Structure and clinical correlates of obsessive-compulsive symptoms in a large sample of children and adolescents: a factor analytic study across five nations.

The underlying structure of obsessive-compulsive disorder (OCD) remains to be confirmed in child and adolescent populations. In this paper we report the first factor analytic study of individual OCD items from Children's Yale-Brown Obsessive Compulsive Scale (CY-BOCS). OCD symptoms were assessed using the CY-BOCS symptom checklist in a sample of 854 patients with OCD (7-18 years of age) recruited from clinics in five countries. Pooled data were subjected to exploratory and confirmatory factor analysis (CFA) to identify the optimal factor structure. Various models were tested for age and gender subgroups. Also, the invariance of the solution across age and gender was tested and associations with demographic and clinical factors were explored. A three-factor model provided the best-fit solution. It consisted of the following factors: (1) harm/sexual, (2) symmetry/hoarding, (3) contamination/cleaning. The factor structure was invariant for age and gender across subgroups. Factor one was significantly correlated with anxiety, and factor two with depression and anxiety. Factor three was negatively correlated with tic disorder and attention-deficit/hyperactivity disorder (ADHD). Females had higher scores on factor two than males. The OCD symptom structure in children and adolescents is consistent across age and gender and similar to results from recent child and adolescents although hoarding may not be a separate factor. Our three-factor structure is almost identical to that seen in early studies on adults. Common mental disorders had specific patterns of associations with the different factors.

Cellular uptake of coumarin-6 under microfluidic conditions into HCE-T cells from nanoscale formulations.

UNLABELLED: In vitro studies of ocular bioavailability of active pharmaceutical ingredients (API) from colloidal drug delivery systems do not consider physiological shear stress generated by eyelid wiping and tear flow. The present study introduces a live cell imaging approach which enables the investigation of model drug uptake from various formulations under shear stress by using custom-made microchannels for the cultivation of human corneal epithelial cells (HCE-T). Coumarin-6 (C-6) was used as a model API incorporated into solid lipid nanoparticles and liposomes, and as an aqueous crystalline suspension. Confocal laser scanning microscopy visualized C-6 uptake into HCE-T cells in a time-resolved manner with an applied shear stress of 0.1 Pa. Static conditions were also studied for comparative purposes. Additionally, solid lipid nanoparticles (SLN) were labeled with a fluorescent phospholipid to check whether C-6 uptake was associated with SLN incorporation into the cells. RESULTS: Intact SLN were not incorporated into the cells, i.e., C-6 was passively redistributed from SLN to lipophilic cellular compartments. C-6 was enriched up to a given limit in HCE-T cells within 5 min of contact with the dispersions both under static and under flow conditions. The C-6 delivery rate from liposomes was superior to that from SLN whereby the suspension exhibited the lowest rate. C-6 release rates were comparable for static and flow conditions. Alternate flushing with formulations and buffer revealed that cells accumulated C-6. The results suggest that combining microfluidics with live cell imaging provides a valuable option for in vitro studies of ocular drug delivery.

Localizing and extracting filament distributions from microscopy images.

Detailed quantitative measurements of biological filament networks represent a crucial step in understanding architecture and structure of cells and tissues, which in turn explain important biological events such as wound healing and cancer metastases. Confocal microscope images of biological specimens marked for different structural proteins constitute an important source for observing and measuring meaningful parameters of biological networks. Unfortunately, current efforts at quantitative estimation of architecture and orientation of biological filament networks from microscopy images are predominantly limited to visual estimation and indirect experimental inference. Here we describe a new method for localizing and extracting filament distributions from 2D confocal microscopy images. The method combines a filter-based detection of pixels likely to contain a filament with a constrained reverse diffusion-based approach for localizing the filaments centrelines. We show with qualitative and quantitative experiments, using both simulated and real data, that the new method can provide more accurate centreline estimates of filament in comparison to other approaches currently available. In addition, we show the algorithm is more robust with respect to variations in the initial filter-based filament detection step often used. We demonstrate the application of the method in extracting quantitative parameters from an experiment that seeks to quantify the effects of carbon nanotubes on actin cytoskeleton in live HeLa cells. We show that their presence can disrupt the overall actin cytoskeletal organization in such cells.

Preliminary validity testing of the eHealth Literacy Questionnaire (eHLQ): a Confirmatory Factor Analysis (CFA) in Norwegian hospitalized patients.

