In Caucasians, the patterns of alcohol use disorders in women and adolescents are likely to be different from those in men and adults, respectively. The authors examined these differences in a Southeast Asian sample of Thai people living in communities. A two-parameter logistic model of the IRT log-likelihood-ratio (IRTLR) test for differential item functioning (DIF) procedure was used. Participants were a subsample of 3718 current drinkers participating in the 2008 Thai National Mental Health Survey (n=17,140). The 1-year prevalence rates of alcohol dependence were 1.4% in women and 13.7% in men. Based on the Mini International Neuropsychiatric Interview (MINI), alcohol dependence and abuse module, all current drinkers were interviewed for a yes/no response to each of seven alcohol dependence criteria. Confirmatory factor analysis suggested a single-factor model of alcohol dependence criteria (χ2=211.51, RMSEA=0.06, SRMR=0.03 and CFI=0.96). Compared with 3174 men, 544 women had a significantly higher threshold estimate for quit/control problems and a lower threshold value for drinking despite physical/mental problems (b parameter difference of 0.25 and -0.30, respectively). Thai adolescents (n=272) and Thai adults (n=3446) had no statistically significant DIF on any criterion. The criterion of time spent drinking had significantly high discrimination estimates in women, men, adolescent and adults (a parameters of 2.50, 2.08, 2.33 and 2.16, respectively). Gender bias on alcohol dependence criteria can be found in Thai drinkers. Time spent drinking may be the most useful criterion for discriminating the severity of alcohol dependence across age and gender groups of Thai drinkers.

The polymerase chain reaction (PCR), direct immunofluorescence (DIF; JMAGEN Chlamydia, DAKO Diagnostics, UK), cell culture (CC) and enzyme immunoassay (EIA; Syva Micro Trak) were evaluated for detection of Chlamydia psittaci in bull semen. Three specimens were collected from each of 47 bulls at 3-6 month intervals (134 samples). Judging by the number of samples tested (n = 134), PCR showed a sensitivity of 90.9%, DIF of 93.9%, CC of 72.7% and EIA of 81.8%. PCR, DIF, CC and EIA were 100% specific, respectively. Of the 47 bulls the maximum number of chlamydia-positive animals (n = 14) was revealed when repeated tests were made by PCR. PCR detected 21.4% more positives than DIF and CC and 35.7% more than EIA. Although CC was less sensitive judging by the number of samples tested, it was as sensitive as DIF (78.6%) when judged by the number of bulls investigated. All bulls found to be chlamydia-positive remained so throughout the investigation, which lasted 18 months.

In this study, the SF-36 Health Survey was translated into two oral Moroccan languages and the existing Turkish version was culturally adapted for use in The Netherlands, and was tested among 79 Moroccan and 90 Turkish cancer patients. There were normal levels of missing item responses but a higher administration time. With minor exceptions, the scale structure of the SF-36 was confirmed and the reliability of the scales met the 0.70 criterion for group comparisons. The questionnaire distinguished clearly between subgroups formed on the basis of performance status and was responsive to change in performance status over time. Some evidence of differential item function (DIF) was found in both ethnic groups. These results support the use of the SF-36 among Turkish and Moroccan cancer patients in The Netherlands. Additional studies are needed to confirm the psychometrics of the questionnaire when used among these ethnic minority groups in other Western European countries.

BACKGROUND

Theoretical and clinical publications suggest the existence of cultural differences in the expression and experience of depression. Measurement non-equivalence remains a potential methodological explanation for the lower prevalence of depression among Asian Americans compared to European Americans.

METHODS

This study compared DSM-IV depressive symptoms among Asian Americans and European Americans using secondary data analysis of the Collaborative Psychiatric Epidemiology Surveys (CPES). The Composite International Diagnostic Interview (CIDI) was used for the assessment of depressive symptoms. Of the entire sample, 310 Asian Americans and 1974 European Americans reported depressive symptoms and were included in the analyses. Measurement variance was examined with an item response theory differential item functioning (IRT DIF) analysis.

