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Prediction of protein-protein interaction based on structure.

A great challenge in the proteomics and structural genomics era is to predict protein structure and function from sequence, including the identification of biological partners. The development of a procedure to construct position-specific scoring matrices for the prediction and identification of sequences with putative significant affinity faces this challenge. The local and web applications used for sequence and structure search, sequence alignment, protein modeling, molecule edition and modification, and scoring matrices construction are described in detail. The methodology is based on the information contained in structural databases and takes into account the subtle conformational and sequence details that characterize different structures within a family. Using the matrices, the protein sequence databases can be easily scanned to locate putative partners of biological significance. The success of this methodology opens the way for the prediction of protein-protein interaction at genome scale.

Algorithms↗

Complete sequence of the maize chloroplast genome: gene content, hotspots of divergence and fine tuning of genetic information by transcript editing.

The nucleotide sequence of the chloroplast (cp) DNA from maize (Zea mays) has been completed. The circular double-stranded DNA, which consists of 140,387 base-pairs, contains a pair of inverted repeat regions (IRA and IRB) with 22,748 base-pairs each, which are separated by a small and a large single copy region (SSC and LSC) of 12,536 and 82,355 base-pairs, respectively. The gene content and the relative positions of a total of 104 genes (70 peptide-encoding genes, 30 tRNA genes and four rRNA genes) are identical with the chloroplast DNA of the closely related species rice (Oryza sativa). A detailed analysis of the two graminean plastomes allows the identification of hotspots of divergence which predominate in one region containing a cluster of tRNA genes and in two regions containing degenerated reading frames. One of these length differences is thought to reflect a gene transfer event from the plastome to the nucleus, which is followed by progressive degradation of the respective chloroplast gene resulting in gene fragments. The other divergent plastome region seems to be due to the complete loss of a plastid gene and its functional substitution by a nuclear encoded eukaryotic homologue. The rate of neutral nucleotide substitutions is significantly reduced for protein coding genes located in the inverted repeat regions. This indicates that the existence of inverted repeat regions confers increased genetic stability of the genes positioned in these regions as compared to genes located in the two single copy regions. Editing events cause the primary structures of several transcripts to deviate from the corresponding genomic sequences by C to U transitions. The unambiguous deduction of amino acid sequences from the nucleotide sequences of the corresponding genes is, therefore, not possible. A survey of the 25 editing positions identified in 13 different transcripts of the maize plastome shows that representatives of all protein coding gene classes are subject to editing. A strong bias exists for the second codon position and for certain codon transitions. Based on the number and the codon transition types, and taking into account the frequency of putative editing sites in all peptide encoding genes and unidentified reading frames, a total number of only few more than the experimentally verified 25 editing sites encoded in the maize plastome is estimated. This corresponds to 0.13% of amino acid positions which cannot be derived from the corresponding codons present in the corresponding genes.

Base Sequence↗

Sequence elements required for apolipoprotein B mRNA editing enhancement activity from chicken enterocytes.

Mammalian intestinal apolipoprotein B (apoB) mRNA edits codon 2153 from CAA in apoB100 mRNA to a stop codon (UAA) in apoB48 mRNA. By contrast, chicken intestinal apoB mRNA contains a CAA codon at the corresponding site, but is not edited. Chicken enterocyte S100 extracts fail to edit mammalian apoB RNA, but contain factor(s) which enhance the mammalian enterocytes editing activity. By converting the chicken apoB mooring sequences to the conserved mammalian sequences, the study confirmed that this 11-nucleotide stretch was necessary and sufficient for minimal RNA editing. Using rat and chicken apoB chimeric constructs, the study revealed that mammalian apoB sequences were required for editing enhancement. In concert with the 29-nucleotide conserved cassette, the 5' rat apoB element (nucleotides 6615-6629) increased editing at C-6666, and was necessary for editing enhancement of chicken enterocyte S100 extracts. Similarly, the 3' rat apoB element (nucleotides 6726-6752) was required for editing enhancement of chicken enterocyte S100 extracts, but to a lesser extent in efficiency, compared to the 5' region. In conclusion, this study identified the sequences required for editing enhancement activity from chicken enterocyte S100 extracts.

Animals↗

Knowledge-based segmentation of thoracic computed tomography images for assessment of split lung function.

