Suppressing memory T cell activation induces islet allograft tolerance in alloantigen‐primed mice

Memory T cells are known to play a key role in prevention of allograft tolerance in alloantigen‐primed mice. Here, we used an adoptively transferred memory T cell model and an alloantigen‐primed model to evaluate the abilities of different combinations of monoclonal antibodies (mAb) to block key signaling pathways involved in activation of effector and memory T cells. In the adoptively transferred model, the use of anti‐CD134L mAb effectively prevented activation of CD4⁺ memory T cells and significantly prolonged islet survival, similar to the action of anti‐CD122 mAb to CD8⁺ memory T cells. In the alloantigen‐primed model, use of anti‐CD134L and anti‐CD122 mAbs in addition to co‐stimulatory blockade with anti‐CD154 and anti‐LFA‐1 prolonged secondary allograft survival and significantly reduced the proportion of memory T cells; meanwhile, this combination therapy increased the proportion of regulatory T cells (Tregs) in the spleen, inhibited lymphocyte infiltration in the graft, and suppressed alloresponse of recipient splenic T cells. However, we also detected high levels of alloantibodies in the serum which caused high levels of damage to the allogeneic spleen cells. Our results suggest that combination of four mAbs can significantly suppress the function of memory T cells and prolong allograft survival in alloantigen primed animals.     

Forensic efficiency parameters of the Investigator Argus X-12 kit in women from two Mestizo and seven Amerindian populations from Mexico

Allele frequency distribution and statistical parameters of forensic efficiency concerning the Investigator Argus X-12 kit (Qiagen, Hilden, Germany) were determined in a total sample of 641 unrelated Mexican females, including two Mestizo–admixed– populations (n = 309) and seven Amerindian groups (n = 332) from the main regions of the country. Most of the 12 X-STRs were in agreement with Hardy-Weinberg expectations in all nine Mexican populations. The power of discrimination in females (PD) and Median exclusion chance for trios (MEC_T) and duos (MEC_D) of this genetic system based on X-STRs were >99.99%. Although Mexican populations showed significant pairwise differentiation, a closer relationship was evident between Amerindian groups and nearby Mestizos, in agreement with historical records, previous genetic studies, and X-linked inheritance pattern expectations.     

Z-LLY-FMK Attenuates Intestinal Apoptosis After Bile Duct Ligation in Rats

Apoptosis is an important process in a wide variety of different biological systems. In addition to caspases, recently, calpains, another family of proteases, have been found to be involved in apoptosis of many cell systems. This study is designed with the aims to evaluate the possible effect of Z-LLY-FMK (a calpain inhibitor) on intestine apoptosis after bile duct ligation in rats. Male Sprague–Dawley rats weighing 250–300 g were randomized to five groups (n = 6 in each group). Group 1 (Control: C) underwent Sham operation and were simultaneously treated with the same amount of normal saline. Group 2 (Control with DMSO: CDMSO) underwent Sham operation and were simultaneously treated with the same amount of dimethylsulfoxide (DMSO). Group 3 (Obstructive jaundice: OB) underwent common bile duct ligation without any other manipulation. Group 4 (Obstructive jaundice with Z-LLY-FMK: OBZLLY) underwent common bile duct ligation and were simultaneously treated with Z-LLY-FMK (dissolved in DMSO). Group 5 (Obstructive jaundice with ZFA-FMK: OBZFA) underwent common bile duct ligation and were simultaneously treated with ZFA-FMK (dissolved in DMSO). After 3 days, intestine tissue was harvested for apoptosis measurements. There was no significant difference between Sham operation group (C) and Sham operation with DMSO group (CDMSO) either in jejunum (P = 0.924) or in ileum (P = 0.996). When compared to Sham operation group (C), increased intestine apoptosis occurred in either jejunum (P < 0.001) or in ileum (P < 0.001) after common bile duct ligation (OB). After administration of Z-LLY-FMK (OBZLLY), the increased intestine apoptosis after common bile duct ligation (OB) was significantly diminished either in jejunum or in ileum (P < 0.001 and P < 0.001). Moreover, administration of ZFA (OBZFA) failed to show the same phenomenon in either jejunum (P = 0.993) or ileum (P = 0.485). There was a significant difference in intestine apoptosis in either jejunum (P < 0.001) or in ileum (P < 0.001) between OBZLLY group and OBZFA group. Significantly increased intestine apoptosis occurred after common bile duct ligation. The administration of Z-LLY-FMK could effectively diminish the intestine apoptosis after common bile duct ligation, whereas the administration of ZFA-FMK failed to show the same effect.     