RESULTS

χ2 analyses indicated that, compared to Asian Americans, European American participants more frequently endorsed affective symptoms such as 'feeling depressed', 'feeling discouraged' and 'cried more often'. The IRT analysis detected DIF for four out of the 15 depression symptom items. At equal levels of depression, Asian Americans endorsed feeling worthless and appetite changes more easily than European Americans, and European Americans endorsed feeling nervous and crying more often than Asian Americans.

CONCLUSIONS

Asian Americans did not seem to over-report somatic symptoms; however, European Americans seemed to report more affective symptoms than Asian Americans. The results suggest that there was measurement variance in a few of the depression items.

Patterns and correlates of comorbidity, as well as differences in manifest depressive profiles were investigated in a sample of depressed adolescents. A sub-sample of the youth were characterized as belonging to either a Pure depression group, an Internalizing group (depression and co-occurring internalizing disorders), or an Externalizing group (depression and co-occurring externalizing disorders). Item response theory (IRT) and differential item functioning (DIF) were used to assess whether the depressed adolescents from the different comorbidity groups presented with different depressive symptoms. Results indicated that the comorbidity groups were meaningfully distinct in terms of psychosocial correlates as well as showed differences in depressive symptom profiles as informed by DIF analyses. In particular, the comorbidity groups differed in terms of presentation of psychomotor changes and cognitive impairments. Implications for assessment are discussed.

We recently described a new variant of endemic pemphigus foliaceus (EPF) in El Bagre, Colombia, that resembles Senear-Usher syndrome and identified autoantibodies to desmoglein 1 (Dsg1), as well as to multiple known and unknown antigens including plectins, in the serum of these patients. Here, we developed a cost-effective ELISA assay capable of detecting the heterogeneous antibody population observed in these EPF patients, and useful for serum epidemiological studies. A protein extract obtained from trypsin-digested fresh bovine skin and further purified on a concanavalin A matrix was used as antigen. This extract contains an important conformational epitope (a 45 kDa tryptic fragment of the Dsg1 ectodomain), which is recognized by antibodies in serum from patients with all varieties of pemphigus foliaceus (PF), and from half of those with pemphigus vulgaris with active clinical disease. The cut-off and threshold values were normalized using human serum obtained from both endemic and non-endemic areas for PF. The efficiency of this ELISA was tested using 600 serum samples from controls and patients diagnosed with EPF, non-endemic PF and other bullous diseases. The overall sensitivity and specificity of the assay were determined to be 95% and 72%, respectively, with reproducibilities of 98% (intraassay) and 95% (interassay). Comparing the ELISA with other tests to detect EPF autoantibodies, this ELISA was the most sensitive, followed by direct immunofluorescence (DIF), indirect immunofluorescence using anti-IgG4 monoclonal antibodies and immunoprecipitation (IP), respectively. The most specific assay was IP, followed by DIF. Immunoblotting to Dsg1 exhibited both poor sensitivity and poor specificity, although plectins were well visualized. We conclude that this ELISA is an excellent tool for field serological studies, allowing testing of multiple serum samples simultaneously and for detecting, with appropriate restriction and sensitivity, the heterogeneous antibody population seen in patients with this variant of EPF. Finally, autoantibody serum levels obtained with this ELISA correlated well with the clinical activity and extent of disease in patients with El Bagre EPF.

BACKGROUND

Depression is a common complication in type 2 diabetes (DM2), affecting 10-30% of patients. Since depression is underrecognized and undertreated, it is important that reliable and validated depression screening tools are available for use in patients with DM2. The Edinburgh Depression Scale (EDS) is a widely used method for screening depression. However, there is still debate about the dimensionality of the test. Furthermore, the EDS was originally developed to screen for depression in postpartum women. Empirical evidence that the EDS has comparable measurement properties in both males and females suffering from diabetes is lacking however.