The assessment of differential left and right lung function is important for patients under consideration for lung resection procedures such as single lung transplantation. We developed an automated, knowledge-based segmentation algorithm for purposes of deriving functional information from dynamic computed tomography (CT) image data. Median lung attenuation (HU) and area measurements were automatically calculated for each lung from thoracic CT images acquired during a forced expiratory maneuver as indicators of the amount and rate of airflow. The accuracy of these derived measures from fully automated segmentation was validated against those from segmentation using manual editing by an expert observer. A total of 1313 axial images were analyzed from 49 patients. The images were segmented using our knowledge-based system that identifies the chest wall, mediastinum, trachea, large airways and lung parenchyma on CT images. The key components of the system are an anatomical model, an inference engine and image processing routines, and segmentation involves matching objects extracted from the image to anatomical objects described in the model. The segmentation results from all images were inspected by the expert observer. Manual editing was required to correct 183 (13.94%) of the images, and the sensitivity, specificity, and accuracy of the knowledge-based segmentation were greater than 98.55% in classifying pixels as lung or nonlung. There was no significant difference between median lung attenuation or area values from automated and edited segmentations (p > 0.70). Using the knowledge-based segmentation method we can automatically derive indirect quantitative measures of single lung function that cannot be obtained using conventional pulmonary function tests.

Algorithms↗

A comparison of alternative methods of screening for dementia in clinical settings.

OBJECTIVE: To compare 3 approaches to screening for dementia: cognitive testing, informant report, and neurovisual assessment in a clinical environment. SETTING: A university hospital in Geneva, Switzerland. PATIENTS: Subjects were 76 patients admitted to the Geriatric Hospital or outpatients assessed at the Memory Clinic of the Hospitals of the University of Geneva School of Medicine in Geneva, Switzerland. Thirty-three met criteria for dementia and 11 for depression based on the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised. MAIN OUTCOME MEASURES: Performance in French-language versions of the Mini-Mental State Examination, the Informant Questionnaire on Cognitive Decline in the Elderly, and the Clinical Antisaccadic Eye Movement Test. RESULTS: All tests significantly discriminated cases of dementia from noncases. The receiver operator characteristic analysis demonstrated that the Mini-Mental State Examination and the Informant Questionnaire on Cognitive Decline in the Elderly were more efficient screening measures for dementia than the Antisaccadic Eye Movement Test in this setting. Unlike the Mini-Mental State Examination, the Informant Questionnaire on Cognitive Decline in the Elderly was unrelated to patients' educational attainment or premorbid intelligence. The previously reported strong relationship between the Mini-Mental State Examination and the Antisaccadic Eye Movement Test was not replicated in these patients. CONCLUSIONS: Both cognitive testing and informant report are efficient methods of screening for dementia in clinical settings. Factors such as sensorimotor disability or informant availability may dictate the viability of each approach in individual application. The performance of the Antisaccadic Eye Movement Test precludes recommending its use as a screen for dementia without further research into its performance.

Aged↗

Dietary intake of antioxidants and risk of Alzheimer disease.

CONTEXT: Laboratory findings have suggested that oxidative stress may contribute to the pathogenesis of Alzheimer disease. Therefore, the risk of Alzheimer disease might be reduced by intake of antioxidants that counteract the detrimental effects of oxidative stress. OBJECTIVE: To determine whether dietary intake of antioxidants is related to risk of Alzheimer disease. DESIGN AND SETTING: The Rotterdam Study, a population-based, prospective cohort study conducted in the Netherlands. PARTICIPANTS: A total of 5395 participants who, at baseline (1990-1993), were aged at least 55 years, free of dementia, and noninstitutionalized and had reliable dietary assessment. Participants were reexamined in 1993-1994 and 1997-1999 and were continuously monitored for incident dementia. MAIN OUTCOME MEASURES: Incidence of Alzheimer disease, based on Diagnostic and Statistical Manual of Mental Disorders, Revised Third Edition (DSM-III-R) criteria and National Institute of Neurological and Communicative Disorders and Stroke and Alzheimer Disease and Related Disorders Association (NINCDS-ADRDA) criteria, associated with dietary intake of beta carotene, flavonoids, vitamin C, and vitamin E. RESULTS: After a mean follow-up of 6 years, 197 participants developed dementia, of whom 146 had Alzheimer disease. When adjustments were made for age, sex, baseline Mini-Mental State Examination score, alcohol intake, education, smoking habits, pack-years of smoking, body mass index, total energy intake, presence of carotid plaques, and use of antioxidative supplements, high intake of vitamin C and vitamin E was associated with lower risk of Alzheimer disease (rate ratios [RRs] per 1-SD increase in intake were 0.82 [95% confidence interval [CI], 0.68-0.99] and 0.82 [95% CI, 0.66-1.00], respectively). Among current smokers, this relationship was most pronounced (RRs, 0.65 [95% CI, 0.37-1.14] and 0.58 [95% CI, 0.30-1.12], respectively) and also was present for intake of beta carotene (RR, 0.49 [95% CI, 0.27-0.92]) and flavonoids (RR, 0.54 [95% CI, 0.31-0.96]). The associations did not vary by education or apolipoprotein E genotype. CONCLUSION: High dietary intake of vitamin C and vitamin E may lower the risk of Alzheimer disease.

