骨髓显像及其在血液系统中的应用

 骨髓显像是利用骨髓中单核吞噬细胞可吞噬经静脉注射的胶体显像剂,而红骨髓中的造血细胞与单核吞噬细胞分布具有一致性,因此可间接观察红骨髓分布情况的一种显像技术。因这种技术克服了传统穿刺活检只能局部取材的缺点,提供全身有功能骨髓的影像,简单、无创,在血液系统疾病的诊治中应用广泛。     

Radiation dose assessments in radioiodine (131I) therapy. 1. The necessity for in vivo quantitation and dosimetry in the treatment of carcinoma of the thyroid

In order to destroy thyroid cancer metastases by radioiodine an average tissue dose of 80-300 Gy is needed. Such high doses can be expected, following the administration of the conventional 5.5 GBq of 131I, only if both the percentage uptake per gram in the target tissue and the effective half life of the radioiodine in it are higher than well-defined threshold values, and if every dimension of the tissue exceeds several millimeters. The fulfillment of such favourable conditions in actual clinical cases can only be confirmed by in vivo quantitation of the absorbed dose achieved as a result of the administration of radioiodine.     

Role of oncogene activation during prenatal (transplacental) initiation and postnatal promotion of mouse skin tumours

The transplacental initiation-postnatal promotion model of mouse skin carcinogenesis is useful in studying the molecular and cellular mechanisms of perinatal carcinogenesis. Offspring transplacentally exposed to an initiating dose of a carcinogen typically do not produce any skin tumours in the absence of postnatal treatment; many skin tumours appear only when they are treated with tumour-promoting agents postnatally. Tumour-promoting agents alone produce no skin tumours or only a few. Thus, two stages of carcinogenesis, initiation and promotion, can be conveniently separated. Our results indicate that fetal c-Ha-ras can be transplacentally activated through a specific point mutation by a carcinogen. However, since postnatal promotion was essential for the production of tumours, they also suggest that a cell harbouring such a mutation may remain dormant until it encounters a tumour-promoting stimulus. Since a higher fraction of carcinomas than papillomas contained the specific mutation in Ha-ras, it is postulated that those papillomas with the point mutation have a selective advantage to progress towards carcinomas.     

Commentary: Novel therapies for cancer: why dirty might be better

In the era of targeted therapy, many have argued that targeted therapies would not only be more effective but also less toxic. However, the early evidence suggests that the assumption that greater specificity would result in greater efficacy may have been premature. In fact, it can be argued that dirty may be better than clean.     

Solitary lung nodule due to dirofilaria immitis (dog “heartworm”)

The filarial parasite Dirofilaria immitis (dog “heartworm”) is the cause of a progressive zoonosis among canine species in the United States; it is rarely transmitted to man, in whom it can present as a solitary lung nodule. There are currently no reliable clinical or radiologic features to distinguish it from other solitary necrotizing granulomas, and thoracotomy is currently the only means of establishing the diagnosis. D. immitis can be identified and properly classified by routine light microscopy despite being immature and partially necrotic. Canine Dirofilariasis may well assume even greater medical importance because of its expanding geographic range and the concomitant increase in the number of cases observed among humans.     

Kosten und Nutzen der Darmkrebsprävention

Colorectal cancer prevention saves lives and furthermore it has positive economic effects. A cost-benefit analysis shows that health insurance funds can reduce their treatment expenses by means of colorectal cancer prevention and the associated preventable diseases. Additionally it is also possible to avoid a loss of production due to colorectal cancer diseases of employed persons. Thus colorectal cancer prevention is of high relevance to companies. Colonoscopy, which can be accessed at no charge by all socially insured persons aged 55 years or older, is in the focus of the following analysis. An important result of the analysis is that the monetary benefit of colorectal cancer prevention is 4–7 times higher than the associated costs. A life year gained by colonoscopy costs on average 1,380 Euros to 2,622 Euros. However colorectal cancer prevention can only be effective, if it is actually accessed by the beneficiaries. Therefore the participation rates must be enhanced to put the positive benefits for the population, for the health insurance funds and for the employers into effect.     