Liver virtual non-enhanced CT with dual-source, dual-energy CT: a preliminary study

Purpose

To compare virtual non-enhanced liver CT (VNCT) from dual-energy CT (DECT) with true non-enhanced liver CT (TNCT) in patients.

Methods

A total of 102 patients underwent multi-phase abdominal CT. Liver arterial VNCT (VNCT_A) and portovenous VNCT (VNCT_V) images were derived from the arterial and portovenous DECT data. The mean CT number, signal to noise ratio (SNR), image quality, contrast to noise (CNR) of liver lesions, lesion detectability and radiation dose were compared.

Results

There was no difference in mean CT numbers of all organs (all P?>?0.05). SNR on VNCT images was higher than that of TNCT (all P?<?0.001). Image quality of VNCT was diagnostic but lower than that of TNCT (P?<?0.001). VNCT_A images were superior to VNCT_V (P?<?0.001). VNCT_A and VNCT_V detected 78 (91%) and 70 (81%) of 86 hepatic focal lesions visualised on TNCT. There was no difference in the size, attenuation and CNR of focal hepatic lesions (all P?>?0.05), but SNR of the lesions on VNCT was higher than that on TNCT (P?<?0.001). Radiation dose of biphase DECT was lower than that of routine triphase CT (P?<?0.001).

Conclusion

VNCT_A may potentially replace TNCT as part of a multi-phase liver imaging protocol with consequent saving in radiation dose.     

Relationship between ketamine-induced developmental neurotoxicity and NMDA receptor-mediated calcium influx in neural stem cell-derived neurons

Ketamine, a noncompetitive NMDA receptor antagonist, is used as a general anesthetic and recent data suggest that general anesthetics can cause neuronal damage when exposure occurs during early brain development. To elucidate the underlying mechanisms associated with ketamine-induced neurotoxicity, stem cell-derived models, such as rodent neural stem cells harvested from rat fetuses and/or neural stem cells derived from human induced pluripotent stem cells (iPSC) can be utilized. Prolonged exposure of rodent neural stem cells to clinically-relevant concentrations of ketamine resulted in elevated NMDA receptor levels as indicated by NR1subunit over-expression in neurons. This was associated with enhanced damage in neurons. In contrast, the viability and proliferation rate of undifferentiated neural stem cells were not significantly affected after ketamine exposure. Calcium imaging data indicated that 50 μM NMDA did not cause a significant influx of calcium in typical undifferentiated neural stem cells; however, it did produce an immediate elevation of intracellular free Ca²⁺ [Ca²⁺]_i in differentiated neurons derived from the same neural stem cells.This paper reviews the literature on this subject and previous findings suggest that prolonged exposure of developing neurons to ketamine produces an increase in NMDA receptor expression (compensatory up-regulation) which allows for a higher/toxic influx of calcium into neurons once ketamine is removed from the system, leading to neuronal cell death likely due to elevated reactive oxygen species generation. The absence of functional NMDA receptors in cultured neural stem cells likely explains why clinically-relevant concentrations of ketamine did not affect undifferentiated neural stem cell viability.     

