Sequestration patterns of transfused rat neutrophilic granulocytes under normal and inflammatory conditions

Abstract: The fate of polymorphonuclear neutrophilic granulocytes (PMN) after their mobilization from the bone marrow of healthy individuals is not clearly understood. It has been suggested that there is a continuous utilization of these cells in widespread, subclinical inflammatory foci, where they are ultimately degraded. The goal of the present experiments was to determine whether an alternative ecotaxis (“homing”) exists, namely sequestration and degradation of PMN by mononuclear phagocytes exposed to the bloodstream in the liver, spleen and bone marrow. Blood PMN were collected from donor rats, labelled with ⁵¹Cr, and injected i.v. into 2 syngeneic rats, one of them having an induced sterile peritonitis. After various time intervals up to 18 h, the rats were killed and exsanguinated. As expected, we found cell-bound radioactivity in the inflamed peritoneal cavities, and also a high amount of radioactivity in liver, spleen, and bone marrow. The bone marrow uptake of PMN appeared to be much lower in the inflammation rats than in the normal controls. These findings were confirmed in PMN transfer experiments using PVG rats congenic for the RT7 alloantigenic system. Here, transfused blood leukocytes were traced with fluorescent, monoclonal HIS41 antibodies and flow cytometry. A possible corticosteroid effect on the bone marrow sequestration could not be substantiated. Uptake and degradation of PMN takes place in organs containing phagocytes exposed to the bloodstream. Sequestration of PMN in the bone marrow is apparently down-regulated in inflammatory states, perhaps increasing the PMN availability to inflamed tissue.     

Cr:LiSAF激光在组织自体荧光光谱研究中的应用

目的　该文以Cr:liSAF激光作为激发光源 ,针对生物大分子设计了荧光实验 ,以探讨其在组织自体荧光研究中的应用。方法　氙灯泵浦Cr:LiSAF二次谐波用来产生可调谐蓝光脉冲激光输出 ,并设计了自体荧光试验。结果　最后设计并实现了可调谐蓝光脉冲激光输出 ,得到了良好的输出特性。结论　氙灯泵浦Cr:LiSAF二次谐波产生可调谐蓝光脉冲激光输出得到了良好的输出特性 ,该实验为进一步研究肿瘤组织与正常组织自体荧光产生机制打下了基础。     

Er，Cr：YSGG激光对牙周炎患牙及健康牙根面的影响

目的：探讨应用RFPT5-14工作尖的Er, Cr: YSGG激光照射对牙周炎患牙及健康牙根面微观结构改变以及粗糙度的影响。方法：选取8颗因牙周炎拔除的患牙，用超声刮治器去除根面牙石，另选取8颗因正畸减数或阻生智齿拔除的健康牙，将每颗牙根面分为4个区域，对应为1~4组，分别进行如下4种处理：（1）不处理；（2）Gracey刮治器进行根面平整30 s；（3）低功率激光照射30 s；（4）高功率激光照射30 s。通过扫描电镜观察表面微观结构，通过三维光学轮廓仪测量表面粗糙度Ra值。结果：手工根面平整组的表面可见玷污层覆盖；激光照射组表面较清洁，可见消融样改变；高功率激光组可见局部有牙本质小管暴露。牙周炎患牙第1组的Ra值为（237.4±20.0） nm，第2~4组的Ra值分别为（135.7±11.9） nm（P=0.01）、（463.6±49.3） nm（P<0.001）和（486.0±59.0） nm（P<0.001）。健康牙第1组的Ra值为（191.4±44.5）nm，第2~4组的Ra值分别为（131.6±21.5） nm（P=0.482）、（463.7±34.6） nm（P<0.001）和（470.3±121.3） nm（P<0.001）。结论：应用RFPT5-14工作尖的Er, Cr: YSGG激光照射可造成牙周炎表面的病变牙骨质及健康牙表面的健康牙骨质微观结构的改变，可以有效减少根面玷污层，并可见有消融样改变。Er, Cr: YSGG激光照射可以增加根面粗糙度，还需进一步实验来评价激光照射后根面的生物相容性。     

A Ca2+ chelator ameliorates chromium (VI)-induced hepatocyte L-02 injury via down-regulation of voltage-Dependent anion channel 1 (VDAC1) expression

Hexavalent chromium could result in cell malfunctions. Intracellular Ca²⁺ ([Ca²⁺]_i) content and VDAC1 expression are both important features related to cell survial. This study aimed to explore the mechanism of cell injury induced by Cr(VI) and tentatively offer clues to repairing this cell damage using [Ca²⁺]_i and VDAC1. L-02 hepatocytes were treated with Cr(VI)/BAPTA, and the levels of [Ca²⁺]_i and cell injury associated with Cr(VI) were determined in addition to the effect of BAPTA. The expression of VDAC1 in Cr(VI)-induced cells was evaluated. The results showed a dose-dependent elevation of the level of VDAC1 and the mRNA level of the VDAC1 biogenesis-related gene Sam50. BAPTA could ameliorate less severe damage induced by 4 μM Cr(VI) via reducing VDAC1 and Sam50. Additionally, cell injury caused by less than 4 μM Cr(VI) could be ameliorated by VDAC1 knockdown. Taken together, the findings of this study suggest that inhibition of intracellular Ca^2± overload could protect cells from damage and that VDAC1 plays a considerable role in Cr(VI)-induced liver injury.     

