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Biomedical subjects

Michael A Kerr

Publications and source records attributed to Michael A Kerr.

25 records · Page 2Linked to original sources
PubMed2004

Inflammatory response in an immunosuppressed patient with Wegener's granulomatosis.

BACKGROUND: The use of cardiopulmonary bypass (CPB) triggers a systemic inflammatory response (IR), but it is not known if a similar response occurs in an immunosuppressed patient with autoimmune disease. METHODS AND RESULTS: Observational study in a 56-year-old man receiving immunosuppressive therapy for Wegener's granulomatosis (WG) who underwent aortic valve replacement on CPB. The following markers for IR were studied in the perioperative period: C3a, C5a, neutrophil elastase (NE), interleukin eight (IL-8), white cell count (WCC) and C-reactive protein (CRP). Results were compared with published literature on the IR in patients undergoing coronary revascularisation with and without the use of CPB. All inflammatory markers increased in the perioperative period. The intensity of IR was markedly reduced compared to published literature for patients undergoing coronary revascularisation on CPB and the temporal patients and extend resembled that for off-pump. CONCLUSION: In a patient with WG on immunosuppressive therapy the CPB-related IR is reduced.

Aortic Valve Insufficiency↗
PubMed2003

The total synthesis of (+)-hapalindole Q by an organomediated Diels-Alder reaction.

The total synthesis of (+)-hapalindole Q has been achieved. The key step is a Diels-Alder reaction mediated by MacMillan's organocatalyst to provide the critical intermediate with high enantioselectivity (93% ee). This step establishes the proper arrangement of the required four contiguous stereocenters, including the quaternary center, and represents the first successful application of an enantioselective organomediated Diels-Alder reaction in total synthesis.

Cyanobacteria↗
PubMed2003

Structural and functional consequences of cleavage of human secretory and human serum immunoglobulin A1 by proteinases from Proteus mirabilis and Neisseria meningitidis.

The cleavage of human serum monomeric immunoglobulin A1 (IgA1) and human secretory IgA1 (S-IgA1) by IgA1 proteinase of Neisseria meningitidis and cleavage by the proteinase from Proteus mirabilis have been compared. For serum IgA1, both proteinases cleaved only the alpha chain. N. meningitidis proteinase cleaved only in the hinge. P. mirabilis proteinase sequentially removed the tailpiece, the CH3 domain, and the CH2 domain. The cleavage of S-IgA1 by N. meningitidis proteinase occurred only in the hinge and was as rapid as that of serum IgA1. P. mirabilis proteinase predominantly cleaved the secretory component (SC) of S-IgA1. The SC of S-IgA1, whether cleaved or not, appeared to protect the alpha1 chain. Purified Fc fragment derived from the cleavage of serum IgA1 by N. meningitidis proteinase stimulated a respiratory burst in neutrophils through Fcalpha receptors, whereas the (Fcalpha1)(2)-SC fragment from digested S-IgA1 did not. The loss of the tailpiece from serum IgA1 treated with P. mirabilis proteinase had little effect, but the loss of the CH3 domain was concurrent with a rapid loss in the ability to bind to Fcalpha receptors. S-IgA1 treated with P. mirabilis proteinase under the same conditions retained the ability to bind to Fcalpha receptors. The results are consistent with the Fcalpha receptor binding site being at the CH2-CH3 interface. These data shed further light on the structure of S-IgA1 and indicate that the binding site for the Fcalpha receptor in S-IgA is protected by SC, thus prolonging its ability to activate phagocytic cells at the mucosal surface.

Binding Sites↗
PubMed2002

Convenient preparation of indolyl Malonates via Carbenoid insertion.

Indoles, when treated with methyldiazomalonate under catalysis by rhodium(II)acetate, undergo C-H and N-H insertion reactions regioselectively depending on the substitution pattern on the indole moiety. In indoles where the 3-position is unsubstituted, high yields of the C3-H insertion product were observed. In 3-alkylindoles, 2-substitution predominated, while N-methyltetrahydrocarbazole yielded the product resulting from insertion into the C6-H bond. Indoles in which the nitrogen is unprotected yield varying degrees of N-H insertion.

Journal Article↗