AIMS: To perform the first psychometric analysis of the Norwegian version of the eHLQ using confirmative factor analysis (CFA) procedures in a population of patients admitted to hospital using a cross-sectional design. The eHLQ consists of 35 items capturing the 7-dimensional eHealth Literacy Framework (eHLF) which describes users' attributes, user's interaction with technologies and user's experience with digital health systems. METHODS: The 7 independent scales of the eHLQ was translated from Danish and culturally adapted into the Norwegian language following a standardised protocol. Assessment of construct validity of the eHLQ was undertaken using data from a cross-sectional survey of 260 patients hospitalized at a Norwegian University Hospital in the Oslo area during a two-week period in June 2021. The analysis included using correlation analysis (Pearsons R), internal consistency (Cronbach's alpha) and confirmatory factor analysis (CFA). RESULTS: All factor loadings were high to acceptable (i.e. > 0.6), except for five items which had somewhat lower loadings. Regarding internal consistency, alpha ranged from 0.73 to 0.90. For optimal CFA fit for the different scale models, correlated residuals were required for five of the seven scales. Overall our analysis shows an intermediate fit of the orginal construct. Scale intercorrelations were all below 0.8, indicating an overall acceptable discriminant validity between the 7 dimensions. CONCLUSIONS: The results from the CFA analysis indicate that for almost all 7 eHLQ scales, an acceptable model fit was achieved. The 260 hospitalized patients included in this study represented a variety of diagnoses, recruited from a geographically limited area. Further studies on psychometric properties of the Norwegian version of eHLQ in larger samples, diverse settings and by using more comprehensive approaches are warranted.

Does oral health matter in people's daily life? Oral health-related quality of life in adults 35-47 years of age in Norway.

OBJECTIVE: The aim of this study was to assess the effect of oral health on aspects of daily life measured by the Dental Impact Profile (DIP) in 35- to 47-year-old individuals in Norway, and to study associations between reported effects and demographic variables, subjectively assessed oral health, general health, oral health behaviour and clinical oral health. MATERIAL AND METHODS: A stratified randomized sample of 249 individuals received a questionnaire regarding demographic questions, dental visits, oral hygiene behaviour, self-rated oral health and general health and satisfaction with oral health. The DIP measured the effects of oral health on daily life. Teeth present and caries experience were registered by clinical examination. Bi- and multivariate analyses and factor analysis were used. RESULTS: Items most frequently reported to be positively or negatively influenced by oral health were chewing and biting, eating, smiling and laughing, feeling comfortable and appearance. Only 1% reported no effects of oral health. Individuals with fewer than two decayed teeth, individuals who rated their oral health as good or practised good oral health habits reported more positive effects than others on oral quality of life (P ≤ 0.05). When the variables were included in multivariate analysis, none was statistically significant. The subscales of the DIP were somewhat different from the originally suggested subscales. CONCLUSIONS: This study showed that most adults reported oral health to be important for masticatory functions and confirmed that oral health also had impacts on other aspects of life.

Knowledge of prenatal screening and psychological management of test decisions.

OBJECTIVES: To study associations between pregnant women's knowledge of prenatal screening and decisional conflict in deciding whether to participate in first-trimester screening for Down syndrome in a setting of required informed consent, and to study associations between knowledge and personal wellbeing, and worries in pregnancy. METHODS: A population-based cross-sectional study with 6427 pregnant women consecutively included before the time of a nuchal translucency scan. Participants were recruited from three Danish obstetric departments offering prenatal screening free of charge. The results presented are based on 4111 pregnant women (64%). Knowledge was measured using 15 questions. The primary outcomes were measured using pre-existing validated scales, i.e. The Decisional Conflict Scale, the WHO Well-Being Index and the Cambridge Worry Scale. Associations were analyzed by multivariate logistic and linear regression analyses. RESULTS: A higher level of knowledge was associated with less decisional conflict when deciding whether to participate in first-trimester Down syndrome screening (adjusted odds ratio 1.31 (95% CI, 1.26-1.37)). An increased level of knowledge was also associated with higher levels of wellbeing (adjusted linear coefficient 0.51 (95% CI, 0.26-0.75), P < 0.001). Knowledge was not associated with worries, either in general or specifically about something being wrong with the baby. CONCLUSION: The results of this study indicate the importance of ensuring a high level of knowledge for pregnant women making choices about participation in prenatal screening for Down syndrome in order to improve the psychological management of test decisions.

First-trimester Down syndrome screening: pregnant women's knowledge.

