Effective cleavage of phosphodiester promoted by the zinc(II) and copper(II) inclusion complexes of ß-cyclodextrin.

To construct the model of metallohydrolase, two inclusion complexes [MLCl2(ß-CD)] (1, M=Zn(II); 2, M=Cu(II); L=N,N'-bis(2-pyridylmethyl)amantadine; ß-CD=ß-cyclodextrin) were synthesized by mixing ß-CDs with the pre-synthesized complexes G1, [ZnLCl2] and G2, [CuLCl2]. Structures of G1, G2, 1 and 2 were characterized by X-ray crystallography, respectively. In solution, two chloride anions of G1 and G2 underwent ligand exchange with solvent molecules according to ESI-MS analysis. The chemical equilibrium constants were determined by potentiometric pH titration. The kinetics of bis(4-nitrophenyl) phosphate (BNPP) hydrolysis catalyzed by G1, G2, 1 and 2 were examined at pHs ranging from 7.50 to 10.50 at 308±0.1K. The pH profile of rate constant of BNPP hydrolysis catalyzed by 1 exhibited an exponential increase with the second-order rate constant of 2.68×10-3M-1s-1 assigned to the di-hydroxo species, which was approximately an order of magnitude higher than those of reported mono-Zn(II)-hydroxo species. The high reactivity was presumably hydroxyl-rich microenvironment provided by ß-CDs, which might effect in stabilizing either the labile zinc-hydroxo species or the catalytic transition state.

[Change in serum basic fibroblast growth factor level and its relationship to pulmonary arterial pressure in patients with acute exacerbation of chronic cor pulmonale on plateau].

OBJECTIVE: To assess the role of serum basic fibroblast growth factor (bFGF) in the development of hypoxic pulmonary hypertension in the patients with chronic cor pulmonale on highland (HACCP). METHODS: The levels of bFGF in serum of 38 patients with HACCP in the acute exacerbation stage, 30 patients with chronic obstructive pulmonary disease (COPD) in the remission stage and 30 normal control subjects were measured by sandwich enzyme-linked immunoadsorbent assay (ELISA). The mean pulmonary arterial pressure (MPAP) was measured by echocardiography. The partial pressure of oxygen in artery blood (PaO(2)) was measured by blood gas analyzer. RESULTS: The level of serum bFGF [(87.54+/-12.15) ng/L] and MPAP [(45.86+/-5.63)mm Hg (1 mm Hg=0.133 kPa)] in the patients with HACCP were significantly higher than those in the patients with COPD [(55.72+/-9.08) ng/L, (22.95+/-2.56)mm Hg, respectively, both P<0.01], those of the patients with COPD were both significantly higher than those of the normal control subjects [(49.83+/-8.78)ng/L, (20.34+/-2.23)mm Hg, respectively, both P<0.05]. The PaO(2) [(38.79+/-4.56)mm Hg] in the patients with HACCP was significantly lower than those in patients with COPD and normal subjects [(58.22+/-6.18) mmHg and (66.57+/-5.48)mm Hg, respectively, all P<0.01]. The level of serum bFGF in the patients with HACCP and the patients with COPD was positively correlated with MPAP (cor pulmonale group r=0.788, P<0.01; COPD group r=0.674, P<0.01)],negatively correlated with PaO(2) (cor pulmonale group r=-0.735, P<0.01; COPD group r=-0.587, P<0.01)). CONCLUSION: The level of serum bFGF in patients with HACCP is significantly increased; it may play an important role in the process of sustained hypoxic pulmonary hypertension in patients with HACCP.

[Study on the clinical significance of plasma adrenomedullin and brain natriuretic polypeptide in the patients with chronic cor pulmonale on highland].

OBJECTIVE: To study the clinical significance of plasma adrenomedullin (ADM) and brain natriuretic polypeptide (BNP) in the patients with chronic cor pulmonale on highland (HACCP). METHODS: The levels of ADM and BNP in plasma of 44 patients with HACCP in the acute and in the remission stages were determined with radioimmunoassay. Their correlations with partial pressure of oxygen in arterial blood (PaO(2)), endothelin-1 (ET-1), and the ratio of right ventricular pre-ejection time to the pulmonary flow acceleration time (RVPEP/AT), which reflected the degree of pulmonary hypertension, were investigated. Twenty healthy subjects served as a normal control group. RESULTS: The levels of ADM [(38.8+/-7.2)ng/L and (26.2+/-5.3)ng/L] and BNP [(81.4+/-13.8)ng/L and (58.9+/-9.3)ng/L] in the acute and remission stages of cor pulmonale groups were both significantly higher than those in the normal control group [(15.0+/-3.2)ng/L, (38.6+/-3.4)ng/L, respectively, all P<0.01]. The levels of ADM and BNP in acute stage were both significantly higher than those in remission stage (both P<0.01). In the acute and in the remission stages, the levels of ADM in plasma were negatively correlated with PaO(2) (r(a)=-0.826, P<0.01; r(r)=-0.783, P<0.01), positively correlated with ET-1 (r(a)=0.755, P<0.01; r(r)=0.668, P<0.01) and RVPEP/AT ratio (r(a)=0.788, P<0.01; r(r)=0.734, P<0.01). In the acute and in the remission stages, the levels of BNP in plasma were negatively correlated with PaO(2) (r(a)=-0.787, P<0.01; r(r)=-0.554, P<0.01), positively correlated with ET-1 (r(a)=0.725, P<0.01; r(r)=0.679, P<0.01) and RVPEP/AT ratio (r(a)=0.771, P<0.01; r(r)=0.722, P<0.01). CONCLUSION: The study suggests that ADM and BNP are involved in the pathophysiological process of HACCP in the patients and may play a compensatory role in the disease.