Preparation of a novel targeted MR contrast agent Gd-DTPA-Granzyme B monoclonal antibody / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To prepare a novel MRI targeted contrast agent Gd-DTPA-Granzyme B monoclonal antibody (mAb) and to test its reaction conditions.</p><p><b>METHODS</b>The Granzyme B mAb was coupled with DTPA,and then conjugated with Gd. The Gd-DTPA antibody was characterized using MALDI-TOF-MS. Cytotoxicity test was performed with MTT assay, and immune activation was examined with immunohistochemistry.</p><p><b>RESULT</b>MALDI-TOF-MS demonstrated that the molecular weight shifted from granzyme B mAb (133986) to Gd-DTPA-GB mAb (139736), which indicated the conjugation of the antibody with Gd-DTPA. The molar ratio of Gd per IgG molecule was about 20. MTT assay showed that Gd, DTPA, Gd-DTPA and Gd-DTPA-GB mAb groups did not make an impact on cell viability, and there were no significant differences among 4 groups (P>0.05). Immunohistochemistry results showed that compared with the positive control group the targeted contrast agent had a high immune activity.</p><p><b>CONCLUSION</b>The novel contrast agent Gd-DTPA-Granzyme B mAb prepared in this study keeps a good immune activity and has no significant cytotoxicity.</p>

Changes of sphingolipids profiles after ischemia-reperfusion injury in the rat liver / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Hepatic ischemia-reperfusion (I/R) injury occurs in many clinical procedures. The molecular mechanisms responsible for hepatic I/R injury however remain unknown. Sphingolipids, in particular ceramide, play a role in stress and death receptor-induced hepatocellular death, contributing to the progression of several liver diseases including liver I/R injury. In order to further define the role of sphingolipids in hepatic I/R, systemic analysis of sphingolipids after reperfusion is necessary.</p><p><b>METHODS</b>We investigated the lipidomic changes of sphingolipids in a rat model of warm hepatic I/R injury, by delayed extraction matrix-assisted laser desorption ionization time-of-flight mass spectrometry (DE MALDI-TOF-MS).</p><p><b>RESULTS</b>The total amounts of ceramide and sphingomyelin and the intensity of most kinds of sphingolipids, mainly sphingomyelin, significantly increased at 1 hour after reperfusion (P < 0.05) and reached peaks at 6 hours after reperfusion (P < 0.01) compared to controls. Six new forms of ceramide and sphingomyelins appeared 6 hours after reperfusion, they were (m/z) 537.8, 555.7, 567.7, 583.8, 683.5 and 731.4 respectively. A ceramide-monohexoside (m/z) 804.4 (CMH(d18:1C22:1+Na)(+)) also increased after reperfusion and correlated with extent of liver injury after reperfursion.</p><p><b>CONCLUSIONS</b>Three main forms of sphingolipids, ceramide, sphingomyelin and ceramide-monohexoside, are related to hepatic I/R injury and provide a new perspective in understanding the mechanisms responsible for hepatic I/R injury.</p>

A pilot study of the directional migration of bone marrow-derived stem cells towards glioma in adult rats / 中华神经医学杂志

Objective To study the directional migration of bone rnarrow-derived stenl cells (BMSCs)towards the glioma and the distribution of tbe migrated BMSCs in the brain. Methods In vitro cultured BMSCs isolated from the bone marrow of male Wistar rats were identified using immunofluorescence technique. and their stem cell properties wcrc assessed by means of induced differentiation in vitro into adipocytes and osteoblasts.Wistar rat models bearing glioma were established by stereotactic injection of C6 glioma cells into the basal ganglia,and 7 days later.Brdu-labeled BMSCs werc injected stereotaetically into the contralateral hemisphere or the contralateral ventricle, or intravenously via the tail vein.The rats were sacrificed 14 days afterthe BMSC injection,and coronal paraffin sections(5 μm thick)of the brain tissue were prepared.HE staining was used to observe the extent of intracranial glioma growth,and the distribution of the BMSCs in the glioma tissue as well as in the brain tissue was identified With immunofluorescent staining. ResuIts The BMSCs implanted into either the contrahteral hemisphere or the contralateral ventricle were found to migrate towards the glioma mostly along the needle tract,and distinct green fluorescence emitted by the labeled BMSCs Was detected on the boundary between the glioma and the normal brain tissue.A few fluorescent BMSCs were also seen around the glioma tissue after intravenous injection of the cells. Conclusion BMSCs injected into the cerebral parenchyma,contralateral ventricle,or the tail vein are capable of directional migration into the glioma tissue,suggesting their potential as a new vehicle for delivering therapeutic genes into the glioma tissue.