湖南省畜禽肿瘤的调查研究——Ⅵ.牛白血病普查

本文报道了利用琼脂扩散试验,对湖南省境内21个牛场的奶牛、黄牛和水牛以及一个县农户的水牛进行的牛白血病检查的结果。     

Canine T‐Zone Lymphoma: Unique Immunophenotypic Features,Outcome, and Population Characteristics

Background

Canine T‐cell lymphoma (TCL) is clinically and histologically heterogeneous with some forms, such as T‐zone lymphoma (TZL), having an indolent course. Immunophenotyping is an important tool in the classification of TCL in people, and can be equally useful in dogs.

Hypothesis/Objectives

We hypothesized that loss of expression of the CD45 antigen is a specific diagnostic feature of TZL.

Animals

Twenty dogs with concurrent histology and immunophenotyping by flow cytometry were studied in depth. An additional 494 dogs diagnosed by immunophenotyping were used to characterize the population of dogs with this disease.

Methods

Lymph node biopsies from 35 dogs with TCL were classified by 2 pathologists using WHO criteria. Twenty lymph nodes were from dogs with CD45− TCL and 15 were from CD45+ TCL. The pathologists were blinded to the flow cytometry findings. Outcome information was sought for the 20 dogs with CD45− lymphoma, and population characteristics of the additional 494 dogs were described.

Results

All 20 CD45− cases were classified as TZL. The 15 CD45+ cases were classified as aggressive TCL and are described in an accompanying paper. TZL cases had a median survival of 637 days. Examination of 494 additional dogs diagnosed with TZL by immunophenotyping demonstrated that 40% of cases are in Golden Retrievers, are diagnosed at a median age of 10 years, and the majority have lymphadenopathy and lymphocytosis.

Conclusions

TZL has unique immunophenotypic features that can be used for diagnosis.     

PIG7 and valproic acid promote differentiation and apoptosis of human leukemia SKNO-1 cells

AIM: To investigate the synergistic effect of p53-inducible gene 7 (PIG7) and histone deacetylase (HDAC) inhibitor valproic acid (VPA) on the differentiation and apoptosis of human leukemia SKNO-1 cells.METHODS: The DNA fragments containing PIG7 open reading frame or antisense oligonucleotides were subcloned into lentiviral vector. SKNO-1 cells were transduced with prepared lentivirus. Transgene expression was detected by semi-quantitative RT-PCR and Western blotting. The expression of myeloid cell differentiation antigen CD11b and the apoptotic cells were analyzed by flow cytometry. DNA fragmentation analysis was also used to observe the apoptosis of SKNO-1 cells.RESULTS: VPA inhibited the proliferation of SKNO-1 cells in a dose-　and time-dependent manner. Compared with control group, the differentiation and apoptosis of SKNO-1 cells were significantly induced by ectopically expressed PIG7 (P<0.05). The apoptosis induced by ectopically expressed PIG7 was further enhanced by VPA treatment (P<0.05), and the typical DNA ladders were also observed. The proportion of CD11b+ SKNO-1 cells notably increased after infection with lentivirus containing PIG7 as compared with empty vector group (P<0.05). Up-regulation of PIG7 also enhanced the susceptibility of the cells to the induction of differentiation by VPA.CONCLUSION: VPA inhibits the proliferation and induces the differentiation and apoptosis of SKNO-1 cells. Enforced expression of PIG7 enhances the differentiation and apoptosis of SKNO-1 cells and promotes the sensitivity of SKNO-1 cells to VPA. Over-expression of PIG7 combined with VPA may provide a new strategy for treatment of leukemia.     

Clonal expansion and specific cytotoxicity of autologous or allogeneic T cells induced by M2a cells

AIM: To investigate clonal expansion and specific cytotoxicity of TCR Vβ subfamily T cells from acute myelogenous leukemia M_2a subtype (AML-M_2a)patients and normal individuals induced by AML-M_2a cells, respectively. METHODS: Complementarity determining region 3(CDR3) of TCR β with variable region genes was amplified in autologous or allogeneic T cells from mixed lymphocyte and tumor culture (MLTC) using RT-PCR. The positive products were further analyzed to identify the clonality of T cells by genescan. The specific cytotoxicity of T cells was analyzed by MTT. RESULTS: T cells from both M_2a patients and normal individuals after MLTC showed high response to M_2a cells with 4-17 TCR Vβ subfamily dominant utilization, one or two clonal expansion of T cells were identified in some predominant TCR Vβ subfamilies. Difference of distribution and clonal expansion of TCR Vβ subfamily T cells were related to source of T cells and the phase during MLTC. Compared with LAK cell, most of T cells from MLTC were CD3⁺CD8⁺T cells with higher and more specific cytoxicity to the induced cells, M_2a cells, but not HL60 or K562 cell line. CONCLUSION: Clonal expansion of TCR Vβ subfamily T cells stimulated selectively by M_2a cells may be a specific immune response of autologous and allogeneic T cells to M_2a cells associated antigen. The T cells induced by M_2a cells have the ability of specific cytoxicity to the AML-M_2a cells.     

Progress in the study on establishment and characteristics of viral L6565 cell clone

The biological characteristics of viral L6565 leukemia cell clone were as follows: (1) The chromosome counts varied 38～114 , and stem cells were 42; (2) Virus particles type A and type C found in the cytoplasm of clone cells; (3) X-C assays were positive, c-myc and c-fos gene overexpressed in clone cells; (4) Differential markers CD4, CD8, CD45R were negative, CD45RO λ were positive; (5) The supernatant of clone cells could induce T or B lymphocytic leukemia/lymphoma and granulocytic leukemia in SSB strain mice. The leukemogenic effect of concentrate supernatant was stronger than non-concentrate supernatant (P<0.05); (6) The antisense of the c-myc gene induced low expression of c-myc protein, and inhibited the growth of viral L6565 clone cells.     