Molecular and pathological characterization of inherited breast cancer

The two major breast cancer susceptibility genes, BRCA1 and BRCA2, account for the majority of familial breast-ovarian cancer, but only a modest proportion of breast cancer families without ovarian or male breast cancer. Search for additional breast cancer genes with traditional linkage analysis has so far been unsuccessful, probably due to genetic heterogeneity. Pooling of families of different ethnical, cultural, and geographical origin proved to be a useful approach when identifying BRCA1 and BRCA2, but for genes mutated only in specific populations it is important not to introduce locus heterogeneity by pooling. Genetic heterogeneity can possibly be circumvented by using objective means, such as tumour histopathology or gene expression profiling, for subclassification of families prior to linkage analysis. Also, additional breast cancer genes can be identified by further characterization of the function of BRCA1 and BRCA2 and their interacting proteins.     

Therapeutic strategies for breast cancer based on histological type

Breast cancer has various histological types that reflect not only morphological features but also biological characteristics. Therefore, it is not an exaggeration to say that breast cancers of different histological types are different diseases. It is generally accepted that the histological types of breast cancer are clinically significant because they serve as prognosticators and as the common language for improving the accuracy of clinical diagnosis. It is necessary to diagnose breast cancer at the level of not only histological findings by needle biopsy, but also the histologic type based on diagnostic imaging and cytological diagnosis. From the viewpoint of treatment, preoperative drug therapy is being performed more frequently to shrink tumors before breast-conserving therapy or to determine treatment sensitivity. The prognosis is favorable for patients who respond completely or patients in whom interstitial infiltration is completely eliminated histopathologically, and, as a result, it is important to assess therapeutic efficacy clinically and pathologically. Past experience has shed some light on differentiating cancers responsive to drug therapy from those unresponsive to drug therapy, as well as differentiating cancers in which therapeutic efficacy can be easily ascertained from those in which therapeutic efficacy cannot be easily ascertained. Preoperative drug therapy can be planned by making a histological diagnosis based on needle biopsy findings. Preoperative drug therapy is not indicated for noninvasive carcinoma and papillotubular carcinoma (invasive carcinoma with predominant intraductal components). While complete loss of interstitial infiltration can be expected with solid-tubular carcinoma, it cannot be expected with other histological types, such as invasive lobular carcinoma, adenoid cystic carcinoma, or metaplastic carcinoma (squamous-cell carcinoma and spindle-cell carcinoma). On therapeutic response assessment, the clinical and pathological findings generally match for solid-tubular carcinoma but not for scirrhous carcinoma and invasive lobular carcinoma. With mucinous carcinoma, mucus accumulation can remain, even though most cancer cells disappear; as a result, assessment based on tumor diameter changes is difficult. Histological diagnosis is also significant from the viewpoint of drug sensitivity, and it is important to maintain the accuracy of histological diagnosis.     

Immobilization devices in conformal radiotherapy for non-small cell lung cancer]

When considering three-dimensional conformal radiotherapy for non-small cell lung cancer, the uncertainties about treatment can be quite significant, due to set-up errors and organ or tumor motion. These can be important causes of treatment failure. Immobilization devices have only been studied recently in a scientific manner in the domain of chest tumors, presumably because other factors such as tumor motion were felt to be more important causes of treatment uncertainties. An international survey on immobilization devices in the treatment of non-small cell lung cancer has shown that about half of the centers are using three-dimensional conformal radiotherapy, and among these, only two-thirds use immobilization devices on a routine basis. Very few use internal fiducials. Current data on set-up errors show that the average discrepancy is about 5 mm, but in some cases it can be more than 15 mm. A recent study has demonstrated that less positioning corrections during treatments were needed for the patients who were immobilized. Another work indicates that there were no differences between a T-bar immobilization device and a system using chemical foams. Other works indicate that internal motion of bronchial tumors can vary greatly, depending on their location. A number of clinical groups are looking at minimizing the consequences of internal motion, but the currently proposed techniques appear to be cumbersome. New studies will be necessary in order to improve the knowledge of daily positioning and the effect of internal motion. Until then, it is essential to take care when considering narrow margins in conformal radiotherapy of non-small cell lung cancer.     

Photodynamic therapy for cancer

The therapeutic properties of light have been known for thousands of years, but it was only in the last century that photodynamic therapy (PDT) was developed. At present, PDT is being tested in the clinic for use in oncology--to treat cancers of the head and neck, brain, lung, pancreas, intraperitoneal cavity, breast, prostate and skin. How does PDT work, and how can it be used to treat cancer and other diseases?     