METHODS

In a large sample (N = 1,656) of diabetes patients, we examined: (1) dimensionality; (2) gender-related item bias; and (3) the screening properties of the EDS using factor analysis and item response theory.

RESULTS

We found evidence that the ten EDS items constitute a scale that is essentially one dimensional and has adequate measurement properties. Three items showed differential item functioning (DIF), two of them showed substantial DIF. However, at the scale level, DIF had no practical impact. Anhedonia (the inability to be able to laugh or enjoy) and sleeping problems were the most informative indicators for being able to differentiate between the diagnostic groups of mild and severe depression.

CONCLUSIONS

The EDS constitutes a sound scale for measuring an attribute of general depression. Persons can be reliably measured using the sum score. Screening rules for mild and severe depression are applicable to both males and females.

Pathological examinations of 233 consecutive autopsy cases with nonasbestos pneumonconiosis revealed evidence of diffuse interstitial fibrosis (DIF) in 64 (27.5%), among whom 45 (19.3%) showed bilateral involvement and 9 (3.9%) extensive disease closely resembling usual interstitial pneumonia. The patients with DIF were significantly older and had longer occupational histories as compared with those without DIF. There was no correlation between the occurrence of DIF and the type of the underlying disease (silicosis or mixed dust pneumoconiosis) except that an extensive DIF was more frequently associated with mixed dust pneumoconiosis. The extensive DIF developed an in situ malignancy much more frequently (33.3%) than the focal disease (2.6%).

OBJECTIVE

To propose a permutation-based approach of anchor item detection and evaluate differential item functioning (DIF) related to language of administration (English vs. Spanish) for 9 questions assessing patients' perceptions of their providers from the Consumer Assessment of Healthcare Providers and Systems (CAHPS) Medicare 2.0 survey. METHOD AND STUDY DESIGN: CAHPS 2.0 health plan survey data collected from 703 Hispanics who completed the survey in Spanish were matched on personal characteristics to 703 Hispanics that completed the survey in English. Steps to be followed for the detection of anchor items using the permutation tests are proposed and these tests in conjunction with item response theory were used for the identification of anchor items and DIF detection.

RESULTS

Of the questions studied, 4 were selected as anchor items and 3 of the remaining questions were found to have DIF (P < 0.05). The 3 questions with DIF asked about seeing the doctor within 15 minutes of the appointment time, respect for what patients had to say, and provider spending enough time with patients.

CONCLUSIONS

Failure to account for language differences in CAHPS survey items may result in misleading conclusions about disparities in health care experiences between Spanish and English speakers. Statistical adjustments are needed when using the items with DIF.

OBJECTIVE

This study explored the validity of the First International Consensus on Mucous Membrane Pemphigoid (MMP) guidance, which recommends that clinically indistinguishable patients, who have direct immunofluorescence (DIF)-negative biopsies, be excluded from a diagnosis of MMP. Misdiagnosis, or delayed diagnosis, of MMP with ocular involvement leads to the inappropriate use of topical therapy, the standard of care for causes of cicatrising conjunctivitis other than MMP, rather than systemic immunomodulatory therapy, resulting in irreversible clinical deterioration in patients with MMP.

METHODS

Prospective, cross-sectional study.

METHODS

Patients meeting the clinical criteria of ocular MMP, including those with positive and negative DIF findings.

METHODS

A case report form was used to collect the demographic details, the clinical history, and the results of a detailed clinical assessment by ophthalmologists, otolaryngologists, dermatologists, and oral medicine specialists. All anatomic sites potentially affected by MMP were examined apart from the esophagus (and larynx in a subset). The DIF results were recorded.

METHODS

Differences between DIF-positive and -negative patients in demography, sites of involvement, and disease severity as determined by the degree of conjunctival scarring (using Tauber staging), central corneal disease (vascularization, scarring, ulceration, and conjunctivalization), history of conjunctival or lid surgery, and requirement for systemic immunotherapy at the time of screening.

