The debate on the cell of origin of human retinoblastoma lasted for more than one century.In the recent issue of "cell",David Cobrinik's group shows that L/M cone precursors are the most likely answer as they have an intrinsic circuitry,including murine double minute 2 (MDM2),N-myc,the nuclear receptors retinoid X receptor and thyroxine receptor 2,making them extremely sensitive to transformation following retinoblastoma gene inactivation.

Children with retinoblastoma (RB) typically survive their cancer due to advances in early diagnosis and treatment. Extraocular invasion and metastasis, and secondary malignant tumor carry a very high mortality rate. Prerequisites for metastasis include tumor initiating capacity, altered cellular adhesion and cell motility, resistance to extracellular death signals and disruption of the basement membrane and extracellular matrix. All those changes can be determined by the cell of origin and the genetic instability of the tumor, responding to the multiple layers of pressure such as hypoxia, from the tumor microenvironment or niche. The interaction between tumor cells and the tumor stroma is regulated by several metastasissuppressor proteins and microRNA. This knowledge has important implications for our understanding and the treatment of extraocular spreading of RB.

Retinoblastoma (RB) therapy has evolved over decades.In the 1970s, enucleation was important for improving life prognosis.In the 1980s, external beam radiotherapy (EBRT) was popular.In the 1990s, systemic intravenous chemotherapy (IVC) was introduced and currently remains prevalent worldwide for intraocular RB control as well as prevention of systemic metastasis.However, RB seeds in vitreous and subretinal space are still the major obstacles for successful treatments.Advanced ophthalmic imaging technology promotes thorough and detailed description and observation of RB seeds.In the 2000s, interests in periocular chemotherapy (POC), intra-arterial chemotherapy (IAC) and intravitreous chemotherapy (IVitC) have been explored to overcome the low drug concentration around the seeds and to reduce the systemic side effects.This leads us into a new era of target local chemotherapy of RB.How to make the treatment decision based on biological behavior of RB seeds is a major task for us now.

Retinoblastoma (RB) and choroidal malignant melanoma are the most common primary intraocular malignancy in children and adults, respectively.Due to the advance in the diagnosis and treatment of intraocular tumors, the survival rate and survival time of the patients are significantly improved.The goal of the therapy for the patients of intraocular malignant tumors has gradually changed from simply saving life to trying to preserve eyeball on the basis of saving life.Although there are various treatment options for intraocular malignant tumors, eye salvage is still an great challenge for the patients with refractory tumors.In recent years, vitrectomy has been used again by some doctors to the treatment of refractory RB and choroidal malignant melanoma, which undoubtedly gives the hope of eye salvage to the patients with intraocular malignant tumors.However, this therapy arouse controversy because serious intraoperative or postoperative complications occurred in some patients.Ophthalmologists should select suitable indications for this surgery cautiously, perform the operation carefully, combine other chemotherapy and/or radiotherapy and local treatment and close follow-up if necessary.

Stem cells are crucial for embryonic development and in the maintenance of adult cellular homeostasis.Understanding the regulatory network of stem cells,including embryonic and adult stem cells,will allow us to learn the pathogenesis and possibly design novel approaches to treat many diseases (such as cancer and degeneration).The retinoblastoma (Rb) pathway controls cellular proliferation,differentiation and death.More and more evidences support an important role of Rb activity in the biology of stem and progenitor cells.Transiently inactivating Rb pathway might favor the expanding of functional stem cell populations,thus have values in the future stem cell applications.

OBJECTIVE: To summarize the development of researches on sildenafil for treating cardiovascular patients with erectile dysfunction, so as to explore the safety of applying sildenafil and efficacy of treating related cardiovascular diseases.DATA SOURCES: The relevant articles to sildenafil between October 1999 and February 2006 were computer-searched in PubMed databasewith the key words of "sildenafil, erectile dysfunction, sexuality, cardiovascular disease" in English. Meanwhile, Medscape database was scanned with computer to identify relevant articles with key words of "sildenafil, cardiovascular disease". STUDY SELECTION: After the primary searching, literatures on relationship between sildenafil and cardiovascular disease were searched in full-text, while articles about erectile dysfunction but had nothing to do with cardiovascular disease were excluded. The repetitive experimental studies were also deleted. DATA EXTRACTION: A total of 55 articles were collected, and 22 of them were in accordance with the inclusion criteria and their full-texts were carefully looked through. DATA SYNTHESIS: The selected data were classified according to the relationship between erectile dysfunction and cardiovascular disease, effect of sildenafil on erectile dysfunction of patients with heart disease and rec ommendation of the Princeton conference. CONCLUSION: It is demonstrated in many literatures that the potential risk of sildenafil triggering cardiovascular disease is relatively small. Cardiac patients need not promote huge concerns when resorting to sildenafil for erectile dysfunction treatment. However, the protective cardiac effects of sildenafil should be further investigated.

