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Greeven APA, Hammer S, Deruiter MC, Schipper IB. Accuracy of fluoroscopy in the treatment of intra-articular thumb metacarpal fractures. J Hand Surg Eur Vol 2013. [PMID: 23186860 DOI: 10.1177/1753193412468565] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The purpose of this study was to determine the accuracy of fluoroscopic imaging during closed reduction and percutaneous fixation of intra-articular thumb metacarpal fractures. Closed reduction and percutaneous fixation was assessed in eight simulated intra-articular thumb metacarpal fractures, using fluoroscopy and digital radiographs. Displacement and fracture step-off were measured during fluoroscopy, on plain radiographs, and by direct visualization after careful dissection. Displacement on fluoroscopy was 0.8 (SD 1.0) mm and 1.2 (SD 1.4) with radiographic imaging. Direct visualization showed displacement of 0.9 (SD 1.2) mm. Intra-articular step-off on fluoroscopy was 0.8 (SD 1.0) mm and 0.8 (SD 0.8) with radiographic imaging. Direct visualization showed an intra-articular step-off of 0.8 (SD 1.2) mm. Statistical analysis showed excellent compatibility between fluoroscopy and direct visualization. Fluoroscopic visualization during surgery provides an adequate assessment of articular step-off and displacement in comparison with radiographs and direct visualization.
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Uller W, Müller-Wille R, Loss M, Hammer S, Schleder S, Goessmann H, Wiggermann P, Stroszczynski C, Wohlgemuth W. Percutaneous Management of Postoperative Bile Leaks with an Ethylene Vinyl Alcohol Copolymer (Onyx). ROFO-FORTSCHR RONTG 2013; 185:1182-7. [DOI: 10.1055/s-0033-1350153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Jordan MR, Bennett DE, Wainberg MA, Havlir D, Hammer S, Yang C, Morris L, Peeters M, Wensing AM, Parkin N, Nachega JB, Phillips A, De Luca A, Geng E, Calmy A, Raizes E, Sandstrom P, Archibald CP, Perriëns J, McClure CM, Hong SY, McMahon JH, Dedes N, Sutherland D, Bertagnolio S. Update on World Health Organization HIV drug resistance prevention and assessment strategy: 2004-2011. Clin Infect Dis 2012; 54 Suppl 4:S245-9. [PMID: 22544182 DOI: 10.1093/cid/cis206] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
The HIV drug resistance (HIVDR) prevention and assessment strategy, developed by the World Health Organization (WHO) in partnership with HIVResNet, includes monitoring of HIVDR early warning indicators, surveys to assess acquired and transmitted HIVDR, and development of an accredited HIVDR genotyping laboratory network to support survey implementation in resource-limited settings. As of June 2011, 52 countries had implemented at least 1 element of the strategy, and 27 laboratories had been accredited. As access to antiretrovirals expands under the WHO/Joint United Nations Programme on HIV/AIDS Treatment 2.0 initiative, it is essential to strengthen HIVDR surveillance efforts in the face of increasing concern about HIVDR emergence and transmission.