OBJECTIVES: The primary aim of this study was to assess pregnant women's knowledge of first-trimester combined Down syndrome screening in a setting of required informed consent. As the secondary aim, we wanted to identify relevant differences in knowledge level among subgroups of pregnant women, including those informed in different ways about prenatal examinations. METHODS: Data stem from a population-based cross-sectional questionnaire study including 15 multiple-choice questions assessing knowledge of different aspects of screening. Included were 6427 first-trimester pregnant women from three Danish obstetric departments offering prenatal screening free of charge. Both participants and non-participants in the screening program were included. The results are based on 4095 responders (64%). Differences between subgroups were examined using chi-squared tests and logistic regression analysis. Estimates are stated with 95% CI. RESULTS: The majority of the participants (87.6 (86.6-88.6)% to 92.6 (91.7-93.3)%) correctly identified the test concept and the main condition being screened for. Fewer participants (16.4 (15.3-17.6)% to 43.3 (41.8-44.8)%) correctly recognized test accuracy and the potential risk of adverse findings other than Down syndrome. Knowledge level was positively associated with length of education (adjusted ORs 1.0 (0.8-1.4) to 3.9 (2.4-6.4)) and participation in the screening program (adjusted OR 0.9 (0.6-1.3) to 5.9 (3.9-8.8)). Participation in an individual information session was weakly associated with more knowledge. CONCLUSION: The majority of the pregnant women correctly identified the test concept and the main condition being screened for. The pregnant women were found less knowledgeable on test accuracy and drawbacks.

Oral health-related quality of life among adults 68-77 years old in Nord-Trøndelag, Norway.

Dental health has mostly been measured by dental staff disregarding patient's experiences. However, clinical conditions alone do not fully indicate how people feel affected by their oral status. The aim of this study was to investigate how clinical recorded dental health, self-rated dental health, satisfaction with dental health were related to oral health-related quality of life (OHRQoL) assessed by Oral Health Impact Profile (OHIP-14) in 68-77 years old. A total of 151 individuals completed a questionnaire on self-rated dental health, satisfaction with dental health and the short form of OHIP-14. Clinical examination was performed registering number of teeth and dental caries. In total 63% of the individuals rated their dental health as good, and 59% were satisfied with their dental health. Using the OHIP-14 42% reported no problems or oral discomfort at all. The proportion of individuals reporting problems or discomfort varied between 13% and 43% according to the dimensions of OHIP-14. The most frequently reported problems were physical pain (43%), psychological discomfort (28%) and psychological disability (28%). Individuals who rated their dental health as poor and those who were dissatisfied with their dental health had significantly lower OHRQoL than other individuals. The study showed relationship between self-evaluations of dental health and OHRQoL in 68-77 years old. Individuals with few teeth reported lower OHRQoL than others, but no association between clinical caries status and OHRQoL could be found.

Hysteroscopic resectoscope-directed biopsies and outpatient endometrial sampling for assessment of tumor histology in women with endometrial cancer or atypical hyperplasia.

OBJECTIVE: To evaluate and compare the diagnostic efficiency of outpatient endometrial sampling (OES) and hysteroscopic resectoscope-directed biopsies (HYbiopsy) to distinguish between endometrial cancer (EC) and atypical hyperplasia (AH) and to assess tumor type and grade (histotype) in women with EC. DESIGN: Patients with AH or EC (n = 266) among 1013 patients consecutively referred because of postmenopausal bleeding were included. Identification of EC versus AH, and unfavorable tumor types (endometrioid grade 3 or non-endometrioid tumors) using OES and HYbiopsy was compared to final histopathology at hysterectomy. AH or EC were identified by OES in 184 patients and by HYbiopsy in212. RESULTS: OES had only sufficient tissue samples in 72.7% of intended samples. Even when OES did provide sufficient material, addition of HYbiopsy was a better technique than OES alone to distinguish between EC and AH, with an AUC of 95.9% and 79.8%; sensitivity of 97.4% and 64.6% and a specificity of 94.4% and 95.0%, respectively (p = 0.008). AH was falsely diagnosed with OES in 58 (35.4%) of 164 women with a final diagnose of EC. A final diagnosis of stage 1b or more was seen in 22 of these 58 women, while 5 of 194 patients with EC all stage 1a grade 1 had AH by HYbiopsy. HYbiopsy had higher correlation in assessment of tumor type and grade than OES, but OES and HYbiopsy had comparable AUC of 90.3% and 92.4% for identification of unfavorable tumors when tumor histotype was successfully identified. Regarding identification of unfavorable tumors (n = 57), a successfully assessment of histotype by OES combined with HYbiopsy in women without successfully diagnosed histotype by OES alone had AUC of 91.3%. CONCLUSION: Addition of HYbiopsy may improve diagnosis when preoperative OES identifies AH or is insufficient for explicit diagnosis of tumor type and grade. However, there is limited benefit of the addition of HYbiopsy in the presence of definite diagnosis of grade 1-2 endometrioid tumors by OES.

