Tunneling nanotubes(TNT) are cellular communication and transport mechanism discovered recently. TNTs play important role in immunological response and viral spread, also may involve embryonic development, regulation of gene expression and carcinogenesis. However, it was not easy to study TNT for clinical samples since intricate assay method for TNT. We suggested using histochemical assay PAS staining in cell drip to show TNT in leukemia and lymphoma samples.

Objective To observe the effect of extracorporeal shock waves (ESW) therapy on avascular necrosis of femoral head (ANFH) of stage IV. Methods 72 hips of 44 patients with ANFH of stage IV, according to Association Research Circulation Osseous, were randomly divided into treatment group (n=37) and control group (n=35). The control group received routine therapy, while the treatment group received ESW in addition, 2.0-4.0 bar, 10 Hz, 6000 times. They were evaluated with Harris Hip Score, Manual Muscle Test (MMT) and Short Form of health survey (SF-36) before and 1 month after treatment. Results The scores of Harris Hip Score and MMT improved more in the treatment group than in the control group (P<0.05) after treatment, as well as the scores of SF-36 except physical health and vitality (P<0.05). Conclusion The ESW can obviously improve the motor function and quality of life of patients with ANFH of stage IV.

Objective To study the value of MR three-dimensional volumetric interpolated breath-hold examination(3D-VIBE)and conventional MR imaging (including MRCP) in diagnosing cholangiocarcinoma early and evaluating the respectability of cholangiocarcinoma. Methods 20 patients with malignant obstruction of bile duct were scaned by conventional MR imaging(including MRCP) and dynamic-enhanced 3D-VIBE triple-phase acquisitions. MR imaging features of the tumors were analysed and the re-spectability of cholangiocarcinoma was also evaluated. The differences between conventional MR imaging and 3D-VIBE in displaying the tumors and the infiltration extent of the tumors were compared. Results The sensitivity ratio in showing the tumors were 85 and 95% with conventional MR imaging and 3D-VIBE, respectively, and there was statistically significant difference between two sequences in displaying infiltration of adjacent organs by the tumors(P<0.05). Conclusion 3D-VIBE is superior to conventional MR imaging in the early diagnosis,preoperative assessment of the infiltration extent and the tumor respectability of cholangiocarcino-ma.

The disturbance of life rhythm exerts negative influence on modem life.The relationship between the disruption of circadian rhythms and tumor growth has attracted much attention.It has been studied in breast cancer and prostate cancer,and chronotherapeutics has been used for treatment of some cancers in clinic.Researchers have begun to investigate the association of circadian rhythms with leukemia/lymphoma outside China.The literatures were reviewed and the launch of research on this field was appealed.

Objective To investigate the effects and possible mechanisms of decitabine on heat-shock protein 22 (HSP22) expression in hematopoietic tumor cell lines and bone marrow samples from patients with hematopoietic tumor.Methods The expression of HSP22 in 13 hematopoietic tumor cell lines,20 primary patients' samples and 10 normal donor' samples were detected by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR).After HSP22 induction with a demethylating agent decitabine (2 μmol/L),the methylation of the HSP22 promoters in hematopoietic tumor cell lines,healthy donors and bone marrow samples from patients with hematopoietic tumor were detected by methylation specific PCR (MSP).Results Expression of HSP22 was not detected in 13 hematopoietic tumor cell lines,20 primary patients' samples or 10 healthy donors' samples.Decitabine can induce the expression of HSP22 in hematopoietic tumor cell lines and bone marrow samples from patients with hematopoietic tumor.Decitabine can maintain partially demethylation of HSP22 promoters in hematopoietic tumor cell lines.HSP22 promoters were highly methylated in BMMC of the healthy donors and patients with hcmatopoictic tumor.Conclusion Decitabine can induce the expression of HSP22 in hematopoietic tumor cells partly by demethylation of HSP22 promoters.

Human herpesvirus 6 (HHV-6) is recognized as a ubiquitous dsDNA virus in human with widespread cell tropism in vivo, which could induce lifelong latent infection and be reactivated in some immunocompromised individuals leading to serious diseases. With the increasing application of hematopoietic stem cell transplantation (HSCT), it is obvious that HHV-6 reactivation has a close relationship with several complications including encephalitis after transplantation. On the other hand, among about 1 % infected people, HHV-6 and subtelomeric region of cell chromosomes in the state of endogenous persistent infection play a part in activated virus infection. As the detection methods make a great progress in HHV-6 detection, clinical data reveals the relationship between HHV-6 reactivation and lots of chronic diseases, especially lymphoma, leukemia as well as some chronic hematopoietic and immunological diseases.

Cancer stem cells (CSCs) are units in cancer evolution.The elucidation the origin of CSCs has great significance on prevention and treatment of cancers.This paper discusses possible origins,genetic pathways and mechanisms of CSC on the basis of the literature and authors' research.Normal stem cells could be malignantly transformed to CSC through long term accumulation of gene mutations.Induction to pluripotent stem cells by reprogramming is a possible pathway for somatic cells to become CSCs.Dedifferentiation of cancer cells to CSCs is another pathway.Epithelial-mesenchymal transition (EMT),which is an important mechanism for cellular plasticity,plays important roles in cancer metastasis and stemness of cancer cells.Cell-fusion inducing EMT could be a mechanism for the genesis of CSCs.Infection of some virus is also related to the genesis of CSCs.The complexity of cancer biology was also discussed.

Allee effect is a phenomenon in ecology characterized by a correlation between population size or density and the mean individual fitness of population or species.It is consistent with density dependent phenomenon in biomedical field.Recently,Allee effect has been studied by theoretical biologist in detail for oncology biological research.Leukemia cells,which reside in organic microenvironment,show an obvious Allee effect.The authors compared Allee effect with density dependent growth of leukemia cells based on their work experience and literature data.No principle distinction was found between these two terms.In this paper,Allee effect in leukemia cell culture and leukemia,especially in minimal residual disease,will be discussed in the view of ecology.The association between Allee effect and leukemogenesis and relapse dynamics will also be explored in the future research.

Viral etiology of tumor has been studied for a century.Seven human tumor viruses were identified over the past half century.The complexity and regularity of the pathogenic mechanisms of human tumor viruses have been elucidated preliminarily.Human genome sequencing indicated that 8 ％ of human genes were composed of human endogenous retroviruses (HERVs).Owing to the findings that adult T-cell leukemia virus (HTLV) can cause human adult T-cell leukemia and animal exogenous and HERVs can induce tumors and malignant diseases,the relationship between HERVs and human tumors has attracted much attention receutly.Here this article discusses the association of the expression of HERVs with leukemia and solid tumors progression,which may be an important aspect of tumor virology.

As novel organisms,tumors undergo microevolution in limited time and space in vivo.Due to genetic mutations and epigenetic mechanisms,tumor cell clones undergo linear or branching evolution.In most clinic patients,tumors develop through branching evolution pathways,causing tumor heterogeneity and affecting tumor progression.Microevolution is the biological basis for the refractoriness and recurrence of tumors and has been paid attention in research and clinic recently.In this paper,acute myeloid leukemia (AML) and myelodysplastic syndromes (MDS) are used as examples to demonstrate tumor microevolution and the concept of linear and branching evolution.Questions and perspective in the field of tumor microevolution research are also discussed.