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Williams WB, Jones K, Krambrink A, Grove D, Liu P, Yates NL, Moody MA, Ferrari G, Pollara J, Moodie Z, Morgan CA, Liao H, Montefiori DC, Ochsenbauer C, Kappes J, Hammer S, Mascola J, Koup R, Corey L, Nabel G, Gilbert P, Churchyard G, Keefer M, Graham BS, Haynes BF, Tomaras GD. Multiple antibody specificities (gp41, V1V2, and V3) elicited in the phase II multiclade (A, B, C) HIV-1 DNA prime, rAd5 boost vaccine trial. Retrovirology 2012. [PMCID: PMC3441791 DOI: 10.1186/1742-4690-9-s2-o55] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Hoffstetter P, Hammer S, Röhrl S, Dendl LM, Dornia C, Rennert J, Müller-Wille R, Wiggermann P, Stroszczynski C, Schreyer AG. [As time goes by--is it worth intensifying patient care during the waiting period for radiological examinations?]. ROFO-FORTSCHR RONTG 2012; 184:1043-8. [PMID: 22851298 DOI: 10.1055/s-0032-1313049] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
PURPOSE Service characteristics in hospital care in general have a high influence on patients' contentment. One of the key features of good service is waiting time. The aim of this study was to analyze the influence of ambience and individual care while waiting for a radiological examination on patient satisfaction. MATERIALS AND METHODS The study was conducted prospectively and included and total of 100 patients at a tertiary care center. All patients waiting for contrast-enhanced computed tomography (CT) and were randomly divided into two groups. 50 patients waited under regular circumstances, i.e. the normal waiting ara of our radiological department, whilst the remaining 50 patients spent their waiting time in a separate small waiting area with intensified care and service. Both subjective and objective waiting time and the patients' contentment were raised with a standardized questionnaire. Quality criteria mentioned by the patients were then ranked according to their importance. RESULTS Of all included patients 76 % were ambulant with an average age of 60 years (range 22 - 83 years) and 69 % female. These characteristics were identical in both groups. With a mean waiting time of 90 minutes (Group intensified care 100 minutes, group regular care 81 minutes) most patients evaluated the overall service during waiting time as "good" to "ideal", only 2 % as of "low quality". No significant differences between the two study arms concerning the patient satisfaction could be detected. Patients with intensified care estimated their delay time significantly shorter by an average of 24 minutes (p < 0.02). For 40 % a detailed consent discussion was the main quality criterion, while a short waiting time only for 24 %. CONCLUSION An optimized, i.e. intensified care during the waiting time for a radiological examination results in a significant reduction of the subjective waiting time, but does not lead to a significantly higher patient contentment. The subjective judgement of examination quality seems to influence the acceptance of prolonged latency to a high degree.
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Uller W, Huber T, Hammer S, Wohlgemuth W, Stroszczynski C, Schreyer AG. Stent-PTA der Vena Cava Inferior nach Lebertransplantation und -resektion. ROFO-FORTSCHR RONTG 2012. [DOI: 10.1055/s-0032-1311145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Spitzer C, Hammer S, Löwe B, Grabe H, Barnow S, Rose M, Wingenfeld K, Freyberger H, Franke G. Die Kurzform des Brief Symptom Inventory (BSI -18): erste Befunde zu den psychometrischen Kennwerten der deutschen Version. FORTSCHRITTE DER NEUROLOGIE-PSYCHIATRIE 2011; 79:517-23. [DOI: 10.1055/s-0031-1281602] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Merk J, Hammer S, Rolff J, Becker M, Politz O, Sommer A, Klemm W, Hoffmann J, Fichtner I, Leschber G. Analyse von Stoffwechselwegen im primären Xenograftmodell unter Chemotherapie - Option zur Erforschung neuer antitumorigener Wirksubstanzen beim Lungenkarzinom? Pneumologie 2011. [DOI: 10.1055/s-0031-1272221] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Dubey JP, Pas A, Rajendran C, Kwok OCH, Ferreira LR, Martins J, Hebel C, Hammer S, Su C. Toxoplasmosis in Sand cats (Felis margarita) and other animals in the Breeding Centre for Endangered Arabian Wildlife in the United Arab Emirates and Al Wabra Wildlife Preservation, the State of Qatar. Vet Parasitol 2010; 172:195-203. [PMID: 20570441 PMCID: PMC7116901 DOI: 10.1016/j.vetpar.2010.05.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2010] [Revised: 05/10/2010] [Accepted: 05/11/2010] [Indexed: 11/24/2022]