氟比洛芬酯脂微球制剂在止痛领域的研究概况

氟比洛芬酯脂微球注射液(商品名凯纷)是依据药物传递系统概念研究开发的以脂质微球为药物载体,包封氟比洛芬酯的新型非类固醇制剂,是目前惟一可静脉注射的非类固醇制剂。氟比洛芬酯是氟比洛芬脂化制备的前体药物,具有亲脂性。氟比洛芬酯脂微球注射液的特点主要有以下几方面:1)靶向性,使包裹的药物在病灶部位聚集增强药效;2)控制包裹药物的释放,使药效持续时间延长;3)易于跨膜转运,促进药物的吸收,进一步缩短起效时间;4)可静脉注射,避免了口服对消化道黏膜的损伤。作用机制主要是抑制花生四烯酸级联瀑布中环氧合酶的活性,从而抑制引起疼痛和炎症反应的前列腺素的合成,起到止痛作用。静脉注射后能迅速水解为活性物质氟比洛芬,其镇痛疗效强于阿司匹林,甚至超过了镇痛新;药物半衰期为5~8h,48h内排泄85%,主要以羟化合物和结合物的形式经肾脏排泄。氟比洛芬酯脂微球注射液除可单独应用外,还可与阿片类药物合用,在不加重阿片类药物不良反应的情况下,能增强镇痛效果且无中枢抑制作用。     

鼻咽癌短距离放疗自制新型施源器的研制及应用

目的：为改善鼻咽癌原发或复发灶的局部控制。方法：新型鼻咽癌施源器完全地鼻咽腔的形状,先制成一个塑料模体,有两根管附在它的背面,紧贴鼻咽穹窿,模体腹面有一凸起可推开软腭,使其远离两根施源管。结果：新的鼻咽癌施源器操作简便,患者无痛苦。剂量分布合理,临床疗效满意。结论：新型鼻咽癌施源器的设计应用及临床效果,在提高靶区剂量改善局部控制的同时降低了正常组织放射剂量,值得进一步临床推广应用。     

Effect of surgical resection of metastatic disease on immune tolerance to cancer. How a systemic disease could be controlled by a local therapy

Surgery represents the only chance of cure for patients with colorectal liver metastases. The results of expanded indications for surgical treatment revealed that even advanced disease can be cured in a significant percentage of cases. What is the explanation for this systemic impact of a local treatment such as surgery? What is different in those patients who can be cured by resection? In this review we analyse the available evidence of the complex relationship between the growing tumour and the immune system. Special attention is directed to the role of T regulatory cells (Tregs) recruited by the tumour to construct a tolerogenic microenvironment in which to grow. Based on the published data we developed the hypothesis that surgery breaks the tumour immune tolerance status because it not only removes the tumour, but also the protective shield of T regulatory cells.     

PTV margins should not be used to compensate for uncertainties in 3D image guided intracavitary brachytherapy

The planning target volume (PTV) concept has been created within the context of external beam radiotherapy (EBRT). It would be ideal to have a similar approach in brachytherapy (BT) to compensate for uncertainties. However, the BT and EBRT dose distributions are profoundly different, and the role of a PTV concept in BT needs a distinct discussion.The EBRT PTV concept is based on expanding the dose distribution into a homogeneous plateau reaching beyond the CTV. According to basic BT physics, there are significant dose gradients around radioactive source positions, and it is impossible to create homogeneous dose plateaus. This means that PTV margins cannot be directly applied in BT. Application of PTV margins in lateral and anterior-posterior directions can even lead to a significant and overall dose escalation (∼8% per mm margin applied) for the individual patient and for the entire patient population. In the specific direction along the intrauterine tandem, safety margins can partly account for uncertainties, though.In conclusion, safety margins can only be partially applied in intracavitary BT, and it is not recommended to perform PTV delineation. The PTV seems not to be useful for dose reporting, and dose normalisation to PTV is strongly discouraged since it can lead to dose escalation.     

