Symptom appraisal and healthcare-seeking for symptoms suggestive of colorectal cancer: a qualitative study

OBJECTIVES

Timely diagnosis of colorectal cancer is important to improve survival. This study explored symptom appraisal and help-seeking among patients referred to specialist services with symptoms of colorectal cancer.

DESIGN

Qualitative in-depth interview study.

SETTING AND PARTICIPANTS

Participants were recruited on referral to gastroenterology clinics (North East and East of England); interviews were conducted soon after referral. We purposively sampled participants to ensure a range of accounts in terms of age, sex, diagnosis and geographical location.

METHODS

Data collection and analysis were underpinned by the Model of Pathways to Treatment. Framework analysis was used to explore the data within and across cases, focusing on patient beliefs and experiences, disease factors and healthcare influences.

RESULTS

40 participants were interviewed (aged 43-87 years, 17 women, 18 diagnosed with colorectal cancer). Patients diagnosed with and without colorectal cancer had similar symptom pathways. We found a range of interacting and often competing biopsychosocial, contextual and cultural influences on the way in which people recognised, interpreted and acted on their symptoms. People attempted to 'maintain normality' through finding benign explanations for their symptoms. Bodily changes were appraised within the context of usual bowel patterns, comorbidities and life events, and decisions to seek help were made in relation to expectations about the course of symptoms. The 'private nature' of colorectal cancer symptoms could affect both their identification and discussions with others including healthcare professionals. Within the context of the National Health Service, people needed to legitimise appropriate use of healthcare services and avoid being thought of as wasting doctors' time.

CONCLUSIONS

Findings provide guidance for awareness campaigns on reducing stigma around appraising and discussing bowel movements, and the importance of intermittent and non-specific symptoms. Altering perceptions about the appropriate use of health services could have a beneficial effect on time to presentation.

Symptoms and other factors associated with time to diagnosis and stage of lung cancer: a prospective cohort study

BACKGROUND

This prospective cohort study aimed to identify symptom and patient factors that influence time to lung cancer diagnosis and stage at diagnosis.

METHODS

Data relating to symptoms were collected from patients upon referral with symptoms suspicious of lung cancer in two English regions; we also examined primary care and hospital records for diagnostic routes and diagnoses. Descriptive and regression analyses were used to investigate associations between symptoms and patient factors with diagnostic intervals and stage.

RESULTS

Among 963 participants, 15.9% were diagnosed with primary lung cancer, 5.9% with other thoracic malignancies and 78.2% with non-malignant conditions. Only half the cohort had an isolated first symptom (475, 49.3%); synchronous first symptoms were common. Haemoptysis, reported by 21.6% of cases, was the only initial symptom associated with cancer. Diagnostic intervals were shorter for cancer than non-cancer diagnoses (91 vs 124 days, P=0.037) and for late-stage than early-stage cancer (106 vs 168 days, P=0.02). Chest/shoulder pain was the only first symptom with a shorter diagnostic interval for cancer compared with non-cancer diagnoses (P=0.003).

CONCLUSIONS

Haemoptysis is the strongest symptom predictor of lung cancer but occurs in only a fifth of patients. Programmes for expediting earlier diagnosis need to focus on multiple symptoms and their evolution.

Phylogenomics of the killer whale indicates ecotype divergence in sympatry

For many highly mobile species, the marine environment presents few obvious barriers to gene flow. Even so, there is considerable diversity within and among species, referred to by some as the 'marine speciation paradox'. The recent and diverse radiation of delphinid cetaceans (dolphins) represents a good example of this. Delphinids are capable of extensive dispersion and yet many show fine-scale genetic differentiation among populations. Proposed mechanisms include the division and isolation of populations based on habitat dependence and resource specializations, and habitat release or changing dispersal corridors during glacial cycles. Here we use a phylogenomic approach to investigate the origin of differentiated sympatric populations of killer whales (Orcinus orca). Killer whales show strong specialization on prey choice in populations of stable matrifocal social groups (ecotypes), associated with genetic and phenotypic differentiation. Our data suggest evolution in sympatry among populations of resource specialists.

Host-Parasite interactions in Entamoeba histolytica and Entamoeba dispar: what have we learned from their genomes?

