The use of beta-adrenoblockers in conjunction with angiotensin converting enzyme inhibitors improves quality of life and prognosis of patients with chronic heart failure. However basic mechanisms of these positive effects in severe heart failure remain to be elucidated. METHODS: Patients (n=54) with NYHA class III-IV heart failure and left ventricular ejection fraction < or =35% were randomized either to treatment with bisoprolol (1.25-10 mg/day) (n=30) or in control group (n=24) and were followed up for 12 months. RESULTS: The use of bisoprolol was associated with significant improvement of heart failure functional class, lowering of heart rate (by 14%, p<0.01), elevation of systolic blood pressure (by 7.2+/-12.3 mm Hg, p<0.01) and increase of walking distance (by 30.1+/-29.0 m, p<0.01). No significant changes of these parameters occurred in control group. After 12 months increases of left ventricular end diastolic and end systolic volumes (by 85+/-69.2 and 71+/-51.5 ml, respectively, p<0.001) and of ejection fraction (by 5.7+/-7.3%, p<0.01) took place in bisoprolol treated patients. These changes were significantly (p<0.001) higher than those in control group. After 6 months of treatment with bisoprolol noradrenaline concentration fell from 533 to 402 pg/ml (p<0.05) while in controls it rose from 369 to 474 pg/ml, p<0.01). Decreases of plasma renin activity (from 1.2 to 0.42 ng/ml/h), plasma concentrations of angiotensin II (from 17.1 to 13.1 pg/ml) and aldosterone (from 173 to 148 pg/ml, p<0.05) were also observed in bisoprolol group. No substantial dynamics of activity of main components of renin angiotensin system took place in controls. There were no significant changes of atrial natriuretic peptide in both groups. Significant positive dynamics of parameters of heart rate variability was registered only in bisoprolol group: SDNN increased by 25% (p<0.05), high frequency spectrum by 106% (p=0.03), LF/HF ratio from 2.18+/-1.41 to 1.82+/-0.7. CONCLUSION: Long term use of bisoprolol was associated with improved clinical and hemodynamic status, increased systolic BP, blocked processes of pathological left ventricular remodeling, lowered activity of not only sympathetic-adrenal but also of main components of renin-angiotensin system and improved heart rate variability. 相似文献
An important biologic function of high-molecular-weight kininogen (HK) is to deliver bradykinin (BK) to its cellular receptors. Internalization and degradation of HK may provide a mechanism by which endothelial cells modulate the production of BK and control its activities. Therefore, we investigated the binding and subsequent distribution of biotinylated-HK (biotin-HK) associated with human umbilical vein endothelial cells (HUVEC). HUVEC bound 3 to 4 times more HK and with greater avidity at 1 to 3 hours at 37 degrees C than at 4 degrees C (Bmax = 1.0 +/- 0.02 x 10(7) molecules/cell, kd = 7 +/- 3 nmol/L v Bmax = 2.6 +/- 0.2 x 10(6) molecules/cell, kd = 46 +/- 8 nmol/L). However, there was no evidence that the difference was caused by internalization of HK at the higher temperature. First, the same amount of biotin-HK was associated with nonpermeabilized and permeabilized HUVEC using buffers containing 20 to 50 mumol/L zinc ion in the absence or presence of 2 mmol/L calcium ion. Second, binding of biotin-HK to HUVEC was approximately 92% reversible at 1 hour when the cells were maintained at both 37 degrees C and 4 degrees C. Third, neither chloroquine nor primaquine altered the amount of biotin-HK bound to HUVEC. Fourth, biotin-HK bound to HUVEC was almost completely removed by pronase. Fifth, the nonpermeable dye, crystal violet, almost completely quenched the fluorescence signal emitted by HUVEC-associated fluorescein isothiocyanate (FITC) HK. Finally, the localization of HUVEC-bound FITC-HK was restricted to the membrane as shown by laser scanning confocal microscopy. The expression of HK binding sites had an absolute requirement for metabolic energy, but was not dependent on new protein synthesis. Membrane-bound HK contributed to the anticoagulant nature of endothelial cells by blocking human alpha-thrombin binding and its resultant induction of prostacyclin formation. These studies indicate that HK is not internalized by HUVEC, but remains primarily on cell surfaces to be accessible for BK liberation and to modulate the binding and actions of alpha-thrombin. 相似文献
Light chain deposition disease (LCDD) results from a propensity of some human monoclonal L chains to form tissue deposits. We designed an experimental model for in vivo expression of human kappa L chain sequences in mice and compared a somatically mutated LCDD chain with a closely related control kappa chain, both encoded by the unique V kappa IV gene. Mice secreting the LCDD chain but not those producing the control chain showed deposits with a distribution similar to that observed in patients. These data show that discrete changes in V region sequences can play a major role in tissue deposition of human L chains. 相似文献
The Ig heavy chain (IgH) gene was used as a marker to investigate clonal succession and the origin of the neoplastic cell in multiple myeloma. The polymerase chain reaction (PCR) was used to amplify a section of the rearranged IgH gene at diagnosis and at progression in 21 patients who had exhibited a plateau phase. A monoclonal PCR product was seen for 16 of the patients and the product present at progression was of the same molecular weight as that at diagnosis. This finding suggests that the IgH rearrangement present at diagnosis and progression was the same. This was confirmed by sequencing the IgH gene in 10 patients. The IgH genes were found to be hypermutated at diagnosis, but no further hypermutation occurred during the course of the disease. The results provide evidence that the neoplastic cell in myeloma may originate as a memory B cell, plasmablast, or plasma cell, and suggest that progression beyond the plateau phase is not caused by clonal succession. 相似文献
Background: To evaluate if TNF inhibitor serum drug levels (DL) or anti-drug antibodies (ADAb) can predict successful dose reduction (in patients with high DL) or discontinuation (in patients with no/low DL or ADAb) in rheumatoid arthritis (RA) patients.
Research design and methods: RA patients that were using adalimumab (n = 42), etanercept (n = 76) or infliximab (n = 51) and were doing well, were tapered until discontinuation or flare (1–1.5 year follow up). Random timed DL for adalimumab and etanercept and trough DL for infliximab were measured before dose reduction: Receiver-Operator-Curves (ROC) analyses with optimal cut-off DL were determined.
Results: No predictive value of adalimumab and infliximab DL for all outcomes were found, except for an inverse association of lower etanercept DL and higher chance for successful dose reduction (Area Under the Curve (AUC) 0.36, 95% CI 0.23–0.49; cut-off <2.6 mg/l). In sub analyses, higher adalimumab trough DL predicted successful dose reduction (AUC 0.86, 0.58–1.00; cut-off >7.8). ADAb were infrequent and not predictive of successful discontinuation.
Conclusions: No predictive value of baseline adalimumab, etanercept and infliximab DL or ADAb for successful dose reduction or discontinuation in RA was found in this context, with the possible exception of high adalimumab trough levels for successful dose reduction. 相似文献
The Film Digital Radiography System (FilmDRS) is a device with a laser optical film digitizer, 2,000 X 2,000 X 12-bit memory, and a 1,000-line video display. To evaluate the adequacy of this device for general radiography of the chest, four readers independently analyzed both radiographs and the corresponding video display of the digitized chest images of 150 patients, consisting of 100 images of abnormalities and 50 normal images. The overall results indicate equal sensitivity for the two systems. The FilmDRS, with interactive windowing, proved superior in the detection of hilar and mediastinal disease. X-ray film was superior in allowing detection of hyperlucent states. There was equivalent sensitivity for other disease categories. Superior specificity was achieved with conventional radiographs. 相似文献