Purpose [WT5”BZ]To estabalish a quantifying model of retinal neovascularization suitable for the study of pathogenesis and therapeutic intervention for the retinal neovascularization. [WT5”HZ]Methods [WT5”BZ]Sixteen one week old C 57 BL/6 mice were exposed to 75% oxygen for 5 days and then to room air and 16 mice of the same age kept in room air as controls.Ink perfused retinal flatmount was examined to assess the oxygen induced changes of retinal vessels.The proliferated neovascular response was quantitated by counting the nuclei of endothelial cells of new vessels extending from the retina into the vitreous in 6 ?m sagittal cross sections. VEGF and bFGF were determined on the cross sections after immunohistochemcal stain. [WT5”HZ]Results [WT5”BZ]Constriction and closure of the blood vessels were found under the hyperoxia condition,and dilation and proliferation were found under the relatively hypoxia status.There was a mean of 24 neovascular nuclei per cross section in the oxygen treated retina and less than 1 nucleus in the control group ([WT5”BX]P

Purpose To investigate nucleoside diphosphate kinase (NDPK ) expression of tumor metastasis suppressor gene nm23 in heterotransplanted model of retinoblastoma(RB) in nude mice,and analyse the correlation between the expression of nm23 gene and the formation and progression of heterotransplanted RB. Methods SP immunohistochemical method was used to detect the expression of nm23 gene product NDPK in 20 tumors of heterotransplanted RB model and normal retinal tissue. Results The negative staining of nm23/ NDPK was found in normal retinal tissue , whereas 100% expression rate in RB tumors with positive number of 48.73?2.37. No statistical significance of the expression of nm23/ NDPK was observed between the intraocular growth phase (I～Ⅲ grade) and invasive phase (Ⅳ～Ⅴ grade) in heterotransplantedRB tumors. Conclusion The function of nm23 gene as a tumor metastasis suppressor in heterotransplanted RB tumors was less prominent ,but it may play a role in carcinogenesis and progrssion of RB and may predict poor prognosis.

BACKGROUND:Hepatocyte growth factor(HGF) is a kind of multifunctional growth factor,which can accelerate cell growth,transition and genesis in various organs.In cardiovascular system,HGF has reported to have anti-apoptotic,anti-fibrotic,as well as repair endothelial cell injury effects,suppose that HGF has relationships with hypertension.OBJECTIVE:To investigate the effect of HGF on blood pressure,vascular endothelial system and renin-angiotensin system(RAS) in spontaneously hypertensive rats,further more,to discuss the mechanisms between HGF and hypertension.DESIGN,TIME AND SETTING:The randomized control experiment on animal was performed at the Department of Cardiology,First Affiliated Hospital of Anhui Medical University from March to July 2007.MATERIALS:The exogenous HGF power was purchased from America Peprotech Company.Rats with 14-weeks-old,weighting 200-250 g,were randomly divided into the experimental and spontaneous hypertension groups,WKY rats were serves as the control group,with 12 animals in each group.METHODS:Rats in the experimental group were administrated 5,10,15,20,and 25 ?g/kg HGF per 24 hours,the partes aequales sodium chloride was injected into the spontaneous hypertension and control groups.Five minutes after administration,systolic pressure and heart rates were measured.The rats were sacrificed and harvested 2 mL blood of right ventricle when blood pressure decrease the lowest,about 30 minutes after administration.MAIN OUTCOME MEASURES:The effect of HGF on systolic pressure and heart rates,and levels of serum nitrogen monoxidum(NO),plasma endothelin(ET),as well as angiotensinⅡ(Ag Ⅱ) were detected by colorimetry and radio-immunity methods.RESULTS:When injected 5?g/kg HGF,the blood pressure did not significantly change.After 10 ?g/kg HGF injection,the blood pressure began to decrease and reached a peak after 30 minutes,gradually recovered after 1 hour,and back to the normal after 5 hours.Injection of 20 ?g/kg has largest effect on rats,with reduced contractive pressure 40-50mmHg,but no significantly changes appeared by adding HGF dose.There were no significantly differences of heat rate and blood pressure between the two control groups.Compared with the spontaneous hypertension group,the levels of ET and AgⅡ were decreased,however,the level of NO was increased(P

In order to strengthen the education for university students’all-round devel-opment,and to improve the quality of teaching,Shantou University,by making good use of higher education resources,built a digital campus consisting of virtual classrooms based on advantage of computer and Internet network environment,and plenty of general education programs were carried out.The teaching practice showed that virtual classroom,as a network platform,played an important role in general education programs.