结直肠癌淋巴管生成与淋巴结转移相关检测的临床研究进展

结直肠癌是人类常见的可经淋巴道转移的恶性肿瘤,其淋巴管生成与转移过程中牵涉了多种生物标志物表达水平的改变,检测这些相关生物标志物可为结直肠癌的诊断、治疗和预后情况提供重大参考价值．本文主要综述近年来与结直肠癌淋巴管生成与淋巴结转移相关检测的临床研究进展．     

A bicistronic retrovirus vector containing a picornavirus internal ribosome entry site allows for correction of X-linked CGD by selection for MDR1 expression

Chronic granulomatous disease (CGD) is an inherited hematologic disorder involving failure of phagocytic cell oxidase to produce superoxide (O2-.), resulting in recurrent infections. The success of retrovirus gene therapy for hematopoietic diseases will be limited both by the efficiency of ex vivo transduction of target cells and by the ability of corrected cells to replace uncorrected cells in vivo. Using MFG-based retrovirus vectors containing oxidase genes, we have previously demonstrated in vitro correction of CGD, but transduction rates were low. In the present study we explore a strategy for providing a selective growth advantage to transduced cells, while retaining the single promoter feature of MFG responsible for high virus titer and enhanced protein production. We constructed a bicistronic retrovirus producing a single mRNA encoding both the therapeutic gene for the X-linked form of CGD (X-CGD), gp91phox, and the selectable human multidrug resistance gene, MDR1 linked together by the encephalomyocarditis virus internal ribosome entry site (IRES). As a control we constructed a bicistronic vector with the polio virus IRES element and using the bacterial neomycin resistance gene (neor) as the selective element. In Epstein-Barr virus transformed B (EBV-B) cells from an X-CGD patient, a tissue culture model of CGD, we show correction of the CGD defect and complete normalization of the cell population using either of these vectors and appropriate selection (vincristine for MDR1 and G418 for neor). Using a chemiluminescence assay of O2-. production, populations of cells transduced with either vector demonstrated initial correction levels of from less than 0.1% up to 2.7% of normal EBV-B cell oxidase activity. With either construct, cell growth under appropriate selection enriched the population of transduced cells, resulting in correction of X-CGD EBV-B cells to a level of O2-. production equalling or exceeding that of normal EBV-B cells. These studies show that a therapeutic gene can be linked to a resistance gene by an IRES element, allowing for selective enrichment of cells expressing the therapeutic gene. Furthermore, the use of MDR1 as a selective element in our studies validates an important approach to gene therapy that could allow in vivo selection and is generalizable to a number of therapeutic settings.     

Predominant role of catalase in the disposal of hydrogen peroxide within human erythrocytes

Purified enzymes were mixed to form a cell-free system that simulated the conditions for removal of hydrogen peroxide within human erythrocytes. Human glutathione peroxidase disposed of hydrogen peroxide (H2O2) at a rate that was only 17% of the rate at which human catalase simultaneously removed hydrogen peroxide. The relative rates observed were in agreement with the relative rates predicted from the kinetic constants of the two enzymes. These results confirm two earlier studies on intact erythrocytes, which refuted the notion that glutathione peroxidase is the primary enzyme for removal of hydrogen peroxide within erythrocytes. The present findings differ from the results with intact cells, however, in showing that glutathione peroxidase accounts for even less than 50% of the removal of hydrogen peroxide. A means is proposed for calculating the relative contribution of glutathione peroxidase and catalase in other cells and species. The present results raise the possibility that the major function of glutathione peroxidase may be the disposal of organic peroxides rather than the removal of hydrogen peroxide.     

