The value of age and medical history for predicting colorectal cancer and adenomas in people referred for colonoscopy

<p>Abstract</p> <p>Background</p> <p>Colonoscopy is an invasive and costly procedure with a risk of serious complications. It would therefore be useful to prioritise colonoscopies by identifying people at higher risk of either cancer or premalignant adenomas. The aim of this study is to assess a model that identifies people with colorectal cancer, advanced, large and small adenomas.</p> <p>Methods</p> <p>Patients seen by gastroenterologists and colorectal surgeons between April 2004 and December 2006 completed a validated, structured self-administered questionnaire prior to colonoscopy. Information was collected on symptoms, demographics and medical history. Multinomial logistic regression was used to simultaneously assess factors associated with findings on colonoscopy of cancer, advanced adenomas and adenomas sized 6 -9 mm, and ≤ 5 mm. The area under the curve of ROC curve was used to assess the incremental gain of adding demographic variables, medical history and symptoms (in that order) to a base model that included only age.</p> <p>Results</p> <p>Sociodemographic variables, medical history and symptoms (from 8,204 patients) jointly provide good discrimination between colorectal cancer and no abnormality (AUC 0.83), but discriminate less well between adenomas and no abnormality (AUC advanced adenoma 0.70; other adenomas 0.67). Age is the dominant risk factor for cancer and adenomas of all sizes. Having a colonoscopy within the last 10 years confers protection for cancers and advanced adenomas.</p> <p>Conclusions</p> <p>Our models provide guidance about which factors can assist in identifying people at higher risk of disease using easily elicited information. This would allow colonoscopy to be prioritised for those for whom it would be of most benefit.</p

Always a price to pay: hibernation at low temperatures comes with a trade-off between energy savings and telomere damage

We experimentally tested the costs of deep torpor at low temperatures by comparing telomere dynamics in two species of rodents hibernating at either 3 or 14°C. Our data show that hibernators kept at the warmer temperature had higher arousal frequencies, but maintained longer telomeres than individuals hibernating at the colder temperature. We suggest that the high-energy demand of frequent arousals is counteracted by a lower temperature differential between torpid and euthermic body temperature and that telomere length is restored during arousals when the body temperature is returned to normothermic values. Taken together, our study shows that hibernation at low body temperatures comes with costs on a cellular level and that hibernators need to actively counterbalance the shortening of telomeres

Therapeutic Radionuclides: Making the Right Choice

Recently, there has been a resurgence of interest in nuclear medicine therapeutic procedures. Using unsealed sources for therapy is not a new concept; it has been around since the beginnings of nuclear medicine. Treatment of thyroid disorders with radioiodine is a classic example. The availability of radionuclides with suitable therapeutic properties for specific applications, as well as methods for their selective targeting to diseased tissue have, however, remained the main obstacles for therapy to assume a more widespread role in nuclear medicine. Nonetheless, a number of new techniques that have recently emerged, (e.g., tumor therapy with radiolabeled monoclonal antibodies, treatment of metastatic bone pain, etc.) appear to have provided a substantial impetus to research on production of new therapeutic radionuclides. Although there are a number of new therapeutic approaches requiring specific radionuclides, only selected broad areas will be used as examples in this article

A systematic review of the incidence of schizophrenia: the distribution of rates and the influence of sex, urbanicity, migrant status and methodology

BACKGROUND: Understanding variations in the incidence of schizophrenia is a crucial step in unravelling the aetiology of this group of disorders. The aims of this review are to systematically identify studies related to the incidence of schizophrenia, to describe the key features of these studies, and to explore the distribution of rates derived from these studies. METHODS: Studies with original data related to the incidence of schizophrenia (published 1965–2001) were identified via searching electronic databases, reviewing citations and writing to authors. These studies were divided into core studies, migrant studies, cohort studies and studies based on Other Special Groups. Between- and within-study filters were applied in order to identify discrete rates. Cumulative plots of these rates were made and these distributions were compared when the underlying rates were sorted according to sex, urbanicity, migrant status and various methodological features. RESULTS: We identified 100 core studies, 24 migrant studies, 23 cohort studies and 14 studies based on Other Special Groups. These studies, which were drawn from 33 countries, generated a total of 1,458 rates. Based on discrete core data for persons (55 studies and 170 rates), the distribution of rates was asymmetric and had a median value (10%–90% quantile) of 15.2 (7.7–43.0) per 100,000. The distribution of rates was significantly higher in males compared to females; the male/female rate ratio median (10%–90% quantile) was 1.40 (0.9–2.4). Those studies conducted in urban versus mixed urban-rural catchment areas generated significantly higher rate distributions. The distribution of rates in migrants was significantly higher compared to native-born; the migrant/native-born rate ratio median (10%–90% quantile) was 4.6 (1.0–12.8). Apart from the finding that older studies reported higher rates, other study features were not associated with significantly different rate distributions (e.g. overall quality, methods related to case finding, diagnostic confirmation and criteria, the use of age-standardization and age range). CONCLUSIONS: There is a wealth of data available on the incidence of schizophrenia. The width and skew of the rate distribution, and the significant impact of sex, urbanicity and migrant status on these distributions, indicate substantial variations in the incidence of schizophrenia

Tumor uptake and mitotic activity pattern of 5-[I-125]iodo-2'-deoxyuridine after intravesical infusion in patients with bladder cancer

In patients with bladder cancer, little is known about diffusion in the tumor mass of 5-iodo-2'-deoxyuridine (IUdR) administered intraluminally, although previous studies based on external scanning have shown promising tumor-targeting properties of IUdR instilled intravesically, This study compared the pattern of IUdR uptake by bladder cancer cells with the actual distribution of mitotic activity, as evaluated by incubation of ex vivo tumor specimens with tritiated thymidine, Methods: The [I-125]IUdR (2-13 MBq) was instilled over 1-3 hr in the bladder of four patients with bladder cancer scheduled for ablative surgery. Twenty-four hours later, surgical samples were assayed for radioactivity and processed for microautoradiography, while fresh tumor specimens were fragmented, incubated with [H-3]thymidine and further processed for microautoradiography. The diffusion of labeled IUdR across the bladder wall was evaluated by blood sampling, Results: Tumor incorporation of [(125)]]IUdR 24 hr after intravesical instillation was 0.002%-0.05% ID/g, while the average tumor-to-normal bladder ratio was about 20, Microautoradiography showed that [I-125]IUdR incorporation was confined to tumor cells in the most superficial layers of the bladder, while incubation of the tumor fragments with [H-3]thymidine demonstrated the presence of diffuse mitotic activity also in the deeper tumor mass. Diffusion of labeled IUdR in the general circulation was minimal. Conclusion: Poor diffusion in the tumor mass makes *IUdR unsuitable for intracavitary therapy of bladder cancer, but the role of such an approach in the postsurgical ''sterilization'' of cancer remnants floating in the bladder lumen after partial cystectomy should be explored