Aged↗

Patient Impairment Lexicon: a validation study.

Growth of managed behavioral health organizations (MBHOs) has increased the need for a standardized diagnostic language. The Patient Impairment Lexicon (PIL; Goodman, Brown, & Deitz, 1992, 1996) is intended to address this need. Augmenting previous psychometric assessment (Klewicki, Bjorck, Leucht, & Goodman, 1998), the current study evaluated the PIL's construct validity. Sixteen raters completed impairment inventories; diagnoses based on the Diagnostic and Statistical Manual of Mental Disorders, Third Edition, Revised (DSM-III-R; American Psychiatric Association, 1987); and independent measures of psychiatric functioning for patients in 20 vignettes. Overall rater accuracy was significantly higher for PIL impairments than for diagnoses. As predicted, there were positive correlations between PIL impairments and psychiatric functioning for all 20 vignettes, 11 of which were significant. Results remained significant after controlling variance due to: (a) raters' past experience with similar patients and (b) vignette imaginability. Findings are discussed in terms of MBHO applications and future PIL research.

Adolescent↗

Discrepancies in the study of byssinosis in China.

The existence of byssinosis in China was first reported in 1964. Detailed studies only started in the late 1970s and early 1980s. The work of the WHO study group as edited by the Technical Report Series no. 684, "Recommended health-based occupational exposure limits for selected vegetable dusts," promotes the further study of occupational disease in China; a few points need further discussion. The word byssinosis translated in Chinese is misleading as to the real pathogenesis of the disease. Some still believe cotton dust causes interstitial fibrosis, while the majority of researchers agree with the WHO study group. A poorly designed animal model may have led to the (incorrect) conclusion that dust from carding room is toxic if it is injected intratracheally. The reasons for the controversy in the prevalence of byssinosis in different reports in earlier years are the different diagnosis criteria and the fact that dust sampling methods were not standardized; pulmonary function tests were not used as a routine index; chronic bronchitis and smoking are now recognized as confounders and should have been considered. This Institute initiated the hygiene standards study on cotton dust and recommended 1 mg/m3 for respirable dust and 3 mg/m3 for total dust. If a reduction in dust levels could prevent byssinosis, it would likely also control the risk factor for developing bronchitis.

Byssinosis↗

Psychologic distress after disclosure of genetic test results regarding hereditary nonpolyposis colorectal carcinoma.

BACKGROUND: To the authors' knowledge, there have been few studies of the psychologic distress after disclosure of genetic test results for hereditary nonpolyposis colorectal carcinoma (HNPCC). The objectives of this study were to identify the prevalence rates and predictors of psychologic distress and to evaluate the feelings of guilt after disclosure of the test results in Japanese probands and unaffected relatives. METHODS: Probands and unaffected relatives were interviewed immediately after the first genetic counseling session for HNPCC and again 1 month after disclosure of the genetic test results. The prevalence of major and minor depression, acute stress disorder (ASD), posttraumatic stress disorder (PTSD), and posttraumatic stress symptoms (PTSS) were assessed using the Structured Clinical Interview based on the Diagnostic and Statistical Manual of Mental Disorders, 3rd edition revised (DSM-III-R) or the DSM-IV; feelings of guilt were investigated using a numeric scale and a semistructured interview. RESULTS: Among 47 participants who completed the baseline interview, 42 participants (89%) completed the 1-month follow-up interview. Although none of the participants met the criteria for major depression, ASD, or PTSD at the follow-up interview, 3 of 42 participants (7%) met the criteria for minor depression and 2 participants (5%) had PTSS. The only predictor of psychologic distress found was the presence of a history of major or minor depression (odds ratio, 19.41; 95% confidence interval, 1.42-264.95; P < 0.05). Five of 42 participants (12%) had feelings of guilt. CONCLUSIONS: Disclosure of genetic test results for HNPCC may not cause significant psychologic distress in Japanese probands or relatives. However, healthcare providers should not neglect to assess these individuals for psychologic responses, such as minor depression and PTSS.

