Proximal fluid proteome profiling of mouse colon tumors reveals biomarkers for early diagnosis of human colorectal cancer

PURPOSE

Early detection of colorectal cancer (CRC) and its precursor lesions is an effective approach to reduce CRC mortality rates. This study aimed to identify novel protein biomarkers for the early diagnosis of CRC.

EXPERIMENTAL DESIGN

Proximal fluids are a rich source of candidate biomarkers as they contain high concentrations of tissue-derived proteins. The FabplCre;Apc(15lox/+) mouse model represents early-stage development of human sporadic CRC. Proximal fluids were collected from normal colon and colon tumors and subjected to in-depth proteome profiling by tandem mass spectrometry. Carcinoembryonic antigen (CEA) and CHI3L1 human serum protein levels were determined by ELISA.

RESULTS

Of the 2,172 proteins identified, quantitative comparison revealed 192 proteins that were significantly (P < 0.05) and abundantly (>5-fold) more excreted by tumors than by controls. Further selection for biomarkers with highest specificity and sensitivity yielded 52 candidates, including S100A9, MCM4, and four other proteins that have been proposed as candidate biomarkers for human CRC screening or surveillance, supporting the validity of our approach. For CHI3L1, we verified that protein levels were significantly increased in sera from patients with adenomas and advanced adenomas compared with control individuals, in contrast to the CRC biomarker CEA.

CONCLUSION

These data show that proximal fluid proteome profiling with a mouse tumor model is a powerful approach to identify candidate biomarkers for early diagnosis of human cancer, exemplified by increased CHI3L1 protein levels in sera from patients with CRC precursor lesions.

Fifty years of thoracic surgical research in South Africa

AIM

To investigate the scope and trends in clinical research in South African thoracic surgery between 1955 and 2006 and to measure its impact on clinical practice.

METHOD

A systematic review of all SA thoracic surgical publications was performed.

RESULTS

There were 252 general thoracic publications and a marked decrease in publications was noted after the peak period of productivity of the 1980s. There was a shift toward the private sector as an origin of articles and toward a local, non-indexed journal. Inflammatory lung disease was the most frequent topic of publication. Case series and case reports were the most frequent type of article.

CONCLUSION

The vulnerability of a small specialty in a developing country is illustrated by the clear trends that emerged. The study provides important indicators for future research, highlights the need for a national database of clinical experience, and emphasises the importance of rekindling interest and a culture of research in thoracic surgery.

Incidence of social phobia and identification of its risk indicators: a model for prevention

OBJECTIVE

This study seeks to examine the incidence of social phobia in the general population and to establish a number of risk indicators.

METHOD

Data were derived from the Netherlands Mental Health Survey and Incidence Study (NEMESIS) which is a population based prospective study (n=7076). A sample of adults aged 18-64 years (n=5618) were re-interviewed 1 year later using Composite International Diagnostic Interview (CIDI).

RESULTS

The 12-month incidence of DSM-III-R social phobia was 1.0%. Low education, low mastery, low self-esteem, emotional neglect in childhood and ongoing difficulties were found to be risk indicators. After including other mental disorders as risk indicators in the model, the incidence was found to be more common among those with low mastery, major depression, subthreshold social phobia, emotional neglect, negative life events, and low education.

CONCLUSION

The incidence of social phobia can be predicted relatively well with psychosocial variables and comorbidity.

On-line and Off-line Strategies for Preventing Depression

Depression is associated with a formidable disease burden and has substantial economic ramifications. Its burden can only be partially alleviated through treatment. To make a more substantial impact on population health, we need primary prevention to reduce the number of new cases, and we need to do a better job about preventing relapses and recurrences. In this symposium we will present the latest evidence that prevention is a viable option: it is effective and cost-effective when offered as CBT-based self-help (bibliotherapy), and as preventive cognitive therapy for relapses and recurrences. The last couple of years witnessed a new approach to improving population health when some of these preventive interventions became available as internet-based interventions. These on-line interventions can be well structured and conducted either as pure self-help or with support by a therapist. We assume that on-line interventions are acceptable, because people can access these interventions in the privacy of their homes, at times they find convenient, and at a pace that suits them best. We also expect that these interventions can be cost-effective, especially when offered as self-help. Finally, we expect that on-line interventions have great potential to reach many people. It is therefore interesting to outline some of these new strategies and present evidence of their (cost) effectiveness.

