Bibliothek

feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    ISSN: 1432-2277
    Schlagwort(e): Key words Transplantation ; Nitric oxide ; Endothelial function ; Gene expression ; Cytokines
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Endothelial dysfunction anticipates the development of transplant coronary artery disease (TxCAD) observed more than 1 year after transplantation (HTx). We investigated whether in patients early after HTx myocardial inducible and constitutive nitric oxide synthases (iNOS; cNOS) are expressed and cardiac nitric oxide production occurs. Moreover, a possible relationship to alterations in endothelium dependent and independent vasomotor function was assessed. Forty-two transplant recipients were studied 37 ± 5 days after HTx. Microvascular coronary flow velocity reserve (CFVR) was tested endothelium dependent (acetylcholine; 30 μg/min × 5 min/i.c.) and independent (adenosine; 160 μg/min × 5 min/i.c.) by Doppler flow wire. Flow velocity increase by a factor greater than 2 was considered normal. Quantitative coronary angiography was used to assess epicardial vasomotor function in response to the same stimuli. Myocardial iNOS and cNOS gene expression were detected by semiquantitative reversed transcriptase polymerase chain reaction. Plasma nitrite levels (μM) were measured by spectrophotometry. Cytokines (TNF-a, IL-6; pg/ml) were measured by enzyme linked immunosorbent assay. In 26.1 % of patients (n = 11; group A) an impaired endothelium dependent CFVR (1.65 ± 0.23 increase) was observed; in 73.9 % (n = 31, group B) a normal endothelium dependent CFVR (3.0 ± 0.7 increase; P = 0.003) was observed. Myocardial iNOS and cNOS gene expression did not differ between the two groups. Transcardiac cytokine production was noted in 58.8 % of patients for IL-6 and in 53.3 % for TNF-α. Coronary sinus (CS) levels of TNF-α, IL-6 and nitrite were higher in group A. A significant increase in nitrite production was found only in patients with impaired endothelium dependent CFVR (aorta: 43.9 ± 3.7 vs CS: 52.8 ± 5.6, P = 0.05), suggesting transcardiac nitric oxide production. In addition, CS nitrite levels correlated with CS TNF-a levels in patients with impaired CFVR (r = 0.44, P = 0.003). Microvascular endothelium dependent CFVR is impaired in 26 % of patients early after HTx. Activation of cytokines and the NO pathway seem to be involved in this vasomotor dysfunction The association between cardiac nitric oxide production and TNF-a in this group indicates a chronic high immunologic process, which may represent an early and important target for therapy and prevention of TxCAD.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1432-2277
    Schlagwort(e): Key words Immunoadsorption ; Ig-Therasorb ; Hyperacute xenograft rejection ; Baboon ; Orthotopic xenotransplantation ; Xenoreactive antibodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract To prevent hyperacute xenograft rejection (HXR) caused by preformed natural antibodies (XNAb) after orthotopic heart xenotransplantation (oXHTx) of landrace pig hearts into baboons, we used immunoadsorption of immunoglobulins IgG, IgM and IgA and complement with the reusable Ig-Therasorb column. In addition to functional data, tissue was sampled for histological, immunohistochemical and electron microscopical analysis. We performed three oXHTx of landrace pig hearts to baboons using extracorporeal circulation (ECC) connected to the immunoadsorption unit. Intraoperative treatment consisted of four cycles of immunoabsorption (IA). One oXHTx of a baboon without IA served as a control. A mismatch of donor and recipient heart size was prevented by selecting a 30–40 % lower body weight of donor pigs than recipients. Four cycles of IA removed more than 80 % of IgG, IgM and IgA, 86 % of anti-pig antibodies and 66 % of complement factors C3 and C4 from plasma. The graft of the control animal failed after 29 min. Orthotopic xenotransplantation with IA was selectively terminated after 100 min, 11 h and 21 h, respectively without any histological signs of HXR in light and electron microscopy. After weaning off from ECC these donor xenografts showed sufficient function with normal ECG and excellent cardiac output in echocardiography and invasive measurement (1.93 ± 0.035 l/min). The myocardium of the control xenograft demonstrated more deposits of Ig and complement components (C3, C4) than in the IA group. Baboons survive HXR after orthotopic pig heart xenotransplantation due to antibody depletion by reusable Ig-Therasorb column treatment. Long-term survival in an orthotopic baboon xenotransplantation model after IA, especially in combination with transgenic pig organs, could be a reliable preclinical trial for future clinical xenotransplantation programs.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1432-2277
    Schlagwort(e): Key words Nitric oxide ; Endothelin ; Humans ; Heart transplantation ; Endothelial function
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Endothelial dysfunction precedes and predicts transplant vasculopathy. We investigated the relationship between endothelial dysfunction and the vasoactive mediators nitric oxide and endothelin, 33.7 ± 2.0 days after heart transplantation. Coronary flow was measured in 18 patients to determine the endothelial microvascular vasomotor response to acetylcholine. Endomyocardial biopsies were taken to determine the levels of gene expression of isozymes of endothelin and nitric oxide synthases (NOS). Blood samples from the coronary sinus and aorta were withdrawn for measurement of endothelin, nitrite and cytokines. Five patients (30 %) showed an impaired coronary flow reserve response to acetylcholine, significantly higher inducible NOS gene expression and significant transcardiac nitrite production. Plasma nitrite correlated with tumour necrosis factor-alpha levels in coronary sinus and a transcardiac net extraction of endothelin was noted in all patients. In conclusion, 30 % of patients develop endothelial dysfunction early after heart transplantation; this correlates with the expression and activation of vasoactive and immunomodulatory mediators, which may predict the development of transplant vasculopathy.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...