Adult↗

The risk of birth defects in multiple births: a population-based study.

OBJECTIVES: To determine if multiple births have higher risks of birth defects compared to singletons and to identify types of birth defects that occur more frequently in multiple births, controlling for seven sociodemographic and health-related variables. METHODS: A retrospective cohort study was conducted of all resident live births in Florida during 1996-2000 using data from a population-based surveillance system. Birth defects were defined as in the 9th edition of the International Classification of Diseases-Clinical Modification (ICD-9-CM) code for the 42 reportable categories in the Centers for Disease Control and Prevention (CDC) Birth Defects Registry list and eight major birth defects classifications. Relative risks (RR) before and after adjusting for control variables and 95% confidence intervals (95% CI) were calculated. The control variables included mother's race, age, previous adverse pregnancy experience, education, Medicaid participation during pregnancy, infant's sex and number of siblings. RESULTS: This study included 972,694 live births (27,727 multiple births and 944,967 singletons). Birth defects prevalence per 10,000 live births was 358.50 for multiple births and 250.54 for singletons. After adjusting for control variables, multiple births had a 46% increased risk of birth defects compared to singletons. Higher risks were found in 23 of 40 birth defects for multiple births. Five highest adjusted relative risks for birth defects among multiple births were: anencephalus, biliary atresia, hydrocephalus without spina bifida, pulmonary valve atresia and stenosis, and bladder exstrophy. Increased risks were also found in 6 out of 8 major birth defects classifications. CONCLUSIONS: Multiple births have increased risks of birth defects compared to singletons.

Adult↗

Socio-demographic correlates and pattern of drug abuse in eastern Saudi Arabia.

This is a preliminary study of the socio-demographic characteristics and pattern of substance abuse in the eastern region of Saudi Arabia. Clinico-statistical analysis of 116 patients was based on the Diagnostic and Statistical Manual for Mental Disorder, Third Edition, Revised (DSM-III-R) definitions of drug abuse, a semi-structured psychiatric interview and examination, and laboratory investigations. Eighty-three percent of the patients were below the age of 32 years, 52.6% were unemployed and the majority were of intermediate education. Eighty-four percent of the patients abused heroin either alone or in combination with other drugs. Of the patients 31% used alcohol, 26% used cannabis, and 10% used stimulants. The use of other drugs was rare. Heroin abusers were younger with short duration and less polydrug abuse than alcoholics. In comparison with heroin abusers studied abroad, more of our patients were employed and drug use was more chronic, i.e., the mean duration of drug abuse was much longer.

Adult↗

Tumor, node, metastasis classification of malignant ciliary body and choroidal melanoma evaluation of the 6th edition and future directions.

PURPOSE: The tumor, node, metastasis classification of malignant uveal melanoma has been revised. We evaluated how the 6th edition (TNM6) improves on the previous one (TNM5). DESIGN: Population-based, retrospective, cross-sectional study. PARTICIPANTS: Two hundred eighty-nine consecutive patients who had a ciliary body and choroidal melanoma treated in the district of the Helsinki University Central Hospital, Finland, between 1962 and 1981. METHODS: Tumor dimensions, ciliary body involvement, and extraocular extension were evaluated from histopathologic sections and pathology reports. Tumors were assigned into categories and stages according to TNM6, TNM5, and 2 previously proposed size classifications. MAIN OUTCOME MEASURES: Proportion of tumors classified in each category and melanoma-specific survival by category and stage. RESULTS: Of the 289 melanomas, 5% were classified as pT1, 63% as pT2, 22% as pT3, and 7% as pT4 according to TNM6. The corresponding percentages based on TNM5 were 8%, 17%, 63%, and 10%. Of pT2 tumors in TNM6, 4% came from pT1, 65% from pT3, and 4% from pT4 category of TNM5. Of 28 melanomas with extraocular growth, 29% were classified as pT2 in TNM6 rather than pT4 in TNM5. The 10-year survival estimate was 2 percentage points lower for pT1, 7 percentage points higher for pT2, 17 percentage points lower for pT3, and 13 percentage points lower for pT4 by TNM6 compared with TNM5; TNM6 (P<0.0001) and the modified alternative size classifications (P = 0.0022 and P = 0.0026) divided tumors according to prognosis better than TNM5. The 10-year survival for stage I, II, and III tumors was 2 percentage points lower, 7 points higher, and 23 points lower by TNM6, which was not better than TNM5 in separating patients according to prognosis (P = 0.47). The alternative size classifications provided more equal categories and fitted the data set better than TNM5 regarding prognosis. CONCLUSIONS: TNM6 is an improvement over TNM5 in some, but not all, respects. Areas for development include taking into account ciliary body involvement and extraocular extension in more detail and combining into each stage tumor categories with similar rather than different prognosis. An evidence-based, multicenter approach would be beneficial.