Abstract
The Sand cat (Felis margarita) is a small-sized felid found in sand and stone deserts ranging from the north of Africa to Asia, with the Arabian Peninsula as its centre of distribution. The Sand cat captive breeding program at the Breeding Centre for Endangered Arabian Wildlife (BCEAW), Sharjah, UAE, has experienced high newborn mortality rates, and congenital toxoplasmosis was recently recognized as one of the causes of this mortality. In the present study, one 18-month-old Sand cat (FM019) died of acute toxoplasmosis-associated hepatitis and pneumonitis acquired after birth; Toxoplasma gondii was demonstrated in histological sections which reacted with T. gondii polyclonal antibodies by immunohistochemistry (IHC). T. gondii DNA was found by PCR of extracted DNA from liver and lung tissues of this cat. Antibodies to T. gondii were found in serum examined in 1:1600 dilution in the modified agglutination test (MAT); its 2-year-old cage mate seroconverted (MAT titer 1:3200) at the same time. Another Sand cat (FM017) was euthanized because of ill health when 3 years old; its MAT titer was >1:3200, and T. gondii tissue cysts were found in brain, heart, ocular muscles and skeletal muscle, confirmed by IHC. Viable T. gondii was isolated by bioassays in mice inoculated with tissues of another chronically infected Sand cat (FM002); T. gondii was not found in histological sections of this cat. T. gondii antibodies were found in several species of animals tested, notably in 49 of 57 wild felids at BCEAW. A 7-year-old Sand cat (3657) from Al Wabra Wildlife Preservation (AWWP), Doha, State of Qatar died of acute visceral toxoplasmosis with demonstrable T. gondii tachyzoites by IHC, and T. gondii DNA by PCR, and a MAT titer of >3200. T. gondii antibodies were found in 21 of 27 of wild felids at AWWP. PCR-RFLP genotyping at 10 genetic loci revealed that these T. gondii isolates from Sand cat (FM002 and FM019) at BCEAW have an atypical genotype, which was previously reported in T. gondii isolates of dogs from Sri Lanka. The genotype from the cat from AWWP (3657) is a genetic Type II strain with a Type I allele at locus Apico. This is the first report of genetic characterization of T. gondii isolates from Middle East.
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Luján L, Crespo T, Deb A, Arif A, Borjal R, Salazar E, Álvarez N, Pérez M, Dorrestein G, Hammer S. Aa Amyloidosis in Captive Beira Antelopes (Dorcatragus Megalotis) Linked to Mycoplasmal Pleuropneumonia. J Comp Pathol 2009. [DOI: 10.1016/j.jcpa.2009.08.074] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hammer S, Meisner F, Dirschedl P, Fraunberger P, Meiser B, Reichart B, Hammer C. Procalcitonin for differential diagnosis of graft rejection and infection in patients with heart and/or lung grafts. Intensive Care Med 2009. [PMID: 18470717 PMCID: PMC7095472 DOI: 10.1007/s001340051141] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVES Investigation of the reliability of Procalcitonin (PCT) for differential diagnosis of acute rejections and non-viral infections in heart and lung transplanted patients. DESIGN Retrospective study. SETTING Transplant intensive care unit (ICU) at a university hospital. PATIENTS 57 heart, 18 lung and 3 heart-lung transplant patients. MEASUREMENTS PCT was measured in plasma samples of heart and lung transplanted patients using a commercial immuno-luminescence assay and was compared with values of C-reactive protein (CRP) and leukocytes (WBC). RESULTS PCT was elevated in patients suffering from bacterial and fungal infections. The magnitude of values was clearly associated with the severity of the infection. Rejections and viral infections did not interfere with the PCT release. CONCLUSION PCT is a reliable predictor with discriminating power for non-viral systemic infections in patients after heart and/or lung transplantation. PCT allows an early differential diagnosis between rejection (AR) and bacterial/fungal infection (IF) and thus a rapid and focused therapeutic intervention. It avoids unnecessary antibiotic treatment which could be toxic for the graft itself in patients with rejection only. PCT provides vital information early to clinicians and allows them to improve the management of bacterial/fungal infections in immunocompromized transplant patients. PCT thus facilitates and improves the outcome of survival rate and the quality of life in the postoperative period of patients with heart and/or lung grafts.
