SOUTHERN ALBERTA CHILDREN'S CANCER PROGRAM

This study examined the salient clinical and epidemiological characteristics of retinoblastoma (RB) in India, thereby highlighting the problems encountered there. The epidemiological characteristics of 296 patients with RB over 8 years were evaluated using hospital records and postal follow-ups. Unilateral disease was seen in 61.8% of patients. The overall median age at presentation was 3.5 years (3.5 years for unilateral RB and 1.0 years for bilateral RB). The male/female ratio was 1.4:1. The median duration of symptomatic disease was 8 months. Consanguineous marriage was seen in 17% and family history of RB was noted in 1.7% cases. Also, 2 % had a history of other malignancy in the family. Associated congenital malformation was seen in 10.5% of cases. A second malignancy was seen in 0.67% of cases at a mean duration of 4.5 years after completion of therapy. A predominance of advanced-stage disease (74.5% had Reese-Ellsworth group TV and V disease) was seen in our series. Only 43.6% of patients had disease localized to the globe without any infiltration/invasion. The majority of cases had advanced-stage disease at presentation and came from the underprivileged class of society. Patients with bilateral RB presented much earlier than those with unilateral disease. In patients with unilateral RB, higher age at presentation as well as advanced disease may be related to much delay in seeking medical attention. In view of the advanced stage at presentation, there also exist a possibility of difference in the biology of the tumor seen in these patients.     

Retroperitoneal sarcomas: A review of disease spectrum,radiological features,characterisation and management

Retroperitoneal sarcomas are a rare disease. The overall 5‐year survival rate for these lesions remains low, and surgical management offers the only option for effective treatment and potential for cure. Radiotherapy is increasingly being employed in addition to standard surgical treatment. Improvements in cross‐sectional imaging have also facilitated better characterisation of lesions, preoperative planning and long‐term follow‐up. This article reviews the current literature and documents the various types of retroperitoneal sarcomas with a particular approach to their imaging features. We also highlight the pathology, diagnostic methods and most current management of these tumours.     

Joining the dots: a plea for precise estimates of the maternal mortality ratio in sub-Saharan Africa

Monitoring of maternal mortality levels in sub-Saharan Africa (SSA) to assess the achievements of safe motherhood programmes and for MDG-5 has been made difficult because of the lack of precise estimates of the maternal mortality ratio (MMR). Projections based on the slow rate of decline of the MMR indicate that MDG-5 may not be reached before the end of this century in this region. Measurements done using demographical and health surveys, statistical modelling and censuses are imprecise and do not allow trends in individual countries to be established. SSA countries should be encouraged to measure mortality levels from their own resources, using methods that produce precise estimates such as population-based surveys. Establishment of the trends will lead to country-specific program targets. The less frequent but more precise measurements can be afforded by SSA countries, as a case study from Zimbabwe shows.     

维A类化合物4-APR抑制肿瘤侵袭、转移的作用

用体内外实验模型,研究了新维A类化合物4-乙酰胺苯基维A酸酯(4-APR)对肿瘤侵袭、转移的抑制作用。4-APR 43.3mg·kg^-1po即能减少小鼠Lewis肺癌的自发性肺转移瘤数。半体内实验证明4-APR10^-5mol·L^-1和10^-6mol·L^-1对B16-F10癌细胞的人工肺转移瘤数分别抑制67.9%和36.6%。体外实验显示,4-APR对B16-F10细胞侵袭重组基底膜的抑制率分别为54.2%和41.9%。     

人端粒酶逆转录酶启动子介导的靶向性肿瘤基因治疗的研究进展

端粒酶与肿瘤发生发展的关系是近年来肿瘤研究领域的热点之一．端粒的磨耗限制大多数体细胞的复制,肿瘤细胞主要通过转录上调端粒酶限制成分催化亚基端粒酶逆转录酶（hTERT）维持端粒长度．由于hTERT启动子区域已被克隆,其特点也已被鉴定,hTERT启动子介导的靶向性肿瘤基因治疗成为研究的热点．我们综述了hTERT启动子介导的靶向性肿瘤基因治疗最新研究进展．     

合欢皮中三萜皂甙元的研究

合欢皮中三萜皂甙元的研究陈四平张如意（北京医科大学植化教研室，北京１０００８３）中药合欢皮（Ａｌｂｉｚｚｉａｅｃｏｒｔｅｘ）为合欢（ＡｌｂｉｚｚｉａｅｊｕｌｉｂｒｉｓｉｎＤｕｒａｚｚ）树皮。具解郁安神，活血消肿功能。用于心神不安，忧郁失眠，肺痈疮肿...     

AUTACOID INTERACTIONS IN THE REGULATION OF BLOOD FLOW IN THE HUMAN PLACENTA

1. Interactions between autacoids may play important roles in the regulation of blood flow in the foetal placenta. In order to investigate this aspect of placental haemodynamics, human normal-term placentae were perfused in vitro and the responses of the foetal vessels to various combinations of vasoactive agents were determined. 2. Vasoconstriction responses to 5-hydroxytryptamine (5-HT) were potentiated in the presence of endothelin-1 (ET-1), the thromboxane A₂-mimetic U46619 and a nitric oxide synthase inhibitor, N-nitro-l -arginine (NOLA), but not in the presence of angiotensin II. 3. N-Nitro-l -arginine caused vasoconstriction of the perfused placenta and indomethacin attenuated this effect and blocked the potentiation of the 5-HT response by NOLA. 4. Indomethacin did not affect ET-1-induced pressure increases and infusion of U46619 had no effect on release of ET-Iike immunoreactivity into the foetal placental circulation. 5. The present study provides evidence of interactions between several autacoids in human perfused placentae in vitro. These interactions may play important roles in foetal placental haemodynamics in normal or pathological situations.     

Induction of an anomalous blue-green wavelength discrimination by reduced viewing time

Wavelength discrimination was studied on three colour-normal human observers for open viewing and for reduced time viewing. All three observers show a loss of blue-green wavelength discrimination when viewing time is reduced to 3.75 msec. This loss is shown to be an effect of viewing time alone and not of reduced retinal illuminance. The results confirm those reported by Foster, Scase and Taylor¹ although the target size and methodology are different.