Molecular evidence supporting Ehrlichia canis-like infection in cats

Currently, the pathogenic role of Ehrlichia canis in cats has been proposed predominantly on the basis of the serologic evidence of natural infection and the infrequent detection of morulae-like structures within the cytoplasm of leukocytes in cats. The purpose of this report was to provide molecular evidence supporting E. canis-like infection in 3 cats that had clinical manifestations consistent with canine ehrlichiosis but lacked antibodies to E. canis antigens. Serum from all 3 cats contained antinuclear antibodies (ANAs). The predominant disease manifestation was polyarthritis in 1 cat and bone marrow hypoplasia or dysplasia. accompanied by pancytopenia or anemia and thrombocytopenia, in 1 cat each. The alignment of E. canis partial 16S ribosomal DNA (rDNA: 382 nucleotide positions), amplified from EDTA blood samples from each cat, was identical to each other and was identical to a canine isolate of E. canis (GenBank accession number AF373613). In 1 cat, concurrent treatment with corticosteroids may have interfered with the therapeutic effectiveness of doxycycline for the elimination of E. canis-like infection. To further define the spectrum of ehrlichiosis in cats, polymerase chain reaction (PCR) testing may be necessary until serologic testing is thoroughly validated in experimentally or naturally infected cats. In addition, until E. canis has been isolated from cats and several tissue culture isolates are available from disparate geographic regions for detailed comparative genetic study, the molecular evidence presented in this study supporting E. canis-like infection in cats must be interpreted with caution.     

MicroRNA-3666 regulates expression of phosphatase and tensin homologue deleted on chromosome ten in leukemic cells

AIM: To explore the regulatory effect of microRNA-3666 (miR-3666) on the expression of its target gene phosphatase and tensin homologue deleted on chromosome ten (PTEN) in leukemic cells. METHODS: miR-3666 expression levels in normal peripheral blood mononuclear cells and leukemic cells were determined by quantitative real-time PCR. miR-3666 targeting PTEN 3-untranslated region (3UTR) was predicted by TargetScan software. 3UTR of PTEN was inserted in the dual luciferase reporter vector psiCHECK2. The reporter activity was evaluated by the Dual-Luciferase Reporter Assay System after the luciferase promoter vector and miRNA were co-transfected into HEK293T cell line. K562 cells were transfected with synthetic miR-3666 inhibitor (anti-miR-3666) or a synthetic control miRNA (anti-miR-C). The expression of PTEN protein in the above transfected K562 cells was determined by Western blotting. RESULTS: miR-3666 was up-regulated in the human leukemic cell lines and primary leukemic cells compared to normal peripheral blood mononuclear cells. The results of dual luciferase assays validated PTEN as a specific target gene of miR-3666. Inhibition of miR-3666 resulted in an up-regulation of PTEN protein expression in the K562 cells. CONCLUSION: miR-3666 is over-expressed in leukemic cells. The abnormal over-expression of miR-3666 may play a key role in leukemia due to the down-regulation of PTEN.     

Marine anemia in farmed chinook salmon (Oncorhynchus tshawytscha): Development of a working case definition

Marine anemia (plasmacytoid leukemia) is a histologically defined syndrome affecting farmed chinook salmon (Oncorhynchus tshawytscha) in British Columbia, Canada. Although the disease has received recent attention and has been diagnosed in many fish farms, past criteria for diagnosis have limited the depth and breadth of epidemiological investigations. By identifying a repeatably diagnosable subset of signs and symptoms of affected fish, a new working case definition of marine anemia was developed. This definition relied exclusively on histological features to achieve the diagnosis. The intra-observer repeatability of diagnoses using the new definition was high ( κ = 0.84). An algorithm employing gross pathological signs was created for field investigation of the disease. The algorithm was capable of predicting histological diagnosis with a reasonable level of accuracy, and was judged to be a valuable tool for diagnostic decisions. We concluded that by using the case definition created in this study together with the algorithm, the comparability and accuracy of clinical and epidemiological research of marine anemia could be improved.     

Antagonistic effect of angiotensin II type 1 receptor blocker candesartan on angiotensin II-induced proliferation of primary acute myeloid leukemia cells

AIM: To explore the antagonistic effect and mechanism of candesartan on angiotensin II (Ang II)-induced proliferation of primary acute myeloid leukemia (AML)cells. METHODS: MTT assay was used to observe the proliferation effect of Ang II on primary AML cells and normal bone marrow mononuclear cells, and the antagonistic effects of candesartan and PD123319 (an antagonist of AT2R) were also observed. Akt phosphorylation was detected by Western blotting when the cells were treated with candesartan and a PI3K inhibitor LY294002.RESULTS: Compared with the control cells, Ang II significantly increased the proliferation of AML cells in a dose-and time-dependent manner (P<0.05). Ang II did not stimulate the proliferation of normal bone marrow mononuclear cells. The proliferative effect of Ang II was effectively blocked by the AT1R blocker candesartan (P<0.05). PI3K inhibitor strongly repressed the Ang II-induced cell proliferation (P<0.05). Candesartan significantly reduced Akt phosphorylation promoted by Ang II on primary AML cells (P<0.05).CONCLUSION: Candesartan effectively inhibits Ang II-induced proliferation of primary AML cells by down-regulating PI3K/Akt signaling pathway, indicating a new possible treatment mechanism in some AML cells.