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Hammer S, Meisner F, Dirschedl P, Fraunberger P, Meiser B, Reichart B, Hammer C. Procalcitonin for differential diagnosis of graft rejection and infection in patients with heart and/or lung grafts. Intensive Care Med 2009; 26 Suppl 2:S182-6. [PMID: 18470717 DOI: 10.1007/bf02900735] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Investigation of the reliability of Procalcitonin (PCT) for differential diagnosis of acute rejections and non-viral infections in heart and lung transplanted patients. DESIGN Retrospective study. SETTING Transplant intensive care unit (ICU) at a university hospital. PATIENTS 57 heart, 18 lung and 3 heart-lung transplant patients. MEASUREMENTS PCT was measured in plasma samples of heart and lung transplanted patients using a commercial immuno-luminescence assay and was compared with values of C-reactive protein (CRP) and leukocytes (WBC). RESULTS PCT was elevated in patients suffering from bacterial and fungal infections. The magnitude of values was clearly associated with the severity of the infection. Rejections and viral infections did not interfere with the PCT release. CONCLUSION PCT is a reliable predictor with discriminating power for non-viral systemic infections in patients after heart and/or lung transplantation. PCT allows an early differential diagnosis between rejection (AR) and bacterial/fungal infection (IF) and thus a rapid and focused therapeutic intervention. It avoids unnecessary antibiotic treatment which could be toxic for the graft itself in patients with rejection only. PCT provides vital information early to clinicians and allows them to improve the management of bacterial/fungal infections in immunocompromized transplant patients. PCT thus facilitates and improves the outcome of survival rate and the quality of life in the postoperative period of patients with heart and/or lung grafts.
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Abstract
BACKGROUND In the Netherlands, bicycle helmet wearing rates are very low and perceived social barriers to helmet use are important. We aimed to determine why Dutch paediatricians do or do not wear helmets while bicycling and whether their personal behaviour is influencing their position about the promotion of helmet use. METHODS Attendants to the annual meeting of the Dutch Paediatric Society (7-9 November 2006) were surveyed about bicycle riding frequency, helmet use, reasons for not wearing a helmet, helmet use among their own children and personal position about the promotion and legislation of bicycle helmet use. RESULTS Of the 1110 paediatricians who are active in the Netherlands, 258 answered the survey. Ninety-six per cent of the respondents ride a bicycle (68% more than once a week). Bicycle was used as a mean of transport (32%), as a recreation/sport (11%) or with both purposes (57%). When cycling for transportation, 94% never wear a helmet and 2% always wear it. When cycling for recreation, 70% never wear a helmet and 18% always wear it. The most common reasons given for not wearing a helmet were: 'I never thought about that' (43%), 'Poor appearance' (31%), 'Nobody uses it in the Netherlands' (27%) and 'Uncomfortable' (25%). A majority (91%) of the respondents agreed that bicycle helmets are effective in reducing the rate of head injury to bicyclists and that they should be advised to children (82%) and adolescents (54%). CONCLUSIONS Our results indicate that among Dutch paediatricians, cycling rate is high and helmet wearing rate is very low and that they experience numerous personal barriers to bicycle helmet use. This might explain why bicycle helmet promotion campaigns are scarcely supported by Dutch paediatricians.
