Patterns of injury and violence in Yaoundé Cameroon: an analysis of hospital data.

BackgroundInjuries are quickly becoming a leading cause of death globally, disproportionately affecting sub-Saharan Africa, where reports on the epidemiology of injuries are extremely limited. Reports on the patterns and frequency of injuries are available from Cameroon are also scarce. This study explores the patterns of trauma seen at the emergency ward of the busiest trauma center in Cameroon's capital city.Materials and methodsAdministrative records from January 1, 2007, through December 31, 2007, were retrospectively reviewed; information on age, gender, mechanism of injury, and outcome was abstracted for all trauma patients presenting to the emergency ward. Univariate analysis was performed to assess patterns of injuries in terms of mechanism, date, age, and gender. Bivariate analysis was used to explore potential relationships between demographic variables and mechanism of injury.ResultsA total of 6,234 injured people were seen at the Central Hospital of Yaoundé's emergency ward during the year 2007. Males comprised 71% of those injured, and the mean age of injured patients was 29 years (SD = 14.9). Nearly 60% of the injuries were due to road traffic accidents, 46% of which involved a pedestrian. Intentional injuries were the second most common mechanism of injury (22.5%), 55% of which involved unarmed assault. Patients injured in falls were more likely to be admitted to the hospital (p < 0.001), whereas patients suffering intentional injuries and bites were less likely to be hospitalized (p < 0.001). Males were significantly more likely to be admitted than females (p < 0.001)DiscussionPatterns in terms of age, gender, and mechanism of injury are similar to reports from other countries from the same geographic region, but the magnitude of cases reported is high for a single institution in an African city the size of Yaoundé. As the burden of disease is predicted to increase dramatically in sub-Saharan Africa, immediate efforts in prevention and treatment in Cameroon are strongly warranted

Automatic Population of Structured Reports from Narrative Pathology Reports

There are a number of advantages for the use of structured pathology reports: they can ensure the accuracy and completeness of pathology reporting; it is easier for the referring doctors to glean pertinent information from them. The goal of this thesis is to extract pertinent information from free-text pathology reports and automatically populate structured reports for cancer diseases and identify the commonalities and differences in processing principles to obtain maximum accuracy. Three pathology corpora were annotated with entities and relationships between the entities in this study, namely the melanoma corpus, the colorectal cancer corpus and the lymphoma corpus. A supervised machine-learning based-approach, utilising conditional random fields learners, was developed to recognise medical entities from the corpora. By feature engineering, the best feature configurations were attained, which boosted the F-scores significantly from 4.2% to 6.8% on the training sets. Without proper negation and uncertainty detection, the quality of the structured reports will be diminished. The negation and uncertainty detection modules were built to handle this problem. The modules obtained overall F-scores ranging from 76.6% to 91.0% on the test sets. A relation extraction system was presented to extract four relations from the lymphoma corpus. The system achieved very good performance on the training set, with 100% F-score obtained by the rule-based module and 97.2% F-score attained by the support vector machines classifier. Rule-based approaches were used to generate the structured outputs and populate them to predefined templates. The rule-based system attained over 97% F-scores on the training sets. A pipeline system was implemented with an assembly of all the components described above. It achieved promising results in the end-to-end evaluations, with 86.5%, 84.2% and 78.9% F-scores on the melanoma, colorectal cancer and lymphoma test sets respectively

Evaluating the role of neurotensin and its receptors in colorectal cancers and polyps

Importance Colorectal Cancer (CRC) accounts for 9% of cancer deaths globally. The clinical role of hormones is well established in some cancers but remains unclear in CRC. Neurotensin (NTS) and its receptors 1 and 3 (NTSR1 and NTSR3) are implicated in CRC carcinogenesis and growth. This thesis hypothesises that NTS and its receptors have the potential to be used as novel diagnostic and prognostic biomarkers for CRC. Such biomarkers could improve early detection and risk stratification of CRC. Furthermore, it could allow the personalisation of CRC treatment through novel therapeutic pathways. Objectives The up to date evidence for the role NTS plays in CRC is systematically reviewed. Two studies were then carried out to test the hypothesis. Firstly, the accuracy of plasma NTS concentration as a diagnostic biomarker for colorectal polyp and cancer is assessed. The second study characterised and quantified the protein expression of NTS, NTSR1 and NTSR3 in human CRC specimens. It then evaluated the association between NTS, NTSR1 and NTSR3 expression, histological grade of CRC and cancer survival. Design, Setting, and Participants Two separate multicentre prospective cohort studies were set up. The first study recruited 180 patients to evaluate the diagnostic accuracy of plasma NTS concentration for colorectal polyps and cancers in patients with high-risk symptoms. Plasma samples were collected from the participants who then underwent diagnostic colonoscopy or computerised tomographic virtual colonography. The plasma concentration of NTS was quantified using enzyme-linked immunoassay. The diagnostic accuracy of plasma NTS was assessed using receiver operator characteristics curve analysis. The finding of the prospective study was then validated using 100 plasma samples stored in a tissue bank. The second study recruited 64 patients with CRC who underwent surgical resection with curative intent. The protein expression of NTS, NTSR1 and NTSR3 in the cancer resection specimens and surrounding normal epithelium was visualised using immunohistochemical staining. The intensity and proportion of expression of all three markers were quantified using the hybrid scoring (H-score) system. The relationship between the expression of these proteins and histopathological, clinical, and survival outcomes was evaluated. Results In the first study, of the 180 participants, 165 were eligible. Of these, 46 had colorectal polyps or cancer. Significantly higher plasma NTS was found in patients with colorectal polyps or cancers compared to those without (603.6 pg/ml vs 407.2 pg/ml, p < 0.01). Loge (plasma NTS concentration) was a significant independent risk factor for the presence of colorectal polyps or cancers (odds ratio, 2.73; 95% CI, 1.33–5.59, p < 0.01). Plasma NTS had an optimal sensitivity of 70.8% and specificity of 59.5% for the diagnosis of colorectal polyps and cancers. Similar diagnostic accuracy was obtained in the validation group. In the second study, of the 64 patients enrolled, 58 participants’ specimen blocks were immunostained. There was significantly higher expression of NTS in CRC of higher T stages (p<0.01), N stages (p=0.03), and AJCC clinical stages (p=0.04). There was significantly higher expression of NTS in cancer tissue compared to surrounding normal epithelium (median H-score 163.5 vs 97.3, p<0.01). There was significantly shorter disease-free survival (DFS) in individuals with CRC which expressed high levels of NTS compared to low levels of NTS (32.8 months 95% CI: 26.8 – 38.8 months vs 41.0 months 95% CI: 37.7–44.4 months respectively, p=0.01). Above median NTS expression in cancer tissue was a significant risk factor for disease recurrence (hazard ratio 5.60, 95% CI 1.22 – 25.6, p=0.03, Cox proportional regression). Conclusions and Relevance Plasma NTS has the potential to be a non-invasive biomarker for colorectal neoplasia. It appears to have better accuracy than existing blood markers and is unique in being able to also detect precancerous polyps. Furthermore, high tissue expression of NTS appears to be associated with more advanced CRC and shorter DFS. NTS expression level can potentially aid postoperative selection for conventional adjuvant therapy and identify individuals for novel therapies targeting the neurotensinergic pathways. These findings support the overarching hypothesis of this work; NTS has the potential to be both a diagnostic and prognostic marker of CRC.Open Acces