Role of nitrogen dioxide in the biosynthesis of nitraosamines in mice.

Groups of three to four mice were gavaged with aqueous solutions of 2 milligrams of morpholine, after which they were exposed to nitrogen dioxide in inhalation chambers at concentrations of 0.2 to 50 parts per million for up to 4 hours. At sequential intervals during the exposure, mice were frozen and pulverized in liquid nitrogen, and the mice powder was extracted with ice-cold 35 percent aqueous methanol and dichloromethane; organic-phase concentrates were analyzed for N-nitrosomorpholine with a thermal energy analyzer interfaced to a gas chromatograph. The N-nitrosomorpholine yields, ranging up to about 2.3 micrograms per mouse, were time-dependent relative to the duration of exposure to nitrogen dioxide and dose-dependent relative to the concentrations of nitrogen dioxide; control levels (in mice that were gavaged with morpholine or distilled water and then exposed to air instead of nitrogen dioxide) were less than 5 nanograms per mouse. These preliminary studies demonstrate the in vivo nitrosating potential of nitrogen oxides.

Naturally occurring antihormones: secretion of FSH antagonists by women treated with a GnRH analog.

Follicle-stimulating hormone (FSH) is a glycoprotein essential for gonadal development and steroidogenesis. Recent studies suggest that deglycosylation of FSH results in the formation of antagonistic proteins that are capable of binding to gonadal receptors but that are devoid of bioactivity. Treatment of hypogonadal women with an antagonist of gonadotropin-releasing hormone substantially decreased serum FSH bioactivity with minimal changes in immunoreactivity. Chromatofocusing and size fractionation of the serum samples indicated the secretion of immunoreactive FSH isoforms that are devoid of bioactivity but that are capable of blocking FSH action in ovarian granulosa cells. These findings provide the first demonstration of naturally occurring circulating antihormones. These FSH antagonists may play an important role in the physiology and pathophysiology of the gonads.

Identification of endometrial cancers and atypical hyperplasia: Development and validation of a simplified system for ultrasound scoring of endometrial pattern.

OBJECTIVES: To derive and validate a practical scoring system for identification of endometrial cancer (EC) or atypical hyperplasia (AH) using transvaginal ultrasonography (TVS) and gel infusion sonography (GIS) in women with postmenopausal bleeding (PMB). STUDY DESIGN: Endometrial pattern was correlated with endometrial pathology in consecutive women with PMB in both a derivation study (N = 164) and a validation study (N = 711). Logistic regression was used to derive and validate two scoring systems (A and B) for prediction of EC/AH: scoring system A was Doppler score + interrupted endo-myometrial junction (IEJ) (2 points); and scoring system B was Doppler score + IEJ (1 point) + Irregular Endometrial Outline (IESO) by GIS (1 point); the Doppler score was based on the presence of more than one single or double vessel (1 point) + multiple vessels (1 point) + large vessels (1 point). OUTCOME MEASURES: Diagnostic performance and calibration curves for identification of EC/AH. RESULTS: Both scoring systems had good observer agreement. VALIDATION DATA: Scoring was most effective with endometrial thickness (ET) ≥ 8 mm. Both scoring systems were well calibrated and performed satisfactorily in women with ET ≥ 8 mm. The sensitivity and specificity of a score of ≥ 2 points in system A were 92% and 84%; the respective values were 89% and 88% in system B. CONCLUSIONS: Scoring was highly efficient in identifying EC/AH. Four risk groups of EC/AH may guide the management of women with PMB: very low (ET < 4 mm), low (ET 4-7.9 mm), intermediate (ET ≥ 8 mm and score < 2 points) and high risk (ET ≥ 8 mm and score ≥ 2 points).

Biosynthesis of dimethylnitrosamine in dimethylamine-treated mice after exposure to nitrogen dioxide.