Invasive amoebiasis caused by Entamoeba histolytica is a major global health problem. Virulence is a rare outcome of infection, occurring in fewer than 1 in 10 infections. Not all strains of the parasite are equally virulent, and understanding the mechanisms and causes of virulence is an important goal of Entamoeba research. The sequencing of the genome of E. histolytica and the related avirulent species Entamoeba dispar has allowed whole-genome-scale analyses of genetic divergence and differential gene expression to be undertaken. These studies have helped elucidate mechanisms of virulence and identified genes differentially expressed in virulent and avirulent parasites. Here, we review the current status of the E. histolytica and E. dispar genomes and the findings of a number of genome-scale studies comparing parasites of different virulence.

Optimization of a real-time RT-PCR assay reveals an increase of genogroup I norovirus in the clinical setting

Although norovirus has been identified as the most common cause of gastroenteritis, the majority of cases have no etiologic agent identified. In this study, we describe the optimization of a real-time RT-PCR assay for the improved detection of genogroup I norovirus in patient specimens based upon sequence data from a collection of representative clinical norovirus sequences. The redesigned assay demonstrated a 64 fold increase in sensitivity, a 2 log decrease in the limit of detection, and an 18% increase in amplification efficiency, when compared to the standard assay. The optimized test also detected GI norovirus in clinical specimens that were initially negative by the standard assay. Use of the optimized assay increased the annual positivity of GI norovirus in Iowa from 1.2% to 4.5%, indicating the prevalence of GI norovirus may be higher than previously identified. Laboratory confirmation of the etiologic agent involved in gasteroenteritis cases is essential for better understanding of the prevalence and transmission of noroviruses.

The association of visuospatial working memory with dysthymic disorder in pre-pubertal children

BACKGROUND

Visuospatial working memory (VSWM) deficits have not been investigated specifically in children with dysthymic disorder (DD), although they are associated with impairments in attention that commonly occur in DD. This study investigates VSWM impairment in children with DD.

METHOD

A cross-sectional study of VSWM in 6- to 12-year-old children with medication-naive DD (n=26) compared to an age-, gender- and 'performance IQ' (PIQ)-matched healthy control group (n=28) was completed.

RESULTS

The DD group demonstrated impairment in VSWM, including impairment in the spatial span and strategy components of VSWM. Furthermore, the VSWM impairment remained after controlling for spatial span. Inattentive symptoms were significantly associated with the VSWM impairment.

CONCLUSIONS

This study of children with DD found deficits in performance on VSWM tasks, suggesting that fronto-striatal-parietal neural networks that underlie processes of attention and the executive component of VSWM are dysfunctional in children with DD. These findings further our understanding of DD and suggest more specific interventions that might improve functioning.

A deformation-based morphometry study of patients with early-stage Parkinson's disease

BACKGROUND AND PURPOSE

Previous volumetric magnetic resonance imaging (MRI) studies of Parkinson's disease (PD) utilized primarily voxel-based morphometry (VBM), and investigated mostly patients with moderate- to late-stage disease. We now use deformation-based morphometry (DBM), a method purported to be more sensitive than VBM, to test for atrophy in patients with early-stage PD.

METHODS

T1-weighted MRI images from 24 early-stage PD patients and 26 age-matched normal control subjects were compared using DBM. Two separate studies were conducted, where two minimally-biased nonlinear intensity-average were created; one for all subjects and another for just the PD patients. The DBM technique creates an average population-based MRI-average in an iterative hierarchical fashion. The nonlinear transformations estimated to match each subject to the MRI-average were then analysed.

RESULTS

The DBM comparison between patients and controls revealed significant contraction in the left cerebellum, and non-significant trends towards frontal, temporal and cingulate sulcal expansions with frontal and temporal white matter contractions. Within the patient group, the unified PD rating scores were highly correlated with local expansions in or near sulci bordering on frontal and temporal cortex.

CONCLUSION

Our results suggest that DBM could be a sensitive method for detecting morphological changes in early-stage PD.

A low-noise differential microphone inspired by the ears of the parasitoid fly Ormia ochracea

A miniature differential microphone is described having a low-noise floor. The sensitivity of a differential microphone suffers as the distance between the two pressure sensing locations decreases, resulting in an increase in the input sound pressure-referred noise floor. In the microphone described here, both the diaphragm thermal noise and the electronic noise are minimized by a combination of novel diaphragm design and the use of low-noise optical sensing that has been integrated into the microphone package. The differential microphone diaphragm measures 1 x 2 mm(2) and is fabricated out of polycrystalline silicon. The diaphragm design is based on the coupled directionally sensitive ears of the fly Ormia ochracea. The sound pressure input-referred noise floor of this miniature differential microphone has been measured to be less than 36 dBA.

