Not all cancer cells are born equal. While the great majority of the cells that make up tumours are destined to differentiate, albeit aberrantly, and eventually stop dividing, a handful of cancer cells appear to possess limitless replicative potential. This review presents compelling evidence to suggest that the bulk of malignant cells of most cancers are generated by a rare fraction of stem cell-like cancer cells. These cells, dubbed cancer stem cells, are phenotypically similar to the normal stem cells of the corresponding tissue of origin, but they exhibit dysfunctional patterns of self-renewal and differentiation. Cancer stem cells that are capable of recapitulating brain tumours as xenografts in mice are characterised by defined stem cell markers. These brain tumour stem cells demonstrate enhanced chemoresistance and radioresistance mechanisms compared to non-stem cells in the heterogeneous tumour, which suggest that they may be the likely candidates for tumour progression and recurrence. Indeed, recent work has shown that such aberrant signalling pathways may be targeted in novel anti-cancer therapeutic strategies. The stem cell concept of tumour progression prompts immediate attention to a new paradigm in cancer research with a focus on this minority subset of cells, and the design of novel therapeutic strategies to target these cells that are insignificant within the population of tumour cells, but that are in fact the relevant cells to be destroyed.
Cell Transformation, Neoplastic ; Glioma ; pathology ; radiotherapy ; Humans ; Models, Biological ; Neoplastic Stem Cells ; drug effects ; pathology ; Singapore

INTRODUCTIONPeutz-Jeghers Syndrome (PJS) is an uncommon autosomal dominant hamartomatous polyposis syndrome. Morbidity arises from polyp-related complications and increased risks of malignancy. We report on PJS patients registered in the Singapore Polyposis Registry, identified principal causes of morbidity and appraised current management strategies. A followup protocol based on recent literature has been proposed.

MATERIALS AND METHODSA search of a prospectively collected database in the Singapore Polyposis Registry was made. Only patients who fulfilled the diagnostic criteria of PJS were included. The clinical records were retrieved for review. Information on affected family members was obtained from the Registry's pedigree records.

RESULTSSeven unrelated patients fulfilled the criteria of having PJS. Principal causes of morbidity include recurrent bouts of abdominal colic, episodes of intestinal obstruction, gastrointestinal bleeding and the need for repeated laparotomies. Six out of 7 patients had initial presentation with acute intestinal obstruction requiring emergency laparotomy. Management was mostly problem-oriented and marked inter-surgeon variation with regard to cancer screening and genetic counselling was observed.

CONCLUSIONPatients with PJS suffer gastrointestinal complications from polyposis and are at increased risks for developing cancers. A move towards surveillance and planned comprehensive care may reduce the morbidity of the condition. A protocol driven approach conducted in the setting of a Polyposis Registry is ideally suited to facilitate such care.

Adolescent ; Adult ; Child ; Cohort Studies ; Critical Pathways ; Disease Management ; Female ; Gastrointestinal Diseases ; complications ; epidemiology ; Humans ; Male ; Peutz-Jeghers Syndrome ; complications ; therapy ; Population Surveillance ; Prevalence ; Registries ; Singapore ; epidemiology ; Young Adult

INTRODUCTIONThe Singapore Polyposis Registry (SPR) was established in 1989 in Singapore General Hospital (SGH). The aims were to provide a central registry service to facilitate identification, surveillance and management of families and individuals at high risk of colorectal cancer.

MATERIALS AND METHODSThis is a review of published literature in the department.

RESULTSThe registry currently has 253 families with several genetic conditions-93 familial adenomatous polyposis (FAP) families, 138 Amsterdam-criteria positive presumed Lynch syndrome (LS) families, 12 families with Peutz Jeghers syndrome, 2 families with Cowden's syndrome, and 8 families with hereditary mixed polyposis syndrome (HMPS). There are also 169 families with a strong family history of colorectal cancer but no abnormal genes yet identified. In FAP, a diagnostic tool developed has allowed a 94% local APC germline detection rate in FAP families. Knowledge obtained studying the phenotype of FAP patients has allowed better choice of surgery between ileal pouch anal anastomosis (IPAA) against an ileal-rectal anastomosis (IRA). In LS, our review has noted a highly heterogenous mutational spectrum and novel variants made up 46.7% (28/60) of all variants identified in this cohort. This may suggest that our Southeast Asian ethnic groups have distinct mutational variants from Western populations. Pathogenic mutations were only confined to MLH1 and MSH2, and identified in 28.8% of families.

CONCLUSIONThe impact of predictive gene testing for hereditary cancer risk in clinical practice has allowed evolution of care. Risk-reducing surgery and aggressive surveillance allows reduction in morbidity and mortality of patients. The SPR will continue to grow and improve outcomes in hereditary colorectal cancer patients and families.