Severe hemolytic anemia due to multiple red cell alloantibodies after an ABO-incompatible allogeneic bone marrow transplant

BACKGROUND: A patient who received an ABO-incompatible allogeneic bone marrow transplant experienced three episodes of immune hemolytic anemia due to multiple red cell (RBC) alloantibodies. CASE REPORT: A 41-year- old man with chronic myeloid leukemia received an ABO-incompatible bone marrow graft from his HLA-identical brother. Selective removal of RBCs from donor marrow before transfusion was performed by centrifugation using a continuous-flow blood cell separator. The patient was given group O Rh-positive RBCs and group A Rh-positive platelets. Prophylaxis for graft-versus-host disease consisted of cyclosporine and methotrexate. The patient experienced three hemolytic episodes, on Days 21, 35, and 160 which were due to different RBC alloantibodies (anti-K, anti-Jk(b), anti-M, IgG anti-A) produced by host lymphocytes surviving the conditioning regimen. RESULTS: The patient was group O, Jk(b-), and the marrow donor was group A, Jk(b+). After the first hemolytic episode (Day 21), immunohematologic studies showed group O RBCs and a positive direct antiglobulin test (IgG+, C3d+). Antibody screening test and eluate studies detected anti-M, anti-Jk(b), and anti-K. During the second hemolytic episode (Day 35), the patient's blood group showed a mixed population of group A and group O RBCs. The direct antiglobulin test was positive (IgG+, C3d+). Anti-M, anti-Jk(b), and IgG anti-A were detected in the serum. Eluates made from the recipient's RBCs showed the same specificity as serum antibodies. During the third hemolytic episode (Day 160), a mixture of group O and group A RBCs was still present, the direct antiglobulin test was positive (IgG+, C3d-), and anti-Jk(b) and IgG anti-A were observed in the serum and in an eluate made from the patient's RBCs. CONCLUSION: This is the first reported case of severe immune hemolytic anemia due to multiple RBC alloantibodies after an allogeneic bone marrow transplant. The time of appearance and the specificity of the antibodies strongly suggest that they were produced by residual recipient lymphoid cells.     

Interleukin-4 stimulates human monocytes to produce tissue-type plasminogen activator

Tissue-type plasminogen activator (t-PA) is involved in the lysis of blood clots (fibrinolysis) and is used clinically for this purpose. Endothelial cells are one source of the t-PA present in blood. We report here that interleukin-4 (IL-4) (0.1 to 0.25 U/mL; 1 to 3 x 10(- 11) mol/L), but not interferon-gamma (IFN-gamma), elevates t-PA messenger (m)RNA expression and secretion of t-PA activity by human monocytes, with the maximum response at 2.5 U/mL. Supernatant t-PA activity was detected within three hours of exposure to IL-4 and maximum activity within six hours. Thus, IL-4 may control fibrin deposition at sites of inflammation during cell-mediated immune responses, as well as having a therapeutic role in thrombolysis.     

Hesperidin protects against behavioral alterations and loss of dopaminergic neurons in 6-OHDA-lesioned mice: the role of mitochondrial dysfunction and apoptosis

Metabolic Brain Disease - Hesperidin is a flavonoid glycoside that is frequently found in citrus fruits. Our group have demonstrated that hesperidin has neuroprotective effect in 6-hydroxydopamine...     

Protein-Derived Acetaminophen-Cysteine Can Be Detected After Repeated Supratherapeutic Ingestion of Acetaminophen in the Absence of Hepatotoxicity

Generation of protein-derived acetaminophen-cysteine (APAP-CYS) is reported after ingestion of large and therapeutic dosages of acetaminophen in healthy and in liver-damaged patients. The incidence of protein-derived APAP-CYS adducts in repeated supratherapeutic dosages of APAP is not known. Methods: for 12 months, a standardized and comprehensive questionnaire was used to interview every consecutive patient at a pain management clinic. Patients found to ingest more than 4 g of APAP per day for a minimum of 14 consecutive days at the time of the encounter were invited to have blood drawn for hepatic transaminases and APAP-CYS adduct levels. Twelve subjects out of 990 interviewees met inclusion criteria. Ten of the 12 had measurable protein-derived APAP-CYS, none had evidence of liver injury. Patients that ingest repeated supratherapeutic amounts of APAP over several weeks may generate APAP-CYS protein adducts in the absence of hepatic injury.