ABSTRACT
Objective:To evaluate the safety of leadless pacemaker implantation in super-elderly patients.Methods:Eleven patients with average age of 90 (86, 92) years who underwent leadless pacemaker implantation in the Department of Cardiology, Peking University People′s Hospital from March 2021 to May 2022 were included. The clinical data and implantation information were collected. The complications (cardiac tamponade, myocardial infarction, cerebral infarction, pulmonary embolism, pacemaker reinfection, femoral vein hematoma) and death of patients were documented at 24 h, 3 d, and 1, 3, 6 months after pacemaker implantation.Results:There were 9 males and 2 females with the body mass index of 21(19, 23)kg/m 2. The underlying diseases were hypertension, diabetes, coronary heart disease, chronic kidney disease, chronic obstructive pulmonary disease, previous cerebral infarction and moderate to severe tricuspid regurgitation in 9, 9, 9, 6, 4, 4, 4 patients, respectively. The left ventricular ejection fraction was 49% (45%, 52%), the hemoglobin concentration was 118 (114, 122)g/L, 4 patients were taking anticoagulant drugs, and 6 patients were taking antiplatelet drugs. Eight patients were newly implanted with a leadless pacemaker, 2 patients were implanted after removal the old ones, and 1 case was implanted at the same time as removal. The implantation time was 45(40, 47) minutes, the X-ray exposure time was 14 (13, 15) minutes, the release time was 1 (1, 2), the threshold value was 0.50(0.38, 0.75)V/0.24 ms, the impedance was 730 (700, 770) Ω, and the perceived R-wave amplitude 8.2(6.7, 12.8) mV. During the follow-up period of 8 (6, 10) months, no patient had pacemaker dysfunction; and the threshold, R wave sensing, and impedance were stable and maintained within the normal range. No cardiac tamponade, myocardial infarction, cerebral infarction, pulmonary embolism, pacemaker reinfection or death occurred perioperatively and during the follow-up period; 1 patient had hematoma after femoral vein puncture, which improved after compression treatment. Conclusion:This single-center and small-sample study shows that leadless pacemaker implantation is safe for super-elderly patients.
ABSTRACT
BACKGROUND:L-type calcium channels, as a kind of voltage-dependent calcium channel, is the main way of extracellular calcium ions into the cell, and play an important role in maintaining cellmorphology and physiological activities, characterized by a large single-channel conductance, slow channel attenuation, and longer duration of channel opening. Previous studies showed that basic fibroblast growth factor can promote the proliferation of chondrocytes cultured in vitro. OBJECTIVE:To explore the effect of the L-type calcium channels on regulating chondrocyte proliferation and differentiation in response to basic fibroblast growth factor with patch-clamp. METHODS:The chondrocytes were harvested from the joints of 3-day-old New Zealand rabbits. The second passage of chondrocytes was divided into experimental group and control group. Chondrocytes were incubated in media containing 10μg/L basic fibroblast growth factor and media alone separately. The opening of L-type calcium channels under the action of basic fibroblast growth factor was detected by patch-clamp. The intracellular calcium concentration was detected with laser confocal microscopy in the chondrocytes after 2 weeks of culture with basic fibroblast growth factor. Chondrocyte proliferation was analyzed by cellTiter kit after 8 days of culture. Type Ⅱ col agen was assessed quantitatively by immunohistochemistrical staining after 10 days of culture. RESULTS AND CONCLUSION:Basic fibroblast growth factor has an inhibitory effect on the opening of the L-type calcium channels, resulting in a decrease in intracellular free calcium concentration (P<0.01). cellnumber was higher after culture with basic fibroblast growth factor than that cultured under conventional condition (P<0.01), and staining area of type II col agen significantly increased (P<0.05). Results verified that basic fibroblast growth factor can maintain intracellular Ca2+concentration at a low level by inhibiting the opening of L-type calcium channels, which can promote the proliferation and differentiation of chondrocytes.
ABSTRACT
The inactivation efficiencies of microorganisms were found to be enhanced by using silver solution together with ultraviolet light (UV-A, 395 nm) irradiation. The inactivation efficiencies were improved remarkably especially in eukaryotic microorganism. To make clear the inactivation mechanism of microorganisms by the combination effect of silver and ultraviolet light irradiation, the resultant solution was characterized by ESR (Electron spin resonance, ESR). Scanning electron microscopy (SEM) and the methnd for measuring enzyme activity of mitochondria for eukarvotic cells were used to conjecture the mechanism, by analysis of the morphological and physiologic changes in eukaryotic cells. It is proposed that silver oxide (Ag20) can be activated by ultraviolet light irradiation and react with water molecules to produce hydroxyl radical (.OH). Hydroxyl radical could damage cell wall of eukaryotic microorganisms, and inactivate the enzyme activity of mitochondria of eukaryotic microorganism cells. Accordingly, eukaryotic microorganism cells would die. In the experiment, Staphylococcus aureus was employed as the representative of prokaryotic microorganisms, and Candida albicans and Trichophyton mentagrophytes as the representative of eukaryotic microorganisms, respectively. Moreover, the results of the technology applied to washing machine were presented and discussed.