RESULTS

A total of 73 patients with ocular MMP were recruited, of whom 20 of 73 (27.4%) had ocular-only disease. There was no significant demographic or clinical difference between patients with positive and negative DIF results. This finding included differences in disease severity for which the only significant difference was that of more severe central corneal disease in DIF-negative patients. Asymptomatic disease at different sites was frequent.

CONCLUSIONS

These findings do not support the classification of DIF-negative patients, meeting the clinical criteria for ocular MMP, as having a different disease. This category of patients should be accepted as having DIF-negative MMP, for clinical management purposes, with patients having inflamed eyes being treated with systemic immunomodulatory therapy. The frequent finding of asymptomatic ocular, oral, and nasopharyngeal MMP is clinically significant and implies that these sites should be routinely screened in asymptomatic patients.

The aim of this study was to determine the stability of three ester prodrugs, chloramphenicol succinate, enalapril and candesartan cilexetil, in human proximal small intestinal fluid (HIF), dog proximal small intestinal fluids (DIF) and simulated intestinal fluid (FaSSIF), with the addition of pancreatin. The total protein content in the proximal jejunal fluids was determined in HIF and DIF, respectively. Candesartan cilexetil was significantly degraded in HIF (initial t(1/2(0-5 min))=5.4 ± 0.5 min) and in DIF (initial t(1/2(0-5 min))=5.7 ± 0.1 min), while chloramphenicol succinate and enalapril were stable in both media. The degradation of candesartan cilexetil was shown to be mediated by enzymes following Michaelis-Menten enzyme kinetics and was inhibited by addition of esterase inhibitors. The enzymatic capacity reflected by V(max) was 4-fold higher in DIF than in HIF and correlated to its 2-fold higher protein concentration. The degradation of candesartan cilexetil in the FaSSIF-pancreatin solution was slower (t(1/2)=207 ± 34 min) than the degradation in both HIF and DIF. Changing the pH to the enzyme optima or increasing the amount of pancreatin, increased the degradation rate of candesartan cilexetil, but not in the magnitude as in HIF. As a result, two in vitro models, based on in vivo intestinal fluids, were developed using candesartan cilexetil as a model drug. The DIF seems to be a reasonably good model for HIF, although the degradation capacity seems to be somewhat higher, possibly due to the higher enzyme concentration in DIF. Future investigations will develop novel enzymatic based in vitro models for rapid assessment and biopharmaceutical screening tools for prodrugs.

Innate immunity is a universal and ancient defense system in metazoans against microorganisms. Antimicrobial peptides, which are synthesized both in insects and humans, constitute an endogenous, gene-encoded defense arsenal. In Drosophila, antimicrobial peptides, such as the potent cecropins, are expressed both constitutively in barrier epithelia, as well as systemically in response to infection. Rel/NF-kappaB proteins are well-known regulators of antimicrobial peptide genes, but very few Rel/NF-kappaB co-factors and/or tissue-specific regulators have been identified. We performed a double interaction screen in yeast to isolate Drosophila cDNAs coding for direct regulators, as well as Dif co-regulators, of the CecropinA1 gene. Three classes of positive cDNA clones corresponding to 15 Drosophila genes were isolated and further characterized. One of the Dif-independent cDNAs encoded the Rel/NF-kappaB protein Relish; a well-known activator of antimicrobial peptide genes in Drosophila, demonstrating the applicability of this type of screen for isolating regulators of immune defense. Most interestingly, three transcription factors belonging to the POU domain class of homeodomain proteins, Pdm1, Pdm2 and Dfr/Vvl were isolated as Dif-interacting partners, and subsequently verified as regulators of CecA1 expression in Drosophila cells. The importance of POU proteins in development and differentiation in Drosophila and mammals is well documented, but their role in regulation of Drosophila immune defense genes is a new and essential finding.