Cause of Death↗

Efficacy of naftidrofuryl in patients with vascular or mixed dementia: results of a multicenter, double-blind trial.

BACKGROUND: Dementia is a cerebral disorder resulting in a progressive deterioration of intellectual function that compromises the patient's ability to function. The diagnostic criteria for dementia are primarily clinical and are based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition. The Hachinski score and computed tomography of the brain help distinguish between degenerative and vascular dementias. OBJECTIVE: This study examined the efficacy of naftidrofuryl in patients with vascular or mixed dementia. METHODS: This multicenter, randomized, double-blind study compared naftidrofuryl 600 mg/d with placebo for 1 year in patients with vascular or mixed dementia. A preliminary 2-month washout period allowed selection of patients who were compliant with treatment. The end point was change in the scores on the Alzheimer Disease Assessment Scale cognitive subscale and the Mini-Mental State Examination. RESULTS: Eighty-four patients were assessable on an intent-to-treat basis, and 74 were assessable for the per-protocol analysis (on-treatment). Statistically significant improvements in cognitive and global function were observed in patients receiving naftidrofuryl. Naftidrofuryl was well tolerated, and produced no clinically significant abnormalities in laboratory test results. CONCLUSION: The results of this study suggest that naftidrofuryl is effective and well tolerated in treating the symptoms of vascular and mixed dementia.

Aged↗

Computer-generated time lines for visualizing and editing epidemiological and biomedical data.

Most biomedical data have a temporal dimension. Time-line displays spatialize this dimension and help the viewer comprehend large sets of complex data. If we add ways for users to selectively expand the details of data visible on a time line, even more information can be organized and accessed. Design issues for this kind of display include: how to display time scales that are often wider than the physical display space; how to display events with brief duration; how to display data for two or more events that overlap in time; how to manage the display of data details; how to allow database editing from a time line; and how to facilitate time-based analytical techniques. We describe a time-line display system that addresses each of these issues, and show how it can be used to organize data for an epidemiological study of parental radiation exposure and childhood leukemia. We also suggest further refinements of the time line technique for other biomedical applications.

Child↗

Trends in antihypertensive drugs in the elderly: the decline of thiazides.

The last decade has seen the publication of different editions of guidelines for the pharmacological treatment of hypertension that were based on the results of large, randomised trials. Since these guidelines were meant to inform practitioners, we analysed the pattern of prescription of antihypertensive agents between 1988 and 1997 among older hospitalised adults. Because of the wealth of data supporting the use of thiazides diuretics, we focused on diuretic prescription, to identify independent predictors of their utilisation. To this end, we used the GIFA database that includes patients admitted to academic medical centres throughout Italy between 1988 and 1997. We studied 5061 patients over 65 years of age selected among a population of 28 411, based on the diagnosis of arterial hypertension at discharge. The use of ACE-inhibitors has been raising steadily through the years, and they are the agents most commonly used since 1996. Calcium channel blockers showed a similar trend and were the top prescribing drug until 1995; afterwards, the documentation of potentially severe side effects has resulted in a nearly 20% reduction of their use. Beta-blockers have remained unpopular throughout the decade. Instead, the prescription of diuretics as a class showed a biphasic trend; an initial decrease with a prolonged steady state and a more recent raise. However, at a separate analysis, it was a evident that a progressive increase of the use of loop diuretics since 1988 has been paralleled by a nearly 50% reduction of thiazides prescriptions. Loop diuretics were more likely to be prescribed to older individuals, those with cardiac heart failure, coronary heart disease and high creatinine level. In contrast, independent predictors of thiazides use were female gender, good functional status, preserved renal function, and absence of cardiovascular comorbidity. In conclusion, despite continued recommendations to use thiazides diuretics for the treatment of hypertension among older individuals, their use has been declining steadily between 1988 and 1997. A possible explanation is that the choice to prescribe a thiazides diuretic is influenced by age, functional status and comorbidity.