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Hammer S, Tchoudakov R, Mechrez G, Cohen Y, Narkis M. Modification of porous PVC particles with PS and P(St-co
-MMA) using a surfactant-free aqueous dispersion polymerization technique. POLYM ADVAN TECHNOL 2008. [DOI: 10.1002/pat.1109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Hammer S, Wagenbach D, Preunkert S, Pio C, Schlosser C, Meinhardt F. Lead-210 observations within CARBOSOL: A diagnostic tool for assessing the spatiotemporal variability of related chemical aerosol species? ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd008065] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Hammer S, Arnold N, Hilpert F, Bräutigam K, Sommer A, Winsel S, Klar U, Hoffmann J. 5009 ORAL Significant antitumour activity of the novel epothilone ZK-EPO against in vitro and in vivo models of ovarian cancer. EJC Suppl 2007. [DOI: 10.1016/s1359-6349(07)71181-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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Legrand M, Preunkert S, Oliveira T, Pio CA, Hammer S, Gelencsér A, Kasper-Giebl A, Laj P. Origin of C2–C5dicarboxylic acids in the European atmosphere inferred from year-round aerosol study conducted at a west-east transect. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd008019] [Citation(s) in RCA: 114] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Dekkers OM, Hammer S, de Keizer RJW, Roelfsema F, Schutte PJ, Smit JWA, Romijn JA, Pereira AM. The natural course of non-functioning pituitary macroadenomas. Eur J Endocrinol 2007; 156:217-24. [PMID: 17287411 DOI: 10.1530/eje.1.02334] [Citation(s) in RCA: 118] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE The natural history of non-functioning pituitary macroadenomas (NFMA) has not been completely elucidated. Therefore, we evaluated pituitary function, visual fields, and tumor size during long-term follow-up of non-operated patients with NFMA. DESIGN Follow-up study. PATIENTS Twenty-eight patients (age 55 +/- 3 years) with NFMA, not operated after initial diagnosis, were included. RESULTS Initial presentation was pituitary insufficiency in 44%, visual field defects in 14%, apoplexy in 14%, and chronic headache in 7% of the patients. The duration of follow-up was 85 +/- 13 months. Radiological evidence of tumor growth was observed in 14 out of 28 patients (50%) after duration of follow-up of 118 +/- 24 months. Six patients (21%) were operated, because tumor growth was accompanied by visual field defects. Visual impairments improved in all the cases after transsphenoidal surgery. Spontaneous reduction in tumor volume was observed in eight patients (29%). No independent predictors for increase or decrease in tumor volume could be found by regression analysis. CONCLUSION Observation alone is a safe alternative for transsphenoidal surgery in selected NFMA patients, without the risk of irreversibly compromising visual function.
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Hammer S, Hammer C, Schulz J, Wernery U, Clauss M. Biochemische Serumparameter bei in Gefangenschaft gehaltenen Gazellen. Tierarztl Prax Ausg G Grosstiere Nutztiere 2006. [DOI: 10.1055/s-0037-1621069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Zusammenfassung:
Ziel der Untersuchung war, Serumparametervon klinisch unauffälligen Gazellen der Al Wabra Wildlife Preservation (AWWP), Qatar, mit Referenzbereichen von Haus- und anderen Wildwiederkäuern zu vergleichen, um einerseits Rückschlüsse auf den Ernährungszustand der Tiere zu ermöglichen und andererseits Referenzbereiche für die untersuchten Arten zu etablieren. Material und Methoden: Von 250 klinisch gesunden Tieren der Arten Sömmeringgazelle (Gazella soemmerringii), Spekegazelle (Gazella spekei), Dor-kasgazelle (Gazella dorcas), Saudigazelle (Gazella saudiya), Echtgazelle (Gazella gazella), Arabische Kropfgazelle (Gazella subgutturosa marica) und Chinkaragazelle (Gazella benetti) wurden biochemische Serumparameter und Mineralgehalte gemessen. Ergebnisse: Hinsichtlich des Ernährungszustandes war die Versorgung mit Spurenelementen (Selen, Kupfer, Zink, Eisen) in der AWWP gemäß den gemessenen Serumgehalten gewährleistet. Die Gehalte an Phosphor, Gesamtprotein und Albumin deuteten jedoch auf eine suboptimale Fütterung hin, die vermutlich mit der minderen Qualität des in der Region verfügbaren Raufutters zusammenhängt. Die Gehalte an Natrium, Kalium, Kalzium, Magnesium, Chlor, Triglyzeriden, Cholesterin, Kreatinin sowie die ALT- und γ-GT-Aktivität lagen-wie bei anderen Wildwiederkäuern auch - im Referenzbereich für Hauswiederkäuer, der daherfür die Beurteilung dieser Parameter bei Wiederkäuern generelle Gültigkeit besitzen dürfte. Die Gehalte an Glukose, Harnstoff-Stickstoff, Kreatinkinase sowie die AP-Aktivität hingegen scheinen bei Wildwiederkäuern generell erhöht zu sein. Während andere Wildwiederkäuer für AST mit Hauswiederkäuern vergleichbare Werte aufweisen, ist die Aktivität dieses Enzyms bei Gazellen in dieser und in anderen Studien durchweg erhöht. Schlussfolgerung und klinische Relevanz: Die in der Untersuchung festgestellten Besonderheiten müssen bei der Beurteilung von Blutanalysen beachtet werden.