[Subclinical depression: a clinically relevant condition?]

BACKGROUND

Subclinical depression is a condition in which a person has depressive symptoms but does not meet the criteria for a depressive disorder.

AIM

To give insight in the clinical relevance of subclinical depression. method A review of a series of studies that the authors co-authored on the subject of subclinical depression. results These studies showed that subthreshold depression has serious consequences for the quality of life, but not as serious as in the case of a depressive disorder. It was also found that subthreshold (minor) depression can have considerable economic consequences for the individual concerned, although again less severe than if the individual had a depressive disorder. Because minor depression was more prevalent, the total costs of minor depression in the Netherlands (EUR 1.5 billion per year) appeared to be comparable to those of major depression (EUR 1.8 billion). It was also clear that subjects with subthreshold depression have an increased risk of developing a major depression. The degree of risk depended on a number of factors, including the definition of subthreshold depression. meta-analysis of seven studies examining the effects of psychological treatments of subthreshold depression showed that these treatments are effective (Cohen's d = 0.42; 95% ci: 0.23-0.60) and that they may well prevent the onset of major depression (incidence rate ratio: 0.70; 95% ci: 0.47-1.03; p < 0.1).

CONCLUSION

Subthreshold depression has serious consequences for the quality of life, but not as serious as in the case of a depressive disorder. Psychological treatment is effective.

Recombinant human deoxyribonuclease for the treatment of acute asthma in children

BACKGROUND

Airway obstruction in acute asthma is the result of airway smooth muscle contraction, inflammation and mucus plugging. Case reports suggest that mucolytic therapy might be beneficial in acute asthma. The aim of this study was to determine the efficacy of the mucolytic drug recombinant human deoxyribonuclease (rhDNase) in addition to standard treatment at the emergency department in children with an asthma exacerbation.

METHODS

In a multicentre randomised double-blind controlled clinical trial, 121 children brought to the emergency room for a moderate to severe asthma exacerbation were randomly assigned to receive either a single dose of 5 mg nebulised rhDNase or placebo following the second dose of bronchodilators. An asthma score (scale 5-15) was assessed at baseline and at 1, 2, 6, 12 and 24 h. The primary outcome variable was the asthma score 1 h after the study medication.

RESULTS

One hour after the study medication the asthma score in the rhDNase group showed an adjusted mean decrease from baseline of 1.0 (95% CI 0.5 to 1.6) points compared with 0.7 (95% CI 0.3 to 1.2) points in the placebo group (mean difference 0.4 (95% CI -0.2 to 1.0) points; p = 0.23). The asthma score over the study period of 24 h also did not differ significantly between the rhDNase and placebo group (mean difference 0.2 (95% CI -0.3 to 0.7) points, p = 0.40). The duration of oxygen supplementation and number of bronchodilator treatments in the first 24 h were similar in both groups.

CONCLUSION

Adding a single dose of nebulised rhDNase to standard treatment in the emergency room has no beneficial effects in children with moderate to severe acute asthma.

Completeness of notification of tuberculosis in The Netherlands: how reliable is record-linkage and capture-recapture analysis?

The aim of this study was to describe a systematic process of record-linkage, cross-validation, case-ascertainment and capture-recapture analysis to assess the quality of tuberculosis registers and to estimate the completeness of notification of incident tuberculosis cases in The Netherlands in 1998. After record-linkage and cross-validation 1499 tuberculosis patients were identified, of whom 1298 were notified, resulting in an observed under-notification of 13.4%. After adjustment for possible imperfect record-linkage and remaining false-positive hospital cases observed under-notification was 7.3%. Log-linear capture-recapture analysis initially estimated a total number of 2053 (95% CI 1871-2443) tuberculosis cases, resulting in an estimated under-notification of 36.8%. After adjustment for possible imperfect record-linkage and remaining false-positive hospital cases various capture-recapture models estimated under-notification at 13.6%. One of the reasons for the higher than expected estimated under-notification in a country with a well-organized system of tuberculosis control might be that some tuberculosis cases, e.g. extrapulmonary tuberculosis, are managed by clinicians less familiar with notification of infectious diseases. This study demonstrates the possible impact of violation of assumptions underlying capture-recapture analysis, especially the perfect record-linkage, perfect positive predictive value and absent three-way interaction assumptions.

