitted to hospital because of subcutaneous hematoma and fever of unknown origin. Acute myeloid leukemia was diagnosed and empirical antimicrobial treatment and induction chemotherapy were started. After initial defervescence, fever relapsed 2 days after the onset of neutropenia. The CT scan of the lung was consistent with an invasive fungal infection. Treatment with amphotericin B was started and antimicrobial treatment was continued with liposomal amphotericin B because of an increase in creatinine later. The fever persisted and the patient suddenly developed progressive neurological symptoms. CT scan of the head suggested cerebral infarction and angiography of the extra- and intracranial arteries showed signs of vasculitis. Six days after the onset of neurological symptoms cerebral death was diagnosed. Autopsy revealed non-septate, irregularly branched hyphae in various histologic sections including brain. Absidia corymbifera could be isolated from lung tissue confirming the diagnosis of disseminated mucormycosis. In this case, angiographic findings suggested severe cerebral vasculitis which was in fact caused by thromboembolic dissemination of fungal hyphae. This case underlines the fact that cerebral symptoms in febrile neutropenic patients are highly indicative for fungal infections of the brain.
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Graf B, Adam T, Zill E, Göbel UB. Evaluation of the VITEK 2 system for rapid identification of yeasts and yeast-like organisms. J Clin Microbiol 2000; 38:1782-5. [PMID: 10790099 PMCID: PMC86587 DOI: 10.1128/jcm.38.5.1782-1785.2000] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The new VITEK 2 system is a fully automated system dedicated to the identification and susceptibility testing of microorganisms. In conjunction with the VITEK ID-YST card the VITEK 2 system allows the identification of clinically important yeasts and yeast-like organisms in 15 h due to a sensitive fluorescence-based technology. The ID-YST card consists of 47 biochemical reactions. The database comprises 51 taxa, including newly described species. In this study we evaluated the reliability of the VITEK ID-YST card for the identification of yeasts and yeast-like organisms encountered in a clinical microbiology laboratory. A total of 241 strains representing 21 species were studied. The strains were isolated from clinical samples within a period of 60 days prior to the identification. The tests were performed using 24-h to 55-h subcultures on Sabouraud-gentamicin-chloramphenicol agar. Each strain was tested in parallel using the ID 32C strip as a comparison method combined with microscopic morphology and an agglutination test for C. krusei. Overall, 222 strains (92.1%) were unequivocally identified including 11 isolates (4.6%) identified with low discrimination resolved by simple additional tests. Ten strains (4. 1%) for which results were given with low discrimination could not be unequivocally identified with supplemental tests, 4 strains (1. 7%) were misidentified and 5 strains (2.1%) could not be identified. In conclusion, we found that the VITEK 2 system is a rapid and accurate method for the identification of medically important yeasts and yeast-like organisms.
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Graf B, Simon U, Eickmeyer F, Fiedler V. 1K versus 2K monitor: a clinical alternative free-response receiver operating characteristic study of observer performance using pulmonary nodules. AJR Am J Roentgenol 2000; 174:1067-74. [PMID: 10749252 DOI: 10.2214/ajr.174.4.1741067] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The aim of this study was to investigate whether and how observer performance in detecting pulmonary nodules is influenced by the use of 1K and 2K monitors with and without voluntary postprocessing. MATERIALS AND METHODS The study was conducted with clinical digital chest radiographs of 48 patients. CT images of the same patient group served as the gold standard. Data on four different monitor conditions (1K overview, 2K overview, 1K with postprocessing, and 2K with postprocessing) were collected using a 6-point confidence-rating scale and interpreted with an alternative free-response receiver operating characteristic. RESULTS When magnification and window settings were applied on the 1K monitor at the expense of an increased interpretation time, observer performance with the 1K monitor was not significantly different from that with the 2K monitor. A significant difference only occurred between the 1K monitor postprocessing condition and the 1K monitor overview condition. CONCLUSION Considering diagnostic accuracy, the 1K monitor is sufficient for the detection of pulmonary nodules, provided that postprocessing options--especially magnification--are applied. Further comparative monitor studies on the detectability of other abnormalities (e.g., fine interstitial structures) need to be performed.