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Sachweh J, Tiete A, Hammer S, Römer U, Reichart B, Däbritz S. Myocardial revascularization with the internal thoracic artery for myocardial ischemia during arterial switch operation. Thorac Cardiovasc Surg 2005. [DOI: 10.1055/s-2005-862149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Hammer S, Sauer B, Spika I, Schraut C, Kleuser B, Schäfer-Korting M. Glucocorticoids mediate differential anti-apoptotic effects in human fibroblasts and keratinocytes via sphingosine-1-phosphate formation. J Cell Biochem 2004. [PMID: 14991774 DOI: 10.1002/jcb.10766.pmid:14991774] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Glucocorticoids are potent anti-inflammatory and immunomodulatory drugs which also induce growth inhibition in a variety of cell types. For this reason long-term treatment of inflammatory skin diseases may result in irreversible skin atrophy. To elucidate whether the antiproliferative action of glucocorticoids in fibroblasts is accompanied by induction of apoptosis we investigated the influence of dexamethasone (DEX) on both parameters. Interestingly, we revealed that growth inhibitory concentrations of this glucocorticoid did not induce fibroblast apoptosis. Moreover, DEX protected these cells from apoptosis induced by tumor necrosis factor alpha (TNFalpha)/actinomycin, UV-irradiation, and cell permeable ceramides. These findings are in contrast to the lack of anti-apoptotic effects detected in keratinocytes. Although DEX inhibited TNFalpha mediated nuclear factor-kappa (NF-kappaB) activity in fibroblasts, this mechanism was not involved in its cytoprotection as it was verified by specific NF-kappaB inhibitors. Therefore, we looked for alternative intracellular mediators. Coincubation of fibroblasts with the sphingosine kinase inhibitor N,N-dimethylsphingosine, which blocks formation of the sphingolipid degradation product sphingosine-1-phosphate (S1P), abrogated the protective glucocorticoid effect almost completely. As preincubation with S1P reduced the number of apoptotic cells after stimulation with TNFalpha/actinomycin and moreover DEX increased the intracellular S1P content a role of this sphingolipid in the cytoprotection by DEX is suggested.
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Hammer S, Sauer B, Spika I, Schraut C, Kleuser B, Schäfer-Korting M. Glucocorticoids mediate differential anti-apoptotic effects in human fibroblasts and keratinocytes via sphingosine-1-phosphate formation. J Cell Biochem 2004; 91:840-51. [PMID: 14991774 DOI: 10.1002/jcb.10766] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Glucocorticoids are potent anti-inflammatory and immunomodulatory drugs which also induce growth inhibition in a variety of cell types. For this reason long-term treatment of inflammatory skin diseases may result in irreversible skin atrophy. To elucidate whether the antiproliferative action of glucocorticoids in fibroblasts is accompanied by induction of apoptosis we investigated the influence of dexamethasone (DEX) on both parameters. Interestingly, we revealed that growth inhibitory concentrations of this glucocorticoid did not induce fibroblast apoptosis. Moreover, DEX protected these cells from apoptosis induced by tumor necrosis factor alpha (TNFalpha)/actinomycin, UV-irradiation, and cell permeable ceramides. These findings are in contrast to the lack of anti-apoptotic effects detected in keratinocytes. Although DEX inhibited TNFalpha mediated nuclear factor-kappa (NF-kappaB) activity in fibroblasts, this mechanism was not involved in its cytoprotection as it was verified by specific NF-kappaB inhibitors. Therefore, we looked for alternative intracellular mediators. Coincubation of fibroblasts with the sphingosine kinase inhibitor N,N-dimethylsphingosine, which blocks formation of the sphingolipid degradation product sphingosine-1-phosphate (S1P), abrogated the protective glucocorticoid effect almost completely. As preincubation with S1P reduced the number of apoptotic cells after stimulation with TNFalpha/actinomycin and moreover DEX increased the intracellular S1P content a role of this sphingolipid in the cytoprotection by DEX is suggested.