蛋白激酶C和JNK在溶血磷脂酸诱导人肺成纤维细胞MCP-1表达中的作用

目的：研究蛋白激酶C（PKC）和c-Jun氨基末端激酶（JNK）在溶血磷脂酸（LPA）诱导人肺成纤维细胞（HLF-1）单核细胞趋化蛋白-1（MCP-1）表达中的作用。方法：培养HLF-1细胞,以不同浓度（0、1、3和10 μmol/L）的LPA处理细胞不同时间（0.5、6、12和24 h）后,ELISA检测细胞培养基上清液中MCP-1的蛋白表达,荧光定量PCR检测MCP-1 mRNA的表达水平。用不同浓度的PKC抑制剂Bisindolylmaleimide I（0、0.1、1和10 μmol/L）或JNK抑制剂SP600125（0、0.1、1和10 μmol/L）预孵育细胞30 min后,用LPA（10 μmol/L）刺激2或6 h后,ELISA方法检测细胞培养基上清液中MCP-1的蛋白表达,荧光定量PCR检测MCP-1 mRNA的表达水平。用PKC抑制剂Bisindolylmaleimide I（1 μmol/L）预孵育30 min,以浓度为10 μmol/L的LPA处理细胞不同时间（0、5、30和60 min）后,Western blot检测c-Jun蛋白磷酸化水平。结果：LPA可诱导HLF-1细胞MCP-1蛋白释放,并呈剂量效应和时间效应关系。LPA的浓度为10 μmol/L时,HLF-1细胞释放MCP-1蛋白的量是对照组的2.4倍（P < 0.05）;细胞在LPA处理24 h后,MCP-1蛋白的释放量较对照组增加约1倍（P < 0.05）。LPA可诱导HLF-1细胞MCP-1 mRNA的表达并呈时间效应,LPA处理2 h后,MCP-1 mRNA表达水平是对照组的5.3倍（P < 0.05）。PKC抑制剂Bisindolylmaleimide I和JNK抑制剂SP600125均可显著抑制LPA诱导的HLF-1细胞MCP-1 mRNA表达及MCP-1蛋白释放。Bisindolylmaleimide I的浓度为1 μmol/L时可阻断LPA诱导的HLF-1细胞MCP-1蛋白释放量的60%（P < 0.05）,浓度为3 μmol/L时对MCP-1 mRNA表达有明显抑制效果,抑制率达40%（P < 0.05）;而SP600125的浓度为1 μmol/L时可阻断LPA诱导的HLF-1细胞MCP-1蛋白释放量的78%（P < 0.05）,对MCP-1 mRNA表达有明显抑制效果,抑制率达87%（P < 0.05）。10 μmol/L的LPA可显著诱导HLF-1细胞c-Jun磷酸化,同时PKC抑制剂Bisindolylmaleimide I（1 μmol/L）可显著抑制LPA（10 μmol/L）诱导的HLF-1细胞c-Jun磷酸化。结论：PKC与JNK通路均参与LPA诱导HLF-1细胞MCP-1的表达。     

Three-dimensional CT angiography study on the relations between the vertebral artery and atlantoaxial joint

Background The vertebral artery （VA） and atlantoaxial joint （AAJ）, with complicated structures, are located in the depths of the head-neck boundary area, the regional anatomy of which cannot be shown globally and directly. This study aims to evaluate three-dimensional CT angiography （3DCTA） in displaying the AAJ, atlantoaxial segment of the vertebral artery （ASVA） and the identification of their interrelations. Methods Sixty-eight subjects without pathology of the ASVA and AAJ were selected from head-neck CTA examination. All the 3D images were formed with volume rendering （VR） together with techniques of separating, fusing, opacifying and false-coloring （SFOF）. On the 3D images, the ASVA and AAJ were observed, and their interrelations were measured. Results All the 3DCTA images were of high quality and up to our requirements. They could clearly and directly show the ASVA, ascending along the AAJ. There were 5 curves in the course of the ASVA, of which 2 curves were away from the atlantoaxial joint, one in the 2rid curve of 0.0 mm-5.4 mm, the other in the 4th of 2.6 mm-9.2 mm. There was no significant difference in the measurements between left and right （P 〉0.05）. The curved parts of the ASVA slightly expanded, with the biggest diameter of 5.6 mm in the 4th curve. Statistical comparison shows that the left ASVA is larger than the right （P 〈0.05）. Variations of the ASVA were found in 8 cases and of the AAJ in 12. Conclusions 3DCTA can globally and directly demonstrate the structures of the AAJ, ASVA and their interrelations. The 3D imaging data make up and enrich the research contents of regional anatomy and lay the foundation for related study and applications.