Adaptor Proteins, Signal Transducing ; genetics ; Colorectal Neoplasms ; diagnosis ; ethnology ; genetics ; surgery ; Disease Management ; Female ; Genetic Testing ; methods ; Humans ; Male ; MutL Protein Homolog 1 ; MutS Homolog 2 Protein ; genetics ; Mutation ; Neoplastic Syndromes, Hereditary ; classification ; diagnosis ; ethnology ; genetics ; surgery ; Nuclear Proteins ; genetics ; Registries ; statistics & numerical data ; Singapore ; epidemiology

Objective: Moderate and severe behavioral and psychological symptoms of dementia (BPSD) often need medical treatment to improve symptoms. Agomelatine is a selective melatonergic (MT1/MT2) agonist that has normalizing effects on disturbed circadian rhythms and disrupted sleep−wake cycles. Its activity of 5HT-2C receptor antagonism is associated with lessening depression and anxiety and increasing slow-wave sleep. Based on past clinical records and current findings it suggests that agomelatine can improve BPSD for patients. This retrospective cohort study was designed to compare the BPSD before and after using agomelatine. Methods: Records of dementia cases who had ever received agomelatine treatment for BPSD in a general hospital setting during the past 2.5 years were identified and reviewed. Scores from before and after 3 months of treatment with agomelatine were collected for Neuropsychiatric Inventory (NPI), Brief Psychiatric Rating Scale (BPRS), and Clinical Global Impression (CGI) to compare and analyze the difference of psychological and behavioral symptoms pre- and post-agomelatine used. Results: Records of 144 cases of dementia with BPSD who had ever used agomelatine from January 2015 to June 2017 were collected. All of the 112 cases had BPRS and CGI scores, of which 75 cases had additional NPI scores. Among these 112 cases, the BPRS and CGI scores were significantly improved in all types of dementia. NPI scores indicated that the use of agomelatine alleviated obvious symptoms and decreased overall distress, especially in the depression/poor mood, anxiety, and sleepight behavior. Conclusion It is consistent with an effective result of agomelatine in improving BPSD.

INTRODUCTION: Detection of neurological conditions is of high importance in the current context of increasingly ageing populations. Imaging of the retina and the optic nerve head represents a unique opportunity to detect brain diseases, but requires specific human expertise. We review the current outcomes of artificial intelligence (AI) methods applied to retinal imaging for the detection of neurological and neuro-ophthalmic conditions. METHOD: Current and emerging concepts related to the detection of neurological conditions, using AI-based investigations of the retina in patients with brain disease were examined and summarised. RESULTS: Papilloedema due to intracranial hypertension can be accurately identified with deep learning on standard retinal imaging at a human expert level. Emerging studies suggest that patients with Alzheimer's disease can be discriminated from cognitively normal individuals, using AI applied to retinal images. CONCLUSION Recent AI-based systems dedicated to scalable retinal imaging have opened new perspectives for the detection of brain conditions directly or indirectly affecting retinal structures. However, further validation and implementation studies are required to better understand their potential value in clinical practice.
Humans ; Artificial Intelligence ; Brain/diagnostic imaging* ; Retina ; Optic Disk ; Aging

BACKGROUNDMorphological changes of the vasculature system in patients with myopia have been observed by Doppler ultrasound and fundus fluorescein angiography (FFA); however, these studies have limitations. Doppler ultrasound provides low-resolution images which are mainly obtained from visualized large vessels, and FFA is an invasive examination. Optic coherence tomography (OCT) angiography is a noninvasive, high-resolution measurement for vascular density. The purpose of this study was to investigate the change of vascular density in myopic eyes using OCT angiography.

METHODSThis cross-sectional study includes a total of 91 eyes from 47 participants including control, moderate, and high myopia that were evaluated by OCT angiography. Patients with myopia were recruited from the Refractive Department, Shenzhen Aier Eye Hospital, from August 5, 2015 to April 1, 2016. Emmetropic eyes were from healthy volunteers. The vascular density at macula and optic disc regions, ganglion cell complex (GCC) thickness, and retinal nerve fiber layer (RNFL) thickness were measured. Their relationships with axial length (AL) and refractive error were analyzed. One-way analysis of variance (ANOVA), Pearson's correlation, and generalized estimating equation were used for statistical analysis.

RESULTSBoth superficial and deep macular vascular density were highest in control (25.64% ± 3.76% and 37.12% ± 3.66%, respectively), then in moderate myopia (21.15% ± 5.33% and 35.35% ± 5.50%, respectively), and lowest in high myopia group (19.64% ± 3.87% and 32.81% ± 6.29%, respectively) (F = 13.74 and 4.57, respectively; both P < 0.001). Both superficial (β = -0.850 and 0.460, respectively) and deep (β = -0.766 and 0.396, respectively) macular vascular density were associated with AL and spherical equivalent (all P < 0.001). Superficial macular vascular density was associated with GCC thickness (β = 0.244, P = 0.040), independent of spherical equivalent. The vascular density in optic disc region had no difference among the three groups, and it was not associated with AL, spherical equivalent, or RNFL thickness.

CONCLUSIONOur results suggested that with the increase of myopia, the vascular density decreased in macular region, but not in optic disc region.

Adult ; Cross-Sectional Studies ; Eye ; blood supply ; Female ; Fluorescein Angiography ; Humans ; Macula Lutea ; pathology ; physiopathology ; Male ; Middle Aged ; Myopia ; pathology ; physiopathology ; Optic Disk ; pathology ; physiopathology ; Prospective Studies ; Retina ; pathology ; physiopathology ; Retinal Ganglion Cells ; pathology ; Tomography, Optical Coherence ; Young Adult