Age Factors↗

Changes in mu opioid receptors and rheological properties of erythrocytes among opioid abusers.

Opioids, reported originally to bind to specific receptors in the brain, now also appear to bind to receptors on blood cells. The high prevalence of anemia among chronic opioid users leads us to propose that chronic opiate use results in elevated mu opioid receptor levels on human erythrocytes and that these receptor changes may affect erythrocyte membrane properties. Blood samples from 17 opioid-dependent subjects (based on the Diagnostic and Statistical Manual of Mental Disorders, 4th edition or DSM-IV) and 15 drug-free controls were assayed for mu opioid receptors on erythrocytes using a flow cytometry immunoassay. Deformability and the hydration status of erythrocytes were studied by ektacytometry. Data were analyzed by independent t-tests, tests of correlation, chi square and cluster analyses. As expected, the percentage of erythrocytes from opioid-dependent subjects with opioid receptors (opioid receptor levels) was significantly higher (47.4 +/- 38.3%) than controls (22.8 +/- 30.1%) (t = 2.01, df = 30, p < 0.05). Also, the opioid-dependent patients showed a wide variation in the percentage of erythrocytes bearing opioid receptors and data analyses of these patients showed two strongly defined clusters. One subgroup consisted of nine individuals with very high receptor levels (mean = 81.5%) while the other had eight patients with low receptor levels (mean = 9.1%) that were not significantly different than the receptor levels of controls. Ektacytometry of opioid dependent patients with high opioid receptor levels showed changes in rheological parameters of erythrocytes, such as deformability index and cellular hydration. For example, a positive correlation was observed between opioid receptor levels and deformability indices among opioid-dependent patients (r = 0.74, p < 0.005). Our findings indicate that the mu opioid receptor is present on human erythrocytes, although with considerable variation in receptor levels, and that the levels of this receptor are significantly elevated with chronic opioid exposure. Moreover, erythrocytes with high opioid receptor levels from chronic opiate users seem to have high deformability. This study may offer clues to the biological properties of peripheral blood cells that may be mediated by mu opioid receptors and lead to a better understanding of some of the clinical effects of opioid use.

Adult↗

Making a structured psychiatric diagnostic interview faithful to the nomenclature.

Psychiatric diagnostic interviews to be used in epidemiologic studies by lay interviewers have, since the 1970s, attempted to operationalize existing psychiatric nomenclatures. How to maximize the chances that they do so successfully has not previously been spelled out. In this article, the authors discuss strategies for each of the seven steps involved in writing, updating, or modifying a diagnostic interview and its supporting materials: 1) writing questions that match the nomenclature's criteria, 2) checking that respondents will be willing and able to answer the questions, 3) choosing a format acceptable to interviewers that maximizes accurate answering and recording of answers, 4) constructing a data entry and cleaning program that highlights errors to be corrected, 5) creating a diagnostic scoring program that matches the nomenclature's algorithms, 6) developing an interviewer training program that maximizes reliability, and 7) computerizing the interview. For each step, the authors discuss how to identify errors, correct them, and validate the revisions. Although operationalization will never be perfect because of ambiguities in the nomenclature, specifying methods for minimizing divergence from the nomenclature is timely as users modify existing interviews and look forward to updating interviews based on the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, and the International Classification of Diseases, Eleventh Revision.

Algorithms↗

On the measurement of nicotine dependence in adolescence: comparisons of the mFTQ and a DSM-IV-based scale.

OBJECTIVE: To compare nicotine-dependent smokers identified by the modified Fagerström Tolerance Questionnaire (mFTQ) and a scale based on the Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV), in a multiethnic adolescent sample. METHODS: A school survey was conducted on 6th- to 10th-grade students (N=15,007) in a large urban public school system. RESULTS: The two scales formed two distinct factors. The concordance between the two classifications of nicotine dependence was low. The DSM identified a much larger number of nicotine-dependent smokers than the mFTQ, mostly because smokers met dependence criteria at much lower levels of cigarettes consumed, especially when they were depressed. Rates of dependence were higher among whites than minority-group members, especially African Americans. Control for level of cigarette consumption attenuated or eliminated ethnic differences. CONCLUSIONS: This investigation provides some understanding of youths defined as dependent by each scale but cannot by itself indicate which scale better measures dependence. Differences in dependence rates among ethnic groups are accounted for mostly by quantity of cigarettes smoked.

Adolescent↗