Estimating the coverage of a targeted mobile tuberculosis screening programme among illicit drug users and homeless persons with truncated models

Truncated models are indirect methods to estimate the size of a hidden population which, in contrast to the capture-recapture method, can be used on a single information source. We estimated the coverage of a tuberculosis screening programme among illicit drug users and homeless persons with a mobile digital X-ray unit between 1 January 2003 and 31 December 2005 in Rotterdam, The Netherlands, using truncated models. The screening programme reached about two-third of the estimated target population at least once annually. The intended coverage (at least two chest X-rays per person per year) was about 23%. We conclude that simple truncated models can be used relatively easily on available single-source routine data to estimate the size of a population of illicit drug users and homeless persons. We assumed that the most likely overall bias in this study would be overestimation and therefore the coverage of the targeted mobile tuberculosis screening programme would be higher.

Psychological treatments of subthreshold depression: a meta-analytic review

OBJECTIVE

Subthreshold depression has a considerable impact on the quality of life and carries a high risk of developing major depressive disorder. Psychological treatments for subthreshold depression may be able to reduce depressive symptomatology and prevent the onset of major depression.

METHOD

We conducted a meta-analysis of randomized controlled studies examining the effects of psychological treatments for subthreshold depression. We examined the effects on depressive symptoms and the preventive effects on the incidence of major depression.

RESULTS

Seven high-quality studies with a total of 700 subjects were included. The mean effect size at post-test was 0.42 (95% CI: 0.23-0.60), with very low heterogeneity. The relative risk of developing a major depressive disorder in subjects who received the intervention was 0.70 (95% CI: 0.47-1.03; P = 0.07).

CONCLUSION

Psychological treatments have significant effects on subthreshold depression. Furthermore, these interventions may prevent the onset of major depression.

Estimating infectious diseases incidence: validity of capture-recapture analysis and truncated models for incomplete count data

Capture-recapture analysis has been used to evaluate infectious disease surveillance. Violation of the underlying assumptions can jeopardize the validity of the capture-recapture estimates and a tool is needed for cross-validation. We re-examined 19 datasets of log-linear model capture-recapture studies on infectious disease incidence using three truncated models for incomplete count data as alternative population estimators. The truncated models yield comparable estimates to independent log-linear capture-recapture models and to parsimonious log-linear models when the number of patients is limited, or the ratio between patients registered once and twice is between 0.5 and 1.5. Compared to saturated log-linear models the truncated models produce considerably lower and often more plausible estimates. We conclude that for estimating infectious disease incidence independent and parsimonious three-source log-linear capture-recapture models are preferable but truncated models can be used as a heuristic tool to identify possible failure in log-linear models, especially when saturated log-linear models are selected.

Economic costs of minor depression: a population-based study

OBJECTIVE

Although the clinical relevance of minor depression has been demonstrated in many studies, the economic costs are not well explored. In this study, we examine the economic costs of minor depression.

METHOD

In a large-scale, population-based study in the Netherlands (n = 5504) the costs of minor depression were compared with the costs of major depression and dysthymia. Excess costs, i.e. the costs of a disorder over and above the costs attributable to other illnesses, were estimated with help of regression analysis. The direct medical costs, the direct non-medical costs and the indirect non-medical costs were calculated. The year 2003 was used as the reference year.

RESULTS

The annual per capita excess costs of minor depression were US$ 2141 (95% CI = 753-3529) higher than the base rate costs of US$ 1023, while the costs of major depression were US$ 3313 (95% CI = 1234-5390) higher than the base rate. The costs of minor depression per 1 million inhabitants were 160 million dollars per year, which is somewhat less than the costs of major depression (192 million dollars per year).

CONCLUSION

The economic costs associated with minor depression are considerable and approach those of major depression.