These studies demonstrate the nitrosating potential of NO2 in vivo in ICR mice. Groups of mice were gavaged with 2 mg dimethylamine (DMA) and exposed to NO2 at levels from 0.04 to 44.5 ppm for periods up to 4 hours. Mice were individually frozen and blended to a powder, aliquots of which were homogenized in ice-cold dicholoromethane and 35% aqueous methanol. Concentrates of organic extracts were analyzed or dimethylnitrosamine (DMN) by a Thermal Energy Analyzer with a gas chromatograph interface. Biosynthesis of DMN was dose- and time-dependent with relation to NO2 exposure, reaching a maximum yield of 60-70 ng/mouse (0.0035% DMA conversion) at 2 hours. DMN biosynthesis was inhibited by sodium ascorbate and, more effectively, by ammonium sulfamate.

Genetic diversity of the NE Atlantic sea urchin Strongylocentrotus droebachiensis unveils chaotic genetic patchiness possibly linked to local selective pressure.

We compared the genetic differentiation in the green sea urchin Strongylocentrotus droebachiensis from discrete populations on the NE Atlantic coast. By using eight recently developed microsatellite markers, genetic structure was compared between populations from the Danish Strait in the south to the Barents Sea in the north (56-79°N). Urchins are spread by pelagic larvae and may be transported long distances by northwards-going ocean currents. Two main superimposed patterns were identified. The first showed a subtle but significant genetic differentiation from the southernmost to the northernmost of the studied populations and could be explained by an isolation by distance model. The second pattern included two coastal populations in mid-Norway (65°N), NH and NS, as well as the northernmost population of continental Norway (71°N) FV. They showed a high degree of differentiation from all other populations. The explanation to the second pattern is most likely chaotic genetic patchiness caused by introgression from another species, S. pallidus, into S. droebachiensis resulting from selective pressure. Ongoing sea urchin collapse and kelp forests recovery are observed in the area of NH, NS and FV populations. High gene flow between populations spanning more than 22° in latitude suggests a high risk of new grazing events to occur rapidly in the future if conditions for sea urchins are favourable. On the other hand, the possibility of hybridization in association with collapsing populations may be used as an early warning indicator for monitoring purposes.

Left ventricular systolic and diastolic function assessed with two-dimensional and doppler echocardiography in "white coat" hypertension.

OBJECTIVES: The aim of this study was to investigate left ventricular function in subjects with "white coat" hypertension, defined as office arterial diastolic pressure > or = 90 and ambulatory daytime pressures < 140/90 mm Hg. BACKGROUND: The white coat arterial pressure response may, by influencing left ventricular function, have a confounding effect in studies of heart disease. METHODS: Two-dimensional and Doppler echocardiography combined with the calibrated subclavian arterial pulse tracing, were used to assess variables of left ventricular function in 26 subjects with white coat hypertension (office arterial diastolic pressure > or = 90 and < 115 mm Hg and ambulatory daytime diastolic pressure > or = 90 mm Hg) and 32 normotensive subjects. RESULTS: In subjects with white coat hypertension, systolic arterial pressure during the echocardiographic examination was significantly higher than ambulatory daytime systolic pressure. This pressure response was positively related to the ratio of the systolic to diastolic pulmonary venous flow peak velocities and to the peak velocity of flow reversion during atrial systole; it was inversely related to the ratio of early to late mitral flow peak velocities. Left ventricular stroke volume, ejection fraction and velocity of circumferential fiber shortening did not differ in the study groups, but left ventricular external work and end-systolic wall stress were increased in the white coat group. CONCLUSIONS: The arterial pressure response in subjects with white coat hypertension is associated with increased left ventricular external work, increased end-systolic wall stress and alterations of left ventricular filling but normal ejection fraction and velocity of circumferential fiber shortening.

The bacterial flora of alpha-Gal knockout mice express the alpha-Gal epitope comparable to wild type mice.