OBJECTIVE

(1) To evaluate the measurement reliability and construct validity of the Mayo-Portland Adaptability Inventory, 4th revision (MPAI-4) in a sample consisting exclusively of patients with cerebrovascular accident (CVA) using single parameter (Rasch) item-response methods; (2) to examine the differential item functioning (DIF) by sex within the CVA population; and (3) to examine DIF and differential test functioning (DTF) across traumatic brain injury (TBI) and CVA samples.

METHODS

Retrospective psychometric analysis of rating scale data.

METHODS

Home- and community-based brain injury rehabilitation program.

METHODS

Individuals post-CVA (n=861) and individuals with TBI (n=603).

METHODS

Not applicable.

METHODS

MPAI-4.

RESULTS

Item data on admission to community-based rehabilitation were submitted to Rasch, DIF, and DTF analyses. The final calibration in the CVA sample revealed satisfactory reliability/separation for persons (.91/3.16) and items (1.00/23.64). DIF showed that items for pain, anger, audition, and memory were associated with higher levels of disability for CVA than TBI patients; whereas, self-care, mobility, and use of hands indicated greater overall disability for TBI patients. DTF analyses showed a high degree of association between the 2 sets of items (R=.92; R(2)=.85) and, at most, a 3.7 point difference in raw scores.

CONCLUSIONS

The MPAI-4 demonstrates satisfactory psychometric properties for use with individuals with CVA applying for interdisciplinary posthospital rehabilitation. DIF reveals clinically meaningful differences between CVA and TBI groups that should be considered in results at the item and subscale level.

BACKGROUND

Appropriate treatment of depression requires accurate screening and diagnosis. It is important to evaluate depression screening instruments for differential item functioning (DIF) across diverse populations. The PRIME-MD is commonly used in primary care settings to screen for the most common psychiatric disorders, including depression. The purpose of this study was to determine whether items in the mood module of the PRIME-MD perform similarly in 2 high-risk populations: impoverished black and white women.

METHODS

Data were collected during screening for a randomized controlled trial of treatment for depression in women receiving county health and welfare services. Analyses are based on a sample of 3,506 black (n = 3,191) and white (n = 315) women who completed the PRIME-MD mood module. Responses were compared using an item response theory approach to DIF assessment. Mean scores, missing data, and internal consistency reliability were also compared.

RESULTS

None of the 9 items exhibited significant DIF. Missing data rates and internal consistency reliability did not differ for the 2 groups. Mean comparisons indicated that white women endorsed higher levels of depression compared with black women on 6 of the 9 items (p < .05).

CONCLUSIONS

These results suggest that all items of the mood module of the PRIME-MD performed similarly for white and black women. Differences in endorsed depressive symptomatology on the mood module may be attributed to actual differences in DSM-IV depression symptoms between white and black women.

STAT family transcription factors regulate gene expression in response to a wide variety of cytokines. A transcription factor designated differentiation-induced factor (DIF), activated by treatment of myeloid cells with the differentiating agents interferon-gamma (IFN-gamma), granulocyte-macrophage colony-stimulating factor (GM-CSF), colony-stimulating factor-1 (CSF-1) or during phorbol ester-induced differentiation, was characterized as a 112kDa protein related to, but not identical with known isoforms of STAT 5. Taken together with previously published results, our data suggest an important function for members of the STAT 5 subfamily in regulating gene expression during the process of myeloid differentiation.

OBJECTIVE

The current study investigates the performance of alcohol use disorders in young adults using item response theory and differential item functioning (DIF).

METHODS

The 1997 National Survey of Mental Health and Wellbeing (Australia) sample was based on a stratified, multistage area probability sample of people ages 18 years and older in the Australian population. Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), alcohol use disorders were assessed in all current alcohol users (N = 7,746; 44.2% female). The psychometric properties of the DSM-IV alcohol use disorder criteria in young adults were assessed using item response theory. Age-based DIF was also assessed in each of the DSM-IV criteria for alcohol use disorders. The presence of age-based DIF in subgroups defined by sex and consumption was also examined.