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Münster U, Hammer S, Blume-Peytavi U, Schäfer-Korting M. Testosterone Metabolism in Human Skin Cells in vitro and Its Interaction with Estradiol and Dutasteride. Skin Pharmacol Physiol 2003; 16:356-66. [PMID: 14528059 DOI: 10.1159/000072930] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2002] [Indexed: 11/19/2022]
Abstract
Since the limited knowledge of cutaneous drug metabolism can impair the development of specifically acting topical dermatics and transdermal application systems, the cell-type-specific androgen metabolism in human skin and its inhibition by drugs were investigated. Cultured human foreskin and scalp skin keratinocytes and fibroblasts as well as occipital scalp dermal papilla cells (DPC) were incubated with testosterone 10(-6) and 10(-8)M alone and in the presence of 17alpha-estradiol, 17beta-estradiol or dutasteride for 24 h. Androgens extracted from culture supernatants were subjected to thin-layer chromatography and quantified by beta-counting. In keratinocytes and DPC, dihydrotestosterone (DHT) was only formed to a low extent while androstenedione was the main metabolite. In fibroblasts, DHT formation was pronounced following 10(-8)M testosterone. Dutasteride 10(-8)M completely suppressed 5alpha-dihydro metabolite formation. 17alpha-Estradiol and 17beta-estradiol at nontoxic concentrations decreased 17-ketometabolites. Human skin regulates testosterone action by cell-type-specific activation or deactivation. Effects of 17alpha-estradiol in androgenetic alopecia are not due to 5alpha-reductase inhibition. Dutasteride may be useful in acne and androgenetic alopecia.
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Abstract
BRIANHUNTLEYA, A NEW GENUS ENDEMIC TO THE WORCESTER-ROBERTSON KAROO, SOUTH AFRICA
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Schaschl H, Kaulfus D, Hammer S, Suchentrunk F. Spatial patterns of mitochondrial and nuclear gene pools in chamois (Rupicapra r. rupicapra) from the Eastern Alps. Heredity (Edinb) 2003; 91:125-35. [PMID: 12886279 DOI: 10.1038/sj.hdy.6800290] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
We have assessed the variability of maternally (mtDNA) and biparentally (allozymes) inherited genes of 443 chamois (Rupicapra r. rupicapra) from 19 regional samples in the Eastern Alps, to estimate the degree and patterns of spatial gene pool differentiation, and their possible causes. Based on a total mtDNA-RFLP approach with 16 hexanucleotide-recognizing restriction endonucleases, we found marked substructuring of the maternal gene pool into four phylogeographic groups. A hierarchical AMOVA revealed that 67.09% of the variance was partitioned among these four mtDNA-phylogroups, whereas only 8.04% were because of partitioning among regional samples within the populations, and 24.86% due to partitioning among individuals within regional samples. We interpreted this spatial pattern of mtDNA variability as a result of immigration of chamois from different Pleistocene refugia surrounding the Alps after the withdrawal of glaciers, rather than from topographic barriers to gene flow, such as Alpine valleys, extended glaciers or woodlands. However, this striking geographical structuring of the maternal genome was not paralleled by allelic variation at 33 allozyme loci, which were used as nuclear DNA markers. Wright's hierarchical F-statistics revealed that only < or =0.45% of the explained allozymic diversity was because of partitioning among the four mtDNA-phylogroups. We conclude that this discordance of spatial patterns of nuclear and mtDNA gene pools results from a phylogeographic background and sex-specific dispersal, with higher levels of philopatry in females.
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