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Knuchel MC, Graf B, Schlaepfer E, Kuster H, Fischer M, Weber R, Cone RW. PCR-derived ssDNA probes for fluorescent in situ hybridization to HIV-1 RNA. J Histochem Cytochem 2000; 48:285-94. [PMID: 10639495 DOI: 10.1177/002215540004800214] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
We developed a simple and rapid technique to synthesize single-stranded DNA (ssDNA) probes for fluorescent in situ hybridization (ISH) to human immunodeficiency virus 1 (HIV-1) RNA. The target HIV-1 regions were amplified by the polymerase chain reaction (PCR) and were simultaneously labeled with dUTP. This product served as template for an optimized asymmetric PCR (one-primer PCR) that incorporated digoxigenin (dig)-labeled dUTP. The input DNA was subsequently digested by uracil DNA glycosylase, leaving intact, single-stranded, digoxigenin-labeled DNA probe. A cocktail of ssDNA probes representing 55% of the HIV-1 genome was hybridized to HIV-1-infected 8E5 T-cells and uninfected H9 T-cells. For comparison, parallel hybridizations were done with a plasmid-derived RNA probe mix covering 85% of the genome and a PCR-derived RNA probe mix covering 63% of the genome. All three probe types produced bright signals, but the best signal-to-noise ratios and the highest sensitivities were obtained with the ssDNA probe. In addition, the ssDNA probe syntheses generated large amounts of probe (0.5 to 1 microg ssDNA probe per synthesis) and were easier to perform than the RNA probe syntheses. These results suggest that ssDNA probes may be preferable to RNA probes for fluorescent ISH. (J Histochem Cytochem 48:285-293, 2000)
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Trittenwein G, Pansi H, Graf B, Golej J, Burda G, Hermon M, Marx M, Wollenek G, Trittenwein H, Pollak A. Proposed entry criteria for postoperative cardiac extracorporeal membrane oxygenation after pediatric open heart surgery. Artif Organs 1999; 23:1010-4. [PMID: 10564307 DOI: 10.1046/j.1525-1594.1999.06457.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
While extracorporeal membrane oxygenation (ECMO) is being used increasingly after pediatric cardiac surgery, criteria are lacking for initiating ECMO after bypass weaning. To develop clinically useful ECMO entry criteria based on parameters readily available, children were examined at postoperative pediatric intensive care unit (PICU) admission. Using hospital mortality as the primary outcome, univariate and multiple logistic regressions were performed to estimate the predictive value of clinical (age, weight, and diagnosis) and laboratory (arterial blood pressure, pH, lactate, creatine kinase, and arterial and central venous oxygen saturation [ScvO2]) variables. Data from 218 children over a 2 year period were analyzed retrospectively. Univariate regression demonstrated that age, weight, diagnosis, blood pressure, venous and arterial saturation, and lactate were significantly associated with postoperative mortality (p < 0.05). In multiple regression, ScvO2 and lactate level were found to be independent predictors and were used in a predictive model (ScvO2 odds ratio: 2.03-828.6, p = 0.016) (lactate odds ratio: 1.58 -4.20, p = 0.0002) (R2 = 0.70). Applying an 80% risk of mortality to establish entry criteria as in neonatal ECMO, PICU admission values of lactate > 70 mg/dl if ScvO2 < 60% or lactate >163 mg/dl if ScvO2 > 60% are proposed to serve as postoperative ECMO entry criteria if bypass weaning has been possible but is followed by low cardiac output.
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Farquharson A, Wu HC, Grant I, Graf B, Choung JJ, Eremin O, Heys S, Wahle K. Possible mechanisms for the putative antiatherogenic and antitumorigenic effects of conjugated polyenoic fatty acids. Lipids 1999; 34 Suppl:S343. [PMID: 10419197 DOI: 10.1007/bf02562337] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
Fluorescence microscopy is an important method in mycology. It is a common procedure used in immunology or histology and more recently in modern techniques of molecular biology like in-situ hybridization. Since several molds and yeasts show autofluorescence, an interference of this phenomenon with the detection method cannot be excluded. Therefore, we studied autofluorescence in fungi in more detail, in particular with respect to the dependence of this phenomenon from growth conditions, fixing method or mounting medium used. Here we show that moulds cultivated in a liquid medium are strongly autofluorescent which could be considerably reduced by repetitive washing. In moulds, we did not find important differences in autofluorescence levels with the three fixing methods under study. However, this finding cannot be generalized. Thus, in the yeast Candida albicans we found the autofluorescence pattern being largely dependent from the fixing method and the excitation wave length, respectively. In particular, with green excitation we could show that aceton fixation resulted in strong fluorescence of individual cells within a vast population of cells showing little or no autofluorescence. In addition, we could demonstrate that mounting media are able to strongly modify autofluorescence in fungi. Using digital image acquisition with a cooled CCD camera we were able to quantify the influence of different mounting media on fluorescence intensities of Aspergillus fumigatus.
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Graf AH, Graf B, Brandis MG, Kogelnik HD, Staudach A, Traun H. Oral Anticoagulation in patients with gynecological cancer and radiotherapy: a retrospective analysis of 132 patients. Anticancer Res 1998; 18:2047-51. [PMID: 9677465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Venous thromboembolism is reported to be a leading cause of death and morbidity after surgery and during radiotherapy for gynecologic malignancies. This study was performed to evaluate the incidence of thromboembolism as well as the benefit and risk of its prophylaxis with coumarin in this patient selection. Between 1988 and 1992, 132 patients with gynecologic malignancies underwent postoperative or primary radiotherapy (53 patients without prior surgery). Heparin (5000 IU t.i.d., s.c.) was administered perioperatively, and coumarin (International normalized ratio = INR target 2.0-3.5) was given to all patients during radiotherapy. Daily visits for inspection of the legs and for possible symptoms and signs of thromboembolism were performed. In case of diagnostic doubts, impedance plethysmography and phlebography for diagnosis of venous thrombosis, and lung scanning for diagnosis of pulmonary embolism were performed. Among the 132 patients, 9 (6.8%) developed deep venous thrombosis of the renal vein and of the inferior caval vein occurred in one additional patient. Pulmonary embolism was detected in 5 patients (3.8%). All thromboembolic events were without lethal outcome. Bleeding episodes were observed in 7 patients (5.3%); in two of them a major bleeding led to cessation of coumarin administration. The prophylaxis of thromboembolism in gynecologic oncology with coumarin seems to be effective, safe and inexpensive.
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