RESULTS

Overall, problems were identified in the use in hazardous situations, persistent desire/inability to quit/cut down, and tolerance criteria in young adults. However, the DIF identified at the criterion level had little impact on total information provided by the criteria across the two age groups. Subgroup analyses indicated that for the female-only and non-heavy using subgroups, DIF was no longer detected in the use in hazardous situations criterion. The alcohol use disorder criteria were found to provide maximum information about moderate to severe pathology among young adults. There was little evidence for the DSM-IV abuse/dependence distinction in young adulthood.

CONCLUSIONS

Some of the DSM-IV alcohol use disorder criteria appear problematic when applied to young adults, and future research needs to focus on clarifying young adults' understanding of these problematic criteria. Although DIF was identified in three of the alcohol use disorder criteria, the total information provided by these criteria was largely the same among younger and older age groups.

BACKGROUND

It has recently been demonstrated in a study on 15 patients that plucked hair can be used as a substrate for direct immunofluorescence (DIF) in pemphigus.

OBJECTIVE

Our aim was to assess the sensitivity of DIF on plucked hairs in pemphigus vulgaris (PV) patients with positive DIF of oral mucosa.

METHODS

One hundred and ten new PV patients were enrolled in the study. They all showed the typical clinical and histological findings as well as positive DIF of the oral mucosa, diagnostic for PV. Approximately 30 hairs were obtained in the same way as for the trichogram. The hairs with their outer root sheaths (ORS) were processed for DIF in order to detect immunoglobulin G and C3.

RESULTS

Immunodeposits favouring PV were demonstrated in the ORS of 100 cases showing a sensitivity of 91%.

CONCLUSIONS

Regarding the relatively high sensitivity of DIF on plucked hair in PV patients with positive oral mucosal DIF in our study, it seems that hair plucking is a suitable alternative to the more invasive techniques of skin or mucosal biopsy for obtaining specimens for DIF in PV.

Diffusive equilibrium in thin films (DET) and diffusive gradients in thin films (DGT) were applied in situ to obtain high spatial resolution dissolved reactive phosphorus (DRP) sediment porewater profiles in two lagoons of the Gippsland Lakes (SE Australia) during summer. Although the DRP depth profiles were different in each lake, highlighting the sensitivity of DRP to the redox state of the sediment spatial DRP variations obtained from DET and DGT showed striking similarities with depth in each lake. Comparison of DRP concentrations obtained from DGT and DET allows an assessment of the reactivity of the sediment. A dynamic numerical model of DGT-induced flux in sediments (DIFS) quantified reactivity kinetics. Sediment response time (Tc) related to sedimentary phosphorus resupply resulting from DGT-induced lowering of the porewater DRP concentration was calculated. Values of Tc ranged from 4128 to 183 400 s and from 55 to 149 400 s for Lakes Victoria and Wellington, respectively. These results indicate the limited capacity of the sediment to quickly resupply DRP to the porewater, especially in surface sediment which was always characterized by the highest Tc. Adsorption and desorption rate constants were also calculated from DIFS with values ranging from 2 x 10(-3) to 2 x 10(-2) day(-1) and from 0.3 to 21 day(-1) for Lake Victoria and from 2 x 10(-4) to 0.8 day(-1) and from 0.6 to 1558 day(-1) for Lake Wellington, respectively. Diffusive fluxes estimated from the in situ DRP gradient at the sediment-water interface by DET were 558 and 1.2 micromol m(-2) day(-1) in lakes Victoria and Wellington, respectively. Despite only a single measurement, these fluxes highlight a substantial contribution of P from the sediment to the water column in summer for Lake Victoria which is likely to contribute to the recurring blooms of blue-green algae. These calculated fluxes obtained with minimal sediment disturbance and high spatial resolution were substantially different (by a factor of 6-180) from other reported values using more conventional quantitative assessments such as diffusive fluxes (from core slicing) and benthic chambers.