The human genome possesses pseudogenes for the enzyme alpha1,3 galactosyltransferase and hence, human cells and tissues do not express the Galalpha terminated trisaccharide structure Galalpha1-3Galbeta1-4GlcNAc, the so-called alpha-Gal epitope. Circulating antibodies specific for this carbohydrate epitope are, however, present in high amounts in humans. It has previously been hypothesized that the antibody production is induced by the presence of the alpha-Gal epitope in the cell walls of the enteric flora, especially Enterobacteriaceae spp. However, in mice, in which the epitope has been deleted by targeted mutation of the gal-transferase gene, alpha-Gal antibodies do not appear without prior immunization, although the mice through their growth probably have been exposed to a normal bacterial flora of e.g. Enterobacteriaceae spp. It is unknown whether there are different types of immune reactions to antigenic carbohydrate expressing bacteria and whether there are discrepancies in the enteric flora between these knockout mice and their wild type litter mates. In this study the enteric flora of alpha-Gal knockout and wild type mice was compared both in relation to the prevalence of different types of bacteria in the two groups of mice, as well as in relation to the expression of the epitope on the surface of Enterobacteriaceae spp. Our results showed that the enteric flora did not differ significantly between knockout and wild type mice and that it was comparable to the flora known to be present in the intestines of other mice. All Enterobacteriaceae spp. examined expressed the alpha-Gal epitope no matter whether they were isolated from knockout or wild type mice. It is, therefore, discussed whether it is more reasonable to assume that alpha-Gal antibodies in mammals that do not produce alpha1,3 galactosyltransferase such as in the knock mice and in humans are the result of another antigen stimulant than these common representatives of the enteric flora, that we isolated from the two types of mice. Possible candidates for a carrier in humans could be bacteria or viruses not isolated from barrier-bred mice.

Solvent dependence of the spectra and kinetics of excited-state charge transfer in three (alkylamino)benzonitriles.

Steady-state absorption and emission spectra and emission decay kinetics are reported for 4-aminobenzonitrile (ABN), 4-(1-azetidinyl)benzonitrile (P4C), 4-(1-pyrrolidinyl)benzonitrile (P5C), and 4-(1-piperidinyl)benzonitrile (P6C) in 24 room temperature solvents. In solvents of modest to high polarity, P4C, P5C, and P6C exhibit dual fluorescence and emission decays characteristic of the transformation from an initially prepared (LE) state to a more polar charge transfer (CT) state, whereas ABN does not undergo this reaction. The frequencies of the steady-state absorption and emission spectra of all of these solutes can be rationalized using a dielectric continuum description of the solvent and considering only the minima on the reactive surfaces, which are assumed to involve both an intramolecular (twisting) and a solvation coordinate. Characteristics of the gas-phase solutes deduced from this analysis are in good agreement with electronic structure calculations and indicate that differences in their spectra mainly reflect differences in the relative energies of the gas-phase LE and CT states. The relative yields of LE and CT emission are not described as satisfactorily by this model, and reasons for this failure are discussed. The kinetics of the LE --> CT reaction vary considerably with solute and solvent. In many solvents, the emission decays of P4C are reasonably described by a simple two-state kinetic scheme with time-independent rate constants. In P5C and P6C multiexponential decays are observed that reflect time-dependent shifts of the component spectra as well as time-dependent reaction rates. A simplified analysis of these complex dynamics provides estimates for both the free energy change Delta(r)G and (average) LE --> CT rate constant k(f) for a wide range of solute and solvent combinations. The driving force for reaction (-Delta(r)G) follows the order P6C > P5C > P4C and increases with increasing solvent polarity. The reaction rates are correlated to Delta(r)G and follow the opposite trend. The relationships observed between k(f) and Delta(r)G suggest that static solvent effects, i.e., barrier height changes, are the primary determinants of the solvent dependence in P4C. Correlations between barrier-corrected rates and solvation times suggest that dynamical solvent effects contribute substantially to the solvent dependence of the rates in P5C, and especially P6C.

Identification of sentinel nodes in patients with colon cancer.

AIMS: Lymphatic mapping and sentinel node biopsy entails better staging in malignant melanoma and breast cancer and we used this technique in patients with colon cancer to possibly improve detection of lymphatic spread. METHODS: Thirty patients with invasive adenocarcinomas were investigated. The tumour status in identified sentinel node(s) was compared with the status in all other harvested regional nodes for each patient. Patients were followed at regular visits for more than 30 months. RESULTS: Sentinel nodes were identified in all cases, either per-operatively (28 cases) or at dissection of the formalin-fixed specimen (2 cases). The sentinel nodes were diagnostic for the entire lymphatic field in 28 patients and the false negative rate was 2/12. In four cases, the sentinel nodes were the only metastatic nodes. After at minimum 30 months, three patients had died of colon cancer metastases. CONCLUSION: This method improved the identification of patients with lymph-node metastases, especially those with only few metastatic nodes. Patients dying from metastatic disease had lymph-node metastases at diagnosis.