[The prevention of psychiatric disorders]

About 450 million people all over the world suffer from psychiatric disorders. Limitations and handicaps are caused especially by unipolar depression, excessive alcohol consumption, schizophrenia and manic-depressive disorder. It is expected that the importance of psychiatric disorders for public health will increase in the coming decades. Psychiatric disorders are often the cause of death, destroy the lives of both patients and their families, have far-reaching economic consequences and are often complicated by somatic diseases. The advances in the field of treatment are impressive but can have only a limited effect on the consequences of psychiatric disorders for public health. The incidence of psychiatric disorders can be reduced by more than 25%. The greatest effects have been seen with depressive disorders, indicated prevention and the use of cognitive therapy. Indicated prevention has also been found to be effective in psychotic disorders. Debriefing is ineffective in posttraumatic stress disorder. The efficacy of universal prevention has not been investigated. There are still insufficient data to develop evidence-based guidelines for the prevention of psychiatric disorders.

Creative reminiscence as an early intervention for depression: results of a pilot project

Reminiscence may help in resolving conflicts from the past and making up the balance of one's life. Life-review may be further enhanced by the creative expression of memories in stories, poems or drawings. In this way people are encouraged to create and discover metaphors, images and stories that symbolically represent the subjective and inner meaning of their lives. In this article, a new intervention, which combines reminiscence and creative expression aimed at early treatment of depression, is described. A pilot project showed that the intervention Searching for the meaning in life may generate small-sized effects in reducing depression. Additionally, it appears to generate effects of medium size in enhancing mastery. Several possible ways to improve the effectiveness of the intervention are described.

Predicting the onset of major depression in subjects with subthreshold depression in primary care: a prospective study

OBJECTIVE

That subjects with subthreshold depression have an increased probability of developing major depression has been confirmed by many studies. However, the factors which may predict the onset of major depression have yet to be fully examined.

METHOD

We examined the control group of a randomized trial in primary care patients with subthreshold depression (N = 109), of whom 20 had developed major depression 1 year later. Using the vulnerability-stress theory, we examined which factors predicted the onset of major depression.

RESULTS

In both univariate and multivariate analyses, family history and chronic illnesses predicted the onset of major depression.

CONCLUSION

It is possible to predict to a certain degree whether a subject with subthreshold depression will develop major depression within a year.

Subthreshold depression as a risk indicator for major depressive disorder: a systematic review of prospective studies

OBJECTIVE

In order to examine whether the incidence of major depressive disorder (MDD) is increased in subjects with subthreshold depression, or sD (clinically relevant depressive symptoms, without meeting criteria for a full-blown MDD), we conducted a review of prospective studies examining the incidence of MDD in subjects with sD.

METHOD

A systematic literature search was conducted. For all studies, the relative risk of developing MDD was calculated, based on person-years.

RESULTS

Twenty studies (23 comparisons) were found, based on community samples, general medical patients and high-risk subjects. Most comparisons showed that subjects with sD had a consistently larger chance of developing MDD. The studies differed considerably in the definition of sD, the recency (occurrence of the last sD) and the in-/exclusion of lifetime MDD.

CONCLUSION

The incidence of MDD in subjects with sD is larger than in subjects without sD. Otherwise, the concept of sD is too broad to be used. In future studies, some consensus should be reached regarding the definition of sD.

Guidance for the safety assessment of botanicals and botanical preparations for use in food and food supplements

There is a growing interest by both consumers and industry for the development of food products with 'functional' properties, or health benefits. These products may take the form of dietary supplements or of foods. The health benefits are given by particular ingredients, and in many cases these are derived from botanicals. The variety of plants providing these functions is large, ranging from staple food sources such as cereals, fruits and vegetables, to herbals as used in traditional medicine. The food or ingredient conferring health properties may consist of the plants themselves, extracts thereof, or more purified components. The scientific literature is abundant with articles not only on the beneficial properties, but also on possible adverse health effects of plants and their components. The present report discusses the data required to determine the safe use of these types of ingredients, and provides advice on the development of risk assessment strategies consistent with due diligence under existing food regulations. Product specifications, composition and characterisation of standardised and authentic materials, documented history of use and comparison to existing products (taking into account the effect of industrial processing), description of the intended use and consequent exposure are highlighted as key background information on which to base a risk evaluation. The extent of experimental investigation required, such as in vitro, animal, and/or human studies, depends on the adequacy of this information. A decision tree is presented as an aid to determine the extent of data requirements based on product comparison. The ultimate safety in use depends on the establishment of an adequate safety margin between expected exposure and identified potential hazards. Health hazards may arise from inherent toxicities or contaminants of the plant materials, including the mechanism of the intended beneficial effect. A lower safety margin may therefore be expected than for food ingredients or additives where no physiological effects are intended. In rare cases, post launch monitoring programmes may be envisaged to confirm expected exposures and adequacy of the safety margin. This guidance document was elaborated by an expert group of the Natural Toxin Task Force of the European Branch of the International Life Sciences Institute--ILSI Europe and discussed with a wider audience of scientists at a workshop held on 13-15 May 2002 in Marseille, France.