BACKGROUND

Direct immunofluorescence (DIF) studies in patients with lichen planus (LP) show the deposition of multiple immunoglobulins (Igs) at the cytoid bodies (CBs) and fibrin at the dermoepidermal junction (DEJ). The deposition of Ig at the DEJ, as in patients with lupus erythematosus (LE), is occasionally found. For cases with no specific clinical and histologic characteristics, or with ambiguous features, DIF studies may be helpful in disease differentiation.

METHODS

From 1996 to 2004, data from 72 patients with LP, diagnosed on the basis of clinical and histologic criteria at the Department of Dermatology, Siriraj Hospital, Bangkok, Thailand, were collected. The results of DIF studies were analyzed.

RESULTS

Deposits at the DEJ and CBs were detected in 53% and 60% of cases, respectively. A combination of DEJ (mostly fibrin) and CB (mostly IgM) deposits was found in 38% of cases. A combination of IgM and other immunoreactant deposits, including fibrin at the CBs, was found in 56% of cases.

CONCLUSIONS

This study showed that the positive yield of DIF in LP was 75%. Shaggy fibrin deposition at the DEJ, which is the single best indicator in the diagnosis of LP, was found in 56% of cases. The presence of CBs only, which is a poorer indicator than the shaggy deposition of fibrin along the DEJ, was found in 22% of cases. There were no statistically significant differences in positive DIF yield between specimens derived from glabrous skin and oral lesions (P = 0.67). Forty-four per cent of cases had immunoreactants other than fibrin deposited along the DEJ, which resembled those of LE.

Accurate assessment of attitudes about intimate partner violence is important for evaluation of prevention and early intervention programs. Assessment of attitudes about cross-gender interactions is particularly susceptible to bias because it requires specifying the gender of the perpetrator and the victim. As it is likely that respondents will tend to identify with the same-gender actor, items and scales assessing attitudes about intimate partner violence may not have equivalent measurement properties for male and female respondents. This article examines data from 2,575 high school students who participated in a teen-dating violence intervention study. The majority of participants were Latino (91%), and the sample was nearly evenly split with respect to gender (51% female). Items from two scales (boy-on-girl violence, 4 items; girl-on-boy violence, 5 items) reflecting teens' attitudes about dating violence were calibrated with the graded item response theory (IRT) model and evaluated for differential item functioning (DIF) by gender. A total of three items, two from the girl-on-boy violence scale and one from the boy-on-girl violence scale, were identified as functioning differently for girls and boys. In all cases where DIF was detected, the item's attitudinal statement was easier to accept for the gender group that was portrayed as victim rather than perpetrator. For both scales, accounting for the identified DIF influenced inferences about the magnitude of mean differences in attitudes between boys and girls. These results support the use of IRT scores that account for DIF to minimize measurement error and improve inferences about gender differences in attitudes about dating violence.

OBJECTIVE

This study aimed (i) to determine the factor structure of the 12-item General Health Questionnaire (GHQ-12) across the cancer trajectory represented by samples from three cancer care settings and (ii) to appraise the item misfit and differential item functioning (DIF) of the GHQ-12.

METHODS

Data were from cancer outpatient (n = 200), general community (n = 364) and palliative care (n = 150) settings. The factor structure was tested using exploratory factor analysis followed by confirmatory factor analysis. The factors were assessed for correlation using Spearman's ρ. The analyses were run separately for standard GHQ, Likert, modified Likert and chronic GHQ scoring and for the individual cancer settings. The best scoring method within the cancer setting was determined by Akaike's information criterion (AIC). Item misfit (mean square, MNSQ; standardised z-score, ZSTD) and DIF were assessed using the Rasch model.

RESULTS

The best scoring method was the chronic GHQ for the cancer outpatient (AIC = -45.8), modified Likert for the general community (AIC = 9.6) and standard GHQ for the palliative care (AIC = -43.0). The GHQ-12 displayed a correlated two-factor structure ('social dysfunction' and 'distress'); Spearman ρ values were 0.69, 0.82 and 0.88 in the cancer outpatient, the general community and the palliative care, respectively. One item in the palliative care indicated misfit (MNSQ = 1.62, ZSTD = 3.0). Five items in the cancer outpatient showed DIF by gender and age. Two items in the palliative care showed DIF by gender.