The relationship between adiponectin, progesterone, and temperature across the menstrual cycle

BACKGROUND

The mechanisms regulating adiponectin, a highly abundant adipokine produced by adipocytes, have not been fully elucidated. Adiponectin levels are significantly higher in women when compared to men, suggesting sex-hormone involvement in its regulation. Previously, we have observed an inverse association between adiponectin and basal body temperature in pregnant women. These findings suggest that states where progesterone and temperature fluctuate, such as the menstrual cycle, could be associated with fluctuating adiponectin levels.

AIM

The aim of this study was to examine the relationship between adiponectin, progesterone, and temperature across the menstrual cycle.

SUBJECTS AND METHODS

A prospective study was performed. Fifteen non-obese pre-menopausal female subjects, all with regular cycles, and on no medication recorded a daily temperature and underwent blood sampling, indirect calorimetry, and bio-impendence studies in both the follicular and luteal phases of the menstrual cycle.

RESULTS

Serum adiponectin levels did not vary significantly across the menstrual cycle or between those who did and did not ovulate. No correlation was found between adiponectin levels and sex steroids, insulin and glucose levels or basal energy expenditure and body composition.

CONCLUSIONS

Our results indicate that adiponectin is not related to sex steroids or body composition in healthy premenstrual women.

The genome of the simian and human malaria parasite Plasmodium knowlesi

Plasmodium knowlesi is an intracellular malaria parasite whose natural vertebrate host is Macaca fascicularis (the 'kra' monkey); however, it is now increasingly recognized as a significant cause of human malaria, particularly in southeast Asia. Plasmodium knowlesi was the first malaria parasite species in which antigenic variation was demonstrated, and it has a close phylogenetic relationship to Plasmodium vivax, the second most important species of human malaria parasite (reviewed in ref. 4). Despite their relatedness, there are important phenotypic differences between them, such as host blood cell preference, absence of a dormant liver stage or 'hypnozoite' in P. knowlesi, and length of the asexual cycle (reviewed in ref. 4). Here we present an analysis of the P. knowlesi (H strain, Pk1(A+) clone) nuclear genome sequence. This is the first monkey malaria parasite genome to be described, and it provides an opportunity for comparison with the recently completed P. vivax genome and other sequenced Plasmodium genomes. In contrast to other Plasmodium genomes, putative variant antigen families are dispersed throughout the genome and are associated with intrachromosomal telomere repeats. One of these families, the KIRs, contains sequences that collectively match over one-half of the host CD99 extracellular domain, which may represent an unusual form of molecular mimicry.

Array comparative genomic hybridization in global developmental delay

OBJECTIVE

Array-based comparative genomic hybridization (array CGH) is an emerging technology that allows for the genome-wide detection of DNA copy number changes (CNC) such as deletions or duplications. In this study, array-based CGH was applied to a consecutive series of children with previously undiagnosed non-syndromal global developmental delay (GDD) to assess potential etiologic yield.

METHODS

The children in this study were drawn from a previously reported consecutive series of children with well-defined GDD. Almost all subjects had undergone prior karyotyping and neuroimaging studies with non-diagnostic results. Array-based CGH was undertaken using the SignatureChip(R) (1887 BACs representing 622 loci) with abnormalities verified by subsequent FISH analysis and testing of parents to distinguish between pathogenic and familial non-pathogenic variants.

RESULTS

On CGH analysis in our study, 6 of 94 children (6.4%) had a causally related pathogenic CNC. Three were sub-telomeric in location. An analysis of a variety of clinical factors revealed that only the presence of minor dysmorphic features (<3) was predictive of etiologic yield on CGH analysis (4/26 vs. 2/68, P = 0.05). Severity of delay was not found to be predictive.

INTERPRETATION

In children with non-syndromal GDD, array-based CGH has an etiologic yield of 6.4%. This suggests that this emerging technology may be of diagnostic value when applied subsequent to detailed history, physical examination, and targeted laboratory testing. Array CGH may merit consideration as a first-tier test in the context of a child with unexplained GDD.