[Cannabis use as a probable causative factor in the later development of schizophrenia]

OBJECTIVE

To study the role of cannabis use in the onset of symptoms and disorders in the schizophrenia spectrum.

DESIGN

Literature study.

METHOD

Hypothetical explanations of the relationship between cannabis use and subsequent schizophrenia were assessed on the basis of the results of five large longitudinal studies.

RESULTS

Because cannabis use preceded the development of schizophrenia and as a result of statistical control for possible confounders, the following explanations could be rejected: 'cannabis is used as self-medication for schizophrenia', 'schizophrenia is not caused by cannabis but by other drugs that are used concurrently', and 'cannabis use and schizophrenia are both caused by other factors'. Two explanations then remained: 'cannabis use per se contributes in a unique manner to the risk' and 'cannabis use, in interaction with other risk factors, leads to an increase in the risk'.

CONCLUSION

There are strong indications that cannabis use increases the risk of the subsequent development of symptoms and disorders in the schizophrenia spectrum.

Predictors of first incidence of DSM-III-R psychiatric disorders in the general population: findings from the Netherlands Mental Health Survey and Incidence Study

OBJECTIVE

To investigate determinants of 12-month first incidence of DSM-III-R mood disorder (MD), anxiety disorder (AD) and substance use disorder (SUD) in the general population.

METHOD

Data are from the Netherlands Mental Health Survey and Incidence Study (NEMESIS), a prospective epidemiologic study in which a representative sample of 7076 adults aged 18-64 years were interviewed with the Composite International Diagnostic Interview. New cases diagnosed 12 months after baseline were compared with never diagnosed controls on sociodemographic and psychosocial variables.

RESULTS

Multivariate, the only demographic variable associated with incidence of MD was female gender. The strongest predictors were negative life events and ongoing difficulties. High level of neuroticism was also associated. Incidence of AD was likewise predicted by female gender. Negative life events and ongoing difficulties were also significant predictors, though weaker than for MD. Incidence of SUD was more common among males, young adults, people not living with a partner and those experiencing positive life events.

CONCLUSION

Incident MD and AD were predicted more strongly by life events, and SUD more strongly by demographic factors.

Underreporting of malaria incidence in The Netherlands: results from a capture-recapture study

The aim of this study was to estimate the completeness of notification of malaria by physicians and laboratories in the Netherlands in 1996. We used a capture-recapture (CRC) analysis of three incomplete, partially overlapping registers of malaria cases: a laboratory survey, the Notification Office and the hospital admission registration. The response of the laboratories was 83.2%. In 1996 the laboratories microscopically identified 535 cases of malaria, 330 patients with malaria were admitted to hospital and physicians notified 311 malaria cases. 667 malaria cases were recorded in at least one register. CRC analysis estimated the total number of malaria cases at 774 (95 % CI of 740-821). This implies a completeness of notification of 40.2% for physicians and 69.1% for the laboratories. It can be concluded that laboratory-based notification can considerably increase the number of officially reported malaria cases as compared to notification by physicians. However, possibly one-third of the cases may still go unreported.