CONCLUSIONS

The GHQ-12 was more problematic (less clear factor structure and evidence of item bias) for newly diagnosed patients, less problematic for patients approaching end-of-life and satisfactory for patients between those times.

OBJECTIVE

To validate an item bank for assessing and detecting psychological distress in cancer patients by (1) identifying whether additional items are required in the full item bank; (2) identifying any item bias in the existing item bank; (3) linking levels of distress against thresholds derived from gold-standard psychiatric interviews (PSE/SCAN/SCID).

METHODS

A Rasch analysis was conducted on a heterogeneous sample of cancer patients (n=4919) who had completed a combination of eight psychological distress screening instruments. A subset of patients had completed a psychiatric interview along with the HADS (n=381) or PHQ-9 (n=440). Item thresholds were plotted along the latent trait. Furthermore, items were assessed for differential item functioning (DIF) by age and gender. Finally, optimum thresholds were derived for the HADS and PHQ-9 and plotted along the latent trait distribution for the entire item bank.

RESULTS

Item thresholds exceeded the range of person measures, although a gap was still present along the latent trait. No DIF was observed for either age or gender. Putative cut-offs were derived for the item bank detecting moderate to severe levels of psychological distress.

CONCLUSIONS

The item bank covers the majority of levels of emotional distress reported by cancer patients. Additionally, initial thresholds have been derived on the item bank, which correspond to a formal psychiatric assessment. Further work is required to ascertain the stability of the item bank over time and by diagnosis and stage of disease, as well as to determine additional thresholds for levels of distress.

FtsK is a multifunctional protein, which, in Escherichia coli, co-ordinates the essential functions of cell division, DNA unlinking and chromosome segregation. Its C-terminus is a DNA translocase, the fastest yet characterized, which acts as a septum-localized DNA pump. FtsK's C-terminus also interacts with the XerCD site-specific recombinases which act at the dif site, located in the terminus region. The motor domain of FtsK is an active translocase in vitro, and, when incubated with XerCD and a supercoiled plasmid containing two dif sites, recombination occurs to give unlinked circular products. Despite years of research the mechanism for this novel form of topological filter remains unknown.

Ectopic C/EBPalpha expression in p210(BCR/ABL)-expressing hematopoietic cells induces granulocytic differentiation, inhibits proliferation, and suppresses leukemogenesis. To assess the underlying mechanisms, C/EBPalpha targets were identified by microarray analyses. Upon C/EBPalpha activation, expression of c-Myb and GATA-2 was repressed in 32D-BCR/ABL, K562, and chronic myelogenous leukemia (CML) blast crisis (BC) primary cells but only c-Myb levels decreased slightly in CD34(+) normal progenitors. The role of these 2 genes for the effects of C/EBPalpha was assessed by perturbing their expression in K562 cells. Ectopic c-Myb expression blocked the proliferation inhibition- and differentiation-inducing effects of C/EBPalpha, whereas c-Myb siRNA treatment enhanced C/EBPalpha-mediated proliferation inhibition and induced changes in gene expression indicative of monocytic differentiation. Ectopic GATA-2 expression suppressed the proliferation inhibitory effect of C/EBPalpha but blocked in part the effect on differentiation; GATA-2 siRNA treatment had no effects on C/EBPalpha induction of differentiation but inhibited proliferation of K562 cells, alone or upon C/EBPalpha activation. In summary, the effects of C/EBPalpha in p210(BCR/ABL)-expressing cells depend, in part, on transcriptional repression of c-Myb and GATA-2. Since perturbation of c-Myb and GATA-2 expression has nonidentical consequences for proliferation and differentiation of K562 cells, the effects of C/EBPalpha appear to involve dif-ferent transcription-regulated targets.