Lithium di silicate ceramic surface treated with Er,Cr:YSGG and other conditioning regimes bonded to orthodontic bracket

AimTo assess bond integrity and modes of failure of metallic brackets to lithium disilicate ceramics (LDC) conditioned with Er,Cr:YSGG laser (ECL).Material and methodsSixty LDC were arbitrarily allocated into six groups (n = 15) according to the type of ceramic surface conditioning treatment. Group 1 surface treated with silane (S) only, group 2 surface etched with hydrofluoric acid (HF)+ S, group 3 surface conditioned with HF+ ultrasonic bath (UB)+ S, group 4 sand blasting (SB) of glass ceramic surface with 50 µm Al₂O₃, group 5 surface conditioned with self-etch ceramic primer (SECP) and in group 6 surface treated with ECL + S. After conditioning, the specimens were positioned in a universal testing device for shear bond strength (SBS) testing. Adhesive Remnant Index (ARI) was used to determine sites of bond failure. Among experimental groups analysis of variance (ANOVA) and Tukey multiple comparison test was used at a significance level of (p < 0.05).ResultsThe highest SBS values were observed in group 3 HF+ UB + S (18.21 ± 1.241) and the lowest SBS values were displayed group 1 surface treated with S only (5.21 ± 0.23). Specimens surface conditioned in group 2 with HF+ S (17.85 ± 1.25), group 3 HF+ UB + S (18.21 ± 1.241) and group 6 ECL + S (17.09 ± 1.114) unveiled comparable SBS values (p > 0.05).ConclusionLDC conditioned with ECL at (4.5 W and 30 Hz) has a potential to be used in clinical settings alternate to HF acid.     

Er,Cr:YSGG激光在根管治疗中的应用进展

铒、铬:钇钪镓石榴石(erbium,chromium:yttrium scandium gallium garnet laser,Er,Cr:YSGG)激光在牙科领域主要应用于根管治疗术、牙周疾病、龋病、牙本质过敏症、牙髓切断术等。本文从根管封闭性、灭菌、空穴效应和对根尖周组织影响四个方面对Er,Cr:YSGG激光在根管治疗中的研究进展作一综述。文献复习结果表明,Er,Cr:YSGG功率为2~4 w,20 Hz时,可以较好清除牙本质小管玷污层,从而提高材料与牙本质之间的密闭性;Er,Cr:YSGG能量产生的热效应具有灭菌作用,而牙体的光导性使冲洗液能够进入更深的组织,进一步提高灭菌效果;Er,Cr:YSGG还具有空穴效应,破坏深处溶液的表面张力,从而可以清除深层的玷污层与细菌;但是在相同功率下Er,Cr:YSGG如果使用不当,Er,Cr:YSGG产生的热效应会对根尖周组织造成一定伤害,因此,合理的Er,Cr:YSGG使用时间长短和在水冷却条件下是重要的。     

Intestinal permeability to [51Cr]EDTA in infectious diarrhea

Orally administered [⁵¹Cr]EDTA was used to measure intestinal permeability in subjects with infectious diarrhea and in those without gastrointestinal complaints. [⁵¹Cr]EDTA was given to 87 subjects: 63 controls (32 normal controls, and 31 disease controls), and 24 patients with infectious diarrhea. Approximately 100 Ci of [⁵¹Cr]EDTA was given orally after an overnight fast. Urine was collected for the following 24 hr. Intestinal permeability to [⁵¹Cr]EDTA in both normal volunteers and in patients with a variety of diseases not associated with intestinal injury was low and results were in a relatively narrow range. Mean 24-hr urinary excretion of [⁵¹Cr]EDTA, calculated as a percent of the administered dose, in controls was 1.6% (0.2–3.5%). Patients with infectious diarrhea associated with invasive pathogens and/or intestinal inflammation had increased excretion of [⁵¹Cr]EDTA (mean 6.1%,P<0.0001), with elevated excretions in 75%. These results demonstrate that intestinal infections must be considered as possible causes for increased intestinal permeability as assessed by the [⁵¹Cr]EDTA test.