Assessing parental alcoholism: a comparison of the family history research diagnostic criteria versus a single-question method

This study compares two methods of determining parental alcoholism: (1) a single question asking whether one of the subject's parents had alcohol problems; (2) the Family History Research Diagnostic Criteria (FH-RDC), which require at least one alcohol-related problem in addition to parental problem drinking. We sought first to determine the level of agreement between the single-question approach and the full FH-RDC for parental alcoholism, and then to gauge how much bias will be introduced by using the single question rather than the FH-RDC-method in assessing the risk for psychiatric disorders. Data were taken from the National Comorbidity Survey (NCS), a nationwide survey of the noninstitutionalized US civilian population aged 15 to 54. Parental alcoholism was assessed both by the single question and by the full FH-RDC. Psychiatric disorders were assessed with the Composite International Diagnostic Interview (CIDI). Good agreement was found between the single-question approach and the FH-RDC (kappa = 0.83). The single-question method introduces only a small downward bias when it comes to assessing the risk for psychiatric disorders in children of alcoholic probands. This underestimation does not reach statistical significance. When a questionnaire needs to be shortened, a single question on parental problem drinking is a good alternative to checking all individual FH-RDC items.

[HIV-positive drug users in South Limburg: number and characteristics, a capture-recapture analysis]

OBJECTIVE

To estimate the number of HIV positive drug abusers (HDs) in South Limburg, the Netherlands, and to ascertain the characteristics of this group, so that special HIV healthcare can be planned.

DESIGN

Capture-recapture analysis.

METHOD

Capture-recapture analysis was carried out and abuser characteristics were determined using three incomplete, partially overlapping registers of HDs from the regional AIDS hospital, the Regional Institute for Addiction and the Municipal Health Service Centres in South Limburg.

RESULTS

From the 80 HDs included, the Municipal Health Service Centres observed 59 HDs, the Institute for Addiction 45 and the hospital 44. The capture-recapture analysis gave an estimate of 110 HDs (95% CI: 91-164) in South Limburg. Assuming 1100 drug users in South Limburg of which 76% had injected on one or more occasions, the HIV prevalence among injecting drug users was estimated at 13% (110/836). From the observed HDs 80% were male, with a mean age of 38 years (SD: 7) and a mean age at the onset of drug use of 18 years (SD: 5). All HDs currently injected or had previously injected. The first injected drugs were used at a mean age of 21 years (SD: 6). All HDs used heroine, 84% also used cocaine, 54% were homeless, 91% unemployed and 80% had a history of imprisonment. Further, 71% of the female HDs were prostitutes, 37% of the male ones visited prostitutes, 81% had contracted hepatitis B (of which 20% were a carrier) and all HDs were infected with hepatitis C. An estimate based on prevalence data gave 143/836 (17%) and that based on capture-recapture analysis with two registrations was 102/836 (12%).

CONCLUSION

The number of HDs was estimated to be 110. The population had a marginalized existence and there was a risk of HIV spreading.

The structure and stability of common mental disorders: the NEMESIS study

BACKGROUND

We analyzed the underlying latent structure of 12-month DSM-III-R diagnoses of 9 common disorders for the general population in the Netherlands. In addition, we sought to establish (1) the stability of the latent structure underlying mental disorders across a 1-year period (structural stability) and (2) the stability of individual differences in mental disorders at the level of the latent dimensions (differential stability).

METHODS

Data were obtained from the first and second measurement of the Netherlands Mental Health Survey and Incidence Study (NEMESIS) (response rate at baseline: 69.7%, n = 7076; 1 year later, 79.4%, n = 5618). Nine common DSM-III-R diagnoses were assessed twice with the Composite International Diagnostic Interview with a time lapse of 1 year. Using structural equation modeling, the number of latent dimensions underlying these diagnoses was determined, and the structural and differential stability were assessed.

RESULTS

A 3-dimensional model was established as having the best fit: a first dimension underlying substance use disorders (alcohol dependence, drug dependence); a second dimension for mood disorders (major depression, dysthymia), including generalized anxiety disorder; and a third dimension underlying anxiety disorders (simple phobia, social phobia, agoraphobia, and panic disorder). The structural stability of this model during a 1-year period was substantial, and the differential stability of the 3 latent dimensions was considerable.

CONCLUSIONS

Our results confirm the 3-dimensional model for 12-month prevalence of mental disorders. Results underline the argument for focusing on core psychopathological processes rather than on their manifestation as distinguished disorders in future population studies on common mental disorders.