Probability Sampling Method for a Hidden Population Using Respondent-Driven Sampling: Simulation for Cancer Survivors

When there is no sampling frame within a certain group or the group is concerned that making its populationpublic would bring social stigma, we say the population is hidden. It is difficult to approach this kind ofpopulation survey-methodologically because the response rate is low and its members are not quite honest withtheir responses when probability sampling is used. The only alternative known to address the problems causedby previous methods such as snowball sampling is respondent-driven sampling (RDS), which was developed byHeckathorn and his colleagues. RDS is based on a Markov chain, and uses the social network information ofthe respondent. This characteristic allows for probability sampling when we survey a hidden population. Weverified through computer simulation whether RDS can be used on a hidden population of cancer survivors.According to the simulation results of this thesis, the chain-referral sampling of RDS tends to minimize as thesample gets bigger, and it becomes stabilized as the wave progresses. Therefore, it shows that the final sampleinformation can be completely independent from the initial seeds if a certain level of sample size is secured evenif the initial seeds were selected through convenient sampling. Thus, RDS can be considered as an alternativewhich can improve upon both key informant sampling and ethnographic surveys, and it needs to be utilized forvarious cases domestically as well.     

Does electric light stimulate cancer development in children?

Incidence of cancer in children has increased in recent decades, and known risk factors can account for only a small minority of cases. Gestation and early childhood are particularly vulnerable periods in human development and an important aspect of development is in circadian rhythmicity. Emerging evidence implicates the molecular circadian mechanism in a vast array of other physiologic functions including metabolism, DNA damage response and cell-cycle regulation. Electric light exposure at night can disrupt circadian rhythms and, thereby, many other physiologic processes that are under circadian control. On this basis, it is proposed that ill-timed electric light exposure to pregnant women, to neonates, infants, and small children may increase cancer risk in those children. There are practical implications and interventions that accrue from this idea should it later be confirmed to be true.     

Image diagnostics for carcinoma of the biliary tract

Although it is clear that US is the procedure which should be selected as a method of the first choice to detect carcinoma of the biliary tract, a rational selection and combination of diagnostic procedures are essential for further evaluation on the nature or extension of tumor and its resectability. The next procedure which should be selected after US, in our opinion, is ERCP which can be followed by ERBD, if necessary, because it is useful to know the site and extension of tumor. However, the cases who have the lesion at the upper portion of the biliary tract or which is considered to be unresectable should be converted to percutaneous transhepatic approaches (PTC, PTBD, PTCS) at this stage as a method of next choice with diagnostic and subsequent therapeutic purposes. On the other hand, EUS is also an important first line diagnostic procedure to delineate the lesion at the lower portion of the biliary tract which can be used in parallel with ERCP. In this paper, usefulness of EUS was strongly advocated, because the information concerning the extension and resectability of tumor are also provided with it as it is obtained with CT, MRT and angiography. Cytology of bile, cholecystography, percutaneous transhepatic cholangioscopy and biopsy under endoscopic control carried out after percutaneous transhepatic drainage of the gallbladder are the procedures used for the diagnosis of gallbladder carcinoma, but they should be only indicated in the cases, in which early carcinoma is strongly suspected, because it cannot provide us any information necessary to make therapeutic plan in the cases with advanced carcinoma.     

Risk creation,loss of chance,and legal liability

One can now only speculate as to the future of the law regarding risk creation and loss of chance. Freed from the moorings of the traditional rules in medical malpractice cases, courts are adopting a variety of approaches to this problem in a manner that approaches the idiosyncratic--the law is whatever it happens to be on any given day, in any given jurisdiction. Regrettably, until such time as uniform guiding principles are established, it appears that the laws governing the interaction between risk, causation, and liability will remain in a state of flux.     

A slim 198gold-grain implanter loaded with standard Royal Marsden 14-grain magazines.

We designed a slim gold-grain implanter with adaptable lengths to implant areas accessible only through long, narrow, examining instruments, such as a suspension laryngoscope. The implanter is loaded with the same 14-grain magazine designed for and supplied with the Royal Marsden "gun." The simplicity of the loading mechanism with a minimum of moving parts makes the instrument practically trouble free. Although it is designed to be used along narrow examining instruments, it can also be used in any situation in which a permanent implant is required, for instance, prostatic cancer and pelvic recurrences in cancer of the uterine cervix previously treated by external and intracavitary irradiation.     

Principles in mass screening for breast cancer

The only proven means to reduce mortality from breast cancer is detection of the disease when it is still localized to the breast. Such a cancer is usually without signs or symptoms and often not even palpable and can be detected only through mass screening. The H.I.P. study has demonstrated a 30% reduction in mortality in a randomized study group compared to a matched control. The reduction has persisted over 14 years of follow up. Questions of potential hazard from x-ray radiation, questionable significant benefit in women under 50 years, cost and motivation are discussed.